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1 //===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
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 Objective-C expressions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Sema/SemaInternal.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/ExprObjC.h"
18 #include "clang/AST/StmtVisitor.h"
19 #include "clang/AST/TypeLoc.h"
20 #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
21 #include "clang/Edit/Commit.h"
22 #include "clang/Edit/Rewriters.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Sema/Initialization.h"
25 #include "clang/Sema/Lookup.h"
26 #include "clang/Sema/Scope.h"
27 #include "clang/Sema/ScopeInfo.h"
28 #include "llvm/ADT/SmallString.h"
29 
30 using namespace clang;
31 using namespace sema;
32 using llvm::makeArrayRef;
33 
ParseObjCStringLiteral(SourceLocation * AtLocs,Expr ** strings,unsigned NumStrings)34 ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
35                                         Expr **strings,
36                                         unsigned NumStrings) {
37   StringLiteral **Strings = reinterpret_cast<StringLiteral**>(strings);
38 
39   // Most ObjC strings are formed out of a single piece.  However, we *can*
40   // have strings formed out of multiple @ strings with multiple pptokens in
41   // each one, e.g. @"foo" "bar" @"baz" "qux"   which need to be turned into one
42   // StringLiteral for ObjCStringLiteral to hold onto.
43   StringLiteral *S = Strings[0];
44 
45   // If we have a multi-part string, merge it all together.
46   if (NumStrings != 1) {
47     // Concatenate objc strings.
48     SmallString<128> StrBuf;
49     SmallVector<SourceLocation, 8> StrLocs;
50 
51     for (unsigned i = 0; i != NumStrings; ++i) {
52       S = Strings[i];
53 
54       // ObjC strings can't be wide or UTF.
55       if (!S->isAscii()) {
56         Diag(S->getLocStart(), diag::err_cfstring_literal_not_string_constant)
57           << S->getSourceRange();
58         return true;
59       }
60 
61       // Append the string.
62       StrBuf += S->getString();
63 
64       // Get the locations of the string tokens.
65       StrLocs.append(S->tokloc_begin(), S->tokloc_end());
66     }
67 
68     // Create the aggregate string with the appropriate content and location
69     // information.
70     S = StringLiteral::Create(Context, StrBuf,
71                               StringLiteral::Ascii, /*Pascal=*/false,
72                               Context.getPointerType(Context.CharTy),
73                               &StrLocs[0], StrLocs.size());
74   }
75 
76   return BuildObjCStringLiteral(AtLocs[0], S);
77 }
78 
BuildObjCStringLiteral(SourceLocation AtLoc,StringLiteral * S)79 ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
80   // Verify that this composite string is acceptable for ObjC strings.
81   if (CheckObjCString(S))
82     return true;
83 
84   // Initialize the constant string interface lazily. This assumes
85   // the NSString interface is seen in this translation unit. Note: We
86   // don't use NSConstantString, since the runtime team considers this
87   // interface private (even though it appears in the header files).
88   QualType Ty = Context.getObjCConstantStringInterface();
89   if (!Ty.isNull()) {
90     Ty = Context.getObjCObjectPointerType(Ty);
91   } else if (getLangOpts().NoConstantCFStrings) {
92     IdentifierInfo *NSIdent=0;
93     std::string StringClass(getLangOpts().ObjCConstantStringClass);
94 
95     if (StringClass.empty())
96       NSIdent = &Context.Idents.get("NSConstantString");
97     else
98       NSIdent = &Context.Idents.get(StringClass);
99 
100     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
101                                      LookupOrdinaryName);
102     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
103       Context.setObjCConstantStringInterface(StrIF);
104       Ty = Context.getObjCConstantStringInterface();
105       Ty = Context.getObjCObjectPointerType(Ty);
106     } else {
107       // If there is no NSConstantString interface defined then treat this
108       // as error and recover from it.
109       Diag(S->getLocStart(), diag::err_no_nsconstant_string_class) << NSIdent
110         << S->getSourceRange();
111       Ty = Context.getObjCIdType();
112     }
113   } else {
114     IdentifierInfo *NSIdent = NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
115     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
116                                      LookupOrdinaryName);
117     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
118       Context.setObjCConstantStringInterface(StrIF);
119       Ty = Context.getObjCConstantStringInterface();
120       Ty = Context.getObjCObjectPointerType(Ty);
121     } else {
122       // If there is no NSString interface defined, implicitly declare
123       // a @class NSString; and use that instead. This is to make sure
124       // type of an NSString literal is represented correctly, instead of
125       // being an 'id' type.
126       Ty = Context.getObjCNSStringType();
127       if (Ty.isNull()) {
128         ObjCInterfaceDecl *NSStringIDecl =
129           ObjCInterfaceDecl::Create (Context,
130                                      Context.getTranslationUnitDecl(),
131                                      SourceLocation(), NSIdent,
132                                      0, SourceLocation());
133         Ty = Context.getObjCInterfaceType(NSStringIDecl);
134         Context.setObjCNSStringType(Ty);
135       }
136       Ty = Context.getObjCObjectPointerType(Ty);
137     }
138   }
139 
140   return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
141 }
142 
143 /// \brief Emits an error if the given method does not exist, or if the return
144 /// type is not an Objective-C object.
validateBoxingMethod(Sema & S,SourceLocation Loc,const ObjCInterfaceDecl * Class,Selector Sel,const ObjCMethodDecl * Method)145 static bool validateBoxingMethod(Sema &S, SourceLocation Loc,
146                                  const ObjCInterfaceDecl *Class,
147                                  Selector Sel, const ObjCMethodDecl *Method) {
148   if (!Method) {
149     // FIXME: Is there a better way to avoid quotes than using getName()?
150     S.Diag(Loc, diag::err_undeclared_boxing_method) << Sel << Class->getName();
151     return false;
152   }
153 
154   // Make sure the return type is reasonable.
155   QualType ReturnType = Method->getResultType();
156   if (!ReturnType->isObjCObjectPointerType()) {
157     S.Diag(Loc, diag::err_objc_literal_method_sig)
158       << Sel;
159     S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
160       << ReturnType;
161     return false;
162   }
163 
164   return true;
165 }
166 
167 /// \brief Retrieve the NSNumber factory method that should be used to create
168 /// an Objective-C literal for the given type.
getNSNumberFactoryMethod(Sema & S,SourceLocation Loc,QualType NumberType,bool isLiteral=false,SourceRange R=SourceRange ())169 static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
170                                                 QualType NumberType,
171                                                 bool isLiteral = false,
172                                                 SourceRange R = SourceRange()) {
173   Optional<NSAPI::NSNumberLiteralMethodKind> Kind =
174       S.NSAPIObj->getNSNumberFactoryMethodKind(NumberType);
175 
176   if (!Kind) {
177     if (isLiteral) {
178       S.Diag(Loc, diag::err_invalid_nsnumber_type)
179         << NumberType << R;
180     }
181     return 0;
182   }
183 
184   // If we already looked up this method, we're done.
185   if (S.NSNumberLiteralMethods[*Kind])
186     return S.NSNumberLiteralMethods[*Kind];
187 
188   Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
189                                                         /*Instance=*/false);
190 
191   ASTContext &CX = S.Context;
192 
193   // Look up the NSNumber class, if we haven't done so already. It's cached
194   // in the Sema instance.
195   if (!S.NSNumberDecl) {
196     IdentifierInfo *NSNumberId =
197       S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSNumber);
198     NamedDecl *IF = S.LookupSingleName(S.TUScope, NSNumberId,
199                                        Loc, Sema::LookupOrdinaryName);
200     S.NSNumberDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
201     if (!S.NSNumberDecl) {
202       if (S.getLangOpts().DebuggerObjCLiteral) {
203         // Create a stub definition of NSNumber.
204         S.NSNumberDecl = ObjCInterfaceDecl::Create(CX,
205                                                    CX.getTranslationUnitDecl(),
206                                                    SourceLocation(), NSNumberId,
207                                                    0, SourceLocation());
208       } else {
209         // Otherwise, require a declaration of NSNumber.
210         S.Diag(Loc, diag::err_undeclared_nsnumber);
211         return 0;
212       }
213     } else if (!S.NSNumberDecl->hasDefinition()) {
214       S.Diag(Loc, diag::err_undeclared_nsnumber);
215       return 0;
216     }
217 
218     // generate the pointer to NSNumber type.
219     QualType NSNumberObject = CX.getObjCInterfaceType(S.NSNumberDecl);
220     S.NSNumberPointer = CX.getObjCObjectPointerType(NSNumberObject);
221   }
222 
223   // Look for the appropriate method within NSNumber.
224   ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);
225   if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
226     // create a stub definition this NSNumber factory method.
227     TypeSourceInfo *ResultTInfo = 0;
228     Method = ObjCMethodDecl::Create(CX, SourceLocation(), SourceLocation(), Sel,
229                                     S.NSNumberPointer, ResultTInfo,
230                                     S.NSNumberDecl,
231                                     /*isInstance=*/false, /*isVariadic=*/false,
232                                     /*isPropertyAccessor=*/false,
233                                     /*isImplicitlyDeclared=*/true,
234                                     /*isDefined=*/false,
235                                     ObjCMethodDecl::Required,
236                                     /*HasRelatedResultType=*/false);
237     ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
238                                              SourceLocation(), SourceLocation(),
239                                              &CX.Idents.get("value"),
240                                              NumberType, /*TInfo=*/0, SC_None,
241                                              0);
242     Method->setMethodParams(S.Context, value, None);
243   }
244 
245   if (!validateBoxingMethod(S, Loc, S.NSNumberDecl, Sel, Method))
246     return 0;
247 
248   // Note: if the parameter type is out-of-line, we'll catch it later in the
249   // implicit conversion.
250 
251   S.NSNumberLiteralMethods[*Kind] = Method;
252   return Method;
253 }
254 
255 /// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
256 /// numeric literal expression. Type of the expression will be "NSNumber *".
BuildObjCNumericLiteral(SourceLocation AtLoc,Expr * Number)257 ExprResult Sema::BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number) {
258   // Determine the type of the literal.
259   QualType NumberType = Number->getType();
260   if (CharacterLiteral *Char = dyn_cast<CharacterLiteral>(Number)) {
261     // In C, character literals have type 'int'. That's not the type we want
262     // to use to determine the Objective-c literal kind.
263     switch (Char->getKind()) {
264     case CharacterLiteral::Ascii:
265       NumberType = Context.CharTy;
266       break;
267 
268     case CharacterLiteral::Wide:
269       NumberType = Context.getWideCharType();
270       break;
271 
272     case CharacterLiteral::UTF16:
273       NumberType = Context.Char16Ty;
274       break;
275 
276     case CharacterLiteral::UTF32:
277       NumberType = Context.Char32Ty;
278       break;
279     }
280   }
281 
282   // Look for the appropriate method within NSNumber.
283   // Construct the literal.
284   SourceRange NR(Number->getSourceRange());
285   ObjCMethodDecl *Method = getNSNumberFactoryMethod(*this, AtLoc, NumberType,
286                                                     true, NR);
287   if (!Method)
288     return ExprError();
289 
290   // Convert the number to the type that the parameter expects.
291   ParmVarDecl *ParamDecl = Method->param_begin()[0];
292   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
293                                                                     ParamDecl);
294   ExprResult ConvertedNumber = PerformCopyInitialization(Entity,
295                                                          SourceLocation(),
296                                                          Owned(Number));
297   if (ConvertedNumber.isInvalid())
298     return ExprError();
299   Number = ConvertedNumber.get();
300 
301   // Use the effective source range of the literal, including the leading '@'.
302   return MaybeBindToTemporary(
303            new (Context) ObjCBoxedExpr(Number, NSNumberPointer, Method,
304                                        SourceRange(AtLoc, NR.getEnd())));
305 }
306 
ActOnObjCBoolLiteral(SourceLocation AtLoc,SourceLocation ValueLoc,bool Value)307 ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation AtLoc,
308                                       SourceLocation ValueLoc,
309                                       bool Value) {
310   ExprResult Inner;
311   if (getLangOpts().CPlusPlus) {
312     Inner = ActOnCXXBoolLiteral(ValueLoc, Value? tok::kw_true : tok::kw_false);
313   } else {
314     // C doesn't actually have a way to represent literal values of type
315     // _Bool. So, we'll use 0/1 and implicit cast to _Bool.
316     Inner = ActOnIntegerConstant(ValueLoc, Value? 1 : 0);
317     Inner = ImpCastExprToType(Inner.get(), Context.BoolTy,
318                               CK_IntegralToBoolean);
319   }
320 
321   return BuildObjCNumericLiteral(AtLoc, Inner.get());
322 }
323 
324 /// \brief Check that the given expression is a valid element of an Objective-C
325 /// collection literal.
CheckObjCCollectionLiteralElement(Sema & S,Expr * Element,QualType T)326 static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element,
327                                                     QualType T) {
328   // If the expression is type-dependent, there's nothing for us to do.
329   if (Element->isTypeDependent())
330     return Element;
331 
332   ExprResult Result = S.CheckPlaceholderExpr(Element);
333   if (Result.isInvalid())
334     return ExprError();
335   Element = Result.get();
336 
337   // In C++, check for an implicit conversion to an Objective-C object pointer
338   // type.
339   if (S.getLangOpts().CPlusPlus && Element->getType()->isRecordType()) {
340     InitializedEntity Entity
341       = InitializedEntity::InitializeParameter(S.Context, T,
342                                                /*Consumed=*/false);
343     InitializationKind Kind
344       = InitializationKind::CreateCopy(Element->getLocStart(),
345                                        SourceLocation());
346     InitializationSequence Seq(S, Entity, Kind, Element);
347     if (!Seq.Failed())
348       return Seq.Perform(S, Entity, Kind, Element);
349   }
350 
351   Expr *OrigElement = Element;
352 
353   // Perform lvalue-to-rvalue conversion.
354   Result = S.DefaultLvalueConversion(Element);
355   if (Result.isInvalid())
356     return ExprError();
357   Element = Result.get();
358 
359   // Make sure that we have an Objective-C pointer type or block.
360   if (!Element->getType()->isObjCObjectPointerType() &&
361       !Element->getType()->isBlockPointerType()) {
362     bool Recovered = false;
363 
364     // If this is potentially an Objective-C numeric literal, add the '@'.
365     if (isa<IntegerLiteral>(OrigElement) ||
366         isa<CharacterLiteral>(OrigElement) ||
367         isa<FloatingLiteral>(OrigElement) ||
368         isa<ObjCBoolLiteralExpr>(OrigElement) ||
369         isa<CXXBoolLiteralExpr>(OrigElement)) {
370       if (S.NSAPIObj->getNSNumberFactoryMethodKind(OrigElement->getType())) {
371         int Which = isa<CharacterLiteral>(OrigElement) ? 1
372                   : (isa<CXXBoolLiteralExpr>(OrigElement) ||
373                      isa<ObjCBoolLiteralExpr>(OrigElement)) ? 2
374                   : 3;
375 
376         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
377           << Which << OrigElement->getSourceRange()
378           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
379 
380         Result = S.BuildObjCNumericLiteral(OrigElement->getLocStart(),
381                                            OrigElement);
382         if (Result.isInvalid())
383           return ExprError();
384 
385         Element = Result.get();
386         Recovered = true;
387       }
388     }
389     // If this is potentially an Objective-C string literal, add the '@'.
390     else if (StringLiteral *String = dyn_cast<StringLiteral>(OrigElement)) {
391       if (String->isAscii()) {
392         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
393           << 0 << OrigElement->getSourceRange()
394           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
395 
396         Result = S.BuildObjCStringLiteral(OrigElement->getLocStart(), String);
397         if (Result.isInvalid())
398           return ExprError();
399 
400         Element = Result.get();
401         Recovered = true;
402       }
403     }
404 
405     if (!Recovered) {
406       S.Diag(Element->getLocStart(), diag::err_invalid_collection_element)
407         << Element->getType();
408       return ExprError();
409     }
410   }
411 
412   // Make sure that the element has the type that the container factory
413   // function expects.
414   return S.PerformCopyInitialization(
415            InitializedEntity::InitializeParameter(S.Context, T,
416                                                   /*Consumed=*/false),
417            Element->getLocStart(), Element);
418 }
419 
BuildObjCBoxedExpr(SourceRange SR,Expr * ValueExpr)420 ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
421   if (ValueExpr->isTypeDependent()) {
422     ObjCBoxedExpr *BoxedExpr =
423       new (Context) ObjCBoxedExpr(ValueExpr, Context.DependentTy, NULL, SR);
424     return Owned(BoxedExpr);
425   }
426   ObjCMethodDecl *BoxingMethod = NULL;
427   QualType BoxedType;
428   // Convert the expression to an RValue, so we can check for pointer types...
429   ExprResult RValue = DefaultFunctionArrayLvalueConversion(ValueExpr);
430   if (RValue.isInvalid()) {
431     return ExprError();
432   }
433   ValueExpr = RValue.get();
434   QualType ValueType(ValueExpr->getType());
435   if (const PointerType *PT = ValueType->getAs<PointerType>()) {
436     QualType PointeeType = PT->getPointeeType();
437     if (Context.hasSameUnqualifiedType(PointeeType, Context.CharTy)) {
438 
439       if (!NSStringDecl) {
440         IdentifierInfo *NSStringId =
441           NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
442         NamedDecl *Decl = LookupSingleName(TUScope, NSStringId,
443                                            SR.getBegin(), LookupOrdinaryName);
444         NSStringDecl = dyn_cast_or_null<ObjCInterfaceDecl>(Decl);
445         if (!NSStringDecl) {
446           if (getLangOpts().DebuggerObjCLiteral) {
447             // Support boxed expressions in the debugger w/o NSString declaration.
448             DeclContext *TU = Context.getTranslationUnitDecl();
449             NSStringDecl = ObjCInterfaceDecl::Create(Context, TU,
450                                                      SourceLocation(),
451                                                      NSStringId,
452                                                      0, SourceLocation());
453           } else {
454             Diag(SR.getBegin(), diag::err_undeclared_nsstring);
455             return ExprError();
456           }
457         } else if (!NSStringDecl->hasDefinition()) {
458           Diag(SR.getBegin(), diag::err_undeclared_nsstring);
459           return ExprError();
460         }
461         assert(NSStringDecl && "NSStringDecl should not be NULL");
462         QualType NSStringObject = Context.getObjCInterfaceType(NSStringDecl);
463         NSStringPointer = Context.getObjCObjectPointerType(NSStringObject);
464       }
465 
466       if (!StringWithUTF8StringMethod) {
467         IdentifierInfo *II = &Context.Idents.get("stringWithUTF8String");
468         Selector stringWithUTF8String = Context.Selectors.getUnarySelector(II);
469 
470         // Look for the appropriate method within NSString.
471         BoxingMethod = NSStringDecl->lookupClassMethod(stringWithUTF8String);
472         if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
473           // Debugger needs to work even if NSString hasn't been defined.
474           TypeSourceInfo *ResultTInfo = 0;
475           ObjCMethodDecl *M =
476             ObjCMethodDecl::Create(Context, SourceLocation(), SourceLocation(),
477                                    stringWithUTF8String, NSStringPointer,
478                                    ResultTInfo, NSStringDecl,
479                                    /*isInstance=*/false, /*isVariadic=*/false,
480                                    /*isPropertyAccessor=*/false,
481                                    /*isImplicitlyDeclared=*/true,
482                                    /*isDefined=*/false,
483                                    ObjCMethodDecl::Required,
484                                    /*HasRelatedResultType=*/false);
485           QualType ConstCharType = Context.CharTy.withConst();
486           ParmVarDecl *value =
487             ParmVarDecl::Create(Context, M,
488                                 SourceLocation(), SourceLocation(),
489                                 &Context.Idents.get("value"),
490                                 Context.getPointerType(ConstCharType),
491                                 /*TInfo=*/0,
492                                 SC_None, 0);
493           M->setMethodParams(Context, value, None);
494           BoxingMethod = M;
495         }
496 
497         if (!validateBoxingMethod(*this, SR.getBegin(), NSStringDecl,
498                                   stringWithUTF8String, BoxingMethod))
499            return ExprError();
500 
501         StringWithUTF8StringMethod = BoxingMethod;
502       }
503 
504       BoxingMethod = StringWithUTF8StringMethod;
505       BoxedType = NSStringPointer;
506     }
507   } else if (ValueType->isBuiltinType()) {
508     // The other types we support are numeric, char and BOOL/bool. We could also
509     // provide limited support for structure types, such as NSRange, NSRect, and
510     // NSSize. See NSValue (NSValueGeometryExtensions) in <Foundation/NSGeometry.h>
511     // for more details.
512 
513     // Check for a top-level character literal.
514     if (const CharacterLiteral *Char =
515         dyn_cast<CharacterLiteral>(ValueExpr->IgnoreParens())) {
516       // In C, character literals have type 'int'. That's not the type we want
517       // to use to determine the Objective-c literal kind.
518       switch (Char->getKind()) {
519       case CharacterLiteral::Ascii:
520         ValueType = Context.CharTy;
521         break;
522 
523       case CharacterLiteral::Wide:
524         ValueType = Context.getWideCharType();
525         break;
526 
527       case CharacterLiteral::UTF16:
528         ValueType = Context.Char16Ty;
529         break;
530 
531       case CharacterLiteral::UTF32:
532         ValueType = Context.Char32Ty;
533         break;
534       }
535     }
536 
537     // FIXME:  Do I need to do anything special with BoolTy expressions?
538 
539     // Look for the appropriate method within NSNumber.
540     BoxingMethod = getNSNumberFactoryMethod(*this, SR.getBegin(), ValueType);
541     BoxedType = NSNumberPointer;
542 
543   } else if (const EnumType *ET = ValueType->getAs<EnumType>()) {
544     if (!ET->getDecl()->isComplete()) {
545       Diag(SR.getBegin(), diag::err_objc_incomplete_boxed_expression_type)
546         << ValueType << ValueExpr->getSourceRange();
547       return ExprError();
548     }
549 
550     BoxingMethod = getNSNumberFactoryMethod(*this, SR.getBegin(),
551                                             ET->getDecl()->getIntegerType());
552     BoxedType = NSNumberPointer;
553   }
554 
555   if (!BoxingMethod) {
556     Diag(SR.getBegin(), diag::err_objc_illegal_boxed_expression_type)
557       << ValueType << ValueExpr->getSourceRange();
558     return ExprError();
559   }
560 
561   // Convert the expression to the type that the parameter requires.
562   ParmVarDecl *ParamDecl = BoxingMethod->param_begin()[0];
563   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
564                                                                     ParamDecl);
565   ExprResult ConvertedValueExpr = PerformCopyInitialization(Entity,
566                                                             SourceLocation(),
567                                                             Owned(ValueExpr));
568   if (ConvertedValueExpr.isInvalid())
569     return ExprError();
570   ValueExpr = ConvertedValueExpr.get();
571 
572   ObjCBoxedExpr *BoxedExpr =
573     new (Context) ObjCBoxedExpr(ValueExpr, BoxedType,
574                                       BoxingMethod, SR);
575   return MaybeBindToTemporary(BoxedExpr);
576 }
577 
578 /// Build an ObjC subscript pseudo-object expression, given that
579 /// that's supported by the runtime.
BuildObjCSubscriptExpression(SourceLocation RB,Expr * BaseExpr,Expr * IndexExpr,ObjCMethodDecl * getterMethod,ObjCMethodDecl * setterMethod)580 ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
581                                         Expr *IndexExpr,
582                                         ObjCMethodDecl *getterMethod,
583                                         ObjCMethodDecl *setterMethod) {
584   assert(!LangOpts.ObjCRuntime.isSubscriptPointerArithmetic());
585 
586   // We can't get dependent types here; our callers should have
587   // filtered them out.
588   assert((!BaseExpr->isTypeDependent() && !IndexExpr->isTypeDependent()) &&
589          "base or index cannot have dependent type here");
590 
591   // Filter out placeholders in the index.  In theory, overloads could
592   // be preserved here, although that might not actually work correctly.
593   ExprResult Result = CheckPlaceholderExpr(IndexExpr);
594   if (Result.isInvalid())
595     return ExprError();
596   IndexExpr = Result.get();
597 
598   // Perform lvalue-to-rvalue conversion on the base.
599   Result = DefaultLvalueConversion(BaseExpr);
600   if (Result.isInvalid())
601     return ExprError();
602   BaseExpr = Result.get();
603 
604   // Build the pseudo-object expression.
605   return Owned(ObjCSubscriptRefExpr::Create(Context,
606                                             BaseExpr,
607                                             IndexExpr,
608                                             Context.PseudoObjectTy,
609                                             getterMethod,
610                                             setterMethod, RB));
611 
612 }
613 
BuildObjCArrayLiteral(SourceRange SR,MultiExprArg Elements)614 ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
615   // Look up the NSArray class, if we haven't done so already.
616   if (!NSArrayDecl) {
617     NamedDecl *IF = LookupSingleName(TUScope,
618                                  NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
619                                  SR.getBegin(),
620                                  LookupOrdinaryName);
621     NSArrayDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
622     if (!NSArrayDecl && getLangOpts().DebuggerObjCLiteral)
623       NSArrayDecl =  ObjCInterfaceDecl::Create (Context,
624                             Context.getTranslationUnitDecl(),
625                             SourceLocation(),
626                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
627                             0, SourceLocation());
628 
629     if (!NSArrayDecl) {
630       Diag(SR.getBegin(), diag::err_undeclared_nsarray);
631       return ExprError();
632     }
633   }
634 
635   // Find the arrayWithObjects:count: method, if we haven't done so already.
636   QualType IdT = Context.getObjCIdType();
637   if (!ArrayWithObjectsMethod) {
638     Selector
639       Sel = NSAPIObj->getNSArraySelector(NSAPI::NSArr_arrayWithObjectsCount);
640     ObjCMethodDecl *Method = NSArrayDecl->lookupClassMethod(Sel);
641     if (!Method && getLangOpts().DebuggerObjCLiteral) {
642       TypeSourceInfo *ResultTInfo = 0;
643       Method = ObjCMethodDecl::Create(Context,
644                            SourceLocation(), SourceLocation(), Sel,
645                            IdT,
646                            ResultTInfo,
647                            Context.getTranslationUnitDecl(),
648                            false /*Instance*/, false/*isVariadic*/,
649                            /*isPropertyAccessor=*/false,
650                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
651                            ObjCMethodDecl::Required,
652                            false);
653       SmallVector<ParmVarDecl *, 2> Params;
654       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
655                                                  SourceLocation(),
656                                                  SourceLocation(),
657                                                  &Context.Idents.get("objects"),
658                                                  Context.getPointerType(IdT),
659                                                  /*TInfo=*/0, SC_None, 0);
660       Params.push_back(objects);
661       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
662                                              SourceLocation(),
663                                              SourceLocation(),
664                                              &Context.Idents.get("cnt"),
665                                              Context.UnsignedLongTy,
666                                              /*TInfo=*/0, SC_None, 0);
667       Params.push_back(cnt);
668       Method->setMethodParams(Context, Params, None);
669     }
670 
671     if (!validateBoxingMethod(*this, SR.getBegin(), NSArrayDecl, Sel, Method))
672       return ExprError();
673 
674     // Dig out the type that all elements should be converted to.
675     QualType T = Method->param_begin()[0]->getType();
676     const PointerType *PtrT = T->getAs<PointerType>();
677     if (!PtrT ||
678         !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
679       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
680         << Sel;
681       Diag(Method->param_begin()[0]->getLocation(),
682            diag::note_objc_literal_method_param)
683         << 0 << T
684         << Context.getPointerType(IdT.withConst());
685       return ExprError();
686     }
687 
688     // Check that the 'count' parameter is integral.
689     if (!Method->param_begin()[1]->getType()->isIntegerType()) {
690       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
691         << Sel;
692       Diag(Method->param_begin()[1]->getLocation(),
693            diag::note_objc_literal_method_param)
694         << 1
695         << Method->param_begin()[1]->getType()
696         << "integral";
697       return ExprError();
698     }
699 
700     // We've found a good +arrayWithObjects:count: method. Save it!
701     ArrayWithObjectsMethod = Method;
702   }
703 
704   QualType ObjectsType = ArrayWithObjectsMethod->param_begin()[0]->getType();
705   QualType RequiredType = ObjectsType->castAs<PointerType>()->getPointeeType();
706 
707   // Check that each of the elements provided is valid in a collection literal,
708   // performing conversions as necessary.
709   Expr **ElementsBuffer = Elements.data();
710   for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
711     ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
712                                                              ElementsBuffer[I],
713                                                              RequiredType);
714     if (Converted.isInvalid())
715       return ExprError();
716 
717     ElementsBuffer[I] = Converted.get();
718   }
719 
720   QualType Ty
721     = Context.getObjCObjectPointerType(
722                                     Context.getObjCInterfaceType(NSArrayDecl));
723 
724   return MaybeBindToTemporary(
725            ObjCArrayLiteral::Create(Context, Elements, Ty,
726                                     ArrayWithObjectsMethod, SR));
727 }
728 
BuildObjCDictionaryLiteral(SourceRange SR,ObjCDictionaryElement * Elements,unsigned NumElements)729 ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
730                                             ObjCDictionaryElement *Elements,
731                                             unsigned NumElements) {
732   // Look up the NSDictionary class, if we haven't done so already.
733   if (!NSDictionaryDecl) {
734     NamedDecl *IF = LookupSingleName(TUScope,
735                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
736                             SR.getBegin(), LookupOrdinaryName);
737     NSDictionaryDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
738     if (!NSDictionaryDecl && getLangOpts().DebuggerObjCLiteral)
739       NSDictionaryDecl =  ObjCInterfaceDecl::Create (Context,
740                             Context.getTranslationUnitDecl(),
741                             SourceLocation(),
742                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
743                             0, SourceLocation());
744 
745     if (!NSDictionaryDecl) {
746       Diag(SR.getBegin(), diag::err_undeclared_nsdictionary);
747       return ExprError();
748     }
749   }
750 
751   // Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
752   // so already.
753   QualType IdT = Context.getObjCIdType();
754   if (!DictionaryWithObjectsMethod) {
755     Selector Sel = NSAPIObj->getNSDictionarySelector(
756                                NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
757     ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
758     if (!Method && getLangOpts().DebuggerObjCLiteral) {
759       Method = ObjCMethodDecl::Create(Context,
760                            SourceLocation(), SourceLocation(), Sel,
761                            IdT,
762                            0 /*TypeSourceInfo */,
763                            Context.getTranslationUnitDecl(),
764                            false /*Instance*/, false/*isVariadic*/,
765                            /*isPropertyAccessor=*/false,
766                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
767                            ObjCMethodDecl::Required,
768                            false);
769       SmallVector<ParmVarDecl *, 3> Params;
770       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
771                                                  SourceLocation(),
772                                                  SourceLocation(),
773                                                  &Context.Idents.get("objects"),
774                                                  Context.getPointerType(IdT),
775                                                  /*TInfo=*/0, SC_None, 0);
776       Params.push_back(objects);
777       ParmVarDecl *keys = ParmVarDecl::Create(Context, Method,
778                                               SourceLocation(),
779                                               SourceLocation(),
780                                               &Context.Idents.get("keys"),
781                                               Context.getPointerType(IdT),
782                                               /*TInfo=*/0, SC_None, 0);
783       Params.push_back(keys);
784       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
785                                              SourceLocation(),
786                                              SourceLocation(),
787                                              &Context.Idents.get("cnt"),
788                                              Context.UnsignedLongTy,
789                                              /*TInfo=*/0, SC_None, 0);
790       Params.push_back(cnt);
791       Method->setMethodParams(Context, Params, None);
792     }
793 
794     if (!validateBoxingMethod(*this, SR.getBegin(), NSDictionaryDecl, Sel,
795                               Method))
796        return ExprError();
797 
798     // Dig out the type that all values should be converted to.
799     QualType ValueT = Method->param_begin()[0]->getType();
800     const PointerType *PtrValue = ValueT->getAs<PointerType>();
801     if (!PtrValue ||
802         !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
803       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
804         << Sel;
805       Diag(Method->param_begin()[0]->getLocation(),
806            diag::note_objc_literal_method_param)
807         << 0 << ValueT
808         << Context.getPointerType(IdT.withConst());
809       return ExprError();
810     }
811 
812     // Dig out the type that all keys should be converted to.
813     QualType KeyT = Method->param_begin()[1]->getType();
814     const PointerType *PtrKey = KeyT->getAs<PointerType>();
815     if (!PtrKey ||
816         !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
817                                         IdT)) {
818       bool err = true;
819       if (PtrKey) {
820         if (QIDNSCopying.isNull()) {
821           // key argument of selector is id<NSCopying>?
822           if (ObjCProtocolDecl *NSCopyingPDecl =
823               LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
824             ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
825             QIDNSCopying =
826               Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
827                                         (ObjCProtocolDecl**) PQ,1);
828             QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
829           }
830         }
831         if (!QIDNSCopying.isNull())
832           err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
833                                                 QIDNSCopying);
834       }
835 
836       if (err) {
837         Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
838           << Sel;
839         Diag(Method->param_begin()[1]->getLocation(),
840              diag::note_objc_literal_method_param)
841           << 1 << KeyT
842           << Context.getPointerType(IdT.withConst());
843         return ExprError();
844       }
845     }
846 
847     // Check that the 'count' parameter is integral.
848     QualType CountType = Method->param_begin()[2]->getType();
849     if (!CountType->isIntegerType()) {
850       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
851         << Sel;
852       Diag(Method->param_begin()[2]->getLocation(),
853            diag::note_objc_literal_method_param)
854         << 2 << CountType
855         << "integral";
856       return ExprError();
857     }
858 
859     // We've found a good +dictionaryWithObjects:keys:count: method; save it!
860     DictionaryWithObjectsMethod = Method;
861   }
862 
863   QualType ValuesT = DictionaryWithObjectsMethod->param_begin()[0]->getType();
864   QualType ValueT = ValuesT->castAs<PointerType>()->getPointeeType();
865   QualType KeysT = DictionaryWithObjectsMethod->param_begin()[1]->getType();
866   QualType KeyT = KeysT->castAs<PointerType>()->getPointeeType();
867 
868   // Check that each of the keys and values provided is valid in a collection
869   // literal, performing conversions as necessary.
870   bool HasPackExpansions = false;
871   for (unsigned I = 0, N = NumElements; I != N; ++I) {
872     // Check the key.
873     ExprResult Key = CheckObjCCollectionLiteralElement(*this, Elements[I].Key,
874                                                        KeyT);
875     if (Key.isInvalid())
876       return ExprError();
877 
878     // Check the value.
879     ExprResult Value
880       = CheckObjCCollectionLiteralElement(*this, Elements[I].Value, ValueT);
881     if (Value.isInvalid())
882       return ExprError();
883 
884     Elements[I].Key = Key.get();
885     Elements[I].Value = Value.get();
886 
887     if (Elements[I].EllipsisLoc.isInvalid())
888       continue;
889 
890     if (!Elements[I].Key->containsUnexpandedParameterPack() &&
891         !Elements[I].Value->containsUnexpandedParameterPack()) {
892       Diag(Elements[I].EllipsisLoc,
893            diag::err_pack_expansion_without_parameter_packs)
894         << SourceRange(Elements[I].Key->getLocStart(),
895                        Elements[I].Value->getLocEnd());
896       return ExprError();
897     }
898 
899     HasPackExpansions = true;
900   }
901 
902 
903   QualType Ty
904     = Context.getObjCObjectPointerType(
905                                 Context.getObjCInterfaceType(NSDictionaryDecl));
906   return MaybeBindToTemporary(
907            ObjCDictionaryLiteral::Create(Context,
908                                          llvm::makeArrayRef(Elements,
909                                                             NumElements),
910                                          HasPackExpansions,
911                                          Ty,
912                                          DictionaryWithObjectsMethod, SR));
913 }
914 
BuildObjCEncodeExpression(SourceLocation AtLoc,TypeSourceInfo * EncodedTypeInfo,SourceLocation RParenLoc)915 ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
916                                       TypeSourceInfo *EncodedTypeInfo,
917                                       SourceLocation RParenLoc) {
918   QualType EncodedType = EncodedTypeInfo->getType();
919   QualType StrTy;
920   if (EncodedType->isDependentType())
921     StrTy = Context.DependentTy;
922   else {
923     if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
924         !EncodedType->isVoidType()) // void is handled too.
925       if (RequireCompleteType(AtLoc, EncodedType,
926                               diag::err_incomplete_type_objc_at_encode,
927                               EncodedTypeInfo->getTypeLoc()))
928         return ExprError();
929 
930     std::string Str;
931     Context.getObjCEncodingForType(EncodedType, Str);
932 
933     // The type of @encode is the same as the type of the corresponding string,
934     // which is an array type.
935     StrTy = Context.CharTy;
936     // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
937     if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings)
938       StrTy.addConst();
939     StrTy = Context.getConstantArrayType(StrTy, llvm::APInt(32, Str.size()+1),
940                                          ArrayType::Normal, 0);
941   }
942 
943   return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
944 }
945 
ParseObjCEncodeExpression(SourceLocation AtLoc,SourceLocation EncodeLoc,SourceLocation LParenLoc,ParsedType ty,SourceLocation RParenLoc)946 ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
947                                            SourceLocation EncodeLoc,
948                                            SourceLocation LParenLoc,
949                                            ParsedType ty,
950                                            SourceLocation RParenLoc) {
951   // FIXME: Preserve type source info ?
952   TypeSourceInfo *TInfo;
953   QualType EncodedType = GetTypeFromParser(ty, &TInfo);
954   if (!TInfo)
955     TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
956                                              PP.getLocForEndOfToken(LParenLoc));
957 
958   return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
959 }
960 
ParseObjCSelectorExpression(Selector Sel,SourceLocation AtLoc,SourceLocation SelLoc,SourceLocation LParenLoc,SourceLocation RParenLoc)961 ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
962                                              SourceLocation AtLoc,
963                                              SourceLocation SelLoc,
964                                              SourceLocation LParenLoc,
965                                              SourceLocation RParenLoc) {
966   ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
967                              SourceRange(LParenLoc, RParenLoc), false, false);
968   if (!Method)
969     Method = LookupFactoryMethodInGlobalPool(Sel,
970                                           SourceRange(LParenLoc, RParenLoc));
971   if (!Method) {
972     if (const ObjCMethodDecl *OM = SelectorsForTypoCorrection(Sel)) {
973       Selector MatchedSel = OM->getSelector();
974       SourceRange SelectorRange(LParenLoc.getLocWithOffset(1),
975                                 RParenLoc.getLocWithOffset(-1));
976       Diag(SelLoc, diag::warn_undeclared_selector_with_typo)
977         << Sel << MatchedSel
978         << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
979 
980     } else
981         Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
982   }
983 
984   if (!Method ||
985       Method->getImplementationControl() != ObjCMethodDecl::Optional) {
986     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
987       = ReferencedSelectors.find(Sel);
988     if (Pos == ReferencedSelectors.end())
989       ReferencedSelectors.insert(std::make_pair(Sel, AtLoc));
990   }
991 
992   // In ARC, forbid the user from using @selector for
993   // retain/release/autorelease/dealloc/retainCount.
994   if (getLangOpts().ObjCAutoRefCount) {
995     switch (Sel.getMethodFamily()) {
996     case OMF_retain:
997     case OMF_release:
998     case OMF_autorelease:
999     case OMF_retainCount:
1000     case OMF_dealloc:
1001       Diag(AtLoc, diag::err_arc_illegal_selector) <<
1002         Sel << SourceRange(LParenLoc, RParenLoc);
1003       break;
1004 
1005     case OMF_None:
1006     case OMF_alloc:
1007     case OMF_copy:
1008     case OMF_finalize:
1009     case OMF_init:
1010     case OMF_mutableCopy:
1011     case OMF_new:
1012     case OMF_self:
1013     case OMF_performSelector:
1014       break;
1015     }
1016   }
1017   QualType Ty = Context.getObjCSelType();
1018   return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
1019 }
1020 
ParseObjCProtocolExpression(IdentifierInfo * ProtocolId,SourceLocation AtLoc,SourceLocation ProtoLoc,SourceLocation LParenLoc,SourceLocation ProtoIdLoc,SourceLocation RParenLoc)1021 ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
1022                                              SourceLocation AtLoc,
1023                                              SourceLocation ProtoLoc,
1024                                              SourceLocation LParenLoc,
1025                                              SourceLocation ProtoIdLoc,
1026                                              SourceLocation RParenLoc) {
1027   ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoIdLoc);
1028   if (!PDecl) {
1029     Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
1030     return true;
1031   }
1032 
1033   QualType Ty = Context.getObjCProtoType();
1034   if (Ty.isNull())
1035     return true;
1036   Ty = Context.getObjCObjectPointerType(Ty);
1037   return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, ProtoIdLoc, RParenLoc);
1038 }
1039 
1040 /// Try to capture an implicit reference to 'self'.
tryCaptureObjCSelf(SourceLocation Loc)1041 ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
1042   DeclContext *DC = getFunctionLevelDeclContext();
1043 
1044   // If we're not in an ObjC method, error out.  Note that, unlike the
1045   // C++ case, we don't require an instance method --- class methods
1046   // still have a 'self', and we really do still need to capture it!
1047   ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
1048   if (!method)
1049     return 0;
1050 
1051   tryCaptureVariable(method->getSelfDecl(), Loc);
1052 
1053   return method;
1054 }
1055 
stripObjCInstanceType(ASTContext & Context,QualType T)1056 static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
1057   if (T == Context.getObjCInstanceType())
1058     return Context.getObjCIdType();
1059 
1060   return T;
1061 }
1062 
getMessageSendResultType(QualType ReceiverType,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage)1063 QualType Sema::getMessageSendResultType(QualType ReceiverType,
1064                                         ObjCMethodDecl *Method,
1065                                     bool isClassMessage, bool isSuperMessage) {
1066   assert(Method && "Must have a method");
1067   if (!Method->hasRelatedResultType())
1068     return Method->getSendResultType();
1069 
1070   // If a method has a related return type:
1071   //   - if the method found is an instance method, but the message send
1072   //     was a class message send, T is the declared return type of the method
1073   //     found
1074   if (Method->isInstanceMethod() && isClassMessage)
1075     return stripObjCInstanceType(Context, Method->getSendResultType());
1076 
1077   //   - if the receiver is super, T is a pointer to the class of the
1078   //     enclosing method definition
1079   if (isSuperMessage) {
1080     if (ObjCMethodDecl *CurMethod = getCurMethodDecl())
1081       if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface())
1082         return Context.getObjCObjectPointerType(
1083                                         Context.getObjCInterfaceType(Class));
1084   }
1085 
1086   //   - if the receiver is the name of a class U, T is a pointer to U
1087   if (ReceiverType->getAs<ObjCInterfaceType>() ||
1088       ReceiverType->isObjCQualifiedInterfaceType())
1089     return Context.getObjCObjectPointerType(ReceiverType);
1090   //   - if the receiver is of type Class or qualified Class type,
1091   //     T is the declared return type of the method.
1092   if (ReceiverType->isObjCClassType() ||
1093       ReceiverType->isObjCQualifiedClassType())
1094     return stripObjCInstanceType(Context, Method->getSendResultType());
1095 
1096   //   - if the receiver is id, qualified id, Class, or qualified Class, T
1097   //     is the receiver type, otherwise
1098   //   - T is the type of the receiver expression.
1099   return ReceiverType;
1100 }
1101 
1102 /// Look for an ObjC method whose result type exactly matches the given type.
1103 static const ObjCMethodDecl *
findExplicitInstancetypeDeclarer(const ObjCMethodDecl * MD,QualType instancetype)1104 findExplicitInstancetypeDeclarer(const ObjCMethodDecl *MD,
1105                                  QualType instancetype) {
1106   if (MD->getResultType() == instancetype) return MD;
1107 
1108   // For these purposes, a method in an @implementation overrides a
1109   // declaration in the @interface.
1110   if (const ObjCImplDecl *impl =
1111         dyn_cast<ObjCImplDecl>(MD->getDeclContext())) {
1112     const ObjCContainerDecl *iface;
1113     if (const ObjCCategoryImplDecl *catImpl =
1114           dyn_cast<ObjCCategoryImplDecl>(impl)) {
1115       iface = catImpl->getCategoryDecl();
1116     } else {
1117       iface = impl->getClassInterface();
1118     }
1119 
1120     const ObjCMethodDecl *ifaceMD =
1121       iface->getMethod(MD->getSelector(), MD->isInstanceMethod());
1122     if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype);
1123   }
1124 
1125   SmallVector<const ObjCMethodDecl *, 4> overrides;
1126   MD->getOverriddenMethods(overrides);
1127   for (unsigned i = 0, e = overrides.size(); i != e; ++i) {
1128     if (const ObjCMethodDecl *result =
1129           findExplicitInstancetypeDeclarer(overrides[i], instancetype))
1130       return result;
1131   }
1132 
1133   return 0;
1134 }
1135 
EmitRelatedResultTypeNoteForReturn(QualType destType)1136 void Sema::EmitRelatedResultTypeNoteForReturn(QualType destType) {
1137   // Only complain if we're in an ObjC method and the required return
1138   // type doesn't match the method's declared return type.
1139   ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurContext);
1140   if (!MD || !MD->hasRelatedResultType() ||
1141       Context.hasSameUnqualifiedType(destType, MD->getResultType()))
1142     return;
1143 
1144   // Look for a method overridden by this method which explicitly uses
1145   // 'instancetype'.
1146   if (const ObjCMethodDecl *overridden =
1147         findExplicitInstancetypeDeclarer(MD, Context.getObjCInstanceType())) {
1148     SourceLocation loc;
1149     SourceRange range;
1150     if (TypeSourceInfo *TSI = overridden->getResultTypeSourceInfo()) {
1151       range = TSI->getTypeLoc().getSourceRange();
1152       loc = range.getBegin();
1153     }
1154     if (loc.isInvalid())
1155       loc = overridden->getLocation();
1156     Diag(loc, diag::note_related_result_type_explicit)
1157       << /*current method*/ 1 << range;
1158     return;
1159   }
1160 
1161   // Otherwise, if we have an interesting method family, note that.
1162   // This should always trigger if the above didn't.
1163   if (ObjCMethodFamily family = MD->getMethodFamily())
1164     Diag(MD->getLocation(), diag::note_related_result_type_family)
1165       << /*current method*/ 1
1166       << family;
1167 }
1168 
EmitRelatedResultTypeNote(const Expr * E)1169 void Sema::EmitRelatedResultTypeNote(const Expr *E) {
1170   E = E->IgnoreParenImpCasts();
1171   const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
1172   if (!MsgSend)
1173     return;
1174 
1175   const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
1176   if (!Method)
1177     return;
1178 
1179   if (!Method->hasRelatedResultType())
1180     return;
1181 
1182   if (Context.hasSameUnqualifiedType(Method->getResultType()
1183                                                         .getNonReferenceType(),
1184                                      MsgSend->getType()))
1185     return;
1186 
1187   if (!Context.hasSameUnqualifiedType(Method->getResultType(),
1188                                       Context.getObjCInstanceType()))
1189     return;
1190 
1191   Diag(Method->getLocation(), diag::note_related_result_type_inferred)
1192     << Method->isInstanceMethod() << Method->getSelector()
1193     << MsgSend->getType();
1194 }
1195 
CheckMessageArgumentTypes(QualType ReceiverType,MultiExprArg Args,Selector Sel,ArrayRef<SourceLocation> SelectorLocs,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage,SourceLocation lbrac,SourceLocation rbrac,QualType & ReturnType,ExprValueKind & VK)1196 bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
1197                                      MultiExprArg Args,
1198                                      Selector Sel,
1199                                      ArrayRef<SourceLocation> SelectorLocs,
1200                                      ObjCMethodDecl *Method,
1201                                      bool isClassMessage, bool isSuperMessage,
1202                                      SourceLocation lbrac, SourceLocation rbrac,
1203                                      QualType &ReturnType, ExprValueKind &VK) {
1204   SourceLocation SelLoc;
1205   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
1206     SelLoc = SelectorLocs.front();
1207   else
1208     SelLoc = lbrac;
1209 
1210   if (!Method) {
1211     // Apply default argument promotion as for (C99 6.5.2.2p6).
1212     for (unsigned i = 0, e = Args.size(); i != e; i++) {
1213       if (Args[i]->isTypeDependent())
1214         continue;
1215 
1216       ExprResult result;
1217       if (getLangOpts().DebuggerSupport) {
1218         QualType paramTy; // ignored
1219         result = checkUnknownAnyArg(SelLoc, Args[i], paramTy);
1220       } else {
1221         result = DefaultArgumentPromotion(Args[i]);
1222       }
1223       if (result.isInvalid())
1224         return true;
1225       Args[i] = result.take();
1226     }
1227 
1228     unsigned DiagID;
1229     if (getLangOpts().ObjCAutoRefCount)
1230       DiagID = diag::err_arc_method_not_found;
1231     else
1232       DiagID = isClassMessage ? diag::warn_class_method_not_found
1233                               : diag::warn_inst_method_not_found;
1234     if (!getLangOpts().DebuggerSupport) {
1235       const ObjCMethodDecl *OMD = SelectorsForTypoCorrection(Sel, ReceiverType);
1236       if (OMD && !OMD->isInvalidDecl()) {
1237         if (getLangOpts().ObjCAutoRefCount)
1238           DiagID = diag::error_method_not_found_with_typo;
1239         else
1240           DiagID = isClassMessage ? diag::warn_class_method_not_found_with_typo
1241                                   : diag::warn_instance_method_not_found_with_typo;
1242         Selector MatchedSel = OMD->getSelector();
1243         SourceRange SelectorRange(SelectorLocs.front(), SelectorLocs.back());
1244         Diag(SelLoc, DiagID)
1245           << Sel<< isClassMessage << MatchedSel
1246           << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
1247       }
1248       else
1249         Diag(SelLoc, DiagID)
1250           << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
1251                                                 SelectorLocs.back());
1252       // Find the class to which we are sending this message.
1253       if (ReceiverType->isObjCObjectPointerType()) {
1254         if (ObjCInterfaceDecl *Class =
1255               ReceiverType->getAs<ObjCObjectPointerType>()->getInterfaceDecl())
1256           Diag(Class->getLocation(), diag::note_receiver_class_declared);
1257       }
1258     }
1259 
1260     // In debuggers, we want to use __unknown_anytype for these
1261     // results so that clients can cast them.
1262     if (getLangOpts().DebuggerSupport) {
1263       ReturnType = Context.UnknownAnyTy;
1264     } else {
1265       ReturnType = Context.getObjCIdType();
1266     }
1267     VK = VK_RValue;
1268     return false;
1269   }
1270 
1271   ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage,
1272                                         isSuperMessage);
1273   VK = Expr::getValueKindForType(Method->getResultType());
1274 
1275   unsigned NumNamedArgs = Sel.getNumArgs();
1276   // Method might have more arguments than selector indicates. This is due
1277   // to addition of c-style arguments in method.
1278   if (Method->param_size() > Sel.getNumArgs())
1279     NumNamedArgs = Method->param_size();
1280   // FIXME. This need be cleaned up.
1281   if (Args.size() < NumNamedArgs) {
1282     Diag(SelLoc, diag::err_typecheck_call_too_few_args)
1283       << 2 << NumNamedArgs << static_cast<unsigned>(Args.size());
1284     return false;
1285   }
1286 
1287   bool IsError = false;
1288   for (unsigned i = 0; i < NumNamedArgs; i++) {
1289     // We can't do any type-checking on a type-dependent argument.
1290     if (Args[i]->isTypeDependent())
1291       continue;
1292 
1293     Expr *argExpr = Args[i];
1294 
1295     ParmVarDecl *param = Method->param_begin()[i];
1296     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
1297 
1298     // Strip the unbridged-cast placeholder expression off unless it's
1299     // a consumed argument.
1300     if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
1301         !param->hasAttr<CFConsumedAttr>())
1302       argExpr = stripARCUnbridgedCast(argExpr);
1303 
1304     // If the parameter is __unknown_anytype, infer its type
1305     // from the argument.
1306     if (param->getType() == Context.UnknownAnyTy) {
1307       QualType paramType;
1308       ExprResult argE = checkUnknownAnyArg(SelLoc, argExpr, paramType);
1309       if (argE.isInvalid()) {
1310         IsError = true;
1311       } else {
1312         Args[i] = argE.take();
1313 
1314         // Update the parameter type in-place.
1315         param->setType(paramType);
1316       }
1317       continue;
1318     }
1319 
1320     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
1321                             param->getType(),
1322                             diag::err_call_incomplete_argument, argExpr))
1323       return true;
1324 
1325     InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1326                                                                       param);
1327     ExprResult ArgE = PerformCopyInitialization(Entity, SelLoc, Owned(argExpr));
1328     if (ArgE.isInvalid())
1329       IsError = true;
1330     else
1331       Args[i] = ArgE.takeAs<Expr>();
1332   }
1333 
1334   // Promote additional arguments to variadic methods.
1335   if (Method->isVariadic()) {
1336     for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
1337       if (Args[i]->isTypeDependent())
1338         continue;
1339 
1340       ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
1341                                                         0);
1342       IsError |= Arg.isInvalid();
1343       Args[i] = Arg.take();
1344     }
1345   } else {
1346     // Check for extra arguments to non-variadic methods.
1347     if (Args.size() != NumNamedArgs) {
1348       Diag(Args[NumNamedArgs]->getLocStart(),
1349            diag::err_typecheck_call_too_many_args)
1350         << 2 /*method*/ << NumNamedArgs << static_cast<unsigned>(Args.size())
1351         << Method->getSourceRange()
1352         << SourceRange(Args[NumNamedArgs]->getLocStart(),
1353                        Args.back()->getLocEnd());
1354     }
1355   }
1356 
1357   DiagnoseSentinelCalls(Method, SelLoc, Args);
1358 
1359   // Do additional checkings on method.
1360   IsError |= CheckObjCMethodCall(
1361                   Method, SelLoc,
1362                   llvm::makeArrayRef<const Expr *>(Args.data(), Args.size()));
1363 
1364   return IsError;
1365 }
1366 
isSelfExpr(Expr * receiver)1367 bool Sema::isSelfExpr(Expr *receiver) {
1368   // 'self' is objc 'self' in an objc method only.
1369   ObjCMethodDecl *method =
1370     dyn_cast_or_null<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
1371   if (!method) return false;
1372 
1373   receiver = receiver->IgnoreParenLValueCasts();
1374   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
1375     if (DRE->getDecl() == method->getSelfDecl())
1376       return true;
1377   return false;
1378 }
1379 
1380 /// LookupMethodInType - Look up a method in an ObjCObjectType.
LookupMethodInObjectType(Selector sel,QualType type,bool isInstance)1381 ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
1382                                                bool isInstance) {
1383   const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
1384   if (ObjCInterfaceDecl *iface = objType->getInterface()) {
1385     // Look it up in the main interface (and categories, etc.)
1386     if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
1387       return method;
1388 
1389     // Okay, look for "private" methods declared in any
1390     // @implementations we've seen.
1391     if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
1392       return method;
1393   }
1394 
1395   // Check qualifiers.
1396   for (ObjCObjectType::qual_iterator
1397          i = objType->qual_begin(), e = objType->qual_end(); i != e; ++i)
1398     if (ObjCMethodDecl *method = (*i)->lookupMethod(sel, isInstance))
1399       return method;
1400 
1401   return 0;
1402 }
1403 
1404 /// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1405 /// list of a qualified objective pointer type.
LookupMethodInQualifiedType(Selector Sel,const ObjCObjectPointerType * OPT,bool Instance)1406 ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
1407                                               const ObjCObjectPointerType *OPT,
1408                                               bool Instance)
1409 {
1410   ObjCMethodDecl *MD = 0;
1411   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1412        E = OPT->qual_end(); I != E; ++I) {
1413     ObjCProtocolDecl *PROTO = (*I);
1414     if ((MD = PROTO->lookupMethod(Sel, Instance))) {
1415       return MD;
1416     }
1417   }
1418   return 0;
1419 }
1420 
DiagnoseARCUseOfWeakReceiver(Sema & S,Expr * Receiver)1421 static void DiagnoseARCUseOfWeakReceiver(Sema &S, Expr *Receiver) {
1422   if (!Receiver)
1423     return;
1424 
1425   if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Receiver))
1426     Receiver = OVE->getSourceExpr();
1427 
1428   Expr *RExpr = Receiver->IgnoreParenImpCasts();
1429   SourceLocation Loc = RExpr->getLocStart();
1430   QualType T = RExpr->getType();
1431   const ObjCPropertyDecl *PDecl = 0;
1432   const ObjCMethodDecl *GDecl = 0;
1433   if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(RExpr)) {
1434     RExpr = POE->getSyntacticForm();
1435     if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(RExpr)) {
1436       if (PRE->isImplicitProperty()) {
1437         GDecl = PRE->getImplicitPropertyGetter();
1438         if (GDecl) {
1439           T = GDecl->getResultType();
1440         }
1441       }
1442       else {
1443         PDecl = PRE->getExplicitProperty();
1444         if (PDecl) {
1445           T = PDecl->getType();
1446         }
1447       }
1448     }
1449   }
1450   else if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RExpr)) {
1451     // See if receiver is a method which envokes a synthesized getter
1452     // backing a 'weak' property.
1453     ObjCMethodDecl *Method = ME->getMethodDecl();
1454     if (Method && Method->getSelector().getNumArgs() == 0) {
1455       PDecl = Method->findPropertyDecl();
1456       if (PDecl)
1457         T = PDecl->getType();
1458     }
1459   }
1460 
1461   if (T.getObjCLifetime() != Qualifiers::OCL_Weak) {
1462     if (!PDecl)
1463       return;
1464     if (!(PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak))
1465       return;
1466   }
1467 
1468   S.Diag(Loc, diag::warn_receiver_is_weak)
1469     << ((!PDecl && !GDecl) ? 0 : (PDecl ? 1 : 2));
1470 
1471   if (PDecl)
1472     S.Diag(PDecl->getLocation(), diag::note_property_declare);
1473   else if (GDecl)
1474     S.Diag(GDecl->getLocation(), diag::note_method_declared_at) << GDecl;
1475 
1476   S.Diag(Loc, diag::note_arc_assign_to_strong);
1477 }
1478 
1479 /// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1480 /// objective C interface.  This is a property reference expression.
1481 ExprResult Sema::
HandleExprPropertyRefExpr(const ObjCObjectPointerType * OPT,Expr * BaseExpr,SourceLocation OpLoc,DeclarationName MemberName,SourceLocation MemberLoc,SourceLocation SuperLoc,QualType SuperType,bool Super)1482 HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
1483                           Expr *BaseExpr, SourceLocation OpLoc,
1484                           DeclarationName MemberName,
1485                           SourceLocation MemberLoc,
1486                           SourceLocation SuperLoc, QualType SuperType,
1487                           bool Super) {
1488   const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
1489   ObjCInterfaceDecl *IFace = IFaceT->getDecl();
1490 
1491   if (!MemberName.isIdentifier()) {
1492     Diag(MemberLoc, diag::err_invalid_property_name)
1493       << MemberName << QualType(OPT, 0);
1494     return ExprError();
1495   }
1496 
1497   IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1498 
1499   SourceRange BaseRange = Super? SourceRange(SuperLoc)
1500                                : BaseExpr->getSourceRange();
1501   if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
1502                           diag::err_property_not_found_forward_class,
1503                           MemberName, BaseRange))
1504     return ExprError();
1505 
1506   // Search for a declared property first.
1507   if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
1508     // Check whether we can reference this property.
1509     if (DiagnoseUseOfDecl(PD, MemberLoc))
1510       return ExprError();
1511     if (Super)
1512       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1513                                                      VK_LValue, OK_ObjCProperty,
1514                                                      MemberLoc,
1515                                                      SuperLoc, SuperType));
1516     else
1517       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1518                                                      VK_LValue, OK_ObjCProperty,
1519                                                      MemberLoc, BaseExpr));
1520   }
1521   // Check protocols on qualified interfaces.
1522   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1523        E = OPT->qual_end(); I != E; ++I)
1524     if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) {
1525       // Check whether we can reference this property.
1526       if (DiagnoseUseOfDecl(PD, MemberLoc))
1527         return ExprError();
1528 
1529       if (Super)
1530         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1531                                                        Context.PseudoObjectTy,
1532                                                        VK_LValue,
1533                                                        OK_ObjCProperty,
1534                                                        MemberLoc,
1535                                                        SuperLoc, SuperType));
1536       else
1537         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1538                                                        Context.PseudoObjectTy,
1539                                                        VK_LValue,
1540                                                        OK_ObjCProperty,
1541                                                        MemberLoc,
1542                                                        BaseExpr));
1543     }
1544   // If that failed, look for an "implicit" property by seeing if the nullary
1545   // selector is implemented.
1546 
1547   // FIXME: The logic for looking up nullary and unary selectors should be
1548   // shared with the code in ActOnInstanceMessage.
1549 
1550   Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
1551   ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
1552 
1553   // May be founf in property's qualified list.
1554   if (!Getter)
1555     Getter = LookupMethodInQualifiedType(Sel, OPT, true);
1556 
1557   // If this reference is in an @implementation, check for 'private' methods.
1558   if (!Getter)
1559     Getter = IFace->lookupPrivateMethod(Sel);
1560 
1561   if (Getter) {
1562     // Check if we can reference this property.
1563     if (DiagnoseUseOfDecl(Getter, MemberLoc))
1564       return ExprError();
1565   }
1566   // If we found a getter then this may be a valid dot-reference, we
1567   // will look for the matching setter, in case it is needed.
1568   Selector SetterSel =
1569     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1570                                            PP.getSelectorTable(), Member);
1571   ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
1572 
1573   // May be founf in property's qualified list.
1574   if (!Setter)
1575     Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
1576 
1577   if (!Setter) {
1578     // If this reference is in an @implementation, also check for 'private'
1579     // methods.
1580     Setter = IFace->lookupPrivateMethod(SetterSel);
1581   }
1582 
1583   if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
1584     return ExprError();
1585 
1586   if (Getter || Setter) {
1587     if (Super)
1588       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1589                                                      Context.PseudoObjectTy,
1590                                                      VK_LValue, OK_ObjCProperty,
1591                                                      MemberLoc,
1592                                                      SuperLoc, SuperType));
1593     else
1594       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1595                                                      Context.PseudoObjectTy,
1596                                                      VK_LValue, OK_ObjCProperty,
1597                                                      MemberLoc, BaseExpr));
1598 
1599   }
1600 
1601   // Attempt to correct for typos in property names.
1602   DeclFilterCCC<ObjCPropertyDecl> Validator;
1603   if (TypoCorrection Corrected = CorrectTypo(
1604       DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName, NULL,
1605       NULL, Validator, IFace, false, OPT)) {
1606     ObjCPropertyDecl *Property =
1607         Corrected.getCorrectionDeclAs<ObjCPropertyDecl>();
1608     DeclarationName TypoResult = Corrected.getCorrection();
1609     Diag(MemberLoc, diag::err_property_not_found_suggest)
1610       << MemberName << QualType(OPT, 0) << TypoResult
1611       << FixItHint::CreateReplacement(MemberLoc, TypoResult.getAsString());
1612     Diag(Property->getLocation(), diag::note_previous_decl)
1613       << Property->getDeclName();
1614     return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
1615                                      TypoResult, MemberLoc,
1616                                      SuperLoc, SuperType, Super);
1617   }
1618   ObjCInterfaceDecl *ClassDeclared;
1619   if (ObjCIvarDecl *Ivar =
1620       IFace->lookupInstanceVariable(Member, ClassDeclared)) {
1621     QualType T = Ivar->getType();
1622     if (const ObjCObjectPointerType * OBJPT =
1623         T->getAsObjCInterfacePointerType()) {
1624       if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
1625                               diag::err_property_not_as_forward_class,
1626                               MemberName, BaseExpr))
1627         return ExprError();
1628     }
1629     Diag(MemberLoc,
1630          diag::err_ivar_access_using_property_syntax_suggest)
1631     << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
1632     << FixItHint::CreateReplacement(OpLoc, "->");
1633     return ExprError();
1634   }
1635 
1636   Diag(MemberLoc, diag::err_property_not_found)
1637     << MemberName << QualType(OPT, 0);
1638   if (Setter)
1639     Diag(Setter->getLocation(), diag::note_getter_unavailable)
1640           << MemberName << BaseExpr->getSourceRange();
1641   return ExprError();
1642 }
1643 
1644 
1645 
1646 ExprResult Sema::
ActOnClassPropertyRefExpr(IdentifierInfo & receiverName,IdentifierInfo & propertyName,SourceLocation receiverNameLoc,SourceLocation propertyNameLoc)1647 ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
1648                           IdentifierInfo &propertyName,
1649                           SourceLocation receiverNameLoc,
1650                           SourceLocation propertyNameLoc) {
1651 
1652   IdentifierInfo *receiverNamePtr = &receiverName;
1653   ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
1654                                                   receiverNameLoc);
1655 
1656   bool IsSuper = false;
1657   if (IFace == 0) {
1658     // If the "receiver" is 'super' in a method, handle it as an expression-like
1659     // property reference.
1660     if (receiverNamePtr->isStr("super")) {
1661       IsSuper = true;
1662 
1663       if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
1664         if (CurMethod->isInstanceMethod()) {
1665           ObjCInterfaceDecl *Super =
1666             CurMethod->getClassInterface()->getSuperClass();
1667           if (!Super) {
1668             // The current class does not have a superclass.
1669             Diag(receiverNameLoc, diag::error_root_class_cannot_use_super)
1670             << CurMethod->getClassInterface()->getIdentifier();
1671             return ExprError();
1672           }
1673           QualType T = Context.getObjCInterfaceType(Super);
1674           T = Context.getObjCObjectPointerType(T);
1675 
1676           return HandleExprPropertyRefExpr(T->getAsObjCInterfacePointerType(),
1677                                            /*BaseExpr*/0,
1678                                            SourceLocation()/*OpLoc*/,
1679                                            &propertyName,
1680                                            propertyNameLoc,
1681                                            receiverNameLoc, T, true);
1682         }
1683 
1684         // Otherwise, if this is a class method, try dispatching to our
1685         // superclass.
1686         IFace = CurMethod->getClassInterface()->getSuperClass();
1687       }
1688     }
1689 
1690     if (IFace == 0) {
1691       Diag(receiverNameLoc, diag::err_expected_ident_or_lparen);
1692       return ExprError();
1693     }
1694   }
1695 
1696   // Search for a declared property first.
1697   Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
1698   ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
1699 
1700   // If this reference is in an @implementation, check for 'private' methods.
1701   if (!Getter)
1702     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1703       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1704         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1705           Getter = ImpDecl->getClassMethod(Sel);
1706 
1707   if (Getter) {
1708     // FIXME: refactor/share with ActOnMemberReference().
1709     // Check if we can reference this property.
1710     if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
1711       return ExprError();
1712   }
1713 
1714   // Look for the matching setter, in case it is needed.
1715   Selector SetterSel =
1716     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1717                                            PP.getSelectorTable(),
1718                                            &propertyName);
1719 
1720   ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1721   if (!Setter) {
1722     // If this reference is in an @implementation, also check for 'private'
1723     // methods.
1724     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1725       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1726         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1727           Setter = ImpDecl->getClassMethod(SetterSel);
1728   }
1729   // Look through local category implementations associated with the class.
1730   if (!Setter)
1731     Setter = IFace->getCategoryClassMethod(SetterSel);
1732 
1733   if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
1734     return ExprError();
1735 
1736   if (Getter || Setter) {
1737     if (IsSuper)
1738     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1739                                                    Context.PseudoObjectTy,
1740                                                    VK_LValue, OK_ObjCProperty,
1741                                                    propertyNameLoc,
1742                                                    receiverNameLoc,
1743                                           Context.getObjCInterfaceType(IFace)));
1744 
1745     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1746                                                    Context.PseudoObjectTy,
1747                                                    VK_LValue, OK_ObjCProperty,
1748                                                    propertyNameLoc,
1749                                                    receiverNameLoc, IFace));
1750   }
1751   return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
1752                      << &propertyName << Context.getObjCInterfaceType(IFace));
1753 }
1754 
1755 namespace {
1756 
1757 class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
1758  public:
ObjCInterfaceOrSuperCCC(ObjCMethodDecl * Method)1759   ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
1760     // Determine whether "super" is acceptable in the current context.
1761     if (Method && Method->getClassInterface())
1762       WantObjCSuper = Method->getClassInterface()->getSuperClass();
1763   }
1764 
ValidateCandidate(const TypoCorrection & candidate)1765   virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1766     return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
1767         candidate.isKeyword("super");
1768   }
1769 };
1770 
1771 }
1772 
getObjCMessageKind(Scope * S,IdentifierInfo * Name,SourceLocation NameLoc,bool IsSuper,bool HasTrailingDot,ParsedType & ReceiverType)1773 Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
1774                                                IdentifierInfo *Name,
1775                                                SourceLocation NameLoc,
1776                                                bool IsSuper,
1777                                                bool HasTrailingDot,
1778                                                ParsedType &ReceiverType) {
1779   ReceiverType = ParsedType();
1780 
1781   // If the identifier is "super" and there is no trailing dot, we're
1782   // messaging super. If the identifier is "super" and there is a
1783   // trailing dot, it's an instance message.
1784   if (IsSuper && S->isInObjcMethodScope())
1785     return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
1786 
1787   LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1788   LookupName(Result, S);
1789 
1790   switch (Result.getResultKind()) {
1791   case LookupResult::NotFound:
1792     // Normal name lookup didn't find anything. If we're in an
1793     // Objective-C method, look for ivars. If we find one, we're done!
1794     // FIXME: This is a hack. Ivar lookup should be part of normal
1795     // lookup.
1796     if (ObjCMethodDecl *Method = getCurMethodDecl()) {
1797       if (!Method->getClassInterface()) {
1798         // Fall back: let the parser try to parse it as an instance message.
1799         return ObjCInstanceMessage;
1800       }
1801 
1802       ObjCInterfaceDecl *ClassDeclared;
1803       if (Method->getClassInterface()->lookupInstanceVariable(Name,
1804                                                               ClassDeclared))
1805         return ObjCInstanceMessage;
1806     }
1807 
1808     // Break out; we'll perform typo correction below.
1809     break;
1810 
1811   case LookupResult::NotFoundInCurrentInstantiation:
1812   case LookupResult::FoundOverloaded:
1813   case LookupResult::FoundUnresolvedValue:
1814   case LookupResult::Ambiguous:
1815     Result.suppressDiagnostics();
1816     return ObjCInstanceMessage;
1817 
1818   case LookupResult::Found: {
1819     // If the identifier is a class or not, and there is a trailing dot,
1820     // it's an instance message.
1821     if (HasTrailingDot)
1822       return ObjCInstanceMessage;
1823     // We found something. If it's a type, then we have a class
1824     // message. Otherwise, it's an instance message.
1825     NamedDecl *ND = Result.getFoundDecl();
1826     QualType T;
1827     if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
1828       T = Context.getObjCInterfaceType(Class);
1829     else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND)) {
1830       T = Context.getTypeDeclType(Type);
1831       DiagnoseUseOfDecl(Type, NameLoc);
1832     }
1833     else
1834       return ObjCInstanceMessage;
1835 
1836     //  We have a class message, and T is the type we're
1837     //  messaging. Build source-location information for it.
1838     TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1839     ReceiverType = CreateParsedType(T, TSInfo);
1840     return ObjCClassMessage;
1841   }
1842   }
1843 
1844   ObjCInterfaceOrSuperCCC Validator(getCurMethodDecl());
1845   if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(),
1846                                              Result.getLookupKind(), S, NULL,
1847                                              Validator)) {
1848     if (Corrected.isKeyword()) {
1849       // If we've found the keyword "super" (the only keyword that would be
1850       // returned by CorrectTypo), this is a send to super.
1851       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1852         << Name << Corrected.getCorrection()
1853         << FixItHint::CreateReplacement(SourceRange(NameLoc), "super");
1854       return ObjCSuperMessage;
1855     } else if (ObjCInterfaceDecl *Class =
1856                Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1857       // If we found a declaration, correct when it refers to an Objective-C
1858       // class.
1859       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1860         << Name << Corrected.getCorrection()
1861         << FixItHint::CreateReplacement(SourceRange(NameLoc),
1862                                         Class->getNameAsString());
1863       Diag(Class->getLocation(), diag::note_previous_decl)
1864         << Corrected.getCorrection();
1865 
1866       QualType T = Context.getObjCInterfaceType(Class);
1867       TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1868       ReceiverType = CreateParsedType(T, TSInfo);
1869       return ObjCClassMessage;
1870     }
1871   }
1872 
1873   // Fall back: let the parser try to parse it as an instance message.
1874   return ObjCInstanceMessage;
1875 }
1876 
ActOnSuperMessage(Scope * S,SourceLocation SuperLoc,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)1877 ExprResult Sema::ActOnSuperMessage(Scope *S,
1878                                    SourceLocation SuperLoc,
1879                                    Selector Sel,
1880                                    SourceLocation LBracLoc,
1881                                    ArrayRef<SourceLocation> SelectorLocs,
1882                                    SourceLocation RBracLoc,
1883                                    MultiExprArg Args) {
1884   // Determine whether we are inside a method or not.
1885   ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
1886   if (!Method) {
1887     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
1888     return ExprError();
1889   }
1890 
1891   ObjCInterfaceDecl *Class = Method->getClassInterface();
1892   if (!Class) {
1893     Diag(SuperLoc, diag::error_no_super_class_message)
1894       << Method->getDeclName();
1895     return ExprError();
1896   }
1897 
1898   ObjCInterfaceDecl *Super = Class->getSuperClass();
1899   if (!Super) {
1900     // The current class does not have a superclass.
1901     Diag(SuperLoc, diag::error_root_class_cannot_use_super)
1902       << Class->getIdentifier();
1903     return ExprError();
1904   }
1905 
1906   // We are in a method whose class has a superclass, so 'super'
1907   // is acting as a keyword.
1908   if (Method->getSelector() == Sel)
1909     getCurFunction()->ObjCShouldCallSuper = false;
1910 
1911   if (Method->isInstanceMethod()) {
1912     // Since we are in an instance method, this is an instance
1913     // message to the superclass instance.
1914     QualType SuperTy = Context.getObjCInterfaceType(Super);
1915     SuperTy = Context.getObjCObjectPointerType(SuperTy);
1916     return BuildInstanceMessage(0, SuperTy, SuperLoc,
1917                                 Sel, /*Method=*/0,
1918                                 LBracLoc, SelectorLocs, RBracLoc, Args);
1919   }
1920 
1921   // Since we are in a class method, this is a class message to
1922   // the superclass.
1923   return BuildClassMessage(/*ReceiverTypeInfo=*/0,
1924                            Context.getObjCInterfaceType(Super),
1925                            SuperLoc, Sel, /*Method=*/0,
1926                            LBracLoc, SelectorLocs, RBracLoc, Args);
1927 }
1928 
1929 
BuildClassMessageImplicit(QualType ReceiverType,bool isSuperReceiver,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)1930 ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
1931                                            bool isSuperReceiver,
1932                                            SourceLocation Loc,
1933                                            Selector Sel,
1934                                            ObjCMethodDecl *Method,
1935                                            MultiExprArg Args) {
1936   TypeSourceInfo *receiverTypeInfo = 0;
1937   if (!ReceiverType.isNull())
1938     receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
1939 
1940   return BuildClassMessage(receiverTypeInfo, ReceiverType,
1941                           /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
1942                            Sel, Method, Loc, Loc, Loc, Args,
1943                            /*isImplicit=*/true);
1944 
1945 }
1946 
applyCocoaAPICheck(Sema & S,const ObjCMessageExpr * Msg,unsigned DiagID,bool (* refactor)(const ObjCMessageExpr *,const NSAPI &,edit::Commit &))1947 static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
1948                                unsigned DiagID,
1949                                bool (*refactor)(const ObjCMessageExpr *,
1950                                               const NSAPI &, edit::Commit &)) {
1951   SourceLocation MsgLoc = Msg->getExprLoc();
1952   if (S.Diags.getDiagnosticLevel(DiagID, MsgLoc) == DiagnosticsEngine::Ignored)
1953     return;
1954 
1955   SourceManager &SM = S.SourceMgr;
1956   edit::Commit ECommit(SM, S.LangOpts);
1957   if (refactor(Msg,*S.NSAPIObj, ECommit)) {
1958     DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
1959                         << Msg->getSelector() << Msg->getSourceRange();
1960     // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
1961     if (!ECommit.isCommitable())
1962       return;
1963     for (edit::Commit::edit_iterator
1964            I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
1965       const edit::Commit::Edit &Edit = *I;
1966       switch (Edit.Kind) {
1967       case edit::Commit::Act_Insert:
1968         Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
1969                                                         Edit.Text,
1970                                                         Edit.BeforePrev));
1971         break;
1972       case edit::Commit::Act_InsertFromRange:
1973         Builder.AddFixItHint(
1974             FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
1975                                                 Edit.getInsertFromRange(SM),
1976                                                 Edit.BeforePrev));
1977         break;
1978       case edit::Commit::Act_Remove:
1979         Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
1980         break;
1981       }
1982     }
1983   }
1984 }
1985 
checkCocoaAPI(Sema & S,const ObjCMessageExpr * Msg)1986 static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
1987   applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
1988                      edit::rewriteObjCRedundantCallWithLiteral);
1989 }
1990 
1991 /// \brief Build an Objective-C class message expression.
1992 ///
1993 /// This routine takes care of both normal class messages and
1994 /// class messages to the superclass.
1995 ///
1996 /// \param ReceiverTypeInfo Type source information that describes the
1997 /// receiver of this message. This may be NULL, in which case we are
1998 /// sending to the superclass and \p SuperLoc must be a valid source
1999 /// location.
2000 
2001 /// \param ReceiverType The type of the object receiving the
2002 /// message. When \p ReceiverTypeInfo is non-NULL, this is the same
2003 /// type as that refers to. For a superclass send, this is the type of
2004 /// the superclass.
2005 ///
2006 /// \param SuperLoc The location of the "super" keyword in a
2007 /// superclass message.
2008 ///
2009 /// \param Sel The selector to which the message is being sent.
2010 ///
2011 /// \param Method The method that this class message is invoking, if
2012 /// already known.
2013 ///
2014 /// \param LBracLoc The location of the opening square bracket ']'.
2015 ///
2016 /// \param RBracLoc The location of the closing square bracket ']'.
2017 ///
2018 /// \param ArgsIn The message arguments.
BuildClassMessage(TypeSourceInfo * ReceiverTypeInfo,QualType ReceiverType,SourceLocation SuperLoc,Selector Sel,ObjCMethodDecl * Method,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg ArgsIn,bool isImplicit)2019 ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
2020                                    QualType ReceiverType,
2021                                    SourceLocation SuperLoc,
2022                                    Selector Sel,
2023                                    ObjCMethodDecl *Method,
2024                                    SourceLocation LBracLoc,
2025                                    ArrayRef<SourceLocation> SelectorLocs,
2026                                    SourceLocation RBracLoc,
2027                                    MultiExprArg ArgsIn,
2028                                    bool isImplicit) {
2029   SourceLocation Loc = SuperLoc.isValid()? SuperLoc
2030     : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
2031   if (LBracLoc.isInvalid()) {
2032     Diag(Loc, diag::err_missing_open_square_message_send)
2033       << FixItHint::CreateInsertion(Loc, "[");
2034     LBracLoc = Loc;
2035   }
2036   SourceLocation SelLoc;
2037   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2038     SelLoc = SelectorLocs.front();
2039   else
2040     SelLoc = Loc;
2041 
2042   if (ReceiverType->isDependentType()) {
2043     // If the receiver type is dependent, we can't type-check anything
2044     // at this point. Build a dependent expression.
2045     unsigned NumArgs = ArgsIn.size();
2046     Expr **Args = ArgsIn.data();
2047     assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2048     return Owned(ObjCMessageExpr::Create(Context, ReceiverType,
2049                                          VK_RValue, LBracLoc, ReceiverTypeInfo,
2050                                          Sel, SelectorLocs, /*Method=*/0,
2051                                          makeArrayRef(Args, NumArgs),RBracLoc,
2052                                          isImplicit));
2053   }
2054 
2055   // Find the class to which we are sending this message.
2056   ObjCInterfaceDecl *Class = 0;
2057   const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
2058   if (!ClassType || !(Class = ClassType->getInterface())) {
2059     Diag(Loc, diag::err_invalid_receiver_class_message)
2060       << ReceiverType;
2061     return ExprError();
2062   }
2063   assert(Class && "We don't know which class we're messaging?");
2064   // objc++ diagnoses during typename annotation.
2065   if (!getLangOpts().CPlusPlus)
2066     (void)DiagnoseUseOfDecl(Class, SelLoc);
2067   // Find the method we are messaging.
2068   if (!Method) {
2069     SourceRange TypeRange
2070       = SuperLoc.isValid()? SourceRange(SuperLoc)
2071                           : ReceiverTypeInfo->getTypeLoc().getSourceRange();
2072     if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
2073                             (getLangOpts().ObjCAutoRefCount
2074                                ? diag::err_arc_receiver_forward_class
2075                                : diag::warn_receiver_forward_class),
2076                             TypeRange)) {
2077       // A forward class used in messaging is treated as a 'Class'
2078       Method = LookupFactoryMethodInGlobalPool(Sel,
2079                                                SourceRange(LBracLoc, RBracLoc));
2080       if (Method && !getLangOpts().ObjCAutoRefCount)
2081         Diag(Method->getLocation(), diag::note_method_sent_forward_class)
2082           << Method->getDeclName();
2083     }
2084     if (!Method)
2085       Method = Class->lookupClassMethod(Sel);
2086 
2087     // If we have an implementation in scope, check "private" methods.
2088     if (!Method)
2089       Method = Class->lookupPrivateClassMethod(Sel);
2090 
2091     if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2092       return ExprError();
2093   }
2094 
2095   // Check the argument types and determine the result type.
2096   QualType ReturnType;
2097   ExprValueKind VK = VK_RValue;
2098 
2099   unsigned NumArgs = ArgsIn.size();
2100   Expr **Args = ArgsIn.data();
2101   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2102                                 Sel, SelectorLocs,
2103                                 Method, true,
2104                                 SuperLoc.isValid(), LBracLoc, RBracLoc,
2105                                 ReturnType, VK))
2106     return ExprError();
2107 
2108   if (Method && !Method->getResultType()->isVoidType() &&
2109       RequireCompleteType(LBracLoc, Method->getResultType(),
2110                           diag::err_illegal_message_expr_incomplete_type))
2111     return ExprError();
2112 
2113   // Construct the appropriate ObjCMessageExpr.
2114   ObjCMessageExpr *Result;
2115   if (SuperLoc.isValid())
2116     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2117                                      SuperLoc, /*IsInstanceSuper=*/false,
2118                                      ReceiverType, Sel, SelectorLocs,
2119                                      Method, makeArrayRef(Args, NumArgs),
2120                                      RBracLoc, isImplicit);
2121   else {
2122     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2123                                      ReceiverTypeInfo, Sel, SelectorLocs,
2124                                      Method, makeArrayRef(Args, NumArgs),
2125                                      RBracLoc, isImplicit);
2126     if (!isImplicit)
2127       checkCocoaAPI(*this, Result);
2128   }
2129   return MaybeBindToTemporary(Result);
2130 }
2131 
2132 // ActOnClassMessage - used for both unary and keyword messages.
2133 // ArgExprs is optional - if it is present, the number of expressions
2134 // is obtained from Sel.getNumArgs().
ActOnClassMessage(Scope * S,ParsedType Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2135 ExprResult Sema::ActOnClassMessage(Scope *S,
2136                                    ParsedType Receiver,
2137                                    Selector Sel,
2138                                    SourceLocation LBracLoc,
2139                                    ArrayRef<SourceLocation> SelectorLocs,
2140                                    SourceLocation RBracLoc,
2141                                    MultiExprArg Args) {
2142   TypeSourceInfo *ReceiverTypeInfo;
2143   QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
2144   if (ReceiverType.isNull())
2145     return ExprError();
2146 
2147 
2148   if (!ReceiverTypeInfo)
2149     ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
2150 
2151   return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
2152                            /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2153                            LBracLoc, SelectorLocs, RBracLoc, Args);
2154 }
2155 
BuildInstanceMessageImplicit(Expr * Receiver,QualType ReceiverType,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)2156 ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
2157                                               QualType ReceiverType,
2158                                               SourceLocation Loc,
2159                                               Selector Sel,
2160                                               ObjCMethodDecl *Method,
2161                                               MultiExprArg Args) {
2162   return BuildInstanceMessage(Receiver, ReceiverType,
2163                               /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
2164                               Sel, Method, Loc, Loc, Loc, Args,
2165                               /*isImplicit=*/true);
2166 }
2167 
2168 /// \brief Build an Objective-C instance message expression.
2169 ///
2170 /// This routine takes care of both normal instance messages and
2171 /// instance messages to the superclass instance.
2172 ///
2173 /// \param Receiver The expression that computes the object that will
2174 /// receive this message. This may be empty, in which case we are
2175 /// sending to the superclass instance and \p SuperLoc must be a valid
2176 /// source location.
2177 ///
2178 /// \param ReceiverType The (static) type of the object receiving the
2179 /// message. When a \p Receiver expression is provided, this is the
2180 /// same type as that expression. For a superclass instance send, this
2181 /// is a pointer to the type of the superclass.
2182 ///
2183 /// \param SuperLoc The location of the "super" keyword in a
2184 /// superclass instance message.
2185 ///
2186 /// \param Sel The selector to which the message is being sent.
2187 ///
2188 /// \param Method The method that this instance message is invoking, if
2189 /// already known.
2190 ///
2191 /// \param LBracLoc The location of the opening square bracket ']'.
2192 ///
2193 /// \param RBracLoc The location of the closing square bracket ']'.
2194 ///
2195 /// \param ArgsIn The message arguments.
BuildInstanceMessage(Expr * Receiver,QualType ReceiverType,SourceLocation SuperLoc,Selector Sel,ObjCMethodDecl * Method,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg ArgsIn,bool isImplicit)2196 ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
2197                                       QualType ReceiverType,
2198                                       SourceLocation SuperLoc,
2199                                       Selector Sel,
2200                                       ObjCMethodDecl *Method,
2201                                       SourceLocation LBracLoc,
2202                                       ArrayRef<SourceLocation> SelectorLocs,
2203                                       SourceLocation RBracLoc,
2204                                       MultiExprArg ArgsIn,
2205                                       bool isImplicit) {
2206   // The location of the receiver.
2207   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
2208   SourceRange RecRange =
2209       SuperLoc.isValid()? SuperLoc : Receiver->getSourceRange();
2210   SourceLocation SelLoc;
2211   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2212     SelLoc = SelectorLocs.front();
2213   else
2214     SelLoc = Loc;
2215 
2216   if (LBracLoc.isInvalid()) {
2217     Diag(Loc, diag::err_missing_open_square_message_send)
2218       << FixItHint::CreateInsertion(Loc, "[");
2219     LBracLoc = Loc;
2220   }
2221 
2222   // If we have a receiver expression, perform appropriate promotions
2223   // and determine receiver type.
2224   if (Receiver) {
2225     if (Receiver->hasPlaceholderType()) {
2226       ExprResult Result;
2227       if (Receiver->getType() == Context.UnknownAnyTy)
2228         Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
2229       else
2230         Result = CheckPlaceholderExpr(Receiver);
2231       if (Result.isInvalid()) return ExprError();
2232       Receiver = Result.take();
2233     }
2234 
2235     if (Receiver->isTypeDependent()) {
2236       // If the receiver is type-dependent, we can't type-check anything
2237       // at this point. Build a dependent expression.
2238       unsigned NumArgs = ArgsIn.size();
2239       Expr **Args = ArgsIn.data();
2240       assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2241       return Owned(ObjCMessageExpr::Create(Context, Context.DependentTy,
2242                                            VK_RValue, LBracLoc, Receiver, Sel,
2243                                            SelectorLocs, /*Method=*/0,
2244                                            makeArrayRef(Args, NumArgs),
2245                                            RBracLoc, isImplicit));
2246     }
2247 
2248     // If necessary, apply function/array conversion to the receiver.
2249     // C99 6.7.5.3p[7,8].
2250     ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
2251     if (Result.isInvalid())
2252       return ExprError();
2253     Receiver = Result.take();
2254     ReceiverType = Receiver->getType();
2255 
2256     // If the receiver is an ObjC pointer, a block pointer, or an
2257     // __attribute__((NSObject)) pointer, we don't need to do any
2258     // special conversion in order to look up a receiver.
2259     if (ReceiverType->isObjCRetainableType()) {
2260       // do nothing
2261     } else if (!getLangOpts().ObjCAutoRefCount &&
2262                !Context.getObjCIdType().isNull() &&
2263                (ReceiverType->isPointerType() ||
2264                 ReceiverType->isIntegerType())) {
2265       // Implicitly convert integers and pointers to 'id' but emit a warning.
2266       // But not in ARC.
2267       Diag(Loc, diag::warn_bad_receiver_type)
2268         << ReceiverType
2269         << Receiver->getSourceRange();
2270       if (ReceiverType->isPointerType()) {
2271         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2272                                      CK_CPointerToObjCPointerCast).take();
2273       } else {
2274         // TODO: specialized warning on null receivers?
2275         bool IsNull = Receiver->isNullPointerConstant(Context,
2276                                               Expr::NPC_ValueDependentIsNull);
2277         CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
2278         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2279                                      Kind).take();
2280       }
2281       ReceiverType = Receiver->getType();
2282     } else if (getLangOpts().CPlusPlus) {
2283       ExprResult result = PerformContextuallyConvertToObjCPointer(Receiver);
2284       if (result.isUsable()) {
2285         Receiver = result.take();
2286         ReceiverType = Receiver->getType();
2287       }
2288     }
2289   }
2290 
2291   // There's a somewhat weird interaction here where we assume that we
2292   // won't actually have a method unless we also don't need to do some
2293   // of the more detailed type-checking on the receiver.
2294 
2295   if (!Method) {
2296     // Handle messages to id.
2297     bool receiverIsId = ReceiverType->isObjCIdType();
2298     if (receiverIsId || ReceiverType->isBlockPointerType() ||
2299         (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
2300       Method = LookupInstanceMethodInGlobalPool(Sel,
2301                                                 SourceRange(LBracLoc, RBracLoc),
2302                                                 receiverIsId);
2303       if (!Method)
2304         Method = LookupFactoryMethodInGlobalPool(Sel,
2305                                                  SourceRange(LBracLoc,RBracLoc),
2306                                                  receiverIsId);
2307     } else if (ReceiverType->isObjCClassType() ||
2308                ReceiverType->isObjCQualifiedClassType()) {
2309       // Handle messages to Class.
2310       // We allow sending a message to a qualified Class ("Class<foo>"), which
2311       // is ok as long as one of the protocols implements the selector (if not, warn).
2312       if (const ObjCObjectPointerType *QClassTy
2313             = ReceiverType->getAsObjCQualifiedClassType()) {
2314         // Search protocols for class methods.
2315         Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
2316         if (!Method) {
2317           Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
2318           // warn if instance method found for a Class message.
2319           if (Method) {
2320             Diag(SelLoc, diag::warn_instance_method_on_class_found)
2321               << Method->getSelector() << Sel;
2322             Diag(Method->getLocation(), diag::note_method_declared_at)
2323               << Method->getDeclName();
2324           }
2325         }
2326       } else {
2327         if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2328           if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
2329             // First check the public methods in the class interface.
2330             Method = ClassDecl->lookupClassMethod(Sel);
2331 
2332             if (!Method)
2333               Method = ClassDecl->lookupPrivateClassMethod(Sel);
2334           }
2335           if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2336             return ExprError();
2337         }
2338         if (!Method) {
2339           // If not messaging 'self', look for any factory method named 'Sel'.
2340           if (!Receiver || !isSelfExpr(Receiver)) {
2341             Method = LookupFactoryMethodInGlobalPool(Sel,
2342                                                 SourceRange(LBracLoc, RBracLoc),
2343                                                      true);
2344             if (!Method) {
2345               // If no class (factory) method was found, check if an _instance_
2346               // method of the same name exists in the root class only.
2347               Method = LookupInstanceMethodInGlobalPool(Sel,
2348                                                SourceRange(LBracLoc, RBracLoc),
2349                                                         true);
2350               if (Method)
2351                   if (const ObjCInterfaceDecl *ID =
2352                       dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
2353                     if (ID->getSuperClass())
2354                       Diag(SelLoc, diag::warn_root_inst_method_not_found)
2355                       << Sel << SourceRange(LBracLoc, RBracLoc);
2356                   }
2357             }
2358           }
2359         }
2360       }
2361     } else {
2362       ObjCInterfaceDecl* ClassDecl = 0;
2363 
2364       // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
2365       // long as one of the protocols implements the selector (if not, warn).
2366       // And as long as message is not deprecated/unavailable (warn if it is).
2367       if (const ObjCObjectPointerType *QIdTy
2368                                    = ReceiverType->getAsObjCQualifiedIdType()) {
2369         // Search protocols for instance methods.
2370         Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
2371         if (!Method)
2372           Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
2373         if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2374           return ExprError();
2375       } else if (const ObjCObjectPointerType *OCIType
2376                    = ReceiverType->getAsObjCInterfacePointerType()) {
2377         // We allow sending a message to a pointer to an interface (an object).
2378         ClassDecl = OCIType->getInterfaceDecl();
2379 
2380         // Try to complete the type. Under ARC, this is a hard error from which
2381         // we don't try to recover.
2382         const ObjCInterfaceDecl *forwardClass = 0;
2383         if (RequireCompleteType(Loc, OCIType->getPointeeType(),
2384               getLangOpts().ObjCAutoRefCount
2385                 ? diag::err_arc_receiver_forward_instance
2386                 : diag::warn_receiver_forward_instance,
2387                                 Receiver? Receiver->getSourceRange()
2388                                         : SourceRange(SuperLoc))) {
2389           if (getLangOpts().ObjCAutoRefCount)
2390             return ExprError();
2391 
2392           forwardClass = OCIType->getInterfaceDecl();
2393           Diag(Receiver ? Receiver->getLocStart()
2394                         : SuperLoc, diag::note_receiver_is_id);
2395           Method = 0;
2396         } else {
2397           Method = ClassDecl->lookupInstanceMethod(Sel);
2398         }
2399 
2400         if (!Method)
2401           // Search protocol qualifiers.
2402           Method = LookupMethodInQualifiedType(Sel, OCIType, true);
2403 
2404         if (!Method) {
2405           // If we have implementations in scope, check "private" methods.
2406           Method = ClassDecl->lookupPrivateMethod(Sel);
2407 
2408           if (!Method && getLangOpts().ObjCAutoRefCount) {
2409             Diag(SelLoc, diag::err_arc_may_not_respond)
2410               << OCIType->getPointeeType() << Sel << RecRange
2411               << SourceRange(SelectorLocs.front(), SelectorLocs.back());
2412             return ExprError();
2413           }
2414 
2415           if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
2416             // If we still haven't found a method, look in the global pool. This
2417             // behavior isn't very desirable, however we need it for GCC
2418             // compatibility. FIXME: should we deviate??
2419             if (OCIType->qual_empty()) {
2420               Method = LookupInstanceMethodInGlobalPool(Sel,
2421                                               SourceRange(LBracLoc, RBracLoc));
2422               if (Method && !forwardClass)
2423                 Diag(SelLoc, diag::warn_maynot_respond)
2424                   << OCIType->getInterfaceDecl()->getIdentifier()
2425                   << Sel << RecRange;
2426             }
2427           }
2428         }
2429         if (Method && DiagnoseUseOfDecl(Method, SelLoc, forwardClass))
2430           return ExprError();
2431       } else {
2432         // Reject other random receiver types (e.g. structs).
2433         Diag(Loc, diag::err_bad_receiver_type)
2434           << ReceiverType << Receiver->getSourceRange();
2435         return ExprError();
2436       }
2437     }
2438   }
2439 
2440   // Check the message arguments.
2441   unsigned NumArgs = ArgsIn.size();
2442   Expr **Args = ArgsIn.data();
2443   QualType ReturnType;
2444   ExprValueKind VK = VK_RValue;
2445   bool ClassMessage = (ReceiverType->isObjCClassType() ||
2446                        ReceiverType->isObjCQualifiedClassType());
2447   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2448                                 Sel, SelectorLocs, Method,
2449                                 ClassMessage, SuperLoc.isValid(),
2450                                 LBracLoc, RBracLoc, ReturnType, VK))
2451     return ExprError();
2452 
2453   if (Method && !Method->getResultType()->isVoidType() &&
2454       RequireCompleteType(LBracLoc, Method->getResultType(),
2455                           diag::err_illegal_message_expr_incomplete_type))
2456     return ExprError();
2457 
2458   // In ARC, forbid the user from sending messages to
2459   // retain/release/autorelease/dealloc/retainCount explicitly.
2460   if (getLangOpts().ObjCAutoRefCount) {
2461     ObjCMethodFamily family =
2462       (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
2463     switch (family) {
2464     case OMF_init:
2465       if (Method)
2466         checkInitMethod(Method, ReceiverType);
2467 
2468     case OMF_None:
2469     case OMF_alloc:
2470     case OMF_copy:
2471     case OMF_finalize:
2472     case OMF_mutableCopy:
2473     case OMF_new:
2474     case OMF_self:
2475       break;
2476 
2477     case OMF_dealloc:
2478     case OMF_retain:
2479     case OMF_release:
2480     case OMF_autorelease:
2481     case OMF_retainCount:
2482       Diag(SelLoc, diag::err_arc_illegal_explicit_message)
2483         << Sel << RecRange;
2484       break;
2485 
2486     case OMF_performSelector:
2487       if (Method && NumArgs >= 1) {
2488         if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
2489           Selector ArgSel = SelExp->getSelector();
2490           ObjCMethodDecl *SelMethod =
2491             LookupInstanceMethodInGlobalPool(ArgSel,
2492                                              SelExp->getSourceRange());
2493           if (!SelMethod)
2494             SelMethod =
2495               LookupFactoryMethodInGlobalPool(ArgSel,
2496                                               SelExp->getSourceRange());
2497           if (SelMethod) {
2498             ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
2499             switch (SelFamily) {
2500               case OMF_alloc:
2501               case OMF_copy:
2502               case OMF_mutableCopy:
2503               case OMF_new:
2504               case OMF_self:
2505               case OMF_init:
2506                 // Issue error, unless ns_returns_not_retained.
2507                 if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
2508                   // selector names a +1 method
2509                   Diag(SelLoc,
2510                        diag::err_arc_perform_selector_retains);
2511                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2512                     << SelMethod->getDeclName();
2513                 }
2514                 break;
2515               default:
2516                 // +0 call. OK. unless ns_returns_retained.
2517                 if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
2518                   // selector names a +1 method
2519                   Diag(SelLoc,
2520                        diag::err_arc_perform_selector_retains);
2521                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2522                     << SelMethod->getDeclName();
2523                 }
2524                 break;
2525             }
2526           }
2527         } else {
2528           // error (may leak).
2529           Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
2530           Diag(Args[0]->getExprLoc(), diag::note_used_here);
2531         }
2532       }
2533       break;
2534     }
2535   }
2536 
2537   // Construct the appropriate ObjCMessageExpr instance.
2538   ObjCMessageExpr *Result;
2539   if (SuperLoc.isValid())
2540     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2541                                      SuperLoc,  /*IsInstanceSuper=*/true,
2542                                      ReceiverType, Sel, SelectorLocs, Method,
2543                                      makeArrayRef(Args, NumArgs), RBracLoc,
2544                                      isImplicit);
2545   else {
2546     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2547                                      Receiver, Sel, SelectorLocs, Method,
2548                                      makeArrayRef(Args, NumArgs), RBracLoc,
2549                                      isImplicit);
2550     if (!isImplicit)
2551       checkCocoaAPI(*this, Result);
2552   }
2553 
2554   if (getLangOpts().ObjCAutoRefCount) {
2555     DiagnoseARCUseOfWeakReceiver(*this, Receiver);
2556 
2557     // In ARC, annotate delegate init calls.
2558     if (Result->getMethodFamily() == OMF_init &&
2559         (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2560       // Only consider init calls *directly* in init implementations,
2561       // not within blocks.
2562       ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
2563       if (method && method->getMethodFamily() == OMF_init) {
2564         // The implicit assignment to self means we also don't want to
2565         // consume the result.
2566         Result->setDelegateInitCall(true);
2567         return Owned(Result);
2568       }
2569     }
2570 
2571     // In ARC, check for message sends which are likely to introduce
2572     // retain cycles.
2573     checkRetainCycles(Result);
2574 
2575     if (!isImplicit && Method) {
2576       if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
2577         bool IsWeak =
2578           Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
2579         if (!IsWeak && Sel.isUnarySelector())
2580           IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
2581 
2582         if (IsWeak) {
2583           DiagnosticsEngine::Level Level =
2584             Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak,
2585                                      LBracLoc);
2586           if (Level != DiagnosticsEngine::Ignored)
2587             getCurFunction()->recordUseOfWeak(Result, Prop);
2588 
2589         }
2590       }
2591     }
2592   }
2593 
2594   return MaybeBindToTemporary(Result);
2595 }
2596 
RemoveSelectorFromWarningCache(Sema & S,Expr * Arg)2597 static void RemoveSelectorFromWarningCache(Sema &S, Expr* Arg) {
2598   if (ObjCSelectorExpr *OSE =
2599       dyn_cast<ObjCSelectorExpr>(Arg->IgnoreParenCasts())) {
2600     Selector Sel = OSE->getSelector();
2601     SourceLocation Loc = OSE->getAtLoc();
2602     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
2603     = S.ReferencedSelectors.find(Sel);
2604     if (Pos != S.ReferencedSelectors.end() && Pos->second == Loc)
2605       S.ReferencedSelectors.erase(Pos);
2606   }
2607 }
2608 
2609 // ActOnInstanceMessage - used for both unary and keyword messages.
2610 // ArgExprs is optional - if it is present, the number of expressions
2611 // is obtained from Sel.getNumArgs().
ActOnInstanceMessage(Scope * S,Expr * Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2612 ExprResult Sema::ActOnInstanceMessage(Scope *S,
2613                                       Expr *Receiver,
2614                                       Selector Sel,
2615                                       SourceLocation LBracLoc,
2616                                       ArrayRef<SourceLocation> SelectorLocs,
2617                                       SourceLocation RBracLoc,
2618                                       MultiExprArg Args) {
2619   if (!Receiver)
2620     return ExprError();
2621 
2622   // A ParenListExpr can show up while doing error recovery with invalid code.
2623   if (isa<ParenListExpr>(Receiver)) {
2624     ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Receiver);
2625     if (Result.isInvalid()) return ExprError();
2626     Receiver = Result.take();
2627   }
2628 
2629   if (RespondsToSelectorSel.isNull()) {
2630     IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
2631     RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
2632   }
2633   if (Sel == RespondsToSelectorSel)
2634     RemoveSelectorFromWarningCache(*this, Args[0]);
2635 
2636   return BuildInstanceMessage(Receiver, Receiver->getType(),
2637                               /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2638                               LBracLoc, SelectorLocs, RBracLoc, Args);
2639 }
2640 
2641 enum ARCConversionTypeClass {
2642   /// int, void, struct A
2643   ACTC_none,
2644 
2645   /// id, void (^)()
2646   ACTC_retainable,
2647 
2648   /// id*, id***, void (^*)(),
2649   ACTC_indirectRetainable,
2650 
2651   /// void* might be a normal C type, or it might a CF type.
2652   ACTC_voidPtr,
2653 
2654   /// struct A*
2655   ACTC_coreFoundation
2656 };
isAnyRetainable(ARCConversionTypeClass ACTC)2657 static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
2658   return (ACTC == ACTC_retainable ||
2659           ACTC == ACTC_coreFoundation ||
2660           ACTC == ACTC_voidPtr);
2661 }
isAnyCLike(ARCConversionTypeClass ACTC)2662 static bool isAnyCLike(ARCConversionTypeClass ACTC) {
2663   return ACTC == ACTC_none ||
2664          ACTC == ACTC_voidPtr ||
2665          ACTC == ACTC_coreFoundation;
2666 }
2667 
classifyTypeForARCConversion(QualType type)2668 static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
2669   bool isIndirect = false;
2670 
2671   // Ignore an outermost reference type.
2672   if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
2673     type = ref->getPointeeType();
2674     isIndirect = true;
2675   }
2676 
2677   // Drill through pointers and arrays recursively.
2678   while (true) {
2679     if (const PointerType *ptr = type->getAs<PointerType>()) {
2680       type = ptr->getPointeeType();
2681 
2682       // The first level of pointer may be the innermost pointer on a CF type.
2683       if (!isIndirect) {
2684         if (type->isVoidType()) return ACTC_voidPtr;
2685         if (type->isRecordType()) return ACTC_coreFoundation;
2686       }
2687     } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
2688       type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
2689     } else {
2690       break;
2691     }
2692     isIndirect = true;
2693   }
2694 
2695   if (isIndirect) {
2696     if (type->isObjCARCBridgableType())
2697       return ACTC_indirectRetainable;
2698     return ACTC_none;
2699   }
2700 
2701   if (type->isObjCARCBridgableType())
2702     return ACTC_retainable;
2703 
2704   return ACTC_none;
2705 }
2706 
2707 namespace {
2708   /// A result from the cast checker.
2709   enum ACCResult {
2710     /// Cannot be casted.
2711     ACC_invalid,
2712 
2713     /// Can be safely retained or not retained.
2714     ACC_bottom,
2715 
2716     /// Can be casted at +0.
2717     ACC_plusZero,
2718 
2719     /// Can be casted at +1.
2720     ACC_plusOne
2721   };
merge(ACCResult left,ACCResult right)2722   ACCResult merge(ACCResult left, ACCResult right) {
2723     if (left == right) return left;
2724     if (left == ACC_bottom) return right;
2725     if (right == ACC_bottom) return left;
2726     return ACC_invalid;
2727   }
2728 
2729   /// A checker which white-lists certain expressions whose conversion
2730   /// to or from retainable type would otherwise be forbidden in ARC.
2731   class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
2732     typedef StmtVisitor<ARCCastChecker, ACCResult> super;
2733 
2734     ASTContext &Context;
2735     ARCConversionTypeClass SourceClass;
2736     ARCConversionTypeClass TargetClass;
2737     bool Diagnose;
2738 
isCFType(QualType type)2739     static bool isCFType(QualType type) {
2740       // Someday this can use ns_bridged.  For now, it has to do this.
2741       return type->isCARCBridgableType();
2742     }
2743 
2744   public:
ARCCastChecker(ASTContext & Context,ARCConversionTypeClass source,ARCConversionTypeClass target,bool diagnose)2745     ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
2746                    ARCConversionTypeClass target, bool diagnose)
2747       : Context(Context), SourceClass(source), TargetClass(target),
2748         Diagnose(diagnose) {}
2749 
2750     using super::Visit;
Visit(Expr * e)2751     ACCResult Visit(Expr *e) {
2752       return super::Visit(e->IgnoreParens());
2753     }
2754 
VisitStmt(Stmt * s)2755     ACCResult VisitStmt(Stmt *s) {
2756       return ACC_invalid;
2757     }
2758 
2759     /// Null pointer constants can be casted however you please.
VisitExpr(Expr * e)2760     ACCResult VisitExpr(Expr *e) {
2761       if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
2762         return ACC_bottom;
2763       return ACC_invalid;
2764     }
2765 
2766     /// Objective-C string literals can be safely casted.
VisitObjCStringLiteral(ObjCStringLiteral * e)2767     ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
2768       // If we're casting to any retainable type, go ahead.  Global
2769       // strings are immune to retains, so this is bottom.
2770       if (isAnyRetainable(TargetClass)) return ACC_bottom;
2771 
2772       return ACC_invalid;
2773     }
2774 
2775     /// Look through certain implicit and explicit casts.
VisitCastExpr(CastExpr * e)2776     ACCResult VisitCastExpr(CastExpr *e) {
2777       switch (e->getCastKind()) {
2778         case CK_NullToPointer:
2779           return ACC_bottom;
2780 
2781         case CK_NoOp:
2782         case CK_LValueToRValue:
2783         case CK_BitCast:
2784         case CK_CPointerToObjCPointerCast:
2785         case CK_BlockPointerToObjCPointerCast:
2786         case CK_AnyPointerToBlockPointerCast:
2787           return Visit(e->getSubExpr());
2788 
2789         default:
2790           return ACC_invalid;
2791       }
2792     }
2793 
2794     /// Look through unary extension.
VisitUnaryExtension(UnaryOperator * e)2795     ACCResult VisitUnaryExtension(UnaryOperator *e) {
2796       return Visit(e->getSubExpr());
2797     }
2798 
2799     /// Ignore the LHS of a comma operator.
VisitBinComma(BinaryOperator * e)2800     ACCResult VisitBinComma(BinaryOperator *e) {
2801       return Visit(e->getRHS());
2802     }
2803 
2804     /// Conditional operators are okay if both sides are okay.
VisitConditionalOperator(ConditionalOperator * e)2805     ACCResult VisitConditionalOperator(ConditionalOperator *e) {
2806       ACCResult left = Visit(e->getTrueExpr());
2807       if (left == ACC_invalid) return ACC_invalid;
2808       return merge(left, Visit(e->getFalseExpr()));
2809     }
2810 
2811     /// Look through pseudo-objects.
VisitPseudoObjectExpr(PseudoObjectExpr * e)2812     ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
2813       // If we're getting here, we should always have a result.
2814       return Visit(e->getResultExpr());
2815     }
2816 
2817     /// Statement expressions are okay if their result expression is okay.
VisitStmtExpr(StmtExpr * e)2818     ACCResult VisitStmtExpr(StmtExpr *e) {
2819       return Visit(e->getSubStmt()->body_back());
2820     }
2821 
2822     /// Some declaration references are okay.
VisitDeclRefExpr(DeclRefExpr * e)2823     ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
2824       // References to global constants from system headers are okay.
2825       // These are things like 'kCFStringTransformToLatin'.  They are
2826       // can also be assumed to be immune to retains.
2827       VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
2828       if (isAnyRetainable(TargetClass) &&
2829           isAnyRetainable(SourceClass) &&
2830           var &&
2831           var->getStorageClass() == SC_Extern &&
2832           var->getType().isConstQualified() &&
2833           Context.getSourceManager().isInSystemHeader(var->getLocation())) {
2834         return ACC_bottom;
2835       }
2836 
2837       // Nothing else.
2838       return ACC_invalid;
2839     }
2840 
2841     /// Some calls are okay.
VisitCallExpr(CallExpr * e)2842     ACCResult VisitCallExpr(CallExpr *e) {
2843       if (FunctionDecl *fn = e->getDirectCallee())
2844         if (ACCResult result = checkCallToFunction(fn))
2845           return result;
2846 
2847       return super::VisitCallExpr(e);
2848     }
2849 
checkCallToFunction(FunctionDecl * fn)2850     ACCResult checkCallToFunction(FunctionDecl *fn) {
2851       // Require a CF*Ref return type.
2852       if (!isCFType(fn->getResultType()))
2853         return ACC_invalid;
2854 
2855       if (!isAnyRetainable(TargetClass))
2856         return ACC_invalid;
2857 
2858       // Honor an explicit 'not retained' attribute.
2859       if (fn->hasAttr<CFReturnsNotRetainedAttr>())
2860         return ACC_plusZero;
2861 
2862       // Honor an explicit 'retained' attribute, except that for
2863       // now we're not going to permit implicit handling of +1 results,
2864       // because it's a bit frightening.
2865       if (fn->hasAttr<CFReturnsRetainedAttr>())
2866         return Diagnose ? ACC_plusOne
2867                         : ACC_invalid; // ACC_plusOne if we start accepting this
2868 
2869       // Recognize this specific builtin function, which is used by CFSTR.
2870       unsigned builtinID = fn->getBuiltinID();
2871       if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
2872         return ACC_bottom;
2873 
2874       // Otherwise, don't do anything implicit with an unaudited function.
2875       if (!fn->hasAttr<CFAuditedTransferAttr>())
2876         return ACC_invalid;
2877 
2878       // Otherwise, it's +0 unless it follows the create convention.
2879       if (ento::coreFoundation::followsCreateRule(fn))
2880         return Diagnose ? ACC_plusOne
2881                         : ACC_invalid; // ACC_plusOne if we start accepting this
2882 
2883       return ACC_plusZero;
2884     }
2885 
VisitObjCMessageExpr(ObjCMessageExpr * e)2886     ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
2887       return checkCallToMethod(e->getMethodDecl());
2888     }
2889 
VisitObjCPropertyRefExpr(ObjCPropertyRefExpr * e)2890     ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
2891       ObjCMethodDecl *method;
2892       if (e->isExplicitProperty())
2893         method = e->getExplicitProperty()->getGetterMethodDecl();
2894       else
2895         method = e->getImplicitPropertyGetter();
2896       return checkCallToMethod(method);
2897     }
2898 
checkCallToMethod(ObjCMethodDecl * method)2899     ACCResult checkCallToMethod(ObjCMethodDecl *method) {
2900       if (!method) return ACC_invalid;
2901 
2902       // Check for message sends to functions returning CF types.  We
2903       // just obey the Cocoa conventions with these, even though the
2904       // return type is CF.
2905       if (!isAnyRetainable(TargetClass) || !isCFType(method->getResultType()))
2906         return ACC_invalid;
2907 
2908       // If the method is explicitly marked not-retained, it's +0.
2909       if (method->hasAttr<CFReturnsNotRetainedAttr>())
2910         return ACC_plusZero;
2911 
2912       // If the method is explicitly marked as returning retained, or its
2913       // selector follows a +1 Cocoa convention, treat it as +1.
2914       if (method->hasAttr<CFReturnsRetainedAttr>())
2915         return ACC_plusOne;
2916 
2917       switch (method->getSelector().getMethodFamily()) {
2918       case OMF_alloc:
2919       case OMF_copy:
2920       case OMF_mutableCopy:
2921       case OMF_new:
2922         return ACC_plusOne;
2923 
2924       default:
2925         // Otherwise, treat it as +0.
2926         return ACC_plusZero;
2927       }
2928     }
2929   };
2930 }
2931 
isKnownName(StringRef name)2932 bool Sema::isKnownName(StringRef name) {
2933   if (name.empty())
2934     return false;
2935   LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
2936                  Sema::LookupOrdinaryName);
2937   return LookupName(R, TUScope, false);
2938 }
2939 
addFixitForObjCARCConversion(Sema & S,DiagnosticBuilder & DiagB,Sema::CheckedConversionKind CCK,SourceLocation afterLParen,QualType castType,Expr * castExpr,Expr * realCast,const char * bridgeKeyword,const char * CFBridgeName)2940 static void addFixitForObjCARCConversion(Sema &S,
2941                                          DiagnosticBuilder &DiagB,
2942                                          Sema::CheckedConversionKind CCK,
2943                                          SourceLocation afterLParen,
2944                                          QualType castType,
2945                                          Expr *castExpr,
2946                                          Expr *realCast,
2947                                          const char *bridgeKeyword,
2948                                          const char *CFBridgeName) {
2949   // We handle C-style and implicit casts here.
2950   switch (CCK) {
2951   case Sema::CCK_ImplicitConversion:
2952   case Sema::CCK_CStyleCast:
2953   case Sema::CCK_OtherCast:
2954     break;
2955   case Sema::CCK_FunctionalCast:
2956     return;
2957   }
2958 
2959   if (CFBridgeName) {
2960     if (CCK == Sema::CCK_OtherCast) {
2961       if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
2962         SourceRange range(NCE->getOperatorLoc(),
2963                           NCE->getAngleBrackets().getEnd());
2964         SmallString<32> BridgeCall;
2965 
2966         SourceManager &SM = S.getSourceManager();
2967         char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
2968         if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
2969           BridgeCall += ' ';
2970 
2971         BridgeCall += CFBridgeName;
2972         DiagB.AddFixItHint(FixItHint::CreateReplacement(range, BridgeCall));
2973       }
2974       return;
2975     }
2976     Expr *castedE = castExpr;
2977     if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
2978       castedE = CCE->getSubExpr();
2979     castedE = castedE->IgnoreImpCasts();
2980     SourceRange range = castedE->getSourceRange();
2981 
2982     SmallString<32> BridgeCall;
2983 
2984     SourceManager &SM = S.getSourceManager();
2985     char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
2986     if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
2987       BridgeCall += ' ';
2988 
2989     BridgeCall += CFBridgeName;
2990 
2991     if (isa<ParenExpr>(castedE)) {
2992       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2993                          BridgeCall));
2994     } else {
2995       BridgeCall += '(';
2996       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2997                                                     BridgeCall));
2998       DiagB.AddFixItHint(FixItHint::CreateInsertion(
2999                                        S.PP.getLocForEndOfToken(range.getEnd()),
3000                                        ")"));
3001     }
3002     return;
3003   }
3004 
3005   if (CCK == Sema::CCK_CStyleCast) {
3006     DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
3007   } else if (CCK == Sema::CCK_OtherCast) {
3008     if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
3009       std::string castCode = "(";
3010       castCode += bridgeKeyword;
3011       castCode += castType.getAsString();
3012       castCode += ")";
3013       SourceRange Range(NCE->getOperatorLoc(),
3014                         NCE->getAngleBrackets().getEnd());
3015       DiagB.AddFixItHint(FixItHint::CreateReplacement(Range, castCode));
3016     }
3017   } else {
3018     std::string castCode = "(";
3019     castCode += bridgeKeyword;
3020     castCode += castType.getAsString();
3021     castCode += ")";
3022     Expr *castedE = castExpr->IgnoreImpCasts();
3023     SourceRange range = castedE->getSourceRange();
3024     if (isa<ParenExpr>(castedE)) {
3025       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3026                          castCode));
3027     } else {
3028       castCode += "(";
3029       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3030                                                     castCode));
3031       DiagB.AddFixItHint(FixItHint::CreateInsertion(
3032                                        S.PP.getLocForEndOfToken(range.getEnd()),
3033                                        ")"));
3034     }
3035   }
3036 }
3037 
3038 static void
diagnoseObjCARCConversion(Sema & S,SourceRange castRange,QualType castType,ARCConversionTypeClass castACTC,Expr * castExpr,Expr * realCast,ARCConversionTypeClass exprACTC,Sema::CheckedConversionKind CCK)3039 diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
3040                           QualType castType, ARCConversionTypeClass castACTC,
3041                           Expr *castExpr, Expr *realCast,
3042                           ARCConversionTypeClass exprACTC,
3043                           Sema::CheckedConversionKind CCK) {
3044   SourceLocation loc =
3045     (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
3046 
3047   if (S.makeUnavailableInSystemHeader(loc,
3048                 "converts between Objective-C and C pointers in -fobjc-arc"))
3049     return;
3050 
3051   QualType castExprType = castExpr->getType();
3052 
3053   unsigned srcKind = 0;
3054   switch (exprACTC) {
3055   case ACTC_none:
3056   case ACTC_coreFoundation:
3057   case ACTC_voidPtr:
3058     srcKind = (castExprType->isPointerType() ? 1 : 0);
3059     break;
3060   case ACTC_retainable:
3061     srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
3062     break;
3063   case ACTC_indirectRetainable:
3064     srcKind = 4;
3065     break;
3066   }
3067 
3068   // Check whether this could be fixed with a bridge cast.
3069   SourceLocation afterLParen = S.PP.getLocForEndOfToken(castRange.getBegin());
3070   SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
3071 
3072   // Bridge from an ARC type to a CF type.
3073   if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
3074 
3075     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3076       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3077       << 2 // of C pointer type
3078       << castExprType
3079       << unsigned(castType->isBlockPointerType()) // to ObjC|block type
3080       << castType
3081       << castRange
3082       << castExpr->getSourceRange();
3083     bool br = S.isKnownName("CFBridgingRelease");
3084     ACCResult CreateRule =
3085       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3086     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3087     if (CreateRule != ACC_plusOne)
3088     {
3089       DiagnosticBuilder DiagB =
3090         (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3091                               : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3092 
3093       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3094                                    castType, castExpr, realCast, "__bridge ", 0);
3095     }
3096     if (CreateRule != ACC_plusZero)
3097     {
3098       DiagnosticBuilder DiagB =
3099         (CCK == Sema::CCK_OtherCast && !br) ?
3100           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_transfer) << castExprType :
3101           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3102                  diag::note_arc_bridge_transfer)
3103             << castExprType << br;
3104 
3105       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3106                                    castType, castExpr, realCast, "__bridge_transfer ",
3107                                    br ? "CFBridgingRelease" : 0);
3108     }
3109 
3110     return;
3111   }
3112 
3113   // Bridge from a CF type to an ARC type.
3114   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
3115     bool br = S.isKnownName("CFBridgingRetain");
3116     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3117       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3118       << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
3119       << castExprType
3120       << 2 // to C pointer type
3121       << castType
3122       << castRange
3123       << castExpr->getSourceRange();
3124     ACCResult CreateRule =
3125       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3126     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3127     if (CreateRule != ACC_plusOne)
3128     {
3129       DiagnosticBuilder DiagB =
3130       (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3131                                : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3132       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3133                                    castType, castExpr, realCast, "__bridge ", 0);
3134     }
3135     if (CreateRule != ACC_plusZero)
3136     {
3137       DiagnosticBuilder DiagB =
3138         (CCK == Sema::CCK_OtherCast && !br) ?
3139           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_retained) << castType :
3140           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3141                  diag::note_arc_bridge_retained)
3142             << castType << br;
3143 
3144       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3145                                    castType, castExpr, realCast, "__bridge_retained ",
3146                                    br ? "CFBridgingRetain" : 0);
3147     }
3148 
3149     return;
3150   }
3151 
3152   S.Diag(loc, diag::err_arc_mismatched_cast)
3153     << (CCK != Sema::CCK_ImplicitConversion)
3154     << srcKind << castExprType << castType
3155     << castRange << castExpr->getSourceRange();
3156 }
3157 
3158 Sema::ARCConversionResult
CheckObjCARCConversion(SourceRange castRange,QualType castType,Expr * & castExpr,CheckedConversionKind CCK,bool DiagnoseCFAudited)3159 Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
3160                              Expr *&castExpr, CheckedConversionKind CCK,
3161                              bool DiagnoseCFAudited) {
3162   QualType castExprType = castExpr->getType();
3163 
3164   // For the purposes of the classification, we assume reference types
3165   // will bind to temporaries.
3166   QualType effCastType = castType;
3167   if (const ReferenceType *ref = castType->getAs<ReferenceType>())
3168     effCastType = ref->getPointeeType();
3169 
3170   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
3171   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
3172   if (exprACTC == castACTC) {
3173     // check for viablity and report error if casting an rvalue to a
3174     // life-time qualifier.
3175     if ((castACTC == ACTC_retainable) &&
3176         (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
3177         (castType != castExprType)) {
3178       const Type *DT = castType.getTypePtr();
3179       QualType QDT = castType;
3180       // We desugar some types but not others. We ignore those
3181       // that cannot happen in a cast; i.e. auto, and those which
3182       // should not be de-sugared; i.e typedef.
3183       if (const ParenType *PT = dyn_cast<ParenType>(DT))
3184         QDT = PT->desugar();
3185       else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
3186         QDT = TP->desugar();
3187       else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
3188         QDT = AT->desugar();
3189       if (QDT != castType &&
3190           QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
3191         SourceLocation loc =
3192           (castRange.isValid() ? castRange.getBegin()
3193                               : castExpr->getExprLoc());
3194         Diag(loc, diag::err_arc_nolifetime_behavior);
3195       }
3196     }
3197     return ACR_okay;
3198   }
3199 
3200   if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
3201 
3202   // Allow all of these types to be cast to integer types (but not
3203   // vice-versa).
3204   if (castACTC == ACTC_none && castType->isIntegralType(Context))
3205     return ACR_okay;
3206 
3207   // Allow casts between pointers to lifetime types (e.g., __strong id*)
3208   // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
3209   // must be explicit.
3210   if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
3211     return ACR_okay;
3212   if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
3213       CCK != CCK_ImplicitConversion)
3214     return ACR_okay;
3215 
3216   switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
3217   // For invalid casts, fall through.
3218   case ACC_invalid:
3219     break;
3220 
3221   // Do nothing for both bottom and +0.
3222   case ACC_bottom:
3223   case ACC_plusZero:
3224     return ACR_okay;
3225 
3226   // If the result is +1, consume it here.
3227   case ACC_plusOne:
3228     castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
3229                                         CK_ARCConsumeObject, castExpr,
3230                                         0, VK_RValue);
3231     ExprNeedsCleanups = true;
3232     return ACR_okay;
3233   }
3234 
3235   // If this is a non-implicit cast from id or block type to a
3236   // CoreFoundation type, delay complaining in case the cast is used
3237   // in an acceptable context.
3238   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
3239       CCK != CCK_ImplicitConversion)
3240     return ACR_unbridged;
3241 
3242   // Do not issue "bridge cast" diagnostic when implicit casting
3243   // a retainable object to a CF type parameter belonging to an audited
3244   // CF API function. Let caller issue a normal type mismatched diagnostic
3245   // instead.
3246   if (!DiagnoseCFAudited || exprACTC != ACTC_retainable ||
3247       castACTC != ACTC_coreFoundation)
3248     diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3249                               castExpr, castExpr, exprACTC, CCK);
3250   return ACR_okay;
3251 }
3252 
3253 /// Given that we saw an expression with the ARCUnbridgedCastTy
3254 /// placeholder type, complain bitterly.
diagnoseARCUnbridgedCast(Expr * e)3255 void Sema::diagnoseARCUnbridgedCast(Expr *e) {
3256   // We expect the spurious ImplicitCastExpr to already have been stripped.
3257   assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3258   CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
3259 
3260   SourceRange castRange;
3261   QualType castType;
3262   CheckedConversionKind CCK;
3263 
3264   if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
3265     castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
3266     castType = cast->getTypeAsWritten();
3267     CCK = CCK_CStyleCast;
3268   } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
3269     castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
3270     castType = cast->getTypeAsWritten();
3271     CCK = CCK_OtherCast;
3272   } else {
3273     castType = cast->getType();
3274     CCK = CCK_ImplicitConversion;
3275   }
3276 
3277   ARCConversionTypeClass castACTC =
3278     classifyTypeForARCConversion(castType.getNonReferenceType());
3279 
3280   Expr *castExpr = realCast->getSubExpr();
3281   assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
3282 
3283   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3284                             castExpr, realCast, ACTC_retainable, CCK);
3285 }
3286 
3287 /// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
3288 /// type, remove the placeholder cast.
stripARCUnbridgedCast(Expr * e)3289 Expr *Sema::stripARCUnbridgedCast(Expr *e) {
3290   assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3291 
3292   if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
3293     Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
3294     return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
3295   } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
3296     assert(uo->getOpcode() == UO_Extension);
3297     Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
3298     return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
3299                                    sub->getValueKind(), sub->getObjectKind(),
3300                                        uo->getOperatorLoc());
3301   } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
3302     assert(!gse->isResultDependent());
3303 
3304     unsigned n = gse->getNumAssocs();
3305     SmallVector<Expr*, 4> subExprs(n);
3306     SmallVector<TypeSourceInfo*, 4> subTypes(n);
3307     for (unsigned i = 0; i != n; ++i) {
3308       subTypes[i] = gse->getAssocTypeSourceInfo(i);
3309       Expr *sub = gse->getAssocExpr(i);
3310       if (i == gse->getResultIndex())
3311         sub = stripARCUnbridgedCast(sub);
3312       subExprs[i] = sub;
3313     }
3314 
3315     return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
3316                                               gse->getControllingExpr(),
3317                                               subTypes, subExprs,
3318                                               gse->getDefaultLoc(),
3319                                               gse->getRParenLoc(),
3320                                        gse->containsUnexpandedParameterPack(),
3321                                               gse->getResultIndex());
3322   } else {
3323     assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
3324     return cast<ImplicitCastExpr>(e)->getSubExpr();
3325   }
3326 }
3327 
CheckObjCARCUnavailableWeakConversion(QualType castType,QualType exprType)3328 bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
3329                                                  QualType exprType) {
3330   QualType canCastType =
3331     Context.getCanonicalType(castType).getUnqualifiedType();
3332   QualType canExprType =
3333     Context.getCanonicalType(exprType).getUnqualifiedType();
3334   if (isa<ObjCObjectPointerType>(canCastType) &&
3335       castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
3336       canExprType->isObjCObjectPointerType()) {
3337     if (const ObjCObjectPointerType *ObjT =
3338         canExprType->getAs<ObjCObjectPointerType>())
3339       if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
3340         return !ObjI->isArcWeakrefUnavailable();
3341   }
3342   return true;
3343 }
3344 
3345 /// Look for an ObjCReclaimReturnedObject cast and destroy it.
maybeUndoReclaimObject(Expr * e)3346 static Expr *maybeUndoReclaimObject(Expr *e) {
3347   // For now, we just undo operands that are *immediately* reclaim
3348   // expressions, which prevents the vast majority of potential
3349   // problems here.  To catch them all, we'd need to rebuild arbitrary
3350   // value-propagating subexpressions --- we can't reliably rebuild
3351   // in-place because of expression sharing.
3352   if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3353     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
3354       return ice->getSubExpr();
3355 
3356   return e;
3357 }
3358 
BuildObjCBridgedCast(SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,TypeSourceInfo * TSInfo,Expr * SubExpr)3359 ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
3360                                       ObjCBridgeCastKind Kind,
3361                                       SourceLocation BridgeKeywordLoc,
3362                                       TypeSourceInfo *TSInfo,
3363                                       Expr *SubExpr) {
3364   ExprResult SubResult = UsualUnaryConversions(SubExpr);
3365   if (SubResult.isInvalid()) return ExprError();
3366   SubExpr = SubResult.take();
3367 
3368   QualType T = TSInfo->getType();
3369   QualType FromType = SubExpr->getType();
3370 
3371   CastKind CK;
3372 
3373   bool MustConsume = false;
3374   if (T->isDependentType() || SubExpr->isTypeDependent()) {
3375     // Okay: we'll build a dependent expression type.
3376     CK = CK_Dependent;
3377   } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
3378     // Casting CF -> id
3379     CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
3380                                   : CK_CPointerToObjCPointerCast);
3381     switch (Kind) {
3382     case OBC_Bridge:
3383       break;
3384 
3385     case OBC_BridgeRetained: {
3386       bool br = isKnownName("CFBridgingRelease");
3387       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3388         << 2
3389         << FromType
3390         << (T->isBlockPointerType()? 1 : 0)
3391         << T
3392         << SubExpr->getSourceRange()
3393         << Kind;
3394       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3395         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
3396       Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
3397         << FromType << br
3398         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3399                                         br ? "CFBridgingRelease "
3400                                            : "__bridge_transfer ");
3401 
3402       Kind = OBC_Bridge;
3403       break;
3404     }
3405 
3406     case OBC_BridgeTransfer:
3407       // We must consume the Objective-C object produced by the cast.
3408       MustConsume = true;
3409       break;
3410     }
3411   } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
3412     // Okay: id -> CF
3413     CK = CK_BitCast;
3414     switch (Kind) {
3415     case OBC_Bridge:
3416       // Reclaiming a value that's going to be __bridge-casted to CF
3417       // is very dangerous, so we don't do it.
3418       SubExpr = maybeUndoReclaimObject(SubExpr);
3419       break;
3420 
3421     case OBC_BridgeRetained:
3422       // Produce the object before casting it.
3423       SubExpr = ImplicitCastExpr::Create(Context, FromType,
3424                                          CK_ARCProduceObject,
3425                                          SubExpr, 0, VK_RValue);
3426       break;
3427 
3428     case OBC_BridgeTransfer: {
3429       bool br = isKnownName("CFBridgingRetain");
3430       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3431         << (FromType->isBlockPointerType()? 1 : 0)
3432         << FromType
3433         << 2
3434         << T
3435         << SubExpr->getSourceRange()
3436         << Kind;
3437 
3438       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3439         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
3440       Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
3441         << T << br
3442         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3443                           br ? "CFBridgingRetain " : "__bridge_retained");
3444 
3445       Kind = OBC_Bridge;
3446       break;
3447     }
3448     }
3449   } else {
3450     Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
3451       << FromType << T << Kind
3452       << SubExpr->getSourceRange()
3453       << TSInfo->getTypeLoc().getSourceRange();
3454     return ExprError();
3455   }
3456 
3457   Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
3458                                                    BridgeKeywordLoc,
3459                                                    TSInfo, SubExpr);
3460 
3461   if (MustConsume) {
3462     ExprNeedsCleanups = true;
3463     Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
3464                                       0, VK_RValue);
3465   }
3466 
3467   return Result;
3468 }
3469 
ActOnObjCBridgedCast(Scope * S,SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,ParsedType Type,SourceLocation RParenLoc,Expr * SubExpr)3470 ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
3471                                       SourceLocation LParenLoc,
3472                                       ObjCBridgeCastKind Kind,
3473                                       SourceLocation BridgeKeywordLoc,
3474                                       ParsedType Type,
3475                                       SourceLocation RParenLoc,
3476                                       Expr *SubExpr) {
3477   TypeSourceInfo *TSInfo = 0;
3478   QualType T = GetTypeFromParser(Type, &TSInfo);
3479   if (!TSInfo)
3480     TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
3481   return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
3482                               SubExpr);
3483 }
3484