| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Module Name: pswalk - Parser routines to walk parsed op tree(s) |
| 4 | * |
| 5 | *****************************************************************************/ |
| 6 | |
| 7 | /* |
| 8 | * Copyright (C) 2000 - 2005, R. Byron Moore |
| 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 <acpi/acpi.h> |
| 46 | #include <acpi/acparser.h> |
| 47 | |
| 48 | #define _COMPONENT ACPI_PARSER |
| 49 | ACPI_MODULE_NAME ("pswalk") |
| 50 | |
| 51 | |
| 52 | /******************************************************************************* |
| 53 | * |
| 54 | * FUNCTION: acpi_ps_delete_parse_tree |
| 55 | * |
| 56 | * PARAMETERS: subtree_root - 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 | acpi_ps_delete_parse_tree ( |
| 66 | union acpi_parse_object *subtree_root) |
| 67 | { |
| 68 | union acpi_parse_object *op = subtree_root; |
| 69 | union acpi_parse_object *next = NULL; |
| 70 | union acpi_parse_object *parent = NULL; |
| 71 | |
| 72 | |
| 73 | ACPI_FUNCTION_TRACE_PTR ("ps_delete_parse_tree", subtree_root); |
| 74 | |
| 75 | |
| 76 | /* Visit all nodes in the subtree */ |
| 77 | |
| 78 | while (op) { |
| 79 | /* Check if we are not ascending */ |
| 80 | |
| 81 | if (op != parent) { |
| 82 | /* Look for an argument or child of the current op */ |
| 83 | |
| 84 | next = acpi_ps_get_arg (op, 0); |
| 85 | if (next) { |
| 86 | /* Still going downward in tree (Op is not completed yet) */ |
| 87 | |
| 88 | op = next; |
| 89 | continue; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * No more children, this Op is complete. |
| 95 | */ |
| 96 | next = op->common.next; |
| 97 | parent = op->common.parent; |
| 98 | |
| 99 | acpi_ps_free_op (op); |
| 100 | |
| 101 | /* |
| 102 | * If we are back to the starting point, the walk is complete. |
| 103 | */ |
| 104 | if (op == subtree_root) { |
| 105 | return_VOID; |
| 106 | } |
| 107 | if (next) { |
| 108 | op = next; |
| 109 | } |
| 110 | else { |
| 111 | op = parent; |
| 112 | } |
| 113 | } |
| 114 | return_VOID; |
| 115 | } |