[CMake] Specify 32-bit compilation to Clang

[Robert Dailey]

Thanks for your help so far. Your 3rd command produced the output
below. I'll keep looking into this but just wanted to share. I'm not
sure why it isn't working, and I'm not completely familiar with linux
development so it will take me a while to figure this out.

robert at robert-OptiPlex-745 ~ $ clang++ -m32 -Wl,--verbose test.cpp|grep libgcc
/usr/bin/ld: skipping incompatible
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libstdc++.so when searching
for -lstdc++
/usr/bin/ld: skipping incompatible
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libstdc++.a when searching
for -lstdc++
/usr/bin/ld: cannot find -lstdc++
/usr/bin/ld: skipping incompatible
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc_s.so when searching
for -lgcc_s
attempt to open /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc_s.so succeeded
/usr/bin/ld: cannot find -lgcc_s
attempt to open /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc_s.a failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../i386-linux-gnu/libgcc_s.so
failed
/usr/bin/ld: skipping incompatible
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc.a when searching for
-lgcc
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../i386-linux-gnu/libgcc_s.a
failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../lib32/libgcc_s.so
failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../lib32/libgcc_s.a
failed
/usr/bin/ldattempt to open /usr/bin/../lib/i386-linux-gnu/libgcc_s.so failed
: cannot find -lgcc
attempt to open /usr/bin/../lib/i386-linux-gnu/libgcc_s.a failed
attempt to open /usr/bin/../lib32/libgcc_s.so failed
attempt to open /usr/bin/../lib32/libgcc_s.a failed
attempt to open /lib/i386-linux-gnu/libgcc_s.so failed
attempt to open /lib/i386-linux-gnu/libgcc_s.a failed
attempt to open /lib/../lib32/libgcc_s.so failed
attempt to open /lib/../lib32/libgcc_s.a failed
attempt to open /usr/lib/i386-linux-gnu/libgcc_s.so failed
attempt to open /usr/lib/i386-linux-gnu/libgcc_s.a failed
attempt to open /usr/lib/../lib32/libgcc_s.so failed
attempt to open /usr/lib/../lib32/libgcc_s.a failed
attempt to open /usr/lib/x86_64-linux-gnu/../../lib32/libgcc_s.so failed
attempt to open /usr/lib/x86_64-linux-gnu/../../lib32/libgcc_s.a failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../libgcc_s.so failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../libgcc_s.a failed
attempt to open /usr/bin/../lib/libgcc_s.so failed
attempt to open /usr/bin/../lib/libgcc_s.a failed
attempt to open /lib/libgcc_s.so failed
attempt to open /lib/libgcc_s.a failed
attempt to open /usr/lib/libgcc_s.so failed
attempt to open /usr/lib/libgcc_s.a failed
attempt to open /usr/i386-linux-gnu/lib32/libgcc_s.so failed
attempt to open /usr/i386-linux-gnu/lib32/libgcc_s.a failed
attempt to open /usr/x86_64-linux-gnu/lib32/libgcc_s.so failed
attempt to open /usr/x86_64-linux-gnu/lib32/libgcc_s.a failed
attempt to open //usr/local/lib/i386-linux-gnu/libgcc_s.so failed
attempt to open //usr/local/lib/i386-linux-gnu/libgcc_s.a failed
attempt to open //usr/local/lib32/libgcc_s.so failed
attempt to open //usr/local/lib32/libgcc_s.a failed
attempt to open //lib/i386-linux-gnu/libgcc_s.so failed
attempt to open //lib/i386-linux-gnu/libgcc_s.a failed
attempt to open //lib32/libgcc_s.so failed
attempt to open //lib32/libgcc_s.a failed
attempt to open //usr/lib/i386-linux-gnu/libgcc_s.so failed
attempt to open //usr/lib/i386-linux-gnu/libgcc_s.a failed
attempt to open //usr/lib32/libgcc_s.so failed
attempt to open //usr/lib32/libgcc_s.a failed
attempt to open //usr/local/lib/libgcc_s.so failed
attempt to open //usr/local/lib/libgcc_s.a failed
attempt to open //lib/libgcc_s.so failed
attempt to open //lib/libgcc_s.a failed
attempt to open //usr/lib/libgcc_s.so failed
attempt to open //usr/lib/libgcc_s.a failed
attempt to open /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc.so failed
attempt to open /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/libgcc.a succeeded
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../i386-linux-gnu/libgcc.so
failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../i386-linux-gnu/libgcc.a
failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../lib32/libgcc.so
failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../lib32/libgcc.a
failed
attempt to open /usr/bin/../lib/i386-linux-gnu/libgcc.so failed
attempt to open /usr/bin/../lib/i386-linux-gnu/libgcc.a failed
attempt to open /usr/bin/../lib32/libgcc.so failed
attempt to open /usr/bin/../lib32/libgcc.a failed
attempt to open /lib/i386-linux-gnu/libgcc.so failed
attempt to open /lib/i386-linux-gnu/libgcc.a failed
attempt to open /lib/../lib32/libgcc.so failed
attempt to open /lib/../lib32/libgcc.a failed
attempt to open /usr/lib/i386-linux-gnu/libgcc.so failed
attempt to open /usr/lib/i386-linux-gnu/libgcc.a failed
attempt to open /usr/lib/../lib32/libgcc.so failed
attempt to open /usr/lib/../lib32/libgcc.a failed
attempt to open /usr/lib/x86_64-linux-gnu/../../lib32/libgcc.so failed
attempt to open /usr/lib/x86_64-linux-gnu/../../lib32/libgcc.a failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../libgcc.so failed
attempt to open
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../libgcc.a failed
attempt to open /usr/bin/../lib/libgcc.so failed
attempt to open /usr/bin/../lib/libgcc.a failed
attempt to open /lib/libgcc.so failed
attempt to open /lib/libgcc.a failed
attempt to open /usr/lib/libgcc.so failed
attempt to open /usr/lib/libgcc.a failed
attempt to open /usr/i386-linux-gnu/lib32/libgcc.so failed
attempt to open /usr/i386-linux-gnu/lib32/libgcc.a failed
attempt to open /usr/x86_64-linux-gnu/lib32/libgcc.so failed
attempt to open /usr/x86_64-linux-gnu/lib32/libgcc.a failed
attempt to open //usr/local/lib/i386-linux-gnu/libgcc.so failed
attempt to open //usr/local/lib/i386-linux-gnu/libgcc.a failed
attempt to open //usr/local/lib32/libgcc.so failed
attempt to open //usr/local/lib32/libgcc.a failed
attempt to open //lib/i386-linux-gnu/libgcc.so failed
attempt to open //lib/i386-linux-gnu/libgcc.a failed
attempt to open //lib32/libgcc.so failed
attempt to open //lib32/libgcc.a failed
attempt to open //usr/lib/i386-linux-gnu/libgcc.so failed
attempt to open //usr/lib/i386-linux-gnu/libgcc.a failed
attempt to open //usr/lib32/libgcc.so failed
attempt to open //usr/lib32/libgcc.a failed
attempt to open //usr/local/lib/libgcc.so failed
attempt to open //usr/local/lib/libgcc.a failed
attempt to open //lib/libgcc.so failed
attempt to open //lib/libgcc.a failed
attempt to open //usr/lib/libgcc.so failed
attempt to open //usr/lib/libgcc.a failed
clang: error: linker command failed with exit code 1 (use -v to see invocation)

On Wed, Jan 21, 2015 at 3:40 AM, Nils Gladitz <nilsgladitz at gmail.com> wrote:
> I am not sure what else it could be.
> Here are some queries I did on my system where it seems to be working;
> perhaps it will help you backtrack the issue:
>
> Ubuntu 14.04.1 LTS (64-bit)
>
> # gcc --version :
> gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2
>
> # clang --version :
> Ubuntu clang version 3.4-1ubuntu3 (tags/RELEASE_34/final) (based on LLVM
> 3.4)
>
> # clang++ -m32 -Wl,--verbose test.cpp|grep libgcc
> attempt to open /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/32/libgcc_s.so
> succeeded
> -lgcc_s (/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/32/libgcc_s.so)
>
> # file a.out
> a.out: ELF 32-bit LSB  executable, Intel 80386, version 1 (SYSV),
> dynamically linked (uses shared libs), for GNU/Linux 2.6.24,
> BuildID[sha1]=e15359bda06cce657369b3ae9d526c926deea6f2, not stripped
>
> # apt-file search /usr/lib/gcc/x86_64-linux-gnu/4.8/32/libgcc_s.so
> lib32gcc-4.8-dev: /usr/lib/gcc/x86_64-linux-gnu/4.8/32/libgcc_s.so
>
> g++-multilib has an indirect dependency on lib32gcc-4.8-dev.
>
> Nils