3 dnl Copyright (C) 2002-2003, 2006-2024 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
8 AC_DEFUN([gl_FUNC_STRTOLD],
10 AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
11 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
12 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
13 AC_CHECK_FUNCS_ONCE([strtold])
14 if test $ac_cv_func_strtold != yes; then
17 AC_CACHE_CHECK([whether strtold obeys POSIX], [gl_cv_func_strtold_works],
18 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
22 /* Compare two numbers with ==.
23 This is a separate function because IRIX 6.5 "cc -O" miscompiles an
26 numeric_equal (long double x, long double y)
33 /* Under Solaris 2.4, strtod returns the wrong value for the
34 terminating character under some conditions. */
35 const char *string = "NaN";
37 strtold (string, &term);
38 if (term != string && *(term - 1) == 0)
42 /* Older glibc and Cygwin mis-parse "-0x". */
43 const char *string = "-0x";
45 long double value = strtold (string, &term);
46 long double zero = 0.0L;
47 if (1.0L / value != -1.0L / zero || term != (string + 2))
51 /* IRIX 6.5, mingw do not parse hex floats. */
52 const char *string = "0XaP+1";
54 long double value = strtold (string, &term);
55 if (value != 20.0L || term != (string + 6))
59 /* IRIX 6.5 does not parse infinities. HP-UX 11.31/ia64 parses inf,
60 but mistakenly sets errno. */
61 const char *string = "inf";
65 value = strtold (string, &term);
66 if (value != HUGE_VAL || term != (string + 3) || errno)
70 /* glibc-2.3.2, IRIX 6.5, mingw, Haiku misparse "nan()". */
71 const char *string = "nan()";
73 long double value = strtold (string, &term);
74 if (numeric_equal (value, value) || term != (string + 5))
78 /* Mac OS X 10.5, IRIX 6.5 misparse "nan(". */
79 const char *string = "nan(";
81 long double value = strtold (string, &term);
82 if (numeric_equal (value, value) || term != (string + 3))
86 /* In Cygwin 2.9, strtold does not set errno upon underflow. */
87 const char *string = "1E-100000";
91 value = strtold (string, &term);
92 if (term != (string + 9) || (value == 0.0L && errno != ERANGE))
97 [gl_cv_func_strtold_works=yes],
98 [if expr $? '>=' 64 >/dev/null; then
99 gl_cv_func_strtold_works="no (underflow problem)"
101 gl_cv_func_strtold_works=no
104 [dnl The last known bugs in glibc strtold(), as of this writing,
105 dnl were fixed in version 2.8
106 AC_EGREP_CPP([Lucky user],
108 #include <features.h>
109 #ifdef __GNU_LIBRARY__
110 #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 8) || (__GLIBC__ > 2)) \
111 && !defined __UCLIBC__
116 [gl_cv_func_strtold_works="guessing yes"],
118 # Guess yes on musl systems.
119 *-musl* | midipix*) gl_cv_func_strtold_works="guessing yes" ;;
120 # Guess 'no (underflow problem)' on Cygwin.
121 cygwin*) gl_cv_func_strtold_works="guessing no (underflow problem)" ;;
122 *) gl_cv_func_strtold_works="$gl_cross_guess_normal" ;;
127 case "$gl_cv_func_strtold_works" in
131 case "$gl_cv_func_strtold_works" in
132 *"no (underflow problem)")
133 AC_DEFINE([STRTOLD_HAS_UNDERFLOW_BUG], [1],
134 [Define to 1 if strtold does not set errno upon underflow.])
142 # Prerequisites of lib/strtold.c.
143 AC_DEFUN([gl_PREREQ_STRTOLD], [
144 AC_REQUIRE([gl_CHECK_LDEXPL_NO_LIBM])
145 if test $gl_cv_func_ldexpl_no_libm = yes; then
146 AC_DEFINE([HAVE_LDEXPL_IN_LIBC], [1],
147 [Define if the ldexpl function is available in libc.])
149 gl_CHECK_FUNCS_ANDROID([nl_langinfo], [[#include <langinfo.h>]])