clang  15.0.0git
SemaDeclObjC.cpp
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1 //===--- SemaDeclObjC.cpp - Semantic Analysis for ObjC Declarations -------===//
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 declarations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "TypeLocBuilder.h"
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprObjC.h"
22 #include "clang/Basic/TargetInfo.h"
23 #include "clang/Sema/DeclSpec.h"
24 #include "clang/Sema/Lookup.h"
25 #include "clang/Sema/Scope.h"
26 #include "clang/Sema/ScopeInfo.h"
28 #include "llvm/ADT/DenseMap.h"
29 #include "llvm/ADT/DenseSet.h"
30 
31 using namespace clang;
32 
33 /// Check whether the given method, which must be in the 'init'
34 /// family, is a valid member of that family.
35 ///
36 /// \param receiverTypeIfCall - if null, check this as if declaring it;
37 /// if non-null, check this as if making a call to it with the given
38 /// receiver type
39 ///
40 /// \return true to indicate that there was an error and appropriate
41 /// actions were taken
43  QualType receiverTypeIfCall) {
44  if (method->isInvalidDecl()) return true;
45 
46  // This castAs is safe: methods that don't return an object
47  // pointer won't be inferred as inits and will reject an explicit
48  // objc_method_family(init).
49 
50  // We ignore protocols here. Should we? What about Class?
51 
52  const ObjCObjectType *result =
54 
55  if (result->isObjCId()) {
56  return false;
57  } else if (result->isObjCClass()) {
58  // fall through: always an error
59  } else {
60  ObjCInterfaceDecl *resultClass = result->getInterface();
61  assert(resultClass && "unexpected object type!");
62 
63  // It's okay for the result type to still be a forward declaration
64  // if we're checking an interface declaration.
65  if (!resultClass->hasDefinition()) {
66  if (receiverTypeIfCall.isNull() &&
67  !isa<ObjCImplementationDecl>(method->getDeclContext()))
68  return false;
69 
70  // Otherwise, we try to compare class types.
71  } else {
72  // If this method was declared in a protocol, we can't check
73  // anything unless we have a receiver type that's an interface.
74  const ObjCInterfaceDecl *receiverClass = nullptr;
75  if (isa<ObjCProtocolDecl>(method->getDeclContext())) {
76  if (receiverTypeIfCall.isNull())
77  return false;
78 
79  receiverClass = receiverTypeIfCall->castAs<ObjCObjectPointerType>()
80  ->getInterfaceDecl();
81 
82  // This can be null for calls to e.g. id<Foo>.
83  if (!receiverClass) return false;
84  } else {
85  receiverClass = method->getClassInterface();
86  assert(receiverClass && "method not associated with a class!");
87  }
88 
89  // If either class is a subclass of the other, it's fine.
90  if (receiverClass->isSuperClassOf(resultClass) ||
91  resultClass->isSuperClassOf(receiverClass))
92  return false;
93  }
94  }
95 
96  SourceLocation loc = method->getLocation();
97 
98  // If we're in a system header, and this is not a call, just make
99  // the method unusable.
100  if (receiverTypeIfCall.isNull() && getSourceManager().isInSystemHeader(loc)) {
101  method->addAttr(UnavailableAttr::CreateImplicit(Context, "",
102  UnavailableAttr::IR_ARCInitReturnsUnrelated, loc));
103  return true;
104  }
105 
106  // Otherwise, it's an error.
107  Diag(loc, diag::err_arc_init_method_unrelated_result_type);
108  method->setInvalidDecl();
109  return true;
110 }
111 
112 /// Issue a warning if the parameter of the overridden method is non-escaping
113 /// but the parameter of the overriding method is not.
114 static bool diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD,
115  Sema &S) {
116  if (OldD->hasAttr<NoEscapeAttr>() && !NewD->hasAttr<NoEscapeAttr>()) {
117  S.Diag(NewD->getLocation(), diag::warn_overriding_method_missing_noescape);
118  S.Diag(OldD->getLocation(), diag::note_overridden_marked_noescape);
119  return false;
120  }
121 
122  return true;
123 }
124 
125 /// Produce additional diagnostics if a category conforms to a protocol that
126 /// defines a method taking a non-escaping parameter.
127 static void diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD,
128  const ObjCCategoryDecl *CD,
129  const ObjCProtocolDecl *PD, Sema &S) {
130  if (!diagnoseNoescape(NewD, OldD, S))
131  S.Diag(CD->getLocation(), diag::note_cat_conform_to_noescape_prot)
132  << CD->IsClassExtension() << PD
133  << cast<ObjCMethodDecl>(NewD->getDeclContext());
134 }
135 
137  const ObjCMethodDecl *Overridden) {
138  if (Overridden->hasRelatedResultType() &&
139  !NewMethod->hasRelatedResultType()) {
140  // This can only happen when the method follows a naming convention that
141  // implies a related result type, and the original (overridden) method has
142  // a suitable return type, but the new (overriding) method does not have
143  // a suitable return type.
144  QualType ResultType = NewMethod->getReturnType();
145  SourceRange ResultTypeRange = NewMethod->getReturnTypeSourceRange();
146 
147  // Figure out which class this method is part of, if any.
148  ObjCInterfaceDecl *CurrentClass
149  = dyn_cast<ObjCInterfaceDecl>(NewMethod->getDeclContext());
150  if (!CurrentClass) {
151  DeclContext *DC = NewMethod->getDeclContext();
152  if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(DC))
153  CurrentClass = Cat->getClassInterface();
154  else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(DC))
155  CurrentClass = Impl->getClassInterface();
156  else if (ObjCCategoryImplDecl *CatImpl
157  = dyn_cast<ObjCCategoryImplDecl>(DC))
158  CurrentClass = CatImpl->getClassInterface();
159  }
160 
161  if (CurrentClass) {
162  Diag(NewMethod->getLocation(),
163  diag::warn_related_result_type_compatibility_class)
164  << Context.getObjCInterfaceType(CurrentClass)
165  << ResultType
166  << ResultTypeRange;
167  } else {
168  Diag(NewMethod->getLocation(),
169  diag::warn_related_result_type_compatibility_protocol)
170  << ResultType
171  << ResultTypeRange;
172  }
173 
174  if (ObjCMethodFamily Family = Overridden->getMethodFamily())
175  Diag(Overridden->getLocation(),
176  diag::note_related_result_type_family)
177  << /*overridden method*/ 0
178  << Family;
179  else
180  Diag(Overridden->getLocation(),
181  diag::note_related_result_type_overridden);
182  }
183 
184  if ((NewMethod->hasAttr<NSReturnsRetainedAttr>() !=
185  Overridden->hasAttr<NSReturnsRetainedAttr>())) {
186  Diag(NewMethod->getLocation(),
187  getLangOpts().ObjCAutoRefCount
188  ? diag::err_nsreturns_retained_attribute_mismatch
189  : diag::warn_nsreturns_retained_attribute_mismatch)
190  << 1;
191  Diag(Overridden->getLocation(), diag::note_previous_decl) << "method";
192  }
193  if ((NewMethod->hasAttr<NSReturnsNotRetainedAttr>() !=
194  Overridden->hasAttr<NSReturnsNotRetainedAttr>())) {
195  Diag(NewMethod->getLocation(),
196  getLangOpts().ObjCAutoRefCount
197  ? diag::err_nsreturns_retained_attribute_mismatch
198  : diag::warn_nsreturns_retained_attribute_mismatch)
199  << 0;
200  Diag(Overridden->getLocation(), diag::note_previous_decl) << "method";
201  }
202 
204  oe = Overridden->param_end();
205  for (ObjCMethodDecl::param_iterator ni = NewMethod->param_begin(),
206  ne = NewMethod->param_end();
207  ni != ne && oi != oe; ++ni, ++oi) {
208  const ParmVarDecl *oldDecl = (*oi);
209  ParmVarDecl *newDecl = (*ni);
210  if (newDecl->hasAttr<NSConsumedAttr>() !=
211  oldDecl->hasAttr<NSConsumedAttr>()) {
212  Diag(newDecl->getLocation(),
213  getLangOpts().ObjCAutoRefCount
214  ? diag::err_nsconsumed_attribute_mismatch
215  : diag::warn_nsconsumed_attribute_mismatch);
216  Diag(oldDecl->getLocation(), diag::note_previous_decl) << "parameter";
217  }
218 
219  diagnoseNoescape(newDecl, oldDecl, *this);
220  }
221 }
222 
223 /// Check a method declaration for compatibility with the Objective-C
224 /// ARC conventions.
226  ObjCMethodFamily family = method->getMethodFamily();
227  switch (family) {
228  case OMF_None:
229  case OMF_finalize:
230  case OMF_retain:
231  case OMF_release:
232  case OMF_autorelease:
233  case OMF_retainCount:
234  case OMF_self:
235  case OMF_initialize:
236  case OMF_performSelector:
237  return false;
238 
239  case OMF_dealloc:
240  if (!Context.hasSameType(method->getReturnType(), Context.VoidTy)) {
241  SourceRange ResultTypeRange = method->getReturnTypeSourceRange();
242  if (ResultTypeRange.isInvalid())
243  Diag(method->getLocation(), diag::err_dealloc_bad_result_type)
244  << method->getReturnType()
245  << FixItHint::CreateInsertion(method->getSelectorLoc(0), "(void)");
246  else
247  Diag(method->getLocation(), diag::err_dealloc_bad_result_type)
248  << method->getReturnType()
249  << FixItHint::CreateReplacement(ResultTypeRange, "void");
250  return true;
251  }
252  return false;
253 
254  case OMF_init:
255  // If the method doesn't obey the init rules, don't bother annotating it.
256  if (checkInitMethod(method, QualType()))
257  return true;
258 
259  method->addAttr(NSConsumesSelfAttr::CreateImplicit(Context));
260 
261  // Don't add a second copy of this attribute, but otherwise don't
262  // let it be suppressed.
263  if (method->hasAttr<NSReturnsRetainedAttr>())
264  return false;
265  break;
266 
267  case OMF_alloc:
268  case OMF_copy:
269  case OMF_mutableCopy:
270  case OMF_new:
271  if (method->hasAttr<NSReturnsRetainedAttr>() ||
272  method->hasAttr<NSReturnsNotRetainedAttr>() ||
273  method->hasAttr<NSReturnsAutoreleasedAttr>())
274  return false;
275  break;
276  }
277 
278  method->addAttr(NSReturnsRetainedAttr::CreateImplicit(Context));
279  return false;
280 }
281 
283  SourceLocation ImplLoc) {
284  if (!ND)
285  return;
286  bool IsCategory = false;
287  StringRef RealizedPlatform;
288  AvailabilityResult Availability = ND->getAvailability(
289  /*Message=*/nullptr, /*EnclosingVersion=*/VersionTuple(),
290  &RealizedPlatform);
291  if (Availability != AR_Deprecated) {
292  if (isa<ObjCMethodDecl>(ND)) {
293  if (Availability != AR_Unavailable)
294  return;
295  if (RealizedPlatform.empty())
296  RealizedPlatform = S.Context.getTargetInfo().getPlatformName();
297  // Warn about implementing unavailable methods, unless the unavailable
298  // is for an app extension.
299  if (RealizedPlatform.endswith("_app_extension"))
300  return;
301  S.Diag(ImplLoc, diag::warn_unavailable_def);
302  S.Diag(ND->getLocation(), diag::note_method_declared_at)
303  << ND->getDeclName();
304  return;
305  }
306  if (const auto *CD = dyn_cast<ObjCCategoryDecl>(ND)) {
307  if (!CD->getClassInterface()->isDeprecated())
308  return;
309  ND = CD->getClassInterface();
310  IsCategory = true;
311  } else
312  return;
313  }
314  S.Diag(ImplLoc, diag::warn_deprecated_def)
315  << (isa<ObjCMethodDecl>(ND)
316  ? /*Method*/ 0
317  : isa<ObjCCategoryDecl>(ND) || IsCategory ? /*Category*/ 2
318  : /*Class*/ 1);
319  if (isa<ObjCMethodDecl>(ND))
320  S.Diag(ND->getLocation(), diag::note_method_declared_at)
321  << ND->getDeclName();
322  else
323  S.Diag(ND->getLocation(), diag::note_previous_decl)
324  << (isa<ObjCCategoryDecl>(ND) ? "category" : "class");
325 }
326 
327 /// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
328 /// pool.
330  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
331 
332  // If we don't have a valid method decl, simply return.
333  if (!MDecl)
334  return;
335  if (MDecl->isInstanceMethod())
336  AddInstanceMethodToGlobalPool(MDecl, true);
337  else
338  AddFactoryMethodToGlobalPool(MDecl, true);
339 }
340 
341 /// HasExplicitOwnershipAttr - returns true when pointer to ObjC pointer
342 /// has explicit ownership attribute; false otherwise.
343 static bool
345  QualType T = Param->getType();
346 
347  if (const PointerType *PT = T->getAs<PointerType>()) {
348  T = PT->getPointeeType();
349  } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
350  T = RT->getPointeeType();
351  } else {
352  return true;
353  }
354 
355  // If we have a lifetime qualifier, but it's local, we must have
356  // inferred it. So, it is implicit.
357  return !T.getLocalQualifiers().hasObjCLifetime();
358 }
359 
360 /// ActOnStartOfObjCMethodDef - This routine sets up parameters; invisible
361 /// and user declared, in the method definition's AST.
364  assert((getCurMethodDecl() == nullptr) && "Methodparsing confused");
365  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
366 
368 
369  // If we don't have a valid method decl, simply return.
370  if (!MDecl)
371  return;
372 
373  QualType ResultType = MDecl->getReturnType();
374  if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
375  !MDecl->isInvalidDecl() &&
376  RequireCompleteType(MDecl->getLocation(), ResultType,
377  diag::err_func_def_incomplete_result))
378  MDecl->setInvalidDecl();
379 
380  // Allow all of Sema to see that we are entering a method definition.
381  PushDeclContext(FnBodyScope, MDecl);
383 
384  // Create Decl objects for each parameter, entrring them in the scope for
385  // binding to their use.
386 
387  // Insert the invisible arguments, self and _cmd!
389 
390  PushOnScopeChains(MDecl->getSelfDecl(), FnBodyScope);
391  PushOnScopeChains(MDecl->getCmdDecl(), FnBodyScope);
392 
393  // The ObjC parser requires parameter names so there's no need to check.
395  /*CheckParameterNames=*/false);
396 
397  // Introduce all of the other parameters into this scope.
398  for (auto *Param : MDecl->parameters()) {
399  if (!Param->isInvalidDecl() &&
400  getLangOpts().ObjCAutoRefCount &&
401  !HasExplicitOwnershipAttr(*this, Param))
402  Diag(Param->getLocation(), diag::warn_arc_strong_pointer_objc_pointer) <<
403  Param->getType();
404 
405  if (Param->getIdentifier())
406  PushOnScopeChains(Param, FnBodyScope);
407  }
408 
409  // In ARC, disallow definition of retain/release/autorelease/retainCount
410  if (getLangOpts().ObjCAutoRefCount) {
411  switch (MDecl->getMethodFamily()) {
412  case OMF_retain:
413  case OMF_retainCount:
414  case OMF_release:
415  case OMF_autorelease:
416  Diag(MDecl->getLocation(), diag::err_arc_illegal_method_def)
417  << 0 << MDecl->getSelector();
418  break;
419 
420  case OMF_None:
421  case OMF_dealloc:
422  case OMF_finalize:
423  case OMF_alloc:
424  case OMF_init:
425  case OMF_mutableCopy:
426  case OMF_copy:
427  case OMF_new:
428  case OMF_self:
429  case OMF_initialize:
430  case OMF_performSelector:
431  break;
432  }
433  }
434 
435  // Warn on deprecated methods under -Wdeprecated-implementations,
436  // and prepare for warning on missing super calls.
437  if (ObjCInterfaceDecl *IC = MDecl->getClassInterface()) {
438  ObjCMethodDecl *IMD =
439  IC->lookupMethod(MDecl->getSelector(), MDecl->isInstanceMethod());
440 
441  if (IMD) {
442  ObjCImplDecl *ImplDeclOfMethodDef =
443  dyn_cast<ObjCImplDecl>(MDecl->getDeclContext());
444  ObjCContainerDecl *ContDeclOfMethodDecl =
445  dyn_cast<ObjCContainerDecl>(IMD->getDeclContext());
446  ObjCImplDecl *ImplDeclOfMethodDecl = nullptr;
447  if (ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(ContDeclOfMethodDecl))
448  ImplDeclOfMethodDecl = OID->getImplementation();
449  else if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContDeclOfMethodDecl)) {
450  if (CD->IsClassExtension()) {
451  if (ObjCInterfaceDecl *OID = CD->getClassInterface())
452  ImplDeclOfMethodDecl = OID->getImplementation();
453  } else
454  ImplDeclOfMethodDecl = CD->getImplementation();
455  }
456  // No need to issue deprecated warning if deprecated mehod in class/category
457  // is being implemented in its own implementation (no overriding is involved).
458  if (!ImplDeclOfMethodDecl || ImplDeclOfMethodDecl != ImplDeclOfMethodDef)
459  DiagnoseObjCImplementedDeprecations(*this, IMD, MDecl->getLocation());
460  }
461 
462  if (MDecl->getMethodFamily() == OMF_init) {
466  IC->getSuperClass() != nullptr;
467  } else if (IC->hasDesignatedInitializers()) {
470  }
471  }
472 
473  // If this is "dealloc" or "finalize", set some bit here.
474  // Then in ActOnSuperMessage() (SemaExprObjC), set it back to false.
475  // Finally, in ActOnFinishFunctionBody() (SemaDecl), warn if flag is set.
476  // Only do this if the current class actually has a superclass.
477  if (const ObjCInterfaceDecl *SuperClass = IC->getSuperClass()) {
478  ObjCMethodFamily Family = MDecl->getMethodFamily();
479  if (Family == OMF_dealloc) {
480  if (!(getLangOpts().ObjCAutoRefCount ||
481  getLangOpts().getGC() == LangOptions::GCOnly))
483 
484  } else if (Family == OMF_finalize) {
485  if (Context.getLangOpts().getGC() != LangOptions::NonGC)
487 
488  } else {
489  const ObjCMethodDecl *SuperMethod =
490  SuperClass->lookupMethod(MDecl->getSelector(),
491  MDecl->isInstanceMethod());
493  (SuperMethod && SuperMethod->hasAttr<ObjCRequiresSuperAttr>());
494  }
495  }
496  }
497 }
498 
499 namespace {
500 
501 // Callback to only accept typo corrections that are Objective-C classes.
502 // If an ObjCInterfaceDecl* is given to the constructor, then the validation
503 // function will reject corrections to that class.
504 class ObjCInterfaceValidatorCCC final : public CorrectionCandidateCallback {
505  public:
506  ObjCInterfaceValidatorCCC() : CurrentIDecl(nullptr) {}
507  explicit ObjCInterfaceValidatorCCC(ObjCInterfaceDecl *IDecl)
508  : CurrentIDecl(IDecl) {}
509 
510  bool ValidateCandidate(const TypoCorrection &candidate) override {
512  return ID && !declaresSameEntity(ID, CurrentIDecl);
513  }
514 
515  std::unique_ptr<CorrectionCandidateCallback> clone() override {
516  return std::make_unique<ObjCInterfaceValidatorCCC>(*this);
517  }
518 
519  private:
520  ObjCInterfaceDecl *CurrentIDecl;
521 };
522 
523 } // end anonymous namespace
524 
525 static void diagnoseUseOfProtocols(Sema &TheSema,
526  ObjCContainerDecl *CD,
527  ObjCProtocolDecl *const *ProtoRefs,
528  unsigned NumProtoRefs,
529  const SourceLocation *ProtoLocs) {
530  assert(ProtoRefs);
531  // Diagnose availability in the context of the ObjC container.
532  Sema::ContextRAII SavedContext(TheSema, CD);
533  for (unsigned i = 0; i < NumProtoRefs; ++i) {
534  (void)TheSema.DiagnoseUseOfDecl(ProtoRefs[i], ProtoLocs[i],
535  /*UnknownObjCClass=*/nullptr,
536  /*ObjCPropertyAccess=*/false,
537  /*AvoidPartialAvailabilityChecks=*/true);
538  }
539 }
540 
541 void Sema::
543  SourceLocation AtInterfaceLoc,
544  ObjCInterfaceDecl *IDecl,
545  IdentifierInfo *ClassName,
546  SourceLocation ClassLoc,
547  IdentifierInfo *SuperName,
548  SourceLocation SuperLoc,
549  ArrayRef<ParsedType> SuperTypeArgs,
550  SourceRange SuperTypeArgsRange) {
551  // Check if a different kind of symbol declared in this scope.
552  NamedDecl *PrevDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
554 
555  if (!PrevDecl) {
556  // Try to correct for a typo in the superclass name without correcting
557  // to the class we're defining.
558  ObjCInterfaceValidatorCCC CCC(IDecl);
559  if (TypoCorrection Corrected = CorrectTypo(
560  DeclarationNameInfo(SuperName, SuperLoc), LookupOrdinaryName,
561  TUScope, nullptr, CCC, CTK_ErrorRecovery)) {
562  diagnoseTypo(Corrected, PDiag(diag::err_undef_superclass_suggest)
563  << SuperName << ClassName);
564  PrevDecl = Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>();
565  }
566  }
567 
568  if (declaresSameEntity(PrevDecl, IDecl)) {
569  Diag(SuperLoc, diag::err_recursive_superclass)
570  << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
571  IDecl->setEndOfDefinitionLoc(ClassLoc);
572  } else {
573  ObjCInterfaceDecl *SuperClassDecl =
574  dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
575  QualType SuperClassType;
576 
577  // Diagnose classes that inherit from deprecated classes.
578  if (SuperClassDecl) {
579  (void)DiagnoseUseOfDecl(SuperClassDecl, SuperLoc);
580  SuperClassType = Context.getObjCInterfaceType(SuperClassDecl);
581  }
582 
583  if (PrevDecl && !SuperClassDecl) {
584  // The previous declaration was not a class decl. Check if we have a
585  // typedef. If we do, get the underlying class type.
586  if (const TypedefNameDecl *TDecl =
587  dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) {
588  QualType T = TDecl->getUnderlyingType();
589  if (T->isObjCObjectType()) {
590  if (NamedDecl *IDecl = T->castAs<ObjCObjectType>()->getInterface()) {
591  SuperClassDecl = dyn_cast<ObjCInterfaceDecl>(IDecl);
592  SuperClassType = Context.getTypeDeclType(TDecl);
593 
594  // This handles the following case:
595  // @interface NewI @end
596  // typedef NewI DeprI __attribute__((deprecated("blah")))
597  // @interface SI : DeprI /* warn here */ @end
598  (void)DiagnoseUseOfDecl(const_cast<TypedefNameDecl*>(TDecl), SuperLoc);
599  }
600  }
601  }
602 
603  // This handles the following case:
604  //
605  // typedef int SuperClass;
606  // @interface MyClass : SuperClass {} @end
607  //
608  if (!SuperClassDecl) {
609  Diag(SuperLoc, diag::err_redefinition_different_kind) << SuperName;
610  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
611  }
612  }
613 
614  if (!isa_and_nonnull<TypedefNameDecl>(PrevDecl)) {
615  if (!SuperClassDecl)
616  Diag(SuperLoc, diag::err_undef_superclass)
617  << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
618  else if (RequireCompleteType(SuperLoc,
619  SuperClassType,
620  diag::err_forward_superclass,
621  SuperClassDecl->getDeclName(),
622  ClassName,
623  SourceRange(AtInterfaceLoc, ClassLoc))) {
624  SuperClassDecl = nullptr;
625  SuperClassType = QualType();
626  }
627  }
628 
629  if (SuperClassType.isNull()) {
630  assert(!SuperClassDecl && "Failed to set SuperClassType?");
631  return;
632  }
633 
634  // Handle type arguments on the superclass.
635  TypeSourceInfo *SuperClassTInfo = nullptr;
636  if (!SuperTypeArgs.empty()) {
638  S,
639  SuperLoc,
640  CreateParsedType(SuperClassType,
641  nullptr),
642  SuperTypeArgsRange.getBegin(),
643  SuperTypeArgs,
644  SuperTypeArgsRange.getEnd(),
645  SourceLocation(),
646  { },
647  { },
648  SourceLocation());
649  if (!fullSuperClassType.isUsable())
650  return;
651 
652  SuperClassType = GetTypeFromParser(fullSuperClassType.get(),
653  &SuperClassTInfo);
654  }
655 
656  if (!SuperClassTInfo) {
657  SuperClassTInfo = Context.getTrivialTypeSourceInfo(SuperClassType,
658  SuperLoc);
659  }
660 
661  IDecl->setSuperClass(SuperClassTInfo);
662  IDecl->setEndOfDefinitionLoc(SuperClassTInfo->getTypeLoc().getEndLoc());
663  }
664 }
665 
667  ObjCTypeParamVariance variance,
668  SourceLocation varianceLoc,
669  unsigned index,
670  IdentifierInfo *paramName,
671  SourceLocation paramLoc,
672  SourceLocation colonLoc,
673  ParsedType parsedTypeBound) {
674  // If there was an explicitly-provided type bound, check it.
675  TypeSourceInfo *typeBoundInfo = nullptr;
676  if (parsedTypeBound) {
677  // The type bound can be any Objective-C pointer type.
678  QualType typeBound = GetTypeFromParser(parsedTypeBound, &typeBoundInfo);
679  if (typeBound->isObjCObjectPointerType()) {
680  // okay
681  } else if (typeBound->isObjCObjectType()) {
682  // The user forgot the * on an Objective-C pointer type, e.g.,
683  // "T : NSView".
685  typeBoundInfo->getTypeLoc().getEndLoc());
686  Diag(typeBoundInfo->getTypeLoc().getBeginLoc(),
687  diag::err_objc_type_param_bound_missing_pointer)
688  << typeBound << paramName
689  << FixItHint::CreateInsertion(starLoc, " *");
690 
691  // Create a new type location builder so we can update the type
692  // location information we have.
693  TypeLocBuilder builder;
694  builder.pushFullCopy(typeBoundInfo->getTypeLoc());
695 
696  // Create the Objective-C pointer type.
697  typeBound = Context.getObjCObjectPointerType(typeBound);
699  = builder.push<ObjCObjectPointerTypeLoc>(typeBound);
700  newT.setStarLoc(starLoc);
701 
702  // Form the new type source information.
703  typeBoundInfo = builder.getTypeSourceInfo(Context, typeBound);
704  } else {
705  // Not a valid type bound.
706  Diag(typeBoundInfo->getTypeLoc().getBeginLoc(),
707  diag::err_objc_type_param_bound_nonobject)
708  << typeBound << paramName;
709 
710  // Forget the bound; we'll default to id later.
711  typeBoundInfo = nullptr;
712  }
713 
714  // Type bounds cannot have qualifiers (even indirectly) or explicit
715  // nullability.
716  if (typeBoundInfo) {
717  QualType typeBound = typeBoundInfo->getType();
718  TypeLoc qual = typeBoundInfo->getTypeLoc().findExplicitQualifierLoc();
719  if (qual || typeBound.hasQualifiers()) {
720  bool diagnosed = false;
721  SourceRange rangeToRemove;
722  if (qual) {
723  if (auto attr = qual.getAs<AttributedTypeLoc>()) {
724  rangeToRemove = attr.getLocalSourceRange();
725  if (attr.getTypePtr()->getImmediateNullability()) {
726  Diag(attr.getBeginLoc(),
727  diag::err_objc_type_param_bound_explicit_nullability)
728  << paramName << typeBound
729  << FixItHint::CreateRemoval(rangeToRemove);
730  diagnosed = true;
731  }
732  }
733  }
734 
735  if (!diagnosed) {
736  Diag(qual ? qual.getBeginLoc()
737  : typeBoundInfo->getTypeLoc().getBeginLoc(),
738  diag::err_objc_type_param_bound_qualified)
739  << paramName << typeBound
740  << typeBound.getQualifiers().getAsString()
741  << FixItHint::CreateRemoval(rangeToRemove);
742  }
743 
744  // If the type bound has qualifiers other than CVR, we need to strip
745  // them or we'll probably assert later when trying to apply new
746  // qualifiers.
747  Qualifiers quals = typeBound.getQualifiers();
748  quals.removeCVRQualifiers();
749  if (!quals.empty()) {
750  typeBoundInfo =
752  }
753  }
754  }
755  }
756 
757  // If there was no explicit type bound (or we removed it due to an error),
758  // use 'id' instead.
759  if (!typeBoundInfo) {
760  colonLoc = SourceLocation();
762  }
763 
764  // Create the type parameter.
765  return ObjCTypeParamDecl::Create(Context, CurContext, variance, varianceLoc,
766  index, paramLoc, paramName, colonLoc,
767  typeBoundInfo);
768 }
769 
771  SourceLocation lAngleLoc,
772  ArrayRef<Decl *> typeParamsIn,
773  SourceLocation rAngleLoc) {
774  // We know that the array only contains Objective-C type parameters.
776  typeParams(
777  reinterpret_cast<ObjCTypeParamDecl * const *>(typeParamsIn.data()),
778  typeParamsIn.size());
779 
780  // Diagnose redeclarations of type parameters.
781  // We do this now because Objective-C type parameters aren't pushed into
782  // scope until later (after the instance variable block), but we want the
783  // diagnostics to occur right after we parse the type parameter list.
784  llvm::SmallDenseMap<IdentifierInfo *, ObjCTypeParamDecl *> knownParams;
785  for (auto typeParam : typeParams) {
786  auto known = knownParams.find(typeParam->getIdentifier());
787  if (known != knownParams.end()) {
788  Diag(typeParam->getLocation(), diag::err_objc_type_param_redecl)
789  << typeParam->getIdentifier()
790  << SourceRange(known->second->getLocation());
791 
792  typeParam->setInvalidDecl();
793  } else {
794  knownParams.insert(std::make_pair(typeParam->getIdentifier(), typeParam));
795 
796  // Push the type parameter into scope.
797  PushOnScopeChains(typeParam, S, /*AddToContext=*/false);
798  }
799  }
800 
801  // Create the parameter list.
802  return ObjCTypeParamList::create(Context, lAngleLoc, typeParams, rAngleLoc);
803 }
804 
806  for (auto typeParam : *typeParamList) {
807  if (!typeParam->isInvalidDecl()) {
808  S->RemoveDecl(typeParam);
809  IdResolver.RemoveDecl(typeParam);
810  }
811  }
812 }
813 
814 namespace {
815  /// The context in which an Objective-C type parameter list occurs, for use
816  /// in diagnostics.
817  enum class TypeParamListContext {
818  ForwardDeclaration,
819  Definition,
820  Category,
821  Extension
822  };
823 } // end anonymous namespace
824 
825 /// Check consistency between two Objective-C type parameter lists, e.g.,
826 /// between a category/extension and an \@interface or between an \@class and an
827 /// \@interface.
829  ObjCTypeParamList *prevTypeParams,
830  ObjCTypeParamList *newTypeParams,
831  TypeParamListContext newContext) {
832  // If the sizes don't match, complain about that.
833  if (prevTypeParams->size() != newTypeParams->size()) {
834  SourceLocation diagLoc;
835  if (newTypeParams->size() > prevTypeParams->size()) {
836  diagLoc = newTypeParams->begin()[prevTypeParams->size()]->getLocation();
837  } else {
838  diagLoc = S.getLocForEndOfToken(newTypeParams->back()->getEndLoc());
839  }
840 
841  S.Diag(diagLoc, diag::err_objc_type_param_arity_mismatch)
842  << static_cast<unsigned>(newContext)
843  << (newTypeParams->size() > prevTypeParams->size())
844  << prevTypeParams->size()
845  << newTypeParams->size();
846 
847  return true;
848  }
849 
850  // Match up the type parameters.
851  for (unsigned i = 0, n = prevTypeParams->size(); i != n; ++i) {
852  ObjCTypeParamDecl *prevTypeParam = prevTypeParams->begin()[i];
853  ObjCTypeParamDecl *newTypeParam = newTypeParams->begin()[i];
854 
855  // Check for consistency of the variance.
856  if (newTypeParam->getVariance() != prevTypeParam->getVariance()) {
857  if (newTypeParam->getVariance() == ObjCTypeParamVariance::Invariant &&
858  newContext != TypeParamListContext::Definition) {
859  // When the new type parameter is invariant and is not part
860  // of the definition, just propagate the variance.
861  newTypeParam->setVariance(prevTypeParam->getVariance());
862  } else if (prevTypeParam->getVariance()
864  !(isa<ObjCInterfaceDecl>(prevTypeParam->getDeclContext()) &&
865  cast<ObjCInterfaceDecl>(prevTypeParam->getDeclContext())
866  ->getDefinition() == prevTypeParam->getDeclContext())) {
867  // When the old parameter is invariant and was not part of the
868  // definition, just ignore the difference because it doesn't
869  // matter.
870  } else {
871  {
872  // Diagnose the conflict and update the second declaration.
873  SourceLocation diagLoc = newTypeParam->getVarianceLoc();
874  if (diagLoc.isInvalid())
875  diagLoc = newTypeParam->getBeginLoc();
876 
877  auto diag = S.Diag(diagLoc,
878  diag::err_objc_type_param_variance_conflict)
879  << static_cast<unsigned>(newTypeParam->getVariance())
880  << newTypeParam->getDeclName()
881  << static_cast<unsigned>(prevTypeParam->getVariance())
882  << prevTypeParam->getDeclName();
883  switch (prevTypeParam->getVariance()) {
885  diag << FixItHint::CreateRemoval(newTypeParam->getVarianceLoc());
886  break;
887 
890  StringRef newVarianceStr
891  = prevTypeParam->getVariance() == ObjCTypeParamVariance::Covariant
892  ? "__covariant"
893  : "__contravariant";
894  if (newTypeParam->getVariance()
896  diag << FixItHint::CreateInsertion(newTypeParam->getBeginLoc(),
897  (newVarianceStr + " ").str());
898  } else {
899  diag << FixItHint::CreateReplacement(newTypeParam->getVarianceLoc(),
900  newVarianceStr);
901  }
902  }
903  }
904  }
905 
906  S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
907  << prevTypeParam->getDeclName();
908 
909  // Override the variance.
910  newTypeParam->setVariance(prevTypeParam->getVariance());
911  }
912  }
913 
914  // If the bound types match, there's nothing to do.
915  if (S.Context.hasSameType(prevTypeParam->getUnderlyingType(),
916  newTypeParam->getUnderlyingType()))
917  continue;
918 
919  // If the new type parameter's bound was explicit, complain about it being
920  // different from the original.
921  if (newTypeParam->hasExplicitBound()) {
922  SourceRange newBoundRange = newTypeParam->getTypeSourceInfo()
924  S.Diag(newBoundRange.getBegin(), diag::err_objc_type_param_bound_conflict)
925  << newTypeParam->getUnderlyingType()
926  << newTypeParam->getDeclName()
927  << prevTypeParam->hasExplicitBound()
928  << prevTypeParam->getUnderlyingType()
929  << (newTypeParam->getDeclName() == prevTypeParam->getDeclName())
930  << prevTypeParam->getDeclName()
932  newBoundRange,
933  prevTypeParam->getUnderlyingType().getAsString(
935 
936  S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
937  << prevTypeParam->getDeclName();
938 
939  // Override the new type parameter's bound type with the previous type,
940  // so that it's consistent.
941  S.Context.adjustObjCTypeParamBoundType(prevTypeParam, newTypeParam);
942  continue;
943  }
944 
945  // The new type parameter got the implicit bound of 'id'. That's okay for
946  // categories and extensions (overwrite it later), but not for forward
947  // declarations and @interfaces, because those must be standalone.
948  if (newContext == TypeParamListContext::ForwardDeclaration ||
949  newContext == TypeParamListContext::Definition) {
950  // Diagnose this problem for forward declarations and definitions.
951  SourceLocation insertionLoc
952  = S.getLocForEndOfToken(newTypeParam->getLocation());
953  std::string newCode
954  = " : " + prevTypeParam->getUnderlyingType().getAsString(
956  S.Diag(newTypeParam->getLocation(),
957  diag::err_objc_type_param_bound_missing)
958  << prevTypeParam->getUnderlyingType()
959  << newTypeParam->getDeclName()
960  << (newContext == TypeParamListContext::ForwardDeclaration)
961  << FixItHint::CreateInsertion(insertionLoc, newCode);
962 
963  S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here)
964  << prevTypeParam->getDeclName();
965  }
966 
967  // Update the new type parameter's bound to match the previous one.
968  S.Context.adjustObjCTypeParamBoundType(prevTypeParam, newTypeParam);
969  }
970 
971  return false;
972 }
973 
975  Scope *S, SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
976  SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
977  IdentifierInfo *SuperName, SourceLocation SuperLoc,
978  ArrayRef<ParsedType> SuperTypeArgs, SourceRange SuperTypeArgsRange,
979  Decl *const *ProtoRefs, unsigned NumProtoRefs,
980  const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
981  const ParsedAttributesView &AttrList) {
982  assert(ClassName && "Missing class identifier");
983 
984  // Check for another declaration kind with the same name.
985  NamedDecl *PrevDecl =
986  LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
988 
989  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
990  Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
991  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
992  }
993 
994  // Create a declaration to describe this @interface.
995  ObjCInterfaceDecl* PrevIDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
996 
997  if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) {
998  // A previous decl with a different name is because of
999  // @compatibility_alias, for example:
1000  // \code
1001  // @class NewImage;
1002  // @compatibility_alias OldImage NewImage;
1003  // \endcode
1004  // A lookup for 'OldImage' will return the 'NewImage' decl.
1005  //
1006  // In such a case use the real declaration name, instead of the alias one,
1007  // otherwise we will break IdentifierResolver and redecls-chain invariants.
1008  // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl
1009  // has been aliased.
1010  ClassName = PrevIDecl->getIdentifier();
1011  }
1012 
1013  // If there was a forward declaration with type parameters, check
1014  // for consistency.
1015  if (PrevIDecl) {
1016  if (ObjCTypeParamList *prevTypeParamList = PrevIDecl->getTypeParamList()) {
1017  if (typeParamList) {
1018  // Both have type parameter lists; check for consistency.
1019  if (checkTypeParamListConsistency(*this, prevTypeParamList,
1020  typeParamList,
1021  TypeParamListContext::Definition)) {
1022  typeParamList = nullptr;
1023  }
1024  } else {
1025  Diag(ClassLoc, diag::err_objc_parameterized_forward_class_first)
1026  << ClassName;
1027  Diag(prevTypeParamList->getLAngleLoc(), diag::note_previous_decl)
1028  << ClassName;
1029 
1030  // Clone the type parameter list.
1031  SmallVector<ObjCTypeParamDecl *, 4> clonedTypeParams;
1032  for (auto typeParam : *prevTypeParamList) {
1033  clonedTypeParams.push_back(
1035  Context,
1036  CurContext,
1037  typeParam->getVariance(),
1038  SourceLocation(),
1039  typeParam->getIndex(),
1040  SourceLocation(),
1041  typeParam->getIdentifier(),
1042  SourceLocation(),
1043  Context.getTrivialTypeSourceInfo(typeParam->getUnderlyingType())));
1044  }
1045 
1046  typeParamList = ObjCTypeParamList::create(Context,
1047  SourceLocation(),
1048  clonedTypeParams,
1049  SourceLocation());
1050  }
1051  }
1052  }
1053 
1054  ObjCInterfaceDecl *IDecl
1055  = ObjCInterfaceDecl::Create(Context, CurContext, AtInterfaceLoc, ClassName,
1056  typeParamList, PrevIDecl, ClassLoc);
1057  if (PrevIDecl) {
1058  // Class already seen. Was it a definition?
1059  if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
1060  Diag(AtInterfaceLoc, diag::err_duplicate_class_def)
1061  << PrevIDecl->getDeclName();
1062  Diag(Def->getLocation(), diag::note_previous_definition);
1063  IDecl->setInvalidDecl();
1064  }
1065  }
1066 
1067  ProcessDeclAttributeList(TUScope, IDecl, AttrList);
1068  AddPragmaAttributes(TUScope, IDecl);
1069 
1070  // Merge attributes from previous declarations.
1071  if (PrevIDecl)
1072  mergeDeclAttributes(IDecl, PrevIDecl);
1073 
1074  PushOnScopeChains(IDecl, TUScope);
1075 
1076  // Start the definition of this class. If we're in a redefinition case, there
1077  // may already be a definition, so we'll end up adding to it.
1078  if (!IDecl->hasDefinition())
1079  IDecl->startDefinition();
1080 
1081  if (SuperName) {
1082  // Diagnose availability in the context of the @interface.
1083  ContextRAII SavedContext(*this, IDecl);
1084 
1085  ActOnSuperClassOfClassInterface(S, AtInterfaceLoc, IDecl,
1086  ClassName, ClassLoc,
1087  SuperName, SuperLoc, SuperTypeArgs,
1088  SuperTypeArgsRange);
1089  } else { // we have a root class.
1090  IDecl->setEndOfDefinitionLoc(ClassLoc);
1091  }
1092 
1093  // Check then save referenced protocols.
1094  if (NumProtoRefs) {
1095  diagnoseUseOfProtocols(*this, IDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1096  NumProtoRefs, ProtoLocs);
1097  IDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1098  ProtoLocs, Context);
1099  IDecl->setEndOfDefinitionLoc(EndProtoLoc);
1100  }
1101 
1102  CheckObjCDeclScope(IDecl);
1104  return IDecl;
1105 }
1106 
1107 /// ActOnTypedefedProtocols - this action finds protocol list as part of the
1108 /// typedef'ed use for a qualified super class and adds them to the list
1109 /// of the protocols.
1111  SmallVectorImpl<SourceLocation> &ProtocolLocs,
1112  IdentifierInfo *SuperName,
1113  SourceLocation SuperLoc) {
1114  if (!SuperName)
1115  return;
1116  NamedDecl* IDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
1118  if (!IDecl)
1119  return;
1120 
1121  if (const TypedefNameDecl *TDecl = dyn_cast_or_null<TypedefNameDecl>(IDecl)) {
1122  QualType T = TDecl->getUnderlyingType();
1123  if (T->isObjCObjectType())
1124  if (const ObjCObjectType *OPT = T->getAs<ObjCObjectType>()) {
1125  ProtocolRefs.append(OPT->qual_begin(), OPT->qual_end());
1126  // FIXME: Consider whether this should be an invalid loc since the loc
1127  // is not actually pointing to a protocol name reference but to the
1128  // typedef reference. Note that the base class name loc is also pointing
1129  // at the typedef.
1130  ProtocolLocs.append(OPT->getNumProtocols(), SuperLoc);
1131  }
1132  }
1133 }
1134 
1135 /// ActOnCompatibilityAlias - this action is called after complete parsing of
1136 /// a \@compatibility_alias declaration. It sets up the alias relationships.
1138  IdentifierInfo *AliasName,
1139  SourceLocation AliasLocation,
1140  IdentifierInfo *ClassName,
1141  SourceLocation ClassLocation) {
1142  // Look for previous declaration of alias name
1143  NamedDecl *ADecl =
1144  LookupSingleName(TUScope, AliasName, AliasLocation, LookupOrdinaryName,
1146  if (ADecl) {
1147  Diag(AliasLocation, diag::err_conflicting_aliasing_type) << AliasName;
1148  Diag(ADecl->getLocation(), diag::note_previous_declaration);
1149  return nullptr;
1150  }
1151  // Check for class declaration
1152  NamedDecl *CDeclU =
1153  LookupSingleName(TUScope, ClassName, ClassLocation, LookupOrdinaryName,
1155  if (const TypedefNameDecl *TDecl =
1156  dyn_cast_or_null<TypedefNameDecl>(CDeclU)) {
1157  QualType T = TDecl->getUnderlyingType();
1158  if (T->isObjCObjectType()) {
1159  if (NamedDecl *IDecl = T->castAs<ObjCObjectType>()->getInterface()) {
1160  ClassName = IDecl->getIdentifier();
1161  CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation,
1164  }
1165  }
1166  }
1167  ObjCInterfaceDecl *CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDeclU);
1168  if (!CDecl) {
1169  Diag(ClassLocation, diag::warn_undef_interface) << ClassName;
1170  if (CDeclU)
1171  Diag(CDeclU->getLocation(), diag::note_previous_declaration);
1172  return nullptr;
1173  }
1174 
1175  // Everything checked out, instantiate a new alias declaration AST.
1177  ObjCCompatibleAliasDecl::Create(Context, CurContext, AtLoc, AliasName, CDecl);
1178 
1181 
1182  return AliasDecl;
1183 }
1184 
1186  IdentifierInfo *PName,
1187  SourceLocation &Ploc, SourceLocation PrevLoc,
1188  const ObjCList<ObjCProtocolDecl> &PList) {
1189 
1190  bool res = false;
1192  E = PList.end(); I != E; ++I) {
1193  if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier(),
1194  Ploc)) {
1195  if (PDecl->getIdentifier() == PName) {
1196  Diag(Ploc, diag::err_protocol_has_circular_dependency);
1197  Diag(PrevLoc, diag::note_previous_definition);
1198  res = true;
1199  }
1200 
1201  if (!PDecl->hasDefinition())
1202  continue;
1203 
1205  PDecl->getLocation(), PDecl->getReferencedProtocols()))
1206  res = true;
1207  }
1208  }
1209  return res;
1210 }
1211 
1213  SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName,
1214  SourceLocation ProtocolLoc, Decl *const *ProtoRefs, unsigned NumProtoRefs,
1215  const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
1216  const ParsedAttributesView &AttrList) {
1217  bool err = false;
1218  // FIXME: Deal with AttrList.
1219  assert(ProtocolName && "Missing protocol identifier");
1220  ObjCProtocolDecl *PrevDecl = LookupProtocol(ProtocolName, ProtocolLoc,
1222  ObjCProtocolDecl *PDecl = nullptr;
1223  if (ObjCProtocolDecl *Def = PrevDecl? PrevDecl->getDefinition() : nullptr) {
1224  // If we already have a definition, complain.
1225  Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName;
1226  Diag(Def->getLocation(), diag::note_previous_definition);
1227 
1228  // Create a new protocol that is completely distinct from previous
1229  // declarations, and do not make this protocol available for name lookup.
1230  // That way, we'll end up completely ignoring the duplicate.
1231  // FIXME: Can we turn this into an error?
1232  PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
1233  ProtocolLoc, AtProtoInterfaceLoc,
1234  /*PrevDecl=*/nullptr);
1235 
1236  // If we are using modules, add the decl to the context in order to
1237  // serialize something meaningful.
1238  if (getLangOpts().Modules)
1239  PushOnScopeChains(PDecl, TUScope);
1240  PDecl->startDefinition();
1241  } else {
1242  if (PrevDecl) {
1243  // Check for circular dependencies among protocol declarations. This can
1244  // only happen if this protocol was forward-declared.
1246  PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context);
1248  ProtocolName, ProtocolLoc, PrevDecl->getLocation(), PList);
1249  }
1250 
1251  // Create the new declaration.
1252  PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
1253  ProtocolLoc, AtProtoInterfaceLoc,
1254  /*PrevDecl=*/PrevDecl);
1255 
1256  PushOnScopeChains(PDecl, TUScope);
1257  PDecl->startDefinition();
1258  }
1259 
1260  ProcessDeclAttributeList(TUScope, PDecl, AttrList);
1261  AddPragmaAttributes(TUScope, PDecl);
1262 
1263  // Merge attributes from previous declarations.
1264  if (PrevDecl)
1265  mergeDeclAttributes(PDecl, PrevDecl);
1266 
1267  if (!err && NumProtoRefs ) {
1268  /// Check then save referenced protocols.
1269  diagnoseUseOfProtocols(*this, PDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1270  NumProtoRefs, ProtoLocs);
1271  PDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1272  ProtoLocs, Context);
1273  }
1274 
1275  CheckObjCDeclScope(PDecl);
1277  return PDecl;
1278 }
1279 
1281  ObjCProtocolDecl *&UndefinedProtocol) {
1282  if (!PDecl->hasDefinition() ||
1283  !PDecl->getDefinition()->isUnconditionallyVisible()) {
1284  UndefinedProtocol = PDecl;
1285  return true;
1286  }
1287 
1288  for (auto *PI : PDecl->protocols())
1289  if (NestedProtocolHasNoDefinition(PI, UndefinedProtocol)) {
1290  UndefinedProtocol = PI;
1291  return true;
1292  }
1293  return false;
1294 }
1295 
1296 /// FindProtocolDeclaration - This routine looks up protocols and
1297 /// issues an error if they are not declared. It returns list of
1298 /// protocol declarations in its 'Protocols' argument.
1299 void
1300 Sema::FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer,
1301  ArrayRef<IdentifierLocPair> ProtocolId,
1302  SmallVectorImpl<Decl *> &Protocols) {
1303  for (const IdentifierLocPair &Pair : ProtocolId) {
1304  ObjCProtocolDecl *PDecl = LookupProtocol(Pair.first, Pair.second);
1305  if (!PDecl) {
1307  TypoCorrection Corrected = CorrectTypo(
1308  DeclarationNameInfo(Pair.first, Pair.second), LookupObjCProtocolName,
1309  TUScope, nullptr, CCC, CTK_ErrorRecovery);
1310  if ((PDecl = Corrected.getCorrectionDeclAs<ObjCProtocolDecl>()))
1311  diagnoseTypo(Corrected, PDiag(diag::err_undeclared_protocol_suggest)
1312  << Pair.first);
1313  }
1314 
1315  if (!PDecl) {
1316  Diag(Pair.second, diag::err_undeclared_protocol) << Pair.first;
1317  continue;
1318  }
1319  // If this is a forward protocol declaration, get its definition.
1320  if (!PDecl->isThisDeclarationADefinition() && PDecl->getDefinition())
1321  PDecl = PDecl->getDefinition();
1322 
1323  // For an objc container, delay protocol reference checking until after we
1324  // can set the objc decl as the availability context, otherwise check now.
1325  if (!ForObjCContainer) {
1326  (void)DiagnoseUseOfDecl(PDecl, Pair.second);
1327  }
1328 
1329  // If this is a forward declaration and we are supposed to warn in this
1330  // case, do it.
1331  // FIXME: Recover nicely in the hidden case.
1332  ObjCProtocolDecl *UndefinedProtocol;
1333 
1334  if (WarnOnDeclarations &&
1335  NestedProtocolHasNoDefinition(PDecl, UndefinedProtocol)) {
1336  Diag(Pair.second, diag::warn_undef_protocolref) << Pair.first;
1337  Diag(UndefinedProtocol->getLocation(), diag::note_protocol_decl_undefined)
1338  << UndefinedProtocol;
1339  }
1340  Protocols.push_back(PDecl);
1341  }
1342 }
1343 
1344 namespace {
1345 // Callback to only accept typo corrections that are either
1346 // Objective-C protocols or valid Objective-C type arguments.
1347 class ObjCTypeArgOrProtocolValidatorCCC final
1348  : public CorrectionCandidateCallback {
1349  ASTContext &Context;
1350  Sema::LookupNameKind LookupKind;
1351  public:
1352  ObjCTypeArgOrProtocolValidatorCCC(ASTContext &context,
1353  Sema::LookupNameKind lookupKind)
1354  : Context(context), LookupKind(lookupKind) { }
1355 
1356  bool ValidateCandidate(const TypoCorrection &candidate) override {
1357  // If we're allowed to find protocols and we have a protocol, accept it.
1358  if (LookupKind != Sema::LookupOrdinaryName) {
1359  if (candidate.getCorrectionDeclAs<ObjCProtocolDecl>())
1360  return true;
1361  }
1362 
1363  // If we're allowed to find type names and we have one, accept it.
1364  if (LookupKind != Sema::LookupObjCProtocolName) {
1365  // If we have a type declaration, we might accept this result.
1366  if (auto typeDecl = candidate.getCorrectionDeclAs<TypeDecl>()) {
1367  // If we found a tag declaration outside of C++, skip it. This
1368  // can happy because we look for any name when there is no
1369  // bias to protocol or type names.
1370  if (isa<RecordDecl>(typeDecl) && !Context.getLangOpts().CPlusPlus)
1371  return false;
1372 
1373  // Make sure the type is something we would accept as a type
1374  // argument.
1375  auto type = Context.getTypeDeclType(typeDecl);
1376  if (type->isObjCObjectPointerType() ||
1377  type->isBlockPointerType() ||
1378  type->isDependentType() ||
1379  type->isObjCObjectType())
1380  return true;
1381 
1382  return false;
1383  }
1384 
1385  // If we have an Objective-C class type, accept it; there will
1386  // be another fix to add the '*'.
1387  if (candidate.getCorrectionDeclAs<ObjCInterfaceDecl>())
1388  return true;
1389 
1390  return false;
1391  }
1392 
1393  return false;
1394  }
1395 
1396  std::unique_ptr<CorrectionCandidateCallback> clone() override {
1397  return std::make_unique<ObjCTypeArgOrProtocolValidatorCCC>(*this);
1398  }
1399 };
1400 } // end anonymous namespace
1401 
1403  SourceLocation ProtocolLoc,
1404  IdentifierInfo *TypeArgId,
1405  SourceLocation TypeArgLoc,
1406  bool SelectProtocolFirst) {
1407  Diag(TypeArgLoc, diag::err_objc_type_args_and_protocols)
1408  << SelectProtocolFirst << TypeArgId << ProtocolId
1409  << SourceRange(ProtocolLoc);
1410 }
1411 
1413  Scope *S,
1414  ParsedType baseType,
1415  SourceLocation lAngleLoc,
1416  ArrayRef<IdentifierInfo *> identifiers,
1417  ArrayRef<SourceLocation> identifierLocs,
1418  SourceLocation rAngleLoc,
1419  SourceLocation &typeArgsLAngleLoc,
1420  SmallVectorImpl<ParsedType> &typeArgs,
1421  SourceLocation &typeArgsRAngleLoc,
1422  SourceLocation &protocolLAngleLoc,
1423  SmallVectorImpl<Decl *> &protocols,
1424  SourceLocation &protocolRAngleLoc,
1425  bool warnOnIncompleteProtocols) {
1426  // Local function that updates the declaration specifiers with
1427  // protocol information.
1428  unsigned numProtocolsResolved = 0;
1429  auto resolvedAsProtocols = [&] {
1430  assert(numProtocolsResolved == identifiers.size() && "Unresolved protocols");
1431 
1432  // Determine whether the base type is a parameterized class, in
1433  // which case we want to warn about typos such as
1434  // "NSArray<NSObject>" (that should be NSArray<NSObject *>).
1435  ObjCInterfaceDecl *baseClass = nullptr;
1436  QualType base = GetTypeFromParser(baseType, nullptr);
1437  bool allAreTypeNames = false;
1438  SourceLocation firstClassNameLoc;
1439  if (!base.isNull()) {
1440  if (const auto *objcObjectType = base->getAs<ObjCObjectType>()) {
1441  baseClass = objcObjectType->getInterface();
1442  if (baseClass) {
1443  if (auto typeParams = baseClass->getTypeParamList()) {
1444  if (typeParams->size() == numProtocolsResolved) {
1445  // Note that we should be looking for type names, too.
1446  allAreTypeNames = true;
1447  }
1448  }
1449  }
1450  }
1451  }
1452 
1453  for (unsigned i = 0, n = protocols.size(); i != n; ++i) {
1454  ObjCProtocolDecl *&proto
1455  = reinterpret_cast<ObjCProtocolDecl *&>(protocols[i]);
1456  // For an objc container, delay protocol reference checking until after we
1457  // can set the objc decl as the availability context, otherwise check now.
1458  if (!warnOnIncompleteProtocols) {
1459  (void)DiagnoseUseOfDecl(proto, identifierLocs[i]);
1460  }
1461 
1462  // If this is a forward protocol declaration, get its definition.
1463  if (!proto->isThisDeclarationADefinition() && proto->getDefinition())
1464  proto = proto->getDefinition();
1465 
1466  // If this is a forward declaration and we are supposed to warn in this
1467  // case, do it.
1468  // FIXME: Recover nicely in the hidden case.
1469  ObjCProtocolDecl *forwardDecl = nullptr;
1470  if (warnOnIncompleteProtocols &&
1471  NestedProtocolHasNoDefinition(proto, forwardDecl)) {
1472  Diag(identifierLocs[i], diag::warn_undef_protocolref)
1473  << proto->getDeclName();
1474  Diag(forwardDecl->getLocation(), diag::note_protocol_decl_undefined)
1475  << forwardDecl;
1476  }
1477 
1478  // If everything this far has been a type name (and we care
1479  // about such things), check whether this name refers to a type
1480  // as well.
1481  if (allAreTypeNames) {
1482  if (auto *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
1483  LookupOrdinaryName)) {
1484  if (isa<ObjCInterfaceDecl>(decl)) {
1485  if (firstClassNameLoc.isInvalid())
1486  firstClassNameLoc = identifierLocs[i];
1487  } else if (!isa<TypeDecl>(decl)) {
1488  // Not a type.
1489  allAreTypeNames = false;
1490  }
1491  } else {
1492  allAreTypeNames = false;
1493  }
1494  }
1495  }
1496 
1497  // All of the protocols listed also have type names, and at least
1498  // one is an Objective-C class name. Check whether all of the
1499  // protocol conformances are declared by the base class itself, in
1500  // which case we warn.
1501  if (allAreTypeNames && firstClassNameLoc.isValid()) {
1503  Context.CollectInheritedProtocols(baseClass, knownProtocols);
1504  bool allProtocolsDeclared = true;
1505  for (auto proto : protocols) {
1506  if (knownProtocols.count(static_cast<ObjCProtocolDecl *>(proto)) == 0) {
1507  allProtocolsDeclared = false;
1508  break;
1509  }
1510  }
1511 
1512  if (allProtocolsDeclared) {
1513  Diag(firstClassNameLoc, diag::warn_objc_redundant_qualified_class_type)
1514  << baseClass->getDeclName() << SourceRange(lAngleLoc, rAngleLoc)
1515  << FixItHint::CreateInsertion(getLocForEndOfToken(firstClassNameLoc),
1516  " *");
1517  }
1518  }
1519 
1520  protocolLAngleLoc = lAngleLoc;
1521  protocolRAngleLoc = rAngleLoc;
1522  assert(protocols.size() == identifierLocs.size());
1523  };
1524 
1525  // Attempt to resolve all of the identifiers as protocols.
1526  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1527  ObjCProtocolDecl *proto = LookupProtocol(identifiers[i], identifierLocs[i]);
1528  protocols.push_back(proto);
1529  if (proto)
1530  ++numProtocolsResolved;
1531  }
1532 
1533  // If all of the names were protocols, these were protocol qualifiers.
1534  if (numProtocolsResolved == identifiers.size())
1535  return resolvedAsProtocols();
1536 
1537  // Attempt to resolve all of the identifiers as type names or
1538  // Objective-C class names. The latter is technically ill-formed,
1539  // but is probably something like \c NSArray<NSView *> missing the
1540  // \c*.
1541  typedef llvm::PointerUnion<TypeDecl *, ObjCInterfaceDecl *> TypeOrClassDecl;
1543  unsigned numTypeDeclsResolved = 0;
1544  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1545  NamedDecl *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
1547  if (!decl) {
1548  typeDecls.push_back(TypeOrClassDecl());
1549  continue;
1550  }
1551 
1552  if (auto typeDecl = dyn_cast<TypeDecl>(decl)) {
1553  typeDecls.push_back(typeDecl);
1554  ++numTypeDeclsResolved;
1555  continue;
1556  }
1557 
1558  if (auto objcClass = dyn_cast<ObjCInterfaceDecl>(decl)) {
1559  typeDecls.push_back(objcClass);
1560  ++numTypeDeclsResolved;
1561  continue;
1562  }
1563 
1564  typeDecls.push_back(TypeOrClassDecl());
1565  }
1566 
1567  AttributeFactory attrFactory;
1568 
1569  // Local function that forms a reference to the given type or
1570  // Objective-C class declaration.
1571  auto resolveTypeReference = [&](TypeOrClassDecl typeDecl, SourceLocation loc)
1572  -> TypeResult {
1573  // Form declaration specifiers. They simply refer to the type.
1574  DeclSpec DS(attrFactory);
1575  const char* prevSpec; // unused
1576  unsigned diagID; // unused
1577  QualType type;
1578  if (auto *actualTypeDecl = typeDecl.dyn_cast<TypeDecl *>())
1579  type = Context.getTypeDeclType(actualTypeDecl);
1580  else
1581  type = Context.getObjCInterfaceType(typeDecl.get<ObjCInterfaceDecl *>());
1582  TypeSourceInfo *parsedTSInfo = Context.getTrivialTypeSourceInfo(type, loc);
1583  ParsedType parsedType = CreateParsedType(type, parsedTSInfo);
1584  DS.SetTypeSpecType(DeclSpec::TST_typename, loc, prevSpec, diagID,
1585  parsedType, Context.getPrintingPolicy());
1586  // Use the identifier location for the type source range.
1587  DS.SetRangeStart(loc);
1588  DS.SetRangeEnd(loc);
1589 
1590  // Form the declarator.
1592 
1593  // If we have a typedef of an Objective-C class type that is missing a '*',
1594  // add the '*'.
1595  if (type->getAs<ObjCInterfaceType>()) {
1596  SourceLocation starLoc = getLocForEndOfToken(loc);
1597  D.AddTypeInfo(DeclaratorChunk::getPointer(/*TypeQuals=*/0, starLoc,
1598  SourceLocation(),
1599  SourceLocation(),
1600  SourceLocation(),
1601  SourceLocation(),
1602  SourceLocation()),
1603  starLoc);
1604 
1605  // Diagnose the missing '*'.
1606  Diag(loc, diag::err_objc_type_arg_missing_star)
1607  << type
1608  << FixItHint::CreateInsertion(starLoc, " *");
1609  }
1610 
1611  // Convert this to a type.
1612  return ActOnTypeName(S, D);
1613  };
1614 
1615  // Local function that updates the declaration specifiers with
1616  // type argument information.
1617  auto resolvedAsTypeDecls = [&] {
1618  // We did not resolve these as protocols.
1619  protocols.clear();
1620 
1621  assert(numTypeDeclsResolved == identifiers.size() && "Unresolved type decl");
1622  // Map type declarations to type arguments.
1623  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1624  // Map type reference to a type.
1625  TypeResult type = resolveTypeReference(typeDecls[i], identifierLocs[i]);
1626  if (!type.isUsable()) {
1627  typeArgs.clear();
1628  return;
1629  }
1630 
1631  typeArgs.push_back(type.get());
1632  }
1633 
1634  typeArgsLAngleLoc = lAngleLoc;
1635  typeArgsRAngleLoc = rAngleLoc;
1636  };
1637 
1638  // If all of the identifiers can be resolved as type names or
1639  // Objective-C class names, we have type arguments.
1640  if (numTypeDeclsResolved == identifiers.size())
1641  return resolvedAsTypeDecls();
1642 
1643  // Error recovery: some names weren't found, or we have a mix of
1644  // type and protocol names. Go resolve all of the unresolved names
1645  // and complain if we can't find a consistent answer.
1646  LookupNameKind lookupKind = LookupAnyName;
1647  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1648  // If we already have a protocol or type. Check whether it is the
1649  // right thing.
1650  if (protocols[i] || typeDecls[i]) {
1651  // If we haven't figured out whether we want types or protocols
1652  // yet, try to figure it out from this name.
1653  if (lookupKind == LookupAnyName) {
1654  // If this name refers to both a protocol and a type (e.g., \c
1655  // NSObject), don't conclude anything yet.
1656  if (protocols[i] && typeDecls[i])
1657  continue;
1658 
1659  // Otherwise, let this name decide whether we'll be correcting
1660  // toward types or protocols.
1661  lookupKind = protocols[i] ? LookupObjCProtocolName
1663  continue;
1664  }
1665 
1666  // If we want protocols and we have a protocol, there's nothing
1667  // more to do.
1668  if (lookupKind == LookupObjCProtocolName && protocols[i])
1669  continue;
1670 
1671  // If we want types and we have a type declaration, there's
1672  // nothing more to do.
1673  if (lookupKind == LookupOrdinaryName && typeDecls[i])
1674  continue;
1675 
1676  // We have a conflict: some names refer to protocols and others
1677  // refer to types.
1678  DiagnoseTypeArgsAndProtocols(identifiers[0], identifierLocs[0],
1679  identifiers[i], identifierLocs[i],
1680  protocols[i] != nullptr);
1681 
1682  protocols.clear();
1683  typeArgs.clear();
1684  return;
1685  }
1686 
1687  // Perform typo correction on the name.
1688  ObjCTypeArgOrProtocolValidatorCCC CCC(Context, lookupKind);
1689  TypoCorrection corrected =
1690  CorrectTypo(DeclarationNameInfo(identifiers[i], identifierLocs[i]),
1691  lookupKind, S, nullptr, CCC, CTK_ErrorRecovery);
1692  if (corrected) {
1693  // Did we find a protocol?
1694  if (auto proto = corrected.getCorrectionDeclAs<ObjCProtocolDecl>()) {
1695  diagnoseTypo(corrected,
1696  PDiag(diag::err_undeclared_protocol_suggest)
1697  << identifiers[i]);
1698  lookupKind = LookupObjCProtocolName;
1699  protocols[i] = proto;
1700  ++numProtocolsResolved;
1701  continue;
1702  }
1703 
1704  // Did we find a type?
1705  if (auto typeDecl = corrected.getCorrectionDeclAs<TypeDecl>()) {
1706  diagnoseTypo(corrected,
1707  PDiag(diag::err_unknown_typename_suggest)
1708  << identifiers[i]);
1709  lookupKind = LookupOrdinaryName;
1710  typeDecls[i] = typeDecl;
1711  ++numTypeDeclsResolved;
1712  continue;
1713  }
1714 
1715  // Did we find an Objective-C class?
1716  if (auto objcClass = corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1717  diagnoseTypo(corrected,
1718  PDiag(diag::err_unknown_type_or_class_name_suggest)
1719  << identifiers[i] << true);
1720  lookupKind = LookupOrdinaryName;
1721  typeDecls[i] = objcClass;
1722  ++numTypeDeclsResolved;
1723  continue;
1724  }
1725  }
1726 
1727  // We couldn't find anything.
1728  Diag(identifierLocs[i],
1729  (lookupKind == LookupAnyName ? diag::err_objc_type_arg_missing
1730  : lookupKind == LookupObjCProtocolName ? diag::err_undeclared_protocol
1731  : diag::err_unknown_typename))
1732  << identifiers[i];
1733  protocols.clear();
1734  typeArgs.clear();
1735  return;
1736  }
1737 
1738  // If all of the names were (corrected to) protocols, these were
1739  // protocol qualifiers.
1740  if (numProtocolsResolved == identifiers.size())
1741  return resolvedAsProtocols();
1742 
1743  // Otherwise, all of the names were (corrected to) types.
1744  assert(numTypeDeclsResolved == identifiers.size() && "Not all types?");
1745  return resolvedAsTypeDecls();
1746 }
1747 
1748 /// DiagnoseClassExtensionDupMethods - Check for duplicate declaration of
1749 /// a class method in its extension.
1750 ///
1752  ObjCInterfaceDecl *ID) {
1753  if (!ID)
1754  return; // Possibly due to previous error
1755 
1756  llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap;
1757  for (auto *MD : ID->methods())
1758  MethodMap[MD->getSelector()] = MD;
1759 
1760  if (MethodMap.empty())
1761  return;
1762  for (const auto *Method : CAT->methods()) {
1763  const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()];
1764  if (PrevMethod &&
1765  (PrevMethod->isInstanceMethod() == Method->isInstanceMethod()) &&
1766  !MatchTwoMethodDeclarations(Method, PrevMethod)) {
1767  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
1768  << Method->getDeclName();
1769  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
1770  }
1771  }
1772 }
1773 
1774 /// ActOnForwardProtocolDeclaration - Handle \@protocol foo;
1777  ArrayRef<IdentifierLocPair> IdentList,
1778  const ParsedAttributesView &attrList) {
1779  SmallVector<Decl *, 8> DeclsInGroup;
1780  for (const IdentifierLocPair &IdentPair : IdentList) {
1781  IdentifierInfo *Ident = IdentPair.first;
1782  ObjCProtocolDecl *PrevDecl = LookupProtocol(Ident, IdentPair.second,
1784  ObjCProtocolDecl *PDecl
1786  IdentPair.second, AtProtocolLoc,
1787  PrevDecl);
1788 
1789  PushOnScopeChains(PDecl, TUScope);
1790  CheckObjCDeclScope(PDecl);
1791 
1792  ProcessDeclAttributeList(TUScope, PDecl, attrList);
1793  AddPragmaAttributes(TUScope, PDecl);
1794 
1795  if (PrevDecl)
1796  mergeDeclAttributes(PDecl, PrevDecl);
1797 
1798  DeclsInGroup.push_back(PDecl);
1799  }
1800 
1801  return BuildDeclaratorGroup(DeclsInGroup);
1802 }
1803 
1805  SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
1806  SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
1807  IdentifierInfo *CategoryName, SourceLocation CategoryLoc,
1808  Decl *const *ProtoRefs, unsigned NumProtoRefs,
1809  const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
1810  const ParsedAttributesView &AttrList) {
1811  ObjCCategoryDecl *CDecl;
1812  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
1813 
1814  /// Check that class of this category is already completely declared.
1815 
1816  if (!IDecl
1817  || RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
1818  diag::err_category_forward_interface,
1819  CategoryName == nullptr)) {
1820  // Create an invalid ObjCCategoryDecl to serve as context for
1821  // the enclosing method declarations. We mark the decl invalid
1822  // to make it clear that this isn't a valid AST.
1823  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
1824  ClassLoc, CategoryLoc, CategoryName,
1825  IDecl, typeParamList);
1826  CDecl->setInvalidDecl();
1827  CurContext->addDecl(CDecl);
1828 
1829  if (!IDecl)
1830  Diag(ClassLoc, diag::err_undef_interface) << ClassName;
1832  return CDecl;
1833  }
1834 
1835  if (!CategoryName && IDecl->getImplementation()) {
1836  Diag(ClassLoc, diag::err_class_extension_after_impl) << ClassName;
1837  Diag(IDecl->getImplementation()->getLocation(),
1838  diag::note_implementation_declared);
1839  }
1840 
1841  if (CategoryName) {
1842  /// Check for duplicate interface declaration for this category
1844  = IDecl->FindCategoryDeclaration(CategoryName)) {
1845  // Class extensions can be declared multiple times, categories cannot.
1846  Diag(CategoryLoc, diag::warn_dup_category_def)
1847  << ClassName << CategoryName;
1848  Diag(Previous->getLocation(), diag::note_previous_definition);
1849  }
1850  }
1851 
1852  // If we have a type parameter list, check it.
1853  if (typeParamList) {
1854  if (auto prevTypeParamList = IDecl->getTypeParamList()) {
1855  if (checkTypeParamListConsistency(*this, prevTypeParamList, typeParamList,
1856  CategoryName
1858  : TypeParamListContext::Extension))
1859  typeParamList = nullptr;
1860  } else {
1861  Diag(typeParamList->getLAngleLoc(),
1862  diag::err_objc_parameterized_category_nonclass)
1863  << (CategoryName != nullptr)
1864  << ClassName
1865  << typeParamList->getSourceRange();
1866 
1867  typeParamList = nullptr;
1868  }
1869  }
1870 
1871  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
1872  ClassLoc, CategoryLoc, CategoryName, IDecl,
1873  typeParamList);
1874  // FIXME: PushOnScopeChains?
1875  CurContext->addDecl(CDecl);
1876 
1877  // Process the attributes before looking at protocols to ensure that the
1878  // availability attribute is attached to the category to provide availability
1879  // checking for protocol uses.
1880  ProcessDeclAttributeList(TUScope, CDecl, AttrList);
1881  AddPragmaAttributes(TUScope, CDecl);
1882 
1883  if (NumProtoRefs) {
1884  diagnoseUseOfProtocols(*this, CDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1885  NumProtoRefs, ProtoLocs);
1886  CDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1887  ProtoLocs, Context);
1888  // Protocols in the class extension belong to the class.
1889  if (CDecl->IsClassExtension())
1890  IDecl->mergeClassExtensionProtocolList((ObjCProtocolDecl*const*)ProtoRefs,
1891  NumProtoRefs, Context);
1892  }
1893 
1894  CheckObjCDeclScope(CDecl);
1896  return CDecl;
1897 }
1898 
1899 /// ActOnStartCategoryImplementation - Perform semantic checks on the
1900 /// category implementation declaration and build an ObjCCategoryImplDecl
1901 /// object.
1903  SourceLocation AtCatImplLoc, IdentifierInfo *ClassName,
1904  SourceLocation ClassLoc, IdentifierInfo *CatName, SourceLocation CatLoc,
1905  const ParsedAttributesView &Attrs) {
1906  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
1907  ObjCCategoryDecl *CatIDecl = nullptr;
1908  if (IDecl && IDecl->hasDefinition()) {
1909  CatIDecl = IDecl->FindCategoryDeclaration(CatName);
1910  if (!CatIDecl) {
1911  // Category @implementation with no corresponding @interface.
1912  // Create and install one.
1913  CatIDecl = ObjCCategoryDecl::Create(Context, CurContext, AtCatImplLoc,
1914  ClassLoc, CatLoc,
1915  CatName, IDecl,
1916  /*typeParamList=*/nullptr);
1917  CatIDecl->setImplicit();
1918  }
1919  }
1920 
1921  ObjCCategoryImplDecl *CDecl =
1923  ClassLoc, AtCatImplLoc, CatLoc);
1924  /// Check that class of this category is already completely declared.
1925  if (!IDecl) {
1926  Diag(ClassLoc, diag::err_undef_interface) << ClassName;
1927  CDecl->setInvalidDecl();
1928  } else if (RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
1929  diag::err_undef_interface)) {
1930  CDecl->setInvalidDecl();
1931  }
1932 
1933  ProcessDeclAttributeList(TUScope, CDecl, Attrs);
1934  AddPragmaAttributes(TUScope, CDecl);
1935 
1936  // FIXME: PushOnScopeChains?
1937  CurContext->addDecl(CDecl);
1938 
1939  // If the interface has the objc_runtime_visible attribute, we
1940  // cannot implement a category for it.
1941  if (IDecl && IDecl->hasAttr<ObjCRuntimeVisibleAttr>()) {
1942  Diag(ClassLoc, diag::err_objc_runtime_visible_category)
1943  << IDecl->getDeclName();
1944  }
1945 
1946  /// Check that CatName, category name, is not used in another implementation.
1947  if (CatIDecl) {
1948  if (CatIDecl->getImplementation()) {
1949  Diag(ClassLoc, diag::err_dup_implementation_category) << ClassName
1950  << CatName;
1951  Diag(CatIDecl->getImplementation()->getLocation(),
1952  diag::note_previous_definition);
1953  CDecl->setInvalidDecl();
1954  } else {
1955  CatIDecl->setImplementation(CDecl);
1956  // Warn on implementating category of deprecated class under
1957  // -Wdeprecated-implementations flag.
1958  DiagnoseObjCImplementedDeprecations(*this, CatIDecl,
1959  CDecl->getLocation());
1960  }
1961  }
1962 
1963  CheckObjCDeclScope(CDecl);
1965  return CDecl;
1966 }
1967 
1969  SourceLocation AtClassImplLoc, IdentifierInfo *ClassName,
1970  SourceLocation ClassLoc, IdentifierInfo *SuperClassname,
1971  SourceLocation SuperClassLoc, const ParsedAttributesView &Attrs) {
1972  ObjCInterfaceDecl *IDecl = nullptr;
1973  // Check for another declaration kind with the same name.
1974  NamedDecl *PrevDecl
1975  = LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
1977  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
1978  Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
1979  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1980  } else if ((IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl))) {
1981  // FIXME: This will produce an error if the definition of the interface has
1982  // been imported from a module but is not visible.
1984  diag::warn_undef_interface);
1985  } else {
1986  // We did not find anything with the name ClassName; try to correct for
1987  // typos in the class name.
1988  ObjCInterfaceValidatorCCC CCC{};
1989  TypoCorrection Corrected =
1990  CorrectTypo(DeclarationNameInfo(ClassName, ClassLoc),
1991  LookupOrdinaryName, TUScope, nullptr, CCC, CTK_NonError);
1992  if (Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1993  // Suggest the (potentially) correct interface name. Don't provide a
1994  // code-modification hint or use the typo name for recovery, because
1995  // this is just a warning. The program may actually be correct.
1996  diagnoseTypo(Corrected,
1997  PDiag(diag::warn_undef_interface_suggest) << ClassName,
1998  /*ErrorRecovery*/false);
1999  } else {
2000  Diag(ClassLoc, diag::warn_undef_interface) << ClassName;
2001  }
2002  }
2003 
2004  // Check that super class name is valid class name
2005  ObjCInterfaceDecl *SDecl = nullptr;
2006  if (SuperClassname) {
2007  // Check if a different kind of symbol declared in this scope.
2008  PrevDecl = LookupSingleName(TUScope, SuperClassname, SuperClassLoc,
2010  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
2011  Diag(SuperClassLoc, diag::err_redefinition_different_kind)
2012  << SuperClassname;
2013  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
2014  } else {
2015  SDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
2016  if (SDecl && !SDecl->hasDefinition())
2017  SDecl = nullptr;
2018  if (!SDecl)
2019  Diag(SuperClassLoc, diag::err_undef_superclass)
2020  << SuperClassname << ClassName;
2021  else if (IDecl && !declaresSameEntity(IDecl->getSuperClass(), SDecl)) {
2022  // This implementation and its interface do not have the same
2023  // super class.
2024  Diag(SuperClassLoc, diag::err_conflicting_super_class)
2025  << SDecl->getDeclName();
2026  Diag(SDecl->getLocation(), diag::note_previous_definition);
2027  }
2028  }
2029  }
2030 
2031  if (!IDecl) {
2032  // Legacy case of @implementation with no corresponding @interface.
2033  // Build, chain & install the interface decl into the identifier.
2034 
2035  // FIXME: Do we support attributes on the @implementation? If so we should
2036  // copy them over.
2037  IDecl = ObjCInterfaceDecl::Create(Context, CurContext, AtClassImplLoc,
2038  ClassName, /*typeParamList=*/nullptr,
2039  /*PrevDecl=*/nullptr, ClassLoc,
2040  true);
2041  AddPragmaAttributes(TUScope, IDecl);
2042  IDecl->startDefinition();
2043  if (SDecl) {
2046  SuperClassLoc));
2047  IDecl->setEndOfDefinitionLoc(SuperClassLoc);
2048  } else {
2049  IDecl->setEndOfDefinitionLoc(ClassLoc);
2050  }
2051 
2052  PushOnScopeChains(IDecl, TUScope);
2053  } else {
2054  // Mark the interface as being completed, even if it was just as
2055  // @class ....;
2056  // declaration; the user cannot reopen it.
2057  if (!IDecl->hasDefinition())
2058  IDecl->startDefinition();
2059  }
2060 
2061  ObjCImplementationDecl* IMPDecl =
2063  ClassLoc, AtClassImplLoc, SuperClassLoc);
2064 
2065  ProcessDeclAttributeList(TUScope, IMPDecl, Attrs);
2066  AddPragmaAttributes(TUScope, IMPDecl);
2067 
2068  if (CheckObjCDeclScope(IMPDecl)) {
2070  return IMPDecl;
2071  }
2072 
2073  // Check that there is no duplicate implementation of this class.
2074  if (IDecl->getImplementation()) {
2075  // FIXME: Don't leak everything!
2076  Diag(ClassLoc, diag::err_dup_implementation_class) << ClassName;
2077  Diag(IDecl->getImplementation()->getLocation(),
2078  diag::note_previous_definition);
2079  IMPDecl->setInvalidDecl();
2080  } else { // add it to the list.
2081  IDecl->setImplementation(IMPDecl);
2082  PushOnScopeChains(IMPDecl, TUScope);
2083  // Warn on implementating deprecated class under
2084  // -Wdeprecated-implementations flag.
2085  DiagnoseObjCImplementedDeprecations(*this, IDecl, IMPDecl->getLocation());
2086  }
2087 
2088  // If the superclass has the objc_runtime_visible attribute, we
2089  // cannot implement a subclass of it.
2090  if (IDecl->getSuperClass() &&
2091  IDecl->getSuperClass()->hasAttr<ObjCRuntimeVisibleAttr>()) {
2092  Diag(ClassLoc, diag::err_objc_runtime_visible_subclass)
2093  << IDecl->getDeclName()
2094  << IDecl->getSuperClass()->getDeclName();
2095  }
2096 
2098  return IMPDecl;
2099 }
2100 
2103  SmallVector<Decl *, 64> DeclsInGroup;
2104  DeclsInGroup.reserve(Decls.size() + 1);
2105 
2106  for (unsigned i = 0, e = Decls.size(); i != e; ++i) {
2107  Decl *Dcl = Decls[i];
2108  if (!Dcl)
2109  continue;
2110  if (Dcl->getDeclContext()->isFileContext())
2112  DeclsInGroup.push_back(Dcl);
2113  }
2114 
2115  DeclsInGroup.push_back(ObjCImpDecl);
2116 
2117  return BuildDeclaratorGroup(DeclsInGroup);
2118 }
2119 
2121  ObjCIvarDecl **ivars, unsigned numIvars,
2122  SourceLocation RBrace) {
2123  assert(ImpDecl && "missing implementation decl");
2124  ObjCInterfaceDecl* IDecl = ImpDecl->getClassInterface();
2125  if (!IDecl)
2126  return;
2127  /// Check case of non-existing \@interface decl.
2128  /// (legacy objective-c \@implementation decl without an \@interface decl).
2129  /// Add implementations's ivar to the synthesize class's ivar list.
2130  if (IDecl->isImplicitInterfaceDecl()) {
2131  IDecl->setEndOfDefinitionLoc(RBrace);
2132  // Add ivar's to class's DeclContext.
2133  for (unsigned i = 0, e = numIvars; i != e; ++i) {
2134  ivars[i]->setLexicalDeclContext(ImpDecl);
2135  // In a 'fragile' runtime the ivar was added to the implicit
2136  // ObjCInterfaceDecl while in a 'non-fragile' runtime the ivar is
2137  // only in the ObjCImplementationDecl. In the non-fragile case the ivar
2138  // therefore also needs to be propagated to the ObjCInterfaceDecl.
2140  IDecl->makeDeclVisibleInContext(ivars[i]);
2141  ImpDecl->addDecl(ivars[i]);
2142  }
2143 
2144  return;
2145  }
2146  // If implementation has empty ivar list, just return.
2147  if (numIvars == 0)
2148  return;
2149 
2150  assert(ivars && "missing @implementation ivars");
2152  if (ImpDecl->getSuperClass())
2153  Diag(ImpDecl->getLocation(), diag::warn_on_superclass_use);
2154  for (unsigned i = 0; i < numIvars; i++) {
2155  ObjCIvarDecl* ImplIvar = ivars[i];
2156  if (const ObjCIvarDecl *ClsIvar =
2157  IDecl->getIvarDecl(ImplIvar->getIdentifier())) {
2158  Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
2159  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2160  continue;
2161  }
2162  // Check class extensions (unnamed categories) for duplicate ivars.
2163  for (const auto *CDecl : IDecl->visible_extensions()) {
2164  if (const ObjCIvarDecl *ClsExtIvar =
2165  CDecl->getIvarDecl(ImplIvar->getIdentifier())) {
2166  Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
2167  Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
2168  continue;
2169  }
2170  }
2171  // Instance ivar to Implementation's DeclContext.
2172  ImplIvar->setLexicalDeclContext(ImpDecl);
2173  IDecl->makeDeclVisibleInContext(ImplIvar);
2174  ImpDecl->addDecl(ImplIvar);
2175  }
2176  return;
2177  }
2178  // Check interface's Ivar list against those in the implementation.
2179  // names and types must match.
2180  //
2181  unsigned j = 0;
2183  IVI = IDecl->ivar_begin(), IVE = IDecl->ivar_end();
2184  for (; numIvars > 0 && IVI != IVE; ++IVI) {
2185  ObjCIvarDecl* ImplIvar = ivars[j++];
2186  ObjCIvarDecl* ClsIvar = *IVI;
2187  assert (ImplIvar && "missing implementation ivar");
2188  assert (ClsIvar && "missing class ivar");
2189 
2190  // First, make sure the types match.
2191  if (!Context.hasSameType(ImplIvar->getType(), ClsIvar->getType())) {
2192  Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_type)
2193  << ImplIvar->getIdentifier()
2194  << ImplIvar->getType() << ClsIvar->getType();
2195  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2196  } else if (ImplIvar->isBitField() && ClsIvar->isBitField() &&
2197  ImplIvar->getBitWidthValue(Context) !=
2198  ClsIvar->getBitWidthValue(Context)) {
2199  Diag(ImplIvar->getBitWidth()->getBeginLoc(),
2200  diag::err_conflicting_ivar_bitwidth)
2201  << ImplIvar->getIdentifier();
2202  Diag(ClsIvar->getBitWidth()->getBeginLoc(),
2203  diag::note_previous_definition);
2204  }
2205  // Make sure the names are identical.
2206  if (ImplIvar->getIdentifier() != ClsIvar->getIdentifier()) {
2207  Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_name)
2208  << ImplIvar->getIdentifier() << ClsIvar->getIdentifier();
2209  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2210  }
2211  --numIvars;
2212  }
2213 
2214  if (numIvars > 0)
2215  Diag(ivars[j]->getLocation(), diag::err_inconsistent_ivar_count);
2216  else if (IVI != IVE)
2217  Diag(IVI->getLocation(), diag::err_inconsistent_ivar_count);
2218 }
2219 
2220 static void WarnUndefinedMethod(Sema &S, ObjCImplDecl *Impl,
2221  ObjCMethodDecl *method, bool &IncompleteImpl,
2222  unsigned DiagID,
2223  NamedDecl *NeededFor = nullptr) {
2224  // No point warning no definition of method which is 'unavailable'.
2225  if (method->getAvailability() == AR_Unavailable)
2226  return;
2227 
2228  // FIXME: For now ignore 'IncompleteImpl'.
2229  // Previously we grouped all unimplemented methods under a single
2230  // warning, but some users strongly voiced that they would prefer
2231  // separate warnings. We will give that approach a try, as that
2232  // matches what we do with protocols.
2233  {
2234  const Sema::SemaDiagnosticBuilder &B = S.Diag(Impl->getLocation(), DiagID);
2235  B << method;
2236  if (NeededFor)
2237  B << NeededFor;
2238 
2239  // Add an empty definition at the end of the @implementation.
2240  std::string FixItStr;
2241  llvm::raw_string_ostream Out(FixItStr);
2242  method->print(Out, Impl->getASTContext().getPrintingPolicy());
2243  Out << " {\n}\n\n";
2244 
2245  SourceLocation Loc = Impl->getAtEndRange().getBegin();
2246  B << FixItHint::CreateInsertion(Loc, FixItStr);
2247  }
2248 
2249  // Issue a note to the original declaration.
2250  SourceLocation MethodLoc = method->getBeginLoc();
2251  if (MethodLoc.isValid())
2252  S.Diag(MethodLoc, diag::note_method_declared_at) << method;
2253 }
2254 
2255 /// Determines if type B can be substituted for type A. Returns true if we can
2256 /// guarantee that anything that the user will do to an object of type A can
2257 /// also be done to an object of type B. This is trivially true if the two
2258 /// types are the same, or if B is a subclass of A. It becomes more complex
2259 /// in cases where protocols are involved.
2260 ///
2261 /// Object types in Objective-C describe the minimum requirements for an
2262 /// object, rather than providing a complete description of a type. For
2263 /// example, if A is a subclass of B, then B* may refer to an instance of A.
2264 /// The principle of substitutability means that we may use an instance of A
2265 /// anywhere that we may use an instance of B - it will implement all of the
2266 /// ivars of B and all of the methods of B.
2267 ///
2268 /// This substitutability is important when type checking methods, because
2269 /// the implementation may have stricter type definitions than the interface.
2270 /// The interface specifies minimum requirements, but the implementation may
2271 /// have more accurate ones. For example, a method may privately accept
2272 /// instances of B, but only publish that it accepts instances of A. Any
2273 /// object passed to it will be type checked against B, and so will implicitly
2274 /// by a valid A*. Similarly, a method may return a subclass of the class that
2275 /// it is declared as returning.
2276 ///
2277 /// This is most important when considering subclassing. A method in a
2278 /// subclass must accept any object as an argument that its superclass's
2279 /// implementation accepts. It may, however, accept a more general type
2280 /// without breaking substitutability (i.e. you can still use the subclass
2281 /// anywhere that you can use the superclass, but not vice versa). The
2282 /// converse requirement applies to return types: the return type for a
2283 /// subclass method must be a valid object of the kind that the superclass
2284 /// advertises, but it may be specified more accurately. This avoids the need
2285 /// for explicit down-casting by callers.
2286 ///
2287 /// Note: This is a stricter requirement than for assignment.
2289  const ObjCObjectPointerType *A,
2290  const ObjCObjectPointerType *B,
2291  bool rejectId) {
2292  // Reject a protocol-unqualified id.
2293  if (rejectId && B->isObjCIdType()) return false;
2294 
2295  // If B is a qualified id, then A must also be a qualified id and it must
2296  // implement all of the protocols in B. It may not be a qualified class.
2297  // For example, MyClass<A> can be assigned to id<A>, but MyClass<A> is a
2298  // stricter definition so it is not substitutable for id<A>.
2299  if (B->isObjCQualifiedIdType()) {
2300  return A->isObjCQualifiedIdType() &&
2301  Context.ObjCQualifiedIdTypesAreCompatible(A, B, false);
2302  }
2303 
2304  /*
2305  // id is a special type that bypasses type checking completely. We want a
2306  // warning when it is used in one place but not another.
2307  if (C.isObjCIdType(A) || C.isObjCIdType(B)) return false;
2308 
2309 
2310  // If B is a qualified id, then A must also be a qualified id (which it isn't
2311  // if we've got this far)
2312  if (B->isObjCQualifiedIdType()) return false;
2313  */
2314 
2315  // Now we know that A and B are (potentially-qualified) class types. The
2316  // normal rules for assignment apply.
2317  return Context.canAssignObjCInterfaces(A, B);
2318 }
2319 
2321  return (TSI ? TSI->getTypeLoc().getSourceRange() : SourceRange());
2322 }
2323 
2324 /// Determine whether two set of Objective-C declaration qualifiers conflict.
2327  return (x & ~Decl::OBJC_TQ_CSNullability) !=
2328  (y & ~Decl::OBJC_TQ_CSNullability);
2329 }
2330 
2332  ObjCMethodDecl *MethodImpl,
2333  ObjCMethodDecl *MethodDecl,
2334  bool IsProtocolMethodDecl,
2335  bool IsOverridingMode,
2336  bool Warn) {
2337  if (IsProtocolMethodDecl &&
2339  MethodImpl->getObjCDeclQualifier())) {
2340  if (Warn) {
2341  S.Diag(MethodImpl->getLocation(),
2342  (IsOverridingMode
2343  ? diag::warn_conflicting_overriding_ret_type_modifiers
2344  : diag::warn_conflicting_ret_type_modifiers))
2345  << MethodImpl->getDeclName()
2346  << MethodImpl->getReturnTypeSourceRange();
2347  S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration)
2348  << MethodDecl->getReturnTypeSourceRange();
2349  }
2350  else
2351  return false;
2352  }
2353  if (Warn && IsOverridingMode &&
2354  !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
2356  MethodDecl->getReturnType(),
2357  false)) {
2358  auto nullabilityMethodImpl =
2359  *MethodImpl->getReturnType()->getNullability(S.Context);
2360  auto nullabilityMethodDecl =
2361  *MethodDecl->getReturnType()->getNullability(S.Context);
2362  S.Diag(MethodImpl->getLocation(),
2363  diag::warn_conflicting_nullability_attr_overriding_ret_types)
2365  nullabilityMethodImpl,
2367  != 0))
2369  nullabilityMethodDecl,
2371  != 0));
2372  S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
2373  }
2374 
2375  if (S.Context.hasSameUnqualifiedType(MethodImpl->getReturnType(),
2376  MethodDecl->getReturnType()))
2377  return true;
2378  if (!Warn)
2379  return false;
2380 
2381  unsigned DiagID =
2382  IsOverridingMode ? diag::warn_conflicting_overriding_ret_types
2383  : diag::warn_conflicting_ret_types;
2384 
2385  // Mismatches between ObjC pointers go into a different warning
2386  // category, and sometimes they're even completely explicitly allowed.
2387  if (const ObjCObjectPointerType *ImplPtrTy =
2388  MethodImpl->getReturnType()->getAs<ObjCObjectPointerType>()) {
2389  if (const ObjCObjectPointerType *IfacePtrTy =
2390  MethodDecl->getReturnType()->getAs<ObjCObjectPointerType>()) {
2391  // Allow non-matching return types as long as they don't violate
2392  // the principle of substitutability. Specifically, we permit
2393  // return types that are subclasses of the declared return type,
2394  // or that are more-qualified versions of the declared type.
2395  if (isObjCTypeSubstitutable(S.Context, IfacePtrTy, ImplPtrTy, false))
2396  return false;
2397 
2398  DiagID =
2399  IsOverridingMode ? diag::warn_non_covariant_overriding_ret_types
2400  : diag::warn_non_covariant_ret_types;
2401  }
2402  }
2403 
2404  S.Diag(MethodImpl->getLocation(), DiagID)
2405  << MethodImpl->getDeclName() << MethodDecl->getReturnType()
2406  << MethodImpl->getReturnType()
2407  << MethodImpl->getReturnTypeSourceRange();
2408  S.Diag(MethodDecl->getLocation(), IsOverridingMode
2409  ? diag::note_previous_declaration
2410  : diag::note_previous_definition)
2411  << MethodDecl->getReturnTypeSourceRange();
2412  return false;
2413 }
2414 
2416  ObjCMethodDecl *MethodImpl,
2417  ObjCMethodDecl *MethodDecl,
2418  ParmVarDecl *ImplVar,
2419  ParmVarDecl *IfaceVar,
2420  bool IsProtocolMethodDecl,
2421  bool IsOverridingMode,
2422  bool Warn) {
2423  if (IsProtocolMethodDecl &&
2425  IfaceVar->getObjCDeclQualifier())) {
2426  if (Warn) {
2427  if (IsOverridingMode)
2428  S.Diag(ImplVar->getLocation(),
2429  diag::warn_conflicting_overriding_param_modifiers)
2430  << getTypeRange(ImplVar->getTypeSourceInfo())
2431  << MethodImpl->getDeclName();
2432  else S.Diag(ImplVar->getLocation(),
2433  diag::warn_conflicting_param_modifiers)
2434  << getTypeRange(ImplVar->getTypeSourceInfo())
2435  << MethodImpl->getDeclName();
2436  S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration)
2437  << getTypeRange(IfaceVar->getTypeSourceInfo());
2438  }
2439  else
2440  return false;
2441  }
2442 
2443  QualType ImplTy = ImplVar->getType();
2444  QualType IfaceTy = IfaceVar->getType();
2445  if (Warn && IsOverridingMode &&
2446  !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
2447  !S.Context.hasSameNullabilityTypeQualifier(ImplTy, IfaceTy, true)) {
2448  S.Diag(ImplVar->getLocation(),
2449  diag::warn_conflicting_nullability_attr_overriding_param_types)
2451  *ImplTy->getNullability(S.Context),
2453  != 0))
2455  *IfaceTy->getNullability(S.Context),
2457  != 0));
2458  S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration);
2459  }
2460  if (S.Context.hasSameUnqualifiedType(ImplTy, IfaceTy))
2461  return true;
2462 
2463  if (!Warn)
2464  return false;
2465  unsigned DiagID =
2466  IsOverridingMode ? diag::warn_conflicting_overriding_param_types
2467  : diag::warn_conflicting_param_types;
2468 
2469  // Mismatches between ObjC pointers go into a different warning
2470  // category, and sometimes they're even completely explicitly allowed..
2471  if (const ObjCObjectPointerType *ImplPtrTy =
2472  ImplTy->getAs<ObjCObjectPointerType>()) {
2473  if (const ObjCObjectPointerType *IfacePtrTy =
2474  IfaceTy->getAs<ObjCObjectPointerType>()) {
2475  // Allow non-matching argument types as long as they don't
2476  // violate the principle of substitutability. Specifically, the
2477  // implementation must accept any objects that the superclass
2478  // accepts, however it may also accept others.
2479  if (isObjCTypeSubstitutable(S.Context, ImplPtrTy, IfacePtrTy, true))
2480  return false;
2481 
2482  DiagID =
2483  IsOverridingMode ? diag::warn_non_contravariant_overriding_param_types
2484  : diag::warn_non_contravariant_param_types;
2485  }
2486  }
2487 
2488  S.Diag(ImplVar->getLocation(), DiagID)
2489  << getTypeRange(ImplVar->getTypeSourceInfo())
2490  << MethodImpl->getDeclName() << IfaceTy << ImplTy;
2491  S.Diag(IfaceVar->getLocation(),
2492  (IsOverridingMode ? diag::note_previous_declaration
2493  : diag::note_previous_definition))
2494  << getTypeRange(IfaceVar->getTypeSourceInfo());
2495  return false;
2496 }
2497 
2498 /// In ARC, check whether the conventional meanings of the two methods
2499 /// match. If they don't, it's a hard error.
2501  ObjCMethodDecl *decl) {
2502  ObjCMethodFamily implFamily = impl->getMethodFamily();
2503  ObjCMethodFamily declFamily = decl->getMethodFamily();
2504  if (implFamily == declFamily) return false;
2505 
2506  // Since conventions are sorted by selector, the only possibility is
2507  // that the types differ enough to cause one selector or the other
2508  // to fall out of the family.
2509  assert(implFamily == OMF_None || declFamily == OMF_None);
2510 
2511  // No further diagnostics required on invalid declarations.
2512  if (impl->isInvalidDecl() || decl->isInvalidDecl()) return true;
2513 
2514  const ObjCMethodDecl *unmatched = impl;
2515  ObjCMethodFamily family = declFamily;
2516  unsigned errorID = diag::err_arc_lost_method_convention;
2517  unsigned noteID = diag::note_arc_lost_method_convention;
2518  if (declFamily == OMF_None) {
2519  unmatched = decl;
2520  family = implFamily;
2521  errorID = diag::err_arc_gained_method_convention;
2522  noteID = diag::note_arc_gained_method_convention;
2523  }
2524 
2525  // Indexes into a %select clause in the diagnostic.
2526  enum FamilySelector {
2527  F_alloc, F_copy, F_mutableCopy = F_copy, F_init, F_new
2528  };
2529  FamilySelector familySelector = FamilySelector();
2530 
2531  switch (family) {
2532  case OMF_None: llvm_unreachable("logic error, no method convention");
2533  case OMF_retain:
2534  case OMF_release:
2535  case OMF_autorelease:
2536  case OMF_dealloc:
2537  case OMF_finalize:
2538  case OMF_retainCount:
2539  case OMF_self:
2540  case OMF_initialize:
2541  case OMF_performSelector:
2542  // Mismatches for these methods don't change ownership
2543  // conventions, so we don't care.
2544  return false;
2545 
2546  case OMF_init: familySelector = F_init; break;
2547  case OMF_alloc: familySelector = F_alloc; break;
2548  case OMF_copy: familySelector = F_copy; break;
2549  case OMF_mutableCopy: familySelector = F_mutableCopy; break;
2550  case OMF_new: familySelector = F_new; break;
2551  }
2552 
2553  enum ReasonSelector { R_NonObjectReturn, R_UnrelatedReturn };
2554  ReasonSelector reasonSelector;
2555 
2556  // The only reason these methods don't fall within their families is
2557  // due to unusual result types.
2558  if (unmatched->getReturnType()->isObjCObjectPointerType()) {
2559  reasonSelector = R_UnrelatedReturn;
2560  } else {
2561  reasonSelector = R_NonObjectReturn;
2562  }
2563 
2564  S.Diag(impl->getLocation(), errorID) << int(familySelector) << int(reasonSelector);
2565  S.Diag(decl->getLocation(), noteID) << int(familySelector) << int(reasonSelector);
2566 
2567  return true;
2568 }
2569 
2571  ObjCMethodDecl *MethodDecl,
2572  bool IsProtocolMethodDecl) {
2573  if (getLangOpts().ObjCAutoRefCount &&
2574  checkMethodFamilyMismatch(*this, ImpMethodDecl, MethodDecl))
2575  return;
2576 
2577  CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
2578  IsProtocolMethodDecl, false,
2579  true);
2580 
2581  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
2582  IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
2583  EF = MethodDecl->param_end();
2584  IM != EM && IF != EF; ++IM, ++IF) {
2585  CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, *IM, *IF,
2586  IsProtocolMethodDecl, false, true);
2587  }
2588 
2589  if (ImpMethodDecl->isVariadic() != MethodDecl->isVariadic()) {
2590  Diag(ImpMethodDecl->getLocation(),
2591  diag::warn_conflicting_variadic);
2592  Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
2593  }
2594 }
2595 
2597  ObjCMethodDecl *Overridden,
2598  bool IsProtocolMethodDecl) {
2599 
2600  CheckMethodOverrideReturn(*this, Method, Overridden,
2601  IsProtocolMethodDecl, true,
2602  true);
2603 
2604  for (ObjCMethodDecl::param_iterator IM = Method->param_begin(),
2605  IF = Overridden->param_begin(), EM = Method->param_end(),
2606  EF = Overridden->param_end();
2607  IM != EM && IF != EF; ++IM, ++IF) {
2608  CheckMethodOverrideParam(*this, Method, Overridden, *IM, *IF,
2609  IsProtocolMethodDecl, true, true);
2610  }
2611 
2612  if (Method->isVariadic() != Overridden->isVariadic()) {
2613  Diag(Method->getLocation(),
2614  diag::warn_conflicting_overriding_variadic);
2615  Diag(Overridden->getLocation(), diag::note_previous_declaration);
2616  }
2617 }
2618 
2619 /// WarnExactTypedMethods - This routine issues a warning if method
2620 /// implementation declaration matches exactly that of its declaration.
2622  ObjCMethodDecl *MethodDecl,
2623  bool IsProtocolMethodDecl) {
2624  // don't issue warning when protocol method is optional because primary
2625  // class is not required to implement it and it is safe for protocol
2626  // to implement it.
2628  return;
2629  // don't issue warning when primary class's method is
2630  // deprecated/unavailable.
2631  if (MethodDecl->hasAttr<UnavailableAttr>() ||
2632  MethodDecl->hasAttr<DeprecatedAttr>())
2633  return;
2634 
2635  bool match = CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
2636  IsProtocolMethodDecl, false, false);
2637  if (match)
2638  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
2639  IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
2640  EF = MethodDecl->param_end();
2641  IM != EM && IF != EF; ++IM, ++IF) {
2642  match = CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl,
2643  *IM, *IF,
2644  IsProtocolMethodDecl, false, false);
2645  if (!match)
2646  break;
2647  }
2648  if (match)
2649  match = (ImpMethodDecl->isVariadic() == MethodDecl->isVariadic());
2650  if (match)
2651  match = !(MethodDecl->isClassMethod() &&
2652  MethodDecl->getSelector() == GetNullarySelector("load", Context));
2653 
2654  if (match) {
2655  Diag(ImpMethodDecl->getLocation(),
2656  diag::warn_category_method_impl_match);
2657  Diag(MethodDecl->getLocation(), diag::note_method_declared_at)
2658  << MethodDecl->getDeclName();
2659  }
2660 }
2661 
2662 /// FIXME: Type hierarchies in Objective-C can be deep. We could most likely
2663 /// improve the efficiency of selector lookups and type checking by associating
2664 /// with each protocol / interface / category the flattened instance tables. If
2665 /// we used an immutable set to keep the table then it wouldn't add significant
2666 /// memory cost and it would be handy for lookups.
2667 
2669 typedef std::unique_ptr<ProtocolNameSet> LazyProtocolNameSet;
2670 
2672  ProtocolNameSet &PNS) {
2673  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2674  PNS.insert(PDecl->getIdentifier());
2675  for (const auto *PI : PDecl->protocols())
2677 }
2678 
2679 /// Recursively populates a set with all conformed protocols in a class
2680 /// hierarchy that have the 'objc_protocol_requires_explicit_implementation'
2681 /// attribute.
2683  ProtocolNameSet &PNS) {
2684  if (!Super)
2685  return;
2686 
2687  for (const auto *I : Super->all_referenced_protocols())
2689 
2691 }
2692 
2693 /// CheckProtocolMethodDefs - This routine checks unimplemented methods
2694 /// Declared in protocol, and those referenced by it.
2696  Sema &S, ObjCImplDecl *Impl, ObjCProtocolDecl *PDecl, bool &IncompleteImpl,
2697  const Sema::SelectorSet &InsMap, const Sema::SelectorSet &ClsMap,
2698  ObjCContainerDecl *CDecl, LazyProtocolNameSet &ProtocolsExplictImpl) {
2699  ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2700  ObjCInterfaceDecl *IDecl = C ? C->getClassInterface()
2701  : dyn_cast<ObjCInterfaceDecl>(CDecl);
2702  assert (IDecl && "CheckProtocolMethodDefs - IDecl is null");
2703 
2704  ObjCInterfaceDecl *Super = IDecl->getSuperClass();
2705  ObjCInterfaceDecl *NSIDecl = nullptr;
2706 
2707  // If this protocol is marked 'objc_protocol_requires_explicit_implementation'
2708  // then we should check if any class in the super class hierarchy also
2709  // conforms to this protocol, either directly or via protocol inheritance.
2710  // If so, we can skip checking this protocol completely because we
2711  // know that a parent class already satisfies this protocol.
2712  //
2713  // Note: we could generalize this logic for all protocols, and merely
2714  // add the limit on looking at the super class chain for just
2715  // specially marked protocols. This may be a good optimization. This
2716  // change is restricted to 'objc_protocol_requires_explicit_implementation'
2717  // protocols for now for controlled evaluation.
2718  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>()) {
2719  if (!ProtocolsExplictImpl) {
2720  ProtocolsExplictImpl.reset(new ProtocolNameSet);
2721  findProtocolsWithExplicitImpls(Super, *ProtocolsExplictImpl);
2722  }
2723  if (ProtocolsExplictImpl->contains(PDecl->getIdentifier()))
2724  return;
2725 
2726  // If no super class conforms to the protocol, we should not search
2727  // for methods in the super class to implicitly satisfy the protocol.
2728  Super = nullptr;
2729  }
2730 
2731  if (S.getLangOpts().ObjCRuntime.isNeXTFamily()) {
2732  // check to see if class implements forwardInvocation method and objects
2733  // of this class are derived from 'NSProxy' so that to forward requests
2734  // from one object to another.
2735  // Under such conditions, which means that every method possible is
2736  // implemented in the class, we should not issue "Method definition not
2737  // found" warnings.
2738  // FIXME: Use a general GetUnarySelector method for this.
2739  IdentifierInfo* II = &S.Context.Idents.get("forwardInvocation");
2740  Selector fISelector = S.Context.Selectors.getSelector(1, &II);
2741  if (InsMap.count(fISelector))
2742  // Is IDecl derived from 'NSProxy'? If so, no instance methods
2743  // need be implemented in the implementation.
2744  NSIDecl = IDecl->lookupInheritedClass(&S.Context.Idents.get("NSProxy"));
2745  }
2746 
2747  // If this is a forward protocol declaration, get its definition.
2748  if (!PDecl->isThisDeclarationADefinition() &&
2749  PDecl->getDefinition())
2750  PDecl = PDecl->getDefinition();
2751 
2752  // If a method lookup fails locally we still need to look and see if
2753  // the method was implemented by a base class or an inherited
2754  // protocol. This lookup is slow, but occurs rarely in correct code
2755  // and otherwise would terminate in a warning.
2756 
2757  // check unimplemented instance methods.
2758  if (!NSIDecl)
2759  for (auto *method : PDecl->instance_methods()) {
2760  if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
2761  !method->isPropertyAccessor() &&
2762  !InsMap.count(method->getSelector()) &&
2763  (!Super || !Super->lookupMethod(method->getSelector(),
2764  true /* instance */,
2765  false /* shallowCategory */,
2766  true /* followsSuper */,
2767  nullptr /* category */))) {
2768  // If a method is not implemented in the category implementation but
2769  // has been declared in its primary class, superclass,
2770  // or in one of their protocols, no need to issue the warning.
2771  // This is because method will be implemented in the primary class
2772  // or one of its super class implementation.
2773 
2774  // Ugly, but necessary. Method declared in protocol might have
2775  // have been synthesized due to a property declared in the class which
2776  // uses the protocol.
2777  if (ObjCMethodDecl *MethodInClass =
2778  IDecl->lookupMethod(method->getSelector(),
2779  true /* instance */,
2780  true /* shallowCategoryLookup */,
2781  false /* followSuper */))
2782  if (C || MethodInClass->isPropertyAccessor())
2783  continue;
2784  unsigned DIAG = diag::warn_unimplemented_protocol_method;
2785  if (!S.Diags.isIgnored(DIAG, Impl->getLocation())) {
2786  WarnUndefinedMethod(S, Impl, method, IncompleteImpl, DIAG, PDecl);
2787  }
2788  }
2789  }
2790  // check unimplemented class methods
2791  for (auto *method : PDecl->class_methods()) {
2792  if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
2793  !ClsMap.count(method->getSelector()) &&
2794  (!Super || !Super->lookupMethod(method->getSelector(),
2795  false /* class method */,
2796  false /* shallowCategoryLookup */,
2797  true /* followSuper */,
2798  nullptr /* category */))) {
2799  // See above comment for instance method lookups.
2800  if (C && IDecl->lookupMethod(method->getSelector(),
2801  false /* class */,
2802  true /* shallowCategoryLookup */,
2803  false /* followSuper */))
2804  continue;
2805 
2806  unsigned DIAG = diag::warn_unimplemented_protocol_method;
2807  if (!S.Diags.isIgnored(DIAG, Impl->getLocation())) {
2808  WarnUndefinedMethod(S, Impl, method, IncompleteImpl, DIAG, PDecl);
2809  }
2810  }
2811  }
2812  // Check on this protocols's referenced protocols, recursively.
2813  for (auto *PI : PDecl->protocols())
2814  CheckProtocolMethodDefs(S, Impl, PI, IncompleteImpl, InsMap, ClsMap, CDecl,
2815  ProtocolsExplictImpl);
2816 }
2817 
2818 /// MatchAllMethodDeclarations - Check methods declared in interface
2819 /// or protocol against those declared in their implementations.
2820 ///
2822  const SelectorSet &ClsMap,
2823  SelectorSet &InsMapSeen,
2824  SelectorSet &ClsMapSeen,
2825  ObjCImplDecl* IMPDecl,
2826  ObjCContainerDecl* CDecl,
2827  bool &IncompleteImpl,
2828  bool ImmediateClass,
2829  bool WarnCategoryMethodImpl) {
2830  // Check and see if instance methods in class interface have been
2831  // implemented in the implementation class. If so, their types match.
2832  for (auto *I : CDecl->instance_methods()) {
2833  if (!InsMapSeen.insert(I->getSelector()).second)
2834  continue;
2835  if (!I->isPropertyAccessor() &&
2836  !InsMap.count(I->getSelector())) {
2837  if (ImmediateClass)
2838  WarnUndefinedMethod(*this, IMPDecl, I, IncompleteImpl,
2839  diag::warn_undef_method_impl);
2840  continue;
2841  } else {
2842  ObjCMethodDecl *ImpMethodDecl =
2843  IMPDecl->getInstanceMethod(I->getSelector());
2844  assert(CDecl->getInstanceMethod(I->getSelector(), true/*AllowHidden*/) &&
2845  "Expected to find the method through lookup as well");
2846  // ImpMethodDecl may be null as in a @dynamic property.
2847  if (ImpMethodDecl) {
2848  // Skip property accessor function stubs.
2849  if (ImpMethodDecl->isSynthesizedAccessorStub())
2850  continue;
2851  if (!WarnCategoryMethodImpl)
2852  WarnConflictingTypedMethods(ImpMethodDecl, I,
2853  isa<ObjCProtocolDecl>(CDecl));
2854  else if (!I->isPropertyAccessor())
2855  WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
2856  }
2857  }
2858  }
2859 
2860  // Check and see if class methods in class interface have been
2861  // implemented in the implementation class. If so, their types match.
2862  for (auto *I : CDecl->class_methods()) {
2863  if (!ClsMapSeen.insert(I->getSelector()).second)
2864  continue;
2865  if (!I->isPropertyAccessor() &&
2866  !ClsMap.count(I->getSelector())) {
2867  if (ImmediateClass)
2868  WarnUndefinedMethod(*this, IMPDecl, I, IncompleteImpl,
2869  diag::warn_undef_method_impl);
2870  } else {
2871  ObjCMethodDecl *ImpMethodDecl =
2872  IMPDecl->getClassMethod(I->getSelector());
2873  assert(CDecl->getClassMethod(I->getSelector(), true/*AllowHidden*/) &&
2874  "Expected to find the method through lookup as well");
2875  // ImpMethodDecl may be null as in a @dynamic property.
2876  if (ImpMethodDecl) {
2877  // Skip property accessor function stubs.
2878  if (ImpMethodDecl->isSynthesizedAccessorStub())
2879  continue;
2880  if (!WarnCategoryMethodImpl)
2881  WarnConflictingTypedMethods(ImpMethodDecl, I,
2882  isa<ObjCProtocolDecl>(CDecl));
2883  else if (!I->isPropertyAccessor())
2884  WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
2885  }
2886  }
2887  }
2888 
2889  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl> (CDecl)) {
2890  // Also, check for methods declared in protocols inherited by
2891  // this protocol.
2892  for (auto *PI : PD->protocols())
2893  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2894  IMPDecl, PI, IncompleteImpl, false,
2895  WarnCategoryMethodImpl);
2896  }
2897 
2898  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
2899  // when checking that methods in implementation match their declaration,
2900  // i.e. when WarnCategoryMethodImpl is false, check declarations in class
2901  // extension; as well as those in categories.
2902  if (!WarnCategoryMethodImpl) {
2903  for (auto *Cat : I->visible_categories())
2904  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2905  IMPDecl, Cat, IncompleteImpl,
2906  ImmediateClass && Cat->IsClassExtension(),
2907  WarnCategoryMethodImpl);
2908  } else {
2909  // Also methods in class extensions need be looked at next.
2910  for (auto *Ext : I->visible_extensions())
2911  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2912  IMPDecl, Ext, IncompleteImpl, false,
2913  WarnCategoryMethodImpl);
2914  }
2915 
2916  // Check for any implementation of a methods declared in protocol.
2917  for (auto *PI : I->all_referenced_protocols())
2918  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2919  IMPDecl, PI, IncompleteImpl, false,
2920  WarnCategoryMethodImpl);
2921 
2922  // FIXME. For now, we are not checking for exact match of methods
2923  // in category implementation and its primary class's super class.
2924  if (!WarnCategoryMethodImpl && I->getSuperClass())
2925  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2926  IMPDecl,
2927  I->getSuperClass(), IncompleteImpl, false);
2928  }
2929 }
2930 
2931 /// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
2932 /// category matches with those implemented in its primary class and
2933 /// warns each time an exact match is found.
2935  ObjCCategoryImplDecl *CatIMPDecl) {
2936  // Get category's primary class.
2937  ObjCCategoryDecl *CatDecl = CatIMPDecl->getCategoryDecl();
2938  if (!CatDecl)
2939  return;
2940  ObjCInterfaceDecl *IDecl = CatDecl->getClassInterface();
2941  if (!IDecl)
2942  return;
2943  ObjCInterfaceDecl *SuperIDecl = IDecl->getSuperClass();
2944  SelectorSet InsMap, ClsMap;
2945 
2946  for (const auto *I : CatIMPDecl->instance_methods()) {
2947  Selector Sel = I->getSelector();
2948  // When checking for methods implemented in the category, skip over
2949  // those declared in category class's super class. This is because
2950  // the super class must implement the method.
2951  if (SuperIDecl && SuperIDecl->lookupMethod(Sel, true))
2952  continue;
2953  InsMap.insert(Sel);
2954  }
2955 
2956  for (const auto *I : CatIMPDecl->class_methods()) {
2957  Selector Sel = I->getSelector();
2958  if (SuperIDecl && SuperIDecl->lookupMethod(Sel, false))
2959  continue;
2960  ClsMap.insert(Sel);
2961  }
2962  if (InsMap.empty() && ClsMap.empty())
2963  return;
2964 
2965  SelectorSet InsMapSeen, ClsMapSeen;
2966  bool IncompleteImpl = false;
2967  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2968  CatIMPDecl, IDecl,
2969  IncompleteImpl, false,
2970  true /*WarnCategoryMethodImpl*/);
2971 }
2972 
2974  ObjCContainerDecl* CDecl,
2975  bool IncompleteImpl) {
2976  SelectorSet InsMap;
2977  // Check and see if instance methods in class interface have been
2978  // implemented in the implementation class.
2979  for (const auto *I : IMPDecl->instance_methods())
2980  InsMap.insert(I->getSelector());
2981 
2982  // Add the selectors for getters/setters of @dynamic properties.
2983  for (const auto *PImpl : IMPDecl->property_impls()) {
2984  // We only care about @dynamic implementations.
2985  if (PImpl->getPropertyImplementation() != ObjCPropertyImplDecl::Dynamic)
2986  continue;
2987 
2988  const auto *P = PImpl->getPropertyDecl();
2989  if (!P) continue;
2990 
2991  InsMap.insert(P->getGetterName());
2992  if (!P->getSetterName().isNull())
2993  InsMap.insert(P->getSetterName());
2994  }
2995 
2996  // Check and see if properties declared in the interface have either 1)
2997  // an implementation or 2) there is a @synthesize/@dynamic implementation
2998  // of the property in the @implementation.
2999  if (const ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
3000  bool SynthesizeProperties = LangOpts.ObjCDefaultSynthProperties &&
3002  !IDecl->isObjCRequiresPropertyDefs();
3003  DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, SynthesizeProperties);
3004  }
3005 
3006  // Diagnose null-resettable synthesized setters.
3008 
3009  SelectorSet ClsMap;
3010  for (const auto *I : IMPDecl->class_methods())
3011  ClsMap.insert(I->getSelector());
3012 
3013  // Check for type conflict of methods declared in a class/protocol and
3014  // its implementation; if any.
3015  SelectorSet InsMapSeen, ClsMapSeen;
3016  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
3017  IMPDecl, CDecl,
3018  IncompleteImpl, true);
3019 
3020  // check all methods implemented in category against those declared
3021  // in its primary class.
3022  if (ObjCCategoryImplDecl *CatDecl =
3023  dyn_cast<ObjCCategoryImplDecl>(IMPDecl))
3025 
3026  // Check the protocol list for unimplemented methods in the @implementation
3027  // class.
3028  // Check and see if class methods in class interface have been
3029  // implemented in the implementation class.
3030 
3031  LazyProtocolNameSet ExplicitImplProtocols;
3032 
3033  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
3034  for (auto *PI : I->all_referenced_protocols())
3035  CheckProtocolMethodDefs(*this, IMPDecl, PI, IncompleteImpl, InsMap,
3036  ClsMap, I, ExplicitImplProtocols);
3037  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
3038  // For extended class, unimplemented methods in its protocols will
3039  // be reported in the primary class.
3040  if (!C->IsClassExtension()) {
3041  for (auto *P : C->protocols())
3042  CheckProtocolMethodDefs(*this, IMPDecl, P, IncompleteImpl, InsMap,
3043  ClsMap, CDecl, ExplicitImplProtocols);
3044  DiagnoseUnimplementedProperties(S, IMPDecl, CDecl,
3045  /*SynthesizeProperties=*/false);
3046  }
3047  } else
3048  llvm_unreachable("invalid ObjCContainerDecl type.");
3049 }
3050 
3053  IdentifierInfo **IdentList,
3054  SourceLocation *IdentLocs,
3055  ArrayRef<ObjCTypeParamList *> TypeParamLists,
3056  unsigned NumElts) {
3057  SmallVector<Decl *, 8> DeclsInGroup;
3058  for (unsigned i = 0; i != NumElts; ++i) {
3059  // Check for another declaration kind with the same name.
3060  NamedDecl *PrevDecl
3061  = LookupSingleName(TUScope, IdentList[i], IdentLocs[i],
3063  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
3064  // GCC apparently allows the following idiom:
3065  //
3066  // typedef NSObject < XCElementTogglerP > XCElementToggler;
3067  // @class XCElementToggler;
3068  //
3069  // Here we have chosen to ignore the forward class declaration
3070  // with a warning. Since this is the implied behavior.
3071  TypedefNameDecl *TDD = dyn_cast<TypedefNameDecl>(PrevDecl);
3072  if (!TDD || !TDD->getUnderlyingType()->isObjCObjectType()) {
3073  Diag(AtClassLoc, diag::err_redefinition_different_kind) << IdentList[i];
3074  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3075  } else {
3076  // a forward class declaration matching a typedef name of a class refers
3077  // to the underlying class. Just ignore the forward class with a warning
3078  // as this will force the intended behavior which is to lookup the
3079  // typedef name.
3080  if (isa<ObjCObjectType>(TDD->getUnderlyingType())) {
3081  Diag(AtClassLoc, diag::warn_forward_class_redefinition)
3082  << IdentList[i];
3083  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3084  continue;
3085  }
3086  }
3087  }
3088 
3089  // Create a declaration to describe this forward declaration.
3090  ObjCInterfaceDecl *PrevIDecl
3091  = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
3092 
3093  IdentifierInfo *ClassName = IdentList[i];
3094  if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) {
3095  // A previous decl with a different name is because of
3096  // @compatibility_alias, for example:
3097  // \code
3098  // @class NewImage;
3099  // @compatibility_alias OldImage NewImage;
3100  // \endcode
3101  // A lookup for 'OldImage' will return the 'NewImage' decl.
3102  //
3103  // In such a case use the real declaration name, instead of the alias one,
3104  // otherwise we will break IdentifierResolver and redecls-chain invariants.
3105  // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl
3106  // has been aliased.
3107  ClassName = PrevIDecl->getIdentifier();
3108  }
3109 
3110  // If this forward declaration has type parameters, compare them with the
3111  // type parameters of the previous declaration.
3112  ObjCTypeParamList *TypeParams = TypeParamLists[i];
3113  if (PrevIDecl && TypeParams) {
3114  if (ObjCTypeParamList *PrevTypeParams = PrevIDecl->getTypeParamList()) {
3115  // Check for consistency with the previous declaration.
3117  *this, PrevTypeParams, TypeParams,
3118  TypeParamListContext::ForwardDeclaration)) {
3119  TypeParams = nullptr;
3120  }
3121  } else if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
3122  // The @interface does not have type parameters. Complain.
3123  Diag(IdentLocs[i], diag::err_objc_parameterized_forward_class)
3124  << ClassName
3125  << TypeParams->getSourceRange();
3126  Diag(Def->getLocation(), diag::note_defined_here)
3127  << ClassName;
3128 
3129  TypeParams = nullptr;
3130  }
3131  }
3132 
3133  ObjCInterfaceDecl *IDecl
3135  ClassName, TypeParams, PrevIDecl,
3136  IdentLocs[i]);
3137  IDecl->setAtEndRange(IdentLocs[i]);
3138 
3139  if (PrevIDecl)
3140  mergeDeclAttributes(IDecl, PrevIDecl);
3141 
3142  PushOnScopeChains(IDecl, TUScope);
3143  CheckObjCDeclScope(IDecl);
3144  DeclsInGroup.push_back(IDecl);
3145  }
3146 
3147  return BuildDeclaratorGroup(DeclsInGroup);
3148 }
3149 
3150 static bool tryMatchRecordTypes(ASTContext &Context,
3151  Sema::MethodMatchStrategy strategy,
3152  const Type *left, const Type *right);
3153 
3154 static bool matchTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy,
3155  QualType leftQT, QualType rightQT) {
3156  const Type *left =
3157  Context.getCanonicalType(leftQT).getUnqualifiedType().getTypePtr();
3158  const Type *right =
3159  Context.getCanonicalType(rightQT).getUnqualifiedType().getTypePtr();
3160 
3161  if (left == right) return true;
3162 
3163  // If we're doing a strict match, the types have to match exactly.
3164  if (strategy == Sema::MMS_strict) return false;
3165 
3166  if (left->isIncompleteType() || right->isIncompleteType()) return false;
3167 
3168  // Otherwise, use this absurdly complicated algorithm to try to
3169  // validate the basic, low-level compatibility of the two types.
3170 
3171  // As a minimum, require the sizes and alignments to match.
3172  TypeInfo LeftTI = Context.getTypeInfo(left);
3173  TypeInfo RightTI = Context.getTypeInfo(right);
3174  if (LeftTI.Width != RightTI.Width)
3175  return false;
3176 
3177  if (LeftTI.Align != RightTI.Align)
3178  return false;
3179 
3180  // Consider all the kinds of non-dependent canonical types:
3181  // - functions and arrays aren't possible as return and parameter types
3182 
3183  // - vector types of equal size can be arbitrarily mixed
3184  if (isa<VectorType>(left)) return isa<VectorType>(right);
3185  if (isa<VectorType>(right)) return false;
3186 
3187  // - references should only match references of identical type
3188  // - structs, unions, and Objective-C objects must match more-or-less
3189  // exactly
3190  // - everything else should be a scalar
3191  if (!left->isScalarType() || !right->isScalarType())
3192  return tryMatchRecordTypes(Context, strategy, left, right);
3193 
3194  // Make scalars agree in kind, except count bools as chars, and group
3195  // all non-member pointers together.
3196  Type::ScalarTypeKind leftSK = left->getScalarTypeKind();
3197  Type::ScalarTypeKind rightSK = right->getScalarTypeKind();
3198  if (leftSK == Type::STK_Bool) leftSK = Type::STK_Integral;
3199  if (rightSK == Type::STK_Bool) rightSK = Type::STK_Integral;
3200  if (leftSK == Type::STK_CPointer || leftSK == Type::STK_BlockPointer)
3201  leftSK = Type::STK_ObjCObjectPointer;
3202  if (rightSK == Type::STK_CPointer || rightSK == Type::STK_BlockPointer)
3203  rightSK = Type::STK_ObjCObjectPointer;
3204 
3205  // Note that data member pointers and function member pointers don't
3206  // intermix because of the size differences.
3207 
3208  return (leftSK == rightSK);
3209 }
3210 
3211 static bool tryMatchRecordTypes(ASTContext &Context,
3212  Sema::MethodMatchStrategy strategy,
3213  const Type *lt, const Type *rt) {
3214  assert(lt && rt && lt != rt);
3215 
3216  if (!isa<RecordType>(lt) || !isa<RecordType>(rt)) return false;
3217  RecordDecl *left = cast<RecordType>(lt)->getDecl();
3218  RecordDecl *right = cast<RecordType>(rt)->getDecl();
3219 
3220  // Require union-hood to match.
3221  if (left->isUnion() != right->isUnion()) return false;
3222 
3223  // Require an exact match if either is non-POD.
3224  if ((isa<CXXRecordDecl>(left) && !cast<CXXRecordDecl>(left)->isPOD()) ||
3225  (isa<CXXRecordDecl>(right) && !cast<CXXRecordDecl>(right)->isPOD()))
3226  return false;
3227 
3228  // Require size and alignment to match.
3229  TypeInfo LeftTI = Context.getTypeInfo(lt);
3230  TypeInfo RightTI = Context.getTypeInfo(rt);
3231  if (LeftTI.Width != RightTI.Width)
3232  return false;
3233 
3234  if (LeftTI.Align != RightTI.Align)
3235  return false;
3236 
3237  // Require fields to match.
3238  RecordDecl::field_iterator li = left->field_begin(), le = left->field_end();
3239  RecordDecl::field_iterator ri = right->field_begin(), re = right->field_end();
3240  for (; li != le && ri != re; ++li, ++ri) {
3241  if (!matchTypes(Context, strategy, li->getType(), ri->getType()))
3242  return false;
3243  }
3244  return (li == le && ri == re);
3245 }
3246 
3247 /// MatchTwoMethodDeclarations - Checks that two methods have matching type and
3248 /// returns true, or false, accordingly.
3249 /// TODO: Handle protocol list; such as id<p1,p2> in type comparisons
3251  const ObjCMethodDecl *right,
3252  MethodMatchStrategy strategy) {
3253  if (!matchTypes(Context, strategy, left->getReturnType(),
3254  right->getReturnType()))
3255  return false;
3256 
3257  // If either is hidden, it is not considered to match.
3258  if (!left->isUnconditionallyVisible() || !right->isUnconditionallyVisible())
3259  return false;
3260 
3261  if (left->isDirectMethod() != right->isDirectMethod())
3262  return false;
3263 
3264  if (getLangOpts().ObjCAutoRefCount &&
3265  (left->hasAttr<NSReturnsRetainedAttr>()
3266  != right->hasAttr<NSReturnsRetainedAttr>() ||
3267  left->hasAttr<NSConsumesSelfAttr>()
3268  != right->hasAttr<NSConsumesSelfAttr>()))
3269  return false;
3270 
3272  li = left->param_begin(), le = left->param_end(), ri = right->param_begin(),
3273  re = right->param_end();
3274 
3275  for (; li != le && ri != re; ++li, ++ri) {
3276  assert(ri != right->param_end() && "Param mismatch");
3277  const ParmVarDecl *lparm = *li, *rparm = *ri;
3278 
3279  if (!matchTypes(Context, strategy, lparm->getType(), rparm->getType()))
3280  return false;
3281 
3282  if (getLangOpts().ObjCAutoRefCount &&
3283  lparm->hasAttr<NSConsumedAttr>() != rparm->hasAttr<NSConsumedAttr>())
3284  return false;
3285  }
3286  return true;
3287 }
3288 
3290  ObjCMethodDecl *MethodInList) {
3291  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
3292  auto *MethodInListProtocol =
3293  dyn_cast<ObjCProtocolDecl>(MethodInList->getDeclContext());
3294  // If this method belongs to a protocol but the method in list does not, or
3295  // vice versa, we say the context is not the same.
3296  if ((MethodProtocol && !MethodInListProtocol) ||
3297  (!MethodProtocol && MethodInListProtocol))
3298  return false;
3299 
3300  if (MethodProtocol && MethodInListProtocol)
3301  return true;
3302 
3303  ObjCInterfaceDecl *MethodInterface = Method->getClassInterface();
3304  ObjCInterfaceDecl *MethodInListInterface =
3305  MethodInList->getClassInterface();
3306  return MethodInterface == MethodInListInterface;
3307 }
3308 
3310  ObjCMethodDecl *Method) {
3311  // Record at the head of the list whether there were 0, 1, or >= 2 methods
3312  // inside categories.
3313  if (ObjCCategoryDecl *CD =
3314  dyn_cast<ObjCCategoryDecl>(Method->getDeclContext()))
3315  if (!CD->IsClassExtension() && List->getBits() < 2)
3316  List->setBits(List->getBits() + 1);
3317 
3318  // If the list is empty, make it a singleton list.
3319  if (List->getMethod() == nullptr) {
3320  List->setMethod(Method);
3321  List->setNext(nullptr);
3322  return;
3323  }
3324 
3325  // We've seen a method with this name, see if we have already seen this type
3326  // signature.
3327  ObjCMethodList *Previous = List;
3328  ObjCMethodList *ListWithSameDeclaration = nullptr;
3329  for (; List; Previous = List, List = List->getNext()) {
3330  // If we are building a module, keep all of the methods.
3331  if (getLangOpts().isCompilingModule())
3332  continue;
3333 
3334  bool SameDeclaration = MatchTwoMethodDeclarations(Method,
3335  List->getMethod());
3336  // Looking for method with a type bound requires the correct context exists.
3337  // We need to insert a method into the list if the context is different.
3338  // If the method's declaration matches the list
3339  // a> the method belongs to a different context: we need to insert it, in
3340  // order to emit the availability message, we need to prioritize over
3341  // availability among the methods with the same declaration.
3342  // b> the method belongs to the same context: there is no need to insert a
3343  // new entry.
3344  // If the method's declaration does not match the list, we insert it to the
3345  // end.
3346  if (!SameDeclaration ||
3347  !isMethodContextSameForKindofLookup(Method, List->getMethod())) {
3348  // Even if two method types do not match, we would like to say
3349  // there is more than one declaration so unavailability/deprecated
3350  // warning is not too noisy.
3351  if (!Method->isDefined())
3352  List->setHasMoreThanOneDecl(true);
3353 
3354  // For methods with the same declaration, the one that is deprecated
3355  // should be put in the front for better diagnostics.
3356  if (Method->isDeprecated() && SameDeclaration &&
3357  !ListWithSameDeclaration && !List->getMethod()->isDeprecated())
3358  ListWithSameDeclaration = List;
3359 
3360  if (Method->isUnavailable() && SameDeclaration &&
3361  !ListWithSameDeclaration &&
3362  List->getMethod()->getAvailability() < AR_Deprecated)
3363  ListWithSameDeclaration = List;
3364  continue;
3365  }
3366 
3367  ObjCMethodDecl *PrevObjCMethod = List->getMethod();
3368 
3369  // Propagate the 'defined' bit.
3370  if (Method->isDefined())
3371  PrevObjCMethod->setDefined(true);
3372  else {
3373  // Objective-C doesn't allow an @interface for a class after its
3374  // @implementation. So if Method is not defined and there already is
3375  // an entry for this type signature, Method has to be for a different
3376  // class than PrevObjCMethod.
3377  List->setHasMoreThanOneDecl(true);
3378  }
3379 
3380  // If a method is deprecated, push it in the global pool.
3381  // This is used for better diagnostics.
3382  if (Method->isDeprecated()) {
3383  if (!PrevObjCMethod->isDeprecated())
3384  List->setMethod(Method);
3385  }
3386  // If the new method is unavailable, push it into global pool
3387  // unless previous one is deprecated.
3388  if (Method->isUnavailable()) {
3389  if (PrevObjCMethod->getAvailability() < AR_Deprecated)
3390  List->setMethod(Method);
3391  }
3392 
3393  return;
3394  }
3395 
3396  // We have a new signature for an existing method - add it.
3397  // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
3398  ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
3399 
3400  // We insert it right before ListWithSameDeclaration.
3401  if (ListWithSameDeclaration) {
3402  auto *List = new (Mem) ObjCMethodList(*ListWithSameDeclaration);
3403  // FIXME: should we clear the other bits in ListWithSameDeclaration?
3404  ListWithSameDeclaration->setMethod(Method);
3405  ListWithSameDeclaration->setNext(List);
3406  return;
3407  }
3408 
3409  Previous->setNext(new (Mem) ObjCMethodList(Method));
3410 }
3411 
3412 /// Read the contents of the method pool for a given selector from
3413 /// external storage.
3415  assert(ExternalSource && "We need an external AST source");
3416  ExternalSource->ReadMethodPool(Sel);
3417 }
3418 
3420  if (!ExternalSource)
3421  return;
3422  ExternalSource->updateOutOfDateSelector(Sel);
3423 }
3424 
3425 void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
3426  bool instance) {
3427  // Ignore methods of invalid containers.
3428  if (cast<Decl>(Method->getDeclContext())->isInvalidDecl())
3429  return;
3430 
3431  if (ExternalSource)
3432  ReadMethodPool(Method->getSelector());
3433 
3435  if (Pos == MethodPool.end())
3436  Pos = MethodPool
3437  .insert(std::make_pair(Method->getSelector(),
3439  .first;
3440 
3441  Method->setDefined(impl);
3442 
3443  ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second;
3444  addMethodToGlobalList(&Entry, Method);
3445 }
3446 
3447 /// Determines if this is an "acceptable" loose mismatch in the global
3448 /// method pool. This exists mostly as a hack to get around certain
3449 /// global mismatches which we can't afford to make warnings / errors.
3450 /// Really, what we want is a way to take a method out of the global
3451 /// method pool.
3453  ObjCMethodDecl *other) {
3454  if (!chosen->isInstanceMethod())
3455  return false;
3456 
3457  if (chosen->isDirectMethod() != other->isDirectMethod())
3458  return false;
3459 
3460  Selector sel = chosen->getSelector();
3461  if (!sel.isUnarySelector() || sel.getNameForSlot(0) != "length")
3462  return false;
3463 
3464  // Don't complain about mismatches for -length if the method we
3465  // chose has an integral result type.
3466  return (chosen->getReturnType()->isIntegerType());
3467 }
3468 
3469 /// Return true if the given method is wthin the type bound.
3471  const ObjCObjectType *TypeBound) {
3472  if (!TypeBound)
3473  return true;
3474 
3475  if (TypeBound->isObjCId())
3476  // FIXME: should we handle the case of bounding to id<A, B> differently?
3477  return true;
3478 
3479  auto *BoundInterface = TypeBound->getInterface();
3480  assert(BoundInterface && "unexpected object type!");
3481 
3482  // Check if the Method belongs to a protocol. We should allow any method
3483  // defined in any protocol, because any subclass could adopt the protocol.
3484  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
3485  if (MethodProtocol) {
3486  return true;
3487  }
3488 
3489  // If the Method belongs to a class, check if it belongs to the class
3490  // hierarchy of the class bound.
3491  if (ObjCInterfaceDecl *MethodInterface = Method->getClassInterface()) {
3492  // We allow methods declared within classes that are part of the hierarchy
3493  // of the class bound (superclass of, subclass of, or the same as the class
3494  // bound).
3495  return MethodInterface == BoundInterface ||
3496  MethodInterface->isSuperClassOf(BoundInterface) ||
3497  BoundInterface->isSuperClassOf(MethodInterface);
3498  }
3499  llvm_unreachable("unknown method context");
3500 }
3501 
3502 /// We first select the type of the method: Instance or Factory, then collect
3503 /// all methods with that type.
3506  bool InstanceFirst, bool CheckTheOther,
3507  const ObjCObjectType *TypeBound) {
3508  if (ExternalSource)
3509  ReadMethodPool(Sel);
3510 
3512  if (Pos == MethodPool.end())
3513  return false;
3514 
3515  // Gather the non-hidden methods.
3516  ObjCMethodList &MethList = InstanceFirst ? Pos->second.first :
3517  Pos->second.second;
3518  for (ObjCMethodList *M = &MethList; M; M = M->getNext())
3519  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible()) {
3520  if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
3521  Methods.push_back(M->getMethod());
3522  }
3523 
3524  // Return if we find any method with the desired kind.
3525  if (!Methods.empty())
3526  return Methods.size() > 1;
3527 
3528  if (!CheckTheOther)
3529  return false;
3530 
3531  // Gather the other kind.
3532  ObjCMethodList &MethList2 = InstanceFirst ? Pos->second.second :
3533  Pos->second.first;
3534  for (ObjCMethodList *M = &MethList2; M; M = M->getNext())
3535  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible()) {
3536  if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
3537  Methods.push_back(M->getMethod());
3538  }
3539 
3540  return Methods.size() > 1;
3541 }
3542 
3544  Selector Sel, ObjCMethodDecl *BestMethod, SourceRange R,
3545  bool receiverIdOrClass, SmallVectorImpl<ObjCMethodDecl *> &Methods) {
3546  // Diagnose finding more than one method in global pool.
3547  SmallVector<ObjCMethodDecl *, 4> FilteredMethods;
3548  FilteredMethods.push_back(BestMethod);
3549 
3550  for (auto *M : Methods)
3551  if (M != BestMethod && !M->hasAttr<UnavailableAttr>())
3552  FilteredMethods.push_back(M);
3553 
3554  if (FilteredMethods.size() > 1)
3555  DiagnoseMultipleMethodInGlobalPool(FilteredMethods, Sel, R,
3556  receiverIdOrClass);
3557 
3559  // Test for no method in the pool which should not trigger any warning by
3560  // caller.
3561  if (Pos == MethodPool.end())
3562  return true;
3563  ObjCMethodList &MethList =
3564  BestMethod->isInstanceMethod() ? Pos->second.first : Pos->second.second;
3565  return MethList.hasMoreThanOneDecl();
3566 }
3567 
3568 ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R,
3569  bool receiverIdOrClass,
3570  bool instance) {
3571  if (ExternalSource)
3572  ReadMethodPool(Sel);
3573 
3575  if (Pos == MethodPool.end())
3576  return nullptr;
3577 
3578  // Gather the non-hidden methods.
3579  ObjCMethodList &MethList = instance ? Pos->second.first : Pos->second.second;
3581  for (ObjCMethodList *M = &MethList; M; M = M->getNext()) {
3582  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible())
3583  return M->getMethod();
3584  }
3585  return nullptr;
3586 }
3587 
3589  Selector Sel, SourceRange R,
3590  bool receiverIdOrClass) {
3591  // We found multiple methods, so we may have to complain.
3592  bool issueDiagnostic = false, issueError = false;
3593 
3594  // We support a warning which complains about *any* difference in
3595  // method signature.
3596  bool strictSelectorMatch =
3597  receiverIdOrClass &&
3598  !Diags.isIgnored(diag::warn_strict_multiple_method_decl, R.getBegin());
3599  if (strictSelectorMatch) {
3600  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3601  if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_strict)) {
3602  issueDiagnostic = true;
3603  break;
3604  }
3605  }
3606  }
3607 
3608  // If we didn't see any strict differences, we won't see any loose
3609  // differences. In ARC, however, we also need to check for loose
3610  // mismatches, because most of them are errors.
3611  if (!strictSelectorMatch ||
3612  (issueDiagnostic && getLangOpts().ObjCAutoRefCount))
3613  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3614  // This checks if the methods differ in type mismatch.
3615  if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_loose) &&
3616  !isAcceptableMethodMismatch(Methods[0], Methods[I])) {
3617  issueDiagnostic = true;
3618  if (getLangOpts().ObjCAutoRefCount)
3619  issueError = true;
3620  break;
3621  }
3622  }
3623 
3624  if (issueDiagnostic) {
3625  if (issueError)
3626  Diag(R.getBegin(), diag::err_arc_multiple_method_decl) << Sel << R;
3627  else if (strictSelectorMatch)
3628  Diag(R.getBegin(), diag::warn_strict_multiple_method_decl) << Sel << R;
3629  else
3630  Diag(R.getBegin(), diag::warn_multiple_method_decl) << Sel << R;
3631 
3632  Diag(Methods[0]->getBeginLoc(),
3633  issueError ? diag::note_possibility : diag::note_using)
3634  << Methods[0]->getSourceRange();
3635  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3636  Diag(Methods[I]->getBeginLoc(), diag::note_also_found)
3637  << Methods[I]->getSourceRange();
3638  }
3639  }
3640 }
3641 
3644  if (Pos == MethodPool.end())
3645  return nullptr;
3646 
3647  GlobalMethodPool::Lists &Methods = Pos->second;
3648  for (const ObjCMethodList *Method = &Methods.first; Method;
3649  Method = Method->getNext())
3650  if (Method->getMethod() &&
3651  (Method->getMethod()->isDefined() ||
3652  Method->getMethod()->isPropertyAccessor()))
3653  return Method->getMethod();
3654 
3655  for (const ObjCMethodList *Method = &Methods.second; Method;
3656  Method = Method->getNext())
3657  if (Method->getMethod() &&
3658  (Method->getMethod()->isDefined() ||
3659  Method->getMethod()->isPropertyAccessor()))
3660  return Method->getMethod();
3661  return nullptr;
3662 }
3663 
3664 static void
3667  StringRef Typo, const ObjCMethodDecl * Method) {
3668  const unsigned MaxEditDistance = 1;
3669  unsigned BestEditDistance = MaxEditDistance + 1;
3670  std::string MethodName = Method->getSelector().getAsString();
3671 
3672  unsigned MinPossibleEditDistance = abs((int)MethodName.size() - (int)Typo.size());
3673  if (MinPossibleEditDistance > 0 &&
3674  Typo.size() / MinPossibleEditDistance < 1)
3675  return;
3676  unsigned EditDistance = Typo.edit_distance(MethodName, true, MaxEditDistance);
3677  if (EditDistance > MaxEditDistance)
3678  return;
3679  if (EditDistance == BestEditDistance)
3680  BestMethod.push_back(Method);
3681  else if (EditDistance < BestEditDistance) {
3682  BestMethod.clear();
3683  BestMethod.push_back(Method);
3684  }
3685 }
3686 
3688  QualType ObjectType) {
3689  if (ObjectType.isNull())
3690  return true;
3691  if (S.LookupMethodInObjectType(Sel, ObjectType, true/*Instance method*/))
3692  return true;
3693  return S.LookupMethodInObjectType(Sel, ObjectType, false/*Class method*/) !=
3694  nullptr;
3695 }
3696 
3697 const ObjCMethodDecl *
3699  QualType ObjectType) {
3700  unsigned NumArgs = Sel.getNumArgs();
3702  bool ObjectIsId = true, ObjectIsClass = true;
3703  if (ObjectType.isNull())
3704  ObjectIsId = ObjectIsClass = false;
3705  else if (!ObjectType->isObjCObjectPointerType())
3706  return nullptr;
3707  else if (const ObjCObjectPointerType *ObjCPtr =
3708  ObjectType->getAsObjCInterfacePointerType()) {
3709  ObjectType = QualType(ObjCPtr->getInterfaceType(), 0);
3710  ObjectIsId = ObjectIsClass = false;
3711  }
3712  else if (ObjectType->isObjCIdType() || ObjectType->isObjCQualifiedIdType())
3713  ObjectIsClass = false;
3714  else if (ObjectType->isObjCClassType() || ObjectType->isObjCQualifiedClassType())
3715  ObjectIsId = false;
3716  else
3717  return nullptr;
3718 
3720  e = MethodPool.end(); b != e; b++) {
3721  // instance methods
3722  for (ObjCMethodList *M = &b->second.first; M; M=M->getNext())
3723  if (M->getMethod() &&
3724  (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
3725  (M->getMethod()->getSelector() != Sel)) {
3726  if (ObjectIsId)
3727  Methods.push_back(M->getMethod());
3728  else if (!ObjectIsClass &&
3729  HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
3730  ObjectType))
3731  Methods.push_back(M->getMethod());
3732  }
3733  // class methods
3734  for (ObjCMethodList *M = &b->second.second; M; M=M->getNext())
3735  if (M->getMethod() &&
3736  (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
3737  (M->getMethod()->getSelector() != Sel)) {
3738  if (ObjectIsClass)
3739  Methods.push_back(M->getMethod());
3740  else if (!ObjectIsId &&
3741  HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
3742  ObjectType))
3743  Methods.push_back(M->getMethod());
3744  }
3745  }
3746 
3748  for (unsigned i = 0, e = Methods.size(); i < e; i++) {
3749  HelperSelectorsForTypoCorrection(SelectedMethods,
3750  Sel.getAsString(), Methods[i]);
3751  }
3752  return (SelectedMethods.size() == 1) ? SelectedMethods[0] : nullptr;
3753 }
3754 
3755 /// DiagnoseDuplicateIvars -
3756 /// Check for duplicate ivars in the entire class at the start of
3757 /// \@implementation. This becomes necesssary because class extension can
3758 /// add ivars to a class in random order which will not be known until
3759 /// class's \@implementation is seen.
3761  ObjCInterfaceDecl *SID) {
3762  for (auto *Ivar : ID->ivars()) {
3763  if (Ivar->isInvalidDecl())
3764  continue;
3765  if (IdentifierInfo *II = Ivar->getIdentifier()) {
3766  ObjCIvarDecl* prevIvar = SID->lookupInstanceVariable(II);
3767  if (prevIvar) {
3768  Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
3769  Diag(prevIvar->getLocation(), diag::note_previous_declaration);
3770  Ivar->setInvalidDecl();
3771  }
3772  }
3773  }
3774 }
3775 
3776 /// Diagnose attempts to define ARC-__weak ivars when __weak is disabled.
3778  if (S.getLangOpts().ObjCWeak) return;
3779 
3780  for (auto ivar = ID->getClassInterface()->all_declared_ivar_begin();
3781  ivar; ivar = ivar->getNextIvar()) {
3782  if (ivar->isInvalidDecl()) continue;
3783  if (ivar->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
3784  if (S.getLangOpts().ObjCWeakRuntime) {
3785  S.Diag(ivar->getLocation(), diag::err_arc_weak_disabled);
3786  } else {
3787  S.Diag(ivar->getLocation(), diag::err_arc_weak_no_runtime);
3788  }
3789  }
3790  }
3791 }
3792 
3793 /// Diagnose attempts to use flexible array member with retainable object type.
3795  ObjCInterfaceDecl *ID) {
3796  if (!S.getLangOpts().ObjCAutoRefCount)
3797  return;
3798 
3799  for (auto ivar = ID->all_declared_ivar_begin(); ivar;
3800  ivar = ivar->getNextIvar()) {
3801  if (ivar->isInvalidDecl())
3802  continue;
3803  QualType IvarTy = ivar->getType();
3804  if (IvarTy->isIncompleteArrayType() &&
3806  IvarTy->isObjCLifetimeType()) {
3807  S.Diag(ivar->getLocation(), diag::err_flexible_array_arc_retainable);
3808  ivar->setInvalidDecl();
3809  }
3810  }
3811 }
3812 
3814  switch (CurContext->getDeclKind()) {
3815  case Decl::ObjCInterface:
3816  return Sema::OCK_Interface;
3817  case Decl::ObjCProtocol:
3818  return Sema::OCK_Protocol;
3819  case Decl::ObjCCategory:
3820  if (cast<ObjCCategoryDecl>(CurContext)->IsClassExtension())
3821  return Sema::OCK_ClassExtension;
3822  return Sema::OCK_Category;
3823  case Decl::ObjCImplementation:
3824  return Sema::OCK_Implementation;
3825  case Decl::ObjCCategoryImpl:
3827 
3828  default:
3829  return Sema::OCK_None;
3830  }
3831 }
3832 
3834  if (T->isIncompleteArrayType())
3835  return true;
3836  const auto *RecordTy = T->getAs<RecordType>();
3837  return (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember());
3838 }
3839 
3841  ObjCInterfaceDecl *IntfDecl = nullptr;
3842  ObjCInterfaceDecl::ivar_range Ivars = llvm::make_range(
3844  if ((IntfDecl = dyn_cast<ObjCInterfaceDecl>(OCD))) {
3845  Ivars = IntfDecl->ivars();
3846  } else if (auto *ImplDecl = dyn_cast<ObjCImplementationDecl>(OCD)) {
3847  IntfDecl = ImplDecl->getClassInterface();
3848  Ivars = ImplDecl->ivars();
3849  } else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(OCD)) {
3850  if (CategoryDecl->IsClassExtension()) {
3851  IntfDecl = CategoryDecl->getClassInterface();
3852  Ivars = CategoryDecl->ivars();
3853  }
3854  }
3855 
3856  // Check if variable sized ivar is in interface and visible to subclasses.
3857  if (!isa<ObjCInterfaceDecl>(OCD)) {
3858  for (auto ivar : Ivars) {
3859  if (!ivar->isInvalidDecl() && IsVariableSizedType(ivar->getType())) {
3860  S.Diag(ivar->getLocation(), diag::warn_variable_sized_ivar_visibility)
3861  << ivar->getDeclName() << ivar->getType();
3862  }
3863  }
3864  }
3865 
3866  // Subsequent checks require interface decl.
3867  if (!IntfDecl)
3868  return;
3869 
3870  // Check if variable sized ivar is followed by another ivar.
3871  for (ObjCIvarDecl *ivar = IntfDecl->all_declared_ivar_begin(); ivar;
3872  ivar = ivar->getNextIvar()) {
3873  if (ivar->isInvalidDecl() || !ivar->getNextIvar())
3874  continue;
3875  QualType IvarTy = ivar->getType();
3876  bool IsInvalidIvar = false;
3877  if (IvarTy->isIncompleteArrayType()) {
3878  S.Diag(ivar->getLocation(), diag::err_flexible_array_not_at_end)
3879  << ivar->getDeclName() << IvarTy
3880  << TTK_Class; // Use "class" for Obj-C.
3881  IsInvalidIvar = true;
3882  } else if (const RecordType *RecordTy = IvarTy->getAs<RecordType>()) {
3883  if (RecordTy->getDecl()->hasFlexibleArrayMember()) {
3884  S.Diag(ivar->getLocation(),
3885  diag::err_objc_variable_sized_type_not_at_end)
3886  << ivar->getDeclName() << IvarTy;
3887  IsInvalidIvar = true;
3888  }
3889  }
3890  if (IsInvalidIvar) {
3891  S.Diag(ivar->getNextIvar()->getLocation(),
3892  diag::note_next_ivar_declaration)
3893  << ivar->getNextIvar()->getSynthesize();
3894  ivar->setInvalidDecl();
3895  }
3896  }
3897 
3898  // Check if ObjC container adds ivars after variable sized ivar in superclass.
3899  // Perform the check only if OCD is the first container to declare ivars to
3900  // avoid multiple warnings for the same ivar.
3901  ObjCIvarDecl *FirstIvar =
3902  (Ivars.begin() == Ivars.end()) ? nullptr : *Ivars.begin();
3903  if (FirstIvar && (FirstIvar == IntfDecl->all_declared_ivar_begin())) {
3904  const ObjCInterfaceDecl *SuperClass = IntfDecl->getSuperClass();
3905  while (SuperClass && SuperClass->ivar_empty())
3906  SuperClass = SuperClass->getSuperClass();
3907  if (SuperClass) {
3908  auto IvarIter = SuperClass->ivar_begin();
3909  std::advance(IvarIter, SuperClass->ivar_size() - 1);
3910  const ObjCIvarDecl *LastIvar = *IvarIter;
3911  if (IsVariableSizedType(LastIvar->getType())) {
3912  S.Diag(FirstIvar->getLocation(),
3913  diag::warn_superclass_variable_sized_type_not_at_end)
3914  << FirstIvar->getDeclName() << LastIvar->getDeclName()
3915  << LastIvar->getType() << SuperClass->getDeclName();
3916  S.Diag(LastIvar->getLocation(), diag::note_entity_declared_at)
3917  << LastIvar->getDeclName();
3918  }
3919  }
3920  }
3921 }
3922 
3924  Sema &S, ObjCProtocolDecl *PDecl, ObjCCategoryDecl *CDecl);
3925 
3927  Sema &S, ObjCCategoryDecl *CDecl,
3928  const llvm::iterator_range<ObjCProtocolList::iterator> &Protocols) {
3929  for (auto *PI : Protocols)
3931 }
3932 
3934  Sema &S, ObjCProtocolDecl *PDecl, ObjCCategoryDecl *CDecl) {
3935  if (!PDecl->isThisDeclarationADefinition() && PDecl->getDefinition())
3936  PDecl = PDecl->getDefinition();
3937 
3938  llvm::SmallVector<const Decl *, 4> DirectMembers;
3939  const auto *IDecl = CDecl->getClassInterface();
3940  for (auto *MD : PDecl->methods()) {
3941  if (!MD->isPropertyAccessor()) {
3942  if (const auto *CMD =
3943  IDecl->getMethod(MD->getSelector(), MD->isInstanceMethod())) {
3944  if (CMD->isDirectMethod())
3945  DirectMembers.push_back(CMD);
3946  }
3947  }
3948  }
3949  for (auto *PD : PDecl->properties()) {
3950  if (const auto *CPD = IDecl->FindPropertyVisibleInPrimaryClass(
3951  PD->getIdentifier(),
3952  PD->isClassProperty()
3955  if (CPD->isDirectProperty())
3956  DirectMembers.push_back(CPD);
3957  }
3958  }
3959  if (!DirectMembers.empty()) {
3960  S.Diag(CDecl->getLocation(), diag::err_objc_direct_protocol_conformance)
3961  << CDecl->IsClassExtension() << CDecl << PDecl << IDecl;
3962  for (const auto *MD : DirectMembers)
3963  S.Diag(MD->getLocation(), diag::note_direct_member_here);
3964  return;
3965  }
3966 
3967  // Check on this protocols's referenced protocols, recursively.
3969  PDecl->protocols());
3970 }
3971 
3972 // Note: For class/category implementations, allMethods is always null.
3974  ArrayRef<DeclGroupPtrTy> allTUVars) {
3976  return nullptr;
3977 
3978  assert(AtEnd.isValid() && "Invalid location for '@end'");
3979 
3980  auto *OCD = cast<ObjCContainerDecl>(CurContext);
3981  Decl *ClassDecl = OCD;
3982 
3983  bool isInterfaceDeclKind =
3984  isa<ObjCInterfaceDecl>(ClassDecl) || isa<ObjCCategoryDecl>(ClassDecl)
3985  || isa<ObjCProtocolDecl>(ClassDecl);
3986  bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl);
3987 
3988  // Make synthesized accessor stub functions visible.
3989  // ActOnPropertyImplDecl() creates them as not visible in case
3990  // they are overridden by an explicit method that is encountered
3991  // later.
3992  if (auto *OID = dyn_cast<ObjCImplementationDecl>(CurContext)) {
3993  for (auto PropImpl : OID->property_impls()) {
3994  if (auto *Getter = PropImpl->getGetterMethodDecl())
3995  if (Getter->isSynthesizedAccessorStub())
3996  OID->addDecl(Getter);
3997  if (auto *Setter = PropImpl->getSetterMethodDecl())
3998  if (Setter->isSynthesizedAccessorStub())
3999  OID->addDecl(Setter);
4000  }
4001  }
4002 
4003  // FIXME: Remove these and use the ObjCContainerDecl/DeclContext.
4004  llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap;
4005  llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap;
4006 
4007  for (unsigned i = 0, e = allMethods.size(); i != e; i++ ) {
4008  ObjCMethodDecl *Method =
4009  cast_or_null<ObjCMethodDecl>(allMethods[i]);
4010 
4011  if (!Method) continue; // Already issued a diagnostic.
4012  if (Method->isInstanceMethod()) {
4013  /// Check for instance method of the same name with incompatible types
4014  const ObjCMethodDecl *&PrevMethod = InsMap[Method->getSelector()];
4015  bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
4016  : false;
4017  if ((isInterfaceDeclKind && PrevMethod && !match)
4018  || (checkIdenticalMethods && match)) {
4019  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
4020  << Method->getDeclName();
4021  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4022  Method->setInvalidDecl();
4023  } else {
4024  if (PrevMethod) {
4025  Method->setAsRedeclaration(PrevMethod);
4027  Method->getLocation()))
4028  Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
4029  << Method->getDeclName();
4030  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4031  }
4032  InsMap[Method->getSelector()] = Method;
4033  /// The following allows us to typecheck messages to "id".
4035  }
4036  } else {
4037  /// Check for class method of the same name with incompatible types
4038  const ObjCMethodDecl *&PrevMethod = ClsMap[Method->getSelector()];
4039  bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
4040  : false;
4041  if ((isInterfaceDeclKind && PrevMethod && !match)
4042  || (checkIdenticalMethods && match)) {
4043  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
4044  << Method->getDeclName();
4045  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4046  Method->setInvalidDecl();
4047  } else {
4048  if (PrevMethod) {
4049  Method->setAsRedeclaration(PrevMethod);
4051  Method->getLocation()))
4052  Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
4053  << Method->getDeclName();
4054  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4055  }
4056  ClsMap[Method->getSelector()] = Method;
4058  }
4059  }
4060  }
4061  if (isa<ObjCInterfaceDecl>(ClassDecl)) {
4062  // Nothing to do here.
4063  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
4064  // Categories are used to extend the class by declaring new methods.
4065  // By the same token, they are also used to add new properties. No
4066  // need to compare the added property to those in the class.
4067 
4068  if (C->IsClassExtension()) {
4069  ObjCInterfaceDecl *CCPrimary = C->getClassInterface();
4070  DiagnoseClassExtensionDupMethods(C, CCPrimary);
4071  }
4072 
4073  DiagnoseCategoryDirectMembersProtocolConformance(*this, C, C->protocols());
4074  }
4075  if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) {
4076  if (CDecl->getIdentifier())
4077  // ProcessPropertyDecl is responsible for diagnosing conflicts with any
4078  // user-defined setter/getter. It also synthesizes setter/getter methods
4079  // and adds them to the DeclContext and global method pools.
4080  for (auto *I : CDecl->properties())
4082  CDecl->setAtEndRange(AtEnd);
4083  }
4084  if (ObjCImplementationDecl *IC=dyn_cast<ObjCImplementationDecl>(ClassDecl)) {
4085  IC->setAtEndRange(AtEnd);
4086  if (ObjCInterfaceDecl* IDecl = IC->getClassInterface()) {
4087  // Any property declared in a class extension might have user
4088  // declared setter or getter in current class extension or one
4089  // of the other class extensions. Mark them as synthesized as
4090  // property will be synthesized when property with same name is
4091  // seen in the @implementation.
4092  for (const auto *Ext : IDecl->visible_extensions()) {
4093  for (const auto *Property : Ext->instance_properties()) {
4094  // Skip over properties declared @dynamic
4095  if (const ObjCPropertyImplDecl *PIDecl
4096  = IC->FindPropertyImplDecl(Property->getIdentifier(),
4097  Property->getQueryKind()))
4098  if (PIDecl->getPropertyImplementation()
4100  continue;
4101 
4102  for (const auto *Ext : IDecl->visible_extensions()) {
4103  if (ObjCMethodDecl *GetterMethod =
4104  Ext->getInstanceMethod(Property->getGetterName()))
4105  GetterMethod->setPropertyAccessor(true);
4106  if (!Property->isReadOnly())
4107  if (ObjCMethodDecl *SetterMethod
4108  = Ext->getInstanceMethod(Property->getSetterName()))
4109  SetterMethod->setPropertyAccessor(true);
4110  }
4111  }
4112  }
4113  ImplMethodsVsClassMethods(S, IC, IDecl);
4117  if (IDecl->hasDesignatedInitializers())
4119  DiagnoseWeakIvars(*this, IC);
4121 
4122  bool HasRootClassAttr = IDecl->hasAttr<ObjCRootClassAttr>();
4123  if (IDecl->getSuperClass() == nullptr) {
4124  // This class has no superclass, so check that it has been marked with
4125  // __attribute((objc_root_class)).
4126  if (!HasRootClassAttr) {
4127  SourceLocation DeclLoc(IDecl->getLocation());
4128  SourceLocation SuperClassLoc(getLocForEndOfToken(DeclLoc));
4129  Diag(DeclLoc, diag::warn_objc_root_class_missing)
4130  << IDecl->getIdentifier();
4131  // See if NSObject is in the current scope, and if it is, suggest
4132  // adding " : NSObject " to the class declaration.
4134  NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject),
4135  DeclLoc, LookupOrdinaryName);
4136  ObjCInterfaceDecl *NSObjectDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
4137  if (NSObjectDecl && NSObjectDecl->getDefinition()) {
4138  Diag(SuperClassLoc, diag::note_objc_needs_superclass)
4139  << FixItHint::CreateInsertion(SuperClassLoc, " : NSObject ");
4140  } else {
4141  Diag(SuperClassLoc, diag::note_objc_needs_superclass);
4142  }
4143  }
4144  } else if (HasRootClassAttr) {
4145  // Complain that only root classes may have this attribute.
4146  Diag(IDecl->getLocation(), diag::err_objc_root_class_subclass);
4147  }
4148 
4149  if (const ObjCInterfaceDecl *Super = IDecl->getSuperClass()) {
4150  // An interface can subclass another interface with a
4151  // objc_subclassing_restricted attribute when it has that attribute as
4152  // well (because of interfaces imported from Swift). Therefore we have
4153  // to check if we can subclass in the implementation as well.
4154  if (IDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
4155  Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
4156  Diag(IC->getLocation(), diag::err_restricted_superclass_mismatch);
4157  Diag(Super->getLocation(), diag::note_class_declared);
4158  }
4159  }
4160 
4161  if (IDecl->hasAttr<ObjCClassStubAttr>())
4162  Diag(IC->getLocation(), diag::err_implementation_of_class_stub);
4163 
4165  while (IDecl->getSuperClass()) {
4166  DiagnoseDuplicateIvars(IDecl, IDecl->getSuperClass());
4167  IDecl = IDecl->getSuperClass();
4168  }
4169  }
4170  }
4171  SetIvarInitializers(IC);
4172  } else if (ObjCCategoryImplDecl* CatImplClass =
4173  dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) {
4174  CatImplClass->setAtEndRange(AtEnd);
4175 
4176  // Find category interface decl and then check that all methods declared
4177  // in this interface are implemented in the category @implementation.
4178  if (ObjCInterfaceDecl* IDecl = CatImplClass->getClassInterface()) {
4179  if (ObjCCategoryDecl *Cat
4180  = IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier())) {
4181  ImplMethodsVsClassMethods(S, CatImplClass, Cat);
4182  }
4183  }
4184  } else if (const auto *IntfDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
4185  if (const ObjCInterfaceDecl *Super = IntfDecl->getSuperClass()) {
4186  if (!IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
4187  Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
4188  Diag(IntfDecl->getLocation(), diag::err_restricted_superclass_mismatch);
4189  Diag(Super->getLocation(), diag::note_class_declared);
4190  }
4191  }
4192 
4193  if (IntfDecl->hasAttr<ObjCClassStubAttr>() &&
4194  !IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>())
4195  Diag(IntfDecl->getLocation(), diag::err_class_stub_subclassing_mismatch);
4196  }
4197  DiagnoseVariableSizedIvars(*this, OCD);
4198  if (isInterfaceDeclKind) {
4199  // Reject invalid vardecls.
4200  for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
4201  DeclGroupRef DG = allTUVars[i].get();
4202  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
4203  if (VarDecl *VDecl = dyn_cast<VarDecl>(*I)) {
4204  if (!VDecl->hasExternalStorage())
4205  Diag(VDecl->getLocation(), diag::err_objc_var_decl_inclass);
4206  }
4207  }
4208  }
4210 
4211  for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
4212  DeclGroupRef DG = allTUVars[i].get();
4213  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
4214  (*I)->setTopLevelDeclInObjCContainer();
4216  }
4217 
4218  ActOnDocumentableDecl(ClassDecl);
4219  return ClassDecl;
4220 }
4221 
4222 /// CvtQTToAstBitMask - utility routine to produce an AST bitmask for
4223 /// objective-c's type qualifier from the parser version of the same info.
4226  return (Decl::ObjCDeclQualifier) (unsigned) PQTVal;
4227 }
4228 
4229 /// Check whether the declared result type of the given Objective-C
4230 /// method declaration is compatible with the method's class.
4231 ///
4234  ObjCInterfaceDecl *CurrentClass) {
4235  QualType ResultType = Method->getReturnType();
4236 
4237  // If an Objective-C method inherits its related result type, then its
4238  // declared result type must be compatible with its own class type. The
4239  // declared result type is compatible if:
4240  if (const ObjCObjectPointerType *ResultObjectType
4241  = ResultType->getAs<ObjCObjectPointerType>()) {
4242  // - it is id or qualified id, or
4243  if (ResultObjectType->isObjCIdType() ||
4244  ResultObjectType->isObjCQualifiedIdType())
4245  return Sema::RTC_Compatible;
4246 
4247  if (CurrentClass) {
4248  if (ObjCInterfaceDecl *ResultClass
4249  = ResultObjectType->getInterfaceDecl()) {
4250  // - it is the same as the method's class type, or
4251  if (declaresSameEntity(CurrentClass, ResultClass))
4252  return Sema::RTC_Compatible;
4253 
4254  // - it is a superclass of the method's class type
4255  if (ResultClass->isSuperClassOf(CurrentClass))
4256  return Sema::RTC_Compatible;
4257  }
4258  } else {
4259  // Any Objective-C pointer type might be acceptable for a protocol
4260  // method; we just don't know.
4261  return Sema::RTC_Unknown;
4262  }
4263  }
4264 
4265  return Sema::RTC_Incompatible;
4266 }
4267 
4268 namespace {
4269 /// A helper class for searching for methods which a particular method
4270 /// overrides.
4271 class OverrideSearch {
4272 public:
4273  const ObjCMethodDecl *Method;
4275  bool Recursive;
4276 
4277 public:
4278  OverrideSearch(Sema &S, const ObjCMethodDecl *method) : Method(method) {
4279  Selector selector = method->getSelector();
4280 
4281  // Bypass this search if we've never seen an instance/class method
4282  // with this selector before.
4284  if (it == S.MethodPool.end()) {
4285  if (!S.getExternalSource()) return;
4286  S.ReadMethodPool(selector);
4287 
4288  it = S.MethodPool.find(selector);
4289  if (it == S.MethodPool.end())
4290  return;
4291  }
4292  const ObjCMethodList &list =
4293  method->isInstanceMethod() ? it->second.first : it->second.second;
4294  if (!list.getMethod()) return;
4295 
4296  const ObjCContainerDecl *container
4297  = cast<ObjCContainerDecl>(method->getDeclContext());
4298 
4299  // Prevent the search from reaching this container again. This is
4300  // important with categories, which override methods from the
4301  // interface and each other.
4302  if (const ObjCCategoryDecl *Category =
4303  dyn_cast<ObjCCategoryDecl>(container)) {
4304  searchFromContainer(container);
4305  if (const ObjCInterfaceDecl *Interface = Category->getClassInterface())
4306  searchFromContainer(Interface);
4307  } else {
4308  searchFromContainer(container);
4309  }
4310  }
4311 
4312  typedef decltype(Overridden)::iterator iterator;
4313  iterator begin() const { return Overridden.begin(); }
4314  iterator end() const { return Overridden.end(); }
4315 
4316 private:
4317  void searchFromContainer(const ObjCContainerDecl *container) {
4318  if (container->isInvalidDecl()) return;
4319 
4320  switch (container->getDeclKind()) {
4321 #define OBJCCONTAINER(type, base) \
4322  case Decl::type: \
4323  searchFrom(cast<type##Decl>(container)); \
4324  break;
4325 #define ABSTRACT_DECL(expansion)
4326 #define DECL(type, base) \
4327  case Decl::type:
4328 #include "clang/AST/DeclNodes.inc"
4329  llvm_unreachable("not an ObjC container!");
4330  }
4331  }
4332 
4333  void searchFrom(const ObjCProtocolDecl *protocol) {
4334  if (!protocol->hasDefinition())
4335  return;
4336 
4337  // A method in a protocol declaration overrides declarations from
4338  // referenced ("parent") protocols.
4339  search(protocol->getReferencedProtocols());
4340  }
4341 
4342  void searchFrom(const ObjCCategoryDecl *category) {
4343  // A method in a category declaration overrides declarations from
4344  // the main class and from protocols the category references.
4345  // The main class is handled in the constructor.
4346  search(category->getReferencedProtocols());
4347  }
4348 
4349  void searchFrom(const ObjCCategoryImplDecl *impl) {
4350  // A method in a category definition that has a category
4351  // declaration overrides declarations from the category
4352  // declaration.
4353  if (ObjCCategoryDecl *category = impl->getCategoryDecl()) {
4354  search(category);
4355  if (ObjCInterfaceDecl *Interface = category->getClassInterface())
4356  search(Interface);
4357 
4358  // Otherwise it overrides declarations from the class.
4359  } else if (const auto *Interface = impl->getClassInterface()) {
4360  search(Interface);
4361  }
4362  }
4363 
4364  void searchFrom(const ObjCInterfaceDecl *iface) {
4365  // A method in a class declaration overrides declarations from
4366  if (!iface->hasDefinition())
4367  return;
4368 
4369  // - categories,
4370  for (auto *Cat : iface->known_categories())
4371  search(Cat);
4372 
4373  // - the super class, and
4374  if (ObjCInterfaceDecl *super = iface->getSuperClass())
4375  search(super);
4376 
4377  // - any referenced protocols.
4378  search(iface->getReferencedProtocols());
4379  }
4380 
4381  void searchFrom(const ObjCImplementationDecl *impl) {
4382  // A method in a class implementation overrides declarations from
4383  // the class interface.
4384  if (const auto *Interface = impl->getClassInterface())
4385  search(Interface);
4386  }
4387 
4388  void search(const ObjCProtocolList &protocols) {
4389  for (const auto *Proto : protocols)
4390  search(Proto);
4391  }
4392 
4393  void search(const ObjCContainerDecl *container) {
4394  // Check for a method in this container which matches this selector.
4395  ObjCMethodDecl *meth = container->getMethod(Method->getSelector(),
4396  Method->isInstanceMethod(),
4397  /*AllowHidden=*/true);
4398 
4399  // If we find one, record it and bail out.
4400  if (meth) {
4401  Overridden.insert(meth);
4402  return;
4403  }
4404 
4405  // Otherwise, search for methods that a hypothetical method here
4406  // would have overridden.
4407 
4408  // Note that we're now in a recursive case.
4409  Recursive = true;
4410 
4411  searchFromContainer(container);
4412  }
4413 };
4414 } // end anonymous namespace
4415 
4417  ObjCMethodDecl *overridden) {
4418  if (overridden->isDirectMethod()) {
4419  const auto *attr = overridden->getAttr<ObjCDirectAttr>();
4420  Diag(method->getLocation(), diag::err_objc_override_direct_method);
4421  Diag(attr->getLocation(), diag::note_previous_declaration);
4422  } else if (method->isDirectMethod()) {
4423  const auto *attr = method->getAttr<ObjCDirectAttr>();
4424  Diag(attr->getLocation(), diag::err_objc_direct_on_override)
4425  << isa<ObjCProtocolDecl>(overridden->getDeclContext());
4426  Diag(overridden->getLocation(), diag::note_previous_declaration);
4427  }
4428 }
4429 
4431  ObjCInterfaceDecl *CurrentClass,
4433  if (!ObjCMethod)
4434  return;
4435  // Search for overridden methods and merge information down from them.
4436  OverrideSearch overrides(*this, ObjCMethod);
4437  // Keep track if the method overrides any method in the class's base classes,
4438  // its protocols, or its categories' protocols; we will keep that info
4439  // in the ObjCMethodDecl.
4440  // For this info, a method in an implementation is not considered as
4441  // overriding the same method in the interface or its categories.
4442  bool hasOverriddenMethodsInBaseOrProtocol = false;
4443  for (ObjCMethodDecl *overridden : overrides) {
4444  if (!hasOverriddenMethodsInBaseOrProtocol) {
4445  if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
4446  CurrentClass != overridden->getClassInterface() ||
4447  overridden->isOverriding()) {
4448  CheckObjCMethodDirectOverrides(ObjCMethod, overridden);
4449  hasOverriddenMethodsInBaseOrProtocol = true;
4450  } else if (isa<ObjCImplDecl>(ObjCMethod->getDeclContext())) {
4451  // OverrideSearch will return as "overridden" the same method in the
4452  // interface. For hasOverriddenMethodsInBaseOrProtocol, we need to
4453  // check whether a category of a base class introduced a method with the
4454  // same selector, after the interface method declaration.
4455  // To avoid unnecessary lookups in the majority of cases, we use the
4456  // extra info bits in GlobalMethodPool to check whether there were any
4457  // category methods with this selector.
4459  MethodPool.find(ObjCMethod->getSelector());
4460  if (It != MethodPool.end()) {
4461  ObjCMethodList &List =
4462  ObjCMethod->isInstanceMethod()? It->second.first: It->second.second;
4463  unsigned CategCount = List.getBits();
4464  if (CategCount > 0) {
4465  // If the method is in a category we'll do lookup if there were at
4466  // least 2 category methods recorded, otherwise only one will do.
4467  if (CategCount > 1 ||
4468  !isa<ObjCCategoryImplDecl>(overridden->getDeclContext())) {
4469  OverrideSearch overrides(*this, overridden);
4470  for (ObjCMethodDecl *SuperOverridden : overrides) {
4471  if (isa<ObjCProtocolDecl>(SuperOverridden->getDeclContext()) ||
4472  CurrentClass != SuperOverridden->getClassInterface()) {
4473  CheckObjCMethodDirectOverrides(ObjCMethod, SuperOverridden);
4474  hasOverriddenMethodsInBaseOrProtocol = true;
4475  overridden->setOverriding(true);
4476  break;
4477  }
4478  }
4479  }
4480  }
4481  }
4482  }
4483  }
4484 
4485  // Propagate down the 'related result type' bit from overridden methods.
4486  if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType())
4487  ObjCMethod->setRelatedResultType();
4488 
4489  // Then merge the declarations.
4490  mergeObjCMethodDecls(ObjCMethod, overridden);
4491 
4492  if (ObjCMethod->isImplicit() && overridden->isImplicit())
4493  continue; // Conflicting properties are detected elsewhere.
4494 
4495  // Check for overriding methods
4496  if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) ||
4497  isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
4498  CheckConflictingOverridingMethod(ObjCMethod, overridden,
4499  isa<ObjCProtocolDecl>(overridden->getDeclContext()));
4500 
4501  if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
4502  isa<ObjCInterfaceDecl>(overridden->getDeclContext()) &&
4503  !overridden->isImplicit() /* not meant for properties */) {
4504  ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
4505  E = ObjCMethod->param_end();
4506  ObjCMethodDecl::param_iterator PrevI = overridden->param_begin(),
4507  PrevE = overridden->param_end();
4508  for (; ParamI != E && PrevI != PrevE; ++ParamI, ++PrevI) {
4509  assert(PrevI != overridden->param_end() && "Param mismatch");
4510  QualType T1 = Context.getCanonicalType((*ParamI)->getType());
4511  QualType T2 = Context.getCanonicalType((*PrevI)->getType());
4512  // If type of argument of method in this class does not match its
4513  // respective argument type in the super class method, issue warning;
4514  if (!Context.typesAreCompatible(T1, T2)) {
4515  Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
4516  << T1 << T2;
4517  Diag(overridden->getLocation(), diag::note_previous_declaration);
4518  break;
4519  }
4520  }
4521  }
4522  }
4523 
4524  ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol);
4525 }
4526 
4527 /// Merge type nullability from for a redeclaration of the same entity,
4528 /// producing the updated type of the redeclared entity.
4530  QualType type,
4531  bool usesCSKeyword,
4532  SourceLocation prevLoc,
4533  QualType prevType,
4534  bool prevUsesCSKeyword) {
4535  // Determine the nullability of both types.
4536  auto nullability = type->getNullability(S.Context);
4537  auto prevNullability = prevType->getNullability(S.Context);
4538 
4539  // Easy case: both have nullability.
4540  if (nullability.has_value() == prevNullability.has_value()) {
4541  // Neither has nullability; continue.
4542  if (!nullability)
4543  return type;
4544 
4545  // The nullabilities are equivalent; do nothing.
4546  if (*nullability == *prevNullability)
4547  return type;
4548 
4549  // Complain about mismatched nullability.
4550  S.Diag(loc, diag::err_nullability_conflicting)
4551  << DiagNullabilityKind(*nullability, usesCSKeyword)
4552  << DiagNullabilityKind(*prevNullability, prevUsesCSKeyword);
4553  return type;
4554  }
4555 
4556  // If it's the redeclaration that has nullability, don't change anything.
4557  if (nullability)
4558  return type;
4559 
4560  // Otherwise, provide the result with the same nullability.
4561  return S.Context.getAttributedType(
4562  AttributedType::getNullabilityAttrKind(*prevNullability),
4563  type, type);
4564 }
4565 
4566 /// Merge information from the declaration of a method in the \@interface
4567 /// (or a category/extension) into the corresponding method in the
4568 /// @implementation (for a class or category).
4570  ObjCMethodDecl *method,
4571  ObjCMethodDecl *prevMethod) {
4572  // Merge the objc_requires_super attribute.
4573  if (prevMethod->hasAttr<ObjCRequiresSuperAttr>() &&
4574  !method->hasAttr<ObjCRequiresSuperAttr>()) {
4575  // merge the attribute into implementation.
4576  method->addAttr(
4577  ObjCRequiresSuperAttr::CreateImplicit(S.Context,
4578  method->getLocation()));
4579  }
4580 
4581  // Merge nullability of the result type.
4582  QualType newReturnType
4584  S, method->getReturnTypeSourceRange().getBegin(),
4585  method->getReturnType(),
4587  prevMethod->getReturnTypeSourceRange().getBegin(),
4588  prevMethod->getReturnType(),
4590  method->setReturnType(newReturnType);
4591 
4592  // Handle each of the parameters.
4593  unsigned numParams = method->param_size();
4594  unsigned numPrevParams = prevMethod->param_size();
4595  for (unsigned i = 0, n = std::min(numParams, numPrevParams); i != n; ++i) {
4596  ParmVarDecl *param = method->param_begin()[i];
4597  ParmVarDecl *prevParam = prevMethod->param_begin()[i];
4598 
4599  // Merge nullability.
4600  QualType newParamType
4602  S, param->getLocation(), param->getType(),
4604  prevParam->getLocation(), prevParam->getType(),
4606  param->setType(newParamType);
4607  }
4608 }
4609 
4610 /// Verify that the method parameters/return value have types that are supported
4611 /// by the x86 target.
4613  const ObjCMethodDecl *Method) {
4614  assert(SemaRef.getASTContext().getTargetInfo().getTriple().getArch() ==
4615  llvm::Triple::x86 &&
4616  "x86-specific check invoked for a different target");
4617  SourceLocation Loc;
4618  QualType T;
4619  for (const ParmVarDecl *P : Method->parameters()) {
4620  if (P->getType()->isVectorType()) {
4621  Loc = P->getBeginLoc();
4622  T = P->getType();
4623  break;
4624  }
4625  }
4626  if (Loc.isInvalid()) {
4627  if (Method->getReturnType()->isVectorType()) {
4628  Loc = Method->getReturnTypeSourceRange().getBegin();
4629  T = Method->getReturnType();
4630  } else
4631  return;
4632  }
4633 
4634  // Vector parameters/return values are not supported by objc_msgSend on x86 in
4635  // iOS < 9 and macOS < 10.11.
4636  const auto &Triple = SemaRef.getASTContext().getTargetInfo().getTriple();
4637  VersionTuple AcceptedInVersion;
4638  if (Triple.getOS() == llvm::Triple::IOS)
4639  AcceptedInVersion = VersionTuple(/*Major=*/9);
4640  else if (Triple.isMacOSX())
4641  AcceptedInVersion = VersionTuple(/*Major=*/10, /*Minor=*/11);
4642  else
4643  return;
4645  AcceptedInVersion)
4646  return;
4647  SemaRef.Diag(Loc, diag::err_objc_method_unsupported_param_ret_type)
4648  << T << (Method->getReturnType()->isVectorType() ? /*return value*/ 1
4649  : /*parameter*/ 0)
4650  << (Triple.isMacOSX() ? "macOS 10.11" : "iOS 9");
4651 }
4652 
4653 static void mergeObjCDirectMembers(Sema &S, Decl *CD, ObjCMethodDecl *Method) {
4654  if (!Method->isDirectMethod() && !Method->hasAttr<UnavailableAttr>() &&
4655  CD->hasAttr<ObjCDirectMembersAttr>()) {
4656  Method->addAttr(
4657  ObjCDirectAttr::CreateImplicit(S.Context, Method->getLocation()));
4658  }
4659 }
4660 
4662  ObjCMethodDecl *Method,
4663  ObjCImplDecl *ImpDecl = nullptr) {
4664  auto Sel = Method->getSelector();
4665  bool isInstance = Method->isInstanceMethod();
4666  bool diagnosed = false;
4667 
4668  auto diagClash = [&](const ObjCMethodDecl *IMD) {
4669  if (diagnosed || IMD->isImplicit())
4670  return;
4671  if (Method->isDirectMethod() || IMD->isDirectMethod()) {
4672  S.Diag(Method->getLocation(), diag::err_objc_direct_duplicate_decl)
4673  << Method->isDirectMethod() << /* method */ 0 << IMD->isDirectMethod()
4674  << Method->getDeclName();
4675  S.Diag(IMD->getLocation(), diag::note_previous_declaration);
4676  diagnosed = true;
4677  }
4678  };
4679 
4680  // Look for any other declaration of this method anywhere we can see in this
4681  // compilation unit.
4682  //
4683  // We do not use IDecl->lookupMethod() because we have specific needs:
4684  //
4685  // - we absolutely do not need to walk protocols, because
4686  // diag::err_objc_direct_on_protocol has already been emitted
4687  // during parsing if there's a conflict,
4688  //
4689  // - when we do not find a match in a given @interface container,
4690  // we need to attempt looking it up in the @implementation block if the
4691  // translation unit sees it to find more clashes.
4692 
4693  if (auto *IMD = IDecl->getMethod(Sel, isInstance))
4694  diagClash(IMD);
4695  else if (auto *Impl = IDecl->getImplementation())
4696  if (Impl != ImpDecl)
4697  if (auto *IMD = IDecl->getImplementation()->getMethod(Sel, isInstance))
4698  diagClash(IMD);
4699 
4700  for (const auto *Cat : IDecl->visible_categories())
4701  if (auto *IMD = Cat->getMethod(Sel, isInstance))
4702  diagClash(IMD);
4703  else if (auto CatImpl = Cat->getImplementation())
4704  if (CatImpl != ImpDecl)
4705  if (auto *IMD = Cat->getMethod(Sel, isInstance))
4706  diagClash(IMD);
4707 }
4708 
4710  Scope *S, SourceLocation MethodLoc, SourceLocation EndLoc,
4711  tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
4712  ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
4713  // optional arguments. The number of types/arguments is obtained
4714  // from the Sel.getNumArgs().
4715  ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo,
4716  unsigned CNumArgs, // c-style args
4717  const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodDeclKind,
4718  bool isVariadic, bool MethodDefinition) {
4719  // Make sure we can establish a context for the method.
4720  if (!CurContext->isObjCContainer()) {
4721  Diag(MethodLoc, diag::err_missing_method_context);
4722  return nullptr;
4723  }
4724 
4725  Decl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
4726  QualType resultDeclType;
4727 
4728  bool HasRelatedResultType = false;
4729  TypeSourceInfo *ReturnTInfo = nullptr;
4730  if (ReturnType) {
4731  resultDeclType = GetTypeFromParser(ReturnType, &ReturnTInfo);
4732 
4733  if (CheckFunctionReturnType(resultDeclType, MethodLoc))
4734  return nullptr;
4735 
4736  QualType bareResultType = resultDeclType;
4737  (void)AttributedType::stripOuterNullability(bareResultType);
4738  HasRelatedResultType = (bareResultType == Context.getObjCInstanceType());
4739  } else { // get the type for "id".
4740  resultDeclType = Context.getObjCIdType();
4741  Diag(MethodLoc, diag::warn_missing_method_return_type)
4742  << FixItHint::CreateInsertion(SelectorLocs.front(), "(id)");
4743  }
4744 
4745  ObjCMethodDecl *ObjCMethod = ObjCMethodDecl::Create(
4746  Context, MethodLoc, EndLoc, Sel, resultDeclType, ReturnTInfo, CurContext,
4747  MethodType == tok::minus, isVariadic,
4748  /*isPropertyAccessor=*/false, /*isSynthesizedAccessorStub=*/false,
4749  /*isImplicitlyDeclared=*/false, /*isDefined=*/false,
4750  MethodDeclKind == tok::objc_optional ? ObjCMethodDecl::Optional
4752  HasRelatedResultType);
4753 
4755 
4756  for (unsigned i = 0, e = Sel.getNumArgs(); i != e; ++i) {
4757  QualType ArgType;
4758  TypeSourceInfo *DI;
4759 
4760  if (!ArgInfo[i].Type) {
4761  ArgType = Context.getObjCIdType();
4762  DI = nullptr;
4763  } else {
4764  ArgType = GetTypeFromParser(ArgInfo[i].Type, &DI);
4765  }
4766 
4767  LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc,
4769  LookupName(R, S);
4770  if (R.isSingleResult()) {
4771  NamedDecl *PrevDecl = R.getFoundDecl();
4772  if (S->isDeclScope(PrevDecl)) {
4773  Diag(ArgInfo[i].NameLoc,
4774  (MethodDefinition ? diag::warn_method_param_redefinition
4775  : diag::warn_method_param_declaration))
4776  << ArgInfo[i].Name;
4777  Diag(PrevDecl->getLocation(),
4778  diag::note_previous_declaration);
4779  }
4780  }
4781 
4782  SourceLocation StartLoc = DI
4783  ? DI->getTypeLoc().getBeginLoc()
4784  : ArgInfo[i].NameLoc;
4785 
4786  ParmVarDecl* Param = CheckParameter(ObjCMethod, StartLoc,
4787  ArgInfo[i].NameLoc, ArgInfo[i].Name,
4788  ArgType, DI, SC_None);
4789 
4790  Param->setObjCMethodScopeInfo(i);
4791 
4792  Param->setObjCDeclQualifier(
4793  CvtQTToAstBitMask(ArgInfo[i].DeclSpec.getObjCDeclQualifier()));
4794 
4795  // Apply the attributes to the parameter.
4796  ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs);
4797  AddPragmaAttributes(TUScope, Param);
4798 
4799  if (Param->hasAttr<BlocksAttr>()) {
4800  Diag(Param->getLocation(), diag::err_block_on_nonlocal);
4801  Param->setInvalidDecl();
4802  }
4803  S->AddDecl(Param);
4804  IdResolver.AddDecl(Param);
4805 
4806  Params.push_back(Param);
4807  }
4808 
4809  for (unsigned i = 0, e = CNumArgs; i != e; ++i) {
4810  ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param);
4811  QualType ArgType = Param->getType();
4812  if (ArgType.isNull())
4813  ArgType = Context.getObjCIdType();
4814  else
4815  // Perform the default array/function conversions (C99 6.7.5.3p[7,8]).
4816  ArgType = Context.getAdjustedParameterType(ArgType);
4817 
4818  Param->setDeclContext(ObjCMethod);
4819  Params.push_back(Param);
4820  }
4821 
4822  ObjCMethod->setMethodParams(Context, Params, SelectorLocs);
4823  ObjCMethod->setObjCDeclQualifier(
4825 
4826  ProcessDeclAttributeList(TUScope, ObjCMethod, AttrList);
4827  AddPragmaAttributes(TUScope, ObjCMethod);
4828 
4829  // Add the method now.
4830  const ObjCMethodDecl *PrevMethod = nullptr;
4831  if (ObjCImplDecl *ImpDecl = dyn_cast<ObjCImplDecl>(ClassDecl)) {
4832  if (MethodType == tok::minus) {
4833  PrevMethod = ImpDecl->getInstanceMethod(Sel);
4834  ImpDecl->addInstanceMethod(ObjCMethod);
4835  } else {
4836  PrevMethod = ImpDecl->getClassMethod(Sel);
4837  ImpDecl->addClassMethod(ObjCMethod);
4838  }
4839 
4840  // If this method overrides a previous @synthesize declaration,
4841  // register it with the property. Linear search through all
4842  // properties here, because the autosynthesized stub hasn't been
4843  // made visible yet, so it can be overridden by a later
4844  // user-specified implementation.
4845  for (ObjCPropertyImplDecl *PropertyImpl : ImpDecl->property_impls()) {
4846  if (auto *Setter = PropertyImpl->getSetterMethodDecl())
4847  if (Setter->getSelector() == Sel &&
4848  Setter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
4849  assert(Setter->isSynthesizedAccessorStub() && "autosynth stub expected");
4850  PropertyImpl->setSetterMethodDecl(ObjCMethod);
4851  }
4852  if (auto *Getter = PropertyImpl->getGetterMethodDecl())
4853  if (Getter->getSelector() == Sel &&
4854  Getter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
4855  assert(Getter->isSynthesizedAccessorStub() && "autosynth stub expected");
4856  PropertyImpl->setGetterMethodDecl(ObjCMethod);
4857  break;
4858  }
4859  }
4860 
4861  // A method is either tagged direct explicitly, or inherits it from its
4862  // canonical declaration.
4863  //
4864  // We have to do the merge upfront and not in mergeInterfaceMethodToImpl()
4865  // because IDecl->lookupMethod() returns more possible matches than just
4866  // the canonical declaration.
4867  if (!ObjCMethod->isDirectMethod()) {
4868  const ObjCMethodDecl *CanonicalMD = ObjCMethod->getCanonicalDecl();
4869  if (CanonicalMD->isDirectMethod()) {
4870  const auto *attr = CanonicalMD->getAttr<ObjCDirectAttr>();
4871  ObjCMethod->addAttr(
4872  ObjCDirectAttr::CreateImplicit(Context, attr->getLocation()));
4873  }
4874  }
4875 
4876  // Merge information from the @interface declaration into the
4877  // @implementation.
4878  if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface()) {
4879  if (auto *IMD = IDecl->lookupMethod(ObjCMethod->getSelector(),
4880  ObjCMethod->isInstanceMethod())) {
4881  mergeInterfaceMethodToImpl(*this, ObjCMethod, IMD);
4882 
4883  // The Idecl->lookupMethod() above will find declarations for ObjCMethod
4884  // in one of these places:
4885  //
4886  // (1) the canonical declaration in an @interface container paired
4887  // with the ImplDecl,
4888  // (2) non canonical declarations in @interface not paired with the
4889  // ImplDecl for the same Class,
4890  // (3) any superclass container.
4891  //
4892  // Direct methods only allow for canonical declarations in the matching
4893  // container (case 1).
4894  //
4895  // Direct methods overriding a superclass declaration (case 3) is
4896  // handled during overrides checks in CheckObjCMethodOverrides().
4897  //
4898  // We deal with same-class container mismatches (Case 2) here.
4899  if (IDecl == IMD->getClassInterface()) {
4900  auto diagContainerMismatch = [&] {
4901  int decl = 0, impl = 0;
4902 
4903  if (auto *Cat = dyn_cast<ObjCCategoryDecl>(IMD->getDeclContext()))
4904  decl = Cat->IsClassExtension() ? 1 : 2;
4905 
4906  if (isa<ObjCCategoryImplDecl>(ImpDecl))
4907  impl = 1 + (decl != 0);
4908 
4909  Diag(ObjCMethod->getLocation(),
4910  diag::err_objc_direct_impl_decl_mismatch)
4911  << decl << impl;
4912  Diag(IMD->getLocation(), diag::note_previous_declaration);
4913  };
4914 
4915  if (ObjCMethod->isDirectMethod()) {
4916  const auto *attr = ObjCMethod->getAttr<ObjCDirectAttr>();
4917  if (ObjCMethod->getCanonicalDecl() != IMD) {
4918  diagContainerMismatch();
4919  } else if (!IMD->isDirectMethod()) {
4920  Diag(attr->getLocation(), diag::err_objc_direct_missing_on_decl);
4921  Diag(IMD->getLocation(), diag::note_previous_declaration);
4922  }
4923  } else if (IMD->isDirectMethod()) {
4924  const auto *attr = IMD->getAttr<ObjCDirectAttr>();
4925  if (ObjCMethod->getCanonicalDecl() != IMD) {
4926  diagContainerMismatch();
4927  } else {
4928  ObjCMethod->addAttr(
4929  ObjCDirectAttr::CreateImplicit(Context, attr->getLocation()));
4930  }
4931  }
4932  }
4933 
4934  // Warn about defining -dealloc in a category.
4935  if (isa<ObjCCategoryImplDecl>(ImpDecl) && IMD->isOverriding() &&
4936  ObjCMethod->getSelector().getMethodFamily() == OMF_dealloc) {
4937  Diag(ObjCMethod->getLocation(), diag::warn_dealloc_in_category)
4938  << ObjCMethod->getDeclName();
4939  }
4940  } else {
4941  mergeObjCDirectMembers(*this, ClassDecl, ObjCMethod);
4942  checkObjCDirectMethodClashes(*this, IDecl, ObjCMethod, ImpDecl);
4943  }
4944 
4945  // Warn if a method declared in a protocol to which a category or
4946  // extension conforms is non-escaping and the implementation's method is
4947  // escaping.
4948  for (auto *C : IDecl->visible_categories())
4949  for (auto &P : C->protocols())
4950  if (auto *IMD = P->lookupMethod(ObjCMethod->getSelector(),
4951  ObjCMethod->isInstanceMethod())) {
4952  assert(ObjCMethod->parameters().size() ==
4953  IMD->parameters().size() &&
4954  "Methods have different number of parameters");
4955  auto OI = IMD->param_begin(), OE = IMD->param_end();
4956  auto NI = ObjCMethod->param_begin();
4957  for (; OI != OE; ++OI, ++NI)
4958  diagnoseNoescape(*NI, *OI, C, P, *this);
4959  }
4960  }
4961  } else {
4962  if (!isa<ObjCProtocolDecl>(ClassDecl)) {
4963  mergeObjCDirectMembers(*this, ClassDecl, ObjCMethod);
4964 
4965  ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
4966  if (!IDecl)
4967  IDecl = cast<ObjCCategoryDecl>(ClassDecl)->getClassInterface();
4968  // For valid code, we should always know the primary interface
4969  // declaration by now, however for invalid code we'll keep parsing
4970  // but we won't find the primary interface and IDecl will be nil.
4971  if (IDecl)
4972  checkObjCDirectMethodClashes(*this, IDecl, ObjCMethod);
4973  }
4974 
4975  cast<DeclContext>(ClassDecl)->addDecl(ObjCMethod);
4976  }
4977 
4978  if (PrevMethod) {
4979  // You can never have two method definitions with the same name.
4980  Diag(ObjCMethod->getLocation(), diag::err_duplicate_method_decl)
4981  << ObjCMethod->getDeclName();
4982  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4983  ObjCMethod->setInvalidDecl();
4984  return ObjCMethod;
4985  }
4986 
4987  // If this Objective-C method does not have a related result type, but we
4988  // are allowed to infer related result types, try to do so based on the
4989  // method family.
4990  ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
4991  if (!CurrentClass) {
4992  if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl))
4993  CurrentClass = Cat->getClassInterface();
4994  else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(ClassDecl))
4995  CurrentClass = Impl->getClassInterface();
4996  else if (ObjCCategoryImplDecl *CatImpl
4997  = dyn_cast<ObjCCategoryImplDecl>(ClassDecl))
4998  CurrentClass = CatImpl->getClassInterface();
4999  }
5000 
5002  = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
5003 
5004  CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC);
5005 
5006  bool ARCError = false;
5007  if (getLangOpts().ObjCAutoRefCount)
5008  ARCError = CheckARCMethodDecl(ObjCMethod);
5009 
5010  // Infer the related result type when possible.
5011  if (!ARCError && RTC == Sema::RTC_Compatible &&
5012  !ObjCMethod->hasRelatedResultType() &&
5013  LangOpts.ObjCInferRelatedResultType) {
5014  bool InferRelatedResultType = false;
5015  switch (ObjCMethod->getMethodFamily()) {
5016  case OMF_None:
5017  case OMF_copy:
5018  case OMF_dealloc:
5019  case OMF_finalize:
5020  case OMF_mutableCopy:
5021  case OMF_release:
5022  case OMF_retainCount:
5023  case OMF_initialize:
5024  case OMF_performSelector:
5025  break;
5026 
5027  case OMF_alloc:
5028  case OMF_new:
5029  InferRelatedResultType = ObjCMethod->isClassMethod();
5030  break;
5031 
5032  case OMF_init:
5033  case OMF_autorelease:
5034  case OMF_retain:
5035  case OMF_self:
5036  InferRelatedResultType = ObjCMethod->isInstanceMethod();
5037  break;
5038  }
5039 
5040  if (InferRelatedResultType &&
5041  !ObjCMethod->getReturnType()->isObjCIndependentClassType())
5042  ObjCMethod->setRelatedResultType();
5043  }
5044 
5045  if (MethodDefinition &&
5046  Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
5047  checkObjCMethodX86VectorTypes(*this, ObjCMethod);
5048 
5049  // + load method cannot have availability attributes. It get called on
5050  // startup, so it has to have the availability of the deployment target.
5051  if (const auto *attr = ObjCMethod->getAttr<AvailabilityAttr>()) {
5052  if (ObjCMethod->isClassMethod() &&
5053  ObjCMethod->getSelector().getAsString() == "load") {
5054  Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
5055  << 0;
5056  ObjCMethod->dropAttr<AvailabilityAttr>();
5057  }
5058  }
5059 
5060  // Insert the invisible arguments, self and _cmd!
5061  ObjCMethod->createImplicitParams(Context, ObjCMethod->getClassInterface());
5062 
5063  ActOnDocumentableDecl(ObjCMethod);
5064 
5065  return ObjCMethod;
5066 }
5067 
5069  // Following is also an error. But it is caused by a missing @end
5070  // and diagnostic is issued elsewhere.
5071  if (isa<ObjCContainerDecl>(CurContext->getRedeclContext()))
5072  return false;
5073 
5074  // If we switched context to translation unit while we are still lexically in
5075  // an objc container, it means the parser missed emitting an error.
5076  if (isa<TranslationUnitDecl>(getCurLexicalContext()->getRedeclContext()))
5077  return false;
5078 
5079  Diag(D->getLocation(), diag::err_objc_decls_may_only_appear_in_global_scope);
5080  D->setInvalidDecl();
5081 
5082  return true;
5083 }
5084 
5085 /// Called whenever \@defs(ClassName) is encountered in the source. Inserts the
5086 /// instance variables of ClassName into Decls.
5087 void Sema::ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
5088  IdentifierInfo *ClassName,
5089  SmallVectorImpl<Decl*> &Decls) {
5090  // Check that ClassName is a valid class
5091  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName, DeclStart);
5092  if (!Class) {
5093  Diag(DeclStart, diag::err_undef_interface) << ClassName;
5094  return;
5095  }
5097  Diag(DeclStart, diag::err_atdef_nonfragile_interface);
5098  return;
5099  }
5100 
5101  // Collect the instance variables
5103  Context.DeepCollectObjCIvars(Class, true, Ivars);
5104  // For each ivar, create a fresh ObjCAtDefsFieldDecl.
5105  for (unsigned i = 0; i < Ivars.size(); i++) {
5106  const FieldDecl* ID = Ivars[i];
5107  RecordDecl *Record = dyn_cast<RecordDecl>(TagD);
5109  /*FIXME: StartL=*/ID->getLocation(),
5110  ID->getLocation(),
5111  ID->getIdentifier(), ID->getType(),
5112  ID->getBitWidth());
5113  Decls.push_back(FD);
5114  }
5115 
5116  // Introduce all of these fields into the appropriate scope.
5117  for (SmallVectorImpl<Decl*>::iterator D = Decls.begin();
5118  D != Decls.end(); ++D) {
5119  FieldDecl *FD = cast<FieldDecl>(*D);
5120  if (getLangOpts().CPlusPlus)
5121  PushOnScopeChains(FD, S);
5122  else if (RecordDecl *Record = dyn_cast<RecordDecl>(TagD))
5123  Record->addDecl(FD);
5124  }
5125 }
5126 
5127 /// Build a type-check a new Objective-C exception variable declaration.
5129  SourceLocation StartLoc,
5130  SourceLocation IdLoc,
5131  IdentifierInfo *Id,
5132  bool Invalid) {
5133  // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
5134  // duration shall not be qualified by an address-space qualifier."
5135  // Since all parameters have automatic store duration, they can not have
5136  // an address space.
5137  if (T.getAddressSpace() != LangAS::Default) {
5138  Diag(IdLoc, diag::err_arg_with_address_space);
5139  Invalid = true;
5140  }
5141 
5142  // An @catch parameter must be an unqualified object pointer type;
5143  // FIXME: Recover from "NSObject foo" by inserting the * in "NSObject *foo"?
5144  if (Invalid) {
5145  // Don't do any further checking.
5146  } else if (T->isDependentType()) {
5147  // Okay: we don't know what this type will instantiate to.
5148  } else if (T->isObjCQualifiedIdType()) {
5149  Invalid = true;
5150  Diag(IdLoc, diag::err_illegal_qualifiers_on_catch_parm);
5151  } else if (T->isObjCIdType()) {
5152  // Okay: we don't know what this type will instantiate to.
5153  } else if (!T->isObjCObjectPointerType()) {
5154  Invalid = true;
5155  Diag(IdLoc, diag::err_catch_param_not_objc_type);
5156  } else if (!T->castAs<ObjCObjectPointerType>()->getInterfaceType()) {
5157  Invalid = true;
5158  Diag(IdLoc, diag::err_catch_param_not_objc_type);
5159  }
5160 
5161  VarDecl *New = VarDecl::Create(Context, CurContext, StartLoc, IdLoc, Id,
5162  T, TInfo, SC_None);
5163  New->setExceptionVariable(true);
5164 
5165  // In ARC, infer 'retaining' for variables of retainable type.
5166  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(New))
5167  Invalid = true;
5168 
5169  if (Invalid)
5170  New->setInvalidDecl();
5171  return New;
5172 }
5173 
5175  const DeclSpec &DS = D.getDeclSpec();
5176 
5177  // We allow the "register" storage class on exception variables because
5178  // GCC did, but we drop it completely. Any other storage class is an error.
5180  Diag(DS.getStorageClassSpecLoc(), diag::warn_register_objc_catch_parm)
5182  } else if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
5183  Diag(DS.getStorageClassSpecLoc(), diag::err_storage_spec_on_catch_parm)
5185  }
5186  if (DS.isInlineSpecified())
5187  Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
5188  << getLangOpts().CPlusPlus17;
5191  diag::err_invalid_thread)
5192  << DeclSpec::getSpecifierName(TSCS);
5194 
5196 
5197  // Check that there are no default arguments inside the type of this
5198  // exception object (C++ only).
5199  if (getLangOpts().CPlusPlus)
5201 
5202  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
5203  QualType ExceptionType = TInfo->getType();
5204 
5205  VarDecl *New = BuildObjCExceptionDecl(TInfo, ExceptionType,
5206  D.getSourceRange().getBegin(),
5207  D.getIdentifierLoc(),
5208  D.getIdentifier(),
5209  D.isInvalidType());
5210 
5211  // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
5212  if (D.getCXXScopeSpec().isSet()) {
5213  Diag(D.getIdentifierLoc(), diag::err_qualified_objc_catch_parm)
5214  << D.getCXXScopeSpec().getRange();
5215  New->setInvalidDecl();
5216  }
5217 
5218  // Add the parameter declaration into this scope.
5219  S->AddDecl(New);
5220  if (D.getIdentifier())
5221  IdResolver.AddDecl(New);
5222 
5223  ProcessDeclAttributes(S, New, D);
5224 
5225  if (New->hasAttr<BlocksAttr>())
5226  Diag(New->getLocation(), diag::err_block_on_nonlocal);
5227  return New;
5228 }
5229 
5230 /// CollectIvarsToConstructOrDestruct - Collect those ivars which require
5231 /// initialization.
5234  for (ObjCIvarDecl *Iv = OI->all_declared_ivar_begin(); Iv;
5235  Iv= Iv->getNextIvar()) {
5236  QualType QT = Context.getBaseElementType(Iv->getType());
5237  if (QT->isRecordType())
5238  Ivars.push_back(Iv);
5239  }
5240 }
5241 
5243  // Load referenced selectors from the external source.
5244  if (ExternalSource) {
5246  ExternalSource->ReadReferencedSelectors(Sels);
5247  for (unsigned I = 0, N = Sels.size(); I != N; ++I)
5248  ReferencedSelectors[Sels[I].first] = Sels[I].second;
5249  }
5250 
5251  // Warning will be issued only when selector table is
5252  // generated (which means there is at lease one implementation
5253  // in the TU). This is to match gcc's behavior.
5254  if (ReferencedSelectors.empty() ||
5256  return;
5257  for (auto &SelectorAndLocation : ReferencedSelectors) {
5258  Selector Sel = SelectorAndLocation.first;
5259  SourceLocation Loc = SelectorAndLocation.second;
5261  Diag(Loc, diag::warn_unimplemented_selector) << Sel;
5262  }
5263 }
5264 
5265 ObjCIvarDecl *
5267  const ObjCPropertyDecl *&PDecl) const {
5268  if (Method->isClassMethod())
5269  return nullptr;
5270  const ObjCInterfaceDecl *IDecl = Method->getClassInterface();
5271  if (!IDecl)
5272  return nullptr;
5273  Method = IDecl->lookupMethod(Method->getSelector(), /*isInstance=*/true,
5274  /*shallowCategoryLookup=*/false,
5275  /*followSuper=*/false);
5276  if (!Method || !Method->isPropertyAccessor())
5277  return nullptr;
5278  if ((PDecl = Method->findPropertyDecl()))
5279  if (ObjCIvarDecl *IV = PDecl->getPropertyIvarDecl()) {
5280  // property backing ivar must belong to property's class
5281  // or be a private ivar in class's implementation.
5282  // FIXME. fix the const-ness issue.
5283  IV = const_cast<ObjCInterfaceDecl *>(IDecl)->lookupInstanceVariable(
5284  IV->getIdentifier());
5285  return IV;
5286  }
5287  return nullptr;
5288 }
5289 
5290 namespace {
5291  /// Used by Sema::DiagnoseUnusedBackingIvarInAccessor to check if a property
5292  /// accessor references the backing ivar.
5293  class UnusedBackingIvarChecker :
5294  public RecursiveASTVisitor<UnusedBackingIvarChecker> {
5295  public:
5296  Sema &S;
5297  const ObjCMethodDecl *Method;
5298  const ObjCIvarDecl *IvarD;
5299  bool AccessedIvar;
5300  bool InvokedSelfMethod;
5301 
5302  UnusedBackingIvarChecker(Sema &S, const ObjCMethodDecl *Method,
5303  const ObjCIvarDecl *IvarD)
5304  : S(S), Method(Method), IvarD(IvarD),
5305  AccessedIvar(false), InvokedSelfMethod(false) {
5306  assert(IvarD);
5307  }
5308 
5309  bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
5310  if (E->getDecl() == IvarD) {
5311  AccessedIvar = true;
5312  return false;
5313  }
5314  return true;
5315  }
5316 
5317  bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
5319  S.isSelfExpr(E->getInstanceReceiver(), Method)) {
5320  InvokedSelfMethod = true;
5321  }
5322  return true;
5323  }
5324  };
5325 } // end anonymous namespace
5326 
5328  const ObjCImplementationDecl *ImplD) {
5329  if (S->hasUnrecoverableErrorOccurred())
5330  return;
5331 
5332  for (const auto *CurMethod : ImplD->instance_methods()) {
5333  unsigned DIAG = diag::warn_unused_property_backing_ivar;
5334  SourceLocation Loc = CurMethod->getLocation();
5335  if (Diags.isIgnored(DIAG, Loc))
5336  continue;
5337 
5338  const ObjCPropertyDecl *PDecl;
5339  const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
5340  if (!IV)
5341  continue;
5342 
5343  if (CurMethod->isSynthesizedAccessorStub())
5344  continue;
5345 
5346  UnusedBackingIvarChecker Checker(*this, CurMethod, IV);
5347  Checker.TraverseStmt(CurMethod->getBody());
5348  if (Checker.AccessedIvar)
5349  continue;
5350 
5351  // Do not issue this warning if backing ivar is used somewhere and accessor
5352  // implementation makes a self call. This is to prevent false positive in
5353  // cases where the ivar is accessed by another method that the accessor
5354  // delegates to.
5355  if (!IV->isReferenced() || !Checker.InvokedSelfMethod) {
5356  Diag(Loc, DIAG) << IV;
5357  Diag(PDecl->getLocation(), diag::note_property_declare);
5358  }
5359  }
5360 }
clang::Decl::setLexicalDeclContext
void setLexicalDeclContext(DeclContext *DC)
Definition: DeclBase.cpp:332
clang::ObjCMethodDecl::Required
@ Required
Definition: DeclObjC.h:144
clang::ObjCInterfaceDecl
Represents an ObjC class declaration.
Definition: DeclObjC.h:1150
clang::ObjCTypeParamDecl::hasExplicitBound
bool hasExplicitBound() const
Whether this type parameter has an explicitly-written type bound, e.g., "T : NSView".
Definition: DeclObjC.h:642
clang::Sema::CurContext
DeclContext * CurContext
CurContext - This is the current declaration context of parsing.
Definition: Sema.h:420
clang::Type::getNullability
Optional< NullabilityKind > getNullability(const ASTContext &context) const
Determine the nullability of the given type.
Definition: Type.cpp:4095
WarnUndefinedMethod
static void WarnUndefinedMethod(Sema &S, ObjCImplDecl *Impl, ObjCMethodDecl *method, bool &IncompleteImpl, unsigned DiagID, NamedDecl *NeededFor=nullptr)
Definition: SemaDeclObjC.cpp:2220
clang::FieldDecl::getBitWidthValue
unsigned getBitWidthValue(const ASTContext &Ctx) const
Definition: Decl.cpp:4278
clang::ObjCObjectPointerTypeLoc
Wraps an ObjCPointerType with source location information.
Definition: TypeLoc.h:1326
clang::Sema::DiagnoseDuplicateIvars
void DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID, ObjCInterfaceDecl *SID)
DiagnoseDuplicateIvars - Check for duplicate ivars in the entire class at the start of @implementatio...
Definition: SemaDeclObjC.cpp:3760
clang::Type::isRecordType
bool isRecordType() const
Definition: Type.h:6897
clang::ObjCCompatibleAliasDecl
ObjCCompatibleAliasDecl - Represents alias of a class.
Definition: DeclObjC.h:2723
clang::ObjCDeclSpec
Captures information about "declaration specifiers" specific to Objective-C.
Definition: DeclSpec.h:823
IsVariableSizedType
static bool IsVariableSizedType(QualType T)
Definition: SemaDeclObjC.cpp:3833
clang::Decl::getASTContext
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:415
clang::QualType::getObjCLifetime
Qualifiers::ObjCLifetime getObjCLifetime() const
Returns lifetime attribute of this type.
Definition: Type.h:1184
clang::RecordDecl::field_begin
field_iterator field_begin() const
Definition: Decl.cpp:4700
clang::ExternalSemaSource::updateOutOfDateSelector
virtual void updateOutOfDateSelector(Selector Sel)
Load the contents of the global method pool for a given selector if necessary.
Definition: Sema.cpp:2366
clang::Sema::CheckFunctionReturnType
bool CheckFunctionReturnType(QualType T, SourceLocation Loc)
Definition: SemaType.cpp:2805
clang::ASTContext::getTypeDeclType
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h: