[ovs-dev] [PATCH] python/setup: "-fPIC" extra compile flag for C extension

[Ben Pfaff]

On Wed, Jan 11, 2017 at 09:38:13AM +0900, IWASE Yusuke wrote:
> To build shared library object, it is required to built as "Position
> Independent Code" (on x86-64, for example).
> This patch adds "-fPIC" extra compile flag to make sure that extension
> being PIC while building a shared library object.
> 
> Signed-off-by: IWASE Yusuke <iwase.yusuke0 at gmail.com>
> ---
>  python/setup.py | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/python/setup.py b/python/setup.py
> index 19c1f18..8f565d8 100644
> --- a/python/setup.py
> +++ b/python/setup.py
> @@ -76,8 +76,13 @@ setup_args = dict(
>          'Programming Language :: Python :: 3',
>          'Programming Language :: Python :: 3.4',
>      ],
> -    ext_modules=[setuptools.Extension("ovs._json", sources=["ovs/_json.c"],
> -                                      libraries=['openvswitch'])],
> +    ext_modules=[
> +        setuptools.Extension(
> +            "ovs._json",
> +            sources=["ovs/_json.c"],
> +            libraries=['openvswitch'],
> +            extra_compile_args=["-fPIC"]),
> +        ],
>      cmdclass={'build_ext': try_build_ext},
>  )

Are you sure that this is the right way to build a Python shared object?
It is very ELF-specific so I imagine that it will break Windows and BSD
builds.