[project @ 2003-06-30 14:17:02 by simonmar]

comments only.

diff --git a/ghc/includes/ClosureMacros.h b/ghc/includes/ClosureMacros.h
index 35140fc..5ddb934 100644 (file)
--- a/ghc/includes/ClosureMacros.h
+++ b/ghc/includes/ClosureMacros.h
@@ -1,5 +1,5 @@
 /* ----------------------------------------------------------------------------
- * $Id: ClosureMacros.h,v 1.36 2003/05/14 09:14:01 simonmar Exp $
+ * $Id: ClosureMacros.h,v 1.37 2003/06/30 14:17:02 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -207,6 +207,13 @@ extern StgWord flip;
 /* These macros are optimised versions of the above for certain
  * closure types.  They *must* be equivalent to the generic
  * STATIC_LINK.
+ *
+ * You may be surprised that the STATIC_LINK field for a THUNK_STATIC
+ * is at offset 2; that's because a THUNK_STATIC always has two words
+ * of (non-ptr) padding, to make room for the IND_STATIC that is
+ * going to overwrite it.  It doesn't do any harm, because a
+ * THUNK_STATIC needs this extra word for the IND_STATIC's saved_info
+ * field anyhow.  Hmm, this is all rather delicate. --SDM
  */
 #define FUN_STATIC_LINK(p)   ((p)->payload[0])
 #define THUNK_STATIC_LINK(p) ((p)->payload[2])