//===--- SemaDecl.cpp - Semantic Analysis for 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 declarations. // //===----------------------------------------------------------------------===// #include "Sema.h" #include "clang/AST/APValue.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/ExprCXX.h" #include "clang/Parse/DeclSpec.h" #include "clang/Basic/Diagnostic.h" #include "clang/Basic/TargetInfo.h" #include "clang/Basic/SourceManager.h" // FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) #include "clang/Lex/Preprocessor.h" #include "clang/Lex/HeaderSearch.h" #include "llvm/ADT/SmallSet.h" using namespace clang; Sema::TypeTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) { Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, false); if (IIDecl && (isa(IIDecl) || isa(IIDecl) || isa(IIDecl))) return IIDecl; return 0; } DeclContext *Sema::getDCParent(DeclContext *DC) { // If CurContext is a ObjC method, getParent() will return NULL. if (isa(DC)) return Context.getTranslationUnitDecl(); // A C++ inline method is parsed *after* the topmost class it was declared in // is fully parsed (it's "complete"). // The parsing of a C++ inline method happens at the declaration context of // the topmost (non-nested) class it is declared in. if (CXXMethodDecl *MD = dyn_cast(DC)) { assert(isa(MD->getParent()) && "C++ method not in Record."); DC = MD->getParent(); while (CXXRecordDecl *RD = dyn_cast(DC->getParent())) DC = RD; // Return the declaration context of the topmost class the inline method is // declared in. return DC; } return DC->getParent(); } void Sema::PushDeclContext(DeclContext *DC) { assert(getDCParent(DC) == CurContext && "The next DeclContext should be directly contained in the current one."); CurContext = DC; } void Sema::PopDeclContext() { assert(CurContext && "DeclContext imbalance!"); CurContext = getDCParent(CurContext); } /// Add this decl to the scope shadowed decl chains. void Sema::PushOnScopeChains(NamedDecl *D, Scope *S) { S->AddDecl(D); // C++ [basic.scope]p4: // -- exactly one declaration shall declare a class name or // enumeration name that is not a typedef name and the other // declarations shall all refer to the same object or // enumerator, or all refer to functions and function templates; // in this case the class name or enumeration name is hidden. if (TagDecl *TD = dyn_cast(D)) { // We are pushing the name of a tag (enum or class). IdentifierResolver::iterator I = IdResolver.begin(TD->getIdentifier(), TD->getDeclContext(), false/*LookInParentCtx*/); if (I != IdResolver.end() && isDeclInScope(*I, TD->getDeclContext(), S)) { // There is already a declaration with the same name in the same // scope. It must be found before we find the new declaration, // so swap the order on the shadowed declaration chain. IdResolver.AddShadowedDecl(TD, *I); return; } } IdResolver.AddDecl(D); } void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { if (S->decl_empty()) return; assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!"); for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end(); I != E; ++I) { Decl *TmpD = static_cast(*I); assert(TmpD && "This decl didn't get pushed??"); if (isa(TmpD)) continue; assert(isa(TmpD) && "Decl isn't ScopedDecl?"); ScopedDecl *D = cast(TmpD); IdentifierInfo *II = D->getIdentifier(); if (!II) continue; // We only want to remove the decls from the identifier decl chains for // local scopes, when inside a function/method. if (S->getFnParent() != 0) IdResolver.RemoveDecl(D); // Chain this decl to the containing DeclContext. D->setNext(CurContext->getDeclChain()); CurContext->setDeclChain(D); } } /// getObjCInterfaceDecl - Look up a for a class declaration in the scope. /// return 0 if one not found. ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *Id) { // The third "scope" argument is 0 since we aren't enabling lazy built-in // creation from this context. Decl *IDecl = LookupDecl(Id, Decl::IDNS_Ordinary, 0, false); return dyn_cast_or_null(IDecl); } /// LookupDecl - Look up the inner-most declaration in the specified /// namespace. Decl *Sema::LookupDecl(const IdentifierInfo *II, unsigned NSI, Scope *S, bool enableLazyBuiltinCreation) { if (II == 0) return 0; unsigned NS = NSI; if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary)) NS |= Decl::IDNS_Tag; // Scan up the scope chain looking for a decl that matches this identifier // that is in the appropriate namespace. This search should not take long, as // shadowing of names is uncommon, and deep shadowing is extremely uncommon. for (IdentifierResolver::iterator I = IdResolver.begin(II, CurContext), E = IdResolver.end(); I != E; ++I) if ((*I)->getIdentifierNamespace() & NS) return *I; // If we didn't find a use of this identifier, and if the identifier // corresponds to a compiler builtin, create the decl object for the builtin // now, injecting it into translation unit scope, and return it. if (NS & Decl::IDNS_Ordinary) { if (enableLazyBuiltinCreation) { // If this is a builtin on this (or all) targets, create the decl. if (unsigned BuiltinID = II->getBuiltinID()) return LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S); } if (getLangOptions().ObjC1) { // @interface and @compatibility_alias introduce typedef-like names. // Unlike typedef's, they can only be introduced at file-scope (and are // therefore not scoped decls). They can, however, be shadowed by // other names in IDNS_Ordinary. ObjCInterfaceDeclsTy::iterator IDI = ObjCInterfaceDecls.find(II); if (IDI != ObjCInterfaceDecls.end()) return IDI->second; ObjCAliasTy::iterator I = ObjCAliasDecls.find(II); if (I != ObjCAliasDecls.end()) return I->second->getClassInterface(); } } return 0; } void Sema::InitBuiltinVaListType() { if (!Context.getBuiltinVaListType().isNull()) return; IdentifierInfo *VaIdent = &Context.Idents.get("__builtin_va_list"); Decl *VaDecl = LookupDecl(VaIdent, Decl::IDNS_Ordinary, TUScope); TypedefDecl *VaTypedef = cast(VaDecl); Context.setBuiltinVaListType(Context.getTypedefType(VaTypedef)); } /// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope. /// lazily create a decl for it. ScopedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, Scope *S) { Builtin::ID BID = (Builtin::ID)bid; if (Context.BuiltinInfo.hasVAListUse(BID)) InitBuiltinVaListType(); QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context); FunctionDecl *New = FunctionDecl::Create(Context, Context.getTranslationUnitDecl(), SourceLocation(), II, R, FunctionDecl::Extern, false, 0); // Create Decl objects for each parameter, adding them to the // FunctionDecl. if (FunctionTypeProto *FT = dyn_cast(R)) { llvm::SmallVector Params; for (unsigned i = 0, e = FT->getNumArgs(); i != e; ++i) Params.push_back(ParmVarDecl::Create(Context, New, SourceLocation(), 0, FT->getArgType(i), VarDecl::None, 0, 0)); New->setParams(&Params[0], Params.size()); } // TUScope is the translation-unit scope to insert this function into. PushOnScopeChains(New, TUScope); return New; } /// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name /// and scope as a previous declaration 'Old'. Figure out how to resolve this /// situation, merging decls or emitting diagnostics as appropriate. /// TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) { // Allow multiple definitions for ObjC built-in typedefs. // FIXME: Verify the underlying types are equivalent! if (getLangOptions().ObjC1) { const IdentifierInfo *typeIdent = New->getIdentifier(); if (typeIdent == Ident_id) { Context.setObjCIdType(New); return New; } else if (typeIdent == Ident_Class) { Context.setObjCClassType(New); return New; } else if (typeIdent == Ident_SEL) { Context.setObjCSelType(New); return New; } else if (typeIdent == Ident_Protocol) { Context.setObjCProtoType(New->getUnderlyingType()); return New; } // Fall through - the typedef name was not a builtin type. } // Verify the old decl was also a typedef. TypedefDecl *Old = dyn_cast(OldD); if (!Old) { Diag(New->getLocation(), diag::err_redefinition_different_kind, New->getName()); Diag(OldD->getLocation(), diag::err_previous_definition); return New; } // If the typedef types are not identical, reject them in all languages and // with any extensions enabled. if (Old->getUnderlyingType() != New->getUnderlyingType() && Context.getCanonicalType(Old->getUnderlyingType()) != Context.getCanonicalType(New->getUnderlyingType())) { Diag(New->getLocation(), diag::err_redefinition_different_typedef, New->getUnderlyingType().getAsString(), Old->getUnderlyingType().getAsString()); Diag(Old->getLocation(), diag::err_previous_definition); return Old; } if (getLangOptions().Microsoft) return New; // Redeclaration of a type is a constraint violation (6.7.2.3p1). // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if // *either* declaration is in a system header. The code below implements // this adhoc compatibility rule. FIXME: The following code will not // work properly when compiling ".i" files (containing preprocessed output). if (PP.getDiagnostics().getSuppressSystemWarnings()) { SourceManager &SrcMgr = Context.getSourceManager(); if (SrcMgr.isInSystemHeader(Old->getLocation())) return New; if (SrcMgr.isInSystemHeader(New->getLocation())) return New; } Diag(New->getLocation(), diag::err_redefinition, New->getName()); Diag(Old->getLocation(), diag::err_previous_definition); return New; } /// DeclhasAttr - returns true if decl Declaration already has the target /// attribute. static bool DeclHasAttr(const Decl *decl, const Attr *target) { for (const Attr *attr = decl->getAttrs(); attr; attr = attr->getNext()) if (attr->getKind() == target->getKind()) return true; return false; } /// MergeAttributes - append attributes from the Old decl to the New one. static void MergeAttributes(Decl *New, Decl *Old) { Attr *attr = const_cast(Old->getAttrs()), *tmp; while (attr) { tmp = attr; attr = attr->getNext(); if (!DeclHasAttr(New, tmp)) { New->addAttr(tmp); } else { tmp->setNext(0); delete(tmp); } } Old->invalidateAttrs(); } /// MergeFunctionDecl - We just parsed a function 'New' from /// declarator D which has the same name and scope as a previous /// declaration 'Old'. Figure out how to resolve this situation, /// merging decls or emitting diagnostics as appropriate. /// Redeclaration will be set true if thisNew is a redeclaration OldD. FunctionDecl * Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) { Redeclaration = false; // Verify the old decl was also a function. FunctionDecl *Old = dyn_cast(OldD); if (!Old) { Diag(New->getLocation(), diag::err_redefinition_different_kind, New->getName()); Diag(OldD->getLocation(), diag::err_previous_definition); return New; } QualType OldQType = Context.getCanonicalType(Old->getType()); QualType NewQType = Context.getCanonicalType(New->getType()); // C++ [dcl.fct]p3: // All declarations for a function shall agree exactly in both the // return type and the parameter-type-list. if (getLangOptions().CPlusPlus && OldQType == NewQType) { MergeAttributes(New, Old); Redeclaration = true; return MergeCXXFunctionDecl(New, Old); } // C: Function types need to be compatible, not identical. This handles // duplicate function decls like "void f(int); void f(enum X);" properly. if (!getLangOptions().CPlusPlus && Context.typesAreCompatible(OldQType, NewQType)) { MergeAttributes(New, Old); Redeclaration = true; return New; } // A function that has already been declared has been redeclared or defined // with a different type- show appropriate diagnostic diag::kind PrevDiag; if (Old->isThisDeclarationADefinition()) PrevDiag = diag::err_previous_definition; else if (Old->isImplicit()) PrevDiag = diag::err_previous_implicit_declaration; else PrevDiag = diag::err_previous_declaration; // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. // TODO: This is totally simplistic. It should handle merging functions // together etc, merging extern int X; int X; ... Diag(New->getLocation(), diag::err_conflicting_types, New->getName()); Diag(Old->getLocation(), PrevDiag); return New; } /// Predicate for C "tentative" external object definitions (C99 6.9.2). static bool isTentativeDefinition(VarDecl *VD) { if (VD->isFileVarDecl()) return (!VD->getInit() && (VD->getStorageClass() == VarDecl::None || VD->getStorageClass() == VarDecl::Static)); return false; } /// CheckForFileScopedRedefinitions - Make sure we forgo redefinition errors /// when dealing with C "tentative" external object definitions (C99 6.9.2). void Sema::CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD) { bool VDIsTentative = isTentativeDefinition(VD); bool VDIsIncompleteArray = VD->getType()->isIncompleteArrayType(); for (IdentifierResolver::iterator I = IdResolver.begin(VD->getIdentifier(), VD->getDeclContext(), false/*LookInParentCtx*/), E = IdResolver.end(); I != E; ++I) { if (*I != VD && isDeclInScope(*I, VD->getDeclContext(), S)) { VarDecl *OldDecl = dyn_cast(*I); // Handle the following case: // int a[10]; // int a[]; - the code below makes sure we set the correct type. // int a[11]; - this is an error, size isn't 10. if (OldDecl && VDIsTentative && VDIsIncompleteArray && OldDecl->getType()->isConstantArrayType()) VD->setType(OldDecl->getType()); // Check for "tentative" definitions. We can't accomplish this in // MergeVarDecl since the initializer hasn't been attached. if (!OldDecl || isTentativeDefinition(OldDecl) || VDIsTentative) continue; // Handle __private_extern__ just like extern. if (OldDecl->getStorageClass() != VarDecl::Extern && OldDecl->getStorageClass() != VarDecl::PrivateExtern && VD->getStorageClass() != VarDecl::Extern && VD->getStorageClass() != VarDecl::PrivateExtern) { Diag(VD->getLocation(), diag::err_redefinition, VD->getName()); Diag(OldDecl->getLocation(), diag::err_previous_definition); } } } } /// MergeVarDecl - We just parsed a variable 'New' which has the same name /// and scope as a previous declaration 'Old'. Figure out how to resolve this /// situation, merging decls or emitting diagnostics as appropriate. /// /// Tentative definition rules (C99 6.9.2p2) are checked by /// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative /// definitions here, since the initializer hasn't been attached. /// VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) { // Verify the old decl was also a variable. VarDecl *Old = dyn_cast(OldD); if (!Old) { Diag(New->getLocation(), diag::err_redefinition_different_kind, New->getName()); Diag(OldD->getLocation(), diag::err_previous_definition); return New; } MergeAttributes(New, Old); // Verify the types match. QualType OldCType = Context.getCanonicalType(Old->getType()); QualType NewCType = Context.getCanonicalType(New->getType()); if (OldCType != NewCType && !Context.typesAreCompatible(OldCType, NewCType)) { Diag(New->getLocation(), diag::err_redefinition, New->getName()); Diag(Old->getLocation(), diag::err_previous_definition); return New; } // C99 6.2.2p4: Check if we have a static decl followed by a non-static. if (New->getStorageClass() == VarDecl::Static && (Old->getStorageClass() == VarDecl::None || Old->getStorageClass() == VarDecl::Extern)) { Diag(New->getLocation(), diag::err_static_non_static, New->getName()); Diag(Old->getLocation(), diag::err_previous_definition); return New; } // C99 6.2.2p4: Check if we have a non-static decl followed by a static. if (New->getStorageClass() != VarDecl::Static && Old->getStorageClass() == VarDecl::Static) { Diag(New->getLocation(), diag::err_non_static_static, New->getName()); Diag(Old->getLocation(), diag::err_previous_definition); return New; } // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. if (New->getStorageClass() != VarDecl::Extern && !New->isFileVarDecl()) { Diag(New->getLocation(), diag::err_redefinition, New->getName()); Diag(Old->getLocation(), diag::err_previous_definition); } return New; } /// CheckParmsForFunctionDef - Check that the parameters of the given /// function are appropriate for the definition of a function. This /// takes care of any checks that cannot be performed on the /// declaration itself, e.g., that the types of each of the function /// parameters are complete. bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { bool HasInvalidParm = false; for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { ParmVarDecl *Param = FD->getParamDecl(p); // C99 6.7.5.3p4: the parameters in a parameter type list in a // function declarator that is part of a function definition of // that function shall not have incomplete type. if (Param->getType()->isIncompleteType() && !Param->isInvalidDecl()) { Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type, Param->getType().getAsString()); Param->setInvalidDecl(); HasInvalidParm = true; } } return HasInvalidParm; } /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with /// no declarator (e.g. "struct foo;") is parsed. Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) { // TODO: emit error on 'int;' or 'const enum foo;'. // TODO: emit error on 'typedef int;' // if (!DS.isMissingDeclaratorOk()) Diag(...); return dyn_cast_or_null(static_cast(DS.getTypeRep())); } bool Sema::CheckSingleInitializer(Expr *&Init, QualType DeclType) { // Get the type before calling CheckSingleAssignmentConstraints(), since // it can promote the expression. QualType InitType = Init->getType(); AssignConvertType ConvTy = CheckSingleAssignmentConstraints(DeclType, Init); return DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, InitType, Init, "initializing"); } bool Sema::CheckStringLiteralInit(StringLiteral *strLiteral, QualType &DeclT) { const ArrayType *AT = Context.getAsArrayType(DeclT); if (const IncompleteArrayType *IAT = dyn_cast(AT)) { // C99 6.7.8p14. We have an array of character type with unknown size // being initialized to a string literal. llvm::APSInt ConstVal(32); ConstVal = strLiteral->getByteLength() + 1; // Return a new array type (C99 6.7.8p22). DeclT = Context.getConstantArrayType(IAT->getElementType(), ConstVal, ArrayType::Normal, 0); } else { const ConstantArrayType *CAT = cast(AT); // C99 6.7.8p14. We have an array of character type with known size. // FIXME: Avoid truncation for 64-bit length strings. if (strLiteral->getByteLength() > (unsigned)CAT->getSize().getZExtValue()) Diag(strLiteral->getSourceRange().getBegin(), diag::warn_initializer_string_for_char_array_too_long, strLiteral->getSourceRange()); } // Set type from "char *" to "constant array of char". strLiteral->setType(DeclT); // For now, we always return false (meaning success). return false; } StringLiteral *Sema::IsStringLiteralInit(Expr *Init, QualType DeclType) { const ArrayType *AT = Context.getAsArrayType(DeclType); if (AT && AT->getElementType()->isCharType()) { return dyn_cast(Init); } return 0; } bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType) { // C99 6.7.8p3: The type of the entity to be initialized shall be an array // of unknown size ("[]") or an object type that is not a variable array type. if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) return Diag(VAT->getSizeExpr()->getLocStart(), diag::err_variable_object_no_init, VAT->getSizeExpr()->getSourceRange()); InitListExpr *InitList = dyn_cast(Init); if (!InitList) { // FIXME: Handle wide strings if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType)) return CheckStringLiteralInit(strLiteral, DeclType); // C99 6.7.8p16. if (DeclType->isArrayType()) return Diag(Init->getLocStart(), diag::err_array_init_list_required, Init->getSourceRange()); return CheckSingleInitializer(Init, DeclType); } InitListChecker CheckInitList(this, InitList, DeclType); return CheckInitList.HadError(); } Sema::DeclTy * Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) { ScopedDecl *LastDeclarator = dyn_cast_or_null((Decl *)lastDecl); IdentifierInfo *II = D.getIdentifier(); // All of these full declarators require an identifier. If it doesn't have // one, the ParsedFreeStandingDeclSpec action should be used. if (II == 0) { Diag(D.getDeclSpec().getSourceRange().getBegin(), diag::err_declarator_need_ident, D.getDeclSpec().getSourceRange(), D.getSourceRange()); return 0; } // The scope passed in may not be a decl scope. Zip up the scope tree until // we find one that is. while ((S->getFlags() & Scope::DeclScope) == 0) S = S->getParent(); // See if this is a redefinition of a variable in the same scope. Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S); ScopedDecl *New; bool InvalidDecl = false; // In C++, the previous declaration we find might be a tag type // (class or enum). In this case, the new declaration will hide the // tag type. if (PrevDecl && PrevDecl->getIdentifierNamespace() == Decl::IDNS_Tag) PrevDecl = 0; QualType R = GetTypeForDeclarator(D, S); assert(!R.isNull() && "GetTypeForDeclarator() returned null type"); if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { // Check that there are no default arguments (C++ only). if (getLangOptions().CPlusPlus) CheckExtraCXXDefaultArguments(D); TypedefDecl *NewTD = ParseTypedefDecl(S, D, R, LastDeclarator); if (!NewTD) return 0; // Handle attributes prior to checking for duplicates in MergeVarDecl ProcessDeclAttributes(NewTD, D); // Merge the decl with the existing one if appropriate. If the decl is // in an outer scope, it isn't the same thing. if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)) { NewTD = MergeTypeDefDecl(NewTD, PrevDecl); if (NewTD == 0) return 0; } New = NewTD; if (S->getFnParent() == 0) { // C99 6.7.7p2: If a typedef name specifies a variably modified type // then it shall have block scope. if (NewTD->getUnderlyingType()->isVariablyModifiedType()) { // FIXME: Diagnostic needs to be fixed. Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla); InvalidDecl = true; } } } else if (R.getTypePtr()->isFunctionType()) { FunctionDecl::StorageClass SC = FunctionDecl::None; switch (D.getDeclSpec().getStorageClassSpec()) { default: assert(0 && "Unknown storage class!"); case DeclSpec::SCS_auto: case DeclSpec::SCS_register: Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func, R.getAsString()); InvalidDecl = true; break; case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break; case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break; case DeclSpec::SCS_static: SC = FunctionDecl::Static; break; case DeclSpec::SCS_private_extern: SC = FunctionDecl::PrivateExtern;break; } bool isInline = D.getDeclSpec().isInlineSpecified(); FunctionDecl *NewFD; if (D.getContext() == Declarator::MemberContext) { // This is a C++ method declaration. NewFD = CXXMethodDecl::Create(Context, cast(CurContext), D.getIdentifierLoc(), II, R, (SC == FunctionDecl::Static), isInline, LastDeclarator); } else { NewFD = FunctionDecl::Create(Context, CurContext, D.getIdentifierLoc(), II, R, SC, isInline, LastDeclarator); } // Handle attributes. ProcessDeclAttributes(NewFD, D); // Handle GNU asm-label extension (encoded as an attribute). if (Expr *E = (Expr*) D.getAsmLabel()) { // The parser guarantees this is a string. StringLiteral *SE = cast(E); NewFD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), SE->getByteLength()))); } // Copy the parameter declarations from the declarator D to // the function declaration NewFD, if they are available. if (D.getNumTypeObjects() > 0) { DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; // Create Decl objects for each parameter, adding them to the // FunctionDecl. llvm::SmallVector Params; // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs // function that takes no arguments, not a function that takes a // single void argument. // We let through "const void" here because Sema::GetTypeForDeclarator // already checks for that case. if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && FTI.ArgInfo[0].Param && ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) { // empty arg list, don't push any params. ParmVarDecl *Param = (ParmVarDecl*)FTI.ArgInfo[0].Param; // In C++, the empty parameter-type-list must be spelled "void"; a // typedef of void is not permitted. if (getLangOptions().CPlusPlus && Param->getType().getUnqualifiedType() != Context.VoidTy) { Diag(Param->getLocation(), diag::ext_param_typedef_of_void); } } else if (FTI.NumArgs > 0 && FTI.ArgInfo[0].Param != 0) { for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param); } NewFD->setParams(&Params[0], Params.size()); } // Merge the decl with the existing one if appropriate. Since C functions // are in a flat namespace, make sure we consider decls in outer scopes. if (PrevDecl && (!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, CurContext, S))) { bool Redeclaration = false; NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration); if (NewFD == 0) return 0; if (Redeclaration) { NewFD->setPreviousDeclaration(cast(PrevDecl)); } } New = NewFD; // In C++, check default arguments now that we have merged decls. if (getLangOptions().CPlusPlus) CheckCXXDefaultArguments(NewFD); } else { // Check that there are no default arguments (C++ only). if (getLangOptions().CPlusPlus) CheckExtraCXXDefaultArguments(D); if (R.getTypePtr()->isObjCInterfaceType()) { Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object, D.getIdentifier()->getName()); InvalidDecl = true; } VarDecl *NewVD; VarDecl::StorageClass SC; switch (D.getDeclSpec().getStorageClassSpec()) { default: assert(0 && "Unknown storage class!"); case DeclSpec::SCS_unspecified: SC = VarDecl::None; break; case DeclSpec::SCS_extern: SC = VarDecl::Extern; break; case DeclSpec::SCS_static: SC = VarDecl::Static; break; case DeclSpec::SCS_auto: SC = VarDecl::Auto; break; case DeclSpec::SCS_register: SC = VarDecl::Register; break; case DeclSpec::SCS_private_extern: SC = VarDecl::PrivateExtern; break; } if (D.getContext() == Declarator::MemberContext) { assert(SC == VarDecl::Static && "Invalid storage class for member!"); // This is a static data member for a C++ class. NewVD = CXXClassVarDecl::Create(Context, cast(CurContext), D.getIdentifierLoc(), II, R, LastDeclarator); } else { bool ThreadSpecified = D.getDeclSpec().isThreadSpecified(); if (S->getFnParent() == 0) { // C99 6.9p2: The storage-class specifiers auto and register shall not // appear in the declaration specifiers in an external declaration. if (SC == VarDecl::Auto || SC == VarDecl::Register) { Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope, R.getAsString()); InvalidDecl = true; } } NewVD = VarDecl::Create(Context, CurContext, D.getIdentifierLoc(), II, R, SC, LastDeclarator); NewVD->setThreadSpecified(ThreadSpecified); } // Handle attributes prior to checking for duplicates in MergeVarDecl ProcessDeclAttributes(NewVD, D); // Handle GNU asm-label extension (encoded as an attribute). if (Expr *E = (Expr*) D.getAsmLabel()) { // The parser guarantees this is a string. StringLiteral *SE = cast(E); NewVD->addAttr(new AsmLabelAttr(std::string(SE->getStrData(), SE->getByteLength()))); } // Emit an error if an address space was applied to decl with local storage. // This includes arrays of objects with address space qualifiers, but not // automatic variables that point to other address spaces. // ISO/IEC TR 18037 S5.1.2 if (NewVD->hasLocalStorage() && (NewVD->getType().getAddressSpace() != 0)) { Diag(D.getIdentifierLoc(), diag::err_as_qualified_auto_decl); InvalidDecl = true; } // Merge the decl with the existing one if appropriate. If the decl is // in an outer scope, it isn't the same thing. if (PrevDecl && isDeclInScope(PrevDecl, CurContext, S)) { NewVD = MergeVarDecl(NewVD, PrevDecl); if (NewVD == 0) return 0; } New = NewVD; } // If this has an identifier, add it to the scope stack. if (II) PushOnScopeChains(New, S); // If any semantic error occurred, mark the decl as invalid. if (D.getInvalidType() || InvalidDecl) New->setInvalidDecl(); return New; } bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) { switch (Init->getStmtClass()) { default: Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case Expr::ParenExprClass: { const ParenExpr* PE = cast(Init); return CheckAddressConstantExpressionLValue(PE->getSubExpr()); } case Expr::CompoundLiteralExprClass: return cast(Init)->isFileScope(); case Expr::DeclRefExprClass: { const Decl *D = cast(Init)->getDecl(); if (const VarDecl *VD = dyn_cast(D)) { if (VD->hasGlobalStorage()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } if (isa(D)) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::MemberExprClass: { const MemberExpr *M = cast(Init); if (M->isArrow()) return CheckAddressConstantExpression(M->getBase()); return CheckAddressConstantExpressionLValue(M->getBase()); } case Expr::ArraySubscriptExprClass: { // FIXME: Should we pedwarn for "x[0+0]" (where x is a pointer)? const ArraySubscriptExpr *ASE = cast(Init); return CheckAddressConstantExpression(ASE->getBase()) || CheckArithmeticConstantExpression(ASE->getIdx()); } case Expr::StringLiteralClass: case Expr::PredefinedExprClass: return false; case Expr::UnaryOperatorClass: { const UnaryOperator *Exp = cast(Init); // C99 6.6p9 if (Exp->getOpcode() == UnaryOperator::Deref) return CheckAddressConstantExpression(Exp->getSubExpr()); Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } } } bool Sema::CheckAddressConstantExpression(const Expr* Init) { switch (Init->getStmtClass()) { default: Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case Expr::ParenExprClass: { const ParenExpr* PE = cast(Init); return CheckAddressConstantExpression(PE->getSubExpr()); } case Expr::StringLiteralClass: case Expr::ObjCStringLiteralClass: return false; case Expr::CallExprClass: { const CallExpr *CE = cast(Init); if (CE->isBuiltinConstantExpr()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::UnaryOperatorClass: { const UnaryOperator *Exp = cast(Init); // C99 6.6p9 if (Exp->getOpcode() == UnaryOperator::AddrOf) return CheckAddressConstantExpressionLValue(Exp->getSubExpr()); if (Exp->getOpcode() == UnaryOperator::Extension) return CheckAddressConstantExpression(Exp->getSubExpr()); Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::BinaryOperatorClass: { // FIXME: Should we pedwarn for expressions like "a + 1 + 2"? const BinaryOperator *Exp = cast(Init); Expr *PExp = Exp->getLHS(); Expr *IExp = Exp->getRHS(); if (IExp->getType()->isPointerType()) std::swap(PExp, IExp); // FIXME: Should we pedwarn if IExp isn't an integer constant expression? return CheckAddressConstantExpression(PExp) || CheckArithmeticConstantExpression(IExp); } case Expr::ImplicitCastExprClass: case Expr::ExplicitCastExprClass: { const Expr* SubExpr = cast(Init)->getSubExpr(); if (Init->getStmtClass() == Expr::ImplicitCastExprClass) { // Check for implicit promotion if (SubExpr->getType()->isFunctionType() || SubExpr->getType()->isArrayType()) return CheckAddressConstantExpressionLValue(SubExpr); } // Check for pointer->pointer cast if (SubExpr->getType()->isPointerType()) return CheckAddressConstantExpression(SubExpr); if (SubExpr->getType()->isIntegralType()) { // Check for the special-case of a pointer->int->pointer cast; // this isn't standard, but some code requires it. See // PR2720 for an example. if (const CastExpr* SubCast = dyn_cast(SubExpr)) { if (SubCast->getSubExpr()->getType()->isPointerType()) { unsigned IntWidth = Context.getIntWidth(SubCast->getType()); unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); if (IntWidth >= PointerWidth) { return CheckAddressConstantExpression(SubCast->getSubExpr()); } } } } if (SubExpr->getType()->isArithmeticType()) { return CheckArithmeticConstantExpression(SubExpr); } Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::ConditionalOperatorClass: { // FIXME: Should we pedwarn here? const ConditionalOperator *Exp = cast(Init); if (!Exp->getCond()->getType()->isArithmeticType()) { Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } if (CheckArithmeticConstantExpression(Exp->getCond())) return true; if (Exp->getLHS() && CheckAddressConstantExpression(Exp->getLHS())) return true; return CheckAddressConstantExpression(Exp->getRHS()); } case Expr::AddrLabelExprClass: return false; } } static const Expr* FindExpressionBaseAddress(const Expr* E); static const Expr* FindExpressionBaseAddressLValue(const Expr* E) { switch (E->getStmtClass()) { default: return E; case Expr::ParenExprClass: { const ParenExpr* PE = cast(E); return FindExpressionBaseAddressLValue(PE->getSubExpr()); } case Expr::MemberExprClass: { const MemberExpr *M = cast(E); if (M->isArrow()) return FindExpressionBaseAddress(M->getBase()); return FindExpressionBaseAddressLValue(M->getBase()); } case Expr::ArraySubscriptExprClass: { const ArraySubscriptExpr *ASE = cast(E); return FindExpressionBaseAddress(ASE->getBase()); } case Expr::UnaryOperatorClass: { const UnaryOperator *Exp = cast(E); if (Exp->getOpcode() == UnaryOperator::Deref) return FindExpressionBaseAddress(Exp->getSubExpr()); return E; } } } static const Expr* FindExpressionBaseAddress(const Expr* E) { switch (E->getStmtClass()) { default: return E; case Expr::ParenExprClass: { const ParenExpr* PE = cast(E); return FindExpressionBaseAddress(PE->getSubExpr()); } case Expr::UnaryOperatorClass: { const UnaryOperator *Exp = cast(E); // C99 6.6p9 if (Exp->getOpcode() == UnaryOperator::AddrOf) return FindExpressionBaseAddressLValue(Exp->getSubExpr()); if (Exp->getOpcode() == UnaryOperator::Extension) return FindExpressionBaseAddress(Exp->getSubExpr()); return E; } case Expr::BinaryOperatorClass: { const BinaryOperator *Exp = cast(E); Expr *PExp = Exp->getLHS(); Expr *IExp = Exp->getRHS(); if (IExp->getType()->isPointerType()) std::swap(PExp, IExp); return FindExpressionBaseAddress(PExp); } case Expr::ImplicitCastExprClass: { const Expr* SubExpr = cast(E)->getSubExpr(); // Check for implicit promotion if (SubExpr->getType()->isFunctionType() || SubExpr->getType()->isArrayType()) return FindExpressionBaseAddressLValue(SubExpr); // Check for pointer->pointer cast if (SubExpr->getType()->isPointerType()) return FindExpressionBaseAddress(SubExpr); // We assume that we have an arithmetic expression here; // if we don't, we'll figure it out later return 0; } case Expr::ExplicitCastExprClass: { const Expr* SubExpr = cast(E)->getSubExpr(); // Check for pointer->pointer cast if (SubExpr->getType()->isPointerType()) return FindExpressionBaseAddress(SubExpr); // We assume that we have an arithmetic expression here; // if we don't, we'll figure it out later return 0; } } } bool Sema::CheckArithmeticConstantExpression(const Expr* Init) { switch (Init->getStmtClass()) { default: Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case Expr::ParenExprClass: { const ParenExpr* PE = cast(Init); return CheckArithmeticConstantExpression(PE->getSubExpr()); } case Expr::FloatingLiteralClass: case Expr::IntegerLiteralClass: case Expr::CharacterLiteralClass: case Expr::ImaginaryLiteralClass: case Expr::TypesCompatibleExprClass: case Expr::CXXBoolLiteralExprClass: return false; case Expr::CallExprClass: { const CallExpr *CE = cast(Init); if (CE->isBuiltinConstantExpr()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::DeclRefExprClass: { const Decl *D = cast(Init)->getDecl(); if (isa(D)) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::CompoundLiteralExprClass: // Allow "(vector type){2,4}"; normal C constraints don't allow this, // but vectors are allowed to be magic. if (Init->getType()->isVectorType()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case Expr::UnaryOperatorClass: { const UnaryOperator *Exp = cast(Init); switch (Exp->getOpcode()) { // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. // See C99 6.6p3. default: Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case UnaryOperator::SizeOf: case UnaryOperator::AlignOf: case UnaryOperator::OffsetOf: // sizeof(E) is a constantexpr if and only if E is not evaluted. // See C99 6.5.3.4p2 and 6.6p3. if (Exp->getSubExpr()->getType()->isConstantSizeType()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; case UnaryOperator::Extension: case UnaryOperator::LNot: case UnaryOperator::Plus: case UnaryOperator::Minus: case UnaryOperator::Not: return CheckArithmeticConstantExpression(Exp->getSubExpr()); } } case Expr::SizeOfAlignOfTypeExprClass: { const SizeOfAlignOfTypeExpr *Exp = cast(Init); // Special check for void types, which are allowed as an extension if (Exp->getArgumentType()->isVoidType()) return false; // alignof always evaluates to a constant. // FIXME: is sizeof(int[3.0]) a constant expression? if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) { Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } return false; } case Expr::BinaryOperatorClass: { const BinaryOperator *Exp = cast(Init); if (Exp->getLHS()->getType()->isArithmeticType() && Exp->getRHS()->getType()->isArithmeticType()) { return CheckArithmeticConstantExpression(Exp->getLHS()) || CheckArithmeticConstantExpression(Exp->getRHS()); } if (Exp->getLHS()->getType()->isPointerType() && Exp->getRHS()->getType()->isPointerType()) { const Expr* LHSBase = FindExpressionBaseAddress(Exp->getLHS()); const Expr* RHSBase = FindExpressionBaseAddress(Exp->getRHS()); // Only allow a null (constant integer) base; we could // allow some additional cases if necessary, but this // is sufficient to cover offsetof-like constructs. if (!LHSBase && !RHSBase) { return CheckAddressConstantExpression(Exp->getLHS()) || CheckAddressConstantExpression(Exp->getRHS()); } } Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::ImplicitCastExprClass: case Expr::ExplicitCastExprClass: { const Expr *SubExpr = cast(Init)->getSubExpr(); if (SubExpr->getType()->isArithmeticType()) return CheckArithmeticConstantExpression(SubExpr); if (SubExpr->getType()->isPointerType()) { const Expr* Base = FindExpressionBaseAddress(SubExpr); // If the pointer has a null base, this is an offsetof-like construct if (!Base) return CheckAddressConstantExpression(SubExpr); } Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } case Expr::ConditionalOperatorClass: { const ConditionalOperator *Exp = cast(Init); if (CheckArithmeticConstantExpression(Exp->getCond())) return true; if (Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) return true; return CheckArithmeticConstantExpression(Exp->getRHS()); } } } bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { Init = Init->IgnoreParens(); // Look through CXXDefaultArgExprs; they have no meaning in this context. if (CXXDefaultArgExpr* DAE = dyn_cast(Init)) return CheckForConstantInitializer(DAE->getExpr(), DclT); if (CompoundLiteralExpr *e = dyn_cast(Init)) return CheckForConstantInitializer(e->getInitializer(), DclT); if (Init->getType()->isReferenceType()) { // FIXME: Work out how the heck reference types work return false; #if 0 // A reference is constant if the address of the expression // is constant // We look through initlists here to simplify // CheckAddressConstantExpressionLValue. if (InitListExpr *Exp = dyn_cast(Init)) { assert(Exp->getNumInits() > 0 && "Refernce initializer cannot be empty"); Init = Exp->getInit(0); } return CheckAddressConstantExpressionLValue(Init); #endif } if (InitListExpr *Exp = dyn_cast(Init)) { unsigned numInits = Exp->getNumInits(); for (unsigned i = 0; i < numInits; i++) { // FIXME: Need to get the type of the declaration for C++, // because it could be a reference? if (CheckForConstantInitializer(Exp->getInit(i), Exp->getInit(i)->getType())) return true; } return false; } if (Init->isNullPointerConstant(Context)) return false; if (Init->getType()->isArithmeticType()) { QualType InitTy = Context.getCanonicalType(Init->getType()) .getUnqualifiedType(); if (InitTy == Context.BoolTy) { // Special handling for pointers implicitly cast to bool; // (e.g. "_Bool rr = &rr;"). This is only legal at the top level. if (ImplicitCastExpr* ICE = dyn_cast(Init)) { Expr* SubE = ICE->getSubExpr(); if (SubE->getType()->isPointerType() || SubE->getType()->isArrayType() || SubE->getType()->isFunctionType()) { return CheckAddressConstantExpression(Init); } } } else if (InitTy->isIntegralType()) { Expr* SubE = 0; if (CastExpr* CE = dyn_cast(Init)) SubE = CE->getSubExpr(); // Special check for pointer cast to int; we allow as an extension // an address constant cast to an integer if the integer // is of an appropriate width (this sort of code is apparently used // in some places). // FIXME: Add pedwarn? // FIXME: Don't allow bitfields here! Need the FieldDecl for that. if (SubE && (SubE->getType()->isPointerType() || SubE->getType()->isArrayType() || SubE->getType()->isFunctionType())) { unsigned IntWidth = Context.getTypeSize(Init->getType()); unsigned PointerWidth = Context.getTypeSize(Context.VoidPtrTy); if (IntWidth >= PointerWidth) return CheckAddressConstantExpression(Init); } } return CheckArithmeticConstantExpression(Init); } if (Init->getType()->isPointerType()) return CheckAddressConstantExpression(Init); // An array type at the top level that isn't an init-list must // be a string literal if (Init->getType()->isArrayType()) return false; if (Init->getType()->isFunctionType()) return false; Diag(Init->getExprLoc(), diag::err_init_element_not_constant, Init->getSourceRange()); return true; } void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) { Decl *RealDecl = static_cast(dcl); Expr *Init = static_cast(init); assert(Init && "missing initializer"); // If there is no declaration, there was an error parsing it. Just ignore // the initializer. if (RealDecl == 0) { delete Init; return; } VarDecl *VDecl = dyn_cast(RealDecl); if (!VDecl) { Diag(dyn_cast(RealDecl)->getLocation(), diag::err_illegal_initializer); RealDecl->setInvalidDecl(); return; } // Get the decls type and save a reference for later, since // CheckInitializerTypes may change it. QualType DclT = VDecl->getType(), SavT = DclT; if (VDecl->isBlockVarDecl()) { VarDecl::StorageClass SC = VDecl->getStorageClass(); if (SC == VarDecl::Extern) { // C99 6.7.8p5 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); VDecl->setInvalidDecl(); } else if (!VDecl->isInvalidDecl()) { if (CheckInitializerTypes(Init, DclT)) VDecl->setInvalidDecl(); // C++ 3.6.2p2, allow dynamic initialization of static initializers. if (!getLangOptions().CPlusPlus) { if (SC == VarDecl::Static) // C99 6.7.8p4. CheckForConstantInitializer(Init, DclT); } } } else if (VDecl->isFileVarDecl()) { if (VDecl->getStorageClass() == VarDecl::Extern) Diag(VDecl->getLocation(), diag::warn_extern_init); if (!VDecl->isInvalidDecl()) if (CheckInitializerTypes(Init, DclT)) VDecl->setInvalidDecl(); // C++ 3.6.2p2, allow dynamic initialization of static initializers. if (!getLangOptions().CPlusPlus) { // C99 6.7.8p4. All file scoped initializers need to be constant. CheckForConstantInitializer(Init, DclT); } } // If the type changed, it means we had an incomplete type that was // completed by the initializer. For example: // int ary[] = { 1, 3, 5 }; // "ary" transitions from a VariableArrayType to a ConstantArrayType. if (!VDecl->isInvalidDecl() && (DclT != SavT)) { VDecl->setType(DclT); Init->setType(DclT); } // Attach the initializer to the decl. VDecl->setInit(Init); return; } /// The declarators are chained together backwards, reverse the list. Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) { // Often we have single declarators, handle them quickly. Decl *GroupDecl = static_cast(group); if (GroupDecl == 0) return 0; ScopedDecl *Group = dyn_cast(GroupDecl); ScopedDecl *NewGroup = 0; if (Group->getNextDeclarator() == 0) NewGroup = Group; else { // reverse the list. while (Group) { ScopedDecl *Next = Group->getNextDeclarator(); Group->setNextDeclarator(NewGroup); NewGroup = Group; Group = Next; } } // Perform semantic analysis that depends on having fully processed both // the declarator and initializer. for (ScopedDecl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) { VarDecl *IDecl = dyn_cast(ID); if (!IDecl) continue; QualType T = IDecl->getType(); // C99 6.7.5.2p2: If an identifier is declared to be an object with // static storage duration, it shall not have a variable length array. if ((IDecl->isFileVarDecl() || IDecl->isBlockVarDecl()) && IDecl->getStorageClass() == VarDecl::Static) { if (T->isVariableArrayType()) { Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla); IDecl->setInvalidDecl(); } } // Block scope. C99 6.7p7: If an identifier for an object is declared with // no linkage (C99 6.2.2p6), the type for the object shall be complete... if (IDecl->isBlockVarDecl() && IDecl->getStorageClass() != VarDecl::Extern) { if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, T.getAsString()); IDecl->setInvalidDecl(); } } // File scope. C99 6.9.2p2: A declaration of an identifier for and // object that has file scope without an initializer, and without a // storage-class specifier or with the storage-class specifier "static", // constitutes a tentative definition. Note: A tentative definition with // external linkage is valid (C99 6.2.2p5). if (isTentativeDefinition(IDecl)) { if (T->isIncompleteArrayType()) { // C99 6.9.2 (p2, p5): Implicit initialization causes an incomplete // array to be completed. Don't issue a diagnostic. } else if (T->isIncompleteType() && !IDecl->isInvalidDecl()) { // C99 6.9.2p3: If the declaration of an identifier for an object is // a tentative definition and has internal linkage (C99 6.2.2p3), the // declared type shall not be an incomplete type. Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type, T.getAsString()); IDecl->setInvalidDecl(); } } if (IDecl->isFileVarDecl()) CheckForFileScopedRedefinitions(S, IDecl); } return NewGroup; } /// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() /// to introduce parameters into function prototype scope. Sema::DeclTy * Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { const DeclSpec &DS = D.getDeclSpec(); // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. VarDecl::StorageClass StorageClass = VarDecl::None; if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { StorageClass = VarDecl::Register; } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { Diag(DS.getStorageClassSpecLoc(), diag::err_invalid_storage_class_in_func_decl); D.getMutableDeclSpec().ClearStorageClassSpecs(); } if (DS.isThreadSpecified()) { Diag(DS.getThreadSpecLoc(), diag::err_invalid_storage_class_in_func_decl); D.getMutableDeclSpec().ClearStorageClassSpecs(); } // Check that there are no default arguments inside the type of this // parameter (C++ only). if (getLangOptions().CPlusPlus) CheckExtraCXXDefaultArguments(D); // In this context, we *do not* check D.getInvalidType(). If the declarator // type was invalid, GetTypeForDeclarator() still returns a "valid" type, // though it will not reflect the user specified type. QualType parmDeclType = GetTypeForDeclarator(D, S); assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type"); // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. // Can this happen for params? We already checked that they don't conflict // among each other. Here they can only shadow globals, which is ok. IdentifierInfo *II = D.getIdentifier(); if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) { if (S->isDeclScope(PrevDecl)) { Diag(D.getIdentifierLoc(), diag::err_param_redefinition, dyn_cast(PrevDecl)->getName()); // Recover by removing the name II = 0; D.SetIdentifier(0, D.getIdentifierLoc()); } } // Perform the default function/array conversion (C99 6.7.5.3p[7,8]). // Doing the promotion here has a win and a loss. The win is the type for // both Decl's and DeclRefExpr's will match (a convenient invariant for the // code generator). The loss is the orginal type isn't preserved. For example: // // void func(int parmvardecl[5]) { // convert "int [5]" to "int *" // int blockvardecl[5]; // sizeof(parmvardecl); // size == 4 // sizeof(blockvardecl); // size == 20 // } // // For expressions, all implicit conversions are captured using the // ImplicitCastExpr AST node (we have no such mechanism for Decl's). // // FIXME: If a source translation tool needs to see the original type, then // we need to consider storing both types (in ParmVarDecl)... // if (parmDeclType->isArrayType()) { // int x[restrict 4] -> int *restrict parmDeclType = Context.getArrayDecayedType(parmDeclType); } else if (parmDeclType->isFunctionType()) parmDeclType = Context.getPointerType(parmDeclType); ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, D.getIdentifierLoc(), II, parmDeclType, StorageClass, 0, 0); if (D.getInvalidType()) New->setInvalidDecl(); if (II) PushOnScopeChains(New, S); ProcessDeclAttributes(New, D); return New; } Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) { assert(getCurFunctionDecl() == 0 && "Function parsing confused"); assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && "Not a function declarator!"); DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' // for a K&R function. if (!FTI.hasPrototype) { for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { if (FTI.ArgInfo[i].Param == 0) { Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared, FTI.ArgInfo[i].Ident->getName()); // Implicitly declare the argument as type 'int' for lack of a better // type. DeclSpec DS; const char* PrevSpec; // unused DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc, PrevSpec); Declarator ParamD(DS, Declarator::KNRTypeListContext); ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc); FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD); } } } else { // FIXME: Diagnose arguments without names in C. } Scope *GlobalScope = FnBodyScope->getParent(); // See if this is a redefinition. Decl *PrevDcl = LookupDecl(D.getIdentifier(), Decl::IDNS_Ordinary, GlobalScope); if (PrevDcl && isDeclInScope(PrevDcl, CurContext)) { if (FunctionDecl *FD = dyn_cast(PrevDcl)) { const FunctionDecl *Definition; if (FD->getBody(Definition)) { Diag(D.getIdentifierLoc(), diag::err_redefinition, D.getIdentifier()->getName()); Diag(Definition->getLocation(), diag::err_previous_definition); } } } return ActOnStartOfFunctionDef(FnBodyScope, ActOnDeclarator(GlobalScope, D, 0)); } Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) { Decl *decl = static_cast(D); FunctionDecl *FD = cast(decl); PushDeclContext(FD); // Check the validity of our function parameters CheckParmsForFunctionDef(FD); // Introduce our parameters into the function scope for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { ParmVarDecl *Param = FD->getParamDecl(p); // If this has an identifier, add it to the scope stack. if (Param->getIdentifier()) PushOnScopeChains(Param, FnBodyScope); } return FD; } Sema::DeclTy *Sema::ActOnFinishFunctionBody(DeclTy *D, StmtTy *Body) { Decl *dcl = static_cast(D); if (FunctionDecl *FD = dyn_cast_or_null(dcl)) { FD->setBody((Stmt*)Body); assert(FD == getCurFunctionDecl() && "Function parsing confused"); } else if (ObjCMethodDecl *MD = dyn_cast_or_null(dcl)) { MD->setBody((Stmt*)Body); } else return 0; PopDeclContext(); // Verify and clean out per-function state. // Check goto/label use. for (llvm::DenseMap::iterator I = LabelMap.begin(), E = LabelMap.end(); I != E; ++I) { // Verify that we have no forward references left. If so, there was a goto // or address of a label taken, but no definition of it. Label fwd // definitions are indicated with a null substmt. if (I->second->getSubStmt() == 0) { LabelStmt *L = I->second; // Emit error. Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName()); // At this point, we have gotos that use the bogus label. Stitch it into // the function body so that they aren't leaked and that the AST is well // formed. if (Body) { L->setSubStmt(new NullStmt(L->getIdentLoc())); cast((Stmt*)Body)->push_back(L); } else { // The whole function wasn't parsed correctly, just delete this. delete L; } } } LabelMap.clear(); return D; } /// ImplicitlyDefineFunction - An undeclared identifier was used in a function /// call, forming a call to an implicitly defined function (per C99 6.5.1p2). ScopedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II, Scope *S) { // Extension in C99. Legal in C90, but warn about it. if (getLangOptions().C99) Diag(Loc, diag::ext_implicit_function_decl, II.getName()); else Diag(Loc, diag::warn_implicit_function_decl, II.getName()); // FIXME: handle stuff like: // void foo() { extern float X(); } // void bar() { X(); } <-- implicit decl for X in another scope. // Set a Declarator for the implicit definition: int foo(); const char *Dummy; DeclSpec DS; bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy); Error = Error; // Silence warning. assert(!Error && "Error setting up implicit decl!"); Declarator D(DS, Declarator::BlockContext); D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc)); D.SetIdentifier(&II, Loc); // Insert this function into translation-unit scope. DeclContext *PrevDC = CurContext; CurContext = Context.getTranslationUnitDecl(); FunctionDecl *FD = dyn_cast(static_cast(ActOnDeclarator(TUScope, D, 0))); FD->setImplicit(); CurContext = PrevDC; return FD; } TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, ScopedDecl *LastDeclarator) { assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); // Scope manipulation handled by caller. TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext, D.getIdentifierLoc(), D.getIdentifier(), T, LastDeclarator); if (D.getInvalidType()) NewTD->setInvalidDecl(); return NewTD; } /// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the /// former case, Name will be non-null. In the later case, Name will be null. /// TagType indicates what kind of tag this is. TK indicates whether this is a /// reference/declaration/definition of a tag. Sema::DeclTy *Sema::ActOnTag(Scope *S, unsigned TagType, TagKind TK, SourceLocation KWLoc, IdentifierInfo *Name, SourceLocation NameLoc, AttributeList *Attr) { // If this is a use of an existing tag, it must have a name. assert((Name != 0 || TK == TK_Definition) && "Nameless record must be a definition!"); TagDecl::TagKind Kind; switch (TagType) { default: assert(0 && "Unknown tag type!"); case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; case DeclSpec::TST_enum: Kind = TagDecl::TK_enum; break; } // Two code paths: a new one for structs/unions/classes where we create // separate decls for forward declarations, and an old (eventually to // be removed) code path for enums. if (Kind != TagDecl::TK_enum) return ActOnTagStruct(S, Kind, TK, KWLoc, Name, NameLoc, Attr); // If this is a named struct, check to see if there was a previous forward // declaration or definition. // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. ScopedDecl *PrevDecl = dyn_cast_or_null(LookupDecl(Name, Decl::IDNS_Tag, S)); if (PrevDecl) { assert((isa(PrevDecl) || isa(PrevDecl)) && "unexpected Decl type"); if (TagDecl *PrevTagDecl = dyn_cast(PrevDecl)) { // If this is a use of a previous tag, or if the tag is already declared // in the same scope (so that the definition/declaration completes or // rementions the tag), reuse the decl. if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { // Make sure that this wasn't declared as an enum and now used as a // struct or something similar. if (PrevTagDecl->getTagKind() != Kind) { Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_use); // Recover by making this an anonymous redefinition. Name = 0; PrevDecl = 0; } else { // If this is a use or a forward declaration, we're good. if (TK != TK_Definition) return PrevDecl; // Diagnose attempts to redefine a tag. if (PrevTagDecl->isDefinition()) { Diag(NameLoc, diag::err_redefinition, Name->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_definition); // If this is a redefinition, recover by making this struct be // anonymous, which will make any later references get the previous // definition. Name = 0; } else { // Okay, this is definition of a previously declared or referenced // tag. Move the location of the decl to be the definition site. PrevDecl->setLocation(NameLoc); return PrevDecl; } } } // If we get here, this is a definition of a new struct type in a nested // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new // type. } else { // PrevDecl is a namespace. if (isDeclInScope(PrevDecl, CurContext, S)) { // The tag name clashes with a namespace name, issue an error and // recover by making this tag be anonymous. Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_definition); Name = 0; } } } // If there is an identifier, use the location of the identifier as the // location of the decl, otherwise use the location of the struct/union // keyword. SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; // Otherwise, if this is the first time we've seen this tag, create the decl. TagDecl *New; if (Kind == TagDecl::TK_enum) { // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: // enum X { A, B, C } D; D should chain to X. New = EnumDecl::Create(Context, CurContext, Loc, Name, 0); // If this is an undefined enum, warn. if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum); } else { // struct/union/class // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: // struct X { int A; } D; D should chain to X. if (getLangOptions().CPlusPlus) // FIXME: Look for a way to use RecordDecl for simple structs. New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name); else New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name); } // If this has an identifier, add it to the scope stack. if (Name) { // The scope passed in may not be a decl scope. Zip up the scope tree until // we find one that is. while ((S->getFlags() & Scope::DeclScope) == 0) S = S->getParent(); // Add it to the decl chain. PushOnScopeChains(New, S); } if (Attr) ProcessDeclAttributeList(New, Attr); return New; } /// ActOnTagStruct - New "ActOnTag" logic for structs/unions/classes. Unlike /// the logic for enums, we create separate decls for forward declarations. /// This is called by ActOnTag, but eventually will replace its logic. Sema::DeclTy *Sema::ActOnTagStruct(Scope *S, TagDecl::TagKind Kind, TagKind TK, SourceLocation KWLoc, IdentifierInfo *Name, SourceLocation NameLoc, AttributeList *Attr) { // If this is a named struct, check to see if there was a previous forward // declaration or definition. // Use ScopedDecl instead of TagDecl, because a NamespaceDecl may come up. ScopedDecl *PrevDecl = dyn_cast_or_null(LookupDecl(Name, Decl::IDNS_Tag, S)); if (PrevDecl) { assert((isa(PrevDecl) || isa(PrevDecl)) && "unexpected Decl type"); if (TagDecl *PrevTagDecl = dyn_cast(PrevDecl)) { // If this is a use of a previous tag, or if the tag is already declared // in the same scope (so that the definition/declaration completes or // rementions the tag), reuse the decl. if (TK == TK_Reference || isDeclInScope(PrevDecl, CurContext, S)) { // Make sure that this wasn't declared as an enum and now used as a // struct or something similar. if (PrevTagDecl->getTagKind() != Kind) { Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_use); // Recover by making this an anonymous redefinition. Name = 0; PrevDecl = 0; } else { // If this is a use, return the original decl. // FIXME: In the future, return a variant or some other clue // for the consumer of this Decl to know it doesn't own it. // For our current ASTs this shouldn't be a problem, but will // need to be changed with DeclGroups. if (TK == TK_Reference) return PrevDecl; // The new decl is a definition? if (TK == TK_Definition) { // Diagnose attempts to redefine a tag. if (RecordDecl* DefRecord = cast(PrevTagDecl)->getDefinition(Context)) { Diag(NameLoc, diag::err_redefinition, Name->getName()); Diag(DefRecord->getLocation(), diag::err_previous_definition); // If this is a redefinition, recover by making this struct be // anonymous, which will make any later references get the previous // definition. Name = 0; PrevDecl = 0; } // Okay, this is definition of a previously declared or referenced // tag. We're going to create a new Decl. } } // If we get here we have (another) forward declaration. Just create // a new decl. } else { // If we get here, this is a definition of a new struct type in a nested // scope, e.g. "struct foo; void bar() { struct foo; }", just create a // new decl/type. We set PrevDecl to NULL so that the Records // have distinct types. PrevDecl = 0; } } else { // PrevDecl is a namespace. if (isDeclInScope(PrevDecl, CurContext, S)) { // The tag name clashes with a namespace name, issue an error and // recover by making this tag be anonymous. Diag(NameLoc, diag::err_redefinition_different_kind, Name->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_definition); Name = 0; } } } // If there is an identifier, use the location of the identifier as the // location of the decl, otherwise use the location of the struct/union // keyword. SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; // Otherwise, if this is the first time we've seen this tag, create the decl. TagDecl *New; // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: // struct X { int A; } D; D should chain to X. if (getLangOptions().CPlusPlus) // FIXME: Look for a way to use RecordDecl for simple structs. New = CXXRecordDecl::Create(Context, Kind, CurContext, Loc, Name, dyn_cast_or_null(PrevDecl)); else New = RecordDecl::Create(Context, Kind, CurContext, Loc, Name, dyn_cast_or_null(PrevDecl)); // If this has an identifier, add it to the scope stack. if ((TK == TK_Definition || !PrevDecl) && Name) { // The scope passed in may not be a decl scope. Zip up the scope tree until // we find one that is. while ((S->getFlags() & Scope::DeclScope) == 0) S = S->getParent(); // Add it to the decl chain. PushOnScopeChains(New, S); } if (Attr) ProcessDeclAttributeList(New, Attr); return New; } /// Collect the instance variables declared in an Objective-C object. Used in /// the creation of structures from objects using the @defs directive. static void CollectIvars(ObjCInterfaceDecl *Class, ASTContext& Ctx, llvm::SmallVectorImpl &ivars) { if (Class->getSuperClass()) CollectIvars(Class->getSuperClass(), Ctx, ivars); // For each ivar, create a fresh ObjCAtDefsFieldDecl. for (ObjCInterfaceDecl::ivar_iterator I=Class->ivar_begin(), E=Class->ivar_end(); I!=E; ++I) { ObjCIvarDecl* ID = *I; ivars.push_back(ObjCAtDefsFieldDecl::Create(Ctx, ID->getLocation(), ID->getIdentifier(), ID->getType(), ID->getBitWidth())); } } /// Called whenever @defs(ClassName) is encountered in the source. Inserts the /// instance variables of ClassName into Decls. void Sema::ActOnDefs(Scope *S, SourceLocation DeclStart, IdentifierInfo *ClassName, llvm::SmallVectorImpl &Decls) { // Check that ClassName is a valid class ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName); if (!Class) { Diag(DeclStart, diag::err_undef_interface, ClassName->getName()); return; } // Collect the instance variables CollectIvars(Class, Context, Decls); } QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) { // This method tries to turn a variable array into a constant // array even when the size isn't an ICE. This is necessary // for compatibility with code that depends on gcc's buggy // constant expression folding, like struct {char x[(int)(char*)2];} if (const VariableArrayType* VLATy = dyn_cast(T)) { APValue Result; if (VLATy->getSizeExpr() && VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isInt()) { llvm::APSInt &Res = Result.getInt(); if (Res > llvm::APSInt(Res.getBitWidth(), Res.isUnsigned())) return Context.getConstantArrayType(VLATy->getElementType(), Res, ArrayType::Normal, 0); } } return QualType(); } /// ActOnField - Each field of a struct/union/class is passed into this in order /// to create a FieldDecl object for it. Sema::DeclTy *Sema::ActOnField(Scope *S, SourceLocation DeclStart, Declarator &D, ExprTy *BitfieldWidth) { IdentifierInfo *II = D.getIdentifier(); Expr *BitWidth = (Expr*)BitfieldWidth; SourceLocation Loc = DeclStart; if (II) Loc = D.getIdentifierLoc(); // FIXME: Unnamed fields can be handled in various different ways, for // example, unnamed unions inject all members into the struct namespace! if (BitWidth) { // TODO: Validate. //printf("WARNING: BITFIELDS IGNORED!\n"); // 6.7.2.1p3 // 6.7.2.1p4 } else { // Not a bitfield. // validate II. } QualType T = GetTypeForDeclarator(D, S); assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); bool InvalidDecl = false; // C99 6.7.2.1p8: A member of a structure or union may have any type other // than a variably modified type. if (T->isVariablyModifiedType()) { QualType FixedTy = TryFixInvalidVariablyModifiedType(T); if (!FixedTy.isNull()) { Diag(Loc, diag::warn_illegal_constant_array_size, Loc); T = FixedTy; } else { // FIXME: This diagnostic needs work Diag(Loc, diag::err_typecheck_illegal_vla, Loc); InvalidDecl = true; } } // FIXME: Chain fielddecls together. FieldDecl *NewFD; if (getLangOptions().CPlusPlus) { // FIXME: Replace CXXFieldDecls with FieldDecls for simple structs. NewFD = CXXFieldDecl::Create(Context, cast(CurContext), Loc, II, T, BitWidth); if (II) PushOnScopeChains(NewFD, S); } else NewFD = FieldDecl::Create(Context, Loc, II, T, BitWidth); ProcessDeclAttributes(NewFD, D); if (D.getInvalidType() || InvalidDecl) NewFD->setInvalidDecl(); return NewFD; } /// TranslateIvarVisibility - Translate visibility from a token ID to an /// AST enum value. static ObjCIvarDecl::AccessControl TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { switch (ivarVisibility) { case tok::objc_private: return ObjCIvarDecl::Private; case tok::objc_public: return ObjCIvarDecl::Public; case tok::objc_protected: return ObjCIvarDecl::Protected; case tok::objc_package: return ObjCIvarDecl::Package; default: assert(false && "Unknown visitibility kind"); } } /// ActOnIvar - Each ivar field of an objective-c class is passed into this /// in order to create an IvarDecl object for it. Sema::DeclTy *Sema::ActOnIvar(Scope *S, SourceLocation DeclStart, Declarator &D, ExprTy *BitfieldWidth, tok::ObjCKeywordKind Visibility) { IdentifierInfo *II = D.getIdentifier(); Expr *BitWidth = (Expr*)BitfieldWidth; SourceLocation Loc = DeclStart; if (II) Loc = D.getIdentifierLoc(); // FIXME: Unnamed fields can be handled in various different ways, for // example, unnamed unions inject all members into the struct namespace! if (BitWidth) { // TODO: Validate. //printf("WARNING: BITFIELDS IGNORED!\n"); // 6.7.2.1p3 // 6.7.2.1p4 } else { // Not a bitfield. // validate II. } QualType T = GetTypeForDeclarator(D, S); assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); bool InvalidDecl = false; // C99 6.7.2.1p8: A member of a structure or union may have any type other // than a variably modified type. if (T->isVariablyModifiedType()) { // FIXME: This diagnostic needs work Diag(Loc, diag::err_typecheck_illegal_vla, Loc); InvalidDecl = true; } // Get the visibility (access control) for this ivar. ObjCIvarDecl::AccessControl ac = Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) : ObjCIvarDecl::None; // Construct the decl. ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, Loc, II, T, ac, (Expr *)BitfieldWidth); // Process attributes attached to the ivar. ProcessDeclAttributes(NewID, D); if (D.getInvalidType() || InvalidDecl) NewID->setInvalidDecl(); return NewID; } void Sema::ActOnFields(Scope* S, SourceLocation RecLoc, DeclTy *RecDecl, DeclTy **Fields, unsigned NumFields, SourceLocation LBrac, SourceLocation RBrac) { Decl *EnclosingDecl = static_cast(RecDecl); assert(EnclosingDecl && "missing record or interface decl"); RecordDecl *Record = dyn_cast(EnclosingDecl); if (Record) if (RecordDecl* DefRecord = Record->getDefinition(Context)) { // Diagnose code like: // struct S { struct S {} X; }; // We discover this when we complete the outer S. Reject and ignore the // outer S. Diag(DefRecord->getLocation(), diag::err_nested_redefinition, DefRecord->getKindName()); Diag(RecLoc, diag::err_previous_definition); Record->setInvalidDecl(); return; } // Verify that all the fields are okay. unsigned NumNamedMembers = 0; llvm::SmallVector RecFields; llvm::SmallSet FieldIDs; for (unsigned i = 0; i != NumFields; ++i) { FieldDecl *FD = cast_or_null(static_cast(Fields[i])); assert(FD && "missing field decl"); // Remember all fields. RecFields.push_back(FD); // Get the type for the field. Type *FDTy = FD->getType().getTypePtr(); // C99 6.7.2.1p2 - A field may not be a function type. if (FDTy->isFunctionType()) { Diag(FD->getLocation(), diag::err_field_declared_as_function, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } // C99 6.7.2.1p2 - A field may not be an incomplete type except... if (FDTy->isIncompleteType()) { if (!Record) { // Incomplete ivar type is always an error. Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } if (i != NumFields-1 || // ... that the last member ... !Record->isStruct() || // ... of a structure ... !FDTy->isArrayType()) { //... may have incomplete array type. Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } if (NumNamedMembers < 1) { //... must have more than named member ... Diag(FD->getLocation(), diag::err_flexible_array_empty_struct, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } // Okay, we have a legal flexible array member at the end of the struct. if (Record) Record->setHasFlexibleArrayMember(true); } /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the /// field of another structure or the element of an array. if (const RecordType *FDTTy = FDTy->getAsRecordType()) { if (FDTTy->getDecl()->hasFlexibleArrayMember()) { // If this is a member of a union, then entire union becomes "flexible". if (Record && Record->isUnion()) { Record->setHasFlexibleArrayMember(true); } else { // If this is a struct/class and this is not the last element, reject // it. Note that GCC supports variable sized arrays in the middle of // structures. if (i != NumFields-1) { Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } // We support flexible arrays at the end of structs in other structs // as an extension. Diag(FD->getLocation(), diag::ext_flexible_array_in_struct, FD->getName()); if (Record) Record->setHasFlexibleArrayMember(true); } } } /// A field cannot be an Objective-c object if (FDTy->isObjCInterfaceType()) { Diag(FD->getLocation(), diag::err_statically_allocated_object, FD->getName()); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } // Keep track of the number of named members. if (IdentifierInfo *II = FD->getIdentifier()) { // Detect duplicate member names. if (!FieldIDs.insert(II)) { Diag(FD->getLocation(), diag::err_duplicate_member, II->getName()); // Find the previous decl. SourceLocation PrevLoc; for (unsigned i = 0, e = RecFields.size(); ; ++i) { assert(i != e && "Didn't find previous def!"); if (RecFields[i]->getIdentifier() == II) { PrevLoc = RecFields[i]->getLocation(); break; } } Diag(PrevLoc, diag::err_previous_definition); FD->setInvalidDecl(); EnclosingDecl->setInvalidDecl(); continue; } ++NumNamedMembers; } } // Okay, we successfully defined 'Record'. if (Record) { Record->defineBody(Context, &RecFields[0], RecFields.size()); // If this is a C++ record, HandleTagDeclDefinition will be invoked in // Sema::ActOnFinishCXXClassDef. if (!isa(Record)) Consumer.HandleTagDeclDefinition(Record); } else { ObjCIvarDecl **ClsFields = reinterpret_cast(&RecFields[0]); if (ObjCInterfaceDecl *ID = dyn_cast(EnclosingDecl)) ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac); else if (ObjCImplementationDecl *IMPDecl = dyn_cast(EnclosingDecl)) { assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size()); CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); } } } Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl, DeclTy *lastEnumConst, SourceLocation IdLoc, IdentifierInfo *Id, SourceLocation EqualLoc, ExprTy *val) { EnumDecl *TheEnumDecl = cast(static_cast(theEnumDecl)); EnumConstantDecl *LastEnumConst = cast_or_null(static_cast(lastEnumConst)); Expr *Val = static_cast(val); // The scope passed in may not be a decl scope. Zip up the scope tree until // we find one that is. while ((S->getFlags() & Scope::DeclScope) == 0) S = S->getParent(); // Verify that there isn't already something declared with this name in this // scope. if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) { // When in C++, we may get a TagDecl with the same name; in this case the // enum constant will 'hide' the tag. assert((getLangOptions().CPlusPlus || !isa(PrevDecl)) && "Received TagDecl when not in C++!"); if (!isa(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { if (isa(PrevDecl)) Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName()); else Diag(IdLoc, diag::err_redefinition, Id->getName()); Diag(PrevDecl->getLocation(), diag::err_previous_definition); delete Val; return 0; } } llvm::APSInt EnumVal(32); QualType EltTy; if (Val) { // Make sure to promote the operand type to int. UsualUnaryConversions(Val); // C99 6.7.2.2p2: Make sure we have an integer constant expression. SourceLocation ExpLoc; if (!Val->isIntegerConstantExpr(EnumVal, Context, &ExpLoc)) { Diag(ExpLoc, diag::err_enum_value_not_integer_constant_expr, Id->getName()); delete Val; Val = 0; // Just forget about it. } else { EltTy = Val->getType(); } } if (!Val) { if (LastEnumConst) { // Assign the last value + 1. EnumVal = LastEnumConst->getInitVal(); ++EnumVal; // Check for overflow on increment. if (EnumVal < LastEnumConst->getInitVal()) Diag(IdLoc, diag::warn_enum_value_overflow); EltTy = LastEnumConst->getType(); } else { // First value, set to zero. EltTy = Context.IntTy; EnumVal.zextOrTrunc(static_cast(Context.getTypeSize(EltTy))); } } EnumConstantDecl *New = EnumConstantDecl::Create(Context, TheEnumDecl, IdLoc, Id, EltTy, Val, EnumVal, LastEnumConst); // Register this decl in the current scope stack. PushOnScopeChains(New, S); return New; } // FIXME: For consistency with ActOnFields(), we should have the parser // pass in the source location for the left/right braces. void Sema::ActOnEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX, DeclTy **Elements, unsigned NumElements) { EnumDecl *Enum = cast(static_cast(EnumDeclX)); if (Enum && Enum->isDefinition()) { // Diagnose code like: // enum e0 { // E0 = sizeof(enum e0 { E1 }) // }; Diag(Enum->getLocation(), diag::err_nested_redefinition, Enum->getName()); Diag(EnumLoc, diag::err_previous_definition); Enum->setInvalidDecl(); return; } // TODO: If the result value doesn't fit in an int, it must be a long or long // long value. ISO C does not support this, but GCC does as an extension, // emit a warning. unsigned IntWidth = Context.Target.getIntWidth(); // Verify that all the values are okay, compute the size of the values, and // reverse the list. unsigned NumNegativeBits = 0; unsigned NumPositiveBits = 0; // Keep track of whether all elements have type int. bool AllElementsInt = true; EnumConstantDecl *EltList = 0; for (unsigned i = 0; i != NumElements; ++i) { EnumConstantDecl *ECD = cast_or_null(static_cast(Elements[i])); if (!ECD) continue; // Already issued a diagnostic. // If the enum value doesn't fit in an int, emit an extension warning. const llvm::APSInt &InitVal = ECD->getInitVal(); assert(InitVal.getBitWidth() >= IntWidth && "Should have promoted value to int"); if (InitVal.getBitWidth() > IntWidth) { llvm::APSInt V(InitVal); V.trunc(IntWidth); V.extend(InitVal.getBitWidth()); if (V != InitVal) Diag(ECD->getLocation(), diag::ext_enum_value_not_int, InitVal.toString(10)); } // Keep track of the size of positive and negative values. if (InitVal.isUnsigned() || InitVal.isNonNegative()) NumPositiveBits = std::max(NumPositiveBits, (unsigned)InitVal.getActiveBits()); else NumNegativeBits = std::max(NumNegativeBits, (unsigned)InitVal.getMinSignedBits()); // Keep track of whether every enum element has type int (very commmon). if (AllElementsInt) AllElementsInt = ECD->getType() == Context.IntTy; ECD->setNextDeclarator(EltList); EltList = ECD; } // Figure out the type that should be used for this enum. // FIXME: Support attribute(packed) on enums and -fshort-enums. QualType BestType; unsigned BestWidth; if (NumNegativeBits) { // If there is a negative value, figure out the smallest integer type (of // int/long/longlong) that fits. if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { BestType = Context.IntTy; BestWidth = IntWidth; } else { BestWidth = Context.Target.getLongWidth(); if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) BestType = Context.LongTy; else { BestWidth = Context.Target.getLongLongWidth(); if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) Diag(Enum->getLocation(), diag::warn_enum_too_large); BestType = Context.LongLongTy; } } } else { // If there is no negative value, figure out which of uint, ulong, ulonglong // fits. if (NumPositiveBits <= IntWidth) { BestType = Context.UnsignedIntTy; BestWidth = IntWidth; } else if (NumPositiveBits <= (BestWidth = Context.Target.getLongWidth())) { BestType = Context.UnsignedLongTy; } else { BestWidth = Context.Target.getLongLongWidth(); assert(NumPositiveBits <= BestWidth && "How could an initializer get larger than ULL?"); BestType = Context.UnsignedLongLongTy; } } // Loop over all of the enumerator constants, changing their types to match // the type of the enum if needed. for (unsigned i = 0; i != NumElements; ++i) { EnumConstantDecl *ECD = cast_or_null(static_cast(Elements[i])); if (!ECD) continue; // Already issued a diagnostic. // Standard C says the enumerators have int type, but we allow, as an // extension, the enumerators to be larger than int size. If each // enumerator value fits in an int, type it as an int, otherwise type it the // same as the enumerator decl itself. This means that in "enum { X = 1U }" // that X has type 'int', not 'unsigned'. if (ECD->getType() == Context.IntTy) { // Make sure the init value is signed. llvm::APSInt IV = ECD->getInitVal(); IV.setIsSigned(true); ECD->setInitVal(IV); continue; // Already int type. } // Determine whether the value fits into an int. llvm::APSInt InitVal = ECD->getInitVal(); bool FitsInInt; if (InitVal.isUnsigned() || !InitVal.isNegative()) FitsInInt = InitVal.getActiveBits() < IntWidth; else FitsInInt = InitVal.getMinSignedBits() <= IntWidth; // If it fits into an integer type, force it. Otherwise force it to match // the enum decl type. QualType NewTy; unsigned NewWidth; bool NewSign; if (FitsInInt) { NewTy = Context.IntTy; NewWidth = IntWidth; NewSign = true; } else if (ECD->getType() == BestType) { // Already the right type! continue; } else { NewTy = BestType; NewWidth = BestWidth; NewSign = BestType->isSignedIntegerType(); } // Adjust the APSInt value. InitVal.extOrTrunc(NewWidth); InitVal.setIsSigned(NewSign); ECD->setInitVal(InitVal); // Adjust the Expr initializer and type. ECD->setInitExpr(new ImplicitCastExpr(NewTy, ECD->getInitExpr())); ECD->setType(NewTy); } Enum->defineElements(EltList, BestType); Consumer.HandleTagDeclDefinition(Enum); } Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc, ExprTy *expr) { StringLiteral *AsmString = cast((Expr*)expr); return FileScopeAsmDecl::Create(Context, Loc, AsmString); } Sema::DeclTy* Sema::ActOnLinkageSpec(SourceLocation Loc, SourceLocation LBrace, SourceLocation RBrace, const char *Lang, unsigned StrSize, DeclTy *D) { LinkageSpecDecl::LanguageIDs Language; Decl *dcl = static_cast(D); if (strncmp(Lang, "\"C\"", StrSize) == 0) Language = LinkageSpecDecl::lang_c; else if (strncmp(Lang, "\"C++\"", StrSize) == 0) Language = LinkageSpecDecl::lang_cxx; else { Diag(Loc, diag::err_bad_language); return 0; } // FIXME: Add all the various semantics of linkage specifications return LinkageSpecDecl::Create(Context, Loc, Language, dcl); }