[cfe-commits] r70497 - in /cfe/trunk: lib/AST/ASTContext.cpp lib/AST/ExprConstant.cpp test/Sema/attr-aligned.c
Douglas Gregor
dgregor at apple.com
Thu Apr 30 10:32:17 PDT 2009
Author: dgregor
Date: Thu Apr 30 12:32:17 2009
New Revision: 70497
URL: http://llvm.org/viewvc/llvm-project?rev=70497&view=rev
Log:
Properly compute the alignment of typedefs that make use of the
"aligned" attribute. Previously, we were skipping over these
attributes when we jumped directly to the canonical type. Now,
ASTContext::getTypeInfo walks through typedefs and other
"non-canonical" types manually, looking for "aligned" attributes on
typedefs.
As part of this change, I moved the GNU-specific logic (such as
determining the alignment of void or of a function pointer) out of the
expression evaluator and into ASTContext::getTypeInfo.
Modified:
cfe/trunk/lib/AST/ASTContext.cpp
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/test/Sema/attr-aligned.c
Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=70497&r1=70496&r2=70497&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Thu Apr 30 12:32:17 2009
@@ -334,24 +334,30 @@
/// does not work on incomplete types.
std::pair<uint64_t, unsigned>
ASTContext::getTypeInfo(const Type *T) {
- T = getCanonicalType(T);
uint64_t Width=0;
unsigned Align=8;
switch (T->getTypeClass()) {
#define TYPE(Class, Base)
#define ABSTRACT_TYPE(Class, Base)
-#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
+#define NON_CANONICAL_TYPE(Class, Base)
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
#include "clang/AST/TypeNodes.def"
- assert(false && "Should not see non-canonical or dependent types");
+ assert(false && "Should not see dependent types");
break;
case Type::FunctionNoProto:
case Type::FunctionProto:
+ // GCC extension: alignof(function) = 32 bits
+ Width = 0;
+ Align = 32;
+ break;
+
case Type::IncompleteArray:
- assert(0 && "Incomplete types have no size!");
case Type::VariableArray:
- assert(0 && "VLAs not implemented yet!");
+ Width = 0;
+ Align = getTypeAlign(cast<ArrayType>(T)->getElementType());
+ break;
+
case Type::ConstantArray: {
const ConstantArrayType *CAT = cast<ConstantArrayType>(T);
@@ -377,7 +383,11 @@
switch (cast<BuiltinType>(T)->getKind()) {
default: assert(0 && "Unknown builtin type!");
case BuiltinType::Void:
- assert(0 && "Incomplete types have no size!");
+ // GCC extension: alignof(void) = 8 bits.
+ Width = 0;
+ Align = 8;
+ break;
+
case BuiltinType::Bool:
Width = Target.getBoolWidth();
Align = Target.getBoolAlign();
@@ -517,10 +527,34 @@
break;
}
- case Type::TemplateSpecialization:
- assert(false && "Dependent types have no size");
+ case Type::Typedef: {
+ const TypedefDecl *Typedef = cast<TypedefType>(T)->getDecl();
+ if (const AlignedAttr *Aligned = Typedef->getAttr<AlignedAttr>()) {
+ Align = Aligned->getAlignment();
+ Width = getTypeSize(Typedef->getUnderlyingType().getTypePtr());
+ } else
+ return getTypeInfo(Typedef->getUnderlyingType().getTypePtr());
break;
}
+
+ case Type::TypeOfExpr:
+ return getTypeInfo(cast<TypeOfExprType>(T)->getUnderlyingExpr()->getType()
+ .getTypePtr());
+
+ case Type::TypeOf:
+ return getTypeInfo(cast<TypeOfType>(T)->getUnderlyingType().getTypePtr());
+
+ case Type::QualifiedName:
+ return getTypeInfo(cast<QualifiedNameType>(T)->getNamedType().getTypePtr());
+
+ case Type::TemplateSpecialization:
+ assert(getCanonicalType(T) != T &&
+ "Cannot request the size of a dependent type");
+ // FIXME: this is likely to be wrong once we support template
+ // aliases, since a template alias could refer to a typedef that
+ // has an __aligned__ attribute on it.
+ return getTypeInfo(getCanonicalType(T));
+ }
assert(Align && (Align & (Align-1)) == 0 && "Alignment must be power of 2");
return std::make_pair(Width, Align);
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=70497&r1=70496&r2=70497&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Apr 30 12:32:17 2009
@@ -1021,32 +1021,11 @@
}
unsigned IntExprEvaluator::GetAlignOfType(QualType T) {
- const Type *Ty = Info.Ctx.getCanonicalType(T).getTypePtr();
-
- // __alignof__(void) = 1 as a gcc extension.
- if (Ty->isVoidType())
- return 1;
-
- // GCC extension: alignof(function) = 4.
- // FIXME: AlignOf shouldn't be unconditionally 4! It should listen to the
- // attribute(align) directive.
- if (Ty->isFunctionType())
- return 4;
-
- if (const ExtQualType *EXTQT = dyn_cast<ExtQualType>(Ty))
- return GetAlignOfType(QualType(EXTQT->getBaseType(), 0));
-
- // alignof VLA/incomplete array.
- if (const ArrayType *VAT = dyn_cast<ArrayType>(Ty))
- return GetAlignOfType(VAT->getElementType());
-
- // sizeof (objc class)?
- if (isa<ObjCInterfaceType>(Ty))
- return 1; // FIXME: This probably isn't right.
-
// Get information about the alignment.
unsigned CharSize = Info.Ctx.Target.getCharWidth();
- return Info.Ctx.getPreferredTypeAlign(Ty) / CharSize;
+
+ // FIXME: Why do we ask for the preferred alignment?
+ return Info.Ctx.getPreferredTypeAlign(T.getTypePtr()) / CharSize;
}
unsigned IntExprEvaluator::GetAlignOfExpr(const Expr *E) {
Modified: cfe/trunk/test/Sema/attr-aligned.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-aligned.c?rev=70497&r1=70496&r2=70497&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-aligned.c (original)
+++ cfe/trunk/test/Sema/attr-aligned.c Thu Apr 30 12:32:17 2009
@@ -5,3 +5,17 @@
// PR3254
short g0[3] __attribute__((aligned));
short g0_chk[__alignof__(g0) == 16 ? 1 : -1];
+
+// <rdar://problem/6840045>
+typedef char ueber_aligned_char __attribute__((aligned(8)));
+
+struct struct_with_ueber_char {
+ ueber_aligned_char c;
+};
+
+char c = 0;
+
+char a0[__alignof__(ueber_aligned_char) == 8? 1 : -1] = { 0 };
+char a1[__alignof__(struct struct_with_ueber_char) == 8? 1 : -1] = { 0 };
+char a2[__alignof__(c) == 1? : -1] = { 0 };
+char a3[sizeof(c) == 1? : -1] = { 0 };
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