text: /******************************************************************************
   *
   * Module Name: asllookup- Namespace lookup functions
   *
   *****************************************************************************/
  
  /******************************************************************************
   *
   * 1. Copyright Notice
   *
   * Some or all of this work - Copyright (c) 1999 - 2020, Intel Corp.
   * All rights reserved.
   *
   * 2. License
   *
   * 2.1. This is your license from Intel Corp. under its intellectual property
   * rights. You may have additional license terms from the party that provided
   * you this software, covering your right to use that party's intellectual
   * property rights.
   *
   * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
   * copy of the source code appearing in this file ("Covered Code") an
   * irrevocable, perpetual, worldwide license under Intel's copyrights in the
   * base code distributed originally by Intel ("Original Intel Code") to copy,
   * make derivatives, distribute, use and display any portion of the Covered
   * Code in any form, with the right to sublicense such rights; and
   *
   * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
   * license (with the right to sublicense), under only those claims of Intel
   * patents that are infringed by the Original Intel Code, to make, use, sell,
   * offer to sell, and import the Covered Code and derivative works thereof
   * solely to the minimum extent necessary to exercise the above copyright
   * license, and in no event shall the patent license extend to any additions
   * to or modifications of the Original Intel Code. No other license or right
   * is granted directly or by implication, estoppel or otherwise;
   *
   * The above copyright and patent license is granted only if the following
   * conditions are met:
   *
   * 3. Conditions
   *
   * 3.1. Redistribution of Source with Rights to Further Distribute Source.
   * Redistribution of source code of any substantial portion of the Covered
   * Code or modification with rights to further distribute source must include
   * the above Copyright Notice, the above License, this list of Conditions,
   * and the following Disclaimer and Export Compliance provision. In addition,
   * Licensee must cause all Covered Code to which Licensee contributes to
   * contain a file documenting the changes Licensee made to create that Covered
   * Code and the date of any change. Licensee must include in that file the
   * documentation of any changes made by any predecessor Licensee. Licensee
   * must include a prominent statement that the modification is derived,
   * directly or indirectly, from Original Intel Code.
   *
   * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
   * Redistribution of source code of any substantial portion of the Covered
   * Code or modification without rights to further distribute source must
   * include the following Disclaimer and Export Compliance provision in the
   * documentation and/or other materials provided with distribution. In
   * addition, Licensee may not authorize further sublicense of source of any
   * portion of the Covered Code, and must include terms to the effect that the
   * license from Licensee to its licensee is limited to the intellectual
   * property embodied in the software Licensee provides to its licensee, and
   * not to intellectual property embodied in modifications its licensee may
   * make.
   *
   * 3.3. Redistribution of Executable. Redistribution in executable form of any
   * substantial portion of the Covered Code or modification must reproduce the
   * above Copyright Notice, and the following Disclaimer and Export Compliance
   * provision in the documentation and/or other materials provided with the
   * distribution.
   *
   * 3.4. Intel retains all right, title, and interest in and to the Original
   * Intel Code.
   *
   * 3.5. Neither the name Intel nor any other trademark owned or controlled by
   * Intel shall be used in advertising or otherwise to promote the sale, use or
   * other dealings in products derived from or relating to the Covered Code
   * without prior written authorization from Intel.
   *
   * 4. Disclaimer and Export Compliance
   *
   * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
   * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
   * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
   * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
   * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
   * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
   * PARTICULAR PURPOSE.
   *
   * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
   * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
   * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
   * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
   * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
   * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
   * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
   * LIMITED REMEDY.
   *
   * 4.3. Licensee shall not export, either directly or indirectly, any of this
   * software or system incorporating such software without first obtaining any
   * required license or other approval from the U. S. Department of Commerce or
   * any other agency or department of the United States Government. In the
   * event Licensee exports any such software from the United States or
   * re-exports any such software from a foreign destination, Licensee shall
   * ensure that the distribution and export/re-export of the software is in
   * compliance with all laws, regulations, orders, or other restrictions of the
   * U.S. Export Administration Regulations. Licensee agrees that neither it nor
   * any of its subsidiaries will export/re-export any technical data, process,
   * software, or service, directly or indirectly, to any country for which the
   * United States government or any agency thereof requires an export license,
   * other governmental approval, or letter of assurance, without first obtaining
   * such license, approval or letter.
   *
   *****************************************************************************
   *
   * Alternatively, you may choose to be licensed under the terms of the
   * following license:
   *
   * 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.
   *
   * 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 MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * 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 DAMAGE.
   *
   * Alternatively, you may choose to be licensed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   *****************************************************************************/
  
  #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;
      ASL_METHOD_LOCAL        *MethodLocals;
      ASL_METHOD_LOCAL        *MethodArgs;
      UINT32                  i;
  
  
      if (Node->Type == ACPI_TYPE_METHOD)
      {
          if (!Node->Op || !Node->MethodLocals)
          {
              return (AE_OK);
          }
  
          MethodLocals = (ASL_METHOD_LOCAL *) Node->MethodLocals;
          MethodArgs = (ASL_METHOD_LOCAL *) Node->MethodArgs;
  
          /*
           * Analysis of LocalX variables
           */
          for (i = 0; i < ACPI_METHOD_NUM_LOCALS; i++)
          {
              /* Warn for Locals that are set but never referenced */
  
              if ((MethodLocals[i].Flags & ASL_LOCAL_INITIALIZED) &&
                  (!(MethodLocals[i].Flags & ASL_LOCAL_REFERENCED)))
              {
                  sprintf (AslGbl_MsgBuffer, "Local%u", i);
                  AslError (ASL_WARNING, ASL_MSG_LOCAL_NOT_USED,
                      MethodLocals[i].Op, AslGbl_MsgBuffer);
              }
          }
  
          /*
           * Analysis of ArgX variables (standard method arguments,
           * and remaining unused ArgX can also be used as locals)
           */
          for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
          {
              if (MethodArgs[i].Flags & ASL_ARG_IS_LOCAL)
              {
                  /* Warn if ArgX is being used as a local, but not referenced */
  
                  if ((MethodArgs[i].Flags & ASL_ARG_INITIALIZED) &&
                      (!(MethodArgs[i].Flags & ASL_ARG_REFERENCED)))
                  {
                      sprintf (AslGbl_MsgBuffer, "Arg%u", i);
                      AslError (ASL_WARNING, ASL_MSG_ARG_AS_LOCAL_NOT_USED,
                          MethodArgs[i].Op, AslGbl_MsgBuffer);
                  }
              }
              else
              {
                  /*
                   * Remark if a normal method ArgX is not referenced.
                   * We ignore the predefined methods since often, not
                   * all arguments are needed or used.
                   */
                  if ((Node->Name.Ascii[0] != '_') &&
                      (!(MethodArgs[i].Flags & ASL_ARG_REFERENCED)))
                  {
                      sprintf (AslGbl_MsgBuffer, "Arg%u", i);
                      AslError (ASL_REMARK, ASL_MSG_ARG_NOT_USED,
                          MethodArgs[i].Op, AslGbl_MsgBuffer);
                  }
              }
          }
      }
  
      /* 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:
      case ACPI_TYPE_LOCAL_RESOURCE_FIELD: /* Names assigned to descriptor elements */
  
          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 (AslGbl_MsgBuffer, "Name [%4.4s] is within a method [%4.4s]",
                  Node->Name.Ascii, Next->Name.Ascii);
              AslError (ASL_REMARK, ASL_MSG_NOT_REFERENCED,
                  LkGetNameOp (Node->Op), AslGbl_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 & OP_IS_NAME_DECLARATION))
          {
              NameOp = NameOp->Asl.Next;
          }
      }
  
      return (NameOp);
  }
  