freebsd-dev/source/components/parser/pswalk.c
2012-02-16 00:24:10 +00:00

122 lines
3.7 KiB
C

/******************************************************************************
*
* Module Name: pswalk - Parser routines to walk parsed op tree(s)
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2012, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include "acpi.h"
#include "accommon.h"
#include "acparser.h"
#define _COMPONENT ACPI_PARSER
ACPI_MODULE_NAME ("pswalk")
/*******************************************************************************
*
* FUNCTION: AcpiPsDeleteParseTree
*
* PARAMETERS: SubtreeRoot - Root of tree (or subtree) to delete
*
* RETURN: None
*
* DESCRIPTION: Delete a portion of or an entire parse tree.
*
******************************************************************************/
void
AcpiPsDeleteParseTree (
ACPI_PARSE_OBJECT *SubtreeRoot)
{
ACPI_PARSE_OBJECT *Op = SubtreeRoot;
ACPI_PARSE_OBJECT *Next = NULL;
ACPI_PARSE_OBJECT *Parent = NULL;
ACPI_FUNCTION_TRACE_PTR (PsDeleteParseTree, SubtreeRoot);
/* Visit all nodes in the subtree */
while (Op)
{
/* Check if we are not ascending */
if (Op != Parent)
{
/* Look for an argument or child of the current op */
Next = AcpiPsGetArg (Op, 0);
if (Next)
{
/* Still going downward in tree (Op is not completed yet) */
Op = Next;
continue;
}
}
/* No more children, this Op is complete. */
Next = Op->Common.Next;
Parent = Op->Common.Parent;
AcpiPsFreeOp (Op);
/* If we are back to the starting point, the walk is complete. */
if (Op == SubtreeRoot)
{
return_VOID;
}
if (Next)
{
Op = Next;
}
else
{
Op = Parent;
}
}
return_VOID;
}