--- a/xpcom/glue/nsISupportsUtils.h
+++ b/xpcom/glue/nsISupportsUtils.h
@@ -83,34 +83,34 @@ ns_if_addref( T expr )
  */
 #define NS_RELEASE(_ptr)                                                      \
   PR_BEGIN_MACRO                                                              \
     (_ptr)->Release();                                                        \
     (_ptr) = 0;                                                               \
   PR_END_MACRO
 
 /**
- * Macro for releasing a reference to an interface.
- * @param _ptr The interface pointer.
+ * Macro for releasing a reference to this interface.
  */
 #define NS_RELEASE_THIS() \
     Release()
 
 /**
  * Macro for releasing a reference to an interface, except that this
  * macro preserves the return value from the underlying Release call.
  * The interface pointer argument will only be NULLed if the reference count
  * goes to zero.
  *
  * @param _ptr The interface pointer.
+ * @param _rc  The reference count.
  */
-#define NS_RELEASE2(_ptr,_rv)                                                 \
+#define NS_RELEASE2(_ptr, _rc)                                                \
   PR_BEGIN_MACRO                                                              \
-    _rv = (_ptr)->Release();                                                  \
-    if (0 == (_rv)) (_ptr) = 0;                                               \
+    _rc = (_ptr)->Release();                                                  \
+    if (0 == (_rc)) (_ptr) = 0;                                               \
   PR_END_MACRO
 
 /**
  * Macro for releasing a reference to an interface that checks for NULL;
  * @param _ptr The interface pointer.
  */
 #define NS_IF_RELEASE(_ptr)                                                   \
   PR_BEGIN_MACRO                                                              \