SemaDeclObjC.cpp revision 1e4691b9d8e1bdcc8ef62b323969d702c51b3c08 
1//===--- SemaDeclObjC.cpp - Semantic Analysis for ObjC Declarations -------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements semantic analysis for Objective C declarations.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/SemaInternal.h"
15#include "clang/Sema/Lookup.h"
16#include "clang/Sema/ExternalSemaSource.h"
17#include "clang/Sema/Scope.h"
18#include "clang/Sema/ScopeInfo.h"
19#include "clang/AST/ASTConsumer.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ExprObjC.h"
22#include "clang/AST/ASTContext.h"
23#include "clang/AST/DeclObjC.h"
24#include "clang/AST/ASTMutationListener.h"
25#include "clang/Basic/SourceManager.h"
26#include "clang/Sema/DeclSpec.h"
27#include "clang/Lex/Preprocessor.h"
28#include "llvm/ADT/DenseSet.h"
29
30using namespace clang;
31
32/// Check whether the given method, which must be in the 'init'
33/// family, is a valid member of that family.
34///
35/// \param receiverTypeIfCall - if null, check this as if declaring it;
36///   if non-null, check this as if making a call to it with the given
37///   receiver type
38///
39/// \return true to indicate that there was an error and appropriate
40///   actions were taken
41bool Sema::checkInitMethod(ObjCMethodDecl *method,
42                           QualType receiverTypeIfCall) {
43  if (method->isInvalidDecl()) return true;
44
45  // This castAs is safe: methods that don't return an object
46  // pointer won't be inferred as inits and will reject an explicit
47  // objc_method_family(init).
48
49  // We ignore protocols here.  Should we?  What about Class?
50
51  const ObjCObjectType *result = method->getResultType()
52    ->castAs<ObjCObjectPointerType>()->getObjectType();
53
54  if (result->isObjCId()) {
55    return false;
56  } else if (result->isObjCClass()) {
57    // fall through: always an error
58  } else {
59    ObjCInterfaceDecl *resultClass = result->getInterface();
60    assert(resultClass && "unexpected object type!");
61
62    // It's okay for the result type to still be a forward declaration
63    // if we're checking an interface declaration.
64    if (!resultClass->hasDefinition()) {
65      if (receiverTypeIfCall.isNull() &&
66          !isa<ObjCImplementationDecl>(method->getDeclContext()))
67        return false;
68
69    // Otherwise, we try to compare class types.
70    } else {
71      // If this method was declared in a protocol, we can't check
72      // anything unless we have a receiver type that's an interface.
73      const ObjCInterfaceDecl *receiverClass = 0;
74      if (isa<ObjCProtocolDecl>(method->getDeclContext())) {
75        if (receiverTypeIfCall.isNull())
76          return false;
77
78        receiverClass = receiverTypeIfCall->castAs<ObjCObjectPointerType>()
79          ->getInterfaceDecl();
80
81        // This can be null for calls to e.g. id<Foo>.
82        if (!receiverClass) return false;
83      } else {
84        receiverClass = method->getClassInterface();
85        assert(receiverClass && "method not associated with a class!");
86      }
87
88      // If either class is a subclass of the other, it's fine.
89      if (receiverClass->isSuperClassOf(resultClass) ||
90          resultClass->isSuperClassOf(receiverClass))
91        return false;
92    }
93  }
94
95  SourceLocation loc = method->getLocation();
96
97  // If we're in a system header, and this is not a call, just make
98  // the method unusable.
99  if (receiverTypeIfCall.isNull() && getSourceManager().isInSystemHeader(loc)) {
100    method->addAttr(new (Context) UnavailableAttr(loc, Context,
101                "init method returns a type unrelated to its receiver type"));
102    return true;
103  }
104
105  // Otherwise, it's an error.
106  Diag(loc, diag::err_arc_init_method_unrelated_result_type);
107  method->setInvalidDecl();
108  return true;
109}
110
111void Sema::CheckObjCMethodOverride(ObjCMethodDecl *NewMethod,
112                                   const ObjCMethodDecl *Overridden,
113                                   bool IsImplementation) {
114  if (Overridden->hasRelatedResultType() &&
115      !NewMethod->hasRelatedResultType()) {
116    // This can only happen when the method follows a naming convention that
117    // implies a related result type, and the original (overridden) method has
118    // a suitable return type, but the new (overriding) method does not have
119    // a suitable return type.
120    QualType ResultType = NewMethod->getResultType();
121    SourceRange ResultTypeRange;
122    if (const TypeSourceInfo *ResultTypeInfo
123                                        = NewMethod->getResultTypeSourceInfo())
124      ResultTypeRange = ResultTypeInfo->getTypeLoc().getSourceRange();
125
126    // Figure out which class this method is part of, if any.
127    ObjCInterfaceDecl *CurrentClass
128      = dyn_cast<ObjCInterfaceDecl>(NewMethod->getDeclContext());
129    if (!CurrentClass) {
130      DeclContext *DC = NewMethod->getDeclContext();
131      if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(DC))
132        CurrentClass = Cat->getClassInterface();
133      else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(DC))
134        CurrentClass = Impl->getClassInterface();
135      else if (ObjCCategoryImplDecl *CatImpl
136               = dyn_cast<ObjCCategoryImplDecl>(DC))
137        CurrentClass = CatImpl->getClassInterface();
138    }
139
140    if (CurrentClass) {
141      Diag(NewMethod->getLocation(),
142           diag::warn_related_result_type_compatibility_class)
143        << Context.getObjCInterfaceType(CurrentClass)
144        << ResultType
145        << ResultTypeRange;
146    } else {
147      Diag(NewMethod->getLocation(),
148           diag::warn_related_result_type_compatibility_protocol)
149        << ResultType
150        << ResultTypeRange;
151    }
152
153    if (ObjCMethodFamily Family = Overridden->getMethodFamily())
154      Diag(Overridden->getLocation(),
155           diag::note_related_result_type_overridden_family)
156        << Family;
157    else
158      Diag(Overridden->getLocation(),
159           diag::note_related_result_type_overridden);
160  }
161  if (getLangOpts().ObjCAutoRefCount) {
162    if ((NewMethod->hasAttr<NSReturnsRetainedAttr>() !=
163         Overridden->hasAttr<NSReturnsRetainedAttr>())) {
164        Diag(NewMethod->getLocation(),
165             diag::err_nsreturns_retained_attribute_mismatch) << 1;
166        Diag(Overridden->getLocation(), diag::note_previous_decl)
167        << "method";
168    }
169    if ((NewMethod->hasAttr<NSReturnsNotRetainedAttr>() !=
170              Overridden->hasAttr<NSReturnsNotRetainedAttr>())) {
171        Diag(NewMethod->getLocation(),
172             diag::err_nsreturns_retained_attribute_mismatch) << 0;
173        Diag(Overridden->getLocation(), diag::note_previous_decl)
174        << "method";
175    }
176    ObjCMethodDecl::param_const_iterator oi = Overridden->param_begin(),
177                                         oe = Overridden->param_end();
178    for (ObjCMethodDecl::param_iterator
179           ni = NewMethod->param_begin(), ne = NewMethod->param_end();
180         ni != ne && oi != oe; ++ni, ++oi) {
181      const ParmVarDecl *oldDecl = (*oi);
182      ParmVarDecl *newDecl = (*ni);
183      if (newDecl->hasAttr<NSConsumedAttr>() !=
184          oldDecl->hasAttr<NSConsumedAttr>()) {
185        Diag(newDecl->getLocation(),
186             diag::err_nsconsumed_attribute_mismatch);
187        Diag(oldDecl->getLocation(), diag::note_previous_decl)
188          << "parameter";
189      }
190    }
191  }
192}
193
194/// \brief Check a method declaration for compatibility with the Objective-C
195/// ARC conventions.
196static bool CheckARCMethodDecl(Sema &S, ObjCMethodDecl *method) {
197  ObjCMethodFamily family = method->getMethodFamily();
198  switch (family) {
199  case OMF_None:
200  case OMF_finalize:
201  case OMF_retain:
202  case OMF_release:
203  case OMF_autorelease:
204  case OMF_retainCount:
205  case OMF_self:
206  case OMF_performSelector:
207    return false;
208
209  case OMF_dealloc:
210    if (!S.Context.hasSameType(method->getResultType(), S.Context.VoidTy)) {
211      SourceRange ResultTypeRange;
212      if (const TypeSourceInfo *ResultTypeInfo
213          = method->getResultTypeSourceInfo())
214        ResultTypeRange = ResultTypeInfo->getTypeLoc().getSourceRange();
215      if (ResultTypeRange.isInvalid())
216        S.Diag(method->getLocation(), diag::error_dealloc_bad_result_type)
217          << method->getResultType()
218          << FixItHint::CreateInsertion(method->getSelectorLoc(0), "(void)");
219      else
220        S.Diag(method->getLocation(), diag::error_dealloc_bad_result_type)
221          << method->getResultType()
222          << FixItHint::CreateReplacement(ResultTypeRange, "void");
223      return true;
224    }
225    return false;
226
227  case OMF_init:
228    // If the method doesn't obey the init rules, don't bother annotating it.
229    if (S.checkInitMethod(method, QualType()))
230      return true;
231
232    method->addAttr(new (S.Context) NSConsumesSelfAttr(SourceLocation(),
233                                                       S.Context));
234
235    // Don't add a second copy of this attribute, but otherwise don't
236    // let it be suppressed.
237    if (method->hasAttr<NSReturnsRetainedAttr>())
238      return false;
239    break;
240
241  case OMF_alloc:
242  case OMF_copy:
243  case OMF_mutableCopy:
244  case OMF_new:
245    if (method->hasAttr<NSReturnsRetainedAttr>() ||
246        method->hasAttr<NSReturnsNotRetainedAttr>() ||
247        method->hasAttr<NSReturnsAutoreleasedAttr>())
248      return false;
249    break;
250  }
251
252  method->addAttr(new (S.Context) NSReturnsRetainedAttr(SourceLocation(),
253                                                        S.Context));
254  return false;
255}
256
257static void DiagnoseObjCImplementedDeprecations(Sema &S,
258                                                NamedDecl *ND,
259                                                SourceLocation ImplLoc,
260                                                int select) {
261  if (ND && ND->isDeprecated()) {
262    S.Diag(ImplLoc, diag::warn_deprecated_def) << select;
263    if (select == 0)
264      S.Diag(ND->getLocation(), diag::note_method_declared_at)
265        << ND->getDeclName();
266    else
267      S.Diag(ND->getLocation(), diag::note_previous_decl) << "class";
268  }
269}
270
271/// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
272/// pool.
273void Sema::AddAnyMethodToGlobalPool(Decl *D) {
274  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
275
276  // If we don't have a valid method decl, simply return.
277  if (!MDecl)
278    return;
279  if (MDecl->isInstanceMethod())
280    AddInstanceMethodToGlobalPool(MDecl, true);
281  else
282    AddFactoryMethodToGlobalPool(MDecl, true);
283}
284
285/// HasExplicitOwnershipAttr - returns true when pointer to ObjC pointer
286/// has explicit ownership attribute; false otherwise.
287static bool
288HasExplicitOwnershipAttr(Sema &S, ParmVarDecl *Param) {
289  QualType T = Param->getType();
290
291  if (const PointerType *PT = T->getAs<PointerType>()) {
292    T = PT->getPointeeType();
293  } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
294    T = RT->getPointeeType();
295  } else {
296    return true;
297  }
298
299  // If we have a lifetime qualifier, but it's local, we must have
300  // inferred it. So, it is implicit.
301  return !T.getLocalQualifiers().hasObjCLifetime();
302}
303
304/// ActOnStartOfObjCMethodDef - This routine sets up parameters; invisible
305/// and user declared, in the method definition's AST.
306void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, Decl *D) {
307  assert((getCurMethodDecl() == 0) && "Methodparsing confused");
308  ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
309
310  // If we don't have a valid method decl, simply return.
311  if (!MDecl)
312    return;
313
314  // Allow all of Sema to see that we are entering a method definition.
315  PushDeclContext(FnBodyScope, MDecl);
316  PushFunctionScope();
317
318  // Create Decl objects for each parameter, entrring them in the scope for
319  // binding to their use.
320
321  // Insert the invisible arguments, self and _cmd!
322  MDecl->createImplicitParams(Context, MDecl->getClassInterface());
323
324  PushOnScopeChains(MDecl->getSelfDecl(), FnBodyScope);
325  PushOnScopeChains(MDecl->getCmdDecl(), FnBodyScope);
326
327  // Introduce all of the other parameters into this scope.
328  for (ObjCMethodDecl::param_iterator PI = MDecl->param_begin(),
329       E = MDecl->param_end(); PI != E; ++PI) {
330    ParmVarDecl *Param = (*PI);
331    if (!Param->isInvalidDecl() &&
332        RequireCompleteType(Param->getLocation(), Param->getType(),
333                            diag::err_typecheck_decl_incomplete_type))
334          Param->setInvalidDecl();
335    if (!Param->isInvalidDecl() &&
336        getLangOpts().ObjCAutoRefCount &&
337        !HasExplicitOwnershipAttr(*this, Param))
338      Diag(Param->getLocation(), diag::warn_arc_strong_pointer_objc_pointer) <<
339            Param->getType();
340
341    if ((*PI)->getIdentifier())
342      PushOnScopeChains(*PI, FnBodyScope);
343  }
344
345  // In ARC, disallow definition of retain/release/autorelease/retainCount
346  if (getLangOpts().ObjCAutoRefCount) {
347    switch (MDecl->getMethodFamily()) {
348    case OMF_retain:
349    case OMF_retainCount:
350    case OMF_release:
351    case OMF_autorelease:
352      Diag(MDecl->getLocation(), diag::err_arc_illegal_method_def)
353        << MDecl->getSelector();
354      break;
355
356    case OMF_None:
357    case OMF_dealloc:
358    case OMF_finalize:
359    case OMF_alloc:
360    case OMF_init:
361    case OMF_mutableCopy:
362    case OMF_copy:
363    case OMF_new:
364    case OMF_self:
365    case OMF_performSelector:
366      break;
367    }
368  }
369
370  // Warn on deprecated methods under -Wdeprecated-implementations,
371  // and prepare for warning on missing super calls.
372  if (ObjCInterfaceDecl *IC = MDecl->getClassInterface()) {
373    ObjCMethodDecl *IMD =
374      IC->lookupMethod(MDecl->getSelector(), MDecl->isInstanceMethod());
375
376    if (IMD)
377      DiagnoseObjCImplementedDeprecations(*this,
378                                          dyn_cast<NamedDecl>(IMD),
379                                          MDecl->getLocation(), 0);
380
381    // If this is "dealloc" or "finalize", set some bit here.
382    // Then in ActOnSuperMessage() (SemaExprObjC), set it back to false.
383    // Finally, in ActOnFinishFunctionBody() (SemaDecl), warn if flag is set.
384    // Only do this if the current class actually has a superclass.
385    if (IC->getSuperClass()) {
386      getCurFunction()->ObjCShouldCallSuperDealloc =
387        !(Context.getLangOpts().ObjCAutoRefCount ||
388          Context.getLangOpts().getGC() == LangOptions::GCOnly) &&
389          MDecl->getMethodFamily() == OMF_dealloc;
390      if (!getCurFunction()->ObjCShouldCallSuperDealloc) {
391        IMD = IC->getSuperClass()->lookupMethod(MDecl->getSelector(),
392                                                MDecl->isInstanceMethod());
393        getCurFunction()->ObjCShouldCallSuperDealloc =
394          (IMD && IMD->hasAttr<ObjCRequiresSuperAttr>());
395      }
396      getCurFunction()->ObjCShouldCallSuperFinalize =
397        Context.getLangOpts().getGC() != LangOptions::NonGC &&
398        MDecl->getMethodFamily() == OMF_finalize;
399    }
400  }
401}
402
403namespace {
404
405// Callback to only accept typo corrections that are Objective-C classes.
406// If an ObjCInterfaceDecl* is given to the constructor, then the validation
407// function will reject corrections to that class.
408class ObjCInterfaceValidatorCCC : public CorrectionCandidateCallback {
409 public:
410  ObjCInterfaceValidatorCCC() : CurrentIDecl(0) {}
411  explicit ObjCInterfaceValidatorCCC(ObjCInterfaceDecl *IDecl)
412      : CurrentIDecl(IDecl) {}
413
414  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
415    ObjCInterfaceDecl *ID = candidate.getCorrectionDeclAs<ObjCInterfaceDecl>();
416    return ID && !declaresSameEntity(ID, CurrentIDecl);
417  }
418
419 private:
420  ObjCInterfaceDecl *CurrentIDecl;
421};
422
423}
424
425Decl *Sema::
426ActOnStartClassInterface(SourceLocation AtInterfaceLoc,
427                         IdentifierInfo *ClassName, SourceLocation ClassLoc,
428                         IdentifierInfo *SuperName, SourceLocation SuperLoc,
429                         Decl * const *ProtoRefs, unsigned NumProtoRefs,
430                         const SourceLocation *ProtoLocs,
431                         SourceLocation EndProtoLoc, AttributeList *AttrList) {
432  assert(ClassName && "Missing class identifier");
433
434  // Check for another declaration kind with the same name.
435  NamedDecl *PrevDecl = LookupSingleName(TUScope, ClassName, ClassLoc,
436                                         LookupOrdinaryName, ForRedeclaration);
437
438  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
439    Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
440    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
441  }
442
443  // Create a declaration to describe this @interface.
444  ObjCInterfaceDecl* PrevIDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
445  ObjCInterfaceDecl *IDecl
446    = ObjCInterfaceDecl::Create(Context, CurContext, AtInterfaceLoc, ClassName,
447                                PrevIDecl, ClassLoc);
448
449  if (PrevIDecl) {
450    // Class already seen. Was it a definition?
451    if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) {
452      Diag(AtInterfaceLoc, diag::err_duplicate_class_def)
453        << PrevIDecl->getDeclName();
454      Diag(Def->getLocation(), diag::note_previous_definition);
455      IDecl->setInvalidDecl();
456    }
457  }
458
459  if (AttrList)
460    ProcessDeclAttributeList(TUScope, IDecl, AttrList);
461  PushOnScopeChains(IDecl, TUScope);
462
463  // Start the definition of this class. If we're in a redefinition case, there
464  // may already be a definition, so we'll end up adding to it.
465  if (!IDecl->hasDefinition())
466    IDecl->startDefinition();
467
468  if (SuperName) {
469    // Check if a different kind of symbol declared in this scope.
470    PrevDecl = LookupSingleName(TUScope, SuperName, SuperLoc,
471                                LookupOrdinaryName);
472
473    if (!PrevDecl) {
474      // Try to correct for a typo in the superclass name without correcting
475      // to the class we're defining.
476      ObjCInterfaceValidatorCCC Validator(IDecl);
477      if (TypoCorrection Corrected = CorrectTypo(
478          DeclarationNameInfo(SuperName, SuperLoc), LookupOrdinaryName, TUScope,
479          NULL, Validator)) {
480        PrevDecl = Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>();
481        Diag(SuperLoc, diag::err_undef_superclass_suggest)
482          << SuperName << ClassName << PrevDecl->getDeclName();
483        Diag(PrevDecl->getLocation(), diag::note_previous_decl)
484          << PrevDecl->getDeclName();
485      }
486    }
487
488    if (declaresSameEntity(PrevDecl, IDecl)) {
489      Diag(SuperLoc, diag::err_recursive_superclass)
490        << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
491      IDecl->setEndOfDefinitionLoc(ClassLoc);
492    } else {
493      ObjCInterfaceDecl *SuperClassDecl =
494                                dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
495
496      // Diagnose classes that inherit from deprecated classes.
497      if (SuperClassDecl)
498        (void)DiagnoseUseOfDecl(SuperClassDecl, SuperLoc);
499
500      if (PrevDecl && SuperClassDecl == 0) {
501        // The previous declaration was not a class decl. Check if we have a
502        // typedef. If we do, get the underlying class type.
503        if (const TypedefNameDecl *TDecl =
504              dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) {
505          QualType T = TDecl->getUnderlyingType();
506          if (T->isObjCObjectType()) {
507            if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface())
508              SuperClassDecl = dyn_cast<ObjCInterfaceDecl>(IDecl);
509          }
510        }
511
512        // This handles the following case:
513        //
514        // typedef int SuperClass;
515        // @interface MyClass : SuperClass {} @end
516        //
517        if (!SuperClassDecl) {
518          Diag(SuperLoc, diag::err_redefinition_different_kind) << SuperName;
519          Diag(PrevDecl->getLocation(), diag::note_previous_definition);
520        }
521      }
522
523      if (!dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) {
524        if (!SuperClassDecl)
525          Diag(SuperLoc, diag::err_undef_superclass)
526            << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
527        else if (RequireCompleteType(SuperLoc,
528                                  Context.getObjCInterfaceType(SuperClassDecl),
529                                     diag::err_forward_superclass,
530                                     SuperClassDecl->getDeclName(),
531                                     ClassName,
532                                     SourceRange(AtInterfaceLoc, ClassLoc))) {
533          SuperClassDecl = 0;
534        }
535      }
536      IDecl->setSuperClass(SuperClassDecl);
537      IDecl->setSuperClassLoc(SuperLoc);
538      IDecl->setEndOfDefinitionLoc(SuperLoc);
539    }
540  } else { // we have a root class.
541    IDecl->setEndOfDefinitionLoc(ClassLoc);
542  }
543
544  // Check then save referenced protocols.
545  if (NumProtoRefs) {
546    IDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
547                           ProtoLocs, Context);
548    IDecl->setEndOfDefinitionLoc(EndProtoLoc);
549  }
550
551  CheckObjCDeclScope(IDecl);
552  return ActOnObjCContainerStartDefinition(IDecl);
553}
554
555/// ActOnCompatibilityAlias - this action is called after complete parsing of
556/// a \@compatibility_alias declaration. It sets up the alias relationships.
557Decl *Sema::ActOnCompatibilityAlias(SourceLocation AtLoc,
558                                    IdentifierInfo *AliasName,
559                                    SourceLocation AliasLocation,
560                                    IdentifierInfo *ClassName,
561                                    SourceLocation ClassLocation) {
562  // Look for previous declaration of alias name
563  NamedDecl *ADecl = LookupSingleName(TUScope, AliasName, AliasLocation,
564                                      LookupOrdinaryName, ForRedeclaration);
565  if (ADecl) {
566    if (isa<ObjCCompatibleAliasDecl>(ADecl))
567      Diag(AliasLocation, diag::warn_previous_alias_decl);
568    else
569      Diag(AliasLocation, diag::err_conflicting_aliasing_type) << AliasName;
570    Diag(ADecl->getLocation(), diag::note_previous_declaration);
571    return 0;
572  }
573  // Check for class declaration
574  NamedDecl *CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation,
575                                       LookupOrdinaryName, ForRedeclaration);
576  if (const TypedefNameDecl *TDecl =
577        dyn_cast_or_null<TypedefNameDecl>(CDeclU)) {
578    QualType T = TDecl->getUnderlyingType();
579    if (T->isObjCObjectType()) {
580      if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface()) {
581        ClassName = IDecl->getIdentifier();
582        CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation,
583                                  LookupOrdinaryName, ForRedeclaration);
584      }
585    }
586  }
587  ObjCInterfaceDecl *CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDeclU);
588  if (CDecl == 0) {
589    Diag(ClassLocation, diag::warn_undef_interface) << ClassName;
590    if (CDeclU)
591      Diag(CDeclU->getLocation(), diag::note_previous_declaration);
592    return 0;
593  }
594
595  // Everything checked out, instantiate a new alias declaration AST.
596  ObjCCompatibleAliasDecl *AliasDecl =
597    ObjCCompatibleAliasDecl::Create(Context, CurContext, AtLoc, AliasName, CDecl);
598
599  if (!CheckObjCDeclScope(AliasDecl))
600    PushOnScopeChains(AliasDecl, TUScope);
601
602  return AliasDecl;
603}
604
605bool Sema::CheckForwardProtocolDeclarationForCircularDependency(
606  IdentifierInfo *PName,
607  SourceLocation &Ploc, SourceLocation PrevLoc,
608  const ObjCList<ObjCProtocolDecl> &PList) {
609
610  bool res = false;
611  for (ObjCList<ObjCProtocolDecl>::iterator I = PList.begin(),
612       E = PList.end(); I != E; ++I) {
613    if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier(),
614                                                 Ploc)) {
615      if (PDecl->getIdentifier() == PName) {
616        Diag(Ploc, diag::err_protocol_has_circular_dependency);
617        Diag(PrevLoc, diag::note_previous_definition);
618        res = true;
619      }
620
621      if (!PDecl->hasDefinition())
622        continue;
623
624      if (CheckForwardProtocolDeclarationForCircularDependency(PName, Ploc,
625            PDecl->getLocation(), PDecl->getReferencedProtocols()))
626        res = true;
627    }
628  }
629  return res;
630}
631
632Decl *
633Sema::ActOnStartProtocolInterface(SourceLocation AtProtoInterfaceLoc,
634                                  IdentifierInfo *ProtocolName,
635                                  SourceLocation ProtocolLoc,
636                                  Decl * const *ProtoRefs,
637                                  unsigned NumProtoRefs,
638                                  const SourceLocation *ProtoLocs,
639                                  SourceLocation EndProtoLoc,
640                                  AttributeList *AttrList) {
641  bool err = false;
642  // FIXME: Deal with AttrList.
643  assert(ProtocolName && "Missing protocol identifier");
644  ObjCProtocolDecl *PrevDecl = LookupProtocol(ProtocolName, ProtocolLoc,
645                                              ForRedeclaration);
646  ObjCProtocolDecl *PDecl = 0;
647  if (ObjCProtocolDecl *Def = PrevDecl? PrevDecl->getDefinition() : 0) {
648    // If we already have a definition, complain.
649    Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName;
650    Diag(Def->getLocation(), diag::note_previous_definition);
651
652    // Create a new protocol that is completely distinct from previous
653    // declarations, and do not make this protocol available for name lookup.
654    // That way, we'll end up completely ignoring the duplicate.
655    // FIXME: Can we turn this into an error?
656    PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
657                                     ProtocolLoc, AtProtoInterfaceLoc,
658                                     /*PrevDecl=*/0);
659    PDecl->startDefinition();
660  } else {
661    if (PrevDecl) {
662      // Check for circular dependencies among protocol declarations. This can
663      // only happen if this protocol was forward-declared.
664      ObjCList<ObjCProtocolDecl> PList;
665      PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context);
666      err = CheckForwardProtocolDeclarationForCircularDependency(
667              ProtocolName, ProtocolLoc, PrevDecl->getLocation(), PList);
668    }
669
670    // Create the new declaration.
671    PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName,
672                                     ProtocolLoc, AtProtoInterfaceLoc,
673                                     /*PrevDecl=*/PrevDecl);
674
675    PushOnScopeChains(PDecl, TUScope);
676    PDecl->startDefinition();
677  }
678
679  if (AttrList)
680    ProcessDeclAttributeList(TUScope, PDecl, AttrList);
681
682  // Merge attributes from previous declarations.
683  if (PrevDecl)
684    mergeDeclAttributes(PDecl, PrevDecl);
685
686  if (!err && NumProtoRefs ) {
687    /// Check then save referenced protocols.
688    PDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
689                           ProtoLocs, Context);
690  }
691
692  CheckObjCDeclScope(PDecl);
693  return ActOnObjCContainerStartDefinition(PDecl);
694}
695
696/// FindProtocolDeclaration - This routine looks up protocols and
697/// issues an error if they are not declared. It returns list of
698/// protocol declarations in its 'Protocols' argument.
699void
700Sema::FindProtocolDeclaration(bool WarnOnDeclarations,
701                              const IdentifierLocPair *ProtocolId,
702                              unsigned NumProtocols,
703                              SmallVectorImpl<Decl *> &Protocols) {
704  for (unsigned i = 0; i != NumProtocols; ++i) {
705    ObjCProtocolDecl *PDecl = LookupProtocol(ProtocolId[i].first,
706                                             ProtocolId[i].second);
707    if (!PDecl) {
708      DeclFilterCCC<ObjCProtocolDecl> Validator;
709      TypoCorrection Corrected = CorrectTypo(
710          DeclarationNameInfo(ProtocolId[i].first, ProtocolId[i].second),
711          LookupObjCProtocolName, TUScope, NULL, Validator);
712      if ((PDecl = Corrected.getCorrectionDeclAs<ObjCProtocolDecl>())) {
713        Diag(ProtocolId[i].second, diag::err_undeclared_protocol_suggest)
714          << ProtocolId[i].first << Corrected.getCorrection();
715        Diag(PDecl->getLocation(), diag::note_previous_decl)
716          << PDecl->getDeclName();
717      }
718    }
719
720    if (!PDecl) {
721      Diag(ProtocolId[i].second, diag::err_undeclared_protocol)
722        << ProtocolId[i].first;
723      continue;
724    }
725
726    (void)DiagnoseUseOfDecl(PDecl, ProtocolId[i].second);
727
728    // If this is a forward declaration and we are supposed to warn in this
729    // case, do it.
730    if (WarnOnDeclarations && !PDecl->hasDefinition())
731      Diag(ProtocolId[i].second, diag::warn_undef_protocolref)
732        << ProtocolId[i].first;
733    Protocols.push_back(PDecl);
734  }
735}
736
737/// DiagnoseClassExtensionDupMethods - Check for duplicate declaration of
738/// a class method in its extension.
739///
740void Sema::DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT,
741                                            ObjCInterfaceDecl *ID) {
742  if (!ID)
743    return;  // Possibly due to previous error
744
745  llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap;
746  for (ObjCInterfaceDecl::method_iterator i = ID->meth_begin(),
747       e =  ID->meth_end(); i != e; ++i) {
748    ObjCMethodDecl *MD = *i;
749    MethodMap[MD->getSelector()] = MD;
750  }
751
752  if (MethodMap.empty())
753    return;
754  for (ObjCCategoryDecl::method_iterator i = CAT->meth_begin(),
755       e =  CAT->meth_end(); i != e; ++i) {
756    ObjCMethodDecl *Method = *i;
757    const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()];
758    if (PrevMethod && !MatchTwoMethodDeclarations(Method, PrevMethod)) {
759      Diag(Method->getLocation(), diag::err_duplicate_method_decl)
760            << Method->getDeclName();
761      Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
762    }
763  }
764}
765
766/// ActOnForwardProtocolDeclaration - Handle \@protocol foo;
767Sema::DeclGroupPtrTy
768Sema::ActOnForwardProtocolDeclaration(SourceLocation AtProtocolLoc,
769                                      const IdentifierLocPair *IdentList,
770                                      unsigned NumElts,
771                                      AttributeList *attrList) {
772  SmallVector<Decl *, 8> DeclsInGroup;
773  for (unsigned i = 0; i != NumElts; ++i) {
774    IdentifierInfo *Ident = IdentList[i].first;
775    ObjCProtocolDecl *PrevDecl = LookupProtocol(Ident, IdentList[i].second,
776                                                ForRedeclaration);
777    ObjCProtocolDecl *PDecl
778      = ObjCProtocolDecl::Create(Context, CurContext, Ident,
779                                 IdentList[i].second, AtProtocolLoc,
780                                 PrevDecl);
781
782    PushOnScopeChains(PDecl, TUScope);
783    CheckObjCDeclScope(PDecl);
784
785    if (attrList)
786      ProcessDeclAttributeList(TUScope, PDecl, attrList);
787
788    if (PrevDecl)
789      mergeDeclAttributes(PDecl, PrevDecl);
790
791    DeclsInGroup.push_back(PDecl);
792  }
793
794  return BuildDeclaratorGroup(DeclsInGroup.data(), DeclsInGroup.size(), false);
795}
796
797Decl *Sema::
798ActOnStartCategoryInterface(SourceLocation AtInterfaceLoc,
799                            IdentifierInfo *ClassName, SourceLocation ClassLoc,
800                            IdentifierInfo *CategoryName,
801                            SourceLocation CategoryLoc,
802                            Decl * const *ProtoRefs,
803                            unsigned NumProtoRefs,
804                            const SourceLocation *ProtoLocs,
805                            SourceLocation EndProtoLoc) {
806  ObjCCategoryDecl *CDecl;
807  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
808
809  /// Check that class of this category is already completely declared.
810
811  if (!IDecl
812      || RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
813                             diag::err_category_forward_interface,
814                             CategoryName == 0)) {
815    // Create an invalid ObjCCategoryDecl to serve as context for
816    // the enclosing method declarations.  We mark the decl invalid
817    // to make it clear that this isn't a valid AST.
818    CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
819                                     ClassLoc, CategoryLoc, CategoryName,IDecl);
820    CDecl->setInvalidDecl();
821    CurContext->addDecl(CDecl);
822
823    if (!IDecl)
824      Diag(ClassLoc, diag::err_undef_interface) << ClassName;
825    return ActOnObjCContainerStartDefinition(CDecl);
826  }
827
828  if (!CategoryName && IDecl->getImplementation()) {
829    Diag(ClassLoc, diag::err_class_extension_after_impl) << ClassName;
830    Diag(IDecl->getImplementation()->getLocation(),
831          diag::note_implementation_declared);
832  }
833
834  if (CategoryName) {
835    /// Check for duplicate interface declaration for this category
836    ObjCCategoryDecl *CDeclChain;
837    for (CDeclChain = IDecl->getCategoryList(); CDeclChain;
838         CDeclChain = CDeclChain->getNextClassCategory()) {
839      if (CDeclChain->getIdentifier() == CategoryName) {
840        // Class extensions can be declared multiple times.
841        Diag(CategoryLoc, diag::warn_dup_category_def)
842          << ClassName << CategoryName;
843        Diag(CDeclChain->getLocation(), diag::note_previous_definition);
844        break;
845      }
846    }
847  }
848
849  CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc,
850                                   ClassLoc, CategoryLoc, CategoryName, IDecl);
851  // FIXME: PushOnScopeChains?
852  CurContext->addDecl(CDecl);
853
854  if (NumProtoRefs) {
855    CDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs,
856                           ProtoLocs, Context);
857    // Protocols in the class extension belong to the class.
858    if (CDecl->IsClassExtension())
859     IDecl->mergeClassExtensionProtocolList((ObjCProtocolDecl*const*)ProtoRefs,
860                                            NumProtoRefs, Context);
861  }
862
863  CheckObjCDeclScope(CDecl);
864  return ActOnObjCContainerStartDefinition(CDecl);
865}
866
867/// ActOnStartCategoryImplementation - Perform semantic checks on the
868/// category implementation declaration and build an ObjCCategoryImplDecl
869/// object.
870Decl *Sema::ActOnStartCategoryImplementation(
871                      SourceLocation AtCatImplLoc,
872                      IdentifierInfo *ClassName, SourceLocation ClassLoc,
873                      IdentifierInfo *CatName, SourceLocation CatLoc) {
874  ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
875  ObjCCategoryDecl *CatIDecl = 0;
876  if (IDecl && IDecl->hasDefinition()) {
877    CatIDecl = IDecl->FindCategoryDeclaration(CatName);
878    if (!CatIDecl) {
879      // Category @implementation with no corresponding @interface.
880      // Create and install one.
881      CatIDecl = ObjCCategoryDecl::Create(Context, CurContext, AtCatImplLoc,
882                                          ClassLoc, CatLoc,
883                                          CatName, IDecl);
884      CatIDecl->setImplicit();
885    }
886  }
887
888  ObjCCategoryImplDecl *CDecl =
889    ObjCCategoryImplDecl::Create(Context, CurContext, CatName, IDecl,
890                                 ClassLoc, AtCatImplLoc, CatLoc);
891  /// Check that class of this category is already completely declared.
892  if (!IDecl) {
893    Diag(ClassLoc, diag::err_undef_interface) << ClassName;
894    CDecl->setInvalidDecl();
895  } else if (RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
896                                 diag::err_undef_interface)) {
897    CDecl->setInvalidDecl();
898  }
899
900  // FIXME: PushOnScopeChains?
901  CurContext->addDecl(CDecl);
902
903  // If the interface is deprecated/unavailable, warn/error about it.
904  if (IDecl)
905    DiagnoseUseOfDecl(IDecl, ClassLoc);
906
907  /// Check that CatName, category name, is not used in another implementation.
908  if (CatIDecl) {
909    if (CatIDecl->getImplementation()) {
910      Diag(ClassLoc, diag::err_dup_implementation_category) << ClassName
911        << CatName;
912      Diag(CatIDecl->getImplementation()->getLocation(),
913           diag::note_previous_definition);
914    } else {
915      CatIDecl->setImplementation(CDecl);
916      // Warn on implementating category of deprecated class under
917      // -Wdeprecated-implementations flag.
918      DiagnoseObjCImplementedDeprecations(*this,
919                                          dyn_cast<NamedDecl>(IDecl),
920                                          CDecl->getLocation(), 2);
921    }
922  }
923
924  CheckObjCDeclScope(CDecl);
925  return ActOnObjCContainerStartDefinition(CDecl);
926}
927
928Decl *Sema::ActOnStartClassImplementation(
929                      SourceLocation AtClassImplLoc,
930                      IdentifierInfo *ClassName, SourceLocation ClassLoc,
931                      IdentifierInfo *SuperClassname,
932                      SourceLocation SuperClassLoc) {
933  ObjCInterfaceDecl* IDecl = 0;
934  // Check for another declaration kind with the same name.
935  NamedDecl *PrevDecl
936    = LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName,
937                       ForRedeclaration);
938  if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
939    Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
940    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
941  } else if ((IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl))) {
942    RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl),
943                        diag::warn_undef_interface);
944  } else {
945    // We did not find anything with the name ClassName; try to correct for
946    // typos in the class name.
947    ObjCInterfaceValidatorCCC Validator;
948    if (TypoCorrection Corrected = CorrectTypo(
949        DeclarationNameInfo(ClassName, ClassLoc), LookupOrdinaryName, TUScope,
950        NULL, Validator)) {
951      // Suggest the (potentially) correct interface name. However, put the
952      // fix-it hint itself in a separate note, since changing the name in
953      // the warning would make the fix-it change semantics.However, don't
954      // provide a code-modification hint or use the typo name for recovery,
955      // because this is just a warning. The program may actually be correct.
956      IDecl = Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>();
957      DeclarationName CorrectedName = Corrected.getCorrection();
958      Diag(ClassLoc, diag::warn_undef_interface_suggest)
959        << ClassName << CorrectedName;
960      Diag(IDecl->getLocation(), diag::note_previous_decl) << CorrectedName
961        << FixItHint::CreateReplacement(ClassLoc, CorrectedName.getAsString());
962      IDecl = 0;
963    } else {
964      Diag(ClassLoc, diag::warn_undef_interface) << ClassName;
965    }
966  }
967
968  // Check that super class name is valid class name
969  ObjCInterfaceDecl* SDecl = 0;
970  if (SuperClassname) {
971    // Check if a different kind of symbol declared in this scope.
972    PrevDecl = LookupSingleName(TUScope, SuperClassname, SuperClassLoc,
973                                LookupOrdinaryName);
974    if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
975      Diag(SuperClassLoc, diag::err_redefinition_different_kind)
976        << SuperClassname;
977      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
978    } else {
979      SDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
980      if (SDecl && !SDecl->hasDefinition())
981        SDecl = 0;
982      if (!SDecl)
983        Diag(SuperClassLoc, diag::err_undef_superclass)
984          << SuperClassname << ClassName;
985      else if (IDecl && !declaresSameEntity(IDecl->getSuperClass(), SDecl)) {
986        // This implementation and its interface do not have the same
987        // super class.
988        Diag(SuperClassLoc, diag::err_conflicting_super_class)
989          << SDecl->getDeclName();
990        Diag(SDecl->getLocation(), diag::note_previous_definition);
991      }
992    }
993  }
994
995  if (!IDecl) {
996    // Legacy case of @implementation with no corresponding @interface.
997    // Build, chain & install the interface decl into the identifier.
998
999    // FIXME: Do we support attributes on the @implementation? If so we should
1000    // copy them over.
1001    IDecl = ObjCInterfaceDecl::Create(Context, CurContext, AtClassImplLoc,
1002                                      ClassName, /*PrevDecl=*/0, ClassLoc,
1003                                      true);
1004    IDecl->startDefinition();
1005    if (SDecl) {
1006      IDecl->setSuperClass(SDecl);
1007      IDecl->setSuperClassLoc(SuperClassLoc);
1008      IDecl->setEndOfDefinitionLoc(SuperClassLoc);
1009    } else {
1010      IDecl->setEndOfDefinitionLoc(ClassLoc);
1011    }
1012
1013    PushOnScopeChains(IDecl, TUScope);
1014  } else {
1015    // Mark the interface as being completed, even if it was just as
1016    //   @class ....;
1017    // declaration; the user cannot reopen it.
1018    if (!IDecl->hasDefinition())
1019      IDecl->startDefinition();
1020  }
1021
1022  ObjCImplementationDecl* IMPDecl =
1023    ObjCImplementationDecl::Create(Context, CurContext, IDecl, SDecl,
1024                                   ClassLoc, AtClassImplLoc);
1025
1026  if (CheckObjCDeclScope(IMPDecl))
1027    return ActOnObjCContainerStartDefinition(IMPDecl);
1028
1029  // Check that there is no duplicate implementation of this class.
1030  if (IDecl->getImplementation()) {
1031    // FIXME: Don't leak everything!
1032    Diag(ClassLoc, diag::err_dup_implementation_class) << ClassName;
1033    Diag(IDecl->getImplementation()->getLocation(),
1034         diag::note_previous_definition);
1035  } else { // add it to the list.
1036    IDecl->setImplementation(IMPDecl);
1037    PushOnScopeChains(IMPDecl, TUScope);
1038    // Warn on implementating deprecated class under
1039    // -Wdeprecated-implementations flag.
1040    DiagnoseObjCImplementedDeprecations(*this,
1041                                        dyn_cast<NamedDecl>(IDecl),
1042                                        IMPDecl->getLocation(), 1);
1043  }
1044  return ActOnObjCContainerStartDefinition(IMPDecl);
1045}
1046
1047Sema::DeclGroupPtrTy
1048Sema::ActOnFinishObjCImplementation(Decl *ObjCImpDecl, ArrayRef<Decl *> Decls) {
1049  SmallVector<Decl *, 64> DeclsInGroup;
1050  DeclsInGroup.reserve(Decls.size() + 1);
1051
1052  for (unsigned i = 0, e = Decls.size(); i != e; ++i) {
1053    Decl *Dcl = Decls[i];
1054    if (!Dcl)
1055      continue;
1056    if (Dcl->getDeclContext()->isFileContext())
1057      Dcl->setTopLevelDeclInObjCContainer();
1058    DeclsInGroup.push_back(Dcl);
1059  }
1060
1061  DeclsInGroup.push_back(ObjCImpDecl);
1062
1063  return BuildDeclaratorGroup(DeclsInGroup.data(), DeclsInGroup.size(), false);
1064}
1065
1066void Sema::CheckImplementationIvars(ObjCImplementationDecl *ImpDecl,
1067                                    ObjCIvarDecl **ivars, unsigned numIvars,
1068                                    SourceLocation RBrace) {
1069  assert(ImpDecl && "missing implementation decl");
1070  ObjCInterfaceDecl* IDecl = ImpDecl->getClassInterface();
1071  if (!IDecl)
1072    return;
1073  /// Check case of non-existing \@interface decl.
1074  /// (legacy objective-c \@implementation decl without an \@interface decl).
1075  /// Add implementations's ivar to the synthesize class's ivar list.
1076  if (IDecl->isImplicitInterfaceDecl()) {
1077    IDecl->setEndOfDefinitionLoc(RBrace);
1078    // Add ivar's to class's DeclContext.
1079    for (unsigned i = 0, e = numIvars; i != e; ++i) {
1080      ivars[i]->setLexicalDeclContext(ImpDecl);
1081      IDecl->makeDeclVisibleInContext(ivars[i]);
1082      ImpDecl->addDecl(ivars[i]);
1083    }
1084
1085    return;
1086  }
1087  // If implementation has empty ivar list, just return.
1088  if (numIvars == 0)
1089    return;
1090
1091  assert(ivars && "missing @implementation ivars");
1092  if (LangOpts.ObjCRuntime.isNonFragile()) {
1093    if (ImpDecl->getSuperClass())
1094      Diag(ImpDecl->getLocation(), diag::warn_on_superclass_use);
1095    for (unsigned i = 0; i < numIvars; i++) {
1096      ObjCIvarDecl* ImplIvar = ivars[i];
1097      if (const ObjCIvarDecl *ClsIvar =
1098            IDecl->getIvarDecl(ImplIvar->getIdentifier())) {
1099        Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration);
1100        Diag(ClsIvar->getLocation(), diag::note_previous_definition);
1101        continue;
1102      }
1103      // Instance ivar to Implementation's DeclContext.
1104      ImplIvar->setLexicalDeclContext(ImpDecl);
1105      IDecl->makeDeclVisibleInContext(ImplIvar);
1106      ImpDecl->addDecl(ImplIvar);
1107    }
1108    return;
1109  }
1110  // Check interface's Ivar list against those in the implementation.
1111  // names and types must match.
1112  //
1113  unsigned j = 0;
1114  ObjCInterfaceDecl::ivar_iterator
1115    IVI = IDecl->ivar_begin(), IVE = IDecl->ivar_end();
1116  for (; numIvars > 0 && IVI != IVE; ++IVI) {
1117    ObjCIvarDecl* ImplIvar = ivars[j++];
1118    ObjCIvarDecl* ClsIvar = *IVI;
1119    assert (ImplIvar && "missing implementation ivar");
1120    assert (ClsIvar && "missing class ivar");
1121
1122    // First, make sure the types match.
1123    if (!Context.hasSameType(ImplIvar->getType(), ClsIvar->getType())) {
1124      Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_type)
1125        << ImplIvar->getIdentifier()
1126        << ImplIvar->getType() << ClsIvar->getType();
1127      Diag(ClsIvar->getLocation(), diag::note_previous_definition);
1128    } else if (ImplIvar->isBitField() && ClsIvar->isBitField() &&
1129               ImplIvar->getBitWidthValue(Context) !=
1130               ClsIvar->getBitWidthValue(Context)) {
1131      Diag(ImplIvar->getBitWidth()->getLocStart(),
1132           diag::err_conflicting_ivar_bitwidth) << ImplIvar->getIdentifier();
1133      Diag(ClsIvar->getBitWidth()->getLocStart(),
1134           diag::note_previous_definition);
1135    }
1136    // Make sure the names are identical.
1137    if (ImplIvar->getIdentifier() != ClsIvar->getIdentifier()) {
1138      Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_name)
1139        << ImplIvar->getIdentifier() << ClsIvar->getIdentifier();
1140      Diag(ClsIvar->getLocation(), diag::note_previous_definition);
1141    }
1142    --numIvars;
1143  }
1144
1145  if (numIvars > 0)
1146    Diag(ivars[j]->getLocation(), diag::err_inconsistant_ivar_count);
1147  else if (IVI != IVE)
1148    Diag(IVI->getLocation(), diag::err_inconsistant_ivar_count);
1149}
1150
1151void Sema::WarnUndefinedMethod(SourceLocation ImpLoc, ObjCMethodDecl *method,
1152                               bool &IncompleteImpl, unsigned DiagID) {
1153  // No point warning no definition of method which is 'unavailable'.
1154  if (method->hasAttr<UnavailableAttr>())
1155    return;
1156  if (!IncompleteImpl) {
1157    Diag(ImpLoc, diag::warn_incomplete_impl);
1158    IncompleteImpl = true;
1159  }
1160  if (DiagID == diag::warn_unimplemented_protocol_method)
1161    Diag(ImpLoc, DiagID) << method->getDeclName();
1162  else
1163    Diag(method->getLocation(), DiagID) << method->getDeclName();
1164}
1165
1166/// Determines if type B can be substituted for type A.  Returns true if we can
1167/// guarantee that anything that the user will do to an object of type A can
1168/// also be done to an object of type B.  This is trivially true if the two
1169/// types are the same, or if B is a subclass of A.  It becomes more complex
1170/// in cases where protocols are involved.
1171///
1172/// Object types in Objective-C describe the minimum requirements for an
1173/// object, rather than providing a complete description of a type.  For
1174/// example, if A is a subclass of B, then B* may refer to an instance of A.
1175/// The principle of substitutability means that we may use an instance of A
1176/// anywhere that we may use an instance of B - it will implement all of the
1177/// ivars of B and all of the methods of B.
1178///
1179/// This substitutability is important when type checking methods, because
1180/// the implementation may have stricter type definitions than the interface.
1181/// The interface specifies minimum requirements, but the implementation may
1182/// have more accurate ones.  For example, a method may privately accept
1183/// instances of B, but only publish that it accepts instances of A.  Any
1184/// object passed to it will be type checked against B, and so will implicitly
1185/// by a valid A*.  Similarly, a method may return a subclass of the class that
1186/// it is declared as returning.
1187///
1188/// This is most important when considering subclassing.  A method in a
1189/// subclass must accept any object as an argument that its superclass's
1190/// implementation accepts.  It may, however, accept a more general type
1191/// without breaking substitutability (i.e. you can still use the subclass
1192/// anywhere that you can use the superclass, but not vice versa).  The
1193/// converse requirement applies to return types: the return type for a
1194/// subclass method must be a valid object of the kind that the superclass
1195/// advertises, but it may be specified more accurately.  This avoids the need
1196/// for explicit down-casting by callers.
1197///
1198/// Note: This is a stricter requirement than for assignment.
1199static bool isObjCTypeSubstitutable(ASTContext &Context,
1200                                    const ObjCObjectPointerType *A,
1201                                    const ObjCObjectPointerType *B,
1202                                    bool rejectId) {
1203  // Reject a protocol-unqualified id.
1204  if (rejectId && B->isObjCIdType()) return false;
1205
1206  // If B is a qualified id, then A must also be a qualified id and it must
1207  // implement all of the protocols in B.  It may not be a qualified class.
1208  // For example, MyClass<A> can be assigned to id<A>, but MyClass<A> is a
1209  // stricter definition so it is not substitutable for id<A>.
1210  if (B->isObjCQualifiedIdType()) {
1211    return A->isObjCQualifiedIdType() &&
1212           Context.ObjCQualifiedIdTypesAreCompatible(QualType(A, 0),
1213                                                     QualType(B,0),
1214                                                     false);
1215  }
1216
1217  /*
1218  // id is a special type that bypasses type checking completely.  We want a
1219  // warning when it is used in one place but not another.
1220  if (C.isObjCIdType(A) || C.isObjCIdType(B)) return false;
1221
1222
1223  // If B is a qualified id, then A must also be a qualified id (which it isn't
1224  // if we've got this far)
1225  if (B->isObjCQualifiedIdType()) return false;
1226  */
1227
1228  // Now we know that A and B are (potentially-qualified) class types.  The
1229  // normal rules for assignment apply.
1230  return Context.canAssignObjCInterfaces(A, B);
1231}
1232
1233static SourceRange getTypeRange(TypeSourceInfo *TSI) {
1234  return (TSI ? TSI->getTypeLoc().getSourceRange() : SourceRange());
1235}
1236
1237static bool CheckMethodOverrideReturn(Sema &S,
1238                                      ObjCMethodDecl *MethodImpl,
1239                                      ObjCMethodDecl *MethodDecl,
1240                                      bool IsProtocolMethodDecl,
1241                                      bool IsOverridingMode,
1242                                      bool Warn) {
1243  if (IsProtocolMethodDecl &&
1244      (MethodDecl->getObjCDeclQualifier() !=
1245       MethodImpl->getObjCDeclQualifier())) {
1246    if (Warn) {
1247        S.Diag(MethodImpl->getLocation(),
1248               (IsOverridingMode ?
1249                 diag::warn_conflicting_overriding_ret_type_modifiers
1250                 : diag::warn_conflicting_ret_type_modifiers))
1251          << MethodImpl->getDeclName()
1252          << getTypeRange(MethodImpl->getResultTypeSourceInfo());
1253        S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration)
1254          << getTypeRange(MethodDecl->getResultTypeSourceInfo());
1255    }
1256    else
1257      return false;
1258  }
1259
1260  if (S.Context.hasSameUnqualifiedType(MethodImpl->getResultType(),
1261                                       MethodDecl->getResultType()))
1262    return true;
1263  if (!Warn)
1264    return false;
1265
1266  unsigned DiagID =
1267    IsOverridingMode ? diag::warn_conflicting_overriding_ret_types
1268                     : diag::warn_conflicting_ret_types;
1269
1270  // Mismatches between ObjC pointers go into a different warning
1271  // category, and sometimes they're even completely whitelisted.
1272  if (const ObjCObjectPointerType *ImplPtrTy =
1273        MethodImpl->getResultType()->getAs<ObjCObjectPointerType>()) {
1274    if (const ObjCObjectPointerType *IfacePtrTy =
1275          MethodDecl->getResultType()->getAs<ObjCObjectPointerType>()) {
1276      // Allow non-matching return types as long as they don't violate
1277      // the principle of substitutability.  Specifically, we permit
1278      // return types that are subclasses of the declared return type,
1279      // or that are more-qualified versions of the declared type.
1280      if (isObjCTypeSubstitutable(S.Context, IfacePtrTy, ImplPtrTy, false))
1281        return false;
1282
1283      DiagID =
1284        IsOverridingMode ? diag::warn_non_covariant_overriding_ret_types
1285                          : diag::warn_non_covariant_ret_types;
1286    }
1287  }
1288
1289  S.Diag(MethodImpl->getLocation(), DiagID)
1290    << MethodImpl->getDeclName()
1291    << MethodDecl->getResultType()
1292    << MethodImpl->getResultType()
1293    << getTypeRange(MethodImpl->getResultTypeSourceInfo());
1294  S.Diag(MethodDecl->getLocation(),
1295         IsOverridingMode ? diag::note_previous_declaration
1296                          : diag::note_previous_definition)
1297    << getTypeRange(MethodDecl->getResultTypeSourceInfo());
1298  return false;
1299}
1300
1301static bool CheckMethodOverrideParam(Sema &S,
1302                                     ObjCMethodDecl *MethodImpl,
1303                                     ObjCMethodDecl *MethodDecl,
1304                                     ParmVarDecl *ImplVar,
1305                                     ParmVarDecl *IfaceVar,
1306                                     bool IsProtocolMethodDecl,
1307                                     bool IsOverridingMode,
1308                                     bool Warn) {
1309  if (IsProtocolMethodDecl &&
1310      (ImplVar->getObjCDeclQualifier() !=
1311       IfaceVar->getObjCDeclQualifier())) {
1312    if (Warn) {
1313      if (IsOverridingMode)
1314        S.Diag(ImplVar->getLocation(),
1315               diag::warn_conflicting_overriding_param_modifiers)
1316            << getTypeRange(ImplVar->getTypeSourceInfo())
1317            << MethodImpl->getDeclName();
1318      else S.Diag(ImplVar->getLocation(),
1319             diag::warn_conflicting_param_modifiers)
1320          << getTypeRange(ImplVar->getTypeSourceInfo())
1321          << MethodImpl->getDeclName();
1322      S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration)
1323          << getTypeRange(IfaceVar->getTypeSourceInfo());
1324    }
1325    else
1326      return false;
1327  }
1328
1329  QualType ImplTy = ImplVar->getType();
1330  QualType IfaceTy = IfaceVar->getType();
1331
1332  if (S.Context.hasSameUnqualifiedType(ImplTy, IfaceTy))
1333    return true;
1334
1335  if (!Warn)
1336    return false;
1337  unsigned DiagID =
1338    IsOverridingMode ? diag::warn_conflicting_overriding_param_types
1339                     : diag::warn_conflicting_param_types;
1340
1341  // Mismatches between ObjC pointers go into a different warning
1342  // category, and sometimes they're even completely whitelisted.
1343  if (const ObjCObjectPointerType *ImplPtrTy =
1344        ImplTy->getAs<ObjCObjectPointerType>()) {
1345    if (const ObjCObjectPointerType *IfacePtrTy =
1346          IfaceTy->getAs<ObjCObjectPointerType>()) {
1347      // Allow non-matching argument types as long as they don't
1348      // violate the principle of substitutability.  Specifically, the
1349      // implementation must accept any objects that the superclass
1350      // accepts, however it may also accept others.
1351      if (isObjCTypeSubstitutable(S.Context, ImplPtrTy, IfacePtrTy, true))
1352        return false;
1353
1354      DiagID =
1355      IsOverridingMode ? diag::warn_non_contravariant_overriding_param_types
1356                       :  diag::warn_non_contravariant_param_types;
1357    }
1358  }
1359
1360  S.Diag(ImplVar->getLocation(), DiagID)
1361    << getTypeRange(ImplVar->getTypeSourceInfo())
1362    << MethodImpl->getDeclName() << IfaceTy << ImplTy;
1363  S.Diag(IfaceVar->getLocation(),
1364         (IsOverridingMode ? diag::note_previous_declaration
1365                        : diag::note_previous_definition))
1366    << getTypeRange(IfaceVar->getTypeSourceInfo());
1367  return false;
1368}
1369
1370/// In ARC, check whether the conventional meanings of the two methods
1371/// match.  If they don't, it's a hard error.
1372static bool checkMethodFamilyMismatch(Sema &S, ObjCMethodDecl *impl,
1373                                      ObjCMethodDecl *decl) {
1374  ObjCMethodFamily implFamily = impl->getMethodFamily();
1375  ObjCMethodFamily declFamily = decl->getMethodFamily();
1376  if (implFamily == declFamily) return false;
1377
1378  // Since conventions are sorted by selector, the only possibility is
1379  // that the types differ enough to cause one selector or the other
1380  // to fall out of the family.
1381  assert(implFamily == OMF_None || declFamily == OMF_None);
1382
1383  // No further diagnostics required on invalid declarations.
1384  if (impl->isInvalidDecl() || decl->isInvalidDecl()) return true;
1385
1386  const ObjCMethodDecl *unmatched = impl;
1387  ObjCMethodFamily family = declFamily;
1388  unsigned errorID = diag::err_arc_lost_method_convention;
1389  unsigned noteID = diag::note_arc_lost_method_convention;
1390  if (declFamily == OMF_None) {
1391    unmatched = decl;
1392    family = implFamily;
1393    errorID = diag::err_arc_gained_method_convention;
1394    noteID = diag::note_arc_gained_method_convention;
1395  }
1396
1397  // Indexes into a %select clause in the diagnostic.
1398  enum FamilySelector {
1399    F_alloc, F_copy, F_mutableCopy = F_copy, F_init, F_new
1400  };
1401  FamilySelector familySelector = FamilySelector();
1402
1403  switch (family) {
1404  case OMF_None: llvm_unreachable("logic error, no method convention");
1405  case OMF_retain:
1406  case OMF_release:
1407  case OMF_autorelease:
1408  case OMF_dealloc:
1409  case OMF_finalize:
1410  case OMF_retainCount:
1411  case OMF_self:
1412  case OMF_performSelector:
1413    // Mismatches for these methods don't change ownership
1414    // conventions, so we don't care.
1415    return false;
1416
1417  case OMF_init: familySelector = F_init; break;
1418  case OMF_alloc: familySelector = F_alloc; break;
1419  case OMF_copy: familySelector = F_copy; break;
1420  case OMF_mutableCopy: familySelector = F_mutableCopy; break;
1421  case OMF_new: familySelector = F_new; break;
1422  }
1423
1424  enum ReasonSelector { R_NonObjectReturn, R_UnrelatedReturn };
1425  ReasonSelector reasonSelector;
1426
1427  // The only reason these methods don't fall within their families is
1428  // due to unusual result types.
1429  if (unmatched->getResultType()->isObjCObjectPointerType()) {
1430    reasonSelector = R_UnrelatedReturn;
1431  } else {
1432    reasonSelector = R_NonObjectReturn;
1433  }
1434
1435  S.Diag(impl->getLocation(), errorID) << familySelector << reasonSelector;
1436  S.Diag(decl->getLocation(), noteID) << familySelector << reasonSelector;
1437
1438  return true;
1439}
1440
1441void Sema::WarnConflictingTypedMethods(ObjCMethodDecl *ImpMethodDecl,
1442                                       ObjCMethodDecl *MethodDecl,
1443                                       bool IsProtocolMethodDecl) {
1444  if (getLangOpts().ObjCAutoRefCount &&
1445      checkMethodFamilyMismatch(*this, ImpMethodDecl, MethodDecl))
1446    return;
1447
1448  CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
1449                            IsProtocolMethodDecl, false,
1450                            true);
1451
1452  for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
1453       IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
1454       EF = MethodDecl->param_end();
1455       IM != EM && IF != EF; ++IM, ++IF) {
1456    CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, *IM, *IF,
1457                             IsProtocolMethodDecl, false, true);
1458  }
1459
1460  if (ImpMethodDecl->isVariadic() != MethodDecl->isVariadic()) {
1461    Diag(ImpMethodDecl->getLocation(),
1462         diag::warn_conflicting_variadic);
1463    Diag(MethodDecl->getLocation(), diag::note_previous_declaration);
1464  }
1465}
1466
1467void Sema::CheckConflictingOverridingMethod(ObjCMethodDecl *Method,
1468                                       ObjCMethodDecl *Overridden,
1469                                       bool IsProtocolMethodDecl) {
1470
1471  CheckMethodOverrideReturn(*this, Method, Overridden,
1472                            IsProtocolMethodDecl, true,
1473                            true);
1474
1475  for (ObjCMethodDecl::param_iterator IM = Method->param_begin(),
1476       IF = Overridden->param_begin(), EM = Method->param_end(),
1477       EF = Overridden->param_end();
1478       IM != EM && IF != EF; ++IM, ++IF) {
1479    CheckMethodOverrideParam(*this, Method, Overridden, *IM, *IF,
1480                             IsProtocolMethodDecl, true, true);
1481  }
1482
1483  if (Method->isVariadic() != Overridden->isVariadic()) {
1484    Diag(Method->getLocation(),
1485         diag::warn_conflicting_overriding_variadic);
1486    Diag(Overridden->getLocation(), diag::note_previous_declaration);
1487  }
1488}
1489
1490/// WarnExactTypedMethods - This routine issues a warning if method
1491/// implementation declaration matches exactly that of its declaration.
1492void Sema::WarnExactTypedMethods(ObjCMethodDecl *ImpMethodDecl,
1493                                 ObjCMethodDecl *MethodDecl,
1494                                 bool IsProtocolMethodDecl) {
1495  // don't issue warning when protocol method is optional because primary
1496  // class is not required to implement it and it is safe for protocol
1497  // to implement it.
1498  if (MethodDecl->getImplementationControl() == ObjCMethodDecl::Optional)
1499    return;
1500  // don't issue warning when primary class's method is
1501  // depecated/unavailable.
1502  if (MethodDecl->hasAttr<UnavailableAttr>() ||
1503      MethodDecl->hasAttr<DeprecatedAttr>())
1504    return;
1505
1506  bool match = CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl,
1507                                      IsProtocolMethodDecl, false, false);
1508  if (match)
1509    for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(),
1510         IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(),
1511         EF = MethodDecl->param_end();
1512         IM != EM && IF != EF; ++IM, ++IF) {
1513      match = CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl,
1514                                       *IM, *IF,
1515                                       IsProtocolMethodDecl, false, false);
1516      if (!match)
1517        break;
1518    }
1519  if (match)
1520    match = (ImpMethodDecl->isVariadic() == MethodDecl->isVariadic());
1521  if (match)
1522    match = !(MethodDecl->isClassMethod() &&
1523              MethodDecl->getSelector() == GetNullarySelector("load", Context));
1524
1525  if (match) {
1526    Diag(ImpMethodDecl->getLocation(),
1527         diag::warn_category_method_impl_match);
1528    Diag(MethodDecl->getLocation(), diag::note_method_declared_at)
1529      << MethodDecl->getDeclName();
1530  }
1531}
1532
1533/// FIXME: Type hierarchies in Objective-C can be deep. We could most likely
1534/// improve the efficiency of selector lookups and type checking by associating
1535/// with each protocol / interface / category the flattened instance tables. If
1536/// we used an immutable set to keep the table then it wouldn't add significant
1537/// memory cost and it would be handy for lookups.
1538
1539/// CheckProtocolMethodDefs - This routine checks unimplemented methods
1540/// Declared in protocol, and those referenced by it.
1541void Sema::CheckProtocolMethodDefs(SourceLocation ImpLoc,
1542                                   ObjCProtocolDecl *PDecl,
1543                                   bool& IncompleteImpl,
1544                                   const SelectorSet &InsMap,
1545                                   const SelectorSet &ClsMap,
1546                                   ObjCContainerDecl *CDecl) {
1547  ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl);
1548  ObjCInterfaceDecl *IDecl = C ? C->getClassInterface()
1549                               : dyn_cast<ObjCInterfaceDecl>(CDecl);
1550  assert (IDecl && "CheckProtocolMethodDefs - IDecl is null");
1551
1552  ObjCInterfaceDecl *Super = IDecl->getSuperClass();
1553  ObjCInterfaceDecl *NSIDecl = 0;
1554  if (getLangOpts().ObjCRuntime.isNeXTFamily()) {
1555    // check to see if class implements forwardInvocation method and objects
1556    // of this class are derived from 'NSProxy' so that to forward requests
1557    // from one object to another.
1558    // Under such conditions, which means that every method possible is
1559    // implemented in the class, we should not issue "Method definition not
1560    // found" warnings.
1561    // FIXME: Use a general GetUnarySelector method for this.
1562    IdentifierInfo* II = &Context.Idents.get("forwardInvocation");
1563    Selector fISelector = Context.Selectors.getSelector(1, &II);
1564    if (InsMap.count(fISelector))
1565      // Is IDecl derived from 'NSProxy'? If so, no instance methods
1566      // need be implemented in the implementation.
1567      NSIDecl = IDecl->lookupInheritedClass(&Context.Idents.get("NSProxy"));
1568  }
1569
1570  // If a method lookup fails locally we still need to look and see if
1571  // the method was implemented by a base class or an inherited
1572  // protocol. This lookup is slow, but occurs rarely in correct code
1573  // and otherwise would terminate in a warning.
1574
1575  // check unimplemented instance methods.
1576  if (!NSIDecl)
1577    for (ObjCProtocolDecl::instmeth_iterator I = PDecl->instmeth_begin(),
1578         E = PDecl->instmeth_end(); I != E; ++I) {
1579      ObjCMethodDecl *method = *I;
1580      if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
1581          !method->isPropertyAccessor() &&
1582          !InsMap.count(method->getSelector()) &&
1583          (!Super || !Super->lookupInstanceMethod(method->getSelector()))) {
1584            // If a method is not implemented in the category implementation but
1585            // has been declared in its primary class, superclass,
1586            // or in one of their protocols, no need to issue the warning.
1587            // This is because method will be implemented in the primary class
1588            // or one of its super class implementation.
1589
1590            // Ugly, but necessary. Method declared in protcol might have
1591            // have been synthesized due to a property declared in the class which
1592            // uses the protocol.
1593            if (ObjCMethodDecl *MethodInClass =
1594                  IDecl->lookupInstanceMethod(method->getSelector(),
1595                                              true /*shallowCategoryLookup*/))
1596              if (C || MethodInClass->isPropertyAccessor())
1597                continue;
1598            unsigned DIAG = diag::warn_unimplemented_protocol_method;
1599            if (Diags.getDiagnosticLevel(DIAG, ImpLoc)
1600                != DiagnosticsEngine::Ignored) {
1601              WarnUndefinedMethod(ImpLoc, method, IncompleteImpl, DIAG);
1602              Diag(method->getLocation(), diag::note_method_declared_at)
1603                << method->getDeclName();
1604              Diag(CDecl->getLocation(), diag::note_required_for_protocol_at)
1605                << PDecl->getDeclName();
1606            }
1607          }
1608    }
1609  // check unimplemented class methods
1610  for (ObjCProtocolDecl::classmeth_iterator
1611         I = PDecl->classmeth_begin(), E = PDecl->classmeth_end();
1612       I != E; ++I) {
1613    ObjCMethodDecl *method = *I;
1614    if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
1615        !ClsMap.count(method->getSelector()) &&
1616        (!Super || !Super->lookupClassMethod(method->getSelector()))) {
1617      // See above comment for instance method lookups.
1618      if (C && IDecl->lookupClassMethod(method->getSelector(),
1619                                        true /*shallowCategoryLookup*/))
1620        continue;
1621      unsigned DIAG = diag::warn_unimplemented_protocol_method;
1622      if (Diags.getDiagnosticLevel(DIAG, ImpLoc) !=
1623            DiagnosticsEngine::Ignored) {
1624        WarnUndefinedMethod(ImpLoc, method, IncompleteImpl, DIAG);
1625        Diag(method->getLocation(), diag::note_method_declared_at)
1626          << method->getDeclName();
1627        Diag(IDecl->getLocation(), diag::note_required_for_protocol_at) <<
1628          PDecl->getDeclName();
1629      }
1630    }
1631  }
1632  // Check on this protocols's referenced protocols, recursively.
1633  for (ObjCProtocolDecl::protocol_iterator PI = PDecl->protocol_begin(),
1634       E = PDecl->protocol_end(); PI != E; ++PI)
1635    CheckProtocolMethodDefs(ImpLoc, *PI, IncompleteImpl, InsMap, ClsMap, CDecl);
1636}
1637
1638/// MatchAllMethodDeclarations - Check methods declared in interface
1639/// or protocol against those declared in their implementations.
1640///
1641void Sema::MatchAllMethodDeclarations(const SelectorSet &InsMap,
1642                                      const SelectorSet &ClsMap,
1643                                      SelectorSet &InsMapSeen,
1644                                      SelectorSet &ClsMapSeen,
1645                                      ObjCImplDecl* IMPDecl,
1646                                      ObjCContainerDecl* CDecl,
1647                                      bool &IncompleteImpl,
1648                                      bool ImmediateClass,
1649                                      bool WarnCategoryMethodImpl) {
1650  // Check and see if instance methods in class interface have been
1651  // implemented in the implementation class. If so, their types match.
1652  for (ObjCInterfaceDecl::instmeth_iterator I = CDecl->instmeth_begin(),
1653       E = CDecl->instmeth_end(); I != E; ++I) {
1654    if (InsMapSeen.count((*I)->getSelector()))
1655        continue;
1656    InsMapSeen.insert((*I)->getSelector());
1657    if (!(*I)->isPropertyAccessor() &&
1658        !InsMap.count((*I)->getSelector())) {
1659      if (ImmediateClass)
1660        WarnUndefinedMethod(IMPDecl->getLocation(), *I, IncompleteImpl,
1661                            diag::note_undef_method_impl);
1662      continue;
1663    } else {
1664      ObjCMethodDecl *ImpMethodDecl =
1665        IMPDecl->getInstanceMethod((*I)->getSelector());
1666      assert(CDecl->getInstanceMethod((*I)->getSelector()) &&
1667             "Expected to find the method through lookup as well");
1668      ObjCMethodDecl *MethodDecl = *I;
1669      // ImpMethodDecl may be null as in a @dynamic property.
1670      if (ImpMethodDecl) {
1671        if (!WarnCategoryMethodImpl)
1672          WarnConflictingTypedMethods(ImpMethodDecl, MethodDecl,
1673                                      isa<ObjCProtocolDecl>(CDecl));
1674        else if (!MethodDecl->isPropertyAccessor())
1675          WarnExactTypedMethods(ImpMethodDecl, MethodDecl,
1676                                isa<ObjCProtocolDecl>(CDecl));
1677      }
1678    }
1679  }
1680
1681  // Check and see if class methods in class interface have been
1682  // implemented in the implementation class. If so, their types match.
1683   for (ObjCInterfaceDecl::classmeth_iterator
1684       I = CDecl->classmeth_begin(), E = CDecl->classmeth_end(); I != E; ++I) {
1685     if (ClsMapSeen.count((*I)->getSelector()))
1686       continue;
1687     ClsMapSeen.insert((*I)->getSelector());
1688    if (!ClsMap.count((*I)->getSelector())) {
1689      if (ImmediateClass)
1690        WarnUndefinedMethod(IMPDecl->getLocation(), *I, IncompleteImpl,
1691                            diag::note_undef_method_impl);
1692    } else {
1693      ObjCMethodDecl *ImpMethodDecl =
1694        IMPDecl->getClassMethod((*I)->getSelector());
1695      assert(CDecl->getClassMethod((*I)->getSelector()) &&
1696             "Expected to find the method through lookup as well");
1697      ObjCMethodDecl *MethodDecl = *I;
1698      if (!WarnCategoryMethodImpl)
1699        WarnConflictingTypedMethods(ImpMethodDecl, MethodDecl,
1700                                    isa<ObjCProtocolDecl>(CDecl));
1701      else
1702        WarnExactTypedMethods(ImpMethodDecl, MethodDecl,
1703                              isa<ObjCProtocolDecl>(CDecl));
1704    }
1705  }
1706
1707  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
1708    // Also methods in class extensions need be looked at next.
1709    for (const ObjCCategoryDecl *ClsExtDecl = I->getFirstClassExtension();
1710         ClsExtDecl; ClsExtDecl = ClsExtDecl->getNextClassExtension())
1711      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
1712                                 IMPDecl,
1713                                 const_cast<ObjCCategoryDecl *>(ClsExtDecl),
1714                                 IncompleteImpl, false,
1715                                 WarnCategoryMethodImpl);
1716
1717    // Check for any implementation of a methods declared in protocol.
1718    for (ObjCInterfaceDecl::all_protocol_iterator
1719          PI = I->all_referenced_protocol_begin(),
1720          E = I->all_referenced_protocol_end(); PI != E; ++PI)
1721      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
1722                                 IMPDecl,
1723                                 (*PI), IncompleteImpl, false,
1724                                 WarnCategoryMethodImpl);
1725
1726    // FIXME. For now, we are not checking for extact match of methods
1727    // in category implementation and its primary class's super class.
1728    if (!WarnCategoryMethodImpl && I->getSuperClass())
1729      MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
1730                                 IMPDecl,
1731                                 I->getSuperClass(), IncompleteImpl, false);
1732  }
1733}
1734
1735/// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
1736/// category matches with those implemented in its primary class and
1737/// warns each time an exact match is found.
1738void Sema::CheckCategoryVsClassMethodMatches(
1739                                  ObjCCategoryImplDecl *CatIMPDecl) {
1740  SelectorSet InsMap, ClsMap;
1741
1742  for (ObjCImplementationDecl::instmeth_iterator
1743       I = CatIMPDecl->instmeth_begin(),
1744       E = CatIMPDecl->instmeth_end(); I!=E; ++I)
1745    InsMap.insert((*I)->getSelector());
1746
1747  for (ObjCImplementationDecl::classmeth_iterator
1748       I = CatIMPDecl->classmeth_begin(),
1749       E = CatIMPDecl->classmeth_end(); I != E; ++I)
1750    ClsMap.insert((*I)->getSelector());
1751  if (InsMap.empty() && ClsMap.empty())
1752    return;
1753
1754  // Get category's primary class.
1755  ObjCCategoryDecl *CatDecl = CatIMPDecl->getCategoryDecl();
1756  if (!CatDecl)
1757    return;
1758  ObjCInterfaceDecl *IDecl = CatDecl->getClassInterface();
1759  if (!IDecl)
1760    return;
1761  SelectorSet InsMapSeen, ClsMapSeen;
1762  bool IncompleteImpl = false;
1763  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
1764                             CatIMPDecl, IDecl,
1765                             IncompleteImpl, false,
1766                             true /*WarnCategoryMethodImpl*/);
1767}
1768
1769void Sema::ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl,
1770                                     ObjCContainerDecl* CDecl,
1771                                     bool IncompleteImpl) {
1772  SelectorSet InsMap;
1773  // Check and see if instance methods in class interface have been
1774  // implemented in the implementation class.
1775  for (ObjCImplementationDecl::instmeth_iterator
1776         I = IMPDecl->instmeth_begin(), E = IMPDecl->instmeth_end(); I!=E; ++I)
1777    InsMap.insert((*I)->getSelector());
1778
1779  // Check and see if properties declared in the interface have either 1)
1780  // an implementation or 2) there is a @synthesize/@dynamic implementation
1781  // of the property in the @implementation.
1782  if (const ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl))
1783    if  (!(LangOpts.ObjCDefaultSynthProperties &&
1784           LangOpts.ObjCRuntime.isNonFragile()) ||
1785         IDecl->isObjCRequiresPropertyDefs())
1786      DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, InsMap);
1787
1788  SelectorSet ClsMap;
1789  for (ObjCImplementationDecl::classmeth_iterator
1790       I = IMPDecl->classmeth_begin(),
1791       E = IMPDecl->classmeth_end(); I != E; ++I)
1792    ClsMap.insert((*I)->getSelector());
1793
1794  // Check for type conflict of methods declared in a class/protocol and
1795  // its implementation; if any.
1796  SelectorSet InsMapSeen, ClsMapSeen;
1797  MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen,
1798                             IMPDecl, CDecl,
1799                             IncompleteImpl, true);
1800
1801  // check all methods implemented in category against those declared
1802  // in its primary class.
1803  if (ObjCCategoryImplDecl *CatDecl =
1804        dyn_cast<ObjCCategoryImplDecl>(IMPDecl))
1805    CheckCategoryVsClassMethodMatches(CatDecl);
1806
1807  // Check the protocol list for unimplemented methods in the @implementation
1808  // class.
1809  // Check and see if class methods in class interface have been
1810  // implemented in the implementation class.
1811
1812  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) {
1813    for (ObjCInterfaceDecl::all_protocol_iterator
1814          PI = I->all_referenced_protocol_begin(),
1815          E = I->all_referenced_protocol_end(); PI != E; ++PI)
1816      CheckProtocolMethodDefs(IMPDecl->getLocation(), *PI, IncompleteImpl,
1817                              InsMap, ClsMap, I);
1818    // Check class extensions (unnamed categories)
1819    for (const ObjCCategoryDecl *Categories = I->getFirstClassExtension();
1820         Categories; Categories = Categories->getNextClassExtension())
1821      ImplMethodsVsClassMethods(S, IMPDecl,
1822                                const_cast<ObjCCategoryDecl*>(Categories),
1823                                IncompleteImpl);
1824  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1825    // For extended class, unimplemented methods in its protocols will
1826    // be reported in the primary class.
1827    if (!C->IsClassExtension()) {
1828      for (ObjCCategoryDecl::protocol_iterator PI = C->protocol_begin(),
1829           E = C->protocol_end(); PI != E; ++PI)
1830        CheckProtocolMethodDefs(IMPDecl->getLocation(), *PI, IncompleteImpl,
1831                                InsMap, ClsMap, CDecl);
1832      // Report unimplemented properties in the category as well.
1833      // When reporting on missing setter/getters, do not report when
1834      // setter/getter is implemented in category's primary class
1835      // implementation.
1836      if (ObjCInterfaceDecl *ID = C->getClassInterface())
1837        if (ObjCImplDecl *IMP = ID->getImplementation()) {
1838          for (ObjCImplementationDecl::instmeth_iterator
1839               I = IMP->instmeth_begin(), E = IMP->instmeth_end(); I!=E; ++I)
1840            InsMap.insert((*I)->getSelector());
1841        }
1842      DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, InsMap);
1843    }
1844  } else
1845    llvm_unreachable("invalid ObjCContainerDecl type.");
1846}
1847
1848/// ActOnForwardClassDeclaration -
1849Sema::DeclGroupPtrTy
1850Sema::ActOnForwardClassDeclaration(SourceLocation AtClassLoc,
1851                                   IdentifierInfo **IdentList,
1852                                   SourceLocation *IdentLocs,
1853                                   unsigned NumElts) {
1854  SmallVector<Decl *, 8> DeclsInGroup;
1855  for (unsigned i = 0; i != NumElts; ++i) {
1856    // Check for another declaration kind with the same name.
1857    NamedDecl *PrevDecl
1858      = LookupSingleName(TUScope, IdentList[i], IdentLocs[i],
1859                         LookupOrdinaryName, ForRedeclaration);
1860    if (PrevDecl && PrevDecl->isTemplateParameter()) {
1861      // Maybe we will complain about the shadowed template parameter.
1862      DiagnoseTemplateParameterShadow(AtClassLoc, PrevDecl);
1863      // Just pretend that we didn't see the previous declaration.
1864      PrevDecl = 0;
1865    }
1866
1867    if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
1868      // GCC apparently allows the following idiom:
1869      //
1870      // typedef NSObject < XCElementTogglerP > XCElementToggler;
1871      // @class XCElementToggler;
1872      //
1873      // Here we have chosen to ignore the forward class declaration
1874      // with a warning. Since this is the implied behavior.
1875      TypedefNameDecl *TDD = dyn_cast<TypedefNameDecl>(PrevDecl);
1876      if (!TDD || !TDD->getUnderlyingType()->isObjCObjectType()) {
1877        Diag(AtClassLoc, diag::err_redefinition_different_kind) << IdentList[i];
1878        Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1879      } else {
1880        // a forward class declaration matching a typedef name of a class refers
1881        // to the underlying class. Just ignore the forward class with a warning
1882        // as this will force the intended behavior which is to lookup the typedef
1883        // name.
1884        if (isa<ObjCObjectType>(TDD->getUnderlyingType())) {
1885          Diag(AtClassLoc, diag::warn_forward_class_redefinition) << IdentList[i];
1886          Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1887          continue;
1888        }
1889      }
1890    }
1891
1892    // Create a declaration to describe this forward declaration.
1893    ObjCInterfaceDecl *PrevIDecl
1894      = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl);
1895    ObjCInterfaceDecl *IDecl
1896      = ObjCInterfaceDecl::Create(Context, CurContext, AtClassLoc,
1897                                  IdentList[i], PrevIDecl, IdentLocs[i]);
1898    IDecl->setAtEndRange(IdentLocs[i]);
1899
1900    PushOnScopeChains(IDecl, TUScope);
1901    CheckObjCDeclScope(IDecl);
1902    DeclsInGroup.push_back(IDecl);
1903  }
1904
1905  return BuildDeclaratorGroup(DeclsInGroup.data(), DeclsInGroup.size(), false);
1906}
1907
1908static bool tryMatchRecordTypes(ASTContext &Context,
1909                                Sema::MethodMatchStrategy strategy,
1910                                const Type *left, const Type *right);
1911
1912static bool matchTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy,
1913                       QualType leftQT, QualType rightQT) {
1914  const Type *left =
1915    Context.getCanonicalType(leftQT).getUnqualifiedType().getTypePtr();
1916  const Type *right =
1917    Context.getCanonicalType(rightQT).getUnqualifiedType().getTypePtr();
1918
1919  if (left == right) return true;
1920
1921  // If we're doing a strict match, the types have to match exactly.
1922  if (strategy == Sema::MMS_strict) return false;
1923
1924  if (left->isIncompleteType() || right->isIncompleteType()) return false;
1925
1926  // Otherwise, use this absurdly complicated algorithm to try to
1927  // validate the basic, low-level compatibility of the two types.
1928
1929  // As a minimum, require the sizes and alignments to match.
1930  if (Context.getTypeInfo(left) != Context.getTypeInfo(right))
1931    return false;
1932
1933  // Consider all the kinds of non-dependent canonical types:
1934  // - functions and arrays aren't possible as return and parameter types
1935
1936  // - vector types of equal size can be arbitrarily mixed
1937  if (isa<VectorType>(left)) return isa<VectorType>(right);
1938  if (isa<VectorType>(right)) return false;
1939
1940  // - references should only match references of identical type
1941  // - structs, unions, and Objective-C objects must match more-or-less
1942  //   exactly
1943  // - everything else should be a scalar
1944  if (!left->isScalarType() || !right->isScalarType())
1945    return tryMatchRecordTypes(Context, strategy, left, right);
1946
1947  // Make scalars agree in kind, except count bools as chars, and group
1948  // all non-member pointers together.
1949  Type::ScalarTypeKind leftSK = left->getScalarTypeKind();
1950  Type::ScalarTypeKind rightSK = right->getScalarTypeKind();
1951  if (leftSK == Type::STK_Bool) leftSK = Type::STK_Integral;
1952  if (rightSK == Type::STK_Bool) rightSK = Type::STK_Integral;
1953  if (leftSK == Type::STK_CPointer || leftSK == Type::STK_BlockPointer)
1954    leftSK = Type::STK_ObjCObjectPointer;
1955  if (rightSK == Type::STK_CPointer || rightSK == Type::STK_BlockPointer)
1956    rightSK = Type::STK_ObjCObjectPointer;
1957
1958  // Note that data member pointers and function member pointers don't
1959  // intermix because of the size differences.
1960
1961  return (leftSK == rightSK);
1962}
1963
1964static bool tryMatchRecordTypes(ASTContext &Context,
1965                                Sema::MethodMatchStrategy strategy,
1966                                const Type *lt, const Type *rt) {
1967  assert(lt && rt && lt != rt);
1968
1969  if (!isa<RecordType>(lt) || !isa<RecordType>(rt)) return false;
1970  RecordDecl *left = cast<RecordType>(lt)->getDecl();
1971  RecordDecl *right = cast<RecordType>(rt)->getDecl();
1972
1973  // Require union-hood to match.
1974  if (left->isUnion() != right->isUnion()) return false;
1975
1976  // Require an exact match if either is non-POD.
1977  if ((isa<CXXRecordDecl>(left) && !cast<CXXRecordDecl>(left)->isPOD()) ||
1978      (isa<CXXRecordDecl>(right) && !cast<CXXRecordDecl>(right)->isPOD()))
1979    return false;
1980
1981  // Require size and alignment to match.
1982  if (Context.getTypeInfo(lt) != Context.getTypeInfo(rt)) return false;
1983
1984  // Require fields to match.
1985  RecordDecl::field_iterator li = left->field_begin(), le = left->field_end();
1986  RecordDecl::field_iterator ri = right->field_begin(), re = right->field_end();
1987  for (; li != le && ri != re; ++li, ++ri) {
1988    if (!matchTypes(Context, strategy, li->getType(), ri->getType()))
1989      return false;
1990  }
1991  return (li == le && ri == re);
1992}
1993
1994/// MatchTwoMethodDeclarations - Checks that two methods have matching type and
1995/// returns true, or false, accordingly.
1996/// TODO: Handle protocol list; such as id<p1,p2> in type comparisons
1997bool Sema::MatchTwoMethodDeclarations(const ObjCMethodDecl *left,
1998                                      const ObjCMethodDecl *right,
1999                                      MethodMatchStrategy strategy) {
2000  if (!matchTypes(Context, strategy,
2001                  left->getResultType(), right->getResultType()))
2002    return false;
2003
2004  if (getLangOpts().ObjCAutoRefCount &&
2005      (left->hasAttr<NSReturnsRetainedAttr>()
2006         != right->hasAttr<NSReturnsRetainedAttr>() ||
2007       left->hasAttr<NSConsumesSelfAttr>()
2008         != right->hasAttr<NSConsumesSelfAttr>()))
2009    return false;
2010
2011  ObjCMethodDecl::param_const_iterator
2012    li = left->param_begin(), le = left->param_end(), ri = right->param_begin(),
2013    re = right->param_end();
2014
2015  for (; li != le && ri != re; ++li, ++ri) {
2016    assert(ri != right->param_end() && "Param mismatch");
2017    const ParmVarDecl *lparm = *li, *rparm = *ri;
2018
2019    if (!matchTypes(Context, strategy, lparm->getType(), rparm->getType()))
2020      return false;
2021
2022    if (getLangOpts().ObjCAutoRefCount &&
2023        lparm->hasAttr<NSConsumedAttr>() != rparm->hasAttr<NSConsumedAttr>())
2024      return false;
2025  }
2026  return true;
2027}
2028
2029void Sema::addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method) {
2030  // If the list is empty, make it a singleton list.
2031  if (List->Method == 0) {
2032    List->Method = Method;
2033    List->Next = 0;
2034    return;
2035  }
2036
2037  // We've seen a method with this name, see if we have already seen this type
2038  // signature.
2039  ObjCMethodList *Previous = List;
2040  for (; List; Previous = List, List = List->Next) {
2041    if (!MatchTwoMethodDeclarations(Method, List->Method))
2042      continue;
2043
2044    ObjCMethodDecl *PrevObjCMethod = List->Method;
2045
2046    // Propagate the 'defined' bit.
2047    if (Method->isDefined())
2048      PrevObjCMethod->setDefined(true);
2049
2050    // If a method is deprecated, push it in the global pool.
2051    // This is used for better diagnostics.
2052    if (Method->isDeprecated()) {
2053      if (!PrevObjCMethod->isDeprecated())
2054        List->Method = Method;
2055    }
2056    // If new method is unavailable, push it into global pool
2057    // unless previous one is deprecated.
2058    if (Method->isUnavailable()) {
2059      if (PrevObjCMethod->getAvailability() < AR_Deprecated)
2060        List->Method = Method;
2061    }
2062
2063    return;
2064  }
2065
2066  // We have a new signature for an existing method - add it.
2067  // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
2068  ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
2069  Previous->Next = new (Mem) ObjCMethodList(Method, 0);
2070}
2071
2072/// \brief Read the contents of the method pool for a given selector from
2073/// external storage.
2074void Sema::ReadMethodPool(Selector Sel) {
2075  assert(ExternalSource && "We need an external AST source");
2076  ExternalSource->ReadMethodPool(Sel);
2077}
2078
2079void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
2080                                 bool instance) {
2081  // Ignore methods of invalid containers.
2082  if (cast<Decl>(Method->getDeclContext())->isInvalidDecl())
2083    return;
2084
2085  if (ExternalSource)
2086    ReadMethodPool(Method->getSelector());
2087
2088  GlobalMethodPool::iterator Pos = MethodPool.find(Method->getSelector());
2089  if (Pos == MethodPool.end())
2090    Pos = MethodPool.insert(std::make_pair(Method->getSelector(),
2091                                           GlobalMethods())).first;
2092
2093  Method->setDefined(impl);
2094
2095  ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second;
2096  addMethodToGlobalList(&Entry, Method);
2097}
2098
2099/// Determines if this is an "acceptable" loose mismatch in the global
2100/// method pool.  This exists mostly as a hack to get around certain
2101/// global mismatches which we can't afford to make warnings / errors.
2102/// Really, what we want is a way to take a method out of the global
2103/// method pool.
2104static bool isAcceptableMethodMismatch(ObjCMethodDecl *chosen,
2105                                       ObjCMethodDecl *other) {
2106  if (!chosen->isInstanceMethod())
2107    return false;
2108
2109  Selector sel = chosen->getSelector();
2110  if (!sel.isUnarySelector() || sel.getNameForSlot(0) != "length")
2111    return false;
2112
2113  // Don't complain about mismatches for -length if the method we
2114  // chose has an integral result type.
2115  return (chosen->getResultType()->isIntegerType());
2116}
2117
2118ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R,
2119                                               bool receiverIdOrClass,
2120                                               bool warn, bool instance) {
2121  if (ExternalSource)
2122    ReadMethodPool(Sel);
2123
2124  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
2125  if (Pos == MethodPool.end())
2126    return 0;
2127
2128  ObjCMethodList &MethList = instance ? Pos->second.first : Pos->second.second;
2129
2130  if (warn && MethList.Method && MethList.Next) {
2131    bool issueDiagnostic = false, issueError = false;
2132
2133    // We support a warning which complains about *any* difference in
2134    // method signature.
2135    bool strictSelectorMatch =
2136      (receiverIdOrClass && warn &&
2137       (Diags.getDiagnosticLevel(diag::warn_strict_multiple_method_decl,
2138                                 R.getBegin()) !=
2139      DiagnosticsEngine::Ignored));
2140    if (strictSelectorMatch)
2141      for (ObjCMethodList *Next = MethList.Next; Next; Next = Next->Next) {
2142        if (!MatchTwoMethodDeclarations(MethList.Method, Next->Method,
2143                                        MMS_strict)) {
2144          issueDiagnostic = true;
2145          break;
2146        }
2147      }
2148
2149    // If we didn't see any strict differences, we won't see any loose
2150    // differences.  In ARC, however, we also need to check for loose
2151    // mismatches, because most of them are errors.
2152    if (!strictSelectorMatch ||
2153        (issueDiagnostic && getLangOpts().ObjCAutoRefCount))
2154      for (ObjCMethodList *Next = MethList.Next; Next; Next = Next->Next) {
2155        // This checks if the methods differ in type mismatch.
2156        if (!MatchTwoMethodDeclarations(MethList.Method, Next->Method,
2157                                        MMS_loose) &&
2158            !isAcceptableMethodMismatch(MethList.Method, Next->Method)) {
2159          issueDiagnostic = true;
2160          if (getLangOpts().ObjCAutoRefCount)
2161            issueError = true;
2162          break;
2163        }
2164      }
2165
2166    if (issueDiagnostic) {
2167      if (issueError)
2168        Diag(R.getBegin(), diag::err_arc_multiple_method_decl) << Sel << R;
2169      else if (strictSelectorMatch)
2170        Diag(R.getBegin(), diag::warn_strict_multiple_method_decl) << Sel << R;
2171      else
2172        Diag(R.getBegin(), diag::warn_multiple_method_decl) << Sel << R;
2173
2174      Diag(MethList.Method->getLocStart(),
2175           issueError ? diag::note_possibility : diag::note_using)
2176        << MethList.Method->getSourceRange();
2177      for (ObjCMethodList *Next = MethList.Next; Next; Next = Next->Next)
2178        Diag(Next->Method->getLocStart(), diag::note_also_found)
2179          << Next->Method->getSourceRange();
2180    }
2181  }
2182  return MethList.Method;
2183}
2184
2185ObjCMethodDecl *Sema::LookupImplementedMethodInGlobalPool(Selector Sel) {
2186  GlobalMethodPool::iterator Pos = MethodPool.find(Sel);
2187  if (Pos == MethodPool.end())
2188    return 0;
2189
2190  GlobalMethods &Methods = Pos->second;
2191
2192  if (Methods.first.Method && Methods.first.Method->isDefined())
2193    return Methods.first.Method;
2194  if (Methods.second.Method && Methods.second.Method->isDefined())
2195    return Methods.second.Method;
2196  return 0;
2197}
2198
2199/// DiagnoseDuplicateIvars -
2200/// Check for duplicate ivars in the entire class at the start of
2201/// \@implementation. This becomes necesssary because class extension can
2202/// add ivars to a class in random order which will not be known until
2203/// class's \@implementation is seen.
2204void Sema::DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID,
2205                                  ObjCInterfaceDecl *SID) {
2206  for (ObjCInterfaceDecl::ivar_iterator IVI = ID->ivar_begin(),
2207       IVE = ID->ivar_end(); IVI != IVE; ++IVI) {
2208    ObjCIvarDecl* Ivar = *IVI;
2209    if (Ivar->isInvalidDecl())
2210      continue;
2211    if (IdentifierInfo *II = Ivar->getIdentifier()) {
2212      ObjCIvarDecl* prevIvar = SID->lookupInstanceVariable(II);
2213      if (prevIvar) {
2214        Diag(Ivar->getLocation(), diag::err_duplicate_member) << II;
2215        Diag(prevIvar->getLocation(), diag::note_previous_declaration);
2216        Ivar->setInvalidDecl();
2217      }
2218    }
2219  }
2220}
2221
2222Sema::ObjCContainerKind Sema::getObjCContainerKind() const {
2223  switch (CurContext->getDeclKind()) {
2224    case Decl::ObjCInterface:
2225      return Sema::OCK_Interface;
2226    case Decl::ObjCProtocol:
2227      return Sema::OCK_Protocol;
2228    case Decl::ObjCCategory:
2229      if (dyn_cast<ObjCCategoryDecl>(CurContext)->IsClassExtension())
2230        return Sema::OCK_ClassExtension;
2231      else
2232        return Sema::OCK_Category;
2233    case Decl::ObjCImplementation:
2234      return Sema::OCK_Implementation;
2235    case Decl::ObjCCategoryImpl:
2236      return Sema::OCK_CategoryImplementation;
2237
2238    default:
2239      return Sema::OCK_None;
2240  }
2241}
2242
2243// Note: For class/category implemenations, allMethods/allProperties is
2244// always null.
2245Decl *Sema::ActOnAtEnd(Scope *S, SourceRange AtEnd,
2246                       Decl **allMethods, unsigned allNum,
2247                       Decl **allProperties, unsigned pNum,
2248                       DeclGroupPtrTy *allTUVars, unsigned tuvNum) {
2249
2250  if (getObjCContainerKind() == Sema::OCK_None)
2251    return 0;
2252
2253  assert(AtEnd.isValid() && "Invalid location for '@end'");
2254
2255  ObjCContainerDecl *OCD = dyn_cast<ObjCContainerDecl>(CurContext);
2256  Decl *ClassDecl = cast<Decl>(OCD);
2257
2258  bool isInterfaceDeclKind =
2259        isa<ObjCInterfaceDecl>(ClassDecl) || isa<ObjCCategoryDecl>(ClassDecl)
2260         || isa<ObjCProtocolDecl>(ClassDecl);
2261  bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl);
2262
2263  // FIXME: Remove these and use the ObjCContainerDecl/DeclContext.
2264  llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap;
2265  llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap;
2266
2267  for (unsigned i = 0; i < allNum; i++ ) {
2268    ObjCMethodDecl *Method =
2269      cast_or_null<ObjCMethodDecl>(allMethods[i]);
2270
2271    if (!Method) continue;  // Already issued a diagnostic.
2272    if (Method->isInstanceMethod()) {
2273      /// Check for instance method of the same name with incompatible types
2274      const ObjCMethodDecl *&PrevMethod = InsMap[Method->getSelector()];
2275      bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
2276                              : false;
2277      if ((isInterfaceDeclKind && PrevMethod && !match)
2278          || (checkIdenticalMethods && match)) {
2279          Diag(Method->getLocation(), diag::err_duplicate_method_decl)
2280            << Method->getDeclName();
2281          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
2282        Method->setInvalidDecl();
2283      } else {
2284        if (PrevMethod) {
2285          Method->setAsRedeclaration(PrevMethod);
2286          if (!Context.getSourceManager().isInSystemHeader(
2287                 Method->getLocation()))
2288            Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
2289              << Method->getDeclName();
2290          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
2291        }
2292        InsMap[Method->getSelector()] = Method;
2293        /// The following allows us to typecheck messages to "id".
2294        AddInstanceMethodToGlobalPool(Method);
2295      }
2296    } else {
2297      /// Check for class method of the same name with incompatible types
2298      const ObjCMethodDecl *&PrevMethod = ClsMap[Method->getSelector()];
2299      bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod)
2300                              : false;
2301      if ((isInterfaceDeclKind && PrevMethod && !match)
2302          || (checkIdenticalMethods && match)) {
2303        Diag(Method->getLocation(), diag::err_duplicate_method_decl)
2304          << Method->getDeclName();
2305        Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
2306        Method->setInvalidDecl();
2307      } else {
2308        if (PrevMethod) {
2309          Method->setAsRedeclaration(PrevMethod);
2310          if (!Context.getSourceManager().isInSystemHeader(
2311                 Method->getLocation()))
2312            Diag(Method->getLocation(), diag::warn_duplicate_method_decl)
2313              << Method->getDeclName();
2314          Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
2315        }
2316        ClsMap[Method->getSelector()] = Method;
2317        AddFactoryMethodToGlobalPool(Method);
2318      }
2319    }
2320  }
2321  if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) {
2322    // Compares properties declared in this class to those of its
2323    // super class.
2324    ComparePropertiesInBaseAndSuper(I);
2325    CompareProperties(I, I);
2326  } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(ClassDecl)) {
2327    // Categories are used to extend the class by declaring new methods.
2328    // By the same token, they are also used to add new properties. No
2329    // need to compare the added property to those in the class.
2330
2331    // Compare protocol properties with those in category
2332    CompareProperties(C, C);
2333    if (C->IsClassExtension()) {
2334      ObjCInterfaceDecl *CCPrimary = C->getClassInterface();
2335      DiagnoseClassExtensionDupMethods(C, CCPrimary);
2336    }
2337  }
2338  if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) {
2339    if (CDecl->getIdentifier())
2340      // ProcessPropertyDecl is responsible for diagnosing conflicts with any
2341      // user-defined setter/getter. It also synthesizes setter/getter methods
2342      // and adds them to the DeclContext and global method pools.
2343      for (ObjCContainerDecl::prop_iterator I = CDecl->prop_begin(),
2344                                            E = CDecl->prop_end();
2345           I != E; ++I)
2346        ProcessPropertyDecl(*I, CDecl);
2347    CDecl->setAtEndRange(AtEnd);
2348  }
2349  if (ObjCImplementationDecl *IC=dyn_cast<ObjCImplementationDecl>(ClassDecl)) {
2350    IC->setAtEndRange(AtEnd);
2351    if (ObjCInterfaceDecl* IDecl = IC->getClassInterface()) {
2352      // Any property declared in a class extension might have user
2353      // declared setter or getter in current class extension or one
2354      // of the other class extensions. Mark them as synthesized as
2355      // property will be synthesized when property with same name is
2356      // seen in the @implementation.
2357      for (const ObjCCategoryDecl *ClsExtDecl =
2358           IDecl->getFirstClassExtension();
2359           ClsExtDecl; ClsExtDecl = ClsExtDecl->getNextClassExtension()) {
2360        for (ObjCContainerDecl::prop_iterator I = ClsExtDecl->prop_begin(),
2361             E = ClsExtDecl->prop_end(); I != E; ++I) {
2362          ObjCPropertyDecl *Property = *I;
2363          // Skip over properties declared @dynamic
2364          if (const ObjCPropertyImplDecl *PIDecl
2365              = IC->FindPropertyImplDecl(Property->getIdentifier()))
2366            if (PIDecl->getPropertyImplementation()
2367                  == ObjCPropertyImplDecl::Dynamic)
2368              continue;
2369
2370          for (const ObjCCategoryDecl *CExtDecl =
2371               IDecl->getFirstClassExtension();
2372               CExtDecl; CExtDecl = CExtDecl->getNextClassExtension()) {
2373            if (ObjCMethodDecl *GetterMethod =
2374                CExtDecl->getInstanceMethod(Property->getGetterName()))
2375              GetterMethod->setPropertyAccessor(true);
2376            if (!Property->isReadOnly())
2377              if (ObjCMethodDecl *SetterMethod =
2378                  CExtDecl->getInstanceMethod(Property->getSetterName()))
2379                SetterMethod->setPropertyAccessor(true);
2380          }
2381        }
2382      }
2383      ImplMethodsVsClassMethods(S, IC, IDecl);
2384      AtomicPropertySetterGetterRules(IC, IDecl);
2385      DiagnoseOwningPropertyGetterSynthesis(IC);
2386
2387      bool HasRootClassAttr = IDecl->hasAttr<ObjCRootClassAttr>();
2388      if (IDecl->getSuperClass() == NULL) {
2389        // This class has no superclass, so check that it has been marked with
2390        // __attribute((objc_root_class)).
2391        if (!HasRootClassAttr) {
2392          SourceLocation DeclLoc(IDecl->getLocation());
2393          SourceLocation SuperClassLoc(PP.getLocForEndOfToken(DeclLoc));
2394          Diag(DeclLoc, diag::warn_objc_root_class_missing)
2395            << IDecl->getIdentifier();
2396          // See if NSObject is in the current scope, and if it is, suggest
2397          // adding " : NSObject " to the class declaration.
2398          NamedDecl *IF = LookupSingleName(TUScope,
2399                                           NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject),
2400                                           DeclLoc, LookupOrdinaryName);
2401          ObjCInterfaceDecl *NSObjectDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
2402          if (NSObjectDecl && NSObjectDecl->getDefinition()) {
2403            Diag(SuperClassLoc, diag::note_objc_needs_superclass)
2404              << FixItHint::CreateInsertion(SuperClassLoc, " : NSObject ");
2405          } else {
2406            Diag(SuperClassLoc, diag::note_objc_needs_superclass);
2407          }
2408        }
2409      } else if (HasRootClassAttr) {
2410        // Complain that only root classes may have this attribute.
2411        Diag(IDecl->getLocation(), diag::err_objc_root_class_subclass);
2412      }
2413
2414      if (LangOpts.ObjCRuntime.isNonFragile()) {
2415        while (IDecl->getSuperClass()) {
2416          DiagnoseDuplicateIvars(IDecl, IDecl->getSuperClass());
2417          IDecl = IDecl->getSuperClass();
2418        }
2419      }
2420    }
2421    SetIvarInitializers(IC);
2422  } else if (ObjCCategoryImplDecl* CatImplClass =
2423                                   dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) {
2424    CatImplClass->setAtEndRange(AtEnd);
2425
2426    // Find category interface decl and then check that all methods declared
2427    // in this interface are implemented in the category @implementation.
2428    if (ObjCInterfaceDecl* IDecl = CatImplClass->getClassInterface()) {
2429      for (ObjCCategoryDecl *Categories = IDecl->getCategoryList();
2430           Categories; Categories = Categories->getNextClassCategory()) {
2431        if (Categories->getIdentifier() == CatImplClass->getIdentifier()) {
2432          ImplMethodsVsClassMethods(S, CatImplClass, Categories);
2433          break;
2434        }
2435      }
2436    }
2437  }
2438  if (isInterfaceDeclKind) {
2439    // Reject invalid vardecls.
2440    for (unsigned i = 0; i != tuvNum; i++) {
2441      DeclGroupRef DG = allTUVars[i].getAsVal<DeclGroupRef>();
2442      for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
2443        if (VarDecl *VDecl = dyn_cast<VarDecl>(*I)) {
2444          if (!VDecl->hasExternalStorage())
2445            Diag(VDecl->getLocation(), diag::err_objc_var_decl_inclass);
2446        }
2447    }
2448  }
2449  ActOnObjCContainerFinishDefinition();
2450
2451  for (unsigned i = 0; i != tuvNum; i++) {
2452    DeclGroupRef DG = allTUVars[i].getAsVal<DeclGroupRef>();
2453    for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
2454      (*I)->setTopLevelDeclInObjCContainer();
2455    Consumer.HandleTopLevelDeclInObjCContainer(DG);
2456  }
2457
2458  ActOnDocumentableDecl(ClassDecl);
2459  return ClassDecl;
2460}
2461
2462
2463/// CvtQTToAstBitMask - utility routine to produce an AST bitmask for
2464/// objective-c's type qualifier from the parser version of the same info.
2465static Decl::ObjCDeclQualifier
2466CvtQTToAstBitMask(ObjCDeclSpec::ObjCDeclQualifier PQTVal) {
2467  return (Decl::ObjCDeclQualifier) (unsigned) PQTVal;
2468}
2469
2470static inline
2471unsigned countAlignAttr(const AttrVec &A) {
2472  unsigned count=0;
2473  for (AttrVec::const_iterator i = A.begin(), e = A.end(); i != e; ++i)
2474    if ((*i)->getKind() == attr::Aligned)
2475      ++count;
2476  return count;
2477}
2478
2479static inline
2480bool containsInvalidMethodImplAttribute(ObjCMethodDecl *IMD,
2481                                        const AttrVec &A) {
2482  // If method is only declared in implementation (private method),
2483  // No need to issue any diagnostics on method definition with attributes.
2484  if (!IMD)
2485    return false;
2486
2487  // method declared in interface has no attribute.
2488  // But implementation has attributes. This is invalid.
2489  // Except when implementation has 'Align' attribute which is
2490  // immaterial to method declared in interface.
2491  if (!IMD->hasAttrs())
2492    return (A.size() > countAlignAttr(A));
2493
2494  const AttrVec &D = IMD->getAttrs();
2495
2496  unsigned countAlignOnImpl = countAlignAttr(A);
2497  if (!countAlignOnImpl && (A.size() != D.size()))
2498    return true;
2499  else if (countAlignOnImpl) {
2500    unsigned countAlignOnDecl = countAlignAttr(D);
2501    if (countAlignOnDecl && (A.size() != D.size()))
2502      return true;
2503    else if (!countAlignOnDecl &&
2504             ((A.size()-countAlignOnImpl) != D.size()))
2505      return true;
2506  }
2507
2508  // attributes on method declaration and definition must match exactly.
2509  // Note that we have at most a couple of attributes on methods, so this
2510  // n*n search is good enough.
2511  for (AttrVec::const_iterator i = A.begin(), e = A.end(); i != e; ++i) {
2512    if ((*i)->getKind() == attr::Aligned)
2513      continue;
2514    bool match = false;
2515    for (AttrVec::const_iterator i1 = D.begin(), e1 = D.end(); i1 != e1; ++i1) {
2516      if ((*i)->getKind() == (*i1)->getKind()) {
2517        match = true;
2518        break;
2519      }
2520    }
2521    if (!match)
2522      return true;
2523  }
2524
2525  return false;
2526}
2527
2528/// \brief Check whether the declared result type of the given Objective-C
2529/// method declaration is compatible with the method's class.
2530///
2531static Sema::ResultTypeCompatibilityKind
2532CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method,
2533                                    ObjCInterfaceDecl *CurrentClass) {
2534  QualType ResultType = Method->getResultType();
2535
2536  // If an Objective-C method inherits its related result type, then its
2537  // declared result type must be compatible with its own class type. The
2538  // declared result type is compatible if:
2539  if (const ObjCObjectPointerType *ResultObjectType
2540                                = ResultType->getAs<ObjCObjectPointerType>()) {
2541    //   - it is id or qualified id, or
2542    if (ResultObjectType->isObjCIdType() ||
2543        ResultObjectType->isObjCQualifiedIdType())
2544      return Sema::RTC_Compatible;
2545
2546    if (CurrentClass) {
2547      if (ObjCInterfaceDecl *ResultClass
2548                                      = ResultObjectType->getInterfaceDecl()) {
2549        //   - it is the same as the method's class type, or
2550        if (declaresSameEntity(CurrentClass, ResultClass))
2551          return Sema::RTC_Compatible;
2552
2553        //   - it is a superclass of the method's class type
2554        if (ResultClass->isSuperClassOf(CurrentClass))
2555          return Sema::RTC_Compatible;
2556      }
2557    } else {
2558      // Any Objective-C pointer type might be acceptable for a protocol
2559      // method; we just don't know.
2560      return Sema::RTC_Unknown;
2561    }
2562  }
2563
2564  return Sema::RTC_Incompatible;
2565}
2566
2567namespace {
2568/// A helper class for searching for methods which a particular method
2569/// overrides.
2570class OverrideSearch {
2571public:
2572  Sema &S;
2573  ObjCMethodDecl *Method;
2574  llvm::SmallPtrSet<ObjCMethodDecl*, 4> Overridden;
2575  bool Recursive;
2576
2577public:
2578  OverrideSearch(Sema &S, ObjCMethodDecl *method) : S(S), Method(method) {
2579    Selector selector = method->getSelector();
2580
2581    // Bypass this search if we've never seen an instance/class method
2582    // with this selector before.
2583    Sema::GlobalMethodPool::iterator it = S.MethodPool.find(selector);
2584    if (it == S.MethodPool.end()) {
2585      if (!S.ExternalSource) return;
2586      S.ReadMethodPool(selector);
2587
2588      it = S.MethodPool.find(selector);
2589      if (it == S.MethodPool.end())
2590        return;
2591    }
2592    ObjCMethodList &list =
2593      method->isInstanceMethod() ? it->second.first : it->second.second;
2594    if (!list.Method) return;
2595
2596    ObjCContainerDecl *container
2597      = cast<ObjCContainerDecl>(method->getDeclContext());
2598
2599    // Prevent the search from reaching this container again.  This is
2600    // important with categories, which override methods from the
2601    // interface and each other.
2602    if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(container)) {
2603      searchFromContainer(container);
2604      if (ObjCInterfaceDecl *Interface = Category->getClassInterface())
2605        searchFromContainer(Interface);
2606    } else {
2607      searchFromContainer(container);
2608    }
2609  }
2610
2611  typedef llvm::SmallPtrSet<ObjCMethodDecl*, 128>::iterator iterator;
2612  iterator begin() const { return Overridden.begin(); }
2613  iterator end() const { return Overridden.end(); }
2614
2615private:
2616  void searchFromContainer(ObjCContainerDecl *container) {
2617    if (container->isInvalidDecl()) return;
2618
2619    switch (container->getDeclKind()) {
2620#define OBJCCONTAINER(type, base) \
2621    case Decl::type: \
2622      searchFrom(cast<type##Decl>(container)); \
2623      break;
2624#define ABSTRACT_DECL(expansion)
2625#define DECL(type, base) \
2626    case Decl::type:
2627#include "clang/AST/DeclNodes.inc"
2628      llvm_unreachable("not an ObjC container!");
2629    }
2630  }
2631
2632  void searchFrom(ObjCProtocolDecl *protocol) {
2633    if (!protocol->hasDefinition())
2634      return;
2635
2636    // A method in a protocol declaration overrides declarations from
2637    // referenced ("parent") protocols.
2638    search(protocol->getReferencedProtocols());
2639  }
2640
2641  void searchFrom(ObjCCategoryDecl *category) {
2642    // A method in a category declaration overrides declarations from
2643    // the main class and from protocols the category references.
2644    // The main class is handled in the constructor.
2645    search(category->getReferencedProtocols());
2646  }
2647
2648  void searchFrom(ObjCCategoryImplDecl *impl) {
2649    // A method in a category definition that has a category
2650    // declaration overrides declarations from the category
2651    // declaration.
2652    if (ObjCCategoryDecl *category = impl->getCategoryDecl()) {
2653      search(category);
2654      if (ObjCInterfaceDecl *Interface = category->getClassInterface())
2655        search(Interface);
2656
2657    // Otherwise it overrides declarations from the class.
2658    } else if (ObjCInterfaceDecl *Interface = impl->getClassInterface()) {
2659      search(Interface);
2660    }
2661  }
2662
2663  void searchFrom(ObjCInterfaceDecl *iface) {
2664    // A method in a class declaration overrides declarations from
2665    if (!iface->hasDefinition())
2666      return;
2667
2668    //   - categories,
2669    for (ObjCCategoryDecl *category = iface->getCategoryList();
2670           category; category = category->getNextClassCategory())
2671      search(category);
2672
2673    //   - the super class, and
2674    if (ObjCInterfaceDecl *super = iface->getSuperClass())
2675      search(super);
2676
2677    //   - any referenced protocols.
2678    search(iface->getReferencedProtocols());
2679  }
2680
2681  void searchFrom(ObjCImplementationDecl *impl) {
2682    // A method in a class implementation overrides declarations from
2683    // the class interface.
2684    if (ObjCInterfaceDecl *Interface = impl->getClassInterface())
2685      search(Interface);
2686  }
2687
2688
2689  void search(const ObjCProtocolList &protocols) {
2690    for (ObjCProtocolList::iterator i = protocols.begin(), e = protocols.end();
2691         i != e; ++i)
2692      search(*i);
2693  }
2694
2695  void search(ObjCContainerDecl *container) {
2696    // Check for a method in this container which matches this selector.
2697    ObjCMethodDecl *meth = container->getMethod(Method->getSelector(),
2698                                                Method->isInstanceMethod());
2699
2700    // If we find one, record it and bail out.
2701    if (meth) {
2702      Overridden.insert(meth);
2703      return;
2704    }
2705
2706    // Otherwise, search for methods that a hypothetical method here
2707    // would have overridden.
2708
2709    // Note that we're now in a recursive case.
2710    Recursive = true;
2711
2712    searchFromContainer(container);
2713  }
2714};
2715}
2716
2717void Sema::CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
2718                                    ObjCInterfaceDecl *CurrentClass,
2719                                    ResultTypeCompatibilityKind RTC) {
2720  // Search for overridden methods and merge information down from them.
2721  OverrideSearch overrides(*this, ObjCMethod);
2722  // Keep track if the method overrides any method in the class's base classes,
2723  // its protocols, or its categories' protocols; we will keep that info
2724  // in the ObjCMethodDecl.
2725  // For this info, a method in an implementation is not considered as
2726  // overriding the same method in the interface or its categories.
2727  bool hasOverriddenMethodsInBaseOrProtocol = false;
2728  for (OverrideSearch::iterator
2729         i = overrides.begin(), e = overrides.end(); i != e; ++i) {
2730    ObjCMethodDecl *overridden = *i;
2731
2732    if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) ||
2733        CurrentClass != overridden->getClassInterface() ||
2734        overridden->isOverriding())
2735      hasOverriddenMethodsInBaseOrProtocol = true;
2736
2737    // Propagate down the 'related result type' bit from overridden methods.
2738    if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType())
2739      ObjCMethod->SetRelatedResultType();
2740
2741    // Then merge the declarations.
2742    mergeObjCMethodDecls(ObjCMethod, overridden);
2743
2744    if (ObjCMethod->isImplicit() && overridden->isImplicit())
2745      continue; // Conflicting properties are detected elsewhere.
2746
2747    // Check for overriding methods
2748    if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) ||
2749        isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext()))
2750      CheckConflictingOverridingMethod(ObjCMethod, overridden,
2751              isa<ObjCProtocolDecl>(overridden->getDeclContext()));
2752
2753    if (CurrentClass && overridden->getDeclContext() != CurrentClass &&
2754        isa<ObjCInterfaceDecl>(overridden->getDeclContext()) &&
2755        !overridden->isImplicit() /* not meant for properties */) {
2756      ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(),
2757                                          E = ObjCMethod->param_end();
2758      ObjCMethodDecl::param_iterator PrevI = overridden->param_begin(),
2759                                     PrevE = overridden->param_end();
2760      for (; ParamI != E && PrevI != PrevE; ++ParamI, ++PrevI) {
2761        assert(PrevI != overridden->param_end() && "Param mismatch");
2762        QualType T1 = Context.getCanonicalType((*ParamI)->getType());
2763        QualType T2 = Context.getCanonicalType((*PrevI)->getType());
2764        // If type of argument of method in this class does not match its
2765        // respective argument type in the super class method, issue warning;
2766        if (!Context.typesAreCompatible(T1, T2)) {
2767          Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
2768            << T1 << T2;
2769          Diag(overridden->getLocation(), diag::note_previous_declaration);
2770          break;
2771        }
2772      }
2773    }
2774  }
2775
2776  ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol);
2777}
2778
2779Decl *Sema::ActOnMethodDeclaration(
2780    Scope *S,
2781    SourceLocation MethodLoc, SourceLocation EndLoc,
2782    tok::TokenKind MethodType,
2783    ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
2784    ArrayRef<SourceLocation> SelectorLocs,
2785    Selector Sel,
2786    // optional arguments. The number of types/arguments is obtained
2787    // from the Sel.getNumArgs().
2788    ObjCArgInfo *ArgInfo,
2789    DeclaratorChunk::ParamInfo *CParamInfo, unsigned CNumArgs, // c-style args
2790    AttributeList *AttrList, tok::ObjCKeywordKind MethodDeclKind,
2791    bool isVariadic, bool MethodDefinition) {
2792  // Make sure we can establish a context for the method.
2793  if (!CurContext->isObjCContainer()) {
2794    Diag(MethodLoc, diag::error_missing_method_context);
2795    return 0;
2796  }
2797  ObjCContainerDecl *OCD = dyn_cast<ObjCContainerDecl>(CurContext);
2798  Decl *ClassDecl = cast<Decl>(OCD);
2799  QualType resultDeclType;
2800
2801  bool HasRelatedResultType = false;
2802  TypeSourceInfo *ResultTInfo = 0;
2803  if (ReturnType) {
2804    resultDeclType = GetTypeFromParser(ReturnType, &ResultTInfo);
2805
2806    // Methods cannot return interface types. All ObjC objects are
2807    // passed by reference.
2808    if (resultDeclType->isObjCObjectType()) {
2809      Diag(MethodLoc, diag::err_object_cannot_be_passed_returned_by_value)
2810        << 0 << resultDeclType;
2811      return 0;
2812    }
2813
2814    HasRelatedResultType = (resultDeclType == Context.getObjCInstanceType());
2815  } else { // get the type for "id".
2816    resultDeclType = Context.getObjCIdType();
2817    Diag(MethodLoc, diag::warn_missing_method_return_type)
2818      << FixItHint::CreateInsertion(SelectorLocs.front(), "(id)");
2819  }
2820
2821  ObjCMethodDecl* ObjCMethod =
2822    ObjCMethodDecl::Create(Context, MethodLoc, EndLoc, Sel,
2823                           resultDeclType,
2824                           ResultTInfo,
2825                           CurContext,
2826                           MethodType == tok::minus, isVariadic,
2827                           /*isPropertyAccessor=*/false,
2828                           /*isImplicitlyDeclared=*/false, /*isDefined=*/false,
2829                           MethodDeclKind == tok::objc_optional
2830                             ? ObjCMethodDecl::Optional
2831                             : ObjCMethodDecl::Required,
2832                           HasRelatedResultType);
2833
2834  SmallVector<ParmVarDecl*, 16> Params;
2835
2836  for (unsigned i = 0, e = Sel.getNumArgs(); i != e; ++i) {
2837    QualType ArgType;
2838    TypeSourceInfo *DI;
2839
2840    if (ArgInfo[i].Type == 0) {
2841      ArgType = Context.getObjCIdType();
2842      DI = 0;
2843    } else {
2844      ArgType = GetTypeFromParser(ArgInfo[i].Type, &DI);
2845      // Perform the default array/function conversions (C99 6.7.5.3p[7,8]).
2846      ArgType = Context.getAdjustedParameterType(ArgType);
2847    }
2848
2849    LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc,
2850                   LookupOrdinaryName, ForRedeclaration);
2851    LookupName(R, S);
2852    if (R.isSingleResult()) {
2853      NamedDecl *PrevDecl = R.getFoundDecl();
2854      if (S->isDeclScope(PrevDecl)) {
2855        Diag(ArgInfo[i].NameLoc,
2856             (MethodDefinition ? diag::warn_method_param_redefinition
2857                               : diag::warn_method_param_declaration))
2858          << ArgInfo[i].Name;
2859        Diag(PrevDecl->getLocation(),
2860             diag::note_previous_declaration);
2861      }
2862    }
2863
2864    SourceLocation StartLoc = DI
2865      ? DI->getTypeLoc().getBeginLoc()
2866      : ArgInfo[i].NameLoc;
2867
2868    ParmVarDecl* Param = CheckParameter(ObjCMethod, StartLoc,
2869                                        ArgInfo[i].NameLoc, ArgInfo[i].Name,
2870                                        ArgType, DI, SC_None, SC_None);
2871
2872    Param->setObjCMethodScopeInfo(i);
2873
2874    Param->setObjCDeclQualifier(
2875      CvtQTToAstBitMask(ArgInfo[i].DeclSpec.getObjCDeclQualifier()));
2876
2877    // Apply the attributes to the parameter.
2878    ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs);
2879
2880    if (Param->hasAttr<BlocksAttr>()) {
2881      Diag(Param->getLocation(), diag::err_block_on_nonlocal);
2882      Param->setInvalidDecl();
2883    }
2884    S->AddDecl(Param);
2885    IdResolver.AddDecl(Param);
2886
2887    Params.push_back(Param);
2888  }
2889
2890  for (unsigned i = 0, e = CNumArgs; i != e; ++i) {
2891    ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param);
2892    QualType ArgType = Param->getType();
2893    if (ArgType.isNull())
2894      ArgType = Context.getObjCIdType();
2895    else
2896      // Perform the default array/function conversions (C99 6.7.5.3p[7,8]).
2897      ArgType = Context.getAdjustedParameterType(ArgType);
2898    if (ArgType->isObjCObjectType()) {
2899      Diag(Param->getLocation(),
2900           diag::err_object_cannot_be_passed_returned_by_value)
2901      << 1 << ArgType;
2902      Param->setInvalidDecl();
2903    }
2904    Param->setDeclContext(ObjCMethod);
2905
2906    Params.push_back(Param);
2907  }
2908
2909  ObjCMethod->setMethodParams(Context, Params, SelectorLocs);
2910  ObjCMethod->setObjCDeclQualifier(
2911    CvtQTToAstBitMask(ReturnQT.getObjCDeclQualifier()));
2912
2913  if (AttrList)
2914    ProcessDeclAttributeList(TUScope, ObjCMethod, AttrList);
2915
2916  // Add the method now.
2917  const ObjCMethodDecl *PrevMethod = 0;
2918  if (ObjCImplDecl *ImpDecl = dyn_cast<ObjCImplDecl>(ClassDecl)) {
2919    if (MethodType == tok::minus) {
2920      PrevMethod = ImpDecl->getInstanceMethod(Sel);
2921      ImpDecl->addInstanceMethod(ObjCMethod);
2922    } else {
2923      PrevMethod = ImpDecl->getClassMethod(Sel);
2924      ImpDecl->addClassMethod(ObjCMethod);
2925    }
2926
2927    ObjCMethodDecl *IMD = 0;
2928    if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface())
2929      IMD = IDecl->lookupMethod(ObjCMethod->getSelector(),
2930                                ObjCMethod->isInstanceMethod());
2931    if (ObjCMethod->hasAttrs() &&
2932        containsInvalidMethodImplAttribute(IMD, ObjCMethod->getAttrs())) {
2933      SourceLocation MethodLoc = IMD->getLocation();
2934      if (!getSourceManager().isInSystemHeader(MethodLoc)) {
2935        Diag(EndLoc, diag::warn_attribute_method_def);
2936        Diag(MethodLoc, diag::note_method_declared_at)
2937          << ObjCMethod->getDeclName();
2938      }
2939    }
2940  } else {
2941    cast<DeclContext>(ClassDecl)->addDecl(ObjCMethod);
2942  }
2943
2944  if (PrevMethod) {
2945    // You can never have two method definitions with the same name.
2946    Diag(ObjCMethod->getLocation(), diag::err_duplicate_method_decl)
2947      << ObjCMethod->getDeclName();
2948    Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
2949  }
2950
2951  // If this Objective-C method does not have a related result type, but we
2952  // are allowed to infer related result types, try to do so based on the
2953  // method family.
2954  ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(ClassDecl);
2955  if (!CurrentClass) {
2956    if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl))
2957      CurrentClass = Cat->getClassInterface();
2958    else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(ClassDecl))
2959      CurrentClass = Impl->getClassInterface();
2960    else if (ObjCCategoryImplDecl *CatImpl
2961                                   = dyn_cast<ObjCCategoryImplDecl>(ClassDecl))
2962      CurrentClass = CatImpl->getClassInterface();
2963  }
2964
2965  ResultTypeCompatibilityKind RTC
2966    = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
2967
2968  CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC);
2969
2970  bool ARCError = false;
2971  if (getLangOpts().ObjCAutoRefCount)
2972    ARCError = CheckARCMethodDecl(*this, ObjCMethod);
2973
2974  // Infer the related result type when possible.
2975  if (!ARCError && RTC == Sema::RTC_Compatible &&
2976      !ObjCMethod->hasRelatedResultType() &&
2977      LangOpts.ObjCInferRelatedResultType) {
2978    bool InferRelatedResultType = false;
2979    switch (ObjCMethod->getMethodFamily()) {
2980    case OMF_None:
2981    case OMF_copy:
2982    case OMF_dealloc:
2983    case OMF_finalize:
2984    case OMF_mutableCopy:
2985    case OMF_release:
2986    case OMF_retainCount:
2987    case OMF_performSelector:
2988      break;
2989
2990    case OMF_alloc:
2991    case OMF_new:
2992      InferRelatedResultType = ObjCMethod->isClassMethod();
2993      break;
2994
2995    case OMF_init:
2996    case OMF_autorelease:
2997    case OMF_retain:
2998    case OMF_self:
2999      InferRelatedResultType = ObjCMethod->isInstanceMethod();
3000      break;
3001    }
3002
3003    if (InferRelatedResultType)
3004      ObjCMethod->SetRelatedResultType();
3005  }
3006
3007  ActOnDocumentableDecl(ObjCMethod);
3008
3009  return ObjCMethod;
3010}
3011
3012bool Sema::CheckObjCDeclScope(Decl *D) {
3013  // Following is also an error. But it is caused by a missing @end
3014  // and diagnostic is issued elsewhere.
3015  if (isa<ObjCContainerDecl>(CurContext->getRedeclContext()))
3016    return false;
3017
3018  // If we switched context to translation unit while we are still lexically in
3019  // an objc container, it means the parser missed emitting an error.
3020  if (isa<TranslationUnitDecl>(getCurLexicalContext()->getRedeclContext()))
3021    return false;
3022
3023  Diag(D->getLocation(), diag::err_objc_decls_may_only_appear_in_global_scope);
3024  D->setInvalidDecl();
3025
3026  return true;
3027}
3028
3029/// Called whenever \@defs(ClassName) is encountered in the source.  Inserts the
3030/// instance variables of ClassName into Decls.
3031void Sema::ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
3032                     IdentifierInfo *ClassName,
3033                     SmallVectorImpl<Decl*> &Decls) {
3034  // Check that ClassName is a valid class
3035  ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName, DeclStart);
3036  if (!Class) {
3037    Diag(DeclStart, diag::err_undef_interface) << ClassName;
3038    return;
3039  }
3040  if (LangOpts.ObjCRuntime.isNonFragile()) {
3041    Diag(DeclStart, diag::err_atdef_nonfragile_interface);
3042    return;
3043  }
3044
3045  // Collect the instance variables
3046  SmallVector<const ObjCIvarDecl*, 32> Ivars;
3047  Context.DeepCollectObjCIvars(Class, true, Ivars);
3048  // For each ivar, create a fresh ObjCAtDefsFieldDecl.
3049  for (unsigned i = 0; i < Ivars.size(); i++) {
3050    const FieldDecl* ID = cast<FieldDecl>(Ivars[i]);
3051    RecordDecl *Record = dyn_cast<RecordDecl>(TagD);
3052    Decl *FD = ObjCAtDefsFieldDecl::Create(Context, Record,
3053                                           /*FIXME: StartL=*/ID->getLocation(),
3054                                           ID->getLocation(),
3055                                           ID->getIdentifier(), ID->getType(),
3056                                           ID->getBitWidth());
3057    Decls.push_back(FD);
3058  }
3059
3060  // Introduce all of these fields into the appropriate scope.
3061  for (SmallVectorImpl<Decl*>::iterator D = Decls.begin();
3062       D != Decls.end(); ++D) {
3063    FieldDecl *FD = cast<FieldDecl>(*D);
3064    if (getLangOpts().CPlusPlus)
3065      PushOnScopeChains(cast<FieldDecl>(FD), S);
3066    else if (RecordDecl *Record = dyn_cast<RecordDecl>(TagD))
3067      Record->addDecl(FD);
3068  }
3069}
3070
3071/// \brief Build a type-check a new Objective-C exception variable declaration.
3072VarDecl *Sema::BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType T,
3073                                      SourceLocation StartLoc,
3074                                      SourceLocation IdLoc,
3075                                      IdentifierInfo *Id,
3076                                      bool Invalid) {
3077  // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
3078  // duration shall not be qualified by an address-space qualifier."
3079  // Since all parameters have automatic store duration, they can not have
3080  // an address space.
3081  if (T.getAddressSpace() != 0) {
3082    Diag(IdLoc, diag::err_arg_with_address_space);
3083    Invalid = true;
3084  }
3085
3086  // An @catch parameter must be an unqualified object pointer type;
3087  // FIXME: Recover from "NSObject foo" by inserting the * in "NSObject *foo"?
3088  if (Invalid) {
3089    // Don't do any further checking.
3090  } else if (T->isDependentType()) {
3091    // Okay: we don't know what this type will instantiate to.
3092  } else if (!T->isObjCObjectPointerType()) {
3093    Invalid = true;
3094    Diag(IdLoc ,diag::err_catch_param_not_objc_type);
3095  } else if (T->isObjCQualifiedIdType()) {
3096    Invalid = true;
3097    Diag(IdLoc, diag::err_illegal_qualifiers_on_catch_parm);
3098  }
3099
3100  VarDecl *New = VarDecl::Create(Context, CurContext, StartLoc, IdLoc, Id,
3101                                 T, TInfo, SC_None, SC_None);
3102  New->setExceptionVariable(true);
3103
3104  // In ARC, infer 'retaining' for variables of retainable type.
3105  if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(New))
3106    Invalid = true;
3107
3108  if (Invalid)
3109    New->setInvalidDecl();
3110  return New;
3111}
3112
3113Decl *Sema::ActOnObjCExceptionDecl(Scope *S, Declarator &D) {
3114  const DeclSpec &DS = D.getDeclSpec();
3115
3116  // We allow the "register" storage class on exception variables because
3117  // GCC did, but we drop it completely. Any other storage class is an error.
3118  if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
3119    Diag(DS.getStorageClassSpecLoc(), diag::warn_register_objc_catch_parm)
3120      << FixItHint::CreateRemoval(SourceRange(DS.getStorageClassSpecLoc()));
3121  } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
3122    Diag(DS.getStorageClassSpecLoc(), diag::err_storage_spec_on_catch_parm)
3123      << DS.getStorageClassSpec();
3124  }
3125  if (D.getDeclSpec().isThreadSpecified())
3126    Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
3127  D.getMutableDeclSpec().ClearStorageClassSpecs();
3128
3129  DiagnoseFunctionSpecifiers(D);
3130
3131  // Check that there are no default arguments inside the type of this
3132  // exception object (C++ only).
3133  if (getLangOpts().CPlusPlus)
3134    CheckExtraCXXDefaultArguments(D);
3135
3136  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
3137  QualType ExceptionType = TInfo->getType();
3138
3139  VarDecl *New = BuildObjCExceptionDecl(TInfo, ExceptionType,
3140                                        D.getSourceRange().getBegin(),
3141                                        D.getIdentifierLoc(),
3142                                        D.getIdentifier(),
3143                                        D.isInvalidType());
3144
3145  // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
3146  if (D.getCXXScopeSpec().isSet()) {
3147    Diag(D.getIdentifierLoc(), diag::err_qualified_objc_catch_parm)
3148      << D.getCXXScopeSpec().getRange();
3149    New->setInvalidDecl();
3150  }
3151
3152  // Add the parameter declaration into this scope.
3153  S->AddDecl(New);
3154  if (D.getIdentifier())
3155    IdResolver.AddDecl(New);
3156
3157  ProcessDeclAttributes(S, New, D);
3158
3159  if (New->hasAttr<BlocksAttr>())
3160    Diag(New->getLocation(), diag::err_block_on_nonlocal);
3161  return New;
3162}
3163
3164/// CollectIvarsToConstructOrDestruct - Collect those ivars which require
3165/// initialization.
3166void Sema::CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI,
3167                                SmallVectorImpl<ObjCIvarDecl*> &Ivars) {
3168  for (ObjCIvarDecl *Iv = OI->all_declared_ivar_begin(); Iv;
3169       Iv= Iv->getNextIvar()) {
3170    QualType QT = Context.getBaseElementType(Iv->getType());
3171    if (QT->isRecordType())
3172      Ivars.push_back(Iv);
3173  }
3174}
3175
3176void Sema::DiagnoseUseOfUnimplementedSelectors() {
3177  // Load referenced selectors from the external source.
3178  if (ExternalSource) {
3179    SmallVector<std::pair<Selector, SourceLocation>, 4> Sels;
3180    ExternalSource->ReadReferencedSelectors(Sels);
3181    for (unsigned I = 0, N = Sels.size(); I != N; ++I)
3182      ReferencedSelectors[Sels[I].first] = Sels[I].second;
3183  }
3184
3185  // Warning will be issued only when selector table is
3186  // generated (which means there is at lease one implementation
3187  // in the TU). This is to match gcc's behavior.
3188  if (ReferencedSelectors.empty() ||
3189      !Context.AnyObjCImplementation())
3190    return;
3191  for (llvm::DenseMap<Selector, SourceLocation>::iterator S =
3192        ReferencedSelectors.begin(),
3193       E = ReferencedSelectors.end(); S != E; ++S) {
3194    Selector Sel = (*S).first;
3195    if (!LookupImplementedMethodInGlobalPool(Sel))
3196      Diag((*S).second, diag::warn_unimplemented_selector) << Sel;
3197  }
3198  return;
3199}
3200