aslanalyze.c

acpi tools for linux include acpiexec and acpixtract

        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
         * control path that allows the method to exit without a return value,
         * we mark the method as a method that does not return a value. This
         * knowledge can be used to check method invocations that expect a
         * returned value.
         */
        if (MethodInfo->NumReturnNoValue)
        {
            if (MethodInfo->NumReturnWithValue)
            {
                Op->Asl.CompileFlags |= NODE_METHOD_SOME_NO_RETVAL;
            }
            else
            {
                Op->Asl.CompileFlags |= NODE_METHOD_NO_RETVAL;
            }
        }

        /*
         * Check predefined method names for correct return behavior
         * and correct number of arguments
         */
        AnCheckForReservedMethod (Op, MethodInfo);
        ACPI_FREE (MethodInfo);
        break;


    case PARSEOP_RETURN:

        /*
         * The parent block does not "exit" and continue execution -- the
         * method is terminated here with the Return() statement.
         */
        Op->Asl.Parent->Asl.CompileFlags |= NODE_HAS_NO_EXIT;

        /* Used in the "typing" pass later */

        Op->Asl.ParentMethod = MethodInfo->Op;

        /*
         * If there is a peer node after the return statement, then this
         * node is unreachable code -- i.e., it won't be executed because of
         * the preceeding Return() statement.
         */
        if (Op->Asl.Next)
        {
            AslError (ASL_WARNING, ASL_MSG_UNREACHABLE_CODE, Op->Asl.Next, NULL);
        }
        break;


    case PARSEOP_IF:

        if ((Op->Asl.CompileFlags & NODE_HAS_NO_EXIT) &&
            (Op->Asl.Next) &&
            (Op->Asl.Next->Asl.ParseOpcode == PARSEOP_ELSE))
        {
            /*
             * This IF has a corresponding ELSE. The IF block has no exit,
             * (it contains an unconditional Return)
             * mark the ELSE block to remember this fact.
             */
            Op->Asl.Next->Asl.CompileFlags |= NODE_IF_HAS_NO_EXIT;
        }
        break;


    case PARSEOP_ELSE:

        if ((Op->Asl.CompileFlags & NODE_HAS_NO_EXIT) &&
            (Op->Asl.CompileFlags & NODE_IF_HAS_NO_EXIT))
        {
            /*
             * This ELSE block has no exit and the corresponding IF block
             * has no exit either. Therefore, the parent node has no exit.
             */
            Op->Asl.Parent->Asl.CompileFlags |= NODE_HAS_NO_EXIT;
        }
        break;


    default:

        if ((Op->Asl.CompileFlags & NODE_HAS_NO_EXIT) &&
            (Op->Asl.Parent))
        {
            /* If this node has no exit, then the parent has no exit either */

            Op->Asl.Parent->Asl.CompileFlags |= NODE_HAS_NO_EXIT;
        }
        break;
    }

    return AE_OK;
}


/*******************************************************************************
 *
 * FUNCTION:    AnMethodTypingWalkBegin
 *
 * PARAMETERS:  ASL_WALK_CALLBACK
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Descending callback for the typing walk.
 *
 ******************************************************************************/

ACPI_STATUS
AnMethodTypingWalkBegin (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{

    return AE_OK;
}


/*******************************************************************************
 *
 * FUNCTION:    AnMethodTypingWalkEnd
 *
 * PARAMETERS:  ASL_WALK_CALLBACK
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Ascending callback for typing walk. Complete the method
 *              return analysis. Check methods for:
 *              1) Initialized local variables
 *              2) Valid arguments
 *              3) Return types
 *
 ******************************************************************************/

ACPI_STATUS
AnMethodTypingWalkEnd (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{
    UINT32                  ThisNodeBtype;


    switch (Op->Asl.ParseOpcode)
    {
    case PARSEOP_METHOD:

        Op->Asl.CompileFlags |= NODE_METHOD_TYPED;
        break;

    case PARSEOP_RETURN:

        if ((Op->Asl.Child) &&
            (Op->Asl.Child->Asl.ParseOpcode != PARSEOP_DEFAULT_ARG))
        {
            ThisNodeBtype = AnGetBtype (Op->Asl.Child);

            if ((Op->Asl.Child->Asl.ParseOpcode == PARSEOP_METHODCALL) &&
                (ThisNodeBtype == (ACPI_UINT32_MAX -1)))
            {
                /*
                 * The called method is untyped at this time (typically a
                 * forward reference).
                 *
                 * Check for a recursive method call first.
                 */
                if (Op->Asl.ParentMethod != Op->Asl.Child->Asl.Node->Op)
                {
                    /* We must type the method here */

                    TrWalkParseTree (Op->Asl.Child->Asl.Node->Op,
                        ASL_WALK_VISIT_TWICE, AnMethodTypingWalkBegin,
                        AnMethodTypingWalkEnd, NULL);

                    ThisNodeBtype = AnGetBtype (Op->Asl.Child);
                }
            }

            /* Returns a value, save the value type */

            if (Op->Asl.ParentMethod)
            {
                Op->Asl.ParentMethod->Asl.AcpiBtype |= ThisNodeBtype;
            }
        }
        break;

    default:
        break;
    }

    return AE_OK;
}


/*******************************************************************************
 *
 * FUNCTION:    AnCheckMethodReturnValue
 *
 * PARAMETERS:  Op                  - Parent
 *              OpInfo              - Parent info
 *              ArgOp               - Method invocation op
 *              RequiredBtypes      - What caller requires
 *              ThisNodeBtype       - What this node returns (if anything)
 *
 * RETURN:      None
 *
 * DESCRIPTION: Check a method invocation for 1) A return value and if it does
 *              in fact return a value, 2) check the type of the return value.
 *
 ******************************************************************************/

static void
AnCheckMethodReturnValue (
    ACPI_PARSE_OBJECT       *Op,
    const ACPI_OPCODE_INFO  *OpInfo,
    ACPI_PARSE_OBJECT       *ArgOp,
    UINT32                  RequiredBtypes,
    UINT32                  ThisNodeBtype)
{
    ACPI_PARSE_OBJECT       *OwningOp;
    ACPI_NAMESPACE_NODE     *Node;


    Node = ArgOp->Asl.Node;


    /* Examine the parent op of this method */

    OwningOp = Node->Op;
    if (OwningOp->Asl.CompileFlags & NODE_METHOD_NO_RETVAL)
    {
        /* Method NEVER returns a value */

        AslError (ASL_ERROR, ASL_MSG_NO_RETVAL, Op, Op->Asl.ExternalName);
    }
    else if (OwningOp->Asl.CompileFlags & NODE_METHOD_SOME_NO_RETVAL)
    {
        /* Method SOMETIMES returns a value, SOMETIMES not */

        AslError (ASL_WARNING, ASL_MSG_SOME_NO_RETVAL, Op, Op->Asl.ExternalName);
    }
    else if (!(ThisNodeBtype & RequiredBtypes))
    {
        /* Method returns a value, but the type is wrong */

        AnFormatBtype (StringBuffer, ThisNodeBtype);
        AnFormatBtype (StringBuffer2, RequiredBtypes);


        /*
         * The case where the method does not return any value at all
         * was already handled in the namespace cross reference
         * -- Only issue an error if the method in fact returns a value,
         * but it is of the wrong type
         */
        if (ThisNodeBtype != 0)
        {
            sprintf (MsgBuffer,
                "Method returns [%s], %s operator requires [%s]",
                StringBuffer, OpInfo->Name, StringBuffer2);

            AslError (ASL_ERROR, ASL_MSG_INVALID_TYPE, ArgOp, MsgBuffer);
        }
    }
}


/*******************************************************************************
 *
 * FUNCTION:    AnOperandTypecheckWalkBegin
 *
 * 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
 *
 ******************************************************************************/

ACPI_STATUS
AnOperandTypecheckWalkBegin (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{

    return AE_OK;
}


/*******************************************************************************
 *
 * FUNCTION:    AnOperandTypecheckWalkEnd
 *
 * PARAMETERS:  ASL_WALK_CALLBACK
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Ascending callback for analysis walk. Complete method
 *              return analysis.
 *
 ******************************************************************************/

ACPI_STATUS
AnOperandTypecheckWalkEnd (
    ACPI_PARSE_OBJECT       *Op,
    UINT32                  Level,
    void                    *Context)
{
    const ACPI_OPCODE_INFO  *OpInfo;
    UINT32                  RuntimeArgTypes;
    UINT32                  RuntimeArgTypes2;
    UINT32                  RequiredBtypes;
    UINT32                  ThisNodeBtype;
    UINT32                  CommonBtypes;
    UINT32                  OpcodeClass;
    ACPI_PARSE_OBJECT       *ArgOp;
    UINT32                  ArgType;


    switch (Op->Asl.AmlOpcode)
    {
    case AML_RAW_DATA_BYTE:
    case AML_RAW_DATA_WORD:
    case AML_RAW_DATA_DWORD:
    case AML_RAW_DATA_QWORD:
    case AML_RAW_DATA_BUFFER:
    case AML_RAW_DATA_CHAIN:
    case AML_PACKAGE_LENGTH:
    case AML_UNASSIGNED_OPCODE:
    case AML_DEFAULT_ARG_OP:

        /* Ignore the internal (compiler-only) AML opcodes */

        return (AE_OK);

    default:
        break;
    }

    OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
    if (!OpInfo)
    {
        return (AE_OK);
    }

    ArgOp           = Op->Asl.Child;
    RuntimeArgTypes = OpInfo->RuntimeArgs;
    OpcodeClass     = OpInfo->Class;


    /*
     * Special case for control opcodes IF/RETURN/WHILE since they
     * have no runtime arg list (at this time)
     */
    switch (Op->Asl.AmlOpcode)
    {
    case AML_IF_OP:
    case AML_WHILE_OP:
    case AML_RETURN_OP:

        if (ArgOp->Asl.ParseOpcode == PARSEOP_METHODCALL)
        {
            /* Check for an internal method */

            if (AnIsInternalMethod (ArgOp))
            {
                return (AE_OK);
            }

            /* The lone arg is a method call, check it */

            RequiredBtypes = AnMapArgTypeToBtype (ARGI_INTEGER);
            if (Op->Asl.AmlOpcode == AML_RETURN_OP)
            {
                RequiredBtypes = 0xFFFFFFFF;
            }

            ThisNodeBtype = AnGetBtype (ArgOp);
            if (ThisNodeBtype == ACPI_UINT32_MAX)
            {
                return (AE_OK);
            }
            AnCheckMethodReturnValue (Op, OpInfo, ArgOp,
                RequiredBtypes, ThisNodeBtype);
        }
        return (AE_OK);

    default:
        break;
    }

    /* Ignore the non-executable opcodes */

    if (RuntimeArgTypes == ARGI_INVALID_OPCODE)
    {
        return (AE_OK);
    }

    switch (OpcodeClass)
    {
    case AML_CLASS_EXECUTE:
    case AML_CLASS_CREATE:
    case AML_CLASS_CONTROL:
    case AML_CLASS_RETURN_VALUE:

        /* TBD: Change class or fix typechecking for these */

        if ((Op->Asl.AmlOpcode == AML_BUFFER_OP)        ||
            (Op->Asl.AmlOpcode == AML_PACKAGE_OP)       ||
            (Op->Asl.AmlOpcode == AML_VAR_PACKAGE_OP))
        {
            break;
        }