1 //===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
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 the actions class which performs semantic analysis and
11 // builds an AST out of a parse stream.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "clang/Sema/SemaInternal.h"
16 #include "clang/Sema/DelayedDiagnostic.h"
17 #include "TargetAttributesSema.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/APFloat.h"
21 #include "llvm/Support/CrashRecoveryContext.h"
22 #include "clang/Sema/CXXFieldCollector.h"
23 #include "clang/Sema/TemplateDeduction.h"
24 #include "clang/Sema/ExternalSemaSource.h"
25 #include "clang/Sema/ObjCMethodList.h"
26 #include "clang/Sema/PrettyDeclStackTrace.h"
27 #include "clang/Sema/Scope.h"
28 #include "clang/Sema/ScopeInfo.h"
29 #include "clang/Sema/SemaConsumer.h"
30 #include "clang/AST/ASTContext.h"
31 #include "clang/AST/ASTDiagnostic.h"
32 #include "clang/AST/DeclCXX.h"
33 #include "clang/AST/DeclFriend.h"
34 #include "clang/AST/DeclObjC.h"
35 #include "clang/AST/Expr.h"
36 #include "clang/AST/ExprCXX.h"
37 #include "clang/AST/StmtCXX.h"
38 #include "clang/Lex/HeaderSearch.h"
39 #include "clang/Lex/Preprocessor.h"
40 #include "clang/Basic/FileManager.h"
41 #include "clang/Basic/PartialDiagnostic.h"
42 #include "clang/Basic/TargetInfo.h"
43 using namespace clang;
44 using namespace sema;
45
~FunctionScopeInfo()46 FunctionScopeInfo::~FunctionScopeInfo() { }
47
Clear()48 void FunctionScopeInfo::Clear() {
49 HasBranchProtectedScope = false;
50 HasBranchIntoScope = false;
51 HasIndirectGoto = false;
52
53 SwitchStack.clear();
54 Returns.clear();
55 ErrorTrap.reset();
56 PossiblyUnreachableDiags.clear();
57 }
58
~BlockScopeInfo()59 BlockScopeInfo::~BlockScopeInfo() { }
~LambdaScopeInfo()60 LambdaScopeInfo::~LambdaScopeInfo() { }
61
getPrintingPolicy(const ASTContext & Context,const Preprocessor & PP)62 PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context,
63 const Preprocessor &PP) {
64 PrintingPolicy Policy = Context.getPrintingPolicy();
65 Policy.Bool = Context.getLangOpts().Bool;
66 if (!Policy.Bool) {
67 if (MacroInfo *BoolMacro = PP.getMacroInfo(&Context.Idents.get("bool"))) {
68 Policy.Bool = BoolMacro->isObjectLike() &&
69 BoolMacro->getNumTokens() == 1 &&
70 BoolMacro->getReplacementToken(0).is(tok::kw__Bool);
71 }
72 }
73
74 return Policy;
75 }
76
ActOnTranslationUnitScope(Scope * S)77 void Sema::ActOnTranslationUnitScope(Scope *S) {
78 TUScope = S;
79 PushDeclContext(S, Context.getTranslationUnitDecl());
80
81 VAListTagName = PP.getIdentifierInfo("__va_list_tag");
82 }
83
Sema(Preprocessor & pp,ASTContext & ctxt,ASTConsumer & consumer,TranslationUnitKind TUKind,CodeCompleteConsumer * CodeCompleter)84 Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
85 TranslationUnitKind TUKind,
86 CodeCompleteConsumer *CodeCompleter)
87 : TheTargetAttributesSema(0), FPFeatures(pp.getLangOpts()),
88 LangOpts(pp.getLangOpts()), PP(pp), Context(ctxt), Consumer(consumer),
89 Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
90 CollectStats(false), ExternalSource(0), CodeCompleter(CodeCompleter),
91 CurContext(0), OriginalLexicalContext(0),
92 PackContext(0), MSStructPragmaOn(false), VisContext(0),
93 ExprNeedsCleanups(false), LateTemplateParser(0), OpaqueParser(0),
94 IdResolver(pp), StdInitializerList(0), CXXTypeInfoDecl(0), MSVCGuidDecl(0),
95 NSNumberDecl(0),
96 NSStringDecl(0), StringWithUTF8StringMethod(0),
97 NSArrayDecl(0), ArrayWithObjectsMethod(0),
98 NSDictionaryDecl(0), DictionaryWithObjectsMethod(0),
99 GlobalNewDeleteDeclared(false),
100 TUKind(TUKind),
101 NumSFINAEErrors(0), InFunctionDeclarator(0),
102 AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false),
103 NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1),
104 CurrentInstantiationScope(0), TyposCorrected(0),
105 AnalysisWarnings(*this)
106 {
107 TUScope = 0;
108
109 LoadedExternalKnownNamespaces = false;
110 for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
111 NSNumberLiteralMethods[I] = 0;
112
113 if (getLangOpts().ObjC1)
114 NSAPIObj.reset(new NSAPI(Context));
115
116 if (getLangOpts().CPlusPlus)
117 FieldCollector.reset(new CXXFieldCollector());
118
119 // Tell diagnostics how to render things from the AST library.
120 PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
121 &Context);
122
123 ExprEvalContexts.push_back(
124 ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0,
125 false, 0, false));
126
127 FunctionScopes.push_back(new FunctionScopeInfo(Diags));
128 }
129
Initialize()130 void Sema::Initialize() {
131 // Tell the AST consumer about this Sema object.
132 Consumer.Initialize(Context);
133
134 // FIXME: Isn't this redundant with the initialization above?
135 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
136 SC->InitializeSema(*this);
137
138 // Tell the external Sema source about this Sema object.
139 if (ExternalSemaSource *ExternalSema
140 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
141 ExternalSema->InitializeSema(*this);
142
143 // Initialize predefined 128-bit integer types, if needed.
144 if (PP.getTargetInfo().getPointerWidth(0) >= 64) {
145 // If either of the 128-bit integer types are unavailable to name lookup,
146 // define them now.
147 DeclarationName Int128 = &Context.Idents.get("__int128_t");
148 if (IdResolver.begin(Int128) == IdResolver.end())
149 PushOnScopeChains(Context.getInt128Decl(), TUScope);
150
151 DeclarationName UInt128 = &Context.Idents.get("__uint128_t");
152 if (IdResolver.begin(UInt128) == IdResolver.end())
153 PushOnScopeChains(Context.getUInt128Decl(), TUScope);
154 }
155
156
157 // Initialize predefined Objective-C types:
158 if (PP.getLangOpts().ObjC1) {
159 // If 'SEL' does not yet refer to any declarations, make it refer to the
160 // predefined 'SEL'.
161 DeclarationName SEL = &Context.Idents.get("SEL");
162 if (IdResolver.begin(SEL) == IdResolver.end())
163 PushOnScopeChains(Context.getObjCSelDecl(), TUScope);
164
165 // If 'id' does not yet refer to any declarations, make it refer to the
166 // predefined 'id'.
167 DeclarationName Id = &Context.Idents.get("id");
168 if (IdResolver.begin(Id) == IdResolver.end())
169 PushOnScopeChains(Context.getObjCIdDecl(), TUScope);
170
171 // Create the built-in typedef for 'Class'.
172 DeclarationName Class = &Context.Idents.get("Class");
173 if (IdResolver.begin(Class) == IdResolver.end())
174 PushOnScopeChains(Context.getObjCClassDecl(), TUScope);
175
176 // Create the built-in forward declaratino for 'Protocol'.
177 DeclarationName Protocol = &Context.Idents.get("Protocol");
178 if (IdResolver.begin(Protocol) == IdResolver.end())
179 PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
180 }
181
182 DeclarationName BuiltinVaList = &Context.Idents.get("__builtin_va_list");
183 if (IdResolver.begin(BuiltinVaList) == IdResolver.end())
184 PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope);
185 }
186
~Sema()187 Sema::~Sema() {
188 if (PackContext) FreePackedContext();
189 if (VisContext) FreeVisContext();
190 delete TheTargetAttributesSema;
191 MSStructPragmaOn = false;
192 // Kill all the active scopes.
193 for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I)
194 delete FunctionScopes[I];
195 if (FunctionScopes.size() == 1)
196 delete FunctionScopes[0];
197
198 // Tell the SemaConsumer to forget about us; we're going out of scope.
199 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
200 SC->ForgetSema();
201
202 // Detach from the external Sema source.
203 if (ExternalSemaSource *ExternalSema
204 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
205 ExternalSema->ForgetSema();
206 }
207
208 /// makeUnavailableInSystemHeader - There is an error in the current
209 /// context. If we're still in a system header, and we can plausibly
210 /// make the relevant declaration unavailable instead of erroring, do
211 /// so and return true.
makeUnavailableInSystemHeader(SourceLocation loc,StringRef msg)212 bool Sema::makeUnavailableInSystemHeader(SourceLocation loc,
213 StringRef msg) {
214 // If we're not in a function, it's an error.
215 FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext);
216 if (!fn) return false;
217
218 // If we're in template instantiation, it's an error.
219 if (!ActiveTemplateInstantiations.empty())
220 return false;
221
222 // If that function's not in a system header, it's an error.
223 if (!Context.getSourceManager().isInSystemHeader(loc))
224 return false;
225
226 // If the function is already unavailable, it's not an error.
227 if (fn->hasAttr<UnavailableAttr>()) return true;
228
229 fn->addAttr(new (Context) UnavailableAttr(loc, Context, msg));
230 return true;
231 }
232
getASTMutationListener() const233 ASTMutationListener *Sema::getASTMutationListener() const {
234 return getASTConsumer().GetASTMutationListener();
235 }
236
237 /// \brief Print out statistics about the semantic analysis.
PrintStats() const238 void Sema::PrintStats() const {
239 llvm::errs() << "\n*** Semantic Analysis Stats:\n";
240 llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n";
241
242 BumpAlloc.PrintStats();
243 AnalysisWarnings.PrintStats();
244 }
245
246 /// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
247 /// If there is already an implicit cast, merge into the existing one.
248 /// The result is of the given category.
ImpCastExprToType(Expr * E,QualType Ty,CastKind Kind,ExprValueKind VK,const CXXCastPath * BasePath,CheckedConversionKind CCK)249 ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
250 CastKind Kind, ExprValueKind VK,
251 const CXXCastPath *BasePath,
252 CheckedConversionKind CCK) {
253 #ifndef NDEBUG
254 if (VK == VK_RValue && !E->isRValue()) {
255 switch (Kind) {
256 default:
257 assert(0 && "can't implicitly cast lvalue to rvalue with this cast kind");
258 case CK_LValueToRValue:
259 case CK_ArrayToPointerDecay:
260 case CK_FunctionToPointerDecay:
261 case CK_ToVoid:
262 break;
263 }
264 }
265 assert((VK == VK_RValue || !E->isRValue()) && "can't cast rvalue to lvalue");
266 #endif
267
268 QualType ExprTy = Context.getCanonicalType(E->getType());
269 QualType TypeTy = Context.getCanonicalType(Ty);
270
271 if (ExprTy == TypeTy)
272 return Owned(E);
273
274 if (getLangOpts().ObjCAutoRefCount)
275 CheckObjCARCConversion(SourceRange(), Ty, E, CCK);
276
277 // If this is a derived-to-base cast to a through a virtual base, we
278 // need a vtable.
279 if (Kind == CK_DerivedToBase &&
280 BasePathInvolvesVirtualBase(*BasePath)) {
281 QualType T = E->getType();
282 if (const PointerType *Pointer = T->getAs<PointerType>())
283 T = Pointer->getPointeeType();
284 if (const RecordType *RecordTy = T->getAs<RecordType>())
285 MarkVTableUsed(E->getLocStart(),
286 cast<CXXRecordDecl>(RecordTy->getDecl()));
287 }
288
289 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
290 if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
291 ImpCast->setType(Ty);
292 ImpCast->setValueKind(VK);
293 return Owned(E);
294 }
295 }
296
297 return Owned(ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK));
298 }
299
300 /// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
301 /// to the conversion from scalar type ScalarTy to the Boolean type.
ScalarTypeToBooleanCastKind(QualType ScalarTy)302 CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
303 switch (ScalarTy->getScalarTypeKind()) {
304 case Type::STK_Bool: return CK_NoOp;
305 case Type::STK_CPointer: return CK_PointerToBoolean;
306 case Type::STK_BlockPointer: return CK_PointerToBoolean;
307 case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean;
308 case Type::STK_MemberPointer: return CK_MemberPointerToBoolean;
309 case Type::STK_Integral: return CK_IntegralToBoolean;
310 case Type::STK_Floating: return CK_FloatingToBoolean;
311 case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean;
312 case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean;
313 }
314 return CK_Invalid;
315 }
316
317 /// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
ShouldRemoveFromUnused(Sema * SemaRef,const DeclaratorDecl * D)318 static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
319 if (D->isUsed())
320 return true;
321
322 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
323 // UnusedFileScopedDecls stores the first declaration.
324 // The declaration may have become definition so check again.
325 const FunctionDecl *DeclToCheck;
326 if (FD->hasBody(DeclToCheck))
327 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
328
329 // Later redecls may add new information resulting in not having to warn,
330 // so check again.
331 DeclToCheck = FD->getMostRecentDecl();
332 if (DeclToCheck != FD)
333 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
334 }
335
336 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
337 // UnusedFileScopedDecls stores the first declaration.
338 // The declaration may have become definition so check again.
339 const VarDecl *DeclToCheck = VD->getDefinition();
340 if (DeclToCheck)
341 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
342
343 // Later redecls may add new information resulting in not having to warn,
344 // so check again.
345 DeclToCheck = VD->getMostRecentDecl();
346 if (DeclToCheck != VD)
347 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
348 }
349
350 return false;
351 }
352
353 namespace {
354 struct UndefinedInternal {
355 NamedDecl *decl;
356 FullSourceLoc useLoc;
357
UndefinedInternal__anon461fb15d0111::UndefinedInternal358 UndefinedInternal(NamedDecl *decl, FullSourceLoc useLoc)
359 : decl(decl), useLoc(useLoc) {}
360 };
361
operator <(const UndefinedInternal & l,const UndefinedInternal & r)362 bool operator<(const UndefinedInternal &l, const UndefinedInternal &r) {
363 return l.useLoc.isBeforeInTranslationUnitThan(r.useLoc);
364 }
365 }
366
367 /// checkUndefinedInternals - Check for undefined objects with internal linkage.
checkUndefinedInternals(Sema & S)368 static void checkUndefinedInternals(Sema &S) {
369 if (S.UndefinedInternals.empty()) return;
370
371 // Collect all the still-undefined entities with internal linkage.
372 SmallVector<UndefinedInternal, 16> undefined;
373 for (llvm::DenseMap<NamedDecl*,SourceLocation>::iterator
374 i = S.UndefinedInternals.begin(), e = S.UndefinedInternals.end();
375 i != e; ++i) {
376 NamedDecl *decl = i->first;
377
378 // Ignore attributes that have become invalid.
379 if (decl->isInvalidDecl()) continue;
380
381 // __attribute__((weakref)) is basically a definition.
382 if (decl->hasAttr<WeakRefAttr>()) continue;
383
384 if (FunctionDecl *fn = dyn_cast<FunctionDecl>(decl)) {
385 if (fn->isPure() || fn->hasBody())
386 continue;
387 } else {
388 if (cast<VarDecl>(decl)->hasDefinition() != VarDecl::DeclarationOnly)
389 continue;
390 }
391
392 // We build a FullSourceLoc so that we can sort with array_pod_sort.
393 FullSourceLoc loc(i->second, S.Context.getSourceManager());
394 undefined.push_back(UndefinedInternal(decl, loc));
395 }
396
397 if (undefined.empty()) return;
398
399 // Sort (in order of use site) so that we're not (as) dependent on
400 // the iteration order through an llvm::DenseMap.
401 llvm::array_pod_sort(undefined.begin(), undefined.end());
402
403 for (SmallVectorImpl<UndefinedInternal>::iterator
404 i = undefined.begin(), e = undefined.end(); i != e; ++i) {
405 NamedDecl *decl = i->decl;
406 S.Diag(decl->getLocation(), diag::warn_undefined_internal)
407 << isa<VarDecl>(decl) << decl;
408 S.Diag(i->useLoc, diag::note_used_here);
409 }
410 }
411
LoadExternalWeakUndeclaredIdentifiers()412 void Sema::LoadExternalWeakUndeclaredIdentifiers() {
413 if (!ExternalSource)
414 return;
415
416 SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs;
417 ExternalSource->ReadWeakUndeclaredIdentifiers(WeakIDs);
418 for (unsigned I = 0, N = WeakIDs.size(); I != N; ++I) {
419 llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator Pos
420 = WeakUndeclaredIdentifiers.find(WeakIDs[I].first);
421 if (Pos != WeakUndeclaredIdentifiers.end())
422 continue;
423
424 WeakUndeclaredIdentifiers.insert(WeakIDs[I]);
425 }
426 }
427
428
429 typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap;
430
431 /// \brief Returns true, if all methods and nested classes of the given
432 /// CXXRecordDecl are defined in this translation unit.
433 ///
434 /// Should only be called from ActOnEndOfTranslationUnit so that all
435 /// definitions are actually read.
MethodsAndNestedClassesComplete(const CXXRecordDecl * RD,RecordCompleteMap & MNCComplete)436 static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD,
437 RecordCompleteMap &MNCComplete) {
438 RecordCompleteMap::iterator Cache = MNCComplete.find(RD);
439 if (Cache != MNCComplete.end())
440 return Cache->second;
441 if (!RD->isCompleteDefinition())
442 return false;
443 bool Complete = true;
444 for (DeclContext::decl_iterator I = RD->decls_begin(),
445 E = RD->decls_end();
446 I != E && Complete; ++I) {
447 if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(*I))
448 Complete = M->isDefined() || (M->isPure() && !isa<CXXDestructorDecl>(M));
449 else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(*I))
450 Complete = F->getTemplatedDecl()->isDefined();
451 else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(*I)) {
452 if (R->isInjectedClassName())
453 continue;
454 if (R->hasDefinition())
455 Complete = MethodsAndNestedClassesComplete(R->getDefinition(),
456 MNCComplete);
457 else
458 Complete = false;
459 }
460 }
461 MNCComplete[RD] = Complete;
462 return Complete;
463 }
464
465 /// \brief Returns true, if the given CXXRecordDecl is fully defined in this
466 /// translation unit, i.e. all methods are defined or pure virtual and all
467 /// friends, friend functions and nested classes are fully defined in this
468 /// translation unit.
469 ///
470 /// Should only be called from ActOnEndOfTranslationUnit so that all
471 /// definitions are actually read.
IsRecordFullyDefined(const CXXRecordDecl * RD,RecordCompleteMap & RecordsComplete,RecordCompleteMap & MNCComplete)472 static bool IsRecordFullyDefined(const CXXRecordDecl *RD,
473 RecordCompleteMap &RecordsComplete,
474 RecordCompleteMap &MNCComplete) {
475 RecordCompleteMap::iterator Cache = RecordsComplete.find(RD);
476 if (Cache != RecordsComplete.end())
477 return Cache->second;
478 bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete);
479 for (CXXRecordDecl::friend_iterator I = RD->friend_begin(),
480 E = RD->friend_end();
481 I != E && Complete; ++I) {
482 // Check if friend classes and methods are complete.
483 if (TypeSourceInfo *TSI = (*I)->getFriendType()) {
484 // Friend classes are available as the TypeSourceInfo of the FriendDecl.
485 if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl())
486 Complete = MethodsAndNestedClassesComplete(FriendD, MNCComplete);
487 else
488 Complete = false;
489 } else {
490 // Friend functions are available through the NamedDecl of FriendDecl.
491 if (const FunctionDecl *FD =
492 dyn_cast<FunctionDecl>((*I)->getFriendDecl()))
493 Complete = FD->isDefined();
494 else
495 // This is a template friend, give up.
496 Complete = false;
497 }
498 }
499 RecordsComplete[RD] = Complete;
500 return Complete;
501 }
502
503 /// ActOnEndOfTranslationUnit - This is called at the very end of the
504 /// translation unit when EOF is reached and all but the top-level scope is
505 /// popped.
ActOnEndOfTranslationUnit()506 void Sema::ActOnEndOfTranslationUnit() {
507 assert(DelayedDiagnostics.getCurrentPool() == NULL
508 && "reached end of translation unit with a pool attached?");
509
510 // If code completion is enabled, don't perform any end-of-translation-unit
511 // work.
512 if (PP.isCodeCompletionEnabled())
513 return;
514
515 // Only complete translation units define vtables and perform implicit
516 // instantiations.
517 if (TUKind == TU_Complete) {
518 DiagnoseUseOfUnimplementedSelectors();
519
520 // If any dynamic classes have their key function defined within
521 // this translation unit, then those vtables are considered "used" and must
522 // be emitted.
523 for (DynamicClassesType::iterator I = DynamicClasses.begin(ExternalSource),
524 E = DynamicClasses.end();
525 I != E; ++I) {
526 assert(!(*I)->isDependentType() &&
527 "Should not see dependent types here!");
528 if (const CXXMethodDecl *KeyFunction = Context.getKeyFunction(*I)) {
529 const FunctionDecl *Definition = 0;
530 if (KeyFunction->hasBody(Definition))
531 MarkVTableUsed(Definition->getLocation(), *I, true);
532 }
533 }
534
535 // If DefinedUsedVTables ends up marking any virtual member functions it
536 // might lead to more pending template instantiations, which we then need
537 // to instantiate.
538 DefineUsedVTables();
539
540 // C++: Perform implicit template instantiations.
541 //
542 // FIXME: When we perform these implicit instantiations, we do not
543 // carefully keep track of the point of instantiation (C++ [temp.point]).
544 // This means that name lookup that occurs within the template
545 // instantiation will always happen at the end of the translation unit,
546 // so it will find some names that should not be found. Although this is
547 // common behavior for C++ compilers, it is technically wrong. In the
548 // future, we either need to be able to filter the results of name lookup
549 // or we need to perform template instantiations earlier.
550 PerformPendingInstantiations();
551 }
552
553 // Remove file scoped decls that turned out to be used.
554 UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(0,
555 true),
556 UnusedFileScopedDecls.end(),
557 std::bind1st(std::ptr_fun(ShouldRemoveFromUnused),
558 this)),
559 UnusedFileScopedDecls.end());
560
561 if (TUKind == TU_Prefix) {
562 // Translation unit prefixes don't need any of the checking below.
563 TUScope = 0;
564 return;
565 }
566
567 // Check for #pragma weak identifiers that were never declared
568 // FIXME: This will cause diagnostics to be emitted in a non-determinstic
569 // order! Iterating over a densemap like this is bad.
570 LoadExternalWeakUndeclaredIdentifiers();
571 for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
572 I = WeakUndeclaredIdentifiers.begin(),
573 E = WeakUndeclaredIdentifiers.end(); I != E; ++I) {
574 if (I->second.getUsed()) continue;
575
576 Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared)
577 << I->first;
578 }
579
580 if (TUKind == TU_Module) {
581 // If we are building a module, resolve all of the exported declarations
582 // now.
583 if (Module *CurrentModule = PP.getCurrentModule()) {
584 ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
585
586 llvm::SmallVector<Module *, 2> Stack;
587 Stack.push_back(CurrentModule);
588 while (!Stack.empty()) {
589 Module *Mod = Stack.back();
590 Stack.pop_back();
591
592 // Resolve the exported declarations.
593 // FIXME: Actually complain, once we figure out how to teach the
594 // diagnostic client to deal with complains in the module map at this
595 // point.
596 ModMap.resolveExports(Mod, /*Complain=*/false);
597
598 // Queue the submodules, so their exports will also be resolved.
599 for (Module::submodule_iterator Sub = Mod->submodule_begin(),
600 SubEnd = Mod->submodule_end();
601 Sub != SubEnd; ++Sub) {
602 Stack.push_back(*Sub);
603 }
604 }
605 }
606
607 // Modules don't need any of the checking below.
608 TUScope = 0;
609 return;
610 }
611
612 // C99 6.9.2p2:
613 // A declaration of an identifier for an object that has file
614 // scope without an initializer, and without a storage-class
615 // specifier or with the storage-class specifier static,
616 // constitutes a tentative definition. If a translation unit
617 // contains one or more tentative definitions for an identifier,
618 // and the translation unit contains no external definition for
619 // that identifier, then the behavior is exactly as if the
620 // translation unit contains a file scope declaration of that
621 // identifier, with the composite type as of the end of the
622 // translation unit, with an initializer equal to 0.
623 llvm::SmallSet<VarDecl *, 32> Seen;
624 for (TentativeDefinitionsType::iterator
625 T = TentativeDefinitions.begin(ExternalSource),
626 TEnd = TentativeDefinitions.end();
627 T != TEnd; ++T)
628 {
629 VarDecl *VD = (*T)->getActingDefinition();
630
631 // If the tentative definition was completed, getActingDefinition() returns
632 // null. If we've already seen this variable before, insert()'s second
633 // return value is false.
634 if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD))
635 continue;
636
637 if (const IncompleteArrayType *ArrayT
638 = Context.getAsIncompleteArrayType(VD->getType())) {
639 if (RequireCompleteType(VD->getLocation(),
640 ArrayT->getElementType(),
641 diag::err_tentative_def_incomplete_type_arr)) {
642 VD->setInvalidDecl();
643 continue;
644 }
645
646 // Set the length of the array to 1 (C99 6.9.2p5).
647 Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
648 llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true);
649 QualType T = Context.getConstantArrayType(ArrayT->getElementType(),
650 One, ArrayType::Normal, 0);
651 VD->setType(T);
652 } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
653 diag::err_tentative_def_incomplete_type))
654 VD->setInvalidDecl();
655
656 // Notify the consumer that we've completed a tentative definition.
657 if (!VD->isInvalidDecl())
658 Consumer.CompleteTentativeDefinition(VD);
659
660 }
661
662 if (LangOpts.CPlusPlus0x &&
663 Diags.getDiagnosticLevel(diag::warn_delegating_ctor_cycle,
664 SourceLocation())
665 != DiagnosticsEngine::Ignored)
666 CheckDelegatingCtorCycles();
667
668 // If there were errors, disable 'unused' warnings since they will mostly be
669 // noise.
670 if (!Diags.hasErrorOccurred()) {
671 // Output warning for unused file scoped decls.
672 for (UnusedFileScopedDeclsType::iterator
673 I = UnusedFileScopedDecls.begin(ExternalSource),
674 E = UnusedFileScopedDecls.end(); I != E; ++I) {
675 if (ShouldRemoveFromUnused(this, *I))
676 continue;
677
678 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
679 const FunctionDecl *DiagD;
680 if (!FD->hasBody(DiagD))
681 DiagD = FD;
682 if (DiagD->isDeleted())
683 continue; // Deleted functions are supposed to be unused.
684 if (DiagD->isReferenced()) {
685 if (isa<CXXMethodDecl>(DiagD))
686 Diag(DiagD->getLocation(), diag::warn_unneeded_member_function)
687 << DiagD->getDeclName();
688 else {
689 if (FD->getStorageClassAsWritten() == SC_Static &&
690 !FD->isInlineSpecified() &&
691 !SourceMgr.isFromMainFile(
692 SourceMgr.getExpansionLoc(FD->getLocation())))
693 Diag(DiagD->getLocation(), diag::warn_unneeded_static_internal_decl)
694 << DiagD->getDeclName();
695 else
696 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
697 << /*function*/0 << DiagD->getDeclName();
698 }
699 } else {
700 Diag(DiagD->getLocation(),
701 isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
702 : diag::warn_unused_function)
703 << DiagD->getDeclName();
704 }
705 } else {
706 const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
707 if (!DiagD)
708 DiagD = cast<VarDecl>(*I);
709 if (DiagD->isReferenced()) {
710 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
711 << /*variable*/1 << DiagD->getDeclName();
712 } else {
713 Diag(DiagD->getLocation(), diag::warn_unused_variable)
714 << DiagD->getDeclName();
715 }
716 }
717 }
718
719 checkUndefinedInternals(*this);
720 }
721
722 if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
723 SourceLocation())
724 != DiagnosticsEngine::Ignored) {
725 RecordCompleteMap RecordsComplete;
726 RecordCompleteMap MNCComplete;
727 for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(),
728 E = UnusedPrivateFields.end(); I != E; ++I) {
729 const NamedDecl *D = *I;
730 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
731 if (RD && !RD->isUnion() &&
732 IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) {
733 Diag(D->getLocation(), diag::warn_unused_private_field)
734 << D->getDeclName();
735 }
736 }
737 }
738
739 // Check we've noticed that we're no longer parsing the initializer for every
740 // variable. If we miss cases, then at best we have a performance issue and
741 // at worst a rejects-valid bug.
742 assert(ParsingInitForAutoVars.empty() &&
743 "Didn't unmark var as having its initializer parsed");
744
745 TUScope = 0;
746 }
747
748
749 //===----------------------------------------------------------------------===//
750 // Helper functions.
751 //===----------------------------------------------------------------------===//
752
getFunctionLevelDeclContext()753 DeclContext *Sema::getFunctionLevelDeclContext() {
754 DeclContext *DC = CurContext;
755
756 while (true) {
757 if (isa<BlockDecl>(DC) || isa<EnumDecl>(DC)) {
758 DC = DC->getParent();
759 } else if (isa<CXXMethodDecl>(DC) &&
760 cast<CXXMethodDecl>(DC)->getOverloadedOperator() == OO_Call &&
761 cast<CXXRecordDecl>(DC->getParent())->isLambda()) {
762 DC = DC->getParent()->getParent();
763 }
764 else break;
765 }
766
767 return DC;
768 }
769
770 /// getCurFunctionDecl - If inside of a function body, this returns a pointer
771 /// to the function decl for the function being parsed. If we're currently
772 /// in a 'block', this returns the containing context.
getCurFunctionDecl()773 FunctionDecl *Sema::getCurFunctionDecl() {
774 DeclContext *DC = getFunctionLevelDeclContext();
775 return dyn_cast<FunctionDecl>(DC);
776 }
777
getCurMethodDecl()778 ObjCMethodDecl *Sema::getCurMethodDecl() {
779 DeclContext *DC = getFunctionLevelDeclContext();
780 return dyn_cast<ObjCMethodDecl>(DC);
781 }
782
getCurFunctionOrMethodDecl()783 NamedDecl *Sema::getCurFunctionOrMethodDecl() {
784 DeclContext *DC = getFunctionLevelDeclContext();
785 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
786 return cast<NamedDecl>(DC);
787 return 0;
788 }
789
EmitCurrentDiagnostic(unsigned DiagID)790 void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
791 // FIXME: It doesn't make sense to me that DiagID is an incoming argument here
792 // and yet we also use the current diag ID on the DiagnosticsEngine. This has
793 // been made more painfully obvious by the refactor that introduced this
794 // function, but it is possible that the incoming argument can be
795 // eliminnated. If it truly cannot be (for example, there is some reentrancy
796 // issue I am not seeing yet), then there should at least be a clarifying
797 // comment somewhere.
798 if (llvm::Optional<TemplateDeductionInfo*> Info = isSFINAEContext()) {
799 switch (DiagnosticIDs::getDiagnosticSFINAEResponse(
800 Diags.getCurrentDiagID())) {
801 case DiagnosticIDs::SFINAE_Report:
802 // We'll report the diagnostic below.
803 break;
804
805 case DiagnosticIDs::SFINAE_SubstitutionFailure:
806 // Count this failure so that we know that template argument deduction
807 // has failed.
808 ++NumSFINAEErrors;
809
810 // Make a copy of this suppressed diagnostic and store it with the
811 // template-deduction information.
812 if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
813 Diagnostic DiagInfo(&Diags);
814 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
815 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
816 }
817
818 Diags.setLastDiagnosticIgnored();
819 Diags.Clear();
820 return;
821
822 case DiagnosticIDs::SFINAE_AccessControl: {
823 // Per C++ Core Issue 1170, access control is part of SFINAE.
824 // Additionally, the AccessCheckingSFINAE flag can be used to temporarily
825 // make access control a part of SFINAE for the purposes of checking
826 // type traits.
827 if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus0x)
828 break;
829
830 SourceLocation Loc = Diags.getCurrentDiagLoc();
831
832 // Suppress this diagnostic.
833 ++NumSFINAEErrors;
834
835 // Make a copy of this suppressed diagnostic and store it with the
836 // template-deduction information.
837 if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
838 Diagnostic DiagInfo(&Diags);
839 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
840 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
841 }
842
843 Diags.setLastDiagnosticIgnored();
844 Diags.Clear();
845
846 // Now the diagnostic state is clear, produce a C++98 compatibility
847 // warning.
848 Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
849
850 // The last diagnostic which Sema produced was ignored. Suppress any
851 // notes attached to it.
852 Diags.setLastDiagnosticIgnored();
853 return;
854 }
855
856 case DiagnosticIDs::SFINAE_Suppress:
857 // Make a copy of this suppressed diagnostic and store it with the
858 // template-deduction information;
859 if (*Info) {
860 Diagnostic DiagInfo(&Diags);
861 (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(),
862 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
863 }
864
865 // Suppress this diagnostic.
866 Diags.setLastDiagnosticIgnored();
867 Diags.Clear();
868 return;
869 }
870 }
871
872 // Set up the context's printing policy based on our current state.
873 Context.setPrintingPolicy(getPrintingPolicy());
874
875 // Emit the diagnostic.
876 if (!Diags.EmitCurrentDiagnostic())
877 return;
878
879 // If this is not a note, and we're in a template instantiation
880 // that is different from the last template instantiation where
881 // we emitted an error, print a template instantiation
882 // backtrace.
883 if (!DiagnosticIDs::isBuiltinNote(DiagID) &&
884 !ActiveTemplateInstantiations.empty() &&
885 ActiveTemplateInstantiations.back()
886 != LastTemplateInstantiationErrorContext) {
887 PrintInstantiationStack();
888 LastTemplateInstantiationErrorContext = ActiveTemplateInstantiations.back();
889 }
890 }
891
892 Sema::SemaDiagnosticBuilder
Diag(SourceLocation Loc,const PartialDiagnostic & PD)893 Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
894 SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID()));
895 PD.Emit(Builder);
896
897 return Builder;
898 }
899
900 /// \brief Looks through the macro-expansion chain for the given
901 /// location, looking for a macro expansion with the given name.
902 /// If one is found, returns true and sets the location to that
903 /// expansion loc.
findMacroSpelling(SourceLocation & locref,StringRef name)904 bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) {
905 SourceLocation loc = locref;
906 if (!loc.isMacroID()) return false;
907
908 // There's no good way right now to look at the intermediate
909 // expansions, so just jump to the expansion location.
910 loc = getSourceManager().getExpansionLoc(loc);
911
912 // If that's written with the name, stop here.
913 SmallVector<char, 16> buffer;
914 if (getPreprocessor().getSpelling(loc, buffer) == name) {
915 locref = loc;
916 return true;
917 }
918 return false;
919 }
920
921 /// \brief Determines the active Scope associated with the given declaration
922 /// context.
923 ///
924 /// This routine maps a declaration context to the active Scope object that
925 /// represents that declaration context in the parser. It is typically used
926 /// from "scope-less" code (e.g., template instantiation, lazy creation of
927 /// declarations) that injects a name for name-lookup purposes and, therefore,
928 /// must update the Scope.
929 ///
930 /// \returns The scope corresponding to the given declaraion context, or NULL
931 /// if no such scope is open.
getScopeForContext(DeclContext * Ctx)932 Scope *Sema::getScopeForContext(DeclContext *Ctx) {
933
934 if (!Ctx)
935 return 0;
936
937 Ctx = Ctx->getPrimaryContext();
938 for (Scope *S = getCurScope(); S; S = S->getParent()) {
939 // Ignore scopes that cannot have declarations. This is important for
940 // out-of-line definitions of static class members.
941 if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope))
942 if (DeclContext *Entity = static_cast<DeclContext *> (S->getEntity()))
943 if (Ctx == Entity->getPrimaryContext())
944 return S;
945 }
946
947 return 0;
948 }
949
950 /// \brief Enter a new function scope
PushFunctionScope()951 void Sema::PushFunctionScope() {
952 if (FunctionScopes.size() == 1) {
953 // Use the "top" function scope rather than having to allocate
954 // memory for a new scope.
955 FunctionScopes.back()->Clear();
956 FunctionScopes.push_back(FunctionScopes.back());
957 return;
958 }
959
960 FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics()));
961 }
962
PushBlockScope(Scope * BlockScope,BlockDecl * Block)963 void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
964 FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
965 BlockScope, Block));
966 }
967
PushLambdaScope(CXXRecordDecl * Lambda,CXXMethodDecl * CallOperator)968 void Sema::PushLambdaScope(CXXRecordDecl *Lambda,
969 CXXMethodDecl *CallOperator) {
970 FunctionScopes.push_back(new LambdaScopeInfo(getDiagnostics(), Lambda,
971 CallOperator));
972 }
973
PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy * WP,const Decl * D,const BlockExpr * blkExpr)974 void Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
975 const Decl *D, const BlockExpr *blkExpr) {
976 FunctionScopeInfo *Scope = FunctionScopes.pop_back_val();
977 assert(!FunctionScopes.empty() && "mismatched push/pop!");
978
979 // Issue any analysis-based warnings.
980 if (WP && D)
981 AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr);
982 else {
983 for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
984 i = Scope->PossiblyUnreachableDiags.begin(),
985 e = Scope->PossiblyUnreachableDiags.end();
986 i != e; ++i) {
987 const sema::PossiblyUnreachableDiag &D = *i;
988 Diag(D.Loc, D.PD);
989 }
990 }
991
992 if (FunctionScopes.back() != Scope) {
993 delete Scope;
994 }
995 }
996
PushCompoundScope()997 void Sema::PushCompoundScope() {
998 getCurFunction()->CompoundScopes.push_back(CompoundScopeInfo());
999 }
1000
PopCompoundScope()1001 void Sema::PopCompoundScope() {
1002 FunctionScopeInfo *CurFunction = getCurFunction();
1003 assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop");
1004
1005 CurFunction->CompoundScopes.pop_back();
1006 }
1007
1008 /// \brief Determine whether any errors occurred within this function/method/
1009 /// block.
hasAnyUnrecoverableErrorsInThisFunction() const1010 bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const {
1011 return getCurFunction()->ErrorTrap.hasUnrecoverableErrorOccurred();
1012 }
1013
getCurBlock()1014 BlockScopeInfo *Sema::getCurBlock() {
1015 if (FunctionScopes.empty())
1016 return 0;
1017
1018 return dyn_cast<BlockScopeInfo>(FunctionScopes.back());
1019 }
1020
getCurLambda()1021 LambdaScopeInfo *Sema::getCurLambda() {
1022 if (FunctionScopes.empty())
1023 return 0;
1024
1025 return dyn_cast<LambdaScopeInfo>(FunctionScopes.back());
1026 }
1027
ActOnComment(SourceRange Comment)1028 void Sema::ActOnComment(SourceRange Comment) {
1029 RawComment RC(SourceMgr, Comment);
1030 if (RC.isAlmostTrailingComment()) {
1031 SourceRange MagicMarkerRange(Comment.getBegin(),
1032 Comment.getBegin().getLocWithOffset(3));
1033 StringRef MagicMarkerText;
1034 switch (RC.getKind()) {
1035 case RawComment::RCK_OrdinaryBCPL:
1036 MagicMarkerText = "///<";
1037 break;
1038 case RawComment::RCK_OrdinaryC:
1039 MagicMarkerText = "/**<";
1040 break;
1041 default:
1042 llvm_unreachable("if this is an almost Doxygen comment, "
1043 "it should be ordinary");
1044 }
1045 Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) <<
1046 FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText);
1047 }
1048 Context.addComment(RC);
1049 }
1050
1051 // Pin this vtable to this file.
~ExternalSemaSource()1052 ExternalSemaSource::~ExternalSemaSource() {}
1053
ReadMethodPool(Selector Sel)1054 void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
1055
ReadKnownNamespaces(SmallVectorImpl<NamespaceDecl * > & Namespaces)1056 void ExternalSemaSource::ReadKnownNamespaces(
1057 SmallVectorImpl<NamespaceDecl *> &Namespaces) {
1058 }
1059
print(raw_ostream & OS) const1060 void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const {
1061 SourceLocation Loc = this->Loc;
1062 if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
1063 if (Loc.isValid()) {
1064 Loc.print(OS, S.getSourceManager());
1065 OS << ": ";
1066 }
1067 OS << Message;
1068
1069 if (TheDecl && isa<NamedDecl>(TheDecl)) {
1070 std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString();
1071 if (!Name.empty())
1072 OS << " '" << Name << '\'';
1073 }
1074
1075 OS << '\n';
1076 }
1077
1078 /// \brief Figure out if an expression could be turned into a call.
1079 ///
1080 /// Use this when trying to recover from an error where the programmer may have
1081 /// written just the name of a function instead of actually calling it.
1082 ///
1083 /// \param E - The expression to examine.
1084 /// \param ZeroArgCallReturnTy - If the expression can be turned into a call
1085 /// with no arguments, this parameter is set to the type returned by such a
1086 /// call; otherwise, it is set to an empty QualType.
1087 /// \param OverloadSet - If the expression is an overloaded function
1088 /// name, this parameter is populated with the decls of the various overloads.
isExprCallable(const Expr & E,QualType & ZeroArgCallReturnTy,UnresolvedSetImpl & OverloadSet)1089 bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
1090 UnresolvedSetImpl &OverloadSet) {
1091 ZeroArgCallReturnTy = QualType();
1092 OverloadSet.clear();
1093
1094 if (E.getType() == Context.OverloadTy) {
1095 OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
1096 const OverloadExpr *Overloads = FR.Expression;
1097
1098 for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
1099 DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
1100 OverloadSet.addDecl(*it);
1101
1102 // Check whether the function is a non-template which takes no
1103 // arguments.
1104 if (const FunctionDecl *OverloadDecl
1105 = dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
1106 if (OverloadDecl->getMinRequiredArguments() == 0)
1107 ZeroArgCallReturnTy = OverloadDecl->getResultType();
1108 }
1109 }
1110
1111 // Ignore overloads that are pointer-to-member constants.
1112 if (FR.HasFormOfMemberPointer)
1113 return false;
1114
1115 return true;
1116 }
1117
1118 if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
1119 if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
1120 if (Fun->getMinRequiredArguments() == 0)
1121 ZeroArgCallReturnTy = Fun->getResultType();
1122 return true;
1123 }
1124 }
1125
1126 // We don't have an expression that's convenient to get a FunctionDecl from,
1127 // but we can at least check if the type is "function of 0 arguments".
1128 QualType ExprTy = E.getType();
1129 const FunctionType *FunTy = NULL;
1130 QualType PointeeTy = ExprTy->getPointeeType();
1131 if (!PointeeTy.isNull())
1132 FunTy = PointeeTy->getAs<FunctionType>();
1133 if (!FunTy)
1134 FunTy = ExprTy->getAs<FunctionType>();
1135 if (!FunTy && ExprTy == Context.BoundMemberTy) {
1136 // Look for the bound-member type. If it's still overloaded, give up,
1137 // although we probably should have fallen into the OverloadExpr case above
1138 // if we actually have an overloaded bound member.
1139 QualType BoundMemberTy = Expr::findBoundMemberType(&E);
1140 if (!BoundMemberTy.isNull())
1141 FunTy = BoundMemberTy->castAs<FunctionType>();
1142 }
1143
1144 if (const FunctionProtoType *FPT =
1145 dyn_cast_or_null<FunctionProtoType>(FunTy)) {
1146 if (FPT->getNumArgs() == 0)
1147 ZeroArgCallReturnTy = FunTy->getResultType();
1148 return true;
1149 }
1150 return false;
1151 }
1152
1153 /// \brief Give notes for a set of overloads.
1154 ///
1155 /// A companion to isExprCallable. In cases when the name that the programmer
1156 /// wrote was an overloaded function, we may be able to make some guesses about
1157 /// plausible overloads based on their return types; such guesses can be handed
1158 /// off to this method to be emitted as notes.
1159 ///
1160 /// \param Overloads - The overloads to note.
1161 /// \param FinalNoteLoc - If we've suppressed printing some overloads due to
1162 /// -fshow-overloads=best, this is the location to attach to the note about too
1163 /// many candidates. Typically this will be the location of the original
1164 /// ill-formed expression.
noteOverloads(Sema & S,const UnresolvedSetImpl & Overloads,const SourceLocation FinalNoteLoc)1165 static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
1166 const SourceLocation FinalNoteLoc) {
1167 int ShownOverloads = 0;
1168 int SuppressedOverloads = 0;
1169 for (UnresolvedSetImpl::iterator It = Overloads.begin(),
1170 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1171 // FIXME: Magic number for max shown overloads stolen from
1172 // OverloadCandidateSet::NoteCandidates.
1173 if (ShownOverloads >= 4 &&
1174 S.Diags.getShowOverloads() == DiagnosticsEngine::Ovl_Best) {
1175 ++SuppressedOverloads;
1176 continue;
1177 }
1178
1179 NamedDecl *Fn = (*It)->getUnderlyingDecl();
1180 S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
1181 ++ShownOverloads;
1182 }
1183
1184 if (SuppressedOverloads)
1185 S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
1186 << SuppressedOverloads;
1187 }
1188
notePlausibleOverloads(Sema & S,SourceLocation Loc,const UnresolvedSetImpl & Overloads,bool (* IsPlausibleResult)(QualType))1189 static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
1190 const UnresolvedSetImpl &Overloads,
1191 bool (*IsPlausibleResult)(QualType)) {
1192 if (!IsPlausibleResult)
1193 return noteOverloads(S, Overloads, Loc);
1194
1195 UnresolvedSet<2> PlausibleOverloads;
1196 for (OverloadExpr::decls_iterator It = Overloads.begin(),
1197 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1198 const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
1199 QualType OverloadResultTy = OverloadDecl->getResultType();
1200 if (IsPlausibleResult(OverloadResultTy))
1201 PlausibleOverloads.addDecl(It.getDecl());
1202 }
1203 noteOverloads(S, PlausibleOverloads, Loc);
1204 }
1205
1206 /// Determine whether the given expression can be called by just
1207 /// putting parentheses after it. Notably, expressions with unary
1208 /// operators can't be because the unary operator will start parsing
1209 /// outside the call.
IsCallableWithAppend(Expr * E)1210 static bool IsCallableWithAppend(Expr *E) {
1211 E = E->IgnoreImplicit();
1212 return (!isa<CStyleCastExpr>(E) &&
1213 !isa<UnaryOperator>(E) &&
1214 !isa<BinaryOperator>(E) &&
1215 !isa<CXXOperatorCallExpr>(E));
1216 }
1217
tryToRecoverWithCall(ExprResult & E,const PartialDiagnostic & PD,bool ForceComplain,bool (* IsPlausibleResult)(QualType))1218 bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
1219 bool ForceComplain,
1220 bool (*IsPlausibleResult)(QualType)) {
1221 SourceLocation Loc = E.get()->getExprLoc();
1222 SourceRange Range = E.get()->getSourceRange();
1223
1224 QualType ZeroArgCallTy;
1225 UnresolvedSet<4> Overloads;
1226 if (isExprCallable(*E.get(), ZeroArgCallTy, Overloads) &&
1227 !ZeroArgCallTy.isNull() &&
1228 (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) {
1229 // At this point, we know E is potentially callable with 0
1230 // arguments and that it returns something of a reasonable type,
1231 // so we can emit a fixit and carry on pretending that E was
1232 // actually a CallExpr.
1233 SourceLocation ParenInsertionLoc =
1234 PP.getLocForEndOfToken(Range.getEnd());
1235 Diag(Loc, PD)
1236 << /*zero-arg*/ 1 << Range
1237 << (IsCallableWithAppend(E.get())
1238 ? FixItHint::CreateInsertion(ParenInsertionLoc, "()")
1239 : FixItHint());
1240 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
1241
1242 // FIXME: Try this before emitting the fixit, and suppress diagnostics
1243 // while doing so.
1244 E = ActOnCallExpr(0, E.take(), ParenInsertionLoc,
1245 MultiExprArg(), ParenInsertionLoc.getLocWithOffset(1));
1246 return true;
1247 }
1248
1249 if (!ForceComplain) return false;
1250
1251 Diag(Loc, PD) << /*not zero-arg*/ 0 << Range;
1252 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
1253 E = ExprError();
1254 return true;
1255 }
1256