relocatable-prog-wrapper: Assume strerror() exists.

[pspp] / m4 / strerror.m4

diff --git a/m4/strerror.m4 b/m4/strerror.m4
index eb7d45aab205dd2c63a690ee2b56348fedb8e9ea..5e1c01185c48ad020bc7078306d2615962a251ac 100644 (file)
--- a/m4/strerror.m4
+++ b/m4/strerror.m4
@@ -1,42 +1,44 @@
-# strerror.m4 serial 7
-dnl Copyright (C) 2002, 2007 Free Software Foundation, Inc.
+# strerror.m4 serial 11
+dnl Copyright (C) 2002, 2007-2011 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_FUNC_STRERROR_SEPARATE])
-  if test $gl_cv_func_working_strerror = no; then
-    AC_LIBOBJ([strerror])
-    AC_DEFINE_UNQUOTED([REPLACE_STRERROR], [$REPLACE_STRERROR],
-      [Define this to 1 if strerror is broken.])
-  fi
-])
-
-# Like gl_FUNC_STRERROR, except prepare for separate compilation (no AC_LIBOBJ).
-AC_DEFUN([gl_FUNC_STRERROR_SEPARATE],
 [
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
-  AC_CACHE_CHECK([for working strerror function],
-   [gl_cv_func_working_strerror],
-   [AC_RUN_IFELSE(
-      [AC_LANG_PROGRAM(
-        [#include <string.h>
-        ],
-        [return !*strerror (-2);])],
-      [gl_cv_func_working_strerror=yes],
-      [gl_cv_func_working_strerror=no],
-      [dnl Assume crossbuild works if it compiles.
-       AC_COMPILE_IFELSE(
-        [AC_LANG_PROGRAM(
-           [#include <string.h>
-           ],
-           [return !*strerror (-2);])],
-        [gl_cv_func_working_strerror=yes],
-        [gl_cv_func_working_strerror=no])])])
-  if test $gl_cv_func_working_strerror = no ; then
+  AC_REQUIRE([gl_HEADER_ERRNO_H])
+  if test -z "$ERRNO_H"; 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;
+             if (!*strerror (-2)) result |= 1;
+             errno = 0;
+             if (!*strerror (0)) result |= 2;
+             if (errno) result |= 4;
+             return result;]])],
+        [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])
+    ])
+    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
+  else
+    dnl The system's strerror() cannot know about the new errno values we add
+    dnl to <errno.h>. Replace it.
     REPLACE_STRERROR=1
+  fi
+  if test $REPLACE_STRERROR = 1; then
+    AC_LIBOBJ([strerror])
     gl_PREREQ_STRERROR
   fi
 ])
@@ -44,4 +46,12 @@ AC_DEFUN([gl_FUNC_STRERROR_SEPARATE],
 # Prerequisites of lib/strerror.c.
 AC_DEFUN([gl_PREREQ_STRERROR], [
   AC_CHECK_DECLS([strerror])
+  AC_CHECK_HEADERS_ONCE([sys/socket.h])
+  if test $ac_cv_header_sys_socket_h != yes; then
+    dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
+    dnl the check for those headers unconditional; yet cygwin reports
+    dnl that the headers are present but cannot be compiled (since on
+    dnl cygwin, all socket information should come from sys/socket.h).
+    AC_CHECK_HEADERS([winsock2.h])
+  fi
 ])