S/390: Default to -fasynchronous-unwind-tables

[Ulrich Weigand]

Jakub Jelinek wrote:

>But without .symtab/.strtab the backtraces aren't much useful anyway.
>Which is not much different from making sure .debug_frame stays.

Not really.  Even without symbolic names, a backtrace is still useful.
Also, you can build those parts you are interested in with debug info,
so a backtrace will show *those* symbols at least, even if you actually
crash in a system library.

But without backtrace, you can basically do nothing.

>> While you could certainly say that they should just build the app
>> with -g1, this doesn't help if the crash happens in a library routine.
>> One solution would be to build all system libraries also with -g1,
>> which we had considered, but this has the disadvantage that 'strip'
>> removes the information (and the usual RPM build process strips all
>> binaries and libraries) ...
>
>This is changing.

Well, that would also be an option.  But I don't quite see why this
would be an improvement over using -fasynchronous-unwind-tables,
seeing as -g1 takes significantly more space, and additionally duplicates
.eh_frame info where that is needed anyway ...


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

--
  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
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