pswalk.c revision 217365 
1/******************************************************************************
2 *
3 * Module Name: pswalk - Parser routines to walk parsed op tree(s)
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2011, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions, and the following disclaimer,
16 *    without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 *    substantially similar to the "NO WARRANTY" disclaimer below
19 *    ("Disclaimer") and any redistribution must be conditioned upon
20 *    including a substantially similar Disclaimer requirement for further
21 *    binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 *    of any contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44
45#include <contrib/dev/acpica/include/acpi.h>
46#include <contrib/dev/acpica/include/accommon.h>
47#include <contrib/dev/acpica/include/acparser.h>
48
49#define _COMPONENT          ACPI_PARSER
50        ACPI_MODULE_NAME    ("pswalk")
51
52
53/*******************************************************************************
54 *
55 * FUNCTION:    AcpiPsDeleteParseTree
56 *
57 * PARAMETERS:  SubtreeRoot         - Root of tree (or subtree) to delete
58 *
59 * RETURN:      None
60 *
61 * DESCRIPTION: Delete a portion of or an entire parse tree.
62 *
63 ******************************************************************************/
64
65void
66AcpiPsDeleteParseTree (
67    ACPI_PARSE_OBJECT       *SubtreeRoot)
68{
69    ACPI_PARSE_OBJECT       *Op = SubtreeRoot;
70    ACPI_PARSE_OBJECT       *Next = NULL;
71    ACPI_PARSE_OBJECT       *Parent = NULL;
72
73
74    ACPI_FUNCTION_TRACE_PTR (PsDeleteParseTree, SubtreeRoot);
75
76
77    /* Visit all nodes in the subtree */
78
79    while (Op)
80    {
81        /* Check if we are not ascending */
82
83        if (Op != Parent)
84        {
85            /* Look for an argument or child of the current op */
86
87            Next = AcpiPsGetArg (Op, 0);
88            if (Next)
89            {
90                /* Still going downward in tree (Op is not completed yet) */
91
92                Op = Next;
93                continue;
94            }
95        }
96
97        /* No more children, this Op is complete. */
98
99        Next = Op->Common.Next;
100        Parent = Op->Common.Parent;
101
102        AcpiPsFreeOp (Op);
103
104        /* If we are back to the starting point, the walk is complete. */
105
106        if (Op == SubtreeRoot)
107        {
108            return_VOID;
109        }
110        if (Next)
111        {
112            Op = Next;
113        }
114        else
115        {
116            Op = Parent;
117        }
118    }
119
120    return_VOID;
121}
122