1//===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file implements semantic analysis for Objective C @property and
10//  @synthesize declarations.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/SemaInternal.h"
15#include "clang/AST/ASTMutationListener.h"
16#include "clang/AST/DeclObjC.h"
17#include "clang/AST/ExprCXX.h"
18#include "clang/AST/ExprObjC.h"
19#include "clang/Basic/SourceManager.h"
20#include "clang/Lex/Lexer.h"
21#include "clang/Lex/Preprocessor.h"
22#include "clang/Sema/Initialization.h"
23#include "llvm/ADT/DenseSet.h"
24#include "llvm/ADT/SmallString.h"
25
26using namespace clang;
27
28//===----------------------------------------------------------------------===//
29// Grammar actions.
30//===----------------------------------------------------------------------===//
31
32/// getImpliedARCOwnership - Given a set of property attributes and a
33/// type, infer an expected lifetime.  The type's ownership qualification
34/// is not considered.
35///
36/// Returns OCL_None if the attributes as stated do not imply an ownership.
37/// Never returns OCL_Autoreleasing.
38static Qualifiers::ObjCLifetime
39getImpliedARCOwnership(ObjCPropertyAttribute::Kind attrs, QualType type) {
40  // retain, strong, copy, weak, and unsafe_unretained are only legal
41  // on properties of retainable pointer type.
42  if (attrs &
43      (ObjCPropertyAttribute::kind_retain | ObjCPropertyAttribute::kind_strong |
44       ObjCPropertyAttribute::kind_copy)) {
45    return Qualifiers::OCL_Strong;
46  } else if (attrs & ObjCPropertyAttribute::kind_weak) {
47    return Qualifiers::OCL_Weak;
48  } else if (attrs & ObjCPropertyAttribute::kind_unsafe_unretained) {
49    return Qualifiers::OCL_ExplicitNone;
50  }
51
52  // assign can appear on other types, so we have to check the
53  // property type.
54  if (attrs & ObjCPropertyAttribute::kind_assign &&
55      type->isObjCRetainableType()) {
56    return Qualifiers::OCL_ExplicitNone;
57  }
58
59  return Qualifiers::OCL_None;
60}
61
62/// Check the internal consistency of a property declaration with
63/// an explicit ownership qualifier.
64static void checkPropertyDeclWithOwnership(Sema &S,
65                                           ObjCPropertyDecl *property) {
66  if (property->isInvalidDecl()) return;
67
68  ObjCPropertyAttribute::Kind propertyKind = property->getPropertyAttributes();
69  Qualifiers::ObjCLifetime propertyLifetime
70    = property->getType().getObjCLifetime();
71
72  assert(propertyLifetime != Qualifiers::OCL_None);
73
74  Qualifiers::ObjCLifetime expectedLifetime
75    = getImpliedARCOwnership(propertyKind, property->getType());
76  if (!expectedLifetime) {
77    // We have a lifetime qualifier but no dominating property
78    // attribute.  That's okay, but restore reasonable invariants by
79    // setting the property attribute according to the lifetime
80    // qualifier.
81    ObjCPropertyAttribute::Kind attr;
82    if (propertyLifetime == Qualifiers::OCL_Strong) {
83      attr = ObjCPropertyAttribute::kind_strong;
84    } else if (propertyLifetime == Qualifiers::OCL_Weak) {
85      attr = ObjCPropertyAttribute::kind_weak;
86    } else {
87      assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
88      attr = ObjCPropertyAttribute::kind_unsafe_unretained;
89    }
90    property->setPropertyAttributes(attr);
91    return;
92  }
93
94  if (propertyLifetime == expectedLifetime) return;
95
96  property->setInvalidDecl();
97  S.Diag(property->getLocation(),
98         diag::err_arc_inconsistent_property_ownership)
99    << property->getDeclName()
100    << expectedLifetime
101    << propertyLifetime;
102}
103
104/// Check this Objective-C property against a property declared in the
105/// given protocol.
106static void
107CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
108                             ObjCProtocolDecl *Proto,
109                             llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
110  // Have we seen this protocol before?
111  if (!Known.insert(Proto).second)
112    return;
113
114  // Look for a property with the same name.
115  if (ObjCPropertyDecl *ProtoProp = Proto->getProperty(
116          Prop->getIdentifier(), Prop->isInstanceProperty())) {
117    S.DiagnosePropertyMismatch(Prop, ProtoProp, Proto->getIdentifier(), true);
118    return;
119  }
120
121  // Check this property against any protocols we inherit.
122  for (auto *P : Proto->protocols())
123    CheckPropertyAgainstProtocol(S, Prop, P, Known);
124}
125
126static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
127  // In GC mode, just look for the __weak qualifier.
128  if (S.getLangOpts().getGC() != LangOptions::NonGC) {
129    if (T.isObjCGCWeak())
130      return ObjCPropertyAttribute::kind_weak;
131
132    // In ARC/MRC, look for an explicit ownership qualifier.
133    // For some reason, this only applies to __weak.
134  } else if (auto ownership = T.getObjCLifetime()) {
135    switch (ownership) {
136    case Qualifiers::OCL_Weak:
137      return ObjCPropertyAttribute::kind_weak;
138    case Qualifiers::OCL_Strong:
139      return ObjCPropertyAttribute::kind_strong;
140    case Qualifiers::OCL_ExplicitNone:
141      return ObjCPropertyAttribute::kind_unsafe_unretained;
142    case Qualifiers::OCL_Autoreleasing:
143    case Qualifiers::OCL_None:
144      return 0;
145    }
146    llvm_unreachable("bad qualifier");
147  }
148
149  return 0;
150}
151
152static const unsigned OwnershipMask =
153    (ObjCPropertyAttribute::kind_assign | ObjCPropertyAttribute::kind_retain |
154     ObjCPropertyAttribute::kind_copy | ObjCPropertyAttribute::kind_weak |
155     ObjCPropertyAttribute::kind_strong |
156     ObjCPropertyAttribute::kind_unsafe_unretained);
157
158static unsigned getOwnershipRule(unsigned attr) {
159  unsigned result = attr & OwnershipMask;
160
161  // From an ownership perspective, assign and unsafe_unretained are
162  // identical; make sure one also implies the other.
163  if (result & (ObjCPropertyAttribute::kind_assign |
164                ObjCPropertyAttribute::kind_unsafe_unretained)) {
165    result |= ObjCPropertyAttribute::kind_assign |
166              ObjCPropertyAttribute::kind_unsafe_unretained;
167  }
168
169  return result;
170}
171
172Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
173                          SourceLocation LParenLoc,
174                          FieldDeclarator &FD,
175                          ObjCDeclSpec &ODS,
176                          Selector GetterSel,
177                          Selector SetterSel,
178                          tok::ObjCKeywordKind MethodImplKind,
179                          DeclContext *lexicalDC) {
180  unsigned Attributes = ODS.getPropertyAttributes();
181  FD.D.setObjCWeakProperty((Attributes & ObjCPropertyAttribute::kind_weak) !=
182                           0);
183  TypeSourceInfo *TSI = GetTypeForDeclarator(FD.D, S);
184  QualType T = TSI->getType();
185  if (!getOwnershipRule(Attributes)) {
186    Attributes |= deducePropertyOwnershipFromType(*this, T);
187  }
188  bool isReadWrite = ((Attributes & ObjCPropertyAttribute::kind_readwrite) ||
189                      // default is readwrite!
190                      !(Attributes & ObjCPropertyAttribute::kind_readonly));
191
192  // Proceed with constructing the ObjCPropertyDecls.
193  ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
194  ObjCPropertyDecl *Res = nullptr;
195  if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
196    if (CDecl->IsClassExtension()) {
197      Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
198                                           FD,
199                                           GetterSel, ODS.getGetterNameLoc(),
200                                           SetterSel, ODS.getSetterNameLoc(),
201                                           isReadWrite, Attributes,
202                                           ODS.getPropertyAttributes(),
203                                           T, TSI, MethodImplKind);
204      if (!Res)
205        return nullptr;
206    }
207  }
208
209  if (!Res) {
210    Res = CreatePropertyDecl(S, ClassDecl, AtLoc, LParenLoc, FD,
211                             GetterSel, ODS.getGetterNameLoc(), SetterSel,
212                             ODS.getSetterNameLoc(), isReadWrite, Attributes,
213                             ODS.getPropertyAttributes(), T, TSI,
214                             MethodImplKind);
215    if (lexicalDC)
216      Res->setLexicalDeclContext(lexicalDC);
217  }
218
219  // Validate the attributes on the @property.
220  CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
221                              (isa<ObjCInterfaceDecl>(ClassDecl) ||
222                               isa<ObjCProtocolDecl>(ClassDecl)));
223
224  // Check consistency if the type has explicit ownership qualification.
225  if (Res->getType().getObjCLifetime())
226    checkPropertyDeclWithOwnership(*this, Res);
227
228  llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
229  if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
230    // For a class, compare the property against a property in our superclass.
231    bool FoundInSuper = false;
232    ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
233    while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
234      if (ObjCPropertyDecl *SuperProp = Super->getProperty(
235              Res->getIdentifier(), Res->isInstanceProperty())) {
236        DiagnosePropertyMismatch(Res, SuperProp, Super->getIdentifier(), false);
237        FoundInSuper = true;
238        break;
239      }
240      CurrentInterfaceDecl = Super;
241    }
242
243    if (FoundInSuper) {
244      // Also compare the property against a property in our protocols.
245      for (auto *P : CurrentInterfaceDecl->protocols()) {
246        CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
247      }
248    } else {
249      // Slower path: look in all protocols we referenced.
250      for (auto *P : IFace->all_referenced_protocols()) {
251        CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
252      }
253    }
254  } else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
255    // We don't check if class extension. Because properties in class extension
256    // are meant to override some of the attributes and checking has already done
257    // when property in class extension is constructed.
258    if (!Cat->IsClassExtension())
259      for (auto *P : Cat->protocols())
260        CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
261  } else {
262    ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(ClassDecl);
263    for (auto *P : Proto->protocols())
264      CheckPropertyAgainstProtocol(*this, Res, P, KnownProtos);
265  }
266
267  ActOnDocumentableDecl(Res);
268  return Res;
269}
270
271static ObjCPropertyAttribute::Kind
272makePropertyAttributesAsWritten(unsigned Attributes) {
273  unsigned attributesAsWritten = 0;
274  if (Attributes & ObjCPropertyAttribute::kind_readonly)
275    attributesAsWritten |= ObjCPropertyAttribute::kind_readonly;
276  if (Attributes & ObjCPropertyAttribute::kind_readwrite)
277    attributesAsWritten |= ObjCPropertyAttribute::kind_readwrite;
278  if (Attributes & ObjCPropertyAttribute::kind_getter)
279    attributesAsWritten |= ObjCPropertyAttribute::kind_getter;
280  if (Attributes & ObjCPropertyAttribute::kind_setter)
281    attributesAsWritten |= ObjCPropertyAttribute::kind_setter;
282  if (Attributes & ObjCPropertyAttribute::kind_assign)
283    attributesAsWritten |= ObjCPropertyAttribute::kind_assign;
284  if (Attributes & ObjCPropertyAttribute::kind_retain)
285    attributesAsWritten |= ObjCPropertyAttribute::kind_retain;
286  if (Attributes & ObjCPropertyAttribute::kind_strong)
287    attributesAsWritten |= ObjCPropertyAttribute::kind_strong;
288  if (Attributes & ObjCPropertyAttribute::kind_weak)
289    attributesAsWritten |= ObjCPropertyAttribute::kind_weak;
290  if (Attributes & ObjCPropertyAttribute::kind_copy)
291    attributesAsWritten |= ObjCPropertyAttribute::kind_copy;
292  if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
293    attributesAsWritten |= ObjCPropertyAttribute::kind_unsafe_unretained;
294  if (Attributes & ObjCPropertyAttribute::kind_nonatomic)
295    attributesAsWritten |= ObjCPropertyAttribute::kind_nonatomic;
296  if (Attributes & ObjCPropertyAttribute::kind_atomic)
297    attributesAsWritten |= ObjCPropertyAttribute::kind_atomic;
298  if (Attributes & ObjCPropertyAttribute::kind_class)
299    attributesAsWritten |= ObjCPropertyAttribute::kind_class;
300  if (Attributes & ObjCPropertyAttribute::kind_direct)
301    attributesAsWritten |= ObjCPropertyAttribute::kind_direct;
302
303  return (ObjCPropertyAttribute::Kind)attributesAsWritten;
304}
305
306static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
307                                 SourceLocation LParenLoc, SourceLocation &Loc) {
308  if (LParenLoc.isMacroID())
309    return false;
310
311  SourceManager &SM = Context.getSourceManager();
312  std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(LParenLoc);
313  // Try to load the file buffer.
314  bool invalidTemp = false;
315  StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
316  if (invalidTemp)
317    return false;
318  const char *tokenBegin = file.data() + locInfo.second;
319
320  // Lex from the start of the given location.
321  Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
322              Context.getLangOpts(),
323              file.begin(), tokenBegin, file.end());
324  Token Tok;
325  do {
326    lexer.LexFromRawLexer(Tok);
327    if (Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
328      Loc = Tok.getLocation();
329      return true;
330    }
331  } while (Tok.isNot(tok::r_paren));
332  return false;
333}
334
335/// Check for a mismatch in the atomicity of the given properties.
336static void checkAtomicPropertyMismatch(Sema &S,
337                                        ObjCPropertyDecl *OldProperty,
338                                        ObjCPropertyDecl *NewProperty,
339                                        bool PropagateAtomicity) {
340  // If the atomicity of both matches, we're done.
341  bool OldIsAtomic = (OldProperty->getPropertyAttributes() &
342                      ObjCPropertyAttribute::kind_nonatomic) == 0;
343  bool NewIsAtomic = (NewProperty->getPropertyAttributes() &
344                      ObjCPropertyAttribute::kind_nonatomic) == 0;
345  if (OldIsAtomic == NewIsAtomic) return;
346
347  // Determine whether the given property is readonly and implicitly
348  // atomic.
349  auto isImplicitlyReadonlyAtomic = [](ObjCPropertyDecl *Property) -> bool {
350    // Is it readonly?
351    auto Attrs = Property->getPropertyAttributes();
352    if ((Attrs & ObjCPropertyAttribute::kind_readonly) == 0)
353      return false;
354
355    // Is it nonatomic?
356    if (Attrs & ObjCPropertyAttribute::kind_nonatomic)
357      return false;
358
359    // Was 'atomic' specified directly?
360    if (Property->getPropertyAttributesAsWritten() &
361        ObjCPropertyAttribute::kind_atomic)
362      return false;
363
364    return true;
365  };
366
367  // If we're allowed to propagate atomicity, and the new property did
368  // not specify atomicity at all, propagate.
369  const unsigned AtomicityMask = (ObjCPropertyAttribute::kind_atomic |
370                                  ObjCPropertyAttribute::kind_nonatomic);
371  if (PropagateAtomicity &&
372      ((NewProperty->getPropertyAttributesAsWritten() & AtomicityMask) == 0)) {
373    unsigned Attrs = NewProperty->getPropertyAttributes();
374    Attrs = Attrs & ~AtomicityMask;
375    if (OldIsAtomic)
376      Attrs |= ObjCPropertyAttribute::kind_atomic;
377    else
378      Attrs |= ObjCPropertyAttribute::kind_nonatomic;
379
380    NewProperty->overwritePropertyAttributes(Attrs);
381    return;
382  }
383
384  // One of the properties is atomic; if it's a readonly property, and
385  // 'atomic' wasn't explicitly specified, we're okay.
386  if ((OldIsAtomic && isImplicitlyReadonlyAtomic(OldProperty)) ||
387      (NewIsAtomic && isImplicitlyReadonlyAtomic(NewProperty)))
388    return;
389
390  // Diagnose the conflict.
391  const IdentifierInfo *OldContextName;
392  auto *OldDC = OldProperty->getDeclContext();
393  if (auto Category = dyn_cast<ObjCCategoryDecl>(OldDC))
394    OldContextName = Category->getClassInterface()->getIdentifier();
395  else
396    OldContextName = cast<ObjCContainerDecl>(OldDC)->getIdentifier();
397
398  S.Diag(NewProperty->getLocation(), diag::warn_property_attribute)
399    << NewProperty->getDeclName() << "atomic"
400    << OldContextName;
401  S.Diag(OldProperty->getLocation(), diag::note_property_declare);
402}
403
404ObjCPropertyDecl *
405Sema::HandlePropertyInClassExtension(Scope *S,
406                                     SourceLocation AtLoc,
407                                     SourceLocation LParenLoc,
408                                     FieldDeclarator &FD,
409                                     Selector GetterSel,
410                                     SourceLocation GetterNameLoc,
411                                     Selector SetterSel,
412                                     SourceLocation SetterNameLoc,
413                                     const bool isReadWrite,
414                                     unsigned &Attributes,
415                                     const unsigned AttributesAsWritten,
416                                     QualType T,
417                                     TypeSourceInfo *TSI,
418                                     tok::ObjCKeywordKind MethodImplKind) {
419  ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(CurContext);
420  // Diagnose if this property is already in continuation class.
421  DeclContext *DC = CurContext;
422  IdentifierInfo *PropertyId = FD.D.getIdentifier();
423  ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
424
425  // We need to look in the @interface to see if the @property was
426  // already declared.
427  if (!CCPrimary) {
428    Diag(CDecl->getLocation(), diag::err_continuation_class);
429    return nullptr;
430  }
431
432  bool isClassProperty =
433      (AttributesAsWritten & ObjCPropertyAttribute::kind_class) ||
434      (Attributes & ObjCPropertyAttribute::kind_class);
435
436  // Find the property in the extended class's primary class or
437  // extensions.
438  ObjCPropertyDecl *PIDecl = CCPrimary->FindPropertyVisibleInPrimaryClass(
439      PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty));
440
441  // If we found a property in an extension, complain.
442  if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
443    Diag(AtLoc, diag::err_duplicate_property);
444    Diag(PIDecl->getLocation(), diag::note_property_declare);
445    return nullptr;
446  }
447
448  // Check for consistency with the previous declaration, if there is one.
449  if (PIDecl) {
450    // A readonly property declared in the primary class can be refined
451    // by adding a readwrite property within an extension.
452    // Anything else is an error.
453    if (!(PIDecl->isReadOnly() && isReadWrite)) {
454      // Tailor the diagnostics for the common case where a readwrite
455      // property is declared both in the @interface and the continuation.
456      // This is a common error where the user often intended the original
457      // declaration to be readonly.
458      unsigned diag =
459          (Attributes & ObjCPropertyAttribute::kind_readwrite) &&
460                  (PIDecl->getPropertyAttributesAsWritten() &
461                   ObjCPropertyAttribute::kind_readwrite)
462              ? diag::err_use_continuation_class_redeclaration_readwrite
463              : diag::err_use_continuation_class;
464      Diag(AtLoc, diag)
465        << CCPrimary->getDeclName();
466      Diag(PIDecl->getLocation(), diag::note_property_declare);
467      return nullptr;
468    }
469
470    // Check for consistency of getters.
471    if (PIDecl->getGetterName() != GetterSel) {
472     // If the getter was written explicitly, complain.
473     if (AttributesAsWritten & ObjCPropertyAttribute::kind_getter) {
474       Diag(AtLoc, diag::warn_property_redecl_getter_mismatch)
475           << PIDecl->getGetterName() << GetterSel;
476       Diag(PIDecl->getLocation(), diag::note_property_declare);
477     }
478
479      // Always adopt the getter from the original declaration.
480      GetterSel = PIDecl->getGetterName();
481      Attributes |= ObjCPropertyAttribute::kind_getter;
482    }
483
484    // Check consistency of ownership.
485    unsigned ExistingOwnership
486      = getOwnershipRule(PIDecl->getPropertyAttributes());
487    unsigned NewOwnership = getOwnershipRule(Attributes);
488    if (ExistingOwnership && NewOwnership != ExistingOwnership) {
489      // If the ownership was written explicitly, complain.
490      if (getOwnershipRule(AttributesAsWritten)) {
491        Diag(AtLoc, diag::warn_property_attr_mismatch);
492        Diag(PIDecl->getLocation(), diag::note_property_declare);
493      }
494
495      // Take the ownership from the original property.
496      Attributes = (Attributes & ~OwnershipMask) | ExistingOwnership;
497    }
498
499    // If the redeclaration is 'weak' but the original property is not,
500    if ((Attributes & ObjCPropertyAttribute::kind_weak) &&
501        !(PIDecl->getPropertyAttributesAsWritten() &
502          ObjCPropertyAttribute::kind_weak) &&
503        PIDecl->getType()->getAs<ObjCObjectPointerType>() &&
504        PIDecl->getType().getObjCLifetime() == Qualifiers::OCL_None) {
505      Diag(AtLoc, diag::warn_property_implicitly_mismatched);
506      Diag(PIDecl->getLocation(), diag::note_property_declare);
507    }
508  }
509
510  // Create a new ObjCPropertyDecl with the DeclContext being
511  // the class extension.
512  ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
513                                               FD, GetterSel, GetterNameLoc,
514                                               SetterSel, SetterNameLoc,
515                                               isReadWrite,
516                                               Attributes, AttributesAsWritten,
517                                               T, TSI, MethodImplKind, DC);
518
519  // If there was no declaration of a property with the same name in
520  // the primary class, we're done.
521  if (!PIDecl) {
522    ProcessPropertyDecl(PDecl);
523    return PDecl;
524  }
525
526  if (!Context.hasSameType(PIDecl->getType(), PDecl->getType())) {
527    bool IncompatibleObjC = false;
528    QualType ConvertedType;
529    // Relax the strict type matching for property type in continuation class.
530    // Allow property object type of continuation class to be different as long
531    // as it narrows the object type in its primary class property. Note that
532    // this conversion is safe only because the wider type is for a 'readonly'
533    // property in primary class and 'narrowed' type for a 'readwrite' property
534    // in continuation class.
535    QualType PrimaryClassPropertyT = Context.getCanonicalType(PIDecl->getType());
536    QualType ClassExtPropertyT = Context.getCanonicalType(PDecl->getType());
537    if (!isa<ObjCObjectPointerType>(PrimaryClassPropertyT) ||
538        !isa<ObjCObjectPointerType>(ClassExtPropertyT) ||
539        (!isObjCPointerConversion(ClassExtPropertyT, PrimaryClassPropertyT,
540                                  ConvertedType, IncompatibleObjC))
541        || IncompatibleObjC) {
542      Diag(AtLoc,
543          diag::err_type_mismatch_continuation_class) << PDecl->getType();
544      Diag(PIDecl->getLocation(), diag::note_property_declare);
545      return nullptr;
546    }
547  }
548
549  // Check that atomicity of property in class extension matches the previous
550  // declaration.
551  checkAtomicPropertyMismatch(*this, PIDecl, PDecl, true);
552
553  // Make sure getter/setter are appropriately synthesized.
554  ProcessPropertyDecl(PDecl);
555  return PDecl;
556}
557
558ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
559                                           ObjCContainerDecl *CDecl,
560                                           SourceLocation AtLoc,
561                                           SourceLocation LParenLoc,
562                                           FieldDeclarator &FD,
563                                           Selector GetterSel,
564                                           SourceLocation GetterNameLoc,
565                                           Selector SetterSel,
566                                           SourceLocation SetterNameLoc,
567                                           const bool isReadWrite,
568                                           const unsigned Attributes,
569                                           const unsigned AttributesAsWritten,
570                                           QualType T,
571                                           TypeSourceInfo *TInfo,
572                                           tok::ObjCKeywordKind MethodImplKind,
573                                           DeclContext *lexicalDC){
574  IdentifierInfo *PropertyId = FD.D.getIdentifier();
575
576  // Property defaults to 'assign' if it is readwrite, unless this is ARC
577  // and the type is retainable.
578  bool isAssign;
579  if (Attributes & (ObjCPropertyAttribute::kind_assign |
580                    ObjCPropertyAttribute::kind_unsafe_unretained)) {
581    isAssign = true;
582  } else if (getOwnershipRule(Attributes) || !isReadWrite) {
583    isAssign = false;
584  } else {
585    isAssign = (!getLangOpts().ObjCAutoRefCount ||
586                !T->isObjCRetainableType());
587  }
588
589  // Issue a warning if property is 'assign' as default and its
590  // object, which is gc'able conforms to NSCopying protocol
591  if (getLangOpts().getGC() != LangOptions::NonGC && isAssign &&
592      !(Attributes & ObjCPropertyAttribute::kind_assign)) {
593    if (const ObjCObjectPointerType *ObjPtrTy =
594          T->getAs<ObjCObjectPointerType>()) {
595      ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
596      if (IDecl)
597        if (ObjCProtocolDecl* PNSCopying =
598            LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
599          if (IDecl->ClassImplementsProtocol(PNSCopying, true))
600            Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
601    }
602  }
603
604  if (T->isObjCObjectType()) {
605    SourceLocation StarLoc = TInfo->getTypeLoc().getEndLoc();
606    StarLoc = getLocForEndOfToken(StarLoc);
607    Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
608      << FixItHint::CreateInsertion(StarLoc, "*");
609    T = Context.getObjCObjectPointerType(T);
610    SourceLocation TLoc = TInfo->getTypeLoc().getBeginLoc();
611    TInfo = Context.getTrivialTypeSourceInfo(T, TLoc);
612  }
613
614  DeclContext *DC = CDecl;
615  ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(Context, DC,
616                                                     FD.D.getIdentifierLoc(),
617                                                     PropertyId, AtLoc,
618                                                     LParenLoc, T, TInfo);
619
620  bool isClassProperty =
621      (AttributesAsWritten & ObjCPropertyAttribute::kind_class) ||
622      (Attributes & ObjCPropertyAttribute::kind_class);
623  // Class property and instance property can have the same name.
624  if (ObjCPropertyDecl *prevDecl = ObjCPropertyDecl::findPropertyDecl(
625          DC, PropertyId, ObjCPropertyDecl::getQueryKind(isClassProperty))) {
626    Diag(PDecl->getLocation(), diag::err_duplicate_property);
627    Diag(prevDecl->getLocation(), diag::note_property_declare);
628    PDecl->setInvalidDecl();
629  }
630  else {
631    DC->addDecl(PDecl);
632    if (lexicalDC)
633      PDecl->setLexicalDeclContext(lexicalDC);
634  }
635
636  if (T->isArrayType() || T->isFunctionType()) {
637    Diag(AtLoc, diag::err_property_type) << T;
638    PDecl->setInvalidDecl();
639  }
640
641  ProcessDeclAttributes(S, PDecl, FD.D);
642
643  // Regardless of setter/getter attribute, we save the default getter/setter
644  // selector names in anticipation of declaration of setter/getter methods.
645  PDecl->setGetterName(GetterSel, GetterNameLoc);
646  PDecl->setSetterName(SetterSel, SetterNameLoc);
647  PDecl->setPropertyAttributesAsWritten(
648                          makePropertyAttributesAsWritten(AttributesAsWritten));
649
650  if (Attributes & ObjCPropertyAttribute::kind_readonly)
651    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_readonly);
652
653  if (Attributes & ObjCPropertyAttribute::kind_getter)
654    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_getter);
655
656  if (Attributes & ObjCPropertyAttribute::kind_setter)
657    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_setter);
658
659  if (isReadWrite)
660    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_readwrite);
661
662  if (Attributes & ObjCPropertyAttribute::kind_retain)
663    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_retain);
664
665  if (Attributes & ObjCPropertyAttribute::kind_strong)
666    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
667
668  if (Attributes & ObjCPropertyAttribute::kind_weak)
669    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_weak);
670
671  if (Attributes & ObjCPropertyAttribute::kind_copy)
672    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_copy);
673
674  if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
675    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_unsafe_unretained);
676
677  if (isAssign)
678    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_assign);
679
680  // In the semantic attributes, one of nonatomic or atomic is always set.
681  if (Attributes & ObjCPropertyAttribute::kind_nonatomic)
682    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_nonatomic);
683  else
684    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_atomic);
685
686  // 'unsafe_unretained' is alias for 'assign'.
687  if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
688    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_assign);
689  if (isAssign)
690    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_unsafe_unretained);
691
692  if (MethodImplKind == tok::objc_required)
693    PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
694  else if (MethodImplKind == tok::objc_optional)
695    PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
696
697  if (Attributes & ObjCPropertyAttribute::kind_nullability)
698    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_nullability);
699
700  if (Attributes & ObjCPropertyAttribute::kind_null_resettable)
701    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_null_resettable);
702
703  if (Attributes & ObjCPropertyAttribute::kind_class)
704    PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_class);
705
706  if ((Attributes & ObjCPropertyAttribute::kind_direct) ||
707      CDecl->hasAttr<ObjCDirectMembersAttr>()) {
708    if (isa<ObjCProtocolDecl>(CDecl)) {
709      Diag(PDecl->getLocation(), diag::err_objc_direct_on_protocol) << true;
710    } else if (getLangOpts().ObjCRuntime.allowsDirectDispatch()) {
711      PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_direct);
712    } else {
713      Diag(PDecl->getLocation(), diag::warn_objc_direct_property_ignored)
714          << PDecl->getDeclName();
715    }
716  }
717
718  return PDecl;
719}
720
721static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
722                                 ObjCPropertyDecl *property,
723                                 ObjCIvarDecl *ivar) {
724  if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
725
726  QualType ivarType = ivar->getType();
727  Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
728
729  // The lifetime implied by the property's attributes.
730  Qualifiers::ObjCLifetime propertyLifetime =
731    getImpliedARCOwnership(property->getPropertyAttributes(),
732                           property->getType());
733
734  // We're fine if they match.
735  if (propertyLifetime == ivarLifetime) return;
736
737  // None isn't a valid lifetime for an object ivar in ARC, and
738  // __autoreleasing is never valid; don't diagnose twice.
739  if ((ivarLifetime == Qualifiers::OCL_None &&
740       S.getLangOpts().ObjCAutoRefCount) ||
741      ivarLifetime == Qualifiers::OCL_Autoreleasing)
742    return;
743
744  // If the ivar is private, and it's implicitly __unsafe_unretained
745  // because of its type, then pretend it was actually implicitly
746  // __strong.  This is only sound because we're processing the
747  // property implementation before parsing any method bodies.
748  if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
749      propertyLifetime == Qualifiers::OCL_Strong &&
750      ivar->getAccessControl() == ObjCIvarDecl::Private) {
751    SplitQualType split = ivarType.split();
752    if (split.Quals.hasObjCLifetime()) {
753      assert(ivarType->isObjCARCImplicitlyUnretainedType());
754      split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
755      ivarType = S.Context.getQualifiedType(split);
756      ivar->setType(ivarType);
757      return;
758    }
759  }
760
761  switch (propertyLifetime) {
762  case Qualifiers::OCL_Strong:
763    S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
764      << property->getDeclName()
765      << ivar->getDeclName()
766      << ivarLifetime;
767    break;
768
769  case Qualifiers::OCL_Weak:
770    S.Diag(ivar->getLocation(), diag::err_weak_property)
771      << property->getDeclName()
772      << ivar->getDeclName();
773    break;
774
775  case Qualifiers::OCL_ExplicitNone:
776    S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
777        << property->getDeclName() << ivar->getDeclName()
778        << ((property->getPropertyAttributesAsWritten() &
779             ObjCPropertyAttribute::kind_assign) != 0);
780    break;
781
782  case Qualifiers::OCL_Autoreleasing:
783    llvm_unreachable("properties cannot be autoreleasing");
784
785  case Qualifiers::OCL_None:
786    // Any other property should be ignored.
787    return;
788  }
789
790  S.Diag(property->getLocation(), diag::note_property_declare);
791  if (propertyImplLoc.isValid())
792    S.Diag(propertyImplLoc, diag::note_property_synthesize);
793}
794
795/// setImpliedPropertyAttributeForReadOnlyProperty -
796/// This routine evaludates life-time attributes for a 'readonly'
797/// property with no known lifetime of its own, using backing
798/// 'ivar's attribute, if any. If no backing 'ivar', property's
799/// life-time is assumed 'strong'.
800static void setImpliedPropertyAttributeForReadOnlyProperty(
801              ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
802  Qualifiers::ObjCLifetime propertyLifetime =
803    getImpliedARCOwnership(property->getPropertyAttributes(),
804                           property->getType());
805  if (propertyLifetime != Qualifiers::OCL_None)
806    return;
807
808  if (!ivar) {
809    // if no backing ivar, make property 'strong'.
810    property->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
811    return;
812  }
813  // property assumes owenership of backing ivar.
814  QualType ivarType = ivar->getType();
815  Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
816  if (ivarLifetime == Qualifiers::OCL_Strong)
817    property->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
818  else if (ivarLifetime == Qualifiers::OCL_Weak)
819    property->setPropertyAttributes(ObjCPropertyAttribute::kind_weak);
820}
821
822static bool isIncompatiblePropertyAttribute(unsigned Attr1, unsigned Attr2,
823                                            ObjCPropertyAttribute::Kind Kind) {
824  return (Attr1 & Kind) != (Attr2 & Kind);
825}
826
827static bool areIncompatiblePropertyAttributes(unsigned Attr1, unsigned Attr2,
828                                              unsigned Kinds) {
829  return ((Attr1 & Kinds) != 0) != ((Attr2 & Kinds) != 0);
830}
831
832/// SelectPropertyForSynthesisFromProtocols - Finds the most appropriate
833/// property declaration that should be synthesised in all of the inherited
834/// protocols. It also diagnoses properties declared in inherited protocols with
835/// mismatched types or attributes, since any of them can be candidate for
836/// synthesis.
837static ObjCPropertyDecl *
838SelectPropertyForSynthesisFromProtocols(Sema &S, SourceLocation AtLoc,
839                                        ObjCInterfaceDecl *ClassDecl,
840                                        ObjCPropertyDecl *Property) {
841  assert(isa<ObjCProtocolDecl>(Property->getDeclContext()) &&
842         "Expected a property from a protocol");
843  ObjCInterfaceDecl::ProtocolPropertySet ProtocolSet;
844  ObjCInterfaceDecl::PropertyDeclOrder Properties;
845  for (const auto *PI : ClassDecl->all_referenced_protocols()) {
846    if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
847      PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
848                                                Properties);
849  }
850  if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass()) {
851    while (SDecl) {
852      for (const auto *PI : SDecl->all_referenced_protocols()) {
853        if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
854          PDecl->collectInheritedProtocolProperties(Property, ProtocolSet,
855                                                    Properties);
856      }
857      SDecl = SDecl->getSuperClass();
858    }
859  }
860
861  if (Properties.empty())
862    return Property;
863
864  ObjCPropertyDecl *OriginalProperty = Property;
865  size_t SelectedIndex = 0;
866  for (const auto &Prop : llvm::enumerate(Properties)) {
867    // Select the 'readwrite' property if such property exists.
868    if (Property->isReadOnly() && !Prop.value()->isReadOnly()) {
869      Property = Prop.value();
870      SelectedIndex = Prop.index();
871    }
872  }
873  if (Property != OriginalProperty) {
874    // Check that the old property is compatible with the new one.
875    Properties[SelectedIndex] = OriginalProperty;
876  }
877
878  QualType RHSType = S.Context.getCanonicalType(Property->getType());
879  unsigned OriginalAttributes = Property->getPropertyAttributesAsWritten();
880  enum MismatchKind {
881    IncompatibleType = 0,
882    HasNoExpectedAttribute,
883    HasUnexpectedAttribute,
884    DifferentGetter,
885    DifferentSetter
886  };
887  // Represents a property from another protocol that conflicts with the
888  // selected declaration.
889  struct MismatchingProperty {
890    const ObjCPropertyDecl *Prop;
891    MismatchKind Kind;
892    StringRef AttributeName;
893  };
894  SmallVector<MismatchingProperty, 4> Mismatches;
895  for (ObjCPropertyDecl *Prop : Properties) {
896    // Verify the property attributes.
897    unsigned Attr = Prop->getPropertyAttributesAsWritten();
898    if (Attr != OriginalAttributes) {
899      auto Diag = [&](bool OriginalHasAttribute, StringRef AttributeName) {
900        MismatchKind Kind = OriginalHasAttribute ? HasNoExpectedAttribute
901                                                 : HasUnexpectedAttribute;
902        Mismatches.push_back({Prop, Kind, AttributeName});
903      };
904      // The ownership might be incompatible unless the property has no explicit
905      // ownership.
906      bool HasOwnership =
907          (Attr & (ObjCPropertyAttribute::kind_retain |
908                   ObjCPropertyAttribute::kind_strong |
909                   ObjCPropertyAttribute::kind_copy |
910                   ObjCPropertyAttribute::kind_assign |
911                   ObjCPropertyAttribute::kind_unsafe_unretained |
912                   ObjCPropertyAttribute::kind_weak)) != 0;
913      if (HasOwnership &&
914          isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
915                                          ObjCPropertyAttribute::kind_copy)) {
916        Diag(OriginalAttributes & ObjCPropertyAttribute::kind_copy, "copy");
917        continue;
918      }
919      if (HasOwnership && areIncompatiblePropertyAttributes(
920                              OriginalAttributes, Attr,
921                              ObjCPropertyAttribute::kind_retain |
922                                  ObjCPropertyAttribute::kind_strong)) {
923        Diag(OriginalAttributes & (ObjCPropertyAttribute::kind_retain |
924                                   ObjCPropertyAttribute::kind_strong),
925             "retain (or strong)");
926        continue;
927      }
928      if (isIncompatiblePropertyAttribute(OriginalAttributes, Attr,
929                                          ObjCPropertyAttribute::kind_atomic)) {
930        Diag(OriginalAttributes & ObjCPropertyAttribute::kind_atomic, "atomic");
931        continue;
932      }
933    }
934    if (Property->getGetterName() != Prop->getGetterName()) {
935      Mismatches.push_back({Prop, DifferentGetter, ""});
936      continue;
937    }
938    if (!Property->isReadOnly() && !Prop->isReadOnly() &&
939        Property->getSetterName() != Prop->getSetterName()) {
940      Mismatches.push_back({Prop, DifferentSetter, ""});
941      continue;
942    }
943    QualType LHSType = S.Context.getCanonicalType(Prop->getType());
944    if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
945      bool IncompatibleObjC = false;
946      QualType ConvertedType;
947      if (!S.isObjCPointerConversion(RHSType, LHSType, ConvertedType, IncompatibleObjC)
948          || IncompatibleObjC) {
949        Mismatches.push_back({Prop, IncompatibleType, ""});
950        continue;
951      }
952    }
953  }
954
955  if (Mismatches.empty())
956    return Property;
957
958  // Diagnose incompability.
959  {
960    bool HasIncompatibleAttributes = false;
961    for (const auto &Note : Mismatches)
962      HasIncompatibleAttributes =
963          Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
964    // Promote the warning to an error if there are incompatible attributes or
965    // incompatible types together with readwrite/readonly incompatibility.
966    auto Diag = S.Diag(Property->getLocation(),
967                       Property != OriginalProperty || HasIncompatibleAttributes
968                           ? diag::err_protocol_property_mismatch
969                           : diag::warn_protocol_property_mismatch);
970    Diag << Mismatches[0].Kind;
971    switch (Mismatches[0].Kind) {
972    case IncompatibleType:
973      Diag << Property->getType();
974      break;
975    case HasNoExpectedAttribute:
976    case HasUnexpectedAttribute:
977      Diag << Mismatches[0].AttributeName;
978      break;
979    case DifferentGetter:
980      Diag << Property->getGetterName();
981      break;
982    case DifferentSetter:
983      Diag << Property->getSetterName();
984      break;
985    }
986  }
987  for (const auto &Note : Mismatches) {
988    auto Diag =
989        S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
990        << Note.Kind;
991    switch (Note.Kind) {
992    case IncompatibleType:
993      Diag << Note.Prop->getType();
994      break;
995    case HasNoExpectedAttribute:
996    case HasUnexpectedAttribute:
997      Diag << Note.AttributeName;
998      break;
999    case DifferentGetter:
1000      Diag << Note.Prop->getGetterName();
1001      break;
1002    case DifferentSetter:
1003      Diag << Note.Prop->getSetterName();
1004      break;
1005    }
1006  }
1007  if (AtLoc.isValid())
1008    S.Diag(AtLoc, diag::note_property_synthesize);
1009
1010  return Property;
1011}
1012
1013/// Determine whether any storage attributes were written on the property.
1014static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
1015                                       ObjCPropertyQueryKind QueryKind) {
1016  if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
1017
1018  // If this is a readwrite property in a class extension that refines
1019  // a readonly property in the original class definition, check it as
1020  // well.
1021
1022  // If it's a readonly property, we're not interested.
1023  if (Prop->isReadOnly()) return false;
1024
1025  // Is it declared in an extension?
1026  auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
1027  if (!Category || !Category->IsClassExtension()) return false;
1028
1029  // Find the corresponding property in the primary class definition.
1030  auto OrigClass = Category->getClassInterface();
1031  for (auto *Found : OrigClass->lookup(Prop->getDeclName())) {
1032    if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
1033      return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1034  }
1035
1036  // Look through all of the protocols.
1037  for (const auto *Proto : OrigClass->all_referenced_protocols()) {
1038    if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
1039            Prop->getIdentifier(), QueryKind))
1040      return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1041  }
1042
1043  return false;
1044}
1045
1046/// Create a synthesized property accessor stub inside the \@implementation.
1047static ObjCMethodDecl *
1048RedeclarePropertyAccessor(ASTContext &Context, ObjCImplementationDecl *Impl,
1049                          ObjCMethodDecl *AccessorDecl, SourceLocation AtLoc,
1050                          SourceLocation PropertyLoc) {
1051  ObjCMethodDecl *Decl = AccessorDecl;
1052  ObjCMethodDecl *ImplDecl = ObjCMethodDecl::Create(
1053      Context, AtLoc.isValid() ? AtLoc : Decl->getBeginLoc(),
1054      PropertyLoc.isValid() ? PropertyLoc : Decl->getEndLoc(),
1055      Decl->getSelector(), Decl->getReturnType(),
1056      Decl->getReturnTypeSourceInfo(), Impl, Decl->isInstanceMethod(),
1057      Decl->isVariadic(), Decl->isPropertyAccessor(),
1058      /* isSynthesized*/ true, Decl->isImplicit(), Decl->isDefined(),
1059      Decl->getImplementationControl(), Decl->hasRelatedResultType());
1060  ImplDecl->getMethodFamily();
1061  if (Decl->hasAttrs())
1062    ImplDecl->setAttrs(Decl->getAttrs());
1063  ImplDecl->setSelfDecl(Decl->getSelfDecl());
1064  ImplDecl->setCmdDecl(Decl->getCmdDecl());
1065  SmallVector<SourceLocation, 1> SelLocs;
1066  Decl->getSelectorLocs(SelLocs);
1067  ImplDecl->setMethodParams(Context, Decl->parameters(), SelLocs);
1068  ImplDecl->setLexicalDeclContext(Impl);
1069  ImplDecl->setDefined(false);
1070  return ImplDecl;
1071}
1072
1073/// ActOnPropertyImplDecl - This routine performs semantic checks and
1074/// builds the AST node for a property implementation declaration; declared
1075/// as \@synthesize or \@dynamic.
1076///
1077Decl *Sema::ActOnPropertyImplDecl(Scope *S,
1078                                  SourceLocation AtLoc,
1079                                  SourceLocation PropertyLoc,
1080                                  bool Synthesize,
1081                                  IdentifierInfo *PropertyId,
1082                                  IdentifierInfo *PropertyIvar,
1083                                  SourceLocation PropertyIvarLoc,
1084                                  ObjCPropertyQueryKind QueryKind) {
1085  ObjCContainerDecl *ClassImpDecl =
1086    dyn_cast<ObjCContainerDecl>(CurContext);
1087  // Make sure we have a context for the property implementation declaration.
1088  if (!ClassImpDecl) {
1089    Diag(AtLoc, diag::err_missing_property_context);
1090    return nullptr;
1091  }
1092  if (PropertyIvarLoc.isInvalid())
1093    PropertyIvarLoc = PropertyLoc;
1094  SourceLocation PropertyDiagLoc = PropertyLoc;
1095  if (PropertyDiagLoc.isInvalid())
1096    PropertyDiagLoc = ClassImpDecl->getBeginLoc();
1097  ObjCPropertyDecl *property = nullptr;
1098  ObjCInterfaceDecl *IDecl = nullptr;
1099  // Find the class or category class where this property must have
1100  // a declaration.
1101  ObjCImplementationDecl *IC = nullptr;
1102  ObjCCategoryImplDecl *CatImplClass = nullptr;
1103  if ((IC = dyn_cast<ObjCImplementationDecl>(ClassImpDecl))) {
1104    IDecl = IC->getClassInterface();
1105    // We always synthesize an interface for an implementation
1106    // without an interface decl. So, IDecl is always non-zero.
1107    assert(IDecl &&
1108           "ActOnPropertyImplDecl - @implementation without @interface");
1109
1110    // Look for this property declaration in the @implementation's @interface
1111    property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
1112    if (!property) {
1113      Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
1114      return nullptr;
1115    }
1116    if (property->isClassProperty() && Synthesize) {
1117      Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
1118      return nullptr;
1119    }
1120    unsigned PIkind = property->getPropertyAttributesAsWritten();
1121    if ((PIkind & (ObjCPropertyAttribute::kind_atomic |
1122                   ObjCPropertyAttribute::kind_nonatomic)) == 0) {
1123      if (AtLoc.isValid())
1124        Diag(AtLoc, diag::warn_implicit_atomic_property);
1125      else
1126        Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
1127      Diag(property->getLocation(), diag::note_property_declare);
1128    }
1129
1130    if (const ObjCCategoryDecl *CD =
1131        dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
1132      if (!CD->IsClassExtension()) {
1133        Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
1134        Diag(property->getLocation(), diag::note_property_declare);
1135        return nullptr;
1136      }
1137    }
1138    if (Synthesize && (PIkind & ObjCPropertyAttribute::kind_readonly) &&
1139        property->hasAttr<IBOutletAttr>() && !AtLoc.isValid()) {
1140      bool ReadWriteProperty = false;
1141      // Search into the class extensions and see if 'readonly property is
1142      // redeclared 'readwrite', then no warning is to be issued.
1143      for (auto *Ext : IDecl->known_extensions()) {
1144        DeclContext::lookup_result R = Ext->lookup(property->getDeclName());
1145        if (auto *ExtProp = R.find_first<ObjCPropertyDecl>()) {
1146          PIkind = ExtProp->getPropertyAttributesAsWritten();
1147          if (PIkind & ObjCPropertyAttribute::kind_readwrite) {
1148            ReadWriteProperty = true;
1149            break;
1150          }
1151        }
1152      }
1153
1154      if (!ReadWriteProperty) {
1155        Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
1156            << property;
1157        SourceLocation readonlyLoc;
1158        if (LocPropertyAttribute(Context, "readonly",
1159                                 property->getLParenLoc(), readonlyLoc)) {
1160          SourceLocation endLoc =
1161            readonlyLoc.getLocWithOffset(strlen("readonly")-1);
1162          SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
1163          Diag(property->getLocation(),
1164               diag::note_auto_readonly_iboutlet_fixup_suggest) <<
1165          FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
1166        }
1167      }
1168    }
1169    if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
1170      property = SelectPropertyForSynthesisFromProtocols(*this, AtLoc, IDecl,
1171                                                         property);
1172
1173  } else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ClassImpDecl))) {
1174    if (Synthesize) {
1175      Diag(AtLoc, diag::err_synthesize_category_decl);
1176      return nullptr;
1177    }
1178    IDecl = CatImplClass->getClassInterface();
1179    if (!IDecl) {
1180      Diag(AtLoc, diag::err_missing_property_interface);
1181      return nullptr;
1182    }
1183    ObjCCategoryDecl *Category =
1184    IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier());
1185
1186    // If category for this implementation not found, it is an error which
1187    // has already been reported eralier.
1188    if (!Category)
1189      return nullptr;
1190    // Look for this property declaration in @implementation's category
1191    property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
1192    if (!property) {
1193      Diag(PropertyLoc, diag::err_bad_category_property_decl)
1194      << Category->getDeclName();
1195      return nullptr;
1196    }
1197  } else {
1198    Diag(AtLoc, diag::err_bad_property_context);
1199    return nullptr;
1200  }
1201  ObjCIvarDecl *Ivar = nullptr;
1202  bool CompleteTypeErr = false;
1203  bool compat = true;
1204  // Check that we have a valid, previously declared ivar for @synthesize
1205  if (Synthesize) {
1206    // @synthesize
1207    if (!PropertyIvar)
1208      PropertyIvar = PropertyId;
1209    // Check that this is a previously declared 'ivar' in 'IDecl' interface
1210    ObjCInterfaceDecl *ClassDeclared;
1211    Ivar = IDecl->lookupInstanceVariable(PropertyIvar, ClassDeclared);
1212    QualType PropType = property->getType();
1213    QualType PropertyIvarType = PropType.getNonReferenceType();
1214
1215    if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
1216                            diag::err_incomplete_synthesized_property,
1217                            property->getDeclName())) {
1218      Diag(property->getLocation(), diag::note_property_declare);
1219      CompleteTypeErr = true;
1220    }
1221
1222    if (getLangOpts().ObjCAutoRefCount &&
1223        (property->getPropertyAttributesAsWritten() &
1224         ObjCPropertyAttribute::kind_readonly) &&
1225        PropertyIvarType->isObjCRetainableType()) {
1226      setImpliedPropertyAttributeForReadOnlyProperty(property, Ivar);
1227    }
1228
1229    ObjCPropertyAttribute::Kind kind = property->getPropertyAttributes();
1230
1231    bool isARCWeak = false;
1232    if (kind & ObjCPropertyAttribute::kind_weak) {
1233      // Add GC __weak to the ivar type if the property is weak.
1234      if (getLangOpts().getGC() != LangOptions::NonGC) {
1235        assert(!getLangOpts().ObjCAutoRefCount);
1236        if (PropertyIvarType.isObjCGCStrong()) {
1237          Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
1238          Diag(property->getLocation(), diag::note_property_declare);
1239        } else {
1240          PropertyIvarType =
1241            Context.getObjCGCQualType(PropertyIvarType, Qualifiers::Weak);
1242        }
1243
1244      // Otherwise, check whether ARC __weak is enabled and works with
1245      // the property type.
1246      } else {
1247        if (!getLangOpts().ObjCWeak) {
1248          // Only complain here when synthesizing an ivar.
1249          if (!Ivar) {
1250            Diag(PropertyDiagLoc,
1251                 getLangOpts().ObjCWeakRuntime
1252                   ? diag::err_synthesizing_arc_weak_property_disabled
1253                   : diag::err_synthesizing_arc_weak_property_no_runtime);
1254            Diag(property->getLocation(), diag::note_property_declare);
1255          }
1256          CompleteTypeErr = true; // suppress later diagnostics about the ivar
1257        } else {
1258          isARCWeak = true;
1259          if (const ObjCObjectPointerType *ObjT =
1260                PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1261            const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1262            if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1263              Diag(property->getLocation(),
1264                   diag::err_arc_weak_unavailable_property)
1265                << PropertyIvarType;
1266              Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1267                << ClassImpDecl->getName();
1268            }
1269          }
1270        }
1271      }
1272    }
1273
1274    if (AtLoc.isInvalid()) {
1275      // Check when default synthesizing a property that there is
1276      // an ivar matching property name and issue warning; since this
1277      // is the most common case of not using an ivar used for backing
1278      // property in non-default synthesis case.
1279      ObjCInterfaceDecl *ClassDeclared=nullptr;
1280      ObjCIvarDecl *originalIvar =
1281      IDecl->lookupInstanceVariable(property->getIdentifier(),
1282                                    ClassDeclared);
1283      if (originalIvar) {
1284        Diag(PropertyDiagLoc,
1285             diag::warn_autosynthesis_property_ivar_match)
1286        << PropertyId << (Ivar == nullptr) << PropertyIvar
1287        << originalIvar->getIdentifier();
1288        Diag(property->getLocation(), diag::note_property_declare);
1289        Diag(originalIvar->getLocation(), diag::note_ivar_decl);
1290      }
1291    }
1292
1293    if (!Ivar) {
1294      // In ARC, give the ivar a lifetime qualifier based on the
1295      // property attributes.
1296      if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
1297          !PropertyIvarType.getObjCLifetime() &&
1298          PropertyIvarType->isObjCRetainableType()) {
1299
1300        // It's an error if we have to do this and the user didn't
1301        // explicitly write an ownership attribute on the property.
1302        if (!hasWrittenStorageAttribute(property, QueryKind) &&
1303            !(kind & ObjCPropertyAttribute::kind_strong)) {
1304          Diag(PropertyDiagLoc,
1305               diag::err_arc_objc_property_default_assign_on_object);
1306          Diag(property->getLocation(), diag::note_property_declare);
1307        } else {
1308          Qualifiers::ObjCLifetime lifetime =
1309            getImpliedARCOwnership(kind, PropertyIvarType);
1310          assert(lifetime && "no lifetime for property?");
1311
1312          Qualifiers qs;
1313          qs.addObjCLifetime(lifetime);
1314          PropertyIvarType = Context.getQualifiedType(PropertyIvarType, qs);
1315        }
1316      }
1317
1318      Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl,
1319                                  PropertyIvarLoc,PropertyIvarLoc, PropertyIvar,
1320                                  PropertyIvarType, /*TInfo=*/nullptr,
1321                                  ObjCIvarDecl::Private,
1322                                  (Expr *)nullptr, true);
1323      if (RequireNonAbstractType(PropertyIvarLoc,
1324                                 PropertyIvarType,
1325                                 diag::err_abstract_type_in_decl,
1326                                 AbstractSynthesizedIvarType)) {
1327        Diag(property->getLocation(), diag::note_property_declare);
1328        // An abstract type is as bad as an incomplete type.
1329        CompleteTypeErr = true;
1330      }
1331      if (!CompleteTypeErr) {
1332        const RecordType *RecordTy = PropertyIvarType->getAs<RecordType>();
1333        if (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()) {
1334          Diag(PropertyIvarLoc, diag::err_synthesize_variable_sized_ivar)
1335            << PropertyIvarType;
1336          CompleteTypeErr = true; // suppress later diagnostics about the ivar
1337        }
1338      }
1339      if (CompleteTypeErr)
1340        Ivar->setInvalidDecl();
1341      ClassImpDecl->addDecl(Ivar);
1342      IDecl->makeDeclVisibleInContext(Ivar);
1343
1344      if (getLangOpts().ObjCRuntime.isFragile())
1345        Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
1346            << PropertyId;
1347      // Note! I deliberately want it to fall thru so, we have a
1348      // a property implementation and to avoid future warnings.
1349    } else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1350               !declaresSameEntity(ClassDeclared, IDecl)) {
1351      Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
1352      << property->getDeclName() << Ivar->getDeclName()
1353      << ClassDeclared->getDeclName();
1354      Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1355      << Ivar << Ivar->getName();
1356      // Note! I deliberately want it to fall thru so more errors are caught.
1357    }
1358    property->setPropertyIvarDecl(Ivar);
1359
1360    QualType IvarType = Context.getCanonicalType(Ivar->getType());
1361
1362    // Check that type of property and its ivar are type compatible.
1363    if (!Context.hasSameType(PropertyIvarType, IvarType)) {
1364      if (isa<ObjCObjectPointerType>(PropertyIvarType)
1365          && isa<ObjCObjectPointerType>(IvarType))
1366        compat =
1367          Context.canAssignObjCInterfaces(
1368                                  PropertyIvarType->getAs<ObjCObjectPointerType>(),
1369                                  IvarType->getAs<ObjCObjectPointerType>());
1370      else {
1371        compat = (CheckAssignmentConstraints(PropertyIvarLoc, PropertyIvarType,
1372                                             IvarType)
1373                    == Compatible);
1374      }
1375      if (!compat) {
1376        Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1377          << property->getDeclName() << PropType
1378          << Ivar->getDeclName() << IvarType;
1379        Diag(Ivar->getLocation(), diag::note_ivar_decl);
1380        // Note! I deliberately want it to fall thru so, we have a
1381        // a property implementation and to avoid future warnings.
1382      }
1383      else {
1384        // FIXME! Rules for properties are somewhat different that those
1385        // for assignments. Use a new routine to consolidate all cases;
1386        // specifically for property redeclarations as well as for ivars.
1387        QualType lhsType =Context.getCanonicalType(PropertyIvarType).getUnqualifiedType();
1388        QualType rhsType =Context.getCanonicalType(IvarType).getUnqualifiedType();
1389        if (lhsType != rhsType &&
1390            lhsType->isArithmeticType()) {
1391          Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1392            << property->getDeclName() << PropType
1393            << Ivar->getDeclName() << IvarType;
1394          Diag(Ivar->getLocation(), diag::note_ivar_decl);
1395          // Fall thru - see previous comment
1396        }
1397      }
1398      // __weak is explicit. So it works on Canonical type.
1399      if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1400           getLangOpts().getGC() != LangOptions::NonGC)) {
1401        Diag(PropertyDiagLoc, diag::err_weak_property)
1402        << property->getDeclName() << Ivar->getDeclName();
1403        Diag(Ivar->getLocation(), diag::note_ivar_decl);
1404        // Fall thru - see previous comment
1405      }
1406      // Fall thru - see previous comment
1407      if ((property->getType()->isObjCObjectPointerType() ||
1408           PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1409          getLangOpts().getGC() != LangOptions::NonGC) {
1410        Diag(PropertyDiagLoc, diag::err_strong_property)
1411        << property->getDeclName() << Ivar->getDeclName();
1412        // Fall thru - see previous comment
1413      }
1414    }
1415    if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1416        Ivar->getType().getObjCLifetime())
1417      checkARCPropertyImpl(*this, PropertyLoc, property, Ivar);
1418  } else if (PropertyIvar)
1419    // @dynamic
1420    Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
1421
1422  assert (property && "ActOnPropertyImplDecl - property declaration missing");
1423  ObjCPropertyImplDecl *PIDecl =
1424  ObjCPropertyImplDecl::Create(Context, CurContext, AtLoc, PropertyLoc,
1425                               property,
1426                               (Synthesize ?
1427                                ObjCPropertyImplDecl::Synthesize
1428                                : ObjCPropertyImplDecl::Dynamic),
1429                               Ivar, PropertyIvarLoc);
1430
1431  if (CompleteTypeErr || !compat)
1432    PIDecl->setInvalidDecl();
1433
1434  if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1435    getterMethod->createImplicitParams(Context, IDecl);
1436
1437    // Redeclare the getter within the implementation as DeclContext.
1438    if (Synthesize) {
1439      // If the method hasn't been overridden, create a synthesized implementation.
1440      ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
1441          getterMethod->getSelector(), getterMethod->isInstanceMethod());
1442      if (!OMD)
1443        OMD = RedeclarePropertyAccessor(Context, IC, getterMethod, AtLoc,
1444                                        PropertyLoc);
1445      PIDecl->setGetterMethodDecl(OMD);
1446    }
1447
1448    if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1449        Ivar->getType()->isRecordType()) {
1450      // For Objective-C++, need to synthesize the AST for the IVAR object to be
1451      // returned by the getter as it must conform to C++'s copy-return rules.
1452      // FIXME. Eventually we want to do this for Objective-C as well.
1453      SynthesizedFunctionScope Scope(*this, getterMethod);
1454      ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1455      DeclRefExpr *SelfExpr = new (Context)
1456          DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1457                      PropertyDiagLoc);
1458      MarkDeclRefReferenced(SelfExpr);
1459      Expr *LoadSelfExpr = ImplicitCastExpr::Create(
1460          Context, SelfDecl->getType(), CK_LValueToRValue, SelfExpr, nullptr,
1461          VK_PRValue, FPOptionsOverride());
1462      Expr *IvarRefExpr =
1463        new (Context) ObjCIvarRefExpr(Ivar,
1464                                      Ivar->getUsageType(SelfDecl->getType()),
1465                                      PropertyDiagLoc,
1466                                      Ivar->getLocation(),
1467                                      LoadSelfExpr, true, true);
1468      ExprResult Res = PerformCopyInitialization(
1469          InitializedEntity::InitializeResult(PropertyDiagLoc,
1470                                              getterMethod->getReturnType()),
1471          PropertyDiagLoc, IvarRefExpr);
1472      if (!Res.isInvalid()) {
1473        Expr *ResExpr = Res.getAs<Expr>();
1474        if (ResExpr)
1475          ResExpr = MaybeCreateExprWithCleanups(ResExpr);
1476        PIDecl->setGetterCXXConstructor(ResExpr);
1477      }
1478    }
1479    if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1480        !getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1481      Diag(getterMethod->getLocation(),
1482           diag::warn_property_getter_owning_mismatch);
1483      Diag(property->getLocation(), diag::note_property_declare);
1484    }
1485    if (getLangOpts().ObjCAutoRefCount && Synthesize)
1486      switch (getterMethod->getMethodFamily()) {
1487        case OMF_retain:
1488        case OMF_retainCount:
1489        case OMF_release:
1490        case OMF_autorelease:
1491          Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1492            << 1 << getterMethod->getSelector();
1493          break;
1494        default:
1495          break;
1496      }
1497  }
1498
1499  if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1500    setterMethod->createImplicitParams(Context, IDecl);
1501
1502    // Redeclare the setter within the implementation as DeclContext.
1503    if (Synthesize) {
1504      ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
1505          setterMethod->getSelector(), setterMethod->isInstanceMethod());
1506      if (!OMD)
1507        OMD = RedeclarePropertyAccessor(Context, IC, setterMethod,
1508                                        AtLoc, PropertyLoc);
1509      PIDecl->setSetterMethodDecl(OMD);
1510    }
1511
1512    if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1513        Ivar->getType()->isRecordType()) {
1514      // FIXME. Eventually we want to do this for Objective-C as well.
1515      SynthesizedFunctionScope Scope(*this, setterMethod);
1516      ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1517      DeclRefExpr *SelfExpr = new (Context)
1518          DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1519                      PropertyDiagLoc);
1520      MarkDeclRefReferenced(SelfExpr);
1521      Expr *LoadSelfExpr = ImplicitCastExpr::Create(
1522          Context, SelfDecl->getType(), CK_LValueToRValue, SelfExpr, nullptr,
1523          VK_PRValue, FPOptionsOverride());
1524      Expr *lhs =
1525        new (Context) ObjCIvarRefExpr(Ivar,
1526                                      Ivar->getUsageType(SelfDecl->getType()),
1527                                      PropertyDiagLoc,
1528                                      Ivar->getLocation(),
1529                                      LoadSelfExpr, true, true);
1530      ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1531      ParmVarDecl *Param = (*P);
1532      QualType T = Param->getType().getNonReferenceType();
1533      DeclRefExpr *rhs = new (Context)
1534          DeclRefExpr(Context, Param, false, T, VK_LValue, PropertyDiagLoc);
1535      MarkDeclRefReferenced(rhs);
1536      ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1537                                  BO_Assign, lhs, rhs);
1538      if (property->getPropertyAttributes() &
1539          ObjCPropertyAttribute::kind_atomic) {
1540        Expr *callExpr = Res.getAs<Expr>();
1541        if (const CXXOperatorCallExpr *CXXCE =
1542              dyn_cast_or_null<CXXOperatorCallExpr>(callExpr))
1543          if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1544            if (!FuncDecl->isTrivial())
1545              if (property->getType()->isReferenceType()) {
1546                Diag(PropertyDiagLoc,
1547                     diag::err_atomic_property_nontrivial_assign_op)
1548                    << property->getType();
1549                Diag(FuncDecl->getBeginLoc(), diag::note_callee_decl)
1550                    << FuncDecl;
1551              }
1552      }
1553      PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1554    }
1555  }
1556
1557  if (IC) {
1558    if (Synthesize)
1559      if (ObjCPropertyImplDecl *PPIDecl =
1560          IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1561        Diag(PropertyLoc, diag::err_duplicate_ivar_use)
1562        << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1563        << PropertyIvar;
1564        Diag(PPIDecl->getLocation(), diag::note_previous_use);
1565      }
1566
1567    if (ObjCPropertyImplDecl *PPIDecl
1568        = IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
1569      Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
1570      Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1571      return nullptr;
1572    }
1573    IC->addPropertyImplementation(PIDecl);
1574    if (getLangOpts().ObjCDefaultSynthProperties &&
1575        getLangOpts().ObjCRuntime.isNonFragile() &&
1576        !IDecl->isObjCRequiresPropertyDefs()) {
1577      // Diagnose if an ivar was lazily synthesdized due to a previous
1578      // use and if 1) property is @dynamic or 2) property is synthesized
1579      // but it requires an ivar of different name.
1580      ObjCInterfaceDecl *ClassDeclared=nullptr;
1581      ObjCIvarDecl *Ivar = nullptr;
1582      if (!Synthesize)
1583        Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1584      else {
1585        if (PropertyIvar && PropertyIvar != PropertyId)
1586          Ivar = IDecl->lookupInstanceVariable(PropertyId, ClassDeclared);
1587      }
1588      // Issue diagnostics only if Ivar belongs to current class.
1589      if (Ivar && Ivar->getSynthesize() &&
1590          declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1591        Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1592        << PropertyId;
1593        Ivar->setInvalidDecl();
1594      }
1595    }
1596  } else {
1597    if (Synthesize)
1598      if (ObjCPropertyImplDecl *PPIDecl =
1599          CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1600        Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
1601        << PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1602        << PropertyIvar;
1603        Diag(PPIDecl->getLocation(), diag::note_previous_use);
1604      }
1605
1606    if (ObjCPropertyImplDecl *PPIDecl =
1607        CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
1608      Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
1609      Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1610      return nullptr;
1611    }
1612    CatImplClass->addPropertyImplementation(PIDecl);
1613  }
1614
1615  if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic &&
1616      PIDecl->getPropertyDecl() &&
1617      PIDecl->getPropertyDecl()->isDirectProperty()) {
1618    Diag(PropertyLoc, diag::err_objc_direct_dynamic_property);
1619    Diag(PIDecl->getPropertyDecl()->getLocation(),
1620         diag::note_previous_declaration);
1621    return nullptr;
1622  }
1623
1624  return PIDecl;
1625}
1626
1627//===----------------------------------------------------------------------===//
1628// Helper methods.
1629//===----------------------------------------------------------------------===//
1630
1631/// DiagnosePropertyMismatch - Compares two properties for their
1632/// attributes and types and warns on a variety of inconsistencies.
1633///
1634void
1635Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1636                               ObjCPropertyDecl *SuperProperty,
1637                               const IdentifierInfo *inheritedName,
1638                               bool OverridingProtocolProperty) {
1639  ObjCPropertyAttribute::Kind CAttr = Property->getPropertyAttributes();
1640  ObjCPropertyAttribute::Kind SAttr = SuperProperty->getPropertyAttributes();
1641
1642  // We allow readonly properties without an explicit ownership
1643  // (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1644  // to be overridden by a property with any explicit ownership in the subclass.
1645  if (!OverridingProtocolProperty &&
1646      !getOwnershipRule(SAttr) && getOwnershipRule(CAttr))
1647    ;
1648  else {
1649    if ((CAttr & ObjCPropertyAttribute::kind_readonly) &&
1650        (SAttr & ObjCPropertyAttribute::kind_readwrite))
1651      Diag(Property->getLocation(), diag::warn_readonly_property)
1652        << Property->getDeclName() << inheritedName;
1653    if ((CAttr & ObjCPropertyAttribute::kind_copy) !=
1654        (SAttr & ObjCPropertyAttribute::kind_copy))
1655      Diag(Property->getLocation(), diag::warn_property_attribute)
1656        << Property->getDeclName() << "copy" << inheritedName;
1657    else if (!(SAttr & ObjCPropertyAttribute::kind_readonly)) {
1658      unsigned CAttrRetain = (CAttr & (ObjCPropertyAttribute::kind_retain |
1659                                       ObjCPropertyAttribute::kind_strong));
1660      unsigned SAttrRetain = (SAttr & (ObjCPropertyAttribute::kind_retain |
1661                                       ObjCPropertyAttribute::kind_strong));
1662      bool CStrong = (CAttrRetain != 0);
1663      bool SStrong = (SAttrRetain != 0);
1664      if (CStrong != SStrong)
1665        Diag(Property->getLocation(), diag::warn_property_attribute)
1666          << Property->getDeclName() << "retain (or strong)" << inheritedName;
1667    }
1668  }
1669
1670  // Check for nonatomic; note that nonatomic is effectively
1671  // meaningless for readonly properties, so don't diagnose if the
1672  // atomic property is 'readonly'.
1673  checkAtomicPropertyMismatch(*this, SuperProperty, Property, false);
1674  // Readonly properties from protocols can be implemented as "readwrite"
1675  // with a custom setter name.
1676  if (Property->getSetterName() != SuperProperty->getSetterName() &&
1677      !(SuperProperty->isReadOnly() &&
1678        isa<ObjCProtocolDecl>(SuperProperty->getDeclContext()))) {
1679    Diag(Property->getLocation(), diag::warn_property_attribute)
1680      << Property->getDeclName() << "setter" << inheritedName;
1681    Diag(SuperProperty->getLocation(), diag::note_property_declare);
1682  }
1683  if (Property->getGetterName() != SuperProperty->getGetterName()) {
1684    Diag(Property->getLocation(), diag::warn_property_attribute)
1685      << Property->getDeclName() << "getter" << inheritedName;
1686    Diag(SuperProperty->getLocation(), diag::note_property_declare);
1687  }
1688
1689  QualType LHSType =
1690    Context.getCanonicalType(SuperProperty->getType());
1691  QualType RHSType =
1692    Context.getCanonicalType(Property->getType());
1693
1694  if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1695    // Do cases not handled in above.
1696    // FIXME. For future support of covariant property types, revisit this.
1697    bool IncompatibleObjC = false;
1698    QualType ConvertedType;
1699    if (!isObjCPointerConversion(RHSType, LHSType,
1700                                 ConvertedType, IncompatibleObjC) ||
1701        IncompatibleObjC) {
1702        Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1703        << Property->getType() << SuperProperty->getType() << inheritedName;
1704      Diag(SuperProperty->getLocation(), diag::note_property_declare);
1705    }
1706  }
1707}
1708
1709bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1710                                            ObjCMethodDecl *GetterMethod,
1711                                            SourceLocation Loc) {
1712  if (!GetterMethod)
1713    return false;
1714  QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1715  QualType PropertyRValueType =
1716      property->getType().getNonReferenceType().getAtomicUnqualifiedType();
1717  bool compat = Context.hasSameType(PropertyRValueType, GetterType);
1718  if (!compat) {
1719    const ObjCObjectPointerType *propertyObjCPtr = nullptr;
1720    const ObjCObjectPointerType *getterObjCPtr = nullptr;
1721    if ((propertyObjCPtr =
1722             PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
1723        (getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
1724      compat = Context.canAssignObjCInterfaces(getterObjCPtr, propertyObjCPtr);
1725    else if (CheckAssignmentConstraints(Loc, GetterType, PropertyRValueType)
1726              != Compatible) {
1727          Diag(Loc, diag::err_property_accessor_type)
1728            << property->getDeclName() << PropertyRValueType
1729            << GetterMethod->getSelector() << GetterType;
1730          Diag(GetterMethod->getLocation(), diag::note_declared_at);
1731          return true;
1732    } else {
1733      compat = true;
1734      QualType lhsType = Context.getCanonicalType(PropertyRValueType);
1735      QualType rhsType =Context.getCanonicalType(GetterType).getUnqualifiedType();
1736      if (lhsType != rhsType && lhsType->isArithmeticType())
1737        compat = false;
1738    }
1739  }
1740
1741  if (!compat) {
1742    Diag(Loc, diag::warn_accessor_property_type_mismatch)
1743    << property->getDeclName()
1744    << GetterMethod->getSelector();
1745    Diag(GetterMethod->getLocation(), diag::note_declared_at);
1746    return true;
1747  }
1748
1749  return false;
1750}
1751
1752/// CollectImmediateProperties - This routine collects all properties in
1753/// the class and its conforming protocols; but not those in its super class.
1754static void
1755CollectImmediateProperties(ObjCContainerDecl *CDecl,
1756                           ObjCContainerDecl::PropertyMap &PropMap,
1757                           ObjCContainerDecl::PropertyMap &SuperPropMap,
1758                           bool CollectClassPropsOnly = false,
1759                           bool IncludeProtocols = true) {
1760  if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1761    for (auto *Prop : IDecl->properties()) {
1762      if (CollectClassPropsOnly && !Prop->isClassProperty())
1763        continue;
1764      PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1765          Prop;
1766    }
1767
1768    // Collect the properties from visible extensions.
1769    for (auto *Ext : IDecl->visible_extensions())
1770      CollectImmediateProperties(Ext, PropMap, SuperPropMap,
1771                                 CollectClassPropsOnly, IncludeProtocols);
1772
1773    if (IncludeProtocols) {
1774      // Scan through class's protocols.
1775      for (auto *PI : IDecl->all_referenced_protocols())
1776        CollectImmediateProperties(PI, PropMap, SuperPropMap,
1777                                   CollectClassPropsOnly);
1778    }
1779  }
1780  if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1781    for (auto *Prop : CATDecl->properties()) {
1782      if (CollectClassPropsOnly && !Prop->isClassProperty())
1783        continue;
1784      PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1785          Prop;
1786    }
1787    if (IncludeProtocols) {
1788      // Scan through class's protocols.
1789      for (auto *PI : CATDecl->protocols())
1790        CollectImmediateProperties(PI, PropMap, SuperPropMap,
1791                                   CollectClassPropsOnly);
1792    }
1793  }
1794  else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1795    for (auto *Prop : PDecl->properties()) {
1796      if (CollectClassPropsOnly && !Prop->isClassProperty())
1797        continue;
1798      ObjCPropertyDecl *PropertyFromSuper =
1799          SuperPropMap[std::make_pair(Prop->getIdentifier(),
1800                                      Prop->isClassProperty())];
1801      // Exclude property for protocols which conform to class's super-class,
1802      // as super-class has to implement the property.
1803      if (!PropertyFromSuper ||
1804          PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1805        ObjCPropertyDecl *&PropEntry =
1806            PropMap[std::make_pair(Prop->getIdentifier(),
1807                                   Prop->isClassProperty())];
1808        if (!PropEntry)
1809          PropEntry = Prop;
1810      }
1811    }
1812    // Scan through protocol's protocols.
1813    for (auto *PI : PDecl->protocols())
1814      CollectImmediateProperties(PI, PropMap, SuperPropMap,
1815                                 CollectClassPropsOnly);
1816  }
1817}
1818
1819/// CollectSuperClassPropertyImplementations - This routine collects list of
1820/// properties to be implemented in super class(s) and also coming from their
1821/// conforming protocols.
1822static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1823                                    ObjCInterfaceDecl::PropertyMap &PropMap) {
1824  if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1825    while (SDecl) {
1826      SDecl->collectPropertiesToImplement(PropMap);
1827      SDecl = SDecl->getSuperClass();
1828    }
1829  }
1830}
1831
1832/// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1833/// an ivar synthesized for 'Method' and 'Method' is a property accessor
1834/// declared in class 'IFace'.
1835bool
1836Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1837                                     ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1838  if (!IV->getSynthesize())
1839    return false;
1840  ObjCMethodDecl *IMD = IFace->lookupMethod(Method->getSelector(),
1841                                            Method->isInstanceMethod());
1842  if (!IMD || !IMD->isPropertyAccessor())
1843    return false;
1844
1845  // look up a property declaration whose one of its accessors is implemented
1846  // by this method.
1847  for (const auto *Property : IFace->instance_properties()) {
1848    if ((Property->getGetterName() == IMD->getSelector() ||
1849         Property->getSetterName() == IMD->getSelector()) &&
1850        (Property->getPropertyIvarDecl() == IV))
1851      return true;
1852  }
1853  // Also look up property declaration in class extension whose one of its
1854  // accessors is implemented by this method.
1855  for (const auto *Ext : IFace->known_extensions())
1856    for (const auto *Property : Ext->instance_properties())
1857      if ((Property->getGetterName() == IMD->getSelector() ||
1858           Property->getSetterName() == IMD->getSelector()) &&
1859          (Property->getPropertyIvarDecl() == IV))
1860        return true;
1861  return false;
1862}
1863
1864static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1865                                         ObjCPropertyDecl *Prop) {
1866  bool SuperClassImplementsGetter = false;
1867  bool SuperClassImplementsSetter = false;
1868  if (Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_readonly)
1869    SuperClassImplementsSetter = true;
1870
1871  while (IDecl->getSuperClass()) {
1872    ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1873    if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1874      SuperClassImplementsGetter = true;
1875
1876    if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1877      SuperClassImplementsSetter = true;
1878    if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1879      return true;
1880    IDecl = IDecl->getSuperClass();
1881  }
1882  return false;
1883}
1884
1885/// Default synthesizes all properties which must be synthesized
1886/// in class's \@implementation.
1887void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
1888                                       ObjCInterfaceDecl *IDecl,
1889                                       SourceLocation AtEnd) {
1890  ObjCInterfaceDecl::PropertyMap PropMap;
1891  IDecl->collectPropertiesToImplement(PropMap);
1892  if (PropMap.empty())
1893    return;
1894  ObjCInterfaceDecl::PropertyMap SuperPropMap;
1895  CollectSuperClassPropertyImplementations(IDecl, SuperPropMap);
1896
1897  for (const auto &PropEntry : PropMap) {
1898    ObjCPropertyDecl *Prop = PropEntry.second;
1899    // Is there a matching property synthesize/dynamic?
1900    if (Prop->isInvalidDecl() ||
1901        Prop->isClassProperty() ||
1902        Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1903      continue;
1904    // Property may have been synthesized by user.
1905    if (IMPDecl->FindPropertyImplDecl(
1906            Prop->getIdentifier(), Prop->getQueryKind()))
1907      continue;
1908    ObjCMethodDecl *ImpMethod = IMPDecl->getInstanceMethod(Prop->getGetterName());
1909    if (ImpMethod && !ImpMethod->getBody()) {
1910      if (Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_readonly)
1911        continue;
1912      ImpMethod = IMPDecl->getInstanceMethod(Prop->getSetterName());
1913      if (ImpMethod && !ImpMethod->getBody())
1914        continue;
1915    }
1916    if (ObjCPropertyImplDecl *PID =
1917        IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
1918      Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1919        << Prop->getIdentifier();
1920      if (PID->getLocation().isValid())
1921        Diag(PID->getLocation(), diag::note_property_synthesize);
1922      continue;
1923    }
1924    ObjCPropertyDecl *PropInSuperClass =
1925        SuperPropMap[std::make_pair(Prop->getIdentifier(),
1926                                    Prop->isClassProperty())];
1927    if (ObjCProtocolDecl *Proto =
1928          dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1929      // We won't auto-synthesize properties declared in protocols.
1930      // Suppress the warning if class's superclass implements property's
1931      // getter and implements property's setter (if readwrite property).
1932      // Or, if property is going to be implemented in its super class.
1933      if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1934        Diag(IMPDecl->getLocation(),
1935             diag::warn_auto_synthesizing_protocol_property)
1936          << Prop << Proto;
1937        Diag(Prop->getLocation(), diag::note_property_declare);
1938        std::string FixIt =
1939            (Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
1940        Diag(AtEnd, diag::note_add_synthesize_directive)
1941            << FixItHint::CreateInsertion(AtEnd, FixIt);
1942      }
1943      continue;
1944    }
1945    // If property to be implemented in the super class, ignore.
1946    if (PropInSuperClass) {
1947      if ((Prop->getPropertyAttributes() &
1948           ObjCPropertyAttribute::kind_readwrite) &&
1949          (PropInSuperClass->getPropertyAttributes() &
1950           ObjCPropertyAttribute::kind_readonly) &&
1951          !IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1952          !IDecl->HasUserDeclaredSetterMethod(Prop)) {
1953        Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1954        << Prop->getIdentifier();
1955        Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1956      } else {
1957        Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1958        << Prop->getIdentifier();
1959        Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1960        Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1961      }
1962      continue;
1963    }
1964    // We use invalid SourceLocations for the synthesized ivars since they
1965    // aren't really synthesized at a particular location; they just exist.
1966    // Saying that they are located at the @implementation isn't really going
1967    // to help users.
1968    ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1969      ActOnPropertyImplDecl(S, SourceLocation(), SourceLocation(),
1970                            true,
1971                            /* property = */ Prop->getIdentifier(),
1972                            /* ivar = */ Prop->getDefaultSynthIvarName(Context),
1973                            Prop->getLocation(), Prop->getQueryKind()));
1974    if (PIDecl && !Prop->isUnavailable()) {
1975      Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1976      Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1977    }
1978  }
1979}
1980
1981void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
1982                                       SourceLocation AtEnd) {
1983  if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1984    return;
1985  ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(D);
1986  if (!IC)
1987    return;
1988  if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1989    if (!IDecl->isObjCRequiresPropertyDefs())
1990      DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
1991}
1992
1993static void DiagnoseUnimplementedAccessor(
1994    Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
1995    ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
1996    ObjCPropertyDecl *Prop,
1997    llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
1998  // Check to see if we have a corresponding selector in SMap and with the
1999  // right method type.
2000  auto I = llvm::find_if(SMap, [&](const ObjCMethodDecl *x) {
2001    return x->getSelector() == Method &&
2002           x->isClassMethod() == Prop->isClassProperty();
2003  });
2004  // When reporting on missing property setter/getter implementation in
2005  // categories, do not report when they are declared in primary class,
2006  // class's protocol, or one of it super classes. This is because,
2007  // the class is going to implement them.
2008  if (I == SMap.end() &&
2009      (PrimaryClass == nullptr ||
2010       !PrimaryClass->lookupPropertyAccessor(Method, C,
2011                                             Prop->isClassProperty()))) {
2012    unsigned diag =
2013        isa<ObjCCategoryDecl>(CDecl)
2014            ? (Prop->isClassProperty()
2015                   ? diag::warn_impl_required_in_category_for_class_property
2016                   : diag::warn_setter_getter_impl_required_in_category)
2017            : (Prop->isClassProperty()
2018                   ? diag::warn_impl_required_for_class_property
2019                   : diag::warn_setter_getter_impl_required);
2020    S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
2021    S.Diag(Prop->getLocation(), diag::note_property_declare);
2022    if (S.LangOpts.ObjCDefaultSynthProperties &&
2023        S.LangOpts.ObjCRuntime.isNonFragile())
2024      if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
2025        if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
2026          S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
2027  }
2028}
2029
2030void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
2031                                           ObjCContainerDecl *CDecl,
2032                                           bool SynthesizeProperties) {
2033  ObjCContainerDecl::PropertyMap PropMap;
2034  ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl);
2035
2036  // Since we don't synthesize class properties, we should emit diagnose even
2037  // if SynthesizeProperties is true.
2038  ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2039  // Gather properties which need not be implemented in this class
2040  // or category.
2041  if (!IDecl)
2042    if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
2043      // For categories, no need to implement properties declared in
2044      // its primary class (and its super classes) if property is
2045      // declared in one of those containers.
2046      if ((IDecl = C->getClassInterface())) {
2047        IDecl->collectPropertiesToImplement(NoNeedToImplPropMap);
2048      }
2049    }
2050  if (IDecl)
2051    CollectSuperClassPropertyImplementations(IDecl, NoNeedToImplPropMap);
2052
2053  // When SynthesizeProperties is true, we only check class properties.
2054  CollectImmediateProperties(CDecl, PropMap, NoNeedToImplPropMap,
2055                             SynthesizeProperties/*CollectClassPropsOnly*/);
2056
2057  // Scan the @interface to see if any of the protocols it adopts
2058  // require an explicit implementation, via attribute
2059  // 'objc_protocol_requires_explicit_implementation'.
2060  if (IDecl) {
2061    std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
2062
2063    for (auto *PDecl : IDecl->all_referenced_protocols()) {
2064      if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2065        continue;
2066      // Lazily construct a set of all the properties in the @interface
2067      // of the class, without looking at the superclass.  We cannot
2068      // use the call to CollectImmediateProperties() above as that
2069      // utilizes information from the super class's properties as well
2070      // as scans the adopted protocols.  This work only triggers for protocols
2071      // with the attribute, which is very rare, and only occurs when
2072      // analyzing the @implementation.
2073      if (!LazyMap) {
2074        ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2075        LazyMap.reset(new ObjCContainerDecl::PropertyMap());
2076        CollectImmediateProperties(CDecl, *LazyMap, NoNeedToImplPropMap,
2077                                   /* CollectClassPropsOnly */ false,
2078                                   /* IncludeProtocols */ false);
2079      }
2080      // Add the properties of 'PDecl' to the list of properties that
2081      // need to be implemented.
2082      for (auto *PropDecl : PDecl->properties()) {
2083        if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
2084                                      PropDecl->isClassProperty())])
2085          continue;
2086        PropMap[std::make_pair(PropDecl->getIdentifier(),
2087                               PropDecl->isClassProperty())] = PropDecl;
2088      }
2089    }
2090  }
2091
2092  if (PropMap.empty())
2093    return;
2094
2095  llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
2096  for (const auto *I : IMPDecl->property_impls())
2097    PropImplMap.insert(I->getPropertyDecl());
2098
2099  llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
2100  // Collect property accessors implemented in current implementation.
2101  for (const auto *I : IMPDecl->methods())
2102    InsMap.insert(I);
2103
2104  ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2105  ObjCInterfaceDecl *PrimaryClass = nullptr;
2106  if (C && !C->IsClassExtension())
2107    if ((PrimaryClass = C->getClassInterface()))
2108      // Report unimplemented properties in the category as well.
2109      if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
2110        // When reporting on missing setter/getters, do not report when
2111        // setter/getter is implemented in category's primary class
2112        // implementation.
2113        for (const auto *I : IMP->methods())
2114          InsMap.insert(I);
2115      }
2116
2117  for (ObjCContainerDecl::PropertyMap::iterator
2118       P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
2119    ObjCPropertyDecl *Prop = P->second;
2120    // Is there a matching property synthesize/dynamic?
2121    if (Prop->isInvalidDecl() ||
2122        Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
2123        PropImplMap.count(Prop) ||
2124        Prop->getAvailability() == AR_Unavailable)
2125      continue;
2126
2127    // Diagnose unimplemented getters and setters.
2128    DiagnoseUnimplementedAccessor(*this,
2129          PrimaryClass, Prop->getGetterName(), IMPDecl, CDecl, C, Prop, InsMap);
2130    if (!Prop->isReadOnly())
2131      DiagnoseUnimplementedAccessor(*this,
2132                                    PrimaryClass, Prop->getSetterName(),
2133                                    IMPDecl, CDecl, C, Prop, InsMap);
2134  }
2135}
2136
2137void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
2138  for (const auto *propertyImpl : impDecl->property_impls()) {
2139    const auto *property = propertyImpl->getPropertyDecl();
2140    // Warn about null_resettable properties with synthesized setters,
2141    // because the setter won't properly handle nil.
2142    if (propertyImpl->getPropertyImplementation() ==
2143            ObjCPropertyImplDecl::Synthesize &&
2144        (property->getPropertyAttributes() &
2145         ObjCPropertyAttribute::kind_null_resettable) &&
2146        property->getGetterMethodDecl() && property->getSetterMethodDecl()) {
2147      auto *getterImpl = propertyImpl->getGetterMethodDecl();
2148      auto *setterImpl = propertyImpl->getSetterMethodDecl();
2149      if ((!getterImpl || getterImpl->isSynthesizedAccessorStub()) &&
2150          (!setterImpl || setterImpl->isSynthesizedAccessorStub())) {
2151        SourceLocation loc = propertyImpl->getLocation();
2152        if (loc.isInvalid())
2153          loc = impDecl->getBeginLoc();
2154
2155        Diag(loc, diag::warn_null_resettable_setter)
2156          << setterImpl->getSelector() << property->getDeclName();
2157      }
2158    }
2159  }
2160}
2161
2162void
2163Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
2164                                       ObjCInterfaceDecl* IDecl) {
2165  // Rules apply in non-GC mode only
2166  if (getLangOpts().getGC() != LangOptions::NonGC)
2167    return;
2168  ObjCContainerDecl::PropertyMap PM;
2169  for (auto *Prop : IDecl->properties())
2170    PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2171  for (const auto *Ext : IDecl->known_extensions())
2172    for (auto *Prop : Ext->properties())
2173      PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2174
2175  for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
2176       I != E; ++I) {
2177    const ObjCPropertyDecl *Property = I->second;
2178    ObjCMethodDecl *GetterMethod = nullptr;
2179    ObjCMethodDecl *SetterMethod = nullptr;
2180
2181    unsigned Attributes = Property->getPropertyAttributes();
2182    unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
2183
2184    if (!(AttributesAsWritten & ObjCPropertyAttribute::kind_atomic) &&
2185        !(AttributesAsWritten & ObjCPropertyAttribute::kind_nonatomic)) {
2186      GetterMethod = Property->isClassProperty() ?
2187                     IMPDecl->getClassMethod(Property->getGetterName()) :
2188                     IMPDecl->getInstanceMethod(Property->getGetterName());
2189      SetterMethod = Property->isClassProperty() ?
2190                     IMPDecl->getClassMethod(Property->getSetterName()) :
2191                     IMPDecl->getInstanceMethod(Property->getSetterName());
2192      if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
2193        GetterMethod = nullptr;
2194      if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
2195        SetterMethod = nullptr;
2196      if (GetterMethod) {
2197        Diag(GetterMethod->getLocation(),
2198             diag::warn_default_atomic_custom_getter_setter)
2199          << Property->getIdentifier() << 0;
2200        Diag(Property->getLocation(), diag::note_property_declare);
2201      }
2202      if (SetterMethod) {
2203        Diag(SetterMethod->getLocation(),
2204             diag::warn_default_atomic_custom_getter_setter)
2205          << Property->getIdentifier() << 1;
2206        Diag(Property->getLocation(), diag::note_property_declare);
2207      }
2208    }
2209
2210    // We only care about readwrite atomic property.
2211    if ((Attributes & ObjCPropertyAttribute::kind_nonatomic) ||
2212        !(Attributes & ObjCPropertyAttribute::kind_readwrite))
2213      continue;
2214    if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
2215            Property->getIdentifier(), Property->getQueryKind())) {
2216      if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
2217        continue;
2218      GetterMethod = PIDecl->getGetterMethodDecl();
2219      SetterMethod = PIDecl->getSetterMethodDecl();
2220      if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
2221        GetterMethod = nullptr;
2222      if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
2223        SetterMethod = nullptr;
2224      if ((bool)GetterMethod ^ (bool)SetterMethod) {
2225        SourceLocation MethodLoc =
2226          (GetterMethod ? GetterMethod->getLocation()
2227                        : SetterMethod->getLocation());
2228        Diag(MethodLoc, diag::warn_atomic_property_rule)
2229          << Property->getIdentifier() << (GetterMethod != nullptr)
2230          << (SetterMethod != nullptr);
2231        // fixit stuff.
2232        if (Property->getLParenLoc().isValid() &&
2233            !(AttributesAsWritten & ObjCPropertyAttribute::kind_atomic)) {
2234          // @property () ... case.
2235          SourceLocation AfterLParen =
2236            getLocForEndOfToken(Property->getLParenLoc());
2237          StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
2238                                                      : "nonatomic";
2239          Diag(Property->getLocation(),
2240               diag::note_atomic_property_fixup_suggest)
2241            << FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
2242        } else if (Property->getLParenLoc().isInvalid()) {
2243          //@property id etc.
2244          SourceLocation startLoc =
2245            Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
2246          Diag(Property->getLocation(),
2247               diag::note_atomic_property_fixup_suggest)
2248            << FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
2249        } else
2250          Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
2251        Diag(Property->getLocation(), diag::note_property_declare);
2252      }
2253    }
2254  }
2255}
2256
2257void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
2258  if (getLangOpts().getGC() == LangOptions::GCOnly)
2259    return;
2260
2261  for (const auto *PID : D->property_impls()) {
2262    const ObjCPropertyDecl *PD = PID->getPropertyDecl();
2263    if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
2264        !PD->isClassProperty()) {
2265      ObjCMethodDecl *IM = PID->getGetterMethodDecl();
2266      if (IM && !IM->isSynthesizedAccessorStub())
2267        continue;
2268      ObjCMethodDecl *method = PD->getGetterMethodDecl();
2269      if (!method)
2270        continue;
2271      ObjCMethodFamily family = method->getMethodFamily();
2272      if (family == OMF_alloc || family == OMF_copy ||
2273          family == OMF_mutableCopy || family == OMF_new) {
2274        if (getLangOpts().ObjCAutoRefCount)
2275          Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
2276        else
2277          Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
2278
2279        // Look for a getter explicitly declared alongside the property.
2280        // If we find one, use its location for the note.
2281        SourceLocation noteLoc = PD->getLocation();
2282        SourceLocation fixItLoc;
2283        for (auto *getterRedecl : method->redecls()) {
2284          if (getterRedecl->isImplicit())
2285            continue;
2286          if (getterRedecl->getDeclContext() != PD->getDeclContext())
2287            continue;
2288          noteLoc = getterRedecl->getLocation();
2289          fixItLoc = getterRedecl->getEndLoc();
2290        }
2291
2292        Preprocessor &PP = getPreprocessor();
2293        TokenValue tokens[] = {
2294          tok::kw___attribute, tok::l_paren, tok::l_paren,
2295          PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
2296          PP.getIdentifierInfo("none"), tok::r_paren,
2297          tok::r_paren, tok::r_paren
2298        };
2299        StringRef spelling = "__attribute__((objc_method_family(none)))";
2300        StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
2301        if (!macroName.empty())
2302          spelling = macroName;
2303
2304        auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
2305            << method->getDeclName() << spelling;
2306        if (fixItLoc.isValid()) {
2307          SmallString<64> fixItText(" ");
2308          fixItText += spelling;
2309          noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
2310        }
2311      }
2312    }
2313  }
2314}
2315
2316void Sema::DiagnoseMissingDesignatedInitOverrides(
2317                                            const ObjCImplementationDecl *ImplD,
2318                                            const ObjCInterfaceDecl *IFD) {
2319  assert(IFD->hasDesignatedInitializers());
2320  const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
2321  if (!SuperD)
2322    return;
2323
2324  SelectorSet InitSelSet;
2325  for (const auto *I : ImplD->instance_methods())
2326    if (I->getMethodFamily() == OMF_init)
2327      InitSelSet.insert(I->getSelector());
2328
2329  SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
2330  SuperD->getDesignatedInitializers(DesignatedInits);
2331  for (SmallVector<const ObjCMethodDecl *, 8>::iterator
2332         I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
2333    const ObjCMethodDecl *MD = *I;
2334    if (!InitSelSet.count(MD->getSelector())) {
2335      // Don't emit a diagnostic if the overriding method in the subclass is
2336      // marked as unavailable.
2337      bool Ignore = false;
2338      if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
2339        Ignore = IMD->isUnavailable();
2340      } else {
2341        // Check the methods declared in the class extensions too.
2342        for (auto *Ext : IFD->visible_extensions())
2343          if (auto *IMD = Ext->getInstanceMethod(MD->getSelector())) {
2344            Ignore = IMD->isUnavailable();
2345            break;
2346          }
2347      }
2348      if (!Ignore) {
2349        Diag(ImplD->getLocation(),
2350             diag::warn_objc_implementation_missing_designated_init_override)
2351          << MD->getSelector();
2352        Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
2353      }
2354    }
2355  }
2356}
2357
2358/// AddPropertyAttrs - Propagates attributes from a property to the
2359/// implicitly-declared getter or setter for that property.
2360static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
2361                             ObjCPropertyDecl *Property) {
2362  // Should we just clone all attributes over?
2363  for (const auto *A : Property->attrs()) {
2364    if (isa<DeprecatedAttr>(A) ||
2365        isa<UnavailableAttr>(A) ||
2366        isa<AvailabilityAttr>(A))
2367      PropertyMethod->addAttr(A->clone(S.Context));
2368  }
2369}
2370
2371/// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
2372/// have the property type and issue diagnostics if they don't.
2373/// Also synthesize a getter/setter method if none exist (and update the
2374/// appropriate lookup tables.
2375void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
2376  ObjCMethodDecl *GetterMethod, *SetterMethod;
2377  ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
2378  if (CD->isInvalidDecl())
2379    return;
2380
2381  bool IsClassProperty = property->isClassProperty();
2382  GetterMethod = IsClassProperty ?
2383    CD->getClassMethod(property->getGetterName()) :
2384    CD->getInstanceMethod(property->getGetterName());
2385
2386  // if setter or getter is not found in class extension, it might be
2387  // in the primary class.
2388  if (!GetterMethod)
2389    if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2390      if (CatDecl->IsClassExtension())
2391        GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2392                         getClassMethod(property->getGetterName()) :
2393                       CatDecl->getClassInterface()->
2394                         getInstanceMethod(property->getGetterName());
2395
2396  SetterMethod = IsClassProperty ?
2397                 CD->getClassMethod(property->getSetterName()) :
2398                 CD->getInstanceMethod(property->getSetterName());
2399  if (!SetterMethod)
2400    if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD))
2401      if (CatDecl->IsClassExtension())
2402        SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2403                          getClassMethod(property->getSetterName()) :
2404                       CatDecl->getClassInterface()->
2405                          getInstanceMethod(property->getSetterName());
2406  DiagnosePropertyAccessorMismatch(property, GetterMethod,
2407                                   property->getLocation());
2408
2409  // synthesizing accessors must not result in a direct method that is not
2410  // monomorphic
2411  if (!GetterMethod) {
2412    if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD)) {
2413      auto *ExistingGetter = CatDecl->getClassInterface()->lookupMethod(
2414          property->getGetterName(), !IsClassProperty, true, false, CatDecl);
2415      if (ExistingGetter) {
2416        if (ExistingGetter->isDirectMethod() || property->isDirectProperty()) {
2417          Diag(property->getLocation(), diag::err_objc_direct_duplicate_decl)
2418              << property->isDirectProperty() << 1 /* property */
2419              << ExistingGetter->isDirectMethod()
2420              << ExistingGetter->getDeclName();
2421          Diag(ExistingGetter->getLocation(), diag::note_previous_declaration);
2422        }
2423      }
2424    }
2425  }
2426
2427  if (!property->isReadOnly() && !SetterMethod) {
2428    if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(CD)) {
2429      auto *ExistingSetter = CatDecl->getClassInterface()->lookupMethod(
2430          property->getSetterName(), !IsClassProperty, true, false, CatDecl);
2431      if (ExistingSetter) {
2432        if (ExistingSetter->isDirectMethod() || property->isDirectProperty()) {
2433          Diag(property->getLocation(), diag::err_objc_direct_duplicate_decl)
2434              << property->isDirectProperty() << 1 /* property */
2435              << ExistingSetter->isDirectMethod()
2436              << ExistingSetter->getDeclName();
2437          Diag(ExistingSetter->getLocation(), diag::note_previous_declaration);
2438        }
2439      }
2440    }
2441  }
2442
2443  if (!property->isReadOnly() && SetterMethod) {
2444    if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
2445        Context.VoidTy)
2446      Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2447    if (SetterMethod->param_size() != 1 ||
2448        !Context.hasSameUnqualifiedType(
2449          (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2450          property->getType().getNonReferenceType())) {
2451      Diag(property->getLocation(),
2452           diag::warn_accessor_property_type_mismatch)
2453        << property->getDeclName()
2454        << SetterMethod->getSelector();
2455      Diag(SetterMethod->getLocation(), diag::note_declared_at);
2456    }
2457  }
2458
2459  // Synthesize getter/setter methods if none exist.
2460  // Find the default getter and if one not found, add one.
2461  // FIXME: The synthesized property we set here is misleading. We almost always
2462  // synthesize these methods unless the user explicitly provided prototypes
2463  // (which is odd, but allowed). Sema should be typechecking that the
2464  // declarations jive in that situation (which it is not currently).
2465  if (!GetterMethod) {
2466    // No instance/class method of same name as property getter name was found.
2467    // Declare a getter method and add it to the list of methods
2468    // for this class.
2469    SourceLocation Loc = property->getLocation();
2470
2471    // The getter returns the declared property type with all qualifiers
2472    // removed.
2473    QualType resultTy = property->getType().getAtomicUnqualifiedType();
2474
2475    // If the property is null_resettable, the getter returns nonnull.
2476    if (property->getPropertyAttributes() &
2477        ObjCPropertyAttribute::kind_null_resettable) {
2478      QualType modifiedTy = resultTy;
2479      if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
2480        if (*nullability == NullabilityKind::Unspecified)
2481          resultTy = Context.getAttributedType(attr::TypeNonNull,
2482                                               modifiedTy, modifiedTy);
2483      }
2484    }
2485
2486    GetterMethod = ObjCMethodDecl::Create(
2487        Context, Loc, Loc, property->getGetterName(), resultTy, nullptr, CD,
2488        !IsClassProperty, /*isVariadic=*/false,
2489        /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
2490        /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2491        (property->getPropertyImplementation() == ObjCPropertyDecl::Optional)
2492            ? ObjCMethodDecl::Optional
2493            : ObjCMethodDecl::Required);
2494    CD->addDecl(GetterMethod);
2495
2496    AddPropertyAttrs(*this, GetterMethod, property);
2497
2498    if (property->isDirectProperty())
2499      GetterMethod->addAttr(ObjCDirectAttr::CreateImplicit(Context, Loc));
2500
2501    if (property->hasAttr<NSReturnsNotRetainedAttr>())
2502      GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2503                                                                     Loc));
2504
2505    if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2506      GetterMethod->addAttr(
2507        ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2508
2509    if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2510      GetterMethod->addAttr(SectionAttr::CreateImplicit(
2511          Context, SA->getName(), Loc, AttributeCommonInfo::AS_GNU,
2512          SectionAttr::GNU_section));
2513
2514    if (getLangOpts().ObjCAutoRefCount)
2515      CheckARCMethodDecl(GetterMethod);
2516  } else
2517    // A user declared getter will be synthesize when @synthesize of
2518    // the property with the same name is seen in the @implementation
2519    GetterMethod->setPropertyAccessor(true);
2520
2521  GetterMethod->createImplicitParams(Context,
2522                                     GetterMethod->getClassInterface());
2523  property->setGetterMethodDecl(GetterMethod);
2524
2525  // Skip setter if property is read-only.
2526  if (!property->isReadOnly()) {
2527    // Find the default setter and if one not found, add one.
2528    if (!SetterMethod) {
2529      // No instance/class method of same name as property setter name was
2530      // found.
2531      // Declare a setter method and add it to the list of methods
2532      // for this class.
2533      SourceLocation Loc = property->getLocation();
2534
2535      SetterMethod =
2536        ObjCMethodDecl::Create(Context, Loc, Loc,
2537                               property->getSetterName(), Context.VoidTy,
2538                               nullptr, CD, !IsClassProperty,
2539                               /*isVariadic=*/false,
2540                               /*isPropertyAccessor=*/true,
2541                               /*isSynthesizedAccessorStub=*/false,
2542                               /*isImplicitlyDeclared=*/true,
2543                               /*isDefined=*/false,
2544                               (property->getPropertyImplementation() ==
2545                                ObjCPropertyDecl::Optional) ?
2546                                ObjCMethodDecl::Optional :
2547                                ObjCMethodDecl::Required);
2548
2549      // Remove all qualifiers from the setter's parameter type.
2550      QualType paramTy =
2551          property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
2552
2553      // If the property is null_resettable, the setter accepts a
2554      // nullable value.
2555      if (property->getPropertyAttributes() &
2556          ObjCPropertyAttribute::kind_null_resettable) {
2557        QualType modifiedTy = paramTy;
2558        if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
2559          if (*nullability == NullabilityKind::Unspecified)
2560            paramTy = Context.getAttributedType(attr::TypeNullable,
2561                                                modifiedTy, modifiedTy);
2562        }
2563      }
2564
2565      // Invent the arguments for the setter. We don't bother making a
2566      // nice name for the argument.
2567      ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
2568                                                  Loc, Loc,
2569                                                  property->getIdentifier(),
2570                                                  paramTy,
2571                                                  /*TInfo=*/nullptr,
2572                                                  SC_None,
2573                                                  nullptr);
2574      SetterMethod->setMethodParams(Context, Argument, std::nullopt);
2575
2576      AddPropertyAttrs(*this, SetterMethod, property);
2577
2578      if (property->isDirectProperty())
2579        SetterMethod->addAttr(ObjCDirectAttr::CreateImplicit(Context, Loc));
2580
2581      CD->addDecl(SetterMethod);
2582      if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2583        SetterMethod->addAttr(SectionAttr::CreateImplicit(
2584            Context, SA->getName(), Loc, AttributeCommonInfo::AS_GNU,
2585            SectionAttr::GNU_section));
2586      // It's possible for the user to have set a very odd custom
2587      // setter selector that causes it to have a method family.
2588      if (getLangOpts().ObjCAutoRefCount)
2589        CheckARCMethodDecl(SetterMethod);
2590    } else
2591      // A user declared setter will be synthesize when @synthesize of
2592      // the property with the same name is seen in the @implementation
2593      SetterMethod->setPropertyAccessor(true);
2594
2595    SetterMethod->createImplicitParams(Context,
2596                                       SetterMethod->getClassInterface());
2597    property->setSetterMethodDecl(SetterMethod);
2598  }
2599  // Add any synthesized methods to the global pool. This allows us to
2600  // handle the following, which is supported by GCC (and part of the design).
2601  //
2602  // @interface Foo
2603  // @property double bar;
2604  // @end
2605  //
2606  // void thisIsUnfortunate() {
2607  //   id foo;
2608  //   double bar = [foo bar];
2609  // }
2610  //
2611  if (!IsClassProperty) {
2612    if (GetterMethod)
2613      AddInstanceMethodToGlobalPool(GetterMethod);
2614    if (SetterMethod)
2615      AddInstanceMethodToGlobalPool(SetterMethod);
2616  } else {
2617    if (GetterMethod)
2618      AddFactoryMethodToGlobalPool(GetterMethod);
2619    if (SetterMethod)
2620      AddFactoryMethodToGlobalPool(SetterMethod);
2621  }
2622
2623  ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(CD);
2624  if (!CurrentClass) {
2625    if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CD))
2626      CurrentClass = Cat->getClassInterface();
2627    else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(CD))
2628      CurrentClass = Impl->getClassInterface();
2629  }
2630  if (GetterMethod)
2631    CheckObjCMethodOverrides(GetterMethod, CurrentClass, Sema::RTC_Unknown);
2632  if (SetterMethod)
2633    CheckObjCMethodOverrides(SetterMethod, CurrentClass, Sema::RTC_Unknown);
2634}
2635
2636void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2637                                       SourceLocation Loc,
2638                                       unsigned &Attributes,
2639                                       bool propertyInPrimaryClass) {
2640  // FIXME: Improve the reported location.
2641  if (!PDecl || PDecl->isInvalidDecl())
2642    return;
2643
2644  if ((Attributes & ObjCPropertyAttribute::kind_readonly) &&
2645      (Attributes & ObjCPropertyAttribute::kind_readwrite))
2646    Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2647    << "readonly" << "readwrite";
2648
2649  ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(PDecl);
2650  QualType PropertyTy = PropertyDecl->getType();
2651
2652  // Check for copy or retain on non-object types.
2653  if ((Attributes &
2654       (ObjCPropertyAttribute::kind_weak | ObjCPropertyAttribute::kind_copy |
2655        ObjCPropertyAttribute::kind_retain |
2656        ObjCPropertyAttribute::kind_strong)) &&
2657      !PropertyTy->isObjCRetainableType() &&
2658      !PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2659    Diag(Loc, diag::err_objc_property_requires_object)
2660        << (Attributes & ObjCPropertyAttribute::kind_weak
2661                ? "weak"
2662                : Attributes & ObjCPropertyAttribute::kind_copy
2663                      ? "copy"
2664                      : "retain (or strong)");
2665    Attributes &=
2666        ~(ObjCPropertyAttribute::kind_weak | ObjCPropertyAttribute::kind_copy |
2667          ObjCPropertyAttribute::kind_retain |
2668          ObjCPropertyAttribute::kind_strong);
2669    PropertyDecl->setInvalidDecl();
2670  }
2671
2672  // Check for assign on object types.
2673  if ((Attributes & ObjCPropertyAttribute::kind_assign) &&
2674      !(Attributes & ObjCPropertyAttribute::kind_unsafe_unretained) &&
2675      PropertyTy->isObjCRetainableType() &&
2676      !PropertyTy->isObjCARCImplicitlyUnretainedType()) {
2677    Diag(Loc, diag::warn_objc_property_assign_on_object);
2678  }
2679
2680  // Check for more than one of { assign, copy, retain }.
2681  if (Attributes & ObjCPropertyAttribute::kind_assign) {
2682    if (Attributes & ObjCPropertyAttribute::kind_copy) {
2683      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2684        << "assign" << "copy";
2685      Attributes &= ~ObjCPropertyAttribute::kind_copy;
2686    }
2687    if (Attributes & ObjCPropertyAttribute::kind_retain) {
2688      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2689        << "assign" << "retain";
2690      Attributes &= ~ObjCPropertyAttribute::kind_retain;
2691    }
2692    if (Attributes & ObjCPropertyAttribute::kind_strong) {
2693      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2694        << "assign" << "strong";
2695      Attributes &= ~ObjCPropertyAttribute::kind_strong;
2696    }
2697    if (getLangOpts().ObjCAutoRefCount &&
2698        (Attributes & ObjCPropertyAttribute::kind_weak)) {
2699      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2700        << "assign" << "weak";
2701      Attributes &= ~ObjCPropertyAttribute::kind_weak;
2702    }
2703    if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2704      Diag(Loc, diag::warn_iboutletcollection_property_assign);
2705  } else if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained) {
2706    if (Attributes & ObjCPropertyAttribute::kind_copy) {
2707      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2708        << "unsafe_unretained" << "copy";
2709      Attributes &= ~ObjCPropertyAttribute::kind_copy;
2710    }
2711    if (Attributes & ObjCPropertyAttribute::kind_retain) {
2712      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2713        << "unsafe_unretained" << "retain";
2714      Attributes &= ~ObjCPropertyAttribute::kind_retain;
2715    }
2716    if (Attributes & ObjCPropertyAttribute::kind_strong) {
2717      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2718        << "unsafe_unretained" << "strong";
2719      Attributes &= ~ObjCPropertyAttribute::kind_strong;
2720    }
2721    if (getLangOpts().ObjCAutoRefCount &&
2722        (Attributes & ObjCPropertyAttribute::kind_weak)) {
2723      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2724        << "unsafe_unretained" << "weak";
2725      Attributes &= ~ObjCPropertyAttribute::kind_weak;
2726    }
2727  } else if (Attributes & ObjCPropertyAttribute::kind_copy) {
2728    if (Attributes & ObjCPropertyAttribute::kind_retain) {
2729      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2730        << "copy" << "retain";
2731      Attributes &= ~ObjCPropertyAttribute::kind_retain;
2732    }
2733    if (Attributes & ObjCPropertyAttribute::kind_strong) {
2734      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2735        << "copy" << "strong";
2736      Attributes &= ~ObjCPropertyAttribute::kind_strong;
2737    }
2738    if (Attributes & ObjCPropertyAttribute::kind_weak) {
2739      Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2740        << "copy" << "weak";
2741      Attributes &= ~ObjCPropertyAttribute::kind_weak;
2742    }
2743  } else if ((Attributes & ObjCPropertyAttribute::kind_retain) &&
2744             (Attributes & ObjCPropertyAttribute::kind_weak)) {
2745    Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "retain"
2746                                                               << "weak";
2747    Attributes &= ~ObjCPropertyAttribute::kind_retain;
2748  } else if ((Attributes & ObjCPropertyAttribute::kind_strong) &&
2749             (Attributes & ObjCPropertyAttribute::kind_weak)) {
2750    Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "strong"
2751                                                               << "weak";
2752    Attributes &= ~ObjCPropertyAttribute::kind_weak;
2753  }
2754
2755  if (Attributes & ObjCPropertyAttribute::kind_weak) {
2756    // 'weak' and 'nonnull' are mutually exclusive.
2757    if (auto nullability = PropertyTy->getNullability()) {
2758      if (*nullability == NullabilityKind::NonNull)
2759        Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2760          << "nonnull" << "weak";
2761    }
2762  }
2763
2764  if ((Attributes & ObjCPropertyAttribute::kind_atomic) &&
2765      (Attributes & ObjCPropertyAttribute::kind_nonatomic)) {
2766    Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "atomic"
2767                                                               << "nonatomic";
2768    Attributes &= ~ObjCPropertyAttribute::kind_atomic;
2769  }
2770
2771  // Warn if user supplied no assignment attribute, property is
2772  // readwrite, and this is an object type.
2773  if (!getOwnershipRule(Attributes) && PropertyTy->isObjCRetainableType()) {
2774    if (Attributes & ObjCPropertyAttribute::kind_readonly) {
2775      // do nothing
2776    } else if (getLangOpts().ObjCAutoRefCount) {
2777      // With arc, @property definitions should default to strong when
2778      // not specified.
2779      PropertyDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
2780    } else if (PropertyTy->isObjCObjectPointerType()) {
2781      bool isAnyClassTy = (PropertyTy->isObjCClassType() ||
2782                           PropertyTy->isObjCQualifiedClassType());
2783      // In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2784      // issue any warning.
2785      if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2786        ;
2787      else if (propertyInPrimaryClass) {
2788        // Don't issue warning on property with no life time in class
2789        // extension as it is inherited from property in primary class.
2790        // Skip this warning in gc-only mode.
2791        if (getLangOpts().getGC() != LangOptions::GCOnly)
2792          Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2793
2794        // If non-gc code warn that this is likely inappropriate.
2795        if (getLangOpts().getGC() == LangOptions::NonGC)
2796          Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2797      }
2798    }
2799
2800    // FIXME: Implement warning dependent on NSCopying being
2801    // implemented. See also:
2802    // <rdar://5168496&4855821&5607453&5096644&4947311&5698469&4947014&5168496>
2803    // (please trim this list while you are at it).
2804  }
2805
2806  if (!(Attributes & ObjCPropertyAttribute::kind_copy) &&
2807      !(Attributes & ObjCPropertyAttribute::kind_readonly) &&
2808      getLangOpts().getGC() == LangOptions::GCOnly &&
2809      PropertyTy->isBlockPointerType())
2810    Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2811  else if ((Attributes & ObjCPropertyAttribute::kind_retain) &&
2812           !(Attributes & ObjCPropertyAttribute::kind_readonly) &&
2813           !(Attributes & ObjCPropertyAttribute::kind_strong) &&
2814           PropertyTy->isBlockPointerType())
2815    Diag(Loc, diag::warn_objc_property_retain_of_block);
2816
2817  if ((Attributes & ObjCPropertyAttribute::kind_readonly) &&
2818      (Attributes & ObjCPropertyAttribute::kind_setter))
2819    Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2820}
2821