blob: 460ddc9571b589f33811a74dfb43d54ae8c8860b [file] [log] [blame]
# strerror.m4 serial 17
dnl Copyright (C) 2002, 2007-2017 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.
AC_DEFUN([gl_FUNC_STRERROR],
[
AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
AC_REQUIRE([gl_HEADER_ERRNO_H])
AC_REQUIRE([gl_FUNC_STRERROR_0])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
])
if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
AC_CACHE_CHECK([for working strerror function],
[gl_cv_func_working_strerror],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[#include <string.h>
]],
[[if (!*strerror (-2)) return 1;]])],
[gl_cv_func_working_strerror=yes],
[gl_cv_func_working_strerror=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_working_strerror="guessing yes" ;;
# If we don't know, assume the worst.
*) gl_cv_func_working_strerror="guessing no" ;;
esac
])
])
case "$gl_cv_func_working_strerror" in
*yes) ;;
*)
dnl The system's strerror() fails to return a string for out-of-range
dnl integers. Replace it.
REPLACE_STRERROR=1
;;
esac
m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
dnl If the system's strerror_r or __xpg_strerror_r clobbers strerror's
dnl buffer, we must replace strerror.
case "$gl_cv_func_strerror_r_works" in
*no) REPLACE_STRERROR=1 ;;
esac
])
else
dnl The system's strerror() cannot know about the new errno values we add
dnl to <errno.h>, or any fix for strerror(0). Replace it.
REPLACE_STRERROR=1
fi
])
dnl Detect if strerror(0) passes (that is, does not set errno, and does not
dnl return a string that matches strerror(-1)).
AC_DEFUN([gl_FUNC_STRERROR_0],
[
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
REPLACE_STRERROR_0=0
AC_CACHE_CHECK([whether strerror(0) succeeds],
[gl_cv_func_strerror_0_works],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[#include <string.h>
#include <errno.h>
]],
[[int result = 0;
char *str;
errno = 0;
str = strerror (0);
if (!*str) result |= 1;
if (errno) result |= 2;
if (strstr (str, "nknown") || strstr (str, "ndefined"))
result |= 4;
return result;]])],
[gl_cv_func_strerror_0_works=yes],
[gl_cv_func_strerror_0_works=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_strerror_0_works="guessing yes" ;;
# If we don't know, assume the worst.
*) gl_cv_func_strerror_0_works="guessing no" ;;
esac
])
])
case "$gl_cv_func_strerror_0_works" in
*yes) ;;
*)
REPLACE_STRERROR_0=1
AC_DEFINE([REPLACE_STRERROR_0], [1], [Define to 1 if strerror(0)
does not return a message implying success.])
;;
esac
])