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

 *

 * Module Name: aslmethod.c - Control method analysis walk

 *

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

/*

 * Copyright (C) 2000 - 2018, 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"

#define _COMPONENT          ACPI_COMPILER

        ACPI_MODULE_NAME    ("aslmethod")

/* Local prototypes */

static void

MtCheckNamedObjectInMethod (

    ACPI_PARSE_OBJECT       *Op,

    ASL_METHOD_INFO         *MethodInfo);

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

 *

 * FUNCTION:    MtMethodAnalysisWalkBegin

 *

 * 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

MtMethodAnalysisWalkBegin (

    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;

    /* Build cross-reference output file if requested */

    if (Gbl_CrossReferenceOutput)

    {

        OtXrefWalkPart1 (Op, Level, MethodInfo);

    }

    switch (Op->Asl.ParseOpcode)

    {

    case PARSEOP_METHOD:

        TotalMethods++;

        /* Create and init method info */

        MethodInfo = UtLocalCalloc (sizeof (ASL_METHOD_INFO));

        MethodInfo->Next = WalkInfo->MethodStack;

        MethodInfo->Op = Op;

        WalkInfo->MethodStack = MethodInfo;

        /*

         * Special handling for _PSx methods. Dependency rules (same scope):

         *

         * 1) _PS0 - One of these must exist: _PS1, _PS2, _PS3

         * 2) _PS1/_PS2/_PS3: A _PS0 must exist

         */

        if (ACPI_COMPARE_NAME (METHOD_NAME__PS0, Op->Asl.NameSeg))

        {

            /* For _PS0, one of _PS1/_PS2/_PS3 must exist */

            if ((!ApFindNameInScope (METHOD_NAME__PS1, Op)) &&

                (!ApFindNameInScope (METHOD_NAME__PS2, Op)) &&

                (!ApFindNameInScope (METHOD_NAME__PS3, Op)))

            {

                AslError (ASL_WARNING, ASL_MSG_MISSING_DEPENDENCY, Op,

                    "_PS0 requires one of _PS1/_PS2/_PS3 in same scope");

            }

        }

        else if (

            ACPI_COMPARE_NAME (METHOD_NAME__PS1, Op->Asl.NameSeg) ||

            ACPI_COMPARE_NAME (METHOD_NAME__PS2, Op->Asl.NameSeg) ||

            ACPI_COMPARE_NAME (METHOD_NAME__PS3, Op->Asl.NameSeg))

        {

            /* For _PS1/_PS2/_PS3, a _PS0 must exist */

            if (!ApFindNameInScope (METHOD_NAME__PS0, Op))

            {

                sprintf (MsgBuffer,

                    "%4.4s requires _PS0 in same scope", Op->Asl.NameSeg);

                AslError (ASL_WARNING, ASL_MSG_MISSING_DEPENDENCY, Op,

                    MsgBuffer);

            }

        }

        /* Get the name node */

        Next = Op->Asl.Child;

        /* Get the NumArguments node */

        Next = Next->Asl.Next;

        MethodInfo->NumArguments = (UINT8)

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

        /* Get the SerializeRule and SyncLevel nodes, ignored here */

        Next = Next->Asl.Next;

        MethodInfo->ShouldBeSerialized = (UINT8) Next->Asl.Value.Integer;

        Next = Next->Asl.Next;

        ArgNode = Next;

        /* Get the ReturnType node */

        Next = Next->Asl.Next;

        NextType = Next->Asl.Child;

        while (NextType)

        {

            /* Get and map each of the ReturnTypes */

            MethodInfo->ValidReturnTypes |= AnMapObjTypeToBtype (NextType);

            NextType->Asl.ParseOpcode = PARSEOP_DEFAULT_ARG;

            NextType = NextType->Asl.Next;

        }

        /* Get the ParameterType node */

        Next = Next->Asl.Next;

        NextType = Next->Asl.Child;

        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++;

            }

            NextType = NextType->Asl.Next;

        }

        if ((MethodInfo->NumArguments) &&

            (MethodInfo->NumArguments != ActualArgs))

        {

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

        }

        /* Allow numarguments == 0 for Function() */

        if ((!MethodInfo->NumArguments) && (ActualArgs))

        {

            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;

    case PARSEOP_METHODCALL:

        /* Check for a recursive method call */

        if (MethodInfo &&

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

        {

            if (MethodInfo->CreatesNamedObjects)

            {

                /*

                 * This is an error, as it will fail at runtime on all ACPI

                 * implementations. Any named object declarations will be

                 * executed twice, causing failure the second time. Note,

                 * this is independent of whether the method is declared

                 * Serialized, because the same thread is attempting to

                 * reenter the method, and this will always succeed.

                 */

                AslDualParseOpError (ASL_ERROR, ASL_MSG_ILLEGAL_RECURSION, Op,

                    Op->Asl.Value.String, ASL_MSG_FOUND_HERE, MethodInfo->Op,

                    MethodInfo->Op->Asl.ExternalName);

            }

            else

            {

                /* Method does not create objects, issue a remark */

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

            }

        }

        break;

    case PARSEOP_LOCAL0:

    case PARSEOP_LOCAL1:

    case PARSEOP_LOCAL2:

    case PARSEOP_LOCAL3:

    case PARSEOP_LOCAL4:

    case PARSEOP_LOCAL5:

    case PARSEOP_LOCAL6:

    case PARSEOP_LOCAL7:

        if (!MethodInfo)

        {

            /*

             * 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);

        }

        RegisterNumber = (Op->Asl.AmlOpcode & 0x0007);

        /*

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

         * initialized

         */

        if (Op->Asl.CompileFlags & OP_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_ARG0:

    case PARSEOP_ARG1:

    case PARSEOP_ARG2:

    case PARSEOP_ARG3:

    case PARSEOP_ARG4:

    case PARSEOP_ARG5:

    case PARSEOP_ARG6:

        if (!MethodInfo)

        {

            /*

             * 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);

        }

        RegisterNumber = (Op->Asl.AmlOpcode & 0x000F) - 8;

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

        /*

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

         * initialized

         */

        if (Op->Asl.CompileFlags & OP_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);

        }

        /* Flag this arg if it is not a "real" argument to the method */

        if (RegisterNumber >= MethodInfo->NumArguments)

        {

            AslError (ASL_REMARK, ASL_MSG_NOT_PARAMETER, Op, ArgName);

        }

        break;

    case PARSEOP_RETURN:

        if (!MethodInfo)

        {

            /*

             * Probably was an error in the method declaration,

             * no additional error here

             */

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

            return (AE_ERROR);

        }

        /*

         * A child indicates a possible return value. A simple Return or

         * Return() is marked with OP_IS_NULL_RETURN by the parser so

         * that it is not counted as a "real" return-with-value, although

         * the AML code that is actually emitted is Return(0). The AML

         * definition of Return has a required parameter, so we are

         * forced to convert a null return to Return(0).

         */

        if ((Op->Asl.Child) &&

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

            (!(Op->Asl.Child->Asl.CompileFlags & OP_IS_NULL_RETURN)))

        {

            MethodInfo->NumReturnWithValue++;

        }

        else

        {

            MethodInfo->NumReturnNoValue++;

        }

        break;

    case PARSEOP_BREAK:

    case PARSEOP_CONTINUE:

        Next = Op->Asl.Parent;

        while (Next)

        {

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

            {

                break;

            }

            Next = Next->Asl.Parent;

        }

        if (!Next)

        {

            AslError (ASL_ERROR, ASL_MSG_NO_WHILE, Op, NULL);

        }

        break;

    case PARSEOP_STALL:

        /* We can range check if the argument is an integer */

        if ((Op->Asl.Child->Asl.ParseOpcode == PARSEOP_INTEGER) &&

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

        {

            AslError (ASL_ERROR, ASL_MSG_INVALID_TIME, Op, NULL);

        }

        break;

    case PARSEOP_DEVICE:

        if (!ApFindNameInDeviceTree (METHOD_NAME__HID, Op) &&

            !ApFindNameInDeviceTree (METHOD_NAME__ADR, Op))

        {

            AslError (ASL_WARNING, ASL_MSG_MISSING_DEPENDENCY, Op,

                "Device object requires a _HID or _ADR in same scope");

        }

        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;

    case PARSEOP_NAME:

        /* Typecheck any predefined names statically defined with Name() */

        ApCheckForPredefinedObject (Op, Op->Asl.NameSeg);

        /* Special typechecking for _HID */

        if (!strcmp (METHOD_NAME__HID, Op->Asl.NameSeg))

        {

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

            AnCheckId (Next, ASL_TYPE_HID);

        }

        /* Special typechecking for _CID */

        else if (!strcmp (METHOD_NAME__CID, Op->Asl.NameSeg))

        {

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

            if ((Next->Asl.ParseOpcode == PARSEOP_PACKAGE) ||

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

            {

                Next = Next->Asl.Child;

                while (Next)

                {

                    AnCheckId (Next, ASL_TYPE_CID);

                    Next = Next->Asl.Next;

                }

            }

            else

            {

                AnCheckId (Next, ASL_TYPE_CID);

            }

        }

        break;

    default:

        break;

    }

    /* Check for named object creation within a non-serialized method */

    MtCheckNamedObjectInMethod (Op, MethodInfo);

    return (AE_OK);

}

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

 *

 * FUNCTION:    MtCheckNamedObjectInMethod

 *

 * PARAMETERS:  Op                  - Current parser op

 *              MethodInfo          - Info for method being parsed

 *

 * RETURN:      None

 *

 * DESCRIPTION: Detect if a non-serialized method is creating a named object,

 *              which could possibly cause problems if two threads execute

 *              the method concurrently. Emit a remark in this case.

 *

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

static void

MtCheckNamedObjectInMethod (

    ACPI_PARSE_OBJECT       *Op,

    ASL_METHOD_INFO         *MethodInfo)

{

    const ACPI_OPCODE_INFO  *OpInfo;

    /* We don't care about actual method declarations or scopes */

    if ((Op->Asl.AmlOpcode == AML_METHOD_OP) ||

        (Op->Asl.AmlOpcode == AML_SCOPE_OP))

    {

        return;

    }

    /* Determine if we are creating a named object within a method */

    if (!MethodInfo)

    {

        return;

    }

    OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);

    if (OpInfo->Class == AML_CLASS_NAMED_OBJECT)

    {

        /*

         * 1) Mark the method as a method that creates named objects.

         *

         * 2) If the method is non-serialized, emit a remark that the method

         * should be serialized.

         *

         * Reason: If a thread blocks within the method for any reason, and

         * another thread enters the method, the method will fail because

         * an attempt will be made to create the same object twice.

         */

        MethodInfo->CreatesNamedObjects = TRUE;

        if (!MethodInfo->ShouldBeSerialized)

        {

            AslError (ASL_REMARK, ASL_MSG_SERIALIZED_REQUIRED, MethodInfo->Op,

                "due to creation of named objects within");

            /* Emit message only ONCE per method */

            MethodInfo->ShouldBeSerialized = TRUE;

        }

    }

}

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

 *

 * FUNCTION:    MtMethodAnalysisWalkEnd

 *

 * PARAMETERS:  ASL_WALK_CALLBACK

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Ascending callback for analysis walk. Complete method

 *              return analysis.

 *

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

ACPI_STATUS

MtMethodAnalysisWalkEnd (

    ACPI_PARSE_OBJECT       *Op,

    UINT32                  Level,

    void                    *Context)

{

    ASL_ANALYSIS_WALK_INFO  *WalkInfo = (ASL_ANALYSIS_WALK_INFO *) Context;

    ASL_METHOD_INFO         *MethodInfo = WalkInfo->MethodStack;

    switch (Op->Asl.ParseOpcode)

    {

    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;

    default:

        break;

    }

    switch (Op->Asl.ParseOpcode)

    {

    case PARSEOP_METHOD:

        WalkInfo->MethodStack = MethodInfo->Next;

        /*

         * 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 & OP_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 |= OP_METHOD_SOME_NO_RETVAL;

            }

            else

            {

                Op->Asl.CompileFlags |= OP_METHOD_NO_RETVAL;

            }

        }

        /*

         * Check predefined method names for correct return behavior

         * and correct number of arguments. Also, some special checks

         * For GPE and _REG methods.

         */

        if (ApCheckForPredefinedMethod (Op, MethodInfo))

        {

            /* Special check for two names like _L01 and _E01 in same scope */

            ApCheckForGpeNameConflict (Op);

            /*

             * Special check for _REG: Must have an operation region definition

             * within the same scope!

             */

            ApCheckRegMethod (Op);

        }

        ACPI_FREE (MethodInfo);

        break;

    case PARSEOP_NAME:

         /* Special check for two names like _L01 and _E01 in same scope */

        ApCheckForGpeNameConflict (Op);

        break;

    case PARSEOP_RETURN:

        /*

         * If the parent is a predefined method name, attempt to typecheck

         * the return value. Only static types can be validated.

         */

        ApCheckPredefinedReturnValue (Op, MethodInfo);

        /*

         * The parent block does not "exit" and continue execution -- the

         * method is terminated here with the Return() statement.

         */

        Op->Asl.Parent->Asl.CompileFlags |= OP_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 preceding 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 & OP_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 |= OP_IF_HAS_NO_EXIT;

        }

        break;

    case PARSEOP_ELSE:

        if ((Op->Asl.CompileFlags & OP_HAS_NO_EXIT) &&

            (Op->Asl.CompileFlags & OP_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 |= OP_HAS_NO_EXIT;

        }

        break;

    default:

        if ((Op->Asl.CompileFlags & OP_HAS_NO_EXIT) &&

            (Op->Asl.Parent))

        {

            /* If this node has no exit, then the parent has no exit either */

            Op->Asl.Parent->Asl.CompileFlags |= OP_HAS_NO_EXIT;

        }

        break;

    }

    return (AE_OK);

}