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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp | 5061 |
1 files changed, 5061 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp new file mode 100644 index 000000000000..595cc76cd4a3 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaDeclObjC.cpp @@ -0,0 +1,5061 @@ +//===--- SemaDeclObjC.cpp - Semantic Analysis for ObjC Declarations -------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements semantic analysis for Objective C declarations. +// +//===----------------------------------------------------------------------===// + +#include "TypeLocBuilder.h" +#include "clang/AST/ASTConsumer.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTMutationListener.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/Basic/SourceManager.h" +#include "clang/Sema/DeclSpec.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/Scope.h" +#include "clang/Sema/ScopeInfo.h" +#include "clang/Sema/SemaInternal.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/DenseSet.h" + +using namespace clang; + +/// Check whether the given method, which must be in the 'init' +/// family, is a valid member of that family. +/// +/// \param receiverTypeIfCall - if null, check this as if declaring it; +/// if non-null, check this as if making a call to it with the given +/// receiver type +/// +/// \return true to indicate that there was an error and appropriate +/// actions were taken +bool Sema::checkInitMethod(ObjCMethodDecl *method, + QualType receiverTypeIfCall) { + if (method->isInvalidDecl()) return true; + + // This castAs is safe: methods that don't return an object + // pointer won't be inferred as inits and will reject an explicit + // objc_method_family(init). + + // We ignore protocols here. Should we? What about Class? + + const ObjCObjectType *result = + method->getReturnType()->castAs<ObjCObjectPointerType>()->getObjectType(); + + if (result->isObjCId()) { + return false; + } else if (result->isObjCClass()) { + // fall through: always an error + } else { + ObjCInterfaceDecl *resultClass = result->getInterface(); + assert(resultClass && "unexpected object type!"); + + // It's okay for the result type to still be a forward declaration + // if we're checking an interface declaration. + if (!resultClass->hasDefinition()) { + if (receiverTypeIfCall.isNull() && + !isa<ObjCImplementationDecl>(method->getDeclContext())) + return false; + + // Otherwise, we try to compare class types. + } else { + // If this method was declared in a protocol, we can't check + // anything unless we have a receiver type that's an interface. + const ObjCInterfaceDecl *receiverClass = nullptr; + if (isa<ObjCProtocolDecl>(method->getDeclContext())) { + if (receiverTypeIfCall.isNull()) + return false; + + receiverClass = receiverTypeIfCall->castAs<ObjCObjectPointerType>() + ->getInterfaceDecl(); + + // This can be null for calls to e.g. id<Foo>. + if (!receiverClass) return false; + } else { + receiverClass = method->getClassInterface(); + assert(receiverClass && "method not associated with a class!"); + } + + // If either class is a subclass of the other, it's fine. + if (receiverClass->isSuperClassOf(resultClass) || + resultClass->isSuperClassOf(receiverClass)) + return false; + } + } + + SourceLocation loc = method->getLocation(); + + // If we're in a system header, and this is not a call, just make + // the method unusable. + if (receiverTypeIfCall.isNull() && getSourceManager().isInSystemHeader(loc)) { + method->addAttr(UnavailableAttr::CreateImplicit(Context, "", + UnavailableAttr::IR_ARCInitReturnsUnrelated, loc)); + return true; + } + + // Otherwise, it's an error. + Diag(loc, diag::err_arc_init_method_unrelated_result_type); + method->setInvalidDecl(); + return true; +} + +/// Issue a warning if the parameter of the overridden method is non-escaping +/// but the parameter of the overriding method is not. +static bool diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD, + Sema &S) { + if (OldD->hasAttr<NoEscapeAttr>() && !NewD->hasAttr<NoEscapeAttr>()) { + S.Diag(NewD->getLocation(), diag::warn_overriding_method_missing_noescape); + S.Diag(OldD->getLocation(), diag::note_overridden_marked_noescape); + return false; + } + + return true; +} + +/// Produce additional diagnostics if a category conforms to a protocol that +/// defines a method taking a non-escaping parameter. +static void diagnoseNoescape(const ParmVarDecl *NewD, const ParmVarDecl *OldD, + const ObjCCategoryDecl *CD, + const ObjCProtocolDecl *PD, Sema &S) { + if (!diagnoseNoescape(NewD, OldD, S)) + S.Diag(CD->getLocation(), diag::note_cat_conform_to_noescape_prot) + << CD->IsClassExtension() << PD + << cast<ObjCMethodDecl>(NewD->getDeclContext()); +} + +void Sema::CheckObjCMethodOverride(ObjCMethodDecl *NewMethod, + const ObjCMethodDecl *Overridden) { + if (Overridden->hasRelatedResultType() && + !NewMethod->hasRelatedResultType()) { + // This can only happen when the method follows a naming convention that + // implies a related result type, and the original (overridden) method has + // a suitable return type, but the new (overriding) method does not have + // a suitable return type. + QualType ResultType = NewMethod->getReturnType(); + SourceRange ResultTypeRange = NewMethod->getReturnTypeSourceRange(); + + // Figure out which class this method is part of, if any. + ObjCInterfaceDecl *CurrentClass + = dyn_cast<ObjCInterfaceDecl>(NewMethod->getDeclContext()); + if (!CurrentClass) { + DeclContext *DC = NewMethod->getDeclContext(); + if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(DC)) + CurrentClass = Cat->getClassInterface(); + else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(DC)) + CurrentClass = Impl->getClassInterface(); + else if (ObjCCategoryImplDecl *CatImpl + = dyn_cast<ObjCCategoryImplDecl>(DC)) + CurrentClass = CatImpl->getClassInterface(); + } + + if (CurrentClass) { + Diag(NewMethod->getLocation(), + diag::warn_related_result_type_compatibility_class) + << Context.getObjCInterfaceType(CurrentClass) + << ResultType + << ResultTypeRange; + } else { + Diag(NewMethod->getLocation(), + diag::warn_related_result_type_compatibility_protocol) + << ResultType + << ResultTypeRange; + } + + if (ObjCMethodFamily Family = Overridden->getMethodFamily()) + Diag(Overridden->getLocation(), + diag::note_related_result_type_family) + << /*overridden method*/ 0 + << Family; + else + Diag(Overridden->getLocation(), + diag::note_related_result_type_overridden); + } + + if ((NewMethod->hasAttr<NSReturnsRetainedAttr>() != + Overridden->hasAttr<NSReturnsRetainedAttr>())) { + Diag(NewMethod->getLocation(), + getLangOpts().ObjCAutoRefCount + ? diag::err_nsreturns_retained_attribute_mismatch + : diag::warn_nsreturns_retained_attribute_mismatch) + << 1; + Diag(Overridden->getLocation(), diag::note_previous_decl) << "method"; + } + if ((NewMethod->hasAttr<NSReturnsNotRetainedAttr>() != + Overridden->hasAttr<NSReturnsNotRetainedAttr>())) { + Diag(NewMethod->getLocation(), + getLangOpts().ObjCAutoRefCount + ? diag::err_nsreturns_retained_attribute_mismatch + : diag::warn_nsreturns_retained_attribute_mismatch) + << 0; + Diag(Overridden->getLocation(), diag::note_previous_decl) << "method"; + } + + ObjCMethodDecl::param_const_iterator oi = Overridden->param_begin(), + oe = Overridden->param_end(); + for (ObjCMethodDecl::param_iterator ni = NewMethod->param_begin(), + ne = NewMethod->param_end(); + ni != ne && oi != oe; ++ni, ++oi) { + const ParmVarDecl *oldDecl = (*oi); + ParmVarDecl *newDecl = (*ni); + if (newDecl->hasAttr<NSConsumedAttr>() != + oldDecl->hasAttr<NSConsumedAttr>()) { + Diag(newDecl->getLocation(), + getLangOpts().ObjCAutoRefCount + ? diag::err_nsconsumed_attribute_mismatch + : diag::warn_nsconsumed_attribute_mismatch); + Diag(oldDecl->getLocation(), diag::note_previous_decl) << "parameter"; + } + + diagnoseNoescape(newDecl, oldDecl, *this); + } +} + +/// Check a method declaration for compatibility with the Objective-C +/// ARC conventions. +bool Sema::CheckARCMethodDecl(ObjCMethodDecl *method) { + ObjCMethodFamily family = method->getMethodFamily(); + switch (family) { + case OMF_None: + case OMF_finalize: + case OMF_retain: + case OMF_release: + case OMF_autorelease: + case OMF_retainCount: + case OMF_self: + case OMF_initialize: + case OMF_performSelector: + return false; + + case OMF_dealloc: + if (!Context.hasSameType(method->getReturnType(), Context.VoidTy)) { + SourceRange ResultTypeRange = method->getReturnTypeSourceRange(); + if (ResultTypeRange.isInvalid()) + Diag(method->getLocation(), diag::err_dealloc_bad_result_type) + << method->getReturnType() + << FixItHint::CreateInsertion(method->getSelectorLoc(0), "(void)"); + else + Diag(method->getLocation(), diag::err_dealloc_bad_result_type) + << method->getReturnType() + << FixItHint::CreateReplacement(ResultTypeRange, "void"); + return true; + } + return false; + + case OMF_init: + // If the method doesn't obey the init rules, don't bother annotating it. + if (checkInitMethod(method, QualType())) + return true; + + method->addAttr(NSConsumesSelfAttr::CreateImplicit(Context)); + + // Don't add a second copy of this attribute, but otherwise don't + // let it be suppressed. + if (method->hasAttr<NSReturnsRetainedAttr>()) + return false; + break; + + case OMF_alloc: + case OMF_copy: + case OMF_mutableCopy: + case OMF_new: + if (method->hasAttr<NSReturnsRetainedAttr>() || + method->hasAttr<NSReturnsNotRetainedAttr>() || + method->hasAttr<NSReturnsAutoreleasedAttr>()) + return false; + break; + } + + method->addAttr(NSReturnsRetainedAttr::CreateImplicit(Context)); + return false; +} + +static void DiagnoseObjCImplementedDeprecations(Sema &S, const NamedDecl *ND, + SourceLocation ImplLoc) { + if (!ND) + return; + bool IsCategory = false; + StringRef RealizedPlatform; + AvailabilityResult Availability = ND->getAvailability( + /*Message=*/nullptr, /*EnclosingVersion=*/VersionTuple(), + &RealizedPlatform); + if (Availability != AR_Deprecated) { + if (isa<ObjCMethodDecl>(ND)) { + if (Availability != AR_Unavailable) + return; + if (RealizedPlatform.empty()) + RealizedPlatform = S.Context.getTargetInfo().getPlatformName(); + // Warn about implementing unavailable methods, unless the unavailable + // is for an app extension. + if (RealizedPlatform.endswith("_app_extension")) + return; + S.Diag(ImplLoc, diag::warn_unavailable_def); + S.Diag(ND->getLocation(), diag::note_method_declared_at) + << ND->getDeclName(); + return; + } + if (const auto *CD = dyn_cast<ObjCCategoryDecl>(ND)) { + if (!CD->getClassInterface()->isDeprecated()) + return; + ND = CD->getClassInterface(); + IsCategory = true; + } else + return; + } + S.Diag(ImplLoc, diag::warn_deprecated_def) + << (isa<ObjCMethodDecl>(ND) + ? /*Method*/ 0 + : isa<ObjCCategoryDecl>(ND) || IsCategory ? /*Category*/ 2 + : /*Class*/ 1); + if (isa<ObjCMethodDecl>(ND)) + S.Diag(ND->getLocation(), diag::note_method_declared_at) + << ND->getDeclName(); + else + S.Diag(ND->getLocation(), diag::note_previous_decl) + << (isa<ObjCCategoryDecl>(ND) ? "category" : "class"); +} + +/// AddAnyMethodToGlobalPool - Add any method, instance or factory to global +/// pool. +void Sema::AddAnyMethodToGlobalPool(Decl *D) { + ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D); + + // If we don't have a valid method decl, simply return. + if (!MDecl) + return; + if (MDecl->isInstanceMethod()) + AddInstanceMethodToGlobalPool(MDecl, true); + else + AddFactoryMethodToGlobalPool(MDecl, true); +} + +/// HasExplicitOwnershipAttr - returns true when pointer to ObjC pointer +/// has explicit ownership attribute; false otherwise. +static bool +HasExplicitOwnershipAttr(Sema &S, ParmVarDecl *Param) { + QualType T = Param->getType(); + + if (const PointerType *PT = T->getAs<PointerType>()) { + T = PT->getPointeeType(); + } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) { + T = RT->getPointeeType(); + } else { + return true; + } + + // If we have a lifetime qualifier, but it's local, we must have + // inferred it. So, it is implicit. + return !T.getLocalQualifiers().hasObjCLifetime(); +} + +/// ActOnStartOfObjCMethodDef - This routine sets up parameters; invisible +/// and user declared, in the method definition's AST. +void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, Decl *D) { + assert((getCurMethodDecl() == nullptr) && "Methodparsing confused"); + ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D); + + // If we don't have a valid method decl, simply return. + if (!MDecl) + return; + + QualType ResultType = MDecl->getReturnType(); + if (!ResultType->isDependentType() && !ResultType->isVoidType() && + !MDecl->isInvalidDecl() && + RequireCompleteType(MDecl->getLocation(), ResultType, + diag::err_func_def_incomplete_result)) + MDecl->setInvalidDecl(); + + // Allow all of Sema to see that we are entering a method definition. + PushDeclContext(FnBodyScope, MDecl); + PushFunctionScope(); + + // Create Decl objects for each parameter, entrring them in the scope for + // binding to their use. + + // Insert the invisible arguments, self and _cmd! + MDecl->createImplicitParams(Context, MDecl->getClassInterface()); + + PushOnScopeChains(MDecl->getSelfDecl(), FnBodyScope); + PushOnScopeChains(MDecl->getCmdDecl(), FnBodyScope); + + // The ObjC parser requires parameter names so there's no need to check. + CheckParmsForFunctionDef(MDecl->parameters(), + /*CheckParameterNames=*/false); + + // Introduce all of the other parameters into this scope. + for (auto *Param : MDecl->parameters()) { + if (!Param->isInvalidDecl() && + getLangOpts().ObjCAutoRefCount && + !HasExplicitOwnershipAttr(*this, Param)) + Diag(Param->getLocation(), diag::warn_arc_strong_pointer_objc_pointer) << + Param->getType(); + + if (Param->getIdentifier()) + PushOnScopeChains(Param, FnBodyScope); + } + + // In ARC, disallow definition of retain/release/autorelease/retainCount + if (getLangOpts().ObjCAutoRefCount) { + switch (MDecl->getMethodFamily()) { + case OMF_retain: + case OMF_retainCount: + case OMF_release: + case OMF_autorelease: + Diag(MDecl->getLocation(), diag::err_arc_illegal_method_def) + << 0 << MDecl->getSelector(); + break; + + case OMF_None: + case OMF_dealloc: + case OMF_finalize: + case OMF_alloc: + case OMF_init: + case OMF_mutableCopy: + case OMF_copy: + case OMF_new: + case OMF_self: + case OMF_initialize: + case OMF_performSelector: + break; + } + } + + // Warn on deprecated methods under -Wdeprecated-implementations, + // and prepare for warning on missing super calls. + if (ObjCInterfaceDecl *IC = MDecl->getClassInterface()) { + ObjCMethodDecl *IMD = + IC->lookupMethod(MDecl->getSelector(), MDecl->isInstanceMethod()); + + if (IMD) { + ObjCImplDecl *ImplDeclOfMethodDef = + dyn_cast<ObjCImplDecl>(MDecl->getDeclContext()); + ObjCContainerDecl *ContDeclOfMethodDecl = + dyn_cast<ObjCContainerDecl>(IMD->getDeclContext()); + ObjCImplDecl *ImplDeclOfMethodDecl = nullptr; + if (ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(ContDeclOfMethodDecl)) + ImplDeclOfMethodDecl = OID->getImplementation(); + else if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContDeclOfMethodDecl)) { + if (CD->IsClassExtension()) { + if (ObjCInterfaceDecl *OID = CD->getClassInterface()) + ImplDeclOfMethodDecl = OID->getImplementation(); + } else + ImplDeclOfMethodDecl = CD->getImplementation(); + } + // No need to issue deprecated warning if deprecated mehod in class/category + // is being implemented in its own implementation (no overriding is involved). + if (!ImplDeclOfMethodDecl || ImplDeclOfMethodDecl != ImplDeclOfMethodDef) + DiagnoseObjCImplementedDeprecations(*this, IMD, MDecl->getLocation()); + } + + if (MDecl->getMethodFamily() == OMF_init) { + if (MDecl->isDesignatedInitializerForTheInterface()) { + getCurFunction()->ObjCIsDesignatedInit = true; + getCurFunction()->ObjCWarnForNoDesignatedInitChain = + IC->getSuperClass() != nullptr; + } else if (IC->hasDesignatedInitializers()) { + getCurFunction()->ObjCIsSecondaryInit = true; + getCurFunction()->ObjCWarnForNoInitDelegation = true; + } + } + + // If this is "dealloc" or "finalize", set some bit here. + // Then in ActOnSuperMessage() (SemaExprObjC), set it back to false. + // Finally, in ActOnFinishFunctionBody() (SemaDecl), warn if flag is set. + // Only do this if the current class actually has a superclass. + if (const ObjCInterfaceDecl *SuperClass = IC->getSuperClass()) { + ObjCMethodFamily Family = MDecl->getMethodFamily(); + if (Family == OMF_dealloc) { + if (!(getLangOpts().ObjCAutoRefCount || + getLangOpts().getGC() == LangOptions::GCOnly)) + getCurFunction()->ObjCShouldCallSuper = true; + + } else if (Family == OMF_finalize) { + if (Context.getLangOpts().getGC() != LangOptions::NonGC) + getCurFunction()->ObjCShouldCallSuper = true; + + } else { + const ObjCMethodDecl *SuperMethod = + SuperClass->lookupMethod(MDecl->getSelector(), + MDecl->isInstanceMethod()); + getCurFunction()->ObjCShouldCallSuper = + (SuperMethod && SuperMethod->hasAttr<ObjCRequiresSuperAttr>()); + } + } + } +} + +namespace { + +// Callback to only accept typo corrections that are Objective-C classes. +// If an ObjCInterfaceDecl* is given to the constructor, then the validation +// function will reject corrections to that class. +class ObjCInterfaceValidatorCCC : public CorrectionCandidateCallback { + public: + ObjCInterfaceValidatorCCC() : CurrentIDecl(nullptr) {} + explicit ObjCInterfaceValidatorCCC(ObjCInterfaceDecl *IDecl) + : CurrentIDecl(IDecl) {} + + bool ValidateCandidate(const TypoCorrection &candidate) override { + ObjCInterfaceDecl *ID = candidate.getCorrectionDeclAs<ObjCInterfaceDecl>(); + return ID && !declaresSameEntity(ID, CurrentIDecl); + } + + private: + ObjCInterfaceDecl *CurrentIDecl; +}; + +} // end anonymous namespace + +static void diagnoseUseOfProtocols(Sema &TheSema, + ObjCContainerDecl *CD, + ObjCProtocolDecl *const *ProtoRefs, + unsigned NumProtoRefs, + const SourceLocation *ProtoLocs) { + assert(ProtoRefs); + // Diagnose availability in the context of the ObjC container. + Sema::ContextRAII SavedContext(TheSema, CD); + for (unsigned i = 0; i < NumProtoRefs; ++i) { + (void)TheSema.DiagnoseUseOfDecl(ProtoRefs[i], ProtoLocs[i], + /*UnknownObjCClass=*/nullptr, + /*ObjCPropertyAccess=*/false, + /*AvoidPartialAvailabilityChecks=*/true); + } +} + +void Sema:: +ActOnSuperClassOfClassInterface(Scope *S, + SourceLocation AtInterfaceLoc, + ObjCInterfaceDecl *IDecl, + IdentifierInfo *ClassName, + SourceLocation ClassLoc, + IdentifierInfo *SuperName, + SourceLocation SuperLoc, + ArrayRef<ParsedType> SuperTypeArgs, + SourceRange SuperTypeArgsRange) { + // Check if a different kind of symbol declared in this scope. + NamedDecl *PrevDecl = LookupSingleName(TUScope, SuperName, SuperLoc, + LookupOrdinaryName); + + if (!PrevDecl) { + // Try to correct for a typo in the superclass name without correcting + // to the class we're defining. + if (TypoCorrection Corrected = CorrectTypo( + DeclarationNameInfo(SuperName, SuperLoc), + LookupOrdinaryName, TUScope, + nullptr, llvm::make_unique<ObjCInterfaceValidatorCCC>(IDecl), + CTK_ErrorRecovery)) { + diagnoseTypo(Corrected, PDiag(diag::err_undef_superclass_suggest) + << SuperName << ClassName); + PrevDecl = Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>(); + } + } + + if (declaresSameEntity(PrevDecl, IDecl)) { + Diag(SuperLoc, diag::err_recursive_superclass) + << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc); + IDecl->setEndOfDefinitionLoc(ClassLoc); + } else { + ObjCInterfaceDecl *SuperClassDecl = + dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl); + QualType SuperClassType; + + // Diagnose classes that inherit from deprecated classes. + if (SuperClassDecl) { + (void)DiagnoseUseOfDecl(SuperClassDecl, SuperLoc); + SuperClassType = Context.getObjCInterfaceType(SuperClassDecl); + } + + if (PrevDecl && !SuperClassDecl) { + // The previous declaration was not a class decl. Check if we have a + // typedef. If we do, get the underlying class type. + if (const TypedefNameDecl *TDecl = + dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) { + QualType T = TDecl->getUnderlyingType(); + if (T->isObjCObjectType()) { + if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface()) { + SuperClassDecl = dyn_cast<ObjCInterfaceDecl>(IDecl); + SuperClassType = Context.getTypeDeclType(TDecl); + + // This handles the following case: + // @interface NewI @end + // typedef NewI DeprI __attribute__((deprecated("blah"))) + // @interface SI : DeprI /* warn here */ @end + (void)DiagnoseUseOfDecl(const_cast<TypedefNameDecl*>(TDecl), SuperLoc); + } + } + } + + // This handles the following case: + // + // typedef int SuperClass; + // @interface MyClass : SuperClass {} @end + // + if (!SuperClassDecl) { + Diag(SuperLoc, diag::err_redefinition_different_kind) << SuperName; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + } + } + + if (!dyn_cast_or_null<TypedefNameDecl>(PrevDecl)) { + if (!SuperClassDecl) + Diag(SuperLoc, diag::err_undef_superclass) + << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc); + else if (RequireCompleteType(SuperLoc, + SuperClassType, + diag::err_forward_superclass, + SuperClassDecl->getDeclName(), + ClassName, + SourceRange(AtInterfaceLoc, ClassLoc))) { + SuperClassDecl = nullptr; + SuperClassType = QualType(); + } + } + + if (SuperClassType.isNull()) { + assert(!SuperClassDecl && "Failed to set SuperClassType?"); + return; + } + + // Handle type arguments on the superclass. + TypeSourceInfo *SuperClassTInfo = nullptr; + if (!SuperTypeArgs.empty()) { + TypeResult fullSuperClassType = actOnObjCTypeArgsAndProtocolQualifiers( + S, + SuperLoc, + CreateParsedType(SuperClassType, + nullptr), + SuperTypeArgsRange.getBegin(), + SuperTypeArgs, + SuperTypeArgsRange.getEnd(), + SourceLocation(), + { }, + { }, + SourceLocation()); + if (!fullSuperClassType.isUsable()) + return; + + SuperClassType = GetTypeFromParser(fullSuperClassType.get(), + &SuperClassTInfo); + } + + if (!SuperClassTInfo) { + SuperClassTInfo = Context.getTrivialTypeSourceInfo(SuperClassType, + SuperLoc); + } + + IDecl->setSuperClass(SuperClassTInfo); + IDecl->setEndOfDefinitionLoc(SuperClassTInfo->getTypeLoc().getLocEnd()); + } +} + +DeclResult Sema::actOnObjCTypeParam(Scope *S, + ObjCTypeParamVariance variance, + SourceLocation varianceLoc, + unsigned index, + IdentifierInfo *paramName, + SourceLocation paramLoc, + SourceLocation colonLoc, + ParsedType parsedTypeBound) { + // If there was an explicitly-provided type bound, check it. + TypeSourceInfo *typeBoundInfo = nullptr; + if (parsedTypeBound) { + // The type bound can be any Objective-C pointer type. + QualType typeBound = GetTypeFromParser(parsedTypeBound, &typeBoundInfo); + if (typeBound->isObjCObjectPointerType()) { + // okay + } else if (typeBound->isObjCObjectType()) { + // The user forgot the * on an Objective-C pointer type, e.g., + // "T : NSView". + SourceLocation starLoc = getLocForEndOfToken( + typeBoundInfo->getTypeLoc().getEndLoc()); + Diag(typeBoundInfo->getTypeLoc().getBeginLoc(), + diag::err_objc_type_param_bound_missing_pointer) + << typeBound << paramName + << FixItHint::CreateInsertion(starLoc, " *"); + + // Create a new type location builder so we can update the type + // location information we have. + TypeLocBuilder builder; + builder.pushFullCopy(typeBoundInfo->getTypeLoc()); + + // Create the Objective-C pointer type. + typeBound = Context.getObjCObjectPointerType(typeBound); + ObjCObjectPointerTypeLoc newT + = builder.push<ObjCObjectPointerTypeLoc>(typeBound); + newT.setStarLoc(starLoc); + + // Form the new type source information. + typeBoundInfo = builder.getTypeSourceInfo(Context, typeBound); + } else { + // Not a valid type bound. + Diag(typeBoundInfo->getTypeLoc().getBeginLoc(), + diag::err_objc_type_param_bound_nonobject) + << typeBound << paramName; + + // Forget the bound; we'll default to id later. + typeBoundInfo = nullptr; + } + + // Type bounds cannot have qualifiers (even indirectly) or explicit + // nullability. + if (typeBoundInfo) { + QualType typeBound = typeBoundInfo->getType(); + TypeLoc qual = typeBoundInfo->getTypeLoc().findExplicitQualifierLoc(); + if (qual || typeBound.hasQualifiers()) { + bool diagnosed = false; + SourceRange rangeToRemove; + if (qual) { + if (auto attr = qual.getAs<AttributedTypeLoc>()) { + rangeToRemove = attr.getLocalSourceRange(); + if (attr.getTypePtr()->getImmediateNullability()) { + Diag(attr.getLocStart(), + diag::err_objc_type_param_bound_explicit_nullability) + << paramName << typeBound + << FixItHint::CreateRemoval(rangeToRemove); + diagnosed = true; + } + } + } + + if (!diagnosed) { + Diag(qual ? qual.getLocStart() + : typeBoundInfo->getTypeLoc().getLocStart(), + diag::err_objc_type_param_bound_qualified) + << paramName << typeBound << typeBound.getQualifiers().getAsString() + << FixItHint::CreateRemoval(rangeToRemove); + } + + // If the type bound has qualifiers other than CVR, we need to strip + // them or we'll probably assert later when trying to apply new + // qualifiers. + Qualifiers quals = typeBound.getQualifiers(); + quals.removeCVRQualifiers(); + if (!quals.empty()) { + typeBoundInfo = + Context.getTrivialTypeSourceInfo(typeBound.getUnqualifiedType()); + } + } + } + } + + // If there was no explicit type bound (or we removed it due to an error), + // use 'id' instead. + if (!typeBoundInfo) { + colonLoc = SourceLocation(); + typeBoundInfo = Context.getTrivialTypeSourceInfo(Context.getObjCIdType()); + } + + // Create the type parameter. + return ObjCTypeParamDecl::Create(Context, CurContext, variance, varianceLoc, + index, paramLoc, paramName, colonLoc, + typeBoundInfo); +} + +ObjCTypeParamList *Sema::actOnObjCTypeParamList(Scope *S, + SourceLocation lAngleLoc, + ArrayRef<Decl *> typeParamsIn, + SourceLocation rAngleLoc) { + // We know that the array only contains Objective-C type parameters. + ArrayRef<ObjCTypeParamDecl *> + typeParams( + reinterpret_cast<ObjCTypeParamDecl * const *>(typeParamsIn.data()), + typeParamsIn.size()); + + // Diagnose redeclarations of type parameters. + // We do this now because Objective-C type parameters aren't pushed into + // scope until later (after the instance variable block), but we want the + // diagnostics to occur right after we parse the type parameter list. + llvm::SmallDenseMap<IdentifierInfo *, ObjCTypeParamDecl *> knownParams; + for (auto typeParam : typeParams) { + auto known = knownParams.find(typeParam->getIdentifier()); + if (known != knownParams.end()) { + Diag(typeParam->getLocation(), diag::err_objc_type_param_redecl) + << typeParam->getIdentifier() + << SourceRange(known->second->getLocation()); + + typeParam->setInvalidDecl(); + } else { + knownParams.insert(std::make_pair(typeParam->getIdentifier(), typeParam)); + + // Push the type parameter into scope. + PushOnScopeChains(typeParam, S, /*AddToContext=*/false); + } + } + + // Create the parameter list. + return ObjCTypeParamList::create(Context, lAngleLoc, typeParams, rAngleLoc); +} + +void Sema::popObjCTypeParamList(Scope *S, ObjCTypeParamList *typeParamList) { + for (auto typeParam : *typeParamList) { + if (!typeParam->isInvalidDecl()) { + S->RemoveDecl(typeParam); + IdResolver.RemoveDecl(typeParam); + } + } +} + +namespace { + /// The context in which an Objective-C type parameter list occurs, for use + /// in diagnostics. + enum class TypeParamListContext { + ForwardDeclaration, + Definition, + Category, + Extension + }; +} // end anonymous namespace + +/// Check consistency between two Objective-C type parameter lists, e.g., +/// between a category/extension and an \@interface or between an \@class and an +/// \@interface. +static bool checkTypeParamListConsistency(Sema &S, + ObjCTypeParamList *prevTypeParams, + ObjCTypeParamList *newTypeParams, + TypeParamListContext newContext) { + // If the sizes don't match, complain about that. + if (prevTypeParams->size() != newTypeParams->size()) { + SourceLocation diagLoc; + if (newTypeParams->size() > prevTypeParams->size()) { + diagLoc = newTypeParams->begin()[prevTypeParams->size()]->getLocation(); + } else { + diagLoc = S.getLocForEndOfToken(newTypeParams->back()->getLocEnd()); + } + + S.Diag(diagLoc, diag::err_objc_type_param_arity_mismatch) + << static_cast<unsigned>(newContext) + << (newTypeParams->size() > prevTypeParams->size()) + << prevTypeParams->size() + << newTypeParams->size(); + + return true; + } + + // Match up the type parameters. + for (unsigned i = 0, n = prevTypeParams->size(); i != n; ++i) { + ObjCTypeParamDecl *prevTypeParam = prevTypeParams->begin()[i]; + ObjCTypeParamDecl *newTypeParam = newTypeParams->begin()[i]; + + // Check for consistency of the variance. + if (newTypeParam->getVariance() != prevTypeParam->getVariance()) { + if (newTypeParam->getVariance() == ObjCTypeParamVariance::Invariant && + newContext != TypeParamListContext::Definition) { + // When the new type parameter is invariant and is not part + // of the definition, just propagate the variance. + newTypeParam->setVariance(prevTypeParam->getVariance()); + } else if (prevTypeParam->getVariance() + == ObjCTypeParamVariance::Invariant && + !(isa<ObjCInterfaceDecl>(prevTypeParam->getDeclContext()) && + cast<ObjCInterfaceDecl>(prevTypeParam->getDeclContext()) + ->getDefinition() == prevTypeParam->getDeclContext())) { + // When the old parameter is invariant and was not part of the + // definition, just ignore the difference because it doesn't + // matter. + } else { + { + // Diagnose the conflict and update the second declaration. + SourceLocation diagLoc = newTypeParam->getVarianceLoc(); + if (diagLoc.isInvalid()) + diagLoc = newTypeParam->getLocStart(); + + auto diag = S.Diag(diagLoc, + diag::err_objc_type_param_variance_conflict) + << static_cast<unsigned>(newTypeParam->getVariance()) + << newTypeParam->getDeclName() + << static_cast<unsigned>(prevTypeParam->getVariance()) + << prevTypeParam->getDeclName(); + switch (prevTypeParam->getVariance()) { + case ObjCTypeParamVariance::Invariant: + diag << FixItHint::CreateRemoval(newTypeParam->getVarianceLoc()); + break; + + case ObjCTypeParamVariance::Covariant: + case ObjCTypeParamVariance::Contravariant: { + StringRef newVarianceStr + = prevTypeParam->getVariance() == ObjCTypeParamVariance::Covariant + ? "__covariant" + : "__contravariant"; + if (newTypeParam->getVariance() + == ObjCTypeParamVariance::Invariant) { + diag << FixItHint::CreateInsertion(newTypeParam->getLocStart(), + (newVarianceStr + " ").str()); + } else { + diag << FixItHint::CreateReplacement(newTypeParam->getVarianceLoc(), + newVarianceStr); + } + } + } + } + + S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here) + << prevTypeParam->getDeclName(); + + // Override the variance. + newTypeParam->setVariance(prevTypeParam->getVariance()); + } + } + + // If the bound types match, there's nothing to do. + if (S.Context.hasSameType(prevTypeParam->getUnderlyingType(), + newTypeParam->getUnderlyingType())) + continue; + + // If the new type parameter's bound was explicit, complain about it being + // different from the original. + if (newTypeParam->hasExplicitBound()) { + SourceRange newBoundRange = newTypeParam->getTypeSourceInfo() + ->getTypeLoc().getSourceRange(); + S.Diag(newBoundRange.getBegin(), diag::err_objc_type_param_bound_conflict) + << newTypeParam->getUnderlyingType() + << newTypeParam->getDeclName() + << prevTypeParam->hasExplicitBound() + << prevTypeParam->getUnderlyingType() + << (newTypeParam->getDeclName() == prevTypeParam->getDeclName()) + << prevTypeParam->getDeclName() + << FixItHint::CreateReplacement( + newBoundRange, + prevTypeParam->getUnderlyingType().getAsString( + S.Context.getPrintingPolicy())); + + S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here) + << prevTypeParam->getDeclName(); + + // Override the new type parameter's bound type with the previous type, + // so that it's consistent. + newTypeParam->setTypeSourceInfo( + S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType())); + continue; + } + + // The new type parameter got the implicit bound of 'id'. That's okay for + // categories and extensions (overwrite it later), but not for forward + // declarations and @interfaces, because those must be standalone. + if (newContext == TypeParamListContext::ForwardDeclaration || + newContext == TypeParamListContext::Definition) { + // Diagnose this problem for forward declarations and definitions. + SourceLocation insertionLoc + = S.getLocForEndOfToken(newTypeParam->getLocation()); + std::string newCode + = " : " + prevTypeParam->getUnderlyingType().getAsString( + S.Context.getPrintingPolicy()); + S.Diag(newTypeParam->getLocation(), + diag::err_objc_type_param_bound_missing) + << prevTypeParam->getUnderlyingType() + << newTypeParam->getDeclName() + << (newContext == TypeParamListContext::ForwardDeclaration) + << FixItHint::CreateInsertion(insertionLoc, newCode); + + S.Diag(prevTypeParam->getLocation(), diag::note_objc_type_param_here) + << prevTypeParam->getDeclName(); + } + + // Update the new type parameter's bound to match the previous one. + newTypeParam->setTypeSourceInfo( + S.Context.getTrivialTypeSourceInfo(prevTypeParam->getUnderlyingType())); + } + + return false; +} + +Decl *Sema::ActOnStartClassInterface( + Scope *S, SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName, + SourceLocation ClassLoc, ObjCTypeParamList *typeParamList, + IdentifierInfo *SuperName, SourceLocation SuperLoc, + ArrayRef<ParsedType> SuperTypeArgs, SourceRange SuperTypeArgsRange, + Decl *const *ProtoRefs, unsigned NumProtoRefs, + const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc, + const ParsedAttributesView &AttrList) { + assert(ClassName && "Missing class identifier"); + + // Check for another declaration kind with the same name. + NamedDecl *PrevDecl = + LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName, + forRedeclarationInCurContext()); + + if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) { + Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + } + + // Create a declaration to describe this @interface. + ObjCInterfaceDecl* PrevIDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl); + + if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) { + // A previous decl with a different name is because of + // @compatibility_alias, for example: + // \code + // @class NewImage; + // @compatibility_alias OldImage NewImage; + // \endcode + // A lookup for 'OldImage' will return the 'NewImage' decl. + // + // In such a case use the real declaration name, instead of the alias one, + // otherwise we will break IdentifierResolver and redecls-chain invariants. + // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl + // has been aliased. + ClassName = PrevIDecl->getIdentifier(); + } + + // If there was a forward declaration with type parameters, check + // for consistency. + if (PrevIDecl) { + if (ObjCTypeParamList *prevTypeParamList = PrevIDecl->getTypeParamList()) { + if (typeParamList) { + // Both have type parameter lists; check for consistency. + if (checkTypeParamListConsistency(*this, prevTypeParamList, + typeParamList, + TypeParamListContext::Definition)) { + typeParamList = nullptr; + } + } else { + Diag(ClassLoc, diag::err_objc_parameterized_forward_class_first) + << ClassName; + Diag(prevTypeParamList->getLAngleLoc(), diag::note_previous_decl) + << ClassName; + + // Clone the type parameter list. + SmallVector<ObjCTypeParamDecl *, 4> clonedTypeParams; + for (auto typeParam : *prevTypeParamList) { + clonedTypeParams.push_back( + ObjCTypeParamDecl::Create( + Context, + CurContext, + typeParam->getVariance(), + SourceLocation(), + typeParam->getIndex(), + SourceLocation(), + typeParam->getIdentifier(), + SourceLocation(), + Context.getTrivialTypeSourceInfo(typeParam->getUnderlyingType()))); + } + + typeParamList = ObjCTypeParamList::create(Context, + SourceLocation(), + clonedTypeParams, + SourceLocation()); + } + } + } + + ObjCInterfaceDecl *IDecl + = ObjCInterfaceDecl::Create(Context, CurContext, AtInterfaceLoc, ClassName, + typeParamList, PrevIDecl, ClassLoc); + if (PrevIDecl) { + // Class already seen. Was it a definition? + if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) { + Diag(AtInterfaceLoc, diag::err_duplicate_class_def) + << PrevIDecl->getDeclName(); + Diag(Def->getLocation(), diag::note_previous_definition); + IDecl->setInvalidDecl(); + } + } + + ProcessDeclAttributeList(TUScope, IDecl, AttrList); + AddPragmaAttributes(TUScope, IDecl); + PushOnScopeChains(IDecl, TUScope); + + // Start the definition of this class. If we're in a redefinition case, there + // may already be a definition, so we'll end up adding to it. + if (!IDecl->hasDefinition()) + IDecl->startDefinition(); + + if (SuperName) { + // Diagnose availability in the context of the @interface. + ContextRAII SavedContext(*this, IDecl); + + ActOnSuperClassOfClassInterface(S, AtInterfaceLoc, IDecl, + ClassName, ClassLoc, + SuperName, SuperLoc, SuperTypeArgs, + SuperTypeArgsRange); + } else { // we have a root class. + IDecl->setEndOfDefinitionLoc(ClassLoc); + } + + // Check then save referenced protocols. + if (NumProtoRefs) { + diagnoseUseOfProtocols(*this, IDecl, (ObjCProtocolDecl*const*)ProtoRefs, + NumProtoRefs, ProtoLocs); + IDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs, + ProtoLocs, Context); + IDecl->setEndOfDefinitionLoc(EndProtoLoc); + } + + CheckObjCDeclScope(IDecl); + return ActOnObjCContainerStartDefinition(IDecl); +} + +/// ActOnTypedefedProtocols - this action finds protocol list as part of the +/// typedef'ed use for a qualified super class and adds them to the list +/// of the protocols. +void Sema::ActOnTypedefedProtocols(SmallVectorImpl<Decl *> &ProtocolRefs, + SmallVectorImpl<SourceLocation> &ProtocolLocs, + IdentifierInfo *SuperName, + SourceLocation SuperLoc) { + if (!SuperName) + return; + NamedDecl* IDecl = LookupSingleName(TUScope, SuperName, SuperLoc, + LookupOrdinaryName); + if (!IDecl) + return; + + if (const TypedefNameDecl *TDecl = dyn_cast_or_null<TypedefNameDecl>(IDecl)) { + QualType T = TDecl->getUnderlyingType(); + if (T->isObjCObjectType()) + if (const ObjCObjectType *OPT = T->getAs<ObjCObjectType>()) { + ProtocolRefs.append(OPT->qual_begin(), OPT->qual_end()); + // FIXME: Consider whether this should be an invalid loc since the loc + // is not actually pointing to a protocol name reference but to the + // typedef reference. Note that the base class name loc is also pointing + // at the typedef. + ProtocolLocs.append(OPT->getNumProtocols(), SuperLoc); + } + } +} + +/// ActOnCompatibilityAlias - this action is called after complete parsing of +/// a \@compatibility_alias declaration. It sets up the alias relationships. +Decl *Sema::ActOnCompatibilityAlias(SourceLocation AtLoc, + IdentifierInfo *AliasName, + SourceLocation AliasLocation, + IdentifierInfo *ClassName, + SourceLocation ClassLocation) { + // Look for previous declaration of alias name + NamedDecl *ADecl = + LookupSingleName(TUScope, AliasName, AliasLocation, LookupOrdinaryName, + forRedeclarationInCurContext()); + if (ADecl) { + Diag(AliasLocation, diag::err_conflicting_aliasing_type) << AliasName; + Diag(ADecl->getLocation(), diag::note_previous_declaration); + return nullptr; + } + // Check for class declaration + NamedDecl *CDeclU = + LookupSingleName(TUScope, ClassName, ClassLocation, LookupOrdinaryName, + forRedeclarationInCurContext()); + if (const TypedefNameDecl *TDecl = + dyn_cast_or_null<TypedefNameDecl>(CDeclU)) { + QualType T = TDecl->getUnderlyingType(); + if (T->isObjCObjectType()) { + if (NamedDecl *IDecl = T->getAs<ObjCObjectType>()->getInterface()) { + ClassName = IDecl->getIdentifier(); + CDeclU = LookupSingleName(TUScope, ClassName, ClassLocation, + LookupOrdinaryName, + forRedeclarationInCurContext()); + } + } + } + ObjCInterfaceDecl *CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(CDeclU); + if (!CDecl) { + Diag(ClassLocation, diag::warn_undef_interface) << ClassName; + if (CDeclU) + Diag(CDeclU->getLocation(), diag::note_previous_declaration); + return nullptr; + } + + // Everything checked out, instantiate a new alias declaration AST. + ObjCCompatibleAliasDecl *AliasDecl = + ObjCCompatibleAliasDecl::Create(Context, CurContext, AtLoc, AliasName, CDecl); + + if (!CheckObjCDeclScope(AliasDecl)) + PushOnScopeChains(AliasDecl, TUScope); + + return AliasDecl; +} + +bool Sema::CheckForwardProtocolDeclarationForCircularDependency( + IdentifierInfo *PName, + SourceLocation &Ploc, SourceLocation PrevLoc, + const ObjCList<ObjCProtocolDecl> &PList) { + + bool res = false; + for (ObjCList<ObjCProtocolDecl>::iterator I = PList.begin(), + E = PList.end(); I != E; ++I) { + if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier(), + Ploc)) { + if (PDecl->getIdentifier() == PName) { + Diag(Ploc, diag::err_protocol_has_circular_dependency); + Diag(PrevLoc, diag::note_previous_definition); + res = true; + } + + if (!PDecl->hasDefinition()) + continue; + + if (CheckForwardProtocolDeclarationForCircularDependency(PName, Ploc, + PDecl->getLocation(), PDecl->getReferencedProtocols())) + res = true; + } + } + return res; +} + +Decl *Sema::ActOnStartProtocolInterface( + SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName, + SourceLocation ProtocolLoc, Decl *const *ProtoRefs, unsigned NumProtoRefs, + const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc, + const ParsedAttributesView &AttrList) { + bool err = false; + // FIXME: Deal with AttrList. + assert(ProtocolName && "Missing protocol identifier"); + ObjCProtocolDecl *PrevDecl = LookupProtocol(ProtocolName, ProtocolLoc, + forRedeclarationInCurContext()); + ObjCProtocolDecl *PDecl = nullptr; + if (ObjCProtocolDecl *Def = PrevDecl? PrevDecl->getDefinition() : nullptr) { + // If we already have a definition, complain. + Diag(ProtocolLoc, diag::warn_duplicate_protocol_def) << ProtocolName; + Diag(Def->getLocation(), diag::note_previous_definition); + + // Create a new protocol that is completely distinct from previous + // declarations, and do not make this protocol available for name lookup. + // That way, we'll end up completely ignoring the duplicate. + // FIXME: Can we turn this into an error? + PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName, + ProtocolLoc, AtProtoInterfaceLoc, + /*PrevDecl=*/nullptr); + + // If we are using modules, add the decl to the context in order to + // serialize something meaningful. + if (getLangOpts().Modules) + PushOnScopeChains(PDecl, TUScope); + PDecl->startDefinition(); + } else { + if (PrevDecl) { + // Check for circular dependencies among protocol declarations. This can + // only happen if this protocol was forward-declared. + ObjCList<ObjCProtocolDecl> PList; + PList.set((ObjCProtocolDecl *const*)ProtoRefs, NumProtoRefs, Context); + err = CheckForwardProtocolDeclarationForCircularDependency( + ProtocolName, ProtocolLoc, PrevDecl->getLocation(), PList); + } + + // Create the new declaration. + PDecl = ObjCProtocolDecl::Create(Context, CurContext, ProtocolName, + ProtocolLoc, AtProtoInterfaceLoc, + /*PrevDecl=*/PrevDecl); + + PushOnScopeChains(PDecl, TUScope); + PDecl->startDefinition(); + } + + ProcessDeclAttributeList(TUScope, PDecl, AttrList); + AddPragmaAttributes(TUScope, PDecl); + + // Merge attributes from previous declarations. + if (PrevDecl) + mergeDeclAttributes(PDecl, PrevDecl); + + if (!err && NumProtoRefs ) { + /// Check then save referenced protocols. + diagnoseUseOfProtocols(*this, PDecl, (ObjCProtocolDecl*const*)ProtoRefs, + NumProtoRefs, ProtoLocs); + PDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs, + ProtoLocs, Context); + } + + CheckObjCDeclScope(PDecl); + return ActOnObjCContainerStartDefinition(PDecl); +} + +static bool NestedProtocolHasNoDefinition(ObjCProtocolDecl *PDecl, + ObjCProtocolDecl *&UndefinedProtocol) { + if (!PDecl->hasDefinition() || PDecl->getDefinition()->isHidden()) { + UndefinedProtocol = PDecl; + return true; + } + + for (auto *PI : PDecl->protocols()) + if (NestedProtocolHasNoDefinition(PI, UndefinedProtocol)) { + UndefinedProtocol = PI; + return true; + } + return false; +} + +/// FindProtocolDeclaration - This routine looks up protocols and +/// issues an error if they are not declared. It returns list of +/// protocol declarations in its 'Protocols' argument. +void +Sema::FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer, + ArrayRef<IdentifierLocPair> ProtocolId, + SmallVectorImpl<Decl *> &Protocols) { + for (const IdentifierLocPair &Pair : ProtocolId) { + ObjCProtocolDecl *PDecl = LookupProtocol(Pair.first, Pair.second); + if (!PDecl) { + TypoCorrection Corrected = CorrectTypo( + DeclarationNameInfo(Pair.first, Pair.second), + LookupObjCProtocolName, TUScope, nullptr, + llvm::make_unique<DeclFilterCCC<ObjCProtocolDecl>>(), + CTK_ErrorRecovery); + if ((PDecl = Corrected.getCorrectionDeclAs<ObjCProtocolDecl>())) + diagnoseTypo(Corrected, PDiag(diag::err_undeclared_protocol_suggest) + << Pair.first); + } + + if (!PDecl) { + Diag(Pair.second, diag::err_undeclared_protocol) << Pair.first; + continue; + } + // If this is a forward protocol declaration, get its definition. + if (!PDecl->isThisDeclarationADefinition() && PDecl->getDefinition()) + PDecl = PDecl->getDefinition(); + + // For an objc container, delay protocol reference checking until after we + // can set the objc decl as the availability context, otherwise check now. + if (!ForObjCContainer) { + (void)DiagnoseUseOfDecl(PDecl, Pair.second); + } + + // If this is a forward declaration and we are supposed to warn in this + // case, do it. + // FIXME: Recover nicely in the hidden case. + ObjCProtocolDecl *UndefinedProtocol; + + if (WarnOnDeclarations && + NestedProtocolHasNoDefinition(PDecl, UndefinedProtocol)) { + Diag(Pair.second, diag::warn_undef_protocolref) << Pair.first; + Diag(UndefinedProtocol->getLocation(), diag::note_protocol_decl_undefined) + << UndefinedProtocol; + } + Protocols.push_back(PDecl); + } +} + +namespace { +// Callback to only accept typo corrections that are either +// Objective-C protocols or valid Objective-C type arguments. +class ObjCTypeArgOrProtocolValidatorCCC : public CorrectionCandidateCallback { + ASTContext &Context; + Sema::LookupNameKind LookupKind; + public: + ObjCTypeArgOrProtocolValidatorCCC(ASTContext &context, + Sema::LookupNameKind lookupKind) + : Context(context), LookupKind(lookupKind) { } + + bool ValidateCandidate(const TypoCorrection &candidate) override { + // If we're allowed to find protocols and we have a protocol, accept it. + if (LookupKind != Sema::LookupOrdinaryName) { + if (candidate.getCorrectionDeclAs<ObjCProtocolDecl>()) + return true; + } + + // If we're allowed to find type names and we have one, accept it. + if (LookupKind != Sema::LookupObjCProtocolName) { + // If we have a type declaration, we might accept this result. + if (auto typeDecl = candidate.getCorrectionDeclAs<TypeDecl>()) { + // If we found a tag declaration outside of C++, skip it. This + // can happy because we look for any name when there is no + // bias to protocol or type names. + if (isa<RecordDecl>(typeDecl) && !Context.getLangOpts().CPlusPlus) + return false; + + // Make sure the type is something we would accept as a type + // argument. + auto type = Context.getTypeDeclType(typeDecl); + if (type->isObjCObjectPointerType() || + type->isBlockPointerType() || + type->isDependentType() || + type->isObjCObjectType()) + return true; + + return false; + } + + // If we have an Objective-C class type, accept it; there will + // be another fix to add the '*'. + if (candidate.getCorrectionDeclAs<ObjCInterfaceDecl>()) + return true; + + return false; + } + + return false; + } +}; +} // end anonymous namespace + +void Sema::DiagnoseTypeArgsAndProtocols(IdentifierInfo *ProtocolId, + SourceLocation ProtocolLoc, + IdentifierInfo *TypeArgId, + SourceLocation TypeArgLoc, + bool SelectProtocolFirst) { + Diag(TypeArgLoc, diag::err_objc_type_args_and_protocols) + << SelectProtocolFirst << TypeArgId << ProtocolId + << SourceRange(ProtocolLoc); +} + +void Sema::actOnObjCTypeArgsOrProtocolQualifiers( + Scope *S, + ParsedType baseType, + SourceLocation lAngleLoc, + ArrayRef<IdentifierInfo *> identifiers, + ArrayRef<SourceLocation> identifierLocs, + SourceLocation rAngleLoc, + SourceLocation &typeArgsLAngleLoc, + SmallVectorImpl<ParsedType> &typeArgs, + SourceLocation &typeArgsRAngleLoc, + SourceLocation &protocolLAngleLoc, + SmallVectorImpl<Decl *> &protocols, + SourceLocation &protocolRAngleLoc, + bool warnOnIncompleteProtocols) { + // Local function that updates the declaration specifiers with + // protocol information. + unsigned numProtocolsResolved = 0; + auto resolvedAsProtocols = [&] { + assert(numProtocolsResolved == identifiers.size() && "Unresolved protocols"); + + // Determine whether the base type is a parameterized class, in + // which case we want to warn about typos such as + // "NSArray<NSObject>" (that should be NSArray<NSObject *>). + ObjCInterfaceDecl *baseClass = nullptr; + QualType base = GetTypeFromParser(baseType, nullptr); + bool allAreTypeNames = false; + SourceLocation firstClassNameLoc; + if (!base.isNull()) { + if (const auto *objcObjectType = base->getAs<ObjCObjectType>()) { + baseClass = objcObjectType->getInterface(); + if (baseClass) { + if (auto typeParams = baseClass->getTypeParamList()) { + if (typeParams->size() == numProtocolsResolved) { + // Note that we should be looking for type names, too. + allAreTypeNames = true; + } + } + } + } + } + + for (unsigned i = 0, n = protocols.size(); i != n; ++i) { + ObjCProtocolDecl *&proto + = reinterpret_cast<ObjCProtocolDecl *&>(protocols[i]); + // For an objc container, delay protocol reference checking until after we + // can set the objc decl as the availability context, otherwise check now. + if (!warnOnIncompleteProtocols) { + (void)DiagnoseUseOfDecl(proto, identifierLocs[i]); + } + + // If this is a forward protocol declaration, get its definition. + if (!proto->isThisDeclarationADefinition() && proto->getDefinition()) + proto = proto->getDefinition(); + + // If this is a forward declaration and we are supposed to warn in this + // case, do it. + // FIXME: Recover nicely in the hidden case. + ObjCProtocolDecl *forwardDecl = nullptr; + if (warnOnIncompleteProtocols && + NestedProtocolHasNoDefinition(proto, forwardDecl)) { + Diag(identifierLocs[i], diag::warn_undef_protocolref) + << proto->getDeclName(); + Diag(forwardDecl->getLocation(), diag::note_protocol_decl_undefined) + << forwardDecl; + } + + // If everything this far has been a type name (and we care + // about such things), check whether this name refers to a type + // as well. + if (allAreTypeNames) { + if (auto *decl = LookupSingleName(S, identifiers[i], identifierLocs[i], + LookupOrdinaryName)) { + if (isa<ObjCInterfaceDecl>(decl)) { + if (firstClassNameLoc.isInvalid()) + firstClassNameLoc = identifierLocs[i]; + } else if (!isa<TypeDecl>(decl)) { + // Not a type. + allAreTypeNames = false; + } + } else { + allAreTypeNames = false; + } + } + } + + // All of the protocols listed also have type names, and at least + // one is an Objective-C class name. Check whether all of the + // protocol conformances are declared by the base class itself, in + // which case we warn. + if (allAreTypeNames && firstClassNameLoc.isValid()) { + llvm::SmallPtrSet<ObjCProtocolDecl*, 8> knownProtocols; + Context.CollectInheritedProtocols(baseClass, knownProtocols); + bool allProtocolsDeclared = true; + for (auto proto : protocols) { + if (knownProtocols.count(static_cast<ObjCProtocolDecl *>(proto)) == 0) { + allProtocolsDeclared = false; + break; + } + } + + if (allProtocolsDeclared) { + Diag(firstClassNameLoc, diag::warn_objc_redundant_qualified_class_type) + << baseClass->getDeclName() << SourceRange(lAngleLoc, rAngleLoc) + << FixItHint::CreateInsertion(getLocForEndOfToken(firstClassNameLoc), + " *"); + } + } + + protocolLAngleLoc = lAngleLoc; + protocolRAngleLoc = rAngleLoc; + assert(protocols.size() == identifierLocs.size()); + }; + + // Attempt to resolve all of the identifiers as protocols. + for (unsigned i = 0, n = identifiers.size(); i != n; ++i) { + ObjCProtocolDecl *proto = LookupProtocol(identifiers[i], identifierLocs[i]); + protocols.push_back(proto); + if (proto) + ++numProtocolsResolved; + } + + // If all of the names were protocols, these were protocol qualifiers. + if (numProtocolsResolved == identifiers.size()) + return resolvedAsProtocols(); + + // Attempt to resolve all of the identifiers as type names or + // Objective-C class names. The latter is technically ill-formed, + // but is probably something like \c NSArray<NSView *> missing the + // \c*. + typedef llvm::PointerUnion<TypeDecl *, ObjCInterfaceDecl *> TypeOrClassDecl; + SmallVector<TypeOrClassDecl, 4> typeDecls; + unsigned numTypeDeclsResolved = 0; + for (unsigned i = 0, n = identifiers.size(); i != n; ++i) { + NamedDecl *decl = LookupSingleName(S, identifiers[i], identifierLocs[i], + LookupOrdinaryName); + if (!decl) { + typeDecls.push_back(TypeOrClassDecl()); + continue; + } + + if (auto typeDecl = dyn_cast<TypeDecl>(decl)) { + typeDecls.push_back(typeDecl); + ++numTypeDeclsResolved; + continue; + } + + if (auto objcClass = dyn_cast<ObjCInterfaceDecl>(decl)) { + typeDecls.push_back(objcClass); + ++numTypeDeclsResolved; + continue; + } + + typeDecls.push_back(TypeOrClassDecl()); + } + + AttributeFactory attrFactory; + + // Local function that forms a reference to the given type or + // Objective-C class declaration. + auto resolveTypeReference = [&](TypeOrClassDecl typeDecl, SourceLocation loc) + -> TypeResult { + // Form declaration specifiers. They simply refer to the type. + DeclSpec DS(attrFactory); + const char* prevSpec; // unused + unsigned diagID; // unused + QualType type; + if (auto *actualTypeDecl = typeDecl.dyn_cast<TypeDecl *>()) + type = Context.getTypeDeclType(actualTypeDecl); + else + type = Context.getObjCInterfaceType(typeDecl.get<ObjCInterfaceDecl *>()); + TypeSourceInfo *parsedTSInfo = Context.getTrivialTypeSourceInfo(type, loc); + ParsedType parsedType = CreateParsedType(type, parsedTSInfo); + DS.SetTypeSpecType(DeclSpec::TST_typename, loc, prevSpec, diagID, + parsedType, Context.getPrintingPolicy()); + // Use the identifier location for the type source range. + DS.SetRangeStart(loc); + DS.SetRangeEnd(loc); + + // Form the declarator. + Declarator D(DS, DeclaratorContext::TypeNameContext); + + // If we have a typedef of an Objective-C class type that is missing a '*', + // add the '*'. + if (type->getAs<ObjCInterfaceType>()) { + SourceLocation starLoc = getLocForEndOfToken(loc); + D.AddTypeInfo(DeclaratorChunk::getPointer(/*typeQuals=*/0, starLoc, + SourceLocation(), + SourceLocation(), + SourceLocation(), + SourceLocation(), + SourceLocation()), + starLoc); + + // Diagnose the missing '*'. + Diag(loc, diag::err_objc_type_arg_missing_star) + << type + << FixItHint::CreateInsertion(starLoc, " *"); + } + + // Convert this to a type. + return ActOnTypeName(S, D); + }; + + // Local function that updates the declaration specifiers with + // type argument information. + auto resolvedAsTypeDecls = [&] { + // We did not resolve these as protocols. + protocols.clear(); + + assert(numTypeDeclsResolved == identifiers.size() && "Unresolved type decl"); + // Map type declarations to type arguments. + for (unsigned i = 0, n = identifiers.size(); i != n; ++i) { + // Map type reference to a type. + TypeResult type = resolveTypeReference(typeDecls[i], identifierLocs[i]); + if (!type.isUsable()) { + typeArgs.clear(); + return; + } + + typeArgs.push_back(type.get()); + } + + typeArgsLAngleLoc = lAngleLoc; + typeArgsRAngleLoc = rAngleLoc; + }; + + // If all of the identifiers can be resolved as type names or + // Objective-C class names, we have type arguments. + if (numTypeDeclsResolved == identifiers.size()) + return resolvedAsTypeDecls(); + + // Error recovery: some names weren't found, or we have a mix of + // type and protocol names. Go resolve all of the unresolved names + // and complain if we can't find a consistent answer. + LookupNameKind lookupKind = LookupAnyName; + for (unsigned i = 0, n = identifiers.size(); i != n; ++i) { + // If we already have a protocol or type. Check whether it is the + // right thing. + if (protocols[i] || typeDecls[i]) { + // If we haven't figured out whether we want types or protocols + // yet, try to figure it out from this name. + if (lookupKind == LookupAnyName) { + // If this name refers to both a protocol and a type (e.g., \c + // NSObject), don't conclude anything yet. + if (protocols[i] && typeDecls[i]) + continue; + + // Otherwise, let this name decide whether we'll be correcting + // toward types or protocols. + lookupKind = protocols[i] ? LookupObjCProtocolName + : LookupOrdinaryName; + continue; + } + + // If we want protocols and we have a protocol, there's nothing + // more to do. + if (lookupKind == LookupObjCProtocolName && protocols[i]) + continue; + + // If we want types and we have a type declaration, there's + // nothing more to do. + if (lookupKind == LookupOrdinaryName && typeDecls[i]) + continue; + + // We have a conflict: some names refer to protocols and others + // refer to types. + DiagnoseTypeArgsAndProtocols(identifiers[0], identifierLocs[0], + identifiers[i], identifierLocs[i], + protocols[i] != nullptr); + + protocols.clear(); + typeArgs.clear(); + return; + } + + // Perform typo correction on the name. + TypoCorrection corrected = CorrectTypo( + DeclarationNameInfo(identifiers[i], identifierLocs[i]), lookupKind, S, + nullptr, + llvm::make_unique<ObjCTypeArgOrProtocolValidatorCCC>(Context, + lookupKind), + CTK_ErrorRecovery); + if (corrected) { + // Did we find a protocol? + if (auto proto = corrected.getCorrectionDeclAs<ObjCProtocolDecl>()) { + diagnoseTypo(corrected, + PDiag(diag::err_undeclared_protocol_suggest) + << identifiers[i]); + lookupKind = LookupObjCProtocolName; + protocols[i] = proto; + ++numProtocolsResolved; + continue; + } + + // Did we find a type? + if (auto typeDecl = corrected.getCorrectionDeclAs<TypeDecl>()) { + diagnoseTypo(corrected, + PDiag(diag::err_unknown_typename_suggest) + << identifiers[i]); + lookupKind = LookupOrdinaryName; + typeDecls[i] = typeDecl; + ++numTypeDeclsResolved; + continue; + } + + // Did we find an Objective-C class? + if (auto objcClass = corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) { + diagnoseTypo(corrected, + PDiag(diag::err_unknown_type_or_class_name_suggest) + << identifiers[i] << true); + lookupKind = LookupOrdinaryName; + typeDecls[i] = objcClass; + ++numTypeDeclsResolved; + continue; + } + } + + // We couldn't find anything. + Diag(identifierLocs[i], + (lookupKind == LookupAnyName ? diag::err_objc_type_arg_missing + : lookupKind == LookupObjCProtocolName ? diag::err_undeclared_protocol + : diag::err_unknown_typename)) + << identifiers[i]; + protocols.clear(); + typeArgs.clear(); + return; + } + + // If all of the names were (corrected to) protocols, these were + // protocol qualifiers. + if (numProtocolsResolved == identifiers.size()) + return resolvedAsProtocols(); + + // Otherwise, all of the names were (corrected to) types. + assert(numTypeDeclsResolved == identifiers.size() && "Not all types?"); + return resolvedAsTypeDecls(); +} + +/// DiagnoseClassExtensionDupMethods - Check for duplicate declaration of +/// a class method in its extension. +/// +void Sema::DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT, + ObjCInterfaceDecl *ID) { + if (!ID) + return; // Possibly due to previous error + + llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap; + for (auto *MD : ID->methods()) + MethodMap[MD->getSelector()] = MD; + + if (MethodMap.empty()) + return; + for (const auto *Method : CAT->methods()) { + const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()]; + if (PrevMethod && + (PrevMethod->isInstanceMethod() == Method->isInstanceMethod()) && + !MatchTwoMethodDeclarations(Method, PrevMethod)) { + Diag(Method->getLocation(), diag::err_duplicate_method_decl) + << Method->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + } + } +} + +/// ActOnForwardProtocolDeclaration - Handle \@protocol foo; +Sema::DeclGroupPtrTy +Sema::ActOnForwardProtocolDeclaration(SourceLocation AtProtocolLoc, + ArrayRef<IdentifierLocPair> IdentList, + const ParsedAttributesView &attrList) { + SmallVector<Decl *, 8> DeclsInGroup; + for (const IdentifierLocPair &IdentPair : IdentList) { + IdentifierInfo *Ident = IdentPair.first; + ObjCProtocolDecl *PrevDecl = LookupProtocol(Ident, IdentPair.second, + forRedeclarationInCurContext()); + ObjCProtocolDecl *PDecl + = ObjCProtocolDecl::Create(Context, CurContext, Ident, + IdentPair.second, AtProtocolLoc, + PrevDecl); + + PushOnScopeChains(PDecl, TUScope); + CheckObjCDeclScope(PDecl); + + ProcessDeclAttributeList(TUScope, PDecl, attrList); + AddPragmaAttributes(TUScope, PDecl); + + if (PrevDecl) + mergeDeclAttributes(PDecl, PrevDecl); + + DeclsInGroup.push_back(PDecl); + } + + return BuildDeclaratorGroup(DeclsInGroup); +} + +Decl *Sema::ActOnStartCategoryInterface( + SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName, + SourceLocation ClassLoc, ObjCTypeParamList *typeParamList, + IdentifierInfo *CategoryName, SourceLocation CategoryLoc, + Decl *const *ProtoRefs, unsigned NumProtoRefs, + const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc, + const ParsedAttributesView &AttrList) { + ObjCCategoryDecl *CDecl; + ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true); + + /// Check that class of this category is already completely declared. + + if (!IDecl + || RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl), + diag::err_category_forward_interface, + CategoryName == nullptr)) { + // Create an invalid ObjCCategoryDecl to serve as context for + // the enclosing method declarations. We mark the decl invalid + // to make it clear that this isn't a valid AST. + CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc, + ClassLoc, CategoryLoc, CategoryName, + IDecl, typeParamList); + CDecl->setInvalidDecl(); + CurContext->addDecl(CDecl); + + if (!IDecl) + Diag(ClassLoc, diag::err_undef_interface) << ClassName; + return ActOnObjCContainerStartDefinition(CDecl); + } + + if (!CategoryName && IDecl->getImplementation()) { + Diag(ClassLoc, diag::err_class_extension_after_impl) << ClassName; + Diag(IDecl->getImplementation()->getLocation(), + diag::note_implementation_declared); + } + + if (CategoryName) { + /// Check for duplicate interface declaration for this category + if (ObjCCategoryDecl *Previous + = IDecl->FindCategoryDeclaration(CategoryName)) { + // Class extensions can be declared multiple times, categories cannot. + Diag(CategoryLoc, diag::warn_dup_category_def) + << ClassName << CategoryName; + Diag(Previous->getLocation(), diag::note_previous_definition); + } + } + + // If we have a type parameter list, check it. + if (typeParamList) { + if (auto prevTypeParamList = IDecl->getTypeParamList()) { + if (checkTypeParamListConsistency(*this, prevTypeParamList, typeParamList, + CategoryName + ? TypeParamListContext::Category + : TypeParamListContext::Extension)) + typeParamList = nullptr; + } else { + Diag(typeParamList->getLAngleLoc(), + diag::err_objc_parameterized_category_nonclass) + << (CategoryName != nullptr) + << ClassName + << typeParamList->getSourceRange(); + + typeParamList = nullptr; + } + } + + CDecl = ObjCCategoryDecl::Create(Context, CurContext, AtInterfaceLoc, + ClassLoc, CategoryLoc, CategoryName, IDecl, + typeParamList); + // FIXME: PushOnScopeChains? + CurContext->addDecl(CDecl); + + // Process the attributes before looking at protocols to ensure that the + // availability attribute is attached to the category to provide availability + // checking for protocol uses. + ProcessDeclAttributeList(TUScope, CDecl, AttrList); + AddPragmaAttributes(TUScope, CDecl); + + if (NumProtoRefs) { + diagnoseUseOfProtocols(*this, CDecl, (ObjCProtocolDecl*const*)ProtoRefs, + NumProtoRefs, ProtoLocs); + CDecl->setProtocolList((ObjCProtocolDecl*const*)ProtoRefs, NumProtoRefs, + ProtoLocs, Context); + // Protocols in the class extension belong to the class. + if (CDecl->IsClassExtension()) + IDecl->mergeClassExtensionProtocolList((ObjCProtocolDecl*const*)ProtoRefs, + NumProtoRefs, Context); + } + + CheckObjCDeclScope(CDecl); + return ActOnObjCContainerStartDefinition(CDecl); +} + +/// ActOnStartCategoryImplementation - Perform semantic checks on the +/// category implementation declaration and build an ObjCCategoryImplDecl +/// object. +Decl *Sema::ActOnStartCategoryImplementation( + SourceLocation AtCatImplLoc, + IdentifierInfo *ClassName, SourceLocation ClassLoc, + IdentifierInfo *CatName, SourceLocation CatLoc) { + ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true); + ObjCCategoryDecl *CatIDecl = nullptr; + if (IDecl && IDecl->hasDefinition()) { + CatIDecl = IDecl->FindCategoryDeclaration(CatName); + if (!CatIDecl) { + // Category @implementation with no corresponding @interface. + // Create and install one. + CatIDecl = ObjCCategoryDecl::Create(Context, CurContext, AtCatImplLoc, + ClassLoc, CatLoc, + CatName, IDecl, + /*typeParamList=*/nullptr); + CatIDecl->setImplicit(); + } + } + + ObjCCategoryImplDecl *CDecl = + ObjCCategoryImplDecl::Create(Context, CurContext, CatName, IDecl, + ClassLoc, AtCatImplLoc, CatLoc); + /// Check that class of this category is already completely declared. + if (!IDecl) { + Diag(ClassLoc, diag::err_undef_interface) << ClassName; + CDecl->setInvalidDecl(); + } else if (RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl), + diag::err_undef_interface)) { + CDecl->setInvalidDecl(); + } + + // FIXME: PushOnScopeChains? + CurContext->addDecl(CDecl); + + // If the interface has the objc_runtime_visible attribute, we + // cannot implement a category for it. + if (IDecl && IDecl->hasAttr<ObjCRuntimeVisibleAttr>()) { + Diag(ClassLoc, diag::err_objc_runtime_visible_category) + << IDecl->getDeclName(); + } + + /// Check that CatName, category name, is not used in another implementation. + if (CatIDecl) { + if (CatIDecl->getImplementation()) { + Diag(ClassLoc, diag::err_dup_implementation_category) << ClassName + << CatName; + Diag(CatIDecl->getImplementation()->getLocation(), + diag::note_previous_definition); + CDecl->setInvalidDecl(); + } else { + CatIDecl->setImplementation(CDecl); + // Warn on implementating category of deprecated class under + // -Wdeprecated-implementations flag. + DiagnoseObjCImplementedDeprecations(*this, CatIDecl, + CDecl->getLocation()); + } + } + + CheckObjCDeclScope(CDecl); + return ActOnObjCContainerStartDefinition(CDecl); +} + +Decl *Sema::ActOnStartClassImplementation( + SourceLocation AtClassImplLoc, + IdentifierInfo *ClassName, SourceLocation ClassLoc, + IdentifierInfo *SuperClassname, + SourceLocation SuperClassLoc) { + ObjCInterfaceDecl *IDecl = nullptr; + // Check for another declaration kind with the same name. + NamedDecl *PrevDecl + = LookupSingleName(TUScope, ClassName, ClassLoc, LookupOrdinaryName, + forRedeclarationInCurContext()); + if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) { + Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + } else if ((IDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl))) { + // FIXME: This will produce an error if the definition of the interface has + // been imported from a module but is not visible. + RequireCompleteType(ClassLoc, Context.getObjCInterfaceType(IDecl), + diag::warn_undef_interface); + } else { + // We did not find anything with the name ClassName; try to correct for + // typos in the class name. + TypoCorrection Corrected = CorrectTypo( + DeclarationNameInfo(ClassName, ClassLoc), LookupOrdinaryName, TUScope, + nullptr, llvm::make_unique<ObjCInterfaceValidatorCCC>(), CTK_NonError); + if (Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) { + // Suggest the (potentially) correct interface name. Don't provide a + // code-modification hint or use the typo name for recovery, because + // this is just a warning. The program may actually be correct. + diagnoseTypo(Corrected, + PDiag(diag::warn_undef_interface_suggest) << ClassName, + /*ErrorRecovery*/false); + } else { + Diag(ClassLoc, diag::warn_undef_interface) << ClassName; + } + } + + // Check that super class name is valid class name + ObjCInterfaceDecl *SDecl = nullptr; + if (SuperClassname) { + // Check if a different kind of symbol declared in this scope. + PrevDecl = LookupSingleName(TUScope, SuperClassname, SuperClassLoc, + LookupOrdinaryName); + if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) { + Diag(SuperClassLoc, diag::err_redefinition_different_kind) + << SuperClassname; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + } else { + SDecl = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl); + if (SDecl && !SDecl->hasDefinition()) + SDecl = nullptr; + if (!SDecl) + Diag(SuperClassLoc, diag::err_undef_superclass) + << SuperClassname << ClassName; + else if (IDecl && !declaresSameEntity(IDecl->getSuperClass(), SDecl)) { + // This implementation and its interface do not have the same + // super class. + Diag(SuperClassLoc, diag::err_conflicting_super_class) + << SDecl->getDeclName(); + Diag(SDecl->getLocation(), diag::note_previous_definition); + } + } + } + + if (!IDecl) { + // Legacy case of @implementation with no corresponding @interface. + // Build, chain & install the interface decl into the identifier. + + // FIXME: Do we support attributes on the @implementation? If so we should + // copy them over. + IDecl = ObjCInterfaceDecl::Create(Context, CurContext, AtClassImplLoc, + ClassName, /*typeParamList=*/nullptr, + /*PrevDecl=*/nullptr, ClassLoc, + true); + AddPragmaAttributes(TUScope, IDecl); + IDecl->startDefinition(); + if (SDecl) { + IDecl->setSuperClass(Context.getTrivialTypeSourceInfo( + Context.getObjCInterfaceType(SDecl), + SuperClassLoc)); + IDecl->setEndOfDefinitionLoc(SuperClassLoc); + } else { + IDecl->setEndOfDefinitionLoc(ClassLoc); + } + + PushOnScopeChains(IDecl, TUScope); + } else { + // Mark the interface as being completed, even if it was just as + // @class ....; + // declaration; the user cannot reopen it. + if (!IDecl->hasDefinition()) + IDecl->startDefinition(); + } + + ObjCImplementationDecl* IMPDecl = + ObjCImplementationDecl::Create(Context, CurContext, IDecl, SDecl, + ClassLoc, AtClassImplLoc, SuperClassLoc); + + if (CheckObjCDeclScope(IMPDecl)) + return ActOnObjCContainerStartDefinition(IMPDecl); + + // Check that there is no duplicate implementation of this class. + if (IDecl->getImplementation()) { + // FIXME: Don't leak everything! + Diag(ClassLoc, diag::err_dup_implementation_class) << ClassName; + Diag(IDecl->getImplementation()->getLocation(), + diag::note_previous_definition); + IMPDecl->setInvalidDecl(); + } else { // add it to the list. + IDecl->setImplementation(IMPDecl); + PushOnScopeChains(IMPDecl, TUScope); + // Warn on implementating deprecated class under + // -Wdeprecated-implementations flag. + DiagnoseObjCImplementedDeprecations(*this, IDecl, IMPDecl->getLocation()); + } + + // If the superclass has the objc_runtime_visible attribute, we + // cannot implement a subclass of it. + if (IDecl->getSuperClass() && + IDecl->getSuperClass()->hasAttr<ObjCRuntimeVisibleAttr>()) { + Diag(ClassLoc, diag::err_objc_runtime_visible_subclass) + << IDecl->getDeclName() + << IDecl->getSuperClass()->getDeclName(); + } + + return ActOnObjCContainerStartDefinition(IMPDecl); +} + +Sema::DeclGroupPtrTy +Sema::ActOnFinishObjCImplementation(Decl *ObjCImpDecl, ArrayRef<Decl *> Decls) { + SmallVector<Decl *, 64> DeclsInGroup; + DeclsInGroup.reserve(Decls.size() + 1); + + for (unsigned i = 0, e = Decls.size(); i != e; ++i) { + Decl *Dcl = Decls[i]; + if (!Dcl) + continue; + if (Dcl->getDeclContext()->isFileContext()) + Dcl->setTopLevelDeclInObjCContainer(); + DeclsInGroup.push_back(Dcl); + } + + DeclsInGroup.push_back(ObjCImpDecl); + + return BuildDeclaratorGroup(DeclsInGroup); +} + +void Sema::CheckImplementationIvars(ObjCImplementationDecl *ImpDecl, + ObjCIvarDecl **ivars, unsigned numIvars, + SourceLocation RBrace) { + assert(ImpDecl && "missing implementation decl"); + ObjCInterfaceDecl* IDecl = ImpDecl->getClassInterface(); + if (!IDecl) + return; + /// Check case of non-existing \@interface decl. + /// (legacy objective-c \@implementation decl without an \@interface decl). + /// Add implementations's ivar to the synthesize class's ivar list. + if (IDecl->isImplicitInterfaceDecl()) { + IDecl->setEndOfDefinitionLoc(RBrace); + // Add ivar's to class's DeclContext. + for (unsigned i = 0, e = numIvars; i != e; ++i) { + ivars[i]->setLexicalDeclContext(ImpDecl); + IDecl->makeDeclVisibleInContext(ivars[i]); + ImpDecl->addDecl(ivars[i]); + } + + return; + } + // If implementation has empty ivar list, just return. + if (numIvars == 0) + return; + + assert(ivars && "missing @implementation ivars"); + if (LangOpts.ObjCRuntime.isNonFragile()) { + if (ImpDecl->getSuperClass()) + Diag(ImpDecl->getLocation(), diag::warn_on_superclass_use); + for (unsigned i = 0; i < numIvars; i++) { + ObjCIvarDecl* ImplIvar = ivars[i]; + if (const ObjCIvarDecl *ClsIvar = + IDecl->getIvarDecl(ImplIvar->getIdentifier())) { + Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration); + Diag(ClsIvar->getLocation(), diag::note_previous_definition); + continue; + } + // Check class extensions (unnamed categories) for duplicate ivars. + for (const auto *CDecl : IDecl->visible_extensions()) { + if (const ObjCIvarDecl *ClsExtIvar = + CDecl->getIvarDecl(ImplIvar->getIdentifier())) { + Diag(ImplIvar->getLocation(), diag::err_duplicate_ivar_declaration); + Diag(ClsExtIvar->getLocation(), diag::note_previous_definition); + continue; + } + } + // Instance ivar to Implementation's DeclContext. + ImplIvar->setLexicalDeclContext(ImpDecl); + IDecl->makeDeclVisibleInContext(ImplIvar); + ImpDecl->addDecl(ImplIvar); + } + return; + } + // Check interface's Ivar list against those in the implementation. + // names and types must match. + // + unsigned j = 0; + ObjCInterfaceDecl::ivar_iterator + IVI = IDecl->ivar_begin(), IVE = IDecl->ivar_end(); + for (; numIvars > 0 && IVI != IVE; ++IVI) { + ObjCIvarDecl* ImplIvar = ivars[j++]; + ObjCIvarDecl* ClsIvar = *IVI; + assert (ImplIvar && "missing implementation ivar"); + assert (ClsIvar && "missing class ivar"); + + // First, make sure the types match. + if (!Context.hasSameType(ImplIvar->getType(), ClsIvar->getType())) { + Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_type) + << ImplIvar->getIdentifier() + << ImplIvar->getType() << ClsIvar->getType(); + Diag(ClsIvar->getLocation(), diag::note_previous_definition); + } else if (ImplIvar->isBitField() && ClsIvar->isBitField() && + ImplIvar->getBitWidthValue(Context) != + ClsIvar->getBitWidthValue(Context)) { + Diag(ImplIvar->getBitWidth()->getLocStart(), + diag::err_conflicting_ivar_bitwidth) << ImplIvar->getIdentifier(); + Diag(ClsIvar->getBitWidth()->getLocStart(), + diag::note_previous_definition); + } + // Make sure the names are identical. + if (ImplIvar->getIdentifier() != ClsIvar->getIdentifier()) { + Diag(ImplIvar->getLocation(), diag::err_conflicting_ivar_name) + << ImplIvar->getIdentifier() << ClsIvar->getIdentifier(); + Diag(ClsIvar->getLocation(), diag::note_previous_definition); + } + --numIvars; + } + + if (numIvars > 0) + Diag(ivars[j]->getLocation(), diag::err_inconsistent_ivar_count); + else if (IVI != IVE) + Diag(IVI->getLocation(), diag::err_inconsistent_ivar_count); +} + +static void WarnUndefinedMethod(Sema &S, SourceLocation ImpLoc, + ObjCMethodDecl *method, + bool &IncompleteImpl, + unsigned DiagID, + NamedDecl *NeededFor = nullptr) { + // No point warning no definition of method which is 'unavailable'. + if (method->getAvailability() == AR_Unavailable) + return; + + // FIXME: For now ignore 'IncompleteImpl'. + // Previously we grouped all unimplemented methods under a single + // warning, but some users strongly voiced that they would prefer + // separate warnings. We will give that approach a try, as that + // matches what we do with protocols. + { + const Sema::SemaDiagnosticBuilder &B = S.Diag(ImpLoc, DiagID); + B << method; + if (NeededFor) + B << NeededFor; + } + + // Issue a note to the original declaration. + SourceLocation MethodLoc = method->getLocStart(); + if (MethodLoc.isValid()) + S.Diag(MethodLoc, diag::note_method_declared_at) << method; +} + +/// Determines if type B can be substituted for type A. Returns true if we can +/// guarantee that anything that the user will do to an object of type A can +/// also be done to an object of type B. This is trivially true if the two +/// types are the same, or if B is a subclass of A. It becomes more complex +/// in cases where protocols are involved. +/// +/// Object types in Objective-C describe the minimum requirements for an +/// object, rather than providing a complete description of a type. For +/// example, if A is a subclass of B, then B* may refer to an instance of A. +/// The principle of substitutability means that we may use an instance of A +/// anywhere that we may use an instance of B - it will implement all of the +/// ivars of B and all of the methods of B. +/// +/// This substitutability is important when type checking methods, because +/// the implementation may have stricter type definitions than the interface. +/// The interface specifies minimum requirements, but the implementation may +/// have more accurate ones. For example, a method may privately accept +/// instances of B, but only publish that it accepts instances of A. Any +/// object passed to it will be type checked against B, and so will implicitly +/// by a valid A*. Similarly, a method may return a subclass of the class that +/// it is declared as returning. +/// +/// This is most important when considering subclassing. A method in a +/// subclass must accept any object as an argument that its superclass's +/// implementation accepts. It may, however, accept a more general type +/// without breaking substitutability (i.e. you can still use the subclass +/// anywhere that you can use the superclass, but not vice versa). The +/// converse requirement applies to return types: the return type for a +/// subclass method must be a valid object of the kind that the superclass +/// advertises, but it may be specified more accurately. This avoids the need +/// for explicit down-casting by callers. +/// +/// Note: This is a stricter requirement than for assignment. +static bool isObjCTypeSubstitutable(ASTContext &Context, + const ObjCObjectPointerType *A, + const ObjCObjectPointerType *B, + bool rejectId) { + // Reject a protocol-unqualified id. + if (rejectId && B->isObjCIdType()) return false; + + // If B is a qualified id, then A must also be a qualified id and it must + // implement all of the protocols in B. It may not be a qualified class. + // For example, MyClass<A> can be assigned to id<A>, but MyClass<A> is a + // stricter definition so it is not substitutable for id<A>. + if (B->isObjCQualifiedIdType()) { + return A->isObjCQualifiedIdType() && + Context.ObjCQualifiedIdTypesAreCompatible(QualType(A, 0), + QualType(B,0), + false); + } + + /* + // id is a special type that bypasses type checking completely. We want a + // warning when it is used in one place but not another. + if (C.isObjCIdType(A) || C.isObjCIdType(B)) return false; + + + // If B is a qualified id, then A must also be a qualified id (which it isn't + // if we've got this far) + if (B->isObjCQualifiedIdType()) return false; + */ + + // Now we know that A and B are (potentially-qualified) class types. The + // normal rules for assignment apply. + return Context.canAssignObjCInterfaces(A, B); +} + +static SourceRange getTypeRange(TypeSourceInfo *TSI) { + return (TSI ? TSI->getTypeLoc().getSourceRange() : SourceRange()); +} + +/// Determine whether two set of Objective-C declaration qualifiers conflict. +static bool objcModifiersConflict(Decl::ObjCDeclQualifier x, + Decl::ObjCDeclQualifier y) { + return (x & ~Decl::OBJC_TQ_CSNullability) != + (y & ~Decl::OBJC_TQ_CSNullability); +} + +static bool CheckMethodOverrideReturn(Sema &S, + ObjCMethodDecl *MethodImpl, + ObjCMethodDecl *MethodDecl, + bool IsProtocolMethodDecl, + bool IsOverridingMode, + bool Warn) { + if (IsProtocolMethodDecl && + objcModifiersConflict(MethodDecl->getObjCDeclQualifier(), + MethodImpl->getObjCDeclQualifier())) { + if (Warn) { + S.Diag(MethodImpl->getLocation(), + (IsOverridingMode + ? diag::warn_conflicting_overriding_ret_type_modifiers + : diag::warn_conflicting_ret_type_modifiers)) + << MethodImpl->getDeclName() + << MethodImpl->getReturnTypeSourceRange(); + S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration) + << MethodDecl->getReturnTypeSourceRange(); + } + else + return false; + } + if (Warn && IsOverridingMode && + !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) && + !S.Context.hasSameNullabilityTypeQualifier(MethodImpl->getReturnType(), + MethodDecl->getReturnType(), + false)) { + auto nullabilityMethodImpl = + *MethodImpl->getReturnType()->getNullability(S.Context); + auto nullabilityMethodDecl = + *MethodDecl->getReturnType()->getNullability(S.Context); + S.Diag(MethodImpl->getLocation(), + diag::warn_conflicting_nullability_attr_overriding_ret_types) + << DiagNullabilityKind( + nullabilityMethodImpl, + ((MethodImpl->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)) + << DiagNullabilityKind( + nullabilityMethodDecl, + ((MethodDecl->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)); + S.Diag(MethodDecl->getLocation(), diag::note_previous_declaration); + } + + if (S.Context.hasSameUnqualifiedType(MethodImpl->getReturnType(), + MethodDecl->getReturnType())) + return true; + if (!Warn) + return false; + + unsigned DiagID = + IsOverridingMode ? diag::warn_conflicting_overriding_ret_types + : diag::warn_conflicting_ret_types; + + // Mismatches between ObjC pointers go into a different warning + // category, and sometimes they're even completely whitelisted. + if (const ObjCObjectPointerType *ImplPtrTy = + MethodImpl->getReturnType()->getAs<ObjCObjectPointerType>()) { + if (const ObjCObjectPointerType *IfacePtrTy = + MethodDecl->getReturnType()->getAs<ObjCObjectPointerType>()) { + // Allow non-matching return types as long as they don't violate + // the principle of substitutability. Specifically, we permit + // return types that are subclasses of the declared return type, + // or that are more-qualified versions of the declared type. + if (isObjCTypeSubstitutable(S.Context, IfacePtrTy, ImplPtrTy, false)) + return false; + + DiagID = + IsOverridingMode ? diag::warn_non_covariant_overriding_ret_types + : diag::warn_non_covariant_ret_types; + } + } + + S.Diag(MethodImpl->getLocation(), DiagID) + << MethodImpl->getDeclName() << MethodDecl->getReturnType() + << MethodImpl->getReturnType() + << MethodImpl->getReturnTypeSourceRange(); + S.Diag(MethodDecl->getLocation(), IsOverridingMode + ? diag::note_previous_declaration + : diag::note_previous_definition) + << MethodDecl->getReturnTypeSourceRange(); + return false; +} + +static bool CheckMethodOverrideParam(Sema &S, + ObjCMethodDecl *MethodImpl, + ObjCMethodDecl *MethodDecl, + ParmVarDecl *ImplVar, + ParmVarDecl *IfaceVar, + bool IsProtocolMethodDecl, + bool IsOverridingMode, + bool Warn) { + if (IsProtocolMethodDecl && + objcModifiersConflict(ImplVar->getObjCDeclQualifier(), + IfaceVar->getObjCDeclQualifier())) { + if (Warn) { + if (IsOverridingMode) + S.Diag(ImplVar->getLocation(), + diag::warn_conflicting_overriding_param_modifiers) + << getTypeRange(ImplVar->getTypeSourceInfo()) + << MethodImpl->getDeclName(); + else S.Diag(ImplVar->getLocation(), + diag::warn_conflicting_param_modifiers) + << getTypeRange(ImplVar->getTypeSourceInfo()) + << MethodImpl->getDeclName(); + S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration) + << getTypeRange(IfaceVar->getTypeSourceInfo()); + } + else + return false; + } + + QualType ImplTy = ImplVar->getType(); + QualType IfaceTy = IfaceVar->getType(); + if (Warn && IsOverridingMode && + !isa<ObjCImplementationDecl>(MethodImpl->getDeclContext()) && + !S.Context.hasSameNullabilityTypeQualifier(ImplTy, IfaceTy, true)) { + S.Diag(ImplVar->getLocation(), + diag::warn_conflicting_nullability_attr_overriding_param_types) + << DiagNullabilityKind( + *ImplTy->getNullability(S.Context), + ((ImplVar->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)) + << DiagNullabilityKind( + *IfaceTy->getNullability(S.Context), + ((IfaceVar->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)); + S.Diag(IfaceVar->getLocation(), diag::note_previous_declaration); + } + if (S.Context.hasSameUnqualifiedType(ImplTy, IfaceTy)) + return true; + + if (!Warn) + return false; + unsigned DiagID = + IsOverridingMode ? diag::warn_conflicting_overriding_param_types + : diag::warn_conflicting_param_types; + + // Mismatches between ObjC pointers go into a different warning + // category, and sometimes they're even completely whitelisted. + if (const ObjCObjectPointerType *ImplPtrTy = + ImplTy->getAs<ObjCObjectPointerType>()) { + if (const ObjCObjectPointerType *IfacePtrTy = + IfaceTy->getAs<ObjCObjectPointerType>()) { + // Allow non-matching argument types as long as they don't + // violate the principle of substitutability. Specifically, the + // implementation must accept any objects that the superclass + // accepts, however it may also accept others. + if (isObjCTypeSubstitutable(S.Context, ImplPtrTy, IfacePtrTy, true)) + return false; + + DiagID = + IsOverridingMode ? diag::warn_non_contravariant_overriding_param_types + : diag::warn_non_contravariant_param_types; + } + } + + S.Diag(ImplVar->getLocation(), DiagID) + << getTypeRange(ImplVar->getTypeSourceInfo()) + << MethodImpl->getDeclName() << IfaceTy << ImplTy; + S.Diag(IfaceVar->getLocation(), + (IsOverridingMode ? diag::note_previous_declaration + : diag::note_previous_definition)) + << getTypeRange(IfaceVar->getTypeSourceInfo()); + return false; +} + +/// In ARC, check whether the conventional meanings of the two methods +/// match. If they don't, it's a hard error. +static bool checkMethodFamilyMismatch(Sema &S, ObjCMethodDecl *impl, + ObjCMethodDecl *decl) { + ObjCMethodFamily implFamily = impl->getMethodFamily(); + ObjCMethodFamily declFamily = decl->getMethodFamily(); + if (implFamily == declFamily) return false; + + // Since conventions are sorted by selector, the only possibility is + // that the types differ enough to cause one selector or the other + // to fall out of the family. + assert(implFamily == OMF_None || declFamily == OMF_None); + + // No further diagnostics required on invalid declarations. + if (impl->isInvalidDecl() || decl->isInvalidDecl()) return true; + + const ObjCMethodDecl *unmatched = impl; + ObjCMethodFamily family = declFamily; + unsigned errorID = diag::err_arc_lost_method_convention; + unsigned noteID = diag::note_arc_lost_method_convention; + if (declFamily == OMF_None) { + unmatched = decl; + family = implFamily; + errorID = diag::err_arc_gained_method_convention; + noteID = diag::note_arc_gained_method_convention; + } + + // Indexes into a %select clause in the diagnostic. + enum FamilySelector { + F_alloc, F_copy, F_mutableCopy = F_copy, F_init, F_new + }; + FamilySelector familySelector = FamilySelector(); + + switch (family) { + case OMF_None: llvm_unreachable("logic error, no method convention"); + case OMF_retain: + case OMF_release: + case OMF_autorelease: + case OMF_dealloc: + case OMF_finalize: + case OMF_retainCount: + case OMF_self: + case OMF_initialize: + case OMF_performSelector: + // Mismatches for these methods don't change ownership + // conventions, so we don't care. + return false; + + case OMF_init: familySelector = F_init; break; + case OMF_alloc: familySelector = F_alloc; break; + case OMF_copy: familySelector = F_copy; break; + case OMF_mutableCopy: familySelector = F_mutableCopy; break; + case OMF_new: familySelector = F_new; break; + } + + enum ReasonSelector { R_NonObjectReturn, R_UnrelatedReturn }; + ReasonSelector reasonSelector; + + // The only reason these methods don't fall within their families is + // due to unusual result types. + if (unmatched->getReturnType()->isObjCObjectPointerType()) { + reasonSelector = R_UnrelatedReturn; + } else { + reasonSelector = R_NonObjectReturn; + } + + S.Diag(impl->getLocation(), errorID) << int(familySelector) << int(reasonSelector); + S.Diag(decl->getLocation(), noteID) << int(familySelector) << int(reasonSelector); + + return true; +} + +void Sema::WarnConflictingTypedMethods(ObjCMethodDecl *ImpMethodDecl, + ObjCMethodDecl *MethodDecl, + bool IsProtocolMethodDecl) { + if (getLangOpts().ObjCAutoRefCount && + checkMethodFamilyMismatch(*this, ImpMethodDecl, MethodDecl)) + return; + + CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl, + IsProtocolMethodDecl, false, + true); + + for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(), + IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(), + EF = MethodDecl->param_end(); + IM != EM && IF != EF; ++IM, ++IF) { + CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, *IM, *IF, + IsProtocolMethodDecl, false, true); + } + + if (ImpMethodDecl->isVariadic() != MethodDecl->isVariadic()) { + Diag(ImpMethodDecl->getLocation(), + diag::warn_conflicting_variadic); + Diag(MethodDecl->getLocation(), diag::note_previous_declaration); + } +} + +void Sema::CheckConflictingOverridingMethod(ObjCMethodDecl *Method, + ObjCMethodDecl *Overridden, + bool IsProtocolMethodDecl) { + + CheckMethodOverrideReturn(*this, Method, Overridden, + IsProtocolMethodDecl, true, + true); + + for (ObjCMethodDecl::param_iterator IM = Method->param_begin(), + IF = Overridden->param_begin(), EM = Method->param_end(), + EF = Overridden->param_end(); + IM != EM && IF != EF; ++IM, ++IF) { + CheckMethodOverrideParam(*this, Method, Overridden, *IM, *IF, + IsProtocolMethodDecl, true, true); + } + + if (Method->isVariadic() != Overridden->isVariadic()) { + Diag(Method->getLocation(), + diag::warn_conflicting_overriding_variadic); + Diag(Overridden->getLocation(), diag::note_previous_declaration); + } +} + +/// WarnExactTypedMethods - This routine issues a warning if method +/// implementation declaration matches exactly that of its declaration. +void Sema::WarnExactTypedMethods(ObjCMethodDecl *ImpMethodDecl, + ObjCMethodDecl *MethodDecl, + bool IsProtocolMethodDecl) { + // don't issue warning when protocol method is optional because primary + // class is not required to implement it and it is safe for protocol + // to implement it. + if (MethodDecl->getImplementationControl() == ObjCMethodDecl::Optional) + return; + // don't issue warning when primary class's method is + // depecated/unavailable. + if (MethodDecl->hasAttr<UnavailableAttr>() || + MethodDecl->hasAttr<DeprecatedAttr>()) + return; + + bool match = CheckMethodOverrideReturn(*this, ImpMethodDecl, MethodDecl, + IsProtocolMethodDecl, false, false); + if (match) + for (ObjCMethodDecl::param_iterator IM = ImpMethodDecl->param_begin(), + IF = MethodDecl->param_begin(), EM = ImpMethodDecl->param_end(), + EF = MethodDecl->param_end(); + IM != EM && IF != EF; ++IM, ++IF) { + match = CheckMethodOverrideParam(*this, ImpMethodDecl, MethodDecl, + *IM, *IF, + IsProtocolMethodDecl, false, false); + if (!match) + break; + } + if (match) + match = (ImpMethodDecl->isVariadic() == MethodDecl->isVariadic()); + if (match) + match = !(MethodDecl->isClassMethod() && + MethodDecl->getSelector() == GetNullarySelector("load", Context)); + + if (match) { + Diag(ImpMethodDecl->getLocation(), + diag::warn_category_method_impl_match); + Diag(MethodDecl->getLocation(), diag::note_method_declared_at) + << MethodDecl->getDeclName(); + } +} + +/// FIXME: Type hierarchies in Objective-C can be deep. We could most likely +/// improve the efficiency of selector lookups and type checking by associating +/// with each protocol / interface / category the flattened instance tables. If +/// we used an immutable set to keep the table then it wouldn't add significant +/// memory cost and it would be handy for lookups. + +typedef llvm::DenseSet<IdentifierInfo*> ProtocolNameSet; +typedef std::unique_ptr<ProtocolNameSet> LazyProtocolNameSet; + +static void findProtocolsWithExplicitImpls(const ObjCProtocolDecl *PDecl, + ProtocolNameSet &PNS) { + if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>()) + PNS.insert(PDecl->getIdentifier()); + for (const auto *PI : PDecl->protocols()) + findProtocolsWithExplicitImpls(PI, PNS); +} + +/// Recursively populates a set with all conformed protocols in a class +/// hierarchy that have the 'objc_protocol_requires_explicit_implementation' +/// attribute. +static void findProtocolsWithExplicitImpls(const ObjCInterfaceDecl *Super, + ProtocolNameSet &PNS) { + if (!Super) + return; + + for (const auto *I : Super->all_referenced_protocols()) + findProtocolsWithExplicitImpls(I, PNS); + + findProtocolsWithExplicitImpls(Super->getSuperClass(), PNS); +} + +/// CheckProtocolMethodDefs - This routine checks unimplemented methods +/// Declared in protocol, and those referenced by it. +static void CheckProtocolMethodDefs(Sema &S, + SourceLocation ImpLoc, + ObjCProtocolDecl *PDecl, + bool& IncompleteImpl, + const Sema::SelectorSet &InsMap, + const Sema::SelectorSet &ClsMap, + ObjCContainerDecl *CDecl, + LazyProtocolNameSet &ProtocolsExplictImpl) { + ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl); + ObjCInterfaceDecl *IDecl = C ? C->getClassInterface() + : dyn_cast<ObjCInterfaceDecl>(CDecl); + assert (IDecl && "CheckProtocolMethodDefs - IDecl is null"); + + ObjCInterfaceDecl *Super = IDecl->getSuperClass(); + ObjCInterfaceDecl *NSIDecl = nullptr; + + // If this protocol is marked 'objc_protocol_requires_explicit_implementation' + // then we should check if any class in the super class hierarchy also + // conforms to this protocol, either directly or via protocol inheritance. + // If so, we can skip checking this protocol completely because we + // know that a parent class already satisfies this protocol. + // + // Note: we could generalize this logic for all protocols, and merely + // add the limit on looking at the super class chain for just + // specially marked protocols. This may be a good optimization. This + // change is restricted to 'objc_protocol_requires_explicit_implementation' + // protocols for now for controlled evaluation. + if (PDecl->hasAttr<ObjCExplicitProtocolImplAttr>()) { + if (!ProtocolsExplictImpl) { + ProtocolsExplictImpl.reset(new ProtocolNameSet); + findProtocolsWithExplicitImpls(Super, *ProtocolsExplictImpl); + } + if (ProtocolsExplictImpl->find(PDecl->getIdentifier()) != + ProtocolsExplictImpl->end()) + return; + + // If no super class conforms to the protocol, we should not search + // for methods in the super class to implicitly satisfy the protocol. + Super = nullptr; + } + + if (S.getLangOpts().ObjCRuntime.isNeXTFamily()) { + // check to see if class implements forwardInvocation method and objects + // of this class are derived from 'NSProxy' so that to forward requests + // from one object to another. + // Under such conditions, which means that every method possible is + // implemented in the class, we should not issue "Method definition not + // found" warnings. + // FIXME: Use a general GetUnarySelector method for this. + IdentifierInfo* II = &S.Context.Idents.get("forwardInvocation"); + Selector fISelector = S.Context.Selectors.getSelector(1, &II); + if (InsMap.count(fISelector)) + // Is IDecl derived from 'NSProxy'? If so, no instance methods + // need be implemented in the implementation. + NSIDecl = IDecl->lookupInheritedClass(&S.Context.Idents.get("NSProxy")); + } + + // If this is a forward protocol declaration, get its definition. + if (!PDecl->isThisDeclarationADefinition() && + PDecl->getDefinition()) + PDecl = PDecl->getDefinition(); + + // If a method lookup fails locally we still need to look and see if + // the method was implemented by a base class or an inherited + // protocol. This lookup is slow, but occurs rarely in correct code + // and otherwise would terminate in a warning. + + // check unimplemented instance methods. + if (!NSIDecl) + for (auto *method : PDecl->instance_methods()) { + if (method->getImplementationControl() != ObjCMethodDecl::Optional && + !method->isPropertyAccessor() && + !InsMap.count(method->getSelector()) && + (!Super || !Super->lookupMethod(method->getSelector(), + true /* instance */, + false /* shallowCategory */, + true /* followsSuper */, + nullptr /* category */))) { + // If a method is not implemented in the category implementation but + // has been declared in its primary class, superclass, + // or in one of their protocols, no need to issue the warning. + // This is because method will be implemented in the primary class + // or one of its super class implementation. + + // Ugly, but necessary. Method declared in protocol might have + // have been synthesized due to a property declared in the class which + // uses the protocol. + if (ObjCMethodDecl *MethodInClass = + IDecl->lookupMethod(method->getSelector(), + true /* instance */, + true /* shallowCategoryLookup */, + false /* followSuper */)) + if (C || MethodInClass->isPropertyAccessor()) + continue; + unsigned DIAG = diag::warn_unimplemented_protocol_method; + if (!S.Diags.isIgnored(DIAG, ImpLoc)) { + WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG, + PDecl); + } + } + } + // check unimplemented class methods + for (auto *method : PDecl->class_methods()) { + if (method->getImplementationControl() != ObjCMethodDecl::Optional && + !ClsMap.count(method->getSelector()) && + (!Super || !Super->lookupMethod(method->getSelector(), + false /* class method */, + false /* shallowCategoryLookup */, + true /* followSuper */, + nullptr /* category */))) { + // See above comment for instance method lookups. + if (C && IDecl->lookupMethod(method->getSelector(), + false /* class */, + true /* shallowCategoryLookup */, + false /* followSuper */)) + continue; + + unsigned DIAG = diag::warn_unimplemented_protocol_method; + if (!S.Diags.isIgnored(DIAG, ImpLoc)) { + WarnUndefinedMethod(S, ImpLoc, method, IncompleteImpl, DIAG, PDecl); + } + } + } + // Check on this protocols's referenced protocols, recursively. + for (auto *PI : PDecl->protocols()) + CheckProtocolMethodDefs(S, ImpLoc, PI, IncompleteImpl, InsMap, ClsMap, + CDecl, ProtocolsExplictImpl); +} + +/// MatchAllMethodDeclarations - Check methods declared in interface +/// or protocol against those declared in their implementations. +/// +void Sema::MatchAllMethodDeclarations(const SelectorSet &InsMap, + const SelectorSet &ClsMap, + SelectorSet &InsMapSeen, + SelectorSet &ClsMapSeen, + ObjCImplDecl* IMPDecl, + ObjCContainerDecl* CDecl, + bool &IncompleteImpl, + bool ImmediateClass, + bool WarnCategoryMethodImpl) { + // Check and see if instance methods in class interface have been + // implemented in the implementation class. If so, their types match. + for (auto *I : CDecl->instance_methods()) { + if (!InsMapSeen.insert(I->getSelector()).second) + continue; + if (!I->isPropertyAccessor() && + !InsMap.count(I->getSelector())) { + if (ImmediateClass) + WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl, + diag::warn_undef_method_impl); + continue; + } else { + ObjCMethodDecl *ImpMethodDecl = + IMPDecl->getInstanceMethod(I->getSelector()); + assert(CDecl->getInstanceMethod(I->getSelector(), true/*AllowHidden*/) && + "Expected to find the method through lookup as well"); + // ImpMethodDecl may be null as in a @dynamic property. + if (ImpMethodDecl) { + if (!WarnCategoryMethodImpl) + WarnConflictingTypedMethods(ImpMethodDecl, I, + isa<ObjCProtocolDecl>(CDecl)); + else if (!I->isPropertyAccessor()) + WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl)); + } + } + } + + // Check and see if class methods in class interface have been + // implemented in the implementation class. If so, their types match. + for (auto *I : CDecl->class_methods()) { + if (!ClsMapSeen.insert(I->getSelector()).second) + continue; + if (!I->isPropertyAccessor() && + !ClsMap.count(I->getSelector())) { + if (ImmediateClass) + WarnUndefinedMethod(*this, IMPDecl->getLocation(), I, IncompleteImpl, + diag::warn_undef_method_impl); + } else { + ObjCMethodDecl *ImpMethodDecl = + IMPDecl->getClassMethod(I->getSelector()); + assert(CDecl->getClassMethod(I->getSelector(), true/*AllowHidden*/) && + "Expected to find the method through lookup as well"); + // ImpMethodDecl may be null as in a @dynamic property. + if (ImpMethodDecl) { + if (!WarnCategoryMethodImpl) + WarnConflictingTypedMethods(ImpMethodDecl, I, + isa<ObjCProtocolDecl>(CDecl)); + else if (!I->isPropertyAccessor()) + WarnExactTypedMethods(ImpMethodDecl, I, isa<ObjCProtocolDecl>(CDecl)); + } + } + } + + if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl> (CDecl)) { + // Also, check for methods declared in protocols inherited by + // this protocol. + for (auto *PI : PD->protocols()) + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, PI, IncompleteImpl, false, + WarnCategoryMethodImpl); + } + + if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) { + // when checking that methods in implementation match their declaration, + // i.e. when WarnCategoryMethodImpl is false, check declarations in class + // extension; as well as those in categories. + if (!WarnCategoryMethodImpl) { + for (auto *Cat : I->visible_categories()) + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, Cat, IncompleteImpl, + ImmediateClass && Cat->IsClassExtension(), + WarnCategoryMethodImpl); + } else { + // Also methods in class extensions need be looked at next. + for (auto *Ext : I->visible_extensions()) + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, Ext, IncompleteImpl, false, + WarnCategoryMethodImpl); + } + + // Check for any implementation of a methods declared in protocol. + for (auto *PI : I->all_referenced_protocols()) + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, PI, IncompleteImpl, false, + WarnCategoryMethodImpl); + + // FIXME. For now, we are not checking for extact match of methods + // in category implementation and its primary class's super class. + if (!WarnCategoryMethodImpl && I->getSuperClass()) + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, + I->getSuperClass(), IncompleteImpl, false); + } +} + +/// CheckCategoryVsClassMethodMatches - Checks that methods implemented in +/// category matches with those implemented in its primary class and +/// warns each time an exact match is found. +void Sema::CheckCategoryVsClassMethodMatches( + ObjCCategoryImplDecl *CatIMPDecl) { + // Get category's primary class. + ObjCCategoryDecl *CatDecl = CatIMPDecl->getCategoryDecl(); + if (!CatDecl) + return; + ObjCInterfaceDecl *IDecl = CatDecl->getClassInterface(); + if (!IDecl) + return; + ObjCInterfaceDecl *SuperIDecl = IDecl->getSuperClass(); + SelectorSet InsMap, ClsMap; + + for (const auto *I : CatIMPDecl->instance_methods()) { + Selector Sel = I->getSelector(); + // When checking for methods implemented in the category, skip over + // those declared in category class's super class. This is because + // the super class must implement the method. + if (SuperIDecl && SuperIDecl->lookupMethod(Sel, true)) + continue; + InsMap.insert(Sel); + } + + for (const auto *I : CatIMPDecl->class_methods()) { + Selector Sel = I->getSelector(); + if (SuperIDecl && SuperIDecl->lookupMethod(Sel, false)) + continue; + ClsMap.insert(Sel); + } + if (InsMap.empty() && ClsMap.empty()) + return; + + SelectorSet InsMapSeen, ClsMapSeen; + bool IncompleteImpl = false; + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + CatIMPDecl, IDecl, + IncompleteImpl, false, + true /*WarnCategoryMethodImpl*/); +} + +void Sema::ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl, + ObjCContainerDecl* CDecl, + bool IncompleteImpl) { + SelectorSet InsMap; + // Check and see if instance methods in class interface have been + // implemented in the implementation class. + for (const auto *I : IMPDecl->instance_methods()) + InsMap.insert(I->getSelector()); + + // Add the selectors for getters/setters of @dynamic properties. + for (const auto *PImpl : IMPDecl->property_impls()) { + // We only care about @dynamic implementations. + if (PImpl->getPropertyImplementation() != ObjCPropertyImplDecl::Dynamic) + continue; + + const auto *P = PImpl->getPropertyDecl(); + if (!P) continue; + + InsMap.insert(P->getGetterName()); + if (!P->getSetterName().isNull()) + InsMap.insert(P->getSetterName()); + } + + // Check and see if properties declared in the interface have either 1) + // an implementation or 2) there is a @synthesize/@dynamic implementation + // of the property in the @implementation. + if (const ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(CDecl)) { + bool SynthesizeProperties = LangOpts.ObjCDefaultSynthProperties && + LangOpts.ObjCRuntime.isNonFragile() && + !IDecl->isObjCRequiresPropertyDefs(); + DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, SynthesizeProperties); + } + + // Diagnose null-resettable synthesized setters. + diagnoseNullResettableSynthesizedSetters(IMPDecl); + + SelectorSet ClsMap; + for (const auto *I : IMPDecl->class_methods()) + ClsMap.insert(I->getSelector()); + + // Check for type conflict of methods declared in a class/protocol and + // its implementation; if any. + SelectorSet InsMapSeen, ClsMapSeen; + MatchAllMethodDeclarations(InsMap, ClsMap, InsMapSeen, ClsMapSeen, + IMPDecl, CDecl, + IncompleteImpl, true); + + // check all methods implemented in category against those declared + // in its primary class. + if (ObjCCategoryImplDecl *CatDecl = + dyn_cast<ObjCCategoryImplDecl>(IMPDecl)) + CheckCategoryVsClassMethodMatches(CatDecl); + + // Check the protocol list for unimplemented methods in the @implementation + // class. + // Check and see if class methods in class interface have been + // implemented in the implementation class. + + LazyProtocolNameSet ExplicitImplProtocols; + + if (ObjCInterfaceDecl *I = dyn_cast<ObjCInterfaceDecl> (CDecl)) { + for (auto *PI : I->all_referenced_protocols()) + CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), PI, IncompleteImpl, + InsMap, ClsMap, I, ExplicitImplProtocols); + } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(CDecl)) { + // For extended class, unimplemented methods in its protocols will + // be reported in the primary class. + if (!C->IsClassExtension()) { + for (auto *P : C->protocols()) + CheckProtocolMethodDefs(*this, IMPDecl->getLocation(), P, + IncompleteImpl, InsMap, ClsMap, CDecl, + ExplicitImplProtocols); + DiagnoseUnimplementedProperties(S, IMPDecl, CDecl, + /*SynthesizeProperties=*/false); + } + } else + llvm_unreachable("invalid ObjCContainerDecl type."); +} + +Sema::DeclGroupPtrTy +Sema::ActOnForwardClassDeclaration(SourceLocation AtClassLoc, + IdentifierInfo **IdentList, + SourceLocation *IdentLocs, + ArrayRef<ObjCTypeParamList *> TypeParamLists, + unsigned NumElts) { + SmallVector<Decl *, 8> DeclsInGroup; + for (unsigned i = 0; i != NumElts; ++i) { + // Check for another declaration kind with the same name. + NamedDecl *PrevDecl + = LookupSingleName(TUScope, IdentList[i], IdentLocs[i], + LookupOrdinaryName, forRedeclarationInCurContext()); + if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) { + // GCC apparently allows the following idiom: + // + // typedef NSObject < XCElementTogglerP > XCElementToggler; + // @class XCElementToggler; + // + // Here we have chosen to ignore the forward class declaration + // with a warning. Since this is the implied behavior. + TypedefNameDecl *TDD = dyn_cast<TypedefNameDecl>(PrevDecl); + if (!TDD || !TDD->getUnderlyingType()->isObjCObjectType()) { + Diag(AtClassLoc, diag::err_redefinition_different_kind) << IdentList[i]; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + } else { + // a forward class declaration matching a typedef name of a class refers + // to the underlying class. Just ignore the forward class with a warning + // as this will force the intended behavior which is to lookup the + // typedef name. + if (isa<ObjCObjectType>(TDD->getUnderlyingType())) { + Diag(AtClassLoc, diag::warn_forward_class_redefinition) + << IdentList[i]; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + continue; + } + } + } + + // Create a declaration to describe this forward declaration. + ObjCInterfaceDecl *PrevIDecl + = dyn_cast_or_null<ObjCInterfaceDecl>(PrevDecl); + + IdentifierInfo *ClassName = IdentList[i]; + if (PrevIDecl && PrevIDecl->getIdentifier() != ClassName) { + // A previous decl with a different name is because of + // @compatibility_alias, for example: + // \code + // @class NewImage; + // @compatibility_alias OldImage NewImage; + // \endcode + // A lookup for 'OldImage' will return the 'NewImage' decl. + // + // In such a case use the real declaration name, instead of the alias one, + // otherwise we will break IdentifierResolver and redecls-chain invariants. + // FIXME: If necessary, add a bit to indicate that this ObjCInterfaceDecl + // has been aliased. + ClassName = PrevIDecl->getIdentifier(); + } + + // If this forward declaration has type parameters, compare them with the + // type parameters of the previous declaration. + ObjCTypeParamList *TypeParams = TypeParamLists[i]; + if (PrevIDecl && TypeParams) { + if (ObjCTypeParamList *PrevTypeParams = PrevIDecl->getTypeParamList()) { + // Check for consistency with the previous declaration. + if (checkTypeParamListConsistency( + *this, PrevTypeParams, TypeParams, + TypeParamListContext::ForwardDeclaration)) { + TypeParams = nullptr; + } + } else if (ObjCInterfaceDecl *Def = PrevIDecl->getDefinition()) { + // The @interface does not have type parameters. Complain. + Diag(IdentLocs[i], diag::err_objc_parameterized_forward_class) + << ClassName + << TypeParams->getSourceRange(); + Diag(Def->getLocation(), diag::note_defined_here) + << ClassName; + + TypeParams = nullptr; + } + } + + ObjCInterfaceDecl *IDecl + = ObjCInterfaceDecl::Create(Context, CurContext, AtClassLoc, + ClassName, TypeParams, PrevIDecl, + IdentLocs[i]); + IDecl->setAtEndRange(IdentLocs[i]); + + PushOnScopeChains(IDecl, TUScope); + CheckObjCDeclScope(IDecl); + DeclsInGroup.push_back(IDecl); + } + + return BuildDeclaratorGroup(DeclsInGroup); +} + +static bool tryMatchRecordTypes(ASTContext &Context, + Sema::MethodMatchStrategy strategy, + const Type *left, const Type *right); + +static bool matchTypes(ASTContext &Context, Sema::MethodMatchStrategy strategy, + QualType leftQT, QualType rightQT) { + const Type *left = + Context.getCanonicalType(leftQT).getUnqualifiedType().getTypePtr(); + const Type *right = + Context.getCanonicalType(rightQT).getUnqualifiedType().getTypePtr(); + + if (left == right) return true; + + // If we're doing a strict match, the types have to match exactly. + if (strategy == Sema::MMS_strict) return false; + + if (left->isIncompleteType() || right->isIncompleteType()) return false; + + // Otherwise, use this absurdly complicated algorithm to try to + // validate the basic, low-level compatibility of the two types. + + // As a minimum, require the sizes and alignments to match. + TypeInfo LeftTI = Context.getTypeInfo(left); + TypeInfo RightTI = Context.getTypeInfo(right); + if (LeftTI.Width != RightTI.Width) + return false; + + if (LeftTI.Align != RightTI.Align) + return false; + + // Consider all the kinds of non-dependent canonical types: + // - functions and arrays aren't possible as return and parameter types + + // - vector types of equal size can be arbitrarily mixed + if (isa<VectorType>(left)) return isa<VectorType>(right); + if (isa<VectorType>(right)) return false; + + // - references should only match references of identical type + // - structs, unions, and Objective-C objects must match more-or-less + // exactly + // - everything else should be a scalar + if (!left->isScalarType() || !right->isScalarType()) + return tryMatchRecordTypes(Context, strategy, left, right); + + // Make scalars agree in kind, except count bools as chars, and group + // all non-member pointers together. + Type::ScalarTypeKind leftSK = left->getScalarTypeKind(); + Type::ScalarTypeKind rightSK = right->getScalarTypeKind(); + if (leftSK == Type::STK_Bool) leftSK = Type::STK_Integral; + if (rightSK == Type::STK_Bool) rightSK = Type::STK_Integral; + if (leftSK == Type::STK_CPointer || leftSK == Type::STK_BlockPointer) + leftSK = Type::STK_ObjCObjectPointer; + if (rightSK == Type::STK_CPointer || rightSK == Type::STK_BlockPointer) + rightSK = Type::STK_ObjCObjectPointer; + + // Note that data member pointers and function member pointers don't + // intermix because of the size differences. + + return (leftSK == rightSK); +} + +static bool tryMatchRecordTypes(ASTContext &Context, + Sema::MethodMatchStrategy strategy, + const Type *lt, const Type *rt) { + assert(lt && rt && lt != rt); + + if (!isa<RecordType>(lt) || !isa<RecordType>(rt)) return false; + RecordDecl *left = cast<RecordType>(lt)->getDecl(); + RecordDecl *right = cast<RecordType>(rt)->getDecl(); + + // Require union-hood to match. + if (left->isUnion() != right->isUnion()) return false; + + // Require an exact match if either is non-POD. + if ((isa<CXXRecordDecl>(left) && !cast<CXXRecordDecl>(left)->isPOD()) || + (isa<CXXRecordDecl>(right) && !cast<CXXRecordDecl>(right)->isPOD())) + return false; + + // Require size and alignment to match. + TypeInfo LeftTI = Context.getTypeInfo(lt); + TypeInfo RightTI = Context.getTypeInfo(rt); + if (LeftTI.Width != RightTI.Width) + return false; + + if (LeftTI.Align != RightTI.Align) + return false; + + // Require fields to match. + RecordDecl::field_iterator li = left->field_begin(), le = left->field_end(); + RecordDecl::field_iterator ri = right->field_begin(), re = right->field_end(); + for (; li != le && ri != re; ++li, ++ri) { + if (!matchTypes(Context, strategy, li->getType(), ri->getType())) + return false; + } + return (li == le && ri == re); +} + +/// MatchTwoMethodDeclarations - Checks that two methods have matching type and +/// returns true, or false, accordingly. +/// TODO: Handle protocol list; such as id<p1,p2> in type comparisons +bool Sema::MatchTwoMethodDeclarations(const ObjCMethodDecl *left, + const ObjCMethodDecl *right, + MethodMatchStrategy strategy) { + if (!matchTypes(Context, strategy, left->getReturnType(), + right->getReturnType())) + return false; + + // If either is hidden, it is not considered to match. + if (left->isHidden() || right->isHidden()) + return false; + + if (getLangOpts().ObjCAutoRefCount && + (left->hasAttr<NSReturnsRetainedAttr>() + != right->hasAttr<NSReturnsRetainedAttr>() || + left->hasAttr<NSConsumesSelfAttr>() + != right->hasAttr<NSConsumesSelfAttr>())) + return false; + + ObjCMethodDecl::param_const_iterator + li = left->param_begin(), le = left->param_end(), ri = right->param_begin(), + re = right->param_end(); + + for (; li != le && ri != re; ++li, ++ri) { + assert(ri != right->param_end() && "Param mismatch"); + const ParmVarDecl *lparm = *li, *rparm = *ri; + + if (!matchTypes(Context, strategy, lparm->getType(), rparm->getType())) + return false; + + if (getLangOpts().ObjCAutoRefCount && + lparm->hasAttr<NSConsumedAttr>() != rparm->hasAttr<NSConsumedAttr>()) + return false; + } + return true; +} + +static bool isMethodContextSameForKindofLookup(ObjCMethodDecl *Method, + ObjCMethodDecl *MethodInList) { + auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext()); + auto *MethodInListProtocol = + dyn_cast<ObjCProtocolDecl>(MethodInList->getDeclContext()); + // If this method belongs to a protocol but the method in list does not, or + // vice versa, we say the context is not the same. + if ((MethodProtocol && !MethodInListProtocol) || + (!MethodProtocol && MethodInListProtocol)) + return false; + + if (MethodProtocol && MethodInListProtocol) + return true; + + ObjCInterfaceDecl *MethodInterface = Method->getClassInterface(); + ObjCInterfaceDecl *MethodInListInterface = + MethodInList->getClassInterface(); + return MethodInterface == MethodInListInterface; +} + +void Sema::addMethodToGlobalList(ObjCMethodList *List, + ObjCMethodDecl *Method) { + // Record at the head of the list whether there were 0, 1, or >= 2 methods + // inside categories. + if (ObjCCategoryDecl *CD = + dyn_cast<ObjCCategoryDecl>(Method->getDeclContext())) + if (!CD->IsClassExtension() && List->getBits() < 2) + List->setBits(List->getBits() + 1); + + // If the list is empty, make it a singleton list. + if (List->getMethod() == nullptr) { + List->setMethod(Method); + List->setNext(nullptr); + return; + } + + // We've seen a method with this name, see if we have already seen this type + // signature. + ObjCMethodList *Previous = List; + ObjCMethodList *ListWithSameDeclaration = nullptr; + for (; List; Previous = List, List = List->getNext()) { + // If we are building a module, keep all of the methods. + if (getLangOpts().isCompilingModule()) + continue; + + bool SameDeclaration = MatchTwoMethodDeclarations(Method, + List->getMethod()); + // Looking for method with a type bound requires the correct context exists. + // We need to insert a method into the list if the context is different. + // If the method's declaration matches the list + // a> the method belongs to a different context: we need to insert it, in + // order to emit the availability message, we need to prioritize over + // availability among the methods with the same declaration. + // b> the method belongs to the same context: there is no need to insert a + // new entry. + // If the method's declaration does not match the list, we insert it to the + // end. + if (!SameDeclaration || + !isMethodContextSameForKindofLookup(Method, List->getMethod())) { + // Even if two method types do not match, we would like to say + // there is more than one declaration so unavailability/deprecated + // warning is not too noisy. + if (!Method->isDefined()) + List->setHasMoreThanOneDecl(true); + + // For methods with the same declaration, the one that is deprecated + // should be put in the front for better diagnostics. + if (Method->isDeprecated() && SameDeclaration && + !ListWithSameDeclaration && !List->getMethod()->isDeprecated()) + ListWithSameDeclaration = List; + + if (Method->isUnavailable() && SameDeclaration && + !ListWithSameDeclaration && + List->getMethod()->getAvailability() < AR_Deprecated) + ListWithSameDeclaration = List; + continue; + } + + ObjCMethodDecl *PrevObjCMethod = List->getMethod(); + + // Propagate the 'defined' bit. + if (Method->isDefined()) + PrevObjCMethod->setDefined(true); + else { + // Objective-C doesn't allow an @interface for a class after its + // @implementation. So if Method is not defined and there already is + // an entry for this type signature, Method has to be for a different + // class than PrevObjCMethod. + List->setHasMoreThanOneDecl(true); + } + + // If a method is deprecated, push it in the global pool. + // This is used for better diagnostics. + if (Method->isDeprecated()) { + if (!PrevObjCMethod->isDeprecated()) + List->setMethod(Method); + } + // If the new method is unavailable, push it into global pool + // unless previous one is deprecated. + if (Method->isUnavailable()) { + if (PrevObjCMethod->getAvailability() < AR_Deprecated) + List->setMethod(Method); + } + + return; + } + + // We have a new signature for an existing method - add it. + // This is extremely rare. Only 1% of Cocoa selectors are "overloaded". + ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>(); + + // We insert it right before ListWithSameDeclaration. + if (ListWithSameDeclaration) { + auto *List = new (Mem) ObjCMethodList(*ListWithSameDeclaration); + // FIXME: should we clear the other bits in ListWithSameDeclaration? + ListWithSameDeclaration->setMethod(Method); + ListWithSameDeclaration->setNext(List); + return; + } + + Previous->setNext(new (Mem) ObjCMethodList(Method)); +} + +/// Read the contents of the method pool for a given selector from +/// external storage. +void Sema::ReadMethodPool(Selector Sel) { + assert(ExternalSource && "We need an external AST source"); + ExternalSource->ReadMethodPool(Sel); +} + +void Sema::updateOutOfDateSelector(Selector Sel) { + if (!ExternalSource) + return; + ExternalSource->updateOutOfDateSelector(Sel); +} + +void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl, + bool instance) { + // Ignore methods of invalid containers. + if (cast<Decl>(Method->getDeclContext())->isInvalidDecl()) + return; + + if (ExternalSource) + ReadMethodPool(Method->getSelector()); + + GlobalMethodPool::iterator Pos = MethodPool.find(Method->getSelector()); + if (Pos == MethodPool.end()) + Pos = MethodPool.insert(std::make_pair(Method->getSelector(), + GlobalMethods())).first; + + Method->setDefined(impl); + + ObjCMethodList &Entry = instance ? Pos->second.first : Pos->second.second; + addMethodToGlobalList(&Entry, Method); +} + +/// Determines if this is an "acceptable" loose mismatch in the global +/// method pool. This exists mostly as a hack to get around certain +/// global mismatches which we can't afford to make warnings / errors. +/// Really, what we want is a way to take a method out of the global +/// method pool. +static bool isAcceptableMethodMismatch(ObjCMethodDecl *chosen, + ObjCMethodDecl *other) { + if (!chosen->isInstanceMethod()) + return false; + + Selector sel = chosen->getSelector(); + if (!sel.isUnarySelector() || sel.getNameForSlot(0) != "length") + return false; + + // Don't complain about mismatches for -length if the method we + // chose has an integral result type. + return (chosen->getReturnType()->isIntegerType()); +} + +/// Return true if the given method is wthin the type bound. +static bool FilterMethodsByTypeBound(ObjCMethodDecl *Method, + const ObjCObjectType *TypeBound) { + if (!TypeBound) + return true; + + if (TypeBound->isObjCId()) + // FIXME: should we handle the case of bounding to id<A, B> differently? + return true; + + auto *BoundInterface = TypeBound->getInterface(); + assert(BoundInterface && "unexpected object type!"); + + // Check if the Method belongs to a protocol. We should allow any method + // defined in any protocol, because any subclass could adopt the protocol. + auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext()); + if (MethodProtocol) { + return true; + } + + // If the Method belongs to a class, check if it belongs to the class + // hierarchy of the class bound. + if (ObjCInterfaceDecl *MethodInterface = Method->getClassInterface()) { + // We allow methods declared within classes that are part of the hierarchy + // of the class bound (superclass of, subclass of, or the same as the class + // bound). + return MethodInterface == BoundInterface || + MethodInterface->isSuperClassOf(BoundInterface) || + BoundInterface->isSuperClassOf(MethodInterface); + } + llvm_unreachable("unknown method context"); +} + +/// We first select the type of the method: Instance or Factory, then collect +/// all methods with that type. +bool Sema::CollectMultipleMethodsInGlobalPool( + Selector Sel, SmallVectorImpl<ObjCMethodDecl *> &Methods, + bool InstanceFirst, bool CheckTheOther, + const ObjCObjectType *TypeBound) { + if (ExternalSource) + ReadMethodPool(Sel); + + GlobalMethodPool::iterator Pos = MethodPool.find(Sel); + if (Pos == MethodPool.end()) + return false; + + // Gather the non-hidden methods. + ObjCMethodList &MethList = InstanceFirst ? Pos->second.first : + Pos->second.second; + for (ObjCMethodList *M = &MethList; M; M = M->getNext()) + if (M->getMethod() && !M->getMethod()->isHidden()) { + if (FilterMethodsByTypeBound(M->getMethod(), TypeBound)) + Methods.push_back(M->getMethod()); + } + + // Return if we find any method with the desired kind. + if (!Methods.empty()) + return Methods.size() > 1; + + if (!CheckTheOther) + return false; + + // Gather the other kind. + ObjCMethodList &MethList2 = InstanceFirst ? Pos->second.second : + Pos->second.first; + for (ObjCMethodList *M = &MethList2; M; M = M->getNext()) + if (M->getMethod() && !M->getMethod()->isHidden()) { + if (FilterMethodsByTypeBound(M->getMethod(), TypeBound)) + Methods.push_back(M->getMethod()); + } + + return Methods.size() > 1; +} + +bool Sema::AreMultipleMethodsInGlobalPool( + Selector Sel, ObjCMethodDecl *BestMethod, SourceRange R, + bool receiverIdOrClass, SmallVectorImpl<ObjCMethodDecl *> &Methods) { + // Diagnose finding more than one method in global pool. + SmallVector<ObjCMethodDecl *, 4> FilteredMethods; + FilteredMethods.push_back(BestMethod); + + for (auto *M : Methods) + if (M != BestMethod && !M->hasAttr<UnavailableAttr>()) + FilteredMethods.push_back(M); + + if (FilteredMethods.size() > 1) + DiagnoseMultipleMethodInGlobalPool(FilteredMethods, Sel, R, + receiverIdOrClass); + + GlobalMethodPool::iterator Pos = MethodPool.find(Sel); + // Test for no method in the pool which should not trigger any warning by + // caller. + if (Pos == MethodPool.end()) + return true; + ObjCMethodList &MethList = + BestMethod->isInstanceMethod() ? Pos->second.first : Pos->second.second; + return MethList.hasMoreThanOneDecl(); +} + +ObjCMethodDecl *Sema::LookupMethodInGlobalPool(Selector Sel, SourceRange R, + bool receiverIdOrClass, + bool instance) { + if (ExternalSource) + ReadMethodPool(Sel); + + GlobalMethodPool::iterator Pos = MethodPool.find(Sel); + if (Pos == MethodPool.end()) + return nullptr; + + // Gather the non-hidden methods. + ObjCMethodList &MethList = instance ? Pos->second.first : Pos->second.second; + SmallVector<ObjCMethodDecl *, 4> Methods; + for (ObjCMethodList *M = &MethList; M; M = M->getNext()) { + if (M->getMethod() && !M->getMethod()->isHidden()) + return M->getMethod(); + } + return nullptr; +} + +void Sema::DiagnoseMultipleMethodInGlobalPool(SmallVectorImpl<ObjCMethodDecl*> &Methods, + Selector Sel, SourceRange R, + bool receiverIdOrClass) { + // We found multiple methods, so we may have to complain. + bool issueDiagnostic = false, issueError = false; + + // We support a warning which complains about *any* difference in + // method signature. + bool strictSelectorMatch = + receiverIdOrClass && + !Diags.isIgnored(diag::warn_strict_multiple_method_decl, R.getBegin()); + if (strictSelectorMatch) { + for (unsigned I = 1, N = Methods.size(); I != N; ++I) { + if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_strict)) { + issueDiagnostic = true; + break; + } + } + } + + // If we didn't see any strict differences, we won't see any loose + // differences. In ARC, however, we also need to check for loose + // mismatches, because most of them are errors. + if (!strictSelectorMatch || + (issueDiagnostic && getLangOpts().ObjCAutoRefCount)) + for (unsigned I = 1, N = Methods.size(); I != N; ++I) { + // This checks if the methods differ in type mismatch. + if (!MatchTwoMethodDeclarations(Methods[0], Methods[I], MMS_loose) && + !isAcceptableMethodMismatch(Methods[0], Methods[I])) { + issueDiagnostic = true; + if (getLangOpts().ObjCAutoRefCount) + issueError = true; + break; + } + } + + if (issueDiagnostic) { + if (issueError) + Diag(R.getBegin(), diag::err_arc_multiple_method_decl) << Sel << R; + else if (strictSelectorMatch) + Diag(R.getBegin(), diag::warn_strict_multiple_method_decl) << Sel << R; + else + Diag(R.getBegin(), diag::warn_multiple_method_decl) << Sel << R; + + Diag(Methods[0]->getLocStart(), + issueError ? diag::note_possibility : diag::note_using) + << Methods[0]->getSourceRange(); + for (unsigned I = 1, N = Methods.size(); I != N; ++I) { + Diag(Methods[I]->getLocStart(), diag::note_also_found) + << Methods[I]->getSourceRange(); + } + } +} + +ObjCMethodDecl *Sema::LookupImplementedMethodInGlobalPool(Selector Sel) { + GlobalMethodPool::iterator Pos = MethodPool.find(Sel); + if (Pos == MethodPool.end()) + return nullptr; + + GlobalMethods &Methods = Pos->second; + for (const ObjCMethodList *Method = &Methods.first; Method; + Method = Method->getNext()) + if (Method->getMethod() && + (Method->getMethod()->isDefined() || + Method->getMethod()->isPropertyAccessor())) + return Method->getMethod(); + + for (const ObjCMethodList *Method = &Methods.second; Method; + Method = Method->getNext()) + if (Method->getMethod() && + (Method->getMethod()->isDefined() || + Method->getMethod()->isPropertyAccessor())) + return Method->getMethod(); + return nullptr; +} + +static void +HelperSelectorsForTypoCorrection( + SmallVectorImpl<const ObjCMethodDecl *> &BestMethod, + StringRef Typo, const ObjCMethodDecl * Method) { + const unsigned MaxEditDistance = 1; + unsigned BestEditDistance = MaxEditDistance + 1; + std::string MethodName = Method->getSelector().getAsString(); + + unsigned MinPossibleEditDistance = abs((int)MethodName.size() - (int)Typo.size()); + if (MinPossibleEditDistance > 0 && + Typo.size() / MinPossibleEditDistance < 1) + return; + unsigned EditDistance = Typo.edit_distance(MethodName, true, MaxEditDistance); + if (EditDistance > MaxEditDistance) + return; + if (EditDistance == BestEditDistance) + BestMethod.push_back(Method); + else if (EditDistance < BestEditDistance) { + BestMethod.clear(); + BestMethod.push_back(Method); + } +} + +static bool HelperIsMethodInObjCType(Sema &S, Selector Sel, + QualType ObjectType) { + if (ObjectType.isNull()) + return true; + if (S.LookupMethodInObjectType(Sel, ObjectType, true/*Instance method*/)) + return true; + return S.LookupMethodInObjectType(Sel, ObjectType, false/*Class method*/) != + nullptr; +} + +const ObjCMethodDecl * +Sema::SelectorsForTypoCorrection(Selector Sel, + QualType ObjectType) { + unsigned NumArgs = Sel.getNumArgs(); + SmallVector<const ObjCMethodDecl *, 8> Methods; + bool ObjectIsId = true, ObjectIsClass = true; + if (ObjectType.isNull()) + ObjectIsId = ObjectIsClass = false; + else if (!ObjectType->isObjCObjectPointerType()) + return nullptr; + else if (const ObjCObjectPointerType *ObjCPtr = + ObjectType->getAsObjCInterfacePointerType()) { + ObjectType = QualType(ObjCPtr->getInterfaceType(), 0); + ObjectIsId = ObjectIsClass = false; + } + else if (ObjectType->isObjCIdType() || ObjectType->isObjCQualifiedIdType()) + ObjectIsClass = false; + else if (ObjectType->isObjCClassType() || ObjectType->isObjCQualifiedClassType()) + ObjectIsId = false; + else + return nullptr; + + for (GlobalMethodPool::iterator b = MethodPool.begin(), + e = MethodPool.end(); b != e; b++) { + // instance methods + for (ObjCMethodList *M = &b->second.first; M; M=M->getNext()) + if (M->getMethod() && + (M->getMethod()->getSelector().getNumArgs() == NumArgs) && + (M->getMethod()->getSelector() != Sel)) { + if (ObjectIsId) + Methods.push_back(M->getMethod()); + else if (!ObjectIsClass && + HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(), + ObjectType)) + Methods.push_back(M->getMethod()); + } + // class methods + for (ObjCMethodList *M = &b->second.second; M; M=M->getNext()) + if (M->getMethod() && + (M->getMethod()->getSelector().getNumArgs() == NumArgs) && + (M->getMethod()->getSelector() != Sel)) { + if (ObjectIsClass) + Methods.push_back(M->getMethod()); + else if (!ObjectIsId && + HelperIsMethodInObjCType(*this, M->getMethod()->getSelector(), + ObjectType)) + Methods.push_back(M->getMethod()); + } + } + + SmallVector<const ObjCMethodDecl *, 8> SelectedMethods; + for (unsigned i = 0, e = Methods.size(); i < e; i++) { + HelperSelectorsForTypoCorrection(SelectedMethods, + Sel.getAsString(), Methods[i]); + } + return (SelectedMethods.size() == 1) ? SelectedMethods[0] : nullptr; +} + +/// DiagnoseDuplicateIvars - +/// Check for duplicate ivars in the entire class at the start of +/// \@implementation. This becomes necesssary because class extension can +/// add ivars to a class in random order which will not be known until +/// class's \@implementation is seen. +void Sema::DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID, + ObjCInterfaceDecl *SID) { + for (auto *Ivar : ID->ivars()) { + if (Ivar->isInvalidDecl()) + continue; + if (IdentifierInfo *II = Ivar->getIdentifier()) { + ObjCIvarDecl* prevIvar = SID->lookupInstanceVariable(II); + if (prevIvar) { + Diag(Ivar->getLocation(), diag::err_duplicate_member) << II; + Diag(prevIvar->getLocation(), diag::note_previous_declaration); + Ivar->setInvalidDecl(); + } + } + } +} + +/// Diagnose attempts to define ARC-__weak ivars when __weak is disabled. +static void DiagnoseWeakIvars(Sema &S, ObjCImplementationDecl *ID) { + if (S.getLangOpts().ObjCWeak) return; + + for (auto ivar = ID->getClassInterface()->all_declared_ivar_begin(); + ivar; ivar = ivar->getNextIvar()) { + if (ivar->isInvalidDecl()) continue; + if (ivar->getType().getObjCLifetime() == Qualifiers::OCL_Weak) { + if (S.getLangOpts().ObjCWeakRuntime) { + S.Diag(ivar->getLocation(), diag::err_arc_weak_disabled); + } else { + S.Diag(ivar->getLocation(), diag::err_arc_weak_no_runtime); + } + } + } +} + +/// Diagnose attempts to use flexible array member with retainable object type. +static void DiagnoseRetainableFlexibleArrayMember(Sema &S, + ObjCInterfaceDecl *ID) { + if (!S.getLangOpts().ObjCAutoRefCount) + return; + + for (auto ivar = ID->all_declared_ivar_begin(); ivar; + ivar = ivar->getNextIvar()) { + if (ivar->isInvalidDecl()) + continue; + QualType IvarTy = ivar->getType(); + if (IvarTy->isIncompleteArrayType() && + (IvarTy.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) && + IvarTy->isObjCLifetimeType()) { + S.Diag(ivar->getLocation(), diag::err_flexible_array_arc_retainable); + ivar->setInvalidDecl(); + } + } +} + +Sema::ObjCContainerKind Sema::getObjCContainerKind() const { + switch (CurContext->getDeclKind()) { + case Decl::ObjCInterface: + return Sema::OCK_Interface; + case Decl::ObjCProtocol: + return Sema::OCK_Protocol; + case Decl::ObjCCategory: + if (cast<ObjCCategoryDecl>(CurContext)->IsClassExtension()) + return Sema::OCK_ClassExtension; + return Sema::OCK_Category; + case Decl::ObjCImplementation: + return Sema::OCK_Implementation; + case Decl::ObjCCategoryImpl: + return Sema::OCK_CategoryImplementation; + + default: + return Sema::OCK_None; + } +} + +static bool IsVariableSizedType(QualType T) { + if (T->isIncompleteArrayType()) + return true; + const auto *RecordTy = T->getAs<RecordType>(); + return (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()); +} + +static void DiagnoseVariableSizedIvars(Sema &S, ObjCContainerDecl *OCD) { + ObjCInterfaceDecl *IntfDecl = nullptr; + ObjCInterfaceDecl::ivar_range Ivars = llvm::make_range( + ObjCInterfaceDecl::ivar_iterator(), ObjCInterfaceDecl::ivar_iterator()); + if ((IntfDecl = dyn_cast<ObjCInterfaceDecl>(OCD))) { + Ivars = IntfDecl->ivars(); + } else if (auto *ImplDecl = dyn_cast<ObjCImplementationDecl>(OCD)) { + IntfDecl = ImplDecl->getClassInterface(); + Ivars = ImplDecl->ivars(); + } else if (auto *CategoryDecl = dyn_cast<ObjCCategoryDecl>(OCD)) { + if (CategoryDecl->IsClassExtension()) { + IntfDecl = CategoryDecl->getClassInterface(); + Ivars = CategoryDecl->ivars(); + } + } + + // Check if variable sized ivar is in interface and visible to subclasses. + if (!isa<ObjCInterfaceDecl>(OCD)) { + for (auto ivar : Ivars) { + if (!ivar->isInvalidDecl() && IsVariableSizedType(ivar->getType())) { + S.Diag(ivar->getLocation(), diag::warn_variable_sized_ivar_visibility) + << ivar->getDeclName() << ivar->getType(); + } + } + } + + // Subsequent checks require interface decl. + if (!IntfDecl) + return; + + // Check if variable sized ivar is followed by another ivar. + for (ObjCIvarDecl *ivar = IntfDecl->all_declared_ivar_begin(); ivar; + ivar = ivar->getNextIvar()) { + if (ivar->isInvalidDecl() || !ivar->getNextIvar()) + continue; + QualType IvarTy = ivar->getType(); + bool IsInvalidIvar = false; + if (IvarTy->isIncompleteArrayType()) { + S.Diag(ivar->getLocation(), diag::err_flexible_array_not_at_end) + << ivar->getDeclName() << IvarTy + << TTK_Class; // Use "class" for Obj-C. + IsInvalidIvar = true; + } else if (const RecordType *RecordTy = IvarTy->getAs<RecordType>()) { + if (RecordTy->getDecl()->hasFlexibleArrayMember()) { + S.Diag(ivar->getLocation(), + diag::err_objc_variable_sized_type_not_at_end) + << ivar->getDeclName() << IvarTy; + IsInvalidIvar = true; + } + } + if (IsInvalidIvar) { + S.Diag(ivar->getNextIvar()->getLocation(), + diag::note_next_ivar_declaration) + << ivar->getNextIvar()->getSynthesize(); + ivar->setInvalidDecl(); + } + } + + // Check if ObjC container adds ivars after variable sized ivar in superclass. + // Perform the check only if OCD is the first container to declare ivars to + // avoid multiple warnings for the same ivar. + ObjCIvarDecl *FirstIvar = + (Ivars.begin() == Ivars.end()) ? nullptr : *Ivars.begin(); + if (FirstIvar && (FirstIvar == IntfDecl->all_declared_ivar_begin())) { + const ObjCInterfaceDecl *SuperClass = IntfDecl->getSuperClass(); + while (SuperClass && SuperClass->ivar_empty()) + SuperClass = SuperClass->getSuperClass(); + if (SuperClass) { + auto IvarIter = SuperClass->ivar_begin(); + std::advance(IvarIter, SuperClass->ivar_size() - 1); + const ObjCIvarDecl *LastIvar = *IvarIter; + if (IsVariableSizedType(LastIvar->getType())) { + S.Diag(FirstIvar->getLocation(), + diag::warn_superclass_variable_sized_type_not_at_end) + << FirstIvar->getDeclName() << LastIvar->getDeclName() + << LastIvar->getType() << SuperClass->getDeclName(); + S.Diag(LastIvar->getLocation(), diag::note_entity_declared_at) + << LastIvar->getDeclName(); + } + } + } +} + +// Note: For class/category implementations, allMethods is always null. +Decl *Sema::ActOnAtEnd(Scope *S, SourceRange AtEnd, ArrayRef<Decl *> allMethods, + ArrayRef<DeclGroupPtrTy> allTUVars) { + if (getObjCContainerKind() == Sema::OCK_None) + return nullptr; + + assert(AtEnd.isValid() && "Invalid location for '@end'"); + + auto *OCD = cast<ObjCContainerDecl>(CurContext); + Decl *ClassDecl = OCD; + + bool isInterfaceDeclKind = + isa<ObjCInterfaceDecl>(ClassDecl) || isa<ObjCCategoryDecl>(ClassDecl) + || isa<ObjCProtocolDecl>(ClassDecl); + bool checkIdenticalMethods = isa<ObjCImplementationDecl>(ClassDecl); + + // FIXME: Remove these and use the ObjCContainerDecl/DeclContext. + llvm::DenseMap<Selector, const ObjCMethodDecl*> InsMap; + llvm::DenseMap<Selector, const ObjCMethodDecl*> ClsMap; + + for (unsigned i = 0, e = allMethods.size(); i != e; i++ ) { + ObjCMethodDecl *Method = + cast_or_null<ObjCMethodDecl>(allMethods[i]); + + if (!Method) continue; // Already issued a diagnostic. + if (Method->isInstanceMethod()) { + /// Check for instance method of the same name with incompatible types + const ObjCMethodDecl *&PrevMethod = InsMap[Method->getSelector()]; + bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod) + : false; + if ((isInterfaceDeclKind && PrevMethod && !match) + || (checkIdenticalMethods && match)) { + Diag(Method->getLocation(), diag::err_duplicate_method_decl) + << Method->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + Method->setInvalidDecl(); + } else { + if (PrevMethod) { + Method->setAsRedeclaration(PrevMethod); + if (!Context.getSourceManager().isInSystemHeader( + Method->getLocation())) + Diag(Method->getLocation(), diag::warn_duplicate_method_decl) + << Method->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + } + InsMap[Method->getSelector()] = Method; + /// The following allows us to typecheck messages to "id". + AddInstanceMethodToGlobalPool(Method); + } + } else { + /// Check for class method of the same name with incompatible types + const ObjCMethodDecl *&PrevMethod = ClsMap[Method->getSelector()]; + bool match = PrevMethod ? MatchTwoMethodDeclarations(Method, PrevMethod) + : false; + if ((isInterfaceDeclKind && PrevMethod && !match) + || (checkIdenticalMethods && match)) { + Diag(Method->getLocation(), diag::err_duplicate_method_decl) + << Method->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + Method->setInvalidDecl(); + } else { + if (PrevMethod) { + Method->setAsRedeclaration(PrevMethod); + if (!Context.getSourceManager().isInSystemHeader( + Method->getLocation())) + Diag(Method->getLocation(), diag::warn_duplicate_method_decl) + << Method->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + } + ClsMap[Method->getSelector()] = Method; + AddFactoryMethodToGlobalPool(Method); + } + } + } + if (isa<ObjCInterfaceDecl>(ClassDecl)) { + // Nothing to do here. + } else if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(ClassDecl)) { + // Categories are used to extend the class by declaring new methods. + // By the same token, they are also used to add new properties. No + // need to compare the added property to those in the class. + + if (C->IsClassExtension()) { + ObjCInterfaceDecl *CCPrimary = C->getClassInterface(); + DiagnoseClassExtensionDupMethods(C, CCPrimary); + } + } + if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) { + if (CDecl->getIdentifier()) + // ProcessPropertyDecl is responsible for diagnosing conflicts with any + // user-defined setter/getter. It also synthesizes setter/getter methods + // and adds them to the DeclContext and global method pools. + for (auto *I : CDecl->properties()) + ProcessPropertyDecl(I); + CDecl->setAtEndRange(AtEnd); + } + if (ObjCImplementationDecl *IC=dyn_cast<ObjCImplementationDecl>(ClassDecl)) { + IC->setAtEndRange(AtEnd); + if (ObjCInterfaceDecl* IDecl = IC->getClassInterface()) { + // Any property declared in a class extension might have user + // declared setter or getter in current class extension or one + // of the other class extensions. Mark them as synthesized as + // property will be synthesized when property with same name is + // seen in the @implementation. + for (const auto *Ext : IDecl->visible_extensions()) { + for (const auto *Property : Ext->instance_properties()) { + // Skip over properties declared @dynamic + if (const ObjCPropertyImplDecl *PIDecl + = IC->FindPropertyImplDecl(Property->getIdentifier(), + Property->getQueryKind())) + if (PIDecl->getPropertyImplementation() + == ObjCPropertyImplDecl::Dynamic) + continue; + + for (const auto *Ext : IDecl->visible_extensions()) { + if (ObjCMethodDecl *GetterMethod + = Ext->getInstanceMethod(Property->getGetterName())) + GetterMethod->setPropertyAccessor(true); + if (!Property->isReadOnly()) + if (ObjCMethodDecl *SetterMethod + = Ext->getInstanceMethod(Property->getSetterName())) + SetterMethod->setPropertyAccessor(true); + } + } + } + ImplMethodsVsClassMethods(S, IC, IDecl); + AtomicPropertySetterGetterRules(IC, IDecl); + DiagnoseOwningPropertyGetterSynthesis(IC); + DiagnoseUnusedBackingIvarInAccessor(S, IC); + if (IDecl->hasDesignatedInitializers()) + DiagnoseMissingDesignatedInitOverrides(IC, IDecl); + DiagnoseWeakIvars(*this, IC); + DiagnoseRetainableFlexibleArrayMember(*this, IDecl); + + bool HasRootClassAttr = IDecl->hasAttr<ObjCRootClassAttr>(); + if (IDecl->getSuperClass() == nullptr) { + // This class has no superclass, so check that it has been marked with + // __attribute((objc_root_class)). + if (!HasRootClassAttr) { + SourceLocation DeclLoc(IDecl->getLocation()); + SourceLocation SuperClassLoc(getLocForEndOfToken(DeclLoc)); + Diag(DeclLoc, diag::warn_objc_root_class_missing) + << IDecl->getIdentifier(); + // See if NSObject is in the current scope, and if it is, suggest + // adding " : NSObject " to the class declaration. + NamedDecl *IF = LookupSingleName(TUScope, + NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject), + DeclLoc, LookupOrdinaryName); + ObjCInterfaceDecl *NSObjectDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF); + if (NSObjectDecl && NSObjectDecl->getDefinition()) { + Diag(SuperClassLoc, diag::note_objc_needs_superclass) + << FixItHint::CreateInsertion(SuperClassLoc, " : NSObject "); + } else { + Diag(SuperClassLoc, diag::note_objc_needs_superclass); + } + } + } else if (HasRootClassAttr) { + // Complain that only root classes may have this attribute. + Diag(IDecl->getLocation(), diag::err_objc_root_class_subclass); + } + + if (const ObjCInterfaceDecl *Super = IDecl->getSuperClass()) { + // An interface can subclass another interface with a + // objc_subclassing_restricted attribute when it has that attribute as + // well (because of interfaces imported from Swift). Therefore we have + // to check if we can subclass in the implementation as well. + if (IDecl->hasAttr<ObjCSubclassingRestrictedAttr>() && + Super->hasAttr<ObjCSubclassingRestrictedAttr>()) { + Diag(IC->getLocation(), diag::err_restricted_superclass_mismatch); + Diag(Super->getLocation(), diag::note_class_declared); + } + } + + if (LangOpts.ObjCRuntime.isNonFragile()) { + while (IDecl->getSuperClass()) { + DiagnoseDuplicateIvars(IDecl, IDecl->getSuperClass()); + IDecl = IDecl->getSuperClass(); + } + } + } + SetIvarInitializers(IC); + } else if (ObjCCategoryImplDecl* CatImplClass = + dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) { + CatImplClass->setAtEndRange(AtEnd); + + // Find category interface decl and then check that all methods declared + // in this interface are implemented in the category @implementation. + if (ObjCInterfaceDecl* IDecl = CatImplClass->getClassInterface()) { + if (ObjCCategoryDecl *Cat + = IDecl->FindCategoryDeclaration(CatImplClass->getIdentifier())) { + ImplMethodsVsClassMethods(S, CatImplClass, Cat); + } + } + } else if (const auto *IntfDecl = dyn_cast<ObjCInterfaceDecl>(ClassDecl)) { + if (const ObjCInterfaceDecl *Super = IntfDecl->getSuperClass()) { + if (!IntfDecl->hasAttr<ObjCSubclassingRestrictedAttr>() && + Super->hasAttr<ObjCSubclassingRestrictedAttr>()) { + Diag(IntfDecl->getLocation(), diag::err_restricted_superclass_mismatch); + Diag(Super->getLocation(), diag::note_class_declared); + } + } + } + DiagnoseVariableSizedIvars(*this, OCD); + if (isInterfaceDeclKind) { + // Reject invalid vardecls. + for (unsigned i = 0, e = allTUVars.size(); i != e; i++) { + DeclGroupRef DG = allTUVars[i].get(); + for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) + if (VarDecl *VDecl = dyn_cast<VarDecl>(*I)) { + if (!VDecl->hasExternalStorage()) + Diag(VDecl->getLocation(), diag::err_objc_var_decl_inclass); + } + } + } + ActOnObjCContainerFinishDefinition(); + + for (unsigned i = 0, e = allTUVars.size(); i != e; i++) { + DeclGroupRef DG = allTUVars[i].get(); + for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) + (*I)->setTopLevelDeclInObjCContainer(); + Consumer.HandleTopLevelDeclInObjCContainer(DG); + } + + ActOnDocumentableDecl(ClassDecl); + return ClassDecl; +} + +/// CvtQTToAstBitMask - utility routine to produce an AST bitmask for +/// objective-c's type qualifier from the parser version of the same info. +static Decl::ObjCDeclQualifier +CvtQTToAstBitMask(ObjCDeclSpec::ObjCDeclQualifier PQTVal) { + return (Decl::ObjCDeclQualifier) (unsigned) PQTVal; +} + +/// Check whether the declared result type of the given Objective-C +/// method declaration is compatible with the method's class. +/// +static Sema::ResultTypeCompatibilityKind +CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method, + ObjCInterfaceDecl *CurrentClass) { + QualType ResultType = Method->getReturnType(); + + // If an Objective-C method inherits its related result type, then its + // declared result type must be compatible with its own class type. The + // declared result type is compatible if: + if (const ObjCObjectPointerType *ResultObjectType + = ResultType->getAs<ObjCObjectPointerType>()) { + // - it is id or qualified id, or + if (ResultObjectType->isObjCIdType() || + ResultObjectType->isObjCQualifiedIdType()) + return Sema::RTC_Compatible; + + if (CurrentClass) { + if (ObjCInterfaceDecl *ResultClass + = ResultObjectType->getInterfaceDecl()) { + // - it is the same as the method's class type, or + if (declaresSameEntity(CurrentClass, ResultClass)) + return Sema::RTC_Compatible; + + // - it is a superclass of the method's class type + if (ResultClass->isSuperClassOf(CurrentClass)) + return Sema::RTC_Compatible; + } + } else { + // Any Objective-C pointer type might be acceptable for a protocol + // method; we just don't know. + return Sema::RTC_Unknown; + } + } + + return Sema::RTC_Incompatible; +} + +namespace { +/// A helper class for searching for methods which a particular method +/// overrides. +class OverrideSearch { +public: + Sema &S; + ObjCMethodDecl *Method; + llvm::SmallSetVector<ObjCMethodDecl*, 4> Overridden; + bool Recursive; + +public: + OverrideSearch(Sema &S, ObjCMethodDecl *method) : S(S), Method(method) { + Selector selector = method->getSelector(); + + // Bypass this search if we've never seen an instance/class method + // with this selector before. + Sema::GlobalMethodPool::iterator it = S.MethodPool.find(selector); + if (it == S.MethodPool.end()) { + if (!S.getExternalSource()) return; + S.ReadMethodPool(selector); + + it = S.MethodPool.find(selector); + if (it == S.MethodPool.end()) + return; + } + ObjCMethodList &list = + method->isInstanceMethod() ? it->second.first : it->second.second; + if (!list.getMethod()) return; + + ObjCContainerDecl *container + = cast<ObjCContainerDecl>(method->getDeclContext()); + + // Prevent the search from reaching this container again. This is + // important with categories, which override methods from the + // interface and each other. + if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(container)) { + searchFromContainer(container); + if (ObjCInterfaceDecl *Interface = Category->getClassInterface()) + searchFromContainer(Interface); + } else { + searchFromContainer(container); + } + } + + typedef decltype(Overridden)::iterator iterator; + iterator begin() const { return Overridden.begin(); } + iterator end() const { return Overridden.end(); } + +private: + void searchFromContainer(ObjCContainerDecl *container) { + if (container->isInvalidDecl()) return; + + switch (container->getDeclKind()) { +#define OBJCCONTAINER(type, base) \ + case Decl::type: \ + searchFrom(cast<type##Decl>(container)); \ + break; +#define ABSTRACT_DECL(expansion) +#define DECL(type, base) \ + case Decl::type: +#include "clang/AST/DeclNodes.inc" + llvm_unreachable("not an ObjC container!"); + } + } + + void searchFrom(ObjCProtocolDecl *protocol) { + if (!protocol->hasDefinition()) + return; + + // A method in a protocol declaration overrides declarations from + // referenced ("parent") protocols. + search(protocol->getReferencedProtocols()); + } + + void searchFrom(ObjCCategoryDecl *category) { + // A method in a category declaration overrides declarations from + // the main class and from protocols the category references. + // The main class is handled in the constructor. + search(category->getReferencedProtocols()); + } + + void searchFrom(ObjCCategoryImplDecl *impl) { + // A method in a category definition that has a category + // declaration overrides declarations from the category + // declaration. + if (ObjCCategoryDecl *category = impl->getCategoryDecl()) { + search(category); + if (ObjCInterfaceDecl *Interface = category->getClassInterface()) + search(Interface); + + // Otherwise it overrides declarations from the class. + } else if (ObjCInterfaceDecl *Interface = impl->getClassInterface()) { + search(Interface); + } + } + + void searchFrom(ObjCInterfaceDecl *iface) { + // A method in a class declaration overrides declarations from + if (!iface->hasDefinition()) + return; + + // - categories, + for (auto *Cat : iface->known_categories()) + search(Cat); + + // - the super class, and + if (ObjCInterfaceDecl *super = iface->getSuperClass()) + search(super); + + // - any referenced protocols. + search(iface->getReferencedProtocols()); + } + + void searchFrom(ObjCImplementationDecl *impl) { + // A method in a class implementation overrides declarations from + // the class interface. + if (ObjCInterfaceDecl *Interface = impl->getClassInterface()) + search(Interface); + } + + void search(const ObjCProtocolList &protocols) { + for (ObjCProtocolList::iterator i = protocols.begin(), e = protocols.end(); + i != e; ++i) + search(*i); + } + + void search(ObjCContainerDecl *container) { + // Check for a method in this container which matches this selector. + ObjCMethodDecl *meth = container->getMethod(Method->getSelector(), + Method->isInstanceMethod(), + /*AllowHidden=*/true); + + // If we find one, record it and bail out. + if (meth) { + Overridden.insert(meth); + return; + } + + // Otherwise, search for methods that a hypothetical method here + // would have overridden. + + // Note that we're now in a recursive case. + Recursive = true; + + searchFromContainer(container); + } +}; +} // end anonymous namespace + +void Sema::CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod, + ObjCInterfaceDecl *CurrentClass, + ResultTypeCompatibilityKind RTC) { + // Search for overridden methods and merge information down from them. + OverrideSearch overrides(*this, ObjCMethod); + // Keep track if the method overrides any method in the class's base classes, + // its protocols, or its categories' protocols; we will keep that info + // in the ObjCMethodDecl. + // For this info, a method in an implementation is not considered as + // overriding the same method in the interface or its categories. + bool hasOverriddenMethodsInBaseOrProtocol = false; + for (OverrideSearch::iterator + i = overrides.begin(), e = overrides.end(); i != e; ++i) { + ObjCMethodDecl *overridden = *i; + + if (!hasOverriddenMethodsInBaseOrProtocol) { + if (isa<ObjCProtocolDecl>(overridden->getDeclContext()) || + CurrentClass != overridden->getClassInterface() || + overridden->isOverriding()) { + hasOverriddenMethodsInBaseOrProtocol = true; + + } else if (isa<ObjCImplDecl>(ObjCMethod->getDeclContext())) { + // OverrideSearch will return as "overridden" the same method in the + // interface. For hasOverriddenMethodsInBaseOrProtocol, we need to + // check whether a category of a base class introduced a method with the + // same selector, after the interface method declaration. + // To avoid unnecessary lookups in the majority of cases, we use the + // extra info bits in GlobalMethodPool to check whether there were any + // category methods with this selector. + GlobalMethodPool::iterator It = + MethodPool.find(ObjCMethod->getSelector()); + if (It != MethodPool.end()) { + ObjCMethodList &List = + ObjCMethod->isInstanceMethod()? It->second.first: It->second.second; + unsigned CategCount = List.getBits(); + if (CategCount > 0) { + // If the method is in a category we'll do lookup if there were at + // least 2 category methods recorded, otherwise only one will do. + if (CategCount > 1 || + !isa<ObjCCategoryImplDecl>(overridden->getDeclContext())) { + OverrideSearch overrides(*this, overridden); + for (OverrideSearch::iterator + OI= overrides.begin(), OE= overrides.end(); OI!=OE; ++OI) { + ObjCMethodDecl *SuperOverridden = *OI; + if (isa<ObjCProtocolDecl>(SuperOverridden->getDeclContext()) || + CurrentClass != SuperOverridden->getClassInterface()) { + hasOverriddenMethodsInBaseOrProtocol = true; + overridden->setOverriding(true); + break; + } + } + } + } + } + } + } + + // Propagate down the 'related result type' bit from overridden methods. + if (RTC != Sema::RTC_Incompatible && overridden->hasRelatedResultType()) + ObjCMethod->SetRelatedResultType(); + + // Then merge the declarations. + mergeObjCMethodDecls(ObjCMethod, overridden); + + if (ObjCMethod->isImplicit() && overridden->isImplicit()) + continue; // Conflicting properties are detected elsewhere. + + // Check for overriding methods + if (isa<ObjCInterfaceDecl>(ObjCMethod->getDeclContext()) || + isa<ObjCImplementationDecl>(ObjCMethod->getDeclContext())) + CheckConflictingOverridingMethod(ObjCMethod, overridden, + isa<ObjCProtocolDecl>(overridden->getDeclContext())); + + if (CurrentClass && overridden->getDeclContext() != CurrentClass && + isa<ObjCInterfaceDecl>(overridden->getDeclContext()) && + !overridden->isImplicit() /* not meant for properties */) { + ObjCMethodDecl::param_iterator ParamI = ObjCMethod->param_begin(), + E = ObjCMethod->param_end(); + ObjCMethodDecl::param_iterator PrevI = overridden->param_begin(), + PrevE = overridden->param_end(); + for (; ParamI != E && PrevI != PrevE; ++ParamI, ++PrevI) { + assert(PrevI != overridden->param_end() && "Param mismatch"); + QualType T1 = Context.getCanonicalType((*ParamI)->getType()); + QualType T2 = Context.getCanonicalType((*PrevI)->getType()); + // If type of argument of method in this class does not match its + // respective argument type in the super class method, issue warning; + if (!Context.typesAreCompatible(T1, T2)) { + Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super) + << T1 << T2; + Diag(overridden->getLocation(), diag::note_previous_declaration); + break; + } + } + } + } + + ObjCMethod->setOverriding(hasOverriddenMethodsInBaseOrProtocol); +} + +/// Merge type nullability from for a redeclaration of the same entity, +/// producing the updated type of the redeclared entity. +static QualType mergeTypeNullabilityForRedecl(Sema &S, SourceLocation loc, + QualType type, + bool usesCSKeyword, + SourceLocation prevLoc, + QualType prevType, + bool prevUsesCSKeyword) { + // Determine the nullability of both types. + auto nullability = type->getNullability(S.Context); + auto prevNullability = prevType->getNullability(S.Context); + + // Easy case: both have nullability. + if (nullability.hasValue() == prevNullability.hasValue()) { + // Neither has nullability; continue. + if (!nullability) + return type; + + // The nullabilities are equivalent; do nothing. + if (*nullability == *prevNullability) + return type; + + // Complain about mismatched nullability. + S.Diag(loc, diag::err_nullability_conflicting) + << DiagNullabilityKind(*nullability, usesCSKeyword) + << DiagNullabilityKind(*prevNullability, prevUsesCSKeyword); + return type; + } + + // If it's the redeclaration that has nullability, don't change anything. + if (nullability) + return type; + + // Otherwise, provide the result with the same nullability. + return S.Context.getAttributedType( + AttributedType::getNullabilityAttrKind(*prevNullability), + type, type); +} + +/// Merge information from the declaration of a method in the \@interface +/// (or a category/extension) into the corresponding method in the +/// @implementation (for a class or category). +static void mergeInterfaceMethodToImpl(Sema &S, + ObjCMethodDecl *method, + ObjCMethodDecl *prevMethod) { + // Merge the objc_requires_super attribute. + if (prevMethod->hasAttr<ObjCRequiresSuperAttr>() && + !method->hasAttr<ObjCRequiresSuperAttr>()) { + // merge the attribute into implementation. + method->addAttr( + ObjCRequiresSuperAttr::CreateImplicit(S.Context, + method->getLocation())); + } + + // Merge nullability of the result type. + QualType newReturnType + = mergeTypeNullabilityForRedecl( + S, method->getReturnTypeSourceRange().getBegin(), + method->getReturnType(), + method->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability, + prevMethod->getReturnTypeSourceRange().getBegin(), + prevMethod->getReturnType(), + prevMethod->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability); + method->setReturnType(newReturnType); + + // Handle each of the parameters. + unsigned numParams = method->param_size(); + unsigned numPrevParams = prevMethod->param_size(); + for (unsigned i = 0, n = std::min(numParams, numPrevParams); i != n; ++i) { + ParmVarDecl *param = method->param_begin()[i]; + ParmVarDecl *prevParam = prevMethod->param_begin()[i]; + + // Merge nullability. + QualType newParamType + = mergeTypeNullabilityForRedecl( + S, param->getLocation(), param->getType(), + param->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability, + prevParam->getLocation(), prevParam->getType(), + prevParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability); + param->setType(newParamType); + } +} + +/// Verify that the method parameters/return value have types that are supported +/// by the x86 target. +static void checkObjCMethodX86VectorTypes(Sema &SemaRef, + const ObjCMethodDecl *Method) { + assert(SemaRef.getASTContext().getTargetInfo().getTriple().getArch() == + llvm::Triple::x86 && + "x86-specific check invoked for a different target"); + SourceLocation Loc; + QualType T; + for (const ParmVarDecl *P : Method->parameters()) { + if (P->getType()->isVectorType()) { + Loc = P->getLocStart(); + T = P->getType(); + break; + } + } + if (Loc.isInvalid()) { + if (Method->getReturnType()->isVectorType()) { + Loc = Method->getReturnTypeSourceRange().getBegin(); + T = Method->getReturnType(); + } else + return; + } + + // Vector parameters/return values are not supported by objc_msgSend on x86 in + // iOS < 9 and macOS < 10.11. + const auto &Triple = SemaRef.getASTContext().getTargetInfo().getTriple(); + VersionTuple AcceptedInVersion; + if (Triple.getOS() == llvm::Triple::IOS) + AcceptedInVersion = VersionTuple(/*Major=*/9); + else if (Triple.isMacOSX()) + AcceptedInVersion = VersionTuple(/*Major=*/10, /*Minor=*/11); + else + return; + if (SemaRef.getASTContext().getTargetInfo().getPlatformMinVersion() >= + AcceptedInVersion) + return; + SemaRef.Diag(Loc, diag::err_objc_method_unsupported_param_ret_type) + << T << (Method->getReturnType()->isVectorType() ? /*return value*/ 1 + : /*parameter*/ 0) + << (Triple.isMacOSX() ? "macOS 10.11" : "iOS 9"); +} + +Decl *Sema::ActOnMethodDeclaration( + Scope *S, SourceLocation MethodLoc, SourceLocation EndLoc, + tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType, + ArrayRef<SourceLocation> SelectorLocs, Selector Sel, + // optional arguments. The number of types/arguments is obtained + // from the Sel.getNumArgs(). + ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo, + unsigned CNumArgs, // c-style args + const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodDeclKind, + bool isVariadic, bool MethodDefinition) { + // Make sure we can establish a context for the method. + if (!CurContext->isObjCContainer()) { + Diag(MethodLoc, diag::err_missing_method_context); + return nullptr; + } + Decl *ClassDecl = cast<ObjCContainerDecl>(CurContext); + QualType resultDeclType; + + bool HasRelatedResultType = false; + TypeSourceInfo *ReturnTInfo = nullptr; + if (ReturnType) { + resultDeclType = GetTypeFromParser(ReturnType, &ReturnTInfo); + + if (CheckFunctionReturnType(resultDeclType, MethodLoc)) + return nullptr; + + QualType bareResultType = resultDeclType; + (void)AttributedType::stripOuterNullability(bareResultType); + HasRelatedResultType = (bareResultType == Context.getObjCInstanceType()); + } else { // get the type for "id". + resultDeclType = Context.getObjCIdType(); + Diag(MethodLoc, diag::warn_missing_method_return_type) + << FixItHint::CreateInsertion(SelectorLocs.front(), "(id)"); + } + + ObjCMethodDecl *ObjCMethod = ObjCMethodDecl::Create( + Context, MethodLoc, EndLoc, Sel, resultDeclType, ReturnTInfo, CurContext, + MethodType == tok::minus, isVariadic, + /*isPropertyAccessor=*/false, + /*isImplicitlyDeclared=*/false, /*isDefined=*/false, + MethodDeclKind == tok::objc_optional ? ObjCMethodDecl::Optional + : ObjCMethodDecl::Required, + HasRelatedResultType); + + SmallVector<ParmVarDecl*, 16> Params; + + for (unsigned i = 0, e = Sel.getNumArgs(); i != e; ++i) { + QualType ArgType; + TypeSourceInfo *DI; + + if (!ArgInfo[i].Type) { + ArgType = Context.getObjCIdType(); + DI = nullptr; + } else { + ArgType = GetTypeFromParser(ArgInfo[i].Type, &DI); + } + + LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc, + LookupOrdinaryName, forRedeclarationInCurContext()); + LookupName(R, S); + if (R.isSingleResult()) { + NamedDecl *PrevDecl = R.getFoundDecl(); + if (S->isDeclScope(PrevDecl)) { + Diag(ArgInfo[i].NameLoc, + (MethodDefinition ? diag::warn_method_param_redefinition + : diag::warn_method_param_declaration)) + << ArgInfo[i].Name; + Diag(PrevDecl->getLocation(), + diag::note_previous_declaration); + } + } + + SourceLocation StartLoc = DI + ? DI->getTypeLoc().getBeginLoc() + : ArgInfo[i].NameLoc; + + ParmVarDecl* Param = CheckParameter(ObjCMethod, StartLoc, + ArgInfo[i].NameLoc, ArgInfo[i].Name, + ArgType, DI, SC_None); + + Param->setObjCMethodScopeInfo(i); + + Param->setObjCDeclQualifier( + CvtQTToAstBitMask(ArgInfo[i].DeclSpec.getObjCDeclQualifier())); + + // Apply the attributes to the parameter. + ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs); + AddPragmaAttributes(TUScope, Param); + + if (Param->hasAttr<BlocksAttr>()) { + Diag(Param->getLocation(), diag::err_block_on_nonlocal); + Param->setInvalidDecl(); + } + S->AddDecl(Param); + IdResolver.AddDecl(Param); + + Params.push_back(Param); + } + + for (unsigned i = 0, e = CNumArgs; i != e; ++i) { + ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param); + QualType ArgType = Param->getType(); + if (ArgType.isNull()) + ArgType = Context.getObjCIdType(); + else + // Perform the default array/function conversions (C99 6.7.5.3p[7,8]). + ArgType = Context.getAdjustedParameterType(ArgType); + + Param->setDeclContext(ObjCMethod); + Params.push_back(Param); + } + + ObjCMethod->setMethodParams(Context, Params, SelectorLocs); + ObjCMethod->setObjCDeclQualifier( + CvtQTToAstBitMask(ReturnQT.getObjCDeclQualifier())); + + ProcessDeclAttributeList(TUScope, ObjCMethod, AttrList); + AddPragmaAttributes(TUScope, ObjCMethod); + + // Add the method now. + const ObjCMethodDecl *PrevMethod = nullptr; + if (ObjCImplDecl *ImpDecl = dyn_cast<ObjCImplDecl>(ClassDecl)) { + if (MethodType == tok::minus) { + PrevMethod = ImpDecl->getInstanceMethod(Sel); + ImpDecl->addInstanceMethod(ObjCMethod); + } else { + PrevMethod = ImpDecl->getClassMethod(Sel); + ImpDecl->addClassMethod(ObjCMethod); + } + + // Merge information from the @interface declaration into the + // @implementation. + if (ObjCInterfaceDecl *IDecl = ImpDecl->getClassInterface()) { + if (auto *IMD = IDecl->lookupMethod(ObjCMethod->getSelector(), + ObjCMethod->isInstanceMethod())) { + mergeInterfaceMethodToImpl(*this, ObjCMethod, IMD); + + // Warn about defining -dealloc in a category. + if (isa<ObjCCategoryImplDecl>(ImpDecl) && IMD->isOverriding() && + ObjCMethod->getSelector().getMethodFamily() == OMF_dealloc) { + Diag(ObjCMethod->getLocation(), diag::warn_dealloc_in_category) + << ObjCMethod->getDeclName(); + } + } + + // Warn if a method declared in a protocol to which a category or + // extension conforms is non-escaping and the implementation's method is + // escaping. + for (auto *C : IDecl->visible_categories()) + for (auto &P : C->protocols()) + if (auto *IMD = P->lookupMethod(ObjCMethod->getSelector(), + ObjCMethod->isInstanceMethod())) { + assert(ObjCMethod->parameters().size() == + IMD->parameters().size() && + "Methods have different number of parameters"); + auto OI = IMD->param_begin(), OE = IMD->param_end(); + auto NI = ObjCMethod->param_begin(); + for (; OI != OE; ++OI, ++NI) + diagnoseNoescape(*NI, *OI, C, P, *this); + } + } + } else { + cast<DeclContext>(ClassDecl)->addDecl(ObjCMethod); + } + + if (PrevMethod) { + // You can never have two method definitions with the same name. + Diag(ObjCMethod->getLocation(), diag::err_duplicate_method_decl) + << ObjCMethod->getDeclName(); + Diag(PrevMethod->getLocation(), diag::note_previous_declaration); + ObjCMethod->setInvalidDecl(); + return ObjCMethod; + } + + // If this Objective-C method does not have a related result type, but we + // are allowed to infer related result types, try to do so based on the + // method family. + ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(ClassDecl); + if (!CurrentClass) { + if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(ClassDecl)) + CurrentClass = Cat->getClassInterface(); + else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(ClassDecl)) + CurrentClass = Impl->getClassInterface(); + else if (ObjCCategoryImplDecl *CatImpl + = dyn_cast<ObjCCategoryImplDecl>(ClassDecl)) + CurrentClass = CatImpl->getClassInterface(); + } + + ResultTypeCompatibilityKind RTC + = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass); + + CheckObjCMethodOverrides(ObjCMethod, CurrentClass, RTC); + + bool ARCError = false; + if (getLangOpts().ObjCAutoRefCount) + ARCError = CheckARCMethodDecl(ObjCMethod); + + // Infer the related result type when possible. + if (!ARCError && RTC == Sema::RTC_Compatible && + !ObjCMethod->hasRelatedResultType() && + LangOpts.ObjCInferRelatedResultType) { + bool InferRelatedResultType = false; + switch (ObjCMethod->getMethodFamily()) { + case OMF_None: + case OMF_copy: + case OMF_dealloc: + case OMF_finalize: + case OMF_mutableCopy: + case OMF_release: + case OMF_retainCount: + case OMF_initialize: + case OMF_performSelector: + break; + + case OMF_alloc: + case OMF_new: + InferRelatedResultType = ObjCMethod->isClassMethod(); + break; + + case OMF_init: + case OMF_autorelease: + case OMF_retain: + case OMF_self: + InferRelatedResultType = ObjCMethod->isInstanceMethod(); + break; + } + + if (InferRelatedResultType && + !ObjCMethod->getReturnType()->isObjCIndependentClassType()) + ObjCMethod->SetRelatedResultType(); + } + + if (MethodDefinition && + Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86) + checkObjCMethodX86VectorTypes(*this, ObjCMethod); + + // + load method cannot have availability attributes. It get called on + // startup, so it has to have the availability of the deployment target. + if (const auto *attr = ObjCMethod->getAttr<AvailabilityAttr>()) { + if (ObjCMethod->isClassMethod() && + ObjCMethod->getSelector().getAsString() == "load") { + Diag(attr->getLocation(), diag::warn_availability_on_static_initializer) + << 0; + ObjCMethod->dropAttr<AvailabilityAttr>(); + } + } + + ActOnDocumentableDecl(ObjCMethod); + + return ObjCMethod; +} + +bool Sema::CheckObjCDeclScope(Decl *D) { + // Following is also an error. But it is caused by a missing @end + // and diagnostic is issued elsewhere. + if (isa<ObjCContainerDecl>(CurContext->getRedeclContext())) + return false; + + // If we switched context to translation unit while we are still lexically in + // an objc container, it means the parser missed emitting an error. + if (isa<TranslationUnitDecl>(getCurLexicalContext()->getRedeclContext())) + return false; + + Diag(D->getLocation(), diag::err_objc_decls_may_only_appear_in_global_scope); + D->setInvalidDecl(); + + return true; +} + +/// Called whenever \@defs(ClassName) is encountered in the source. Inserts the +/// instance variables of ClassName into Decls. +void Sema::ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart, + IdentifierInfo *ClassName, + SmallVectorImpl<Decl*> &Decls) { + // Check that ClassName is a valid class + ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName, DeclStart); + if (!Class) { + Diag(DeclStart, diag::err_undef_interface) << ClassName; + return; + } + if (LangOpts.ObjCRuntime.isNonFragile()) { + Diag(DeclStart, diag::err_atdef_nonfragile_interface); + return; + } + + // Collect the instance variables + SmallVector<const ObjCIvarDecl*, 32> Ivars; + Context.DeepCollectObjCIvars(Class, true, Ivars); + // For each ivar, create a fresh ObjCAtDefsFieldDecl. + for (unsigned i = 0; i < Ivars.size(); i++) { + const FieldDecl* ID = Ivars[i]; + RecordDecl *Record = dyn_cast<RecordDecl>(TagD); + Decl *FD = ObjCAtDefsFieldDecl::Create(Context, Record, + /*FIXME: StartL=*/ID->getLocation(), + ID->getLocation(), + ID->getIdentifier(), ID->getType(), + ID->getBitWidth()); + Decls.push_back(FD); + } + + // Introduce all of these fields into the appropriate scope. + for (SmallVectorImpl<Decl*>::iterator D = Decls.begin(); + D != Decls.end(); ++D) { + FieldDecl *FD = cast<FieldDecl>(*D); + if (getLangOpts().CPlusPlus) + PushOnScopeChains(FD, S); + else if (RecordDecl *Record = dyn_cast<RecordDecl>(TagD)) + Record->addDecl(FD); + } +} + +/// Build a type-check a new Objective-C exception variable declaration. +VarDecl *Sema::BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType T, + SourceLocation StartLoc, + SourceLocation IdLoc, + IdentifierInfo *Id, + bool Invalid) { + // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage + // duration shall not be qualified by an address-space qualifier." + // Since all parameters have automatic store duration, they can not have + // an address space. + if (T.getAddressSpace() != LangAS::Default) { + Diag(IdLoc, diag::err_arg_with_address_space); + Invalid = true; + } + + // An @catch parameter must be an unqualified object pointer type; + // FIXME: Recover from "NSObject foo" by inserting the * in "NSObject *foo"? + if (Invalid) { + // Don't do any further checking. + } else if (T->isDependentType()) { + // Okay: we don't know what this type will instantiate to. + } else if (T->isObjCQualifiedIdType()) { + Invalid = true; + Diag(IdLoc, diag::err_illegal_qualifiers_on_catch_parm); + } else if (T->isObjCIdType()) { + // Okay: we don't know what this type will instantiate to. + } else if (!T->isObjCObjectPointerType()) { + Invalid = true; + Diag(IdLoc, diag::err_catch_param_not_objc_type); + } else if (!T->getAs<ObjCObjectPointerType>()->getInterfaceType()) { + Invalid = true; + Diag(IdLoc, diag::err_catch_param_not_objc_type); + } + + VarDecl *New = VarDecl::Create(Context, CurContext, StartLoc, IdLoc, Id, + T, TInfo, SC_None); + New->setExceptionVariable(true); + + // In ARC, infer 'retaining' for variables of retainable type. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(New)) + Invalid = true; + + if (Invalid) + New->setInvalidDecl(); + return New; +} + +Decl *Sema::ActOnObjCExceptionDecl(Scope *S, Declarator &D) { + const DeclSpec &DS = D.getDeclSpec(); + + // We allow the "register" storage class on exception variables because + // GCC did, but we drop it completely. Any other storage class is an error. + if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { + Diag(DS.getStorageClassSpecLoc(), diag::warn_register_objc_catch_parm) + << FixItHint::CreateRemoval(SourceRange(DS.getStorageClassSpecLoc())); + } else if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) { + Diag(DS.getStorageClassSpecLoc(), diag::err_storage_spec_on_catch_parm) + << DeclSpec::getSpecifierName(SCS); + } + if (DS.isInlineSpecified()) + Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function) + << getLangOpts().CPlusPlus17; + if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_invalid_thread) + << DeclSpec::getSpecifierName(TSCS); + D.getMutableDeclSpec().ClearStorageClassSpecs(); + + DiagnoseFunctionSpecifiers(D.getDeclSpec()); + + // Check that there are no default arguments inside the type of this + // exception object (C++ only). + if (getLangOpts().CPlusPlus) + CheckExtraCXXDefaultArguments(D); + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType ExceptionType = TInfo->getType(); + + VarDecl *New = BuildObjCExceptionDecl(TInfo, ExceptionType, + D.getSourceRange().getBegin(), + D.getIdentifierLoc(), + D.getIdentifier(), + D.isInvalidType()); + + // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). + if (D.getCXXScopeSpec().isSet()) { + Diag(D.getIdentifierLoc(), diag::err_qualified_objc_catch_parm) + << D.getCXXScopeSpec().getRange(); + New->setInvalidDecl(); + } + + // Add the parameter declaration into this scope. + S->AddDecl(New); + if (D.getIdentifier()) + IdResolver.AddDecl(New); + + ProcessDeclAttributes(S, New, D); + + if (New->hasAttr<BlocksAttr>()) + Diag(New->getLocation(), diag::err_block_on_nonlocal); + return New; +} + +/// CollectIvarsToConstructOrDestruct - Collect those ivars which require +/// initialization. +void Sema::CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI, + SmallVectorImpl<ObjCIvarDecl*> &Ivars) { + for (ObjCIvarDecl *Iv = OI->all_declared_ivar_begin(); Iv; + Iv= Iv->getNextIvar()) { + QualType QT = Context.getBaseElementType(Iv->getType()); + if (QT->isRecordType()) + Ivars.push_back(Iv); + } +} + +void Sema::DiagnoseUseOfUnimplementedSelectors() { + // Load referenced selectors from the external source. + if (ExternalSource) { + SmallVector<std::pair<Selector, SourceLocation>, 4> Sels; + ExternalSource->ReadReferencedSelectors(Sels); + for (unsigned I = 0, N = Sels.size(); I != N; ++I) + ReferencedSelectors[Sels[I].first] = Sels[I].second; + } + + // Warning will be issued only when selector table is + // generated (which means there is at lease one implementation + // in the TU). This is to match gcc's behavior. + if (ReferencedSelectors.empty() || + !Context.AnyObjCImplementation()) + return; + for (auto &SelectorAndLocation : ReferencedSelectors) { + Selector Sel = SelectorAndLocation.first; + SourceLocation Loc = SelectorAndLocation.second; + if (!LookupImplementedMethodInGlobalPool(Sel)) + Diag(Loc, diag::warn_unimplemented_selector) << Sel; + } +} + +ObjCIvarDecl * +Sema::GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method, + const ObjCPropertyDecl *&PDecl) const { + if (Method->isClassMethod()) + return nullptr; + const ObjCInterfaceDecl *IDecl = Method->getClassInterface(); + if (!IDecl) + return nullptr; + Method = IDecl->lookupMethod(Method->getSelector(), /*isInstance=*/true, + /*shallowCategoryLookup=*/false, + /*followSuper=*/false); + if (!Method || !Method->isPropertyAccessor()) + return nullptr; + if ((PDecl = Method->findPropertyDecl())) + if (ObjCIvarDecl *IV = PDecl->getPropertyIvarDecl()) { + // property backing ivar must belong to property's class + // or be a private ivar in class's implementation. + // FIXME. fix the const-ness issue. + IV = const_cast<ObjCInterfaceDecl *>(IDecl)->lookupInstanceVariable( + IV->getIdentifier()); + return IV; + } + return nullptr; +} + +namespace { + /// Used by Sema::DiagnoseUnusedBackingIvarInAccessor to check if a property + /// accessor references the backing ivar. + class UnusedBackingIvarChecker : + public RecursiveASTVisitor<UnusedBackingIvarChecker> { + public: + Sema &S; + const ObjCMethodDecl *Method; + const ObjCIvarDecl *IvarD; + bool AccessedIvar; + bool InvokedSelfMethod; + + UnusedBackingIvarChecker(Sema &S, const ObjCMethodDecl *Method, + const ObjCIvarDecl *IvarD) + : S(S), Method(Method), IvarD(IvarD), + AccessedIvar(false), InvokedSelfMethod(false) { + assert(IvarD); + } + + bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { + if (E->getDecl() == IvarD) { + AccessedIvar = true; + return false; + } + return true; + } + + bool VisitObjCMessageExpr(ObjCMessageExpr *E) { + if (E->getReceiverKind() == ObjCMessageExpr::Instance && + S.isSelfExpr(E->getInstanceReceiver(), Method)) { + InvokedSelfMethod = true; + } + return true; + } + }; +} // end anonymous namespace + +void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S, + const ObjCImplementationDecl *ImplD) { + if (S->hasUnrecoverableErrorOccurred()) + return; + + for (const auto *CurMethod : ImplD->instance_methods()) { + unsigned DIAG = diag::warn_unused_property_backing_ivar; + SourceLocation Loc = CurMethod->getLocation(); + if (Diags.isIgnored(DIAG, Loc)) + continue; + + const ObjCPropertyDecl *PDecl; + const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl); + if (!IV) + continue; + + UnusedBackingIvarChecker Checker(*this, CurMethod, IV); + Checker.TraverseStmt(CurMethod->getBody()); + if (Checker.AccessedIvar) + continue; + + // Do not issue this warning if backing ivar is used somewhere and accessor + // implementation makes a self call. This is to prevent false positive in + // cases where the ivar is accessed by another method that the accessor + // delegates to. + if (!IV->isReferenced() || !Checker.InvokedSelfMethod) { + Diag(Loc, DIAG) << IV; + Diag(PDecl->getLocation(), diag::note_property_declare); + } + } +} |