How to add c compiler options to distutils

I want to call Mathematica from C code and C code from Python. I have the individual parts working, but I can't put everything together.

When I compile the C code that calls Mathematica, then I use the following command in makefile

$(CC) -O mlcall.c -I$(INCDIR) -L$(LIBDIR) -l${MLLIB} ${EXTRALIBS} -o $@

Where

MLINKDIR = /opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit
SYS=Linux-x86-64
CADDSDIR = ${MLINKDIR}/${SYS}/CompilerAdditions
INCDIR = ${CADDSDIR}
LIBDIR = ${CADDSDIR}
MLLIB = ML64i3

My question is how can I use distutils with those same options (currently I'm getting undefined symbol: MLActivate error, when calling from Python and I think the problem is because I'm not using these options)?

I saw the answer https://stackoverflow.com/a/16078447/1335014 and tried to use CFLAGS (by running the following script):

MLINKDIR=/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit
SYS="Linux-x86-64"
CADDSDIR=${MLINKDIR}/${SYS}/CompilerAdditions
INCDIR=${CADDSDIR}
LIBDIR=${CADDSDIR}
MLLIB=ML64i3
EXTRALIBS="-lm -lpthread -lrt -lstdc++"
export CFLAGS="-I$INCDIR -L$LIBDIR -l${MLLIB} ${EXTRALIBS}"

So I get the following output for echo $CFLAGS

-I/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions -L/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions -lML64i3 -lm -lpthread -lrt -lstdc++

Which seems correct, but didn't have any effect. Maybe because I'm adding more than one option.

Solution

I realized that if you don't modify the C source code then nothing is compiled (the original error I had stayed because of that reason). Using CFLAGS, as I did, actually does fix the problem.

After digging around in distutils documentations I found two additional fixes (these only use setup.py and don't require any environment variables).

from distutils.core import setup, Extension

module1 = Extension('spammodule',
                sources = ['spammodule.c'],
                extra_compile_args=["-I/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions"],
                extra_link_args=["-L/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions", "-lML64i3", "-lm", "-lpthread", "-lrt", "-lstdc++"])

setup (name = 'MyPackage',
                version = '1.0',
                description = 'This is a demo package',
                ext_modules = [module1])

from distutils.core import setup, Extension

module1 = Extension('spammodule',
            sources = ['spammodule.c'],
            include_dirs=['/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions'],
            library_dirs=['/opt/Mathematica-9.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions'],
            libraries=["ML64i3", "m", "pthread", "rt", "stdc++"])

setup (name = 'MyPackage',
            version = '1.0',
            description = 'This is a demo package',
            ext_modules = [module1])