[Distutils] How to specify the compiler

[Rene Liebscher]

see below for comments.

Michiel Jan Laurens de Hoon wrote:
> 
> I am trying to use distutils to install a Python extension module. The
> extension module needs gcc to compile. Unfortunately, on my unix system,
> distutils uses the standard C compiler cc instead of gcc, and the
> compilation fails. The gcc compiler is available on our system; however,
> I don't know how to tell distutils to use gcc instead of cc.
> 
> Some people on comp.lang.python have told me that distutils looks for
> the environment variable CC, and uses the corresponding compiler for the
> build process. However, I couldn't get this to work on my Unix system.
> Both set CC=gcc and setenv CC gcc didn't have any effect. Likewise,
> export CC=gcc is ignored on my Cygwin system.
> 
> In an effort to get to the bottom of this, I looked at the distutils
> source code. As far as I can tell, distutils calls customize_compiler,
> which calls get_config_vars, which calls _init_posix, which calls
> parse_makefile. This then finds the arguments supplied to
> get_config_vars from the python Makefile. Does anybody know where the
> checks for the environment variables are made? If no such checks are
> made, is this something that should be added to distutils? I am willing
> to spend some time on this to get this working.
> 
> Below I copied some output of my trials with distutils.
> 
> Thanks in advance,
> 
> --Michiel.
> University of Tokyo, Human Genome Center
> 
> blue{mdehoon}23: set CC=gcc
> blue{mdehoon}24: python setup.py build
> running build
> running build_py
> not copying Pycluster/__init__.py (output up-to-date)
> running build_ext
> building 'Pycluster.cluster' extension
> cc -DNDEBUG -O -OPT:Olimit=0 -Iranlib/src -I/usr/local/include/python2.2
> -c cluster.c -o build/temp.irix64-6.5-2.2/cluster.o
> 
> ... and so on
> 
> With setenv CC gcc, I get the same result:
> 
> blue{mdehoon}6: setenv CC gcc
> blue{mdehoon}7: python setup.py build
> running build
> running build_py
> not copying Pycluster/__init__.py (output up-to-date)
> running build_ext
> building 'Pycluster.cluster' extension
> cc -DNDEBUG -O -OPT:Olimit=0 -Iranlib/src -I/usr/local/include/python2.2
> -c clus
> ter.c -o build/temp.irix64-6.5-2.2/cluster.o
> ... and so on.
> 
Distuitls use always the compiler used for compilation of Python.
It reads it from the Python Makefile, if I remember right. 
And it get there also the compiler options.
So a possible solution would be create an script called cc, put in your
PATH
and try it this way.
This script has then to call your prefered compiler and possibly also
modify
the compiler options if necessary.


> I have tried export CC=bcc32 before on Cygwin, just to see what would
> happen, but that also got ignored by distutils:
> 
On Windows to use Borland's Compiler try 

python setup.py build --compiler=bcpp