text: /******************************************************************************
   *
   * Module Name: asllookup- Namespace lookup functions
   *
   *****************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2013, Intel Corp.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions, and the following disclaimer,
   *    without modification.
   * 2. Redistributions in binary form must reproduce at minimum a disclaimer
   *    substantially similar to the "NO WARRANTY" disclaimer below
   *    ("Disclaimer") and any redistribution must be conditioned upon
   *    including a substantially similar Disclaimer requirement for further
   *    binary redistribution.
   * 3. Neither the names of the above-listed copyright holders nor the names
   *    of any contributors may be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * NO WARRANTY
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGES.
   */
  
  
  #include "aslcompiler.h"
  #include "aslcompiler.y.h"
  #include "acparser.h"
  #include "amlcode.h"
  #include "acnamesp.h"
  #include "acdispat.h"
  
  
  #define _COMPONENT          ACPI_COMPILER
          ACPI_MODULE_NAME    ("asllookup")
  
  /* Local prototypes */
  
  static ACPI_STATUS
  LkIsObjectUsed (
      ACPI_HANDLE             ObjHandle,
      UINT32                  Level,
      void                    *Context,
      void                    **ReturnValue);
  
  static ACPI_PARSE_OBJECT *
  LkGetNameOp (
      ACPI_PARSE_OBJECT       *Op);
  
  
  /*******************************************************************************
   *
   * FUNCTION:    LkFindUnreferencedObjects
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Namespace walk to find objects that are not referenced in any
   *              way. Must be called after the namespace has been cross
   *              referenced.
   *
   ******************************************************************************/
  
  void
  LkFindUnreferencedObjects (
      void)
  {
  
      /* Walk entire namespace from the supplied root */
  
      (void) AcpiNsWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
                  ACPI_UINT32_MAX, FALSE, LkIsObjectUsed, NULL,
                  NULL, NULL);
  }
  
  
  /*******************************************************************************
   *
   * FUNCTION:    LkIsObjectUsed
   *
   * PARAMETERS:  ACPI_WALK_CALLBACK
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Check for an unreferenced namespace object and emit a warning.
   *              We have to be careful, because some types and names are
   *              typically or always unreferenced, we don't want to issue
   *              excessive warnings. Note: Names that are declared within a
   *              control method are temporary, so we always issue a remark
   *              if they are not referenced.
   *
   ******************************************************************************/
  
  static ACPI_STATUS
  LkIsObjectUsed (
      ACPI_HANDLE             ObjHandle,
      UINT32                  Level,
      void                    *Context,
      void                    **ReturnValue)
  {
      ACPI_NAMESPACE_NODE     *Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);
      ACPI_NAMESPACE_NODE     *Next;
  
  
      /* Referenced flag is set during the namespace xref */
  
      if (Node->Flags & ANOBJ_IS_REFERENCED)
      {
          return (AE_OK);
      }
  
      if (!Node->Op)
      {
          return (AE_OK);
      }
  
      /* These types are typically never directly referenced, ignore them */
  
      switch (Node->Type)
      {
      case ACPI_TYPE_DEVICE:
      case ACPI_TYPE_PROCESSOR:
      case ACPI_TYPE_POWER:
      case ACPI_TYPE_THERMAL:
      case ACPI_TYPE_LOCAL_RESOURCE:
  
          return (AE_OK);
  
      default:
  
          break;
      }
  
      /* Determine if the name is within a control method */
  
      Next = Node->Parent;
      while (Next)
      {
          if (Next->Type == ACPI_TYPE_METHOD)
          {
              /*
               * Name is within a method, therefore it is temporary.
               * Issue a remark even if it is a reserved name (starts
               * with an underscore).
               */
              sprintf (MsgBuffer, "Name is within method [%4.4s]",
                  Next->Name.Ascii);
              AslError (ASL_REMARK, ASL_MSG_NOT_REFERENCED,
                  LkGetNameOp (Node->Op), MsgBuffer);
              return (AE_OK);
          }
  
          Next = Next->Parent;
      }
  
      /* The name is not within a control method */
  
      /*
       * Ignore names that start with an underscore. These are the reserved
       * ACPI names and are typically not referenced since they are meant
       * to be called by the host OS.
       */
      if (Node->Name.Ascii[0] == '_')
      {
          return (AE_OK);
      }
  
      /*
       * What remains is an unresolved user name that is not within a method.
       * However, the object could be referenced via another table, so issue
       * the warning at level 2.
       */
      AslError (ASL_WARNING2, ASL_MSG_NOT_REFERENCED,
          LkGetNameOp (Node->Op), NULL);
      return (AE_OK);
  }
  
  
  /*******************************************************************************
   *
   * FUNCTION:    LkGetNameOp
   *
   * PARAMETERS:  Op              - Current Op
   *
   * RETURN:      NameOp associated with the input op
   *
   * DESCRIPTION: Find the name declaration op associated with the operator
   *
   ******************************************************************************/
  
  static ACPI_PARSE_OBJECT *
  LkGetNameOp (
      ACPI_PARSE_OBJECT       *Op)
  {
      const ACPI_OPCODE_INFO  *OpInfo;
      ACPI_PARSE_OBJECT       *NameOp = Op;
  
  
      OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
  
  
      /* Get the NamePath from the appropriate place */
  
      if (OpInfo->Flags & AML_NAMED)
      {
          /* For nearly all NAMED operators, the name reference is the first child */
  
          NameOp = Op->Asl.Child;
          if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
          {
              /*
               * ALIAS is the only oddball opcode, the name declaration
               * (alias name) is the second operand
               */
              NameOp = Op->Asl.Child->Asl.Next;
          }
      }
      else if (OpInfo->Flags & AML_CREATE)
      {
          /* Name must appear as the last parameter */
  
          NameOp = Op->Asl.Child;
          while (!(NameOp->Asl.CompileFlags & NODE_IS_NAME_DECLARATION))
          {
              NameOp = NameOp->Asl.Next;
          }
      }
  
      return (NameOp);
  }
  