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How to make unwind info always present?
- From: "Ulrich Weigand" <Ulrich dot Weigand at de dot ibm dot com>
- To: gcc at gcc dot gnu dot org
- Date: Thu, 14 Nov 2002 19:09:10 +0100
- Subject: How to make unwind info always present?
- Sensitivity:
Hello,
we are thinking of changing the debug setup for s390 to always use
DWARF-2 frame data for stack unwinding (e.g. backtraces).
This has two main advantages:
- we are currently maintaining an explicit stack frame back-chain
pointer, which causes (measurable) run-time overhead for no other
purpose but to enable debugging. With DWARF-2 info, there would
be no run-time overhead.
- with the introduction of prolog scheduling, our gdb backend has
serious problems trying to figure out where the prolog ends and
all variables are set up; this makes debugging with current gdb
and gcc quite awkward. DWARF-2 frame info would solve this.
My question is now how to best set up gcc so as to always generate
this info. Are there other platforms that use a similar approach?
Is it possible to avoid duplication of this data if DWARF-2 frame
info is also needed for exception handling?
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
Phone: +49-7031/16-3727 --- Email: Ulrich.Weigand@de.ibm.com