1 //===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
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 @property and
11 //  @synthesize declarations.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Sema/SemaInternal.h"
16 #include "clang/Sema/Initialization.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/ExprObjC.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ASTMutationListener.h"
21 #include "llvm/ADT/DenseSet.h"
22 #include "llvm/ADT/SmallString.h"
23 
24 using namespace clang;
25 
26 //===----------------------------------------------------------------------===//
27 // Grammar actions.
28 //===----------------------------------------------------------------------===//
29 
30 /// getImpliedARCOwnership - Given a set of property attributes and a
31 /// type, infer an expected lifetime.  The type's ownership qualification
32 /// is not considered.
33 ///
34 /// Returns OCL_None if the attributes as stated do not imply an ownership.
35 /// Never returns OCL_Autoreleasing.
36 static Qualifiers::ObjCLifetime getImpliedARCOwnership(
37                                ObjCPropertyDecl::PropertyAttributeKind attrs,
38                                                 QualType type) {
39   // retain, strong, copy, weak, and unsafe_unretained are only legal
40   // on properties of retainable pointer type.
41   if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
42                ObjCPropertyDecl::OBJC_PR_strong |
43                ObjCPropertyDecl::OBJC_PR_copy)) {
44     return type->getObjCARCImplicitLifetime();
45   } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
46     return Qualifiers::OCL_Weak;
47   } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
48     return Qualifiers::OCL_ExplicitNone;
49   }
50 
51   // assign can appear on other types, so we have to check the
52   // property type.
53   if (attrs & ObjCPropertyDecl::OBJC_PR_assign &&
54       type->isObjCRetainableType()) {
55     return Qualifiers::OCL_ExplicitNone;
56   }
57 
58   return Qualifiers::OCL_None;
59 }
60 
61 /// Check the internal consistency of a property declaration.
62 static void checkARCPropertyDecl(Sema &S, ObjCPropertyDecl *property) {
63   if (property->isInvalidDecl()) return;
64 
65   ObjCPropertyDecl::PropertyAttributeKind propertyKind
66     = property->getPropertyAttributes();
67   Qualifiers::ObjCLifetime propertyLifetime
68     = property->getType().getObjCLifetime();
69 
70   // Nothing to do if we don't have a lifetime.
71   if (propertyLifetime == Qualifiers::OCL_None) return;
72 
73   Qualifiers::ObjCLifetime expectedLifetime
74     = getImpliedARCOwnership(propertyKind, property->getType());
75   if (!expectedLifetime) {
76     // We have a lifetime qualifier but no dominating property
77     // attribute.  That's okay, but restore reasonable invariants by
78     // setting the property attribute according to the lifetime
79     // qualifier.
80     ObjCPropertyDecl::PropertyAttributeKind attr;
81     if (propertyLifetime == Qualifiers::OCL_Strong) {
82       attr = ObjCPropertyDecl::OBJC_PR_strong;
83     } else if (propertyLifetime == Qualifiers::OCL_Weak) {
84       attr = ObjCPropertyDecl::OBJC_PR_weak;
85     } else {
86       assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
87       attr = ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
88     }
89     property->setPropertyAttributes(attr);
90     return;
91   }
92 
93   if (propertyLifetime == expectedLifetime) return;
94 
95   property->setInvalidDecl();
96   S.Diag(property->getLocation(),
97          diag::err_arc_inconsistent_property_ownership)
98     << property->getDeclName()
99     << expectedLifetime
100     << propertyLifetime;
101 }
102 
103 Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
104                           FieldDeclarator &FD,
105                           ObjCDeclSpec &ODS,
106                           Selector GetterSel,
107                           Selector SetterSel,
108                           bool *isOverridingProperty,
109                           tok::ObjCKeywordKind MethodImplKind,
110                           DeclContext *lexicalDC) {
111   unsigned Attributes = ODS.getPropertyAttributes();
112   TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
113   QualType T = TSI->getType();
114   if ((getLangOptions().getGC() != LangOptions::NonGC &&
115        T.isObjCGCWeak()) ||
116       (getLangOptions().ObjCAutoRefCount &&
117        T.getObjCLifetime() == Qualifiers::OCL_Weak))
118     Attributes |= ObjCDeclSpec::DQ_PR_weak;
119 
120   bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
121                       // default is readwrite!
122                       !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
123   // property is defaulted to 'assign' if it is readwrite and is
124   // not retain or copy
125   bool isAssign = ((Attributes & ObjCDeclSpec::DQ_PR_assign) ||
126                    (isReadWrite &&
127                     !(Attributes & ObjCDeclSpec::DQ_PR_retain) &&
128                     !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
129                     !(Attributes & ObjCDeclSpec::DQ_PR_copy) &&
130                     !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
131                     !(Attributes & ObjCDeclSpec::DQ_PR_weak)));
132 
133   // Proceed with constructing the ObjCPropertDecls.
134   ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
135 
136   if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl))
137     if (CDecl->IsClassExtension()) {
138       Decl *Res = HandlePropertyInClassExtension(S, AtLoc,
139                                            FD, GetterSel, SetterSel,
140                                            isAssign, isReadWrite,
141                                            Attributes,
142                                            ODS.getPropertyAttributes(),
143                                            isOverridingProperty, TSI,
144                                            MethodImplKind);
145       if (Res) {
146         CheckObjCPropertyAttributes(Res, AtLoc, Attributes);
147         if (getLangOptions().ObjCAutoRefCount)
148           checkARCPropertyDecl(*this, cast<ObjCPropertyDecl>(Res));
149       }
150       return Res;
151     }
152 
153   ObjCPropertyDecl *Res = CreatePropertyDecl(S, ClassDecl, AtLoc, FD,
154                                              GetterSel, SetterSel,
155                                              isAssign, isReadWrite,
156                                              Attributes,
157                                              ODS.getPropertyAttributes(),
158                                              TSI, MethodImplKind);
159   if (lexicalDC)
160     Res->setLexicalDeclContext(lexicalDC);
161 
162   // Validate the attributes on the @property.
163   CheckObjCPropertyAttributes(Res, AtLoc, Attributes);
164 
165   if (getLangOptions().ObjCAutoRefCount)
166     checkARCPropertyDecl(*this, Res);
167 
168   return Res;
169 }
170 
171 static ObjCPropertyDecl::PropertyAttributeKind
172 makePropertyAttributesAsWritten(unsigned Attributes) {
173   unsigned attributesAsWritten = 0;
174   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
175     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
176   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
177     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
178   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
179     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
180   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
181     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
182   if (Attributes & ObjCDeclSpec::DQ_PR_assign)
183     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
184   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
185     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
186   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
187     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
188   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
189     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
190   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
191     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
192   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
193     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
194   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
195     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
196   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
197     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
198 
199   return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
200 }
201 
202 Decl *
203 Sema::HandlePropertyInClassExtension(Scope *S,
204                                      SourceLocation AtLoc, FieldDeclarator &FD,
205                                      Selector GetterSel, Selector SetterSel,
206                                      const bool isAssign,
207                                      const bool isReadWrite,
208                                      const unsigned Attributes,
209                                      const unsigned AttributesAsWritten,
210                                      bool *isOverridingProperty,
211                                      TypeSourceInfo *T,
212                                      tok::ObjCKeywordKind MethodImplKind) {
213   ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
214   // Diagnose if this property is already in continuation class.
215   DeclContext *DC = CurContext;
216   IdentifierInfo *PropertyId = FD.D.getIdentifier();
217   ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
218 
219   if (CCPrimary)
220     // Check for duplicate declaration of this property in current and
221     // other class extensions.
222     for (const ObjCCategoryDecl *ClsExtDecl =
223          CCPrimary->getFirstClassExtension();
224          ClsExtDecl; ClsExtDecl = ClsExtDecl->getNextClassExtension()) {
225       if (ObjCPropertyDecl *prevDecl =
226           ObjCPropertyDecl::findPropertyDecl(ClsExtDecl, PropertyId)) {
227         Diag(AtLoc, diag::err_duplicate_property);
228         Diag(prevDecl->getLocation(), diag::note_property_declare);
229         return 0;
230       }
231     }
232 
233   // Create a new ObjCPropertyDecl with the DeclContext being
234   // the class extension.
235   // FIXME. We should really be using CreatePropertyDecl for this.
236   ObjCPropertyDecl *PDecl =
237     ObjCPropertyDecl::Create(Context, DC, FD.D.getIdentifierLoc(),
238                              PropertyId, AtLoc, T);
239   PDecl->setPropertyAttributesAsWritten(
240                           makePropertyAttributesAsWritten(AttributesAsWritten));
241   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
242     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
243   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
244     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
245   // Set setter/getter selector name. Needed later.
246   PDecl->setGetterName(GetterSel);
247   PDecl->setSetterName(SetterSel);
248   ProcessDeclAttributes(S, PDecl, FD.D);
249   DC->addDecl(PDecl);
250 
251   // We need to look in the @interface to see if the @property was
252   // already declared.
253   if (!CCPrimary) {
254     Diag(CDecl->getLocation(), diag::err_continuation_class);
255     *isOverridingProperty = true;
256     return 0;
257   }
258 
259   // Find the property in continuation class's primary class only.
260   ObjCPropertyDecl *PIDecl =
261     CCPrimary->FindPropertyVisibleInPrimaryClass(PropertyId);
262 
263   if (!PIDecl) {
264     // No matching property found in the primary class. Just fall thru
265     // and add property to continuation class's primary class.
266     ObjCPropertyDecl *PDecl =
267       CreatePropertyDecl(S, CCPrimary, AtLoc,
268                          FD, GetterSel, SetterSel, isAssign, isReadWrite,
269                          Attributes,AttributesAsWritten, T, MethodImplKind, DC);
270 
271     // A case of continuation class adding a new property in the class. This
272     // is not what it was meant for. However, gcc supports it and so should we.
273     // Make sure setter/getters are declared here.
274     ProcessPropertyDecl(PDecl, CCPrimary, /* redeclaredProperty = */ 0,
275                         /* lexicalDC = */ CDecl);
276     if (ASTMutationListener *L = Context.getASTMutationListener())
277       L->AddedObjCPropertyInClassExtension(PDecl, /*OrigProp=*/0, CDecl);
278     return PDecl;
279   }
280   if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
281     bool IncompatibleObjC = false;
282     QualType ConvertedType;
283     // Relax the strict type matching for property type in continuation class.
284     // Allow property object type of continuation class to be different as long
285     // as it narrows the object type in its primary class property. Note that
286     // this conversion is safe only because the wider type is for a 'readonly'
287     // property in primary class and 'narrowed' type for a 'readwrite' property
288     // in continuation class.
289     if (!isa<ObjCObjectPointerType>(PIDecl->getType()) ||
290         !isa<ObjCObjectPointerType>(PDecl->getType()) ||
291         (!isObjCPointerConversion(PDecl->getType(), PIDecl->getType(),
292                                   ConvertedType, IncompatibleObjC))
293         || IncompatibleObjC) {
294       Diag(AtLoc,
295           diag::err_type_mismatch_continuation_class) << PDecl->getType();
296       Diag(PIDecl->getLocation(), diag::note_property_declare);
297     }
298   }
299 
300   // The property 'PIDecl's readonly attribute will be over-ridden
301   // with continuation class's readwrite property attribute!
302   unsigned PIkind = PIDecl->getPropertyAttributesAsWritten();
303   if (isReadWrite && (PIkind & ObjCPropertyDecl::OBJC_PR_readonly)) {
304     unsigned retainCopyNonatomic =
305     (ObjCPropertyDecl::OBJC_PR_retain |
306      ObjCPropertyDecl::OBJC_PR_strong |
307      ObjCPropertyDecl::OBJC_PR_copy |
308      ObjCPropertyDecl::OBJC_PR_nonatomic);
309     if ((Attributes & retainCopyNonatomic) !=
310         (PIkind & retainCopyNonatomic)) {
311       Diag(AtLoc, diag::warn_property_attr_mismatch);
312       Diag(PIDecl->getLocation(), diag::note_property_declare);
313     }
314     DeclContext *DC = cast<DeclContext>(CCPrimary);
315     if (!ObjCPropertyDecl::findPropertyDecl(DC,
316                                  PIDecl->getDeclName().getAsIdentifierInfo())) {
317       // Protocol is not in the primary class. Must build one for it.
318       ObjCDeclSpec ProtocolPropertyODS;
319       // FIXME. Assuming that ObjCDeclSpec::ObjCPropertyAttributeKind
320       // and ObjCPropertyDecl::PropertyAttributeKind have identical
321       // values.  Should consolidate both into one enum type.
322       ProtocolPropertyODS.
323       setPropertyAttributes((ObjCDeclSpec::ObjCPropertyAttributeKind)
324                             PIkind);
325       // Must re-establish the context from class extension to primary
326       // class context.
327       ContextRAII SavedContext(*this, CCPrimary);
328 
329       Decl *ProtocolPtrTy =
330         ActOnProperty(S, AtLoc, FD, ProtocolPropertyODS,
331                       PIDecl->getGetterName(),
332                       PIDecl->getSetterName(),
333                       isOverridingProperty,
334                       MethodImplKind,
335                       /* lexicalDC = */ CDecl);
336       PIDecl = cast<ObjCPropertyDecl>(ProtocolPtrTy);
337     }
338     PIDecl->makeitReadWriteAttribute();
339     if (Attributes & ObjCDeclSpec::DQ_PR_retain)
340       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
341     if (Attributes & ObjCDeclSpec::DQ_PR_strong)
342       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
343     if (Attributes & ObjCDeclSpec::DQ_PR_copy)
344       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
345     PIDecl->setSetterName(SetterSel);
346   } else {
347     // Tailor the diagnostics for the common case where a readwrite
348     // property is declared both in the @interface and the continuation.
349     // This is a common error where the user often intended the original
350     // declaration to be readonly.
351     unsigned diag =
352       (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
353       (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite)
354       ? diag::err_use_continuation_class_redeclaration_readwrite
355       : diag::err_use_continuation_class;
356     Diag(AtLoc, diag)
357       << CCPrimary->getDeclName();
358     Diag(PIDecl->getLocation(), diag::note_property_declare);
359   }
360   *isOverridingProperty = true;
361   // Make sure setter decl is synthesized, and added to primary class's list.
362   ProcessPropertyDecl(PIDecl, CCPrimary, PDecl, CDecl);
363   if (ASTMutationListener *L = Context.getASTMutationListener())
364     L->AddedObjCPropertyInClassExtension(PDecl, PIDecl, CDecl);
365   return 0;
366 }
367 
368 ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
369                                            ObjCContainerDecl *CDecl,
370                                            SourceLocation AtLoc,
371                                            FieldDeclarator &FD,
372                                            Selector GetterSel,
373                                            Selector SetterSel,
374                                            const bool isAssign,
375                                            const bool isReadWrite,
376                                            const unsigned Attributes,
377                                            const unsigned AttributesAsWritten,
378                                            TypeSourceInfo *TInfo,
379                                            tok::ObjCKeywordKind MethodImplKind,
380                                            DeclContext *lexicalDC){
381   IdentifierInfo *PropertyId = FD.D.getIdentifier();
382   QualType T = TInfo->getType();
383 
384   // Issue a warning if property is 'assign' as default and its object, which is
385   // gc'able conforms to NSCopying protocol
386   if (getLangOptions().getGC() != LangOptions::NonGC &&
387       isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign))
388     if (const ObjCObjectPointerType *ObjPtrTy =
389           T->getAs<ObjCObjectPointerType>()) {
390       ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
391       if (IDecl)
392         if (ObjCProtocolDecl* PNSCopying =
393             LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
394           if (IDecl->ClassImplementsProtocol(PNSCopying, true))
395             Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
396     }
397   if (T->isObjCObjectType())
398     Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object);
399 
400   DeclContext *DC = cast<DeclContext>(CDecl);
401   ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
402                                                      FD.D.getIdentifierLoc(),
403                                                      PropertyId, AtLoc, TInfo);
404 
405   if (ObjCPropertyDecl *prevDecl =
406         ObjCPropertyDecl::findPropertyDecl(DC, PropertyId)) {
407     Diag(PDecl->getLocation(), diag::err_duplicate_property);
408     Diag(prevDecl->getLocation(), diag::note_property_declare);
409     PDecl->setInvalidDecl();
410   }
411   else {
412     DC->addDecl(PDecl);
413     if (lexicalDC)
414       PDecl->setLexicalDeclContext(lexicalDC);
415   }
416 
417   if (T->isArrayType() || T->isFunctionType()) {
418     Diag(AtLoc, diag::err_property_type) << T;
419     PDecl->setInvalidDecl();
420   }
421 
422   ProcessDeclAttributes(S, PDecl, FD.D);
423 
424   // Regardless of setter/getter attribute, we save the default getter/setter
425   // selector names in anticipation of declaration of setter/getter methods.
426   PDecl->setGetterName(GetterSel);
427   PDecl->setSetterName(SetterSel);
428   PDecl->setPropertyAttributesAsWritten(
429                           makePropertyAttributesAsWritten(AttributesAsWritten));
430 
431   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
432     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
433 
434   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
435     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
436 
437   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
438     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
439 
440   if (isReadWrite)
441     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
442 
443   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
444     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
445 
446   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
447     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
448 
449   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
450     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
451 
452   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
453     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
454 
455   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
456     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
457 
458   if (isAssign)
459     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
460 
461   // In the semantic attributes, one of nonatomic or atomic is always set.
462   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
463     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
464   else
465     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
466 
467   // 'unsafe_unretained' is alias for 'assign'.
468   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
469     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
470   if (isAssign)
471     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
472 
473   if (MethodImplKind == tok::objc_required)
474     PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
475   else if (MethodImplKind == tok::objc_optional)
476     PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
477 
478   return PDecl;
479 }
480 
481 static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
482                                  ObjCPropertyDecl *property,
483                                  ObjCIvarDecl *ivar) {
484   if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
485 
486   QualType ivarType = ivar->getType();
487   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
488 
489   // The lifetime implied by the property's attributes.
490   Qualifiers::ObjCLifetime propertyLifetime =
491     getImpliedARCOwnership(property->getPropertyAttributes(),
492                            property->getType());
493 
494   // We're fine if they match.
495   if (propertyLifetime == ivarLifetime) return;
496 
497   // These aren't valid lifetimes for object ivars;  don't diagnose twice.
498   if (ivarLifetime == Qualifiers::OCL_None ||
499       ivarLifetime == Qualifiers::OCL_Autoreleasing)
500     return;
501 
502   switch (propertyLifetime) {
503   case Qualifiers::OCL_Strong:
504     S.Diag(propertyImplLoc, diag::err_arc_strong_property_ownership)
505       << property->getDeclName()
506       << ivar->getDeclName()
507       << ivarLifetime;
508     break;
509 
510   case Qualifiers::OCL_Weak:
511     S.Diag(propertyImplLoc, diag::error_weak_property)
512       << property->getDeclName()
513       << ivar->getDeclName();
514     break;
515 
516   case Qualifiers::OCL_ExplicitNone:
517     S.Diag(propertyImplLoc, diag::err_arc_assign_property_ownership)
518       << property->getDeclName()
519       << ivar->getDeclName()
520       << ((property->getPropertyAttributesAsWritten()
521            & ObjCPropertyDecl::OBJC_PR_assign) != 0);
522     break;
523 
524   case Qualifiers::OCL_Autoreleasing:
525     llvm_unreachable("properties cannot be autoreleasing");
526 
527   case Qualifiers::OCL_None:
528     // Any other property should be ignored.
529     return;
530   }
531 
532   S.Diag(property->getLocation(), diag::note_property_declare);
533 }
534 
535 /// setImpliedPropertyAttributeForReadOnlyProperty -
536 /// This routine evaludates life-time attributes for a 'readonly'
537 /// property with no known lifetime of its own, using backing
538 /// 'ivar's attribute, if any. If no backing 'ivar', property's
539 /// life-time is assumed 'strong'.
540 static void setImpliedPropertyAttributeForReadOnlyProperty(
541               ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
542   Qualifiers::ObjCLifetime propertyLifetime =
543     getImpliedARCOwnership(property->getPropertyAttributes(),
544                            property->getType());
545   if (propertyLifetime != Qualifiers::OCL_None)
546     return;
547 
548   if (!ivar) {
549     // if no backing ivar, make property 'strong'.
550     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
551     return;
552   }
553   // property assumes owenership of backing ivar.
554   QualType ivarType = ivar->getType();
555   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
556   if (ivarLifetime == Qualifiers::OCL_Strong)
557     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
558   else if (ivarLifetime == Qualifiers::OCL_Weak)
559     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
560   return;
561 }
562 
563 /// ActOnPropertyImplDecl - This routine performs semantic checks and
564 /// builds the AST node for a property implementation declaration; declared
565 /// as @synthesize or @dynamic.
566 ///
567 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
568                                   SourceLocation AtLoc,
569                                   SourceLocation PropertyLoc,
570                                   bool Synthesize,
571                                   IdentifierInfo *PropertyId,
572                                   IdentifierInfo *PropertyIvar,
573                                   SourceLocation PropertyIvarLoc) {
574   ObjCContainerDecl *ClassImpDecl =
575     dyn_cast<ObjCContainerDecl>(CurContext);
576   // Make sure we have a context for the property implementation declaration.
577   if (!ClassImpDecl) {
578     Diag(AtLoc, diag::error_missing_property_context);
579     return 0;
580   }
581   ObjCPropertyDecl *property = 0;
582   ObjCInterfaceDecl* IDecl = 0;
583   // Find the class or category class where this property must have
584   // a declaration.
585   ObjCImplementationDecl *IC = 0;
586   ObjCCategoryImplDecl* CatImplClass = 0;
587   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
588     IDecl = IC->getClassInterface();
589     // We always synthesize an interface for an implementation
590     // without an interface decl. So, IDecl is always non-zero.
591     assert(IDecl &&
592            "ActOnPropertyImplDecl - @implementation without @interface");
593 
594     // Look for this property declaration in the @implementation's @interface
595     property = IDecl->FindPropertyDeclaration(PropertyId);
596     if (!property) {
597       Diag(PropertyLoc, diag::error_bad_property_decl) << IDecl->getDeclName();
598       return 0;
599     }
600     unsigned PIkind = property->getPropertyAttributesAsWritten();
601     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
602                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
603       if (AtLoc.isValid())
604         Diag(AtLoc, diag::warn_implicit_atomic_property);
605       else
606         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
607       Diag(property->getLocation(), diag::note_property_declare);
608     }
609 
610     if (const ObjCCategoryDecl *CD =
611         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
612       if (!CD->IsClassExtension()) {
613         Diag(PropertyLoc, diag::error_category_property) << CD->getDeclName();
614         Diag(property->getLocation(), diag::note_property_declare);
615         return 0;
616       }
617     }
618   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
619     if (Synthesize) {
620       Diag(AtLoc, diag::error_synthesize_category_decl);
621       return 0;
622     }
623     IDecl = CatImplClass->getClassInterface();
624     if (!IDecl) {
625       Diag(AtLoc, diag::error_missing_property_interface);
626       return 0;
627     }
628     ObjCCategoryDecl *Category =
629     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
630 
631     // If category for this implementation not found, it is an error which
632     // has already been reported eralier.
633     if (!Category)
634       return 0;
635     // Look for this property declaration in @implementation's category
636     property = Category->FindPropertyDeclaration(PropertyId);
637     if (!property) {
638       Diag(PropertyLoc, diag::error_bad_category_property_decl)
639       << Category->getDeclName();
640       return 0;
641     }
642   } else {
643     Diag(AtLoc, diag::error_bad_property_context);
644     return 0;
645   }
646   ObjCIvarDecl *Ivar = 0;
647   // Check that we have a valid, previously declared ivar for @synthesize
648   if (Synthesize) {
649     // @synthesize
650     if (!PropertyIvar)
651       PropertyIvar = PropertyId;
652     // Check that this is a previously declared 'ivar' in 'IDecl' interface
653     ObjCInterfaceDecl *ClassDeclared;
654     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
655     QualType PropType = property->getType();
656     QualType PropertyIvarType = PropType.getNonReferenceType();
657 
658     if (getLangOptions().ObjCAutoRefCount &&
659         (property->getPropertyAttributesAsWritten() &
660          ObjCPropertyDecl::OBJC_PR_readonly) &&
661         PropertyIvarType->isObjCRetainableType()) {
662       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
663     }
664 
665     ObjCPropertyDecl::PropertyAttributeKind kind
666       = property->getPropertyAttributes();
667 
668     // Add GC __weak to the ivar type if the property is weak.
669     if ((kind & ObjCPropertyDecl::OBJC_PR_weak) &&
670         getLangOptions().getGC() != LangOptions::NonGC) {
671       assert(!getLangOptions().ObjCAutoRefCount);
672       if (PropertyIvarType.isObjCGCStrong()) {
673         Diag(PropertyLoc, diag::err_gc_weak_property_strong_type);
674         Diag(property->getLocation(), diag::note_property_declare);
675       } else {
676         PropertyIvarType =
677           Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
678       }
679     }
680 
681     if (!Ivar) {
682       // In ARC, give the ivar a lifetime qualifier based on the
683       // property attributes.
684       if (getLangOptions().ObjCAutoRefCount &&
685           !PropertyIvarType.getObjCLifetime() &&
686           PropertyIvarType->isObjCRetainableType()) {
687 
688         // It's an error if we have to do this and the user didn't
689         // explicitly write an ownership attribute on the property.
690         if (!property->hasWrittenStorageAttribute() &&
691             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
692           Diag(PropertyLoc,
693                diag::err_arc_objc_property_default_assign_on_object);
694           Diag(property->getLocation(), diag::note_property_declare);
695         } else {
696           Qualifiers::ObjCLifetime lifetime =
697             getImpliedARCOwnership(kind, PropertyIvarType);
698           assert(lifetime && "no lifetime for property?");
699           if (lifetime == Qualifiers::OCL_Weak) {
700             bool err = false;
701             if (const ObjCObjectPointerType *ObjT =
702                 PropertyIvarType->getAs<ObjCObjectPointerType>())
703               if (ObjT->getInterfaceDecl()->isArcWeakrefUnavailable()) {
704                 Diag(PropertyLoc, diag::err_arc_weak_unavailable_property);
705                 Diag(property->getLocation(), diag::note_property_declare);
706                 err = true;
707               }
708             if (!err && !getLangOptions().ObjCRuntimeHasWeak) {
709               Diag(PropertyLoc, diag::err_arc_weak_no_runtime);
710               Diag(property->getLocation(), diag::note_property_declare);
711             }
712           }
713 
714           Qualifiers qs;
715           qs.addObjCLifetime(lifetime);
716           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
717         }
718       }
719 
720       if (kind & ObjCPropertyDecl::OBJC_PR_weak &&
721           !getLangOptions().ObjCAutoRefCount &&
722           getLangOptions().getGC() == LangOptions::NonGC) {
723         Diag(PropertyLoc, diag::error_synthesize_weak_non_arc_or_gc);
724         Diag(property->getLocation(), diag::note_property_declare);
725       }
726 
727       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
728                                   PropertyLoc, PropertyLoc, PropertyIvar,
729                                   PropertyIvarType, /*Dinfo=*/0,
730                                   ObjCIvarDecl::Private,
731                                   (Expr *)0, true);
732       ClassImpDecl->addDecl(Ivar);
733       IDecl->makeDeclVisibleInContext(Ivar, false);
734       property->setPropertyIvarDecl(Ivar);
735 
736       if (!getLangOptions().ObjCNonFragileABI)
737         Diag(PropertyLoc, diag::error_missing_property_ivar_decl) << PropertyId;
738       // Note! I deliberately want it to fall thru so, we have a
739       // a property implementation and to avoid future warnings.
740     } else if (getLangOptions().ObjCNonFragileABI &&
741                !declaresSameEntity(ClassDeclared, IDecl)) {
742       Diag(PropertyLoc, diag::error_ivar_in_superclass_use)
743       << property->getDeclName() << Ivar->getDeclName()
744       << ClassDeclared->getDeclName();
745       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
746       << Ivar << Ivar->getName();
747       // Note! I deliberately want it to fall thru so more errors are caught.
748     }
749     QualType IvarType = Context.getCanonicalType(Ivar->getType());
750 
751     // Check that type of property and its ivar are type compatible.
752     if (Context.getCanonicalType(PropertyIvarType) != IvarType) {
753       bool compat = false;
754       if (isa<ObjCObjectPointerType>(PropertyIvarType)
755           && isa<ObjCObjectPointerType>(IvarType))
756         compat =
757           Context.canAssignObjCInterfaces(
758                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
759                                   IvarType->getAs<ObjCObjectPointerType>());
760       else {
761         SourceLocation Loc = PropertyIvarLoc;
762         if (Loc.isInvalid())
763           Loc = PropertyLoc;
764         compat = (CheckAssignmentConstraints(Loc, PropertyIvarType, IvarType)
765                     == Compatible);
766       }
767       if (!compat) {
768         Diag(PropertyLoc, diag::error_property_ivar_type)
769           << property->getDeclName() << PropType
770           << Ivar->getDeclName() << IvarType;
771         Diag(Ivar->getLocation(), diag::note_ivar_decl);
772         // Note! I deliberately want it to fall thru so, we have a
773         // a property implementation and to avoid future warnings.
774       }
775 
776       // FIXME! Rules for properties are somewhat different that those
777       // for assignments. Use a new routine to consolidate all cases;
778       // specifically for property redeclarations as well as for ivars.
779       QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
780       QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
781       if (lhsType != rhsType &&
782           lhsType->isArithmeticType()) {
783         Diag(PropertyLoc, diag::error_property_ivar_type)
784           << property->getDeclName() << PropType
785           << Ivar->getDeclName() << IvarType;
786         Diag(Ivar->getLocation(), diag::note_ivar_decl);
787         // Fall thru - see previous comment
788       }
789       // __weak is explicit. So it works on Canonical type.
790       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
791            getLangOptions().getGC() != LangOptions::NonGC)) {
792         Diag(PropertyLoc, diag::error_weak_property)
793         << property->getDeclName() << Ivar->getDeclName();
794         Diag(Ivar->getLocation(), diag::note_ivar_decl);
795         // Fall thru - see previous comment
796       }
797       // Fall thru - see previous comment
798       if ((property->getType()->isObjCObjectPointerType() ||
799            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
800           getLangOptions().getGC() != LangOptions::NonGC) {
801         Diag(PropertyLoc, diag::error_strong_property)
802         << property->getDeclName() << Ivar->getDeclName();
803         // Fall thru - see previous comment
804       }
805     }
806     if (getLangOptions().ObjCAutoRefCount)
807       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
808   } else if (PropertyIvar)
809     // @dynamic
810     Diag(PropertyLoc, diag::error_dynamic_property_ivar_decl);
811 
812   assert (property && "ActOnPropertyImplDecl - property declaration missing");
813   ObjCPropertyImplDecl *PIDecl =
814   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
815                                property,
816                                (Synthesize ?
817                                 ObjCPropertyImplDecl::Synthesize
818                                 : ObjCPropertyImplDecl::Dynamic),
819                                Ivar, PropertyIvarLoc);
820   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
821     getterMethod->createImplicitParams(Context, IDecl);
822     if (getLangOptions().CPlusPlus && Synthesize &&
823         Ivar->getType()->isRecordType()) {
824       // For Objective-C++, need to synthesize the AST for the IVAR object to be
825       // returned by the getter as it must conform to C++'s copy-return rules.
826       // FIXME. Eventually we want to do this for Objective-C as well.
827       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
828       DeclRefExpr *SelfExpr =
829         new (Context) DeclRefExpr(SelfDecl, SelfDecl->getType(),
830                                   VK_RValue, SourceLocation());
831       Expr *IvarRefExpr =
832         new (Context) ObjCIvarRefExpr(Ivar, Ivar->getType(), AtLoc,
833                                       SelfExpr, true, true);
834       ExprResult Res =
835         PerformCopyInitialization(InitializedEntity::InitializeResult(
836                                     SourceLocation(),
837                                     getterMethod->getResultType(),
838                                     /*NRVO=*/false),
839                                   SourceLocation(),
840                                   Owned(IvarRefExpr));
841       if (!Res.isInvalid()) {
842         Expr *ResExpr = Res.takeAs<Expr>();
843         if (ResExpr)
844           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
845         PIDecl->setGetterCXXConstructor(ResExpr);
846       }
847     }
848     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
849         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
850       Diag(getterMethod->getLocation(),
851            diag::warn_property_getter_owning_mismatch);
852       Diag(property->getLocation(), diag::note_property_declare);
853     }
854   }
855   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
856     setterMethod->createImplicitParams(Context, IDecl);
857     if (getLangOptions().CPlusPlus && Synthesize
858         && Ivar->getType()->isRecordType()) {
859       // FIXME. Eventually we want to do this for Objective-C as well.
860       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
861       DeclRefExpr *SelfExpr =
862         new (Context) DeclRefExpr(SelfDecl, SelfDecl->getType(),
863                                   VK_RValue, SourceLocation());
864       Expr *lhs =
865         new (Context) ObjCIvarRefExpr(Ivar, Ivar->getType(), AtLoc,
866                                       SelfExpr, true, true);
867       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
868       ParmVarDecl *Param = (*P);
869       QualType T = Param->getType().getNonReferenceType();
870       Expr *rhs = new (Context) DeclRefExpr(Param, T,
871                                             VK_LValue, SourceLocation());
872       ExprResult Res = BuildBinOp(S, lhs->getLocEnd(),
873                                   BO_Assign, lhs, rhs);
874       if (property->getPropertyAttributes() &
875           ObjCPropertyDecl::OBJC_PR_atomic) {
876         Expr *callExpr = Res.takeAs<Expr>();
877         if (const CXXOperatorCallExpr *CXXCE =
878               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
879           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
880             if (!FuncDecl->isTrivial())
881               if (property->getType()->isReferenceType()) {
882                 Diag(PropertyLoc,
883                      diag::err_atomic_property_nontrivial_assign_op)
884                     << property->getType();
885                 Diag(FuncDecl->getLocStart(),
886                      diag::note_callee_decl) << FuncDecl;
887               }
888       }
889       PIDecl->setSetterCXXAssignment(Res.takeAs<Expr>());
890     }
891   }
892 
893   if (IC) {
894     if (Synthesize)
895       if (ObjCPropertyImplDecl *PPIDecl =
896           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
897         Diag(PropertyLoc, diag::error_duplicate_ivar_use)
898         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
899         << PropertyIvar;
900         Diag(PPIDecl->getLocation(), diag::note_previous_use);
901       }
902 
903     if (ObjCPropertyImplDecl *PPIDecl
904         = IC->FindPropertyImplDecl(PropertyId)) {
905       Diag(PropertyLoc, diag::error_property_implemented) << PropertyId;
906       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
907       return 0;
908     }
909     IC->addPropertyImplementation(PIDecl);
910     if (getLangOptions().ObjCDefaultSynthProperties &&
911         getLangOptions().ObjCNonFragileABI2 &&
912         !IDecl->isObjCRequiresPropertyDefs()) {
913       // Diagnose if an ivar was lazily synthesdized due to a previous
914       // use and if 1) property is @dynamic or 2) property is synthesized
915       // but it requires an ivar of different name.
916       ObjCInterfaceDecl *ClassDeclared=0;
917       ObjCIvarDecl *Ivar = 0;
918       if (!Synthesize)
919         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
920       else {
921         if (PropertyIvar && PropertyIvar != PropertyId)
922           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
923       }
924       // Issue diagnostics only if Ivar belongs to current class.
925       if (Ivar && Ivar->getSynthesize() &&
926           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
927         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
928         << PropertyId;
929         Ivar->setInvalidDecl();
930       }
931     }
932   } else {
933     if (Synthesize)
934       if (ObjCPropertyImplDecl *PPIDecl =
935           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
936         Diag(PropertyLoc, diag::error_duplicate_ivar_use)
937         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
938         << PropertyIvar;
939         Diag(PPIDecl->getLocation(), diag::note_previous_use);
940       }
941 
942     if (ObjCPropertyImplDecl *PPIDecl =
943         CatImplClass->FindPropertyImplDecl(PropertyId)) {
944       Diag(PropertyLoc, diag::error_property_implemented) << PropertyId;
945       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
946       return 0;
947     }
948     CatImplClass->addPropertyImplementation(PIDecl);
949   }
950 
951   return PIDecl;
952 }
953 
954 //===----------------------------------------------------------------------===//
955 // Helper methods.
956 //===----------------------------------------------------------------------===//
957 
958 /// DiagnosePropertyMismatch - Compares two properties for their
959 /// attributes and types and warns on a variety of inconsistencies.
960 ///
961 void
962 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
963                                ObjCPropertyDecl *SuperProperty,
964                                const IdentifierInfo *inheritedName) {
965   ObjCPropertyDecl::PropertyAttributeKind CAttr =
966   Property->getPropertyAttributes();
967   ObjCPropertyDecl::PropertyAttributeKind SAttr =
968   SuperProperty->getPropertyAttributes();
969   if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
970       && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
971     Diag(Property->getLocation(), diag::warn_readonly_property)
972       << Property->getDeclName() << inheritedName;
973   if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
974       != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
975     Diag(Property->getLocation(), diag::warn_property_attribute)
976       << Property->getDeclName() << "copy" << inheritedName;
977   else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
978     unsigned CAttrRetain =
979       (CAttr &
980        (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
981     unsigned SAttrRetain =
982       (SAttr &
983        (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
984     bool CStrong = (CAttrRetain != 0);
985     bool SStrong = (SAttrRetain != 0);
986     if (CStrong != SStrong)
987       Diag(Property->getLocation(), diag::warn_property_attribute)
988         << Property->getDeclName() << "retain (or strong)" << inheritedName;
989   }
990 
991   if ((CAttr & ObjCPropertyDecl::OBJC_PR_nonatomic)
992       != (SAttr & ObjCPropertyDecl::OBJC_PR_nonatomic))
993     Diag(Property->getLocation(), diag::warn_property_attribute)
994       << Property->getDeclName() << "atomic" << inheritedName;
995   if (Property->getSetterName() != SuperProperty->getSetterName())
996     Diag(Property->getLocation(), diag::warn_property_attribute)
997       << Property->getDeclName() << "setter" << inheritedName;
998   if (Property->getGetterName() != SuperProperty->getGetterName())
999     Diag(Property->getLocation(), diag::warn_property_attribute)
1000       << Property->getDeclName() << "getter" << inheritedName;
1001 
1002   QualType LHSType =
1003     Context.getCanonicalType(SuperProperty->getType());
1004   QualType RHSType =
1005     Context.getCanonicalType(Property->getType());
1006 
1007   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1008     // Do cases not handled in above.
1009     // FIXME. For future support of covariant property types, revisit this.
1010     bool IncompatibleObjC = false;
1011     QualType ConvertedType;
1012     if (!isObjCPointerConversion(RHSType, LHSType,
1013                                  ConvertedType, IncompatibleObjC) ||
1014         IncompatibleObjC) {
1015         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1016         << Property->getType() << SuperProperty->getType() << inheritedName;
1017       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1018     }
1019   }
1020 }
1021 
1022 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1023                                             ObjCMethodDecl *GetterMethod,
1024                                             SourceLocation Loc) {
1025   if (GetterMethod &&
1026       !Context.hasSameType(GetterMethod->getResultType().getNonReferenceType(),
1027                            property->getType().getNonReferenceType())) {
1028     AssignConvertType result = Incompatible;
1029     if (property->getType()->isObjCObjectPointerType())
1030       result = CheckAssignmentConstraints(Loc, GetterMethod->getResultType(),
1031                                           property->getType());
1032     if (result != Compatible) {
1033       Diag(Loc, diag::warn_accessor_property_type_mismatch)
1034       << property->getDeclName()
1035       << GetterMethod->getSelector();
1036       Diag(GetterMethod->getLocation(), diag::note_declared_at);
1037       return true;
1038     }
1039   }
1040   return false;
1041 }
1042 
1043 /// ComparePropertiesInBaseAndSuper - This routine compares property
1044 /// declarations in base and its super class, if any, and issues
1045 /// diagnostics in a variety of inconsistent situations.
1046 ///
1047 void Sema::ComparePropertiesInBaseAndSuper(ObjCInterfaceDecl *IDecl) {
1048   ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1049   if (!SDecl)
1050     return;
1051   // FIXME: O(N^2)
1052   for (ObjCInterfaceDecl::prop_iterator S = SDecl->prop_begin(),
1053        E = SDecl->prop_end(); S != E; ++S) {
1054     ObjCPropertyDecl *SuperPDecl = (*S);
1055     // Does property in super class has declaration in current class?
1056     for (ObjCInterfaceDecl::prop_iterator I = IDecl->prop_begin(),
1057          E = IDecl->prop_end(); I != E; ++I) {
1058       ObjCPropertyDecl *PDecl = (*I);
1059       if (SuperPDecl->getIdentifier() == PDecl->getIdentifier())
1060           DiagnosePropertyMismatch(PDecl, SuperPDecl,
1061                                    SDecl->getIdentifier());
1062     }
1063   }
1064 }
1065 
1066 /// MatchOneProtocolPropertiesInClass - This routine goes thru the list
1067 /// of properties declared in a protocol and compares their attribute against
1068 /// the same property declared in the class or category.
1069 void
1070 Sema::MatchOneProtocolPropertiesInClass(Decl *CDecl,
1071                                           ObjCProtocolDecl *PDecl) {
1072   ObjCInterfaceDecl *IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDecl);
1073   if (!IDecl) {
1074     // Category
1075     ObjCCategoryDecl *CatDecl = static_cast<ObjCCategoryDecl*>(CDecl);
1076     assert (CatDecl && "MatchOneProtocolPropertiesInClass");
1077     if (!CatDecl->IsClassExtension())
1078       for (ObjCProtocolDecl::prop_iterator P = PDecl->prop_begin(),
1079            E = PDecl->prop_end(); P != E; ++P) {
1080         ObjCPropertyDecl *Pr = (*P);
1081         ObjCCategoryDecl::prop_iterator CP, CE;
1082         // Is this property already in  category's list of properties?
1083         for (CP = CatDecl->prop_begin(), CE = CatDecl->prop_end(); CP!=CE; ++CP)
1084           if ((*CP)->getIdentifier() == Pr->getIdentifier())
1085             break;
1086         if (CP != CE)
1087           // Property protocol already exist in class. Diagnose any mismatch.
1088           DiagnosePropertyMismatch((*CP), Pr, PDecl->getIdentifier());
1089       }
1090     return;
1091   }
1092   for (ObjCProtocolDecl::prop_iterator P = PDecl->prop_begin(),
1093        E = PDecl->prop_end(); P != E; ++P) {
1094     ObjCPropertyDecl *Pr = (*P);
1095     ObjCInterfaceDecl::prop_iterator CP, CE;
1096     // Is this property already in  class's list of properties?
1097     for (CP = IDecl->prop_begin(), CE = IDecl->prop_end(); CP != CE; ++CP)
1098       if ((*CP)->getIdentifier() == Pr->getIdentifier())
1099         break;
1100     if (CP != CE)
1101       // Property protocol already exist in class. Diagnose any mismatch.
1102       DiagnosePropertyMismatch((*CP), Pr, PDecl->getIdentifier());
1103     }
1104 }
1105 
1106 /// CompareProperties - This routine compares properties
1107 /// declared in 'ClassOrProtocol' objects (which can be a class or an
1108 /// inherited protocol with the list of properties for class/category 'CDecl'
1109 ///
1110 void Sema::CompareProperties(Decl *CDecl, Decl *ClassOrProtocol) {
1111   Decl *ClassDecl = ClassOrProtocol;
1112   ObjCInterfaceDecl *IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDecl);
1113 
1114   if (!IDecl) {
1115     // Category
1116     ObjCCategoryDecl *CatDecl = static_cast<ObjCCategoryDecl*>(CDecl);
1117     assert (CatDecl && "CompareProperties");
1118     if (ObjCCategoryDecl *MDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
1119       for (ObjCCategoryDecl::protocol_iterator P = MDecl->protocol_begin(),
1120            E = MDecl->protocol_end(); P != E; ++P)
1121       // Match properties of category with those of protocol (*P)
1122       MatchOneProtocolPropertiesInClass(CatDecl, *P);
1123 
1124       // Go thru the list of protocols for this category and recursively match
1125       // their properties with those in the category.
1126       for (ObjCCategoryDecl::protocol_iterator P = CatDecl->protocol_begin(),
1127            E = CatDecl->protocol_end(); P != E; ++P)
1128         CompareProperties(CatDecl, *P);
1129     } else {
1130       ObjCProtocolDecl *MD = cast<ObjCProtocolDecl>(ClassDecl);
1131       for (ObjCProtocolDecl::protocol_iterator P = MD->protocol_begin(),
1132            E = MD->protocol_end(); P != E; ++P)
1133         MatchOneProtocolPropertiesInClass(CatDecl, *P);
1134     }
1135     return;
1136   }
1137 
1138   if (ObjCInterfaceDecl *MDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
1139     for (ObjCInterfaceDecl::all_protocol_iterator
1140           P = MDecl->all_referenced_protocol_begin(),
1141           E = MDecl->all_referenced_protocol_end(); P != E; ++P)
1142       // Match properties of class IDecl with those of protocol (*P).
1143       MatchOneProtocolPropertiesInClass(IDecl, *P);
1144 
1145     // Go thru the list of protocols for this class and recursively match
1146     // their properties with those declared in the class.
1147     for (ObjCInterfaceDecl::all_protocol_iterator
1148           P = IDecl->all_referenced_protocol_begin(),
1149           E = IDecl->all_referenced_protocol_end(); P != E; ++P)
1150       CompareProperties(IDecl, *P);
1151   } else {
1152     ObjCProtocolDecl *MD = cast<ObjCProtocolDecl>(ClassDecl);
1153     for (ObjCProtocolDecl::protocol_iterator P = MD->protocol_begin(),
1154          E = MD->protocol_end(); P != E; ++P)
1155       MatchOneProtocolPropertiesInClass(IDecl, *P);
1156   }
1157 }
1158 
1159 /// isPropertyReadonly - Return true if property is readonly, by searching
1160 /// for the property in the class and in its categories and implementations
1161 ///
1162 bool Sema::isPropertyReadonly(ObjCPropertyDecl *PDecl,
1163                               ObjCInterfaceDecl *IDecl) {
1164   // by far the most common case.
1165   if (!PDecl->isReadOnly())
1166     return false;
1167   // Even if property is ready only, if interface has a user defined setter,
1168   // it is not considered read only.
1169   if (IDecl->getInstanceMethod(PDecl->getSetterName()))
1170     return false;
1171 
1172   // Main class has the property as 'readonly'. Must search
1173   // through the category list to see if the property's
1174   // attribute has been over-ridden to 'readwrite'.
1175   for (ObjCCategoryDecl *Category = IDecl->getCategoryList();
1176        Category; Category = Category->getNextClassCategory()) {
1177     // Even if property is ready only, if a category has a user defined setter,
1178     // it is not considered read only.
1179     if (Category->getInstanceMethod(PDecl->getSetterName()))
1180       return false;
1181     ObjCPropertyDecl *P =
1182       Category->FindPropertyDeclaration(PDecl->getIdentifier());
1183     if (P && !P->isReadOnly())
1184       return false;
1185   }
1186 
1187   // Also, check for definition of a setter method in the implementation if
1188   // all else failed.
1189   if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(CurContext)) {
1190     if (ObjCImplementationDecl *IMD =
1191         dyn_cast<ObjCImplementationDecl>(OMD->getDeclContext())) {
1192       if (IMD->getInstanceMethod(PDecl->getSetterName()))
1193         return false;
1194     } else if (ObjCCategoryImplDecl *CIMD =
1195                dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext())) {
1196       if (CIMD->getInstanceMethod(PDecl->getSetterName()))
1197         return false;
1198     }
1199   }
1200   // Lastly, look through the implementation (if one is in scope).
1201   if (ObjCImplementationDecl *ImpDecl = IDecl->getImplementation())
1202     if (ImpDecl->getInstanceMethod(PDecl->getSetterName()))
1203       return false;
1204   // If all fails, look at the super class.
1205   if (ObjCInterfaceDecl *SIDecl = IDecl->getSuperClass())
1206     return isPropertyReadonly(PDecl, SIDecl);
1207   return true;
1208 }
1209 
1210 /// CollectImmediateProperties - This routine collects all properties in
1211 /// the class and its conforming protocols; but not those it its super class.
1212 void Sema::CollectImmediateProperties(ObjCContainerDecl *CDecl,
1213             llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>& PropMap,
1214             llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>& SuperPropMap) {
1215   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1216     for (ObjCContainerDecl::prop_iterator P = IDecl->prop_begin(),
1217          E = IDecl->prop_end(); P != E; ++P) {
1218       ObjCPropertyDecl *Prop = (*P);
1219       PropMap[Prop->getIdentifier()] = Prop;
1220     }
1221     // scan through class's protocols.
1222     for (ObjCInterfaceDecl::all_protocol_iterator
1223          PI = IDecl->all_referenced_protocol_begin(),
1224          E = IDecl->all_referenced_protocol_end(); PI != E; ++PI)
1225         CollectImmediateProperties((*PI), PropMap, SuperPropMap);
1226   }
1227   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1228     if (!CATDecl->IsClassExtension())
1229       for (ObjCContainerDecl::prop_iterator P = CATDecl->prop_begin(),
1230            E = CATDecl->prop_end(); P != E; ++P) {
1231         ObjCPropertyDecl *Prop = (*P);
1232         PropMap[Prop->getIdentifier()] = Prop;
1233       }
1234     // scan through class's protocols.
1235     for (ObjCCategoryDecl::protocol_iterator PI = CATDecl->protocol_begin(),
1236          E = CATDecl->protocol_end(); PI != E; ++PI)
1237       CollectImmediateProperties((*PI), PropMap, SuperPropMap);
1238   }
1239   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1240     for (ObjCProtocolDecl::prop_iterator P = PDecl->prop_begin(),
1241          E = PDecl->prop_end(); P != E; ++P) {
1242       ObjCPropertyDecl *Prop = (*P);
1243       ObjCPropertyDecl *PropertyFromSuper = SuperPropMap[Prop->getIdentifier()];
1244       // Exclude property for protocols which conform to class's super-class,
1245       // as super-class has to implement the property.
1246       if (!PropertyFromSuper ||
1247           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1248         ObjCPropertyDecl *&PropEntry = PropMap[Prop->getIdentifier()];
1249         if (!PropEntry)
1250           PropEntry = Prop;
1251       }
1252     }
1253     // scan through protocol's protocols.
1254     for (ObjCProtocolDecl::protocol_iterator PI = PDecl->protocol_begin(),
1255          E = PDecl->protocol_end(); PI != E; ++PI)
1256       CollectImmediateProperties((*PI), PropMap, SuperPropMap);
1257   }
1258 }
1259 
1260 /// CollectClassPropertyImplementations - This routine collects list of
1261 /// properties to be implemented in the class. This includes, class's
1262 /// and its conforming protocols' properties.
1263 static void CollectClassPropertyImplementations(ObjCContainerDecl *CDecl,
1264                 llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>& PropMap) {
1265   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1266     for (ObjCContainerDecl::prop_iterator P = IDecl->prop_begin(),
1267          E = IDecl->prop_end(); P != E; ++P) {
1268       ObjCPropertyDecl *Prop = (*P);
1269       PropMap[Prop->getIdentifier()] = Prop;
1270     }
1271     for (ObjCInterfaceDecl::all_protocol_iterator
1272          PI = IDecl->all_referenced_protocol_begin(),
1273          E = IDecl->all_referenced_protocol_end(); PI != E; ++PI)
1274       CollectClassPropertyImplementations((*PI), PropMap);
1275   }
1276   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1277     for (ObjCProtocolDecl::prop_iterator P = PDecl->prop_begin(),
1278          E = PDecl->prop_end(); P != E; ++P) {
1279       ObjCPropertyDecl *Prop = (*P);
1280       PropMap[Prop->getIdentifier()] = Prop;
1281     }
1282     // scan through protocol's protocols.
1283     for (ObjCProtocolDecl::protocol_iterator PI = PDecl->protocol_begin(),
1284          E = PDecl->protocol_end(); PI != E; ++PI)
1285       CollectClassPropertyImplementations((*PI), PropMap);
1286   }
1287 }
1288 
1289 /// CollectSuperClassPropertyImplementations - This routine collects list of
1290 /// properties to be implemented in super class(s) and also coming from their
1291 /// conforming protocols.
1292 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1293                 llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>& PropMap) {
1294   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1295     while (SDecl) {
1296       CollectClassPropertyImplementations(SDecl, PropMap);
1297       SDecl = SDecl->getSuperClass();
1298     }
1299   }
1300 }
1301 
1302 /// LookupPropertyDecl - Looks up a property in the current class and all
1303 /// its protocols.
1304 ObjCPropertyDecl *Sema::LookupPropertyDecl(const ObjCContainerDecl *CDecl,
1305                                      IdentifierInfo *II) {
1306   if (const ObjCInterfaceDecl *IDecl =
1307         dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1308     for (ObjCContainerDecl::prop_iterator P = IDecl->prop_begin(),
1309          E = IDecl->prop_end(); P != E; ++P) {
1310       ObjCPropertyDecl *Prop = (*P);
1311       if (Prop->getIdentifier() == II)
1312         return Prop;
1313     }
1314     // scan through class's protocols.
1315     for (ObjCInterfaceDecl::all_protocol_iterator
1316          PI = IDecl->all_referenced_protocol_begin(),
1317          E = IDecl->all_referenced_protocol_end(); PI != E; ++PI) {
1318       ObjCPropertyDecl *Prop = LookupPropertyDecl((*PI), II);
1319       if (Prop)
1320         return Prop;
1321     }
1322   }
1323   else if (const ObjCProtocolDecl *PDecl =
1324             dyn_cast<ObjCProtocolDecl>(CDecl)) {
1325     for (ObjCProtocolDecl::prop_iterator P = PDecl->prop_begin(),
1326          E = PDecl->prop_end(); P != E; ++P) {
1327       ObjCPropertyDecl *Prop = (*P);
1328       if (Prop->getIdentifier() == II)
1329         return Prop;
1330     }
1331     // scan through protocol's protocols.
1332     for (ObjCProtocolDecl::protocol_iterator PI = PDecl->protocol_begin(),
1333          E = PDecl->protocol_end(); PI != E; ++PI) {
1334       ObjCPropertyDecl *Prop = LookupPropertyDecl((*PI), II);
1335       if (Prop)
1336         return Prop;
1337     }
1338   }
1339   return 0;
1340 }
1341 
1342 static IdentifierInfo * getDefaultSynthIvarName(ObjCPropertyDecl *Prop,
1343                                                 ASTContext &Ctx) {
1344   SmallString<128> ivarName;
1345   {
1346     llvm::raw_svector_ostream os(ivarName);
1347     os << '_' << Prop->getIdentifier()->getName();
1348   }
1349   return &Ctx.Idents.get(ivarName.str());
1350 }
1351 
1352 /// DefaultSynthesizeProperties - This routine default synthesizes all
1353 /// properties which must be synthesized in class's @implementation.
1354 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl* IMPDecl,
1355                                        ObjCInterfaceDecl *IDecl) {
1356 
1357   llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*> PropMap;
1358   CollectClassPropertyImplementations(IDecl, PropMap);
1359   if (PropMap.empty())
1360     return;
1361   llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*> SuperPropMap;
1362   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1363 
1364   for (llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>::iterator
1365        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
1366     ObjCPropertyDecl *Prop = P->second;
1367     // If property to be implemented in the super class, ignore.
1368     if (SuperPropMap[Prop->getIdentifier()])
1369       continue;
1370     // Is there a matching propery synthesize/dynamic?
1371     if (Prop->isInvalidDecl() ||
1372         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
1373         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier()))
1374       continue;
1375     // Property may have been synthesized by user.
1376     if (IMPDecl->FindPropertyImplDecl(Prop->getIdentifier()))
1377       continue;
1378     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1379       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1380         continue;
1381       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1382         continue;
1383     }
1384     if (isa<ObjCProtocolDecl>(Prop->getDeclContext())) {
1385       // We won't auto-synthesize properties declared in protocols.
1386       Diag(IMPDecl->getLocation(),
1387            diag::warn_auto_synthesizing_protocol_property);
1388       Diag(Prop->getLocation(), diag::note_property_declare);
1389       continue;
1390     }
1391 
1392     // We use invalid SourceLocations for the synthesized ivars since they
1393     // aren't really synthesized at a particular location; they just exist.
1394     // Saying that they are located at the @implementation isn't really going
1395     // to help users.
1396     ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1397                           true,
1398                           /* property = */ Prop->getIdentifier(),
1399                           /* ivar = */ getDefaultSynthIvarName(Prop, Context),
1400                           SourceLocation());
1401   }
1402 }
1403 
1404 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D) {
1405   if (!LangOpts.ObjCDefaultSynthProperties || !LangOpts.ObjCNonFragileABI2)
1406     return;
1407   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1408   if (!IC)
1409     return;
1410   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1411     if (!IDecl->isObjCRequiresPropertyDefs())
1412       DefaultSynthesizeProperties(S, IC, IDecl);
1413 }
1414 
1415 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1416                                       ObjCContainerDecl *CDecl,
1417                                       const llvm::DenseSet<Selector>& InsMap) {
1418   llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*> SuperPropMap;
1419   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl))
1420     CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1421 
1422   llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*> PropMap;
1423   CollectImmediateProperties(CDecl, PropMap, SuperPropMap);
1424   if (PropMap.empty())
1425     return;
1426 
1427   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
1428   for (ObjCImplDecl::propimpl_iterator
1429        I = IMPDecl->propimpl_begin(),
1430        EI = IMPDecl->propimpl_end(); I != EI; ++I)
1431     PropImplMap.insert((*I)->getPropertyDecl());
1432 
1433   for (llvm::DenseMap<IdentifierInfo *, ObjCPropertyDecl*>::iterator
1434        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
1435     ObjCPropertyDecl *Prop = P->second;
1436     // Is there a matching propery synthesize/dynamic?
1437     if (Prop->isInvalidDecl() ||
1438         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
1439         PropImplMap.count(Prop) || Prop->hasAttr<UnavailableAttr>())
1440       continue;
1441     if (!InsMap.count(Prop->getGetterName())) {
1442       Diag(IMPDecl->getLocation(),
1443            isa<ObjCCategoryDecl>(CDecl) ?
1444             diag::warn_setter_getter_impl_required_in_category :
1445             diag::warn_setter_getter_impl_required)
1446       << Prop->getDeclName() << Prop->getGetterName();
1447       Diag(Prop->getLocation(),
1448            diag::note_property_declare);
1449       if (LangOpts.ObjCDefaultSynthProperties && LangOpts.ObjCNonFragileABI2)
1450         if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1451           if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1452             Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1453 
1454     }
1455 
1456     if (!Prop->isReadOnly() && !InsMap.count(Prop->getSetterName())) {
1457       Diag(IMPDecl->getLocation(),
1458            isa<ObjCCategoryDecl>(CDecl) ?
1459            diag::warn_setter_getter_impl_required_in_category :
1460            diag::warn_setter_getter_impl_required)
1461       << Prop->getDeclName() << Prop->getSetterName();
1462       Diag(Prop->getLocation(),
1463            diag::note_property_declare);
1464       if (LangOpts.ObjCDefaultSynthProperties && LangOpts.ObjCNonFragileABI2)
1465         if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1466           if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1467             Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1468     }
1469   }
1470 }
1471 
1472 void
1473 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
1474                                        ObjCContainerDecl* IDecl) {
1475   // Rules apply in non-GC mode only
1476   if (getLangOptions().getGC() != LangOptions::NonGC)
1477     return;
1478   for (ObjCContainerDecl::prop_iterator I = IDecl->prop_begin(),
1479        E = IDecl->prop_end();
1480        I != E; ++I) {
1481     ObjCPropertyDecl *Property = (*I);
1482     ObjCMethodDecl *GetterMethod = 0;
1483     ObjCMethodDecl *SetterMethod = 0;
1484     bool LookedUpGetterSetter = false;
1485 
1486     unsigned Attributes = Property->getPropertyAttributes();
1487     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
1488 
1489     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
1490         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
1491       GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1492       SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1493       LookedUpGetterSetter = true;
1494       if (GetterMethod) {
1495         Diag(GetterMethod->getLocation(),
1496              diag::warn_default_atomic_custom_getter_setter)
1497           << Property->getIdentifier() << 0;
1498         Diag(Property->getLocation(), diag::note_property_declare);
1499       }
1500       if (SetterMethod) {
1501         Diag(SetterMethod->getLocation(),
1502              diag::warn_default_atomic_custom_getter_setter)
1503           << Property->getIdentifier() << 1;
1504         Diag(Property->getLocation(), diag::note_property_declare);
1505       }
1506     }
1507 
1508     // We only care about readwrite atomic property.
1509     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
1510         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
1511       continue;
1512     if (const ObjCPropertyImplDecl *PIDecl
1513          = IMPDecl->FindPropertyImplDecl(Property->getIdentifier())) {
1514       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
1515         continue;
1516       if (!LookedUpGetterSetter) {
1517         GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1518         SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1519         LookedUpGetterSetter = true;
1520       }
1521       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
1522         SourceLocation MethodLoc =
1523           (GetterMethod ? GetterMethod->getLocation()
1524                         : SetterMethod->getLocation());
1525         Diag(MethodLoc, diag::warn_atomic_property_rule)
1526           << Property->getIdentifier() << (GetterMethod != 0)
1527           << (SetterMethod != 0);
1528         Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
1529         Diag(Property->getLocation(), diag::note_property_declare);
1530       }
1531     }
1532   }
1533 }
1534 
1535 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
1536   if (getLangOptions().getGC() == LangOptions::GCOnly)
1537     return;
1538 
1539   for (ObjCImplementationDecl::propimpl_iterator
1540          i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) {
1541     ObjCPropertyImplDecl *PID = *i;
1542     if (PID->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
1543       continue;
1544 
1545     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
1546     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
1547         !D->getInstanceMethod(PD->getGetterName())) {
1548       ObjCMethodDecl *method = PD->getGetterMethodDecl();
1549       if (!method)
1550         continue;
1551       ObjCMethodFamily family = method->getMethodFamily();
1552       if (family == OMF_alloc || family == OMF_copy ||
1553           family == OMF_mutableCopy || family == OMF_new) {
1554         if (getLangOptions().ObjCAutoRefCount)
1555           Diag(PID->getLocation(), diag::err_ownin_getter_rule);
1556         else
1557           Diag(PID->getLocation(), diag::warn_owning_getter_rule);
1558         Diag(PD->getLocation(), diag::note_property_declare);
1559       }
1560     }
1561   }
1562 }
1563 
1564 /// AddPropertyAttrs - Propagates attributes from a property to the
1565 /// implicitly-declared getter or setter for that property.
1566 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
1567                              ObjCPropertyDecl *Property) {
1568   // Should we just clone all attributes over?
1569   for (Decl::attr_iterator A = Property->attr_begin(),
1570                         AEnd = Property->attr_end();
1571        A != AEnd; ++A) {
1572     if (isa<DeprecatedAttr>(*A) ||
1573         isa<UnavailableAttr>(*A) ||
1574         isa<AvailabilityAttr>(*A))
1575       PropertyMethod->addAttr((*A)->clone(S.Context));
1576   }
1577 }
1578 
1579 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
1580 /// have the property type and issue diagnostics if they don't.
1581 /// Also synthesize a getter/setter method if none exist (and update the
1582 /// appropriate lookup tables. FIXME: Should reconsider if adding synthesized
1583 /// methods is the "right" thing to do.
1584 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property,
1585                                ObjCContainerDecl *CD,
1586                                ObjCPropertyDecl *redeclaredProperty,
1587                                ObjCContainerDecl *lexicalDC) {
1588 
1589   ObjCMethodDecl *GetterMethod, *SetterMethod;
1590 
1591   GetterMethod = CD->getInstanceMethod(property->getGetterName());
1592   SetterMethod = CD->getInstanceMethod(property->getSetterName());
1593   DiagnosePropertyAccessorMismatch(property, GetterMethod,
1594                                    property->getLocation());
1595 
1596   if (SetterMethod) {
1597     ObjCPropertyDecl::PropertyAttributeKind CAttr =
1598       property->getPropertyAttributes();
1599     if ((!(CAttr & ObjCPropertyDecl::OBJC_PR_readonly)) &&
1600         Context.getCanonicalType(SetterMethod->getResultType()) !=
1601           Context.VoidTy)
1602       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
1603     if (SetterMethod->param_size() != 1 ||
1604         !Context.hasSameUnqualifiedType(
1605           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
1606           property->getType().getNonReferenceType())) {
1607       Diag(property->getLocation(),
1608            diag::warn_accessor_property_type_mismatch)
1609         << property->getDeclName()
1610         << SetterMethod->getSelector();
1611       Diag(SetterMethod->getLocation(), diag::note_declared_at);
1612     }
1613   }
1614 
1615   // Synthesize getter/setter methods if none exist.
1616   // Find the default getter and if one not found, add one.
1617   // FIXME: The synthesized property we set here is misleading. We almost always
1618   // synthesize these methods unless the user explicitly provided prototypes
1619   // (which is odd, but allowed). Sema should be typechecking that the
1620   // declarations jive in that situation (which it is not currently).
1621   if (!GetterMethod) {
1622     // No instance method of same name as property getter name was found.
1623     // Declare a getter method and add it to the list of methods
1624     // for this class.
1625     SourceLocation Loc = redeclaredProperty ?
1626       redeclaredProperty->getLocation() :
1627       property->getLocation();
1628 
1629     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
1630                              property->getGetterName(),
1631                              property->getType(), 0, CD, /*isInstance=*/true,
1632                              /*isVariadic=*/false, /*isSynthesized=*/true,
1633                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
1634                              (property->getPropertyImplementation() ==
1635                               ObjCPropertyDecl::Optional) ?
1636                              ObjCMethodDecl::Optional :
1637                              ObjCMethodDecl::Required);
1638     CD->addDecl(GetterMethod);
1639 
1640     AddPropertyAttrs(*this, GetterMethod, property);
1641 
1642     // FIXME: Eventually this shouldn't be needed, as the lexical context
1643     // and the real context should be the same.
1644     if (lexicalDC)
1645       GetterMethod->setLexicalDeclContext(lexicalDC);
1646     if (property->hasAttr<NSReturnsNotRetainedAttr>())
1647       GetterMethod->addAttr(
1648         ::new (Context) NSReturnsNotRetainedAttr(Loc, Context));
1649   } else
1650     // A user declared getter will be synthesize when @synthesize of
1651     // the property with the same name is seen in the @implementation
1652     GetterMethod->setSynthesized(true);
1653   property->setGetterMethodDecl(GetterMethod);
1654 
1655   // Skip setter if property is read-only.
1656   if (!property->isReadOnly()) {
1657     // Find the default setter and if one not found, add one.
1658     if (!SetterMethod) {
1659       // No instance method of same name as property setter name was found.
1660       // Declare a setter method and add it to the list of methods
1661       // for this class.
1662       SourceLocation Loc = redeclaredProperty ?
1663         redeclaredProperty->getLocation() :
1664         property->getLocation();
1665 
1666       SetterMethod =
1667         ObjCMethodDecl::Create(Context, Loc, Loc,
1668                                property->getSetterName(), Context.VoidTy, 0,
1669                                CD, /*isInstance=*/true, /*isVariadic=*/false,
1670                                /*isSynthesized=*/true,
1671                                /*isImplicitlyDeclared=*/true,
1672                                /*isDefined=*/false,
1673                                (property->getPropertyImplementation() ==
1674                                 ObjCPropertyDecl::Optional) ?
1675                                 ObjCMethodDecl::Optional :
1676                                 ObjCMethodDecl::Required);
1677 
1678       // Invent the arguments for the setter. We don't bother making a
1679       // nice name for the argument.
1680       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
1681                                                   Loc, Loc,
1682                                                   property->getIdentifier(),
1683                                     property->getType().getUnqualifiedType(),
1684                                                   /*TInfo=*/0,
1685                                                   SC_None,
1686                                                   SC_None,
1687                                                   0);
1688       SetterMethod->setMethodParams(Context, Argument,
1689                                     ArrayRef<SourceLocation>());
1690 
1691       AddPropertyAttrs(*this, SetterMethod, property);
1692 
1693       CD->addDecl(SetterMethod);
1694       // FIXME: Eventually this shouldn't be needed, as the lexical context
1695       // and the real context should be the same.
1696       if (lexicalDC)
1697         SetterMethod->setLexicalDeclContext(lexicalDC);
1698     } else
1699       // A user declared setter will be synthesize when @synthesize of
1700       // the property with the same name is seen in the @implementation
1701       SetterMethod->setSynthesized(true);
1702     property->setSetterMethodDecl(SetterMethod);
1703   }
1704   // Add any synthesized methods to the global pool. This allows us to
1705   // handle the following, which is supported by GCC (and part of the design).
1706   //
1707   // @interface Foo
1708   // @property double bar;
1709   // @end
1710   //
1711   // void thisIsUnfortunate() {
1712   //   id foo;
1713   //   double bar = [foo bar];
1714   // }
1715   //
1716   if (GetterMethod)
1717     AddInstanceMethodToGlobalPool(GetterMethod);
1718   if (SetterMethod)
1719     AddInstanceMethodToGlobalPool(SetterMethod);
1720 }
1721 
1722 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
1723                                        SourceLocation Loc,
1724                                        unsigned &Attributes) {
1725   // FIXME: Improve the reported location.
1726   if (!PDecl || PDecl->isInvalidDecl())
1727     return;
1728 
1729   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
1730   QualType PropertyTy = PropertyDecl->getType();
1731 
1732   if (getLangOptions().ObjCAutoRefCount &&
1733       (Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
1734       PropertyTy->isObjCRetainableType()) {
1735     // 'readonly' property with no obvious lifetime.
1736     // its life time will be determined by its backing ivar.
1737     unsigned rel = (ObjCDeclSpec::DQ_PR_unsafe_unretained |
1738                     ObjCDeclSpec::DQ_PR_copy |
1739                     ObjCDeclSpec::DQ_PR_retain |
1740                     ObjCDeclSpec::DQ_PR_strong |
1741                     ObjCDeclSpec::DQ_PR_weak |
1742                     ObjCDeclSpec::DQ_PR_assign);
1743     if ((Attributes & rel) == 0)
1744       return;
1745   }
1746 
1747   // readonly and readwrite/assign/retain/copy conflict.
1748   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
1749       (Attributes & (ObjCDeclSpec::DQ_PR_readwrite |
1750                      ObjCDeclSpec::DQ_PR_assign |
1751                      ObjCDeclSpec::DQ_PR_unsafe_unretained |
1752                      ObjCDeclSpec::DQ_PR_copy |
1753                      ObjCDeclSpec::DQ_PR_retain |
1754                      ObjCDeclSpec::DQ_PR_strong))) {
1755     const char * which = (Attributes & ObjCDeclSpec::DQ_PR_readwrite) ?
1756                           "readwrite" :
1757                          (Attributes & ObjCDeclSpec::DQ_PR_assign) ?
1758                           "assign" :
1759                          (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) ?
1760                           "unsafe_unretained" :
1761                          (Attributes & ObjCDeclSpec::DQ_PR_copy) ?
1762                           "copy" : "retain";
1763 
1764     Diag(Loc, (Attributes & (ObjCDeclSpec::DQ_PR_readwrite)) ?
1765                  diag::err_objc_property_attr_mutually_exclusive :
1766                  diag::warn_objc_property_attr_mutually_exclusive)
1767       << "readonly" << which;
1768   }
1769 
1770   // Check for copy or retain on non-object types.
1771   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
1772                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
1773       !PropertyTy->isObjCRetainableType() &&
1774       !PropertyDecl->getAttr<ObjCNSObjectAttr>()) {
1775     Diag(Loc, diag::err_objc_property_requires_object)
1776       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
1777           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
1778     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
1779                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
1780     PropertyDecl->setInvalidDecl();
1781   }
1782 
1783   // Check for more than one of { assign, copy, retain }.
1784   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
1785     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
1786       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1787         << "assign" << "copy";
1788       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
1789     }
1790     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
1791       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1792         << "assign" << "retain";
1793       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
1794     }
1795     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
1796       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1797         << "assign" << "strong";
1798       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
1799     }
1800     if (getLangOptions().ObjCAutoRefCount  &&
1801         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
1802       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1803         << "assign" << "weak";
1804       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
1805     }
1806   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
1807     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
1808       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1809         << "unsafe_unretained" << "copy";
1810       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
1811     }
1812     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
1813       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1814         << "unsafe_unretained" << "retain";
1815       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
1816     }
1817     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
1818       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1819         << "unsafe_unretained" << "strong";
1820       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
1821     }
1822     if (getLangOptions().ObjCAutoRefCount  &&
1823         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
1824       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1825         << "unsafe_unretained" << "weak";
1826       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
1827     }
1828   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
1829     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
1830       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1831         << "copy" << "retain";
1832       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
1833     }
1834     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
1835       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1836         << "copy" << "strong";
1837       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
1838     }
1839     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
1840       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1841         << "copy" << "weak";
1842       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
1843     }
1844   }
1845   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
1846            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
1847       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1848         << "retain" << "weak";
1849       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
1850   }
1851   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
1852            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
1853       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1854         << "strong" << "weak";
1855       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
1856   }
1857 
1858   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
1859       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
1860       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
1861         << "atomic" << "nonatomic";
1862       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
1863   }
1864 
1865   // Warn if user supplied no assignment attribute, property is
1866   // readwrite, and this is an object type.
1867   if (!(Attributes & (ObjCDeclSpec::DQ_PR_assign | ObjCDeclSpec::DQ_PR_copy |
1868                       ObjCDeclSpec::DQ_PR_unsafe_unretained |
1869                       ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong |
1870                       ObjCDeclSpec::DQ_PR_weak)) &&
1871       PropertyTy->isObjCObjectPointerType()) {
1872       if (getLangOptions().ObjCAutoRefCount)
1873         // With arc,  @property definitions should default to (strong) when
1874         // not specified; including when property is 'readonly'.
1875         PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
1876       else if (!(Attributes & ObjCDeclSpec::DQ_PR_readonly)) {
1877         bool isAnyClassTy =
1878           (PropertyTy->isObjCClassType() ||
1879            PropertyTy->isObjCQualifiedClassType());
1880         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
1881         // issue any warning.
1882         if (isAnyClassTy && getLangOptions().getGC() == LangOptions::NonGC)
1883           ;
1884         else {
1885           // Skip this warning in gc-only mode.
1886           if (getLangOptions().getGC() != LangOptions::GCOnly)
1887             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
1888 
1889           // If non-gc code warn that this is likely inappropriate.
1890           if (getLangOptions().getGC() == LangOptions::NonGC)
1891             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
1892         }
1893       }
1894 
1895     // FIXME: Implement warning dependent on NSCopying being
1896     // implemented. See also:
1897     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
1898     // (please trim this list while you are at it).
1899   }
1900 
1901   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
1902       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
1903       && getLangOptions().getGC() == LangOptions::GCOnly
1904       && PropertyTy->isBlockPointerType())
1905     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
1906   else if (getLangOptions().ObjCAutoRefCount &&
1907            (Attributes & ObjCDeclSpec::DQ_PR_retain) &&
1908            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
1909            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
1910            PropertyTy->isBlockPointerType())
1911       Diag(Loc, diag::warn_objc_property_retain_of_block);
1912 
1913   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
1914       (Attributes & ObjCDeclSpec::DQ_PR_setter))
1915     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
1916 
1917 }
1918