[Python-Dev] Good way of finding out what C functions we have?

[Martin v. Löwis]

"Brett C." <bac at OCF.Berkeley.EDU> writes:

> Does there happen to be a better way to find out what functions we
> check for beyond grepping configure.in?  The entire reason I bothered
> to do so much research is I thought we were only supposed to assume
> ANSI C with POSIX (which, from what I can tell, strdup() is not).  

Actually, strdup is in POSIX:

http://www.opengroup.org/onlinepubs/007904975/functions/strdup.html

If we still check for it, it is because it might not have been
available on some system, at some point in time.

> Because of this I would like to list in the Python development guide I
> am writing up all of the places one can check for info; what
> configure.in checks for or handles and pyport.h come to mind.  It
> would be nice to have a place that lists all the places one can check
> for C functionality that are not in the Python/C API directly.  If
> people have other places in the code that one should check please let
> me know so I can make sure it makes it into the doc and prevents me
> from having to come up with another Brett Newbie Question.  =)

I would look in pyconfig.h.in as the first thing. There is a pitfall,
though: presence of some HAVE_foo in pyconfig.h does not mean that
Python gracefully deals with the absence of foo. When converting
configure to autoconf 2.5x, I checked all macros to determine whether
they were still in use, but some may have become unused/not processed
correctly since. That would be a bug, of course.

Regards,
Martin