clang  11.0.0git
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 (!dyn_cast_or_null<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  PushOnScopeChains(IDecl, TUScope);
1070 
1071  // Start the definition of this class. If we're in a redefinition case, there
1072  // may already be a definition, so we'll end up adding to it.
1073  if (!IDecl->hasDefinition())
1074  IDecl->startDefinition();
1075 
1076  if (SuperName) {
1077  // Diagnose availability in the context of the @interface.
1078  ContextRAII SavedContext(*this, IDecl);
1079 
1080  ActOnSuperClassOfClassInterface(S, AtInterfaceLoc, IDecl,
1081  ClassName, ClassLoc,
1082  SuperName, SuperLoc, SuperTypeArgs,
1083  SuperTypeArgsRange);
1084  } else { // we have a root class.
1085  IDecl->setEndOfDefinitionLoc(ClassLoc);
1086  }
1087 
1088  // Check then save referenced protocols.
1089  if (NumProtoRefs) {
1090  diagnoseUseOfProtocols(*this, IDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1091  NumProtoRefs, ProtoLocs);
1092  IDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1093  ProtoLocs, Context);
1094  IDecl->setEndOfDefinitionLoc(EndProtoLoc);
1095  }
1096 
1097  CheckObjCDeclScope(IDecl);
1098  return ActOnObjCContainerStartDefinition(IDecl);
1099 }
1100 
1101 /// ActOnTypedefedProtocols - this action finds protocol list as part of the
1102 /// typedef'ed use for a qualified super class and adds them to the list
1103 /// of the protocols.
1105  SmallVectorImpl<SourceLocation> &ProtocolLocs,
1106  IdentifierInfo *SuperName,
1107  SourceLocation SuperLoc) {
1108  if (!SuperName)
1109  return;
1110  NamedDecl* IDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
1112  if (!IDecl)
1113  return;
1114 
1115  if (const TypedefNameDecl *TDecl = dyn_cast_or_null<TypedefNameDecl>(IDecl)) {
1116  QualType T = TDecl->getUnderlyingType();
1117  if (T->isObjCObjectType())
1118  if (const ObjCObjectType *OPT = T->getAs<ObjCObjectType>()) {
1119  ProtocolRefs.append(OPT->qual_begin(), OPT->qual_end());
1120  // FIXME: Consider whether this should be an invalid loc since the loc
1121  // is not actually pointing to a protocol name reference but to the
1122  // typedef reference. Note that the base class name loc is also pointing
1123  // at the typedef.
1124  ProtocolLocs.append(OPT->getNumProtocols(), SuperLoc);
1125  }
1126  }
1127 }
1128 
1129 /// ActOnCompatibilityAlias - this action is called after complete parsing of
1130 /// a \@compatibility_alias declaration. It sets up the alias relationships.
1132  IdentifierInfo *AliasName,
1133  SourceLocation AliasLocation,
1134  IdentifierInfo *ClassName,
1135  SourceLocation ClassLocation) {
1136  // Look for previous declaration of alias name
1137  NamedDecl *ADecl =
1138  LookupSingleName(TUScope, AliasName, AliasLocation, LookupOrdinaryName,
1140  if (ADecl) {
1141  Diag(AliasLocation, diag::err_conflicting_aliasing_type) << AliasName;
1142  Diag(ADecl->getLocation(), diag::note_previous_declaration);
1143  return nullptr;
1144  }
1145  // Check for class declaration
1146  NamedDecl *CDeclU =
1147  LookupSingleName(TUScope, ClassName, ClassLocation, LookupOrdinaryName,
1149  if (const TypedefNameDecl *TDecl =
1150  dyn_cast_or_null<TypedefNameDecl>(CDeclU)) {
1151  QualType T = TDecl->getUnderlyingType();
1152  if (T->isObjCObjectType()) {
1153  if (NamedDecl *IDecl = T->castAs<ObjCObjectType>()->getInterface()) {
1154  ClassName = IDecl->getIdentifier();
1155  CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation,
1158  }
1159  }
1160  }
1161  ObjCInterfaceDecl *CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDeclU);
1162  if (!CDecl) {
1163  Diag(ClassLocation, diag::warn_undef_interface) << ClassName;
1164  if (CDeclU)
1165  Diag(CDeclU->getLocation(), diag::note_previous_declaration);
1166  return nullptr;
1167  }
1168 
1169  // Everything checked out, instantiate a new alias declaration AST.
1170  ObjCCompatibleAliasDecl *AliasDecl =
1171  ObjCCompatibleAliasDecl::Create(Context, CurContext, AtLoc, AliasName, CDecl);
1172 
1173  if (!CheckObjCDeclScope(AliasDecl))
1174  PushOnScopeChains(AliasDecl, TUScope);
1175 
1176  return AliasDecl;
1177 }
1178 
1180  IdentifierInfo *PName,
1181  SourceLocation &Ploc, SourceLocation PrevLoc,
1182  const ObjCList<ObjCProtocolDecl> &PList) {
1183 
1184  bool res = false;
1186  E = PList.end(); I != E; ++I) {
1187  if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier(),
1188  Ploc)) {
1189  if (PDecl->getIdentifier() == PName) {
1190  Diag(Ploc, diag::err_protocol_has_circular_dependency);
1191  Diag(PrevLoc, diag::note_previous_definition);
1192  res = true;
1193  }
1194 
1195  if (!PDecl->hasDefinition())
1196  continue;
1197 
1199  PDecl->getLocation(), PDecl->getReferencedProtocols()))
1200  res = true;
1201  }
1202  }
1203  return res;
1204 }
1205 
1207  SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName,
1208  SourceLocation ProtocolLoc, Decl *const *ProtoRefs, unsigned NumProtoRefs,
1209  const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
1210  const ParsedAttributesView &AttrList) {
1211  bool err = false;
1212  // FIXME: Deal with AttrList.
1213  assert(ProtocolName && "Missing protocol identifier");
1214  ObjCProtocolDecl *PrevDecl = LookupProtocol(ProtocolName, ProtocolLoc,
1216  ObjCProtocolDecl *PDecl = nullptr;
1217  if (ObjCProtocolDecl *Def = PrevDecl? PrevDecl->getDefinition() : nullptr) {
1218  // If we already have a definition, complain.
1219  Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName;
1220  Diag(Def->getLocation(), diag::note_previous_definition);
1221 
1222  // Create a new protocol that is completely distinct from previous
1223  // declarations, and do not make this protocol available for name lookup.
1224  // That way, we'll end up completely ignoring the duplicate.
1225  // FIXME: Can we turn this into an error?
1226  PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
1227  ProtocolLoc, AtProtoInterfaceLoc,
1228  /*PrevDecl=*/nullptr);
1229 
1230  // If we are using modules, add the decl to the context in order to
1231  // serialize something meaningful.
1232  if (getLangOpts().Modules)
1233  PushOnScopeChains(PDecl, TUScope);
1234  PDecl->startDefinition();
1235  } else {
1236  if (PrevDecl) {
1237  // Check for circular dependencies among protocol declarations. This can
1238  // only happen if this protocol was forward-declared.
1240  PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context);
1242  ProtocolName, ProtocolLoc, PrevDecl->getLocation(), PList);
1243  }
1244 
1245  // Create the new declaration.
1246  PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
1247  ProtocolLoc, AtProtoInterfaceLoc,
1248  /*PrevDecl=*/PrevDecl);
1249 
1250  PushOnScopeChains(PDecl, TUScope);
1251  PDecl->startDefinition();
1252  }
1253 
1254  ProcessDeclAttributeList(TUScope, PDecl, AttrList);
1255  AddPragmaAttributes(TUScope, PDecl);
1256 
1257  // Merge attributes from previous declarations.
1258  if (PrevDecl)
1259  mergeDeclAttributes(PDecl, PrevDecl);
1260 
1261  if (!err && NumProtoRefs ) {
1262  /// Check then save referenced protocols.
1263  diagnoseUseOfProtocols(*this, PDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1264  NumProtoRefs, ProtoLocs);
1265  PDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1266  ProtoLocs, Context);
1267  }
1268 
1269  CheckObjCDeclScope(PDecl);
1270  return ActOnObjCContainerStartDefinition(PDecl);
1271 }
1272 
1274  ObjCProtocolDecl *&UndefinedProtocol) {
1275  if (!PDecl->hasDefinition() ||
1276  !PDecl->getDefinition()->isUnconditionallyVisible()) {
1277  UndefinedProtocol = PDecl;
1278  return true;
1279  }
1280 
1281  for (auto *PI : PDecl->protocols())
1282  if (NestedProtocolHasNoDefinition(PI, UndefinedProtocol)) {
1283  UndefinedProtocol = PI;
1284  return true;
1285  }
1286  return false;
1287 }
1288 
1289 /// FindProtocolDeclaration - This routine looks up protocols and
1290 /// issues an error if they are not declared. It returns list of
1291 /// protocol declarations in its 'Protocols' argument.
1292 void
1293 Sema::FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer,
1294  ArrayRef<IdentifierLocPair> ProtocolId,
1295  SmallVectorImpl<Decl *> &Protocols) {
1296  for (const IdentifierLocPair &Pair : ProtocolId) {
1297  ObjCProtocolDecl *PDecl = LookupProtocol(Pair.first, Pair.second);
1298  if (!PDecl) {
1300  TypoCorrection Corrected = CorrectTypo(
1301  DeclarationNameInfo(Pair.first, Pair.second), LookupObjCProtocolName,
1302  TUScope, nullptr, CCC, CTK_ErrorRecovery);
1303  if ((PDecl = Corrected.getCorrectionDeclAs<ObjCProtocolDecl>()))
1304  diagnoseTypo(Corrected, PDiag(diag::err_undeclared_protocol_suggest)
1305  << Pair.first);
1306  }
1307 
1308  if (!PDecl) {
1309  Diag(Pair.second, diag::err_undeclared_protocol) << Pair.first;
1310  continue;
1311  }
1312  // If this is a forward protocol declaration, get its definition.
1313  if (!PDecl->isThisDeclarationADefinition() && PDecl->getDefinition())
1314  PDecl = PDecl->getDefinition();
1315 
1316  // For an objc container, delay protocol reference checking until after we
1317  // can set the objc decl as the availability context, otherwise check now.
1318  if (!ForObjCContainer) {
1319  (void)DiagnoseUseOfDecl(PDecl, Pair.second);
1320  }
1321 
1322  // If this is a forward declaration and we are supposed to warn in this
1323  // case, do it.
1324  // FIXME: Recover nicely in the hidden case.
1325  ObjCProtocolDecl *UndefinedProtocol;
1326 
1327  if (WarnOnDeclarations &&
1328  NestedProtocolHasNoDefinition(PDecl, UndefinedProtocol)) {
1329  Diag(Pair.second, diag::warn_undef_protocolref) << Pair.first;
1330  Diag(UndefinedProtocol->getLocation(), diag::note_protocol_decl_undefined)
1331  << UndefinedProtocol;
1332  }
1333  Protocols.push_back(PDecl);
1334  }
1335 }
1336 
1337 namespace {
1338 // Callback to only accept typo corrections that are either
1339 // Objective-C protocols or valid Objective-C type arguments.
1340 class ObjCTypeArgOrProtocolValidatorCCC final
1341  : public CorrectionCandidateCallback {
1343  Sema::LookupNameKind LookupKind;
1344  public:
1345  ObjCTypeArgOrProtocolValidatorCCC(ASTContext &context,
1346  Sema::LookupNameKind lookupKind)
1347  : Context(context), LookupKind(lookupKind) { }
1348 
1349  bool ValidateCandidate(const TypoCorrection &candidate) override {
1350  // If we're allowed to find protocols and we have a protocol, accept it.
1351  if (LookupKind != Sema::LookupOrdinaryName) {
1352  if (candidate.getCorrectionDeclAs<ObjCProtocolDecl>())
1353  return true;
1354  }
1355 
1356  // If we're allowed to find type names and we have one, accept it.
1357  if (LookupKind != Sema::LookupObjCProtocolName) {
1358  // If we have a type declaration, we might accept this result.
1359  if (auto typeDecl = candidate.getCorrectionDeclAs<TypeDecl>()) {
1360  // If we found a tag declaration outside of C++, skip it. This
1361  // can happy because we look for any name when there is no
1362  // bias to protocol or type names.
1363  if (isa<RecordDecl>(typeDecl) && !Context.getLangOpts().CPlusPlus)
1364  return false;
1365 
1366  // Make sure the type is something we would accept as a type
1367  // argument.
1368  auto type = Context.getTypeDeclType(typeDecl);
1369  if (type->isObjCObjectPointerType() ||
1370  type->isBlockPointerType() ||
1371  type->isDependentType() ||
1372  type->isObjCObjectType())
1373  return true;
1374 
1375  return false;
1376  }
1377 
1378  // If we have an Objective-C class type, accept it; there will
1379  // be another fix to add the '*'.
1380  if (candidate.getCorrectionDeclAs<ObjCInterfaceDecl>())
1381  return true;
1382 
1383  return false;
1384  }
1385 
1386  return false;
1387  }
1388 
1389  std::unique_ptr<CorrectionCandidateCallback> clone() override {
1390  return std::make_unique<ObjCTypeArgOrProtocolValidatorCCC>(*this);
1391  }
1392 };
1393 } // end anonymous namespace
1394 
1396  SourceLocation ProtocolLoc,
1397  IdentifierInfo *TypeArgId,
1398  SourceLocation TypeArgLoc,
1399  bool SelectProtocolFirst) {
1400  Diag(TypeArgLoc, diag::err_objc_type_args_and_protocols)
1401  << SelectProtocolFirst << TypeArgId << ProtocolId
1402  << SourceRange(ProtocolLoc);
1403 }
1404 
1406  Scope *S,
1407  ParsedType baseType,
1408  SourceLocation lAngleLoc,
1409  ArrayRef<IdentifierInfo *> identifiers,
1410  ArrayRef<SourceLocation> identifierLocs,
1411  SourceLocation rAngleLoc,
1412  SourceLocation &typeArgsLAngleLoc,
1413  SmallVectorImpl<ParsedType> &typeArgs,
1414  SourceLocation &typeArgsRAngleLoc,
1415  SourceLocation &protocolLAngleLoc,
1416  SmallVectorImpl<Decl *> &protocols,
1417  SourceLocation &protocolRAngleLoc,
1418  bool warnOnIncompleteProtocols) {
1419  // Local function that updates the declaration specifiers with
1420  // protocol information.
1421  unsigned numProtocolsResolved = 0;
1422  auto resolvedAsProtocols = [&] {
1423  assert(numProtocolsResolved == identifiers.size() && "Unresolved protocols");
1424 
1425  // Determine whether the base type is a parameterized class, in
1426  // which case we want to warn about typos such as
1427  // "NSArray<NSObject>" (that should be NSArray<NSObject *>).
1428  ObjCInterfaceDecl *baseClass = nullptr;
1429  QualType base = GetTypeFromParser(baseType, nullptr);
1430  bool allAreTypeNames = false;
1431  SourceLocation firstClassNameLoc;
1432  if (!base.isNull()) {
1433  if (const auto *objcObjectType = base->getAs<ObjCObjectType>()) {
1434  baseClass = objcObjectType->getInterface();
1435  if (baseClass) {
1436  if (auto typeParams = baseClass->getTypeParamList()) {
1437  if (typeParams->size() == numProtocolsResolved) {
1438  // Note that we should be looking for type names, too.
1439  allAreTypeNames = true;
1440  }
1441  }
1442  }
1443  }
1444  }
1445 
1446  for (unsigned i = 0, n = protocols.size(); i != n; ++i) {
1447  ObjCProtocolDecl *&proto
1448  = reinterpret_cast<ObjCProtocolDecl *&>(protocols[i]);
1449  // For an objc container, delay protocol reference checking until after we
1450  // can set the objc decl as the availability context, otherwise check now.
1451  if (!warnOnIncompleteProtocols) {
1452  (void)DiagnoseUseOfDecl(proto, identifierLocs[i]);
1453  }
1454 
1455  // If this is a forward protocol declaration, get its definition.
1456  if (!proto->isThisDeclarationADefinition() && proto->getDefinition())
1457  proto = proto->getDefinition();
1458 
1459  // If this is a forward declaration and we are supposed to warn in this
1460  // case, do it.
1461  // FIXME: Recover nicely in the hidden case.
1462  ObjCProtocolDecl *forwardDecl = nullptr;
1463  if (warnOnIncompleteProtocols &&
1464  NestedProtocolHasNoDefinition(proto, forwardDecl)) {
1465  Diag(identifierLocs[i], diag::warn_undef_protocolref)
1466  << proto->getDeclName();
1467  Diag(forwardDecl->getLocation(), diag::note_protocol_decl_undefined)
1468  << forwardDecl;
1469  }
1470 
1471  // If everything this far has been a type name (and we care
1472  // about such things), check whether this name refers to a type
1473  // as well.
1474  if (allAreTypeNames) {
1475  if (auto *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
1476  LookupOrdinaryName)) {
1477  if (isa<ObjCInterfaceDecl>(decl)) {
1478  if (firstClassNameLoc.isInvalid())
1479  firstClassNameLoc = identifierLocs[i];
1480  } else if (!isa<TypeDecl>(decl)) {
1481  // Not a type.
1482  allAreTypeNames = false;
1483  }
1484  } else {
1485  allAreTypeNames = false;
1486  }
1487  }
1488  }
1489 
1490  // All of the protocols listed also have type names, and at least
1491  // one is an Objective-C class name. Check whether all of the
1492  // protocol conformances are declared by the base class itself, in
1493  // which case we warn.
1494  if (allAreTypeNames && firstClassNameLoc.isValid()) {
1496  Context.CollectInheritedProtocols(baseClass, knownProtocols);
1497  bool allProtocolsDeclared = true;
1498  for (auto proto : protocols) {
1499  if (knownProtocols.count(static_cast<ObjCProtocolDecl *>(proto)) == 0) {
1500  allProtocolsDeclared = false;
1501  break;
1502  }
1503  }
1504 
1505  if (allProtocolsDeclared) {
1506  Diag(firstClassNameLoc, diag::warn_objc_redundant_qualified_class_type)
1507  << baseClass->getDeclName() << SourceRange(lAngleLoc, rAngleLoc)
1508  << FixItHint::CreateInsertion(getLocForEndOfToken(firstClassNameLoc),
1509  " *");
1510  }
1511  }
1512 
1513  protocolLAngleLoc = lAngleLoc;
1514  protocolRAngleLoc = rAngleLoc;
1515  assert(protocols.size() == identifierLocs.size());
1516  };
1517 
1518  // Attempt to resolve all of the identifiers as protocols.
1519  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1520  ObjCProtocolDecl *proto = LookupProtocol(identifiers[i], identifierLocs[i]);
1521  protocols.push_back(proto);
1522  if (proto)
1523  ++numProtocolsResolved;
1524  }
1525 
1526  // If all of the names were protocols, these were protocol qualifiers.
1527  if (numProtocolsResolved == identifiers.size())
1528  return resolvedAsProtocols();
1529 
1530  // Attempt to resolve all of the identifiers as type names or
1531  // Objective-C class names. The latter is technically ill-formed,
1532  // but is probably something like \c NSArray<NSView *> missing the
1533  // \c*.
1534  typedef llvm::PointerUnion<TypeDecl *, ObjCInterfaceDecl *> TypeOrClassDecl;
1536  unsigned numTypeDeclsResolved = 0;
1537  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1538  NamedDecl *decl = LookupSingleName(S, identifiers[i], identifierLocs[i],
1540  if (!decl) {
1541  typeDecls.push_back(TypeOrClassDecl());
1542  continue;
1543  }
1544 
1545  if (auto typeDecl = dyn_cast<TypeDecl>(decl)) {
1546  typeDecls.push_back(typeDecl);
1547  ++numTypeDeclsResolved;
1548  continue;
1549  }
1550 
1551  if (auto objcClass = dyn_cast<ObjCInterfaceDecl>(decl)) {
1552  typeDecls.push_back(objcClass);
1553  ++numTypeDeclsResolved;
1554  continue;
1555  }
1556 
1557  typeDecls.push_back(TypeOrClassDecl());
1558  }
1559 
1560  AttributeFactory attrFactory;
1561 
1562  // Local function that forms a reference to the given type or
1563  // Objective-C class declaration.
1564  auto resolveTypeReference = [&](TypeOrClassDecl typeDecl, SourceLocation loc)
1565  -> TypeResult {
1566  // Form declaration specifiers. They simply refer to the type.
1567  DeclSpec DS(attrFactory);
1568  const char* prevSpec; // unused
1569  unsigned diagID; // unused
1570  QualType type;
1571  if (auto *actualTypeDecl = typeDecl.dyn_cast<TypeDecl *>())
1572  type = Context.getTypeDeclType(actualTypeDecl);
1573  else
1574  type = Context.getObjCInterfaceType(typeDecl.get<ObjCInterfaceDecl *>());
1575  TypeSourceInfo *parsedTSInfo = Context.getTrivialTypeSourceInfo(type, loc);
1576  ParsedType parsedType = CreateParsedType(type, parsedTSInfo);
1577  DS.SetTypeSpecType(DeclSpec::TST_typename, loc, prevSpec, diagID,
1578  parsedType, Context.getPrintingPolicy());
1579  // Use the identifier location for the type source range.
1580  DS.SetRangeStart(loc);
1581  DS.SetRangeEnd(loc);
1582 
1583  // Form the declarator.
1585 
1586  // If we have a typedef of an Objective-C class type that is missing a '*',
1587  // add the '*'.
1588  if (type->getAs<ObjCInterfaceType>()) {
1589  SourceLocation starLoc = getLocForEndOfToken(loc);
1590  D.AddTypeInfo(DeclaratorChunk::getPointer(/*TypeQuals=*/0, starLoc,
1591  SourceLocation(),
1592  SourceLocation(),
1593  SourceLocation(),
1594  SourceLocation(),
1595  SourceLocation()),
1596  starLoc);
1597 
1598  // Diagnose the missing '*'.
1599  Diag(loc, diag::err_objc_type_arg_missing_star)
1600  << type
1601  << FixItHint::CreateInsertion(starLoc, " *");
1602  }
1603 
1604  // Convert this to a type.
1605  return ActOnTypeName(S, D);
1606  };
1607 
1608  // Local function that updates the declaration specifiers with
1609  // type argument information.
1610  auto resolvedAsTypeDecls = [&] {
1611  // We did not resolve these as protocols.
1612  protocols.clear();
1613 
1614  assert(numTypeDeclsResolved == identifiers.size() && "Unresolved type decl");
1615  // Map type declarations to type arguments.
1616  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1617  // Map type reference to a type.
1618  TypeResult type = resolveTypeReference(typeDecls[i], identifierLocs[i]);
1619  if (!type.isUsable()) {
1620  typeArgs.clear();
1621  return;
1622  }
1623 
1624  typeArgs.push_back(type.get());
1625  }
1626 
1627  typeArgsLAngleLoc = lAngleLoc;
1628  typeArgsRAngleLoc = rAngleLoc;
1629  };
1630 
1631  // If all of the identifiers can be resolved as type names or
1632  // Objective-C class names, we have type arguments.
1633  if (numTypeDeclsResolved == identifiers.size())
1634  return resolvedAsTypeDecls();
1635 
1636  // Error recovery: some names weren't found, or we have a mix of
1637  // type and protocol names. Go resolve all of the unresolved names
1638  // and complain if we can't find a consistent answer.
1639  LookupNameKind lookupKind = LookupAnyName;
1640  for (unsigned i = 0, n = identifiers.size(); i != n; ++i) {
1641  // If we already have a protocol or type. Check whether it is the
1642  // right thing.
1643  if (protocols[i] || typeDecls[i]) {
1644  // If we haven't figured out whether we want types or protocols
1645  // yet, try to figure it out from this name.
1646  if (lookupKind == LookupAnyName) {
1647  // If this name refers to both a protocol and a type (e.g., \c
1648  // NSObject), don't conclude anything yet.
1649  if (protocols[i] && typeDecls[i])
1650  continue;
1651 
1652  // Otherwise, let this name decide whether we'll be correcting
1653  // toward types or protocols.
1654  lookupKind = protocols[i] ? LookupObjCProtocolName
1656  continue;
1657  }
1658 
1659  // If we want protocols and we have a protocol, there's nothing
1660  // more to do.
1661  if (lookupKind == LookupObjCProtocolName && protocols[i])
1662  continue;
1663 
1664  // If we want types and we have a type declaration, there's
1665  // nothing more to do.
1666  if (lookupKind == LookupOrdinaryName && typeDecls[i])
1667  continue;
1668 
1669  // We have a conflict: some names refer to protocols and others
1670  // refer to types.
1671  DiagnoseTypeArgsAndProtocols(identifiers[0], identifierLocs[0],
1672  identifiers[i], identifierLocs[i],
1673  protocols[i] != nullptr);
1674 
1675  protocols.clear();
1676  typeArgs.clear();
1677  return;
1678  }
1679 
1680  // Perform typo correction on the name.
1681  ObjCTypeArgOrProtocolValidatorCCC CCC(Context, lookupKind);
1682  TypoCorrection corrected =
1683  CorrectTypo(DeclarationNameInfo(identifiers[i], identifierLocs[i]),
1684  lookupKind, S, nullptr, CCC, CTK_ErrorRecovery);
1685  if (corrected) {
1686  // Did we find a protocol?
1687  if (auto proto = corrected.getCorrectionDeclAs<ObjCProtocolDecl>()) {
1688  diagnoseTypo(corrected,
1689  PDiag(diag::err_undeclared_protocol_suggest)
1690  << identifiers[i]);
1691  lookupKind = LookupObjCProtocolName;
1692  protocols[i] = proto;
1693  ++numProtocolsResolved;
1694  continue;
1695  }
1696 
1697  // Did we find a type?
1698  if (auto typeDecl = corrected.getCorrectionDeclAs<TypeDecl>()) {
1699  diagnoseTypo(corrected,
1700  PDiag(diag::err_unknown_typename_suggest)
1701  << identifiers[i]);
1702  lookupKind = LookupOrdinaryName;
1703  typeDecls[i] = typeDecl;
1704  ++numTypeDeclsResolved;
1705  continue;
1706  }
1707 
1708  // Did we find an Objective-C class?
1709  if (auto objcClass = corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1710  diagnoseTypo(corrected,
1711  PDiag(diag::err_unknown_type_or_class_name_suggest)
1712  << identifiers[i] << true);
1713  lookupKind = LookupOrdinaryName;
1714  typeDecls[i] = objcClass;
1715  ++numTypeDeclsResolved;
1716  continue;
1717  }
1718  }
1719 
1720  // We couldn't find anything.
1721  Diag(identifierLocs[i],
1722  (lookupKind == LookupAnyName ? diag::err_objc_type_arg_missing
1723  : lookupKind == LookupObjCProtocolName ? diag::err_undeclared_protocol
1724  : diag::err_unknown_typename))
1725  << identifiers[i];
1726  protocols.clear();
1727  typeArgs.clear();
1728  return;
1729  }
1730 
1731  // If all of the names were (corrected to) protocols, these were
1732  // protocol qualifiers.
1733  if (numProtocolsResolved == identifiers.size())
1734  return resolvedAsProtocols();
1735 
1736  // Otherwise, all of the names were (corrected to) types.
1737  assert(numTypeDeclsResolved == identifiers.size() && "Not all types?");
1738  return resolvedAsTypeDecls();
1739 }
1740 
1741 /// DiagnoseClassExtensionDupMethods - Check for duplicate declaration of
1742 /// a class method in its extension.
1743 ///
1745  ObjCInterfaceDecl *ID) {
1746  if (!ID)
1747  return; // Possibly due to previous error
1748 
1749  llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap;
1750  for (auto *MD : ID->methods())
1751  MethodMap[MD->getSelector()] = MD;
1752 
1753  if (MethodMap.empty())
1754  return;
1755  for (const auto *Method : CAT->methods()) {
1756  const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()];
1757  if (PrevMethod &&
1758  (PrevMethod->isInstanceMethod() == Method->isInstanceMethod()) &&
1759  !MatchTwoMethodDeclarations(Method, PrevMethod)) {
1760  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
1761  << Method->getDeclName();
1762  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
1763  }
1764  }
1765 }
1766 
1767 /// ActOnForwardProtocolDeclaration - Handle \@protocol foo;
1770  ArrayRef<IdentifierLocPair> IdentList,
1771  const ParsedAttributesView &attrList) {
1772  SmallVector<Decl *, 8> DeclsInGroup;
1773  for (const IdentifierLocPair &IdentPair : IdentList) {
1774  IdentifierInfo *Ident = IdentPair.first;
1775  ObjCProtocolDecl *PrevDecl = LookupProtocol(Ident, IdentPair.second,
1777  ObjCProtocolDecl *PDecl
1779  IdentPair.second, AtProtocolLoc,
1780  PrevDecl);
1781 
1782  PushOnScopeChains(PDecl, TUScope);
1783  CheckObjCDeclScope(PDecl);
1784 
1785  ProcessDeclAttributeList(TUScope, PDecl, attrList);
1786  AddPragmaAttributes(TUScope, PDecl);
1787 
1788  if (PrevDecl)
1789  mergeDeclAttributes(PDecl, PrevDecl);
1790 
1791  DeclsInGroup.push_back(PDecl);
1792  }
1793 
1794  return BuildDeclaratorGroup(DeclsInGroup);
1795 }
1796 
1798  SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
1799  SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
1800  IdentifierInfo *CategoryName, SourceLocation CategoryLoc,
1801  Decl *const *ProtoRefs, unsigned NumProtoRefs,
1802  const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
1803  const ParsedAttributesView &AttrList) {
1804  ObjCCategoryDecl *CDecl;
1805  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
1806 
1807  /// Check that class of this category is already completely declared.
1808 
1809  if (!IDecl
1810  || RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
1811  diag::err_category_forward_interface,
1812  CategoryName == nullptr)) {
1813  // Create an invalid ObjCCategoryDecl to serve as context for
1814  // the enclosing method declarations. We mark the decl invalid
1815  // to make it clear that this isn't a valid AST.
1816  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
1817  ClassLoc, CategoryLoc, CategoryName,
1818  IDecl, typeParamList);
1819  CDecl->setInvalidDecl();
1820  CurContext->addDecl(CDecl);
1821 
1822  if (!IDecl)
1823  Diag(ClassLoc, diag::err_undef_interface) << ClassName;
1824  return ActOnObjCContainerStartDefinition(CDecl);
1825  }
1826 
1827  if (!CategoryName && IDecl->getImplementation()) {
1828  Diag(ClassLoc, diag::err_class_extension_after_impl) << ClassName;
1829  Diag(IDecl->getImplementation()->getLocation(),
1830  diag::note_implementation_declared);
1831  }
1832 
1833  if (CategoryName) {
1834  /// Check for duplicate interface declaration for this category
1836  = IDecl->FindCategoryDeclaration(CategoryName)) {
1837  // Class extensions can be declared multiple times, categories cannot.
1838  Diag(CategoryLoc, diag::warn_dup_category_def)
1839  << ClassName << CategoryName;
1840  Diag(Previous->getLocation(), diag::note_previous_definition);
1841  }
1842  }
1843 
1844  // If we have a type parameter list, check it.
1845  if (typeParamList) {
1846  if (auto prevTypeParamList = IDecl->getTypeParamList()) {
1847  if (checkTypeParamListConsistency(*this, prevTypeParamList, typeParamList,
1848  CategoryName
1850  : TypeParamListContext::Extension))
1851  typeParamList = nullptr;
1852  } else {
1853  Diag(typeParamList->getLAngleLoc(),
1854  diag::err_objc_parameterized_category_nonclass)
1855  << (CategoryName != nullptr)
1856  << ClassName
1857  << typeParamList->getSourceRange();
1858 
1859  typeParamList = nullptr;
1860  }
1861  }
1862 
1863  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
1864  ClassLoc, CategoryLoc, CategoryName, IDecl,
1865  typeParamList);
1866  // FIXME: PushOnScopeChains?
1867  CurContext->addDecl(CDecl);
1868 
1869  // Process the attributes before looking at protocols to ensure that the
1870  // availability attribute is attached to the category to provide availability
1871  // checking for protocol uses.
1872  ProcessDeclAttributeList(TUScope, CDecl, AttrList);
1873  AddPragmaAttributes(TUScope, CDecl);
1874 
1875  if (NumProtoRefs) {
1876  diagnoseUseOfProtocols(*this, CDecl, (ObjCProtocolDecl*const*)ProtoRefs,
1877  NumProtoRefs, ProtoLocs);
1878  CDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
1879  ProtoLocs, Context);
1880  // Protocols in the class extension belong to the class.
1881  if (CDecl->IsClassExtension())
1882  IDecl->mergeClassExtensionProtocolList((ObjCProtocolDecl*const*)ProtoRefs,
1883  NumProtoRefs, Context);
1884  }
1885 
1886  CheckObjCDeclScope(CDecl);
1887  return ActOnObjCContainerStartDefinition(CDecl);
1888 }
1889 
1890 /// ActOnStartCategoryImplementation - Perform semantic checks on the
1891 /// category implementation declaration and build an ObjCCategoryImplDecl
1892 /// object.
1894  SourceLocation AtCatImplLoc,
1895  IdentifierInfo *ClassName, SourceLocation ClassLoc,
1896  IdentifierInfo *CatName, SourceLocation CatLoc,
1897  const ParsedAttributesView &Attrs) {
1898  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
1899  ObjCCategoryDecl *CatIDecl = nullptr;
1900  if (IDecl && IDecl->hasDefinition()) {
1901  CatIDecl = IDecl->FindCategoryDeclaration(CatName);
1902  if (!CatIDecl) {
1903  // Category @implementation with no corresponding @interface.
1904  // Create and install one.
1905  CatIDecl = ObjCCategoryDecl::Create(Context, CurContext, AtCatImplLoc,
1906  ClassLoc, CatLoc,
1907  CatName, IDecl,
1908  /*typeParamList=*/nullptr);
1909  CatIDecl->setImplicit();
1910  }
1911  }
1912 
1913  ObjCCategoryImplDecl *CDecl =
1915  ClassLoc, AtCatImplLoc, CatLoc);
1916  /// Check that class of this category is already completely declared.
1917  if (!IDecl) {
1918  Diag(ClassLoc, diag::err_undef_interface) << ClassName;
1919  CDecl->setInvalidDecl();
1920  } else if (RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
1921  diag::err_undef_interface)) {
1922  CDecl->setInvalidDecl();
1923  }
1924 
1925  ProcessDeclAttributeList(TUScope, CDecl, Attrs);
1926  AddPragmaAttributes(TUScope, CDecl);
1927 
1928  // FIXME: PushOnScopeChains?
1929  CurContext->addDecl(CDecl);
1930 
1931  // If the interface has the objc_runtime_visible attribute, we
1932  // cannot implement a category for it.
1933  if (IDecl && IDecl->hasAttr<ObjCRuntimeVisibleAttr>()) {
1934  Diag(ClassLoc, diag::err_objc_runtime_visible_category)
1935  << IDecl->getDeclName();
1936  }
1937 
1938  /// Check that CatName, category name, is not used in another implementation.
1939  if (CatIDecl) {
1940  if (CatIDecl->getImplementation()) {
1941  Diag(ClassLoc, diag::err_dup_implementation_category) << ClassName
1942  << CatName;
1943  Diag(CatIDecl->getImplementation()->getLocation(),
1944  diag::note_previous_definition);
1945  CDecl->setInvalidDecl();
1946  } else {
1947  CatIDecl->setImplementation(CDecl);
1948  // Warn on implementating category of deprecated class under
1949  // -Wdeprecated-implementations flag.
1950  DiagnoseObjCImplementedDeprecations(*this, CatIDecl,
1951  CDecl->getLocation());
1952  }
1953  }
1954 
1955  CheckObjCDeclScope(CDecl);
1956  return ActOnObjCContainerStartDefinition(CDecl);
1957 }
1958 
1960  SourceLocation AtClassImplLoc,
1961  IdentifierInfo *ClassName, SourceLocation ClassLoc,
1962  IdentifierInfo *SuperClassname,
1963  SourceLocation SuperClassLoc,
1964  const ParsedAttributesView &Attrs) {
1965  ObjCInterfaceDecl *IDecl = nullptr;
1966  // Check for another declaration kind with the same name.
1967  NamedDecl *PrevDecl
1968  = LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
1970  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
1971  Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
1972  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1973  } else if ((IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl))) {
1974  // FIXME: This will produce an error if the definition of the interface has
1975  // been imported from a module but is not visible.
1977  diag::warn_undef_interface);
1978  } else {
1979  // We did not find anything with the name ClassName; try to correct for
1980  // typos in the class name.
1981  ObjCInterfaceValidatorCCC CCC{};
1982  TypoCorrection Corrected =
1983  CorrectTypo(DeclarationNameInfo(ClassName, ClassLoc),
1984  LookupOrdinaryName, TUScope, nullptr, CCC, CTK_NonError);
1985  if (Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
1986  // Suggest the (potentially) correct interface name. Don't provide a
1987  // code-modification hint or use the typo name for recovery, because
1988  // this is just a warning. The program may actually be correct.
1989  diagnoseTypo(Corrected,
1990  PDiag(diag::warn_undef_interface_suggest) << ClassName,
1991  /*ErrorRecovery*/false);
1992  } else {
1993  Diag(ClassLoc, diag::warn_undef_interface) << ClassName;
1994  }
1995  }
1996 
1997  // Check that super class name is valid class name
1998  ObjCInterfaceDecl *SDecl = nullptr;
1999  if (SuperClassname) {
2000  // Check if a different kind of symbol declared in this scope.
2001  PrevDecl = LookupSingleName(TUScope, SuperClassname, SuperClassLoc,
2003  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
2004  Diag(SuperClassLoc, diag::err_redefinition_different_kind)
2005  << SuperClassname;
2006  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
2007  } else {
2008  SDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
2009  if (SDecl && !SDecl->hasDefinition())
2010  SDecl = nullptr;
2011  if (!SDecl)
2012  Diag(SuperClassLoc, diag::err_undef_superclass)
2013  << SuperClassname << ClassName;
2014  else if (IDecl && !declaresSameEntity(IDecl->getSuperClass(), SDecl)) {
2015  // This implementation and its interface do not have the same
2016  // super class.
2017  Diag(SuperClassLoc, diag::err_conflicting_super_class)
2018  << SDecl->getDeclName();
2019  Diag(SDecl->getLocation(), diag::note_previous_definition);
2020  }
2021  }
2022  }
2023 
2024  if (!IDecl) {
2025  // Legacy case of @implementation with no corresponding @interface.
2026  // Build, chain & install the interface decl into the identifier.
2027 
2028  // FIXME: Do we support attributes on the @implementation? If so we should
2029  // copy them over.
2030  IDecl = ObjCInterfaceDecl::Create(Context, CurContext, AtClassImplLoc,
2031  ClassName, /*typeParamList=*/nullptr,
2032  /*PrevDecl=*/nullptr, ClassLoc,
2033  true);
2034  AddPragmaAttributes(TUScope, IDecl);
2035  IDecl->startDefinition();
2036  if (SDecl) {
2039  SuperClassLoc));
2040  IDecl->setEndOfDefinitionLoc(SuperClassLoc);
2041  } else {
2042  IDecl->setEndOfDefinitionLoc(ClassLoc);
2043  }
2044 
2045  PushOnScopeChains(IDecl, TUScope);
2046  } else {
2047  // Mark the interface as being completed, even if it was just as
2048  // @class ....;
2049  // declaration; the user cannot reopen it.
2050  if (!IDecl->hasDefinition())
2051  IDecl->startDefinition();
2052  }
2053 
2054  ObjCImplementationDecl* IMPDecl =
2056  ClassLoc, AtClassImplLoc, SuperClassLoc);
2057 
2058  ProcessDeclAttributeList(TUScope, IMPDecl, Attrs);
2059  AddPragmaAttributes(TUScope, IMPDecl);
2060 
2061  if (CheckObjCDeclScope(IMPDecl))
2062  return ActOnObjCContainerStartDefinition(IMPDecl);
2063 
2064  // Check that there is no duplicate implementation of this class.
2065  if (IDecl->getImplementation()) {
2066  // FIXME: Don't leak everything!
2067  Diag(ClassLoc, diag::err_dup_implementation_class) << ClassName;
2068  Diag(IDecl->getImplementation()->getLocation(),
2069  diag::note_previous_definition);
2070  IMPDecl->setInvalidDecl();
2071  } else { // add it to the list.
2072  IDecl->setImplementation(IMPDecl);
2073  PushOnScopeChains(IMPDecl, TUScope);
2074  // Warn on implementating deprecated class under
2075  // -Wdeprecated-implementations flag.
2076  DiagnoseObjCImplementedDeprecations(*this, IDecl, IMPDecl->getLocation());
2077  }
2078 
2079  // If the superclass has the objc_runtime_visible attribute, we
2080  // cannot implement a subclass of it.
2081  if (IDecl->getSuperClass() &&
2082  IDecl->getSuperClass()->hasAttr<ObjCRuntimeVisibleAttr>()) {
2083  Diag(ClassLoc, diag::err_objc_runtime_visible_subclass)
2084  << IDecl->getDeclName()
2085  << IDecl->getSuperClass()->getDeclName();
2086  }
2087 
2088  return ActOnObjCContainerStartDefinition(IMPDecl);
2089 }
2090 
2093  SmallVector<Decl *, 64> DeclsInGroup;
2094  DeclsInGroup.reserve(Decls.size() + 1);
2095 
2096  for (unsigned i = 0, e = Decls.size(); i != e; ++i) {
2097  Decl *Dcl = Decls[i];
2098  if (!Dcl)
2099  continue;
2100  if (Dcl->getDeclContext()->isFileContext())
2102  DeclsInGroup.push_back(Dcl);
2103  }
2104 
2105  DeclsInGroup.push_back(ObjCImpDecl);
2106 
2107  return BuildDeclaratorGroup(DeclsInGroup);
2108 }
2109 
2111  ObjCIvarDecl **ivars, unsigned numIvars,
2112  SourceLocation RBrace) {
2113  assert(ImpDecl && "missing implementation decl");
2114  ObjCInterfaceDecl* IDecl = ImpDecl->getClassInterface();
2115  if (!IDecl)
2116  return;
2117  /// Check case of non-existing \@interface decl.
2118  /// (legacy objective-c \@implementation decl without an \@interface decl).
2119  /// Add implementations's ivar to the synthesize class's ivar list.
2120  if (IDecl->isImplicitInterfaceDecl()) {
2121  IDecl->setEndOfDefinitionLoc(RBrace);
2122  // Add ivar's to class's DeclContext.
2123  for (unsigned i = 0, e = numIvars; i != e; ++i) {
2124  ivars[i]->setLexicalDeclContext(ImpDecl);
2125  IDecl->makeDeclVisibleInContext(ivars[i]);
2126  ImpDecl->addDecl(ivars[i]);
2127  }
2128 
2129  return;
2130  }
2131  // If implementation has empty ivar list, just return.
2132  if (numIvars == 0)
2133  return;
2134 
2135  assert(ivars && "missing @implementation ivars");
2137  if (ImpDecl->getSuperClass())
2138  Diag(ImpDecl->getLocation(), diag::warn_on_superclass_use);
2139  for (unsigned i = 0; i < numIvars; i++) {
2140  ObjCIvarDecl* ImplIvar = ivars[i];
2141  if (const ObjCIvarDecl *ClsIvar =
2142  IDecl->getIvarDecl(ImplIvar->getIdentifier())) {
2143  Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
2144  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2145  continue;
2146  }
2147  // Check class extensions (unnamed categories) for duplicate ivars.
2148  for (const auto *CDecl : IDecl->visible_extensions()) {
2149  if (const ObjCIvarDecl *ClsExtIvar =
2150  CDecl->getIvarDecl(ImplIvar->getIdentifier())) {
2151  Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
2152  Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
2153  continue;
2154  }
2155  }
2156  // Instance ivar to Implementation's DeclContext.
2157  ImplIvar->setLexicalDeclContext(ImpDecl);
2158  IDecl->makeDeclVisibleInContext(ImplIvar);
2159  ImpDecl->addDecl(ImplIvar);
2160  }
2161  return;
2162  }
2163  // Check interface's Ivar list against those in the implementation.
2164  // names and types must match.
2165  //
2166  unsigned j = 0;
2168  IVI = IDecl->ivar_begin(), IVE = IDecl->ivar_end();
2169  for (; numIvars > 0 && IVI != IVE; ++IVI) {
2170  ObjCIvarDecl* ImplIvar = ivars[j++];
2171  ObjCIvarDecl* ClsIvar = *IVI;
2172  assert (ImplIvar && "missing implementation ivar");
2173  assert (ClsIvar && "missing class ivar");
2174 
2175  // First, make sure the types match.
2176  if (!Context.hasSameType(ImplIvar->getType(), ClsIvar->getType())) {
2177  Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_type)
2178  << ImplIvar->getIdentifier()
2179  << ImplIvar->getType() << ClsIvar->getType();
2180  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2181  } else if (ImplIvar->isBitField() && ClsIvar->isBitField() &&
2182  ImplIvar->getBitWidthValue(Context) !=
2183  ClsIvar->getBitWidthValue(Context)) {
2184  Diag(ImplIvar->getBitWidth()->getBeginLoc(),
2185  diag::err_conflicting_ivar_bitwidth)
2186  << ImplIvar->getIdentifier();
2187  Diag(ClsIvar->getBitWidth()->getBeginLoc(),
2188  diag::note_previous_definition);
2189  }
2190  // Make sure the names are identical.
2191  if (ImplIvar->getIdentifier() != ClsIvar->getIdentifier()) {
2192  Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_name)
2193  << ImplIvar->getIdentifier() << ClsIvar->getIdentifier();
2194  Diag(ClsIvar->getLocation(), diag::note_previous_definition);
2195  }
2196  --numIvars;
2197  }
2198 
2199  if (numIvars > 0)
2200  Diag(ivars[j]->getLocation(), diag::err_inconsistent_ivar_count);
2201  else if (IVI != IVE)
2202  Diag(IVI->getLocation(), diag::err_inconsistent_ivar_count);
2203 }
2204 
2205 static void WarnUndefinedMethod(Sema &S, SourceLocation ImpLoc,
2206  ObjCMethodDecl *method,
2207  bool &IncompleteImpl,
2208  unsigned DiagID,
2209  NamedDecl *NeededFor = nullptr) {
2210  // No point warning no definition of method which is 'unavailable'.
2211  if (method->getAvailability() == AR_Unavailable)
2212  return;
2213 
2214  // FIXME: For now ignore 'IncompleteImpl'.
2215  // Previously we grouped all unimplemented methods under a single
2216  // warning, but some users strongly voiced that they would prefer
2217  // separate warnings. We will give that approach a try, as that
2218  // matches what we do with protocols.
2219  {
2220  const Sema::SemaDiagnosticBuilder &B = S.Diag(ImpLoc, DiagID);
2221  B << method;
2222  if (NeededFor)
2223  B << NeededFor;
2224  }
2225 
2226  // Issue a note to the original declaration.
2227  SourceLocation MethodLoc = method->getBeginLoc();
2228  if (MethodLoc.isValid())
2229  S.Diag(MethodLoc, diag::note_method_declared_at) << method;
2230 }
2231 
2232 /// Determines if type B can be substituted for type A. Returns true if we can
2233 /// guarantee that anything that the user will do to an object of type A can
2234 /// also be done to an object of type B. This is trivially true if the two
2235 /// types are the same, or if B is a subclass of A. It becomes more complex
2236 /// in cases where protocols are involved.
2237 ///
2238 /// Object types in Objective-C describe the minimum requirements for an
2239 /// object, rather than providing a complete description of a type. For
2240 /// example, if A is a subclass of B, then B* may refer to an instance of A.
2241 /// The principle of substitutability means that we may use an instance of A
2242 /// anywhere that we may use an instance of B - it will implement all of the
2243 /// ivars of B and all of the methods of B.
2244 ///
2245 /// This substitutability is important when type checking methods, because
2246 /// the implementation may have stricter type definitions than the interface.
2247 /// The interface specifies minimum requirements, but the implementation may
2248 /// have more accurate ones. For example, a method may privately accept
2249 /// instances of B, but only publish that it accepts instances of A. Any
2250 /// object passed to it will be type checked against B, and so will implicitly
2251 /// by a valid A*. Similarly, a method may return a subclass of the class that
2252 /// it is declared as returning.
2253 ///
2254 /// This is most important when considering subclassing. A method in a
2255 /// subclass must accept any object as an argument that its superclass's
2256 /// implementation accepts. It may, however, accept a more general type
2257 /// without breaking substitutability (i.e. you can still use the subclass
2258 /// anywhere that you can use the superclass, but not vice versa). The
2259 /// converse requirement applies to return types: the return type for a
2260 /// subclass method must be a valid object of the kind that the superclass
2261 /// advertises, but it may be specified more accurately. This avoids the need
2262 /// for explicit down-casting by callers.
2263 ///
2264 /// Note: This is a stricter requirement than for assignment.
2266  const ObjCObjectPointerType *A,
2267  const ObjCObjectPointerType *B,
2268  bool rejectId) {
2269  // Reject a protocol-unqualified id.
2270  if (rejectId && B->isObjCIdType()) return false;
2271 
2272  // If B is a qualified id, then A must also be a qualified id and it must
2273  // implement all of the protocols in B. It may not be a qualified class.
2274  // For example, MyClass<A> can be assigned to id<A>, but MyClass<A> is a
2275  // stricter definition so it is not substitutable for id<A>.
2276  if (B->isObjCQualifiedIdType()) {
2277  return A->isObjCQualifiedIdType() &&
2278  Context.ObjCQualifiedIdTypesAreCompatible(A, B, false);
2279  }
2280 
2281  /*
2282  // id is a special type that bypasses type checking completely. We want a
2283  // warning when it is used in one place but not another.
2284  if (C.isObjCIdType(A) || C.isObjCIdType(B)) return false;
2285 
2286 
2287  // If B is a qualified id, then A must also be a qualified id (which it isn't
2288  // if we've got this far)
2289  if (B->isObjCQualifiedIdType()) return false;
2290  */
2291 
2292  // Now we know that A and B are (potentially-qualified) class types. The
2293  // normal rules for assignment apply.
2294  return Context.canAssignObjCInterfaces(A, B);
2295 }
2296 
2298  return (TSI ? TSI->getTypeLoc().getSourceRange() : SourceRange());
2299 }
2300 
2301 /// Determine whether two set of Objective-C declaration qualifiers conflict.
2304  return (x & ~Decl::OBJC_TQ_CSNullability) !=
2305  (y & ~Decl::OBJC_TQ_CSNullability);
2306 }
2307 
2309  ObjCMethodDecl *MethodImpl,
2310  ObjCMethodDecl *MethodDecl,
2311  bool IsProtocolMethodDecl,
2312  bool IsOverridingMode,
2313  bool Warn) {
2314  if (IsProtocolMethodDecl &&
2316  MethodImpl->getObjCDeclQualifier())) {
2317  if (Warn) {
2318  S.Diag(MethodImpl->getLocation(),
2319  (IsOverridingMode
2320  ? diag::warn_conflicting_overriding_ret_type_modifiers
2321  : diag::warn_conflicting_ret_type_modifiers))
2322  << MethodImpl->getDeclName()
2323  << MethodImpl->getReturnTypeSourceRange();
2324  S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration)
2325  << MethodDecl->getReturnTypeSourceRange();
2326  }
2327  else
2328  return false;
2329  }
2330  if (Warn && IsOverridingMode &&
2331  !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
2333  MethodDecl->getReturnType(),
2334  false)) {
2335  auto nullabilityMethodImpl =
2336  *MethodImpl->getReturnType()->getNullability(S.Context);
2337  auto nullabilityMethodDecl =
2338  *MethodDecl->getReturnType()->getNullability(S.Context);
2339  S.Diag(MethodImpl->getLocation(),
2340  diag::warn_conflicting_nullability_attr_overriding_ret_types)
2342  nullabilityMethodImpl,
2344  != 0))
2346  nullabilityMethodDecl,
2348  != 0));
2349  S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
2350  }
2351 
2352  if (S.Context.hasSameUnqualifiedType(MethodImpl->getReturnType(),
2353  MethodDecl->getReturnType()))
2354  return true;
2355  if (!Warn)
2356  return false;
2357 
2358  unsigned DiagID =
2359  IsOverridingMode ? diag::warn_conflicting_overriding_ret_types
2360  : diag::warn_conflicting_ret_types;
2361 
2362  // Mismatches between ObjC pointers go into a different warning
2363  // category, and sometimes they're even completely explicitly allowed.
2364  if (const ObjCObjectPointerType *ImplPtrTy =
2365  MethodImpl->getReturnType()->getAs<ObjCObjectPointerType>()) {
2366  if (const ObjCObjectPointerType *IfacePtrTy =
2367  MethodDecl->getReturnType()->getAs<ObjCObjectPointerType>()) {
2368  // Allow non-matching return types as long as they don't violate
2369  // the principle of substitutability. Specifically, we permit
2370  // return types that are subclasses of the declared return type,
2371  // or that are more-qualified versions of the declared type.
2372  if (isObjCTypeSubstitutable(S.Context, IfacePtrTy, ImplPtrTy, false))
2373  return false;
2374 
2375  DiagID =
2376  IsOverridingMode ? diag::warn_non_covariant_overriding_ret_types
2377  : diag::warn_non_covariant_ret_types;
2378  }
2379  }
2380 
2381  S.Diag(MethodImpl->getLocation(), DiagID)
2382  << MethodImpl->getDeclName() << MethodDecl->getReturnType()
2383  << MethodImpl->getReturnType()
2384  << MethodImpl->getReturnTypeSourceRange();
2385  S.Diag(MethodDecl->getLocation(), IsOverridingMode
2386  ? diag::note_previous_declaration
2387  : diag::note_previous_definition)
2388  << MethodDecl->getReturnTypeSourceRange();
2389  return false;
2390 }
2391 
2393  ObjCMethodDecl *MethodImpl,
2394  ObjCMethodDecl *MethodDecl,
2395  ParmVarDecl *ImplVar,
2396  ParmVarDecl *IfaceVar,
2397  bool IsProtocolMethodDecl,
2398  bool IsOverridingMode,
2399  bool Warn) {
2400  if (IsProtocolMethodDecl &&
2402  IfaceVar->getObjCDeclQualifier())) {
2403  if (Warn) {
2404  if (IsOverridingMode)
2405  S.Diag(ImplVar->getLocation(),
2406  diag::warn_conflicting_overriding_param_modifiers)
2407  << getTypeRange(ImplVar->getTypeSourceInfo())
2408  << MethodImpl->getDeclName();
2409  else S.Diag(ImplVar->getLocation(),
2410  diag::warn_conflicting_param_modifiers)
2411  << getTypeRange(ImplVar->getTypeSourceInfo())
2412  << MethodImpl->getDeclName();
2413  S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration)
2414  << getTypeRange(IfaceVar->getTypeSourceInfo());
2415  }
2416  else
2417  return false;
2418  }
2419 
2420  QualType ImplTy = ImplVar->getType();
2421  QualType IfaceTy = IfaceVar->getType();
2422  if (Warn && IsOverridingMode &&
2423  !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) &&
2424  !S.Context.hasSameNullabilityTypeQualifier(ImplTy, IfaceTy, true)) {
2425  S.Diag(ImplVar->getLocation(),
2426  diag::warn_conflicting_nullability_attr_overriding_param_types)
2428  *ImplTy->getNullability(S.Context),
2430  != 0))
2432  *IfaceTy->getNullability(S.Context),
2434  != 0));
2435  S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration);
2436  }
2437  if (S.Context.hasSameUnqualifiedType(ImplTy, IfaceTy))
2438  return true;
2439 
2440  if (!Warn)
2441  return false;
2442  unsigned DiagID =
2443  IsOverridingMode ? diag::warn_conflicting_overriding_param_types
2444  : diag::warn_conflicting_param_types;
2445 
2446  // Mismatches between ObjC pointers go into a different warning
2447  // category, and sometimes they're even completely explicitly allowed..
2448  if (const ObjCObjectPointerType *ImplPtrTy =
2449  ImplTy->getAs<ObjCObjectPointerType>()) {
2450  if (const ObjCObjectPointerType *IfacePtrTy =
2451  IfaceTy->getAs<ObjCObjectPointerType>()) {
2452  // Allow non-matching argument types as long as they don't
2453  // violate the principle of substitutability. Specifically, the
2454  // implementation must accept any objects that the superclass
2455  // accepts, however it may also accept others.
2456  if (isObjCTypeSubstitutable(S.Context, ImplPtrTy, IfacePtrTy, true))
2457  return false;
2458 
2459  DiagID =
2460  IsOverridingMode ? diag::warn_non_contravariant_overriding_param_types
2461  : diag::warn_non_contravariant_param_types;
2462  }
2463  }
2464 
2465  S.Diag(ImplVar->getLocation(), DiagID)
2466  << getTypeRange(ImplVar->getTypeSourceInfo())
2467  << MethodImpl->getDeclName() << IfaceTy << ImplTy;
2468  S.Diag(IfaceVar->getLocation(),
2469  (IsOverridingMode ? diag::note_previous_declaration
2470  : diag::note_previous_definition))
2471  << getTypeRange(IfaceVar->getTypeSourceInfo());
2472  return false;
2473 }
2474 
2475 /// In ARC, check whether the conventional meanings of the two methods
2476 /// match. If they don't, it's a hard error.
2478  ObjCMethodDecl *decl) {
2479  ObjCMethodFamily implFamily = impl->getMethodFamily();
2480  ObjCMethodFamily declFamily = decl->getMethodFamily();
2481  if (implFamily == declFamily) return false;
2482 
2483  // Since conventions are sorted by selector, the only possibility is
2484  // that the types differ enough to cause one selector or the other
2485  // to fall out of the family.
2486  assert(implFamily == OMF_None || declFamily == OMF_None);
2487 
2488  // No further diagnostics required on invalid declarations.
2489  if (impl->isInvalidDecl() || decl->isInvalidDecl()) return true;
2490 
2491  const ObjCMethodDecl *unmatched = impl;
2492  ObjCMethodFamily family = declFamily;
2493  unsigned errorID = diag::err_arc_lost_method_convention;
2494  unsigned noteID = diag::note_arc_lost_method_convention;
2495  if (declFamily == OMF_None) {
2496  unmatched = decl;
2497  family = implFamily;
2498  errorID = diag::err_arc_gained_method_convention;
2499  noteID = diag::note_arc_gained_method_convention;
2500  }
2501 
2502  // Indexes into a %select clause in the diagnostic.
2503  enum FamilySelector {
2504  F_alloc, F_copy, F_mutableCopy = F_copy, F_init, F_new
2505  };
2506  FamilySelector familySelector = FamilySelector();
2507 
2508  switch (family) {
2509  case OMF_None: llvm_unreachable("logic error, no method convention");
2510  case OMF_retain:
2511  case OMF_release:
2512  case OMF_autorelease:
2513  case OMF_dealloc:
2514  case OMF_finalize:
2515  case OMF_retainCount:
2516  case OMF_self:
2517  case OMF_initialize:
2518  case OMF_performSelector:
2519  // Mismatches for these methods don't change ownership
2520  // conventions, so we don't care.
2521  return false;
2522 
2523  case OMF_init: familySelector = F_init; break;
2524  case OMF_alloc: familySelector = F_alloc; break;
2525  case OMF_copy: familySelector = F_copy; break;
2526  case OMF_mutableCopy: familySelector = F_mutableCopy; break;
2527  case OMF_new: familySelector = F_new; break;
2528  }
2529 
2530  enum ReasonSelector { R_NonObjectReturn, R_UnrelatedReturn };
2531  ReasonSelector reasonSelector;
2532 
2533  // The only reason these methods don't fall within their families is
2534  // due to unusual result types.
2535  if (unmatched->getReturnType()->isObjCObjectPointerType()) {
2536  reasonSelector = R_UnrelatedReturn;
2537  } else {
2538  reasonSelector = R_NonObjectReturn;
2539  }
2540 
2541  S.Diag(impl->getLocation(), errorID) << int(familySelector) << int(reasonSelector);
2542  S.Diag(decl->getLocation(), noteID) << int(familySelector) << int(reasonSelector);
2543 
2544  return true;
2545 }
2546 
2548  ObjCMethodDecl *MethodDecl,
2549  bool IsProtocolMethodDecl) {
2550  if (getLangOpts().ObjCAutoRefCount &&
2551  checkMethodFamilyMismatch(*this, ImpMethodDecl, MethodDecl))
2552  return;
2553 
2554  CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
2555  IsProtocolMethodDecl, false,
2556  true);
2557 
2558  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
2559  IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
2560  EF = MethodDecl->param_end();
2561  IM != EM && IF != EF; ++IM, ++IF) {
2562  CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, *IM, *IF,
2563  IsProtocolMethodDecl, false, true);
2564  }
2565 
2566  if (ImpMethodDecl->isVariadic() != MethodDecl->isVariadic()) {
2567  Diag(ImpMethodDecl->getLocation(),
2568  diag::warn_conflicting_variadic);
2569  Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
2570  }
2571 }
2572 
2574  ObjCMethodDecl *Overridden,
2575  bool IsProtocolMethodDecl) {
2576 
2577  CheckMethodOverrideReturn(*this, Method, Overridden,
2578  IsProtocolMethodDecl, true,
2579  true);
2580 
2581  for (ObjCMethodDecl::param_iterator IM = Method->param_begin(),
2582  IF = Overridden->param_begin(), EM = Method->param_end(),
2583  EF = Overridden->param_end();
2584  IM != EM && IF != EF; ++IM, ++IF) {
2585  CheckMethodOverrideParam(*this, Method, Overridden, *IM, *IF,
2586  IsProtocolMethodDecl, true, true);
2587  }
2588 
2589  if (Method->isVariadic() != Overridden->isVariadic()) {
2590  Diag(Method->getLocation(),
2591  diag::warn_conflicting_overriding_variadic);
2592  Diag(Overridden->getLocation(), diag::note_previous_declaration);
2593  }
2594 }
2595 
2596 /// WarnExactTypedMethods - This routine issues a warning if method
2597 /// implementation declaration matches exactly that of its declaration.
2599  ObjCMethodDecl *MethodDecl,
2600  bool IsProtocolMethodDecl) {
2601  // don't issue warning when protocol method is optional because primary
2602  // class is not required to implement it and it is safe for protocol
2603  // to implement it.
2605  return;
2606  // don't issue warning when primary class's method is
2607  // depecated/unavailable.
2608  if (MethodDecl->hasAttr<UnavailableAttr>() ||
2609  MethodDecl->hasAttr<DeprecatedAttr>())
2610  return;
2611 
2612  bool match = CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
2613  IsProtocolMethodDecl, false, false);
2614  if (match)
2615  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
2616  IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
2617  EF = MethodDecl->param_end();
2618  IM != EM && IF != EF; ++IM, ++IF) {
2619  match = CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl,
2620  *IM, *IF,
2621  IsProtocolMethodDecl, false, false);
2622  if (!match)
2623  break;
2624  }
2625  if (match)
2626  match = (ImpMethodDecl->isVariadic() == MethodDecl->isVariadic());
2627  if (match)
2628  match = !(MethodDecl->isClassMethod() &&
2629  MethodDecl->getSelector() == GetNullarySelector("load", Context));
2630 
2631  if (match) {
2632  Diag(ImpMethodDecl->getLocation(),
2633  diag::warn_category_method_impl_match);
2634  Diag(MethodDecl->getLocation(), diag::note_method_declared_at)
2635  << MethodDecl->getDeclName();
2636  }
2637 }
2638 
2639 /// FIXME: Type hierarchies in Objective-C can be deep. We could most likely
2640 /// improve the efficiency of selector lookups and type checking by associating
2641 /// with each protocol / interface / category the flattened instance tables. If
2642 /// we used an immutable set to keep the table then it wouldn't add significant
2643 /// memory cost and it would be handy for lookups.
2644 
2646 typedef std::unique_ptr<ProtocolNameSet> LazyProtocolNameSet;
2647 
2649  ProtocolNameSet &PNS) {
2650  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2651  PNS.insert(PDecl->getIdentifier());
2652  for (const auto *PI : PDecl->protocols())
2654 }
2655 
2656 /// Recursively populates a set with all conformed protocols in a class
2657 /// hierarchy that have the 'objc_protocol_requires_explicit_implementation'
2658 /// attribute.
2660  ProtocolNameSet &PNS) {
2661  if (!Super)
2662  return;
2663 
2664  for (const auto *I : Super->all_referenced_protocols())
2666 
2668 }
2669 
2670 /// CheckProtocolMethodDefs - This routine checks unimplemented methods
2671 /// Declared in protocol, and those referenced by it.
2673  SourceLocation ImpLoc,
2674  ObjCProtocolDecl *PDecl,
2675  bool& IncompleteImpl,
2676  const Sema::SelectorSet &InsMap,
2677  const Sema::SelectorSet &ClsMap,
2678  ObjCContainerDecl *CDecl,
2679  LazyProtocolNameSet &ProtocolsExplictImpl) {
2680  ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
2681  ObjCInterfaceDecl *IDecl = C ? C->getClassInterface()
2682  : dyn_cast<ObjCInterfaceDecl>(CDecl);
2683  assert (IDecl && "CheckProtocolMethodDefs - IDecl is null");
2684 
2685  ObjCInterfaceDecl *Super = IDecl->getSuperClass();
2686  ObjCInterfaceDecl *NSIDecl = nullptr;
2687 
2688  // If this protocol is marked 'objc_protocol_requires_explicit_implementation'
2689  // then we should check if any class in the super class hierarchy also
2690  // conforms to this protocol, either directly or via protocol inheritance.
2691  // If so, we can skip checking this protocol completely because we
2692  // know that a parent class already satisfies this protocol.
2693  //
2694  // Note: we could generalize this logic for all protocols, and merely
2695  // add the limit on looking at the super class chain for just
2696  // specially marked protocols. This may be a good optimization. This
2697  // change is restricted to 'objc_protocol_requires_explicit_implementation'
2698  // protocols for now for controlled evaluation.
2699  if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>()) {
2700  if (!ProtocolsExplictImpl) {
2701  ProtocolsExplictImpl.reset(new ProtocolNameSet);
2702  findProtocolsWithExplicitImpls(Super, *ProtocolsExplictImpl);
2703  }
2704  if (ProtocolsExplictImpl->find(PDecl->getIdentifier()) !=
2705  ProtocolsExplictImpl->end())
2706  return;
2707 
2708  // If no super class conforms to the protocol, we should not search
2709  // for methods in the super class to implicitly satisfy the protocol.
2710  Super = nullptr;
2711  }
2712 
2713  if (S.getLangOpts().ObjCRuntime.isNeXTFamily()) {
2714  // check to see if class implements forwardInvocation method and objects
2715  // of this class are derived from 'NSProxy' so that to forward requests
2716  // from one object to another.
2717  // Under such conditions, which means that every method possible is
2718  // implemented in the class, we should not issue "Method definition not
2719  // found" warnings.
2720  // FIXME: Use a general GetUnarySelector method for this.
2721  IdentifierInfo* II = &S.Context.Idents.get("forwardInvocation");
2722  Selector fISelector = S.Context.Selectors.getSelector(1, &II);
2723  if (InsMap.count(fISelector))
2724  // Is IDecl derived from 'NSProxy'? If so, no instance methods
2725  // need be implemented in the implementation.
2726  NSIDecl = IDecl->lookupInheritedClass(&S.Context.Idents.get("NSProxy"));
2727  }
2728 
2729  // If this is a forward protocol declaration, get its definition.
2730  if (!PDecl->isThisDeclarationADefinition() &&
2731  PDecl->getDefinition())
2732  PDecl = PDecl->getDefinition();
2733 
2734  // If a method lookup fails locally we still need to look and see if
2735  // the method was implemented by a base class or an inherited
2736  // protocol. This lookup is slow, but occurs rarely in correct code
2737  // and otherwise would terminate in a warning.
2738 
2739  // check unimplemented instance methods.
2740  if (!NSIDecl)
2741  for (auto *method : PDecl->instance_methods()) {
2742  if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
2743  !method->isPropertyAccessor() &&
2744  !InsMap.count(method->getSelector()) &&
2745  (!Super || !Super->lookupMethod(method->getSelector(),
2746  true /* instance */,
2747  false /* shallowCategory */,
2748  true /* followsSuper */,
2749  nullptr /* category */))) {
2750  // If a method is not implemented in the category implementation but
2751  // has been declared in its primary class, superclass,
2752  // or in one of their protocols, no need to issue the warning.
2753  // This is because method will be implemented in the primary class
2754  // or one of its super class implementation.
2755 
2756  // Ugly, but necessary. Method declared in protocol might have
2757  // have been synthesized due to a property declared in the class which
2758  // uses the protocol.
2759  if (ObjCMethodDecl *MethodInClass =
2760  IDecl->lookupMethod(method->getSelector(),
2761  true /* instance */,
2762  true /* shallowCategoryLookup */,
2763  false /* followSuper */))
2764  if (C || MethodInClass->isPropertyAccessor())
2765  continue;
2766  unsigned DIAG = diag::warn_unimplemented_protocol_method;
2767  if (!S.Diags.isIgnored(DIAG, ImpLoc)) {
2768  WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG,
2769  PDecl);
2770  }
2771  }
2772  }
2773  // check unimplemented class methods
2774  for (auto *method : PDecl->class_methods()) {
2775  if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
2776  !ClsMap.count(method->getSelector()) &&
2777  (!Super || !Super->lookupMethod(method->getSelector(),
2778  false /* class method */,
2779  false /* shallowCategoryLookup */,
2780  true /* followSuper */,
2781  nullptr /* category */))) {
2782  // See above comment for instance method lookups.
2783  if (C && IDecl->lookupMethod(method->getSelector(),
2784  false /* class */,
2785  true /* shallowCategoryLookup */,
2786  false /* followSuper */))
2787  continue;
2788 
2789  unsigned DIAG = diag::warn_unimplemented_protocol_method;
2790  if (!S.Diags.isIgnored(DIAG, ImpLoc)) {
2791  WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG, PDecl);
2792  }
2793  }
2794  }
2795  // Check on this protocols's referenced protocols, recursively.
2796  for (auto *PI : PDecl->protocols())
2797  CheckProtocolMethodDefs(S, ImpLoc, PI, IncompleteImpl, InsMap, ClsMap,
2798  CDecl, ProtocolsExplictImpl);
2799 }
2800 
2801 /// MatchAllMethodDeclarations - Check methods declared in interface
2802 /// or protocol against those declared in their implementations.
2803 ///
2805  const SelectorSet &ClsMap,
2806  SelectorSet &InsMapSeen,
2807  SelectorSet &ClsMapSeen,
2808  ObjCImplDecl* IMPDecl,
2809  ObjCContainerDecl* CDecl,
2810  bool &IncompleteImpl,
2811  bool ImmediateClass,
2812  bool WarnCategoryMethodImpl) {
2813  // Check and see if instance methods in class interface have been
2814  // implemented in the implementation class. If so, their types match.
2815  for (auto *I : CDecl->instance_methods()) {
2816  if (!InsMapSeen.insert(I->getSelector()).second)
2817  continue;
2818  if (!I->isPropertyAccessor() &&
2819  !InsMap.count(I->getSelector())) {
2820  if (ImmediateClass)
2821  WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl,
2822  diag::warn_undef_method_impl);
2823  continue;
2824  } else {
2825  ObjCMethodDecl *ImpMethodDecl =
2826  IMPDecl->getInstanceMethod(I->getSelector());
2827  assert(CDecl->getInstanceMethod(I->getSelector(), true/*AllowHidden*/) &&
2828  "Expected to find the method through lookup as well");
2829  // ImpMethodDecl may be null as in a @dynamic property.
2830  if (ImpMethodDecl) {
2831  // Skip property accessor function stubs.
2832  if (ImpMethodDecl->isSynthesizedAccessorStub())
2833  continue;
2834  if (!WarnCategoryMethodImpl)
2835  WarnConflictingTypedMethods(ImpMethodDecl, I,
2836  isa<ObjCProtocolDecl>(CDecl));
2837  else if (!I->isPropertyAccessor())
2838  WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
2839  }
2840  }
2841  }
2842 
2843  // Check and see if class methods in class interface have been
2844  // implemented in the implementation class. If so, their types match.
2845  for (auto *I : CDecl->class_methods()) {
2846  if (!ClsMapSeen.insert(I->getSelector()).second)
2847  continue;
2848  if (!I->isPropertyAccessor() &&
2849  !ClsMap.count(I->getSelector())) {
2850  if (ImmediateClass)
2851  WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl,
2852  diag::warn_undef_method_impl);
2853  } else {
2854  ObjCMethodDecl *ImpMethodDecl =
2855  IMPDecl->getClassMethod(I->getSelector());
2856  assert(CDecl->getClassMethod(I->getSelector(), true/*AllowHidden*/) &&
2857  "Expected to find the method through lookup as well");
2858  // ImpMethodDecl may be null as in a @dynamic property.
2859  if (ImpMethodDecl) {
2860  // Skip property accessor function stubs.
2861  if (ImpMethodDecl->isSynthesizedAccessorStub())
2862  continue;
2863  if (!WarnCategoryMethodImpl)
2864  WarnConflictingTypedMethods(ImpMethodDecl, I,
2865  isa<ObjCProtocolDecl>(CDecl));
2866  else if (!I->isPropertyAccessor())
2867  WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl));
2868  }
2869  }
2870  }
2871 
2872  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl> (CDecl)) {
2873  // Also, check for methods declared in protocols inherited by
2874  // this protocol.
2875  for (auto *PI : PD->protocols())
2876  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2877  IMPDecl, PI, IncompleteImpl, false,
2878  WarnCategoryMethodImpl);
2879  }
2880 
2881  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
2882  // when checking that methods in implementation match their declaration,
2883  // i.e. when WarnCategoryMethodImpl is false, check declarations in class
2884  // extension; as well as those in categories.
2885  if (!WarnCategoryMethodImpl) {
2886  for (auto *Cat : I->visible_categories())
2887  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2888  IMPDecl, Cat, IncompleteImpl,
2889  ImmediateClass && Cat->IsClassExtension(),
2890  WarnCategoryMethodImpl);
2891  } else {
2892  // Also methods in class extensions need be looked at next.
2893  for (auto *Ext : I->visible_extensions())
2894  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2895  IMPDecl, Ext, IncompleteImpl, false,
2896  WarnCategoryMethodImpl);
2897  }
2898 
2899  // Check for any implementation of a methods declared in protocol.
2900  for (auto *PI : I->all_referenced_protocols())
2901  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2902  IMPDecl, PI, IncompleteImpl, false,
2903  WarnCategoryMethodImpl);
2904 
2905  // FIXME. For now, we are not checking for exact match of methods
2906  // in category implementation and its primary class's super class.
2907  if (!WarnCategoryMethodImpl && I->getSuperClass())
2908  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2909  IMPDecl,
2910  I->getSuperClass(), IncompleteImpl, false);
2911  }
2912 }
2913 
2914 /// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
2915 /// category matches with those implemented in its primary class and
2916 /// warns each time an exact match is found.
2918  ObjCCategoryImplDecl *CatIMPDecl) {
2919  // Get category's primary class.
2920  ObjCCategoryDecl *CatDecl = CatIMPDecl->getCategoryDecl();
2921  if (!CatDecl)
2922  return;
2923  ObjCInterfaceDecl *IDecl = CatDecl->getClassInterface();
2924  if (!IDecl)
2925  return;
2926  ObjCInterfaceDecl *SuperIDecl = IDecl->getSuperClass();
2927  SelectorSet InsMap, ClsMap;
2928 
2929  for (const auto *I : CatIMPDecl->instance_methods()) {
2930  Selector Sel = I->getSelector();
2931  // When checking for methods implemented in the category, skip over
2932  // those declared in category class's super class. This is because
2933  // the super class must implement the method.
2934  if (SuperIDecl && SuperIDecl->lookupMethod(Sel, true))
2935  continue;
2936  InsMap.insert(Sel);
2937  }
2938 
2939  for (const auto *I : CatIMPDecl->class_methods()) {
2940  Selector Sel = I->getSelector();
2941  if (SuperIDecl && SuperIDecl->lookupMethod(Sel, false))
2942  continue;
2943  ClsMap.insert(Sel);
2944  }
2945  if (InsMap.empty() && ClsMap.empty())
2946  return;
2947 
2948  SelectorSet InsMapSeen, ClsMapSeen;
2949  bool IncompleteImpl = false;
2950  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
2951  CatIMPDecl, IDecl,
2952  IncompleteImpl, false,
2953  true /*WarnCategoryMethodImpl*/);
2954 }
2955 
2957  ObjCContainerDecl* CDecl,
2958  bool IncompleteImpl) {
2959  SelectorSet InsMap;
2960  // Check and see if instance methods in class interface have been
2961  // implemented in the implementation class.
2962  for (const auto *I : IMPDecl->instance_methods())
2963  InsMap.insert(I->getSelector());
2964 
2965  // Add the selectors for getters/setters of @dynamic properties.
2966  for (const auto *PImpl : IMPDecl->property_impls()) {
2967  // We only care about @dynamic implementations.
2968  if (PImpl->getPropertyImplementation() != ObjCPropertyImplDecl::Dynamic)
2969  continue;
2970 
2971  const auto *P = PImpl->getPropertyDecl();
2972  if (!P) continue;
2973 
2974  InsMap.insert(P->getGetterName());
2975  if (!P->getSetterName().isNull())
2976  InsMap.insert(P->getSetterName());
2977  }
2978 
2979  // Check and see if properties declared in the interface have either 1)
2980  // an implementation or 2) there is a @synthesize/@dynamic implementation
2981  // of the property in the @implementation.
2982  if (const ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
2983  bool SynthesizeProperties = LangOpts.ObjCDefaultSynthProperties &&
2985  !IDecl->isObjCRequiresPropertyDefs();
2986  DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, SynthesizeProperties);
2987  }
2988 
2989  // Diagnose null-resettable synthesized setters.
2991 
2992  SelectorSet ClsMap;
2993  for (const auto *I : IMPDecl->class_methods())
2994  ClsMap.insert(I->getSelector());
2995 
2996  // Check for type conflict of methods declared in a class/protocol and
2997  // its implementation; if any.
2998  SelectorSet InsMapSeen, ClsMapSeen;
2999  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
3000  IMPDecl, CDecl,
3001  IncompleteImpl, true);
3002 
3003  // check all methods implemented in category against those declared
3004  // in its primary class.
3005  if (ObjCCategoryImplDecl *CatDecl =
3006  dyn_cast<ObjCCategoryImplDecl>(IMPDecl))
3008 
3009  // Check the protocol list for unimplemented methods in the @implementation
3010  // class.
3011  // Check and see if class methods in class interface have been
3012  // implemented in the implementation class.
3013 
3014  LazyProtocolNameSet ExplicitImplProtocols;
3015 
3016  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
3017  for (auto *PI : I->all_referenced_protocols())
3018  CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), PI, IncompleteImpl,
3019  InsMap, ClsMap, I, ExplicitImplProtocols);
3020  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
3021  // For extended class, unimplemented methods in its protocols will
3022  // be reported in the primary class.
3023  if (!C->IsClassExtension()) {
3024  for (auto *P : C->protocols())
3025  CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), P,
3026  IncompleteImpl, InsMap, ClsMap, CDecl,
3027  ExplicitImplProtocols);
3028  DiagnoseUnimplementedProperties(S, IMPDecl, CDecl,
3029  /*SynthesizeProperties=*/false);
3030  }
3031  } else
3032  llvm_unreachable("invalid ObjCContainerDecl type.");
3033 }
3034 
3037  IdentifierInfo **IdentList,
3038  SourceLocation *IdentLocs,
3039  ArrayRef<ObjCTypeParamList *> TypeParamLists,
3040  unsigned NumElts) {
3041  SmallVector<Decl *, 8> DeclsInGroup;
3042  for (unsigned i = 0; i != NumElts; ++i) {
3043  // Check for another declaration kind with the same name.
3044  NamedDecl *PrevDecl
3045  = LookupSingleName(TUScope, IdentList[i], IdentLocs[i],
3047  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
3048  // GCC apparently allows the following idiom:
3049  //
3050  // typedef NSObject < XCElementTogglerP > XCElementToggler;
3051  // @class XCElementToggler;
3052  //
3053  // Here we have chosen to ignore the forward class declaration
3054  // with a warning. Since this is the implied behavior.
3055  TypedefNameDecl *TDD = dyn_cast<TypedefNameDecl>(PrevDecl);
3056  if (!TDD || !TDD->getUnderlyingType()->isObjCObjectType()) {
3057  Diag(AtClassLoc, diag::err_redefinition_different_kind) << IdentList[i];
3058  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3059  } else {
3060  // a forward class declaration matching a typedef name of a class refers
3061  // to the underlying class. Just ignore the forward class with a warning
3062  // as this will force the intended behavior which is to lookup the
3063  // typedef name.
3064  if (isa<ObjCObjectType>(TDD->getUnderlyingType())) {
3065  Diag(AtClassLoc, diag::warn_forward_class_redefinition)
3066  << IdentList[i];
3067  Diag(PrevDecl->getLocation(), diag::note_previous_definition);
3068  continue;
3069  }
3070  }
3071  }
3072 
3073  // Create a declaration to describe this forward declaration.
3074  ObjCInterfaceDecl *PrevIDecl
3075  = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
3076 
3077  IdentifierInfo *ClassName = IdentList[i];
3078  if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) {
3079  // A previous decl with a different name is because of
3080  // @compatibility_alias, for example:
3081  // \code
3082  // @class NewImage;
3083  // @compatibility_alias OldImage NewImage;
3084  // \endcode
3085  // A lookup for 'OldImage' will return the 'NewImage' decl.
3086  //
3087  // In such a case use the real declaration name, instead of the alias one,
3088  // otherwise we will break IdentifierResolver and redecls-chain invariants.
3089  // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl
3090  // has been aliased.
3091  ClassName = PrevIDecl->getIdentifier();
3092  }
3093 
3094  // If this forward declaration has type parameters, compare them with the
3095  // type parameters of the previous declaration.
3096  ObjCTypeParamList *TypeParams = TypeParamLists[i];
3097  if (PrevIDecl && TypeParams) {
3098  if (ObjCTypeParamList *PrevTypeParams = PrevIDecl->getTypeParamList()) {
3099  // Check for consistency with the previous declaration.
3101  *this, PrevTypeParams, TypeParams,
3102  TypeParamListContext::ForwardDeclaration)) {
3103  TypeParams = nullptr;
3104  }
3105  } else if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
3106  // The @interface does not have type parameters. Complain.
3107  Diag(IdentLocs[i], diag::err_objc_parameterized_forward_class)
3108  << ClassName
3109  << TypeParams->getSourceRange();
3110  Diag(Def->getLocation(), diag::note_defined_here)
3111  << ClassName;
3112 
3113  TypeParams = nullptr;
3114  }
3115  }
3116 
3117  ObjCInterfaceDecl *IDecl
3119  ClassName, TypeParams, PrevIDecl,
3120  IdentLocs[i]);
3121  IDecl->setAtEndRange(IdentLocs[i]);
3122 
3123  PushOnScopeChains(IDecl, TUScope);
3124  CheckObjCDeclScope(IDecl);
3125  DeclsInGroup.push_back(IDecl);
3126  }
3127 
3128  return BuildDeclaratorGroup(DeclsInGroup);
3129 }
3130 
3132  Sema::MethodMatchStrategy strategy,
3133  const Type *left, const Type *right);
3134 
3135 static bool matchTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy,
3136  QualType leftQT, QualType rightQT) {
3137  const Type *left =
3138  Context.getCanonicalType(leftQT).getUnqualifiedType().getTypePtr();
3139  const Type *right =
3140  Context.getCanonicalType(rightQT).getUnqualifiedType().getTypePtr();
3141 
3142  if (left == right) return true;
3143 
3144  // If we're doing a strict match, the types have to match exactly.
3145  if (strategy == Sema::MMS_strict) return false;
3146 
3147  if (left->isIncompleteType() || right->isIncompleteType()) return false;
3148 
3149  // Otherwise, use this absurdly complicated algorithm to try to
3150  // validate the basic, low-level compatibility of the two types.
3151 
3152  // As a minimum, require the sizes and alignments to match.
3153  TypeInfo LeftTI = Context.getTypeInfo(left);
3154  TypeInfo RightTI = Context.getTypeInfo(right);
3155  if (LeftTI.Width != RightTI.Width)
3156  return false;
3157 
3158  if (LeftTI.Align != RightTI.Align)
3159  return false;
3160 
3161  // Consider all the kinds of non-dependent canonical types:
3162  // - functions and arrays aren't possible as return and parameter types
3163 
3164  // - vector types of equal size can be arbitrarily mixed
3165  if (isa<VectorType>(left)) return isa<VectorType>(right);
3166  if (isa<VectorType>(right)) return false;
3167 
3168  // - references should only match references of identical type
3169  // - structs, unions, and Objective-C objects must match more-or-less
3170  // exactly
3171  // - everything else should be a scalar
3172  if (!left->isScalarType() || !right->isScalarType())
3173  return tryMatchRecordTypes(Context, strategy, left, right);
3174 
3175  // Make scalars agree in kind, except count bools as chars, and group
3176  // all non-member pointers together.
3177  Type::ScalarTypeKind leftSK = left->getScalarTypeKind();
3178  Type::ScalarTypeKind rightSK = right->getScalarTypeKind();
3179  if (leftSK == Type::STK_Bool) leftSK = Type::STK_Integral;
3180  if (rightSK == Type::STK_Bool) rightSK = Type::STK_Integral;
3181  if (leftSK == Type::STK_CPointer || leftSK == Type::STK_BlockPointer)
3182  leftSK = Type::STK_ObjCObjectPointer;
3183  if (rightSK == Type::STK_CPointer || rightSK == Type::STK_BlockPointer)
3184  rightSK = Type::STK_ObjCObjectPointer;
3185 
3186  // Note that data member pointers and function member pointers don't
3187  // intermix because of the size differences.
3188 
3189  return (leftSK == rightSK);
3190 }
3191 
3192 static bool tryMatchRecordTypes(ASTContext &Context,
3193  Sema::MethodMatchStrategy strategy,
3194  const Type *lt, const Type *rt) {
3195  assert(lt && rt && lt != rt);
3196 
3197  if (!isa<RecordType>(lt) || !isa<RecordType>(rt)) return false;
3198  RecordDecl *left = cast<RecordType>(lt)->getDecl();
3199  RecordDecl *right = cast<RecordType>(rt)->getDecl();
3200 
3201  // Require union-hood to match.
3202  if (left->isUnion() != right->isUnion()) return false;
3203 
3204  // Require an exact match if either is non-POD.
3205  if ((isa<CXXRecordDecl>(left) && !cast<CXXRecordDecl>(left)->isPOD()) ||
3206  (isa<CXXRecordDecl>(right) && !cast<CXXRecordDecl>(right)->isPOD()))
3207  return false;
3208 
3209  // Require size and alignment to match.
3210  TypeInfo LeftTI = Context.getTypeInfo(lt);
3211  TypeInfo RightTI = Context.getTypeInfo(rt);
3212  if (LeftTI.Width != RightTI.Width)
3213  return false;
3214 
3215  if (LeftTI.Align != RightTI.Align)
3216  return false;
3217 
3218  // Require fields to match.
3219  RecordDecl::field_iterator li = left->field_begin(), le = left->field_end();
3220  RecordDecl::field_iterator ri = right->field_begin(), re = right->field_end();
3221  for (; li != le && ri != re; ++li, ++ri) {
3222  if (!matchTypes(Context, strategy, li->getType(), ri->getType()))
3223  return false;
3224  }
3225  return (li == le && ri == re);
3226 }
3227 
3228 /// MatchTwoMethodDeclarations - Checks that two methods have matching type and
3229 /// returns true, or false, accordingly.
3230 /// TODO: Handle protocol list; such as id<p1,p2> in type comparisons
3232  const ObjCMethodDecl *right,
3233  MethodMatchStrategy strategy) {
3234  if (!matchTypes(Context, strategy, left->getReturnType(),
3235  right->getReturnType()))
3236  return false;
3237 
3238  // If either is hidden, it is not considered to match.
3239  if (!left->isUnconditionallyVisible() || !right->isUnconditionallyVisible())
3240  return false;
3241 
3242  if (left->isDirectMethod() != right->isDirectMethod())
3243  return false;
3244 
3245  if (getLangOpts().ObjCAutoRefCount &&
3246  (left->hasAttr<NSReturnsRetainedAttr>()
3247  != right->hasAttr<NSReturnsRetainedAttr>() ||
3248  left->hasAttr<NSConsumesSelfAttr>()
3249  != right->hasAttr<NSConsumesSelfAttr>()))
3250  return false;
3251 
3253  li = left->param_begin(), le = left->param_end(), ri = right->param_begin(),
3254  re = right->param_end();
3255 
3256  for (; li != le && ri != re; ++li, ++ri) {
3257  assert(ri != right->param_end() && "Param mismatch");
3258  const ParmVarDecl *lparm = *li, *rparm = *ri;
3259 
3260  if (!matchTypes(Context, strategy, lparm->getType(), rparm->getType()))
3261  return false;
3262 
3263  if (getLangOpts().ObjCAutoRefCount &&
3264  lparm->hasAttr<NSConsumedAttr>() != rparm->hasAttr<NSConsumedAttr>())
3265  return false;
3266  }
3267  return true;
3268 }
3269 
3271  ObjCMethodDecl *MethodInList) {
3272  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
3273  auto *MethodInListProtocol =
3274  dyn_cast<ObjCProtocolDecl>(MethodInList->getDeclContext());
3275  // If this method belongs to a protocol but the method in list does not, or
3276  // vice versa, we say the context is not the same.
3277  if ((MethodProtocol && !MethodInListProtocol) ||
3278  (!MethodProtocol && MethodInListProtocol))
3279  return false;
3280 
3281  if (MethodProtocol && MethodInListProtocol)
3282  return true;
3283 
3284  ObjCInterfaceDecl *MethodInterface = Method->getClassInterface();
3285  ObjCInterfaceDecl *MethodInListInterface =
3286  MethodInList->getClassInterface();
3287  return MethodInterface == MethodInListInterface;
3288 }
3289 
3291  ObjCMethodDecl *Method) {
3292  // Record at the head of the list whether there were 0, 1, or >= 2 methods
3293  // inside categories.
3294  if (ObjCCategoryDecl *CD =
3295  dyn_cast<ObjCCategoryDecl>(Method->getDeclContext()))
3296  if (!CD->IsClassExtension() && List->getBits() < 2)
3297  List->setBits(List->getBits() + 1);
3298 
3299  // If the list is empty, make it a singleton list.
3300  if (List->getMethod() == nullptr) {
3301  List->setMethod(Method);
3302  List->setNext(nullptr);
3303  return;
3304  }
3305 
3306  // We've seen a method with this name, see if we have already seen this type
3307  // signature.
3308  ObjCMethodList *Previous = List;
3309  ObjCMethodList *ListWithSameDeclaration = nullptr;
3310  for (; List; Previous = List, List = List->getNext()) {
3311  // If we are building a module, keep all of the methods.
3313  continue;
3314 
3315  bool SameDeclaration = MatchTwoMethodDeclarations(Method,
3316  List->getMethod());
3317  // Looking for method with a type bound requires the correct context exists.
3318  // We need to insert a method into the list if the context is different.
3319  // If the method's declaration matches the list
3320  // a> the method belongs to a different context: we need to insert it, in
3321  // order to emit the availability message, we need to prioritize over
3322  // availability among the methods with the same declaration.
3323  // b> the method belongs to the same context: there is no need to insert a
3324  // new entry.
3325  // If the method's declaration does not match the list, we insert it to the
3326  // end.
3327  if (!SameDeclaration ||
3328  !isMethodContextSameForKindofLookup(Method, List->getMethod())) {
3329  // Even if two method types do not match, we would like to say
3330  // there is more than one declaration so unavailability/deprecated
3331  // warning is not too noisy.
3332  if (!Method->isDefined())
3333  List->setHasMoreThanOneDecl(true);
3334 
3335  // For methods with the same declaration, the one that is deprecated
3336  // should be put in the front for better diagnostics.
3337  if (Method->isDeprecated() && SameDeclaration &&
3338  !ListWithSameDeclaration && !List->getMethod()->isDeprecated())
3339  ListWithSameDeclaration = List;
3340 
3341  if (Method->isUnavailable() && SameDeclaration &&
3342  !ListWithSameDeclaration &&
3344  ListWithSameDeclaration = List;
3345  continue;
3346  }
3347 
3348  ObjCMethodDecl *PrevObjCMethod = List->getMethod();
3349 
3350  // Propagate the 'defined' bit.
3351  if (Method->isDefined())
3352  PrevObjCMethod->setDefined(true);
3353  else {
3354  // Objective-C doesn't allow an @interface for a class after its
3355  // @implementation. So if Method is not defined and there already is
3356  // an entry for this type signature, Method has to be for a different
3357  // class than PrevObjCMethod.
3358  List->setHasMoreThanOneDecl(true);
3359  }
3360 
3361  // If a method is deprecated, push it in the global pool.
3362  // This is used for better diagnostics.
3363  if (Method->isDeprecated()) {
3364  if (!PrevObjCMethod->isDeprecated())
3365  List->setMethod(Method);
3366  }
3367  // If the new method is unavailable, push it into global pool
3368  // unless previous one is deprecated.
3369  if (Method->isUnavailable()) {
3370  if (PrevObjCMethod->getAvailability() < AR_Deprecated)
3371  List->setMethod(Method);
3372  }
3373 
3374  return;
3375  }
3376 
3377  // We have a new signature for an existing method - add it.
3378  // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
3379  ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
3380 
3381  // We insert it right before ListWithSameDeclaration.
3382  if (ListWithSameDeclaration) {
3383  auto *List = new (Mem) ObjCMethodList(*ListWithSameDeclaration);
3384  // FIXME: should we clear the other bits in ListWithSameDeclaration?
3385  ListWithSameDeclaration->setMethod(Method);
3386  ListWithSameDeclaration->setNext(List);
3387  return;
3388  }
3389 
3390  Previous->setNext(new (Mem) ObjCMethodList(Method));
3391 }
3392 
3393 /// Read the contents of the method pool for a given selector from
3394 /// external storage.
3396  assert(ExternalSource && "We need an external AST source");
3397  ExternalSource->ReadMethodPool(Sel);
3398 }
3399 
3401  if (!ExternalSource)
3402  return;
3403  ExternalSource->updateOutOfDateSelector(Sel);
3404 }
3405 
3406 void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
3407  bool instance) {
3408  // Ignore methods of invalid containers.
3409  if (cast<Decl>(Method->getDeclContext())->isInvalidDecl())
3410  return;
3411 
3412  if (ExternalSource)
3413  ReadMethodPool(Method->getSelector());
3414 
3415  GlobalMethodPool::iterator Pos = MethodPool.find(Method->getSelector());
3416  if (Pos == MethodPool.end())
3417  Pos = MethodPool.insert(std::make_pair(Method->getSelector(),
3418  GlobalMethods())).first;
3419 
3420  Method->setDefined(impl);
3421 
3422  ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second;
3423  addMethodToGlobalList(&Entry, Method);
3424 }
3425 
3426 /// Determines if this is an "acceptable" loose mismatch in the global
3427 /// method pool. This exists mostly as a hack to get around certain
3428 /// global mismatches which we can't afford to make warnings / errors.
3429 /// Really, what we want is a way to take a method out of the global
3430 /// method pool.
3432  ObjCMethodDecl *other) {
3433  if (!chosen->isInstanceMethod())
3434  return false;
3435 
3436  if (chosen->isDirectMethod() != other->isDirectMethod())
3437  return false;
3438 
3439  Selector sel = chosen->getSelector();
3440  if (!sel.isUnarySelector() || sel.getNameForSlot(0) != "length")
3441  return false;
3442 
3443  // Don't complain about mismatches for -length if the method we
3444  // chose has an integral result type.
3445  return (chosen->getReturnType()->isIntegerType());
3446 }
3447 
3448 /// Return true if the given method is wthin the type bound.
3450  const ObjCObjectType *TypeBound) {
3451  if (!TypeBound)
3452  return true;
3453 
3454  if (TypeBound->isObjCId())
3455  // FIXME: should we handle the case of bounding to id<A, B> differently?
3456  return true;
3457 
3458  auto *BoundInterface = TypeBound->getInterface();
3459  assert(BoundInterface && "unexpected object type!");
3460 
3461  // Check if the Method belongs to a protocol. We should allow any method
3462  // defined in any protocol, because any subclass could adopt the protocol.
3463  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
3464  if (MethodProtocol) {
3465  return true;
3466  }
3467 
3468  // If the Method belongs to a class, check if it belongs to the class
3469  // hierarchy of the class bound.
3470  if (ObjCInterfaceDecl *MethodInterface = Method->getClassInterface()) {
3471  // We allow methods declared within classes that are part of the hierarchy
3472  // of the class bound (superclass of, subclass of, or the same as the class
3473  // bound).
3474  return MethodInterface == BoundInterface ||
3475  MethodInterface->isSuperClassOf(BoundInterface) ||
3476  BoundInterface->isSuperClassOf(MethodInterface);
3477  }
3478  llvm_unreachable("unknown method context");
3479 }
3480 
3481 /// We first select the type of the method: Instance or Factory, then collect
3482 /// all methods with that type.
3485  bool InstanceFirst, bool CheckTheOther,
3486  const ObjCObjectType *TypeBound) {
3487  if (ExternalSource)
3488  ReadMethodPool(Sel);
3489 
3490  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
3491  if (Pos == MethodPool.end())
3492  return false;
3493 
3494  // Gather the non-hidden methods.
3495  ObjCMethodList &MethList = InstanceFirst ? Pos->second.first :
3496  Pos->second.second;
3497  for (ObjCMethodList *M = &MethList; M; M = M->getNext())
3498  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible()) {
3499  if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
3500  Methods.push_back(M->getMethod());
3501  }
3502 
3503  // Return if we find any method with the desired kind.
3504  if (!Methods.empty())
3505  return Methods.size() > 1;
3506 
3507  if (!CheckTheOther)
3508  return false;
3509 
3510  // Gather the other kind.
3511  ObjCMethodList &MethList2 = InstanceFirst ? Pos->second.second :
3512  Pos->second.first;
3513  for (ObjCMethodList *M = &MethList2; M; M = M->getNext())
3514  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible()) {
3515  if (FilterMethodsByTypeBound(M->getMethod(), TypeBound))
3516  Methods.push_back(M->getMethod());
3517  }
3518 
3519  return Methods.size() > 1;
3520 }
3521 
3523  Selector Sel, ObjCMethodDecl *BestMethod, SourceRange R,
3524  bool receiverIdOrClass, SmallVectorImpl<ObjCMethodDecl *> &Methods) {
3525  // Diagnose finding more than one method in global pool.
3526  SmallVector<ObjCMethodDecl *, 4> FilteredMethods;
3527  FilteredMethods.push_back(BestMethod);
3528 
3529  for (auto *M : Methods)
3530  if (M != BestMethod && !M->hasAttr<UnavailableAttr>())
3531  FilteredMethods.push_back(M);
3532 
3533  if (FilteredMethods.size() > 1)
3534  DiagnoseMultipleMethodInGlobalPool(FilteredMethods, Sel, R,
3535  receiverIdOrClass);
3536 
3537  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
3538  // Test for no method in the pool which should not trigger any warning by
3539  // caller.
3540  if (Pos == MethodPool.end())
3541  return true;
3542  ObjCMethodList &MethList =
3543  BestMethod->isInstanceMethod() ? Pos->second.first : Pos->second.second;
3544  return MethList.hasMoreThanOneDecl();
3545 }
3546 
3547 ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R,
3548  bool receiverIdOrClass,
3549  bool instance) {
3550  if (ExternalSource)
3551  ReadMethodPool(Sel);
3552 
3553  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
3554  if (Pos == MethodPool.end())
3555  return nullptr;
3556 
3557  // Gather the non-hidden methods.
3558  ObjCMethodList &MethList = instance ? Pos->second.first : Pos->second.second;
3560  for (ObjCMethodList *M = &MethList; M; M = M->getNext()) {
3561  if (M->getMethod() && M->getMethod()->isUnconditionallyVisible())
3562  return M->getMethod();
3563  }
3564  return nullptr;
3565 }
3566 
3568  Selector Sel, SourceRange R,
3569  bool receiverIdOrClass) {
3570  // We found multiple methods, so we may have to complain.
3571  bool issueDiagnostic = false, issueError = false;
3572 
3573  // We support a warning which complains about *any* difference in
3574  // method signature.
3575  bool strictSelectorMatch =
3576  receiverIdOrClass &&
3577  !Diags.isIgnored(diag::warn_strict_multiple_method_decl, R.getBegin());
3578  if (strictSelectorMatch) {
3579  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3580  if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_strict)) {
3581  issueDiagnostic = true;
3582  break;
3583  }
3584  }
3585  }
3586 
3587  // If we didn't see any strict differences, we won't see any loose
3588  // differences. In ARC, however, we also need to check for loose
3589  // mismatches, because most of them are errors.
3590  if (!strictSelectorMatch ||
3591  (issueDiagnostic && getLangOpts().ObjCAutoRefCount))
3592  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3593  // This checks if the methods differ in type mismatch.
3594  if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_loose) &&
3595  !isAcceptableMethodMismatch(Methods[0], Methods[I])) {
3596  issueDiagnostic = true;
3597  if (getLangOpts().ObjCAutoRefCount)
3598  issueError = true;
3599  break;
3600  }
3601  }
3602 
3603  if (issueDiagnostic) {
3604  if (issueError)
3605  Diag(R.getBegin(), diag::err_arc_multiple_method_decl) << Sel << R;
3606  else if (strictSelectorMatch)
3607  Diag(R.getBegin(), diag::warn_strict_multiple_method_decl) << Sel << R;
3608  else
3609  Diag(R.getBegin(), diag::warn_multiple_method_decl) << Sel << R;
3610 
3611  Diag(Methods[0]->getBeginLoc(),
3612  issueError ? diag::note_possibility : diag::note_using)
3613  << Methods[0]->getSourceRange();
3614  for (unsigned I = 1, N = Methods.size(); I != N; ++I) {
3615  Diag(Methods[I]->getBeginLoc(), diag::note_also_found)
3616  << Methods[I]->getSourceRange();
3617  }
3618  }
3619 }
3620 
3622  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
3623  if (Pos == MethodPool.end())
3624  return nullptr;
3625 
3626  GlobalMethods &Methods = Pos->second;
3627  for (const ObjCMethodList *Method = &Methods.first; Method;
3628  Method = Method->getNext())
3629  if (Method->getMethod() &&
3630  (Method->getMethod()->isDefined() ||
3631  Method->getMethod()->isPropertyAccessor()))
3632  return Method->getMethod();
3633 
3634  for (const ObjCMethodList *Method = &Methods.second; Method;
3635  Method = Method->getNext())
3636  if (Method->getMethod() &&
3637  (Method->getMethod()->isDefined() ||
3638  Method->getMethod()->isPropertyAccessor()))
3639  return Method->getMethod();
3640  return nullptr;
3641 }
3642 
3643 static void
3646  StringRef Typo, const ObjCMethodDecl * Method) {
3647  const unsigned MaxEditDistance = 1;
3648  unsigned BestEditDistance = MaxEditDistance + 1;
3649  std::string MethodName = Method->getSelector().getAsString();
3650 
3651  unsigned MinPossibleEditDistance = abs((int)MethodName.size() - (int)Typo.size());
3652  if (MinPossibleEditDistance > 0 &&
3653  Typo.size() / MinPossibleEditDistance < 1)
3654  return;
3655  unsigned EditDistance = Typo.edit_distance(MethodName, true, MaxEditDistance);
3656  if (EditDistance > MaxEditDistance)
3657  return;
3658  if (EditDistance == BestEditDistance)
3659  BestMethod.push_back(Method);
3660  else if (EditDistance < BestEditDistance) {
3661  BestMethod.clear();
3662  BestMethod.push_back(Method);
3663  }
3664 }
3665 
3667  QualType ObjectType) {
3668  if (ObjectType.isNull())
3669  return true;
3670  if (S.LookupMethodInObjectType(Sel, ObjectType, true/*Instance method*/))
3671  return true;
3672  return S.LookupMethodInObjectType(Sel, ObjectType, false/*Class method*/) !=
3673  nullptr;
3674 }
3675 
3676 const ObjCMethodDecl *
3678  QualType ObjectType) {
3679  unsigned NumArgs = Sel.getNumArgs();
3681  bool ObjectIsId = true, ObjectIsClass = true;
3682  if (ObjectType.isNull())
3683  ObjectIsId = ObjectIsClass = false;
3684  else if (!ObjectType->isObjCObjectPointerType())
3685  return nullptr;
3686  else if (const ObjCObjectPointerType *ObjCPtr =
3687  ObjectType->getAsObjCInterfacePointerType()) {
3688  ObjectType = QualType(ObjCPtr->getInterfaceType(), 0);
3689  ObjectIsId = ObjectIsClass = false;
3690  }
3691  else if (ObjectType->isObjCIdType() || ObjectType->isObjCQualifiedIdType())
3692  ObjectIsClass = false;
3693  else if (ObjectType->isObjCClassType() || ObjectType->isObjCQualifiedClassType())
3694  ObjectIsId = false;
3695  else
3696  return nullptr;
3697 
3698  for (GlobalMethodPool::iterator b = MethodPool.begin(),
3699  e = MethodPool.end(); b != e; b++) {
3700  // instance methods
3701  for (ObjCMethodList *M = &b->second.first; M; M=M->getNext())
3702  if (M->getMethod() &&
3703  (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
3704  (M->getMethod()->getSelector() != Sel)) {
3705  if (ObjectIsId)
3706  Methods.push_back(M->getMethod());
3707  else if (!ObjectIsClass &&
3708  HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
3709  ObjectType))
3710  Methods.push_back(M->getMethod());
3711  }
3712  // class methods
3713  for (ObjCMethodList *M = &b->second.second; M; M=M->getNext())
3714  if (M->getMethod() &&
3715  (M->getMethod()->getSelector().getNumArgs() == NumArgs) &&
3716  (M->getMethod()->getSelector() != Sel)) {
3717  if (ObjectIsClass)
3718  Methods.push_back(M->getMethod());
3719  else if (!ObjectIsId &&
3720  HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(),
3721  ObjectType))
3722  Methods.push_back(M->getMethod());
3723  }
3724  }
3725 
3727  for (unsigned i = 0, e = Methods.size(); i < e; i++) {
3728  HelperSelectorsForTypoCorrection(SelectedMethods,
3729  Sel.getAsString(), Methods[i]);
3730  }
3731  return (SelectedMethods.size() == 1) ? SelectedMethods[0] : nullptr;
3732 }
3733 
3734 /// DiagnoseDuplicateIvars -
3735 /// Check for duplicate ivars in the entire class at the start of
3736 /// \@implementation. This becomes necesssary because class extension can
3737 /// add ivars to a class in random order which will not be known until
3738 /// class's \@implementation is seen.
3740  ObjCInterfaceDecl *SID) {
3741  for (auto *Ivar : ID->ivars()) {
3742  if (Ivar->isInvalidDecl())
3743  continue;
3744  if (IdentifierInfo *II = Ivar->getIdentifier()) {
3745  ObjCIvarDecl* prevIvar = SID->lookupInstanceVariable(II);
3746  if (prevIvar) {
3747  Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
3748  Diag(prevIvar->getLocation(), diag::note_previous_declaration);
3749  Ivar->setInvalidDecl();
3750  }
3751  }
3752  }
3753 }
3754 
3755 /// Diagnose attempts to define ARC-__weak ivars when __weak is disabled.
3757  if (S.getLangOpts().ObjCWeak) return;
3758 
3759  for (auto ivar = ID->getClassInterface()->all_declared_ivar_begin();
3760  ivar; ivar = ivar->getNextIvar()) {
3761  if (ivar->isInvalidDecl()) continue;
3762  if (ivar->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
3763  if (S.getLangOpts().ObjCWeakRuntime) {
3764  S.Diag(ivar->getLocation(), diag::err_arc_weak_disabled);
3765  } else {
3766  S.Diag(ivar->getLocation(), diag::err_arc_weak_no_runtime);
3767  }
3768  }
3769  }
3770 }
3771 
3772 /// Diagnose attempts to use flexible array member with retainable object type.
3774  ObjCInterfaceDecl *ID) {
3775  if (!S.getLangOpts().ObjCAutoRefCount)
3776  return;
3777 
3778  for (auto ivar = ID->all_declared_ivar_begin(); ivar;
3779  ivar = ivar->getNextIvar()) {
3780  if (ivar->isInvalidDecl())
3781  continue;
3782  QualType IvarTy = ivar->getType();
3783  if (IvarTy->isIncompleteArrayType() &&
3785  IvarTy->isObjCLifetimeType()) {
3786  S.Diag(ivar->getLocation(), diag::err_flexible_array_arc_retainable);
3787  ivar->setInvalidDecl();
3788  }
3789  }
3790 }
3791 
3793  switch (CurContext->getDeclKind()) {
3794  case Decl::ObjCInterface:
3795  return Sema::OCK_Interface;
3796  case Decl::ObjCProtocol:
3797  return Sema::OCK_Protocol;
3798  case Decl::ObjCCategory:
3799  if (cast<ObjCCategoryDecl>(CurContext)->IsClassExtension())
3800  return Sema::OCK_ClassExtension;
3801  return Sema::OCK_Category;
3802  case Decl::ObjCImplementation:
3803  return Sema::OCK_Implementation;
3804  case Decl::ObjCCategoryImpl:
3806 
3807  default:
3808  return Sema::OCK_None;
3809  }
3810 }
3811 
3813  if (T->isIncompleteArrayType())
3814  return true;
3815  const auto *RecordTy = T->getAs<RecordType>();
3816  return (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember());
3817 }
3818 
3820  ObjCInterfaceDecl *IntfDecl = nullptr;
3821  ObjCInterfaceDecl::ivar_range Ivars = llvm::make_range(
3823  if ((IntfDecl = dyn_cast<ObjCInterfaceDecl>(OCD))) {
3824  Ivars = IntfDecl->ivars();
3825  } else if (auto *ImplDecl = dyn_cast<ObjCImplementationDecl>(OCD)) {
3826  IntfDecl = ImplDecl->getClassInterface();
3827  Ivars = ImplDecl->ivars();
3828  } else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(OCD)) {
3829  if (CategoryDecl->IsClassExtension()) {
3830  IntfDecl = CategoryDecl->getClassInterface();
3831  Ivars = CategoryDecl->ivars();
3832  }
3833  }
3834 
3835  // Check if variable sized ivar is in interface and visible to subclasses.
3836  if (!isa<ObjCInterfaceDecl>(OCD)) {
3837  for (auto ivar : Ivars) {
3838  if (!ivar->isInvalidDecl() && IsVariableSizedType(ivar->getType())) {
3839  S.Diag(ivar->getLocation(), diag::warn_variable_sized_ivar_visibility)
3840  << ivar->getDeclName() << ivar->getType();
3841  }
3842  }
3843  }
3844 
3845  // Subsequent checks require interface decl.
3846  if (!IntfDecl)
3847  return;
3848 
3849  // Check if variable sized ivar is followed by another ivar.
3850  for (ObjCIvarDecl *ivar = IntfDecl->all_declared_ivar_begin(); ivar;
3851  ivar = ivar->getNextIvar()) {
3852  if (ivar->isInvalidDecl() || !ivar->getNextIvar())
3853  continue;
3854  QualType IvarTy = ivar->getType();
3855  bool IsInvalidIvar = false;
3856  if (IvarTy->isIncompleteArrayType()) {
3857  S.Diag(ivar->getLocation(), diag::err_flexible_array_not_at_end)
3858  << ivar->getDeclName() << IvarTy
3859  << TTK_Class; // Use "class" for Obj-C.
3860  IsInvalidIvar = true;
3861  } else if (const RecordType *RecordTy = IvarTy->getAs<RecordType>()) {
3862  if (RecordTy->getDecl()->hasFlexibleArrayMember()) {
3863  S.Diag(ivar->getLocation(),
3864  diag::err_objc_variable_sized_type_not_at_end)
3865  << ivar->getDeclName() << IvarTy;
3866  IsInvalidIvar = true;
3867  }
3868  }
3869  if (IsInvalidIvar) {
3870  S.Diag(ivar->getNextIvar()->getLocation(),
3871  diag::note_next_ivar_declaration)
3872  << ivar->getNextIvar()->getSynthesize();
3873  ivar->setInvalidDecl();
3874  }
3875  }
3876 
3877  // Check if ObjC container adds ivars after variable sized ivar in superclass.
3878  // Perform the check only if OCD is the first container to declare ivars to
3879  // avoid multiple warnings for the same ivar.
3880  ObjCIvarDecl *FirstIvar =
3881  (Ivars.begin() == Ivars.end()) ? nullptr : *Ivars.begin();
3882  if (FirstIvar && (FirstIvar == IntfDecl->all_declared_ivar_begin())) {
3883  const ObjCInterfaceDecl *SuperClass = IntfDecl->getSuperClass();
3884  while (SuperClass && SuperClass->ivar_empty())
3885  SuperClass = SuperClass->getSuperClass();
3886  if (SuperClass) {
3887  auto IvarIter = SuperClass->ivar_begin();
3888  std::advance(IvarIter, SuperClass->ivar_size() - 1);
3889  const ObjCIvarDecl *LastIvar = *IvarIter;
3890  if (IsVariableSizedType(LastIvar->getType())) {
3891  S.Diag(FirstIvar->getLocation(),
3892  diag::warn_superclass_variable_sized_type_not_at_end)
3893  << FirstIvar->getDeclName() << LastIvar->getDeclName()
3894  << LastIvar->getType() << SuperClass->getDeclName();
3895  S.Diag(LastIvar->getLocation(), diag::note_entity_declared_at)
3896  << LastIvar->getDeclName();
3897  }
3898  }
3899  }
3900 }
3901 
3902 // Note: For class/category implementations, allMethods is always null.
3904  ArrayRef<DeclGroupPtrTy> allTUVars) {
3906  return nullptr;
3907 
3908  assert(AtEnd.isValid() && "Invalid location for '@end'");
3909 
3910  auto *OCD = cast<ObjCContainerDecl>(CurContext);
3911  Decl *ClassDecl = OCD;
3912 
3913  bool isInterfaceDeclKind =
3914  isa<ObjCInterfaceDecl>(ClassDecl) || isa<ObjCCategoryDecl>(ClassDecl)
3915  || isa<ObjCProtocolDecl>(ClassDecl);
3916  bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl);
3917 
3918  // Make synthesized accessor stub functions visible.
3919  // ActOnPropertyImplDecl() creates them as not visible in case
3920  // they are overridden by an explicit method that is encountered
3921  // later.
3922  if (auto *OID = dyn_cast<ObjCImplementationDecl>(CurContext)) {
3923  for (auto PropImpl : OID->property_impls()) {
3924  if (auto *Getter = PropImpl->getGetterMethodDecl())
3925  if (Getter->isSynthesizedAccessorStub()) {
3926  OID->makeDeclVisibleInContext(Getter);
3927  OID->addDecl(Getter);
3928  }
3929  if (auto *Setter = PropImpl->getSetterMethodDecl())
3930  if (Setter->isSynthesizedAccessorStub()) {
3931  OID->makeDeclVisibleInContext(Setter);
3932  OID->addDecl(Setter);
3933  }
3934  }
3935  }
3936 
3937  // FIXME: Remove these and use the ObjCContainerDecl/DeclContext.
3938  llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap;
3939  llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap;
3940 
3941  for (unsigned i = 0, e = allMethods.size(); i != e; i++ ) {
3942  ObjCMethodDecl *Method =
3943  cast_or_null<ObjCMethodDecl>(allMethods[i]);
3944 
3945  if (!Method) continue; // Already issued a diagnostic.
3946  if (Method->isInstanceMethod()) {
3947  /// Check for instance method of the same name with incompatible types
3948  const ObjCMethodDecl *&PrevMethod = InsMap[Method->getSelector()];
3949  bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
3950  : false;
3951  if ((isInterfaceDeclKind && PrevMethod && !match)
3952  || (checkIdenticalMethods && match)) {
3953  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
3954  << Method->getDeclName();
3955  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
3956  Method->setInvalidDecl();
3957  } else {
3958  if (PrevMethod) {
3959  Method->setAsRedeclaration(PrevMethod);
3960  if (!Context.getSourceManager().isInSystemHeader(
3961  Method->getLocation()))
3962  Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
3963  << Method->getDeclName();
3964  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
3965  }
3966  InsMap[Method->getSelector()] = Method;
3967  /// The following allows us to typecheck messages to "id".
3969  }
3970  } else {
3971  /// Check for class method of the same name with incompatible types
3972  const ObjCMethodDecl *&PrevMethod = ClsMap[Method->getSelector()];
3973  bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
3974  : false;
3975  if ((isInterfaceDeclKind && PrevMethod && !match)
3976  || (checkIdenticalMethods && match)) {
3977  Diag(Method->getLocation(), diag::err_duplicate_method_decl)
3978  << Method->getDeclName();
3979  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
3980  Method->setInvalidDecl();
3981  } else {
3982  if (PrevMethod) {
3983  Method->setAsRedeclaration(PrevMethod);
3984  if (!Context.getSourceManager().isInSystemHeader(
3985  Method->getLocation()))
3986  Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
3987  << Method->getDeclName();
3988  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
3989  }
3990  ClsMap[Method->getSelector()] = Method;
3992  }
3993  }
3994  }
3995  if (isa<ObjCInterfaceDecl>(ClassDecl)) {
3996  // Nothing to do here.
3997  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
3998  // Categories are used to extend the class by declaring new methods.
3999  // By the same token, they are also used to add new properties. No
4000  // need to compare the added property to those in the class.
4001 
4002  if (C->IsClassExtension()) {
4003  ObjCInterfaceDecl *CCPrimary = C->getClassInterface();
4004  DiagnoseClassExtensionDupMethods(C, CCPrimary);
4005  }
4006  }
4007  if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) {
4008  if (CDecl->getIdentifier())
4009  // ProcessPropertyDecl is responsible for diagnosing conflicts with any
4010  // user-defined setter/getter. It also synthesizes setter/getter methods
4011  // and adds them to the DeclContext and global method pools.
4012  for (auto *I : CDecl->properties())
4014  CDecl->setAtEndRange(AtEnd);
4015  }
4016  if (ObjCImplementationDecl *IC=dyn_cast<ObjCImplementationDecl>(ClassDecl)) {
4017  IC->setAtEndRange(AtEnd);
4018  if (ObjCInterfaceDecl* IDecl = IC->getClassInterface()) {
4019  // Any property declared in a class extension might have user
4020  // declared setter or getter in current class extension or one
4021  // of the other class extensions. Mark them as synthesized as
4022  // property will be synthesized when property with same name is
4023  // seen in the @implementation.
4024  for (const auto *Ext : IDecl->visible_extensions()) {
4025  for (const auto *Property : Ext->instance_properties()) {
4026  // Skip over properties declared @dynamic
4027  if (const ObjCPropertyImplDecl *PIDecl
4028  = IC->FindPropertyImplDecl(Property->getIdentifier(),
4029  Property->getQueryKind()))
4030  if (PIDecl->getPropertyImplementation()
4032  continue;
4033 
4034  for (const auto *Ext : IDecl->visible_extensions()) {
4035  if (ObjCMethodDecl *GetterMethod =
4036  Ext->getInstanceMethod(Property->getGetterName()))
4037  GetterMethod->setPropertyAccessor(true);
4038  if (!Property->isReadOnly())
4039  if (ObjCMethodDecl *SetterMethod
4040  = Ext->getInstanceMethod(Property->getSetterName()))
4041  SetterMethod->setPropertyAccessor(true);
4042  }
4043  }
4044  }
4045  ImplMethodsVsClassMethods(S, IC, IDecl);
4049  if (IDecl->hasDesignatedInitializers())
4051  DiagnoseWeakIvars(*this, IC);
4053 
4054  bool HasRootClassAttr = IDecl->hasAttr<ObjCRootClassAttr>();
4055  if (IDecl->getSuperClass() == nullptr) {
4056  // This class has no superclass, so check that it has been marked with
4057  // __attribute((objc_root_class)).
4058  if (!HasRootClassAttr) {
4059  SourceLocation DeclLoc(IDecl->getLocation());
4060  SourceLocation SuperClassLoc(getLocForEndOfToken(DeclLoc));
4061  Diag(DeclLoc, diag::warn_objc_root_class_missing)
4062  << IDecl->getIdentifier();
4063  // See if NSObject is in the current scope, and if it is, suggest
4064  // adding " : NSObject " to the class declaration.
4066  NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject),
4067  DeclLoc, LookupOrdinaryName);
4068  ObjCInterfaceDecl *NSObjectDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
4069  if (NSObjectDecl && NSObjectDecl->getDefinition()) {
4070  Diag(SuperClassLoc, diag::note_objc_needs_superclass)
4071  << FixItHint::CreateInsertion(SuperClassLoc, " : NSObject ");
4072  } else {
4073  Diag(SuperClassLoc, diag::note_objc_needs_superclass);
4074  }
4075  }
4076  } else if (HasRootClassAttr) {
4077  // Complain that only root classes may have this attribute.
4078  Diag(IDecl->getLocation(), diag::err_objc_root_class_subclass);
4079  }
4080 
4081  if (const ObjCInterfaceDecl *Super = IDecl->getSuperClass()) {
4082  // An interface can subclass another interface with a
4083  // objc_subclassing_restricted attribute when it has that attribute as
4084  // well (because of interfaces imported from Swift). Therefore we have
4085  // to check if we can subclass in the implementation as well.
4086  if (IDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
4087  Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
4088  Diag(IC->getLocation(), diag::err_restricted_superclass_mismatch);
4089  Diag(Super->getLocation(), diag::note_class_declared);
4090  }
4091  }
4092 
4093  if (IDecl->hasAttr<ObjCClassStubAttr>())
4094  Diag(IC->getLocation(), diag::err_implementation_of_class_stub);
4095 
4097  while (IDecl->getSuperClass()) {
4098  DiagnoseDuplicateIvars(IDecl, IDecl->getSuperClass());
4099  IDecl = IDecl->getSuperClass();
4100  }
4101  }
4102  }
4103  SetIvarInitializers(IC);
4104  } else if (ObjCCategoryImplDecl* CatImplClass =
4105  dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) {
4106  CatImplClass->setAtEndRange(AtEnd);
4107 
4108  // Find category interface decl and then check that all methods declared
4109  // in this interface are implemented in the category @implementation.
4110  if (ObjCInterfaceDecl* IDecl = CatImplClass->getClassInterface()) {
4111  if (ObjCCategoryDecl *Cat
4112  = IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier())) {
4113  ImplMethodsVsClassMethods(S, CatImplClass, Cat);
4114  }
4115  }
4116  } else if (const auto *IntfDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
4117  if (const ObjCInterfaceDecl *Super = IntfDecl->getSuperClass()) {
4118  if (!IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>() &&
4119  Super->hasAttr<ObjCSubclassingRestrictedAttr>()) {
4120  Diag(IntfDecl->getLocation(), diag::err_restricted_superclass_mismatch);
4121  Diag(Super->getLocation(), diag::note_class_declared);
4122  }
4123  }
4124 
4125  if (IntfDecl->hasAttr<ObjCClassStubAttr>() &&
4126  !IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>())
4127  Diag(IntfDecl->getLocation(), diag::err_class_stub_subclassing_mismatch);
4128  }
4129  DiagnoseVariableSizedIvars(*this, OCD);
4130  if (isInterfaceDeclKind) {
4131  // Reject invalid vardecls.
4132  for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
4133  DeclGroupRef DG = allTUVars[i].get();
4134  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
4135  if (VarDecl *VDecl = dyn_cast<VarDecl>(*I)) {
4136  if (!VDecl->hasExternalStorage())
4137  Diag(VDecl->getLocation(), diag::err_objc_var_decl_inclass);
4138  }
4139  }
4140  }
4142 
4143  for (unsigned i = 0, e = allTUVars.size(); i != e; i++) {
4144  DeclGroupRef DG = allTUVars[i].get();
4145  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
4146  (*I)->setTopLevelDeclInObjCContainer();
4148  }
4149 
4150  ActOnDocumentableDecl(ClassDecl);
4151  return ClassDecl;
4152 }
4153 
4154 /// CvtQTToAstBitMask - utility routine to produce an AST bitmask for
4155 /// objective-c's type qualifier from the parser version of the same info.
4158  return (Decl::ObjCDeclQualifier) (unsigned) PQTVal;
4159 }
4160 
4161 /// Check whether the declared result type of the given Objective-C
4162 /// method declaration is compatible with the method's class.
4163 ///
4166  ObjCInterfaceDecl *CurrentClass) {
4167  QualType ResultType = Method->getReturnType();
4168 
4169  // If an Objective-C method inherits its related result type, then its
4170  // declared result type must be compatible with its own class type. The
4171  // declared result type is compatible if:
4172  if (const ObjCObjectPointerType *ResultObjectType
4173  = ResultType->getAs<ObjCObjectPointerType>()) {
4174  // - it is id or qualified id, or
4175  if (ResultObjectType->isObjCIdType() ||
4176  ResultObjectType->isObjCQualifiedIdType())
4177  return Sema::RTC_Compatible;
4178 
4179  if (CurrentClass) {
4180  if (ObjCInterfaceDecl *ResultClass
4181  = ResultObjectType->getInterfaceDecl()) {
4182  // - it is the same as the method's class type, or
4183  if (declaresSameEntity(CurrentClass, ResultClass))
4184  return Sema::RTC_Compatible;
4185 
4186  // - it is a superclass of the method's class type
4187  if (ResultClass->isSuperClassOf(CurrentClass))
4188  return Sema::RTC_Compatible;
4189  }
4190  } else {
4191  // Any Objective-C pointer type might be acceptable for a protocol
4192  // method; we just don't know.
4193  return Sema::RTC_Unknown;
4194  }
4195  }
4196 
4197  return Sema::RTC_Incompatible;
4198 }
4199 
4200 namespace {
4201 /// A helper class for searching for methods which a particular method
4202 /// overrides.
4203 class OverrideSearch {
4204 public:
4205  const ObjCMethodDecl *Method;
4207  bool Recursive;
4208 
4209 public:
4210  OverrideSearch(Sema &S, const ObjCMethodDecl *method) : Method(method) {
4211  Selector selector = method->getSelector();
4212 
4213  // Bypass this search if we've never seen an instance/class method
4214  // with this selector before.
4215  Sema::GlobalMethodPool::iterator it = S.MethodPool.find(selector);
4216  if (it == S.MethodPool.end()) {
4217  if (!S.getExternalSource()) return;
4218  S.ReadMethodPool(selector);
4219 
4220  it = S.MethodPool.find(selector);
4221  if (it == S.MethodPool.end())
4222  return;
4223  }
4224  const ObjCMethodList &list =
4225  method->isInstanceMethod() ? it->second.first : it->second.second;
4226  if (!list.getMethod()) return;
4227 
4228  const ObjCContainerDecl *container
4229  = cast<ObjCContainerDecl>(method->getDeclContext());
4230 
4231  // Prevent the search from reaching this container again. This is
4232  // important with categories, which override methods from the
4233  // interface and each other.
4234  if (const ObjCCategoryDecl *Category =
4235  dyn_cast<ObjCCategoryDecl>(container)) {
4236  searchFromContainer(container);
4237  if (const ObjCInterfaceDecl *Interface = Category->getClassInterface())
4238  searchFromContainer(Interface);
4239  } else {
4240  searchFromContainer(container);
4241  }
4242  }
4243 
4244  typedef decltype(Overridden)::iterator iterator;
4245  iterator begin() const { return Overridden.begin(); }
4246  iterator end() const { return Overridden.end(); }
4247 
4248 private:
4249  void searchFromContainer(const ObjCContainerDecl *container) {
4250  if (container->isInvalidDecl()) return;
4251 
4252  switch (container->getDeclKind()) {
4253 #define OBJCCONTAINER(type, base) \
4254  case Decl::type: \
4255  searchFrom(cast<type##Decl>(container)); \
4256  break;
4257 #define ABSTRACT_DECL(expansion)
4258 #define DECL(type, base) \
4259  case Decl::type:
4260 #include "clang/AST/DeclNodes.inc"
4261  llvm_unreachable("not an ObjC container!");
4262  }
4263  }
4264 
4265  void searchFrom(const ObjCProtocolDecl *protocol) {
4266  if (!protocol->hasDefinition())
4267  return;
4268 
4269  // A method in a protocol declaration overrides declarations from
4270  // referenced ("parent") protocols.
4271  search(protocol->getReferencedProtocols());
4272  }
4273 
4274  void searchFrom(const ObjCCategoryDecl *category) {
4275  // A method in a category declaration overrides declarations from
4276  // the main class and from protocols the category references.
4277  // The main class is handled in the constructor.
4278  search(category->getReferencedProtocols());
4279  }
4280 
4281  void searchFrom(const ObjCCategoryImplDecl *impl) {
4282  // A method in a category definition that has a category
4283  // declaration overrides declarations from the category
4284  // declaration.
4285  if (ObjCCategoryDecl *category = impl->getCategoryDecl()) {
4286  search(category);
4287  if (ObjCInterfaceDecl *Interface = category->getClassInterface())
4288  search(Interface);
4289 
4290  // Otherwise it overrides declarations from the class.
4291  } else if (const auto *Interface = impl->getClassInterface()) {
4292  search(Interface);
4293  }
4294  }
4295 
4296  void searchFrom(const ObjCInterfaceDecl *iface) {
4297  // A method in a class declaration overrides declarations from
4298  if (!iface->hasDefinition())
4299  return;
4300 
4301  // - categories,
4302  for (auto *Cat : iface->known_categories())
4303  search(Cat);
4304 
4305  // - the super class, and
4306  if (ObjCInterfaceDecl *super = iface->getSuperClass())
4307  search(super);
4308 
4309  // - any referenced protocols.
4310  search(iface->getReferencedProtocols());
4311  }
4312 
4313  void searchFrom(const ObjCImplementationDecl *impl) {
4314  // A method in a class implementation overrides declarations from
4315  // the class interface.
4316  if (const auto *Interface = impl->getClassInterface())
4317  search(Interface);
4318  }
4319 
4320  void search(const ObjCProtocolList &protocols) {
4321  for (const auto *Proto : protocols)
4322  search(Proto);
4323  }
4324 
4325  void search(const ObjCContainerDecl *container) {
4326  // Check for a method in this container which matches this selector.
4327  ObjCMethodDecl *meth = container->getMethod(Method->getSelector(),
4328  Method->isInstanceMethod(),
4329  /*AllowHidden=*/true);
4330 
4331  // If we find one, record it and bail out.
4332  if (meth) {
4333  Overridden.insert(meth);
4334  return;
4335  }
4336 
4337  // Otherwise, search for methods that a hypothetical method here
4338  // would have overridden.
4339 
4340  // Note that we're now in a recursive case.
4341  Recursive = true;
4342 
4343  searchFromContainer(container);
4344  }
4345 };
4346 } // end anonymous namespace
4347 
4349  ObjCMethodDecl *overridden) {
4350  if (const auto *attr = overridden->getAttr<ObjCDirectAttr>()) {
4351  Diag(method->getLocation(), diag::err_objc_override_direct_method);
4352  Diag(attr->getLocation(), diag::note_previous_declaration);
4353  } else if (const auto *attr = method->getAttr<ObjCDirectAttr>()) {
4354  Diag(attr->getLocation(), diag::err_objc_direct_on_override)
4355  << isa<ObjCProtocolDecl>(overridden->getDeclContext());
4356  Diag(overridden->getLocation(), diag::note_previous_declaration);
4357  }
4358 }
4359 
4361  ObjCInterfaceDecl *CurrentClass,
4363  if (!ObjCMethod)
4364  return;
4365  // Search for overridden methods and merge information down from them.
4366  OverrideSearch overrides(*this, ObjCMethod);
4367  // Keep track if the method overrides any method in the class's base classes,
4368  // its protocols, or its categories' protocols; we will keep that info
4369  // in the ObjCMethodDecl.
4370  // For this info, a method in an implementation is not considered as
4371  // overriding the same method in the interface or its categories.
4372  bool hasOverriddenMethodsInBaseOrProtocol = false;
4373  for (ObjCMethodDecl *overridden : overrides) {
4374  if (!hasOverriddenMethodsInBaseOrProtocol) {
4375  if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
4376  CurrentClass != overridden->getClassInterface() ||
4377  overridden->isOverriding()) {
4378  CheckObjCMethodDirectOverrides(ObjCMethod, overridden);
4379  hasOverriddenMethodsInBaseOrProtocol = true;
4380  } else if (isa<ObjCImplDecl>(ObjCMethod->getDeclContext())) {
4381  // OverrideSearch will return as "overridden" the same method in the
4382  // interface. For hasOverriddenMethodsInBaseOrProtocol, we need to
4383  // check whether a category of a base class introduced a method with the
4384  // same selector, after the interface method declaration.
4385  // To avoid unnecessary lookups in the majority of cases, we use the
4386  // extra info bits in GlobalMethodPool to check whether there were any
4387  // category methods with this selector.
4388  GlobalMethodPool::iterator It =
4389  MethodPool.find(ObjCMethod->getSelector());
4390  if (It != MethodPool.end()) {
4391  ObjCMethodList &List =
4392  ObjCMethod->isInstanceMethod()? It->second.first: It->second.second;
4393  unsigned CategCount = List.getBits();
4394  if (CategCount > 0) {
4395  // If the method is in a category we'll do lookup if there were at
4396  // least 2 category methods recorded, otherwise only one will do.
4397  if (CategCount > 1 ||
4398  !isa<ObjCCategoryImplDecl>(overridden->getDeclContext())) {
4399  OverrideSearch overrides(*this, overridden);
4400  for (ObjCMethodDecl *SuperOverridden : overrides) {
4401  if (isa<ObjCProtocolDecl>(SuperOverridden->getDeclContext()) ||
4402  CurrentClass != SuperOverridden->getClassInterface()) {
4403  CheckObjCMethodDirectOverrides(ObjCMethod, SuperOverridden);
4404  hasOverriddenMethodsInBaseOrProtocol = true;
4405  overridden->setOverriding(true);
4406  break;
4407  }
4408  }
4409  }
4410  }
4411  }
4412  }
4413  }
4414 
4415  // Propagate down the 'related result type' bit from overridden methods.
4416  if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType())
4417  ObjCMethod->setRelatedResultType();
4418 
4419  // Then merge the declarations.
4420  mergeObjCMethodDecls(ObjCMethod, overridden);
4421 
4422  if (ObjCMethod->isImplicit() && overridden->isImplicit())
4423  continue; // Conflicting properties are detected elsewhere.
4424 
4425  // Check for overriding methods
4426  if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) ||
4427  isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
4428  CheckConflictingOverridingMethod(ObjCMethod, overridden,
4429  isa<ObjCProtocolDecl>(overridden->getDeclContext()));
4430 
4431  if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
4432  isa<ObjCInterfaceDecl>(overridden->getDeclContext()) &&
4433  !overridden->isImplicit() /* not meant for properties */) {
4434  ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
4435  E = ObjCMethod->param_end();
4436  ObjCMethodDecl::param_iterator PrevI = overridden->param_begin(),
4437  PrevE = overridden->param_end();
4438  for (; ParamI != E && PrevI != PrevE; ++ParamI, ++PrevI) {
4439  assert(PrevI != overridden->param_end() && "Param mismatch");
4440  QualType T1 = Context.getCanonicalType((*ParamI)->getType());
4441  QualType T2 = Context.getCanonicalType((*PrevI)->getType());
4442  // If type of argument of method in this class does not match its
4443  // respective argument type in the super class method, issue warning;
4444  if (!Context.typesAreCompatible(T1, T2)) {
4445  Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
4446  << T1 << T2;
4447  Diag(overridden->getLocation(), diag::note_previous_declaration);
4448  break;
4449  }
4450  }
4451  }
4452  }
4453 
4454  ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol);
4455 }
4456 
4457 /// Merge type nullability from for a redeclaration of the same entity,
4458 /// producing the updated type of the redeclared entity.
4460  QualType type,
4461  bool usesCSKeyword,
4462  SourceLocation prevLoc,
4463  QualType prevType,
4464  bool prevUsesCSKeyword) {
4465  // Determine the nullability of both types.
4466  auto nullability = type->getNullability(S.Context);
4467  auto prevNullability = prevType->getNullability(S.Context);
4468 
4469  // Easy case: both have nullability.
4470  if (nullability.hasValue() == prevNullability.hasValue()) {
4471  // Neither has nullability; continue.
4472  if (!nullability)
4473  return type;
4474 
4475  // The nullabilities are equivalent; do nothing.
4476  if (*nullability == *prevNullability)
4477  return type;
4478 
4479  // Complain about mismatched nullability.
4480  S.Diag(loc, diag::err_nullability_conflicting)
4481  << DiagNullabilityKind(*nullability, usesCSKeyword)
4482  << DiagNullabilityKind(*prevNullability, prevUsesCSKeyword);
4483  return type;
4484  }
4485 
4486  // If it's the redeclaration that has nullability, don't change anything.
4487  if (nullability)
4488  return type;
4489 
4490  // Otherwise, provide the result with the same nullability.
4491  return S.Context.getAttributedType(
4492  AttributedType::getNullabilityAttrKind(*prevNullability),
4493  type, type);
4494 }
4495 
4496 /// Merge information from the declaration of a method in the \@interface
4497 /// (or a category/extension) into the corresponding method in the
4498 /// @implementation (for a class or category).
4500  ObjCMethodDecl *method,
4501  ObjCMethodDecl *prevMethod) {
4502  // Merge the objc_requires_super attribute.
4503  if (prevMethod->hasAttr<ObjCRequiresSuperAttr>() &&
4504  !method->hasAttr<ObjCRequiresSuperAttr>()) {
4505  // merge the attribute into implementation.
4506  method->addAttr(
4507  ObjCRequiresSuperAttr::CreateImplicit(S.Context,
4508  method->getLocation()));
4509  }
4510 
4511  // Merge nullability of the result type.
4512  QualType newReturnType
4514  S, method->getReturnTypeSourceRange().getBegin(),
4515  method->getReturnType(),
4517  prevMethod->getReturnTypeSourceRange().getBegin(),
4518  prevMethod->getReturnType(),
4520  method->setReturnType(newReturnType);
4521 
4522  // Handle each of the parameters.
4523  unsigned numParams = method->param_size();
4524  unsigned numPrevParams = prevMethod->param_size();
4525  for (unsigned i = 0, n = std::min(numParams, numPrevParams); i != n; ++i) {
4526  ParmVarDecl *param = method->param_begin()[i];
4527  ParmVarDecl *prevParam = prevMethod->param_begin()[i];
4528 
4529  // Merge nullability.
4530  QualType newParamType
4532  S, param->getLocation(), param->getType(),
4534  prevParam->getLocation(), prevParam->getType(),
4536  param->setType(newParamType);
4537  }
4538 }
4539 
4540 /// Verify that the method parameters/return value have types that are supported
4541 /// by the x86 target.
4543  const ObjCMethodDecl *Method) {
4544  assert(SemaRef.getASTContext().getTargetInfo().getTriple().getArch() ==
4545  llvm::Triple::x86 &&
4546  "x86-specific check invoked for a different target");
4547  SourceLocation Loc;
4548  QualType T;
4549  for (const ParmVarDecl *P : Method->parameters()) {
4550  if (P->getType()->isVectorType()) {
4551  Loc = P->getBeginLoc();
4552  T = P->getType();
4553  break;
4554  }
4555  }
4556  if (Loc.isInvalid()) {
4557  if (Method->getReturnType()->isVectorType()) {
4558  Loc = Method->getReturnTypeSourceRange().getBegin();
4559  T = Method->getReturnType();
4560  } else
4561  return;
4562  }
4563 
4564  // Vector parameters/return values are not supported by objc_msgSend on x86 in
4565  // iOS < 9 and macOS < 10.11.
4566  const auto &Triple = SemaRef.getASTContext().getTargetInfo().getTriple();
4567  VersionTuple AcceptedInVersion;
4568  if (Triple.getOS() == llvm::Triple::IOS)
4569  AcceptedInVersion = VersionTuple(/*Major=*/9);
4570  else if (Triple.isMacOSX())
4571  AcceptedInVersion = VersionTuple(/*Major=*/10, /*Minor=*/11);
4572  else
4573  return;
4575  AcceptedInVersion)
4576  return;
4577  SemaRef.Diag(Loc, diag::err_objc_method_unsupported_param_ret_type)
4578  << T << (Method->getReturnType()->isVectorType() ? /*return value*/ 1
4579  : /*parameter*/ 0)
4580  << (Triple.isMacOSX() ? "macOS 10.11" : "iOS 9");
4581 }
4582 
4583 static void mergeObjCDirectMembers(Sema &S, Decl *CD, ObjCMethodDecl *Method) {
4584  if (!Method->isDirectMethod() && !Method->hasAttr<UnavailableAttr>() &&
4585  CD->hasAttr<ObjCDirectMembersAttr>()) {
4586  Method->addAttr(
4587  ObjCDirectAttr::CreateImplicit(S.Context, Method->getLocation()));
4588  }
4589 }
4590 
4592  ObjCMethodDecl *Method,
4593  ObjCImplDecl *ImpDecl = nullptr) {
4594  auto Sel = Method->getSelector();
4595  bool isInstance = Method->isInstanceMethod();
4596  bool diagnosed = false;
4597 
4598  auto diagClash = [&](const ObjCMethodDecl *IMD) {
4599  if (diagnosed || IMD->isImplicit())
4600  return;
4601  if (Method->isDirectMethod() || IMD->isDirectMethod()) {
4602  S.Diag(Method->getLocation(), diag::err_objc_direct_duplicate_decl)
4603  << Method->isDirectMethod() << /* method */ 0 << IMD->isDirectMethod()
4604  << Method->getDeclName();
4605  S.Diag(IMD->getLocation(), diag::note_previous_declaration);
4606  diagnosed = true;
4607  }
4608  };
4609 
4610  // Look for any other declaration of this method anywhere we can see in this
4611  // compilation unit.
4612  //
4613  // We do not use IDecl->lookupMethod() because we have specific needs:
4614  //
4615  // - we absolutely do not need to walk protocols, because
4616  // diag::err_objc_direct_on_protocol has already been emitted
4617  // during parsing if there's a conflict,
4618  //
4619  // - when we do not find a match in a given @interface container,
4620  // we need to attempt looking it up in the @implementation block if the
4621  // translation unit sees it to find more clashes.
4622 
4623  if (auto *IMD = IDecl->getMethod(Sel, isInstance))
4624  diagClash(IMD);
4625  else if (auto *Impl = IDecl->getImplementation())
4626  if (Impl != ImpDecl)
4627  if (auto *IMD = IDecl->getImplementation()->getMethod(Sel, isInstance))
4628  diagClash(IMD);
4629 
4630  for (const auto *Cat : IDecl->visible_categories())
4631  if (auto *IMD = Cat->getMethod(Sel, isInstance))
4632  diagClash(IMD);
4633  else if (auto CatImpl = Cat->getImplementation())
4634  if (CatImpl != ImpDecl)
4635  if (auto *IMD = Cat->getMethod(Sel, isInstance))
4636  diagClash(IMD);
4637 }
4638 
4640  Scope *S, SourceLocation MethodLoc, SourceLocation EndLoc,
4641  tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
4642  ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
4643  // optional arguments. The number of types/arguments is obtained
4644  // from the Sel.getNumArgs().
4645  ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo,
4646  unsigned CNumArgs, // c-style args
4647  const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodDeclKind,
4648  bool isVariadic, bool MethodDefinition) {
4649  // Make sure we can establish a context for the method.
4650  if (!CurContext->isObjCContainer()) {
4651  Diag(MethodLoc, diag::err_missing_method_context);
4652  return nullptr;
4653  }
4654 
4655  Decl *ClassDecl = cast<ObjCContainerDecl>(CurContext);
4656  QualType resultDeclType;
4657 
4658  bool HasRelatedResultType = false;
4659  TypeSourceInfo *ReturnTInfo = nullptr;
4660  if (ReturnType) {
4661  resultDeclType = GetTypeFromParser(ReturnType, &ReturnTInfo);
4662 
4663  if (CheckFunctionReturnType(resultDeclType, MethodLoc))
4664  return nullptr;
4665 
4666  QualType bareResultType = resultDeclType;
4667  (void)AttributedType::stripOuterNullability(bareResultType);
4668  HasRelatedResultType = (bareResultType == Context.getObjCInstanceType());
4669  } else { // get the type for "id".
4670  resultDeclType = Context.getObjCIdType();
4671  Diag(MethodLoc, diag::warn_missing_method_return_type)
4672  << FixItHint::CreateInsertion(SelectorLocs.front(), "(id)");
4673  }
4674 
4675  ObjCMethodDecl *ObjCMethod = ObjCMethodDecl::Create(
4676  Context, MethodLoc, EndLoc, Sel, resultDeclType, ReturnTInfo, CurContext,
4677  MethodType == tok::minus, isVariadic,
4678  /*isPropertyAccessor=*/false, /*isSynthesizedAccessorStub=*/false,
4679  /*isImplicitlyDeclared=*/false, /*isDefined=*/false,
4680  MethodDeclKind == tok::objc_optional ? ObjCMethodDecl::Optional
4682  HasRelatedResultType);
4683 
4685 
4686  for (unsigned i = 0, e = Sel.getNumArgs(); i != e; ++i) {
4687  QualType ArgType;
4688  TypeSourceInfo *DI;
4689 
4690  if (!ArgInfo[i].Type) {
4691  ArgType = Context.getObjCIdType();
4692  DI = nullptr;
4693  } else {
4694  ArgType = GetTypeFromParser(ArgInfo[i].Type, &DI);
4695  }
4696 
4697  LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc,
4699  LookupName(R, S);
4700  if (R.isSingleResult()) {
4701  NamedDecl *PrevDecl = R.getFoundDecl();
4702  if (S->isDeclScope(PrevDecl)) {
4703  Diag(ArgInfo[i].NameLoc,
4704  (MethodDefinition ? diag::warn_method_param_redefinition
4705  : diag::warn_method_param_declaration))
4706  << ArgInfo[i].Name;
4707  Diag(PrevDecl->getLocation(),
4708  diag::note_previous_declaration);
4709  }
4710  }
4711 
4712  SourceLocation StartLoc = DI
4713  ? DI->getTypeLoc().getBeginLoc()
4714  : ArgInfo[i].NameLoc;
4715 
4716  ParmVarDecl* Param = CheckParameter(ObjCMethod, StartLoc,
4717  ArgInfo[i].NameLoc, ArgInfo[i].Name,
4718  ArgType, DI, SC_None);
4719 
4720  Param->setObjCMethodScopeInfo(i);
4721 
4722  Param->setObjCDeclQualifier(
4723  CvtQTToAstBitMask(ArgInfo[i].DeclSpec.getObjCDeclQualifier()));
4724 
4725  // Apply the attributes to the parameter.
4726  ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs);
4727  AddPragmaAttributes(TUScope, Param);
4728 
4729  if (Param->hasAttr<BlocksAttr>()) {
4730  Diag(Param->getLocation(), diag::err_block_on_nonlocal);
4731  Param->setInvalidDecl();
4732  }
4733  S->AddDecl(Param);
4734  IdResolver.AddDecl(Param);
4735 
4736  Params.push_back(Param);
4737  }
4738 
4739  for (unsigned i = 0, e = CNumArgs; i != e; ++i) {
4740  ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param);
4741  QualType ArgType = Param->getType();
4742  if (ArgType.isNull())
4743  ArgType = Context.getObjCIdType();
4744  else
4745  // Perform the default array/function conversions (C99 6.7.5.3p[7,8]).
4746  ArgType = Context.getAdjustedParameterType(ArgType);
4747 
4748  Param->setDeclContext(ObjCMethod);
4749  Params.push_back(Param);
4750  }
4751 
4752  ObjCMethod->setMethodParams(Context, Params, SelectorLocs);
4753  ObjCMethod->setObjCDeclQualifier(
4755 
4756  ProcessDeclAttributeList(TUScope, ObjCMethod, AttrList);
4757  AddPragmaAttributes(TUScope, ObjCMethod);
4758 
4759  // Add the method now.
4760  const ObjCMethodDecl *PrevMethod = nullptr;
4761  if (ObjCImplDecl *ImpDecl = dyn_cast<ObjCImplDecl>(ClassDecl)) {
4762  if (MethodType == tok::minus) {
4763  PrevMethod = ImpDecl->getInstanceMethod(Sel);
4764  ImpDecl->addInstanceMethod(ObjCMethod);
4765  } else {
4766  PrevMethod = ImpDecl->getClassMethod(Sel);
4767  ImpDecl->addClassMethod(ObjCMethod);
4768  }
4769 
4770  // If this method overrides a previous @synthesize declaration,
4771  // register it with the property. Linear search through all
4772  // properties here, because the autosynthesized stub hasn't been
4773  // made visible yet, so it can be overriden by a later
4774  // user-specified implementation.
4775  for (ObjCPropertyImplDecl *PropertyImpl : ImpDecl->property_impls()) {
4776  if (auto *Setter = PropertyImpl->getSetterMethodDecl())
4777  if (Setter->getSelector() == Sel &&
4778  Setter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
4779  assert(Setter->isSynthesizedAccessorStub() && "autosynth stub expected");
4780  PropertyImpl->setSetterMethodDecl(ObjCMethod);
4781  }
4782  if (auto *Getter = PropertyImpl->getGetterMethodDecl())
4783  if (Getter->getSelector() == Sel &&
4784  Getter->isInstanceMethod() == ObjCMethod->isInstanceMethod()) {
4785  assert(Getter->isSynthesizedAccessorStub() && "autosynth stub expected");
4786  PropertyImpl->setGetterMethodDecl(ObjCMethod);
4787  break;
4788  }
4789  }
4790 
4791  // A method is either tagged direct explicitly, or inherits it from its
4792  // canonical declaration.
4793  //
4794  // We have to do the merge upfront and not in mergeInterfaceMethodToImpl()
4795  // because IDecl->lookupMethod() returns more possible matches than just
4796  // the canonical declaration.
4797  if (!ObjCMethod->isDirectMethod()) {
4798  const ObjCMethodDecl *CanonicalMD = ObjCMethod->getCanonicalDecl();
4799  if (const auto *attr = CanonicalMD->getAttr<ObjCDirectAttr>()) {
4800  ObjCMethod->addAttr(
4801  ObjCDirectAttr::CreateImplicit(Context, attr->getLocation()));
4802  }
4803  }
4804 
4805  // Merge information from the @interface declaration into the
4806  // @implementation.
4807  if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface()) {
4808  if (auto *IMD = IDecl->lookupMethod(ObjCMethod->getSelector(),
4809  ObjCMethod->isInstanceMethod())) {
4810  mergeInterfaceMethodToImpl(*this, ObjCMethod, IMD);
4811 
4812  // The Idecl->lookupMethod() above will find declarations for ObjCMethod
4813  // in one of these places:
4814  //
4815  // (1) the canonical declaration in an @interface container paired
4816  // with the ImplDecl,
4817  // (2) non canonical declarations in @interface not paired with the
4818  // ImplDecl for the same Class,
4819  // (3) any superclass container.
4820  //
4821  // Direct methods only allow for canonical declarations in the matching
4822  // container (case 1).
4823  //
4824  // Direct methods overriding a superclass declaration (case 3) is
4825  // handled during overrides checks in CheckObjCMethodOverrides().
4826  //
4827  // We deal with same-class container mismatches (Case 2) here.
4828  if (IDecl == IMD->getClassInterface()) {
4829  auto diagContainerMismatch = [&] {
4830  int decl = 0, impl = 0;
4831 
4832  if (auto *Cat = dyn_cast<ObjCCategoryDecl>(IMD->getDeclContext()))
4833  decl = Cat->IsClassExtension() ? 1 : 2;
4834 
4835  if (isa<ObjCCategoryImplDecl>(ImpDecl))
4836  impl = 1 + (decl != 0);
4837 
4838  Diag(ObjCMethod->getLocation(),
4839  diag::err_objc_direct_impl_decl_mismatch)
4840  << decl << impl;
4841  Diag(IMD->getLocation(), diag::note_previous_declaration);
4842  };
4843 
4844  if (const auto *attr = ObjCMethod->getAttr<ObjCDirectAttr>()) {
4845  if (ObjCMethod->getCanonicalDecl() != IMD) {
4846  diagContainerMismatch();
4847  } else if (!IMD->isDirectMethod()) {
4848  Diag(attr->getLocation(), diag::err_objc_direct_missing_on_decl);
4849  Diag(IMD->getLocation(), diag::note_previous_declaration);
4850  }
4851  } else if (const auto *attr = IMD->getAttr<ObjCDirectAttr>()) {
4852  if (ObjCMethod->getCanonicalDecl() != IMD) {
4853  diagContainerMismatch();
4854  } else {
4855  ObjCMethod->addAttr(
4856  ObjCDirectAttr::CreateImplicit(Context, attr->getLocation()));
4857  }
4858  }
4859  }
4860 
4861  // Warn about defining -dealloc in a category.
4862  if (isa<ObjCCategoryImplDecl>(ImpDecl) && IMD->isOverriding() &&
4863  ObjCMethod->getSelector().getMethodFamily() == OMF_dealloc) {
4864  Diag(ObjCMethod->getLocation(), diag::warn_dealloc_in_category)
4865  << ObjCMethod->getDeclName();
4866  }
4867  } else {
4868  mergeObjCDirectMembers(*this, ClassDecl, ObjCMethod);
4869  checkObjCDirectMethodClashes(*this, IDecl, ObjCMethod, ImpDecl);
4870  }
4871 
4872  // Warn if a method declared in a protocol to which a category or
4873  // extension conforms is non-escaping and the implementation's method is
4874  // escaping.
4875  for (auto *C : IDecl->visible_categories())
4876  for (auto &P : C->protocols())
4877  if (auto *IMD = P->lookupMethod(ObjCMethod->getSelector(),
4878  ObjCMethod->isInstanceMethod())) {
4879  assert(ObjCMethod->parameters().size() ==
4880  IMD->parameters().size() &&
4881  "Methods have different number of parameters");
4882  auto OI = IMD->param_begin(), OE = IMD->param_end();
4883  auto NI = ObjCMethod->param_begin();
4884  for (; OI != OE; ++OI, ++NI)
4885  diagnoseNoescape(*NI, *OI, C, P, *this);
4886  }
4887  }
4888  } else {
4889  if (!isa<ObjCProtocolDecl>(ClassDecl)) {
4890  mergeObjCDirectMembers(*this, ClassDecl, ObjCMethod);
4891 
4892  ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
4893  if (!IDecl)
4894  IDecl = cast<ObjCCategoryDecl>(ClassDecl)->getClassInterface();
4895  // For valid code, we should always know the primary interface
4896  // declaration by now, however for invalid code we'll keep parsing
4897  // but we won't find the primary interface and IDecl will be nil.
4898  if (IDecl)
4899  checkObjCDirectMethodClashes(*this, IDecl, ObjCMethod);
4900  }
4901 
4902  cast<DeclContext>(ClassDecl)->addDecl(ObjCMethod);
4903  }
4904 
4905  if (PrevMethod) {
4906  // You can never have two method definitions with the same name.
4907  Diag(ObjCMethod->getLocation(), diag::err_duplicate_method_decl)
4908  << ObjCMethod->getDeclName();
4909  Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
4910  ObjCMethod->setInvalidDecl();
4911  return ObjCMethod;
4912  }
4913 
4914  // If this Objective-C method does not have a related result type, but we
4915  // are allowed to infer related result types, try to do so based on the
4916  // method family.
4917  ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
4918  if (!CurrentClass) {
4919  if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl))
4920  CurrentClass = Cat->getClassInterface();
4921  else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(ClassDecl))
4922  CurrentClass = Impl->getClassInterface();
4923  else if (ObjCCategoryImplDecl *CatImpl
4924  = dyn_cast<ObjCCategoryImplDecl>(ClassDecl))
4925  CurrentClass = CatImpl->getClassInterface();
4926  }
4927 
4929  = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
4930 
4931  CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC);
4932 
4933  bool ARCError = false;
4934  if (getLangOpts().ObjCAutoRefCount)
4935  ARCError = CheckARCMethodDecl(ObjCMethod);
4936 
4937  // Infer the related result type when possible.
4938  if (!ARCError && RTC == Sema::RTC_Compatible &&
4939  !ObjCMethod->hasRelatedResultType() &&
4940  LangOpts.ObjCInferRelatedResultType) {
4941  bool InferRelatedResultType = false;
4942  switch (ObjCMethod->getMethodFamily()) {
4943  case OMF_None:
4944  case OMF_copy:
4945  case OMF_dealloc:
4946  case OMF_finalize:
4947  case OMF_mutableCopy:
4948  case OMF_release:
4949  case OMF_retainCount:
4950  case OMF_initialize:
4951  case OMF_performSelector:
4952  break;
4953 
4954  case OMF_alloc:
4955  case OMF_new:
4956  InferRelatedResultType = ObjCMethod->isClassMethod();
4957  break;
4958 
4959  case OMF_init:
4960  case OMF_autorelease:
4961  case OMF_retain:
4962  case OMF_self:
4963  InferRelatedResultType = ObjCMethod->isInstanceMethod();
4964  break;
4965  }
4966 
4967  if (InferRelatedResultType &&
4968  !ObjCMethod->getReturnType()->isObjCIndependentClassType())
4969  ObjCMethod->setRelatedResultType();
4970  }
4971 
4972  if (MethodDefinition &&
4973  Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
4974  checkObjCMethodX86VectorTypes(*this, ObjCMethod);
4975 
4976  // + load method cannot have availability attributes. It get called on
4977  // startup, so it has to have the availability of the deployment target.
4978  if (const auto *attr = ObjCMethod->getAttr<AvailabilityAttr>()) {
4979  if (ObjCMethod->isClassMethod() &&
4980  ObjCMethod->getSelector().getAsString() == "load") {
4981  Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
4982  << 0;
4983  ObjCMethod->dropAttr<AvailabilityAttr>();
4984  }
4985  }
4986 
4987  // Insert the invisible arguments, self and _cmd!
4988  ObjCMethod->createImplicitParams(Context, ObjCMethod->getClassInterface());
4989 
4990  ActOnDocumentableDecl(ObjCMethod);
4991 
4992  return ObjCMethod;
4993 }
4994 
4996  // Following is also an error. But it is caused by a missing @end
4997  // and diagnostic is issued elsewhere.
4998  if (isa<ObjCContainerDecl>(CurContext->getRedeclContext()))
4999  return false;
5000 
5001  // If we switched context to translation unit while we are still lexically in
5002  // an objc container, it means the parser missed emitting an error.
5003  if (isa<TranslationUnitDecl>(getCurLexicalContext()->getRedeclContext()))
5004  return false;
5005 
5006  Diag(D->getLocation(), diag::err_objc_decls_may_only_appear_in_global_scope);
5007  D->setInvalidDecl();
5008 
5009  return true;
5010 }
5011 
5012 /// Called whenever \@defs(ClassName) is encountered in the source. Inserts the
5013 /// instance variables of ClassName into Decls.
5014 void Sema::ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
5015  IdentifierInfo *ClassName,
5016  SmallVectorImpl<Decl*> &Decls) {
5017  // Check that ClassName is a valid class
5018  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName, DeclStart);
5019  if (!Class) {
5020  Diag(DeclStart, diag::err_undef_interface) << ClassName;
5021  return;
5022  }
5024  Diag(DeclStart, diag::err_atdef_nonfragile_interface);
5025  return;
5026  }
5027 
5028  // Collect the instance variables
5030  Context.DeepCollectObjCIvars(Class, true, Ivars);
5031  // For each ivar, create a fresh ObjCAtDefsFieldDecl.
5032  for (unsigned i = 0; i < Ivars.size(); i++) {
5033  const FieldDecl* ID = Ivars[i];
5034  RecordDecl *Record = dyn_cast<RecordDecl>(TagD);
5035  Decl *FD = ObjCAtDefsFieldDecl::Create(Context, Record,
5036  /*FIXME: StartL=*/ID->getLocation(),
5037  ID->getLocation(),
5038  ID->getIdentifier(), ID->getType(),
5039  ID->getBitWidth());
5040  Decls.push_back(FD);
5041  }
5042 
5043  // Introduce all of these fields into the appropriate scope.
5044  for (SmallVectorImpl<Decl*>::iterator D = Decls.begin();
5045  D != Decls.end(); ++D) {
5046  FieldDecl *FD = cast<FieldDecl>(*D);
5047  if (getLangOpts().CPlusPlus)
5048  PushOnScopeChains(FD, S);
5049  else if (RecordDecl *Record = dyn_cast<RecordDecl>(TagD))
5050  Record->addDecl(FD);
5051  }
5052 }
5053 
5054 /// Build a type-check a new Objective-C exception variable declaration.
5056  SourceLocation StartLoc,
5057  SourceLocation IdLoc,
5058  IdentifierInfo *Id,
5059  bool Invalid) {
5060  // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
5061  // duration shall not be qualified by an address-space qualifier."
5062  // Since all parameters have automatic store duration, they can not have
5063  // an address space.
5064  if (T.getAddressSpace() != LangAS::Default) {
5065  Diag(IdLoc, diag::err_arg_with_address_space);
5066  Invalid = true;
5067  }
5068 
5069  // An @catch parameter must be an unqualified object pointer type;
5070  // FIXME: Recover from "NSObject foo" by inserting the * in "NSObject *foo"?
5071  if (Invalid) {
5072  // Don't do any further checking.
5073  } else if (T->isDependentType()) {
5074  // Okay: we don't know what this type will instantiate to.
5075  } else if (T->isObjCQualifiedIdType()) {
5076  Invalid = true;
5077  Diag(IdLoc, diag::err_illegal_qualifiers_on_catch_parm);
5078  } else if (T->isObjCIdType()) {
5079  // Okay: we don't know what this type will instantiate to.
5080  } else if (!T->isObjCObjectPointerType()) {
5081  Invalid = true;
5082  Diag(IdLoc, diag::err_catch_param_not_objc_type);
5083  } else if (!T->castAs<ObjCObjectPointerType>()->getInterfaceType()) {
5084  Invalid = true;
5085  Diag(IdLoc, diag::err_catch_param_not_objc_type);
5086  }
5087 
5088  VarDecl *New = VarDecl::Create(Context, CurContext, StartLoc, IdLoc, Id,
5089  T, TInfo, SC_None);
5090  New->setExceptionVariable(true);
5091 
5092  // In ARC, infer 'retaining' for variables of retainable type.
5093  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(New))
5094  Invalid = true;
5095 
5096  if (Invalid)
5097  New->setInvalidDecl();
5098  return New;
5099 }
5100 
5102  const DeclSpec &DS = D.getDeclSpec();
5103 
5104  // We allow the "register" storage class on exception variables because
5105  // GCC did, but we drop it completely. Any other storage class is an error.
5107  Diag(DS.getStorageClassSpecLoc(), diag::warn_register_objc_catch_parm)
5109  } else if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
5110  Diag(DS.getStorageClassSpecLoc(), diag::err_storage_spec_on_catch_parm)
5112  }
5113  if (DS.isInlineSpecified())
5114  Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
5115  << getLangOpts().CPlusPlus17;
5118  diag::err_invalid_thread)
5119  << DeclSpec::getSpecifierName(TSCS);
5121 
5123 
5124  // Check that there are no default arguments inside the type of this
5125  // exception object (C++ only).
5126  if (getLangOpts().CPlusPlus)
5128 
5129  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
5130  QualType ExceptionType = TInfo->getType();
5131 
5132  VarDecl *New = BuildObjCExceptionDecl(TInfo, ExceptionType,
5133  D.getSourceRange().getBegin(),
5134  D.getIdentifierLoc(),
5135  D.getIdentifier(),
5136  D.isInvalidType());
5137 
5138  // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
5139  if (D.getCXXScopeSpec().isSet()) {
5140  Diag(D.getIdentifierLoc(), diag::err_qualified_objc_catch_parm)
5141  << D.getCXXScopeSpec().getRange();
5142  New->setInvalidDecl();
5143  }
5144 
5145  // Add the parameter declaration into this scope.
5146  S->AddDecl(New);
5147  if (D.getIdentifier())
5148  IdResolver.AddDecl(New);
5149 
5150  ProcessDeclAttributes(S, New, D);
5151 
5152  if (New->hasAttr<BlocksAttr>())
5153  Diag(New->getLocation(), diag::err_block_on_nonlocal);
5154  return New;
5155 }
5156 
5157 /// CollectIvarsToConstructOrDestruct - Collect those ivars which require
5158 /// initialization.
5161  for (ObjCIvarDecl *Iv = OI->all_declared_ivar_begin(); Iv;
5162  Iv= Iv->getNextIvar()) {
5163  QualType QT = Context.getBaseElementType(Iv->getType());
5164  if (QT->isRecordType())
5165  Ivars.push_back(Iv);
5166  }
5167 }
5168 
5170  // Load referenced selectors from the external source.
5171  if (ExternalSource) {
5173  ExternalSource->ReadReferencedSelectors(Sels);
5174  for (unsigned I = 0, N = Sels.size(); I != N; ++I)
5175  ReferencedSelectors[Sels[I].first] = Sels[I].second;
5176  }
5177 
5178  // Warning will be issued only when selector table is
5179  // generated (which means there is at lease one implementation
5180  // in the TU). This is to match gcc's behavior.
5181  if (ReferencedSelectors.empty() ||
5182  !Context.AnyObjCImplementation())
5183  return;
5184  for (auto &SelectorAndLocation : ReferencedSelectors) {
5185  Selector Sel = SelectorAndLocation.first;
5186  SourceLocation Loc = SelectorAndLocation.second;
5188  Diag(Loc, diag::warn_unimplemented_selector) << Sel;
5189  }
5190 }
5191 
5192 ObjCIvarDecl *
5194  const ObjCPropertyDecl *&PDecl) const {
5195  if (Method->isClassMethod())
5196  return nullptr;
5197  const ObjCInterfaceDecl *IDecl = Method->getClassInterface();
5198  if (!IDecl)
5199  return nullptr;
5200  Method = IDecl->lookupMethod(Method->getSelector(), /*isInstance=*/true,
5201  /*shallowCategoryLookup=*/false,
5202  /*followSuper=*/false);
5203  if (!Method || !Method->isPropertyAccessor())
5204  return nullptr;
5205  if ((PDecl = Method->findPropertyDecl()))
5206  if (ObjCIvarDecl *IV = PDecl->getPropertyIvarDecl()) {
5207  // property backing ivar must belong to property's class
5208  // or be a private ivar in class's implementation.
5209  // FIXME. fix the const-ness issue.
5210  IV = const_cast<ObjCInterfaceDecl *>(IDecl)->lookupInstanceVariable(
5211  IV->getIdentifier());
5212  return IV;
5213  }
5214  return nullptr;
5215 }
5216 
5217 namespace {
5218  /// Used by Sema::DiagnoseUnusedBackingIvarInAccessor to check if a property
5219  /// accessor references the backing ivar.
5220  class UnusedBackingIvarChecker :
5221  public RecursiveASTVisitor<UnusedBackingIvarChecker> {
5222  public:
5223  Sema &S;
5224  const ObjCMethodDecl *Method;
5225  const ObjCIvarDecl *IvarD;
5226  bool AccessedIvar;
5227  bool InvokedSelfMethod;
5228 
5229  UnusedBackingIvarChecker(Sema &S, const ObjCMethodDecl *Method,
5230  const ObjCIvarDecl *IvarD)
5231  : S(S), Method(Method), IvarD(IvarD),
5232  AccessedIvar(false), InvokedSelfMethod(false) {
5233  assert(IvarD);
5234  }
5235 
5236  bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
5237  if (E->getDecl() == IvarD) {
5238  AccessedIvar = true;
5239  return false;
5240  }
5241  return true;
5242  }
5243 
5244  bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
5246  S.isSelfExpr(E->getInstanceReceiver(), Method)) {
5247  InvokedSelfMethod = true;
5248  }
5249  return true;
5250  }
5251  };
5252 } // end anonymous namespace
5253 
5255  const ObjCImplementationDecl *ImplD) {
5257  return;
5258 
5259  for (const auto *CurMethod : ImplD->instance_methods()) {
5260  unsigned DIAG = diag::warn_unused_property_backing_ivar;
5261  SourceLocation Loc = CurMethod->getLocation();
5262  if (Diags.isIgnored(DIAG, Loc))
5263  continue;
5264 
5265  const ObjCPropertyDecl *PDecl;
5266  const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
5267  if (!IV)
5268  continue;
5269 
5270  if (CurMethod->isSynthesizedAccessorStub())
5271  continue;
5272 
5273  UnusedBackingIvarChecker Checker(*this, CurMethod, IV);
5274  Checker.TraverseStmt(CurMethod->getBody());
5275  if (Checker.AccessedIvar)
5276  continue;
5277 
5278  // Do not issue this warning if backing ivar is used somewhere and accessor
5279  // implementation makes a self call. This is to prevent false positive in
5280  // cases where the ivar is accessed by another method that the accessor
5281  // delegates to.
5282  if (!IV->isReferenced() || !Checker.InvokedSelfMethod) {
5283  Diag(Loc, DIAG) << IV;
5284  Diag(PDecl->getLocation(), diag::note_property_declare);
5285  }
5286  }
5287 }
Decl * ActOnAtEnd(Scope *S, SourceRange AtEnd, ArrayRef< Decl *> allMethods=None, ArrayRef< DeclGroupPtrTy > allTUVars=None)
const ObjCInterfaceType * getInterfaceType() const
If this pointer points to an Objective C @interface type, gets the type for that interface.
Definition: Type.cpp:1675
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Defines the clang::ASTContext interface.
bool hasDefinition() const
Determine whether this class has been defined.
Definition: DeclObjC.h:1526
static bool tryMatchRecordTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy, const Type *left, const Type *right)
ObjCIvarDecl * GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method, const ObjCPropertyDecl *&PDecl) const
GetIvarBackingPropertyAccessor - If method is a property setter/getter and it property has a backing ...
void DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT, ObjCInterfaceDecl *ID)
DiagnoseClassExtensionDupMethods - Check for duplicate declaration of a class method in its extension...
bool isClassMethod() const
Definition: DeclObjC.h:432
Decl * ActOnStartCategoryInterface(SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName, SourceLocation ClassLoc, ObjCTypeParamList *typeParamList, IdentifierInfo *CategoryName, SourceLocation CategoryLoc, Decl *const *ProtoRefs, unsigned NumProtoRefs, const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc, const ParsedAttributesView &AttrList)
void setImplicit(bool I=true)
Definition: DeclBase.h:564
ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo)
Package the given type and TSI into a ParsedType.
Definition: SemaType.cpp:6192
bool isSelfExpr(Expr *RExpr)
Private Helper predicate to check for &#39;self&#39;.
The receiver is an object instance.
Definition: ExprObjC.h:1091
void setEndOfDefinitionLoc(SourceLocation LE)
Definition: DeclObjC.h:1876
VersionTuple getPlatformMinVersion() const
Retrieve the minimum desired version of the platform, to which the program should be compiled...
Definition: TargetInfo.h:1345
ExternalSemaSource * getExternalSource() const
Definition: Sema.h:1440
bool isObjCQualifiedIdType() const
True if this is equivalent to &#39;id.
Definition: Type.h:6125
Smart pointer class that efficiently represents Objective-C method names.
QualType getObjCIdType() const
Represents the Objective-CC id type.
Definition: ASTContext.h:1821
unsigned getBits() const
QualType getAdjustedParameterType(QualType T) const
Perform adjustment on the parameter type of a function.
void PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext, Decl *LambdaContextDecl=nullptr, ExpressionEvaluationContextRecord::ExpressionKind Type=ExpressionEvaluationContextRecord::EK_Other)
Definition: SemaExpr.cpp:16037
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2645
A (possibly-)qualified type.
Definition: Type.h:655
ASTConsumer & Consumer
Definition: Sema.h:400
Simple class containing the result of Sema::CorrectTypo.
void setStarLoc(SourceLocation Loc)
Definition: TypeLoc.h:1302
unsigned param_size() const
Definition: DeclObjC.h:343
ObjCInterfaceDecl * getClassInterface()
Definition: DeclObjC.h:2316
all_protocol_range all_referenced_protocols() const
Definition: DeclObjC.h:1415
ObjCInterfaceDecl * getClassInterface()
Definition: DeclObjC.cpp:1156
void startDefinition()
Starts the definition of this Objective-C class, taking it from a forward declaration (@class) to a d...
Definition: DeclObjC.cpp:611
bool AreMultipleMethodsInGlobalPool(Selector Sel, ObjCMethodDecl *BestMethod, SourceRange R, bool receiverIdOrClass, SmallVectorImpl< ObjCMethodDecl *> &Methods)
ObjCDeclQualifier getObjCDeclQualifier() const
Definition: DeclSpec.h:851
static QualType getObjectType(APValue::LValueBase B)
Retrieves the "underlying object type" of the given expression, as used by __builtin_object_size.
iterator begin() const
Definition: DeclObjC.h:91
llvm::DenseSet< IdentifierInfo * > ProtocolNameSet
FIXME: Type hierarchies in Objective-C can be deep.
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3633
bool LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation=false)
Perform unqualified name lookup starting from a given scope.
Look up the name of an Objective-C protocol.
Definition: Sema.h:3670
const ObjCProtocolList & getReferencedProtocols() const
Definition: DeclObjC.h:2340
Expr * getBitWidth() const
Definition: Decl.h:2835
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:627
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:1060
ObjCMethodDecl * LookupMethodInObjectType(Selector Sel, QualType Ty, bool IsInstance)
LookupMethodInType - Look up a method in an ObjCObjectType.
static bool CheckMethodOverrideParam(Sema &S, ObjCMethodDecl *MethodImpl, ObjCMethodDecl *MethodDecl, ParmVarDecl *ImplVar, ParmVarDecl *IfaceVar, bool IsProtocolMethodDecl, bool IsOverridingMode, bool Warn)
Defines the SourceManager interface.
void ActOnDocumentableDecl(Decl *D)
Should be called on all declarations that might have attached documentation comments.
Definition: SemaDecl.cpp:13282
bool isRecordType() const
Definition: Type.h:6740
iterator end()
Definition: DeclGroup.h:105
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1517
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:89
void DiagnoseMissingDesignatedInitOverrides(const ObjCImplementationDecl *ImplD, const ObjCInterfaceDecl *IFD)
__DEVICE__ long long abs(long long __n)
void ProcessDeclAttributeList(Scope *S, Decl *D, const ParsedAttributesView &AL, bool IncludeCXX11Attributes=true)
Captures information about "declaration specifiers" specific to Objective-C.
Definition: DeclSpec.h:827
ObjCTypeParamList * actOnObjCTypeParamList(Scope *S, SourceLocation lAngleLoc, ArrayRef< Decl *> typeParams, SourceLocation rAngleLoc)
void DiagnoseFunctionSpecifiers(const DeclSpec &DS)
Diagnose function specifiers on a declaration of an identifier that does not identify a function...
Definition: SemaDecl.cpp:6040
StringRef P
ivar_range ivars() const
Definition: DeclObjC.h:1449
Scope * TUScope
Translation Unit Scope - useful to Objective-C actions that need to lookup file scope declarations in...
Definition: Sema.h:996
static ObjCMethodDecl * Create(ASTContext &C, SourceLocation beginLoc, SourceLocation endLoc, Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo, DeclContext *contextDecl, bool isInstance=true, bool isVariadic=false, bool isPropertyAccessor=false, bool isSynthesizedAccessorStub=false, bool isImplicitlyDeclared=false, bool isDefined=false, ImplementationControl impControl=None, bool HasRelatedResultType=false)
Definition: DeclObjC.cpp:809
static ObjCProtocolDecl * Create(ASTContext &C, DeclContext *DC, IdentifierInfo *Id, SourceLocation nameLoc, SourceLocation atStartLoc, ObjCProtocolDecl *PrevDecl)
Definition: DeclObjC.cpp:1880
static bool NestedProtocolHasNoDefinition(ObjCProtocolDecl *PDecl, ObjCProtocolDecl *&UndefinedProtocol)
known_categories_range known_categories() const
Definition: DeclObjC.h:1678
ObjCTypeParamList * getTypeParamList() const
Retrieve the type parameters of this class.
Definition: DeclObjC.cpp:308
void AddDecl(Decl *D)
Definition: Scope.h:289
bool CheckForwardProtocolDeclarationForCircularDependency(IdentifierInfo *PName, SourceLocation &PLoc, SourceLocation PrevLoc, const ObjCList< ObjCProtocolDecl > &PList)
The base class of the type hierarchy.
Definition: Type.h:1472
void AddFactoryMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false)
AddFactoryMethodToGlobalPool - Same as above, but for factory methods.
Definition: Sema.h:4230
The parameter is covariant, e.g., X<T> is a subtype of X<U> when the type parameter is covariant and ...
CanQual< T > getUnqualifiedType() const
Retrieve the unqualified form of this type.
bool isCompilingModule() const
Are we compiling a module interface (.cppm or module map)?
Definition: LangOptions.h:310
bool isObjCContainer() const
Definition: DeclBase.h:1855
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset=0)
Calls Lexer::getLocForEndOfToken()
Definition: Sema.cpp:51
const ObjCObjectPointerType * getAsObjCInterfacePointerType() const
Definition: Type.cpp:1735
static const char * getSpecifierName(DeclSpec::TST T, const PrintingPolicy &Policy)
Turn a type-specifier-type into a string like "_Bool" or "union".
Definition: DeclSpec.cpp:531
SourceLocation getEndLoc() const LLVM_READONLY
Definition: DeclBase.h:426
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:647
A container of type source information.
Definition: Type.h:6373
void ProcessPropertyDecl(ObjCPropertyDecl *property)
Process the specified property declaration and create decls for the setters and getters as needed...
ObjCMethodDecl * getMethod() const