-# strtold.m4 serial 6
+# strtold.m4 serial 7
dnl Copyright (C) 2002-2003, 2006-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
if test $ac_cv_func_strtold != yes; then
HAVE_STRTOLD=0
else
- AC_CACHE_CHECK([whether strtold obeys C99], [gl_cv_func_strtold_works],
+ AC_CACHE_CHECK([whether strtold obeys POSIX], [gl_cv_func_strtold_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
#include <math.h>
char *term;
strtold (string, &term);
if (term != string && *(term - 1) == 0)
- result |= 2;
+ result |= 1;
}
{
/* Older glibc and Cygwin mis-parse "-0x". */
long double value = strtold (string, &term);
long double zero = 0.0L;
if (1.0L / value != -1.0L / zero || term != (string + 2))
- result |= 4;
+ result |= 2;
}
{
/* IRIX 6.5, mingw do not parse hex floats. */
char *term;
long double value = strtold (string, &term);
if (value != 20.0L || term != (string + 6))
- result |= 8;
+ result |= 4;
}
{
/* IRIX 6.5 does not parse infinities. HP-UX 11.31/ia64 parses inf,
errno = 0;
value = strtold (string, &term);
if (value != HUGE_VAL || term != (string + 3) || errno)
- result |= 16;
+ result |= 8;
}
{
/* glibc-2.3.2, IRIX 6.5, mingw, Haiku misparse "nan()". */
char *term;
long double value = strtold (string, &term);
if (numeric_equal (value, value) || term != (string + 5))
- result |= 32;
+ result |= 16;
}
{
/* Mac OS X 10.5, IRIX 6.5 misparse "nan(". */
char *term;
long double value = strtold (string, &term);
if (numeric_equal (value, value) || term != (string + 3))
+ result |= 32;
+ }
+ {
+ /* In Cygwin 2.9, strtold does not set errno upon underflow. */
+ const char *string = "1E-100000";
+ char *term;
+ long double value;
+ errno = 0;
+ value = strtold (string, &term);
+ if (term != (string + 9) || (value == 0.0L && errno != ERANGE))
result |= 64;
}
return result;
]])],
[gl_cv_func_strtold_works=yes],
- [gl_cv_func_strtold_works=no],
+ [if expr $? '>=' 64 >/dev/null; then
+ gl_cv_func_strtold_works="no (underflow problem)"
+ else
+ gl_cv_func_strtold_works=no
+ fi
+ ],
[dnl The last known bugs in glibc strtold(), as of this writing,
dnl were fixed in version 2.8
AC_EGREP_CPP([Lucky user],
[case "$host_os" in
# Guess yes on musl systems.
*-musl*) gl_cv_func_strtold_works="guessing yes" ;;
+ # Guess 'no (underflow problem)' on Cygwin.
+ cygwin*) gl_cv_func_strtold_works="guessing no (underflow problem)" ;;
*) gl_cv_func_strtold_works="$gl_cross_guess_normal" ;;
esac
])
*yes) ;;
*)
REPLACE_STRTOLD=1
+ case "$gl_cv_func_strtold_works" in
+ *"no (underflow problem)")
+ AC_DEFINE([STRTOLD_HAS_UNDERFLOW_BUG], [1],
+ [Define to 1 if strtold does not set errno upon underflow.])
+ ;;
+ esac
;;
esac
fi