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llvm-project/clang/lib/Sema/SemaDecl.cpp

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//===--- 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(IdentifierInfo &II, Scope *S,
const CXXScopeSpec *SS) {
DeclContext *DC = 0;
if (SS) {
if (SS->isInvalid())
return 0;
DC = static_cast<DeclContext*>(SS->getScopeRep());
}
Decl *IIDecl = LookupDecl(&II, Decl::IDNS_Ordinary, S, DC, false);
if (IIDecl && (isa<TypedefDecl>(IIDecl) ||
isa<ObjCInterfaceDecl>(IIDecl) ||
isa<TagDecl>(IIDecl)))
return IIDecl;
return 0;
}
DeclContext *Sema::getContainingDC(DeclContext *DC) {
if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) {
// A C++ out-of-line method will return to the file declaration context.
if (MD->isOutOfLineDefinition())
return MD->getLexicalDeclContext();
// 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 lexically declared in.
assert(isa<CXXRecordDecl>(MD->getParent()) && "C++ method not in Record.");
DC = MD->getParent();
while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent()))
DC = RD;
// Return the declaration context of the topmost class the inline method is
// declared in.
return DC;
}
if (isa<ObjCMethodDecl>(DC))
return Context.getTranslationUnitDecl();
if (ScopedDecl *SD = dyn_cast<ScopedDecl>(DC))
return SD->getLexicalDeclContext();
return DC->getLexicalParent();
}
void Sema::PushDeclContext(DeclContext *DC) {
assert(getContainingDC(DC) == CurContext &&
"The next DeclContext should be lexically contained in the current one.");
CurContext = DC;
}
void Sema::PopDeclContext() {
assert(CurContext && "DeclContext imbalance!");
CurContext = getContainingDC(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<TagDecl>(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;
}
} else if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) {
FunctionDecl *FD = cast<FunctionDecl>(D);
// We are pushing the name of a function, which might be an
// overloaded name.
IdentifierResolver::iterator
I = IdResolver.begin(FD->getDeclName(),
FD->getDeclContext(), false/*LookInParentCtx*/);
if (I != IdResolver.end() &&
IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) &&
(isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) {
// There is already a declaration with the same name in the same
// scope. It must be a function or an overloaded function.
OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I);
if (!Ovl) {
// We haven't yet overloaded this function. Take the existing
// FunctionDecl and put it into an OverloadedFunctionDecl.
Ovl = OverloadedFunctionDecl::Create(Context,
FD->getDeclContext(),
FD->getDeclName());
Ovl->addOverload(dyn_cast<FunctionDecl>(*I));
// Remove the name binding to the existing FunctionDecl...
IdResolver.RemoveDecl(*I);
// ... and put the OverloadedFunctionDecl in its place.
IdResolver.AddDecl(Ovl);
}
// We have an OverloadedFunctionDecl. Add the new FunctionDecl
// to its list of overloads.
Ovl->addOverload(FD);
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<Decl*>(*I);
assert(TmpD && "This decl didn't get pushed??");
if (isa<CXXFieldDecl>(TmpD)) continue;
assert(isa<ScopedDecl>(TmpD) && "Decl isn't ScopedDecl?");
ScopedDecl *D = cast<ScopedDecl>(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<ObjCInterfaceDecl>(IDecl);
}
/// LookupDecl - Look up the inner-most declaration in the specified
/// namespace.
Decl *Sema::LookupDecl(DeclarationName Name, unsigned NSI, Scope *S,
const DeclContext *LookupCtx,
bool enableLazyBuiltinCreation) {
if (!Name) return 0;
unsigned NS = NSI;
if (getLangOptions().CPlusPlus && (NS & Decl::IDNS_Ordinary))
NS |= Decl::IDNS_Tag;
IdentifierResolver::iterator
I = LookupCtx ? IdResolver.begin(Name, LookupCtx, false/*LookInParentCtx*/)
: IdResolver.begin(Name, CurContext, true/*LookInParentCtx*/);
// 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 (; I != IdResolver.end(); ++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) {
IdentifierInfo *II = Name.getAsIdentifierInfo();
if (enableLazyBuiltinCreation && II &&
(LookupCtx == 0 || isa<TranslationUnitDecl>(LookupCtx))) {
// 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 && II) {
// @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<TypedefDecl>(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<FunctionTypeProto>(R)) {
llvm::SmallVector<ParmVarDecl*, 16> 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;
}
/// GetStdNamespace - This method gets the C++ "std" namespace. This is where
/// everything from the standard library is defined.
NamespaceDecl *Sema::GetStdNamespace() {
if (!StdNamespace) {
IdentifierInfo *StdIdent = &PP.getIdentifierTable().get("std");
DeclContext *Global = Context.getTranslationUnitDecl();
Decl *Std = LookupDecl(StdIdent, Decl::IDNS_Tag | Decl::IDNS_Ordinary,
0, Global, /*enableLazyBuiltinCreation=*/false);
StdNamespace = dyn_cast_or_null<NamespaceDecl>(Std);
}
return StdNamespace;
}
/// 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 *TypeID = New->getIdentifier();
switch (TypeID->getLength()) {
default: break;
case 2:
if (!TypeID->isStr("id"))
break;
Context.setObjCIdType(New);
return New;
case 5:
if (!TypeID->isStr("Class"))
break;
Context.setObjCClassType(New);
return New;
case 3:
if (!TypeID->isStr("SEL"))
break;
Context.setObjCSelType(New);
return New;
case 8:
if (!TypeID->isStr("Protocol"))
break;
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<TypedefDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
Diag(OldD->getLocation(), diag::note_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::note_previous_definition);
return Old;
}
if (getLangOptions().Microsoft) return New;
// C++ [dcl.typedef]p2:
// In a given non-class scope, a typedef specifier can be used to
// redefine the name of any type declared in that scope to refer
// to the type to which it already refers.
if (getLangOptions().CPlusPlus && !isa<CXXRecordDecl>(CurContext))
return New;
// In C, 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->getDeclName();
Diag(Old->getLocation(), diag::note_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<Attr*>(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 this New is a redeclaration OldD.
///
/// In C++, New and Old must be declarations that are not
/// overloaded. Use IsOverload to determine whether New and Old are
/// overloaded, and to select the Old declaration that New should be
/// merged with.
FunctionDecl *
Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) {
assert(!isa<OverloadedFunctionDecl>(OldD) &&
"Cannot merge with an overloaded function declaration");
Redeclaration = false;
// Verify the old decl was also a function.
FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
Diag(OldD->getLocation(), diag::note_previous_definition);
return New;
}
// Determine whether the previous declaration was a definition,
// implicit declaration, or a declaration.
diag::kind PrevDiag;
if (Old->isThisDeclarationADefinition())
PrevDiag = diag::note_previous_definition;
else if (Old->isImplicit())
PrevDiag = diag::note_previous_implicit_declaration;
else
PrevDiag = diag::note_previous_declaration;
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
if (getLangOptions().CPlusPlus) {
// (C++98 13.1p2):
// Certain function declarations cannot be overloaded:
// -- Function declarations that differ only in the return type
// cannot be overloaded.
QualType OldReturnType
= cast<FunctionType>(OldQType.getTypePtr())->getResultType();
QualType NewReturnType
= cast<FunctionType>(NewQType.getTypePtr())->getResultType();
if (OldReturnType != NewReturnType) {
Diag(New->getLocation(), diag::err_ovl_diff_return_type);
Diag(Old->getLocation(), PrevDiag);
return New;
}
const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
if (OldMethod && NewMethod) {
// -- Member function declarations with the same name and the
// same parameter types cannot be overloaded if any of them
// is a static member function declaration.
if (OldMethod->isStatic() || NewMethod->isStatic()) {
Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
Diag(Old->getLocation(), PrevDiag);
return New;
}
}
// (C++98 8.3.5p3):
// All declarations for a function shall agree exactly in both the
// return type and the parameter-type-list.
if (OldQType == NewQType) {
// We have a redeclaration.
MergeAttributes(New, Old);
Redeclaration = true;
return MergeCXXFunctionDecl(New, Old);
}
// Fall through for conflicting redeclarations and redefinitions.
}
// 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
// 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->getDeclName();
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<VarDecl>(*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->getDeclName();
Diag(OldDecl->getLocation(), diag::note_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<VarDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind)
<< New->getDeclName();
Diag(OldD->getLocation(), diag::note_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->getDeclName();
Diag(Old->getLocation(), diag::note_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->getDeclName();
Diag(Old->getLocation(), diag::note_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->getDeclName();
Diag(Old->getLocation(), diag::note_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->getDeclName();
Diag(Old->getLocation(), diag::note_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();
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<TagDecl>(static_cast<Decl *>(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<IncompleteArrayType>(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<ConstantArrayType>(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<StringLiteral>(Init);
}
return 0;
}
bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType,
SourceLocation InitLoc,
DeclarationName InitEntity) {
// C++ [dcl.init.ref]p1:
// A variable declared to be a T&, that is<69> "reference to type T<>"
// (8.3.2), shall be initialized by an object, or function, of
// type T or by an object that can be converted into a T.
if (DeclType->isReferenceType())
return CheckReferenceInit(Init, 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(InitLoc, diag::err_variable_object_no_init)
<< VAT->getSizeExpr()->getSourceRange();
InitListExpr *InitList = dyn_cast<InitListExpr>(Init);
if (!InitList) {
// FIXME: Handle wide strings
if (StringLiteral *strLiteral = IsStringLiteralInit(Init, DeclType))
return CheckStringLiteralInit(strLiteral, DeclType);
// C++ [dcl.init]p14:
// -- If the destination type is a (possibly cv-qualified) class
// type:
if (getLangOptions().CPlusPlus && DeclType->isRecordType()) {
QualType DeclTypeC = Context.getCanonicalType(DeclType);
QualType InitTypeC = Context.getCanonicalType(Init->getType());
// -- If the initialization is direct-initialization, or if it is
// copy-initialization where the cv-unqualified version of the
// source type is the same class as, or a derived class of, the
// class of the destination, constructors are considered.
if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) ||
IsDerivedFrom(InitTypeC, DeclTypeC)) {
CXXConstructorDecl *Constructor
= PerformInitializationByConstructor(DeclType, &Init, 1,
InitLoc, Init->getSourceRange(),
InitEntity, IK_Copy);
return Constructor == 0;
}
// -- Otherwise (i.e., for the remaining copy-initialization
// cases), user-defined conversion sequences that can
// convert from the source type to the destination type or
// (when a conversion function is used) to a derived class
// thereof are enumerated as described in 13.3.1.4, and the
// best one is chosen through overload resolution
// (13.3). If the conversion cannot be done or is
// ambiguous, the initialization is ill-formed. The
// function selected is called with the initializer
// expression as its argument; if the function is a
// constructor, the call initializes a temporary of the
// destination type.
// FIXME: We're pretending to do copy elision here; return to
// this when we have ASTs for such things.
if (!PerformImplicitConversion(Init, DeclType))
return false;
return Diag(InitLoc, diag::err_typecheck_convert_incompatible)
<< DeclType << InitEntity << "initializing"
<< Init->getSourceRange();
}
// C99 6.7.8p16.
if (DeclType->isArrayType())
return Diag(Init->getLocStart(), diag::err_array_init_list_required)
<< Init->getSourceRange();
return CheckSingleInitializer(Init, DeclType);
} else if (getLangOptions().CPlusPlus) {
// C++ [dcl.init]p14:
// [...] If the class is an aggregate (8.5.1), and the initializer
// is a brace-enclosed list, see 8.5.1.
//
// Note: 8.5.1 is handled below; here, we diagnose the case where
// we have an initializer list and a destination type that is not
// an aggregate.
// FIXME: In C++0x, this is yet another form of initialization.
if (const RecordType *ClassRec = DeclType->getAsRecordType()) {
const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl());
if (!ClassDecl->isAggregate())
return Diag(InitLoc, diag::err_init_non_aggr_init_list)
<< DeclType.getAsString() << Init->getSourceRange();
}
}
InitListChecker CheckInitList(this, InitList, DeclType);
return CheckInitList.HadError();
}
/// GetNameForDeclarator - Determine the full declaration name for the
/// given Declarator.
DeclarationName Sema::GetNameForDeclarator(Declarator &D) {
switch (D.getKind()) {
case Declarator::DK_Abstract:
assert(D.getIdentifier() == 0 && "abstract declarators have no name");
return DeclarationName();
case Declarator::DK_Normal:
assert (D.getIdentifier() != 0 && "normal declarators have an identifier");
return DeclarationName(D.getIdentifier());
case Declarator::DK_Constructor: {
QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType());
Ty = Context.getCanonicalType(Ty);
return Context.DeclarationNames.getCXXConstructorName(Ty);
}
case Declarator::DK_Destructor: {
QualType Ty = Context.getTypeDeclType((TypeDecl *)D.getDeclaratorIdType());
Ty = Context.getCanonicalType(Ty);
return Context.DeclarationNames.getCXXDestructorName(Ty);
}
case Declarator::DK_Conversion: {
QualType Ty = QualType::getFromOpaquePtr(D.getDeclaratorIdType());
Ty = Context.getCanonicalType(Ty);
return Context.DeclarationNames.getCXXConversionFunctionName(Ty);
}
case Declarator::DK_Operator:
assert(D.getIdentifier() == 0 && "operator names have no identifier");
return Context.DeclarationNames.getCXXOperatorName(
D.getOverloadedOperator());
}
assert(false && "Unknown name kind");
return DeclarationName();
}
Sema::DeclTy *
Sema::ActOnDeclarator(Scope *S, Declarator &D, DeclTy *lastDecl) {
ScopedDecl *LastDeclarator = dyn_cast_or_null<ScopedDecl>((Decl *)lastDecl);
DeclarationName Name = GetNameForDeclarator(D);
// All of these full declarators require an identifier. If it doesn't have
// one, the ParsedFreeStandingDeclSpec action should be used.
if (!Name) {
if (!D.getInvalidType()) // Reject this if we think it is valid.
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();
DeclContext *DC;
Decl *PrevDecl;
ScopedDecl *New;
bool InvalidDecl = false;
// See if this is a redefinition of a variable in the same scope.
if (!D.getCXXScopeSpec().isSet()) {
DC = CurContext;
PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S);
} else { // Something like "int foo::x;"
DC = static_cast<DeclContext*>(D.getCXXScopeSpec().getScopeRep());
PrevDecl = LookupDecl(Name, Decl::IDNS_Ordinary, S, DC);
// C++ 7.3.1.2p2:
// Members (including explicit specializations of templates) of a named
// namespace can also be defined outside that namespace by explicit
// qualification of the name being defined, provided that the entity being
// defined was already declared in the namespace and the definition appears
// after the point of declaration in a namespace that encloses the
// declarations namespace.
//
if (PrevDecl == 0) {
// No previous declaration in the qualifying scope.
Diag(D.getIdentifierLoc(), diag::err_typecheck_no_member)
<< Name << D.getCXXScopeSpec().getRange();
} else if (!CurContext->Encloses(DC)) {
// The qualifying scope doesn't enclose the original declaration.
// Emit diagnostic based on current scope.
SourceLocation L = D.getIdentifierLoc();
SourceRange R = D.getCXXScopeSpec().getRange();
if (isa<FunctionDecl>(CurContext)) {
Diag(L, diag::err_invalid_declarator_in_function) << Name << R;
} else {
Diag(L, diag::err_invalid_declarator_scope)
<< Name << cast<NamedDecl>(DC)->getDeclName() << R;
}
}
}
// 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, DC, 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:
case DeclSpec::SCS_mutable:
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();
// bool isVirtual = D.getDeclSpec().isVirtualSpecified();
bool isExplicit = D.getDeclSpec().isExplicitSpecified();
FunctionDecl *NewFD;
if (D.getKind() == Declarator::DK_Constructor) {
// This is a C++ constructor declaration.
assert(DC->isCXXRecord() &&
"Constructors can only be declared in a member context");
bool isInvalidDecl = CheckConstructorDeclarator(D, R, SC);
// Create the new declaration
NewFD = CXXConstructorDecl::Create(Context,
cast<CXXRecordDecl>(DC),
D.getIdentifierLoc(), Name, R,
isExplicit, isInline,
/*isImplicitlyDeclared=*/false);
if (isInvalidDecl)
NewFD->setInvalidDecl();
} else if (D.getKind() == Declarator::DK_Destructor) {
// This is a C++ destructor declaration.
if (DC->isCXXRecord()) {
bool isInvalidDecl = CheckDestructorDeclarator(D, R, SC);
NewFD = CXXDestructorDecl::Create(Context,
cast<CXXRecordDecl>(DC),
D.getIdentifierLoc(), Name, R,
isInline,
/*isImplicitlyDeclared=*/false);
if (isInvalidDecl)
NewFD->setInvalidDecl();
} else {
Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
// Create a FunctionDecl to satisfy the function definition parsing
// code path.
NewFD = FunctionDecl::Create(Context, DC, D.getIdentifierLoc(),
Name, R, SC, isInline, LastDeclarator,
// FIXME: Move to DeclGroup...
D.getDeclSpec().getSourceRange().getBegin());
NewFD->setInvalidDecl();
}
} else if (D.getKind() == Declarator::DK_Conversion) {
if (!DC->isCXXRecord()) {
Diag(D.getIdentifierLoc(),
diag::err_conv_function_not_member);
return 0;
} else {
bool isInvalidDecl = CheckConversionDeclarator(D, R, SC);
NewFD = CXXConversionDecl::Create(Context,
cast<CXXRecordDecl>(DC),
D.getIdentifierLoc(), Name, R,
isInline, isExplicit);
if (isInvalidDecl)
NewFD->setInvalidDecl();
}
} else if (DC->isCXXRecord()) {
// This is a C++ method declaration.
NewFD = CXXMethodDecl::Create(Context, cast<CXXRecordDecl>(DC),
D.getIdentifierLoc(), Name, R,
(SC == FunctionDecl::Static), isInline,
LastDeclarator);
} else {
NewFD = FunctionDecl::Create(Context, DC,
D.getIdentifierLoc(),
Name, R, SC, isInline, LastDeclarator,
// FIXME: Move to DeclGroup...
D.getDeclSpec().getSourceRange().getBegin());
}
// 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<StringLiteral>(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<ParmVarDecl*, 16> 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());
} else if (R->getAsTypedefType()) {
// When we're declaring a function with a typedef, as in the
// following example, we'll need to synthesize (unnamed)
// parameters for use in the declaration.
//
// @code
// typedef void fn(int);
// fn f;
// @endcode
const FunctionTypeProto *FT = R->getAsFunctionTypeProto();
if (!FT) {
// This is a typedef of a function with no prototype, so we
// don't need to do anything.
} else if ((FT->getNumArgs() == 0) ||
(FT->getNumArgs() == 1 && !FT->isVariadic() &&
FT->getArgType(0)->isVoidType())) {
// This is a zero-argument function. We don't need to do anything.
} else {
// Synthesize a parameter for each argument type.
llvm::SmallVector<ParmVarDecl*, 16> Params;
for (FunctionTypeProto::arg_type_iterator ArgType = FT->arg_type_begin();
ArgType != FT->arg_type_end(); ++ArgType) {
Params.push_back(ParmVarDecl::Create(Context, DC,
SourceLocation(), 0,
*ArgType, VarDecl::None,
0, 0));
}
NewFD->setParams(&Params[0], Params.size());
}
}
// C++ constructors and destructors are handled by separate
// routines, since they don't require any declaration merging (C++
// [class.mfct]p2) and they aren't ever pushed into scope, because
// they can't be found by name lookup anyway (C++ [class.ctor]p2).
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD))
return ActOnConstructorDeclarator(Constructor);
else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(NewFD))
return ActOnDestructorDeclarator(Destructor);
// Extra checking for conversion functions, including recording
// the conversion function in its class.
if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD))
ActOnConversionDeclarator(Conversion);
// Extra checking for C++ overloaded operators (C++ [over.oper]).
if (NewFD->isOverloadedOperator() &&
CheckOverloadedOperatorDeclaration(NewFD))
NewFD->setInvalidDecl();
// 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, DC, S))) {
bool Redeclaration = false;
// If C++, determine whether NewFD is an overload of PrevDecl or
// a declaration that requires merging. If it's an overload,
// there's no more work to do here; we'll just add the new
// function to the scope.
OverloadedFunctionDecl::function_iterator MatchedDecl;
if (!getLangOptions().CPlusPlus ||
!IsOverload(NewFD, PrevDecl, MatchedDecl)) {
Decl *OldDecl = PrevDecl;
// If PrevDecl was an overloaded function, extract the
// FunctionDecl that matched.
if (isa<OverloadedFunctionDecl>(PrevDecl))
OldDecl = *MatchedDecl;
// NewFD and PrevDecl represent declarations that need to be
// merged.
NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration);
if (NewFD == 0) return 0;
if (Redeclaration) {
NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
if (OldDecl == PrevDecl) {
// Remove the name binding for the previous
// declaration. We'll add the binding back later, but then
// it will refer to the new declaration (which will
// contain more information).
IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl));
} else {
// We need to update the OverloadedFunctionDecl with the
// latest declaration of this function, so that name
// lookup will always refer to the latest declaration of
// this function.
*MatchedDecl = NewFD;
// Add the redeclaration to the current scope, since we'll
// be skipping PushOnScopeChains.
S->AddDecl(NewFD);
return NewFD;
}
}
}
}
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();
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;
case DeclSpec::SCS_mutable:
// mutable can only appear on non-static class members, so it's always
// an error here
Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
InvalidDecl = true;
break;
}
IdentifierInfo *II = Name.getAsIdentifierInfo();
if (!II) {
Diag(D.getIdentifierLoc(), diag::err_bad_variable_name)
<< Name.getAsString();
return 0;
}
if (DC->isCXXRecord()) {
assert(SC == VarDecl::Static && "Invalid storage class for member!");
// This is a static data member for a C++ class.
NewVD = CXXClassVarDecl::Create(Context, cast<CXXRecordDecl>(DC),
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, DC, D.getIdentifierLoc(),
II, R, SC, LastDeclarator,
// FIXME: Move to DeclGroup...
D.getDeclSpec().getSourceRange().getBegin());
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<StringLiteral>(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, DC, S)) {
NewVD = MergeVarDecl(NewVD, PrevDecl);
if (NewVD == 0) return 0;
}
New = NewVD;
}
// Set the lexical context. If the declarator has a C++ scope specifier, the
// lexical context will be different from the semantic context.
New->setLexicalDeclContext(CurContext);
// If this has an identifier, add it to the scope stack.
if (Name)
PushOnScopeChains(New, S);
// If any semantic error occurred, mark the decl as invalid.
if (D.getInvalidType() || InvalidDecl)
New->setInvalidDecl();
return New;
}
void Sema::InitializerElementNotConstant(const Expr *Init) {
Diag(Init->getExprLoc(), diag::err_init_element_not_constant)
<< Init->getSourceRange();
}
bool Sema::CheckAddressConstantExpressionLValue(const Expr* Init) {
switch (Init->getStmtClass()) {
default:
InitializerElementNotConstant(Init);
return true;
case Expr::ParenExprClass: {
const ParenExpr* PE = cast<ParenExpr>(Init);
return CheckAddressConstantExpressionLValue(PE->getSubExpr());
}
case Expr::CompoundLiteralExprClass:
return cast<CompoundLiteralExpr>(Init)->isFileScope();
case Expr::DeclRefExprClass: {
const Decl *D = cast<DeclRefExpr>(Init)->getDecl();
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
if (VD->hasGlobalStorage())
return false;
InitializerElementNotConstant(Init);
return true;
}
if (isa<FunctionDecl>(D))
return false;
InitializerElementNotConstant(Init);
return true;
}
case Expr::MemberExprClass: {
const MemberExpr *M = cast<MemberExpr>(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<ArraySubscriptExpr>(Init);
return CheckAddressConstantExpression(ASE->getBase()) ||
CheckArithmeticConstantExpression(ASE->getIdx());
}
case Expr::StringLiteralClass:
case Expr::PredefinedExprClass:
return false;
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(Init);
// C99 6.6p9
if (Exp->getOpcode() == UnaryOperator::Deref)
return CheckAddressConstantExpression(Exp->getSubExpr());
InitializerElementNotConstant(Init);
return true;
}
}
}
bool Sema::CheckAddressConstantExpression(const Expr* Init) {
switch (Init->getStmtClass()) {
default:
InitializerElementNotConstant(Init);
return true;
case Expr::ParenExprClass:
return CheckAddressConstantExpression(cast<ParenExpr>(Init)->getSubExpr());
case Expr::StringLiteralClass:
case Expr::ObjCStringLiteralClass:
return false;
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass:
// __builtin___CFStringMakeConstantString is a valid constant l-value.
if (cast<CallExpr>(Init)->isBuiltinCall() ==
Builtin::BI__builtin___CFStringMakeConstantString)
return false;
InitializerElementNotConstant(Init);
return true;
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(Init);
// C99 6.6p9
if (Exp->getOpcode() == UnaryOperator::AddrOf)
return CheckAddressConstantExpressionLValue(Exp->getSubExpr());
if (Exp->getOpcode() == UnaryOperator::Extension)
return CheckAddressConstantExpression(Exp->getSubExpr());
InitializerElementNotConstant(Init);
return true;
}
case Expr::BinaryOperatorClass: {
// FIXME: Should we pedwarn for expressions like "a + 1 + 2"?
const BinaryOperator *Exp = cast<BinaryOperator>(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::CStyleCastExprClass: {
const Expr* SubExpr = cast<CastExpr>(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<CastExpr>(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);
}
InitializerElementNotConstant(Init);
return true;
}
case Expr::ConditionalOperatorClass: {
// FIXME: Should we pedwarn here?
const ConditionalOperator *Exp = cast<ConditionalOperator>(Init);
if (!Exp->getCond()->getType()->isArithmeticType()) {
InitializerElementNotConstant(Init);
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<ParenExpr>(E);
return FindExpressionBaseAddressLValue(PE->getSubExpr());
}
case Expr::MemberExprClass: {
const MemberExpr *M = cast<MemberExpr>(E);
if (M->isArrow())
return FindExpressionBaseAddress(M->getBase());
return FindExpressionBaseAddressLValue(M->getBase());
}
case Expr::ArraySubscriptExprClass: {
const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(E);
return FindExpressionBaseAddress(ASE->getBase());
}
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(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<ParenExpr>(E);
return FindExpressionBaseAddress(PE->getSubExpr());
}
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(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<BinaryOperator>(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<ImplicitCastExpr>(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::CStyleCastExprClass: {
const Expr* SubExpr = cast<CastExpr>(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:
InitializerElementNotConstant(Init);
return true;
case Expr::ParenExprClass: {
const ParenExpr* PE = cast<ParenExpr>(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:
case Expr::CXXOperatorCallExprClass: {
const CallExpr *CE = cast<CallExpr>(Init);
// Allow any constant foldable calls to builtins.
if (CE->isBuiltinCall() && CE->isEvaluatable(Context))
return false;
InitializerElementNotConstant(Init);
return true;
}
case Expr::DeclRefExprClass: {
const Decl *D = cast<DeclRefExpr>(Init)->getDecl();
if (isa<EnumConstantDecl>(D))
return false;
InitializerElementNotConstant(Init);
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;
InitializerElementNotConstant(Init);
return true;
case Expr::UnaryOperatorClass: {
const UnaryOperator *Exp = cast<UnaryOperator>(Init);
switch (Exp->getOpcode()) {
// Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
// See C99 6.6p3.
default:
InitializerElementNotConstant(Init);
return true;
case UnaryOperator::OffsetOf:
if (Exp->getSubExpr()->getType()->isConstantSizeType())
return false;
InitializerElementNotConstant(Init);
return true;
case UnaryOperator::Extension:
case UnaryOperator::LNot:
case UnaryOperator::Plus:
case UnaryOperator::Minus:
case UnaryOperator::Not:
return CheckArithmeticConstantExpression(Exp->getSubExpr());
}
}
case Expr::SizeOfAlignOfExprClass: {
const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(Init);
// Special check for void types, which are allowed as an extension
if (Exp->getTypeOfArgument()->isVoidType())
return false;
// alignof always evaluates to a constant.
// FIXME: is sizeof(int[3.0]) a constant expression?
if (Exp->isSizeOf() && !Exp->getTypeOfArgument()->isConstantSizeType()) {
InitializerElementNotConstant(Init);
return true;
}
return false;
}
case Expr::BinaryOperatorClass: {
const BinaryOperator *Exp = cast<BinaryOperator>(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());
}
}
InitializerElementNotConstant(Init);
return true;
}
case Expr::ImplicitCastExprClass:
case Expr::CStyleCastExprClass: {
const Expr *SubExpr = cast<CastExpr>(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);
}
InitializerElementNotConstant(Init);
return true;
}
case Expr::ConditionalOperatorClass: {
const ConditionalOperator *Exp = cast<ConditionalOperator>(Init);
// If GNU extensions are disabled, we require all operands to be arithmetic
// constant expressions.
if (getLangOptions().NoExtensions) {
return CheckArithmeticConstantExpression(Exp->getCond()) ||
(Exp->getLHS() && CheckArithmeticConstantExpression(Exp->getLHS())) ||
CheckArithmeticConstantExpression(Exp->getRHS());
}
// Otherwise, we have to emulate some of the behavior of fold here.
// Basically GCC treats things like "4 ? 1 : somefunc()" as a constant
// because it can constant fold things away. To retain compatibility with
// GCC code, we see if we can fold the condition to a constant (which we
// should always be able to do in theory). If so, we only require the
// specified arm of the conditional to be a constant. This is a horrible
// hack, but is require by real world code that uses __builtin_constant_p.
APValue Val;
if (!Exp->getCond()->Evaluate(Val, Context)) {
// If Evaluate couldn't fold it, CheckArithmeticConstantExpression
// won't be able to either. Use it to emit the diagnostic though.
bool Res = CheckArithmeticConstantExpression(Exp->getCond());
assert(Res && "Evaluate couldn't evaluate this constant?");
return Res;
}
// Verify that the side following the condition is also a constant.
const Expr *TrueSide = Exp->getLHS(), *FalseSide = Exp->getRHS();
if (Val.getInt() == 0)
std::swap(TrueSide, FalseSide);
if (TrueSide && CheckArithmeticConstantExpression(TrueSide))
return true;
// Okay, the evaluated side evaluates to a constant, so we accept this.
// Check to see if the other side is obviously not a constant. If so,
// emit a warning that this is a GNU extension.
if (FalseSide && !FalseSide->isEvaluatable(Context))
Diag(Init->getExprLoc(),
diag::ext_typecheck_expression_not_constant_but_accepted)
<< FalseSide->getSourceRange();
return false;
}
}
}
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<CXXDefaultArgExpr>(Init))
return CheckForConstantInitializer(DAE->getExpr(), DclT);
if (CompoundLiteralExpr *e = dyn_cast<CompoundLiteralExpr>(Init))
return CheckForConstantInitializer(e->getInitializer(), DclT);
if (InitListExpr *Exp = dyn_cast<InitListExpr>(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<ImplicitCastExpr>(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<CastExpr>(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;
// Allow block exprs at top level.
if (Init->getType()->isBlockPointerType())
return false;
InitializerElementNotConstant(Init);
return true;
}
void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) {
Decl *RealDecl = static_cast<Decl *>(dcl);
Expr *Init = static_cast<Expr *>(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<VarDecl>(RealDecl);
if (!VDecl) {
Diag(dyn_cast<ScopedDecl>(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->getLocation(),
VDecl->getDeclName()))
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->getLocation(),
VDecl->getDeclName()))
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;
}
void Sema::ActOnUninitializedDecl(DeclTy *dcl) {
Decl *RealDecl = static_cast<Decl *>(dcl);
// If there is no declaration, there was an error parsing it. Just ignore it.
if (RealDecl == 0)
return;
if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
QualType Type = Var->getType();
// C++ [dcl.init.ref]p3:
// The initializer can be omitted for a reference only in a
// parameter declaration (8.3.5), in the declaration of a
// function return type, in the declaration of a class member
// within its class declaration (9.2), and where the extern
// specifier is explicitly used.
if (Type->isReferenceType() && Var->getStorageClass() != VarDecl::Extern) {
Diag(Var->getLocation(), diag::err_reference_var_requires_init)
<< Var->getDeclName()
<< SourceRange(Var->getLocation(), Var->getLocation());
Var->setInvalidDecl();
return;
}
// C++ [dcl.init]p9:
//
// If no initializer is specified for an object, and the object
// is of (possibly cv-qualified) non-POD class type (or array
// thereof), the object shall be default-initialized; if the
// object is of const-qualified type, the underlying class type
// shall have a user-declared default constructor.
if (getLangOptions().CPlusPlus) {
QualType InitType = Type;
if (const ArrayType *Array = Context.getAsArrayType(Type))
InitType = Array->getElementType();
if (InitType->isRecordType()) {
const CXXConstructorDecl *Constructor
= PerformInitializationByConstructor(InitType, 0, 0,
Var->getLocation(),
SourceRange(Var->getLocation(),
Var->getLocation()),
Var->getDeclName(),
IK_Default);
if (!Constructor)
Var->setInvalidDecl();
}
}
#if 0
// FIXME: Temporarily disabled because we are not properly parsing
// linkage specifications on declarations, e.g.,
//
// extern "C" const CGPoint CGPointerZero;
//
// C++ [dcl.init]p9:
//
// If no initializer is specified for an object, and the
// object is of (possibly cv-qualified) non-POD class type (or
// array thereof), the object shall be default-initialized; if
// the object is of const-qualified type, the underlying class
// type shall have a user-declared default
// constructor. Otherwise, if no initializer is specified for
// an object, the object and its subobjects, if any, have an
// indeterminate initial value; if the object or any of its
// subobjects are of const-qualified type, the program is
// ill-formed.
//
// This isn't technically an error in C, so we don't diagnose it.
//
// FIXME: Actually perform the POD/user-defined default
// constructor check.
if (getLangOptions().CPlusPlus &&
Context.getCanonicalType(Type).isConstQualified() &&
Var->getStorageClass() != VarDecl::Extern)
Diag(Var->getLocation(), diag::err_const_var_requires_init)
<< Var->getName()
<< SourceRange(Var->getLocation(), Var->getLocation());
#endif
}
}
/// 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<Decl*>(group);
if (GroupDecl == 0)
return 0;
ScopedDecl *Group = dyn_cast<ScopedDecl>(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<VarDecl>(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;
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;
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) {
// FIXME: disallow CXXScopeSpec for param declarators.
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) << II;
// 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;
// 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();
return ActOnStartOfFunctionDef(FnBodyScope,
ActOnDeclarator(GlobalScope, D, 0));
}
Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) {
Decl *decl = static_cast<Decl*>(D);
FunctionDecl *FD = cast<FunctionDecl>(decl);
// See if this is a redefinition.
const FunctionDecl *Definition;
if (FD->getBody(Definition)) {
Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName();
Diag(Definition->getLocation(), diag::note_previous_definition);
}
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<Decl *>(D);
if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(dcl)) {
FD->setBody((Stmt*)Body);
assert(FD == getCurFunctionDecl() && "Function parsing confused");
} else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
MD->setBody((Stmt*)Body);
} else
return 0;
PopDeclContext();
// Verify and clean out per-function state.
// Check goto/label use.
for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::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<CompoundStmt>((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;
else
Diag(Loc, diag::warn_implicit_function_decl) << &II;
// 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, 0, Loc));
D.SetIdentifier(&II, Loc);
// Insert this function into translation-unit scope.
DeclContext *PrevDC = CurContext;
CurContext = Context.getTranslationUnitDecl();
FunctionDecl *FD =
dyn_cast<FunctionDecl>(static_cast<Decl*>(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, const CXXScopeSpec &SS,
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, SS, Name, NameLoc, Attr);
DeclContext *DC = CurContext;
ScopedDecl *PrevDecl = 0;
if (Name && SS.isNotEmpty()) {
// We have a nested-name tag ('struct foo::bar').
// Check for invalid 'foo::'.
if (SS.isInvalid()) {
Name = 0;
goto CreateNewDecl;
}
DC = static_cast<DeclContext*>(SS.getScopeRep());
// Look-up name inside 'foo::'.
PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC));
// A tag 'foo::bar' must already exist.
if (PrevDecl == 0) {
Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange();
Name = 0;
goto CreateNewDecl;
}
} else {
// 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.
PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S));
}
if (PrevDecl) {
assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
"unexpected Decl type");
if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(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, DC, 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;
Diag(PrevDecl->getLocation(), diag::note_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;
Diag(PrevDecl->getLocation(), diag::note_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, DC, 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;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
Name = 0;
}
}
}
CreateNewDecl:
// 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, DC, 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, DC, Loc, Name);
else
New = RecordDecl::Create(Context, Kind, DC, 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);
// Set the lexical context. If the tag has a C++ scope specifier, the
// lexical context will be different from the semantic context.
New->setLexicalDeclContext(CurContext);
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, const CXXScopeSpec &SS,
IdentifierInfo *Name, SourceLocation NameLoc,
AttributeList *Attr) {
DeclContext *DC = CurContext;
ScopedDecl *PrevDecl = 0;
if (Name && SS.isNotEmpty()) {
// We have a nested-name tag ('struct foo::bar').
// Check for invalid 'foo::'.
if (SS.isInvalid()) {
Name = 0;
goto CreateNewDecl;
}
DC = static_cast<DeclContext*>(SS.getScopeRep());
// Look-up name inside 'foo::'.
PrevDecl = dyn_cast_or_null<TagDecl>(LookupDecl(Name, Decl::IDNS_Tag,S,DC));
// A tag 'foo::bar' must already exist.
if (PrevDecl == 0) {
Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange();
Name = 0;
goto CreateNewDecl;
}
} else {
// 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.
PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S));
}
if (PrevDecl) {
assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
"unexpected Decl type");
if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(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, DC, 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;
Diag(PrevDecl->getLocation(), diag::note_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<RecordDecl>(PrevTagDecl)->getDefinition(Context)) {
Diag(NameLoc, diag::err_redefinition) << Name;
Diag(DefRecord->getLocation(), diag::note_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, DC, 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;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
Name = 0;
}
}
}
CreateNewDecl:
// 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, DC, Loc, Name,
dyn_cast_or_null<CXXRecordDecl>(PrevDecl));
else
New = RecordDecl::Create(Context, Kind, DC, Loc, Name,
dyn_cast_or_null<RecordDecl>(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);
}
// Handle #pragma pack: if the #pragma pack stack has non-default
// alignment, make up a packed attribute for this decl. These
// attributes are checked when the ASTContext lays out the
// structure.
//
// It is important for implementing the correct semantics that this
// happen here (in act on tag decl). The #pragma pack stack is
// maintained as a result of parser callbacks which can occur at
// many points during the parsing of a struct declaration (because
// the #pragma tokens are effectively skipped over during the
// parsing of the struct).
if (unsigned Alignment = PackContext.getAlignment())
New->addAttr(new PackedAttr(Alignment * 8));
if (Attr)
ProcessDeclAttributeList(New, Attr);
// Set the lexical context. If the tag has a C++ scope specifier, the
// lexical context will be different from the semantic context.
New->setLexicalDeclContext(CurContext);
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<Sema::DeclTy*> &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<DeclTy*> &Decls) {
// Check that ClassName is a valid class
ObjCInterfaceDecl *Class = getObjCInterfaceDecl(ClassName);
if (!Class) {
Diag(DeclStart, diag::err_undef_interface) << ClassName;
return;
}
// Collect the instance variables
CollectIvars(Class, Context, Decls);
}
/// TryToFixInvalidVariablyModifiedType - Helper method to turn variable array
/// types into constant array types in certain situations which would otherwise
/// be errors (for GCC compatibility).
static QualType TryToFixInvalidVariablyModifiedType(QualType T,
ASTContext &Context) {
// 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];}
const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
if (!VLATy) return QualType();
APValue Result;
if (!VLATy->getSizeExpr() ||
!VLATy->getSizeExpr()->Evaluate(Result, Context))
return QualType();
assert(Result.isInt() && "Size expressions must be integers!");
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 = TryToFixInvalidVariablyModifiedType(T, Context);
if (!FixedTy.isNull()) {
Diag(Loc, diag::warn_illegal_constant_array_size);
T = FixedTy;
} else {
Diag(Loc, diag::err_typecheck_field_variable_size);
T = Context.IntTy;
InvalidDecl = true;
}
}
// FIXME: Chain fielddecls together.
FieldDecl *NewFD;
if (getLangOptions().CPlusPlus) {
// FIXME: Replace CXXFieldDecls with FieldDecls for simple structs.
NewFD = CXXFieldDecl::Create(Context, cast<CXXRecordDecl>(CurContext),
Loc, II, T,
D.getDeclSpec().getStorageClassSpec() ==
DeclSpec::SCS_mutable, 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) {
default: assert(0 && "Unknown visitibility kind");
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;
}
}
/// 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) << SourceRange(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,
AttributeList *Attr) {
Decl *EnclosingDecl = static_cast<Decl*>(RecDecl);
assert(EnclosingDecl && "missing record or interface decl");
RecordDecl *Record = dyn_cast<RecordDecl>(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->getDeclName();
Diag(RecLoc, diag::note_previous_definition);
Record->setInvalidDecl();
return;
}
// Verify that all the fields are okay.
unsigned NumNamedMembers = 0;
llvm::SmallVector<FieldDecl*, 32> RecFields;
llvm::SmallSet<const IdentifierInfo*, 32> FieldIDs;
for (unsigned i = 0; i != NumFields; ++i) {
FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(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->getDeclName();
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->getDeclName();
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->getDeclName();
FD->setInvalidDecl();
EnclosingDecl->setInvalidDecl();
continue;
}
if (NumNamedMembers < 1) { //... must have more than named member ...
Diag(FD->getLocation(), diag::err_flexible_array_empty_struct)
<< FD->getDeclName();
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->getDeclName();
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->getDeclName();
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->getDeclName();
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;
// Find the previous decl.
SourceLocation PrevLoc;
for (unsigned i = 0; ; ++i) {
assert(i != RecFields.size() && "Didn't find previous def!");
if (RecFields[i]->getIdentifier() == II) {
PrevLoc = RecFields[i]->getLocation();
break;
}
}
Diag(PrevLoc, diag::note_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<CXXRecordDecl>(Record))
Consumer.HandleTagDeclDefinition(Record);
} else {
ObjCIvarDecl **ClsFields = reinterpret_cast<ObjCIvarDecl**>(&RecFields[0]);
if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl))
ID->addInstanceVariablesToClass(ClsFields, RecFields.size(), RBrac);
else if (ObjCImplementationDecl *IMPDecl =
dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
IMPDecl->ObjCAddInstanceVariablesToClassImpl(ClsFields, RecFields.size());
CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
}
}
if (Attr)
ProcessDeclAttributeList(Record, Attr);
}
Sema::DeclTy *Sema::ActOnEnumConstant(Scope *S, DeclTy *theEnumDecl,
DeclTy *lastEnumConst,
SourceLocation IdLoc, IdentifierInfo *Id,
SourceLocation EqualLoc, ExprTy *val) {
EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(theEnumDecl));
EnumConstantDecl *LastEnumConst =
cast_or_null<EnumConstantDecl>(static_cast<Decl*>(lastEnumConst));
Expr *Val = static_cast<Expr*>(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<TagDecl>(PrevDecl)) &&
"Received TagDecl when not in C++!");
if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) {
if (isa<EnumConstantDecl>(PrevDecl))
Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
else
Diag(IdLoc, diag::err_redefinition) << Id;
Diag(PrevDecl->getLocation(), diag::note_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;
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<uint32_t>(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<EnumDecl>(static_cast<Decl*>(EnumDeclX));
if (Enum && Enum->isDefinition()) {
// Diagnose code like:
// enum e0 {
// E0 = sizeof(enum e0 { E1 })
// };
Diag(Enum->getLocation(), diag::err_nested_redefinition)
<< Enum->getDeclName();
Diag(EnumLoc, diag::note_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<EnumConstantDecl>(static_cast<Decl*>(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<EnumConstantDecl>(static_cast<Decl*>(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(),
/*isLvalue=*/false));
ECD->setType(NewTy);
}
Enum->defineElements(EltList, BestType);
Consumer.HandleTagDeclDefinition(Enum);
}
Sema::DeclTy *Sema::ActOnFileScopeAsmDecl(SourceLocation Loc,
ExprTy *expr) {
StringLiteral *AsmString = cast<StringLiteral>((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<Decl *>(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);
}
void Sema::ActOnPragmaPack(PragmaPackKind Kind, IdentifierInfo *Name,
ExprTy *alignment, SourceLocation PragmaLoc,
SourceLocation LParenLoc, SourceLocation RParenLoc) {
Expr *Alignment = static_cast<Expr *>(alignment);
// If specified then alignment must be a "small" power of two.
unsigned AlignmentVal = 0;
if (Alignment) {
llvm::APSInt Val;
if (!Alignment->isIntegerConstantExpr(Val, Context) ||
!Val.isPowerOf2() ||
Val.getZExtValue() > 16) {
Diag(PragmaLoc, diag::warn_pragma_pack_invalid_alignment);
delete Alignment;
return; // Ignore
}
AlignmentVal = (unsigned) Val.getZExtValue();
}
switch (Kind) {
case Action::PPK_Default: // pack([n])
PackContext.setAlignment(AlignmentVal);
break;
case Action::PPK_Show: // pack(show)
// Show the current alignment, making sure to show the right value
// for the default.
AlignmentVal = PackContext.getAlignment();
// FIXME: This should come from the target.
if (AlignmentVal == 0)
AlignmentVal = 8;
Diag(PragmaLoc, diag::warn_pragma_pack_show) << AlignmentVal;
break;
case Action::PPK_Push: // pack(push [, id] [, [n])
PackContext.push(Name);
// Set the new alignment if specified.
if (Alignment)
PackContext.setAlignment(AlignmentVal);
break;
case Action::PPK_Pop: // pack(pop [, id] [, n])
// MSDN, C/C++ Preprocessor Reference > Pragma Directives > pack:
// "#pragma pack(pop, identifier, n) is undefined"
if (Alignment && Name)
Diag(PragmaLoc, diag::warn_pragma_pack_pop_identifer_and_alignment);
// Do the pop.
if (!PackContext.pop(Name)) {
// If a name was specified then failure indicates the name
// wasn't found. Otherwise failure indicates the stack was
// empty.
Diag(PragmaLoc, diag::warn_pragma_pack_pop_failed)
<< (Name ? "no record matching name" : "stack empty");
// FIXME: Warn about popping named records as MSVC does.
} else {
// Pop succeeded, set the new alignment if specified.
if (Alignment)
PackContext.setAlignment(AlignmentVal);
}
break;
default:
assert(0 && "Invalid #pragma pack kind.");
}
}
bool PragmaPackStack::pop(IdentifierInfo *Name) {
if (Stack.empty())
return false;
// If name is empty just pop top.
if (!Name) {
Alignment = Stack.back().first;
Stack.pop_back();
return true;
}
// Otherwise, find the named record.
for (unsigned i = Stack.size(); i != 0; ) {
--i;
if (Stack[i].second == Name) {
// Found it, pop up to and including this record.
Alignment = Stack[i].first;
Stack.erase(Stack.begin() + i, Stack.end());
return true;
}
}
return false;
}
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