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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     const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType());
71     assert(CAT && "String literal not of constant array type!");
72     QualType StrTy = Context.getConstantArrayType(
73         CAT->getElementType(), llvm::APInt(32, StrBuf.size() + 1),
74         CAT->getSizeModifier(), CAT->getIndexTypeCVRQualifiers());
75     S = StringLiteral::Create(Context, StrBuf, StringLiteral::Ascii,
76                               /*Pascal=*/false, StrTy, &StrLocs[0],
77                               StrLocs.size());
78   }
79 
80   return BuildObjCStringLiteral(AtLocs[0], S);
81 }
82 
BuildObjCStringLiteral(SourceLocation AtLoc,StringLiteral * S)83 ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
84   // Verify that this composite string is acceptable for ObjC strings.
85   if (CheckObjCString(S))
86     return true;
87 
88   // Initialize the constant string interface lazily. This assumes
89   // the NSString interface is seen in this translation unit. Note: We
90   // don't use NSConstantString, since the runtime team considers this
91   // interface private (even though it appears in the header files).
92   QualType Ty = Context.getObjCConstantStringInterface();
93   if (!Ty.isNull()) {
94     Ty = Context.getObjCObjectPointerType(Ty);
95   } else if (getLangOpts().NoConstantCFStrings) {
96     IdentifierInfo *NSIdent=nullptr;
97     std::string StringClass(getLangOpts().ObjCConstantStringClass);
98 
99     if (StringClass.empty())
100       NSIdent = &Context.Idents.get("NSConstantString");
101     else
102       NSIdent = &Context.Idents.get(StringClass);
103 
104     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
105                                      LookupOrdinaryName);
106     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
107       Context.setObjCConstantStringInterface(StrIF);
108       Ty = Context.getObjCConstantStringInterface();
109       Ty = Context.getObjCObjectPointerType(Ty);
110     } else {
111       // If there is no NSConstantString interface defined then treat this
112       // as error and recover from it.
113       Diag(S->getLocStart(), diag::err_no_nsconstant_string_class) << NSIdent
114         << S->getSourceRange();
115       Ty = Context.getObjCIdType();
116     }
117   } else {
118     IdentifierInfo *NSIdent = NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
119     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
120                                      LookupOrdinaryName);
121     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
122       Context.setObjCConstantStringInterface(StrIF);
123       Ty = Context.getObjCConstantStringInterface();
124       Ty = Context.getObjCObjectPointerType(Ty);
125     } else {
126       // If there is no NSString interface defined, implicitly declare
127       // a @class NSString; and use that instead. This is to make sure
128       // type of an NSString literal is represented correctly, instead of
129       // being an 'id' type.
130       Ty = Context.getObjCNSStringType();
131       if (Ty.isNull()) {
132         ObjCInterfaceDecl *NSStringIDecl =
133           ObjCInterfaceDecl::Create (Context,
134                                      Context.getTranslationUnitDecl(),
135                                      SourceLocation(), NSIdent,
136                                      nullptr, SourceLocation());
137         Ty = Context.getObjCInterfaceType(NSStringIDecl);
138         Context.setObjCNSStringType(Ty);
139       }
140       Ty = Context.getObjCObjectPointerType(Ty);
141     }
142   }
143 
144   return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
145 }
146 
147 /// \brief Emits an error if the given method does not exist, or if the return
148 /// type is not an Objective-C object.
validateBoxingMethod(Sema & S,SourceLocation Loc,const ObjCInterfaceDecl * Class,Selector Sel,const ObjCMethodDecl * Method)149 static bool validateBoxingMethod(Sema &S, SourceLocation Loc,
150                                  const ObjCInterfaceDecl *Class,
151                                  Selector Sel, const ObjCMethodDecl *Method) {
152   if (!Method) {
153     // FIXME: Is there a better way to avoid quotes than using getName()?
154     S.Diag(Loc, diag::err_undeclared_boxing_method) << Sel << Class->getName();
155     return false;
156   }
157 
158   // Make sure the return type is reasonable.
159   QualType ReturnType = Method->getReturnType();
160   if (!ReturnType->isObjCObjectPointerType()) {
161     S.Diag(Loc, diag::err_objc_literal_method_sig)
162       << Sel;
163     S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
164       << ReturnType;
165     return false;
166   }
167 
168   return true;
169 }
170 
171 /// \brief Retrieve the NSNumber factory method that should be used to create
172 /// an Objective-C literal for the given type.
getNSNumberFactoryMethod(Sema & S,SourceLocation Loc,QualType NumberType,bool isLiteral=false,SourceRange R=SourceRange ())173 static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
174                                                 QualType NumberType,
175                                                 bool isLiteral = false,
176                                                 SourceRange R = SourceRange()) {
177   Optional<NSAPI::NSNumberLiteralMethodKind> Kind =
178       S.NSAPIObj->getNSNumberFactoryMethodKind(NumberType);
179 
180   if (!Kind) {
181     if (isLiteral) {
182       S.Diag(Loc, diag::err_invalid_nsnumber_type)
183         << NumberType << R;
184     }
185     return nullptr;
186   }
187 
188   // If we already looked up this method, we're done.
189   if (S.NSNumberLiteralMethods[*Kind])
190     return S.NSNumberLiteralMethods[*Kind];
191 
192   Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
193                                                         /*Instance=*/false);
194 
195   ASTContext &CX = S.Context;
196 
197   // Look up the NSNumber class, if we haven't done so already. It's cached
198   // in the Sema instance.
199   if (!S.NSNumberDecl) {
200     IdentifierInfo *NSNumberId =
201       S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSNumber);
202     NamedDecl *IF = S.LookupSingleName(S.TUScope, NSNumberId,
203                                        Loc, Sema::LookupOrdinaryName);
204     S.NSNumberDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
205     if (!S.NSNumberDecl) {
206       if (S.getLangOpts().DebuggerObjCLiteral) {
207         // Create a stub definition of NSNumber.
208         S.NSNumberDecl = ObjCInterfaceDecl::Create(CX,
209                                                    CX.getTranslationUnitDecl(),
210                                                    SourceLocation(), NSNumberId,
211                                                    nullptr, SourceLocation());
212       } else {
213         // Otherwise, require a declaration of NSNumber.
214         S.Diag(Loc, diag::err_undeclared_nsnumber);
215         return nullptr;
216       }
217     } else if (!S.NSNumberDecl->hasDefinition()) {
218       S.Diag(Loc, diag::err_undeclared_nsnumber);
219       return nullptr;
220     }
221 
222     // generate the pointer to NSNumber type.
223     QualType NSNumberObject = CX.getObjCInterfaceType(S.NSNumberDecl);
224     S.NSNumberPointer = CX.getObjCObjectPointerType(NSNumberObject);
225   }
226 
227   // Look for the appropriate method within NSNumber.
228   ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);
229   if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
230     // create a stub definition this NSNumber factory method.
231     TypeSourceInfo *ReturnTInfo = nullptr;
232     Method =
233         ObjCMethodDecl::Create(CX, SourceLocation(), SourceLocation(), Sel,
234                                S.NSNumberPointer, ReturnTInfo, S.NSNumberDecl,
235                                /*isInstance=*/false, /*isVariadic=*/false,
236                                /*isPropertyAccessor=*/false,
237                                /*isImplicitlyDeclared=*/true,
238                                /*isDefined=*/false, ObjCMethodDecl::Required,
239                                /*HasRelatedResultType=*/false);
240     ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
241                                              SourceLocation(), SourceLocation(),
242                                              &CX.Idents.get("value"),
243                                              NumberType, /*TInfo=*/nullptr,
244                                              SC_None, nullptr);
245     Method->setMethodParams(S.Context, value, None);
246   }
247 
248   if (!validateBoxingMethod(S, Loc, S.NSNumberDecl, Sel, Method))
249     return nullptr;
250 
251   // Note: if the parameter type is out-of-line, we'll catch it later in the
252   // implicit conversion.
253 
254   S.NSNumberLiteralMethods[*Kind] = Method;
255   return Method;
256 }
257 
258 /// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
259 /// numeric literal expression. Type of the expression will be "NSNumber *".
BuildObjCNumericLiteral(SourceLocation AtLoc,Expr * Number)260 ExprResult Sema::BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number) {
261   // Determine the type of the literal.
262   QualType NumberType = Number->getType();
263   if (CharacterLiteral *Char = dyn_cast<CharacterLiteral>(Number)) {
264     // In C, character literals have type 'int'. That's not the type we want
265     // to use to determine the Objective-c literal kind.
266     switch (Char->getKind()) {
267     case CharacterLiteral::Ascii:
268       NumberType = Context.CharTy;
269       break;
270 
271     case CharacterLiteral::Wide:
272       NumberType = Context.getWideCharType();
273       break;
274 
275     case CharacterLiteral::UTF16:
276       NumberType = Context.Char16Ty;
277       break;
278 
279     case CharacterLiteral::UTF32:
280       NumberType = Context.Char32Ty;
281       break;
282     }
283   }
284 
285   // Look for the appropriate method within NSNumber.
286   // Construct the literal.
287   SourceRange NR(Number->getSourceRange());
288   ObjCMethodDecl *Method = getNSNumberFactoryMethod(*this, AtLoc, NumberType,
289                                                     true, NR);
290   if (!Method)
291     return ExprError();
292 
293   // Convert the number to the type that the parameter expects.
294   ParmVarDecl *ParamDecl = Method->parameters()[0];
295   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
296                                                                     ParamDecl);
297   ExprResult ConvertedNumber = PerformCopyInitialization(Entity,
298                                                          SourceLocation(),
299                                                          Number);
300   if (ConvertedNumber.isInvalid())
301     return ExprError();
302   Number = ConvertedNumber.get();
303 
304   // Use the effective source range of the literal, including the leading '@'.
305   return MaybeBindToTemporary(
306            new (Context) ObjCBoxedExpr(Number, NSNumberPointer, Method,
307                                        SourceRange(AtLoc, NR.getEnd())));
308 }
309 
ActOnObjCBoolLiteral(SourceLocation AtLoc,SourceLocation ValueLoc,bool Value)310 ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation AtLoc,
311                                       SourceLocation ValueLoc,
312                                       bool Value) {
313   ExprResult Inner;
314   if (getLangOpts().CPlusPlus) {
315     Inner = ActOnCXXBoolLiteral(ValueLoc, Value? tok::kw_true : tok::kw_false);
316   } else {
317     // C doesn't actually have a way to represent literal values of type
318     // _Bool. So, we'll use 0/1 and implicit cast to _Bool.
319     Inner = ActOnIntegerConstant(ValueLoc, Value? 1 : 0);
320     Inner = ImpCastExprToType(Inner.get(), Context.BoolTy,
321                               CK_IntegralToBoolean);
322   }
323 
324   return BuildObjCNumericLiteral(AtLoc, Inner.get());
325 }
326 
327 /// \brief Check that the given expression is a valid element of an Objective-C
328 /// collection literal.
CheckObjCCollectionLiteralElement(Sema & S,Expr * Element,QualType T,bool ArrayLiteral=false)329 static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element,
330                                                     QualType T,
331                                                     bool ArrayLiteral = false) {
332   // If the expression is type-dependent, there's nothing for us to do.
333   if (Element->isTypeDependent())
334     return Element;
335 
336   ExprResult Result = S.CheckPlaceholderExpr(Element);
337   if (Result.isInvalid())
338     return ExprError();
339   Element = Result.get();
340 
341   // In C++, check for an implicit conversion to an Objective-C object pointer
342   // type.
343   if (S.getLangOpts().CPlusPlus && Element->getType()->isRecordType()) {
344     InitializedEntity Entity
345       = InitializedEntity::InitializeParameter(S.Context, T,
346                                                /*Consumed=*/false);
347     InitializationKind Kind
348       = InitializationKind::CreateCopy(Element->getLocStart(),
349                                        SourceLocation());
350     InitializationSequence Seq(S, Entity, Kind, Element);
351     if (!Seq.Failed())
352       return Seq.Perform(S, Entity, Kind, Element);
353   }
354 
355   Expr *OrigElement = Element;
356 
357   // Perform lvalue-to-rvalue conversion.
358   Result = S.DefaultLvalueConversion(Element);
359   if (Result.isInvalid())
360     return ExprError();
361   Element = Result.get();
362 
363   // Make sure that we have an Objective-C pointer type or block.
364   if (!Element->getType()->isObjCObjectPointerType() &&
365       !Element->getType()->isBlockPointerType()) {
366     bool Recovered = false;
367 
368     // If this is potentially an Objective-C numeric literal, add the '@'.
369     if (isa<IntegerLiteral>(OrigElement) ||
370         isa<CharacterLiteral>(OrigElement) ||
371         isa<FloatingLiteral>(OrigElement) ||
372         isa<ObjCBoolLiteralExpr>(OrigElement) ||
373         isa<CXXBoolLiteralExpr>(OrigElement)) {
374       if (S.NSAPIObj->getNSNumberFactoryMethodKind(OrigElement->getType())) {
375         int Which = isa<CharacterLiteral>(OrigElement) ? 1
376                   : (isa<CXXBoolLiteralExpr>(OrigElement) ||
377                      isa<ObjCBoolLiteralExpr>(OrigElement)) ? 2
378                   : 3;
379 
380         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
381           << Which << OrigElement->getSourceRange()
382           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
383 
384         Result = S.BuildObjCNumericLiteral(OrigElement->getLocStart(),
385                                            OrigElement);
386         if (Result.isInvalid())
387           return ExprError();
388 
389         Element = Result.get();
390         Recovered = true;
391       }
392     }
393     // If this is potentially an Objective-C string literal, add the '@'.
394     else if (StringLiteral *String = dyn_cast<StringLiteral>(OrigElement)) {
395       if (String->isAscii()) {
396         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
397           << 0 << OrigElement->getSourceRange()
398           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
399 
400         Result = S.BuildObjCStringLiteral(OrigElement->getLocStart(), String);
401         if (Result.isInvalid())
402           return ExprError();
403 
404         Element = Result.get();
405         Recovered = true;
406       }
407     }
408 
409     if (!Recovered) {
410       S.Diag(Element->getLocStart(), diag::err_invalid_collection_element)
411         << Element->getType();
412       return ExprError();
413     }
414   }
415   if (ArrayLiteral)
416     if (ObjCStringLiteral *getString =
417           dyn_cast<ObjCStringLiteral>(OrigElement)) {
418       if (StringLiteral *SL = getString->getString()) {
419         unsigned numConcat = SL->getNumConcatenated();
420         if (numConcat > 1) {
421           // Only warn if the concatenated string doesn't come from a macro.
422           bool hasMacro = false;
423           for (unsigned i = 0; i < numConcat ; ++i)
424             if (SL->getStrTokenLoc(i).isMacroID()) {
425               hasMacro = true;
426               break;
427             }
428           if (!hasMacro)
429             S.Diag(Element->getLocStart(),
430                    diag::warn_concatenated_nsarray_literal)
431               << Element->getType();
432         }
433       }
434     }
435 
436   // Make sure that the element has the type that the container factory
437   // function expects.
438   return S.PerformCopyInitialization(
439            InitializedEntity::InitializeParameter(S.Context, T,
440                                                   /*Consumed=*/false),
441            Element->getLocStart(), Element);
442 }
443 
BuildObjCBoxedExpr(SourceRange SR,Expr * ValueExpr)444 ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
445   if (ValueExpr->isTypeDependent()) {
446     ObjCBoxedExpr *BoxedExpr =
447       new (Context) ObjCBoxedExpr(ValueExpr, Context.DependentTy, nullptr, SR);
448     return BoxedExpr;
449   }
450   ObjCMethodDecl *BoxingMethod = nullptr;
451   QualType BoxedType;
452   // Convert the expression to an RValue, so we can check for pointer types...
453   ExprResult RValue = DefaultFunctionArrayLvalueConversion(ValueExpr);
454   if (RValue.isInvalid()) {
455     return ExprError();
456   }
457   ValueExpr = RValue.get();
458   QualType ValueType(ValueExpr->getType());
459   if (const PointerType *PT = ValueType->getAs<PointerType>()) {
460     QualType PointeeType = PT->getPointeeType();
461     if (Context.hasSameUnqualifiedType(PointeeType, Context.CharTy)) {
462 
463       if (!NSStringDecl) {
464         IdentifierInfo *NSStringId =
465           NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
466         NamedDecl *Decl = LookupSingleName(TUScope, NSStringId,
467                                            SR.getBegin(), LookupOrdinaryName);
468         NSStringDecl = dyn_cast_or_null<ObjCInterfaceDecl>(Decl);
469         if (!NSStringDecl) {
470           if (getLangOpts().DebuggerObjCLiteral) {
471             // Support boxed expressions in the debugger w/o NSString declaration.
472             DeclContext *TU = Context.getTranslationUnitDecl();
473             NSStringDecl = ObjCInterfaceDecl::Create(Context, TU,
474                                                      SourceLocation(),
475                                                      NSStringId,
476                                                      nullptr, SourceLocation());
477           } else {
478             Diag(SR.getBegin(), diag::err_undeclared_nsstring);
479             return ExprError();
480           }
481         } else if (!NSStringDecl->hasDefinition()) {
482           Diag(SR.getBegin(), diag::err_undeclared_nsstring);
483           return ExprError();
484         }
485         assert(NSStringDecl && "NSStringDecl should not be NULL");
486         QualType NSStringObject = Context.getObjCInterfaceType(NSStringDecl);
487         NSStringPointer = Context.getObjCObjectPointerType(NSStringObject);
488       }
489 
490       if (!StringWithUTF8StringMethod) {
491         IdentifierInfo *II = &Context.Idents.get("stringWithUTF8String");
492         Selector stringWithUTF8String = Context.Selectors.getUnarySelector(II);
493 
494         // Look for the appropriate method within NSString.
495         BoxingMethod = NSStringDecl->lookupClassMethod(stringWithUTF8String);
496         if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
497           // Debugger needs to work even if NSString hasn't been defined.
498           TypeSourceInfo *ReturnTInfo = nullptr;
499           ObjCMethodDecl *M = ObjCMethodDecl::Create(
500               Context, SourceLocation(), SourceLocation(), stringWithUTF8String,
501               NSStringPointer, ReturnTInfo, NSStringDecl,
502               /*isInstance=*/false, /*isVariadic=*/false,
503               /*isPropertyAccessor=*/false,
504               /*isImplicitlyDeclared=*/true,
505               /*isDefined=*/false, ObjCMethodDecl::Required,
506               /*HasRelatedResultType=*/false);
507           QualType ConstCharType = Context.CharTy.withConst();
508           ParmVarDecl *value =
509             ParmVarDecl::Create(Context, M,
510                                 SourceLocation(), SourceLocation(),
511                                 &Context.Idents.get("value"),
512                                 Context.getPointerType(ConstCharType),
513                                 /*TInfo=*/nullptr,
514                                 SC_None, nullptr);
515           M->setMethodParams(Context, value, None);
516           BoxingMethod = M;
517         }
518 
519         if (!validateBoxingMethod(*this, SR.getBegin(), NSStringDecl,
520                                   stringWithUTF8String, BoxingMethod))
521            return ExprError();
522 
523         StringWithUTF8StringMethod = BoxingMethod;
524       }
525 
526       BoxingMethod = StringWithUTF8StringMethod;
527       BoxedType = NSStringPointer;
528     }
529   } else if (ValueType->isBuiltinType()) {
530     // The other types we support are numeric, char and BOOL/bool. We could also
531     // provide limited support for structure types, such as NSRange, NSRect, and
532     // NSSize. See NSValue (NSValueGeometryExtensions) in <Foundation/NSGeometry.h>
533     // for more details.
534 
535     // Check for a top-level character literal.
536     if (const CharacterLiteral *Char =
537         dyn_cast<CharacterLiteral>(ValueExpr->IgnoreParens())) {
538       // In C, character literals have type 'int'. That's not the type we want
539       // to use to determine the Objective-c literal kind.
540       switch (Char->getKind()) {
541       case CharacterLiteral::Ascii:
542         ValueType = Context.CharTy;
543         break;
544 
545       case CharacterLiteral::Wide:
546         ValueType = Context.getWideCharType();
547         break;
548 
549       case CharacterLiteral::UTF16:
550         ValueType = Context.Char16Ty;
551         break;
552 
553       case CharacterLiteral::UTF32:
554         ValueType = Context.Char32Ty;
555         break;
556       }
557     }
558     CheckForIntOverflow(ValueExpr);
559     // FIXME:  Do I need to do anything special with BoolTy expressions?
560 
561     // Look for the appropriate method within NSNumber.
562     BoxingMethod = getNSNumberFactoryMethod(*this, SR.getBegin(), ValueType);
563     BoxedType = NSNumberPointer;
564 
565   } else if (const EnumType *ET = ValueType->getAs<EnumType>()) {
566     if (!ET->getDecl()->isComplete()) {
567       Diag(SR.getBegin(), diag::err_objc_incomplete_boxed_expression_type)
568         << ValueType << ValueExpr->getSourceRange();
569       return ExprError();
570     }
571 
572     BoxingMethod = getNSNumberFactoryMethod(*this, SR.getBegin(),
573                                             ET->getDecl()->getIntegerType());
574     BoxedType = NSNumberPointer;
575   }
576 
577   if (!BoxingMethod) {
578     Diag(SR.getBegin(), diag::err_objc_illegal_boxed_expression_type)
579       << ValueType << ValueExpr->getSourceRange();
580     return ExprError();
581   }
582 
583   // Convert the expression to the type that the parameter requires.
584   ParmVarDecl *ParamDecl = BoxingMethod->parameters()[0];
585   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
586                                                                     ParamDecl);
587   ExprResult ConvertedValueExpr = PerformCopyInitialization(Entity,
588                                                             SourceLocation(),
589                                                             ValueExpr);
590   if (ConvertedValueExpr.isInvalid())
591     return ExprError();
592   ValueExpr = ConvertedValueExpr.get();
593 
594   ObjCBoxedExpr *BoxedExpr =
595     new (Context) ObjCBoxedExpr(ValueExpr, BoxedType,
596                                       BoxingMethod, SR);
597   return MaybeBindToTemporary(BoxedExpr);
598 }
599 
600 /// Build an ObjC subscript pseudo-object expression, given that
601 /// that's supported by the runtime.
BuildObjCSubscriptExpression(SourceLocation RB,Expr * BaseExpr,Expr * IndexExpr,ObjCMethodDecl * getterMethod,ObjCMethodDecl * setterMethod)602 ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
603                                         Expr *IndexExpr,
604                                         ObjCMethodDecl *getterMethod,
605                                         ObjCMethodDecl *setterMethod) {
606   assert(!LangOpts.isSubscriptPointerArithmetic());
607 
608   // We can't get dependent types here; our callers should have
609   // filtered them out.
610   assert((!BaseExpr->isTypeDependent() && !IndexExpr->isTypeDependent()) &&
611          "base or index cannot have dependent type here");
612 
613   // Filter out placeholders in the index.  In theory, overloads could
614   // be preserved here, although that might not actually work correctly.
615   ExprResult Result = CheckPlaceholderExpr(IndexExpr);
616   if (Result.isInvalid())
617     return ExprError();
618   IndexExpr = Result.get();
619 
620   // Perform lvalue-to-rvalue conversion on the base.
621   Result = DefaultLvalueConversion(BaseExpr);
622   if (Result.isInvalid())
623     return ExprError();
624   BaseExpr = Result.get();
625 
626   // Build the pseudo-object expression.
627   return ObjCSubscriptRefExpr::Create(Context, BaseExpr, IndexExpr,
628                                       Context.PseudoObjectTy, getterMethod,
629                                       setterMethod, RB);
630 }
631 
BuildObjCArrayLiteral(SourceRange SR,MultiExprArg Elements)632 ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
633   // Look up the NSArray class, if we haven't done so already.
634   if (!NSArrayDecl) {
635     NamedDecl *IF = LookupSingleName(TUScope,
636                                  NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
637                                  SR.getBegin(),
638                                  LookupOrdinaryName);
639     NSArrayDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
640     if (!NSArrayDecl && getLangOpts().DebuggerObjCLiteral)
641       NSArrayDecl =  ObjCInterfaceDecl::Create (Context,
642                             Context.getTranslationUnitDecl(),
643                             SourceLocation(),
644                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
645                             nullptr, SourceLocation());
646 
647     if (!NSArrayDecl) {
648       Diag(SR.getBegin(), diag::err_undeclared_nsarray);
649       return ExprError();
650     }
651   }
652 
653   // Find the arrayWithObjects:count: method, if we haven't done so already.
654   QualType IdT = Context.getObjCIdType();
655   if (!ArrayWithObjectsMethod) {
656     Selector
657       Sel = NSAPIObj->getNSArraySelector(NSAPI::NSArr_arrayWithObjectsCount);
658     ObjCMethodDecl *Method = NSArrayDecl->lookupClassMethod(Sel);
659     if (!Method && getLangOpts().DebuggerObjCLiteral) {
660       TypeSourceInfo *ReturnTInfo = nullptr;
661       Method = ObjCMethodDecl::Create(
662           Context, SourceLocation(), SourceLocation(), Sel, IdT, ReturnTInfo,
663           Context.getTranslationUnitDecl(), false /*Instance*/,
664           false /*isVariadic*/,
665           /*isPropertyAccessor=*/false,
666           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
667           ObjCMethodDecl::Required, false);
668       SmallVector<ParmVarDecl *, 2> Params;
669       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
670                                                  SourceLocation(),
671                                                  SourceLocation(),
672                                                  &Context.Idents.get("objects"),
673                                                  Context.getPointerType(IdT),
674                                                  /*TInfo=*/nullptr,
675                                                  SC_None, nullptr);
676       Params.push_back(objects);
677       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
678                                              SourceLocation(),
679                                              SourceLocation(),
680                                              &Context.Idents.get("cnt"),
681                                              Context.UnsignedLongTy,
682                                              /*TInfo=*/nullptr, SC_None,
683                                              nullptr);
684       Params.push_back(cnt);
685       Method->setMethodParams(Context, Params, None);
686     }
687 
688     if (!validateBoxingMethod(*this, SR.getBegin(), NSArrayDecl, Sel, Method))
689       return ExprError();
690 
691     // Dig out the type that all elements should be converted to.
692     QualType T = Method->parameters()[0]->getType();
693     const PointerType *PtrT = T->getAs<PointerType>();
694     if (!PtrT ||
695         !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
696       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
697         << Sel;
698       Diag(Method->parameters()[0]->getLocation(),
699            diag::note_objc_literal_method_param)
700         << 0 << T
701         << Context.getPointerType(IdT.withConst());
702       return ExprError();
703     }
704 
705     // Check that the 'count' parameter is integral.
706     if (!Method->parameters()[1]->getType()->isIntegerType()) {
707       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
708         << Sel;
709       Diag(Method->parameters()[1]->getLocation(),
710            diag::note_objc_literal_method_param)
711         << 1
712         << Method->parameters()[1]->getType()
713         << "integral";
714       return ExprError();
715     }
716 
717     // We've found a good +arrayWithObjects:count: method. Save it!
718     ArrayWithObjectsMethod = Method;
719   }
720 
721   QualType ObjectsType = ArrayWithObjectsMethod->parameters()[0]->getType();
722   QualType RequiredType = ObjectsType->castAs<PointerType>()->getPointeeType();
723 
724   // Check that each of the elements provided is valid in a collection literal,
725   // performing conversions as necessary.
726   Expr **ElementsBuffer = Elements.data();
727   for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
728     ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
729                                                              ElementsBuffer[I],
730                                                              RequiredType, true);
731     if (Converted.isInvalid())
732       return ExprError();
733 
734     ElementsBuffer[I] = Converted.get();
735   }
736 
737   QualType Ty
738     = Context.getObjCObjectPointerType(
739                                     Context.getObjCInterfaceType(NSArrayDecl));
740 
741   return MaybeBindToTemporary(
742            ObjCArrayLiteral::Create(Context, Elements, Ty,
743                                     ArrayWithObjectsMethod, SR));
744 }
745 
BuildObjCDictionaryLiteral(SourceRange SR,ObjCDictionaryElement * Elements,unsigned NumElements)746 ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
747                                             ObjCDictionaryElement *Elements,
748                                             unsigned NumElements) {
749   // Look up the NSDictionary class, if we haven't done so already.
750   if (!NSDictionaryDecl) {
751     NamedDecl *IF = LookupSingleName(TUScope,
752                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
753                             SR.getBegin(), LookupOrdinaryName);
754     NSDictionaryDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
755     if (!NSDictionaryDecl && getLangOpts().DebuggerObjCLiteral)
756       NSDictionaryDecl =  ObjCInterfaceDecl::Create (Context,
757                             Context.getTranslationUnitDecl(),
758                             SourceLocation(),
759                             NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
760                             nullptr, SourceLocation());
761 
762     if (!NSDictionaryDecl) {
763       Diag(SR.getBegin(), diag::err_undeclared_nsdictionary);
764       return ExprError();
765     }
766   }
767 
768   // Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
769   // so already.
770   QualType IdT = Context.getObjCIdType();
771   if (!DictionaryWithObjectsMethod) {
772     Selector Sel = NSAPIObj->getNSDictionarySelector(
773                                NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
774     ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
775     if (!Method && getLangOpts().DebuggerObjCLiteral) {
776       Method = ObjCMethodDecl::Create(Context,
777                            SourceLocation(), SourceLocation(), Sel,
778                            IdT,
779                            nullptr /*TypeSourceInfo */,
780                            Context.getTranslationUnitDecl(),
781                            false /*Instance*/, false/*isVariadic*/,
782                            /*isPropertyAccessor=*/false,
783                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
784                            ObjCMethodDecl::Required,
785                            false);
786       SmallVector<ParmVarDecl *, 3> Params;
787       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
788                                                  SourceLocation(),
789                                                  SourceLocation(),
790                                                  &Context.Idents.get("objects"),
791                                                  Context.getPointerType(IdT),
792                                                  /*TInfo=*/nullptr, SC_None,
793                                                  nullptr);
794       Params.push_back(objects);
795       ParmVarDecl *keys = ParmVarDecl::Create(Context, Method,
796                                               SourceLocation(),
797                                               SourceLocation(),
798                                               &Context.Idents.get("keys"),
799                                               Context.getPointerType(IdT),
800                                               /*TInfo=*/nullptr, SC_None,
801                                               nullptr);
802       Params.push_back(keys);
803       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
804                                              SourceLocation(),
805                                              SourceLocation(),
806                                              &Context.Idents.get("cnt"),
807                                              Context.UnsignedLongTy,
808                                              /*TInfo=*/nullptr, SC_None,
809                                              nullptr);
810       Params.push_back(cnt);
811       Method->setMethodParams(Context, Params, None);
812     }
813 
814     if (!validateBoxingMethod(*this, SR.getBegin(), NSDictionaryDecl, Sel,
815                               Method))
816        return ExprError();
817 
818     // Dig out the type that all values should be converted to.
819     QualType ValueT = Method->parameters()[0]->getType();
820     const PointerType *PtrValue = ValueT->getAs<PointerType>();
821     if (!PtrValue ||
822         !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
823       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
824         << Sel;
825       Diag(Method->parameters()[0]->getLocation(),
826            diag::note_objc_literal_method_param)
827         << 0 << ValueT
828         << Context.getPointerType(IdT.withConst());
829       return ExprError();
830     }
831 
832     // Dig out the type that all keys should be converted to.
833     QualType KeyT = Method->parameters()[1]->getType();
834     const PointerType *PtrKey = KeyT->getAs<PointerType>();
835     if (!PtrKey ||
836         !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
837                                         IdT)) {
838       bool err = true;
839       if (PtrKey) {
840         if (QIDNSCopying.isNull()) {
841           // key argument of selector is id<NSCopying>?
842           if (ObjCProtocolDecl *NSCopyingPDecl =
843               LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
844             ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
845             QIDNSCopying =
846               Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
847                                         (ObjCProtocolDecl**) PQ,1);
848             QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
849           }
850         }
851         if (!QIDNSCopying.isNull())
852           err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
853                                                 QIDNSCopying);
854       }
855 
856       if (err) {
857         Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
858           << Sel;
859         Diag(Method->parameters()[1]->getLocation(),
860              diag::note_objc_literal_method_param)
861           << 1 << KeyT
862           << Context.getPointerType(IdT.withConst());
863         return ExprError();
864       }
865     }
866 
867     // Check that the 'count' parameter is integral.
868     QualType CountType = Method->parameters()[2]->getType();
869     if (!CountType->isIntegerType()) {
870       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
871         << Sel;
872       Diag(Method->parameters()[2]->getLocation(),
873            diag::note_objc_literal_method_param)
874         << 2 << CountType
875         << "integral";
876       return ExprError();
877     }
878 
879     // We've found a good +dictionaryWithObjects:keys:count: method; save it!
880     DictionaryWithObjectsMethod = Method;
881   }
882 
883   QualType ValuesT = DictionaryWithObjectsMethod->parameters()[0]->getType();
884   QualType ValueT = ValuesT->castAs<PointerType>()->getPointeeType();
885   QualType KeysT = DictionaryWithObjectsMethod->parameters()[1]->getType();
886   QualType KeyT = KeysT->castAs<PointerType>()->getPointeeType();
887 
888   // Check that each of the keys and values provided is valid in a collection
889   // literal, performing conversions as necessary.
890   bool HasPackExpansions = false;
891   for (unsigned I = 0, N = NumElements; I != N; ++I) {
892     // Check the key.
893     ExprResult Key = CheckObjCCollectionLiteralElement(*this, Elements[I].Key,
894                                                        KeyT);
895     if (Key.isInvalid())
896       return ExprError();
897 
898     // Check the value.
899     ExprResult Value
900       = CheckObjCCollectionLiteralElement(*this, Elements[I].Value, ValueT);
901     if (Value.isInvalid())
902       return ExprError();
903 
904     Elements[I].Key = Key.get();
905     Elements[I].Value = Value.get();
906 
907     if (Elements[I].EllipsisLoc.isInvalid())
908       continue;
909 
910     if (!Elements[I].Key->containsUnexpandedParameterPack() &&
911         !Elements[I].Value->containsUnexpandedParameterPack()) {
912       Diag(Elements[I].EllipsisLoc,
913            diag::err_pack_expansion_without_parameter_packs)
914         << SourceRange(Elements[I].Key->getLocStart(),
915                        Elements[I].Value->getLocEnd());
916       return ExprError();
917     }
918 
919     HasPackExpansions = true;
920   }
921 
922 
923   QualType Ty
924     = Context.getObjCObjectPointerType(
925                                 Context.getObjCInterfaceType(NSDictionaryDecl));
926   return MaybeBindToTemporary(ObjCDictionaryLiteral::Create(
927       Context, makeArrayRef(Elements, NumElements), HasPackExpansions, Ty,
928       DictionaryWithObjectsMethod, SR));
929 }
930 
BuildObjCEncodeExpression(SourceLocation AtLoc,TypeSourceInfo * EncodedTypeInfo,SourceLocation RParenLoc)931 ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
932                                       TypeSourceInfo *EncodedTypeInfo,
933                                       SourceLocation RParenLoc) {
934   QualType EncodedType = EncodedTypeInfo->getType();
935   QualType StrTy;
936   if (EncodedType->isDependentType())
937     StrTy = Context.DependentTy;
938   else {
939     if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
940         !EncodedType->isVoidType()) // void is handled too.
941       if (RequireCompleteType(AtLoc, EncodedType,
942                               diag::err_incomplete_type_objc_at_encode,
943                               EncodedTypeInfo->getTypeLoc()))
944         return ExprError();
945 
946     std::string Str;
947     Context.getObjCEncodingForType(EncodedType, Str);
948 
949     // The type of @encode is the same as the type of the corresponding string,
950     // which is an array type.
951     StrTy = Context.CharTy;
952     // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
953     if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings)
954       StrTy.addConst();
955     StrTy = Context.getConstantArrayType(StrTy, llvm::APInt(32, Str.size()+1),
956                                          ArrayType::Normal, 0);
957   }
958 
959   return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
960 }
961 
ParseObjCEncodeExpression(SourceLocation AtLoc,SourceLocation EncodeLoc,SourceLocation LParenLoc,ParsedType ty,SourceLocation RParenLoc)962 ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
963                                            SourceLocation EncodeLoc,
964                                            SourceLocation LParenLoc,
965                                            ParsedType ty,
966                                            SourceLocation RParenLoc) {
967   // FIXME: Preserve type source info ?
968   TypeSourceInfo *TInfo;
969   QualType EncodedType = GetTypeFromParser(ty, &TInfo);
970   if (!TInfo)
971     TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
972                                              PP.getLocForEndOfToken(LParenLoc));
973 
974   return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
975 }
976 
HelperToDiagnoseMismatchedMethodsInGlobalPool(Sema & S,SourceLocation AtLoc,SourceLocation LParenLoc,SourceLocation RParenLoc,ObjCMethodDecl * Method,ObjCMethodList & MethList)977 static bool HelperToDiagnoseMismatchedMethodsInGlobalPool(Sema &S,
978                                                SourceLocation AtLoc,
979                                                SourceLocation LParenLoc,
980                                                SourceLocation RParenLoc,
981                                                ObjCMethodDecl *Method,
982                                                ObjCMethodList &MethList) {
983   ObjCMethodList *M = &MethList;
984   bool Warned = false;
985   for (M = M->getNext(); M; M=M->getNext()) {
986     ObjCMethodDecl *MatchingMethodDecl = M->Method;
987     if (MatchingMethodDecl == Method ||
988         isa<ObjCImplDecl>(MatchingMethodDecl->getDeclContext()) ||
989         MatchingMethodDecl->getSelector() != Method->getSelector())
990       continue;
991     if (!S.MatchTwoMethodDeclarations(Method,
992                                       MatchingMethodDecl, Sema::MMS_loose)) {
993       if (!Warned) {
994         Warned = true;
995         S.Diag(AtLoc, diag::warning_multiple_selectors)
996           << Method->getSelector() << FixItHint::CreateInsertion(LParenLoc, "(")
997           << FixItHint::CreateInsertion(RParenLoc, ")");
998         S.Diag(Method->getLocation(), diag::note_method_declared_at)
999           << Method->getDeclName();
1000       }
1001       S.Diag(MatchingMethodDecl->getLocation(), diag::note_method_declared_at)
1002         << MatchingMethodDecl->getDeclName();
1003     }
1004   }
1005   return Warned;
1006 }
1007 
DiagnoseMismatchedSelectors(Sema & S,SourceLocation AtLoc,ObjCMethodDecl * Method,SourceLocation LParenLoc,SourceLocation RParenLoc,bool WarnMultipleSelectors)1008 static void DiagnoseMismatchedSelectors(Sema &S, SourceLocation AtLoc,
1009                                         ObjCMethodDecl *Method,
1010                                         SourceLocation LParenLoc,
1011                                         SourceLocation RParenLoc,
1012                                         bool WarnMultipleSelectors) {
1013   if (!WarnMultipleSelectors ||
1014       S.Diags.isIgnored(diag::warning_multiple_selectors, SourceLocation()))
1015     return;
1016   bool Warned = false;
1017   for (Sema::GlobalMethodPool::iterator b = S.MethodPool.begin(),
1018        e = S.MethodPool.end(); b != e; b++) {
1019     // first, instance methods
1020     ObjCMethodList &InstMethList = b->second.first;
1021     if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
1022                                                       Method, InstMethList))
1023       Warned = true;
1024 
1025     // second, class methods
1026     ObjCMethodList &ClsMethList = b->second.second;
1027     if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
1028                                                       Method, ClsMethList) || Warned)
1029       return;
1030   }
1031 }
1032 
ParseObjCSelectorExpression(Selector Sel,SourceLocation AtLoc,SourceLocation SelLoc,SourceLocation LParenLoc,SourceLocation RParenLoc,bool WarnMultipleSelectors)1033 ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
1034                                              SourceLocation AtLoc,
1035                                              SourceLocation SelLoc,
1036                                              SourceLocation LParenLoc,
1037                                              SourceLocation RParenLoc,
1038                                              bool WarnMultipleSelectors) {
1039   ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
1040                              SourceRange(LParenLoc, RParenLoc), false, false);
1041   if (!Method)
1042     Method = LookupFactoryMethodInGlobalPool(Sel,
1043                                           SourceRange(LParenLoc, RParenLoc));
1044   if (!Method) {
1045     if (const ObjCMethodDecl *OM = SelectorsForTypoCorrection(Sel)) {
1046       Selector MatchedSel = OM->getSelector();
1047       SourceRange SelectorRange(LParenLoc.getLocWithOffset(1),
1048                                 RParenLoc.getLocWithOffset(-1));
1049       Diag(SelLoc, diag::warn_undeclared_selector_with_typo)
1050         << Sel << MatchedSel
1051         << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
1052 
1053     } else
1054         Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
1055   } else
1056     DiagnoseMismatchedSelectors(*this, AtLoc, Method, LParenLoc, RParenLoc,
1057                                 WarnMultipleSelectors);
1058 
1059   if (Method &&
1060       Method->getImplementationControl() != ObjCMethodDecl::Optional &&
1061       !getSourceManager().isInSystemHeader(Method->getLocation())) {
1062     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
1063       = ReferencedSelectors.find(Sel);
1064     if (Pos == ReferencedSelectors.end())
1065       ReferencedSelectors.insert(std::make_pair(Sel, AtLoc));
1066   }
1067 
1068   // In ARC, forbid the user from using @selector for
1069   // retain/release/autorelease/dealloc/retainCount.
1070   if (getLangOpts().ObjCAutoRefCount) {
1071     switch (Sel.getMethodFamily()) {
1072     case OMF_retain:
1073     case OMF_release:
1074     case OMF_autorelease:
1075     case OMF_retainCount:
1076     case OMF_dealloc:
1077       Diag(AtLoc, diag::err_arc_illegal_selector) <<
1078         Sel << SourceRange(LParenLoc, RParenLoc);
1079       break;
1080 
1081     case OMF_None:
1082     case OMF_alloc:
1083     case OMF_copy:
1084     case OMF_finalize:
1085     case OMF_init:
1086     case OMF_mutableCopy:
1087     case OMF_new:
1088     case OMF_self:
1089     case OMF_performSelector:
1090       break;
1091     }
1092   }
1093   QualType Ty = Context.getObjCSelType();
1094   return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
1095 }
1096 
ParseObjCProtocolExpression(IdentifierInfo * ProtocolId,SourceLocation AtLoc,SourceLocation ProtoLoc,SourceLocation LParenLoc,SourceLocation ProtoIdLoc,SourceLocation RParenLoc)1097 ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
1098                                              SourceLocation AtLoc,
1099                                              SourceLocation ProtoLoc,
1100                                              SourceLocation LParenLoc,
1101                                              SourceLocation ProtoIdLoc,
1102                                              SourceLocation RParenLoc) {
1103   ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoIdLoc);
1104   if (!PDecl) {
1105     Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
1106     return true;
1107   }
1108 
1109   QualType Ty = Context.getObjCProtoType();
1110   if (Ty.isNull())
1111     return true;
1112   Ty = Context.getObjCObjectPointerType(Ty);
1113   return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, ProtoIdLoc, RParenLoc);
1114 }
1115 
1116 /// Try to capture an implicit reference to 'self'.
tryCaptureObjCSelf(SourceLocation Loc)1117 ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
1118   DeclContext *DC = getFunctionLevelDeclContext();
1119 
1120   // If we're not in an ObjC method, error out.  Note that, unlike the
1121   // C++ case, we don't require an instance method --- class methods
1122   // still have a 'self', and we really do still need to capture it!
1123   ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
1124   if (!method)
1125     return nullptr;
1126 
1127   tryCaptureVariable(method->getSelfDecl(), Loc);
1128 
1129   return method;
1130 }
1131 
stripObjCInstanceType(ASTContext & Context,QualType T)1132 static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
1133   if (T == Context.getObjCInstanceType())
1134     return Context.getObjCIdType();
1135 
1136   return T;
1137 }
1138 
getMessageSendResultType(QualType ReceiverType,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage)1139 QualType Sema::getMessageSendResultType(QualType ReceiverType,
1140                                         ObjCMethodDecl *Method,
1141                                     bool isClassMessage, bool isSuperMessage) {
1142   assert(Method && "Must have a method");
1143   if (!Method->hasRelatedResultType())
1144     return Method->getSendResultType();
1145 
1146   // If a method has a related return type:
1147   //   - if the method found is an instance method, but the message send
1148   //     was a class message send, T is the declared return type of the method
1149   //     found
1150   if (Method->isInstanceMethod() && isClassMessage)
1151     return stripObjCInstanceType(Context, Method->getSendResultType());
1152 
1153   //   - if the receiver is super, T is a pointer to the class of the
1154   //     enclosing method definition
1155   if (isSuperMessage) {
1156     if (ObjCMethodDecl *CurMethod = getCurMethodDecl())
1157       if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface())
1158         return Context.getObjCObjectPointerType(
1159                                         Context.getObjCInterfaceType(Class));
1160   }
1161 
1162   //   - if the receiver is the name of a class U, T is a pointer to U
1163   if (ReceiverType->getAs<ObjCInterfaceType>() ||
1164       ReceiverType->isObjCQualifiedInterfaceType())
1165     return Context.getObjCObjectPointerType(ReceiverType);
1166   //   - if the receiver is of type Class or qualified Class type,
1167   //     T is the declared return type of the method.
1168   if (ReceiverType->isObjCClassType() ||
1169       ReceiverType->isObjCQualifiedClassType())
1170     return stripObjCInstanceType(Context, Method->getSendResultType());
1171 
1172   //   - if the receiver is id, qualified id, Class, or qualified Class, T
1173   //     is the receiver type, otherwise
1174   //   - T is the type of the receiver expression.
1175   return ReceiverType;
1176 }
1177 
1178 /// Look for an ObjC method whose result type exactly matches the given type.
1179 static const ObjCMethodDecl *
findExplicitInstancetypeDeclarer(const ObjCMethodDecl * MD,QualType instancetype)1180 findExplicitInstancetypeDeclarer(const ObjCMethodDecl *MD,
1181                                  QualType instancetype) {
1182   if (MD->getReturnType() == instancetype)
1183     return MD;
1184 
1185   // For these purposes, a method in an @implementation overrides a
1186   // declaration in the @interface.
1187   if (const ObjCImplDecl *impl =
1188         dyn_cast<ObjCImplDecl>(MD->getDeclContext())) {
1189     const ObjCContainerDecl *iface;
1190     if (const ObjCCategoryImplDecl *catImpl =
1191           dyn_cast<ObjCCategoryImplDecl>(impl)) {
1192       iface = catImpl->getCategoryDecl();
1193     } else {
1194       iface = impl->getClassInterface();
1195     }
1196 
1197     const ObjCMethodDecl *ifaceMD =
1198       iface->getMethod(MD->getSelector(), MD->isInstanceMethod());
1199     if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype);
1200   }
1201 
1202   SmallVector<const ObjCMethodDecl *, 4> overrides;
1203   MD->getOverriddenMethods(overrides);
1204   for (unsigned i = 0, e = overrides.size(); i != e; ++i) {
1205     if (const ObjCMethodDecl *result =
1206           findExplicitInstancetypeDeclarer(overrides[i], instancetype))
1207       return result;
1208   }
1209 
1210   return nullptr;
1211 }
1212 
EmitRelatedResultTypeNoteForReturn(QualType destType)1213 void Sema::EmitRelatedResultTypeNoteForReturn(QualType destType) {
1214   // Only complain if we're in an ObjC method and the required return
1215   // type doesn't match the method's declared return type.
1216   ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurContext);
1217   if (!MD || !MD->hasRelatedResultType() ||
1218       Context.hasSameUnqualifiedType(destType, MD->getReturnType()))
1219     return;
1220 
1221   // Look for a method overridden by this method which explicitly uses
1222   // 'instancetype'.
1223   if (const ObjCMethodDecl *overridden =
1224         findExplicitInstancetypeDeclarer(MD, Context.getObjCInstanceType())) {
1225     SourceLocation loc;
1226     SourceRange range;
1227     if (TypeSourceInfo *TSI = overridden->getReturnTypeSourceInfo()) {
1228       range = TSI->getTypeLoc().getSourceRange();
1229       loc = range.getBegin();
1230     }
1231     if (loc.isInvalid())
1232       loc = overridden->getLocation();
1233     Diag(loc, diag::note_related_result_type_explicit)
1234       << /*current method*/ 1 << range;
1235     return;
1236   }
1237 
1238   // Otherwise, if we have an interesting method family, note that.
1239   // This should always trigger if the above didn't.
1240   if (ObjCMethodFamily family = MD->getMethodFamily())
1241     Diag(MD->getLocation(), diag::note_related_result_type_family)
1242       << /*current method*/ 1
1243       << family;
1244 }
1245 
EmitRelatedResultTypeNote(const Expr * E)1246 void Sema::EmitRelatedResultTypeNote(const Expr *E) {
1247   E = E->IgnoreParenImpCasts();
1248   const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
1249   if (!MsgSend)
1250     return;
1251 
1252   const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
1253   if (!Method)
1254     return;
1255 
1256   if (!Method->hasRelatedResultType())
1257     return;
1258 
1259   if (Context.hasSameUnqualifiedType(
1260           Method->getReturnType().getNonReferenceType(), MsgSend->getType()))
1261     return;
1262 
1263   if (!Context.hasSameUnqualifiedType(Method->getReturnType(),
1264                                       Context.getObjCInstanceType()))
1265     return;
1266 
1267   Diag(Method->getLocation(), diag::note_related_result_type_inferred)
1268     << Method->isInstanceMethod() << Method->getSelector()
1269     << MsgSend->getType();
1270 }
1271 
CheckMessageArgumentTypes(QualType ReceiverType,MultiExprArg Args,Selector Sel,ArrayRef<SourceLocation> SelectorLocs,ObjCMethodDecl * Method,bool isClassMessage,bool isSuperMessage,SourceLocation lbrac,SourceLocation rbrac,QualType & ReturnType,ExprValueKind & VK)1272 bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
1273                                      MultiExprArg Args,
1274                                      Selector Sel,
1275                                      ArrayRef<SourceLocation> SelectorLocs,
1276                                      ObjCMethodDecl *Method,
1277                                      bool isClassMessage, bool isSuperMessage,
1278                                      SourceLocation lbrac, SourceLocation rbrac,
1279                                      QualType &ReturnType, ExprValueKind &VK) {
1280   SourceLocation SelLoc;
1281   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
1282     SelLoc = SelectorLocs.front();
1283   else
1284     SelLoc = lbrac;
1285 
1286   if (!Method) {
1287     // Apply default argument promotion as for (C99 6.5.2.2p6).
1288     for (unsigned i = 0, e = Args.size(); i != e; i++) {
1289       if (Args[i]->isTypeDependent())
1290         continue;
1291 
1292       ExprResult result;
1293       if (getLangOpts().DebuggerSupport) {
1294         QualType paramTy; // ignored
1295         result = checkUnknownAnyArg(SelLoc, Args[i], paramTy);
1296       } else {
1297         result = DefaultArgumentPromotion(Args[i]);
1298       }
1299       if (result.isInvalid())
1300         return true;
1301       Args[i] = result.get();
1302     }
1303 
1304     unsigned DiagID;
1305     if (getLangOpts().ObjCAutoRefCount)
1306       DiagID = diag::err_arc_method_not_found;
1307     else
1308       DiagID = isClassMessage ? diag::warn_class_method_not_found
1309                               : diag::warn_inst_method_not_found;
1310     if (!getLangOpts().DebuggerSupport) {
1311       const ObjCMethodDecl *OMD = SelectorsForTypoCorrection(Sel, ReceiverType);
1312       if (OMD && !OMD->isInvalidDecl()) {
1313         if (getLangOpts().ObjCAutoRefCount)
1314           DiagID = diag::error_method_not_found_with_typo;
1315         else
1316           DiagID = isClassMessage ? diag::warn_class_method_not_found_with_typo
1317                                   : diag::warn_instance_method_not_found_with_typo;
1318         Selector MatchedSel = OMD->getSelector();
1319         SourceRange SelectorRange(SelectorLocs.front(), SelectorLocs.back());
1320         Diag(SelLoc, DiagID)
1321           << Sel<< isClassMessage << MatchedSel
1322           << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
1323       }
1324       else
1325         Diag(SelLoc, DiagID)
1326           << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
1327                                                 SelectorLocs.back());
1328       // Find the class to which we are sending this message.
1329       if (ReceiverType->isObjCObjectPointerType()) {
1330         if (ObjCInterfaceDecl *Class =
1331               ReceiverType->getAs<ObjCObjectPointerType>()->getInterfaceDecl())
1332           Diag(Class->getLocation(), diag::note_receiver_class_declared);
1333       }
1334     }
1335 
1336     // In debuggers, we want to use __unknown_anytype for these
1337     // results so that clients can cast them.
1338     if (getLangOpts().DebuggerSupport) {
1339       ReturnType = Context.UnknownAnyTy;
1340     } else {
1341       ReturnType = Context.getObjCIdType();
1342     }
1343     VK = VK_RValue;
1344     return false;
1345   }
1346 
1347   ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage,
1348                                         isSuperMessage);
1349   VK = Expr::getValueKindForType(Method->getReturnType());
1350 
1351   unsigned NumNamedArgs = Sel.getNumArgs();
1352   // Method might have more arguments than selector indicates. This is due
1353   // to addition of c-style arguments in method.
1354   if (Method->param_size() > Sel.getNumArgs())
1355     NumNamedArgs = Method->param_size();
1356   // FIXME. This need be cleaned up.
1357   if (Args.size() < NumNamedArgs) {
1358     Diag(SelLoc, diag::err_typecheck_call_too_few_args)
1359       << 2 << NumNamedArgs << static_cast<unsigned>(Args.size());
1360     return false;
1361   }
1362 
1363   bool IsError = false;
1364   for (unsigned i = 0; i < NumNamedArgs; i++) {
1365     // We can't do any type-checking on a type-dependent argument.
1366     if (Args[i]->isTypeDependent())
1367       continue;
1368 
1369     Expr *argExpr = Args[i];
1370 
1371     ParmVarDecl *param = Method->parameters()[i];
1372     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
1373 
1374     // Strip the unbridged-cast placeholder expression off unless it's
1375     // a consumed argument.
1376     if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
1377         !param->hasAttr<CFConsumedAttr>())
1378       argExpr = stripARCUnbridgedCast(argExpr);
1379 
1380     // If the parameter is __unknown_anytype, infer its type
1381     // from the argument.
1382     if (param->getType() == Context.UnknownAnyTy) {
1383       QualType paramType;
1384       ExprResult argE = checkUnknownAnyArg(SelLoc, argExpr, paramType);
1385       if (argE.isInvalid()) {
1386         IsError = true;
1387       } else {
1388         Args[i] = argE.get();
1389 
1390         // Update the parameter type in-place.
1391         param->setType(paramType);
1392       }
1393       continue;
1394     }
1395 
1396     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
1397                             param->getType(),
1398                             diag::err_call_incomplete_argument, argExpr))
1399       return true;
1400 
1401     InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
1402                                                                       param);
1403     ExprResult ArgE = PerformCopyInitialization(Entity, SelLoc, argExpr);
1404     if (ArgE.isInvalid())
1405       IsError = true;
1406     else
1407       Args[i] = ArgE.getAs<Expr>();
1408   }
1409 
1410   // Promote additional arguments to variadic methods.
1411   if (Method->isVariadic()) {
1412     for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
1413       if (Args[i]->isTypeDependent())
1414         continue;
1415 
1416       ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
1417                                                         nullptr);
1418       IsError |= Arg.isInvalid();
1419       Args[i] = Arg.get();
1420     }
1421   } else {
1422     // Check for extra arguments to non-variadic methods.
1423     if (Args.size() != NumNamedArgs) {
1424       Diag(Args[NumNamedArgs]->getLocStart(),
1425            diag::err_typecheck_call_too_many_args)
1426         << 2 /*method*/ << NumNamedArgs << static_cast<unsigned>(Args.size())
1427         << Method->getSourceRange()
1428         << SourceRange(Args[NumNamedArgs]->getLocStart(),
1429                        Args.back()->getLocEnd());
1430     }
1431   }
1432 
1433   DiagnoseSentinelCalls(Method, SelLoc, Args);
1434 
1435   // Do additional checkings on method.
1436   IsError |= CheckObjCMethodCall(
1437       Method, SelLoc, makeArrayRef<const Expr *>(Args.data(), Args.size()));
1438 
1439   return IsError;
1440 }
1441 
isSelfExpr(Expr * RExpr)1442 bool Sema::isSelfExpr(Expr *RExpr) {
1443   // 'self' is objc 'self' in an objc method only.
1444   ObjCMethodDecl *Method =
1445       dyn_cast_or_null<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
1446   return isSelfExpr(RExpr, Method);
1447 }
1448 
isSelfExpr(Expr * receiver,const ObjCMethodDecl * method)1449 bool Sema::isSelfExpr(Expr *receiver, const ObjCMethodDecl *method) {
1450   if (!method) return false;
1451 
1452   receiver = receiver->IgnoreParenLValueCasts();
1453   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
1454     if (DRE->getDecl() == method->getSelfDecl())
1455       return true;
1456   return false;
1457 }
1458 
1459 /// LookupMethodInType - Look up a method in an ObjCObjectType.
LookupMethodInObjectType(Selector sel,QualType type,bool isInstance)1460 ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
1461                                                bool isInstance) {
1462   const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
1463   if (ObjCInterfaceDecl *iface = objType->getInterface()) {
1464     // Look it up in the main interface (and categories, etc.)
1465     if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
1466       return method;
1467 
1468     // Okay, look for "private" methods declared in any
1469     // @implementations we've seen.
1470     if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
1471       return method;
1472   }
1473 
1474   // Check qualifiers.
1475   for (const auto *I : objType->quals())
1476     if (ObjCMethodDecl *method = I->lookupMethod(sel, isInstance))
1477       return method;
1478 
1479   return nullptr;
1480 }
1481 
1482 /// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1483 /// list of a qualified objective pointer type.
LookupMethodInQualifiedType(Selector Sel,const ObjCObjectPointerType * OPT,bool Instance)1484 ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
1485                                               const ObjCObjectPointerType *OPT,
1486                                               bool Instance)
1487 {
1488   ObjCMethodDecl *MD = nullptr;
1489   for (const auto *PROTO : OPT->quals()) {
1490     if ((MD = PROTO->lookupMethod(Sel, Instance))) {
1491       return MD;
1492     }
1493   }
1494   return nullptr;
1495 }
1496 
DiagnoseARCUseOfWeakReceiver(Sema & S,Expr * Receiver)1497 static void DiagnoseARCUseOfWeakReceiver(Sema &S, Expr *Receiver) {
1498   if (!Receiver)
1499     return;
1500 
1501   if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Receiver))
1502     Receiver = OVE->getSourceExpr();
1503 
1504   Expr *RExpr = Receiver->IgnoreParenImpCasts();
1505   SourceLocation Loc = RExpr->getLocStart();
1506   QualType T = RExpr->getType();
1507   const ObjCPropertyDecl *PDecl = nullptr;
1508   const ObjCMethodDecl *GDecl = nullptr;
1509   if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(RExpr)) {
1510     RExpr = POE->getSyntacticForm();
1511     if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(RExpr)) {
1512       if (PRE->isImplicitProperty()) {
1513         GDecl = PRE->getImplicitPropertyGetter();
1514         if (GDecl) {
1515           T = GDecl->getReturnType();
1516         }
1517       }
1518       else {
1519         PDecl = PRE->getExplicitProperty();
1520         if (PDecl) {
1521           T = PDecl->getType();
1522         }
1523       }
1524     }
1525   }
1526   else if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(RExpr)) {
1527     // See if receiver is a method which envokes a synthesized getter
1528     // backing a 'weak' property.
1529     ObjCMethodDecl *Method = ME->getMethodDecl();
1530     if (Method && Method->getSelector().getNumArgs() == 0) {
1531       PDecl = Method->findPropertyDecl();
1532       if (PDecl)
1533         T = PDecl->getType();
1534     }
1535   }
1536 
1537   if (T.getObjCLifetime() != Qualifiers::OCL_Weak) {
1538     if (!PDecl)
1539       return;
1540     if (!(PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak))
1541       return;
1542   }
1543 
1544   S.Diag(Loc, diag::warn_receiver_is_weak)
1545     << ((!PDecl && !GDecl) ? 0 : (PDecl ? 1 : 2));
1546 
1547   if (PDecl)
1548     S.Diag(PDecl->getLocation(), diag::note_property_declare);
1549   else if (GDecl)
1550     S.Diag(GDecl->getLocation(), diag::note_method_declared_at) << GDecl;
1551 
1552   S.Diag(Loc, diag::note_arc_assign_to_strong);
1553 }
1554 
1555 /// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1556 /// objective C interface.  This is a property reference expression.
1557 ExprResult Sema::
HandleExprPropertyRefExpr(const ObjCObjectPointerType * OPT,Expr * BaseExpr,SourceLocation OpLoc,DeclarationName MemberName,SourceLocation MemberLoc,SourceLocation SuperLoc,QualType SuperType,bool Super)1558 HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
1559                           Expr *BaseExpr, SourceLocation OpLoc,
1560                           DeclarationName MemberName,
1561                           SourceLocation MemberLoc,
1562                           SourceLocation SuperLoc, QualType SuperType,
1563                           bool Super) {
1564   const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
1565   ObjCInterfaceDecl *IFace = IFaceT->getDecl();
1566 
1567   if (!MemberName.isIdentifier()) {
1568     Diag(MemberLoc, diag::err_invalid_property_name)
1569       << MemberName << QualType(OPT, 0);
1570     return ExprError();
1571   }
1572 
1573   IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1574 
1575   SourceRange BaseRange = Super? SourceRange(SuperLoc)
1576                                : BaseExpr->getSourceRange();
1577   if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
1578                           diag::err_property_not_found_forward_class,
1579                           MemberName, BaseRange))
1580     return ExprError();
1581 
1582   // Search for a declared property first.
1583   if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
1584     // Check whether we can reference this property.
1585     if (DiagnoseUseOfDecl(PD, MemberLoc))
1586       return ExprError();
1587     if (Super)
1588       return new (Context)
1589           ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1590                               OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
1591     else
1592       return new (Context)
1593           ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1594                               OK_ObjCProperty, MemberLoc, BaseExpr);
1595   }
1596   // Check protocols on qualified interfaces.
1597   for (const auto *I : OPT->quals())
1598     if (ObjCPropertyDecl *PD = I->FindPropertyDeclaration(Member)) {
1599       // Check whether we can reference this property.
1600       if (DiagnoseUseOfDecl(PD, MemberLoc))
1601         return ExprError();
1602 
1603       if (Super)
1604         return new (Context) ObjCPropertyRefExpr(
1605             PD, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc,
1606             SuperLoc, SuperType);
1607       else
1608         return new (Context)
1609             ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1610                                 OK_ObjCProperty, MemberLoc, BaseExpr);
1611     }
1612   // If that failed, look for an "implicit" property by seeing if the nullary
1613   // selector is implemented.
1614 
1615   // FIXME: The logic for looking up nullary and unary selectors should be
1616   // shared with the code in ActOnInstanceMessage.
1617 
1618   Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
1619   ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
1620 
1621   // May be founf in property's qualified list.
1622   if (!Getter)
1623     Getter = LookupMethodInQualifiedType(Sel, OPT, true);
1624 
1625   // If this reference is in an @implementation, check for 'private' methods.
1626   if (!Getter)
1627     Getter = IFace->lookupPrivateMethod(Sel);
1628 
1629   if (Getter) {
1630     // Check if we can reference this property.
1631     if (DiagnoseUseOfDecl(Getter, MemberLoc))
1632       return ExprError();
1633   }
1634   // If we found a getter then this may be a valid dot-reference, we
1635   // will look for the matching setter, in case it is needed.
1636   Selector SetterSel =
1637     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1638                                            PP.getSelectorTable(), Member);
1639   ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
1640 
1641   // May be founf in property's qualified list.
1642   if (!Setter)
1643     Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
1644 
1645   if (!Setter) {
1646     // If this reference is in an @implementation, also check for 'private'
1647     // methods.
1648     Setter = IFace->lookupPrivateMethod(SetterSel);
1649   }
1650 
1651   if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
1652     return ExprError();
1653 
1654   if (Getter || Setter) {
1655     if (Super)
1656       return new (Context)
1657           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
1658                               OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
1659     else
1660       return new (Context)
1661           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
1662                               OK_ObjCProperty, MemberLoc, BaseExpr);
1663 
1664   }
1665 
1666   // Attempt to correct for typos in property names.
1667   DeclFilterCCC<ObjCPropertyDecl> Validator;
1668   if (TypoCorrection Corrected = CorrectTypo(
1669           DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName,
1670           nullptr, nullptr, Validator, CTK_ErrorRecovery, IFace, false, OPT)) {
1671     diagnoseTypo(Corrected, PDiag(diag::err_property_not_found_suggest)
1672                               << MemberName << QualType(OPT, 0));
1673     DeclarationName TypoResult = Corrected.getCorrection();
1674     return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
1675                                      TypoResult, MemberLoc,
1676                                      SuperLoc, SuperType, Super);
1677   }
1678   ObjCInterfaceDecl *ClassDeclared;
1679   if (ObjCIvarDecl *Ivar =
1680       IFace->lookupInstanceVariable(Member, ClassDeclared)) {
1681     QualType T = Ivar->getType();
1682     if (const ObjCObjectPointerType * OBJPT =
1683         T->getAsObjCInterfacePointerType()) {
1684       if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
1685                               diag::err_property_not_as_forward_class,
1686                               MemberName, BaseExpr))
1687         return ExprError();
1688     }
1689     Diag(MemberLoc,
1690          diag::err_ivar_access_using_property_syntax_suggest)
1691     << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
1692     << FixItHint::CreateReplacement(OpLoc, "->");
1693     return ExprError();
1694   }
1695 
1696   Diag(MemberLoc, diag::err_property_not_found)
1697     << MemberName << QualType(OPT, 0);
1698   if (Setter)
1699     Diag(Setter->getLocation(), diag::note_getter_unavailable)
1700           << MemberName << BaseExpr->getSourceRange();
1701   return ExprError();
1702 }
1703 
1704 
1705 
1706 ExprResult Sema::
ActOnClassPropertyRefExpr(IdentifierInfo & receiverName,IdentifierInfo & propertyName,SourceLocation receiverNameLoc,SourceLocation propertyNameLoc)1707 ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
1708                           IdentifierInfo &propertyName,
1709                           SourceLocation receiverNameLoc,
1710                           SourceLocation propertyNameLoc) {
1711 
1712   IdentifierInfo *receiverNamePtr = &receiverName;
1713   ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
1714                                                   receiverNameLoc);
1715 
1716   bool IsSuper = false;
1717   if (!IFace) {
1718     // If the "receiver" is 'super' in a method, handle it as an expression-like
1719     // property reference.
1720     if (receiverNamePtr->isStr("super")) {
1721       IsSuper = true;
1722 
1723       if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
1724         if (CurMethod->isInstanceMethod()) {
1725           ObjCInterfaceDecl *Super =
1726             CurMethod->getClassInterface()->getSuperClass();
1727           if (!Super) {
1728             // The current class does not have a superclass.
1729             Diag(receiverNameLoc, diag::error_root_class_cannot_use_super)
1730             << CurMethod->getClassInterface()->getIdentifier();
1731             return ExprError();
1732           }
1733           QualType T = Context.getObjCInterfaceType(Super);
1734           T = Context.getObjCObjectPointerType(T);
1735 
1736           return HandleExprPropertyRefExpr(T->getAsObjCInterfacePointerType(),
1737                                            /*BaseExpr*/nullptr,
1738                                            SourceLocation()/*OpLoc*/,
1739                                            &propertyName,
1740                                            propertyNameLoc,
1741                                            receiverNameLoc, T, true);
1742         }
1743 
1744         // Otherwise, if this is a class method, try dispatching to our
1745         // superclass.
1746         IFace = CurMethod->getClassInterface()->getSuperClass();
1747       }
1748     }
1749 
1750     if (!IFace) {
1751       Diag(receiverNameLoc, diag::err_expected_either) << tok::identifier
1752                                                        << tok::l_paren;
1753       return ExprError();
1754     }
1755   }
1756 
1757   // Search for a declared property first.
1758   Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
1759   ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
1760 
1761   // If this reference is in an @implementation, check for 'private' methods.
1762   if (!Getter)
1763     Getter = IFace->lookupPrivateClassMethod(Sel);
1764 
1765   if (Getter) {
1766     // FIXME: refactor/share with ActOnMemberReference().
1767     // Check if we can reference this property.
1768     if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
1769       return ExprError();
1770   }
1771 
1772   // Look for the matching setter, in case it is needed.
1773   Selector SetterSel =
1774     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1775                                            PP.getSelectorTable(),
1776                                            &propertyName);
1777 
1778   ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1779   if (!Setter) {
1780     // If this reference is in an @implementation, also check for 'private'
1781     // methods.
1782     Setter = IFace->lookupPrivateClassMethod(SetterSel);
1783   }
1784   // Look through local category implementations associated with the class.
1785   if (!Setter)
1786     Setter = IFace->getCategoryClassMethod(SetterSel);
1787 
1788   if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
1789     return ExprError();
1790 
1791   if (Getter || Setter) {
1792     if (IsSuper)
1793       return new (Context)
1794           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
1795                               OK_ObjCProperty, propertyNameLoc, receiverNameLoc,
1796                               Context.getObjCInterfaceType(IFace));
1797 
1798     return new (Context) ObjCPropertyRefExpr(
1799         Getter, Setter, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty,
1800         propertyNameLoc, receiverNameLoc, IFace);
1801   }
1802   return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
1803                      << &propertyName << Context.getObjCInterfaceType(IFace));
1804 }
1805 
1806 namespace {
1807 
1808 class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
1809  public:
ObjCInterfaceOrSuperCCC(ObjCMethodDecl * Method)1810   ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
1811     // Determine whether "super" is acceptable in the current context.
1812     if (Method && Method->getClassInterface())
1813       WantObjCSuper = Method->getClassInterface()->getSuperClass();
1814   }
1815 
ValidateCandidate(const TypoCorrection & candidate)1816   bool ValidateCandidate(const TypoCorrection &candidate) override {
1817     return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
1818         candidate.isKeyword("super");
1819   }
1820 };
1821 
1822 }
1823 
getObjCMessageKind(Scope * S,IdentifierInfo * Name,SourceLocation NameLoc,bool IsSuper,bool HasTrailingDot,ParsedType & ReceiverType)1824 Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
1825                                                IdentifierInfo *Name,
1826                                                SourceLocation NameLoc,
1827                                                bool IsSuper,
1828                                                bool HasTrailingDot,
1829                                                ParsedType &ReceiverType) {
1830   ReceiverType = ParsedType();
1831 
1832   // If the identifier is "super" and there is no trailing dot, we're
1833   // messaging super. If the identifier is "super" and there is a
1834   // trailing dot, it's an instance message.
1835   if (IsSuper && S->isInObjcMethodScope())
1836     return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
1837 
1838   LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1839   LookupName(Result, S);
1840 
1841   switch (Result.getResultKind()) {
1842   case LookupResult::NotFound:
1843     // Normal name lookup didn't find anything. If we're in an
1844     // Objective-C method, look for ivars. If we find one, we're done!
1845     // FIXME: This is a hack. Ivar lookup should be part of normal
1846     // lookup.
1847     if (ObjCMethodDecl *Method = getCurMethodDecl()) {
1848       if (!Method->getClassInterface()) {
1849         // Fall back: let the parser try to parse it as an instance message.
1850         return ObjCInstanceMessage;
1851       }
1852 
1853       ObjCInterfaceDecl *ClassDeclared;
1854       if (Method->getClassInterface()->lookupInstanceVariable(Name,
1855                                                               ClassDeclared))
1856         return ObjCInstanceMessage;
1857     }
1858 
1859     // Break out; we'll perform typo correction below.
1860     break;
1861 
1862   case LookupResult::NotFoundInCurrentInstantiation:
1863   case LookupResult::FoundOverloaded:
1864   case LookupResult::FoundUnresolvedValue:
1865   case LookupResult::Ambiguous:
1866     Result.suppressDiagnostics();
1867     return ObjCInstanceMessage;
1868 
1869   case LookupResult::Found: {
1870     // If the identifier is a class or not, and there is a trailing dot,
1871     // it's an instance message.
1872     if (HasTrailingDot)
1873       return ObjCInstanceMessage;
1874     // We found something. If it's a type, then we have a class
1875     // message. Otherwise, it's an instance message.
1876     NamedDecl *ND = Result.getFoundDecl();
1877     QualType T;
1878     if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
1879       T = Context.getObjCInterfaceType(Class);
1880     else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND)) {
1881       T = Context.getTypeDeclType(Type);
1882       DiagnoseUseOfDecl(Type, NameLoc);
1883     }
1884     else
1885       return ObjCInstanceMessage;
1886 
1887     //  We have a class message, and T is the type we're
1888     //  messaging. Build source-location information for it.
1889     TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1890     ReceiverType = CreateParsedType(T, TSInfo);
1891     return ObjCClassMessage;
1892   }
1893   }
1894 
1895   ObjCInterfaceOrSuperCCC Validator(getCurMethodDecl());
1896   if (TypoCorrection Corrected =
1897           CorrectTypo(Result.getLookupNameInfo(), Result.getLookupKind(), S,
1898                       nullptr, Validator, CTK_ErrorRecovery, nullptr, false,
1899                       nullptr, false)) {
1900     if (Corrected.isKeyword()) {
1901       // If we've found the keyword "super" (the only keyword that would be
1902       // returned by CorrectTypo), this is a send to super.
1903       diagnoseTypo(Corrected,
1904                    PDiag(diag::err_unknown_receiver_suggest) << Name);
1905       return ObjCSuperMessage;
1906     } else if (ObjCInterfaceDecl *Class =
1907                    Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1908       // If we found a declaration, correct when it refers to an Objective-C
1909       // class.
1910       diagnoseTypo(Corrected,
1911                    PDiag(diag::err_unknown_receiver_suggest) << Name);
1912       QualType T = Context.getObjCInterfaceType(Class);
1913       TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
1914       ReceiverType = CreateParsedType(T, TSInfo);
1915       return ObjCClassMessage;
1916     }
1917   }
1918 
1919   // Fall back: let the parser try to parse it as an instance message.
1920   return ObjCInstanceMessage;
1921 }
1922 
ActOnSuperMessage(Scope * S,SourceLocation SuperLoc,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)1923 ExprResult Sema::ActOnSuperMessage(Scope *S,
1924                                    SourceLocation SuperLoc,
1925                                    Selector Sel,
1926                                    SourceLocation LBracLoc,
1927                                    ArrayRef<SourceLocation> SelectorLocs,
1928                                    SourceLocation RBracLoc,
1929                                    MultiExprArg Args) {
1930   // Determine whether we are inside a method or not.
1931   ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
1932   if (!Method) {
1933     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
1934     return ExprError();
1935   }
1936 
1937   ObjCInterfaceDecl *Class = Method->getClassInterface();
1938   if (!Class) {
1939     Diag(SuperLoc, diag::error_no_super_class_message)
1940       << Method->getDeclName();
1941     return ExprError();
1942   }
1943 
1944   ObjCInterfaceDecl *Super = Class->getSuperClass();
1945   if (!Super) {
1946     // The current class does not have a superclass.
1947     Diag(SuperLoc, diag::error_root_class_cannot_use_super)
1948       << Class->getIdentifier();
1949     return ExprError();
1950   }
1951 
1952   // We are in a method whose class has a superclass, so 'super'
1953   // is acting as a keyword.
1954   if (Method->getSelector() == Sel)
1955     getCurFunction()->ObjCShouldCallSuper = false;
1956 
1957   if (Method->isInstanceMethod()) {
1958     // Since we are in an instance method, this is an instance
1959     // message to the superclass instance.
1960     QualType SuperTy = Context.getObjCInterfaceType(Super);
1961     SuperTy = Context.getObjCObjectPointerType(SuperTy);
1962     return BuildInstanceMessage(nullptr, SuperTy, SuperLoc,
1963                                 Sel, /*Method=*/nullptr,
1964                                 LBracLoc, SelectorLocs, RBracLoc, Args);
1965   }
1966 
1967   // Since we are in a class method, this is a class message to
1968   // the superclass.
1969   return BuildClassMessage(/*ReceiverTypeInfo=*/nullptr,
1970                            Context.getObjCInterfaceType(Super),
1971                            SuperLoc, Sel, /*Method=*/nullptr,
1972                            LBracLoc, SelectorLocs, RBracLoc, Args);
1973 }
1974 
1975 
BuildClassMessageImplicit(QualType ReceiverType,bool isSuperReceiver,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)1976 ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
1977                                            bool isSuperReceiver,
1978                                            SourceLocation Loc,
1979                                            Selector Sel,
1980                                            ObjCMethodDecl *Method,
1981                                            MultiExprArg Args) {
1982   TypeSourceInfo *receiverTypeInfo = nullptr;
1983   if (!ReceiverType.isNull())
1984     receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
1985 
1986   return BuildClassMessage(receiverTypeInfo, ReceiverType,
1987                           /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
1988                            Sel, Method, Loc, Loc, Loc, Args,
1989                            /*isImplicit=*/true);
1990 
1991 }
1992 
applyCocoaAPICheck(Sema & S,const ObjCMessageExpr * Msg,unsigned DiagID,bool (* refactor)(const ObjCMessageExpr *,const NSAPI &,edit::Commit &))1993 static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
1994                                unsigned DiagID,
1995                                bool (*refactor)(const ObjCMessageExpr *,
1996                                               const NSAPI &, edit::Commit &)) {
1997   SourceLocation MsgLoc = Msg->getExprLoc();
1998   if (S.Diags.isIgnored(DiagID, MsgLoc))
1999     return;
2000 
2001   SourceManager &SM = S.SourceMgr;
2002   edit::Commit ECommit(SM, S.LangOpts);
2003   if (refactor(Msg,*S.NSAPIObj, ECommit)) {
2004     DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
2005                         << Msg->getSelector() << Msg->getSourceRange();
2006     // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
2007     if (!ECommit.isCommitable())
2008       return;
2009     for (edit::Commit::edit_iterator
2010            I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
2011       const edit::Commit::Edit &Edit = *I;
2012       switch (Edit.Kind) {
2013       case edit::Commit::Act_Insert:
2014         Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
2015                                                         Edit.Text,
2016                                                         Edit.BeforePrev));
2017         break;
2018       case edit::Commit::Act_InsertFromRange:
2019         Builder.AddFixItHint(
2020             FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
2021                                                 Edit.getInsertFromRange(SM),
2022                                                 Edit.BeforePrev));
2023         break;
2024       case edit::Commit::Act_Remove:
2025         Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
2026         break;
2027       }
2028     }
2029   }
2030 }
2031 
checkCocoaAPI(Sema & S,const ObjCMessageExpr * Msg)2032 static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
2033   applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
2034                      edit::rewriteObjCRedundantCallWithLiteral);
2035 }
2036 
2037 /// \brief Build an Objective-C class message expression.
2038 ///
2039 /// This routine takes care of both normal class messages and
2040 /// class messages to the superclass.
2041 ///
2042 /// \param ReceiverTypeInfo Type source information that describes the
2043 /// receiver of this message. This may be NULL, in which case we are
2044 /// sending to the superclass and \p SuperLoc must be a valid source
2045 /// location.
2046 
2047 /// \param ReceiverType The type of the object receiving the
2048 /// message. When \p ReceiverTypeInfo is non-NULL, this is the same
2049 /// type as that refers to. For a superclass send, this is the type of
2050 /// the superclass.
2051 ///
2052 /// \param SuperLoc The location of the "super" keyword in a
2053 /// superclass message.
2054 ///
2055 /// \param Sel The selector to which the message is being sent.
2056 ///
2057 /// \param Method The method that this class message is invoking, if
2058 /// already known.
2059 ///
2060 /// \param LBracLoc The location of the opening square bracket ']'.
2061 ///
2062 /// \param RBracLoc The location of the closing square bracket ']'.
2063 ///
2064 /// \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)2065 ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
2066                                    QualType ReceiverType,
2067                                    SourceLocation SuperLoc,
2068                                    Selector Sel,
2069                                    ObjCMethodDecl *Method,
2070                                    SourceLocation LBracLoc,
2071                                    ArrayRef<SourceLocation> SelectorLocs,
2072                                    SourceLocation RBracLoc,
2073                                    MultiExprArg ArgsIn,
2074                                    bool isImplicit) {
2075   SourceLocation Loc = SuperLoc.isValid()? SuperLoc
2076     : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
2077   if (LBracLoc.isInvalid()) {
2078     Diag(Loc, diag::err_missing_open_square_message_send)
2079       << FixItHint::CreateInsertion(Loc, "[");
2080     LBracLoc = Loc;
2081   }
2082   SourceLocation SelLoc;
2083   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2084     SelLoc = SelectorLocs.front();
2085   else
2086     SelLoc = Loc;
2087 
2088   if (ReceiverType->isDependentType()) {
2089     // If the receiver type is dependent, we can't type-check anything
2090     // at this point. Build a dependent expression.
2091     unsigned NumArgs = ArgsIn.size();
2092     Expr **Args = ArgsIn.data();
2093     assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2094     return ObjCMessageExpr::Create(
2095         Context, ReceiverType, VK_RValue, LBracLoc, ReceiverTypeInfo, Sel,
2096         SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs), RBracLoc,
2097         isImplicit);
2098   }
2099 
2100   // Find the class to which we are sending this message.
2101   ObjCInterfaceDecl *Class = nullptr;
2102   const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
2103   if (!ClassType || !(Class = ClassType->getInterface())) {
2104     Diag(Loc, diag::err_invalid_receiver_class_message)
2105       << ReceiverType;
2106     return ExprError();
2107   }
2108   assert(Class && "We don't know which class we're messaging?");
2109   // objc++ diagnoses during typename annotation.
2110   if (!getLangOpts().CPlusPlus)
2111     (void)DiagnoseUseOfDecl(Class, SelLoc);
2112   // Find the method we are messaging.
2113   if (!Method) {
2114     SourceRange TypeRange
2115       = SuperLoc.isValid()? SourceRange(SuperLoc)
2116                           : ReceiverTypeInfo->getTypeLoc().getSourceRange();
2117     if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
2118                             (getLangOpts().ObjCAutoRefCount
2119                                ? diag::err_arc_receiver_forward_class
2120                                : diag::warn_receiver_forward_class),
2121                             TypeRange)) {
2122       // A forward class used in messaging is treated as a 'Class'
2123       Method = LookupFactoryMethodInGlobalPool(Sel,
2124                                                SourceRange(LBracLoc, RBracLoc));
2125       if (Method && !getLangOpts().ObjCAutoRefCount)
2126         Diag(Method->getLocation(), diag::note_method_sent_forward_class)
2127           << Method->getDeclName();
2128     }
2129     if (!Method)
2130       Method = Class->lookupClassMethod(Sel);
2131 
2132     // If we have an implementation in scope, check "private" methods.
2133     if (!Method)
2134       Method = Class->lookupPrivateClassMethod(Sel);
2135 
2136     if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2137       return ExprError();
2138   }
2139 
2140   // Check the argument types and determine the result type.
2141   QualType ReturnType;
2142   ExprValueKind VK = VK_RValue;
2143 
2144   unsigned NumArgs = ArgsIn.size();
2145   Expr **Args = ArgsIn.data();
2146   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2147                                 Sel, SelectorLocs,
2148                                 Method, true,
2149                                 SuperLoc.isValid(), LBracLoc, RBracLoc,
2150                                 ReturnType, VK))
2151     return ExprError();
2152 
2153   if (Method && !Method->getReturnType()->isVoidType() &&
2154       RequireCompleteType(LBracLoc, Method->getReturnType(),
2155                           diag::err_illegal_message_expr_incomplete_type))
2156     return ExprError();
2157 
2158   // Construct the appropriate ObjCMessageExpr.
2159   ObjCMessageExpr *Result;
2160   if (SuperLoc.isValid())
2161     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2162                                      SuperLoc, /*IsInstanceSuper=*/false,
2163                                      ReceiverType, Sel, SelectorLocs,
2164                                      Method, makeArrayRef(Args, NumArgs),
2165                                      RBracLoc, isImplicit);
2166   else {
2167     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2168                                      ReceiverTypeInfo, Sel, SelectorLocs,
2169                                      Method, makeArrayRef(Args, NumArgs),
2170                                      RBracLoc, isImplicit);
2171     if (!isImplicit)
2172       checkCocoaAPI(*this, Result);
2173   }
2174   return MaybeBindToTemporary(Result);
2175 }
2176 
2177 // ActOnClassMessage - used for both unary and keyword messages.
2178 // ArgExprs is optional - if it is present, the number of expressions
2179 // is obtained from Sel.getNumArgs().
ActOnClassMessage(Scope * S,ParsedType Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2180 ExprResult Sema::ActOnClassMessage(Scope *S,
2181                                    ParsedType Receiver,
2182                                    Selector Sel,
2183                                    SourceLocation LBracLoc,
2184                                    ArrayRef<SourceLocation> SelectorLocs,
2185                                    SourceLocation RBracLoc,
2186                                    MultiExprArg Args) {
2187   TypeSourceInfo *ReceiverTypeInfo;
2188   QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
2189   if (ReceiverType.isNull())
2190     return ExprError();
2191 
2192 
2193   if (!ReceiverTypeInfo)
2194     ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
2195 
2196   return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
2197                            /*SuperLoc=*/SourceLocation(), Sel,
2198                            /*Method=*/nullptr, LBracLoc, SelectorLocs, RBracLoc,
2199                            Args);
2200 }
2201 
BuildInstanceMessageImplicit(Expr * Receiver,QualType ReceiverType,SourceLocation Loc,Selector Sel,ObjCMethodDecl * Method,MultiExprArg Args)2202 ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
2203                                               QualType ReceiverType,
2204                                               SourceLocation Loc,
2205                                               Selector Sel,
2206                                               ObjCMethodDecl *Method,
2207                                               MultiExprArg Args) {
2208   return BuildInstanceMessage(Receiver, ReceiverType,
2209                               /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
2210                               Sel, Method, Loc, Loc, Loc, Args,
2211                               /*isImplicit=*/true);
2212 }
2213 
2214 /// \brief Build an Objective-C instance message expression.
2215 ///
2216 /// This routine takes care of both normal instance messages and
2217 /// instance messages to the superclass instance.
2218 ///
2219 /// \param Receiver The expression that computes the object that will
2220 /// receive this message. This may be empty, in which case we are
2221 /// sending to the superclass instance and \p SuperLoc must be a valid
2222 /// source location.
2223 ///
2224 /// \param ReceiverType The (static) type of the object receiving the
2225 /// message. When a \p Receiver expression is provided, this is the
2226 /// same type as that expression. For a superclass instance send, this
2227 /// is a pointer to the type of the superclass.
2228 ///
2229 /// \param SuperLoc The location of the "super" keyword in a
2230 /// superclass instance message.
2231 ///
2232 /// \param Sel The selector to which the message is being sent.
2233 ///
2234 /// \param Method The method that this instance message is invoking, if
2235 /// already known.
2236 ///
2237 /// \param LBracLoc The location of the opening square bracket ']'.
2238 ///
2239 /// \param RBracLoc The location of the closing square bracket ']'.
2240 ///
2241 /// \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)2242 ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
2243                                       QualType ReceiverType,
2244                                       SourceLocation SuperLoc,
2245                                       Selector Sel,
2246                                       ObjCMethodDecl *Method,
2247                                       SourceLocation LBracLoc,
2248                                       ArrayRef<SourceLocation> SelectorLocs,
2249                                       SourceLocation RBracLoc,
2250                                       MultiExprArg ArgsIn,
2251                                       bool isImplicit) {
2252   // The location of the receiver.
2253   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
2254   SourceRange RecRange =
2255       SuperLoc.isValid()? SuperLoc : Receiver->getSourceRange();
2256   SourceLocation SelLoc;
2257   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2258     SelLoc = SelectorLocs.front();
2259   else
2260     SelLoc = Loc;
2261 
2262   if (LBracLoc.isInvalid()) {
2263     Diag(Loc, diag::err_missing_open_square_message_send)
2264       << FixItHint::CreateInsertion(Loc, "[");
2265     LBracLoc = Loc;
2266   }
2267 
2268   // If we have a receiver expression, perform appropriate promotions
2269   // and determine receiver type.
2270   if (Receiver) {
2271     if (Receiver->hasPlaceholderType()) {
2272       ExprResult Result;
2273       if (Receiver->getType() == Context.UnknownAnyTy)
2274         Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
2275       else
2276         Result = CheckPlaceholderExpr(Receiver);
2277       if (Result.isInvalid()) return ExprError();
2278       Receiver = Result.get();
2279     }
2280 
2281     if (Receiver->isTypeDependent()) {
2282       // If the receiver is type-dependent, we can't type-check anything
2283       // at this point. Build a dependent expression.
2284       unsigned NumArgs = ArgsIn.size();
2285       Expr **Args = ArgsIn.data();
2286       assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2287       return ObjCMessageExpr::Create(
2288           Context, Context.DependentTy, VK_RValue, LBracLoc, Receiver, Sel,
2289           SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs),
2290           RBracLoc, isImplicit);
2291     }
2292 
2293     // If necessary, apply function/array conversion to the receiver.
2294     // C99 6.7.5.3p[7,8].
2295     ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
2296     if (Result.isInvalid())
2297       return ExprError();
2298     Receiver = Result.get();
2299     ReceiverType = Receiver->getType();
2300 
2301     // If the receiver is an ObjC pointer, a block pointer, or an
2302     // __attribute__((NSObject)) pointer, we don't need to do any
2303     // special conversion in order to look up a receiver.
2304     if (ReceiverType->isObjCRetainableType()) {
2305       // do nothing
2306     } else if (!getLangOpts().ObjCAutoRefCount &&
2307                !Context.getObjCIdType().isNull() &&
2308                (ReceiverType->isPointerType() ||
2309                 ReceiverType->isIntegerType())) {
2310       // Implicitly convert integers and pointers to 'id' but emit a warning.
2311       // But not in ARC.
2312       Diag(Loc, diag::warn_bad_receiver_type)
2313         << ReceiverType
2314         << Receiver->getSourceRange();
2315       if (ReceiverType->isPointerType()) {
2316         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2317                                      CK_CPointerToObjCPointerCast).get();
2318       } else {
2319         // TODO: specialized warning on null receivers?
2320         bool IsNull = Receiver->isNullPointerConstant(Context,
2321                                               Expr::NPC_ValueDependentIsNull);
2322         CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
2323         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2324                                      Kind).get();
2325       }
2326       ReceiverType = Receiver->getType();
2327     } else if (getLangOpts().CPlusPlus) {
2328       // The receiver must be a complete type.
2329       if (RequireCompleteType(Loc, Receiver->getType(),
2330                               diag::err_incomplete_receiver_type))
2331         return ExprError();
2332 
2333       ExprResult result = PerformContextuallyConvertToObjCPointer(Receiver);
2334       if (result.isUsable()) {
2335         Receiver = result.get();
2336         ReceiverType = Receiver->getType();
2337       }
2338     }
2339   }
2340 
2341   // There's a somewhat weird interaction here where we assume that we
2342   // won't actually have a method unless we also don't need to do some
2343   // of the more detailed type-checking on the receiver.
2344 
2345   if (!Method) {
2346     // Handle messages to id.
2347     bool receiverIsId = ReceiverType->isObjCIdType();
2348     if (receiverIsId || ReceiverType->isBlockPointerType() ||
2349         (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
2350       Method = LookupInstanceMethodInGlobalPool(Sel,
2351                                                 SourceRange(LBracLoc, RBracLoc),
2352                                                 receiverIsId);
2353       if (!Method)
2354         Method = LookupFactoryMethodInGlobalPool(Sel,
2355                                                  SourceRange(LBracLoc,RBracLoc),
2356                                                  receiverIsId);
2357     } else if (ReceiverType->isObjCClassType() ||
2358                ReceiverType->isObjCQualifiedClassType()) {
2359       // Handle messages to Class.
2360       // We allow sending a message to a qualified Class ("Class<foo>"), which
2361       // is ok as long as one of the protocols implements the selector (if not, warn).
2362       if (const ObjCObjectPointerType *QClassTy
2363             = ReceiverType->getAsObjCQualifiedClassType()) {
2364         // Search protocols for class methods.
2365         Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
2366         if (!Method) {
2367           Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
2368           // warn if instance method found for a Class message.
2369           if (Method) {
2370             Diag(SelLoc, diag::warn_instance_method_on_class_found)
2371               << Method->getSelector() << Sel;
2372             Diag(Method->getLocation(), diag::note_method_declared_at)
2373               << Method->getDeclName();
2374           }
2375         }
2376       } else {
2377         if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2378           if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
2379             // First check the public methods in the class interface.
2380             Method = ClassDecl->lookupClassMethod(Sel);
2381 
2382             if (!Method)
2383               Method = ClassDecl->lookupPrivateClassMethod(Sel);
2384           }
2385           if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2386             return ExprError();
2387         }
2388         if (!Method) {
2389           // If not messaging 'self', look for any factory method named 'Sel'.
2390           if (!Receiver || !isSelfExpr(Receiver)) {
2391             Method = LookupFactoryMethodInGlobalPool(Sel,
2392                                                 SourceRange(LBracLoc, RBracLoc),
2393                                                      true);
2394             if (!Method) {
2395               // If no class (factory) method was found, check if an _instance_
2396               // method of the same name exists in the root class only.
2397               Method = LookupInstanceMethodInGlobalPool(Sel,
2398                                                SourceRange(LBracLoc, RBracLoc),
2399                                                         true);
2400               if (Method)
2401                   if (const ObjCInterfaceDecl *ID =
2402                       dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
2403                     if (ID->getSuperClass())
2404                       Diag(SelLoc, diag::warn_root_inst_method_not_found)
2405                       << Sel << SourceRange(LBracLoc, RBracLoc);
2406                   }
2407             }
2408           }
2409         }
2410       }
2411     } else {
2412       ObjCInterfaceDecl *ClassDecl = nullptr;
2413 
2414       // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
2415       // long as one of the protocols implements the selector (if not, warn).
2416       // And as long as message is not deprecated/unavailable (warn if it is).
2417       if (const ObjCObjectPointerType *QIdTy
2418                                    = ReceiverType->getAsObjCQualifiedIdType()) {
2419         // Search protocols for instance methods.
2420         Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
2421         if (!Method)
2422           Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
2423         if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2424           return ExprError();
2425       } else if (const ObjCObjectPointerType *OCIType
2426                    = ReceiverType->getAsObjCInterfacePointerType()) {
2427         // We allow sending a message to a pointer to an interface (an object).
2428         ClassDecl = OCIType->getInterfaceDecl();
2429 
2430         // Try to complete the type. Under ARC, this is a hard error from which
2431         // we don't try to recover.
2432         const ObjCInterfaceDecl *forwardClass = nullptr;
2433         if (RequireCompleteType(Loc, OCIType->getPointeeType(),
2434               getLangOpts().ObjCAutoRefCount
2435                 ? diag::err_arc_receiver_forward_instance
2436                 : diag::warn_receiver_forward_instance,
2437                                 Receiver? Receiver->getSourceRange()
2438                                         : SourceRange(SuperLoc))) {
2439           if (getLangOpts().ObjCAutoRefCount)
2440             return ExprError();
2441 
2442           forwardClass = OCIType->getInterfaceDecl();
2443           Diag(Receiver ? Receiver->getLocStart()
2444                         : SuperLoc, diag::note_receiver_is_id);
2445           Method = nullptr;
2446         } else {
2447           Method = ClassDecl->lookupInstanceMethod(Sel);
2448         }
2449 
2450         if (!Method)
2451           // Search protocol qualifiers.
2452           Method = LookupMethodInQualifiedType(Sel, OCIType, true);
2453 
2454         if (!Method) {
2455           // If we have implementations in scope, check "private" methods.
2456           Method = ClassDecl->lookupPrivateMethod(Sel);
2457 
2458           if (!Method && getLangOpts().ObjCAutoRefCount) {
2459             Diag(SelLoc, diag::err_arc_may_not_respond)
2460               << OCIType->getPointeeType() << Sel << RecRange
2461               << SourceRange(SelectorLocs.front(), SelectorLocs.back());
2462             return ExprError();
2463           }
2464 
2465           if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
2466             // If we still haven't found a method, look in the global pool. This
2467             // behavior isn't very desirable, however we need it for GCC
2468             // compatibility. FIXME: should we deviate??
2469             if (OCIType->qual_empty()) {
2470               Method = LookupInstanceMethodInGlobalPool(Sel,
2471                                               SourceRange(LBracLoc, RBracLoc));
2472               if (Method && !forwardClass)
2473                 Diag(SelLoc, diag::warn_maynot_respond)
2474                   << OCIType->getInterfaceDecl()->getIdentifier()
2475                   << Sel << RecRange;
2476             }
2477           }
2478         }
2479         if (Method && DiagnoseUseOfDecl(Method, SelLoc, forwardClass))
2480           return ExprError();
2481       } else {
2482         // Reject other random receiver types (e.g. structs).
2483         Diag(Loc, diag::err_bad_receiver_type)
2484           << ReceiverType << Receiver->getSourceRange();
2485         return ExprError();
2486       }
2487     }
2488   }
2489 
2490   FunctionScopeInfo *DIFunctionScopeInfo =
2491     (Method && Method->getMethodFamily() == OMF_init)
2492       ? getEnclosingFunction() : nullptr;
2493 
2494   if (DIFunctionScopeInfo &&
2495       DIFunctionScopeInfo->ObjCIsDesignatedInit &&
2496       (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2497     bool isDesignatedInitChain = false;
2498     if (SuperLoc.isValid()) {
2499       if (const ObjCObjectPointerType *
2500             OCIType = ReceiverType->getAsObjCInterfacePointerType()) {
2501         if (const ObjCInterfaceDecl *ID = OCIType->getInterfaceDecl()) {
2502           // Either we know this is a designated initializer or we
2503           // conservatively assume it because we don't know for sure.
2504           if (!ID->declaresOrInheritsDesignatedInitializers() ||
2505               ID->isDesignatedInitializer(Sel)) {
2506             isDesignatedInitChain = true;
2507             DIFunctionScopeInfo->ObjCWarnForNoDesignatedInitChain = false;
2508           }
2509         }
2510       }
2511     }
2512     if (!isDesignatedInitChain) {
2513       const ObjCMethodDecl *InitMethod = nullptr;
2514       bool isDesignated =
2515         getCurMethodDecl()->isDesignatedInitializerForTheInterface(&InitMethod);
2516       assert(isDesignated && InitMethod);
2517       (void)isDesignated;
2518       Diag(SelLoc, SuperLoc.isValid() ?
2519              diag::warn_objc_designated_init_non_designated_init_call :
2520              diag::warn_objc_designated_init_non_super_designated_init_call);
2521       Diag(InitMethod->getLocation(),
2522            diag::note_objc_designated_init_marked_here);
2523     }
2524   }
2525 
2526   if (DIFunctionScopeInfo &&
2527       DIFunctionScopeInfo->ObjCIsSecondaryInit &&
2528       (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2529     if (SuperLoc.isValid()) {
2530       Diag(SelLoc, diag::warn_objc_secondary_init_super_init_call);
2531     } else {
2532       DIFunctionScopeInfo->ObjCWarnForNoInitDelegation = false;
2533     }
2534   }
2535 
2536   // Check the message arguments.
2537   unsigned NumArgs = ArgsIn.size();
2538   Expr **Args = ArgsIn.data();
2539   QualType ReturnType;
2540   ExprValueKind VK = VK_RValue;
2541   bool ClassMessage = (ReceiverType->isObjCClassType() ||
2542                        ReceiverType->isObjCQualifiedClassType());
2543   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2544                                 Sel, SelectorLocs, Method,
2545                                 ClassMessage, SuperLoc.isValid(),
2546                                 LBracLoc, RBracLoc, ReturnType, VK))
2547     return ExprError();
2548 
2549   if (Method && !Method->getReturnType()->isVoidType() &&
2550       RequireCompleteType(LBracLoc, Method->getReturnType(),
2551                           diag::err_illegal_message_expr_incomplete_type))
2552     return ExprError();
2553 
2554   // In ARC, forbid the user from sending messages to
2555   // retain/release/autorelease/dealloc/retainCount explicitly.
2556   if (getLangOpts().ObjCAutoRefCount) {
2557     ObjCMethodFamily family =
2558       (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
2559     switch (family) {
2560     case OMF_init:
2561       if (Method)
2562         checkInitMethod(Method, ReceiverType);
2563 
2564     case OMF_None:
2565     case OMF_alloc:
2566     case OMF_copy:
2567     case OMF_finalize:
2568     case OMF_mutableCopy:
2569     case OMF_new:
2570     case OMF_self:
2571       break;
2572 
2573     case OMF_dealloc:
2574     case OMF_retain:
2575     case OMF_release:
2576     case OMF_autorelease:
2577     case OMF_retainCount:
2578       Diag(SelLoc, diag::err_arc_illegal_explicit_message)
2579         << Sel << RecRange;
2580       break;
2581 
2582     case OMF_performSelector:
2583       if (Method && NumArgs >= 1) {
2584         if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
2585           Selector ArgSel = SelExp->getSelector();
2586           ObjCMethodDecl *SelMethod =
2587             LookupInstanceMethodInGlobalPool(ArgSel,
2588                                              SelExp->getSourceRange());
2589           if (!SelMethod)
2590             SelMethod =
2591               LookupFactoryMethodInGlobalPool(ArgSel,
2592                                               SelExp->getSourceRange());
2593           if (SelMethod) {
2594             ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
2595             switch (SelFamily) {
2596               case OMF_alloc:
2597               case OMF_copy:
2598               case OMF_mutableCopy:
2599               case OMF_new:
2600               case OMF_self:
2601               case OMF_init:
2602                 // Issue error, unless ns_returns_not_retained.
2603                 if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
2604                   // selector names a +1 method
2605                   Diag(SelLoc,
2606                        diag::err_arc_perform_selector_retains);
2607                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2608                     << SelMethod->getDeclName();
2609                 }
2610                 break;
2611               default:
2612                 // +0 call. OK. unless ns_returns_retained.
2613                 if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
2614                   // selector names a +1 method
2615                   Diag(SelLoc,
2616                        diag::err_arc_perform_selector_retains);
2617                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2618                     << SelMethod->getDeclName();
2619                 }
2620                 break;
2621             }
2622           }
2623         } else {
2624           // error (may leak).
2625           Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
2626           Diag(Args[0]->getExprLoc(), diag::note_used_here);
2627         }
2628       }
2629       break;
2630     }
2631   }
2632 
2633   // Construct the appropriate ObjCMessageExpr instance.
2634   ObjCMessageExpr *Result;
2635   if (SuperLoc.isValid())
2636     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2637                                      SuperLoc,  /*IsInstanceSuper=*/true,
2638                                      ReceiverType, Sel, SelectorLocs, Method,
2639                                      makeArrayRef(Args, NumArgs), RBracLoc,
2640                                      isImplicit);
2641   else {
2642     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2643                                      Receiver, Sel, SelectorLocs, Method,
2644                                      makeArrayRef(Args, NumArgs), RBracLoc,
2645                                      isImplicit);
2646     if (!isImplicit)
2647       checkCocoaAPI(*this, Result);
2648   }
2649 
2650   if (getLangOpts().ObjCAutoRefCount) {
2651     // Do not warn about IBOutlet weak property receivers being set to null
2652     // as this cannot asynchronously happen.
2653     bool WarnWeakReceiver = true;
2654     if (isImplicit && Method)
2655       if (const ObjCPropertyDecl *PropertyDecl = Method->findPropertyDecl())
2656         WarnWeakReceiver = !PropertyDecl->hasAttr<IBOutletAttr>();
2657     if (WarnWeakReceiver)
2658       DiagnoseARCUseOfWeakReceiver(*this, Receiver);
2659 
2660     // In ARC, annotate delegate init calls.
2661     if (Result->getMethodFamily() == OMF_init &&
2662         (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2663       // Only consider init calls *directly* in init implementations,
2664       // not within blocks.
2665       ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
2666       if (method && method->getMethodFamily() == OMF_init) {
2667         // The implicit assignment to self means we also don't want to
2668         // consume the result.
2669         Result->setDelegateInitCall(true);
2670         return Result;
2671       }
2672     }
2673 
2674     // In ARC, check for message sends which are likely to introduce
2675     // retain cycles.
2676     checkRetainCycles(Result);
2677 
2678     if (!isImplicit && Method) {
2679       if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
2680         bool IsWeak =
2681           Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
2682         if (!IsWeak && Sel.isUnarySelector())
2683           IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
2684         if (IsWeak &&
2685             !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, LBracLoc))
2686           getCurFunction()->recordUseOfWeak(Result, Prop);
2687       }
2688     }
2689   }
2690 
2691   return MaybeBindToTemporary(Result);
2692 }
2693 
RemoveSelectorFromWarningCache(Sema & S,Expr * Arg)2694 static void RemoveSelectorFromWarningCache(Sema &S, Expr* Arg) {
2695   if (ObjCSelectorExpr *OSE =
2696       dyn_cast<ObjCSelectorExpr>(Arg->IgnoreParenCasts())) {
2697     Selector Sel = OSE->getSelector();
2698     SourceLocation Loc = OSE->getAtLoc();
2699     llvm::DenseMap<Selector, SourceLocation>::iterator Pos
2700     = S.ReferencedSelectors.find(Sel);
2701     if (Pos != S.ReferencedSelectors.end() && Pos->second == Loc)
2702       S.ReferencedSelectors.erase(Pos);
2703   }
2704 }
2705 
2706 // ActOnInstanceMessage - used for both unary and keyword messages.
2707 // ArgExprs is optional - if it is present, the number of expressions
2708 // is obtained from Sel.getNumArgs().
ActOnInstanceMessage(Scope * S,Expr * Receiver,Selector Sel,SourceLocation LBracLoc,ArrayRef<SourceLocation> SelectorLocs,SourceLocation RBracLoc,MultiExprArg Args)2709 ExprResult Sema::ActOnInstanceMessage(Scope *S,
2710                                       Expr *Receiver,
2711                                       Selector Sel,
2712                                       SourceLocation LBracLoc,
2713                                       ArrayRef<SourceLocation> SelectorLocs,
2714                                       SourceLocation RBracLoc,
2715                                       MultiExprArg Args) {
2716   if (!Receiver)
2717     return ExprError();
2718 
2719   // A ParenListExpr can show up while doing error recovery with invalid code.
2720   if (isa<ParenListExpr>(Receiver)) {
2721     ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Receiver);
2722     if (Result.isInvalid()) return ExprError();
2723     Receiver = Result.get();
2724   }
2725 
2726   if (RespondsToSelectorSel.isNull()) {
2727     IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
2728     RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
2729   }
2730   if (Sel == RespondsToSelectorSel)
2731     RemoveSelectorFromWarningCache(*this, Args[0]);
2732 
2733   return BuildInstanceMessage(Receiver, Receiver->getType(),
2734                               /*SuperLoc=*/SourceLocation(), Sel,
2735                               /*Method=*/nullptr, LBracLoc, SelectorLocs,
2736                               RBracLoc, Args);
2737 }
2738 
2739 enum ARCConversionTypeClass {
2740   /// int, void, struct A
2741   ACTC_none,
2742 
2743   /// id, void (^)()
2744   ACTC_retainable,
2745 
2746   /// id*, id***, void (^*)(),
2747   ACTC_indirectRetainable,
2748 
2749   /// void* might be a normal C type, or it might a CF type.
2750   ACTC_voidPtr,
2751 
2752   /// struct A*
2753   ACTC_coreFoundation
2754 };
isAnyRetainable(ARCConversionTypeClass ACTC)2755 static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
2756   return (ACTC == ACTC_retainable ||
2757           ACTC == ACTC_coreFoundation ||
2758           ACTC == ACTC_voidPtr);
2759 }
isAnyCLike(ARCConversionTypeClass ACTC)2760 static bool isAnyCLike(ARCConversionTypeClass ACTC) {
2761   return ACTC == ACTC_none ||
2762          ACTC == ACTC_voidPtr ||
2763          ACTC == ACTC_coreFoundation;
2764 }
2765 
classifyTypeForARCConversion(QualType type)2766 static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
2767   bool isIndirect = false;
2768 
2769   // Ignore an outermost reference type.
2770   if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
2771     type = ref->getPointeeType();
2772     isIndirect = true;
2773   }
2774 
2775   // Drill through pointers and arrays recursively.
2776   while (true) {
2777     if (const PointerType *ptr = type->getAs<PointerType>()) {
2778       type = ptr->getPointeeType();
2779 
2780       // The first level of pointer may be the innermost pointer on a CF type.
2781       if (!isIndirect) {
2782         if (type->isVoidType()) return ACTC_voidPtr;
2783         if (type->isRecordType()) return ACTC_coreFoundation;
2784       }
2785     } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
2786       type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
2787     } else {
2788       break;
2789     }
2790     isIndirect = true;
2791   }
2792 
2793   if (isIndirect) {
2794     if (type->isObjCARCBridgableType())
2795       return ACTC_indirectRetainable;
2796     return ACTC_none;
2797   }
2798 
2799   if (type->isObjCARCBridgableType())
2800     return ACTC_retainable;
2801 
2802   return ACTC_none;
2803 }
2804 
2805 namespace {
2806   /// A result from the cast checker.
2807   enum ACCResult {
2808     /// Cannot be casted.
2809     ACC_invalid,
2810 
2811     /// Can be safely retained or not retained.
2812     ACC_bottom,
2813 
2814     /// Can be casted at +0.
2815     ACC_plusZero,
2816 
2817     /// Can be casted at +1.
2818     ACC_plusOne
2819   };
merge(ACCResult left,ACCResult right)2820   ACCResult merge(ACCResult left, ACCResult right) {
2821     if (left == right) return left;
2822     if (left == ACC_bottom) return right;
2823     if (right == ACC_bottom) return left;
2824     return ACC_invalid;
2825   }
2826 
2827   /// A checker which white-lists certain expressions whose conversion
2828   /// to or from retainable type would otherwise be forbidden in ARC.
2829   class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
2830     typedef StmtVisitor<ARCCastChecker, ACCResult> super;
2831 
2832     ASTContext &Context;
2833     ARCConversionTypeClass SourceClass;
2834     ARCConversionTypeClass TargetClass;
2835     bool Diagnose;
2836 
isCFType(QualType type)2837     static bool isCFType(QualType type) {
2838       // Someday this can use ns_bridged.  For now, it has to do this.
2839       return type->isCARCBridgableType();
2840     }
2841 
2842   public:
ARCCastChecker(ASTContext & Context,ARCConversionTypeClass source,ARCConversionTypeClass target,bool diagnose)2843     ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
2844                    ARCConversionTypeClass target, bool diagnose)
2845       : Context(Context), SourceClass(source), TargetClass(target),
2846         Diagnose(diagnose) {}
2847 
2848     using super::Visit;
Visit(Expr * e)2849     ACCResult Visit(Expr *e) {
2850       return super::Visit(e->IgnoreParens());
2851     }
2852 
VisitStmt(Stmt * s)2853     ACCResult VisitStmt(Stmt *s) {
2854       return ACC_invalid;
2855     }
2856 
2857     /// Null pointer constants can be casted however you please.
VisitExpr(Expr * e)2858     ACCResult VisitExpr(Expr *e) {
2859       if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
2860         return ACC_bottom;
2861       return ACC_invalid;
2862     }
2863 
2864     /// Objective-C string literals can be safely casted.
VisitObjCStringLiteral(ObjCStringLiteral * e)2865     ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
2866       // If we're casting to any retainable type, go ahead.  Global
2867       // strings are immune to retains, so this is bottom.
2868       if (isAnyRetainable(TargetClass)) return ACC_bottom;
2869 
2870       return ACC_invalid;
2871     }
2872 
2873     /// Look through certain implicit and explicit casts.
VisitCastExpr(CastExpr * e)2874     ACCResult VisitCastExpr(CastExpr *e) {
2875       switch (e->getCastKind()) {
2876         case CK_NullToPointer:
2877           return ACC_bottom;
2878 
2879         case CK_NoOp:
2880         case CK_LValueToRValue:
2881         case CK_BitCast:
2882         case CK_CPointerToObjCPointerCast:
2883         case CK_BlockPointerToObjCPointerCast:
2884         case CK_AnyPointerToBlockPointerCast:
2885           return Visit(e->getSubExpr());
2886 
2887         default:
2888           return ACC_invalid;
2889       }
2890     }
2891 
2892     /// Look through unary extension.
VisitUnaryExtension(UnaryOperator * e)2893     ACCResult VisitUnaryExtension(UnaryOperator *e) {
2894       return Visit(e->getSubExpr());
2895     }
2896 
2897     /// Ignore the LHS of a comma operator.
VisitBinComma(BinaryOperator * e)2898     ACCResult VisitBinComma(BinaryOperator *e) {
2899       return Visit(e->getRHS());
2900     }
2901 
2902     /// Conditional operators are okay if both sides are okay.
VisitConditionalOperator(ConditionalOperator * e)2903     ACCResult VisitConditionalOperator(ConditionalOperator *e) {
2904       ACCResult left = Visit(e->getTrueExpr());
2905       if (left == ACC_invalid) return ACC_invalid;
2906       return merge(left, Visit(e->getFalseExpr()));
2907     }
2908 
2909     /// Look through pseudo-objects.
VisitPseudoObjectExpr(PseudoObjectExpr * e)2910     ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
2911       // If we're getting here, we should always have a result.
2912       return Visit(e->getResultExpr());
2913     }
2914 
2915     /// Statement expressions are okay if their result expression is okay.
VisitStmtExpr(StmtExpr * e)2916     ACCResult VisitStmtExpr(StmtExpr *e) {
2917       return Visit(e->getSubStmt()->body_back());
2918     }
2919 
2920     /// Some declaration references are okay.
VisitDeclRefExpr(DeclRefExpr * e)2921     ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
2922       // References to global constants from system headers are okay.
2923       // These are things like 'kCFStringTransformToLatin'.  They are
2924       // can also be assumed to be immune to retains.
2925       VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
2926       if (isAnyRetainable(TargetClass) &&
2927           isAnyRetainable(SourceClass) &&
2928           var &&
2929           var->getStorageClass() == SC_Extern &&
2930           var->getType().isConstQualified() &&
2931           Context.getSourceManager().isInSystemHeader(var->getLocation())) {
2932         return ACC_bottom;
2933       }
2934 
2935       // Nothing else.
2936       return ACC_invalid;
2937     }
2938 
2939     /// Some calls are okay.
VisitCallExpr(CallExpr * e)2940     ACCResult VisitCallExpr(CallExpr *e) {
2941       if (FunctionDecl *fn = e->getDirectCallee())
2942         if (ACCResult result = checkCallToFunction(fn))
2943           return result;
2944 
2945       return super::VisitCallExpr(e);
2946     }
2947 
checkCallToFunction(FunctionDecl * fn)2948     ACCResult checkCallToFunction(FunctionDecl *fn) {
2949       // Require a CF*Ref return type.
2950       if (!isCFType(fn->getReturnType()))
2951         return ACC_invalid;
2952 
2953       if (!isAnyRetainable(TargetClass))
2954         return ACC_invalid;
2955 
2956       // Honor an explicit 'not retained' attribute.
2957       if (fn->hasAttr<CFReturnsNotRetainedAttr>())
2958         return ACC_plusZero;
2959 
2960       // Honor an explicit 'retained' attribute, except that for
2961       // now we're not going to permit implicit handling of +1 results,
2962       // because it's a bit frightening.
2963       if (fn->hasAttr<CFReturnsRetainedAttr>())
2964         return Diagnose ? ACC_plusOne
2965                         : ACC_invalid; // ACC_plusOne if we start accepting this
2966 
2967       // Recognize this specific builtin function, which is used by CFSTR.
2968       unsigned builtinID = fn->getBuiltinID();
2969       if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
2970         return ACC_bottom;
2971 
2972       // Otherwise, don't do anything implicit with an unaudited function.
2973       if (!fn->hasAttr<CFAuditedTransferAttr>())
2974         return ACC_invalid;
2975 
2976       // Otherwise, it's +0 unless it follows the create convention.
2977       if (ento::coreFoundation::followsCreateRule(fn))
2978         return Diagnose ? ACC_plusOne
2979                         : ACC_invalid; // ACC_plusOne if we start accepting this
2980 
2981       return ACC_plusZero;
2982     }
2983 
VisitObjCMessageExpr(ObjCMessageExpr * e)2984     ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
2985       return checkCallToMethod(e->getMethodDecl());
2986     }
2987 
VisitObjCPropertyRefExpr(ObjCPropertyRefExpr * e)2988     ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
2989       ObjCMethodDecl *method;
2990       if (e->isExplicitProperty())
2991         method = e->getExplicitProperty()->getGetterMethodDecl();
2992       else
2993         method = e->getImplicitPropertyGetter();
2994       return checkCallToMethod(method);
2995     }
2996 
checkCallToMethod(ObjCMethodDecl * method)2997     ACCResult checkCallToMethod(ObjCMethodDecl *method) {
2998       if (!method) return ACC_invalid;
2999 
3000       // Check for message sends to functions returning CF types.  We
3001       // just obey the Cocoa conventions with these, even though the
3002       // return type is CF.
3003       if (!isAnyRetainable(TargetClass) || !isCFType(method->getReturnType()))
3004         return ACC_invalid;
3005 
3006       // If the method is explicitly marked not-retained, it's +0.
3007       if (method->hasAttr<CFReturnsNotRetainedAttr>())
3008         return ACC_plusZero;
3009 
3010       // If the method is explicitly marked as returning retained, or its
3011       // selector follows a +1 Cocoa convention, treat it as +1.
3012       if (method->hasAttr<CFReturnsRetainedAttr>())
3013         return ACC_plusOne;
3014 
3015       switch (method->getSelector().getMethodFamily()) {
3016       case OMF_alloc:
3017       case OMF_copy:
3018       case OMF_mutableCopy:
3019       case OMF_new:
3020         return ACC_plusOne;
3021 
3022       default:
3023         // Otherwise, treat it as +0.
3024         return ACC_plusZero;
3025       }
3026     }
3027   };
3028 }
3029 
isKnownName(StringRef name)3030 bool Sema::isKnownName(StringRef name) {
3031   if (name.empty())
3032     return false;
3033   LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
3034                  Sema::LookupOrdinaryName);
3035   return LookupName(R, TUScope, false);
3036 }
3037 
addFixitForObjCARCConversion(Sema & S,DiagnosticBuilder & DiagB,Sema::CheckedConversionKind CCK,SourceLocation afterLParen,QualType castType,Expr * castExpr,Expr * realCast,const char * bridgeKeyword,const char * CFBridgeName)3038 static void addFixitForObjCARCConversion(Sema &S,
3039                                          DiagnosticBuilder &DiagB,
3040                                          Sema::CheckedConversionKind CCK,
3041                                          SourceLocation afterLParen,
3042                                          QualType castType,
3043                                          Expr *castExpr,
3044                                          Expr *realCast,
3045                                          const char *bridgeKeyword,
3046                                          const char *CFBridgeName) {
3047   // We handle C-style and implicit casts here.
3048   switch (CCK) {
3049   case Sema::CCK_ImplicitConversion:
3050   case Sema::CCK_CStyleCast:
3051   case Sema::CCK_OtherCast:
3052     break;
3053   case Sema::CCK_FunctionalCast:
3054     return;
3055   }
3056 
3057   if (CFBridgeName) {
3058     if (CCK == Sema::CCK_OtherCast) {
3059       if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
3060         SourceRange range(NCE->getOperatorLoc(),
3061                           NCE->getAngleBrackets().getEnd());
3062         SmallString<32> BridgeCall;
3063 
3064         SourceManager &SM = S.getSourceManager();
3065         char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
3066         if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
3067           BridgeCall += ' ';
3068 
3069         BridgeCall += CFBridgeName;
3070         DiagB.AddFixItHint(FixItHint::CreateReplacement(range, BridgeCall));
3071       }
3072       return;
3073     }
3074     Expr *castedE = castExpr;
3075     if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
3076       castedE = CCE->getSubExpr();
3077     castedE = castedE->IgnoreImpCasts();
3078     SourceRange range = castedE->getSourceRange();
3079 
3080     SmallString<32> BridgeCall;
3081 
3082     SourceManager &SM = S.getSourceManager();
3083     char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
3084     if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
3085       BridgeCall += ' ';
3086 
3087     BridgeCall += CFBridgeName;
3088 
3089     if (isa<ParenExpr>(castedE)) {
3090       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3091                          BridgeCall));
3092     } else {
3093       BridgeCall += '(';
3094       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3095                                                     BridgeCall));
3096       DiagB.AddFixItHint(FixItHint::CreateInsertion(
3097                                        S.PP.getLocForEndOfToken(range.getEnd()),
3098                                        ")"));
3099     }
3100     return;
3101   }
3102 
3103   if (CCK == Sema::CCK_CStyleCast) {
3104     DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
3105   } else if (CCK == Sema::CCK_OtherCast) {
3106     if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
3107       std::string castCode = "(";
3108       castCode += bridgeKeyword;
3109       castCode += castType.getAsString();
3110       castCode += ")";
3111       SourceRange Range(NCE->getOperatorLoc(),
3112                         NCE->getAngleBrackets().getEnd());
3113       DiagB.AddFixItHint(FixItHint::CreateReplacement(Range, castCode));
3114     }
3115   } else {
3116     std::string castCode = "(";
3117     castCode += bridgeKeyword;
3118     castCode += castType.getAsString();
3119     castCode += ")";
3120     Expr *castedE = castExpr->IgnoreImpCasts();
3121     SourceRange range = castedE->getSourceRange();
3122     if (isa<ParenExpr>(castedE)) {
3123       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3124                          castCode));
3125     } else {
3126       castCode += "(";
3127       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3128                                                     castCode));
3129       DiagB.AddFixItHint(FixItHint::CreateInsertion(
3130                                        S.PP.getLocForEndOfToken(range.getEnd()),
3131                                        ")"));
3132     }
3133   }
3134 }
3135 
3136 template <typename T>
getObjCBridgeAttr(const TypedefType * TD)3137 static inline T *getObjCBridgeAttr(const TypedefType *TD) {
3138   TypedefNameDecl *TDNDecl = TD->getDecl();
3139   QualType QT = TDNDecl->getUnderlyingType();
3140   if (QT->isPointerType()) {
3141     QT = QT->getPointeeType();
3142     if (const RecordType *RT = QT->getAs<RecordType>())
3143       if (RecordDecl *RD = RT->getDecl()->getMostRecentDecl())
3144         return RD->getAttr<T>();
3145   }
3146   return nullptr;
3147 }
3148 
ObjCBridgeRelatedAttrFromType(QualType T,TypedefNameDecl * & TDNDecl)3149 static ObjCBridgeRelatedAttr *ObjCBridgeRelatedAttrFromType(QualType T,
3150                                                             TypedefNameDecl *&TDNDecl) {
3151   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3152     TDNDecl = TD->getDecl();
3153     if (ObjCBridgeRelatedAttr *ObjCBAttr =
3154         getObjCBridgeAttr<ObjCBridgeRelatedAttr>(TD))
3155       return ObjCBAttr;
3156     T = TDNDecl->getUnderlyingType();
3157   }
3158   return nullptr;
3159 }
3160 
3161 static void
diagnoseObjCARCConversion(Sema & S,SourceRange castRange,QualType castType,ARCConversionTypeClass castACTC,Expr * castExpr,Expr * realCast,ARCConversionTypeClass exprACTC,Sema::CheckedConversionKind CCK)3162 diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
3163                           QualType castType, ARCConversionTypeClass castACTC,
3164                           Expr *castExpr, Expr *realCast,
3165                           ARCConversionTypeClass exprACTC,
3166                           Sema::CheckedConversionKind CCK) {
3167   SourceLocation loc =
3168     (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
3169 
3170   if (S.makeUnavailableInSystemHeader(loc,
3171                 "converts between Objective-C and C pointers in -fobjc-arc"))
3172     return;
3173 
3174   QualType castExprType = castExpr->getType();
3175   TypedefNameDecl *TDNDecl = nullptr;
3176   if ((castACTC == ACTC_coreFoundation &&  exprACTC == ACTC_retainable &&
3177        ObjCBridgeRelatedAttrFromType(castType, TDNDecl)) ||
3178       (exprACTC == ACTC_coreFoundation && castACTC == ACTC_retainable &&
3179        ObjCBridgeRelatedAttrFromType(castExprType, TDNDecl)))
3180     return;
3181 
3182   unsigned srcKind = 0;
3183   switch (exprACTC) {
3184   case ACTC_none:
3185   case ACTC_coreFoundation:
3186   case ACTC_voidPtr:
3187     srcKind = (castExprType->isPointerType() ? 1 : 0);
3188     break;
3189   case ACTC_retainable:
3190     srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
3191     break;
3192   case ACTC_indirectRetainable:
3193     srcKind = 4;
3194     break;
3195   }
3196 
3197   // Check whether this could be fixed with a bridge cast.
3198   SourceLocation afterLParen = S.PP.getLocForEndOfToken(castRange.getBegin());
3199   SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
3200 
3201   // Bridge from an ARC type to a CF type.
3202   if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
3203 
3204     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3205       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3206       << 2 // of C pointer type
3207       << castExprType
3208       << unsigned(castType->isBlockPointerType()) // to ObjC|block type
3209       << castType
3210       << castRange
3211       << castExpr->getSourceRange();
3212     bool br = S.isKnownName("CFBridgingRelease");
3213     ACCResult CreateRule =
3214       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3215     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3216     if (CreateRule != ACC_plusOne)
3217     {
3218       DiagnosticBuilder DiagB =
3219         (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3220                               : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3221 
3222       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3223                                    castType, castExpr, realCast, "__bridge ",
3224                                    nullptr);
3225     }
3226     if (CreateRule != ACC_plusZero)
3227     {
3228       DiagnosticBuilder DiagB =
3229         (CCK == Sema::CCK_OtherCast && !br) ?
3230           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_transfer) << castExprType :
3231           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3232                  diag::note_arc_bridge_transfer)
3233             << castExprType << br;
3234 
3235       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3236                                    castType, castExpr, realCast, "__bridge_transfer ",
3237                                    br ? "CFBridgingRelease" : nullptr);
3238     }
3239 
3240     return;
3241   }
3242 
3243   // Bridge from a CF type to an ARC type.
3244   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
3245     bool br = S.isKnownName("CFBridgingRetain");
3246     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3247       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3248       << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
3249       << castExprType
3250       << 2 // to C pointer type
3251       << castType
3252       << castRange
3253       << castExpr->getSourceRange();
3254     ACCResult CreateRule =
3255       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3256     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3257     if (CreateRule != ACC_plusOne)
3258     {
3259       DiagnosticBuilder DiagB =
3260       (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3261                                : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3262       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3263                                    castType, castExpr, realCast, "__bridge ",
3264                                    nullptr);
3265     }
3266     if (CreateRule != ACC_plusZero)
3267     {
3268       DiagnosticBuilder DiagB =
3269         (CCK == Sema::CCK_OtherCast && !br) ?
3270           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_retained) << castType :
3271           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3272                  diag::note_arc_bridge_retained)
3273             << castType << br;
3274 
3275       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3276                                    castType, castExpr, realCast, "__bridge_retained ",
3277                                    br ? "CFBridgingRetain" : nullptr);
3278     }
3279 
3280     return;
3281   }
3282 
3283   S.Diag(loc, diag::err_arc_mismatched_cast)
3284     << (CCK != Sema::CCK_ImplicitConversion)
3285     << srcKind << castExprType << castType
3286     << castRange << castExpr->getSourceRange();
3287 }
3288 
3289 template <typename TB>
CheckObjCBridgeNSCast(Sema & S,QualType castType,Expr * castExpr,bool & HadTheAttribute,bool warn)3290 static bool CheckObjCBridgeNSCast(Sema &S, QualType castType, Expr *castExpr,
3291                                   bool &HadTheAttribute, bool warn) {
3292   QualType T = castExpr->getType();
3293   HadTheAttribute = false;
3294   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3295     TypedefNameDecl *TDNDecl = TD->getDecl();
3296     if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
3297       if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
3298         HadTheAttribute = true;
3299         NamedDecl *Target = nullptr;
3300         // Check for an existing type with this name.
3301         LookupResult R(S, DeclarationName(Parm), SourceLocation(),
3302                        Sema::LookupOrdinaryName);
3303         if (S.LookupName(R, S.TUScope)) {
3304           Target = R.getFoundDecl();
3305           if (Target && isa<ObjCInterfaceDecl>(Target)) {
3306             ObjCInterfaceDecl *ExprClass = cast<ObjCInterfaceDecl>(Target);
3307             if (const ObjCObjectPointerType *InterfacePointerType =
3308                   castType->getAsObjCInterfacePointerType()) {
3309               ObjCInterfaceDecl *CastClass
3310                 = InterfacePointerType->getObjectType()->getInterface();
3311               if ((CastClass == ExprClass) ||
3312                   (CastClass && ExprClass->isSuperClassOf(CastClass)))
3313                 return true;
3314               if (warn)
3315                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge)
3316                   << T << Target->getName() << castType->getPointeeType();
3317               return false;
3318             } else if (castType->isObjCIdType() ||
3319                        (S.Context.ObjCObjectAdoptsQTypeProtocols(
3320                           castType, ExprClass)))
3321               // ok to cast to 'id'.
3322               // casting to id<p-list> is ok if bridge type adopts all of
3323               // p-list protocols.
3324               return true;
3325             else {
3326               if (warn) {
3327                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge)
3328                   << T << Target->getName() << castType;
3329                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3330                 S.Diag(Target->getLocStart(), diag::note_declared_at);
3331               }
3332               return false;
3333            }
3334           }
3335         }
3336         S.Diag(castExpr->getLocStart(), diag::err_objc_cf_bridged_not_interface)
3337           << castExpr->getType() << Parm;
3338         S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3339         if (Target)
3340           S.Diag(Target->getLocStart(), diag::note_declared_at);
3341         return true;
3342       }
3343       return false;
3344     }
3345     T = TDNDecl->getUnderlyingType();
3346   }
3347   return true;
3348 }
3349 
3350 template <typename TB>
CheckObjCBridgeCFCast(Sema & S,QualType castType,Expr * castExpr,bool & HadTheAttribute,bool warn)3351 static bool CheckObjCBridgeCFCast(Sema &S, QualType castType, Expr *castExpr,
3352                                   bool &HadTheAttribute, bool warn) {
3353   QualType T = castType;
3354   HadTheAttribute = false;
3355   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3356     TypedefNameDecl *TDNDecl = TD->getDecl();
3357     if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
3358       if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
3359         HadTheAttribute = true;
3360         NamedDecl *Target = nullptr;
3361         // Check for an existing type with this name.
3362         LookupResult R(S, DeclarationName(Parm), SourceLocation(),
3363                        Sema::LookupOrdinaryName);
3364         if (S.LookupName(R, S.TUScope)) {
3365           Target = R.getFoundDecl();
3366           if (Target && isa<ObjCInterfaceDecl>(Target)) {
3367             ObjCInterfaceDecl *CastClass = cast<ObjCInterfaceDecl>(Target);
3368             if (const ObjCObjectPointerType *InterfacePointerType =
3369                   castExpr->getType()->getAsObjCInterfacePointerType()) {
3370               ObjCInterfaceDecl *ExprClass
3371                 = InterfacePointerType->getObjectType()->getInterface();
3372               if ((CastClass == ExprClass) ||
3373                   (ExprClass && CastClass->isSuperClassOf(ExprClass)))
3374                 return true;
3375               if (warn) {
3376                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge_to_cf)
3377                   << castExpr->getType()->getPointeeType() << T;
3378                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3379               }
3380               return false;
3381             } else if (castExpr->getType()->isObjCIdType() ||
3382                        (S.Context.QIdProtocolsAdoptObjCObjectProtocols(
3383                           castExpr->getType(), CastClass)))
3384               // ok to cast an 'id' expression to a CFtype.
3385               // ok to cast an 'id<plist>' expression to CFtype provided plist
3386               // adopts all of CFtype's ObjetiveC's class plist.
3387               return true;
3388             else {
3389               if (warn) {
3390                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge_to_cf)
3391                   << castExpr->getType() << castType;
3392                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3393                 S.Diag(Target->getLocStart(), diag::note_declared_at);
3394               }
3395               return false;
3396             }
3397           }
3398         }
3399         S.Diag(castExpr->getLocStart(), diag::err_objc_ns_bridged_invalid_cfobject)
3400         << castExpr->getType() << castType;
3401         S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3402         if (Target)
3403           S.Diag(Target->getLocStart(), diag::note_declared_at);
3404         return true;
3405       }
3406       return false;
3407     }
3408     T = TDNDecl->getUnderlyingType();
3409   }
3410   return true;
3411 }
3412 
CheckTollFreeBridgeCast(QualType castType,Expr * castExpr)3413 void Sema::CheckTollFreeBridgeCast(QualType castType, Expr *castExpr) {
3414   if (!getLangOpts().ObjC1)
3415     return;
3416   // warn in presence of __bridge casting to or from a toll free bridge cast.
3417   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExpr->getType());
3418   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
3419   if (castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) {
3420     bool HasObjCBridgeAttr;
3421     bool ObjCBridgeAttrWillNotWarn =
3422       CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3423                                             false);
3424     if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
3425       return;
3426     bool HasObjCBridgeMutableAttr;
3427     bool ObjCBridgeMutableAttrWillNotWarn =
3428       CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3429                                                    HasObjCBridgeMutableAttr, false);
3430     if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
3431       return;
3432 
3433     if (HasObjCBridgeAttr)
3434       CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3435                                             true);
3436     else if (HasObjCBridgeMutableAttr)
3437       CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3438                                                    HasObjCBridgeMutableAttr, true);
3439   }
3440   else if (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable) {
3441     bool HasObjCBridgeAttr;
3442     bool ObjCBridgeAttrWillNotWarn =
3443       CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3444                                             false);
3445     if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
3446       return;
3447     bool HasObjCBridgeMutableAttr;
3448     bool ObjCBridgeMutableAttrWillNotWarn =
3449       CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3450                                                    HasObjCBridgeMutableAttr, false);
3451     if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
3452       return;
3453 
3454     if (HasObjCBridgeAttr)
3455       CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3456                                             true);
3457     else if (HasObjCBridgeMutableAttr)
3458       CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3459                                                    HasObjCBridgeMutableAttr, true);
3460   }
3461 }
3462 
CheckObjCBridgeRelatedCast(QualType castType,Expr * castExpr)3463 void Sema::CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr) {
3464   QualType SrcType = castExpr->getType();
3465   if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(castExpr)) {
3466     if (PRE->isExplicitProperty()) {
3467       if (ObjCPropertyDecl *PDecl = PRE->getExplicitProperty())
3468         SrcType = PDecl->getType();
3469     }
3470     else if (PRE->isImplicitProperty()) {
3471       if (ObjCMethodDecl *Getter = PRE->getImplicitPropertyGetter())
3472         SrcType = Getter->getReturnType();
3473 
3474     }
3475   }
3476 
3477   ARCConversionTypeClass srcExprACTC = classifyTypeForARCConversion(SrcType);
3478   ARCConversionTypeClass castExprACTC = classifyTypeForARCConversion(castType);
3479   if (srcExprACTC != ACTC_retainable || castExprACTC != ACTC_coreFoundation)
3480     return;
3481   CheckObjCBridgeRelatedConversions(castExpr->getLocStart(),
3482                                     castType, SrcType, castExpr);
3483   return;
3484 }
3485 
CheckTollFreeBridgeStaticCast(QualType castType,Expr * castExpr,CastKind & Kind)3486 bool Sema::CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
3487                                          CastKind &Kind) {
3488   if (!getLangOpts().ObjC1)
3489     return false;
3490   ARCConversionTypeClass exprACTC =
3491     classifyTypeForARCConversion(castExpr->getType());
3492   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
3493   if ((castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) ||
3494       (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable)) {
3495     CheckTollFreeBridgeCast(castType, castExpr);
3496     Kind = (castACTC == ACTC_coreFoundation) ? CK_BitCast
3497                                              : CK_CPointerToObjCPointerCast;
3498     return true;
3499   }
3500   return false;
3501 }
3502 
checkObjCBridgeRelatedComponents(SourceLocation Loc,QualType DestType,QualType SrcType,ObjCInterfaceDecl * & RelatedClass,ObjCMethodDecl * & ClassMethod,ObjCMethodDecl * & InstanceMethod,TypedefNameDecl * & TDNDecl,bool CfToNs)3503 bool Sema::checkObjCBridgeRelatedComponents(SourceLocation Loc,
3504                                             QualType DestType, QualType SrcType,
3505                                             ObjCInterfaceDecl *&RelatedClass,
3506                                             ObjCMethodDecl *&ClassMethod,
3507                                             ObjCMethodDecl *&InstanceMethod,
3508                                             TypedefNameDecl *&TDNDecl,
3509                                             bool CfToNs) {
3510   QualType T = CfToNs ? SrcType : DestType;
3511   ObjCBridgeRelatedAttr *ObjCBAttr = ObjCBridgeRelatedAttrFromType(T, TDNDecl);
3512   if (!ObjCBAttr)
3513     return false;
3514 
3515   IdentifierInfo *RCId = ObjCBAttr->getRelatedClass();
3516   IdentifierInfo *CMId = ObjCBAttr->getClassMethod();
3517   IdentifierInfo *IMId = ObjCBAttr->getInstanceMethod();
3518   if (!RCId)
3519     return false;
3520   NamedDecl *Target = nullptr;
3521   // Check for an existing type with this name.
3522   LookupResult R(*this, DeclarationName(RCId), SourceLocation(),
3523                  Sema::LookupOrdinaryName);
3524   if (!LookupName(R, TUScope)) {
3525     Diag(Loc, diag::err_objc_bridged_related_invalid_class) << RCId
3526           << SrcType << DestType;
3527     Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3528     return false;
3529   }
3530   Target = R.getFoundDecl();
3531   if (Target && isa<ObjCInterfaceDecl>(Target))
3532     RelatedClass = cast<ObjCInterfaceDecl>(Target);
3533   else {
3534     Diag(Loc, diag::err_objc_bridged_related_invalid_class_name) << RCId
3535           << SrcType << DestType;
3536     Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3537     if (Target)
3538       Diag(Target->getLocStart(), diag::note_declared_at);
3539     return false;
3540   }
3541 
3542   // Check for an existing class method with the given selector name.
3543   if (CfToNs && CMId) {
3544     Selector Sel = Context.Selectors.getUnarySelector(CMId);
3545     ClassMethod = RelatedClass->lookupMethod(Sel, false);
3546     if (!ClassMethod) {
3547       Diag(Loc, diag::err_objc_bridged_related_known_method)
3548             << SrcType << DestType << Sel << false;
3549       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3550       return false;
3551     }
3552   }
3553 
3554   // Check for an existing instance method with the given selector name.
3555   if (!CfToNs && IMId) {
3556     Selector Sel = Context.Selectors.getNullarySelector(IMId);
3557     InstanceMethod = RelatedClass->lookupMethod(Sel, true);
3558     if (!InstanceMethod) {
3559       Diag(Loc, diag::err_objc_bridged_related_known_method)
3560             << SrcType << DestType << Sel << true;
3561       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3562       return false;
3563     }
3564   }
3565   return true;
3566 }
3567 
3568 bool
CheckObjCBridgeRelatedConversions(SourceLocation Loc,QualType DestType,QualType SrcType,Expr * & SrcExpr)3569 Sema::CheckObjCBridgeRelatedConversions(SourceLocation Loc,
3570                                         QualType DestType, QualType SrcType,
3571                                         Expr *&SrcExpr) {
3572   ARCConversionTypeClass rhsExprACTC = classifyTypeForARCConversion(SrcType);
3573   ARCConversionTypeClass lhsExprACTC = classifyTypeForARCConversion(DestType);
3574   bool CfToNs = (rhsExprACTC == ACTC_coreFoundation && lhsExprACTC == ACTC_retainable);
3575   bool NsToCf = (rhsExprACTC == ACTC_retainable && lhsExprACTC == ACTC_coreFoundation);
3576   if (!CfToNs && !NsToCf)
3577     return false;
3578 
3579   ObjCInterfaceDecl *RelatedClass;
3580   ObjCMethodDecl *ClassMethod = nullptr;
3581   ObjCMethodDecl *InstanceMethod = nullptr;
3582   TypedefNameDecl *TDNDecl = nullptr;
3583   if (!checkObjCBridgeRelatedComponents(Loc, DestType, SrcType, RelatedClass,
3584                                         ClassMethod, InstanceMethod, TDNDecl, CfToNs))
3585     return false;
3586 
3587   if (CfToNs) {
3588     // Implicit conversion from CF to ObjC object is needed.
3589     if (ClassMethod) {
3590       std::string ExpressionString = "[";
3591       ExpressionString += RelatedClass->getNameAsString();
3592       ExpressionString += " ";
3593       ExpressionString += ClassMethod->getSelector().getAsString();
3594       SourceLocation SrcExprEndLoc = PP.getLocForEndOfToken(SrcExpr->getLocEnd());
3595       // Provide a fixit: [RelatedClass ClassMethod SrcExpr]
3596       Diag(Loc, diag::err_objc_bridged_related_known_method)
3597         << SrcType << DestType << ClassMethod->getSelector() << false
3598         << FixItHint::CreateInsertion(SrcExpr->getLocStart(), ExpressionString)
3599         << FixItHint::CreateInsertion(SrcExprEndLoc, "]");
3600       Diag(RelatedClass->getLocStart(), diag::note_declared_at);
3601       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3602 
3603       QualType receiverType =
3604         Context.getObjCInterfaceType(RelatedClass);
3605       // Argument.
3606       Expr *args[] = { SrcExpr };
3607       ExprResult msg = BuildClassMessageImplicit(receiverType, false,
3608                                       ClassMethod->getLocation(),
3609                                       ClassMethod->getSelector(), ClassMethod,
3610                                       MultiExprArg(args, 1));
3611       SrcExpr = msg.get();
3612       return true;
3613     }
3614   }
3615   else {
3616     // Implicit conversion from ObjC type to CF object is needed.
3617     if (InstanceMethod) {
3618       std::string ExpressionString;
3619       SourceLocation SrcExprEndLoc = PP.getLocForEndOfToken(SrcExpr->getLocEnd());
3620       if (InstanceMethod->isPropertyAccessor())
3621         if (const ObjCPropertyDecl *PDecl = InstanceMethod->findPropertyDecl()) {
3622           // fixit: ObjectExpr.propertyname when it is  aproperty accessor.
3623           ExpressionString = ".";
3624           ExpressionString += PDecl->getNameAsString();
3625           Diag(Loc, diag::err_objc_bridged_related_known_method)
3626           << SrcType << DestType << InstanceMethod->getSelector() << true
3627           << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
3628         }
3629       if (ExpressionString.empty()) {
3630         // Provide a fixit: [ObjectExpr InstanceMethod]
3631         ExpressionString = " ";
3632         ExpressionString += InstanceMethod->getSelector().getAsString();
3633         ExpressionString += "]";
3634 
3635         Diag(Loc, diag::err_objc_bridged_related_known_method)
3636         << SrcType << DestType << InstanceMethod->getSelector() << true
3637         << FixItHint::CreateInsertion(SrcExpr->getLocStart(), "[")
3638         << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
3639       }
3640       Diag(RelatedClass->getLocStart(), diag::note_declared_at);
3641       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3642 
3643       ExprResult msg =
3644         BuildInstanceMessageImplicit(SrcExpr, SrcType,
3645                                      InstanceMethod->getLocation(),
3646                                      InstanceMethod->getSelector(),
3647                                      InstanceMethod, None);
3648       SrcExpr = msg.get();
3649       return true;
3650     }
3651   }
3652   return false;
3653 }
3654 
3655 Sema::ARCConversionResult
CheckObjCARCConversion(SourceRange castRange,QualType castType,Expr * & castExpr,CheckedConversionKind CCK,bool DiagnoseCFAudited,BinaryOperatorKind Opc)3656 Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
3657                              Expr *&castExpr, CheckedConversionKind CCK,
3658                              bool DiagnoseCFAudited,
3659                              BinaryOperatorKind Opc) {
3660   QualType castExprType = castExpr->getType();
3661 
3662   // For the purposes of the classification, we assume reference types
3663   // will bind to temporaries.
3664   QualType effCastType = castType;
3665   if (const ReferenceType *ref = castType->getAs<ReferenceType>())
3666     effCastType = ref->getPointeeType();
3667 
3668   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
3669   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
3670   if (exprACTC == castACTC) {
3671     // check for viablity and report error if casting an rvalue to a
3672     // life-time qualifier.
3673     if ((castACTC == ACTC_retainable) &&
3674         (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
3675         (castType != castExprType)) {
3676       const Type *DT = castType.getTypePtr();
3677       QualType QDT = castType;
3678       // We desugar some types but not others. We ignore those
3679       // that cannot happen in a cast; i.e. auto, and those which
3680       // should not be de-sugared; i.e typedef.
3681       if (const ParenType *PT = dyn_cast<ParenType>(DT))
3682         QDT = PT->desugar();
3683       else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
3684         QDT = TP->desugar();
3685       else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
3686         QDT = AT->desugar();
3687       if (QDT != castType &&
3688           QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
3689         SourceLocation loc =
3690           (castRange.isValid() ? castRange.getBegin()
3691                               : castExpr->getExprLoc());
3692         Diag(loc, diag::err_arc_nolifetime_behavior);
3693       }
3694     }
3695     return ACR_okay;
3696   }
3697 
3698   if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
3699 
3700   // Allow all of these types to be cast to integer types (but not
3701   // vice-versa).
3702   if (castACTC == ACTC_none && castType->isIntegralType(Context))
3703     return ACR_okay;
3704 
3705   // Allow casts between pointers to lifetime types (e.g., __strong id*)
3706   // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
3707   // must be explicit.
3708   if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
3709     return ACR_okay;
3710   if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
3711       CCK != CCK_ImplicitConversion)
3712     return ACR_okay;
3713 
3714   switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
3715   // For invalid casts, fall through.
3716   case ACC_invalid:
3717     break;
3718 
3719   // Do nothing for both bottom and +0.
3720   case ACC_bottom:
3721   case ACC_plusZero:
3722     return ACR_okay;
3723 
3724   // If the result is +1, consume it here.
3725   case ACC_plusOne:
3726     castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
3727                                         CK_ARCConsumeObject, castExpr,
3728                                         nullptr, VK_RValue);
3729     ExprNeedsCleanups = true;
3730     return ACR_okay;
3731   }
3732 
3733   // If this is a non-implicit cast from id or block type to a
3734   // CoreFoundation type, delay complaining in case the cast is used
3735   // in an acceptable context.
3736   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
3737       CCK != CCK_ImplicitConversion)
3738     return ACR_unbridged;
3739 
3740   // Do not issue bridge cast" diagnostic when implicit casting a cstring
3741   // to 'NSString *'. Let caller issue a normal mismatched diagnostic with
3742   // suitable fix-it.
3743   if (castACTC == ACTC_retainable && exprACTC == ACTC_none &&
3744       ConversionToObjCStringLiteralCheck(castType, castExpr))
3745     return ACR_okay;
3746 
3747   // Do not issue "bridge cast" diagnostic when implicit casting
3748   // a retainable object to a CF type parameter belonging to an audited
3749   // CF API function. Let caller issue a normal type mismatched diagnostic
3750   // instead.
3751   if (!DiagnoseCFAudited || exprACTC != ACTC_retainable ||
3752       castACTC != ACTC_coreFoundation)
3753     if (!(exprACTC == ACTC_voidPtr && castACTC == ACTC_retainable &&
3754           (Opc == BO_NE || Opc == BO_EQ)))
3755       diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3756                                 castExpr, castExpr, exprACTC, CCK);
3757   return ACR_okay;
3758 }
3759 
3760 /// Given that we saw an expression with the ARCUnbridgedCastTy
3761 /// placeholder type, complain bitterly.
diagnoseARCUnbridgedCast(Expr * e)3762 void Sema::diagnoseARCUnbridgedCast(Expr *e) {
3763   // We expect the spurious ImplicitCastExpr to already have been stripped.
3764   assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3765   CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
3766 
3767   SourceRange castRange;
3768   QualType castType;
3769   CheckedConversionKind CCK;
3770 
3771   if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
3772     castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
3773     castType = cast->getTypeAsWritten();
3774     CCK = CCK_CStyleCast;
3775   } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
3776     castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
3777     castType = cast->getTypeAsWritten();
3778     CCK = CCK_OtherCast;
3779   } else {
3780     castType = cast->getType();
3781     CCK = CCK_ImplicitConversion;
3782   }
3783 
3784   ARCConversionTypeClass castACTC =
3785     classifyTypeForARCConversion(castType.getNonReferenceType());
3786 
3787   Expr *castExpr = realCast->getSubExpr();
3788   assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
3789 
3790   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
3791                             castExpr, realCast, ACTC_retainable, CCK);
3792 }
3793 
3794 /// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
3795 /// type, remove the placeholder cast.
stripARCUnbridgedCast(Expr * e)3796 Expr *Sema::stripARCUnbridgedCast(Expr *e) {
3797   assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
3798 
3799   if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
3800     Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
3801     return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
3802   } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
3803     assert(uo->getOpcode() == UO_Extension);
3804     Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
3805     return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
3806                                    sub->getValueKind(), sub->getObjectKind(),
3807                                        uo->getOperatorLoc());
3808   } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
3809     assert(!gse->isResultDependent());
3810 
3811     unsigned n = gse->getNumAssocs();
3812     SmallVector<Expr*, 4> subExprs(n);
3813     SmallVector<TypeSourceInfo*, 4> subTypes(n);
3814     for (unsigned i = 0; i != n; ++i) {
3815       subTypes[i] = gse->getAssocTypeSourceInfo(i);
3816       Expr *sub = gse->getAssocExpr(i);
3817       if (i == gse->getResultIndex())
3818         sub = stripARCUnbridgedCast(sub);
3819       subExprs[i] = sub;
3820     }
3821 
3822     return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
3823                                               gse->getControllingExpr(),
3824                                               subTypes, subExprs,
3825                                               gse->getDefaultLoc(),
3826                                               gse->getRParenLoc(),
3827                                        gse->containsUnexpandedParameterPack(),
3828                                               gse->getResultIndex());
3829   } else {
3830     assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
3831     return cast<ImplicitCastExpr>(e)->getSubExpr();
3832   }
3833 }
3834 
CheckObjCARCUnavailableWeakConversion(QualType castType,QualType exprType)3835 bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
3836                                                  QualType exprType) {
3837   QualType canCastType =
3838     Context.getCanonicalType(castType).getUnqualifiedType();
3839   QualType canExprType =
3840     Context.getCanonicalType(exprType).getUnqualifiedType();
3841   if (isa<ObjCObjectPointerType>(canCastType) &&
3842       castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
3843       canExprType->isObjCObjectPointerType()) {
3844     if (const ObjCObjectPointerType *ObjT =
3845         canExprType->getAs<ObjCObjectPointerType>())
3846       if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
3847         return !ObjI->isArcWeakrefUnavailable();
3848   }
3849   return true;
3850 }
3851 
3852 /// Look for an ObjCReclaimReturnedObject cast and destroy it.
maybeUndoReclaimObject(Expr * e)3853 static Expr *maybeUndoReclaimObject(Expr *e) {
3854   // For now, we just undo operands that are *immediately* reclaim
3855   // expressions, which prevents the vast majority of potential
3856   // problems here.  To catch them all, we'd need to rebuild arbitrary
3857   // value-propagating subexpressions --- we can't reliably rebuild
3858   // in-place because of expression sharing.
3859   if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3860     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
3861       return ice->getSubExpr();
3862 
3863   return e;
3864 }
3865 
BuildObjCBridgedCast(SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,TypeSourceInfo * TSInfo,Expr * SubExpr)3866 ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
3867                                       ObjCBridgeCastKind Kind,
3868                                       SourceLocation BridgeKeywordLoc,
3869                                       TypeSourceInfo *TSInfo,
3870                                       Expr *SubExpr) {
3871   ExprResult SubResult = UsualUnaryConversions(SubExpr);
3872   if (SubResult.isInvalid()) return ExprError();
3873   SubExpr = SubResult.get();
3874 
3875   QualType T = TSInfo->getType();
3876   QualType FromType = SubExpr->getType();
3877 
3878   CastKind CK;
3879 
3880   bool MustConsume = false;
3881   if (T->isDependentType() || SubExpr->isTypeDependent()) {
3882     // Okay: we'll build a dependent expression type.
3883     CK = CK_Dependent;
3884   } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
3885     // Casting CF -> id
3886     CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
3887                                   : CK_CPointerToObjCPointerCast);
3888     switch (Kind) {
3889     case OBC_Bridge:
3890       break;
3891 
3892     case OBC_BridgeRetained: {
3893       bool br = isKnownName("CFBridgingRelease");
3894       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3895         << 2
3896         << FromType
3897         << (T->isBlockPointerType()? 1 : 0)
3898         << T
3899         << SubExpr->getSourceRange()
3900         << Kind;
3901       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3902         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
3903       Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
3904         << FromType << br
3905         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3906                                         br ? "CFBridgingRelease "
3907                                            : "__bridge_transfer ");
3908 
3909       Kind = OBC_Bridge;
3910       break;
3911     }
3912 
3913     case OBC_BridgeTransfer:
3914       // We must consume the Objective-C object produced by the cast.
3915       MustConsume = true;
3916       break;
3917     }
3918   } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
3919     // Okay: id -> CF
3920     CK = CK_BitCast;
3921     switch (Kind) {
3922     case OBC_Bridge:
3923       // Reclaiming a value that's going to be __bridge-casted to CF
3924       // is very dangerous, so we don't do it.
3925       SubExpr = maybeUndoReclaimObject(SubExpr);
3926       break;
3927 
3928     case OBC_BridgeRetained:
3929       // Produce the object before casting it.
3930       SubExpr = ImplicitCastExpr::Create(Context, FromType,
3931                                          CK_ARCProduceObject,
3932                                          SubExpr, nullptr, VK_RValue);
3933       break;
3934 
3935     case OBC_BridgeTransfer: {
3936       bool br = isKnownName("CFBridgingRetain");
3937       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
3938         << (FromType->isBlockPointerType()? 1 : 0)
3939         << FromType
3940         << 2
3941         << T
3942         << SubExpr->getSourceRange()
3943         << Kind;
3944 
3945       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
3946         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
3947       Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
3948         << T << br
3949         << FixItHint::CreateReplacement(BridgeKeywordLoc,
3950                           br ? "CFBridgingRetain " : "__bridge_retained");
3951 
3952       Kind = OBC_Bridge;
3953       break;
3954     }
3955     }
3956   } else {
3957     Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
3958       << FromType << T << Kind
3959       << SubExpr->getSourceRange()
3960       << TSInfo->getTypeLoc().getSourceRange();
3961     return ExprError();
3962   }
3963 
3964   Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
3965                                                    BridgeKeywordLoc,
3966                                                    TSInfo, SubExpr);
3967 
3968   if (MustConsume) {
3969     ExprNeedsCleanups = true;
3970     Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
3971                                       nullptr, VK_RValue);
3972   }
3973 
3974   return Result;
3975 }
3976 
ActOnObjCBridgedCast(Scope * S,SourceLocation LParenLoc,ObjCBridgeCastKind Kind,SourceLocation BridgeKeywordLoc,ParsedType Type,SourceLocation RParenLoc,Expr * SubExpr)3977 ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
3978                                       SourceLocation LParenLoc,
3979                                       ObjCBridgeCastKind Kind,
3980                                       SourceLocation BridgeKeywordLoc,
3981                                       ParsedType Type,
3982                                       SourceLocation RParenLoc,
3983                                       Expr *SubExpr) {
3984   TypeSourceInfo *TSInfo = nullptr;
3985   QualType T = GetTypeFromParser(Type, &TSInfo);
3986   if (Kind == OBC_Bridge)
3987     CheckTollFreeBridgeCast(T, SubExpr);
3988   if (!TSInfo)
3989     TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
3990   return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
3991                               SubExpr);
3992 }
3993