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