contrib/llvm-project/clang/lib/Sema/SemaObjCProperty.cpp

   1 //===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file implements semantic analysis for Objective C @property and
  10 //  @synthesize declarations.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Sema/SemaInternal.h"
  15 #include "clang/AST/ASTMutationListener.h"
  16 #include "clang/AST/DeclObjC.h"
  17 #include "clang/AST/ExprCXX.h"
  18 #include "clang/AST/ExprObjC.h"
  19 #include "clang/Basic/SourceManager.h"
  20 #include "clang/Lex/Lexer.h"
  21 #include "clang/Lex/Preprocessor.h"
  22 #include "clang/Sema/Initialization.h"
  23 #include "llvm/ADT/DenseSet.h"
  24 #include "llvm/ADT/SmallString.h"
  25
  26 using namespace clang;
  27
  28 //===----------------------------------------------------------------------===//
  29 // Grammar actions.
  30 //===----------------------------------------------------------------------===//
  31
  32 /// getImpliedARCOwnership - Given a set of property attributes and a
  33 /// type, infer an expected lifetime.  The type's ownership qualification
  34 /// is not considered.
  35 ///
  36 /// Returns OCL_None if the attributes as stated do not imply an ownership.
  37 /// Never returns OCL_Autoreleasing.
  38 static Qualifiers::ObjCLifetime getImpliedARCOwnership(
  39                                ObjCPropertyDecl::PropertyAttributeKind attrs,
  40                                                 QualType type) {
  41   // retain, strong, copy, weak, and unsafe_unretained are only legal
  42   // on properties of retainable pointer type.
  43   if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
  44                ObjCPropertyDecl::OBJC_PR_strong |
  45                ObjCPropertyDecl::OBJC_PR_copy)) {
  46     return Qualifiers::OCL_Strong;
  47   } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
  48     return Qualifiers::OCL_Weak;
  49   } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
  50     return Qualifiers::OCL_ExplicitNone;
  51   }
  52
  53   // assign can appear on other types, so we have to check the
  54   // property type.
  55   if (attrs & ObjCPropertyDecl::OBJC_PR_assign &&
  56       type->isObjCRetainableType()) {
  57     return Qualifiers::OCL_ExplicitNone;
  58   }
  59
  60   return Qualifiers::OCL_None;
  61 }
  62
  63 /// Check the internal consistency of a property declaration with
  64 /// an explicit ownership qualifier.
  65 static void checkPropertyDeclWithOwnership(Sema &S,
  66                                            ObjCPropertyDecl *property) {
  67   if (property->isInvalidDecl()) return;
  68
  69   ObjCPropertyDecl::PropertyAttributeKind propertyKind
  70     = property->getPropertyAttributes();
  71   Qualifiers::ObjCLifetime propertyLifetime
  72     = property->getType().getObjCLifetime();
  73
  74   assert(propertyLifetime != Qualifiers::OCL_None);
  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 /// Check this Objective-C property against a property declared in the
 107 /// given protocol.
 108 static void
 109 CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
 110                              ObjCProtocolDecl *Proto,
 111                              llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
 112   // Have we seen this protocol before?
 113   if (!Known.insert(Proto).second)
 114     return;
 115
 116   // Look for a property with the same name.
 117   DeclContext::lookup_result R = Proto->lookup(Prop->getDeclName());
 118   for (unsigned I = 0, N = R.size(); I != N; ++I) {
 119     if (ObjCPropertyDecl *ProtoProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
 120       S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
 121       return;
 122     }
 123   }
 124
 125   // Check this property against any protocols we inherit.
 126   for (auto *P : Proto->protocols())
 127     CheckPropertyAgainstProtocol(S, Prop, P, Known);
 128 }
 129
 130 static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
 131   // In GC mode, just look for the __weak qualifier.
 132   if (S.getLangOpts().getGC() != LangOptions::NonGC) {
 133     if (T.isObjCGCWeak()) return ObjCDeclSpec::DQ_PR_weak;
 134
 135   // In ARC/MRC, look for an explicit ownership qualifier.
 136   // For some reason, this only applies to __weak.
 137   } else if (auto ownership = T.getObjCLifetime()) {
 138     switch (ownership) {
 139     case Qualifiers::OCL_Weak:
 140       return ObjCDeclSpec::DQ_PR_weak;
 141     case Qualifiers::OCL_Strong:
 142       return ObjCDeclSpec::DQ_PR_strong;
 143     case Qualifiers::OCL_ExplicitNone:
 144       return ObjCDeclSpec::DQ_PR_unsafe_unretained;
 145     case Qualifiers::OCL_Autoreleasing:
 146     case Qualifiers::OCL_None:
 147       return 0;
 148     }
 149     llvm_unreachable("bad qualifier");
 150   }
 151
 152   return 0;
 153 }
 154
 155 static const unsigned OwnershipMask =
 156   (ObjCPropertyDecl::OBJC_PR_assign |
 157    ObjCPropertyDecl::OBJC_PR_retain |
 158    ObjCPropertyDecl::OBJC_PR_copy   |
 159    ObjCPropertyDecl::OBJC_PR_weak   |
 160    ObjCPropertyDecl::OBJC_PR_strong |
 161    ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 162
 163 static unsigned getOwnershipRule(unsigned attr) {
 164   unsigned result = attr & OwnershipMask;
 165
 166   // From an ownership perspective, assign and unsafe_unretained are
 167   // identical; make sure one also implies the other.
 168   if (result & (ObjCPropertyDecl::OBJC_PR_assign |
 169                 ObjCPropertyDecl::OBJC_PR_unsafe_unretained)) {
 170     result |= ObjCPropertyDecl::OBJC_PR_assign |
 171               ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
 172   }
 173
 174   return result;
 175 }
 176
 177 Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
 178                           SourceLocation LParenLoc,
 179                           FieldDeclarator &FD,
 180                           ObjCDeclSpec &ODS,
 181                           Selector GetterSel,
 182                           Selector SetterSel,
 183                           tok::ObjCKeywordKind MethodImplKind,
 184                           DeclContext *lexicalDC) {
 185   unsigned Attributes = ODS.getPropertyAttributes();
 186   FD.D.setObjCWeakProperty((Attributes & ObjCDeclSpec::DQ_PR_weak) != 0);
 187   TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
 188   QualType T = TSI->getType();
 189   if (!getOwnershipRule(Attributes)) {
 190     Attributes |= deducePropertyOwnershipFromType(*this, T);
 191   }
 192   bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
 193                       // default is readwrite!
 194                       !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
 195
 196   // Proceed with constructing the ObjCPropertyDecls.
 197   ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
 198   ObjCPropertyDecl *Res = nullptr;
 199   if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
 200     if (CDecl->IsClassExtension()) {
 201       Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
 202                                            FD,
 203                                            GetterSel, ODS.getGetterNameLoc(),
 204                                            SetterSel, ODS.getSetterNameLoc(),
 205                                            isReadWrite, Attributes,
 206                                            ODS.getPropertyAttributes(),
 207                                            T, TSI, MethodImplKind);
 208       if (!Res)
 209         return nullptr;
 210     }
 211   }
 212
 213   if (!Res) {
 214     Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
 215                              GetterSel, ODS.getGetterNameLoc(), SetterSel,
 216                              ODS.getSetterNameLoc(), isReadWrite, Attributes,
 217                              ODS.getPropertyAttributes(), T, TSI,
 218                              MethodImplKind);
 219     if (lexicalDC)
 220       Res->setLexicalDeclContext(lexicalDC);
 221   }
 222
 223   // Validate the attributes on the @property.
 224   CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
 225                               (isa<ObjCInterfaceDecl>(ClassDecl) ||
 226                                isa<ObjCProtocolDecl>(ClassDecl)));
 227
 228   // Check consistency if the type has explicit ownership qualification.
 229   if (Res->getType().getObjCLifetime())
 230     checkPropertyDeclWithOwnership(*this, Res);
 231
 232   llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
 233   if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
 234     // For a class, compare the property against a property in our superclass.
 235     bool FoundInSuper = false;
 236     ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
 237     while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
 238       DeclContext::lookup_result R = Super->lookup(Res->getDeclName());
 239       for (unsigned I = 0, N = R.size(); I != N; ++I) {
 240         if (ObjCPropertyDecl *SuperProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
 241           DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
 242           FoundInSuper = true;
 243           break;
 244         }
 245       }
 246       if (FoundInSuper)
 247         break;
 248       else
 249         CurrentInterfaceDecl = Super;
 250     }
 251
 252     if (FoundInSuper) {
 253       // Also compare the property against a property in our protocols.
 254       for (auto *P : CurrentInterfaceDecl->protocols()) {
 255         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 256       }
 257     } else {
 258       // Slower path: look in all protocols we referenced.
 259       for (auto *P : IFace->all_referenced_protocols()) {
 260         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 261       }
 262     }
 263   } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
 264     // We don't check if class extension. Because properties in class extension
 265     // are meant to override some of the attributes and checking has already done
 266     // when property in class extension is constructed.
 267     if (!Cat->IsClassExtension())
 268       for (auto *P : Cat->protocols())
 269         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 270   } else {
 271     ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
 272     for (auto *P : Proto->protocols())
 273       CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 274   }
 275
 276   ActOnDocumentableDecl(Res);
 277   return Res;
 278 }
 279
 280 static ObjCPropertyDecl::PropertyAttributeKind
 281 makePropertyAttributesAsWritten(unsigned Attributes) {
 282   unsigned attributesAsWritten = 0;
 283   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
 284     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
 285   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
 286     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
 287   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
 288     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
 289   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
 290     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
 291   if (Attributes & ObjCDeclSpec::DQ_PR_assign)
 292     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
 293   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
 294     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
 295   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
 296     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
 297   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
 298     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
 299   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
 300     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
 301   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 302     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
 303   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
 304     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
 305   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
 306     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
 307   if (Attributes & ObjCDeclSpec::DQ_PR_class)
 308     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_class;
 309
 310   return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
 311 }
 312
 313 static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
 314                                  SourceLocation LParenLoc, SourceLocation &Loc) {
 315   if (LParenLoc.isMacroID())
 316     return false;
 317
 318   SourceManager &SM = Context.getSourceManager();
 319   std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
 320   // Try to load the file buffer.
 321   bool invalidTemp = false;
 322   StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
 323   if (invalidTemp)
 324     return false;
 325   const char *tokenBegin = file.data() + locInfo.second;
 326
 327   // Lex from the start of the given location.
 328   Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
 329               Context.getLangOpts(),
 330               file.begin(), tokenBegin, file.end());
 331   Token Tok;
 332   do {
 333     lexer.LexFromRawLexer(Tok);
 334     if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
 335       Loc = Tok.getLocation();
 336       return true;
 337     }
 338   } while (Tok.isNot(tok::r_paren));
 339   return false;
 340 }
 341
 342 /// Check for a mismatch in the atomicity of the given properties.
 343 static void checkAtomicPropertyMismatch(Sema &S,
 344                                         ObjCPropertyDecl *OldProperty,
 345                                         ObjCPropertyDecl *NewProperty,
 346                                         bool PropagateAtomicity) {
 347   // If the atomicity of both matches, we're done.
 348   bool OldIsAtomic =
 349     (OldProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
 350       == 0;
 351   bool NewIsAtomic =
 352     (NewProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
 353       == 0;
 354   if (OldIsAtomic == NewIsAtomic) return;
 355
 356   // Determine whether the given property is readonly and implicitly
 357   // atomic.
 358   auto isImplicitlyReadonlyAtomic = [](ObjCPropertyDecl *Property) -> bool {
 359     // Is it readonly?
 360     auto Attrs = Property->getPropertyAttributes();
 361     if ((Attrs & ObjCPropertyDecl::OBJC_PR_readonly) == 0) return false;
 362
 363     // Is it nonatomic?
 364     if (Attrs & ObjCPropertyDecl::OBJC_PR_nonatomic) return false;
 365
 366     // Was 'atomic' specified directly?
 367     if (Property->getPropertyAttributesAsWritten() &
 368           ObjCPropertyDecl::OBJC_PR_atomic)
 369       return false;
 370
 371     return true;
 372   };
 373
 374   // If we're allowed to propagate atomicity, and the new property did
 375   // not specify atomicity at all, propagate.
 376   const unsigned AtomicityMask =
 377     (ObjCPropertyDecl::OBJC_PR_atomic | ObjCPropertyDecl::OBJC_PR_nonatomic);
 378   if (PropagateAtomicity &&
 379       ((NewProperty->getPropertyAttributesAsWritten() & AtomicityMask) == 0)) {
 380     unsigned Attrs = NewProperty->getPropertyAttributes();
 381     Attrs = Attrs & ~AtomicityMask;
 382     if (OldIsAtomic)
 383       Attrs |= ObjCPropertyDecl::OBJC_PR_atomic;
 384     else
 385       Attrs |= ObjCPropertyDecl::OBJC_PR_nonatomic;
 386
 387     NewProperty->overwritePropertyAttributes(Attrs);
 388     return;
 389   }
 390
 391   // One of the properties is atomic; if it's a readonly property, and
 392   // 'atomic' wasn't explicitly specified, we're okay.
 393   if ((OldIsAtomic && isImplicitlyReadonlyAtomic(OldProperty)) ||
 394       (NewIsAtomic && isImplicitlyReadonlyAtomic(NewProperty)))
 395     return;
 396
 397   // Diagnose the conflict.
 398   const IdentifierInfo *OldContextName;
 399   auto *OldDC = OldProperty->getDeclContext();
 400   if (auto Category = dyn_cast<ObjCCategoryDecl>(OldDC))
 401     OldContextName = Category->getClassInterface()->getIdentifier();
 402   else
 403     OldContextName = cast<ObjCContainerDecl>(OldDC)->getIdentifier();
 404
 405   S.Diag(NewProperty->getLocation(), diag::warn_property_attribute)
 406     << NewProperty->getDeclName() << "atomic"
 407     << OldContextName;
 408   S.Diag(OldProperty->getLocation(), diag::note_property_declare);
 409 }
 410
 411 ObjCPropertyDecl *
 412 Sema::HandlePropertyInClassExtension(Scope *S,
 413                                      SourceLocation AtLoc,
 414                                      SourceLocation LParenLoc,
 415                                      FieldDeclarator &FD,
 416                                      Selector GetterSel,
 417                                      SourceLocation GetterNameLoc,
 418                                      Selector SetterSel,
 419                                      SourceLocation SetterNameLoc,
 420                                      const bool isReadWrite,
 421                                      unsigned &Attributes,
 422                                      const unsigned AttributesAsWritten,
 423                                      QualType T,
 424                                      TypeSourceInfo *TSI,
 425                                      tok::ObjCKeywordKind MethodImplKind) {
 426   ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
 427   // Diagnose if this property is already in continuation class.
 428   DeclContext *DC = CurContext;
 429   IdentifierInfo *PropertyId = FD.D.getIdentifier();
 430   ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
 431
 432   // We need to look in the @interface to see if the @property was
 433   // already declared.
 434   if (!CCPrimary) {
 435     Diag(CDecl->getLocation(), diag::err_continuation_class);
 436     return nullptr;
 437   }
 438
 439   bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
 440                          (Attributes & ObjCDeclSpec::DQ_PR_class);
 441
 442   // Find the property in the extended class's primary class or
 443   // extensions.
 444   ObjCPropertyDecl *PIDecl = CCPrimary->FindPropertyVisibleInPrimaryClass(
 445       PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty));
 446
 447   // If we found a property in an extension, complain.
 448   if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
 449     Diag(AtLoc, diag::err_duplicate_property);
 450     Diag(PIDecl->getLocation(), diag::note_property_declare);
 451     return nullptr;
 452   }
 453
 454   // Check for consistency with the previous declaration, if there is one.
 455   if (PIDecl) {
 456     // A readonly property declared in the primary class can be refined
 457     // by adding a readwrite property within an extension.
 458     // Anything else is an error.
 459     if (!(PIDecl->isReadOnly() && isReadWrite)) {
 460       // Tailor the diagnostics for the common case where a readwrite
 461       // property is declared both in the @interface and the continuation.
 462       // This is a common error where the user often intended the original
 463       // declaration to be readonly.
 464       unsigned diag =
 465         (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
 466         (PIDecl->getPropertyAttributesAsWritten() &
 467            ObjCPropertyDecl::OBJC_PR_readwrite)
 468         ? diag::err_use_continuation_class_redeclaration_readwrite
 469         : diag::err_use_continuation_class;
 470       Diag(AtLoc, diag)
 471         << CCPrimary->getDeclName();
 472       Diag(PIDecl->getLocation(), diag::note_property_declare);
 473       return nullptr;
 474     }
 475
 476     // Check for consistency of getters.
 477     if (PIDecl->getGetterName() != GetterSel) {
 478      // If the getter was written explicitly, complain.
 479       if (AttributesAsWritten & ObjCDeclSpec::DQ_PR_getter) {
 480         Diag(AtLoc, diag::warn_property_redecl_getter_mismatch)
 481           << PIDecl->getGetterName() << GetterSel;
 482         Diag(PIDecl->getLocation(), diag::note_property_declare);
 483       }
 484
 485       // Always adopt the getter from the original declaration.
 486       GetterSel = PIDecl->getGetterName();
 487       Attributes |= ObjCDeclSpec::DQ_PR_getter;
 488     }
 489
 490     // Check consistency of ownership.
 491     unsigned ExistingOwnership
 492       = getOwnershipRule(PIDecl->getPropertyAttributes());
 493     unsigned NewOwnership = getOwnershipRule(Attributes);
 494     if (ExistingOwnership && NewOwnership != ExistingOwnership) {
 495       // If the ownership was written explicitly, complain.
 496       if (getOwnershipRule(AttributesAsWritten)) {
 497         Diag(AtLoc, diag::warn_property_attr_mismatch);
 498         Diag(PIDecl->getLocation(), diag::note_property_declare);
 499       }
 500
 501       // Take the ownership from the original property.
 502       Attributes = (Attributes & ~OwnershipMask) | ExistingOwnership;
 503     }
 504
 505     // If the redeclaration is 'weak' but the original property is not,
 506     if ((Attributes & ObjCPropertyDecl::OBJC_PR_weak) &&
 507         !(PIDecl->getPropertyAttributesAsWritten()
 508             & ObjCPropertyDecl::OBJC_PR_weak) &&
 509         PIDecl->getType()->getAs<ObjCObjectPointerType>() &&
 510         PIDecl->getType().getObjCLifetime() == Qualifiers::OCL_None) {
 511       Diag(AtLoc, diag::warn_property_implicitly_mismatched);
 512       Diag(PIDecl->getLocation(), diag::note_property_declare);
 513     }
 514   }
 515
 516   // Create a new ObjCPropertyDecl with the DeclContext being
 517   // the class extension.
 518   ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
 519                                                FD, GetterSel, GetterNameLoc,
 520                                                SetterSel, SetterNameLoc,
 521                                                isReadWrite,
 522                                                Attributes, AttributesAsWritten,
 523                                                T, TSI, MethodImplKind, DC);
 524
 525   // If there was no declaration of a property with the same name in
 526   // the primary class, we're done.
 527   if (!PIDecl) {
 528     ProcessPropertyDecl(PDecl);
 529     return PDecl;
 530   }
 531
 532   if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
 533     bool IncompatibleObjC = false;
 534     QualType ConvertedType;
 535     // Relax the strict type matching for property type in continuation class.
 536     // Allow property object type of continuation class to be different as long
 537     // as it narrows the object type in its primary class property. Note that
 538     // this conversion is safe only because the wider type is for a 'readonly'
 539     // property in primary class and 'narrowed' type for a 'readwrite' property
 540     // in continuation class.
 541     QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
 542     QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
 543     if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
 544         !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
 545         (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
 546                                   ConvertedType, IncompatibleObjC))
 547         || IncompatibleObjC) {
 548       Diag(AtLoc,
 549           diag::err_type_mismatch_continuation_class) << PDecl->getType();
 550       Diag(PIDecl->getLocation(), diag::note_property_declare);
 551       return nullptr;
 552     }
 553   }
 554
 555   // Check that atomicity of property in class extension matches the previous
 556   // declaration.
 557   checkAtomicPropertyMismatch(*this, PIDecl, PDecl, true);
 558
 559   // Make sure getter/setter are appropriately synthesized.
 560   ProcessPropertyDecl(PDecl);
 561   return PDecl;
 562 }
 563
 564 ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
 565                                            ObjCContainerDecl *CDecl,
 566                                            SourceLocation AtLoc,
 567                                            SourceLocation LParenLoc,
 568                                            FieldDeclarator &FD,
 569                                            Selector GetterSel,
 570                                            SourceLocation GetterNameLoc,
 571                                            Selector SetterSel,
 572                                            SourceLocation SetterNameLoc,
 573                                            const bool isReadWrite,
 574                                            const unsigned Attributes,
 575                                            const unsigned AttributesAsWritten,
 576                                            QualType T,
 577                                            TypeSourceInfo *TInfo,
 578                                            tok::ObjCKeywordKind MethodImplKind,
 579                                            DeclContext *lexicalDC){
 580   IdentifierInfo *PropertyId = FD.D.getIdentifier();
 581
 582   // Property defaults to 'assign' if it is readwrite, unless this is ARC
 583   // and the type is retainable.
 584   bool isAssign;
 585   if (Attributes & (ObjCDeclSpec::DQ_PR_assign |
 586                     ObjCDeclSpec::DQ_PR_unsafe_unretained)) {
 587     isAssign = true;
 588   } else if (getOwnershipRule(Attributes) || !isReadWrite) {
 589     isAssign = false;
 590   } else {
 591     isAssign = (!getLangOpts().ObjCAutoRefCount ||
 592                 !T->isObjCRetainableType());
 593   }
 594
 595   // Issue a warning if property is 'assign' as default and its
 596   // object, which is gc'able conforms to NSCopying protocol
 597   if (getLangOpts().getGC() != LangOptions::NonGC &&
 598       isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign)) {
 599     if (const ObjCObjectPointerType *ObjPtrTy =
 600           T->getAs<ObjCObjectPointerType>()) {
 601       ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
 602       if (IDecl)
 603         if (ObjCProtocolDecl* PNSCopying =
 604             LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
 605           if (IDecl->ClassImplementsProtocol(PNSCopying, true))
 606             Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
 607     }
 608   }
 609
 610   if (T->isObjCObjectType()) {
 611     SourceLocation StarLoc = TInfo->getTypeLoc().getEndLoc();
 612     StarLoc = getLocForEndOfToken(StarLoc);
 613     Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
 614       << FixItHint::CreateInsertion(StarLoc, "*");
 615     T = Context.getObjCObjectPointerType(T);
 616     SourceLocation TLoc = TInfo->getTypeLoc().getBeginLoc();
 617     TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
 618   }
 619
 620   DeclContext *DC = CDecl;
 621   ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
 622                                                      FD.D.getIdentifierLoc(),
 623                                                      PropertyId, AtLoc,
 624                                                      LParenLoc, T, TInfo);
 625
 626   bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
 627                          (Attributes & ObjCDeclSpec::DQ_PR_class);
 628   // Class property and instance property can have the same name.
 629   if (ObjCPropertyDecl *prevDecl = ObjCPropertyDecl::findPropertyDecl(
 630           DC, PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty))) {
 631     Diag(PDecl->getLocation(), diag::err_duplicate_property);
 632     Diag(prevDecl->getLocation(), diag::note_property_declare);
 633     PDecl->setInvalidDecl();
 634   }
 635   else {
 636     DC->addDecl(PDecl);
 637     if (lexicalDC)
 638       PDecl->setLexicalDeclContext(lexicalDC);
 639   }
 640
 641   if (T->isArrayType() || T->isFunctionType()) {
 642     Diag(AtLoc, diag::err_property_type) << T;
 643     PDecl->setInvalidDecl();
 644   }
 645
 646   ProcessDeclAttributes(S, PDecl, FD.D);
 647
 648   // Regardless of setter/getter attribute, we save the default getter/setter
 649   // selector names in anticipation of declaration of setter/getter methods.
 650   PDecl->setGetterName(GetterSel, GetterNameLoc);
 651   PDecl->setSetterName(SetterSel, SetterNameLoc);
 652   PDecl->setPropertyAttributesAsWritten(
 653                           makePropertyAttributesAsWritten(AttributesAsWritten));
 654
 655   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
 656     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
 657
 658   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
 659     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
 660
 661   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
 662     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
 663
 664   if (isReadWrite)
 665     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
 666
 667   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
 668     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
 669
 670   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
 671     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 672
 673   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
 674     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
 675
 676   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
 677     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
 678
 679   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 680     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 681
 682   if (isAssign)
 683     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
 684
 685   // In the semantic attributes, one of nonatomic or atomic is always set.
 686   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
 687     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
 688   else
 689     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
 690
 691   // 'unsafe_unretained' is alias for 'assign'.
 692   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 693     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
 694   if (isAssign)
 695     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 696
 697   if (MethodImplKind == tok::objc_required)
 698     PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
 699   else if (MethodImplKind == tok::objc_optional)
 700     PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
 701
 702   if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
 703     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
 704
 705   if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
 706     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
 707
 708  if (Attributes & ObjCDeclSpec::DQ_PR_class)
 709     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_class);
 710
 711   return PDecl;
 712 }
 713
 714 static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
 715                                  ObjCPropertyDecl *property,
 716                                  ObjCIvarDecl *ivar) {
 717   if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
 718
 719   QualType ivarType = ivar->getType();
 720   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
 721
 722   // The lifetime implied by the property's attributes.
 723   Qualifiers::ObjCLifetime propertyLifetime =
 724     getImpliedARCOwnership(property->getPropertyAttributes(),
 725                            property->getType());
 726
 727   // We're fine if they match.
 728   if (propertyLifetime == ivarLifetime) return;
 729
 730   // None isn't a valid lifetime for an object ivar in ARC, and
 731   // __autoreleasing is never valid; don't diagnose twice.
 732   if ((ivarLifetime == Qualifiers::OCL_None &&
 733        S.getLangOpts().ObjCAutoRefCount) ||
 734       ivarLifetime == Qualifiers::OCL_Autoreleasing)
 735     return;
 736
 737   // If the ivar is private, and it's implicitly __unsafe_unretained
 738   // becaues of its type, then pretend it was actually implicitly
 739   // __strong.  This is only sound because we're processing the
 740   // property implementation before parsing any method bodies.
 741   if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
 742       propertyLifetime == Qualifiers::OCL_Strong &&
 743       ivar->getAccessControl() == ObjCIvarDecl::Private) {
 744     SplitQualType split = ivarType.split();
 745     if (split.Quals.hasObjCLifetime()) {
 746       assert(ivarType->isObjCARCImplicitlyUnretainedType());
 747       split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
 748       ivarType = S.Context.getQualifiedType(split);
 749       ivar->setType(ivarType);
 750       return;
 751     }
 752   }
 753
 754   switch (propertyLifetime) {
 755   case Qualifiers::OCL_Strong:
 756     S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
 757       << property->getDeclName()
 758       << ivar->getDeclName()
 759       << ivarLifetime;
 760     break;
 761
 762   case Qualifiers::OCL_Weak:
 763     S.Diag(ivar->getLocation(), diag::err_weak_property)
 764       << property->getDeclName()
 765       << ivar->getDeclName();
 766     break;
 767
 768   case Qualifiers::OCL_ExplicitNone:
 769     S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
 770       << property->getDeclName()
 771       << ivar->getDeclName()
 772       << ((property->getPropertyAttributesAsWritten()
 773            & ObjCPropertyDecl::OBJC_PR_assign) != 0);
 774     break;
 775
 776   case Qualifiers::OCL_Autoreleasing:
 777     llvm_unreachable("properties cannot be autoreleasing");
 778
 779   case Qualifiers::OCL_None:
 780     // Any other property should be ignored.
 781     return;
 782   }
 783
 784   S.Diag(property->getLocation(), diag::note_property_declare);
 785   if (propertyImplLoc.isValid())
 786     S.Diag(propertyImplLoc, diag::note_property_synthesize);
 787 }
 788
 789 /// setImpliedPropertyAttributeForReadOnlyProperty -
 790 /// This routine evaludates life-time attributes for a 'readonly'
 791 /// property with no known lifetime of its own, using backing
 792 /// 'ivar's attribute, if any. If no backing 'ivar', property's
 793 /// life-time is assumed 'strong'.
 794 static void setImpliedPropertyAttributeForReadOnlyProperty(
 795               ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
 796   Qualifiers::ObjCLifetime propertyLifetime =
 797     getImpliedARCOwnership(property->getPropertyAttributes(),
 798                            property->getType());
 799   if (propertyLifetime != Qualifiers::OCL_None)
 800     return;
 801
 802   if (!ivar) {
 803     // if no backing ivar, make property 'strong'.
 804     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 805     return;
 806   }
 807   // property assumes owenership of backing ivar.
 808   QualType ivarType = ivar->getType();
 809   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
 810   if (ivarLifetime == Qualifiers::OCL_Strong)
 811     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 812   else if (ivarLifetime == Qualifiers::OCL_Weak)
 813     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
 814 }
 815
 816 static bool
 817 isIncompatiblePropertyAttribute(unsigned Attr1, unsigned Attr2,
 818                                 ObjCPropertyDecl::PropertyAttributeKind Kind) {
 819   return (Attr1 & Kind) != (Attr2 & Kind);
 820 }
 821
 822 static bool areIncompatiblePropertyAttributes(unsigned Attr1, unsigned Attr2,
 823                                               unsigned Kinds) {
 824   return ((Attr1 & Kinds) != 0) != ((Attr2 & Kinds) != 0);
 825 }
 826
 827 /// SelectPropertyForSynthesisFromProtocols - Finds the most appropriate
 828 /// property declaration that should be synthesised in all of the inherited
 829 /// protocols. It also diagnoses properties declared in inherited protocols with
 830 /// mismatched types or attributes, since any of them can be candidate for
 831 /// synthesis.
 832 static ObjCPropertyDecl *
 833 SelectPropertyForSynthesisFromProtocols(Sema &S, SourceLocation AtLoc,
 834                                         ObjCInterfaceDecl *ClassDecl,
 835                                         ObjCPropertyDecl *Property) {
 836   assert(isa<ObjCProtocolDecl>(Property->getDeclContext()) &&
 837          "Expected a property from a protocol");
 838   ObjCInterfaceDecl::ProtocolPropertySet ProtocolSet;
 839   ObjCInterfaceDecl::PropertyDeclOrder Properties;
 840   for (const auto *PI : ClassDecl->all_referenced_protocols()) {
 841     if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
 842       PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
 843                                                 Properties);
 844   }
 845   if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass()) {
 846     while (SDecl) {
 847       for (const auto *PI : SDecl->all_referenced_protocols()) {
 848         if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
 849           PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
 850                                                     Properties);
 851       }
 852       SDecl = SDecl->getSuperClass();
 853     }
 854   }
 855
 856   if (Properties.empty())
 857     return Property;
 858
 859   ObjCPropertyDecl *OriginalProperty = Property;
 860   size_t SelectedIndex = 0;
 861   for (const auto &Prop : llvm::enumerate(Properties)) {
 862     // Select the 'readwrite' property if such property exists.
 863     if (Property->isReadOnly() && !Prop.value()->isReadOnly()) {
 864       Property = Prop.value();
 865       SelectedIndex = Prop.index();
 866     }
 867   }
 868   if (Property != OriginalProperty) {
 869     // Check that the old property is compatible with the new one.
 870     Properties[SelectedIndex] = OriginalProperty;
 871   }
 872
 873   QualType RHSType = S.Context.getCanonicalType(Property->getType());
 874   unsigned OriginalAttributes = Property->getPropertyAttributesAsWritten();
 875   enum MismatchKind {
 876     IncompatibleType = 0,
 877     HasNoExpectedAttribute,
 878     HasUnexpectedAttribute,
 879     DifferentGetter,
 880     DifferentSetter
 881   };
 882   // Represents a property from another protocol that conflicts with the
 883   // selected declaration.
 884   struct MismatchingProperty {
 885     const ObjCPropertyDecl *Prop;
 886     MismatchKind Kind;
 887     StringRef AttributeName;
 888   };
 889   SmallVector<MismatchingProperty, 4> Mismatches;
 890   for (ObjCPropertyDecl *Prop : Properties) {
 891     // Verify the property attributes.
 892     unsigned Attr = Prop->getPropertyAttributesAsWritten();
 893     if (Attr != OriginalAttributes) {
 894       auto Diag = [&](bool OriginalHasAttribute, StringRef AttributeName) {
 895         MismatchKind Kind = OriginalHasAttribute ? HasNoExpectedAttribute
 896                                                  : HasUnexpectedAttribute;
 897         Mismatches.push_back({Prop, Kind, AttributeName});
 898       };
 899       // The ownership might be incompatible unless the property has no explicit
 900       // ownership.
 901       bool HasOwnership = (Attr & (ObjCPropertyDecl::OBJC_PR_retain |
 902                                    ObjCPropertyDecl::OBJC_PR_strong |
 903                                    ObjCPropertyDecl::OBJC_PR_copy |
 904                                    ObjCPropertyDecl::OBJC_PR_assign |
 905                                    ObjCPropertyDecl::OBJC_PR_unsafe_unretained |
 906                                    ObjCPropertyDecl::OBJC_PR_weak)) != 0;
 907       if (HasOwnership &&
 908           isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 909                                           ObjCPropertyDecl::OBJC_PR_copy)) {
 910         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_copy, "copy");
 911         continue;
 912       }
 913       if (HasOwnership && areIncompatiblePropertyAttributes(
 914                               OriginalAttributes, Attr,
 915                               ObjCPropertyDecl::OBJC_PR_retain |
 916                                   ObjCPropertyDecl::OBJC_PR_strong)) {
 917         Diag(OriginalAttributes & (ObjCPropertyDecl::OBJC_PR_retain |
 918                                    ObjCPropertyDecl::OBJC_PR_strong),
 919              "retain (or strong)");
 920         continue;
 921       }
 922       if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 923                                           ObjCPropertyDecl::OBJC_PR_atomic)) {
 924         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_atomic, "atomic");
 925         continue;
 926       }
 927     }
 928     if (Property->getGetterName() != Prop->getGetterName()) {
 929       Mismatches.push_back({Prop, DifferentGetter, ""});
 930       continue;
 931     }
 932     if (!Property->isReadOnly() && !Prop->isReadOnly() &&
 933         Property->getSetterName() != Prop->getSetterName()) {
 934       Mismatches.push_back({Prop, DifferentSetter, ""});
 935       continue;
 936     }
 937     QualType LHSType = S.Context.getCanonicalType(Prop->getType());
 938     if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
 939       bool IncompatibleObjC = false;
 940       QualType ConvertedType;
 941       if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
 942           || IncompatibleObjC) {
 943         Mismatches.push_back({Prop, IncompatibleType, ""});
 944         continue;
 945       }
 946     }
 947   }
 948
 949   if (Mismatches.empty())
 950     return Property;
 951
 952   // Diagnose incompability.
 953   {
 954     bool HasIncompatibleAttributes = false;
 955     for (const auto &Note : Mismatches)
 956       HasIncompatibleAttributes =
 957           Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
 958     // Promote the warning to an error if there are incompatible attributes or
 959     // incompatible types together with readwrite/readonly incompatibility.
 960     auto Diag = S.Diag(Property->getLocation(),
 961                        Property != OriginalProperty || HasIncompatibleAttributes
 962                            ? diag::err_protocol_property_mismatch
 963                            : diag::warn_protocol_property_mismatch);
 964     Diag << Mismatches[0].Kind;
 965     switch (Mismatches[0].Kind) {
 966     case IncompatibleType:
 967       Diag << Property->getType();
 968       break;
 969     case HasNoExpectedAttribute:
 970     case HasUnexpectedAttribute:
 971       Diag << Mismatches[0].AttributeName;
 972       break;
 973     case DifferentGetter:
 974       Diag << Property->getGetterName();
 975       break;
 976     case DifferentSetter:
 977       Diag << Property->getSetterName();
 978       break;
 979     }
 980   }
 981   for (const auto &Note : Mismatches) {
 982     auto Diag =
 983         S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
 984         << Note.Kind;
 985     switch (Note.Kind) {
 986     case IncompatibleType:
 987       Diag << Note.Prop->getType();
 988       break;
 989     case HasNoExpectedAttribute:
 990     case HasUnexpectedAttribute:
 991       Diag << Note.AttributeName;
 992       break;
 993     case DifferentGetter:
 994       Diag << Note.Prop->getGetterName();
 995       break;
 996     case DifferentSetter:
 997       Diag << Note.Prop->getSetterName();
 998       break;
 999     }
1000   }
1001   if (AtLoc.isValid())
1002     S.Diag(AtLoc, diag::note_property_synthesize);
1003
1004   return Property;
1005 }
1006
1007 /// Determine whether any storage attributes were written on the property.
1008 static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
1009                                        ObjCPropertyQueryKind QueryKind) {
1010   if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
1011
1012   // If this is a readwrite property in a class extension that refines
1013   // a readonly property in the original class definition, check it as
1014   // well.
1015
1016   // If it's a readonly property, we're not interested.
1017   if (Prop->isReadOnly()) return false;
1018
1019   // Is it declared in an extension?
1020   auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
1021   if (!Category || !Category->IsClassExtension()) return false;
1022
1023   // Find the corresponding property in the primary class definition.
1024   auto OrigClass = Category->getClassInterface();
1025   for (auto Found : OrigClass->lookup(Prop->getDeclName())) {
1026     if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
1027       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1028   }
1029
1030   // Look through all of the protocols.
1031   for (const auto *Proto : OrigClass->all_referenced_protocols()) {
1032     if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
1033             Prop->getIdentifier(), QueryKind))
1034       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1035   }
1036
1037   return false;
1038 }
1039
1040 /// ActOnPropertyImplDecl - This routine performs semantic checks and
1041 /// builds the AST node for a property implementation declaration; declared
1042 /// as \@synthesize or \@dynamic.
1043 ///
1044 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
1045                                   SourceLocation AtLoc,
1046                                   SourceLocation PropertyLoc,
1047                                   bool Synthesize,
1048                                   IdentifierInfo *PropertyId,
1049                                   IdentifierInfo *PropertyIvar,
1050                                   SourceLocation PropertyIvarLoc,
1051                                   ObjCPropertyQueryKind QueryKind) {
1052   ObjCContainerDecl *ClassImpDecl =
1053     dyn_cast<ObjCContainerDecl>(CurContext);
1054   // Make sure we have a context for the property implementation declaration.
1055   if (!ClassImpDecl) {
1056     Diag(AtLoc, diag::err_missing_property_context);
1057     return nullptr;
1058   }
1059   if (PropertyIvarLoc.isInvalid())
1060     PropertyIvarLoc = PropertyLoc;
1061   SourceLocation PropertyDiagLoc = PropertyLoc;
1062   if (PropertyDiagLoc.isInvalid())
1063     PropertyDiagLoc = ClassImpDecl->getBeginLoc();
1064   ObjCPropertyDecl *property = nullptr;
1065   ObjCInterfaceDecl *IDecl = nullptr;
1066   // Find the class or category class where this property must have
1067   // a declaration.
1068   ObjCImplementationDecl *IC = nullptr;
1069   ObjCCategoryImplDecl *CatImplClass = nullptr;
1070   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
1071     IDecl = IC->getClassInterface();
1072     // We always synthesize an interface for an implementation
1073     // without an interface decl. So, IDecl is always non-zero.
1074     assert(IDecl &&
1075            "ActOnPropertyImplDecl - @implementation without @interface");
1076
1077     // Look for this property declaration in the @implementation's @interface
1078     property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
1079     if (!property) {
1080       Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
1081       return nullptr;
1082     }
1083     if (property->isClassProperty() && Synthesize) {
1084       Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
1085       return nullptr;
1086     }
1087     unsigned PIkind = property->getPropertyAttributesAsWritten();
1088     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
1089                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
1090       if (AtLoc.isValid())
1091         Diag(AtLoc, diag::warn_implicit_atomic_property);
1092       else
1093         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
1094       Diag(property->getLocation(), diag::note_property_declare);
1095     }
1096
1097     if (const ObjCCategoryDecl *CD =
1098         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
1099       if (!CD->IsClassExtension()) {
1100         Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
1101         Diag(property->getLocation(), diag::note_property_declare);
1102         return nullptr;
1103       }
1104     }
1105     if (Synthesize&&
1106         (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
1107         property->hasAttr<IBOutletAttr>() &&
1108         !AtLoc.isValid()) {
1109       bool ReadWriteProperty = false;
1110       // Search into the class extensions and see if 'readonly property is
1111       // redeclared 'readwrite', then no warning is to be issued.
1112       for (auto *Ext : IDecl->known_extensions()) {
1113         DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
1114         if (!R.empty())
1115           if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
1116             PIkind = ExtProp->getPropertyAttributesAsWritten();
1117             if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
1118               ReadWriteProperty = true;
1119               break;
1120             }
1121           }
1122       }
1123
1124       if (!ReadWriteProperty) {
1125         Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
1126             << property;
1127         SourceLocation readonlyLoc;
1128         if (LocPropertyAttribute(Context, "readonly",
1129                                  property->getLParenLoc(), readonlyLoc)) {
1130           SourceLocation endLoc =
1131             readonlyLoc.getLocWithOffset(strlen("readonly")-1);
1132           SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
1133           Diag(property->getLocation(),
1134                diag::note_auto_readonly_iboutlet_fixup_suggest) <<
1135           FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
1136         }
1137       }
1138     }
1139     if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
1140       property = SelectPropertyForSynthesisFromProtocols(*this, AtLoc, IDecl,
1141                                                          property);
1142
1143   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
1144     if (Synthesize) {
1145       Diag(AtLoc, diag::err_synthesize_category_decl);
1146       return nullptr;
1147     }
1148     IDecl = CatImplClass->getClassInterface();
1149     if (!IDecl) {
1150       Diag(AtLoc, diag::err_missing_property_interface);
1151       return nullptr;
1152     }
1153     ObjCCategoryDecl *Category =
1154     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
1155
1156     // If category for this implementation not found, it is an error which
1157     // has already been reported eralier.
1158     if (!Category)
1159       return nullptr;
1160     // Look for this property declaration in @implementation's category
1161     property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
1162     if (!property) {
1163       Diag(PropertyLoc, diag::err_bad_category_property_decl)
1164       << Category->getDeclName();
1165       return nullptr;
1166     }
1167   } else {
1168     Diag(AtLoc, diag::err_bad_property_context);
1169     return nullptr;
1170   }
1171   ObjCIvarDecl *Ivar = nullptr;
1172   bool CompleteTypeErr = false;
1173   bool compat = true;
1174   // Check that we have a valid, previously declared ivar for @synthesize
1175   if (Synthesize) {
1176     // @synthesize
1177     if (!PropertyIvar)
1178       PropertyIvar = PropertyId;
1179     // Check that this is a previously declared 'ivar' in 'IDecl' interface
1180     ObjCInterfaceDecl *ClassDeclared;
1181     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
1182     QualType PropType = property->getType();
1183     QualType PropertyIvarType = PropType.getNonReferenceType();
1184
1185     if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
1186                             diag::err_incomplete_synthesized_property,
1187                             property->getDeclName())) {
1188       Diag(property->getLocation(), diag::note_property_declare);
1189       CompleteTypeErr = true;
1190     }
1191
1192     if (getLangOpts().ObjCAutoRefCount &&
1193         (property->getPropertyAttributesAsWritten() &
1194          ObjCPropertyDecl::OBJC_PR_readonly) &&
1195         PropertyIvarType->isObjCRetainableType()) {
1196       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
1197     }
1198
1199     ObjCPropertyDecl::PropertyAttributeKind kind
1200       = property->getPropertyAttributes();
1201
1202     bool isARCWeak = false;
1203     if (kind & ObjCPropertyDecl::OBJC_PR_weak) {
1204       // Add GC __weak to the ivar type if the property is weak.
1205       if (getLangOpts().getGC() != LangOptions::NonGC) {
1206         assert(!getLangOpts().ObjCAutoRefCount);
1207         if (PropertyIvarType.isObjCGCStrong()) {
1208           Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
1209           Diag(property->getLocation(), diag::note_property_declare);
1210         } else {
1211           PropertyIvarType =
1212             Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
1213         }
1214
1215       // Otherwise, check whether ARC __weak is enabled and works with
1216       // the property type.
1217       } else {
1218         if (!getLangOpts().ObjCWeak) {
1219           // Only complain here when synthesizing an ivar.
1220           if (!Ivar) {
1221             Diag(PropertyDiagLoc,
1222                  getLangOpts().ObjCWeakRuntime
1223                    ? diag::err_synthesizing_arc_weak_property_disabled
1224                    : diag::err_synthesizing_arc_weak_property_no_runtime);
1225             Diag(property->getLocation(), diag::note_property_declare);
1226           }
1227           CompleteTypeErr = true; // suppress later diagnostics about the ivar
1228         } else {
1229           isARCWeak = true;
1230           if (const ObjCObjectPointerType *ObjT =
1231                 PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1232             const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1233             if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1234               Diag(property->getLocation(),
1235                    diag::err_arc_weak_unavailable_property)
1236                 << PropertyIvarType;
1237               Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1238                 << ClassImpDecl->getName();
1239             }
1240           }
1241         }
1242       }
1243     }
1244
1245     if (AtLoc.isInvalid()) {
1246       // Check when default synthesizing a property that there is
1247       // an ivar matching property name and issue warning; since this
1248       // is the most common case of not using an ivar used for backing
1249       // property in non-default synthesis case.
1250       ObjCInterfaceDecl *ClassDeclared=nullptr;
1251       ObjCIvarDecl *originalIvar =
1252       IDecl->lookupInstanceVariable(property->getIdentifier(),
1253                                     ClassDeclared);
1254       if (originalIvar) {
1255         Diag(PropertyDiagLoc,
1256              diag::warn_autosynthesis_property_ivar_match)
1257         << PropertyId << (Ivar == nullptr) << PropertyIvar
1258         << originalIvar->getIdentifier();
1259         Diag(property->getLocation(), diag::note_property_declare);
1260         Diag(originalIvar->getLocation(), diag::note_ivar_decl);
1261       }
1262     }
1263
1264     if (!Ivar) {
1265       // In ARC, give the ivar a lifetime qualifier based on the
1266       // property attributes.
1267       if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
1268           !PropertyIvarType.getObjCLifetime() &&
1269           PropertyIvarType->isObjCRetainableType()) {
1270
1271         // It's an error if we have to do this and the user didn't
1272         // explicitly write an ownership attribute on the property.
1273         if (!hasWrittenStorageAttribute(property, QueryKind) &&
1274             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
1275           Diag(PropertyDiagLoc,
1276                diag::err_arc_objc_property_default_assign_on_object);
1277           Diag(property->getLocation(), diag::note_property_declare);
1278         } else {
1279           Qualifiers::ObjCLifetime lifetime =
1280             getImpliedARCOwnership(kind, PropertyIvarType);
1281           assert(lifetime && "no lifetime for property?");
1282
1283           Qualifiers qs;
1284           qs.addObjCLifetime(lifetime);
1285           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1286         }
1287       }
1288
1289       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1290                                   PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1291                                   PropertyIvarType, /*TInfo=*/nullptr,
1292                                   ObjCIvarDecl::Private,
1293                                   (Expr *)nullptr, true);
1294       if (RequireNonAbstractType(PropertyIvarLoc,
1295                                  PropertyIvarType,
1296                                  diag::err_abstract_type_in_decl,
1297                                  AbstractSynthesizedIvarType)) {
1298         Diag(property->getLocation(), diag::note_property_declare);
1299         // An abstract type is as bad as an incomplete type.
1300         CompleteTypeErr = true;
1301       }
1302       if (!CompleteTypeErr) {
1303         const RecordType *RecordTy = PropertyIvarType->getAs<RecordType>();
1304         if (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()) {
1305           Diag(PropertyIvarLoc, diag::err_synthesize_variable_sized_ivar)
1306             << PropertyIvarType;
1307           CompleteTypeErr = true; // suppress later diagnostics about the ivar
1308         }
1309       }
1310       if (CompleteTypeErr)
1311         Ivar->setInvalidDecl();
1312       ClassImpDecl->addDecl(Ivar);
1313       IDecl->makeDeclVisibleInContext(Ivar);
1314
1315       if (getLangOpts().ObjCRuntime.isFragile())
1316         Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
1317             << PropertyId;
1318       // Note! I deliberately want it to fall thru so, we have a
1319       // a property implementation and to avoid future warnings.
1320     } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1321                !declaresSameEntity(ClassDeclared, IDecl)) {
1322       Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
1323       << property->getDeclName() << Ivar->getDeclName()
1324       << ClassDeclared->getDeclName();
1325       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1326       << Ivar << Ivar->getName();
1327       // Note! I deliberately want it to fall thru so more errors are caught.
1328     }
1329     property->setPropertyIvarDecl(Ivar);
1330
1331     QualType IvarType = Context.getCanonicalType(Ivar->getType());
1332
1333     // Check that type of property and its ivar are type compatible.
1334     if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1335       if (isa<ObjCObjectPointerType>(PropertyIvarType)
1336           && isa<ObjCObjectPointerType>(IvarType))
1337         compat =
1338           Context.canAssignObjCInterfaces(
1339                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
1340                                   IvarType->getAs<ObjCObjectPointerType>());
1341       else {
1342         compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1343                                              IvarType)
1344                     == Compatible);
1345       }
1346       if (!compat) {
1347         Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1348           << property->getDeclName() << PropType
1349           << Ivar->getDeclName() << IvarType;
1350         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1351         // Note! I deliberately want it to fall thru so, we have a
1352         // a property implementation and to avoid future warnings.
1353       }
1354       else {
1355         // FIXME! Rules for properties are somewhat different that those
1356         // for assignments. Use a new routine to consolidate all cases;
1357         // specifically for property redeclarations as well as for ivars.
1358         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1359         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1360         if (lhsType != rhsType &&
1361             lhsType->isArithmeticType()) {
1362           Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1363             << property->getDeclName() << PropType
1364             << Ivar->getDeclName() << IvarType;
1365           Diag(Ivar->getLocation(), diag::note_ivar_decl);
1366           // Fall thru - see previous comment
1367         }
1368       }
1369       // __weak is explicit. So it works on Canonical type.
1370       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1371            getLangOpts().getGC() != LangOptions::NonGC)) {
1372         Diag(PropertyDiagLoc, diag::err_weak_property)
1373         << property->getDeclName() << Ivar->getDeclName();
1374         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1375         // Fall thru - see previous comment
1376       }
1377       // Fall thru - see previous comment
1378       if ((property->getType()->isObjCObjectPointerType() ||
1379            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1380           getLangOpts().getGC() != LangOptions::NonGC) {
1381         Diag(PropertyDiagLoc, diag::err_strong_property)
1382         << property->getDeclName() << Ivar->getDeclName();
1383         // Fall thru - see previous comment
1384       }
1385     }
1386     if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1387         Ivar->getType().getObjCLifetime())
1388       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1389   } else if (PropertyIvar)
1390     // @dynamic
1391     Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
1392
1393   assert (property && "ActOnPropertyImplDecl - property declaration missing");
1394   ObjCPropertyImplDecl *PIDecl =
1395   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1396                                property,
1397                                (Synthesize ?
1398                                 ObjCPropertyImplDecl::Synthesize
1399                                 : ObjCPropertyImplDecl::Dynamic),
1400                                Ivar, PropertyIvarLoc);
1401
1402   if (CompleteTypeErr || !compat)
1403     PIDecl->setInvalidDecl();
1404
1405   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1406     getterMethod->createImplicitParams(Context, IDecl);
1407     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1408         Ivar->getType()->isRecordType()) {
1409       // For Objective-C++, need to synthesize the AST for the IVAR object to be
1410       // returned by the getter as it must conform to C++'s copy-return rules.
1411       // FIXME. Eventually we want to do this for Objective-C as well.
1412       SynthesizedFunctionScope Scope(*this, getterMethod);
1413       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1414       DeclRefExpr *SelfExpr = new (Context)
1415           DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1416                       PropertyDiagLoc);
1417       MarkDeclRefReferenced(SelfExpr);
1418       Expr *LoadSelfExpr =
1419         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1420                                  CK_LValueToRValue, SelfExpr, nullptr,
1421                                  VK_RValue);
1422       Expr *IvarRefExpr =
1423         new (Context) ObjCIvarRefExpr(Ivar,
1424                                       Ivar->getUsageType(SelfDecl->getType()),
1425                                       PropertyDiagLoc,
1426                                       Ivar->getLocation(),
1427                                       LoadSelfExpr, true, true);
1428       ExprResult Res = PerformCopyInitialization(
1429           InitializedEntity::InitializeResult(PropertyDiagLoc,
1430                                               getterMethod->getReturnType(),
1431                                               /*NRVO=*/false),
1432           PropertyDiagLoc, IvarRefExpr);
1433       if (!Res.isInvalid()) {
1434         Expr *ResExpr = Res.getAs<Expr>();
1435         if (ResExpr)
1436           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1437         PIDecl->setGetterCXXConstructor(ResExpr);
1438       }
1439     }
1440     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1441         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1442       Diag(getterMethod->getLocation(),
1443            diag::warn_property_getter_owning_mismatch);
1444       Diag(property->getLocation(), diag::note_property_declare);
1445     }
1446     if (getLangOpts().ObjCAutoRefCount && Synthesize)
1447       switch (getterMethod->getMethodFamily()) {
1448         case OMF_retain:
1449         case OMF_retainCount:
1450         case OMF_release:
1451         case OMF_autorelease:
1452           Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1453             << 1 << getterMethod->getSelector();
1454           break;
1455         default:
1456           break;
1457       }
1458   }
1459   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1460     setterMethod->createImplicitParams(Context, IDecl);
1461     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1462         Ivar->getType()->isRecordType()) {
1463       // FIXME. Eventually we want to do this for Objective-C as well.
1464       SynthesizedFunctionScope Scope(*this, setterMethod);
1465       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1466       DeclRefExpr *SelfExpr = new (Context)
1467           DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1468                       PropertyDiagLoc);
1469       MarkDeclRefReferenced(SelfExpr);
1470       Expr *LoadSelfExpr =
1471         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1472                                  CK_LValueToRValue, SelfExpr, nullptr,
1473                                  VK_RValue);
1474       Expr *lhs =
1475         new (Context) ObjCIvarRefExpr(Ivar,
1476                                       Ivar->getUsageType(SelfDecl->getType()),
1477                                       PropertyDiagLoc,
1478                                       Ivar->getLocation(),
1479                                       LoadSelfExpr, true, true);
1480       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1481       ParmVarDecl *Param = (*P);
1482       QualType T = Param->getType().getNonReferenceType();
1483       DeclRefExpr *rhs = new (Context)
1484           DeclRefExpr(Context, Param, false, T, VK_LValue, PropertyDiagLoc);
1485       MarkDeclRefReferenced(rhs);
1486       ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1487                                   BO_Assign, lhs, rhs);
1488       if (property->getPropertyAttributes() &
1489           ObjCPropertyDecl::OBJC_PR_atomic) {
1490         Expr *callExpr = Res.getAs<Expr>();
1491         if (const CXXOperatorCallExpr *CXXCE =
1492               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1493           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1494             if (!FuncDecl->isTrivial())
1495               if (property->getType()->isReferenceType()) {
1496                 Diag(PropertyDiagLoc,
1497                      diag::err_atomic_property_nontrivial_assign_op)
1498                     << property->getType();
1499                 Diag(FuncDecl->getBeginLoc(), diag::note_callee_decl)
1500                     << FuncDecl;
1501               }
1502       }
1503       PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1504     }
1505   }
1506
1507   if (IC) {
1508     if (Synthesize)
1509       if (ObjCPropertyImplDecl *PPIDecl =
1510           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1511         Diag(PropertyLoc, diag::err_duplicate_ivar_use)
1512         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1513         << PropertyIvar;
1514         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1515       }
1516
1517     if (ObjCPropertyImplDecl *PPIDecl
1518         = IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
1519       Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
1520       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1521       return nullptr;
1522     }
1523     IC->addPropertyImplementation(PIDecl);
1524     if (getLangOpts().ObjCDefaultSynthProperties &&
1525         getLangOpts().ObjCRuntime.isNonFragile() &&
1526         !IDecl->isObjCRequiresPropertyDefs()) {
1527       // Diagnose if an ivar was lazily synthesdized due to a previous
1528       // use and if 1) property is @dynamic or 2) property is synthesized
1529       // but it requires an ivar of different name.
1530       ObjCInterfaceDecl *ClassDeclared=nullptr;
1531       ObjCIvarDecl *Ivar = nullptr;
1532       if (!Synthesize)
1533         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1534       else {
1535         if (PropertyIvar && PropertyIvar != PropertyId)
1536           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1537       }
1538       // Issue diagnostics only if Ivar belongs to current class.
1539       if (Ivar && Ivar->getSynthesize() &&
1540           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1541         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1542         << PropertyId;
1543         Ivar->setInvalidDecl();
1544       }
1545     }
1546   } else {
1547     if (Synthesize)
1548       if (ObjCPropertyImplDecl *PPIDecl =
1549           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1550         Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
1551         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1552         << PropertyIvar;
1553         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1554       }
1555
1556     if (ObjCPropertyImplDecl *PPIDecl =
1557         CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
1558       Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
1559       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1560       return nullptr;
1561     }
1562     CatImplClass->addPropertyImplementation(PIDecl);
1563   }
1564
1565   return PIDecl;
1566 }
1567
1568 //===----------------------------------------------------------------------===//
1569 // Helper methods.
1570 //===----------------------------------------------------------------------===//
1571
1572 /// DiagnosePropertyMismatch - Compares two properties for their
1573 /// attributes and types and warns on a variety of inconsistencies.
1574 ///
1575 void
1576 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1577                                ObjCPropertyDecl *SuperProperty,
1578                                const IdentifierInfo *inheritedName,
1579                                bool OverridingProtocolProperty) {
1580   ObjCPropertyDecl::PropertyAttributeKind CAttr =
1581     Property->getPropertyAttributes();
1582   ObjCPropertyDecl::PropertyAttributeKind SAttr =
1583     SuperProperty->getPropertyAttributes();
1584
1585   // We allow readonly properties without an explicit ownership
1586   // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1587   // to be overridden by a property with any explicit ownership in the subclass.
1588   if (!OverridingProtocolProperty &&
1589       !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1590     ;
1591   else {
1592     if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
1593         && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
1594       Diag(Property->getLocation(), diag::warn_readonly_property)
1595         << Property->getDeclName() << inheritedName;
1596     if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
1597         != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
1598       Diag(Property->getLocation(), diag::warn_property_attribute)
1599         << Property->getDeclName() << "copy" << inheritedName;
1600     else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
1601       unsigned CAttrRetain =
1602         (CAttr &
1603          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1604       unsigned SAttrRetain =
1605         (SAttr &
1606          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1607       bool CStrong = (CAttrRetain != 0);
1608       bool SStrong = (SAttrRetain != 0);
1609       if (CStrong != SStrong)
1610         Diag(Property->getLocation(), diag::warn_property_attribute)
1611           << Property->getDeclName() << "retain (or strong)" << inheritedName;
1612     }
1613   }
1614
1615   // Check for nonatomic; note that nonatomic is effectively
1616   // meaningless for readonly properties, so don't diagnose if the
1617   // atomic property is 'readonly'.
1618   checkAtomicPropertyMismatch(*this, SuperProperty, Property, false);
1619   // Readonly properties from protocols can be implemented as "readwrite"
1620   // with a custom setter name.
1621   if (Property->getSetterName() != SuperProperty->getSetterName() &&
1622       !(SuperProperty->isReadOnly() &&
1623         isa<ObjCProtocolDecl>(SuperProperty->getDeclContext()))) {
1624     Diag(Property->getLocation(), diag::warn_property_attribute)
1625       << Property->getDeclName() << "setter" << inheritedName;
1626     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1627   }
1628   if (Property->getGetterName() != SuperProperty->getGetterName()) {
1629     Diag(Property->getLocation(), diag::warn_property_attribute)
1630       << Property->getDeclName() << "getter" << inheritedName;
1631     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1632   }
1633
1634   QualType LHSType =
1635     Context.getCanonicalType(SuperProperty->getType());
1636   QualType RHSType =
1637     Context.getCanonicalType(Property->getType());
1638
1639   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1640     // Do cases not handled in above.
1641     // FIXME. For future support of covariant property types, revisit this.
1642     bool IncompatibleObjC = false;
1643     QualType ConvertedType;
1644     if (!isObjCPointerConversion(RHSType, LHSType,
1645                                  ConvertedType, IncompatibleObjC) ||
1646         IncompatibleObjC) {
1647         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1648         << Property->getType() << SuperProperty->getType() << inheritedName;
1649       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1650     }
1651   }
1652 }
1653
1654 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1655                                             ObjCMethodDecl *GetterMethod,
1656                                             SourceLocation Loc) {
1657   if (!GetterMethod)
1658     return false;
1659   QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1660   QualType PropertyRValueType =
1661       property->getType().getNonReferenceType().getAtomicUnqualifiedType();
1662   bool compat = Context.hasSameType(PropertyRValueType, GetterType);
1663   if (!compat) {
1664     const ObjCObjectPointerType *propertyObjCPtr = nullptr;
1665     const ObjCObjectPointerType *getterObjCPtr = nullptr;
1666     if ((propertyObjCPtr =
1667              PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
1668         (getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
1669       compat = Context.canAssignObjCInterfaces(getterObjCPtr, propertyObjCPtr);
1670     else if (CheckAssignmentConstraints(Loc, GetterType, PropertyRValueType)
1671               != Compatible) {
1672           Diag(Loc, diag::err_property_accessor_type)
1673             << property->getDeclName() << PropertyRValueType
1674             << GetterMethod->getSelector() << GetterType;
1675           Diag(GetterMethod->getLocation(), diag::note_declared_at);
1676           return true;
1677     } else {
1678       compat = true;
1679       QualType lhsType = Context.getCanonicalType(PropertyRValueType);
1680       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1681       if (lhsType != rhsType && lhsType->isArithmeticType())
1682         compat = false;
1683     }
1684   }
1685
1686   if (!compat) {
1687     Diag(Loc, diag::warn_accessor_property_type_mismatch)
1688     << property->getDeclName()
1689     << GetterMethod->getSelector();
1690     Diag(GetterMethod->getLocation(), diag::note_declared_at);
1691     return true;
1692   }
1693
1694   return false;
1695 }
1696
1697 /// CollectImmediateProperties - This routine collects all properties in
1698 /// the class and its conforming protocols; but not those in its super class.
1699 static void
1700 CollectImmediateProperties(ObjCContainerDecl *CDecl,
1701                            ObjCContainerDecl::PropertyMap &PropMap,
1702                            ObjCContainerDecl::PropertyMap &SuperPropMap,
1703                            bool CollectClassPropsOnly = false,
1704                            bool IncludeProtocols = true) {
1705   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1706     for (auto *Prop : IDecl->properties()) {
1707       if (CollectClassPropsOnly && !Prop->isClassProperty())
1708         continue;
1709       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1710           Prop;
1711     }
1712
1713     // Collect the properties from visible extensions.
1714     for (auto *Ext : IDecl->visible_extensions())
1715       CollectImmediateProperties(Ext, PropMap, SuperPropMap,
1716                                  CollectClassPropsOnly, IncludeProtocols);
1717
1718     if (IncludeProtocols) {
1719       // Scan through class's protocols.
1720       for (auto *PI : IDecl->all_referenced_protocols())
1721         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1722                                    CollectClassPropsOnly);
1723     }
1724   }
1725   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1726     for (auto *Prop : CATDecl->properties()) {
1727       if (CollectClassPropsOnly && !Prop->isClassProperty())
1728         continue;
1729       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1730           Prop;
1731     }
1732     if (IncludeProtocols) {
1733       // Scan through class's protocols.
1734       for (auto *PI : CATDecl->protocols())
1735         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1736                                    CollectClassPropsOnly);
1737     }
1738   }
1739   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1740     for (auto *Prop : PDecl->properties()) {
1741       if (CollectClassPropsOnly && !Prop->isClassProperty())
1742         continue;
1743       ObjCPropertyDecl *PropertyFromSuper =
1744           SuperPropMap[std::make_pair(Prop->getIdentifier(),
1745                                       Prop->isClassProperty())];
1746       // Exclude property for protocols which conform to class's super-class,
1747       // as super-class has to implement the property.
1748       if (!PropertyFromSuper ||
1749           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1750         ObjCPropertyDecl *&PropEntry =
1751             PropMap[std::make_pair(Prop->getIdentifier(),
1752                                    Prop->isClassProperty())];
1753         if (!PropEntry)
1754           PropEntry = Prop;
1755       }
1756     }
1757     // Scan through protocol's protocols.
1758     for (auto *PI : PDecl->protocols())
1759       CollectImmediateProperties(PI, PropMap, SuperPropMap,
1760                                  CollectClassPropsOnly);
1761   }
1762 }
1763
1764 /// CollectSuperClassPropertyImplementations - This routine collects list of
1765 /// properties to be implemented in super class(s) and also coming from their
1766 /// conforming protocols.
1767 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1768                                     ObjCInterfaceDecl::PropertyMap &PropMap) {
1769   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1770     ObjCInterfaceDecl::PropertyDeclOrder PO;
1771     while (SDecl) {
1772       SDecl->collectPropertiesToImplement(PropMap, PO);
1773       SDecl = SDecl->getSuperClass();
1774     }
1775   }
1776 }
1777
1778 /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1779 /// an ivar synthesized for 'Method' and 'Method' is a property accessor
1780 /// declared in class 'IFace'.
1781 bool
1782 Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1783                                      ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1784   if (!IV->getSynthesize())
1785     return false;
1786   ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1787                                             Method->isInstanceMethod());
1788   if (!IMD || !IMD->isPropertyAccessor())
1789     return false;
1790
1791   // look up a property declaration whose one of its accessors is implemented
1792   // by this method.
1793   for (const auto *Property : IFace->instance_properties()) {
1794     if ((Property->getGetterName() == IMD->getSelector() ||
1795          Property->getSetterName() == IMD->getSelector()) &&
1796         (Property->getPropertyIvarDecl() == IV))
1797       return true;
1798   }
1799   // Also look up property declaration in class extension whose one of its
1800   // accessors is implemented by this method.
1801   for (const auto *Ext : IFace->known_extensions())
1802     for (const auto *Property : Ext->instance_properties())
1803       if ((Property->getGetterName() == IMD->getSelector() ||
1804            Property->getSetterName() == IMD->getSelector()) &&
1805           (Property->getPropertyIvarDecl() == IV))
1806         return true;
1807   return false;
1808 }
1809
1810 static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1811                                          ObjCPropertyDecl *Prop) {
1812   bool SuperClassImplementsGetter = false;
1813   bool SuperClassImplementsSetter = false;
1814   if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1815     SuperClassImplementsSetter = true;
1816
1817   while (IDecl->getSuperClass()) {
1818     ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1819     if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1820       SuperClassImplementsGetter = true;
1821
1822     if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1823       SuperClassImplementsSetter = true;
1824     if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1825       return true;
1826     IDecl = IDecl->getSuperClass();
1827   }
1828   return false;
1829 }
1830
1831 /// Default synthesizes all properties which must be synthesized
1832 /// in class's \@implementation.
1833 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
1834                                        ObjCInterfaceDecl *IDecl,
1835                                        SourceLocation AtEnd) {
1836   ObjCInterfaceDecl::PropertyMap PropMap;
1837   ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
1838   IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
1839   if (PropMap.empty())
1840     return;
1841   ObjCInterfaceDecl::PropertyMap SuperPropMap;
1842   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1843
1844   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
1845     ObjCPropertyDecl *Prop = PropertyOrder[i];
1846     // Is there a matching property synthesize/dynamic?
1847     if (Prop->isInvalidDecl() ||
1848         Prop->isClassProperty() ||
1849         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1850       continue;
1851     // Property may have been synthesized by user.
1852     if (IMPDecl->FindPropertyImplDecl(
1853             Prop->getIdentifier(), Prop->getQueryKind()))
1854       continue;
1855     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1856       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1857         continue;
1858       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1859         continue;
1860     }
1861     if (ObjCPropertyImplDecl *PID =
1862         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1863       Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1864         << Prop->getIdentifier();
1865       if (PID->getLocation().isValid())
1866         Diag(PID->getLocation(), diag::note_property_synthesize);
1867       continue;
1868     }
1869     ObjCPropertyDecl *PropInSuperClass =
1870         SuperPropMap[std::make_pair(Prop->getIdentifier(),
1871                                     Prop->isClassProperty())];
1872     if (ObjCProtocolDecl *Proto =
1873           dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1874       // We won't auto-synthesize properties declared in protocols.
1875       // Suppress the warning if class's superclass implements property's
1876       // getter and implements property's setter (if readwrite property).
1877       // Or, if property is going to be implemented in its super class.
1878       if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1879         Diag(IMPDecl->getLocation(),
1880              diag::warn_auto_synthesizing_protocol_property)
1881           << Prop << Proto;
1882         Diag(Prop->getLocation(), diag::note_property_declare);
1883         std::string FixIt =
1884             (Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
1885         Diag(AtEnd, diag::note_add_synthesize_directive)
1886             << FixItHint::CreateInsertion(AtEnd, FixIt);
1887       }
1888       continue;
1889     }
1890     // If property to be implemented in the super class, ignore.
1891     if (PropInSuperClass) {
1892       if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
1893           (PropInSuperClass->getPropertyAttributes() &
1894            ObjCPropertyDecl::OBJC_PR_readonly) &&
1895           !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1896           !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1897         Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1898         << Prop->getIdentifier();
1899         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1900       }
1901       else {
1902         Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1903         << Prop->getIdentifier();
1904         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1905         Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1906       }
1907       continue;
1908     }
1909     // We use invalid SourceLocations for the synthesized ivars since they
1910     // aren't really synthesized at a particular location; they just exist.
1911     // Saying that they are located at the @implementation isn't really going
1912     // to help users.
1913     ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1914       ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1915                             true,
1916                             /* property = */ Prop->getIdentifier(),
1917                             /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1918                             Prop->getLocation(), Prop->getQueryKind()));
1919     if (PIDecl && !Prop->isUnavailable()) {
1920       Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1921       Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1922     }
1923   }
1924 }
1925
1926 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
1927                                        SourceLocation AtEnd) {
1928   if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1929     return;
1930   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1931   if (!IC)
1932     return;
1933   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1934     if (!IDecl->isObjCRequiresPropertyDefs())
1935       DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
1936 }
1937
1938 static void DiagnoseUnimplementedAccessor(
1939     Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
1940     ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
1941     ObjCPropertyDecl *Prop,
1942     llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
1943   // Check to see if we have a corresponding selector in SMap and with the
1944   // right method type.
1945   auto I = llvm::find_if(SMap, [&](const ObjCMethodDecl *x) {
1946     return x->getSelector() == Method &&
1947            x->isClassMethod() == Prop->isClassProperty();
1948   });
1949   // When reporting on missing property setter/getter implementation in
1950   // categories, do not report when they are declared in primary class,
1951   // class's protocol, or one of it super classes. This is because,
1952   // the class is going to implement them.
1953   if (I == SMap.end() &&
1954       (PrimaryClass == nullptr ||
1955        !PrimaryClass->lookupPropertyAccessor(Method, C,
1956                                              Prop->isClassProperty()))) {
1957     unsigned diag =
1958         isa<ObjCCategoryDecl>(CDecl)
1959             ? (Prop->isClassProperty()
1960                    ? diag::warn_impl_required_in_category_for_class_property
1961                    : diag::warn_setter_getter_impl_required_in_category)
1962             : (Prop->isClassProperty()
1963                    ? diag::warn_impl_required_for_class_property
1964                    : diag::warn_setter_getter_impl_required);
1965     S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
1966     S.Diag(Prop->getLocation(), diag::note_property_declare);
1967     if (S.LangOpts.ObjCDefaultSynthProperties &&
1968         S.LangOpts.ObjCRuntime.isNonFragile())
1969       if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1970         if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1971           S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1972   }
1973 }
1974
1975 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1976                                            ObjCContainerDecl *CDecl,
1977                                            bool SynthesizeProperties) {
1978   ObjCContainerDecl::PropertyMap PropMap;
1979   ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
1980
1981   // Since we don't synthesize class properties, we should emit diagnose even
1982   // if SynthesizeProperties is true.
1983   ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1984   // Gather properties which need not be implemented in this class
1985   // or category.
1986   if (!IDecl)
1987     if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1988       // For categories, no need to implement properties declared in
1989       // its primary class (and its super classes) if property is
1990       // declared in one of those containers.
1991       if ((IDecl = C->getClassInterface())) {
1992         ObjCInterfaceDecl::PropertyDeclOrder PO;
1993         IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
1994       }
1995     }
1996   if (IDecl)
1997     CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
1998
1999   // When SynthesizeProperties is true, we only check class properties.
2000   CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap,
2001                              SynthesizeProperties/*CollectClassPropsOnly*/);
2002
2003   // Scan the @interface to see if any of the protocols it adopts
2004   // require an explicit implementation, via attribute
2005   // 'objc_protocol_requires_explicit_implementation'.
2006   if (IDecl) {
2007     std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
2008
2009     for (auto *PDecl : IDecl->all_referenced_protocols()) {
2010       if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2011         continue;
2012       // Lazily construct a set of all the properties in the @interface
2013       // of the class, without looking at the superclass.  We cannot
2014       // use the call to CollectImmediateProperties() above as that
2015       // utilizes information from the super class's properties as well
2016       // as scans the adopted protocols.  This work only triggers for protocols
2017       // with the attribute, which is very rare, and only occurs when
2018       // analyzing the @implementation.
2019       if (!LazyMap) {
2020         ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2021         LazyMap.reset(new ObjCContainerDecl::PropertyMap());
2022         CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
2023                                    /* CollectClassPropsOnly */ false,
2024                                    /* IncludeProtocols */ false);
2025       }
2026       // Add the properties of 'PDecl' to the list of properties that
2027       // need to be implemented.
2028       for (auto *PropDecl : PDecl->properties()) {
2029         if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
2030                                       PropDecl->isClassProperty())])
2031           continue;
2032         PropMap[std::make_pair(PropDecl->getIdentifier(),
2033                                PropDecl->isClassProperty())] = PropDecl;
2034       }
2035     }
2036   }
2037
2038   if (PropMap.empty())
2039     return;
2040
2041   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
2042   for (const auto *I : IMPDecl->property_impls())
2043     PropImplMap.insert(I->getPropertyDecl());
2044
2045   llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
2046   // Collect property accessors implemented in current implementation.
2047   for (const auto *I : IMPDecl->methods())
2048     InsMap.insert(I);
2049
2050   ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2051   ObjCInterfaceDecl *PrimaryClass = nullptr;
2052   if (C && !C->IsClassExtension())
2053     if ((PrimaryClass = C->getClassInterface()))
2054       // Report unimplemented properties in the category as well.
2055       if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
2056         // When reporting on missing setter/getters, do not report when
2057         // setter/getter is implemented in category's primary class
2058         // implementation.
2059         for (const auto *I : IMP->methods())
2060           InsMap.insert(I);
2061       }
2062
2063   for (ObjCContainerDecl::PropertyMap::iterator
2064        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
2065     ObjCPropertyDecl *Prop = P->second;
2066     // Is there a matching property synthesize/dynamic?
2067     if (Prop->isInvalidDecl() ||
2068         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
2069         PropImplMap.count(Prop) ||
2070         Prop->getAvailability() == AR_Unavailable)
2071       continue;
2072
2073     // Diagnose unimplemented getters and setters.
2074     DiagnoseUnimplementedAccessor(*this,
2075           PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
2076     if (!Prop->isReadOnly())
2077       DiagnoseUnimplementedAccessor(*this,
2078                                     PrimaryClass, Prop->getSetterName(),
2079                                     IMPDecl, CDecl, C, Prop, InsMap);
2080   }
2081 }
2082
2083 void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
2084   for (const auto *propertyImpl : impDecl->property_impls()) {
2085     const auto *property = propertyImpl->getPropertyDecl();
2086
2087     // Warn about null_resettable properties with synthesized setters,
2088     // because the setter won't properly handle nil.
2089     if (propertyImpl->getPropertyImplementation()
2090           == ObjCPropertyImplDecl::Synthesize &&
2091         (property->getPropertyAttributes() &
2092          ObjCPropertyDecl::OBJC_PR_null_resettable) &&
2093         property->getGetterMethodDecl() &&
2094         property->getSetterMethodDecl()) {
2095       auto *getterMethod = property->getGetterMethodDecl();
2096       auto *setterMethod = property->getSetterMethodDecl();
2097       if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
2098           !impDecl->getInstanceMethod(getterMethod->getSelector())) {
2099         SourceLocation loc = propertyImpl->getLocation();
2100         if (loc.isInvalid())
2101           loc = impDecl->getBeginLoc();
2102
2103         Diag(loc, diag::warn_null_resettable_setter)
2104           << setterMethod->getSelector() << property->getDeclName();
2105       }
2106     }
2107   }
2108 }
2109
2110 void
2111 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
2112                                        ObjCInterfaceDecl* IDecl) {
2113   // Rules apply in non-GC mode only
2114   if (getLangOpts().getGC() != LangOptions::NonGC)
2115     return;
2116   ObjCContainerDecl::PropertyMap PM;
2117   for (auto *Prop : IDecl->properties())
2118     PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2119   for (const auto *Ext : IDecl->known_extensions())
2120     for (auto *Prop : Ext->properties())
2121       PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2122
2123   for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
2124        I != E; ++I) {
2125     const ObjCPropertyDecl *Property = I->second;
2126     ObjCMethodDecl *GetterMethod = nullptr;
2127     ObjCMethodDecl *SetterMethod = nullptr;
2128     bool LookedUpGetterSetter = false;
2129
2130     unsigned Attributes = Property->getPropertyAttributes();
2131     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
2132
2133     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
2134         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
2135       GetterMethod = Property->isClassProperty() ?
2136                      IMPDecl->getClassMethod(Property->getGetterName()) :
2137                      IMPDecl->getInstanceMethod(Property->getGetterName());
2138       SetterMethod = Property->isClassProperty() ?
2139                      IMPDecl->getClassMethod(Property->getSetterName()) :
2140                      IMPDecl->getInstanceMethod(Property->getSetterName());
2141       LookedUpGetterSetter = true;
2142       if (GetterMethod) {
2143         Diag(GetterMethod->getLocation(),
2144              diag::warn_default_atomic_custom_getter_setter)
2145           << Property->getIdentifier() << 0;
2146         Diag(Property->getLocation(), diag::note_property_declare);
2147       }
2148       if (SetterMethod) {
2149         Diag(SetterMethod->getLocation(),
2150              diag::warn_default_atomic_custom_getter_setter)
2151           << Property->getIdentifier() << 1;
2152         Diag(Property->getLocation(), diag::note_property_declare);
2153       }
2154     }
2155
2156     // We only care about readwrite atomic property.
2157     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
2158         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
2159       continue;
2160     if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
2161             Property->getIdentifier(), Property->getQueryKind())) {
2162       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
2163         continue;
2164       if (!LookedUpGetterSetter) {
2165         GetterMethod = Property->isClassProperty() ?
2166                        IMPDecl->getClassMethod(Property->getGetterName()) :
2167                        IMPDecl->getInstanceMethod(Property->getGetterName());
2168         SetterMethod = Property->isClassProperty() ?
2169                        IMPDecl->getClassMethod(Property->getSetterName()) :
2170                        IMPDecl->getInstanceMethod(Property->getSetterName());
2171       }
2172       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
2173         SourceLocation MethodLoc =
2174           (GetterMethod ? GetterMethod->getLocation()
2175                         : SetterMethod->getLocation());
2176         Diag(MethodLoc, diag::warn_atomic_property_rule)
2177           << Property->getIdentifier() << (GetterMethod != nullptr)
2178           << (SetterMethod != nullptr);
2179         // fixit stuff.
2180         if (Property->getLParenLoc().isValid() &&
2181             !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
2182           // @property () ... case.
2183           SourceLocation AfterLParen =
2184             getLocForEndOfToken(Property->getLParenLoc());
2185           StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
2186                                                       : "nonatomic";
2187           Diag(Property->getLocation(),
2188                diag::note_atomic_property_fixup_suggest)
2189             << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
2190         } else if (Property->getLParenLoc().isInvalid()) {
2191           //@property id etc.
2192           SourceLocation startLoc =
2193             Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
2194           Diag(Property->getLocation(),
2195                diag::note_atomic_property_fixup_suggest)
2196             << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
2197         }
2198         else
2199           Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
2200         Diag(Property->getLocation(), diag::note_property_declare);
2201       }
2202     }
2203   }
2204 }
2205
2206 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
2207   if (getLangOpts().getGC() == LangOptions::GCOnly)
2208     return;
2209
2210   for (const auto *PID : D->property_impls()) {
2211     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
2212     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
2213         !PD->isClassProperty() &&
2214         !D->getInstanceMethod(PD->getGetterName())) {
2215       ObjCMethodDecl *method = PD->getGetterMethodDecl();
2216       if (!method)
2217         continue;
2218       ObjCMethodFamily family = method->getMethodFamily();
2219       if (family == OMF_alloc || family == OMF_copy ||
2220           family == OMF_mutableCopy || family == OMF_new) {
2221         if (getLangOpts().ObjCAutoRefCount)
2222           Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
2223         else
2224           Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
2225
2226         // Look for a getter explicitly declared alongside the property.
2227         // If we find one, use its location for the note.
2228         SourceLocation noteLoc = PD->getLocation();
2229         SourceLocation fixItLoc;
2230         for (auto *getterRedecl : method->redecls()) {
2231           if (getterRedecl->isImplicit())
2232             continue;
2233           if (getterRedecl->getDeclContext() != PD->getDeclContext())
2234             continue;
2235           noteLoc = getterRedecl->getLocation();
2236           fixItLoc = getterRedecl->getEndLoc();
2237         }
2238
2239         Preprocessor &PP = getPreprocessor();
2240         TokenValue tokens[] = {
2241           tok::kw___attribute, tok::l_paren, tok::l_paren,
2242           PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
2243           PP.getIdentifierInfo("none"), tok::r_paren,
2244           tok::r_paren, tok::r_paren
2245         };
2246         StringRef spelling = "__attribute__((objc_method_family(none)))";
2247         StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
2248         if (!macroName.empty())
2249           spelling = macroName;
2250
2251         auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
2252             << method->getDeclName() << spelling;
2253         if (fixItLoc.isValid()) {
2254           SmallString<64> fixItText(" ");
2255           fixItText += spelling;
2256           noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
2257         }
2258       }
2259     }
2260   }
2261 }
2262
2263 void Sema::DiagnoseMissingDesignatedInitOverrides(
2264                                             const ObjCImplementationDecl *ImplD,
2265                                             const ObjCInterfaceDecl *IFD) {
2266   assert(IFD->hasDesignatedInitializers());
2267   const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
2268   if (!SuperD)
2269     return;
2270
2271   SelectorSet InitSelSet;
2272   for (const auto *I : ImplD->instance_methods())
2273     if (I->getMethodFamily() == OMF_init)
2274       InitSelSet.insert(I->getSelector());
2275
2276   SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
2277   SuperD->getDesignatedInitializers(DesignatedInits);
2278   for (SmallVector<const ObjCMethodDecl *, 8>::iterator
2279          I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
2280     const ObjCMethodDecl *MD = *I;
2281     if (!InitSelSet.count(MD->getSelector())) {
2282       // Don't emit a diagnostic if the overriding method in the subclass is
2283       // marked as unavailable.
2284       bool Ignore = false;
2285       if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
2286         Ignore = IMD->isUnavailable();
2287       } else {
2288         // Check the methods declared in the class extensions too.
2289         for (auto *Ext : IFD->visible_extensions())
2290           if (auto *IMD = Ext->getInstanceMethod(MD->getSelector())) {
2291             Ignore = IMD->isUnavailable();
2292             break;
2293           }
2294       }
2295       if (!Ignore) {
2296         Diag(ImplD->getLocation(),
2297              diag::warn_objc_implementation_missing_designated_init_override)
2298           << MD->getSelector();
2299         Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
2300       }
2301     }
2302   }
2303 }
2304
2305 /// AddPropertyAttrs - Propagates attributes from a property to the
2306 /// implicitly-declared getter or setter for that property.
2307 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
2308                              ObjCPropertyDecl *Property) {
2309   // Should we just clone all attributes over?
2310   for (const auto *A : Property->attrs()) {
2311     if (isa<DeprecatedAttr>(A) ||
2312         isa<UnavailableAttr>(A) ||
2313         isa<AvailabilityAttr>(A))
2314       PropertyMethod->addAttr(A->clone(S.Context));
2315   }
2316 }
2317
2318 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
2319 /// have the property type and issue diagnostics if they don't.
2320 /// Also synthesize a getter/setter method if none exist (and update the
2321 /// appropriate lookup tables.
2322 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
2323   ObjCMethodDecl *GetterMethod, *SetterMethod;
2324   ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
2325   if (CD->isInvalidDecl())
2326     return;
2327
2328   bool IsClassProperty = property->isClassProperty();
2329   GetterMethod = IsClassProperty ?
2330     CD->getClassMethod(property->getGetterName()) :
2331     CD->getInstanceMethod(property->getGetterName());
2332
2333   // if setter or getter is not found in class extension, it might be
2334   // in the primary class.
2335   if (!GetterMethod)
2336     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2337       if (CatDecl->IsClassExtension())
2338         GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2339                          getClassMethod(property->getGetterName()) :
2340                        CatDecl->getClassInterface()->
2341                          getInstanceMethod(property->getGetterName());
2342
2343   SetterMethod = IsClassProperty ?
2344                  CD->getClassMethod(property->getSetterName()) :
2345                  CD->getInstanceMethod(property->getSetterName());
2346   if (!SetterMethod)
2347     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2348       if (CatDecl->IsClassExtension())
2349         SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2350                           getClassMethod(property->getSetterName()) :
2351                        CatDecl->getClassInterface()->
2352                           getInstanceMethod(property->getSetterName());
2353   DiagnosePropertyAccessorMismatch(property, GetterMethod,
2354                                    property->getLocation());
2355
2356   if (!property->isReadOnly() && SetterMethod) {
2357     if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
2358         Context.VoidTy)
2359       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2360     if (SetterMethod->param_size() != 1 ||
2361         !Context.hasSameUnqualifiedType(
2362           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2363           property->getType().getNonReferenceType())) {
2364       Diag(property->getLocation(),
2365            diag::warn_accessor_property_type_mismatch)
2366         << property->getDeclName()
2367         << SetterMethod->getSelector();
2368       Diag(SetterMethod->getLocation(), diag::note_declared_at);
2369     }
2370   }
2371
2372   // Synthesize getter/setter methods if none exist.
2373   // Find the default getter and if one not found, add one.
2374   // FIXME: The synthesized property we set here is misleading. We almost always
2375   // synthesize these methods unless the user explicitly provided prototypes
2376   // (which is odd, but allowed). Sema should be typechecking that the
2377   // declarations jive in that situation (which it is not currently).
2378   if (!GetterMethod) {
2379     // No instance/class method of same name as property getter name was found.
2380     // Declare a getter method and add it to the list of methods
2381     // for this class.
2382     SourceLocation Loc = property->getLocation();
2383
2384     // The getter returns the declared property type with all qualifiers
2385     // removed.
2386     QualType resultTy = property->getType().getAtomicUnqualifiedType();
2387
2388     // If the property is null_resettable, the getter returns nonnull.
2389     if (property->getPropertyAttributes() &
2390         ObjCPropertyDecl::OBJC_PR_null_resettable) {
2391       QualType modifiedTy = resultTy;
2392       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
2393         if (*nullability == NullabilityKind::Unspecified)
2394           resultTy = Context.getAttributedType(attr::TypeNonNull,
2395                                                modifiedTy, modifiedTy);
2396       }
2397     }
2398
2399     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
2400                              property->getGetterName(),
2401                              resultTy, nullptr, CD,
2402                              !IsClassProperty, /*isVariadic=*/false,
2403                              /*isPropertyAccessor=*/true,
2404                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2405                              (property->getPropertyImplementation() ==
2406                               ObjCPropertyDecl::Optional) ?
2407                              ObjCMethodDecl::Optional :
2408                              ObjCMethodDecl::Required);
2409     CD->addDecl(GetterMethod);
2410
2411     AddPropertyAttrs(*this, GetterMethod, property);
2412
2413     if (property->hasAttr<NSReturnsNotRetainedAttr>())
2414       GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2415                                                                      Loc));
2416
2417     if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2418       GetterMethod->addAttr(
2419         ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2420
2421     if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2422       GetterMethod->addAttr(
2423           SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2424                                       SA->getName(), Loc));
2425
2426     if (getLangOpts().ObjCAutoRefCount)
2427       CheckARCMethodDecl(GetterMethod);
2428   } else
2429     // A user declared getter will be synthesize when @synthesize of
2430     // the property with the same name is seen in the @implementation
2431     GetterMethod->setPropertyAccessor(true);
2432   property->setGetterMethodDecl(GetterMethod);
2433
2434   // Skip setter if property is read-only.
2435   if (!property->isReadOnly()) {
2436     // Find the default setter and if one not found, add one.
2437     if (!SetterMethod) {
2438       // No instance/class method of same name as property setter name was
2439       // found.
2440       // Declare a setter method and add it to the list of methods
2441       // for this class.
2442       SourceLocation Loc = property->getLocation();
2443
2444       SetterMethod =
2445         ObjCMethodDecl::Create(Context, Loc, Loc,
2446                                property->getSetterName(), Context.VoidTy,
2447                                nullptr, CD, !IsClassProperty,
2448                                /*isVariadic=*/false,
2449                                /*isPropertyAccessor=*/true,
2450                                /*isImplicitlyDeclared=*/true,
2451                                /*isDefined=*/false,
2452                                (property->getPropertyImplementation() ==
2453                                 ObjCPropertyDecl::Optional) ?
2454                                 ObjCMethodDecl::Optional :
2455                                 ObjCMethodDecl::Required);
2456
2457       // Remove all qualifiers from the setter's parameter type.
2458       QualType paramTy =
2459           property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
2460
2461       // If the property is null_resettable, the setter accepts a
2462       // nullable value.
2463       if (property->getPropertyAttributes() &
2464           ObjCPropertyDecl::OBJC_PR_null_resettable) {
2465         QualType modifiedTy = paramTy;
2466         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2467           if (*nullability == NullabilityKind::Unspecified)
2468             paramTy = Context.getAttributedType(attr::TypeNullable,
2469                                                 modifiedTy, modifiedTy);
2470         }
2471       }
2472
2473       // Invent the arguments for the setter. We don't bother making a
2474       // nice name for the argument.
2475       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2476                                                   Loc, Loc,
2477                                                   property->getIdentifier(),
2478                                                   paramTy,
2479                                                   /*TInfo=*/nullptr,
2480                                                   SC_None,
2481                                                   nullptr);
2482       SetterMethod->setMethodParams(Context, Argument, None);
2483
2484       AddPropertyAttrs(*this, SetterMethod, property);
2485
2486       CD->addDecl(SetterMethod);
2487       if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2488         SetterMethod->addAttr(
2489             SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2490                                         SA->getName(), Loc));
2491       // It's possible for the user to have set a very odd custom
2492       // setter selector that causes it to have a method family.
2493       if (getLangOpts().ObjCAutoRefCount)
2494         CheckARCMethodDecl(SetterMethod);
2495     } else
2496       // A user declared setter will be synthesize when @synthesize of
2497       // the property with the same name is seen in the @implementation
2498       SetterMethod->setPropertyAccessor(true);
2499     property->setSetterMethodDecl(SetterMethod);
2500   }
2501   // Add any synthesized methods to the global pool. This allows us to
2502   // handle the following, which is supported by GCC (and part of the design).
2503   //
2504   // @interface Foo
2505   // @property double bar;
2506   // @end
2507   //
2508   // void thisIsUnfortunate() {
2509   //   id foo;
2510   //   double bar = [foo bar];
2511   // }
2512   //
2513   if (!IsClassProperty) {
2514     if (GetterMethod)
2515       AddInstanceMethodToGlobalPool(GetterMethod);
2516     if (SetterMethod)
2517       AddInstanceMethodToGlobalPool(SetterMethod);
2518   } else {
2519     if (GetterMethod)
2520       AddFactoryMethodToGlobalPool(GetterMethod);
2521     if (SetterMethod)
2522       AddFactoryMethodToGlobalPool(SetterMethod);
2523   }
2524
2525   ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2526   if (!CurrentClass) {
2527     if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2528       CurrentClass = Cat->getClassInterface();
2529     else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2530       CurrentClass = Impl->getClassInterface();
2531   }
2532   if (GetterMethod)
2533     CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2534   if (SetterMethod)
2535     CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2536 }
2537
2538 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2539                                        SourceLocation Loc,
2540                                        unsigned &Attributes,
2541                                        bool propertyInPrimaryClass) {
2542   // FIXME: Improve the reported location.
2543   if (!PDecl || PDecl->isInvalidDecl())
2544     return;
2545
2546   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2547       (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
2548     Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2549     << "readonly" << "readwrite";
2550
2551   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2552   QualType PropertyTy = PropertyDecl->getType();
2553
2554   // Check for copy or retain on non-object types.
2555   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
2556                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
2557       !PropertyTy->isObjCRetainableType() &&
2558       !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2559     Diag(Loc, diag::err_objc_property_requires_object)
2560       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
2561           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
2562     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
2563                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
2564     PropertyDecl->setInvalidDecl();
2565   }
2566
2567   // Check for assign on object types.
2568   if ((Attributes & ObjCDeclSpec::DQ_PR_assign) &&
2569       !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
2570       PropertyTy->isObjCRetainableType() &&
2571       !PropertyTy->isObjCARCImplicitlyUnretainedType()) {
2572     Diag(Loc, diag::warn_objc_property_assign_on_object);
2573   }
2574
2575   // Check for more than one of { assign, copy, retain }.
2576   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
2577     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2578       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2579         << "assign" << "copy";
2580       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2581     }
2582     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2583       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2584         << "assign" << "retain";
2585       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2586     }
2587     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2588       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2589         << "assign" << "strong";
2590       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2591     }
2592     if (getLangOpts().ObjCAutoRefCount  &&
2593         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2594       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2595         << "assign" << "weak";
2596       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2597     }
2598     if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2599       Diag(Loc, diag::warn_iboutletcollection_property_assign);
2600   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
2601     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2602       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2603         << "unsafe_unretained" << "copy";
2604       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2605     }
2606     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2607       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2608         << "unsafe_unretained" << "retain";
2609       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2610     }
2611     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2612       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2613         << "unsafe_unretained" << "strong";
2614       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2615     }
2616     if (getLangOpts().ObjCAutoRefCount  &&
2617         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2618       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2619         << "unsafe_unretained" << "weak";
2620       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2621     }
2622   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2623     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2624       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2625         << "copy" << "retain";
2626       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2627     }
2628     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2629       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2630         << "copy" << "strong";
2631       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2632     }
2633     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2634       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2635         << "copy" << "weak";
2636       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2637     }
2638   }
2639   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2640            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2641       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2642         << "retain" << "weak";
2643       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2644   }
2645   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2646            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2647       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2648         << "strong" << "weak";
2649       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2650   }
2651
2652   if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2653     // 'weak' and 'nonnull' are mutually exclusive.
2654     if (auto nullability = PropertyTy->getNullability(Context)) {
2655       if (*nullability == NullabilityKind::NonNull)
2656         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2657           << "nonnull" << "weak";
2658     }
2659   }
2660
2661   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
2662       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
2663       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2664         << "atomic" << "nonatomic";
2665       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
2666   }
2667
2668   // Warn if user supplied no assignment attribute, property is
2669   // readwrite, and this is an object type.
2670   if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
2671     if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
2672       // do nothing
2673     } else if (getLangOpts().ObjCAutoRefCount) {
2674       // With arc, @property definitions should default to strong when
2675       // not specified.
2676       PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
2677     } else if (PropertyTy->isObjCObjectPointerType()) {
2678         bool isAnyClassTy =
2679           (PropertyTy->isObjCClassType() ||
2680            PropertyTy->isObjCQualifiedClassType());
2681         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2682         // issue any warning.
2683         if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2684           ;
2685         else if (propertyInPrimaryClass) {
2686           // Don't issue warning on property with no life time in class
2687           // extension as it is inherited from property in primary class.
2688           // Skip this warning in gc-only mode.
2689           if (getLangOpts().getGC() != LangOptions::GCOnly)
2690             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2691
2692           // If non-gc code warn that this is likely inappropriate.
2693           if (getLangOpts().getGC() == LangOptions::NonGC)
2694             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2695         }
2696     }
2697
2698     // FIXME: Implement warning dependent on NSCopying being
2699     // implemented. See also:
2700     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2701     // (please trim this list while you are at it).
2702   }
2703
2704   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
2705       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
2706       && getLangOpts().getGC() == LangOptions::GCOnly
2707       && PropertyTy->isBlockPointerType())
2708     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2709   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2710            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2711            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2712            PropertyTy->isBlockPointerType())
2713       Diag(Loc, diag::warn_objc_property_retain_of_block);
2714
2715   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2716       (Attributes & ObjCDeclSpec::DQ_PR_setter))
2717     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2718 }