[PATCH] --enable-linker-build-id by default

[Alexandre Oliva]

On Oct  5, 2010, Roland McGrath <roland@redhat.com> wrote:

>> Alex, can this do something bad to bootstrap-debug?  I wonder if having 
>> different -g settings for stage2 and stage3 would cause different build 
>> IDs and ultimately cause a comparison script.

> Different output of any kind (including DWARF and symbol tables) in the
> final linked binaries will produce different build IDs, yes.

As long as the build IDs are in executables, rather than in object
files, we should be fine.  The -checksum object files, used to ensure
compatibility with precompiled headers, will end up different if the
buildids change, because other portions of the binary are different, but
we already disregard differences in the -checksum object files anyway,
and we did even before compare-debug came into the picture.

I wonder if it would make sense to use the compiler's buildid for this
purpose.  Roland, is it possible/easy for a running executable to obtain
its own buildid?

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer