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