On Mon, 2009-01-19 at 17:08 -0800, Ian Lance Taylor wrote: > biju64 <alex.jacob@xxxxxxxxxx> writes: > > > What about the libgcc_s.a library that we have to link in if using gcc ? Do > > I need to worry about this ? > > On google I see something called libgcc_s_pthread.a - What does this do ? Do > > I need this ? > > gcc's supporting libraries are all thread-safe. > > I don't know what libgcc_s_pthread.a is--it's not part of a regular > gcc distribution. Err - it is not part of a _recent_ (>= gcc-4) on *AIX* any more, but up to gcc-3.4, these libgcc_s* were provided by gcc on AIX: $ cd /prefix/of/gcc-3.x $ find . -name 'libgcc_s* ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/libgcc_s.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/libgcc_s_pthread.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/libgcc_s_ppc64.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/libgcc_s_pthread_ppc64.a and theses were the libstdc++* ones: $ find . -name '*.la' -prune -o -name 'libstdc++*' -print ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/pthread/ppc64/libstdc++.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/pthread/libstdc++.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/ppc64/libstdc++.a ./lib/gcc/powerpc-ibm-aix5.3.0.0/3.4.5/libstdc++.a Note: These are the _shared_ libraries on AIX. I've always tried hard to _not_ have pthread- and non-pthread-variants of both libgcc_s (distinguished by filename) and libstdc++ (distinguished by path) as runtime dependencies of my shared libraries and executables. In the end, I patched the gcc source (specs) to always behave as if '-pthread' was passed on the commandline, but it also should work to have a wrapper-script that always passes '-pthread'. Even if I did not necessarily use pthreads in my application, I could not be sure that each required library was built without -pthread. So I built each library where I have sourcecode for using that patched gcc. Having pthreads enabled always does not really hurt, even when not used. Since gcc-4.1 (haven't tried gcc-4.0), the pthread-specific libs are gone, but I still patch gcc-source to enable pthreads always. I'm not sure if it is really necessary any more, but it still works. HTH, /haubi/
