vlc/m4/size_max.m4
Rémi Denis-Courmont 7bbc2548f9 Switch to gettext 0.17
The whole point of keeping the m4 and po/Makefile.in.in is to not need
to have the same version all over the place anyway, otherwise we might
as well put all these files to .gitignore...

Remove some old m4 macros as well.
2008-03-23 22:01:24 +02:00

69 lines
2.6 KiB
Plaintext

# size_max.m4 serial 6
dnl Copyright (C) 2003, 2005-2006 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl From Bruno Haible.
AC_DEFUN([gl_SIZE_MAX],
[
AC_CHECK_HEADERS(stdint.h)
dnl First test whether the system already has SIZE_MAX.
AC_MSG_CHECKING([for SIZE_MAX])
AC_CACHE_VAL([gl_cv_size_max], [
gl_cv_size_max=
AC_EGREP_CPP([Found it], [
#include <limits.h>
#if HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef SIZE_MAX
Found it
#endif
], gl_cv_size_max=yes)
if test -z "$gl_cv_size_max"; then
dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
dnl than the type 'unsigned long'. Try hard to find a definition that can
dnl be used in a preprocessor #if, i.e. doesn't contain a cast.
AC_COMPUTE_INT([size_t_bits_minus_1], [sizeof (size_t) * CHAR_BIT - 1],
[#include <stddef.h>
#include <limits.h>], size_t_bits_minus_1=)
AC_COMPUTE_INT([fits_in_uint], [sizeof (size_t) <= sizeof (unsigned int)],
[#include <stddef.h>], fits_in_uint=)
if test -n "$size_t_bits_minus_1" && test -n "$fits_in_uint"; then
if test $fits_in_uint = 1; then
dnl Even though SIZE_MAX fits in an unsigned int, it must be of type
dnl 'unsigned long' if the type 'size_t' is the same as 'unsigned long'.
AC_TRY_COMPILE([#include <stddef.h>
extern size_t foo;
extern unsigned long foo;
], [], fits_in_uint=0)
fi
dnl We cannot use 'expr' to simplify this expression, because 'expr'
dnl works only with 'long' integers in the host environment, while we
dnl might be cross-compiling from a 32-bit platform to a 64-bit platform.
if test $fits_in_uint = 1; then
gl_cv_size_max="(((1U << $size_t_bits_minus_1) - 1) * 2 + 1)"
else
gl_cv_size_max="(((1UL << $size_t_bits_minus_1) - 1) * 2 + 1)"
fi
else
dnl Shouldn't happen, but who knows...
gl_cv_size_max='((size_t)~(size_t)0)'
fi
fi
])
AC_MSG_RESULT([$gl_cv_size_max])
if test "$gl_cv_size_max" != yes; then
AC_DEFINE_UNQUOTED([SIZE_MAX], [$gl_cv_size_max],
[Define as the maximum value of type 'size_t', if the system doesn't define it.])
fi
])
dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
dnl Remove this when we can assume autoconf >= 2.61.
m4_ifdef([AC_COMPUTE_INT], [], [
AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
])