[OE-core] [PATCHv2] python: Unbreak Python third-party extensions

[Richard Purdie]

On Tue, 2011-05-03 at 18:40 +0200, Michael Lippautz wrote:
> This patch fixes compilation/linking of python third-party extensions, i.e.
> Extensions that ship with C code.
> 
> Problem:
> Python uses distutils(-native) to compile third-party extensions. distutils
> uses its own sysconfig module to get the options for compiling and linking.
> Since third-party extensions have to be linked against this libpython it
> important that -L points into staging. This is not the case because
> distutils.sysconfig uses a special Makefile that is shipped with python
> determine the paths. The Makefile is the same that would be used on the
> target to build third-party extensions. It therefore points into /usr/lib
> instead of staging.
> 
> Solution:
> Stage a modified version of the Makefile where the paths (incdir, libdir) have
> been replaced by ones that point into staging.
> 
> Side-problem:
> The recipe actually should not stage files itself in do_compile, but rather
> handle everything that needs to be staged in do_install. This is currently not
> possible because python compiles itself using distutils-native. Distutils on
> the other hand does only allow to add a path, but not to substitute it,
> requiring a staged Makefile and libpython.so before the actual python
> compilation is triggered.
> 
> The second step to solve this would be to either patch distutils, or split
> python into python-initial and python. The -initial part could create the
> Makefile and the library, while the main part focuses on the target.
> 
> For further references see:
>  http://lists.linuxtogo.org/pipermail/openembedded-core/2011-May/001752.html
> 
> Signed-off-by: Michael Lippautz <michael.lippautz at gmail.com>
> Acked-by: Martin Jansa <Martin.Jansa at gmail.com>
> ---
>  meta/recipes-devtools/python/python_2.6.6.bb |   41 +++++++++++++++++---------
>  1 files changed, 27 insertions(+), 14 deletions(-)

Merged to master, thanks.

Richard