Re: autoconf 2.5, 2.13, and Vim

[Akim Demaille]

>>>>> "Paul" == Paul Eggert <address@hidden> writes:

>>  Or should we simply state that #undef HAVE_INTTYPES_H when both
>> cannot be included together?

Paul> That sounds like a reasonable simplification to me.

Yep, and in the long run, that's where I want to go (with autosystem
and so on, we should no longer just check confdefs.h, but

#include confdefs.h
#include system.h

so that configure tests what the application will actually use.).

There is something I wish we had done long ago, and now I fear it is
too incompatible a change, but I'd like AC_CHECK_HEADERS to have an
argument for includes, and the same default includes as the other
macros.  _Then_ we actually check whether the header is usable, not if
it merely exists.

Paul> One compatibility point, though.  Currently, autoconf assumes
Paul> that <sys/types.h> exists, but this assumption is valid only for
Paul> POSIX-related items, as <sys/types.h> is required only by POSIX,
Paul> not by the C Standard.

That's the first time ever someone suggest to check for it!

So, are you actually saying that *any* #include <foo.h> should be
checked?  Instead of having acheaders list plenty of headers,
shouldn't it just list all the headers that have specific macros, and
then, autoscan would ask for checking all the others?

Hm, there remains the case of headers coming with a lib, and we only
want to check for a single one of them (e.g., I guess there are
zillions of X11 headers, but we don't check for them all).


Paul> While you're at it you should wrap '#include <sys/types.h>'
Paul> inside '#if HAVE_SYS_TYPES_H' in all other macros that ought to
Paul> work even on non-POSIX platforms.

OK, I'll do that.

Paul, what of sys/stat.h too.  Lemme guess: likewise :)