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1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements semantic analysis for C++ declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Sema/SemaInternal.h"
15 #include "clang/Sema/CXXFieldCollector.h"
16 #include "clang/Sema/Scope.h"
17 #include "clang/Sema/Initialization.h"
18 #include "clang/Sema/Lookup.h"
19 #include "clang/Sema/ScopeInfo.h"
20 #include "clang/AST/ASTConsumer.h"
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/ASTMutationListener.h"
23 #include "clang/AST/CharUnits.h"
24 #include "clang/AST/CXXInheritance.h"
25 #include "clang/AST/DeclVisitor.h"
26 #include "clang/AST/ExprCXX.h"
27 #include "clang/AST/RecordLayout.h"
28 #include "clang/AST/RecursiveASTVisitor.h"
29 #include "clang/AST/StmtVisitor.h"
30 #include "clang/AST/TypeLoc.h"
31 #include "clang/AST/TypeOrdering.h"
32 #include "clang/Sema/DeclSpec.h"
33 #include "clang/Sema/ParsedTemplate.h"
34 #include "clang/Basic/PartialDiagnostic.h"
35 #include "clang/Lex/Preprocessor.h"
36 #include "llvm/ADT/SmallString.h"
37 #include "llvm/ADT/STLExtras.h"
38 #include <map>
39 #include <set>
40 
41 using namespace clang;
42 
43 //===----------------------------------------------------------------------===//
44 // CheckDefaultArgumentVisitor
45 //===----------------------------------------------------------------------===//
46 
47 namespace {
48   /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
49   /// the default argument of a parameter to determine whether it
50   /// contains any ill-formed subexpressions. For example, this will
51   /// diagnose the use of local variables or parameters within the
52   /// default argument expression.
53   class CheckDefaultArgumentVisitor
54     : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
55     Expr *DefaultArg;
56     Sema *S;
57 
58   public:
CheckDefaultArgumentVisitor(Expr * defarg,Sema * s)59     CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
60       : DefaultArg(defarg), S(s) {}
61 
62     bool VisitExpr(Expr *Node);
63     bool VisitDeclRefExpr(DeclRefExpr *DRE);
64     bool VisitCXXThisExpr(CXXThisExpr *ThisE);
65     bool VisitLambdaExpr(LambdaExpr *Lambda);
66   };
67 
68   /// VisitExpr - Visit all of the children of this expression.
VisitExpr(Expr * Node)69   bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
70     bool IsInvalid = false;
71     for (Stmt::child_range I = Node->children(); I; ++I)
72       IsInvalid |= Visit(*I);
73     return IsInvalid;
74   }
75 
76   /// VisitDeclRefExpr - Visit a reference to a declaration, to
77   /// determine whether this declaration can be used in the default
78   /// argument expression.
VisitDeclRefExpr(DeclRefExpr * DRE)79   bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
80     NamedDecl *Decl = DRE->getDecl();
81     if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
82       // C++ [dcl.fct.default]p9
83       //   Default arguments are evaluated each time the function is
84       //   called. The order of evaluation of function arguments is
85       //   unspecified. Consequently, parameters of a function shall not
86       //   be used in default argument expressions, even if they are not
87       //   evaluated. Parameters of a function declared before a default
88       //   argument expression are in scope and can hide namespace and
89       //   class member names.
90       return S->Diag(DRE->getLocStart(),
91                      diag::err_param_default_argument_references_param)
92          << Param->getDeclName() << DefaultArg->getSourceRange();
93     } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
94       // C++ [dcl.fct.default]p7
95       //   Local variables shall not be used in default argument
96       //   expressions.
97       if (VDecl->isLocalVarDecl())
98         return S->Diag(DRE->getLocStart(),
99                        diag::err_param_default_argument_references_local)
100           << VDecl->getDeclName() << DefaultArg->getSourceRange();
101     }
102 
103     return false;
104   }
105 
106   /// VisitCXXThisExpr - Visit a C++ "this" expression.
VisitCXXThisExpr(CXXThisExpr * ThisE)107   bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
108     // C++ [dcl.fct.default]p8:
109     //   The keyword this shall not be used in a default argument of a
110     //   member function.
111     return S->Diag(ThisE->getLocStart(),
112                    diag::err_param_default_argument_references_this)
113                << ThisE->getSourceRange();
114   }
115 
VisitLambdaExpr(LambdaExpr * Lambda)116   bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
117     // C++11 [expr.lambda.prim]p13:
118     //   A lambda-expression appearing in a default argument shall not
119     //   implicitly or explicitly capture any entity.
120     if (Lambda->capture_begin() == Lambda->capture_end())
121       return false;
122 
123     return S->Diag(Lambda->getLocStart(),
124                    diag::err_lambda_capture_default_arg);
125   }
126 }
127 
CalledDecl(SourceLocation CallLoc,CXXMethodDecl * Method)128 void Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
129                                                       CXXMethodDecl *Method) {
130   // If we have an MSAny or unknown spec already, don't bother.
131   if (!Method || ComputedEST == EST_MSAny || ComputedEST == EST_Delayed)
132     return;
133 
134   const FunctionProtoType *Proto
135     = Method->getType()->getAs<FunctionProtoType>();
136   Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
137   if (!Proto)
138     return;
139 
140   ExceptionSpecificationType EST = Proto->getExceptionSpecType();
141 
142   // If this function can throw any exceptions, make a note of that.
143   if (EST == EST_Delayed || EST == EST_MSAny || EST == EST_None) {
144     ClearExceptions();
145     ComputedEST = EST;
146     return;
147   }
148 
149   // FIXME: If the call to this decl is using any of its default arguments, we
150   // need to search them for potentially-throwing calls.
151 
152   // If this function has a basic noexcept, it doesn't affect the outcome.
153   if (EST == EST_BasicNoexcept)
154     return;
155 
156   // If we have a throw-all spec at this point, ignore the function.
157   if (ComputedEST == EST_None)
158     return;
159 
160   // If we're still at noexcept(true) and there's a nothrow() callee,
161   // change to that specification.
162   if (EST == EST_DynamicNone) {
163     if (ComputedEST == EST_BasicNoexcept)
164       ComputedEST = EST_DynamicNone;
165     return;
166   }
167 
168   // Check out noexcept specs.
169   if (EST == EST_ComputedNoexcept) {
170     FunctionProtoType::NoexceptResult NR =
171         Proto->getNoexceptSpec(Self->Context);
172     assert(NR != FunctionProtoType::NR_NoNoexcept &&
173            "Must have noexcept result for EST_ComputedNoexcept.");
174     assert(NR != FunctionProtoType::NR_Dependent &&
175            "Should not generate implicit declarations for dependent cases, "
176            "and don't know how to handle them anyway.");
177 
178     // noexcept(false) -> no spec on the new function
179     if (NR == FunctionProtoType::NR_Throw) {
180       ClearExceptions();
181       ComputedEST = EST_None;
182     }
183     // noexcept(true) won't change anything either.
184     return;
185   }
186 
187   assert(EST == EST_Dynamic && "EST case not considered earlier.");
188   assert(ComputedEST != EST_None &&
189          "Shouldn't collect exceptions when throw-all is guaranteed.");
190   ComputedEST = EST_Dynamic;
191   // Record the exceptions in this function's exception specification.
192   for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
193                                           EEnd = Proto->exception_end();
194        E != EEnd; ++E)
195     if (ExceptionsSeen.insert(Self->Context.getCanonicalType(*E)))
196       Exceptions.push_back(*E);
197 }
198 
CalledExpr(Expr * E)199 void Sema::ImplicitExceptionSpecification::CalledExpr(Expr *E) {
200   if (!E || ComputedEST == EST_MSAny || ComputedEST == EST_Delayed)
201     return;
202 
203   // FIXME:
204   //
205   // C++0x [except.spec]p14:
206   //   [An] implicit exception-specification specifies the type-id T if and
207   // only if T is allowed by the exception-specification of a function directly
208   // invoked by f's implicit definition; f shall allow all exceptions if any
209   // function it directly invokes allows all exceptions, and f shall allow no
210   // exceptions if every function it directly invokes allows no exceptions.
211   //
212   // Note in particular that if an implicit exception-specification is generated
213   // for a function containing a throw-expression, that specification can still
214   // be noexcept(true).
215   //
216   // Note also that 'directly invoked' is not defined in the standard, and there
217   // is no indication that we should only consider potentially-evaluated calls.
218   //
219   // Ultimately we should implement the intent of the standard: the exception
220   // specification should be the set of exceptions which can be thrown by the
221   // implicit definition. For now, we assume that any non-nothrow expression can
222   // throw any exception.
223 
224   if (Self->canThrow(E))
225     ComputedEST = EST_None;
226 }
227 
228 bool
SetParamDefaultArgument(ParmVarDecl * Param,Expr * Arg,SourceLocation EqualLoc)229 Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
230                               SourceLocation EqualLoc) {
231   if (RequireCompleteType(Param->getLocation(), Param->getType(),
232                           diag::err_typecheck_decl_incomplete_type)) {
233     Param->setInvalidDecl();
234     return true;
235   }
236 
237   // C++ [dcl.fct.default]p5
238   //   A default argument expression is implicitly converted (clause
239   //   4) to the parameter type. The default argument expression has
240   //   the same semantic constraints as the initializer expression in
241   //   a declaration of a variable of the parameter type, using the
242   //   copy-initialization semantics (8.5).
243   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
244                                                                     Param);
245   InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
246                                                            EqualLoc);
247   InitializationSequence InitSeq(*this, Entity, Kind, &Arg, 1);
248   ExprResult Result = InitSeq.Perform(*this, Entity, Kind,
249                                       MultiExprArg(*this, &Arg, 1));
250   if (Result.isInvalid())
251     return true;
252   Arg = Result.takeAs<Expr>();
253 
254   CheckImplicitConversions(Arg, EqualLoc);
255   Arg = MaybeCreateExprWithCleanups(Arg);
256 
257   // Okay: add the default argument to the parameter
258   Param->setDefaultArg(Arg);
259 
260   // We have already instantiated this parameter; provide each of the
261   // instantiations with the uninstantiated default argument.
262   UnparsedDefaultArgInstantiationsMap::iterator InstPos
263     = UnparsedDefaultArgInstantiations.find(Param);
264   if (InstPos != UnparsedDefaultArgInstantiations.end()) {
265     for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
266       InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
267 
268     // We're done tracking this parameter's instantiations.
269     UnparsedDefaultArgInstantiations.erase(InstPos);
270   }
271 
272   return false;
273 }
274 
275 /// ActOnParamDefaultArgument - Check whether the default argument
276 /// provided for a function parameter is well-formed. If so, attach it
277 /// to the parameter declaration.
278 void
ActOnParamDefaultArgument(Decl * param,SourceLocation EqualLoc,Expr * DefaultArg)279 Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
280                                 Expr *DefaultArg) {
281   if (!param || !DefaultArg)
282     return;
283 
284   ParmVarDecl *Param = cast<ParmVarDecl>(param);
285   UnparsedDefaultArgLocs.erase(Param);
286 
287   // Default arguments are only permitted in C++
288   if (!getLangOpts().CPlusPlus) {
289     Diag(EqualLoc, diag::err_param_default_argument)
290       << DefaultArg->getSourceRange();
291     Param->setInvalidDecl();
292     return;
293   }
294 
295   // Check for unexpanded parameter packs.
296   if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
297     Param->setInvalidDecl();
298     return;
299   }
300 
301   // Check that the default argument is well-formed
302   CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
303   if (DefaultArgChecker.Visit(DefaultArg)) {
304     Param->setInvalidDecl();
305     return;
306   }
307 
308   SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
309 }
310 
311 /// ActOnParamUnparsedDefaultArgument - We've seen a default
312 /// argument for a function parameter, but we can't parse it yet
313 /// because we're inside a class definition. Note that this default
314 /// argument will be parsed later.
ActOnParamUnparsedDefaultArgument(Decl * param,SourceLocation EqualLoc,SourceLocation ArgLoc)315 void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
316                                              SourceLocation EqualLoc,
317                                              SourceLocation ArgLoc) {
318   if (!param)
319     return;
320 
321   ParmVarDecl *Param = cast<ParmVarDecl>(param);
322   if (Param)
323     Param->setUnparsedDefaultArg();
324 
325   UnparsedDefaultArgLocs[Param] = ArgLoc;
326 }
327 
328 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
329 /// the default argument for the parameter param failed.
ActOnParamDefaultArgumentError(Decl * param)330 void Sema::ActOnParamDefaultArgumentError(Decl *param) {
331   if (!param)
332     return;
333 
334   ParmVarDecl *Param = cast<ParmVarDecl>(param);
335 
336   Param->setInvalidDecl();
337 
338   UnparsedDefaultArgLocs.erase(Param);
339 }
340 
341 /// CheckExtraCXXDefaultArguments - Check for any extra default
342 /// arguments in the declarator, which is not a function declaration
343 /// or definition and therefore is not permitted to have default
344 /// arguments. This routine should be invoked for every declarator
345 /// that is not a function declaration or definition.
CheckExtraCXXDefaultArguments(Declarator & D)346 void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
347   // C++ [dcl.fct.default]p3
348   //   A default argument expression shall be specified only in the
349   //   parameter-declaration-clause of a function declaration or in a
350   //   template-parameter (14.1). It shall not be specified for a
351   //   parameter pack. If it is specified in a
352   //   parameter-declaration-clause, it shall not occur within a
353   //   declarator or abstract-declarator of a parameter-declaration.
354   for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
355     DeclaratorChunk &chunk = D.getTypeObject(i);
356     if (chunk.Kind == DeclaratorChunk::Function) {
357       for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
358         ParmVarDecl *Param =
359           cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param);
360         if (Param->hasUnparsedDefaultArg()) {
361           CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
362           Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
363             << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
364           delete Toks;
365           chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
366         } else if (Param->getDefaultArg()) {
367           Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
368             << Param->getDefaultArg()->getSourceRange();
369           Param->setDefaultArg(0);
370         }
371       }
372     }
373   }
374 }
375 
376 // MergeCXXFunctionDecl - Merge two declarations of the same C++
377 // function, once we already know that they have the same
378 // type. Subroutine of MergeFunctionDecl. Returns true if there was an
379 // error, false otherwise.
MergeCXXFunctionDecl(FunctionDecl * New,FunctionDecl * Old,Scope * S)380 bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
381                                 Scope *S) {
382   bool Invalid = false;
383 
384   // C++ [dcl.fct.default]p4:
385   //   For non-template functions, default arguments can be added in
386   //   later declarations of a function in the same
387   //   scope. Declarations in different scopes have completely
388   //   distinct sets of default arguments. That is, declarations in
389   //   inner scopes do not acquire default arguments from
390   //   declarations in outer scopes, and vice versa. In a given
391   //   function declaration, all parameters subsequent to a
392   //   parameter with a default argument shall have default
393   //   arguments supplied in this or previous declarations. A
394   //   default argument shall not be redefined by a later
395   //   declaration (not even to the same value).
396   //
397   // C++ [dcl.fct.default]p6:
398   //   Except for member functions of class templates, the default arguments
399   //   in a member function definition that appears outside of the class
400   //   definition are added to the set of default arguments provided by the
401   //   member function declaration in the class definition.
402   for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
403     ParmVarDecl *OldParam = Old->getParamDecl(p);
404     ParmVarDecl *NewParam = New->getParamDecl(p);
405 
406     bool OldParamHasDfl = OldParam->hasDefaultArg();
407     bool NewParamHasDfl = NewParam->hasDefaultArg();
408 
409     NamedDecl *ND = Old;
410     if (S && !isDeclInScope(ND, New->getDeclContext(), S))
411       // Ignore default parameters of old decl if they are not in
412       // the same scope.
413       OldParamHasDfl = false;
414 
415     if (OldParamHasDfl && NewParamHasDfl) {
416 
417       unsigned DiagDefaultParamID =
418         diag::err_param_default_argument_redefinition;
419 
420       // MSVC accepts that default parameters be redefined for member functions
421       // of template class. The new default parameter's value is ignored.
422       Invalid = true;
423       if (getLangOpts().MicrosoftExt) {
424         CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(New);
425         if (MD && MD->getParent()->getDescribedClassTemplate()) {
426           // Merge the old default argument into the new parameter.
427           NewParam->setHasInheritedDefaultArg();
428           if (OldParam->hasUninstantiatedDefaultArg())
429             NewParam->setUninstantiatedDefaultArg(
430                                       OldParam->getUninstantiatedDefaultArg());
431           else
432             NewParam->setDefaultArg(OldParam->getInit());
433           DiagDefaultParamID = diag::warn_param_default_argument_redefinition;
434           Invalid = false;
435         }
436       }
437 
438       // FIXME: If we knew where the '=' was, we could easily provide a fix-it
439       // hint here. Alternatively, we could walk the type-source information
440       // for NewParam to find the last source location in the type... but it
441       // isn't worth the effort right now. This is the kind of test case that
442       // is hard to get right:
443       //   int f(int);
444       //   void g(int (*fp)(int) = f);
445       //   void g(int (*fp)(int) = &f);
446       Diag(NewParam->getLocation(), DiagDefaultParamID)
447         << NewParam->getDefaultArgRange();
448 
449       // Look for the function declaration where the default argument was
450       // actually written, which may be a declaration prior to Old.
451       for (FunctionDecl *Older = Old->getPreviousDecl();
452            Older; Older = Older->getPreviousDecl()) {
453         if (!Older->getParamDecl(p)->hasDefaultArg())
454           break;
455 
456         OldParam = Older->getParamDecl(p);
457       }
458 
459       Diag(OldParam->getLocation(), diag::note_previous_definition)
460         << OldParam->getDefaultArgRange();
461     } else if (OldParamHasDfl) {
462       // Merge the old default argument into the new parameter.
463       // It's important to use getInit() here;  getDefaultArg()
464       // strips off any top-level ExprWithCleanups.
465       NewParam->setHasInheritedDefaultArg();
466       if (OldParam->hasUninstantiatedDefaultArg())
467         NewParam->setUninstantiatedDefaultArg(
468                                       OldParam->getUninstantiatedDefaultArg());
469       else
470         NewParam->setDefaultArg(OldParam->getInit());
471     } else if (NewParamHasDfl) {
472       if (New->getDescribedFunctionTemplate()) {
473         // Paragraph 4, quoted above, only applies to non-template functions.
474         Diag(NewParam->getLocation(),
475              diag::err_param_default_argument_template_redecl)
476           << NewParam->getDefaultArgRange();
477         Diag(Old->getLocation(), diag::note_template_prev_declaration)
478           << false;
479       } else if (New->getTemplateSpecializationKind()
480                    != TSK_ImplicitInstantiation &&
481                  New->getTemplateSpecializationKind() != TSK_Undeclared) {
482         // C++ [temp.expr.spec]p21:
483         //   Default function arguments shall not be specified in a declaration
484         //   or a definition for one of the following explicit specializations:
485         //     - the explicit specialization of a function template;
486         //     - the explicit specialization of a member function template;
487         //     - the explicit specialization of a member function of a class
488         //       template where the class template specialization to which the
489         //       member function specialization belongs is implicitly
490         //       instantiated.
491         Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
492           << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
493           << New->getDeclName()
494           << NewParam->getDefaultArgRange();
495       } else if (New->getDeclContext()->isDependentContext()) {
496         // C++ [dcl.fct.default]p6 (DR217):
497         //   Default arguments for a member function of a class template shall
498         //   be specified on the initial declaration of the member function
499         //   within the class template.
500         //
501         // Reading the tea leaves a bit in DR217 and its reference to DR205
502         // leads me to the conclusion that one cannot add default function
503         // arguments for an out-of-line definition of a member function of a
504         // dependent type.
505         int WhichKind = 2;
506         if (CXXRecordDecl *Record
507               = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
508           if (Record->getDescribedClassTemplate())
509             WhichKind = 0;
510           else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
511             WhichKind = 1;
512           else
513             WhichKind = 2;
514         }
515 
516         Diag(NewParam->getLocation(),
517              diag::err_param_default_argument_member_template_redecl)
518           << WhichKind
519           << NewParam->getDefaultArgRange();
520       } else if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(New)) {
521         CXXSpecialMember NewSM = getSpecialMember(Ctor),
522                          OldSM = getSpecialMember(cast<CXXConstructorDecl>(Old));
523         if (NewSM != OldSM) {
524           Diag(NewParam->getLocation(),diag::warn_default_arg_makes_ctor_special)
525             << NewParam->getDefaultArgRange() << NewSM;
526           Diag(Old->getLocation(), diag::note_previous_declaration_special)
527             << OldSM;
528         }
529       }
530     }
531   }
532 
533   // C++11 [dcl.constexpr]p1: If any declaration of a function or function
534   // template has a constexpr specifier then all its declarations shall
535   // contain the constexpr specifier.
536   if (New->isConstexpr() != Old->isConstexpr()) {
537     Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
538       << New << New->isConstexpr();
539     Diag(Old->getLocation(), diag::note_previous_declaration);
540     Invalid = true;
541   }
542 
543   if (CheckEquivalentExceptionSpec(Old, New))
544     Invalid = true;
545 
546   return Invalid;
547 }
548 
549 /// \brief Merge the exception specifications of two variable declarations.
550 ///
551 /// This is called when there's a redeclaration of a VarDecl. The function
552 /// checks if the redeclaration might have an exception specification and
553 /// validates compatibility and merges the specs if necessary.
MergeVarDeclExceptionSpecs(VarDecl * New,VarDecl * Old)554 void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
555   // Shortcut if exceptions are disabled.
556   if (!getLangOpts().CXXExceptions)
557     return;
558 
559   assert(Context.hasSameType(New->getType(), Old->getType()) &&
560          "Should only be called if types are otherwise the same.");
561 
562   QualType NewType = New->getType();
563   QualType OldType = Old->getType();
564 
565   // We're only interested in pointers and references to functions, as well
566   // as pointers to member functions.
567   if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
568     NewType = R->getPointeeType();
569     OldType = OldType->getAs<ReferenceType>()->getPointeeType();
570   } else if (const PointerType *P = NewType->getAs<PointerType>()) {
571     NewType = P->getPointeeType();
572     OldType = OldType->getAs<PointerType>()->getPointeeType();
573   } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
574     NewType = M->getPointeeType();
575     OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
576   }
577 
578   if (!NewType->isFunctionProtoType())
579     return;
580 
581   // There's lots of special cases for functions. For function pointers, system
582   // libraries are hopefully not as broken so that we don't need these
583   // workarounds.
584   if (CheckEquivalentExceptionSpec(
585         OldType->getAs<FunctionProtoType>(), Old->getLocation(),
586         NewType->getAs<FunctionProtoType>(), New->getLocation())) {
587     New->setInvalidDecl();
588   }
589 }
590 
591 /// CheckCXXDefaultArguments - Verify that the default arguments for a
592 /// function declaration are well-formed according to C++
593 /// [dcl.fct.default].
CheckCXXDefaultArguments(FunctionDecl * FD)594 void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
595   unsigned NumParams = FD->getNumParams();
596   unsigned p;
597 
598   bool IsLambda = FD->getOverloadedOperator() == OO_Call &&
599                   isa<CXXMethodDecl>(FD) &&
600                   cast<CXXMethodDecl>(FD)->getParent()->isLambda();
601 
602   // Find first parameter with a default argument
603   for (p = 0; p < NumParams; ++p) {
604     ParmVarDecl *Param = FD->getParamDecl(p);
605     if (Param->hasDefaultArg()) {
606       // C++11 [expr.prim.lambda]p5:
607       //   [...] Default arguments (8.3.6) shall not be specified in the
608       //   parameter-declaration-clause of a lambda-declarator.
609       //
610       // FIXME: Core issue 974 strikes this sentence, we only provide an
611       // extension warning.
612       if (IsLambda)
613         Diag(Param->getLocation(), diag::ext_lambda_default_arguments)
614           << Param->getDefaultArgRange();
615       break;
616     }
617   }
618 
619   // C++ [dcl.fct.default]p4:
620   //   In a given function declaration, all parameters
621   //   subsequent to a parameter with a default argument shall
622   //   have default arguments supplied in this or previous
623   //   declarations. A default argument shall not be redefined
624   //   by a later declaration (not even to the same value).
625   unsigned LastMissingDefaultArg = 0;
626   for (; p < NumParams; ++p) {
627     ParmVarDecl *Param = FD->getParamDecl(p);
628     if (!Param->hasDefaultArg()) {
629       if (Param->isInvalidDecl())
630         /* We already complained about this parameter. */;
631       else if (Param->getIdentifier())
632         Diag(Param->getLocation(),
633              diag::err_param_default_argument_missing_name)
634           << Param->getIdentifier();
635       else
636         Diag(Param->getLocation(),
637              diag::err_param_default_argument_missing);
638 
639       LastMissingDefaultArg = p;
640     }
641   }
642 
643   if (LastMissingDefaultArg > 0) {
644     // Some default arguments were missing. Clear out all of the
645     // default arguments up to (and including) the last missing
646     // default argument, so that we leave the function parameters
647     // in a semantically valid state.
648     for (p = 0; p <= LastMissingDefaultArg; ++p) {
649       ParmVarDecl *Param = FD->getParamDecl(p);
650       if (Param->hasDefaultArg()) {
651         Param->setDefaultArg(0);
652       }
653     }
654   }
655 }
656 
657 // CheckConstexprParameterTypes - Check whether a function's parameter types
658 // are all literal types. If so, return true. If not, produce a suitable
659 // diagnostic and return false.
CheckConstexprParameterTypes(Sema & SemaRef,const FunctionDecl * FD)660 static bool CheckConstexprParameterTypes(Sema &SemaRef,
661                                          const FunctionDecl *FD) {
662   unsigned ArgIndex = 0;
663   const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
664   for (FunctionProtoType::arg_type_iterator i = FT->arg_type_begin(),
665        e = FT->arg_type_end(); i != e; ++i, ++ArgIndex) {
666     const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
667     SourceLocation ParamLoc = PD->getLocation();
668     if (!(*i)->isDependentType() &&
669         SemaRef.RequireLiteralType(ParamLoc, *i,
670                             SemaRef.PDiag(diag::err_constexpr_non_literal_param)
671                                      << ArgIndex+1 << PD->getSourceRange()
672                                      << isa<CXXConstructorDecl>(FD)))
673       return false;
674   }
675   return true;
676 }
677 
678 // CheckConstexprFunctionDecl - Check whether a function declaration satisfies
679 // the requirements of a constexpr function definition or a constexpr
680 // constructor definition. If so, return true. If not, produce appropriate
681 // diagnostics and return false.
682 //
683 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
CheckConstexprFunctionDecl(const FunctionDecl * NewFD)684 bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD) {
685   const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
686   if (MD && MD->isInstance()) {
687     // C++11 [dcl.constexpr]p4:
688     //  The definition of a constexpr constructor shall satisfy the following
689     //  constraints:
690     //  - the class shall not have any virtual base classes;
691     const CXXRecordDecl *RD = MD->getParent();
692     if (RD->getNumVBases()) {
693       Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
694         << isa<CXXConstructorDecl>(NewFD) << RD->isStruct()
695         << RD->getNumVBases();
696       for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(),
697              E = RD->vbases_end(); I != E; ++I)
698         Diag(I->getLocStart(),
699              diag::note_constexpr_virtual_base_here) << I->getSourceRange();
700       return false;
701     }
702   }
703 
704   if (!isa<CXXConstructorDecl>(NewFD)) {
705     // C++11 [dcl.constexpr]p3:
706     //  The definition of a constexpr function shall satisfy the following
707     //  constraints:
708     // - it shall not be virtual;
709     const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
710     if (Method && Method->isVirtual()) {
711       Diag(NewFD->getLocation(), diag::err_constexpr_virtual);
712 
713       // If it's not obvious why this function is virtual, find an overridden
714       // function which uses the 'virtual' keyword.
715       const CXXMethodDecl *WrittenVirtual = Method;
716       while (!WrittenVirtual->isVirtualAsWritten())
717         WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
718       if (WrittenVirtual != Method)
719         Diag(WrittenVirtual->getLocation(),
720              diag::note_overridden_virtual_function);
721       return false;
722     }
723 
724     // - its return type shall be a literal type;
725     QualType RT = NewFD->getResultType();
726     if (!RT->isDependentType() &&
727         RequireLiteralType(NewFD->getLocation(), RT,
728                            PDiag(diag::err_constexpr_non_literal_return)))
729       return false;
730   }
731 
732   // - each of its parameter types shall be a literal type;
733   if (!CheckConstexprParameterTypes(*this, NewFD))
734     return false;
735 
736   return true;
737 }
738 
739 /// Check the given declaration statement is legal within a constexpr function
740 /// body. C++0x [dcl.constexpr]p3,p4.
741 ///
742 /// \return true if the body is OK, false if we have diagnosed a problem.
CheckConstexprDeclStmt(Sema & SemaRef,const FunctionDecl * Dcl,DeclStmt * DS)743 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
744                                    DeclStmt *DS) {
745   // C++0x [dcl.constexpr]p3 and p4:
746   //  The definition of a constexpr function(p3) or constructor(p4) [...] shall
747   //  contain only
748   for (DeclStmt::decl_iterator DclIt = DS->decl_begin(),
749          DclEnd = DS->decl_end(); DclIt != DclEnd; ++DclIt) {
750     switch ((*DclIt)->getKind()) {
751     case Decl::StaticAssert:
752     case Decl::Using:
753     case Decl::UsingShadow:
754     case Decl::UsingDirective:
755     case Decl::UnresolvedUsingTypename:
756       //   - static_assert-declarations
757       //   - using-declarations,
758       //   - using-directives,
759       continue;
760 
761     case Decl::Typedef:
762     case Decl::TypeAlias: {
763       //   - typedef declarations and alias-declarations that do not define
764       //     classes or enumerations,
765       TypedefNameDecl *TN = cast<TypedefNameDecl>(*DclIt);
766       if (TN->getUnderlyingType()->isVariablyModifiedType()) {
767         // Don't allow variably-modified types in constexpr functions.
768         TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
769         SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
770           << TL.getSourceRange() << TL.getType()
771           << isa<CXXConstructorDecl>(Dcl);
772         return false;
773       }
774       continue;
775     }
776 
777     case Decl::Enum:
778     case Decl::CXXRecord:
779       // As an extension, we allow the declaration (but not the definition) of
780       // classes and enumerations in all declarations, not just in typedef and
781       // alias declarations.
782       if (cast<TagDecl>(*DclIt)->isThisDeclarationADefinition()) {
783         SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_type_definition)
784           << isa<CXXConstructorDecl>(Dcl);
785         return false;
786       }
787       continue;
788 
789     case Decl::Var:
790       SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_var_declaration)
791         << isa<CXXConstructorDecl>(Dcl);
792       return false;
793 
794     default:
795       SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
796         << isa<CXXConstructorDecl>(Dcl);
797       return false;
798     }
799   }
800 
801   return true;
802 }
803 
804 /// Check that the given field is initialized within a constexpr constructor.
805 ///
806 /// \param Dcl The constexpr constructor being checked.
807 /// \param Field The field being checked. This may be a member of an anonymous
808 ///        struct or union nested within the class being checked.
809 /// \param Inits All declarations, including anonymous struct/union members and
810 ///        indirect members, for which any initialization was provided.
811 /// \param Diagnosed Set to true if an error is produced.
CheckConstexprCtorInitializer(Sema & SemaRef,const FunctionDecl * Dcl,FieldDecl * Field,llvm::SmallSet<Decl *,16> & Inits,bool & Diagnosed)812 static void CheckConstexprCtorInitializer(Sema &SemaRef,
813                                           const FunctionDecl *Dcl,
814                                           FieldDecl *Field,
815                                           llvm::SmallSet<Decl*, 16> &Inits,
816                                           bool &Diagnosed) {
817   if (Field->isUnnamedBitfield())
818     return;
819 
820   if (Field->isAnonymousStructOrUnion() &&
821       Field->getType()->getAsCXXRecordDecl()->isEmpty())
822     return;
823 
824   if (!Inits.count(Field)) {
825     if (!Diagnosed) {
826       SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
827       Diagnosed = true;
828     }
829     SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
830   } else if (Field->isAnonymousStructOrUnion()) {
831     const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
832     for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
833          I != E; ++I)
834       // If an anonymous union contains an anonymous struct of which any member
835       // is initialized, all members must be initialized.
836       if (!RD->isUnion() || Inits.count(*I))
837         CheckConstexprCtorInitializer(SemaRef, Dcl, *I, Inits, Diagnosed);
838   }
839 }
840 
841 /// Check the body for the given constexpr function declaration only contains
842 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
843 ///
844 /// \return true if the body is OK, false if we have diagnosed a problem.
CheckConstexprFunctionBody(const FunctionDecl * Dcl,Stmt * Body)845 bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) {
846   if (isa<CXXTryStmt>(Body)) {
847     // C++11 [dcl.constexpr]p3:
848     //  The definition of a constexpr function shall satisfy the following
849     //  constraints: [...]
850     // - its function-body shall be = delete, = default, or a
851     //   compound-statement
852     //
853     // C++11 [dcl.constexpr]p4:
854     //  In the definition of a constexpr constructor, [...]
855     // - its function-body shall not be a function-try-block;
856     Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
857       << isa<CXXConstructorDecl>(Dcl);
858     return false;
859   }
860 
861   // - its function-body shall be [...] a compound-statement that contains only
862   CompoundStmt *CompBody = cast<CompoundStmt>(Body);
863 
864   llvm::SmallVector<SourceLocation, 4> ReturnStmts;
865   for (CompoundStmt::body_iterator BodyIt = CompBody->body_begin(),
866          BodyEnd = CompBody->body_end(); BodyIt != BodyEnd; ++BodyIt) {
867     switch ((*BodyIt)->getStmtClass()) {
868     case Stmt::NullStmtClass:
869       //   - null statements,
870       continue;
871 
872     case Stmt::DeclStmtClass:
873       //   - static_assert-declarations
874       //   - using-declarations,
875       //   - using-directives,
876       //   - typedef declarations and alias-declarations that do not define
877       //     classes or enumerations,
878       if (!CheckConstexprDeclStmt(*this, Dcl, cast<DeclStmt>(*BodyIt)))
879         return false;
880       continue;
881 
882     case Stmt::ReturnStmtClass:
883       //   - and exactly one return statement;
884       if (isa<CXXConstructorDecl>(Dcl))
885         break;
886 
887       ReturnStmts.push_back((*BodyIt)->getLocStart());
888       continue;
889 
890     default:
891       break;
892     }
893 
894     Diag((*BodyIt)->getLocStart(), diag::err_constexpr_body_invalid_stmt)
895       << isa<CXXConstructorDecl>(Dcl);
896     return false;
897   }
898 
899   if (const CXXConstructorDecl *Constructor
900         = dyn_cast<CXXConstructorDecl>(Dcl)) {
901     const CXXRecordDecl *RD = Constructor->getParent();
902     // DR1359:
903     // - every non-variant non-static data member and base class sub-object
904     //   shall be initialized;
905     // - if the class is a non-empty union, or for each non-empty anonymous
906     //   union member of a non-union class, exactly one non-static data member
907     //   shall be initialized;
908     if (RD->isUnion()) {
909       if (Constructor->getNumCtorInitializers() == 0 && !RD->isEmpty()) {
910         Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
911         return false;
912       }
913     } else if (!Constructor->isDependentContext() &&
914                !Constructor->isDelegatingConstructor()) {
915       assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
916 
917       // Skip detailed checking if we have enough initializers, and we would
918       // allow at most one initializer per member.
919       bool AnyAnonStructUnionMembers = false;
920       unsigned Fields = 0;
921       for (CXXRecordDecl::field_iterator I = RD->field_begin(),
922            E = RD->field_end(); I != E; ++I, ++Fields) {
923         if ((*I)->isAnonymousStructOrUnion()) {
924           AnyAnonStructUnionMembers = true;
925           break;
926         }
927       }
928       if (AnyAnonStructUnionMembers ||
929           Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
930         // Check initialization of non-static data members. Base classes are
931         // always initialized so do not need to be checked. Dependent bases
932         // might not have initializers in the member initializer list.
933         llvm::SmallSet<Decl*, 16> Inits;
934         for (CXXConstructorDecl::init_const_iterator
935                I = Constructor->init_begin(), E = Constructor->init_end();
936              I != E; ++I) {
937           if (FieldDecl *FD = (*I)->getMember())
938             Inits.insert(FD);
939           else if (IndirectFieldDecl *ID = (*I)->getIndirectMember())
940             Inits.insert(ID->chain_begin(), ID->chain_end());
941         }
942 
943         bool Diagnosed = false;
944         for (CXXRecordDecl::field_iterator I = RD->field_begin(),
945              E = RD->field_end(); I != E; ++I)
946           CheckConstexprCtorInitializer(*this, Dcl, *I, Inits, Diagnosed);
947         if (Diagnosed)
948           return false;
949       }
950     }
951   } else {
952     if (ReturnStmts.empty()) {
953       Diag(Dcl->getLocation(), diag::err_constexpr_body_no_return);
954       return false;
955     }
956     if (ReturnStmts.size() > 1) {
957       Diag(ReturnStmts.back(), diag::err_constexpr_body_multiple_return);
958       for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
959         Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
960       return false;
961     }
962   }
963 
964   // C++11 [dcl.constexpr]p5:
965   //   if no function argument values exist such that the function invocation
966   //   substitution would produce a constant expression, the program is
967   //   ill-formed; no diagnostic required.
968   // C++11 [dcl.constexpr]p3:
969   //   - every constructor call and implicit conversion used in initializing the
970   //     return value shall be one of those allowed in a constant expression.
971   // C++11 [dcl.constexpr]p4:
972   //   - every constructor involved in initializing non-static data members and
973   //     base class sub-objects shall be a constexpr constructor.
974   llvm::SmallVector<PartialDiagnosticAt, 8> Diags;
975   if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
976     Diag(Dcl->getLocation(), diag::err_constexpr_function_never_constant_expr)
977       << isa<CXXConstructorDecl>(Dcl);
978     for (size_t I = 0, N = Diags.size(); I != N; ++I)
979       Diag(Diags[I].first, Diags[I].second);
980     return false;
981   }
982 
983   return true;
984 }
985 
986 /// isCurrentClassName - Determine whether the identifier II is the
987 /// name of the class type currently being defined. In the case of
988 /// nested classes, this will only return true if II is the name of
989 /// the innermost class.
isCurrentClassName(const IdentifierInfo & II,Scope *,const CXXScopeSpec * SS)990 bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
991                               const CXXScopeSpec *SS) {
992   assert(getLangOpts().CPlusPlus && "No class names in C!");
993 
994   CXXRecordDecl *CurDecl;
995   if (SS && SS->isSet() && !SS->isInvalid()) {
996     DeclContext *DC = computeDeclContext(*SS, true);
997     CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
998   } else
999     CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
1000 
1001   if (CurDecl && CurDecl->getIdentifier())
1002     return &II == CurDecl->getIdentifier();
1003   else
1004     return false;
1005 }
1006 
1007 /// \brief Check the validity of a C++ base class specifier.
1008 ///
1009 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
1010 /// and returns NULL otherwise.
1011 CXXBaseSpecifier *
CheckBaseSpecifier(CXXRecordDecl * Class,SourceRange SpecifierRange,bool Virtual,AccessSpecifier Access,TypeSourceInfo * TInfo,SourceLocation EllipsisLoc)1012 Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
1013                          SourceRange SpecifierRange,
1014                          bool Virtual, AccessSpecifier Access,
1015                          TypeSourceInfo *TInfo,
1016                          SourceLocation EllipsisLoc) {
1017   QualType BaseType = TInfo->getType();
1018 
1019   // C++ [class.union]p1:
1020   //   A union shall not have base classes.
1021   if (Class->isUnion()) {
1022     Diag(Class->getLocation(), diag::err_base_clause_on_union)
1023       << SpecifierRange;
1024     return 0;
1025   }
1026 
1027   if (EllipsisLoc.isValid() &&
1028       !TInfo->getType()->containsUnexpandedParameterPack()) {
1029     Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1030       << TInfo->getTypeLoc().getSourceRange();
1031     EllipsisLoc = SourceLocation();
1032   }
1033 
1034   if (BaseType->isDependentType())
1035     return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1036                                           Class->getTagKind() == TTK_Class,
1037                                           Access, TInfo, EllipsisLoc);
1038 
1039   SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
1040 
1041   // Base specifiers must be record types.
1042   if (!BaseType->isRecordType()) {
1043     Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
1044     return 0;
1045   }
1046 
1047   // C++ [class.union]p1:
1048   //   A union shall not be used as a base class.
1049   if (BaseType->isUnionType()) {
1050     Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
1051     return 0;
1052   }
1053 
1054   // C++ [class.derived]p2:
1055   //   The class-name in a base-specifier shall not be an incompletely
1056   //   defined class.
1057   if (RequireCompleteType(BaseLoc, BaseType,
1058                           PDiag(diag::err_incomplete_base_class)
1059                             << SpecifierRange)) {
1060     Class->setInvalidDecl();
1061     return 0;
1062   }
1063 
1064   // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
1065   RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
1066   assert(BaseDecl && "Record type has no declaration");
1067   BaseDecl = BaseDecl->getDefinition();
1068   assert(BaseDecl && "Base type is not incomplete, but has no definition");
1069   CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
1070   assert(CXXBaseDecl && "Base type is not a C++ type");
1071 
1072   // C++ [class]p3:
1073   //   If a class is marked final and it appears as a base-type-specifier in
1074   //   base-clause, the program is ill-formed.
1075   if (CXXBaseDecl->hasAttr<FinalAttr>()) {
1076     Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
1077       << CXXBaseDecl->getDeclName();
1078     Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
1079       << CXXBaseDecl->getDeclName();
1080     return 0;
1081   }
1082 
1083   if (BaseDecl->isInvalidDecl())
1084     Class->setInvalidDecl();
1085 
1086   // Create the base specifier.
1087   return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
1088                                         Class->getTagKind() == TTK_Class,
1089                                         Access, TInfo, EllipsisLoc);
1090 }
1091 
1092 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
1093 /// one entry in the base class list of a class specifier, for
1094 /// example:
1095 ///    class foo : public bar, virtual private baz {
1096 /// 'public bar' and 'virtual private baz' are each base-specifiers.
1097 BaseResult
ActOnBaseSpecifier(Decl * classdecl,SourceRange SpecifierRange,bool Virtual,AccessSpecifier Access,ParsedType basetype,SourceLocation BaseLoc,SourceLocation EllipsisLoc)1098 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
1099                          bool Virtual, AccessSpecifier Access,
1100                          ParsedType basetype, SourceLocation BaseLoc,
1101                          SourceLocation EllipsisLoc) {
1102   if (!classdecl)
1103     return true;
1104 
1105   AdjustDeclIfTemplate(classdecl);
1106   CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
1107   if (!Class)
1108     return true;
1109 
1110   TypeSourceInfo *TInfo = 0;
1111   GetTypeFromParser(basetype, &TInfo);
1112 
1113   if (EllipsisLoc.isInvalid() &&
1114       DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
1115                                       UPPC_BaseType))
1116     return true;
1117 
1118   if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
1119                                                       Virtual, Access, TInfo,
1120                                                       EllipsisLoc))
1121     return BaseSpec;
1122 
1123   return true;
1124 }
1125 
1126 /// \brief Performs the actual work of attaching the given base class
1127 /// specifiers to a C++ class.
AttachBaseSpecifiers(CXXRecordDecl * Class,CXXBaseSpecifier ** Bases,unsigned NumBases)1128 bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
1129                                 unsigned NumBases) {
1130  if (NumBases == 0)
1131     return false;
1132 
1133   // Used to keep track of which base types we have already seen, so
1134   // that we can properly diagnose redundant direct base types. Note
1135   // that the key is always the unqualified canonical type of the base
1136   // class.
1137   std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
1138 
1139   // Copy non-redundant base specifiers into permanent storage.
1140   unsigned NumGoodBases = 0;
1141   bool Invalid = false;
1142   for (unsigned idx = 0; idx < NumBases; ++idx) {
1143     QualType NewBaseType
1144       = Context.getCanonicalType(Bases[idx]->getType());
1145     NewBaseType = NewBaseType.getLocalUnqualifiedType();
1146 
1147     CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
1148     if (KnownBase) {
1149       // C++ [class.mi]p3:
1150       //   A class shall not be specified as a direct base class of a
1151       //   derived class more than once.
1152       Diag(Bases[idx]->getLocStart(),
1153            diag::err_duplicate_base_class)
1154         << KnownBase->getType()
1155         << Bases[idx]->getSourceRange();
1156 
1157       // Delete the duplicate base class specifier; we're going to
1158       // overwrite its pointer later.
1159       Context.Deallocate(Bases[idx]);
1160 
1161       Invalid = true;
1162     } else {
1163       // Okay, add this new base class.
1164       KnownBase = Bases[idx];
1165       Bases[NumGoodBases++] = Bases[idx];
1166       if (const RecordType *Record = NewBaseType->getAs<RecordType>())
1167         if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()))
1168           if (RD->hasAttr<WeakAttr>())
1169             Class->addAttr(::new (Context) WeakAttr(SourceRange(), Context));
1170     }
1171   }
1172 
1173   // Attach the remaining base class specifiers to the derived class.
1174   Class->setBases(Bases, NumGoodBases);
1175 
1176   // Delete the remaining (good) base class specifiers, since their
1177   // data has been copied into the CXXRecordDecl.
1178   for (unsigned idx = 0; idx < NumGoodBases; ++idx)
1179     Context.Deallocate(Bases[idx]);
1180 
1181   return Invalid;
1182 }
1183 
1184 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
1185 /// class, after checking whether there are any duplicate base
1186 /// classes.
ActOnBaseSpecifiers(Decl * ClassDecl,CXXBaseSpecifier ** Bases,unsigned NumBases)1187 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases,
1188                                unsigned NumBases) {
1189   if (!ClassDecl || !Bases || !NumBases)
1190     return;
1191 
1192   AdjustDeclIfTemplate(ClassDecl);
1193   AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl),
1194                        (CXXBaseSpecifier**)(Bases), NumBases);
1195 }
1196 
GetClassForType(QualType T)1197 static CXXRecordDecl *GetClassForType(QualType T) {
1198   if (const RecordType *RT = T->getAs<RecordType>())
1199     return cast<CXXRecordDecl>(RT->getDecl());
1200   else if (const InjectedClassNameType *ICT = T->getAs<InjectedClassNameType>())
1201     return ICT->getDecl();
1202   else
1203     return 0;
1204 }
1205 
1206 /// \brief Determine whether the type \p Derived is a C++ class that is
1207 /// derived from the type \p Base.
IsDerivedFrom(QualType Derived,QualType Base)1208 bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
1209   if (!getLangOpts().CPlusPlus)
1210     return false;
1211 
1212   CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1213   if (!DerivedRD)
1214     return false;
1215 
1216   CXXRecordDecl *BaseRD = GetClassForType(Base);
1217   if (!BaseRD)
1218     return false;
1219 
1220   // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
1221   return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
1222 }
1223 
1224 /// \brief Determine whether the type \p Derived is a C++ class that is
1225 /// derived from the type \p Base.
IsDerivedFrom(QualType Derived,QualType Base,CXXBasePaths & Paths)1226 bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
1227   if (!getLangOpts().CPlusPlus)
1228     return false;
1229 
1230   CXXRecordDecl *DerivedRD = GetClassForType(Derived);
1231   if (!DerivedRD)
1232     return false;
1233 
1234   CXXRecordDecl *BaseRD = GetClassForType(Base);
1235   if (!BaseRD)
1236     return false;
1237 
1238   return DerivedRD->isDerivedFrom(BaseRD, Paths);
1239 }
1240 
BuildBasePathArray(const CXXBasePaths & Paths,CXXCastPath & BasePathArray)1241 void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
1242                               CXXCastPath &BasePathArray) {
1243   assert(BasePathArray.empty() && "Base path array must be empty!");
1244   assert(Paths.isRecordingPaths() && "Must record paths!");
1245 
1246   const CXXBasePath &Path = Paths.front();
1247 
1248   // We first go backward and check if we have a virtual base.
1249   // FIXME: It would be better if CXXBasePath had the base specifier for
1250   // the nearest virtual base.
1251   unsigned Start = 0;
1252   for (unsigned I = Path.size(); I != 0; --I) {
1253     if (Path[I - 1].Base->isVirtual()) {
1254       Start = I - 1;
1255       break;
1256     }
1257   }
1258 
1259   // Now add all bases.
1260   for (unsigned I = Start, E = Path.size(); I != E; ++I)
1261     BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
1262 }
1263 
1264 /// \brief Determine whether the given base path includes a virtual
1265 /// base class.
BasePathInvolvesVirtualBase(const CXXCastPath & BasePath)1266 bool Sema::BasePathInvolvesVirtualBase(const CXXCastPath &BasePath) {
1267   for (CXXCastPath::const_iterator B = BasePath.begin(),
1268                                 BEnd = BasePath.end();
1269        B != BEnd; ++B)
1270     if ((*B)->isVirtual())
1271       return true;
1272 
1273   return false;
1274 }
1275 
1276 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
1277 /// conversion (where Derived and Base are class types) is
1278 /// well-formed, meaning that the conversion is unambiguous (and
1279 /// that all of the base classes are accessible). Returns true
1280 /// and emits a diagnostic if the code is ill-formed, returns false
1281 /// otherwise. Loc is the location where this routine should point to
1282 /// if there is an error, and Range is the source range to highlight
1283 /// if there is an error.
1284 bool
CheckDerivedToBaseConversion(QualType Derived,QualType Base,unsigned InaccessibleBaseID,unsigned AmbigiousBaseConvID,SourceLocation Loc,SourceRange Range,DeclarationName Name,CXXCastPath * BasePath)1285 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1286                                    unsigned InaccessibleBaseID,
1287                                    unsigned AmbigiousBaseConvID,
1288                                    SourceLocation Loc, SourceRange Range,
1289                                    DeclarationName Name,
1290                                    CXXCastPath *BasePath) {
1291   // First, determine whether the path from Derived to Base is
1292   // ambiguous. This is slightly more expensive than checking whether
1293   // the Derived to Base conversion exists, because here we need to
1294   // explore multiple paths to determine if there is an ambiguity.
1295   CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1296                      /*DetectVirtual=*/false);
1297   bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
1298   assert(DerivationOkay &&
1299          "Can only be used with a derived-to-base conversion");
1300   (void)DerivationOkay;
1301 
1302   if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
1303     if (InaccessibleBaseID) {
1304       // Check that the base class can be accessed.
1305       switch (CheckBaseClassAccess(Loc, Base, Derived, Paths.front(),
1306                                    InaccessibleBaseID)) {
1307         case AR_inaccessible:
1308           return true;
1309         case AR_accessible:
1310         case AR_dependent:
1311         case AR_delayed:
1312           break;
1313       }
1314     }
1315 
1316     // Build a base path if necessary.
1317     if (BasePath)
1318       BuildBasePathArray(Paths, *BasePath);
1319     return false;
1320   }
1321 
1322   // We know that the derived-to-base conversion is ambiguous, and
1323   // we're going to produce a diagnostic. Perform the derived-to-base
1324   // search just one more time to compute all of the possible paths so
1325   // that we can print them out. This is more expensive than any of
1326   // the previous derived-to-base checks we've done, but at this point
1327   // performance isn't as much of an issue.
1328   Paths.clear();
1329   Paths.setRecordingPaths(true);
1330   bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
1331   assert(StillOkay && "Can only be used with a derived-to-base conversion");
1332   (void)StillOkay;
1333 
1334   // Build up a textual representation of the ambiguous paths, e.g.,
1335   // D -> B -> A, that will be used to illustrate the ambiguous
1336   // conversions in the diagnostic. We only print one of the paths
1337   // to each base class subobject.
1338   std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
1339 
1340   Diag(Loc, AmbigiousBaseConvID)
1341   << Derived << Base << PathDisplayStr << Range << Name;
1342   return true;
1343 }
1344 
1345 bool
CheckDerivedToBaseConversion(QualType Derived,QualType Base,SourceLocation Loc,SourceRange Range,CXXCastPath * BasePath,bool IgnoreAccess)1346 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
1347                                    SourceLocation Loc, SourceRange Range,
1348                                    CXXCastPath *BasePath,
1349                                    bool IgnoreAccess) {
1350   return CheckDerivedToBaseConversion(Derived, Base,
1351                                       IgnoreAccess ? 0
1352                                        : diag::err_upcast_to_inaccessible_base,
1353                                       diag::err_ambiguous_derived_to_base_conv,
1354                                       Loc, Range, DeclarationName(),
1355                                       BasePath);
1356 }
1357 
1358 
1359 /// @brief Builds a string representing ambiguous paths from a
1360 /// specific derived class to different subobjects of the same base
1361 /// class.
1362 ///
1363 /// This function builds a string that can be used in error messages
1364 /// to show the different paths that one can take through the
1365 /// inheritance hierarchy to go from the derived class to different
1366 /// subobjects of a base class. The result looks something like this:
1367 /// @code
1368 /// struct D -> struct B -> struct A
1369 /// struct D -> struct C -> struct A
1370 /// @endcode
getAmbiguousPathsDisplayString(CXXBasePaths & Paths)1371 std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
1372   std::string PathDisplayStr;
1373   std::set<unsigned> DisplayedPaths;
1374   for (CXXBasePaths::paths_iterator Path = Paths.begin();
1375        Path != Paths.end(); ++Path) {
1376     if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
1377       // We haven't displayed a path to this particular base
1378       // class subobject yet.
1379       PathDisplayStr += "\n    ";
1380       PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
1381       for (CXXBasePath::const_iterator Element = Path->begin();
1382            Element != Path->end(); ++Element)
1383         PathDisplayStr += " -> " + Element->Base->getType().getAsString();
1384     }
1385   }
1386 
1387   return PathDisplayStr;
1388 }
1389 
1390 //===----------------------------------------------------------------------===//
1391 // C++ class member Handling
1392 //===----------------------------------------------------------------------===//
1393 
1394 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
ActOnAccessSpecifier(AccessSpecifier Access,SourceLocation ASLoc,SourceLocation ColonLoc,AttributeList * Attrs)1395 bool Sema::ActOnAccessSpecifier(AccessSpecifier Access,
1396                                 SourceLocation ASLoc,
1397                                 SourceLocation ColonLoc,
1398                                 AttributeList *Attrs) {
1399   assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
1400   AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
1401                                                   ASLoc, ColonLoc);
1402   CurContext->addHiddenDecl(ASDecl);
1403   return ProcessAccessDeclAttributeList(ASDecl, Attrs);
1404 }
1405 
1406 /// CheckOverrideControl - Check C++0x override control semantics.
CheckOverrideControl(const Decl * D)1407 void Sema::CheckOverrideControl(const Decl *D) {
1408   const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
1409   if (!MD || !MD->isVirtual())
1410     return;
1411 
1412   if (MD->isDependentContext())
1413     return;
1414 
1415   // C++0x [class.virtual]p3:
1416   //   If a virtual function is marked with the virt-specifier override and does
1417   //   not override a member function of a base class,
1418   //   the program is ill-formed.
1419   bool HasOverriddenMethods =
1420     MD->begin_overridden_methods() != MD->end_overridden_methods();
1421   if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods) {
1422     Diag(MD->getLocation(),
1423                  diag::err_function_marked_override_not_overriding)
1424       << MD->getDeclName();
1425     return;
1426   }
1427 }
1428 
1429 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
1430 /// function overrides a virtual member function marked 'final', according to
1431 /// C++0x [class.virtual]p3.
CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl * New,const CXXMethodDecl * Old)1432 bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
1433                                                   const CXXMethodDecl *Old) {
1434   if (!Old->hasAttr<FinalAttr>())
1435     return false;
1436 
1437   Diag(New->getLocation(), diag::err_final_function_overridden)
1438     << New->getDeclName();
1439   Diag(Old->getLocation(), diag::note_overridden_virtual_function);
1440   return true;
1441 }
1442 
1443 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
1444 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
1445 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
1446 /// one has been parsed, and 'HasDeferredInit' is true if an initializer is
1447 /// present but parsing it has been deferred.
1448 Decl *
ActOnCXXMemberDeclarator(Scope * S,AccessSpecifier AS,Declarator & D,MultiTemplateParamsArg TemplateParameterLists,Expr * BW,const VirtSpecifiers & VS,bool HasDeferredInit)1449 Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
1450                                MultiTemplateParamsArg TemplateParameterLists,
1451                                Expr *BW, const VirtSpecifiers &VS,
1452                                bool HasDeferredInit) {
1453   const DeclSpec &DS = D.getDeclSpec();
1454   DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
1455   DeclarationName Name = NameInfo.getName();
1456   SourceLocation Loc = NameInfo.getLoc();
1457 
1458   // For anonymous bitfields, the location should point to the type.
1459   if (Loc.isInvalid())
1460     Loc = D.getLocStart();
1461 
1462   Expr *BitWidth = static_cast<Expr*>(BW);
1463 
1464   assert(isa<CXXRecordDecl>(CurContext));
1465   assert(!DS.isFriendSpecified());
1466 
1467   bool isFunc = D.isDeclarationOfFunction();
1468 
1469   // C++ 9.2p6: A member shall not be declared to have automatic storage
1470   // duration (auto, register) or with the extern storage-class-specifier.
1471   // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
1472   // data members and cannot be applied to names declared const or static,
1473   // and cannot be applied to reference members.
1474   switch (DS.getStorageClassSpec()) {
1475     case DeclSpec::SCS_unspecified:
1476     case DeclSpec::SCS_typedef:
1477     case DeclSpec::SCS_static:
1478       // FALL THROUGH.
1479       break;
1480     case DeclSpec::SCS_mutable:
1481       if (isFunc) {
1482         if (DS.getStorageClassSpecLoc().isValid())
1483           Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
1484         else
1485           Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
1486 
1487         // FIXME: It would be nicer if the keyword was ignored only for this
1488         // declarator. Otherwise we could get follow-up errors.
1489         D.getMutableDeclSpec().ClearStorageClassSpecs();
1490       }
1491       break;
1492     default:
1493       if (DS.getStorageClassSpecLoc().isValid())
1494         Diag(DS.getStorageClassSpecLoc(),
1495              diag::err_storageclass_invalid_for_member);
1496       else
1497         Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
1498       D.getMutableDeclSpec().ClearStorageClassSpecs();
1499   }
1500 
1501   bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
1502                        DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
1503                       !isFunc);
1504 
1505   Decl *Member;
1506   if (isInstField) {
1507     CXXScopeSpec &SS = D.getCXXScopeSpec();
1508 
1509     // Data members must have identifiers for names.
1510     if (Name.getNameKind() != DeclarationName::Identifier) {
1511       Diag(Loc, diag::err_bad_variable_name)
1512         << Name;
1513       return 0;
1514     }
1515 
1516     IdentifierInfo *II = Name.getAsIdentifierInfo();
1517 
1518     // Member field could not be with "template" keyword.
1519     // So TemplateParameterLists should be empty in this case.
1520     if (TemplateParameterLists.size()) {
1521       TemplateParameterList* TemplateParams = TemplateParameterLists.get()[0];
1522       if (TemplateParams->size()) {
1523         // There is no such thing as a member field template.
1524         Diag(D.getIdentifierLoc(), diag::err_template_member)
1525             << II
1526             << SourceRange(TemplateParams->getTemplateLoc(),
1527                 TemplateParams->getRAngleLoc());
1528       } else {
1529         // There is an extraneous 'template<>' for this member.
1530         Diag(TemplateParams->getTemplateLoc(),
1531             diag::err_template_member_noparams)
1532             << II
1533             << SourceRange(TemplateParams->getTemplateLoc(),
1534                 TemplateParams->getRAngleLoc());
1535       }
1536       return 0;
1537     }
1538 
1539     if (SS.isSet() && !SS.isInvalid()) {
1540       // The user provided a superfluous scope specifier inside a class
1541       // definition:
1542       //
1543       // class X {
1544       //   int X::member;
1545       // };
1546       if (DeclContext *DC = computeDeclContext(SS, false))
1547         diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc());
1548       else
1549         Diag(D.getIdentifierLoc(), diag::err_member_qualification)
1550           << Name << SS.getRange();
1551 
1552       SS.clear();
1553     }
1554 
1555     Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
1556                          HasDeferredInit, AS);
1557     assert(Member && "HandleField never returns null");
1558   } else {
1559     assert(!HasDeferredInit);
1560 
1561     Member = HandleDeclarator(S, D, move(TemplateParameterLists));
1562     if (!Member) {
1563       return 0;
1564     }
1565 
1566     // Non-instance-fields can't have a bitfield.
1567     if (BitWidth) {
1568       if (Member->isInvalidDecl()) {
1569         // don't emit another diagnostic.
1570       } else if (isa<VarDecl>(Member)) {
1571         // C++ 9.6p3: A bit-field shall not be a static member.
1572         // "static member 'A' cannot be a bit-field"
1573         Diag(Loc, diag::err_static_not_bitfield)
1574           << Name << BitWidth->getSourceRange();
1575       } else if (isa<TypedefDecl>(Member)) {
1576         // "typedef member 'x' cannot be a bit-field"
1577         Diag(Loc, diag::err_typedef_not_bitfield)
1578           << Name << BitWidth->getSourceRange();
1579       } else {
1580         // A function typedef ("typedef int f(); f a;").
1581         // C++ 9.6p3: A bit-field shall have integral or enumeration type.
1582         Diag(Loc, diag::err_not_integral_type_bitfield)
1583           << Name << cast<ValueDecl>(Member)->getType()
1584           << BitWidth->getSourceRange();
1585       }
1586 
1587       BitWidth = 0;
1588       Member->setInvalidDecl();
1589     }
1590 
1591     Member->setAccess(AS);
1592 
1593     // If we have declared a member function template, set the access of the
1594     // templated declaration as well.
1595     if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
1596       FunTmpl->getTemplatedDecl()->setAccess(AS);
1597   }
1598 
1599   if (VS.isOverrideSpecified()) {
1600     CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1601     if (!MD || !MD->isVirtual()) {
1602       Diag(Member->getLocStart(),
1603            diag::override_keyword_only_allowed_on_virtual_member_functions)
1604         << "override" << FixItHint::CreateRemoval(VS.getOverrideLoc());
1605     } else
1606       MD->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context));
1607   }
1608   if (VS.isFinalSpecified()) {
1609     CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
1610     if (!MD || !MD->isVirtual()) {
1611       Diag(Member->getLocStart(),
1612            diag::override_keyword_only_allowed_on_virtual_member_functions)
1613       << "final" << FixItHint::CreateRemoval(VS.getFinalLoc());
1614     } else
1615       MD->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context));
1616   }
1617 
1618   if (VS.getLastLocation().isValid()) {
1619     // Update the end location of a method that has a virt-specifiers.
1620     if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
1621       MD->setRangeEnd(VS.getLastLocation());
1622   }
1623 
1624   CheckOverrideControl(Member);
1625 
1626   assert((Name || isInstField) && "No identifier for non-field ?");
1627 
1628   if (isInstField)
1629     FieldCollector->Add(cast<FieldDecl>(Member));
1630   return Member;
1631 }
1632 
1633 /// ActOnCXXInClassMemberInitializer - This is invoked after parsing an
1634 /// in-class initializer for a non-static C++ class member, and after
1635 /// instantiating an in-class initializer in a class template. Such actions
1636 /// are deferred until the class is complete.
1637 void
ActOnCXXInClassMemberInitializer(Decl * D,SourceLocation EqualLoc,Expr * InitExpr)1638 Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation EqualLoc,
1639                                        Expr *InitExpr) {
1640   FieldDecl *FD = cast<FieldDecl>(D);
1641 
1642   if (!InitExpr) {
1643     FD->setInvalidDecl();
1644     FD->removeInClassInitializer();
1645     return;
1646   }
1647 
1648   if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
1649     FD->setInvalidDecl();
1650     FD->removeInClassInitializer();
1651     return;
1652   }
1653 
1654   ExprResult Init = InitExpr;
1655   if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
1656     if (isa<InitListExpr>(InitExpr) && isStdInitializerList(FD->getType(), 0)) {
1657       Diag(FD->getLocation(), diag::warn_dangling_std_initializer_list)
1658         << /*at end of ctor*/1 << InitExpr->getSourceRange();
1659     }
1660     Expr **Inits = &InitExpr;
1661     unsigned NumInits = 1;
1662     InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
1663     InitializationKind Kind = EqualLoc.isInvalid()
1664         ? InitializationKind::CreateDirectList(InitExpr->getLocStart())
1665         : InitializationKind::CreateCopy(InitExpr->getLocStart(), EqualLoc);
1666     InitializationSequence Seq(*this, Entity, Kind, Inits, NumInits);
1667     Init = Seq.Perform(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
1668     if (Init.isInvalid()) {
1669       FD->setInvalidDecl();
1670       return;
1671     }
1672 
1673     CheckImplicitConversions(Init.get(), EqualLoc);
1674   }
1675 
1676   // C++0x [class.base.init]p7:
1677   //   The initialization of each base and member constitutes a
1678   //   full-expression.
1679   Init = MaybeCreateExprWithCleanups(Init);
1680   if (Init.isInvalid()) {
1681     FD->setInvalidDecl();
1682     return;
1683   }
1684 
1685   InitExpr = Init.release();
1686 
1687   FD->setInClassInitializer(InitExpr);
1688 }
1689 
1690 /// \brief Find the direct and/or virtual base specifiers that
1691 /// correspond to the given base type, for use in base initialization
1692 /// within a constructor.
FindBaseInitializer(Sema & SemaRef,CXXRecordDecl * ClassDecl,QualType BaseType,const CXXBaseSpecifier * & DirectBaseSpec,const CXXBaseSpecifier * & VirtualBaseSpec)1693 static bool FindBaseInitializer(Sema &SemaRef,
1694                                 CXXRecordDecl *ClassDecl,
1695                                 QualType BaseType,
1696                                 const CXXBaseSpecifier *&DirectBaseSpec,
1697                                 const CXXBaseSpecifier *&VirtualBaseSpec) {
1698   // First, check for a direct base class.
1699   DirectBaseSpec = 0;
1700   for (CXXRecordDecl::base_class_const_iterator Base
1701          = ClassDecl->bases_begin();
1702        Base != ClassDecl->bases_end(); ++Base) {
1703     if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
1704       // We found a direct base of this type. That's what we're
1705       // initializing.
1706       DirectBaseSpec = &*Base;
1707       break;
1708     }
1709   }
1710 
1711   // Check for a virtual base class.
1712   // FIXME: We might be able to short-circuit this if we know in advance that
1713   // there are no virtual bases.
1714   VirtualBaseSpec = 0;
1715   if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
1716     // We haven't found a base yet; search the class hierarchy for a
1717     // virtual base class.
1718     CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1719                        /*DetectVirtual=*/false);
1720     if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl),
1721                               BaseType, Paths)) {
1722       for (CXXBasePaths::paths_iterator Path = Paths.begin();
1723            Path != Paths.end(); ++Path) {
1724         if (Path->back().Base->isVirtual()) {
1725           VirtualBaseSpec = Path->back().Base;
1726           break;
1727         }
1728       }
1729     }
1730   }
1731 
1732   return DirectBaseSpec || VirtualBaseSpec;
1733 }
1734 
1735 /// \brief Handle a C++ member initializer using braced-init-list syntax.
1736 MemInitResult
ActOnMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,Expr * InitList,SourceLocation EllipsisLoc)1737 Sema::ActOnMemInitializer(Decl *ConstructorD,
1738                           Scope *S,
1739                           CXXScopeSpec &SS,
1740                           IdentifierInfo *MemberOrBase,
1741                           ParsedType TemplateTypeTy,
1742                           const DeclSpec &DS,
1743                           SourceLocation IdLoc,
1744                           Expr *InitList,
1745                           SourceLocation EllipsisLoc) {
1746   return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1747                              DS, IdLoc, InitList,
1748                              EllipsisLoc);
1749 }
1750 
1751 /// \brief Handle a C++ member initializer using parentheses syntax.
1752 MemInitResult
ActOnMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,SourceLocation LParenLoc,Expr ** Args,unsigned NumArgs,SourceLocation RParenLoc,SourceLocation EllipsisLoc)1753 Sema::ActOnMemInitializer(Decl *ConstructorD,
1754                           Scope *S,
1755                           CXXScopeSpec &SS,
1756                           IdentifierInfo *MemberOrBase,
1757                           ParsedType TemplateTypeTy,
1758                           const DeclSpec &DS,
1759                           SourceLocation IdLoc,
1760                           SourceLocation LParenLoc,
1761                           Expr **Args, unsigned NumArgs,
1762                           SourceLocation RParenLoc,
1763                           SourceLocation EllipsisLoc) {
1764   Expr *List = new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
1765                                            RParenLoc);
1766   return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
1767                              DS, IdLoc, List, EllipsisLoc);
1768 }
1769 
1770 namespace {
1771 
1772 // Callback to only accept typo corrections that can be a valid C++ member
1773 // intializer: either a non-static field member or a base class.
1774 class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
1775  public:
MemInitializerValidatorCCC(CXXRecordDecl * ClassDecl)1776   explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
1777       : ClassDecl(ClassDecl) {}
1778 
ValidateCandidate(const TypoCorrection & candidate)1779   virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1780     if (NamedDecl *ND = candidate.getCorrectionDecl()) {
1781       if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
1782         return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
1783       else
1784         return isa<TypeDecl>(ND);
1785     }
1786     return false;
1787   }
1788 
1789  private:
1790   CXXRecordDecl *ClassDecl;
1791 };
1792 
1793 }
1794 
1795 /// \brief Handle a C++ member initializer.
1796 MemInitResult
BuildMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,Expr * Init,SourceLocation EllipsisLoc)1797 Sema::BuildMemInitializer(Decl *ConstructorD,
1798                           Scope *S,
1799                           CXXScopeSpec &SS,
1800                           IdentifierInfo *MemberOrBase,
1801                           ParsedType TemplateTypeTy,
1802                           const DeclSpec &DS,
1803                           SourceLocation IdLoc,
1804                           Expr *Init,
1805                           SourceLocation EllipsisLoc) {
1806   if (!ConstructorD)
1807     return true;
1808 
1809   AdjustDeclIfTemplate(ConstructorD);
1810 
1811   CXXConstructorDecl *Constructor
1812     = dyn_cast<CXXConstructorDecl>(ConstructorD);
1813   if (!Constructor) {
1814     // The user wrote a constructor initializer on a function that is
1815     // not a C++ constructor. Ignore the error for now, because we may
1816     // have more member initializers coming; we'll diagnose it just
1817     // once in ActOnMemInitializers.
1818     return true;
1819   }
1820 
1821   CXXRecordDecl *ClassDecl = Constructor->getParent();
1822 
1823   // C++ [class.base.init]p2:
1824   //   Names in a mem-initializer-id are looked up in the scope of the
1825   //   constructor's class and, if not found in that scope, are looked
1826   //   up in the scope containing the constructor's definition.
1827   //   [Note: if the constructor's class contains a member with the
1828   //   same name as a direct or virtual base class of the class, a
1829   //   mem-initializer-id naming the member or base class and composed
1830   //   of a single identifier refers to the class member. A
1831   //   mem-initializer-id for the hidden base class may be specified
1832   //   using a qualified name. ]
1833   if (!SS.getScopeRep() && !TemplateTypeTy) {
1834     // Look for a member, first.
1835     DeclContext::lookup_result Result
1836       = ClassDecl->lookup(MemberOrBase);
1837     if (Result.first != Result.second) {
1838       ValueDecl *Member;
1839       if ((Member = dyn_cast<FieldDecl>(*Result.first)) ||
1840           (Member = dyn_cast<IndirectFieldDecl>(*Result.first))) {
1841         if (EllipsisLoc.isValid())
1842           Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
1843             << MemberOrBase
1844             << SourceRange(IdLoc, Init->getSourceRange().getEnd());
1845 
1846         return BuildMemberInitializer(Member, Init, IdLoc);
1847       }
1848     }
1849   }
1850   // It didn't name a member, so see if it names a class.
1851   QualType BaseType;
1852   TypeSourceInfo *TInfo = 0;
1853 
1854   if (TemplateTypeTy) {
1855     BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
1856   } else if (DS.getTypeSpecType() == TST_decltype) {
1857     BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
1858   } else {
1859     LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
1860     LookupParsedName(R, S, &SS);
1861 
1862     TypeDecl *TyD = R.getAsSingle<TypeDecl>();
1863     if (!TyD) {
1864       if (R.isAmbiguous()) return true;
1865 
1866       // We don't want access-control diagnostics here.
1867       R.suppressDiagnostics();
1868 
1869       if (SS.isSet() && isDependentScopeSpecifier(SS)) {
1870         bool NotUnknownSpecialization = false;
1871         DeclContext *DC = computeDeclContext(SS, false);
1872         if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
1873           NotUnknownSpecialization = !Record->hasAnyDependentBases();
1874 
1875         if (!NotUnknownSpecialization) {
1876           // When the scope specifier can refer to a member of an unknown
1877           // specialization, we take it as a type name.
1878           BaseType = CheckTypenameType(ETK_None, SourceLocation(),
1879                                        SS.getWithLocInContext(Context),
1880                                        *MemberOrBase, IdLoc);
1881           if (BaseType.isNull())
1882             return true;
1883 
1884           R.clear();
1885           R.setLookupName(MemberOrBase);
1886         }
1887       }
1888 
1889       // If no results were found, try to correct typos.
1890       TypoCorrection Corr;
1891       MemInitializerValidatorCCC Validator(ClassDecl);
1892       if (R.empty() && BaseType.isNull() &&
1893           (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
1894                               Validator, ClassDecl))) {
1895         std::string CorrectedStr(Corr.getAsString(getLangOpts()));
1896         std::string CorrectedQuotedStr(Corr.getQuoted(getLangOpts()));
1897         if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
1898           // We have found a non-static data member with a similar
1899           // name to what was typed; complain and initialize that
1900           // member.
1901           Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1902             << MemberOrBase << true << CorrectedQuotedStr
1903             << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1904           Diag(Member->getLocation(), diag::note_previous_decl)
1905             << CorrectedQuotedStr;
1906 
1907           return BuildMemberInitializer(Member, Init, IdLoc);
1908         } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
1909           const CXXBaseSpecifier *DirectBaseSpec;
1910           const CXXBaseSpecifier *VirtualBaseSpec;
1911           if (FindBaseInitializer(*this, ClassDecl,
1912                                   Context.getTypeDeclType(Type),
1913                                   DirectBaseSpec, VirtualBaseSpec)) {
1914             // We have found a direct or virtual base class with a
1915             // similar name to what was typed; complain and initialize
1916             // that base class.
1917             Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
1918               << MemberOrBase << false << CorrectedQuotedStr
1919               << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr);
1920 
1921             const CXXBaseSpecifier *BaseSpec = DirectBaseSpec? DirectBaseSpec
1922                                                              : VirtualBaseSpec;
1923             Diag(BaseSpec->getLocStart(),
1924                  diag::note_base_class_specified_here)
1925               << BaseSpec->getType()
1926               << BaseSpec->getSourceRange();
1927 
1928             TyD = Type;
1929           }
1930         }
1931       }
1932 
1933       if (!TyD && BaseType.isNull()) {
1934         Diag(IdLoc, diag::err_mem_init_not_member_or_class)
1935           << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
1936         return true;
1937       }
1938     }
1939 
1940     if (BaseType.isNull()) {
1941       BaseType = Context.getTypeDeclType(TyD);
1942       if (SS.isSet()) {
1943         NestedNameSpecifier *Qualifier =
1944           static_cast<NestedNameSpecifier*>(SS.getScopeRep());
1945 
1946         // FIXME: preserve source range information
1947         BaseType = Context.getElaboratedType(ETK_None, Qualifier, BaseType);
1948       }
1949     }
1950   }
1951 
1952   if (!TInfo)
1953     TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
1954 
1955   return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
1956 }
1957 
1958 /// Checks a member initializer expression for cases where reference (or
1959 /// pointer) members are bound to by-value parameters (or their addresses).
CheckForDanglingReferenceOrPointer(Sema & S,ValueDecl * Member,Expr * Init,SourceLocation IdLoc)1960 static void CheckForDanglingReferenceOrPointer(Sema &S, ValueDecl *Member,
1961                                                Expr *Init,
1962                                                SourceLocation IdLoc) {
1963   QualType MemberTy = Member->getType();
1964 
1965   // We only handle pointers and references currently.
1966   // FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
1967   if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
1968     return;
1969 
1970   const bool IsPointer = MemberTy->isPointerType();
1971   if (IsPointer) {
1972     if (const UnaryOperator *Op
1973           = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
1974       // The only case we're worried about with pointers requires taking the
1975       // address.
1976       if (Op->getOpcode() != UO_AddrOf)
1977         return;
1978 
1979       Init = Op->getSubExpr();
1980     } else {
1981       // We only handle address-of expression initializers for pointers.
1982       return;
1983     }
1984   }
1985 
1986   if (isa<MaterializeTemporaryExpr>(Init->IgnoreParens())) {
1987     // Taking the address of a temporary will be diagnosed as a hard error.
1988     if (IsPointer)
1989       return;
1990 
1991     S.Diag(Init->getExprLoc(), diag::warn_bind_ref_member_to_temporary)
1992       << Member << Init->getSourceRange();
1993   } else if (const DeclRefExpr *DRE
1994                = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
1995     // We only warn when referring to a non-reference parameter declaration.
1996     const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
1997     if (!Parameter || Parameter->getType()->isReferenceType())
1998       return;
1999 
2000     S.Diag(Init->getExprLoc(),
2001            IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
2002                      : diag::warn_bind_ref_member_to_parameter)
2003       << Member << Parameter << Init->getSourceRange();
2004   } else {
2005     // Other initializers are fine.
2006     return;
2007   }
2008 
2009   S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
2010     << (unsigned)IsPointer;
2011 }
2012 
2013 /// Checks an initializer expression for use of uninitialized fields, such as
2014 /// containing the field that is being initialized. Returns true if there is an
2015 /// uninitialized field was used an updates the SourceLocation parameter; false
2016 /// otherwise.
InitExprContainsUninitializedFields(const Stmt * S,const ValueDecl * LhsField,SourceLocation * L)2017 static bool InitExprContainsUninitializedFields(const Stmt *S,
2018                                                 const ValueDecl *LhsField,
2019                                                 SourceLocation *L) {
2020   assert(isa<FieldDecl>(LhsField) || isa<IndirectFieldDecl>(LhsField));
2021 
2022   if (isa<CallExpr>(S)) {
2023     // Do not descend into function calls or constructors, as the use
2024     // of an uninitialized field may be valid. One would have to inspect
2025     // the contents of the function/ctor to determine if it is safe or not.
2026     // i.e. Pass-by-value is never safe, but pass-by-reference and pointers
2027     // may be safe, depending on what the function/ctor does.
2028     return false;
2029   }
2030   if (const MemberExpr *ME = dyn_cast<MemberExpr>(S)) {
2031     const NamedDecl *RhsField = ME->getMemberDecl();
2032 
2033     if (const VarDecl *VD = dyn_cast<VarDecl>(RhsField)) {
2034       // The member expression points to a static data member.
2035       assert(VD->isStaticDataMember() &&
2036              "Member points to non-static data member!");
2037       (void)VD;
2038       return false;
2039     }
2040 
2041     if (isa<EnumConstantDecl>(RhsField)) {
2042       // The member expression points to an enum.
2043       return false;
2044     }
2045 
2046     if (RhsField == LhsField) {
2047       // Initializing a field with itself. Throw a warning.
2048       // But wait; there are exceptions!
2049       // Exception #1:  The field may not belong to this record.
2050       // e.g. Foo(const Foo& rhs) : A(rhs.A) {}
2051       const Expr *base = ME->getBase();
2052       if (base != NULL && !isa<CXXThisExpr>(base->IgnoreParenCasts())) {
2053         // Even though the field matches, it does not belong to this record.
2054         return false;
2055       }
2056       // None of the exceptions triggered; return true to indicate an
2057       // uninitialized field was used.
2058       *L = ME->getMemberLoc();
2059       return true;
2060     }
2061   } else if (isa<UnaryExprOrTypeTraitExpr>(S)) {
2062     // sizeof/alignof doesn't reference contents, do not warn.
2063     return false;
2064   } else if (const UnaryOperator *UOE = dyn_cast<UnaryOperator>(S)) {
2065     // address-of doesn't reference contents (the pointer may be dereferenced
2066     // in the same expression but it would be rare; and weird).
2067     if (UOE->getOpcode() == UO_AddrOf)
2068       return false;
2069   }
2070   for (Stmt::const_child_range it = S->children(); it; ++it) {
2071     if (!*it) {
2072       // An expression such as 'member(arg ?: "")' may trigger this.
2073       continue;
2074     }
2075     if (InitExprContainsUninitializedFields(*it, LhsField, L))
2076       return true;
2077   }
2078   return false;
2079 }
2080 
2081 MemInitResult
BuildMemberInitializer(ValueDecl * Member,Expr * Init,SourceLocation IdLoc)2082 Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
2083                              SourceLocation IdLoc) {
2084   FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
2085   IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
2086   assert((DirectMember || IndirectMember) &&
2087          "Member must be a FieldDecl or IndirectFieldDecl");
2088 
2089   if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2090     return true;
2091 
2092   if (Member->isInvalidDecl())
2093     return true;
2094 
2095   // Diagnose value-uses of fields to initialize themselves, e.g.
2096   //   foo(foo)
2097   // where foo is not also a parameter to the constructor.
2098   // TODO: implement -Wuninitialized and fold this into that framework.
2099   Expr **Args;
2100   unsigned NumArgs;
2101   if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2102     Args = ParenList->getExprs();
2103     NumArgs = ParenList->getNumExprs();
2104   } else {
2105     InitListExpr *InitList = cast<InitListExpr>(Init);
2106     Args = InitList->getInits();
2107     NumArgs = InitList->getNumInits();
2108   }
2109   for (unsigned i = 0; i < NumArgs; ++i) {
2110     SourceLocation L;
2111     if (InitExprContainsUninitializedFields(Args[i], Member, &L)) {
2112       // FIXME: Return true in the case when other fields are used before being
2113       // uninitialized. For example, let this field be the i'th field. When
2114       // initializing the i'th field, throw a warning if any of the >= i'th
2115       // fields are used, as they are not yet initialized.
2116       // Right now we are only handling the case where the i'th field uses
2117       // itself in its initializer.
2118       Diag(L, diag::warn_field_is_uninit);
2119     }
2120   }
2121 
2122   SourceRange InitRange = Init->getSourceRange();
2123 
2124   if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
2125     // Can't check initialization for a member of dependent type or when
2126     // any of the arguments are type-dependent expressions.
2127     DiscardCleanupsInEvaluationContext();
2128   } else {
2129     bool InitList = false;
2130     if (isa<InitListExpr>(Init)) {
2131       InitList = true;
2132       Args = &Init;
2133       NumArgs = 1;
2134 
2135       if (isStdInitializerList(Member->getType(), 0)) {
2136         Diag(IdLoc, diag::warn_dangling_std_initializer_list)
2137             << /*at end of ctor*/1 << InitRange;
2138       }
2139     }
2140 
2141     // Initialize the member.
2142     InitializedEntity MemberEntity =
2143       DirectMember ? InitializedEntity::InitializeMember(DirectMember, 0)
2144                    : InitializedEntity::InitializeMember(IndirectMember, 0);
2145     InitializationKind Kind =
2146       InitList ? InitializationKind::CreateDirectList(IdLoc)
2147                : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
2148                                                   InitRange.getEnd());
2149 
2150     InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
2151     ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind,
2152                                             MultiExprArg(*this, Args, NumArgs),
2153                                             0);
2154     if (MemberInit.isInvalid())
2155       return true;
2156 
2157     CheckImplicitConversions(MemberInit.get(),
2158                              InitRange.getBegin());
2159 
2160     // C++0x [class.base.init]p7:
2161     //   The initialization of each base and member constitutes a
2162     //   full-expression.
2163     MemberInit = MaybeCreateExprWithCleanups(MemberInit);
2164     if (MemberInit.isInvalid())
2165       return true;
2166 
2167     // If we are in a dependent context, template instantiation will
2168     // perform this type-checking again. Just save the arguments that we
2169     // received.
2170     // FIXME: This isn't quite ideal, since our ASTs don't capture all
2171     // of the information that we have about the member
2172     // initializer. However, deconstructing the ASTs is a dicey process,
2173     // and this approach is far more likely to get the corner cases right.
2174     if (CurContext->isDependentContext()) {
2175       // The existing Init will do fine.
2176     } else {
2177       Init = MemberInit.get();
2178       CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
2179     }
2180   }
2181 
2182   if (DirectMember) {
2183     return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
2184                                             InitRange.getBegin(), Init,
2185                                             InitRange.getEnd());
2186   } else {
2187     return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
2188                                             InitRange.getBegin(), Init,
2189                                             InitRange.getEnd());
2190   }
2191 }
2192 
2193 MemInitResult
BuildDelegatingInitializer(TypeSourceInfo * TInfo,Expr * Init,CXXRecordDecl * ClassDecl)2194 Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
2195                                  CXXRecordDecl *ClassDecl) {
2196   SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
2197   if (!LangOpts.CPlusPlus0x)
2198     return Diag(NameLoc, diag::err_delegating_ctor)
2199       << TInfo->getTypeLoc().getLocalSourceRange();
2200   Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
2201 
2202   bool InitList = true;
2203   Expr **Args = &Init;
2204   unsigned NumArgs = 1;
2205   if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2206     InitList = false;
2207     Args = ParenList->getExprs();
2208     NumArgs = ParenList->getNumExprs();
2209   }
2210 
2211   SourceRange InitRange = Init->getSourceRange();
2212   // Initialize the object.
2213   InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
2214                                      QualType(ClassDecl->getTypeForDecl(), 0));
2215   InitializationKind Kind =
2216     InitList ? InitializationKind::CreateDirectList(NameLoc)
2217              : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
2218                                                 InitRange.getEnd());
2219   InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args, NumArgs);
2220   ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
2221                                               MultiExprArg(*this, Args,NumArgs),
2222                                               0);
2223   if (DelegationInit.isInvalid())
2224     return true;
2225 
2226   assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
2227          "Delegating constructor with no target?");
2228 
2229   CheckImplicitConversions(DelegationInit.get(), InitRange.getBegin());
2230 
2231   // C++0x [class.base.init]p7:
2232   //   The initialization of each base and member constitutes a
2233   //   full-expression.
2234   DelegationInit = MaybeCreateExprWithCleanups(DelegationInit);
2235   if (DelegationInit.isInvalid())
2236     return true;
2237 
2238   return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
2239                                           DelegationInit.takeAs<Expr>(),
2240                                           InitRange.getEnd());
2241 }
2242 
2243 MemInitResult
BuildBaseInitializer(QualType BaseType,TypeSourceInfo * BaseTInfo,Expr * Init,CXXRecordDecl * ClassDecl,SourceLocation EllipsisLoc)2244 Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
2245                            Expr *Init, CXXRecordDecl *ClassDecl,
2246                            SourceLocation EllipsisLoc) {
2247   SourceLocation BaseLoc
2248     = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
2249 
2250   if (!BaseType->isDependentType() && !BaseType->isRecordType())
2251     return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
2252              << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2253 
2254   // C++ [class.base.init]p2:
2255   //   [...] Unless the mem-initializer-id names a nonstatic data
2256   //   member of the constructor's class or a direct or virtual base
2257   //   of that class, the mem-initializer is ill-formed. A
2258   //   mem-initializer-list can initialize a base class using any
2259   //   name that denotes that base class type.
2260   bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
2261 
2262   SourceRange InitRange = Init->getSourceRange();
2263   if (EllipsisLoc.isValid()) {
2264     // This is a pack expansion.
2265     if (!BaseType->containsUnexpandedParameterPack())  {
2266       Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2267         << SourceRange(BaseLoc, InitRange.getEnd());
2268 
2269       EllipsisLoc = SourceLocation();
2270     }
2271   } else {
2272     // Check for any unexpanded parameter packs.
2273     if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
2274       return true;
2275 
2276     if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
2277       return true;
2278   }
2279 
2280   // Check for direct and virtual base classes.
2281   const CXXBaseSpecifier *DirectBaseSpec = 0;
2282   const CXXBaseSpecifier *VirtualBaseSpec = 0;
2283   if (!Dependent) {
2284     if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
2285                                        BaseType))
2286       return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
2287 
2288     FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
2289                         VirtualBaseSpec);
2290 
2291     // C++ [base.class.init]p2:
2292     // Unless the mem-initializer-id names a nonstatic data member of the
2293     // constructor's class or a direct or virtual base of that class, the
2294     // mem-initializer is ill-formed.
2295     if (!DirectBaseSpec && !VirtualBaseSpec) {
2296       // If the class has any dependent bases, then it's possible that
2297       // one of those types will resolve to the same type as
2298       // BaseType. Therefore, just treat this as a dependent base
2299       // class initialization.  FIXME: Should we try to check the
2300       // initialization anyway? It seems odd.
2301       if (ClassDecl->hasAnyDependentBases())
2302         Dependent = true;
2303       else
2304         return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
2305           << BaseType << Context.getTypeDeclType(ClassDecl)
2306           << BaseTInfo->getTypeLoc().getLocalSourceRange();
2307     }
2308   }
2309 
2310   if (Dependent) {
2311     DiscardCleanupsInEvaluationContext();
2312 
2313     return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2314                                             /*IsVirtual=*/false,
2315                                             InitRange.getBegin(), Init,
2316                                             InitRange.getEnd(), EllipsisLoc);
2317   }
2318 
2319   // C++ [base.class.init]p2:
2320   //   If a mem-initializer-id is ambiguous because it designates both
2321   //   a direct non-virtual base class and an inherited virtual base
2322   //   class, the mem-initializer is ill-formed.
2323   if (DirectBaseSpec && VirtualBaseSpec)
2324     return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
2325       << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
2326 
2327   CXXBaseSpecifier *BaseSpec = const_cast<CXXBaseSpecifier *>(DirectBaseSpec);
2328   if (!BaseSpec)
2329     BaseSpec = const_cast<CXXBaseSpecifier *>(VirtualBaseSpec);
2330 
2331   // Initialize the base.
2332   bool InitList = true;
2333   Expr **Args = &Init;
2334   unsigned NumArgs = 1;
2335   if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
2336     InitList = false;
2337     Args = ParenList->getExprs();
2338     NumArgs = ParenList->getNumExprs();
2339   }
2340 
2341   InitializedEntity BaseEntity =
2342     InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
2343   InitializationKind Kind =
2344     InitList ? InitializationKind::CreateDirectList(BaseLoc)
2345              : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
2346                                                 InitRange.getEnd());
2347   InitializationSequence InitSeq(*this, BaseEntity, Kind, Args, NumArgs);
2348   ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind,
2349                                           MultiExprArg(*this, Args, NumArgs),
2350                                           0);
2351   if (BaseInit.isInvalid())
2352     return true;
2353 
2354   CheckImplicitConversions(BaseInit.get(), InitRange.getBegin());
2355 
2356   // C++0x [class.base.init]p7:
2357   //   The initialization of each base and member constitutes a
2358   //   full-expression.
2359   BaseInit = MaybeCreateExprWithCleanups(BaseInit);
2360   if (BaseInit.isInvalid())
2361     return true;
2362 
2363   // If we are in a dependent context, template instantiation will
2364   // perform this type-checking again. Just save the arguments that we
2365   // received in a ParenListExpr.
2366   // FIXME: This isn't quite ideal, since our ASTs don't capture all
2367   // of the information that we have about the base
2368   // initializer. However, deconstructing the ASTs is a dicey process,
2369   // and this approach is far more likely to get the corner cases right.
2370   if (CurContext->isDependentContext())
2371     BaseInit = Owned(Init);
2372 
2373   return new (Context) CXXCtorInitializer(Context, BaseTInfo,
2374                                           BaseSpec->isVirtual(),
2375                                           InitRange.getBegin(),
2376                                           BaseInit.takeAs<Expr>(),
2377                                           InitRange.getEnd(), EllipsisLoc);
2378 }
2379 
2380 // Create a static_cast\<T&&>(expr).
CastForMoving(Sema & SemaRef,Expr * E)2381 static Expr *CastForMoving(Sema &SemaRef, Expr *E) {
2382   QualType ExprType = E->getType();
2383   QualType TargetType = SemaRef.Context.getRValueReferenceType(ExprType);
2384   SourceLocation ExprLoc = E->getLocStart();
2385   TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
2386       TargetType, ExprLoc);
2387 
2388   return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
2389                                    SourceRange(ExprLoc, ExprLoc),
2390                                    E->getSourceRange()).take();
2391 }
2392 
2393 /// ImplicitInitializerKind - How an implicit base or member initializer should
2394 /// initialize its base or member.
2395 enum ImplicitInitializerKind {
2396   IIK_Default,
2397   IIK_Copy,
2398   IIK_Move
2399 };
2400 
2401 static bool
BuildImplicitBaseInitializer(Sema & SemaRef,CXXConstructorDecl * Constructor,ImplicitInitializerKind ImplicitInitKind,CXXBaseSpecifier * BaseSpec,bool IsInheritedVirtualBase,CXXCtorInitializer * & CXXBaseInit)2402 BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2403                              ImplicitInitializerKind ImplicitInitKind,
2404                              CXXBaseSpecifier *BaseSpec,
2405                              bool IsInheritedVirtualBase,
2406                              CXXCtorInitializer *&CXXBaseInit) {
2407   InitializedEntity InitEntity
2408     = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
2409                                         IsInheritedVirtualBase);
2410 
2411   ExprResult BaseInit;
2412 
2413   switch (ImplicitInitKind) {
2414   case IIK_Default: {
2415     InitializationKind InitKind
2416       = InitializationKind::CreateDefault(Constructor->getLocation());
2417     InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2418     BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2419                                MultiExprArg(SemaRef, 0, 0));
2420     break;
2421   }
2422 
2423   case IIK_Move:
2424   case IIK_Copy: {
2425     bool Moving = ImplicitInitKind == IIK_Move;
2426     ParmVarDecl *Param = Constructor->getParamDecl(0);
2427     QualType ParamType = Param->getType().getNonReferenceType();
2428 
2429     Expr *CopyCtorArg =
2430       DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2431                           SourceLocation(), Param, false,
2432                           Constructor->getLocation(), ParamType,
2433                           VK_LValue, 0);
2434 
2435     SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
2436 
2437     // Cast to the base class to avoid ambiguities.
2438     QualType ArgTy =
2439       SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
2440                                        ParamType.getQualifiers());
2441 
2442     if (Moving) {
2443       CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
2444     }
2445 
2446     CXXCastPath BasePath;
2447     BasePath.push_back(BaseSpec);
2448     CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
2449                                             CK_UncheckedDerivedToBase,
2450                                             Moving ? VK_XValue : VK_LValue,
2451                                             &BasePath).take();
2452 
2453     InitializationKind InitKind
2454       = InitializationKind::CreateDirect(Constructor->getLocation(),
2455                                          SourceLocation(), SourceLocation());
2456     InitializationSequence InitSeq(SemaRef, InitEntity, InitKind,
2457                                    &CopyCtorArg, 1);
2458     BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind,
2459                                MultiExprArg(&CopyCtorArg, 1));
2460     break;
2461   }
2462   }
2463 
2464   BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
2465   if (BaseInit.isInvalid())
2466     return true;
2467 
2468   CXXBaseInit =
2469     new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2470                SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
2471                                                         SourceLocation()),
2472                                              BaseSpec->isVirtual(),
2473                                              SourceLocation(),
2474                                              BaseInit.takeAs<Expr>(),
2475                                              SourceLocation(),
2476                                              SourceLocation());
2477 
2478   return false;
2479 }
2480 
RefersToRValueRef(Expr * MemRef)2481 static bool RefersToRValueRef(Expr *MemRef) {
2482   ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
2483   return Referenced->getType()->isRValueReferenceType();
2484 }
2485 
2486 static bool
BuildImplicitMemberInitializer(Sema & SemaRef,CXXConstructorDecl * Constructor,ImplicitInitializerKind ImplicitInitKind,FieldDecl * Field,IndirectFieldDecl * Indirect,CXXCtorInitializer * & CXXMemberInit)2487 BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
2488                                ImplicitInitializerKind ImplicitInitKind,
2489                                FieldDecl *Field, IndirectFieldDecl *Indirect,
2490                                CXXCtorInitializer *&CXXMemberInit) {
2491   if (Field->isInvalidDecl())
2492     return true;
2493 
2494   SourceLocation Loc = Constructor->getLocation();
2495 
2496   if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
2497     bool Moving = ImplicitInitKind == IIK_Move;
2498     ParmVarDecl *Param = Constructor->getParamDecl(0);
2499     QualType ParamType = Param->getType().getNonReferenceType();
2500 
2501     // Suppress copying zero-width bitfields.
2502     if (Field->isBitField() && Field->getBitWidthValue(SemaRef.Context) == 0)
2503       return false;
2504 
2505     Expr *MemberExprBase =
2506       DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
2507                           SourceLocation(), Param, false,
2508                           Loc, ParamType, VK_LValue, 0);
2509 
2510     SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
2511 
2512     if (Moving) {
2513       MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
2514     }
2515 
2516     // Build a reference to this field within the parameter.
2517     CXXScopeSpec SS;
2518     LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
2519                               Sema::LookupMemberName);
2520     MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
2521                                   : cast<ValueDecl>(Field), AS_public);
2522     MemberLookup.resolveKind();
2523     ExprResult CtorArg
2524       = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
2525                                          ParamType, Loc,
2526                                          /*IsArrow=*/false,
2527                                          SS,
2528                                          /*TemplateKWLoc=*/SourceLocation(),
2529                                          /*FirstQualifierInScope=*/0,
2530                                          MemberLookup,
2531                                          /*TemplateArgs=*/0);
2532     if (CtorArg.isInvalid())
2533       return true;
2534 
2535     // C++11 [class.copy]p15:
2536     //   - if a member m has rvalue reference type T&&, it is direct-initialized
2537     //     with static_cast<T&&>(x.m);
2538     if (RefersToRValueRef(CtorArg.get())) {
2539       CtorArg = CastForMoving(SemaRef, CtorArg.take());
2540     }
2541 
2542     // When the field we are copying is an array, create index variables for
2543     // each dimension of the array. We use these index variables to subscript
2544     // the source array, and other clients (e.g., CodeGen) will perform the
2545     // necessary iteration with these index variables.
2546     SmallVector<VarDecl *, 4> IndexVariables;
2547     QualType BaseType = Field->getType();
2548     QualType SizeType = SemaRef.Context.getSizeType();
2549     bool InitializingArray = false;
2550     while (const ConstantArrayType *Array
2551                           = SemaRef.Context.getAsConstantArrayType(BaseType)) {
2552       InitializingArray = true;
2553       // Create the iteration variable for this array index.
2554       IdentifierInfo *IterationVarName = 0;
2555       {
2556         SmallString<8> Str;
2557         llvm::raw_svector_ostream OS(Str);
2558         OS << "__i" << IndexVariables.size();
2559         IterationVarName = &SemaRef.Context.Idents.get(OS.str());
2560       }
2561       VarDecl *IterationVar
2562         = VarDecl::Create(SemaRef.Context, SemaRef.CurContext, Loc, Loc,
2563                           IterationVarName, SizeType,
2564                         SemaRef.Context.getTrivialTypeSourceInfo(SizeType, Loc),
2565                           SC_None, SC_None);
2566       IndexVariables.push_back(IterationVar);
2567 
2568       // Create a reference to the iteration variable.
2569       ExprResult IterationVarRef
2570         = SemaRef.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc);
2571       assert(!IterationVarRef.isInvalid() &&
2572              "Reference to invented variable cannot fail!");
2573       IterationVarRef = SemaRef.DefaultLvalueConversion(IterationVarRef.take());
2574       assert(!IterationVarRef.isInvalid() &&
2575              "Conversion of invented variable cannot fail!");
2576 
2577       // Subscript the array with this iteration variable.
2578       CtorArg = SemaRef.CreateBuiltinArraySubscriptExpr(CtorArg.take(), Loc,
2579                                                         IterationVarRef.take(),
2580                                                         Loc);
2581       if (CtorArg.isInvalid())
2582         return true;
2583 
2584       BaseType = Array->getElementType();
2585     }
2586 
2587     // The array subscript expression is an lvalue, which is wrong for moving.
2588     if (Moving && InitializingArray)
2589       CtorArg = CastForMoving(SemaRef, CtorArg.take());
2590 
2591     // Construct the entity that we will be initializing. For an array, this
2592     // will be first element in the array, which may require several levels
2593     // of array-subscript entities.
2594     SmallVector<InitializedEntity, 4> Entities;
2595     Entities.reserve(1 + IndexVariables.size());
2596     if (Indirect)
2597       Entities.push_back(InitializedEntity::InitializeMember(Indirect));
2598     else
2599       Entities.push_back(InitializedEntity::InitializeMember(Field));
2600     for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I)
2601       Entities.push_back(InitializedEntity::InitializeElement(SemaRef.Context,
2602                                                               0,
2603                                                               Entities.back()));
2604 
2605     // Direct-initialize to use the copy constructor.
2606     InitializationKind InitKind =
2607       InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
2608 
2609     Expr *CtorArgE = CtorArg.takeAs<Expr>();
2610     InitializationSequence InitSeq(SemaRef, Entities.back(), InitKind,
2611                                    &CtorArgE, 1);
2612 
2613     ExprResult MemberInit
2614       = InitSeq.Perform(SemaRef, Entities.back(), InitKind,
2615                         MultiExprArg(&CtorArgE, 1));
2616     MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2617     if (MemberInit.isInvalid())
2618       return true;
2619 
2620     if (Indirect) {
2621       assert(IndexVariables.size() == 0 &&
2622              "Indirect field improperly initialized");
2623       CXXMemberInit
2624         = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2625                                                    Loc, Loc,
2626                                                    MemberInit.takeAs<Expr>(),
2627                                                    Loc);
2628     } else
2629       CXXMemberInit = CXXCtorInitializer::Create(SemaRef.Context, Field, Loc,
2630                                                  Loc, MemberInit.takeAs<Expr>(),
2631                                                  Loc,
2632                                                  IndexVariables.data(),
2633                                                  IndexVariables.size());
2634     return false;
2635   }
2636 
2637   assert(ImplicitInitKind == IIK_Default && "Unhandled implicit init kind!");
2638 
2639   QualType FieldBaseElementType =
2640     SemaRef.Context.getBaseElementType(Field->getType());
2641 
2642   if (FieldBaseElementType->isRecordType()) {
2643     InitializedEntity InitEntity
2644       = Indirect? InitializedEntity::InitializeMember(Indirect)
2645                 : InitializedEntity::InitializeMember(Field);
2646     InitializationKind InitKind =
2647       InitializationKind::CreateDefault(Loc);
2648 
2649     InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, 0, 0);
2650     ExprResult MemberInit =
2651       InitSeq.Perform(SemaRef, InitEntity, InitKind, MultiExprArg());
2652 
2653     MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
2654     if (MemberInit.isInvalid())
2655       return true;
2656 
2657     if (Indirect)
2658       CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2659                                                                Indirect, Loc,
2660                                                                Loc,
2661                                                                MemberInit.get(),
2662                                                                Loc);
2663     else
2664       CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
2665                                                                Field, Loc, Loc,
2666                                                                MemberInit.get(),
2667                                                                Loc);
2668     return false;
2669   }
2670 
2671   if (!Field->getParent()->isUnion()) {
2672     if (FieldBaseElementType->isReferenceType()) {
2673       SemaRef.Diag(Constructor->getLocation(),
2674                    diag::err_uninitialized_member_in_ctor)
2675       << (int)Constructor->isImplicit()
2676       << SemaRef.Context.getTagDeclType(Constructor->getParent())
2677       << 0 << Field->getDeclName();
2678       SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2679       return true;
2680     }
2681 
2682     if (FieldBaseElementType.isConstQualified()) {
2683       SemaRef.Diag(Constructor->getLocation(),
2684                    diag::err_uninitialized_member_in_ctor)
2685       << (int)Constructor->isImplicit()
2686       << SemaRef.Context.getTagDeclType(Constructor->getParent())
2687       << 1 << Field->getDeclName();
2688       SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
2689       return true;
2690     }
2691   }
2692 
2693   if (SemaRef.getLangOpts().ObjCAutoRefCount &&
2694       FieldBaseElementType->isObjCRetainableType() &&
2695       FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_None &&
2696       FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) {
2697     // Instant objects:
2698     //   Default-initialize Objective-C pointers to NULL.
2699     CXXMemberInit
2700       = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2701                                                  Loc, Loc,
2702                  new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
2703                                                  Loc);
2704     return false;
2705   }
2706 
2707   // Nothing to initialize.
2708   CXXMemberInit = 0;
2709   return false;
2710 }
2711 
2712 namespace {
2713 struct BaseAndFieldInfo {
2714   Sema &S;
2715   CXXConstructorDecl *Ctor;
2716   bool AnyErrorsInInits;
2717   ImplicitInitializerKind IIK;
2718   llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
2719   SmallVector<CXXCtorInitializer*, 8> AllToInit;
2720 
BaseAndFieldInfo__anon01e4a4a60311::BaseAndFieldInfo2721   BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
2722     : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
2723     bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
2724     if (Generated && Ctor->isCopyConstructor())
2725       IIK = IIK_Copy;
2726     else if (Generated && Ctor->isMoveConstructor())
2727       IIK = IIK_Move;
2728     else
2729       IIK = IIK_Default;
2730   }
2731 
isImplicitCopyOrMove__anon01e4a4a60311::BaseAndFieldInfo2732   bool isImplicitCopyOrMove() const {
2733     switch (IIK) {
2734     case IIK_Copy:
2735     case IIK_Move:
2736       return true;
2737 
2738     case IIK_Default:
2739       return false;
2740     }
2741 
2742     llvm_unreachable("Invalid ImplicitInitializerKind!");
2743   }
2744 };
2745 }
2746 
2747 /// \brief Determine whether the given indirect field declaration is somewhere
2748 /// within an anonymous union.
isWithinAnonymousUnion(IndirectFieldDecl * F)2749 static bool isWithinAnonymousUnion(IndirectFieldDecl *F) {
2750   for (IndirectFieldDecl::chain_iterator C = F->chain_begin(),
2751                                       CEnd = F->chain_end();
2752        C != CEnd; ++C)
2753     if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>((*C)->getDeclContext()))
2754       if (Record->isUnion())
2755         return true;
2756 
2757   return false;
2758 }
2759 
2760 /// \brief Determine whether the given type is an incomplete or zero-lenfgth
2761 /// array type.
isIncompleteOrZeroLengthArrayType(ASTContext & Context,QualType T)2762 static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
2763   if (T->isIncompleteArrayType())
2764     return true;
2765 
2766   while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
2767     if (!ArrayT->getSize())
2768       return true;
2769 
2770     T = ArrayT->getElementType();
2771   }
2772 
2773   return false;
2774 }
2775 
CollectFieldInitializer(Sema & SemaRef,BaseAndFieldInfo & Info,FieldDecl * Field,IndirectFieldDecl * Indirect=0)2776 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
2777                                     FieldDecl *Field,
2778                                     IndirectFieldDecl *Indirect = 0) {
2779 
2780   // Overwhelmingly common case: we have a direct initializer for this field.
2781   if (CXXCtorInitializer *Init = Info.AllBaseFields.lookup(Field)) {
2782     Info.AllToInit.push_back(Init);
2783     return false;
2784   }
2785 
2786   // C++0x [class.base.init]p8: if the entity is a non-static data member that
2787   // has a brace-or-equal-initializer, the entity is initialized as specified
2788   // in [dcl.init].
2789   if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
2790     CXXCtorInitializer *Init;
2791     if (Indirect)
2792       Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect,
2793                                                       SourceLocation(),
2794                                                       SourceLocation(), 0,
2795                                                       SourceLocation());
2796     else
2797       Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
2798                                                       SourceLocation(),
2799                                                       SourceLocation(), 0,
2800                                                       SourceLocation());
2801     Info.AllToInit.push_back(Init);
2802     return false;
2803   }
2804 
2805   // Don't build an implicit initializer for union members if none was
2806   // explicitly specified.
2807   if (Field->getParent()->isUnion() ||
2808       (Indirect && isWithinAnonymousUnion(Indirect)))
2809     return false;
2810 
2811   // Don't initialize incomplete or zero-length arrays.
2812   if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
2813     return false;
2814 
2815   // Don't try to build an implicit initializer if there were semantic
2816   // errors in any of the initializers (and therefore we might be
2817   // missing some that the user actually wrote).
2818   if (Info.AnyErrorsInInits || Field->isInvalidDecl())
2819     return false;
2820 
2821   CXXCtorInitializer *Init = 0;
2822   if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
2823                                      Indirect, Init))
2824     return true;
2825 
2826   if (Init)
2827     Info.AllToInit.push_back(Init);
2828 
2829   return false;
2830 }
2831 
2832 bool
SetDelegatingInitializer(CXXConstructorDecl * Constructor,CXXCtorInitializer * Initializer)2833 Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
2834                                CXXCtorInitializer *Initializer) {
2835   assert(Initializer->isDelegatingInitializer());
2836   Constructor->setNumCtorInitializers(1);
2837   CXXCtorInitializer **initializer =
2838     new (Context) CXXCtorInitializer*[1];
2839   memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
2840   Constructor->setCtorInitializers(initializer);
2841 
2842   if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
2843     MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
2844     DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
2845   }
2846 
2847   DelegatingCtorDecls.push_back(Constructor);
2848 
2849   return false;
2850 }
2851 
SetCtorInitializers(CXXConstructorDecl * Constructor,CXXCtorInitializer ** Initializers,unsigned NumInitializers,bool AnyErrors)2852 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor,
2853                                CXXCtorInitializer **Initializers,
2854                                unsigned NumInitializers,
2855                                bool AnyErrors) {
2856   if (Constructor->isDependentContext()) {
2857     // Just store the initializers as written, they will be checked during
2858     // instantiation.
2859     if (NumInitializers > 0) {
2860       Constructor->setNumCtorInitializers(NumInitializers);
2861       CXXCtorInitializer **baseOrMemberInitializers =
2862         new (Context) CXXCtorInitializer*[NumInitializers];
2863       memcpy(baseOrMemberInitializers, Initializers,
2864              NumInitializers * sizeof(CXXCtorInitializer*));
2865       Constructor->setCtorInitializers(baseOrMemberInitializers);
2866     }
2867 
2868     return false;
2869   }
2870 
2871   BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
2872 
2873   // We need to build the initializer AST according to order of construction
2874   // and not what user specified in the Initializers list.
2875   CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
2876   if (!ClassDecl)
2877     return true;
2878 
2879   bool HadError = false;
2880 
2881   for (unsigned i = 0; i < NumInitializers; i++) {
2882     CXXCtorInitializer *Member = Initializers[i];
2883 
2884     if (Member->isBaseInitializer())
2885       Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
2886     else
2887       Info.AllBaseFields[Member->getAnyMember()] = Member;
2888   }
2889 
2890   // Keep track of the direct virtual bases.
2891   llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
2892   for (CXXRecordDecl::base_class_iterator I = ClassDecl->bases_begin(),
2893        E = ClassDecl->bases_end(); I != E; ++I) {
2894     if (I->isVirtual())
2895       DirectVBases.insert(I);
2896   }
2897 
2898   // Push virtual bases before others.
2899   for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
2900        E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
2901 
2902     if (CXXCtorInitializer *Value
2903         = Info.AllBaseFields.lookup(VBase->getType()->getAs<RecordType>())) {
2904       Info.AllToInit.push_back(Value);
2905     } else if (!AnyErrors) {
2906       bool IsInheritedVirtualBase = !DirectVBases.count(VBase);
2907       CXXCtorInitializer *CXXBaseInit;
2908       if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
2909                                        VBase, IsInheritedVirtualBase,
2910                                        CXXBaseInit)) {
2911         HadError = true;
2912         continue;
2913       }
2914 
2915       Info.AllToInit.push_back(CXXBaseInit);
2916     }
2917   }
2918 
2919   // Non-virtual bases.
2920   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
2921        E = ClassDecl->bases_end(); Base != E; ++Base) {
2922     // Virtuals are in the virtual base list and already constructed.
2923     if (Base->isVirtual())
2924       continue;
2925 
2926     if (CXXCtorInitializer *Value
2927           = Info.AllBaseFields.lookup(Base->getType()->getAs<RecordType>())) {
2928       Info.AllToInit.push_back(Value);
2929     } else if (!AnyErrors) {
2930       CXXCtorInitializer *CXXBaseInit;
2931       if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
2932                                        Base, /*IsInheritedVirtualBase=*/false,
2933                                        CXXBaseInit)) {
2934         HadError = true;
2935         continue;
2936       }
2937 
2938       Info.AllToInit.push_back(CXXBaseInit);
2939     }
2940   }
2941 
2942   // Fields.
2943   for (DeclContext::decl_iterator Mem = ClassDecl->decls_begin(),
2944                                MemEnd = ClassDecl->decls_end();
2945        Mem != MemEnd; ++Mem) {
2946     if (FieldDecl *F = dyn_cast<FieldDecl>(*Mem)) {
2947       // C++ [class.bit]p2:
2948       //   A declaration for a bit-field that omits the identifier declares an
2949       //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
2950       //   initialized.
2951       if (F->isUnnamedBitfield())
2952         continue;
2953 
2954       // If we're not generating the implicit copy/move constructor, then we'll
2955       // handle anonymous struct/union fields based on their individual
2956       // indirect fields.
2957       if (F->isAnonymousStructOrUnion() && Info.IIK == IIK_Default)
2958         continue;
2959 
2960       if (CollectFieldInitializer(*this, Info, F))
2961         HadError = true;
2962       continue;
2963     }
2964 
2965     // Beyond this point, we only consider default initialization.
2966     if (Info.IIK != IIK_Default)
2967       continue;
2968 
2969     if (IndirectFieldDecl *F = dyn_cast<IndirectFieldDecl>(*Mem)) {
2970       if (F->getType()->isIncompleteArrayType()) {
2971         assert(ClassDecl->hasFlexibleArrayMember() &&
2972                "Incomplete array type is not valid");
2973         continue;
2974       }
2975 
2976       // Initialize each field of an anonymous struct individually.
2977       if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
2978         HadError = true;
2979 
2980       continue;
2981     }
2982   }
2983 
2984   NumInitializers = Info.AllToInit.size();
2985   if (NumInitializers > 0) {
2986     Constructor->setNumCtorInitializers(NumInitializers);
2987     CXXCtorInitializer **baseOrMemberInitializers =
2988       new (Context) CXXCtorInitializer*[NumInitializers];
2989     memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
2990            NumInitializers * sizeof(CXXCtorInitializer*));
2991     Constructor->setCtorInitializers(baseOrMemberInitializers);
2992 
2993     // Constructors implicitly reference the base and member
2994     // destructors.
2995     MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
2996                                            Constructor->getParent());
2997   }
2998 
2999   return HadError;
3000 }
3001 
GetKeyForTopLevelField(FieldDecl * Field)3002 static void *GetKeyForTopLevelField(FieldDecl *Field) {
3003   // For anonymous unions, use the class declaration as the key.
3004   if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
3005     if (RT->getDecl()->isAnonymousStructOrUnion())
3006       return static_cast<void *>(RT->getDecl());
3007   }
3008   return static_cast<void *>(Field);
3009 }
3010 
GetKeyForBase(ASTContext & Context,QualType BaseType)3011 static void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
3012   return const_cast<Type*>(Context.getCanonicalType(BaseType).getTypePtr());
3013 }
3014 
GetKeyForMember(ASTContext & Context,CXXCtorInitializer * Member)3015 static void *GetKeyForMember(ASTContext &Context,
3016                              CXXCtorInitializer *Member) {
3017   if (!Member->isAnyMemberInitializer())
3018     return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
3019 
3020   // For fields injected into the class via declaration of an anonymous union,
3021   // use its anonymous union class declaration as the unique key.
3022   FieldDecl *Field = Member->getAnyMember();
3023 
3024   // If the field is a member of an anonymous struct or union, our key
3025   // is the anonymous record decl that's a direct child of the class.
3026   RecordDecl *RD = Field->getParent();
3027   if (RD->isAnonymousStructOrUnion()) {
3028     while (true) {
3029       RecordDecl *Parent = cast<RecordDecl>(RD->getDeclContext());
3030       if (Parent->isAnonymousStructOrUnion())
3031         RD = Parent;
3032       else
3033         break;
3034     }
3035 
3036     return static_cast<void *>(RD);
3037   }
3038 
3039   return static_cast<void *>(Field);
3040 }
3041 
3042 static void
DiagnoseBaseOrMemInitializerOrder(Sema & SemaRef,const CXXConstructorDecl * Constructor,CXXCtorInitializer ** Inits,unsigned NumInits)3043 DiagnoseBaseOrMemInitializerOrder(Sema &SemaRef,
3044                                   const CXXConstructorDecl *Constructor,
3045                                   CXXCtorInitializer **Inits,
3046                                   unsigned NumInits) {
3047   if (Constructor->getDeclContext()->isDependentContext())
3048     return;
3049 
3050   // Don't check initializers order unless the warning is enabled at the
3051   // location of at least one initializer.
3052   bool ShouldCheckOrder = false;
3053   for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3054     CXXCtorInitializer *Init = Inits[InitIndex];
3055     if (SemaRef.Diags.getDiagnosticLevel(diag::warn_initializer_out_of_order,
3056                                          Init->getSourceLocation())
3057           != DiagnosticsEngine::Ignored) {
3058       ShouldCheckOrder = true;
3059       break;
3060     }
3061   }
3062   if (!ShouldCheckOrder)
3063     return;
3064 
3065   // Build the list of bases and members in the order that they'll
3066   // actually be initialized.  The explicit initializers should be in
3067   // this same order but may be missing things.
3068   SmallVector<const void*, 32> IdealInitKeys;
3069 
3070   const CXXRecordDecl *ClassDecl = Constructor->getParent();
3071 
3072   // 1. Virtual bases.
3073   for (CXXRecordDecl::base_class_const_iterator VBase =
3074        ClassDecl->vbases_begin(),
3075        E = ClassDecl->vbases_end(); VBase != E; ++VBase)
3076     IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase->getType()));
3077 
3078   // 2. Non-virtual bases.
3079   for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(),
3080        E = ClassDecl->bases_end(); Base != E; ++Base) {
3081     if (Base->isVirtual())
3082       continue;
3083     IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base->getType()));
3084   }
3085 
3086   // 3. Direct fields.
3087   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
3088        E = ClassDecl->field_end(); Field != E; ++Field) {
3089     if (Field->isUnnamedBitfield())
3090       continue;
3091 
3092     IdealInitKeys.push_back(GetKeyForTopLevelField(*Field));
3093   }
3094 
3095   unsigned NumIdealInits = IdealInitKeys.size();
3096   unsigned IdealIndex = 0;
3097 
3098   CXXCtorInitializer *PrevInit = 0;
3099   for (unsigned InitIndex = 0; InitIndex != NumInits; ++InitIndex) {
3100     CXXCtorInitializer *Init = Inits[InitIndex];
3101     void *InitKey = GetKeyForMember(SemaRef.Context, Init);
3102 
3103     // Scan forward to try to find this initializer in the idealized
3104     // initializers list.
3105     for (; IdealIndex != NumIdealInits; ++IdealIndex)
3106       if (InitKey == IdealInitKeys[IdealIndex])
3107         break;
3108 
3109     // If we didn't find this initializer, it must be because we
3110     // scanned past it on a previous iteration.  That can only
3111     // happen if we're out of order;  emit a warning.
3112     if (IdealIndex == NumIdealInits && PrevInit) {
3113       Sema::SemaDiagnosticBuilder D =
3114         SemaRef.Diag(PrevInit->getSourceLocation(),
3115                      diag::warn_initializer_out_of_order);
3116 
3117       if (PrevInit->isAnyMemberInitializer())
3118         D << 0 << PrevInit->getAnyMember()->getDeclName();
3119       else
3120         D << 1 << PrevInit->getTypeSourceInfo()->getType();
3121 
3122       if (Init->isAnyMemberInitializer())
3123         D << 0 << Init->getAnyMember()->getDeclName();
3124       else
3125         D << 1 << Init->getTypeSourceInfo()->getType();
3126 
3127       // Move back to the initializer's location in the ideal list.
3128       for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
3129         if (InitKey == IdealInitKeys[IdealIndex])
3130           break;
3131 
3132       assert(IdealIndex != NumIdealInits &&
3133              "initializer not found in initializer list");
3134     }
3135 
3136     PrevInit = Init;
3137   }
3138 }
3139 
3140 namespace {
CheckRedundantInit(Sema & S,CXXCtorInitializer * Init,CXXCtorInitializer * & PrevInit)3141 bool CheckRedundantInit(Sema &S,
3142                         CXXCtorInitializer *Init,
3143                         CXXCtorInitializer *&PrevInit) {
3144   if (!PrevInit) {
3145     PrevInit = Init;
3146     return false;
3147   }
3148 
3149   if (FieldDecl *Field = Init->getMember())
3150     S.Diag(Init->getSourceLocation(),
3151            diag::err_multiple_mem_initialization)
3152       << Field->getDeclName()
3153       << Init->getSourceRange();
3154   else {
3155     const Type *BaseClass = Init->getBaseClass();
3156     assert(BaseClass && "neither field nor base");
3157     S.Diag(Init->getSourceLocation(),
3158            diag::err_multiple_base_initialization)
3159       << QualType(BaseClass, 0)
3160       << Init->getSourceRange();
3161   }
3162   S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
3163     << 0 << PrevInit->getSourceRange();
3164 
3165   return true;
3166 }
3167 
3168 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
3169 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
3170 
CheckRedundantUnionInit(Sema & S,CXXCtorInitializer * Init,RedundantUnionMap & Unions)3171 bool CheckRedundantUnionInit(Sema &S,
3172                              CXXCtorInitializer *Init,
3173                              RedundantUnionMap &Unions) {
3174   FieldDecl *Field = Init->getAnyMember();
3175   RecordDecl *Parent = Field->getParent();
3176   NamedDecl *Child = Field;
3177 
3178   while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
3179     if (Parent->isUnion()) {
3180       UnionEntry &En = Unions[Parent];
3181       if (En.first && En.first != Child) {
3182         S.Diag(Init->getSourceLocation(),
3183                diag::err_multiple_mem_union_initialization)
3184           << Field->getDeclName()
3185           << Init->getSourceRange();
3186         S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
3187           << 0 << En.second->getSourceRange();
3188         return true;
3189       }
3190       if (!En.first) {
3191         En.first = Child;
3192         En.second = Init;
3193       }
3194       if (!Parent->isAnonymousStructOrUnion())
3195         return false;
3196     }
3197 
3198     Child = Parent;
3199     Parent = cast<RecordDecl>(Parent->getDeclContext());
3200   }
3201 
3202   return false;
3203 }
3204 }
3205 
3206 /// ActOnMemInitializers - Handle the member initializers for a constructor.
ActOnMemInitializers(Decl * ConstructorDecl,SourceLocation ColonLoc,CXXCtorInitializer ** meminits,unsigned NumMemInits,bool AnyErrors)3207 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
3208                                 SourceLocation ColonLoc,
3209                                 CXXCtorInitializer **meminits,
3210                                 unsigned NumMemInits,
3211                                 bool AnyErrors) {
3212   if (!ConstructorDecl)
3213     return;
3214 
3215   AdjustDeclIfTemplate(ConstructorDecl);
3216 
3217   CXXConstructorDecl *Constructor
3218     = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
3219 
3220   if (!Constructor) {
3221     Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
3222     return;
3223   }
3224 
3225   CXXCtorInitializer **MemInits =
3226     reinterpret_cast<CXXCtorInitializer **>(meminits);
3227 
3228   // Mapping for the duplicate initializers check.
3229   // For member initializers, this is keyed with a FieldDecl*.
3230   // For base initializers, this is keyed with a Type*.
3231   llvm::DenseMap<void*, CXXCtorInitializer *> Members;
3232 
3233   // Mapping for the inconsistent anonymous-union initializers check.
3234   RedundantUnionMap MemberUnions;
3235 
3236   bool HadError = false;
3237   for (unsigned i = 0; i < NumMemInits; i++) {
3238     CXXCtorInitializer *Init = MemInits[i];
3239 
3240     // Set the source order index.
3241     Init->setSourceOrder(i);
3242 
3243     if (Init->isAnyMemberInitializer()) {
3244       FieldDecl *Field = Init->getAnyMember();
3245       if (CheckRedundantInit(*this, Init, Members[Field]) ||
3246           CheckRedundantUnionInit(*this, Init, MemberUnions))
3247         HadError = true;
3248     } else if (Init->isBaseInitializer()) {
3249       void *Key = GetKeyForBase(Context, QualType(Init->getBaseClass(), 0));
3250       if (CheckRedundantInit(*this, Init, Members[Key]))
3251         HadError = true;
3252     } else {
3253       assert(Init->isDelegatingInitializer());
3254       // This must be the only initializer
3255       if (i != 0 || NumMemInits > 1) {
3256         Diag(MemInits[0]->getSourceLocation(),
3257              diag::err_delegating_initializer_alone)
3258           << MemInits[0]->getSourceRange();
3259         HadError = true;
3260         // We will treat this as being the only initializer.
3261       }
3262       SetDelegatingInitializer(Constructor, MemInits[i]);
3263       // Return immediately as the initializer is set.
3264       return;
3265     }
3266   }
3267 
3268   if (HadError)
3269     return;
3270 
3271   DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits, NumMemInits);
3272 
3273   SetCtorInitializers(Constructor, MemInits, NumMemInits, AnyErrors);
3274 }
3275 
3276 void
MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,CXXRecordDecl * ClassDecl)3277 Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
3278                                              CXXRecordDecl *ClassDecl) {
3279   // Ignore dependent contexts. Also ignore unions, since their members never
3280   // have destructors implicitly called.
3281   if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
3282     return;
3283 
3284   // FIXME: all the access-control diagnostics are positioned on the
3285   // field/base declaration.  That's probably good; that said, the
3286   // user might reasonably want to know why the destructor is being
3287   // emitted, and we currently don't say.
3288 
3289   // Non-static data members.
3290   for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
3291        E = ClassDecl->field_end(); I != E; ++I) {
3292     FieldDecl *Field = *I;
3293     if (Field->isInvalidDecl())
3294       continue;
3295 
3296     // Don't destroy incomplete or zero-length arrays.
3297     if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
3298       continue;
3299 
3300     QualType FieldType = Context.getBaseElementType(Field->getType());
3301 
3302     const RecordType* RT = FieldType->getAs<RecordType>();
3303     if (!RT)
3304       continue;
3305 
3306     CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3307     if (FieldClassDecl->isInvalidDecl())
3308       continue;
3309     if (FieldClassDecl->hasIrrelevantDestructor())
3310       continue;
3311     // The destructor for an implicit anonymous union member is never invoked.
3312     if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
3313       continue;
3314 
3315     CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
3316     assert(Dtor && "No dtor found for FieldClassDecl!");
3317     CheckDestructorAccess(Field->getLocation(), Dtor,
3318                           PDiag(diag::err_access_dtor_field)
3319                             << Field->getDeclName()
3320                             << FieldType);
3321 
3322     MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3323     DiagnoseUseOfDecl(Dtor, Location);
3324   }
3325 
3326   llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
3327 
3328   // Bases.
3329   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
3330        E = ClassDecl->bases_end(); Base != E; ++Base) {
3331     // Bases are always records in a well-formed non-dependent class.
3332     const RecordType *RT = Base->getType()->getAs<RecordType>();
3333 
3334     // Remember direct virtual bases.
3335     if (Base->isVirtual())
3336       DirectVirtualBases.insert(RT);
3337 
3338     CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3339     // If our base class is invalid, we probably can't get its dtor anyway.
3340     if (BaseClassDecl->isInvalidDecl())
3341       continue;
3342     if (BaseClassDecl->hasIrrelevantDestructor())
3343       continue;
3344 
3345     CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3346     assert(Dtor && "No dtor found for BaseClassDecl!");
3347 
3348     // FIXME: caret should be on the start of the class name
3349     CheckDestructorAccess(Base->getLocStart(), Dtor,
3350                           PDiag(diag::err_access_dtor_base)
3351                             << Base->getType()
3352                             << Base->getSourceRange(),
3353                           Context.getTypeDeclType(ClassDecl));
3354 
3355     MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3356     DiagnoseUseOfDecl(Dtor, Location);
3357   }
3358 
3359   // Virtual bases.
3360   for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
3361        E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
3362 
3363     // Bases are always records in a well-formed non-dependent class.
3364     const RecordType *RT = VBase->getType()->castAs<RecordType>();
3365 
3366     // Ignore direct virtual bases.
3367     if (DirectVirtualBases.count(RT))
3368       continue;
3369 
3370     CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
3371     // If our base class is invalid, we probably can't get its dtor anyway.
3372     if (BaseClassDecl->isInvalidDecl())
3373       continue;
3374     if (BaseClassDecl->hasIrrelevantDestructor())
3375       continue;
3376 
3377     CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
3378     assert(Dtor && "No dtor found for BaseClassDecl!");
3379     CheckDestructorAccess(ClassDecl->getLocation(), Dtor,
3380                           PDiag(diag::err_access_dtor_vbase)
3381                             << VBase->getType(),
3382                           Context.getTypeDeclType(ClassDecl));
3383 
3384     MarkFunctionReferenced(Location, const_cast<CXXDestructorDecl*>(Dtor));
3385     DiagnoseUseOfDecl(Dtor, Location);
3386   }
3387 }
3388 
ActOnDefaultCtorInitializers(Decl * CDtorDecl)3389 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
3390   if (!CDtorDecl)
3391     return;
3392 
3393   if (CXXConstructorDecl *Constructor
3394       = dyn_cast<CXXConstructorDecl>(CDtorDecl))
3395     SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false);
3396 }
3397 
RequireNonAbstractType(SourceLocation Loc,QualType T,unsigned DiagID,AbstractDiagSelID SelID)3398 bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3399                                   unsigned DiagID, AbstractDiagSelID SelID) {
3400   if (SelID == -1)
3401     return RequireNonAbstractType(Loc, T, PDiag(DiagID));
3402   else
3403     return RequireNonAbstractType(Loc, T, PDiag(DiagID) << SelID);
3404 }
3405 
RequireNonAbstractType(SourceLocation Loc,QualType T,const PartialDiagnostic & PD)3406 bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
3407                                   const PartialDiagnostic &PD) {
3408   if (!getLangOpts().CPlusPlus)
3409     return false;
3410 
3411   if (const ArrayType *AT = Context.getAsArrayType(T))
3412     return RequireNonAbstractType(Loc, AT->getElementType(), PD);
3413 
3414   if (const PointerType *PT = T->getAs<PointerType>()) {
3415     // Find the innermost pointer type.
3416     while (const PointerType *T = PT->getPointeeType()->getAs<PointerType>())
3417       PT = T;
3418 
3419     if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
3420       return RequireNonAbstractType(Loc, AT->getElementType(), PD);
3421   }
3422 
3423   const RecordType *RT = T->getAs<RecordType>();
3424   if (!RT)
3425     return false;
3426 
3427   const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
3428 
3429   // We can't answer whether something is abstract until it has a
3430   // definition.  If it's currently being defined, we'll walk back
3431   // over all the declarations when we have a full definition.
3432   const CXXRecordDecl *Def = RD->getDefinition();
3433   if (!Def || Def->isBeingDefined())
3434     return false;
3435 
3436   if (!RD->isAbstract())
3437     return false;
3438 
3439   Diag(Loc, PD) << RD->getDeclName();
3440   DiagnoseAbstractType(RD);
3441 
3442   return true;
3443 }
3444 
DiagnoseAbstractType(const CXXRecordDecl * RD)3445 void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
3446   // Check if we've already emitted the list of pure virtual functions
3447   // for this class.
3448   if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
3449     return;
3450 
3451   CXXFinalOverriderMap FinalOverriders;
3452   RD->getFinalOverriders(FinalOverriders);
3453 
3454   // Keep a set of seen pure methods so we won't diagnose the same method
3455   // more than once.
3456   llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
3457 
3458   for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
3459                                    MEnd = FinalOverriders.end();
3460        M != MEnd;
3461        ++M) {
3462     for (OverridingMethods::iterator SO = M->second.begin(),
3463                                   SOEnd = M->second.end();
3464          SO != SOEnd; ++SO) {
3465       // C++ [class.abstract]p4:
3466       //   A class is abstract if it contains or inherits at least one
3467       //   pure virtual function for which the final overrider is pure
3468       //   virtual.
3469 
3470       //
3471       if (SO->second.size() != 1)
3472         continue;
3473 
3474       if (!SO->second.front().Method->isPure())
3475         continue;
3476 
3477       if (!SeenPureMethods.insert(SO->second.front().Method))
3478         continue;
3479 
3480       Diag(SO->second.front().Method->getLocation(),
3481            diag::note_pure_virtual_function)
3482         << SO->second.front().Method->getDeclName() << RD->getDeclName();
3483     }
3484   }
3485 
3486   if (!PureVirtualClassDiagSet)
3487     PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
3488   PureVirtualClassDiagSet->insert(RD);
3489 }
3490 
3491 namespace {
3492 struct AbstractUsageInfo {
3493   Sema &S;
3494   CXXRecordDecl *Record;
3495   CanQualType AbstractType;
3496   bool Invalid;
3497 
AbstractUsageInfo__anon01e4a4a60511::AbstractUsageInfo3498   AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
3499     : S(S), Record(Record),
3500       AbstractType(S.Context.getCanonicalType(
3501                    S.Context.getTypeDeclType(Record))),
3502       Invalid(false) {}
3503 
DiagnoseAbstractType__anon01e4a4a60511::AbstractUsageInfo3504   void DiagnoseAbstractType() {
3505     if (Invalid) return;
3506     S.DiagnoseAbstractType(Record);
3507     Invalid = true;
3508   }
3509 
3510   void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
3511 };
3512 
3513 struct CheckAbstractUsage {
3514   AbstractUsageInfo &Info;
3515   const NamedDecl *Ctx;
3516 
CheckAbstractUsage__anon01e4a4a60511::CheckAbstractUsage3517   CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
3518     : Info(Info), Ctx(Ctx) {}
3519 
Visit__anon01e4a4a60511::CheckAbstractUsage3520   void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3521     switch (TL.getTypeLocClass()) {
3522 #define ABSTRACT_TYPELOC(CLASS, PARENT)
3523 #define TYPELOC(CLASS, PARENT) \
3524     case TypeLoc::CLASS: Check(cast<CLASS##TypeLoc>(TL), Sel); break;
3525 #include "clang/AST/TypeLocNodes.def"
3526     }
3527   }
3528 
Check__anon01e4a4a60511::CheckAbstractUsage3529   void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3530     Visit(TL.getResultLoc(), Sema::AbstractReturnType);
3531     for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3532       if (!TL.getArg(I))
3533         continue;
3534 
3535       TypeSourceInfo *TSI = TL.getArg(I)->getTypeSourceInfo();
3536       if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
3537     }
3538   }
3539 
Check__anon01e4a4a60511::CheckAbstractUsage3540   void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3541     Visit(TL.getElementLoc(), Sema::AbstractArrayType);
3542   }
3543 
Check__anon01e4a4a60511::CheckAbstractUsage3544   void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
3545     // Visit the type parameters from a permissive context.
3546     for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
3547       TemplateArgumentLoc TAL = TL.getArgLoc(I);
3548       if (TAL.getArgument().getKind() == TemplateArgument::Type)
3549         if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
3550           Visit(TSI->getTypeLoc(), Sema::AbstractNone);
3551       // TODO: other template argument types?
3552     }
3553   }
3554 
3555   // Visit pointee types from a permissive context.
3556 #define CheckPolymorphic(Type) \
3557   void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
3558     Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
3559   }
3560   CheckPolymorphic(PointerTypeLoc)
CheckPolymorphic__anon01e4a4a60511::CheckAbstractUsage3561   CheckPolymorphic(ReferenceTypeLoc)
3562   CheckPolymorphic(MemberPointerTypeLoc)
3563   CheckPolymorphic(BlockPointerTypeLoc)
3564   CheckPolymorphic(AtomicTypeLoc)
3565 
3566   /// Handle all the types we haven't given a more specific
3567   /// implementation for above.
3568   void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
3569     // Every other kind of type that we haven't called out already
3570     // that has an inner type is either (1) sugar or (2) contains that
3571     // inner type in some way as a subobject.
3572     if (TypeLoc Next = TL.getNextTypeLoc())
3573       return Visit(Next, Sel);
3574 
3575     // If there's no inner type and we're in a permissive context,
3576     // don't diagnose.
3577     if (Sel == Sema::AbstractNone) return;
3578 
3579     // Check whether the type matches the abstract type.
3580     QualType T = TL.getType();
3581     if (T->isArrayType()) {
3582       Sel = Sema::AbstractArrayType;
3583       T = Info.S.Context.getBaseElementType(T);
3584     }
3585     CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
3586     if (CT != Info.AbstractType) return;
3587 
3588     // It matched; do some magic.
3589     if (Sel == Sema::AbstractArrayType) {
3590       Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
3591         << T << TL.getSourceRange();
3592     } else {
3593       Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
3594         << Sel << T << TL.getSourceRange();
3595     }
3596     Info.DiagnoseAbstractType();
3597   }
3598 };
3599 
CheckType(const NamedDecl * D,TypeLoc TL,Sema::AbstractDiagSelID Sel)3600 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
3601                                   Sema::AbstractDiagSelID Sel) {
3602   CheckAbstractUsage(*this, D).Visit(TL, Sel);
3603 }
3604 
3605 }
3606 
3607 /// Check for invalid uses of an abstract type in a method declaration.
CheckAbstractClassUsage(AbstractUsageInfo & Info,CXXMethodDecl * MD)3608 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3609                                     CXXMethodDecl *MD) {
3610   // No need to do the check on definitions, which require that
3611   // the return/param types be complete.
3612   if (MD->doesThisDeclarationHaveABody())
3613     return;
3614 
3615   // For safety's sake, just ignore it if we don't have type source
3616   // information.  This should never happen for non-implicit methods,
3617   // but...
3618   if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
3619     Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
3620 }
3621 
3622 /// Check for invalid uses of an abstract type within a class definition.
CheckAbstractClassUsage(AbstractUsageInfo & Info,CXXRecordDecl * RD)3623 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
3624                                     CXXRecordDecl *RD) {
3625   for (CXXRecordDecl::decl_iterator
3626          I = RD->decls_begin(), E = RD->decls_end(); I != E; ++I) {
3627     Decl *D = *I;
3628     if (D->isImplicit()) continue;
3629 
3630     // Methods and method templates.
3631     if (isa<CXXMethodDecl>(D)) {
3632       CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
3633     } else if (isa<FunctionTemplateDecl>(D)) {
3634       FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
3635       CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
3636 
3637     // Fields and static variables.
3638     } else if (isa<FieldDecl>(D)) {
3639       FieldDecl *FD = cast<FieldDecl>(D);
3640       if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
3641         Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
3642     } else if (isa<VarDecl>(D)) {
3643       VarDecl *VD = cast<VarDecl>(D);
3644       if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
3645         Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
3646 
3647     // Nested classes and class templates.
3648     } else if (isa<CXXRecordDecl>(D)) {
3649       CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
3650     } else if (isa<ClassTemplateDecl>(D)) {
3651       CheckAbstractClassUsage(Info,
3652                              cast<ClassTemplateDecl>(D)->getTemplatedDecl());
3653     }
3654   }
3655 }
3656 
3657 /// \brief Perform semantic checks on a class definition that has been
3658 /// completing, introducing implicitly-declared members, checking for
3659 /// abstract types, etc.
CheckCompletedCXXClass(CXXRecordDecl * Record)3660 void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
3661   if (!Record)
3662     return;
3663 
3664   if (Record->isAbstract() && !Record->isInvalidDecl()) {
3665     AbstractUsageInfo Info(*this, Record);
3666     CheckAbstractClassUsage(Info, Record);
3667   }
3668 
3669   // If this is not an aggregate type and has no user-declared constructor,
3670   // complain about any non-static data members of reference or const scalar
3671   // type, since they will never get initializers.
3672   if (!Record->isInvalidDecl() && !Record->isDependentType() &&
3673       !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
3674       !Record->isLambda()) {
3675     bool Complained = false;
3676     for (RecordDecl::field_iterator F = Record->field_begin(),
3677                                  FEnd = Record->field_end();
3678          F != FEnd; ++F) {
3679       if (F->hasInClassInitializer() || F->isUnnamedBitfield())
3680         continue;
3681 
3682       if (F->getType()->isReferenceType() ||
3683           (F->getType().isConstQualified() && F->getType()->isScalarType())) {
3684         if (!Complained) {
3685           Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
3686             << Record->getTagKind() << Record;
3687           Complained = true;
3688         }
3689 
3690         Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
3691           << F->getType()->isReferenceType()
3692           << F->getDeclName();
3693       }
3694     }
3695   }
3696 
3697   if (Record->isDynamicClass() && !Record->isDependentType())
3698     DynamicClasses.push_back(Record);
3699 
3700   if (Record->getIdentifier()) {
3701     // C++ [class.mem]p13:
3702     //   If T is the name of a class, then each of the following shall have a
3703     //   name different from T:
3704     //     - every member of every anonymous union that is a member of class T.
3705     //
3706     // C++ [class.mem]p14:
3707     //   In addition, if class T has a user-declared constructor (12.1), every
3708     //   non-static data member of class T shall have a name different from T.
3709     for (DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
3710          R.first != R.second; ++R.first) {
3711       NamedDecl *D = *R.first;
3712       if ((isa<FieldDecl>(D) && Record->hasUserDeclaredConstructor()) ||
3713           isa<IndirectFieldDecl>(D)) {
3714         Diag(D->getLocation(), diag::err_member_name_of_class)
3715           << D->getDeclName();
3716         break;
3717       }
3718     }
3719   }
3720 
3721   // Warn if the class has virtual methods but non-virtual public destructor.
3722   if (Record->isPolymorphic() && !Record->isDependentType()) {
3723     CXXDestructorDecl *dtor = Record->getDestructor();
3724     if (!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public))
3725       Diag(dtor ? dtor->getLocation() : Record->getLocation(),
3726            diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
3727   }
3728 
3729   // See if a method overloads virtual methods in a base
3730   /// class without overriding any.
3731   if (!Record->isDependentType()) {
3732     for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3733                                      MEnd = Record->method_end();
3734          M != MEnd; ++M) {
3735       if (!(*M)->isStatic())
3736         DiagnoseHiddenVirtualMethods(Record, *M);
3737     }
3738   }
3739 
3740   // C++0x [dcl.constexpr]p8: A constexpr specifier for a non-static member
3741   // function that is not a constructor declares that member function to be
3742   // const. [...] The class of which that function is a member shall be
3743   // a literal type.
3744   //
3745   // If the class has virtual bases, any constexpr members will already have
3746   // been diagnosed by the checks performed on the member declaration, so
3747   // suppress this (less useful) diagnostic.
3748   if (LangOpts.CPlusPlus0x && !Record->isDependentType() &&
3749       !Record->isLiteral() && !Record->getNumVBases()) {
3750     for (CXXRecordDecl::method_iterator M = Record->method_begin(),
3751                                      MEnd = Record->method_end();
3752          M != MEnd; ++M) {
3753       if (M->isConstexpr() && M->isInstance() && !isa<CXXConstructorDecl>(*M)) {
3754         switch (Record->getTemplateSpecializationKind()) {
3755         case TSK_ImplicitInstantiation:
3756         case TSK_ExplicitInstantiationDeclaration:
3757         case TSK_ExplicitInstantiationDefinition:
3758           // If a template instantiates to a non-literal type, but its members
3759           // instantiate to constexpr functions, the template is technically
3760           // ill-formed, but we allow it for sanity.
3761           continue;
3762 
3763         case TSK_Undeclared:
3764         case TSK_ExplicitSpecialization:
3765           RequireLiteralType((*M)->getLocation(), Context.getRecordType(Record),
3766                              PDiag(diag::err_constexpr_method_non_literal));
3767           break;
3768         }
3769 
3770         // Only produce one error per class.
3771         break;
3772       }
3773     }
3774   }
3775 
3776   // Declare inherited constructors. We do this eagerly here because:
3777   // - The standard requires an eager diagnostic for conflicting inherited
3778   //   constructors from different classes.
3779   // - The lazy declaration of the other implicit constructors is so as to not
3780   //   waste space and performance on classes that are not meant to be
3781   //   instantiated (e.g. meta-functions). This doesn't apply to classes that
3782   //   have inherited constructors.
3783   DeclareInheritedConstructors(Record);
3784 
3785   if (!Record->isDependentType())
3786     CheckExplicitlyDefaultedMethods(Record);
3787 }
3788 
CheckExplicitlyDefaultedMethods(CXXRecordDecl * Record)3789 void Sema::CheckExplicitlyDefaultedMethods(CXXRecordDecl *Record) {
3790   for (CXXRecordDecl::method_iterator MI = Record->method_begin(),
3791                                       ME = Record->method_end();
3792        MI != ME; ++MI) {
3793     if (!MI->isInvalidDecl() && MI->isExplicitlyDefaulted()) {
3794       switch (getSpecialMember(*MI)) {
3795       case CXXDefaultConstructor:
3796         CheckExplicitlyDefaultedDefaultConstructor(
3797                                                   cast<CXXConstructorDecl>(*MI));
3798         break;
3799 
3800       case CXXDestructor:
3801         CheckExplicitlyDefaultedDestructor(cast<CXXDestructorDecl>(*MI));
3802         break;
3803 
3804       case CXXCopyConstructor:
3805         CheckExplicitlyDefaultedCopyConstructor(cast<CXXConstructorDecl>(*MI));
3806         break;
3807 
3808       case CXXCopyAssignment:
3809         CheckExplicitlyDefaultedCopyAssignment(*MI);
3810         break;
3811 
3812       case CXXMoveConstructor:
3813         CheckExplicitlyDefaultedMoveConstructor(cast<CXXConstructorDecl>(*MI));
3814         break;
3815 
3816       case CXXMoveAssignment:
3817         CheckExplicitlyDefaultedMoveAssignment(*MI);
3818         break;
3819 
3820       case CXXInvalid:
3821         llvm_unreachable("non-special member explicitly defaulted!");
3822       }
3823     }
3824   }
3825 
3826 }
3827 
CheckExplicitlyDefaultedDefaultConstructor(CXXConstructorDecl * CD)3828 void Sema::CheckExplicitlyDefaultedDefaultConstructor(CXXConstructorDecl *CD) {
3829   assert(CD->isExplicitlyDefaulted() && CD->isDefaultConstructor());
3830 
3831   // Whether this was the first-declared instance of the constructor.
3832   // This affects whether we implicitly add an exception spec (and, eventually,
3833   // constexpr). It is also ill-formed to explicitly default a constructor such
3834   // that it would be deleted. (C++0x [decl.fct.def.default])
3835   bool First = CD == CD->getCanonicalDecl();
3836 
3837   bool HadError = false;
3838   if (CD->getNumParams() != 0) {
3839     Diag(CD->getLocation(), diag::err_defaulted_default_ctor_params)
3840       << CD->getSourceRange();
3841     HadError = true;
3842   }
3843 
3844   ImplicitExceptionSpecification Spec
3845     = ComputeDefaultedDefaultCtorExceptionSpec(CD->getParent());
3846   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
3847   if (EPI.ExceptionSpecType == EST_Delayed) {
3848     // Exception specification depends on some deferred part of the class. We'll
3849     // try again when the class's definition has been fully processed.
3850     return;
3851   }
3852   const FunctionProtoType *CtorType = CD->getType()->getAs<FunctionProtoType>(),
3853                           *ExceptionType = Context.getFunctionType(
3854                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
3855 
3856   // C++11 [dcl.fct.def.default]p2:
3857   //   An explicitly-defaulted function may be declared constexpr only if it
3858   //   would have been implicitly declared as constexpr,
3859   // Do not apply this rule to templates, since core issue 1358 makes such
3860   // functions always instantiate to constexpr functions.
3861   if (CD->isConstexpr() &&
3862       CD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
3863     if (!CD->getParent()->defaultedDefaultConstructorIsConstexpr()) {
3864       Diag(CD->getLocStart(), diag::err_incorrect_defaulted_constexpr)
3865         << CXXDefaultConstructor;
3866       HadError = true;
3867     }
3868   }
3869   //   and may have an explicit exception-specification only if it is compatible
3870   //   with the exception-specification on the implicit declaration.
3871   if (CtorType->hasExceptionSpec()) {
3872     if (CheckEquivalentExceptionSpec(
3873           PDiag(diag::err_incorrect_defaulted_exception_spec)
3874             << CXXDefaultConstructor,
3875           PDiag(),
3876           ExceptionType, SourceLocation(),
3877           CtorType, CD->getLocation())) {
3878       HadError = true;
3879     }
3880   }
3881 
3882   //   If a function is explicitly defaulted on its first declaration,
3883   if (First) {
3884     //  -- it is implicitly considered to be constexpr if the implicit
3885     //     definition would be,
3886     CD->setConstexpr(CD->getParent()->defaultedDefaultConstructorIsConstexpr());
3887 
3888     //  -- it is implicitly considered to have the same
3889     //     exception-specification as if it had been implicitly declared
3890     //
3891     // FIXME: a compatible, but different, explicit exception specification
3892     // will be silently overridden. We should issue a warning if this happens.
3893     EPI.ExtInfo = CtorType->getExtInfo();
3894 
3895     // Such a function is also trivial if the implicitly-declared function
3896     // would have been.
3897     CD->setTrivial(CD->getParent()->hasTrivialDefaultConstructor());
3898   }
3899 
3900   if (HadError) {
3901     CD->setInvalidDecl();
3902     return;
3903   }
3904 
3905   if (ShouldDeleteSpecialMember(CD, CXXDefaultConstructor)) {
3906     if (First) {
3907       CD->setDeletedAsWritten();
3908     } else {
3909       Diag(CD->getLocation(), diag::err_out_of_line_default_deletes)
3910         << CXXDefaultConstructor;
3911       CD->setInvalidDecl();
3912     }
3913   }
3914 }
3915 
CheckExplicitlyDefaultedCopyConstructor(CXXConstructorDecl * CD)3916 void Sema::CheckExplicitlyDefaultedCopyConstructor(CXXConstructorDecl *CD) {
3917   assert(CD->isExplicitlyDefaulted() && CD->isCopyConstructor());
3918 
3919   // Whether this was the first-declared instance of the constructor.
3920   bool First = CD == CD->getCanonicalDecl();
3921 
3922   bool HadError = false;
3923   if (CD->getNumParams() != 1) {
3924     Diag(CD->getLocation(), diag::err_defaulted_copy_ctor_params)
3925       << CD->getSourceRange();
3926     HadError = true;
3927   }
3928 
3929   ImplicitExceptionSpecification Spec(*this);
3930   bool Const;
3931   llvm::tie(Spec, Const) =
3932     ComputeDefaultedCopyCtorExceptionSpecAndConst(CD->getParent());
3933 
3934   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
3935   const FunctionProtoType *CtorType = CD->getType()->getAs<FunctionProtoType>(),
3936                           *ExceptionType = Context.getFunctionType(
3937                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
3938 
3939   // Check for parameter type matching.
3940   // This is a copy ctor so we know it's a cv-qualified reference to T.
3941   QualType ArgType = CtorType->getArgType(0);
3942   if (ArgType->getPointeeType().isVolatileQualified()) {
3943     Diag(CD->getLocation(), diag::err_defaulted_copy_ctor_volatile_param);
3944     HadError = true;
3945   }
3946   if (ArgType->getPointeeType().isConstQualified() && !Const) {
3947     Diag(CD->getLocation(), diag::err_defaulted_copy_ctor_const_param);
3948     HadError = true;
3949   }
3950 
3951   // C++11 [dcl.fct.def.default]p2:
3952   //   An explicitly-defaulted function may be declared constexpr only if it
3953   //   would have been implicitly declared as constexpr,
3954   // Do not apply this rule to templates, since core issue 1358 makes such
3955   // functions always instantiate to constexpr functions.
3956   if (CD->isConstexpr() &&
3957       CD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
3958     if (!CD->getParent()->defaultedCopyConstructorIsConstexpr()) {
3959       Diag(CD->getLocStart(), diag::err_incorrect_defaulted_constexpr)
3960         << CXXCopyConstructor;
3961       HadError = true;
3962     }
3963   }
3964   //   and may have an explicit exception-specification only if it is compatible
3965   //   with the exception-specification on the implicit declaration.
3966   if (CtorType->hasExceptionSpec()) {
3967     if (CheckEquivalentExceptionSpec(
3968           PDiag(diag::err_incorrect_defaulted_exception_spec)
3969             << CXXCopyConstructor,
3970           PDiag(),
3971           ExceptionType, SourceLocation(),
3972           CtorType, CD->getLocation())) {
3973       HadError = true;
3974     }
3975   }
3976 
3977   //   If a function is explicitly defaulted on its first declaration,
3978   if (First) {
3979     //  -- it is implicitly considered to be constexpr if the implicit
3980     //     definition would be,
3981     CD->setConstexpr(CD->getParent()->defaultedCopyConstructorIsConstexpr());
3982 
3983     //  -- it is implicitly considered to have the same
3984     //     exception-specification as if it had been implicitly declared, and
3985     //
3986     // FIXME: a compatible, but different, explicit exception specification
3987     // will be silently overridden. We should issue a warning if this happens.
3988     EPI.ExtInfo = CtorType->getExtInfo();
3989 
3990     //  -- [...] it shall have the same parameter type as if it had been
3991     //     implicitly declared.
3992     CD->setType(Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI));
3993 
3994     // Such a function is also trivial if the implicitly-declared function
3995     // would have been.
3996     CD->setTrivial(CD->getParent()->hasTrivialCopyConstructor());
3997   }
3998 
3999   if (HadError) {
4000     CD->setInvalidDecl();
4001     return;
4002   }
4003 
4004   if (ShouldDeleteSpecialMember(CD, CXXCopyConstructor)) {
4005     if (First) {
4006       CD->setDeletedAsWritten();
4007     } else {
4008       Diag(CD->getLocation(), diag::err_out_of_line_default_deletes)
4009         << CXXCopyConstructor;
4010       CD->setInvalidDecl();
4011     }
4012   }
4013 }
4014 
CheckExplicitlyDefaultedCopyAssignment(CXXMethodDecl * MD)4015 void Sema::CheckExplicitlyDefaultedCopyAssignment(CXXMethodDecl *MD) {
4016   assert(MD->isExplicitlyDefaulted());
4017 
4018   // Whether this was the first-declared instance of the operator
4019   bool First = MD == MD->getCanonicalDecl();
4020 
4021   bool HadError = false;
4022   if (MD->getNumParams() != 1) {
4023     Diag(MD->getLocation(), diag::err_defaulted_copy_assign_params)
4024       << MD->getSourceRange();
4025     HadError = true;
4026   }
4027 
4028   QualType ReturnType =
4029     MD->getType()->getAs<FunctionType>()->getResultType();
4030   if (!ReturnType->isLValueReferenceType() ||
4031       !Context.hasSameType(
4032         Context.getCanonicalType(ReturnType->getPointeeType()),
4033         Context.getCanonicalType(Context.getTypeDeclType(MD->getParent())))) {
4034     Diag(MD->getLocation(), diag::err_defaulted_copy_assign_return_type);
4035     HadError = true;
4036   }
4037 
4038   ImplicitExceptionSpecification Spec(*this);
4039   bool Const;
4040   llvm::tie(Spec, Const) =
4041     ComputeDefaultedCopyCtorExceptionSpecAndConst(MD->getParent());
4042 
4043   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
4044   const FunctionProtoType *OperType = MD->getType()->getAs<FunctionProtoType>(),
4045                           *ExceptionType = Context.getFunctionType(
4046                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
4047 
4048   QualType ArgType = OperType->getArgType(0);
4049   if (!ArgType->isLValueReferenceType()) {
4050     Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
4051     HadError = true;
4052   } else {
4053     if (ArgType->getPointeeType().isVolatileQualified()) {
4054       Diag(MD->getLocation(), diag::err_defaulted_copy_assign_volatile_param);
4055       HadError = true;
4056     }
4057     if (ArgType->getPointeeType().isConstQualified() && !Const) {
4058       Diag(MD->getLocation(), diag::err_defaulted_copy_assign_const_param);
4059       HadError = true;
4060     }
4061   }
4062 
4063   if (OperType->getTypeQuals()) {
4064     Diag(MD->getLocation(), diag::err_defaulted_copy_assign_quals);
4065     HadError = true;
4066   }
4067 
4068   if (OperType->hasExceptionSpec()) {
4069     if (CheckEquivalentExceptionSpec(
4070           PDiag(diag::err_incorrect_defaulted_exception_spec)
4071             << CXXCopyAssignment,
4072           PDiag(),
4073           ExceptionType, SourceLocation(),
4074           OperType, MD->getLocation())) {
4075       HadError = true;
4076     }
4077   }
4078   if (First) {
4079     // We set the declaration to have the computed exception spec here.
4080     // We duplicate the one parameter type.
4081     EPI.RefQualifier = OperType->getRefQualifier();
4082     EPI.ExtInfo = OperType->getExtInfo();
4083     MD->setType(Context.getFunctionType(ReturnType, &ArgType, 1, EPI));
4084 
4085     // Such a function is also trivial if the implicitly-declared function
4086     // would have been.
4087     MD->setTrivial(MD->getParent()->hasTrivialCopyAssignment());
4088   }
4089 
4090   if (HadError) {
4091     MD->setInvalidDecl();
4092     return;
4093   }
4094 
4095   if (ShouldDeleteSpecialMember(MD, CXXCopyAssignment)) {
4096     if (First) {
4097       MD->setDeletedAsWritten();
4098     } else {
4099       Diag(MD->getLocation(), diag::err_out_of_line_default_deletes)
4100         << CXXCopyAssignment;
4101       MD->setInvalidDecl();
4102     }
4103   }
4104 }
4105 
CheckExplicitlyDefaultedMoveConstructor(CXXConstructorDecl * CD)4106 void Sema::CheckExplicitlyDefaultedMoveConstructor(CXXConstructorDecl *CD) {
4107   assert(CD->isExplicitlyDefaulted() && CD->isMoveConstructor());
4108 
4109   // Whether this was the first-declared instance of the constructor.
4110   bool First = CD == CD->getCanonicalDecl();
4111 
4112   bool HadError = false;
4113   if (CD->getNumParams() != 1) {
4114     Diag(CD->getLocation(), diag::err_defaulted_move_ctor_params)
4115       << CD->getSourceRange();
4116     HadError = true;
4117   }
4118 
4119   ImplicitExceptionSpecification Spec(
4120       ComputeDefaultedMoveCtorExceptionSpec(CD->getParent()));
4121 
4122   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
4123   const FunctionProtoType *CtorType = CD->getType()->getAs<FunctionProtoType>(),
4124                           *ExceptionType = Context.getFunctionType(
4125                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
4126 
4127   // Check for parameter type matching.
4128   // This is a move ctor so we know it's a cv-qualified rvalue reference to T.
4129   QualType ArgType = CtorType->getArgType(0);
4130   if (ArgType->getPointeeType().isVolatileQualified()) {
4131     Diag(CD->getLocation(), diag::err_defaulted_move_ctor_volatile_param);
4132     HadError = true;
4133   }
4134   if (ArgType->getPointeeType().isConstQualified()) {
4135     Diag(CD->getLocation(), diag::err_defaulted_move_ctor_const_param);
4136     HadError = true;
4137   }
4138 
4139   // C++11 [dcl.fct.def.default]p2:
4140   //   An explicitly-defaulted function may be declared constexpr only if it
4141   //   would have been implicitly declared as constexpr,
4142   // Do not apply this rule to templates, since core issue 1358 makes such
4143   // functions always instantiate to constexpr functions.
4144   if (CD->isConstexpr() &&
4145       CD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
4146     if (!CD->getParent()->defaultedMoveConstructorIsConstexpr()) {
4147       Diag(CD->getLocStart(), diag::err_incorrect_defaulted_constexpr)
4148         << CXXMoveConstructor;
4149       HadError = true;
4150     }
4151   }
4152   //   and may have an explicit exception-specification only if it is compatible
4153   //   with the exception-specification on the implicit declaration.
4154   if (CtorType->hasExceptionSpec()) {
4155     if (CheckEquivalentExceptionSpec(
4156           PDiag(diag::err_incorrect_defaulted_exception_spec)
4157             << CXXMoveConstructor,
4158           PDiag(),
4159           ExceptionType, SourceLocation(),
4160           CtorType, CD->getLocation())) {
4161       HadError = true;
4162     }
4163   }
4164 
4165   //   If a function is explicitly defaulted on its first declaration,
4166   if (First) {
4167     //  -- it is implicitly considered to be constexpr if the implicit
4168     //     definition would be,
4169     CD->setConstexpr(CD->getParent()->defaultedMoveConstructorIsConstexpr());
4170 
4171     //  -- it is implicitly considered to have the same
4172     //     exception-specification as if it had been implicitly declared, and
4173     //
4174     // FIXME: a compatible, but different, explicit exception specification
4175     // will be silently overridden. We should issue a warning if this happens.
4176     EPI.ExtInfo = CtorType->getExtInfo();
4177 
4178     //  -- [...] it shall have the same parameter type as if it had been
4179     //     implicitly declared.
4180     CD->setType(Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI));
4181 
4182     // Such a function is also trivial if the implicitly-declared function
4183     // would have been.
4184     CD->setTrivial(CD->getParent()->hasTrivialMoveConstructor());
4185   }
4186 
4187   if (HadError) {
4188     CD->setInvalidDecl();
4189     return;
4190   }
4191 
4192   if (ShouldDeleteSpecialMember(CD, CXXMoveConstructor)) {
4193     if (First) {
4194       CD->setDeletedAsWritten();
4195     } else {
4196       Diag(CD->getLocation(), diag::err_out_of_line_default_deletes)
4197         << CXXMoveConstructor;
4198       CD->setInvalidDecl();
4199     }
4200   }
4201 }
4202 
CheckExplicitlyDefaultedMoveAssignment(CXXMethodDecl * MD)4203 void Sema::CheckExplicitlyDefaultedMoveAssignment(CXXMethodDecl *MD) {
4204   assert(MD->isExplicitlyDefaulted());
4205 
4206   // Whether this was the first-declared instance of the operator
4207   bool First = MD == MD->getCanonicalDecl();
4208 
4209   bool HadError = false;
4210   if (MD->getNumParams() != 1) {
4211     Diag(MD->getLocation(), diag::err_defaulted_move_assign_params)
4212       << MD->getSourceRange();
4213     HadError = true;
4214   }
4215 
4216   QualType ReturnType =
4217     MD->getType()->getAs<FunctionType>()->getResultType();
4218   if (!ReturnType->isLValueReferenceType() ||
4219       !Context.hasSameType(
4220         Context.getCanonicalType(ReturnType->getPointeeType()),
4221         Context.getCanonicalType(Context.getTypeDeclType(MD->getParent())))) {
4222     Diag(MD->getLocation(), diag::err_defaulted_move_assign_return_type);
4223     HadError = true;
4224   }
4225 
4226   ImplicitExceptionSpecification Spec(
4227       ComputeDefaultedMoveCtorExceptionSpec(MD->getParent()));
4228 
4229   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
4230   const FunctionProtoType *OperType = MD->getType()->getAs<FunctionProtoType>(),
4231                           *ExceptionType = Context.getFunctionType(
4232                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
4233 
4234   QualType ArgType = OperType->getArgType(0);
4235   if (!ArgType->isRValueReferenceType()) {
4236     Diag(MD->getLocation(), diag::err_defaulted_move_assign_not_ref);
4237     HadError = true;
4238   } else {
4239     if (ArgType->getPointeeType().isVolatileQualified()) {
4240       Diag(MD->getLocation(), diag::err_defaulted_move_assign_volatile_param);
4241       HadError = true;
4242     }
4243     if (ArgType->getPointeeType().isConstQualified()) {
4244       Diag(MD->getLocation(), diag::err_defaulted_move_assign_const_param);
4245       HadError = true;
4246     }
4247   }
4248 
4249   if (OperType->getTypeQuals()) {
4250     Diag(MD->getLocation(), diag::err_defaulted_move_assign_quals);
4251     HadError = true;
4252   }
4253 
4254   if (OperType->hasExceptionSpec()) {
4255     if (CheckEquivalentExceptionSpec(
4256           PDiag(diag::err_incorrect_defaulted_exception_spec)
4257             << CXXMoveAssignment,
4258           PDiag(),
4259           ExceptionType, SourceLocation(),
4260           OperType, MD->getLocation())) {
4261       HadError = true;
4262     }
4263   }
4264   if (First) {
4265     // We set the declaration to have the computed exception spec here.
4266     // We duplicate the one parameter type.
4267     EPI.RefQualifier = OperType->getRefQualifier();
4268     EPI.ExtInfo = OperType->getExtInfo();
4269     MD->setType(Context.getFunctionType(ReturnType, &ArgType, 1, EPI));
4270 
4271     // Such a function is also trivial if the implicitly-declared function
4272     // would have been.
4273     MD->setTrivial(MD->getParent()->hasTrivialMoveAssignment());
4274   }
4275 
4276   if (HadError) {
4277     MD->setInvalidDecl();
4278     return;
4279   }
4280 
4281   if (ShouldDeleteSpecialMember(MD, CXXMoveAssignment)) {
4282     if (First) {
4283       MD->setDeletedAsWritten();
4284     } else {
4285       Diag(MD->getLocation(), diag::err_out_of_line_default_deletes)
4286         << CXXMoveAssignment;
4287       MD->setInvalidDecl();
4288     }
4289   }
4290 }
4291 
CheckExplicitlyDefaultedDestructor(CXXDestructorDecl * DD)4292 void Sema::CheckExplicitlyDefaultedDestructor(CXXDestructorDecl *DD) {
4293   assert(DD->isExplicitlyDefaulted());
4294 
4295   // Whether this was the first-declared instance of the destructor.
4296   bool First = DD == DD->getCanonicalDecl();
4297 
4298   ImplicitExceptionSpecification Spec
4299     = ComputeDefaultedDtorExceptionSpec(DD->getParent());
4300   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
4301   const FunctionProtoType *DtorType = DD->getType()->getAs<FunctionProtoType>(),
4302                           *ExceptionType = Context.getFunctionType(
4303                          Context.VoidTy, 0, 0, EPI)->getAs<FunctionProtoType>();
4304 
4305   if (DtorType->hasExceptionSpec()) {
4306     if (CheckEquivalentExceptionSpec(
4307           PDiag(diag::err_incorrect_defaulted_exception_spec)
4308             << CXXDestructor,
4309           PDiag(),
4310           ExceptionType, SourceLocation(),
4311           DtorType, DD->getLocation())) {
4312       DD->setInvalidDecl();
4313       return;
4314     }
4315   }
4316   if (First) {
4317     // We set the declaration to have the computed exception spec here.
4318     // There are no parameters.
4319     EPI.ExtInfo = DtorType->getExtInfo();
4320     DD->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
4321 
4322     // Such a function is also trivial if the implicitly-declared function
4323     // would have been.
4324     DD->setTrivial(DD->getParent()->hasTrivialDestructor());
4325   }
4326 
4327   if (ShouldDeleteSpecialMember(DD, CXXDestructor)) {
4328     if (First) {
4329       DD->setDeletedAsWritten();
4330     } else {
4331       Diag(DD->getLocation(), diag::err_out_of_line_default_deletes)
4332         << CXXDestructor;
4333       DD->setInvalidDecl();
4334     }
4335   }
4336 }
4337 
4338 namespace {
4339 struct SpecialMemberDeletionInfo {
4340   Sema &S;
4341   CXXMethodDecl *MD;
4342   Sema::CXXSpecialMember CSM;
4343   bool Diagnose;
4344 
4345   // Properties of the special member, computed for convenience.
4346   bool IsConstructor, IsAssignment, IsMove, ConstArg, VolatileArg;
4347   SourceLocation Loc;
4348 
4349   bool AllFieldsAreConst;
4350 
SpecialMemberDeletionInfo__anon01e4a4a60611::SpecialMemberDeletionInfo4351   SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
4352                             Sema::CXXSpecialMember CSM, bool Diagnose)
4353     : S(S), MD(MD), CSM(CSM), Diagnose(Diagnose),
4354       IsConstructor(false), IsAssignment(false), IsMove(false),
4355       ConstArg(false), VolatileArg(false), Loc(MD->getLocation()),
4356       AllFieldsAreConst(true) {
4357     switch (CSM) {
4358       case Sema::CXXDefaultConstructor:
4359       case Sema::CXXCopyConstructor:
4360         IsConstructor = true;
4361         break;
4362       case Sema::CXXMoveConstructor:
4363         IsConstructor = true;
4364         IsMove = true;
4365         break;
4366       case Sema::CXXCopyAssignment:
4367         IsAssignment = true;
4368         break;
4369       case Sema::CXXMoveAssignment:
4370         IsAssignment = true;
4371         IsMove = true;
4372         break;
4373       case Sema::CXXDestructor:
4374         break;
4375       case Sema::CXXInvalid:
4376         llvm_unreachable("invalid special member kind");
4377     }
4378 
4379     if (MD->getNumParams()) {
4380       ConstArg = MD->getParamDecl(0)->getType().isConstQualified();
4381       VolatileArg = MD->getParamDecl(0)->getType().isVolatileQualified();
4382     }
4383   }
4384 
inUnion__anon01e4a4a60611::SpecialMemberDeletionInfo4385   bool inUnion() const { return MD->getParent()->isUnion(); }
4386 
4387   /// Look up the corresponding special member in the given class.
lookupIn__anon01e4a4a60611::SpecialMemberDeletionInfo4388   Sema::SpecialMemberOverloadResult *lookupIn(CXXRecordDecl *Class) {
4389     unsigned TQ = MD->getTypeQualifiers();
4390     return S.LookupSpecialMember(Class, CSM, ConstArg, VolatileArg,
4391                                  MD->getRefQualifier() == RQ_RValue,
4392                                  TQ & Qualifiers::Const,
4393                                  TQ & Qualifiers::Volatile);
4394   }
4395 
4396   typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
4397 
4398   bool shouldDeleteForBase(CXXBaseSpecifier *Base);
4399   bool shouldDeleteForField(FieldDecl *FD);
4400   bool shouldDeleteForAllConstMembers();
4401 
4402   bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj);
4403   bool shouldDeleteForSubobjectCall(Subobject Subobj,
4404                                     Sema::SpecialMemberOverloadResult *SMOR,
4405                                     bool IsDtorCallInCtor);
4406 
4407   bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
4408 };
4409 }
4410 
4411 /// Is the given special member inaccessible when used on the given
4412 /// sub-object.
isAccessible(Subobject Subobj,CXXMethodDecl * target)4413 bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
4414                                              CXXMethodDecl *target) {
4415   /// If we're operating on a base class, the object type is the
4416   /// type of this special member.
4417   QualType objectTy;
4418   AccessSpecifier access = target->getAccess();;
4419   if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
4420     objectTy = S.Context.getTypeDeclType(MD->getParent());
4421     access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
4422 
4423   // If we're operating on a field, the object type is the type of the field.
4424   } else {
4425     objectTy = S.Context.getTypeDeclType(target->getParent());
4426   }
4427 
4428   return S.isSpecialMemberAccessibleForDeletion(target, access, objectTy);
4429 }
4430 
4431 /// Check whether we should delete a special member due to the implicit
4432 /// definition containing a call to a special member of a subobject.
shouldDeleteForSubobjectCall(Subobject Subobj,Sema::SpecialMemberOverloadResult * SMOR,bool IsDtorCallInCtor)4433 bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
4434     Subobject Subobj, Sema::SpecialMemberOverloadResult *SMOR,
4435     bool IsDtorCallInCtor) {
4436   CXXMethodDecl *Decl = SMOR->getMethod();
4437   FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4438 
4439   int DiagKind = -1;
4440 
4441   if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
4442     DiagKind = !Decl ? 0 : 1;
4443   else if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
4444     DiagKind = 2;
4445   else if (!isAccessible(Subobj, Decl))
4446     DiagKind = 3;
4447   else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
4448            !Decl->isTrivial()) {
4449     // A member of a union must have a trivial corresponding special member.
4450     // As a weird special case, a destructor call from a union's constructor
4451     // must be accessible and non-deleted, but need not be trivial. Such a
4452     // destructor is never actually called, but is semantically checked as
4453     // if it were.
4454     DiagKind = 4;
4455   }
4456 
4457   if (DiagKind == -1)
4458     return false;
4459 
4460   if (Diagnose) {
4461     if (Field) {
4462       S.Diag(Field->getLocation(),
4463              diag::note_deleted_special_member_class_subobject)
4464         << CSM << MD->getParent() << /*IsField*/true
4465         << Field << DiagKind << IsDtorCallInCtor;
4466     } else {
4467       CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
4468       S.Diag(Base->getLocStart(),
4469              diag::note_deleted_special_member_class_subobject)
4470         << CSM << MD->getParent() << /*IsField*/false
4471         << Base->getType() << DiagKind << IsDtorCallInCtor;
4472     }
4473 
4474     if (DiagKind == 1)
4475       S.NoteDeletedFunction(Decl);
4476     // FIXME: Explain inaccessibility if DiagKind == 3.
4477   }
4478 
4479   return true;
4480 }
4481 
4482 /// Check whether we should delete a special member function due to having a
4483 /// direct or virtual base class or static data member of class type M.
shouldDeleteForClassSubobject(CXXRecordDecl * Class,Subobject Subobj)4484 bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
4485     CXXRecordDecl *Class, Subobject Subobj) {
4486   FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
4487 
4488   // C++11 [class.ctor]p5:
4489   // -- any direct or virtual base class, or non-static data member with no
4490   //    brace-or-equal-initializer, has class type M (or array thereof) and
4491   //    either M has no default constructor or overload resolution as applied
4492   //    to M's default constructor results in an ambiguity or in a function
4493   //    that is deleted or inaccessible
4494   // C++11 [class.copy]p11, C++11 [class.copy]p23:
4495   // -- a direct or virtual base class B that cannot be copied/moved because
4496   //    overload resolution, as applied to B's corresponding special member,
4497   //    results in an ambiguity or a function that is deleted or inaccessible
4498   //    from the defaulted special member
4499   // C++11 [class.dtor]p5:
4500   // -- any direct or virtual base class [...] has a type with a destructor
4501   //    that is deleted or inaccessible
4502   if (!(CSM == Sema::CXXDefaultConstructor &&
4503         Field && Field->hasInClassInitializer()) &&
4504       shouldDeleteForSubobjectCall(Subobj, lookupIn(Class), false))
4505     return true;
4506 
4507   // C++11 [class.ctor]p5, C++11 [class.copy]p11:
4508   // -- any direct or virtual base class or non-static data member has a
4509   //    type with a destructor that is deleted or inaccessible
4510   if (IsConstructor) {
4511     Sema::SpecialMemberOverloadResult *SMOR =
4512         S.LookupSpecialMember(Class, Sema::CXXDestructor,
4513                               false, false, false, false, false);
4514     if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
4515       return true;
4516   }
4517 
4518   return false;
4519 }
4520 
4521 /// Check whether we should delete a special member function due to the class
4522 /// having a particular direct or virtual base class.
shouldDeleteForBase(CXXBaseSpecifier * Base)4523 bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
4524   CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
4525   return shouldDeleteForClassSubobject(BaseClass, Base);
4526 }
4527 
4528 /// Check whether we should delete a special member function due to the class
4529 /// having a particular non-static data member.
shouldDeleteForField(FieldDecl * FD)4530 bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
4531   QualType FieldType = S.Context.getBaseElementType(FD->getType());
4532   CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
4533 
4534   if (CSM == Sema::CXXDefaultConstructor) {
4535     // For a default constructor, all references must be initialized in-class
4536     // and, if a union, it must have a non-const member.
4537     if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
4538       if (Diagnose)
4539         S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4540           << MD->getParent() << FD << FieldType << /*Reference*/0;
4541       return true;
4542     }
4543     // C++11 [class.ctor]p5: any non-variant non-static data member of
4544     // const-qualified type (or array thereof) with no
4545     // brace-or-equal-initializer does not have a user-provided default
4546     // constructor.
4547     if (!inUnion() && FieldType.isConstQualified() &&
4548         !FD->hasInClassInitializer() &&
4549         (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
4550       if (Diagnose)
4551         S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
4552           << MD->getParent() << FD << FieldType << /*Const*/1;
4553       return true;
4554     }
4555 
4556     if (inUnion() && !FieldType.isConstQualified())
4557       AllFieldsAreConst = false;
4558   } else if (CSM == Sema::CXXCopyConstructor) {
4559     // For a copy constructor, data members must not be of rvalue reference
4560     // type.
4561     if (FieldType->isRValueReferenceType()) {
4562       if (Diagnose)
4563         S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
4564           << MD->getParent() << FD << FieldType;
4565       return true;
4566     }
4567   } else if (IsAssignment) {
4568     // For an assignment operator, data members must not be of reference type.
4569     if (FieldType->isReferenceType()) {
4570       if (Diagnose)
4571         S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4572           << IsMove << MD->getParent() << FD << FieldType << /*Reference*/0;
4573       return true;
4574     }
4575     if (!FieldRecord && FieldType.isConstQualified()) {
4576       // C++11 [class.copy]p23:
4577       // -- a non-static data member of const non-class type (or array thereof)
4578       if (Diagnose)
4579         S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
4580           << IsMove << MD->getParent() << FD << FieldType << /*Const*/1;
4581       return true;
4582     }
4583   }
4584 
4585   if (FieldRecord) {
4586     // Some additional restrictions exist on the variant members.
4587     if (!inUnion() && FieldRecord->isUnion() &&
4588         FieldRecord->isAnonymousStructOrUnion()) {
4589       bool AllVariantFieldsAreConst = true;
4590 
4591       // FIXME: Handle anonymous unions declared within anonymous unions.
4592       for (CXXRecordDecl::field_iterator UI = FieldRecord->field_begin(),
4593                                          UE = FieldRecord->field_end();
4594            UI != UE; ++UI) {
4595         QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
4596 
4597         if (!UnionFieldType.isConstQualified())
4598           AllVariantFieldsAreConst = false;
4599 
4600         CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
4601         if (UnionFieldRecord &&
4602             shouldDeleteForClassSubobject(UnionFieldRecord, *UI))
4603           return true;
4604       }
4605 
4606       // At least one member in each anonymous union must be non-const
4607       if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
4608           FieldRecord->field_begin() != FieldRecord->field_end()) {
4609         if (Diagnose)
4610           S.Diag(FieldRecord->getLocation(),
4611                  diag::note_deleted_default_ctor_all_const)
4612             << MD->getParent() << /*anonymous union*/1;
4613         return true;
4614       }
4615 
4616       // Don't check the implicit member of the anonymous union type.
4617       // This is technically non-conformant, but sanity demands it.
4618       return false;
4619     }
4620 
4621     if (shouldDeleteForClassSubobject(FieldRecord, FD))
4622       return true;
4623   }
4624 
4625   return false;
4626 }
4627 
4628 /// C++11 [class.ctor] p5:
4629 ///   A defaulted default constructor for a class X is defined as deleted if
4630 /// X is a union and all of its variant members are of const-qualified type.
shouldDeleteForAllConstMembers()4631 bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
4632   // This is a silly definition, because it gives an empty union a deleted
4633   // default constructor. Don't do that.
4634   if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst &&
4635       (MD->getParent()->field_begin() != MD->getParent()->field_end())) {
4636     if (Diagnose)
4637       S.Diag(MD->getParent()->getLocation(),
4638              diag::note_deleted_default_ctor_all_const)
4639         << MD->getParent() << /*not anonymous union*/0;
4640     return true;
4641   }
4642   return false;
4643 }
4644 
4645 /// Determine whether a defaulted special member function should be defined as
4646 /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
4647 /// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
ShouldDeleteSpecialMember(CXXMethodDecl * MD,CXXSpecialMember CSM,bool Diagnose)4648 bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
4649                                      bool Diagnose) {
4650   assert(!MD->isInvalidDecl());
4651   CXXRecordDecl *RD = MD->getParent();
4652   assert(!RD->isDependentType() && "do deletion after instantiation");
4653   if (!LangOpts.CPlusPlus0x || RD->isInvalidDecl())
4654     return false;
4655 
4656   // C++11 [expr.lambda.prim]p19:
4657   //   The closure type associated with a lambda-expression has a
4658   //   deleted (8.4.3) default constructor and a deleted copy
4659   //   assignment operator.
4660   if (RD->isLambda() &&
4661       (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
4662     if (Diagnose)
4663       Diag(RD->getLocation(), diag::note_lambda_decl);
4664     return true;
4665   }
4666 
4667   // For an anonymous struct or union, the copy and assignment special members
4668   // will never be used, so skip the check. For an anonymous union declared at
4669   // namespace scope, the constructor and destructor are used.
4670   if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
4671       RD->isAnonymousStructOrUnion())
4672     return false;
4673 
4674   // C++11 [class.copy]p7, p18:
4675   //   If the class definition declares a move constructor or move assignment
4676   //   operator, an implicitly declared copy constructor or copy assignment
4677   //   operator is defined as deleted.
4678   if (MD->isImplicit() &&
4679       (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
4680     CXXMethodDecl *UserDeclaredMove = 0;
4681 
4682     // In Microsoft mode, a user-declared move only causes the deletion of the
4683     // corresponding copy operation, not both copy operations.
4684     if (RD->hasUserDeclaredMoveConstructor() &&
4685         (!getLangOpts().MicrosoftMode || CSM == CXXCopyConstructor)) {
4686       if (!Diagnose) return true;
4687       UserDeclaredMove = RD->getMoveConstructor();
4688       assert(UserDeclaredMove);
4689     } else if (RD->hasUserDeclaredMoveAssignment() &&
4690                (!getLangOpts().MicrosoftMode || CSM == CXXCopyAssignment)) {
4691       if (!Diagnose) return true;
4692       UserDeclaredMove = RD->getMoveAssignmentOperator();
4693       assert(UserDeclaredMove);
4694     }
4695 
4696     if (UserDeclaredMove) {
4697       Diag(UserDeclaredMove->getLocation(),
4698            diag::note_deleted_copy_user_declared_move)
4699         << (CSM == CXXCopyAssignment) << RD
4700         << UserDeclaredMove->isMoveAssignmentOperator();
4701       return true;
4702     }
4703   }
4704 
4705   // Do access control from the special member function
4706   ContextRAII MethodContext(*this, MD);
4707 
4708   // C++11 [class.dtor]p5:
4709   // -- for a virtual destructor, lookup of the non-array deallocation function
4710   //    results in an ambiguity or in a function that is deleted or inaccessible
4711   if (CSM == CXXDestructor && MD->isVirtual()) {
4712     FunctionDecl *OperatorDelete = 0;
4713     DeclarationName Name =
4714       Context.DeclarationNames.getCXXOperatorName(OO_Delete);
4715     if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
4716                                  OperatorDelete, false)) {
4717       if (Diagnose)
4718         Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
4719       return true;
4720     }
4721   }
4722 
4723   SpecialMemberDeletionInfo SMI(*this, MD, CSM, Diagnose);
4724 
4725   for (CXXRecordDecl::base_class_iterator BI = RD->bases_begin(),
4726                                           BE = RD->bases_end(); BI != BE; ++BI)
4727     if (!BI->isVirtual() &&
4728         SMI.shouldDeleteForBase(BI))
4729       return true;
4730 
4731   for (CXXRecordDecl::base_class_iterator BI = RD->vbases_begin(),
4732                                           BE = RD->vbases_end(); BI != BE; ++BI)
4733     if (SMI.shouldDeleteForBase(BI))
4734       return true;
4735 
4736   for (CXXRecordDecl::field_iterator FI = RD->field_begin(),
4737                                      FE = RD->field_end(); FI != FE; ++FI)
4738     if (!FI->isInvalidDecl() && !FI->isUnnamedBitfield() &&
4739         SMI.shouldDeleteForField(*FI))
4740       return true;
4741 
4742   if (SMI.shouldDeleteForAllConstMembers())
4743     return true;
4744 
4745   return false;
4746 }
4747 
4748 /// \brief Data used with FindHiddenVirtualMethod
4749 namespace {
4750   struct FindHiddenVirtualMethodData {
4751     Sema *S;
4752     CXXMethodDecl *Method;
4753     llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
4754     SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
4755   };
4756 }
4757 
4758 /// \brief Member lookup function that determines whether a given C++
4759 /// method overloads virtual methods in a base class without overriding any,
4760 /// to be used with CXXRecordDecl::lookupInBases().
FindHiddenVirtualMethod(const CXXBaseSpecifier * Specifier,CXXBasePath & Path,void * UserData)4761 static bool FindHiddenVirtualMethod(const CXXBaseSpecifier *Specifier,
4762                                     CXXBasePath &Path,
4763                                     void *UserData) {
4764   RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
4765 
4766   FindHiddenVirtualMethodData &Data
4767     = *static_cast<FindHiddenVirtualMethodData*>(UserData);
4768 
4769   DeclarationName Name = Data.Method->getDeclName();
4770   assert(Name.getNameKind() == DeclarationName::Identifier);
4771 
4772   bool foundSameNameMethod = false;
4773   SmallVector<CXXMethodDecl *, 8> overloadedMethods;
4774   for (Path.Decls = BaseRecord->lookup(Name);
4775        Path.Decls.first != Path.Decls.second;
4776        ++Path.Decls.first) {
4777     NamedDecl *D = *Path.Decls.first;
4778     if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
4779       MD = MD->getCanonicalDecl();
4780       foundSameNameMethod = true;
4781       // Interested only in hidden virtual methods.
4782       if (!MD->isVirtual())
4783         continue;
4784       // If the method we are checking overrides a method from its base
4785       // don't warn about the other overloaded methods.
4786       if (!Data.S->IsOverload(Data.Method, MD, false))
4787         return true;
4788       // Collect the overload only if its hidden.
4789       if (!Data.OverridenAndUsingBaseMethods.count(MD))
4790         overloadedMethods.push_back(MD);
4791     }
4792   }
4793 
4794   if (foundSameNameMethod)
4795     Data.OverloadedMethods.append(overloadedMethods.begin(),
4796                                    overloadedMethods.end());
4797   return foundSameNameMethod;
4798 }
4799 
4800 /// \brief See if a method overloads virtual methods in a base class without
4801 /// overriding any.
DiagnoseHiddenVirtualMethods(CXXRecordDecl * DC,CXXMethodDecl * MD)4802 void Sema::DiagnoseHiddenVirtualMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
4803   if (Diags.getDiagnosticLevel(diag::warn_overloaded_virtual,
4804                                MD->getLocation()) == DiagnosticsEngine::Ignored)
4805     return;
4806   if (MD->getDeclName().getNameKind() != DeclarationName::Identifier)
4807     return;
4808 
4809   CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
4810                      /*bool RecordPaths=*/false,
4811                      /*bool DetectVirtual=*/false);
4812   FindHiddenVirtualMethodData Data;
4813   Data.Method = MD;
4814   Data.S = this;
4815 
4816   // Keep the base methods that were overriden or introduced in the subclass
4817   // by 'using' in a set. A base method not in this set is hidden.
4818   for (DeclContext::lookup_result res = DC->lookup(MD->getDeclName());
4819        res.first != res.second; ++res.first) {
4820     if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*res.first))
4821       for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
4822                                           E = MD->end_overridden_methods();
4823            I != E; ++I)
4824         Data.OverridenAndUsingBaseMethods.insert((*I)->getCanonicalDecl());
4825     if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*res.first))
4826       if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(shad->getTargetDecl()))
4827         Data.OverridenAndUsingBaseMethods.insert(MD->getCanonicalDecl());
4828   }
4829 
4830   if (DC->lookupInBases(&FindHiddenVirtualMethod, &Data, Paths) &&
4831       !Data.OverloadedMethods.empty()) {
4832     Diag(MD->getLocation(), diag::warn_overloaded_virtual)
4833       << MD << (Data.OverloadedMethods.size() > 1);
4834 
4835     for (unsigned i = 0, e = Data.OverloadedMethods.size(); i != e; ++i) {
4836       CXXMethodDecl *overloadedMD = Data.OverloadedMethods[i];
4837       Diag(overloadedMD->getLocation(),
4838            diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
4839     }
4840   }
4841 }
4842 
ActOnFinishCXXMemberSpecification(Scope * S,SourceLocation RLoc,Decl * TagDecl,SourceLocation LBrac,SourceLocation RBrac,AttributeList * AttrList)4843 void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
4844                                              Decl *TagDecl,
4845                                              SourceLocation LBrac,
4846                                              SourceLocation RBrac,
4847                                              AttributeList *AttrList) {
4848   if (!TagDecl)
4849     return;
4850 
4851   AdjustDeclIfTemplate(TagDecl);
4852 
4853   ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
4854               // strict aliasing violation!
4855               reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
4856               FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
4857 
4858   CheckCompletedCXXClass(
4859                         dyn_cast_or_null<CXXRecordDecl>(TagDecl));
4860 }
4861 
4862 /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
4863 /// special functions, such as the default constructor, copy
4864 /// constructor, or destructor, to the given C++ class (C++
4865 /// [special]p1).  This routine can only be executed just before the
4866 /// definition of the class is complete.
AddImplicitlyDeclaredMembersToClass(CXXRecordDecl * ClassDecl)4867 void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
4868   if (!ClassDecl->hasUserDeclaredConstructor())
4869     ++ASTContext::NumImplicitDefaultConstructors;
4870 
4871   if (!ClassDecl->hasUserDeclaredCopyConstructor())
4872     ++ASTContext::NumImplicitCopyConstructors;
4873 
4874   if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveConstructor())
4875     ++ASTContext::NumImplicitMoveConstructors;
4876 
4877   if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
4878     ++ASTContext::NumImplicitCopyAssignmentOperators;
4879 
4880     // If we have a dynamic class, then the copy assignment operator may be
4881     // virtual, so we have to declare it immediately. This ensures that, e.g.,
4882     // it shows up in the right place in the vtable and that we diagnose
4883     // problems with the implicit exception specification.
4884     if (ClassDecl->isDynamicClass())
4885       DeclareImplicitCopyAssignment(ClassDecl);
4886   }
4887 
4888   if (getLangOpts().CPlusPlus0x && ClassDecl->needsImplicitMoveAssignment()) {
4889     ++ASTContext::NumImplicitMoveAssignmentOperators;
4890 
4891     // Likewise for the move assignment operator.
4892     if (ClassDecl->isDynamicClass())
4893       DeclareImplicitMoveAssignment(ClassDecl);
4894   }
4895 
4896   if (!ClassDecl->hasUserDeclaredDestructor()) {
4897     ++ASTContext::NumImplicitDestructors;
4898 
4899     // If we have a dynamic class, then the destructor may be virtual, so we
4900     // have to declare the destructor immediately. This ensures that, e.g., it
4901     // shows up in the right place in the vtable and that we diagnose problems
4902     // with the implicit exception specification.
4903     if (ClassDecl->isDynamicClass())
4904       DeclareImplicitDestructor(ClassDecl);
4905   }
4906 }
4907 
ActOnReenterDeclaratorTemplateScope(Scope * S,DeclaratorDecl * D)4908 void Sema::ActOnReenterDeclaratorTemplateScope(Scope *S, DeclaratorDecl *D) {
4909   if (!D)
4910     return;
4911 
4912   int NumParamList = D->getNumTemplateParameterLists();
4913   for (int i = 0; i < NumParamList; i++) {
4914     TemplateParameterList* Params = D->getTemplateParameterList(i);
4915     for (TemplateParameterList::iterator Param = Params->begin(),
4916                                       ParamEnd = Params->end();
4917           Param != ParamEnd; ++Param) {
4918       NamedDecl *Named = cast<NamedDecl>(*Param);
4919       if (Named->getDeclName()) {
4920         S->AddDecl(Named);
4921         IdResolver.AddDecl(Named);
4922       }
4923     }
4924   }
4925 }
4926 
ActOnReenterTemplateScope(Scope * S,Decl * D)4927 void Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) {
4928   if (!D)
4929     return;
4930 
4931   TemplateParameterList *Params = 0;
4932   if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D))
4933     Params = Template->getTemplateParameters();
4934   else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4935            = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
4936     Params = PartialSpec->getTemplateParameters();
4937   else
4938     return;
4939 
4940   for (TemplateParameterList::iterator Param = Params->begin(),
4941                                     ParamEnd = Params->end();
4942        Param != ParamEnd; ++Param) {
4943     NamedDecl *Named = cast<NamedDecl>(*Param);
4944     if (Named->getDeclName()) {
4945       S->AddDecl(Named);
4946       IdResolver.AddDecl(Named);
4947     }
4948   }
4949 }
4950 
ActOnStartDelayedMemberDeclarations(Scope * S,Decl * RecordD)4951 void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4952   if (!RecordD) return;
4953   AdjustDeclIfTemplate(RecordD);
4954   CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
4955   PushDeclContext(S, Record);
4956 }
4957 
ActOnFinishDelayedMemberDeclarations(Scope * S,Decl * RecordD)4958 void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
4959   if (!RecordD) return;
4960   PopDeclContext();
4961 }
4962 
4963 /// ActOnStartDelayedCXXMethodDeclaration - We have completed
4964 /// parsing a top-level (non-nested) C++ class, and we are now
4965 /// parsing those parts of the given Method declaration that could
4966 /// not be parsed earlier (C++ [class.mem]p2), such as default
4967 /// arguments. This action should enter the scope of the given
4968 /// Method declaration as if we had just parsed the qualified method
4969 /// name. However, it should not bring the parameters into scope;
4970 /// that will be performed by ActOnDelayedCXXMethodParameter.
ActOnStartDelayedCXXMethodDeclaration(Scope * S,Decl * MethodD)4971 void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
4972 }
4973 
4974 /// ActOnDelayedCXXMethodParameter - We've already started a delayed
4975 /// C++ method declaration. We're (re-)introducing the given
4976 /// function parameter into scope for use in parsing later parts of
4977 /// the method declaration. For example, we could see an
4978 /// ActOnParamDefaultArgument event for this parameter.
ActOnDelayedCXXMethodParameter(Scope * S,Decl * ParamD)4979 void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
4980   if (!ParamD)
4981     return;
4982 
4983   ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
4984 
4985   // If this parameter has an unparsed default argument, clear it out
4986   // to make way for the parsed default argument.
4987   if (Param->hasUnparsedDefaultArg())
4988     Param->setDefaultArg(0);
4989 
4990   S->AddDecl(Param);
4991   if (Param->getDeclName())
4992     IdResolver.AddDecl(Param);
4993 }
4994 
4995 /// ActOnFinishDelayedCXXMethodDeclaration - We have finished
4996 /// processing the delayed method declaration for Method. The method
4997 /// declaration is now considered finished. There may be a separate
4998 /// ActOnStartOfFunctionDef action later (not necessarily
4999 /// immediately!) for this method, if it was also defined inside the
5000 /// class body.
ActOnFinishDelayedCXXMethodDeclaration(Scope * S,Decl * MethodD)5001 void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
5002   if (!MethodD)
5003     return;
5004 
5005   AdjustDeclIfTemplate(MethodD);
5006 
5007   FunctionDecl *Method = cast<FunctionDecl>(MethodD);
5008 
5009   // Now that we have our default arguments, check the constructor
5010   // again. It could produce additional diagnostics or affect whether
5011   // the class has implicitly-declared destructors, among other
5012   // things.
5013   if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
5014     CheckConstructor(Constructor);
5015 
5016   // Check the default arguments, which we may have added.
5017   if (!Method->isInvalidDecl())
5018     CheckCXXDefaultArguments(Method);
5019 }
5020 
5021 /// CheckConstructorDeclarator - Called by ActOnDeclarator to check
5022 /// the well-formedness of the constructor declarator @p D with type @p
5023 /// R. If there are any errors in the declarator, this routine will
5024 /// emit diagnostics and set the invalid bit to true.  In any case, the type
5025 /// will be updated to reflect a well-formed type for the constructor and
5026 /// returned.
CheckConstructorDeclarator(Declarator & D,QualType R,StorageClass & SC)5027 QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
5028                                           StorageClass &SC) {
5029   bool isVirtual = D.getDeclSpec().isVirtualSpecified();
5030 
5031   // C++ [class.ctor]p3:
5032   //   A constructor shall not be virtual (10.3) or static (9.4). A
5033   //   constructor can be invoked for a const, volatile or const
5034   //   volatile object. A constructor shall not be declared const,
5035   //   volatile, or const volatile (9.3.2).
5036   if (isVirtual) {
5037     if (!D.isInvalidType())
5038       Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
5039         << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
5040         << SourceRange(D.getIdentifierLoc());
5041     D.setInvalidType();
5042   }
5043   if (SC == SC_Static) {
5044     if (!D.isInvalidType())
5045       Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
5046         << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5047         << SourceRange(D.getIdentifierLoc());
5048     D.setInvalidType();
5049     SC = SC_None;
5050   }
5051 
5052   DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
5053   if (FTI.TypeQuals != 0) {
5054     if (FTI.TypeQuals & Qualifiers::Const)
5055       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
5056         << "const" << SourceRange(D.getIdentifierLoc());
5057     if (FTI.TypeQuals & Qualifiers::Volatile)
5058       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
5059         << "volatile" << SourceRange(D.getIdentifierLoc());
5060     if (FTI.TypeQuals & Qualifiers::Restrict)
5061       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
5062         << "restrict" << SourceRange(D.getIdentifierLoc());
5063     D.setInvalidType();
5064   }
5065 
5066   // C++0x [class.ctor]p4:
5067   //   A constructor shall not be declared with a ref-qualifier.
5068   if (FTI.hasRefQualifier()) {
5069     Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
5070       << FTI.RefQualifierIsLValueRef
5071       << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
5072     D.setInvalidType();
5073   }
5074 
5075   // Rebuild the function type "R" without any type qualifiers (in
5076   // case any of the errors above fired) and with "void" as the
5077   // return type, since constructors don't have return types.
5078   const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5079   if (Proto->getResultType() == Context.VoidTy && !D.isInvalidType())
5080     return R;
5081 
5082   FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
5083   EPI.TypeQuals = 0;
5084   EPI.RefQualifier = RQ_None;
5085 
5086   return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
5087                                  Proto->getNumArgs(), EPI);
5088 }
5089 
5090 /// CheckConstructor - Checks a fully-formed constructor for
5091 /// well-formedness, issuing any diagnostics required. Returns true if
5092 /// the constructor declarator is invalid.
CheckConstructor(CXXConstructorDecl * Constructor)5093 void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
5094   CXXRecordDecl *ClassDecl
5095     = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
5096   if (!ClassDecl)
5097     return Constructor->setInvalidDecl();
5098 
5099   // C++ [class.copy]p3:
5100   //   A declaration of a constructor for a class X is ill-formed if
5101   //   its first parameter is of type (optionally cv-qualified) X and
5102   //   either there are no other parameters or else all other
5103   //   parameters have default arguments.
5104   if (!Constructor->isInvalidDecl() &&
5105       ((Constructor->getNumParams() == 1) ||
5106        (Constructor->getNumParams() > 1 &&
5107         Constructor->getParamDecl(1)->hasDefaultArg())) &&
5108       Constructor->getTemplateSpecializationKind()
5109                                               != TSK_ImplicitInstantiation) {
5110     QualType ParamType = Constructor->getParamDecl(0)->getType();
5111     QualType ClassTy = Context.getTagDeclType(ClassDecl);
5112     if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
5113       SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
5114       const char *ConstRef
5115         = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
5116                                                         : " const &";
5117       Diag(ParamLoc, diag::err_constructor_byvalue_arg)
5118         << FixItHint::CreateInsertion(ParamLoc, ConstRef);
5119 
5120       // FIXME: Rather that making the constructor invalid, we should endeavor
5121       // to fix the type.
5122       Constructor->setInvalidDecl();
5123     }
5124   }
5125 }
5126 
5127 /// CheckDestructor - Checks a fully-formed destructor definition for
5128 /// well-formedness, issuing any diagnostics required.  Returns true
5129 /// on error.
CheckDestructor(CXXDestructorDecl * Destructor)5130 bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
5131   CXXRecordDecl *RD = Destructor->getParent();
5132 
5133   if (Destructor->isVirtual()) {
5134     SourceLocation Loc;
5135 
5136     if (!Destructor->isImplicit())
5137       Loc = Destructor->getLocation();
5138     else
5139       Loc = RD->getLocation();
5140 
5141     // If we have a virtual destructor, look up the deallocation function
5142     FunctionDecl *OperatorDelete = 0;
5143     DeclarationName Name =
5144     Context.DeclarationNames.getCXXOperatorName(OO_Delete);
5145     if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
5146       return true;
5147 
5148     MarkFunctionReferenced(Loc, OperatorDelete);
5149 
5150     Destructor->setOperatorDelete(OperatorDelete);
5151   }
5152 
5153   return false;
5154 }
5155 
5156 static inline bool
FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo & FTI)5157 FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
5158   return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
5159           FTI.ArgInfo[0].Param &&
5160           cast<ParmVarDecl>(FTI.ArgInfo[0].Param)->getType()->isVoidType());
5161 }
5162 
5163 /// CheckDestructorDeclarator - Called by ActOnDeclarator to check
5164 /// the well-formednes of the destructor declarator @p D with type @p
5165 /// R. If there are any errors in the declarator, this routine will
5166 /// emit diagnostics and set the declarator to invalid.  Even if this happens,
5167 /// will be updated to reflect a well-formed type for the destructor and
5168 /// returned.
CheckDestructorDeclarator(Declarator & D,QualType R,StorageClass & SC)5169 QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
5170                                          StorageClass& SC) {
5171   // C++ [class.dtor]p1:
5172   //   [...] A typedef-name that names a class is a class-name
5173   //   (7.1.3); however, a typedef-name that names a class shall not
5174   //   be used as the identifier in the declarator for a destructor
5175   //   declaration.
5176   QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
5177   if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
5178     Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5179       << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
5180   else if (const TemplateSpecializationType *TST =
5181              DeclaratorType->getAs<TemplateSpecializationType>())
5182     if (TST->isTypeAlias())
5183       Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
5184         << DeclaratorType << 1;
5185 
5186   // C++ [class.dtor]p2:
5187   //   A destructor is used to destroy objects of its class type. A
5188   //   destructor takes no parameters, and no return type can be
5189   //   specified for it (not even void). The address of a destructor
5190   //   shall not be taken. A destructor shall not be static. A
5191   //   destructor can be invoked for a const, volatile or const
5192   //   volatile object. A destructor shall not be declared const,
5193   //   volatile or const volatile (9.3.2).
5194   if (SC == SC_Static) {
5195     if (!D.isInvalidType())
5196       Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
5197         << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5198         << SourceRange(D.getIdentifierLoc())
5199         << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
5200 
5201     SC = SC_None;
5202   }
5203   if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5204     // Destructors don't have return types, but the parser will
5205     // happily parse something like:
5206     //
5207     //   class X {
5208     //     float ~X();
5209     //   };
5210     //
5211     // The return type will be eliminated later.
5212     Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
5213       << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5214       << SourceRange(D.getIdentifierLoc());
5215   }
5216 
5217   DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
5218   if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
5219     if (FTI.TypeQuals & Qualifiers::Const)
5220       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5221         << "const" << SourceRange(D.getIdentifierLoc());
5222     if (FTI.TypeQuals & Qualifiers::Volatile)
5223       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5224         << "volatile" << SourceRange(D.getIdentifierLoc());
5225     if (FTI.TypeQuals & Qualifiers::Restrict)
5226       Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
5227         << "restrict" << SourceRange(D.getIdentifierLoc());
5228     D.setInvalidType();
5229   }
5230 
5231   // C++0x [class.dtor]p2:
5232   //   A destructor shall not be declared with a ref-qualifier.
5233   if (FTI.hasRefQualifier()) {
5234     Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
5235       << FTI.RefQualifierIsLValueRef
5236       << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
5237     D.setInvalidType();
5238   }
5239 
5240   // Make sure we don't have any parameters.
5241   if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
5242     Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
5243 
5244     // Delete the parameters.
5245     FTI.freeArgs();
5246     D.setInvalidType();
5247   }
5248 
5249   // Make sure the destructor isn't variadic.
5250   if (FTI.isVariadic) {
5251     Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
5252     D.setInvalidType();
5253   }
5254 
5255   // Rebuild the function type "R" without any type qualifiers or
5256   // parameters (in case any of the errors above fired) and with
5257   // "void" as the return type, since destructors don't have return
5258   // types.
5259   if (!D.isInvalidType())
5260     return R;
5261 
5262   const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5263   FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
5264   EPI.Variadic = false;
5265   EPI.TypeQuals = 0;
5266   EPI.RefQualifier = RQ_None;
5267   return Context.getFunctionType(Context.VoidTy, 0, 0, EPI);
5268 }
5269 
5270 /// CheckConversionDeclarator - Called by ActOnDeclarator to check the
5271 /// well-formednes of the conversion function declarator @p D with
5272 /// type @p R. If there are any errors in the declarator, this routine
5273 /// will emit diagnostics and return true. Otherwise, it will return
5274 /// false. Either way, the type @p R will be updated to reflect a
5275 /// well-formed type for the conversion operator.
CheckConversionDeclarator(Declarator & D,QualType & R,StorageClass & SC)5276 void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
5277                                      StorageClass& SC) {
5278   // C++ [class.conv.fct]p1:
5279   //   Neither parameter types nor return type can be specified. The
5280   //   type of a conversion function (8.3.5) is "function taking no
5281   //   parameter returning conversion-type-id."
5282   if (SC == SC_Static) {
5283     if (!D.isInvalidType())
5284       Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
5285         << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
5286         << SourceRange(D.getIdentifierLoc());
5287     D.setInvalidType();
5288     SC = SC_None;
5289   }
5290 
5291   QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId);
5292 
5293   if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
5294     // Conversion functions don't have return types, but the parser will
5295     // happily parse something like:
5296     //
5297     //   class X {
5298     //     float operator bool();
5299     //   };
5300     //
5301     // The return type will be changed later anyway.
5302     Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
5303       << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
5304       << SourceRange(D.getIdentifierLoc());
5305     D.setInvalidType();
5306   }
5307 
5308   const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
5309 
5310   // Make sure we don't have any parameters.
5311   if (Proto->getNumArgs() > 0) {
5312     Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
5313 
5314     // Delete the parameters.
5315     D.getFunctionTypeInfo().freeArgs();
5316     D.setInvalidType();
5317   } else if (Proto->isVariadic()) {
5318     Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
5319     D.setInvalidType();
5320   }
5321 
5322   // Diagnose "&operator bool()" and other such nonsense.  This
5323   // is actually a gcc extension which we don't support.
5324   if (Proto->getResultType() != ConvType) {
5325     Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
5326       << Proto->getResultType();
5327     D.setInvalidType();
5328     ConvType = Proto->getResultType();
5329   }
5330 
5331   // C++ [class.conv.fct]p4:
5332   //   The conversion-type-id shall not represent a function type nor
5333   //   an array type.
5334   if (ConvType->isArrayType()) {
5335     Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
5336     ConvType = Context.getPointerType(ConvType);
5337     D.setInvalidType();
5338   } else if (ConvType->isFunctionType()) {
5339     Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
5340     ConvType = Context.getPointerType(ConvType);
5341     D.setInvalidType();
5342   }
5343 
5344   // Rebuild the function type "R" without any parameters (in case any
5345   // of the errors above fired) and with the conversion type as the
5346   // return type.
5347   if (D.isInvalidType())
5348     R = Context.getFunctionType(ConvType, 0, 0, Proto->getExtProtoInfo());
5349 
5350   // C++0x explicit conversion operators.
5351   if (D.getDeclSpec().isExplicitSpecified())
5352     Diag(D.getDeclSpec().getExplicitSpecLoc(),
5353          getLangOpts().CPlusPlus0x ?
5354            diag::warn_cxx98_compat_explicit_conversion_functions :
5355            diag::ext_explicit_conversion_functions)
5356       << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
5357 }
5358 
5359 /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
5360 /// the declaration of the given C++ conversion function. This routine
5361 /// is responsible for recording the conversion function in the C++
5362 /// class, if possible.
ActOnConversionDeclarator(CXXConversionDecl * Conversion)5363 Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
5364   assert(Conversion && "Expected to receive a conversion function declaration");
5365 
5366   CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
5367 
5368   // Make sure we aren't redeclaring the conversion function.
5369   QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
5370 
5371   // C++ [class.conv.fct]p1:
5372   //   [...] A conversion function is never used to convert a
5373   //   (possibly cv-qualified) object to the (possibly cv-qualified)
5374   //   same object type (or a reference to it), to a (possibly
5375   //   cv-qualified) base class of that type (or a reference to it),
5376   //   or to (possibly cv-qualified) void.
5377   // FIXME: Suppress this warning if the conversion function ends up being a
5378   // virtual function that overrides a virtual function in a base class.
5379   QualType ClassType
5380     = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
5381   if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
5382     ConvType = ConvTypeRef->getPointeeType();
5383   if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
5384       Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
5385     /* Suppress diagnostics for instantiations. */;
5386   else if (ConvType->isRecordType()) {
5387     ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
5388     if (ConvType == ClassType)
5389       Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
5390         << ClassType;
5391     else if (IsDerivedFrom(ClassType, ConvType))
5392       Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
5393         <<  ClassType << ConvType;
5394   } else if (ConvType->isVoidType()) {
5395     Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
5396       << ClassType << ConvType;
5397   }
5398 
5399   if (FunctionTemplateDecl *ConversionTemplate
5400                                 = Conversion->getDescribedFunctionTemplate())
5401     return ConversionTemplate;
5402 
5403   return Conversion;
5404 }
5405 
5406 //===----------------------------------------------------------------------===//
5407 // Namespace Handling
5408 //===----------------------------------------------------------------------===//
5409 
5410 
5411 
5412 /// ActOnStartNamespaceDef - This is called at the start of a namespace
5413 /// definition.
ActOnStartNamespaceDef(Scope * NamespcScope,SourceLocation InlineLoc,SourceLocation NamespaceLoc,SourceLocation IdentLoc,IdentifierInfo * II,SourceLocation LBrace,AttributeList * AttrList)5414 Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
5415                                    SourceLocation InlineLoc,
5416                                    SourceLocation NamespaceLoc,
5417                                    SourceLocation IdentLoc,
5418                                    IdentifierInfo *II,
5419                                    SourceLocation LBrace,
5420                                    AttributeList *AttrList) {
5421   SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
5422   // For anonymous namespace, take the location of the left brace.
5423   SourceLocation Loc = II ? IdentLoc : LBrace;
5424   bool IsInline = InlineLoc.isValid();
5425   bool IsInvalid = false;
5426   bool IsStd = false;
5427   bool AddToKnown = false;
5428   Scope *DeclRegionScope = NamespcScope->getParent();
5429 
5430   NamespaceDecl *PrevNS = 0;
5431   if (II) {
5432     // C++ [namespace.def]p2:
5433     //   The identifier in an original-namespace-definition shall not
5434     //   have been previously defined in the declarative region in
5435     //   which the original-namespace-definition appears. The
5436     //   identifier in an original-namespace-definition is the name of
5437     //   the namespace. Subsequently in that declarative region, it is
5438     //   treated as an original-namespace-name.
5439     //
5440     // Since namespace names are unique in their scope, and we don't
5441     // look through using directives, just look for any ordinary names.
5442 
5443     const unsigned IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Member |
5444     Decl::IDNS_Type | Decl::IDNS_Using | Decl::IDNS_Tag |
5445     Decl::IDNS_Namespace;
5446     NamedDecl *PrevDecl = 0;
5447     for (DeclContext::lookup_result R
5448          = CurContext->getRedeclContext()->lookup(II);
5449          R.first != R.second; ++R.first) {
5450       if ((*R.first)->getIdentifierNamespace() & IDNS) {
5451         PrevDecl = *R.first;
5452         break;
5453       }
5454     }
5455 
5456     PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
5457 
5458     if (PrevNS) {
5459       // This is an extended namespace definition.
5460       if (IsInline != PrevNS->isInline()) {
5461         // inline-ness must match
5462         if (PrevNS->isInline()) {
5463           // The user probably just forgot the 'inline', so suggest that it
5464           // be added back.
5465           Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
5466             << FixItHint::CreateInsertion(NamespaceLoc, "inline ");
5467         } else {
5468           Diag(Loc, diag::err_inline_namespace_mismatch)
5469             << IsInline;
5470         }
5471         Diag(PrevNS->getLocation(), diag::note_previous_definition);
5472 
5473         IsInline = PrevNS->isInline();
5474       }
5475     } else if (PrevDecl) {
5476       // This is an invalid name redefinition.
5477       Diag(Loc, diag::err_redefinition_different_kind)
5478         << II;
5479       Diag(PrevDecl->getLocation(), diag::note_previous_definition);
5480       IsInvalid = true;
5481       // Continue on to push Namespc as current DeclContext and return it.
5482     } else if (II->isStr("std") &&
5483                CurContext->getRedeclContext()->isTranslationUnit()) {
5484       // This is the first "real" definition of the namespace "std", so update
5485       // our cache of the "std" namespace to point at this definition.
5486       PrevNS = getStdNamespace();
5487       IsStd = true;
5488       AddToKnown = !IsInline;
5489     } else {
5490       // We've seen this namespace for the first time.
5491       AddToKnown = !IsInline;
5492     }
5493   } else {
5494     // Anonymous namespaces.
5495 
5496     // Determine whether the parent already has an anonymous namespace.
5497     DeclContext *Parent = CurContext->getRedeclContext();
5498     if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5499       PrevNS = TU->getAnonymousNamespace();
5500     } else {
5501       NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
5502       PrevNS = ND->getAnonymousNamespace();
5503     }
5504 
5505     if (PrevNS && IsInline != PrevNS->isInline()) {
5506       // inline-ness must match
5507       Diag(Loc, diag::err_inline_namespace_mismatch)
5508         << IsInline;
5509       Diag(PrevNS->getLocation(), diag::note_previous_definition);
5510 
5511       // Recover by ignoring the new namespace's inline status.
5512       IsInline = PrevNS->isInline();
5513     }
5514   }
5515 
5516   NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
5517                                                  StartLoc, Loc, II, PrevNS);
5518   if (IsInvalid)
5519     Namespc->setInvalidDecl();
5520 
5521   ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
5522 
5523   // FIXME: Should we be merging attributes?
5524   if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
5525     PushNamespaceVisibilityAttr(Attr, Loc);
5526 
5527   if (IsStd)
5528     StdNamespace = Namespc;
5529   if (AddToKnown)
5530     KnownNamespaces[Namespc] = false;
5531 
5532   if (II) {
5533     PushOnScopeChains(Namespc, DeclRegionScope);
5534   } else {
5535     // Link the anonymous namespace into its parent.
5536     DeclContext *Parent = CurContext->getRedeclContext();
5537     if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
5538       TU->setAnonymousNamespace(Namespc);
5539     } else {
5540       cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
5541     }
5542 
5543     CurContext->addDecl(Namespc);
5544 
5545     // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
5546     //   behaves as if it were replaced by
5547     //     namespace unique { /* empty body */ }
5548     //     using namespace unique;
5549     //     namespace unique { namespace-body }
5550     //   where all occurrences of 'unique' in a translation unit are
5551     //   replaced by the same identifier and this identifier differs
5552     //   from all other identifiers in the entire program.
5553 
5554     // We just create the namespace with an empty name and then add an
5555     // implicit using declaration, just like the standard suggests.
5556     //
5557     // CodeGen enforces the "universally unique" aspect by giving all
5558     // declarations semantically contained within an anonymous
5559     // namespace internal linkage.
5560 
5561     if (!PrevNS) {
5562       UsingDirectiveDecl* UD
5563         = UsingDirectiveDecl::Create(Context, CurContext,
5564                                      /* 'using' */ LBrace,
5565                                      /* 'namespace' */ SourceLocation(),
5566                                      /* qualifier */ NestedNameSpecifierLoc(),
5567                                      /* identifier */ SourceLocation(),
5568                                      Namespc,
5569                                      /* Ancestor */ CurContext);
5570       UD->setImplicit();
5571       CurContext->addDecl(UD);
5572     }
5573   }
5574 
5575   // Although we could have an invalid decl (i.e. the namespace name is a
5576   // redefinition), push it as current DeclContext and try to continue parsing.
5577   // FIXME: We should be able to push Namespc here, so that the each DeclContext
5578   // for the namespace has the declarations that showed up in that particular
5579   // namespace definition.
5580   PushDeclContext(NamespcScope, Namespc);
5581   return Namespc;
5582 }
5583 
5584 /// getNamespaceDecl - Returns the namespace a decl represents. If the decl
5585 /// is a namespace alias, returns the namespace it points to.
getNamespaceDecl(NamedDecl * D)5586 static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
5587   if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
5588     return AD->getNamespace();
5589   return dyn_cast_or_null<NamespaceDecl>(D);
5590 }
5591 
5592 /// ActOnFinishNamespaceDef - This callback is called after a namespace is
5593 /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
ActOnFinishNamespaceDef(Decl * Dcl,SourceLocation RBrace)5594 void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
5595   NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
5596   assert(Namespc && "Invalid parameter, expected NamespaceDecl");
5597   Namespc->setRBraceLoc(RBrace);
5598   PopDeclContext();
5599   if (Namespc->hasAttr<VisibilityAttr>())
5600     PopPragmaVisibility(true, RBrace);
5601 }
5602 
getStdBadAlloc() const5603 CXXRecordDecl *Sema::getStdBadAlloc() const {
5604   return cast_or_null<CXXRecordDecl>(
5605                                   StdBadAlloc.get(Context.getExternalSource()));
5606 }
5607 
getStdNamespace() const5608 NamespaceDecl *Sema::getStdNamespace() const {
5609   return cast_or_null<NamespaceDecl>(
5610                                  StdNamespace.get(Context.getExternalSource()));
5611 }
5612 
5613 /// \brief Retrieve the special "std" namespace, which may require us to
5614 /// implicitly define the namespace.
getOrCreateStdNamespace()5615 NamespaceDecl *Sema::getOrCreateStdNamespace() {
5616   if (!StdNamespace) {
5617     // The "std" namespace has not yet been defined, so build one implicitly.
5618     StdNamespace = NamespaceDecl::Create(Context,
5619                                          Context.getTranslationUnitDecl(),
5620                                          /*Inline=*/false,
5621                                          SourceLocation(), SourceLocation(),
5622                                          &PP.getIdentifierTable().get("std"),
5623                                          /*PrevDecl=*/0);
5624     getStdNamespace()->setImplicit(true);
5625   }
5626 
5627   return getStdNamespace();
5628 }
5629 
isStdInitializerList(QualType Ty,QualType * Element)5630 bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
5631   assert(getLangOpts().CPlusPlus &&
5632          "Looking for std::initializer_list outside of C++.");
5633 
5634   // We're looking for implicit instantiations of
5635   // template <typename E> class std::initializer_list.
5636 
5637   if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
5638     return false;
5639 
5640   ClassTemplateDecl *Template = 0;
5641   const TemplateArgument *Arguments = 0;
5642 
5643   if (const RecordType *RT = Ty->getAs<RecordType>()) {
5644 
5645     ClassTemplateSpecializationDecl *Specialization =
5646         dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
5647     if (!Specialization)
5648       return false;
5649 
5650     Template = Specialization->getSpecializedTemplate();
5651     Arguments = Specialization->getTemplateArgs().data();
5652   } else if (const TemplateSpecializationType *TST =
5653                  Ty->getAs<TemplateSpecializationType>()) {
5654     Template = dyn_cast_or_null<ClassTemplateDecl>(
5655         TST->getTemplateName().getAsTemplateDecl());
5656     Arguments = TST->getArgs();
5657   }
5658   if (!Template)
5659     return false;
5660 
5661   if (!StdInitializerList) {
5662     // Haven't recognized std::initializer_list yet, maybe this is it.
5663     CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
5664     if (TemplateClass->getIdentifier() !=
5665             &PP.getIdentifierTable().get("initializer_list") ||
5666         !getStdNamespace()->InEnclosingNamespaceSetOf(
5667             TemplateClass->getDeclContext()))
5668       return false;
5669     // This is a template called std::initializer_list, but is it the right
5670     // template?
5671     TemplateParameterList *Params = Template->getTemplateParameters();
5672     if (Params->getMinRequiredArguments() != 1)
5673       return false;
5674     if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
5675       return false;
5676 
5677     // It's the right template.
5678     StdInitializerList = Template;
5679   }
5680 
5681   if (Template != StdInitializerList)
5682     return false;
5683 
5684   // This is an instance of std::initializer_list. Find the argument type.
5685   if (Element)
5686     *Element = Arguments[0].getAsType();
5687   return true;
5688 }
5689 
LookupStdInitializerList(Sema & S,SourceLocation Loc)5690 static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
5691   NamespaceDecl *Std = S.getStdNamespace();
5692   if (!Std) {
5693     S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5694     return 0;
5695   }
5696 
5697   LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
5698                       Loc, Sema::LookupOrdinaryName);
5699   if (!S.LookupQualifiedName(Result, Std)) {
5700     S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
5701     return 0;
5702   }
5703   ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
5704   if (!Template) {
5705     Result.suppressDiagnostics();
5706     // We found something weird. Complain about the first thing we found.
5707     NamedDecl *Found = *Result.begin();
5708     S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
5709     return 0;
5710   }
5711 
5712   // We found some template called std::initializer_list. Now verify that it's
5713   // correct.
5714   TemplateParameterList *Params = Template->getTemplateParameters();
5715   if (Params->getMinRequiredArguments() != 1 ||
5716       !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
5717     S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
5718     return 0;
5719   }
5720 
5721   return Template;
5722 }
5723 
BuildStdInitializerList(QualType Element,SourceLocation Loc)5724 QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
5725   if (!StdInitializerList) {
5726     StdInitializerList = LookupStdInitializerList(*this, Loc);
5727     if (!StdInitializerList)
5728       return QualType();
5729   }
5730 
5731   TemplateArgumentListInfo Args(Loc, Loc);
5732   Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
5733                                        Context.getTrivialTypeSourceInfo(Element,
5734                                                                         Loc)));
5735   return Context.getCanonicalType(
5736       CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
5737 }
5738 
isInitListConstructor(const CXXConstructorDecl * Ctor)5739 bool Sema::isInitListConstructor(const CXXConstructorDecl* Ctor) {
5740   // C++ [dcl.init.list]p2:
5741   //   A constructor is an initializer-list constructor if its first parameter
5742   //   is of type std::initializer_list<E> or reference to possibly cv-qualified
5743   //   std::initializer_list<E> for some type E, and either there are no other
5744   //   parameters or else all other parameters have default arguments.
5745   if (Ctor->getNumParams() < 1 ||
5746       (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg()))
5747     return false;
5748 
5749   QualType ArgType = Ctor->getParamDecl(0)->getType();
5750   if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
5751     ArgType = RT->getPointeeType().getUnqualifiedType();
5752 
5753   return isStdInitializerList(ArgType, 0);
5754 }
5755 
5756 /// \brief Determine whether a using statement is in a context where it will be
5757 /// apply in all contexts.
IsUsingDirectiveInToplevelContext(DeclContext * CurContext)5758 static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
5759   switch (CurContext->getDeclKind()) {
5760     case Decl::TranslationUnit:
5761       return true;
5762     case Decl::LinkageSpec:
5763       return IsUsingDirectiveInToplevelContext(CurContext->getParent());
5764     default:
5765       return false;
5766   }
5767 }
5768 
5769 namespace {
5770 
5771 // Callback to only accept typo corrections that are namespaces.
5772 class NamespaceValidatorCCC : public CorrectionCandidateCallback {
5773  public:
ValidateCandidate(const TypoCorrection & candidate)5774   virtual bool ValidateCandidate(const TypoCorrection &candidate) {
5775     if (NamedDecl *ND = candidate.getCorrectionDecl()) {
5776       return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
5777     }
5778     return false;
5779   }
5780 };
5781 
5782 }
5783 
TryNamespaceTypoCorrection(Sema & S,LookupResult & R,Scope * Sc,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * Ident)5784 static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
5785                                        CXXScopeSpec &SS,
5786                                        SourceLocation IdentLoc,
5787                                        IdentifierInfo *Ident) {
5788   NamespaceValidatorCCC Validator;
5789   R.clear();
5790   if (TypoCorrection Corrected = S.CorrectTypo(R.getLookupNameInfo(),
5791                                                R.getLookupKind(), Sc, &SS,
5792                                                Validator)) {
5793     std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
5794     std::string CorrectedQuotedStr(Corrected.getQuoted(S.getLangOpts()));
5795     if (DeclContext *DC = S.computeDeclContext(SS, false))
5796       S.Diag(IdentLoc, diag::err_using_directive_member_suggest)
5797         << Ident << DC << CorrectedQuotedStr << SS.getRange()
5798         << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5799     else
5800       S.Diag(IdentLoc, diag::err_using_directive_suggest)
5801         << Ident << CorrectedQuotedStr
5802         << FixItHint::CreateReplacement(IdentLoc, CorrectedStr);
5803 
5804     S.Diag(Corrected.getCorrectionDecl()->getLocation(),
5805          diag::note_namespace_defined_here) << CorrectedQuotedStr;
5806 
5807     R.addDecl(Corrected.getCorrectionDecl());
5808     return true;
5809   }
5810   return false;
5811 }
5812 
ActOnUsingDirective(Scope * S,SourceLocation UsingLoc,SourceLocation NamespcLoc,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * NamespcName,AttributeList * AttrList)5813 Decl *Sema::ActOnUsingDirective(Scope *S,
5814                                           SourceLocation UsingLoc,
5815                                           SourceLocation NamespcLoc,
5816                                           CXXScopeSpec &SS,
5817                                           SourceLocation IdentLoc,
5818                                           IdentifierInfo *NamespcName,
5819                                           AttributeList *AttrList) {
5820   assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
5821   assert(NamespcName && "Invalid NamespcName.");
5822   assert(IdentLoc.isValid() && "Invalid NamespceName location.");
5823 
5824   // This can only happen along a recovery path.
5825   while (S->getFlags() & Scope::TemplateParamScope)
5826     S = S->getParent();
5827   assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5828 
5829   UsingDirectiveDecl *UDir = 0;
5830   NestedNameSpecifier *Qualifier = 0;
5831   if (SS.isSet())
5832     Qualifier = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
5833 
5834   // Lookup namespace name.
5835   LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
5836   LookupParsedName(R, S, &SS);
5837   if (R.isAmbiguous())
5838     return 0;
5839 
5840   if (R.empty()) {
5841     R.clear();
5842     // Allow "using namespace std;" or "using namespace ::std;" even if
5843     // "std" hasn't been defined yet, for GCC compatibility.
5844     if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
5845         NamespcName->isStr("std")) {
5846       Diag(IdentLoc, diag::ext_using_undefined_std);
5847       R.addDecl(getOrCreateStdNamespace());
5848       R.resolveKind();
5849     }
5850     // Otherwise, attempt typo correction.
5851     else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
5852   }
5853 
5854   if (!R.empty()) {
5855     NamedDecl *Named = R.getFoundDecl();
5856     assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
5857         && "expected namespace decl");
5858     // C++ [namespace.udir]p1:
5859     //   A using-directive specifies that the names in the nominated
5860     //   namespace can be used in the scope in which the
5861     //   using-directive appears after the using-directive. During
5862     //   unqualified name lookup (3.4.1), the names appear as if they
5863     //   were declared in the nearest enclosing namespace which
5864     //   contains both the using-directive and the nominated
5865     //   namespace. [Note: in this context, "contains" means "contains
5866     //   directly or indirectly". ]
5867 
5868     // Find enclosing context containing both using-directive and
5869     // nominated namespace.
5870     NamespaceDecl *NS = getNamespaceDecl(Named);
5871     DeclContext *CommonAncestor = cast<DeclContext>(NS);
5872     while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
5873       CommonAncestor = CommonAncestor->getParent();
5874 
5875     UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
5876                                       SS.getWithLocInContext(Context),
5877                                       IdentLoc, Named, CommonAncestor);
5878 
5879     if (IsUsingDirectiveInToplevelContext(CurContext) &&
5880         !SourceMgr.isFromMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
5881       Diag(IdentLoc, diag::warn_using_directive_in_header);
5882     }
5883 
5884     PushUsingDirective(S, UDir);
5885   } else {
5886     Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
5887   }
5888 
5889   // FIXME: We ignore attributes for now.
5890   return UDir;
5891 }
5892 
PushUsingDirective(Scope * S,UsingDirectiveDecl * UDir)5893 void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
5894   // If the scope has an associated entity and the using directive is at
5895   // namespace or translation unit scope, add the UsingDirectiveDecl into
5896   // its lookup structure so qualified name lookup can find it.
5897   DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity());
5898   if (Ctx && !Ctx->isFunctionOrMethod())
5899     Ctx->addDecl(UDir);
5900   else
5901     // Otherwise, it is at block sope. The using-directives will affect lookup
5902     // only to the end of the scope.
5903     S->PushUsingDirective(UDir);
5904 }
5905 
5906 
ActOnUsingDeclaration(Scope * S,AccessSpecifier AS,bool HasUsingKeyword,SourceLocation UsingLoc,CXXScopeSpec & SS,UnqualifiedId & Name,AttributeList * AttrList,bool IsTypeName,SourceLocation TypenameLoc)5907 Decl *Sema::ActOnUsingDeclaration(Scope *S,
5908                                   AccessSpecifier AS,
5909                                   bool HasUsingKeyword,
5910                                   SourceLocation UsingLoc,
5911                                   CXXScopeSpec &SS,
5912                                   UnqualifiedId &Name,
5913                                   AttributeList *AttrList,
5914                                   bool IsTypeName,
5915                                   SourceLocation TypenameLoc) {
5916   assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
5917 
5918   switch (Name.getKind()) {
5919   case UnqualifiedId::IK_ImplicitSelfParam:
5920   case UnqualifiedId::IK_Identifier:
5921   case UnqualifiedId::IK_OperatorFunctionId:
5922   case UnqualifiedId::IK_LiteralOperatorId:
5923   case UnqualifiedId::IK_ConversionFunctionId:
5924     break;
5925 
5926   case UnqualifiedId::IK_ConstructorName:
5927   case UnqualifiedId::IK_ConstructorTemplateId:
5928     // C++0x inherited constructors.
5929     Diag(Name.getLocStart(),
5930          getLangOpts().CPlusPlus0x ?
5931            diag::warn_cxx98_compat_using_decl_constructor :
5932            diag::err_using_decl_constructor)
5933       << SS.getRange();
5934 
5935     if (getLangOpts().CPlusPlus0x) break;
5936 
5937     return 0;
5938 
5939   case UnqualifiedId::IK_DestructorName:
5940     Diag(Name.getLocStart(), diag::err_using_decl_destructor)
5941       << SS.getRange();
5942     return 0;
5943 
5944   case UnqualifiedId::IK_TemplateId:
5945     Diag(Name.getLocStart(), diag::err_using_decl_template_id)
5946       << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
5947     return 0;
5948   }
5949 
5950   DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
5951   DeclarationName TargetName = TargetNameInfo.getName();
5952   if (!TargetName)
5953     return 0;
5954 
5955   // Warn about using declarations.
5956   // TODO: store that the declaration was written without 'using' and
5957   // talk about access decls instead of using decls in the
5958   // diagnostics.
5959   if (!HasUsingKeyword) {
5960     UsingLoc = Name.getLocStart();
5961 
5962     Diag(UsingLoc, diag::warn_access_decl_deprecated)
5963       << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
5964   }
5965 
5966   if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
5967       DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
5968     return 0;
5969 
5970   NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS,
5971                                         TargetNameInfo, AttrList,
5972                                         /* IsInstantiation */ false,
5973                                         IsTypeName, TypenameLoc);
5974   if (UD)
5975     PushOnScopeChains(UD, S, /*AddToContext*/ false);
5976 
5977   return UD;
5978 }
5979 
5980 /// \brief Determine whether a using declaration considers the given
5981 /// declarations as "equivalent", e.g., if they are redeclarations of
5982 /// the same entity or are both typedefs of the same type.
5983 static bool
IsEquivalentForUsingDecl(ASTContext & Context,NamedDecl * D1,NamedDecl * D2,bool & SuppressRedeclaration)5984 IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2,
5985                          bool &SuppressRedeclaration) {
5986   if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) {
5987     SuppressRedeclaration = false;
5988     return true;
5989   }
5990 
5991   if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
5992     if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2)) {
5993       SuppressRedeclaration = true;
5994       return Context.hasSameType(TD1->getUnderlyingType(),
5995                                  TD2->getUnderlyingType());
5996     }
5997 
5998   return false;
5999 }
6000 
6001 
6002 /// Determines whether to create a using shadow decl for a particular
6003 /// decl, given the set of decls existing prior to this using lookup.
CheckUsingShadowDecl(UsingDecl * Using,NamedDecl * Orig,const LookupResult & Previous)6004 bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
6005                                 const LookupResult &Previous) {
6006   // Diagnose finding a decl which is not from a base class of the
6007   // current class.  We do this now because there are cases where this
6008   // function will silently decide not to build a shadow decl, which
6009   // will pre-empt further diagnostics.
6010   //
6011   // We don't need to do this in C++0x because we do the check once on
6012   // the qualifier.
6013   //
6014   // FIXME: diagnose the following if we care enough:
6015   //   struct A { int foo; };
6016   //   struct B : A { using A::foo; };
6017   //   template <class T> struct C : A {};
6018   //   template <class T> struct D : C<T> { using B::foo; } // <---
6019   // This is invalid (during instantiation) in C++03 because B::foo
6020   // resolves to the using decl in B, which is not a base class of D<T>.
6021   // We can't diagnose it immediately because C<T> is an unknown
6022   // specialization.  The UsingShadowDecl in D<T> then points directly
6023   // to A::foo, which will look well-formed when we instantiate.
6024   // The right solution is to not collapse the shadow-decl chain.
6025   if (!getLangOpts().CPlusPlus0x && CurContext->isRecord()) {
6026     DeclContext *OrigDC = Orig->getDeclContext();
6027 
6028     // Handle enums and anonymous structs.
6029     if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
6030     CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
6031     while (OrigRec->isAnonymousStructOrUnion())
6032       OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
6033 
6034     if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
6035       if (OrigDC == CurContext) {
6036         Diag(Using->getLocation(),
6037              diag::err_using_decl_nested_name_specifier_is_current_class)
6038           << Using->getQualifierLoc().getSourceRange();
6039         Diag(Orig->getLocation(), diag::note_using_decl_target);
6040         return true;
6041       }
6042 
6043       Diag(Using->getQualifierLoc().getBeginLoc(),
6044            diag::err_using_decl_nested_name_specifier_is_not_base_class)
6045         << Using->getQualifier()
6046         << cast<CXXRecordDecl>(CurContext)
6047         << Using->getQualifierLoc().getSourceRange();
6048       Diag(Orig->getLocation(), diag::note_using_decl_target);
6049       return true;
6050     }
6051   }
6052 
6053   if (Previous.empty()) return false;
6054 
6055   NamedDecl *Target = Orig;
6056   if (isa<UsingShadowDecl>(Target))
6057     Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
6058 
6059   // If the target happens to be one of the previous declarations, we
6060   // don't have a conflict.
6061   //
6062   // FIXME: but we might be increasing its access, in which case we
6063   // should redeclare it.
6064   NamedDecl *NonTag = 0, *Tag = 0;
6065   for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
6066          I != E; ++I) {
6067     NamedDecl *D = (*I)->getUnderlyingDecl();
6068     bool Result;
6069     if (IsEquivalentForUsingDecl(Context, D, Target, Result))
6070       return Result;
6071 
6072     (isa<TagDecl>(D) ? Tag : NonTag) = D;
6073   }
6074 
6075   if (Target->isFunctionOrFunctionTemplate()) {
6076     FunctionDecl *FD;
6077     if (isa<FunctionTemplateDecl>(Target))
6078       FD = cast<FunctionTemplateDecl>(Target)->getTemplatedDecl();
6079     else
6080       FD = cast<FunctionDecl>(Target);
6081 
6082     NamedDecl *OldDecl = 0;
6083     switch (CheckOverload(0, FD, Previous, OldDecl, /*IsForUsingDecl*/ true)) {
6084     case Ovl_Overload:
6085       return false;
6086 
6087     case Ovl_NonFunction:
6088       Diag(Using->getLocation(), diag::err_using_decl_conflict);
6089       break;
6090 
6091     // We found a decl with the exact signature.
6092     case Ovl_Match:
6093       // If we're in a record, we want to hide the target, so we
6094       // return true (without a diagnostic) to tell the caller not to
6095       // build a shadow decl.
6096       if (CurContext->isRecord())
6097         return true;
6098 
6099       // If we're not in a record, this is an error.
6100       Diag(Using->getLocation(), diag::err_using_decl_conflict);
6101       break;
6102     }
6103 
6104     Diag(Target->getLocation(), diag::note_using_decl_target);
6105     Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
6106     return true;
6107   }
6108 
6109   // Target is not a function.
6110 
6111   if (isa<TagDecl>(Target)) {
6112     // No conflict between a tag and a non-tag.
6113     if (!Tag) return false;
6114 
6115     Diag(Using->getLocation(), diag::err_using_decl_conflict);
6116     Diag(Target->getLocation(), diag::note_using_decl_target);
6117     Diag(Tag->getLocation(), diag::note_using_decl_conflict);
6118     return true;
6119   }
6120 
6121   // No conflict between a tag and a non-tag.
6122   if (!NonTag) return false;
6123 
6124   Diag(Using->getLocation(), diag::err_using_decl_conflict);
6125   Diag(Target->getLocation(), diag::note_using_decl_target);
6126   Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
6127   return true;
6128 }
6129 
6130 /// Builds a shadow declaration corresponding to a 'using' declaration.
BuildUsingShadowDecl(Scope * S,UsingDecl * UD,NamedDecl * Orig)6131 UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
6132                                             UsingDecl *UD,
6133                                             NamedDecl *Orig) {
6134 
6135   // If we resolved to another shadow declaration, just coalesce them.
6136   NamedDecl *Target = Orig;
6137   if (isa<UsingShadowDecl>(Target)) {
6138     Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
6139     assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
6140   }
6141 
6142   UsingShadowDecl *Shadow
6143     = UsingShadowDecl::Create(Context, CurContext,
6144                               UD->getLocation(), UD, Target);
6145   UD->addShadowDecl(Shadow);
6146 
6147   Shadow->setAccess(UD->getAccess());
6148   if (Orig->isInvalidDecl() || UD->isInvalidDecl())
6149     Shadow->setInvalidDecl();
6150 
6151   if (S)
6152     PushOnScopeChains(Shadow, S);
6153   else
6154     CurContext->addDecl(Shadow);
6155 
6156 
6157   return Shadow;
6158 }
6159 
6160 /// Hides a using shadow declaration.  This is required by the current
6161 /// using-decl implementation when a resolvable using declaration in a
6162 /// class is followed by a declaration which would hide or override
6163 /// one or more of the using decl's targets; for example:
6164 ///
6165 ///   struct Base { void foo(int); };
6166 ///   struct Derived : Base {
6167 ///     using Base::foo;
6168 ///     void foo(int);
6169 ///   };
6170 ///
6171 /// The governing language is C++03 [namespace.udecl]p12:
6172 ///
6173 ///   When a using-declaration brings names from a base class into a
6174 ///   derived class scope, member functions in the derived class
6175 ///   override and/or hide member functions with the same name and
6176 ///   parameter types in a base class (rather than conflicting).
6177 ///
6178 /// There are two ways to implement this:
6179 ///   (1) optimistically create shadow decls when they're not hidden
6180 ///       by existing declarations, or
6181 ///   (2) don't create any shadow decls (or at least don't make them
6182 ///       visible) until we've fully parsed/instantiated the class.
6183 /// The problem with (1) is that we might have to retroactively remove
6184 /// a shadow decl, which requires several O(n) operations because the
6185 /// decl structures are (very reasonably) not designed for removal.
6186 /// (2) avoids this but is very fiddly and phase-dependent.
HideUsingShadowDecl(Scope * S,UsingShadowDecl * Shadow)6187 void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
6188   if (Shadow->getDeclName().getNameKind() ==
6189         DeclarationName::CXXConversionFunctionName)
6190     cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
6191 
6192   // Remove it from the DeclContext...
6193   Shadow->getDeclContext()->removeDecl(Shadow);
6194 
6195   // ...and the scope, if applicable...
6196   if (S) {
6197     S->RemoveDecl(Shadow);
6198     IdResolver.RemoveDecl(Shadow);
6199   }
6200 
6201   // ...and the using decl.
6202   Shadow->getUsingDecl()->removeShadowDecl(Shadow);
6203 
6204   // TODO: complain somehow if Shadow was used.  It shouldn't
6205   // be possible for this to happen, because...?
6206 }
6207 
6208 /// Builds a using declaration.
6209 ///
6210 /// \param IsInstantiation - Whether this call arises from an
6211 ///   instantiation of an unresolved using declaration.  We treat
6212 ///   the lookup differently for these declarations.
BuildUsingDeclaration(Scope * S,AccessSpecifier AS,SourceLocation UsingLoc,CXXScopeSpec & SS,const DeclarationNameInfo & NameInfo,AttributeList * AttrList,bool IsInstantiation,bool IsTypeName,SourceLocation TypenameLoc)6213 NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
6214                                        SourceLocation UsingLoc,
6215                                        CXXScopeSpec &SS,
6216                                        const DeclarationNameInfo &NameInfo,
6217                                        AttributeList *AttrList,
6218                                        bool IsInstantiation,
6219                                        bool IsTypeName,
6220                                        SourceLocation TypenameLoc) {
6221   assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
6222   SourceLocation IdentLoc = NameInfo.getLoc();
6223   assert(IdentLoc.isValid() && "Invalid TargetName location.");
6224 
6225   // FIXME: We ignore attributes for now.
6226 
6227   if (SS.isEmpty()) {
6228     Diag(IdentLoc, diag::err_using_requires_qualname);
6229     return 0;
6230   }
6231 
6232   // Do the redeclaration lookup in the current scope.
6233   LookupResult Previous(*this, NameInfo, LookupUsingDeclName,
6234                         ForRedeclaration);
6235   Previous.setHideTags(false);
6236   if (S) {
6237     LookupName(Previous, S);
6238 
6239     // It is really dumb that we have to do this.
6240     LookupResult::Filter F = Previous.makeFilter();
6241     while (F.hasNext()) {
6242       NamedDecl *D = F.next();
6243       if (!isDeclInScope(D, CurContext, S))
6244         F.erase();
6245     }
6246     F.done();
6247   } else {
6248     assert(IsInstantiation && "no scope in non-instantiation");
6249     assert(CurContext->isRecord() && "scope not record in instantiation");
6250     LookupQualifiedName(Previous, CurContext);
6251   }
6252 
6253   // Check for invalid redeclarations.
6254   if (CheckUsingDeclRedeclaration(UsingLoc, IsTypeName, SS, IdentLoc, Previous))
6255     return 0;
6256 
6257   // Check for bad qualifiers.
6258   if (CheckUsingDeclQualifier(UsingLoc, SS, IdentLoc))
6259     return 0;
6260 
6261   DeclContext *LookupContext = computeDeclContext(SS);
6262   NamedDecl *D;
6263   NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
6264   if (!LookupContext) {
6265     if (IsTypeName) {
6266       // FIXME: not all declaration name kinds are legal here
6267       D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
6268                                               UsingLoc, TypenameLoc,
6269                                               QualifierLoc,
6270                                               IdentLoc, NameInfo.getName());
6271     } else {
6272       D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
6273                                            QualifierLoc, NameInfo);
6274     }
6275   } else {
6276     D = UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
6277                           NameInfo, IsTypeName);
6278   }
6279   D->setAccess(AS);
6280   CurContext->addDecl(D);
6281 
6282   if (!LookupContext) return D;
6283   UsingDecl *UD = cast<UsingDecl>(D);
6284 
6285   if (RequireCompleteDeclContext(SS, LookupContext)) {
6286     UD->setInvalidDecl();
6287     return UD;
6288   }
6289 
6290   // The normal rules do not apply to inheriting constructor declarations.
6291   if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) {
6292     if (CheckInheritingConstructorUsingDecl(UD))
6293       UD->setInvalidDecl();
6294     return UD;
6295   }
6296 
6297   // Otherwise, look up the target name.
6298 
6299   LookupResult R(*this, NameInfo, LookupOrdinaryName);
6300 
6301   // Unlike most lookups, we don't always want to hide tag
6302   // declarations: tag names are visible through the using declaration
6303   // even if hidden by ordinary names, *except* in a dependent context
6304   // where it's important for the sanity of two-phase lookup.
6305   if (!IsInstantiation)
6306     R.setHideTags(false);
6307 
6308   // For the purposes of this lookup, we have a base object type
6309   // equal to that of the current context.
6310   if (CurContext->isRecord()) {
6311     R.setBaseObjectType(
6312                    Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
6313   }
6314 
6315   LookupQualifiedName(R, LookupContext);
6316 
6317   if (R.empty()) {
6318     Diag(IdentLoc, diag::err_no_member)
6319       << NameInfo.getName() << LookupContext << SS.getRange();
6320     UD->setInvalidDecl();
6321     return UD;
6322   }
6323 
6324   if (R.isAmbiguous()) {
6325     UD->setInvalidDecl();
6326     return UD;
6327   }
6328 
6329   if (IsTypeName) {
6330     // If we asked for a typename and got a non-type decl, error out.
6331     if (!R.getAsSingle<TypeDecl>()) {
6332       Diag(IdentLoc, diag::err_using_typename_non_type);
6333       for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
6334         Diag((*I)->getUnderlyingDecl()->getLocation(),
6335              diag::note_using_decl_target);
6336       UD->setInvalidDecl();
6337       return UD;
6338     }
6339   } else {
6340     // If we asked for a non-typename and we got a type, error out,
6341     // but only if this is an instantiation of an unresolved using
6342     // decl.  Otherwise just silently find the type name.
6343     if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
6344       Diag(IdentLoc, diag::err_using_dependent_value_is_type);
6345       Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
6346       UD->setInvalidDecl();
6347       return UD;
6348     }
6349   }
6350 
6351   // C++0x N2914 [namespace.udecl]p6:
6352   // A using-declaration shall not name a namespace.
6353   if (R.getAsSingle<NamespaceDecl>()) {
6354     Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
6355       << SS.getRange();
6356     UD->setInvalidDecl();
6357     return UD;
6358   }
6359 
6360   for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
6361     if (!CheckUsingShadowDecl(UD, *I, Previous))
6362       BuildUsingShadowDecl(S, UD, *I);
6363   }
6364 
6365   return UD;
6366 }
6367 
6368 /// Additional checks for a using declaration referring to a constructor name.
CheckInheritingConstructorUsingDecl(UsingDecl * UD)6369 bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
6370   assert(!UD->isTypeName() && "expecting a constructor name");
6371 
6372   const Type *SourceType = UD->getQualifier()->getAsType();
6373   assert(SourceType &&
6374          "Using decl naming constructor doesn't have type in scope spec.");
6375   CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
6376 
6377   // Check whether the named type is a direct base class.
6378   CanQualType CanonicalSourceType = SourceType->getCanonicalTypeUnqualified();
6379   CXXRecordDecl::base_class_iterator BaseIt, BaseE;
6380   for (BaseIt = TargetClass->bases_begin(), BaseE = TargetClass->bases_end();
6381        BaseIt != BaseE; ++BaseIt) {
6382     CanQualType BaseType = BaseIt->getType()->getCanonicalTypeUnqualified();
6383     if (CanonicalSourceType == BaseType)
6384       break;
6385     if (BaseIt->getType()->isDependentType())
6386       break;
6387   }
6388 
6389   if (BaseIt == BaseE) {
6390     // Did not find SourceType in the bases.
6391     Diag(UD->getUsingLocation(),
6392          diag::err_using_decl_constructor_not_in_direct_base)
6393       << UD->getNameInfo().getSourceRange()
6394       << QualType(SourceType, 0) << TargetClass;
6395     return true;
6396   }
6397 
6398   if (!CurContext->isDependentContext())
6399     BaseIt->setInheritConstructors();
6400 
6401   return false;
6402 }
6403 
6404 /// Checks that the given using declaration is not an invalid
6405 /// redeclaration.  Note that this is checking only for the using decl
6406 /// itself, not for any ill-formedness among the UsingShadowDecls.
CheckUsingDeclRedeclaration(SourceLocation UsingLoc,bool isTypeName,const CXXScopeSpec & SS,SourceLocation NameLoc,const LookupResult & Prev)6407 bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
6408                                        bool isTypeName,
6409                                        const CXXScopeSpec &SS,
6410                                        SourceLocation NameLoc,
6411                                        const LookupResult &Prev) {
6412   // C++03 [namespace.udecl]p8:
6413   // C++0x [namespace.udecl]p10:
6414   //   A using-declaration is a declaration and can therefore be used
6415   //   repeatedly where (and only where) multiple declarations are
6416   //   allowed.
6417   //
6418   // That's in non-member contexts.
6419   if (!CurContext->getRedeclContext()->isRecord())
6420     return false;
6421 
6422   NestedNameSpecifier *Qual
6423     = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
6424 
6425   for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
6426     NamedDecl *D = *I;
6427 
6428     bool DTypename;
6429     NestedNameSpecifier *DQual;
6430     if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
6431       DTypename = UD->isTypeName();
6432       DQual = UD->getQualifier();
6433     } else if (UnresolvedUsingValueDecl *UD
6434                  = dyn_cast<UnresolvedUsingValueDecl>(D)) {
6435       DTypename = false;
6436       DQual = UD->getQualifier();
6437     } else if (UnresolvedUsingTypenameDecl *UD
6438                  = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
6439       DTypename = true;
6440       DQual = UD->getQualifier();
6441     } else continue;
6442 
6443     // using decls differ if one says 'typename' and the other doesn't.
6444     // FIXME: non-dependent using decls?
6445     if (isTypeName != DTypename) continue;
6446 
6447     // using decls differ if they name different scopes (but note that
6448     // template instantiation can cause this check to trigger when it
6449     // didn't before instantiation).
6450     if (Context.getCanonicalNestedNameSpecifier(Qual) !=
6451         Context.getCanonicalNestedNameSpecifier(DQual))
6452       continue;
6453 
6454     Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
6455     Diag(D->getLocation(), diag::note_using_decl) << 1;
6456     return true;
6457   }
6458 
6459   return false;
6460 }
6461 
6462 
6463 /// Checks that the given nested-name qualifier used in a using decl
6464 /// in the current context is appropriately related to the current
6465 /// scope.  If an error is found, diagnoses it and returns true.
CheckUsingDeclQualifier(SourceLocation UsingLoc,const CXXScopeSpec & SS,SourceLocation NameLoc)6466 bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
6467                                    const CXXScopeSpec &SS,
6468                                    SourceLocation NameLoc) {
6469   DeclContext *NamedContext = computeDeclContext(SS);
6470 
6471   if (!CurContext->isRecord()) {
6472     // C++03 [namespace.udecl]p3:
6473     // C++0x [namespace.udecl]p8:
6474     //   A using-declaration for a class member shall be a member-declaration.
6475 
6476     // If we weren't able to compute a valid scope, it must be a
6477     // dependent class scope.
6478     if (!NamedContext || NamedContext->isRecord()) {
6479       Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
6480         << SS.getRange();
6481       return true;
6482     }
6483 
6484     // Otherwise, everything is known to be fine.
6485     return false;
6486   }
6487 
6488   // The current scope is a record.
6489 
6490   // If the named context is dependent, we can't decide much.
6491   if (!NamedContext) {
6492     // FIXME: in C++0x, we can diagnose if we can prove that the
6493     // nested-name-specifier does not refer to a base class, which is
6494     // still possible in some cases.
6495 
6496     // Otherwise we have to conservatively report that things might be
6497     // okay.
6498     return false;
6499   }
6500 
6501   if (!NamedContext->isRecord()) {
6502     // Ideally this would point at the last name in the specifier,
6503     // but we don't have that level of source info.
6504     Diag(SS.getRange().getBegin(),
6505          diag::err_using_decl_nested_name_specifier_is_not_class)
6506       << (NestedNameSpecifier*) SS.getScopeRep() << SS.getRange();
6507     return true;
6508   }
6509 
6510   if (!NamedContext->isDependentContext() &&
6511       RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
6512     return true;
6513 
6514   if (getLangOpts().CPlusPlus0x) {
6515     // C++0x [namespace.udecl]p3:
6516     //   In a using-declaration used as a member-declaration, the
6517     //   nested-name-specifier shall name a base class of the class
6518     //   being defined.
6519 
6520     if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
6521                                  cast<CXXRecordDecl>(NamedContext))) {
6522       if (CurContext == NamedContext) {
6523         Diag(NameLoc,
6524              diag::err_using_decl_nested_name_specifier_is_current_class)
6525           << SS.getRange();
6526         return true;
6527       }
6528 
6529       Diag(SS.getRange().getBegin(),
6530            diag::err_using_decl_nested_name_specifier_is_not_base_class)
6531         << (NestedNameSpecifier*) SS.getScopeRep()
6532         << cast<CXXRecordDecl>(CurContext)
6533         << SS.getRange();
6534       return true;
6535     }
6536 
6537     return false;
6538   }
6539 
6540   // C++03 [namespace.udecl]p4:
6541   //   A using-declaration used as a member-declaration shall refer
6542   //   to a member of a base class of the class being defined [etc.].
6543 
6544   // Salient point: SS doesn't have to name a base class as long as
6545   // lookup only finds members from base classes.  Therefore we can
6546   // diagnose here only if we can prove that that can't happen,
6547   // i.e. if the class hierarchies provably don't intersect.
6548 
6549   // TODO: it would be nice if "definitely valid" results were cached
6550   // in the UsingDecl and UsingShadowDecl so that these checks didn't
6551   // need to be repeated.
6552 
6553   struct UserData {
6554     llvm::SmallPtrSet<const CXXRecordDecl*, 4> Bases;
6555 
6556     static bool collect(const CXXRecordDecl *Base, void *OpaqueData) {
6557       UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6558       Data->Bases.insert(Base);
6559       return true;
6560     }
6561 
6562     bool hasDependentBases(const CXXRecordDecl *Class) {
6563       return !Class->forallBases(collect, this);
6564     }
6565 
6566     /// Returns true if the base is dependent or is one of the
6567     /// accumulated base classes.
6568     static bool doesNotContain(const CXXRecordDecl *Base, void *OpaqueData) {
6569       UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
6570       return !Data->Bases.count(Base);
6571     }
6572 
6573     bool mightShareBases(const CXXRecordDecl *Class) {
6574       return Bases.count(Class) || !Class->forallBases(doesNotContain, this);
6575     }
6576   };
6577 
6578   UserData Data;
6579 
6580   // Returns false if we find a dependent base.
6581   if (Data.hasDependentBases(cast<CXXRecordDecl>(CurContext)))
6582     return false;
6583 
6584   // Returns false if the class has a dependent base or if it or one
6585   // of its bases is present in the base set of the current context.
6586   if (Data.mightShareBases(cast<CXXRecordDecl>(NamedContext)))
6587     return false;
6588 
6589   Diag(SS.getRange().getBegin(),
6590        diag::err_using_decl_nested_name_specifier_is_not_base_class)
6591     << (NestedNameSpecifier*) SS.getScopeRep()
6592     << cast<CXXRecordDecl>(CurContext)
6593     << SS.getRange();
6594 
6595   return true;
6596 }
6597 
ActOnAliasDeclaration(Scope * S,AccessSpecifier AS,MultiTemplateParamsArg TemplateParamLists,SourceLocation UsingLoc,UnqualifiedId & Name,TypeResult Type)6598 Decl *Sema::ActOnAliasDeclaration(Scope *S,
6599                                   AccessSpecifier AS,
6600                                   MultiTemplateParamsArg TemplateParamLists,
6601                                   SourceLocation UsingLoc,
6602                                   UnqualifiedId &Name,
6603                                   TypeResult Type) {
6604   // Skip up to the relevant declaration scope.
6605   while (S->getFlags() & Scope::TemplateParamScope)
6606     S = S->getParent();
6607   assert((S->getFlags() & Scope::DeclScope) &&
6608          "got alias-declaration outside of declaration scope");
6609 
6610   if (Type.isInvalid())
6611     return 0;
6612 
6613   bool Invalid = false;
6614   DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
6615   TypeSourceInfo *TInfo = 0;
6616   GetTypeFromParser(Type.get(), &TInfo);
6617 
6618   if (DiagnoseClassNameShadow(CurContext, NameInfo))
6619     return 0;
6620 
6621   if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
6622                                       UPPC_DeclarationType)) {
6623     Invalid = true;
6624     TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
6625                                              TInfo->getTypeLoc().getBeginLoc());
6626   }
6627 
6628   LookupResult Previous(*this, NameInfo, LookupOrdinaryName, ForRedeclaration);
6629   LookupName(Previous, S);
6630 
6631   // Warn about shadowing the name of a template parameter.
6632   if (Previous.isSingleResult() &&
6633       Previous.getFoundDecl()->isTemplateParameter()) {
6634     DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
6635     Previous.clear();
6636   }
6637 
6638   assert(Name.Kind == UnqualifiedId::IK_Identifier &&
6639          "name in alias declaration must be an identifier");
6640   TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
6641                                                Name.StartLocation,
6642                                                Name.Identifier, TInfo);
6643 
6644   NewTD->setAccess(AS);
6645 
6646   if (Invalid)
6647     NewTD->setInvalidDecl();
6648 
6649   CheckTypedefForVariablyModifiedType(S, NewTD);
6650   Invalid |= NewTD->isInvalidDecl();
6651 
6652   bool Redeclaration = false;
6653 
6654   NamedDecl *NewND;
6655   if (TemplateParamLists.size()) {
6656     TypeAliasTemplateDecl *OldDecl = 0;
6657     TemplateParameterList *OldTemplateParams = 0;
6658 
6659     if (TemplateParamLists.size() != 1) {
6660       Diag(UsingLoc, diag::err_alias_template_extra_headers)
6661         << SourceRange(TemplateParamLists.get()[1]->getTemplateLoc(),
6662          TemplateParamLists.get()[TemplateParamLists.size()-1]->getRAngleLoc());
6663     }
6664     TemplateParameterList *TemplateParams = TemplateParamLists.get()[0];
6665 
6666     // Only consider previous declarations in the same scope.
6667     FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
6668                          /*ExplicitInstantiationOrSpecialization*/false);
6669     if (!Previous.empty()) {
6670       Redeclaration = true;
6671 
6672       OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
6673       if (!OldDecl && !Invalid) {
6674         Diag(UsingLoc, diag::err_redefinition_different_kind)
6675           << Name.Identifier;
6676 
6677         NamedDecl *OldD = Previous.getRepresentativeDecl();
6678         if (OldD->getLocation().isValid())
6679           Diag(OldD->getLocation(), diag::note_previous_definition);
6680 
6681         Invalid = true;
6682       }
6683 
6684       if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
6685         if (TemplateParameterListsAreEqual(TemplateParams,
6686                                            OldDecl->getTemplateParameters(),
6687                                            /*Complain=*/true,
6688                                            TPL_TemplateMatch))
6689           OldTemplateParams = OldDecl->getTemplateParameters();
6690         else
6691           Invalid = true;
6692 
6693         TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
6694         if (!Invalid &&
6695             !Context.hasSameType(OldTD->getUnderlyingType(),
6696                                  NewTD->getUnderlyingType())) {
6697           // FIXME: The C++0x standard does not clearly say this is ill-formed,
6698           // but we can't reasonably accept it.
6699           Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
6700             << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
6701           if (OldTD->getLocation().isValid())
6702             Diag(OldTD->getLocation(), diag::note_previous_definition);
6703           Invalid = true;
6704         }
6705       }
6706     }
6707 
6708     // Merge any previous default template arguments into our parameters,
6709     // and check the parameter list.
6710     if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
6711                                    TPC_TypeAliasTemplate))
6712       return 0;
6713 
6714     TypeAliasTemplateDecl *NewDecl =
6715       TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
6716                                     Name.Identifier, TemplateParams,
6717                                     NewTD);
6718 
6719     NewDecl->setAccess(AS);
6720 
6721     if (Invalid)
6722       NewDecl->setInvalidDecl();
6723     else if (OldDecl)
6724       NewDecl->setPreviousDeclaration(OldDecl);
6725 
6726     NewND = NewDecl;
6727   } else {
6728     ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
6729     NewND = NewTD;
6730   }
6731 
6732   if (!Redeclaration)
6733     PushOnScopeChains(NewND, S);
6734 
6735   return NewND;
6736 }
6737 
ActOnNamespaceAliasDef(Scope * S,SourceLocation NamespaceLoc,SourceLocation AliasLoc,IdentifierInfo * Alias,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * Ident)6738 Decl *Sema::ActOnNamespaceAliasDef(Scope *S,
6739                                              SourceLocation NamespaceLoc,
6740                                              SourceLocation AliasLoc,
6741                                              IdentifierInfo *Alias,
6742                                              CXXScopeSpec &SS,
6743                                              SourceLocation IdentLoc,
6744                                              IdentifierInfo *Ident) {
6745 
6746   // Lookup the namespace name.
6747   LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
6748   LookupParsedName(R, S, &SS);
6749 
6750   // Check if we have a previous declaration with the same name.
6751   NamedDecl *PrevDecl
6752     = LookupSingleName(S, Alias, AliasLoc, LookupOrdinaryName,
6753                        ForRedeclaration);
6754   if (PrevDecl && !isDeclInScope(PrevDecl, CurContext, S))
6755     PrevDecl = 0;
6756 
6757   if (PrevDecl) {
6758     if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
6759       // We already have an alias with the same name that points to the same
6760       // namespace, so don't create a new one.
6761       // FIXME: At some point, we'll want to create the (redundant)
6762       // declaration to maintain better source information.
6763       if (!R.isAmbiguous() && !R.empty() &&
6764           AD->getNamespace()->Equals(getNamespaceDecl(R.getFoundDecl())))
6765         return 0;
6766     }
6767 
6768     unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
6769       diag::err_redefinition_different_kind;
6770     Diag(AliasLoc, DiagID) << Alias;
6771     Diag(PrevDecl->getLocation(), diag::note_previous_definition);
6772     return 0;
6773   }
6774 
6775   if (R.isAmbiguous())
6776     return 0;
6777 
6778   if (R.empty()) {
6779     if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
6780       Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
6781       return 0;
6782     }
6783   }
6784 
6785   NamespaceAliasDecl *AliasDecl =
6786     NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
6787                                Alias, SS.getWithLocInContext(Context),
6788                                IdentLoc, R.getFoundDecl());
6789 
6790   PushOnScopeChains(AliasDecl, S);
6791   return AliasDecl;
6792 }
6793 
6794 namespace {
6795   /// \brief Scoped object used to handle the state changes required in Sema
6796   /// to implicitly define the body of a C++ member function;
6797   class ImplicitlyDefinedFunctionScope {
6798     Sema &S;
6799     Sema::ContextRAII SavedContext;
6800 
6801   public:
ImplicitlyDefinedFunctionScope(Sema & S,CXXMethodDecl * Method)6802     ImplicitlyDefinedFunctionScope(Sema &S, CXXMethodDecl *Method)
6803       : S(S), SavedContext(S, Method)
6804     {
6805       S.PushFunctionScope();
6806       S.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated);
6807     }
6808 
~ImplicitlyDefinedFunctionScope()6809     ~ImplicitlyDefinedFunctionScope() {
6810       S.PopExpressionEvaluationContext();
6811       S.PopFunctionScopeInfo();
6812     }
6813   };
6814 }
6815 
6816 Sema::ImplicitExceptionSpecification
ComputeDefaultedDefaultCtorExceptionSpec(CXXRecordDecl * ClassDecl)6817 Sema::ComputeDefaultedDefaultCtorExceptionSpec(CXXRecordDecl *ClassDecl) {
6818   // C++ [except.spec]p14:
6819   //   An implicitly declared special member function (Clause 12) shall have an
6820   //   exception-specification. [...]
6821   ImplicitExceptionSpecification ExceptSpec(*this);
6822   if (ClassDecl->isInvalidDecl())
6823     return ExceptSpec;
6824 
6825   // Direct base-class constructors.
6826   for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
6827                                        BEnd = ClassDecl->bases_end();
6828        B != BEnd; ++B) {
6829     if (B->isVirtual()) // Handled below.
6830       continue;
6831 
6832     if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6833       CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6834       CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6835       // If this is a deleted function, add it anyway. This might be conformant
6836       // with the standard. This might not. I'm not sure. It might not matter.
6837       if (Constructor)
6838         ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6839     }
6840   }
6841 
6842   // Virtual base-class constructors.
6843   for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
6844                                        BEnd = ClassDecl->vbases_end();
6845        B != BEnd; ++B) {
6846     if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
6847       CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6848       CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl);
6849       // If this is a deleted function, add it anyway. This might be conformant
6850       // with the standard. This might not. I'm not sure. It might not matter.
6851       if (Constructor)
6852         ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
6853     }
6854   }
6855 
6856   // Field constructors.
6857   for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
6858                                FEnd = ClassDecl->field_end();
6859        F != FEnd; ++F) {
6860     if (F->hasInClassInitializer()) {
6861       if (Expr *E = F->getInClassInitializer())
6862         ExceptSpec.CalledExpr(E);
6863       else if (!F->isInvalidDecl())
6864         ExceptSpec.SetDelayed();
6865     } else if (const RecordType *RecordTy
6866               = Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
6867       CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
6868       CXXConstructorDecl *Constructor = LookupDefaultConstructor(FieldRecDecl);
6869       // If this is a deleted function, add it anyway. This might be conformant
6870       // with the standard. This might not. I'm not sure. It might not matter.
6871       // In particular, the problem is that this function never gets called. It
6872       // might just be ill-formed because this function attempts to refer to
6873       // a deleted function here.
6874       if (Constructor)
6875         ExceptSpec.CalledDecl(F->getLocation(), Constructor);
6876     }
6877   }
6878 
6879   return ExceptSpec;
6880 }
6881 
DeclareImplicitDefaultConstructor(CXXRecordDecl * ClassDecl)6882 CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
6883                                                      CXXRecordDecl *ClassDecl) {
6884   // C++ [class.ctor]p5:
6885   //   A default constructor for a class X is a constructor of class X
6886   //   that can be called without an argument. If there is no
6887   //   user-declared constructor for class X, a default constructor is
6888   //   implicitly declared. An implicitly-declared default constructor
6889   //   is an inline public member of its class.
6890   assert(!ClassDecl->hasUserDeclaredConstructor() &&
6891          "Should not build implicit default constructor!");
6892 
6893   ImplicitExceptionSpecification Spec =
6894     ComputeDefaultedDefaultCtorExceptionSpec(ClassDecl);
6895   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
6896 
6897   // Create the actual constructor declaration.
6898   CanQualType ClassType
6899     = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
6900   SourceLocation ClassLoc = ClassDecl->getLocation();
6901   DeclarationName Name
6902     = Context.DeclarationNames.getCXXConstructorName(ClassType);
6903   DeclarationNameInfo NameInfo(Name, ClassLoc);
6904   CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
6905       Context, ClassDecl, ClassLoc, NameInfo,
6906       Context.getFunctionType(Context.VoidTy, 0, 0, EPI), /*TInfo=*/0,
6907       /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
6908       /*isConstexpr=*/ClassDecl->defaultedDefaultConstructorIsConstexpr() &&
6909         getLangOpts().CPlusPlus0x);
6910   DefaultCon->setAccess(AS_public);
6911   DefaultCon->setDefaulted();
6912   DefaultCon->setImplicit();
6913   DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
6914 
6915   // Note that we have declared this constructor.
6916   ++ASTContext::NumImplicitDefaultConstructorsDeclared;
6917 
6918   if (Scope *S = getScopeForContext(ClassDecl))
6919     PushOnScopeChains(DefaultCon, S, false);
6920   ClassDecl->addDecl(DefaultCon);
6921 
6922   if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
6923     DefaultCon->setDeletedAsWritten();
6924 
6925   return DefaultCon;
6926 }
6927 
DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * Constructor)6928 void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
6929                                             CXXConstructorDecl *Constructor) {
6930   assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
6931           !Constructor->doesThisDeclarationHaveABody() &&
6932           !Constructor->isDeleted()) &&
6933     "DefineImplicitDefaultConstructor - call it for implicit default ctor");
6934 
6935   CXXRecordDecl *ClassDecl = Constructor->getParent();
6936   assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
6937 
6938   ImplicitlyDefinedFunctionScope Scope(*this, Constructor);
6939   DiagnosticErrorTrap Trap(Diags);
6940   if (SetCtorInitializers(Constructor, 0, 0, /*AnyErrors=*/false) ||
6941       Trap.hasErrorOccurred()) {
6942     Diag(CurrentLocation, diag::note_member_synthesized_at)
6943       << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl);
6944     Constructor->setInvalidDecl();
6945     return;
6946   }
6947 
6948   SourceLocation Loc = Constructor->getLocation();
6949   Constructor->setBody(new (Context) CompoundStmt(Context, 0, 0, Loc, Loc));
6950 
6951   Constructor->setUsed();
6952   MarkVTableUsed(CurrentLocation, ClassDecl);
6953 
6954   if (ASTMutationListener *L = getASTMutationListener()) {
6955     L->CompletedImplicitDefinition(Constructor);
6956   }
6957 }
6958 
6959 /// Get any existing defaulted default constructor for the given class. Do not
6960 /// implicitly define one if it does not exist.
getDefaultedDefaultConstructorUnsafe(Sema & Self,CXXRecordDecl * D)6961 static CXXConstructorDecl *getDefaultedDefaultConstructorUnsafe(Sema &Self,
6962                                                              CXXRecordDecl *D) {
6963   ASTContext &Context = Self.Context;
6964   QualType ClassType = Context.getTypeDeclType(D);
6965   DeclarationName ConstructorName
6966     = Context.DeclarationNames.getCXXConstructorName(
6967                       Context.getCanonicalType(ClassType.getUnqualifiedType()));
6968 
6969   DeclContext::lookup_const_iterator Con, ConEnd;
6970   for (llvm::tie(Con, ConEnd) = D->lookup(ConstructorName);
6971        Con != ConEnd; ++Con) {
6972     // A function template cannot be defaulted.
6973     if (isa<FunctionTemplateDecl>(*Con))
6974       continue;
6975 
6976     CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
6977     if (Constructor->isDefaultConstructor())
6978       return Constructor->isDefaulted() ? Constructor : 0;
6979   }
6980   return 0;
6981 }
6982 
ActOnFinishDelayedMemberInitializers(Decl * D)6983 void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
6984   if (!D) return;
6985   AdjustDeclIfTemplate(D);
6986 
6987   CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(D);
6988   CXXConstructorDecl *CtorDecl
6989     = getDefaultedDefaultConstructorUnsafe(*this, ClassDecl);
6990 
6991   if (!CtorDecl) return;
6992 
6993   // Compute the exception specification for the default constructor.
6994   const FunctionProtoType *CtorTy =
6995     CtorDecl->getType()->castAs<FunctionProtoType>();
6996   if (CtorTy->getExceptionSpecType() == EST_Delayed) {
6997     // FIXME: Don't do this unless the exception spec is needed.
6998     ImplicitExceptionSpecification Spec =
6999       ComputeDefaultedDefaultCtorExceptionSpec(ClassDecl);
7000     FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
7001     assert(EPI.ExceptionSpecType != EST_Delayed);
7002 
7003     CtorDecl->setType(Context.getFunctionType(Context.VoidTy, 0, 0, EPI));
7004   }
7005 
7006   // If the default constructor is explicitly defaulted, checking the exception
7007   // specification is deferred until now.
7008   if (!CtorDecl->isInvalidDecl() && CtorDecl->isExplicitlyDefaulted() &&
7009       !ClassDecl->isDependentType())
7010     CheckExplicitlyDefaultedDefaultConstructor(CtorDecl);
7011 }
7012 
DeclareInheritedConstructors(CXXRecordDecl * ClassDecl)7013 void Sema::DeclareInheritedConstructors(CXXRecordDecl *ClassDecl) {
7014   // We start with an initial pass over the base classes to collect those that
7015   // inherit constructors from. If there are none, we can forgo all further
7016   // processing.
7017   typedef SmallVector<const RecordType *, 4> BasesVector;
7018   BasesVector BasesToInheritFrom;
7019   for (CXXRecordDecl::base_class_iterator BaseIt = ClassDecl->bases_begin(),
7020                                           BaseE = ClassDecl->bases_end();
7021          BaseIt != BaseE; ++BaseIt) {
7022     if (BaseIt->getInheritConstructors()) {
7023       QualType Base = BaseIt->getType();
7024       if (Base->isDependentType()) {
7025         // If we inherit constructors from anything that is dependent, just
7026         // abort processing altogether. We'll get another chance for the
7027         // instantiations.
7028         return;
7029       }
7030       BasesToInheritFrom.push_back(Base->castAs<RecordType>());
7031     }
7032   }
7033   if (BasesToInheritFrom.empty())
7034     return;
7035 
7036   // Now collect the constructors that we already have in the current class.
7037   // Those take precedence over inherited constructors.
7038   // C++0x [class.inhctor]p3: [...] a constructor is implicitly declared [...]
7039   //   unless there is a user-declared constructor with the same signature in
7040   //   the class where the using-declaration appears.
7041   llvm::SmallSet<const Type *, 8> ExistingConstructors;
7042   for (CXXRecordDecl::ctor_iterator CtorIt = ClassDecl->ctor_begin(),
7043                                     CtorE = ClassDecl->ctor_end();
7044        CtorIt != CtorE; ++CtorIt) {
7045     ExistingConstructors.insert(
7046         Context.getCanonicalType(CtorIt->getType()).getTypePtr());
7047   }
7048 
7049   DeclarationName CreatedCtorName =
7050       Context.DeclarationNames.getCXXConstructorName(
7051           ClassDecl->getTypeForDecl()->getCanonicalTypeUnqualified());
7052 
7053   // Now comes the true work.
7054   // First, we keep a map from constructor types to the base that introduced
7055   // them. Needed for finding conflicting constructors. We also keep the
7056   // actually inserted declarations in there, for pretty diagnostics.
7057   typedef std::pair<CanQualType, CXXConstructorDecl *> ConstructorInfo;
7058   typedef llvm::DenseMap<const Type *, ConstructorInfo> ConstructorToSourceMap;
7059   ConstructorToSourceMap InheritedConstructors;
7060   for (BasesVector::iterator BaseIt = BasesToInheritFrom.begin(),
7061                              BaseE = BasesToInheritFrom.end();
7062        BaseIt != BaseE; ++BaseIt) {
7063     const RecordType *Base = *BaseIt;
7064     CanQualType CanonicalBase = Base->getCanonicalTypeUnqualified();
7065     CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(Base->getDecl());
7066     for (CXXRecordDecl::ctor_iterator CtorIt = BaseDecl->ctor_begin(),
7067                                       CtorE = BaseDecl->ctor_end();
7068          CtorIt != CtorE; ++CtorIt) {
7069       // Find the using declaration for inheriting this base's constructors.
7070       // FIXME: Don't perform name lookup just to obtain a source location!
7071       DeclarationName Name =
7072           Context.DeclarationNames.getCXXConstructorName(CanonicalBase);
7073       LookupResult Result(*this, Name, SourceLocation(), LookupUsingDeclName);
7074       LookupQualifiedName(Result, CurContext);
7075       UsingDecl *UD = Result.getAsSingle<UsingDecl>();
7076       SourceLocation UsingLoc = UD ? UD->getLocation() :
7077                                      ClassDecl->getLocation();
7078 
7079       // C++0x [class.inhctor]p1: The candidate set of inherited constructors
7080       //   from the class X named in the using-declaration consists of actual
7081       //   constructors and notional constructors that result from the
7082       //   transformation of defaulted parameters as follows:
7083       //   - all non-template default constructors of X, and
7084       //   - for each non-template constructor of X that has at least one
7085       //     parameter with a default argument, the set of constructors that
7086       //     results from omitting any ellipsis parameter specification and
7087       //     successively omitting parameters with a default argument from the
7088       //     end of the parameter-type-list.
7089       CXXConstructorDecl *BaseCtor = *CtorIt;
7090       bool CanBeCopyOrMove = BaseCtor->isCopyOrMoveConstructor();
7091       const FunctionProtoType *BaseCtorType =
7092           BaseCtor->getType()->getAs<FunctionProtoType>();
7093 
7094       for (unsigned params = BaseCtor->getMinRequiredArguments(),
7095                     maxParams = BaseCtor->getNumParams();
7096            params <= maxParams; ++params) {
7097         // Skip default constructors. They're never inherited.
7098         if (params == 0)
7099           continue;
7100         // Skip copy and move constructors for the same reason.
7101         if (CanBeCopyOrMove && params == 1)
7102           continue;
7103 
7104         // Build up a function type for this particular constructor.
7105         // FIXME: The working paper does not consider that the exception spec
7106         // for the inheriting constructor might be larger than that of the
7107         // source. This code doesn't yet, either. When it does, this code will
7108         // need to be delayed until after exception specifications and in-class
7109         // member initializers are attached.
7110         const Type *NewCtorType;
7111         if (params == maxParams)
7112           NewCtorType = BaseCtorType;
7113         else {
7114           SmallVector<QualType, 16> Args;
7115           for (unsigned i = 0; i < params; ++i) {
7116             Args.push_back(BaseCtorType->getArgType(i));
7117           }
7118           FunctionProtoType::ExtProtoInfo ExtInfo =
7119               BaseCtorType->getExtProtoInfo();
7120           ExtInfo.Variadic = false;
7121           NewCtorType = Context.getFunctionType(BaseCtorType->getResultType(),
7122                                                 Args.data(), params, ExtInfo)
7123                        .getTypePtr();
7124         }
7125         const Type *CanonicalNewCtorType =
7126             Context.getCanonicalType(NewCtorType);
7127 
7128         // Now that we have the type, first check if the class already has a
7129         // constructor with this signature.
7130         if (ExistingConstructors.count(CanonicalNewCtorType))
7131           continue;
7132 
7133         // Then we check if we have already declared an inherited constructor
7134         // with this signature.
7135         std::pair<ConstructorToSourceMap::iterator, bool> result =
7136             InheritedConstructors.insert(std::make_pair(
7137                 CanonicalNewCtorType,
7138                 std::make_pair(CanonicalBase, (CXXConstructorDecl*)0)));
7139         if (!result.second) {
7140           // Already in the map. If it came from a different class, that's an
7141           // error. Not if it's from the same.
7142           CanQualType PreviousBase = result.first->second.first;
7143           if (CanonicalBase != PreviousBase) {
7144             const CXXConstructorDecl *PrevCtor = result.first->second.second;
7145             const CXXConstructorDecl *PrevBaseCtor =
7146                 PrevCtor->getInheritedConstructor();
7147             assert(PrevBaseCtor && "Conflicting constructor was not inherited");
7148 
7149             Diag(UsingLoc, diag::err_using_decl_constructor_conflict);
7150             Diag(BaseCtor->getLocation(),
7151                  diag::note_using_decl_constructor_conflict_current_ctor);
7152             Diag(PrevBaseCtor->getLocation(),
7153                  diag::note_using_decl_constructor_conflict_previous_ctor);
7154             Diag(PrevCtor->getLocation(),
7155                  diag::note_using_decl_constructor_conflict_previous_using);
7156           }
7157           continue;
7158         }
7159 
7160         // OK, we're there, now add the constructor.
7161         // C++0x [class.inhctor]p8: [...] that would be performed by a
7162         //   user-written inline constructor [...]
7163         DeclarationNameInfo DNI(CreatedCtorName, UsingLoc);
7164         CXXConstructorDecl *NewCtor = CXXConstructorDecl::Create(
7165             Context, ClassDecl, UsingLoc, DNI, QualType(NewCtorType, 0),
7166             /*TInfo=*/0, BaseCtor->isExplicit(), /*Inline=*/true,
7167             /*ImplicitlyDeclared=*/true,
7168             // FIXME: Due to a defect in the standard, we treat inherited
7169             // constructors as constexpr even if that makes them ill-formed.
7170             /*Constexpr=*/BaseCtor->isConstexpr());
7171         NewCtor->setAccess(BaseCtor->getAccess());
7172 
7173         // Build up the parameter decls and add them.
7174         SmallVector<ParmVarDecl *, 16> ParamDecls;
7175         for (unsigned i = 0; i < params; ++i) {
7176           ParamDecls.push_back(ParmVarDecl::Create(Context, NewCtor,
7177                                                    UsingLoc, UsingLoc,
7178                                                    /*IdentifierInfo=*/0,
7179                                                    BaseCtorType->getArgType(i),
7180                                                    /*TInfo=*/0, SC_None,
7181                                                    SC_None, /*DefaultArg=*/0));
7182         }
7183         NewCtor->setParams(ParamDecls);
7184         NewCtor->setInheritedConstructor(BaseCtor);
7185 
7186         ClassDecl->addDecl(NewCtor);
7187         result.first->second.second = NewCtor;
7188       }
7189     }
7190   }
7191 }
7192 
7193 Sema::ImplicitExceptionSpecification
ComputeDefaultedDtorExceptionSpec(CXXRecordDecl * ClassDecl)7194 Sema::ComputeDefaultedDtorExceptionSpec(CXXRecordDecl *ClassDecl) {
7195   // C++ [except.spec]p14:
7196   //   An implicitly declared special member function (Clause 12) shall have
7197   //   an exception-specification.
7198   ImplicitExceptionSpecification ExceptSpec(*this);
7199   if (ClassDecl->isInvalidDecl())
7200     return ExceptSpec;
7201 
7202   // Direct base-class destructors.
7203   for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
7204                                        BEnd = ClassDecl->bases_end();
7205        B != BEnd; ++B) {
7206     if (B->isVirtual()) // Handled below.
7207       continue;
7208 
7209     if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7210       ExceptSpec.CalledDecl(B->getLocStart(),
7211                    LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7212   }
7213 
7214   // Virtual base-class destructors.
7215   for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
7216                                        BEnd = ClassDecl->vbases_end();
7217        B != BEnd; ++B) {
7218     if (const RecordType *BaseType = B->getType()->getAs<RecordType>())
7219       ExceptSpec.CalledDecl(B->getLocStart(),
7220                   LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl())));
7221   }
7222 
7223   // Field destructors.
7224   for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
7225                                FEnd = ClassDecl->field_end();
7226        F != FEnd; ++F) {
7227     if (const RecordType *RecordTy
7228         = Context.getBaseElementType(F->getType())->getAs<RecordType>())
7229       ExceptSpec.CalledDecl(F->getLocation(),
7230                   LookupDestructor(cast<CXXRecordDecl>(RecordTy->getDecl())));
7231   }
7232 
7233   return ExceptSpec;
7234 }
7235 
DeclareImplicitDestructor(CXXRecordDecl * ClassDecl)7236 CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
7237   // C++ [class.dtor]p2:
7238   //   If a class has no user-declared destructor, a destructor is
7239   //   declared implicitly. An implicitly-declared destructor is an
7240   //   inline public member of its class.
7241 
7242   ImplicitExceptionSpecification Spec =
7243       ComputeDefaultedDtorExceptionSpec(ClassDecl);
7244   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
7245 
7246   // Create the actual destructor declaration.
7247   QualType Ty = Context.getFunctionType(Context.VoidTy, 0, 0, EPI);
7248 
7249   CanQualType ClassType
7250     = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
7251   SourceLocation ClassLoc = ClassDecl->getLocation();
7252   DeclarationName Name
7253     = Context.DeclarationNames.getCXXDestructorName(ClassType);
7254   DeclarationNameInfo NameInfo(Name, ClassLoc);
7255   CXXDestructorDecl *Destructor
7256       = CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, Ty, 0,
7257                                   /*isInline=*/true,
7258                                   /*isImplicitlyDeclared=*/true);
7259   Destructor->setAccess(AS_public);
7260   Destructor->setDefaulted();
7261   Destructor->setImplicit();
7262   Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
7263 
7264   // Note that we have declared this destructor.
7265   ++ASTContext::NumImplicitDestructorsDeclared;
7266 
7267   // Introduce this destructor into its scope.
7268   if (Scope *S = getScopeForContext(ClassDecl))
7269     PushOnScopeChains(Destructor, S, false);
7270   ClassDecl->addDecl(Destructor);
7271 
7272   // This could be uniqued if it ever proves significant.
7273   Destructor->setTypeSourceInfo(Context.getTrivialTypeSourceInfo(Ty));
7274 
7275   AddOverriddenMethods(ClassDecl, Destructor);
7276 
7277   if (ShouldDeleteSpecialMember(Destructor, CXXDestructor))
7278     Destructor->setDeletedAsWritten();
7279 
7280   return Destructor;
7281 }
7282 
DefineImplicitDestructor(SourceLocation CurrentLocation,CXXDestructorDecl * Destructor)7283 void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
7284                                     CXXDestructorDecl *Destructor) {
7285   assert((Destructor->isDefaulted() &&
7286           !Destructor->doesThisDeclarationHaveABody() &&
7287           !Destructor->isDeleted()) &&
7288          "DefineImplicitDestructor - call it for implicit default dtor");
7289   CXXRecordDecl *ClassDecl = Destructor->getParent();
7290   assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
7291 
7292   if (Destructor->isInvalidDecl())
7293     return;
7294 
7295   ImplicitlyDefinedFunctionScope Scope(*this, Destructor);
7296 
7297   DiagnosticErrorTrap Trap(Diags);
7298   MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
7299                                          Destructor->getParent());
7300 
7301   if (CheckDestructor(Destructor) || Trap.hasErrorOccurred()) {
7302     Diag(CurrentLocation, diag::note_member_synthesized_at)
7303       << CXXDestructor << Context.getTagDeclType(ClassDecl);
7304 
7305     Destructor->setInvalidDecl();
7306     return;
7307   }
7308 
7309   SourceLocation Loc = Destructor->getLocation();
7310   Destructor->setBody(new (Context) CompoundStmt(Context, 0, 0, Loc, Loc));
7311   Destructor->setImplicitlyDefined(true);
7312   Destructor->setUsed();
7313   MarkVTableUsed(CurrentLocation, ClassDecl);
7314 
7315   if (ASTMutationListener *L = getASTMutationListener()) {
7316     L->CompletedImplicitDefinition(Destructor);
7317   }
7318 }
7319 
AdjustDestructorExceptionSpec(CXXRecordDecl * classDecl,CXXDestructorDecl * destructor)7320 void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *classDecl,
7321                                          CXXDestructorDecl *destructor) {
7322   // C++11 [class.dtor]p3:
7323   //   A declaration of a destructor that does not have an exception-
7324   //   specification is implicitly considered to have the same exception-
7325   //   specification as an implicit declaration.
7326   const FunctionProtoType *dtorType = destructor->getType()->
7327                                         getAs<FunctionProtoType>();
7328   if (dtorType->hasExceptionSpec())
7329     return;
7330 
7331   ImplicitExceptionSpecification exceptSpec =
7332       ComputeDefaultedDtorExceptionSpec(classDecl);
7333 
7334   // Replace the destructor's type, building off the existing one. Fortunately,
7335   // the only thing of interest in the destructor type is its extended info.
7336   // The return and arguments are fixed.
7337   FunctionProtoType::ExtProtoInfo epi = dtorType->getExtProtoInfo();
7338   epi.ExceptionSpecType = exceptSpec.getExceptionSpecType();
7339   epi.NumExceptions = exceptSpec.size();
7340   epi.Exceptions = exceptSpec.data();
7341   QualType ty = Context.getFunctionType(Context.VoidTy, 0, 0, epi);
7342 
7343   destructor->setType(ty);
7344 
7345   // FIXME: If the destructor has a body that could throw, and the newly created
7346   // spec doesn't allow exceptions, we should emit a warning, because this
7347   // change in behavior can break conforming C++03 programs at runtime.
7348   // However, we don't have a body yet, so it needs to be done somewhere else.
7349 }
7350 
7351 /// \brief Builds a statement that copies/moves the given entity from \p From to
7352 /// \c To.
7353 ///
7354 /// This routine is used to copy/move the members of a class with an
7355 /// implicitly-declared copy/move assignment operator. When the entities being
7356 /// copied are arrays, this routine builds for loops to copy them.
7357 ///
7358 /// \param S The Sema object used for type-checking.
7359 ///
7360 /// \param Loc The location where the implicit copy/move is being generated.
7361 ///
7362 /// \param T The type of the expressions being copied/moved. Both expressions
7363 /// must have this type.
7364 ///
7365 /// \param To The expression we are copying/moving to.
7366 ///
7367 /// \param From The expression we are copying/moving from.
7368 ///
7369 /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
7370 /// Otherwise, it's a non-static member subobject.
7371 ///
7372 /// \param Copying Whether we're copying or moving.
7373 ///
7374 /// \param Depth Internal parameter recording the depth of the recursion.
7375 ///
7376 /// \returns A statement or a loop that copies the expressions.
7377 static StmtResult
BuildSingleCopyAssign(Sema & S,SourceLocation Loc,QualType T,Expr * To,Expr * From,bool CopyingBaseSubobject,bool Copying,unsigned Depth=0)7378 BuildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
7379                       Expr *To, Expr *From,
7380                       bool CopyingBaseSubobject, bool Copying,
7381                       unsigned Depth = 0) {
7382   // C++0x [class.copy]p28:
7383   //   Each subobject is assigned in the manner appropriate to its type:
7384   //
7385   //     - if the subobject is of class type, as if by a call to operator= with
7386   //       the subobject as the object expression and the corresponding
7387   //       subobject of x as a single function argument (as if by explicit
7388   //       qualification; that is, ignoring any possible virtual overriding
7389   //       functions in more derived classes);
7390   if (const RecordType *RecordTy = T->getAs<RecordType>()) {
7391     CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
7392 
7393     // Look for operator=.
7394     DeclarationName Name
7395       = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7396     LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
7397     S.LookupQualifiedName(OpLookup, ClassDecl, false);
7398 
7399     // Filter out any result that isn't a copy/move-assignment operator.
7400     LookupResult::Filter F = OpLookup.makeFilter();
7401     while (F.hasNext()) {
7402       NamedDecl *D = F.next();
7403       if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
7404         if (Method->isCopyAssignmentOperator() ||
7405             (!Copying && Method->isMoveAssignmentOperator()))
7406           continue;
7407 
7408       F.erase();
7409     }
7410     F.done();
7411 
7412     // Suppress the protected check (C++ [class.protected]) for each of the
7413     // assignment operators we found. This strange dance is required when
7414     // we're assigning via a base classes's copy-assignment operator. To
7415     // ensure that we're getting the right base class subobject (without
7416     // ambiguities), we need to cast "this" to that subobject type; to
7417     // ensure that we don't go through the virtual call mechanism, we need
7418     // to qualify the operator= name with the base class (see below). However,
7419     // this means that if the base class has a protected copy assignment
7420     // operator, the protected member access check will fail. So, we
7421     // rewrite "protected" access to "public" access in this case, since we
7422     // know by construction that we're calling from a derived class.
7423     if (CopyingBaseSubobject) {
7424       for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
7425            L != LEnd; ++L) {
7426         if (L.getAccess() == AS_protected)
7427           L.setAccess(AS_public);
7428       }
7429     }
7430 
7431     // Create the nested-name-specifier that will be used to qualify the
7432     // reference to operator=; this is required to suppress the virtual
7433     // call mechanism.
7434     CXXScopeSpec SS;
7435     const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
7436     SS.MakeTrivial(S.Context,
7437                    NestedNameSpecifier::Create(S.Context, 0, false,
7438                                                CanonicalT),
7439                    Loc);
7440 
7441     // Create the reference to operator=.
7442     ExprResult OpEqualRef
7443       = S.BuildMemberReferenceExpr(To, T, Loc, /*isArrow=*/false, SS,
7444                                    /*TemplateKWLoc=*/SourceLocation(),
7445                                    /*FirstQualifierInScope=*/0,
7446                                    OpLookup,
7447                                    /*TemplateArgs=*/0,
7448                                    /*SuppressQualifierCheck=*/true);
7449     if (OpEqualRef.isInvalid())
7450       return StmtError();
7451 
7452     // Build the call to the assignment operator.
7453 
7454     ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/0,
7455                                                   OpEqualRef.takeAs<Expr>(),
7456                                                   Loc, &From, 1, Loc);
7457     if (Call.isInvalid())
7458       return StmtError();
7459 
7460     return S.Owned(Call.takeAs<Stmt>());
7461   }
7462 
7463   //     - if the subobject is of scalar type, the built-in assignment
7464   //       operator is used.
7465   const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
7466   if (!ArrayTy) {
7467     ExprResult Assignment = S.CreateBuiltinBinOp(Loc, BO_Assign, To, From);
7468     if (Assignment.isInvalid())
7469       return StmtError();
7470 
7471     return S.Owned(Assignment.takeAs<Stmt>());
7472   }
7473 
7474   //     - if the subobject is an array, each element is assigned, in the
7475   //       manner appropriate to the element type;
7476 
7477   // Construct a loop over the array bounds, e.g.,
7478   //
7479   //   for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
7480   //
7481   // that will copy each of the array elements.
7482   QualType SizeType = S.Context.getSizeType();
7483 
7484   // Create the iteration variable.
7485   IdentifierInfo *IterationVarName = 0;
7486   {
7487     SmallString<8> Str;
7488     llvm::raw_svector_ostream OS(Str);
7489     OS << "__i" << Depth;
7490     IterationVarName = &S.Context.Idents.get(OS.str());
7491   }
7492   VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
7493                                           IterationVarName, SizeType,
7494                             S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
7495                                           SC_None, SC_None);
7496 
7497   // Initialize the iteration variable to zero.
7498   llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
7499   IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
7500 
7501   // Create a reference to the iteration variable; we'll use this several
7502   // times throughout.
7503   Expr *IterationVarRef
7504     = S.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc).take();
7505   assert(IterationVarRef && "Reference to invented variable cannot fail!");
7506   Expr *IterationVarRefRVal = S.DefaultLvalueConversion(IterationVarRef).take();
7507   assert(IterationVarRefRVal && "Conversion of invented variable cannot fail!");
7508 
7509   // Create the DeclStmt that holds the iteration variable.
7510   Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
7511 
7512   // Create the comparison against the array bound.
7513   llvm::APInt Upper
7514     = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
7515   Expr *Comparison
7516     = new (S.Context) BinaryOperator(IterationVarRefRVal,
7517                      IntegerLiteral::Create(S.Context, Upper, SizeType, Loc),
7518                                      BO_NE, S.Context.BoolTy,
7519                                      VK_RValue, OK_Ordinary, Loc);
7520 
7521   // Create the pre-increment of the iteration variable.
7522   Expr *Increment
7523     = new (S.Context) UnaryOperator(IterationVarRef, UO_PreInc, SizeType,
7524                                     VK_LValue, OK_Ordinary, Loc);
7525 
7526   // Subscript the "from" and "to" expressions with the iteration variable.
7527   From = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(From, Loc,
7528                                                          IterationVarRefRVal,
7529                                                          Loc));
7530   To = AssertSuccess(S.CreateBuiltinArraySubscriptExpr(To, Loc,
7531                                                        IterationVarRefRVal,
7532                                                        Loc));
7533   if (!Copying) // Cast to rvalue
7534     From = CastForMoving(S, From);
7535 
7536   // Build the copy/move for an individual element of the array.
7537   StmtResult Copy = BuildSingleCopyAssign(S, Loc, ArrayTy->getElementType(),
7538                                           To, From, CopyingBaseSubobject,
7539                                           Copying, Depth + 1);
7540   if (Copy.isInvalid())
7541     return StmtError();
7542 
7543   // Construct the loop that copies all elements of this array.
7544   return S.ActOnForStmt(Loc, Loc, InitStmt,
7545                         S.MakeFullExpr(Comparison),
7546                         0, S.MakeFullExpr(Increment),
7547                         Loc, Copy.take());
7548 }
7549 
7550 std::pair<Sema::ImplicitExceptionSpecification, bool>
ComputeDefaultedCopyAssignmentExceptionSpecAndConst(CXXRecordDecl * ClassDecl)7551 Sema::ComputeDefaultedCopyAssignmentExceptionSpecAndConst(
7552                                                    CXXRecordDecl *ClassDecl) {
7553   if (ClassDecl->isInvalidDecl())
7554     return std::make_pair(ImplicitExceptionSpecification(*this), false);
7555 
7556   // C++ [class.copy]p10:
7557   //   If the class definition does not explicitly declare a copy
7558   //   assignment operator, one is declared implicitly.
7559   //   The implicitly-defined copy assignment operator for a class X
7560   //   will have the form
7561   //
7562   //       X& X::operator=(const X&)
7563   //
7564   //   if
7565   bool HasConstCopyAssignment = true;
7566 
7567   //       -- each direct base class B of X has a copy assignment operator
7568   //          whose parameter is of type const B&, const volatile B& or B,
7569   //          and
7570   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7571                                        BaseEnd = ClassDecl->bases_end();
7572        HasConstCopyAssignment && Base != BaseEnd; ++Base) {
7573     // We'll handle this below
7574     if (LangOpts.CPlusPlus0x && Base->isVirtual())
7575       continue;
7576 
7577     assert(!Base->getType()->isDependentType() &&
7578            "Cannot generate implicit members for class with dependent bases.");
7579     CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7580     LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const, false, 0,
7581                             &HasConstCopyAssignment);
7582   }
7583 
7584   // In C++11, the above citation has "or virtual" added
7585   if (LangOpts.CPlusPlus0x) {
7586     for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7587                                          BaseEnd = ClassDecl->vbases_end();
7588          HasConstCopyAssignment && Base != BaseEnd; ++Base) {
7589       assert(!Base->getType()->isDependentType() &&
7590              "Cannot generate implicit members for class with dependent bases.");
7591       CXXRecordDecl *BaseClassDecl = Base->getType()->getAsCXXRecordDecl();
7592       LookupCopyingAssignment(BaseClassDecl, Qualifiers::Const, false, 0,
7593                               &HasConstCopyAssignment);
7594     }
7595   }
7596 
7597   //       -- for all the nonstatic data members of X that are of a class
7598   //          type M (or array thereof), each such class type has a copy
7599   //          assignment operator whose parameter is of type const M&,
7600   //          const volatile M& or M.
7601   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7602                                   FieldEnd = ClassDecl->field_end();
7603        HasConstCopyAssignment && Field != FieldEnd;
7604        ++Field) {
7605     QualType FieldType = Context.getBaseElementType((*Field)->getType());
7606     if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7607       LookupCopyingAssignment(FieldClassDecl, Qualifiers::Const, false, 0,
7608                               &HasConstCopyAssignment);
7609     }
7610   }
7611 
7612   //   Otherwise, the implicitly declared copy assignment operator will
7613   //   have the form
7614   //
7615   //       X& X::operator=(X&)
7616 
7617   // C++ [except.spec]p14:
7618   //   An implicitly declared special member function (Clause 12) shall have an
7619   //   exception-specification. [...]
7620 
7621   // It is unspecified whether or not an implicit copy assignment operator
7622   // attempts to deduplicate calls to assignment operators of virtual bases are
7623   // made. As such, this exception specification is effectively unspecified.
7624   // Based on a similar decision made for constness in C++0x, we're erring on
7625   // the side of assuming such calls to be made regardless of whether they
7626   // actually happen.
7627   ImplicitExceptionSpecification ExceptSpec(*this);
7628   unsigned ArgQuals = HasConstCopyAssignment ? Qualifiers::Const : 0;
7629   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7630                                        BaseEnd = ClassDecl->bases_end();
7631        Base != BaseEnd; ++Base) {
7632     if (Base->isVirtual())
7633       continue;
7634 
7635     CXXRecordDecl *BaseClassDecl
7636       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7637     if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7638                                                             ArgQuals, false, 0))
7639       ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7640   }
7641 
7642   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
7643                                        BaseEnd = ClassDecl->vbases_end();
7644        Base != BaseEnd; ++Base) {
7645     CXXRecordDecl *BaseClassDecl
7646       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
7647     if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl,
7648                                                             ArgQuals, false, 0))
7649       ExceptSpec.CalledDecl(Base->getLocStart(), CopyAssign);
7650   }
7651 
7652   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7653                                   FieldEnd = ClassDecl->field_end();
7654        Field != FieldEnd;
7655        ++Field) {
7656     QualType FieldType = Context.getBaseElementType((*Field)->getType());
7657     if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
7658       if (CXXMethodDecl *CopyAssign =
7659           LookupCopyingAssignment(FieldClassDecl, ArgQuals, false, 0))
7660         ExceptSpec.CalledDecl(Field->getLocation(), CopyAssign);
7661     }
7662   }
7663 
7664   return std::make_pair(ExceptSpec, HasConstCopyAssignment);
7665 }
7666 
DeclareImplicitCopyAssignment(CXXRecordDecl * ClassDecl)7667 CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
7668   // Note: The following rules are largely analoguous to the copy
7669   // constructor rules. Note that virtual bases are not taken into account
7670   // for determining the argument type of the operator. Note also that
7671   // operators taking an object instead of a reference are allowed.
7672 
7673   ImplicitExceptionSpecification Spec(*this);
7674   bool Const;
7675   llvm::tie(Spec, Const) =
7676     ComputeDefaultedCopyAssignmentExceptionSpecAndConst(ClassDecl);
7677 
7678   QualType ArgType = Context.getTypeDeclType(ClassDecl);
7679   QualType RetType = Context.getLValueReferenceType(ArgType);
7680   if (Const)
7681     ArgType = ArgType.withConst();
7682   ArgType = Context.getLValueReferenceType(ArgType);
7683 
7684   //   An implicitly-declared copy assignment operator is an inline public
7685   //   member of its class.
7686   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
7687   DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
7688   SourceLocation ClassLoc = ClassDecl->getLocation();
7689   DeclarationNameInfo NameInfo(Name, ClassLoc);
7690   CXXMethodDecl *CopyAssignment
7691     = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
7692                             Context.getFunctionType(RetType, &ArgType, 1, EPI),
7693                             /*TInfo=*/0, /*isStatic=*/false,
7694                             /*StorageClassAsWritten=*/SC_None,
7695                             /*isInline=*/true, /*isConstexpr=*/false,
7696                             SourceLocation());
7697   CopyAssignment->setAccess(AS_public);
7698   CopyAssignment->setDefaulted();
7699   CopyAssignment->setImplicit();
7700   CopyAssignment->setTrivial(ClassDecl->hasTrivialCopyAssignment());
7701 
7702   // Add the parameter to the operator.
7703   ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
7704                                                ClassLoc, ClassLoc, /*Id=*/0,
7705                                                ArgType, /*TInfo=*/0,
7706                                                SC_None,
7707                                                SC_None, 0);
7708   CopyAssignment->setParams(FromParam);
7709 
7710   // Note that we have added this copy-assignment operator.
7711   ++ASTContext::NumImplicitCopyAssignmentOperatorsDeclared;
7712 
7713   if (Scope *S = getScopeForContext(ClassDecl))
7714     PushOnScopeChains(CopyAssignment, S, false);
7715   ClassDecl->addDecl(CopyAssignment);
7716 
7717   // C++0x [class.copy]p19:
7718   //   ....  If the class definition does not explicitly declare a copy
7719   //   assignment operator, there is no user-declared move constructor, and
7720   //   there is no user-declared move assignment operator, a copy assignment
7721   //   operator is implicitly declared as defaulted.
7722   if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment))
7723     CopyAssignment->setDeletedAsWritten();
7724 
7725   AddOverriddenMethods(ClassDecl, CopyAssignment);
7726   return CopyAssignment;
7727 }
7728 
DefineImplicitCopyAssignment(SourceLocation CurrentLocation,CXXMethodDecl * CopyAssignOperator)7729 void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
7730                                         CXXMethodDecl *CopyAssignOperator) {
7731   assert((CopyAssignOperator->isDefaulted() &&
7732           CopyAssignOperator->isOverloadedOperator() &&
7733           CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
7734           !CopyAssignOperator->doesThisDeclarationHaveABody() &&
7735           !CopyAssignOperator->isDeleted()) &&
7736          "DefineImplicitCopyAssignment called for wrong function");
7737 
7738   CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
7739 
7740   if (ClassDecl->isInvalidDecl() || CopyAssignOperator->isInvalidDecl()) {
7741     CopyAssignOperator->setInvalidDecl();
7742     return;
7743   }
7744 
7745   CopyAssignOperator->setUsed();
7746 
7747   ImplicitlyDefinedFunctionScope Scope(*this, CopyAssignOperator);
7748   DiagnosticErrorTrap Trap(Diags);
7749 
7750   // C++0x [class.copy]p30:
7751   //   The implicitly-defined or explicitly-defaulted copy assignment operator
7752   //   for a non-union class X performs memberwise copy assignment of its
7753   //   subobjects. The direct base classes of X are assigned first, in the
7754   //   order of their declaration in the base-specifier-list, and then the
7755   //   immediate non-static data members of X are assigned, in the order in
7756   //   which they were declared in the class definition.
7757 
7758   // The statements that form the synthesized function body.
7759   ASTOwningVector<Stmt*> Statements(*this);
7760 
7761   // The parameter for the "other" object, which we are copying from.
7762   ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
7763   Qualifiers OtherQuals = Other->getType().getQualifiers();
7764   QualType OtherRefType = Other->getType();
7765   if (const LValueReferenceType *OtherRef
7766                                 = OtherRefType->getAs<LValueReferenceType>()) {
7767     OtherRefType = OtherRef->getPointeeType();
7768     OtherQuals = OtherRefType.getQualifiers();
7769   }
7770 
7771   // Our location for everything implicitly-generated.
7772   SourceLocation Loc = CopyAssignOperator->getLocation();
7773 
7774   // Construct a reference to the "other" object. We'll be using this
7775   // throughout the generated ASTs.
7776   Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
7777   assert(OtherRef && "Reference to parameter cannot fail!");
7778 
7779   // Construct the "this" pointer. We'll be using this throughout the generated
7780   // ASTs.
7781   Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
7782   assert(This && "Reference to this cannot fail!");
7783 
7784   // Assign base classes.
7785   bool Invalid = false;
7786   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
7787        E = ClassDecl->bases_end(); Base != E; ++Base) {
7788     // Form the assignment:
7789     //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
7790     QualType BaseType = Base->getType().getUnqualifiedType();
7791     if (!BaseType->isRecordType()) {
7792       Invalid = true;
7793       continue;
7794     }
7795 
7796     CXXCastPath BasePath;
7797     BasePath.push_back(Base);
7798 
7799     // Construct the "from" expression, which is an implicit cast to the
7800     // appropriately-qualified base type.
7801     Expr *From = OtherRef;
7802     From = ImpCastExprToType(From, Context.getQualifiedType(BaseType, OtherQuals),
7803                              CK_UncheckedDerivedToBase,
7804                              VK_LValue, &BasePath).take();
7805 
7806     // Dereference "this".
7807     ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
7808 
7809     // Implicitly cast "this" to the appropriately-qualified base type.
7810     To = ImpCastExprToType(To.take(),
7811                            Context.getCVRQualifiedType(BaseType,
7812                                      CopyAssignOperator->getTypeQualifiers()),
7813                            CK_UncheckedDerivedToBase,
7814                            VK_LValue, &BasePath);
7815 
7816     // Build the copy.
7817     StmtResult Copy = BuildSingleCopyAssign(*this, Loc, BaseType,
7818                                             To.get(), From,
7819                                             /*CopyingBaseSubobject=*/true,
7820                                             /*Copying=*/true);
7821     if (Copy.isInvalid()) {
7822       Diag(CurrentLocation, diag::note_member_synthesized_at)
7823         << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7824       CopyAssignOperator->setInvalidDecl();
7825       return;
7826     }
7827 
7828     // Success! Record the copy.
7829     Statements.push_back(Copy.takeAs<Expr>());
7830   }
7831 
7832   // \brief Reference to the __builtin_memcpy function.
7833   Expr *BuiltinMemCpyRef = 0;
7834   // \brief Reference to the __builtin_objc_memmove_collectable function.
7835   Expr *CollectableMemCpyRef = 0;
7836 
7837   // Assign non-static members.
7838   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
7839                                   FieldEnd = ClassDecl->field_end();
7840        Field != FieldEnd; ++Field) {
7841     if (Field->isUnnamedBitfield())
7842       continue;
7843 
7844     // Check for members of reference type; we can't copy those.
7845     if (Field->getType()->isReferenceType()) {
7846       Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7847         << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
7848       Diag(Field->getLocation(), diag::note_declared_at);
7849       Diag(CurrentLocation, diag::note_member_synthesized_at)
7850         << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7851       Invalid = true;
7852       continue;
7853     }
7854 
7855     // Check for members of const-qualified, non-class type.
7856     QualType BaseType = Context.getBaseElementType(Field->getType());
7857     if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
7858       Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
7859         << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
7860       Diag(Field->getLocation(), diag::note_declared_at);
7861       Diag(CurrentLocation, diag::note_member_synthesized_at)
7862         << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7863       Invalid = true;
7864       continue;
7865     }
7866 
7867     // Suppress assigning zero-width bitfields.
7868     if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
7869       continue;
7870 
7871     QualType FieldType = Field->getType().getNonReferenceType();
7872     if (FieldType->isIncompleteArrayType()) {
7873       assert(ClassDecl->hasFlexibleArrayMember() &&
7874              "Incomplete array type is not valid");
7875       continue;
7876     }
7877 
7878     // Build references to the field in the object we're copying from and to.
7879     CXXScopeSpec SS; // Intentionally empty
7880     LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
7881                               LookupMemberName);
7882     MemberLookup.addDecl(*Field);
7883     MemberLookup.resolveKind();
7884     ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
7885                                                Loc, /*IsArrow=*/false,
7886                                                SS, SourceLocation(), 0,
7887                                                MemberLookup, 0);
7888     ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
7889                                              Loc, /*IsArrow=*/true,
7890                                              SS, SourceLocation(), 0,
7891                                              MemberLookup, 0);
7892     assert(!From.isInvalid() && "Implicit field reference cannot fail");
7893     assert(!To.isInvalid() && "Implicit field reference cannot fail");
7894 
7895     // If the field should be copied with __builtin_memcpy rather than via
7896     // explicit assignments, do so. This optimization only applies for arrays
7897     // of scalars and arrays of class type with trivial copy-assignment
7898     // operators.
7899     if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
7900         && BaseType.hasTrivialAssignment(Context, /*Copying=*/true)) {
7901       // Compute the size of the memory buffer to be copied.
7902       QualType SizeType = Context.getSizeType();
7903       llvm::APInt Size(Context.getTypeSize(SizeType),
7904                        Context.getTypeSizeInChars(BaseType).getQuantity());
7905       for (const ConstantArrayType *Array
7906               = Context.getAsConstantArrayType(FieldType);
7907            Array;
7908            Array = Context.getAsConstantArrayType(Array->getElementType())) {
7909         llvm::APInt ArraySize
7910           = Array->getSize().zextOrTrunc(Size.getBitWidth());
7911         Size *= ArraySize;
7912       }
7913 
7914       // Take the address of the field references for "from" and "to".
7915       From = CreateBuiltinUnaryOp(Loc, UO_AddrOf, From.get());
7916       To = CreateBuiltinUnaryOp(Loc, UO_AddrOf, To.get());
7917 
7918       bool NeedsCollectableMemCpy =
7919           (BaseType->isRecordType() &&
7920            BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
7921 
7922       if (NeedsCollectableMemCpy) {
7923         if (!CollectableMemCpyRef) {
7924           // Create a reference to the __builtin_objc_memmove_collectable function.
7925           LookupResult R(*this,
7926                          &Context.Idents.get("__builtin_objc_memmove_collectable"),
7927                          Loc, LookupOrdinaryName);
7928           LookupName(R, TUScope, true);
7929 
7930           FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
7931           if (!CollectableMemCpy) {
7932             // Something went horribly wrong earlier, and we will have
7933             // complained about it.
7934             Invalid = true;
7935             continue;
7936           }
7937 
7938           CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
7939                                                   CollectableMemCpy->getType(),
7940                                                   VK_LValue, Loc, 0).take();
7941           assert(CollectableMemCpyRef && "Builtin reference cannot fail");
7942         }
7943       }
7944       // Create a reference to the __builtin_memcpy builtin function.
7945       else if (!BuiltinMemCpyRef) {
7946         LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
7947                        LookupOrdinaryName);
7948         LookupName(R, TUScope, true);
7949 
7950         FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
7951         if (!BuiltinMemCpy) {
7952           // Something went horribly wrong earlier, and we will have complained
7953           // about it.
7954           Invalid = true;
7955           continue;
7956         }
7957 
7958         BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
7959                                             BuiltinMemCpy->getType(),
7960                                             VK_LValue, Loc, 0).take();
7961         assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
7962       }
7963 
7964       ASTOwningVector<Expr*> CallArgs(*this);
7965       CallArgs.push_back(To.takeAs<Expr>());
7966       CallArgs.push_back(From.takeAs<Expr>());
7967       CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
7968       ExprResult Call = ExprError();
7969       if (NeedsCollectableMemCpy)
7970         Call = ActOnCallExpr(/*Scope=*/0,
7971                              CollectableMemCpyRef,
7972                              Loc, move_arg(CallArgs),
7973                              Loc);
7974       else
7975         Call = ActOnCallExpr(/*Scope=*/0,
7976                              BuiltinMemCpyRef,
7977                              Loc, move_arg(CallArgs),
7978                              Loc);
7979 
7980       assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
7981       Statements.push_back(Call.takeAs<Expr>());
7982       continue;
7983     }
7984 
7985     // Build the copy of this field.
7986     StmtResult Copy = BuildSingleCopyAssign(*this, Loc, FieldType,
7987                                             To.get(), From.get(),
7988                                             /*CopyingBaseSubobject=*/false,
7989                                             /*Copying=*/true);
7990     if (Copy.isInvalid()) {
7991       Diag(CurrentLocation, diag::note_member_synthesized_at)
7992         << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
7993       CopyAssignOperator->setInvalidDecl();
7994       return;
7995     }
7996 
7997     // Success! Record the copy.
7998     Statements.push_back(Copy.takeAs<Stmt>());
7999   }
8000 
8001   if (!Invalid) {
8002     // Add a "return *this;"
8003     ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8004 
8005     StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
8006     if (Return.isInvalid())
8007       Invalid = true;
8008     else {
8009       Statements.push_back(Return.takeAs<Stmt>());
8010 
8011       if (Trap.hasErrorOccurred()) {
8012         Diag(CurrentLocation, diag::note_member_synthesized_at)
8013           << CXXCopyAssignment << Context.getTagDeclType(ClassDecl);
8014         Invalid = true;
8015       }
8016     }
8017   }
8018 
8019   if (Invalid) {
8020     CopyAssignOperator->setInvalidDecl();
8021     return;
8022   }
8023 
8024   StmtResult Body;
8025   {
8026     CompoundScopeRAII CompoundScope(*this);
8027     Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
8028                              /*isStmtExpr=*/false);
8029     assert(!Body.isInvalid() && "Compound statement creation cannot fail");
8030   }
8031   CopyAssignOperator->setBody(Body.takeAs<Stmt>());
8032 
8033   if (ASTMutationListener *L = getASTMutationListener()) {
8034     L->CompletedImplicitDefinition(CopyAssignOperator);
8035   }
8036 }
8037 
8038 Sema::ImplicitExceptionSpecification
ComputeDefaultedMoveAssignmentExceptionSpec(CXXRecordDecl * ClassDecl)8039 Sema::ComputeDefaultedMoveAssignmentExceptionSpec(CXXRecordDecl *ClassDecl) {
8040   ImplicitExceptionSpecification ExceptSpec(*this);
8041 
8042   if (ClassDecl->isInvalidDecl())
8043     return ExceptSpec;
8044 
8045   // C++0x [except.spec]p14:
8046   //   An implicitly declared special member function (Clause 12) shall have an
8047   //   exception-specification. [...]
8048 
8049   // It is unspecified whether or not an implicit move assignment operator
8050   // attempts to deduplicate calls to assignment operators of virtual bases are
8051   // made. As such, this exception specification is effectively unspecified.
8052   // Based on a similar decision made for constness in C++0x, we're erring on
8053   // the side of assuming such calls to be made regardless of whether they
8054   // actually happen.
8055   // Note that a move constructor is not implicitly declared when there are
8056   // virtual bases, but it can still be user-declared and explicitly defaulted.
8057   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8058                                        BaseEnd = ClassDecl->bases_end();
8059        Base != BaseEnd; ++Base) {
8060     if (Base->isVirtual())
8061       continue;
8062 
8063     CXXRecordDecl *BaseClassDecl
8064       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8065     if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
8066                                                            false, 0))
8067       ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
8068   }
8069 
8070   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8071                                        BaseEnd = ClassDecl->vbases_end();
8072        Base != BaseEnd; ++Base) {
8073     CXXRecordDecl *BaseClassDecl
8074       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8075     if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl,
8076                                                            false, 0))
8077       ExceptSpec.CalledDecl(Base->getLocStart(), MoveAssign);
8078   }
8079 
8080   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8081                                   FieldEnd = ClassDecl->field_end();
8082        Field != FieldEnd;
8083        ++Field) {
8084     QualType FieldType = Context.getBaseElementType((*Field)->getType());
8085     if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8086       if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(FieldClassDecl,
8087                                                              false, 0))
8088         ExceptSpec.CalledDecl(Field->getLocation(), MoveAssign);
8089     }
8090   }
8091 
8092   return ExceptSpec;
8093 }
8094 
8095 /// Determine whether the class type has any direct or indirect virtual base
8096 /// classes which have a non-trivial move assignment operator.
8097 static bool
hasVirtualBaseWithNonTrivialMoveAssignment(Sema & S,CXXRecordDecl * ClassDecl)8098 hasVirtualBaseWithNonTrivialMoveAssignment(Sema &S, CXXRecordDecl *ClassDecl) {
8099   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8100                                           BaseEnd = ClassDecl->vbases_end();
8101        Base != BaseEnd; ++Base) {
8102     CXXRecordDecl *BaseClass =
8103         cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8104 
8105     // Try to declare the move assignment. If it would be deleted, then the
8106     // class does not have a non-trivial move assignment.
8107     if (BaseClass->needsImplicitMoveAssignment())
8108       S.DeclareImplicitMoveAssignment(BaseClass);
8109 
8110     // If the class has both a trivial move assignment and a non-trivial move
8111     // assignment, hasTrivialMoveAssignment() is false.
8112     if (BaseClass->hasDeclaredMoveAssignment() &&
8113         !BaseClass->hasTrivialMoveAssignment())
8114       return true;
8115   }
8116 
8117   return false;
8118 }
8119 
8120 /// Determine whether the given type either has a move constructor or is
8121 /// trivially copyable.
8122 static bool
hasMoveOrIsTriviallyCopyable(Sema & S,QualType Type,bool IsConstructor)8123 hasMoveOrIsTriviallyCopyable(Sema &S, QualType Type, bool IsConstructor) {
8124   Type = S.Context.getBaseElementType(Type);
8125 
8126   // FIXME: Technically, non-trivially-copyable non-class types, such as
8127   // reference types, are supposed to return false here, but that appears
8128   // to be a standard defect.
8129   CXXRecordDecl *ClassDecl = Type->getAsCXXRecordDecl();
8130   if (!ClassDecl)
8131     return true;
8132 
8133   if (Type.isTriviallyCopyableType(S.Context))
8134     return true;
8135 
8136   if (IsConstructor) {
8137     if (ClassDecl->needsImplicitMoveConstructor())
8138       S.DeclareImplicitMoveConstructor(ClassDecl);
8139     return ClassDecl->hasDeclaredMoveConstructor();
8140   }
8141 
8142   if (ClassDecl->needsImplicitMoveAssignment())
8143     S.DeclareImplicitMoveAssignment(ClassDecl);
8144   return ClassDecl->hasDeclaredMoveAssignment();
8145 }
8146 
8147 /// Determine whether all non-static data members and direct or virtual bases
8148 /// of class \p ClassDecl have either a move operation, or are trivially
8149 /// copyable.
subobjectsHaveMoveOrTrivialCopy(Sema & S,CXXRecordDecl * ClassDecl,bool IsConstructor)8150 static bool subobjectsHaveMoveOrTrivialCopy(Sema &S, CXXRecordDecl *ClassDecl,
8151                                             bool IsConstructor) {
8152   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8153                                           BaseEnd = ClassDecl->bases_end();
8154        Base != BaseEnd; ++Base) {
8155     if (Base->isVirtual())
8156       continue;
8157 
8158     if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8159       return false;
8160   }
8161 
8162   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8163                                           BaseEnd = ClassDecl->vbases_end();
8164        Base != BaseEnd; ++Base) {
8165     if (!hasMoveOrIsTriviallyCopyable(S, Base->getType(), IsConstructor))
8166       return false;
8167   }
8168 
8169   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8170                                      FieldEnd = ClassDecl->field_end();
8171        Field != FieldEnd; ++Field) {
8172     if (!hasMoveOrIsTriviallyCopyable(S, (*Field)->getType(), IsConstructor))
8173       return false;
8174   }
8175 
8176   return true;
8177 }
8178 
DeclareImplicitMoveAssignment(CXXRecordDecl * ClassDecl)8179 CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
8180   // C++11 [class.copy]p20:
8181   //   If the definition of a class X does not explicitly declare a move
8182   //   assignment operator, one will be implicitly declared as defaulted
8183   //   if and only if:
8184   //
8185   //   - [first 4 bullets]
8186   assert(ClassDecl->needsImplicitMoveAssignment());
8187 
8188   // [Checked after we build the declaration]
8189   //   - the move assignment operator would not be implicitly defined as
8190   //     deleted,
8191 
8192   // [DR1402]:
8193   //   - X has no direct or indirect virtual base class with a non-trivial
8194   //     move assignment operator, and
8195   //   - each of X's non-static data members and direct or virtual base classes
8196   //     has a type that either has a move assignment operator or is trivially
8197   //     copyable.
8198   if (hasVirtualBaseWithNonTrivialMoveAssignment(*this, ClassDecl) ||
8199       !subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl,/*Constructor*/false)) {
8200     ClassDecl->setFailedImplicitMoveAssignment();
8201     return 0;
8202   }
8203 
8204   // Note: The following rules are largely analoguous to the move
8205   // constructor rules.
8206 
8207   ImplicitExceptionSpecification Spec(
8208       ComputeDefaultedMoveAssignmentExceptionSpec(ClassDecl));
8209 
8210   QualType ArgType = Context.getTypeDeclType(ClassDecl);
8211   QualType RetType = Context.getLValueReferenceType(ArgType);
8212   ArgType = Context.getRValueReferenceType(ArgType);
8213 
8214   //   An implicitly-declared move assignment operator is an inline public
8215   //   member of its class.
8216   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8217   DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
8218   SourceLocation ClassLoc = ClassDecl->getLocation();
8219   DeclarationNameInfo NameInfo(Name, ClassLoc);
8220   CXXMethodDecl *MoveAssignment
8221     = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
8222                             Context.getFunctionType(RetType, &ArgType, 1, EPI),
8223                             /*TInfo=*/0, /*isStatic=*/false,
8224                             /*StorageClassAsWritten=*/SC_None,
8225                             /*isInline=*/true,
8226                             /*isConstexpr=*/false,
8227                             SourceLocation());
8228   MoveAssignment->setAccess(AS_public);
8229   MoveAssignment->setDefaulted();
8230   MoveAssignment->setImplicit();
8231   MoveAssignment->setTrivial(ClassDecl->hasTrivialMoveAssignment());
8232 
8233   // Add the parameter to the operator.
8234   ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
8235                                                ClassLoc, ClassLoc, /*Id=*/0,
8236                                                ArgType, /*TInfo=*/0,
8237                                                SC_None,
8238                                                SC_None, 0);
8239   MoveAssignment->setParams(FromParam);
8240 
8241   // Note that we have added this copy-assignment operator.
8242   ++ASTContext::NumImplicitMoveAssignmentOperatorsDeclared;
8243 
8244   // C++0x [class.copy]p9:
8245   //   If the definition of a class X does not explicitly declare a move
8246   //   assignment operator, one will be implicitly declared as defaulted if and
8247   //   only if:
8248   //   [...]
8249   //   - the move assignment operator would not be implicitly defined as
8250   //     deleted.
8251   if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
8252     // Cache this result so that we don't try to generate this over and over
8253     // on every lookup, leaking memory and wasting time.
8254     ClassDecl->setFailedImplicitMoveAssignment();
8255     return 0;
8256   }
8257 
8258   if (Scope *S = getScopeForContext(ClassDecl))
8259     PushOnScopeChains(MoveAssignment, S, false);
8260   ClassDecl->addDecl(MoveAssignment);
8261 
8262   AddOverriddenMethods(ClassDecl, MoveAssignment);
8263   return MoveAssignment;
8264 }
8265 
DefineImplicitMoveAssignment(SourceLocation CurrentLocation,CXXMethodDecl * MoveAssignOperator)8266 void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
8267                                         CXXMethodDecl *MoveAssignOperator) {
8268   assert((MoveAssignOperator->isDefaulted() &&
8269           MoveAssignOperator->isOverloadedOperator() &&
8270           MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
8271           !MoveAssignOperator->doesThisDeclarationHaveABody() &&
8272           !MoveAssignOperator->isDeleted()) &&
8273          "DefineImplicitMoveAssignment called for wrong function");
8274 
8275   CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
8276 
8277   if (ClassDecl->isInvalidDecl() || MoveAssignOperator->isInvalidDecl()) {
8278     MoveAssignOperator->setInvalidDecl();
8279     return;
8280   }
8281 
8282   MoveAssignOperator->setUsed();
8283 
8284   ImplicitlyDefinedFunctionScope Scope(*this, MoveAssignOperator);
8285   DiagnosticErrorTrap Trap(Diags);
8286 
8287   // C++0x [class.copy]p28:
8288   //   The implicitly-defined or move assignment operator for a non-union class
8289   //   X performs memberwise move assignment of its subobjects. The direct base
8290   //   classes of X are assigned first, in the order of their declaration in the
8291   //   base-specifier-list, and then the immediate non-static data members of X
8292   //   are assigned, in the order in which they were declared in the class
8293   //   definition.
8294 
8295   // The statements that form the synthesized function body.
8296   ASTOwningVector<Stmt*> Statements(*this);
8297 
8298   // The parameter for the "other" object, which we are move from.
8299   ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
8300   QualType OtherRefType = Other->getType()->
8301       getAs<RValueReferenceType>()->getPointeeType();
8302   assert(OtherRefType.getQualifiers() == 0 &&
8303          "Bad argument type of defaulted move assignment");
8304 
8305   // Our location for everything implicitly-generated.
8306   SourceLocation Loc = MoveAssignOperator->getLocation();
8307 
8308   // Construct a reference to the "other" object. We'll be using this
8309   // throughout the generated ASTs.
8310   Expr *OtherRef = BuildDeclRefExpr(Other, OtherRefType, VK_LValue, Loc).take();
8311   assert(OtherRef && "Reference to parameter cannot fail!");
8312   // Cast to rvalue.
8313   OtherRef = CastForMoving(*this, OtherRef);
8314 
8315   // Construct the "this" pointer. We'll be using this throughout the generated
8316   // ASTs.
8317   Expr *This = ActOnCXXThis(Loc).takeAs<Expr>();
8318   assert(This && "Reference to this cannot fail!");
8319 
8320   // Assign base classes.
8321   bool Invalid = false;
8322   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8323        E = ClassDecl->bases_end(); Base != E; ++Base) {
8324     // Form the assignment:
8325     //   static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
8326     QualType BaseType = Base->getType().getUnqualifiedType();
8327     if (!BaseType->isRecordType()) {
8328       Invalid = true;
8329       continue;
8330     }
8331 
8332     CXXCastPath BasePath;
8333     BasePath.push_back(Base);
8334 
8335     // Construct the "from" expression, which is an implicit cast to the
8336     // appropriately-qualified base type.
8337     Expr *From = OtherRef;
8338     From = ImpCastExprToType(From, BaseType, CK_UncheckedDerivedToBase,
8339                              VK_XValue, &BasePath).take();
8340 
8341     // Dereference "this".
8342     ExprResult To = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8343 
8344     // Implicitly cast "this" to the appropriately-qualified base type.
8345     To = ImpCastExprToType(To.take(),
8346                            Context.getCVRQualifiedType(BaseType,
8347                                      MoveAssignOperator->getTypeQualifiers()),
8348                            CK_UncheckedDerivedToBase,
8349                            VK_LValue, &BasePath);
8350 
8351     // Build the move.
8352     StmtResult Move = BuildSingleCopyAssign(*this, Loc, BaseType,
8353                                             To.get(), From,
8354                                             /*CopyingBaseSubobject=*/true,
8355                                             /*Copying=*/false);
8356     if (Move.isInvalid()) {
8357       Diag(CurrentLocation, diag::note_member_synthesized_at)
8358         << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8359       MoveAssignOperator->setInvalidDecl();
8360       return;
8361     }
8362 
8363     // Success! Record the move.
8364     Statements.push_back(Move.takeAs<Expr>());
8365   }
8366 
8367   // \brief Reference to the __builtin_memcpy function.
8368   Expr *BuiltinMemCpyRef = 0;
8369   // \brief Reference to the __builtin_objc_memmove_collectable function.
8370   Expr *CollectableMemCpyRef = 0;
8371 
8372   // Assign non-static members.
8373   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8374                                   FieldEnd = ClassDecl->field_end();
8375        Field != FieldEnd; ++Field) {
8376     if (Field->isUnnamedBitfield())
8377       continue;
8378 
8379     // Check for members of reference type; we can't move those.
8380     if (Field->getType()->isReferenceType()) {
8381       Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8382         << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
8383       Diag(Field->getLocation(), diag::note_declared_at);
8384       Diag(CurrentLocation, diag::note_member_synthesized_at)
8385         << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8386       Invalid = true;
8387       continue;
8388     }
8389 
8390     // Check for members of const-qualified, non-class type.
8391     QualType BaseType = Context.getBaseElementType(Field->getType());
8392     if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
8393       Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
8394         << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
8395       Diag(Field->getLocation(), diag::note_declared_at);
8396       Diag(CurrentLocation, diag::note_member_synthesized_at)
8397         << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8398       Invalid = true;
8399       continue;
8400     }
8401 
8402     // Suppress assigning zero-width bitfields.
8403     if (Field->isBitField() && Field->getBitWidthValue(Context) == 0)
8404       continue;
8405 
8406     QualType FieldType = Field->getType().getNonReferenceType();
8407     if (FieldType->isIncompleteArrayType()) {
8408       assert(ClassDecl->hasFlexibleArrayMember() &&
8409              "Incomplete array type is not valid");
8410       continue;
8411     }
8412 
8413     // Build references to the field in the object we're copying from and to.
8414     CXXScopeSpec SS; // Intentionally empty
8415     LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
8416                               LookupMemberName);
8417     MemberLookup.addDecl(*Field);
8418     MemberLookup.resolveKind();
8419     ExprResult From = BuildMemberReferenceExpr(OtherRef, OtherRefType,
8420                                                Loc, /*IsArrow=*/false,
8421                                                SS, SourceLocation(), 0,
8422                                                MemberLookup, 0);
8423     ExprResult To = BuildMemberReferenceExpr(This, This->getType(),
8424                                              Loc, /*IsArrow=*/true,
8425                                              SS, SourceLocation(), 0,
8426                                              MemberLookup, 0);
8427     assert(!From.isInvalid() && "Implicit field reference cannot fail");
8428     assert(!To.isInvalid() && "Implicit field reference cannot fail");
8429 
8430     assert(!From.get()->isLValue() && // could be xvalue or prvalue
8431         "Member reference with rvalue base must be rvalue except for reference "
8432         "members, which aren't allowed for move assignment.");
8433 
8434     // If the field should be copied with __builtin_memcpy rather than via
8435     // explicit assignments, do so. This optimization only applies for arrays
8436     // of scalars and arrays of class type with trivial move-assignment
8437     // operators.
8438     if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
8439         && BaseType.hasTrivialAssignment(Context, /*Copying=*/false)) {
8440       // Compute the size of the memory buffer to be copied.
8441       QualType SizeType = Context.getSizeType();
8442       llvm::APInt Size(Context.getTypeSize(SizeType),
8443                        Context.getTypeSizeInChars(BaseType).getQuantity());
8444       for (const ConstantArrayType *Array
8445               = Context.getAsConstantArrayType(FieldType);
8446            Array;
8447            Array = Context.getAsConstantArrayType(Array->getElementType())) {
8448         llvm::APInt ArraySize
8449           = Array->getSize().zextOrTrunc(Size.getBitWidth());
8450         Size *= ArraySize;
8451       }
8452 
8453       // Take the address of the field references for "from" and "to". We
8454       // directly construct UnaryOperators here because semantic analysis
8455       // does not permit us to take the address of an xvalue.
8456       From = new (Context) UnaryOperator(From.get(), UO_AddrOf,
8457                              Context.getPointerType(From.get()->getType()),
8458                              VK_RValue, OK_Ordinary, Loc);
8459       To = new (Context) UnaryOperator(To.get(), UO_AddrOf,
8460                            Context.getPointerType(To.get()->getType()),
8461                            VK_RValue, OK_Ordinary, Loc);
8462 
8463       bool NeedsCollectableMemCpy =
8464           (BaseType->isRecordType() &&
8465            BaseType->getAs<RecordType>()->getDecl()->hasObjectMember());
8466 
8467       if (NeedsCollectableMemCpy) {
8468         if (!CollectableMemCpyRef) {
8469           // Create a reference to the __builtin_objc_memmove_collectable function.
8470           LookupResult R(*this,
8471                          &Context.Idents.get("__builtin_objc_memmove_collectable"),
8472                          Loc, LookupOrdinaryName);
8473           LookupName(R, TUScope, true);
8474 
8475           FunctionDecl *CollectableMemCpy = R.getAsSingle<FunctionDecl>();
8476           if (!CollectableMemCpy) {
8477             // Something went horribly wrong earlier, and we will have
8478             // complained about it.
8479             Invalid = true;
8480             continue;
8481           }
8482 
8483           CollectableMemCpyRef = BuildDeclRefExpr(CollectableMemCpy,
8484                                                   CollectableMemCpy->getType(),
8485                                                   VK_LValue, Loc, 0).take();
8486           assert(CollectableMemCpyRef && "Builtin reference cannot fail");
8487         }
8488       }
8489       // Create a reference to the __builtin_memcpy builtin function.
8490       else if (!BuiltinMemCpyRef) {
8491         LookupResult R(*this, &Context.Idents.get("__builtin_memcpy"), Loc,
8492                        LookupOrdinaryName);
8493         LookupName(R, TUScope, true);
8494 
8495         FunctionDecl *BuiltinMemCpy = R.getAsSingle<FunctionDecl>();
8496         if (!BuiltinMemCpy) {
8497           // Something went horribly wrong earlier, and we will have complained
8498           // about it.
8499           Invalid = true;
8500           continue;
8501         }
8502 
8503         BuiltinMemCpyRef = BuildDeclRefExpr(BuiltinMemCpy,
8504                                             BuiltinMemCpy->getType(),
8505                                             VK_LValue, Loc, 0).take();
8506         assert(BuiltinMemCpyRef && "Builtin reference cannot fail");
8507       }
8508 
8509       ASTOwningVector<Expr*> CallArgs(*this);
8510       CallArgs.push_back(To.takeAs<Expr>());
8511       CallArgs.push_back(From.takeAs<Expr>());
8512       CallArgs.push_back(IntegerLiteral::Create(Context, Size, SizeType, Loc));
8513       ExprResult Call = ExprError();
8514       if (NeedsCollectableMemCpy)
8515         Call = ActOnCallExpr(/*Scope=*/0,
8516                              CollectableMemCpyRef,
8517                              Loc, move_arg(CallArgs),
8518                              Loc);
8519       else
8520         Call = ActOnCallExpr(/*Scope=*/0,
8521                              BuiltinMemCpyRef,
8522                              Loc, move_arg(CallArgs),
8523                              Loc);
8524 
8525       assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
8526       Statements.push_back(Call.takeAs<Expr>());
8527       continue;
8528     }
8529 
8530     // Build the move of this field.
8531     StmtResult Move = BuildSingleCopyAssign(*this, Loc, FieldType,
8532                                             To.get(), From.get(),
8533                                             /*CopyingBaseSubobject=*/false,
8534                                             /*Copying=*/false);
8535     if (Move.isInvalid()) {
8536       Diag(CurrentLocation, diag::note_member_synthesized_at)
8537         << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8538       MoveAssignOperator->setInvalidDecl();
8539       return;
8540     }
8541 
8542     // Success! Record the copy.
8543     Statements.push_back(Move.takeAs<Stmt>());
8544   }
8545 
8546   if (!Invalid) {
8547     // Add a "return *this;"
8548     ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
8549 
8550     StmtResult Return = ActOnReturnStmt(Loc, ThisObj.get());
8551     if (Return.isInvalid())
8552       Invalid = true;
8553     else {
8554       Statements.push_back(Return.takeAs<Stmt>());
8555 
8556       if (Trap.hasErrorOccurred()) {
8557         Diag(CurrentLocation, diag::note_member_synthesized_at)
8558           << CXXMoveAssignment << Context.getTagDeclType(ClassDecl);
8559         Invalid = true;
8560       }
8561     }
8562   }
8563 
8564   if (Invalid) {
8565     MoveAssignOperator->setInvalidDecl();
8566     return;
8567   }
8568 
8569   StmtResult Body;
8570   {
8571     CompoundScopeRAII CompoundScope(*this);
8572     Body = ActOnCompoundStmt(Loc, Loc, move_arg(Statements),
8573                              /*isStmtExpr=*/false);
8574     assert(!Body.isInvalid() && "Compound statement creation cannot fail");
8575   }
8576   MoveAssignOperator->setBody(Body.takeAs<Stmt>());
8577 
8578   if (ASTMutationListener *L = getASTMutationListener()) {
8579     L->CompletedImplicitDefinition(MoveAssignOperator);
8580   }
8581 }
8582 
8583 std::pair<Sema::ImplicitExceptionSpecification, bool>
ComputeDefaultedCopyCtorExceptionSpecAndConst(CXXRecordDecl * ClassDecl)8584 Sema::ComputeDefaultedCopyCtorExceptionSpecAndConst(CXXRecordDecl *ClassDecl) {
8585   if (ClassDecl->isInvalidDecl())
8586     return std::make_pair(ImplicitExceptionSpecification(*this), false);
8587 
8588   // C++ [class.copy]p5:
8589   //   The implicitly-declared copy constructor for a class X will
8590   //   have the form
8591   //
8592   //       X::X(const X&)
8593   //
8594   //   if
8595   // FIXME: It ought to be possible to store this on the record.
8596   bool HasConstCopyConstructor = true;
8597 
8598   //     -- each direct or virtual base class B of X has a copy
8599   //        constructor whose first parameter is of type const B& or
8600   //        const volatile B&, and
8601   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8602                                        BaseEnd = ClassDecl->bases_end();
8603        HasConstCopyConstructor && Base != BaseEnd;
8604        ++Base) {
8605     // Virtual bases are handled below.
8606     if (Base->isVirtual())
8607       continue;
8608 
8609     CXXRecordDecl *BaseClassDecl
8610       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8611     LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const,
8612                              &HasConstCopyConstructor);
8613   }
8614 
8615   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8616                                        BaseEnd = ClassDecl->vbases_end();
8617        HasConstCopyConstructor && Base != BaseEnd;
8618        ++Base) {
8619     CXXRecordDecl *BaseClassDecl
8620       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8621     LookupCopyingConstructor(BaseClassDecl, Qualifiers::Const,
8622                              &HasConstCopyConstructor);
8623   }
8624 
8625   //     -- for all the nonstatic data members of X that are of a
8626   //        class type M (or array thereof), each such class type
8627   //        has a copy constructor whose first parameter is of type
8628   //        const M& or const volatile M&.
8629   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8630                                   FieldEnd = ClassDecl->field_end();
8631        HasConstCopyConstructor && Field != FieldEnd;
8632        ++Field) {
8633     QualType FieldType = Context.getBaseElementType((*Field)->getType());
8634     if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8635       LookupCopyingConstructor(FieldClassDecl, Qualifiers::Const,
8636                                &HasConstCopyConstructor);
8637     }
8638   }
8639   //   Otherwise, the implicitly declared copy constructor will have
8640   //   the form
8641   //
8642   //       X::X(X&)
8643 
8644   // C++ [except.spec]p14:
8645   //   An implicitly declared special member function (Clause 12) shall have an
8646   //   exception-specification. [...]
8647   ImplicitExceptionSpecification ExceptSpec(*this);
8648   unsigned Quals = HasConstCopyConstructor? Qualifiers::Const : 0;
8649   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
8650                                        BaseEnd = ClassDecl->bases_end();
8651        Base != BaseEnd;
8652        ++Base) {
8653     // Virtual bases are handled below.
8654     if (Base->isVirtual())
8655       continue;
8656 
8657     CXXRecordDecl *BaseClassDecl
8658       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8659     if (CXXConstructorDecl *CopyConstructor =
8660           LookupCopyingConstructor(BaseClassDecl, Quals))
8661       ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8662   }
8663   for (CXXRecordDecl::base_class_iterator Base = ClassDecl->vbases_begin(),
8664                                        BaseEnd = ClassDecl->vbases_end();
8665        Base != BaseEnd;
8666        ++Base) {
8667     CXXRecordDecl *BaseClassDecl
8668       = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
8669     if (CXXConstructorDecl *CopyConstructor =
8670           LookupCopyingConstructor(BaseClassDecl, Quals))
8671       ExceptSpec.CalledDecl(Base->getLocStart(), CopyConstructor);
8672   }
8673   for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
8674                                   FieldEnd = ClassDecl->field_end();
8675        Field != FieldEnd;
8676        ++Field) {
8677     QualType FieldType = Context.getBaseElementType((*Field)->getType());
8678     if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) {
8679       if (CXXConstructorDecl *CopyConstructor =
8680         LookupCopyingConstructor(FieldClassDecl, Quals))
8681       ExceptSpec.CalledDecl(Field->getLocation(), CopyConstructor);
8682     }
8683   }
8684 
8685   return std::make_pair(ExceptSpec, HasConstCopyConstructor);
8686 }
8687 
DeclareImplicitCopyConstructor(CXXRecordDecl * ClassDecl)8688 CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
8689                                                     CXXRecordDecl *ClassDecl) {
8690   // C++ [class.copy]p4:
8691   //   If the class definition does not explicitly declare a copy
8692   //   constructor, one is declared implicitly.
8693 
8694   ImplicitExceptionSpecification Spec(*this);
8695   bool Const;
8696   llvm::tie(Spec, Const) =
8697     ComputeDefaultedCopyCtorExceptionSpecAndConst(ClassDecl);
8698 
8699   QualType ClassType = Context.getTypeDeclType(ClassDecl);
8700   QualType ArgType = ClassType;
8701   if (Const)
8702     ArgType = ArgType.withConst();
8703   ArgType = Context.getLValueReferenceType(ArgType);
8704 
8705   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8706 
8707   DeclarationName Name
8708     = Context.DeclarationNames.getCXXConstructorName(
8709                                            Context.getCanonicalType(ClassType));
8710   SourceLocation ClassLoc = ClassDecl->getLocation();
8711   DeclarationNameInfo NameInfo(Name, ClassLoc);
8712 
8713   //   An implicitly-declared copy constructor is an inline public
8714   //   member of its class.
8715   CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
8716       Context, ClassDecl, ClassLoc, NameInfo,
8717       Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI), /*TInfo=*/0,
8718       /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8719       /*isConstexpr=*/ClassDecl->defaultedCopyConstructorIsConstexpr() &&
8720         getLangOpts().CPlusPlus0x);
8721   CopyConstructor->setAccess(AS_public);
8722   CopyConstructor->setDefaulted();
8723   CopyConstructor->setTrivial(ClassDecl->hasTrivialCopyConstructor());
8724 
8725   // Note that we have declared this constructor.
8726   ++ASTContext::NumImplicitCopyConstructorsDeclared;
8727 
8728   // Add the parameter to the constructor.
8729   ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
8730                                                ClassLoc, ClassLoc,
8731                                                /*IdentifierInfo=*/0,
8732                                                ArgType, /*TInfo=*/0,
8733                                                SC_None,
8734                                                SC_None, 0);
8735   CopyConstructor->setParams(FromParam);
8736 
8737   if (Scope *S = getScopeForContext(ClassDecl))
8738     PushOnScopeChains(CopyConstructor, S, false);
8739   ClassDecl->addDecl(CopyConstructor);
8740 
8741   // C++11 [class.copy]p8:
8742   //   ... If the class definition does not explicitly declare a copy
8743   //   constructor, there is no user-declared move constructor, and there is no
8744   //   user-declared move assignment operator, a copy constructor is implicitly
8745   //   declared as defaulted.
8746   if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor))
8747     CopyConstructor->setDeletedAsWritten();
8748 
8749   return CopyConstructor;
8750 }
8751 
DefineImplicitCopyConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * CopyConstructor)8752 void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
8753                                    CXXConstructorDecl *CopyConstructor) {
8754   assert((CopyConstructor->isDefaulted() &&
8755           CopyConstructor->isCopyConstructor() &&
8756           !CopyConstructor->doesThisDeclarationHaveABody() &&
8757           !CopyConstructor->isDeleted()) &&
8758          "DefineImplicitCopyConstructor - call it for implicit copy ctor");
8759 
8760   CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
8761   assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
8762 
8763   ImplicitlyDefinedFunctionScope Scope(*this, CopyConstructor);
8764   DiagnosticErrorTrap Trap(Diags);
8765 
8766   if (SetCtorInitializers(CopyConstructor, 0, 0, /*AnyErrors=*/false) ||
8767       Trap.hasErrorOccurred()) {
8768     Diag(CurrentLocation, diag::note_member_synthesized_at)
8769       << CXXCopyConstructor << Context.getTagDeclType(ClassDecl);
8770     CopyConstructor->setInvalidDecl();
8771   }  else {
8772     Sema::CompoundScopeRAII CompoundScope(*this);
8773     CopyConstructor->setBody(ActOnCompoundStmt(CopyConstructor->getLocation(),
8774                                                CopyConstructor->getLocation(),
8775                                                MultiStmtArg(*this, 0, 0),
8776                                                /*isStmtExpr=*/false)
8777                                                               .takeAs<Stmt>());
8778     CopyConstructor->setImplicitlyDefined(true);
8779   }
8780 
8781   CopyConstructor->setUsed();
8782   if (ASTMutationListener *L = getASTMutationListener()) {
8783     L->CompletedImplicitDefinition(CopyConstructor);
8784   }
8785 }
8786 
8787 Sema::ImplicitExceptionSpecification
ComputeDefaultedMoveCtorExceptionSpec(CXXRecordDecl * ClassDecl)8788 Sema::ComputeDefaultedMoveCtorExceptionSpec(CXXRecordDecl *ClassDecl) {
8789   // C++ [except.spec]p14:
8790   //   An implicitly declared special member function (Clause 12) shall have an
8791   //   exception-specification. [...]
8792   ImplicitExceptionSpecification ExceptSpec(*this);
8793   if (ClassDecl->isInvalidDecl())
8794     return ExceptSpec;
8795 
8796   // Direct base-class constructors.
8797   for (CXXRecordDecl::base_class_iterator B = ClassDecl->bases_begin(),
8798                                        BEnd = ClassDecl->bases_end();
8799        B != BEnd; ++B) {
8800     if (B->isVirtual()) // Handled below.
8801       continue;
8802 
8803     if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8804       CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8805       CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl);
8806       // If this is a deleted function, add it anyway. This might be conformant
8807       // with the standard. This might not. I'm not sure. It might not matter.
8808       if (Constructor)
8809         ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8810     }
8811   }
8812 
8813   // Virtual base-class constructors.
8814   for (CXXRecordDecl::base_class_iterator B = ClassDecl->vbases_begin(),
8815                                        BEnd = ClassDecl->vbases_end();
8816        B != BEnd; ++B) {
8817     if (const RecordType *BaseType = B->getType()->getAs<RecordType>()) {
8818       CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
8819       CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl);
8820       // If this is a deleted function, add it anyway. This might be conformant
8821       // with the standard. This might not. I'm not sure. It might not matter.
8822       if (Constructor)
8823         ExceptSpec.CalledDecl(B->getLocStart(), Constructor);
8824     }
8825   }
8826 
8827   // Field constructors.
8828   for (RecordDecl::field_iterator F = ClassDecl->field_begin(),
8829                                FEnd = ClassDecl->field_end();
8830        F != FEnd; ++F) {
8831     if (const RecordType *RecordTy
8832               = Context.getBaseElementType(F->getType())->getAs<RecordType>()) {
8833       CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
8834       CXXConstructorDecl *Constructor = LookupMovingConstructor(FieldRecDecl);
8835       // If this is a deleted function, add it anyway. This might be conformant
8836       // with the standard. This might not. I'm not sure. It might not matter.
8837       // In particular, the problem is that this function never gets called. It
8838       // might just be ill-formed because this function attempts to refer to
8839       // a deleted function here.
8840       if (Constructor)
8841         ExceptSpec.CalledDecl(F->getLocation(), Constructor);
8842     }
8843   }
8844 
8845   return ExceptSpec;
8846 }
8847 
DeclareImplicitMoveConstructor(CXXRecordDecl * ClassDecl)8848 CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
8849                                                     CXXRecordDecl *ClassDecl) {
8850   // C++11 [class.copy]p9:
8851   //   If the definition of a class X does not explicitly declare a move
8852   //   constructor, one will be implicitly declared as defaulted if and only if:
8853   //
8854   //   - [first 4 bullets]
8855   assert(ClassDecl->needsImplicitMoveConstructor());
8856 
8857   // [Checked after we build the declaration]
8858   //   - the move assignment operator would not be implicitly defined as
8859   //     deleted,
8860 
8861   // [DR1402]:
8862   //   - each of X's non-static data members and direct or virtual base classes
8863   //     has a type that either has a move constructor or is trivially copyable.
8864   if (!subobjectsHaveMoveOrTrivialCopy(*this, ClassDecl, /*Constructor*/true)) {
8865     ClassDecl->setFailedImplicitMoveConstructor();
8866     return 0;
8867   }
8868 
8869   ImplicitExceptionSpecification Spec(
8870       ComputeDefaultedMoveCtorExceptionSpec(ClassDecl));
8871 
8872   QualType ClassType = Context.getTypeDeclType(ClassDecl);
8873   QualType ArgType = Context.getRValueReferenceType(ClassType);
8874 
8875   FunctionProtoType::ExtProtoInfo EPI = Spec.getEPI();
8876 
8877   DeclarationName Name
8878     = Context.DeclarationNames.getCXXConstructorName(
8879                                            Context.getCanonicalType(ClassType));
8880   SourceLocation ClassLoc = ClassDecl->getLocation();
8881   DeclarationNameInfo NameInfo(Name, ClassLoc);
8882 
8883   // C++0x [class.copy]p11:
8884   //   An implicitly-declared copy/move constructor is an inline public
8885   //   member of its class.
8886   CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
8887       Context, ClassDecl, ClassLoc, NameInfo,
8888       Context.getFunctionType(Context.VoidTy, &ArgType, 1, EPI), /*TInfo=*/0,
8889       /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true,
8890       /*isConstexpr=*/ClassDecl->defaultedMoveConstructorIsConstexpr() &&
8891         getLangOpts().CPlusPlus0x);
8892   MoveConstructor->setAccess(AS_public);
8893   MoveConstructor->setDefaulted();
8894   MoveConstructor->setTrivial(ClassDecl->hasTrivialMoveConstructor());
8895 
8896   // Add the parameter to the constructor.
8897   ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
8898                                                ClassLoc, ClassLoc,
8899                                                /*IdentifierInfo=*/0,
8900                                                ArgType, /*TInfo=*/0,
8901                                                SC_None,
8902                                                SC_None, 0);
8903   MoveConstructor->setParams(FromParam);
8904 
8905   // C++0x [class.copy]p9:
8906   //   If the definition of a class X does not explicitly declare a move
8907   //   constructor, one will be implicitly declared as defaulted if and only if:
8908   //   [...]
8909   //   - the move constructor would not be implicitly defined as deleted.
8910   if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
8911     // Cache this result so that we don't try to generate this over and over
8912     // on every lookup, leaking memory and wasting time.
8913     ClassDecl->setFailedImplicitMoveConstructor();
8914     return 0;
8915   }
8916 
8917   // Note that we have declared this constructor.
8918   ++ASTContext::NumImplicitMoveConstructorsDeclared;
8919 
8920   if (Scope *S = getScopeForContext(ClassDecl))
8921     PushOnScopeChains(MoveConstructor, S, false);
8922   ClassDecl->addDecl(MoveConstructor);
8923 
8924   return MoveConstructor;
8925 }
8926 
DefineImplicitMoveConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * MoveConstructor)8927 void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
8928                                    CXXConstructorDecl *MoveConstructor) {
8929   assert((MoveConstructor->isDefaulted() &&
8930           MoveConstructor->isMoveConstructor() &&
8931           !MoveConstructor->doesThisDeclarationHaveABody() &&
8932           !MoveConstructor->isDeleted()) &&
8933          "DefineImplicitMoveConstructor - call it for implicit move ctor");
8934 
8935   CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
8936   assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
8937 
8938   ImplicitlyDefinedFunctionScope Scope(*this, MoveConstructor);
8939   DiagnosticErrorTrap Trap(Diags);
8940 
8941   if (SetCtorInitializers(MoveConstructor, 0, 0, /*AnyErrors=*/false) ||
8942       Trap.hasErrorOccurred()) {
8943     Diag(CurrentLocation, diag::note_member_synthesized_at)
8944       << CXXMoveConstructor << Context.getTagDeclType(ClassDecl);
8945     MoveConstructor->setInvalidDecl();
8946   }  else {
8947     Sema::CompoundScopeRAII CompoundScope(*this);
8948     MoveConstructor->setBody(ActOnCompoundStmt(MoveConstructor->getLocation(),
8949                                                MoveConstructor->getLocation(),
8950                                                MultiStmtArg(*this, 0, 0),
8951                                                /*isStmtExpr=*/false)
8952                                                               .takeAs<Stmt>());
8953     MoveConstructor->setImplicitlyDefined(true);
8954   }
8955 
8956   MoveConstructor->setUsed();
8957 
8958   if (ASTMutationListener *L = getASTMutationListener()) {
8959     L->CompletedImplicitDefinition(MoveConstructor);
8960   }
8961 }
8962 
isImplicitlyDeleted(FunctionDecl * FD)8963 bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
8964   return FD->isDeleted() &&
8965          (FD->isDefaulted() || FD->isImplicit()) &&
8966          isa<CXXMethodDecl>(FD);
8967 }
8968 
8969 /// \brief Mark the call operator of the given lambda closure type as "used".
markLambdaCallOperatorUsed(Sema & S,CXXRecordDecl * Lambda)8970 static void markLambdaCallOperatorUsed(Sema &S, CXXRecordDecl *Lambda) {
8971   CXXMethodDecl *CallOperator
8972     = cast<CXXMethodDecl>(
8973         *Lambda->lookup(
8974           S.Context.DeclarationNames.getCXXOperatorName(OO_Call)).first);
8975   CallOperator->setReferenced();
8976   CallOperator->setUsed();
8977 }
8978 
DefineImplicitLambdaToFunctionPointerConversion(SourceLocation CurrentLocation,CXXConversionDecl * Conv)8979 void Sema::DefineImplicitLambdaToFunctionPointerConversion(
8980        SourceLocation CurrentLocation,
8981        CXXConversionDecl *Conv)
8982 {
8983   CXXRecordDecl *Lambda = Conv->getParent();
8984 
8985   // Make sure that the lambda call operator is marked used.
8986   markLambdaCallOperatorUsed(*this, Lambda);
8987 
8988   Conv->setUsed();
8989 
8990   ImplicitlyDefinedFunctionScope Scope(*this, Conv);
8991   DiagnosticErrorTrap Trap(Diags);
8992 
8993   // Return the address of the __invoke function.
8994   DeclarationName InvokeName = &Context.Idents.get("__invoke");
8995   CXXMethodDecl *Invoke
8996     = cast<CXXMethodDecl>(*Lambda->lookup(InvokeName).first);
8997   Expr *FunctionRef = BuildDeclRefExpr(Invoke, Invoke->getType(),
8998                                        VK_LValue, Conv->getLocation()).take();
8999   assert(FunctionRef && "Can't refer to __invoke function?");
9000   Stmt *Return = ActOnReturnStmt(Conv->getLocation(), FunctionRef).take();
9001   Conv->setBody(new (Context) CompoundStmt(Context, &Return, 1,
9002                                            Conv->getLocation(),
9003                                            Conv->getLocation()));
9004 
9005   // Fill in the __invoke function with a dummy implementation. IR generation
9006   // will fill in the actual details.
9007   Invoke->setUsed();
9008   Invoke->setReferenced();
9009   Invoke->setBody(new (Context) CompoundStmt(Context, 0, 0, Conv->getLocation(),
9010                                              Conv->getLocation()));
9011 
9012   if (ASTMutationListener *L = getASTMutationListener()) {
9013     L->CompletedImplicitDefinition(Conv);
9014     L->CompletedImplicitDefinition(Invoke);
9015   }
9016 }
9017 
DefineImplicitLambdaToBlockPointerConversion(SourceLocation CurrentLocation,CXXConversionDecl * Conv)9018 void Sema::DefineImplicitLambdaToBlockPointerConversion(
9019        SourceLocation CurrentLocation,
9020        CXXConversionDecl *Conv)
9021 {
9022   Conv->setUsed();
9023 
9024   ImplicitlyDefinedFunctionScope Scope(*this, Conv);
9025   DiagnosticErrorTrap Trap(Diags);
9026 
9027   // Copy-initialize the lambda object as needed to capture it.
9028   Expr *This = ActOnCXXThis(CurrentLocation).take();
9029   Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).take();
9030 
9031   ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
9032                                                         Conv->getLocation(),
9033                                                         Conv, DerefThis);
9034 
9035   // If we're not under ARC, make sure we still get the _Block_copy/autorelease
9036   // behavior.  Note that only the general conversion function does this
9037   // (since it's unusable otherwise); in the case where we inline the
9038   // block literal, it has block literal lifetime semantics.
9039   if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
9040     BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(),
9041                                           CK_CopyAndAutoreleaseBlockObject,
9042                                           BuildBlock.get(), 0, VK_RValue);
9043 
9044   if (BuildBlock.isInvalid()) {
9045     Diag(CurrentLocation, diag::note_lambda_to_block_conv);
9046     Conv->setInvalidDecl();
9047     return;
9048   }
9049 
9050   // Create the return statement that returns the block from the conversion
9051   // function.
9052   StmtResult Return = ActOnReturnStmt(Conv->getLocation(), BuildBlock.get());
9053   if (Return.isInvalid()) {
9054     Diag(CurrentLocation, diag::note_lambda_to_block_conv);
9055     Conv->setInvalidDecl();
9056     return;
9057   }
9058 
9059   // Set the body of the conversion function.
9060   Stmt *ReturnS = Return.take();
9061   Conv->setBody(new (Context) CompoundStmt(Context, &ReturnS, 1,
9062                                            Conv->getLocation(),
9063                                            Conv->getLocation()));
9064 
9065   // We're done; notify the mutation listener, if any.
9066   if (ASTMutationListener *L = getASTMutationListener()) {
9067     L->CompletedImplicitDefinition(Conv);
9068   }
9069 }
9070 
9071 /// \brief Determine whether the given list arguments contains exactly one
9072 /// "real" (non-default) argument.
hasOneRealArgument(MultiExprArg Args)9073 static bool hasOneRealArgument(MultiExprArg Args) {
9074   switch (Args.size()) {
9075   case 0:
9076     return false;
9077 
9078   default:
9079     if (!Args.get()[1]->isDefaultArgument())
9080       return false;
9081 
9082     // fall through
9083   case 1:
9084     return !Args.get()[0]->isDefaultArgument();
9085   }
9086 
9087   return false;
9088 }
9089 
9090 ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc,QualType DeclInitType,CXXConstructorDecl * Constructor,MultiExprArg ExprArgs,bool HadMultipleCandidates,bool RequiresZeroInit,unsigned ConstructKind,SourceRange ParenRange)9091 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
9092                             CXXConstructorDecl *Constructor,
9093                             MultiExprArg ExprArgs,
9094                             bool HadMultipleCandidates,
9095                             bool RequiresZeroInit,
9096                             unsigned ConstructKind,
9097                             SourceRange ParenRange) {
9098   bool Elidable = false;
9099 
9100   // C++0x [class.copy]p34:
9101   //   When certain criteria are met, an implementation is allowed to
9102   //   omit the copy/move construction of a class object, even if the
9103   //   copy/move constructor and/or destructor for the object have
9104   //   side effects. [...]
9105   //     - when a temporary class object that has not been bound to a
9106   //       reference (12.2) would be copied/moved to a class object
9107   //       with the same cv-unqualified type, the copy/move operation
9108   //       can be omitted by constructing the temporary object
9109   //       directly into the target of the omitted copy/move
9110   if (ConstructKind == CXXConstructExpr::CK_Complete &&
9111       Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
9112     Expr *SubExpr = ((Expr **)ExprArgs.get())[0];
9113     Elidable = SubExpr->isTemporaryObject(Context, Constructor->getParent());
9114   }
9115 
9116   return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor,
9117                                Elidable, move(ExprArgs), HadMultipleCandidates,
9118                                RequiresZeroInit, ConstructKind, ParenRange);
9119 }
9120 
9121 /// BuildCXXConstructExpr - Creates a complete call to a constructor,
9122 /// including handling of its default argument expressions.
9123 ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc,QualType DeclInitType,CXXConstructorDecl * Constructor,bool Elidable,MultiExprArg ExprArgs,bool HadMultipleCandidates,bool RequiresZeroInit,unsigned ConstructKind,SourceRange ParenRange)9124 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
9125                             CXXConstructorDecl *Constructor, bool Elidable,
9126                             MultiExprArg ExprArgs,
9127                             bool HadMultipleCandidates,
9128                             bool RequiresZeroInit,
9129                             unsigned ConstructKind,
9130                             SourceRange ParenRange) {
9131   unsigned NumExprs = ExprArgs.size();
9132   Expr **Exprs = (Expr **)ExprArgs.release();
9133 
9134   for (specific_attr_iterator<NonNullAttr>
9135            i = Constructor->specific_attr_begin<NonNullAttr>(),
9136            e = Constructor->specific_attr_end<NonNullAttr>(); i != e; ++i) {
9137     const NonNullAttr *NonNull = *i;
9138     CheckNonNullArguments(NonNull, ExprArgs.get(), ConstructLoc);
9139   }
9140 
9141   MarkFunctionReferenced(ConstructLoc, Constructor);
9142   return Owned(CXXConstructExpr::Create(Context, DeclInitType, ConstructLoc,
9143                                         Constructor, Elidable, Exprs, NumExprs,
9144                                         HadMultipleCandidates, /*FIXME*/false,
9145                                         RequiresZeroInit,
9146               static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
9147                                         ParenRange));
9148 }
9149 
InitializeVarWithConstructor(VarDecl * VD,CXXConstructorDecl * Constructor,MultiExprArg Exprs,bool HadMultipleCandidates)9150 bool Sema::InitializeVarWithConstructor(VarDecl *VD,
9151                                         CXXConstructorDecl *Constructor,
9152                                         MultiExprArg Exprs,
9153                                         bool HadMultipleCandidates) {
9154   // FIXME: Provide the correct paren SourceRange when available.
9155   ExprResult TempResult =
9156     BuildCXXConstructExpr(VD->getLocation(), VD->getType(), Constructor,
9157                           move(Exprs), HadMultipleCandidates, false,
9158                           CXXConstructExpr::CK_Complete, SourceRange());
9159   if (TempResult.isInvalid())
9160     return true;
9161 
9162   Expr *Temp = TempResult.takeAs<Expr>();
9163   CheckImplicitConversions(Temp, VD->getLocation());
9164   MarkFunctionReferenced(VD->getLocation(), Constructor);
9165   Temp = MaybeCreateExprWithCleanups(Temp);
9166   VD->setInit(Temp);
9167 
9168   return false;
9169 }
9170 
FinalizeVarWithDestructor(VarDecl * VD,const RecordType * Record)9171 void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
9172   if (VD->isInvalidDecl()) return;
9173 
9174   CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
9175   if (ClassDecl->isInvalidDecl()) return;
9176   if (ClassDecl->hasIrrelevantDestructor()) return;
9177   if (ClassDecl->isDependentContext()) return;
9178 
9179   CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
9180   MarkFunctionReferenced(VD->getLocation(), Destructor);
9181   CheckDestructorAccess(VD->getLocation(), Destructor,
9182                         PDiag(diag::err_access_dtor_var)
9183                         << VD->getDeclName()
9184                         << VD->getType());
9185   DiagnoseUseOfDecl(Destructor, VD->getLocation());
9186 
9187   if (!VD->hasGlobalStorage()) return;
9188 
9189   // Emit warning for non-trivial dtor in global scope (a real global,
9190   // class-static, function-static).
9191   Diag(VD->getLocation(), diag::warn_exit_time_destructor);
9192 
9193   // TODO: this should be re-enabled for static locals by !CXAAtExit
9194   if (!VD->isStaticLocal())
9195     Diag(VD->getLocation(), diag::warn_global_destructor);
9196 }
9197 
9198 /// \brief Given a constructor and the set of arguments provided for the
9199 /// constructor, convert the arguments and add any required default arguments
9200 /// to form a proper call to this constructor.
9201 ///
9202 /// \returns true if an error occurred, false otherwise.
9203 bool
CompleteConstructorCall(CXXConstructorDecl * Constructor,MultiExprArg ArgsPtr,SourceLocation Loc,ASTOwningVector<Expr * > & ConvertedArgs,bool AllowExplicit)9204 Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
9205                               MultiExprArg ArgsPtr,
9206                               SourceLocation Loc,
9207                               ASTOwningVector<Expr*> &ConvertedArgs,
9208                               bool AllowExplicit) {
9209   // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
9210   unsigned NumArgs = ArgsPtr.size();
9211   Expr **Args = (Expr **)ArgsPtr.get();
9212 
9213   const FunctionProtoType *Proto
9214     = Constructor->getType()->getAs<FunctionProtoType>();
9215   assert(Proto && "Constructor without a prototype?");
9216   unsigned NumArgsInProto = Proto->getNumArgs();
9217 
9218   // If too few arguments are available, we'll fill in the rest with defaults.
9219   if (NumArgs < NumArgsInProto)
9220     ConvertedArgs.reserve(NumArgsInProto);
9221   else
9222     ConvertedArgs.reserve(NumArgs);
9223 
9224   VariadicCallType CallType =
9225     Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
9226   SmallVector<Expr *, 8> AllArgs;
9227   bool Invalid = GatherArgumentsForCall(Loc, Constructor,
9228                                         Proto, 0, Args, NumArgs, AllArgs,
9229                                         CallType, AllowExplicit);
9230   ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
9231 
9232   DiagnoseSentinelCalls(Constructor, Loc, AllArgs.data(), AllArgs.size());
9233 
9234   // FIXME: Missing call to CheckFunctionCall or equivalent
9235 
9236   return Invalid;
9237 }
9238 
9239 static inline bool
CheckOperatorNewDeleteDeclarationScope(Sema & SemaRef,const FunctionDecl * FnDecl)9240 CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
9241                                        const FunctionDecl *FnDecl) {
9242   const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
9243   if (isa<NamespaceDecl>(DC)) {
9244     return SemaRef.Diag(FnDecl->getLocation(),
9245                         diag::err_operator_new_delete_declared_in_namespace)
9246       << FnDecl->getDeclName();
9247   }
9248 
9249   if (isa<TranslationUnitDecl>(DC) &&
9250       FnDecl->getStorageClass() == SC_Static) {
9251     return SemaRef.Diag(FnDecl->getLocation(),
9252                         diag::err_operator_new_delete_declared_static)
9253       << FnDecl->getDeclName();
9254   }
9255 
9256   return false;
9257 }
9258 
9259 static inline bool
CheckOperatorNewDeleteTypes(Sema & SemaRef,const FunctionDecl * FnDecl,CanQualType ExpectedResultType,CanQualType ExpectedFirstParamType,unsigned DependentParamTypeDiag,unsigned InvalidParamTypeDiag)9260 CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
9261                             CanQualType ExpectedResultType,
9262                             CanQualType ExpectedFirstParamType,
9263                             unsigned DependentParamTypeDiag,
9264                             unsigned InvalidParamTypeDiag) {
9265   QualType ResultType =
9266     FnDecl->getType()->getAs<FunctionType>()->getResultType();
9267 
9268   // Check that the result type is not dependent.
9269   if (ResultType->isDependentType())
9270     return SemaRef.Diag(FnDecl->getLocation(),
9271                         diag::err_operator_new_delete_dependent_result_type)
9272     << FnDecl->getDeclName() << ExpectedResultType;
9273 
9274   // Check that the result type is what we expect.
9275   if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
9276     return SemaRef.Diag(FnDecl->getLocation(),
9277                         diag::err_operator_new_delete_invalid_result_type)
9278     << FnDecl->getDeclName() << ExpectedResultType;
9279 
9280   // A function template must have at least 2 parameters.
9281   if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
9282     return SemaRef.Diag(FnDecl->getLocation(),
9283                       diag::err_operator_new_delete_template_too_few_parameters)
9284         << FnDecl->getDeclName();
9285 
9286   // The function decl must have at least 1 parameter.
9287   if (FnDecl->getNumParams() == 0)
9288     return SemaRef.Diag(FnDecl->getLocation(),
9289                         diag::err_operator_new_delete_too_few_parameters)
9290       << FnDecl->getDeclName();
9291 
9292   // Check the the first parameter type is not dependent.
9293   QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
9294   if (FirstParamType->isDependentType())
9295     return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
9296       << FnDecl->getDeclName() << ExpectedFirstParamType;
9297 
9298   // Check that the first parameter type is what we expect.
9299   if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
9300       ExpectedFirstParamType)
9301     return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
9302     << FnDecl->getDeclName() << ExpectedFirstParamType;
9303 
9304   return false;
9305 }
9306 
9307 static bool
CheckOperatorNewDeclaration(Sema & SemaRef,const FunctionDecl * FnDecl)9308 CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9309   // C++ [basic.stc.dynamic.allocation]p1:
9310   //   A program is ill-formed if an allocation function is declared in a
9311   //   namespace scope other than global scope or declared static in global
9312   //   scope.
9313   if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9314     return true;
9315 
9316   CanQualType SizeTy =
9317     SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
9318 
9319   // C++ [basic.stc.dynamic.allocation]p1:
9320   //  The return type shall be void*. The first parameter shall have type
9321   //  std::size_t.
9322   if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
9323                                   SizeTy,
9324                                   diag::err_operator_new_dependent_param_type,
9325                                   diag::err_operator_new_param_type))
9326     return true;
9327 
9328   // C++ [basic.stc.dynamic.allocation]p1:
9329   //  The first parameter shall not have an associated default argument.
9330   if (FnDecl->getParamDecl(0)->hasDefaultArg())
9331     return SemaRef.Diag(FnDecl->getLocation(),
9332                         diag::err_operator_new_default_arg)
9333       << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
9334 
9335   return false;
9336 }
9337 
9338 static bool
CheckOperatorDeleteDeclaration(Sema & SemaRef,const FunctionDecl * FnDecl)9339 CheckOperatorDeleteDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
9340   // C++ [basic.stc.dynamic.deallocation]p1:
9341   //   A program is ill-formed if deallocation functions are declared in a
9342   //   namespace scope other than global scope or declared static in global
9343   //   scope.
9344   if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
9345     return true;
9346 
9347   // C++ [basic.stc.dynamic.deallocation]p2:
9348   //   Each deallocation function shall return void and its first parameter
9349   //   shall be void*.
9350   if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy,
9351                                   SemaRef.Context.VoidPtrTy,
9352                                  diag::err_operator_delete_dependent_param_type,
9353                                  diag::err_operator_delete_param_type))
9354     return true;
9355 
9356   return false;
9357 }
9358 
9359 /// CheckOverloadedOperatorDeclaration - Check whether the declaration
9360 /// of this overloaded operator is well-formed. If so, returns false;
9361 /// otherwise, emits appropriate diagnostics and returns true.
CheckOverloadedOperatorDeclaration(FunctionDecl * FnDecl)9362 bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
9363   assert(FnDecl && FnDecl->isOverloadedOperator() &&
9364          "Expected an overloaded operator declaration");
9365 
9366   OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
9367 
9368   // C++ [over.oper]p5:
9369   //   The allocation and deallocation functions, operator new,
9370   //   operator new[], operator delete and operator delete[], are
9371   //   described completely in 3.7.3. The attributes and restrictions
9372   //   found in the rest of this subclause do not apply to them unless
9373   //   explicitly stated in 3.7.3.
9374   if (Op == OO_Delete || Op == OO_Array_Delete)
9375     return CheckOperatorDeleteDeclaration(*this, FnDecl);
9376 
9377   if (Op == OO_New || Op == OO_Array_New)
9378     return CheckOperatorNewDeclaration(*this, FnDecl);
9379 
9380   // C++ [over.oper]p6:
9381   //   An operator function shall either be a non-static member
9382   //   function or be a non-member function and have at least one
9383   //   parameter whose type is a class, a reference to a class, an
9384   //   enumeration, or a reference to an enumeration.
9385   if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
9386     if (MethodDecl->isStatic())
9387       return Diag(FnDecl->getLocation(),
9388                   diag::err_operator_overload_static) << FnDecl->getDeclName();
9389   } else {
9390     bool ClassOrEnumParam = false;
9391     for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9392                                    ParamEnd = FnDecl->param_end();
9393          Param != ParamEnd; ++Param) {
9394       QualType ParamType = (*Param)->getType().getNonReferenceType();
9395       if (ParamType->isDependentType() || ParamType->isRecordType() ||
9396           ParamType->isEnumeralType()) {
9397         ClassOrEnumParam = true;
9398         break;
9399       }
9400     }
9401 
9402     if (!ClassOrEnumParam)
9403       return Diag(FnDecl->getLocation(),
9404                   diag::err_operator_overload_needs_class_or_enum)
9405         << FnDecl->getDeclName();
9406   }
9407 
9408   // C++ [over.oper]p8:
9409   //   An operator function cannot have default arguments (8.3.6),
9410   //   except where explicitly stated below.
9411   //
9412   // Only the function-call operator allows default arguments
9413   // (C++ [over.call]p1).
9414   if (Op != OO_Call) {
9415     for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
9416          Param != FnDecl->param_end(); ++Param) {
9417       if ((*Param)->hasDefaultArg())
9418         return Diag((*Param)->getLocation(),
9419                     diag::err_operator_overload_default_arg)
9420           << FnDecl->getDeclName() << (*Param)->getDefaultArgRange();
9421     }
9422   }
9423 
9424   static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
9425     { false, false, false }
9426 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
9427     , { Unary, Binary, MemberOnly }
9428 #include "clang/Basic/OperatorKinds.def"
9429   };
9430 
9431   bool CanBeUnaryOperator = OperatorUses[Op][0];
9432   bool CanBeBinaryOperator = OperatorUses[Op][1];
9433   bool MustBeMemberOperator = OperatorUses[Op][2];
9434 
9435   // C++ [over.oper]p8:
9436   //   [...] Operator functions cannot have more or fewer parameters
9437   //   than the number required for the corresponding operator, as
9438   //   described in the rest of this subclause.
9439   unsigned NumParams = FnDecl->getNumParams()
9440                      + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
9441   if (Op != OO_Call &&
9442       ((NumParams == 1 && !CanBeUnaryOperator) ||
9443        (NumParams == 2 && !CanBeBinaryOperator) ||
9444        (NumParams < 1) || (NumParams > 2))) {
9445     // We have the wrong number of parameters.
9446     unsigned ErrorKind;
9447     if (CanBeUnaryOperator && CanBeBinaryOperator) {
9448       ErrorKind = 2;  // 2 -> unary or binary.
9449     } else if (CanBeUnaryOperator) {
9450       ErrorKind = 0;  // 0 -> unary
9451     } else {
9452       assert(CanBeBinaryOperator &&
9453              "All non-call overloaded operators are unary or binary!");
9454       ErrorKind = 1;  // 1 -> binary
9455     }
9456 
9457     return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
9458       << FnDecl->getDeclName() << NumParams << ErrorKind;
9459   }
9460 
9461   // Overloaded operators other than operator() cannot be variadic.
9462   if (Op != OO_Call &&
9463       FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
9464     return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
9465       << FnDecl->getDeclName();
9466   }
9467 
9468   // Some operators must be non-static member functions.
9469   if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
9470     return Diag(FnDecl->getLocation(),
9471                 diag::err_operator_overload_must_be_member)
9472       << FnDecl->getDeclName();
9473   }
9474 
9475   // C++ [over.inc]p1:
9476   //   The user-defined function called operator++ implements the
9477   //   prefix and postfix ++ operator. If this function is a member
9478   //   function with no parameters, or a non-member function with one
9479   //   parameter of class or enumeration type, it defines the prefix
9480   //   increment operator ++ for objects of that type. If the function
9481   //   is a member function with one parameter (which shall be of type
9482   //   int) or a non-member function with two parameters (the second
9483   //   of which shall be of type int), it defines the postfix
9484   //   increment operator ++ for objects of that type.
9485   if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
9486     ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
9487     bool ParamIsInt = false;
9488     if (const BuiltinType *BT = LastParam->getType()->getAs<BuiltinType>())
9489       ParamIsInt = BT->getKind() == BuiltinType::Int;
9490 
9491     if (!ParamIsInt)
9492       return Diag(LastParam->getLocation(),
9493                   diag::err_operator_overload_post_incdec_must_be_int)
9494         << LastParam->getType() << (Op == OO_MinusMinus);
9495   }
9496 
9497   return false;
9498 }
9499 
9500 /// CheckLiteralOperatorDeclaration - Check whether the declaration
9501 /// of this literal operator function is well-formed. If so, returns
9502 /// false; otherwise, emits appropriate diagnostics and returns true.
CheckLiteralOperatorDeclaration(FunctionDecl * FnDecl)9503 bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
9504   if (isa<CXXMethodDecl>(FnDecl)) {
9505     Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
9506       << FnDecl->getDeclName();
9507     return true;
9508   }
9509 
9510   if (FnDecl->isExternC()) {
9511     Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
9512     return true;
9513   }
9514 
9515   bool Valid = false;
9516 
9517   // This might be the definition of a literal operator template.
9518   FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
9519   // This might be a specialization of a literal operator template.
9520   if (!TpDecl)
9521     TpDecl = FnDecl->getPrimaryTemplate();
9522 
9523   // template <char...> type operator "" name() is the only valid template
9524   // signature, and the only valid signature with no parameters.
9525   if (TpDecl) {
9526     if (FnDecl->param_size() == 0) {
9527       // Must have only one template parameter
9528       TemplateParameterList *Params = TpDecl->getTemplateParameters();
9529       if (Params->size() == 1) {
9530         NonTypeTemplateParmDecl *PmDecl =
9531           cast<NonTypeTemplateParmDecl>(Params->getParam(0));
9532 
9533         // The template parameter must be a char parameter pack.
9534         if (PmDecl && PmDecl->isTemplateParameterPack() &&
9535             Context.hasSameType(PmDecl->getType(), Context.CharTy))
9536           Valid = true;
9537       }
9538     }
9539   } else if (FnDecl->param_size()) {
9540     // Check the first parameter
9541     FunctionDecl::param_iterator Param = FnDecl->param_begin();
9542 
9543     QualType T = (*Param)->getType().getUnqualifiedType();
9544 
9545     // unsigned long long int, long double, and any character type are allowed
9546     // as the only parameters.
9547     if (Context.hasSameType(T, Context.UnsignedLongLongTy) ||
9548         Context.hasSameType(T, Context.LongDoubleTy) ||
9549         Context.hasSameType(T, Context.CharTy) ||
9550         Context.hasSameType(T, Context.WCharTy) ||
9551         Context.hasSameType(T, Context.Char16Ty) ||
9552         Context.hasSameType(T, Context.Char32Ty)) {
9553       if (++Param == FnDecl->param_end())
9554         Valid = true;
9555       goto FinishedParams;
9556     }
9557 
9558     // Otherwise it must be a pointer to const; let's strip those qualifiers.
9559     const PointerType *PT = T->getAs<PointerType>();
9560     if (!PT)
9561       goto FinishedParams;
9562     T = PT->getPointeeType();
9563     if (!T.isConstQualified() || T.isVolatileQualified())
9564       goto FinishedParams;
9565     T = T.getUnqualifiedType();
9566 
9567     // Move on to the second parameter;
9568     ++Param;
9569 
9570     // If there is no second parameter, the first must be a const char *
9571     if (Param == FnDecl->param_end()) {
9572       if (Context.hasSameType(T, Context.CharTy))
9573         Valid = true;
9574       goto FinishedParams;
9575     }
9576 
9577     // const char *, const wchar_t*, const char16_t*, and const char32_t*
9578     // are allowed as the first parameter to a two-parameter function
9579     if (!(Context.hasSameType(T, Context.CharTy) ||
9580           Context.hasSameType(T, Context.WCharTy) ||
9581           Context.hasSameType(T, Context.Char16Ty) ||
9582           Context.hasSameType(T, Context.Char32Ty)))
9583       goto FinishedParams;
9584 
9585     // The second and final parameter must be an std::size_t
9586     T = (*Param)->getType().getUnqualifiedType();
9587     if (Context.hasSameType(T, Context.getSizeType()) &&
9588         ++Param == FnDecl->param_end())
9589       Valid = true;
9590   }
9591 
9592   // FIXME: This diagnostic is absolutely terrible.
9593 FinishedParams:
9594   if (!Valid) {
9595     Diag(FnDecl->getLocation(), diag::err_literal_operator_params)
9596       << FnDecl->getDeclName();
9597     return true;
9598   }
9599 
9600   // A parameter-declaration-clause containing a default argument is not
9601   // equivalent to any of the permitted forms.
9602   for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
9603                                     ParamEnd = FnDecl->param_end();
9604        Param != ParamEnd; ++Param) {
9605     if ((*Param)->hasDefaultArg()) {
9606       Diag((*Param)->getDefaultArgRange().getBegin(),
9607            diag::err_literal_operator_default_argument)
9608         << (*Param)->getDefaultArgRange();
9609       break;
9610     }
9611   }
9612 
9613   StringRef LiteralName
9614     = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
9615   if (LiteralName[0] != '_') {
9616     // C++11 [usrlit.suffix]p1:
9617     //   Literal suffix identifiers that do not start with an underscore
9618     //   are reserved for future standardization.
9619     Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved);
9620   }
9621 
9622   return false;
9623 }
9624 
9625 /// ActOnStartLinkageSpecification - Parsed the beginning of a C++
9626 /// linkage specification, including the language and (if present)
9627 /// the '{'. ExternLoc is the location of the 'extern', LangLoc is
9628 /// the location of the language string literal, which is provided
9629 /// by Lang/StrSize. LBraceLoc, if valid, provides the location of
9630 /// the '{' brace. Otherwise, this linkage specification does not
9631 /// have any braces.
ActOnStartLinkageSpecification(Scope * S,SourceLocation ExternLoc,SourceLocation LangLoc,StringRef Lang,SourceLocation LBraceLoc)9632 Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
9633                                            SourceLocation LangLoc,
9634                                            StringRef Lang,
9635                                            SourceLocation LBraceLoc) {
9636   LinkageSpecDecl::LanguageIDs Language;
9637   if (Lang == "\"C\"")
9638     Language = LinkageSpecDecl::lang_c;
9639   else if (Lang == "\"C++\"")
9640     Language = LinkageSpecDecl::lang_cxx;
9641   else {
9642     Diag(LangLoc, diag::err_bad_language);
9643     return 0;
9644   }
9645 
9646   // FIXME: Add all the various semantics of linkage specifications
9647 
9648   LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
9649                                                ExternLoc, LangLoc, Language);
9650   CurContext->addDecl(D);
9651   PushDeclContext(S, D);
9652   return D;
9653 }
9654 
9655 /// ActOnFinishLinkageSpecification - Complete the definition of
9656 /// the C++ linkage specification LinkageSpec. If RBraceLoc is
9657 /// valid, it's the position of the closing '}' brace in a linkage
9658 /// specification that uses braces.
ActOnFinishLinkageSpecification(Scope * S,Decl * LinkageSpec,SourceLocation RBraceLoc)9659 Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
9660                                             Decl *LinkageSpec,
9661                                             SourceLocation RBraceLoc) {
9662   if (LinkageSpec) {
9663     if (RBraceLoc.isValid()) {
9664       LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
9665       LSDecl->setRBraceLoc(RBraceLoc);
9666     }
9667     PopDeclContext();
9668   }
9669   return LinkageSpec;
9670 }
9671 
9672 /// \brief Perform semantic analysis for the variable declaration that
9673 /// occurs within a C++ catch clause, returning the newly-created
9674 /// variable.
BuildExceptionDeclaration(Scope * S,TypeSourceInfo * TInfo,SourceLocation StartLoc,SourceLocation Loc,IdentifierInfo * Name)9675 VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
9676                                          TypeSourceInfo *TInfo,
9677                                          SourceLocation StartLoc,
9678                                          SourceLocation Loc,
9679                                          IdentifierInfo *Name) {
9680   bool Invalid = false;
9681   QualType ExDeclType = TInfo->getType();
9682 
9683   // Arrays and functions decay.
9684   if (ExDeclType->isArrayType())
9685     ExDeclType = Context.getArrayDecayedType(ExDeclType);
9686   else if (ExDeclType->isFunctionType())
9687     ExDeclType = Context.getPointerType(ExDeclType);
9688 
9689   // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
9690   // The exception-declaration shall not denote a pointer or reference to an
9691   // incomplete type, other than [cv] void*.
9692   // N2844 forbids rvalue references.
9693   if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
9694     Diag(Loc, diag::err_catch_rvalue_ref);
9695     Invalid = true;
9696   }
9697 
9698   QualType BaseType = ExDeclType;
9699   int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
9700   unsigned DK = diag::err_catch_incomplete;
9701   if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
9702     BaseType = Ptr->getPointeeType();
9703     Mode = 1;
9704     DK = diag::err_catch_incomplete_ptr;
9705   } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
9706     // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
9707     BaseType = Ref->getPointeeType();
9708     Mode = 2;
9709     DK = diag::err_catch_incomplete_ref;
9710   }
9711   if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
9712       !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
9713     Invalid = true;
9714 
9715   if (!Invalid && !ExDeclType->isDependentType() &&
9716       RequireNonAbstractType(Loc, ExDeclType,
9717                              diag::err_abstract_type_in_decl,
9718                              AbstractVariableType))
9719     Invalid = true;
9720 
9721   // Only the non-fragile NeXT runtime currently supports C++ catches
9722   // of ObjC types, and no runtime supports catching ObjC types by value.
9723   if (!Invalid && getLangOpts().ObjC1) {
9724     QualType T = ExDeclType;
9725     if (const ReferenceType *RT = T->getAs<ReferenceType>())
9726       T = RT->getPointeeType();
9727 
9728     if (T->isObjCObjectType()) {
9729       Diag(Loc, diag::err_objc_object_catch);
9730       Invalid = true;
9731     } else if (T->isObjCObjectPointerType()) {
9732       if (!getLangOpts().ObjCNonFragileABI)
9733         Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
9734     }
9735   }
9736 
9737   VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
9738                                     ExDeclType, TInfo, SC_None, SC_None);
9739   ExDecl->setExceptionVariable(true);
9740 
9741   // In ARC, infer 'retaining' for variables of retainable type.
9742   if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
9743     Invalid = true;
9744 
9745   if (!Invalid && !ExDeclType->isDependentType()) {
9746     if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
9747       // C++ [except.handle]p16:
9748       //   The object declared in an exception-declaration or, if the
9749       //   exception-declaration does not specify a name, a temporary (12.2) is
9750       //   copy-initialized (8.5) from the exception object. [...]
9751       //   The object is destroyed when the handler exits, after the destruction
9752       //   of any automatic objects initialized within the handler.
9753       //
9754       // We just pretend to initialize the object with itself, then make sure
9755       // it can be destroyed later.
9756       QualType initType = ExDeclType;
9757 
9758       InitializedEntity entity =
9759         InitializedEntity::InitializeVariable(ExDecl);
9760       InitializationKind initKind =
9761         InitializationKind::CreateCopy(Loc, SourceLocation());
9762 
9763       Expr *opaqueValue =
9764         new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
9765       InitializationSequence sequence(*this, entity, initKind, &opaqueValue, 1);
9766       ExprResult result = sequence.Perform(*this, entity, initKind,
9767                                            MultiExprArg(&opaqueValue, 1));
9768       if (result.isInvalid())
9769         Invalid = true;
9770       else {
9771         // If the constructor used was non-trivial, set this as the
9772         // "initializer".
9773         CXXConstructExpr *construct = cast<CXXConstructExpr>(result.take());
9774         if (!construct->getConstructor()->isTrivial()) {
9775           Expr *init = MaybeCreateExprWithCleanups(construct);
9776           ExDecl->setInit(init);
9777         }
9778 
9779         // And make sure it's destructable.
9780         FinalizeVarWithDestructor(ExDecl, recordType);
9781       }
9782     }
9783   }
9784 
9785   if (Invalid)
9786     ExDecl->setInvalidDecl();
9787 
9788   return ExDecl;
9789 }
9790 
9791 /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
9792 /// handler.
ActOnExceptionDeclarator(Scope * S,Declarator & D)9793 Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
9794   TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
9795   bool Invalid = D.isInvalidType();
9796 
9797   // Check for unexpanded parameter packs.
9798   if (TInfo && DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
9799                                                UPPC_ExceptionType)) {
9800     TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
9801                                              D.getIdentifierLoc());
9802     Invalid = true;
9803   }
9804 
9805   IdentifierInfo *II = D.getIdentifier();
9806   if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
9807                                              LookupOrdinaryName,
9808                                              ForRedeclaration)) {
9809     // The scope should be freshly made just for us. There is just no way
9810     // it contains any previous declaration.
9811     assert(!S->isDeclScope(PrevDecl));
9812     if (PrevDecl->isTemplateParameter()) {
9813       // Maybe we will complain about the shadowed template parameter.
9814       DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
9815       PrevDecl = 0;
9816     }
9817   }
9818 
9819   if (D.getCXXScopeSpec().isSet() && !Invalid) {
9820     Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
9821       << D.getCXXScopeSpec().getRange();
9822     Invalid = true;
9823   }
9824 
9825   VarDecl *ExDecl = BuildExceptionDeclaration(S, TInfo,
9826                                               D.getLocStart(),
9827                                               D.getIdentifierLoc(),
9828                                               D.getIdentifier());
9829   if (Invalid)
9830     ExDecl->setInvalidDecl();
9831 
9832   // Add the exception declaration into this scope.
9833   if (II)
9834     PushOnScopeChains(ExDecl, S);
9835   else
9836     CurContext->addDecl(ExDecl);
9837 
9838   ProcessDeclAttributes(S, ExDecl, D);
9839   return ExDecl;
9840 }
9841 
ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,Expr * AssertExpr,Expr * AssertMessageExpr_,SourceLocation RParenLoc)9842 Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
9843                                          Expr *AssertExpr,
9844                                          Expr *AssertMessageExpr_,
9845                                          SourceLocation RParenLoc) {
9846   StringLiteral *AssertMessage = cast<StringLiteral>(AssertMessageExpr_);
9847 
9848   if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
9849     // In a static_assert-declaration, the constant-expression shall be a
9850     // constant expression that can be contextually converted to bool.
9851     ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
9852     if (Converted.isInvalid())
9853       return 0;
9854 
9855     llvm::APSInt Cond;
9856     if (VerifyIntegerConstantExpression(Converted.get(), &Cond,
9857           PDiag(diag::err_static_assert_expression_is_not_constant),
9858           /*AllowFold=*/false).isInvalid())
9859       return 0;
9860 
9861     if (!Cond) {
9862       llvm::SmallString<256> MsgBuffer;
9863       llvm::raw_svector_ostream Msg(MsgBuffer);
9864       AssertMessage->printPretty(Msg, Context, 0, getPrintingPolicy());
9865       Diag(StaticAssertLoc, diag::err_static_assert_failed)
9866         << Msg.str() << AssertExpr->getSourceRange();
9867     }
9868   }
9869 
9870   if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
9871     return 0;
9872 
9873   Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
9874                                         AssertExpr, AssertMessage, RParenLoc);
9875 
9876   CurContext->addDecl(Decl);
9877   return Decl;
9878 }
9879 
9880 /// \brief Perform semantic analysis of the given friend type declaration.
9881 ///
9882 /// \returns A friend declaration that.
CheckFriendTypeDecl(SourceLocation Loc,SourceLocation FriendLoc,TypeSourceInfo * TSInfo)9883 FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation Loc,
9884                                       SourceLocation FriendLoc,
9885                                       TypeSourceInfo *TSInfo) {
9886   assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
9887 
9888   QualType T = TSInfo->getType();
9889   SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
9890 
9891   // C++03 [class.friend]p2:
9892   //   An elaborated-type-specifier shall be used in a friend declaration
9893   //   for a class.*
9894   //
9895   //   * The class-key of the elaborated-type-specifier is required.
9896   if (!ActiveTemplateInstantiations.empty()) {
9897     // Do not complain about the form of friend template types during
9898     // template instantiation; we will already have complained when the
9899     // template was declared.
9900   } else if (!T->isElaboratedTypeSpecifier()) {
9901     // If we evaluated the type to a record type, suggest putting
9902     // a tag in front.
9903     if (const RecordType *RT = T->getAs<RecordType>()) {
9904       RecordDecl *RD = RT->getDecl();
9905 
9906       std::string InsertionText = std::string(" ") + RD->getKindName();
9907 
9908       Diag(TypeRange.getBegin(),
9909            getLangOpts().CPlusPlus0x ?
9910              diag::warn_cxx98_compat_unelaborated_friend_type :
9911              diag::ext_unelaborated_friend_type)
9912         << (unsigned) RD->getTagKind()
9913         << T
9914         << FixItHint::CreateInsertion(PP.getLocForEndOfToken(FriendLoc),
9915                                       InsertionText);
9916     } else {
9917       Diag(FriendLoc,
9918            getLangOpts().CPlusPlus0x ?
9919              diag::warn_cxx98_compat_nonclass_type_friend :
9920              diag::ext_nonclass_type_friend)
9921         << T
9922         << SourceRange(FriendLoc, TypeRange.getEnd());
9923     }
9924   } else if (T->getAs<EnumType>()) {
9925     Diag(FriendLoc,
9926          getLangOpts().CPlusPlus0x ?
9927            diag::warn_cxx98_compat_enum_friend :
9928            diag::ext_enum_friend)
9929       << T
9930       << SourceRange(FriendLoc, TypeRange.getEnd());
9931   }
9932 
9933   // C++0x [class.friend]p3:
9934   //   If the type specifier in a friend declaration designates a (possibly
9935   //   cv-qualified) class type, that class is declared as a friend; otherwise,
9936   //   the friend declaration is ignored.
9937 
9938   // FIXME: C++0x has some syntactic restrictions on friend type declarations
9939   // in [class.friend]p3 that we do not implement.
9940 
9941   return FriendDecl::Create(Context, CurContext, Loc, TSInfo, FriendLoc);
9942 }
9943 
9944 /// Handle a friend tag declaration where the scope specifier was
9945 /// templated.
ActOnTemplatedFriendTag(Scope * S,SourceLocation FriendLoc,unsigned TagSpec,SourceLocation TagLoc,CXXScopeSpec & SS,IdentifierInfo * Name,SourceLocation NameLoc,AttributeList * Attr,MultiTemplateParamsArg TempParamLists)9946 Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
9947                                     unsigned TagSpec, SourceLocation TagLoc,
9948                                     CXXScopeSpec &SS,
9949                                     IdentifierInfo *Name, SourceLocation NameLoc,
9950                                     AttributeList *Attr,
9951                                     MultiTemplateParamsArg TempParamLists) {
9952   TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
9953 
9954   bool isExplicitSpecialization = false;
9955   bool Invalid = false;
9956 
9957   if (TemplateParameterList *TemplateParams
9958         = MatchTemplateParametersToScopeSpecifier(TagLoc, NameLoc, SS,
9959                                                   TempParamLists.get(),
9960                                                   TempParamLists.size(),
9961                                                   /*friend*/ true,
9962                                                   isExplicitSpecialization,
9963                                                   Invalid)) {
9964     if (TemplateParams->size() > 0) {
9965       // This is a declaration of a class template.
9966       if (Invalid)
9967         return 0;
9968 
9969       return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc,
9970                                 SS, Name, NameLoc, Attr,
9971                                 TemplateParams, AS_public,
9972                                 /*ModulePrivateLoc=*/SourceLocation(),
9973                                 TempParamLists.size() - 1,
9974                    (TemplateParameterList**) TempParamLists.release()).take();
9975     } else {
9976       // The "template<>" header is extraneous.
9977       Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
9978         << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
9979       isExplicitSpecialization = true;
9980     }
9981   }
9982 
9983   if (Invalid) return 0;
9984 
9985   bool isAllExplicitSpecializations = true;
9986   for (unsigned I = TempParamLists.size(); I-- > 0; ) {
9987     if (TempParamLists.get()[I]->size()) {
9988       isAllExplicitSpecializations = false;
9989       break;
9990     }
9991   }
9992 
9993   // FIXME: don't ignore attributes.
9994 
9995   // If it's explicit specializations all the way down, just forget
9996   // about the template header and build an appropriate non-templated
9997   // friend.  TODO: for source fidelity, remember the headers.
9998   if (isAllExplicitSpecializations) {
9999     if (SS.isEmpty()) {
10000       bool Owned = false;
10001       bool IsDependent = false;
10002       return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
10003                       Attr, AS_public,
10004                       /*ModulePrivateLoc=*/SourceLocation(),
10005                       MultiTemplateParamsArg(), Owned, IsDependent,
10006                       /*ScopedEnumKWLoc=*/SourceLocation(),
10007                       /*ScopedEnumUsesClassTag=*/false,
10008                       /*UnderlyingType=*/TypeResult());
10009     }
10010 
10011     NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
10012     ElaboratedTypeKeyword Keyword
10013       = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
10014     QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
10015                                    *Name, NameLoc);
10016     if (T.isNull())
10017       return 0;
10018 
10019     TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
10020     if (isa<DependentNameType>(T)) {
10021       DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
10022       TL.setElaboratedKeywordLoc(TagLoc);
10023       TL.setQualifierLoc(QualifierLoc);
10024       TL.setNameLoc(NameLoc);
10025     } else {
10026       ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc());
10027       TL.setElaboratedKeywordLoc(TagLoc);
10028       TL.setQualifierLoc(QualifierLoc);
10029       cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(NameLoc);
10030     }
10031 
10032     FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
10033                                             TSI, FriendLoc);
10034     Friend->setAccess(AS_public);
10035     CurContext->addDecl(Friend);
10036     return Friend;
10037   }
10038 
10039   assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
10040 
10041 
10042 
10043   // Handle the case of a templated-scope friend class.  e.g.
10044   //   template <class T> class A<T>::B;
10045   // FIXME: we don't support these right now.
10046   ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
10047   QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
10048   TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
10049   DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
10050   TL.setElaboratedKeywordLoc(TagLoc);
10051   TL.setQualifierLoc(SS.getWithLocInContext(Context));
10052   TL.setNameLoc(NameLoc);
10053 
10054   FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
10055                                           TSI, FriendLoc);
10056   Friend->setAccess(AS_public);
10057   Friend->setUnsupportedFriend(true);
10058   CurContext->addDecl(Friend);
10059   return Friend;
10060 }
10061 
10062 
10063 /// Handle a friend type declaration.  This works in tandem with
10064 /// ActOnTag.
10065 ///
10066 /// Notes on friend class templates:
10067 ///
10068 /// We generally treat friend class declarations as if they were
10069 /// declaring a class.  So, for example, the elaborated type specifier
10070 /// in a friend declaration is required to obey the restrictions of a
10071 /// class-head (i.e. no typedefs in the scope chain), template
10072 /// parameters are required to match up with simple template-ids, &c.
10073 /// However, unlike when declaring a template specialization, it's
10074 /// okay to refer to a template specialization without an empty
10075 /// template parameter declaration, e.g.
10076 ///   friend class A<T>::B<unsigned>;
10077 /// We permit this as a special case; if there are any template
10078 /// parameters present at all, require proper matching, i.e.
10079 ///   template <> template <class T> friend class A<int>::B;
ActOnFriendTypeDecl(Scope * S,const DeclSpec & DS,MultiTemplateParamsArg TempParams)10080 Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
10081                                 MultiTemplateParamsArg TempParams) {
10082   SourceLocation Loc = DS.getLocStart();
10083 
10084   assert(DS.isFriendSpecified());
10085   assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
10086 
10087   // Try to convert the decl specifier to a type.  This works for
10088   // friend templates because ActOnTag never produces a ClassTemplateDecl
10089   // for a TUK_Friend.
10090   Declarator TheDeclarator(DS, Declarator::MemberContext);
10091   TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
10092   QualType T = TSI->getType();
10093   if (TheDeclarator.isInvalidType())
10094     return 0;
10095 
10096   if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
10097     return 0;
10098 
10099   // This is definitely an error in C++98.  It's probably meant to
10100   // be forbidden in C++0x, too, but the specification is just
10101   // poorly written.
10102   //
10103   // The problem is with declarations like the following:
10104   //   template <T> friend A<T>::foo;
10105   // where deciding whether a class C is a friend or not now hinges
10106   // on whether there exists an instantiation of A that causes
10107   // 'foo' to equal C.  There are restrictions on class-heads
10108   // (which we declare (by fiat) elaborated friend declarations to
10109   // be) that makes this tractable.
10110   //
10111   // FIXME: handle "template <> friend class A<T>;", which
10112   // is possibly well-formed?  Who even knows?
10113   if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
10114     Diag(Loc, diag::err_tagless_friend_type_template)
10115       << DS.getSourceRange();
10116     return 0;
10117   }
10118 
10119   // C++98 [class.friend]p1: A friend of a class is a function
10120   //   or class that is not a member of the class . . .
10121   // This is fixed in DR77, which just barely didn't make the C++03
10122   // deadline.  It's also a very silly restriction that seriously
10123   // affects inner classes and which nobody else seems to implement;
10124   // thus we never diagnose it, not even in -pedantic.
10125   //
10126   // But note that we could warn about it: it's always useless to
10127   // friend one of your own members (it's not, however, worthless to
10128   // friend a member of an arbitrary specialization of your template).
10129 
10130   Decl *D;
10131   if (unsigned NumTempParamLists = TempParams.size())
10132     D = FriendTemplateDecl::Create(Context, CurContext, Loc,
10133                                    NumTempParamLists,
10134                                    TempParams.release(),
10135                                    TSI,
10136                                    DS.getFriendSpecLoc());
10137   else
10138     D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
10139 
10140   if (!D)
10141     return 0;
10142 
10143   D->setAccess(AS_public);
10144   CurContext->addDecl(D);
10145 
10146   return D;
10147 }
10148 
ActOnFriendFunctionDecl(Scope * S,Declarator & D,MultiTemplateParamsArg TemplateParams)10149 Decl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
10150                                     MultiTemplateParamsArg TemplateParams) {
10151   const DeclSpec &DS = D.getDeclSpec();
10152 
10153   assert(DS.isFriendSpecified());
10154   assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
10155 
10156   SourceLocation Loc = D.getIdentifierLoc();
10157   TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
10158 
10159   // C++ [class.friend]p1
10160   //   A friend of a class is a function or class....
10161   // Note that this sees through typedefs, which is intended.
10162   // It *doesn't* see through dependent types, which is correct
10163   // according to [temp.arg.type]p3:
10164   //   If a declaration acquires a function type through a
10165   //   type dependent on a template-parameter and this causes
10166   //   a declaration that does not use the syntactic form of a
10167   //   function declarator to have a function type, the program
10168   //   is ill-formed.
10169   if (!TInfo->getType()->isFunctionType()) {
10170     Diag(Loc, diag::err_unexpected_friend);
10171 
10172     // It might be worthwhile to try to recover by creating an
10173     // appropriate declaration.
10174     return 0;
10175   }
10176 
10177   // C++ [namespace.memdef]p3
10178   //  - If a friend declaration in a non-local class first declares a
10179   //    class or function, the friend class or function is a member
10180   //    of the innermost enclosing namespace.
10181   //  - The name of the friend is not found by simple name lookup
10182   //    until a matching declaration is provided in that namespace
10183   //    scope (either before or after the class declaration granting
10184   //    friendship).
10185   //  - If a friend function is called, its name may be found by the
10186   //    name lookup that considers functions from namespaces and
10187   //    classes associated with the types of the function arguments.
10188   //  - When looking for a prior declaration of a class or a function
10189   //    declared as a friend, scopes outside the innermost enclosing
10190   //    namespace scope are not considered.
10191 
10192   CXXScopeSpec &SS = D.getCXXScopeSpec();
10193   DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
10194   DeclarationName Name = NameInfo.getName();
10195   assert(Name);
10196 
10197   // Check for unexpanded parameter packs.
10198   if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
10199       DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
10200       DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
10201     return 0;
10202 
10203   // The context we found the declaration in, or in which we should
10204   // create the declaration.
10205   DeclContext *DC;
10206   Scope *DCScope = S;
10207   LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
10208                         ForRedeclaration);
10209 
10210   // FIXME: there are different rules in local classes
10211 
10212   // There are four cases here.
10213   //   - There's no scope specifier, in which case we just go to the
10214   //     appropriate scope and look for a function or function template
10215   //     there as appropriate.
10216   // Recover from invalid scope qualifiers as if they just weren't there.
10217   if (SS.isInvalid() || !SS.isSet()) {
10218     // C++0x [namespace.memdef]p3:
10219     //   If the name in a friend declaration is neither qualified nor
10220     //   a template-id and the declaration is a function or an
10221     //   elaborated-type-specifier, the lookup to determine whether
10222     //   the entity has been previously declared shall not consider
10223     //   any scopes outside the innermost enclosing namespace.
10224     // C++0x [class.friend]p11:
10225     //   If a friend declaration appears in a local class and the name
10226     //   specified is an unqualified name, a prior declaration is
10227     //   looked up without considering scopes that are outside the
10228     //   innermost enclosing non-class scope. For a friend function
10229     //   declaration, if there is no prior declaration, the program is
10230     //   ill-formed.
10231     bool isLocal = cast<CXXRecordDecl>(CurContext)->isLocalClass();
10232     bool isTemplateId = D.getName().getKind() == UnqualifiedId::IK_TemplateId;
10233 
10234     // Find the appropriate context according to the above.
10235     DC = CurContext;
10236     while (true) {
10237       // Skip class contexts.  If someone can cite chapter and verse
10238       // for this behavior, that would be nice --- it's what GCC and
10239       // EDG do, and it seems like a reasonable intent, but the spec
10240       // really only says that checks for unqualified existing
10241       // declarations should stop at the nearest enclosing namespace,
10242       // not that they should only consider the nearest enclosing
10243       // namespace.
10244       while (DC->isRecord() || DC->isTransparentContext())
10245         DC = DC->getParent();
10246 
10247       LookupQualifiedName(Previous, DC);
10248 
10249       // TODO: decide what we think about using declarations.
10250       if (isLocal || !Previous.empty())
10251         break;
10252 
10253       if (isTemplateId) {
10254         if (isa<TranslationUnitDecl>(DC)) break;
10255       } else {
10256         if (DC->isFileContext()) break;
10257       }
10258       DC = DC->getParent();
10259     }
10260 
10261     // C++ [class.friend]p1: A friend of a class is a function or
10262     //   class that is not a member of the class . . .
10263     // C++11 changes this for both friend types and functions.
10264     // Most C++ 98 compilers do seem to give an error here, so
10265     // we do, too.
10266     if (!Previous.empty() && DC->Equals(CurContext))
10267       Diag(DS.getFriendSpecLoc(),
10268            getLangOpts().CPlusPlus0x ?
10269              diag::warn_cxx98_compat_friend_is_member :
10270              diag::err_friend_is_member);
10271 
10272     DCScope = getScopeForDeclContext(S, DC);
10273 
10274     // C++ [class.friend]p6:
10275     //   A function can be defined in a friend declaration of a class if and
10276     //   only if the class is a non-local class (9.8), the function name is
10277     //   unqualified, and the function has namespace scope.
10278     if (isLocal && D.isFunctionDefinition()) {
10279       Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
10280     }
10281 
10282   //   - There's a non-dependent scope specifier, in which case we
10283   //     compute it and do a previous lookup there for a function
10284   //     or function template.
10285   } else if (!SS.getScopeRep()->isDependent()) {
10286     DC = computeDeclContext(SS);
10287     if (!DC) return 0;
10288 
10289     if (RequireCompleteDeclContext(SS, DC)) return 0;
10290 
10291     LookupQualifiedName(Previous, DC);
10292 
10293     // Ignore things found implicitly in the wrong scope.
10294     // TODO: better diagnostics for this case.  Suggesting the right
10295     // qualified scope would be nice...
10296     LookupResult::Filter F = Previous.makeFilter();
10297     while (F.hasNext()) {
10298       NamedDecl *D = F.next();
10299       if (!DC->InEnclosingNamespaceSetOf(
10300               D->getDeclContext()->getRedeclContext()))
10301         F.erase();
10302     }
10303     F.done();
10304 
10305     if (Previous.empty()) {
10306       D.setInvalidType();
10307       Diag(Loc, diag::err_qualified_friend_not_found)
10308           << Name << TInfo->getType();
10309       return 0;
10310     }
10311 
10312     // C++ [class.friend]p1: A friend of a class is a function or
10313     //   class that is not a member of the class . . .
10314     if (DC->Equals(CurContext))
10315       Diag(DS.getFriendSpecLoc(),
10316            getLangOpts().CPlusPlus0x ?
10317              diag::warn_cxx98_compat_friend_is_member :
10318              diag::err_friend_is_member);
10319 
10320     if (D.isFunctionDefinition()) {
10321       // C++ [class.friend]p6:
10322       //   A function can be defined in a friend declaration of a class if and
10323       //   only if the class is a non-local class (9.8), the function name is
10324       //   unqualified, and the function has namespace scope.
10325       SemaDiagnosticBuilder DB
10326         = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
10327 
10328       DB << SS.getScopeRep();
10329       if (DC->isFileContext())
10330         DB << FixItHint::CreateRemoval(SS.getRange());
10331       SS.clear();
10332     }
10333 
10334   //   - There's a scope specifier that does not match any template
10335   //     parameter lists, in which case we use some arbitrary context,
10336   //     create a method or method template, and wait for instantiation.
10337   //   - There's a scope specifier that does match some template
10338   //     parameter lists, which we don't handle right now.
10339   } else {
10340     if (D.isFunctionDefinition()) {
10341       // C++ [class.friend]p6:
10342       //   A function can be defined in a friend declaration of a class if and
10343       //   only if the class is a non-local class (9.8), the function name is
10344       //   unqualified, and the function has namespace scope.
10345       Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
10346         << SS.getScopeRep();
10347     }
10348 
10349     DC = CurContext;
10350     assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
10351   }
10352 
10353   if (!DC->isRecord()) {
10354     // This implies that it has to be an operator or function.
10355     if (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ||
10356         D.getName().getKind() == UnqualifiedId::IK_DestructorName ||
10357         D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId) {
10358       Diag(Loc, diag::err_introducing_special_friend) <<
10359         (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ? 0 :
10360          D.getName().getKind() == UnqualifiedId::IK_DestructorName ? 1 : 2);
10361       return 0;
10362     }
10363   }
10364 
10365   // FIXME: This is an egregious hack to cope with cases where the scope stack
10366   // does not contain the declaration context, i.e., in an out-of-line
10367   // definition of a class.
10368   Scope FakeDCScope(S, Scope::DeclScope, Diags);
10369   if (!DCScope) {
10370     FakeDCScope.setEntity(DC);
10371     DCScope = &FakeDCScope;
10372   }
10373 
10374   bool AddToScope = true;
10375   NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
10376                                           move(TemplateParams), AddToScope);
10377   if (!ND) return 0;
10378 
10379   assert(ND->getDeclContext() == DC);
10380   assert(ND->getLexicalDeclContext() == CurContext);
10381 
10382   // Add the function declaration to the appropriate lookup tables,
10383   // adjusting the redeclarations list as necessary.  We don't
10384   // want to do this yet if the friending class is dependent.
10385   //
10386   // Also update the scope-based lookup if the target context's
10387   // lookup context is in lexical scope.
10388   if (!CurContext->isDependentContext()) {
10389     DC = DC->getRedeclContext();
10390     DC->makeDeclVisibleInContext(ND);
10391     if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
10392       PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
10393   }
10394 
10395   FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
10396                                        D.getIdentifierLoc(), ND,
10397                                        DS.getFriendSpecLoc());
10398   FrD->setAccess(AS_public);
10399   CurContext->addDecl(FrD);
10400 
10401   if (ND->isInvalidDecl())
10402     FrD->setInvalidDecl();
10403   else {
10404     FunctionDecl *FD;
10405     if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
10406       FD = FTD->getTemplatedDecl();
10407     else
10408       FD = cast<FunctionDecl>(ND);
10409 
10410     // Mark templated-scope function declarations as unsupported.
10411     if (FD->getNumTemplateParameterLists())
10412       FrD->setUnsupportedFriend(true);
10413   }
10414 
10415   return ND;
10416 }
10417 
SetDeclDeleted(Decl * Dcl,SourceLocation DelLoc)10418 void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
10419   AdjustDeclIfTemplate(Dcl);
10420 
10421   FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
10422   if (!Fn) {
10423     Diag(DelLoc, diag::err_deleted_non_function);
10424     return;
10425   }
10426   if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
10427     Diag(DelLoc, diag::err_deleted_decl_not_first);
10428     Diag(Prev->getLocation(), diag::note_previous_declaration);
10429     // If the declaration wasn't the first, we delete the function anyway for
10430     // recovery.
10431   }
10432   Fn->setDeletedAsWritten();
10433 
10434   CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10435   if (!MD)
10436     return;
10437 
10438   // A deleted special member function is trivial if the corresponding
10439   // implicitly-declared function would have been.
10440   switch (getSpecialMember(MD)) {
10441   case CXXInvalid:
10442     break;
10443   case CXXDefaultConstructor:
10444     MD->setTrivial(MD->getParent()->hasTrivialDefaultConstructor());
10445     break;
10446   case CXXCopyConstructor:
10447     MD->setTrivial(MD->getParent()->hasTrivialCopyConstructor());
10448     break;
10449   case CXXMoveConstructor:
10450     MD->setTrivial(MD->getParent()->hasTrivialMoveConstructor());
10451     break;
10452   case CXXCopyAssignment:
10453     MD->setTrivial(MD->getParent()->hasTrivialCopyAssignment());
10454     break;
10455   case CXXMoveAssignment:
10456     MD->setTrivial(MD->getParent()->hasTrivialMoveAssignment());
10457     break;
10458   case CXXDestructor:
10459     MD->setTrivial(MD->getParent()->hasTrivialDestructor());
10460     break;
10461   }
10462 }
10463 
SetDeclDefaulted(Decl * Dcl,SourceLocation DefaultLoc)10464 void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
10465   CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Dcl);
10466 
10467   if (MD) {
10468     if (MD->getParent()->isDependentType()) {
10469       MD->setDefaulted();
10470       MD->setExplicitlyDefaulted();
10471       return;
10472     }
10473 
10474     CXXSpecialMember Member = getSpecialMember(MD);
10475     if (Member == CXXInvalid) {
10476       Diag(DefaultLoc, diag::err_default_special_members);
10477       return;
10478     }
10479 
10480     MD->setDefaulted();
10481     MD->setExplicitlyDefaulted();
10482 
10483     // If this definition appears within the record, do the checking when
10484     // the record is complete.
10485     const FunctionDecl *Primary = MD;
10486     if (MD->getTemplatedKind() != FunctionDecl::TK_NonTemplate)
10487       // Find the uninstantiated declaration that actually had the '= default'
10488       // on it.
10489       MD->getTemplateInstantiationPattern()->isDefined(Primary);
10490 
10491     if (Primary == Primary->getCanonicalDecl())
10492       return;
10493 
10494     switch (Member) {
10495     case CXXDefaultConstructor: {
10496       CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10497       CheckExplicitlyDefaultedDefaultConstructor(CD);
10498       if (!CD->isInvalidDecl())
10499         DefineImplicitDefaultConstructor(DefaultLoc, CD);
10500       break;
10501     }
10502 
10503     case CXXCopyConstructor: {
10504       CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10505       CheckExplicitlyDefaultedCopyConstructor(CD);
10506       if (!CD->isInvalidDecl())
10507         DefineImplicitCopyConstructor(DefaultLoc, CD);
10508       break;
10509     }
10510 
10511     case CXXCopyAssignment: {
10512       CheckExplicitlyDefaultedCopyAssignment(MD);
10513       if (!MD->isInvalidDecl())
10514         DefineImplicitCopyAssignment(DefaultLoc, MD);
10515       break;
10516     }
10517 
10518     case CXXDestructor: {
10519       CXXDestructorDecl *DD = cast<CXXDestructorDecl>(MD);
10520       CheckExplicitlyDefaultedDestructor(DD);
10521       if (!DD->isInvalidDecl())
10522         DefineImplicitDestructor(DefaultLoc, DD);
10523       break;
10524     }
10525 
10526     case CXXMoveConstructor: {
10527       CXXConstructorDecl *CD = cast<CXXConstructorDecl>(MD);
10528       CheckExplicitlyDefaultedMoveConstructor(CD);
10529       if (!CD->isInvalidDecl())
10530         DefineImplicitMoveConstructor(DefaultLoc, CD);
10531       break;
10532     }
10533 
10534     case CXXMoveAssignment: {
10535       CheckExplicitlyDefaultedMoveAssignment(MD);
10536       if (!MD->isInvalidDecl())
10537         DefineImplicitMoveAssignment(DefaultLoc, MD);
10538       break;
10539     }
10540 
10541     case CXXInvalid:
10542       llvm_unreachable("Invalid special member.");
10543     }
10544   } else {
10545     Diag(DefaultLoc, diag::err_default_special_members);
10546   }
10547 }
10548 
SearchForReturnInStmt(Sema & Self,Stmt * S)10549 static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
10550   for (Stmt::child_range CI = S->children(); CI; ++CI) {
10551     Stmt *SubStmt = *CI;
10552     if (!SubStmt)
10553       continue;
10554     if (isa<ReturnStmt>(SubStmt))
10555       Self.Diag(SubStmt->getLocStart(),
10556            diag::err_return_in_constructor_handler);
10557     if (!isa<Expr>(SubStmt))
10558       SearchForReturnInStmt(Self, SubStmt);
10559   }
10560 }
10561 
DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt * TryBlock)10562 void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
10563   for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
10564     CXXCatchStmt *Handler = TryBlock->getHandler(I);
10565     SearchForReturnInStmt(*this, Handler);
10566   }
10567 }
10568 
CheckOverridingFunctionReturnType(const CXXMethodDecl * New,const CXXMethodDecl * Old)10569 bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
10570                                              const CXXMethodDecl *Old) {
10571   QualType NewTy = New->getType()->getAs<FunctionType>()->getResultType();
10572   QualType OldTy = Old->getType()->getAs<FunctionType>()->getResultType();
10573 
10574   if (Context.hasSameType(NewTy, OldTy) ||
10575       NewTy->isDependentType() || OldTy->isDependentType())
10576     return false;
10577 
10578   // Check if the return types are covariant
10579   QualType NewClassTy, OldClassTy;
10580 
10581   /// Both types must be pointers or references to classes.
10582   if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
10583     if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
10584       NewClassTy = NewPT->getPointeeType();
10585       OldClassTy = OldPT->getPointeeType();
10586     }
10587   } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
10588     if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
10589       if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
10590         NewClassTy = NewRT->getPointeeType();
10591         OldClassTy = OldRT->getPointeeType();
10592       }
10593     }
10594   }
10595 
10596   // The return types aren't either both pointers or references to a class type.
10597   if (NewClassTy.isNull()) {
10598     Diag(New->getLocation(),
10599          diag::err_different_return_type_for_overriding_virtual_function)
10600       << New->getDeclName() << NewTy << OldTy;
10601     Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10602 
10603     return true;
10604   }
10605 
10606   // C++ [class.virtual]p6:
10607   //   If the return type of D::f differs from the return type of B::f, the
10608   //   class type in the return type of D::f shall be complete at the point of
10609   //   declaration of D::f or shall be the class type D.
10610   if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
10611     if (!RT->isBeingDefined() &&
10612         RequireCompleteType(New->getLocation(), NewClassTy,
10613                             PDiag(diag::err_covariant_return_incomplete)
10614                               << New->getDeclName()))
10615     return true;
10616   }
10617 
10618   if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
10619     // Check if the new class derives from the old class.
10620     if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
10621       Diag(New->getLocation(),
10622            diag::err_covariant_return_not_derived)
10623       << New->getDeclName() << NewTy << OldTy;
10624       Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10625       return true;
10626     }
10627 
10628     // Check if we the conversion from derived to base is valid.
10629     if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy,
10630                     diag::err_covariant_return_inaccessible_base,
10631                     diag::err_covariant_return_ambiguous_derived_to_base_conv,
10632                     // FIXME: Should this point to the return type?
10633                     New->getLocation(), SourceRange(), New->getDeclName(), 0)) {
10634       // FIXME: this note won't trigger for delayed access control
10635       // diagnostics, and it's impossible to get an undelayed error
10636       // here from access control during the original parse because
10637       // the ParsingDeclSpec/ParsingDeclarator are still in scope.
10638       Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10639       return true;
10640     }
10641   }
10642 
10643   // The qualifiers of the return types must be the same.
10644   if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
10645     Diag(New->getLocation(),
10646          diag::err_covariant_return_type_different_qualifications)
10647     << New->getDeclName() << NewTy << OldTy;
10648     Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10649     return true;
10650   };
10651 
10652 
10653   // The new class type must have the same or less qualifiers as the old type.
10654   if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
10655     Diag(New->getLocation(),
10656          diag::err_covariant_return_type_class_type_more_qualified)
10657     << New->getDeclName() << NewTy << OldTy;
10658     Diag(Old->getLocation(), diag::note_overridden_virtual_function);
10659     return true;
10660   };
10661 
10662   return false;
10663 }
10664 
10665 /// \brief Mark the given method pure.
10666 ///
10667 /// \param Method the method to be marked pure.
10668 ///
10669 /// \param InitRange the source range that covers the "0" initializer.
CheckPureMethod(CXXMethodDecl * Method,SourceRange InitRange)10670 bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
10671   SourceLocation EndLoc = InitRange.getEnd();
10672   if (EndLoc.isValid())
10673     Method->setRangeEnd(EndLoc);
10674 
10675   if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
10676     Method->setPure();
10677     return false;
10678   }
10679 
10680   if (!Method->isInvalidDecl())
10681     Diag(Method->getLocation(), diag::err_non_virtual_pure)
10682       << Method->getDeclName() << InitRange;
10683   return true;
10684 }
10685 
10686 /// \brief Determine whether the given declaration is a static data member.
isStaticDataMember(Decl * D)10687 static bool isStaticDataMember(Decl *D) {
10688   VarDecl *Var = dyn_cast_or_null<VarDecl>(D);
10689   if (!Var)
10690     return false;
10691 
10692   return Var->isStaticDataMember();
10693 }
10694 /// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse
10695 /// an initializer for the out-of-line declaration 'Dcl'.  The scope
10696 /// is a fresh scope pushed for just this purpose.
10697 ///
10698 /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
10699 /// static data member of class X, names should be looked up in the scope of
10700 /// class X.
ActOnCXXEnterDeclInitializer(Scope * S,Decl * D)10701 void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
10702   // If there is no declaration, there was an error parsing it.
10703   if (D == 0 || D->isInvalidDecl()) return;
10704 
10705   // We should only get called for declarations with scope specifiers, like:
10706   //   int foo::bar;
10707   assert(D->isOutOfLine());
10708   EnterDeclaratorContext(S, D->getDeclContext());
10709 
10710   // If we are parsing the initializer for a static data member, push a
10711   // new expression evaluation context that is associated with this static
10712   // data member.
10713   if (isStaticDataMember(D))
10714     PushExpressionEvaluationContext(PotentiallyEvaluated, D);
10715 }
10716 
10717 /// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
10718 /// initializer for the out-of-line declaration 'D'.
ActOnCXXExitDeclInitializer(Scope * S,Decl * D)10719 void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
10720   // If there is no declaration, there was an error parsing it.
10721   if (D == 0 || D->isInvalidDecl()) return;
10722 
10723   if (isStaticDataMember(D))
10724     PopExpressionEvaluationContext();
10725 
10726   assert(D->isOutOfLine());
10727   ExitDeclaratorContext(S);
10728 }
10729 
10730 /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
10731 /// C++ if/switch/while/for statement.
10732 /// e.g: "if (int x = f()) {...}"
ActOnCXXConditionDeclaration(Scope * S,Declarator & D)10733 DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
10734   // C++ 6.4p2:
10735   // The declarator shall not specify a function or an array.
10736   // The type-specifier-seq shall not contain typedef and shall not declare a
10737   // new class or enumeration.
10738   assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
10739          "Parser allowed 'typedef' as storage class of condition decl.");
10740 
10741   Decl *Dcl = ActOnDeclarator(S, D);
10742   if (!Dcl)
10743     return true;
10744 
10745   if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
10746     Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
10747       << D.getSourceRange();
10748     return true;
10749   }
10750 
10751   return Dcl;
10752 }
10753 
LoadExternalVTableUses()10754 void Sema::LoadExternalVTableUses() {
10755   if (!ExternalSource)
10756     return;
10757 
10758   SmallVector<ExternalVTableUse, 4> VTables;
10759   ExternalSource->ReadUsedVTables(VTables);
10760   SmallVector<VTableUse, 4> NewUses;
10761   for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
10762     llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
10763       = VTablesUsed.find(VTables[I].Record);
10764     // Even if a definition wasn't required before, it may be required now.
10765     if (Pos != VTablesUsed.end()) {
10766       if (!Pos->second && VTables[I].DefinitionRequired)
10767         Pos->second = true;
10768       continue;
10769     }
10770 
10771     VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
10772     NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
10773   }
10774 
10775   VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
10776 }
10777 
MarkVTableUsed(SourceLocation Loc,CXXRecordDecl * Class,bool DefinitionRequired)10778 void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
10779                           bool DefinitionRequired) {
10780   // Ignore any vtable uses in unevaluated operands or for classes that do
10781   // not have a vtable.
10782   if (!Class->isDynamicClass() || Class->isDependentContext() ||
10783       CurContext->isDependentContext() ||
10784       ExprEvalContexts.back().Context == Unevaluated)
10785     return;
10786 
10787   // Try to insert this class into the map.
10788   LoadExternalVTableUses();
10789   Class = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10790   std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
10791     Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
10792   if (!Pos.second) {
10793     // If we already had an entry, check to see if we are promoting this vtable
10794     // to required a definition. If so, we need to reappend to the VTableUses
10795     // list, since we may have already processed the first entry.
10796     if (DefinitionRequired && !Pos.first->second) {
10797       Pos.first->second = true;
10798     } else {
10799       // Otherwise, we can early exit.
10800       return;
10801     }
10802   }
10803 
10804   // Local classes need to have their virtual members marked
10805   // immediately. For all other classes, we mark their virtual members
10806   // at the end of the translation unit.
10807   if (Class->isLocalClass())
10808     MarkVirtualMembersReferenced(Loc, Class);
10809   else
10810     VTableUses.push_back(std::make_pair(Class, Loc));
10811 }
10812 
DefineUsedVTables()10813 bool Sema::DefineUsedVTables() {
10814   LoadExternalVTableUses();
10815   if (VTableUses.empty())
10816     return false;
10817 
10818   // Note: The VTableUses vector could grow as a result of marking
10819   // the members of a class as "used", so we check the size each
10820   // time through the loop and prefer indices (with are stable) to
10821   // iterators (which are not).
10822   bool DefinedAnything = false;
10823   for (unsigned I = 0; I != VTableUses.size(); ++I) {
10824     CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
10825     if (!Class)
10826       continue;
10827 
10828     SourceLocation Loc = VTableUses[I].second;
10829 
10830     // If this class has a key function, but that key function is
10831     // defined in another translation unit, we don't need to emit the
10832     // vtable even though we're using it.
10833     const CXXMethodDecl *KeyFunction = Context.getKeyFunction(Class);
10834     if (KeyFunction && !KeyFunction->hasBody()) {
10835       switch (KeyFunction->getTemplateSpecializationKind()) {
10836       case TSK_Undeclared:
10837       case TSK_ExplicitSpecialization:
10838       case TSK_ExplicitInstantiationDeclaration:
10839         // The key function is in another translation unit.
10840         continue;
10841 
10842       case TSK_ExplicitInstantiationDefinition:
10843       case TSK_ImplicitInstantiation:
10844         // We will be instantiating the key function.
10845         break;
10846       }
10847     } else if (!KeyFunction) {
10848       // If we have a class with no key function that is the subject
10849       // of an explicit instantiation declaration, suppress the
10850       // vtable; it will live with the explicit instantiation
10851       // definition.
10852       bool IsExplicitInstantiationDeclaration
10853         = Class->getTemplateSpecializationKind()
10854                                       == TSK_ExplicitInstantiationDeclaration;
10855       for (TagDecl::redecl_iterator R = Class->redecls_begin(),
10856                                  REnd = Class->redecls_end();
10857            R != REnd; ++R) {
10858         TemplateSpecializationKind TSK
10859           = cast<CXXRecordDecl>(*R)->getTemplateSpecializationKind();
10860         if (TSK == TSK_ExplicitInstantiationDeclaration)
10861           IsExplicitInstantiationDeclaration = true;
10862         else if (TSK == TSK_ExplicitInstantiationDefinition) {
10863           IsExplicitInstantiationDeclaration = false;
10864           break;
10865         }
10866       }
10867 
10868       if (IsExplicitInstantiationDeclaration)
10869         continue;
10870     }
10871 
10872     // Mark all of the virtual members of this class as referenced, so
10873     // that we can build a vtable. Then, tell the AST consumer that a
10874     // vtable for this class is required.
10875     DefinedAnything = true;
10876     MarkVirtualMembersReferenced(Loc, Class);
10877     CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
10878     Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
10879 
10880     // Optionally warn if we're emitting a weak vtable.
10881     if (Class->getLinkage() == ExternalLinkage &&
10882         Class->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) {
10883       const FunctionDecl *KeyFunctionDef = 0;
10884       if (!KeyFunction ||
10885           (KeyFunction->hasBody(KeyFunctionDef) &&
10886            KeyFunctionDef->isInlined()))
10887         Diag(Class->getLocation(), Class->getTemplateSpecializationKind() ==
10888              TSK_ExplicitInstantiationDefinition
10889              ? diag::warn_weak_template_vtable : diag::warn_weak_vtable)
10890           << Class;
10891     }
10892   }
10893   VTableUses.clear();
10894 
10895   return DefinedAnything;
10896 }
10897 
MarkVirtualMembersReferenced(SourceLocation Loc,const CXXRecordDecl * RD)10898 void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
10899                                         const CXXRecordDecl *RD) {
10900   for (CXXRecordDecl::method_iterator i = RD->method_begin(),
10901        e = RD->method_end(); i != e; ++i) {
10902     CXXMethodDecl *MD = *i;
10903 
10904     // C++ [basic.def.odr]p2:
10905     //   [...] A virtual member function is used if it is not pure. [...]
10906     if (MD->isVirtual() && !MD->isPure())
10907       MarkFunctionReferenced(Loc, MD);
10908   }
10909 
10910   // Only classes that have virtual bases need a VTT.
10911   if (RD->getNumVBases() == 0)
10912     return;
10913 
10914   for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
10915            e = RD->bases_end(); i != e; ++i) {
10916     const CXXRecordDecl *Base =
10917         cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
10918     if (Base->getNumVBases() == 0)
10919       continue;
10920     MarkVirtualMembersReferenced(Loc, Base);
10921   }
10922 }
10923 
10924 /// SetIvarInitializers - This routine builds initialization ASTs for the
10925 /// Objective-C implementation whose ivars need be initialized.
SetIvarInitializers(ObjCImplementationDecl * ObjCImplementation)10926 void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
10927   if (!getLangOpts().CPlusPlus)
10928     return;
10929   if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
10930     SmallVector<ObjCIvarDecl*, 8> ivars;
10931     CollectIvarsToConstructOrDestruct(OID, ivars);
10932     if (ivars.empty())
10933       return;
10934     SmallVector<CXXCtorInitializer*, 32> AllToInit;
10935     for (unsigned i = 0; i < ivars.size(); i++) {
10936       FieldDecl *Field = ivars[i];
10937       if (Field->isInvalidDecl())
10938         continue;
10939 
10940       CXXCtorInitializer *Member;
10941       InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
10942       InitializationKind InitKind =
10943         InitializationKind::CreateDefault(ObjCImplementation->getLocation());
10944 
10945       InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);
10946       ExprResult MemberInit =
10947         InitSeq.Perform(*this, InitEntity, InitKind, MultiExprArg());
10948       MemberInit = MaybeCreateExprWithCleanups(MemberInit);
10949       // Note, MemberInit could actually come back empty if no initialization
10950       // is required (e.g., because it would call a trivial default constructor)
10951       if (!MemberInit.get() || MemberInit.isInvalid())
10952         continue;
10953 
10954       Member =
10955         new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
10956                                          SourceLocation(),
10957                                          MemberInit.takeAs<Expr>(),
10958                                          SourceLocation());
10959       AllToInit.push_back(Member);
10960 
10961       // Be sure that the destructor is accessible and is marked as referenced.
10962       if (const RecordType *RecordTy
10963                   = Context.getBaseElementType(Field->getType())
10964                                                         ->getAs<RecordType>()) {
10965                     CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
10966         if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
10967           MarkFunctionReferenced(Field->getLocation(), Destructor);
10968           CheckDestructorAccess(Field->getLocation(), Destructor,
10969                             PDiag(diag::err_access_dtor_ivar)
10970                               << Context.getBaseElementType(Field->getType()));
10971         }
10972       }
10973     }
10974     ObjCImplementation->setIvarInitializers(Context,
10975                                             AllToInit.data(), AllToInit.size());
10976   }
10977 }
10978 
10979 static
DelegatingCycleHelper(CXXConstructorDecl * Ctor,llvm::SmallSet<CXXConstructorDecl *,4> & Valid,llvm::SmallSet<CXXConstructorDecl *,4> & Invalid,llvm::SmallSet<CXXConstructorDecl *,4> & Current,Sema & S)10980 void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
10981                            llvm::SmallSet<CXXConstructorDecl*, 4> &Valid,
10982                            llvm::SmallSet<CXXConstructorDecl*, 4> &Invalid,
10983                            llvm::SmallSet<CXXConstructorDecl*, 4> &Current,
10984                            Sema &S) {
10985   llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
10986                                                    CE = Current.end();
10987   if (Ctor->isInvalidDecl())
10988     return;
10989 
10990   const FunctionDecl *FNTarget = 0;
10991   CXXConstructorDecl *Target;
10992 
10993   // We ignore the result here since if we don't have a body, Target will be
10994   // null below.
10995   (void)Ctor->getTargetConstructor()->hasBody(FNTarget);
10996   Target
10997 = const_cast<CXXConstructorDecl*>(cast_or_null<CXXConstructorDecl>(FNTarget));
10998 
10999   CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
11000                      // Avoid dereferencing a null pointer here.
11001                      *TCanonical = Target ? Target->getCanonicalDecl() : 0;
11002 
11003   if (!Current.insert(Canonical))
11004     return;
11005 
11006   // We know that beyond here, we aren't chaining into a cycle.
11007   if (!Target || !Target->isDelegatingConstructor() ||
11008       Target->isInvalidDecl() || Valid.count(TCanonical)) {
11009     for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
11010       Valid.insert(*CI);
11011     Current.clear();
11012   // We've hit a cycle.
11013   } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
11014              Current.count(TCanonical)) {
11015     // If we haven't diagnosed this cycle yet, do so now.
11016     if (!Invalid.count(TCanonical)) {
11017       S.Diag((*Ctor->init_begin())->getSourceLocation(),
11018              diag::warn_delegating_ctor_cycle)
11019         << Ctor;
11020 
11021       // Don't add a note for a function delegating directo to itself.
11022       if (TCanonical != Canonical)
11023         S.Diag(Target->getLocation(), diag::note_it_delegates_to);
11024 
11025       CXXConstructorDecl *C = Target;
11026       while (C->getCanonicalDecl() != Canonical) {
11027         (void)C->getTargetConstructor()->hasBody(FNTarget);
11028         assert(FNTarget && "Ctor cycle through bodiless function");
11029 
11030         C
11031        = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
11032         S.Diag(C->getLocation(), diag::note_which_delegates_to);
11033       }
11034     }
11035 
11036     for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
11037       Invalid.insert(*CI);
11038     Current.clear();
11039   } else {
11040     DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
11041   }
11042 }
11043 
11044 
CheckDelegatingCtorCycles()11045 void Sema::CheckDelegatingCtorCycles() {
11046   llvm::SmallSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
11047 
11048   llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
11049                                                    CE = Current.end();
11050 
11051   for (DelegatingCtorDeclsType::iterator
11052          I = DelegatingCtorDecls.begin(ExternalSource),
11053          E = DelegatingCtorDecls.end();
11054        I != E; ++I) {
11055    DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
11056   }
11057 
11058   for (CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
11059     (*CI)->setInvalidDecl();
11060 }
11061 
11062 namespace {
11063   /// \brief AST visitor that finds references to the 'this' expression.
11064   class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
11065     Sema &S;
11066 
11067   public:
FindCXXThisExpr(Sema & S)11068     explicit FindCXXThisExpr(Sema &S) : S(S) { }
11069 
VisitCXXThisExpr(CXXThisExpr * E)11070     bool VisitCXXThisExpr(CXXThisExpr *E) {
11071       S.Diag(E->getLocation(), diag::err_this_static_member_func)
11072         << E->isImplicit();
11073       return false;
11074     }
11075   };
11076 }
11077 
checkThisInStaticMemberFunctionType(CXXMethodDecl * Method)11078 bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
11079   TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
11080   if (!TSInfo)
11081     return false;
11082 
11083   TypeLoc TL = TSInfo->getTypeLoc();
11084   FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
11085   if (!ProtoTL)
11086     return false;
11087 
11088   // C++11 [expr.prim.general]p3:
11089   //   [The expression this] shall not appear before the optional
11090   //   cv-qualifier-seq and it shall not appear within the declaration of a
11091   //   static member function (although its type and value category are defined
11092   //   within a static member function as they are within a non-static member
11093   //   function). [ Note: this is because declaration matching does not occur
11094   //  until the complete declarator is known. — end note ]
11095   const FunctionProtoType *Proto = ProtoTL->getTypePtr();
11096   FindCXXThisExpr Finder(*this);
11097 
11098   // If the return type came after the cv-qualifier-seq, check it now.
11099   if (Proto->hasTrailingReturn() &&
11100       !Finder.TraverseTypeLoc(ProtoTL->getResultLoc()))
11101     return true;
11102 
11103   // Check the exception specification.
11104   if (checkThisInStaticMemberFunctionExceptionSpec(Method))
11105     return true;
11106 
11107   return checkThisInStaticMemberFunctionAttributes(Method);
11108 }
11109 
checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl * Method)11110 bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
11111   TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
11112   if (!TSInfo)
11113     return false;
11114 
11115   TypeLoc TL = TSInfo->getTypeLoc();
11116   FunctionProtoTypeLoc *ProtoTL = dyn_cast<FunctionProtoTypeLoc>(&TL);
11117   if (!ProtoTL)
11118     return false;
11119 
11120   const FunctionProtoType *Proto = ProtoTL->getTypePtr();
11121   FindCXXThisExpr Finder(*this);
11122 
11123   switch (Proto->getExceptionSpecType()) {
11124   case EST_Uninstantiated:
11125   case EST_BasicNoexcept:
11126   case EST_Delayed:
11127   case EST_DynamicNone:
11128   case EST_MSAny:
11129   case EST_None:
11130     break;
11131 
11132   case EST_ComputedNoexcept:
11133     if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
11134       return true;
11135 
11136   case EST_Dynamic:
11137     for (FunctionProtoType::exception_iterator E = Proto->exception_begin(),
11138          EEnd = Proto->exception_end();
11139          E != EEnd; ++E) {
11140       if (!Finder.TraverseType(*E))
11141         return true;
11142     }
11143     break;
11144   }
11145 
11146   return false;
11147 }
11148 
checkThisInStaticMemberFunctionAttributes(CXXMethodDecl * Method)11149 bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
11150   FindCXXThisExpr Finder(*this);
11151 
11152   // Check attributes.
11153   for (Decl::attr_iterator A = Method->attr_begin(), AEnd = Method->attr_end();
11154        A != AEnd; ++A) {
11155     // FIXME: This should be emitted by tblgen.
11156     Expr *Arg = 0;
11157     ArrayRef<Expr *> Args;
11158     if (GuardedByAttr *G = dyn_cast<GuardedByAttr>(*A))
11159       Arg = G->getArg();
11160     else if (PtGuardedByAttr *G = dyn_cast<PtGuardedByAttr>(*A))
11161       Arg = G->getArg();
11162     else if (AcquiredAfterAttr *AA = dyn_cast<AcquiredAfterAttr>(*A))
11163       Args = ArrayRef<Expr *>(AA->args_begin(), AA->args_size());
11164     else if (AcquiredBeforeAttr *AB = dyn_cast<AcquiredBeforeAttr>(*A))
11165       Args = ArrayRef<Expr *>(AB->args_begin(), AB->args_size());
11166     else if (ExclusiveLockFunctionAttr *ELF
11167                = dyn_cast<ExclusiveLockFunctionAttr>(*A))
11168       Args = ArrayRef<Expr *>(ELF->args_begin(), ELF->args_size());
11169     else if (SharedLockFunctionAttr *SLF
11170                = dyn_cast<SharedLockFunctionAttr>(*A))
11171       Args = ArrayRef<Expr *>(SLF->args_begin(), SLF->args_size());
11172     else if (ExclusiveTrylockFunctionAttr *ETLF
11173                = dyn_cast<ExclusiveTrylockFunctionAttr>(*A)) {
11174       Arg = ETLF->getSuccessValue();
11175       Args = ArrayRef<Expr *>(ETLF->args_begin(), ETLF->args_size());
11176     } else if (SharedTrylockFunctionAttr *STLF
11177                  = dyn_cast<SharedTrylockFunctionAttr>(*A)) {
11178       Arg = STLF->getSuccessValue();
11179       Args = ArrayRef<Expr *>(STLF->args_begin(), STLF->args_size());
11180     } else if (UnlockFunctionAttr *UF = dyn_cast<UnlockFunctionAttr>(*A))
11181       Args = ArrayRef<Expr *>(UF->args_begin(), UF->args_size());
11182     else if (LockReturnedAttr *LR = dyn_cast<LockReturnedAttr>(*A))
11183       Arg = LR->getArg();
11184     else if (LocksExcludedAttr *LE = dyn_cast<LocksExcludedAttr>(*A))
11185       Args = ArrayRef<Expr *>(LE->args_begin(), LE->args_size());
11186     else if (ExclusiveLocksRequiredAttr *ELR
11187                = dyn_cast<ExclusiveLocksRequiredAttr>(*A))
11188       Args = ArrayRef<Expr *>(ELR->args_begin(), ELR->args_size());
11189     else if (SharedLocksRequiredAttr *SLR
11190                = dyn_cast<SharedLocksRequiredAttr>(*A))
11191       Args = ArrayRef<Expr *>(SLR->args_begin(), SLR->args_size());
11192 
11193     if (Arg && !Finder.TraverseStmt(Arg))
11194       return true;
11195 
11196     for (unsigned I = 0, N = Args.size(); I != N; ++I) {
11197       if (!Finder.TraverseStmt(Args[I]))
11198         return true;
11199     }
11200   }
11201 
11202   return false;
11203 }
11204 
11205 void
checkExceptionSpecification(ExceptionSpecificationType EST,ArrayRef<ParsedType> DynamicExceptions,ArrayRef<SourceRange> DynamicExceptionRanges,Expr * NoexceptExpr,llvm::SmallVectorImpl<QualType> & Exceptions,FunctionProtoType::ExtProtoInfo & EPI)11206 Sema::checkExceptionSpecification(ExceptionSpecificationType EST,
11207                                   ArrayRef<ParsedType> DynamicExceptions,
11208                                   ArrayRef<SourceRange> DynamicExceptionRanges,
11209                                   Expr *NoexceptExpr,
11210                                   llvm::SmallVectorImpl<QualType> &Exceptions,
11211                                   FunctionProtoType::ExtProtoInfo &EPI) {
11212   Exceptions.clear();
11213   EPI.ExceptionSpecType = EST;
11214   if (EST == EST_Dynamic) {
11215     Exceptions.reserve(DynamicExceptions.size());
11216     for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
11217       // FIXME: Preserve type source info.
11218       QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
11219 
11220       SmallVector<UnexpandedParameterPack, 2> Unexpanded;
11221       collectUnexpandedParameterPacks(ET, Unexpanded);
11222       if (!Unexpanded.empty()) {
11223         DiagnoseUnexpandedParameterPacks(DynamicExceptionRanges[ei].getBegin(),
11224                                          UPPC_ExceptionType,
11225                                          Unexpanded);
11226         continue;
11227       }
11228 
11229       // Check that the type is valid for an exception spec, and
11230       // drop it if not.
11231       if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
11232         Exceptions.push_back(ET);
11233     }
11234     EPI.NumExceptions = Exceptions.size();
11235     EPI.Exceptions = Exceptions.data();
11236     return;
11237   }
11238 
11239   if (EST == EST_ComputedNoexcept) {
11240     // If an error occurred, there's no expression here.
11241     if (NoexceptExpr) {
11242       assert((NoexceptExpr->isTypeDependent() ||
11243               NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
11244               Context.BoolTy) &&
11245              "Parser should have made sure that the expression is boolean");
11246       if (NoexceptExpr && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
11247         EPI.ExceptionSpecType = EST_BasicNoexcept;
11248         return;
11249       }
11250 
11251       if (!NoexceptExpr->isValueDependent())
11252         NoexceptExpr = VerifyIntegerConstantExpression(NoexceptExpr, 0,
11253                          PDiag(diag::err_noexcept_needs_constant_expression),
11254                          /*AllowFold*/ false).take();
11255       EPI.NoexceptExpr = NoexceptExpr;
11256     }
11257     return;
11258   }
11259 }
11260 
actOnDelayedExceptionSpecification(Decl * MethodD,ExceptionSpecificationType EST,SourceRange SpecificationRange,ArrayRef<ParsedType> DynamicExceptions,ArrayRef<SourceRange> DynamicExceptionRanges,Expr * NoexceptExpr)11261 void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
11262              ExceptionSpecificationType EST,
11263              SourceRange SpecificationRange,
11264              ArrayRef<ParsedType> DynamicExceptions,
11265              ArrayRef<SourceRange> DynamicExceptionRanges,
11266              Expr *NoexceptExpr) {
11267   if (!MethodD)
11268     return;
11269 
11270   // Dig out the method we're referring to.
11271   CXXMethodDecl *Method = 0;
11272   if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
11273     Method = dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
11274   else
11275     Method = dyn_cast<CXXMethodDecl>(MethodD);
11276 
11277   if (!Method)
11278     return;
11279 
11280   // Dig out the prototype. This should never fail.
11281   const FunctionProtoType *Proto
11282     = dyn_cast<FunctionProtoType>(Method->getType());
11283   if (!Proto)
11284     return;
11285 
11286   // Check the exception specification.
11287   llvm::SmallVector<QualType, 4> Exceptions;
11288   FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
11289   checkExceptionSpecification(EST, DynamicExceptions, DynamicExceptionRanges,
11290                               NoexceptExpr, Exceptions, EPI);
11291 
11292   // Rebuild the function type.
11293   QualType T = Context.getFunctionType(Proto->getResultType(),
11294                                        Proto->arg_type_begin(),
11295                                        Proto->getNumArgs(),
11296                                        EPI);
11297   if (TypeSourceInfo *TSInfo = Method->getTypeSourceInfo()) {
11298     // FIXME: When we get proper type location information for exceptions,
11299     // we'll also have to rebuild the TypeSourceInfo. For now, we just patch
11300     // up the TypeSourceInfo;
11301     assert(TypeLoc::getFullDataSizeForType(T)
11302              == TypeLoc::getFullDataSizeForType(Method->getType()) &&
11303            "TypeLoc size mismatch with delayed exception specification");
11304     TSInfo->overrideType(T);
11305   }
11306 
11307   Method->setType(T);
11308 
11309   if (Method->isStatic())
11310     checkThisInStaticMemberFunctionExceptionSpec(Method);
11311 
11312   if (Method->isVirtual()) {
11313     // Check overrides, which we previously had to delay.
11314     for (CXXMethodDecl::method_iterator O = Method->begin_overridden_methods(),
11315                                      OEnd = Method->end_overridden_methods();
11316          O != OEnd; ++O)
11317       CheckOverridingFunctionExceptionSpec(Method, *O);
11318   }
11319 }
11320 
11321 /// IdentifyCUDATarget - Determine the CUDA compilation target for this function
IdentifyCUDATarget(const FunctionDecl * D)11322 Sema::CUDAFunctionTarget Sema::IdentifyCUDATarget(const FunctionDecl *D) {
11323   // Implicitly declared functions (e.g. copy constructors) are
11324   // __host__ __device__
11325   if (D->isImplicit())
11326     return CFT_HostDevice;
11327 
11328   if (D->hasAttr<CUDAGlobalAttr>())
11329     return CFT_Global;
11330 
11331   if (D->hasAttr<CUDADeviceAttr>()) {
11332     if (D->hasAttr<CUDAHostAttr>())
11333       return CFT_HostDevice;
11334     else
11335       return CFT_Device;
11336   }
11337 
11338   return CFT_Host;
11339 }
11340 
CheckCUDATarget(CUDAFunctionTarget CallerTarget,CUDAFunctionTarget CalleeTarget)11341 bool Sema::CheckCUDATarget(CUDAFunctionTarget CallerTarget,
11342                            CUDAFunctionTarget CalleeTarget) {
11343   // CUDA B.1.1 "The __device__ qualifier declares a function that is...
11344   // Callable from the device only."
11345   if (CallerTarget == CFT_Host && CalleeTarget == CFT_Device)
11346     return true;
11347 
11348   // CUDA B.1.2 "The __global__ qualifier declares a function that is...
11349   // Callable from the host only."
11350   // CUDA B.1.3 "The __host__ qualifier declares a function that is...
11351   // Callable from the host only."
11352   if ((CallerTarget == CFT_Device || CallerTarget == CFT_Global) &&
11353       (CalleeTarget == CFT_Host || CalleeTarget == CFT_Global))
11354     return true;
11355 
11356   if (CallerTarget == CFT_HostDevice && CalleeTarget != CFT_HostDevice)
11357     return true;
11358 
11359   return false;
11360 }
11361