xmms/gentoo-m4/size_max.m4

# size_max.m4 serial 2
dnl Copyright (C) 2003 Free Software Foundation, Inc.
dnl This file is free software, distributed under the terms of the GNU
dnl General Public License.  As a special exception to the GNU General
dnl Public License, this file may be distributed as part of a program
dnl that contains a configuration script generated by Autoconf, under
dnl the same distribution terms as the rest of that program.

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])
  result=
  AC_EGREP_CPP([Found it], [
#include <limits.h>
#if HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef SIZE_MAX
Found it
#endif
], result=yes)
  if test -z "$result"; then
    dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
    dnl than the type 'unsigned long'.
    dnl The _AC_COMPUTE_INT macro works up to LONG_MAX, since it uses 'expr',
    dnl which is guaranteed to work from LONG_MIN to LONG_MAX.
    _AC_COMPUTE_INT([~(size_t)0 / 10], res_hi,
      [#include <stddef.h>], result=?)
    _AC_COMPUTE_INT([~(size_t)0 % 10], res_lo,
      [#include <stddef.h>], result=?)
    _AC_COMPUTE_INT([sizeof (size_t) <= sizeof (unsigned int)], fits_in_uint,
      [#include <stddef.h>], result=?)
    if test "$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
    if test -z "$result"; then
      if test "$fits_in_uint" = 1; then
        result="$res_hi$res_lo"U
      else
        result="$res_hi$res_lo"UL
      fi
    else
      dnl Shouldn't happen, but who knows...
      result='~(size_t)0'
    fi
  fi
  AC_MSG_RESULT([$result])
  if test "$result" != yes; then
    AC_DEFINE_UNQUOTED([SIZE_MAX], [$result],
      [Define as the maximum value of type 'size_t', if the system doesn't define it.])
  fi
])
1	niro	153	# size_max.m4 serial 2
2			dnl Copyright (C) 2003 Free Software Foundation, Inc.
3			dnl This file is free software, distributed under the terms of the GNU
4			dnl General Public License. As a special exception to the GNU General
5			dnl Public License, this file may be distributed as part of a program
6			dnl that contains a configuration script generated by Autoconf, under
7			dnl the same distribution terms as the rest of that program.
8
9			dnl From Bruno Haible.
10
11			AC_DEFUN([gl_SIZE_MAX],
12			[
13			AC_CHECK_HEADERS(stdint.h)
14			dnl First test whether the system already has SIZE_MAX.
15			AC_MSG_CHECKING([for SIZE_MAX])
16			result=
17			AC_EGREP_CPP([Found it], [
18			#include <limits.h>
19			#if HAVE_STDINT_H
20			#include <stdint.h>
21			#endif
22			#ifdef SIZE_MAX
23			Found it
24			#endif
25			], result=yes)
26			if test -z "$result"; then
27			dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
28			dnl than the type 'unsigned long'.
29			dnl The _AC_COMPUTE_INT macro works up to LONG_MAX, since it uses 'expr',
30			dnl which is guaranteed to work from LONG_MIN to LONG_MAX.
31			_AC_COMPUTE_INT([~(size_t)0 / 10], res_hi,
32			[#include <stddef.h>], result=?)
33			_AC_COMPUTE_INT([~(size_t)0 % 10], res_lo,
34			[#include <stddef.h>], result=?)
35			_AC_COMPUTE_INT([sizeof (size_t) <= sizeof (unsigned int)], fits_in_uint,
36			[#include <stddef.h>], result=?)
37			if test "$fits_in_uint" = 1; then
38			dnl Even though SIZE_MAX fits in an unsigned int, it must be of type
39			dnl 'unsigned long' if the type 'size_t' is the same as 'unsigned long'.
40			AC_TRY_COMPILE([#include <stddef.h>
41			extern size_t foo;
42			extern unsigned long foo;
43			], [], fits_in_uint=0)
44			fi
45			if test -z "$result"; then
46			if test "$fits_in_uint" = 1; then
47			result="$res_hi$res_lo"U
48			else
49			result="$res_hi$res_lo"UL
50			fi
51			else
52			dnl Shouldn't happen, but who knows...
53			result='~(size_t)0'
54			fi
55			fi
56			AC_MSG_RESULT([$result])
57			if test "$result" != yes; then
58			AC_DEFINE_UNQUOTED([SIZE_MAX], [$result],
59			[Define as the maximum value of type 'size_t', if the system doesn't define it.])
60			fi
61			])