[Cython] getting rid of C' stlib strcmp() in generated sources

[Stefan Behnel]

Lisandro Dalcin wrote:
> I'm thinking on removing dependencies on the C stdlib...
> [...]
> As strcmp() is trivial to implement

Is it really? It does sound trivial, but I would assume that many platforms
have highly optimised implementations for it. At least, I know that libxml2
uses memcmp on some platforms and strcmp on others, depending on what's
known to be faster. I wouldn't want to copy this kind of code into Cython,
just to work around one broken platform.

Honestly, how broken must a platform be to not support strcmp()?


> Cython uses it in just a few
> places, and mainly for work around some deficiencies in the Python
> C-API, then I what to remove this dependency from Cython generated
> code.

I have no idea where that's currently used and if those places are in any
way performance critical, so I can't comment without looking into this. I
might even have added a couple of those myself.


> IMHO, it is a really good idea to avoid any link-time dependencies in
> the generated codes... right now, I'm even moved in my own code from
> using malloc()/free() to use PyMem_Malloc()/PyMem_Free()...

That by itself is perfectly ok and makes sense (although I don't know if
you can use PyMem_*() in nogil functions/blocks).

Stefan