+ Added read/write notifications of variables. These will be usefull

   for providing information for several optimizations. For example
   the value of the loop variable of a for loop does matter is the
   variable is read after the for loop, but if it's no longer used
   or written, it doesn't matter and this can be used to optimize
   the loop code generation.

compiler/symnot.pas

@@ -0,0 +1,76 @@
+{
+    $Id$
+    Copyright (c) 2002 by Daniel Mantione
+
+    This unit contains support routines for the variable access
+    notifier.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ ****************************************************************************
+}
+
+unit symnot;
+
+{$i fpcdefs.inc}
+
+interface
+
+uses  cclasses,symbase,symtype;
+
+type  Tnotification_flag=(vn_onread,vn_onwrite);
+      Tnotification_flags=set of Tnotification_flag;
+
+      Tnotification_callback=procedure(not_type:Tnotification_flag;
+                                       symbol:Tsym) of object;
+
+      Tnotification=class(Tlinkedlistitem)
+        flags:Tnotification_flags;
+        callback:Tnotification_callback;
+        id:cardinal;
+        constructor create(Aflags:Tnotification_flags;
+                           Acallback:Tnotification_callback);
+      end;
+
+implementation
+
+var notification_counter:cardinal;
+
+constructor Tnotification.create(Aflags:Tnotification_flags;
+                                 Acallback:Tnotification_callback);
+
+begin
+  inherited create;
+  flags:=Aflags;
+  callback:=Acallback;
+  id:=notification_counter;
+  inc(notification_counter);
+end;
+
+begin
+  notification_counter:=0;
+end.
+
+{
+  $Log$
+  Revision 1.1  2002-09-01 08:04:42  daniel
+   + Added read/write notifications of variables. These will be usefull
+     for providing information for several optimizations. For example
+     the value of the loop variable of a for loop does matter is the
+     variable is read after the for loop, but if it's no longer used
+     or written, it doesn't matter and this can be used to optimize
+     the loop code generation.
+
+}