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 *

 * Module Name: aslanalyze.c - check for semantic errors

 *

 *****************************************************************************/

 *

 * 1. Copyright Notice

 *

 * Some or all of this work - Copyright (c) 1999 - 2010, 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.

 *

 *****************************************************************************/

#include "aslcompiler.y.h"

#include "acparser.h"

#include "amlcode.h"

        ACPI_MODULE_NAME    ("aslanalyze")

AnMapArgTypeToBtype (

    UINT32                  ArgType);

AnMapEtypeToBtype (

    UINT32                  Etype);

AnFormatBtype (

    char                    *Buffer,

    UINT32                  Btype);

AnGetBtype (

    ACPI_PARSE_OBJECT       *Op);

AnMapObjTypeToBtype (

    ACPI_PARSE_OBJECT       *Op);

AnLastStatementIsReturn (

    ACPI_PARSE_OBJECT       *Op);

AnCheckMethodReturnValue (

    ACPI_PARSE_OBJECT       *Op,

    const ACPI_OPCODE_INFO  *OpInfo,

    ACPI_PARSE_OBJECT       *ArgOp,

    UINT32                  RequiredBtypes,

    UINT32                  ThisNodeBtype);

AnIsInternalMethod (

    ACPI_PARSE_OBJECT       *Op);

AnGetInternalMethodReturnType (

    ACPI_PARSE_OBJECT       *Op);

AnIsResultUsed (

    ACPI_PARSE_OBJECT       *Op);

 *

 * FUNCTION:    AnIsInternalMethod

 *

 * PARAMETERS:  Op              - Current op

 *

 * RETURN:      Boolean

 *

 * DESCRIPTION: Check for an internal control method.

 *

 ******************************************************************************/

AnIsInternalMethod (

    ACPI_PARSE_OBJECT       *Op)

{

        (!ACPI_STRCMP (Op->Asl.ExternalName, "_OSI")))

    {

        return (TRUE);

    }

}

 *

 * FUNCTION:    AnGetInternalMethodReturnType

 *

 * PARAMETERS:  Op              - Current op

 *

 * RETURN:      Btype

 *

 * DESCRIPTION: Get the return type of an internal method

 *

 ******************************************************************************/

AnGetInternalMethodReturnType (

    ACPI_PARSE_OBJECT       *Op)

{

        (!ACPI_STRCMP (Op->Asl.ExternalName, "_OSI")))

    {

        return (ACPI_BTYPE_STRING);

    }

}

 *

 * FUNCTION:    AnMapArgTypeToBtype

 *

 * PARAMETERS:  ArgType      - The ARGI required type(s) for this argument,

 *                             from the opcode info table

 *

 * RETURN:      The corresponding Bit-encoded types

 *

 * DESCRIPTION: Convert an encoded ARGI required argument type code into a

 *              bitfield type code. Implements the implicit source conversion

 *              rules.

 *

 ******************************************************************************/

AnMapArgTypeToBtype (

    UINT32                  ArgType)

{

    {

        return (ACPI_BTYPE_OBJECTS_AND_REFS);

        return (ACPI_BTYPE_PACKAGE);

        return (ACPI_BTYPE_EVENT);

        return (ACPI_BTYPE_MUTEX);

        /*

         * DDBHandleObject := SuperName

         * ACPI_BTYPE_REFERENCE: Index reference as parameter of Load/Unload

         */

        return (ACPI_BTYPE_DDB_HANDLE | ACPI_BTYPE_REFERENCE);

    /*

     * Source conversion rules:

     * Integer, String, and Buffer are all interchangeable

     */

    case ARGI_INTEGER:

    case ARGI_STRING:

    case ARGI_BUFFER:

    case ARGI_BUFFER_OR_STRING:

    case ARGI_COMPUTEDATA:

        return (ACPI_BTYPE_COMPUTE_DATA);

        return (ACPI_BTYPE_INTEGER);

        return (ACPI_BTYPE_ALL_OBJECTS);

        return (ACPI_BTYPE_DEVICE_OBJECTS);

        return (ACPI_BTYPE_REFERENCE);

    case ARGI_FIXED_TARGET:

    case ARGI_SIMPLE_TARGET:

        return (ACPI_BTYPE_OBJECTS_AND_REFS);

         * Buffer, string, package or reference to a Op -

         * Used only by SizeOf operator

         */

        return (ACPI_BTYPE_STRING | ACPI_BTYPE_BUFFER |

            ACPI_BTYPE_PACKAGE | ACPI_BTYPE_REFERENCE);

        return (ACPI_BTYPE_STRING | ACPI_BTYPE_REFERENCE);

        return (ACPI_BTYPE_INTEGER |ACPI_BTYPE_STRING | ACPI_BTYPE_BUFFER |

            ACPI_BTYPE_PACKAGE | ACPI_BTYPE_REFERENCE | ACPI_BTYPE_DDB_HANDLE);

        break;

    }

}

 *

 * FUNCTION:    AnMapEtypeToBtype

 *

 * PARAMETERS:  Etype           - Encoded ACPI Type

 *

 * RETURN:      Btype corresponding to the Etype

 *

 * DESCRIPTION: Convert an encoded ACPI type to a bitfield type applying the

 *              operand conversion rules. In other words, returns the type(s)

 *              this Etype is implicitly converted to during interpretation.

 *

 ******************************************************************************/

AnMapEtypeToBtype (

    UINT32                  Etype)

{

    {

        return ACPI_BTYPE_OBJECTS_AND_REFS;

    }

    {

        /*

         * This switch statement implements the allowed operand conversion

         * rules as per the "ASL Data Types" section of the ACPI

         * specification.

         */

        switch (Etype)

        {

        case ACPI_TYPE_INTEGER:

            return (ACPI_BTYPE_COMPUTE_DATA | ACPI_BTYPE_DDB_HANDLE);

        case ACPI_TYPE_BUFFER:

            return (ACPI_BTYPE_COMPUTE_DATA);

            return (ACPI_BTYPE_PACKAGE);

            return (ACPI_BTYPE_COMPUTE_DATA | ACPI_BTYPE_FIELD_UNIT);

            return (ACPI_BTYPE_COMPUTE_DATA | ACPI_BTYPE_BUFFER_FIELD);

            return (ACPI_BTYPE_INTEGER | ACPI_BTYPE_DDB_HANDLE);

            return (1 << (Etype - 1));

        }

    }

    {

    case ACPI_TYPE_LOCAL_REGION_FIELD:

    case ACPI_TYPE_LOCAL_BANK_FIELD:

    case ACPI_TYPE_LOCAL_INDEX_FIELD:

    case ACPI_TYPE_LOCAL_RESOURCE_FIELD:

        printf ("Unhandled encoded type: %X\n", Etype);

        return (0);

    }

}

 *

 * FUNCTION:    AnFormatBtype

 *

 * PARAMETERS:  Btype               - Bitfield of ACPI types

 *              Buffer              - Where to put the ascii string

 *

 * RETURN:      None.

 *

 * DESCRIPTION: Convert a Btype to a string of ACPI types

 *

 ******************************************************************************/

AnFormatBtype (

    char                    *Buffer,

    UINT32                  Btype)

{

    UINT32                  Type;

    BOOLEAN                 First = TRUE;

    {

        strcat (Buffer, "NoReturnValue");

        return;

    }

    {

        if (Btype & 0x00000001)

        {

            if (!First)

            {

                strcat (Buffer, "|");

            }

            First = FALSE;

            strcat (Buffer, AcpiUtGetTypeName (Type));

        }

        Btype >>= 1;

    }

    {

        if (!First)

        {

            strcat (Buffer, "|");

        }

        First = FALSE;

        strcat (Buffer, "Reference");

    }

    if (Btype & 0x00000001)

    {

        if (!First)

        {

            strcat (Buffer, "|");

        }

        First = FALSE;

        strcat (Buffer, "Resource");

    }

}

 *

 * FUNCTION:    AnGetBtype

 *

 * PARAMETERS:  Op          - Parse node whose type will be returned.

 *

 * RETURN:      The Btype associated with the Op.

 *

 * DESCRIPTION: Get the (bitfield) ACPI type associated with the parse node.

 *              Handles the case where the node is a name or method call and

 *              the actual type must be obtained from the namespace node.

 *

 ******************************************************************************/

AnGetBtype (

    ACPI_PARSE_OBJECT       *Op)

{

    ACPI_NAMESPACE_NODE     *Node;

    ACPI_PARSE_OBJECT       *ReferencedNode;

    UINT32                  ThisNodeBtype = 0;

        (Op->Asl.ParseOpcode == PARSEOP_NAMESTRING)  ||

        (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))

    {

        Node = Op->Asl.Node;

        if (!Node)

        {

            DbgPrint (ASL_DEBUG_OUTPUT,

                "No attached Nsnode: [%s] at line %u name [%s], ignoring typecheck\n",

                Op->Asl.ParseOpName, Op->Asl.LineNumber,

                Op->Asl.ExternalName);

            return ACPI_UINT32_MAX;

        }

        if (!ThisNodeBtype)

        {

            AslError (ASL_ERROR, ASL_MSG_COMPILER_INTERNAL, Op,

                "could not map type");

        }

         * Since it was a named reference, enable the

         * reference bit also

         */

        ThisNodeBtype |= ACPI_BTYPE_REFERENCE;

        {

            ReferencedNode = Node->Op;

            if (!ReferencedNode)

            {

                /* Check for an internal method */

                {

                    return (AnGetInternalMethodReturnType (Op));

                }

                    "null Op pointer");

                return ACPI_UINT32_MAX;

            }

            {

                ThisNodeBtype = ReferencedNode->Asl.AcpiBtype;

            }

            else

            {

                return (ACPI_UINT32_MAX -1);

            }

        }

    }

    else

    {

        ThisNodeBtype = Op->Asl.AcpiBtype;

    }

}

 *

 * FUNCTION:    AnMapObjTypeToBtype

 *

 * PARAMETERS:  Op              - A parse node

 *

 * RETURN:      A Btype

 *

 * DESCRIPTION: Map object to the associated "Btype"

 *

 ******************************************************************************/

AnMapObjTypeToBtype (

    ACPI_PARSE_OBJECT       *Op)

{

    {

    case PARSEOP_OBJECTTYPE_BFF:        /* "BuffFieldObj" */

        return (ACPI_BTYPE_BUFFER_FIELD);

        return (ACPI_BTYPE_BUFFER);

        return (ACPI_BTYPE_DDB_HANDLE);

        return (ACPI_BTYPE_DEVICE);

        return (ACPI_BTYPE_EVENT);

        return (ACPI_BTYPE_FIELD_UNIT);

        return (ACPI_BTYPE_INTEGER);

        return (ACPI_BTYPE_METHOD);

        return (ACPI_BTYPE_MUTEX);

        return (ACPI_BTYPE_REGION);

        return (ACPI_BTYPE_PACKAGE);

        return (ACPI_BTYPE_POWER);

        return (ACPI_BTYPE_STRING);

        return (ACPI_BTYPE_THERMAL);

        return (ACPI_BTYPE_OBJECTS_AND_REFS);

        return (0);

    }

}

 *

 * FUNCTION:    AnMethodAnalysisWalkBegin

 *

 * PARAMETERS:  ASL_WALK_CALLBACK

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Descending callback for the analysis walk. Check methods for:

 *              1) Initialized local variables

 *              2) Valid arguments

 *              3) Return types

 *

 ******************************************************************************/

AnMethodAnalysisWalkBegin (

    ACPI_PARSE_OBJECT       *Op,

    UINT32                  Level,

    void                    *Context)

{

    ASL_ANALYSIS_WALK_INFO  *WalkInfo = (ASL_ANALYSIS_WALK_INFO *) Context;

    ASL_METHOD_INFO         *MethodInfo = WalkInfo->MethodStack;

    ACPI_PARSE_OBJECT       *Next;

    UINT32                  RegisterNumber;

    UINT32                  i;

    char                    LocalName[] = "Local0";

    char                    ArgName[] = "Arg0";

    ACPI_PARSE_OBJECT       *ArgNode;

    ACPI_PARSE_OBJECT       *NextType;

    ACPI_PARSE_OBJECT       *NextParamType;

    UINT8                   ActualArgs = 0;

    {

    case PARSEOP_METHOD:

        MethodInfo->Next = WalkInfo->MethodStack;

        MethodInfo->Op = Op;

        MethodInfo->NumArguments = (UINT8)

            (((UINT8) Next->Asl.Value.Integer) & 0x07);

        Next = Next->Asl.Next;

        ArgNode = Next;

        while (NextType)

        {

            /* Get and map each of the ReturnTypes */

            NextType->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;

            NextType = NextType->Asl.Next;

        }

        while (NextType)

        {

            if (NextType->Asl.ParseOpcode == PARSEOP_DEFAULT_ARG)

            {

                NextParamType = NextType->Asl.Child;

                while (NextParamType)

                {

                    MethodInfo->ValidArgTypes[ActualArgs] |= AnMapObjTypeToBtype (NextParamType);

                    NextParamType->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;

                    NextParamType = NextParamType->Asl.Next;

                }

            }

            else

            {

                MethodInfo->ValidArgTypes[ActualArgs] =

                    AnMapObjTypeToBtype (NextType);

                NextType->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;

                ActualArgs++;

            }

        }

            (MethodInfo->NumArguments != ActualArgs))

        {

            /* error: Param list did not match number of args */

        }

        {

            MethodInfo->NumArguments = ActualArgs;

            ArgNode->Asl.Value.Integer |= ActualArgs;

        }

         * Actual arguments are initialized at method entry.

         * All other ArgX "registers" can be used as locals, so we

         * track their initialization.

         */

        for (i = 0; i < MethodInfo->NumArguments; i++)

        {

            MethodInfo->ArgInitialized[i] = TRUE;

        }

        break;

           (Op->Asl.Node == MethodInfo->Op->Asl.Node))

        {

            AslError (ASL_REMARK, ASL_MSG_RECURSION, Op, Op->Asl.ExternalName);

        }

        break;

    case PARSEOP_LOCAL1:

    case PARSEOP_LOCAL2:

    case PARSEOP_LOCAL3:

    case PARSEOP_LOCAL4:

    case PARSEOP_LOCAL5:

    case PARSEOP_LOCAL6:

    case PARSEOP_LOCAL7:

        {

            /*

             * Local was used outside a control method, or there was an error

             * in the method declaration.

             */

            AslError (ASL_REMARK, ASL_MSG_LOCAL_OUTSIDE_METHOD, Op, Op->Asl.ExternalName);

            return (AE_ERROR);

        }

         * If the local is being used as a target, mark the local

         * initialized

         */

        if (Op->Asl.CompileFlags & NODE_IS_TARGET)

        {

            MethodInfo->LocalInitialized[RegisterNumber] = TRUE;

        }

         * Otherwise, this is a reference, check if the local

         * has been previously initialized.

         *

         * The only operator that accepts an uninitialized value is ObjectType()

         */

        else if ((!MethodInfo->LocalInitialized[RegisterNumber]) &&

                 (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_OBJECTTYPE))

        {

            LocalName[strlen (LocalName) -1] = (char) (RegisterNumber + 0x30);

            AslError (ASL_ERROR, ASL_MSG_LOCAL_INIT, Op, LocalName);

        }

        break;

    case PARSEOP_ARG1:

    case PARSEOP_ARG2:

    case PARSEOP_ARG3:

    case PARSEOP_ARG4:

    case PARSEOP_ARG5:

    case PARSEOP_ARG6:

        {

            /*

             * Arg was used outside a control method, or there was an error

             * in the method declaration.

             */

            AslError (ASL_REMARK, ASL_MSG_LOCAL_OUTSIDE_METHOD, Op, Op->Asl.ExternalName);

            return (AE_ERROR);

        }

        ArgName[strlen (ArgName) -1] = (char) (RegisterNumber + 0x30);

         * If the Arg is being used as a target, mark the local

         * initialized

         */

        if (Op->Asl.CompileFlags & NODE_IS_TARGET)

        {

            MethodInfo->ArgInitialized[RegisterNumber] = TRUE;

        }

         * Otherwise, this is a reference, check if the Arg

         * has been previously initialized.

         *

         * The only operator that accepts an uninitialized value is ObjectType()

         */

        else if ((!MethodInfo->ArgInitialized[RegisterNumber]) &&

                 (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_OBJECTTYPE))

        {

            AslError (ASL_ERROR, ASL_MSG_ARG_INIT, Op, ArgName);

        }

        {

            AslError (ASL_REMARK, ASL_MSG_NOT_PARAMETER, Op, ArgName);

        }

        break;

        {

            /*

             * Probably was an error in the method declaration,

             * no additional error here

             */

            ACPI_WARNING ((AE_INFO, "%p, No parent method", Op));

            return (AE_ERROR);

        }

            (Op->Asl.Child->Asl.ParseOpcode != PARSEOP_DEFAULT_ARG))

        {

            MethodInfo->NumReturnWithValue++;

        }

        else

        {

            MethodInfo->NumReturnNoValue++;

        }

        break;

    case PARSEOP_CONTINUE:

        while (Next)

        {

            if (Next->Asl.ParseOpcode == PARSEOP_WHILE)

            {

                break;

            }

            Next = Next->Asl.Parent;

        }

        {

            AslError (ASL_ERROR, ASL_MSG_NO_WHILE, Op, NULL);

        }

        break;

            (Op->Asl.Child->Asl.Value.Integer > ACPI_UINT8_MAX))

        {

            AslError (ASL_ERROR, ASL_MSG_INVALID_TIME, Op, NULL);

        }

        break;

    case PARSEOP_EVENT:

    case PARSEOP_MUTEX:

    case PARSEOP_OPERATIONREGION:

    case PARSEOP_POWERRESOURCE:

    case PARSEOP_PROCESSOR:

    case PARSEOP_THERMALZONE:

         * The first operand is a name to be created in the namespace.

         * Check against the reserved list.

         */

        i = ApCheckForPredefinedName (Op, Op->Asl.NameSeg);

        if (i < ACPI_VALID_RESERVED_NAME_MAX)

        {

            AslError (ASL_ERROR, ASL_MSG_RESERVED_USE, Op, Op->Asl.ExternalName);

        }

        break;

        {

            Next = Op->Asl.Child->Asl.Next;

            if (Next->Asl.ParseOpcode == PARSEOP_STRING_LITERAL)

            {

                /*

                 * _HID is a string, all characters must be alphanumeric.

                 * One of the things we want to catch here is the use of

                 * a leading asterisk in the string.

                 */

                for (i = 0; Next->Asl.Value.String[i]; i++)

                {

                    if (!isalnum ((int) Next->Asl.Value.String[i]))

                    {

                        AslError (ASL_ERROR, ASL_MSG_ALPHANUMERIC_STRING,

                            Next, Next->Asl.Value.String);

                        break;

                    }

                }

            }

        }

        break;

        break;

    }

}

 *

 * FUNCTION:    AnLastStatementIsReturn

 *

 * PARAMETERS:  Op            - A method parse node

 *

 * RETURN:      TRUE if last statement is an ASL RETURN. False otherwise

 *

 * DESCRIPTION: Walk down the list of top level statements within a method

 *              to find the last one. Check if that last statement is in

 *              fact a RETURN statement.

 *

 ******************************************************************************/

AnLastStatementIsReturn (

    ACPI_PARSE_OBJECT       *Op)

{

    ACPI_PARSE_OBJECT       *Next;

     * Check if last statement is a return

     */

    Next = ASL_GET_CHILD_NODE (Op);

    while (Next)

    {

        if ((!Next->Asl.Next) &&

            (Next->Asl.ParseOpcode == PARSEOP_RETURN))

        {

            return TRUE;

        }

    }

}

 *

 * FUNCTION:    AnMethodAnalysisWalkEnd

 *

 * PARAMETERS:  ASL_WALK_CALLBACK

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Ascending callback for analysis walk. Complete method

 *              return analysis.

 *

 ******************************************************************************/

AnMethodAnalysisWalkEnd (

    ACPI_PARSE_OBJECT       *Op,

    UINT32                  Level,

    void                    *Context)

{

    ASL_ANALYSIS_WALK_INFO  *WalkInfo = (ASL_ANALYSIS_WALK_INFO *) Context;

    ASL_METHOD_INFO         *MethodInfo = WalkInfo->MethodStack;

    {

    case PARSEOP_METHOD:

    case PARSEOP_RETURN:

        if (!MethodInfo)

        {

            printf ("No method info for method! [%s]\n", Op->Asl.Namepath);

            AslError (ASL_ERROR, ASL_MSG_COMPILER_INTERNAL, Op,

                "No method info for this method");

            CmCleanupAndExit ();

            return (AE_AML_INTERNAL);

        }

        break;

        break;

    }

    {

    case PARSEOP_METHOD:

         * Check if there is no return statement at the end of the

         * method AND we can actually get there -- i.e., the execution

         * of the method can possibly terminate without a return statement.

         */

        if ((!AnLastStatementIsReturn (Op)) &&

            (!(Op->Asl.CompileFlags & NODE_HAS_NO_EXIT)))

        {

            /*

             * No return statement, and execution can possibly exit

             * via this path. This is equivalent to Return ()

             */

            MethodInfo->NumReturnNoValue++;

        }

         * Check for case where some return statements have a return value

         * and some do not. Exit without a return statement is a return with

         * no value

         */

        if (MethodInfo->NumReturnNoValue &&

            MethodInfo->NumReturnWithValue)

        {

            AslError (ASL_WARNING, ASL_MSG_RETURN_TYPES, Op,

                Op->Asl.ExternalName);

        }

         * If there are any RETURN() statements with no value, or there is a