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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/Sema/Lookup.h"
16 #include "clang/Sema/Scope.h"
17 #include "clang/Sema/ScopeInfo.h"
18 #include "clang/Sema/Initialization.h"
19 #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
20 #include "clang/Edit/Rewriters.h"
21 #include "clang/Edit/Commit.h"
22 #include "clang/AST/ASTContext.h"
23 #include "clang/AST/DeclObjC.h"
24 #include "clang/AST/ExprObjC.h"
25 #include "clang/AST/StmtVisitor.h"
26 #include "clang/AST/TypeLoc.h"
27 #include "llvm/ADT/SmallString.h"
28 #include "clang/Lex/Preprocessor.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   llvm::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                                     /*isSynthesized=*/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                                              SC_None, 0);
242     Method->setMethodParams(S.Context, value, ArrayRef<SourceLocation>());
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.getWCharType();
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, 1);
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                                    /*isSynthesized=*/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, SC_None, 0);
493           M->setMethodParams(Context, value, ArrayRef<SourceLocation>());
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.getWCharType();
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                            /*isSynthesized=*/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, SC_None,
660                                                  0);
661       Params.push_back(objects);
662       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
663                                              SourceLocation(),
664                                              SourceLocation(),
665                                              &Context.Idents.get("cnt"),
666                                              Context.UnsignedLongTy,
667                                              /*TInfo=*/0, SC_None, SC_None,
668                                              0);
669       Params.push_back(cnt);
670       Method->setMethodParams(Context, Params, ArrayRef<SourceLocation>());
671     }
672 
673     if (!validateBoxingMethod(*this, SR.getBegin(), NSArrayDecl, Sel, Method))
674       return ExprError();
675 
676     // Dig out the type that all elements should be converted to.
677     QualType T = Method->param_begin()[0]->getType();
678     const PointerType *PtrT = T->getAs<PointerType>();
679     if (!PtrT ||
680         !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
681       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
682         << Sel;
683       Diag(Method->param_begin()[0]->getLocation(),
684            diag::note_objc_literal_method_param)
685         << 0 << T
686         << Context.getPointerType(IdT.withConst());
687       return ExprError();
688     }
689 
690     // Check that the 'count' parameter is integral.
691     if (!Method->param_begin()[1]->getType()->isIntegerType()) {
692       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
693         << Sel;
694       Diag(Method->param_begin()[1]->getLocation(),
695            diag::note_objc_literal_method_param)
696         << 1
697         << Method->param_begin()[1]->getType()
698         << "integral";
699       return ExprError();
700     }
701 
702     // We've found a good +arrayWithObjects:count: method. Save it!
703     ArrayWithObjectsMethod = Method;
704   }
705 
706   QualType ObjectsType = ArrayWithObjectsMethod->param_begin()[0]->getType();
707   QualType RequiredType = ObjectsType->castAs<PointerType>()->getPointeeType();
708 
709   // Check that each of the elements provided is valid in a collection literal,
710   // performing conversions as necessary.
711   Expr **ElementsBuffer = Elements.data();
712   for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
713     ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
714                                                              ElementsBuffer[I],
715                                                              RequiredType);
716     if (Converted.isInvalid())
717       return ExprError();
718 
719     ElementsBuffer[I] = Converted.get();
720   }
721 
722   QualType Ty
723     = Context.getObjCObjectPointerType(
724                                     Context.getObjCInterfaceType(NSArrayDecl));
725 
726   return MaybeBindToTemporary(
727            ObjCArrayLiteral::Create(Context, Elements, Ty,
728                                     ArrayWithObjectsMethod, SR));
729 }
730 
BuildObjCDictionaryLiteral(SourceRange SR,ObjCDictionaryElement * Elements,unsigned NumElements)731 ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
732                                             ObjCDictionaryElement *Elements,
733                                             unsigned NumElements) {
734   // Look up the NSDictionary class, if we haven't done so already.
735   if (!NSDictionaryDecl) {
736     NamedDecl *IF = LookupSingleName(TUScope,
737                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
738                             SR.getBegin(), LookupOrdinaryName);
739     NSDictionaryDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
740     if (!NSDictionaryDecl && getLangOpts().DebuggerObjCLiteral)
741       NSDictionaryDecl =  ObjCInterfaceDecl::Create (Context,
742                             Context.getTranslationUnitDecl(),
743                             SourceLocation(),
744                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
745                             0, SourceLocation());
746 
747     if (!NSDictionaryDecl) {
748       Diag(SR.getBegin(), diag::err_undeclared_nsdictionary);
749       return ExprError();
750     }
751   }
752 
753   // Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
754   // so already.
755   QualType IdT = Context.getObjCIdType();
756   if (!DictionaryWithObjectsMethod) {
757     Selector Sel = NSAPIObj->getNSDictionarySelector(
758                                NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
759     ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
760     if (!Method && getLangOpts().DebuggerObjCLiteral) {
761       Method = ObjCMethodDecl::Create(Context,
762                            SourceLocation(), SourceLocation(), Sel,
763                            IdT,
764                            0 /*TypeSourceInfo */,
765                            Context.getTranslationUnitDecl(),
766                            false /*Instance*/, false/*isVariadic*/,
767                            /*isSynthesized=*/false,
768                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
769                            ObjCMethodDecl::Required,
770                            false);
771       SmallVector<ParmVarDecl *, 3> Params;
772       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
773                                                  SourceLocation(),
774                                                  SourceLocation(),
775                                                  &Context.Idents.get("objects"),
776                                                  Context.getPointerType(IdT),
777                                                  /*TInfo=*/0, SC_None, SC_None,
778                                                  0);
779       Params.push_back(objects);
780       ParmVarDecl *keys = ParmVarDecl::Create(Context, Method,
781                                               SourceLocation(),
782                                               SourceLocation(),
783                                               &Context.Idents.get("keys"),
784                                               Context.getPointerType(IdT),
785                                               /*TInfo=*/0, SC_None, SC_None,
786                                               0);
787       Params.push_back(keys);
788       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
789                                              SourceLocation(),
790                                              SourceLocation(),
791                                              &Context.Idents.get("cnt"),
792                                              Context.UnsignedLongTy,
793                                              /*TInfo=*/0, SC_None, SC_None,
794                                              0);
795       Params.push_back(cnt);
796       Method->setMethodParams(Context, Params, ArrayRef<SourceLocation>());
797     }
798 
799     if (!validateBoxingMethod(*this, SR.getBegin(), NSDictionaryDecl, Sel,
800                               Method))
801        return ExprError();
802 
803     // Dig out the type that all values should be converted to.
804     QualType ValueT = Method->param_begin()[0]->getType();
805     const PointerType *PtrValue = ValueT->getAs<PointerType>();
806     if (!PtrValue ||
807         !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
808       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
809         << Sel;
810       Diag(Method->param_begin()[0]->getLocation(),
811            diag::note_objc_literal_method_param)
812         << 0 << ValueT
813         << Context.getPointerType(IdT.withConst());
814       return ExprError();
815     }
816 
817     // Dig out the type that all keys should be converted to.
818     QualType KeyT = Method->param_begin()[1]->getType();
819     const PointerType *PtrKey = KeyT->getAs<PointerType>();
820     if (!PtrKey ||
821         !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
822                                         IdT)) {
823       bool err = true;
824       if (PtrKey) {
825         if (QIDNSCopying.isNull()) {
826           // key argument of selector is id<NSCopying>?
827           if (ObjCProtocolDecl *NSCopyingPDecl =
828               LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
829             ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
830             QIDNSCopying =
831               Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
832                                         (ObjCProtocolDecl**) PQ,1);
833             QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
834           }
835         }
836         if (!QIDNSCopying.isNull())
837           err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
838                                                 QIDNSCopying);
839       }
840 
841       if (err) {
842         Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
843           << Sel;
844         Diag(Method->param_begin()[1]->getLocation(),
845              diag::note_objc_literal_method_param)
846           << 1 << KeyT
847           << Context.getPointerType(IdT.withConst());
848         return ExprError();
849       }
850     }
851 
852     // Check that the 'count' parameter is integral.
853     QualType CountType = Method->param_begin()[2]->getType();
854     if (!CountType->isIntegerType()) {
855       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
856         << Sel;
857       Diag(Method->param_begin()[2]->getLocation(),
858            diag::note_objc_literal_method_param)
859         << 2 << CountType
860         << "integral";
861       return ExprError();
862     }
863 
864     // We've found a good +dictionaryWithObjects:keys:count: method; save it!
865     DictionaryWithObjectsMethod = Method;
866   }
867 
868   QualType ValuesT = DictionaryWithObjectsMethod->param_begin()[0]->getType();
869   QualType ValueT = ValuesT->castAs<PointerType>()->getPointeeType();
870   QualType KeysT = DictionaryWithObjectsMethod->param_begin()[1]->getType();
871   QualType KeyT = KeysT->castAs<PointerType>()->getPointeeType();
872 
873   // Check that each of the keys and values provided is valid in a collection
874   // literal, performing conversions as necessary.
875   bool HasPackExpansions = false;
876   for (unsigned I = 0, N = NumElements; I != N; ++I) {
877     // Check the key.
878     ExprResult Key = CheckObjCCollectionLiteralElement(*this, Elements[I].Key,
879                                                        KeyT);
880     if (Key.isInvalid())
881       return ExprError();
882 
883     // Check the value.
884     ExprResult Value
885       = CheckObjCCollectionLiteralElement(*this, Elements[I].Value, ValueT);
886     if (Value.isInvalid())
887       return ExprError();
888 
889     Elements[I].Key = Key.get();
890     Elements[I].Value = Value.get();
891 
892     if (Elements[I].EllipsisLoc.isInvalid())
893       continue;
894 
895     if (!Elements[I].Key->containsUnexpandedParameterPack() &&
896         !Elements[I].Value->containsUnexpandedParameterPack()) {
897       Diag(Elements[I].EllipsisLoc,
898            diag::err_pack_expansion_without_parameter_packs)
899         << SourceRange(Elements[I].Key->getLocStart(),
900                        Elements[I].Value->getLocEnd());
901       return ExprError();
902     }
903 
904     HasPackExpansions = true;
905   }
906 
907 
908   QualType Ty
909     = Context.getObjCObjectPointerType(
910                                 Context.getObjCInterfaceType(NSDictionaryDecl));
911   return MaybeBindToTemporary(
912            ObjCDictionaryLiteral::Create(Context,
913                                          llvm::makeArrayRef(Elements,
914                                                             NumElements),
915                                          HasPackExpansions,
916                                          Ty,
917                                          DictionaryWithObjectsMethod, SR));
918 }
919 
BuildObjCEncodeExpression(SourceLocation AtLoc,TypeSourceInfo * EncodedTypeInfo,SourceLocation RParenLoc)920 ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
921                                       TypeSourceInfo *EncodedTypeInfo,
922                                       SourceLocation RParenLoc) {
923   QualType EncodedType = EncodedTypeInfo->getType();
924   QualType StrTy;
925   if (EncodedType->isDependentType())
926     StrTy = Context.DependentTy;
927   else {
928     if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
929         !EncodedType->isVoidType()) // void is handled too.
930       if (RequireCompleteType(AtLoc, EncodedType,
931                               diag::err_incomplete_type_objc_at_encode,
932                               EncodedTypeInfo->getTypeLoc()))
933         return ExprError();
934 
935     std::string Str;
936     Context.getObjCEncodingForType(EncodedType, Str);
937 
938     // The type of @encode is the same as the type of the corresponding string,
939     // which is an array type.
940     StrTy = Context.CharTy;
941     // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
942     if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings)
943       StrTy.addConst();
944     StrTy = Context.getConstantArrayType(StrTy, llvm::APInt(32, Str.size()+1),
945                                          ArrayType::Normal, 0);
946   }
947 
948   return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
949 }
950 
ParseObjCEncodeExpression(SourceLocation AtLoc,SourceLocation EncodeLoc,SourceLocation LParenLoc,ParsedType ty,SourceLocation RParenLoc)951 ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
952                                            SourceLocation EncodeLoc,
953                                            SourceLocation LParenLoc,
954                                            ParsedType ty,
955                                            SourceLocation RParenLoc) {
956   // FIXME: Preserve type source info ?
957   TypeSourceInfo *TInfo;
958   QualType EncodedType = GetTypeFromParser(ty, &TInfo);
959   if (!TInfo)
960     TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
961                                              PP.getLocForEndOfToken(LParenLoc));
962 
963   return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
964 }
965 
ParseObjCSelectorExpression(Selector Sel,SourceLocation AtLoc,SourceLocation SelLoc,SourceLocation LParenLoc,SourceLocation RParenLoc)966 ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
967                                              SourceLocation AtLoc,
968                                              SourceLocation SelLoc,
969                                              SourceLocation LParenLoc,
970                                              SourceLocation RParenLoc) {
971   ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
972                              SourceRange(LParenLoc, RParenLoc), false, false);
973   if (!Method)
974     Method = LookupFactoryMethodInGlobalPool(Sel,
975                                           SourceRange(LParenLoc, RParenLoc));
976   if (!Method)
977     Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
978 
979   if (!Method ||
980       Method->getImplementationControl() != ObjCMethodDecl::Optional) {
981     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
982       = ReferencedSelectors.find(Sel);
983     if (Pos == ReferencedSelectors.end())
984       ReferencedSelectors.insert(std::make_pair(Sel, SelLoc));
985   }
986 
987   // In ARC, forbid the user from using @selector for
988   // retain/release/autorelease/dealloc/retainCount.
989   if (getLangOpts().ObjCAutoRefCount) {
990     switch (Sel.getMethodFamily()) {
991     case OMF_retain:
992     case OMF_release:
993     case OMF_autorelease:
994     case OMF_retainCount:
995     case OMF_dealloc:
996       Diag(AtLoc, diag::err_arc_illegal_selector) <<
997         Sel << SourceRange(LParenLoc, RParenLoc);
998       break;
999 
1000     case OMF_None:
1001     case OMF_alloc:
1002     case OMF_copy:
1003     case OMF_finalize:
1004     case OMF_init:
1005     case OMF_mutableCopy:
1006     case OMF_new:
1007     case OMF_self:
1008     case OMF_performSelector:
1009       break;
1010     }
1011   }
1012   QualType Ty = Context.getObjCSelType();
1013   return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
1014 }
1015 
ParseObjCProtocolExpression(IdentifierInfo * ProtocolId,SourceLocation AtLoc,SourceLocation ProtoLoc,SourceLocation LParenLoc,SourceLocation ProtoIdLoc,SourceLocation RParenLoc)1016 ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
1017                                              SourceLocation AtLoc,
1018                                              SourceLocation ProtoLoc,
1019                                              SourceLocation LParenLoc,
1020                                              SourceLocation ProtoIdLoc,
1021                                              SourceLocation RParenLoc) {
1022   ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoIdLoc);
1023   if (!PDecl) {
1024     Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
1025     return true;
1026   }
1027 
1028   QualType Ty = Context.getObjCProtoType();
1029   if (Ty.isNull())
1030     return true;
1031   Ty = Context.getObjCObjectPointerType(Ty);
1032   return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, ProtoIdLoc, RParenLoc);
1033 }
1034 
1035 /// Try to capture an implicit reference to 'self'.
tryCaptureObjCSelf(SourceLocation Loc)1036 ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
1037   DeclContext *DC = getFunctionLevelDeclContext();
1038 
1039   // If we're not in an ObjC method, error out.  Note that, unlike the
1040   // C++ case, we don't require an instance method --- class methods
1041   // still have a 'self', and we really do still need to capture it!
1042   ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
1043   if (!method)
1044     return 0;
1045 
1046   tryCaptureVariable(method->getSelfDecl(), Loc);
1047 
1048   return method;
1049 }
1050 
stripObjCInstanceType(ASTContext & Context,QualType T)1051 static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
1052   if (T == Context.getObjCInstanceType())
1053     return Context.getObjCIdType();
1054 
1055   return T;
1056 }
1057 
getMessageSendResultType(QualType ReceiverType,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage)1058 QualType Sema::getMessageSendResultType(QualType ReceiverType,
1059                                         ObjCMethodDecl *Method,
1060                                     bool isClassMessage, bool isSuperMessage) {
1061   assert(Method && "Must have a method");
1062   if (!Method->hasRelatedResultType())
1063     return Method->getSendResultType();
1064 
1065   // If a method has a related return type:
1066   //   - if the method found is an instance method, but the message send
1067   //     was a class message send, T is the declared return type of the method
1068   //     found
1069   if (Method->isInstanceMethod() && isClassMessage)
1070     return stripObjCInstanceType(Context, Method->getSendResultType());
1071 
1072   //   - if the receiver is super, T is a pointer to the class of the
1073   //     enclosing method definition
1074   if (isSuperMessage) {
1075     if (ObjCMethodDecl *CurMethod = getCurMethodDecl())
1076       if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface())
1077         return Context.getObjCObjectPointerType(
1078                                         Context.getObjCInterfaceType(Class));
1079   }
1080 
1081   //   - if the receiver is the name of a class U, T is a pointer to U
1082   if (ReceiverType->getAs<ObjCInterfaceType>() ||
1083       ReceiverType->isObjCQualifiedInterfaceType())
1084     return Context.getObjCObjectPointerType(ReceiverType);
1085   //   - if the receiver is of type Class or qualified Class type,
1086   //     T is the declared return type of the method.
1087   if (ReceiverType->isObjCClassType() ||
1088       ReceiverType->isObjCQualifiedClassType())
1089     return stripObjCInstanceType(Context, Method->getSendResultType());
1090 
1091   //   - if the receiver is id, qualified id, Class, or qualified Class, T
1092   //     is the receiver type, otherwise
1093   //   - T is the type of the receiver expression.
1094   return ReceiverType;
1095 }
1096 
EmitRelatedResultTypeNote(const Expr * E)1097 void Sema::EmitRelatedResultTypeNote(const Expr *E) {
1098   E = E->IgnoreParenImpCasts();
1099   const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
1100   if (!MsgSend)
1101     return;
1102 
1103   const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
1104   if (!Method)
1105     return;
1106 
1107   if (!Method->hasRelatedResultType())
1108     return;
1109 
1110   if (Context.hasSameUnqualifiedType(Method->getResultType()
1111                                                         .getNonReferenceType(),
1112                                      MsgSend->getType()))
1113     return;
1114 
1115   if (!Context.hasSameUnqualifiedType(Method->getResultType(),
1116                                       Context.getObjCInstanceType()))
1117     return;
1118 
1119   Diag(Method->getLocation(), diag::note_related_result_type_inferred)
1120     << Method->isInstanceMethod() << Method->getSelector()
1121     << MsgSend->getType();
1122 }
1123 
CheckMessageArgumentTypes(QualType ReceiverType,Expr ** Args,unsigned NumArgs,Selector Sel,ArrayRef<SourceLocation> SelectorLocs,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage,SourceLocation lbrac,SourceLocation rbrac,QualType & ReturnType,ExprValueKind & VK)1124 bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
1125                                      Expr **Args, unsigned NumArgs,
1126                                      Selector Sel,
1127                                      ArrayRef<SourceLocation> SelectorLocs,
1128                                      ObjCMethodDecl *Method,
1129                                      bool isClassMessage, bool isSuperMessage,
1130                                      SourceLocation lbrac, SourceLocation rbrac,
1131                                      QualType &ReturnType, ExprValueKind &VK) {
1132   if (!Method) {
1133     // Apply default argument promotion as for (C99 6.5.2.2p6).
1134     for (unsigned i = 0; i != NumArgs; i++) {
1135       if (Args[i]->isTypeDependent())
1136         continue;
1137 
1138       ExprResult Result = DefaultArgumentPromotion(Args[i]);
1139       if (Result.isInvalid())
1140         return true;
1141       Args[i] = Result.take();
1142     }
1143 
1144     unsigned DiagID;
1145     if (getLangOpts().ObjCAutoRefCount)
1146       DiagID = diag::err_arc_method_not_found;
1147     else
1148       DiagID = isClassMessage ? diag::warn_class_method_not_found
1149                               : diag::warn_inst_method_not_found;
1150     if (!getLangOpts().DebuggerSupport)
1151       Diag(lbrac, DiagID)
1152         << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
1153                                                 SelectorLocs.back());
1154 
1155     // In debuggers, we want to use __unknown_anytype for these
1156     // results so that clients can cast them.
1157     if (getLangOpts().DebuggerSupport) {
1158       ReturnType = Context.UnknownAnyTy;
1159     } else {
1160       ReturnType = Context.getObjCIdType();
1161     }
1162     VK = VK_RValue;
1163     return false;
1164   }
1165 
1166   ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage,
1167                                         isSuperMessage);
1168   VK = Expr::getValueKindForType(Method->getResultType());
1169 
1170   unsigned NumNamedArgs = Sel.getNumArgs();
1171   // Method might have more arguments than selector indicates. This is due
1172   // to addition of c-style arguments in method.
1173   if (Method->param_size() > Sel.getNumArgs())
1174     NumNamedArgs = Method->param_size();
1175   // FIXME. This need be cleaned up.
1176   if (NumArgs < NumNamedArgs) {
1177     Diag(lbrac, diag::err_typecheck_call_too_few_args)
1178       << 2 << NumNamedArgs << NumArgs;
1179     return false;
1180   }
1181 
1182   bool IsError = false;
1183   for (unsigned i = 0; i < NumNamedArgs; i++) {
1184     // We can't do any type-checking on a type-dependent argument.
1185     if (Args[i]->isTypeDependent())
1186       continue;
1187 
1188     Expr *argExpr = Args[i];
1189 
1190     ParmVarDecl *param = Method->param_begin()[i];
1191     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
1192 
1193     // Strip the unbridged-cast placeholder expression off unless it's
1194     // a consumed argument.
1195     if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
1196         !param->hasAttr<CFConsumedAttr>())
1197       argExpr = stripARCUnbridgedCast(argExpr);
1198 
1199     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
1200                             param->getType(),
1201                             diag::err_call_incomplete_argument, argExpr))
1202       return true;
1203 
1204     InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1205                                                                       param);
1206     ExprResult ArgE = PerformCopyInitialization(Entity, lbrac, Owned(argExpr));
1207     if (ArgE.isInvalid())
1208       IsError = true;
1209     else
1210       Args[i] = ArgE.takeAs<Expr>();
1211   }
1212 
1213   // Promote additional arguments to variadic methods.
1214   if (Method->isVariadic()) {
1215     for (unsigned i = NumNamedArgs; i < NumArgs; ++i) {
1216       if (Args[i]->isTypeDependent())
1217         continue;
1218 
1219       ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
1220                                                         0);
1221       IsError |= Arg.isInvalid();
1222       Args[i] = Arg.take();
1223     }
1224   } else {
1225     // Check for extra arguments to non-variadic methods.
1226     if (NumArgs != NumNamedArgs) {
1227       Diag(Args[NumNamedArgs]->getLocStart(),
1228            diag::err_typecheck_call_too_many_args)
1229         << 2 /*method*/ << NumNamedArgs << NumArgs
1230         << Method->getSourceRange()
1231         << SourceRange(Args[NumNamedArgs]->getLocStart(),
1232                        Args[NumArgs-1]->getLocEnd());
1233     }
1234   }
1235 
1236   DiagnoseSentinelCalls(Method, lbrac, Args, NumArgs);
1237 
1238   // Do additional checkings on method.
1239   IsError |= CheckObjCMethodCall(Method, lbrac, Args, NumArgs);
1240 
1241   return IsError;
1242 }
1243 
isSelfExpr(Expr * receiver)1244 bool Sema::isSelfExpr(Expr *receiver) {
1245   // 'self' is objc 'self' in an objc method only.
1246   ObjCMethodDecl *method =
1247     dyn_cast<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
1248   if (!method) return false;
1249 
1250   receiver = receiver->IgnoreParenLValueCasts();
1251   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
1252     if (DRE->getDecl() == method->getSelfDecl())
1253       return true;
1254   return false;
1255 }
1256 
1257 /// LookupMethodInType - Look up a method in an ObjCObjectType.
LookupMethodInObjectType(Selector sel,QualType type,bool isInstance)1258 ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
1259                                                bool isInstance) {
1260   const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
1261   if (ObjCInterfaceDecl *iface = objType->getInterface()) {
1262     // Look it up in the main interface (and categories, etc.)
1263     if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
1264       return method;
1265 
1266     // Okay, look for "private" methods declared in any
1267     // @implementations we've seen.
1268     if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
1269       return method;
1270   }
1271 
1272   // Check qualifiers.
1273   for (ObjCObjectType::qual_iterator
1274          i = objType->qual_begin(), e = objType->qual_end(); i != e; ++i)
1275     if (ObjCMethodDecl *method = (*i)->lookupMethod(sel, isInstance))
1276       return method;
1277 
1278   return 0;
1279 }
1280 
1281 /// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1282 /// list of a qualified objective pointer type.
LookupMethodInQualifiedType(Selector Sel,const ObjCObjectPointerType * OPT,bool Instance)1283 ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
1284                                               const ObjCObjectPointerType *OPT,
1285                                               bool Instance)
1286 {
1287   ObjCMethodDecl *MD = 0;
1288   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1289        E = OPT->qual_end(); I != E; ++I) {
1290     ObjCProtocolDecl *PROTO = (*I);
1291     if ((MD = PROTO->lookupMethod(Sel, Instance))) {
1292       return MD;
1293     }
1294   }
1295   return 0;
1296 }
1297 
DiagnoseARCUseOfWeakReceiver(Sema & S,Expr * Receiver)1298 static void DiagnoseARCUseOfWeakReceiver(Sema &S, Expr *Receiver) {
1299   if (!Receiver)
1300     return;
1301 
1302   if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Receiver))
1303     Receiver = OVE->getSourceExpr();
1304 
1305   Expr *RExpr = Receiver->IgnoreParenImpCasts();
1306   SourceLocation Loc = RExpr->getLocStart();
1307   QualType T = RExpr->getType();
1308   ObjCPropertyDecl *PDecl = 0;
1309   ObjCMethodDecl *GDecl = 0;
1310   if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(RExpr)) {
1311     RExpr = POE->getSyntacticForm();
1312     if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(RExpr)) {
1313       if (PRE->isImplicitProperty()) {
1314         GDecl = PRE->getImplicitPropertyGetter();
1315         if (GDecl) {
1316           T = GDecl->getResultType();
1317         }
1318       }
1319       else {
1320         PDecl = PRE->getExplicitProperty();
1321         if (PDecl) {
1322           T = PDecl->getType();
1323         }
1324       }
1325     }
1326   }
1327   else if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RExpr)) {
1328     // See if receiver is a method which envokes a synthesized getter
1329     // backing a 'weak' property.
1330     ObjCMethodDecl *Method = ME->getMethodDecl();
1331     if (Method && Method->isSynthesized()) {
1332       Selector Sel = Method->getSelector();
1333       if (Sel.getNumArgs() == 0) {
1334         const DeclContext *Container = Method->getDeclContext();
1335         PDecl =
1336           S.LookupPropertyDecl(cast<ObjCContainerDecl>(Container),
1337                                Sel.getIdentifierInfoForSlot(0));
1338       }
1339       if (PDecl)
1340         T = PDecl->getType();
1341     }
1342   }
1343 
1344   if (T.getObjCLifetime() == Qualifiers::OCL_Weak) {
1345     S.Diag(Loc, diag::warn_receiver_is_weak)
1346       << ((!PDecl && !GDecl) ? 0 : (PDecl ? 1 : 2));
1347     if (PDecl)
1348       S.Diag(PDecl->getLocation(), diag::note_property_declare);
1349     else if (GDecl)
1350       S.Diag(GDecl->getLocation(), diag::note_method_declared_at) << GDecl;
1351     return;
1352   }
1353 
1354   if (PDecl &&
1355       (PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak)) {
1356     S.Diag(Loc, diag::warn_receiver_is_weak) << 1;
1357     S.Diag(PDecl->getLocation(), diag::note_property_declare);
1358   }
1359 }
1360 
1361 /// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1362 /// objective C interface.  This is a property reference expression.
1363 ExprResult Sema::
HandleExprPropertyRefExpr(const ObjCObjectPointerType * OPT,Expr * BaseExpr,SourceLocation OpLoc,DeclarationName MemberName,SourceLocation MemberLoc,SourceLocation SuperLoc,QualType SuperType,bool Super)1364 HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
1365                           Expr *BaseExpr, SourceLocation OpLoc,
1366                           DeclarationName MemberName,
1367                           SourceLocation MemberLoc,
1368                           SourceLocation SuperLoc, QualType SuperType,
1369                           bool Super) {
1370   const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
1371   ObjCInterfaceDecl *IFace = IFaceT->getDecl();
1372 
1373   if (!MemberName.isIdentifier()) {
1374     Diag(MemberLoc, diag::err_invalid_property_name)
1375       << MemberName << QualType(OPT, 0);
1376     return ExprError();
1377   }
1378 
1379   IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1380 
1381   SourceRange BaseRange = Super? SourceRange(SuperLoc)
1382                                : BaseExpr->getSourceRange();
1383   if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
1384                           diag::err_property_not_found_forward_class,
1385                           MemberName, BaseRange))
1386     return ExprError();
1387 
1388   // Search for a declared property first.
1389   if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
1390     // Check whether we can reference this property.
1391     if (DiagnoseUseOfDecl(PD, MemberLoc))
1392       return ExprError();
1393     if (Super)
1394       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1395                                                      VK_LValue, OK_ObjCProperty,
1396                                                      MemberLoc,
1397                                                      SuperLoc, SuperType));
1398     else
1399       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1400                                                      VK_LValue, OK_ObjCProperty,
1401                                                      MemberLoc, BaseExpr));
1402   }
1403   // Check protocols on qualified interfaces.
1404   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1405        E = OPT->qual_end(); I != E; ++I)
1406     if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) {
1407       // Check whether we can reference this property.
1408       if (DiagnoseUseOfDecl(PD, MemberLoc))
1409         return ExprError();
1410 
1411       if (Super)
1412         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1413                                                        Context.PseudoObjectTy,
1414                                                        VK_LValue,
1415                                                        OK_ObjCProperty,
1416                                                        MemberLoc,
1417                                                        SuperLoc, SuperType));
1418       else
1419         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1420                                                        Context.PseudoObjectTy,
1421                                                        VK_LValue,
1422                                                        OK_ObjCProperty,
1423                                                        MemberLoc,
1424                                                        BaseExpr));
1425     }
1426   // If that failed, look for an "implicit" property by seeing if the nullary
1427   // selector is implemented.
1428 
1429   // FIXME: The logic for looking up nullary and unary selectors should be
1430   // shared with the code in ActOnInstanceMessage.
1431 
1432   Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
1433   ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
1434 
1435   // May be founf in property's qualified list.
1436   if (!Getter)
1437     Getter = LookupMethodInQualifiedType(Sel, OPT, true);
1438 
1439   // If this reference is in an @implementation, check for 'private' methods.
1440   if (!Getter)
1441     Getter = IFace->lookupPrivateMethod(Sel);
1442 
1443   if (Getter) {
1444     // Check if we can reference this property.
1445     if (DiagnoseUseOfDecl(Getter, MemberLoc))
1446       return ExprError();
1447   }
1448   // If we found a getter then this may be a valid dot-reference, we
1449   // will look for the matching setter, in case it is needed.
1450   Selector SetterSel =
1451     SelectorTable::constructSetterName(PP.getIdentifierTable(),
1452                                        PP.getSelectorTable(), Member);
1453   ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
1454 
1455   // May be founf in property's qualified list.
1456   if (!Setter)
1457     Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
1458 
1459   if (!Setter) {
1460     // If this reference is in an @implementation, also check for 'private'
1461     // methods.
1462     Setter = IFace->lookupPrivateMethod(SetterSel);
1463   }
1464 
1465   if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
1466     return ExprError();
1467 
1468   if (Getter || Setter) {
1469     if (Super)
1470       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1471                                                      Context.PseudoObjectTy,
1472                                                      VK_LValue, OK_ObjCProperty,
1473                                                      MemberLoc,
1474                                                      SuperLoc, SuperType));
1475     else
1476       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1477                                                      Context.PseudoObjectTy,
1478                                                      VK_LValue, OK_ObjCProperty,
1479                                                      MemberLoc, BaseExpr));
1480 
1481   }
1482 
1483   // Attempt to correct for typos in property names.
1484   DeclFilterCCC<ObjCPropertyDecl> Validator;
1485   if (TypoCorrection Corrected = CorrectTypo(
1486       DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName, NULL,
1487       NULL, Validator, IFace, false, OPT)) {
1488     ObjCPropertyDecl *Property =
1489         Corrected.getCorrectionDeclAs<ObjCPropertyDecl>();
1490     DeclarationName TypoResult = Corrected.getCorrection();
1491     Diag(MemberLoc, diag::err_property_not_found_suggest)
1492       << MemberName << QualType(OPT, 0) << TypoResult
1493       << FixItHint::CreateReplacement(MemberLoc, TypoResult.getAsString());
1494     Diag(Property->getLocation(), diag::note_previous_decl)
1495       << Property->getDeclName();
1496     return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
1497                                      TypoResult, MemberLoc,
1498                                      SuperLoc, SuperType, Super);
1499   }
1500   ObjCInterfaceDecl *ClassDeclared;
1501   if (ObjCIvarDecl *Ivar =
1502       IFace->lookupInstanceVariable(Member, ClassDeclared)) {
1503     QualType T = Ivar->getType();
1504     if (const ObjCObjectPointerType * OBJPT =
1505         T->getAsObjCInterfacePointerType()) {
1506       if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
1507                               diag::err_property_not_as_forward_class,
1508                               MemberName, BaseExpr))
1509         return ExprError();
1510     }
1511     Diag(MemberLoc,
1512          diag::err_ivar_access_using_property_syntax_suggest)
1513     << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
1514     << FixItHint::CreateReplacement(OpLoc, "->");
1515     return ExprError();
1516   }
1517 
1518   Diag(MemberLoc, diag::err_property_not_found)
1519     << MemberName << QualType(OPT, 0);
1520   if (Setter)
1521     Diag(Setter->getLocation(), diag::note_getter_unavailable)
1522           << MemberName << BaseExpr->getSourceRange();
1523   return ExprError();
1524 }
1525 
1526 
1527 
1528 ExprResult Sema::
ActOnClassPropertyRefExpr(IdentifierInfo & receiverName,IdentifierInfo & propertyName,SourceLocation receiverNameLoc,SourceLocation propertyNameLoc)1529 ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
1530                           IdentifierInfo &propertyName,
1531                           SourceLocation receiverNameLoc,
1532                           SourceLocation propertyNameLoc) {
1533 
1534   IdentifierInfo *receiverNamePtr = &receiverName;
1535   ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
1536                                                   receiverNameLoc);
1537 
1538   bool IsSuper = false;
1539   if (IFace == 0) {
1540     // If the "receiver" is 'super' in a method, handle it as an expression-like
1541     // property reference.
1542     if (receiverNamePtr->isStr("super")) {
1543       IsSuper = true;
1544 
1545       if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
1546         if (CurMethod->isInstanceMethod()) {
1547           QualType T =
1548             Context.getObjCInterfaceType(CurMethod->getClassInterface());
1549           T = Context.getObjCObjectPointerType(T);
1550 
1551           return HandleExprPropertyRefExpr(T->getAsObjCInterfacePointerType(),
1552                                            /*BaseExpr*/0,
1553                                            SourceLocation()/*OpLoc*/,
1554                                            &propertyName,
1555                                            propertyNameLoc,
1556                                            receiverNameLoc, T, true);
1557         }
1558 
1559         // Otherwise, if this is a class method, try dispatching to our
1560         // superclass.
1561         IFace = CurMethod->getClassInterface()->getSuperClass();
1562       }
1563     }
1564 
1565     if (IFace == 0) {
1566       Diag(receiverNameLoc, diag::err_expected_ident_or_lparen);
1567       return ExprError();
1568     }
1569   }
1570 
1571   // Search for a declared property first.
1572   Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
1573   ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
1574 
1575   // If this reference is in an @implementation, check for 'private' methods.
1576   if (!Getter)
1577     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1578       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1579         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1580           Getter = ImpDecl->getClassMethod(Sel);
1581 
1582   if (Getter) {
1583     // FIXME: refactor/share with ActOnMemberReference().
1584     // Check if we can reference this property.
1585     if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
1586       return ExprError();
1587   }
1588 
1589   // Look for the matching setter, in case it is needed.
1590   Selector SetterSel =
1591     SelectorTable::constructSetterName(PP.getIdentifierTable(),
1592                                        PP.getSelectorTable(), &propertyName);
1593 
1594   ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1595   if (!Setter) {
1596     // If this reference is in an @implementation, also check for 'private'
1597     // methods.
1598     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1599       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1600         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1601           Setter = ImpDecl->getClassMethod(SetterSel);
1602   }
1603   // Look through local category implementations associated with the class.
1604   if (!Setter)
1605     Setter = IFace->getCategoryClassMethod(SetterSel);
1606 
1607   if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
1608     return ExprError();
1609 
1610   if (Getter || Setter) {
1611     if (IsSuper)
1612     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1613                                                    Context.PseudoObjectTy,
1614                                                    VK_LValue, OK_ObjCProperty,
1615                                                    propertyNameLoc,
1616                                                    receiverNameLoc,
1617                                           Context.getObjCInterfaceType(IFace)));
1618 
1619     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1620                                                    Context.PseudoObjectTy,
1621                                                    VK_LValue, OK_ObjCProperty,
1622                                                    propertyNameLoc,
1623                                                    receiverNameLoc, IFace));
1624   }
1625   return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
1626                      << &propertyName << Context.getObjCInterfaceType(IFace));
1627 }
1628 
1629 namespace {
1630 
1631 class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
1632  public:
ObjCInterfaceOrSuperCCC(ObjCMethodDecl * Method)1633   ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
1634     // Determine whether "super" is acceptable in the current context.
1635     if (Method && Method->getClassInterface())
1636       WantObjCSuper = Method->getClassInterface()->getSuperClass();
1637   }
1638 
ValidateCandidate(const TypoCorrection & candidate)1639   virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1640     return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
1641         candidate.isKeyword("super");
1642   }
1643 };
1644 
1645 }
1646 
getObjCMessageKind(Scope * S,IdentifierInfo * Name,SourceLocation NameLoc,bool IsSuper,bool HasTrailingDot,ParsedType & ReceiverType)1647 Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
1648                                                IdentifierInfo *Name,
1649                                                SourceLocation NameLoc,
1650                                                bool IsSuper,
1651                                                bool HasTrailingDot,
1652                                                ParsedType &ReceiverType) {
1653   ReceiverType = ParsedType();
1654 
1655   // If the identifier is "super" and there is no trailing dot, we're
1656   // messaging super. If the identifier is "super" and there is a
1657   // trailing dot, it's an instance message.
1658   if (IsSuper && S->isInObjcMethodScope())
1659     return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
1660 
1661   LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1662   LookupName(Result, S);
1663 
1664   switch (Result.getResultKind()) {
1665   case LookupResult::NotFound:
1666     // Normal name lookup didn't find anything. If we're in an
1667     // Objective-C method, look for ivars. If we find one, we're done!
1668     // FIXME: This is a hack. Ivar lookup should be part of normal
1669     // lookup.
1670     if (ObjCMethodDecl *Method = getCurMethodDecl()) {
1671       if (!Method->getClassInterface()) {
1672         // Fall back: let the parser try to parse it as an instance message.
1673         return ObjCInstanceMessage;
1674       }
1675 
1676       ObjCInterfaceDecl *ClassDeclared;
1677       if (Method->getClassInterface()->lookupInstanceVariable(Name,
1678                                                               ClassDeclared))
1679         return ObjCInstanceMessage;
1680     }
1681 
1682     // Break out; we'll perform typo correction below.
1683     break;
1684 
1685   case LookupResult::NotFoundInCurrentInstantiation:
1686   case LookupResult::FoundOverloaded:
1687   case LookupResult::FoundUnresolvedValue:
1688   case LookupResult::Ambiguous:
1689     Result.suppressDiagnostics();
1690     return ObjCInstanceMessage;
1691 
1692   case LookupResult::Found: {
1693     // If the identifier is a class or not, and there is a trailing dot,
1694     // it's an instance message.
1695     if (HasTrailingDot)
1696       return ObjCInstanceMessage;
1697     // We found something. If it's a type, then we have a class
1698     // message. Otherwise, it's an instance message.
1699     NamedDecl *ND = Result.getFoundDecl();
1700     QualType T;
1701     if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
1702       T = Context.getObjCInterfaceType(Class);
1703     else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND))
1704       T = Context.getTypeDeclType(Type);
1705     else
1706       return ObjCInstanceMessage;
1707 
1708     //  We have a class message, and T is the type we're
1709     //  messaging. Build source-location information for it.
1710     TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1711     ReceiverType = CreateParsedType(T, TSInfo);
1712     return ObjCClassMessage;
1713   }
1714   }
1715 
1716   ObjCInterfaceOrSuperCCC Validator(getCurMethodDecl());
1717   if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(),
1718                                              Result.getLookupKind(), S, NULL,
1719                                              Validator)) {
1720     if (Corrected.isKeyword()) {
1721       // If we've found the keyword "super" (the only keyword that would be
1722       // returned by CorrectTypo), this is a send to super.
1723       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1724         << Name << Corrected.getCorrection()
1725         << FixItHint::CreateReplacement(SourceRange(NameLoc), "super");
1726       return ObjCSuperMessage;
1727     } else if (ObjCInterfaceDecl *Class =
1728                Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1729       // If we found a declaration, correct when it refers to an Objective-C
1730       // class.
1731       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1732         << Name << Corrected.getCorrection()
1733         << FixItHint::CreateReplacement(SourceRange(NameLoc),
1734                                         Class->getNameAsString());
1735       Diag(Class->getLocation(), diag::note_previous_decl)
1736         << Corrected.getCorrection();
1737 
1738       QualType T = Context.getObjCInterfaceType(Class);
1739       TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1740       ReceiverType = CreateParsedType(T, TSInfo);
1741       return ObjCClassMessage;
1742     }
1743   }
1744 
1745   // Fall back: let the parser try to parse it as an instance message.
1746   return ObjCInstanceMessage;
1747 }
1748 
ActOnSuperMessage(Scope * S,SourceLocation SuperLoc,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)1749 ExprResult Sema::ActOnSuperMessage(Scope *S,
1750                                    SourceLocation SuperLoc,
1751                                    Selector Sel,
1752                                    SourceLocation LBracLoc,
1753                                    ArrayRef<SourceLocation> SelectorLocs,
1754                                    SourceLocation RBracLoc,
1755                                    MultiExprArg Args) {
1756   // Determine whether we are inside a method or not.
1757   ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
1758   if (!Method) {
1759     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
1760     return ExprError();
1761   }
1762 
1763   ObjCInterfaceDecl *Class = Method->getClassInterface();
1764   if (!Class) {
1765     Diag(SuperLoc, diag::error_no_super_class_message)
1766       << Method->getDeclName();
1767     return ExprError();
1768   }
1769 
1770   ObjCInterfaceDecl *Super = Class->getSuperClass();
1771   if (!Super) {
1772     // The current class does not have a superclass.
1773     Diag(SuperLoc, diag::error_root_class_cannot_use_super)
1774       << Class->getIdentifier();
1775     return ExprError();
1776   }
1777 
1778   // We are in a method whose class has a superclass, so 'super'
1779   // is acting as a keyword.
1780   if (Method->isInstanceMethod()) {
1781     if (Sel.getMethodFamily() == OMF_dealloc)
1782       getCurFunction()->ObjCShouldCallSuperDealloc = false;
1783     else if (const ObjCMethodDecl *IMD =
1784                Class->lookupMethod(Method->getSelector(),
1785                                    Method->isInstanceMethod()))
1786           // Must check for name of message since the method could
1787           // be another method with objc_requires_super attribute set.
1788           if (IMD->hasAttr<ObjCRequiresSuperAttr>() &&
1789               Sel == IMD->getSelector())
1790             getCurFunction()->ObjCShouldCallSuperDealloc = false;
1791     if (Sel.getMethodFamily() == OMF_finalize)
1792       getCurFunction()->ObjCShouldCallSuperFinalize = false;
1793 
1794     // Since we are in an instance method, this is an instance
1795     // message to the superclass instance.
1796     QualType SuperTy = Context.getObjCInterfaceType(Super);
1797     SuperTy = Context.getObjCObjectPointerType(SuperTy);
1798     return BuildInstanceMessage(0, SuperTy, SuperLoc,
1799                                 Sel, /*Method=*/0,
1800                                 LBracLoc, SelectorLocs, RBracLoc, Args);
1801   }
1802 
1803   // Since we are in a class method, this is a class message to
1804   // the superclass.
1805   return BuildClassMessage(/*ReceiverTypeInfo=*/0,
1806                            Context.getObjCInterfaceType(Super),
1807                            SuperLoc, Sel, /*Method=*/0,
1808                            LBracLoc, SelectorLocs, RBracLoc, Args);
1809 }
1810 
1811 
BuildClassMessageImplicit(QualType ReceiverType,bool isSuperReceiver,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)1812 ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
1813                                            bool isSuperReceiver,
1814                                            SourceLocation Loc,
1815                                            Selector Sel,
1816                                            ObjCMethodDecl *Method,
1817                                            MultiExprArg Args) {
1818   TypeSourceInfo *receiverTypeInfo = 0;
1819   if (!ReceiverType.isNull())
1820     receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
1821 
1822   return BuildClassMessage(receiverTypeInfo, ReceiverType,
1823                           /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
1824                            Sel, Method, Loc, Loc, Loc, Args,
1825                            /*isImplicit=*/true);
1826 
1827 }
1828 
applyCocoaAPICheck(Sema & S,const ObjCMessageExpr * Msg,unsigned DiagID,bool (* refactor)(const ObjCMessageExpr *,const NSAPI &,edit::Commit &))1829 static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
1830                                unsigned DiagID,
1831                                bool (*refactor)(const ObjCMessageExpr *,
1832                                               const NSAPI &, edit::Commit &)) {
1833   SourceLocation MsgLoc = Msg->getExprLoc();
1834   if (S.Diags.getDiagnosticLevel(DiagID, MsgLoc) == DiagnosticsEngine::Ignored)
1835     return;
1836 
1837   SourceManager &SM = S.SourceMgr;
1838   edit::Commit ECommit(SM, S.LangOpts);
1839   if (refactor(Msg,*S.NSAPIObj, ECommit)) {
1840     DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
1841                         << Msg->getSelector() << Msg->getSourceRange();
1842     // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
1843     if (!ECommit.isCommitable())
1844       return;
1845     for (edit::Commit::edit_iterator
1846            I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
1847       const edit::Commit::Edit &Edit = *I;
1848       switch (Edit.Kind) {
1849       case edit::Commit::Act_Insert:
1850         Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
1851                                                         Edit.Text,
1852                                                         Edit.BeforePrev));
1853         break;
1854       case edit::Commit::Act_InsertFromRange:
1855         Builder.AddFixItHint(
1856             FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
1857                                                 Edit.getInsertFromRange(SM),
1858                                                 Edit.BeforePrev));
1859         break;
1860       case edit::Commit::Act_Remove:
1861         Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
1862         break;
1863       }
1864     }
1865   }
1866 }
1867 
checkCocoaAPI(Sema & S,const ObjCMessageExpr * Msg)1868 static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
1869   applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
1870                      edit::rewriteObjCRedundantCallWithLiteral);
1871 }
1872 
1873 /// \brief Build an Objective-C class message expression.
1874 ///
1875 /// This routine takes care of both normal class messages and
1876 /// class messages to the superclass.
1877 ///
1878 /// \param ReceiverTypeInfo Type source information that describes the
1879 /// receiver of this message. This may be NULL, in which case we are
1880 /// sending to the superclass and \p SuperLoc must be a valid source
1881 /// location.
1882 
1883 /// \param ReceiverType The type of the object receiving the
1884 /// message. When \p ReceiverTypeInfo is non-NULL, this is the same
1885 /// type as that refers to. For a superclass send, this is the type of
1886 /// the superclass.
1887 ///
1888 /// \param SuperLoc The location of the "super" keyword in a
1889 /// superclass message.
1890 ///
1891 /// \param Sel The selector to which the message is being sent.
1892 ///
1893 /// \param Method The method that this class message is invoking, if
1894 /// already known.
1895 ///
1896 /// \param LBracLoc The location of the opening square bracket ']'.
1897 ///
1898 /// \param RBracLoc The location of the closing square bracket ']'.
1899 ///
1900 /// \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)1901 ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
1902                                    QualType ReceiverType,
1903                                    SourceLocation SuperLoc,
1904                                    Selector Sel,
1905                                    ObjCMethodDecl *Method,
1906                                    SourceLocation LBracLoc,
1907                                    ArrayRef<SourceLocation> SelectorLocs,
1908                                    SourceLocation RBracLoc,
1909                                    MultiExprArg ArgsIn,
1910                                    bool isImplicit) {
1911   SourceLocation Loc = SuperLoc.isValid()? SuperLoc
1912     : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
1913   if (LBracLoc.isInvalid()) {
1914     Diag(Loc, diag::err_missing_open_square_message_send)
1915       << FixItHint::CreateInsertion(Loc, "[");
1916     LBracLoc = Loc;
1917   }
1918 
1919   if (ReceiverType->isDependentType()) {
1920     // If the receiver type is dependent, we can't type-check anything
1921     // at this point. Build a dependent expression.
1922     unsigned NumArgs = ArgsIn.size();
1923     Expr **Args = ArgsIn.data();
1924     assert(SuperLoc.isInvalid() && "Message to super with dependent type");
1925     return Owned(ObjCMessageExpr::Create(Context, ReceiverType,
1926                                          VK_RValue, LBracLoc, ReceiverTypeInfo,
1927                                          Sel, SelectorLocs, /*Method=*/0,
1928                                          makeArrayRef(Args, NumArgs),RBracLoc,
1929                                          isImplicit));
1930   }
1931 
1932   // Find the class to which we are sending this message.
1933   ObjCInterfaceDecl *Class = 0;
1934   const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
1935   if (!ClassType || !(Class = ClassType->getInterface())) {
1936     Diag(Loc, diag::err_invalid_receiver_class_message)
1937       << ReceiverType;
1938     return ExprError();
1939   }
1940   assert(Class && "We don't know which class we're messaging?");
1941   // objc++ diagnoses during typename annotation.
1942   if (!getLangOpts().CPlusPlus)
1943     (void)DiagnoseUseOfDecl(Class, Loc);
1944   // Find the method we are messaging.
1945   if (!Method) {
1946     SourceRange TypeRange
1947       = SuperLoc.isValid()? SourceRange(SuperLoc)
1948                           : ReceiverTypeInfo->getTypeLoc().getSourceRange();
1949     if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
1950                             (getLangOpts().ObjCAutoRefCount
1951                                ? diag::err_arc_receiver_forward_class
1952                                : diag::warn_receiver_forward_class),
1953                             TypeRange)) {
1954       // A forward class used in messaging is treated as a 'Class'
1955       Method = LookupFactoryMethodInGlobalPool(Sel,
1956                                                SourceRange(LBracLoc, RBracLoc));
1957       if (Method && !getLangOpts().ObjCAutoRefCount)
1958         Diag(Method->getLocation(), diag::note_method_sent_forward_class)
1959           << Method->getDeclName();
1960     }
1961     if (!Method)
1962       Method = Class->lookupClassMethod(Sel);
1963 
1964     // If we have an implementation in scope, check "private" methods.
1965     if (!Method)
1966       Method = Class->lookupPrivateClassMethod(Sel);
1967 
1968     if (Method && DiagnoseUseOfDecl(Method, Loc))
1969       return ExprError();
1970   }
1971 
1972   // Check the argument types and determine the result type.
1973   QualType ReturnType;
1974   ExprValueKind VK = VK_RValue;
1975 
1976   unsigned NumArgs = ArgsIn.size();
1977   Expr **Args = ArgsIn.data();
1978   if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel, SelectorLocs,
1979                                 Method, true,
1980                                 SuperLoc.isValid(), LBracLoc, RBracLoc,
1981                                 ReturnType, VK))
1982     return ExprError();
1983 
1984   if (Method && !Method->getResultType()->isVoidType() &&
1985       RequireCompleteType(LBracLoc, Method->getResultType(),
1986                           diag::err_illegal_message_expr_incomplete_type))
1987     return ExprError();
1988 
1989   // Construct the appropriate ObjCMessageExpr.
1990   ObjCMessageExpr *Result;
1991   if (SuperLoc.isValid())
1992     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
1993                                      SuperLoc, /*IsInstanceSuper=*/false,
1994                                      ReceiverType, Sel, SelectorLocs,
1995                                      Method, makeArrayRef(Args, NumArgs),
1996                                      RBracLoc, isImplicit);
1997   else {
1998     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
1999                                      ReceiverTypeInfo, Sel, SelectorLocs,
2000                                      Method, makeArrayRef(Args, NumArgs),
2001                                      RBracLoc, isImplicit);
2002     if (!isImplicit)
2003       checkCocoaAPI(*this, Result);
2004   }
2005   return MaybeBindToTemporary(Result);
2006 }
2007 
2008 // ActOnClassMessage - used for both unary and keyword messages.
2009 // ArgExprs is optional - if it is present, the number of expressions
2010 // is obtained from Sel.getNumArgs().
ActOnClassMessage(Scope * S,ParsedType Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2011 ExprResult Sema::ActOnClassMessage(Scope *S,
2012                                    ParsedType Receiver,
2013                                    Selector Sel,
2014                                    SourceLocation LBracLoc,
2015                                    ArrayRef<SourceLocation> SelectorLocs,
2016                                    SourceLocation RBracLoc,
2017                                    MultiExprArg Args) {
2018   TypeSourceInfo *ReceiverTypeInfo;
2019   QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
2020   if (ReceiverType.isNull())
2021     return ExprError();
2022 
2023 
2024   if (!ReceiverTypeInfo)
2025     ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
2026 
2027   return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
2028                            /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2029                            LBracLoc, SelectorLocs, RBracLoc, Args);
2030 }
2031 
BuildInstanceMessageImplicit(Expr * Receiver,QualType ReceiverType,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)2032 ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
2033                                               QualType ReceiverType,
2034                                               SourceLocation Loc,
2035                                               Selector Sel,
2036                                               ObjCMethodDecl *Method,
2037                                               MultiExprArg Args) {
2038   return BuildInstanceMessage(Receiver, ReceiverType,
2039                               /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
2040                               Sel, Method, Loc, Loc, Loc, Args,
2041                               /*isImplicit=*/true);
2042 }
2043 
2044 /// \brief Build an Objective-C instance message expression.
2045 ///
2046 /// This routine takes care of both normal instance messages and
2047 /// instance messages to the superclass instance.
2048 ///
2049 /// \param Receiver The expression that computes the object that will
2050 /// receive this message. This may be empty, in which case we are
2051 /// sending to the superclass instance and \p SuperLoc must be a valid
2052 /// source location.
2053 ///
2054 /// \param ReceiverType The (static) type of the object receiving the
2055 /// message. When a \p Receiver expression is provided, this is the
2056 /// same type as that expression. For a superclass instance send, this
2057 /// is a pointer to the type of the superclass.
2058 ///
2059 /// \param SuperLoc The location of the "super" keyword in a
2060 /// superclass instance message.
2061 ///
2062 /// \param Sel The selector to which the message is being sent.
2063 ///
2064 /// \param Method The method that this instance message is invoking, if
2065 /// already known.
2066 ///
2067 /// \param LBracLoc The location of the opening square bracket ']'.
2068 ///
2069 /// \param RBracLoc The location of the closing square bracket ']'.
2070 ///
2071 /// \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)2072 ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
2073                                       QualType ReceiverType,
2074                                       SourceLocation SuperLoc,
2075                                       Selector Sel,
2076                                       ObjCMethodDecl *Method,
2077                                       SourceLocation LBracLoc,
2078                                       ArrayRef<SourceLocation> SelectorLocs,
2079                                       SourceLocation RBracLoc,
2080                                       MultiExprArg ArgsIn,
2081                                       bool isImplicit) {
2082   // The location of the receiver.
2083   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
2084 
2085   if (LBracLoc.isInvalid()) {
2086     Diag(Loc, diag::err_missing_open_square_message_send)
2087       << FixItHint::CreateInsertion(Loc, "[");
2088     LBracLoc = Loc;
2089   }
2090 
2091   // If we have a receiver expression, perform appropriate promotions
2092   // and determine receiver type.
2093   if (Receiver) {
2094     if (Receiver->hasPlaceholderType()) {
2095       ExprResult Result;
2096       if (Receiver->getType() == Context.UnknownAnyTy)
2097         Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
2098       else
2099         Result = CheckPlaceholderExpr(Receiver);
2100       if (Result.isInvalid()) return ExprError();
2101       Receiver = Result.take();
2102     }
2103 
2104     if (Receiver->isTypeDependent()) {
2105       // If the receiver is type-dependent, we can't type-check anything
2106       // at this point. Build a dependent expression.
2107       unsigned NumArgs = ArgsIn.size();
2108       Expr **Args = ArgsIn.data();
2109       assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2110       return Owned(ObjCMessageExpr::Create(Context, Context.DependentTy,
2111                                            VK_RValue, LBracLoc, Receiver, Sel,
2112                                            SelectorLocs, /*Method=*/0,
2113                                            makeArrayRef(Args, NumArgs),
2114                                            RBracLoc, isImplicit));
2115     }
2116 
2117     // If necessary, apply function/array conversion to the receiver.
2118     // C99 6.7.5.3p[7,8].
2119     ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
2120     if (Result.isInvalid())
2121       return ExprError();
2122     Receiver = Result.take();
2123     ReceiverType = Receiver->getType();
2124   }
2125 
2126   if (!Method) {
2127     // Handle messages to id.
2128     bool receiverIsId = ReceiverType->isObjCIdType();
2129     if (receiverIsId || ReceiverType->isBlockPointerType() ||
2130         (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
2131       Method = LookupInstanceMethodInGlobalPool(Sel,
2132                                                 SourceRange(LBracLoc, RBracLoc),
2133                                                 receiverIsId);
2134       if (!Method)
2135         Method = LookupFactoryMethodInGlobalPool(Sel,
2136                                                  SourceRange(LBracLoc,RBracLoc),
2137                                                  receiverIsId);
2138     } else if (ReceiverType->isObjCClassType() ||
2139                ReceiverType->isObjCQualifiedClassType()) {
2140       // Handle messages to Class.
2141       // We allow sending a message to a qualified Class ("Class<foo>"), which
2142       // is ok as long as one of the protocols implements the selector (if not, warn).
2143       if (const ObjCObjectPointerType *QClassTy
2144             = ReceiverType->getAsObjCQualifiedClassType()) {
2145         // Search protocols for class methods.
2146         Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
2147         if (!Method) {
2148           Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
2149           // warn if instance method found for a Class message.
2150           if (Method) {
2151             Diag(Loc, diag::warn_instance_method_on_class_found)
2152               << Method->getSelector() << Sel;
2153             Diag(Method->getLocation(), diag::note_method_declared_at)
2154               << Method->getDeclName();
2155           }
2156         }
2157       } else {
2158         if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2159           if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
2160             // First check the public methods in the class interface.
2161             Method = ClassDecl->lookupClassMethod(Sel);
2162 
2163             if (!Method)
2164               Method = ClassDecl->lookupPrivateClassMethod(Sel);
2165           }
2166           if (Method && DiagnoseUseOfDecl(Method, Loc))
2167             return ExprError();
2168         }
2169         if (!Method) {
2170           // If not messaging 'self', look for any factory method named 'Sel'.
2171           if (!Receiver || !isSelfExpr(Receiver)) {
2172             Method = LookupFactoryMethodInGlobalPool(Sel,
2173                                                 SourceRange(LBracLoc, RBracLoc),
2174                                                      true);
2175             if (!Method) {
2176               // If no class (factory) method was found, check if an _instance_
2177               // method of the same name exists in the root class only.
2178               Method = LookupInstanceMethodInGlobalPool(Sel,
2179                                                SourceRange(LBracLoc, RBracLoc),
2180                                                         true);
2181               if (Method)
2182                   if (const ObjCInterfaceDecl *ID =
2183                       dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
2184                     if (ID->getSuperClass())
2185                       Diag(Loc, diag::warn_root_inst_method_not_found)
2186                       << Sel << SourceRange(LBracLoc, RBracLoc);
2187                   }
2188             }
2189           }
2190         }
2191       }
2192     } else {
2193       ObjCInterfaceDecl* ClassDecl = 0;
2194 
2195       // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
2196       // long as one of the protocols implements the selector (if not, warn).
2197       // And as long as message is not deprecated/unavailable (warn if it is).
2198       if (const ObjCObjectPointerType *QIdTy
2199                                    = ReceiverType->getAsObjCQualifiedIdType()) {
2200         // Search protocols for instance methods.
2201         Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
2202         if (!Method)
2203           Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
2204         if (Method && DiagnoseUseOfDecl(Method, Loc))
2205           return ExprError();
2206       } else if (const ObjCObjectPointerType *OCIType
2207                    = ReceiverType->getAsObjCInterfacePointerType()) {
2208         // We allow sending a message to a pointer to an interface (an object).
2209         ClassDecl = OCIType->getInterfaceDecl();
2210 
2211         // Try to complete the type. Under ARC, this is a hard error from which
2212         // we don't try to recover.
2213         const ObjCInterfaceDecl *forwardClass = 0;
2214         if (RequireCompleteType(Loc, OCIType->getPointeeType(),
2215               getLangOpts().ObjCAutoRefCount
2216                 ? diag::err_arc_receiver_forward_instance
2217                 : diag::warn_receiver_forward_instance,
2218                                 Receiver? Receiver->getSourceRange()
2219                                         : SourceRange(SuperLoc))) {
2220           if (getLangOpts().ObjCAutoRefCount)
2221             return ExprError();
2222 
2223           forwardClass = OCIType->getInterfaceDecl();
2224           Diag(Receiver ? Receiver->getLocStart()
2225                         : SuperLoc, diag::note_receiver_is_id);
2226           Method = 0;
2227         } else {
2228           Method = ClassDecl->lookupInstanceMethod(Sel);
2229         }
2230 
2231         if (!Method)
2232           // Search protocol qualifiers.
2233           Method = LookupMethodInQualifiedType(Sel, OCIType, true);
2234 
2235         if (!Method) {
2236           // If we have implementations in scope, check "private" methods.
2237           Method = ClassDecl->lookupPrivateMethod(Sel);
2238 
2239           if (!Method && getLangOpts().ObjCAutoRefCount) {
2240             Diag(Loc, diag::err_arc_may_not_respond)
2241               << OCIType->getPointeeType() << Sel;
2242             return ExprError();
2243           }
2244 
2245           if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
2246             // If we still haven't found a method, look in the global pool. This
2247             // behavior isn't very desirable, however we need it for GCC
2248             // compatibility. FIXME: should we deviate??
2249             if (OCIType->qual_empty()) {
2250               Method = LookupInstanceMethodInGlobalPool(Sel,
2251                                               SourceRange(LBracLoc, RBracLoc));
2252               if (Method && !forwardClass)
2253                 Diag(Loc, diag::warn_maynot_respond)
2254                   << OCIType->getInterfaceDecl()->getIdentifier() << Sel;
2255             }
2256           }
2257         }
2258         if (Method && DiagnoseUseOfDecl(Method, Loc, forwardClass))
2259           return ExprError();
2260       } else if (!getLangOpts().ObjCAutoRefCount &&
2261                  !Context.getObjCIdType().isNull() &&
2262                  (ReceiverType->isPointerType() ||
2263                   ReceiverType->isIntegerType())) {
2264         // Implicitly convert integers and pointers to 'id' but emit a warning.
2265         // But not in ARC.
2266         Diag(Loc, diag::warn_bad_receiver_type)
2267           << ReceiverType
2268           << Receiver->getSourceRange();
2269         if (ReceiverType->isPointerType())
2270           Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2271                             CK_CPointerToObjCPointerCast).take();
2272         else {
2273           // TODO: specialized warning on null receivers?
2274           bool IsNull = Receiver->isNullPointerConstant(Context,
2275                                               Expr::NPC_ValueDependentIsNull);
2276           CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
2277           Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2278                                        Kind).take();
2279         }
2280         ReceiverType = Receiver->getType();
2281       } else {
2282         ExprResult ReceiverRes;
2283         if (getLangOpts().CPlusPlus)
2284           ReceiverRes = PerformContextuallyConvertToObjCPointer(Receiver);
2285         if (ReceiverRes.isUsable()) {
2286           Receiver = ReceiverRes.take();
2287           return BuildInstanceMessage(Receiver,
2288                                       ReceiverType,
2289                                       SuperLoc,
2290                                       Sel,
2291                                       Method,
2292                                       LBracLoc,
2293                                       SelectorLocs,
2294                                       RBracLoc,
2295                                       ArgsIn);
2296         } else {
2297           // Reject other random receiver types (e.g. structs).
2298           Diag(Loc, diag::err_bad_receiver_type)
2299             << ReceiverType << Receiver->getSourceRange();
2300           return ExprError();
2301         }
2302       }
2303     }
2304   }
2305 
2306   // Check the message arguments.
2307   unsigned NumArgs = ArgsIn.size();
2308   Expr **Args = ArgsIn.data();
2309   QualType ReturnType;
2310   ExprValueKind VK = VK_RValue;
2311   bool ClassMessage = (ReceiverType->isObjCClassType() ||
2312                        ReceiverType->isObjCQualifiedClassType());
2313   if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel,
2314                                 SelectorLocs, Method,
2315                                 ClassMessage, SuperLoc.isValid(),
2316                                 LBracLoc, RBracLoc, ReturnType, VK))
2317     return ExprError();
2318 
2319   if (Method && !Method->getResultType()->isVoidType() &&
2320       RequireCompleteType(LBracLoc, Method->getResultType(),
2321                           diag::err_illegal_message_expr_incomplete_type))
2322     return ExprError();
2323 
2324   SourceLocation SelLoc = SelectorLocs.front();
2325 
2326   // In ARC, forbid the user from sending messages to
2327   // retain/release/autorelease/dealloc/retainCount explicitly.
2328   if (getLangOpts().ObjCAutoRefCount) {
2329     ObjCMethodFamily family =
2330       (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
2331     switch (family) {
2332     case OMF_init:
2333       if (Method)
2334         checkInitMethod(Method, ReceiverType);
2335 
2336     case OMF_None:
2337     case OMF_alloc:
2338     case OMF_copy:
2339     case OMF_finalize:
2340     case OMF_mutableCopy:
2341     case OMF_new:
2342     case OMF_self:
2343       break;
2344 
2345     case OMF_dealloc:
2346     case OMF_retain:
2347     case OMF_release:
2348     case OMF_autorelease:
2349     case OMF_retainCount:
2350       Diag(Loc, diag::err_arc_illegal_explicit_message)
2351         << Sel << SelLoc;
2352       break;
2353 
2354     case OMF_performSelector:
2355       if (Method && NumArgs >= 1) {
2356         if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
2357           Selector ArgSel = SelExp->getSelector();
2358           ObjCMethodDecl *SelMethod =
2359             LookupInstanceMethodInGlobalPool(ArgSel,
2360                                              SelExp->getSourceRange());
2361           if (!SelMethod)
2362             SelMethod =
2363               LookupFactoryMethodInGlobalPool(ArgSel,
2364                                               SelExp->getSourceRange());
2365           if (SelMethod) {
2366             ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
2367             switch (SelFamily) {
2368               case OMF_alloc:
2369               case OMF_copy:
2370               case OMF_mutableCopy:
2371               case OMF_new:
2372               case OMF_self:
2373               case OMF_init:
2374                 // Issue error, unless ns_returns_not_retained.
2375                 if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
2376                   // selector names a +1 method
2377                   Diag(SelLoc,
2378                        diag::err_arc_perform_selector_retains);
2379                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2380                     << SelMethod->getDeclName();
2381                 }
2382                 break;
2383               default:
2384                 // +0 call. OK. unless ns_returns_retained.
2385                 if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
2386                   // selector names a +1 method
2387                   Diag(SelLoc,
2388                        diag::err_arc_perform_selector_retains);
2389                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2390                     << SelMethod->getDeclName();
2391                 }
2392                 break;
2393             }
2394           }
2395         } else {
2396           // error (may leak).
2397           Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
2398           Diag(Args[0]->getExprLoc(), diag::note_used_here);
2399         }
2400       }
2401       break;
2402     }
2403   }
2404 
2405   // Construct the appropriate ObjCMessageExpr instance.
2406   ObjCMessageExpr *Result;
2407   if (SuperLoc.isValid())
2408     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2409                                      SuperLoc,  /*IsInstanceSuper=*/true,
2410                                      ReceiverType, Sel, SelectorLocs, Method,
2411                                      makeArrayRef(Args, NumArgs), RBracLoc,
2412                                      isImplicit);
2413   else {
2414     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2415                                      Receiver, Sel, SelectorLocs, Method,
2416                                      makeArrayRef(Args, NumArgs), RBracLoc,
2417                                      isImplicit);
2418     if (!isImplicit)
2419       checkCocoaAPI(*this, Result);
2420   }
2421 
2422   if (getLangOpts().ObjCAutoRefCount) {
2423     DiagnoseARCUseOfWeakReceiver(*this, Receiver);
2424 
2425     // In ARC, annotate delegate init calls.
2426     if (Result->getMethodFamily() == OMF_init &&
2427         (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2428       // Only consider init calls *directly* in init implementations,
2429       // not within blocks.
2430       ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
2431       if (method && method->getMethodFamily() == OMF_init) {
2432         // The implicit assignment to self means we also don't want to
2433         // consume the result.
2434         Result->setDelegateInitCall(true);
2435         return Owned(Result);
2436       }
2437     }
2438 
2439     // In ARC, check for message sends which are likely to introduce
2440     // retain cycles.
2441     checkRetainCycles(Result);
2442   }
2443 
2444   return MaybeBindToTemporary(Result);
2445 }
2446 
2447 // ActOnInstanceMessage - used for both unary and keyword messages.
2448 // ArgExprs is optional - if it is present, the number of expressions
2449 // is obtained from Sel.getNumArgs().
ActOnInstanceMessage(Scope * S,Expr * Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2450 ExprResult Sema::ActOnInstanceMessage(Scope *S,
2451                                       Expr *Receiver,
2452                                       Selector Sel,
2453                                       SourceLocation LBracLoc,
2454                                       ArrayRef<SourceLocation> SelectorLocs,
2455                                       SourceLocation RBracLoc,
2456                                       MultiExprArg Args) {
2457   if (!Receiver)
2458     return ExprError();
2459 
2460   return BuildInstanceMessage(Receiver, Receiver->getType(),
2461                               /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2462                               LBracLoc, SelectorLocs, RBracLoc, Args);
2463 }
2464 
2465 enum ARCConversionTypeClass {
2466   /// int, void, struct A
2467   ACTC_none,
2468 
2469   /// id, void (^)()
2470   ACTC_retainable,
2471 
2472   /// id*, id***, void (^*)(),
2473   ACTC_indirectRetainable,
2474 
2475   /// void* might be a normal C type, or it might a CF type.
2476   ACTC_voidPtr,
2477 
2478   /// struct A*
2479   ACTC_coreFoundation
2480 };
isAnyRetainable(ARCConversionTypeClass ACTC)2481 static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
2482   return (ACTC == ACTC_retainable ||
2483           ACTC == ACTC_coreFoundation ||
2484           ACTC == ACTC_voidPtr);
2485 }
isAnyCLike(ARCConversionTypeClass ACTC)2486 static bool isAnyCLike(ARCConversionTypeClass ACTC) {
2487   return ACTC == ACTC_none ||
2488          ACTC == ACTC_voidPtr ||
2489          ACTC == ACTC_coreFoundation;
2490 }
2491 
classifyTypeForARCConversion(QualType type)2492 static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
2493   bool isIndirect = false;
2494 
2495   // Ignore an outermost reference type.
2496   if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
2497     type = ref->getPointeeType();
2498     isIndirect = true;
2499   }
2500 
2501   // Drill through pointers and arrays recursively.
2502   while (true) {
2503     if (const PointerType *ptr = type->getAs<PointerType>()) {
2504       type = ptr->getPointeeType();
2505 
2506       // The first level of pointer may be the innermost pointer on a CF type.
2507       if (!isIndirect) {
2508         if (type->isVoidType()) return ACTC_voidPtr;
2509         if (type->isRecordType()) return ACTC_coreFoundation;
2510       }
2511     } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
2512       type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
2513     } else {
2514       break;
2515     }
2516     isIndirect = true;
2517   }
2518 
2519   if (isIndirect) {
2520     if (type->isObjCARCBridgableType())
2521       return ACTC_indirectRetainable;
2522     return ACTC_none;
2523   }
2524 
2525   if (type->isObjCARCBridgableType())
2526     return ACTC_retainable;
2527 
2528   return ACTC_none;
2529 }
2530 
2531 namespace {
2532   /// A result from the cast checker.
2533   enum ACCResult {
2534     /// Cannot be casted.
2535     ACC_invalid,
2536 
2537     /// Can be safely retained or not retained.
2538     ACC_bottom,
2539 
2540     /// Can be casted at +0.
2541     ACC_plusZero,
2542 
2543     /// Can be casted at +1.
2544     ACC_plusOne
2545   };
merge(ACCResult left,ACCResult right)2546   ACCResult merge(ACCResult left, ACCResult right) {
2547     if (left == right) return left;
2548     if (left == ACC_bottom) return right;
2549     if (right == ACC_bottom) return left;
2550     return ACC_invalid;
2551   }
2552 
2553   /// A checker which white-lists certain expressions whose conversion
2554   /// to or from retainable type would otherwise be forbidden in ARC.
2555   class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
2556     typedef StmtVisitor<ARCCastChecker, ACCResult> super;
2557 
2558     ASTContext &Context;
2559     ARCConversionTypeClass SourceClass;
2560     ARCConversionTypeClass TargetClass;
2561     bool Diagnose;
2562 
isCFType(QualType type)2563     static bool isCFType(QualType type) {
2564       // Someday this can use ns_bridged.  For now, it has to do this.
2565       return type->isCARCBridgableType();
2566     }
2567 
2568   public:
ARCCastChecker(ASTContext & Context,ARCConversionTypeClass source,ARCConversionTypeClass target,bool diagnose)2569     ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
2570                    ARCConversionTypeClass target, bool diagnose)
2571       : Context(Context), SourceClass(source), TargetClass(target),
2572         Diagnose(diagnose) {}
2573 
2574     using super::Visit;
Visit(Expr * e)2575     ACCResult Visit(Expr *e) {
2576       return super::Visit(e->IgnoreParens());
2577     }
2578 
VisitStmt(Stmt * s)2579     ACCResult VisitStmt(Stmt *s) {
2580       return ACC_invalid;
2581     }
2582 
2583     /// Null pointer constants can be casted however you please.
VisitExpr(Expr * e)2584     ACCResult VisitExpr(Expr *e) {
2585       if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
2586         return ACC_bottom;
2587       return ACC_invalid;
2588     }
2589 
2590     /// Objective-C string literals can be safely casted.
VisitObjCStringLiteral(ObjCStringLiteral * e)2591     ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
2592       // If we're casting to any retainable type, go ahead.  Global
2593       // strings are immune to retains, so this is bottom.
2594       if (isAnyRetainable(TargetClass)) return ACC_bottom;
2595 
2596       return ACC_invalid;
2597     }
2598 
2599     /// Look through certain implicit and explicit casts.
VisitCastExpr(CastExpr * e)2600     ACCResult VisitCastExpr(CastExpr *e) {
2601       switch (e->getCastKind()) {
2602         case CK_NullToPointer:
2603           return ACC_bottom;
2604 
2605         case CK_NoOp:
2606         case CK_LValueToRValue:
2607         case CK_BitCast:
2608         case CK_CPointerToObjCPointerCast:
2609         case CK_BlockPointerToObjCPointerCast:
2610         case CK_AnyPointerToBlockPointerCast:
2611           return Visit(e->getSubExpr());
2612 
2613         default:
2614           return ACC_invalid;
2615       }
2616     }
2617 
2618     /// Look through unary extension.
VisitUnaryExtension(UnaryOperator * e)2619     ACCResult VisitUnaryExtension(UnaryOperator *e) {
2620       return Visit(e->getSubExpr());
2621     }
2622 
2623     /// Ignore the LHS of a comma operator.
VisitBinComma(BinaryOperator * e)2624     ACCResult VisitBinComma(BinaryOperator *e) {
2625       return Visit(e->getRHS());
2626     }
2627 
2628     /// Conditional operators are okay if both sides are okay.
VisitConditionalOperator(ConditionalOperator * e)2629     ACCResult VisitConditionalOperator(ConditionalOperator *e) {
2630       ACCResult left = Visit(e->getTrueExpr());
2631       if (left == ACC_invalid) return ACC_invalid;
2632       return merge(left, Visit(e->getFalseExpr()));
2633     }
2634 
2635     /// Look through pseudo-objects.
VisitPseudoObjectExpr(PseudoObjectExpr * e)2636     ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
2637       // If we're getting here, we should always have a result.
2638       return Visit(e->getResultExpr());
2639     }
2640 
2641     /// Statement expressions are okay if their result expression is okay.
VisitStmtExpr(StmtExpr * e)2642     ACCResult VisitStmtExpr(StmtExpr *e) {
2643       return Visit(e->getSubStmt()->body_back());
2644     }
2645 
2646     /// Some declaration references are okay.
VisitDeclRefExpr(DeclRefExpr * e)2647     ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
2648       // References to global constants from system headers are okay.
2649       // These are things like 'kCFStringTransformToLatin'.  They are
2650       // can also be assumed to be immune to retains.
2651       VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
2652       if (isAnyRetainable(TargetClass) &&
2653           isAnyRetainable(SourceClass) &&
2654           var &&
2655           var->getStorageClass() == SC_Extern &&
2656           var->getType().isConstQualified() &&
2657           Context.getSourceManager().isInSystemHeader(var->getLocation())) {
2658         return ACC_bottom;
2659       }
2660 
2661       // Nothing else.
2662       return ACC_invalid;
2663     }
2664 
2665     /// Some calls are okay.
VisitCallExpr(CallExpr * e)2666     ACCResult VisitCallExpr(CallExpr *e) {
2667       if (FunctionDecl *fn = e->getDirectCallee())
2668         if (ACCResult result = checkCallToFunction(fn))
2669           return result;
2670 
2671       return super::VisitCallExpr(e);
2672     }
2673 
checkCallToFunction(FunctionDecl * fn)2674     ACCResult checkCallToFunction(FunctionDecl *fn) {
2675       // Require a CF*Ref return type.
2676       if (!isCFType(fn->getResultType()))
2677         return ACC_invalid;
2678 
2679       if (!isAnyRetainable(TargetClass))
2680         return ACC_invalid;
2681 
2682       // Honor an explicit 'not retained' attribute.
2683       if (fn->hasAttr<CFReturnsNotRetainedAttr>())
2684         return ACC_plusZero;
2685 
2686       // Honor an explicit 'retained' attribute, except that for
2687       // now we're not going to permit implicit handling of +1 results,
2688       // because it's a bit frightening.
2689       if (fn->hasAttr<CFReturnsRetainedAttr>())
2690         return Diagnose ? ACC_plusOne
2691                         : ACC_invalid; // ACC_plusOne if we start accepting this
2692 
2693       // Recognize this specific builtin function, which is used by CFSTR.
2694       unsigned builtinID = fn->getBuiltinID();
2695       if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
2696         return ACC_bottom;
2697 
2698       // Otherwise, don't do anything implicit with an unaudited function.
2699       if (!fn->hasAttr<CFAuditedTransferAttr>())
2700         return ACC_invalid;
2701 
2702       // Otherwise, it's +0 unless it follows the create convention.
2703       if (ento::coreFoundation::followsCreateRule(fn))
2704         return Diagnose ? ACC_plusOne
2705                         : ACC_invalid; // ACC_plusOne if we start accepting this
2706 
2707       return ACC_plusZero;
2708     }
2709 
VisitObjCMessageExpr(ObjCMessageExpr * e)2710     ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
2711       return checkCallToMethod(e->getMethodDecl());
2712     }
2713 
VisitObjCPropertyRefExpr(ObjCPropertyRefExpr * e)2714     ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
2715       ObjCMethodDecl *method;
2716       if (e->isExplicitProperty())
2717         method = e->getExplicitProperty()->getGetterMethodDecl();
2718       else
2719         method = e->getImplicitPropertyGetter();
2720       return checkCallToMethod(method);
2721     }
2722 
checkCallToMethod(ObjCMethodDecl * method)2723     ACCResult checkCallToMethod(ObjCMethodDecl *method) {
2724       if (!method) return ACC_invalid;
2725 
2726       // Check for message sends to functions returning CF types.  We
2727       // just obey the Cocoa conventions with these, even though the
2728       // return type is CF.
2729       if (!isAnyRetainable(TargetClass) || !isCFType(method->getResultType()))
2730         return ACC_invalid;
2731 
2732       // If the method is explicitly marked not-retained, it's +0.
2733       if (method->hasAttr<CFReturnsNotRetainedAttr>())
2734         return ACC_plusZero;
2735 
2736       // If the method is explicitly marked as returning retained, or its
2737       // selector follows a +1 Cocoa convention, treat it as +1.
2738       if (method->hasAttr<CFReturnsRetainedAttr>())
2739         return ACC_plusOne;
2740 
2741       switch (method->getSelector().getMethodFamily()) {
2742       case OMF_alloc:
2743       case OMF_copy:
2744       case OMF_mutableCopy:
2745       case OMF_new:
2746         return ACC_plusOne;
2747 
2748       default:
2749         // Otherwise, treat it as +0.
2750         return ACC_plusZero;
2751       }
2752     }
2753   };
2754 }
2755 
isKnownName(StringRef name)2756 bool Sema::isKnownName(StringRef name) {
2757   if (name.empty())
2758     return false;
2759   LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
2760                  Sema::LookupOrdinaryName);
2761   return LookupName(R, TUScope, false);
2762 }
2763 
addFixitForObjCARCConversion(Sema & S,DiagnosticBuilder & DiagB,Sema::CheckedConversionKind CCK,SourceLocation afterLParen,QualType castType,Expr * castExpr,const char * bridgeKeyword,const char * CFBridgeName)2764 static void addFixitForObjCARCConversion(Sema &S,
2765                                          DiagnosticBuilder &DiagB,
2766                                          Sema::CheckedConversionKind CCK,
2767                                          SourceLocation afterLParen,
2768                                          QualType castType,
2769                                          Expr *castExpr,
2770                                          const char *bridgeKeyword,
2771                                          const char *CFBridgeName) {
2772   // We handle C-style and implicit casts here.
2773   switch (CCK) {
2774   case Sema::CCK_ImplicitConversion:
2775   case Sema::CCK_CStyleCast:
2776     break;
2777   case Sema::CCK_FunctionalCast:
2778   case Sema::CCK_OtherCast:
2779     return;
2780   }
2781 
2782   if (CFBridgeName) {
2783     Expr *castedE = castExpr;
2784     if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
2785       castedE = CCE->getSubExpr();
2786     castedE = castedE->IgnoreImpCasts();
2787     SourceRange range = castedE->getSourceRange();
2788 
2789     SmallString<32> BridgeCall;
2790 
2791     SourceManager &SM = S.getSourceManager();
2792     char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
2793     if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
2794       BridgeCall += ' ';
2795 
2796     BridgeCall += CFBridgeName;
2797 
2798     if (isa<ParenExpr>(castedE)) {
2799       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2800                          BridgeCall));
2801     } else {
2802       BridgeCall += '(';
2803       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2804                                                     BridgeCall));
2805       DiagB.AddFixItHint(FixItHint::CreateInsertion(
2806                                        S.PP.getLocForEndOfToken(range.getEnd()),
2807                                        ")"));
2808     }
2809     return;
2810   }
2811 
2812   if (CCK == Sema::CCK_CStyleCast) {
2813     DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
2814   } else {
2815     std::string castCode = "(";
2816     castCode += bridgeKeyword;
2817     castCode += castType.getAsString();
2818     castCode += ")";
2819     Expr *castedE = castExpr->IgnoreImpCasts();
2820     SourceRange range = castedE->getSourceRange();
2821     if (isa<ParenExpr>(castedE)) {
2822       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2823                          castCode));
2824     } else {
2825       castCode += "(";
2826       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2827                                                     castCode));
2828       DiagB.AddFixItHint(FixItHint::CreateInsertion(
2829                                        S.PP.getLocForEndOfToken(range.getEnd()),
2830                                        ")"));
2831     }
2832   }
2833 }
2834 
2835 static void
diagnoseObjCARCConversion(Sema & S,SourceRange castRange,QualType castType,ARCConversionTypeClass castACTC,Expr * castExpr,ARCConversionTypeClass exprACTC,Sema::CheckedConversionKind CCK)2836 diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
2837                           QualType castType, ARCConversionTypeClass castACTC,
2838                           Expr *castExpr, ARCConversionTypeClass exprACTC,
2839                           Sema::CheckedConversionKind CCK) {
2840   SourceLocation loc =
2841     (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
2842 
2843   if (S.makeUnavailableInSystemHeader(loc,
2844                 "converts between Objective-C and C pointers in -fobjc-arc"))
2845     return;
2846 
2847   QualType castExprType = castExpr->getType();
2848 
2849   unsigned srcKind = 0;
2850   switch (exprACTC) {
2851   case ACTC_none:
2852   case ACTC_coreFoundation:
2853   case ACTC_voidPtr:
2854     srcKind = (castExprType->isPointerType() ? 1 : 0);
2855     break;
2856   case ACTC_retainable:
2857     srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
2858     break;
2859   case ACTC_indirectRetainable:
2860     srcKind = 4;
2861     break;
2862   }
2863 
2864   // Check whether this could be fixed with a bridge cast.
2865   SourceLocation afterLParen = S.PP.getLocForEndOfToken(castRange.getBegin());
2866   SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
2867 
2868   // Bridge from an ARC type to a CF type.
2869   if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
2870 
2871     S.Diag(loc, diag::err_arc_cast_requires_bridge)
2872       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
2873       << 2 // of C pointer type
2874       << castExprType
2875       << unsigned(castType->isBlockPointerType()) // to ObjC|block type
2876       << castType
2877       << castRange
2878       << castExpr->getSourceRange();
2879     bool br = S.isKnownName("CFBridgingRelease");
2880     ACCResult CreateRule =
2881       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
2882     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
2883     if (CreateRule != ACC_plusOne)
2884     {
2885       DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge);
2886       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2887                                    castType, castExpr, "__bridge ", 0);
2888     }
2889     if (CreateRule != ACC_plusZero)
2890     {
2891       DiagnosticBuilder DiagB = S.Diag(br ? castExpr->getExprLoc() : noteLoc,
2892                                        diag::note_arc_bridge_transfer)
2893         << castExprType << br;
2894       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2895                                    castType, castExpr, "__bridge_transfer ",
2896                                    br ? "CFBridgingRelease" : 0);
2897     }
2898 
2899     return;
2900   }
2901 
2902   // Bridge from a CF type to an ARC type.
2903   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
2904     bool br = S.isKnownName("CFBridgingRetain");
2905     S.Diag(loc, diag::err_arc_cast_requires_bridge)
2906       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
2907       << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
2908       << castExprType
2909       << 2 // to C pointer type
2910       << castType
2911       << castRange
2912       << castExpr->getSourceRange();
2913     ACCResult CreateRule =
2914       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
2915     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
2916     if (CreateRule != ACC_plusOne)
2917     {
2918       DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge);
2919       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2920                                    castType, castExpr, "__bridge ", 0);
2921     }
2922     if (CreateRule != ACC_plusZero)
2923     {
2924       DiagnosticBuilder DiagB = S.Diag(br ? castExpr->getExprLoc() : noteLoc,
2925                                        diag::note_arc_bridge_retained)
2926         << castType << br;
2927       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2928                                    castType, castExpr, "__bridge_retained ",
2929                                    br ? "CFBridgingRetain" : 0);
2930     }
2931 
2932     return;
2933   }
2934 
2935   S.Diag(loc, diag::err_arc_mismatched_cast)
2936     << (CCK != Sema::CCK_ImplicitConversion)
2937     << srcKind << castExprType << castType
2938     << castRange << castExpr->getSourceRange();
2939 }
2940 
2941 Sema::ARCConversionResult
CheckObjCARCConversion(SourceRange castRange,QualType castType,Expr * & castExpr,CheckedConversionKind CCK)2942 Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
2943                              Expr *&castExpr, CheckedConversionKind CCK) {
2944   QualType castExprType = castExpr->getType();
2945 
2946   // For the purposes of the classification, we assume reference types
2947   // will bind to temporaries.
2948   QualType effCastType = castType;
2949   if (const ReferenceType *ref = castType->getAs<ReferenceType>())
2950     effCastType = ref->getPointeeType();
2951 
2952   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
2953   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
2954   if (exprACTC == castACTC) {
2955     // check for viablity and report error if casting an rvalue to a
2956     // life-time qualifier.
2957     if ((castACTC == ACTC_retainable) &&
2958         (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
2959         (castType != castExprType)) {
2960       const Type *DT = castType.getTypePtr();
2961       QualType QDT = castType;
2962       // We desugar some types but not others. We ignore those
2963       // that cannot happen in a cast; i.e. auto, and those which
2964       // should not be de-sugared; i.e typedef.
2965       if (const ParenType *PT = dyn_cast<ParenType>(DT))
2966         QDT = PT->desugar();
2967       else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
2968         QDT = TP->desugar();
2969       else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
2970         QDT = AT->desugar();
2971       if (QDT != castType &&
2972           QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
2973         SourceLocation loc =
2974           (castRange.isValid() ? castRange.getBegin()
2975                               : castExpr->getExprLoc());
2976         Diag(loc, diag::err_arc_nolifetime_behavior);
2977       }
2978     }
2979     return ACR_okay;
2980   }
2981 
2982   if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
2983 
2984   // Allow all of these types to be cast to integer types (but not
2985   // vice-versa).
2986   if (castACTC == ACTC_none && castType->isIntegralType(Context))
2987     return ACR_okay;
2988 
2989   // Allow casts between pointers to lifetime types (e.g., __strong id*)
2990   // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
2991   // must be explicit.
2992   if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
2993     return ACR_okay;
2994   if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
2995       CCK != CCK_ImplicitConversion)
2996     return ACR_okay;
2997 
2998   switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
2999   // For invalid casts, fall through.
3000   case ACC_invalid:
3001     break;
3002 
3003   // Do nothing for both bottom and +0.
3004   case ACC_bottom:
3005   case ACC_plusZero:
3006     return ACR_okay;
3007 
3008   // If the result is +1, consume it here.
3009   case ACC_plusOne:
3010     castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
3011                                         CK_ARCConsumeObject, castExpr,
3012                                         0, VK_RValue);
3013     ExprNeedsCleanups = true;
3014     return ACR_okay;
3015   }
3016 
3017   // If this is a non-implicit cast from id or block type to a
3018   // CoreFoundation type, delay complaining in case the cast is used
3019   // in an acceptable context.
3020   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
3021       CCK != CCK_ImplicitConversion)
3022     return ACR_unbridged;
3023 
3024   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3025                             castExpr, exprACTC, CCK);
3026   return ACR_okay;
3027 }
3028 
3029 /// Given that we saw an expression with the ARCUnbridgedCastTy
3030 /// placeholder type, complain bitterly.
diagnoseARCUnbridgedCast(Expr * e)3031 void Sema::diagnoseARCUnbridgedCast(Expr *e) {
3032   // We expect the spurious ImplicitCastExpr to already have been stripped.
3033   assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3034   CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
3035 
3036   SourceRange castRange;
3037   QualType castType;
3038   CheckedConversionKind CCK;
3039 
3040   if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
3041     castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
3042     castType = cast->getTypeAsWritten();
3043     CCK = CCK_CStyleCast;
3044   } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
3045     castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
3046     castType = cast->getTypeAsWritten();
3047     CCK = CCK_OtherCast;
3048   } else {
3049     castType = cast->getType();
3050     CCK = CCK_ImplicitConversion;
3051   }
3052 
3053   ARCConversionTypeClass castACTC =
3054     classifyTypeForARCConversion(castType.getNonReferenceType());
3055 
3056   Expr *castExpr = realCast->getSubExpr();
3057   assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
3058 
3059   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3060                             castExpr, ACTC_retainable, CCK);
3061 }
3062 
3063 /// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
3064 /// type, remove the placeholder cast.
stripARCUnbridgedCast(Expr * e)3065 Expr *Sema::stripARCUnbridgedCast(Expr *e) {
3066   assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3067 
3068   if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
3069     Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
3070     return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
3071   } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
3072     assert(uo->getOpcode() == UO_Extension);
3073     Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
3074     return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
3075                                    sub->getValueKind(), sub->getObjectKind(),
3076                                        uo->getOperatorLoc());
3077   } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
3078     assert(!gse->isResultDependent());
3079 
3080     unsigned n = gse->getNumAssocs();
3081     SmallVector<Expr*, 4> subExprs(n);
3082     SmallVector<TypeSourceInfo*, 4> subTypes(n);
3083     for (unsigned i = 0; i != n; ++i) {
3084       subTypes[i] = gse->getAssocTypeSourceInfo(i);
3085       Expr *sub = gse->getAssocExpr(i);
3086       if (i == gse->getResultIndex())
3087         sub = stripARCUnbridgedCast(sub);
3088       subExprs[i] = sub;
3089     }
3090 
3091     return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
3092                                               gse->getControllingExpr(),
3093                                               subTypes, subExprs,
3094                                               gse->getDefaultLoc(),
3095                                               gse->getRParenLoc(),
3096                                        gse->containsUnexpandedParameterPack(),
3097                                               gse->getResultIndex());
3098   } else {
3099     assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
3100     return cast<ImplicitCastExpr>(e)->getSubExpr();
3101   }
3102 }
3103 
CheckObjCARCUnavailableWeakConversion(QualType castType,QualType exprType)3104 bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
3105                                                  QualType exprType) {
3106   QualType canCastType =
3107     Context.getCanonicalType(castType).getUnqualifiedType();
3108   QualType canExprType =
3109     Context.getCanonicalType(exprType).getUnqualifiedType();
3110   if (isa<ObjCObjectPointerType>(canCastType) &&
3111       castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
3112       canExprType->isObjCObjectPointerType()) {
3113     if (const ObjCObjectPointerType *ObjT =
3114         canExprType->getAs<ObjCObjectPointerType>())
3115       if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
3116         return !ObjI->isArcWeakrefUnavailable();
3117   }
3118   return true;
3119 }
3120 
3121 /// Look for an ObjCReclaimReturnedObject cast and destroy it.
maybeUndoReclaimObject(Expr * e)3122 static Expr *maybeUndoReclaimObject(Expr *e) {
3123   // For now, we just undo operands that are *immediately* reclaim
3124   // expressions, which prevents the vast majority of potential
3125   // problems here.  To catch them all, we'd need to rebuild arbitrary
3126   // value-propagating subexpressions --- we can't reliably rebuild
3127   // in-place because of expression sharing.
3128   if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3129     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
3130       return ice->getSubExpr();
3131 
3132   return e;
3133 }
3134 
BuildObjCBridgedCast(SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,TypeSourceInfo * TSInfo,Expr * SubExpr)3135 ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
3136                                       ObjCBridgeCastKind Kind,
3137                                       SourceLocation BridgeKeywordLoc,
3138                                       TypeSourceInfo *TSInfo,
3139                                       Expr *SubExpr) {
3140   ExprResult SubResult = UsualUnaryConversions(SubExpr);
3141   if (SubResult.isInvalid()) return ExprError();
3142   SubExpr = SubResult.take();
3143 
3144   QualType T = TSInfo->getType();
3145   QualType FromType = SubExpr->getType();
3146 
3147   CastKind CK;
3148 
3149   bool MustConsume = false;
3150   if (T->isDependentType() || SubExpr->isTypeDependent()) {
3151     // Okay: we'll build a dependent expression type.
3152     CK = CK_Dependent;
3153   } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
3154     // Casting CF -> id
3155     CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
3156                                   : CK_CPointerToObjCPointerCast);
3157     switch (Kind) {
3158     case OBC_Bridge:
3159       break;
3160 
3161     case OBC_BridgeRetained: {
3162       bool br = isKnownName("CFBridgingRelease");
3163       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3164         << 2
3165         << FromType
3166         << (T->isBlockPointerType()? 1 : 0)
3167         << T
3168         << SubExpr->getSourceRange()
3169         << Kind;
3170       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3171         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
3172       Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
3173         << FromType << br
3174         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3175                                         br ? "CFBridgingRelease "
3176                                            : "__bridge_transfer ");
3177 
3178       Kind = OBC_Bridge;
3179       break;
3180     }
3181 
3182     case OBC_BridgeTransfer:
3183       // We must consume the Objective-C object produced by the cast.
3184       MustConsume = true;
3185       break;
3186     }
3187   } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
3188     // Okay: id -> CF
3189     CK = CK_BitCast;
3190     switch (Kind) {
3191     case OBC_Bridge:
3192       // Reclaiming a value that's going to be __bridge-casted to CF
3193       // is very dangerous, so we don't do it.
3194       SubExpr = maybeUndoReclaimObject(SubExpr);
3195       break;
3196 
3197     case OBC_BridgeRetained:
3198       // Produce the object before casting it.
3199       SubExpr = ImplicitCastExpr::Create(Context, FromType,
3200                                          CK_ARCProduceObject,
3201                                          SubExpr, 0, VK_RValue);
3202       break;
3203 
3204     case OBC_BridgeTransfer: {
3205       bool br = isKnownName("CFBridgingRetain");
3206       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3207         << (FromType->isBlockPointerType()? 1 : 0)
3208         << FromType
3209         << 2
3210         << T
3211         << SubExpr->getSourceRange()
3212         << Kind;
3213 
3214       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3215         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
3216       Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
3217         << T << br
3218         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3219                           br ? "CFBridgingRetain " : "__bridge_retained");
3220 
3221       Kind = OBC_Bridge;
3222       break;
3223     }
3224     }
3225   } else {
3226     Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
3227       << FromType << T << Kind
3228       << SubExpr->getSourceRange()
3229       << TSInfo->getTypeLoc().getSourceRange();
3230     return ExprError();
3231   }
3232 
3233   Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
3234                                                    BridgeKeywordLoc,
3235                                                    TSInfo, SubExpr);
3236 
3237   if (MustConsume) {
3238     ExprNeedsCleanups = true;
3239     Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
3240                                       0, VK_RValue);
3241   }
3242 
3243   return Result;
3244 }
3245 
ActOnObjCBridgedCast(Scope * S,SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,ParsedType Type,SourceLocation RParenLoc,Expr * SubExpr)3246 ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
3247                                       SourceLocation LParenLoc,
3248                                       ObjCBridgeCastKind Kind,
3249                                       SourceLocation BridgeKeywordLoc,
3250                                       ParsedType Type,
3251                                       SourceLocation RParenLoc,
3252                                       Expr *SubExpr) {
3253   TypeSourceInfo *TSInfo = 0;
3254   QualType T = GetTypeFromParser(Type, &TSInfo);
3255   if (!TSInfo)
3256     TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
3257   return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
3258                               SubExpr);
3259 }
3260