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flow.c

 /*
  * plint/prog/flow.c : program flow handling
  * 
  * Time-stamp: <2002-12-21 14:41:27 gseba>
  * 
  * Copyright (C) Sebastian Glita, email: gseba@users.sourceforge.net
  * 
  * This file is part of plint.
  * 
  * plint 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, or (at your option) any later version.
  *
  * plint  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  plint; see  the file  COPYING.  If  not, write  to the  Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA USA.
  *
  */

#pragma GCC dependency "Makefile" maybe some command line defines have changed

#include "plint.h"
#include "error.h"
#include "share.h"

#include "data.h"
#include "flow.h"
#include "block.h"
#include "stack.h"

#include "parse/mylex.h"



inline void plint_block_push(plint_tree_t t)
{
  plint_stack_push(t);
}

inline void plint_block_pop()
{
  plint_stack_pop();
}


static int block_exit()
{
  return !0;
}
void plint_exit_start()
{
  plint->flow.ctl.type = PLINT_CTL_EXIT;
  plint->flow.ctl.count = -1;

  PLINT_LEX_EOF;
}


static int block_escape()
{
  if (plint->flow.ctl.parm.escp == plint_stack.top->block.src)
    if (--plint->flow.ctl.count)
      plint->flow.ctl.parm.escp = plint_tree_non_ins(plint_stack.top->proc->block.src->prnt);

  return !!plint->flow.ctl.count;
}
void plint_escape_start()
{
  plint->flow.ctl.parm.escp = plint_tree_non_ins(plint_stack.top->proc->block.src->prnt);

  plint->flow.ctl.type = PLINT_CTL_ESCP;
  if (plint->flow.ctl.count == -1)
    plint->flow.ctl.count = 0;

  ++plint->flow.ctl.count;

  PLINT_LEX_EOF;
}


static int block_return()
{
  if (plint->flow.ctl.parm.retn == plint_stack.top) /* current top block is a procedure */
    if (--plint->flow.ctl.count)
      plint->flow.ctl.parm.retn = plint_stack.top->down->proc; /* who's the calling procedure ? */

  return !0;
}
void plint_return_start()
{
  /* first, let's see who's the on top */
  plint->flow.ctl.parm.retn = plint_stack.top->proc;

  plint->flow.ctl.type= PLINT_CTL_RETN;
  if (plint->flow.ctl.count == -1)
    plint->flow.ctl.count = 0;

  ++plint->flow.ctl.count;

  block_return();

  PLINT_LEX_EOF;
}


static int block_ctrl()
{
  --plint->flow.ctl.count;
  return !0;
}
void plint_ctrl_start(plint_ectl_t ctl)
{
  plint->flow.ctl.type = ctl;

  if (plint->flow.ctl.count == -1)
    plint->flow.ctl.count = 1;

  PLINT_LEX_EOF;
}


static int block_extension()
{
  return PLINT_MAP_BLOCK(CONTROL, plint_stack.top->block.src->blk, &plint_stack.top->block);
}
void plint_flow_start(int count, int type, void * data)
{
  plint->flow.ctl.type= PLINT_CTL_EXTN;
  plint->flow.ctl.count = count;
  slot_setdata(plint->flow.ext, plint->flow.ctl.parm.extn = type, data);

  PLINT_LEX_EOF;
}

int plint_flow_register(freefunc_t f)
{
  return slot_register(plint->flow.ext, 0, f);
}

void plint_flow_unregister(int type)
{
  slot_unregister(plint->flow.ext, type);
}

int (* const plint_map_ctl[_PLINT_CTL_NO])() =
{
  [PLINT_CTL_EXIT] = block_exit,
  [PLINT_CTL_RETN] = block_return,
  [PLINT_CTL_ESCP] = block_escape,
  [PLINT_CTL_BREK] = block_ctrl,
  [PLINT_CTL_CONT] = block_ctrl,
  [PLINT_CTL_LOOP] = block_ctrl,
  [PLINT_CTL_EXTN] = block_extension,
};

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