isblank: Move AC_LIBOBJ invocations to module description.

[gnulib.git] / m4 / strerror.m4

diff --git a/m4/strerror.m4 b/m4/strerror.m4
index 25edd91..03a0b1a 100644 (file)
--- a/m4/strerror.m4
+++ b/m4/strerror.m4
@@ -1,4 +1,4 @@
-# strerror.m4 serial 12
+# strerror.m4 serial 15
 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,
@@ -8,6 +8,9 @@ AC_DEFUN([gl_FUNC_STRERROR],
 [
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
   AC_REQUIRE([gl_HEADER_ERRNO_H])
+  m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
+    AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
+  ])
   if test -z "$ERRNO_H"; then
     AC_CACHE_CHECK([for working strerror function],
      [gl_cv_func_working_strerror],
@@ -17,10 +20,14 @@ AC_DEFUN([gl_FUNC_STRERROR],
              #include <errno.h>
            ]],
            [[int result = 0;
+             char *str;
              if (!*strerror (-2)) result |= 1;
              errno = 0;
-             if (!*strerror (0)) result |= 2;
+             str = strerror (0);
+             if (!*str) result |= 2;
              if (errno) result |= 4;
+             if (strstr (str, "nknown") || strstr (str, "ndefined"))
+               result |= 8;
              return result;]])],
         [gl_cv_func_working_strerror=yes],
         [gl_cv_func_working_strerror=no],
@@ -32,22 +39,16 @@ AC_DEFUN([gl_FUNC_STRERROR],
       dnl integers. Replace it.
       REPLACE_STRERROR=1
     fi
+    m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
+      dnl If the system's strerror_r or __xpg_strerror_r clobbers strerror's
+      dnl buffer, we must replace strerror.
+      case "$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>. Replace it.
     REPLACE_STRERROR=1
   fi
 ])
-
-# 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
-])