fixup! add helper wrappers for isEmptyField/isEmptyRecord

Author: Michael137

clang/lib/CodeGen/ABIInfoImpl.cpp

@@ -289,6 +289,16 @@ bool CodeGen::isEmptyField(const ASTContext &Context, const FieldDecl *FD,
   return isEmptyRecord(Context, FT, AllowArrays, AsIfNoUniqueAddr);
 }
 
+bool CodeGen::isEmptyFieldForLayout(const ASTContext &Context, const FieldDecl *FD) {
+  if (FD->isZeroLengthBitField(Context))
+    return true;
+  
+  if (FD->isUnnamedBitField())
+    return false;
+
+  return isEmptyField(Context, FD, /*AllowArrays=*/false, /*AsIfNoUniqueAddr=*/true);
+}
+
 bool CodeGen::isEmptyRecord(const ASTContext &Context, QualType T,
                             bool AllowArrays, bool AsIfNoUniqueAddr) {
   const RecordType *RT = T->getAs<RecordType>();
@@ -310,6 +320,10 @@ bool CodeGen::isEmptyRecord(const ASTContext &Context, QualType T,
   return true;
 }
 
+bool CodeGen::isEmptyRecordForLayout(const ASTContext &Context, QualType T) {
+  return isEmptyRecord(Context, T, /*AllowArrays=*/false, /*AsIfNoUniqueAddr=*/true);
+}
+
 const Type *CodeGen::isSingleElementStruct(QualType T, ASTContext &Context) {
   const RecordType *RT = T->getAs<RecordType>();
   if (!RT)

clang/lib/CodeGen/ABIInfoImpl.h

@@ -129,6 +129,10 @@ Address emitMergePHI(CodeGenFunction &CGF, Address Addr1,
 bool isEmptyField(const ASTContext &Context, const FieldDecl *FD,
                   bool AllowArrays, bool AsIfNoUniqueAddr = false);
 
+/// isEmptyFieldForLayout - Return true iff the field is "empty", that is,
+/// either a zero-width bit-field or an empty record.
+bool isEmptyFieldForLayout(const ASTContext &Context, const FieldDecl *FD);
+
 /// isEmptyRecord - Return true iff a structure contains only empty
 /// fields. Note that a structure with a flexible array member is not
 /// considered empty. If AsIfNoUniqueAddr is true, then C++ record fields are
@@ -137,6 +141,11 @@ bool isEmptyField(const ASTContext &Context, const FieldDecl *FD,
 bool isEmptyRecord(const ASTContext &Context, QualType T, bool AllowArrays,
                    bool AsIfNoUniqueAddr = false);
 
+/// isEmptyRecordForLayout - Return true iff a structure contains only empty
+/// fields. Note, C++ record fields are considered empty if the
+/// [[no_unique_address]] attribute would have made them empty.
+bool isEmptyRecordForLayout(const ASTContext &Context, QualType T);
+
 /// isSingleElementStruct - Determine if a structure is a "single
 /// element struct", i.e. it has exactly one non-empty field or
 /// exactly one field which is itself a single element

clang/lib/CodeGen/CGExpr.cpp

@@ -4763,7 +4763,7 @@ static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
 /// The resulting address doesn't necessarily have the right type.
 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
                                       const FieldDecl *field) {
-  if (isEmptyField(CGF.getContext(), field, false, true))
+  if (isEmptyFieldForLayout(CGF.getContext(), field))
     return emitAddrOfZeroSizeField(CGF, base, field);
 
   const RecordDecl *rec = field->getParent();

clang/lib/CodeGen/CGExprConstant.cpp

@@ -2482,7 +2482,7 @@ static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
         cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
 
       // Ignore empty bases.
-      if (isEmptyRecord(CGM.getContext(), I.getType(), false, true) ||
+      if (isEmptyRecordForLayout(CGM.getContext(), I.getType()) ||
           CGM.getContext()
               .getASTRecordLayout(base)
               .getNonVirtualSize()
@@ -2521,7 +2521,7 @@ static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
         cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
 
       // Ignore empty bases.
-      if (isEmptyRecord(CGM.getContext(), I.getType(), false, true))
+      if (isEmptyRecordForLayout(CGM.getContext(), I.getType()))
         continue;
 
       unsigned fieldIndex = layout.getVirtualBaseIndex(base);

clang/lib/CodeGen/CGRecordLayoutBuilder.cpp

@@ -385,7 +385,7 @@ void CGRecordLowering::accumulateFields(bool isNonVirtualBaseType) {
       Field = accumulateBitFields(isNonVirtualBaseType, Field, FieldEnd);
       assert((Field == FieldEnd || !Field->isBitField()) &&
              "Failed to accumulate all the bitfields");
-    } else if (isEmptyField(Context, *Field, false, true)) {
+    } else if (isEmptyFieldForLayout(Context, *Field)) {
       // Empty fields have no storage.
       ++Field;
     } else {
@@ -635,9 +635,7 @@ CGRecordLowering::accumulateBitFields(bool isNonVirtualBaseType,
           // non-reusable tail padding.
           CharUnits LimitOffset;
           for (auto Probe = Field; Probe != FieldEnd; ++Probe)
-            if (!Probe->isZeroLengthBitField(Context) &&
-                !(isEmptyField(Context, *Probe, false, true) &&
-                  !Probe->isBitField())) {
+            if (!isEmptyFieldForLayout(Context, *Probe)) {
               // A member with storage sets the limit.
               assert((getFieldBitOffset(*Probe) % CharBits) == 0 &&
                      "Next storage is not byte-aligned");
@@ -735,7 +733,7 @@ void CGRecordLowering::accumulateBases() {
     // Bases can be zero-sized even if not technically empty if they
     // contain only a trailing array member.
     const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
-    if (!isEmptyRecord(Context, Base.getType(), false, true) &&
+    if (!isEmptyRecordForLayout(Context, Base.getType()) &&
         !Context.getASTRecordLayout(BaseDecl).getNonVirtualSize().isZero())
       Members.push_back(MemberInfo(Layout.getBaseClassOffset(BaseDecl),
           MemberInfo::Base, getStorageType(BaseDecl), BaseDecl));
@@ -883,7 +881,7 @@ CGRecordLowering::calculateTailClippingOffset(bool isNonVirtualBaseType) const {
   if (!isNonVirtualBaseType && isOverlappingVBaseABI())
     for (const auto &Base : RD->vbases()) {
       const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
-      if (isEmptyRecord(Context, Base.getType(), false, true))
+      if (isEmptyRecordForLayout(Context, Base.getType()))
         continue;
       // If the vbase is a primary virtual base of some base, then it doesn't
       // get its own storage location but instead lives inside of that base.
@@ -899,7 +897,7 @@ CGRecordLowering::calculateTailClippingOffset(bool isNonVirtualBaseType) const {
 void CGRecordLowering::accumulateVBases() {
   for (const auto &Base : RD->vbases()) {
     const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
-    if (isEmptyRecord(Context, Base.getType(), false, true))
+    if (isEmptyRecordForLayout(Context, Base.getType()))
       continue;
     CharUnits Offset = Layout.getVBaseClassOffset(BaseDecl);
     // If the vbase is a primary virtual base of some base, then it doesn't
@@ -1165,8 +1163,7 @@ CodeGenTypes::ComputeRecordLayout(const RecordDecl *D, llvm::StructType *Ty) {
     const FieldDecl *FD = *it;
 
     // Ignore zero-sized fields.
-    if (FD->isZeroLengthBitField(Context) ||
-        (isEmptyField(Context, FD, false, true) && !FD->isBitField()))
+    if (isEmptyFieldForLayout(getContext(), FD))
       continue;
 
     // For non-bit-fields, just check that the LLVM struct offset matches the