Rewrite record layout for ms_struct structs.
The old implementation of ms_struct in RecordLayoutBuilder was a
complete mess: it depended on complicated conditionals which didn't
really reflect the underlying logic, and placed a burden on users of
the resulting RecordLayout. This commit rips out almost all of the
old code, and replaces it with simple checks in
RecordLayoutBuilder::LayoutBitField.
This commit also fixes <rdar://problem/14252115>, a bug where class
inheritance would cause us to lay out bitfields incorrectly.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185018 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index 3e13e97..c06cf2f 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -373,30 +373,16 @@
unsigned FieldNo = 0;
unsigned ElementNo = 0;
- const FieldDecl *LastFD = 0;
- bool IsMsStruct = RD->isMsStruct(CGM.getContext());
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are
- // ignored:
- if (CGM.getContext().ZeroBitfieldFollowsNonBitfield(*Field, LastFD)) {
- --FieldNo;
- continue;
- }
- LastFD = *Field;
- }
-
// If this is a union, skip all the fields that aren't being initialized.
if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
continue;
// Don't emit anonymous bitfields, they just affect layout.
- if (Field->isUnnamedBitfield()) {
- LastFD = *Field;
+ if (Field->isUnnamedBitfield())
continue;
- }
// Get the initializer. A struct can include fields without initializers,
// we just use explicit null values for them.
@@ -472,31 +458,17 @@
}
unsigned FieldNo = 0;
- const FieldDecl *LastFD = 0;
- bool IsMsStruct = RD->isMsStruct(CGM.getContext());
uint64_t OffsetBits = CGM.getContext().toBits(Offset);
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are
- // ignored:
- if (CGM.getContext().ZeroBitfieldFollowsNonBitfield(*Field, LastFD)) {
- --FieldNo;
- continue;
- }
- LastFD = *Field;
- }
-
// If this is a union, skip all the fields that aren't being initialized.
if (RD->isUnion() && Val.getUnionField() != *Field)
continue;
// Don't emit anonymous bitfields, they just affect layout.
- if (Field->isUnnamedBitfield()) {
- LastFD = *Field;
+ if (Field->isUnnamedBitfield())
continue;
- }
// Emit the value of the initializer.
const APValue &FieldValue =