/*
 * tclBasic.c --
 *
 *	Contains the basic facilities for TCL command interpretation,
 *	including interpreter creation and deletion, command creation and
 *	deletion, and command/script execution.
 *
 * Copyright (c) 1987-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 * Copyright (c) 2001, 2002 by Kevin B. Kenny.  All rights reserved.
 * Copyright (c) 2007 Daniel A. Steffen <das@users.sourceforge.net>
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclBasic.c,v 1.295.2.16 2009/11/10 20:19:02 dgp Exp $
 */

#include "tclInt.h"
#include "tclCompile.h"
#include <float.h>
#include <limits.h>
#include <math.h>
#include "tommath.h"

/*
 * Determine whether we're using IEEE floating point
 */

#if (FLT_RADIX == 2) && (DBL_MANT_DIG == 53) && (DBL_MAX_EXP == 1024)
#   define IEEE_FLOATING_POINT
/* Largest odd integer that can be represented exactly in a double */
#   define MAX_EXACT 9007199254740991.0
#endif

/*
 * The following structure defines the client data for a math function
 * registered with Tcl_CreateMathFunc
 */

typedef struct OldMathFuncData {
    Tcl_MathProc *proc;		/* Handler function */
    int numArgs;		/* Number of args expected */
    Tcl_ValueType *argTypes;	/* Types of the args */
    ClientData clientData;	/* Client data for the handler function */
} OldMathFuncData;

/*
 * Static functions in this file:
 */

static char *	CallCommandTraces(Interp *iPtr, Command *cmdPtr,
		    const char *oldName, const char *newName, int flags);
static int	CheckDoubleResult(Tcl_Interp *interp, double dResult);
static void	DeleteInterpProc(Tcl_Interp *interp);
static void	DeleteOpCmdClientData(ClientData clientData);
static Tcl_Obj *GetCommandSource(Interp *iPtr, const char *command,
	            int numChars, int objc, Tcl_Obj *const objv[]);
static void	ProcessUnexpectedResult(Tcl_Interp *interp, int returnCode);
static int	OldMathFuncProc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static void	OldMathFuncDeleteProc(ClientData clientData);
static int	ExprAbsFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprBinaryFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprBoolFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprCeilFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprDoubleFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprEntierFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprFloorFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprIntFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprIsqrtFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprRandFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprRoundFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprSqrtFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprSrandFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprUnaryFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static int	ExprWideFunc(ClientData clientData, Tcl_Interp *interp,
		    int argc, Tcl_Obj *const *objv);
static void	MathFuncWrongNumArgs(Tcl_Interp *interp, int expected,
		    int actual, Tcl_Obj *const *objv);
#ifdef USE_DTRACE
static int	DTraceObjCmd(ClientData dummy, Tcl_Interp *interp, int objc,
		    Tcl_Obj *const objv[]);
#endif

extern TclStubs tclStubs;

/*
 * The following structure define the commands in the Tcl core.
 */

typedef struct {
    const char *name;		/* Name of object-based command. */
    Tcl_ObjCmdProc *objProc;	/* Object-based function for command. */
    CompileProc *compileProc;	/* Function called to compile command. */
    int isSafe;			/* If non-zero, command will be present in
				 * safe interpreter. Otherwise it will be
				 * hidden. */
} CmdInfo;

/*
 * The built-in commands, and the functions that implement them:
 */

static const CmdInfo builtInCmds[] = {
    /*
     * Commands in the generic core.
     */

    {"append",		Tcl_AppendObjCmd,	TclCompileAppendCmd,	1},
    {"apply",		Tcl_ApplyObjCmd,	NULL,			1},
    {"array",		Tcl_ArrayObjCmd,	NULL,			1},
    {"binary",		Tcl_BinaryObjCmd,	NULL,			1},
    {"break",		Tcl_BreakObjCmd,	TclCompileBreakCmd,	1},
#ifndef EXCLUDE_OBSOLETE_COMMANDS
    {"case",		Tcl_CaseObjCmd,		NULL,			1},
#endif
    {"catch",		Tcl_CatchObjCmd,	TclCompileCatchCmd,	1},
    {"concat",		Tcl_ConcatObjCmd,	NULL,			1},
    {"continue",	Tcl_ContinueObjCmd,	TclCompileContinueCmd,	1},
    {"error",		Tcl_ErrorObjCmd,	NULL,			1},
    {"eval",		Tcl_EvalObjCmd,		NULL,			1},
    {"expr",		Tcl_ExprObjCmd,		TclCompileExprCmd,	1},
    {"for",		Tcl_ForObjCmd,		TclCompileForCmd,	1},
    {"foreach",		Tcl_ForeachObjCmd,	TclCompileForeachCmd,	1},
    {"format",		Tcl_FormatObjCmd,	NULL,			1},
    {"global",		Tcl_GlobalObjCmd,	TclCompileGlobalCmd,	1},
    {"if",		Tcl_IfObjCmd,		TclCompileIfCmd,	1},
    {"incr",		Tcl_IncrObjCmd,		TclCompileIncrCmd,	1},
    {"join",		Tcl_JoinObjCmd,		NULL,			1},
    {"lappend",		Tcl_LappendObjCmd,	TclCompileLappendCmd,	1},
    {"lassign",		Tcl_LassignObjCmd,	TclCompileLassignCmd,	1},
    {"lindex",		Tcl_LindexObjCmd,	TclCompileLindexCmd,	1},
    {"linsert",		Tcl_LinsertObjCmd,	NULL,			1},
    {"list",		Tcl_ListObjCmd,		TclCompileListCmd,	1},
    {"llength",		Tcl_LlengthObjCmd,	TclCompileLlengthCmd,	1},
    {"lrange",		Tcl_LrangeObjCmd,	NULL,			1},
    {"lrepeat",		Tcl_LrepeatObjCmd,	NULL,			1},
    {"lreplace",	Tcl_LreplaceObjCmd,	NULL,			1},
    {"lreverse",	Tcl_LreverseObjCmd,	NULL,			1},
    {"lsearch",		Tcl_LsearchObjCmd,	NULL,			1},
    {"lset",		Tcl_LsetObjCmd,		TclCompileLsetCmd,	1},
    {"lsort",		Tcl_LsortObjCmd,	NULL,			1},
    {"namespace",	Tcl_NamespaceObjCmd,	TclCompileNamespaceCmd,	1},
    {"package",		Tcl_PackageObjCmd,	NULL,			1},
    {"proc",		Tcl_ProcObjCmd,		NULL,			1},
    {"regexp",		Tcl_RegexpObjCmd,	TclCompileRegexpCmd,	1},
    {"regsub",		Tcl_RegsubObjCmd,	NULL,			1},
    {"rename",		Tcl_RenameObjCmd,	NULL,			1},
    {"return",		Tcl_ReturnObjCmd,	TclCompileReturnCmd,	1},
    {"scan",		Tcl_ScanObjCmd,		NULL,			1},
    {"set",		Tcl_SetObjCmd,		TclCompileSetCmd,	1},
    {"split",		Tcl_SplitObjCmd,	NULL,			1},
    {"subst",		Tcl_SubstObjCmd,	NULL,			1},
    {"switch",		Tcl_SwitchObjCmd,	TclCompileSwitchCmd,	1},
    {"trace",		Tcl_TraceObjCmd,	NULL,			1},
    {"unset",		Tcl_UnsetObjCmd,	NULL,			1},
    {"uplevel",		Tcl_UplevelObjCmd,	NULL,			1},
    {"upvar",		Tcl_UpvarObjCmd,	TclCompileUpvarCmd,	1},
    {"variable",	Tcl_VariableObjCmd,	TclCompileVariableCmd,	1},
    {"while",		Tcl_WhileObjCmd,	TclCompileWhileCmd,	1},

    /*
     * Commands in the OS-interface. Note that many of these are unsafe.
     */

    {"after",		Tcl_AfterObjCmd,	NULL,			1},
    {"cd",		Tcl_CdObjCmd,		NULL,			0},
    {"close",		Tcl_CloseObjCmd,	NULL,			1},
    {"eof",		Tcl_EofObjCmd,		NULL,			1},
    {"encoding",	Tcl_EncodingObjCmd,	NULL,			0},
    {"exec",		Tcl_ExecObjCmd,		NULL,			0},
    {"exit",		Tcl_ExitObjCmd,		NULL,			0},
    {"fblocked",	Tcl_FblockedObjCmd,	NULL,			1},
    {"fconfigure",	Tcl_FconfigureObjCmd,	NULL,			0},
    {"fcopy",		Tcl_FcopyObjCmd,	NULL,			1},
    {"file",		Tcl_FileObjCmd,		NULL,			0},
    {"fileevent",	Tcl_FileEventObjCmd,	NULL,			1},
    {"flush",		Tcl_FlushObjCmd,	NULL,			1},
    {"gets",		Tcl_GetsObjCmd,		NULL,			1},
    {"glob",		Tcl_GlobObjCmd,		NULL,			0},
    {"load",		Tcl_LoadObjCmd,		NULL,			0},
    {"open",		Tcl_OpenObjCmd,		NULL,			0},
    {"pid",		Tcl_PidObjCmd,		NULL,			1},
    {"puts",		Tcl_PutsObjCmd,		NULL,			1},
    {"pwd",		Tcl_PwdObjCmd,		NULL,			0},
    {"read",		Tcl_ReadObjCmd,		NULL,			1},
    {"seek",		Tcl_SeekObjCmd,		NULL,			1},
    {"socket",		Tcl_SocketObjCmd,	NULL,			0},
    {"source",		Tcl_SourceObjCmd,	NULL,			0},
    {"tell",		Tcl_TellObjCmd,		NULL,			1},
    {"time",		Tcl_TimeObjCmd,		NULL,			1},
    {"unload",		Tcl_UnloadObjCmd,	NULL,			0},
    {"update",		Tcl_UpdateObjCmd,	NULL,			1},
    {"vwait",		Tcl_VwaitObjCmd,	NULL,			1},
    {NULL,		NULL,			NULL,			0}
};

/*
 * Math functions. All are safe.
 */

typedef struct {
    const char *name;		/* Name of the function. The full name is
				 * "::tcl::mathfunc::<name>".  */
    Tcl_ObjCmdProc *objCmdProc;	/* Function that evaluates the function */
    ClientData clientData;	/* Client data for the function */
} BuiltinFuncDef;
static const BuiltinFuncDef BuiltinFuncTable[] = {
    { "abs",	ExprAbsFunc,	NULL 			},
    { "acos",	ExprUnaryFunc,	(ClientData) acos 	},
    { "asin",	ExprUnaryFunc,	(ClientData) asin 	},
    { "atan",	ExprUnaryFunc,	(ClientData) atan 	},
    { "atan2",	ExprBinaryFunc,	(ClientData) atan2 	},
    { "bool",	ExprBoolFunc,	NULL			},
    { "ceil",	ExprCeilFunc,	NULL		 	},
    { "cos",	ExprUnaryFunc,	(ClientData) cos 	},
    { "cosh",	ExprUnaryFunc,	(ClientData) cosh	},
    { "double",	ExprDoubleFunc,	NULL			},
    { "entier",	ExprEntierFunc,	NULL			},
    { "exp",	ExprUnaryFunc,	(ClientData) exp	},
    { "floor",	ExprFloorFunc,	NULL		 	},
    { "fmod",	ExprBinaryFunc,	(ClientData) fmod	},
    { "hypot",	ExprBinaryFunc,	(ClientData) hypot 	},
    { "int",	ExprIntFunc,	NULL			},
    { "isqrt",	ExprIsqrtFunc,	NULL			},
    { "log",	ExprUnaryFunc,	(ClientData) log 	},
    { "log10",	ExprUnaryFunc,	(ClientData) log10 	},
    { "pow",	ExprBinaryFunc,	(ClientData) pow 	},
    { "rand",	ExprRandFunc,	NULL			},
    { "round",	ExprRoundFunc,	NULL			},
    { "sin",	ExprUnaryFunc,	(ClientData) sin 	},
    { "sinh",	ExprUnaryFunc,	(ClientData) sinh 	},
    { "sqrt",	ExprSqrtFunc,	NULL		 	},
    { "srand",	ExprSrandFunc,	NULL			},
    { "tan",	ExprUnaryFunc,	(ClientData) tan 	},
    { "tanh",	ExprUnaryFunc,	(ClientData) tanh 	},
    { "wide",	ExprWideFunc,	NULL		 	},
    { NULL, NULL, NULL }
};

/*
 * TIP#174's math operators. All are safe.
 */

typedef struct {
    const char *name;		/* Name of object-based command. */
    Tcl_ObjCmdProc *objProc;	/* Object-based function for command. */
    CompileProc *compileProc;	/* Function called to compile command. */
    union {
	int numArgs;
	int identity;
    } i;
    const char *expected;	/* For error message, what argument(s)
				 * were expected. */
} OpCmdInfo;
static const OpCmdInfo mathOpCmds[] = {
    { "~",	TclSingleOpCmd,		TclCompileInvertOpCmd,
		/* numArgs */ {1},	"integer"},
    { "!",	TclSingleOpCmd,		TclCompileNotOpCmd,
		/* numArgs */ {1},	"boolean"},
    { "+",	TclVariadicOpCmd,	TclCompileAddOpCmd,
		/* identity */ {0},	NULL},
    { "*",	TclVariadicOpCmd,	TclCompileMulOpCmd,
		/* identity */ {1},	NULL},
    { "&",	TclVariadicOpCmd,	TclCompileAndOpCmd,
		/* identity */ {-1},	NULL},
    { "|",	TclVariadicOpCmd,	TclCompileOrOpCmd,
		/* identity */ {0},	NULL},
    { "^",	TclVariadicOpCmd,	TclCompileXorOpCmd,
		/* identity */ {0},	NULL},
    { "**",	TclVariadicOpCmd,	TclCompilePowOpCmd,
		/* identity */ {1},	NULL},
    { "<<",	TclSingleOpCmd,		TclCompileLshiftOpCmd,
		/* numArgs */ {2},	"integer shift"},
    { ">>",	TclSingleOpCmd,		TclCompileRshiftOpCmd,
		/* numArgs */ {2},	"integer shift"},
    { "%",	TclSingleOpCmd,		TclCompileModOpCmd,
		/* numArgs */ {2},	"integer integer"},
    { "!=",	TclSingleOpCmd,		TclCompileNeqOpCmd,
		/* numArgs */ {2},	"value value"},
    { "ne",	TclSingleOpCmd,		TclCompileStrneqOpCmd,
		/* numArgs */ {2},	"value value"},
    { "in",	TclSingleOpCmd,		TclCompileInOpCmd,
		/* numArgs */ {2},	"value list"},
    { "ni",	TclSingleOpCmd,		TclCompileNiOpCmd,
		/* numArgs */ {2},	"value list"},
    { "-",	TclNoIdentOpCmd,	TclCompileMinusOpCmd,
		/* unused */ {0},	"value ?value ...?"},
    { "/",	TclNoIdentOpCmd,	TclCompileDivOpCmd,
		/* unused */ {0},	"value ?value ...?"},
    { "<",	TclSortingOpCmd,	TclCompileLessOpCmd,
		/* unused */ {0},	NULL},
    { "<=",	TclSortingOpCmd,	TclCompileLeqOpCmd,
		/* unused */ {0},	NULL},
    { ">",	TclSortingOpCmd,	TclCompileGreaterOpCmd,
		/* unused */ {0},	NULL},
    { ">=",	TclSortingOpCmd,	TclCompileGeqOpCmd,
		/* unused */ {0},	NULL},
    { "==",	TclSortingOpCmd,	TclCompileEqOpCmd,
		/* unused */ {0},	NULL},
    { "eq",	TclSortingOpCmd,	TclCompileStreqOpCmd,
		/* unused */ {0},	NULL},
    { NULL,	NULL,			NULL,
		{0},			NULL}
};

/*
 * Macros for stack checks. The goal of these macros is to allow the size of
 * the stack to be checked (so preventing overflow) in a *cheap* way. Note
 * that the check needs to be (amortized) cheap since it is on the critical
 * path for recursion.
 */

#if defined(TCL_NO_STACK_CHECK)
/*
 * Stack check disabled: make them noops.
 */

#   define CheckCStack(interp, localIntPtr)	1
#   define GetCStackParams(iPtr)		/* do nothing */
#elif defined(TCL_CROSS_COMPILE)

/*
 * This variable is static and only set *once*, during library initialization.
 * It therefore needs no thread guards.
 */

static int stackGrowsDown = 1;
#   define GetCStackParams(iPtr) \
    stackGrowsDown = TclpGetCStackParams(&((iPtr)->stackBound))
#   define CheckCStack(iPtr, localIntPtr) \
    (stackGrowsDown \
	    ? ((localIntPtr) > (iPtr)->stackBound) \
	    : ((localIntPtr) < (iPtr)->stackBound) \
    )
#else /* !TCL_NO_STACK_CHECK && !TCL_CROSS_COMPILE */
#   define GetCStackParams(iPtr) \
    TclpGetCStackParams(&((iPtr)->stackBound))
#   ifdef TCL_STACK_GROWS_UP
#	define CheckCStack(iPtr, localIntPtr) \
	   (!(iPtr)->stackBound || (localIntPtr) < (iPtr)->stackBound)
#    else /* TCL_STACK_GROWS_UP */
#	define CheckCStack(iPtr, localIntPtr) \
	   ((localIntPtr) > (iPtr)->stackBound)
#    endif /* TCL_STACK_GROWS_UP */
#endif /* TCL_NO_STACK_CHECK/TCL_CROSS_COMPILE */

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateInterp --
 *
 *	Create a new TCL command interpreter.
 *
 * Results:
 *	The return value is a token for the interpreter, which may be used in
 *	calls to functions like Tcl_CreateCmd, Tcl_Eval, or Tcl_DeleteInterp.
 *
 * Side effects:
 *	The command interpreter is initialized with the built-in commands and
 *	with the variables documented in tclvars(n).
 *
 *----------------------------------------------------------------------
 */

Tcl_Interp *
Tcl_CreateInterp(void)
{
    Interp *iPtr;
    Tcl_Interp *interp;
    Command *cmdPtr;
    const BuiltinFuncDef *builtinFuncPtr;
    const OpCmdInfo *opcmdInfoPtr;
    const CmdInfo *cmdInfoPtr;
    Tcl_Namespace *mathfuncNSPtr, *mathopNSPtr;
    union {
	char c[sizeof(short)];
	short s;
    } order;
#ifdef TCL_COMPILE_STATS
    ByteCodeStats *statsPtr;
#endif /* TCL_COMPILE_STATS */
    char mathFuncName[32];
    CallFrame *framePtr;
    int result;

    TclInitSubsystems();

    /*
     * Panic if someone updated the CallFrame structure without also updating
     * the Tcl_CallFrame structure (or vice versa).
     */

    if (sizeof(Tcl_CallFrame) != sizeof(CallFrame)) {
	/*NOTREACHED*/
	Tcl_Panic("Tcl_CallFrame and CallFrame are not the same size");
    }

    /*
     * Initialize support for namespaces and create the global namespace
     * (whose name is ""; an alias is "::"). This also initializes the Tcl
     * object type table and other object management code.
     */

    iPtr = (Interp *) ckalloc(sizeof(Interp));
    interp = (Tcl_Interp *) iPtr;

    iPtr->result = iPtr->resultSpace;
    iPtr->freeProc = NULL;
    iPtr->errorLine = 0;
    iPtr->objResultPtr = Tcl_NewObj();
    Tcl_IncrRefCount(iPtr->objResultPtr);
    iPtr->handle = TclHandleCreate(iPtr);
    iPtr->globalNsPtr = NULL;
    iPtr->hiddenCmdTablePtr = NULL;
    iPtr->interpInfo = NULL;

    iPtr->numLevels = 0;
    iPtr->maxNestingDepth = MAX_NESTING_DEPTH;
    iPtr->framePtr = NULL;	/* Initialise as soon as :: is available */
    iPtr->varFramePtr = NULL;	/* Initialise as soon as :: is available */

    /*
     * TIP #280 - Initialize the arrays used to extend the ByteCode and
     * Proc structures.
     */

    iPtr->cmdFramePtr = NULL;
    iPtr->linePBodyPtr = (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable));
    iPtr->lineBCPtr = (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable));
    iPtr->lineLAPtr = (Tcl_HashTable*) ckalloc (sizeof (Tcl_HashTable));
    iPtr->lineLABCPtr = (Tcl_HashTable*) ckalloc (sizeof (Tcl_HashTable));
    Tcl_InitHashTable(iPtr->linePBodyPtr, TCL_ONE_WORD_KEYS);
    Tcl_InitHashTable(iPtr->lineBCPtr, TCL_ONE_WORD_KEYS);
    Tcl_InitHashTable(iPtr->lineLAPtr, TCL_ONE_WORD_KEYS);
    Tcl_InitHashTable(iPtr->lineLABCPtr, TCL_ONE_WORD_KEYS);
    iPtr->scriptCLLocPtr = NULL;

    iPtr->activeVarTracePtr = NULL;

    iPtr->returnOpts = NULL;
    iPtr->errorInfo = NULL;
    TclNewLiteralStringObj(iPtr->eiVar, "::errorInfo");
    Tcl_IncrRefCount(iPtr->eiVar);
    iPtr->errorCode = NULL;
    TclNewLiteralStringObj(iPtr->ecVar, "::errorCode");
    Tcl_IncrRefCount(iPtr->ecVar);
    iPtr->returnLevel = 1;
    iPtr->returnCode = TCL_OK;

    iPtr->rootFramePtr = NULL;	/* Initialise as soon as :: is available */
    iPtr->lookupNsPtr = NULL;

    iPtr->appendResult = NULL;
    iPtr->appendAvl = 0;
    iPtr->appendUsed = 0;

    Tcl_InitHashTable(&iPtr->packageTable, TCL_STRING_KEYS);
    iPtr->packageUnknown = NULL;

    /* TIP #268 */
    if (getenv("TCL_PKG_PREFER_LATEST") == NULL) {
	iPtr->packagePrefer = PKG_PREFER_STABLE;
    } else {
	iPtr->packagePrefer = PKG_PREFER_LATEST;
    }

    iPtr->cmdCount = 0;
    TclInitLiteralTable(&(iPtr->literalTable));
    iPtr->compileEpoch = 0;
    iPtr->compiledProcPtr = NULL;
    iPtr->resolverPtr = NULL;
    iPtr->evalFlags = 0;
    iPtr->scriptFile = NULL;
    iPtr->flags = 0;
    iPtr->tracePtr = NULL;
    iPtr->tracesForbiddingInline = 0;
    iPtr->activeCmdTracePtr = NULL;
    iPtr->activeInterpTracePtr = NULL;
    iPtr->assocData = NULL;
    iPtr->execEnvPtr = NULL;	/* Set after namespaces initialized. */
    iPtr->emptyObjPtr = Tcl_NewObj();
				/* Another empty object. */
    Tcl_IncrRefCount(iPtr->emptyObjPtr);
    iPtr->resultSpace[0] = 0;
    iPtr->threadId = Tcl_GetCurrentThread();

    /*
     * Initialise the tables for variable traces and searches *before*
     * creating the global ns - so that the trace on errorInfo can be
     * recorded.
     */

    Tcl_InitHashTable(&iPtr->varTraces, TCL_ONE_WORD_KEYS);
    Tcl_InitHashTable(&iPtr->varSearches, TCL_ONE_WORD_KEYS);

    iPtr->globalNsPtr = NULL;	/* Force creation of global ns below. */
    iPtr->globalNsPtr = (Namespace *) Tcl_CreateNamespace(interp, "",
	    NULL, NULL);
    if (iPtr->globalNsPtr == NULL) {
	Tcl_Panic("Tcl_CreateInterp: can't create global namespace");
    }

    /*
     * Initialise the rootCallframe. It cannot be allocated on the stack, as
     * it has to be in place before TclCreateExecEnv tries to use a variable.
     */

    /* This is needed to satisfy GCC 3.3's strict aliasing rules */
    framePtr = (CallFrame *) ckalloc(sizeof(CallFrame));
    result = Tcl_PushCallFrame(interp, (Tcl_CallFrame *) framePtr,
	    (Tcl_Namespace *) iPtr->globalNsPtr, /*isProcCallFrame*/ 0);
    if (result != TCL_OK) {
	Tcl_Panic("Tcl_CreateInterp: failed to push the root stack frame");
    }
    framePtr->objc = 0;

    iPtr->framePtr = framePtr;
    iPtr->varFramePtr = framePtr;
    iPtr->rootFramePtr = framePtr;

    /*
     * Initialize support for code compilation and execution. We call
     * TclCreateExecEnv after initializing namespaces since it tries to
     * reference a Tcl variable (it links to the Tcl "tcl_traceExec"
     * variable).
     */

    iPtr->execEnvPtr = TclCreateExecEnv(interp);

    /*
     * TIP #219, Tcl Channel Reflection API support.
     */

    iPtr->chanMsg = NULL;

    /*
     * Initialize the compilation and execution statistics kept for this
     * interpreter.
     */

#ifdef TCL_COMPILE_STATS
    statsPtr = &(iPtr->stats);
    statsPtr->numExecutions = 0;
    statsPtr->numCompilations = 0;
    statsPtr->numByteCodesFreed = 0;
    (void) memset(statsPtr->instructionCount, 0,
	    sizeof(statsPtr->instructionCount));

    statsPtr->totalSrcBytes = 0.0;
    statsPtr->totalByteCodeBytes = 0.0;
    statsPtr->currentSrcBytes = 0.0;
    statsPtr->currentByteCodeBytes = 0.0;
    (void) memset(statsPtr->srcCount, 0, sizeof(statsPtr->srcCount));
    (void) memset(statsPtr->byteCodeCount, 0, sizeof(statsPtr->byteCodeCount));
    (void) memset(statsPtr->lifetimeCount, 0, sizeof(statsPtr->lifetimeCount));

    statsPtr->currentInstBytes = 0.0;
    statsPtr->currentLitBytes = 0.0;
    statsPtr->currentExceptBytes = 0.0;
    statsPtr->currentAuxBytes = 0.0;
    statsPtr->currentCmdMapBytes = 0.0;

    statsPtr->numLiteralsCreated = 0;
    statsPtr->totalLitStringBytes = 0.0;
    statsPtr->currentLitStringBytes = 0.0;
    (void) memset(statsPtr->literalCount, 0, sizeof(statsPtr->literalCount));
#endif /* TCL_COMPILE_STATS */

    /*
     * Initialise the stub table pointer.
     */

    iPtr->stubTable = &tclStubs;

    /*
     * Initialize the ensemble error message rewriting support.
     */

    iPtr->ensembleRewrite.sourceObjs = NULL;
    iPtr->ensembleRewrite.numRemovedObjs = 0;
    iPtr->ensembleRewrite.numInsertedObjs = 0;

    /*
     * TIP#143: Initialise the resource limit support.
     */

    TclInitLimitSupport(interp);

    /*
     * Initialise the thread-specific data ekeko.
     */

#if defined(TCL_THREADS) && defined(USE_THREAD_ALLOC)
    iPtr->allocCache = TclpGetAllocCache();
#else
    iPtr->allocCache = NULL;
#endif
    iPtr->pendingObjDataPtr = NULL;
    iPtr->asyncReadyPtr = TclGetAsyncReadyPtr();

    /*
     * Insure that the stack checking mechanism for this interp is
     * initialized.
     */

    GetCStackParams(iPtr);

    /*
     * Create the core commands. Do it here, rather than calling
     * Tcl_CreateCommand, because it's faster (there's no need to check for a
     * pre-existing command by the same name). If a command has a Tcl_CmdProc
     * but no Tcl_ObjCmdProc, set the Tcl_ObjCmdProc to
     * TclInvokeStringCommand. This is an object-based wrapper function that
     * extracts strings, calls the string function, and creates an object for
     * the result. Similarly, if a command has a Tcl_ObjCmdProc but no
     * Tcl_CmdProc, set the Tcl_CmdProc to TclInvokeObjectCommand.
     */

    for (cmdInfoPtr = builtInCmds;  cmdInfoPtr->name != NULL; cmdInfoPtr++) {
	int isNew;
	Tcl_HashEntry *hPtr;

	if ((cmdInfoPtr->objProc == NULL)
		&& (cmdInfoPtr->compileProc == NULL)) {
	    Tcl_Panic("builtin command with NULL object command proc and a NULL compile proc");
	}

	hPtr = Tcl_CreateHashEntry(&iPtr->globalNsPtr->cmdTable,
		cmdInfoPtr->name, &isNew);
	if (isNew) {
	    cmdPtr = (Command *) ckalloc(sizeof(Command));
	    cmdPtr->hPtr = hPtr;
	    cmdPtr->nsPtr = iPtr->globalNsPtr;
	    cmdPtr->refCount = 1;
	    cmdPtr->cmdEpoch = 0;
	    cmdPtr->compileProc = cmdInfoPtr->compileProc;
	    cmdPtr->proc = TclInvokeObjectCommand;
	    cmdPtr->clientData = cmdPtr;
	    cmdPtr->objProc = cmdInfoPtr->objProc;
	    cmdPtr->objClientData = NULL;
	    cmdPtr->deleteProc = NULL;
	    cmdPtr->deleteData = NULL;
	    cmdPtr->flags = 0;
	    cmdPtr->importRefPtr = NULL;
	    cmdPtr->tracePtr = NULL;
	    Tcl_SetHashValue(hPtr, cmdPtr);
	}
    }

    /*
     * Create the "chan", "dict", "info" and "string" ensembles. Note that all
     * these commands (and their subcommands that are not present in the
     * global namespace) are wholly safe.
     */

    TclInitChanCmd(interp);
    TclInitDictCmd(interp);
    TclInitInfoCmd(interp);
    TclInitStringCmd(interp);

    /*
     * Register "clock" subcommands. These *do* go through
     * Tcl_CreateObjCommand, since they aren't in the global namespace and
     * involve ensembles.
     */

    TclClockInit(interp);

    /*
     * Register the built-in functions. This is empty now that they are
     * implemented as commands in the ::tcl::mathfunc namespace.
     */

    /*
     * Register the default [interp bgerror] handler.
     */

    Tcl_CreateObjCommand(interp, "::tcl::Bgerror",
	    TclDefaultBgErrorHandlerObjCmd, NULL, NULL);

    /*
     * Create an unsupported command for debugging bytecode.
     */

    Tcl_CreateObjCommand(interp, "::tcl::unsupported::disassemble",
	    Tcl_DisassembleObjCmd, NULL, NULL);

#ifdef USE_DTRACE
    /*
     * Register the tcl::dtrace command.
     */

    Tcl_CreateObjCommand(interp, "::tcl::dtrace", DTraceObjCmd, NULL, NULL);
#endif /* USE_DTRACE */

    /*
     * Register the builtin math functions.
     */

    mathfuncNSPtr = Tcl_CreateNamespace(interp, "::tcl::mathfunc", NULL,NULL);
    if (mathfuncNSPtr == NULL) {
	Tcl_Panic("Can't create math function namespace");
    }
    strcpy(mathFuncName, "::tcl::mathfunc::");
#define MATH_FUNC_PREFIX_LEN 17 /* == strlen("::tcl::mathfunc::") */
    for (builtinFuncPtr = BuiltinFuncTable; builtinFuncPtr->name != NULL;
	    builtinFuncPtr++) {
	strcpy(mathFuncName+MATH_FUNC_PREFIX_LEN, builtinFuncPtr->name);
	Tcl_CreateObjCommand(interp, mathFuncName,
		builtinFuncPtr->objCmdProc, builtinFuncPtr->clientData, NULL);
	Tcl_Export(interp, mathfuncNSPtr, builtinFuncPtr->name, 0);
    }

    /*
     * Register the mathematical "operator" commands. [TIP #174]
     */

    mathopNSPtr = Tcl_CreateNamespace(interp, "::tcl::mathop", NULL, NULL);
#define MATH_OP_PREFIX_LEN 15 /* == strlen("::tcl::mathop::") */
    if (mathopNSPtr == NULL) {
	Tcl_Panic("can't create math operator namespace");
    }
    (void) Tcl_Export(interp, mathopNSPtr, "*", 1);
    strcpy(mathFuncName, "::tcl::mathop::");
    for (opcmdInfoPtr=mathOpCmds ; opcmdInfoPtr->name!=NULL ; opcmdInfoPtr++){
	TclOpCmdClientData *occdPtr = (TclOpCmdClientData *)
		ckalloc(sizeof(TclOpCmdClientData));

	occdPtr->op = opcmdInfoPtr->name;
	occdPtr->i.numArgs = opcmdInfoPtr->i.numArgs;
	occdPtr->expected = opcmdInfoPtr->expected;
	strcpy(mathFuncName + MATH_OP_PREFIX_LEN, opcmdInfoPtr->name);
	cmdPtr = (Command *) Tcl_CreateObjCommand(interp, mathFuncName,
		opcmdInfoPtr->objProc, occdPtr, DeleteOpCmdClientData);
	if (cmdPtr == NULL) {
	    Tcl_Panic("failed to create math operator %s",
		    opcmdInfoPtr->name);
	} else if (opcmdInfoPtr->compileProc != NULL) {
	    cmdPtr->compileProc = opcmdInfoPtr->compileProc;
	}
    }

    /*
     * Do Multiple/Safe Interps Tcl init stuff
     */

    TclInterpInit(interp);
    TclSetupEnv(interp);

    /*
     * TIP #59: Make embedded configuration information available.
     */

    TclInitEmbeddedConfigurationInformation(interp);

    /*
     * Compute the byte order of this machine.
     */

    order.s = 1;
    Tcl_SetVar2(interp, "tcl_platform", "byteOrder",
	    ((order.c[0] == 1) ? "littleEndian" : "bigEndian"),
	    TCL_GLOBAL_ONLY);

    Tcl_SetVar2Ex(interp, "tcl_platform", "wordSize",
	    Tcl_NewLongObj((long) sizeof(long)), TCL_GLOBAL_ONLY);

    /* TIP #291 */
    Tcl_SetVar2Ex(interp, "tcl_platform", "pointerSize",
	    Tcl_NewLongObj((long) sizeof(void *)), TCL_GLOBAL_ONLY);

    /*
     * Set up other variables such as tcl_version and tcl_library
     */

    Tcl_SetVar(interp, "tcl_patchLevel", TCL_PATCH_LEVEL, TCL_GLOBAL_ONLY);
    Tcl_SetVar(interp, "tcl_version", TCL_VERSION, TCL_GLOBAL_ONLY);
    Tcl_TraceVar2(interp, "tcl_precision", NULL,
	    TCL_GLOBAL_ONLY|TCL_TRACE_READS|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
	    TclPrecTraceProc, NULL);
    TclpSetVariables(interp);

#ifdef TCL_THREADS
    /*
     * The existence of the "threaded" element of the tcl_platform array
     * indicates that this particular Tcl shell has been compiled with threads
     * turned on. Using "info exists tcl_platform(threaded)" a Tcl script can
     * introspect on the interpreter level of thread safety.
     */

    Tcl_SetVar2(interp, "tcl_platform", "threaded", "1", TCL_GLOBAL_ONLY);
#endif

    /*
     * Register Tcl's version number.
     * TIP #268: Full patchlevel instead of just major.minor
     */

    Tcl_PkgProvideEx(interp, "Tcl", TCL_PATCH_LEVEL, &tclStubs);

#ifdef Tcl_InitStubs
#undef Tcl_InitStubs
#endif
    Tcl_InitStubs(interp, TCL_VERSION, 1);

    if (TclTommath_Init(interp) != TCL_OK) {
	Tcl_Panic(Tcl_GetString(Tcl_GetObjResult(interp)));
    }

    return interp;
}

static void
DeleteOpCmdClientData(
    ClientData clientData)
{
    TclOpCmdClientData *occdPtr = clientData;

    ckfree((char *) occdPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TclHideUnsafeCommands --
 *
 *	Hides base commands that are not marked as safe from this interpreter.
 *
 * Results:
 *	TCL_OK if it succeeds, TCL_ERROR else.
 *
 * Side effects:
 *	Hides functionality in an interpreter.
 *
 *----------------------------------------------------------------------
 */

int
TclHideUnsafeCommands(
    Tcl_Interp *interp)		/* Hide commands in this interpreter. */
{
    register const CmdInfo *cmdInfoPtr;

    if (interp == NULL) {
	return TCL_ERROR;
    }
    for (cmdInfoPtr = builtInCmds; cmdInfoPtr->name != NULL; cmdInfoPtr++) {
	if (!cmdInfoPtr->isSafe) {
	    Tcl_HideCommand(interp, cmdInfoPtr->name, cmdInfoPtr->name);
	}
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * Tcl_CallWhenDeleted --
 *
 *	Arrange for a function to be called before a given interpreter is
 *	deleted. The function is called as soon as Tcl_DeleteInterp is called;
 *	if Tcl_CallWhenDeleted is called on an interpreter that has already
 *	been deleted, the function will be called when the last Tcl_Release is
 *	done on the interpreter.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	When Tcl_DeleteInterp is invoked to delete interp, proc will be
 *	invoked. See the manual entry for details.
 *
 *--------------------------------------------------------------
 */

void
Tcl_CallWhenDeleted(
    Tcl_Interp *interp,		/* Interpreter to watch. */
    Tcl_InterpDeleteProc *proc,	/* Function to call when interpreter is about
				 * to be deleted. */
    ClientData clientData)	/* One-word value to pass to proc. */
{
    Interp *iPtr = (Interp *) interp;
    static Tcl_ThreadDataKey assocDataCounterKey;
    int *assocDataCounterPtr =
	    Tcl_GetThreadData(&assocDataCounterKey, (int)sizeof(int));
    int isNew;
    char buffer[32 + TCL_INTEGER_SPACE];
    AssocData *dPtr = (AssocData *) ckalloc(sizeof(AssocData));
    Tcl_HashEntry *hPtr;

    sprintf(buffer, "Assoc Data Key #%d", *assocDataCounterPtr);
    (*assocDataCounterPtr)++;

    if (iPtr->assocData == NULL) {
	iPtr->assocData = (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable));
	Tcl_InitHashTable(iPtr->assocData, TCL_STRING_KEYS);
    }
    hPtr = Tcl_CreateHashEntry(iPtr->assocData, buffer, &isNew);
    dPtr->proc = proc;
    dPtr->clientData = clientData;
    Tcl_SetHashValue(hPtr, dPtr);
}

/*
 *--------------------------------------------------------------
 *
 * Tcl_DontCallWhenDeleted --
 *
 *	Cancel the arrangement for a function to be called when a given
 *	interpreter is deleted.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	If proc and clientData were previously registered as a callback via
 *	Tcl_CallWhenDeleted, they are unregistered. If they weren't previously
 *	registered then nothing happens.
 *
 *--------------------------------------------------------------
 */

void
Tcl_DontCallWhenDeleted(
    Tcl_Interp *interp,		/* Interpreter to watch. */
    Tcl_InterpDeleteProc *proc,	/* Function to call when interpreter is about
				 * to be deleted. */
    ClientData clientData)	/* One-word value to pass to proc. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashTable *hTablePtr;
    Tcl_HashSearch hSearch;
    Tcl_HashEntry *hPtr;
    AssocData *dPtr;

    hTablePtr = iPtr->assocData;
    if (hTablePtr == NULL) {
	return;
    }
    for (hPtr = Tcl_FirstHashEntry(hTablePtr, &hSearch); hPtr != NULL;
	    hPtr = Tcl_NextHashEntry(&hSearch)) {
	dPtr = (AssocData *) Tcl_GetHashValue(hPtr);
	if ((dPtr->proc == proc) && (dPtr->clientData == clientData)) {
	    ckfree((char *) dPtr);
	    Tcl_DeleteHashEntry(hPtr);
	    return;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetAssocData --
 *
 *	Creates a named association between user-specified data, a delete
 *	function and this interpreter. If the association already exists the
 *	data is overwritten with the new data. The delete function will be
 *	invoked when the interpreter is deleted.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Sets the associated data, creates the association if needed.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetAssocData(
    Tcl_Interp *interp,		/* Interpreter to associate with. */
    const char *name,		/* Name for association. */
    Tcl_InterpDeleteProc *proc,	/* Proc to call when interpreter is about to
				 * be deleted. */
    ClientData clientData)	/* One-word value to pass to proc. */
{
    Interp *iPtr = (Interp *) interp;
    AssocData *dPtr;
    Tcl_HashEntry *hPtr;
    int isNew;

    if (iPtr->assocData == NULL) {
	iPtr->assocData = (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable));
	Tcl_InitHashTable(iPtr->assocData, TCL_STRING_KEYS);
    }
    hPtr = Tcl_CreateHashEntry(iPtr->assocData, name, &isNew);
    if (isNew == 0) {
	dPtr = Tcl_GetHashValue(hPtr);
    } else {
	dPtr = (AssocData *) ckalloc(sizeof(AssocData));
    }
    dPtr->proc = proc;
    dPtr->clientData = clientData;

    Tcl_SetHashValue(hPtr, dPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteAssocData --
 *
 *	Deletes a named association of user-specified data with the specified
 *	interpreter.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Deletes the association.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_DeleteAssocData(
    Tcl_Interp *interp,		/* Interpreter to associate with. */
    const char *name)		/* Name of association. */
{
    Interp *iPtr = (Interp *) interp;
    AssocData *dPtr;
    Tcl_HashEntry *hPtr;

    if (iPtr->assocData == NULL) {
	return;
    }
    hPtr = Tcl_FindHashEntry(iPtr->assocData, name);
    if (hPtr == NULL) {
	return;
    }
    dPtr = Tcl_GetHashValue(hPtr);
    if (dPtr->proc != NULL) {
	dPtr->proc(dPtr->clientData, interp);
    }
    ckfree((char *) dPtr);
    Tcl_DeleteHashEntry(hPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetAssocData --
 *
 *	Returns the client data associated with this name in the specified
 *	interpreter.
 *
 * Results:
 *	The client data in the AssocData record denoted by the named
 *	association, or NULL.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

ClientData
Tcl_GetAssocData(
    Tcl_Interp *interp,		/* Interpreter associated with. */
    const char *name,		/* Name of association. */
    Tcl_InterpDeleteProc **procPtr)
				/* Pointer to place to store address of
				 * current deletion callback. */
{
    Interp *iPtr = (Interp *) interp;
    AssocData *dPtr;
    Tcl_HashEntry *hPtr;

    if (iPtr->assocData == NULL) {
	return NULL;
    }
    hPtr = Tcl_FindHashEntry(iPtr->assocData, name);
    if (hPtr == NULL) {
	return NULL;
    }
    dPtr = Tcl_GetHashValue(hPtr);
    if (procPtr != NULL) {
	*procPtr = dPtr->proc;
    }
    return dPtr->clientData;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_InterpDeleted --
 *
 *	Returns nonzero if the interpreter has been deleted with a call to
 *	Tcl_DeleteInterp.
 *
 * Results:
 *	Nonzero if the interpreter is deleted, zero otherwise.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_InterpDeleted(
    Tcl_Interp *interp)
{
    return (((Interp *) interp)->flags & DELETED) ? 1 : 0;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteInterp --
 *
 *	Ensures that the interpreter will be deleted eventually. If there are
 *	no Tcl_Preserve calls in effect for this interpreter, it is deleted
 *	immediately, otherwise the interpreter is deleted when the last
 *	Tcl_Preserve is matched by a call to Tcl_Release. In either case, the
 *	function runs the currently registered deletion callbacks.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The interpreter is marked as deleted. The caller may still use it
 *	safely if there are calls to Tcl_Preserve in effect for the
 *	interpreter, but further calls to Tcl_Eval etc in this interpreter
 *	will fail.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_DeleteInterp(
    Tcl_Interp *interp)		/* Token for command interpreter (returned by
				 * a previous call to Tcl_CreateInterp). */
{
    Interp *iPtr = (Interp *) interp;

    /*
     * If the interpreter has already been marked deleted, just punt.
     */

    if (iPtr->flags & DELETED) {
	return;
    }

    /*
     * Mark the interpreter as deleted. No further evals will be allowed.
     * Increase the compileEpoch as a signal to compiled bytecodes.
     */

    iPtr->flags |= DELETED;
    iPtr->compileEpoch++;

    /*
     * Ensure that the interpreter is eventually deleted.
     */

    Tcl_EventuallyFree(interp, (Tcl_FreeProc *) DeleteInterpProc);
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteInterpProc --
 *
 *	Helper function to delete an interpreter. This function is called when
 *	the last call to Tcl_Preserve on this interpreter is matched by a call
 *	to Tcl_Release. The function cleans up all resources used in the
 *	interpreter and calls all currently registered interpreter deletion
 *	callbacks.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Whatever the interpreter deletion callbacks do. Frees resources used
 *	by the interpreter.
 *
 *----------------------------------------------------------------------
 */

static void
DeleteInterpProc(
    Tcl_Interp *interp)		/* Interpreter to delete. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    Tcl_HashTable *hTablePtr;
    ResolverScheme *resPtr, *nextResPtr;

    /*
     * Punt if there is an error in the Tcl_Release/Tcl_Preserve matchup.
     */

    if (iPtr->numLevels > 0) {
	Tcl_Panic("DeleteInterpProc called with active evals");
    }

    /*
     * The interpreter should already be marked deleted; otherwise how did we
     * get here?
     */

    if (!(iPtr->flags & DELETED)) {
	Tcl_Panic("DeleteInterpProc called on interpreter not marked deleted");
    }

    /*
     * TIP #219, Tcl Channel Reflection API. Discard a leftover state.
     */

    if (iPtr->chanMsg != NULL) {
	Tcl_DecrRefCount(iPtr->chanMsg);
	iPtr->chanMsg = NULL;
    }

    /*
     * Shut down all limit handler callback scripts that call back into this
     * interpreter. Then eliminate all limit handlers for this interpreter.
     */

    TclRemoveScriptLimitCallbacks(interp);
    TclLimitRemoveAllHandlers(interp);

    /*
     * Dismantle the namespace here, before we clear the assocData. If any
     * background errors occur here, they will be deleted below.
     *
     * Dismantle the namespace after freeing the iPtr->handle so that each
     * bytecode releases its literals without caring to update the literal
     * table, as it will be freed later in this function without further use.
     */

    TclCleanupLiteralTable(interp, &(iPtr->literalTable));
    TclHandleFree(iPtr->handle);
    TclTeardownNamespace(iPtr->globalNsPtr);

    /*
     * Delete all the hidden commands.
     */

    hTablePtr = iPtr->hiddenCmdTablePtr;
    if (hTablePtr != NULL) {
	/*
	 * Non-pernicious deletion. The deletion callbacks will not be allowed
	 * to create any new hidden or non-hidden commands.
	 * Tcl_DeleteCommandFromToken() will remove the entry from the
	 * hiddenCmdTablePtr.
	 */

	hPtr = Tcl_FirstHashEntry(hTablePtr, &search);
	for (; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
	    Tcl_DeleteCommandFromToken(interp,
		    (Tcl_Command) Tcl_GetHashValue(hPtr));
	}
	Tcl_DeleteHashTable(hTablePtr);
	ckfree((char *) hTablePtr);
    }

    /*
     * Invoke deletion callbacks; note that a callback can create new
     * callbacks, so we iterate.
     */

    while (iPtr->assocData != NULL) {
	AssocData *dPtr;

	hTablePtr = iPtr->assocData;
	iPtr->assocData = NULL;
	for (hPtr = Tcl_FirstHashEntry(hTablePtr, &search);
		hPtr != NULL;
		hPtr = Tcl_FirstHashEntry(hTablePtr, &search)) {
	    dPtr = Tcl_GetHashValue(hPtr);
	    Tcl_DeleteHashEntry(hPtr);
	    if (dPtr->proc != NULL) {
		dPtr->proc(dPtr->clientData, interp);
	    }
	    ckfree((char *) dPtr);
	}
	Tcl_DeleteHashTable(hTablePtr);
	ckfree((char *) hTablePtr);
    }

    /*
     * Pop the root frame pointer and finish deleting the global
     * namespace. The order is important [Bug 1658572].
     */

    if (iPtr->framePtr != iPtr->rootFramePtr) {
	Tcl_Panic("DeleteInterpProc: popping rootCallFrame with other frames on top");
    }
    Tcl_PopCallFrame(interp);
    ckfree((char *) iPtr->rootFramePtr);
    iPtr->rootFramePtr = NULL;
    Tcl_DeleteNamespace((Tcl_Namespace *) iPtr->globalNsPtr);

    /*
     * Free up the result *after* deleting variables, since variable deletion
     * could have transferred ownership of the result string to Tcl.
     */

    Tcl_FreeResult(interp);
    interp->result = NULL;
    Tcl_DecrRefCount(iPtr->objResultPtr);
    iPtr->objResultPtr = NULL;
    Tcl_DecrRefCount(iPtr->ecVar);
    if (iPtr->errorCode) {
	Tcl_DecrRefCount(iPtr->errorCode);
	iPtr->errorCode = NULL;
    }
    Tcl_DecrRefCount(iPtr->eiVar);
    if (iPtr->errorInfo) {
	Tcl_DecrRefCount(iPtr->errorInfo);
	iPtr->errorInfo = NULL;
    }
    if (iPtr->returnOpts) {
	Tcl_DecrRefCount(iPtr->returnOpts);
    }
    if (iPtr->appendResult != NULL) {
	ckfree(iPtr->appendResult);
	iPtr->appendResult = NULL;
    }
    TclFreePackageInfo(iPtr);
    while (iPtr->tracePtr != NULL) {
	Tcl_DeleteTrace((Tcl_Interp *) iPtr, (Tcl_Trace) iPtr->tracePtr);
    }
    if (iPtr->execEnvPtr != NULL) {
	TclDeleteExecEnv(iPtr->execEnvPtr);
    }
    Tcl_DecrRefCount(iPtr->emptyObjPtr);
    iPtr->emptyObjPtr = NULL;

    resPtr = iPtr->resolverPtr;
    while (resPtr) {
	nextResPtr = resPtr->nextPtr;
	ckfree(resPtr->name);
	ckfree((char *) resPtr);
	resPtr = nextResPtr;
    }

    /*
     * Free up literal objects created for scripts compiled by the
     * interpreter.
     */

    TclDeleteLiteralTable(interp, &(iPtr->literalTable));

    /*
     * TIP #280 - Release the arrays for ByteCode/Proc extension, and
     * contents.
     */

    {
	Tcl_HashEntry *hPtr;
	Tcl_HashSearch hSearch;
	int i;

	for (hPtr = Tcl_FirstHashEntry(iPtr->linePBodyPtr, &hSearch);
		hPtr != NULL;
		hPtr = Tcl_NextHashEntry(&hSearch)) {
	    CmdFrame *cfPtr = Tcl_GetHashValue(hPtr);

	    if (cfPtr->type == TCL_LOCATION_SOURCE) {
		Tcl_DecrRefCount(cfPtr->data.eval.path);
	    }
	    ckfree((char *) cfPtr->line);
	    ckfree((char *) cfPtr);
	    Tcl_DeleteHashEntry(hPtr);
	}
	Tcl_DeleteHashTable(iPtr->linePBodyPtr);
	ckfree((char *) iPtr->linePBodyPtr);
	iPtr->linePBodyPtr = NULL;

	/*
	 * See also tclCompile.c, TclCleanupByteCode
	 */

	for (hPtr = Tcl_FirstHashEntry(iPtr->lineBCPtr, &hSearch);
		hPtr != NULL;
		hPtr = Tcl_NextHashEntry(&hSearch)) {
	    ExtCmdLoc *eclPtr = (ExtCmdLoc *) Tcl_GetHashValue(hPtr);

	    if (eclPtr->type == TCL_LOCATION_SOURCE) {
		Tcl_DecrRefCount(eclPtr->path);
	    }
	    for (i=0; i< eclPtr->nuloc; i++) {
		ckfree((char *) eclPtr->loc[i].line);
	    }

	    if (eclPtr->loc != NULL) {
		ckfree((char *) eclPtr->loc);
	    }

	    Tcl_DeleteHashTable (&eclPtr->litInfo);

	    ckfree((char *) eclPtr);
	    Tcl_DeleteHashEntry(hPtr);
	}
	Tcl_DeleteHashTable(iPtr->lineBCPtr);
	ckfree((char *) iPtr->lineBCPtr);
	iPtr->lineBCPtr = NULL;

	/*
	 * Location stack for uplevel/eval/... scripts which were passed
	 * through proc arguments. Actually we track all arguments as we
	 * don't, cannot know which arguments will be used as scripts and
	 * which won't.
	 */

	if (iPtr->lineLAPtr->numEntries) {
	    /*
	     * When the interp goes away we have nothing on the stack, so
	     * there are no arguments, so this table has to be empty.
	     */

	    Tcl_Panic ("Argument location tracking table not empty");
	}

	Tcl_DeleteHashTable (iPtr->lineLAPtr);
	ckfree((char*) iPtr->lineLAPtr);
	iPtr->lineLAPtr = NULL;

	if (iPtr->lineLABCPtr->numEntries) {
	    /*
	     * When the interp goes away we have nothing on the stack, so
	     * there are no arguments, so this table has to be empty.
	     */

	    Tcl_Panic ("Argument location tracking table not empty");
	}

	Tcl_DeleteHashTable (iPtr->lineLABCPtr);
	ckfree((char*) iPtr->lineLABCPtr);
	iPtr->lineLABCPtr = NULL;
    }

    Tcl_DeleteHashTable(&iPtr->varTraces);
    Tcl_DeleteHashTable(&iPtr->varSearches);

    ckfree((char *) iPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_HideCommand --
 *
 *	Makes a command hidden so that it cannot be invoked from within an
 *	interpreter, only from within an ancestor.
 *
 * Results:
 *	A standard Tcl result; also leaves a message in the interp's result if
 *	an error occurs.
 *
 * Side effects:
 *	Removes a command from the command table and create an entry into the
 *	hidden command table under the specified token name.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_HideCommand(
    Tcl_Interp *interp,		/* Interpreter in which to hide command. */
    const char *cmdName,	/* Name of command to hide. */
    const char *hiddenCmdToken)	/* Token name of the to-be-hidden command. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_Command cmd;
    Command *cmdPtr;
    Tcl_HashTable *hiddenCmdTablePtr;
    Tcl_HashEntry *hPtr;
    int isNew;

    if (iPtr->flags & DELETED) {
	/*
	 * The interpreter is being deleted. Do not create any new structures,
	 * because it is not safe to modify the interpreter.
	 */

	return TCL_ERROR;
    }

    /*
     * Disallow hiding of commands that are currently in a namespace or
     * renaming (as part of hiding) into a namespace (because the current
     * implementation with a single global table and the needed uniqueness of
     * names cause problems with namespaces).
     *
     * We don't need to check for "::" in cmdName because the real check is on
     * the nsPtr below.
     *
     * hiddenCmdToken is just a string which is not interpreted in any way. It
     * may contain :: but the string is not interpreted as a namespace
     * qualifier command name. Thus, hiding foo::bar to foo::bar and then
     * trying to expose or invoke ::foo::bar will NOT work; but if the
     * application always uses the same strings it will get consistent
     * behaviour.
     *
     * But as we currently limit ourselves to the global namespace only for
     * the source, in order to avoid potential confusion, lets prevent "::" in
     * the token too. - dl
     */

    if (strstr(hiddenCmdToken, "::") != NULL) {
	Tcl_AppendResult(interp,
		"cannot use namespace qualifiers in hidden command"
		" token (rename)", NULL);
	return TCL_ERROR;
    }

    /*
     * Find the command to hide. An error is returned if cmdName can't be
     * found. Look up the command only from the global namespace. Full path of
     * the command must be given if using namespaces.
     */

    cmd = Tcl_FindCommand(interp, cmdName, NULL,
	    /*flags*/ TCL_LEAVE_ERR_MSG | TCL_GLOBAL_ONLY);
    if (cmd == (Tcl_Command) NULL) {
	return TCL_ERROR;
    }
    cmdPtr = (Command *) cmd;

    /*
     * Check that the command is really in global namespace
     */

    if (cmdPtr->nsPtr != iPtr->globalNsPtr) {
	Tcl_AppendResult(interp, "can only hide global namespace commands"
		" (use rename then hide)", NULL);
	return TCL_ERROR;
    }

    /*
     * Initialize the hidden command table if necessary.
     */

    hiddenCmdTablePtr = iPtr->hiddenCmdTablePtr;
    if (hiddenCmdTablePtr == NULL) {
	hiddenCmdTablePtr = (Tcl_HashTable *)
		ckalloc((unsigned) sizeof(Tcl_HashTable));
	Tcl_InitHashTable(hiddenCmdTablePtr, TCL_STRING_KEYS);
	iPtr->hiddenCmdTablePtr = hiddenCmdTablePtr;
    }

    /*
     * It is an error to move an exposed command to a hidden command with
     * hiddenCmdToken if a hidden command with the name hiddenCmdToken already
     * exists.
     */

    hPtr = Tcl_CreateHashEntry(hiddenCmdTablePtr, hiddenCmdToken, &isNew);
    if (!isNew) {
	Tcl_AppendResult(interp, "hidden command named \"", hiddenCmdToken,
		"\" already exists", NULL);
	return TCL_ERROR;
    }

    /*
     * NB: This code is currently 'like' a rename to a specialy set apart name
     * table. Changes here and in TclRenameCommand must be kept in synch until
     * the common parts are actually factorized out.
     */

    /*
     * Remove the hash entry for the command from the interpreter command
     * table. This is like deleting the command, so bump its command epoch;
     * this invalidates any cached references that point to the command.
     */

    if (cmdPtr->hPtr != NULL) {
	Tcl_DeleteHashEntry(cmdPtr->hPtr);
	cmdPtr->hPtr = NULL;
	cmdPtr->cmdEpoch++;
    }

    /*
     * The list of command exported from the namespace might have changed.
     * However, we do not need to recompute this just yet; next time we need
     * the info will be soon enough.
     */

    TclInvalidateNsCmdLookup(cmdPtr->nsPtr);

    /*
     * Now link the hash table entry with the command structure. We ensured
     * above that the nsPtr was right.
     */

    cmdPtr->hPtr = hPtr;
    Tcl_SetHashValue(hPtr, cmdPtr);

    /*
     * If the command being hidden has a compile function, increment the
     * interpreter's compileEpoch to invalidate its compiled code. This makes
     * sure that we don't later try to execute old code compiled with
     * command-specific (i.e., inline) bytecodes for the now-hidden command.
     * This field is checked in Tcl_EvalObj and ObjInterpProc, and code whose
     * compilation epoch doesn't match is recompiled.
     */

    if (cmdPtr->compileProc != NULL) {
	iPtr->compileEpoch++;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ExposeCommand --
 *
 *	Makes a previously hidden command callable from inside the interpreter
 *	instead of only by its ancestors.
 *
 * Results:
 *	A standard Tcl result. If an error occurs, a message is left in the
 *	interp's result.
 *
 * Side effects:
 *	Moves commands from one hash table to another.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_ExposeCommand(
    Tcl_Interp *interp,		/* Interpreter in which to make command
				 * callable. */
    const char *hiddenCmdToken,	/* Name of hidden command. */
    const char *cmdName)	/* Name of to-be-exposed command. */
{
    Interp *iPtr = (Interp *) interp;
    Command *cmdPtr;
    Namespace *nsPtr;
    Tcl_HashEntry *hPtr;
    Tcl_HashTable *hiddenCmdTablePtr;
    int isNew;

    if (iPtr->flags & DELETED) {
	/*
	 * The interpreter is being deleted. Do not create any new structures,
	 * because it is not safe to modify the interpreter.
	 */

	return TCL_ERROR;
    }

    /*
     * Check that we have a regular name for the command (that the user is not
     * trying to do an expose and a rename (to another namespace) at the same
     * time).
     */

    if (strstr(cmdName, "::") != NULL) {
	Tcl_AppendResult(interp, "cannot expose to a namespace "
		"(use expose to toplevel, then rename)", NULL);
	return TCL_ERROR;
    }

    /*
     * Get the command from the hidden command table:
     */

    hPtr = NULL;
    hiddenCmdTablePtr = iPtr->hiddenCmdTablePtr;
    if (hiddenCmdTablePtr != NULL) {
	hPtr = Tcl_FindHashEntry(hiddenCmdTablePtr, hiddenCmdToken);
    }
    if (hPtr == NULL) {
	Tcl_AppendResult(interp, "unknown hidden command \"", hiddenCmdToken,
		"\"", NULL);
	return TCL_ERROR;
    }
    cmdPtr = Tcl_GetHashValue(hPtr);

    /*
     * Check that we have a true global namespace command (enforced by
     * Tcl_HideCommand() but let's double check. (If it was not, we would not
     * really know how to handle it).
     */

    if (cmdPtr->nsPtr != iPtr->globalNsPtr) {
	/*
	 * This case is theoritically impossible, we might rather Tcl_Panic()
	 * than 'nicely' erroring out ?
	 */

	Tcl_AppendResult(interp,
		"trying to expose a non global command name space command",
		NULL);
	return TCL_ERROR;
    }

    /*
     * This is the global table.
     */

    nsPtr = cmdPtr->nsPtr;

    /*
     * It is an error to overwrite an existing exposed command as a result of
     * exposing a previously hidden command.
     */

    hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, cmdName, &isNew);
    if (!isNew) {
	Tcl_AppendResult(interp, "exposed command \"", cmdName,
		"\" already exists", NULL);
	return TCL_ERROR;
    }

    /*
     * The list of command exported from the namespace might have changed.
     * However, we do not need to recompute this just yet; next time we need
     * the info will be soon enough.
     */

    TclInvalidateNsCmdLookup(nsPtr);

    /*
     * Remove the hash entry for the command from the interpreter hidden
     * command table.
     */

    if (cmdPtr->hPtr != NULL) {
	Tcl_DeleteHashEntry(cmdPtr->hPtr);
	cmdPtr->hPtr = NULL;
    }

    /*
     * Now link the hash table entry with the command structure. This is like
     * creating a new command, so deal with any shadowing of commands in the
     * global namespace.
     */

    cmdPtr->hPtr = hPtr;

    Tcl_SetHashValue(hPtr, cmdPtr);

    /*
     * Not needed as we are only in the global namespace (but would be needed
     * again if we supported namespace command hiding)
     *
     * TclResetShadowedCmdRefs(interp, cmdPtr);
     */

    /*
     * If the command being exposed has a compile function, increment
     * interpreter's compileEpoch to invalidate its compiled code. This makes
     * sure that we don't later try to execute old code compiled assuming the
     * command is hidden. This field is checked in Tcl_EvalObj and
     * ObjInterpProc, and code whose compilation epoch doesn't match is
     * recompiled.
     */

    if (cmdPtr->compileProc != NULL) {
	iPtr->compileEpoch++;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateCommand --
 *
 *	Define a new command in a command table.
 *
 * Results:
 *	The return value is a token for the command, which can be used in
 *	future calls to Tcl_GetCommandName.
 *
 * Side effects:
 *	If a command named cmdName already exists for interp, it is deleted.
 *	In the future, when cmdName is seen as the name of a command by
 *	Tcl_Eval, proc will be called. To support the bytecode interpreter,
 *	the command is created with a wrapper Tcl_ObjCmdProc
 *	(TclInvokeStringCommand) that eventially calls proc. When the command
 *	is deleted from the table, deleteProc will be called. See the manual
 *	entry for details on the calling sequence.
 *
 *----------------------------------------------------------------------
 */

Tcl_Command
Tcl_CreateCommand(
    Tcl_Interp *interp,		/* Token for command interpreter returned by a
				 * previous call to Tcl_CreateInterp. */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the
				 * specified namespace; otherwise it is put in
				 * the global namespace. */
    Tcl_CmdProc *proc,		/* Function to associate with cmdName. */
    ClientData clientData,	/* Arbitrary value passed to string proc. */
    Tcl_CmdDeleteProc *deleteProc)
				/* If not NULL, gives a function to call when
				 * this command is deleted. */
{
    Interp *iPtr = (Interp *) interp;
    ImportRef *oldRefPtr = NULL;
    Namespace *nsPtr, *dummy1, *dummy2;
    Command *cmdPtr, *refCmdPtr;
    Tcl_HashEntry *hPtr;
    const char *tail;
    int isNew;
    ImportedCmdData *dataPtr;

    if (iPtr->flags & DELETED) {
	/*
	 * The interpreter is being deleted. Don't create any new commands;
	 * it's not safe to muck with the interpreter anymore.
	 */

	return (Tcl_Command) NULL;
    }

    /*
     * Determine where the command should reside. If its name contains
     * namespace qualifiers, we put it in the specified namespace; otherwise,
     * we always put it in the global namespace.
     */

    if (strstr(cmdName, "::") != NULL) {
	TclGetNamespaceForQualName(interp, cmdName, NULL,
		TCL_CREATE_NS_IF_UNKNOWN, &nsPtr, &dummy1, &dummy2, &tail);
	if ((nsPtr == NULL) || (tail == NULL)) {
	    return (Tcl_Command) NULL;
	}
    } else {
	nsPtr = iPtr->globalNsPtr;
	tail = cmdName;
    }

    hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
    if (!isNew) {
	/*
	 * Command already exists. Delete the old one. Be careful to preserve
	 * any existing import links so we can restore them down below. That
	 * way, you can redefine a command and its import status will remain
	 * intact.
	 */

	cmdPtr = Tcl_GetHashValue(hPtr);
	oldRefPtr = cmdPtr->importRefPtr;
	cmdPtr->importRefPtr = NULL;

	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
	hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
	if (!isNew) {
	    /*
	     * If the deletion callback recreated the command, just throw away
	     * the new command (if we try to delete it again, we could get
	     * stuck in an infinite loop).
	     */

	     ckfree((char *) Tcl_GetHashValue(hPtr));
	}
    } else {
	/*
	 * The list of command exported from the namespace might have changed.
	 * However, we do not need to recompute this just yet; next time we
	 * need the info will be soon enough.
	 */

	TclInvalidateNsCmdLookup(nsPtr);
	TclInvalidateNsPath(nsPtr);
    }
    cmdPtr = (Command *) ckalloc(sizeof(Command));
    Tcl_SetHashValue(hPtr, cmdPtr);
    cmdPtr->hPtr = hPtr;
    cmdPtr->nsPtr = nsPtr;
    cmdPtr->refCount = 1;
    cmdPtr->cmdEpoch = 0;
    cmdPtr->compileProc = NULL;
    cmdPtr->objProc = TclInvokeStringCommand;
    cmdPtr->objClientData = cmdPtr;
    cmdPtr->proc = proc;
    cmdPtr->clientData = clientData;
    cmdPtr->deleteProc = deleteProc;
    cmdPtr->deleteData = clientData;
    cmdPtr->flags = 0;
    cmdPtr->importRefPtr = NULL;
    cmdPtr->tracePtr = NULL;

    /*
     * Plug in any existing import references found above. Be sure to update
     * all of these references to point to the new command.
     */

    if (oldRefPtr != NULL) {
	cmdPtr->importRefPtr = oldRefPtr;
	while (oldRefPtr != NULL) {
	    refCmdPtr = oldRefPtr->importedCmdPtr;
	    dataPtr = refCmdPtr->objClientData;
	    dataPtr->realCmdPtr = cmdPtr;
	    oldRefPtr = oldRefPtr->nextPtr;
	}
    }

    /*
     * We just created a command, so in its namespace and all of its parent
     * namespaces, it may shadow global commands with the same name. If any
     * shadowed commands are found, invalidate all cached command references
     * in the affected namespaces.
     */

    TclResetShadowedCmdRefs(interp, cmdPtr);
    return (Tcl_Command) cmdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateObjCommand --
 *
 *	Define a new object-based command in a command table.
 *
 * Results:
 *	The return value is a token for the command, which can be used in
 *	future calls to Tcl_GetCommandName.
 *
 * Side effects:
 *	If no command named "cmdName" already exists for interp, one is
 *	created. Otherwise, if a command does exist, then if the object-based
 *	Tcl_ObjCmdProc is TclInvokeStringCommand, we assume Tcl_CreateCommand
 *	was called previously for the same command and just set its
 *	Tcl_ObjCmdProc to the argument "proc"; otherwise, we delete the old
 *	command.
 *
 *	In the future, during bytecode evaluation when "cmdName" is seen as
 *	the name of a command by Tcl_EvalObj or Tcl_Eval, the object-based
 *	Tcl_ObjCmdProc proc will be called. When the command is deleted from
 *	the table, deleteProc will be called. See the manual entry for details
 *	on the calling sequence.
 *
 *----------------------------------------------------------------------
 */

Tcl_Command
Tcl_CreateObjCommand(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *cmdName,	/* Name of command. If it contains namespace
				 * qualifiers, the new command is put in the
				 * specified namespace; otherwise it is put in
				 * the global namespace. */
    Tcl_ObjCmdProc *proc,	/* Object-based function to associate with
				 * name. */
    ClientData clientData,	/* Arbitrary value to pass to object
    				 * function. */
    Tcl_CmdDeleteProc *deleteProc)
				/* If not NULL, gives a function to call when
				 * this command is deleted. */
{
    Interp *iPtr = (Interp *) interp;
    ImportRef *oldRefPtr = NULL;
    Namespace *nsPtr, *dummy1, *dummy2;
    Command *cmdPtr, *refCmdPtr;
    Tcl_HashEntry *hPtr;
    const char *tail;
    int isNew;
    ImportedCmdData *dataPtr;

    if (iPtr->flags & DELETED) {
	/*
	 * The interpreter is being deleted. Don't create any new commands;
	 * it's not safe to muck with the interpreter anymore.
	 */

	return (Tcl_Command) NULL;
    }

    /*
     * Determine where the command should reside. If its name contains
     * namespace qualifiers, we put it in the specified namespace; otherwise,
     * we always put it in the global namespace.
     */

    if (strstr(cmdName, "::") != NULL) {
	TclGetNamespaceForQualName(interp, cmdName, NULL,
		TCL_CREATE_NS_IF_UNKNOWN, &nsPtr, &dummy1, &dummy2, &tail);
	if ((nsPtr == NULL) || (tail == NULL)) {
	    return (Tcl_Command) NULL;
	}
    } else {
	nsPtr = iPtr->globalNsPtr;
	tail = cmdName;
    }

    hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
    TclInvalidateNsPath(nsPtr);
    if (!isNew) {
	cmdPtr = Tcl_GetHashValue(hPtr);

	/*
	 * Command already exists. If its object-based Tcl_ObjCmdProc is
	 * TclInvokeStringCommand, we just set its Tcl_ObjCmdProc to the
	 * argument "proc". Otherwise, we delete the old command.
	 */

	if (cmdPtr->objProc == TclInvokeStringCommand) {
	    cmdPtr->objProc = proc;
	    cmdPtr->objClientData = clientData;
	    cmdPtr->deleteProc = deleteProc;
	    cmdPtr->deleteData = clientData;
	    return (Tcl_Command) cmdPtr;
	}

	/*
	 * Otherwise, we delete the old command. Be careful to preserve any
	 * existing import links so we can restore them down below. That way,
	 * you can redefine a command and its import status will remain
	 * intact.
	 */

	oldRefPtr = cmdPtr->importRefPtr;
	cmdPtr->importRefPtr = NULL;

	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
	hPtr = Tcl_CreateHashEntry(&nsPtr->cmdTable, tail, &isNew);
	if (!isNew) {
	    /*
	     * If the deletion callback recreated the command, just throw away
	     * the new command (if we try to delete it again, we could get
	     * stuck in an infinite loop).
	     */

	     ckfree(Tcl_GetHashValue(hPtr));
	}
    } else {
	/*
	 * The list of command exported from the namespace might have changed.
	 * However, we do not need to recompute this just yet; next time we
	 * need the info will be soon enough.
	 */

	TclInvalidateNsCmdLookup(nsPtr);
    }
    cmdPtr = (Command *) ckalloc(sizeof(Command));
    Tcl_SetHashValue(hPtr, cmdPtr);
    cmdPtr->hPtr = hPtr;
    cmdPtr->nsPtr = nsPtr;
    cmdPtr->refCount = 1;
    cmdPtr->cmdEpoch = 0;
    cmdPtr->compileProc = NULL;
    cmdPtr->objProc = proc;
    cmdPtr->objClientData = clientData;
    cmdPtr->proc = TclInvokeObjectCommand;
    cmdPtr->clientData = cmdPtr;
    cmdPtr->deleteProc = deleteProc;
    cmdPtr->deleteData = clientData;
    cmdPtr->flags = 0;
    cmdPtr->importRefPtr = NULL;
    cmdPtr->tracePtr = NULL;

    /*
     * Plug in any existing import references found above. Be sure to update
     * all of these references to point to the new command.
     */

    if (oldRefPtr != NULL) {
	cmdPtr->importRefPtr = oldRefPtr;
	while (oldRefPtr != NULL) {
	    refCmdPtr = oldRefPtr->importedCmdPtr;
	    dataPtr = refCmdPtr->objClientData;
	    dataPtr->realCmdPtr = cmdPtr;
	    oldRefPtr = oldRefPtr->nextPtr;
	}
    }

    /*
     * We just created a command, so in its namespace and all of its parent
     * namespaces, it may shadow global commands with the same name. If any
     * shadowed commands are found, invalidate all cached command references
     * in the affected namespaces.
     */

    TclResetShadowedCmdRefs(interp, cmdPtr);
    return (Tcl_Command) cmdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TclInvokeStringCommand --
 *
 *	"Wrapper" Tcl_ObjCmdProc used to call an existing string-based
 *	Tcl_CmdProc if no object-based function exists for a command. A
 *	pointer to this function is stored as the Tcl_ObjCmdProc in a Command
 *	structure. It simply turns around and calls the string Tcl_CmdProc in
 *	the Command structure.
 *
 * Results:
 *	A standard Tcl object result value.
 *
 * Side effects:
 *	Besides those side effects of the called Tcl_CmdProc,
 *	TclInvokeStringCommand allocates and frees storage.
 *
 *----------------------------------------------------------------------
 */

int
TclInvokeStringCommand(
    ClientData clientData,	/* Points to command's Command structure. */
    Tcl_Interp *interp,		/* Current interpreter. */
    register int objc,		/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Command *cmdPtr = clientData;
    int i, result;
    const char **argv = (const char **)
	    TclStackAlloc(interp, (unsigned)(objc + 1) * sizeof(char *));

    for (i = 0;  i < objc;  i++) {
	argv[i] = Tcl_GetString(objv[i]);
    }
    argv[objc] = 0;

    /*
     * Invoke the command's string-based Tcl_CmdProc.
     */

    result = (*cmdPtr->proc)(cmdPtr->clientData, interp, objc, argv);

    TclStackFree(interp, (void *) argv);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclInvokeObjectCommand --
 *
 *	"Wrapper" Tcl_CmdProc used to call an existing object-based
 *	Tcl_ObjCmdProc if no string-based function exists for a command. A
 *	pointer to this function is stored as the Tcl_CmdProc in a Command
 *	structure. It simply turns around and calls the object Tcl_ObjCmdProc
 *	in the Command structure.
 *
 * Results:
 *	A standard Tcl string result value.
 *
 * Side effects:
 *	Besides those side effects of the called Tcl_CmdProc,
 *	TclInvokeStringCommand allocates and frees storage.
 *
 *----------------------------------------------------------------------
 */

int
TclInvokeObjectCommand(
    ClientData clientData,	/* Points to command's Command structure. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int argc,			/* Number of arguments. */
    register const char **argv)	/* Argument strings. */
{
    Command *cmdPtr = (Command *) clientData;
    Tcl_Obj *objPtr;
    int i, length, result;
    Tcl_Obj **objv = (Tcl_Obj **)
	    TclStackAlloc(interp, (unsigned)(argc * sizeof(Tcl_Obj *)));

    for (i = 0;  i < argc;  i++) {
	length = strlen(argv[i]);
	TclNewStringObj(objPtr, argv[i], length);
	Tcl_IncrRefCount(objPtr);
	objv[i] = objPtr;
    }

    /*
     * Invoke the command's object-based Tcl_ObjCmdProc.
     */

    result = (*cmdPtr->objProc)(cmdPtr->objClientData, interp, argc, objv);

    /*
     * Move the interpreter's object result to the string result, then reset
     * the object result.
     */

    (void) Tcl_GetStringResult(interp);

    /*
     * Decrement the ref counts for the argument objects created above, then
     * free the objv array if malloc'ed storage was used.
     */

    for (i = 0;  i < argc;  i++) {
	objPtr = objv[i];
	Tcl_DecrRefCount(objPtr);
    }
    TclStackFree(interp, objv);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclRenameCommand --
 *
 *	Called to give an existing Tcl command a different name. Both the old
 *	command name and the new command name can have "::" namespace
 *	qualifiers. If the new command has a different namespace context, the
 *	command will be moved to that namespace and will execute in the
 *	context of that new namespace.
 *
 *	If the new command name is NULL or the null string, the command is
 *	deleted.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	If anything goes wrong, an error message is returned in the
 *	interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

int
TclRenameCommand(
    Tcl_Interp *interp,		/* Current interpreter. */
    const char *oldName,	/* Existing command name. */
    const char *newName)	/* New command name. */
{
    Interp *iPtr = (Interp *) interp;
    const char *newTail;
    Namespace *cmdNsPtr, *newNsPtr, *dummy1, *dummy2;
    Tcl_Command cmd;
    Command *cmdPtr;
    Tcl_HashEntry *hPtr, *oldHPtr;
    int isNew, result;
    Tcl_Obj *oldFullName;
    Tcl_DString newFullName;

    /*
     * Find the existing command. An error is returned if cmdName can't be
     * found.
     */

    cmd = Tcl_FindCommand(interp, oldName, NULL, /*flags*/ 0);
    cmdPtr = (Command *) cmd;
    if (cmdPtr == NULL) {
	Tcl_AppendResult(interp, "can't ",
		((newName == NULL)||(*newName == '\0'))? "delete":"rename",
		" \"", oldName, "\": command doesn't exist", NULL);
	return TCL_ERROR;
    }
    cmdNsPtr = cmdPtr->nsPtr;
    oldFullName = Tcl_NewObj();
    Tcl_IncrRefCount(oldFullName);
    Tcl_GetCommandFullName(interp, cmd, oldFullName);

    /*
     * If the new command name is NULL or empty, delete the command. Do this
     * with Tcl_DeleteCommandFromToken, since we already have the command.
     */

    if ((newName == NULL) || (*newName == '\0')) {
	Tcl_DeleteCommandFromToken(interp, cmd);
	result = TCL_OK;
	goto done;
    }

    /*
     * Make sure that the destination command does not already exist. The
     * rename operation is like creating a command, so we should automatically
     * create the containing namespaces just like Tcl_CreateCommand would.
     */

    TclGetNamespaceForQualName(interp, newName, NULL,
	    TCL_CREATE_NS_IF_UNKNOWN, &newNsPtr, &dummy1, &dummy2, &newTail);

    if ((newNsPtr == NULL) || (newTail == NULL)) {
	Tcl_AppendResult(interp, "can't rename to \"", newName,
		"\": bad command name", NULL);
	result = TCL_ERROR;
	goto done;
    }
    if (Tcl_FindHashEntry(&newNsPtr->cmdTable, newTail) != NULL) {
	Tcl_AppendResult(interp, "can't rename to \"", newName,
		 "\": command already exists", NULL);
	result = TCL_ERROR;
	goto done;
    }

    /*
     * Warning: any changes done in the code here are likely to be needed in
     * Tcl_HideCommand() code too (until the common parts are extracted out).
     * - dl
     */

    /*
     * Put the command in the new namespace so we can check for an alias loop.
     * Since we are adding a new command to a namespace, we must handle any
     * shadowing of the global commands that this might create.
     */

    oldHPtr = cmdPtr->hPtr;
    hPtr = Tcl_CreateHashEntry(&newNsPtr->cmdTable, newTail, &isNew);
    Tcl_SetHashValue(hPtr, cmdPtr);
    cmdPtr->hPtr = hPtr;
    cmdPtr->nsPtr = newNsPtr;
    TclResetShadowedCmdRefs(interp, cmdPtr);

    /*
     * Now check for an alias loop. If we detect one, put everything back the
     * way it was and report the error.
     */

    result = TclPreventAliasLoop(interp, interp, (Tcl_Command) cmdPtr);
    if (result != TCL_OK) {
	Tcl_DeleteHashEntry(cmdPtr->hPtr);
	cmdPtr->hPtr = oldHPtr;
	cmdPtr->nsPtr = cmdNsPtr;
	goto done;
    }

    /*
     * The list of command exported from the namespace might have changed.
     * However, we do not need to recompute this just yet; next time we need
     * the info will be soon enough. These might refer to the same variable,
     * but that's no big deal.
     */

    TclInvalidateNsCmdLookup(cmdNsPtr);
    TclInvalidateNsCmdLookup(cmdPtr->nsPtr);

    /*
     * Script for rename traces can delete the command "oldName". Therefore
     * increment the reference count for cmdPtr so that it's Command structure
     * is freed only towards the end of this function by calling
     * TclCleanupCommand.
     *
     * The trace function needs to get a fully qualified name for old and new
     * commands [Tcl bug #651271], or else there's no way for the trace
     * function to get the namespace from which the old command is being
     * renamed!
     */

    Tcl_DStringInit(&newFullName);
    Tcl_DStringAppend(&newFullName, newNsPtr->fullName, -1);
    if (newNsPtr != iPtr->globalNsPtr) {
	Tcl_DStringAppend(&newFullName, "::", 2);
    }
    Tcl_DStringAppend(&newFullName, newTail, -1);
    cmdPtr->refCount++;
    CallCommandTraces(iPtr, cmdPtr, Tcl_GetString(oldFullName),
	    Tcl_DStringValue(&newFullName), TCL_TRACE_RENAME);
    Tcl_DStringFree(&newFullName);

    /*
     * The new command name is okay, so remove the command from its current
     * namespace. This is like deleting the command, so bump the cmdEpoch to
     * invalidate any cached references to the command.
     */

    Tcl_DeleteHashEntry(oldHPtr);
    cmdPtr->cmdEpoch++;

    /*
     * If the command being renamed has a compile function, increment the
     * interpreter's compileEpoch to invalidate its compiled code. This makes
     * sure that we don't later try to execute old code compiled for the
     * now-renamed command.
     */

    if (cmdPtr->compileProc != NULL) {
	iPtr->compileEpoch++;
    }

    /*
     * Now free the Command structure, if the "oldName" command has been
     * deleted by invocation of rename traces.
     */

    TclCleanupCommandMacro(cmdPtr);
    result = TCL_OK;

  done:
    TclDecrRefCount(oldFullName);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetCommandInfo --
 *
 *	Modifies various information about a Tcl command. Note that this
 *	function will not change a command's namespace; use TclRenameCommand
 *	to do that. Also, the isNativeObjectProc member of *infoPtr is
 *	ignored.
 *
 * Results:
 *	If cmdName exists in interp, then the information at *infoPtr is
 *	stored with the command in place of the current information and 1 is
 *	returned. If the command doesn't exist then 0 is returned.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetCommandInfo(
    Tcl_Interp *interp,		/* Interpreter in which to look for
				 * command. */
    const char *cmdName,	/* Name of desired command. */
    const Tcl_CmdInfo *infoPtr)	/* Where to find information to store in the
				 * command. */
{
    Tcl_Command cmd;

    cmd = Tcl_FindCommand(interp, cmdName, NULL, /*flags*/ 0);
    return Tcl_SetCommandInfoFromToken(cmd, infoPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetCommandInfoFromToken --
 *
 *	Modifies various information about a Tcl command. Note that this
 *	function will not change a command's namespace; use TclRenameCommand
 *	to do that. Also, the isNativeObjectProc member of *infoPtr is
 *	ignored.
 *
 * Results:
 *	If cmdName exists in interp, then the information at *infoPtr is
 *	stored with the command in place of the current information and 1 is
 *	returned. If the command doesn't exist then 0 is returned.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetCommandInfoFromToken(
    Tcl_Command cmd,
    const Tcl_CmdInfo *infoPtr)
{
    Command *cmdPtr;		/* Internal representation of the command */

    if (cmd == (Tcl_Command) NULL) {
	return 0;
    }

    /*
     * The isNativeObjectProc and nsPtr members of *infoPtr are ignored.
     */

    cmdPtr = (Command *) cmd;
    cmdPtr->proc = infoPtr->proc;
    cmdPtr->clientData = infoPtr->clientData;
    if (infoPtr->objProc == NULL) {
	cmdPtr->objProc = TclInvokeStringCommand;
	cmdPtr->objClientData = cmdPtr;
    } else {
	cmdPtr->objProc = infoPtr->objProc;
	cmdPtr->objClientData = infoPtr->objClientData;
    }
    cmdPtr->deleteProc = infoPtr->deleteProc;
    cmdPtr->deleteData = infoPtr->deleteData;
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandInfo --
 *
 *	Returns various information about a Tcl command.
 *
 * Results:
 *	If cmdName exists in interp, then *infoPtr is modified to hold
 *	information about cmdName and 1 is returned. If the command doesn't
 *	exist then 0 is returned and *infoPtr isn't modified.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetCommandInfo(
    Tcl_Interp *interp,		/* Interpreter in which to look for
				 * command. */
    const char *cmdName,	/* Name of desired command. */
    Tcl_CmdInfo *infoPtr)	/* Where to store information about
				 * command. */
{
    Tcl_Command cmd;

    cmd = Tcl_FindCommand(interp, cmdName, NULL, /*flags*/ 0);
    return Tcl_GetCommandInfoFromToken(cmd, infoPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandInfoFromToken --
 *
 *	Returns various information about a Tcl command.
 *
 * Results:
 *	Copies information from the command identified by 'cmd' into a
 *	caller-supplied structure and returns 1. If the 'cmd' is NULL, leaves
 *	the structure untouched and returns 0.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetCommandInfoFromToken(
    Tcl_Command cmd,
    Tcl_CmdInfo *infoPtr)
{
    Command *cmdPtr;		/* Internal representation of the command */

    if (cmd == (Tcl_Command) NULL) {
	return 0;
    }

    /*
     * Set isNativeObjectProc 1 if objProc was registered by a call to
     * Tcl_CreateObjCommand. Otherwise set it to 0.
     */

    cmdPtr = (Command *) cmd;
    infoPtr->isNativeObjectProc =
	    (cmdPtr->objProc != TclInvokeStringCommand);
    infoPtr->objProc = cmdPtr->objProc;
    infoPtr->objClientData = cmdPtr->objClientData;
    infoPtr->proc = cmdPtr->proc;
    infoPtr->clientData = cmdPtr->clientData;
    infoPtr->deleteProc = cmdPtr->deleteProc;
    infoPtr->deleteData = cmdPtr->deleteData;
    infoPtr->namespacePtr = (Tcl_Namespace *) cmdPtr->nsPtr;

    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandName --
 *
 *	Given a token returned by Tcl_CreateCommand, this function returns the
 *	current name of the command (which may have changed due to renaming).
 *
 * Results:
 *	The return value is the name of the given command.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_GetCommandName(
    Tcl_Interp *interp,		/* Interpreter containing the command. */
    Tcl_Command command)	/* Token for command returned by a previous
				 * call to Tcl_CreateCommand. The command must
				 * not have been deleted. */
{
    Command *cmdPtr = (Command *) command;

    if ((cmdPtr == NULL) || (cmdPtr->hPtr == NULL)) {
	/*
	 * This should only happen if command was "created" after the
	 * interpreter began to be deleted, so there isn't really any command.
	 * Just return an empty string.
	 */

	return "";
    }

    return Tcl_GetHashKey(cmdPtr->hPtr->tablePtr, cmdPtr->hPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCommandFullName --
 *
 *	Given a token returned by, e.g., Tcl_CreateCommand or Tcl_FindCommand,
 *	this function appends to an object the command's full name, qualified
 *	by a sequence of parent namespace names. The command's fully-qualified
 *	name may have changed due to renaming.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The command's fully-qualified name is appended to the string
 *	representation of objPtr.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_GetCommandFullName(
    Tcl_Interp *interp,		/* Interpreter containing the command. */
    Tcl_Command command,	/* Token for command returned by a previous
				 * call to Tcl_CreateCommand. The command must
				 * not have been deleted. */
    Tcl_Obj *objPtr)		/* Points to the object onto which the
				 * command's full name is appended. */

{
    Interp *iPtr = (Interp *) interp;
    register Command *cmdPtr = (Command *) command;
    char *name;

    /*
     * Add the full name of the containing namespace, followed by the "::"
     * separator, and the command name.
     */

    if (cmdPtr != NULL) {
	if (cmdPtr->nsPtr != NULL) {
	    Tcl_AppendToObj(objPtr, cmdPtr->nsPtr->fullName, -1);
	    if (cmdPtr->nsPtr != iPtr->globalNsPtr) {
		Tcl_AppendToObj(objPtr, "::", 2);
	    }
	}
	if (cmdPtr->hPtr != NULL) {
	    name = Tcl_GetHashKey(cmdPtr->hPtr->tablePtr, cmdPtr->hPtr);
	    Tcl_AppendToObj(objPtr, name, -1);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteCommand --
 *
 *	Remove the given command from the given interpreter.
 *
 * Results:
 *	0 is returned if the command was deleted successfully. -1 is returned
 *	if there didn't exist a command by that name.
 *
 * Side effects:
 *	cmdName will no longer be recognized as a valid command for interp.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_DeleteCommand(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * a previous Tcl_CreateInterp call). */
    const char *cmdName)	/* Name of command to remove. */
{
    Tcl_Command cmd;

    /*
     * Find the desired command and delete it.
     */

    cmd = Tcl_FindCommand(interp, cmdName, NULL, /*flags*/ 0);
    if (cmd == (Tcl_Command) NULL) {
	return -1;
    }
    return Tcl_DeleteCommandFromToken(interp, cmd);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteCommandFromToken --
 *
 *	Removes the given command from the given interpreter. This function
 *	resembles Tcl_DeleteCommand, but takes a Tcl_Command token instead of
 *	a command name for efficiency.
 *
 * Results:
 *	0 is returned if the command was deleted successfully. -1 is returned
 *	if there didn't exist a command by that name.
 *
 * Side effects:
 *	The command specified by "cmd" will no longer be recognized as a valid
 *	command for "interp".
 *
 *----------------------------------------------------------------------
 */

int
Tcl_DeleteCommandFromToken(
    Tcl_Interp *interp,		/* Token for command interpreter returned by a
				 * previous call to Tcl_CreateInterp. */
    Tcl_Command cmd)		/* Token for command to delete. */
{
    Interp *iPtr = (Interp *) interp;
    Command *cmdPtr = (Command *) cmd;
    ImportRef *refPtr, *nextRefPtr;
    Tcl_Command importCmd;

    /*
     * Bump the command epoch counter. This will invalidate all cached
     * references that point to this command.
     */

    cmdPtr->cmdEpoch++;

    /*
     * The code here is tricky. We can't delete the hash table entry before
     * invoking the deletion callback because there are cases where the
     * deletion callback needs to invoke the command (e.g. object systems such
     * as OTcl). However, this means that the callback could try to delete or
     * rename the command. The deleted flag allows us to detect these cases
     * and skip nested deletes.
     */

    if (cmdPtr->flags & CMD_IS_DELETED) {
	/*
	 * Another deletion is already in progress. Remove the hash table
	 * entry now, but don't invoke a callback or free the command
	 * structure. Take care to only remove the hash entry if it has not
	 * already been removed; otherwise if we manage to hit this function
	 * three times, everything goes up in smoke. [Bug 1220058]
	 */

	if (cmdPtr->hPtr != NULL) {
	    Tcl_DeleteHashEntry(cmdPtr->hPtr);
	    cmdPtr->hPtr = NULL;
	}
	return 0;
    }

    /*
     * We must delete this command, even though both traces and delete procs
     * may try to avoid this (renaming the command etc). Also traces and
     * delete procs may try to delete the command themsevles. This flag
     * declares that a delete is in progress and that recursive deletes should
     * be ignored.
     */

    cmdPtr->flags |= CMD_IS_DELETED;

    /*
     * Call trace functions for the command being deleted. Then delete its
     * traces.
     */

    if (cmdPtr->tracePtr != NULL) {
	CommandTrace *tracePtr;
	CallCommandTraces(iPtr,cmdPtr,NULL,NULL,TCL_TRACE_DELETE);

	/*
	 * Now delete these traces.
	 */

	tracePtr = cmdPtr->tracePtr;
	while (tracePtr != NULL) {
	    CommandTrace *nextPtr = tracePtr->nextPtr;
	    if ((--tracePtr->refCount) <= 0) {
		ckfree((char *) tracePtr);
	    }
	    tracePtr = nextPtr;
	}
	cmdPtr->tracePtr = NULL;
    }

    /*
     * The list of command exported from the namespace might have changed.
     * However, we do not need to recompute this just yet; next time we need
     * the info will be soon enough.
     */

    TclInvalidateNsCmdLookup(cmdPtr->nsPtr);

    /*
     * If the command being deleted has a compile function, increment the
     * interpreter's compileEpoch to invalidate its compiled code. This makes
     * sure that we don't later try to execute old code compiled with
     * command-specific (i.e., inline) bytecodes for the now-deleted command.
     * This field is checked in Tcl_EvalObj and ObjInterpProc, and code whose
     * compilation epoch doesn't match is recompiled.
     */

    if (cmdPtr->compileProc != NULL) {
	iPtr->compileEpoch++;
    }

    if (cmdPtr->deleteProc != NULL) {
	/*
	 * Delete the command's client data. If this was an imported command
	 * created when a command was imported into a namespace, this client
	 * data will be a pointer to a ImportedCmdData structure describing
	 * the "real" command that this imported command refers to.
	 */

	/*
	 * If you are getting a crash during the call to deleteProc and
	 * cmdPtr->deleteProc is a pointer to the function free(), the most
	 * likely cause is that your extension allocated memory for the
	 * clientData argument to Tcl_CreateObjCommand() with the ckalloc()
	 * macro and you are now trying to deallocate this memory with free()
	 * instead of ckfree(). You should pass a pointer to your own method
	 * that calls ckfree().
	 */

	(*cmdPtr->deleteProc)(cmdPtr->deleteData);
    }

    /*
     * If this command was imported into other namespaces, then imported
     * commands were created that refer back to this command. Delete these
     * imported commands now.
     */

    for (refPtr = cmdPtr->importRefPtr;  refPtr != NULL;
	    refPtr = nextRefPtr) {
	nextRefPtr = refPtr->nextPtr;
	importCmd = (Tcl_Command) refPtr->importedCmdPtr;
	Tcl_DeleteCommandFromToken(interp, importCmd);
    }

    /*
     * Don't use hPtr to delete the hash entry here, because it's possible
     * that the deletion callback renamed the command. Instead, use
     * cmdPtr->hptr, and make sure that no-one else has already deleted the
     * hash entry.
     */

    if (cmdPtr->hPtr != NULL) {
	Tcl_DeleteHashEntry(cmdPtr->hPtr);
	cmdPtr->hPtr = NULL;
    }

    /*
     * Mark the Command structure as no longer valid. This allows
     * TclExecuteByteCode to recognize when a Command has logically been
     * deleted and a pointer to this Command structure cached in a CmdName
     * object is invalid. TclExecuteByteCode will look up the command again in
     * the interpreter's command hashtable.
     */

    cmdPtr->objProc = NULL;

    /*
     * Now free the Command structure, unless there is another reference to it
     * from a CmdName Tcl object in some ByteCode code sequence. In that case,
     * delay the cleanup until all references are either discarded (when a
     * ByteCode is freed) or replaced by a new reference (when a cached
     * CmdName Command reference is found to be invalid and TclExecuteByteCode
     * looks up the command in the command hashtable).
     */

    TclCleanupCommandMacro(cmdPtr);
    return 0;
}

static char *
CallCommandTraces(
    Interp *iPtr,		/* Interpreter containing command. */
    Command *cmdPtr,		/* Command whose traces are to be invoked. */
    const char *oldName,	/* Command's old name, or NULL if we must get
				 * the name from cmdPtr */
    const char *newName,	/* Command's new name, or NULL if the command
				 * is not being renamed */
    int flags)			/* Flags indicating the type of traces to
				 * trigger, either TCL_TRACE_DELETE or
				 * TCL_TRACE_RENAME. */
{
    register CommandTrace *tracePtr;
    ActiveCommandTrace active;
    char *result;
    Tcl_Obj *oldNamePtr = NULL;
    Tcl_InterpState state = NULL;

    if (cmdPtr->flags & CMD_TRACE_ACTIVE) {
	/*
	 * While a rename trace is active, we will not process any more rename
	 * traces; while a delete trace is active we will never reach here -
	 * because Tcl_DeleteCommandFromToken checks for the condition
	 * (cmdPtr->flags & CMD_IS_DELETED) and returns immediately when a
	 * command deletion is in progress. For all other traces, delete
	 * traces will not be invoked but a call to TraceCommandProc will
	 * ensure that tracePtr->clientData is freed whenever the command
	 * "oldName" is deleted.
	 */

	if (cmdPtr->flags & TCL_TRACE_RENAME) {
	    flags &= ~TCL_TRACE_RENAME;
	}
	if (flags == 0) {
	    return NULL;
	}
    }
    cmdPtr->flags |= CMD_TRACE_ACTIVE;
    cmdPtr->refCount++;

    result = NULL;
    active.nextPtr = iPtr->activeCmdTracePtr;
    active.reverseScan = 0;
    iPtr->activeCmdTracePtr = &active;

    if (flags & TCL_TRACE_DELETE) {
	flags |= TCL_TRACE_DESTROYED;
    }
    active.cmdPtr = cmdPtr;

    Tcl_Preserve(iPtr);

    for (tracePtr = cmdPtr->tracePtr; tracePtr != NULL;
	    tracePtr = active.nextTracePtr) {
	active.nextTracePtr = tracePtr->nextPtr;
	if (!(tracePtr->flags & flags)) {
	    continue;
	}
	cmdPtr->flags |= tracePtr->flags;
	if (oldName == NULL) {
	    TclNewObj(oldNamePtr);
	    Tcl_IncrRefCount(oldNamePtr);
	    Tcl_GetCommandFullName((Tcl_Interp *) iPtr,
		    (Tcl_Command) cmdPtr, oldNamePtr);
	    oldName = TclGetString(oldNamePtr);
	}
	tracePtr->refCount++;
	if (state == NULL) {
	    state = Tcl_SaveInterpState((Tcl_Interp *) iPtr, TCL_OK);
	}
	(*tracePtr->traceProc)(tracePtr->clientData,
		(Tcl_Interp *) iPtr, oldName, newName, flags);
	cmdPtr->flags &= ~tracePtr->flags;
	if ((--tracePtr->refCount) <= 0) {
	    ckfree((char *) tracePtr);
	}
    }

    if (state) {
	Tcl_RestoreInterpState((Tcl_Interp *) iPtr, state);
    }

    /*
     * If a new object was created to hold the full oldName, free it now.
     */

    if (oldNamePtr != NULL) {
	TclDecrRefCount(oldNamePtr);
    }

    /*
     * Restore the variable's flags, remove the record of our active traces,
     * and then return.
     */

    cmdPtr->flags &= ~CMD_TRACE_ACTIVE;
    cmdPtr->refCount--;
    iPtr->activeCmdTracePtr = active.nextPtr;
    Tcl_Release(iPtr);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * GetCommandSource --
 *
 *	This function returns a Tcl_Obj with the full source string for the
 *	command. This insures that traces get a correct NUL-terminated command
 *	string.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
GetCommandSource(
    Interp *iPtr,
    const char *command,
    int numChars,
    int objc,
    Tcl_Obj *const objv[])
{
    if (!command) {
	return Tcl_NewListObj(objc, objv);
    }
    if (command == (char *) -1) {
	command = TclGetSrcInfoForCmd(iPtr, &numChars);
    }
    return Tcl_NewStringObj(command, numChars);
}

/*
 *----------------------------------------------------------------------
 *
 * TclCleanupCommand --
 *
 *	This function frees up a Command structure unless it is still
 *	referenced from an interpreter's command hashtable or from a CmdName
 *	Tcl object representing the name of a command in a ByteCode
 *	instruction sequence.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory gets freed unless a reference to the Command structure still
 *	exists. In that case the cleanup is delayed until the command is
 *	deleted or when the last ByteCode referring to it is freed.
 *
 *----------------------------------------------------------------------
 */

void
TclCleanupCommand(
    register Command *cmdPtr)	/* Points to the Command structure to
				 * be freed. */
{
    cmdPtr->refCount--;
    if (cmdPtr->refCount <= 0) {
	ckfree((char *) cmdPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateMathFunc --
 *
 *	Creates a new math function for expressions in a given interpreter.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The Tcl function defined by "name" is created or redefined. If the
 *	function already exists then its definition is replaced; this includes
 *	the builtin functions. Redefining a builtin function forces all
 *	existing code to be invalidated since that code may be compiled using
 *	an instruction specific to the replaced function. In addition,
 *	redefioning a non-builtin function will force existing code to be
 *	invalidated if the number of arguments has changed.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_CreateMathFunc(
    Tcl_Interp *interp,		/* Interpreter in which function is to be
				 * available. */
    const char *name,		/* Name of function (e.g. "sin"). */
    int numArgs,		/* Nnumber of arguments required by
				 * function. */
    Tcl_ValueType *argTypes,	/* Array of types acceptable for each
				 * argument. */
    Tcl_MathProc *proc,		/* C function that implements the math
				 * function. */
    ClientData clientData)	/* Additional value to pass to the
				 * function. */
{
    Tcl_DString bigName;
    OldMathFuncData *data = (OldMathFuncData *)
	    ckalloc(sizeof(OldMathFuncData));

    data->proc = proc;
    data->numArgs = numArgs;
    data->argTypes = (Tcl_ValueType *)
	    ckalloc(numArgs * sizeof(Tcl_ValueType));
    memcpy(data->argTypes, argTypes, numArgs * sizeof(Tcl_ValueType));
    data->clientData = clientData;

    Tcl_DStringInit(&bigName);
    Tcl_DStringAppend(&bigName, "::tcl::mathfunc::", -1);
    Tcl_DStringAppend(&bigName, name, -1);

    Tcl_CreateObjCommand(interp, Tcl_DStringValue(&bigName),
	    OldMathFuncProc, data, OldMathFuncDeleteProc);
    Tcl_DStringFree(&bigName);
}

/*
 *----------------------------------------------------------------------
 *
 * OldMathFuncProc --
 *
 *	Dispatch to a math function created with Tcl_CreateMathFunc
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	Whatever the math function does.
 *
 *----------------------------------------------------------------------
 */

static int
OldMathFuncProc(
    ClientData clientData,	/* Ponter to OldMathFuncData describing the
				 * function being called */
    Tcl_Interp *interp,		/* Tcl interpreter */
    int objc,			/* Actual parameter count */
    Tcl_Obj *const *objv)	/* Parameter vector */
{
    Tcl_Obj *valuePtr;
    OldMathFuncData *dataPtr = clientData;
    Tcl_Value funcResult, *args;
    int result;
    int j, k;
    double d;

    /*
     * Check argument count.
     */

    if (objc != dataPtr->numArgs + 1) {
	MathFuncWrongNumArgs(interp, dataPtr->numArgs+1, objc, objv);
	return TCL_ERROR;
    }

    /*
     * Convert arguments from Tcl_Obj's to Tcl_Value's.
     */

    args = (Tcl_Value *) ckalloc(dataPtr->numArgs * sizeof(Tcl_Value));
    for (j = 1, k = 0; j < objc; ++j, ++k) {

	/* TODO: Convert to TclGetNumberFromObj() ? */
	valuePtr = objv[j];
	result = Tcl_GetDoubleFromObj(NULL, valuePtr, &d);
#ifdef ACCEPT_NAN
	if ((result != TCL_OK) && (valuePtr->typePtr == &tclDoubleType)) {
	    d = valuePtr->internalRep.doubleValue;
	    result = TCL_OK;
	}
#endif
	if (result != TCL_OK) {
	    /*
	     * We have a non-numeric argument.
	     */

	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "argument to math function didn't have numeric value",-1));
	    TclCheckBadOctal(interp, Tcl_GetString(valuePtr));
	    ckfree((char *)args);
	    return TCL_ERROR;
	}

	/*
	 * Copy the object's numeric value to the argument record, converting
	 * it if necessary.
	 *
	 * NOTE: no bignum support; use the new mathfunc interface for that.
	 */

	args[k].type = dataPtr->argTypes[k];
	switch (args[k].type) {
	case TCL_EITHER:
	    if (Tcl_GetLongFromObj(NULL, valuePtr, &(args[k].intValue))
		    == TCL_OK) {
		args[k].type = TCL_INT;
		break;
	    }
	    if (Tcl_GetWideIntFromObj(interp, valuePtr, &(args[k].wideValue))
		    == TCL_OK) {
		args[k].type = TCL_WIDE_INT;
		break;
	    }
	    args[k].type = TCL_DOUBLE;
	    /* FALLTHROUGH */

	case TCL_DOUBLE:
	    args[k].doubleValue = d;
	    break;
	case TCL_INT:
	    if (ExprIntFunc(NULL, interp, 2, &(objv[j-1])) != TCL_OK) {
		ckfree((char *)args);
		return TCL_ERROR;
	    }
	    valuePtr = Tcl_GetObjResult(interp);
	    Tcl_GetLongFromObj(NULL, valuePtr, &(args[k].intValue));
	    Tcl_ResetResult(interp);
	    break;
	case TCL_WIDE_INT:
	    if (ExprWideFunc(NULL, interp, 2, &(objv[j-1])) != TCL_OK) {
		ckfree((char *)args);
		return TCL_ERROR;
	    }
	    valuePtr = Tcl_GetObjResult(interp);
	    Tcl_GetWideIntFromObj(NULL, valuePtr, &(args[k].wideValue));
	    Tcl_ResetResult(interp);
	    break;
	}
    }

    /*
     * Call the function.
     */

    errno = 0;
    result = (*dataPtr->proc)(dataPtr->clientData, interp, args, &funcResult);
    ckfree((char *)args);
    if (result != TCL_OK) {
	return result;
    }

    /*
     * Return the result of the call.
     */

    if (funcResult.type == TCL_INT) {
	TclNewLongObj(valuePtr, funcResult.intValue);
    } else if (funcResult.type == TCL_WIDE_INT) {
	valuePtr = Tcl_NewWideIntObj(funcResult.wideValue);
    } else {
	return CheckDoubleResult(interp, funcResult.doubleValue);
    }
    Tcl_SetObjResult(interp, valuePtr);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * OldMathFuncDeleteProc --
 *
 *	Cleans up after deleting a math function registered with
 *	Tcl_CreateMathFunc
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees allocated memory.
 *
 *----------------------------------------------------------------------
 */

static void
OldMathFuncDeleteProc(
     ClientData clientData)
{
    OldMathFuncData *dataPtr = clientData;

    ckfree((void *) dataPtr->argTypes);
    ckfree((void *) dataPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetMathFuncInfo --
 *
 *	Discovers how a particular math function was created in a given
 *	interpreter.
 *
 * Results:
 *	TCL_OK if it succeeds, TCL_ERROR else (leaving an error message in the
 *	interpreter result if that happens.)
 *
 * Side effects:
 *	If this function succeeds, the variables pointed to by the numArgsPtr
 *	and argTypePtr arguments will be updated to detail the arguments
 *	allowed by the function. The variable pointed to by the procPtr
 *	argument will be set to NULL if the function is a builtin function,
 *	and will be set to the address of the C function used to implement the
 *	math function otherwise (in which case the variable pointed to by the
 *	clientDataPtr argument will also be updated.)
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetMathFuncInfo(
    Tcl_Interp *interp,
    const char *name,
    int *numArgsPtr,
    Tcl_ValueType **argTypesPtr,
    Tcl_MathProc **procPtr,
    ClientData *clientDataPtr)
{
    Tcl_Obj *cmdNameObj;
    Command *cmdPtr;

    /*
     * Get the command that implements the math function.
     */

    TclNewLiteralStringObj(cmdNameObj, "tcl::mathfunc::");
    Tcl_AppendToObj(cmdNameObj, name, -1);
    Tcl_IncrRefCount(cmdNameObj);
    cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, cmdNameObj);
    Tcl_DecrRefCount(cmdNameObj);

    /*
     * Report unknown functions.
     */

    if (cmdPtr == NULL) {
	Tcl_Obj *message;

	TclNewLiteralStringObj(message, "unknown math function \"");
	Tcl_AppendToObj(message, name, -1);
	Tcl_AppendToObj(message, "\"", 1);
	Tcl_SetObjResult(interp, message);
	*numArgsPtr = -1;
	*argTypesPtr = NULL;
	*procPtr = NULL;
	*clientDataPtr = NULL;
	return TCL_ERROR;
    }

    /*
     * Retrieve function info for user defined functions; return dummy
     * information for builtins.
     */

    if (cmdPtr->objProc == &OldMathFuncProc) {
	OldMathFuncData *dataPtr = cmdPtr->clientData;

	*procPtr = dataPtr->proc;
	*numArgsPtr = dataPtr->numArgs;
	*argTypesPtr = dataPtr->argTypes;
	*clientDataPtr = dataPtr->clientData;
    } else {
	*procPtr = NULL;
	*numArgsPtr = -1;
	*argTypesPtr = NULL;
	*procPtr = NULL;
	*clientDataPtr = NULL;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ListMathFuncs --
 *
 *	Produces a list of all the math functions defined in a given
 *	interpreter.
 *
 * Results:
 *	A pointer to a Tcl_Obj structure with a reference count of zero, or
 *	NULL in the case of an error (in which case a suitable error message
 *	will be left in the interpreter result.)
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_ListMathFuncs(
    Tcl_Interp *interp,
    const char *pattern)
{
    Namespace *globalNsPtr = (Namespace *) Tcl_GetGlobalNamespace(interp);
    Namespace *nsPtr;
    Namespace *dummy1NsPtr;
    Namespace *dummy2NsPtr;
    const char *dummyNamePtr;
    Tcl_Obj *result = Tcl_NewObj();

    TclGetNamespaceForQualName(interp, "::tcl::mathfunc",
	    globalNsPtr, TCL_FIND_ONLY_NS | TCL_GLOBAL_ONLY,
	    &nsPtr, &dummy1NsPtr, &dummy2NsPtr, &dummyNamePtr);
    if (nsPtr == NULL) {
	return result;
    }

    if ((pattern != NULL) && TclMatchIsTrivial(pattern)) {
	if (Tcl_FindHashEntry(&nsPtr->cmdTable, pattern) != NULL) {
	    Tcl_ListObjAppendElement(NULL, result,
		    Tcl_NewStringObj(pattern, -1));
	}
    } else {
	Tcl_HashSearch cmdHashSearch;
	Tcl_HashEntry *cmdHashEntry =
		Tcl_FirstHashEntry(&nsPtr->cmdTable,&cmdHashSearch);

	for (; cmdHashEntry != NULL;
		cmdHashEntry = Tcl_NextHashEntry(&cmdHashSearch)) {
	    const char *cmdNamePtr =
		    Tcl_GetHashKey(&nsPtr->cmdTable, cmdHashEntry);

	    if (pattern == NULL || Tcl_StringMatch(cmdNamePtr, pattern)) {
		Tcl_ListObjAppendElement(NULL, result,
			Tcl_NewStringObj(cmdNamePtr, -1));
	    }
	}
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclInterpReady --
 *
 *	Check if an interpreter is ready to eval commands or scripts, i.e., if
 *	it was not deleted and if the nesting level is not too high.
 *
 * Results:
 *	The return value is TCL_OK if it the interpreter is ready, TCL_ERROR
 *	otherwise.
 *
 * Side effects:
 *	The interpreters object and string results are cleared.
 *
 *----------------------------------------------------------------------
 */

int
TclInterpReady(
    Tcl_Interp *interp)
{
    int localInt; /* used for checking the stack */
    register Interp *iPtr = (Interp *) interp;

    /*
     * Reset both the interpreter's string and object results and clear out
     * any previous error information.
     */

    Tcl_ResetResult(interp);

    /*
     * If the interpreter has been deleted, return an error.
     */

    if (iPtr->flags & DELETED) {
	Tcl_ResetResult(interp);
	Tcl_AppendResult(interp,
		"attempt to call eval in deleted interpreter", NULL);
	Tcl_SetErrorCode(interp, "TCL", "IDELETE",
		"attempt to call eval in deleted interpreter", NULL);
	return TCL_ERROR;
    }

    /*
     * Check depth of nested calls to Tcl_Eval: if this gets too large, it's
     * probably because of an infinite loop somewhere.
     */

    if (((iPtr->numLevels) <= iPtr->maxNestingDepth)
	    && CheckCStack(iPtr, &localInt)) {
	return TCL_OK;
    }

    if (!CheckCStack(iPtr, &localInt)) {
	Tcl_AppendResult(interp,
		"out of stack space (infinite loop?)", NULL);
    } else {
	Tcl_AppendResult(interp,
		"too many nested evaluations (infinite loop?)", NULL);
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * TclEvalObjvInternal
 *
 *	This function evaluates a Tcl command that has already been parsed
 *	into words, with one Tcl_Obj holding each word. The caller is
 *	responsible for managing the iPtr->numLevels.
 *
 *      TclEvalObjvInternal is the backend for Tcl_EvalObjv, the bytecode
 *      engine also calls it directly.
 *
 * Results:
 *	The return value is a standard Tcl completion code such as TCL_OK or
 *	TCL_ERROR. A result or error message is left in interp's result. If an
 *	error occurs, this function does NOT add any information to the
 *	errorInfo variable.
 *
 * Side effects:
 *	Depends on the command.
 *
 *----------------------------------------------------------------------
 */

int
TclEvalObjvInternal(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the
				 * command. Also used for error reporting. */
    int objc,			/* Number of words in command. */
    Tcl_Obj *const objv[],	/* An array of pointers to objects that are
				 * the words that make up the command. */
    const char *command,	/* Points to the beginning of the string
				 * representation of the command; this is used
				 * for traces. NULL if the string
				 * representation of the command is unknown is
				 * to be generated from (objc,objv), -1 if it
				 * is to be generated from bytecode
				 * source. This is only needed the traces. */
    int length,			/* Number of bytes in command; if -1, all
				 * characters up to the first null byte are
				 * used. */
    int flags)			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Only
				 * TCL_EVAL_GLOBAL and TCL_EVAL_INVOKE are
				 * currently supported. */
{
    Command *cmdPtr;
    Interp *iPtr = (Interp *) interp;
    Tcl_Obj **newObjv;
    int i;
    CallFrame *savedVarFramePtr = NULL;
    CallFrame *varFramePtr = iPtr->varFramePtr;
    int code = TCL_OK;
    int traceCode = TCL_OK;
    int checkTraces = 1, traced;
    Namespace *savedNsPtr = NULL;
    Namespace *lookupNsPtr = iPtr->lookupNsPtr;
    Tcl_Obj *commandPtr = NULL;

    if (TclInterpReady(interp) == TCL_ERROR) {
	return TCL_ERROR;
    }

    if (objc == 0) {
	return TCL_OK;
    }

    /*
     * If any execution traces rename or delete the current command, we may
     * need (at most) two passes here.
     */

  reparseBecauseOfTraces:

    /*
     * Configure evaluation context to match the requested flags.
     */

    if (flags) {
	if (flags & TCL_EVAL_INVOKE) {
	    savedNsPtr = varFramePtr->nsPtr;
	    if (lookupNsPtr) {
		varFramePtr->nsPtr = lookupNsPtr;
		iPtr->lookupNsPtr = NULL;
	    } else {
		varFramePtr->nsPtr = iPtr->globalNsPtr;
	    }
	} else if ((flags & TCL_EVAL_GLOBAL)
		&& (varFramePtr != iPtr->rootFramePtr) && !savedVarFramePtr) {
	    varFramePtr = iPtr->rootFramePtr;
	    savedVarFramePtr = iPtr->varFramePtr;
	    iPtr->varFramePtr = varFramePtr;
	}
    }

    /*
     * Find the function to execute this command. If there isn't one, then see
     * if there is an unknown command handler registered for this namespace.
     * If so, create a new word array with the handler as the first words and
     * the original command words as arguments. Then call ourselves
     * recursively to execute it.
     */

    cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, objv[0]);
    if (!cmdPtr) {
	goto notFound;
    }

    if (savedNsPtr) {
	varFramePtr->nsPtr = savedNsPtr;
    } else if (iPtr->ensembleRewrite.sourceObjs) {
	/*
	 * TCL_EVAL_INVOKE was not set: clear rewrite rules
	 */

	iPtr->ensembleRewrite.sourceObjs = NULL;
    }

    /*
     * Call trace functions if needed.
     */

    traced = (iPtr->tracePtr || (cmdPtr->flags & CMD_HAS_EXEC_TRACES));
    if (traced && checkTraces) {
	int cmdEpoch = cmdPtr->cmdEpoch;
	int newEpoch;

	/*
	 * Insure that we have a correct nul-terminated command string for the
	 * trace code.
	 */

	commandPtr = GetCommandSource(iPtr, command, length, objc, objv);
	command = TclGetStringFromObj(commandPtr, &length);

	/*
	 * Execute any command or execution traces. Note that we bump up the
	 * command's reference count for the duration of the calling of the
	 * traces so that the structure doesn't go away underneath our feet.
	 */

	cmdPtr->refCount++;
	if (iPtr->tracePtr && (traceCode == TCL_OK)) {
	    traceCode = TclCheckInterpTraces(interp, command, length,
		    cmdPtr, code, TCL_TRACE_ENTER_EXEC, objc, objv);
	}
	if ((cmdPtr->flags & CMD_HAS_EXEC_TRACES) && (traceCode == TCL_OK)) {
	    traceCode = TclCheckExecutionTraces(interp, command, length,
		    cmdPtr, code, TCL_TRACE_ENTER_EXEC, objc, objv);
	}
	newEpoch = cmdPtr->cmdEpoch;
	TclCleanupCommandMacro(cmdPtr);

	/*
	 * If the traces modified/deleted the command or any existing traces,
	 * they will update the command's epoch. When that happens, set
	 * checkTraces is set to 0 to prevent the re-calling of traces (and
	 * any possible infinite loop) and we go back to re-find the command
	 * implementation.
	 */

	if (cmdEpoch != newEpoch) {
	    checkTraces = 0;
	    if (commandPtr) {
		Tcl_DecrRefCount(commandPtr);
	    }
	    goto reparseBecauseOfTraces;
	}
    }

    if (TCL_DTRACE_CMD_ARGS_ENABLED()) {
	char *a[10];
	int i = 0;

	while (i < 10) {
	    a[i] = i < objc ? TclGetString(objv[i]) : NULL; i++;
	}
	TCL_DTRACE_CMD_ARGS(a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7],
		a[8], a[9]);
    }
    if (TCL_DTRACE_CMD_INFO_ENABLED() && iPtr->cmdFramePtr) {
	Tcl_Obj *info = TclInfoFrame(interp, iPtr->cmdFramePtr);
	char *a[4]; int i[2];

	TclDTraceInfo(info, a, i);
	TCL_DTRACE_CMD_INFO(a[0], a[1], a[2], a[3], i[0], i[1]);
	TclDecrRefCount(info);
    }

    /*
     * Finally, invoke the command's Tcl_ObjCmdProc.
     */

    cmdPtr->refCount++;
    iPtr->cmdCount++;
    if (code == TCL_OK && traceCode == TCL_OK
	    && !TclLimitExceeded(iPtr->limit)) {
	if (TCL_DTRACE_CMD_ENTRY_ENABLED()) {
	    TCL_DTRACE_CMD_ENTRY(TclGetString(objv[0]), objc - 1,
		    (Tcl_Obj **)(objv + 1));
	}
	code = (*cmdPtr->objProc)(cmdPtr->objClientData, interp, objc, objv);
	if (TCL_DTRACE_CMD_RETURN_ENABLED()) {
	    TCL_DTRACE_CMD_RETURN(TclGetString(objv[0]), code);
	}
    }

    if (TclAsyncReady(iPtr)) {
	code = Tcl_AsyncInvoke(interp, code);
    }
    if (code == TCL_OK && TclLimitReady(iPtr->limit)) {
	code = Tcl_LimitCheck(interp);
    }

    /*
     * Call 'leave' command traces
     */

    if (traced) {
	if (!(cmdPtr->flags & CMD_IS_DELETED)) {
	    if ((cmdPtr->flags & CMD_HAS_EXEC_TRACES) && traceCode == TCL_OK){
		traceCode = TclCheckExecutionTraces(interp, command, length,
			cmdPtr, code, TCL_TRACE_LEAVE_EXEC, objc, objv);
	    }
	    if (iPtr->tracePtr != NULL && traceCode == TCL_OK) {
		traceCode = TclCheckInterpTraces(interp, command, length,
			cmdPtr, code, TCL_TRACE_LEAVE_EXEC, objc, objv);
	    }
	}

	/*
	 * If one of the trace invocation resulted in error, then change the
	 * result code accordingly. Note, that the interp->result should
	 * already be set correctly by the call to TraceExecutionProc.
	 */

	if (traceCode != TCL_OK) {
	    code = traceCode;
	}
	if (commandPtr) {
	    Tcl_DecrRefCount(commandPtr);
	}
    }

    /*
     * Decrement the reference count of cmdPtr and deallocate it if it has
     * dropped to zero.
     */

    TclCleanupCommandMacro(cmdPtr);

    /*
     * If the interpreter has a non-empty string result, the result object is
     * either empty or stale because some function set interp->result
     * directly. If so, move the string result to the result object, then
     * reset the string result.
     */

    if (*(iPtr->result) != 0) {
	(void) Tcl_GetObjResult(interp);
    }

    if (TCL_DTRACE_CMD_RESULT_ENABLED()) {
	Tcl_Obj *r;

	r = Tcl_GetObjResult(interp);
	TCL_DTRACE_CMD_RESULT(TclGetString(objv[0]), code, TclGetString(r),r);
    }

  done:
    if (savedVarFramePtr) {
	iPtr->varFramePtr = savedVarFramePtr;
    }
    return code;

  notFound:
    {
	Namespace *currNsPtr = NULL;	/* Used to check for and invoke any
					 * registered unknown command handler
					 * for the current namespace (TIP
					 * 181). */
	int newObjc, handlerObjc;
	Tcl_Obj **handlerObjv;

	currNsPtr = varFramePtr->nsPtr;
	if ((currNsPtr == NULL) || (currNsPtr->unknownHandlerPtr == NULL)) {
	    currNsPtr = iPtr->globalNsPtr;
	    if (currNsPtr == NULL) {
		Tcl_Panic("TclEvalObjvInternal: NULL global namespace pointer");
	    }
	}

	/*
	 * Check to see if the resolution namespace has lost its unknown
	 * handler. If so, reset it to "::unknown".
	 */

	if (currNsPtr->unknownHandlerPtr == NULL) {
	    TclNewLiteralStringObj(currNsPtr->unknownHandlerPtr, "::unknown");
	    Tcl_IncrRefCount(currNsPtr->unknownHandlerPtr);
	}

	/*
	 * Get the list of words for the unknown handler and allocate enough
	 * space to hold both the handler prefix and all words of the command
	 * invokation itself.
	 */

	Tcl_ListObjGetElements(NULL, currNsPtr->unknownHandlerPtr,
		&handlerObjc, &handlerObjv);
	newObjc = objc + handlerObjc;
	newObjv = (Tcl_Obj **) TclStackAlloc(interp,
		(int) sizeof(Tcl_Obj *) * newObjc);

	/*
	 * Copy command prefix from unknown handler and add on the real
	 * command's full argument list. Note that we only use memcpy() once
	 * because we have to increment the reference count of all the handler
	 * arguments anyway.
	 */

	for (i = 0; i < handlerObjc; ++i) {
	    newObjv[i] = handlerObjv[i];
	    Tcl_IncrRefCount(newObjv[i]);
	}
	memcpy(newObjv+handlerObjc, objv, sizeof(Tcl_Obj *) * (unsigned)objc);

	/*
	 * Look up and invoke the handler (by recursive call to this
	 * function). If there is no handler at all, instead of doing the
	 * recursive call we just generate a generic error message; it would
	 * be an infinite-recursion nightmare otherwise.
	 */

	cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, newObjv[0]);
	if (cmdPtr == NULL) {
	    Tcl_AppendResult(interp, "invalid command name \"",
		    TclGetString(objv[0]), "\"", NULL);
	    code = TCL_ERROR;
	} else {
	    iPtr->numLevels++;
	    code = TclEvalObjvInternal(interp, newObjc, newObjv, command,
		    length, 0);
	    iPtr->numLevels--;
	}

	/*
	 * Release any resources we locked and allocated during the handler
	 * call.
	 */

	for (i = 0; i < handlerObjc; ++i) {
	    Tcl_DecrRefCount(newObjv[i]);
	}
	TclStackFree(interp, newObjv);
	if (savedNsPtr) {
	    varFramePtr->nsPtr = savedNsPtr;
	}
	goto done;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalObjv --
 *
 *	This function evaluates a Tcl command that has already been parsed
 *	into words, with one Tcl_Obj holding each word.
 *
 * Results:
 *	The return value is a standard Tcl completion code such as TCL_OK or
 *	TCL_ERROR. A result or error message is left in interp's result.
 *
 * Side effects:
 *	Depends on the command.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_EvalObjv(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the
				 * command. Also used for error reporting. */
    int objc,			/* Number of words in command. */
    Tcl_Obj *const objv[],	/* An array of pointers to objects that are
				 * the words that make up the command. */
    int flags)			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Only
				 * TCL_EVAL_GLOBAL and TCL_EVAL_INVOKE are
				 * currently supported. */
{
    Interp *iPtr = (Interp *) interp;
    int code = TCL_OK;
    int allowExceptions = (iPtr->evalFlags & TCL_ALLOW_EXCEPTIONS);

    iPtr->numLevels++;
    code = TclEvalObjvInternal(interp, objc, objv, NULL, 0, flags);
    iPtr->numLevels--;

    if (code == TCL_OK) {
	return code;
    } else {

	/*
	 * If we are again at the top level, process any unusual return code
	 * returned by the evaluated code.
	 */

	if (iPtr->numLevels == 0) {
	    if (code == TCL_RETURN) {
		code = TclUpdateReturnInfo(iPtr);
	    }
	    if ((code != TCL_ERROR) && !allowExceptions) {
		ProcessUnexpectedResult(interp, code);
		code = TCL_ERROR;
	    }
	}

	if ((code == TCL_ERROR) && !(flags & TCL_EVAL_INVOKE)) {
	    /*
	     * If there was an error, a command string will be needed for the
	     * error log: generate it now. Do not worry too much about doing
	     * it expensively.
	     */

	    Tcl_Obj *listPtr;
	    char *cmdString;
	    int cmdLen;

	    listPtr = Tcl_NewListObj(objc, objv);
	    cmdString = Tcl_GetStringFromObj(listPtr, &cmdLen);
	    Tcl_LogCommandInfo(interp, cmdString, cmdString, cmdLen);
	    Tcl_DecrRefCount(listPtr);
	}

	return code;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalTokensStandard --
 *
 *	Given an array of tokens parsed from a Tcl command (e.g., the tokens
 *	that make up a word or the index for an array variable) this function
 *	evaluates the tokens and concatenates their values to form a single
 *	result value.
 *
 * Results:
 *	The return value is a standard Tcl completion code such as TCL_OK or
 *	TCL_ERROR. A result or error message is left in interp's result.
 *
 * Side effects:
 *	Depends on the array of tokens being evaled.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_EvalTokensStandard(
    Tcl_Interp *interp,		/* Interpreter in which to lookup variables,
				 * execute nested commands, and report
				 * errors. */
    Tcl_Token *tokenPtr,	/* Pointer to first in an array of tokens to
				 * evaluate and concatenate. */
    int count)			/* Number of tokens to consider at tokenPtr.
				 * Must be at least 1. */
{
    return TclSubstTokens(interp, tokenPtr, count, /* numLeftPtr */ NULL, 1,
			  NULL, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalTokens --
 *
 *	Given an array of tokens parsed from a Tcl command (e.g., the tokens
 *	that make up a word or the index for an array variable) this function
 *	evaluates the tokens and concatenates their values to form a single
 *	result value.
 *
 * Results:
 *	The return value is a pointer to a newly allocated Tcl_Obj containing
 *	the value of the array of tokens. The reference count of the returned
 *	object has been incremented. If an error occurs in evaluating the
 *	tokens then a NULL value is returned and an error message is left in
 *	interp's result.
 *
 * Side effects:
 *	A new object is allocated to hold the result.
 *
 *----------------------------------------------------------------------
 *
 * This uses a non-standard return convention; its use is now deprecated. It
 * is a wrapper for the new function Tcl_EvalTokensStandard, and is not used
 * in the core any longer. It is only kept for backward compatibility.
 */

Tcl_Obj *
Tcl_EvalTokens(
    Tcl_Interp *interp,		/* Interpreter in which to lookup variables,
				 * execute nested commands, and report
				 * errors. */
    Tcl_Token *tokenPtr,	/* Pointer to first in an array of tokens to
				 * evaluate and concatenate. */
    int count)			/* Number of tokens to consider at tokenPtr.
				 * Must be at least 1. */
{
    Tcl_Obj *resPtr;

    if (Tcl_EvalTokensStandard(interp, tokenPtr, count) != TCL_OK) {
	return NULL;
    }
    resPtr = Tcl_GetObjResult(interp);
    Tcl_IncrRefCount(resPtr);
    Tcl_ResetResult(interp);
    return resPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalEx, TclEvalEx --
 *
 *	This function evaluates a Tcl script without using the compiler or
 *	byte-code interpreter. It just parses the script, creates values for
 *	each word of each command, then calls EvalObjv to execute each
 *	command.
 *
 * Results:
 *	The return value is a standard Tcl completion code such as TCL_OK or
 *	TCL_ERROR. A result or error message is left in interp's result.
 *
 * Side effects:
 *	Depends on the script.
 *
 * TIP #280 : Keep public API, internally extended API.
 *----------------------------------------------------------------------
 */

int
Tcl_EvalEx(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the
				 * script. Also used for error reporting. */
    const char *script,		/* First character of script to evaluate. */
    int numBytes,		/* Number of bytes in script. If < 0, the
				 * script consists of all bytes up to the
				 * first null character. */
    int flags)			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Only
				 * TCL_EVAL_GLOBAL is currently supported. */
{
  return TclEvalEx(interp, script, numBytes, flags, 1, NULL, script);
}

int
TclEvalEx(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate the
				 * script. Also used for error reporting. */
    const char *script,		/* First character of script to evaluate. */
    int numBytes,		/* Number of bytes in script. If < 0, the
				 * script consists of all bytes up to the
				 * first NUL character. */
    int flags,			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Only
				 * TCL_EVAL_GLOBAL is currently supported. */
    int line,			/* The line the script starts on. */
    int*  clNextOuter,       /* Information about an outer context for */
    CONST char* outerScript) /* continuation line data. This is set only in
			      * EvalTokensStandard(), to properly handle
			      * [...]-nested commands. The 'outerScript'
			      * refers to the most-outer script containing the
			      * embedded command, which is refered to by
			      * 'script'. The 'clNextOuter' refers to the
			      * current entry in the table of continuation
			      * lines in this "master script", and the
			      * character offsets are relative to the
			      * 'outerScript' as well.
			      *
			      * If outerScript == script, then this call is
			      * for the outer-most script/command. See
			      * Tcl_EvalEx() and TclEvalObjEx() for places
			      * generating arguments for which this is true.
			      */
{
    Interp *iPtr = (Interp *) interp;
    const char *p, *next;
    const unsigned int minObjs = 20;
    Tcl_Obj **objv, **objvSpace;
    int *expand, *lines, *lineSpace;
    Tcl_Token *tokenPtr;
    int commandLength, bytesLeft, expandRequested, code = TCL_OK;
    CallFrame *savedVarFramePtr;/* Saves old copy of iPtr->varFramePtr in case
				 * TCL_EVAL_GLOBAL was set. */
    int allowExceptions = (iPtr->evalFlags & TCL_ALLOW_EXCEPTIONS);
    int gotParse = 0;
    unsigned int i, objectsUsed = 0;
				/* These variables keep track of how much
				 * state has been allocated while evaluating
				 * the script, so that it can be freed
				 * properly if an error occurs. */
    Tcl_Parse *parsePtr = (Tcl_Parse *)
	    TclStackAlloc(interp, sizeof(Tcl_Parse));
    CmdFrame *eeFramePtr = (CmdFrame *)
	    TclStackAlloc(interp, sizeof(CmdFrame));
    Tcl_Obj **stackObjArray = (Tcl_Obj **)
	    TclStackAlloc(interp, minObjs * sizeof(Tcl_Obj *));
    int *expandStack = (int *) TclStackAlloc(interp, minObjs * sizeof(int));
    int *linesStack = (int *) TclStackAlloc(interp, minObjs * sizeof(int));
				/* TIP #280 Structures for tracking of command
				 * locations. */
    /*
     * Pointer for the tracking of invisible continuation lines. Initialized
     * only if the caller gave us a table of locations to track, via
     * scriptCLLocPtr. It always refers to the table entry holding the
     * location of the next invisible continuation line to look for, while
     * parsing the script.
     */

    int* clNext = NULL;

    if (iPtr->scriptCLLocPtr) {
	if (clNextOuter) {
	    clNext = clNextOuter;
	} else {
	    clNext = &iPtr->scriptCLLocPtr->loc[0];
	}
    }

    if (numBytes < 0) {
	numBytes = strlen(script);
    }
    Tcl_ResetResult(interp);

    savedVarFramePtr = iPtr->varFramePtr;
    if (flags & TCL_EVAL_GLOBAL) {
	iPtr->varFramePtr = iPtr->rootFramePtr;
    }

    /*
     * Each iteration through the following loop parses the next command from
     * the script and then executes it.
     */

    objv = objvSpace = stackObjArray;
    lines = lineSpace = linesStack;
    expand = expandStack;
    p = script;
    bytesLeft = numBytes;

    /*
     * TIP #280 Initialize tracking. Do not push on the frame stack yet.
     *
     * We may continue counting based on a specific context (CTX), or open a
     * new context, either for a sourced script, or 'eval'. For sourced files
     * we always have a path object, even if nothing was specified in the
     * interp itself. That makes code using it simpler as NULL checks can be
     * left out. Sourced file without path in the 'scriptFile' is possible
     * during Tcl initialization.
     */

    if (iPtr->evalFlags & TCL_EVAL_CTX) {
	/*
	 * Path information comes out of the context.
	 */

	eeFramePtr->type = TCL_LOCATION_SOURCE;
	eeFramePtr->data.eval.path = iPtr->invokeCmdFramePtr->data.eval.path;
	Tcl_IncrRefCount(eeFramePtr->data.eval.path);
    } else if (iPtr->evalFlags & TCL_EVAL_FILE) {
	/*
	 * Set up for a sourced file.
	 */

	eeFramePtr->type = TCL_LOCATION_SOURCE;

	if (iPtr->scriptFile) {
	    /*
	     * Normalization here, to have the correct pwd. Should have
	     * negligible impact on performance, as the norm should have been
	     * done already by the 'source' invoking us, and it caches the
	     * result.
	     */

	    Tcl_Obj *norm = Tcl_FSGetNormalizedPath(interp, iPtr->scriptFile);

	    if (norm == NULL) {
		/*
		 * Error message in the interp result.
		 */
		code = TCL_ERROR;
		goto error;
	    }
	    eeFramePtr->data.eval.path = norm;
	} else {
	    TclNewLiteralStringObj(eeFramePtr->data.eval.path, "");
	}
	Tcl_IncrRefCount(eeFramePtr->data.eval.path);
    } else {
	/*
	 * Set up for plain eval.
	 */

	eeFramePtr->type = TCL_LOCATION_EVAL;
	eeFramePtr->data.eval.path = NULL;
    }

    eeFramePtr->level = iPtr->cmdFramePtr ? iPtr->cmdFramePtr->level + 1 : 1;
    eeFramePtr->framePtr = iPtr->framePtr;
    eeFramePtr->nextPtr = iPtr->cmdFramePtr;
    eeFramePtr->nline = 0;
    eeFramePtr->line = NULL;

    iPtr->evalFlags = 0;
    do {
	if (Tcl_ParseCommand(interp, p, bytesLeft, 0, parsePtr) != TCL_OK) {
	    code = TCL_ERROR;
	    goto error;
	}

	/*
	 * TIP #280 Track lines. The parser may have skipped text till it
	 * found the command we are now at. We have to count the lines in this
	 * block, and do not forget invisible continuation lines.
	 */

	TclAdvanceLines(&line, p, parsePtr->commandStart);
	TclAdvanceContinuations (&line, &clNext,
				 parsePtr->commandStart - outerScript);

	gotParse = 1;
	if (parsePtr->numWords > 0) {
	    /*
	     * TIP #280. Track lines within the words of the current
	     * command. We use a separate pointer into the table of
	     * continuation line locations to not lose our position for the
	     * per-command parsing.
	     */

	    int wordLine  = line;
	    const char *wordStart = parsePtr->commandStart;
	    int*        wordCLNext = clNext;

	    /*
	     * Generate an array of objects for the words of the command.
	     */

	    unsigned int objectsNeeded = 0;
	    unsigned int numWords = parsePtr->numWords;

	    if (numWords > minObjs) {
		expand = (int *) ckalloc(numWords * sizeof(int));
		objvSpace = (Tcl_Obj **)
			ckalloc(numWords * sizeof(Tcl_Obj *));
		lineSpace = (int *) ckalloc(numWords * sizeof(int));
	    }
	    expandRequested = 0;
	    objv = objvSpace;
	    lines = lineSpace;

	    for (objectsUsed = 0, tokenPtr = parsePtr->tokenPtr;
		    objectsUsed < numWords;
		    objectsUsed++, tokenPtr += tokenPtr->numComponents+1) {
		/*
		 * TIP #280. Track lines to current word. Save the information
		 * on a per-word basis, signaling dynamic words as needed.
		 * Make the information available to the recursively called
		 * evaluator as well, including the type of context (source
		 * vs. eval).
		 */

		TclAdvanceLines(&wordLine, wordStart, tokenPtr->start);
		TclAdvanceContinuations (&wordLine, &wordCLNext,
					 tokenPtr->start - outerScript);
		wordStart = tokenPtr->start;

		lines[objectsUsed] = TclWordKnownAtCompileTime(tokenPtr, NULL)
			? wordLine : -1;

		if (eeFramePtr->type == TCL_LOCATION_SOURCE) {
		    iPtr->evalFlags |= TCL_EVAL_FILE;
		}

		code = TclSubstTokens(interp, tokenPtr+1,
			tokenPtr->numComponents, NULL, wordLine,
		        wordCLNext, outerScript);

		iPtr->evalFlags = 0;

		if (code != TCL_OK) {
		    goto error;
		}
		objv[objectsUsed] = Tcl_GetObjResult(interp);
		Tcl_IncrRefCount(objv[objectsUsed]);
		if (tokenPtr->type == TCL_TOKEN_EXPAND_WORD) {
		    int numElements;

		    code = TclListObjLength(interp, objv[objectsUsed],
			    &numElements);
		    if (code == TCL_ERROR) {
			/*
			 * Attempt to expand a non-list.
			 */

			Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
				"\n    (expanding word %d)", objectsUsed));
			Tcl_DecrRefCount(objv[objectsUsed]);
			goto error;
		    }
		    expandRequested = 1;
		    expand[objectsUsed] = 1;

		    objectsNeeded += (numElements ? numElements : 1);
		} else {
		    expand[objectsUsed] = 0;
		    objectsNeeded++;
		}

		if (wordCLNext) {
		    TclContinuationsEnterDerived (objv[objectsUsed],
				  wordStart - outerScript, wordCLNext);
		}
	    } /* for loop */
	    if (expandRequested) {
		/*
		 * Some word expansion was requested. Check for objv resize.
		 */

		Tcl_Obj **copy = objvSpace;
		int *lcopy = lineSpace;
		int wordIdx = numWords;
		int objIdx = objectsNeeded - 1;

		if ((numWords > minObjs) || (objectsNeeded >  minObjs)) {
		    objv = objvSpace = (Tcl_Obj **)
			    ckalloc(objectsNeeded * sizeof(Tcl_Obj *));
		    lines = lineSpace = (int *)
			    ckalloc(objectsNeeded * sizeof(int));
		}

		objectsUsed = 0;
		while (wordIdx--) {
		    if (expand[wordIdx]) {
			int numElements;
			Tcl_Obj **elements, *temp = copy[wordIdx];

			Tcl_ListObjGetElements(NULL, temp, &numElements,
				&elements);
			objectsUsed += numElements;
			while (numElements--) {
			    lines[objIdx] = -1;
			    objv[objIdx--] = elements[numElements];
			    Tcl_IncrRefCount(elements[numElements]);
			}
			Tcl_DecrRefCount(temp);
		    } else {
			lines[objIdx] = lcopy[wordIdx];
			objv[objIdx--] = copy[wordIdx];
			objectsUsed++;
		    }
		}
		objv += objIdx+1;

		if (copy != stackObjArray) {
		    ckfree((char *) copy);
		}
		if (lcopy != linesStack) {
		    ckfree((char *) lcopy);
		}
	    }

	    /*
	     * Execute the command and free the objects for its words.
	     *
	     * TIP #280: Remember the command itself for 'info frame'. We
	     * shorten the visible command by one char to exclude the
	     * termination character, if necessary. Here is where we put our
	     * frame on the stack of frames too. _After_ the nested commands
	     * have been executed.
	     */

	    eeFramePtr->cmd.str.cmd = parsePtr->commandStart;
	    eeFramePtr->cmd.str.len = parsePtr->commandSize;

	    if (parsePtr->term ==
		    parsePtr->commandStart + parsePtr->commandSize - 1) {
		eeFramePtr->cmd.str.len--;
	    }

	    eeFramePtr->nline = objectsUsed;
	    eeFramePtr->line = lines;

	    TclArgumentEnter (interp, objv, objectsUsed, eeFramePtr);
	    iPtr->cmdFramePtr = eeFramePtr;
	    iPtr->numLevels++;
	    code = TclEvalObjvInternal(interp, objectsUsed, objv,
		    parsePtr->commandStart, parsePtr->commandSize, 0);
	    iPtr->numLevels--;
	    iPtr->cmdFramePtr = iPtr->cmdFramePtr->nextPtr;
	    TclArgumentRelease (interp, objv, objectsUsed);

	    eeFramePtr->line = NULL;
	    eeFramePtr->nline = 0;

	    if (code != TCL_OK) {
		goto error;
	    }
	    for (i = 0; i < objectsUsed; i++) {
		Tcl_DecrRefCount(objv[i]);
	    }
	    objectsUsed = 0;
	    if (objvSpace != stackObjArray) {
		ckfree((char *) objvSpace);
		objvSpace = stackObjArray;
		ckfree((char *) lineSpace);
		lineSpace = linesStack;
	    }

	    /*
	     * Free expand separately since objvSpace could have been
	     * reallocated above.
	     */

	    if (expand != expandStack) {
		ckfree((char *) expand);
		expand = expandStack;
	    }
	}

	/*
	 * Advance to the next command in the script.
	 *
	 * TIP #280 Track Lines. Now we track how many lines were in the
	 * executed command.
	 */

	next = parsePtr->commandStart + parsePtr->commandSize;
	bytesLeft -= next - p;
	p = next;
	TclAdvanceLines(&line, parsePtr->commandStart, p);
	Tcl_FreeParse(parsePtr);
	gotParse = 0;
    } while (bytesLeft > 0);
    iPtr->varFramePtr = savedVarFramePtr;
    code = TCL_OK;
    goto cleanup_return;

  error:
    /*
     * Generate and log various pieces of error information.
     */

    if (iPtr->numLevels == 0) {
	if (code == TCL_RETURN) {
	    code = TclUpdateReturnInfo(iPtr);
	}
	if ((code != TCL_OK) && (code != TCL_ERROR) && !allowExceptions) {
	    ProcessUnexpectedResult(interp, code);
	    code = TCL_ERROR;
	}
    }
    if ((code == TCL_ERROR) && !(iPtr->flags & ERR_ALREADY_LOGGED)) {
	commandLength = parsePtr->commandSize;
	if (parsePtr->term == parsePtr->commandStart + commandLength - 1) {
	    /*
	     * The terminator character (such as ; or ]) of the command where
	     * the error occurred is the last character in the parsed command.
	     * Reduce the length by one so that the error message doesn't
	     * include the terminator character.
	     */

	    commandLength -= 1;
	}
	Tcl_LogCommandInfo(interp, script, parsePtr->commandStart,
		commandLength);
    }
    iPtr->flags &= ~ERR_ALREADY_LOGGED;

    /*
     * Then free resources that had been allocated to the command.
     */

    for (i = 0; i < objectsUsed; i++) {
	Tcl_DecrRefCount(objv[i]);
    }
    if (gotParse) {
	Tcl_FreeParse(parsePtr);
    }
    if (objvSpace != stackObjArray) {
	ckfree((char *) objvSpace);
	ckfree((char *) lineSpace);
    }
    if (expand != expandStack) {
	ckfree((char *) expand);
    }
    iPtr->varFramePtr = savedVarFramePtr;

 cleanup_return:
    /*
     * TIP #280. Release the local CmdFrame, and its contents.
     */

    if (eeFramePtr->type == TCL_LOCATION_SOURCE) {
	Tcl_DecrRefCount(eeFramePtr->data.eval.path);
    }
    TclStackFree(interp, linesStack);
    TclStackFree(interp, expandStack);
    TclStackFree(interp, stackObjArray);
    TclStackFree(interp, eeFramePtr);
    TclStackFree(interp, parsePtr);

    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * TclAdvanceLines --
 *
 *	This function is a helper which counts the number of lines in a block
 *	of text and advances an external counter.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The specified counter is advanced per the number of lines found.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclAdvanceLines(
    int *line,
    const char *start,
    const char *end)
{
    register const char *p;

    for (p = start; p < end; p++) {
	if (*p == '\n') {
	    (*line)++;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclAdvanceContinuations --
 *
 *	This procedure is a helper which counts the number of continuation
 *	lines (CL) in a block of text using a table of CL locations and
 *	advances an external counter, and the pointer into the table.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The specified counter is advanced per the number of continuation lines
 *	found.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclAdvanceContinuations (line,clNextPtrPtr,loc)
     int* line;
     int** clNextPtrPtr;
     int loc;
{
    /*
     * Track the invisible continuation lines embedded in a script, if
     * any. Here they are just spaces (already). They were removed by
     * EvalTokensStandard() via Tcl_UtfBackslash().
     *
     * *clNextPtrPtr         <=> We have continuation lines to track.
     * **clNextPtrPtr >= 0   <=> We are not beyond the last possible location.
     * loc >= **clNextPtrPtr <=> We stepped beyond the current cont. line.
     */

    while (*clNextPtrPtr && (**clNextPtrPtr >= 0) && (loc >= **clNextPtrPtr)) {
	/*
	 * We just stepped over an invisible continuation line. Adjust the
	 * line counter and step to the table entry holding the location of
	 * the next continuation line to track.
	 */
	(*line) ++;
	(*clNextPtrPtr) ++;
    }
}

/*
 *----------------------------------------------------------------------
 * Note: The whole data structure access for argument location tracking is
 * hidden behind these three functions. The only parts open are the lineLAPtr
 * field in the Interp structure. The CFWord definition is internal to here.
 * Should make it easier to redo the data structures if we find something more
 * space/time efficient.
 */

/*
 *----------------------------------------------------------------------
 *
 * TclArgumentEnter --
 *
 *	This procedure is a helper for the TIP #280 uplevel extension.
 *	It enters location references for the arguments of a command to be
 *	invoked. Only the first entry has the actual data, further entries
 *	simply count the usage up.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May allocate memory.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclArgumentEnter(interp,objv,objc,cfPtr)
     Tcl_Interp* interp;
     Tcl_Obj**   objv;
     int         objc;
     CmdFrame*   cfPtr;
{
    Interp* iPtr = (Interp*) interp;
    int new, i;
    Tcl_HashEntry* hPtr;
    CFWord* cfwPtr;

    for (i=1; i < objc; i++) {
	/*
	 * Ignore argument words without line information (= dynamic).  If
	 * they are variables they may have location information associated
	 * with that, either through globally recorded 'set' invokations, or
	 * literals in bytecode. Eitehr way there is no need to record
	 * something here.
	 */

	if (cfPtr->line [i] < 0) continue;
	hPtr = Tcl_CreateHashEntry (iPtr->lineLAPtr, (char*) objv[i], &new);
	if (new) {
           /*
	    * The word is not on the stack yet, remember the current location
	    * and initialize references.
            */
           cfwPtr = (CFWord*) ckalloc (sizeof (CFWord));
           cfwPtr->framePtr = cfPtr;
           cfwPtr->word     = i;
           cfwPtr->refCount = 1;
           Tcl_SetHashValue (hPtr, cfwPtr);
	} else {
           /*
	    * The word is already on the stack, its current location is not
            * relevant. Just remember the reference to prevent early removal.
            */
           cfwPtr = (CFWord*) Tcl_GetHashValue (hPtr);
           cfwPtr->refCount ++;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclArgumentRelease --
 *
 *	This procedure is a helper for the TIP #280 uplevel extension.
 *	It removes the location references for the arguments of a command
 *	just done. Usage is counted down, the data is removed only when
 *	no user is left over.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May release memory.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclArgumentRelease(interp,objv,objc)
     Tcl_Interp* interp;
     Tcl_Obj**   objv;
     int         objc;
{
    Interp*        iPtr = (Interp*) interp;
    Tcl_HashEntry* hPtr;
    CFWord*        cfwPtr;
    int i;

    for (i=1; i < objc; i++) {
       hPtr = Tcl_FindHashEntry (iPtr->lineLAPtr, (char *) objv[i]);

       if (!hPtr) { continue; }
       cfwPtr = (CFWord*) Tcl_GetHashValue (hPtr);

       cfwPtr->refCount --;
       if (cfwPtr->refCount > 0) { continue; }

       ckfree ((char*) cfwPtr);
       Tcl_DeleteHashEntry (hPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclArgumentBCEnter --
 *
 *	This procedure is a helper for the TIP #280 uplevel extension.
 *	It enters location references for the literal arguments of commands
 *	in bytecode about to be invoked. Only the first entry has the actual
 *	data, further entries simply count the usage up.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May allocate memory.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclArgumentBCEnter(interp,objv,objc,codePtr,cfPtr,pc)
     Tcl_Interp* interp;
     Tcl_Obj*    objv[];
     int         objc;
     void*       codePtr;
     CmdFrame*   cfPtr;
     int         pc;
{
    Interp*        iPtr  = (Interp*) interp;
    Tcl_HashEntry* hePtr = Tcl_FindHashEntry (iPtr->lineBCPtr, (char *) codePtr);

    if (hePtr) {
	ExtCmdLoc* eclPtr = (ExtCmdLoc*) Tcl_GetHashValue (hePtr);
	hePtr = Tcl_FindHashEntry(&eclPtr->litInfo, INT2PTR(pc));

	if (hePtr) {
	    int  cmd  = PTR2INT(Tcl_GetHashValue(hePtr));
	    ECL* ePtr = &eclPtr->loc[cmd];
	    int word;

	    /*
	     * A few truths ...
	     * (1) ePtr->nline == objc
	     * (2) (ePtr->line[word] < 0) => !literal, for all words
	     * (3) (word == 0) => !literal
	     *
	     * Item (2) is why we can use objv to get the literals, and do not
	     * have to save them at compile time.
	     */

	    for (word = 1; word < objc; word++) {
		if (ePtr->line[word] >= 0) {
		    int isnew;
		    Tcl_HashEntry* hPtr =
			Tcl_CreateHashEntry (iPtr->lineLABCPtr,
					     (char*) objv[word], &isnew);
		    CFWordBC* cfwPtr = (CFWordBC*) ckalloc (sizeof (CFWordBC));

		    cfwPtr->framePtr = cfPtr;
		    cfwPtr->pc       = pc;
		    cfwPtr->word     = word;

		    if (isnew) {
			/*
			 * The word is not on the stack yet, remember the
			 * current location and initialize references.
			 */
			cfwPtr->prevPtr = NULL;
		    } else {
			/*
			 * The object is already on the stack, however it may
			 * have a different location now (literal sharing may
			 * map multiple location to a single Tcl_Obj*. Save
			 * the old information in the new structure.
			 */
			cfwPtr->prevPtr = (CFWordBC*) Tcl_GetHashValue(hPtr);
		    }

		    Tcl_SetHashValue (hPtr, cfwPtr);
		}
	    } /* for */
	} /* if */
    } /* if */
}

/*
 *----------------------------------------------------------------------
 *
 * TclArgumentBCRelease --
 *
 *	This procedure is a helper for the TIP #280 uplevel extension.
 *	It removes the location references for the literal arguments of
 *	commands in bytecode just done. Usage is counted down, the data
 *	is removed only when no user is left over.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May release memory.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclArgumentBCRelease(interp,objv,objc,codePtr,pc)
     Tcl_Interp* interp;
     Tcl_Obj*    objv[];
     int         objc;
     void*       codePtr;
     int         pc;
{
    Interp*        iPtr  = (Interp*) interp;
    Tcl_HashEntry* hePtr = Tcl_FindHashEntry (iPtr->lineBCPtr, (char *) codePtr);

    if (hePtr) {
	ExtCmdLoc* eclPtr = (ExtCmdLoc*) Tcl_GetHashValue (hePtr);
	hePtr = Tcl_FindHashEntry(&eclPtr->litInfo, INT2PTR(pc));

	if (hePtr) {
	    int  cmd  = PTR2INT(Tcl_GetHashValue(hePtr));
	    ECL* ePtr = &eclPtr->loc[cmd];
	    int word;

	    /*
	     * Iterate in reverse order, to properly match our pop to the push
	     * in TclArgumentBCEnter().
	     */
	    for (word = objc-1; word >= 1; word--) {
		if (ePtr->line[word] >= 0) {
		    Tcl_HashEntry* hPtr = Tcl_FindHashEntry(iPtr->lineLABCPtr,
						    (char *) objv[word]);
		    if (hPtr) {
			CFWordBC* cfwPtr = (CFWordBC*) Tcl_GetHashValue (hPtr);
 
			if (cfwPtr->prevPtr) {
			    Tcl_SetHashValue(hPtr, cfwPtr->prevPtr);
			} else {
			    Tcl_DeleteHashEntry(hPtr);
			}

			ckfree((char *) cfwPtr);
		    }
		}
	    }
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclArgumentGet --
 *
 *	This procedure is a helper for the TIP #280 uplevel extension.
 *	It find the location references for a Tcl_Obj, if any.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Writes found location information into the result arguments.
 *
 * TIP #280
 *----------------------------------------------------------------------
 */

void
TclArgumentGet(interp,obj,cfPtrPtr,wordPtr)
     Tcl_Interp* interp;
     Tcl_Obj*    obj;
     CmdFrame**  cfPtrPtr;
     int*        wordPtr;
{
    Interp*        iPtr = (Interp*) interp;
    Tcl_HashEntry* hPtr;
    CmdFrame*      framePtr;

    /*
     * An object which either has no string rep or else is a canonical list is
     * guaranteed to have been generated dynamically: bail out, this cannot
     * have a usable absolute location. _Do not touch_ the information the set
     * up by the caller. It knows better than us.
     */

    if ((!obj->bytes) || ((obj->typePtr == &tclListType) &&
	    ((List *)obj->internalRep.twoPtrValue.ptr1)->canonicalFlag)) {
	return;
    }

    /*
     * First look for location information recorded in the argument
     * stack. That is nearest.
     */

    hPtr = Tcl_FindHashEntry (iPtr->lineLAPtr, (char *) obj);
    if (hPtr) {
	CFWord* cfwPtr = (CFWord*) Tcl_GetHashValue (hPtr);
	*wordPtr  = cfwPtr->word;
	*cfPtrPtr = cfwPtr->framePtr;
	return;
    }

    /*
     * Check if the Tcl_Obj has location information as a bytecode literal, in
     * that stack.
     */

    hPtr = Tcl_FindHashEntry (iPtr->lineLABCPtr, (char *) obj);

    if (hPtr) {
	CFWordBC* cfwPtr = (CFWordBC*) Tcl_GetHashValue (hPtr);

	framePtr = cfwPtr->framePtr;
	framePtr->data.tebc.pc = (char *) (((ByteCode*)
		framePtr->data.tebc.codePtr)->codeStart + cfwPtr->pc);
	*cfPtrPtr = cfwPtr->framePtr;
	*wordPtr  = cfwPtr->word;
	return;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Eval --
 *
 *	Execute a Tcl command in a string. This function executes the script
 *	directly, rather than compiling it to bytecodes. Before the arrival of
 *	the bytecode compiler in Tcl 8.0 Tcl_Eval was the main function used
 *	for executing Tcl commands, but nowadays it isn't used much.
 *
 * Results:
 *	The return value is one of the return codes defined in tcl.h (such as
 *	TCL_OK), and interp's result contains a value to supplement the return
 *	code. The value of the result will persist only until the next call to
 *	Tcl_Eval or Tcl_EvalObj: you must copy it or lose it!
 *
 * Side effects:
 *	Can be almost arbitrary, depending on the commands in the script.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_Eval(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * previous call to Tcl_CreateInterp). */
    const char *script)		/* Pointer to TCL command to execute. */
{
    int code = Tcl_EvalEx(interp, script, -1, 0);

    /*
     * For backwards compatibility with old C code that predates the object
     * system in Tcl 8.0, we have to mirror the object result back into the
     * string result (some callers may expect it there).
     */

    (void) Tcl_GetStringResult(interp);
    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalObj, Tcl_GlobalEvalObj --
 *
 *	These functions are deprecated but we keep them around for backwards
 *	compatibility reasons.
 *
 * Results:
 *	See the functions they call.
 *
 * Side effects:
 *	See the functions they call.
 *
 *----------------------------------------------------------------------
 */

#undef Tcl_EvalObj
int
Tcl_EvalObj(
    Tcl_Interp *interp,
    Tcl_Obj *objPtr)
{
    return Tcl_EvalObjEx(interp, objPtr, 0);
}

#undef Tcl_GlobalEvalObj
int
Tcl_GlobalEvalObj(
    Tcl_Interp *interp,
    Tcl_Obj *objPtr)
{
    return Tcl_EvalObjEx(interp, objPtr, TCL_EVAL_GLOBAL);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_EvalObjEx, TclEvalObjEx --
 *
 *	Execute Tcl commands stored in a Tcl object. These commands are
 *	compiled into bytecodes if necessary, unless TCL_EVAL_DIRECT is
 *	specified.
 *
 * Results:
 *	The return value is one of the return codes defined in tcl.h (such as
 *	TCL_OK), and the interpreter's result contains a value to supplement
 *	the return code.
 *
 * Side effects:
 *	The object is converted, if necessary, to a ByteCode object that holds
 *	the bytecode instructions for the commands. Executing the commands
 *	will almost certainly have side effects that depend on those commands.
 *
 * TIP #280 : Keep public API, internally extended API.
 *----------------------------------------------------------------------
 */

int
Tcl_EvalObjEx(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * a previous call to Tcl_CreateInterp). */
    register Tcl_Obj *objPtr,	/* Pointer to object containing commands to
				 * execute. */
    int flags)			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Supported values
				 * are TCL_EVAL_GLOBAL and TCL_EVAL_DIRECT. */
{
    return TclEvalObjEx(interp, objPtr, flags, NULL, 0);
}

int
TclEvalObjEx(
    Tcl_Interp *interp,		/* Token for command interpreter (returned by
				 * a previous call to Tcl_CreateInterp). */
    register Tcl_Obj *objPtr,	/* Pointer to object containing commands to
				 * execute. */
    int flags,			/* Collection of OR-ed bits that control the
				 * evaluation of the script. Supported values
				 * are TCL_EVAL_GLOBAL and TCL_EVAL_DIRECT. */
    const CmdFrame *invoker,	/* Frame of the command doing the eval. */
    int word)			/* Index of the word which is in objPtr. */
{
    register Interp *iPtr = (Interp *) interp;
    char *script;
    int numSrcBytes;
    int result;
    CallFrame *savedVarFramePtr;/* Saves old copy of iPtr->varFramePtr in case
				 * TCL_EVAL_GLOBAL was set. */

    Tcl_IncrRefCount(objPtr);

    /* Pure List Optimization (no string representation). In this case, we can
     * safely use Tcl_EvalObjv instead and get an appreciable improvement in
     * execution speed. This is because it allows us to avoid a setFromAny
     * step that would just pack everything into a string and back out again.
     *
     * This also preserves any associations between list elements and location
     * information for such elements.
     *
     * This restriction has been relaxed a bit by storing in lists whether
     * they are "canonical" or not (a canonical list being one that is either
     * pure or that has its string rep derived by UpdateStringOfList from the
     * internal rep).
     */

    if (objPtr->typePtr == &tclListType) {	/* is a list... */
	List *listRepPtr = objPtr->internalRep.twoPtrValue.ptr1;

	if (objPtr->bytes == NULL ||	/* ...without a string rep */
	    listRepPtr->canonicalFlag) {/* ...or that is canonical */
	    /*
	     * TIP #280 Structures for tracking lines. As we know that this is
	     * dynamic execution we ignore the invoker, even if known.
	     */

	    int nelements;
	    Tcl_Obj **elements, *copyPtr = TclListObjCopy(NULL, objPtr);
	    CmdFrame *eoFramePtr = (CmdFrame *)
		TclStackAlloc(interp, sizeof(CmdFrame));

	    eoFramePtr->type = TCL_LOCATION_EVAL_LIST;
	    eoFramePtr->level = (iPtr->cmdFramePtr == NULL?
				 1 : iPtr->cmdFramePtr->level + 1);
	    eoFramePtr->framePtr = iPtr->framePtr;
	    eoFramePtr->nextPtr = iPtr->cmdFramePtr;

	    eoFramePtr->nline = 0;
	    eoFramePtr->line = NULL;

	    eoFramePtr->cmd.listPtr  = objPtr;
	    Tcl_IncrRefCount(eoFramePtr->cmd.listPtr);
	    eoFramePtr->data.eval.path = NULL;

	    /*
	     * TIP #280 We do _not_ compute all the line numbers for the words
	     * in the command. For the eval of a pure list the most sensible
	     * choice is to put all words on line 1. Given that we neither
	     * need memory for them nor compute anything.  'line' is left
	     * NULL. The two places using this information (TclInfoFrame, and
	     * TclInitCompileEnv), are special-cased to use the proper line
	     * number directly instead of accessing the 'line' array.
	     */

	    Tcl_ListObjGetElements(NULL, copyPtr,
				   &nelements, &elements);

	    iPtr->cmdFramePtr = eoFramePtr;
	    result = Tcl_EvalObjv(interp, nelements, elements,
				  flags);

	    Tcl_DecrRefCount(copyPtr);
	    iPtr->cmdFramePtr = iPtr->cmdFramePtr->nextPtr;
	    Tcl_DecrRefCount(eoFramePtr->cmd.listPtr);
	    TclStackFree(interp, eoFramePtr);

	    goto done;
	}
    }

    if (flags & TCL_EVAL_DIRECT) {
	/*
	 * We're not supposed to use the compiler or byte-code interpreter.
	 * Let Tcl_EvalEx evaluate the command directly (and probably more
	 * slowly).
	 */

	/*
	 * TIP #280. Propagate context as much as we can. Especially if the
	 * script to evaluate is a single literal it makes sense to look if
	 * our context is one with absolute line numbers we can then track
	 * into the literal itself too.
	 *
	 * See also tclCompile.c, TclInitCompileEnv, for the equivalent code
	 * in the bytecode compiler.
	 */

	/*
	 * Now we check if we have data about invisible continuation lines for
	 * the script, and make it available to the direct script parser and
	 * evaluator we are about to call, if so.
	 *
	 * It may be possible that the script Tcl_Obj* can be free'd while the
	 * evaluator is using it, leading to the release of the associated
	 * ContLineLoc structure as well. To ensure that the latter doesn't
	 * happen we set a lock on it. We release this lock later in this
	 * function, after the evaluator is done.  The relevant "lineCLPtr"
	 * hashtable is managed in the file "tclObj.c".
	 *
	 * Another important action is to save (and later restore) the
	 * continuation line information of the caller, in case we are
	 * executing nested commands in the eval/direct path.
	 */

	ContLineLoc* saveCLLocPtr = iPtr->scriptCLLocPtr;
	ContLineLoc* clLocPtr = TclContinuationsGet (objPtr);

	if (clLocPtr) {
	    iPtr->scriptCLLocPtr = clLocPtr;
	    Tcl_Preserve (iPtr->scriptCLLocPtr);
	} else {
	    iPtr->scriptCLLocPtr = NULL;
	}

	if (invoker == NULL) {
	    /*
	     * No context, force opening of our own.
	     */

	    script = Tcl_GetStringFromObj(objPtr, &numSrcBytes);
	    result = Tcl_EvalEx(interp, script, numSrcBytes, flags);
	} else {
	    /*
	     * We have an invoker, describing the command asking for the
	     * evaluation of a subordinate script. This script may originate
	     * in a literal word, or from a variable, etc. Using the line
	     * array we now check if we have good line information for the
	     * relevant word. The type of context is relevant as well. In a
	     * non-'source' context we don't have to try tracking lines.
	     *
	     * First see if the word exists and is a literal. If not we go
	     * through the easy dynamic branch. No need to perform more
	     * complex invokations.
	     */

	    int pc = 0;
	    CmdFrame *ctxPtr = (CmdFrame *)
		TclStackAlloc(interp, sizeof(CmdFrame));

	    *ctxPtr = *invoker;
	    if (invoker->type == TCL_LOCATION_BC) {
		/*
		 * Note: Type BC => ctxPtr->data.eval.path is not used.
		 * ctxPtr->data.tebc.codePtr is used instead.
		 */

		TclGetSrcInfoForPc(ctxPtr);
		pc = 1;
	    }

	    script = Tcl_GetStringFromObj(objPtr, &numSrcBytes);

	    if ((ctxPtr->nline <= word) ||
		(ctxPtr->line[word] < 0) ||
		(ctxPtr->type != TCL_LOCATION_SOURCE)) {
		/*
		 * Dynamic script, or dynamic context, force our own
		 * context.
		 */

		result = Tcl_EvalEx(interp, script, numSrcBytes, flags);

	    } else {
		/*
		 * Absolute context to reuse.
		 */

		iPtr->invokeCmdFramePtr = ctxPtr;
		iPtr->evalFlags |= TCL_EVAL_CTX;

		result = TclEvalEx(interp, script, numSrcBytes, flags,
				   ctxPtr->line[word], NULL, script);
	    }

	    if (pc && (ctxPtr->type == TCL_LOCATION_SOURCE)) {
		/*
		 * Death of SrcInfo reference.
		 */

		Tcl_DecrRefCount(ctxPtr->data.eval.path);
	    }
	    TclStackFree(interp, ctxPtr);
	}

	/*
	 * Now release the lock on the continuation line information, if
	 * any, and restore the caller's settings.
	 */

	if (iPtr->scriptCLLocPtr) {
	    Tcl_Release (iPtr->scriptCLLocPtr);
	}
	iPtr->scriptCLLocPtr = saveCLLocPtr;
    } else {
	/*
	 * Let the compiler/engine subsystem do the evaluation.
	 *
	 * TIP #280 The invoker provides us with the context for the script.
	 * We transfer this to the byte code compiler.
	 */
	int allowExceptions = (iPtr->evalFlags & TCL_ALLOW_EXCEPTIONS);

	savedVarFramePtr = iPtr->varFramePtr;
	if (flags & TCL_EVAL_GLOBAL) {
	    iPtr->varFramePtr = iPtr->rootFramePtr;
	}

	result = TclCompEvalObj(interp, objPtr, invoker, word);

	/*
	 * If we are again at the top level, process any unusual return code
	 * returned by the evaluated code.
	 */

	if (iPtr->numLevels == 0) {
	    if (result == TCL_RETURN) {
		result = TclUpdateReturnInfo(iPtr);
	    }
	    if ((result != TCL_OK) && (result != TCL_ERROR)
		    && !allowExceptions) {
		ProcessUnexpectedResult(interp, result);
		result = TCL_ERROR;
		script = Tcl_GetStringFromObj(objPtr, &numSrcBytes);
		Tcl_LogCommandInfo(interp, script, script, numSrcBytes);
	    }
	}
	iPtr->evalFlags = 0;
	iPtr->varFramePtr = savedVarFramePtr;
    }

  done:
    TclDecrRefCount(objPtr);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * ProcessUnexpectedResult --
 *
 *	Function called by Tcl_EvalObj to set the interpreter's result value
 *	to an appropriate error message when the code it evaluates returns an
 *	unexpected result code (not TCL_OK and not TCL_ERROR) to the topmost
 *	evaluation level.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The interpreter result is set to an error message appropriate to the
 *	result code.
 *
 *----------------------------------------------------------------------
 */

static void
ProcessUnexpectedResult(
    Tcl_Interp *interp,		/* The interpreter in which the unexpected
				 * result code was returned. */
    int returnCode)		/* The unexpected result code. */
{
    Tcl_ResetResult(interp);
    if (returnCode == TCL_BREAK) {
	Tcl_AppendResult(interp,
		"invoked \"break\" outside of a loop", NULL);
    } else if (returnCode == TCL_CONTINUE) {
	Tcl_AppendResult(interp,
		"invoked \"continue\" outside of a loop", NULL);
    } else {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"command returned bad code: %d", returnCode));
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_ExprLong, Tcl_ExprDouble, Tcl_ExprBoolean --
 *
 *	Functions to evaluate an expression and return its value in a
 *	particular form.
 *
 * Results:
 *	Each of the functions below returns a standard Tcl result. If an error
 *	occurs then an error message is left in the interp's result. Otherwise
 *	the value of the expression, in the appropriate form, is stored at
 *	*ptr. If the expression had a result that was incompatible with the
 *	desired form then an error is returned.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_ExprLong(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    const char *exprstring,	/* Expression to evaluate. */
    long *ptr)			/* Where to store result. */
{
    register Tcl_Obj *exprPtr;
    int result = TCL_OK;
    if (*exprstring == '\0') {
	/*
	 * Legacy compatibility - return 0 for the zero-length string.
	 */

	*ptr = 0;
    } else {
	exprPtr = Tcl_NewStringObj(exprstring, -1);
	Tcl_IncrRefCount(exprPtr);
	result = Tcl_ExprLongObj(interp, exprPtr, ptr);
	Tcl_DecrRefCount(exprPtr);
	if (result != TCL_OK) {
	    (void) Tcl_GetStringResult(interp);
	}
    }
    return result;
}

int
Tcl_ExprDouble(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    const char *exprstring,	/* Expression to evaluate. */
    double *ptr)		/* Where to store result. */
{
    register Tcl_Obj *exprPtr;
    int result = TCL_OK;

    if (*exprstring == '\0') {
	/*
	 * Legacy compatibility - return 0 for the zero-length string.
	 */

	*ptr = 0.0;
    } else {
	exprPtr = Tcl_NewStringObj(exprstring, -1);
	Tcl_IncrRefCount(exprPtr);
	result = Tcl_ExprDoubleObj(interp, exprPtr, ptr);
	Tcl_DecrRefCount(exprPtr);
				/* Discard the expression object. */
	if (result != TCL_OK) {
	    (void) Tcl_GetStringResult(interp);
	}
    }
    return result;
}

int
Tcl_ExprBoolean(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    const char *exprstring,	/* Expression to evaluate. */
    int *ptr)			/* Where to store 0/1 result. */
{
    if (*exprstring == '\0') {
	/*
	 * An empty string. Just set the result boolean to 0 (false).
	 */

	*ptr = 0;
	return TCL_OK;
    } else {
	int result;
	Tcl_Obj *exprPtr = Tcl_NewStringObj(exprstring, -1);

	Tcl_IncrRefCount(exprPtr);
	result = Tcl_ExprBooleanObj(interp, exprPtr, ptr);
	Tcl_DecrRefCount(exprPtr);
	if (result != TCL_OK) {
	    /*
	     * Move the interpreter's object result to the string result, then
	     * reset the object result.
	     */

	    (void) Tcl_GetStringResult(interp);
	}
	return result;
    }
}

/*
 *--------------------------------------------------------------
 *
 * Tcl_ExprLongObj, Tcl_ExprDoubleObj, Tcl_ExprBooleanObj --
 *
 *	Functions to evaluate an expression in an object and return its value
 *	in a particular form.
 *
 * Results:
 *	Each of the functions below returns a standard Tcl result object. If
 *	an error occurs then an error message is left in the interpreter's
 *	result. Otherwise the value of the expression, in the appropriate
 *	form, is stored at *ptr. If the expression had a result that was
 *	incompatible with the desired form then an error is returned.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

int
Tcl_ExprLongObj(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    register Tcl_Obj *objPtr,	/* Expression to evaluate. */
    long *ptr)			/* Where to store long result. */
{
    Tcl_Obj *resultPtr;
    int result, type;
    double d;
    ClientData internalPtr;

    result = Tcl_ExprObj(interp, objPtr, &resultPtr);
    if (result != TCL_OK) {
	return TCL_ERROR;
    }

    if (TclGetNumberFromObj(interp, resultPtr, &internalPtr, &type) != TCL_OK){
	return TCL_ERROR;
    }

    switch (type) {
    case TCL_NUMBER_DOUBLE: {
	mp_int big;

	d = *((const double *) internalPtr);
	Tcl_DecrRefCount(resultPtr);
	if (Tcl_InitBignumFromDouble(interp, d, &big) != TCL_OK) {
	    return TCL_ERROR;
	}
	resultPtr = Tcl_NewBignumObj(&big);
	/* FALLTHROUGH */
    }
    case TCL_NUMBER_LONG:
    case TCL_NUMBER_WIDE:
    case TCL_NUMBER_BIG:
	result = TclGetLongFromObj(interp, resultPtr, ptr);
	break;

    case TCL_NUMBER_NAN:
	Tcl_GetDoubleFromObj(interp, resultPtr, &d);
	result = TCL_ERROR;
    }

    Tcl_DecrRefCount(resultPtr);/* Discard the result object. */
    return result;
}

int
Tcl_ExprDoubleObj(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    register Tcl_Obj *objPtr,	/* Expression to evaluate. */
    double *ptr)		/* Where to store double result. */
{
    Tcl_Obj *resultPtr;
    int result, type;
    ClientData internalPtr;

    result = Tcl_ExprObj(interp, objPtr, &resultPtr);
    if (result != TCL_OK) {
	return TCL_ERROR;
    }

    result = TclGetNumberFromObj(interp, resultPtr, &internalPtr, &type);
    if (result == TCL_OK) {
	switch (type) {
	case TCL_NUMBER_NAN:
#ifndef ACCEPT_NAN
	    result = Tcl_GetDoubleFromObj(interp, resultPtr, ptr);
	    break;
#endif
	case TCL_NUMBER_DOUBLE:
	    *ptr = *((const double *) internalPtr);
	    result = TCL_OK;
	    break;
	default:
	    result = Tcl_GetDoubleFromObj(interp, resultPtr, ptr);
	}
    }
    Tcl_DecrRefCount(resultPtr);/* Discard the result object. */
    return result;
}

int
Tcl_ExprBooleanObj(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    register Tcl_Obj *objPtr,	/* Expression to evaluate. */
    int *ptr)			/* Where to store 0/1 result. */
{
    Tcl_Obj *resultPtr;
    int result;

    result = Tcl_ExprObj(interp, objPtr, &resultPtr);
    if (result == TCL_OK) {
	result = Tcl_GetBooleanFromObj(interp, resultPtr, ptr);
	Tcl_DecrRefCount(resultPtr);
				/* Discard the result object. */
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclObjInvokeNamespace --
 *
 *	Object version: Invokes a Tcl command, given an objv/objc, from either
 *	the exposed or hidden set of commands in the given interpreter.
 *	NOTE: The command is invoked in the global stack frame of the
 *	interpreter or namespace, thus it cannot see any current state on the
 *	stack of that interpreter.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	Whatever the command does.
 *
 *----------------------------------------------------------------------
 */

int
TclObjInvokeNamespace(
    Tcl_Interp *interp,		/* Interpreter in which command is to be
				 * invoked. */
    int objc,			/* Count of arguments. */
    Tcl_Obj *const objv[],	/* Argument objects; objv[0] points to the
				 * name of the command to invoke. */
    Tcl_Namespace *nsPtr,	/* The namespace to use. */
    int flags)			/* Combination of flags controlling the call:
				 * TCL_INVOKE_HIDDEN, TCL_INVOKE_NO_UNKNOWN,
				 * or TCL_INVOKE_NO_TRACEBACK. */
{
    int result;
    Tcl_CallFrame *framePtr;

    /*
     * Make the specified namespace the current namespace and invoke the
     * command.
     */

    result = TclPushStackFrame(interp, &framePtr, nsPtr, /*isProcFrame*/0);
    if (result != TCL_OK) {
	return TCL_ERROR;
    }

    result = TclObjInvoke(interp, objc, objv, flags);

    TclPopStackFrame(interp);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclObjInvoke --
 *
 *	Invokes a Tcl command, given an objv/objc, from either the exposed or
 *	the hidden sets of commands in the given interpreter.
 *
 * Results:
 *	A standard Tcl object result.
 *
 * Side effects:
 *	Whatever the command does.
 *
 *----------------------------------------------------------------------
 */

int
TclObjInvoke(
    Tcl_Interp *interp,		/* Interpreter in which command is to be
				 * invoked. */
    int objc,			/* Count of arguments. */
    Tcl_Obj *const objv[],	/* Argument objects; objv[0] points to the
				 * name of the command to invoke. */
    int flags)			/* Combination of flags controlling the call:
				 * TCL_INVOKE_HIDDEN, TCL_INVOKE_NO_UNKNOWN,
				 * or TCL_INVOKE_NO_TRACEBACK. */
{
    register Interp *iPtr = (Interp *) interp;
    Tcl_HashTable *hTblPtr;	/* Table of hidden commands. */
    char *cmdName;		/* Name of the command from objv[0]. */
    Tcl_HashEntry *hPtr = NULL;
    Command *cmdPtr;
    int result;

    if (interp == NULL) {
	return TCL_ERROR;
    }

    if ((objc < 1) || (objv == NULL)) {
	Tcl_AppendResult(interp, "illegal argument vector", NULL);
	return TCL_ERROR;
    }

    if ((flags & TCL_INVOKE_HIDDEN) == 0) {
	Tcl_Panic("TclObjInvoke: called without TCL_INVOKE_HIDDEN");
    }

    if (TclInterpReady(interp) == TCL_ERROR) {
	return TCL_ERROR;
    }

    cmdName = TclGetString(objv[0]);
    hTblPtr = iPtr->hiddenCmdTablePtr;
    if (hTblPtr != NULL) {
	hPtr = Tcl_FindHashEntry(hTblPtr, cmdName);
    }
    if (hPtr == NULL) {
	Tcl_AppendResult(interp, "invalid hidden command name \"",
		cmdName, "\"", NULL);
	return TCL_ERROR;
    }
    cmdPtr = Tcl_GetHashValue(hPtr);

    /*
     * Invoke the command function.
     */

    iPtr->cmdCount++;
    result = cmdPtr->objProc(cmdPtr->objClientData, interp, objc, objv);

    /*
     * If an error occurred, record information about what was being executed
     * when the error occurred.
     */

    if ((result == TCL_ERROR)
	    && ((flags & TCL_INVOKE_NO_TRACEBACK) == 0)
	    && ((iPtr->flags & ERR_ALREADY_LOGGED) == 0)) {
	int length;
	Tcl_Obj *command = Tcl_NewListObj(objc, objv);
	const char *cmdString;

	Tcl_IncrRefCount(command);
	cmdString = Tcl_GetStringFromObj(command, &length);
	Tcl_LogCommandInfo(interp, cmdString, cmdString, length);
	Tcl_DecrRefCount(command);
	iPtr->flags &= ~ERR_ALREADY_LOGGED;
    }
    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_ExprString --
 *
 *	Evaluate an expression in a string and return its value in string
 *	form.
 *
 * Results:
 *	A standard Tcl result. If the result is TCL_OK, then the interp's
 *	result is set to the string value of the expression. If the result is
 *	TCL_ERROR, then the interp's result contains an error message.
 *
 * Side effects:
 *	A Tcl object is allocated to hold a copy of the expression string.
 *	This expression object is passed to Tcl_ExprObj and then deallocated.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_ExprString(
    Tcl_Interp *interp,		/* Context in which to evaluate the
				 * expression. */
    const char *expr)		/* Expression to evaluate. */
{
    int code = TCL_OK;

    if (expr[0] == '\0') {
	/*
	 * An empty string. Just set the interpreter's result to 0.
	 */

	Tcl_SetResult(interp, "0", TCL_VOLATILE);
    } else {
	Tcl_Obj *resultPtr, *exprObj = Tcl_NewStringObj(expr, -1);

	Tcl_IncrRefCount(exprObj);
	code = Tcl_ExprObj(interp, exprObj, &resultPtr);
	Tcl_DecrRefCount(exprObj);
	if (code == TCL_OK) {
	    Tcl_SetObjResult(interp, resultPtr);
	    Tcl_DecrRefCount(resultPtr);
	}

	/*
	 * Force the string rep of the interp result.
	 */

	(void) Tcl_GetStringResult(interp);
    }
    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AppendObjToErrorInfo --
 *
 *	Add a Tcl_Obj value to the errorInfo field that describes the current
 *	error.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The value of the Tcl_obj is appended to the errorInfo field. If we are
 *	just starting to log an error, errorInfo is initialized from the error
 *	message in the interpreter's result.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AppendObjToErrorInfo(
    Tcl_Interp *interp,		/* Interpreter to which error information
				 * pertains. */
    Tcl_Obj *objPtr)		/* Message to record. */
{
    int length;
    const char *message = TclGetStringFromObj(objPtr, &length);

    Tcl_IncrRefCount(objPtr);
    Tcl_AddObjErrorInfo(interp, message, length);
    Tcl_DecrRefCount(objPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AddErrorInfo --
 *
 *	Add information to the errorInfo field that describes the current
 *	error.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The contents of message are appended to the errorInfo field. If we are
 *	just starting to log an error, errorInfo is initialized from the error
 *	message in the interpreter's result.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AddErrorInfo(
    Tcl_Interp *interp,		/* Interpreter to which error information
				 * pertains. */
    const char *message)	/* Message to record. */
{
    Tcl_AddObjErrorInfo(interp, message, -1);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AddObjErrorInfo --
 *
 *	Add information to the errorInfo field that describes the current
 *	error. This routine differs from Tcl_AddErrorInfo by taking a byte
 *	pointer and length.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	"length" bytes from "message" are appended to the errorInfo field. If
 *	"length" is negative, use bytes up to the first NULL byte. If we are
 *	just starting to log an error, errorInfo is initialized from the error
 *	message in the interpreter's result.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AddObjErrorInfo(
    Tcl_Interp *interp,		/* Interpreter to which error information
				 * pertains. */
    const char *message,	/* Points to the first byte of an array of
				 * bytes of the message. */
    int length)			/* The number of bytes in the message. If < 0,
				 * then append all bytes up to a NULL byte. */
{
    register Interp *iPtr = (Interp *) interp;

    /*
     * If we are just starting to log an error, errorInfo is initialized from
     * the error message in the interpreter's result.
     */

    iPtr->flags |= ERR_LEGACY_COPY;
    if (iPtr->errorInfo == NULL) {
	if (iPtr->result[0] != 0) {
	    /*
	     * The interp's string result is set, apparently by some extension
	     * making a deprecated direct write to it. That extension may
	     * expect interp->result to continue to be set, so we'll take
	     * special pains to avoid clearing it, until we drop support for
	     * interp->result completely.
	     */

	    iPtr->errorInfo = Tcl_NewStringObj(interp->result, -1);
	} else {
	    iPtr->errorInfo = iPtr->objResultPtr;
	}
	Tcl_IncrRefCount(iPtr->errorInfo);
	if (!iPtr->errorCode) {
	    Tcl_SetErrorCode(interp, "NONE", NULL);
	}
    }

    /*
     * Now append "message" to the end of errorInfo.
     */

    if (length != 0) {
	if (Tcl_IsShared(iPtr->errorInfo)) {
	    Tcl_DecrRefCount(iPtr->errorInfo);
	    iPtr->errorInfo = Tcl_DuplicateObj(iPtr->errorInfo);
	    Tcl_IncrRefCount(iPtr->errorInfo);
	}
	Tcl_AppendToObj(iPtr->errorInfo, message, length);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_VarEvalVA --
 *
 *	Given a variable number of string arguments, concatenate them all
 *	together and execute the result as a Tcl command.
 *
 * Results:
 *	A standard Tcl return result. An error message or other result may be
 *	left in the interp's result.
 *
 * Side effects:
 *	Depends on what was done by the command.
 *
 *---------------------------------------------------------------------------
 */

int
Tcl_VarEvalVA(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate command. */
    va_list argList)		/* Variable argument list. */
{
    Tcl_DString buf;
    char *string;
    int result;

    /*
     * Copy the strings one after the other into a single larger string. Use
     * stack-allocated space for small commands, but if the command gets too
     * large than call ckalloc to create the space.
     */

    Tcl_DStringInit(&buf);
    while (1) {
	string = va_arg(argList, char *);
	if (string == NULL) {
	    break;
	}
	Tcl_DStringAppend(&buf, string, -1);
    }

    result = Tcl_Eval(interp, Tcl_DStringValue(&buf));
    Tcl_DStringFree(&buf);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_VarEval --
 *
 *	Given a variable number of string arguments, concatenate them all
 *	together and execute the result as a Tcl command.
 *
 * Results:
 *	A standard Tcl return result. An error message or other result may be
 *	left in interp->result.
 *
 * Side effects:
 *	Depends on what was done by the command.
 *
 *----------------------------------------------------------------------
 */
	/* ARGSUSED */
int
Tcl_VarEval(
    Tcl_Interp *interp,
    ...)
{
    va_list argList;
    int result;

    va_start(argList, interp);
    result = Tcl_VarEvalVA(interp, argList);
    va_end(argList);

    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GlobalEval --
 *
 *	Evaluate a command at global level in an interpreter.
 *
 * Results:
 *	A standard Tcl result is returned, and the interp's result is modified
 *	accordingly.
 *
 * Side effects:
 *	The command string is executed in interp, and the execution is carried
 *	out in the variable context of global level (no functions active),
 *	just as if an "uplevel #0" command were being executed.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GlobalEval(
    Tcl_Interp *interp,		/* Interpreter in which to evaluate command. */
    const char *command)	/* Command to evaluate. */
{
    register Interp *iPtr = (Interp *) interp;
    int result;
    CallFrame *savedVarFramePtr;

    savedVarFramePtr = iPtr->varFramePtr;
    iPtr->varFramePtr = iPtr->rootFramePtr;
    result = Tcl_Eval(interp, command);
    iPtr->varFramePtr = savedVarFramePtr;
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetRecursionLimit --
 *
 *	Set the maximum number of recursive calls that may be active for an
 *	interpreter at once.
 *
 * Results:
 *	The return value is the old limit on nesting for interp.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetRecursionLimit(
    Tcl_Interp *interp,		/* Interpreter whose nesting limit is to be
				 * set. */
    int depth)			/* New value for maximimum depth. */
{
    Interp *iPtr = (Interp *) interp;
    int old;

    old = iPtr->maxNestingDepth;
    if (depth > 0) {
	iPtr->maxNestingDepth = depth;
    }
    return old;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AllowExceptions --
 *
 *	Sets a flag in an interpreter so that exceptions can occur in the next
 *	call to Tcl_Eval without them being turned into errors.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The TCL_ALLOW_EXCEPTIONS flag gets set in the interpreter's evalFlags
 *	structure. See the reference documentation for more details.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AllowExceptions(
    Tcl_Interp *interp)		/* Interpreter in which to set flag. */
{
    Interp *iPtr = (Interp *) interp;

    iPtr->evalFlags |= TCL_ALLOW_EXCEPTIONS;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetVersion --
 *
 *	Get the Tcl major, minor, and patchlevel version numbers and the
 *	release type. A patch is a release type TCL_FINAL_RELEASE with a
 *	patchLevel > 0.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_GetVersion(
    int *majorV,
    int *minorV,
    int *patchLevelV,
    int *type)
{
    if (majorV != NULL) {
	*majorV = TCL_MAJOR_VERSION;
    }
    if (minorV != NULL) {
	*minorV = TCL_MINOR_VERSION;
    }
    if (patchLevelV != NULL) {
	*patchLevelV = TCL_RELEASE_SERIAL;
    }
    if (type != NULL) {
	*type = TCL_RELEASE_LEVEL;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Math Functions --
 *
 *	This page contains the functions that implement all of the built-in
 *	math functions for expressions.
 *
 * Results:
 *	Each function returns TCL_OK if it succeeds and pushes an Tcl object
 *	holding the result. If it fails it returns TCL_ERROR and leaves an
 *	error message in the interpreter's result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
ExprCeilFunc(
    ClientData clientData,	/* Ignored */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter list. */
{
    int code;
    double d;
    mp_int big;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[1], &d);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[1]->typePtr == &tclDoubleType)) {
	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    if (Tcl_GetBignumFromObj(NULL, objv[1], &big) == TCL_OK) {
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(TclCeil(&big)));
	mp_clear(&big);
    } else {
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(ceil(d)));
    }
    return TCL_OK;
}

static int
ExprFloorFunc(
    ClientData clientData,	/* Ignored */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter list. */
{
    int code;
    double d;
    mp_int big;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[1], &d);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[1]->typePtr == &tclDoubleType)) {
	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    if (Tcl_GetBignumFromObj(NULL, objv[1], &big) == TCL_OK) {
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(TclFloor(&big)));
	mp_clear(&big);
    } else {
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(floor(d)));
    }
    return TCL_OK;
}

static int
ExprIsqrtFunc(
    ClientData clientData,	/* Ignored */
    Tcl_Interp *interp,		/* The interpreter in which to execute. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter list. */
{
    ClientData ptr;
    int type;
    double d;
    Tcl_WideInt w;
    mp_int big;
    int exact = 0;		/* Flag == 1 if the argument can be
				 * represented in a double as an exact
				 * integer. */

    /*
     * Check syntax.
     */

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }

    /*
     * Make sure that the arg is a number.
     */

    if (TclGetNumberFromObj(interp, objv[1], &ptr, &type) != TCL_OK) {
	return TCL_ERROR;
    }

    switch (type) {
    case TCL_NUMBER_NAN:
	Tcl_GetDoubleFromObj(interp, objv[1], &d);
	return TCL_ERROR;
    case TCL_NUMBER_DOUBLE:
	d = *((const double *) ptr);
	if (d < 0) {
	    goto negarg;
	}
#ifdef IEEE_FLOATING_POINT
	if (d <= MAX_EXACT) {
	    exact = 1;
	}
#endif
	if (!exact) {
	    if (Tcl_InitBignumFromDouble(interp, d, &big) != TCL_OK) {
		return TCL_ERROR;
	    }
	}
	break;
    case TCL_NUMBER_BIG:
	if (Tcl_GetBignumFromObj(interp, objv[1], &big) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (SIGN(&big) == MP_NEG) {
	    mp_clear(&big);
	    goto negarg;
	}
	break;
    default:
	if (Tcl_GetWideIntFromObj(interp, objv[1], &w) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (w < 0) {
	    goto negarg;
	}
	d = (double) w;
#ifdef IEEE_FLOATING_POINT
	if (d < MAX_EXACT) {
	    exact = 1;
	}
#endif
	if (!exact) {
	    Tcl_GetBignumFromObj(interp, objv[1], &big);
	}
	break;
    }

    if (exact) {
	Tcl_SetObjResult(interp, Tcl_NewWideIntObj((Tcl_WideInt) sqrt(d)));
    } else {
	mp_int root;

	mp_init(&root);
	mp_sqrt(&big, &root);
	mp_clear(&big);
	Tcl_SetObjResult(interp, Tcl_NewBignumObj(&root));
    }

    return TCL_OK;

  negarg:
    Tcl_SetObjResult(interp,
	    Tcl_NewStringObj("square root of negative argument", -1));
    return TCL_ERROR;
}

static int
ExprSqrtFunc(
    ClientData clientData,	/* Ignored */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter list. */
{
    int code;
    double d;
    mp_int big;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[1], &d);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[1]->typePtr == &tclDoubleType)) {
	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    if ((d >= 0.0) && TclIsInfinite(d)
	    && (Tcl_GetBignumFromObj(NULL, objv[1], &big) == TCL_OK)) {
	mp_int root;

	mp_init(&root);
	mp_sqrt(&big, &root);
	mp_clear(&big);
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(TclBignumToDouble(&root)));
	mp_clear(&root);
    } else {
	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(sqrt(d)));
    }
    return TCL_OK;
}

static int
ExprUnaryFunc(
    ClientData clientData,	/* Contains the address of a function that
				 * takes one double argument and returns a
				 * double result. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count */
    Tcl_Obj *const *objv)	/* Actual parameter list */
{
    int code;
    double d;
    double (*func)(double) = (double (*)(double)) clientData;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[1], &d);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[1]->typePtr == &tclDoubleType)) {
	d = objv[1]->internalRep.doubleValue;
	Tcl_ResetResult(interp);
	code = TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    errno = 0;
    return CheckDoubleResult(interp, (*func)(d));
}

static int
CheckDoubleResult(
    Tcl_Interp *interp,
    double dResult)
{
#ifndef ACCEPT_NAN
    if (TclIsNaN(dResult)) {
	TclExprFloatError(interp, dResult);
	return TCL_ERROR;
    }
#endif
    if ((errno == ERANGE) && ((dResult == 0.0) || TclIsInfinite(dResult))) {
	/*
	 * When ERANGE signals under/overflow, just accept 0.0 or +/-Inf
	 */
    } else if (errno != 0) {
	/*
	 * Report other errno values as errors.
	 */

	TclExprFloatError(interp, dResult);
	return TCL_ERROR;
    }
    Tcl_SetObjResult(interp, Tcl_NewDoubleObj(dResult));
    return TCL_OK;
}

static int
ExprBinaryFunc(
    ClientData clientData,	/* Contains the address of a function that
				 * takes two double arguments and returns a
				 * double result. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Parameter vector. */
{
    int code;
    double d1, d2;
    double (*func)(double, double) = (double (*)(double, double)) clientData;

    if (objc != 3) {
	MathFuncWrongNumArgs(interp, 3, objc, objv);
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[1], &d1);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[1]->typePtr == &tclDoubleType)) {
	d1 = objv[1]->internalRep.doubleValue;
	Tcl_ResetResult(interp);
	code = TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    code = Tcl_GetDoubleFromObj(interp, objv[2], &d2);
#ifdef ACCEPT_NAN
    if ((code != TCL_OK) && (objv[2]->typePtr == &tclDoubleType)) {
	d2 = objv[2]->internalRep.doubleValue;
	Tcl_ResetResult(interp);
	code = TCL_OK;
    }
#endif
    if (code != TCL_OK) {
	return TCL_ERROR;
    }
    errno = 0;
    return CheckDoubleResult(interp, (*func)(d1, d2));
}

static int
ExprAbsFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Parameter vector. */
{
    ClientData ptr;
    int type;
    mp_int big;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }

    if (TclGetNumberFromObj(interp, objv[1], &ptr, &type) != TCL_OK) {
	return TCL_ERROR;
    }

    if (type == TCL_NUMBER_LONG) {
	long l = *((const long *) ptr);
	if (l <= (long)0) {
	    if (l == LONG_MIN) {
		TclBNInitBignumFromLong(&big, l);
		goto tooLarge;
	    }
	    Tcl_SetObjResult(interp, Tcl_NewLongObj(-l));
	} else {
	    Tcl_SetObjResult(interp, objv[1]);
	}
	return TCL_OK;
    }

    if (type == TCL_NUMBER_DOUBLE) {
	double d = *((const double *) ptr);
	if (d <= 0.0) {
	    Tcl_SetObjResult(interp, Tcl_NewDoubleObj(-d));
	} else {
	    Tcl_SetObjResult(interp, objv[1]);
	}
	return TCL_OK;
    }

#ifndef NO_WIDE_TYPE
    if (type == TCL_NUMBER_WIDE) {
	Tcl_WideInt w = *((const Tcl_WideInt *) ptr);
	if (w < (Tcl_WideInt)0) {
	    if (w == LLONG_MIN) {
		TclBNInitBignumFromWideInt(&big, w);
		goto tooLarge;
	    }
	    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(-w));
	} else {
	    Tcl_SetObjResult(interp, objv[1]);
	}
	return TCL_OK;
    }
#endif

    if (type == TCL_NUMBER_BIG) {
	/* TODO: const correctness ? */
	if (mp_cmp_d((mp_int *) ptr, 0) == MP_LT) {
	    Tcl_GetBignumFromObj(NULL, objv[1], &big);
	tooLarge:
	    mp_neg(&big, &big);
	    Tcl_SetObjResult(interp, Tcl_NewBignumObj(&big));
	} else {
	    Tcl_SetObjResult(interp, objv[1]);
	}
	return TCL_OK;
    }

    if (type == TCL_NUMBER_NAN) {
#ifdef ACCEPT_NAN
	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
#else
	double d;
	Tcl_GetDoubleFromObj(interp, objv[1], &d);
	return TCL_ERROR;
#endif
    }
    return TCL_OK;
}

static int
ExprBoolFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    int value;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    if (Tcl_GetBooleanFromObj(interp, objv[1], &value) != TCL_OK) {
	return TCL_ERROR;
    }
    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(value));
    return TCL_OK;
}

static int
ExprDoubleFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    double dResult;
    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    if (Tcl_GetDoubleFromObj(interp, objv[1], &dResult) != TCL_OK) {
#ifdef ACCEPT_NAN
	if (objv[1]->typePtr == &tclDoubleType) {
	    Tcl_SetObjResult(interp, objv[1]);
	    return TCL_OK;
	}
#endif
	return TCL_ERROR;
    }
    Tcl_SetObjResult(interp, Tcl_NewDoubleObj(dResult));
    return TCL_OK;
}

static int
ExprEntierFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    double d;
    int type;
    ClientData ptr;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }
    if (TclGetNumberFromObj(interp, objv[1], &ptr, &type) != TCL_OK) {
	return TCL_ERROR;
    }

    if (type == TCL_NUMBER_DOUBLE) {
	d = *((const double *) ptr);
	if ((d >= (double)LONG_MAX) || (d <= (double)LONG_MIN)) {
	    mp_int big;

	    if (Tcl_InitBignumFromDouble(interp, d, &big) != TCL_OK) {
		/* Infinity */
		return TCL_ERROR;
	    }
	    Tcl_SetObjResult(interp, Tcl_NewBignumObj(&big));
	    return TCL_OK;
	} else {
	    long result = (long) d;

	    Tcl_SetObjResult(interp, Tcl_NewLongObj(result));
	    return TCL_OK;
	}
    }

    if (type != TCL_NUMBER_NAN) {
	/*
	 * All integers are already of integer type.
	 */

	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }

    /*
     * Get the error message for NaN.
     */

    Tcl_GetDoubleFromObj(interp, objv[1], &d);
    return TCL_ERROR;
}

static int
ExprIntFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    long iResult;
    Tcl_Obj *objPtr;
    if (ExprEntierFunc(NULL, interp, objc, objv) != TCL_OK) {
	return TCL_ERROR;
    }
    objPtr = Tcl_GetObjResult(interp);
    if (TclGetLongFromObj(NULL, objPtr, &iResult) != TCL_OK) {
	/*
	 * Truncate the bignum; keep only bits in long range.
	 */

	mp_int big;

	Tcl_GetBignumFromObj(NULL, objPtr, &big);
	mp_mod_2d(&big, (int) CHAR_BIT * sizeof(long), &big);
	objPtr = Tcl_NewBignumObj(&big);
	Tcl_IncrRefCount(objPtr);
	TclGetLongFromObj(NULL, objPtr, &iResult);
	Tcl_DecrRefCount(objPtr);
    }
    Tcl_SetObjResult(interp, Tcl_NewLongObj(iResult));
    return TCL_OK;
}

static int
ExprWideFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    Tcl_WideInt wResult;
    Tcl_Obj *objPtr;
    if (ExprEntierFunc(NULL, interp, objc, objv) != TCL_OK) {
	return TCL_ERROR;
    }
    objPtr = Tcl_GetObjResult(interp);
    if (Tcl_GetWideIntFromObj(NULL, objPtr, &wResult) != TCL_OK) {
	/*
	 * Truncate the bignum; keep only bits in wide int range.
	 */

	mp_int big;

	Tcl_GetBignumFromObj(NULL, objPtr, &big);
	mp_mod_2d(&big, (int) CHAR_BIT * sizeof(Tcl_WideInt), &big);
	objPtr = Tcl_NewBignumObj(&big);
	Tcl_IncrRefCount(objPtr);
	Tcl_GetWideIntFromObj(NULL, objPtr, &wResult);
	Tcl_DecrRefCount(objPtr);
    }
    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(wResult));
    return TCL_OK;
}

static int
ExprRandFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    Interp *iPtr = (Interp *) interp;
    double dResult;
    long tmp;			/* Algorithm assumes at least 32 bits. Only
				 * long guarantees that. See below. */
    Tcl_Obj *oResult;

    if (objc != 1) {
	MathFuncWrongNumArgs(interp, 1, objc, objv);
	return TCL_ERROR;
    }

    if (!(iPtr->flags & RAND_SEED_INITIALIZED)) {
	iPtr->flags |= RAND_SEED_INITIALIZED;

	/*
	 * Take into consideration the thread this interp is running in order
	 * to insure different seeds in different threads (bug #416643)
	 */

	iPtr->randSeed = TclpGetClicks() + ((long)Tcl_GetCurrentThread()<<12);

	/*
	 * Make sure 1 <= randSeed <= (2^31) - 2. See below.
	 */

	iPtr->randSeed &= (unsigned long) 0x7fffffff;
	if ((iPtr->randSeed == 0) || (iPtr->randSeed == 0x7fffffff)) {
	    iPtr->randSeed ^= 123459876;
	}
    }

    /*
     * Generate the random number using the linear congruential generator
     * defined by the following recurrence:
     *		seed = ( IA * seed ) mod IM
     * where IA is 16807 and IM is (2^31) - 1. The recurrence maps a seed in
     * the range [1, IM - 1] to a new seed in that same range. The recurrence
     * maps IM to 0, and maps 0 back to 0, so those two values must not be
     * allowed as initial values of seed.
     *
     * In order to avoid potential problems with integer overflow, the
     * recurrence is implemented in terms of additional constants IQ and IR
     * such that
     *		IM = IA*IQ + IR
     * None of the operations in the implementation overflows a 32-bit signed
     * integer, and the C type long is guaranteed to be at least 32 bits wide.
     *
     * For more details on how this algorithm works, refer to the following
     * papers:
     *
     *	S.K. Park & K.W. Miller, "Random number generators: good ones are hard
     *	to find," Comm ACM 31(10):1192-1201, Oct 1988
     *
     *	W.H. Press & S.A. Teukolsky, "Portable random number generators,"
     *	Computers in Physics 6(5):522-524, Sep/Oct 1992.
     */

#define RAND_IA		16807
#define RAND_IM		2147483647
#define RAND_IQ		127773
#define RAND_IR		2836
#define RAND_MASK	123459876

    tmp = iPtr->randSeed/RAND_IQ;
    iPtr->randSeed = RAND_IA*(iPtr->randSeed - tmp*RAND_IQ) - RAND_IR*tmp;
    if (iPtr->randSeed < 0) {
	iPtr->randSeed += RAND_IM;
    }

    /*
     * Since the recurrence keeps seed values in the range [1, RAND_IM - 1],
     * dividing by RAND_IM yields a double in the range (0, 1).
     */

    dResult = iPtr->randSeed * (1.0/RAND_IM);

    /*
     * Push a Tcl object with the result.
     */

    TclNewDoubleObj(oResult, dResult);
    Tcl_SetObjResult(interp, oResult);
    return TCL_OK;
}

static int
ExprRoundFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Parameter vector. */
{
    double d;
    ClientData ptr;
    int type;

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }

    if (TclGetNumberFromObj(interp, objv[1], &ptr, &type) != TCL_OK) {
	return TCL_ERROR;
    }

    if (type == TCL_NUMBER_DOUBLE) {
	double fractPart, intPart;
	long max = LONG_MAX, min = LONG_MIN;

	fractPart = modf(*((const double *) ptr), &intPart);
	if (fractPart <= -0.5) {
	    min++;
	} else if (fractPart >= 0.5) {
	    max--;
	}
	if ((intPart >= (double)max) || (intPart <= (double)min)) {
	    mp_int big;

	    if (Tcl_InitBignumFromDouble(interp, intPart, &big) != TCL_OK) {
		/* Infinity */
		return TCL_ERROR;
	    }
	    if (fractPart <= -0.5) {
		mp_sub_d(&big, 1, &big);
	    } else if (fractPart >= 0.5) {
		mp_add_d(&big, 1, &big);
	    }
	    Tcl_SetObjResult(interp, Tcl_NewBignumObj(&big));
	    return TCL_OK;
	} else {
	    long result = (long)intPart;

	    if (fractPart <= -0.5) {
		result--;
	    } else if (fractPart >= 0.5) {
		result++;
	    }
	    Tcl_SetObjResult(interp, Tcl_NewLongObj(result));
	    return TCL_OK;
	}
    }

    if (type != TCL_NUMBER_NAN) {
	/*
	 * All integers are already rounded
	 */

	Tcl_SetObjResult(interp, objv[1]);
	return TCL_OK;
    }

    /*
     * Get the error message for NaN.
     */

    Tcl_GetDoubleFromObj(interp, objv[1], &d);
    return TCL_ERROR;
}

static int
ExprSrandFunc(
    ClientData clientData,	/* Ignored. */
    Tcl_Interp *interp,		/* The interpreter in which to execute the
				 * function. */
    int objc,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Parameter vector. */
{
    Interp *iPtr = (Interp *) interp;
    long i = 0;			/* Initialized to avoid compiler warning. */

    /*
     * Convert argument and use it to reset the seed.
     */

    if (objc != 2) {
	MathFuncWrongNumArgs(interp, 2, objc, objv);
	return TCL_ERROR;
    }

    if (TclGetLongFromObj(NULL, objv[1], &i) != TCL_OK) {
	Tcl_Obj *objPtr;
	mp_int big;

	if (Tcl_GetBignumFromObj(interp, objv[1], &big) != TCL_OK) {
	    /* TODO: more ::errorInfo here? or in caller? */
	    return TCL_ERROR;
	}

	mp_mod_2d(&big, (int) CHAR_BIT * sizeof(long), &big);
	objPtr = Tcl_NewBignumObj(&big);
	Tcl_IncrRefCount(objPtr);
	TclGetLongFromObj(NULL, objPtr, &i);
	Tcl_DecrRefCount(objPtr);
    }

    /*
     * Reset the seed. Make sure 1 <= randSeed <= 2^31 - 2. See comments in
     * ExprRandFunc() for more details.
     */

    iPtr->flags |= RAND_SEED_INITIALIZED;
    iPtr->randSeed = i;
    iPtr->randSeed &= (unsigned long) 0x7fffffff;
    if ((iPtr->randSeed == 0) || (iPtr->randSeed == 0x7fffffff)) {
	iPtr->randSeed ^= 123459876;
    }

    /*
     * To avoid duplicating the random number generation code we simply clean
     * up our state and call the real random number function. That function
     * will always succeed.
     */

    return ExprRandFunc(clientData, interp, 1, objv);
}

/*
 *----------------------------------------------------------------------
 *
 * MathFuncWrongNumArgs --
 *
 *	Generate an error message when a math function presents the wrong
 *	number of arguments.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	An error message is stored in the interpreter result.
 *
 *----------------------------------------------------------------------
 */

static void
MathFuncWrongNumArgs(
    Tcl_Interp *interp,		/* Tcl interpreter */
    int expected,		/* Formal parameter count. */
    int found,			/* Actual parameter count. */
    Tcl_Obj *const *objv)	/* Actual parameter vector. */
{
    const char *name = Tcl_GetString(objv[0]);
    const char *tail = name + strlen(name);

    while (tail > name+1) {
	--tail;
	if (*tail == ':' && tail[-1] == ':') {
	    name = tail+1;
	    break;
	}
    }
    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
	    "too %s arguments for math function \"%s\"",
	    (found < expected ? "few" : "many"), name));
}
#ifdef USE_DTRACE

/*
 *----------------------------------------------------------------------
 *
 * DTraceObjCmd --
 *
 *	This function is invoked to process the "::tcl::dtrace" Tcl command.
 *
 * Results:
 *	A standard Tcl object result.
 *
 * Side effects:
 *	The 'tcl-probe' DTrace probe is triggered (if it is enabled).
 *
 *----------------------------------------------------------------------
 */

static int
DTraceObjCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    if (TCL_DTRACE_TCL_PROBE_ENABLED()) {
	char *a[10];
	int i = 0;

	while (i++ < 10) {
	    a[i-1] = i < objc ? TclGetString(objv[i]) : NULL;
	}
	TCL_DTRACE_TCL_PROBE(a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7],
		a[8], a[9]);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclDTraceInfo --
 *
 *	Extract information from a TIP280 dict for use by DTrace probes.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
TclDTraceInfo(
    Tcl_Obj *info,
    char **args,
    int *argsi)
{
    static Tcl_Obj *keys[7] = { NULL };
    Tcl_Obj **k = keys, *val;
    int i;

    if (!*k) {
	TclNewLiteralStringObj(keys[0], "cmd");
	TclNewLiteralStringObj(keys[1], "type");
	TclNewLiteralStringObj(keys[2], "proc");
	TclNewLiteralStringObj(keys[3], "file");
	TclNewLiteralStringObj(keys[4], "lambda");
	TclNewLiteralStringObj(keys[5], "line");
	TclNewLiteralStringObj(keys[6], "level");
    }
    for (i = 0; i < 4; i++) {
	Tcl_DictObjGet(NULL, info, *k++, &val);
	args[i] = val ? TclGetString(val) : NULL;
    }
    if (!args[2]) {
	Tcl_DictObjGet(NULL, info, *k, &val);
	args[2] = val ? TclGetString(val) : NULL;
    }
    k++;
    for (i = 0; i < 2; i++) {
	Tcl_DictObjGet(NULL, info, *k++, &val);
	if (val) {
	    TclGetIntFromObj(NULL, val, &(argsi[i]));
	} else {
	    argsi[i] = 0;
	}
    }
}

TCL_DTRACE_DEBUG_LOG()

#endif /* USE_DTRACE */

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */
