pandora-build v0.74

[awesomized/libmemcached] / m4 / pandora_stack_direction.m4

diff --git a/m4/pandora_stack_direction.m4 b/m4/pandora_stack_direction.m4
new file mode 100644 (file)
index 0000000..635586a
--- /dev/null
+++ b/m4/pandora_stack_direction.m4
@@ -0,0 +1,39 @@
+dnl  Copyright (C) 2009 Sun Microsystems
+dnl This file is free software; Sun Microsystems
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+#--------------------------------------------------------------------
+# Check what direction the stack runs in
+#--------------------------------------------------------------------
+
+AC_DEFUN([PANDORA_STACK_DIRECTION],[
+ AC_REQUIRE([AC_FUNC_ALLOCA])
+ AC_CACHE_CHECK([stack direction], [ac_cv_c_stack_direction],[
+  AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <stdlib.h>
+ int find_stack_direction ()
+ {
+   static char *addr = 0;
+   auto char dummy;
+   if (addr == 0)
+     {
+       addr = &dummy;
+       return find_stack_direction ();
+     }
+   else
+     return (&dummy > addr) ? 1 : -1;
+ }
+  ]],[[
+    exit (find_stack_direction() < 0);
+  ]])],[
+   ac_cv_c_stack_direction=1
+  ],[
+   ac_cv_c_stack_direction=-1
+  ])
+ ])
+ AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction)
+])
+
+
+