/******************************************************************************
 *
 * Module Name: dmextern - Support for External() ASL statements
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2019, 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 "acpi.h"
#include "accommon.h"
#include "amlcode.h"
#include "acnamesp.h"
#include "acdisasm.h"
#include "aslcompiler.h"
#include <stdio.h>
#include <errno.h>


/*
 * This module is used for application-level code (iASL disassembler) only.
 *
 * It contains the code to create and emit any necessary External() ASL
 * statements for the module being disassembled.
 */
#define _COMPONENT          ACPI_CA_DISASSEMBLER
        ACPI_MODULE_NAME    ("dmextern")


/*
 * This table maps ACPI_OBJECT_TYPEs to the corresponding ASL
 * ObjectTypeKeyword. Used to generate typed external declarations
 */
static const char           *AcpiGbl_DmTypeNames[] =
{
    /* 00 */ ", UnknownObj",        /* Type ANY */
    /* 01 */ ", IntObj",
    /* 02 */ ", StrObj",
    /* 03 */ ", BuffObj",
    /* 04 */ ", PkgObj",
    /* 05 */ ", FieldUnitObj",
    /* 06 */ ", DeviceObj",
    /* 07 */ ", EventObj",
    /* 08 */ ", MethodObj",
    /* 09 */ ", MutexObj",
    /* 10 */ ", OpRegionObj",
    /* 11 */ ", PowerResObj",
    /* 12 */ ", ProcessorObj",
    /* 13 */ ", ThermalZoneObj",
    /* 14 */ ", BuffFieldObj",
    /* 15 */ ", DDBHandleObj",
    /* 16 */ "",                    /* Debug object */
    /* 17 */ ", FieldUnitObj",
    /* 18 */ ", FieldUnitObj",
    /* 19 */ ", FieldUnitObj"
};

#define METHOD_SEPARATORS           " \t,()\n"

static const char          *ExternalConflictMessage =
    "    // Conflicts with a later declaration";


/* Local prototypes */

static const char *
AcpiDmGetObjectTypeName (
    ACPI_OBJECT_TYPE        Type);

static char *
AcpiDmNormalizeParentPrefix (
    ACPI_PARSE_OBJECT       *Op,
    char                    *Path);

static ACPI_STATUS
AcpiDmGetExternalAndInternalPath (
    ACPI_NAMESPACE_NODE     *Node,
    char                    **ExternalPath,
    char                    **InternalPath);

static ACPI_STATUS
AcpiDmRemoveRootPrefix (
    char                    **Path);

static void
AcpiDmAddPathToExternalList (
    char                    *Path,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags);

static ACPI_STATUS
AcpiDmCreateNewExternal (
    char                    *ExternalPath,
    char                    *InternalPath,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags);

static void
AcpiDmCheckForExternalConflict (
    char                    *Path);

static ACPI_STATUS
AcpiDmResolveExternal (
    char                    *Path,
    UINT8                   Type,
    ACPI_NAMESPACE_NODE     **Node);


static void
AcpiDmConflictingDeclaration (
    char                    *Path);


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmGetObjectTypeName
 *
 * PARAMETERS:  Type                - An ACPI_OBJECT_TYPE
 *
 * RETURN:      Pointer to a string
 *
 * DESCRIPTION: Map an object type to the ASL object type string.
 *
 ******************************************************************************/

static const char *
AcpiDmGetObjectTypeName (
    ACPI_OBJECT_TYPE        Type)
{

    if (Type == ACPI_TYPE_LOCAL_SCOPE)
    {
        Type = ACPI_TYPE_DEVICE;
    }
    else if (Type > ACPI_TYPE_LOCAL_INDEX_FIELD)
    {
        return ("");
    }

    return (AcpiGbl_DmTypeNames[Type]);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmNormalizeParentPrefix
 *
 * PARAMETERS:  Op                  - Parse op
 *              Path                - Path with parent prefix
 *
 * RETURN:      The full pathname to the object (from the namespace root)
 *
 * DESCRIPTION: Returns the full pathname of a path with parent prefix
 *              The caller must free the fullpath returned.
 *
 ******************************************************************************/

static char *
AcpiDmNormalizeParentPrefix (
    ACPI_PARSE_OBJECT       *Op,
    char                    *Path)
{
    ACPI_NAMESPACE_NODE     *Node;
    char                    *Fullpath;
    char                    *ParentPath;
    ACPI_SIZE               Length;
    UINT32                  Index = 0;


    if (!Op)
    {
        return (NULL);
    }

    /* Search upwards in the parse tree until we reach the next namespace node */

    Op = Op->Common.Parent;
    while (Op)
    {
        if (Op->Common.Node)
        {
            break;
        }

        Op = Op->Common.Parent;
    }

    if (!Op)
    {
        return (NULL);
    }

    /*
     * Find the actual parent node for the reference:
     * Remove all carat prefixes from the input path.
     * There may be multiple parent prefixes (For example, ^^^M000)
     */
    Node = Op->Common.Node;
    while (Node && (*Path == (UINT8) AML_PARENT_PREFIX))
    {
        Node = Node->Parent;
        Path++;
    }

    if (!Node)
    {
        return (NULL);
    }

    /* Get the full pathname for the parent node */

    ParentPath = AcpiNsGetExternalPathname (Node);
    if (!ParentPath)
    {
        return (NULL);
    }

    Length = (strlen (ParentPath) + strlen (Path) + 1);
    if (ParentPath[1])
    {
        /*
         * If ParentPath is not just a simple '\', increment the length
         * for the required dot separator (ParentPath.Path)
         */
        Length++;

        /* For External() statements, we do not want a leading '\' */

        if (*ParentPath == AML_ROOT_PREFIX)
        {
            Index = 1;
        }
    }

    Fullpath = ACPI_ALLOCATE_ZEROED (Length);
    if (!Fullpath)
    {
        goto Cleanup;
    }

    /*
     * Concatenate parent fullpath and path. For example,
     * parent fullpath "\_SB_", Path "^INIT", Fullpath "\_SB_.INIT"
     *
     * Copy the parent path
     */
    strcpy (Fullpath, &ParentPath[Index]);

    /*
     * Add dot separator
     * (don't need dot if parent fullpath is a single backslash)
     */
    if (ParentPath[1])
    {
        strcat (Fullpath, ".");
    }

    /* Copy child path (carat parent prefix(es) were skipped above) */

    strcat (Fullpath, Path);

Cleanup:
    ACPI_FREE (ParentPath);
    return (Fullpath);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddToExternalFileList
 *
 * PARAMETERS:  PathList            - Single path or list separated by comma
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add external files to global list
 *
 ******************************************************************************/

ACPI_STATUS
AcpiDmAddToExternalFileList (
    char                    *Pathname)
{
    ACPI_EXTERNAL_FILE      *ExternalFile;
    char                    *LocalPathname;


    if (!Pathname)
    {
        return (AE_OK);
    }

    LocalPathname = ACPI_ALLOCATE (strlen (Pathname) + 1);
    if (!LocalPathname)
    {
        return (AE_NO_MEMORY);
    }

    ExternalFile = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EXTERNAL_FILE));
    if (!ExternalFile)
    {
        ACPI_FREE (LocalPathname);
        return (AE_NO_MEMORY);
    }

    /* Take a copy of the file pathname */

    strcpy (LocalPathname, Pathname);
    ExternalFile->Path = LocalPathname;

    if (AcpiGbl_ExternalFileList)
    {
        ExternalFile->Next = AcpiGbl_ExternalFileList;
    }

    AcpiGbl_ExternalFileList = ExternalFile;
    return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmClearExternalFileList
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Clear the external file list
 *
 ******************************************************************************/

void
AcpiDmClearExternalFileList (
    void)
{
    ACPI_EXTERNAL_FILE      *NextExternal;


    while (AcpiGbl_ExternalFileList)
    {
        NextExternal = AcpiGbl_ExternalFileList->Next;
        ACPI_FREE (AcpiGbl_ExternalFileList->Path);
        ACPI_FREE (AcpiGbl_ExternalFileList);
        AcpiGbl_ExternalFileList = NextExternal;
    }
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmGetExternalsFromFile
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Process the optional external reference file.
 *
 * Each line in the file should be of the form:
 *      External (<Method namepath>, MethodObj, <ArgCount>)
 *
 * Example:
 *      External (_SB_.PCI0.XHC_.PS0X, MethodObj, 4)
 *
 ******************************************************************************/

void
AcpiDmGetExternalsFromFile (
    void)
{
    FILE                    *ExternalRefFile;
    char                    *Token;
    char                    *MethodName;
    UINT32                  ArgCount;
    UINT32                  ImportCount = 0;


    if (!AslGbl_ExternalRefFilename)
    {
        return;
    }

    /* Open the file */

    ExternalRefFile = fopen (AslGbl_ExternalRefFilename, "r");
    if (!ExternalRefFile)
    {
        fprintf (stderr, "Could not open external reference file \"%s\"\n",
            AslGbl_ExternalRefFilename);
        AslAbort ();
        return;
    }

    /* Each line defines a method */

    while (fgets (AslGbl_StringBuffer, ASL_STRING_BUFFER_SIZE, ExternalRefFile))
    {
        Token = strtok (AslGbl_StringBuffer, METHOD_SEPARATORS);   /* "External" */
        if (!Token)
        {
            continue;
        }

        if (strcmp (Token, "External"))
        {
            continue;
        }

        MethodName = strtok (NULL, METHOD_SEPARATORS);      /* Method namepath */
        if (!MethodName)
        {
            continue;
        }

        Token = strtok (NULL, METHOD_SEPARATORS);           /* "MethodObj" */
        if (!Token)
        {
            continue;
        }

        if (strcmp (Token, "MethodObj"))
        {
            continue;
        }

        Token = strtok (NULL, METHOD_SEPARATORS);           /* Arg count */
        if (!Token)
        {
            continue;
        }

        /* Convert arg count string to an integer */

        errno = 0;
        ArgCount = strtoul (Token, NULL, 0);
        if (errno)
        {
            fprintf (stderr, "Invalid argument count (%s)\n", Token);
            continue;
        }

        if (ArgCount > 7)
        {
            fprintf (stderr, "Invalid argument count (%u)\n", ArgCount);
            continue;
        }

        /* Add this external to the global list */

        AcpiOsPrintf ("%s: Importing method external (%u arguments) %s\n",
            AslGbl_ExternalRefFilename, ArgCount, MethodName);

        AcpiDmAddPathToExternalList (MethodName, ACPI_TYPE_METHOD,
            ArgCount, (ACPI_EXT_RESOLVED_REFERENCE | ACPI_EXT_ORIGIN_FROM_FILE));
        ImportCount++;
    }

    if (!ImportCount)
    {
        fprintf (stderr,
            "Did not find any external methods in reference file \"%s\"\n",
            AslGbl_ExternalRefFilename);
    }
    else
    {
        /* Add the external(s) to the namespace */

        AcpiDmAddExternalListToNamespace ();

        AcpiOsPrintf ("%s: Imported %u external method definitions\n",
            AslGbl_ExternalRefFilename, ImportCount);
    }

    fclose (ExternalRefFile);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddOpToExternalList
 *
 * PARAMETERS:  Op                  - Current parser Op
 *              Path                - Internal (AML) path to the object
 *              Type                - ACPI object type to be added
 *              Value               - Arg count if adding a Method object
 *              Flags               - To be passed to the external object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Insert a new name into the global list of Externals which
 *              will in turn be later emitted as an External() declaration
 *              in the disassembled output.
 *
 *              This function handles the most common case where the referenced
 *              name is simply not found in the constructed namespace.
 *
 ******************************************************************************/

void
AcpiDmAddOpToExternalList (
    ACPI_PARSE_OBJECT       *Op,
    char                    *Path,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags)
{
    char                    *ExternalPath;
    char                    *InternalPath = Path;
    char                    *Temp;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (DmAddOpToExternalList);


    if (!Path)
    {
        return_VOID;
    }

    /* Remove a root backslash if present */

    if ((*Path == AML_ROOT_PREFIX) && (Path[1]))
    {
        Path++;
    }

    /* Externalize the pathname */

    Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, Path,
        NULL, &ExternalPath);
    if (ACPI_FAILURE (Status))
    {
        return_VOID;
    }

    /*
     * Get the full pathname from the root if "Path" has one or more
     * parent prefixes (^). Note: path will not contain a leading '\'.
     */
    if (*Path == (UINT8) AML_PARENT_PREFIX)
    {
        Temp = AcpiDmNormalizeParentPrefix (Op, ExternalPath);

        /* Set new external path */

        ACPI_FREE (ExternalPath);
        ExternalPath = Temp;
        if (!Temp)
        {
            return_VOID;
        }

        /* Create the new internal pathname */

        Flags |= ACPI_EXT_INTERNAL_PATH_ALLOCATED;
        Status = AcpiNsInternalizeName (ExternalPath, &InternalPath);
        if (ACPI_FAILURE (Status))
        {
            ACPI_FREE (ExternalPath);
            return_VOID;
        }
    }

    /* Create the new External() declaration node */

    Status = AcpiDmCreateNewExternal (ExternalPath, InternalPath,
        Type, Value, Flags);
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (ExternalPath);
        if (Flags & ACPI_EXT_INTERNAL_PATH_ALLOCATED)
        {
            ACPI_FREE (InternalPath);
        }
    }

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmGetExternalAndInternalPath
 *
 * PARAMETERS:  Node                - Namespace node for object to be added
 *              ExternalPath        - Will contain the external path of the node
 *              InternalPath        - Will contain the internal path of the node
 *
 * RETURN:      None
 *
 * DESCRIPTION: Get the External and Internal path from the given node.
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiDmGetExternalAndInternalPath (
    ACPI_NAMESPACE_NODE     *Node,
    char                    **ExternalPath,
    char                    **InternalPath)
{
    ACPI_STATUS             Status;


    if (!Node)
    {
        return (AE_BAD_PARAMETER);
    }

    /* Get the full external and internal pathnames to the node */

    *ExternalPath = AcpiNsGetExternalPathname (Node);
    if (!*ExternalPath)
    {
        return (AE_BAD_PATHNAME);
    }

    Status = AcpiNsInternalizeName (*ExternalPath, InternalPath);
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (*ExternalPath);
        return (Status);
    }

    return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmRemoveRootPrefix
 *
 * PARAMETERS:  Path                - Remove Root prefix from this Path
 *
 * RETURN:      None
 *
 * DESCRIPTION: Remove the root prefix character '\' from Path.
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiDmRemoveRootPrefix (
    char                    **Path)
{
    char                    *InputPath = *Path;


    if ((*InputPath == AML_ROOT_PREFIX) && (InputPath[1]))
    {
        if (!memmove(InputPath, InputPath+1, strlen(InputPath)))
        {
            return (AE_ERROR);
        }

        *Path = InputPath;
    }

    return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddNodeToExternalList
 *
 * PARAMETERS:  Node                - Namespace node for object to be added
 *              Type                - ACPI object type to be added
 *              Value               - Arg count if adding a Method object
 *              Flags               - To be passed to the external object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Insert a new name into the global list of Externals which
 *              will in turn be later emitted as an External() declaration
 *              in the disassembled output.
 *
 *              This function handles the case where the referenced name has
 *              been found in the namespace, but the name originated in a
 *              table other than the one that is being disassembled (such
 *              as a table that is added via the iASL -e option).
 *
 ******************************************************************************/

void
AcpiDmAddNodeToExternalList (
    ACPI_NAMESPACE_NODE     *Node,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags)
{
    char                    *ExternalPath;
    char                    *InternalPath;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (DmAddNodeToExternalList);

    /* Get the full external and internal pathnames to the node */

    Status = AcpiDmGetExternalAndInternalPath (Node, &ExternalPath, &InternalPath);
    if (ACPI_FAILURE (Status))
    {
        return_VOID;
    }

    /* Remove the root backslash */

    Status = AcpiDmRemoveRootPrefix (&ExternalPath);
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (ExternalPath);
        ACPI_FREE (InternalPath);
        return_VOID;
    }

    /* Create the new External() declaration node */

    Status = AcpiDmCreateNewExternal (ExternalPath, InternalPath, Type,
        Value, (Flags | ACPI_EXT_INTERNAL_PATH_ALLOCATED));
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (ExternalPath);
        ACPI_FREE (InternalPath);
    }

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddPathToExternalList
 *
 * PARAMETERS:  Path                - External name of the object to be added
 *              Type                - ACPI object type to be added
 *              Value               - Arg count if adding a Method object
 *              Flags               - To be passed to the external object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Insert a new name into the global list of Externals which
 *              will in turn be later emitted as an External() declaration
 *              in the disassembled output.
 *
 *              This function currently is used to add externals via a
 *              reference file (via the -fe iASL option).
 *
 ******************************************************************************/

static void
AcpiDmAddPathToExternalList (
    char                    *Path,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags)
{
    char                    *InternalPath;
    char                    *ExternalPath;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (DmAddPathToExternalList);


    if (!Path)
    {
        return_VOID;
    }

    /* Remove a root backslash if present */

    if ((*Path == AML_ROOT_PREFIX) && (Path[1]))
    {
        Path++;
    }

    /* Create the internal and external pathnames */

    Status = AcpiNsInternalizeName (Path, &InternalPath);
    if (ACPI_FAILURE (Status))
    {
        return_VOID;
    }

    Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, InternalPath,
        NULL, &ExternalPath);
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (InternalPath);
        return_VOID;
    }

    /* Create the new External() declaration node */

    Status = AcpiDmCreateNewExternal (ExternalPath, InternalPath,
        Type, Value, (Flags | ACPI_EXT_INTERNAL_PATH_ALLOCATED));
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (ExternalPath);
        ACPI_FREE (InternalPath);
    }

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmCreateNewExternal
 *
 * PARAMETERS:  ExternalPath        - External path to the object
 *              InternalPath        - Internal (AML) path to the object
 *              Type                - ACPI object type to be added
 *              Value               - Arg count if adding a Method object
 *              Flags               - To be passed to the external object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Common low-level function to insert a new name into the global
 *              list of Externals which will in turn be later emitted as
 *              External() declarations in the disassembled output.
 *
 *              Note: The external name should not include a root prefix
 *              (backslash). We do not want External() statements to contain
 *              a leading '\', as this prevents duplicate external statements
 *              of the form:
 *
 *                  External (\ABCD)
 *                  External (ABCD)
 *
 *              This would cause a compile time error when the disassembled
 *              output file is recompiled.
 *
 *              There are two cases that are handled here. For both, we emit
 *              an External() statement:
 *              1) The name was simply not found in the namespace.
 *              2) The name was found, but it originated in a table other than
 *              the table that is being disassembled.
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiDmCreateNewExternal (
    char                    *ExternalPath,
    char                    *InternalPath,
    UINT8                   Type,
    UINT32                  Value,
    UINT16                  Flags)
{
    ACPI_EXTERNAL_LIST      *NewExternal;
    ACPI_EXTERNAL_LIST      *NextExternal;
    ACPI_EXTERNAL_LIST      *PrevExternal = NULL;


    ACPI_FUNCTION_TRACE (DmCreateNewExternal);


    /* Check all existing externals to ensure no duplicates */

    NextExternal = AcpiGbl_ExternalList;
    while (NextExternal)
    {
        /* Check for duplicates */

        if (!strcmp (ExternalPath, NextExternal->Path))
        {
            /*
             * If this external came from an External() opcode, we are
             * finished with this one. (No need to check any further).
             */
            if (NextExternal->Flags & ACPI_EXT_ORIGIN_FROM_OPCODE)
            {
                return_ACPI_STATUS (AE_ALREADY_EXISTS);
            }

            /* Allow upgrade of type from ANY */

            else if ((NextExternal->Type == ACPI_TYPE_ANY) &&
                (Type != ACPI_TYPE_ANY))
            {
                NextExternal->Type = Type;
            }

            /* Update the argument count as necessary */

            if (Value < NextExternal->Value)
            {
                NextExternal->Value = Value;
            }

            /* Update flags. */

            NextExternal->Flags |= Flags;
            NextExternal->Flags &= ~ACPI_EXT_INTERNAL_PATH_ALLOCATED;

            return_ACPI_STATUS (AE_ALREADY_EXISTS);
        }

        NextExternal = NextExternal->Next;
    }

    /* Allocate and init a new External() descriptor */

    NewExternal = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EXTERNAL_LIST));
    if (!NewExternal)
    {
        return_ACPI_STATUS (AE_NO_MEMORY);
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
        "Adding external reference node (%s) type [%s]\n",
        ExternalPath, AcpiUtGetTypeName (Type)));

    NewExternal->Flags = Flags;
    NewExternal->Value = Value;
    NewExternal->Path = ExternalPath;
    NewExternal->Type = Type;
    NewExternal->Length = (UINT16) strlen (ExternalPath);
    NewExternal->InternalPath = InternalPath;

    /* Link the new descriptor into the global list, alphabetically ordered */

    NextExternal = AcpiGbl_ExternalList;
    while (NextExternal)
    {
        if (AcpiUtStricmp (NewExternal->Path, NextExternal->Path) < 0)
        {
            if (PrevExternal)
            {
                PrevExternal->Next = NewExternal;
            }
            else
            {
                AcpiGbl_ExternalList = NewExternal;
            }

            NewExternal->Next = NextExternal;
            return_ACPI_STATUS (AE_OK);
        }

        PrevExternal = NextExternal;
        NextExternal = NextExternal->Next;
    }

    if (PrevExternal)
    {
        PrevExternal->Next = NewExternal;
    }
    else
    {
        AcpiGbl_ExternalList = NewExternal;
    }

    return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmResolveExternal
 *
 * PARAMETERS:  Path               - Path of the external
 *              Type               - Type of the external
 *              Node               - Input node for AcpiNsLookup
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Resolve the external within the namespace by AcpiNsLookup.
 *              If the returned node is an external and has the same type
 *              we assume that it was either an existing external or a
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiDmResolveExternal (
    char                    *Path,
    UINT8                   Type,
    ACPI_NAMESPACE_NODE     **Node)
{
    ACPI_STATUS             Status;


    Status = AcpiNsLookup (NULL, Path, Type,
        ACPI_IMODE_LOAD_PASS1,
        ACPI_NS_ERROR_IF_FOUND | ACPI_NS_EXTERNAL | ACPI_NS_DONT_OPEN_SCOPE,
        NULL, Node);

    if (!Node)
    {
        ACPI_EXCEPTION ((AE_INFO, Status,
            "while adding external to namespace [%s]", Path));
    }

    /* Note the asl code "external(a) external(a)" is acceptable ASL */

    else if ((*Node)->Type == Type &&
        (*Node)->Flags & ANOBJ_IS_EXTERNAL)
    {
        return (AE_OK);
    }
    else
    {
        ACPI_EXCEPTION ((AE_INFO, AE_ERROR,
            "[%s] has conflicting declarations", Path));
    }

    return (AE_ERROR);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmCreateSubobjectForExternal
 *
 * PARAMETERS:  Type                  - Type of the external
 *              Node                  - Namespace node from AcpiNsLookup
 *              ParamCount            - Value to be used for Method
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add one external to the namespace. Allows external to be
 *              "resolved".
 *
 ******************************************************************************/

void
AcpiDmCreateSubobjectForExternal (
    UINT8                   Type,
    ACPI_NAMESPACE_NODE     **Node,
    UINT32                  ParamCount)
{
    ACPI_OPERAND_OBJECT     *ObjDesc;


    switch (Type)
    {
    case ACPI_TYPE_METHOD:

        /* For methods, we need to save the argument count */

        ObjDesc = AcpiUtCreateInternalObject (ACPI_TYPE_METHOD);
        ObjDesc->Method.ParamCount = (UINT8) ParamCount;
        (*Node)->Object = ObjDesc;
        break;

    case ACPI_TYPE_REGION:

        /* Regions require a region sub-object */

        ObjDesc = AcpiUtCreateInternalObject (ACPI_TYPE_REGION);
        ObjDesc->Region.Node = *Node;
        (*Node)->Object = ObjDesc;
        break;

    default:

        break;
    }
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddOneExternalToNamespace
 *
 * PARAMETERS:  Path                   - External parse object
 *              Type                   - Type of parse object
 *              ParamCount             - External method parameter count
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add one external to the namespace by resolvign the external
 *              (by performing a namespace lookup) and annotating the resulting
 *              namespace node with the appropriate information if the type
 *              is ACPI_TYPE_REGION or ACPI_TYPE_METHOD.
 *
 ******************************************************************************/

void
AcpiDmAddOneExternalToNamespace (
    char                    *Path,
    UINT8                   Type,
    UINT32                  ParamCount)
{
    ACPI_STATUS             Status;
    ACPI_NAMESPACE_NODE     *Node;


    Status = AcpiDmResolveExternal (Path, Type, &Node);

    if (ACPI_FAILURE (Status))
    {
        return;
    }

    AcpiDmCreateSubobjectForExternal (Type, &Node, ParamCount);

}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmAddExternalListToNamespace
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add all externals within AcpiGbl_ExternalList to the namespace.
 *              Allows externals to be "resolved".
 *
 ******************************************************************************/

void
AcpiDmAddExternalListToNamespace (
    void)
{
    ACPI_EXTERNAL_LIST      *External = AcpiGbl_ExternalList;


    while (External)
    {
        AcpiDmAddOneExternalToNamespace (External->InternalPath,
            External->Type, External->Value);
        External = External->Next;
    }
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmGetUnresolvedExternalMethodCount
 *
 * PARAMETERS:  None
 *
 * RETURN:      The number of unresolved control method externals in the
 *              external list
 *
 * DESCRIPTION: Return the number of unresolved external methods that have been
 *              generated. If any unresolved control method externals have been
 *              found, we must re-parse the entire definition block with the new
 *              information (number of arguments for the methods.)
 *              This is limitation of AML, we don't know the number of arguments
 *              from the control method invocation itself.
 *
 *              Note: resolved external control methods are external control
 *              methods encoded with the AML_EXTERNAL_OP bytecode within the
 *              AML being disassembled.
 *
 ******************************************************************************/

UINT32
AcpiDmGetUnresolvedExternalMethodCount (
    void)
{
    ACPI_EXTERNAL_LIST      *External = AcpiGbl_ExternalList;
    UINT32                  Count = 0;


    while (External)
    {
        if (External->Type == ACPI_TYPE_METHOD &&
            !(External->Flags & ACPI_EXT_ORIGIN_FROM_OPCODE))
        {
            Count++;
        }

        External = External->Next;
    }

    return (Count);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmClearExternalList
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Free the entire External info list
 *
 ******************************************************************************/

void
AcpiDmClearExternalList (
    void)
{
    ACPI_EXTERNAL_LIST      *NextExternal;


    while (AcpiGbl_ExternalList)
    {
        NextExternal = AcpiGbl_ExternalList->Next;
        ACPI_FREE (AcpiGbl_ExternalList->Path);
        ACPI_FREE (AcpiGbl_ExternalList);
        AcpiGbl_ExternalList = NextExternal;
    }
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmEmitExternals
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Emit an External() ASL statement for each of the externals in
 *              the global external info list.
 *
 ******************************************************************************/

void
AcpiDmEmitExternals (
    void)
{
    ACPI_EXTERNAL_LIST      *NextExternal;


    if (!AcpiGbl_ExternalList)
    {
        return;
    }

    /*
     * Determine the number of control methods in the external list, and
     * also how many of those externals were resolved via the namespace.
     */
    NextExternal = AcpiGbl_ExternalList;
    while (NextExternal)
    {
        if (NextExternal->Type == ACPI_TYPE_METHOD)
        {
            AcpiGbl_NumExternalMethods++;
            if (NextExternal->Flags & ACPI_EXT_RESOLVED_REFERENCE)
            {
                AcpiGbl_ResolvedExternalMethods++;
            }
        }

        NextExternal = NextExternal->Next;
    }

    /* Check if any control methods were unresolved */

    AcpiDmUnresolvedWarning (1);

    if (AslGbl_ExternalRefFilename)
    {
        AcpiOsPrintf (
            "    /*\n     * External declarations were imported from\n"
            "     * a reference file -- %s\n     */\n\n",
            AslGbl_ExternalRefFilename);
    }

    /*
     * Walk and emit the list of externals found during the AML parsing
     */
    while (AcpiGbl_ExternalList)
    {
        if (!(AcpiGbl_ExternalList->Flags & ACPI_EXT_EXTERNAL_EMITTED))
        {
            AcpiOsPrintf ("    External (%s%s)",
                AcpiGbl_ExternalList->Path,
                AcpiDmGetObjectTypeName (AcpiGbl_ExternalList->Type));

            /* Check for "unresolved" method reference */

            if ((AcpiGbl_ExternalList->Type == ACPI_TYPE_METHOD) &&
                (!(AcpiGbl_ExternalList->Flags & ACPI_EXT_RESOLVED_REFERENCE)))
            {
                AcpiOsPrintf ("    // Warning: Unknown method, "
                    "guessing %u arguments",
                    AcpiGbl_ExternalList->Value);
            }

            /* Check for external from a external references file */

            else if (AcpiGbl_ExternalList->Flags & ACPI_EXT_ORIGIN_FROM_FILE)
            {
                if (AcpiGbl_ExternalList->Type == ACPI_TYPE_METHOD)
                {
                    AcpiOsPrintf ("    // %u Arguments",
                        AcpiGbl_ExternalList->Value);
                }

                AcpiOsPrintf ("    // From external reference file");
            }

            /* This is the normal external case */

            else
            {
                /* For methods, add a comment with the number of arguments */

                if (AcpiGbl_ExternalList->Type == ACPI_TYPE_METHOD)
                {
                    AcpiOsPrintf ("    // %u Arguments",
                        AcpiGbl_ExternalList->Value);
                }
            }

            if (AcpiGbl_ExternalList->Flags &= ACPI_EXT_CONFLICTING_DECLARATION)
            {
                AcpiOsPrintf ("%s", ExternalConflictMessage);
                AcpiDmConflictingDeclaration (AcpiGbl_ExternalList->Path);
            }
            AcpiOsPrintf ("\n");
        }

        /* Free this external info block and move on to next external */

        NextExternal = AcpiGbl_ExternalList->Next;
        if (AcpiGbl_ExternalList->Flags & ACPI_EXT_INTERNAL_PATH_ALLOCATED)
        {
            ACPI_FREE (AcpiGbl_ExternalList->InternalPath);
        }

        ACPI_FREE (AcpiGbl_ExternalList->Path);
        ACPI_FREE (AcpiGbl_ExternalList);
        AcpiGbl_ExternalList = NextExternal;
    }

    AcpiOsPrintf ("\n");
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmMarkExternalConflict
 *
 * PARAMETERS:  Path          - Namepath to search
 *
 * RETURN:      ExternalList
 *
 * DESCRIPTION: Search the AcpiGbl_ExternalList for a matching path
 *
 ******************************************************************************/

void
AcpiDmMarkExternalConflict (
    ACPI_NAMESPACE_NODE     *Node)
{
    ACPI_EXTERNAL_LIST      *ExternalList = AcpiGbl_ExternalList;
    char                    *ExternalPath;
    char                    *InternalPath;
    char                    *Temp;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (DmMarkExternalConflict);


    if (Node->Flags & ANOBJ_IS_EXTERNAL)
    {
        return_VOID;
    }

    /* Get the full external and internal pathnames to the node */

    Status = AcpiDmGetExternalAndInternalPath (Node,
        &ExternalPath, &InternalPath);
    if (ACPI_FAILURE (Status))
    {
        return_VOID;
    }

    /* Remove the root backslash */

    Status = AcpiDmRemoveRootPrefix (&InternalPath);
    if (ACPI_FAILURE (Status))
    {
        ACPI_FREE (InternalPath);
        ACPI_FREE (ExternalPath);
        return_VOID;
    }

    while (ExternalList)
    {
        Temp = ExternalList->InternalPath;
        if ((*ExternalList->InternalPath == AML_ROOT_PREFIX) &&
            (ExternalList->InternalPath[1]))
        {
            Temp++;
        }

        if (!strcmp (ExternalList->InternalPath, InternalPath))
        {
            ExternalList->Flags |= ACPI_EXT_CONFLICTING_DECLARATION;
        }
        ExternalList = ExternalList->Next;
    }

    ACPI_FREE (InternalPath);
    ACPI_FREE (ExternalPath);

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmConflictingDeclaration
 *
 * PARAMETERS:  Path                - Path with conflicting declaration
 *
 * RETURN:      None
 *
 * DESCRIPTION: Emit a warning when printing conflicting ASL external
 *              declarations.
 *
 ******************************************************************************/

static void
AcpiDmConflictingDeclaration (
    char                    *Path)
{
    fprintf (stderr,
        " Warning - Emitting ASL code \"External (%s)\"\n"
        "           This is a conflicting declaration with some "
        "other declaration within the ASL code.\n"
        "           This external declaration may need to be "
        "deleted in order to recompile the dsl file.\n\n",
        Path);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmEmitExternal
 *
 * PARAMETERS:  Op                  External Parse Object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Emit an External() ASL statement for the current External
 *              parse object. Note: External Ops are named types so the
 *              namepath is contained within NameOp->Name.Path.
 *
 ******************************************************************************/

void
AcpiDmEmitExternal (
    ACPI_PARSE_OBJECT       *NameOp,
    ACPI_PARSE_OBJECT       *TypeOp)
{
    AcpiOsPrintf ("External (");
    AcpiDmNamestring (NameOp->Named.Path);
    AcpiOsPrintf ("%s)",
        AcpiDmGetObjectTypeName ((ACPI_OBJECT_TYPE) TypeOp->Common.Value.Integer));
    AcpiDmCheckForExternalConflict (NameOp->Named.Path);
    AcpiOsPrintf ("\n");
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiDmCheckForExternalConflict
 *
 * PARAMETERS:  Path                - Path to check
 *
 * RETURN:      None
 *
 * DESCRIPTION: Search the External List to see if the input Path has a
 *              conflicting declaration.
 *
 ******************************************************************************/

static void
AcpiDmCheckForExternalConflict (
    char                    *Path)
{
    ACPI_EXTERNAL_LIST      *ExternalList = AcpiGbl_ExternalList;
    char                    *ListItemPath;
    char                    *InputPath;


    if (!Path)
    {
        return;
    }

    /* Move past the root prefix '\' */

    InputPath = Path;
    if ((*InputPath == AML_ROOT_PREFIX) && InputPath[1])
    {
        InputPath++;
    }

    while (ExternalList)
    {
        ListItemPath = ExternalList->Path;
        if (ListItemPath)
        {
            /* Move past the root prefix '\' */

            if ((*ListItemPath == AML_ROOT_PREFIX) &&
                ListItemPath[1])
            {
                ListItemPath++;
            }

            if (!strcmp (ListItemPath, InputPath) &&
                (ExternalList->Flags & ACPI_EXT_CONFLICTING_DECLARATION))
            {
                AcpiOsPrintf ("%s", ExternalConflictMessage);
                AcpiDmConflictingDeclaration (Path);

                return;
            }
        }
        ExternalList = ExternalList->Next;
    }
}
/*******************************************************************************
 *
 * FUNCTION:    AcpiDmUnresolvedWarning
 *
 * PARAMETERS:  Type                - Where to output the warning.
 *                                    0 means write to stderr
 *                                    1 means write to AcpiOsPrintf
 *
 * RETURN:      None
 *
 * DESCRIPTION: Issue warning message if there are unresolved external control
 *              methods within the disassembly.
 *
 ******************************************************************************/

/*
Summary of the external control method problem:

When the -e option is used with disassembly, the various SSDTs are simply
loaded into a global namespace for the disassembler to use in order to
resolve control method references (invocations).

The disassembler tracks any such references, and will emit an External()
statement for these types of methods, with the proper number of arguments .

Without the SSDTs, the AML does not contain enough information to properly
disassemble the control method invocation -- because the disassembler does
not know how many arguments to parse.

An example: Assume we have two control methods. ABCD has one argument, and
EFGH has zero arguments. Further, we have two additional control methods
that invoke ABCD and EFGH, named T1 and T2:

    Method (ABCD, 1)
    {
    }
    Method (EFGH, 0)
    {
    }
    Method (T1)
    {
        ABCD (Add (2, 7, Local0))
    }
    Method (T2)
    {
        EFGH ()
        Add (2, 7, Local0)
    }

Here is the AML code that is generated for T1 and T2:

     185:      Method (T1)

0000034C:  14 10 54 31 5F 5F 00 ...    "..T1__."

     186:      {
     187:          ABCD (Add (2, 7, Local0))

00000353:  41 42 43 44 ............    "ABCD"
00000357:  72 0A 02 0A 07 60 ......    "r....`"

     188:      }

     190:      Method (T2)

0000035D:  14 10 54 32 5F 5F 00 ...    "..T2__."

     191:      {
     192:          EFGH ()

00000364:  45 46 47 48 ............    "EFGH"

     193:          Add (2, 7, Local0)

00000368:  72 0A 02 0A 07 60 ......    "r....`"
     194:      }

Note that the AML code for T1 and T2 is essentially identical. When
disassembling this code, the methods ABCD and EFGH must be known to the
disassembler, otherwise it does not know how to handle the method invocations.

In other words, if ABCD and EFGH are actually external control methods
appearing in an SSDT, the disassembler does not know what to do unless
the owning SSDT has been loaded via the -e option.
*/

static char             ExternalWarningPart1[600];
static char             ExternalWarningPart2[400];
static char             ExternalWarningPart3[400];
static char             ExternalWarningPart4[200];

void
AcpiDmUnresolvedWarning (
    UINT8                   Type)
{
    char                    *Format;
    char                    Pad[] = "     *";
    char                    NoPad[] = "";


    if (!AcpiGbl_NumExternalMethods)
    {
        return;
    }

    if (AcpiGbl_NumExternalMethods == AcpiGbl_ResolvedExternalMethods)
    {
        return;
    }

    Format = Type ? Pad : NoPad;

    sprintf (ExternalWarningPart1,
        "%s iASL Warning: There %s %u external control method%s found during\n"
        "%s disassembly, but only %u %s resolved (%u unresolved). Additional\n"
        "%s ACPI tables may be required to properly disassemble the code. This\n"
        "%s resulting disassembler output file may not compile because the\n"
        "%s disassembler did not know how many arguments to assign to the\n"
        "%s unresolved methods. Note: SSDTs can be dynamically loaded at\n"
        "%s runtime and may or may not be available via the host OS.\n",
        Format, (AcpiGbl_NumExternalMethods != 1 ? "were" : "was"),
        AcpiGbl_NumExternalMethods, (AcpiGbl_NumExternalMethods != 1 ? "s" : ""),
        Format, AcpiGbl_ResolvedExternalMethods,
        (AcpiGbl_ResolvedExternalMethods != 1 ? "were" : "was"),
        (AcpiGbl_NumExternalMethods - AcpiGbl_ResolvedExternalMethods),
        Format, Format, Format, Format, Format);

    sprintf (ExternalWarningPart2,
        "%s To specify the tables needed to resolve external control method\n"
        "%s references, the -e option can be used to specify the filenames.\n"
        "%s Example iASL invocations:\n"
        "%s     iasl -e ssdt1.aml ssdt2.aml ssdt3.aml -d dsdt.aml\n"
        "%s     iasl -e dsdt.aml ssdt2.aml -d ssdt1.aml\n"
        "%s     iasl -e ssdt*.aml -d dsdt.aml\n",
        Format, Format, Format, Format, Format, Format);

    sprintf (ExternalWarningPart3,
        "%s In addition, the -fe option can be used to specify a file containing\n"
        "%s control method external declarations with the associated method\n"
        "%s argument counts. Each line of the file must be of the form:\n"
        "%s     External (<method pathname>, MethodObj, <argument count>)\n"
        "%s Invocation:\n"
        "%s     iasl -fe refs.txt -d dsdt.aml\n",
        Format, Format, Format, Format, Format, Format);

    sprintf (ExternalWarningPart4,
        "%s The following methods were unresolved and many not compile properly\n"
        "%s because the disassembler had to guess at the number of arguments\n"
        "%s required for each:\n",
        Format, Format, Format);

    if (Type)
    {
        if (!AcpiGbl_ExternalFileList)
        {
            /* The -e option was not specified */

           AcpiOsPrintf ("    /*\n%s     *\n%s     *\n%s     *\n%s     */\n",
               ExternalWarningPart1, ExternalWarningPart2, ExternalWarningPart3,
               ExternalWarningPart4);
        }
        else
        {
            /* The -e option was specified, but there are still some unresolved externals */

            AcpiOsPrintf ("    /*\n%s     *\n%s     *\n%s     */\n",
               ExternalWarningPart1, ExternalWarningPart3, ExternalWarningPart4);
        }
    }
    else
    {
        if (!AcpiGbl_ExternalFileList)
        {
            /* The -e option was not specified */

            fprintf (stderr, "\n%s\n%s\n%s\n",
               ExternalWarningPart1, ExternalWarningPart2, ExternalWarningPart3);
        }
        else
        {
            /* The -e option was specified, but there are still some unresolved externals */

            fprintf (stderr, "\n%s\n%s\n",
               ExternalWarningPart1, ExternalWarningPart3);
        }
    }
}
