ignore-value: support aggregate types

[gnulib.git] / m4 / dup2.m4

diff --git a/m4/dup2.m4 b/m4/dup2.m4
index a74e915..bc2f417 100644 (file)
--- a/m4/dup2.m4
+++ b/m4/dup2.m4
@@ -1,5 +1,5 @@
-#serial 9
-dnl Copyright (C) 2002, 2005, 2007, 2009 Free Software Foundation, Inc.
+#serial 11
+dnl Copyright (C) 2002, 2005, 2007, 2009-2011 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.
@@ -17,42 +17,43 @@ AC_DEFUN([gl_FUNC_DUP2],
       [AC_RUN_IFELSE([
          AC_LANG_PROGRAM([[#include <unistd.h>
 #include <errno.h>]],
-           [if (dup2 (1, 1) == 0)
-              return 1;
+           [int result = 0;
+            if (dup2 (1, 1) == 0)
+              result |= 1;
             close (0);
             if (dup2 (0, 0) != -1)
-              return 2;
+              result |= 2;
             /* Many gnulib modules require POSIX conformance of EBADF.  */
             if (dup2 (1, 1000000) == -1 && errno != EBADF)
-              return 3;
-            return 0;
+              result |= 4;
+            return result;
            ])
         ],
-       [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
-       [case "$host_os" in
-          mingw*) # on this platform, dup2 always returns 0 for success
-            gl_cv_func_dup2_works=no;;
-          cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
-            gl_cv_func_dup2_works=no;;
-          linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a
-                  # closed fd may yield -EBADF instead of -1 / errno=EBADF.
-            gl_cv_func_dup2_works=no;;
+        [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+        [case "$host_os" in
+           mingw*) # on this platform, dup2 always returns 0 for success
+             gl_cv_func_dup2_works=no;;
+           cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+             gl_cv_func_dup2_works=no;;
+           linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a
+                   # closed fd may yield -EBADF instead of -1 / errno=EBADF.
+             gl_cv_func_dup2_works=no;;
            freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
-            gl_cv_func_dup2_works=no;;
-          *) gl_cv_func_dup2_works=yes;;
-        esac])
+             gl_cv_func_dup2_works=no;;
+           *) gl_cv_func_dup2_works=yes;;
+         esac])
       ])
     if test "$gl_cv_func_dup2_works" = no; then
       gl_REPLACE_DUP2
     fi
   fi
-  AC_DEFINE_UNQUOTED([REPLACE_DUP2], [$REPLACE_DUP2],
-    [Define to 1 if dup2 returns 0 instead of the target fd.])
 ])
 
 AC_DEFUN([gl_REPLACE_DUP2],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  REPLACE_DUP2=1
+  if test $ac_cv_func_dup2 = yes; then
+    REPLACE_DUP2=1
+  fi
   AC_LIBOBJ([dup2])
 ])