Re: [Libunwind-devel] Build glibc linking libunwind

[Ken Werner]

On 09/24/2011 11:46 PM, Fabio wrote:
> Hi all,
> I am trying to build glibc and link libunwind to get a backtrace at
> the beginning of some glibc function like strcpy for example but I
> can't get them to build.
> I include -lunwind in the CFLAGS and I export
> LD_LIBRARY_PATH=/usr/local/lib, but when it comes to build ld.so it
> fails:
>
> /home/wintermute/tesi/glibc/2.14/custom/glibc-2.14/string/strcpy.c:43:
> undefined reference to `_Ux86_getcontext'
> /home/wintermute/tesi/glibc/2.14/custom/glibc-2.14/string/strcpy.c:44:
> undefined reference to `_ULx86_init_local'
> collect2: ld returned 1 exit status
>
> Am I missing something? Sorry for asking a dumb question and thanks in advance.

I suspect you're on a system where the linker does not pull in indirect 
shared libs (the default behavior of recent Debian or Fedora based 
distros). I had a similar issue - see: 
http://lists.gnu.org/archive/html/libunwind-devel/2011-03/msg00002.html. 
You're probably just missing to link against libunwind-x86_64.so. Adding 
-lunwind-x86 to your CLFAGS/LDFLAGS should be sufficient.

Regards
Ken