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1 //===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements semantic analysis for Objective-C expressions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Sema/SemaInternal.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/ExprObjC.h"
18 #include "clang/AST/StmtVisitor.h"
19 #include "clang/AST/TypeLoc.h"
20 #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
21 #include "clang/Edit/Commit.h"
22 #include "clang/Edit/Rewriters.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Sema/Initialization.h"
25 #include "clang/Sema/Lookup.h"
26 #include "clang/Sema/Scope.h"
27 #include "clang/Sema/ScopeInfo.h"
28 #include "llvm/ADT/SmallString.h"
29 
30 using namespace clang;
31 using namespace sema;
32 using llvm::makeArrayRef;
33 
ParseObjCStringLiteral(SourceLocation * AtLocs,Expr ** strings,unsigned NumStrings)34 ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
35                                         Expr **strings,
36                                         unsigned NumStrings) {
37   StringLiteral **Strings = reinterpret_cast<StringLiteral**>(strings);
38 
39   // Most ObjC strings are formed out of a single piece.  However, we *can*
40   // have strings formed out of multiple @ strings with multiple pptokens in
41   // each one, e.g. @"foo" "bar" @"baz" "qux"   which need to be turned into one
42   // StringLiteral for ObjCStringLiteral to hold onto.
43   StringLiteral *S = Strings[0];
44 
45   // If we have a multi-part string, merge it all together.
46   if (NumStrings != 1) {
47     // Concatenate objc strings.
48     SmallString<128> StrBuf;
49     SmallVector<SourceLocation, 8> StrLocs;
50 
51     for (unsigned i = 0; i != NumStrings; ++i) {
52       S = Strings[i];
53 
54       // ObjC strings can't be wide or UTF.
55       if (!S->isAscii()) {
56         Diag(S->getLocStart(), diag::err_cfstring_literal_not_string_constant)
57           << S->getSourceRange();
58         return true;
59       }
60 
61       // Append the string.
62       StrBuf += S->getString();
63 
64       // Get the locations of the string tokens.
65       StrLocs.append(S->tokloc_begin(), S->tokloc_end());
66     }
67 
68     // Create the aggregate string with the appropriate content and location
69     // information.
70     S = StringLiteral::Create(Context, StrBuf,
71                               StringLiteral::Ascii, /*Pascal=*/false,
72                               Context.getPointerType(Context.CharTy),
73                               &StrLocs[0], StrLocs.size());
74   }
75 
76   return BuildObjCStringLiteral(AtLocs[0], S);
77 }
78 
BuildObjCStringLiteral(SourceLocation AtLoc,StringLiteral * S)79 ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
80   // Verify that this composite string is acceptable for ObjC strings.
81   if (CheckObjCString(S))
82     return true;
83 
84   // Initialize the constant string interface lazily. This assumes
85   // the NSString interface is seen in this translation unit. Note: We
86   // don't use NSConstantString, since the runtime team considers this
87   // interface private (even though it appears in the header files).
88   QualType Ty = Context.getObjCConstantStringInterface();
89   if (!Ty.isNull()) {
90     Ty = Context.getObjCObjectPointerType(Ty);
91   } else if (getLangOpts().NoConstantCFStrings) {
92     IdentifierInfo *NSIdent=0;
93     std::string StringClass(getLangOpts().ObjCConstantStringClass);
94 
95     if (StringClass.empty())
96       NSIdent = &Context.Idents.get("NSConstantString");
97     else
98       NSIdent = &Context.Idents.get(StringClass);
99 
100     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
101                                      LookupOrdinaryName);
102     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
103       Context.setObjCConstantStringInterface(StrIF);
104       Ty = Context.getObjCConstantStringInterface();
105       Ty = Context.getObjCObjectPointerType(Ty);
106     } else {
107       // If there is no NSConstantString interface defined then treat this
108       // as error and recover from it.
109       Diag(S->getLocStart(), diag::err_no_nsconstant_string_class) << NSIdent
110         << S->getSourceRange();
111       Ty = Context.getObjCIdType();
112     }
113   } else {
114     IdentifierInfo *NSIdent = NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
115     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
116                                      LookupOrdinaryName);
117     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
118       Context.setObjCConstantStringInterface(StrIF);
119       Ty = Context.getObjCConstantStringInterface();
120       Ty = Context.getObjCObjectPointerType(Ty);
121     } else {
122       // If there is no NSString interface defined, implicitly declare
123       // a @class NSString; and use that instead. This is to make sure
124       // type of an NSString literal is represented correctly, instead of
125       // being an 'id' type.
126       Ty = Context.getObjCNSStringType();
127       if (Ty.isNull()) {
128         ObjCInterfaceDecl *NSStringIDecl =
129           ObjCInterfaceDecl::Create (Context,
130                                      Context.getTranslationUnitDecl(),
131                                      SourceLocation(), NSIdent,
132                                      0, SourceLocation());
133         Ty = Context.getObjCInterfaceType(NSStringIDecl);
134         Context.setObjCNSStringType(Ty);
135       }
136       Ty = Context.getObjCObjectPointerType(Ty);
137     }
138   }
139 
140   return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
141 }
142 
143 /// \brief Emits an error if the given method does not exist, or if the return
144 /// type is not an Objective-C object.
validateBoxingMethod(Sema & S,SourceLocation Loc,const ObjCInterfaceDecl * Class,Selector Sel,const ObjCMethodDecl * Method)145 static bool validateBoxingMethod(Sema &S, SourceLocation Loc,
146                                  const ObjCInterfaceDecl *Class,
147                                  Selector Sel, const ObjCMethodDecl *Method) {
148   if (!Method) {
149     // FIXME: Is there a better way to avoid quotes than using getName()?
150     S.Diag(Loc, diag::err_undeclared_boxing_method) << Sel << Class->getName();
151     return false;
152   }
153 
154   // Make sure the return type is reasonable.
155   QualType ReturnType = Method->getResultType();
156   if (!ReturnType->isObjCObjectPointerType()) {
157     S.Diag(Loc, diag::err_objc_literal_method_sig)
158       << Sel;
159     S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
160       << ReturnType;
161     return false;
162   }
163 
164   return true;
165 }
166 
167 /// \brief Retrieve the NSNumber factory method that should be used to create
168 /// an Objective-C literal for the given type.
getNSNumberFactoryMethod(Sema & S,SourceLocation Loc,QualType NumberType,bool isLiteral=false,SourceRange R=SourceRange ())169 static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
170                                                 QualType NumberType,
171                                                 bool isLiteral = false,
172                                                 SourceRange R = SourceRange()) {
173   Optional<NSAPI::NSNumberLiteralMethodKind> Kind =
174       S.NSAPIObj->getNSNumberFactoryMethodKind(NumberType);
175 
176   if (!Kind) {
177     if (isLiteral) {
178       S.Diag(Loc, diag::err_invalid_nsnumber_type)
179         << NumberType << R;
180     }
181     return 0;
182   }
183 
184   // If we already looked up this method, we're done.
185   if (S.NSNumberLiteralMethods[*Kind])
186     return S.NSNumberLiteralMethods[*Kind];
187 
188   Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
189                                                         /*Instance=*/false);
190 
191   ASTContext &CX = S.Context;
192 
193   // Look up the NSNumber class, if we haven't done so already. It's cached
194   // in the Sema instance.
195   if (!S.NSNumberDecl) {
196     IdentifierInfo *NSNumberId =
197       S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSNumber);
198     NamedDecl *IF = S.LookupSingleName(S.TUScope, NSNumberId,
199                                        Loc, Sema::LookupOrdinaryName);
200     S.NSNumberDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
201     if (!S.NSNumberDecl) {
202       if (S.getLangOpts().DebuggerObjCLiteral) {
203         // Create a stub definition of NSNumber.
204         S.NSNumberDecl = ObjCInterfaceDecl::Create(CX,
205                                                    CX.getTranslationUnitDecl(),
206                                                    SourceLocation(), NSNumberId,
207                                                    0, SourceLocation());
208       } else {
209         // Otherwise, require a declaration of NSNumber.
210         S.Diag(Loc, diag::err_undeclared_nsnumber);
211         return 0;
212       }
213     } else if (!S.NSNumberDecl->hasDefinition()) {
214       S.Diag(Loc, diag::err_undeclared_nsnumber);
215       return 0;
216     }
217 
218     // generate the pointer to NSNumber type.
219     QualType NSNumberObject = CX.getObjCInterfaceType(S.NSNumberDecl);
220     S.NSNumberPointer = CX.getObjCObjectPointerType(NSNumberObject);
221   }
222 
223   // Look for the appropriate method within NSNumber.
224   ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);
225   if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
226     // create a stub definition this NSNumber factory method.
227     TypeSourceInfo *ResultTInfo = 0;
228     Method = ObjCMethodDecl::Create(CX, SourceLocation(), SourceLocation(), Sel,
229                                     S.NSNumberPointer, ResultTInfo,
230                                     S.NSNumberDecl,
231                                     /*isInstance=*/false, /*isVariadic=*/false,
232                                     /*isPropertyAccessor=*/false,
233                                     /*isImplicitlyDeclared=*/true,
234                                     /*isDefined=*/false,
235                                     ObjCMethodDecl::Required,
236                                     /*HasRelatedResultType=*/false);
237     ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
238                                              SourceLocation(), SourceLocation(),
239                                              &CX.Idents.get("value"),
240                                              NumberType, /*TInfo=*/0, SC_None,
241                                              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                                    /*isPropertyAccessor=*/false,
481                                    /*isImplicitlyDeclared=*/true,
482                                    /*isDefined=*/false,
483                                    ObjCMethodDecl::Required,
484                                    /*HasRelatedResultType=*/false);
485           QualType ConstCharType = Context.CharTy.withConst();
486           ParmVarDecl *value =
487             ParmVarDecl::Create(Context, M,
488                                 SourceLocation(), SourceLocation(),
489                                 &Context.Idents.get("value"),
490                                 Context.getPointerType(ConstCharType),
491                                 /*TInfo=*/0,
492                                 SC_None, 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                            /*isPropertyAccessor=*/false,
650                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
651                            ObjCMethodDecl::Required,
652                            false);
653       SmallVector<ParmVarDecl *, 2> Params;
654       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
655                                                  SourceLocation(),
656                                                  SourceLocation(),
657                                                  &Context.Idents.get("objects"),
658                                                  Context.getPointerType(IdT),
659                                                  /*TInfo=*/0, SC_None, 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                            /*isPropertyAccessor=*/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, AtLoc));
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;
1139       if (getLangOpts().DebuggerSupport) {
1140         QualType paramTy; // ignored
1141         result = checkUnknownAnyArg(lbrac, Args[i], paramTy);
1142       } else {
1143         result = DefaultArgumentPromotion(Args[i]);
1144       }
1145       if (result.isInvalid())
1146         return true;
1147       Args[i] = result.take();
1148     }
1149 
1150     unsigned DiagID;
1151     if (getLangOpts().ObjCAutoRefCount)
1152       DiagID = diag::err_arc_method_not_found;
1153     else
1154       DiagID = isClassMessage ? diag::warn_class_method_not_found
1155                               : diag::warn_inst_method_not_found;
1156     if (!getLangOpts().DebuggerSupport)
1157       Diag(lbrac, DiagID)
1158         << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
1159                                                 SelectorLocs.back());
1160 
1161     // In debuggers, we want to use __unknown_anytype for these
1162     // results so that clients can cast them.
1163     if (getLangOpts().DebuggerSupport) {
1164       ReturnType = Context.UnknownAnyTy;
1165     } else {
1166       ReturnType = Context.getObjCIdType();
1167     }
1168     VK = VK_RValue;
1169     return false;
1170   }
1171 
1172   ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage,
1173                                         isSuperMessage);
1174   VK = Expr::getValueKindForType(Method->getResultType());
1175 
1176   unsigned NumNamedArgs = Sel.getNumArgs();
1177   // Method might have more arguments than selector indicates. This is due
1178   // to addition of c-style arguments in method.
1179   if (Method->param_size() > Sel.getNumArgs())
1180     NumNamedArgs = Method->param_size();
1181   // FIXME. This need be cleaned up.
1182   if (NumArgs < NumNamedArgs) {
1183     Diag(lbrac, diag::err_typecheck_call_too_few_args)
1184       << 2 << NumNamedArgs << NumArgs;
1185     return false;
1186   }
1187 
1188   bool IsError = false;
1189   for (unsigned i = 0; i < NumNamedArgs; i++) {
1190     // We can't do any type-checking on a type-dependent argument.
1191     if (Args[i]->isTypeDependent())
1192       continue;
1193 
1194     Expr *argExpr = Args[i];
1195 
1196     ParmVarDecl *param = Method->param_begin()[i];
1197     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
1198 
1199     // Strip the unbridged-cast placeholder expression off unless it's
1200     // a consumed argument.
1201     if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
1202         !param->hasAttr<CFConsumedAttr>())
1203       argExpr = stripARCUnbridgedCast(argExpr);
1204 
1205     // If the parameter is __unknown_anytype, infer its type
1206     // from the argument.
1207     if (param->getType() == Context.UnknownAnyTy) {
1208       QualType paramType;
1209       ExprResult argE = checkUnknownAnyArg(lbrac, argExpr, paramType);
1210       if (argE.isInvalid()) {
1211         IsError = true;
1212       } else {
1213         Args[i] = argE.take();
1214 
1215         // Update the parameter type in-place.
1216         param->setType(paramType);
1217       }
1218       continue;
1219     }
1220 
1221     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
1222                             param->getType(),
1223                             diag::err_call_incomplete_argument, argExpr))
1224       return true;
1225 
1226     InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1227                                                                       param);
1228     ExprResult ArgE = PerformCopyInitialization(Entity, lbrac, Owned(argExpr));
1229     if (ArgE.isInvalid())
1230       IsError = true;
1231     else
1232       Args[i] = ArgE.takeAs<Expr>();
1233   }
1234 
1235   // Promote additional arguments to variadic methods.
1236   if (Method->isVariadic()) {
1237     for (unsigned i = NumNamedArgs; i < NumArgs; ++i) {
1238       if (Args[i]->isTypeDependent())
1239         continue;
1240 
1241       ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
1242                                                         0);
1243       IsError |= Arg.isInvalid();
1244       Args[i] = Arg.take();
1245     }
1246   } else {
1247     // Check for extra arguments to non-variadic methods.
1248     if (NumArgs != NumNamedArgs) {
1249       Diag(Args[NumNamedArgs]->getLocStart(),
1250            diag::err_typecheck_call_too_many_args)
1251         << 2 /*method*/ << NumNamedArgs << NumArgs
1252         << Method->getSourceRange()
1253         << SourceRange(Args[NumNamedArgs]->getLocStart(),
1254                        Args[NumArgs-1]->getLocEnd());
1255     }
1256   }
1257 
1258   DiagnoseSentinelCalls(Method, lbrac, Args, NumArgs);
1259 
1260   // Do additional checkings on method.
1261   IsError |= CheckObjCMethodCall(Method, lbrac, Args, NumArgs);
1262 
1263   return IsError;
1264 }
1265 
isSelfExpr(Expr * receiver)1266 bool Sema::isSelfExpr(Expr *receiver) {
1267   // 'self' is objc 'self' in an objc method only.
1268   ObjCMethodDecl *method =
1269     dyn_cast<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
1270   if (!method) return false;
1271 
1272   receiver = receiver->IgnoreParenLValueCasts();
1273   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
1274     if (DRE->getDecl() == method->getSelfDecl())
1275       return true;
1276   return false;
1277 }
1278 
1279 /// LookupMethodInType - Look up a method in an ObjCObjectType.
LookupMethodInObjectType(Selector sel,QualType type,bool isInstance)1280 ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
1281                                                bool isInstance) {
1282   const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
1283   if (ObjCInterfaceDecl *iface = objType->getInterface()) {
1284     // Look it up in the main interface (and categories, etc.)
1285     if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
1286       return method;
1287 
1288     // Okay, look for "private" methods declared in any
1289     // @implementations we've seen.
1290     if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
1291       return method;
1292   }
1293 
1294   // Check qualifiers.
1295   for (ObjCObjectType::qual_iterator
1296          i = objType->qual_begin(), e = objType->qual_end(); i != e; ++i)
1297     if (ObjCMethodDecl *method = (*i)->lookupMethod(sel, isInstance))
1298       return method;
1299 
1300   return 0;
1301 }
1302 
1303 /// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1304 /// list of a qualified objective pointer type.
LookupMethodInQualifiedType(Selector Sel,const ObjCObjectPointerType * OPT,bool Instance)1305 ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
1306                                               const ObjCObjectPointerType *OPT,
1307                                               bool Instance)
1308 {
1309   ObjCMethodDecl *MD = 0;
1310   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1311        E = OPT->qual_end(); I != E; ++I) {
1312     ObjCProtocolDecl *PROTO = (*I);
1313     if ((MD = PROTO->lookupMethod(Sel, Instance))) {
1314       return MD;
1315     }
1316   }
1317   return 0;
1318 }
1319 
DiagnoseARCUseOfWeakReceiver(Sema & S,Expr * Receiver)1320 static void DiagnoseARCUseOfWeakReceiver(Sema &S, Expr *Receiver) {
1321   if (!Receiver)
1322     return;
1323 
1324   if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Receiver))
1325     Receiver = OVE->getSourceExpr();
1326 
1327   Expr *RExpr = Receiver->IgnoreParenImpCasts();
1328   SourceLocation Loc = RExpr->getLocStart();
1329   QualType T = RExpr->getType();
1330   const ObjCPropertyDecl *PDecl = 0;
1331   const ObjCMethodDecl *GDecl = 0;
1332   if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(RExpr)) {
1333     RExpr = POE->getSyntacticForm();
1334     if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(RExpr)) {
1335       if (PRE->isImplicitProperty()) {
1336         GDecl = PRE->getImplicitPropertyGetter();
1337         if (GDecl) {
1338           T = GDecl->getResultType();
1339         }
1340       }
1341       else {
1342         PDecl = PRE->getExplicitProperty();
1343         if (PDecl) {
1344           T = PDecl->getType();
1345         }
1346       }
1347     }
1348   }
1349   else if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RExpr)) {
1350     // See if receiver is a method which envokes a synthesized getter
1351     // backing a 'weak' property.
1352     ObjCMethodDecl *Method = ME->getMethodDecl();
1353     if (Method && Method->getSelector().getNumArgs() == 0) {
1354       PDecl = Method->findPropertyDecl();
1355       if (PDecl)
1356         T = PDecl->getType();
1357     }
1358   }
1359 
1360   if (T.getObjCLifetime() != Qualifiers::OCL_Weak) {
1361     if (!PDecl)
1362       return;
1363     if (!(PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak))
1364       return;
1365   }
1366 
1367   S.Diag(Loc, diag::warn_receiver_is_weak)
1368     << ((!PDecl && !GDecl) ? 0 : (PDecl ? 1 : 2));
1369 
1370   if (PDecl)
1371     S.Diag(PDecl->getLocation(), diag::note_property_declare);
1372   else if (GDecl)
1373     S.Diag(GDecl->getLocation(), diag::note_method_declared_at) << GDecl;
1374 
1375   S.Diag(Loc, diag::note_arc_assign_to_strong);
1376 }
1377 
1378 /// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1379 /// objective C interface.  This is a property reference expression.
1380 ExprResult Sema::
HandleExprPropertyRefExpr(const ObjCObjectPointerType * OPT,Expr * BaseExpr,SourceLocation OpLoc,DeclarationName MemberName,SourceLocation MemberLoc,SourceLocation SuperLoc,QualType SuperType,bool Super)1381 HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
1382                           Expr *BaseExpr, SourceLocation OpLoc,
1383                           DeclarationName MemberName,
1384                           SourceLocation MemberLoc,
1385                           SourceLocation SuperLoc, QualType SuperType,
1386                           bool Super) {
1387   const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
1388   ObjCInterfaceDecl *IFace = IFaceT->getDecl();
1389 
1390   if (!MemberName.isIdentifier()) {
1391     Diag(MemberLoc, diag::err_invalid_property_name)
1392       << MemberName << QualType(OPT, 0);
1393     return ExprError();
1394   }
1395 
1396   IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1397 
1398   SourceRange BaseRange = Super? SourceRange(SuperLoc)
1399                                : BaseExpr->getSourceRange();
1400   if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
1401                           diag::err_property_not_found_forward_class,
1402                           MemberName, BaseRange))
1403     return ExprError();
1404 
1405   // Search for a declared property first.
1406   if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
1407     // Check whether we can reference this property.
1408     if (DiagnoseUseOfDecl(PD, MemberLoc))
1409       return ExprError();
1410     if (Super)
1411       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1412                                                      VK_LValue, OK_ObjCProperty,
1413                                                      MemberLoc,
1414                                                      SuperLoc, SuperType));
1415     else
1416       return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
1417                                                      VK_LValue, OK_ObjCProperty,
1418                                                      MemberLoc, BaseExpr));
1419   }
1420   // Check protocols on qualified interfaces.
1421   for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
1422        E = OPT->qual_end(); I != E; ++I)
1423     if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) {
1424       // Check whether we can reference this property.
1425       if (DiagnoseUseOfDecl(PD, MemberLoc))
1426         return ExprError();
1427 
1428       if (Super)
1429         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1430                                                        Context.PseudoObjectTy,
1431                                                        VK_LValue,
1432                                                        OK_ObjCProperty,
1433                                                        MemberLoc,
1434                                                        SuperLoc, SuperType));
1435       else
1436         return Owned(new (Context) ObjCPropertyRefExpr(PD,
1437                                                        Context.PseudoObjectTy,
1438                                                        VK_LValue,
1439                                                        OK_ObjCProperty,
1440                                                        MemberLoc,
1441                                                        BaseExpr));
1442     }
1443   // If that failed, look for an "implicit" property by seeing if the nullary
1444   // selector is implemented.
1445 
1446   // FIXME: The logic for looking up nullary and unary selectors should be
1447   // shared with the code in ActOnInstanceMessage.
1448 
1449   Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
1450   ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
1451 
1452   // May be founf in property's qualified list.
1453   if (!Getter)
1454     Getter = LookupMethodInQualifiedType(Sel, OPT, true);
1455 
1456   // If this reference is in an @implementation, check for 'private' methods.
1457   if (!Getter)
1458     Getter = IFace->lookupPrivateMethod(Sel);
1459 
1460   if (Getter) {
1461     // Check if we can reference this property.
1462     if (DiagnoseUseOfDecl(Getter, MemberLoc))
1463       return ExprError();
1464   }
1465   // If we found a getter then this may be a valid dot-reference, we
1466   // will look for the matching setter, in case it is needed.
1467   Selector SetterSel =
1468     SelectorTable::constructSetterName(PP.getIdentifierTable(),
1469                                        PP.getSelectorTable(), Member);
1470   ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
1471 
1472   // May be founf in property's qualified list.
1473   if (!Setter)
1474     Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
1475 
1476   if (!Setter) {
1477     // If this reference is in an @implementation, also check for 'private'
1478     // methods.
1479     Setter = IFace->lookupPrivateMethod(SetterSel);
1480   }
1481 
1482   if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
1483     return ExprError();
1484 
1485   if (Getter || Setter) {
1486     if (Super)
1487       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1488                                                      Context.PseudoObjectTy,
1489                                                      VK_LValue, OK_ObjCProperty,
1490                                                      MemberLoc,
1491                                                      SuperLoc, SuperType));
1492     else
1493       return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1494                                                      Context.PseudoObjectTy,
1495                                                      VK_LValue, OK_ObjCProperty,
1496                                                      MemberLoc, BaseExpr));
1497 
1498   }
1499 
1500   // Attempt to correct for typos in property names.
1501   DeclFilterCCC<ObjCPropertyDecl> Validator;
1502   if (TypoCorrection Corrected = CorrectTypo(
1503       DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName, NULL,
1504       NULL, Validator, IFace, false, OPT)) {
1505     ObjCPropertyDecl *Property =
1506         Corrected.getCorrectionDeclAs<ObjCPropertyDecl>();
1507     DeclarationName TypoResult = Corrected.getCorrection();
1508     Diag(MemberLoc, diag::err_property_not_found_suggest)
1509       << MemberName << QualType(OPT, 0) << TypoResult
1510       << FixItHint::CreateReplacement(MemberLoc, TypoResult.getAsString());
1511     Diag(Property->getLocation(), diag::note_previous_decl)
1512       << Property->getDeclName();
1513     return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
1514                                      TypoResult, MemberLoc,
1515                                      SuperLoc, SuperType, Super);
1516   }
1517   ObjCInterfaceDecl *ClassDeclared;
1518   if (ObjCIvarDecl *Ivar =
1519       IFace->lookupInstanceVariable(Member, ClassDeclared)) {
1520     QualType T = Ivar->getType();
1521     if (const ObjCObjectPointerType * OBJPT =
1522         T->getAsObjCInterfacePointerType()) {
1523       if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
1524                               diag::err_property_not_as_forward_class,
1525                               MemberName, BaseExpr))
1526         return ExprError();
1527     }
1528     Diag(MemberLoc,
1529          diag::err_ivar_access_using_property_syntax_suggest)
1530     << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
1531     << FixItHint::CreateReplacement(OpLoc, "->");
1532     return ExprError();
1533   }
1534 
1535   Diag(MemberLoc, diag::err_property_not_found)
1536     << MemberName << QualType(OPT, 0);
1537   if (Setter)
1538     Diag(Setter->getLocation(), diag::note_getter_unavailable)
1539           << MemberName << BaseExpr->getSourceRange();
1540   return ExprError();
1541 }
1542 
1543 
1544 
1545 ExprResult Sema::
ActOnClassPropertyRefExpr(IdentifierInfo & receiverName,IdentifierInfo & propertyName,SourceLocation receiverNameLoc,SourceLocation propertyNameLoc)1546 ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
1547                           IdentifierInfo &propertyName,
1548                           SourceLocation receiverNameLoc,
1549                           SourceLocation propertyNameLoc) {
1550 
1551   IdentifierInfo *receiverNamePtr = &receiverName;
1552   ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
1553                                                   receiverNameLoc);
1554 
1555   bool IsSuper = false;
1556   if (IFace == 0) {
1557     // If the "receiver" is 'super' in a method, handle it as an expression-like
1558     // property reference.
1559     if (receiverNamePtr->isStr("super")) {
1560       IsSuper = true;
1561 
1562       if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
1563         if (CurMethod->isInstanceMethod()) {
1564           ObjCInterfaceDecl *Super =
1565             CurMethod->getClassInterface()->getSuperClass();
1566           if (!Super) {
1567             // The current class does not have a superclass.
1568             Diag(receiverNameLoc, diag::error_root_class_cannot_use_super)
1569             << CurMethod->getClassInterface()->getIdentifier();
1570             return ExprError();
1571           }
1572           QualType T = Context.getObjCInterfaceType(Super);
1573           T = Context.getObjCObjectPointerType(T);
1574 
1575           return HandleExprPropertyRefExpr(T->getAsObjCInterfacePointerType(),
1576                                            /*BaseExpr*/0,
1577                                            SourceLocation()/*OpLoc*/,
1578                                            &propertyName,
1579                                            propertyNameLoc,
1580                                            receiverNameLoc, T, true);
1581         }
1582 
1583         // Otherwise, if this is a class method, try dispatching to our
1584         // superclass.
1585         IFace = CurMethod->getClassInterface()->getSuperClass();
1586       }
1587     }
1588 
1589     if (IFace == 0) {
1590       Diag(receiverNameLoc, diag::err_expected_ident_or_lparen);
1591       return ExprError();
1592     }
1593   }
1594 
1595   // Search for a declared property first.
1596   Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
1597   ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
1598 
1599   // If this reference is in an @implementation, check for 'private' methods.
1600   if (!Getter)
1601     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1602       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1603         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1604           Getter = ImpDecl->getClassMethod(Sel);
1605 
1606   if (Getter) {
1607     // FIXME: refactor/share with ActOnMemberReference().
1608     // Check if we can reference this property.
1609     if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
1610       return ExprError();
1611   }
1612 
1613   // Look for the matching setter, in case it is needed.
1614   Selector SetterSel =
1615     SelectorTable::constructSetterName(PP.getIdentifierTable(),
1616                                        PP.getSelectorTable(), &propertyName);
1617 
1618   ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1619   if (!Setter) {
1620     // If this reference is in an @implementation, also check for 'private'
1621     // methods.
1622     if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
1623       if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
1624         if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
1625           Setter = ImpDecl->getClassMethod(SetterSel);
1626   }
1627   // Look through local category implementations associated with the class.
1628   if (!Setter)
1629     Setter = IFace->getCategoryClassMethod(SetterSel);
1630 
1631   if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
1632     return ExprError();
1633 
1634   if (Getter || Setter) {
1635     if (IsSuper)
1636     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1637                                                    Context.PseudoObjectTy,
1638                                                    VK_LValue, OK_ObjCProperty,
1639                                                    propertyNameLoc,
1640                                                    receiverNameLoc,
1641                                           Context.getObjCInterfaceType(IFace)));
1642 
1643     return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
1644                                                    Context.PseudoObjectTy,
1645                                                    VK_LValue, OK_ObjCProperty,
1646                                                    propertyNameLoc,
1647                                                    receiverNameLoc, IFace));
1648   }
1649   return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
1650                      << &propertyName << Context.getObjCInterfaceType(IFace));
1651 }
1652 
1653 namespace {
1654 
1655 class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
1656  public:
ObjCInterfaceOrSuperCCC(ObjCMethodDecl * Method)1657   ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
1658     // Determine whether "super" is acceptable in the current context.
1659     if (Method && Method->getClassInterface())
1660       WantObjCSuper = Method->getClassInterface()->getSuperClass();
1661   }
1662 
ValidateCandidate(const TypoCorrection & candidate)1663   virtual bool ValidateCandidate(const TypoCorrection &candidate) {
1664     return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
1665         candidate.isKeyword("super");
1666   }
1667 };
1668 
1669 }
1670 
getObjCMessageKind(Scope * S,IdentifierInfo * Name,SourceLocation NameLoc,bool IsSuper,bool HasTrailingDot,ParsedType & ReceiverType)1671 Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
1672                                                IdentifierInfo *Name,
1673                                                SourceLocation NameLoc,
1674                                                bool IsSuper,
1675                                                bool HasTrailingDot,
1676                                                ParsedType &ReceiverType) {
1677   ReceiverType = ParsedType();
1678 
1679   // If the identifier is "super" and there is no trailing dot, we're
1680   // messaging super. If the identifier is "super" and there is a
1681   // trailing dot, it's an instance message.
1682   if (IsSuper && S->isInObjcMethodScope())
1683     return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
1684 
1685   LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1686   LookupName(Result, S);
1687 
1688   switch (Result.getResultKind()) {
1689   case LookupResult::NotFound:
1690     // Normal name lookup didn't find anything. If we're in an
1691     // Objective-C method, look for ivars. If we find one, we're done!
1692     // FIXME: This is a hack. Ivar lookup should be part of normal
1693     // lookup.
1694     if (ObjCMethodDecl *Method = getCurMethodDecl()) {
1695       if (!Method->getClassInterface()) {
1696         // Fall back: let the parser try to parse it as an instance message.
1697         return ObjCInstanceMessage;
1698       }
1699 
1700       ObjCInterfaceDecl *ClassDeclared;
1701       if (Method->getClassInterface()->lookupInstanceVariable(Name,
1702                                                               ClassDeclared))
1703         return ObjCInstanceMessage;
1704     }
1705 
1706     // Break out; we'll perform typo correction below.
1707     break;
1708 
1709   case LookupResult::NotFoundInCurrentInstantiation:
1710   case LookupResult::FoundOverloaded:
1711   case LookupResult::FoundUnresolvedValue:
1712   case LookupResult::Ambiguous:
1713     Result.suppressDiagnostics();
1714     return ObjCInstanceMessage;
1715 
1716   case LookupResult::Found: {
1717     // If the identifier is a class or not, and there is a trailing dot,
1718     // it's an instance message.
1719     if (HasTrailingDot)
1720       return ObjCInstanceMessage;
1721     // We found something. If it's a type, then we have a class
1722     // message. Otherwise, it's an instance message.
1723     NamedDecl *ND = Result.getFoundDecl();
1724     QualType T;
1725     if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
1726       T = Context.getObjCInterfaceType(Class);
1727     else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND))
1728       T = Context.getTypeDeclType(Type);
1729     else
1730       return ObjCInstanceMessage;
1731 
1732     //  We have a class message, and T is the type we're
1733     //  messaging. Build source-location information for it.
1734     TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1735     ReceiverType = CreateParsedType(T, TSInfo);
1736     return ObjCClassMessage;
1737   }
1738   }
1739 
1740   ObjCInterfaceOrSuperCCC Validator(getCurMethodDecl());
1741   if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(),
1742                                              Result.getLookupKind(), S, NULL,
1743                                              Validator)) {
1744     if (Corrected.isKeyword()) {
1745       // If we've found the keyword "super" (the only keyword that would be
1746       // returned by CorrectTypo), this is a send to super.
1747       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1748         << Name << Corrected.getCorrection()
1749         << FixItHint::CreateReplacement(SourceRange(NameLoc), "super");
1750       return ObjCSuperMessage;
1751     } else if (ObjCInterfaceDecl *Class =
1752                Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1753       // If we found a declaration, correct when it refers to an Objective-C
1754       // class.
1755       Diag(NameLoc, diag::err_unknown_receiver_suggest)
1756         << Name << Corrected.getCorrection()
1757         << FixItHint::CreateReplacement(SourceRange(NameLoc),
1758                                         Class->getNameAsString());
1759       Diag(Class->getLocation(), diag::note_previous_decl)
1760         << Corrected.getCorrection();
1761 
1762       QualType T = Context.getObjCInterfaceType(Class);
1763       TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1764       ReceiverType = CreateParsedType(T, TSInfo);
1765       return ObjCClassMessage;
1766     }
1767   }
1768 
1769   // Fall back: let the parser try to parse it as an instance message.
1770   return ObjCInstanceMessage;
1771 }
1772 
ActOnSuperMessage(Scope * S,SourceLocation SuperLoc,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)1773 ExprResult Sema::ActOnSuperMessage(Scope *S,
1774                                    SourceLocation SuperLoc,
1775                                    Selector Sel,
1776                                    SourceLocation LBracLoc,
1777                                    ArrayRef<SourceLocation> SelectorLocs,
1778                                    SourceLocation RBracLoc,
1779                                    MultiExprArg Args) {
1780   // Determine whether we are inside a method or not.
1781   ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
1782   if (!Method) {
1783     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
1784     return ExprError();
1785   }
1786 
1787   ObjCInterfaceDecl *Class = Method->getClassInterface();
1788   if (!Class) {
1789     Diag(SuperLoc, diag::error_no_super_class_message)
1790       << Method->getDeclName();
1791     return ExprError();
1792   }
1793 
1794   ObjCInterfaceDecl *Super = Class->getSuperClass();
1795   if (!Super) {
1796     // The current class does not have a superclass.
1797     Diag(SuperLoc, diag::error_root_class_cannot_use_super)
1798       << Class->getIdentifier();
1799     return ExprError();
1800   }
1801 
1802   // We are in a method whose class has a superclass, so 'super'
1803   // is acting as a keyword.
1804   if (Method->getSelector() == Sel)
1805     getCurFunction()->ObjCShouldCallSuper = false;
1806 
1807   if (Method->isInstanceMethod()) {
1808     // Since we are in an instance method, this is an instance
1809     // message to the superclass instance.
1810     QualType SuperTy = Context.getObjCInterfaceType(Super);
1811     SuperTy = Context.getObjCObjectPointerType(SuperTy);
1812     return BuildInstanceMessage(0, SuperTy, SuperLoc,
1813                                 Sel, /*Method=*/0,
1814                                 LBracLoc, SelectorLocs, RBracLoc, Args);
1815   }
1816 
1817   // Since we are in a class method, this is a class message to
1818   // the superclass.
1819   return BuildClassMessage(/*ReceiverTypeInfo=*/0,
1820                            Context.getObjCInterfaceType(Super),
1821                            SuperLoc, Sel, /*Method=*/0,
1822                            LBracLoc, SelectorLocs, RBracLoc, Args);
1823 }
1824 
1825 
BuildClassMessageImplicit(QualType ReceiverType,bool isSuperReceiver,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)1826 ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
1827                                            bool isSuperReceiver,
1828                                            SourceLocation Loc,
1829                                            Selector Sel,
1830                                            ObjCMethodDecl *Method,
1831                                            MultiExprArg Args) {
1832   TypeSourceInfo *receiverTypeInfo = 0;
1833   if (!ReceiverType.isNull())
1834     receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
1835 
1836   return BuildClassMessage(receiverTypeInfo, ReceiverType,
1837                           /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
1838                            Sel, Method, Loc, Loc, Loc, Args,
1839                            /*isImplicit=*/true);
1840 
1841 }
1842 
applyCocoaAPICheck(Sema & S,const ObjCMessageExpr * Msg,unsigned DiagID,bool (* refactor)(const ObjCMessageExpr *,const NSAPI &,edit::Commit &))1843 static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
1844                                unsigned DiagID,
1845                                bool (*refactor)(const ObjCMessageExpr *,
1846                                               const NSAPI &, edit::Commit &)) {
1847   SourceLocation MsgLoc = Msg->getExprLoc();
1848   if (S.Diags.getDiagnosticLevel(DiagID, MsgLoc) == DiagnosticsEngine::Ignored)
1849     return;
1850 
1851   SourceManager &SM = S.SourceMgr;
1852   edit::Commit ECommit(SM, S.LangOpts);
1853   if (refactor(Msg,*S.NSAPIObj, ECommit)) {
1854     DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
1855                         << Msg->getSelector() << Msg->getSourceRange();
1856     // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
1857     if (!ECommit.isCommitable())
1858       return;
1859     for (edit::Commit::edit_iterator
1860            I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
1861       const edit::Commit::Edit &Edit = *I;
1862       switch (Edit.Kind) {
1863       case edit::Commit::Act_Insert:
1864         Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
1865                                                         Edit.Text,
1866                                                         Edit.BeforePrev));
1867         break;
1868       case edit::Commit::Act_InsertFromRange:
1869         Builder.AddFixItHint(
1870             FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
1871                                                 Edit.getInsertFromRange(SM),
1872                                                 Edit.BeforePrev));
1873         break;
1874       case edit::Commit::Act_Remove:
1875         Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
1876         break;
1877       }
1878     }
1879   }
1880 }
1881 
checkCocoaAPI(Sema & S,const ObjCMessageExpr * Msg)1882 static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
1883   applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
1884                      edit::rewriteObjCRedundantCallWithLiteral);
1885 }
1886 
1887 /// \brief Build an Objective-C class message expression.
1888 ///
1889 /// This routine takes care of both normal class messages and
1890 /// class messages to the superclass.
1891 ///
1892 /// \param ReceiverTypeInfo Type source information that describes the
1893 /// receiver of this message. This may be NULL, in which case we are
1894 /// sending to the superclass and \p SuperLoc must be a valid source
1895 /// location.
1896 
1897 /// \param ReceiverType The type of the object receiving the
1898 /// message. When \p ReceiverTypeInfo is non-NULL, this is the same
1899 /// type as that refers to. For a superclass send, this is the type of
1900 /// the superclass.
1901 ///
1902 /// \param SuperLoc The location of the "super" keyword in a
1903 /// superclass message.
1904 ///
1905 /// \param Sel The selector to which the message is being sent.
1906 ///
1907 /// \param Method The method that this class message is invoking, if
1908 /// already known.
1909 ///
1910 /// \param LBracLoc The location of the opening square bracket ']'.
1911 ///
1912 /// \param RBracLoc The location of the closing square bracket ']'.
1913 ///
1914 /// \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)1915 ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
1916                                    QualType ReceiverType,
1917                                    SourceLocation SuperLoc,
1918                                    Selector Sel,
1919                                    ObjCMethodDecl *Method,
1920                                    SourceLocation LBracLoc,
1921                                    ArrayRef<SourceLocation> SelectorLocs,
1922                                    SourceLocation RBracLoc,
1923                                    MultiExprArg ArgsIn,
1924                                    bool isImplicit) {
1925   SourceLocation Loc = SuperLoc.isValid()? SuperLoc
1926     : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
1927   if (LBracLoc.isInvalid()) {
1928     Diag(Loc, diag::err_missing_open_square_message_send)
1929       << FixItHint::CreateInsertion(Loc, "[");
1930     LBracLoc = Loc;
1931   }
1932 
1933   if (ReceiverType->isDependentType()) {
1934     // If the receiver type is dependent, we can't type-check anything
1935     // at this point. Build a dependent expression.
1936     unsigned NumArgs = ArgsIn.size();
1937     Expr **Args = ArgsIn.data();
1938     assert(SuperLoc.isInvalid() && "Message to super with dependent type");
1939     return Owned(ObjCMessageExpr::Create(Context, ReceiverType,
1940                                          VK_RValue, LBracLoc, ReceiverTypeInfo,
1941                                          Sel, SelectorLocs, /*Method=*/0,
1942                                          makeArrayRef(Args, NumArgs),RBracLoc,
1943                                          isImplicit));
1944   }
1945 
1946   // Find the class to which we are sending this message.
1947   ObjCInterfaceDecl *Class = 0;
1948   const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
1949   if (!ClassType || !(Class = ClassType->getInterface())) {
1950     Diag(Loc, diag::err_invalid_receiver_class_message)
1951       << ReceiverType;
1952     return ExprError();
1953   }
1954   assert(Class && "We don't know which class we're messaging?");
1955   // objc++ diagnoses during typename annotation.
1956   if (!getLangOpts().CPlusPlus)
1957     (void)DiagnoseUseOfDecl(Class, Loc);
1958   // Find the method we are messaging.
1959   if (!Method) {
1960     SourceRange TypeRange
1961       = SuperLoc.isValid()? SourceRange(SuperLoc)
1962                           : ReceiverTypeInfo->getTypeLoc().getSourceRange();
1963     if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
1964                             (getLangOpts().ObjCAutoRefCount
1965                                ? diag::err_arc_receiver_forward_class
1966                                : diag::warn_receiver_forward_class),
1967                             TypeRange)) {
1968       // A forward class used in messaging is treated as a 'Class'
1969       Method = LookupFactoryMethodInGlobalPool(Sel,
1970                                                SourceRange(LBracLoc, RBracLoc));
1971       if (Method && !getLangOpts().ObjCAutoRefCount)
1972         Diag(Method->getLocation(), diag::note_method_sent_forward_class)
1973           << Method->getDeclName();
1974     }
1975     if (!Method)
1976       Method = Class->lookupClassMethod(Sel);
1977 
1978     // If we have an implementation in scope, check "private" methods.
1979     if (!Method)
1980       Method = Class->lookupPrivateClassMethod(Sel);
1981 
1982     if (Method && DiagnoseUseOfDecl(Method, Loc))
1983       return ExprError();
1984   }
1985 
1986   // Check the argument types and determine the result type.
1987   QualType ReturnType;
1988   ExprValueKind VK = VK_RValue;
1989 
1990   unsigned NumArgs = ArgsIn.size();
1991   Expr **Args = ArgsIn.data();
1992   if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel, SelectorLocs,
1993                                 Method, true,
1994                                 SuperLoc.isValid(), LBracLoc, RBracLoc,
1995                                 ReturnType, VK))
1996     return ExprError();
1997 
1998   if (Method && !Method->getResultType()->isVoidType() &&
1999       RequireCompleteType(LBracLoc, Method->getResultType(),
2000                           diag::err_illegal_message_expr_incomplete_type))
2001     return ExprError();
2002 
2003   // Construct the appropriate ObjCMessageExpr.
2004   ObjCMessageExpr *Result;
2005   if (SuperLoc.isValid())
2006     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2007                                      SuperLoc, /*IsInstanceSuper=*/false,
2008                                      ReceiverType, Sel, SelectorLocs,
2009                                      Method, makeArrayRef(Args, NumArgs),
2010                                      RBracLoc, isImplicit);
2011   else {
2012     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2013                                      ReceiverTypeInfo, Sel, SelectorLocs,
2014                                      Method, makeArrayRef(Args, NumArgs),
2015                                      RBracLoc, isImplicit);
2016     if (!isImplicit)
2017       checkCocoaAPI(*this, Result);
2018   }
2019   return MaybeBindToTemporary(Result);
2020 }
2021 
2022 // ActOnClassMessage - used for both unary and keyword messages.
2023 // ArgExprs is optional - if it is present, the number of expressions
2024 // is obtained from Sel.getNumArgs().
ActOnClassMessage(Scope * S,ParsedType Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2025 ExprResult Sema::ActOnClassMessage(Scope *S,
2026                                    ParsedType Receiver,
2027                                    Selector Sel,
2028                                    SourceLocation LBracLoc,
2029                                    ArrayRef<SourceLocation> SelectorLocs,
2030                                    SourceLocation RBracLoc,
2031                                    MultiExprArg Args) {
2032   TypeSourceInfo *ReceiverTypeInfo;
2033   QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
2034   if (ReceiverType.isNull())
2035     return ExprError();
2036 
2037 
2038   if (!ReceiverTypeInfo)
2039     ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
2040 
2041   return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
2042                            /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2043                            LBracLoc, SelectorLocs, RBracLoc, Args);
2044 }
2045 
BuildInstanceMessageImplicit(Expr * Receiver,QualType ReceiverType,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)2046 ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
2047                                               QualType ReceiverType,
2048                                               SourceLocation Loc,
2049                                               Selector Sel,
2050                                               ObjCMethodDecl *Method,
2051                                               MultiExprArg Args) {
2052   return BuildInstanceMessage(Receiver, ReceiverType,
2053                               /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
2054                               Sel, Method, Loc, Loc, Loc, Args,
2055                               /*isImplicit=*/true);
2056 }
2057 
2058 /// \brief Build an Objective-C instance message expression.
2059 ///
2060 /// This routine takes care of both normal instance messages and
2061 /// instance messages to the superclass instance.
2062 ///
2063 /// \param Receiver The expression that computes the object that will
2064 /// receive this message. This may be empty, in which case we are
2065 /// sending to the superclass instance and \p SuperLoc must be a valid
2066 /// source location.
2067 ///
2068 /// \param ReceiverType The (static) type of the object receiving the
2069 /// message. When a \p Receiver expression is provided, this is the
2070 /// same type as that expression. For a superclass instance send, this
2071 /// is a pointer to the type of the superclass.
2072 ///
2073 /// \param SuperLoc The location of the "super" keyword in a
2074 /// superclass instance message.
2075 ///
2076 /// \param Sel The selector to which the message is being sent.
2077 ///
2078 /// \param Method The method that this instance message is invoking, if
2079 /// already known.
2080 ///
2081 /// \param LBracLoc The location of the opening square bracket ']'.
2082 ///
2083 /// \param RBracLoc The location of the closing square bracket ']'.
2084 ///
2085 /// \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)2086 ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
2087                                       QualType ReceiverType,
2088                                       SourceLocation SuperLoc,
2089                                       Selector Sel,
2090                                       ObjCMethodDecl *Method,
2091                                       SourceLocation LBracLoc,
2092                                       ArrayRef<SourceLocation> SelectorLocs,
2093                                       SourceLocation RBracLoc,
2094                                       MultiExprArg ArgsIn,
2095                                       bool isImplicit) {
2096   // The location of the receiver.
2097   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
2098 
2099   if (LBracLoc.isInvalid()) {
2100     Diag(Loc, diag::err_missing_open_square_message_send)
2101       << FixItHint::CreateInsertion(Loc, "[");
2102     LBracLoc = Loc;
2103   }
2104 
2105   // If we have a receiver expression, perform appropriate promotions
2106   // and determine receiver type.
2107   if (Receiver) {
2108     if (Receiver->hasPlaceholderType()) {
2109       ExprResult Result;
2110       if (Receiver->getType() == Context.UnknownAnyTy)
2111         Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
2112       else
2113         Result = CheckPlaceholderExpr(Receiver);
2114       if (Result.isInvalid()) return ExprError();
2115       Receiver = Result.take();
2116     }
2117 
2118     if (Receiver->isTypeDependent()) {
2119       // If the receiver is type-dependent, we can't type-check anything
2120       // at this point. Build a dependent expression.
2121       unsigned NumArgs = ArgsIn.size();
2122       Expr **Args = ArgsIn.data();
2123       assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2124       return Owned(ObjCMessageExpr::Create(Context, Context.DependentTy,
2125                                            VK_RValue, LBracLoc, Receiver, Sel,
2126                                            SelectorLocs, /*Method=*/0,
2127                                            makeArrayRef(Args, NumArgs),
2128                                            RBracLoc, isImplicit));
2129     }
2130 
2131     // If necessary, apply function/array conversion to the receiver.
2132     // C99 6.7.5.3p[7,8].
2133     ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
2134     if (Result.isInvalid())
2135       return ExprError();
2136     Receiver = Result.take();
2137     ReceiverType = Receiver->getType();
2138 
2139     // If the receiver is an ObjC pointer, a block pointer, or an
2140     // __attribute__((NSObject)) pointer, we don't need to do any
2141     // special conversion in order to look up a receiver.
2142     if (ReceiverType->isObjCRetainableType()) {
2143       // do nothing
2144     } else if (!getLangOpts().ObjCAutoRefCount &&
2145                !Context.getObjCIdType().isNull() &&
2146                (ReceiverType->isPointerType() ||
2147                 ReceiverType->isIntegerType())) {
2148       // Implicitly convert integers and pointers to 'id' but emit a warning.
2149       // But not in ARC.
2150       Diag(Loc, diag::warn_bad_receiver_type)
2151         << ReceiverType
2152         << Receiver->getSourceRange();
2153       if (ReceiverType->isPointerType()) {
2154         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2155                                      CK_CPointerToObjCPointerCast).take();
2156       } else {
2157         // TODO: specialized warning on null receivers?
2158         bool IsNull = Receiver->isNullPointerConstant(Context,
2159                                               Expr::NPC_ValueDependentIsNull);
2160         CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
2161         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2162                                      Kind).take();
2163       }
2164       ReceiverType = Receiver->getType();
2165     } else if (getLangOpts().CPlusPlus) {
2166       ExprResult result = PerformContextuallyConvertToObjCPointer(Receiver);
2167       if (result.isUsable()) {
2168         Receiver = result.take();
2169         ReceiverType = Receiver->getType();
2170       }
2171     }
2172   }
2173 
2174   // There's a somewhat weird interaction here where we assume that we
2175   // won't actually have a method unless we also don't need to do some
2176   // of the more detailed type-checking on the receiver.
2177 
2178   if (!Method) {
2179     // Handle messages to id.
2180     bool receiverIsId = ReceiverType->isObjCIdType();
2181     if (receiverIsId || ReceiverType->isBlockPointerType() ||
2182         (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
2183       Method = LookupInstanceMethodInGlobalPool(Sel,
2184                                                 SourceRange(LBracLoc, RBracLoc),
2185                                                 receiverIsId);
2186       if (!Method)
2187         Method = LookupFactoryMethodInGlobalPool(Sel,
2188                                                  SourceRange(LBracLoc,RBracLoc),
2189                                                  receiverIsId);
2190     } else if (ReceiverType->isObjCClassType() ||
2191                ReceiverType->isObjCQualifiedClassType()) {
2192       // Handle messages to Class.
2193       // We allow sending a message to a qualified Class ("Class<foo>"), which
2194       // is ok as long as one of the protocols implements the selector (if not, warn).
2195       if (const ObjCObjectPointerType *QClassTy
2196             = ReceiverType->getAsObjCQualifiedClassType()) {
2197         // Search protocols for class methods.
2198         Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
2199         if (!Method) {
2200           Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
2201           // warn if instance method found for a Class message.
2202           if (Method) {
2203             Diag(Loc, diag::warn_instance_method_on_class_found)
2204               << Method->getSelector() << Sel;
2205             Diag(Method->getLocation(), diag::note_method_declared_at)
2206               << Method->getDeclName();
2207           }
2208         }
2209       } else {
2210         if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2211           if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
2212             // First check the public methods in the class interface.
2213             Method = ClassDecl->lookupClassMethod(Sel);
2214 
2215             if (!Method)
2216               Method = ClassDecl->lookupPrivateClassMethod(Sel);
2217           }
2218           if (Method && DiagnoseUseOfDecl(Method, Loc))
2219             return ExprError();
2220         }
2221         if (!Method) {
2222           // If not messaging 'self', look for any factory method named 'Sel'.
2223           if (!Receiver || !isSelfExpr(Receiver)) {
2224             Method = LookupFactoryMethodInGlobalPool(Sel,
2225                                                 SourceRange(LBracLoc, RBracLoc),
2226                                                      true);
2227             if (!Method) {
2228               // If no class (factory) method was found, check if an _instance_
2229               // method of the same name exists in the root class only.
2230               Method = LookupInstanceMethodInGlobalPool(Sel,
2231                                                SourceRange(LBracLoc, RBracLoc),
2232                                                         true);
2233               if (Method)
2234                   if (const ObjCInterfaceDecl *ID =
2235                       dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
2236                     if (ID->getSuperClass())
2237                       Diag(Loc, diag::warn_root_inst_method_not_found)
2238                       << Sel << SourceRange(LBracLoc, RBracLoc);
2239                   }
2240             }
2241           }
2242         }
2243       }
2244     } else {
2245       ObjCInterfaceDecl* ClassDecl = 0;
2246 
2247       // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
2248       // long as one of the protocols implements the selector (if not, warn).
2249       // And as long as message is not deprecated/unavailable (warn if it is).
2250       if (const ObjCObjectPointerType *QIdTy
2251                                    = ReceiverType->getAsObjCQualifiedIdType()) {
2252         // Search protocols for instance methods.
2253         Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
2254         if (!Method)
2255           Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
2256         if (Method && DiagnoseUseOfDecl(Method, Loc))
2257           return ExprError();
2258       } else if (const ObjCObjectPointerType *OCIType
2259                    = ReceiverType->getAsObjCInterfacePointerType()) {
2260         // We allow sending a message to a pointer to an interface (an object).
2261         ClassDecl = OCIType->getInterfaceDecl();
2262 
2263         // Try to complete the type. Under ARC, this is a hard error from which
2264         // we don't try to recover.
2265         const ObjCInterfaceDecl *forwardClass = 0;
2266         if (RequireCompleteType(Loc, OCIType->getPointeeType(),
2267               getLangOpts().ObjCAutoRefCount
2268                 ? diag::err_arc_receiver_forward_instance
2269                 : diag::warn_receiver_forward_instance,
2270                                 Receiver? Receiver->getSourceRange()
2271                                         : SourceRange(SuperLoc))) {
2272           if (getLangOpts().ObjCAutoRefCount)
2273             return ExprError();
2274 
2275           forwardClass = OCIType->getInterfaceDecl();
2276           Diag(Receiver ? Receiver->getLocStart()
2277                         : SuperLoc, diag::note_receiver_is_id);
2278           Method = 0;
2279         } else {
2280           Method = ClassDecl->lookupInstanceMethod(Sel);
2281         }
2282 
2283         if (!Method)
2284           // Search protocol qualifiers.
2285           Method = LookupMethodInQualifiedType(Sel, OCIType, true);
2286 
2287         if (!Method) {
2288           // If we have implementations in scope, check "private" methods.
2289           Method = ClassDecl->lookupPrivateMethod(Sel);
2290 
2291           if (!Method && getLangOpts().ObjCAutoRefCount) {
2292             Diag(Loc, diag::err_arc_may_not_respond)
2293               << OCIType->getPointeeType() << Sel
2294               << SourceRange(SelectorLocs.front(), SelectorLocs.back());
2295             return ExprError();
2296           }
2297 
2298           if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
2299             // If we still haven't found a method, look in the global pool. This
2300             // behavior isn't very desirable, however we need it for GCC
2301             // compatibility. FIXME: should we deviate??
2302             if (OCIType->qual_empty()) {
2303               Method = LookupInstanceMethodInGlobalPool(Sel,
2304                                               SourceRange(LBracLoc, RBracLoc));
2305               if (Method && !forwardClass)
2306                 Diag(Loc, diag::warn_maynot_respond)
2307                   << OCIType->getInterfaceDecl()->getIdentifier() << Sel;
2308             }
2309           }
2310         }
2311         if (Method && DiagnoseUseOfDecl(Method, Loc, forwardClass))
2312           return ExprError();
2313       } else {
2314         // Reject other random receiver types (e.g. structs).
2315         Diag(Loc, diag::err_bad_receiver_type)
2316           << ReceiverType << Receiver->getSourceRange();
2317         return ExprError();
2318       }
2319     }
2320   }
2321 
2322   // Check the message arguments.
2323   unsigned NumArgs = ArgsIn.size();
2324   Expr **Args = ArgsIn.data();
2325   QualType ReturnType;
2326   ExprValueKind VK = VK_RValue;
2327   bool ClassMessage = (ReceiverType->isObjCClassType() ||
2328                        ReceiverType->isObjCQualifiedClassType());
2329   if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel,
2330                                 SelectorLocs, Method,
2331                                 ClassMessage, SuperLoc.isValid(),
2332                                 LBracLoc, RBracLoc, ReturnType, VK))
2333     return ExprError();
2334 
2335   if (Method && !Method->getResultType()->isVoidType() &&
2336       RequireCompleteType(LBracLoc, Method->getResultType(),
2337                           diag::err_illegal_message_expr_incomplete_type))
2338     return ExprError();
2339 
2340   SourceLocation SelLoc = SelectorLocs.front();
2341 
2342   // In ARC, forbid the user from sending messages to
2343   // retain/release/autorelease/dealloc/retainCount explicitly.
2344   if (getLangOpts().ObjCAutoRefCount) {
2345     ObjCMethodFamily family =
2346       (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
2347     switch (family) {
2348     case OMF_init:
2349       if (Method)
2350         checkInitMethod(Method, ReceiverType);
2351 
2352     case OMF_None:
2353     case OMF_alloc:
2354     case OMF_copy:
2355     case OMF_finalize:
2356     case OMF_mutableCopy:
2357     case OMF_new:
2358     case OMF_self:
2359       break;
2360 
2361     case OMF_dealloc:
2362     case OMF_retain:
2363     case OMF_release:
2364     case OMF_autorelease:
2365     case OMF_retainCount:
2366       Diag(Loc, diag::err_arc_illegal_explicit_message)
2367         << Sel << SelLoc;
2368       break;
2369 
2370     case OMF_performSelector:
2371       if (Method && NumArgs >= 1) {
2372         if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
2373           Selector ArgSel = SelExp->getSelector();
2374           ObjCMethodDecl *SelMethod =
2375             LookupInstanceMethodInGlobalPool(ArgSel,
2376                                              SelExp->getSourceRange());
2377           if (!SelMethod)
2378             SelMethod =
2379               LookupFactoryMethodInGlobalPool(ArgSel,
2380                                               SelExp->getSourceRange());
2381           if (SelMethod) {
2382             ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
2383             switch (SelFamily) {
2384               case OMF_alloc:
2385               case OMF_copy:
2386               case OMF_mutableCopy:
2387               case OMF_new:
2388               case OMF_self:
2389               case OMF_init:
2390                 // Issue error, unless ns_returns_not_retained.
2391                 if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
2392                   // selector names a +1 method
2393                   Diag(SelLoc,
2394                        diag::err_arc_perform_selector_retains);
2395                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2396                     << SelMethod->getDeclName();
2397                 }
2398                 break;
2399               default:
2400                 // +0 call. OK. unless ns_returns_retained.
2401                 if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
2402                   // selector names a +1 method
2403                   Diag(SelLoc,
2404                        diag::err_arc_perform_selector_retains);
2405                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2406                     << SelMethod->getDeclName();
2407                 }
2408                 break;
2409             }
2410           }
2411         } else {
2412           // error (may leak).
2413           Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
2414           Diag(Args[0]->getExprLoc(), diag::note_used_here);
2415         }
2416       }
2417       break;
2418     }
2419   }
2420 
2421   // Construct the appropriate ObjCMessageExpr instance.
2422   ObjCMessageExpr *Result;
2423   if (SuperLoc.isValid())
2424     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2425                                      SuperLoc,  /*IsInstanceSuper=*/true,
2426                                      ReceiverType, Sel, SelectorLocs, Method,
2427                                      makeArrayRef(Args, NumArgs), RBracLoc,
2428                                      isImplicit);
2429   else {
2430     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2431                                      Receiver, Sel, SelectorLocs, Method,
2432                                      makeArrayRef(Args, NumArgs), RBracLoc,
2433                                      isImplicit);
2434     if (!isImplicit)
2435       checkCocoaAPI(*this, Result);
2436   }
2437 
2438   if (getLangOpts().ObjCAutoRefCount) {
2439     DiagnoseARCUseOfWeakReceiver(*this, Receiver);
2440 
2441     // In ARC, annotate delegate init calls.
2442     if (Result->getMethodFamily() == OMF_init &&
2443         (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2444       // Only consider init calls *directly* in init implementations,
2445       // not within blocks.
2446       ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
2447       if (method && method->getMethodFamily() == OMF_init) {
2448         // The implicit assignment to self means we also don't want to
2449         // consume the result.
2450         Result->setDelegateInitCall(true);
2451         return Owned(Result);
2452       }
2453     }
2454 
2455     // In ARC, check for message sends which are likely to introduce
2456     // retain cycles.
2457     checkRetainCycles(Result);
2458 
2459     if (!isImplicit && Method) {
2460       if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
2461         bool IsWeak =
2462           Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
2463         if (!IsWeak && Sel.isUnarySelector())
2464           IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
2465 
2466         if (IsWeak) {
2467           DiagnosticsEngine::Level Level =
2468             Diags.getDiagnosticLevel(diag::warn_arc_repeated_use_of_weak,
2469                                      LBracLoc);
2470           if (Level != DiagnosticsEngine::Ignored)
2471             getCurFunction()->recordUseOfWeak(Result, Prop);
2472 
2473         }
2474       }
2475     }
2476   }
2477 
2478   return MaybeBindToTemporary(Result);
2479 }
2480 
RemoveSelectorFromWarningCache(Sema & S,Expr * Arg)2481 static void RemoveSelectorFromWarningCache(Sema &S, Expr* Arg) {
2482   if (ObjCSelectorExpr *OSE =
2483       dyn_cast<ObjCSelectorExpr>(Arg->IgnoreParenCasts())) {
2484     Selector Sel = OSE->getSelector();
2485     SourceLocation Loc = OSE->getAtLoc();
2486     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
2487     = S.ReferencedSelectors.find(Sel);
2488     if (Pos != S.ReferencedSelectors.end() && Pos->second == Loc)
2489       S.ReferencedSelectors.erase(Pos);
2490   }
2491 }
2492 
2493 // ActOnInstanceMessage - used for both unary and keyword messages.
2494 // ArgExprs is optional - if it is present, the number of expressions
2495 // is obtained from Sel.getNumArgs().
ActOnInstanceMessage(Scope * S,Expr * Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2496 ExprResult Sema::ActOnInstanceMessage(Scope *S,
2497                                       Expr *Receiver,
2498                                       Selector Sel,
2499                                       SourceLocation LBracLoc,
2500                                       ArrayRef<SourceLocation> SelectorLocs,
2501                                       SourceLocation RBracLoc,
2502                                       MultiExprArg Args) {
2503   if (!Receiver)
2504     return ExprError();
2505 
2506   // A ParenListExpr can show up while doing error recovery with invalid code.
2507   if (isa<ParenListExpr>(Receiver)) {
2508     ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Receiver);
2509     if (Result.isInvalid()) return ExprError();
2510     Receiver = Result.take();
2511   }
2512 
2513   if (RespondsToSelectorSel.isNull()) {
2514     IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
2515     RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
2516   }
2517   if (Sel == RespondsToSelectorSel)
2518     RemoveSelectorFromWarningCache(*this, Args[0]);
2519 
2520   return BuildInstanceMessage(Receiver, Receiver->getType(),
2521                               /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
2522                               LBracLoc, SelectorLocs, RBracLoc, Args);
2523 }
2524 
2525 enum ARCConversionTypeClass {
2526   /// int, void, struct A
2527   ACTC_none,
2528 
2529   /// id, void (^)()
2530   ACTC_retainable,
2531 
2532   /// id*, id***, void (^*)(),
2533   ACTC_indirectRetainable,
2534 
2535   /// void* might be a normal C type, or it might a CF type.
2536   ACTC_voidPtr,
2537 
2538   /// struct A*
2539   ACTC_coreFoundation
2540 };
isAnyRetainable(ARCConversionTypeClass ACTC)2541 static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
2542   return (ACTC == ACTC_retainable ||
2543           ACTC == ACTC_coreFoundation ||
2544           ACTC == ACTC_voidPtr);
2545 }
isAnyCLike(ARCConversionTypeClass ACTC)2546 static bool isAnyCLike(ARCConversionTypeClass ACTC) {
2547   return ACTC == ACTC_none ||
2548          ACTC == ACTC_voidPtr ||
2549          ACTC == ACTC_coreFoundation;
2550 }
2551 
classifyTypeForARCConversion(QualType type)2552 static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
2553   bool isIndirect = false;
2554 
2555   // Ignore an outermost reference type.
2556   if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
2557     type = ref->getPointeeType();
2558     isIndirect = true;
2559   }
2560 
2561   // Drill through pointers and arrays recursively.
2562   while (true) {
2563     if (const PointerType *ptr = type->getAs<PointerType>()) {
2564       type = ptr->getPointeeType();
2565 
2566       // The first level of pointer may be the innermost pointer on a CF type.
2567       if (!isIndirect) {
2568         if (type->isVoidType()) return ACTC_voidPtr;
2569         if (type->isRecordType()) return ACTC_coreFoundation;
2570       }
2571     } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
2572       type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
2573     } else {
2574       break;
2575     }
2576     isIndirect = true;
2577   }
2578 
2579   if (isIndirect) {
2580     if (type->isObjCARCBridgableType())
2581       return ACTC_indirectRetainable;
2582     return ACTC_none;
2583   }
2584 
2585   if (type->isObjCARCBridgableType())
2586     return ACTC_retainable;
2587 
2588   return ACTC_none;
2589 }
2590 
2591 namespace {
2592   /// A result from the cast checker.
2593   enum ACCResult {
2594     /// Cannot be casted.
2595     ACC_invalid,
2596 
2597     /// Can be safely retained or not retained.
2598     ACC_bottom,
2599 
2600     /// Can be casted at +0.
2601     ACC_plusZero,
2602 
2603     /// Can be casted at +1.
2604     ACC_plusOne
2605   };
merge(ACCResult left,ACCResult right)2606   ACCResult merge(ACCResult left, ACCResult right) {
2607     if (left == right) return left;
2608     if (left == ACC_bottom) return right;
2609     if (right == ACC_bottom) return left;
2610     return ACC_invalid;
2611   }
2612 
2613   /// A checker which white-lists certain expressions whose conversion
2614   /// to or from retainable type would otherwise be forbidden in ARC.
2615   class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
2616     typedef StmtVisitor<ARCCastChecker, ACCResult> super;
2617 
2618     ASTContext &Context;
2619     ARCConversionTypeClass SourceClass;
2620     ARCConversionTypeClass TargetClass;
2621     bool Diagnose;
2622 
isCFType(QualType type)2623     static bool isCFType(QualType type) {
2624       // Someday this can use ns_bridged.  For now, it has to do this.
2625       return type->isCARCBridgableType();
2626     }
2627 
2628   public:
ARCCastChecker(ASTContext & Context,ARCConversionTypeClass source,ARCConversionTypeClass target,bool diagnose)2629     ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
2630                    ARCConversionTypeClass target, bool diagnose)
2631       : Context(Context), SourceClass(source), TargetClass(target),
2632         Diagnose(diagnose) {}
2633 
2634     using super::Visit;
Visit(Expr * e)2635     ACCResult Visit(Expr *e) {
2636       return super::Visit(e->IgnoreParens());
2637     }
2638 
VisitStmt(Stmt * s)2639     ACCResult VisitStmt(Stmt *s) {
2640       return ACC_invalid;
2641     }
2642 
2643     /// Null pointer constants can be casted however you please.
VisitExpr(Expr * e)2644     ACCResult VisitExpr(Expr *e) {
2645       if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
2646         return ACC_bottom;
2647       return ACC_invalid;
2648     }
2649 
2650     /// Objective-C string literals can be safely casted.
VisitObjCStringLiteral(ObjCStringLiteral * e)2651     ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
2652       // If we're casting to any retainable type, go ahead.  Global
2653       // strings are immune to retains, so this is bottom.
2654       if (isAnyRetainable(TargetClass)) return ACC_bottom;
2655 
2656       return ACC_invalid;
2657     }
2658 
2659     /// Look through certain implicit and explicit casts.
VisitCastExpr(CastExpr * e)2660     ACCResult VisitCastExpr(CastExpr *e) {
2661       switch (e->getCastKind()) {
2662         case CK_NullToPointer:
2663           return ACC_bottom;
2664 
2665         case CK_NoOp:
2666         case CK_LValueToRValue:
2667         case CK_BitCast:
2668         case CK_CPointerToObjCPointerCast:
2669         case CK_BlockPointerToObjCPointerCast:
2670         case CK_AnyPointerToBlockPointerCast:
2671           return Visit(e->getSubExpr());
2672 
2673         default:
2674           return ACC_invalid;
2675       }
2676     }
2677 
2678     /// Look through unary extension.
VisitUnaryExtension(UnaryOperator * e)2679     ACCResult VisitUnaryExtension(UnaryOperator *e) {
2680       return Visit(e->getSubExpr());
2681     }
2682 
2683     /// Ignore the LHS of a comma operator.
VisitBinComma(BinaryOperator * e)2684     ACCResult VisitBinComma(BinaryOperator *e) {
2685       return Visit(e->getRHS());
2686     }
2687 
2688     /// Conditional operators are okay if both sides are okay.
VisitConditionalOperator(ConditionalOperator * e)2689     ACCResult VisitConditionalOperator(ConditionalOperator *e) {
2690       ACCResult left = Visit(e->getTrueExpr());
2691       if (left == ACC_invalid) return ACC_invalid;
2692       return merge(left, Visit(e->getFalseExpr()));
2693     }
2694 
2695     /// Look through pseudo-objects.
VisitPseudoObjectExpr(PseudoObjectExpr * e)2696     ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
2697       // If we're getting here, we should always have a result.
2698       return Visit(e->getResultExpr());
2699     }
2700 
2701     /// Statement expressions are okay if their result expression is okay.
VisitStmtExpr(StmtExpr * e)2702     ACCResult VisitStmtExpr(StmtExpr *e) {
2703       return Visit(e->getSubStmt()->body_back());
2704     }
2705 
2706     /// Some declaration references are okay.
VisitDeclRefExpr(DeclRefExpr * e)2707     ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
2708       // References to global constants from system headers are okay.
2709       // These are things like 'kCFStringTransformToLatin'.  They are
2710       // can also be assumed to be immune to retains.
2711       VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
2712       if (isAnyRetainable(TargetClass) &&
2713           isAnyRetainable(SourceClass) &&
2714           var &&
2715           var->getStorageClass() == SC_Extern &&
2716           var->getType().isConstQualified() &&
2717           Context.getSourceManager().isInSystemHeader(var->getLocation())) {
2718         return ACC_bottom;
2719       }
2720 
2721       // Nothing else.
2722       return ACC_invalid;
2723     }
2724 
2725     /// Some calls are okay.
VisitCallExpr(CallExpr * e)2726     ACCResult VisitCallExpr(CallExpr *e) {
2727       if (FunctionDecl *fn = e->getDirectCallee())
2728         if (ACCResult result = checkCallToFunction(fn))
2729           return result;
2730 
2731       return super::VisitCallExpr(e);
2732     }
2733 
checkCallToFunction(FunctionDecl * fn)2734     ACCResult checkCallToFunction(FunctionDecl *fn) {
2735       // Require a CF*Ref return type.
2736       if (!isCFType(fn->getResultType()))
2737         return ACC_invalid;
2738 
2739       if (!isAnyRetainable(TargetClass))
2740         return ACC_invalid;
2741 
2742       // Honor an explicit 'not retained' attribute.
2743       if (fn->hasAttr<CFReturnsNotRetainedAttr>())
2744         return ACC_plusZero;
2745 
2746       // Honor an explicit 'retained' attribute, except that for
2747       // now we're not going to permit implicit handling of +1 results,
2748       // because it's a bit frightening.
2749       if (fn->hasAttr<CFReturnsRetainedAttr>())
2750         return Diagnose ? ACC_plusOne
2751                         : ACC_invalid; // ACC_plusOne if we start accepting this
2752 
2753       // Recognize this specific builtin function, which is used by CFSTR.
2754       unsigned builtinID = fn->getBuiltinID();
2755       if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
2756         return ACC_bottom;
2757 
2758       // Otherwise, don't do anything implicit with an unaudited function.
2759       if (!fn->hasAttr<CFAuditedTransferAttr>())
2760         return ACC_invalid;
2761 
2762       // Otherwise, it's +0 unless it follows the create convention.
2763       if (ento::coreFoundation::followsCreateRule(fn))
2764         return Diagnose ? ACC_plusOne
2765                         : ACC_invalid; // ACC_plusOne if we start accepting this
2766 
2767       return ACC_plusZero;
2768     }
2769 
VisitObjCMessageExpr(ObjCMessageExpr * e)2770     ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
2771       return checkCallToMethod(e->getMethodDecl());
2772     }
2773 
VisitObjCPropertyRefExpr(ObjCPropertyRefExpr * e)2774     ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
2775       ObjCMethodDecl *method;
2776       if (e->isExplicitProperty())
2777         method = e->getExplicitProperty()->getGetterMethodDecl();
2778       else
2779         method = e->getImplicitPropertyGetter();
2780       return checkCallToMethod(method);
2781     }
2782 
checkCallToMethod(ObjCMethodDecl * method)2783     ACCResult checkCallToMethod(ObjCMethodDecl *method) {
2784       if (!method) return ACC_invalid;
2785 
2786       // Check for message sends to functions returning CF types.  We
2787       // just obey the Cocoa conventions with these, even though the
2788       // return type is CF.
2789       if (!isAnyRetainable(TargetClass) || !isCFType(method->getResultType()))
2790         return ACC_invalid;
2791 
2792       // If the method is explicitly marked not-retained, it's +0.
2793       if (method->hasAttr<CFReturnsNotRetainedAttr>())
2794         return ACC_plusZero;
2795 
2796       // If the method is explicitly marked as returning retained, or its
2797       // selector follows a +1 Cocoa convention, treat it as +1.
2798       if (method->hasAttr<CFReturnsRetainedAttr>())
2799         return ACC_plusOne;
2800 
2801       switch (method->getSelector().getMethodFamily()) {
2802       case OMF_alloc:
2803       case OMF_copy:
2804       case OMF_mutableCopy:
2805       case OMF_new:
2806         return ACC_plusOne;
2807 
2808       default:
2809         // Otherwise, treat it as +0.
2810         return ACC_plusZero;
2811       }
2812     }
2813   };
2814 }
2815 
isKnownName(StringRef name)2816 bool Sema::isKnownName(StringRef name) {
2817   if (name.empty())
2818     return false;
2819   LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
2820                  Sema::LookupOrdinaryName);
2821   return LookupName(R, TUScope, false);
2822 }
2823 
addFixitForObjCARCConversion(Sema & S,DiagnosticBuilder & DiagB,Sema::CheckedConversionKind CCK,SourceLocation afterLParen,QualType castType,Expr * castExpr,Expr * realCast,const char * bridgeKeyword,const char * CFBridgeName)2824 static void addFixitForObjCARCConversion(Sema &S,
2825                                          DiagnosticBuilder &DiagB,
2826                                          Sema::CheckedConversionKind CCK,
2827                                          SourceLocation afterLParen,
2828                                          QualType castType,
2829                                          Expr *castExpr,
2830                                          Expr *realCast,
2831                                          const char *bridgeKeyword,
2832                                          const char *CFBridgeName) {
2833   // We handle C-style and implicit casts here.
2834   switch (CCK) {
2835   case Sema::CCK_ImplicitConversion:
2836   case Sema::CCK_CStyleCast:
2837   case Sema::CCK_OtherCast:
2838     break;
2839   case Sema::CCK_FunctionalCast:
2840     return;
2841   }
2842 
2843   if (CFBridgeName) {
2844     if (CCK == Sema::CCK_OtherCast) {
2845       if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
2846         SourceRange range(NCE->getOperatorLoc(),
2847                           NCE->getAngleBrackets().getEnd());
2848         SmallString<32> BridgeCall;
2849 
2850         SourceManager &SM = S.getSourceManager();
2851         char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
2852         if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
2853           BridgeCall += ' ';
2854 
2855         BridgeCall += CFBridgeName;
2856         DiagB.AddFixItHint(FixItHint::CreateReplacement(range, BridgeCall));
2857       }
2858       return;
2859     }
2860     Expr *castedE = castExpr;
2861     if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
2862       castedE = CCE->getSubExpr();
2863     castedE = castedE->IgnoreImpCasts();
2864     SourceRange range = castedE->getSourceRange();
2865 
2866     SmallString<32> BridgeCall;
2867 
2868     SourceManager &SM = S.getSourceManager();
2869     char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
2870     if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
2871       BridgeCall += ' ';
2872 
2873     BridgeCall += CFBridgeName;
2874 
2875     if (isa<ParenExpr>(castedE)) {
2876       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2877                          BridgeCall));
2878     } else {
2879       BridgeCall += '(';
2880       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2881                                                     BridgeCall));
2882       DiagB.AddFixItHint(FixItHint::CreateInsertion(
2883                                        S.PP.getLocForEndOfToken(range.getEnd()),
2884                                        ")"));
2885     }
2886     return;
2887   }
2888 
2889   if (CCK == Sema::CCK_CStyleCast) {
2890     DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
2891   } else if (CCK == Sema::CCK_OtherCast) {
2892     if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
2893       std::string castCode = "(";
2894       castCode += bridgeKeyword;
2895       castCode += castType.getAsString();
2896       castCode += ")";
2897       SourceRange Range(NCE->getOperatorLoc(),
2898                         NCE->getAngleBrackets().getEnd());
2899       DiagB.AddFixItHint(FixItHint::CreateReplacement(Range, castCode));
2900     }
2901   } else {
2902     std::string castCode = "(";
2903     castCode += bridgeKeyword;
2904     castCode += castType.getAsString();
2905     castCode += ")";
2906     Expr *castedE = castExpr->IgnoreImpCasts();
2907     SourceRange range = castedE->getSourceRange();
2908     if (isa<ParenExpr>(castedE)) {
2909       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2910                          castCode));
2911     } else {
2912       castCode += "(";
2913       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
2914                                                     castCode));
2915       DiagB.AddFixItHint(FixItHint::CreateInsertion(
2916                                        S.PP.getLocForEndOfToken(range.getEnd()),
2917                                        ")"));
2918     }
2919   }
2920 }
2921 
2922 static void
diagnoseObjCARCConversion(Sema & S,SourceRange castRange,QualType castType,ARCConversionTypeClass castACTC,Expr * castExpr,Expr * realCast,ARCConversionTypeClass exprACTC,Sema::CheckedConversionKind CCK)2923 diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
2924                           QualType castType, ARCConversionTypeClass castACTC,
2925                           Expr *castExpr, Expr *realCast,
2926                           ARCConversionTypeClass exprACTC,
2927                           Sema::CheckedConversionKind CCK) {
2928   SourceLocation loc =
2929     (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
2930 
2931   if (S.makeUnavailableInSystemHeader(loc,
2932                 "converts between Objective-C and C pointers in -fobjc-arc"))
2933     return;
2934 
2935   QualType castExprType = castExpr->getType();
2936 
2937   unsigned srcKind = 0;
2938   switch (exprACTC) {
2939   case ACTC_none:
2940   case ACTC_coreFoundation:
2941   case ACTC_voidPtr:
2942     srcKind = (castExprType->isPointerType() ? 1 : 0);
2943     break;
2944   case ACTC_retainable:
2945     srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
2946     break;
2947   case ACTC_indirectRetainable:
2948     srcKind = 4;
2949     break;
2950   }
2951 
2952   // Check whether this could be fixed with a bridge cast.
2953   SourceLocation afterLParen = S.PP.getLocForEndOfToken(castRange.getBegin());
2954   SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
2955 
2956   // Bridge from an ARC type to a CF type.
2957   if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
2958 
2959     S.Diag(loc, diag::err_arc_cast_requires_bridge)
2960       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
2961       << 2 // of C pointer type
2962       << castExprType
2963       << unsigned(castType->isBlockPointerType()) // to ObjC|block type
2964       << castType
2965       << castRange
2966       << castExpr->getSourceRange();
2967     bool br = S.isKnownName("CFBridgingRelease");
2968     ACCResult CreateRule =
2969       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
2970     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
2971     if (CreateRule != ACC_plusOne)
2972     {
2973       DiagnosticBuilder DiagB =
2974         (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
2975                               : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
2976 
2977       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2978                                    castType, castExpr, realCast, "__bridge ", 0);
2979     }
2980     if (CreateRule != ACC_plusZero)
2981     {
2982       DiagnosticBuilder DiagB =
2983         (CCK == Sema::CCK_OtherCast && !br) ?
2984           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_transfer) << castExprType :
2985           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
2986                  diag::note_arc_bridge_transfer)
2987             << castExprType << br;
2988 
2989       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
2990                                    castType, castExpr, realCast, "__bridge_transfer ",
2991                                    br ? "CFBridgingRelease" : 0);
2992     }
2993 
2994     return;
2995   }
2996 
2997   // Bridge from a CF type to an ARC type.
2998   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
2999     bool br = S.isKnownName("CFBridgingRetain");
3000     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3001       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3002       << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
3003       << castExprType
3004       << 2 // to C pointer type
3005       << castType
3006       << castRange
3007       << castExpr->getSourceRange();
3008     ACCResult CreateRule =
3009       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3010     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3011     if (CreateRule != ACC_plusOne)
3012     {
3013       DiagnosticBuilder DiagB =
3014       (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3015                                : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3016       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3017                                    castType, castExpr, realCast, "__bridge ", 0);
3018     }
3019     if (CreateRule != ACC_plusZero)
3020     {
3021       DiagnosticBuilder DiagB =
3022         (CCK == Sema::CCK_OtherCast && !br) ?
3023           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_retained) << castType :
3024           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3025                  diag::note_arc_bridge_retained)
3026             << castType << br;
3027 
3028       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3029                                    castType, castExpr, realCast, "__bridge_retained ",
3030                                    br ? "CFBridgingRetain" : 0);
3031     }
3032 
3033     return;
3034   }
3035 
3036   S.Diag(loc, diag::err_arc_mismatched_cast)
3037     << (CCK != Sema::CCK_ImplicitConversion)
3038     << srcKind << castExprType << castType
3039     << castRange << castExpr->getSourceRange();
3040 }
3041 
3042 Sema::ARCConversionResult
CheckObjCARCConversion(SourceRange castRange,QualType castType,Expr * & castExpr,CheckedConversionKind CCK)3043 Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
3044                              Expr *&castExpr, CheckedConversionKind CCK) {
3045   QualType castExprType = castExpr->getType();
3046 
3047   // For the purposes of the classification, we assume reference types
3048   // will bind to temporaries.
3049   QualType effCastType = castType;
3050   if (const ReferenceType *ref = castType->getAs<ReferenceType>())
3051     effCastType = ref->getPointeeType();
3052 
3053   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
3054   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
3055   if (exprACTC == castACTC) {
3056     // check for viablity and report error if casting an rvalue to a
3057     // life-time qualifier.
3058     if ((castACTC == ACTC_retainable) &&
3059         (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
3060         (castType != castExprType)) {
3061       const Type *DT = castType.getTypePtr();
3062       QualType QDT = castType;
3063       // We desugar some types but not others. We ignore those
3064       // that cannot happen in a cast; i.e. auto, and those which
3065       // should not be de-sugared; i.e typedef.
3066       if (const ParenType *PT = dyn_cast<ParenType>(DT))
3067         QDT = PT->desugar();
3068       else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
3069         QDT = TP->desugar();
3070       else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
3071         QDT = AT->desugar();
3072       if (QDT != castType &&
3073           QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
3074         SourceLocation loc =
3075           (castRange.isValid() ? castRange.getBegin()
3076                               : castExpr->getExprLoc());
3077         Diag(loc, diag::err_arc_nolifetime_behavior);
3078       }
3079     }
3080     return ACR_okay;
3081   }
3082 
3083   if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
3084 
3085   // Allow all of these types to be cast to integer types (but not
3086   // vice-versa).
3087   if (castACTC == ACTC_none && castType->isIntegralType(Context))
3088     return ACR_okay;
3089 
3090   // Allow casts between pointers to lifetime types (e.g., __strong id*)
3091   // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
3092   // must be explicit.
3093   if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
3094     return ACR_okay;
3095   if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
3096       CCK != CCK_ImplicitConversion)
3097     return ACR_okay;
3098 
3099   switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
3100   // For invalid casts, fall through.
3101   case ACC_invalid:
3102     break;
3103 
3104   // Do nothing for both bottom and +0.
3105   case ACC_bottom:
3106   case ACC_plusZero:
3107     return ACR_okay;
3108 
3109   // If the result is +1, consume it here.
3110   case ACC_plusOne:
3111     castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
3112                                         CK_ARCConsumeObject, castExpr,
3113                                         0, VK_RValue);
3114     ExprNeedsCleanups = true;
3115     return ACR_okay;
3116   }
3117 
3118   // If this is a non-implicit cast from id or block type to a
3119   // CoreFoundation type, delay complaining in case the cast is used
3120   // in an acceptable context.
3121   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
3122       CCK != CCK_ImplicitConversion)
3123     return ACR_unbridged;
3124 
3125   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3126                             castExpr, castExpr, exprACTC, CCK);
3127   return ACR_okay;
3128 }
3129 
3130 /// Given that we saw an expression with the ARCUnbridgedCastTy
3131 /// placeholder type, complain bitterly.
diagnoseARCUnbridgedCast(Expr * e)3132 void Sema::diagnoseARCUnbridgedCast(Expr *e) {
3133   // We expect the spurious ImplicitCastExpr to already have been stripped.
3134   assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3135   CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
3136 
3137   SourceRange castRange;
3138   QualType castType;
3139   CheckedConversionKind CCK;
3140 
3141   if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
3142     castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
3143     castType = cast->getTypeAsWritten();
3144     CCK = CCK_CStyleCast;
3145   } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
3146     castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
3147     castType = cast->getTypeAsWritten();
3148     CCK = CCK_OtherCast;
3149   } else {
3150     castType = cast->getType();
3151     CCK = CCK_ImplicitConversion;
3152   }
3153 
3154   ARCConversionTypeClass castACTC =
3155     classifyTypeForARCConversion(castType.getNonReferenceType());
3156 
3157   Expr *castExpr = realCast->getSubExpr();
3158   assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
3159 
3160   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3161                             castExpr, realCast, ACTC_retainable, CCK);
3162 }
3163 
3164 /// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
3165 /// type, remove the placeholder cast.
stripARCUnbridgedCast(Expr * e)3166 Expr *Sema::stripARCUnbridgedCast(Expr *e) {
3167   assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3168 
3169   if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
3170     Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
3171     return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
3172   } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
3173     assert(uo->getOpcode() == UO_Extension);
3174     Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
3175     return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
3176                                    sub->getValueKind(), sub->getObjectKind(),
3177                                        uo->getOperatorLoc());
3178   } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
3179     assert(!gse->isResultDependent());
3180 
3181     unsigned n = gse->getNumAssocs();
3182     SmallVector<Expr*, 4> subExprs(n);
3183     SmallVector<TypeSourceInfo*, 4> subTypes(n);
3184     for (unsigned i = 0; i != n; ++i) {
3185       subTypes[i] = gse->getAssocTypeSourceInfo(i);
3186       Expr *sub = gse->getAssocExpr(i);
3187       if (i == gse->getResultIndex())
3188         sub = stripARCUnbridgedCast(sub);
3189       subExprs[i] = sub;
3190     }
3191 
3192     return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
3193                                               gse->getControllingExpr(),
3194                                               subTypes, subExprs,
3195                                               gse->getDefaultLoc(),
3196                                               gse->getRParenLoc(),
3197                                        gse->containsUnexpandedParameterPack(),
3198                                               gse->getResultIndex());
3199   } else {
3200     assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
3201     return cast<ImplicitCastExpr>(e)->getSubExpr();
3202   }
3203 }
3204 
CheckObjCARCUnavailableWeakConversion(QualType castType,QualType exprType)3205 bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
3206                                                  QualType exprType) {
3207   QualType canCastType =
3208     Context.getCanonicalType(castType).getUnqualifiedType();
3209   QualType canExprType =
3210     Context.getCanonicalType(exprType).getUnqualifiedType();
3211   if (isa<ObjCObjectPointerType>(canCastType) &&
3212       castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
3213       canExprType->isObjCObjectPointerType()) {
3214     if (const ObjCObjectPointerType *ObjT =
3215         canExprType->getAs<ObjCObjectPointerType>())
3216       if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
3217         return !ObjI->isArcWeakrefUnavailable();
3218   }
3219   return true;
3220 }
3221 
3222 /// Look for an ObjCReclaimReturnedObject cast and destroy it.
maybeUndoReclaimObject(Expr * e)3223 static Expr *maybeUndoReclaimObject(Expr *e) {
3224   // For now, we just undo operands that are *immediately* reclaim
3225   // expressions, which prevents the vast majority of potential
3226   // problems here.  To catch them all, we'd need to rebuild arbitrary
3227   // value-propagating subexpressions --- we can't reliably rebuild
3228   // in-place because of expression sharing.
3229   if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3230     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
3231       return ice->getSubExpr();
3232 
3233   return e;
3234 }
3235 
BuildObjCBridgedCast(SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,TypeSourceInfo * TSInfo,Expr * SubExpr)3236 ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
3237                                       ObjCBridgeCastKind Kind,
3238                                       SourceLocation BridgeKeywordLoc,
3239                                       TypeSourceInfo *TSInfo,
3240                                       Expr *SubExpr) {
3241   ExprResult SubResult = UsualUnaryConversions(SubExpr);
3242   if (SubResult.isInvalid()) return ExprError();
3243   SubExpr = SubResult.take();
3244 
3245   QualType T = TSInfo->getType();
3246   QualType FromType = SubExpr->getType();
3247 
3248   CastKind CK;
3249 
3250   bool MustConsume = false;
3251   if (T->isDependentType() || SubExpr->isTypeDependent()) {
3252     // Okay: we'll build a dependent expression type.
3253     CK = CK_Dependent;
3254   } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
3255     // Casting CF -> id
3256     CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
3257                                   : CK_CPointerToObjCPointerCast);
3258     switch (Kind) {
3259     case OBC_Bridge:
3260       break;
3261 
3262     case OBC_BridgeRetained: {
3263       bool br = isKnownName("CFBridgingRelease");
3264       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3265         << 2
3266         << FromType
3267         << (T->isBlockPointerType()? 1 : 0)
3268         << T
3269         << SubExpr->getSourceRange()
3270         << Kind;
3271       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3272         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
3273       Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
3274         << FromType << br
3275         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3276                                         br ? "CFBridgingRelease "
3277                                            : "__bridge_transfer ");
3278 
3279       Kind = OBC_Bridge;
3280       break;
3281     }
3282 
3283     case OBC_BridgeTransfer:
3284       // We must consume the Objective-C object produced by the cast.
3285       MustConsume = true;
3286       break;
3287     }
3288   } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
3289     // Okay: id -> CF
3290     CK = CK_BitCast;
3291     switch (Kind) {
3292     case OBC_Bridge:
3293       // Reclaiming a value that's going to be __bridge-casted to CF
3294       // is very dangerous, so we don't do it.
3295       SubExpr = maybeUndoReclaimObject(SubExpr);
3296       break;
3297 
3298     case OBC_BridgeRetained:
3299       // Produce the object before casting it.
3300       SubExpr = ImplicitCastExpr::Create(Context, FromType,
3301                                          CK_ARCProduceObject,
3302                                          SubExpr, 0, VK_RValue);
3303       break;
3304 
3305     case OBC_BridgeTransfer: {
3306       bool br = isKnownName("CFBridgingRetain");
3307       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3308         << (FromType->isBlockPointerType()? 1 : 0)
3309         << FromType
3310         << 2
3311         << T
3312         << SubExpr->getSourceRange()
3313         << Kind;
3314 
3315       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3316         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
3317       Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
3318         << T << br
3319         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3320                           br ? "CFBridgingRetain " : "__bridge_retained");
3321 
3322       Kind = OBC_Bridge;
3323       break;
3324     }
3325     }
3326   } else {
3327     Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
3328       << FromType << T << Kind
3329       << SubExpr->getSourceRange()
3330       << TSInfo->getTypeLoc().getSourceRange();
3331     return ExprError();
3332   }
3333 
3334   Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
3335                                                    BridgeKeywordLoc,
3336                                                    TSInfo, SubExpr);
3337 
3338   if (MustConsume) {
3339     ExprNeedsCleanups = true;
3340     Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
3341                                       0, VK_RValue);
3342   }
3343 
3344   return Result;
3345 }
3346 
ActOnObjCBridgedCast(Scope * S,SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,ParsedType Type,SourceLocation RParenLoc,Expr * SubExpr)3347 ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
3348                                       SourceLocation LParenLoc,
3349                                       ObjCBridgeCastKind Kind,
3350                                       SourceLocation BridgeKeywordLoc,
3351                                       ParsedType Type,
3352                                       SourceLocation RParenLoc,
3353                                       Expr *SubExpr) {
3354   TypeSourceInfo *TSInfo = 0;
3355   QualType T = GetTypeFromParser(Type, &TSInfo);
3356   if (!TSInfo)
3357     TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
3358   return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
3359                               SubExpr);
3360 }
3361