Tcl Source Code

#include "tclCompile.h"

/*
 * Declarations for functions local to this file:
 */

static inline Tcl_Obj *	NewNsObj(Tcl_Namespace *namespacePtr);
static Tcl_Command	InitEnsembleFromOptions(Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		ReadOneEnsembleOption(Tcl_Interp *interp,
			    Tcl_Command token, Tcl_Obj *optionObj);
static int		ReadAllEnsembleOptions(Tcl_Interp *interp,
			    Tcl_Command token);
static int		SetEnsembleConfigOptions(Tcl_Interp *interp,
			    Tcl_Command token, int objc,
			    Tcl_Obj *const objv[]);
static inline int	EnsembleUnknownCallback(Tcl_Interp *interp,
			    EnsembleConfig *ensemblePtr, int objc,
			    Tcl_Obj *const objv[], Tcl_Obj **prefixObjPtr);
static int		NsEnsembleImplementationCmdNR(void *clientData,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static void		BuildEnsembleConfig(EnsembleConfig *ensemblePtr);
static int		NsEnsembleStringOrder(const void *strPtr1,

    "ensembleCommand",		/* the type's name */
    FreeEnsembleCmdRep,		/* freeIntRepProc */
    DupEnsembleCmdRep,		/* dupIntRepProc */
    NULL,			/* updateStringProc */
    NULL			/* setFromAnyProc */
};

#define ECRSetInternalRep(objPtr, ecRepPtr) \
    do {								\
	Tcl_ObjInternalRep ir;						\
	ir.twoPtrValue.ptr1 = (ecRepPtr);				\
	ir.twoPtrValue.ptr2 = NULL;					\
	Tcl_StoreInternalRep((objPtr), &ensembleCmdType, &ir);		\
    } while (0)

#define ECRGetInternalRep(objPtr, ecRepPtr) \
    do {								\
	const Tcl_ObjInternalRep *irPtr;				\
	irPtr = TclFetchInternalRep((objPtr), &ensembleCmdType);	\
	(ecRepPtr) = irPtr ? (EnsembleCmdRep *)				\
		irPtr->twoPtrValue.ptr1 : NULL;				\
    } while (0)

/*
 * The internal rep for caching ensemble subcommand lookups and spelling
 * corrections.
 */

typedef struct {
    Tcl_Size epoch;		/* Used to confirm when the data in this
				 * really structure matches up with the
				 * ensemble. */
    Command *token;		/* Reference to the command for which this
				 * structure is a cache of the resolution. */
    Tcl_Obj *fix;		/* Corrected spelling, if needed. */
    Tcl_HashEntry *hPtr;	/* Direct link to entry in the subcommand hash
				 * table. */
} EnsembleCmdRep;

/*
 *----------------------------------------------------------------------
 *
 * NewNsObj --
 *
 *	Make an object that contains a namespace's name.
 *
 * TODO:
 * 	This is a candidate for doing something better!
 *
 *----------------------------------------------------------------------
 */
static inline Tcl_Obj *
NewNsObj(
    Tcl_Namespace *namespacePtr)
{
    Namespace *nsPtr = (Namespace *) namespacePtr;

    if (namespacePtr == TclGetGlobalNamespace(nsPtr->interp)) {
	return Tcl_NewStringObj("::", 2);
    }
    return Tcl_NewStringObj(nsPtr->fullName, TCL_AUTO_LENGTH);
}

/*
 *----------------------------------------------------------------------
 *
 * TclNamespaceEnsembleCmd --
 *

int
TclNamespaceEnsembleCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{

    Namespace *nsPtr = (Namespace *) TclGetCurrentNamespace(interp);

    Tcl_Command token;		/* The ensemble command. */



    int index;


    if (nsPtr == NULL || nsPtr->flags & NS_DEAD) {
	if (!Tcl_InterpDeleted(interp)) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "tried to manipulate ensemble of deleted namespace",
		    TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "DEAD", (char *)NULL);
	}
	return TCL_ERROR;
    }

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "subcommand ?arg ...?");
	return TCL_ERROR;

    } else if (Tcl_GetIndexFromObj(interp, objv[1], ensembleSubcommands,
	    "subcommand", 0, &index) != TCL_OK) {
	return TCL_ERROR;
    }

    switch ((enum EnsSubcmds) index) {
    case ENS_CREATE:












	/*
	 * Check that we've got option-value pairs... [Bug 1558654]
	 */

	if (objc & 1) {
	    Tcl_WrongNumArgs(interp, 2, objv, "?option value ...?");
	    return TCL_ERROR;
	}


	token = InitEnsembleFromOptions(interp, objc - 2, objv + 2);



































































































	if (token == NULL) {
























	    return TCL_ERROR;
	}

































	/*
	 * Tricky! Must ensure that the result is not shared (command delete
	 * traces could have corrupted the pristine object that we started
	 * with). [Snit test rename-1.5]
	 */

	Tcl_ResetResult(interp);
	Tcl_GetCommandFullName(interp, token, Tcl_GetObjResult(interp));
	return TCL_OK;


    case ENS_EXISTS:
	if (objc != 3) {
	    Tcl_WrongNumArgs(interp, 2, objv, "cmdname");
	    return TCL_ERROR;
	}
	Tcl_SetObjResult(interp, Tcl_NewBooleanObj(

	}
	token = Tcl_FindEnsemble(interp, objv[2], TCL_LEAVE_ERR_MSG);
	if (token == NULL) {
	    return TCL_ERROR;
	}

	if (objc == 4) {

	    return ReadOneEnsembleOption(interp, token, objv[3]);











































	} else if (objc == 3) {



	    return ReadAllEnsembleOptions(interp, token);

















































	} else {





	    return SetEnsembleConfigOptions(interp, token, objc - 3, objv + 3);






	}













































































































































    default:
	Tcl_Panic("unexpected ensemble command");
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * InitEnsembleFromOptions --
 *
 *	Core of implementation of "namespace ensemble create".
 *
 * Results:
 *	Returns created ensemble's command token if successful, and NULL if
 *	anything goes wrong.
 *
 * Side effects:
 *	Creates the ensemble for the namespace if one did not previously
 *	exist.
 *
 * Note:
 *	Can't use SetEnsembleConfigOptions() here. Different (but overlapping)
 *	options are supported. 
 *
 *----------------------------------------------------------------------
 */
static Tcl_Command
InitEnsembleFromOptions(
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{
    Namespace *nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    Namespace *cxtPtr = nsPtr->parentPtr;
    Namespace *altFoundNsPtr, *actualCxtPtr;
    const char *name = nsPtr->name;
    Tcl_Size len;
    int allocatedMapFlag = 0;
    int index;
    Tcl_Command token;		/* The created ensemble command. */
    Namespace *foundNsPtr;
    const char *simpleName;
    /*
     * Defaults
     */
    Tcl_Obj *subcmdObj = NULL;
    Tcl_Obj *mapObj = NULL;
    int permitPrefix = 1;
    Tcl_Obj *unknownObj = NULL;
    Tcl_Obj *paramObj = NULL;

    /*
     * Parse the option list, applying type checks as we go. Note that we are
     * not incrementing any reference counts in the objects at this stage, so
     * the presence of an option multiple times won't cause any memory leaks.
     */

    for (; objc>1 ; objc-=2,objv+=2) {
	if (Tcl_GetIndexFromObj(interp, objv[0], ensembleCreateOptions,
		"option", 0, &index) != TCL_OK) {
	    goto error;
	}
	switch ((enum EnsCreateOpts) index) {
	case CRT_CMD:
	    name = TclGetString(objv[1]);
	    cxtPtr = nsPtr;
	    continue;
	case CRT_SUBCMDS:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto error;
	    }
	    subcmdObj = (len > 0 ? objv[1] : NULL);
	    continue;
	case CRT_PARAM:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto error;
	    }
	    paramObj = (len > 0 ? objv[1] : NULL);
	    continue;
	case CRT_MAP: {
	    Tcl_Obj *patchedDict = NULL, *subcmdWordsObj, *listObj;
	    Tcl_DictSearch search;
	    int done;

	    /*
	     * Verify that the map is sensible.
	     */

	    if (Tcl_DictObjFirst(interp, objv[1], &search,
		    &subcmdWordsObj, &listObj, &done) != TCL_OK) {
		goto error;
	    } else if (done) {
		mapObj = NULL;
		continue;
	    }
	    do {
		Tcl_Obj **listv;
		const char *cmd;

		if (TclListObjGetElements(interp, listObj, &len,
			&listv) != TCL_OK) {
		    goto mapError;
		}
		if (len < 1) {
		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
			    "ensemble subcommand implementations "
			    "must be non-empty lists", TCL_AUTO_LENGTH));
		    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
			    "EMPTY_TARGET", (char *)NULL);
		    goto mapError;
		}
		cmd = TclGetString(listv[0]);
		if (!(cmd[0] == ':' && cmd[1] == ':')) {
		    Tcl_Obj *newList = Tcl_NewListObj(len, listv);
		    Tcl_Obj *newCmd = NewNsObj((Tcl_Namespace *) nsPtr);

		    if (nsPtr->parentPtr) {
			Tcl_AppendStringsToObj(newCmd, "::", (char *)NULL);
		    }
		    Tcl_AppendObjToObj(newCmd, listv[0]);
		    Tcl_ListObjReplace(NULL, newList, 0, 1, 1, &newCmd);
		    if (patchedDict == NULL) {
			patchedDict = Tcl_DuplicateObj(objv[1]);
		    }
		    Tcl_DictObjPut(NULL, patchedDict, subcmdWordsObj, newList);
		}
		Tcl_DictObjNext(&search, &subcmdWordsObj, &listObj, &done);
	    } while (!done);

	    if (allocatedMapFlag) {
		Tcl_DecrRefCount(mapObj);
	    }
	    mapObj = (patchedDict ? patchedDict : objv[1]);
	    if (patchedDict) {
		allocatedMapFlag = 1;
	    }
	    continue;
	mapError:
	    Tcl_DictObjDone(&search);
	    if (patchedDict) {
		Tcl_DecrRefCount(patchedDict);
	    }
	    goto error;
	}
	case CRT_PREFIX:
	    if (Tcl_GetBooleanFromObj(interp, objv[1],
		    &permitPrefix) != TCL_OK) {
		goto error;
	    }
	    continue;
	case CRT_UNKNOWN:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto error;
	    }
	    unknownObj = (len > 0 ? objv[1] : NULL);
	    continue;
	}
    }

    TclGetNamespaceForQualName(interp, name, cxtPtr,
	    TCL_CREATE_NS_IF_UNKNOWN, &foundNsPtr, &altFoundNsPtr,
	    &actualCxtPtr, &simpleName);

    /*
     * Create the ensemble. Note that this might delete another ensemble
     * linked to the same namespace, so we must be careful. However, we
     * should be OK because we only link the namespace into the list once
     * we've created it (and after any deletions have occurred.)
     */

    token = TclCreateEnsembleInNs(interp, simpleName,
	    (Tcl_Namespace *) foundNsPtr, (Tcl_Namespace *) nsPtr,
	    (permitPrefix ? TCL_ENSEMBLE_PREFIX : 0));
    Tcl_SetEnsembleSubcommandList(interp, token, subcmdObj);
    Tcl_SetEnsembleMappingDict(interp, token, mapObj);
    Tcl_SetEnsembleUnknownHandler(interp, token, unknownObj);
    Tcl_SetEnsembleParameterList(interp, token, paramObj);
    return token;

  error:
    if (allocatedMapFlag) {
	Tcl_DecrRefCount(mapObj);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * ReadOneEnsembleOption --
 *
 *	Core of implementation of "namespace ensemble configure" with just a
 *	single option name.
 *
 * Results:
 *	Tcl result code. Modifies the interpreter result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */
static int
ReadOneEnsembleOption(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble to read from. */
    Tcl_Obj *optionObj)		/* The name of the option to read. */
{
    Tcl_Obj *resultObj = NULL;			/* silence gcc 4 warning */
    int index;

    if (Tcl_GetIndexFromObj(interp, optionObj, ensembleConfigOptions,
	    "option", 0, &index) != TCL_OK) {
	return TCL_ERROR;
    }
    switch ((enum EnsConfigOpts) index) {
    case CONF_SUBCMDS:
	Tcl_GetEnsembleSubcommandList(NULL, token, &resultObj);
	if (resultObj != NULL) {
	    Tcl_SetObjResult(interp, resultObj);
	}
	break;
    case CONF_PARAM:
	Tcl_GetEnsembleParameterList(NULL, token, &resultObj);
	if (resultObj != NULL) {
	    Tcl_SetObjResult(interp, resultObj);
	}
	break;
    case CONF_MAP:
	Tcl_GetEnsembleMappingDict(NULL, token, &resultObj);
	if (resultObj != NULL) {
	    Tcl_SetObjResult(interp, resultObj);
	}
	break;
    case CONF_NAMESPACE: {
	Tcl_Namespace *namespacePtr = NULL;	/* silence gcc 4 warning */
	Tcl_GetEnsembleNamespace(NULL, token, &namespacePtr);
	Tcl_SetObjResult(interp, NewNsObj(namespacePtr));
	break;
    }
    case CONF_PREFIX: {
	int flags = 0;				/* silence gcc 4 warning */

	Tcl_GetEnsembleFlags(NULL, token, &flags);
	Tcl_SetObjResult(interp,
		Tcl_NewBooleanObj(flags & TCL_ENSEMBLE_PREFIX));
	break;
    }
    case CONF_UNKNOWN:
	Tcl_GetEnsembleUnknownHandler(NULL, token, &resultObj);
	if (resultObj != NULL) {
	    Tcl_SetObjResult(interp, resultObj);
	}
	break;
    }
    return TCL_OK;
}
/*
 *----------------------------------------------------------------------
 *
 * ReadAllEnsembleOptions --
 *
 *	Core of implementation of "namespace ensemble configure" without
 *	option names.
 *
 * Results:
 *	Tcl result code. Modifies the interpreter result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */
static int
ReadAllEnsembleOptions(
    Tcl_Interp *interp,
    Tcl_Command token)		/* The ensemble to read from. */
{
    Tcl_Obj *resultObj, *tmpObj = NULL;	/* silence gcc 4 warning */
    int flags = 0;			/* silence gcc 4 warning */
    Tcl_Namespace *namespacePtr = NULL;	/* silence gcc 4 warning */

    TclNewObj(resultObj);

    /* -map option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_MAP],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleMappingDict(NULL, token, &tmpObj);
    Tcl_ListObjAppendElement(NULL, resultObj,
	    (tmpObj != NULL) ? tmpObj : Tcl_NewObj());

    /* -namespace option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_NAMESPACE],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleNamespace(NULL, token, &namespacePtr);
    Tcl_ListObjAppendElement(NULL, resultObj, NewNsObj(namespacePtr));

    /* -parameters option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_PARAM],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleParameterList(NULL, token, &tmpObj);
    Tcl_ListObjAppendElement(NULL, resultObj,
	    (tmpObj != NULL) ? tmpObj : Tcl_NewObj());

    /* -prefix option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_PREFIX],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleFlags(NULL, token, &flags);
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewBooleanObj(flags & TCL_ENSEMBLE_PREFIX));

    /* -subcommands option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_SUBCMDS],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleSubcommandList(NULL, token, &tmpObj);
    Tcl_ListObjAppendElement(NULL, resultObj,
	    (tmpObj != NULL) ? tmpObj : Tcl_NewObj());

    /* -unknown option */
    Tcl_ListObjAppendElement(NULL, resultObj,
	    Tcl_NewStringObj(ensembleConfigOptions[CONF_UNKNOWN],
		    TCL_AUTO_LENGTH));
    Tcl_GetEnsembleUnknownHandler(NULL, token, &tmpObj);
    Tcl_ListObjAppendElement(NULL, resultObj,
	    (tmpObj != NULL) ? tmpObj : Tcl_NewObj());

    Tcl_SetObjResult(interp, resultObj);
    return TCL_OK;
}
/*
 *----------------------------------------------------------------------
 *
 * SetEnsembleConfigOptions --
 *
 *	Core of implementation of "namespace ensemble configure" with even
 *	number of arguments (where there is at least one pair).
 *
 * Results:
 *	Tcl result code. Modifies the interpreter result.
 *
 * Side effects:
 *	Modifies the ensemble's configuration.
 *
 *----------------------------------------------------------------------
 */
static int
SetEnsembleConfigOptions(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble to configure. */
    int objc,			/* The count of option-related arguments. */
    Tcl_Obj *const objv[])	/* Option-related arguments. */
{
    Tcl_Size len;
    int allocatedMapFlag = 0;
    Tcl_Obj *subcmdObj = NULL, *mapObj = NULL, *paramObj = NULL,
	    *unknownObj = NULL; 	/* Defaults, silence gcc 4 warnings */
    Tcl_Obj *listObj;
    Tcl_DictSearch search;
    int permitPrefix, flags = 0;	/* silence gcc 4 warning */
    int index, done;

    Tcl_GetEnsembleSubcommandList(NULL, token, &subcmdObj);
    Tcl_GetEnsembleMappingDict(NULL, token, &mapObj);
    Tcl_GetEnsembleParameterList(NULL, token, &paramObj);
    Tcl_GetEnsembleUnknownHandler(NULL, token, &unknownObj);
    Tcl_GetEnsembleFlags(NULL, token, &flags);
    permitPrefix = (flags & TCL_ENSEMBLE_PREFIX) != 0;

    /*
     * Parse the option list, applying type checks as we go. Note that
     * we are not incrementing any reference counts in the objects at
     * this stage, so the presence of an option multiple times won't
     * cause any memory leaks.
     */

    for (; objc>0 ; objc-=2,objv+=2) {
	if (Tcl_GetIndexFromObj(interp, objv[0], ensembleConfigOptions,
		"option", 0, &index) != TCL_OK) {
	    goto freeMapAndError;
	}
	switch ((enum EnsConfigOpts) index) {
	case CONF_SUBCMDS:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto freeMapAndError;
	    }
	    subcmdObj = (len > 0 ? objv[1] : NULL);
	    continue;
	case CONF_PARAM:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto freeMapAndError;
	    }
	    paramObj = (len > 0 ? objv[1] : NULL);
	    continue;
	case CONF_MAP: {
	    Tcl_Obj *patchedDict = NULL, *subcmdWordsObj, **listv;
	    Namespace *nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
	    const char *cmd;

	    /*
	     * Verify that the map is sensible.
	     */

	    if (Tcl_DictObjFirst(interp, objv[1], &search,
		    &subcmdWordsObj, &listObj, &done) != TCL_OK) {
		goto freeMapAndError;
	    } else if (done) {
		mapObj = NULL;
		continue;
	    }

	    do {
		if (TclListObjLength(interp, listObj, &len) != TCL_OK) {
		    goto finishSearchAndError;
		}
		if (len < 1) {
		    Tcl_SetObjResult(interp, Tcl_NewStringObj(
			    "ensemble subcommand implementations "
			    "must be non-empty lists", TCL_AUTO_LENGTH));
		    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
			    "EMPTY_TARGET", (char *)NULL);
		    goto finishSearchAndError;
		}
		if (TclListObjGetElements(interp, listObj, &len,
			&listv) != TCL_OK) {
		    goto finishSearchAndError;
		}
		cmd = TclGetString(listv[0]);
		if (!(cmd[0] == ':' && cmd[1] == ':')) {
		    Tcl_Obj *newList = Tcl_DuplicateObj(listObj);
		    Tcl_Obj *newCmd = NewNsObj((Tcl_Namespace*) nsPtr);

		    if (nsPtr->parentPtr) {
			Tcl_AppendStringsToObj(newCmd, "::", (char *)NULL);
		    }
		    Tcl_AppendObjToObj(newCmd, listv[0]);
		    Tcl_ListObjReplace(NULL, newList, 0, 1, 1, &newCmd);
		    if (patchedDict == NULL) {
			patchedDict = Tcl_DuplicateObj(objv[1]);
		    }
		    Tcl_DictObjPut(NULL, patchedDict, subcmdWordsObj, newList);
		}
		Tcl_DictObjNext(&search, &subcmdWordsObj, &listObj, &done);
	    } while (!done);
	    if (allocatedMapFlag) {
		Tcl_DecrRefCount(mapObj);
	    }
	    mapObj = (patchedDict ? patchedDict : objv[1]);
	    if (patchedDict) {
		allocatedMapFlag = 1;
	    }
	    continue;

	finishSearchAndError:
	    Tcl_DictObjDone(&search);
	    if (patchedDict) {
		Tcl_DecrRefCount(patchedDict);
	    }
	    goto freeMapAndError;
	}
	case CONF_NAMESPACE:
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "option -namespace is read-only", TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "READ_ONLY",
		    (char *)NULL);
	    goto freeMapAndError;
	case CONF_PREFIX:
	    if (Tcl_GetBooleanFromObj(interp, objv[1],
		    &permitPrefix) != TCL_OK) {
		goto freeMapAndError;
	    }
	    continue;
	case CONF_UNKNOWN:
	    if (TclListObjLength(interp, objv[1], &len) != TCL_OK) {
		goto freeMapAndError;
	    }
	    unknownObj = (len > 0 ? objv[1] : NULL);
	    continue;
	}
    }

    /*
     * Update the namespace now that we've finished the parsing stage.
     */

    flags = (permitPrefix ? flags | TCL_ENSEMBLE_PREFIX
	    : flags & ~TCL_ENSEMBLE_PREFIX);
    Tcl_SetEnsembleSubcommandList(interp, token, subcmdObj);
    Tcl_SetEnsembleMappingDict(interp, token, mapObj);
    Tcl_SetEnsembleParameterList(interp, token, paramObj);
    Tcl_SetEnsembleUnknownHandler(interp, token, unknownObj);
    Tcl_SetEnsembleFlags(interp, token, flags);
    return TCL_OK;

  freeMapAndError:
    if (allocatedMapFlag) {
	Tcl_DecrRefCount(mapObj);
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * TclCreateEnsembleInNs --
 *
 *	Like Tcl_CreateEnsemble, but additionally accepts as an argument the

    Tcl_Interp *interp,
    const char *name,		/* Simple name of command to create (no
				 * namespace components). */
    Tcl_Namespace *nameNsPtr,	/* Name of namespace to create the command
				 * in. */
    Tcl_Namespace *ensembleNsPtr,
				/* Name of the namespace for the ensemble. */
    int flags)			/* Whether we need exact matching and whether
				 * we bytecode-compile the ensemble's uses. */
{
    Namespace *nsPtr = (Namespace *) ensembleNsPtr;
    EnsembleConfig *ensemblePtr;
    Tcl_Command token;

    ensemblePtr = (EnsembleConfig *) ckalloc(sizeof(EnsembleConfig));
    token = TclNRCreateCommandInNs(interp, name,
	    (Tcl_Namespace *) nameNsPtr, TclEnsembleImplementationCmd,
	    NsEnsembleImplementationCmdNR, ensemblePtr, DeleteEnsembleConfig);
    if (token == NULL) {
	ckfree(ensemblePtr);
	return NULL;
    }

 * Value
 *
 *	The token for the command created.
 *
 * Effect
 *	The ensemble is created and marked for compilation.
 *

 *----------------------------------------------------------------------
 */

Tcl_Command
Tcl_CreateEnsemble(
    Tcl_Interp *interp,
    const char *name,		/* The ensemble name. */
    Tcl_Namespace *namespacePtr,/* Context namespace. */
    int flags)			/* Whether we need exact matching and whether
				 * we bytecode-compile the ensemble's uses. */
{
    Namespace *nsPtr = (Namespace *) namespacePtr, *foundNsPtr, *altNsPtr,
	    *actualNsPtr;
    const char * simpleName;

    if (nsPtr == NULL) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    }

    TclGetNamespaceForQualName(interp, name, nsPtr, TCL_CREATE_NS_IF_UNKNOWN,
	    &foundNsPtr, &altNsPtr, &actualNsPtr, &simpleName);
    return TclCreateEnsembleInNs(interp, simpleName,
	    (Tcl_Namespace *) foundNsPtr, (Tcl_Namespace *) nsPtr, flags);
}

/*
 *----------------------------------------------------------------------
 *
 * GetEnsembleFromCommand --
 *
 *	Standard check to see if a command is an ensemble.
 *
 * Results:
 *	The ensemble implementation if the command is an ensemble. NULL if it
 *	isn't.
 *
 * Side effects:
 *	Reports an error in the interpreter (if non-NULL) if the command is
 *	not an ensemble.
 *
 *----------------------------------------------------------------------
 */
static inline EnsembleConfig *
GetEnsembleFromCommand(
    Tcl_Interp *interp,		/* Where to report an error. May be NULL. */	
    Tcl_Command token)		/* What to check for ensemble-ness. */
{
    Command *cmdPtr = (Command *) token;

    if (cmdPtr->objProc != TclEnsembleImplementationCmd) {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "command is not an ensemble", TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp,
		    "TCL", "ENSEMBLE", "NOT_ENSEMBLE", (char *)NULL);
	}
	return NULL;
    }
    return (EnsembleConfig *) cmdPtr->objClientData;
}

/*
 *----------------------------------------------------------------------
 *
 * BumpEpochIfNecessary --
 *
 *	Increments the compilation epoch if the (ensemble) command is one where
 *	changes would be seen by the compiler in some cases.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May trigger later bytecode recompilations.
 *
 *----------------------------------------------------------------------
 */
static inline void
BumpEpochIfNecessary(
    Tcl_Interp *interp,
    Tcl_Command token)		/* The ensemble command to check. */
{
    /*
     * Special hack to make compiling of [info exists] work when the
     * dictionary is modified.
     */

    if (((Command *) token)->compileProc != NULL) {
	((Interp *) interp)->compileEpoch++;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetEnsembleSubcommandList --
 *
 *	Set the subcommand list for a particular ensemble.

 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetEnsembleSubcommandList(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to write to. */
    Tcl_Obj *subcmdList)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);
    Tcl_Obj *oldList;



    if (ensemblePtr == NULL) {

	return TCL_ERROR;
    }
    if (subcmdList != NULL) {
	Tcl_Size length;

	if (TclListObjLength(interp, subcmdList, &length) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (length < 1) {
	    subcmdList = NULL;
	}
    }


    oldList = ensemblePtr->subcmdList;
    ensemblePtr->subcmdList = subcmdList;
    if (subcmdList != NULL) {
	Tcl_IncrRefCount(subcmdList);
    }
    if (oldList != NULL) {
	TclDecrRefCount(oldList);
    }

    /*
     * Trigger an eventual recomputation of the ensemble command set. Note
     * that this is slightly tricky, as it means that we are not actually
     * counting the number of namespace export actions, but it is the simplest
     * way to go!
     */

    ensemblePtr->nsPtr->exportLookupEpoch++;
    BumpEpochIfNecessary(interp, token);









    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetEnsembleParameterList --

 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetEnsembleParameterList(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to write to. */
    Tcl_Obj *paramList)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);
    Tcl_Obj *oldList;
    Tcl_Size length;



    if (ensemblePtr == NULL) {

	return TCL_ERROR;
    }
    if (paramList == NULL) {
	length = 0;
    } else {
	if (TclListObjLength(interp, paramList, &length) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (length < 1) {
	    paramList = NULL;
	}
    }


    oldList = ensemblePtr->parameterList;
    ensemblePtr->parameterList = paramList;
    if (paramList != NULL) {
	Tcl_IncrRefCount(paramList);
    }
    if (oldList != NULL) {
	TclDecrRefCount(oldList);
    }
    ensemblePtr->numParameters = length;

    /*
     * Trigger an eventual recomputation of the ensemble command set. Note
     * that this is slightly tricky, as it means that we are not actually
     * counting the number of namespace export actions, but it is the simplest
     * way to go!
     */

    ensemblePtr->nsPtr->exportLookupEpoch++;
    BumpEpochIfNecessary(interp, token);









    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetEnsembleMappingDict --

 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetEnsembleMappingDict(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to write to. */
    Tcl_Obj *mapDict)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);
    Tcl_Obj *oldDict;



    if (ensemblePtr == NULL) {

	return TCL_ERROR;
    }
    if (mapDict != NULL) {
	Tcl_Size size;
	int done;
	Tcl_DictSearch search;
	Tcl_Obj *valuePtr;

		Tcl_DictObjDone(&search);
		return TCL_ERROR;
	    }
	    bytes = TclGetString(cmdObjPtr);
	    if (bytes[0] != ':' || bytes[1] != ':') {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(
			"ensemble target is not a fully-qualified command",
			TCL_AUTO_LENGTH));
		Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE",
			"UNQUALIFIED_TARGET", (char *)NULL);
		Tcl_DictObjDone(&search);
		return TCL_ERROR;
	    }
	}

	if (size < 1) {
	    mapDict = NULL;
	}
    }


    oldDict = ensemblePtr->subcommandDict;
    ensemblePtr->subcommandDict = mapDict;
    if (mapDict != NULL) {
	Tcl_IncrRefCount(mapDict);
    }
    if (oldDict != NULL) {
	TclDecrRefCount(oldDict);
    }

    /*
     * Trigger an eventual recomputation of the ensemble command set. Note
     * that this is slightly tricky, as it means that we are not actually
     * counting the number of namespace export actions, but it is the simplest
     * way to go!
     */

    ensemblePtr->nsPtr->exportLookupEpoch++;
    BumpEpochIfNecessary(interp, token);









    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetEnsembleUnknownHandler --

 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetEnsembleUnknownHandler(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to write to. */
    Tcl_Obj *unknownList)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);
    Tcl_Obj *oldList;



    if (ensemblePtr == NULL) {

	return TCL_ERROR;
    }
    if (unknownList != NULL) {
	Tcl_Size length;

	if (TclListObjLength(interp, unknownList, &length) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (length < 1) {
	    unknownList = NULL;
	}
    }


    oldList = ensemblePtr->unknownHandler;
    ensemblePtr->unknownHandler = unknownList;
    if (unknownList != NULL) {
	Tcl_IncrRefCount(unknownList);
    }
    if (oldList != NULL) {
	TclDecrRefCount(oldList);

 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetEnsembleFlags(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to write to. */
    int flags)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);
    int changedFlags = flags ^ ensemblePtr->flags;



    if (ensemblePtr == NULL) {

	return TCL_ERROR;
    }




    /*
     * This API refuses to set the ENSEMBLE_DEAD flag...
     */

    ensemblePtr->flags &= ENSEMBLE_DEAD;
    ensemblePtr->flags |= flags & ~ENSEMBLE_DEAD;

    /*
     * If the ENSEMBLE_COMPILE flag status was changed, install or remove the
     * compiler function and bump the interpreter's compilation epoch so that
     * bytecode gets regenerated.
     */

    if (changedFlags & ENSEMBLE_COMPILE) {

	((Command*) ensemblePtr->token)->compileProc =



		((flags & ENSEMBLE_COMPILE) ? TclCompileEnsemble : NULL);

	((Interp *) interp)->compileEpoch++;

    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleSubcommandList(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    Tcl_Obj **subcmdListPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *subcmdListPtr = ensemblePtr->subcmdList;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleParameterList(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    Tcl_Obj **paramListPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *paramListPtr = ensemblePtr->parameterList;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleMappingDict(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    Tcl_Obj **mapDictPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *mapDictPtr = ensemblePtr->subcommandDict;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleUnknownHandler(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    Tcl_Obj **unknownListPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *unknownListPtr = ensemblePtr->unknownHandler;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleFlags(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    int *flagsPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *flagsPtr = ensemblePtr->flags;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetEnsembleNamespace(
    Tcl_Interp *interp,
    Tcl_Command token,		/* The ensemble command to read from. */
    Tcl_Namespace **namespacePtrPtr)
{

    EnsembleConfig *ensemblePtr = GetEnsembleFromCommand(interp, token);


    if (ensemblePtr == NULL) {




	return TCL_ERROR;
    }


    *namespacePtrPtr = (Tcl_Namespace *) ensemblePtr->nsPtr;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

    Tcl_Interp *interp,		/* Where to do the lookup, and where to write
				 * the errors if TCL_LEAVE_ERR_MSG is set in
				 * the flags. */
    Tcl_Obj *cmdNameObj,	/* Name of command to look up. */
    int flags)			/* Either 0 or TCL_LEAVE_ERR_MSG; other flags
				 * are probably not useful. */
{
    Tcl_Command token;


    token = Tcl_FindCommand(interp, TclGetString(cmdNameObj), NULL, flags);
    if (token == NULL) {
	return NULL;
    }

    if (((Command *) token)->objProc != TclEnsembleImplementationCmd) {
	/*
	 * Reuse existing infrastructure for following import link chains
	 * rather than duplicating it.
	 */

	token = TclGetOriginalCommand(token);

	if (token == NULL ||
		((Command *) token)->objProc != TclEnsembleImplementationCmd) {
	    if (flags & TCL_LEAVE_ERR_MSG) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"\"%s\" is not an ensemble command",
			TclGetString(cmdNameObj)));
		Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "ENSEMBLE",
			TclGetString(cmdNameObj), (char *)NULL);
	    }
	    return NULL;
	}
    }

    return token;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_IsEnsemble --
 *

 *	None
 *
 *----------------------------------------------------------------------
 */

int
Tcl_IsEnsemble(
    Tcl_Command token)		/* The command to check. */
{
    Command *cmdPtr = (Command *) token;

    if (cmdPtr->objProc == TclEnsembleImplementationCmd) {
	return 1;
    }
    cmdPtr = (Command *) TclGetOriginalCommand((Tcl_Command) cmdPtr);

 *
 *	The 'name' parameter may be a single command name or a list if
 *	creating an ensemble subcommand (see the binary implementation).
 *
 *	Currently, the TCL_ENSEMBLE_PREFIX ensemble flag is only used on
 *	top-level ensemble commands.
 *
 *	This code is not safe to run in Safe interpreter after user code has
 *	executed. That's OK right now because it's just used to set up Tcl,
 *	but it means we mustn't expose it at all, not even to Tk (until we can
 *	hide commands in namespaces directly).
 *
 * Results:
 *	Handle for the new ensemble, or NULL on failure.
 *
 * Side effects:
 *	May advance the bytecode compilation epoch.
 *
 *----------------------------------------------------------------------
 */

Tcl_Command
TclMakeEnsemble(
    Tcl_Interp *interp,
    const char *name,		/* The ensemble name (as explained above) */
    const EnsembleImplMap map[])/* The subcommands to create */
{
    Tcl_Command ensemble;
    Tcl_Namespace *ns;
    Tcl_DString buf, hiddenBuf;
    const char **nameParts = NULL;
    const char *cmdName = NULL;
    Tcl_Size i, nameCount = 0;
    int ensembleFlags = 0, hiddenLen;

    /*
     * Construct the path for the ensemble namespace and create it.
     */

    Tcl_DStringInit(&buf);
    Tcl_DStringInit(&hiddenBuf);
    TclDStringAppendLiteral(&hiddenBuf, "tcl:");
    Tcl_DStringAppend(&hiddenBuf, name, TCL_AUTO_LENGTH);
    TclDStringAppendLiteral(&hiddenBuf, ":");
    hiddenLen = Tcl_DStringLength(&hiddenBuf);
    if (name[0] == ':' && name[1] == ':') {
	/*
	 * An absolute name, so use it directly.
	 */

	cmdName = name;
	Tcl_DStringAppend(&buf, name, TCL_AUTO_LENGTH);
	ensembleFlags = TCL_ENSEMBLE_PREFIX;
    } else {
	/*
	 * Not an absolute name, so do munging of it. Note that this treats a
	 * multi-word list differently to a single word.
	 */

	TclDStringAppendLiteral(&buf, "::tcl");

	if (Tcl_SplitList(NULL, name, &nameCount, &nameParts) != TCL_OK) {
	    Tcl_Panic("invalid ensemble name '%s'", name);
	}

	for (i = 0; i < nameCount; ++i) {
	    TclDStringAppendLiteral(&buf, "::");
	    Tcl_DStringAppend(&buf, nameParts[i], TCL_AUTO_LENGTH);
	}
    }

    ns = Tcl_FindNamespace(interp, Tcl_DStringValue(&buf), NULL,
	    TCL_CREATE_NS_IF_UNKNOWN);
    if (!ns) {
	Tcl_Panic("unable to find or create %s namespace!",

	Command *cmdPtr;

	TclDStringAppendLiteral(&buf, "::");
	TclNewObj(mapDict);
	for (i=0 ; map[i].name != NULL ; i++) {
	    TclNewStringObj(toObj, Tcl_DStringValue(&buf),
		    Tcl_DStringLength(&buf));
	    Tcl_AppendToObj(toObj, map[i].name, TCL_AUTO_LENGTH);
	    TclDictPut(NULL, mapDict, map[i].name, toObj);

	    if (map[i].proc || map[i].nreProc) {
		/*
		 * If the command is unsafe, hide it when we're in a safe
		 * interpreter. The code to do this is really hokey! It also
		 * doesn't work properly yet; this function is always
		 * currently called before the safe-interp flag is set so the
		 * Tcl_IsSafe check fails.
		 */

		if (map[i].unsafe && Tcl_IsSafe(interp)) {
		    cmdPtr = (Command *)
			    Tcl_NRCreateCommand(interp, "___tmp", map[i].proc,
			    map[i].nreProc, map[i].clientData, NULL);
		    Tcl_DStringSetLength(&hiddenBuf, hiddenLen);
		    if (Tcl_HideCommand(interp, "___tmp",
			    Tcl_DStringAppend(&hiddenBuf, map[i].name,
				    TCL_AUTO_LENGTH))) {
			Tcl_Panic("%s", Tcl_GetStringResult(interp));
		    }
		} else {
		    /*
		     * Not hidden, so just create it. Yay!
		     */

{
    return Tcl_NRCallObjProc(interp, NsEnsembleImplementationCmdNR,
	    clientData, objc, objv);
}

static int
NsEnsembleImplementationCmdNR(
    void *clientData,		/* The ensemble this is the impl. of. */
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{
    EnsembleConfig *ensemblePtr = (EnsembleConfig *) clientData;
				/* The ensemble itself. */
    Tcl_Obj *prefixObj;		/* An object containing the prefix words of
				 * the command that implements the
				 * subcommand. */
    Tcl_HashEntry *hPtr;	/* Used for efficient lookup of fully
				 * specified but not yet cached command
				 * names. */

	 * No subcommand argument. Make error message.
	 */

	Tcl_DString buf;	/* Message being built */

	Tcl_DStringInit(&buf);
	if (ensemblePtr->parameterList) {

	    TclDStringAppendObj(&buf, ensemblePtr->parameterList);
	    TclDStringAppendLiteral(&buf, " ");
	}
	TclDStringAppendLiteral(&buf, "subcommand ?arg ...?");
	Tcl_WrongNumArgs(interp, 1, objv, Tcl_DStringValue(&buf));
	Tcl_DStringFree(&buf);

	return TCL_ERROR;
    }

    if (ensemblePtr->nsPtr->flags & NS_DEAD) {
	/*
	 * Don't know how we got here, but make things give up quickly.
	 */

	if (!Tcl_InterpDeleted(interp)) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "ensemble activated for deleted namespace",
		    TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "DEAD", (char *)NULL);
	}
	return TCL_ERROR;
    }

    /*
     * If the table of subcommands is valid just lookup up the command there

	 * is an ensembleCmd, just call it.
	 */
	EnsembleCmdRep *ensembleCmd;

	ECRGetInternalRep(subObj, ensembleCmd);
	if (ensembleCmd) {
	    if (ensembleCmd->epoch == ensemblePtr->epoch &&
		    ensembleCmd->token == (Command *) ensemblePtr->token) {
		prefixObj = (Tcl_Obj *) Tcl_GetHashValue(ensembleCmd->hPtr);
		Tcl_IncrRefCount(prefixObj);
		if (ensembleCmd->fix) {
		    TclSpellFix(interp, objv, objc, subIdx, subObj, ensembleCmd->fix);
		}
		goto runResultingSubcommand;
	    }
	}
    } else {
	BuildEnsembleConfig(ensemblePtr);
	ensemblePtr->epoch = ensemblePtr->nsPtr->exportLookupEpoch;
    }

    /*
     * Look in the hashtable for the named subcommand.  This is the fastest
     * path if there is no cache in operation.
     */

    hPtr = Tcl_FindHashEntry(&ensemblePtr->subcommandTable,
	    TclGetString(subObj));
    if (hPtr != NULL) {

	/*
	 * Cache ensemble in the subcommand object for later.
	 */

	MakeCachedEnsembleCommand(subObj, ensemblePtr, hPtr, NULL);
    } else if (!(ensemblePtr->flags & TCL_ENSEMBLE_PREFIX)) {
	/*

		    fullName);
	}

	/*
	 * Record the spelling correction for usage message.
	 */

	fix = Tcl_NewStringObj(fullName, TCL_AUTO_LENGTH);

	/*
	 * Cache for later in the subcommand object.
	 */

	MakeCachedEnsembleCommand(subObj, ensemblePtr, hPtr, fix);
	TclSpellFix(interp, objv, objc, subIdx, subObj, fix);
    }

    prefixObj = (Tcl_Obj *) Tcl_GetHashValue(hPtr);
    Tcl_IncrRefCount(prefixObj);
  runResultingSubcommand:

    /*
     * Execute the subcommand by populating an array of objects, which might
     * not be the same length as the number of arguments to this ensemble
     * command, and then handing it to the main command-lookup engine. In

	/*
	 * Hand off to the target command.
	 */

	TclSkipTailcall(interp);
	TclListObjGetElements(NULL, copyPtr, &copyObjc, &copyObjv);
	((Interp *) interp)->lookupNsPtr = ensemblePtr->nsPtr;
	return TclNREvalObjv(interp, copyObjc, copyObjv, TCL_EVAL_INVOKE, NULL);
    }

  unknownOrAmbiguousSubcommand:
    /*
     * The named subcommand did not match any exported command. If there is a
     * handler registered unknown subcommands, call it, but not more than once

		ensemblePtr->nsPtr->fullName));
	return TCL_ERROR;
    }
    errorObj = Tcl_ObjPrintf("unknown%s subcommand \"%s\": must be ",
	    (ensemblePtr->flags & TCL_ENSEMBLE_PREFIX ? " or ambiguous" : ""),
	    TclGetString(subObj));
    if (ensemblePtr->subcommandTable.numEntries == 1) {
	Tcl_AppendToObj(errorObj, ensemblePtr->subcommandArrayPtr[0],
		TCL_AUTO_LENGTH);
    } else {
	Tcl_Size i;

	for (i=0 ; i<ensemblePtr->subcommandTable.numEntries-1 ; i++) {
	    Tcl_AppendToObj(errorObj, ensemblePtr->subcommandArrayPtr[i],
		    TCL_AUTO_LENGTH);
	    Tcl_AppendToObj(errorObj, ", ", 2);
	}
	Tcl_AppendPrintfToObj(errorObj, "or %s",
		ensemblePtr->subcommandArrayPtr[i]);
    }
    Tcl_SetObjResult(interp, errorObj);
    return TCL_ERROR;

	}
    }

    search = iPtr->ensembleRewrite.sourceObjs;
    if (search[0] == NULL) {
	store = (Tcl_Obj **) search[2];
    }  else {
	Tcl_Obj **tmp = (Tcl_Obj **) ckalloc(3 * sizeof(Tcl_Obj *));

	store = (Tcl_Obj **) ckalloc(size * sizeof(Tcl_Obj *));
	memcpy(store, iPtr->ensembleRewrite.sourceObjs,
		size * sizeof(Tcl_Obj *));

	/*
	 * Awful casting abuse here! Note that the NULL in the first element
	 * indicates that the initial objects are a raw array in the second
	 * element and the rewritten ones are a raw array in the third.

    }

    store[idx] = fix;
    Tcl_IncrRefCount(fix);
    TclNRAddCallback(interp, TclNRReleaseValues, fix, NULL, NULL, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * TclEnsembleGetRewriteValues --
 *
 *	Get the original arguments to the current command before any rewrite
 *	rules (from aliases, ensembles, and method forwards) were applied.
 *
 *----------------------------------------------------------------------
 */
Tcl_Obj *const *
TclEnsembleGetRewriteValues(
    Tcl_Interp *interp)		/* Current interpreter. */

{
    Interp *iPtr = (Interp *) interp;
    Tcl_Obj *const *origObjv = iPtr->ensembleRewrite.sourceObjs;

    if (origObjv[0] == NULL) {
	origObjv = (Tcl_Obj *const *) origObjv[2];
    }
    return origObjv;
}

/*
 *----------------------------------------------------------------------
 *
 * TclFetchEnsembleRoot --
 *
 *	Returns the root of ensemble rewriting, if any.
 *	If no root exists, returns objv instead.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *const *
TclFetchEnsembleRoot(
    Tcl_Interp *interp,
    Tcl_Obj *const *objv,
    Tcl_Size objc,
    Tcl_Size *objcPtr)
{
    Tcl_Obj *const *sourceObjs;
    Interp *iPtr = (Interp *) interp;

    if (iPtr->ensembleRewrite.sourceObjs) {
	*objcPtr = objc + iPtr->ensembleRewrite.numRemovedObjs
		- iPtr->ensembleRewrite.numInsertedObjs;
	if (iPtr->ensembleRewrite.sourceObjs[0] == NULL) {
	    sourceObjs = (Tcl_Obj *const *) iPtr->ensembleRewrite.sourceObjs[1];
	} else {
	    sourceObjs = iPtr->ensembleRewrite.sourceObjs;
	}
	return sourceObjs;
    }
    *objcPtr = objc;
    return objv;

 *
 * ----------------------------------------------------------------------
 */

static inline int
EnsembleUnknownCallback(
    Tcl_Interp *interp,
    EnsembleConfig *ensemblePtr,/* The ensemble structure. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[],	/* Actual arguments. */
    Tcl_Obj **prefixObjPtr)	/* Where to write the prefix suggested by the
				 * unknown callback. Must not be NULL. Only has
				 * a meaningful value on TCL_OK. */
{
    Tcl_Size paramc;
    int result;
    Tcl_Size i, prefixObjc;
    Tcl_Obj **paramv, *unknownCmd, *ensObj;

    /*

    Tcl_Preserve(ensemblePtr);
    TclSkipTailcall(interp);
    result = Tcl_EvalObjv(interp, paramc, paramv, 0);
    if ((result == TCL_OK) && (ensemblePtr->flags & ENSEMBLE_DEAD)) {
	if (!Tcl_InterpDeleted(interp)) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "unknown subcommand handler deleted its ensemble",
		    TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp, "TCL", "ENSEMBLE", "UNKNOWN_DELETED",
		    (char *)NULL);
	}
	result = TCL_ERROR;
    }
    Tcl_Release(ensemblePtr);

     * Convert exceptional result to an error.
     */

    if (!Tcl_InterpDeleted(interp)) {
	if (result != TCL_ERROR) {
	    Tcl_ResetResult(interp);
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "unknown subcommand handler returned bad code: ",
		    TCL_AUTO_LENGTH));
	    switch (result) {
	    case TCL_RETURN:
		Tcl_AppendToObj(Tcl_GetObjResult(interp), "return",
			TCL_AUTO_LENGTH);
		break;
	    case TCL_BREAK:
		Tcl_AppendToObj(Tcl_GetObjResult(interp), "break",
			TCL_AUTO_LENGTH);
		break;
	    case TCL_CONTINUE:
		Tcl_AppendToObj(Tcl_GetObjResult(interp), "continue",
			TCL_AUTO_LENGTH);
		break;
	    default:
		Tcl_AppendPrintfToObj(Tcl_GetObjResult(interp), "%d", result);
	    }
	    Tcl_AddErrorInfo(interp, "\n    result of "
		    "ensemble unknown subcommand handler: ");
	    Tcl_AppendObjToErrorInfo(interp, unknownCmd);

 *	ensembleCmd.
 *
 *----------------------------------------------------------------------
 */

static void
MakeCachedEnsembleCommand(
    Tcl_Obj *objPtr,		/* Object to cache in. */
    EnsembleConfig *ensemblePtr,/* Ensemble implementation. */
    Tcl_HashEntry *hPtr,	/* What to cache; what the object maps to. */
    Tcl_Obj *fix)		/* Spelling correction for later error, or NULL
				 * if no correction. */
{
    EnsembleCmdRep *ensembleCmd;

    ECRGetInternalRep(objPtr, ensembleCmd);
    if (ensembleCmd) {
	TclCleanupCommandMacro(ensembleCmd->token);
	if (ensembleCmd->fix) {
	    Tcl_DecrRefCount(ensembleCmd->fix);
	}
    } else {
	/*
	 * Replace any old internal representation with a new one.
	 */

	ensembleCmd = (EnsembleCmdRep *) ckalloc(sizeof(EnsembleCmdRep));
	ECRSetInternalRep(objPtr, ensembleCmd);
    }

    /*
     * Populate the internal rep.
     */

 *	Memory is eventually deallocated.
 *
 *----------------------------------------------------------------------
 */

static void
ClearTable(
    EnsembleConfig *ensemblePtr)/* Ensemble to clear table of. */
{
    Tcl_HashTable *hash = &ensemblePtr->subcommandTable;

    if (hash->numEntries != 0) {
	Tcl_HashSearch search;
	Tcl_HashEntry *hPtr = Tcl_FirstHashEntry(hash, &search);

	while (hPtr != NULL) {
	    Tcl_Obj *prefixObj = (Tcl_Obj *) Tcl_GetHashValue(hPtr);
	    Tcl_DecrRefCount(prefixObj);
	    hPtr = Tcl_NextHashEntry(&search);
	}
	ckfree((char *) ensemblePtr->subcommandArrayPtr);
    }
    Tcl_DeleteHashTable(hash);
}

static void
DeleteEnsembleConfig(
    void *clientData)		/* Ensemble to delete. */
{
    EnsembleConfig *ensemblePtr = (EnsembleConfig *) clientData;
    Namespace *nsPtr = ensemblePtr->nsPtr;

    /* Unlink from the ensemble chain if it not already marked as unlinked. */

    if (ensemblePtr->next != ensemblePtr) {
	EnsembleConfig *ensPtr = (EnsembleConfig *) nsPtr->ensembles;

 *	may be an expensive operation.
 *
 *----------------------------------------------------------------------
 */

static void
BuildEnsembleConfig(
    EnsembleConfig *ensemblePtr)/* Ensemble to set up. */
{
    Tcl_HashSearch search;	/* Used for scanning the commands in
				 * the namespace for this ensemble. */
    Tcl_Size i, j;
    int isNew;
    Tcl_HashTable *hash = &ensemblePtr->subcommandTable;
    Tcl_HashEntry *hPtr;
    Tcl_Obj *mapDict = ensemblePtr->subcommandDict;
    Tcl_Obj *subList = ensemblePtr->subcmdList;

    ClearTable(ensemblePtr);
    Tcl_InitHashTable(hash, TCL_STRING_KEYS);

    if (subList) {
	Tcl_Size subc;
	Tcl_Obj **subv, *target, *cmdObj, *cmdPrefixObj;
	const char *name;

	/*
	 * There is a list of exactly what subcommands go in the table.
	 * Determine the target for each.
	 */

	TclListObjGetElements(NULL, subList, &subc, &subv);
	if (subList == mapDict) {
	    /*
	     * Unusual case where explicit list of subcommands is same value
	     * as the dict mapping to targets.
	     */

	    for (i = 0; i < subc; i += 2) {
		name = TclGetString(subv[i]);
		hPtr = Tcl_CreateHashEntry(hash, name, &isNew);
		if (!isNew) {
		    cmdObj = (Tcl_Obj *) Tcl_GetHashValue(hPtr);
		    Tcl_DecrRefCount(cmdObj);
		}
		Tcl_SetHashValue(hPtr, subv[i + 1]);
		Tcl_IncrRefCount(subv[i + 1]);

		name = TclGetString(subv[i + 1]);
		hPtr = Tcl_CreateHashEntry(hash, name, &isNew);
		if (isNew) {
		    cmdObj = Tcl_NewStringObj(name, TCL_AUTO_LENGTH);
		    cmdPrefixObj = Tcl_NewListObj(1, &cmdObj);
		    Tcl_SetHashValue(hPtr, cmdPrefixObj);
		    Tcl_IncrRefCount(cmdPrefixObj);
		}
	    }
	} else {
	    /*
	     * Usual case where we can freely act on the list and dict.
	     */

	    for (i = 0; i < subc; i++) {
		name = TclGetString(subv[i]);
		hPtr = Tcl_CreateHashEntry(hash, name, &isNew);
		if (!isNew) {
		    continue;
		}

		/*
		 * Lookup target in the dictionary.
		 */

		if (mapDict) {
		    Tcl_DictObjGet(NULL, mapDict, subv[i], &target);
		    if (target) {
			Tcl_SetHashValue(hPtr, target);
			Tcl_IncrRefCount(target);
			continue;
		    }
		}

		/*
		 * Target was not in the dictionary.  Map onto the namespace.
		 * In this case there is no guarantee that the command is
		 * actually there.  It is the responsibility of the programmer
		 * (or [::unknown] of course) to provide the procedure.
		 */

		cmdObj = Tcl_NewStringObj(name, TCL_AUTO_LENGTH);
		cmdPrefixObj = Tcl_NewListObj(1, &cmdObj);
		Tcl_SetHashValue(hPtr, cmdPrefixObj);
		Tcl_IncrRefCount(cmdPrefixObj);
	    }
	}
    } else if (mapDict) {
	/*
	 * No subcmd list, but there is a mapping dictionary, so use
	 * the keys of that. Convert the contents of the dictionary into the
	 * form required for the internal hashtable of the ensemble.
	 */

	Tcl_DictSearch dictSearch;
	Tcl_Obj *keyObj, *valueObj;
	int done;

	Tcl_DictObjFirst(NULL, ensemblePtr->subcommandDict, &dictSearch,
		&keyObj, &valueObj, &done);
	while (!done) {
	    const char *name = TclGetString(keyObj);

	    hPtr = Tcl_CreateHashEntry(hash, name, &isNew);
	    Tcl_SetHashValue(hPtr, valueObj);
	    Tcl_IncrRefCount(valueObj);
	    Tcl_DictObjNext(&dictSearch, &keyObj, &valueObj, &done);
	}
    } else {
	/*
	 * Use the array of patterns and the hash table whose keys are the
	 * commands exported by the namespace.  The corresponding values do not
	 * matter here.  Filter the commands in the namespace against the
	 * patterns in the export list to find out what commands are actually
	 * exported. Use an intermediate hash table to make memory management
	 * easier and to make exact matching much easier.
	 *
	 * Suggestion for future enhancement: Compute the unique prefixes and
	 * place them in the hash too for even faster matching.
	 */

	hPtr = Tcl_FirstHashEntry(&ensemblePtr->nsPtr->cmdTable, &search);
	for (; hPtr!= NULL ; hPtr=Tcl_NextHashEntry(&search)) {
	    char *nsCmdName = (char *)	/* Name of command in namespace. */
		    Tcl_GetHashKey(&ensemblePtr->nsPtr->cmdTable, hPtr);

	    for (i=0 ; i<ensemblePtr->nsPtr->numExportPatterns ; i++) {
		if (Tcl_StringMatch(nsCmdName,
			ensemblePtr->nsPtr->exportArrayPtr[i])) {
		    hPtr = Tcl_CreateHashEntry(hash, nsCmdName, &isNew);

		    /*

     * the error message either.
     *
     * Do this by filling an array with the names:  Use the hash keys
     * directly to save a copy since any time we change the array we change
     * the hash too, and vice versa, and run quicksort over the array.
     */

    ensemblePtr->subcommandArrayPtr = (char **)
	    ckalloc(sizeof(char *) * hash->numEntries);

    /*
     * Fill the array from both ends as this reduces the likelihood of
     * performance problems in qsort(). This makes this code much more opaque,
     * but the naive alternatve:
     *
     * for (hPtr=Tcl_FirstHashEntry(hash,&search),i=0 ;

     * to have awful runtime behaviour.
     */

    i = 0;
    j = hash->numEntries;
    hPtr = Tcl_FirstHashEntry(hash, &search);
    while (hPtr != NULL) {
	ensemblePtr->subcommandArrayPtr[i++] = (char *)
		Tcl_GetHashKey(hash, hPtr);
	hPtr = Tcl_NextHashEntry(&search);
	if (hPtr == NULL) {
	    break;
	}
	ensemblePtr->subcommandArrayPtr[--j] = (char *)
		Tcl_GetHashKey(hash, hPtr);
	hPtr = Tcl_NextHashEntry(&search);
    }
    if (hash->numEntries > 1) {
	qsort(ensemblePtr->subcommandArrayPtr, hash->numEntries,
		sizeof(char *), NsEnsembleStringOrder);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NsEnsembleStringOrder --
 *
 *	Helper to for use with qsort() that compares two array entries that
 *	contain string pointers.
 *
 * Results:
 *	-1 if the first string is smaller, 1 if the second string is smaller,
 *	and 0 if they are equal.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
NsEnsembleStringOrder(
    const void *strPtr1,	/* Points to first array entry */
    const void *strPtr2)	/* Points to second array entry */
{
    return strcmp(*(const char **)strPtr1, *(const char **)strPtr2);
}

/*
 *----------------------------------------------------------------------
 *

static void
DupEnsembleCmdRep(
    Tcl_Obj *objPtr,
    Tcl_Obj *copyPtr)
{
    EnsembleCmdRep *ensembleCmd;
    EnsembleCmdRep *ensembleCopy = (EnsembleCmdRep *)
	    ckalloc(sizeof(EnsembleCmdRep));

    ECRGetInternalRep(objPtr, ensembleCmd);
    ECRSetInternalRep(copyPtr, ensembleCopy);

    ensembleCopy->epoch = ensembleCmd->epoch;
    ensembleCopy->token = ensembleCmd->token;
    ensembleCopy->token->refCount++;

    oldCmdPtr = cmdPtr;
    Tcl_IncrRefCount(targetCmdObj);
    newCmdPtr = (Command *) Tcl_GetCommandFromObj(interp, targetCmdObj);
    TclDecrRefCount(targetCmdObj);
    if (newCmdPtr == NULL || Tcl_IsSafe(interp)
	    || newCmdPtr->nsPtr->flags & NS_SUPPRESS_COMPILATION
	    || newCmdPtr->flags & CMD_HAS_EXEC_TRACES
	    || ((Interp *) interp)->flags & DONT_COMPILE_CMDS_INLINE) {
	/*
	 * Maps to an undefined command or a command without a compiler.
	 * Cannot compile.
	 */

	goto cleanup;
    }

    }

    /*
     * Throw out any line information generated by the failed compile attempt.
     */

    while (mapPtr->nuloc > eclIndex + 1) {
	mapPtr->nuloc--;
	ckfree(mapPtr->loc[mapPtr->nuloc].line);
	mapPtr->loc[mapPtr->nuloc].line = NULL;
    }

    /*
     * Reset the index of next command.  Toss out any from failed nested
     * partial compiles.
     */

     * difference. Hence the call to TclContinuationsEnterDerived...
     */

    TclListObjGetElements(NULL, replacements, &numWords, &words);
    for (i = 0, tokPtr = parsePtr->tokenPtr; i < parsePtr->numWords;
	    i++, tokPtr = TokenAfter(tokPtr)) {
	if (i > 0 && i <= numWords) {
	    bytes = TclGetStringFromObj(words[i - 1], &length);
	    PushLiteral(envPtr, bytes, length);
	    continue;
	}

	SetLineInformation(i);
	if (tokPtr->type == TCL_TOKEN_SIMPLE_WORD) {
	    int literal = TclRegisterLiteral(envPtr,

    TclEmitPush(cmdLit, envPtr);
    TclDecrRefCount(objPtr);

    /*
     * Do the replacing dispatch.
     */

    TclEmitInvoke(envPtr, INST_INVOKE_REPLACE, parsePtr->numWords,
	    numWords + 1);
}

/*
 * Helpers that do issuing of instructions for commands that "don't have
 * compilers" (well, they do; these). They all work by just generating base
 * code to invoke the command; they're intended for ensemble subcommands so
 * that the costs of INST_INVOKE_REPLACE can be avoided where we can work out

				 * values. */
    int unused1;		/* No longer used (was termOffset) */
    LiteralTable literalTable;	/* Contains LiteralEntry's describing all Tcl
				 * objects holding literals of scripts
				 * compiled by the interpreter. Indexed by the
				 * string representations of literals. Used to
				 * avoid creating duplicate objects. */
    Tcl_Size compileEpoch;	/* Holds the current "compilation epoch" for
				 * this interpreter. This is incremented to
				 * invalidate existing ByteCodes when, e.g., a
				 * command with a compile procedure is
				 * redefined. */
    Proc *compiledProcPtr;	/* If a procedure is being compiled, a pointer
				 * to its Proc structure; otherwise, this is
				 * NULL. Set by ObjInterpProc in tclProc.c and
				 * used by tclCompile.c to process local
				 * variables appropriately. */
    ResolverScheme *resolverPtr;/* Linked list of name resolution schemes

				 * added to this interpreter. Schemes are
				 * added and removed by calling
				 * Tcl_AddInterpResolvers and
				 * Tcl_RemoveInterpResolver respectively. */
    Tcl_Obj *scriptFile;	/* NULL means there is no nested source
				 * command active; otherwise this points to
				 * pathPtr of the file being sourced. */

    ActiveCommandTrace *activeCmdTracePtr;
				/* First in list of active command traces for
				 * interp, or NULL if no active traces. */
    ActiveInterpTrace *activeInterpTracePtr;
				/* First in list of active traces for interp,
				 * or NULL if no active traces. */

    Tcl_Size tracesForbiddingInline;
				/* Count of traces (in the list headed by
				 * tracePtr) that forbid inline bytecode
				 * compilation. */

    /*
     * Fields used to manage extensible return options (TIP 90).
     */

				 * set. */
	int granularityTicker;	/* Counter used to determine how often to
				 * check the limits. */
	int exceeded;		/* Which limits have been exceeded, described
				 * as flag values the same as the 'active'
				 * field. */

	Tcl_Size cmdCount;	/* Limit for how many commands to execute in
				 * the interpreter. */
	LimitHandler *cmdHandlers;
				/* Handlers to execute when the limit is
				 * reached. */
	int cmdGranularity;	/* Mod factor used to determine how often to
				 * evaluate the limit check. */

    struct {
	Tcl_Obj *const *sourceObjs;
				/* What arguments were actually input into the
				 * *root* ensemble command? (Nested ensembles
				 * don't rewrite this.) NULL if we're not
				 * processing an ensemble. */
	Tcl_Size numRemovedObjs;/* How many arguments have been stripped off
				 * because of ensemble processing. */
	Tcl_Size numInsertedObjs;
				/* How many of the current arguments were
				 * inserted by an ensemble. */
    } ensembleRewrite;

    /*
     * TIP #219: Global info for the I/O system.
     */

    ContLineLoc *scriptCLLocPtr;/* This table points to the location data for
				 * invisible continuation lines in the script,
				 * if any. This pointer is set by the function
				 * TclEvalObjEx() in file "tclBasic.c", and
				 * used by function ...() in the same file.
				 * It does for the eval/direct path of script
				 * execution what CompileEnv.clLoc does for
				 * the bytecode compiler. */

    /*
     * TIP #268. The currently active selection mode, i.e. the package require
     * preferences.
     */

    int packagePrefer;		/* Current package selection mode. */