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.
65 static void checkARCPropertyDecl(Sema &S, ObjCPropertyDecl *property) {
66   if (property->isInvalidDecl()) return;
67 
68   ObjCPropertyDecl::PropertyAttributeKind propertyKind
69     = property->getPropertyAttributes();
70   Qualifiers::ObjCLifetime propertyLifetime
71     = property->getType().getObjCLifetime();
72 
73   // Nothing to do if we don't have a lifetime.
74   if (propertyLifetime == Qualifiers::OCL_None) return;
75 
76   Qualifiers::ObjCLifetime expectedLifetime
77     = getImpliedARCOwnership(propertyKind, property->getType());
78   if (!expectedLifetime) {
79     // We have a lifetime qualifier but no dominating property
80     // attribute.  That's okay, but restore reasonable invariants by
81     // setting the property attribute according to the lifetime
82     // qualifier.
83     ObjCPropertyDecl::PropertyAttributeKind attr;
84     if (propertyLifetime == Qualifiers::OCL_Strong) {
85       attr = ObjCPropertyDecl::OBJC_PR_strong;
86     } else if (propertyLifetime == Qualifiers::OCL_Weak) {
87       attr = ObjCPropertyDecl::OBJC_PR_weak;
88     } else {
89       assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
90       attr = ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
91     }
92     property->setPropertyAttributes(attr);
93     return;
94   }
95 
96   if (propertyLifetime == expectedLifetime) return;
97 
98   property->setInvalidDecl();
99   S.Diag(property->getLocation(),
100          diag::err_arc_inconsistent_property_ownership)
101     << property->getDeclName()
102     << expectedLifetime
103     << propertyLifetime;
104 }
105 
106 /// \brief Check this Objective-C property against a property declared in the
107 /// given protocol.
108 static void
109 CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
110                              ObjCProtocolDecl *Proto,
111                              llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
112   // Have we seen this protocol before?
113   if (!Known.insert(Proto).second)
114     return;
115 
116   // Look for a property with the same name.
117   DeclContext::lookup_result R = Proto->lookup(Prop->getDeclName());
118   for (unsigned I = 0, N = R.size(); I != N; ++I) {
119     if (ObjCPropertyDecl *ProtoProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
120       S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
121       return;
122     }
123   }
124 
125   // Check this property against any protocols we inherit.
126   for (auto *P : Proto->protocols())
127     CheckPropertyAgainstProtocol(S, Prop, P, Known);
128 }
129 
130 Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
131                           SourceLocation LParenLoc,
132                           FieldDeclarator &FD,
133                           ObjCDeclSpec &ODS,
134                           Selector GetterSel,
135                           Selector SetterSel,
136                           bool *isOverridingProperty,
137                           tok::ObjCKeywordKind MethodImplKind,
138                           DeclContext *lexicalDC) {
139   unsigned Attributes = ODS.getPropertyAttributes();
140   FD.D.setObjCWeakProperty((Attributes & ObjCDeclSpec::DQ_PR_weak) != 0);
141   TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
142   QualType T = TSI->getType();
143   Attributes |= deduceWeakPropertyFromType(T);
144   bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
145                       // default is readwrite!
146                       !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
147   // property is defaulted to 'assign' if it is readwrite and is
148   // not retain or copy
149   bool isAssign = ((Attributes & ObjCDeclSpec::DQ_PR_assign) ||
150                    (isReadWrite &&
151                     !(Attributes & ObjCDeclSpec::DQ_PR_retain) &&
152                     !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
153                     !(Attributes & ObjCDeclSpec::DQ_PR_copy) &&
154                     !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
155                     !(Attributes & ObjCDeclSpec::DQ_PR_weak)));
156 
157   // Proceed with constructing the ObjCPropertyDecls.
158   ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
159   ObjCPropertyDecl *Res = nullptr;
160   if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
161     if (CDecl->IsClassExtension()) {
162       Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
163                                            FD, GetterSel, SetterSel,
164                                            isAssign, isReadWrite,
165                                            Attributes,
166                                            ODS.getPropertyAttributes(),
167                                            isOverridingProperty, T, TSI,
168                                            MethodImplKind);
169       if (!Res)
170         return nullptr;
171     }
172   }
173 
174   if (!Res) {
175     Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
176                              GetterSel, SetterSel, isAssign, isReadWrite,
177                              Attributes, ODS.getPropertyAttributes(),
178                              T, TSI, MethodImplKind);
179     if (lexicalDC)
180       Res->setLexicalDeclContext(lexicalDC);
181   }
182 
183   // Validate the attributes on the @property.
184   CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
185                               (isa<ObjCInterfaceDecl>(ClassDecl) ||
186                                isa<ObjCProtocolDecl>(ClassDecl)));
187 
188   if (getLangOpts().ObjCAutoRefCount)
189     checkARCPropertyDecl(*this, Res);
190 
191   llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
192   if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
193     // For a class, compare the property against a property in our superclass.
194     bool FoundInSuper = false;
195     ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
196     while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
197       DeclContext::lookup_result R = Super->lookup(Res->getDeclName());
198       for (unsigned I = 0, N = R.size(); I != N; ++I) {
199         if (ObjCPropertyDecl *SuperProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
200           DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
201           FoundInSuper = true;
202           break;
203         }
204       }
205       if (FoundInSuper)
206         break;
207       else
208         CurrentInterfaceDecl = Super;
209     }
210 
211     if (FoundInSuper) {
212       // Also compare the property against a property in our protocols.
213       for (auto *P : CurrentInterfaceDecl->protocols()) {
214         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
215       }
216     } else {
217       // Slower path: look in all protocols we referenced.
218       for (auto *P : IFace->all_referenced_protocols()) {
219         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
220       }
221     }
222   } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
223     for (auto *P : Cat->protocols())
224       CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
225   } else {
226     ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
227     for (auto *P : Proto->protocols())
228       CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
229   }
230 
231   ActOnDocumentableDecl(Res);
232   return Res;
233 }
234 
235 static ObjCPropertyDecl::PropertyAttributeKind
236 makePropertyAttributesAsWritten(unsigned Attributes) {
237   unsigned attributesAsWritten = 0;
238   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
239     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
240   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
241     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
242   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
243     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
244   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
245     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
246   if (Attributes & ObjCDeclSpec::DQ_PR_assign)
247     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
248   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
249     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
250   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
251     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
252   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
253     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
254   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
255     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
256   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
257     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
258   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
259     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
260   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
261     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
262 
263   return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
264 }
265 
266 static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
267                                  SourceLocation LParenLoc, SourceLocation &Loc) {
268   if (LParenLoc.isMacroID())
269     return false;
270 
271   SourceManager &SM = Context.getSourceManager();
272   std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
273   // Try to load the file buffer.
274   bool invalidTemp = false;
275   StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
276   if (invalidTemp)
277     return false;
278   const char *tokenBegin = file.data() + locInfo.second;
279 
280   // Lex from the start of the given location.
281   Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
282               Context.getLangOpts(),
283               file.begin(), tokenBegin, file.end());
284   Token Tok;
285   do {
286     lexer.LexFromRawLexer(Tok);
287     if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
288       Loc = Tok.getLocation();
289       return true;
290     }
291   } while (Tok.isNot(tok::r_paren));
292   return false;
293 
294 }
295 
296 static unsigned getOwnershipRule(unsigned attr) {
297   return attr & (ObjCPropertyDecl::OBJC_PR_assign |
298                  ObjCPropertyDecl::OBJC_PR_retain |
299                  ObjCPropertyDecl::OBJC_PR_copy   |
300                  ObjCPropertyDecl::OBJC_PR_weak   |
301                  ObjCPropertyDecl::OBJC_PR_strong |
302                  ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
303 }
304 
305 ObjCPropertyDecl *
306 Sema::HandlePropertyInClassExtension(Scope *S,
307                                      SourceLocation AtLoc,
308                                      SourceLocation LParenLoc,
309                                      FieldDeclarator &FD,
310                                      Selector GetterSel, Selector SetterSel,
311                                      const bool isAssign,
312                                      const bool isReadWrite,
313                                      const unsigned Attributes,
314                                      const unsigned AttributesAsWritten,
315                                      bool *isOverridingProperty,
316                                      QualType T,
317                                      TypeSourceInfo *TSI,
318                                      tok::ObjCKeywordKind MethodImplKind) {
319   ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
320   // Diagnose if this property is already in continuation class.
321   DeclContext *DC = CurContext;
322   IdentifierInfo *PropertyId = FD.D.getIdentifier();
323   ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
324 
325   if (CCPrimary) {
326     // Check for duplicate declaration of this property in current and
327     // other class extensions.
328     for (const auto *Ext : CCPrimary->known_extensions()) {
329       if (ObjCPropertyDecl *prevDecl
330             = ObjCPropertyDecl::findPropertyDecl(Ext, PropertyId)) {
331         Diag(AtLoc, diag::err_duplicate_property);
332         Diag(prevDecl->getLocation(), diag::note_property_declare);
333         return nullptr;
334       }
335     }
336   }
337 
338   // Create a new ObjCPropertyDecl with the DeclContext being
339   // the class extension.
340   // FIXME. We should really be using CreatePropertyDecl for this.
341   ObjCPropertyDecl *PDecl =
342     ObjCPropertyDecl::Create(Context, DC, FD.D.getIdentifierLoc(),
343                              PropertyId, AtLoc, LParenLoc, T, TSI);
344   PDecl->setPropertyAttributesAsWritten(
345                           makePropertyAttributesAsWritten(AttributesAsWritten));
346   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
347     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
348   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
349     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
350   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
351     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
352   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
353     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
354   if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
355     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
356   if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
357     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
358 
359   // Set setter/getter selector name. Needed later.
360   PDecl->setGetterName(GetterSel);
361   PDecl->setSetterName(SetterSel);
362   ProcessDeclAttributes(S, PDecl, FD.D);
363   DC->addDecl(PDecl);
364 
365   // We need to look in the @interface to see if the @property was
366   // already declared.
367   if (!CCPrimary) {
368     Diag(CDecl->getLocation(), diag::err_continuation_class);
369     *isOverridingProperty = true;
370     return nullptr;
371   }
372 
373   // Find the property in continuation class's primary class only.
374   ObjCPropertyDecl *PIDecl =
375     CCPrimary->FindPropertyVisibleInPrimaryClass(PropertyId);
376 
377   if (!PIDecl) {
378     // No matching property found in the primary class. Just fall thru
379     // and add property to continuation class's primary class.
380     ObjCPropertyDecl *PrimaryPDecl =
381       CreatePropertyDecl(S, CCPrimary, AtLoc, LParenLoc,
382                          FD, GetterSel, SetterSel, isAssign, isReadWrite,
383                          Attributes,AttributesAsWritten, T, TSI, MethodImplKind,
384                          DC);
385 
386     // A case of continuation class adding a new property in the class. This
387     // is not what it was meant for. However, gcc supports it and so should we.
388     // Make sure setter/getters are declared here.
389     ProcessPropertyDecl(PrimaryPDecl, CCPrimary,
390                         /* redeclaredProperty = */ nullptr,
391                         /* lexicalDC = */ CDecl);
392     PDecl->setGetterMethodDecl(PrimaryPDecl->getGetterMethodDecl());
393     PDecl->setSetterMethodDecl(PrimaryPDecl->getSetterMethodDecl());
394     if (ASTMutationListener *L = Context.getASTMutationListener())
395       L->AddedObjCPropertyInClassExtension(PrimaryPDecl, /*OrigProp=*/nullptr,
396                                            CDecl);
397     return PrimaryPDecl;
398   }
399   if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
400     bool IncompatibleObjC = false;
401     QualType ConvertedType;
402     // Relax the strict type matching for property type in continuation class.
403     // Allow property object type of continuation class to be different as long
404     // as it narrows the object type in its primary class property. Note that
405     // this conversion is safe only because the wider type is for a 'readonly'
406     // property in primary class and 'narrowed' type for a 'readwrite' property
407     // in continuation class.
408     QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
409     QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
410     if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
411         !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
412         (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
413                                   ConvertedType, IncompatibleObjC))
414         || IncompatibleObjC) {
415       Diag(AtLoc,
416           diag::err_type_mismatch_continuation_class) << PDecl->getType();
417       Diag(PIDecl->getLocation(), diag::note_property_declare);
418       return nullptr;
419     }
420   }
421 
422   // The property 'PIDecl's readonly attribute will be over-ridden
423   // with continuation class's readwrite property attribute!
424   unsigned PIkind = PIDecl->getPropertyAttributesAsWritten();
425   if (isReadWrite && (PIkind & ObjCPropertyDecl::OBJC_PR_readonly)) {
426     PIkind &= ~ObjCPropertyDecl::OBJC_PR_readonly;
427     PIkind |= ObjCPropertyDecl::OBJC_PR_readwrite;
428     PIkind |= deduceWeakPropertyFromType(PIDecl->getType());
429     unsigned ClassExtensionMemoryModel = getOwnershipRule(Attributes);
430     unsigned PrimaryClassMemoryModel = getOwnershipRule(PIkind);
431     if (PrimaryClassMemoryModel && ClassExtensionMemoryModel &&
432         (PrimaryClassMemoryModel != ClassExtensionMemoryModel)) {
433       Diag(AtLoc, diag::warn_property_attr_mismatch);
434       Diag(PIDecl->getLocation(), diag::note_property_declare);
435     }
436     else if (getLangOpts().ObjCAutoRefCount) {
437       QualType PrimaryPropertyQT =
438         Context.getCanonicalType(PIDecl->getType()).getUnqualifiedType();
439       if (isa<ObjCObjectPointerType>(PrimaryPropertyQT)) {
440         bool PropertyIsWeak = ((PIkind & ObjCPropertyDecl::OBJC_PR_weak) != 0);
441         Qualifiers::ObjCLifetime PrimaryPropertyLifeTime =
442           PrimaryPropertyQT.getObjCLifetime();
443         if (PrimaryPropertyLifeTime == Qualifiers::OCL_None &&
444             (Attributes & ObjCDeclSpec::DQ_PR_weak) &&
445             !PropertyIsWeak) {
446               Diag(AtLoc, diag::warn_property_implicitly_mismatched);
447               Diag(PIDecl->getLocation(), diag::note_property_declare);
448             }
449         }
450     }
451 
452     DeclContext *DC = cast<DeclContext>(CCPrimary);
453     if (!ObjCPropertyDecl::findPropertyDecl(DC,
454                                  PIDecl->getDeclName().getAsIdentifierInfo())) {
455       // In mrr mode, 'readwrite' property must have an explicit
456       // memory attribute. If none specified, select the default (assign).
457       if (!getLangOpts().ObjCAutoRefCount) {
458         if (!(PIkind & (ObjCDeclSpec::DQ_PR_assign |
459                         ObjCDeclSpec::DQ_PR_retain |
460                         ObjCDeclSpec::DQ_PR_strong |
461                         ObjCDeclSpec::DQ_PR_copy |
462                         ObjCDeclSpec::DQ_PR_unsafe_unretained |
463                         ObjCDeclSpec::DQ_PR_weak)))
464           PIkind |= ObjCPropertyDecl::OBJC_PR_assign;
465       }
466 
467       // Protocol is not in the primary class. Must build one for it.
468       ObjCDeclSpec ProtocolPropertyODS;
469       // FIXME. Assuming that ObjCDeclSpec::ObjCPropertyAttributeKind
470       // and ObjCPropertyDecl::PropertyAttributeKind have identical
471       // values.  Should consolidate both into one enum type.
472       ProtocolPropertyODS.
473       setPropertyAttributes((ObjCDeclSpec::ObjCPropertyAttributeKind)
474                             PIkind);
475       // Must re-establish the context from class extension to primary
476       // class context.
477       ContextRAII SavedContext(*this, CCPrimary);
478 
479       Decl *ProtocolPtrTy =
480         ActOnProperty(S, AtLoc, LParenLoc, FD, ProtocolPropertyODS,
481                       PIDecl->getGetterName(),
482                       PIDecl->getSetterName(),
483                       isOverridingProperty,
484                       MethodImplKind,
485                       /* lexicalDC = */ CDecl);
486       PIDecl = cast<ObjCPropertyDecl>(ProtocolPtrTy);
487     }
488     PIDecl->makeitReadWriteAttribute();
489     if (Attributes & ObjCDeclSpec::DQ_PR_retain)
490       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
491     if (Attributes & ObjCDeclSpec::DQ_PR_strong)
492       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
493     if (Attributes & ObjCDeclSpec::DQ_PR_copy)
494       PIDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
495     PIDecl->setSetterName(SetterSel);
496   } else {
497     // Tailor the diagnostics for the common case where a readwrite
498     // property is declared both in the @interface and the continuation.
499     // This is a common error where the user often intended the original
500     // declaration to be readonly.
501     unsigned diag =
502       (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
503       (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite)
504       ? diag::err_use_continuation_class_redeclaration_readwrite
505       : diag::err_use_continuation_class;
506     Diag(AtLoc, diag)
507       << CCPrimary->getDeclName();
508     Diag(PIDecl->getLocation(), diag::note_property_declare);
509     return nullptr;
510   }
511   *isOverridingProperty = true;
512   // Make sure setter decl is synthesized, and added to primary class's list.
513   ProcessPropertyDecl(PIDecl, CCPrimary, PDecl, CDecl);
514   PDecl->setGetterMethodDecl(PIDecl->getGetterMethodDecl());
515   PDecl->setSetterMethodDecl(PIDecl->getSetterMethodDecl());
516   if (ASTMutationListener *L = Context.getASTMutationListener())
517     L->AddedObjCPropertyInClassExtension(PDecl, PIDecl, CDecl);
518   return PDecl;
519 }
520 
521 ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
522                                            ObjCContainerDecl *CDecl,
523                                            SourceLocation AtLoc,
524                                            SourceLocation LParenLoc,
525                                            FieldDeclarator &FD,
526                                            Selector GetterSel,
527                                            Selector SetterSel,
528                                            const bool isAssign,
529                                            const bool isReadWrite,
530                                            const unsigned Attributes,
531                                            const unsigned AttributesAsWritten,
532                                            QualType T,
533                                            TypeSourceInfo *TInfo,
534                                            tok::ObjCKeywordKind MethodImplKind,
535                                            DeclContext *lexicalDC){
536   IdentifierInfo *PropertyId = FD.D.getIdentifier();
537 
538   // Issue a warning if property is 'assign' as default and its object, which is
539   // gc'able conforms to NSCopying protocol
540   if (getLangOpts().getGC() != LangOptions::NonGC &&
541       isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign))
542     if (const ObjCObjectPointerType *ObjPtrTy =
543           T->getAs<ObjCObjectPointerType>()) {
544       ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
545       if (IDecl)
546         if (ObjCProtocolDecl* PNSCopying =
547             LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
548           if (IDecl->ClassImplementsProtocol(PNSCopying, true))
549             Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
550     }
551 
552   if (T->isObjCObjectType()) {
553     SourceLocation StarLoc = TInfo->getTypeLoc().getLocEnd();
554     StarLoc = getLocForEndOfToken(StarLoc);
555     Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
556       << FixItHint::CreateInsertion(StarLoc, "*");
557     T = Context.getObjCObjectPointerType(T);
558     SourceLocation TLoc = TInfo->getTypeLoc().getLocStart();
559     TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
560   }
561 
562   DeclContext *DC = cast<DeclContext>(CDecl);
563   ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
564                                                      FD.D.getIdentifierLoc(),
565                                                      PropertyId, AtLoc,
566                                                      LParenLoc, T, TInfo);
567 
568   if (ObjCPropertyDecl *prevDecl =
569         ObjCPropertyDecl::findPropertyDecl(DC, PropertyId)) {
570     Diag(PDecl->getLocation(), diag::err_duplicate_property);
571     Diag(prevDecl->getLocation(), diag::note_property_declare);
572     PDecl->setInvalidDecl();
573   }
574   else {
575     DC->addDecl(PDecl);
576     if (lexicalDC)
577       PDecl->setLexicalDeclContext(lexicalDC);
578   }
579 
580   if (T->isArrayType() || T->isFunctionType()) {
581     Diag(AtLoc, diag::err_property_type) << T;
582     PDecl->setInvalidDecl();
583   }
584 
585   ProcessDeclAttributes(S, PDecl, FD.D);
586 
587   // Regardless of setter/getter attribute, we save the default getter/setter
588   // selector names in anticipation of declaration of setter/getter methods.
589   PDecl->setGetterName(GetterSel);
590   PDecl->setSetterName(SetterSel);
591   PDecl->setPropertyAttributesAsWritten(
592                           makePropertyAttributesAsWritten(AttributesAsWritten));
593 
594   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
595     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
596 
597   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
598     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
599 
600   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
601     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
602 
603   if (isReadWrite)
604     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
605 
606   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
607     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
608 
609   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
610     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
611 
612   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
613     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
614 
615   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
616     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
617 
618   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
619     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
620 
621   if (isAssign)
622     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
623 
624   // In the semantic attributes, one of nonatomic or atomic is always set.
625   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
626     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
627   else
628     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
629 
630   // 'unsafe_unretained' is alias for 'assign'.
631   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
632     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
633   if (isAssign)
634     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
635 
636   if (MethodImplKind == tok::objc_required)
637     PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
638   else if (MethodImplKind == tok::objc_optional)
639     PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
640 
641   if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
642     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
643 
644   if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
645     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
646 
647   return PDecl;
648 }
649 
650 static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
651                                  ObjCPropertyDecl *property,
652                                  ObjCIvarDecl *ivar) {
653   if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
654 
655   QualType ivarType = ivar->getType();
656   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
657 
658   // The lifetime implied by the property's attributes.
659   Qualifiers::ObjCLifetime propertyLifetime =
660     getImpliedARCOwnership(property->getPropertyAttributes(),
661                            property->getType());
662 
663   // We're fine if they match.
664   if (propertyLifetime == ivarLifetime) return;
665 
666   // These aren't valid lifetimes for object ivars;  don't diagnose twice.
667   if (ivarLifetime == Qualifiers::OCL_None ||
668       ivarLifetime == Qualifiers::OCL_Autoreleasing)
669     return;
670 
671   // If the ivar is private, and it's implicitly __unsafe_unretained
672   // becaues of its type, then pretend it was actually implicitly
673   // __strong.  This is only sound because we're processing the
674   // property implementation before parsing any method bodies.
675   if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
676       propertyLifetime == Qualifiers::OCL_Strong &&
677       ivar->getAccessControl() == ObjCIvarDecl::Private) {
678     SplitQualType split = ivarType.split();
679     if (split.Quals.hasObjCLifetime()) {
680       assert(ivarType->isObjCARCImplicitlyUnretainedType());
681       split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
682       ivarType = S.Context.getQualifiedType(split);
683       ivar->setType(ivarType);
684       return;
685     }
686   }
687 
688   switch (propertyLifetime) {
689   case Qualifiers::OCL_Strong:
690     S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
691       << property->getDeclName()
692       << ivar->getDeclName()
693       << ivarLifetime;
694     break;
695 
696   case Qualifiers::OCL_Weak:
697     S.Diag(ivar->getLocation(), diag::error_weak_property)
698       << property->getDeclName()
699       << ivar->getDeclName();
700     break;
701 
702   case Qualifiers::OCL_ExplicitNone:
703     S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
704       << property->getDeclName()
705       << ivar->getDeclName()
706       << ((property->getPropertyAttributesAsWritten()
707            & ObjCPropertyDecl::OBJC_PR_assign) != 0);
708     break;
709 
710   case Qualifiers::OCL_Autoreleasing:
711     llvm_unreachable("properties cannot be autoreleasing");
712 
713   case Qualifiers::OCL_None:
714     // Any other property should be ignored.
715     return;
716   }
717 
718   S.Diag(property->getLocation(), diag::note_property_declare);
719   if (propertyImplLoc.isValid())
720     S.Diag(propertyImplLoc, diag::note_property_synthesize);
721 }
722 
723 /// setImpliedPropertyAttributeForReadOnlyProperty -
724 /// This routine evaludates life-time attributes for a 'readonly'
725 /// property with no known lifetime of its own, using backing
726 /// 'ivar's attribute, if any. If no backing 'ivar', property's
727 /// life-time is assumed 'strong'.
728 static void setImpliedPropertyAttributeForReadOnlyProperty(
729               ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
730   Qualifiers::ObjCLifetime propertyLifetime =
731     getImpliedARCOwnership(property->getPropertyAttributes(),
732                            property->getType());
733   if (propertyLifetime != Qualifiers::OCL_None)
734     return;
735 
736   if (!ivar) {
737     // if no backing ivar, make property 'strong'.
738     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
739     return;
740   }
741   // property assumes owenership of backing ivar.
742   QualType ivarType = ivar->getType();
743   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
744   if (ivarLifetime == Qualifiers::OCL_Strong)
745     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
746   else if (ivarLifetime == Qualifiers::OCL_Weak)
747     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
748   return;
749 }
750 
751 /// DiagnosePropertyMismatchDeclInProtocols - diagnose properties declared
752 /// in inherited protocols with mismatched types. Since any of them can
753 /// be candidate for synthesis.
754 static void
755 DiagnosePropertyMismatchDeclInProtocols(Sema &S, SourceLocation AtLoc,
756                                         ObjCInterfaceDecl *ClassDecl,
757                                         ObjCPropertyDecl *Property) {
758   ObjCInterfaceDecl::ProtocolPropertyMap PropMap;
759   for (const auto *PI : ClassDecl->all_referenced_protocols()) {
760     if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
761       PDecl->collectInheritedProtocolProperties(Property, PropMap);
762   }
763   if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass())
764     while (SDecl) {
765       for (const auto *PI : SDecl->all_referenced_protocols()) {
766         if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
767           PDecl->collectInheritedProtocolProperties(Property, PropMap);
768       }
769       SDecl = SDecl->getSuperClass();
770     }
771 
772   if (PropMap.empty())
773     return;
774 
775   QualType RHSType = S.Context.getCanonicalType(Property->getType());
776   bool FirsTime = true;
777   for (ObjCInterfaceDecl::ProtocolPropertyMap::iterator
778        I = PropMap.begin(), E = PropMap.end(); I != E; I++) {
779     ObjCPropertyDecl *Prop = I->second;
780     QualType LHSType = S.Context.getCanonicalType(Prop->getType());
781     if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
782       bool IncompatibleObjC = false;
783       QualType ConvertedType;
784       if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
785           || IncompatibleObjC) {
786         if (FirsTime) {
787           S.Diag(Property->getLocation(), diag::warn_protocol_property_mismatch)
788             << Property->getType();
789           FirsTime = false;
790         }
791         S.Diag(Prop->getLocation(), diag::note_protocol_property_declare)
792           << Prop->getType();
793       }
794     }
795   }
796   if (!FirsTime && AtLoc.isValid())
797     S.Diag(AtLoc, diag::note_property_synthesize);
798 }
799 
800 /// ActOnPropertyImplDecl - This routine performs semantic checks and
801 /// builds the AST node for a property implementation declaration; declared
802 /// as \@synthesize or \@dynamic.
803 ///
804 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
805                                   SourceLocation AtLoc,
806                                   SourceLocation PropertyLoc,
807                                   bool Synthesize,
808                                   IdentifierInfo *PropertyId,
809                                   IdentifierInfo *PropertyIvar,
810                                   SourceLocation PropertyIvarLoc) {
811   ObjCContainerDecl *ClassImpDecl =
812     dyn_cast<ObjCContainerDecl>(CurContext);
813   // Make sure we have a context for the property implementation declaration.
814   if (!ClassImpDecl) {
815     Diag(AtLoc, diag::error_missing_property_context);
816     return nullptr;
817   }
818   if (PropertyIvarLoc.isInvalid())
819     PropertyIvarLoc = PropertyLoc;
820   SourceLocation PropertyDiagLoc = PropertyLoc;
821   if (PropertyDiagLoc.isInvalid())
822     PropertyDiagLoc = ClassImpDecl->getLocStart();
823   ObjCPropertyDecl *property = nullptr;
824   ObjCInterfaceDecl *IDecl = nullptr;
825   // Find the class or category class where this property must have
826   // a declaration.
827   ObjCImplementationDecl *IC = nullptr;
828   ObjCCategoryImplDecl *CatImplClass = nullptr;
829   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
830     IDecl = IC->getClassInterface();
831     // We always synthesize an interface for an implementation
832     // without an interface decl. So, IDecl is always non-zero.
833     assert(IDecl &&
834            "ActOnPropertyImplDecl - @implementation without @interface");
835 
836     // Look for this property declaration in the @implementation's @interface
837     property = IDecl->FindPropertyDeclaration(PropertyId);
838     if (!property) {
839       Diag(PropertyLoc, diag::error_bad_property_decl) << IDecl->getDeclName();
840       return nullptr;
841     }
842     unsigned PIkind = property->getPropertyAttributesAsWritten();
843     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
844                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
845       if (AtLoc.isValid())
846         Diag(AtLoc, diag::warn_implicit_atomic_property);
847       else
848         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
849       Diag(property->getLocation(), diag::note_property_declare);
850     }
851 
852     if (const ObjCCategoryDecl *CD =
853         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
854       if (!CD->IsClassExtension()) {
855         Diag(PropertyLoc, diag::error_category_property) << CD->getDeclName();
856         Diag(property->getLocation(), diag::note_property_declare);
857         return nullptr;
858       }
859     }
860     if (Synthesize&&
861         (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
862         property->hasAttr<IBOutletAttr>() &&
863         !AtLoc.isValid()) {
864       bool ReadWriteProperty = false;
865       // Search into the class extensions and see if 'readonly property is
866       // redeclared 'readwrite', then no warning is to be issued.
867       for (auto *Ext : IDecl->known_extensions()) {
868         DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
869         if (!R.empty())
870           if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
871             PIkind = ExtProp->getPropertyAttributesAsWritten();
872             if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
873               ReadWriteProperty = true;
874               break;
875             }
876           }
877       }
878 
879       if (!ReadWriteProperty) {
880         Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
881             << property;
882         SourceLocation readonlyLoc;
883         if (LocPropertyAttribute(Context, "readonly",
884                                  property->getLParenLoc(), readonlyLoc)) {
885           SourceLocation endLoc =
886             readonlyLoc.getLocWithOffset(strlen("readonly")-1);
887           SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
888           Diag(property->getLocation(),
889                diag::note_auto_readonly_iboutlet_fixup_suggest) <<
890           FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
891         }
892       }
893     }
894     if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
895       DiagnosePropertyMismatchDeclInProtocols(*this, AtLoc, IDecl, property);
896 
897   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
898     if (Synthesize) {
899       Diag(AtLoc, diag::error_synthesize_category_decl);
900       return nullptr;
901     }
902     IDecl = CatImplClass->getClassInterface();
903     if (!IDecl) {
904       Diag(AtLoc, diag::error_missing_property_interface);
905       return nullptr;
906     }
907     ObjCCategoryDecl *Category =
908     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
909 
910     // If category for this implementation not found, it is an error which
911     // has already been reported eralier.
912     if (!Category)
913       return nullptr;
914     // Look for this property declaration in @implementation's category
915     property = Category->FindPropertyDeclaration(PropertyId);
916     if (!property) {
917       Diag(PropertyLoc, diag::error_bad_category_property_decl)
918       << Category->getDeclName();
919       return nullptr;
920     }
921   } else {
922     Diag(AtLoc, diag::error_bad_property_context);
923     return nullptr;
924   }
925   ObjCIvarDecl *Ivar = nullptr;
926   bool CompleteTypeErr = false;
927   bool compat = true;
928   // Check that we have a valid, previously declared ivar for @synthesize
929   if (Synthesize) {
930     // @synthesize
931     if (!PropertyIvar)
932       PropertyIvar = PropertyId;
933     // Check that this is a previously declared 'ivar' in 'IDecl' interface
934     ObjCInterfaceDecl *ClassDeclared;
935     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
936     QualType PropType = property->getType();
937     QualType PropertyIvarType = PropType.getNonReferenceType();
938 
939     if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
940                             diag::err_incomplete_synthesized_property,
941                             property->getDeclName())) {
942       Diag(property->getLocation(), diag::note_property_declare);
943       CompleteTypeErr = true;
944     }
945 
946     if (getLangOpts().ObjCAutoRefCount &&
947         (property->getPropertyAttributesAsWritten() &
948          ObjCPropertyDecl::OBJC_PR_readonly) &&
949         PropertyIvarType->isObjCRetainableType()) {
950       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
951     }
952 
953     ObjCPropertyDecl::PropertyAttributeKind kind
954       = property->getPropertyAttributes();
955 
956     // Add GC __weak to the ivar type if the property is weak.
957     if ((kind & ObjCPropertyDecl::OBJC_PR_weak) &&
958         getLangOpts().getGC() != LangOptions::NonGC) {
959       assert(!getLangOpts().ObjCAutoRefCount);
960       if (PropertyIvarType.isObjCGCStrong()) {
961         Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
962         Diag(property->getLocation(), diag::note_property_declare);
963       } else {
964         PropertyIvarType =
965           Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
966       }
967     }
968     if (AtLoc.isInvalid()) {
969       // Check when default synthesizing a property that there is
970       // an ivar matching property name and issue warning; since this
971       // is the most common case of not using an ivar used for backing
972       // property in non-default synthesis case.
973       ObjCInterfaceDecl *ClassDeclared=nullptr;
974       ObjCIvarDecl *originalIvar =
975       IDecl->lookupInstanceVariable(property->getIdentifier(),
976                                     ClassDeclared);
977       if (originalIvar) {
978         Diag(PropertyDiagLoc,
979              diag::warn_autosynthesis_property_ivar_match)
980         << PropertyId << (Ivar == nullptr) << PropertyIvar
981         << originalIvar->getIdentifier();
982         Diag(property->getLocation(), diag::note_property_declare);
983         Diag(originalIvar->getLocation(), diag::note_ivar_decl);
984       }
985     }
986 
987     if (!Ivar) {
988       // In ARC, give the ivar a lifetime qualifier based on the
989       // property attributes.
990       if (getLangOpts().ObjCAutoRefCount &&
991           !PropertyIvarType.getObjCLifetime() &&
992           PropertyIvarType->isObjCRetainableType()) {
993 
994         // It's an error if we have to do this and the user didn't
995         // explicitly write an ownership attribute on the property.
996         if (!property->hasWrittenStorageAttribute() &&
997             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
998           Diag(PropertyDiagLoc,
999                diag::err_arc_objc_property_default_assign_on_object);
1000           Diag(property->getLocation(), diag::note_property_declare);
1001         } else {
1002           Qualifiers::ObjCLifetime lifetime =
1003             getImpliedARCOwnership(kind, PropertyIvarType);
1004           assert(lifetime && "no lifetime for property?");
1005           if (lifetime == Qualifiers::OCL_Weak) {
1006             bool err = false;
1007             if (const ObjCObjectPointerType *ObjT =
1008                 PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1009               const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1010               if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1011                 Diag(property->getLocation(),
1012                      diag::err_arc_weak_unavailable_property) << PropertyIvarType;
1013                 Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1014                   << ClassImpDecl->getName();
1015                 err = true;
1016               }
1017             }
1018             if (!err && !getLangOpts().ObjCARCWeak) {
1019               Diag(PropertyDiagLoc, diag::err_arc_weak_no_runtime);
1020               Diag(property->getLocation(), diag::note_property_declare);
1021             }
1022           }
1023 
1024           Qualifiers qs;
1025           qs.addObjCLifetime(lifetime);
1026           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1027         }
1028       }
1029 
1030       if (kind & ObjCPropertyDecl::OBJC_PR_weak &&
1031           !getLangOpts().ObjCAutoRefCount &&
1032           getLangOpts().getGC() == LangOptions::NonGC) {
1033         Diag(PropertyDiagLoc, diag::error_synthesize_weak_non_arc_or_gc);
1034         Diag(property->getLocation(), diag::note_property_declare);
1035       }
1036 
1037       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1038                                   PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1039                                   PropertyIvarType, /*Dinfo=*/nullptr,
1040                                   ObjCIvarDecl::Private,
1041                                   (Expr *)nullptr, true);
1042       if (RequireNonAbstractType(PropertyIvarLoc,
1043                                  PropertyIvarType,
1044                                  diag::err_abstract_type_in_decl,
1045                                  AbstractSynthesizedIvarType)) {
1046         Diag(property->getLocation(), diag::note_property_declare);
1047         Ivar->setInvalidDecl();
1048       } else if (CompleteTypeErr)
1049           Ivar->setInvalidDecl();
1050       ClassImpDecl->addDecl(Ivar);
1051       IDecl->makeDeclVisibleInContext(Ivar);
1052 
1053       if (getLangOpts().ObjCRuntime.isFragile())
1054         Diag(PropertyDiagLoc, diag::error_missing_property_ivar_decl)
1055             << PropertyId;
1056       // Note! I deliberately want it to fall thru so, we have a
1057       // a property implementation and to avoid future warnings.
1058     } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1059                !declaresSameEntity(ClassDeclared, IDecl)) {
1060       Diag(PropertyDiagLoc, diag::error_ivar_in_superclass_use)
1061       << property->getDeclName() << Ivar->getDeclName()
1062       << ClassDeclared->getDeclName();
1063       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1064       << Ivar << Ivar->getName();
1065       // Note! I deliberately want it to fall thru so more errors are caught.
1066     }
1067     property->setPropertyIvarDecl(Ivar);
1068 
1069     QualType IvarType = Context.getCanonicalType(Ivar->getType());
1070 
1071     // Check that type of property and its ivar are type compatible.
1072     if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1073       if (isa<ObjCObjectPointerType>(PropertyIvarType)
1074           && isa<ObjCObjectPointerType>(IvarType))
1075         compat =
1076           Context.canAssignObjCInterfaces(
1077                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
1078                                   IvarType->getAs<ObjCObjectPointerType>());
1079       else {
1080         compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1081                                              IvarType)
1082                     == Compatible);
1083       }
1084       if (!compat) {
1085         Diag(PropertyDiagLoc, diag::error_property_ivar_type)
1086           << property->getDeclName() << PropType
1087           << Ivar->getDeclName() << IvarType;
1088         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1089         // Note! I deliberately want it to fall thru so, we have a
1090         // a property implementation and to avoid future warnings.
1091       }
1092       else {
1093         // FIXME! Rules for properties are somewhat different that those
1094         // for assignments. Use a new routine to consolidate all cases;
1095         // specifically for property redeclarations as well as for ivars.
1096         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1097         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1098         if (lhsType != rhsType &&
1099             lhsType->isArithmeticType()) {
1100           Diag(PropertyDiagLoc, diag::error_property_ivar_type)
1101             << property->getDeclName() << PropType
1102             << Ivar->getDeclName() << IvarType;
1103           Diag(Ivar->getLocation(), diag::note_ivar_decl);
1104           // Fall thru - see previous comment
1105         }
1106       }
1107       // __weak is explicit. So it works on Canonical type.
1108       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1109            getLangOpts().getGC() != LangOptions::NonGC)) {
1110         Diag(PropertyDiagLoc, diag::error_weak_property)
1111         << property->getDeclName() << Ivar->getDeclName();
1112         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1113         // Fall thru - see previous comment
1114       }
1115       // Fall thru - see previous comment
1116       if ((property->getType()->isObjCObjectPointerType() ||
1117            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1118           getLangOpts().getGC() != LangOptions::NonGC) {
1119         Diag(PropertyDiagLoc, diag::error_strong_property)
1120         << property->getDeclName() << Ivar->getDeclName();
1121         // Fall thru - see previous comment
1122       }
1123     }
1124     if (getLangOpts().ObjCAutoRefCount)
1125       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1126   } else if (PropertyIvar)
1127     // @dynamic
1128     Diag(PropertyDiagLoc, diag::error_dynamic_property_ivar_decl);
1129 
1130   assert (property && "ActOnPropertyImplDecl - property declaration missing");
1131   ObjCPropertyImplDecl *PIDecl =
1132   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1133                                property,
1134                                (Synthesize ?
1135                                 ObjCPropertyImplDecl::Synthesize
1136                                 : ObjCPropertyImplDecl::Dynamic),
1137                                Ivar, PropertyIvarLoc);
1138 
1139   if (CompleteTypeErr || !compat)
1140     PIDecl->setInvalidDecl();
1141 
1142   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1143     getterMethod->createImplicitParams(Context, IDecl);
1144     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1145         Ivar->getType()->isRecordType()) {
1146       // For Objective-C++, need to synthesize the AST for the IVAR object to be
1147       // returned by the getter as it must conform to C++'s copy-return rules.
1148       // FIXME. Eventually we want to do this for Objective-C as well.
1149       SynthesizedFunctionScope Scope(*this, getterMethod);
1150       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1151       DeclRefExpr *SelfExpr =
1152         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1153                                   VK_LValue, PropertyDiagLoc);
1154       MarkDeclRefReferenced(SelfExpr);
1155       Expr *LoadSelfExpr =
1156         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1157                                  CK_LValueToRValue, SelfExpr, nullptr,
1158                                  VK_RValue);
1159       Expr *IvarRefExpr =
1160         new (Context) ObjCIvarRefExpr(Ivar, Ivar->getType(), PropertyDiagLoc,
1161                                       Ivar->getLocation(),
1162                                       LoadSelfExpr, true, true);
1163       ExprResult Res = PerformCopyInitialization(
1164           InitializedEntity::InitializeResult(PropertyDiagLoc,
1165                                               getterMethod->getReturnType(),
1166                                               /*NRVO=*/false),
1167           PropertyDiagLoc, IvarRefExpr);
1168       if (!Res.isInvalid()) {
1169         Expr *ResExpr = Res.getAs<Expr>();
1170         if (ResExpr)
1171           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1172         PIDecl->setGetterCXXConstructor(ResExpr);
1173       }
1174     }
1175     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1176         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1177       Diag(getterMethod->getLocation(),
1178            diag::warn_property_getter_owning_mismatch);
1179       Diag(property->getLocation(), diag::note_property_declare);
1180     }
1181     if (getLangOpts().ObjCAutoRefCount && Synthesize)
1182       switch (getterMethod->getMethodFamily()) {
1183         case OMF_retain:
1184         case OMF_retainCount:
1185         case OMF_release:
1186         case OMF_autorelease:
1187           Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1188             << 1 << getterMethod->getSelector();
1189           break;
1190         default:
1191           break;
1192       }
1193   }
1194   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1195     setterMethod->createImplicitParams(Context, IDecl);
1196     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1197         Ivar->getType()->isRecordType()) {
1198       // FIXME. Eventually we want to do this for Objective-C as well.
1199       SynthesizedFunctionScope Scope(*this, setterMethod);
1200       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1201       DeclRefExpr *SelfExpr =
1202         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1203                                   VK_LValue, PropertyDiagLoc);
1204       MarkDeclRefReferenced(SelfExpr);
1205       Expr *LoadSelfExpr =
1206         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1207                                  CK_LValueToRValue, SelfExpr, nullptr,
1208                                  VK_RValue);
1209       Expr *lhs =
1210         new (Context) ObjCIvarRefExpr(Ivar, Ivar->getType(), PropertyDiagLoc,
1211                                       Ivar->getLocation(),
1212                                       LoadSelfExpr, true, true);
1213       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1214       ParmVarDecl *Param = (*P);
1215       QualType T = Param->getType().getNonReferenceType();
1216       DeclRefExpr *rhs = new (Context) DeclRefExpr(Param, false, T,
1217                                                    VK_LValue, PropertyDiagLoc);
1218       MarkDeclRefReferenced(rhs);
1219       ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1220                                   BO_Assign, lhs, rhs);
1221       if (property->getPropertyAttributes() &
1222           ObjCPropertyDecl::OBJC_PR_atomic) {
1223         Expr *callExpr = Res.getAs<Expr>();
1224         if (const CXXOperatorCallExpr *CXXCE =
1225               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1226           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1227             if (!FuncDecl->isTrivial())
1228               if (property->getType()->isReferenceType()) {
1229                 Diag(PropertyDiagLoc,
1230                      diag::err_atomic_property_nontrivial_assign_op)
1231                     << property->getType();
1232                 Diag(FuncDecl->getLocStart(),
1233                      diag::note_callee_decl) << FuncDecl;
1234               }
1235       }
1236       PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1237     }
1238   }
1239 
1240   if (IC) {
1241     if (Synthesize)
1242       if (ObjCPropertyImplDecl *PPIDecl =
1243           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1244         Diag(PropertyLoc, diag::error_duplicate_ivar_use)
1245         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1246         << PropertyIvar;
1247         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1248       }
1249 
1250     if (ObjCPropertyImplDecl *PPIDecl
1251         = IC->FindPropertyImplDecl(PropertyId)) {
1252       Diag(PropertyLoc, diag::error_property_implemented) << PropertyId;
1253       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1254       return nullptr;
1255     }
1256     IC->addPropertyImplementation(PIDecl);
1257     if (getLangOpts().ObjCDefaultSynthProperties &&
1258         getLangOpts().ObjCRuntime.isNonFragile() &&
1259         !IDecl->isObjCRequiresPropertyDefs()) {
1260       // Diagnose if an ivar was lazily synthesdized due to a previous
1261       // use and if 1) property is @dynamic or 2) property is synthesized
1262       // but it requires an ivar of different name.
1263       ObjCInterfaceDecl *ClassDeclared=nullptr;
1264       ObjCIvarDecl *Ivar = nullptr;
1265       if (!Synthesize)
1266         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1267       else {
1268         if (PropertyIvar && PropertyIvar != PropertyId)
1269           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1270       }
1271       // Issue diagnostics only if Ivar belongs to current class.
1272       if (Ivar && Ivar->getSynthesize() &&
1273           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1274         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1275         << PropertyId;
1276         Ivar->setInvalidDecl();
1277       }
1278     }
1279   } else {
1280     if (Synthesize)
1281       if (ObjCPropertyImplDecl *PPIDecl =
1282           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1283         Diag(PropertyDiagLoc, diag::error_duplicate_ivar_use)
1284         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1285         << PropertyIvar;
1286         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1287       }
1288 
1289     if (ObjCPropertyImplDecl *PPIDecl =
1290         CatImplClass->FindPropertyImplDecl(PropertyId)) {
1291       Diag(PropertyDiagLoc, diag::error_property_implemented) << PropertyId;
1292       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1293       return nullptr;
1294     }
1295     CatImplClass->addPropertyImplementation(PIDecl);
1296   }
1297 
1298   return PIDecl;
1299 }
1300 
1301 //===----------------------------------------------------------------------===//
1302 // Helper methods.
1303 //===----------------------------------------------------------------------===//
1304 
1305 /// DiagnosePropertyMismatch - Compares two properties for their
1306 /// attributes and types and warns on a variety of inconsistencies.
1307 ///
1308 void
1309 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1310                                ObjCPropertyDecl *SuperProperty,
1311                                const IdentifierInfo *inheritedName,
1312                                bool OverridingProtocolProperty) {
1313   ObjCPropertyDecl::PropertyAttributeKind CAttr =
1314     Property->getPropertyAttributes();
1315   ObjCPropertyDecl::PropertyAttributeKind SAttr =
1316     SuperProperty->getPropertyAttributes();
1317 
1318   // We allow readonly properties without an explicit ownership
1319   // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1320   // to be overridden by a property with any explicit ownership in the subclass.
1321   if (!OverridingProtocolProperty &&
1322       !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1323     ;
1324   else {
1325     if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
1326         && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
1327       Diag(Property->getLocation(), diag::warn_readonly_property)
1328         << Property->getDeclName() << inheritedName;
1329     if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
1330         != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
1331       Diag(Property->getLocation(), diag::warn_property_attribute)
1332         << Property->getDeclName() << "copy" << inheritedName;
1333     else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
1334       unsigned CAttrRetain =
1335         (CAttr &
1336          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1337       unsigned SAttrRetain =
1338         (SAttr &
1339          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1340       bool CStrong = (CAttrRetain != 0);
1341       bool SStrong = (SAttrRetain != 0);
1342       if (CStrong != SStrong)
1343         Diag(Property->getLocation(), diag::warn_property_attribute)
1344           << Property->getDeclName() << "retain (or strong)" << inheritedName;
1345     }
1346   }
1347 
1348   if ((CAttr & ObjCPropertyDecl::OBJC_PR_nonatomic)
1349       != (SAttr & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
1350     Diag(Property->getLocation(), diag::warn_property_attribute)
1351       << Property->getDeclName() << "atomic" << inheritedName;
1352     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1353   }
1354   if (Property->getSetterName() != SuperProperty->getSetterName()) {
1355     Diag(Property->getLocation(), diag::warn_property_attribute)
1356       << Property->getDeclName() << "setter" << inheritedName;
1357     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1358   }
1359   if (Property->getGetterName() != SuperProperty->getGetterName()) {
1360     Diag(Property->getLocation(), diag::warn_property_attribute)
1361       << Property->getDeclName() << "getter" << inheritedName;
1362     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1363   }
1364 
1365   QualType LHSType =
1366     Context.getCanonicalType(SuperProperty->getType());
1367   QualType RHSType =
1368     Context.getCanonicalType(Property->getType());
1369 
1370   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1371     // Do cases not handled in above.
1372     // FIXME. For future support of covariant property types, revisit this.
1373     bool IncompatibleObjC = false;
1374     QualType ConvertedType;
1375     if (!isObjCPointerConversion(RHSType, LHSType,
1376                                  ConvertedType, IncompatibleObjC) ||
1377         IncompatibleObjC) {
1378         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1379         << Property->getType() << SuperProperty->getType() << inheritedName;
1380       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1381     }
1382   }
1383 }
1384 
1385 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1386                                             ObjCMethodDecl *GetterMethod,
1387                                             SourceLocation Loc) {
1388   if (!GetterMethod)
1389     return false;
1390   QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1391   QualType PropertyIvarType = property->getType().getNonReferenceType();
1392   bool compat = Context.hasSameType(PropertyIvarType, GetterType);
1393   if (!compat) {
1394     if (isa<ObjCObjectPointerType>(PropertyIvarType) &&
1395         isa<ObjCObjectPointerType>(GetterType))
1396       compat =
1397         Context.canAssignObjCInterfaces(
1398                                       GetterType->getAs<ObjCObjectPointerType>(),
1399                                       PropertyIvarType->getAs<ObjCObjectPointerType>());
1400     else if (CheckAssignmentConstraints(Loc, GetterType, PropertyIvarType)
1401               != Compatible) {
1402           Diag(Loc, diag::error_property_accessor_type)
1403             << property->getDeclName() << PropertyIvarType
1404             << GetterMethod->getSelector() << GetterType;
1405           Diag(GetterMethod->getLocation(), diag::note_declared_at);
1406           return true;
1407     } else {
1408       compat = true;
1409       QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1410       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1411       if (lhsType != rhsType && lhsType->isArithmeticType())
1412         compat = false;
1413     }
1414   }
1415 
1416   if (!compat) {
1417     Diag(Loc, diag::warn_accessor_property_type_mismatch)
1418     << property->getDeclName()
1419     << GetterMethod->getSelector();
1420     Diag(GetterMethod->getLocation(), diag::note_declared_at);
1421     return true;
1422   }
1423 
1424   return false;
1425 }
1426 
1427 /// CollectImmediateProperties - This routine collects all properties in
1428 /// the class and its conforming protocols; but not those in its super class.
1429 static void CollectImmediateProperties(ObjCContainerDecl *CDecl,
1430                                        ObjCContainerDecl::PropertyMap &PropMap,
1431                                        ObjCContainerDecl::PropertyMap &SuperPropMap,
1432                                        bool IncludeProtocols = true) {
1433 
1434   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1435     for (auto *Prop : IDecl->properties())
1436       PropMap[Prop->getIdentifier()] = Prop;
1437     if (IncludeProtocols) {
1438       // Scan through class's protocols.
1439       for (auto *PI : IDecl->all_referenced_protocols())
1440         CollectImmediateProperties(PI, PropMap, SuperPropMap);
1441     }
1442   }
1443   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1444     if (!CATDecl->IsClassExtension())
1445       for (auto *Prop : CATDecl->properties())
1446         PropMap[Prop->getIdentifier()] = Prop;
1447     if (IncludeProtocols) {
1448       // Scan through class's protocols.
1449       for (auto *PI : CATDecl->protocols())
1450         CollectImmediateProperties(PI, PropMap, SuperPropMap);
1451     }
1452   }
1453   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1454     for (auto *Prop : PDecl->properties()) {
1455       ObjCPropertyDecl *PropertyFromSuper = SuperPropMap[Prop->getIdentifier()];
1456       // Exclude property for protocols which conform to class's super-class,
1457       // as super-class has to implement the property.
1458       if (!PropertyFromSuper ||
1459           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1460         ObjCPropertyDecl *&PropEntry = PropMap[Prop->getIdentifier()];
1461         if (!PropEntry)
1462           PropEntry = Prop;
1463       }
1464     }
1465     // scan through protocol's protocols.
1466     for (auto *PI : PDecl->protocols())
1467       CollectImmediateProperties(PI, PropMap, SuperPropMap);
1468   }
1469 }
1470 
1471 /// CollectSuperClassPropertyImplementations - This routine collects list of
1472 /// properties to be implemented in super class(s) and also coming from their
1473 /// conforming protocols.
1474 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1475                                     ObjCInterfaceDecl::PropertyMap &PropMap) {
1476   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1477     ObjCInterfaceDecl::PropertyDeclOrder PO;
1478     while (SDecl) {
1479       SDecl->collectPropertiesToImplement(PropMap, PO);
1480       SDecl = SDecl->getSuperClass();
1481     }
1482   }
1483 }
1484 
1485 /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1486 /// an ivar synthesized for 'Method' and 'Method' is a property accessor
1487 /// declared in class 'IFace'.
1488 bool
1489 Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1490                                      ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1491   if (!IV->getSynthesize())
1492     return false;
1493   ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1494                                             Method->isInstanceMethod());
1495   if (!IMD || !IMD->isPropertyAccessor())
1496     return false;
1497 
1498   // look up a property declaration whose one of its accessors is implemented
1499   // by this method.
1500   for (const auto *Property : IFace->properties()) {
1501     if ((Property->getGetterName() == IMD->getSelector() ||
1502          Property->getSetterName() == IMD->getSelector()) &&
1503         (Property->getPropertyIvarDecl() == IV))
1504       return true;
1505   }
1506   return false;
1507 }
1508 
1509 static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1510                                          ObjCPropertyDecl *Prop) {
1511   bool SuperClassImplementsGetter = false;
1512   bool SuperClassImplementsSetter = false;
1513   if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1514     SuperClassImplementsSetter = true;
1515 
1516   while (IDecl->getSuperClass()) {
1517     ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1518     if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1519       SuperClassImplementsGetter = true;
1520 
1521     if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1522       SuperClassImplementsSetter = true;
1523     if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1524       return true;
1525     IDecl = IDecl->getSuperClass();
1526   }
1527   return false;
1528 }
1529 
1530 /// \brief Default synthesizes all properties which must be synthesized
1531 /// in class's \@implementation.
1532 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl* IMPDecl,
1533                                        ObjCInterfaceDecl *IDecl) {
1534 
1535   ObjCInterfaceDecl::PropertyMap PropMap;
1536   ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
1537   IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
1538   if (PropMap.empty())
1539     return;
1540   ObjCInterfaceDecl::PropertyMap SuperPropMap;
1541   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1542 
1543   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
1544     ObjCPropertyDecl *Prop = PropertyOrder[i];
1545     // Is there a matching property synthesize/dynamic?
1546     if (Prop->isInvalidDecl() ||
1547         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1548       continue;
1549     // Property may have been synthesized by user.
1550     if (IMPDecl->FindPropertyImplDecl(Prop->getIdentifier()))
1551       continue;
1552     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1553       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1554         continue;
1555       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1556         continue;
1557     }
1558     if (ObjCPropertyImplDecl *PID =
1559         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1560       Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1561         << Prop->getIdentifier();
1562       if (!PID->getLocation().isInvalid())
1563         Diag(PID->getLocation(), diag::note_property_synthesize);
1564       continue;
1565     }
1566     ObjCPropertyDecl *PropInSuperClass = SuperPropMap[Prop->getIdentifier()];
1567     if (ObjCProtocolDecl *Proto =
1568           dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1569       // We won't auto-synthesize properties declared in protocols.
1570       // Suppress the warning if class's superclass implements property's
1571       // getter and implements property's setter (if readwrite property).
1572       // Or, if property is going to be implemented in its super class.
1573       if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1574         Diag(IMPDecl->getLocation(),
1575              diag::warn_auto_synthesizing_protocol_property)
1576           << Prop << Proto;
1577         Diag(Prop->getLocation(), diag::note_property_declare);
1578       }
1579       continue;
1580     }
1581     // If property to be implemented in the super class, ignore.
1582     if (PropInSuperClass) {
1583       if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
1584           (PropInSuperClass->getPropertyAttributes() &
1585            ObjCPropertyDecl::OBJC_PR_readonly) &&
1586           !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1587           !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1588         Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1589         << Prop->getIdentifier();
1590         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1591       }
1592       else {
1593         Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1594         << Prop->getIdentifier();
1595         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1596         Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1597       }
1598       continue;
1599     }
1600     // We use invalid SourceLocations for the synthesized ivars since they
1601     // aren't really synthesized at a particular location; they just exist.
1602     // Saying that they are located at the @implementation isn't really going
1603     // to help users.
1604     ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1605       ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1606                             true,
1607                             /* property = */ Prop->getIdentifier(),
1608                             /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1609                             Prop->getLocation()));
1610     if (PIDecl) {
1611       Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1612       Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1613     }
1614   }
1615 }
1616 
1617 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D) {
1618   if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1619     return;
1620   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1621   if (!IC)
1622     return;
1623   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1624     if (!IDecl->isObjCRequiresPropertyDefs())
1625       DefaultSynthesizeProperties(S, IC, IDecl);
1626 }
1627 
1628 static void DiagnoseUnimplementedAccessor(Sema &S,
1629                                           ObjCInterfaceDecl *PrimaryClass,
1630                                           Selector Method,
1631                                           ObjCImplDecl* IMPDecl,
1632                                           ObjCContainerDecl *CDecl,
1633                                           ObjCCategoryDecl *C,
1634                                           ObjCPropertyDecl *Prop,
1635                                           Sema::SelectorSet &SMap) {
1636   // When reporting on missing property setter/getter implementation in
1637   // categories, do not report when they are declared in primary class,
1638   // class's protocol, or one of it super classes. This is because,
1639   // the class is going to implement them.
1640   if (!SMap.count(Method) &&
1641       (PrimaryClass == nullptr ||
1642        !PrimaryClass->lookupPropertyAccessor(Method, C))) {
1643         S.Diag(IMPDecl->getLocation(),
1644                isa<ObjCCategoryDecl>(CDecl) ?
1645                diag::warn_setter_getter_impl_required_in_category :
1646                diag::warn_setter_getter_impl_required)
1647             << Prop->getDeclName() << Method;
1648         S.Diag(Prop->getLocation(),
1649              diag::note_property_declare);
1650         if (S.LangOpts.ObjCDefaultSynthProperties &&
1651             S.LangOpts.ObjCRuntime.isNonFragile())
1652           if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1653             if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1654             S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1655       }
1656 }
1657 
1658 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1659                                            ObjCContainerDecl *CDecl,
1660                                            bool SynthesizeProperties) {
1661   ObjCContainerDecl::PropertyMap PropMap;
1662   ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
1663 
1664   if (!SynthesizeProperties) {
1665     ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1666     // Gather properties which need not be implemented in this class
1667     // or category.
1668     if (!IDecl)
1669       if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1670         // For categories, no need to implement properties declared in
1671         // its primary class (and its super classes) if property is
1672         // declared in one of those containers.
1673         if ((IDecl = C->getClassInterface())) {
1674           ObjCInterfaceDecl::PropertyDeclOrder PO;
1675           IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
1676         }
1677       }
1678     if (IDecl)
1679       CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
1680 
1681     CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap);
1682   }
1683 
1684   // Scan the @interface to see if any of the protocols it adopts
1685   // require an explicit implementation, via attribute
1686   // 'objc_protocol_requires_explicit_implementation'.
1687   if (IDecl) {
1688     std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
1689 
1690     for (auto *PDecl : IDecl->all_referenced_protocols()) {
1691       if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
1692         continue;
1693       // Lazily construct a set of all the properties in the @interface
1694       // of the class, without looking at the superclass.  We cannot
1695       // use the call to CollectImmediateProperties() above as that
1696       // utilizes information from the super class's properties as well
1697       // as scans the adopted protocols.  This work only triggers for protocols
1698       // with the attribute, which is very rare, and only occurs when
1699       // analyzing the @implementation.
1700       if (!LazyMap) {
1701         ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1702         LazyMap.reset(new ObjCContainerDecl::PropertyMap());
1703         CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
1704                                    /* IncludeProtocols */ false);
1705       }
1706       // Add the properties of 'PDecl' to the list of properties that
1707       // need to be implemented.
1708       for (auto *PropDecl : PDecl->properties()) {
1709         if ((*LazyMap)[PropDecl->getIdentifier()])
1710           continue;
1711         PropMap[PropDecl->getIdentifier()] = PropDecl;
1712       }
1713     }
1714   }
1715 
1716   if (PropMap.empty())
1717     return;
1718 
1719   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
1720   for (const auto *I : IMPDecl->property_impls())
1721     PropImplMap.insert(I->getPropertyDecl());
1722 
1723   SelectorSet InsMap;
1724   // Collect property accessors implemented in current implementation.
1725   for (const auto *I : IMPDecl->instance_methods())
1726     InsMap.insert(I->getSelector());
1727 
1728   ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
1729   ObjCInterfaceDecl *PrimaryClass = nullptr;
1730   if (C && !C->IsClassExtension())
1731     if ((PrimaryClass = C->getClassInterface()))
1732       // Report unimplemented properties in the category as well.
1733       if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
1734         // When reporting on missing setter/getters, do not report when
1735         // setter/getter is implemented in category's primary class
1736         // implementation.
1737         for (const auto *I : IMP->instance_methods())
1738           InsMap.insert(I->getSelector());
1739       }
1740 
1741   for (ObjCContainerDecl::PropertyMap::iterator
1742        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
1743     ObjCPropertyDecl *Prop = P->second;
1744     // Is there a matching propery synthesize/dynamic?
1745     if (Prop->isInvalidDecl() ||
1746         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
1747         PropImplMap.count(Prop) ||
1748         Prop->getAvailability() == AR_Unavailable)
1749       continue;
1750 
1751     // Diagnose unimplemented getters and setters.
1752     DiagnoseUnimplementedAccessor(*this,
1753           PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
1754     if (!Prop->isReadOnly())
1755       DiagnoseUnimplementedAccessor(*this,
1756                                     PrimaryClass, Prop->getSetterName(),
1757                                     IMPDecl, CDecl, C, Prop, InsMap);
1758   }
1759 }
1760 
1761 void Sema::diagnoseNullResettableSynthesizedSetters(ObjCImplDecl *impDecl) {
1762   for (const auto *propertyImpl : impDecl->property_impls()) {
1763     const auto *property = propertyImpl->getPropertyDecl();
1764 
1765     // Warn about null_resettable properties with synthesized setters,
1766     // because the setter won't properly handle nil.
1767     if (propertyImpl->getPropertyImplementation()
1768           == ObjCPropertyImplDecl::Synthesize &&
1769         (property->getPropertyAttributes() &
1770          ObjCPropertyDecl::OBJC_PR_null_resettable) &&
1771         property->getGetterMethodDecl() &&
1772         property->getSetterMethodDecl()) {
1773       auto *getterMethod = property->getGetterMethodDecl();
1774       auto *setterMethod = property->getSetterMethodDecl();
1775       if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
1776           !impDecl->getInstanceMethod(getterMethod->getSelector())) {
1777         SourceLocation loc = propertyImpl->getLocation();
1778         if (loc.isInvalid())
1779           loc = impDecl->getLocStart();
1780 
1781         Diag(loc, diag::warn_null_resettable_setter)
1782           << setterMethod->getSelector() << property->getDeclName();
1783       }
1784     }
1785   }
1786 }
1787 
1788 void
1789 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
1790                                        ObjCContainerDecl* IDecl) {
1791   // Rules apply in non-GC mode only
1792   if (getLangOpts().getGC() != LangOptions::NonGC)
1793     return;
1794   for (const auto *Property : IDecl->properties()) {
1795     ObjCMethodDecl *GetterMethod = nullptr;
1796     ObjCMethodDecl *SetterMethod = nullptr;
1797     bool LookedUpGetterSetter = false;
1798 
1799     unsigned Attributes = Property->getPropertyAttributes();
1800     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
1801 
1802     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
1803         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
1804       GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1805       SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1806       LookedUpGetterSetter = true;
1807       if (GetterMethod) {
1808         Diag(GetterMethod->getLocation(),
1809              diag::warn_default_atomic_custom_getter_setter)
1810           << Property->getIdentifier() << 0;
1811         Diag(Property->getLocation(), diag::note_property_declare);
1812       }
1813       if (SetterMethod) {
1814         Diag(SetterMethod->getLocation(),
1815              diag::warn_default_atomic_custom_getter_setter)
1816           << Property->getIdentifier() << 1;
1817         Diag(Property->getLocation(), diag::note_property_declare);
1818       }
1819     }
1820 
1821     // We only care about readwrite atomic property.
1822     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
1823         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
1824       continue;
1825     if (const ObjCPropertyImplDecl *PIDecl
1826          = IMPDecl->FindPropertyImplDecl(Property->getIdentifier())) {
1827       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
1828         continue;
1829       if (!LookedUpGetterSetter) {
1830         GetterMethod = IMPDecl->getInstanceMethod(Property->getGetterName());
1831         SetterMethod = IMPDecl->getInstanceMethod(Property->getSetterName());
1832       }
1833       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
1834         SourceLocation MethodLoc =
1835           (GetterMethod ? GetterMethod->getLocation()
1836                         : SetterMethod->getLocation());
1837         Diag(MethodLoc, diag::warn_atomic_property_rule)
1838           << Property->getIdentifier() << (GetterMethod != nullptr)
1839           << (SetterMethod != nullptr);
1840         // fixit stuff.
1841         if (!AttributesAsWritten) {
1842           if (Property->getLParenLoc().isValid()) {
1843             // @property () ... case.
1844             SourceRange PropSourceRange(Property->getAtLoc(),
1845                                         Property->getLParenLoc());
1846             Diag(Property->getLocation(), diag::note_atomic_property_fixup_suggest) <<
1847               FixItHint::CreateReplacement(PropSourceRange, "@property (nonatomic");
1848           }
1849           else {
1850             //@property id etc.
1851             SourceLocation endLoc =
1852               Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
1853             endLoc = endLoc.getLocWithOffset(-1);
1854             SourceRange PropSourceRange(Property->getAtLoc(), endLoc);
1855             Diag(Property->getLocation(), diag::note_atomic_property_fixup_suggest) <<
1856               FixItHint::CreateReplacement(PropSourceRange, "@property (nonatomic) ");
1857           }
1858         }
1859         else if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
1860           // @property () ... case.
1861           SourceLocation endLoc = Property->getLParenLoc();
1862           SourceRange PropSourceRange(Property->getAtLoc(), endLoc);
1863           Diag(Property->getLocation(), diag::note_atomic_property_fixup_suggest) <<
1864            FixItHint::CreateReplacement(PropSourceRange, "@property (nonatomic, ");
1865         }
1866         else
1867           Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
1868         Diag(Property->getLocation(), diag::note_property_declare);
1869       }
1870     }
1871   }
1872 }
1873 
1874 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
1875   if (getLangOpts().getGC() == LangOptions::GCOnly)
1876     return;
1877 
1878   for (const auto *PID : D->property_impls()) {
1879     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
1880     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
1881         !D->getInstanceMethod(PD->getGetterName())) {
1882       ObjCMethodDecl *method = PD->getGetterMethodDecl();
1883       if (!method)
1884         continue;
1885       ObjCMethodFamily family = method->getMethodFamily();
1886       if (family == OMF_alloc || family == OMF_copy ||
1887           family == OMF_mutableCopy || family == OMF_new) {
1888         if (getLangOpts().ObjCAutoRefCount)
1889           Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
1890         else
1891           Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
1892 
1893         // Look for a getter explicitly declared alongside the property.
1894         // If we find one, use its location for the note.
1895         SourceLocation noteLoc = PD->getLocation();
1896         SourceLocation fixItLoc;
1897         for (auto *getterRedecl : method->redecls()) {
1898           if (getterRedecl->isImplicit())
1899             continue;
1900           if (getterRedecl->getDeclContext() != PD->getDeclContext())
1901             continue;
1902           noteLoc = getterRedecl->getLocation();
1903           fixItLoc = getterRedecl->getLocEnd();
1904         }
1905 
1906         Preprocessor &PP = getPreprocessor();
1907         TokenValue tokens[] = {
1908           tok::kw___attribute, tok::l_paren, tok::l_paren,
1909           PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
1910           PP.getIdentifierInfo("none"), tok::r_paren,
1911           tok::r_paren, tok::r_paren
1912         };
1913         StringRef spelling = "__attribute__((objc_method_family(none)))";
1914         StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
1915         if (!macroName.empty())
1916           spelling = macroName;
1917 
1918         auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
1919             << method->getDeclName() << spelling;
1920         if (fixItLoc.isValid()) {
1921           SmallString<64> fixItText(" ");
1922           fixItText += spelling;
1923           noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
1924         }
1925       }
1926     }
1927   }
1928 }
1929 
1930 void Sema::DiagnoseMissingDesignatedInitOverrides(
1931                                             const ObjCImplementationDecl *ImplD,
1932                                             const ObjCInterfaceDecl *IFD) {
1933   assert(IFD->hasDesignatedInitializers());
1934   const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
1935   if (!SuperD)
1936     return;
1937 
1938   SelectorSet InitSelSet;
1939   for (const auto *I : ImplD->instance_methods())
1940     if (I->getMethodFamily() == OMF_init)
1941       InitSelSet.insert(I->getSelector());
1942 
1943   SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
1944   SuperD->getDesignatedInitializers(DesignatedInits);
1945   for (SmallVector<const ObjCMethodDecl *, 8>::iterator
1946          I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
1947     const ObjCMethodDecl *MD = *I;
1948     if (!InitSelSet.count(MD->getSelector())) {
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 /// AddPropertyAttrs - Propagates attributes from a property to the
1958 /// implicitly-declared getter or setter for that property.
1959 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
1960                              ObjCPropertyDecl *Property) {
1961   // Should we just clone all attributes over?
1962   for (const auto *A : Property->attrs()) {
1963     if (isa<DeprecatedAttr>(A) ||
1964         isa<UnavailableAttr>(A) ||
1965         isa<AvailabilityAttr>(A))
1966       PropertyMethod->addAttr(A->clone(S.Context));
1967   }
1968 }
1969 
1970 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
1971 /// have the property type and issue diagnostics if they don't.
1972 /// Also synthesize a getter/setter method if none exist (and update the
1973 /// appropriate lookup tables. FIXME: Should reconsider if adding synthesized
1974 /// methods is the "right" thing to do.
1975 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property,
1976                                ObjCContainerDecl *CD,
1977                                ObjCPropertyDecl *redeclaredProperty,
1978                                ObjCContainerDecl *lexicalDC) {
1979 
1980   ObjCMethodDecl *GetterMethod, *SetterMethod;
1981 
1982   if (CD->isInvalidDecl())
1983     return;
1984 
1985   GetterMethod = CD->getInstanceMethod(property->getGetterName());
1986   SetterMethod = CD->getInstanceMethod(property->getSetterName());
1987   DiagnosePropertyAccessorMismatch(property, GetterMethod,
1988                                    property->getLocation());
1989 
1990   if (SetterMethod) {
1991     ObjCPropertyDecl::PropertyAttributeKind CAttr =
1992       property->getPropertyAttributes();
1993     if ((!(CAttr & ObjCPropertyDecl::OBJC_PR_readonly)) &&
1994         Context.getCanonicalType(SetterMethod->getReturnType()) !=
1995             Context.VoidTy)
1996       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
1997     if (SetterMethod->param_size() != 1 ||
1998         !Context.hasSameUnqualifiedType(
1999           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2000           property->getType().getNonReferenceType())) {
2001       Diag(property->getLocation(),
2002            diag::warn_accessor_property_type_mismatch)
2003         << property->getDeclName()
2004         << SetterMethod->getSelector();
2005       Diag(SetterMethod->getLocation(), diag::note_declared_at);
2006     }
2007   }
2008 
2009   // Synthesize getter/setter methods if none exist.
2010   // Find the default getter and if one not found, add one.
2011   // FIXME: The synthesized property we set here is misleading. We almost always
2012   // synthesize these methods unless the user explicitly provided prototypes
2013   // (which is odd, but allowed). Sema should be typechecking that the
2014   // declarations jive in that situation (which it is not currently).
2015   if (!GetterMethod) {
2016     // No instance method of same name as property getter name was found.
2017     // Declare a getter method and add it to the list of methods
2018     // for this class.
2019     SourceLocation Loc = redeclaredProperty ?
2020       redeclaredProperty->getLocation() :
2021       property->getLocation();
2022 
2023     // If the property is null_resettable, the getter returns nonnull.
2024     QualType resultTy = property->getType();
2025     if (property->getPropertyAttributes() &
2026         ObjCPropertyDecl::OBJC_PR_null_resettable) {
2027       QualType modifiedTy = resultTy;
2028       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2029         if (*nullability == NullabilityKind::Unspecified)
2030           resultTy = Context.getAttributedType(AttributedType::attr_nonnull,
2031                                                modifiedTy, modifiedTy);
2032       }
2033     }
2034 
2035     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
2036                              property->getGetterName(),
2037                              resultTy, nullptr, CD,
2038                              /*isInstance=*/true, /*isVariadic=*/false,
2039                              /*isPropertyAccessor=*/true,
2040                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2041                              (property->getPropertyImplementation() ==
2042                               ObjCPropertyDecl::Optional) ?
2043                              ObjCMethodDecl::Optional :
2044                              ObjCMethodDecl::Required);
2045     CD->addDecl(GetterMethod);
2046 
2047     AddPropertyAttrs(*this, GetterMethod, property);
2048 
2049     // FIXME: Eventually this shouldn't be needed, as the lexical context
2050     // and the real context should be the same.
2051     if (lexicalDC)
2052       GetterMethod->setLexicalDeclContext(lexicalDC);
2053     if (property->hasAttr<NSReturnsNotRetainedAttr>())
2054       GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2055                                                                      Loc));
2056 
2057     if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2058       GetterMethod->addAttr(
2059         ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2060 
2061     if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2062       GetterMethod->addAttr(
2063           SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2064                                       SA->getName(), Loc));
2065 
2066     if (getLangOpts().ObjCAutoRefCount)
2067       CheckARCMethodDecl(GetterMethod);
2068   } else
2069     // A user declared getter will be synthesize when @synthesize of
2070     // the property with the same name is seen in the @implementation
2071     GetterMethod->setPropertyAccessor(true);
2072   property->setGetterMethodDecl(GetterMethod);
2073 
2074   // Skip setter if property is read-only.
2075   if (!property->isReadOnly()) {
2076     // Find the default setter and if one not found, add one.
2077     if (!SetterMethod) {
2078       // No instance method of same name as property setter name was found.
2079       // Declare a setter method and add it to the list of methods
2080       // for this class.
2081       SourceLocation Loc = redeclaredProperty ?
2082         redeclaredProperty->getLocation() :
2083         property->getLocation();
2084 
2085       SetterMethod =
2086         ObjCMethodDecl::Create(Context, Loc, Loc,
2087                                property->getSetterName(), Context.VoidTy,
2088                                nullptr, CD, /*isInstance=*/true,
2089                                /*isVariadic=*/false,
2090                                /*isPropertyAccessor=*/true,
2091                                /*isImplicitlyDeclared=*/true,
2092                                /*isDefined=*/false,
2093                                (property->getPropertyImplementation() ==
2094                                 ObjCPropertyDecl::Optional) ?
2095                                 ObjCMethodDecl::Optional :
2096                                 ObjCMethodDecl::Required);
2097 
2098       // If the property is null_resettable, the setter accepts a
2099       // nullable value.
2100       QualType paramTy = property->getType().getUnqualifiedType();
2101       if (property->getPropertyAttributes() &
2102           ObjCPropertyDecl::OBJC_PR_null_resettable) {
2103         QualType modifiedTy = paramTy;
2104         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2105           if (*nullability == NullabilityKind::Unspecified)
2106             paramTy = Context.getAttributedType(AttributedType::attr_nullable,
2107                                                 modifiedTy, modifiedTy);
2108         }
2109       }
2110 
2111       // Invent the arguments for the setter. We don't bother making a
2112       // nice name for the argument.
2113       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2114                                                   Loc, Loc,
2115                                                   property->getIdentifier(),
2116                                                   paramTy,
2117                                                   /*TInfo=*/nullptr,
2118                                                   SC_None,
2119                                                   nullptr);
2120       SetterMethod->setMethodParams(Context, Argument, None);
2121 
2122       AddPropertyAttrs(*this, SetterMethod, property);
2123 
2124       CD->addDecl(SetterMethod);
2125       // FIXME: Eventually this shouldn't be needed, as the lexical context
2126       // and the real context should be the same.
2127       if (lexicalDC)
2128         SetterMethod->setLexicalDeclContext(lexicalDC);
2129       if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2130         SetterMethod->addAttr(
2131             SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2132                                         SA->getName(), Loc));
2133       // It's possible for the user to have set a very odd custom
2134       // setter selector that causes it to have a method family.
2135       if (getLangOpts().ObjCAutoRefCount)
2136         CheckARCMethodDecl(SetterMethod);
2137     } else
2138       // A user declared setter will be synthesize when @synthesize of
2139       // the property with the same name is seen in the @implementation
2140       SetterMethod->setPropertyAccessor(true);
2141     property->setSetterMethodDecl(SetterMethod);
2142   }
2143   // Add any synthesized methods to the global pool. This allows us to
2144   // handle the following, which is supported by GCC (and part of the design).
2145   //
2146   // @interface Foo
2147   // @property double bar;
2148   // @end
2149   //
2150   // void thisIsUnfortunate() {
2151   //   id foo;
2152   //   double bar = [foo bar];
2153   // }
2154   //
2155   if (GetterMethod)
2156     AddInstanceMethodToGlobalPool(GetterMethod);
2157   if (SetterMethod)
2158     AddInstanceMethodToGlobalPool(SetterMethod);
2159 
2160   ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2161   if (!CurrentClass) {
2162     if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2163       CurrentClass = Cat->getClassInterface();
2164     else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2165       CurrentClass = Impl->getClassInterface();
2166   }
2167   if (GetterMethod)
2168     CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2169   if (SetterMethod)
2170     CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2171 }
2172 
2173 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2174                                        SourceLocation Loc,
2175                                        unsigned &Attributes,
2176                                        bool propertyInPrimaryClass) {
2177   // FIXME: Improve the reported location.
2178   if (!PDecl || PDecl->isInvalidDecl())
2179     return;
2180 
2181   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2182       (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
2183     Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2184     << "readonly" << "readwrite";
2185 
2186   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2187   QualType PropertyTy = PropertyDecl->getType();
2188   unsigned PropertyOwnership = getOwnershipRule(Attributes);
2189 
2190   // 'readonly' property with no obvious lifetime.
2191   // its life time will be determined by its backing ivar.
2192   if (getLangOpts().ObjCAutoRefCount &&
2193       Attributes & ObjCDeclSpec::DQ_PR_readonly &&
2194       PropertyTy->isObjCRetainableType() &&
2195       !PropertyOwnership)
2196     return;
2197 
2198   // Check for copy or retain on non-object types.
2199   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
2200                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
2201       !PropertyTy->isObjCRetainableType() &&
2202       !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2203     Diag(Loc, diag::err_objc_property_requires_object)
2204       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
2205           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
2206     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
2207                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
2208     PropertyDecl->setInvalidDecl();
2209   }
2210 
2211   // Check for more than one of { assign, copy, retain }.
2212   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
2213     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2214       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2215         << "assign" << "copy";
2216       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2217     }
2218     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2219       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2220         << "assign" << "retain";
2221       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2222     }
2223     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2224       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2225         << "assign" << "strong";
2226       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2227     }
2228     if (getLangOpts().ObjCAutoRefCount  &&
2229         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2230       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2231         << "assign" << "weak";
2232       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2233     }
2234     if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2235       Diag(Loc, diag::warn_iboutletcollection_property_assign);
2236   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
2237     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2238       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2239         << "unsafe_unretained" << "copy";
2240       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2241     }
2242     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2243       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2244         << "unsafe_unretained" << "retain";
2245       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2246     }
2247     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2248       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2249         << "unsafe_unretained" << "strong";
2250       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2251     }
2252     if (getLangOpts().ObjCAutoRefCount  &&
2253         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2254       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2255         << "unsafe_unretained" << "weak";
2256       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2257     }
2258   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2259     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2260       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2261         << "copy" << "retain";
2262       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2263     }
2264     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2265       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2266         << "copy" << "strong";
2267       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2268     }
2269     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2270       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2271         << "copy" << "weak";
2272       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2273     }
2274   }
2275   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2276            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2277       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2278         << "retain" << "weak";
2279       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2280   }
2281   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2282            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2283       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2284         << "strong" << "weak";
2285       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2286   }
2287 
2288   if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2289     // 'weak' and 'nonnull' are mutually exclusive.
2290     if (auto nullability = PropertyTy->getNullability(Context)) {
2291       if (*nullability == NullabilityKind::NonNull)
2292         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2293           << "nonnull" << "weak";
2294     } else {
2295         PropertyTy =
2296           Context.getAttributedType(
2297             AttributedType::getNullabilityAttrKind(NullabilityKind::Nullable),
2298             PropertyTy, PropertyTy);
2299         TypeSourceInfo *TSInfo = PropertyDecl->getTypeSourceInfo();
2300         PropertyDecl->setType(PropertyTy, TSInfo);
2301     }
2302   }
2303 
2304   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
2305       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
2306       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2307         << "atomic" << "nonatomic";
2308       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
2309   }
2310 
2311   // Warn if user supplied no assignment attribute, property is
2312   // readwrite, and this is an object type.
2313   if (!(Attributes & (ObjCDeclSpec::DQ_PR_assign | ObjCDeclSpec::DQ_PR_copy |
2314                       ObjCDeclSpec::DQ_PR_unsafe_unretained |
2315                       ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong |
2316                       ObjCDeclSpec::DQ_PR_weak)) &&
2317       PropertyTy->isObjCObjectPointerType()) {
2318       if (getLangOpts().ObjCAutoRefCount)
2319         // With arc,  @property definitions should default to (strong) when
2320         // not specified; including when property is 'readonly'.
2321         PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
2322       else if (!(Attributes & ObjCDeclSpec::DQ_PR_readonly)) {
2323         bool isAnyClassTy =
2324           (PropertyTy->isObjCClassType() ||
2325            PropertyTy->isObjCQualifiedClassType());
2326         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2327         // issue any warning.
2328         if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2329           ;
2330         else if (propertyInPrimaryClass) {
2331           // Don't issue warning on property with no life time in class
2332           // extension as it is inherited from property in primary class.
2333           // Skip this warning in gc-only mode.
2334           if (getLangOpts().getGC() != LangOptions::GCOnly)
2335             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2336 
2337           // If non-gc code warn that this is likely inappropriate.
2338           if (getLangOpts().getGC() == LangOptions::NonGC)
2339             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2340         }
2341       }
2342 
2343     // FIXME: Implement warning dependent on NSCopying being
2344     // implemented. See also:
2345     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2346     // (please trim this list while you are at it).
2347   }
2348 
2349   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
2350       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
2351       && getLangOpts().getGC() == LangOptions::GCOnly
2352       && PropertyTy->isBlockPointerType())
2353     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2354   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2355            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2356            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2357            PropertyTy->isBlockPointerType())
2358       Diag(Loc, diag::warn_objc_property_retain_of_block);
2359 
2360   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2361       (Attributes & ObjCDeclSpec::DQ_PR_setter))
2362     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2363 
2364 }
2365