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/******************************************************************************
*
* Module Name: pswalk - Parser routines to walk parsed op tree(s)
* $Revision: 58 $
*
*****************************************************************************/
/*
* Copyright (C) 2000, 2001 R. Byron Moore
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "acpi.h"
#include "amlcode.h"
#include "acparser.h"
#include "acdispat.h"
#include "acnamesp.h"
#include "acinterp.h"
#define _COMPONENT ACPI_PARSER
MODULE_NAME ("pswalk")
/*******************************************************************************
*
* FUNCTION: Acpi_ps_get_next_walk_op
*
* PARAMETERS: Walk_state - Current state of the walk
* Op - Current Op to be walked
* Ascending_callback - Procedure called when Op is complete
*
* RETURN: Status
*
* DESCRIPTION: Get the next Op in a walk of the parse tree.
*
******************************************************************************/
acpi_status
acpi_ps_get_next_walk_op (
acpi_walk_state *walk_state,
acpi_parse_object *op,
acpi_parse_upwards ascending_callback)
{
acpi_parse_object *next;
acpi_parse_object *parent;
acpi_parse_object *grand_parent;
acpi_status status;
FUNCTION_TRACE_PTR ("Ps_get_next_walk_op", op);
/* Check for a argument only if we are descending in the tree */
if (walk_state->next_op_info != NEXT_OP_UPWARD) {
/* Look for an argument or child of the current op */
next = acpi_ps_get_arg (op, 0);
if (next) {
/* Still going downward in tree (Op is not completed yet) */
walk_state->prev_op = op;
walk_state->next_op = next;
walk_state->next_op_info = NEXT_OP_DOWNWARD;
return_ACPI_STATUS (AE_OK);
}
/*
* No more children, this Op is complete. Save Next and Parent
* in case the Op object gets deleted by the callback routine
*/
next = op->next;
parent = op->parent;
walk_state->op = op;
walk_state->op_info = acpi_ps_get_opcode_info (op->opcode);
walk_state->opcode = op->opcode;
status = ascending_callback (walk_state);
/*
* If we are back to the starting point, the walk is complete.
*/
if (op == walk_state->origin) {
/* Reached the point of origin, the walk is complete */
walk_state->prev_op = op;
walk_state->next_op = NULL;
return_ACPI_STATUS (status);
}
/*
* Check for a sibling to the current op. A sibling means
* we are still going "downward" in the tree.
*/
if (next) {
/* There is a sibling, it will be next */
walk_state->prev_op = op;
walk_state->next_op = next;
walk_state->next_op_info = NEXT_OP_DOWNWARD;
/* Continue downward */
return_ACPI_STATUS (status);
}
/*
* Drop into the loop below because we are moving upwards in
* the tree
*/
}
else {
/*
* We are resuming a walk, and we were (are) going upward in the tree.
* So, we want to drop into the parent loop below.
*/
parent = op;
}
/*
* Look for a sibling of the current Op's parent
* Continue moving up the tree until we find a node that has not been
* visited, or we get back to where we started.
*/
while (parent) {
/* We are moving up the tree, therefore this parent Op is complete */
grand_parent = parent->parent;
next = parent->next;
walk_state->op = parent;
walk_state->op_info = acpi_ps_get_opcode_info (parent->opcode);
walk_state->opcode = parent->opcode;
status = ascending_callback (walk_state);
/*
* If we are back to the starting point, the walk is complete.
*/
if (parent == walk_state->origin) {
/* Reached the point of origin, the walk is complete */
walk_state->prev_op = parent;
walk_state->next_op = NULL;
return_ACPI_STATUS (status);
}
/*
* If there is a sibling to this parent (it is not the starting point
* Op), then we will visit it.
*/
if (next) {
/* found sibling of parent */
walk_state->prev_op = parent;
walk_state->next_op = next;
walk_state->next_op_info = NEXT_OP_DOWNWARD;
return_ACPI_STATUS (status);
}
/* No siblings, no errors, just move up one more level in the tree */
op = parent;
parent = grand_parent;
walk_state->prev_op = op;
}
/* Got all the way to the top of the tree, we must be done! */
/* However, the code should have terminated in the loop above */
walk_state->next_op = NULL;
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: Acpi_ps_delete_completed_op
*
* PARAMETERS: State - Walk state
* Op - Completed op
*
* RETURN: AE_OK
*
* DESCRIPTION: Callback function for Acpi_ps_get_next_walk_op(). Used during
* Acpi_ps_delete_parse tree to delete Op objects when all sub-objects
* have been visited (and deleted.)
*
******************************************************************************/
static acpi_status
acpi_ps_delete_completed_op (
acpi_walk_state *walk_state)
{
acpi_ps_free_op (walk_state->op);
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: Acpi_ps_delete_parse_tree
*
* PARAMETERS: Subtree_root - Root of tree (or subtree) to delete
*
* RETURN: None
*
* DESCRIPTION: Delete a portion of or an entire parse tree.
*
******************************************************************************/
void
acpi_ps_delete_parse_tree (
acpi_parse_object *subtree_root)
{
acpi_walk_state *walk_state;
acpi_walk_list walk_list;
FUNCTION_TRACE_PTR ("Ps_delete_parse_tree", subtree_root);
if (!subtree_root) {
return_VOID;
}
/* Create and initialize a new walk list */
walk_list.walk_state = NULL;
walk_list.acquired_mutex_list.prev = NULL;
walk_list.acquired_mutex_list.next = NULL;
walk_state = acpi_ds_create_walk_state (TABLE_ID_DSDT, NULL, NULL, &walk_list);
if (!walk_state) {
return_VOID;
}
walk_state->parse_flags = 0;
walk_state->descending_callback = NULL;
walk_state->ascending_callback = NULL;
walk_state->origin = subtree_root;
walk_state->next_op = subtree_root;
/* Head downward in the tree */
walk_state->next_op_info = NEXT_OP_DOWNWARD;
/* Visit all nodes in the subtree */
while (walk_state->next_op) {
acpi_ps_get_next_walk_op (walk_state, walk_state->next_op,
acpi_ps_delete_completed_op);
}
/* We are done with this walk */
acpi_ex_release_all_mutexes ((acpi_operand_object *) &walk_list.acquired_mutex_list);
acpi_ds_delete_walk_state (walk_state);
return_VOID;
}
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