-# strerror.m4 serial 15
-dnl Copyright (C) 2002, 2007-2011 Free Software Foundation, Inc.
+# strerror.m4 serial 17
+dnl Copyright (C) 2002, 2007-2013 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_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 -z "$ERRNO_H"; then
+ if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then
AC_CACHE_CHECK([for working strerror function],
[gl_cv_func_working_strerror],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[#include <string.h>
- #include <errno.h>
]],
- [[int result = 0;
- char *str;
- if (!*strerror (-2)) result |= 1;
- errno = 0;
- str = strerror (0);
- if (!*str) result |= 2;
- if (errno) result |= 4;
- if (strstr (str, "nknown") || strstr (str, "ndefined"))
- result |= 8;
- return result;]])],
+ [[if (!*strerror (-2)) return 1;]])],
[gl_cv_func_working_strerror=yes],
[gl_cv_func_working_strerror=no],
- [dnl Be pessimistic on cross-compiles for now.
- gl_cv_func_working_strerror=no])
+ [case "$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
+ ])
])
- if test $gl_cv_func_working_strerror = no; then
- dnl The system's strerror() fails to return a string for out-of-range
- dnl integers. Replace it.
- REPLACE_STRERROR=1
- fi
+ case "$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.
])
else
dnl The system's strerror() cannot know about the new errno values we add
- dnl to <errno.h>. Replace it.
+ 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
+])