Finish off rules for z-length bitfields in ms_struct
structs. // rdar://8823265
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130783 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index b21ba9a..e336dd7 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -2059,8 +2059,7 @@
if (IsMsStruct) {
// Zero-length bitfields following non-bitfield members are ignored.
- if (getASTContext().ZeroBitfieldFollowsNonBitfield((*i), LastFD) ||
- getASTContext().ZeroBitfieldFollowsBitfield((*i), LastFD)) {
+ if (getASTContext().ZeroBitfieldFollowsNonBitfield((*i), LastFD)) {
++i;
continue;
}
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 0770e1f..810f11b 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -582,7 +582,7 @@
CharUnits NonVirtualSize;
CharUnits NonVirtualAlignment;
- CharUnits ZeroLengthBitfieldAlignment;
+ FieldDecl *ZeroLengthBitfield;
/// PrimaryBase - the primary base class (if one exists) of the class
/// we're laying out.
@@ -621,7 +621,7 @@
UnfilledBitsInLastByte(0), MaxFieldAlignment(CharUnits::Zero()),
DataSize(0), NonVirtualSize(CharUnits::Zero()),
NonVirtualAlignment(CharUnits::One()),
- ZeroLengthBitfieldAlignment(CharUnits::Zero()), PrimaryBase(0),
+ ZeroLengthBitfield(0), PrimaryBase(0),
PrimaryBaseIsVirtual(false), FirstNearlyEmptyVBase(0) { }
void Layout(const RecordDecl *D);
@@ -1258,22 +1258,16 @@
// Layout each field, for now, just sequentially, respecting alignment. In
// the future, this will need to be tweakable by targets.
const FieldDecl *LastFD = 0;
+ ZeroLengthBitfield = 0;
for (RecordDecl::field_iterator Field = D->field_begin(),
FieldEnd = D->field_end(); Field != FieldEnd; ++Field) {
if (IsMsStruct) {
- const FieldDecl *FD = (*Field);
- if (Context.ZeroBitfieldFollowsBitfield(FD, LastFD)) {
- // FIXME. Multiple zero bitfields may follow a bitfield.
- // set ZeroLengthBitfieldAlignment to max. of its
- // currrent and alignment of 'FD'.
- std::pair<CharUnits, CharUnits> FieldInfo =
- Context.getTypeInfoInChars(FD->getType());
- ZeroLengthBitfieldAlignment = FieldInfo.second;
- continue;
- }
+ FieldDecl *FD = (*Field);
+ if (Context.ZeroBitfieldFollowsBitfield(FD, LastFD))
+ ZeroLengthBitfield = FD;
// Zero-length bitfields following non-bitfield members are
// ignored:
- if (Context.ZeroBitfieldFollowsNonBitfield(FD, LastFD))
+ else if (Context.ZeroBitfieldFollowsNonBitfield(FD, LastFD))
continue;
LastFD = FD;
}
@@ -1355,6 +1349,21 @@
std::pair<uint64_t, unsigned> FieldInfo = Context.getTypeInfo(D->getType());
uint64_t TypeSize = FieldInfo.first;
unsigned FieldAlign = FieldInfo.second;
+
+ if (ZeroLengthBitfield) {
+ // If a zero-length bitfield is inserted after a bitfield,
+ // and the alignment of the zero-length bitfield is
+ // greater than the member that follows it, `bar', `bar'
+ // will be aligned as the type of the zero-length bitfield.
+ if (ZeroLengthBitfield != D) {
+ std::pair<uint64_t, unsigned> FieldInfo =
+ Context.getTypeInfo(ZeroLengthBitfield->getType());
+ unsigned ZeroLengthBitfieldAlignment = FieldInfo.second;
+ if (ZeroLengthBitfieldAlignment > FieldAlign)
+ FieldAlign = ZeroLengthBitfieldAlignment;
+ ZeroLengthBitfield = 0;
+ }
+ }
if (FieldSize > TypeSize) {
LayoutWideBitField(FieldSize, TypeSize, FieldPacked, D);
@@ -1455,9 +1464,19 @@
Context.getTypeInfoInChars(D->getType());
FieldSize = FieldInfo.first;
FieldAlign = FieldInfo.second;
- if (ZeroLengthBitfieldAlignment > FieldAlign)
- FieldAlign = ZeroLengthBitfieldAlignment;
- ZeroLengthBitfieldAlignment = CharUnits::Zero();
+
+ if (ZeroLengthBitfield) {
+ // If a zero-length bitfield is inserted after a bitfield,
+ // and the alignment of the zero-length bitfield is
+ // greater than the member that follows it, `bar', `bar'
+ // will be aligned as the type of the zero-length bitfield.
+ std::pair<CharUnits, CharUnits> FieldInfo =
+ Context.getTypeInfoInChars(ZeroLengthBitfield->getType());
+ CharUnits ZeroLengthBitfieldAlignment = FieldInfo.second;
+ if (ZeroLengthBitfieldAlignment > FieldAlign)
+ FieldAlign = ZeroLengthBitfieldAlignment;
+ ZeroLengthBitfield = 0;
+ }
if (Context.getLangOptions().MSBitfields) {
// If MS bitfield layout is required, figure out what type is being
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 06c4d39..38bfcf2 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -628,8 +628,7 @@
FieldDecl *field = *I;
if (IsMsStruct) {
// Zero-length bitfields following non-bitfield members are ignored
- if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((field), LastFD) ||
- CGM.getContext().ZeroBitfieldFollowsBitfield((field), LastFD)) {
+ if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((field), LastFD)) {
--fieldNo;
continue;
}
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index 463b913..8054d4b 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -352,8 +352,7 @@
if (IsMsStruct) {
// Zero-length bitfields following non-bitfield members are
// ignored:
- if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((*Field), LastFD) ||
- CGM.getContext().ZeroBitfieldFollowsBitfield((*Field), LastFD)) {
+ if (CGM.getContext().ZeroBitfieldFollowsNonBitfield((*Field), LastFD)) {
--FieldNo;
continue;
}
diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index a4ac390..3d9fd88 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -753,8 +753,7 @@
// Zero-length bitfields following non-bitfield members are
// ignored:
const FieldDecl *FD = (*Field);
- if (Types.getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD) ||
- Types.getContext().ZeroBitfieldFollowsBitfield(FD, LastFD)) {
+ if (Types.getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD)) {
--FieldNo;
continue;
}
@@ -997,8 +996,7 @@
if (IsMsStruct) {
// Zero-length bitfields following non-bitfield members are
// ignored:
- if (getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD) ||
- getContext().ZeroBitfieldFollowsBitfield(FD, LastFD)) {
+ if (getContext().ZeroBitfieldFollowsNonBitfield(FD, LastFD)) {
--i;
continue;
}