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# strtod.m4
# serial 31
dnl Copyright (C) 2002-2003, 2006-2025 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 This file is offered as-is, without any warranty.
AC_DEFUN([gl_FUNC_STRTOD],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
m4_ifdef([gl_FUNC_STRTOD_OBSOLETE], [
dnl Test whether strtod is declared.
dnl Don't call AC_FUNC_STRTOD, because it does not have the right guess
dnl when cross-compiling.
dnl Don't call AC_CHECK_FUNCS([strtod]) because it would collide with the
dnl ac_cv_func_strtod variable set by the AC_FUNC_STRTOD macro.
AC_CHECK_DECLS_ONCE([strtod])
if test $ac_cv_have_decl_strtod != yes; then
HAVE_STRTOD=0
fi
])
if test $HAVE_STRTOD = 1; then
AC_CACHE_CHECK([whether strtod obeys C99], [gl_cv_func_strtod_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
#include <float.h>
#include <math.h>
#include <errno.h>
/* Compare two numbers with ==.
This is a separate function because IRIX 6.5 "cc -O" miscompiles an
'x == x' test. */
static int
numeric_equal (double x, double y)
{
return x == y;
}
]], [[
int result = 0;
{
/* In some old versions of Linux (2000 or before), strtod mis-parses
strings with leading '+'. */
const char *string = " +69";
char *term;
double value = strtod (string, &term);
if (value != 69 || term != (string + 4))
result |= 1;
}
{
/* Under Solaris 2.4, strtod returns the wrong value for the
terminating character under some conditions. */
const char *string = "NaN";
char *term;
strtod (string, &term);
if (term != string && *(term - 1) == 0)
result |= 1;
}
{
/* Older glibc and Cygwin mis-parse "-0x". */
const char *string = "-0x";
char *term;
double value = strtod (string, &term);
double zero = 0.0;
if (1.0 / value != -1.0 / zero || term != (string + 2))
result |= 2;
}
{
/* Many platforms do not parse hex floats. */
const char *string = "0XaP+1";
char *term;
double value = strtod (string, &term);
if (value != 20.0 || term != (string + 6))
result |= 4;
}
{
/* Many platforms do not parse infinities. HP-UX 11.31 parses inf,
but mistakenly sets errno. */
const char *string = "inf";
char *term;
double value;
errno = 0;
value = strtod (string, &term);
if (value != HUGE_VAL || term != (string + 3) || errno)
result |= 8;
}
{
/* glibc 2.7 and cygwin 1.5.24 misparse "nan()". */
const char *string = "nan()";
char *term;
double value = strtod (string, &term);
if (numeric_equal (value, value) || term != (string + 5))
result |= 16;
}
{
/* Darwin 10.6.1 (macOS 10.6.6) misparses "nan(". */
const char *string = "nan(";
char *term;
double value = strtod (string, &term);
if (numeric_equal (value, value) || term != (string + 3))
result |= 16;
}
#ifndef _MSC_VER /* On MSVC, this is expected behaviour. */
{
/* In Cygwin 2.9, strtod does not set errno upon
gradual underflow. */
const char *string = "1e-320";
char *term;
double value;
errno = 0;
value = strtod (string, &term);
if (term != (string + 6)
|| (value > 0.0 && value <= DBL_MIN && errno != ERANGE))
result |= 32;
}
#endif
{
/* strtod could not set errno upon
flush-to-zero underflow. */
const char *string = "1E-100000";
char *term;
double value;
errno = 0;
value = strtod (string, &term);
if (term != (string + 9) || (value == 0.0L && errno != ERANGE))
result |= 64;
}
return result;
]])],
[gl_cv_func_strtod_works=yes],
[result=$?
if expr $result '>=' 64 >/dev/null; then
gl_cv_func_strtod_works="no (underflow problem)"
else
if expr $result '>=' 32 >/dev/null; then
gl_cv_func_strtod_works="no (gradual underflow problem)"
else
gl_cv_func_strtod_works=no
fi
fi
],
[dnl The last known bugs in glibc strtod(), as of this writing,
dnl were fixed in version 2.8
AC_EGREP_CPP([Lucky user],
[
#include <features.h>
#ifdef __GNU_LIBRARY__
#if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 8) || (__GLIBC__ > 2)) \
&& !defined __UCLIBC__
Lucky user
#endif
#endif
],
[gl_cv_func_strtod_works="guessing yes"],
[case "$host_os" in
# Guess yes on musl systems.
*-musl* | midipix*) gl_cv_func_strtod_works="guessing yes" ;;
# Guess 'no (gradual underflow problem)' on Cygwin.
cygwin*) gl_cv_func_strtod_works="guessing no (gradual underflow problem)" ;;
# Guess yes on native Windows.
mingw* | windows*) gl_cv_func_strtod_works="guessing yes" ;;
*) gl_cv_func_strtod_works="$gl_cross_guess_normal" ;;
esac
])
])
])
case "$gl_cv_func_strtod_works" in
*yes) ;;
*)
REPLACE_STRTOD=1
case "$gl_cv_func_strtod_works" in
*"no (underflow problem)")
AC_DEFINE([STRTOD_HAS_UNDERFLOW_BUG], [1],
[Define to 1 if strtod does not set errno upon flush-to-zero underflow.])
;;
*"no (gradual underflow problem)")
AC_DEFINE([STRTOD_HAS_GRADUAL_UNDERFLOW_PROBLEM], [1],
[Define to 1 if strtod does not set errno upon gradual underflow.])
;;
esac
;;
esac
fi
])
# Prerequisites of lib/strtod.c.
AC_DEFUN([gl_PREREQ_STRTOD], [
AC_REQUIRE([gl_CHECK_LDEXP_NO_LIBM])
if test $gl_cv_func_ldexp_no_libm = yes; then
AC_DEFINE([HAVE_LDEXP_IN_LIBC], [1],
[Define if the ldexp function is available in libc.])
fi
gl_CHECK_FUNCS_ANDROID([nl_langinfo], [[#include <langinfo.h>]])
])
|
