1# strerror.m4 serial 9
2dnl Copyright (C) 2002, 2007, 2008, 2009 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_DEFUN([gl_FUNC_STRERROR],
8[
9  AC_REQUIRE([gl_FUNC_STRERROR_SEPARATE])
10  if test $REPLACE_STRERROR = 1; then
11    AC_LIBOBJ([strerror])
12    AC_DEFINE_UNQUOTED([REPLACE_STRERROR], [$REPLACE_STRERROR],
13      [Define this to 1 if strerror is broken.])
14  fi
15])
16
17# Like gl_FUNC_STRERROR, except prepare for separate compilation (no AC_LIBOBJ).
18AC_DEFUN([gl_FUNC_STRERROR_SEPARATE],
19[
20  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
21  AC_REQUIRE([gl_HEADER_ERRNO_H])
22  if test -z "$ERRNO_H"; then
23    AC_CACHE_CHECK([for working strerror function],
24     [gl_cv_func_working_strerror],
25     [AC_RUN_IFELSE(
26        [AC_LANG_PROGRAM(
27           [[#include <string.h>
28           ]],
29           [[return !*strerror (-2);]])],
30        [gl_cv_func_working_strerror=yes],
31        [gl_cv_func_working_strerror=no],
32        [dnl Assume crossbuild works if it compiles.
33         AC_COMPILE_IFELSE(
34           [AC_LANG_PROGRAM(
35              [[#include <string.h>
36              ]],
37              [[return !*strerror (-2);]])],
38           [gl_cv_func_working_strerror=yes],
39           [gl_cv_func_working_strerror=no])
40      ])
41    ])
42    if test $gl_cv_func_working_strerror = no; then
43      dnl The system's strerror() fails to return a string for out-of-range
44      dnl integers. Replace it.
45      REPLACE_STRERROR=1
46    fi
47  else
48    dnl The system's strerror() cannot know about the new errno values we add
49    dnl to <errno.h>. Replace it.
50    REPLACE_STRERROR=1
51  fi
52  if test $REPLACE_STRERROR = 1; then
53    gl_PREREQ_STRERROR
54  fi
55])
56
57# Prerequisites of lib/strerror.c.
58AC_DEFUN([gl_PREREQ_STRERROR], [
59  AC_CHECK_DECLS([strerror])
60  AC_CHECK_HEADERS_ONCE([sys/socket.h])
61  if test $ac_cv_header_sys_socket_h != yes; then
62    dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
63    dnl the check for those headers unconditional; yet cygwin reports
64    dnl that the headers are present but cannot be compiled (since on
65    dnl cygwin, all socket information should come from sys/socket.h).
66    AC_CHECK_HEADERS([winsock2.h])
67  fi
68])
69