isblank: Move AC_LIBOBJ invocations to module description.

[gnulib.git] / m4 / strerror.m4

diff --git a/m4/strerror.m4 b/m4/strerror.m4
index 1649b24..03a0b1a 100644 (file)
--- a/m4/strerror.m4
+++ b/m4/strerror.m4
@@ -1,68 +1,54 @@
-# strerror.m4 serial 9
-dnl Copyright (C) 2002, 2007-2010 Free Software Foundation, Inc.
+# 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,
 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 $REPLACE_STRERROR = 1; then
-    AC_LIBOBJ([strerror])
-    AC_DEFINE_UNQUOTED([REPLACE_STRERROR], [$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_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],
      [AC_RUN_IFELSE(
         [AC_LANG_PROGRAM(
            [[#include <string.h>
+             #include <errno.h>
            ]],
-           [[return !*strerror (-2);]])],
+           [[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;]])],
         [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])
-      ])
+        [dnl Be pessimistic on cross-compiles for now.
+         gl_cv_func_working_strerror=no])
     ])
     if test $gl_cv_func_working_strerror = no; then
       dnl The system's strerror() fails to return a string for out-of-range
       dnl integers. Replace it.
       REPLACE_STRERROR=1
     fi
+    m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [
+      dnl If the system's strerror_r or __xpg_strerror_r clobbers strerror's
+      dnl buffer, we must replace strerror.
+      case "$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
-  if test $REPLACE_STRERROR = 1; then
-    gl_PREREQ_STRERROR
-  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
 ])