blob: 4ac854d5198dc29009d728b5c08ba99947cdc87a [file] [log] [blame]
# stdint.m4 serial 50
dnl Copyright (C) 2001-2017 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 Paul Eggert and Bruno Haible.
dnl Test whether <stdint.h> is supported or must be substituted.
AC_DEFUN_ONCE([gl_STDINT_H],
[
AC_PREREQ([2.59])dnl
AC_REQUIRE([gl_LIMITS_H])
AC_REQUIRE([gt_TYPE_WINT_T])
dnl Check for long long int and unsigned long long int.
AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
if test $ac_cv_type_long_long_int = yes; then
HAVE_LONG_LONG_INT=1
else
HAVE_LONG_LONG_INT=0
fi
AC_SUBST([HAVE_LONG_LONG_INT])
AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
if test $ac_cv_type_unsigned_long_long_int = yes; then
HAVE_UNSIGNED_LONG_LONG_INT=1
else
HAVE_UNSIGNED_LONG_LONG_INT=0
fi
AC_SUBST([HAVE_UNSIGNED_LONG_LONG_INT])
dnl Check for <wchar.h>, in the same way as gl_WCHAR_H does.
AC_CHECK_HEADERS_ONCE([wchar.h])
if test $ac_cv_header_wchar_h = yes; then
HAVE_WCHAR_H=1
else
HAVE_WCHAR_H=0
fi
AC_SUBST([HAVE_WCHAR_H])
dnl Check for <inttypes.h>.
dnl AC_INCLUDES_DEFAULT defines $ac_cv_header_inttypes_h.
if test $ac_cv_header_inttypes_h = yes; then
HAVE_INTTYPES_H=1
else
HAVE_INTTYPES_H=0
fi
AC_SUBST([HAVE_INTTYPES_H])
dnl Check for <sys/types.h>.
dnl AC_INCLUDES_DEFAULT defines $ac_cv_header_sys_types_h.
if test $ac_cv_header_sys_types_h = yes; then
HAVE_SYS_TYPES_H=1
else
HAVE_SYS_TYPES_H=0
fi
AC_SUBST([HAVE_SYS_TYPES_H])
gl_CHECK_NEXT_HEADERS([stdint.h])
if test $ac_cv_header_stdint_h = yes; then
HAVE_STDINT_H=1
else
HAVE_STDINT_H=0
fi
AC_SUBST([HAVE_STDINT_H])
dnl Now see whether we need a substitute <stdint.h>.
if test $ac_cv_header_stdint_h = yes; then
AC_CACHE_CHECK([whether stdint.h conforms to C99],
[gl_cv_header_working_stdint_h],
[gl_cv_header_working_stdint_h=no
AC_COMPILE_IFELSE([
AC_LANG_PROGRAM([[
#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
#define __STDC_CONSTANT_MACROS 1
#define __STDC_LIMIT_MACROS 1
#include <stdint.h>
/* Dragonfly defines WCHAR_MIN, WCHAR_MAX only in <wchar.h>. */
#if !(defined WCHAR_MIN && defined WCHAR_MAX)
#error "WCHAR_MIN, WCHAR_MAX not defined in <stdint.h>"
#endif
]
gl_STDINT_INCLUDES
[
#ifdef INT8_MAX
int8_t a1 = INT8_MAX;
int8_t a1min = INT8_MIN;
#endif
#ifdef INT16_MAX
int16_t a2 = INT16_MAX;
int16_t a2min = INT16_MIN;
#endif
#ifdef INT32_MAX
int32_t a3 = INT32_MAX;
int32_t a3min = INT32_MIN;
#endif
#ifdef INT64_MAX
int64_t a4 = INT64_MAX;
int64_t a4min = INT64_MIN;
#endif
#ifdef UINT8_MAX
uint8_t b1 = UINT8_MAX;
#else
typedef int b1[(unsigned char) -1 != 255 ? 1 : -1];
#endif
#ifdef UINT16_MAX
uint16_t b2 = UINT16_MAX;
#endif
#ifdef UINT32_MAX
uint32_t b3 = UINT32_MAX;
#endif
#ifdef UINT64_MAX
uint64_t b4 = UINT64_MAX;
#endif
int_least8_t c1 = INT8_C (0x7f);
int_least8_t c1max = INT_LEAST8_MAX;
int_least8_t c1min = INT_LEAST8_MIN;
int_least16_t c2 = INT16_C (0x7fff);
int_least16_t c2max = INT_LEAST16_MAX;
int_least16_t c2min = INT_LEAST16_MIN;
int_least32_t c3 = INT32_C (0x7fffffff);
int_least32_t c3max = INT_LEAST32_MAX;
int_least32_t c3min = INT_LEAST32_MIN;
int_least64_t c4 = INT64_C (0x7fffffffffffffff);
int_least64_t c4max = INT_LEAST64_MAX;
int_least64_t c4min = INT_LEAST64_MIN;
uint_least8_t d1 = UINT8_C (0xff);
uint_least8_t d1max = UINT_LEAST8_MAX;
uint_least16_t d2 = UINT16_C (0xffff);
uint_least16_t d2max = UINT_LEAST16_MAX;
uint_least32_t d3 = UINT32_C (0xffffffff);
uint_least32_t d3max = UINT_LEAST32_MAX;
uint_least64_t d4 = UINT64_C (0xffffffffffffffff);
uint_least64_t d4max = UINT_LEAST64_MAX;
int_fast8_t e1 = INT_FAST8_MAX;
int_fast8_t e1min = INT_FAST8_MIN;
int_fast16_t e2 = INT_FAST16_MAX;
int_fast16_t e2min = INT_FAST16_MIN;
int_fast32_t e3 = INT_FAST32_MAX;
int_fast32_t e3min = INT_FAST32_MIN;
int_fast64_t e4 = INT_FAST64_MAX;
int_fast64_t e4min = INT_FAST64_MIN;
uint_fast8_t f1 = UINT_FAST8_MAX;
uint_fast16_t f2 = UINT_FAST16_MAX;
uint_fast32_t f3 = UINT_FAST32_MAX;
uint_fast64_t f4 = UINT_FAST64_MAX;
#ifdef INTPTR_MAX
intptr_t g = INTPTR_MAX;
intptr_t gmin = INTPTR_MIN;
#endif
#ifdef UINTPTR_MAX
uintptr_t h = UINTPTR_MAX;
#endif
intmax_t i = INTMAX_MAX;
uintmax_t j = UINTMAX_MAX;
/* Check that SIZE_MAX has the correct type, if possible. */
#if 201112 <= __STDC_VERSION__
int k = _Generic (SIZE_MAX, size_t: 0);
#elif (2 <= __GNUC__ || defined __IBM__TYPEOF__ \
|| (0x5110 <= __SUNPRO_C && !__STDC__))
extern size_t k;
extern __typeof__ (SIZE_MAX) k;
#endif
#include <limits.h> /* for CHAR_BIT */
#define TYPE_MINIMUM(t) \
((t) ((t) 0 < (t) -1 ? (t) 0 : ~ TYPE_MAXIMUM (t)))
#define TYPE_MAXIMUM(t) \
((t) ((t) 0 < (t) -1 \
? (t) -1 \
: ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
struct s {
int check_PTRDIFF:
PTRDIFF_MIN == TYPE_MINIMUM (ptrdiff_t)
&& PTRDIFF_MAX == TYPE_MAXIMUM (ptrdiff_t)
? 1 : -1;
/* Detect bug in FreeBSD 6.0 / ia64. */
int check_SIG_ATOMIC:
SIG_ATOMIC_MIN == TYPE_MINIMUM (sig_atomic_t)
&& SIG_ATOMIC_MAX == TYPE_MAXIMUM (sig_atomic_t)
? 1 : -1;
int check_SIZE: SIZE_MAX == TYPE_MAXIMUM (size_t) ? 1 : -1;
int check_WCHAR:
WCHAR_MIN == TYPE_MINIMUM (wchar_t)
&& WCHAR_MAX == TYPE_MAXIMUM (wchar_t)
? 1 : -1;
/* Detect bug in mingw. */
int check_WINT:
WINT_MIN == TYPE_MINIMUM (wint_t)
&& WINT_MAX == TYPE_MAXIMUM (wint_t)
? 1 : -1;
/* Detect bugs in glibc 2.4 and Solaris 10 stdint.h, among others. */
int check_UINT8_C:
(-1 < UINT8_C (0)) == (-1 < (uint_least8_t) 0) ? 1 : -1;
int check_UINT16_C:
(-1 < UINT16_C (0)) == (-1 < (uint_least16_t) 0) ? 1 : -1;
/* Detect bugs in OpenBSD 3.9 stdint.h. */
#ifdef UINT8_MAX
int check_uint8: (uint8_t) -1 == UINT8_MAX ? 1 : -1;
#endif
#ifdef UINT16_MAX
int check_uint16: (uint16_t) -1 == UINT16_MAX ? 1 : -1;
#endif
#ifdef UINT32_MAX
int check_uint32: (uint32_t) -1 == UINT32_MAX ? 1 : -1;
#endif
#ifdef UINT64_MAX
int check_uint64: (uint64_t) -1 == UINT64_MAX ? 1 : -1;
#endif
int check_uint_least8: (uint_least8_t) -1 == UINT_LEAST8_MAX ? 1 : -1;
int check_uint_least16: (uint_least16_t) -1 == UINT_LEAST16_MAX ? 1 : -1;
int check_uint_least32: (uint_least32_t) -1 == UINT_LEAST32_MAX ? 1 : -1;
int check_uint_least64: (uint_least64_t) -1 == UINT_LEAST64_MAX ? 1 : -1;
int check_uint_fast8: (uint_fast8_t) -1 == UINT_FAST8_MAX ? 1 : -1;
int check_uint_fast16: (uint_fast16_t) -1 == UINT_FAST16_MAX ? 1 : -1;
int check_uint_fast32: (uint_fast32_t) -1 == UINT_FAST32_MAX ? 1 : -1;
int check_uint_fast64: (uint_fast64_t) -1 == UINT_FAST64_MAX ? 1 : -1;
int check_uintptr: (uintptr_t) -1 == UINTPTR_MAX ? 1 : -1;
int check_uintmax: (uintmax_t) -1 == UINTMAX_MAX ? 1 : -1;
int check_size: (size_t) -1 == SIZE_MAX ? 1 : -1;
};
]])],
[dnl Determine whether the various *_MIN, *_MAX macros are usable
dnl in preprocessor expression. We could do it by compiling a test
dnl program for each of these macros. It is faster to run a program
dnl that inspects the macro expansion.
dnl This detects a bug on HP-UX 11.23/ia64.
AC_RUN_IFELSE([
AC_LANG_PROGRAM([[
#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
#define __STDC_CONSTANT_MACROS 1
#define __STDC_LIMIT_MACROS 1
#include <stdint.h>
]
gl_STDINT_INCLUDES
[
#include <stdio.h>
#include <string.h>
#define MVAL(macro) MVAL1(macro)
#define MVAL1(expression) #expression
static const char *macro_values[] =
{
#ifdef INT8_MAX
MVAL (INT8_MAX),
#endif
#ifdef INT16_MAX
MVAL (INT16_MAX),
#endif
#ifdef INT32_MAX
MVAL (INT32_MAX),
#endif
#ifdef INT64_MAX
MVAL (INT64_MAX),
#endif
#ifdef UINT8_MAX
MVAL (UINT8_MAX),
#endif
#ifdef UINT16_MAX
MVAL (UINT16_MAX),
#endif
#ifdef UINT32_MAX
MVAL (UINT32_MAX),
#endif
#ifdef UINT64_MAX
MVAL (UINT64_MAX),
#endif
NULL
};
]], [[
const char **mv;
for (mv = macro_values; *mv != NULL; mv++)
{
const char *value = *mv;
/* Test whether it looks like a cast expression. */
if (strncmp (value, "((unsigned int)"/*)*/, 15) == 0
|| strncmp (value, "((unsigned short)"/*)*/, 17) == 0
|| strncmp (value, "((unsigned char)"/*)*/, 16) == 0
|| strncmp (value, "((int)"/*)*/, 6) == 0
|| strncmp (value, "((signed short)"/*)*/, 15) == 0
|| strncmp (value, "((signed char)"/*)*/, 14) == 0)
return mv - macro_values + 1;
}
return 0;
]])],
[gl_cv_header_working_stdint_h=yes],
[],
[dnl When cross-compiling, assume it works.
gl_cv_header_working_stdint_h=yes
])
])
])
fi
HAVE_C99_STDINT_H=0
HAVE_SYS_BITYPES_H=0
HAVE_SYS_INTTYPES_H=0
STDINT_H=stdint.h
if test "$gl_cv_header_working_stdint_h" = yes; then
HAVE_C99_STDINT_H=1
dnl Now see whether the system <stdint.h> works without
dnl __STDC_CONSTANT_MACROS/__STDC_LIMIT_MACROS defined.
AC_CACHE_CHECK([whether stdint.h predates C++11],
[gl_cv_header_stdint_predates_cxx11_h],
[gl_cv_header_stdint_predates_cxx11_h=yes
AC_COMPILE_IFELSE([
AC_LANG_PROGRAM([[
#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
#include <stdint.h>
]
gl_STDINT_INCLUDES
[
intmax_t im = INTMAX_MAX;
int32_t i32 = INT32_C (0x7fffffff);
]])],
[gl_cv_header_stdint_predates_cxx11_h=no])])
if test "$gl_cv_header_stdint_predates_cxx11_h" = yes; then
AC_DEFINE([__STDC_CONSTANT_MACROS], [1],
[Define to 1 if the system <stdint.h> predates C++11.])
AC_DEFINE([__STDC_LIMIT_MACROS], [1],
[Define to 1 if the system <stdint.h> predates C++11.])
fi
AC_CACHE_CHECK([whether stdint.h has UINTMAX_WIDTH etc.],
[gl_cv_header_stdint_width],
[gl_cv_header_stdint_width=no
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[
/* Work if build is not clean. */
#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1
#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
#define __STDC_WANT_IEC_60559_BFP_EXT__ 1
#endif
#include <stdint.h>
]gl_STDINT_INCLUDES[
int iw = UINTMAX_WIDTH;
]])],
[gl_cv_header_stdint_width=yes])])
if test "$gl_cv_header_stdint_width" = yes; then
STDINT_H=
fi
else
dnl Check for <sys/inttypes.h>, and for
dnl <sys/bitypes.h> (used in Linux libc4 >= 4.6.7 and libc5).
AC_CHECK_HEADERS([sys/inttypes.h sys/bitypes.h])
if test $ac_cv_header_sys_inttypes_h = yes; then
HAVE_SYS_INTTYPES_H=1
fi
if test $ac_cv_header_sys_bitypes_h = yes; then
HAVE_SYS_BITYPES_H=1
fi
gl_STDINT_TYPE_PROPERTIES
fi
dnl The substitute stdint.h needs the substitute limit.h's _GL_INTEGER_WIDTH.
LIMITS_H=limits.h
AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
AC_SUBST([HAVE_C99_STDINT_H])
AC_SUBST([HAVE_SYS_BITYPES_H])
AC_SUBST([HAVE_SYS_INTTYPES_H])
AC_SUBST([STDINT_H])
AM_CONDITIONAL([GL_GENERATE_STDINT_H], [test -n "$STDINT_H"])
])
dnl gl_STDINT_BITSIZEOF(TYPES, INCLUDES)
dnl Determine the size of each of the given types in bits.
AC_DEFUN([gl_STDINT_BITSIZEOF],
[
dnl Use a shell loop, to avoid bloating configure, and
dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
dnl config.h.in,
dnl - extra AC_SUBST calls, so that the right substitutions are made.
m4_foreach_w([gltype], [$1],
[AH_TEMPLATE([BITSIZEOF_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]),
[Define to the number of bits in type ']gltype['.])])
for gltype in $1 ; do
AC_CACHE_CHECK([for bit size of $gltype], [gl_cv_bitsizeof_${gltype}],
[AC_COMPUTE_INT([result], [sizeof ($gltype) * CHAR_BIT],
[$2
#include <limits.h>], [result=unknown])
eval gl_cv_bitsizeof_${gltype}=\$result
])
eval result=\$gl_cv_bitsizeof_${gltype}
if test $result = unknown; then
dnl Use a nonempty default, because some compilers, such as IRIX 5 cc,
dnl do a syntax check even on unused #if conditions and give an error
dnl on valid C code like this:
dnl #if 0
dnl # if > 32
dnl # endif
dnl #endif
result=0
fi
GLTYPE=`echo "$gltype" | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
AC_DEFINE_UNQUOTED([BITSIZEOF_${GLTYPE}], [$result])
eval BITSIZEOF_${GLTYPE}=\$result
done
m4_foreach_w([gltype], [$1],
[AC_SUBST([BITSIZEOF_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]))])
])
dnl gl_CHECK_TYPES_SIGNED(TYPES, INCLUDES)
dnl Determine the signedness of each of the given types.
dnl Define HAVE_SIGNED_TYPE if type is signed.
AC_DEFUN([gl_CHECK_TYPES_SIGNED],
[
dnl Use a shell loop, to avoid bloating configure, and
dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
dnl config.h.in,
dnl - extra AC_SUBST calls, so that the right substitutions are made.
m4_foreach_w([gltype], [$1],
[AH_TEMPLATE([HAVE_SIGNED_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]),
[Define to 1 if ']gltype[' is a signed integer type.])])
for gltype in $1 ; do
AC_CACHE_CHECK([whether $gltype is signed], [gl_cv_type_${gltype}_signed],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([$2[
int verify[2 * (($gltype) -1 < ($gltype) 0) - 1];]])],
result=yes, result=no)
eval gl_cv_type_${gltype}_signed=\$result
])
eval result=\$gl_cv_type_${gltype}_signed
GLTYPE=`echo $gltype | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
if test "$result" = yes; then
AC_DEFINE_UNQUOTED([HAVE_SIGNED_${GLTYPE}], [1])
eval HAVE_SIGNED_${GLTYPE}=1
else
eval HAVE_SIGNED_${GLTYPE}=0
fi
done
m4_foreach_w([gltype], [$1],
[AC_SUBST([HAVE_SIGNED_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]))])
])
dnl gl_INTEGER_TYPE_SUFFIX(TYPES, INCLUDES)
dnl Determine the suffix to use for integer constants of the given types.
dnl Define t_SUFFIX for each such type.
AC_DEFUN([gl_INTEGER_TYPE_SUFFIX],
[
dnl Use a shell loop, to avoid bloating configure, and
dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
dnl config.h.in,
dnl - extra AC_SUBST calls, so that the right substitutions are made.
m4_foreach_w([gltype], [$1],
[AH_TEMPLATE(m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_])[_SUFFIX],
[Define to l, ll, u, ul, ull, etc., as suitable for
constants of type ']gltype['.])])
for gltype in $1 ; do
AC_CACHE_CHECK([for $gltype integer literal suffix],
[gl_cv_type_${gltype}_suffix],
[eval gl_cv_type_${gltype}_suffix=no
eval result=\$gl_cv_type_${gltype}_signed
if test "$result" = yes; then
glsufu=
else
glsufu=u
fi
for glsuf in "$glsufu" ${glsufu}l ${glsufu}ll ${glsufu}i64; do
case $glsuf in
'') gltype1='int';;
l) gltype1='long int';;
ll) gltype1='long long int';;
i64) gltype1='__int64';;
u) gltype1='unsigned int';;
ul) gltype1='unsigned long int';;
ull) gltype1='unsigned long long int';;
ui64)gltype1='unsigned __int64';;
esac
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([$2[
extern $gltype foo;
extern $gltype1 foo;]])],
[eval gl_cv_type_${gltype}_suffix=\$glsuf])
eval result=\$gl_cv_type_${gltype}_suffix
test "$result" != no && break
done])
GLTYPE=`echo $gltype | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
eval result=\$gl_cv_type_${gltype}_suffix
test "$result" = no && result=
eval ${GLTYPE}_SUFFIX=\$result
AC_DEFINE_UNQUOTED([${GLTYPE}_SUFFIX], [$result])
done
m4_foreach_w([gltype], [$1],
[AC_SUBST(m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_])[_SUFFIX])])
])
dnl gl_STDINT_INCLUDES
AC_DEFUN([gl_STDINT_INCLUDES],
[[
/* BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
included before <wchar.h>. */
#include <stddef.h>
#include <signal.h>
#if HAVE_WCHAR_H
# include <stdio.h>
# include <time.h>
# include <wchar.h>
#endif
]])
dnl gl_STDINT_TYPE_PROPERTIES
dnl Compute HAVE_SIGNED_t, BITSIZEOF_t and t_SUFFIX, for all the types t
dnl of interest to stdint.in.h.
AC_DEFUN([gl_STDINT_TYPE_PROPERTIES],
[
AC_REQUIRE([gl_MULTIARCH])
if test $APPLE_UNIVERSAL_BUILD = 0; then
gl_STDINT_BITSIZEOF([ptrdiff_t size_t],
[gl_STDINT_INCLUDES])
fi
gl_STDINT_BITSIZEOF([sig_atomic_t wchar_t wint_t],
[gl_STDINT_INCLUDES])
gl_CHECK_TYPES_SIGNED([sig_atomic_t wchar_t wint_t],
[gl_STDINT_INCLUDES])
gl_cv_type_ptrdiff_t_signed=yes
gl_cv_type_size_t_signed=no
if test $APPLE_UNIVERSAL_BUILD = 0; then
gl_INTEGER_TYPE_SUFFIX([ptrdiff_t size_t],
[gl_STDINT_INCLUDES])
fi
gl_INTEGER_TYPE_SUFFIX([sig_atomic_t wchar_t wint_t],
[gl_STDINT_INCLUDES])
dnl If wint_t is smaller than 'int', it cannot satisfy the ISO C 99
dnl requirement that wint_t is "unchanged by default argument promotions".
dnl In this case gnulib's <wchar.h> and <wctype.h> override wint_t.
dnl Set the variable BITSIZEOF_WINT_T accordingly.
if test $GNULIB_OVERRIDES_WINT_T = 1; then
BITSIZEOF_WINT_T=32
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])])
])