`checking size of mp_limb_t... 0` and `configure: error: Oops, mp_limb_t doesn't seem to work` when compiling the Microchip XC32 compiler from source

[Marc Glisse]

On Tue, 7 Nov 2023, Niels Möller wrote:

> (2) It makes no sense for any C code, in conftest.c or otherwise, to
>    ever attempt to include gmp-h.in. That's not a valid C header file,
>    since it lacks the substitutions that turns it into a valid gmp.h
>    header file.

>From acinclude.m4:


dnl  GMP_INCLUDE_GMP_H
dnl  -----------------
dnl  Expand to the right way to #include gmp-h.in.  This must be used
dnl  instead of gmp.h, since that file isn't generated until the end of 
the
dnl  configure.
dnl
dnl  Dummy value for GMP_LIMB_BITS is enough
dnl  for all current configure-time uses of gmp.h.

define(GMP_INCLUDE_GMP_H,
[[#define __GMP_WITHIN_CONFIGURE 1   /* ignore template stuff */
#define GMP_NAIL_BITS $GMP_NAIL_BITS
#define GMP_LIMB_BITS 123
$DEFN_LONG_LONG_LIMB
#include "$srcdir/gmp-h.in"]
])


-- 
Marc Glisse