support cross compiling

[mtp401]

This patch adds support for cross compiling nnpy (e.g. under Buildroot). I modeled the changes after what numpy seemingly does (using a site.cfg file if one is present).

[djc]

Thanks for the patch! I'll try to review it ASAP, probably tomorrow.

From a quick skim, first feedback will be that I don't like that you're sort of randomly rewriting whitespace in parts of the code that you don't otherwise touch. Second, there's a bit too much going on in the global scope, this should go into a function somehow. However, feel free to hold off doing something about this until I can do a more complete review.

[djc]

The approach looks basically sane, but like I said, there's way too much code in the global scope. Just move all of the reading of the config file into create_module() instead. Except the imports, which should just go near the other imports at the top.

The setting of variables seems to be a bit roundabout (set constant to None, then set it from the site config, then set it to the default value if still None). Instead, you could just have the constants with the default values, then overwrite them if specified in the site-specific config. Instead of overwriting the constant values, pass around the local variables (so include_dirs to header_files(), and host_library to symbols()) as needed.

As mentioned before, please leave whitespace intact in places you're not touching (alternatively, if you really dislike trailing whitespace, create a separate commit that cleans up trailing whitespace before you commit your actual changes).

Thanks again, nice to get this in!

[mtp401]

Hi @djc, please take another look when you get a chance. I've made the changes you suggested and split off the whitespace changes into their own commit.

[djc]

Looks great, thanks!

[djc]

FWIW, I've also put a 1.2 release incorporating your changes on PyPI.

[mtp401]

Great thanks!