fpc/compiler/symnot.pas

{
    $Id$
    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,symtype;

type  Tnotification_flag=(vn_onread,vn_onwrite,vn_unknown);
      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 1.3  2003-10-22 15:22:33  peter
    * fixed unitsym-globalsymtable relation so the uses of a unit
      is counted correctly

  Revision 1.2  2002/12/31 09:55:58  daniel
   + Notification implementation complete
   + Add for loop code optimization using notifications
     results in 1.5-1.9% speed improvement in nestloop benchmark
     Optimization incomplete, compiler does not cycle yet with
     notifications enabled.

  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.

}