xref: /freebsd/sys/contrib/dev/acpica/components/parser/pswalk.c (revision 076ad2f836d5f49dc1375f1677335a48fe0d4b82)
1 /******************************************************************************
2  *
3  * Module Name: pswalk - Parser routines to walk parsed op tree(s)
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, 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 #include <contrib/dev/acpica/include/acpi.h>
45 #include <contrib/dev/acpica/include/accommon.h>
46 #include <contrib/dev/acpica/include/acparser.h>
47 
48 #define _COMPONENT          ACPI_PARSER
49         ACPI_MODULE_NAME    ("pswalk")
50 
51 
52 /*******************************************************************************
53  *
54  * FUNCTION:    AcpiPsDeleteParseTree
55  *
56  * PARAMETERS:  SubtreeRoot         - Root of tree (or subtree) to delete
57  *
58  * RETURN:      None
59  *
60  * DESCRIPTION: Delete a portion of or an entire parse tree.
61  *
62  ******************************************************************************/
63 
64 void
65 AcpiPsDeleteParseTree (
66     ACPI_PARSE_OBJECT       *SubtreeRoot)
67 {
68     ACPI_PARSE_OBJECT       *Op = SubtreeRoot;
69     ACPI_PARSE_OBJECT       *Next = NULL;
70     ACPI_PARSE_OBJECT       *Parent = NULL;
71 
72 
73     ACPI_FUNCTION_TRACE_PTR (PsDeleteParseTree, SubtreeRoot);
74 
75 
76     /* Visit all nodes in the subtree */
77 
78     while (Op)
79     {
80         /* Check if we are not ascending */
81 
82         if (Op != Parent)
83         {
84             /* Look for an argument or child of the current op */
85 
86             Next = AcpiPsGetArg (Op, 0);
87             if (Next)
88             {
89                 /* Still going downward in tree (Op is not completed yet) */
90 
91                 Op = Next;
92                 continue;
93             }
94         }
95 
96         /* No more children, this Op is complete. */
97 
98         Next = Op->Common.Next;
99         Parent = Op->Common.Parent;
100 
101         AcpiPsFreeOp (Op);
102 
103         /* If we are back to the starting point, the walk is complete. */
104 
105         if (Op == SubtreeRoot)
106         {
107             return_VOID;
108         }
109 
110         if (Next)
111         {
112             Op = Next;
113         }
114         else
115         {
116             Op = Parent;
117         }
118     }
119 
120     return_VOID;
121 }
122