arch/all-pc/acpica/source/components/parser/pswalk.c

   1 /******************************************************************************
   2  *
   3  * Module Name: pswalk - Parser routines to walk parsed op tree(s)
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, 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 "acpi.h"
  46 #include "accommon.h"
  47 #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
  65 void
  66 AcpiPsDeleteParseTree (
  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 }