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 /// 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().getEndLoc();
 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().getBeginLoc();
 618     TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
 619   }
 620
 621   DeclContext *DC = 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->getPropertyAttributesAsWritten();
 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->getPropertyAttributesAsWritten();
 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       // The ownership might be incompatible unless the property has no explicit
 901       // ownership.
 902       bool HasOwnership = (Attr & (ObjCPropertyDecl::OBJC_PR_retain |
 903                                    ObjCPropertyDecl::OBJC_PR_strong |
 904                                    ObjCPropertyDecl::OBJC_PR_copy |
 905                                    ObjCPropertyDecl::OBJC_PR_assign |
 906                                    ObjCPropertyDecl::OBJC_PR_unsafe_unretained |
 907                                    ObjCPropertyDecl::OBJC_PR_weak)) != 0;
 908       if (HasOwnership &&
 909           isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 910                                           ObjCPropertyDecl::OBJC_PR_copy)) {
 911         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_copy, "copy");
 912         continue;
 913       }
 914       if (HasOwnership && areIncompatiblePropertyAttributes(
 915                               OriginalAttributes, Attr,
 916                               ObjCPropertyDecl::OBJC_PR_retain |
 917                                   ObjCPropertyDecl::OBJC_PR_strong)) {
 918         Diag(OriginalAttributes & (ObjCPropertyDecl::OBJC_PR_retain |
 919                                    ObjCPropertyDecl::OBJC_PR_strong),
 920              "retain (or strong)");
 921         continue;
 922       }
 923       if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
 924                                           ObjCPropertyDecl::OBJC_PR_atomic)) {
 925         Diag(OriginalAttributes & ObjCPropertyDecl::OBJC_PR_atomic, "atomic");
 926         continue;
 927       }
 928     }
 929     if (Property->getGetterName() != Prop->getGetterName()) {
 930       Mismatches.push_back({Prop, DifferentGetter, ""});
 931       continue;
 932     }
 933     if (!Property->isReadOnly() && !Prop->isReadOnly() &&
 934         Property->getSetterName() != Prop->getSetterName()) {
 935       Mismatches.push_back({Prop, DifferentSetter, ""});
 936       continue;
 937     }
 938     QualType LHSType = S.Context.getCanonicalType(Prop->getType());
 939     if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
 940       bool IncompatibleObjC = false;
 941       QualType ConvertedType;
 942       if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
 943           || IncompatibleObjC) {
 944         Mismatches.push_back({Prop, IncompatibleType, ""});
 945         continue;
 946       }
 947     }
 948   }
 949
 950   if (Mismatches.empty())
 951     return Property;
 952
 953   // Diagnose incompability.
 954   {
 955     bool HasIncompatibleAttributes = false;
 956     for (const auto &Note : Mismatches)
 957       HasIncompatibleAttributes =
 958           Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
 959     // Promote the warning to an error if there are incompatible attributes or
 960     // incompatible types together with readwrite/readonly incompatibility.
 961     auto Diag = S.Diag(Property->getLocation(),
 962                        Property != OriginalProperty || HasIncompatibleAttributes
 963                            ? diag::err_protocol_property_mismatch
 964                            : diag::warn_protocol_property_mismatch);
 965     Diag << Mismatches[0].Kind;
 966     switch (Mismatches[0].Kind) {
 967     case IncompatibleType:
 968       Diag << Property->getType();
 969       break;
 970     case HasNoExpectedAttribute:
 971     case HasUnexpectedAttribute:
 972       Diag << Mismatches[0].AttributeName;
 973       break;
 974     case DifferentGetter:
 975       Diag << Property->getGetterName();
 976       break;
 977     case DifferentSetter:
 978       Diag << Property->getSetterName();
 979       break;
 980     }
 981   }
 982   for (const auto &Note : Mismatches) {
 983     auto Diag =
 984         S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
 985         << Note.Kind;
 986     switch (Note.Kind) {
 987     case IncompatibleType:
 988       Diag << Note.Prop->getType();
 989       break;
 990     case HasNoExpectedAttribute:
 991     case HasUnexpectedAttribute:
 992       Diag << Note.AttributeName;
 993       break;
 994     case DifferentGetter:
 995       Diag << Note.Prop->getGetterName();
 996       break;
 997     case DifferentSetter:
 998       Diag << Note.Prop->getSetterName();
 999       break;
1000     }
1001   }
1002   if (AtLoc.isValid())
1003     S.Diag(AtLoc, diag::note_property_synthesize);
1004
1005   return Property;
1006 }
1007
1008 /// Determine whether any storage attributes were written on the property.
1009 static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
1010                                        ObjCPropertyQueryKind QueryKind) {
1011   if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
1012
1013   // If this is a readwrite property in a class extension that refines
1014   // a readonly property in the original class definition, check it as
1015   // well.
1016
1017   // If it's a readonly property, we're not interested.
1018   if (Prop->isReadOnly()) return false;
1019
1020   // Is it declared in an extension?
1021   auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
1022   if (!Category || !Category->IsClassExtension()) return false;
1023
1024   // Find the corresponding property in the primary class definition.
1025   auto OrigClass = Category->getClassInterface();
1026   for (auto Found : OrigClass->lookup(Prop->getDeclName())) {
1027     if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
1028       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1029   }
1030
1031   // Look through all of the protocols.
1032   for (const auto *Proto : OrigClass->all_referenced_protocols()) {
1033     if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
1034             Prop->getIdentifier(), QueryKind))
1035       return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1036   }
1037
1038   return false;
1039 }
1040
1041 /// ActOnPropertyImplDecl - This routine performs semantic checks and
1042 /// builds the AST node for a property implementation declaration; declared
1043 /// as \@synthesize or \@dynamic.
1044 ///
1045 Decl *Sema::ActOnPropertyImplDecl(Scope *S,
1046                                   SourceLocation AtLoc,
1047                                   SourceLocation PropertyLoc,
1048                                   bool Synthesize,
1049                                   IdentifierInfo *PropertyId,
1050                                   IdentifierInfo *PropertyIvar,
1051                                   SourceLocation PropertyIvarLoc,
1052                                   ObjCPropertyQueryKind QueryKind) {
1053   ObjCContainerDecl *ClassImpDecl =
1054     dyn_cast<ObjCContainerDecl>(CurContext);
1055   // Make sure we have a context for the property implementation declaration.
1056   if (!ClassImpDecl) {
1057     Diag(AtLoc, diag::err_missing_property_context);
1058     return nullptr;
1059   }
1060   if (PropertyIvarLoc.isInvalid())
1061     PropertyIvarLoc = PropertyLoc;
1062   SourceLocation PropertyDiagLoc = PropertyLoc;
1063   if (PropertyDiagLoc.isInvalid())
1064     PropertyDiagLoc = ClassImpDecl->getBeginLoc();
1065   ObjCPropertyDecl *property = nullptr;
1066   ObjCInterfaceDecl *IDecl = nullptr;
1067   // Find the class or category class where this property must have
1068   // a declaration.
1069   ObjCImplementationDecl *IC = nullptr;
1070   ObjCCategoryImplDecl *CatImplClass = nullptr;
1071   if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
1072     IDecl = IC->getClassInterface();
1073     // We always synthesize an interface for an implementation
1074     // without an interface decl. So, IDecl is always non-zero.
1075     assert(IDecl &&
1076            "ActOnPropertyImplDecl - @implementation without @interface");
1077
1078     // Look for this property declaration in the @implementation's @interface
1079     property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
1080     if (!property) {
1081       Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
1082       return nullptr;
1083     }
1084     if (property->isClassProperty() && Synthesize) {
1085       Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
1086       return nullptr;
1087     }
1088     unsigned PIkind = property->getPropertyAttributesAsWritten();
1089     if ((PIkind & (ObjCPropertyDecl::OBJC_PR_atomic |
1090                    ObjCPropertyDecl::OBJC_PR_nonatomic) ) == 0) {
1091       if (AtLoc.isValid())
1092         Diag(AtLoc, diag::warn_implicit_atomic_property);
1093       else
1094         Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
1095       Diag(property->getLocation(), diag::note_property_declare);
1096     }
1097
1098     if (const ObjCCategoryDecl *CD =
1099         dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
1100       if (!CD->IsClassExtension()) {
1101         Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
1102         Diag(property->getLocation(), diag::note_property_declare);
1103         return nullptr;
1104       }
1105     }
1106     if (Synthesize&&
1107         (PIkind & ObjCPropertyDecl::OBJC_PR_readonly) &&
1108         property->hasAttr<IBOutletAttr>() &&
1109         !AtLoc.isValid()) {
1110       bool ReadWriteProperty = false;
1111       // Search into the class extensions and see if 'readonly property is
1112       // redeclared 'readwrite', then no warning is to be issued.
1113       for (auto *Ext : IDecl->known_extensions()) {
1114         DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
1115         if (!R.empty())
1116           if (ObjCPropertyDecl *ExtProp = dyn_cast<ObjCPropertyDecl>(R[0])) {
1117             PIkind = ExtProp->getPropertyAttributesAsWritten();
1118             if (PIkind & ObjCPropertyDecl::OBJC_PR_readwrite) {
1119               ReadWriteProperty = true;
1120               break;
1121             }
1122           }
1123       }
1124
1125       if (!ReadWriteProperty) {
1126         Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
1127             << property;
1128         SourceLocation readonlyLoc;
1129         if (LocPropertyAttribute(Context, "readonly",
1130                                  property->getLParenLoc(), readonlyLoc)) {
1131           SourceLocation endLoc =
1132             readonlyLoc.getLocWithOffset(strlen("readonly")-1);
1133           SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
1134           Diag(property->getLocation(),
1135                diag::note_auto_readonly_iboutlet_fixup_suggest) <<
1136           FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
1137         }
1138       }
1139     }
1140     if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
1141       property = SelectPropertyForSynthesisFromProtocols(*this, AtLoc, IDecl,
1142                                                          property);
1143
1144   } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
1145     if (Synthesize) {
1146       Diag(AtLoc, diag::err_synthesize_category_decl);
1147       return nullptr;
1148     }
1149     IDecl = CatImplClass->getClassInterface();
1150     if (!IDecl) {
1151       Diag(AtLoc, diag::err_missing_property_interface);
1152       return nullptr;
1153     }
1154     ObjCCategoryDecl *Category =
1155     IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
1156
1157     // If category for this implementation not found, it is an error which
1158     // has already been reported eralier.
1159     if (!Category)
1160       return nullptr;
1161     // Look for this property declaration in @implementation's category
1162     property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
1163     if (!property) {
1164       Diag(PropertyLoc, diag::err_bad_category_property_decl)
1165       << Category->getDeclName();
1166       return nullptr;
1167     }
1168   } else {
1169     Diag(AtLoc, diag::err_bad_property_context);
1170     return nullptr;
1171   }
1172   ObjCIvarDecl *Ivar = nullptr;
1173   bool CompleteTypeErr = false;
1174   bool compat = true;
1175   // Check that we have a valid, previously declared ivar for @synthesize
1176   if (Synthesize) {
1177     // @synthesize
1178     if (!PropertyIvar)
1179       PropertyIvar = PropertyId;
1180     // Check that this is a previously declared 'ivar' in 'IDecl' interface
1181     ObjCInterfaceDecl *ClassDeclared;
1182     Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
1183     QualType PropType = property->getType();
1184     QualType PropertyIvarType = PropType.getNonReferenceType();
1185
1186     if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
1187                             diag::err_incomplete_synthesized_property,
1188                             property->getDeclName())) {
1189       Diag(property->getLocation(), diag::note_property_declare);
1190       CompleteTypeErr = true;
1191     }
1192
1193     if (getLangOpts().ObjCAutoRefCount &&
1194         (property->getPropertyAttributesAsWritten() &
1195          ObjCPropertyDecl::OBJC_PR_readonly) &&
1196         PropertyIvarType->isObjCRetainableType()) {
1197       setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
1198     }
1199
1200     ObjCPropertyDecl::PropertyAttributeKind kind
1201       = property->getPropertyAttributes();
1202
1203     bool isARCWeak = false;
1204     if (kind & ObjCPropertyDecl::OBJC_PR_weak) {
1205       // Add GC __weak to the ivar type if the property is weak.
1206       if (getLangOpts().getGC() != LangOptions::NonGC) {
1207         assert(!getLangOpts().ObjCAutoRefCount);
1208         if (PropertyIvarType.isObjCGCStrong()) {
1209           Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
1210           Diag(property->getLocation(), diag::note_property_declare);
1211         } else {
1212           PropertyIvarType =
1213             Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
1214         }
1215
1216       // Otherwise, check whether ARC __weak is enabled and works with
1217       // the property type.
1218       } else {
1219         if (!getLangOpts().ObjCWeak) {
1220           // Only complain here when synthesizing an ivar.
1221           if (!Ivar) {
1222             Diag(PropertyDiagLoc,
1223                  getLangOpts().ObjCWeakRuntime
1224                    ? diag::err_synthesizing_arc_weak_property_disabled
1225                    : diag::err_synthesizing_arc_weak_property_no_runtime);
1226             Diag(property->getLocation(), diag::note_property_declare);
1227           }
1228           CompleteTypeErr = true; // suppress later diagnostics about the ivar
1229         } else {
1230           isARCWeak = true;
1231           if (const ObjCObjectPointerType *ObjT =
1232                 PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1233             const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1234             if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1235               Diag(property->getLocation(),
1236                    diag::err_arc_weak_unavailable_property)
1237                 << PropertyIvarType;
1238               Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1239                 << ClassImpDecl->getName();
1240             }
1241           }
1242         }
1243       }
1244     }
1245
1246     if (AtLoc.isInvalid()) {
1247       // Check when default synthesizing a property that there is
1248       // an ivar matching property name and issue warning; since this
1249       // is the most common case of not using an ivar used for backing
1250       // property in non-default synthesis case.
1251       ObjCInterfaceDecl *ClassDeclared=nullptr;
1252       ObjCIvarDecl *originalIvar =
1253       IDecl->lookupInstanceVariable(property->getIdentifier(),
1254                                     ClassDeclared);
1255       if (originalIvar) {
1256         Diag(PropertyDiagLoc,
1257              diag::warn_autosynthesis_property_ivar_match)
1258         << PropertyId << (Ivar == nullptr) << PropertyIvar
1259         << originalIvar->getIdentifier();
1260         Diag(property->getLocation(), diag::note_property_declare);
1261         Diag(originalIvar->getLocation(), diag::note_ivar_decl);
1262       }
1263     }
1264
1265     if (!Ivar) {
1266       // In ARC, give the ivar a lifetime qualifier based on the
1267       // property attributes.
1268       if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
1269           !PropertyIvarType.getObjCLifetime() &&
1270           PropertyIvarType->isObjCRetainableType()) {
1271
1272         // It's an error if we have to do this and the user didn't
1273         // explicitly write an ownership attribute on the property.
1274         if (!hasWrittenStorageAttribute(property, QueryKind) &&
1275             !(kind & ObjCPropertyDecl::OBJC_PR_strong)) {
1276           Diag(PropertyDiagLoc,
1277                diag::err_arc_objc_property_default_assign_on_object);
1278           Diag(property->getLocation(), diag::note_property_declare);
1279         } else {
1280           Qualifiers::ObjCLifetime lifetime =
1281             getImpliedARCOwnership(kind, PropertyIvarType);
1282           assert(lifetime && "no lifetime for property?");
1283
1284           Qualifiers qs;
1285           qs.addObjCLifetime(lifetime);
1286           PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1287         }
1288       }
1289
1290       Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1291                                   PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1292                                   PropertyIvarType, /*Dinfo=*/nullptr,
1293                                   ObjCIvarDecl::Private,
1294                                   (Expr *)nullptr, true);
1295       if (RequireNonAbstractType(PropertyIvarLoc,
1296                                  PropertyIvarType,
1297                                  diag::err_abstract_type_in_decl,
1298                                  AbstractSynthesizedIvarType)) {
1299         Diag(property->getLocation(), diag::note_property_declare);
1300         // An abstract type is as bad as an incomplete type.
1301         CompleteTypeErr = true;
1302       }
1303       if (!CompleteTypeErr) {
1304         const RecordType *RecordTy = PropertyIvarType->getAs<RecordType>();
1305         if (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()) {
1306           Diag(PropertyIvarLoc, diag::err_synthesize_variable_sized_ivar)
1307             << PropertyIvarType;
1308           CompleteTypeErr = true; // suppress later diagnostics about the ivar
1309         }
1310       }
1311       if (CompleteTypeErr)
1312         Ivar->setInvalidDecl();
1313       ClassImpDecl->addDecl(Ivar);
1314       IDecl->makeDeclVisibleInContext(Ivar);
1315
1316       if (getLangOpts().ObjCRuntime.isFragile())
1317         Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
1318             << PropertyId;
1319       // Note! I deliberately want it to fall thru so, we have a
1320       // a property implementation and to avoid future warnings.
1321     } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1322                !declaresSameEntity(ClassDeclared, IDecl)) {
1323       Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
1324       << property->getDeclName() << Ivar->getDeclName()
1325       << ClassDeclared->getDeclName();
1326       Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1327       << Ivar << Ivar->getName();
1328       // Note! I deliberately want it to fall thru so more errors are caught.
1329     }
1330     property->setPropertyIvarDecl(Ivar);
1331
1332     QualType IvarType = Context.getCanonicalType(Ivar->getType());
1333
1334     // Check that type of property and its ivar are type compatible.
1335     if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1336       if (isa<ObjCObjectPointerType>(PropertyIvarType)
1337           && isa<ObjCObjectPointerType>(IvarType))
1338         compat =
1339           Context.canAssignObjCInterfaces(
1340                                   PropertyIvarType->getAs<ObjCObjectPointerType>(),
1341                                   IvarType->getAs<ObjCObjectPointerType>());
1342       else {
1343         compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1344                                              IvarType)
1345                     == Compatible);
1346       }
1347       if (!compat) {
1348         Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1349           << property->getDeclName() << PropType
1350           << Ivar->getDeclName() << IvarType;
1351         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1352         // Note! I deliberately want it to fall thru so, we have a
1353         // a property implementation and to avoid future warnings.
1354       }
1355       else {
1356         // FIXME! Rules for properties are somewhat different that those
1357         // for assignments. Use a new routine to consolidate all cases;
1358         // specifically for property redeclarations as well as for ivars.
1359         QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1360         QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1361         if (lhsType != rhsType &&
1362             lhsType->isArithmeticType()) {
1363           Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1364             << property->getDeclName() << PropType
1365             << Ivar->getDeclName() << IvarType;
1366           Diag(Ivar->getLocation(), diag::note_ivar_decl);
1367           // Fall thru - see previous comment
1368         }
1369       }
1370       // __weak is explicit. So it works on Canonical type.
1371       if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1372            getLangOpts().getGC() != LangOptions::NonGC)) {
1373         Diag(PropertyDiagLoc, diag::err_weak_property)
1374         << property->getDeclName() << Ivar->getDeclName();
1375         Diag(Ivar->getLocation(), diag::note_ivar_decl);
1376         // Fall thru - see previous comment
1377       }
1378       // Fall thru - see previous comment
1379       if ((property->getType()->isObjCObjectPointerType() ||
1380            PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1381           getLangOpts().getGC() != LangOptions::NonGC) {
1382         Diag(PropertyDiagLoc, diag::err_strong_property)
1383         << property->getDeclName() << Ivar->getDeclName();
1384         // Fall thru - see previous comment
1385       }
1386     }
1387     if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1388         Ivar->getType().getObjCLifetime())
1389       checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1390   } else if (PropertyIvar)
1391     // @dynamic
1392     Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
1393
1394   assert (property && "ActOnPropertyImplDecl - property declaration missing");
1395   ObjCPropertyImplDecl *PIDecl =
1396   ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1397                                property,
1398                                (Synthesize ?
1399                                 ObjCPropertyImplDecl::Synthesize
1400                                 : ObjCPropertyImplDecl::Dynamic),
1401                                Ivar, PropertyIvarLoc);
1402
1403   if (CompleteTypeErr || !compat)
1404     PIDecl->setInvalidDecl();
1405
1406   if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1407     getterMethod->createImplicitParams(Context, IDecl);
1408     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1409         Ivar->getType()->isRecordType()) {
1410       // For Objective-C++, need to synthesize the AST for the IVAR object to be
1411       // returned by the getter as it must conform to C++'s copy-return rules.
1412       // FIXME. Eventually we want to do this for Objective-C as well.
1413       SynthesizedFunctionScope Scope(*this, getterMethod);
1414       ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1415       DeclRefExpr *SelfExpr = new (Context)
1416           DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1417                       PropertyDiagLoc);
1418       MarkDeclRefReferenced(SelfExpr);
1419       Expr *LoadSelfExpr =
1420         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1421                                  CK_LValueToRValue, SelfExpr, nullptr,
1422                                  VK_RValue);
1423       Expr *IvarRefExpr =
1424         new (Context) ObjCIvarRefExpr(Ivar,
1425                                       Ivar->getUsageType(SelfDecl->getType()),
1426                                       PropertyDiagLoc,
1427                                       Ivar->getLocation(),
1428                                       LoadSelfExpr, true, true);
1429       ExprResult Res = PerformCopyInitialization(
1430           InitializedEntity::InitializeResult(PropertyDiagLoc,
1431                                               getterMethod->getReturnType(),
1432                                               /*NRVO=*/false),
1433           PropertyDiagLoc, IvarRefExpr);
1434       if (!Res.isInvalid()) {
1435         Expr *ResExpr = Res.getAs<Expr>();
1436         if (ResExpr)
1437           ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1438         PIDecl->setGetterCXXConstructor(ResExpr);
1439       }
1440     }
1441     if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1442         !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1443       Diag(getterMethod->getLocation(),
1444            diag::warn_property_getter_owning_mismatch);
1445       Diag(property->getLocation(), diag::note_property_declare);
1446     }
1447     if (getLangOpts().ObjCAutoRefCount && Synthesize)
1448       switch (getterMethod->getMethodFamily()) {
1449         case OMF_retain:
1450         case OMF_retainCount:
1451         case OMF_release:
1452         case OMF_autorelease:
1453           Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1454             << 1 << getterMethod->getSelector();
1455           break;
1456         default:
1457           break;
1458       }
1459   }
1460   if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1461     setterMethod->createImplicitParams(Context, IDecl);
1462     if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1463         Ivar->getType()->isRecordType()) {
1464       // FIXME. Eventually we want to do this for Objective-C as well.
1465       SynthesizedFunctionScope Scope(*this, setterMethod);
1466       ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1467       DeclRefExpr *SelfExpr = new (Context)
1468           DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1469                       PropertyDiagLoc);
1470       MarkDeclRefReferenced(SelfExpr);
1471       Expr *LoadSelfExpr =
1472         ImplicitCastExpr::Create(Context, SelfDecl->getType(),
1473                                  CK_LValueToRValue, SelfExpr, nullptr,
1474                                  VK_RValue);
1475       Expr *lhs =
1476         new (Context) ObjCIvarRefExpr(Ivar,
1477                                       Ivar->getUsageType(SelfDecl->getType()),
1478                                       PropertyDiagLoc,
1479                                       Ivar->getLocation(),
1480                                       LoadSelfExpr, true, true);
1481       ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1482       ParmVarDecl *Param = (*P);
1483       QualType T = Param->getType().getNonReferenceType();
1484       DeclRefExpr *rhs = new (Context)
1485           DeclRefExpr(Context, Param, false, T, VK_LValue, PropertyDiagLoc);
1486       MarkDeclRefReferenced(rhs);
1487       ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1488                                   BO_Assign, lhs, rhs);
1489       if (property->getPropertyAttributes() &
1490           ObjCPropertyDecl::OBJC_PR_atomic) {
1491         Expr *callExpr = Res.getAs<Expr>();
1492         if (const CXXOperatorCallExpr *CXXCE =
1493               dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1494           if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1495             if (!FuncDecl->isTrivial())
1496               if (property->getType()->isReferenceType()) {
1497                 Diag(PropertyDiagLoc,
1498                      diag::err_atomic_property_nontrivial_assign_op)
1499                     << property->getType();
1500                 Diag(FuncDecl->getBeginLoc(), diag::note_callee_decl)
1501                     << FuncDecl;
1502               }
1503       }
1504       PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1505     }
1506   }
1507
1508   if (IC) {
1509     if (Synthesize)
1510       if (ObjCPropertyImplDecl *PPIDecl =
1511           IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1512         Diag(PropertyLoc, diag::err_duplicate_ivar_use)
1513         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1514         << PropertyIvar;
1515         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1516       }
1517
1518     if (ObjCPropertyImplDecl *PPIDecl
1519         = IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
1520       Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
1521       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1522       return nullptr;
1523     }
1524     IC->addPropertyImplementation(PIDecl);
1525     if (getLangOpts().ObjCDefaultSynthProperties &&
1526         getLangOpts().ObjCRuntime.isNonFragile() &&
1527         !IDecl->isObjCRequiresPropertyDefs()) {
1528       // Diagnose if an ivar was lazily synthesdized due to a previous
1529       // use and if 1) property is @dynamic or 2) property is synthesized
1530       // but it requires an ivar of different name.
1531       ObjCInterfaceDecl *ClassDeclared=nullptr;
1532       ObjCIvarDecl *Ivar = nullptr;
1533       if (!Synthesize)
1534         Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1535       else {
1536         if (PropertyIvar && PropertyIvar != PropertyId)
1537           Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1538       }
1539       // Issue diagnostics only if Ivar belongs to current class.
1540       if (Ivar && Ivar->getSynthesize() &&
1541           declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1542         Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1543         << PropertyId;
1544         Ivar->setInvalidDecl();
1545       }
1546     }
1547   } else {
1548     if (Synthesize)
1549       if (ObjCPropertyImplDecl *PPIDecl =
1550           CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1551         Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
1552         << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1553         << PropertyIvar;
1554         Diag(PPIDecl->getLocation(), diag::note_previous_use);
1555       }
1556
1557     if (ObjCPropertyImplDecl *PPIDecl =
1558         CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
1559       Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
1560       Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1561       return nullptr;
1562     }
1563     CatImplClass->addPropertyImplementation(PIDecl);
1564   }
1565
1566   return PIDecl;
1567 }
1568
1569 //===----------------------------------------------------------------------===//
1570 // Helper methods.
1571 //===----------------------------------------------------------------------===//
1572
1573 /// DiagnosePropertyMismatch - Compares two properties for their
1574 /// attributes and types and warns on a variety of inconsistencies.
1575 ///
1576 void
1577 Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1578                                ObjCPropertyDecl *SuperProperty,
1579                                const IdentifierInfo *inheritedName,
1580                                bool OverridingProtocolProperty) {
1581   ObjCPropertyDecl::PropertyAttributeKind CAttr =
1582     Property->getPropertyAttributes();
1583   ObjCPropertyDecl::PropertyAttributeKind SAttr =
1584     SuperProperty->getPropertyAttributes();
1585
1586   // We allow readonly properties without an explicit ownership
1587   // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1588   // to be overridden by a property with any explicit ownership in the subclass.
1589   if (!OverridingProtocolProperty &&
1590       !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1591     ;
1592   else {
1593     if ((CAttr & ObjCPropertyDecl::OBJC_PR_readonly)
1594         && (SAttr & ObjCPropertyDecl::OBJC_PR_readwrite))
1595       Diag(Property->getLocation(), diag::warn_readonly_property)
1596         << Property->getDeclName() << inheritedName;
1597     if ((CAttr & ObjCPropertyDecl::OBJC_PR_copy)
1598         != (SAttr & ObjCPropertyDecl::OBJC_PR_copy))
1599       Diag(Property->getLocation(), diag::warn_property_attribute)
1600         << Property->getDeclName() << "copy" << inheritedName;
1601     else if (!(SAttr & ObjCPropertyDecl::OBJC_PR_readonly)){
1602       unsigned CAttrRetain =
1603         (CAttr &
1604          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1605       unsigned SAttrRetain =
1606         (SAttr &
1607          (ObjCPropertyDecl::OBJC_PR_retain | ObjCPropertyDecl::OBJC_PR_strong));
1608       bool CStrong = (CAttrRetain != 0);
1609       bool SStrong = (SAttrRetain != 0);
1610       if (CStrong != SStrong)
1611         Diag(Property->getLocation(), diag::warn_property_attribute)
1612           << Property->getDeclName() << "retain (or strong)" << inheritedName;
1613     }
1614   }
1615
1616   // Check for nonatomic; note that nonatomic is effectively
1617   // meaningless for readonly properties, so don't diagnose if the
1618   // atomic property is 'readonly'.
1619   checkAtomicPropertyMismatch(*this, SuperProperty, Property, false);
1620   // Readonly properties from protocols can be implemented as "readwrite"
1621   // with a custom setter name.
1622   if (Property->getSetterName() != SuperProperty->getSetterName() &&
1623       !(SuperProperty->isReadOnly() &&
1624         isa<ObjCProtocolDecl>(SuperProperty->getDeclContext()))) {
1625     Diag(Property->getLocation(), diag::warn_property_attribute)
1626       << Property->getDeclName() << "setter" << inheritedName;
1627     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1628   }
1629   if (Property->getGetterName() != SuperProperty->getGetterName()) {
1630     Diag(Property->getLocation(), diag::warn_property_attribute)
1631       << Property->getDeclName() << "getter" << inheritedName;
1632     Diag(SuperProperty->getLocation(), diag::note_property_declare);
1633   }
1634
1635   QualType LHSType =
1636     Context.getCanonicalType(SuperProperty->getType());
1637   QualType RHSType =
1638     Context.getCanonicalType(Property->getType());
1639
1640   if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1641     // Do cases not handled in above.
1642     // FIXME. For future support of covariant property types, revisit this.
1643     bool IncompatibleObjC = false;
1644     QualType ConvertedType;
1645     if (!isObjCPointerConversion(RHSType, LHSType,
1646                                  ConvertedType, IncompatibleObjC) ||
1647         IncompatibleObjC) {
1648         Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1649         << Property->getType() << SuperProperty->getType() << inheritedName;
1650       Diag(SuperProperty->getLocation(), diag::note_property_declare);
1651     }
1652   }
1653 }
1654
1655 bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1656                                             ObjCMethodDecl *GetterMethod,
1657                                             SourceLocation Loc) {
1658   if (!GetterMethod)
1659     return false;
1660   QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1661   QualType PropertyRValueType =
1662       property->getType().getNonReferenceType().getAtomicUnqualifiedType();
1663   bool compat = Context.hasSameType(PropertyRValueType, GetterType);
1664   if (!compat) {
1665     const ObjCObjectPointerType *propertyObjCPtr = nullptr;
1666     const ObjCObjectPointerType *getterObjCPtr = nullptr;
1667     if ((propertyObjCPtr =
1668              PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
1669         (getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
1670       compat = Context.canAssignObjCInterfaces(getterObjCPtr, propertyObjCPtr);
1671     else if (CheckAssignmentConstraints(Loc, GetterType, PropertyRValueType)
1672               != Compatible) {
1673           Diag(Loc, diag::err_property_accessor_type)
1674             << property->getDeclName() << PropertyRValueType
1675             << GetterMethod->getSelector() << GetterType;
1676           Diag(GetterMethod->getLocation(), diag::note_declared_at);
1677           return true;
1678     } else {
1679       compat = true;
1680       QualType lhsType = Context.getCanonicalType(PropertyRValueType);
1681       QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1682       if (lhsType != rhsType && lhsType->isArithmeticType())
1683         compat = false;
1684     }
1685   }
1686
1687   if (!compat) {
1688     Diag(Loc, diag::warn_accessor_property_type_mismatch)
1689     << property->getDeclName()
1690     << GetterMethod->getSelector();
1691     Diag(GetterMethod->getLocation(), diag::note_declared_at);
1692     return true;
1693   }
1694
1695   return false;
1696 }
1697
1698 /// CollectImmediateProperties - This routine collects all properties in
1699 /// the class and its conforming protocols; but not those in its super class.
1700 static void
1701 CollectImmediateProperties(ObjCContainerDecl *CDecl,
1702                            ObjCContainerDecl::PropertyMap &PropMap,
1703                            ObjCContainerDecl::PropertyMap &SuperPropMap,
1704                            bool CollectClassPropsOnly = false,
1705                            bool IncludeProtocols = true) {
1706   if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1707     for (auto *Prop : IDecl->properties()) {
1708       if (CollectClassPropsOnly && !Prop->isClassProperty())
1709         continue;
1710       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1711           Prop;
1712     }
1713
1714     // Collect the properties from visible extensions.
1715     for (auto *Ext : IDecl->visible_extensions())
1716       CollectImmediateProperties(Ext, PropMap, SuperPropMap,
1717                                  CollectClassPropsOnly, IncludeProtocols);
1718
1719     if (IncludeProtocols) {
1720       // Scan through class's protocols.
1721       for (auto *PI : IDecl->all_referenced_protocols())
1722         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1723                                    CollectClassPropsOnly);
1724     }
1725   }
1726   if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1727     for (auto *Prop : CATDecl->properties()) {
1728       if (CollectClassPropsOnly && !Prop->isClassProperty())
1729         continue;
1730       PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1731           Prop;
1732     }
1733     if (IncludeProtocols) {
1734       // Scan through class's protocols.
1735       for (auto *PI : CATDecl->protocols())
1736         CollectImmediateProperties(PI, PropMap, SuperPropMap,
1737                                    CollectClassPropsOnly);
1738     }
1739   }
1740   else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1741     for (auto *Prop : PDecl->properties()) {
1742       if (CollectClassPropsOnly && !Prop->isClassProperty())
1743         continue;
1744       ObjCPropertyDecl *PropertyFromSuper =
1745           SuperPropMap[std::make_pair(Prop->getIdentifier(),
1746                                       Prop->isClassProperty())];
1747       // Exclude property for protocols which conform to class's super-class,
1748       // as super-class has to implement the property.
1749       if (!PropertyFromSuper ||
1750           PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1751         ObjCPropertyDecl *&PropEntry =
1752             PropMap[std::make_pair(Prop->getIdentifier(),
1753                                    Prop->isClassProperty())];
1754         if (!PropEntry)
1755           PropEntry = Prop;
1756       }
1757     }
1758     // Scan through protocol's protocols.
1759     for (auto *PI : PDecl->protocols())
1760       CollectImmediateProperties(PI, PropMap, SuperPropMap,
1761                                  CollectClassPropsOnly);
1762   }
1763 }
1764
1765 /// CollectSuperClassPropertyImplementations - This routine collects list of
1766 /// properties to be implemented in super class(s) and also coming from their
1767 /// conforming protocols.
1768 static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1769                                     ObjCInterfaceDecl::PropertyMap &PropMap) {
1770   if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1771     ObjCInterfaceDecl::PropertyDeclOrder PO;
1772     while (SDecl) {
1773       SDecl->collectPropertiesToImplement(PropMap, PO);
1774       SDecl = SDecl->getSuperClass();
1775     }
1776   }
1777 }
1778
1779 /// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1780 /// an ivar synthesized for 'Method' and 'Method' is a property accessor
1781 /// declared in class 'IFace'.
1782 bool
1783 Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1784                                      ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1785   if (!IV->getSynthesize())
1786     return false;
1787   ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1788                                             Method->isInstanceMethod());
1789   if (!IMD || !IMD->isPropertyAccessor())
1790     return false;
1791
1792   // look up a property declaration whose one of its accessors is implemented
1793   // by this method.
1794   for (const auto *Property : IFace->instance_properties()) {
1795     if ((Property->getGetterName() == IMD->getSelector() ||
1796          Property->getSetterName() == IMD->getSelector()) &&
1797         (Property->getPropertyIvarDecl() == IV))
1798       return true;
1799   }
1800   // Also look up property declaration in class extension whose one of its
1801   // accessors is implemented by this method.
1802   for (const auto *Ext : IFace->known_extensions())
1803     for (const auto *Property : Ext->instance_properties())
1804       if ((Property->getGetterName() == IMD->getSelector() ||
1805            Property->getSetterName() == IMD->getSelector()) &&
1806           (Property->getPropertyIvarDecl() == IV))
1807         return true;
1808   return false;
1809 }
1810
1811 static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1812                                          ObjCPropertyDecl *Prop) {
1813   bool SuperClassImplementsGetter = false;
1814   bool SuperClassImplementsSetter = false;
1815   if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1816     SuperClassImplementsSetter = true;
1817
1818   while (IDecl->getSuperClass()) {
1819     ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1820     if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1821       SuperClassImplementsGetter = true;
1822
1823     if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1824       SuperClassImplementsSetter = true;
1825     if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1826       return true;
1827     IDecl = IDecl->getSuperClass();
1828   }
1829   return false;
1830 }
1831
1832 /// Default synthesizes all properties which must be synthesized
1833 /// in class's \@implementation.
1834 void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
1835                                        ObjCInterfaceDecl *IDecl,
1836                                        SourceLocation AtEnd) {
1837   ObjCInterfaceDecl::PropertyMap PropMap;
1838   ObjCInterfaceDecl::PropertyDeclOrder PropertyOrder;
1839   IDecl->collectPropertiesToImplement(PropMap, PropertyOrder);
1840   if (PropMap.empty())
1841     return;
1842   ObjCInterfaceDecl::PropertyMap SuperPropMap;
1843   CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1844
1845   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
1846     ObjCPropertyDecl *Prop = PropertyOrder[i];
1847     // Is there a matching property synthesize/dynamic?
1848     if (Prop->isInvalidDecl() ||
1849         Prop->isClassProperty() ||
1850         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1851       continue;
1852     // Property may have been synthesized by user.
1853     if (IMPDecl->FindPropertyImplDecl(
1854             Prop->getIdentifier(), Prop->getQueryKind()))
1855       continue;
1856     if (IMPDecl->getInstanceMethod(Prop->getGetterName())) {
1857       if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readonly)
1858         continue;
1859       if (IMPDecl->getInstanceMethod(Prop->getSetterName()))
1860         continue;
1861     }
1862     if (ObjCPropertyImplDecl *PID =
1863         IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1864       Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1865         << Prop->getIdentifier();
1866       if (PID->getLocation().isValid())
1867         Diag(PID->getLocation(), diag::note_property_synthesize);
1868       continue;
1869     }
1870     ObjCPropertyDecl *PropInSuperClass =
1871         SuperPropMap[std::make_pair(Prop->getIdentifier(),
1872                                     Prop->isClassProperty())];
1873     if (ObjCProtocolDecl *Proto =
1874           dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1875       // We won't auto-synthesize properties declared in protocols.
1876       // Suppress the warning if class's superclass implements property's
1877       // getter and implements property's setter (if readwrite property).
1878       // Or, if property is going to be implemented in its super class.
1879       if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1880         Diag(IMPDecl->getLocation(),
1881              diag::warn_auto_synthesizing_protocol_property)
1882           << Prop << Proto;
1883         Diag(Prop->getLocation(), diag::note_property_declare);
1884         std::string FixIt =
1885             (Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
1886         Diag(AtEnd, diag::note_add_synthesize_directive)
1887             << FixItHint::CreateInsertion(AtEnd, FixIt);
1888       }
1889       continue;
1890     }
1891     // If property to be implemented in the super class, ignore.
1892     if (PropInSuperClass) {
1893       if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
1894           (PropInSuperClass->getPropertyAttributes() &
1895            ObjCPropertyDecl::OBJC_PR_readonly) &&
1896           !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1897           !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1898         Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1899         << Prop->getIdentifier();
1900         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1901       }
1902       else {
1903         Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1904         << Prop->getIdentifier();
1905         Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1906         Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1907       }
1908       continue;
1909     }
1910     // We use invalid SourceLocations for the synthesized ivars since they
1911     // aren't really synthesized at a particular location; they just exist.
1912     // Saying that they are located at the @implementation isn't really going
1913     // to help users.
1914     ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1915       ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1916                             true,
1917                             /* property = */ Prop->getIdentifier(),
1918                             /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1919                             Prop->getLocation(), Prop->getQueryKind()));
1920     if (PIDecl && !Prop->isUnavailable()) {
1921       Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1922       Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1923     }
1924   }
1925 }
1926
1927 void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
1928                                        SourceLocation AtEnd) {
1929   if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1930     return;
1931   ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1932   if (!IC)
1933     return;
1934   if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1935     if (!IDecl->isObjCRequiresPropertyDefs())
1936       DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
1937 }
1938
1939 static void DiagnoseUnimplementedAccessor(
1940     Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
1941     ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
1942     ObjCPropertyDecl *Prop,
1943     llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
1944   // Check to see if we have a corresponding selector in SMap and with the
1945   // right method type.
1946   auto I = std::find_if(SMap.begin(), SMap.end(),
1947     [&](const ObjCMethodDecl *x) {
1948       return x->getSelector() == Method &&
1949              x->isClassMethod() == Prop->isClassProperty();
1950     });
1951   // When reporting on missing property setter/getter implementation in
1952   // categories, do not report when they are declared in primary class,
1953   // class's protocol, or one of it super classes. This is because,
1954   // the class is going to implement them.
1955   if (I == SMap.end() &&
1956       (PrimaryClass == nullptr ||
1957        !PrimaryClass->lookupPropertyAccessor(Method, C,
1958                                              Prop->isClassProperty()))) {
1959     unsigned diag =
1960         isa<ObjCCategoryDecl>(CDecl)
1961             ? (Prop->isClassProperty()
1962                    ? diag::warn_impl_required_in_category_for_class_property
1963                    : diag::warn_setter_getter_impl_required_in_category)
1964             : (Prop->isClassProperty()
1965                    ? diag::warn_impl_required_for_class_property
1966                    : diag::warn_setter_getter_impl_required);
1967     S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
1968     S.Diag(Prop->getLocation(), diag::note_property_declare);
1969     if (S.LangOpts.ObjCDefaultSynthProperties &&
1970         S.LangOpts.ObjCRuntime.isNonFragile())
1971       if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
1972         if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
1973           S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
1974   }
1975 }
1976
1977 void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
1978                                            ObjCContainerDecl *CDecl,
1979                                            bool SynthesizeProperties) {
1980   ObjCContainerDecl::PropertyMap PropMap;
1981   ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
1982
1983   // Since we don't synthesize class properties, we should emit diagnose even
1984   // if SynthesizeProperties is true.
1985   ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
1986   // Gather properties which need not be implemented in this class
1987   // or category.
1988   if (!IDecl)
1989     if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1990       // For categories, no need to implement properties declared in
1991       // its primary class (and its super classes) if property is
1992       // declared in one of those containers.
1993       if ((IDecl = C->getClassInterface())) {
1994         ObjCInterfaceDecl::PropertyDeclOrder PO;
1995         IDecl->collectPropertiesToImplement(NoNeedToImplPropMap, PO);
1996       }
1997     }
1998   if (IDecl)
1999     CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
2000
2001   // When SynthesizeProperties is true, we only check class properties.
2002   CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap,
2003                              SynthesizeProperties/*CollectClassPropsOnly*/);
2004
2005   // Scan the @interface to see if any of the protocols it adopts
2006   // require an explicit implementation, via attribute
2007   // 'objc_protocol_requires_explicit_implementation'.
2008   if (IDecl) {
2009     std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
2010
2011     for (auto *PDecl : IDecl->all_referenced_protocols()) {
2012       if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2013         continue;
2014       // Lazily construct a set of all the properties in the @interface
2015       // of the class, without looking at the superclass.  We cannot
2016       // use the call to CollectImmediateProperties() above as that
2017       // utilizes information from the super class's properties as well
2018       // as scans the adopted protocols.  This work only triggers for protocols
2019       // with the attribute, which is very rare, and only occurs when
2020       // analyzing the @implementation.
2021       if (!LazyMap) {
2022         ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2023         LazyMap.reset(new ObjCContainerDecl::PropertyMap());
2024         CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
2025                                    /* CollectClassPropsOnly */ false,
2026                                    /* IncludeProtocols */ false);
2027       }
2028       // Add the properties of 'PDecl' to the list of properties that
2029       // need to be implemented.
2030       for (auto *PropDecl : PDecl->properties()) {
2031         if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
2032                                       PropDecl->isClassProperty())])
2033           continue;
2034         PropMap[std::make_pair(PropDecl->getIdentifier(),
2035                                PropDecl->isClassProperty())] = PropDecl;
2036       }
2037     }
2038   }
2039
2040   if (PropMap.empty())
2041     return;
2042
2043   llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
2044   for (const auto *I : IMPDecl->property_impls())
2045     PropImplMap.insert(I->getPropertyDecl());
2046
2047   llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
2048   // Collect property accessors implemented in current implementation.
2049   for (const auto *I : IMPDecl->methods())
2050     InsMap.insert(I);
2051
2052   ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2053   ObjCInterfaceDecl *PrimaryClass = nullptr;
2054   if (C && !C->IsClassExtension())
2055     if ((PrimaryClass = C->getClassInterface()))
2056       // Report unimplemented properties in the category as well.
2057       if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
2058         // When reporting on missing setter/getters, do not report when
2059         // setter/getter is implemented in category's primary class
2060         // implementation.
2061         for (const auto *I : IMP->methods())
2062           InsMap.insert(I);
2063       }
2064
2065   for (ObjCContainerDecl::PropertyMap::iterator
2066        P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
2067     ObjCPropertyDecl *Prop = P->second;
2068     // Is there a matching property synthesize/dynamic?
2069     if (Prop->isInvalidDecl() ||
2070         Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
2071         PropImplMap.count(Prop) ||
2072         Prop->getAvailability() == AR_Unavailable)
2073       continue;
2074
2075     // Diagnose unimplemented getters and setters.
2076     DiagnoseUnimplementedAccessor(*this,
2077           PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
2078     if (!Prop->isReadOnly())
2079       DiagnoseUnimplementedAccessor(*this,
2080                                     PrimaryClass, Prop->getSetterName(),
2081                                     IMPDecl, CDecl, C, Prop, InsMap);
2082   }
2083 }
2084
2085 void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
2086   for (const auto *propertyImpl : impDecl->property_impls()) {
2087     const auto *property = propertyImpl->getPropertyDecl();
2088
2089     // Warn about null_resettable properties with synthesized setters,
2090     // because the setter won't properly handle nil.
2091     if (propertyImpl->getPropertyImplementation()
2092           == ObjCPropertyImplDecl::Synthesize &&
2093         (property->getPropertyAttributes() &
2094          ObjCPropertyDecl::OBJC_PR_null_resettable) &&
2095         property->getGetterMethodDecl() &&
2096         property->getSetterMethodDecl()) {
2097       auto *getterMethod = property->getGetterMethodDecl();
2098       auto *setterMethod = property->getSetterMethodDecl();
2099       if (!impDecl->getInstanceMethod(setterMethod->getSelector()) &&
2100           !impDecl->getInstanceMethod(getterMethod->getSelector())) {
2101         SourceLocation loc = propertyImpl->getLocation();
2102         if (loc.isInvalid())
2103           loc = impDecl->getBeginLoc();
2104
2105         Diag(loc, diag::warn_null_resettable_setter)
2106           << setterMethod->getSelector() << property->getDeclName();
2107       }
2108     }
2109   }
2110 }
2111
2112 void
2113 Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
2114                                        ObjCInterfaceDecl* IDecl) {
2115   // Rules apply in non-GC mode only
2116   if (getLangOpts().getGC() != LangOptions::NonGC)
2117     return;
2118   ObjCContainerDecl::PropertyMap PM;
2119   for (auto *Prop : IDecl->properties())
2120     PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2121   for (const auto *Ext : IDecl->known_extensions())
2122     for (auto *Prop : Ext->properties())
2123       PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2124
2125   for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
2126        I != E; ++I) {
2127     const ObjCPropertyDecl *Property = I->second;
2128     ObjCMethodDecl *GetterMethod = nullptr;
2129     ObjCMethodDecl *SetterMethod = nullptr;
2130     bool LookedUpGetterSetter = false;
2131
2132     unsigned Attributes = Property->getPropertyAttributes();
2133     unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
2134
2135     if (!(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic) &&
2136         !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_nonatomic)) {
2137       GetterMethod = Property->isClassProperty() ?
2138                      IMPDecl->getClassMethod(Property->getGetterName()) :
2139                      IMPDecl->getInstanceMethod(Property->getGetterName());
2140       SetterMethod = Property->isClassProperty() ?
2141                      IMPDecl->getClassMethod(Property->getSetterName()) :
2142                      IMPDecl->getInstanceMethod(Property->getSetterName());
2143       LookedUpGetterSetter = true;
2144       if (GetterMethod) {
2145         Diag(GetterMethod->getLocation(),
2146              diag::warn_default_atomic_custom_getter_setter)
2147           << Property->getIdentifier() << 0;
2148         Diag(Property->getLocation(), diag::note_property_declare);
2149       }
2150       if (SetterMethod) {
2151         Diag(SetterMethod->getLocation(),
2152              diag::warn_default_atomic_custom_getter_setter)
2153           << Property->getIdentifier() << 1;
2154         Diag(Property->getLocation(), diag::note_property_declare);
2155       }
2156     }
2157
2158     // We only care about readwrite atomic property.
2159     if ((Attributes & ObjCPropertyDecl::OBJC_PR_nonatomic) ||
2160         !(Attributes & ObjCPropertyDecl::OBJC_PR_readwrite))
2161       continue;
2162     if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
2163             Property->getIdentifier(), Property->getQueryKind())) {
2164       if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
2165         continue;
2166       if (!LookedUpGetterSetter) {
2167         GetterMethod = Property->isClassProperty() ?
2168                        IMPDecl->getClassMethod(Property->getGetterName()) :
2169                        IMPDecl->getInstanceMethod(Property->getGetterName());
2170         SetterMethod = Property->isClassProperty() ?
2171                        IMPDecl->getClassMethod(Property->getSetterName()) :
2172                        IMPDecl->getInstanceMethod(Property->getSetterName());
2173       }
2174       if ((GetterMethod && !SetterMethod) || (!GetterMethod && SetterMethod)) {
2175         SourceLocation MethodLoc =
2176           (GetterMethod ? GetterMethod->getLocation()
2177                         : SetterMethod->getLocation());
2178         Diag(MethodLoc, diag::warn_atomic_property_rule)
2179           << Property->getIdentifier() << (GetterMethod != nullptr)
2180           << (SetterMethod != nullptr);
2181         // fixit stuff.
2182         if (Property->getLParenLoc().isValid() &&
2183             !(AttributesAsWritten & ObjCPropertyDecl::OBJC_PR_atomic)) {
2184           // @property () ... case.
2185           SourceLocation AfterLParen =
2186             getLocForEndOfToken(Property->getLParenLoc());
2187           StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
2188                                                       : "nonatomic";
2189           Diag(Property->getLocation(),
2190                diag::note_atomic_property_fixup_suggest)
2191             << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
2192         } else if (Property->getLParenLoc().isInvalid()) {
2193           //@property id etc.
2194           SourceLocation startLoc =
2195             Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
2196           Diag(Property->getLocation(),
2197                diag::note_atomic_property_fixup_suggest)
2198             << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
2199         }
2200         else
2201           Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
2202         Diag(Property->getLocation(), diag::note_property_declare);
2203       }
2204     }
2205   }
2206 }
2207
2208 void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
2209   if (getLangOpts().getGC() == LangOptions::GCOnly)
2210     return;
2211
2212   for (const auto *PID : D->property_impls()) {
2213     const ObjCPropertyDecl *PD = PID->getPropertyDecl();
2214     if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
2215         !PD->isClassProperty() &&
2216         !D->getInstanceMethod(PD->getGetterName())) {
2217       ObjCMethodDecl *method = PD->getGetterMethodDecl();
2218       if (!method)
2219         continue;
2220       ObjCMethodFamily family = method->getMethodFamily();
2221       if (family == OMF_alloc || family == OMF_copy ||
2222           family == OMF_mutableCopy || family == OMF_new) {
2223         if (getLangOpts().ObjCAutoRefCount)
2224           Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
2225         else
2226           Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
2227
2228         // Look for a getter explicitly declared alongside the property.
2229         // If we find one, use its location for the note.
2230         SourceLocation noteLoc = PD->getLocation();
2231         SourceLocation fixItLoc;
2232         for (auto *getterRedecl : method->redecls()) {
2233           if (getterRedecl->isImplicit())
2234             continue;
2235           if (getterRedecl->getDeclContext() != PD->getDeclContext())
2236             continue;
2237           noteLoc = getterRedecl->getLocation();
2238           fixItLoc = getterRedecl->getEndLoc();
2239         }
2240
2241         Preprocessor &PP = getPreprocessor();
2242         TokenValue tokens[] = {
2243           tok::kw___attribute, tok::l_paren, tok::l_paren,
2244           PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
2245           PP.getIdentifierInfo("none"), tok::r_paren,
2246           tok::r_paren, tok::r_paren
2247         };
2248         StringRef spelling = "__attribute__((objc_method_family(none)))";
2249         StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
2250         if (!macroName.empty())
2251           spelling = macroName;
2252
2253         auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
2254             << method->getDeclName() << spelling;
2255         if (fixItLoc.isValid()) {
2256           SmallString<64> fixItText(" ");
2257           fixItText += spelling;
2258           noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
2259         }
2260       }
2261     }
2262   }
2263 }
2264
2265 void Sema::DiagnoseMissingDesignatedInitOverrides(
2266                                             const ObjCImplementationDecl *ImplD,
2267                                             const ObjCInterfaceDecl *IFD) {
2268   assert(IFD->hasDesignatedInitializers());
2269   const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
2270   if (!SuperD)
2271     return;
2272
2273   SelectorSet InitSelSet;
2274   for (const auto *I : ImplD->instance_methods())
2275     if (I->getMethodFamily() == OMF_init)
2276       InitSelSet.insert(I->getSelector());
2277
2278   SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
2279   SuperD->getDesignatedInitializers(DesignatedInits);
2280   for (SmallVector<const ObjCMethodDecl *, 8>::iterator
2281          I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
2282     const ObjCMethodDecl *MD = *I;
2283     if (!InitSelSet.count(MD->getSelector())) {
2284       bool Ignore = false;
2285       if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
2286         Ignore = IMD->isUnavailable();
2287       }
2288       if (!Ignore) {
2289         Diag(ImplD->getLocation(),
2290              diag::warn_objc_implementation_missing_designated_init_override)
2291           << MD->getSelector();
2292         Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
2293       }
2294     }
2295   }
2296 }
2297
2298 /// AddPropertyAttrs - Propagates attributes from a property to the
2299 /// implicitly-declared getter or setter for that property.
2300 static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
2301                              ObjCPropertyDecl *Property) {
2302   // Should we just clone all attributes over?
2303   for (const auto *A : Property->attrs()) {
2304     if (isa<DeprecatedAttr>(A) ||
2305         isa<UnavailableAttr>(A) ||
2306         isa<AvailabilityAttr>(A))
2307       PropertyMethod->addAttr(A->clone(S.Context));
2308   }
2309 }
2310
2311 /// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
2312 /// have the property type and issue diagnostics if they don't.
2313 /// Also synthesize a getter/setter method if none exist (and update the
2314 /// appropriate lookup tables.
2315 void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
2316   ObjCMethodDecl *GetterMethod, *SetterMethod;
2317   ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
2318   if (CD->isInvalidDecl())
2319     return;
2320
2321   bool IsClassProperty = property->isClassProperty();
2322   GetterMethod = IsClassProperty ?
2323     CD->getClassMethod(property->getGetterName()) :
2324     CD->getInstanceMethod(property->getGetterName());
2325
2326   // if setter or getter is not found in class extension, it might be
2327   // in the primary class.
2328   if (!GetterMethod)
2329     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2330       if (CatDecl->IsClassExtension())
2331         GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2332                          getClassMethod(property->getGetterName()) :
2333                        CatDecl->getClassInterface()->
2334                          getInstanceMethod(property->getGetterName());
2335
2336   SetterMethod = IsClassProperty ?
2337                  CD->getClassMethod(property->getSetterName()) :
2338                  CD->getInstanceMethod(property->getSetterName());
2339   if (!SetterMethod)
2340     if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2341       if (CatDecl->IsClassExtension())
2342         SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2343                           getClassMethod(property->getSetterName()) :
2344                        CatDecl->getClassInterface()->
2345                           getInstanceMethod(property->getSetterName());
2346   DiagnosePropertyAccessorMismatch(property, GetterMethod,
2347                                    property->getLocation());
2348
2349   if (!property->isReadOnly() && SetterMethod) {
2350     if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
2351         Context.VoidTy)
2352       Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2353     if (SetterMethod->param_size() != 1 ||
2354         !Context.hasSameUnqualifiedType(
2355           (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2356           property->getType().getNonReferenceType())) {
2357       Diag(property->getLocation(),
2358            diag::warn_accessor_property_type_mismatch)
2359         << property->getDeclName()
2360         << SetterMethod->getSelector();
2361       Diag(SetterMethod->getLocation(), diag::note_declared_at);
2362     }
2363   }
2364
2365   // Synthesize getter/setter methods if none exist.
2366   // Find the default getter and if one not found, add one.
2367   // FIXME: The synthesized property we set here is misleading. We almost always
2368   // synthesize these methods unless the user explicitly provided prototypes
2369   // (which is odd, but allowed). Sema should be typechecking that the
2370   // declarations jive in that situation (which it is not currently).
2371   if (!GetterMethod) {
2372     // No instance/class method of same name as property getter name was found.
2373     // Declare a getter method and add it to the list of methods
2374     // for this class.
2375     SourceLocation Loc = property->getLocation();
2376
2377     // The getter returns the declared property type with all qualifiers
2378     // removed.
2379     QualType resultTy = property->getType().getAtomicUnqualifiedType();
2380
2381     // If the property is null_resettable, the getter returns nonnull.
2382     if (property->getPropertyAttributes() &
2383         ObjCPropertyDecl::OBJC_PR_null_resettable) {
2384       QualType modifiedTy = resultTy;
2385       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
2386         if (*nullability == NullabilityKind::Unspecified)
2387           resultTy = Context.getAttributedType(attr::TypeNonNull,
2388                                                modifiedTy, modifiedTy);
2389       }
2390     }
2391
2392     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
2393                              property->getGetterName(),
2394                              resultTy, nullptr, CD,
2395                              !IsClassProperty, /*isVariadic=*/false,
2396                              /*isPropertyAccessor=*/true,
2397                              /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2398                              (property->getPropertyImplementation() ==
2399                               ObjCPropertyDecl::Optional) ?
2400                              ObjCMethodDecl::Optional :
2401                              ObjCMethodDecl::Required);
2402     CD->addDecl(GetterMethod);
2403
2404     AddPropertyAttrs(*this, GetterMethod, property);
2405
2406     if (property->hasAttr<NSReturnsNotRetainedAttr>())
2407       GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2408                                                                      Loc));
2409
2410     if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2411       GetterMethod->addAttr(
2412         ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2413
2414     if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2415       GetterMethod->addAttr(
2416           SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2417                                       SA->getName(), Loc));
2418
2419     if (getLangOpts().ObjCAutoRefCount)
2420       CheckARCMethodDecl(GetterMethod);
2421   } else
2422     // A user declared getter will be synthesize when @synthesize of
2423     // the property with the same name is seen in the @implementation
2424     GetterMethod->setPropertyAccessor(true);
2425   property->setGetterMethodDecl(GetterMethod);
2426
2427   // Skip setter if property is read-only.
2428   if (!property->isReadOnly()) {
2429     // Find the default setter and if one not found, add one.
2430     if (!SetterMethod) {
2431       // No instance/class method of same name as property setter name was
2432       // found.
2433       // Declare a setter method and add it to the list of methods
2434       // for this class.
2435       SourceLocation Loc = property->getLocation();
2436
2437       SetterMethod =
2438         ObjCMethodDecl::Create(Context, Loc, Loc,
2439                                property->getSetterName(), Context.VoidTy,
2440                                nullptr, CD, !IsClassProperty,
2441                                /*isVariadic=*/false,
2442                                /*isPropertyAccessor=*/true,
2443                                /*isImplicitlyDeclared=*/true,
2444                                /*isDefined=*/false,
2445                                (property->getPropertyImplementation() ==
2446                                 ObjCPropertyDecl::Optional) ?
2447                                 ObjCMethodDecl::Optional :
2448                                 ObjCMethodDecl::Required);
2449
2450       // Remove all qualifiers from the setter's parameter type.
2451       QualType paramTy =
2452           property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
2453
2454       // If the property is null_resettable, the setter accepts a
2455       // nullable value.
2456       if (property->getPropertyAttributes() &
2457           ObjCPropertyDecl::OBJC_PR_null_resettable) {
2458         QualType modifiedTy = paramTy;
2459         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2460           if (*nullability == NullabilityKind::Unspecified)
2461             paramTy = Context.getAttributedType(attr::TypeNullable,
2462                                                 modifiedTy, modifiedTy);
2463         }
2464       }
2465
2466       // Invent the arguments for the setter. We don't bother making a
2467       // nice name for the argument.
2468       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2469                                                   Loc, Loc,
2470                                                   property->getIdentifier(),
2471                                                   paramTy,
2472                                                   /*TInfo=*/nullptr,
2473                                                   SC_None,
2474                                                   nullptr);
2475       SetterMethod->setMethodParams(Context, Argument, None);
2476
2477       AddPropertyAttrs(*this, SetterMethod, property);
2478
2479       CD->addDecl(SetterMethod);
2480       if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2481         SetterMethod->addAttr(
2482             SectionAttr::CreateImplicit(Context, SectionAttr::GNU_section,
2483                                         SA->getName(), Loc));
2484       // It's possible for the user to have set a very odd custom
2485       // setter selector that causes it to have a method family.
2486       if (getLangOpts().ObjCAutoRefCount)
2487         CheckARCMethodDecl(SetterMethod);
2488     } else
2489       // A user declared setter will be synthesize when @synthesize of
2490       // the property with the same name is seen in the @implementation
2491       SetterMethod->setPropertyAccessor(true);
2492     property->setSetterMethodDecl(SetterMethod);
2493   }
2494   // Add any synthesized methods to the global pool. This allows us to
2495   // handle the following, which is supported by GCC (and part of the design).
2496   //
2497   // @interface Foo
2498   // @property double bar;
2499   // @end
2500   //
2501   // void thisIsUnfortunate() {
2502   //   id foo;
2503   //   double bar = [foo bar];
2504   // }
2505   //
2506   if (!IsClassProperty) {
2507     if (GetterMethod)
2508       AddInstanceMethodToGlobalPool(GetterMethod);
2509     if (SetterMethod)
2510       AddInstanceMethodToGlobalPool(SetterMethod);
2511   } else {
2512     if (GetterMethod)
2513       AddFactoryMethodToGlobalPool(GetterMethod);
2514     if (SetterMethod)
2515       AddFactoryMethodToGlobalPool(SetterMethod);
2516   }
2517
2518   ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2519   if (!CurrentClass) {
2520     if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2521       CurrentClass = Cat->getClassInterface();
2522     else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2523       CurrentClass = Impl->getClassInterface();
2524   }
2525   if (GetterMethod)
2526     CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2527   if (SetterMethod)
2528     CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2529 }
2530
2531 void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2532                                        SourceLocation Loc,
2533                                        unsigned &Attributes,
2534                                        bool propertyInPrimaryClass) {
2535   // FIXME: Improve the reported location.
2536   if (!PDecl || PDecl->isInvalidDecl())
2537     return;
2538
2539   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2540       (Attributes & ObjCDeclSpec::DQ_PR_readwrite))
2541     Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2542     << "readonly" << "readwrite";
2543
2544   ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2545   QualType PropertyTy = PropertyDecl->getType();
2546
2547   // Check for copy or retain on non-object types.
2548   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |
2549                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong)) &&
2550       !PropertyTy->isObjCRetainableType() &&
2551       !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2552     Diag(Loc, diag::err_objc_property_requires_object)
2553       << (Attributes & ObjCDeclSpec::DQ_PR_weak ? "weak" :
2554           Attributes & ObjCDeclSpec::DQ_PR_copy ? "copy" : "retain (or strong)");
2555     Attributes &= ~(ObjCDeclSpec::DQ_PR_weak   | ObjCDeclSpec::DQ_PR_copy |
2556                     ObjCDeclSpec::DQ_PR_retain | ObjCDeclSpec::DQ_PR_strong);
2557     PropertyDecl->setInvalidDecl();
2558   }
2559
2560   // Check for assign on object types.
2561   if ((Attributes & ObjCDeclSpec::DQ_PR_assign) &&
2562       !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
2563       PropertyTy->isObjCRetainableType() &&
2564       !PropertyTy->isObjCARCImplicitlyUnretainedType()) {
2565     Diag(Loc, diag::warn_objc_property_assign_on_object);
2566   }
2567
2568   // Check for more than one of { assign, copy, retain }.
2569   if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
2570     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2571       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2572         << "assign" << "copy";
2573       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2574     }
2575     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2576       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2577         << "assign" << "retain";
2578       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2579     }
2580     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2581       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2582         << "assign" << "strong";
2583       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2584     }
2585     if (getLangOpts().ObjCAutoRefCount  &&
2586         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2587       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2588         << "assign" << "weak";
2589       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2590     }
2591     if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2592       Diag(Loc, diag::warn_iboutletcollection_property_assign);
2593   } else if (Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) {
2594     if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2595       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2596         << "unsafe_unretained" << "copy";
2597       Attributes &= ~ObjCDeclSpec::DQ_PR_copy;
2598     }
2599     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2600       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2601         << "unsafe_unretained" << "retain";
2602       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2603     }
2604     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2605       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2606         << "unsafe_unretained" << "strong";
2607       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2608     }
2609     if (getLangOpts().ObjCAutoRefCount  &&
2610         (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2611       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2612         << "unsafe_unretained" << "weak";
2613       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2614     }
2615   } else if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
2616     if (Attributes & ObjCDeclSpec::DQ_PR_retain) {
2617       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2618         << "copy" << "retain";
2619       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2620     }
2621     if (Attributes & ObjCDeclSpec::DQ_PR_strong) {
2622       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2623         << "copy" << "strong";
2624       Attributes &= ~ObjCDeclSpec::DQ_PR_strong;
2625     }
2626     if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2627       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2628         << "copy" << "weak";
2629       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2630     }
2631   }
2632   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2633            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2634       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2635         << "retain" << "weak";
2636       Attributes &= ~ObjCDeclSpec::DQ_PR_retain;
2637   }
2638   else if ((Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2639            (Attributes & ObjCDeclSpec::DQ_PR_weak)) {
2640       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2641         << "strong" << "weak";
2642       Attributes &= ~ObjCDeclSpec::DQ_PR_weak;
2643   }
2644
2645   if (Attributes & ObjCDeclSpec::DQ_PR_weak) {
2646     // 'weak' and 'nonnull' are mutually exclusive.
2647     if (auto nullability = PropertyTy->getNullability(Context)) {
2648       if (*nullability == NullabilityKind::NonNull)
2649         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2650           << "nonnull" << "weak";
2651     }
2652   }
2653
2654   if ((Attributes & ObjCDeclSpec::DQ_PR_atomic) &&
2655       (Attributes & ObjCDeclSpec::DQ_PR_nonatomic)) {
2656       Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2657         << "atomic" << "nonatomic";
2658       Attributes &= ~ObjCDeclSpec::DQ_PR_atomic;
2659   }
2660
2661   // Warn if user supplied no assignment attribute, property is
2662   // readwrite, and this is an object type.
2663   if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
2664     if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
2665       // do nothing
2666     } else if (getLangOpts().ObjCAutoRefCount) {
2667       // With arc, @property definitions should default to strong when
2668       // not specified.
2669       PropertyDecl->setPropertyAttributes(ObjCPropertyDecl::OBJC_PR_strong);
2670     } else if (PropertyTy->isObjCObjectPointerType()) {
2671         bool isAnyClassTy =
2672           (PropertyTy->isObjCClassType() ||
2673            PropertyTy->isObjCQualifiedClassType());
2674         // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2675         // issue any warning.
2676         if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2677           ;
2678         else if (propertyInPrimaryClass) {
2679           // Don't issue warning on property with no life time in class
2680           // extension as it is inherited from property in primary class.
2681           // Skip this warning in gc-only mode.
2682           if (getLangOpts().getGC() != LangOptions::GCOnly)
2683             Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2684
2685           // If non-gc code warn that this is likely inappropriate.
2686           if (getLangOpts().getGC() == LangOptions::NonGC)
2687             Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2688         }
2689     }
2690
2691     // FIXME: Implement warning dependent on NSCopying being
2692     // implemented. See also:
2693     // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2694     // (please trim this list while you are at it).
2695   }
2696
2697   if (!(Attributes & ObjCDeclSpec::DQ_PR_copy)
2698       &&!(Attributes & ObjCDeclSpec::DQ_PR_readonly)
2699       && getLangOpts().getGC() == LangOptions::GCOnly
2700       && PropertyTy->isBlockPointerType())
2701     Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2702   else if ((Attributes & ObjCDeclSpec::DQ_PR_retain) &&
2703            !(Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2704            !(Attributes & ObjCDeclSpec::DQ_PR_strong) &&
2705            PropertyTy->isBlockPointerType())
2706       Diag(Loc, diag::warn_objc_property_retain_of_block);
2707
2708   if ((Attributes & ObjCDeclSpec::DQ_PR_readonly) &&
2709       (Attributes & ObjCDeclSpec::DQ_PR_setter))
2710     Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2711 }