[Lldb-commits] [lldb] Fix a bug where an error was emitted for GCC union types. (PR #159401)

[Michael Buch via lldb-commits]

================
@@ -3142,7 +3142,11 @@ void DWARFASTParserClang::ParseSingleMember(
       uint64_t parent_byte_size =
           parent_die.GetAttributeValueAsUnsigned(DW_AT_byte_size, UINT64_MAX);
 
-      if (attrs.member_byte_offset >= parent_byte_size) {
+      // If the attrs.member_byte_offset is still set to UINT32_MAX this means
+      // that the DW_TAG_member didn't have a DW_AT_data_member_location, so
+      // don't emit an error if this is the case.
+      if (attrs.member_byte_offset != UINT32_MAX &&
----------------
Michael137 wrote:

LGTM

Though there's a couple of follow-ups i think we could do:
1. Would be nice if `member_byte_offset` was an optional
2. Why is Clang emitting `DW_AT_data_member_location` for union members? Aren't they always `0x0` anyway. I assume that's why GCC chooses to omit them. Would be nice for Clang and GCC to align on this.
3. This condition seems silly:
```
member_array_size != 1 &&
            (member_array_size != 0 ||
             attrs.member_byte_offset > parent_byte_size
```

The `!= 0` is always `false` right?

https://github.com/llvm/llvm-project/pull/159401