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/AST/ASTMutationListener.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/ExprObjC.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Lex/Lexer.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Sema/Initialization.h"
24 #include "llvm/ADT/DenseSet.h"
25 #include "llvm/ADT/SmallString.h"
26 
27 using namespace clang;
28 
29 //===----------------------------------------------------------------------===//
30 // Grammar actions.
31 //===----------------------------------------------------------------------===//
32 
33 /// getImpliedARCOwnership - Given a set of property attributes and a
34 /// type, infer an expected lifetime.  The type's ownership qualification
35 /// is not considered.
36 ///
37 /// Returns OCL_None if the attributes as stated do not imply an ownership.
38 /// Never returns OCL_Autoreleasing.
39 static Qualifiers::ObjCLifetime getImpliedARCOwnership(
40                                ObjCPropertyDecl::PropertyAttributeKind attrs,
41                                                 QualType type) {
42   // retain, strong, copy, weak, and unsafe_unretained are only legal
43   // on properties of retainable pointer type.
44   if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
45                ObjCPropertyDecl::OBJC_PR_strong |
46                ObjCPropertyDecl::OBJC_PR_copy)) {
47     return Qualifiers::OCL_Strong;
48   } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
49     return Qualifiers::OCL_Weak;
50   } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
51     return Qualifiers::OCL_ExplicitNone;
52   }
53 
54   // assign can appear on other types, so we have to check the
55   // property type.
56   if (attrs & ObjCPropertyDecl::OBJC_PR_assign &&
57       type->isObjCRetainableType()) {
58     return Qualifiers::OCL_ExplicitNone;
59   }
60 
61   return Qualifiers::OCL_None;
62 }
63 
64 /// Check the internal consistency of a property declaration with
65 /// an explicit ownership qualifier.
66 static void checkPropertyDeclWithOwnership(Sema &S,
67                                            ObjCPropertyDecl *property) {
68   if (property->isInvalidDecl()) return;
69 
70   ObjCPropertyDecl::PropertyAttributeKind propertyKind
71     = property->getPropertyAttributes();
72   Qualifiers::ObjCLifetime propertyLifetime
73     = property->getType().getObjCLifetime();
74 
75   assert(propertyLifetime != Qualifiers::OCL_None);
76 
77   Qualifiers::ObjCLifetime expectedLifetime
78     = getImpliedARCOwnership(propertyKind, property->getType());
79   if (!expectedLifetime) {
80     // We have a lifetime qualifier but no dominating property
81     // attribute.  That's okay, but restore reasonable invariants by
82     // setting the property attribute according to the lifetime
83     // qualifier.
84     ObjCPropertyDecl::PropertyAttributeKind attr;
85     if (propertyLifetime == Qualifiers::OCL_Strong) {
86       attr = ObjCPropertyDecl::OBJC_PR_strong;
87     } else if (propertyLifetime == Qualifiers::OCL_Weak) {
88       attr = ObjCPropertyDecl::OBJC_PR_weak;
89     } else {
90       assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
91       attr = ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
92     }
93     property->setPropertyAttributes(attr);
94     return;
95   }
96 
97   if (propertyLifetime == expectedLifetime) return;
98 
99   property->setInvalidDecl();
100   S.Diag(property->getLocation(),
101          diag::err_arc_inconsistent_property_ownership)
102     << property->getDeclName()
103     << expectedLifetime
104     << propertyLifetime;
105 }
106 
107 /// \brief Check this Objective-C property against a property declared in the
108 /// given protocol.
109 static void
110 CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
111                              ObjCProtocolDecl *Proto,
112                              llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
113   // Have we seen this protocol before?
114   if (!Known.insert(Proto).second)
115     return;
116 
117   // Look for a property with the same name.
118   DeclContext::lookup_result R = Proto->lookup(Prop->getDeclName());
119   for (unsigned I = 0, N = R.size(); I != N; ++I) {
120     if (ObjCPropertyDecl *ProtoProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
121       S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
122       return;
123     }
124   }
125 
126   // Check this property against any protocols we inherit.
127   for (auto *P : Proto->protocols())
128     CheckPropertyAgainstProtocol(S, Prop, P, Known);
129 }
130 
131 static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
132   // In GC mode, just look for the __weak qualifier.
133   if (S.getLangOpts().getGC() != LangOptions::NonGC) {
134     if (T.isObjCGCWeak()) return ObjCDeclSpec::DQ_PR_weak;
135 
136   // In ARC/MRC, look for an explicit ownership qualifier.
137   // For some reason, this only applies to __weak.
138   } else if (auto ownership = T.getObjCLifetime()) {
139     switch (ownership) {
140     case Qualifiers::OCL_Weak:
141       return ObjCDeclSpec::DQ_PR_weak;
142     case Qualifiers::OCL_Strong:
143       return ObjCDeclSpec::DQ_PR_strong;
144     case Qualifiers::OCL_ExplicitNone:
145       return ObjCDeclSpec::DQ_PR_unsafe_unretained;
146     case Qualifiers::OCL_Autoreleasing:
147     case Qualifiers::OCL_None:
148       return 0;
149     }
150     llvm_unreachable("bad qualifier");
151   }
152 
153   return 0;
154 }
155 
156 static unsigned getOwnershipRule(unsigned attr) {
157   return attr & (ObjCPropertyDecl::OBJC_PR_assign |
158                  ObjCPropertyDecl::OBJC_PR_retain |
159                  ObjCPropertyDecl::OBJC_PR_copy   |
160                  ObjCPropertyDecl::OBJC_PR_weak   |
161                  ObjCPropertyDecl::OBJC_PR_strong |
162                  ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
163 }
164 
165 Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
166                           SourceLocation LParenLoc,
167                           FieldDeclarator &FD,
168                           ObjCDeclSpec &ODS,
169                           Selector GetterSel,
170                           Selector SetterSel,
171                           bool *isOverridingProperty,
172                           tok::ObjCKeywordKind MethodImplKind,
173                           DeclContext *lexicalDC) {
174   unsigned Attributes = ODS.getPropertyAttributes();
175   FD.D.setObjCWeakProperty((Attributes & ObjCDeclSpec::DQ_PR_weak) != 0);
176   TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
177   QualType T = TSI->getType();
178   if (!getOwnershipRule(Attributes)) {
179     Attributes |= deducePropertyOwnershipFromType(*this, T);
180   }
181   bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
182                       // default is readwrite!
183                       !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
184 
185   // Property defaults to 'assign' if it is readwrite, unless this is ARC
186   // and the type is retainable.
187   bool isAssign;
188   if (Attributes & (ObjCDeclSpec::DQ_PR_assign |
189                     ObjCDeclSpec::DQ_PR_unsafe_unretained)) {
190     isAssign = true;
191   } else if (getOwnershipRule(Attributes) || !isReadWrite) {
192     isAssign = false;
193   } else {
194     isAssign = (!getLangOpts().ObjCAutoRefCount ||
195                 !T->isObjCRetainableType());
196   }
197 
198   // Proceed with constructing the ObjCPropertyDecls.
199   ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
200   ObjCPropertyDecl *Res = nullptr;
201   if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
202     if (CDecl->IsClassExtension()) {
203       Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
204                                            FD, GetterSel, SetterSel,
205                                            isAssign, isReadWrite,
206                                            Attributes,
207                                            ODS.getPropertyAttributes(),
208                                            isOverridingProperty, T, TSI,
209                                            MethodImplKind);
210       if (!Res)
211         return nullptr;
212     }
213   }
214 
215   if (!Res) {
216     Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
217                              GetterSel, SetterSel, isAssign, isReadWrite,
218                              Attributes, ODS.getPropertyAttributes(),
219                              T, TSI, MethodImplKind);
220     if (lexicalDC)
221       Res->setLexicalDeclContext(lexicalDC);
222   }
223 
224   // Validate the attributes on the @property.
225   CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
226                               (isa<ObjCInterfaceDecl>(ClassDecl) ||
227                                isa<ObjCProtocolDecl>(ClassDecl)));
228 
229   // Check consistency if the type has explicit ownership qualification.
230   if (Res->getType().getObjCLifetime())
231     checkPropertyDeclWithOwnership(*this, Res);
232 
233   llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
234   if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
235     // For a class, compare the property against a property in our superclass.
236     bool FoundInSuper = false;
237     ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
238     while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
239       DeclContext::lookup_result R = Super->lookup(Res->getDeclName());
240       for (unsigned I = 0, N = R.size(); I != N; ++I) {
241         if (ObjCPropertyDecl *SuperProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
242           DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
243           FoundInSuper = true;
244           break;
245         }
246       }
247       if (FoundInSuper)
248         break;
249       else
250         CurrentInterfaceDecl = Super;
251     }
252 
253     if (FoundInSuper) {
254       // Also compare the property against a property in our protocols.
255       for (auto *P : CurrentInterfaceDecl->protocols()) {
256         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
257       }
258     } else {
259       // Slower path: look in all protocols we referenced.
260       for (auto *P : IFace->all_referenced_protocols()) {
261         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
262       }
263     }
264   } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
265     // We don't check if class extension. Because properties in class extension
266     // are meant to override some of the attributes and checking has already done
267     // when property in class extension is constructed.
268     if (!Cat->IsClassExtension())
269       for (auto *P : Cat->protocols())
270         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
271   } else {
272     ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
273     for (auto *P : Proto->protocols())
274       CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
275   }
276 
277   ActOnDocumentableDecl(Res);
278   return Res;
279 }
280 
281 static ObjCPropertyDecl::PropertyAttributeKind
282 makePropertyAttributesAsWritten(unsigned Attributes) {
283   unsigned attributesAsWritten = 0;
284   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
285     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
286   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
287     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
288   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
289     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
290   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
291     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
292   if (Attributes & ObjCDeclSpec::DQ_PR_assign)
293     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
294   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
295     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
296   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
297     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
298   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
299     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
300   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
301     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
302   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
303     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
304   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
305     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
306   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
307     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
308 
309   return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
310 }
311 
312 static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
313                                  SourceLocation LParenLoc, SourceLocation &Loc) {
314   if (LParenLoc.isMacroID())
315     return false;
316 
317   SourceManager &SM = Context.getSourceManager();
318   std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
319   // Try to load the file buffer.
320   bool invalidTemp = false;
321   StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
322   if (invalidTemp)
323     return false;
324   const char *tokenBegin = file.data() + locInfo.second;
325 
326   // Lex from the start of the given location.
327   Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
328               Context.getLangOpts(),
329               file.begin(), tokenBegin, file.end());
330   Token Tok;
331   do {
332     lexer.LexFromRawLexer(Tok);
333     if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
334       Loc = Tok.getLocation();
335       return true;
336     }
337   } while (Tok.isNot(tok::r_paren));
338   return false;
339 
340 }
341 
342 ObjCPropertyDecl *
343 Sema::HandlePropertyInClassExtension(Scope *S,
344                                      SourceLocation AtLoc,
345                                      SourceLocation LParenLoc,
346                                      FieldDeclarator &FD,
347                                      Selector GetterSel, Selector SetterSel,
348                                      const bool isAssign,
349                                      const bool isReadWrite,
350                                      const unsigned Attributes,
351                                      const unsigned AttributesAsWritten,
352                                      bool *isOverridingProperty,
353                                      QualType T,
354                                      TypeSourceInfo *TSI,
355                                      tok::ObjCKeywordKind MethodImplKind) {
356   ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
357   // Diagnose if this property is already in continuation class.
358   DeclContext *DC = CurContext;
359   IdentifierInfo *PropertyId = FD.D.getIdentifier();
360   ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
361 
362   // We need to look in the @interface to see if the @property was
363   // already declared.
364   if (!CCPrimary) {
365     Diag(CDecl->getLocation(), diag::err_continuation_class);
366     *isOverridingProperty = true;
367     return nullptr;
368   }
369 
370   // Find the property in the extended class's primary class or
371   // extensions.
372   ObjCPropertyDecl *PIDecl =
373     CCPrimary->FindPropertyVisibleInPrimaryClass(PropertyId);
374 
375   // If we found a property in an extension, complain.
376   if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
377     Diag(AtLoc, diag::err_duplicate_property);
378     Diag(PIDecl->getLocation(), diag::note_property_declare);
379     return nullptr;
380   }
381 
382   // Create a new ObjCPropertyDecl with the DeclContext being
383   // the class extension.
384   ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
385                                                FD, GetterSel, SetterSel,
386                                                isAssign, isReadWrite,
387                                                Attributes, AttributesAsWritten,
388                                                T, TSI, MethodImplKind, DC);
389 
390   // If there was no declaration of a property with the same name in
391   // the primary class, we're done.
392   if (!PIDecl) {
393     ProcessPropertyDecl(PDecl);
394     return PDecl;
395   }
396 
397   if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
398     bool IncompatibleObjC = false;
399     QualType ConvertedType;
400     // Relax the strict type matching for property type in continuation class.
401     // Allow property object type of continuation class to be different as long
402     // as it narrows the object type in its primary class property. Note that
403     // this conversion is safe only because the wider type is for a 'readonly'
404     // property in primary class and 'narrowed' type for a 'readwrite' property
405     // in continuation class.
406     QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
407     QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
408     if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
409         !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
410         (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
411                                   ConvertedType, IncompatibleObjC))
412         || IncompatibleObjC) {
413       Diag(AtLoc,
414           diag::err_type_mismatch_continuation_class) << PDecl->getType();
415       Diag(PIDecl->getLocation(), diag::note_property_declare);
416       return nullptr;
417     }
418   }
419 
420   // A readonly property declared in the primary class can be refined
421   // by adding a readwrite property within an extension.
422   // Anything else is an error.
423   unsigned PIkind = PIDecl->getPropertyAttributesAsWritten();
424   if (!(isReadWrite && (PIkind & ObjCPropertyDecl::OBJC_PR_readonly))) {
425     // Tailor the diagnostics for the common case where a readwrite
426     // property is declared both in the @interface and the continuation.
427     // This is a common error where the user often intended the original
428     // declaration to be readonly.
429     unsigned diag =
430       (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
431       (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite)
432       ? diag::err_use_continuation_class_redeclaration_readwrite
433       : diag::err_use_continuation_class;
434     Diag(AtLoc, diag)
435       << CCPrimary->getDeclName();
436     Diag(PIDecl->getLocation(), diag::note_property_declare);
437     return nullptr;
438   }
439 
440   PIkind &= ~ObjCPropertyDecl::OBJC_PR_readonly;
441   PIkind |= ObjCPropertyDecl::OBJC_PR_readwrite;
442   PIkind |= deducePropertyOwnershipFromType(*this, PIDecl->getType());
443   unsigned ClassExtensionMemoryModel = getOwnershipRule(Attributes);
444   unsigned PrimaryClassMemoryModel = getOwnershipRule(PIkind);
445   if (PrimaryClassMemoryModel && ClassExtensionMemoryModel &&
446       (PrimaryClassMemoryModel != ClassExtensionMemoryModel)) {
447     Diag(AtLoc, diag::warn_property_attr_mismatch);
448     Diag(PIDecl->getLocation(), diag::note_property_declare);
449   } else if (getLangOpts().ObjCAutoRefCount) {
450     QualType PrimaryPropertyQT =
451       Context.getCanonicalType(PIDecl->getType()).getUnqualifiedType();
452     if (isa<ObjCObjectPointerType>(PrimaryPropertyQT)) {
453       bool PropertyIsWeak = ((PIkind & ObjCPropertyDecl::OBJC_PR_weak) != 0);
454       Qualifiers::ObjCLifetime PrimaryPropertyLifeTime =
455         PrimaryPropertyQT.getObjCLifetime();
456       if (PrimaryPropertyLifeTime == Qualifiers::OCL_None &&
457           (Attributes & ObjCDeclSpec::DQ_PR_weak) &&
458           !PropertyIsWeak) {
459             Diag(AtLoc, diag::warn_property_implicitly_mismatched);
460             Diag(PIDecl->getLocation(), diag::note_property_declare);
461           }
462       }
463   }
464 
465   // Check that atomicity of property in class extension matches the previous
466   // declaration.
467   unsigned PDeclAtomicity =
468     PDecl->getPropertyAttributes() & (ObjCDeclSpec::DQ_PR_atomic | ObjCDeclSpec::DQ_PR_nonatomic);
469   unsigned PIDeclAtomicity =
470     PIDecl->getPropertyAttributes() & (ObjCDeclSpec::DQ_PR_atomic | ObjCDeclSpec::DQ_PR_nonatomic);
471   if (PDeclAtomicity != PIDeclAtomicity) {
472     bool PDeclAtomic = (!PDeclAtomicity || PDeclAtomicity & ObjCDeclSpec::DQ_PR_atomic);
473     bool PIDeclAtomic = (!PIDeclAtomicity || PIDeclAtomicity & ObjCDeclSpec::DQ_PR_atomic);
474     if (PDeclAtomic != PIDeclAtomic) {
475       Diag(PDecl->getLocation(), diag::warn_property_attribute)
476         << PDecl->getDeclName() << "atomic"
477         << cast<ObjCContainerDecl>(PIDecl->getDeclContext())->getName();
478       Diag(PIDecl->getLocation(), diag::note_property_declare);
479     }
480   }
481 
482   *isOverridingProperty = true;
483 
484   // Make sure getter/setter are appropriately synthesized.
485   ProcessPropertyDecl(PDecl);
486   return PDecl;
487 }
488 
489 ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
490                                            ObjCContainerDecl *CDecl,
491                                            SourceLocation AtLoc,
492                                            SourceLocation LParenLoc,
493                                            FieldDeclarator &FD,
494                                            Selector GetterSel,
495                                            Selector SetterSel,
496                                            const bool isAssign,
497                                            const bool isReadWrite,
498                                            const unsigned Attributes,
499                                            const unsigned AttributesAsWritten,
500                                            QualType T,
501                                            TypeSourceInfo *TInfo,
502                                            tok::ObjCKeywordKind MethodImplKind,
503                                            DeclContext *lexicalDC){
504   IdentifierInfo *PropertyId = FD.D.getIdentifier();
505 
506   // Issue a warning if property is 'assign' as default and its object, which is
507   // gc'able conforms to NSCopying protocol
508   if (getLangOpts().getGC() != LangOptions::NonGC &&
509       isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign))
510     if (const ObjCObjectPointerType *ObjPtrTy =
511           T->getAs<ObjCObjectPointerType>()) {
512       ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
513       if (IDecl)
514         if (ObjCProtocolDecl* PNSCopying =
515             LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
516           if (IDecl->ClassImplementsProtocol(PNSCopying, true))
517             Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
518     }
519 
520   if (T->isObjCObjectType()) {
521     SourceLocation StarLoc = TInfo->getTypeLoc().getLocEnd();
522     StarLoc = getLocForEndOfToken(StarLoc);
523     Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
524       << FixItHint::CreateInsertion(StarLoc, "*");
525     T = Context.getObjCObjectPointerType(T);
526     SourceLocation TLoc = TInfo->getTypeLoc().getLocStart();
527     TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
528   }
529 
530   DeclContext *DC = cast<DeclContext>(CDecl);
531   ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
532                                                      FD.D.getIdentifierLoc(),
533                                                      PropertyId, AtLoc,
534                                                      LParenLoc, T, TInfo);
535 
536   if (ObjCPropertyDecl *prevDecl =
537         ObjCPropertyDecl::findPropertyDecl(DC, PropertyId)) {
538     Diag(PDecl->getLocation(), diag::err_duplicate_property);
539     Diag(prevDecl->getLocation(), diag::note_property_declare);
540     PDecl->setInvalidDecl();
541   }
542   else {
543     DC->addDecl(PDecl);
544     if (lexicalDC)
545       PDecl->setLexicalDeclContext(lexicalDC);
546   }
547 
548   if (T->isArrayType() || T->isFunctionType()) {
549     Diag(AtLoc, diag::err_property_type) << T;
550     PDecl->setInvalidDecl();
551   }
552 
553   ProcessDeclAttributes(S, PDecl, FD.D);
554 
555   // Regardless of setter/getter attribute, we save the default getter/setter
556   // selector names in anticipation of declaration of setter/getter methods.
557   PDecl->setGetterName(GetterSel);
558   PDecl->setSetterName(SetterSel);
559   PDecl->setPropertyAttributesAsWritten(
560                           makePropertyAttributesAsWritten(AttributesAsWritten));
561 
562   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
563     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
564 
565   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
566     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
567 
568   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
569     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
570 
571   if (isReadWrite)
572     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
573 
574   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
575     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
576 
577   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
578     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
579 
580   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
581     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
582 
583   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
584     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
585 
586   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
587     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
588 
589   if (isAssign)
590     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
591 
592   // In the semantic attributes, one of nonatomic or atomic is always set.
593   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
594     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
595   else
596     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
597 
598   // 'unsafe_unretained' is alias for 'assign'.
599   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
600     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
601   if (isAssign)
602     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
603 
604   if (MethodImplKind == tok::objc_required)
605     PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
606   else if (MethodImplKind == tok::objc_optional)
607     PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
608 
609   if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
610     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
611 
612   if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
613     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
614 
615   return PDecl;
616 }
617 
618 static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
619                                  ObjCPropertyDecl *property,
620                                  ObjCIvarDecl *ivar) {
621   if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
622 
623   QualType ivarType = ivar->getType();
624   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
625 
626   // The lifetime implied by the property's attributes.
627   Qualifiers::ObjCLifetime propertyLifetime =
628     getImpliedARCOwnership(property->getPropertyAttributes(),
629                            property->getType());
630 
631   // We're fine if they match.
632   if (propertyLifetime == ivarLifetime) return;
633 
634   // None isn't a valid lifetime for an object ivar in ARC, and
635   // __autoreleasing is never valid; don't diagnose twice.
636   if ((ivarLifetime == Qualifiers::OCL_None &&
637        S.getLangOpts().ObjCAutoRefCount) ||
638       ivarLifetime == Qualifiers::OCL_Autoreleasing)
639     return;
640 
641   // If the ivar is private, and it's implicitly __unsafe_unretained
642   // becaues of its type, then pretend it was actually implicitly
643   // __strong.  This is only sound because we're processing the
644   // property implementation before parsing any method bodies.
645   if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
646       propertyLifetime == Qualifiers::OCL_Strong &&
647       ivar->getAccessControl() == ObjCIvarDecl::Private) {
648     SplitQualType split = ivarType.split();
649     if (split.Quals.hasObjCLifetime()) {
650       assert(ivarType->isObjCARCImplicitlyUnretainedType());
651       split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
652       ivarType = S.Context.getQualifiedType(split);
653       ivar->setType(ivarType);
654       return;
655     }
656   }
657 
658   switch (propertyLifetime) {
659   case Qualifiers::OCL_Strong:
660     S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
661       << property->getDeclName()
662       << ivar->getDeclName()
663       << ivarLifetime;
664     break;
665 
666   case Qualifiers::OCL_Weak:
667     S.Diag(ivar->getLocation(), diag::error_weak_property)
668       << property->getDeclName()
669       << ivar->getDeclName();
670     break;
671 
672   case Qualifiers::OCL_ExplicitNone:
673     S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
674       << property->getDeclName()
675       << ivar->getDeclName()
676       << ((property->getPropertyAttributesAsWritten()
677            & ObjCPropertyDecl::OBJC_PR_assign) != 0);
678     break;
679 
680   case Qualifiers::OCL_Autoreleasing:
681     llvm_unreachable("properties cannot be autoreleasing");
682 
683   case Qualifiers::OCL_None:
684     // Any other property should be ignored.
685     return;
686   }
687 
688   S.Diag(property->getLocation(), diag::note_property_declare);
689   if (propertyImplLoc.isValid())
690     S.Diag(propertyImplLoc, diag::note_property_synthesize);
691 }
692 
693 /// setImpliedPropertyAttributeForReadOnlyProperty -
694 /// This routine evaludates life-time attributes for a 'readonly'
695 /// property with no known lifetime of its own, using backing
696 /// 'ivar's attribute, if any. If no backing 'ivar', property's
697 /// life-time is assumed 'strong'.
698 static void setImpliedPropertyAttributeForReadOnlyProperty(
699               ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
700   Qualifiers::ObjCLifetime propertyLifetime =
701     getImpliedARCOwnership(property->getPropertyAttributes(),
702                            property->getType());
703   if (propertyLifetime != Qualifiers::OCL_None)
704     return;
705 
706   if (!ivar) {
707     // if no backing ivar, make property 'strong'.
708     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
709     return;
710   }
711   // property assumes owenership of backing ivar.
712   QualType ivarType = ivar->getType();
713   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
714   if (ivarLifetime == Qualifiers::OCL_Strong)
715     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
716   else if (ivarLifetime == Qualifiers::OCL_Weak)
717     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
718   return;
719 }
720 
721 /// DiagnosePropertyMismatchDeclInProtocols - diagnose properties declared
722 /// in inherited protocols with mismatched types. Since any of them can
723 /// be candidate for synthesis.
724 static void
725 DiagnosePropertyMismatchDeclInProtocols(Sema &S, SourceLocation AtLoc,
726                                         ObjCInterfaceDecl *ClassDecl,
727                                         ObjCPropertyDecl *Property) {
728   ObjCInterfaceDecl::ProtocolPropertyMap PropMap;
729   for (const auto *PI : ClassDecl->all_referenced_protocols()) {
730     if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
731       PDecl->collectInheritedProtocolProperties(Property, PropMap);
732   }
733   if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass())
734     while (SDecl) {
735       for (const auto *PI : SDecl->all_referenced_protocols()) {
736         if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
737           PDecl->collectInheritedProtocolProperties(Property, PropMap);
738       }
739       SDecl = SDecl->getSuperClass();
740     }
741 
742   if (PropMap.empty())
743     return;
744 
745   QualType RHSType = S.Context.getCanonicalType(Property->getType());
746   bool FirsTime = true;
747   for (ObjCInterfaceDecl::ProtocolPropertyMap::iterator
748        I = PropMap.begin(), E = PropMap.end(); I != E; I++) {
749     ObjCPropertyDecl *Prop = I->second;
750     QualType LHSType = S.Context.getCanonicalType(Prop->getType());
751     if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
752       bool IncompatibleObjC = false;
753       QualType ConvertedType;
754       if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
755           || IncompatibleObjC) {
756         if (FirsTime) {
757           S.Diag(Property->getLocation(), diag::warn_protocol_property_mismatch)
758             << Property->getType();
759           FirsTime = false;
760         }
761         S.Diag(Prop->getLocation(), diag::note_protocol_property_declare)
762           << Prop->getType();
763       }
764     }
765   }
766   if (!FirsTime && AtLoc.isValid())
767     S.Diag(AtLoc, diag::note_property_synthesize);
768 }
769 
770 /// ActOnPropertyImplDecl - This routine performs semantic checks and
771 /// builds the AST node for a property implementation declaration; declared
772 /// as \@synthesize or \@dynamic.
773 ///
774 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
775                                   SourceLocation AtLoc,
776                                   SourceLocation PropertyLoc,
777                                   bool Synthesize,
778                                   IdentifierInfo *PropertyId,
779                                   IdentifierInfo *PropertyIvar,
780                                   SourceLocation PropertyIvarLoc) {
781   ObjCContainerDecl *ClassImpDecl =
782     dyn_cast<ObjCContainerDecl>(CurContext);
783   // Make sure we have a context for the property implementation declaration.
784   if (!ClassImpDecl) {
785     Diag(AtLoc, diag::error_missing_property_context);
786     return nullptr;
787   }
788   if (PropertyIvarLoc.isInvalid())
789     PropertyIvarLoc = PropertyLoc;
790   SourceLocation PropertyDiagLoc = PropertyLoc;
791   if (PropertyDiagLoc.isInvalid())
792     PropertyDiagLoc = ClassImpDecl->getLocStart();
793   ObjCPropertyDecl *property = nullptr;
794   ObjCInterfaceDecl *IDecl = nullptr;
795   // Find the class or category class where this property must have
796   // a declaration.
797   ObjCImplementationDecl *IC = nullptr;
798   ObjCCategoryImplDecl *CatImplClass = nullptr;
799   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
800     IDecl = IC->getClassInterface();
801     // We always synthesize an interface for an implementation
802     // without an interface decl. So, IDecl is always non-zero.
803     assert(IDecl &&
804            "ActOnPropertyImplDecl - @implementation without @interface");
805 
806     // Look for this property declaration in the @implementation's @interface
807     property = IDecl->FindPropertyDeclaration(PropertyId);
808     if (!property) {
809       Diag(PropertyLoc, diag::error_bad_property_decl) << IDecl->getDeclName();
810       return nullptr;
811     }
812     unsigned PIkind = property->getPropertyAttributesAsWritten();
813     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
814                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
815       if (AtLoc.isValid())
816         Diag(AtLoc, diag::warn_implicit_atomic_property);
817       else
818         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
819       Diag(property->getLocation(), diag::note_property_declare);
820     }
821 
822     if (const ObjCCategoryDecl *CD =
823         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
824       if (!CD->IsClassExtension()) {
825         Diag(PropertyLoc, diag::error_category_property) << CD->getDeclName();
826         Diag(property->getLocation(), diag::note_property_declare);
827         return nullptr;
828       }
829     }
830     if (Synthesize&&
831         (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
832         property->hasAttr<IBOutletAttr>() &&
833         !AtLoc.isValid()) {
834       bool ReadWriteProperty = false;
835       // Search into the class extensions and see if 'readonly property is
836       // redeclared 'readwrite', then no warning is to be issued.
837       for (auto *Ext : IDecl->known_extensions()) {
838         DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
839         if (!R.empty())
840           if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
841             PIkind = ExtProp->getPropertyAttributesAsWritten();
842             if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
843               ReadWriteProperty = true;
844               break;
845             }
846           }
847       }
848 
849       if (!ReadWriteProperty) {
850         Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
851             << property;
852         SourceLocation readonlyLoc;
853         if (LocPropertyAttribute(Context, "readonly",
854                                  property->getLParenLoc(), readonlyLoc)) {
855           SourceLocation endLoc =
856             readonlyLoc.getLocWithOffset(strlen("readonly")-1);
857           SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
858           Diag(property->getLocation(),
859                diag::note_auto_readonly_iboutlet_fixup_suggest) <<
860           FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
861         }
862       }
863     }
864     if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
865       DiagnosePropertyMismatchDeclInProtocols(*this, AtLoc, IDecl, property);
866 
867   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
868     if (Synthesize) {
869       Diag(AtLoc, diag::error_synthesize_category_decl);
870       return nullptr;
871     }
872     IDecl = CatImplClass->getClassInterface();
873     if (!IDecl) {
874       Diag(AtLoc, diag::error_missing_property_interface);
875       return nullptr;
876     }
877     ObjCCategoryDecl *Category =
878     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
879 
880     // If category for this implementation not found, it is an error which
881     // has already been reported eralier.
882     if (!Category)
883       return nullptr;
884     // Look for this property declaration in @implementation's category
885     property = Category->FindPropertyDeclaration(PropertyId);
886     if (!property) {
887       Diag(PropertyLoc, diag::error_bad_category_property_decl)
888       << Category->getDeclName();
889       return nullptr;
890     }
891   } else {
892     Diag(AtLoc, diag::error_bad_property_context);
893     return nullptr;
894   }
895   ObjCIvarDecl *Ivar = nullptr;
896   bool CompleteTypeErr = false;
897   bool compat = true;
898   // Check that we have a valid, previously declared ivar for @synthesize
899   if (Synthesize) {
900     // @synthesize
901     if (!PropertyIvar)
902       PropertyIvar = PropertyId;
903     // Check that this is a previously declared 'ivar' in 'IDecl' interface
904     ObjCInterfaceDecl *ClassDeclared;
905     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
906     QualType PropType = property->getType();
907     QualType PropertyIvarType = PropType.getNonReferenceType();
908 
909     if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
910                             diag::err_incomplete_synthesized_property,
911                             property->getDeclName())) {
912       Diag(property->getLocation(), diag::note_property_declare);
913       CompleteTypeErr = true;
914     }
915 
916     if (getLangOpts().ObjCAutoRefCount &&
917         (property->getPropertyAttributesAsWritten() &
918          ObjCPropertyDecl::OBJC_PR_readonly) &&
919         PropertyIvarType->isObjCRetainableType()) {
920       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
921     }
922 
923     ObjCPropertyDecl::PropertyAttributeKind kind
924       = property->getPropertyAttributes();
925 
926     bool isARCWeak = false;
927     if (kind & ObjCPropertyDecl::OBJC_PR_weak) {
928       // Add GC __weak to the ivar type if the property is weak.
929       if (getLangOpts().getGC() != LangOptions::NonGC) {
930         assert(!getLangOpts().ObjCAutoRefCount);
931         if (PropertyIvarType.isObjCGCStrong()) {
932           Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
933           Diag(property->getLocation(), diag::note_property_declare);
934         } else {
935           PropertyIvarType =
936             Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
937         }
938 
939       // Otherwise, check whether ARC __weak is enabled and works with
940       // the property type.
941       } else {
942         if (!getLangOpts().ObjCWeak) {
943           // Only complain here when synthesizing an ivar.
944           if (!Ivar) {
945             Diag(PropertyDiagLoc,
946                  getLangOpts().ObjCWeakRuntime
947                    ? diag::err_synthesizing_arc_weak_property_disabled
948                    : diag::err_synthesizing_arc_weak_property_no_runtime);
949             Diag(property->getLocation(), diag::note_property_declare);
950           }
951           CompleteTypeErr = true; // suppress later diagnostics about the ivar
952         } else {
953           isARCWeak = true;
954           if (const ObjCObjectPointerType *ObjT =
955                 PropertyIvarType->getAs<ObjCObjectPointerType>()) {
956             const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
957             if (ObjI && ObjI->isArcWeakrefUnavailable()) {
958               Diag(property->getLocation(),
959                    diag::err_arc_weak_unavailable_property)
960                 << PropertyIvarType;
961               Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
962                 << ClassImpDecl->getName();
963             }
964           }
965         }
966       }
967     }
968 
969     if (AtLoc.isInvalid()) {
970       // Check when default synthesizing a property that there is
971       // an ivar matching property name and issue warning; since this
972       // is the most common case of not using an ivar used for backing
973       // property in non-default synthesis case.
974       ObjCInterfaceDecl *ClassDeclared=nullptr;
975       ObjCIvarDecl *originalIvar =
976       IDecl->lookupInstanceVariable(property->getIdentifier(),
977                                     ClassDeclared);
978       if (originalIvar) {
979         Diag(PropertyDiagLoc,
980              diag::warn_autosynthesis_property_ivar_match)
981         << PropertyId << (Ivar == nullptr) << PropertyIvar
982         << originalIvar->getIdentifier();
983         Diag(property->getLocation(), diag::note_property_declare);
984         Diag(originalIvar->getLocation(), diag::note_ivar_decl);
985       }
986     }
987 
988     if (!Ivar) {
989       // In ARC, give the ivar a lifetime qualifier based on the
990       // property attributes.
991       if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
992           !PropertyIvarType.getObjCLifetime() &&
993           PropertyIvarType->isObjCRetainableType()) {
994 
995         // It's an error if we have to do this and the user didn't
996         // explicitly write an ownership attribute on the property.
997         if (!property->hasWrittenStorageAttribute() &&
998             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
999           Diag(PropertyDiagLoc,
1000                diag::err_arc_objc_property_default_assign_on_object);
1001           Diag(property->getLocation(), diag::note_property_declare);
1002         } else {
1003           Qualifiers::ObjCLifetime lifetime =
1004             getImpliedARCOwnership(kind, PropertyIvarType);
1005           assert(lifetime && "no lifetime for property?");
1006 
1007           Qualifiers qs;
1008           qs.addObjCLifetime(lifetime);
1009           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1010         }
1011       }
1012 
1013       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1014                                   PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1015                                   PropertyIvarType, /*Dinfo=*/nullptr,
1016                                   ObjCIvarDecl::Private,
1017                                   (Expr *)nullptr, true);
1018       if (RequireNonAbstractType(PropertyIvarLoc,
1019                                  PropertyIvarType,
1020                                  diag::err_abstract_type_in_decl,
1021                                  AbstractSynthesizedIvarType)) {
1022         Diag(property->getLocation(), diag::note_property_declare);
1023         Ivar->setInvalidDecl();
1024       } else if (CompleteTypeErr)
1025           Ivar->setInvalidDecl();
1026       ClassImpDecl->addDecl(Ivar);
1027       IDecl->makeDeclVisibleInContext(Ivar);
1028 
1029       if (getLangOpts().ObjCRuntime.isFragile())
1030         Diag(PropertyDiagLoc, diag::error_missing_property_ivar_decl)
1031             << PropertyId;
1032       // Note! I deliberately want it to fall thru so, we have a
1033       // a property implementation and to avoid future warnings.
1034     } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1035                !declaresSameEntity(ClassDeclared, IDecl)) {
1036       Diag(PropertyDiagLoc, diag::error_ivar_in_superclass_use)
1037       << property->getDeclName() << Ivar->getDeclName()
1038       << ClassDeclared->getDeclName();
1039       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1040       << Ivar << Ivar->getName();
1041       // Note! I deliberately want it to fall thru so more errors are caught.
1042     }
1043     property->setPropertyIvarDecl(Ivar);
1044 
1045     QualType IvarType = Context.getCanonicalType(Ivar->getType());
1046 
1047     // Check that type of property and its ivar are type compatible.
1048     if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1049       if (isa<ObjCObjectPointerType>(PropertyIvarType)
1050           && isa<ObjCObjectPointerType>(IvarType))
1051         compat =
1052           Context.canAssignObjCInterfaces(
1053                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
1054                                   IvarType->getAs<ObjCObjectPointerType>());
1055       else {
1056         compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1057                                              IvarType)
1058                     == Compatible);
1059       }
1060       if (!compat) {
1061         Diag(PropertyDiagLoc, diag::error_property_ivar_type)
1062           << property->getDeclName() << PropType
1063           << Ivar->getDeclName() << IvarType;
1064         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1065         // Note! I deliberately want it to fall thru so, we have a
1066         // a property implementation and to avoid future warnings.
1067       }
1068       else {
1069         // FIXME! Rules for properties are somewhat different that those
1070         // for assignments. Use a new routine to consolidate all cases;
1071         // specifically for property redeclarations as well as for ivars.
1072         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1073         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1074         if (lhsType != rhsType &&
1075             lhsType->isArithmeticType()) {
1076           Diag(PropertyDiagLoc, diag::error_property_ivar_type)
1077             << property->getDeclName() << PropType
1078             << Ivar->getDeclName() << IvarType;
1079           Diag(Ivar->getLocation(), diag::note_ivar_decl);
1080           // Fall thru - see previous comment
1081         }
1082       }
1083       // __weak is explicit. So it works on Canonical type.
1084       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1085            getLangOpts().getGC() != LangOptions::NonGC)) {
1086         Diag(PropertyDiagLoc, diag::error_weak_property)
1087         << property->getDeclName() << Ivar->getDeclName();
1088         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1089         // Fall thru - see previous comment
1090       }
1091       // Fall thru - see previous comment
1092       if ((property->getType()->isObjCObjectPointerType() ||
1093            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1094           getLangOpts().getGC() != LangOptions::NonGC) {
1095         Diag(PropertyDiagLoc, diag::error_strong_property)
1096         << property->getDeclName() << Ivar->getDeclName();
1097         // Fall thru - see previous comment
1098       }
1099     }
1100     if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1101         Ivar->getType().getObjCLifetime())
1102       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1103   } else if (PropertyIvar)
1104     // @dynamic
1105     Diag(PropertyDiagLoc, diag::error_dynamic_property_ivar_decl);
1106 
1107   assert (property && "ActOnPropertyImplDecl - property declaration missing");
1108   ObjCPropertyImplDecl *PIDecl =
1109   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1110                                property,
1111                                (Synthesize ?
1112                                 ObjCPropertyImplDecl::Synthesize
1113                                 : ObjCPropertyImplDecl::Dynamic),
1114                                Ivar, PropertyIvarLoc);
1115 
1116   if (CompleteTypeErr || !compat)
1117     PIDecl->setInvalidDecl();
1118 
1119   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1120     getterMethod->createImplicitParams(Context, IDecl);
1121     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1122         Ivar->getType()->isRecordType()) {
1123       // For Objective-C++, need to synthesize the AST for the IVAR object to be
1124       // returned by the getter as it must conform to C++'s copy-return rules.
1125       // FIXME. Eventually we want to do this for Objective-C as well.
1126       SynthesizedFunctionScope Scope(*this, getterMethod);
1127       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1128       DeclRefExpr *SelfExpr =
1129         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1130                                   VK_LValue, PropertyDiagLoc);
1131       MarkDeclRefReferenced(SelfExpr);
1132       Expr *LoadSelfExpr =
1133         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1134                                  CK_LValueToRValue, SelfExpr, nullptr,
1135                                  VK_RValue);
1136       Expr *IvarRefExpr =
1137         new (Context) ObjCIvarRefExpr(Ivar,
1138                                       Ivar->getUsageType(SelfDecl->getType()),
1139                                       PropertyDiagLoc,
1140                                       Ivar->getLocation(),
1141                                       LoadSelfExpr, true, true);
1142       ExprResult Res = PerformCopyInitialization(
1143           InitializedEntity::InitializeResult(PropertyDiagLoc,
1144                                               getterMethod->getReturnType(),
1145                                               /*NRVO=*/false),
1146           PropertyDiagLoc, IvarRefExpr);
1147       if (!Res.isInvalid()) {
1148         Expr *ResExpr = Res.getAs<Expr>();
1149         if (ResExpr)
1150           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1151         PIDecl->setGetterCXXConstructor(ResExpr);
1152       }
1153     }
1154     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1155         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1156       Diag(getterMethod->getLocation(),
1157            diag::warn_property_getter_owning_mismatch);
1158       Diag(property->getLocation(), diag::note_property_declare);
1159     }
1160     if (getLangOpts().ObjCAutoRefCount && Synthesize)
1161       switch (getterMethod->getMethodFamily()) {
1162         case OMF_retain:
1163         case OMF_retainCount:
1164         case OMF_release:
1165         case OMF_autorelease:
1166           Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1167             << 1 << getterMethod->getSelector();
1168           break;
1169         default:
1170           break;
1171       }
1172   }
1173   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1174     setterMethod->createImplicitParams(Context, IDecl);
1175     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1176         Ivar->getType()->isRecordType()) {
1177       // FIXME. Eventually we want to do this for Objective-C as well.
1178       SynthesizedFunctionScope Scope(*this, setterMethod);
1179       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1180       DeclRefExpr *SelfExpr =
1181         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1182                                   VK_LValue, PropertyDiagLoc);
1183       MarkDeclRefReferenced(SelfExpr);
1184       Expr *LoadSelfExpr =
1185         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1186                                  CK_LValueToRValue, SelfExpr, nullptr,
1187                                  VK_RValue);
1188       Expr *lhs =
1189         new (Context) ObjCIvarRefExpr(Ivar,
1190                                       Ivar->getUsageType(SelfDecl->getType()),
1191                                       PropertyDiagLoc,
1192                                       Ivar->getLocation(),
1193                                       LoadSelfExpr, true, true);
1194       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1195       ParmVarDecl *Param = (*P);
1196       QualType T = Param->getType().getNonReferenceType();
1197       DeclRefExpr *rhs = new (Context) DeclRefExpr(Param, false, T,
1198                                                    VK_LValue, PropertyDiagLoc);
1199       MarkDeclRefReferenced(rhs);
1200       ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1201                                   BO_Assign, lhs, rhs);
1202       if (property->getPropertyAttributes() &
1203           ObjCPropertyDecl::OBJC_PR_atomic) {
1204         Expr *callExpr = Res.getAs<Expr>();
1205         if (const CXXOperatorCallExpr *CXXCE =
1206               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1207           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1208             if (!FuncDecl->isTrivial())
1209               if (property->getType()->isReferenceType()) {
1210                 Diag(PropertyDiagLoc,
1211                      diag::err_atomic_property_nontrivial_assign_op)
1212                     << property->getType();
1213                 Diag(FuncDecl->getLocStart(),
1214                      diag::note_callee_decl) << FuncDecl;
1215               }
1216       }
1217       PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1218     }
1219   }
1220 
1221   if (IC) {
1222     if (Synthesize)
1223       if (ObjCPropertyImplDecl *PPIDecl =
1224           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1225         Diag(PropertyLoc, diag::error_duplicate_ivar_use)
1226         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1227         << PropertyIvar;
1228         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1229       }
1230 
1231     if (ObjCPropertyImplDecl *PPIDecl
1232         = IC->FindPropertyImplDecl(PropertyId)) {
1233       Diag(PropertyLoc, diag::error_property_implemented) << PropertyId;
1234       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1235       return nullptr;
1236     }
1237     IC->addPropertyImplementation(PIDecl);
1238     if (getLangOpts().ObjCDefaultSynthProperties &&
1239         getLangOpts().ObjCRuntime.isNonFragile() &&
1240         !IDecl->isObjCRequiresPropertyDefs()) {
1241       // Diagnose if an ivar was lazily synthesdized due to a previous
1242       // use and if 1) property is @dynamic or 2) property is synthesized
1243       // but it requires an ivar of different name.
1244       ObjCInterfaceDecl *ClassDeclared=nullptr;
1245       ObjCIvarDecl *Ivar = nullptr;
1246       if (!Synthesize)
1247         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1248       else {
1249         if (PropertyIvar && PropertyIvar != PropertyId)
1250           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1251       }
1252       // Issue diagnostics only if Ivar belongs to current class.
1253       if (Ivar && Ivar->getSynthesize() &&
1254           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1255         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1256         << PropertyId;
1257         Ivar->setInvalidDecl();
1258       }
1259     }
1260   } else {
1261     if (Synthesize)
1262       if (ObjCPropertyImplDecl *PPIDecl =
1263           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1264         Diag(PropertyDiagLoc, diag::error_duplicate_ivar_use)
1265         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1266         << PropertyIvar;
1267         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1268       }
1269 
1270     if (ObjCPropertyImplDecl *PPIDecl =
1271         CatImplClass->FindPropertyImplDecl(PropertyId)) {
1272       Diag(PropertyDiagLoc, diag::error_property_implemented) << PropertyId;
1273       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1274       return nullptr;
1275     }
1276     CatImplClass->addPropertyImplementation(PIDecl);
1277   }
1278 
1279   return PIDecl;
1280 }
1281 
1282 //===----------------------------------------------------------------------===//
1283 // Helper methods.
1284 //===----------------------------------------------------------------------===//
1285 
1286 /// DiagnosePropertyMismatch - Compares two properties for their
1287 /// attributes and types and warns on a variety of inconsistencies.
1288 ///
1289 void
1290 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1291                                ObjCPropertyDecl *SuperProperty,
1292                                const IdentifierInfo *inheritedName,
1293                                bool OverridingProtocolProperty) {
1294   ObjCPropertyDecl::PropertyAttributeKind CAttr =
1295     Property->getPropertyAttributes();
1296   ObjCPropertyDecl::PropertyAttributeKind SAttr =
1297     SuperProperty->getPropertyAttributes();
1298 
1299   // We allow readonly properties without an explicit ownership
1300   // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1301   // to be overridden by a property with any explicit ownership in the subclass.
1302   if (!OverridingProtocolProperty &&
1303       !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1304     ;
1305   else {
1306     if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
1307         && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
1308       Diag(Property->getLocation(), diag::warn_readonly_property)
1309         << Property->getDeclName() << inheritedName;
1310     if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
1311         != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
1312       Diag(Property->getLocation(), diag::warn_property_attribute)
1313         << Property->getDeclName() << "copy" << inheritedName;
1314     else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
1315       unsigned CAttrRetain =
1316         (CAttr &
1317          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1318       unsigned SAttrRetain =
1319         (SAttr &
1320          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1321       bool CStrong = (CAttrRetain != 0);
1322       bool SStrong = (SAttrRetain != 0);
1323       if (CStrong != SStrong)
1324         Diag(Property->getLocation(), diag::warn_property_attribute)
1325           << Property->getDeclName() << "retain (or strong)" << inheritedName;
1326     }
1327   }
1328 
1329   if ((CAttr & ObjCPropertyDecl::OBJC_PR_nonatomic)
1330       != (SAttr & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
1331     Diag(Property->getLocation(), diag::warn_property_attribute)
1332       << Property->getDeclName() << "atomic" << inheritedName;
1333     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1334   }
1335   if (Property->getSetterName() != SuperProperty->getSetterName()) {
1336     Diag(Property->getLocation(), diag::warn_property_attribute)
1337       << Property->getDeclName() << "setter" << inheritedName;
1338     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1339   }
1340   if (Property->getGetterName() != SuperProperty->getGetterName()) {
1341     Diag(Property->getLocation(), diag::warn_property_attribute)
1342       << Property->getDeclName() << "getter" << inheritedName;
1343     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1344   }
1345 
1346   QualType LHSType =
1347     Context.getCanonicalType(SuperProperty->getType());
1348   QualType RHSType =
1349     Context.getCanonicalType(Property->getType());
1350 
1351   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1352     // Do cases not handled in above.
1353     // FIXME. For future support of covariant property types, revisit this.
1354     bool IncompatibleObjC = false;
1355     QualType ConvertedType;
1356     if (!isObjCPointerConversion(RHSType, LHSType,
1357                                  ConvertedType, IncompatibleObjC) ||
1358         IncompatibleObjC) {
1359         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1360         << Property->getType() << SuperProperty->getType() << inheritedName;
1361       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1362     }
1363   }
1364 }
1365 
1366 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1367                                             ObjCMethodDecl *GetterMethod,
1368                                             SourceLocation Loc) {
1369   if (!GetterMethod)
1370     return false;
1371   QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1372   QualType PropertyIvarType = property->getType().getNonReferenceType();
1373   bool compat = Context.hasSameType(PropertyIvarType, GetterType);
1374   if (!compat) {
1375     if (isa<ObjCObjectPointerType>(PropertyIvarType) &&
1376         isa<ObjCObjectPointerType>(GetterType))
1377       compat =
1378         Context.canAssignObjCInterfaces(
1379                                       GetterType->getAs<ObjCObjectPointerType>(),
1380                                       PropertyIvarType->getAs<ObjCObjectPointerType>());
1381     else if (CheckAssignmentConstraints(Loc, GetterType, PropertyIvarType)
1382               != Compatible) {
1383           Diag(Loc, diag::error_property_accessor_type)
1384             << property->getDeclName() << PropertyIvarType
1385             << GetterMethod->getSelector() << GetterType;
1386           Diag(GetterMethod->getLocation(), diag::note_declared_at);
1387           return true;
1388     } else {
1389       compat = true;
1390       QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1391       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1392       if (lhsType != rhsType && lhsType->isArithmeticType())
1393         compat = false;
1394     }
1395   }
1396 
1397   if (!compat) {
1398     Diag(Loc, diag::warn_accessor_property_type_mismatch)
1399     << property->getDeclName()
1400     << GetterMethod->getSelector();
1401     Diag(GetterMethod->getLocation(), diag::note_declared_at);
1402     return true;
1403   }
1404 
1405   return false;
1406 }
1407 
1408 /// CollectImmediateProperties - This routine collects all properties in
1409 /// the class and its conforming protocols; but not those in its super class.
1410 static void CollectImmediateProperties(ObjCContainerDecl *CDecl,
1411                                        ObjCContainerDecl::PropertyMap &PropMap,
1412                                        ObjCContainerDecl::PropertyMap &SuperPropMap,
1413                                        bool IncludeProtocols = true) {
1414 
1415   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1416     for (auto *Prop : IDecl->properties())
1417       PropMap[Prop->getIdentifier()] = Prop;
1418 
1419     // Collect the properties from visible extensions.
1420     for (auto *Ext : IDecl->visible_extensions())
1421       CollectImmediateProperties(Ext, PropMap, SuperPropMap, IncludeProtocols);
1422 
1423     if (IncludeProtocols) {
1424       // Scan through class's protocols.
1425       for (auto *PI : IDecl->all_referenced_protocols())
1426         CollectImmediateProperties(PI, PropMap, SuperPropMap);
1427     }
1428   }
1429   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1430     for (auto *Prop : CATDecl->properties())
1431       PropMap[Prop->getIdentifier()] = Prop;
1432     if (IncludeProtocols) {
1433       // Scan through class's protocols.
1434       for (auto *PI : CATDecl->protocols())
1435         CollectImmediateProperties(PI, PropMap, SuperPropMap);
1436     }
1437   }
1438   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1439     for (auto *Prop : PDecl->properties()) {
1440       ObjCPropertyDecl *PropertyFromSuper = SuperPropMap[Prop->getIdentifier()];
1441       // Exclude property for protocols which conform to class's super-class,
1442       // as super-class has to implement the property.
1443       if (!PropertyFromSuper ||
1444           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1445         ObjCPropertyDecl *&PropEntry = PropMap[Prop->getIdentifier()];
1446         if (!PropEntry)
1447           PropEntry = Prop;
1448       }
1449     }
1450     // scan through protocol's protocols.
1451     for (auto *PI : PDecl->protocols())
1452       CollectImmediateProperties(PI, PropMap, SuperPropMap);
1453   }
1454 }
1455 
1456 /// CollectSuperClassPropertyImplementations - This routine collects list of
1457 /// properties to be implemented in super class(s) and also coming from their
1458 /// conforming protocols.
1459 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1460                                     ObjCInterfaceDecl::PropertyMap &PropMap) {
1461   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1462     ObjCInterfaceDecl::PropertyDeclOrder PO;
1463     while (SDecl) {
1464       SDecl->collectPropertiesToImplement(PropMap, PO);
1465       SDecl = SDecl->getSuperClass();
1466     }
1467   }
1468 }
1469 
1470 /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1471 /// an ivar synthesized for 'Method' and 'Method' is a property accessor
1472 /// declared in class 'IFace'.
1473 bool
1474 Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1475                                      ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1476   if (!IV->getSynthesize())
1477     return false;
1478   ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1479                                             Method->isInstanceMethod());
1480   if (!IMD || !IMD->isPropertyAccessor())
1481     return false;
1482 
1483   // look up a property declaration whose one of its accessors is implemented
1484   // by this method.
1485   for (const auto *Property : IFace->properties()) {
1486     if ((Property->getGetterName() == IMD->getSelector() ||
1487          Property->getSetterName() == IMD->getSelector()) &&
1488         (Property->getPropertyIvarDecl() == IV))
1489       return true;
1490   }
1491   // Also look up property declaration in class extension whose one of its
1492   // accessors is implemented by this method.
1493   for (const auto *Ext : IFace->known_extensions())
1494     for (const auto *Property : Ext->properties())
1495       if ((Property->getGetterName() == IMD->getSelector() ||
1496            Property->getSetterName() == IMD->getSelector()) &&
1497           (Property->getPropertyIvarDecl() == IV))
1498         return true;
1499   return false;
1500 }
1501 
1502 static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1503                                          ObjCPropertyDecl *Prop) {
1504   bool SuperClassImplementsGetter = false;
1505   bool SuperClassImplementsSetter = false;
1506   if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1507     SuperClassImplementsSetter = true;
1508 
1509   while (IDecl->getSuperClass()) {
1510     ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1511     if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1512       SuperClassImplementsGetter = true;
1513 
1514     if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1515       SuperClassImplementsSetter = true;
1516     if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1517       return true;
1518     IDecl = IDecl->getSuperClass();
1519   }
1520   return false;
1521 }
1522 
1523 /// \brief Default synthesizes all properties which must be synthesized
1524 /// in class's \@implementation.
1525 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl* IMPDecl,
1526                                        ObjCInterfaceDecl *IDecl) {
1527 
1528   ObjCInterfaceDecl::PropertyMap PropMap;
1529   ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
1530   IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
1531   if (PropMap.empty())
1532     return;
1533   ObjCInterfaceDecl::PropertyMap SuperPropMap;
1534   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1535 
1536   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
1537     ObjCPropertyDecl *Prop = PropertyOrder[i];
1538     // Is there a matching property synthesize/dynamic?
1539     if (Prop->isInvalidDecl() ||
1540         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1541       continue;
1542     // Property may have been synthesized by user.
1543     if (IMPDecl->FindPropertyImplDecl(Prop->getIdentifier()))
1544       continue;
1545     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1546       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1547         continue;
1548       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1549         continue;
1550     }
1551     if (ObjCPropertyImplDecl *PID =
1552         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1553       Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1554         << Prop->getIdentifier();
1555       if (PID->getLocation().isValid())
1556         Diag(PID->getLocation(), diag::note_property_synthesize);
1557       continue;
1558     }
1559     ObjCPropertyDecl *PropInSuperClass = SuperPropMap[Prop->getIdentifier()];
1560     if (ObjCProtocolDecl *Proto =
1561           dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1562       // We won't auto-synthesize properties declared in protocols.
1563       // Suppress the warning if class's superclass implements property's
1564       // getter and implements property's setter (if readwrite property).
1565       // Or, if property is going to be implemented in its super class.
1566       if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1567         Diag(IMPDecl->getLocation(),
1568              diag::warn_auto_synthesizing_protocol_property)
1569           << Prop << Proto;
1570         Diag(Prop->getLocation(), diag::note_property_declare);
1571       }
1572       continue;
1573     }
1574     // If property to be implemented in the super class, ignore.
1575     if (PropInSuperClass) {
1576       if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
1577           (PropInSuperClass->getPropertyAttributes() &
1578            ObjCPropertyDecl::OBJC_PR_readonly) &&
1579           !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1580           !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1581         Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1582         << Prop->getIdentifier();
1583         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1584       }
1585       else {
1586         Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1587         << Prop->getIdentifier();
1588         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1589         Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1590       }
1591       continue;
1592     }
1593     // We use invalid SourceLocations for the synthesized ivars since they
1594     // aren't really synthesized at a particular location; they just exist.
1595     // Saying that they are located at the @implementation isn't really going
1596     // to help users.
1597     ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1598       ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1599                             true,
1600                             /* property = */ Prop->getIdentifier(),
1601                             /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1602                             Prop->getLocation()));
1603     if (PIDecl) {
1604       Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1605       Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1606     }
1607   }
1608 }
1609 
1610 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D) {
1611   if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1612     return;
1613   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1614   if (!IC)
1615     return;
1616   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1617     if (!IDecl->isObjCRequiresPropertyDefs())
1618       DefaultSynthesizeProperties(S, IC, IDecl);
1619 }
1620 
1621 static void DiagnoseUnimplementedAccessor(Sema &S,
1622                                           ObjCInterfaceDecl *PrimaryClass,
1623                                           Selector Method,
1624                                           ObjCImplDecl* IMPDecl,
1625                                           ObjCContainerDecl *CDecl,
1626                                           ObjCCategoryDecl *C,
1627                                           ObjCPropertyDecl *Prop,
1628                                           Sema::SelectorSet &SMap) {
1629   // When reporting on missing property setter/getter implementation in
1630   // categories, do not report when they are declared in primary class,
1631   // class's protocol, or one of it super classes. This is because,
1632   // the class is going to implement them.
1633   if (!SMap.count(Method) &&
1634       (PrimaryClass == nullptr ||
1635        !PrimaryClass->lookupPropertyAccessor(Method, C))) {
1636         S.Diag(IMPDecl->getLocation(),
1637                isa<ObjCCategoryDecl>(CDecl) ?
1638                diag::warn_setter_getter_impl_required_in_category :
1639                diag::warn_setter_getter_impl_required)
1640             << Prop->getDeclName() << Method;
1641         S.Diag(Prop->getLocation(),
1642              diag::note_property_declare);
1643         if (S.LangOpts.ObjCDefaultSynthProperties &&
1644             S.LangOpts.ObjCRuntime.isNonFragile())
1645           if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1646             if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1647             S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1648       }
1649 }
1650 
1651 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1652                                            ObjCContainerDecl *CDecl,
1653                                            bool SynthesizeProperties) {
1654   ObjCContainerDecl::PropertyMap PropMap;
1655   ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
1656 
1657   if (!SynthesizeProperties) {
1658     ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1659     // Gather properties which need not be implemented in this class
1660     // or category.
1661     if (!IDecl)
1662       if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1663         // For categories, no need to implement properties declared in
1664         // its primary class (and its super classes) if property is
1665         // declared in one of those containers.
1666         if ((IDecl = C->getClassInterface())) {
1667           ObjCInterfaceDecl::PropertyDeclOrder PO;
1668           IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
1669         }
1670       }
1671     if (IDecl)
1672       CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
1673 
1674     CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap);
1675   }
1676 
1677   // Scan the @interface to see if any of the protocols it adopts
1678   // require an explicit implementation, via attribute
1679   // 'objc_protocol_requires_explicit_implementation'.
1680   if (IDecl) {
1681     std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
1682 
1683     for (auto *PDecl : IDecl->all_referenced_protocols()) {
1684       if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
1685         continue;
1686       // Lazily construct a set of all the properties in the @interface
1687       // of the class, without looking at the superclass.  We cannot
1688       // use the call to CollectImmediateProperties() above as that
1689       // utilizes information from the super class's properties as well
1690       // as scans the adopted protocols.  This work only triggers for protocols
1691       // with the attribute, which is very rare, and only occurs when
1692       // analyzing the @implementation.
1693       if (!LazyMap) {
1694         ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1695         LazyMap.reset(new ObjCContainerDecl::PropertyMap());
1696         CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
1697                                    /* IncludeProtocols */ false);
1698       }
1699       // Add the properties of 'PDecl' to the list of properties that
1700       // need to be implemented.
1701       for (auto *PropDecl : PDecl->properties()) {
1702         if ((*LazyMap)[PropDecl->getIdentifier()])
1703           continue;
1704         PropMap[PropDecl->getIdentifier()] = PropDecl;
1705       }
1706     }
1707   }
1708 
1709   if (PropMap.empty())
1710     return;
1711 
1712   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
1713   for (const auto *I : IMPDecl->property_impls())
1714     PropImplMap.insert(I->getPropertyDecl());
1715 
1716   SelectorSet InsMap;
1717   // Collect property accessors implemented in current implementation.
1718   for (const auto *I : IMPDecl->instance_methods())
1719     InsMap.insert(I->getSelector());
1720 
1721   ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
1722   ObjCInterfaceDecl *PrimaryClass = nullptr;
1723   if (C && !C->IsClassExtension())
1724     if ((PrimaryClass = C->getClassInterface()))
1725       // Report unimplemented properties in the category as well.
1726       if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
1727         // When reporting on missing setter/getters, do not report when
1728         // setter/getter is implemented in category's primary class
1729         // implementation.
1730         for (const auto *I : IMP->instance_methods())
1731           InsMap.insert(I->getSelector());
1732       }
1733 
1734   for (ObjCContainerDecl::PropertyMap::iterator
1735        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
1736     ObjCPropertyDecl *Prop = P->second;
1737     // Is there a matching propery synthesize/dynamic?
1738     if (Prop->isInvalidDecl() ||
1739         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
1740         PropImplMap.count(Prop) ||
1741         Prop->getAvailability() == AR_Unavailable)
1742       continue;
1743 
1744     // Diagnose unimplemented getters and setters.
1745     DiagnoseUnimplementedAccessor(*this,
1746           PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
1747     if (!Prop->isReadOnly())
1748       DiagnoseUnimplementedAccessor(*this,
1749                                     PrimaryClass, Prop->getSetterName(),
1750                                     IMPDecl, CDecl, C, Prop, InsMap);
1751   }
1752 }
1753 
1754 void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
1755   for (const auto *propertyImpl : impDecl->property_impls()) {
1756     const auto *property = propertyImpl->getPropertyDecl();
1757 
1758     // Warn about null_resettable properties with synthesized setters,
1759     // because the setter won't properly handle nil.
1760     if (propertyImpl->getPropertyImplementation()
1761           == ObjCPropertyImplDecl::Synthesize &&
1762         (property->getPropertyAttributes() &
1763          ObjCPropertyDecl::OBJC_PR_null_resettable) &&
1764         property->getGetterMethodDecl() &&
1765         property->getSetterMethodDecl()) {
1766       auto *getterMethod = property->getGetterMethodDecl();
1767       auto *setterMethod = property->getSetterMethodDecl();
1768       if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
1769           !impDecl->getInstanceMethod(getterMethod->getSelector())) {
1770         SourceLocation loc = propertyImpl->getLocation();
1771         if (loc.isInvalid())
1772           loc = impDecl->getLocStart();
1773 
1774         Diag(loc, diag::warn_null_resettable_setter)
1775           << setterMethod->getSelector() << property->getDeclName();
1776       }
1777     }
1778   }
1779 }
1780 
1781 void
1782 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
1783                                        ObjCInterfaceDecl* IDecl) {
1784   // Rules apply in non-GC mode only
1785   if (getLangOpts().getGC() != LangOptions::NonGC)
1786     return;
1787   ObjCContainerDecl::PropertyMap PM;
1788   for (auto *Prop : IDecl->properties())
1789     PM[Prop->getIdentifier()] = Prop;
1790   for (const auto *Ext : IDecl->known_extensions())
1791     for (auto *Prop : Ext->properties())
1792       PM[Prop->getIdentifier()] = Prop;
1793 
1794     for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
1795          I != E; ++I) {
1796     const ObjCPropertyDecl *Property = I->second;
1797     ObjCMethodDecl *GetterMethod = nullptr;
1798     ObjCMethodDecl *SetterMethod = nullptr;
1799     bool LookedUpGetterSetter = false;
1800 
1801     unsigned Attributes = Property->getPropertyAttributes();
1802     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
1803 
1804     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
1805         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
1806       GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1807       SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1808       LookedUpGetterSetter = true;
1809       if (GetterMethod) {
1810         Diag(GetterMethod->getLocation(),
1811              diag::warn_default_atomic_custom_getter_setter)
1812           << Property->getIdentifier() << 0;
1813         Diag(Property->getLocation(), diag::note_property_declare);
1814       }
1815       if (SetterMethod) {
1816         Diag(SetterMethod->getLocation(),
1817              diag::warn_default_atomic_custom_getter_setter)
1818           << Property->getIdentifier() << 1;
1819         Diag(Property->getLocation(), diag::note_property_declare);
1820       }
1821     }
1822 
1823     // We only care about readwrite atomic property.
1824     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
1825         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
1826       continue;
1827     if (const ObjCPropertyImplDecl *PIDecl
1828          = IMPDecl->FindPropertyImplDecl(Property->getIdentifier())) {
1829       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
1830         continue;
1831       if (!LookedUpGetterSetter) {
1832         GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1833         SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1834       }
1835       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
1836         SourceLocation MethodLoc =
1837           (GetterMethod ? GetterMethod->getLocation()
1838                         : SetterMethod->getLocation());
1839         Diag(MethodLoc, diag::warn_atomic_property_rule)
1840           << Property->getIdentifier() << (GetterMethod != nullptr)
1841           << (SetterMethod != nullptr);
1842         // fixit stuff.
1843         if (Property->getLParenLoc().isValid() &&
1844             !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
1845           // @property () ... case.
1846           SourceLocation AfterLParen =
1847             getLocForEndOfToken(Property->getLParenLoc());
1848           StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
1849                                                       : "nonatomic";
1850           Diag(Property->getLocation(),
1851                diag::note_atomic_property_fixup_suggest)
1852             << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
1853         } else if (Property->getLParenLoc().isInvalid()) {
1854           //@property id etc.
1855           SourceLocation startLoc =
1856             Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
1857           Diag(Property->getLocation(),
1858                diag::note_atomic_property_fixup_suggest)
1859             << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
1860         }
1861         else
1862           Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
1863         Diag(Property->getLocation(), diag::note_property_declare);
1864       }
1865     }
1866   }
1867 }
1868 
1869 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
1870   if (getLangOpts().getGC() == LangOptions::GCOnly)
1871     return;
1872 
1873   for (const auto *PID : D->property_impls()) {
1874     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
1875     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
1876         !D->getInstanceMethod(PD->getGetterName())) {
1877       ObjCMethodDecl *method = PD->getGetterMethodDecl();
1878       if (!method)
1879         continue;
1880       ObjCMethodFamily family = method->getMethodFamily();
1881       if (family == OMF_alloc || family == OMF_copy ||
1882           family == OMF_mutableCopy || family == OMF_new) {
1883         if (getLangOpts().ObjCAutoRefCount)
1884           Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
1885         else
1886           Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
1887 
1888         // Look for a getter explicitly declared alongside the property.
1889         // If we find one, use its location for the note.
1890         SourceLocation noteLoc = PD->getLocation();
1891         SourceLocation fixItLoc;
1892         for (auto *getterRedecl : method->redecls()) {
1893           if (getterRedecl->isImplicit())
1894             continue;
1895           if (getterRedecl->getDeclContext() != PD->getDeclContext())
1896             continue;
1897           noteLoc = getterRedecl->getLocation();
1898           fixItLoc = getterRedecl->getLocEnd();
1899         }
1900 
1901         Preprocessor &PP = getPreprocessor();
1902         TokenValue tokens[] = {
1903           tok::kw___attribute, tok::l_paren, tok::l_paren,
1904           PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
1905           PP.getIdentifierInfo("none"), tok::r_paren,
1906           tok::r_paren, tok::r_paren
1907         };
1908         StringRef spelling = "__attribute__((objc_method_family(none)))";
1909         StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
1910         if (!macroName.empty())
1911           spelling = macroName;
1912 
1913         auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
1914             << method->getDeclName() << spelling;
1915         if (fixItLoc.isValid()) {
1916           SmallString<64> fixItText(" ");
1917           fixItText += spelling;
1918           noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
1919         }
1920       }
1921     }
1922   }
1923 }
1924 
1925 void Sema::DiagnoseMissingDesignatedInitOverrides(
1926                                             const ObjCImplementationDecl *ImplD,
1927                                             const ObjCInterfaceDecl *IFD) {
1928   assert(IFD->hasDesignatedInitializers());
1929   const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
1930   if (!SuperD)
1931     return;
1932 
1933   SelectorSet InitSelSet;
1934   for (const auto *I : ImplD->instance_methods())
1935     if (I->getMethodFamily() == OMF_init)
1936       InitSelSet.insert(I->getSelector());
1937 
1938   SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
1939   SuperD->getDesignatedInitializers(DesignatedInits);
1940   for (SmallVector<const ObjCMethodDecl *, 8>::iterator
1941          I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
1942     const ObjCMethodDecl *MD = *I;
1943     if (!InitSelSet.count(MD->getSelector())) {
1944       bool Ignore = false;
1945       if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
1946         Ignore = IMD->isUnavailable();
1947       }
1948       if (!Ignore) {
1949         Diag(ImplD->getLocation(),
1950              diag::warn_objc_implementation_missing_designated_init_override)
1951           << MD->getSelector();
1952         Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
1953       }
1954     }
1955   }
1956 }
1957 
1958 /// AddPropertyAttrs - Propagates attributes from a property to the
1959 /// implicitly-declared getter or setter for that property.
1960 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
1961                              ObjCPropertyDecl *Property) {
1962   // Should we just clone all attributes over?
1963   for (const auto *A : Property->attrs()) {
1964     if (isa<DeprecatedAttr>(A) ||
1965         isa<UnavailableAttr>(A) ||
1966         isa<AvailabilityAttr>(A))
1967       PropertyMethod->addAttr(A->clone(S.Context));
1968   }
1969 }
1970 
1971 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
1972 /// have the property type and issue diagnostics if they don't.
1973 /// Also synthesize a getter/setter method if none exist (and update the
1974 /// appropriate lookup tables.
1975 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
1976   ObjCMethodDecl *GetterMethod, *SetterMethod;
1977   ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
1978   if (CD->isInvalidDecl())
1979     return;
1980 
1981   GetterMethod = CD->getInstanceMethod(property->getGetterName());
1982   // if setter or getter is not found in class extension, it might be
1983   // in the primary class.
1984   if (!GetterMethod)
1985     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
1986       if (CatDecl->IsClassExtension())
1987         GetterMethod = CatDecl->getClassInterface()->
1988                          getInstanceMethod(property->getGetterName());
1989 
1990   SetterMethod = CD->getInstanceMethod(property->getSetterName());
1991   if (!SetterMethod)
1992     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
1993       if (CatDecl->IsClassExtension())
1994         SetterMethod = CatDecl->getClassInterface()->
1995                           getInstanceMethod(property->getSetterName());
1996   DiagnosePropertyAccessorMismatch(property, GetterMethod,
1997                                    property->getLocation());
1998 
1999   if (SetterMethod) {
2000     ObjCPropertyDecl::PropertyAttributeKind CAttr =
2001       property->getPropertyAttributes();
2002     if ((!(CAttr & ObjCPropertyDecl::OBJC_PR_readonly)) &&
2003         Context.getCanonicalType(SetterMethod->getReturnType()) !=
2004             Context.VoidTy)
2005       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2006     if (SetterMethod->param_size() != 1 ||
2007         !Context.hasSameUnqualifiedType(
2008           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2009           property->getType().getNonReferenceType())) {
2010       Diag(property->getLocation(),
2011            diag::warn_accessor_property_type_mismatch)
2012         << property->getDeclName()
2013         << SetterMethod->getSelector();
2014       Diag(SetterMethod->getLocation(), diag::note_declared_at);
2015     }
2016   }
2017 
2018   // Synthesize getter/setter methods if none exist.
2019   // Find the default getter and if one not found, add one.
2020   // FIXME: The synthesized property we set here is misleading. We almost always
2021   // synthesize these methods unless the user explicitly provided prototypes
2022   // (which is odd, but allowed). Sema should be typechecking that the
2023   // declarations jive in that situation (which it is not currently).
2024   if (!GetterMethod) {
2025     // No instance method of same name as property getter name was found.
2026     // Declare a getter method and add it to the list of methods
2027     // for this class.
2028     SourceLocation Loc = property->getLocation();
2029 
2030     // If the property is null_resettable, the getter returns nonnull.
2031     QualType resultTy = property->getType();
2032     if (property->getPropertyAttributes() &
2033         ObjCPropertyDecl::OBJC_PR_null_resettable) {
2034       QualType modifiedTy = resultTy;
2035       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
2036         if (*nullability == NullabilityKind::Unspecified)
2037           resultTy = Context.getAttributedType(AttributedType::attr_nonnull,
2038                                                modifiedTy, modifiedTy);
2039       }
2040     }
2041 
2042     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
2043                              property->getGetterName(),
2044                              resultTy, nullptr, CD,
2045                              /*isInstance=*/true, /*isVariadic=*/false,
2046                              /*isPropertyAccessor=*/true,
2047                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2048                              (property->getPropertyImplementation() ==
2049                               ObjCPropertyDecl::Optional) ?
2050                              ObjCMethodDecl::Optional :
2051                              ObjCMethodDecl::Required);
2052     CD->addDecl(GetterMethod);
2053 
2054     AddPropertyAttrs(*this, GetterMethod, property);
2055 
2056     if (property->hasAttr<NSReturnsNotRetainedAttr>())
2057       GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2058                                                                      Loc));
2059 
2060     if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2061       GetterMethod->addAttr(
2062         ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2063 
2064     if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2065       GetterMethod->addAttr(
2066           SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2067                                       SA->getName(), Loc));
2068 
2069     if (getLangOpts().ObjCAutoRefCount)
2070       CheckARCMethodDecl(GetterMethod);
2071   } else
2072     // A user declared getter will be synthesize when @synthesize of
2073     // the property with the same name is seen in the @implementation
2074     GetterMethod->setPropertyAccessor(true);
2075   property->setGetterMethodDecl(GetterMethod);
2076 
2077   // Skip setter if property is read-only.
2078   if (!property->isReadOnly()) {
2079     // Find the default setter and if one not found, add one.
2080     if (!SetterMethod) {
2081       // No instance method of same name as property setter name was found.
2082       // Declare a setter method and add it to the list of methods
2083       // for this class.
2084       SourceLocation Loc = property->getLocation();
2085 
2086       SetterMethod =
2087         ObjCMethodDecl::Create(Context, Loc, Loc,
2088                                property->getSetterName(), Context.VoidTy,
2089                                nullptr, CD, /*isInstance=*/true,
2090                                /*isVariadic=*/false,
2091                                /*isPropertyAccessor=*/true,
2092                                /*isImplicitlyDeclared=*/true,
2093                                /*isDefined=*/false,
2094                                (property->getPropertyImplementation() ==
2095                                 ObjCPropertyDecl::Optional) ?
2096                                 ObjCMethodDecl::Optional :
2097                                 ObjCMethodDecl::Required);
2098 
2099       // If the property is null_resettable, the setter accepts a
2100       // nullable value.
2101       QualType paramTy = property->getType().getUnqualifiedType();
2102       if (property->getPropertyAttributes() &
2103           ObjCPropertyDecl::OBJC_PR_null_resettable) {
2104         QualType modifiedTy = paramTy;
2105         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2106           if (*nullability == NullabilityKind::Unspecified)
2107             paramTy = Context.getAttributedType(AttributedType::attr_nullable,
2108                                                 modifiedTy, modifiedTy);
2109         }
2110       }
2111 
2112       // Invent the arguments for the setter. We don't bother making a
2113       // nice name for the argument.
2114       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2115                                                   Loc, Loc,
2116                                                   property->getIdentifier(),
2117                                                   paramTy,
2118                                                   /*TInfo=*/nullptr,
2119                                                   SC_None,
2120                                                   nullptr);
2121       SetterMethod->setMethodParams(Context, Argument, None);
2122 
2123       AddPropertyAttrs(*this, SetterMethod, property);
2124 
2125       CD->addDecl(SetterMethod);
2126       if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2127         SetterMethod->addAttr(
2128             SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2129                                         SA->getName(), Loc));
2130       // It's possible for the user to have set a very odd custom
2131       // setter selector that causes it to have a method family.
2132       if (getLangOpts().ObjCAutoRefCount)
2133         CheckARCMethodDecl(SetterMethod);
2134     } else
2135       // A user declared setter will be synthesize when @synthesize of
2136       // the property with the same name is seen in the @implementation
2137       SetterMethod->setPropertyAccessor(true);
2138     property->setSetterMethodDecl(SetterMethod);
2139   }
2140   // Add any synthesized methods to the global pool. This allows us to
2141   // handle the following, which is supported by GCC (and part of the design).
2142   //
2143   // @interface Foo
2144   // @property double bar;
2145   // @end
2146   //
2147   // void thisIsUnfortunate() {
2148   //   id foo;
2149   //   double bar = [foo bar];
2150   // }
2151   //
2152   if (GetterMethod)
2153     AddInstanceMethodToGlobalPool(GetterMethod);
2154   if (SetterMethod)
2155     AddInstanceMethodToGlobalPool(SetterMethod);
2156 
2157   ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2158   if (!CurrentClass) {
2159     if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2160       CurrentClass = Cat->getClassInterface();
2161     else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2162       CurrentClass = Impl->getClassInterface();
2163   }
2164   if (GetterMethod)
2165     CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2166   if (SetterMethod)
2167     CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2168 }
2169 
2170 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2171                                        SourceLocation Loc,
2172                                        unsigned &Attributes,
2173                                        bool propertyInPrimaryClass) {
2174   // FIXME: Improve the reported location.
2175   if (!PDecl || PDecl->isInvalidDecl())
2176     return;
2177 
2178   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2179       (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
2180     Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2181     << "readonly" << "readwrite";
2182 
2183   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2184   QualType PropertyTy = PropertyDecl->getType();
2185 
2186   // Check for copy or retain on non-object types.
2187   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
2188                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
2189       !PropertyTy->isObjCRetainableType() &&
2190       !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2191     Diag(Loc, diag::err_objc_property_requires_object)
2192       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
2193           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
2194     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
2195                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
2196     PropertyDecl->setInvalidDecl();
2197   }
2198 
2199   // Check for more than one of { assign, copy, retain }.
2200   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
2201     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2202       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2203         << "assign" << "copy";
2204       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2205     }
2206     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2207       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2208         << "assign" << "retain";
2209       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2210     }
2211     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2212       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2213         << "assign" << "strong";
2214       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2215     }
2216     if (getLangOpts().ObjCAutoRefCount  &&
2217         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2218       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2219         << "assign" << "weak";
2220       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2221     }
2222     if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2223       Diag(Loc, diag::warn_iboutletcollection_property_assign);
2224   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
2225     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2226       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2227         << "unsafe_unretained" << "copy";
2228       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2229     }
2230     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2231       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2232         << "unsafe_unretained" << "retain";
2233       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2234     }
2235     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2236       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2237         << "unsafe_unretained" << "strong";
2238       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2239     }
2240     if (getLangOpts().ObjCAutoRefCount  &&
2241         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2242       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2243         << "unsafe_unretained" << "weak";
2244       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2245     }
2246   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2247     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2248       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2249         << "copy" << "retain";
2250       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2251     }
2252     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2253       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2254         << "copy" << "strong";
2255       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2256     }
2257     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2258       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2259         << "copy" << "weak";
2260       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2261     }
2262   }
2263   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2264            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2265       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2266         << "retain" << "weak";
2267       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2268   }
2269   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2270            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2271       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2272         << "strong" << "weak";
2273       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2274   }
2275 
2276   if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2277     // 'weak' and 'nonnull' are mutually exclusive.
2278     if (auto nullability = PropertyTy->getNullability(Context)) {
2279       if (*nullability == NullabilityKind::NonNull)
2280         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2281           << "nonnull" << "weak";
2282     }
2283   }
2284 
2285   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
2286       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
2287       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2288         << "atomic" << "nonatomic";
2289       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
2290   }
2291 
2292   // Warn if user supplied no assignment attribute, property is
2293   // readwrite, and this is an object type.
2294   if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
2295     if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
2296       // do nothing
2297     } else if (getLangOpts().ObjCAutoRefCount) {
2298       // With arc, @property definitions should default to strong when
2299       // not specified.
2300       PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
2301     } else if (PropertyTy->isObjCObjectPointerType()) {
2302         bool isAnyClassTy =
2303           (PropertyTy->isObjCClassType() ||
2304            PropertyTy->isObjCQualifiedClassType());
2305         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2306         // issue any warning.
2307         if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2308           ;
2309         else if (propertyInPrimaryClass) {
2310           // Don't issue warning on property with no life time in class
2311           // extension as it is inherited from property in primary class.
2312           // Skip this warning in gc-only mode.
2313           if (getLangOpts().getGC() != LangOptions::GCOnly)
2314             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2315 
2316           // If non-gc code warn that this is likely inappropriate.
2317           if (getLangOpts().getGC() == LangOptions::NonGC)
2318             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2319         }
2320     }
2321 
2322     // FIXME: Implement warning dependent on NSCopying being
2323     // implemented. See also:
2324     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2325     // (please trim this list while you are at it).
2326   }
2327 
2328   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
2329       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
2330       && getLangOpts().getGC() == LangOptions::GCOnly
2331       && PropertyTy->isBlockPointerType())
2332     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2333   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2334            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2335            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2336            PropertyTy->isBlockPointerType())
2337       Diag(Loc, diag::warn_objc_property_retain_of_block);
2338 
2339   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2340       (Attributes & ObjCDeclSpec::DQ_PR_setter))
2341     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2342 
2343 }
2344