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/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 9d2b23e..d191073 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -915,10 +915,6 @@
// Field number for non-static fields.
unsigned fieldNo = 0;
- // Bookkeeping for an ms struct, which ignores certain fields.
- bool IsMsStruct = record->isMsStruct(CGM.getContext());
- const FieldDecl *LastFD = 0;
-
// Static and non-static members should appear in the same order as
// the corresponding declarations in the source program.
for (RecordDecl::decl_iterator I = record->decls_begin(),
@@ -926,13 +922,6 @@
if (const VarDecl *V = dyn_cast<VarDecl>(*I))
CollectRecordStaticField(V, elements, RecordTy);
else if (FieldDecl *field = dyn_cast<FieldDecl>(*I)) {
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are
- // completely ignored; we don't even count them.
- if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((field), LastFD))
- continue;
- LastFD = field;
- }
CollectRecordNormalField(field, layout.getFieldOffset(fieldNo),
tunit, elements, RecordTy);
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 =
diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index 30ab528..8d692c5 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -78,9 +78,6 @@
/// Packed - Whether the resulting LLVM struct will be packed or not.
bool Packed;
-
- /// IsMsStruct - Whether ms_struct is in effect or not
- bool IsMsStruct;
private:
CodeGenTypes &Types;
@@ -195,8 +192,7 @@
CGRecordLayoutBuilder(CodeGenTypes &Types)
: BaseSubobjectType(0),
IsZeroInitializable(true), IsZeroInitializableAsBase(true),
- Packed(false), IsMsStruct(false),
- Types(Types) { }
+ Packed(false), Types(Types) { }
/// Layout - Will layout a RecordDecl.
void Layout(const RecordDecl *D);
@@ -207,8 +203,6 @@
void CGRecordLayoutBuilder::Layout(const RecordDecl *D) {
Alignment = Types.getContext().getASTRecordLayout(D).getAlignment();
Packed = D->hasAttr<PackedAttr>();
-
- IsMsStruct = D->isMsStruct(Types.getContext());
if (D->isUnion()) {
LayoutUnion(D);
@@ -764,20 +758,10 @@
return false;
unsigned FieldNo = 0;
- const FieldDecl *LastFD = 0;
for (RecordDecl::field_iterator FI = D->field_begin(), FE = D->field_end();
FI != FE; ++FI, ++FieldNo) {
FieldDecl *FD = *FI;
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are
- // ignored:
- if (Types.getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD)) {
- --FieldNo;
- continue;
- }
- LastFD = FD;
- }
// If this field is a bitfield, layout all of the consecutive
// non-zero-length bitfields and the last zero-length bitfield; these will
@@ -1028,8 +1012,6 @@
const ASTRecordLayout &AST_RL = getContext().getASTRecordLayout(D);
RecordDecl::field_iterator it = D->field_begin();
- const FieldDecl *LastFD = 0;
- bool IsMsStruct = D->isMsStruct(getContext());
for (unsigned i = 0, e = AST_RL.getFieldCount(); i != e; ++i, ++it) {
const FieldDecl *FD = *it;
@@ -1039,25 +1021,12 @@
unsigned FieldNo = RL->getLLVMFieldNo(FD);
assert(AST_RL.getFieldOffset(i) == SL->getElementOffsetInBits(FieldNo) &&
"Invalid field offset!");
- LastFD = FD;
continue;
}
-
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are
- // ignored:
- if (getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD)) {
- --i;
- continue;
- }
- LastFD = FD;
- }
// Ignore unnamed bit-fields.
- if (!FD->getDeclName()) {
- LastFD = FD;
+ if (!FD->getDeclName())
continue;
- }
// Don't inspect zero-length bitfields.
if (FD->getBitWidthValue(getContext()) == 0)
diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp
index 3f0eaee..f299481 100644
--- a/lib/CodeGen/CodeGenTBAA.cpp
+++ b/lib/CodeGen/CodeGenTBAA.cpp
@@ -203,18 +203,8 @@
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
unsigned idx = 0;
- const FieldDecl *LastFD = 0;
- bool IsMsStruct = RD->isMsStruct(Context);
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i, ++idx) {
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are ignored.
- if (Context.ZeroBitfieldFollowsNonBitfield(*i, LastFD)) {
- --idx;
- continue;
- }
- LastFD = *i;
- }
uint64_t Offset = BaseOffset +
Layout.getFieldOffset(idx) / Context.getCharWidth();
QualType FieldQTy = i->getType();
@@ -278,19 +268,8 @@
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
SmallVector <std::pair<llvm::MDNode*, uint64_t>, 4> Fields;
unsigned idx = 0;
- const FieldDecl *LastFD = 0;
- bool IsMsStruct = RD->isMsStruct(Context);
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i, ++idx) {
- if (IsMsStruct) {
- // Zero-length bitfields following non-bitfield members are ignored.
- if (Context.ZeroBitfieldFollowsNonBitfield(*i, LastFD)) {
- --idx;
- continue;
- }
- LastFD = *i;
- }
-
QualType FieldQTy = i->getType();
llvm::MDNode *FieldNode;
if (isTBAAPathStruct(FieldQTy))