/* Generic dominator tree walker
   Copyright (C) 2003 Free Software Foundation, Inc.
   Contributed by Diego Novillo <dnovillo@redhat.com>

This file is part of GCC.

GCC 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.

GCC 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 GCC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* This is the main data structure for the dominator walker.  It provides
   the callback hooks as well as a convenient place to hang block local
   data.  Eventually it will probably include pass global data as well.  */

struct dom_walk_data
{
  /* Function to initialize block local data.

     Note that the dominator walker infrastructure may provide a new
     fresh, and zero'd block local data structure, or it may re-use an
     existing block local data structure.

     If the block local structure has items such as virtual arrays, then
     that allows your optimizer to re-use those arrays rather than
     creating new ones.  */
  void (*initialize_block_local_data) (struct dom_walk_data *,
				       basic_block, bool);

  /* Function to call before the statement walk occurring before the
     recursive walk of the dominator children. 

     This typically initializes an block local data and pushes that
     data onto BLOCK_DATA_STACK.  */
  void (*before_dom_children_before_stmts) (struct dom_walk_data *,
					    basic_block, tree);

  /* Function to call to walk statements before the recursive walk
     of the dominator children.  */
  void (*before_dom_children_walk_stmts) (struct dom_walk_data *,
					  basic_block, tree);

  /* Function to call after the statement walk occurring before the
     recursive walk of the dominator children.  */
  void (*before_dom_children_after_stmts) (struct dom_walk_data *,
					   basic_block, tree);

  /* Function to call before the statement walk occurring after the
     recursive walk of the dominator children.  */
  void (*after_dom_children_before_stmts) (struct dom_walk_data *,
					   basic_block, tree);

  /* Function to call to walk statements after the recursive walk
     of the dominator children.  */
  void (*after_dom_children_walk_stmts) (struct dom_walk_data *,
					 basic_block, tree);

  /* Function to call after the statement walk occurring after the
     recursive walk of the dominator children. 

     This typically finalizes any block local data and pops
     that data from BLOCK_DATA_STACK.  */
  void (*after_dom_children_after_stmts) (struct dom_walk_data *,
					  basic_block, tree);

  /* Global data for a walk through the dominator tree.  */
  void *global_data;

  /* Stack of any data we need to keep on a per-block basis.

     If you have no local data, then BLOCK_DATA_STACK will be NULL.  */
  varray_type block_data_stack;

  /* Size of the block local data.   If this is zero, then it is assumed
     you have no local data and thus no BLOCK_DATA_STACK as well.  */
  size_t block_local_data_size;

  /* From here below are private data.  Please do not use this
     information/data outside domwalk.c.  */

  /* Stack of available block local structures.   */
  varray_type free_block_data;
};

void walk_dominator_tree (struct dom_walk_data *, basic_block, tree);
void init_walk_dominator_tree (struct dom_walk_data *);
void fini_walk_dominator_tree (struct dom_walk_data *);