contrib/llvm/tools/clang/lib/Sema/SemaObjCProperty.cpp

   1 //===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  This file implements semantic analysis for Objective C @property and
  11 //  @synthesize declarations.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/Sema/SemaInternal.h"
  16 #include "clang/AST/ASTMutationListener.h"
  17 #include "clang/AST/DeclObjC.h"
  18 #include "clang/AST/ExprCXX.h"
  19 #include "clang/AST/ExprObjC.h"
  20 #include "clang/Basic/SourceManager.h"
  21 #include "clang/Lex/Lexer.h"
  22 #include "clang/Lex/Preprocessor.h"
  23 #include "clang/Sema/Initialization.h"
  24 #include "llvm/ADT/DenseSet.h"
  25 #include "llvm/ADT/SmallString.h"
  26
  27 using namespace clang;
  28
  29 //===----------------------------------------------------------------------===//
  30 // Grammar actions.
  31 //===----------------------------------------------------------------------===//
  32
  33 /// getImpliedARCOwnership - Given a set of property attributes and a
  34 /// type, infer an expected lifetime.  The type's ownership qualification
  35 /// is not considered.
  36 ///
  37 /// Returns OCL_None if the attributes as stated do not imply an ownership.
  38 /// Never returns OCL_Autoreleasing.
  39 static Qualifiers::ObjCLifetime getImpliedARCOwnership(
  40                                ObjCPropertyDecl::PropertyAttributeKind attrs,
  41                                                 QualType type) {
  42   // retain, strong, copy, weak, and unsafe_unretained are only legal
  43   // on properties of retainable pointer type.
  44   if (attrs & (ObjCPropertyDecl::OBJC_PR_retain |
  45                ObjCPropertyDecl::OBJC_PR_strong |
  46                ObjCPropertyDecl::OBJC_PR_copy)) {
  47     return Qualifiers::OCL_Strong;
  48   } else if (attrs & ObjCPropertyDecl::OBJC_PR_weak) {
  49     return Qualifiers::OCL_Weak;
  50   } else if (attrs & ObjCPropertyDecl::OBJC_PR_unsafe_unretained) {
  51     return Qualifiers::OCL_ExplicitNone;
  52   }
  53
  54   // assign can appear on other types, so we have to check the
  55   // property type.
  56   if (attrs & ObjCPropertyDecl::OBJC_PR_assign &&
  57       type->isObjCRetainableType()) {
  58     return Qualifiers::OCL_ExplicitNone;
  59   }
  60
  61   return Qualifiers::OCL_None;
  62 }
  63
  64 /// Check the internal consistency of a property declaration with
  65 /// an explicit ownership qualifier.
  66 static void checkPropertyDeclWithOwnership(Sema &S,
  67                                            ObjCPropertyDecl *property) {
  68   if (property->isInvalidDecl()) return;
  69
  70   ObjCPropertyDecl::PropertyAttributeKind propertyKind
  71     = property->getPropertyAttributes();
  72   Qualifiers::ObjCLifetime propertyLifetime
  73     = property->getType().getObjCLifetime();
  74
  75   assert(propertyLifetime != Qualifiers::OCL_None);
  76
  77   Qualifiers::ObjCLifetime expectedLifetime
  78     = getImpliedARCOwnership(propertyKind, property->getType());
  79   if (!expectedLifetime) {
  80     // We have a lifetime qualifier but no dominating property
  81     // attribute.  That's okay, but restore reasonable invariants by
  82     // setting the property attribute according to the lifetime
  83     // qualifier.
  84     ObjCPropertyDecl::PropertyAttributeKind attr;
  85     if (propertyLifetime == Qualifiers::OCL_Strong) {
  86       attr = ObjCPropertyDecl::OBJC_PR_strong;
  87     } else if (propertyLifetime == Qualifiers::OCL_Weak) {
  88       attr = ObjCPropertyDecl::OBJC_PR_weak;
  89     } else {
  90       assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
  91       attr = ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
  92     }
  93     property->setPropertyAttributes(attr);
  94     return;
  95   }
  96
  97   if (propertyLifetime == expectedLifetime) return;
  98
  99   property->setInvalidDecl();
 100   S.Diag(property->getLocation(),
 101          diag::err_arc_inconsistent_property_ownership)
 102     << property->getDeclName()
 103     << expectedLifetime
 104     << propertyLifetime;
 105 }
 106
 107 /// \brief Check this Objective-C property against a property declared in the
 108 /// given protocol.
 109 static void
 110 CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
 111                              ObjCProtocolDecl *Proto,
 112                              llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
 113   // Have we seen this protocol before?
 114   if (!Known.insert(Proto).second)
 115     return;
 116
 117   // Look for a property with the same name.
 118   DeclContext::lookup_result R = Proto->lookup(Prop->getDeclName());
 119   for (unsigned I = 0, N = R.size(); I != N; ++I) {
 120     if (ObjCPropertyDecl *ProtoProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
 121       S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
 122       return;
 123     }
 124   }
 125
 126   // Check this property against any protocols we inherit.
 127   for (auto *P : Proto->protocols())
 128     CheckPropertyAgainstProtocol(S, Prop, P, Known);
 129 }
 130
 131 static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
 132   // In GC mode, just look for the __weak qualifier.
 133   if (S.getLangOpts().getGC() != LangOptions::NonGC) {
 134     if (T.isObjCGCWeak()) return ObjCDeclSpec::DQ_PR_weak;
 135
 136   // In ARC/MRC, look for an explicit ownership qualifier.
 137   // For some reason, this only applies to __weak.
 138   } else if (auto ownership = T.getObjCLifetime()) {
 139     switch (ownership) {
 140     case Qualifiers::OCL_Weak:
 141       return ObjCDeclSpec::DQ_PR_weak;
 142     case Qualifiers::OCL_Strong:
 143       return ObjCDeclSpec::DQ_PR_strong;
 144     case Qualifiers::OCL_ExplicitNone:
 145       return ObjCDeclSpec::DQ_PR_unsafe_unretained;
 146     case Qualifiers::OCL_Autoreleasing:
 147     case Qualifiers::OCL_None:
 148       return 0;
 149     }
 150     llvm_unreachable("bad qualifier");
 151   }
 152
 153   return 0;
 154 }
 155
 156 static const unsigned OwnershipMask =
 157   (ObjCPropertyDecl::OBJC_PR_assign |
 158    ObjCPropertyDecl::OBJC_PR_retain |
 159    ObjCPropertyDecl::OBJC_PR_copy   |
 160    ObjCPropertyDecl::OBJC_PR_weak   |
 161    ObjCPropertyDecl::OBJC_PR_strong |
 162    ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 163
 164 static unsigned getOwnershipRule(unsigned attr) {
 165   unsigned result = attr & OwnershipMask;
 166
 167   // From an ownership perspective, assign and unsafe_unretained are
 168   // identical; make sure one also implies the other.
 169   if (result & (ObjCPropertyDecl::OBJC_PR_assign |
 170                 ObjCPropertyDecl::OBJC_PR_unsafe_unretained)) {
 171     result |= ObjCPropertyDecl::OBJC_PR_assign |
 172               ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
 173   }
 174
 175   return result;
 176 }
 177
 178 Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
 179                           SourceLocation LParenLoc,
 180                           FieldDeclarator &FD,
 181                           ObjCDeclSpec &ODS,
 182                           Selector GetterSel,
 183                           Selector SetterSel,
 184                           tok::ObjCKeywordKind MethodImplKind,
 185                           DeclContext *lexicalDC) {
 186   unsigned Attributes = ODS.getPropertyAttributes();
 187   FD.D.setObjCWeakProperty((Attributes & ObjCDeclSpec::DQ_PR_weak) != 0);
 188   TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
 189   QualType T = TSI->getType();
 190   if (!getOwnershipRule(Attributes)) {
 191     Attributes |= deducePropertyOwnershipFromType(*this, T);
 192   }
 193   bool isReadWrite = ((Attributes & ObjCDeclSpec::DQ_PR_readwrite) ||
 194                       // default is readwrite!
 195                       !(Attributes & ObjCDeclSpec::DQ_PR_readonly));
 196
 197   // Proceed with constructing the ObjCPropertyDecls.
 198   ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
 199   ObjCPropertyDecl *Res = nullptr;
 200   if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
 201     if (CDecl->IsClassExtension()) {
 202       Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
 203                                            FD,
 204                                            GetterSel, ODS.getGetterNameLoc(),
 205                                            SetterSel, ODS.getSetterNameLoc(),
 206                                            isReadWrite, Attributes,
 207                                            ODS.getPropertyAttributes(),
 208                                            T, TSI, MethodImplKind);
 209       if (!Res)
 210         return nullptr;
 211     }
 212   }
 213
 214   if (!Res) {
 215     Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
 216                              GetterSel, ODS.getGetterNameLoc(), SetterSel,
 217                              ODS.getSetterNameLoc(), isReadWrite, Attributes,
 218                              ODS.getPropertyAttributes(), T, TSI,
 219                              MethodImplKind);
 220     if (lexicalDC)
 221       Res->setLexicalDeclContext(lexicalDC);
 222   }
 223
 224   // Validate the attributes on the @property.
 225   CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
 226                               (isa<ObjCInterfaceDecl>(ClassDecl) ||
 227                                isa<ObjCProtocolDecl>(ClassDecl)));
 228
 229   // Check consistency if the type has explicit ownership qualification.
 230   if (Res->getType().getObjCLifetime())
 231     checkPropertyDeclWithOwnership(*this, Res);
 232
 233   llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
 234   if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
 235     // For a class, compare the property against a property in our superclass.
 236     bool FoundInSuper = false;
 237     ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
 238     while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
 239       DeclContext::lookup_result R = Super->lookup(Res->getDeclName());
 240       for (unsigned I = 0, N = R.size(); I != N; ++I) {
 241         if (ObjCPropertyDecl *SuperProp = dyn_cast<ObjCPropertyDecl>(R[I])) {
 242           DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
 243           FoundInSuper = true;
 244           break;
 245         }
 246       }
 247       if (FoundInSuper)
 248         break;
 249       else
 250         CurrentInterfaceDecl = Super;
 251     }
 252
 253     if (FoundInSuper) {
 254       // Also compare the property against a property in our protocols.
 255       for (auto *P : CurrentInterfaceDecl->protocols()) {
 256         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 257       }
 258     } else {
 259       // Slower path: look in all protocols we referenced.
 260       for (auto *P : IFace->all_referenced_protocols()) {
 261         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 262       }
 263     }
 264   } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
 265     // We don't check if class extension. Because properties in class extension
 266     // are meant to override some of the attributes and checking has already done
 267     // when property in class extension is constructed.
 268     if (!Cat->IsClassExtension())
 269       for (auto *P : Cat->protocols())
 270         CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 271   } else {
 272     ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
 273     for (auto *P : Proto->protocols())
 274       CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
 275   }
 276
 277   ActOnDocumentableDecl(Res);
 278   return Res;
 279 }
 280
 281 static ObjCPropertyDecl::PropertyAttributeKind
 282 makePropertyAttributesAsWritten(unsigned Attributes) {
 283   unsigned attributesAsWritten = 0;
 284   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
 285     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readonly;
 286   if (Attributes & ObjCDeclSpec::DQ_PR_readwrite)
 287     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_readwrite;
 288   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
 289     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_getter;
 290   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
 291     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_setter;
 292   if (Attributes & ObjCDeclSpec::DQ_PR_assign)
 293     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_assign;
 294   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
 295     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_retain;
 296   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
 297     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_strong;
 298   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
 299     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_weak;
 300   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
 301     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_copy;
 302   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 303     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_unsafe_unretained;
 304   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
 305     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_nonatomic;
 306   if (Attributes & ObjCDeclSpec::DQ_PR_atomic)
 307     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_atomic;
 308   if (Attributes & ObjCDeclSpec::DQ_PR_class)
 309     attributesAsWritten |= ObjCPropertyDecl::OBJC_PR_class;
 310
 311   return (ObjCPropertyDecl::PropertyAttributeKind)attributesAsWritten;
 312 }
 313
 314 static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
 315                                  SourceLocation LParenLoc, SourceLocation &Loc) {
 316   if (LParenLoc.isMacroID())
 317     return false;
 318
 319   SourceManager &SM = Context.getSourceManager();
 320   std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
 321   // Try to load the file buffer.
 322   bool invalidTemp = false;
 323   StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
 324   if (invalidTemp)
 325     return false;
 326   const char *tokenBegin = file.data() + locInfo.second;
 327
 328   // Lex from the start of the given location.
 329   Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
 330               Context.getLangOpts(),
 331               file.begin(), tokenBegin, file.end());
 332   Token Tok;
 333   do {
 334     lexer.LexFromRawLexer(Tok);
 335     if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
 336       Loc = Tok.getLocation();
 337       return true;
 338     }
 339   } while (Tok.isNot(tok::r_paren));
 340   return false;
 341 }
 342
 343 /// Check for a mismatch in the atomicity of the given properties.
 344 static void checkAtomicPropertyMismatch(Sema &S,
 345                                         ObjCPropertyDecl *OldProperty,
 346                                         ObjCPropertyDecl *NewProperty,
 347                                         bool PropagateAtomicity) {
 348   // If the atomicity of both matches, we're done.
 349   bool OldIsAtomic =
 350     (OldProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
 351       == 0;
 352   bool NewIsAtomic =
 353     (NewProperty->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
 354       == 0;
 355   if (OldIsAtomic == NewIsAtomic) return;
 356
 357   // Determine whether the given property is readonly and implicitly
 358   // atomic.
 359   auto isImplicitlyReadonlyAtomic = [](ObjCPropertyDecl *Property) -> bool {
 360     // Is it readonly?
 361     auto Attrs = Property->getPropertyAttributes();
 362     if ((Attrs & ObjCPropertyDecl::OBJC_PR_readonly) == 0) return false;
 363
 364     // Is it nonatomic?
 365     if (Attrs & ObjCPropertyDecl::OBJC_PR_nonatomic) return false;
 366
 367     // Was 'atomic' specified directly?
 368     if (Property->getPropertyAttributesAsWritten() &
 369           ObjCPropertyDecl::OBJC_PR_atomic)
 370       return false;
 371
 372     return true;
 373   };
 374
 375   // If we're allowed to propagate atomicity, and the new property did
 376   // not specify atomicity at all, propagate.
 377   const unsigned AtomicityMask =
 378     (ObjCPropertyDecl::OBJC_PR_atomic | ObjCPropertyDecl::OBJC_PR_nonatomic);
 379   if (PropagateAtomicity &&
 380       ((NewProperty->getPropertyAttributesAsWritten() & AtomicityMask) == 0)) {
 381     unsigned Attrs = NewProperty->getPropertyAttributes();
 382     Attrs = Attrs & ~AtomicityMask;
 383     if (OldIsAtomic)
 384       Attrs |= ObjCPropertyDecl::OBJC_PR_atomic;
 385     else
 386       Attrs |= ObjCPropertyDecl::OBJC_PR_nonatomic;
 387
 388     NewProperty->overwritePropertyAttributes(Attrs);
 389     return;
 390   }
 391
 392   // One of the properties is atomic; if it's a readonly property, and
 393   // 'atomic' wasn't explicitly specified, we're okay.
 394   if ((OldIsAtomic && isImplicitlyReadonlyAtomic(OldProperty)) ||
 395       (NewIsAtomic && isImplicitlyReadonlyAtomic(NewProperty)))
 396     return;
 397
 398   // Diagnose the conflict.
 399   const IdentifierInfo *OldContextName;
 400   auto *OldDC = OldProperty->getDeclContext();
 401   if (auto Category = dyn_cast<ObjCCategoryDecl>(OldDC))
 402     OldContextName = Category->getClassInterface()->getIdentifier();
 403   else
 404     OldContextName = cast<ObjCContainerDecl>(OldDC)->getIdentifier();
 405
 406   S.Diag(NewProperty->getLocation(), diag::warn_property_attribute)
 407     << NewProperty->getDeclName() << "atomic"
 408     << OldContextName;
 409   S.Diag(OldProperty->getLocation(), diag::note_property_declare);
 410 }
 411
 412 ObjCPropertyDecl *
 413 Sema::HandlePropertyInClassExtension(Scope *S,
 414                                      SourceLocation AtLoc,
 415                                      SourceLocation LParenLoc,
 416                                      FieldDeclarator &FD,
 417                                      Selector GetterSel,
 418                                      SourceLocation GetterNameLoc,
 419                                      Selector SetterSel,
 420                                      SourceLocation SetterNameLoc,
 421                                      const bool isReadWrite,
 422                                      unsigned &Attributes,
 423                                      const unsigned AttributesAsWritten,
 424                                      QualType T,
 425                                      TypeSourceInfo *TSI,
 426                                      tok::ObjCKeywordKind MethodImplKind) {
 427   ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
 428   // Diagnose if this property is already in continuation class.
 429   DeclContext *DC = CurContext;
 430   IdentifierInfo *PropertyId = FD.D.getIdentifier();
 431   ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
 432
 433   // We need to look in the @interface to see if the @property was
 434   // already declared.
 435   if (!CCPrimary) {
 436     Diag(CDecl->getLocation(), diag::err_continuation_class);
 437     return nullptr;
 438   }
 439
 440   bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
 441                          (Attributes & ObjCDeclSpec::DQ_PR_class);
 442
 443   // Find the property in the extended class's primary class or
 444   // extensions.
 445   ObjCPropertyDecl *PIDecl = CCPrimary->FindPropertyVisibleInPrimaryClass(
 446       PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty));
 447
 448   // If we found a property in an extension, complain.
 449   if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
 450     Diag(AtLoc, diag::err_duplicate_property);
 451     Diag(PIDecl->getLocation(), diag::note_property_declare);
 452     return nullptr;
 453   }
 454
 455   // Check for consistency with the previous declaration, if there is one.
 456   if (PIDecl) {
 457     // A readonly property declared in the primary class can be refined
 458     // by adding a readwrite property within an extension.
 459     // Anything else is an error.
 460     if (!(PIDecl->isReadOnly() && isReadWrite)) {
 461       // Tailor the diagnostics for the common case where a readwrite
 462       // property is declared both in the @interface and the continuation.
 463       // This is a common error where the user often intended the original
 464       // declaration to be readonly.
 465       unsigned diag =
 466         (Attributes & ObjCDeclSpec::DQ_PR_readwrite) &&
 467         (PIDecl->getPropertyAttributesAsWritten() &
 468            ObjCPropertyDecl::OBJC_PR_readwrite)
 469         ? diag::err_use_continuation_class_redeclaration_readwrite
 470         : diag::err_use_continuation_class;
 471       Diag(AtLoc, diag)
 472         << CCPrimary->getDeclName();
 473       Diag(PIDecl->getLocation(), diag::note_property_declare);
 474       return nullptr;
 475     }
 476
 477     // Check for consistency of getters.
 478     if (PIDecl->getGetterName() != GetterSel) {
 479      // If the getter was written explicitly, complain.
 480       if (AttributesAsWritten & ObjCDeclSpec::DQ_PR_getter) {
 481         Diag(AtLoc, diag::warn_property_redecl_getter_mismatch)
 482           << PIDecl->getGetterName() << GetterSel;
 483         Diag(PIDecl->getLocation(), diag::note_property_declare);
 484       }
 485
 486       // Always adopt the getter from the original declaration.
 487       GetterSel = PIDecl->getGetterName();
 488       Attributes |= ObjCDeclSpec::DQ_PR_getter;
 489     }
 490
 491     // Check consistency of ownership.
 492     unsigned ExistingOwnership
 493       = getOwnershipRule(PIDecl->getPropertyAttributes());
 494     unsigned NewOwnership = getOwnershipRule(Attributes);
 495     if (ExistingOwnership && NewOwnership != ExistingOwnership) {
 496       // If the ownership was written explicitly, complain.
 497       if (getOwnershipRule(AttributesAsWritten)) {
 498         Diag(AtLoc, diag::warn_property_attr_mismatch);
 499         Diag(PIDecl->getLocation(), diag::note_property_declare);
 500       }
 501
 502       // Take the ownership from the original property.
 503       Attributes = (Attributes & ~OwnershipMask) | ExistingOwnership;
 504     }
 505
 506     // If the redeclaration is 'weak' but the original property is not,
 507     if ((Attributes & ObjCPropertyDecl::OBJC_PR_weak) &&
 508         !(PIDecl->getPropertyAttributesAsWritten()
 509             & ObjCPropertyDecl::OBJC_PR_weak) &&
 510         PIDecl->getType()->getAs<ObjCObjectPointerType>() &&
 511         PIDecl->getType().getObjCLifetime() == Qualifiers::OCL_None) {
 512       Diag(AtLoc, diag::warn_property_implicitly_mismatched);
 513       Diag(PIDecl->getLocation(), diag::note_property_declare);
 514     }
 515   }
 516
 517   // Create a new ObjCPropertyDecl with the DeclContext being
 518   // the class extension.
 519   ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
 520                                                FD, GetterSel, GetterNameLoc,
 521                                                SetterSel, SetterNameLoc,
 522                                                isReadWrite,
 523                                                Attributes, AttributesAsWritten,
 524                                                T, TSI, MethodImplKind, DC);
 525
 526   // If there was no declaration of a property with the same name in
 527   // the primary class, we're done.
 528   if (!PIDecl) {
 529     ProcessPropertyDecl(PDecl);
 530     return PDecl;
 531   }
 532
 533   if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
 534     bool IncompatibleObjC = false;
 535     QualType ConvertedType;
 536     // Relax the strict type matching for property type in continuation class.
 537     // Allow property object type of continuation class to be different as long
 538     // as it narrows the object type in its primary class property. Note that
 539     // this conversion is safe only because the wider type is for a 'readonly'
 540     // property in primary class and 'narrowed' type for a 'readwrite' property
 541     // in continuation class.
 542     QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
 543     QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
 544     if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
 545         !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
 546         (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
 547                                   ConvertedType, IncompatibleObjC))
 548         || IncompatibleObjC) {
 549       Diag(AtLoc,
 550           diag::err_type_mismatch_continuation_class) << PDecl->getType();
 551       Diag(PIDecl->getLocation(), diag::note_property_declare);
 552       return nullptr;
 553     }
 554   }
 555
 556   // Check that atomicity of property in class extension matches the previous
 557   // declaration.
 558   checkAtomicPropertyMismatch(*this, PIDecl, PDecl, true);
 559
 560   // Make sure getter/setter are appropriately synthesized.
 561   ProcessPropertyDecl(PDecl);
 562   return PDecl;
 563 }
 564
 565 ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
 566                                            ObjCContainerDecl *CDecl,
 567                                            SourceLocation AtLoc,
 568                                            SourceLocation LParenLoc,
 569                                            FieldDeclarator &FD,
 570                                            Selector GetterSel,
 571                                            SourceLocation GetterNameLoc,
 572                                            Selector SetterSel,
 573                                            SourceLocation SetterNameLoc,
 574                                            const bool isReadWrite,
 575                                            const unsigned Attributes,
 576                                            const unsigned AttributesAsWritten,
 577                                            QualType T,
 578                                            TypeSourceInfo *TInfo,
 579                                            tok::ObjCKeywordKind MethodImplKind,
 580                                            DeclContext *lexicalDC){
 581   IdentifierInfo *PropertyId = FD.D.getIdentifier();
 582
 583   // Property defaults to 'assign' if it is readwrite, unless this is ARC
 584   // and the type is retainable.
 585   bool isAssign;
 586   if (Attributes & (ObjCDeclSpec::DQ_PR_assign |
 587                     ObjCDeclSpec::DQ_PR_unsafe_unretained)) {
 588     isAssign = true;
 589   } else if (getOwnershipRule(Attributes) || !isReadWrite) {
 590     isAssign = false;
 591   } else {
 592     isAssign = (!getLangOpts().ObjCAutoRefCount ||
 593                 !T->isObjCRetainableType());
 594   }
 595
 596   // Issue a warning if property is 'assign' as default and its
 597   // object, which is gc'able conforms to NSCopying protocol
 598   if (getLangOpts().getGC() != LangOptions::NonGC &&
 599       isAssign && !(Attributes & ObjCDeclSpec::DQ_PR_assign)) {
 600     if (const ObjCObjectPointerType *ObjPtrTy =
 601           T->getAs<ObjCObjectPointerType>()) {
 602       ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
 603       if (IDecl)
 604         if (ObjCProtocolDecl* PNSCopying =
 605             LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
 606           if (IDecl->ClassImplementsProtocol(PNSCopying, true))
 607             Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
 608     }
 609   }
 610
 611   if (T->isObjCObjectType()) {
 612     SourceLocation StarLoc = TInfo->getTypeLoc().getLocEnd();
 613     StarLoc = getLocForEndOfToken(StarLoc);
 614     Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
 615       << FixItHint::CreateInsertion(StarLoc, "*");
 616     T = Context.getObjCObjectPointerType(T);
 617     SourceLocation TLoc = TInfo->getTypeLoc().getLocStart();
 618     TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
 619   }
 620
 621   DeclContext *DC = cast<DeclContext>(CDecl);
 622   ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
 623                                                      FD.D.getIdentifierLoc(),
 624                                                      PropertyId, AtLoc,
 625                                                      LParenLoc, T, TInfo);
 626
 627   bool isClassProperty = (AttributesAsWritten & ObjCDeclSpec::DQ_PR_class) ||
 628                          (Attributes & ObjCDeclSpec::DQ_PR_class);
 629   // Class property and instance property can have the same name.
 630   if (ObjCPropertyDecl *prevDecl = ObjCPropertyDecl::findPropertyDecl(
 631           DC, PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty))) {
 632     Diag(PDecl->getLocation(), diag::err_duplicate_property);
 633     Diag(prevDecl->getLocation(), diag::note_property_declare);
 634     PDecl->setInvalidDecl();
 635   }
 636   else {
 637     DC->addDecl(PDecl);
 638     if (lexicalDC)
 639       PDecl->setLexicalDeclContext(lexicalDC);
 640   }
 641
 642   if (T->isArrayType() || T->isFunctionType()) {
 643     Diag(AtLoc, diag::err_property_type) << T;
 644     PDecl->setInvalidDecl();
 645   }
 646
 647   ProcessDeclAttributes(S, PDecl, FD.D);
 648
 649   // Regardless of setter/getter attribute, we save the default getter/setter
 650   // selector names in anticipation of declaration of setter/getter methods.
 651   PDecl->setGetterName(GetterSel, GetterNameLoc);
 652   PDecl->setSetterName(SetterSel, SetterNameLoc);
 653   PDecl->setPropertyAttributesAsWritten(
 654                           makePropertyAttributesAsWritten(AttributesAsWritten));
 655
 656   if (Attributes & ObjCDeclSpec::DQ_PR_readonly)
 657     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readonly);
 658
 659   if (Attributes & ObjCDeclSpec::DQ_PR_getter)
 660     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_getter);
 661
 662   if (Attributes & ObjCDeclSpec::DQ_PR_setter)
 663     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_setter);
 664
 665   if (isReadWrite)
 666     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_readwrite);
 667
 668   if (Attributes & ObjCDeclSpec::DQ_PR_retain)
 669     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_retain);
 670
 671   if (Attributes & ObjCDeclSpec::DQ_PR_strong)
 672     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 673
 674   if (Attributes & ObjCDeclSpec::DQ_PR_weak)
 675     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
 676
 677   if (Attributes & ObjCDeclSpec::DQ_PR_copy)
 678     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_copy);
 679
 680   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 681     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 682
 683   if (isAssign)
 684     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
 685
 686   // In the semantic attributes, one of nonatomic or atomic is always set.
 687   if (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)
 688     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nonatomic);
 689   else
 690     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_atomic);
 691
 692   // 'unsafe_unretained' is alias for 'assign'.
 693   if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained)
 694     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_assign);
 695   if (isAssign)
 696     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 697
 698   if (MethodImplKind == tok::objc_required)
 699     PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
 700   else if (MethodImplKind == tok::objc_optional)
 701     PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
 702
 703   if (Attributes & ObjCDeclSpec::DQ_PR_nullability)
 704     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_nullability);
 705
 706   if (Attributes & ObjCDeclSpec::DQ_PR_null_resettable)
 707     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_null_resettable);
 708
 709  if (Attributes & ObjCDeclSpec::DQ_PR_class)
 710     PDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_class);
 711
 712   return PDecl;
 713 }
 714
 715 static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
 716                                  ObjCPropertyDecl *property,
 717                                  ObjCIvarDecl *ivar) {
 718   if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
 719
 720   QualType ivarType = ivar->getType();
 721   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
 722
 723   // The lifetime implied by the property's attributes.
 724   Qualifiers::ObjCLifetime propertyLifetime =
 725     getImpliedARCOwnership(property->getPropertyAttributes(),
 726                            property->getType());
 727
 728   // We're fine if they match.
 729   if (propertyLifetime == ivarLifetime) return;
 730
 731   // None isn't a valid lifetime for an object ivar in ARC, and
 732   // __autoreleasing is never valid; don't diagnose twice.
 733   if ((ivarLifetime == Qualifiers::OCL_None &&
 734        S.getLangOpts().ObjCAutoRefCount) ||
 735       ivarLifetime == Qualifiers::OCL_Autoreleasing)
 736     return;
 737
 738   // If the ivar is private, and it's implicitly __unsafe_unretained
 739   // becaues of its type, then pretend it was actually implicitly
 740   // __strong.  This is only sound because we're processing the
 741   // property implementation before parsing any method bodies.
 742   if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
 743       propertyLifetime == Qualifiers::OCL_Strong &&
 744       ivar->getAccessControl() == ObjCIvarDecl::Private) {
 745     SplitQualType split = ivarType.split();
 746     if (split.Quals.hasObjCLifetime()) {
 747       assert(ivarType->isObjCARCImplicitlyUnretainedType());
 748       split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
 749       ivarType = S.Context.getQualifiedType(split);
 750       ivar->setType(ivarType);
 751       return;
 752     }
 753   }
 754
 755   switch (propertyLifetime) {
 756   case Qualifiers::OCL_Strong:
 757     S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
 758       << property->getDeclName()
 759       << ivar->getDeclName()
 760       << ivarLifetime;
 761     break;
 762
 763   case Qualifiers::OCL_Weak:
 764     S.Diag(ivar->getLocation(), diag::err_weak_property)
 765       << property->getDeclName()
 766       << ivar->getDeclName();
 767     break;
 768
 769   case Qualifiers::OCL_ExplicitNone:
 770     S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
 771       << property->getDeclName()
 772       << ivar->getDeclName()
 773       << ((property->getPropertyAttributesAsWritten()
 774            & ObjCPropertyDecl::OBJC_PR_assign) != 0);
 775     break;
 776
 777   case Qualifiers::OCL_Autoreleasing:
 778     llvm_unreachable("properties cannot be autoreleasing");
 779
 780   case Qualifiers::OCL_None:
 781     // Any other property should be ignored.
 782     return;
 783   }
 784
 785   S.Diag(property->getLocation(), diag::note_property_declare);
 786   if (propertyImplLoc.isValid())
 787     S.Diag(propertyImplLoc, diag::note_property_synthesize);
 788 }
 789
 790 /// setImpliedPropertyAttributeForReadOnlyProperty -
 791 /// This routine evaludates life-time attributes for a 'readonly'
 792 /// property with no known lifetime of its own, using backing
 793 /// 'ivar's attribute, if any. If no backing 'ivar', property's
 794 /// life-time is assumed 'strong'.
 795 static void setImpliedPropertyAttributeForReadOnlyProperty(
 796               ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
 797   Qualifiers::ObjCLifetime propertyLifetime =
 798     getImpliedARCOwnership(property->getPropertyAttributes(),
 799                            property->getType());
 800   if (propertyLifetime != Qualifiers::OCL_None)
 801     return;
 802
 803   if (!ivar) {
 804     // if no backing ivar, make property 'strong'.
 805     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 806     return;
 807   }
 808   // property assumes owenership of backing ivar.
 809   QualType ivarType = ivar->getType();
 810   Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
 811   if (ivarLifetime == Qualifiers::OCL_Strong)
 812     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
 813   else if (ivarLifetime == Qualifiers::OCL_Weak)
 814     property->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_weak);
 815 }
 816
 817 static bool
 818 isIncompatiblePropertyAttribute(unsigned Attr1, unsigned Attr2,
 819                                 ObjCPropertyDecl::PropertyAttributeKind Kind) {
 820   return (Attr1 & Kind) != (Attr2 & Kind);
 821 }
 822
 823 static bool areIncompatiblePropertyAttributes(unsigned Attr1, unsigned Attr2,
 824                                               unsigned Kinds) {
 825   return ((Attr1 & Kinds) != 0) != ((Attr2 & Kinds) != 0);
 826 }
 827
 828 /// SelectPropertyForSynthesisFromProtocols - Finds the most appropriate
 829 /// property declaration that should be synthesised in all of the inherited
 830 /// protocols. It also diagnoses properties declared in inherited protocols with
 831 /// mismatched types or attributes, since any of them can be candidate for
 832 /// synthesis.
 833 static ObjCPropertyDecl *
 834 SelectPropertyForSynthesisFromProtocols(Sema &S, SourceLocation AtLoc,
 835                                         ObjCInterfaceDecl *ClassDecl,
 836                                         ObjCPropertyDecl *Property) {
 837   assert(isa<ObjCProtocolDecl>(Property->getDeclContext()) &&
 838          "Expected a property from a protocol");
 839   ObjCInterfaceDecl::ProtocolPropertySet ProtocolSet;
 840   ObjCInterfaceDecl::PropertyDeclOrder Properties;
 841   for (const auto *PI : ClassDecl->all_referenced_protocols()) {
 842     if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
 843       PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
 844                                                 Properties);
 845   }
 846   if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass()) {
 847     while (SDecl) {
 848       for (const auto *PI : SDecl->all_referenced_protocols()) {
 849         if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
 850           PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
 851                                                     Properties);
 852       }
 853       SDecl = SDecl->getSuperClass();
 854     }
 855   }
 856
 857   if (Properties.empty())
 858     return Property;
 859
 860   ObjCPropertyDecl *OriginalProperty = Property;
 861   size_t SelectedIndex = 0;
 862   for (const auto &Prop : llvm::enumerate(Properties)) {
 863     // Select the 'readwrite' property if such property exists.
 864     if (Property->isReadOnly() && !Prop.value()->isReadOnly()) {
 865       Property = Prop.value();
 866       SelectedIndex = Prop.index();
 867     }
 868   }
 869   if (Property != OriginalProperty) {
 870     // Check that the old property is compatible with the new one.
 871     Properties[SelectedIndex] = OriginalProperty;
 872   }
 873
 874   QualType RHSType = S.Context.getCanonicalType(Property->getType());
 875   unsigned OriginalAttributes = Property->getPropertyAttributes();
 876   enum MismatchKind {
 877     IncompatibleType = 0,
 878     HasNoExpectedAttribute,
 879     HasUnexpectedAttribute,
 880     DifferentGetter,
 881     DifferentSetter
 882   };
 883   // Represents a property from another protocol that conflicts with the
 884   // selected declaration.
 885   struct MismatchingProperty {
 886     const ObjCPropertyDecl *Prop;
 887     MismatchKind Kind;
 888     StringRef AttributeName;
 889   };
 890   SmallVector<MismatchingProperty, 4> Mismatches;
 891   for (ObjCPropertyDecl *Prop : Properties) {
 892     // Verify the property attributes.
 893     unsigned Attr = Prop->getPropertyAttributes();
 894     if (Attr != OriginalAttributes) {
 895       auto Diag = [&](bool OriginalHasAttribute, StringRef AttributeName) {
 896         MismatchKind Kind = OriginalHasAttribute ? HasNoExpectedAttribute
 897                                                  : HasUnexpectedAttribute;
 898         Mismatches.push_back({Prop, Kind, AttributeName});
 899       };
 900       if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 901                                           ObjCPropertyDecl::OBJC_PR_copy)) {
 902         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_copy, "copy");
 903         continue;
 904       }
 905       if (areIncompatiblePropertyAttributes(
 906               OriginalAttributes, Attr, ObjCPropertyDecl::OBJC_PR_retain |
 907                                             ObjCPropertyDecl::OBJC_PR_strong)) {
 908         Diag(OriginalAttributes & (ObjCPropertyDecl::OBJC_PR_retain |
 909                                    ObjCPropertyDecl::OBJC_PR_strong),
 910              "retain (or strong)");
 911         continue;
 912       }
 913       if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 914                                           ObjCPropertyDecl::OBJC_PR_atomic)) {
 915         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_atomic, "atomic");
 916         continue;
 917       }
 918     }
 919     if (Property->getGetterName() != Prop->getGetterName()) {
 920       Mismatches.push_back({Prop, DifferentGetter, ""});
 921       continue;
 922     }
 923     if (!Property->isReadOnly() && !Prop->isReadOnly() &&
 924         Property->getSetterName() != Prop->getSetterName()) {
 925       Mismatches.push_back({Prop, DifferentSetter, ""});
 926       continue;
 927     }
 928     QualType LHSType = S.Context.getCanonicalType(Prop->getType());
 929     if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
 930       bool IncompatibleObjC = false;
 931       QualType ConvertedType;
 932       if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
 933           || IncompatibleObjC) {
 934         Mismatches.push_back({Prop, IncompatibleType, ""});
 935         continue;
 936       }
 937     }
 938   }
 939
 940   if (Mismatches.empty())
 941     return Property;
 942
 943   // Diagnose incompability.
 944   {
 945     bool HasIncompatibleAttributes = false;
 946     for (const auto &Note : Mismatches)
 947       HasIncompatibleAttributes =
 948           Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
 949     // Promote the warning to an error if there are incompatible attributes or
 950     // incompatible types together with readwrite/readonly incompatibility.
 951     auto Diag = S.Diag(Property->getLocation(),
 952                        Property != OriginalProperty || HasIncompatibleAttributes
 953                            ? diag::err_protocol_property_mismatch
 954                            : diag::warn_protocol_property_mismatch);
 955     Diag << Mismatches[0].Kind;
 956     switch (Mismatches[0].Kind) {
 957     case IncompatibleType:
 958       Diag << Property->getType();
 959       break;
 960     case HasNoExpectedAttribute:
 961     case HasUnexpectedAttribute:
 962       Diag << Mismatches[0].AttributeName;
 963       break;
 964     case DifferentGetter:
 965       Diag << Property->getGetterName();
 966       break;
 967     case DifferentSetter:
 968       Diag << Property->getSetterName();
 969       break;
 970     }
 971   }
 972   for (const auto &Note : Mismatches) {
 973     auto Diag =
 974         S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
 975         << Note.Kind;
 976     switch (Note.Kind) {
 977     case IncompatibleType:
 978       Diag << Note.Prop->getType();
 979       break;
 980     case HasNoExpectedAttribute:
 981     case HasUnexpectedAttribute:
 982       Diag << Note.AttributeName;
 983       break;
 984     case DifferentGetter:
 985       Diag << Note.Prop->getGetterName();
 986       break;
 987     case DifferentSetter:
 988       Diag << Note.Prop->getSetterName();
 989       break;
 990     }
 991   }
 992   if (AtLoc.isValid())
 993     S.Diag(AtLoc, diag::note_property_synthesize);
 994
 995   return Property;
 996 }
 997
 998 /// Determine whether any storage attributes were written on the property.
 999 static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
1000                                        ObjCPropertyQueryKind QueryKind) {
1001   if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
1002
1003   // If this is a readwrite property in a class extension that refines
1004   // a readonly property in the original class definition, check it as
1005   // well.
1006
1007   // If it's a readonly property, we're not interested.
1008   if (Prop->isReadOnly()) return false;
1009
1010   // Is it declared in an extension?
1011   auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
1012   if (!Category || !Category->IsClassExtension()) return false;
1013
1014   // Find the corresponding property in the primary class definition.
1015   auto OrigClass = Category->getClassInterface();
1016   for (auto Found : OrigClass->lookup(Prop->getDeclName())) {
1017     if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
1018       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1019   }
1020
1021   // Look through all of the protocols.
1022   for (const auto *Proto : OrigClass->all_referenced_protocols()) {
1023     if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
1024             Prop->getIdentifier(), QueryKind))
1025       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1026   }
1027
1028   return false;
1029 }
1030
1031 /// ActOnPropertyImplDecl - This routine performs semantic checks and
1032 /// builds the AST node for a property implementation declaration; declared
1033 /// as \@synthesize or \@dynamic.
1034 ///
1035 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
1036                                   SourceLocation AtLoc,
1037                                   SourceLocation PropertyLoc,
1038                                   bool Synthesize,
1039                                   IdentifierInfo *PropertyId,
1040                                   IdentifierInfo *PropertyIvar,
1041                                   SourceLocation PropertyIvarLoc,
1042                                   ObjCPropertyQueryKind QueryKind) {
1043   ObjCContainerDecl *ClassImpDecl =
1044     dyn_cast<ObjCContainerDecl>(CurContext);
1045   // Make sure we have a context for the property implementation declaration.
1046   if (!ClassImpDecl) {
1047     Diag(AtLoc, diag::err_missing_property_context);
1048     return nullptr;
1049   }
1050   if (PropertyIvarLoc.isInvalid())
1051     PropertyIvarLoc = PropertyLoc;
1052   SourceLocation PropertyDiagLoc = PropertyLoc;
1053   if (PropertyDiagLoc.isInvalid())
1054     PropertyDiagLoc = ClassImpDecl->getLocStart();
1055   ObjCPropertyDecl *property = nullptr;
1056   ObjCInterfaceDecl *IDecl = nullptr;
1057   // Find the class or category class where this property must have
1058   // a declaration.
1059   ObjCImplementationDecl *IC = nullptr;
1060   ObjCCategoryImplDecl *CatImplClass = nullptr;
1061   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
1062     IDecl = IC->getClassInterface();
1063     // We always synthesize an interface for an implementation
1064     // without an interface decl. So, IDecl is always non-zero.
1065     assert(IDecl &&
1066            "ActOnPropertyImplDecl - @implementation without @interface");
1067
1068     // Look for this property declaration in the @implementation's @interface
1069     property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
1070     if (!property) {
1071       Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
1072       return nullptr;
1073     }
1074     if (property->isClassProperty() && Synthesize) {
1075       Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
1076       return nullptr;
1077     }
1078     unsigned PIkind = property->getPropertyAttributesAsWritten();
1079     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
1080                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
1081       if (AtLoc.isValid())
1082         Diag(AtLoc, diag::warn_implicit_atomic_property);
1083       else
1084         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
1085       Diag(property->getLocation(), diag::note_property_declare);
1086     }
1087
1088     if (const ObjCCategoryDecl *CD =
1089         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
1090       if (!CD->IsClassExtension()) {
1091         Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
1092         Diag(property->getLocation(), diag::note_property_declare);
1093         return nullptr;
1094       }
1095     }
1096     if (Synthesize&&
1097         (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
1098         property->hasAttr<IBOutletAttr>() &&
1099         !AtLoc.isValid()) {
1100       bool ReadWriteProperty = false;
1101       // Search into the class extensions and see if 'readonly property is
1102       // redeclared 'readwrite', then no warning is to be issued.
1103       for (auto *Ext : IDecl->known_extensions()) {
1104         DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
1105         if (!R.empty())
1106           if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
1107             PIkind = ExtProp->getPropertyAttributesAsWritten();
1108             if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
1109               ReadWriteProperty = true;
1110               break;
1111             }
1112           }
1113       }
1114
1115       if (!ReadWriteProperty) {
1116         Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
1117             << property;
1118         SourceLocation readonlyLoc;
1119         if (LocPropertyAttribute(Context, "readonly",
1120                                  property->getLParenLoc(), readonlyLoc)) {
1121           SourceLocation endLoc =
1122             readonlyLoc.getLocWithOffset(strlen("readonly")-1);
1123           SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
1124           Diag(property->getLocation(),
1125                diag::note_auto_readonly_iboutlet_fixup_suggest) <<
1126           FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
1127         }
1128       }
1129     }
1130     if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
1131       property = SelectPropertyForSynthesisFromProtocols(*this, AtLoc, IDecl,
1132                                                          property);
1133
1134   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
1135     if (Synthesize) {
1136       Diag(AtLoc, diag::err_synthesize_category_decl);
1137       return nullptr;
1138     }
1139     IDecl = CatImplClass->getClassInterface();
1140     if (!IDecl) {
1141       Diag(AtLoc, diag::err_missing_property_interface);
1142       return nullptr;
1143     }
1144     ObjCCategoryDecl *Category =
1145     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
1146
1147     // If category for this implementation not found, it is an error which
1148     // has already been reported eralier.
1149     if (!Category)
1150       return nullptr;
1151     // Look for this property declaration in @implementation's category
1152     property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
1153     if (!property) {
1154       Diag(PropertyLoc, diag::err_bad_category_property_decl)
1155       << Category->getDeclName();
1156       return nullptr;
1157     }
1158   } else {
1159     Diag(AtLoc, diag::err_bad_property_context);
1160     return nullptr;
1161   }
1162   ObjCIvarDecl *Ivar = nullptr;
1163   bool CompleteTypeErr = false;
1164   bool compat = true;
1165   // Check that we have a valid, previously declared ivar for @synthesize
1166   if (Synthesize) {
1167     // @synthesize
1168     if (!PropertyIvar)
1169       PropertyIvar = PropertyId;
1170     // Check that this is a previously declared 'ivar' in 'IDecl' interface
1171     ObjCInterfaceDecl *ClassDeclared;
1172     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
1173     QualType PropType = property->getType();
1174     QualType PropertyIvarType = PropType.getNonReferenceType();
1175
1176     if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
1177                             diag::err_incomplete_synthesized_property,
1178                             property->getDeclName())) {
1179       Diag(property->getLocation(), diag::note_property_declare);
1180       CompleteTypeErr = true;
1181     }
1182
1183     if (getLangOpts().ObjCAutoRefCount &&
1184         (property->getPropertyAttributesAsWritten() &
1185          ObjCPropertyDecl::OBJC_PR_readonly) &&
1186         PropertyIvarType->isObjCRetainableType()) {
1187       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
1188     }
1189
1190     ObjCPropertyDecl::PropertyAttributeKind kind
1191       = property->getPropertyAttributes();
1192
1193     bool isARCWeak = false;
1194     if (kind & ObjCPropertyDecl::OBJC_PR_weak) {
1195       // Add GC __weak to the ivar type if the property is weak.
1196       if (getLangOpts().getGC() != LangOptions::NonGC) {
1197         assert(!getLangOpts().ObjCAutoRefCount);
1198         if (PropertyIvarType.isObjCGCStrong()) {
1199           Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
1200           Diag(property->getLocation(), diag::note_property_declare);
1201         } else {
1202           PropertyIvarType =
1203             Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
1204         }
1205
1206       // Otherwise, check whether ARC __weak is enabled and works with
1207       // the property type.
1208       } else {
1209         if (!getLangOpts().ObjCWeak) {
1210           // Only complain here when synthesizing an ivar.
1211           if (!Ivar) {
1212             Diag(PropertyDiagLoc,
1213                  getLangOpts().ObjCWeakRuntime
1214                    ? diag::err_synthesizing_arc_weak_property_disabled
1215                    : diag::err_synthesizing_arc_weak_property_no_runtime);
1216             Diag(property->getLocation(), diag::note_property_declare);
1217           }
1218           CompleteTypeErr = true; // suppress later diagnostics about the ivar
1219         } else {
1220           isARCWeak = true;
1221           if (const ObjCObjectPointerType *ObjT =
1222                 PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1223             const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1224             if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1225               Diag(property->getLocation(),
1226                    diag::err_arc_weak_unavailable_property)
1227                 << PropertyIvarType;
1228               Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1229                 << ClassImpDecl->getName();
1230             }
1231           }
1232         }
1233       }
1234     }
1235
1236     if (AtLoc.isInvalid()) {
1237       // Check when default synthesizing a property that there is
1238       // an ivar matching property name and issue warning; since this
1239       // is the most common case of not using an ivar used for backing
1240       // property in non-default synthesis case.
1241       ObjCInterfaceDecl *ClassDeclared=nullptr;
1242       ObjCIvarDecl *originalIvar =
1243       IDecl->lookupInstanceVariable(property->getIdentifier(),
1244                                     ClassDeclared);
1245       if (originalIvar) {
1246         Diag(PropertyDiagLoc,
1247              diag::warn_autosynthesis_property_ivar_match)
1248         << PropertyId << (Ivar == nullptr) << PropertyIvar
1249         << originalIvar->getIdentifier();
1250         Diag(property->getLocation(), diag::note_property_declare);
1251         Diag(originalIvar->getLocation(), diag::note_ivar_decl);
1252       }
1253     }
1254
1255     if (!Ivar) {
1256       // In ARC, give the ivar a lifetime qualifier based on the
1257       // property attributes.
1258       if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
1259           !PropertyIvarType.getObjCLifetime() &&
1260           PropertyIvarType->isObjCRetainableType()) {
1261
1262         // It's an error if we have to do this and the user didn't
1263         // explicitly write an ownership attribute on the property.
1264         if (!hasWrittenStorageAttribute(property, QueryKind) &&
1265             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
1266           Diag(PropertyDiagLoc,
1267                diag::err_arc_objc_property_default_assign_on_object);
1268           Diag(property->getLocation(), diag::note_property_declare);
1269         } else {
1270           Qualifiers::ObjCLifetime lifetime =
1271             getImpliedARCOwnership(kind, PropertyIvarType);
1272           assert(lifetime && "no lifetime for property?");
1273
1274           Qualifiers qs;
1275           qs.addObjCLifetime(lifetime);
1276           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1277         }
1278       }
1279
1280       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1281                                   PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1282                                   PropertyIvarType, /*Dinfo=*/nullptr,
1283                                   ObjCIvarDecl::Private,
1284                                   (Expr *)nullptr, true);
1285       if (RequireNonAbstractType(PropertyIvarLoc,
1286                                  PropertyIvarType,
1287                                  diag::err_abstract_type_in_decl,
1288                                  AbstractSynthesizedIvarType)) {
1289         Diag(property->getLocation(), diag::note_property_declare);
1290         // An abstract type is as bad as an incomplete type.
1291         CompleteTypeErr = true;
1292       }
1293       if (CompleteTypeErr)
1294         Ivar->setInvalidDecl();
1295       ClassImpDecl->addDecl(Ivar);
1296       IDecl->makeDeclVisibleInContext(Ivar);
1297
1298       if (getLangOpts().ObjCRuntime.isFragile())
1299         Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
1300             << PropertyId;
1301       // Note! I deliberately want it to fall thru so, we have a
1302       // a property implementation and to avoid future warnings.
1303     } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1304                !declaresSameEntity(ClassDeclared, IDecl)) {
1305       Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
1306       << property->getDeclName() << Ivar->getDeclName()
1307       << ClassDeclared->getDeclName();
1308       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1309       << Ivar << Ivar->getName();
1310       // Note! I deliberately want it to fall thru so more errors are caught.
1311     }
1312     property->setPropertyIvarDecl(Ivar);
1313
1314     QualType IvarType = Context.getCanonicalType(Ivar->getType());
1315
1316     // Check that type of property and its ivar are type compatible.
1317     if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1318       if (isa<ObjCObjectPointerType>(PropertyIvarType)
1319           && isa<ObjCObjectPointerType>(IvarType))
1320         compat =
1321           Context.canAssignObjCInterfaces(
1322                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
1323                                   IvarType->getAs<ObjCObjectPointerType>());
1324       else {
1325         compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1326                                              IvarType)
1327                     == Compatible);
1328       }
1329       if (!compat) {
1330         Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1331           << property->getDeclName() << PropType
1332           << Ivar->getDeclName() << IvarType;
1333         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1334         // Note! I deliberately want it to fall thru so, we have a
1335         // a property implementation and to avoid future warnings.
1336       }
1337       else {
1338         // FIXME! Rules for properties are somewhat different that those
1339         // for assignments. Use a new routine to consolidate all cases;
1340         // specifically for property redeclarations as well as for ivars.
1341         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1342         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1343         if (lhsType != rhsType &&
1344             lhsType->isArithmeticType()) {
1345           Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1346             << property->getDeclName() << PropType
1347             << Ivar->getDeclName() << IvarType;
1348           Diag(Ivar->getLocation(), diag::note_ivar_decl);
1349           // Fall thru - see previous comment
1350         }
1351       }
1352       // __weak is explicit. So it works on Canonical type.
1353       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1354            getLangOpts().getGC() != LangOptions::NonGC)) {
1355         Diag(PropertyDiagLoc, diag::err_weak_property)
1356         << property->getDeclName() << Ivar->getDeclName();
1357         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1358         // Fall thru - see previous comment
1359       }
1360       // Fall thru - see previous comment
1361       if ((property->getType()->isObjCObjectPointerType() ||
1362            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1363           getLangOpts().getGC() != LangOptions::NonGC) {
1364         Diag(PropertyDiagLoc, diag::err_strong_property)
1365         << property->getDeclName() << Ivar->getDeclName();
1366         // Fall thru - see previous comment
1367       }
1368     }
1369     if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1370         Ivar->getType().getObjCLifetime())
1371       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1372   } else if (PropertyIvar)
1373     // @dynamic
1374     Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
1375
1376   assert (property && "ActOnPropertyImplDecl - property declaration missing");
1377   ObjCPropertyImplDecl *PIDecl =
1378   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1379                                property,
1380                                (Synthesize ?
1381                                 ObjCPropertyImplDecl::Synthesize
1382                                 : ObjCPropertyImplDecl::Dynamic),
1383                                Ivar, PropertyIvarLoc);
1384
1385   if (CompleteTypeErr || !compat)
1386     PIDecl->setInvalidDecl();
1387
1388   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1389     getterMethod->createImplicitParams(Context, IDecl);
1390     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1391         Ivar->getType()->isRecordType()) {
1392       // For Objective-C++, need to synthesize the AST for the IVAR object to be
1393       // returned by the getter as it must conform to C++'s copy-return rules.
1394       // FIXME. Eventually we want to do this for Objective-C as well.
1395       SynthesizedFunctionScope Scope(*this, getterMethod);
1396       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1397       DeclRefExpr *SelfExpr =
1398         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1399                                   VK_LValue, PropertyDiagLoc);
1400       MarkDeclRefReferenced(SelfExpr);
1401       Expr *LoadSelfExpr =
1402         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1403                                  CK_LValueToRValue, SelfExpr, nullptr,
1404                                  VK_RValue);
1405       Expr *IvarRefExpr =
1406         new (Context) ObjCIvarRefExpr(Ivar,
1407                                       Ivar->getUsageType(SelfDecl->getType()),
1408                                       PropertyDiagLoc,
1409                                       Ivar->getLocation(),
1410                                       LoadSelfExpr, true, true);
1411       ExprResult Res = PerformCopyInitialization(
1412           InitializedEntity::InitializeResult(PropertyDiagLoc,
1413                                               getterMethod->getReturnType(),
1414                                               /*NRVO=*/false),
1415           PropertyDiagLoc, IvarRefExpr);
1416       if (!Res.isInvalid()) {
1417         Expr *ResExpr = Res.getAs<Expr>();
1418         if (ResExpr)
1419           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1420         PIDecl->setGetterCXXConstructor(ResExpr);
1421       }
1422     }
1423     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1424         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1425       Diag(getterMethod->getLocation(),
1426            diag::warn_property_getter_owning_mismatch);
1427       Diag(property->getLocation(), diag::note_property_declare);
1428     }
1429     if (getLangOpts().ObjCAutoRefCount && Synthesize)
1430       switch (getterMethod->getMethodFamily()) {
1431         case OMF_retain:
1432         case OMF_retainCount:
1433         case OMF_release:
1434         case OMF_autorelease:
1435           Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1436             << 1 << getterMethod->getSelector();
1437           break;
1438         default:
1439           break;
1440       }
1441   }
1442   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1443     setterMethod->createImplicitParams(Context, IDecl);
1444     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1445         Ivar->getType()->isRecordType()) {
1446       // FIXME. Eventually we want to do this for Objective-C as well.
1447       SynthesizedFunctionScope Scope(*this, setterMethod);
1448       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1449       DeclRefExpr *SelfExpr =
1450         new (Context) DeclRefExpr(SelfDecl, false, SelfDecl->getType(),
1451                                   VK_LValue, PropertyDiagLoc);
1452       MarkDeclRefReferenced(SelfExpr);
1453       Expr *LoadSelfExpr =
1454         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1455                                  CK_LValueToRValue, SelfExpr, nullptr,
1456                                  VK_RValue);
1457       Expr *lhs =
1458         new (Context) ObjCIvarRefExpr(Ivar,
1459                                       Ivar->getUsageType(SelfDecl->getType()),
1460                                       PropertyDiagLoc,
1461                                       Ivar->getLocation(),
1462                                       LoadSelfExpr, true, true);
1463       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1464       ParmVarDecl *Param = (*P);
1465       QualType T = Param->getType().getNonReferenceType();
1466       DeclRefExpr *rhs = new (Context) DeclRefExpr(Param, false, T,
1467                                                    VK_LValue, PropertyDiagLoc);
1468       MarkDeclRefReferenced(rhs);
1469       ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1470                                   BO_Assign, lhs, rhs);
1471       if (property->getPropertyAttributes() &
1472           ObjCPropertyDecl::OBJC_PR_atomic) {
1473         Expr *callExpr = Res.getAs<Expr>();
1474         if (const CXXOperatorCallExpr *CXXCE =
1475               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1476           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1477             if (!FuncDecl->isTrivial())
1478               if (property->getType()->isReferenceType()) {
1479                 Diag(PropertyDiagLoc,
1480                      diag::err_atomic_property_nontrivial_assign_op)
1481                     << property->getType();
1482                 Diag(FuncDecl->getLocStart(),
1483                      diag::note_callee_decl) << FuncDecl;
1484               }
1485       }
1486       PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1487     }
1488   }
1489
1490   if (IC) {
1491     if (Synthesize)
1492       if (ObjCPropertyImplDecl *PPIDecl =
1493           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1494         Diag(PropertyLoc, diag::err_duplicate_ivar_use)
1495         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1496         << PropertyIvar;
1497         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1498       }
1499
1500     if (ObjCPropertyImplDecl *PPIDecl
1501         = IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
1502       Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
1503       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1504       return nullptr;
1505     }
1506     IC->addPropertyImplementation(PIDecl);
1507     if (getLangOpts().ObjCDefaultSynthProperties &&
1508         getLangOpts().ObjCRuntime.isNonFragile() &&
1509         !IDecl->isObjCRequiresPropertyDefs()) {
1510       // Diagnose if an ivar was lazily synthesdized due to a previous
1511       // use and if 1) property is @dynamic or 2) property is synthesized
1512       // but it requires an ivar of different name.
1513       ObjCInterfaceDecl *ClassDeclared=nullptr;
1514       ObjCIvarDecl *Ivar = nullptr;
1515       if (!Synthesize)
1516         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1517       else {
1518         if (PropertyIvar && PropertyIvar != PropertyId)
1519           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1520       }
1521       // Issue diagnostics only if Ivar belongs to current class.
1522       if (Ivar && Ivar->getSynthesize() &&
1523           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1524         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1525         << PropertyId;
1526         Ivar->setInvalidDecl();
1527       }
1528     }
1529   } else {
1530     if (Synthesize)
1531       if (ObjCPropertyImplDecl *PPIDecl =
1532           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1533         Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
1534         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1535         << PropertyIvar;
1536         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1537       }
1538
1539     if (ObjCPropertyImplDecl *PPIDecl =
1540         CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
1541       Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
1542       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1543       return nullptr;
1544     }
1545     CatImplClass->addPropertyImplementation(PIDecl);
1546   }
1547
1548   return PIDecl;
1549 }
1550
1551 //===----------------------------------------------------------------------===//
1552 // Helper methods.
1553 //===----------------------------------------------------------------------===//
1554
1555 /// DiagnosePropertyMismatch - Compares two properties for their
1556 /// attributes and types and warns on a variety of inconsistencies.
1557 ///
1558 void
1559 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1560                                ObjCPropertyDecl *SuperProperty,
1561                                const IdentifierInfo *inheritedName,
1562                                bool OverridingProtocolProperty) {
1563   ObjCPropertyDecl::PropertyAttributeKind CAttr =
1564     Property->getPropertyAttributes();
1565   ObjCPropertyDecl::PropertyAttributeKind SAttr =
1566     SuperProperty->getPropertyAttributes();
1567
1568   // We allow readonly properties without an explicit ownership
1569   // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1570   // to be overridden by a property with any explicit ownership in the subclass.
1571   if (!OverridingProtocolProperty &&
1572       !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1573     ;
1574   else {
1575     if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
1576         && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
1577       Diag(Property->getLocation(), diag::warn_readonly_property)
1578         << Property->getDeclName() << inheritedName;
1579     if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
1580         != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
1581       Diag(Property->getLocation(), diag::warn_property_attribute)
1582         << Property->getDeclName() << "copy" << inheritedName;
1583     else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
1584       unsigned CAttrRetain =
1585         (CAttr &
1586          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1587       unsigned SAttrRetain =
1588         (SAttr &
1589          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1590       bool CStrong = (CAttrRetain != 0);
1591       bool SStrong = (SAttrRetain != 0);
1592       if (CStrong != SStrong)
1593         Diag(Property->getLocation(), diag::warn_property_attribute)
1594           << Property->getDeclName() << "retain (or strong)" << inheritedName;
1595     }
1596   }
1597
1598   // Check for nonatomic; note that nonatomic is effectively
1599   // meaningless for readonly properties, so don't diagnose if the
1600   // atomic property is 'readonly'.
1601   checkAtomicPropertyMismatch(*this, SuperProperty, Property, false);
1602   if (Property->getSetterName() != SuperProperty->getSetterName()) {
1603     Diag(Property->getLocation(), diag::warn_property_attribute)
1604       << Property->getDeclName() << "setter" << inheritedName;
1605     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1606   }
1607   if (Property->getGetterName() != SuperProperty->getGetterName()) {
1608     Diag(Property->getLocation(), diag::warn_property_attribute)
1609       << Property->getDeclName() << "getter" << inheritedName;
1610     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1611   }
1612
1613   QualType LHSType =
1614     Context.getCanonicalType(SuperProperty->getType());
1615   QualType RHSType =
1616     Context.getCanonicalType(Property->getType());
1617
1618   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1619     // Do cases not handled in above.
1620     // FIXME. For future support of covariant property types, revisit this.
1621     bool IncompatibleObjC = false;
1622     QualType ConvertedType;
1623     if (!isObjCPointerConversion(RHSType, LHSType,
1624                                  ConvertedType, IncompatibleObjC) ||
1625         IncompatibleObjC) {
1626         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1627         << Property->getType() << SuperProperty->getType() << inheritedName;
1628       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1629     }
1630   }
1631 }
1632
1633 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1634                                             ObjCMethodDecl *GetterMethod,
1635                                             SourceLocation Loc) {
1636   if (!GetterMethod)
1637     return false;
1638   QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1639   QualType PropertyRValueType =
1640       property->getType().getNonReferenceType().getAtomicUnqualifiedType();
1641   bool compat = Context.hasSameType(PropertyRValueType, GetterType);
1642   if (!compat) {
1643     const ObjCObjectPointerType *propertyObjCPtr = nullptr;
1644     const ObjCObjectPointerType *getterObjCPtr = nullptr;
1645     if ((propertyObjCPtr =
1646              PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
1647         (getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
1648       compat = Context.canAssignObjCInterfaces(getterObjCPtr, propertyObjCPtr);
1649     else if (CheckAssignmentConstraints(Loc, GetterType, PropertyRValueType)
1650               != Compatible) {
1651           Diag(Loc, diag::err_property_accessor_type)
1652             << property->getDeclName() << PropertyRValueType
1653             << GetterMethod->getSelector() << GetterType;
1654           Diag(GetterMethod->getLocation(), diag::note_declared_at);
1655           return true;
1656     } else {
1657       compat = true;
1658       QualType lhsType = Context.getCanonicalType(PropertyRValueType);
1659       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1660       if (lhsType != rhsType && lhsType->isArithmeticType())
1661         compat = false;
1662     }
1663   }
1664
1665   if (!compat) {
1666     Diag(Loc, diag::warn_accessor_property_type_mismatch)
1667     << property->getDeclName()
1668     << GetterMethod->getSelector();
1669     Diag(GetterMethod->getLocation(), diag::note_declared_at);
1670     return true;
1671   }
1672
1673   return false;
1674 }
1675
1676 /// CollectImmediateProperties - This routine collects all properties in
1677 /// the class and its conforming protocols; but not those in its super class.
1678 static void
1679 CollectImmediateProperties(ObjCContainerDecl *CDecl,
1680                            ObjCContainerDecl::PropertyMap &PropMap,
1681                            ObjCContainerDecl::PropertyMap &SuperPropMap,
1682                            bool CollectClassPropsOnly = false,
1683                            bool IncludeProtocols = true) {
1684   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1685     for (auto *Prop : IDecl->properties()) {
1686       if (CollectClassPropsOnly && !Prop->isClassProperty())
1687         continue;
1688       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1689           Prop;
1690     }
1691
1692     // Collect the properties from visible extensions.
1693     for (auto *Ext : IDecl->visible_extensions())
1694       CollectImmediateProperties(Ext, PropMap, SuperPropMap,
1695                                  CollectClassPropsOnly, IncludeProtocols);
1696
1697     if (IncludeProtocols) {
1698       // Scan through class's protocols.
1699       for (auto *PI : IDecl->all_referenced_protocols())
1700         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1701                                    CollectClassPropsOnly);
1702     }
1703   }
1704   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1705     for (auto *Prop : CATDecl->properties()) {
1706       if (CollectClassPropsOnly && !Prop->isClassProperty())
1707         continue;
1708       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1709           Prop;
1710     }
1711     if (IncludeProtocols) {
1712       // Scan through class's protocols.
1713       for (auto *PI : CATDecl->protocols())
1714         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1715                                    CollectClassPropsOnly);
1716     }
1717   }
1718   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1719     for (auto *Prop : PDecl->properties()) {
1720       if (CollectClassPropsOnly && !Prop->isClassProperty())
1721         continue;
1722       ObjCPropertyDecl *PropertyFromSuper =
1723           SuperPropMap[std::make_pair(Prop->getIdentifier(),
1724                                       Prop->isClassProperty())];
1725       // Exclude property for protocols which conform to class's super-class,
1726       // as super-class has to implement the property.
1727       if (!PropertyFromSuper ||
1728           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1729         ObjCPropertyDecl *&PropEntry =
1730             PropMap[std::make_pair(Prop->getIdentifier(),
1731                                    Prop->isClassProperty())];
1732         if (!PropEntry)
1733           PropEntry = Prop;
1734       }
1735     }
1736     // Scan through protocol's protocols.
1737     for (auto *PI : PDecl->protocols())
1738       CollectImmediateProperties(PI, PropMap, SuperPropMap,
1739                                  CollectClassPropsOnly);
1740   }
1741 }
1742
1743 /// CollectSuperClassPropertyImplementations - This routine collects list of
1744 /// properties to be implemented in super class(s) and also coming from their
1745 /// conforming protocols.
1746 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1747                                     ObjCInterfaceDecl::PropertyMap &PropMap) {
1748   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1749     ObjCInterfaceDecl::PropertyDeclOrder PO;
1750     while (SDecl) {
1751       SDecl->collectPropertiesToImplement(PropMap, PO);
1752       SDecl = SDecl->getSuperClass();
1753     }
1754   }
1755 }
1756
1757 /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1758 /// an ivar synthesized for 'Method' and 'Method' is a property accessor
1759 /// declared in class 'IFace'.
1760 bool
1761 Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1762                                      ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1763   if (!IV->getSynthesize())
1764     return false;
1765   ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1766                                             Method->isInstanceMethod());
1767   if (!IMD || !IMD->isPropertyAccessor())
1768     return false;
1769
1770   // look up a property declaration whose one of its accessors is implemented
1771   // by this method.
1772   for (const auto *Property : IFace->instance_properties()) {
1773     if ((Property->getGetterName() == IMD->getSelector() ||
1774          Property->getSetterName() == IMD->getSelector()) &&
1775         (Property->getPropertyIvarDecl() == IV))
1776       return true;
1777   }
1778   // Also look up property declaration in class extension whose one of its
1779   // accessors is implemented by this method.
1780   for (const auto *Ext : IFace->known_extensions())
1781     for (const auto *Property : Ext->instance_properties())
1782       if ((Property->getGetterName() == IMD->getSelector() ||
1783            Property->getSetterName() == IMD->getSelector()) &&
1784           (Property->getPropertyIvarDecl() == IV))
1785         return true;
1786   return false;
1787 }
1788
1789 static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1790                                          ObjCPropertyDecl *Prop) {
1791   bool SuperClassImplementsGetter = false;
1792   bool SuperClassImplementsSetter = false;
1793   if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1794     SuperClassImplementsSetter = true;
1795
1796   while (IDecl->getSuperClass()) {
1797     ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1798     if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1799       SuperClassImplementsGetter = true;
1800
1801     if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1802       SuperClassImplementsSetter = true;
1803     if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1804       return true;
1805     IDecl = IDecl->getSuperClass();
1806   }
1807   return false;
1808 }
1809
1810 /// \brief Default synthesizes all properties which must be synthesized
1811 /// in class's \@implementation.
1812 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
1813                                        ObjCInterfaceDecl *IDecl,
1814                                        SourceLocation AtEnd) {
1815   ObjCInterfaceDecl::PropertyMap PropMap;
1816   ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
1817   IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
1818   if (PropMap.empty())
1819     return;
1820   ObjCInterfaceDecl::PropertyMap SuperPropMap;
1821   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1822
1823   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
1824     ObjCPropertyDecl *Prop = PropertyOrder[i];
1825     // Is there a matching property synthesize/dynamic?
1826     if (Prop->isInvalidDecl() ||
1827         Prop->isClassProperty() ||
1828         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1829       continue;
1830     // Property may have been synthesized by user.
1831     if (IMPDecl->FindPropertyImplDecl(
1832             Prop->getIdentifier(), Prop->getQueryKind()))
1833       continue;
1834     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1835       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1836         continue;
1837       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1838         continue;
1839     }
1840     if (ObjCPropertyImplDecl *PID =
1841         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1842       Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1843         << Prop->getIdentifier();
1844       if (PID->getLocation().isValid())
1845         Diag(PID->getLocation(), diag::note_property_synthesize);
1846       continue;
1847     }
1848     ObjCPropertyDecl *PropInSuperClass =
1849         SuperPropMap[std::make_pair(Prop->getIdentifier(),
1850                                     Prop->isClassProperty())];
1851     if (ObjCProtocolDecl *Proto =
1852           dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1853       // We won't auto-synthesize properties declared in protocols.
1854       // Suppress the warning if class's superclass implements property's
1855       // getter and implements property's setter (if readwrite property).
1856       // Or, if property is going to be implemented in its super class.
1857       if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1858         Diag(IMPDecl->getLocation(),
1859              diag::warn_auto_synthesizing_protocol_property)
1860           << Prop << Proto;
1861         Diag(Prop->getLocation(), diag::note_property_declare);
1862         std::string FixIt =
1863             (Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
1864         Diag(AtEnd, diag::note_add_synthesize_directive)
1865             << FixItHint::CreateInsertion(AtEnd, FixIt);
1866       }
1867       continue;
1868     }
1869     // If property to be implemented in the super class, ignore.
1870     if (PropInSuperClass) {
1871       if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
1872           (PropInSuperClass->getPropertyAttributes() &
1873            ObjCPropertyDecl::OBJC_PR_readonly) &&
1874           !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1875           !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1876         Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1877         << Prop->getIdentifier();
1878         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1879       }
1880       else {
1881         Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1882         << Prop->getIdentifier();
1883         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1884         Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1885       }
1886       continue;
1887     }
1888     // We use invalid SourceLocations for the synthesized ivars since they
1889     // aren't really synthesized at a particular location; they just exist.
1890     // Saying that they are located at the @implementation isn't really going
1891     // to help users.
1892     ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1893       ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1894                             true,
1895                             /* property = */ Prop->getIdentifier(),
1896                             /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1897                             Prop->getLocation(), Prop->getQueryKind()));
1898     if (PIDecl) {
1899       Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1900       Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1901     }
1902   }
1903 }
1904
1905 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
1906                                        SourceLocation AtEnd) {
1907   if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1908     return;
1909   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1910   if (!IC)
1911     return;
1912   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1913     if (!IDecl->isObjCRequiresPropertyDefs())
1914       DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
1915 }
1916
1917 static void DiagnoseUnimplementedAccessor(
1918     Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
1919     ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
1920     ObjCPropertyDecl *Prop,
1921     llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
1922   // Check to see if we have a corresponding selector in SMap and with the
1923   // right method type.
1924   auto I = std::find_if(SMap.begin(), SMap.end(),
1925     [&](const ObjCMethodDecl *x) {
1926       return x->getSelector() == Method &&
1927              x->isClassMethod() == Prop->isClassProperty();
1928     });
1929   // When reporting on missing property setter/getter implementation in
1930   // categories, do not report when they are declared in primary class,
1931   // class's protocol, or one of it super classes. This is because,
1932   // the class is going to implement them.
1933   if (I == SMap.end() &&
1934       (PrimaryClass == nullptr ||
1935        !PrimaryClass->lookupPropertyAccessor(Method, C,
1936                                              Prop->isClassProperty()))) {
1937     unsigned diag =
1938         isa<ObjCCategoryDecl>(CDecl)
1939             ? (Prop->isClassProperty()
1940                    ? diag::warn_impl_required_in_category_for_class_property
1941                    : diag::warn_setter_getter_impl_required_in_category)
1942             : (Prop->isClassProperty()
1943                    ? diag::warn_impl_required_for_class_property
1944                    : diag::warn_setter_getter_impl_required);
1945     S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
1946     S.Diag(Prop->getLocation(), diag::note_property_declare);
1947     if (S.LangOpts.ObjCDefaultSynthProperties &&
1948         S.LangOpts.ObjCRuntime.isNonFragile())
1949       if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1950         if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1951           S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1952   }
1953 }
1954
1955 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1956                                            ObjCContainerDecl *CDecl,
1957                                            bool SynthesizeProperties) {
1958   ObjCContainerDecl::PropertyMap PropMap;
1959   ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
1960
1961   // Since we don't synthesize class properties, we should emit diagnose even
1962   // if SynthesizeProperties is true.
1963   ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1964   // Gather properties which need not be implemented in this class
1965   // or category.
1966   if (!IDecl)
1967     if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1968       // For categories, no need to implement properties declared in
1969       // its primary class (and its super classes) if property is
1970       // declared in one of those containers.
1971       if ((IDecl = C->getClassInterface())) {
1972         ObjCInterfaceDecl::PropertyDeclOrder PO;
1973         IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
1974       }
1975     }
1976   if (IDecl)
1977     CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
1978
1979   // When SynthesizeProperties is true, we only check class properties.
1980   CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap,
1981                              SynthesizeProperties/*CollectClassPropsOnly*/);
1982
1983   // Scan the @interface to see if any of the protocols it adopts
1984   // require an explicit implementation, via attribute
1985   // 'objc_protocol_requires_explicit_implementation'.
1986   if (IDecl) {
1987     std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
1988
1989     for (auto *PDecl : IDecl->all_referenced_protocols()) {
1990       if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
1991         continue;
1992       // Lazily construct a set of all the properties in the @interface
1993       // of the class, without looking at the superclass.  We cannot
1994       // use the call to CollectImmediateProperties() above as that
1995       // utilizes information from the super class's properties as well
1996       // as scans the adopted protocols.  This work only triggers for protocols
1997       // with the attribute, which is very rare, and only occurs when
1998       // analyzing the @implementation.
1999       if (!LazyMap) {
2000         ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2001         LazyMap.reset(new ObjCContainerDecl::PropertyMap());
2002         CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
2003                                    /* CollectClassPropsOnly */ false,
2004                                    /* IncludeProtocols */ false);
2005       }
2006       // Add the properties of 'PDecl' to the list of properties that
2007       // need to be implemented.
2008       for (auto *PropDecl : PDecl->properties()) {
2009         if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
2010                                       PropDecl->isClassProperty())])
2011           continue;
2012         PropMap[std::make_pair(PropDecl->getIdentifier(),
2013                                PropDecl->isClassProperty())] = PropDecl;
2014       }
2015     }
2016   }
2017
2018   if (PropMap.empty())
2019     return;
2020
2021   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
2022   for (const auto *I : IMPDecl->property_impls())
2023     PropImplMap.insert(I->getPropertyDecl());
2024
2025   llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
2026   // Collect property accessors implemented in current implementation.
2027   for (const auto *I : IMPDecl->methods())
2028     InsMap.insert(I);
2029
2030   ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2031   ObjCInterfaceDecl *PrimaryClass = nullptr;
2032   if (C && !C->IsClassExtension())
2033     if ((PrimaryClass = C->getClassInterface()))
2034       // Report unimplemented properties in the category as well.
2035       if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
2036         // When reporting on missing setter/getters, do not report when
2037         // setter/getter is implemented in category's primary class
2038         // implementation.
2039         for (const auto *I : IMP->methods())
2040           InsMap.insert(I);
2041       }
2042
2043   for (ObjCContainerDecl::PropertyMap::iterator
2044        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
2045     ObjCPropertyDecl *Prop = P->second;
2046     // Is there a matching property synthesize/dynamic?
2047     if (Prop->isInvalidDecl() ||
2048         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
2049         PropImplMap.count(Prop) ||
2050         Prop->getAvailability() == AR_Unavailable)
2051       continue;
2052
2053     // Diagnose unimplemented getters and setters.
2054     DiagnoseUnimplementedAccessor(*this,
2055           PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
2056     if (!Prop->isReadOnly())
2057       DiagnoseUnimplementedAccessor(*this,
2058                                     PrimaryClass, Prop->getSetterName(),
2059                                     IMPDecl, CDecl, C, Prop, InsMap);
2060   }
2061 }
2062
2063 void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
2064   for (const auto *propertyImpl : impDecl->property_impls()) {
2065     const auto *property = propertyImpl->getPropertyDecl();
2066
2067     // Warn about null_resettable properties with synthesized setters,
2068     // because the setter won't properly handle nil.
2069     if (propertyImpl->getPropertyImplementation()
2070           == ObjCPropertyImplDecl::Synthesize &&
2071         (property->getPropertyAttributes() &
2072          ObjCPropertyDecl::OBJC_PR_null_resettable) &&
2073         property->getGetterMethodDecl() &&
2074         property->getSetterMethodDecl()) {
2075       auto *getterMethod = property->getGetterMethodDecl();
2076       auto *setterMethod = property->getSetterMethodDecl();
2077       if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
2078           !impDecl->getInstanceMethod(getterMethod->getSelector())) {
2079         SourceLocation loc = propertyImpl->getLocation();
2080         if (loc.isInvalid())
2081           loc = impDecl->getLocStart();
2082
2083         Diag(loc, diag::warn_null_resettable_setter)
2084           << setterMethod->getSelector() << property->getDeclName();
2085       }
2086     }
2087   }
2088 }
2089
2090 void
2091 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
2092                                        ObjCInterfaceDecl* IDecl) {
2093   // Rules apply in non-GC mode only
2094   if (getLangOpts().getGC() != LangOptions::NonGC)
2095     return;
2096   ObjCContainerDecl::PropertyMap PM;
2097   for (auto *Prop : IDecl->properties())
2098     PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2099   for (const auto *Ext : IDecl->known_extensions())
2100     for (auto *Prop : Ext->properties())
2101       PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2102
2103   for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
2104        I != E; ++I) {
2105     const ObjCPropertyDecl *Property = I->second;
2106     ObjCMethodDecl *GetterMethod = nullptr;
2107     ObjCMethodDecl *SetterMethod = nullptr;
2108     bool LookedUpGetterSetter = false;
2109
2110     unsigned Attributes = Property->getPropertyAttributes();
2111     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
2112
2113     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
2114         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
2115       GetterMethod = Property->isClassProperty() ?
2116                      IMPDecl->getClassMethod(Property->getGetterName()) :
2117                      IMPDecl->getInstanceMethod(Property->getGetterName());
2118       SetterMethod = Property->isClassProperty() ?
2119                      IMPDecl->getClassMethod(Property->getSetterName()) :
2120                      IMPDecl->getInstanceMethod(Property->getSetterName());
2121       LookedUpGetterSetter = true;
2122       if (GetterMethod) {
2123         Diag(GetterMethod->getLocation(),
2124              diag::warn_default_atomic_custom_getter_setter)
2125           << Property->getIdentifier() << 0;
2126         Diag(Property->getLocation(), diag::note_property_declare);
2127       }
2128       if (SetterMethod) {
2129         Diag(SetterMethod->getLocation(),
2130              diag::warn_default_atomic_custom_getter_setter)
2131           << Property->getIdentifier() << 1;
2132         Diag(Property->getLocation(), diag::note_property_declare);
2133       }
2134     }
2135
2136     // We only care about readwrite atomic property.
2137     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
2138         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
2139       continue;
2140     if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
2141             Property->getIdentifier(), Property->getQueryKind())) {
2142       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
2143         continue;
2144       if (!LookedUpGetterSetter) {
2145         GetterMethod = Property->isClassProperty() ?
2146                        IMPDecl->getClassMethod(Property->getGetterName()) :
2147                        IMPDecl->getInstanceMethod(Property->getGetterName());
2148         SetterMethod = Property->isClassProperty() ?
2149                        IMPDecl->getClassMethod(Property->getSetterName()) :
2150                        IMPDecl->getInstanceMethod(Property->getSetterName());
2151       }
2152       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
2153         SourceLocation MethodLoc =
2154           (GetterMethod ? GetterMethod->getLocation()
2155                         : SetterMethod->getLocation());
2156         Diag(MethodLoc, diag::warn_atomic_property_rule)
2157           << Property->getIdentifier() << (GetterMethod != nullptr)
2158           << (SetterMethod != nullptr);
2159         // fixit stuff.
2160         if (Property->getLParenLoc().isValid() &&
2161             !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
2162           // @property () ... case.
2163           SourceLocation AfterLParen =
2164             getLocForEndOfToken(Property->getLParenLoc());
2165           StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
2166                                                       : "nonatomic";
2167           Diag(Property->getLocation(),
2168                diag::note_atomic_property_fixup_suggest)
2169             << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
2170         } else if (Property->getLParenLoc().isInvalid()) {
2171           //@property id etc.
2172           SourceLocation startLoc =
2173             Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
2174           Diag(Property->getLocation(),
2175                diag::note_atomic_property_fixup_suggest)
2176             << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
2177         }
2178         else
2179           Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
2180         Diag(Property->getLocation(), diag::note_property_declare);
2181       }
2182     }
2183   }
2184 }
2185
2186 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
2187   if (getLangOpts().getGC() == LangOptions::GCOnly)
2188     return;
2189
2190   for (const auto *PID : D->property_impls()) {
2191     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
2192     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
2193         !PD->isClassProperty() &&
2194         !D->getInstanceMethod(PD->getGetterName())) {
2195       ObjCMethodDecl *method = PD->getGetterMethodDecl();
2196       if (!method)
2197         continue;
2198       ObjCMethodFamily family = method->getMethodFamily();
2199       if (family == OMF_alloc || family == OMF_copy ||
2200           family == OMF_mutableCopy || family == OMF_new) {
2201         if (getLangOpts().ObjCAutoRefCount)
2202           Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
2203         else
2204           Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
2205
2206         // Look for a getter explicitly declared alongside the property.
2207         // If we find one, use its location for the note.
2208         SourceLocation noteLoc = PD->getLocation();
2209         SourceLocation fixItLoc;
2210         for (auto *getterRedecl : method->redecls()) {
2211           if (getterRedecl->isImplicit())
2212             continue;
2213           if (getterRedecl->getDeclContext() != PD->getDeclContext())
2214             continue;
2215           noteLoc = getterRedecl->getLocation();
2216           fixItLoc = getterRedecl->getLocEnd();
2217         }
2218
2219         Preprocessor &PP = getPreprocessor();
2220         TokenValue tokens[] = {
2221           tok::kw___attribute, tok::l_paren, tok::l_paren,
2222           PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
2223           PP.getIdentifierInfo("none"), tok::r_paren,
2224           tok::r_paren, tok::r_paren
2225         };
2226         StringRef spelling = "__attribute__((objc_method_family(none)))";
2227         StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
2228         if (!macroName.empty())
2229           spelling = macroName;
2230
2231         auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
2232             << method->getDeclName() << spelling;
2233         if (fixItLoc.isValid()) {
2234           SmallString<64> fixItText(" ");
2235           fixItText += spelling;
2236           noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
2237         }
2238       }
2239     }
2240   }
2241 }
2242
2243 void Sema::DiagnoseMissingDesignatedInitOverrides(
2244                                             const ObjCImplementationDecl *ImplD,
2245                                             const ObjCInterfaceDecl *IFD) {
2246   assert(IFD->hasDesignatedInitializers());
2247   const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
2248   if (!SuperD)
2249     return;
2250
2251   SelectorSet InitSelSet;
2252   for (const auto *I : ImplD->instance_methods())
2253     if (I->getMethodFamily() == OMF_init)
2254       InitSelSet.insert(I->getSelector());
2255
2256   SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
2257   SuperD->getDesignatedInitializers(DesignatedInits);
2258   for (SmallVector<const ObjCMethodDecl *, 8>::iterator
2259          I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
2260     const ObjCMethodDecl *MD = *I;
2261     if (!InitSelSet.count(MD->getSelector())) {
2262       bool Ignore = false;
2263       if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
2264         Ignore = IMD->isUnavailable();
2265       }
2266       if (!Ignore) {
2267         Diag(ImplD->getLocation(),
2268              diag::warn_objc_implementation_missing_designated_init_override)
2269           << MD->getSelector();
2270         Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
2271       }
2272     }
2273   }
2274 }
2275
2276 /// AddPropertyAttrs - Propagates attributes from a property to the
2277 /// implicitly-declared getter or setter for that property.
2278 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
2279                              ObjCPropertyDecl *Property) {
2280   // Should we just clone all attributes over?
2281   for (const auto *A : Property->attrs()) {
2282     if (isa<DeprecatedAttr>(A) ||
2283         isa<UnavailableAttr>(A) ||
2284         isa<AvailabilityAttr>(A))
2285       PropertyMethod->addAttr(A->clone(S.Context));
2286   }
2287 }
2288
2289 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
2290 /// have the property type and issue diagnostics if they don't.
2291 /// Also synthesize a getter/setter method if none exist (and update the
2292 /// appropriate lookup tables.
2293 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
2294   ObjCMethodDecl *GetterMethod, *SetterMethod;
2295   ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
2296   if (CD->isInvalidDecl())
2297     return;
2298
2299   bool IsClassProperty = property->isClassProperty();
2300   GetterMethod = IsClassProperty ?
2301     CD->getClassMethod(property->getGetterName()) :
2302     CD->getInstanceMethod(property->getGetterName());
2303
2304   // if setter or getter is not found in class extension, it might be
2305   // in the primary class.
2306   if (!GetterMethod)
2307     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2308       if (CatDecl->IsClassExtension())
2309         GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2310                          getClassMethod(property->getGetterName()) :
2311                        CatDecl->getClassInterface()->
2312                          getInstanceMethod(property->getGetterName());
2313
2314   SetterMethod = IsClassProperty ?
2315                  CD->getClassMethod(property->getSetterName()) :
2316                  CD->getInstanceMethod(property->getSetterName());
2317   if (!SetterMethod)
2318     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2319       if (CatDecl->IsClassExtension())
2320         SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2321                           getClassMethod(property->getSetterName()) :
2322                        CatDecl->getClassInterface()->
2323                           getInstanceMethod(property->getSetterName());
2324   DiagnosePropertyAccessorMismatch(property, GetterMethod,
2325                                    property->getLocation());
2326
2327   if (!property->isReadOnly() && SetterMethod) {
2328     if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
2329         Context.VoidTy)
2330       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2331     if (SetterMethod->param_size() != 1 ||
2332         !Context.hasSameUnqualifiedType(
2333           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2334           property->getType().getNonReferenceType())) {
2335       Diag(property->getLocation(),
2336            diag::warn_accessor_property_type_mismatch)
2337         << property->getDeclName()
2338         << SetterMethod->getSelector();
2339       Diag(SetterMethod->getLocation(), diag::note_declared_at);
2340     }
2341   }
2342
2343   // Synthesize getter/setter methods if none exist.
2344   // Find the default getter and if one not found, add one.
2345   // FIXME: The synthesized property we set here is misleading. We almost always
2346   // synthesize these methods unless the user explicitly provided prototypes
2347   // (which is odd, but allowed). Sema should be typechecking that the
2348   // declarations jive in that situation (which it is not currently).
2349   if (!GetterMethod) {
2350     // No instance/class method of same name as property getter name was found.
2351     // Declare a getter method and add it to the list of methods
2352     // for this class.
2353     SourceLocation Loc = property->getLocation();
2354
2355     // The getter returns the declared property type with all qualifiers
2356     // removed.
2357     QualType resultTy = property->getType().getAtomicUnqualifiedType();
2358
2359     // If the property is null_resettable, the getter returns nonnull.
2360     if (property->getPropertyAttributes() &
2361         ObjCPropertyDecl::OBJC_PR_null_resettable) {
2362       QualType modifiedTy = resultTy;
2363       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
2364         if (*nullability == NullabilityKind::Unspecified)
2365           resultTy = Context.getAttributedType(AttributedType::attr_nonnull,
2366                                                modifiedTy, modifiedTy);
2367       }
2368     }
2369
2370     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
2371                              property->getGetterName(),
2372                              resultTy, nullptr, CD,
2373                              !IsClassProperty, /*isVariadic=*/false,
2374                              /*isPropertyAccessor=*/true,
2375                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2376                              (property->getPropertyImplementation() ==
2377                               ObjCPropertyDecl::Optional) ?
2378                              ObjCMethodDecl::Optional :
2379                              ObjCMethodDecl::Required);
2380     CD->addDecl(GetterMethod);
2381
2382     AddPropertyAttrs(*this, GetterMethod, property);
2383
2384     if (property->hasAttr<NSReturnsNotRetainedAttr>())
2385       GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2386                                                                      Loc));
2387
2388     if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2389       GetterMethod->addAttr(
2390         ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2391
2392     if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2393       GetterMethod->addAttr(
2394           SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2395                                       SA->getName(), Loc));
2396
2397     if (getLangOpts().ObjCAutoRefCount)
2398       CheckARCMethodDecl(GetterMethod);
2399   } else
2400     // A user declared getter will be synthesize when @synthesize of
2401     // the property with the same name is seen in the @implementation
2402     GetterMethod->setPropertyAccessor(true);
2403   property->setGetterMethodDecl(GetterMethod);
2404
2405   // Skip setter if property is read-only.
2406   if (!property->isReadOnly()) {
2407     // Find the default setter and if one not found, add one.
2408     if (!SetterMethod) {
2409       // No instance/class method of same name as property setter name was
2410       // found.
2411       // Declare a setter method and add it to the list of methods
2412       // for this class.
2413       SourceLocation Loc = property->getLocation();
2414
2415       SetterMethod =
2416         ObjCMethodDecl::Create(Context, Loc, Loc,
2417                                property->getSetterName(), Context.VoidTy,
2418                                nullptr, CD, !IsClassProperty,
2419                                /*isVariadic=*/false,
2420                                /*isPropertyAccessor=*/true,
2421                                /*isImplicitlyDeclared=*/true,
2422                                /*isDefined=*/false,
2423                                (property->getPropertyImplementation() ==
2424                                 ObjCPropertyDecl::Optional) ?
2425                                 ObjCMethodDecl::Optional :
2426                                 ObjCMethodDecl::Required);
2427
2428       // Remove all qualifiers from the setter's parameter type.
2429       QualType paramTy =
2430           property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
2431
2432       // If the property is null_resettable, the setter accepts a
2433       // nullable value.
2434       if (property->getPropertyAttributes() &
2435           ObjCPropertyDecl::OBJC_PR_null_resettable) {
2436         QualType modifiedTy = paramTy;
2437         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2438           if (*nullability == NullabilityKind::Unspecified)
2439             paramTy = Context.getAttributedType(AttributedType::attr_nullable,
2440                                                 modifiedTy, modifiedTy);
2441         }
2442       }
2443
2444       // Invent the arguments for the setter. We don't bother making a
2445       // nice name for the argument.
2446       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2447                                                   Loc, Loc,
2448                                                   property->getIdentifier(),
2449                                                   paramTy,
2450                                                   /*TInfo=*/nullptr,
2451                                                   SC_None,
2452                                                   nullptr);
2453       SetterMethod->setMethodParams(Context, Argument, None);
2454
2455       AddPropertyAttrs(*this, SetterMethod, property);
2456
2457       CD->addDecl(SetterMethod);
2458       if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2459         SetterMethod->addAttr(
2460             SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2461                                         SA->getName(), Loc));
2462       // It's possible for the user to have set a very odd custom
2463       // setter selector that causes it to have a method family.
2464       if (getLangOpts().ObjCAutoRefCount)
2465         CheckARCMethodDecl(SetterMethod);
2466     } else
2467       // A user declared setter will be synthesize when @synthesize of
2468       // the property with the same name is seen in the @implementation
2469       SetterMethod->setPropertyAccessor(true);
2470     property->setSetterMethodDecl(SetterMethod);
2471   }
2472   // Add any synthesized methods to the global pool. This allows us to
2473   // handle the following, which is supported by GCC (and part of the design).
2474   //
2475   // @interface Foo
2476   // @property double bar;
2477   // @end
2478   //
2479   // void thisIsUnfortunate() {
2480   //   id foo;
2481   //   double bar = [foo bar];
2482   // }
2483   //
2484   if (!IsClassProperty) {
2485     if (GetterMethod)
2486       AddInstanceMethodToGlobalPool(GetterMethod);
2487     if (SetterMethod)
2488       AddInstanceMethodToGlobalPool(SetterMethod);
2489   } else {
2490     if (GetterMethod)
2491       AddFactoryMethodToGlobalPool(GetterMethod);
2492     if (SetterMethod)
2493       AddFactoryMethodToGlobalPool(SetterMethod);
2494   }
2495
2496   ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2497   if (!CurrentClass) {
2498     if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2499       CurrentClass = Cat->getClassInterface();
2500     else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2501       CurrentClass = Impl->getClassInterface();
2502   }
2503   if (GetterMethod)
2504     CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2505   if (SetterMethod)
2506     CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2507 }
2508
2509 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2510                                        SourceLocation Loc,
2511                                        unsigned &Attributes,
2512                                        bool propertyInPrimaryClass) {
2513   // FIXME: Improve the reported location.
2514   if (!PDecl || PDecl->isInvalidDecl())
2515     return;
2516
2517   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2518       (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
2519     Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2520     << "readonly" << "readwrite";
2521
2522   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2523   QualType PropertyTy = PropertyDecl->getType();
2524
2525   // Check for copy or retain on non-object types.
2526   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
2527                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
2528       !PropertyTy->isObjCRetainableType() &&
2529       !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2530     Diag(Loc, diag::err_objc_property_requires_object)
2531       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
2532           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
2533     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
2534                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
2535     PropertyDecl->setInvalidDecl();
2536   }
2537
2538   // Check for more than one of { assign, copy, retain }.
2539   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
2540     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2541       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2542         << "assign" << "copy";
2543       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2544     }
2545     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2546       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2547         << "assign" << "retain";
2548       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2549     }
2550     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2551       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2552         << "assign" << "strong";
2553       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2554     }
2555     if (getLangOpts().ObjCAutoRefCount  &&
2556         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2557       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2558         << "assign" << "weak";
2559       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2560     }
2561     if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2562       Diag(Loc, diag::warn_iboutletcollection_property_assign);
2563   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
2564     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2565       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2566         << "unsafe_unretained" << "copy";
2567       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2568     }
2569     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2570       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2571         << "unsafe_unretained" << "retain";
2572       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2573     }
2574     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2575       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2576         << "unsafe_unretained" << "strong";
2577       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2578     }
2579     if (getLangOpts().ObjCAutoRefCount  &&
2580         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2581       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2582         << "unsafe_unretained" << "weak";
2583       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2584     }
2585   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2586     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2587       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2588         << "copy" << "retain";
2589       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2590     }
2591     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2592       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2593         << "copy" << "strong";
2594       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2595     }
2596     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2597       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2598         << "copy" << "weak";
2599       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2600     }
2601   }
2602   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2603            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2604       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2605         << "retain" << "weak";
2606       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2607   }
2608   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2609            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2610       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2611         << "strong" << "weak";
2612       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2613   }
2614
2615   if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2616     // 'weak' and 'nonnull' are mutually exclusive.
2617     if (auto nullability = PropertyTy->getNullability(Context)) {
2618       if (*nullability == NullabilityKind::NonNull)
2619         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2620           << "nonnull" << "weak";
2621     }
2622   }
2623
2624   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
2625       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
2626       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2627         << "atomic" << "nonatomic";
2628       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
2629   }
2630
2631   // Warn if user supplied no assignment attribute, property is
2632   // readwrite, and this is an object type.
2633   if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
2634     if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
2635       // do nothing
2636     } else if (getLangOpts().ObjCAutoRefCount) {
2637       // With arc, @property definitions should default to strong when
2638       // not specified.
2639       PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
2640     } else if (PropertyTy->isObjCObjectPointerType()) {
2641         bool isAnyClassTy =
2642           (PropertyTy->isObjCClassType() ||
2643            PropertyTy->isObjCQualifiedClassType());
2644         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2645         // issue any warning.
2646         if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2647           ;
2648         else if (propertyInPrimaryClass) {
2649           // Don't issue warning on property with no life time in class
2650           // extension as it is inherited from property in primary class.
2651           // Skip this warning in gc-only mode.
2652           if (getLangOpts().getGC() != LangOptions::GCOnly)
2653             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2654
2655           // If non-gc code warn that this is likely inappropriate.
2656           if (getLangOpts().getGC() == LangOptions::NonGC)
2657             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2658         }
2659     }
2660
2661     // FIXME: Implement warning dependent on NSCopying being
2662     // implemented. See also:
2663     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2664     // (please trim this list while you are at it).
2665   }
2666
2667   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
2668       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
2669       && getLangOpts().getGC() == LangOptions::GCOnly
2670       && PropertyTy->isBlockPointerType())
2671     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2672   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2673            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2674            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2675            PropertyTy->isBlockPointerType())
2676       Diag(Loc, diag::warn_objc_property_retain_of_block);
2677
2678   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2679       (Attributes & ObjCDeclSpec::DQ_PR_setter))
2680     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2681 }