1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: pswalk - Parser routines to walk parsed op tree(s)
5  *
6  * Copyright (C) 2000 - 2021, Intel Corp.
7  *
8  *****************************************************************************/
9 
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acparser.h"
13 
14 #define _COMPONENT          ACPI_PARSER
15 ACPI_MODULE_NAME("pswalk")
16 
17 /*******************************************************************************
18  *
19  * FUNCTION:    acpi_ps_delete_parse_tree
20  *
21  * PARAMETERS:  subtree_root        - Root of tree (or subtree) to delete
22  *
23  * RETURN:      None
24  *
25  * DESCRIPTION: Delete a portion of or an entire parse tree.
26  *
27  ******************************************************************************/
28 #include "amlcode.h"
acpi_ps_delete_parse_tree(union acpi_parse_object * subtree_root)29 void acpi_ps_delete_parse_tree(union acpi_parse_object *subtree_root)
30 {
31 	union acpi_parse_object *op = subtree_root;
32 	union acpi_parse_object *next = NULL;
33 	union acpi_parse_object *parent = NULL;
34 	u32 level = 0;
35 
36 	ACPI_FUNCTION_TRACE_PTR(ps_delete_parse_tree, subtree_root);
37 
38 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE_TREES, " root %p\n", subtree_root));
39 
40 	/* Visit all nodes in the subtree */
41 
42 	while (op) {
43 		if (op != parent) {
44 
45 			/* This is the descending case */
46 
47 			if (ACPI_IS_DEBUG_ENABLED
48 			    (ACPI_LV_PARSE_TREES, _COMPONENT)) {
49 
50 				/* This debug option will print the entire parse tree */
51 
52 				acpi_os_printf("      %*.s%s %p", (level * 4),
53 					       " ",
54 					       acpi_ps_get_opcode_name(op->
55 								       common.
56 								       aml_opcode),
57 					       op);
58 
59 				if (op->named.aml_opcode == AML_INT_NAMEPATH_OP) {
60 					acpi_os_printf("  %4.4s",
61 						       op->common.value.string);
62 				}
63 				if (op->named.aml_opcode == AML_STRING_OP) {
64 					acpi_os_printf("  %s",
65 						       op->common.value.string);
66 				}
67 				acpi_os_printf("\n");
68 			}
69 
70 			/* Look for an argument or child of the current op */
71 
72 			next = acpi_ps_get_arg(op, 0);
73 			if (next) {
74 
75 				/* Still going downward in tree (Op is not completed yet) */
76 
77 				op = next;
78 				level++;
79 				continue;
80 			}
81 		}
82 
83 		/* No more children, this Op is complete. */
84 
85 		next = op->common.next;
86 		parent = op->common.parent;
87 
88 		acpi_ps_free_op(op);
89 
90 		/* If we are back to the starting point, the walk is complete. */
91 
92 		if (op == subtree_root) {
93 			return_VOID;
94 		}
95 
96 		if (next) {
97 			op = next;
98 		} else {
99 			level--;
100 			op = parent;
101 		}
102 	}
103 
104 	return_VOID;
105 }
106