[RFA/dwarf-2] Fix for the null record problem

[Joel Brobecker <brobecker at gnat dot com>]

Hello,

This is a followup on the thread that started with:

   http://sources.redhat.com/ml/gdb-patches/2004-02/msg00058.html

The test proposed under that thread was dropped because an empty
struct is not legal C. However, it is legal in Ada, and I've seen
a message saying that it is also legal in C++.

I have found the source of the problem, and suggest the attached patch.
The problem was that GDB was mistakenly deducing that the empry record
was only a stub because of the lack of fields, and was therefore tagging
it with TYPE_FLAG_STUB. This is not correct. Instead, the right
approach, I believe, is to check for the DW_AT_declaration attribute.

2004-02-19  J. Brobecker  <brobecker@gnat.com>

        * dwarf2read.c (read_structure_scope): Identify stub types
        using the DW_AT_declaration attribute.

tested on x86-linux. No regression. Fixes the testcase that was
proposed by Andrew (even though it is not legal C) and the Ada
case.

OK to apply?

Thanks,
-- 
Joel

PS: BTW, my past 3 months of traveling will soon be over. The past
couple of weeks have been very hectic. I have noticed that there were
some messages directed at me to which I haven't answered yet. I am
really sorry. I have kept these messages and will try to answer them
soon.

Attachment: null_record.diff
Description: Text document