[PATCH] RTEMS: Use strict DWARF-2 on ARM, PowerPC, SPARC
chrisj at rtems.org
Tue Jun 18 23:54:56 UTC 2013
Sebastian Huber wrote:
> Some debuggers do not cope with the new DWARF3/4 debug format introduced
> with GCC 4.8. Default to strict DWARF-2 on ARM, PowerPC and SPARC for
> This patch should be committed to GCC 4.8 and 4.9.
I am not convinced about this change on technical grounds. When I say I
am not convinced, I am not sure what we gain and what we give up and I
would like to understand that a little better before agreeing to it.
I should also point out I am using ARM with gcc-4.8.1 and gdb-7.6 and it
is working well (my OpenOCD changes need more work) and any change to
DWARF2 that alters this would be a regression.
I have taken a look at the differences between DWARF2, DWARF3 and
DWARF4. There is better language support in the later versions and debug
data compression. These improvements are nice. What I am not sure about
is the way limiting gcc to DWARF2 effects the debugging experience. If
the flag is just a format change and the experience is the same that is
ok, if however the C++ or C debugging experience is reduced that would
be a regression.
My major concern is locking us into this and it being forgotten and we
sit on DWARF2 for ages and we do not see or notice regressions related
to DWARF3/4 when it breaks on these archs. Can ARM/PowerPC/SPARC tools
be built with a target option that limits the target libraries to DWARF2 ?
Did a gdb bug get raised about the DWARF read error reported on the
mailing list ?
More information about the devel