Building 32-bit apps on x86_64 system

[paulsen]

I need to build a 32-bit version of an app (dbxml) on my Kubuntu x86_64 system. This will be run on an IA32 system, not on the X86_64.

dbxml attempts to build 32-bits when given the right environment variables but fails with the following messages:

configure:4143: gcc -m32 -D_GNU_SOURCE -D_REENTRANT conftest.c >&5
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.1/libgcc.a when searching for -lgcc
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.1/libgcc.a when searching for -lgcc
/usr/bin/ld: cannot find -lgcc

Being new to (K)Ububtu, I am not sure how to get the right libs. I looked in System Settings -> Add and Remove Software but there is no 32-bit version of the libs listed.

Bob

[jetdrone]

Re: Building 32-bit apps on x86_64 system

you should install the multilib libs

sudo apt-get install gcc-multilib g++-multilib

and the same for fortran and objc if you want those compilers too.

Then to compile to 32bit from a 64bit machine just run

gcc -m32 -c source.c -o source.o
ld -m32 objects.o final_binary

A short cut would be to do:

CC="gcc -m32" CXX="g++ -m32" LD="gcc -m32" make

This makes sure you compile with 32bit support