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Current File : //compat/linux/proc/68247/root/usr/src/contrib/llvm/tools/clang/lib/Sema/SemaExprMember.cpp |
//===--- SemaExprMember.cpp - Semantic Analysis for Expressions -----------===// // // 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 member access expressions. // //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/Scope.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/ExprObjC.h" #include "clang/Lex/Preprocessor.h" using namespace clang; using namespace sema; /// Determines if the given class is provably not derived from all of /// the prospective base classes. static bool IsProvablyNotDerivedFrom(Sema &SemaRef, CXXRecordDecl *Record, const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { if (Bases.count(Record->getCanonicalDecl())) return false; RecordDecl *RD = Record->getDefinition(); if (!RD) return false; Record = cast<CXXRecordDecl>(RD); for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), E = Record->bases_end(); I != E; ++I) { CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); if (!BaseRT) return false; CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) return false; } return true; } enum IMAKind { /// The reference is definitely not an instance member access. IMA_Static, /// The reference may be an implicit instance member access. IMA_Mixed, /// The reference may be to an instance member, but it might be invalid if /// so, because the context is not an instance method. IMA_Mixed_StaticContext, /// The reference may be to an instance member, but it is invalid if /// so, because the context is from an unrelated class. IMA_Mixed_Unrelated, /// The reference is definitely an implicit instance member access. IMA_Instance, /// The reference may be to an unresolved using declaration. IMA_Unresolved, /// The reference may be to an unresolved using declaration and the /// context is not an instance method. IMA_Unresolved_StaticContext, // The reference refers to a field which is not a member of the containing // class, which is allowed because we're in C++11 mode and the context is // unevaluated. IMA_Field_Uneval_Context, /// All possible referrents are instance members and the current /// context is not an instance method. IMA_Error_StaticContext, /// All possible referrents are instance members of an unrelated /// class. IMA_Error_Unrelated }; /// The given lookup names class member(s) and is not being used for /// an address-of-member expression. Classify the type of access /// according to whether it's possible that this reference names an /// instance member. This is best-effort in dependent contexts; it is okay to /// conservatively answer "yes", in which case some errors will simply /// not be caught until template-instantiation. static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, Scope *CurScope, const LookupResult &R) { assert(!R.empty() && (*R.begin())->isCXXClassMember()); DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); bool isStaticContext = SemaRef.CXXThisTypeOverride.isNull() && (!isa<CXXMethodDecl>(DC) || cast<CXXMethodDecl>(DC)->isStatic()); if (R.isUnresolvableResult()) return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; // Collect all the declaring classes of instance members we find. bool hasNonInstance = false; bool isField = false; llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { NamedDecl *D = *I; if (D->isCXXInstanceMember()) { if (dyn_cast<FieldDecl>(D)) isField = true; CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); Classes.insert(R->getCanonicalDecl()); } else hasNonInstance = true; } // If we didn't find any instance members, it can't be an implicit // member reference. if (Classes.empty()) return IMA_Static; bool IsCXX11UnevaluatedField = false; if (SemaRef.getLangOpts().CPlusPlus0x && isField) { // C++11 [expr.prim.general]p12: // An id-expression that denotes a non-static data member or non-static // member function of a class can only be used: // (...) // - if that id-expression denotes a non-static data member and it // appears in an unevaluated operand. const Sema::ExpressionEvaluationContextRecord& record = SemaRef.ExprEvalContexts.back(); if (record.Context == Sema::Unevaluated) IsCXX11UnevaluatedField = true; } // If the current context is not an instance method, it can't be // an implicit member reference. if (isStaticContext) { if (hasNonInstance) return IMA_Mixed_StaticContext; return IsCXX11UnevaluatedField ? IMA_Field_Uneval_Context : IMA_Error_StaticContext; } CXXRecordDecl *contextClass; if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) contextClass = MD->getParent()->getCanonicalDecl(); else contextClass = cast<CXXRecordDecl>(DC); // [class.mfct.non-static]p3: // ...is used in the body of a non-static member function of class X, // if name lookup (3.4.1) resolves the name in the id-expression to a // non-static non-type member of some class C [...] // ...if C is not X or a base class of X, the class member access expression // is ill-formed. if (R.getNamingClass() && contextClass->getCanonicalDecl() != R.getNamingClass()->getCanonicalDecl() && contextClass->isProvablyNotDerivedFrom(R.getNamingClass())) return hasNonInstance ? IMA_Mixed_Unrelated : IsCXX11UnevaluatedField ? IMA_Field_Uneval_Context : IMA_Error_Unrelated; // If we can prove that the current context is unrelated to all the // declaring classes, it can't be an implicit member reference (in // which case it's an error if any of those members are selected). if (IsProvablyNotDerivedFrom(SemaRef, contextClass, Classes)) return hasNonInstance ? IMA_Mixed_Unrelated : IsCXX11UnevaluatedField ? IMA_Field_Uneval_Context : IMA_Error_Unrelated; return (hasNonInstance ? IMA_Mixed : IMA_Instance); } /// Diagnose a reference to a field with no object available. static void diagnoseInstanceReference(Sema &SemaRef, const CXXScopeSpec &SS, NamedDecl *Rep, const DeclarationNameInfo &nameInfo) { SourceLocation Loc = nameInfo.getLoc(); SourceRange Range(Loc); if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); DeclContext *FunctionLevelDC = SemaRef.getFunctionLevelDeclContext(); CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FunctionLevelDC); CXXRecordDecl *ContextClass = Method ? Method->getParent() : 0; CXXRecordDecl *RepClass = dyn_cast<CXXRecordDecl>(Rep->getDeclContext()); bool InStaticMethod = Method && Method->isStatic(); bool IsField = isa<FieldDecl>(Rep) || isa<IndirectFieldDecl>(Rep); if (IsField && InStaticMethod) // "invalid use of member 'x' in static member function" SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) << Range << nameInfo.getName(); else if (ContextClass && RepClass && SS.isEmpty() && !InStaticMethod && !RepClass->Equals(ContextClass) && RepClass->Encloses(ContextClass)) // Unqualified lookup in a non-static member function found a member of an // enclosing class. SemaRef.Diag(Loc, diag::err_nested_non_static_member_use) << IsField << RepClass << nameInfo.getName() << ContextClass << Range; else if (IsField) SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) << nameInfo.getName() << Range; else SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; } /// Builds an expression which might be an implicit member expression. ExprResult Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R, const TemplateArgumentListInfo *TemplateArgs) { switch (ClassifyImplicitMemberAccess(*this, CurScope, R)) { case IMA_Instance: return BuildImplicitMemberExpr(SS, TemplateKWLoc, R, TemplateArgs, true); case IMA_Mixed: case IMA_Mixed_Unrelated: case IMA_Unresolved: return BuildImplicitMemberExpr(SS, TemplateKWLoc, R, TemplateArgs, false); case IMA_Field_Uneval_Context: Diag(R.getNameLoc(), diag::warn_cxx98_compat_non_static_member_use) << R.getLookupNameInfo().getName(); // Fall through. case IMA_Static: case IMA_Mixed_StaticContext: case IMA_Unresolved_StaticContext: if (TemplateArgs || TemplateKWLoc.isValid()) return BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, TemplateArgs); return BuildDeclarationNameExpr(SS, R, false); case IMA_Error_StaticContext: case IMA_Error_Unrelated: diagnoseInstanceReference(*this, SS, R.getRepresentativeDecl(), R.getLookupNameInfo()); return ExprError(); } llvm_unreachable("unexpected instance member access kind"); } /// Check an ext-vector component access expression. /// /// VK should be set in advance to the value kind of the base /// expression. static QualType CheckExtVectorComponent(Sema &S, QualType baseType, ExprValueKind &VK, SourceLocation OpLoc, const IdentifierInfo *CompName, SourceLocation CompLoc) { // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, // see FIXME there. // // FIXME: This logic can be greatly simplified by splitting it along // halving/not halving and reworking the component checking. const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); // The vector accessor can't exceed the number of elements. const char *compStr = CompName->getNameStart(); // This flag determines whether or not the component is one of the four // special names that indicate a subset of exactly half the elements are // to be selected. bool HalvingSwizzle = false; // This flag determines whether or not CompName has an 's' char prefix, // indicating that it is a string of hex values to be used as vector indices. bool HexSwizzle = *compStr == 's' || *compStr == 'S'; bool HasRepeated = false; bool HasIndex[16] = {}; int Idx; // Check that we've found one of the special components, or that the component // names must come from the same set. if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { HalvingSwizzle = true; } else if (!HexSwizzle && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1) { do { if (HasIndex[Idx]) HasRepeated = true; HasIndex[Idx] = true; compStr++; } while (*compStr && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1); } else { if (HexSwizzle) compStr++; while ((Idx = vecType->getNumericAccessorIdx(*compStr)) != -1) { if (HasIndex[Idx]) HasRepeated = true; HasIndex[Idx] = true; compStr++; } } if (!HalvingSwizzle && *compStr) { // We didn't get to the end of the string. This means the component names // didn't come from the same set *or* we encountered an illegal name. S.Diag(OpLoc, diag::err_ext_vector_component_name_illegal) << StringRef(compStr, 1) << SourceRange(CompLoc); return QualType(); } // Ensure no component accessor exceeds the width of the vector type it // operates on. if (!HalvingSwizzle) { compStr = CompName->getNameStart(); if (HexSwizzle) compStr++; while (*compStr) { if (!vecType->isAccessorWithinNumElements(*compStr++)) { S.Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) << baseType << SourceRange(CompLoc); return QualType(); } } } // The component accessor looks fine - now we need to compute the actual type. // The vector type is implied by the component accessor. For example, // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. // vec4.s0 is a float, vec4.s23 is a vec3, etc. // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 : CompName->getLength(); if (HexSwizzle) CompSize--; if (CompSize == 1) return vecType->getElementType(); if (HasRepeated) VK = VK_RValue; QualType VT = S.Context.getExtVectorType(vecType->getElementType(), CompSize); // Now look up the TypeDefDecl from the vector type. Without this, // diagostics look bad. We want extended vector types to appear built-in. for (Sema::ExtVectorDeclsType::iterator I = S.ExtVectorDecls.begin(S.ExternalSource), E = S.ExtVectorDecls.end(); I != E; ++I) { if ((*I)->getUnderlyingType() == VT) return S.Context.getTypedefType(*I); } return VT; // should never get here (a typedef type should always be found). } static Decl *FindGetterSetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, IdentifierInfo *Member, const Selector &Sel, ASTContext &Context) { if (Member) if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) return PD; if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) return OMD; for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), E = PDecl->protocol_end(); I != E; ++I) { if (Decl *D = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, Context)) return D; } return 0; } static Decl *FindGetterSetterNameDecl(const ObjCObjectPointerType *QIdTy, IdentifierInfo *Member, const Selector &Sel, ASTContext &Context) { // Check protocols on qualified interfaces. Decl *GDecl = 0; for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), E = QIdTy->qual_end(); I != E; ++I) { if (Member) if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { GDecl = PD; break; } // Also must look for a getter or setter name which uses property syntax. if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { GDecl = OMD; break; } } if (!GDecl) { for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), E = QIdTy->qual_end(); I != E; ++I) { // Search in the protocol-qualifier list of current protocol. GDecl = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, Context); if (GDecl) return GDecl; } } return GDecl; } ExprResult Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, bool IsArrow, SourceLocation OpLoc, const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *TemplateArgs) { // Even in dependent contexts, try to diagnose base expressions with // obviously wrong types, e.g.: // // T* t; // t.f; // // In Obj-C++, however, the above expression is valid, since it could be // accessing the 'f' property if T is an Obj-C interface. The extra check // allows this, while still reporting an error if T is a struct pointer. if (!IsArrow) { const PointerType *PT = BaseType->getAs<PointerType>(); if (PT && (!getLangOpts().ObjC1 || PT->getPointeeType()->isRecordType())) { assert(BaseExpr && "cannot happen with implicit member accesses"); Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) << BaseType << BaseExpr->getSourceRange(); return ExprError(); } } assert(BaseType->isDependentType() || NameInfo.getName().isDependentName() || isDependentScopeSpecifier(SS)); // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr // must have pointer type, and the accessed type is the pointee. return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, IsArrow, OpLoc, SS.getWithLocInContext(Context), TemplateKWLoc, FirstQualifierInScope, NameInfo, TemplateArgs)); } /// We know that the given qualified member reference points only to /// declarations which do not belong to the static type of the base /// expression. Diagnose the problem. static void DiagnoseQualifiedMemberReference(Sema &SemaRef, Expr *BaseExpr, QualType BaseType, const CXXScopeSpec &SS, NamedDecl *rep, const DeclarationNameInfo &nameInfo) { // If this is an implicit member access, use a different set of // diagnostics. if (!BaseExpr) return diagnoseInstanceReference(SemaRef, SS, rep, nameInfo); SemaRef.Diag(nameInfo.getLoc(), diag::err_qualified_member_of_unrelated) << SS.getRange() << rep << BaseType; } // Check whether the declarations we found through a nested-name // specifier in a member expression are actually members of the base // type. The restriction here is: // // C++ [expr.ref]p2: // ... In these cases, the id-expression shall name a // member of the class or of one of its base classes. // // So it's perfectly legitimate for the nested-name specifier to name // an unrelated class, and for us to find an overload set including // decls from classes which are not superclasses, as long as the decl // we actually pick through overload resolution is from a superclass. bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, QualType BaseType, const CXXScopeSpec &SS, const LookupResult &R) { const RecordType *BaseRT = BaseType->getAs<RecordType>(); if (!BaseRT) { // We can't check this yet because the base type is still // dependent. assert(BaseType->isDependentType()); return false; } CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { // If this is an implicit member reference and we find a // non-instance member, it's not an error. if (!BaseExpr && !(*I)->isCXXInstanceMember()) return false; // Note that we use the DC of the decl, not the underlying decl. DeclContext *DC = (*I)->getDeclContext(); while (DC->isTransparentContext()) DC = DC->getParent(); if (!DC->isRecord()) continue; llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) return false; } DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R.getRepresentativeDecl(), R.getLookupNameInfo()); return true; } namespace { // Callback to only accept typo corrections that are either a ValueDecl or a // FunctionTemplateDecl. class RecordMemberExprValidatorCCC : public CorrectionCandidateCallback { public: virtual bool ValidateCandidate(const TypoCorrection &candidate) { NamedDecl *ND = candidate.getCorrectionDecl(); return ND && (isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)); } }; } static bool LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, SourceRange BaseRange, const RecordType *RTy, SourceLocation OpLoc, CXXScopeSpec &SS, bool HasTemplateArgs) { RecordDecl *RDecl = RTy->getDecl(); if (!SemaRef.isThisOutsideMemberFunctionBody(QualType(RTy, 0)) && SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), SemaRef.PDiag(diag::err_typecheck_incomplete_tag) << BaseRange)) return true; if (HasTemplateArgs) { // LookupTemplateName doesn't expect these both to exist simultaneously. QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); bool MOUS; SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); return false; } DeclContext *DC = RDecl; if (SS.isSet()) { // If the member name was a qualified-id, look into the // nested-name-specifier. DC = SemaRef.computeDeclContext(SS, false); if (SemaRef.RequireCompleteDeclContext(SS, DC)) { SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) << SS.getRange() << DC; return true; } assert(DC && "Cannot handle non-computable dependent contexts in lookup"); if (!isa<TypeDecl>(DC)) { SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) << DC << SS.getRange(); return true; } } // The record definition is complete, now look up the member. SemaRef.LookupQualifiedName(R, DC); if (!R.empty()) return false; // We didn't find anything with the given name, so try to correct // for typos. DeclarationName Name = R.getLookupName(); RecordMemberExprValidatorCCC Validator; TypoCorrection Corrected = SemaRef.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), NULL, &SS, Validator, DC); R.clear(); if (NamedDecl *ND = Corrected.getCorrectionDecl()) { std::string CorrectedStr( Corrected.getAsString(SemaRef.getLangOpts())); std::string CorrectedQuotedStr( Corrected.getQuoted(SemaRef.getLangOpts())); R.setLookupName(Corrected.getCorrection()); R.addDecl(ND); SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) << Name << DC << CorrectedQuotedStr << SS.getRange() << FixItHint::CreateReplacement(R.getNameLoc(), CorrectedStr); SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) << ND->getDeclName(); } return false; } ExprResult Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, SourceLocation OpLoc, bool IsArrow, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *TemplateArgs) { if (BaseType->isDependentType() || (SS.isSet() && isDependentScopeSpecifier(SS))) return ActOnDependentMemberExpr(Base, BaseType, IsArrow, OpLoc, SS, TemplateKWLoc, FirstQualifierInScope, NameInfo, TemplateArgs); LookupResult R(*this, NameInfo, LookupMemberName); // Implicit member accesses. if (!Base) { QualType RecordTy = BaseType; if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); if (LookupMemberExprInRecord(*this, R, SourceRange(), RecordTy->getAs<RecordType>(), OpLoc, SS, TemplateArgs != 0)) return ExprError(); // Explicit member accesses. } else { ExprResult BaseResult = Owned(Base); ExprResult Result = LookupMemberExpr(R, BaseResult, IsArrow, OpLoc, SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); if (BaseResult.isInvalid()) return ExprError(); Base = BaseResult.take(); if (Result.isInvalid()) { Owned(Base); return ExprError(); } if (Result.get()) return move(Result); // LookupMemberExpr can modify Base, and thus change BaseType BaseType = Base->getType(); } return BuildMemberReferenceExpr(Base, BaseType, OpLoc, IsArrow, SS, TemplateKWLoc, FirstQualifierInScope, R, TemplateArgs); } static ExprResult BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, const CXXScopeSpec &SS, FieldDecl *Field, DeclAccessPair FoundDecl, const DeclarationNameInfo &MemberNameInfo); ExprResult Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS, SourceLocation loc, IndirectFieldDecl *indirectField, Expr *baseObjectExpr, SourceLocation opLoc) { // First, build the expression that refers to the base object. bool baseObjectIsPointer = false; Qualifiers baseQuals; // Case 1: the base of the indirect field is not a field. VarDecl *baseVariable = indirectField->getVarDecl(); CXXScopeSpec EmptySS; if (baseVariable) { assert(baseVariable->getType()->isRecordType()); // In principle we could have a member access expression that // accesses an anonymous struct/union that's a static member of // the base object's class. However, under the current standard, // static data members cannot be anonymous structs or unions. // Supporting this is as easy as building a MemberExpr here. assert(!baseObjectExpr && "anonymous struct/union is static data member?"); DeclarationNameInfo baseNameInfo(DeclarationName(), loc); ExprResult result = BuildDeclarationNameExpr(EmptySS, baseNameInfo, baseVariable); if (result.isInvalid()) return ExprError(); baseObjectExpr = result.take(); baseObjectIsPointer = false; baseQuals = baseObjectExpr->getType().getQualifiers(); // Case 2: the base of the indirect field is a field and the user // wrote a member expression. } else if (baseObjectExpr) { // The caller provided the base object expression. Determine // whether its a pointer and whether it adds any qualifiers to the // anonymous struct/union fields we're looking into. QualType objectType = baseObjectExpr->getType(); if (const PointerType *ptr = objectType->getAs<PointerType>()) { baseObjectIsPointer = true; objectType = ptr->getPointeeType(); } else { baseObjectIsPointer = false; } baseQuals = objectType.getQualifiers(); // Case 3: the base of the indirect field is a field and we should // build an implicit member access. } else { // We've found a member of an anonymous struct/union that is // inside a non-anonymous struct/union, so in a well-formed // program our base object expression is "this". QualType ThisTy = getCurrentThisType(); if (ThisTy.isNull()) { Diag(loc, diag::err_invalid_member_use_in_static_method) << indirectField->getDeclName(); return ExprError(); } // Our base object expression is "this". CheckCXXThisCapture(loc); baseObjectExpr = new (Context) CXXThisExpr(loc, ThisTy, /*isImplicit=*/ true); baseObjectIsPointer = true; baseQuals = ThisTy->castAs<PointerType>()->getPointeeType().getQualifiers(); } // Build the implicit member references to the field of the // anonymous struct/union. Expr *result = baseObjectExpr; IndirectFieldDecl::chain_iterator FI = indirectField->chain_begin(), FEnd = indirectField->chain_end(); // Build the first member access in the chain with full information. if (!baseVariable) { FieldDecl *field = cast<FieldDecl>(*FI); // FIXME: use the real found-decl info! DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess()); // Make a nameInfo that properly uses the anonymous name. DeclarationNameInfo memberNameInfo(field->getDeclName(), loc); result = BuildFieldReferenceExpr(*this, result, baseObjectIsPointer, EmptySS, field, foundDecl, memberNameInfo).take(); baseObjectIsPointer = false; // FIXME: check qualified member access } // In all cases, we should now skip the first declaration in the chain. ++FI; while (FI != FEnd) { FieldDecl *field = cast<FieldDecl>(*FI++); // FIXME: these are somewhat meaningless DeclarationNameInfo memberNameInfo(field->getDeclName(), loc); DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess()); result = BuildFieldReferenceExpr(*this, result, /*isarrow*/ false, (FI == FEnd? SS : EmptySS), field, foundDecl, memberNameInfo).take(); } return Owned(result); } /// \brief Build a MemberExpr AST node. static MemberExpr *BuildMemberExpr(Sema &SemaRef, ASTContext &C, Expr *Base, bool isArrow, const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, ValueDecl *Member, DeclAccessPair FoundDecl, const DeclarationNameInfo &MemberNameInfo, QualType Ty, ExprValueKind VK, ExprObjectKind OK, const TemplateArgumentListInfo *TemplateArgs = 0) { assert((!isArrow || Base->isRValue()) && "-> base must be a pointer rvalue"); MemberExpr *E = MemberExpr::Create(C, Base, isArrow, SS.getWithLocInContext(C), TemplateKWLoc, Member, FoundDecl, MemberNameInfo, TemplateArgs, Ty, VK, OK); SemaRef.MarkMemberReferenced(E); return E; } ExprResult Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, SourceLocation OpLoc, bool IsArrow, const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierInScope, LookupResult &R, const TemplateArgumentListInfo *TemplateArgs, bool SuppressQualifierCheck) { QualType BaseType = BaseExprType; if (IsArrow) { assert(BaseType->isPointerType()); BaseType = BaseType->castAs<PointerType>()->getPointeeType(); } R.setBaseObjectType(BaseType); const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); DeclarationName MemberName = MemberNameInfo.getName(); SourceLocation MemberLoc = MemberNameInfo.getLoc(); if (R.isAmbiguous()) return ExprError(); if (R.empty()) { // Rederive where we looked up. DeclContext *DC = (SS.isSet() ? computeDeclContext(SS, false) : BaseType->getAs<RecordType>()->getDecl()); Diag(R.getNameLoc(), diag::err_no_member) << MemberName << DC << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); return ExprError(); } // Diagnose lookups that find only declarations from a non-base // type. This is possible for either qualified lookups (which may // have been qualified with an unrelated type) or implicit member // expressions (which were found with unqualified lookup and thus // may have come from an enclosing scope). Note that it's okay for // lookup to find declarations from a non-base type as long as those // aren't the ones picked by overload resolution. if ((SS.isSet() || !BaseExpr || (isa<CXXThisExpr>(BaseExpr) && cast<CXXThisExpr>(BaseExpr)->isImplicit())) && !SuppressQualifierCheck && CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) return ExprError(); // Construct an unresolved result if we in fact got an unresolved // result. if (R.isOverloadedResult() || R.isUnresolvableResult()) { // Suppress any lookup-related diagnostics; we'll do these when we // pick a member. R.suppressDiagnostics(); UnresolvedMemberExpr *MemExpr = UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(), BaseExpr, BaseExprType, IsArrow, OpLoc, SS.getWithLocInContext(Context), TemplateKWLoc, MemberNameInfo, TemplateArgs, R.begin(), R.end()); return Owned(MemExpr); } assert(R.isSingleResult()); DeclAccessPair FoundDecl = R.begin().getPair(); NamedDecl *MemberDecl = R.getFoundDecl(); // FIXME: diagnose the presence of template arguments now. // If the decl being referenced had an error, return an error for this // sub-expr without emitting another error, in order to avoid cascading // error cases. if (MemberDecl->isInvalidDecl()) return ExprError(); // Handle the implicit-member-access case. if (!BaseExpr) { // If this is not an instance member, convert to a non-member access. if (!MemberDecl->isCXXInstanceMember()) return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); SourceLocation Loc = R.getNameLoc(); if (SS.getRange().isValid()) Loc = SS.getRange().getBegin(); CheckCXXThisCapture(Loc); BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); } bool ShouldCheckUse = true; if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { // Don't diagnose the use of a virtual member function unless it's // explicitly qualified. if (MD->isVirtual() && !SS.isSet()) ShouldCheckUse = false; } // Check the use of this member. if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { Owned(BaseExpr); return ExprError(); } if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) return BuildFieldReferenceExpr(*this, BaseExpr, IsArrow, SS, FD, FoundDecl, MemberNameInfo); if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(MemberDecl)) // We may have found a field within an anonymous union or struct // (C++ [class.union]). return BuildAnonymousStructUnionMemberReference(SS, MemberLoc, FD, BaseExpr, OpLoc); if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { return Owned(BuildMemberExpr(*this, Context, BaseExpr, IsArrow, SS, TemplateKWLoc, Var, FoundDecl, MemberNameInfo, Var->getType().getNonReferenceType(), VK_LValue, OK_Ordinary)); } if (CXXMethodDecl *MemberFn = dyn_cast<CXXMethodDecl>(MemberDecl)) { ExprValueKind valueKind; QualType type; if (MemberFn->isInstance()) { valueKind = VK_RValue; type = Context.BoundMemberTy; } else { valueKind = VK_LValue; type = MemberFn->getType(); } return Owned(BuildMemberExpr(*this, Context, BaseExpr, IsArrow, SS, TemplateKWLoc, MemberFn, FoundDecl, MemberNameInfo, type, valueKind, OK_Ordinary)); } assert(!isa<FunctionDecl>(MemberDecl) && "member function not C++ method?"); if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { return Owned(BuildMemberExpr(*this, Context, BaseExpr, IsArrow, SS, TemplateKWLoc, Enum, FoundDecl, MemberNameInfo, Enum->getType(), VK_RValue, OK_Ordinary)); } Owned(BaseExpr); // We found something that we didn't expect. Complain. if (isa<TypeDecl>(MemberDecl)) Diag(MemberLoc, diag::err_typecheck_member_reference_type) << MemberName << BaseType << int(IsArrow); else Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) << MemberName << BaseType << int(IsArrow); Diag(MemberDecl->getLocation(), diag::note_member_declared_here) << MemberName; R.suppressDiagnostics(); return ExprError(); } /// Given that normal member access failed on the given expression, /// and given that the expression's type involves builtin-id or /// builtin-Class, decide whether substituting in the redefinition /// types would be profitable. The redefinition type is whatever /// this translation unit tried to typedef to id/Class; we store /// it to the side and then re-use it in places like this. static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) { const ObjCObjectPointerType *opty = base.get()->getType()->getAs<ObjCObjectPointerType>(); if (!opty) return false; const ObjCObjectType *ty = opty->getObjectType(); QualType redef; if (ty->isObjCId()) { redef = S.Context.getObjCIdRedefinitionType(); } else if (ty->isObjCClass()) { redef = S.Context.getObjCClassRedefinitionType(); } else { return false; } // Do the substitution as long as the redefinition type isn't just a // possibly-qualified pointer to builtin-id or builtin-Class again. opty = redef->getAs<ObjCObjectPointerType>(); if (opty && !opty->getObjectType()->getInterface() != 0) return false; base = S.ImpCastExprToType(base.take(), redef, CK_BitCast); return true; } static bool isRecordType(QualType T) { return T->isRecordType(); } static bool isPointerToRecordType(QualType T) { if (const PointerType *PT = T->getAs<PointerType>()) return PT->getPointeeType()->isRecordType(); return false; } /// Perform conversions on the LHS of a member access expression. ExprResult Sema::PerformMemberExprBaseConversion(Expr *Base, bool IsArrow) { if (IsArrow && !Base->getType()->isFunctionType()) return DefaultFunctionArrayLvalueConversion(Base); return CheckPlaceholderExpr(Base); } /// Look up the given member of the given non-type-dependent /// expression. This can return in one of two ways: /// * If it returns a sentinel null-but-valid result, the caller will /// assume that lookup was performed and the results written into /// the provided structure. It will take over from there. /// * Otherwise, the returned expression will be produced in place of /// an ordinary member expression. /// /// The ObjCImpDecl bit is a gross hack that will need to be properly /// fixed for ObjC++. ExprResult Sema::LookupMemberExpr(LookupResult &R, ExprResult &BaseExpr, bool &IsArrow, SourceLocation OpLoc, CXXScopeSpec &SS, Decl *ObjCImpDecl, bool HasTemplateArgs) { assert(BaseExpr.get() && "no base expression"); // Perform default conversions. BaseExpr = PerformMemberExprBaseConversion(BaseExpr.take(), IsArrow); if (BaseExpr.isInvalid()) return ExprError(); QualType BaseType = BaseExpr.get()->getType(); assert(!BaseType->isDependentType()); DeclarationName MemberName = R.getLookupName(); SourceLocation MemberLoc = R.getNameLoc(); // For later type-checking purposes, turn arrow accesses into dot // accesses. The only access type we support that doesn't follow // the C equivalence "a->b === (*a).b" is ObjC property accesses, // and those never use arrows, so this is unaffected. if (IsArrow) { if (const PointerType *Ptr = BaseType->getAs<PointerType>()) BaseType = Ptr->getPointeeType(); else if (const ObjCObjectPointerType *Ptr = BaseType->getAs<ObjCObjectPointerType>()) BaseType = Ptr->getPointeeType(); else if (BaseType->isRecordType()) { // Recover from arrow accesses to records, e.g.: // struct MyRecord foo; // foo->bar // This is actually well-formed in C++ if MyRecord has an // overloaded operator->, but that should have been dealt with // by now. Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange() << FixItHint::CreateReplacement(OpLoc, "."); IsArrow = false; } else if (BaseType->isFunctionType()) { goto fail; } else { Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) << BaseType << BaseExpr.get()->getSourceRange(); return ExprError(); } } // Handle field access to simple records. if (const RecordType *RTy = BaseType->getAs<RecordType>()) { if (LookupMemberExprInRecord(*this, R, BaseExpr.get()->getSourceRange(), RTy, OpLoc, SS, HasTemplateArgs)) return ExprError(); // Returning valid-but-null is how we indicate to the caller that // the lookup result was filled in. return Owned((Expr*) 0); } // Handle ivar access to Objective-C objects. if (const ObjCObjectType *OTy = BaseType->getAs<ObjCObjectType>()) { if (!SS.isEmpty() && !SS.isInvalid()) { Diag(SS.getRange().getBegin(), diag::err_qualified_objc_access) << 1 << SS.getScopeRep() << FixItHint::CreateRemoval(SS.getRange()); SS.clear(); } IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); // There are three cases for the base type: // - builtin id (qualified or unqualified) // - builtin Class (qualified or unqualified) // - an interface ObjCInterfaceDecl *IDecl = OTy->getInterface(); if (!IDecl) { if (getLangOpts().ObjCAutoRefCount && (OTy->isObjCId() || OTy->isObjCClass())) goto fail; // There's an implicit 'isa' ivar on all objects. // But we only actually find it this way on objects of type 'id', // apparently.ghjg if (OTy->isObjCId() && Member->isStr("isa")) { Diag(MemberLoc, diag::warn_objc_isa_use); return Owned(new (Context) ObjCIsaExpr(BaseExpr.take(), IsArrow, MemberLoc, Context.getObjCClassType())); } if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); goto fail; } if (RequireCompleteType(OpLoc, BaseType, PDiag(diag::err_typecheck_incomplete_tag) << BaseExpr.get()->getSourceRange())) return ExprError(); ObjCInterfaceDecl *ClassDeclared = 0; ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); if (!IV) { // Attempt to correct for typos in ivar names. DeclFilterCCC<ObjCIvarDecl> Validator; Validator.IsObjCIvarLookup = IsArrow; if (TypoCorrection Corrected = CorrectTypo(R.getLookupNameInfo(), LookupMemberName, NULL, NULL, Validator, IDecl)) { IV = Corrected.getCorrectionDeclAs<ObjCIvarDecl>(); Diag(R.getNameLoc(), diag::err_typecheck_member_reference_ivar_suggest) << IDecl->getDeclName() << MemberName << IV->getDeclName() << FixItHint::CreateReplacement(R.getNameLoc(), IV->getNameAsString()); Diag(IV->getLocation(), diag::note_previous_decl) << IV->getDeclName(); // Figure out the class that declares the ivar. assert(!ClassDeclared); Decl *D = cast<Decl>(IV->getDeclContext()); if (ObjCCategoryDecl *CAT = dyn_cast<ObjCCategoryDecl>(D)) D = CAT->getClassInterface(); ClassDeclared = cast<ObjCInterfaceDecl>(D); } else { if (IsArrow && IDecl->FindPropertyDeclaration(Member)) { Diag(MemberLoc, diag::err_property_found_suggest) << Member << BaseExpr.get()->getType() << FixItHint::CreateReplacement(OpLoc, "."); return ExprError(); } Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) << IDecl->getDeclName() << MemberName << BaseExpr.get()->getSourceRange(); return ExprError(); } } assert(ClassDeclared); // If the decl being referenced had an error, return an error for this // sub-expr without emitting another error, in order to avoid cascading // error cases. if (IV->isInvalidDecl()) return ExprError(); // Check whether we can reference this field. if (DiagnoseUseOfDecl(IV, MemberLoc)) return ExprError(); if (IV->getAccessControl() != ObjCIvarDecl::Public && IV->getAccessControl() != ObjCIvarDecl::Package) { ObjCInterfaceDecl *ClassOfMethodDecl = 0; if (ObjCMethodDecl *MD = getCurMethodDecl()) ClassOfMethodDecl = MD->getClassInterface(); else if (ObjCImpDecl && getCurFunctionDecl()) { // Case of a c-function declared inside an objc implementation. // FIXME: For a c-style function nested inside an objc implementation // class, there is no implementation context available, so we pass // down the context as argument to this routine. Ideally, this context // need be passed down in the AST node and somehow calculated from the // AST for a function decl. if (ObjCImplementationDecl *IMPD = dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) ClassOfMethodDecl = IMPD->getClassInterface(); else if (ObjCCategoryImplDecl* CatImplClass = dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) ClassOfMethodDecl = CatImplClass->getClassInterface(); } if (!getLangOpts().DebuggerSupport) { if (IV->getAccessControl() == ObjCIvarDecl::Private) { if (!declaresSameEntity(ClassDeclared, IDecl) || !declaresSameEntity(ClassOfMethodDecl, ClassDeclared)) Diag(MemberLoc, diag::error_private_ivar_access) << IV->getDeclName(); } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) // @protected Diag(MemberLoc, diag::error_protected_ivar_access) << IV->getDeclName(); } } if (getLangOpts().ObjCAutoRefCount) { Expr *BaseExp = BaseExpr.get()->IgnoreParenImpCasts(); if (UnaryOperator *UO = dyn_cast<UnaryOperator>(BaseExp)) if (UO->getOpcode() == UO_Deref) BaseExp = UO->getSubExpr()->IgnoreParenCasts(); if (DeclRefExpr *DE = dyn_cast<DeclRefExpr>(BaseExp)) if (DE->getType().getObjCLifetime() == Qualifiers::OCL_Weak) Diag(DE->getLocation(), diag::error_arc_weak_ivar_access); } return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), MemberLoc, BaseExpr.take(), IsArrow)); } // Objective-C property access. const ObjCObjectPointerType *OPT; if (!IsArrow && (OPT = BaseType->getAs<ObjCObjectPointerType>())) { if (!SS.isEmpty() && !SS.isInvalid()) { Diag(SS.getRange().getBegin(), diag::err_qualified_objc_access) << 0 << SS.getScopeRep() << FixItHint::CreateRemoval(SS.getRange()); SS.clear(); } // This actually uses the base as an r-value. BaseExpr = DefaultLvalueConversion(BaseExpr.take()); if (BaseExpr.isInvalid()) return ExprError(); assert(Context.hasSameUnqualifiedType(BaseType, BaseExpr.get()->getType())); IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); const ObjCObjectType *OT = OPT->getObjectType(); // id, with and without qualifiers. if (OT->isObjCId()) { // Check protocols on qualified interfaces. Selector Sel = PP.getSelectorTable().getNullarySelector(Member); if (Decl *PMDecl = FindGetterSetterNameDecl(OPT, Member, Sel, Context)) { if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { // Check the use of this declaration if (DiagnoseUseOfDecl(PD, MemberLoc)) return ExprError(); return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc, BaseExpr.take())); } if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { // Check the use of this method. if (DiagnoseUseOfDecl(OMD, MemberLoc)) return ExprError(); Selector SetterSel = SelectorTable::constructSetterName(PP.getIdentifierTable(), PP.getSelectorTable(), Member); ObjCMethodDecl *SMD = 0; if (Decl *SDecl = FindGetterSetterNameDecl(OPT, /*Property id*/0, SetterSel, Context)) SMD = dyn_cast<ObjCMethodDecl>(SDecl); return Owned(new (Context) ObjCPropertyRefExpr(OMD, SMD, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc, BaseExpr.take())); } } // Use of id.member can only be for a property reference. Do not // use the 'id' redefinition in this case. if (IsArrow && ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); return ExprError(Diag(MemberLoc, diag::err_property_not_found) << MemberName << BaseType); } // 'Class', unqualified only. if (OT->isObjCClass()) { // Only works in a method declaration (??!). ObjCMethodDecl *MD = getCurMethodDecl(); if (!MD) { if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); goto fail; } // Also must look for a getter name which uses property syntax. Selector Sel = PP.getSelectorTable().getNullarySelector(Member); ObjCInterfaceDecl *IFace = MD->getClassInterface(); ObjCMethodDecl *Getter; if ((Getter = IFace->lookupClassMethod(Sel))) { // Check the use of this method. if (DiagnoseUseOfDecl(Getter, MemberLoc)) return ExprError(); } else Getter = IFace->lookupPrivateMethod(Sel, false); // If we found a getter then this may be a valid dot-reference, we // will look for the matching setter, in case it is needed. Selector SetterSel = SelectorTable::constructSetterName(PP.getIdentifierTable(), PP.getSelectorTable(), Member); ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); if (!Setter) { // If this reference is in an @implementation, also check for 'private' // methods. Setter = IFace->lookupPrivateMethod(SetterSel, false); } // Look through local category implementations associated with the class. if (!Setter) Setter = IFace->getCategoryClassMethod(SetterSel); if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) return ExprError(); if (Getter || Setter) { return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc, BaseExpr.take())); } if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); return ExprError(Diag(MemberLoc, diag::err_property_not_found) << MemberName << BaseType); } // Normal property access. return HandleExprPropertyRefExpr(OPT, BaseExpr.get(), OpLoc, MemberName, MemberLoc, SourceLocation(), QualType(), false); } // Handle 'field access' to vectors, such as 'V.xx'. if (BaseType->isExtVectorType()) { // FIXME: this expr should store IsArrow. IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); ExprValueKind VK = (IsArrow ? VK_LValue : BaseExpr.get()->getValueKind()); QualType ret = CheckExtVectorComponent(*this, BaseType, VK, OpLoc, Member, MemberLoc); if (ret.isNull()) return ExprError(); return Owned(new (Context) ExtVectorElementExpr(ret, VK, BaseExpr.take(), *Member, MemberLoc)); } // Adjust builtin-sel to the appropriate redefinition type if that's // not just a pointer to builtin-sel again. if (IsArrow && BaseType->isSpecificBuiltinType(BuiltinType::ObjCSel) && !Context.getObjCSelRedefinitionType()->isObjCSelType()) { BaseExpr = ImpCastExprToType(BaseExpr.take(), Context.getObjCSelRedefinitionType(), CK_BitCast); return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); } // Failure cases. fail: // Recover from dot accesses to pointers, e.g.: // type *foo; // foo.bar // This is actually well-formed in two cases: // - 'type' is an Objective C type // - 'bar' is a pseudo-destructor name which happens to refer to // the appropriate pointer type if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { if (!IsArrow && Ptr->getPointeeType()->isRecordType() && MemberName.getNameKind() != DeclarationName::CXXDestructorName) { Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange() << FixItHint::CreateReplacement(OpLoc, "->"); // Recurse as an -> access. IsArrow = true; return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); } } // If the user is trying to apply -> or . to a function name, it's probably // because they forgot parentheses to call that function. if (tryToRecoverWithCall(BaseExpr, PDiag(diag::err_member_reference_needs_call), /*complain*/ false, IsArrow ? &isPointerToRecordType : &isRecordType)) { if (BaseExpr.isInvalid()) return ExprError(); BaseExpr = DefaultFunctionArrayConversion(BaseExpr.take()); return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, ObjCImpDecl, HasTemplateArgs); } Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) << BaseType << BaseExpr.get()->getSourceRange(); return ExprError(); } /// The main callback when the parser finds something like /// expression . [nested-name-specifier] identifier /// expression -> [nested-name-specifier] identifier /// where 'identifier' encompasses a fairly broad spectrum of /// possibilities, including destructor and operator references. /// /// \param OpKind either tok::arrow or tok::period /// \param HasTrailingLParen whether the next token is '(', which /// is used to diagnose mis-uses of special members that can /// only be called /// \param ObjCImpDecl the current ObjC @implementation decl; /// this is an ugly hack around the fact that ObjC @implementations /// aren't properly put in the context chain ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, SourceLocation OpLoc, tok::TokenKind OpKind, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, UnqualifiedId &Id, Decl *ObjCImpDecl, bool HasTrailingLParen) { if (SS.isSet() && SS.isInvalid()) return ExprError(); // Warn about the explicit constructor calls Microsoft extension. if (getLangOpts().MicrosoftExt && Id.getKind() == UnqualifiedId::IK_ConstructorName) Diag(Id.getSourceRange().getBegin(), diag::ext_ms_explicit_constructor_call); TemplateArgumentListInfo TemplateArgsBuffer; // Decompose the name into its component parts. DeclarationNameInfo NameInfo; const TemplateArgumentListInfo *TemplateArgs; DecomposeUnqualifiedId(Id, TemplateArgsBuffer, NameInfo, TemplateArgs); DeclarationName Name = NameInfo.getName(); bool IsArrow = (OpKind == tok::arrow); NamedDecl *FirstQualifierInScope = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); // This is a postfix expression, so get rid of ParenListExprs. ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); if (Result.isInvalid()) return ExprError(); Base = Result.take(); if (Base->getType()->isDependentType() || Name.isDependentName() || isDependentScopeSpecifier(SS)) { Result = ActOnDependentMemberExpr(Base, Base->getType(), IsArrow, OpLoc, SS, TemplateKWLoc, FirstQualifierInScope, NameInfo, TemplateArgs); } else { LookupResult R(*this, NameInfo, LookupMemberName); ExprResult BaseResult = Owned(Base); Result = LookupMemberExpr(R, BaseResult, IsArrow, OpLoc, SS, ObjCImpDecl, TemplateArgs != 0); if (BaseResult.isInvalid()) return ExprError(); Base = BaseResult.take(); if (Result.isInvalid()) { Owned(Base); return ExprError(); } if (Result.get()) { // The only way a reference to a destructor can be used is to // immediately call it, which falls into this case. If the // next token is not a '(', produce a diagnostic and build the // call now. if (!HasTrailingLParen && Id.getKind() == UnqualifiedId::IK_DestructorName) return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); return move(Result); } Result = BuildMemberReferenceExpr(Base, Base->getType(), OpLoc, IsArrow, SS, TemplateKWLoc, FirstQualifierInScope, R, TemplateArgs); } return move(Result); } static ExprResult BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, const CXXScopeSpec &SS, FieldDecl *Field, DeclAccessPair FoundDecl, const DeclarationNameInfo &MemberNameInfo) { // x.a is an l-value if 'a' has a reference type. Otherwise: // x.a is an l-value/x-value/pr-value if the base is (and note // that *x is always an l-value), except that if the base isn't // an ordinary object then we must have an rvalue. ExprValueKind VK = VK_LValue; ExprObjectKind OK = OK_Ordinary; if (!IsArrow) { if (BaseExpr->getObjectKind() == OK_Ordinary) VK = BaseExpr->getValueKind(); else VK = VK_RValue; } if (VK != VK_RValue && Field->isBitField()) OK = OK_BitField; // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] QualType MemberType = Field->getType(); if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) { MemberType = Ref->getPointeeType(); VK = VK_LValue; } else { QualType BaseType = BaseExpr->getType(); if (IsArrow) BaseType = BaseType->getAs<PointerType>()->getPointeeType(); Qualifiers BaseQuals = BaseType.getQualifiers(); // GC attributes are never picked up by members. BaseQuals.removeObjCGCAttr(); // CVR attributes from the base are picked up by members, // except that 'mutable' members don't pick up 'const'. if (Field->isMutable()) BaseQuals.removeConst(); Qualifiers MemberQuals = S.Context.getCanonicalType(MemberType).getQualifiers(); // TR 18037 does not allow fields to be declared with address spaces. assert(!MemberQuals.hasAddressSpace()); Qualifiers Combined = BaseQuals + MemberQuals; if (Combined != MemberQuals) MemberType = S.Context.getQualifiedType(MemberType, Combined); } ExprResult Base = S.PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(), FoundDecl, Field); if (Base.isInvalid()) return ExprError(); return S.Owned(BuildMemberExpr(S, S.Context, Base.take(), IsArrow, SS, /*TemplateKWLoc=*/SourceLocation(), Field, FoundDecl, MemberNameInfo, MemberType, VK, OK)); } /// Builds an implicit member access expression. The current context /// is known to be an instance method, and the given unqualified lookup /// set is known to contain only instance members, at least one of which /// is from an appropriate type. ExprResult Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R, const TemplateArgumentListInfo *TemplateArgs, bool IsKnownInstance) { assert(!R.empty() && !R.isAmbiguous()); SourceLocation loc = R.getNameLoc(); // We may have found a field within an anonymous union or struct // (C++ [class.union]). // FIXME: template-ids inside anonymous structs? if (IndirectFieldDecl *FD = R.getAsSingle<IndirectFieldDecl>()) return BuildAnonymousStructUnionMemberReference(SS, R.getNameLoc(), FD); // If this is known to be an instance access, go ahead and build an // implicit 'this' expression now. // 'this' expression now. QualType ThisTy = getCurrentThisType(); assert(!ThisTy.isNull() && "didn't correctly pre-flight capture of 'this'"); Expr *baseExpr = 0; // null signifies implicit access if (IsKnownInstance) { SourceLocation Loc = R.getNameLoc(); if (SS.getRange().isValid()) Loc = SS.getRange().getBegin(); CheckCXXThisCapture(Loc); baseExpr = new (Context) CXXThisExpr(loc, ThisTy, /*isImplicit=*/true); } return BuildMemberReferenceExpr(baseExpr, ThisTy, /*OpLoc*/ SourceLocation(), /*IsArrow*/ true, SS, TemplateKWLoc, /*FirstQualifierInScope*/ 0, R, TemplateArgs); }