Debug Info: Don't emit a DW_AT_data_member_location for DWARF bitfields.

The DWARF spec states that a member entry may have either a
DW_AT_data_member_location or a DW_AT_data_bit_offset, but not both.

This fixes a bug found in PR 27758.

llvm-svn: 269731

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 4011934c26f..f8c3f489ca4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1390,8 +1390,8 @@ void DwarfUnit::constructMemberDIE(DIE &Buffer, const DIDerivedType *DT) {
     uint64_t Size = DT->getSizeInBits();
     uint64_t FieldSize = getBaseTypeSize(DD, DT);
     uint64_t OffsetInBytes;
-
-    if (FieldSize && Size != FieldSize) {
+    bool IsBitfield = FieldSize && Size != FieldSize;
+    if (IsBitfield) {
       // Handle bitfield, assume bytes are 8 bits.
       if (DD->getDwarfVersion() < 4)
         addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8);
@@ -1428,7 +1428,7 @@ void DwarfUnit::constructMemberDIE(DIE &Buffer, const DIDerivedType *DT) {
       addUInt(*MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
       addUInt(*MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes);
       addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie);
-    } else
+    } else if (!IsBitfield || DD->getDwarfVersion() < 4)
       addUInt(MemberDie, dwarf::DW_AT_data_member_location, None,
               OffsetInBytes);
   }