Re: [gentoo-dev] Split ELF Debug (default or not?)
On 26/11/2005 13:55:25, Ned Ludd ([EMAIL PROTECTED]) wrote: On Sat, 2005-11-26 at 19:30 +0100, Bruno wrote: What's the advantage of splitting out the debug info to some extra location instead of leaving it in the original binary (maybe smaller foot-print in memory while the debugging info is not used), Yes exactly a stripped binary will occupy less space in RAM. I may be wrong, but I don't think this is true. As I understand it, debug sections aren't part of the PT_LOAD segments so the loader won't load them into memory. -- gentoo-dev@gentoo.org mailing list
Re: [gentoo-dev] Split ELF Debug (default or not?)
On Sun, 2005-11-27 at 10:53 +0100, Kevin F. Quinn wrote: On 26/11/2005 13:55:25, Ned Ludd ([EMAIL PROTECTED]) wrote: On Sat, 2005-11-26 at 19:30 +0100, Bruno wrote: What's the advantage of splitting out the debug info to some extra location instead of leaving it in the original binary (maybe smaller foot-print in memory while the debugging info is not used), Yes exactly a stripped binary will occupy less space in RAM. I may be wrong, but I don't think this is true. As I understand it, debug sections aren't part of the PT_LOAD segments so the loader won't load them into memory. See the objcopy manpage. Look for the --only-keep-debug section. The entire elf has to be mmaped before individual sections are mapped. -- Ned Ludd [EMAIL PROTECTED] Gentoo Linux -- gentoo-dev@gentoo.org mailing list
Re: [gentoo-dev] Split ELF Debug (default or not?)
On Sat, 2005-11-26 at 23:42 +0200, Petteri Räty wrote:
Ned Ludd wrote:
Good afternoon,
Would you be willing to give up space in $ROOT/usr/lib/debug for ELF
executables by default in order to aid in better debugging by or do we
want to only emit it when a FEATURE= is defined.
Having a split debug pretty much obsoletes the need to add nostrip to
your features in order to get debug info.
Users wishing to not have debug info can simply add
INSTALL_MASK=/usr/lib/debug ${INSTALL_MASK} to make.conf or the
environment unless we make it FEATURE based.
I'm in favor of it enabled per default but I'd like to know what you
think and why. (advantages of on/off by default etc..)
How useful is this debug information with -fomit-frame-pointer? From
what I have read it makes debugging at least harder. I think most people
have -fomit-frame-pointer in their CFLAGS so it should not be enabled by
default if the debug info is not very useful any way.
Regards,
Petteri
-fomit-frame-pointer does indeed make certain aspects of debugging
harder but it does not moot the idea entirely.
--
Ned Ludd [EMAIL PROTECTED]
Gentoo Linux
--
gentoo-dev@gentoo.org mailing list
Re: [gentoo-dev] Split ELF Debug (default or not?)
On Sat, 2005-11-26 at 19:30 +0100, Bruno wrote: [snip] What's the advantage of splitting out the debug info to some extra location instead of leaving it in the original binary (maybe smaller foot-print in memory while the debugging info is not used), Yes exactly a stripped binary will occupy less space in RAM. and what tools are compatible with this external debug info? gdb being the main one. With tools like valgrind you can simply do. LD_LIBRARY_PATH=/usr/lib/debug valgrind --foo ELF is cool like that. -- Ned Ludd [EMAIL PROTECTED] Gentoo Linux -- gentoo-dev@gentoo.org mailing list
