mirrors/llvm-project
0
0
Fork 0
mirror of https://github.com/llvm/llvm-project.git synced 2025-04-28 03:36:06 +00:00
Code Issues Projects Releases Wiki Activity

Add ability to layout the vtable pointer in trivial cases. I noticed

Browse Source 
that we would silently do bad things with virtual bases in the layout
code, so, we just turn them off.  When people do better things with
them, we can turn them back on.

llvm-svn: 77556
This commit is contained in:
Mike Stump 2009-07-30 00:22:38 +00:00
parent 13ddd8514f
commit 3dc7eb9440
4 changed files with 29 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
clang/lib/AST/RecordLayoutBuilder.cpp
View File

@ -24,11 +24,19 @@ ASTRecordLayoutBuilder::ASTRecordLayoutBuilder(ASTContext &Ctx)
: Ctx(Ctx), Size(0), Alignment(8), StructPacking(0), NextOffset(0),
IsUnion(false), NonVirtualSize(0), NonVirtualAlignment(8) {}
void ASTRecordLayoutBuilder::LayoutVtable(const CXXRecordDecl *RD) {
if (RD->isPolymorphic())
{
assert (RD->getNumBases() == 0 && "no polymorphic inheritance yet");
int AS = 0;
UpdateAlignment(Ctx.Target.getPointerAlign(AS));
Size += Ctx.Target.getPointerWidth(AS);
NextOffset = Size;
}
}
void
ASTRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) {
assert(!RD->isPolymorphic() &&
"FIXME: We don't support polymorphic classes yet!");
for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
e = RD->bases_end(); i != e; ++i) {
if (!i->isVirtual()) {
@ -74,14 +82,20 @@ void ASTRecordLayoutBuilder::Layout(const RecordDecl *D) {
UpdateAlignment(AA->getAlignment());
// If this is a C++ class, lay out the nonvirtual bases.
if (Ctx.getLangOptions().CPlusPlus)
LayoutNonVirtualBases(cast<CXXRecordDecl>(D));
if (Ctx.getLangOptions().CPlusPlus) {
const CXXRecordDecl *RD = cast<CXXRecordDecl>(D);
LayoutVtable(RD);
LayoutNonVirtualBases(RD);
assert (RD->getNumVBases() == 0
&& "FIXME: We don't support virtual bases yet!");
}
LayoutFields(D);
NonVirtualSize = Size;
NonVirtualAlignment = Alignment;
// Finally, round the size of the total struct up to the alignment of the
// struct itself.
FinishLayout();

1
clang/lib/AST/RecordLayoutBuilder.h
View File

@ -48,6 +48,7 @@ class ASTRecordLayoutBuilder {
void LayoutFields(const RecordDecl *D);
void LayoutField(const FieldDecl *D);
void LayoutVtable(const CXXRecordDecl *RD);
void LayoutNonVirtualBases(const CXXRecordDecl *RD);
void LayoutNonVirtualBase(const CXXRecordDecl *RD);

2
clang/lib/CodeGen/CodeGenTypes.cpp
View File

@ -381,8 +381,6 @@ const llvm::Type *CodeGenTypes::ConvertTagDeclType(const TagDecl *TD) {
// FIXME. This may have to move to a better place.
if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
assert(!RD->isPolymorphic() &&
"FIXME: We don't support polymorphic classes yet!");
for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
e = RD->bases_end(); i != e; ++i) {
if (!i->isVirtual()) {

8
clang/test/CodeGenCXX/virt.cpp Normal file
View File

@ -0,0 +1,8 @@
// RUN: clang-cc %s -emit-llvm -o - -std=c++0x
class A {
public:
virtual void foo();
};
static_assert (sizeof (A) == (sizeof(void *)), "vtable pointer layout");