gc.h: IS_STACK_DIR_UPPER

* gc.h (IS_STACK_DIR_UPPER): utility macro.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36015 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,6 @@
-Sun Jun 10 17:54:31 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Sun Jun 10 17:54:36 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* gc.h (IS_STACK_DIR_UPPER): utility macro.
 
 	* thread_pthread.c (get_stack): seems stack size does not include
 	  guard size on Mac OS X.

gc.h

@@ -81,6 +81,7 @@ int ruby_get_stack_grow_direction(volatile VALUE *addr);
 #define STACK_GROW_DIR_DETECTION VALUE stack_grow_dir_detection
 #define STACK_DIR_UPPER(a,b) STACK_UPPER(&stack_grow_dir_detection, (a), (b))
 #endif
+#define IS_STACK_DIR_UPPER() STACK_DIR_UPPER(1,0)
 
 #if defined __GNUC__ && __GNUC__ >= 4
 #pragma GCC visibility push(default)

thread_pthread.c

@@ -1342,7 +1342,7 @@ ruby_stack_overflowed_p(const rb_thread_t *th, const void *addr)
     }
     size /= 5;
     if (size > water_mark) size = water_mark;
-    if (STACK_DIR_UPPER(1, 0)) {
+    if (IS_STACK_DIR_UPPER()) {
 	if (size > ~(size_t)base+1) size = ~(size_t)base+1;
 	if (addr > base && addr <= (void *)((char *)base + size)) return 1;
     }