clang-1/Sema/SemaType.cpp

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C++

//===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements type-related semantic analysis.
//
//===----------------------------------------------------------------------===//
#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Basic/LangOptions.h"
using namespace clang;
/// ConvertDeclSpecToType - Convert the specified declspec to the appropriate
/// type object. This returns null on error.
QualType Sema::ConvertDeclSpecToType(DeclSpec &DS) {
// FIXME: Should move the logic from DeclSpec::Finish to here for validity
// checking.
QualType Result;
switch (DS.getTypeSpecType()) {
default: return QualType(); // FIXME: Handle unimp cases!
case DeclSpec::TST_void: return Context.VoidTy;
case DeclSpec::TST_char:
if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
Result = Context.CharTy;
else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
Result = Context.SignedCharTy;
else {
assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
"Unknown TSS value");
Result = Context.UnsignedCharTy;
}
break;
case DeclSpec::TST_unspecified: // Unspecific typespec defaults to int.
case DeclSpec::TST_int: {
if (DS.getTypeSpecSign() != DeclSpec::TSS_unsigned) {
switch (DS.getTypeSpecWidth()) {
case DeclSpec::TSW_unspecified: Result = Context.IntTy; break;
case DeclSpec::TSW_short: Result = Context.ShortTy; break;
case DeclSpec::TSW_long: Result = Context.LongTy; break;
case DeclSpec::TSW_longlong: Result = Context.LongLongTy; break;
}
} else {
switch (DS.getTypeSpecWidth()) {
case DeclSpec::TSW_unspecified: Result = Context.UnsignedIntTy; break;
case DeclSpec::TSW_short: Result = Context.UnsignedShortTy; break;
case DeclSpec::TSW_long: Result = Context.UnsignedLongTy; break;
case DeclSpec::TSW_longlong: Result =Context.UnsignedLongLongTy; break;
}
}
break;
}
case DeclSpec::TST_float: Result = Context.FloatTy; break;
case DeclSpec::TST_double:
if (DS.getTypeSpecWidth() == DeclSpec::TSW_long)
Result = Context.LongDoubleTy;
else
Result = Context.DoubleTy;
break;
case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
case DeclSpec::TST_decimal32: // _Decimal32
case DeclSpec::TST_decimal64: // _Decimal64
case DeclSpec::TST_decimal128: // _Decimal128
assert(0 && "FIXME: GNU decimal extensions not supported yet!");
case DeclSpec::TST_enum:
case DeclSpec::TST_union:
case DeclSpec::TST_struct: {
Decl *D = static_cast<Decl *>(DS.getTypeRep());
assert(D && "Didn't get a decl for a enum/union/struct?");
assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
DS.getTypeSpecSign() == 0 &&
"Can't handle qualifiers on typedef names yet!");
// TypeQuals handled by caller.
Result = Context.getTagDeclType(cast<TagDecl>(D));
break;
}
case DeclSpec::TST_typedef: {
Decl *D = static_cast<Decl *>(DS.getTypeRep());
assert(D && "Didn't get a decl for a typedef?");
assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
DS.getTypeSpecSign() == 0 &&
"Can't handle qualifiers on typedef names yet!");
// FIXME: Adding a TST_objcInterface clause doesn't seem ideal, so
// we have this "hack" for now...
if (ObjCInterfaceDecl *ObjCIntDecl = dyn_cast<ObjCInterfaceDecl>(D)) {
if (DS.getProtocolQualifiers() == 0) {
Result = Context.getObjCInterfaceType(ObjCIntDecl);
break;
}
Action::DeclTy **PPDecl = &(*DS.getProtocolQualifiers())[0];
Result = Context.getObjCQualifiedInterfaceType(ObjCIntDecl,
reinterpret_cast<ObjCProtocolDecl**>(PPDecl),
DS.getNumProtocolQualifiers());
break;
}
else if (TypedefDecl *typeDecl = dyn_cast<TypedefDecl>(D)) {
if (Context.getObjCIdType() == Context.getTypedefType(typeDecl)
&& DS.getProtocolQualifiers()) {
// id<protocol-list>
Action::DeclTy **PPDecl = &(*DS.getProtocolQualifiers())[0];
Result = Context.getObjCQualifiedIdType(typeDecl->getUnderlyingType(),
reinterpret_cast<ObjCProtocolDecl**>(PPDecl),
DS.getNumProtocolQualifiers());
break;
}
}
// TypeQuals handled by caller.
Result = Context.getTypedefType(cast<TypedefDecl>(D));
break;
}
case DeclSpec::TST_typeofType:
Result = QualType::getFromOpaquePtr(DS.getTypeRep());
assert(!Result.isNull() && "Didn't get a type for typeof?");
// TypeQuals handled by caller.
Result = Context.getTypeOfType(Result);
break;
case DeclSpec::TST_typeofExpr: {
Expr *E = static_cast<Expr *>(DS.getTypeRep());
assert(E && "Didn't get an expression for typeof?");
// TypeQuals handled by caller.
Result = Context.getTypeOfExpr(E);
break;
}
}
// Handle complex types.
if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex)
Result = Context.getComplexType(Result);
assert(DS.getTypeSpecComplex() != DeclSpec::TSC_imaginary &&
"FIXME: imaginary types not supported yet!");
// See if there are any attributes on the declspec that apply to the type (as
// opposed to the decl).
if (AttributeList *AL = DS.getAttributes())
DS.SetAttributes(ProcessTypeAttributes(Result, AL));
return Result;
}
/// GetTypeForDeclarator - Convert the type for the specified declarator to Type
/// instances.
QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
// long long is a C99 feature.
if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x &&
D.getDeclSpec().getTypeSpecWidth() == DeclSpec::TSW_longlong)
Diag(D.getDeclSpec().getTypeSpecWidthLoc(), diag::ext_longlong);
QualType T = ConvertDeclSpecToType(D.getDeclSpec());
// Apply const/volatile/restrict qualifiers to T.
T = T.getQualifiedType(D.getDeclSpec().getTypeQualifiers());
// Walk the DeclTypeInfo, building the recursive type as we go. DeclTypeInfos
// are ordered from the identifier out, which is opposite of what we want :).
for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
DeclaratorChunk &DeclType = D.getTypeObject(e-i-1);
switch (DeclType.Kind) {
default: assert(0 && "Unknown decltype!");
case DeclaratorChunk::Pointer:
if (T->isReferenceType()) {
// C++ 8.3.2p4: There shall be no ... pointers to references ...
Diag(D.getIdentifierLoc(), diag::err_illegal_decl_pointer_to_reference,
D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
D.setInvalidType(true);
T = Context.IntTy;
}
// Apply the pointer typequals to the pointer object.
T = Context.getPointerType(T).getQualifiedType(DeclType.Ptr.TypeQuals);
// See if there are any attributes on the pointer that apply to it.
if (AttributeList *AL = DeclType.Ptr.AttrList)
DeclType.Ptr.AttrList = ProcessTypeAttributes(T, AL);
break;
case DeclaratorChunk::Reference:
if (const ReferenceType *RT = T->getAsReferenceType()) {
// C++ 8.3.2p4: There shall be no references to references.
Diag(D.getIdentifierLoc(),
diag::err_illegal_decl_reference_to_reference,
D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
D.setInvalidType(true);
T = RT->getReferenceeType();
}
T = Context.getReferenceType(T);
// FIXME: Handle Ref.Restrict!
// See if there are any attributes on the pointer that apply to it.
if (AttributeList *AL = DeclType.Ref.AttrList)
DeclType.Ref.AttrList = ProcessTypeAttributes(T, AL);
break;
case DeclaratorChunk::Array: {
const DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
ArrayType::ArraySizeModifier ASM;
if (ATI.isStar)
ASM = ArrayType::Star;
else if (ATI.hasStatic)
ASM = ArrayType::Static;
else
ASM = ArrayType::Normal;
// C99 6.7.5.2p1: If the element type is an incomplete or function type,
// reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
if (T->isIncompleteType()) {
Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_incomplete_type,
T.getAsString());
T = Context.IntTy;
D.setInvalidType(true);
} else if (T->isFunctionType()) {
Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_of_functions,
D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
T = Context.getPointerType(T);
D.setInvalidType(true);
} else if (const ReferenceType *RT = T->getAsReferenceType()) {
// C++ 8.3.2p4: There shall be no ... arrays of references ...
Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_of_references,
D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
T = RT->getReferenceeType();
D.setInvalidType(true);
} else if (const RecordType *EltTy = T->getAsRecordType()) {
// If the element type is a struct or union that contains a variadic
// array, reject it: C99 6.7.2.1p2.
if (EltTy->getDecl()->hasFlexibleArrayMember()) {
Diag(DeclType.Loc, diag::err_flexible_array_in_array,
T.getAsString());
T = Context.IntTy;
D.setInvalidType(true);
}
}
// C99 6.7.5.2p1: The size expression shall have integer type.
if (ArraySize && !ArraySize->getType()->isIntegerType()) {
Diag(ArraySize->getLocStart(), diag::err_array_size_non_int,
ArraySize->getType().getAsString(), ArraySize->getSourceRange());
D.setInvalidType(true);
}
llvm::APSInt ConstVal(32);
// If no expression was provided, we consider it a VLA.
if (!ArraySize) {
T = Context.getIncompleteArrayType(T, ASM, ATI.TypeQuals);
} else if (!ArraySize->isIntegerConstantExpr(ConstVal, Context)) {
T = Context.getVariableArrayType(T, ArraySize, ASM, ATI.TypeQuals);
} else {
// C99 6.7.5.2p1: If the expression is a constant expression, it shall
// have a value greater than zero.
if (ConstVal.isSigned()) {
if (ConstVal.isNegative()) {
Diag(ArraySize->getLocStart(),
diag::err_typecheck_negative_array_size,
ArraySize->getSourceRange());
D.setInvalidType(true);
} else if (ConstVal == 0) {
// GCC accepts zero sized static arrays.
Diag(ArraySize->getLocStart(), diag::ext_typecheck_zero_array_size,
ArraySize->getSourceRange());
}
}
T = Context.getConstantArrayType(T, ConstVal, ASM, ATI.TypeQuals);
}
// If this is not C99, extwarn about VLA's and C99 array size modifiers.
if (!getLangOptions().C99 &&
(ASM != ArrayType::Normal ||
(ArraySize && !ArraySize->isIntegerConstantExpr(Context))))
Diag(D.getIdentifierLoc(), diag::ext_vla);
break;
}
case DeclaratorChunk::Function:
// If the function declarator has a prototype (i.e. it is not () and
// does not have a K&R-style identifier list), then the arguments are part
// of the type, otherwise the argument list is ().
const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
// C99 6.7.5.3p1: The return type may not be a function or array type.
if (T->isArrayType() || T->isFunctionType()) {
Diag(DeclType.Loc, diag::err_func_returning_array_function,
T.getAsString());
T = Context.IntTy;
D.setInvalidType(true);
}
if (!FTI.hasPrototype) {
// Simple void foo(), where the incoming T is the result type.
T = Context.getFunctionTypeNoProto(T);
// C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function definition.
if (FTI.NumArgs != 0)
Diag(FTI.ArgInfo[0].IdentLoc, diag::err_ident_list_in_fn_declaration);
} else {
// Otherwise, we have a function with an argument list that is
// potentially variadic.
llvm::SmallVector<QualType, 16> ArgTys;
for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
QualType ArgTy = QualType::getFromOpaquePtr(FTI.ArgInfo[i].TypeInfo);
assert(!ArgTy.isNull() && "Couldn't parse type?");
//
// Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
// This matches the conversion that is done in
// Sema::ActOnParamDeclarator(). Without this conversion, the
// argument type in the function prototype *will not* match the
// type in ParmVarDecl (which makes the code generator unhappy).
//
// FIXME: We still apparently need the conversion in
// Sema::ParseParamDeclarator(). This doesn't make any sense, since
// it should be driving off the type being created here.
//
// FIXME: If a source translation tool needs to see the original type,
// then we need to consider storing both types somewhere...
//
if (const ArrayType *AT = ArgTy->getAsArrayType()) {
// int x[restrict 4] -> int *restrict
ArgTy = Context.getPointerType(AT->getElementType());
ArgTy = ArgTy.getQualifiedType(AT->getIndexTypeQualifier());
} else if (ArgTy->isFunctionType())
ArgTy = Context.getPointerType(ArgTy);
// Look for 'void'. void is allowed only as a single argument to a
// function with no other parameters (C99 6.7.5.3p10). We record
// int(void) as a FunctionTypeProto with an empty argument list.
else if (ArgTy->isVoidType()) {
// If this is something like 'float(int, void)', reject it. 'void'
// is an incomplete type (C99 6.2.5p19) and function decls cannot
// have arguments of incomplete type.
if (FTI.NumArgs != 1 || FTI.isVariadic) {
Diag(DeclType.Loc, diag::err_void_only_param);
ArgTy = Context.IntTy;
FTI.ArgInfo[i].TypeInfo = ArgTy.getAsOpaquePtr();
} else if (FTI.ArgInfo[i].Ident) {
// Reject, but continue to parse 'int(void abc)'.
Diag(FTI.ArgInfo[i].IdentLoc,
diag::err_param_with_void_type);
ArgTy = Context.IntTy;
FTI.ArgInfo[i].TypeInfo = ArgTy.getAsOpaquePtr();
} else {
// Reject, but continue to parse 'float(const void)'.
if (ArgTy.getCVRQualifiers())
Diag(DeclType.Loc, diag::err_void_param_qualified);
// Do not add 'void' to the ArgTys list.
break;
}
}
ArgTys.push_back(ArgTy);
}
T = Context.getFunctionType(T, &ArgTys[0], ArgTys.size(),
FTI.isVariadic);
}
break;
}
}
return T;
}
/// ObjCGetTypeForMethodDefinition - Builds the type for a method definition
/// declarator
QualType Sema::ObjCGetTypeForMethodDefinition(DeclTy *D) {
ObjCMethodDecl *MDecl = dyn_cast<ObjCMethodDecl>(static_cast<Decl *>(D));
QualType T = MDecl->getResultType();
llvm::SmallVector<QualType, 16> ArgTys;
// Add the first two invisible argument types for self and _cmd.
if (MDecl->isInstance()) {
QualType selfTy = Context.getObjCInterfaceType(MDecl->getClassInterface());
selfTy = Context.getPointerType(selfTy);
ArgTys.push_back(selfTy);
}
else
ArgTys.push_back(Context.getObjCIdType());
ArgTys.push_back(Context.getObjCSelType());
for (int i = 0; i < MDecl->getNumParams(); i++) {
ParmVarDecl *PDecl = MDecl->getParamDecl(i);
QualType ArgTy = PDecl->getType();
assert(!ArgTy.isNull() && "Couldn't parse type?");
// Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
// This matches the conversion that is done in
// Sema::ParseParamDeclarator().
if (const ArrayType *AT = ArgTy->getAsArrayType())
ArgTy = Context.getPointerType(AT->getElementType());
else if (ArgTy->isFunctionType())
ArgTy = Context.getPointerType(ArgTy);
ArgTys.push_back(ArgTy);
}
T = Context.getFunctionType(T, &ArgTys[0], ArgTys.size(),
MDecl->isVariadic());
return T;
}
Sema::TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
// C99 6.7.6: Type names have no identifier. This is already validated by
// the parser.
assert(D.getIdentifier() == 0 && "Type name should have no identifier!");
QualType T = GetTypeForDeclarator(D, S);
assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
// 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.
return T.getAsOpaquePtr();
}
// Called from Parser::ParseParenDeclarator().
Sema::TypeResult Sema::ActOnParamDeclaratorType(Scope *S, Declarator &D) {
// Note: parameters have identifiers, but we don't care about them here, we
// just want the type converted.
QualType T = GetTypeForDeclarator(D, S);
assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
// 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.
return T.getAsOpaquePtr();
}
AttributeList *Sema::ProcessTypeAttributes(QualType &Result, AttributeList *AL){
// Scan through and apply attributes to this type where it makes sense. Some
// attributes (such as __address_space__, __vector_size__, etc) apply to the
// type, but others can be present in the type specifiers even though they
// apply to the decl. Here we apply and delete attributes that apply to the
// type and leave the others alone.
llvm::SmallVector<AttributeList *, 8> LeftOverAttrs;
while (AL) {
// Unlink this attribute from the chain, so we can process it independently.
AttributeList *ThisAttr = AL;
AL = AL->getNext();
ThisAttr->setNext(0);
// If this is an attribute we can handle, do so now, otherwise, add it to
// the LeftOverAttrs list for rechaining.
switch (ThisAttr->getKind()) {
default: break;
case AttributeList::AT_address_space:
Result = HandleAddressSpaceTypeAttribute(Result, ThisAttr);
delete ThisAttr; // Consume the attribute.
continue;
}
LeftOverAttrs.push_back(ThisAttr);
}
// Rechain any attributes that haven't been deleted to the DeclSpec.
AttributeList *List = 0;
for (unsigned i = 0, e = LeftOverAttrs.size(); i != e; ++i) {
LeftOverAttrs[i]->setNext(List);
List = LeftOverAttrs[i];
}
return List;
}
/// HandleAddressSpaceTypeAttribute - Process an address_space attribute on the
/// specified type.
QualType Sema::HandleAddressSpaceTypeAttribute(QualType Type,
AttributeList *Attr) {
// If this type is already address space qualified, reject it.
// Clause 6.7.3 - Type qualifiers: "No type shall be qualified by qualifiers
// for two or more different address spaces."
if (Type.getAddressSpace()) {
Diag(Attr->getLoc(), diag::err_attribute_address_multiple_qualifiers);
return Type;
}
// Check the attribute arguments.
if (Attr->getNumArgs() != 1) {
Diag(Attr->getLoc(), diag::err_attribute_wrong_number_arguments,
std::string("1"));
return Type;
}
Expr *ASArgExpr = static_cast<Expr *>(Attr->getArg(0));
llvm::APSInt addrSpace(32);
if (!ASArgExpr->isIntegerConstantExpr(addrSpace, Context)) {
Diag(Attr->getLoc(), diag::err_attribute_address_space_not_int,
ASArgExpr->getSourceRange());
return Type;
}
unsigned ASIdx = static_cast<unsigned>(addrSpace.getZExtValue());
return Context.getASQualType(Type, ASIdx);
}