ale/m4/strtod.m4
2022-07-30 14:46:04 -03:00

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# strtod.m4 serial 9
dnl Copyright (C) 2002, 2003, 2006, 2007, 2008 Free Software
dnl 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.
AC_DEFUN([gl_FUNC_STRTOD],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
AC_FUNC_STRTOD
dnl Note: AC_FUNC_STRTOD does AC_LIBOBJ(strtod).
if test $ac_cv_func_strtod = no; then
HAVE_STRTOD=0
REPLACE_STRTOD=1
gl_PREREQ_STRTOD
else
AC_CACHE_CHECK([whether strtod obeys C99], [gl_cv_func_strtod_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
#include <math.h>
/* Compare two numbers with ==.
This is a separate function because IRIX 6.5 "cc -O" miscompiles an
'x == x' test. */
static int
numeric_equal (double x, double y)
{
return x == y;
}
]], [[
{
/* Older glibc and Cygwin mis-parse "-0x". */
const char *string = "-0x";
char *term;
double value = strtod (string, &term);
double zero = 0.0;
if (1.0 / value != -1.0 / zero || term != (string + 2))
return 1;
}
{
/* Many platforms do not parse hex floats. */
const char *string = "0XaP+1";
char *term;
double value = strtod (string, &term);
if (value != 20.0 || term != (string + 6))
return 1;
}
{
/* Many platforms do not parse infinities. */
const char *string = "inf";
char *term;
double value = strtod (string, &term);
if (value != HUGE_VAL || term != (string + 3))
return 1;
}
{
/* glibc 2.7 and cygwin 1.5.24 misparse "nan()". */
const char *string = "nan()";
char *term;
double value = strtod (string, &term);
if (numeric_equal (value, value) || term != (string + 5))
return 1;
}
]])],
[gl_cv_func_strtod_works=yes],
[gl_cv_func_strtod_works=no],
[gl_cv_func_strtod_works="guessing no"])])
if test "$gl_cv_func_strtod_works" != yes; then
REPLACE_STRTOD=1
gl_PREREQ_STRTOD
dnl Use undocumented macro to set POW_LIB correctly.
_AC_LIBOBJ_STRTOD
fi
fi
])
# Prerequisites of lib/strtod.c.
# The need for pow() is already handled by AC_FUNC_STRTOD.
AC_DEFUN([gl_PREREQ_STRTOD], [:])