Re: Glibc building procedure error report.

[Samuel Thibault]

Ludovic Courtès, le Sat 05 Apr 2014 15:36:17 +0200, a écrit :
> Samuel Thibault <samuel.thibault@gnu.org> skribis:
> 
> > Manolis Ragkousis, le Wed 02 Apr 2014 00:29:13 +0000, a écrit :
> >> >  /../build/libc_pic.os: In function `__fork':
> >> >  /../source/posix/../sysdeps/mach/hurd/fork.c:71: undefined reference to 
> >> > `__start__hurd_atfork_prepare_hook'
> >> >  /../gcc-cross-sans-libc-i686-pc-gnu-4.8.2/libexec/gcc/i686-pc-gnu/ld: 
> >> > /../build/libc_pic.os: relocation R_386_GOTOFF against undefined hidden 
> >> > >  symbol `__start__hurd_atfork_prepare_hook' can not be used when 
> >> > making a shared object
> >> >  /../gcc-cross-sans-libc-i686-pc-gnu-4.8.2/libexec/gcc/i686-pc-gnu/ld: 
> >> > final link failed: Bad value
> >> >  collect2: error: ld returned 1 exit status
> >> >  ../Makerules:614: recipe for target '/../build/libc.so' failed
> >> >  make[2]: *** 
> >> > [/tmp/nix-build-glibc-hurd-cross-i686-pc-gnu-2.18.drv-38/build/libc.so] 
> >> > Error 1
> >> >  make[2]: Leaving directory 
> >> > '/tmp/nix-build-glibc-hurd-cross-i686-pc-gnu-2.18.drv-38/source/elf'
> >> >  Makefile:233: recipe for target 'elf/subdir_lib' failed
> >> 
> >> I searched the source files in posix and sysdeps/mach/hurd/ and I
> >> can't seem to find any reference to
> >> `__start__hurd_atfork_prepare_hook'.
> >> 
> >> Any ideas?
> >
> > In such cases, look for subparts of the name, here atfork_prepare, and
> > you'll see 
> >
> > sysdeps/mach/hurd/fork.c:DEFINE_HOOK (_hurd_atfork_prepare_hook, (void));
> >
> > The symbol is supposed to be defined automagically by the linker.  I
> > don't know how exactly.
> 
> The linker magic is in the shlib.lds rules of Makerules, added in commit
> 56798c44 of glibc/Savannah.
> 
> However, it adds the start/stop symbols for the hurd_fork hooks, but not
> for the hurd_atfork hooks.  Do we need something like this:

Yes, and you can use it for now, but as Roland said it should be
automatically added by the linker, we should probably investigate why
this is not the case in some situations.

Samuel