Merge commit '29ccecd87709feda60d191f6aaba324ccad91f55' as 'tcl8.6'

1 files changed, 9086 insertions, 0 deletions

diff --git a/tcl8.6/generic/tclBasic.c b/tcl8.6/generic/tclBasic.c
new file mode 100644
index 0000000..14d67f6
--- /dev/null
+++ b/tcl8.6/generic/tclBasic.c
@@ -0,0 +1,9086 @@
+/*
+ * 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>
+ * Copyright (c) 2006-2008 by Joe Mistachkin.  All rights reserved.
+ * Copyright (c) 2008 Miguel Sofer <msofer@users.sourceforge.net>
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tclInt.h"
+#include "tclOOInt.h"
+#include "tclCompile.h"
+#include "tommath.h"
+#include <math.h>
+#include <assert.h>
+
+#define INTERP_STACK_INITIAL_SIZE 2000
+#define CORO_STACK_INITIAL_SIZE    200
+
+/*
+ * 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;
+
+/*
+ * This is the script cancellation struct and hash table. The hash table is
+ * used to keep track of the information necessary to process script
+ * cancellation requests, including the original interp, asynchronous handler
+ * tokens (created by Tcl_AsyncCreate), and the clientData and flags arguments
+ * passed to Tcl_CancelEval on a per-interp basis. The cancelLock mutex is
+ * used for protecting calls to Tcl_CancelEval as well as protecting access to
+ * the hash table below.
+ */
+
+typedef struct {
+    Tcl_Interp *interp;		/* Interp this struct belongs to. */
+    Tcl_AsyncHandler async;	/* Async handler token for script
+				 * cancellation. */
+    char *result;		/* The script cancellation result or NULL for
+				 * a default result. */
+    int length;			/* Length of the above error message. */
+    ClientData clientData;	/* Ignored */
+    int flags;			/* Additional flags */
+} CancelInfo;
+static Tcl_HashTable cancelTable;
+static int cancelTableInitialized = 0;	/* 0 means not yet initialized. */
+TCL_DECLARE_MUTEX(cancelLock)
+
+/*
+ * Declarations for managing contexts for non-recursive coroutines. Contexts
+ * are used to save the evaluation state between NR calls to each coro.
+ */
+
+#define SAVE_CONTEXT(context)				\
+    (context).framePtr = iPtr->framePtr;		\
+    (context).varFramePtr = iPtr->varFramePtr;		\
+    (context).cmdFramePtr = iPtr->cmdFramePtr;		\
+    (context).lineLABCPtr = iPtr->lineLABCPtr
+
+#define RESTORE_CONTEXT(context)			\
+    iPtr->framePtr = (context).framePtr;		\
+    iPtr->varFramePtr = (context).varFramePtr;		\
+    iPtr->cmdFramePtr = (context).cmdFramePtr;		\
+    iPtr->lineLABCPtr = (context).lineLABCPtr
+
+/*
+ * Static functions in this file:
+ */
+
+static char *		CallCommandTraces(Interp *iPtr, Command *cmdPtr,
+			    const char *oldName, const char *newName,
+			    int flags);
+static int		CancelEvalProc(ClientData clientData,
+			    Tcl_Interp *interp, int code);
+static int		CheckDoubleResult(Tcl_Interp *interp, double dResult);
+static void		DeleteCoroutine(ClientData clientData);
+static void		DeleteInterpProc(Tcl_Interp *interp);
+static void		DeleteOpCmdClientData(ClientData clientData);
+#ifdef USE_DTRACE
+static Tcl_ObjCmdProc	DTraceObjCmd;
+static Tcl_NRPostProc	DTraceCmdReturn;
+#else
+#   define DTraceCmdReturn	NULL
+#endif /* USE_DTRACE */
+static Tcl_ObjCmdProc	ExprAbsFunc;
+static Tcl_ObjCmdProc	ExprBinaryFunc;
+static Tcl_ObjCmdProc	ExprBoolFunc;
+static Tcl_ObjCmdProc	ExprCeilFunc;
+static Tcl_ObjCmdProc	ExprDoubleFunc;
+static Tcl_ObjCmdProc	ExprEntierFunc;
+static Tcl_ObjCmdProc	ExprFloorFunc;
+static Tcl_ObjCmdProc	ExprIntFunc;
+static Tcl_ObjCmdProc	ExprIsqrtFunc;
+static Tcl_ObjCmdProc	ExprRandFunc;
+static Tcl_ObjCmdProc	ExprRoundFunc;
+static Tcl_ObjCmdProc	ExprSqrtFunc;
+static Tcl_ObjCmdProc	ExprSrandFunc;
+static Tcl_ObjCmdProc	ExprUnaryFunc;
+static Tcl_ObjCmdProc	ExprWideFunc;
+static void		MathFuncWrongNumArgs(Tcl_Interp *interp, int expected,
+			    int actual, Tcl_Obj *const *objv);
+static Tcl_NRPostProc	NRCoroutineCallerCallback;
+static Tcl_NRPostProc	NRCoroutineExitCallback;
+static Tcl_NRPostProc	NRCommand;
+
+static Tcl_ObjCmdProc	OldMathFuncProc;
+static void		OldMathFuncDeleteProc(ClientData clientData);
+static void		ProcessUnexpectedResult(Tcl_Interp *interp,
+			    int returnCode);
+static int		RewindCoroutine(CoroutineData *corPtr, int result);
+static void		TEOV_SwitchVarFrame(Tcl_Interp *interp);
+static void		TEOV_PushExceptionHandlers(Tcl_Interp *interp,
+			    int objc, Tcl_Obj *const objv[], int flags);
+static inline Command *	TEOV_LookupCmdFromObj(Tcl_Interp *interp,
+			    Tcl_Obj *namePtr, Namespace *lookupNsPtr);
+static int		TEOV_NotFound(Tcl_Interp *interp, int objc,
+			    Tcl_Obj *const objv[], Namespace *lookupNsPtr);
+static int		TEOV_RunEnterTraces(Tcl_Interp *interp,
+			    Command **cmdPtrPtr, Tcl_Obj *commandPtr, int objc,
+			    Tcl_Obj *const objv[]);
+static Tcl_NRPostProc	RewindCoroutineCallback;
+static Tcl_NRPostProc	TEOEx_ByteCodeCallback;
+static Tcl_NRPostProc	TEOEx_ListCallback;
+static Tcl_NRPostProc	TEOV_Error;
+static Tcl_NRPostProc	TEOV_Exception;
+static Tcl_NRPostProc	TEOV_NotFoundCallback;
+static Tcl_NRPostProc	TEOV_RestoreVarFrame;
+static Tcl_NRPostProc	TEOV_RunLeaveTraces;
+static Tcl_NRPostProc	EvalObjvCore;
+static Tcl_NRPostProc	Dispatch;
+
+static Tcl_ObjCmdProc NRCoroInjectObjCmd;
+static Tcl_NRPostProc NRPostInvoke;
+
+MODULE_SCOPE const TclStubs tclStubs;
+
+/*
+ * Magical counts for the number of arguments accepted by a coroutine command
+ * after particular kinds of [yield].
+ */
+
+#define CORO_ACTIVATE_YIELD    PTR2INT(NULL)
+#define CORO_ACTIVATE_YIELDM   PTR2INT(NULL)+1
+
+#define COROUTINE_ARGUMENTS_SINGLE_OPTIONAL     (-1)
+#define COROUTINE_ARGUMENTS_ARBITRARY           (-2)
+
+/*
+ * 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. */
+    Tcl_ObjCmdProc *nreProc;	/* NR-based function for command */
+    int flags;			/* Various flag bits, as defined below. */
+} CmdInfo;
+
+#define CMD_IS_SAFE         1   /* Whether this command is part of the set of
+                                 * commands present by default in a safe
+                                 * interpreter. */
+/* CMD_COMPILES_EXPANDED - Whether the compiler for this command can handle
+ * expansion for itself rather than needing the generic layer to take care of
+ * it for it. Defined in tclInt.h. */
+
+/*
+ * The built-in commands, and the functions that implement them:
+ */
+
+static const CmdInfo builtInCmds[] = {
+    /*
+     * Commands in the generic core.
+     */
+
+    {"append",		Tcl_AppendObjCmd,	TclCompileAppendCmd,	NULL,	CMD_IS_SAFE},
+    {"apply",		Tcl_ApplyObjCmd,	NULL,			TclNRApplyObjCmd,	CMD_IS_SAFE},
+    {"break",		Tcl_BreakObjCmd,	TclCompileBreakCmd,	NULL,	CMD_IS_SAFE},
+#ifndef EXCLUDE_OBSOLETE_COMMANDS
+    {"case",		Tcl_CaseObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+#endif
+    {"catch",		Tcl_CatchObjCmd,	TclCompileCatchCmd,	TclNRCatchObjCmd,	CMD_IS_SAFE},
+    {"concat",		Tcl_ConcatObjCmd,	TclCompileConcatCmd,	NULL,	CMD_IS_SAFE},
+    {"continue",	Tcl_ContinueObjCmd,	TclCompileContinueCmd,	NULL,	CMD_IS_SAFE},
+    {"coroutine",	NULL,			NULL,			TclNRCoroutineObjCmd,	CMD_IS_SAFE},
+    {"error",		Tcl_ErrorObjCmd,	TclCompileErrorCmd,	NULL,	CMD_IS_SAFE},
+    {"eval",		Tcl_EvalObjCmd,		NULL,			TclNREvalObjCmd,	CMD_IS_SAFE},
+    {"expr",		Tcl_ExprObjCmd,		TclCompileExprCmd,	TclNRExprObjCmd,	CMD_IS_SAFE},
+    {"for",		Tcl_ForObjCmd,		TclCompileForCmd,	TclNRForObjCmd,	CMD_IS_SAFE},
+    {"foreach",		Tcl_ForeachObjCmd,	TclCompileForeachCmd,	TclNRForeachCmd,	CMD_IS_SAFE},
+    {"format",		Tcl_FormatObjCmd,	TclCompileFormatCmd,	NULL,	CMD_IS_SAFE},
+    {"global",		Tcl_GlobalObjCmd,	TclCompileGlobalCmd,	NULL,	CMD_IS_SAFE},
+    {"if",		Tcl_IfObjCmd,		TclCompileIfCmd,	TclNRIfObjCmd,	CMD_IS_SAFE},
+    {"incr",		Tcl_IncrObjCmd,		TclCompileIncrCmd,	NULL,	CMD_IS_SAFE},
+    {"join",		Tcl_JoinObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"lappend",		Tcl_LappendObjCmd,	TclCompileLappendCmd,	NULL,	CMD_IS_SAFE},
+    {"lassign",		Tcl_LassignObjCmd,	TclCompileLassignCmd,	NULL,	CMD_IS_SAFE},
+    {"lindex",		Tcl_LindexObjCmd,	TclCompileLindexCmd,	NULL,	CMD_IS_SAFE},
+    {"linsert",		Tcl_LinsertObjCmd,	TclCompileLinsertCmd,	NULL,	CMD_IS_SAFE},
+    {"list",		Tcl_ListObjCmd,		TclCompileListCmd,	NULL,	CMD_IS_SAFE|CMD_COMPILES_EXPANDED},
+    {"llength",		Tcl_LlengthObjCmd,	TclCompileLlengthCmd,	NULL,	CMD_IS_SAFE},
+    {"lmap",		Tcl_LmapObjCmd,		TclCompileLmapCmd,	TclNRLmapCmd,	CMD_IS_SAFE},
+    {"lrange",		Tcl_LrangeObjCmd,	TclCompileLrangeCmd,	NULL,	CMD_IS_SAFE},
+    {"lrepeat",		Tcl_LrepeatObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"lreplace",	Tcl_LreplaceObjCmd,	TclCompileLreplaceCmd,	NULL,	CMD_IS_SAFE},
+    {"lreverse",	Tcl_LreverseObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"lsearch",		Tcl_LsearchObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"lset",		Tcl_LsetObjCmd,		TclCompileLsetCmd,	NULL,	CMD_IS_SAFE},
+    {"lsort",		Tcl_LsortObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"package",		Tcl_PackageObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"proc",		Tcl_ProcObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"regexp",		Tcl_RegexpObjCmd,	TclCompileRegexpCmd,	NULL,	CMD_IS_SAFE},
+    {"regsub",		Tcl_RegsubObjCmd,	TclCompileRegsubCmd,	NULL,	CMD_IS_SAFE},
+    {"rename",		Tcl_RenameObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"return",		Tcl_ReturnObjCmd,	TclCompileReturnCmd,	NULL,	CMD_IS_SAFE},
+    {"scan",		Tcl_ScanObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"set",		Tcl_SetObjCmd,		TclCompileSetCmd,	NULL,	CMD_IS_SAFE},
+    {"split",		Tcl_SplitObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"subst",		Tcl_SubstObjCmd,	TclCompileSubstCmd,	TclNRSubstObjCmd,	CMD_IS_SAFE},
+    {"switch",		Tcl_SwitchObjCmd,	TclCompileSwitchCmd,	TclNRSwitchObjCmd, CMD_IS_SAFE},
+    {"tailcall",	NULL,			TclCompileTailcallCmd,	TclNRTailcallObjCmd,	CMD_IS_SAFE},
+    {"throw",		Tcl_ThrowObjCmd,	TclCompileThrowCmd,	NULL,	CMD_IS_SAFE},
+    {"trace",		Tcl_TraceObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"try",		Tcl_TryObjCmd,		TclCompileTryCmd,	TclNRTryObjCmd,	CMD_IS_SAFE},
+    {"unset",		Tcl_UnsetObjCmd,	TclCompileUnsetCmd,	NULL,	CMD_IS_SAFE},
+    {"uplevel",		Tcl_UplevelObjCmd,	NULL,			TclNRUplevelObjCmd,	CMD_IS_SAFE},
+    {"upvar",		Tcl_UpvarObjCmd,	TclCompileUpvarCmd,	NULL,	CMD_IS_SAFE},
+    {"variable",	Tcl_VariableObjCmd,	TclCompileVariableCmd,	NULL,	CMD_IS_SAFE},
+    {"while",		Tcl_WhileObjCmd,	TclCompileWhileCmd,	TclNRWhileObjCmd,	CMD_IS_SAFE},
+    {"yield",		NULL,			TclCompileYieldCmd,	TclNRYieldObjCmd,	CMD_IS_SAFE},
+    {"yieldto",		NULL,			TclCompileYieldToCmd,	TclNRYieldToObjCmd,	CMD_IS_SAFE},
+
+    /*
+     * Commands in the OS-interface. Note that many of these are unsafe.
+     */
+
+    {"after",		Tcl_AfterObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"cd",		Tcl_CdObjCmd,		NULL,			NULL,	0},
+    {"close",		Tcl_CloseObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"eof",		Tcl_EofObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"exec",		Tcl_ExecObjCmd,		NULL,			NULL,	0},
+    {"exit",		Tcl_ExitObjCmd,		NULL,			NULL,	0},
+    {"fblocked",	Tcl_FblockedObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"fconfigure",	Tcl_FconfigureObjCmd,	NULL,			NULL,	0},
+    {"fcopy",		Tcl_FcopyObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"fileevent",	Tcl_FileEventObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"flush",		Tcl_FlushObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"gets",		Tcl_GetsObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"glob",		Tcl_GlobObjCmd,		NULL,			NULL,	0},
+    {"load",		Tcl_LoadObjCmd,		NULL,			NULL,	0},
+    {"open",		Tcl_OpenObjCmd,		NULL,			NULL,	0},
+    {"pid",		Tcl_PidObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"puts",		Tcl_PutsObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"pwd",		Tcl_PwdObjCmd,		NULL,			NULL,	0},
+    {"read",		Tcl_ReadObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"seek",		Tcl_SeekObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"socket",		Tcl_SocketObjCmd,	NULL,			NULL,	0},
+    {"source",		Tcl_SourceObjCmd,	NULL,			TclNRSourceObjCmd,	0},
+    {"tell",		Tcl_TellObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"time",		Tcl_TimeObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"unload",		Tcl_UnloadObjCmd,	NULL,			NULL,	0},
+    {"update",		Tcl_UpdateObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {"vwait",		Tcl_VwaitObjCmd,	NULL,			NULL,	CMD_IS_SAFE},
+    {NULL,		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}
+};
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFinalizeEvaluation --
+ *
+ *	Finalizes the script cancellation hash table.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFinalizeEvaluation(void)
+{
+    Tcl_MutexLock(&cancelLock);
+    if (cancelTableInitialized == 1) {
+	Tcl_DeleteHashTable(&cancelTable);
+	cancelTableInitialized = 0;
+    }
+    Tcl_MutexUnlock(&cancelLock);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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;
+    Tcl_HashEntry *hPtr;
+    int isNew;
+    CancelInfo *cancelInfo;
+    union {
+	char c[sizeof(short)];
+	short s;
+    } order;
+#ifdef TCL_COMPILE_STATS
+    ByteCodeStats *statsPtr;
+#endif /* TCL_COMPILE_STATS */
+    char mathFuncName[32];
+    CallFrame *framePtr;
+
+    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 must not be smaller than CallFrame");
+    }
+
+#if defined(_WIN32) && !defined(_WIN64)
+    if (sizeof(time_t) != 4) {
+	/*NOTREACHED*/
+	Tcl_Panic("<time.h> is not compatible with MSVC");
+    }
+    if ((TclOffset(Tcl_StatBuf,st_atime) != 32)
+	    || (TclOffset(Tcl_StatBuf,st_ctime) != 40)) {
+	/*NOTREACHED*/
+	Tcl_Panic("<sys/stat.h> is not compatible with MSVC");
+    }
+#endif
+
+    if (cancelTableInitialized == 0) {
+	Tcl_MutexLock(&cancelLock);
+	if (cancelTableInitialized == 0) {
+	    Tcl_InitHashTable(&cancelTable, TCL_ONE_WORD_KEYS);
+	    cancelTableInitialized = 1;
+	}
+	Tcl_MutexUnlock(&cancelLock);
+    }
+
+    /*
+     * 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 = 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;
+
+    TCL_CT_ASSERT(sizeof(iPtr->extra) <= sizeof(Tcl_HashTable));
+    iPtr->extra.optimizer = TclOptimizeBytecode;
+
+    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 = ckalloc(sizeof(Tcl_HashTable));
+    iPtr->lineBCPtr = ckalloc(sizeof(Tcl_HashTable));
+    iPtr->lineLAPtr = ckalloc(sizeof(Tcl_HashTable));
+    iPtr->lineLABCPtr = 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->errorStack = Tcl_NewListObj(0, NULL);
+    Tcl_IncrRefCount(iPtr->errorStack);
+    iPtr->resetErrorStack = 1;
+    TclNewLiteralStringObj(iPtr->upLiteral,"UP");
+    Tcl_IncrRefCount(iPtr->upLiteral);
+    TclNewLiteralStringObj(iPtr->callLiteral,"CALL");
+    Tcl_IncrRefCount(iPtr->callLiteral);
+    TclNewLiteralStringObj(iPtr->innerLiteral,"INNER");
+    Tcl_IncrRefCount(iPtr->innerLiteral);
+    iPtr->innerContext = Tcl_NewListObj(0, NULL);
+    Tcl_IncrRefCount(iPtr->innerContext);
+    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();
+
+    /* TIP #378 */
+#ifdef TCL_INTERP_DEBUG_FRAME
+    iPtr->flags |= INTERP_DEBUG_FRAME;
+#else
+    if (getenv("TCL_INTERP_DEBUG_FRAME") != NULL) {
+        iPtr->flags |= INTERP_DEBUG_FRAME;
+    }
+#endif
+
+    /*
+     * 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 = ckalloc(sizeof(CallFrame));
+    (void) Tcl_PushCallFrame(interp, (Tcl_CallFrame *) framePtr,
+	    (Tcl_Namespace *) iPtr->globalNsPtr, /*isProcCallFrame*/ 0);
+    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, INTERP_STACK_INITIAL_SIZE);
+
+    /*
+     * TIP #219, Tcl Channel Reflection API support.
+     */
+
+    iPtr->chanMsg = NULL;
+
+    /*
+     * TIP #285, Script cancellation support.
+     */
+
+    iPtr->asyncCancelMsg = Tcl_NewObj();
+
+    cancelInfo = ckalloc(sizeof(CancelInfo));
+    cancelInfo->interp = interp;
+
+    iPtr->asyncCancel = Tcl_AsyncCreate(CancelEvalProc, cancelInfo);
+    cancelInfo->async = iPtr->asyncCancel;
+    cancelInfo->result = NULL;
+    cancelInfo->length = 0;
+
+    Tcl_MutexLock(&cancelLock);
+    hPtr = Tcl_CreateHashEntry(&cancelTable, iPtr, &isNew);
+    Tcl_SetHashValue(hPtr, cancelInfo);
+    Tcl_MutexUnlock(&cancelLock);
+
+    /*
+     * 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;
+    memset(statsPtr->instructionCount, 0,
+	    sizeof(statsPtr->instructionCount));
+
+    statsPtr->totalSrcBytes = 0.0;
+    statsPtr->totalByteCodeBytes = 0.0;
+    statsPtr->currentSrcBytes = 0.0;
+    statsPtr->currentByteCodeBytes = 0.0;
+    memset(statsPtr->srcCount, 0, sizeof(statsPtr->srcCount));
+    memset(statsPtr->byteCodeCount, 0, sizeof(statsPtr->byteCodeCount));
+    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;
+    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.
+     */
+
+    TclResetRewriteEnsemble(interp, 1);
+
+    /*
+     * TIP#143: Initialise the resource limit support.
+     */
+
+    TclInitLimitSupport(interp);
+
+    /*
+     * Initialise the thread-specific data ekeko. Note that the thread's alloc
+     * cache was already initialised by the call to alloc the interp struct.
+     */
+
+#if defined(TCL_THREADS) && defined(USE_THREAD_ALLOC)
+    iPtr->allocCache = TclpGetAllocCache();
+#else
+    iPtr->allocCache = NULL;
+#endif
+    iPtr->pendingObjDataPtr = NULL;
+    iPtr->asyncReadyPtr = TclGetAsyncReadyPtr();
+    iPtr->deferredCallbacks = NULL;
+
+    /*
+     * 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++) {
+	if ((cmdInfoPtr->objProc == NULL)
+		&& (cmdInfoPtr->compileProc == NULL)
+		&& (cmdInfoPtr->nreProc == 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 = 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;
+            if (cmdInfoPtr->flags & CMD_COMPILES_EXPANDED) {
+                cmdPtr->flags |= CMD_COMPILES_EXPANDED;
+            }
+	    cmdPtr->importRefPtr = NULL;
+	    cmdPtr->tracePtr = NULL;
+	    cmdPtr->nreProc = cmdInfoPtr->nreProc;
+	    Tcl_SetHashValue(hPtr, cmdPtr);
+	}
+    }
+
+    /*
+     * Create the "array", "binary", "chan", "clock", "dict", "encoding",
+     * "file", "info", "namespace" and "string" ensembles. Note that all these
+     * commands (and their subcommands that are not present in the global
+     * namespace) are wholly safe *except* for "clock", "encoding" and "file".
+     */
+
+    TclInitArrayCmd(interp);
+    TclInitBinaryCmd(interp);
+    TclInitChanCmd(interp);
+    TclInitDictCmd(interp);
+    TclInitEncodingCmd(interp);
+    TclInitFileCmd(interp);
+    TclInitInfoCmd(interp);
+    TclInitNamespaceCmd(interp);
+    TclInitStringCmd(interp);
+    TclInitPrefixCmd(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 unsupported commands for debugging bytecode and objects.
+     */
+
+    Tcl_CreateObjCommand(interp, "::tcl::unsupported::disassemble",
+	    Tcl_DisassembleObjCmd, INT2PTR(0), NULL);
+    Tcl_CreateObjCommand(interp, "::tcl::unsupported::getbytecode",
+	    Tcl_DisassembleObjCmd, INT2PTR(1), NULL);
+    Tcl_CreateObjCommand(interp, "::tcl::unsupported::representation",
+	    Tcl_RepresentationCmd, NULL, NULL);
+
+    /* Adding the bytecode assembler command */
+    cmdPtr = (Command *) Tcl_NRCreateCommand(interp,
+            "::tcl::unsupported::assemble", Tcl_AssembleObjCmd,
+            TclNRAssembleObjCmd, NULL, NULL);
+    cmdPtr->compileProc = &TclCompileAssembleCmd;
+
+    Tcl_NRCreateCommand(interp, "::tcl::unsupported::inject", NULL,
+	    NRCoroInjectObjCmd, 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");
+    }
+#define MATH_FUNC_PREFIX_LEN 17 /* == strlen("::tcl::mathfunc::") */
+    memcpy(mathFuncName, "::tcl::mathfunc::", MATH_FUNC_PREFIX_LEN);
+    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);
+    if (mathopNSPtr == NULL) {
+	Tcl_Panic("can't create math operator namespace");
+    }
+    Tcl_Export(interp, mathopNSPtr, "*", 1);
+#define MATH_OP_PREFIX_LEN 15 /* == strlen("::tcl::mathop::") */
+    memcpy(mathFuncName, "::tcl::mathop::", MATH_OP_PREFIX_LEN);
+    for (opcmdInfoPtr=mathOpCmds ; opcmdInfoPtr->name!=NULL ; opcmdInfoPtr++){
+	TclOpCmdClientData *occdPtr = 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);
+
+    /*
+     * TIP #440: Declare the name of the script engine to be "Tcl".
+     */
+
+    Tcl_SetVar2(interp, "tcl_platform", "engine", "Tcl",
+	    TCL_GLOBAL_ONLY);
+
+    /*
+     * 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);
+
+    if (TclTommath_Init(interp) != TCL_OK) {
+	Tcl_Panic("%s", Tcl_GetString(Tcl_GetObjResult(interp)));
+    }
+
+    if (TclOOInit(interp) != TCL_OK) {
+	Tcl_Panic("%s", Tcl_GetString(Tcl_GetObjResult(interp)));
+    }
+
+    /*
+     * Only build in zlib support if we've successfully detected a library to
+     * compile and link against.
+     */
+
+#ifdef HAVE_ZLIB
+    if (TclZlibInit(interp) != TCL_OK) {
+	Tcl_Panic("%s", Tcl_GetString(Tcl_GetObjResult(interp)));
+    }
+#endif
+
+    TOP_CB(iPtr) = NULL;
+    return interp;
+}
+
+static void
+DeleteOpCmdClientData(
+    ClientData clientData)
+{
+    TclOpCmdClientData *occdPtr = clientData;
+
+    ckfree(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->flags & CMD_IS_SAFE)) {
+	    Tcl_HideCommand(interp, cmdInfoPtr->name, cmdInfoPtr->name);
+	}
+    }
+    TclMakeEncodingCommandSafe(interp); /* Ugh! */
+    TclMakeFileCommandSafe(interp);     /* Ugh! */
+    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 = ckalloc(sizeof(AssocData));
+    Tcl_HashEntry *hPtr;
+
+    sprintf(buffer, "Assoc Data Key #%d", *assocDataCounterPtr);
+    (*assocDataCounterPtr)++;
+
+    if (iPtr->assocData == NULL) {
+	iPtr->assocData = 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 = Tcl_GetHashValue(hPtr);
+	if ((dPtr->proc == proc) && (dPtr->clientData == clientData)) {
+	    ckfree(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 = 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 = 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(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;
+    int i;
+
+    /*
+     * Punt if there is an error in the Tcl_Release/Tcl_Preserve matchup,
+	 * unless we are exiting.
+     */
+
+    if ((iPtr->numLevels > 0) && !TclInExit()) {
+	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;
+    }
+
+    /*
+     * TIP #285, Script cancellation support. Delete this interp from the
+     * global hash table of CancelInfo structs.
+     */
+
+    Tcl_MutexLock(&cancelLock);
+    hPtr = Tcl_FindHashEntry(&cancelTable, (char *) iPtr);
+    if (hPtr != NULL) {
+	CancelInfo *cancelInfo = Tcl_GetHashValue(hPtr);
+
+	if (cancelInfo != NULL) {
+	    if (cancelInfo->result != NULL) {
+		ckfree(cancelInfo->result);
+	    }
+	    ckfree(cancelInfo);
+	}
+
+	Tcl_DeleteHashEntry(hPtr);
+    }
+
+    if (iPtr->asyncCancel != NULL) {
+	Tcl_AsyncDelete(iPtr->asyncCancel);
+	iPtr->asyncCancel = NULL;
+    }
+
+    if (iPtr->asyncCancelMsg != NULL) {
+	Tcl_DecrRefCount(iPtr->asyncCancelMsg);
+	iPtr->asyncCancelMsg = NULL;
+    }
+    Tcl_MutexUnlock(&cancelLock);
+
+    /*
+     * 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.
+     */
+
+    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_GetHashValue(hPtr));
+	}
+	Tcl_DeleteHashTable(hTablePtr);
+	ckfree(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(dPtr);
+	}
+	Tcl_DeleteHashTable(hTablePtr);
+	ckfree(hTablePtr);
+    }
+
+    /*
+     * Pop the root frame pointer and finish deleting the global
+     * namespace. The order is important [Bug 1658572].
+     */
+
+    if ((iPtr->framePtr != iPtr->rootFramePtr) && !TclInExit()) {
+	Tcl_Panic("DeleteInterpProc: popping rootCallFrame with other frames on top");
+    }
+    Tcl_PopCallFrame(interp);
+    ckfree(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);
+    iPtr->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;
+    }
+    Tcl_DecrRefCount(iPtr->errorStack);
+    iPtr->errorStack = NULL;
+    Tcl_DecrRefCount(iPtr->upLiteral);
+    Tcl_DecrRefCount(iPtr->callLiteral);
+    Tcl_DecrRefCount(iPtr->innerLiteral);
+    Tcl_DecrRefCount(iPtr->innerContext);
+    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);
+    }
+    if (iPtr->scriptFile) {
+	Tcl_DecrRefCount(iPtr->scriptFile);
+	iPtr->scriptFile = NULL;
+    }
+    Tcl_DecrRefCount(iPtr->emptyObjPtr);
+    iPtr->emptyObjPtr = NULL;
+
+    resPtr = iPtr->resolverPtr;
+    while (resPtr) {
+	nextResPtr = resPtr->nextPtr;
+	ckfree(resPtr->name);
+	ckfree(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.
+     */
+
+    for (hPtr = Tcl_FirstHashEntry(iPtr->linePBodyPtr, &search);
+	    hPtr != NULL;
+	    hPtr = Tcl_NextHashEntry(&search)) {
+	CmdFrame *cfPtr = Tcl_GetHashValue(hPtr);
+	Proc *procPtr = (Proc *) Tcl_GetHashKey(iPtr->linePBodyPtr, hPtr);
+
+	procPtr->iPtr = NULL;
+	if (cfPtr) {
+	    if (cfPtr->type == TCL_LOCATION_SOURCE) {
+		Tcl_DecrRefCount(cfPtr->data.eval.path);
+	    }
+	    ckfree(cfPtr->line);
+	    ckfree(cfPtr);
+	}
+	Tcl_DeleteHashEntry(hPtr);
+    }
+    Tcl_DeleteHashTable(iPtr->linePBodyPtr);
+    ckfree(iPtr->linePBodyPtr);
+    iPtr->linePBodyPtr = NULL;
+
+    /*
+     * See also tclCompile.c, TclCleanupByteCode
+     */
+
+    for (hPtr = Tcl_FirstHashEntry(iPtr->lineBCPtr, &search);
+	    hPtr != NULL;
+	    hPtr = Tcl_NextHashEntry(&search)) {
+	ExtCmdLoc *eclPtr = Tcl_GetHashValue(hPtr);
+
+	if (eclPtr->type == TCL_LOCATION_SOURCE) {
+	    Tcl_DecrRefCount(eclPtr->path);
+	}
+	for (i=0; i< eclPtr->nuloc; i++) {
+	    ckfree(eclPtr->loc[i].line);
+	}
+
+	if (eclPtr->loc != NULL) {
+	    ckfree(eclPtr->loc);
+	}
+
+	ckfree(eclPtr);
+	Tcl_DeleteHashEntry(hPtr);
+    }
+    Tcl_DeleteHashTable(iPtr->lineBCPtr);
+    ckfree(iPtr->lineBCPtr);
+    iPtr->lineBCPtr = NULL;
+
+    /*
+     * Location stack for uplevel/eval/... scripts which were passed through
+     * proc arguments. Actually we track all arguments as we do not and cannot
+     * know which arguments will be used as scripts and which will not.
+     */
+
+    if (iPtr->lineLAPtr->numEntries && !TclInExit()) {
+	/*
+	 * 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 && !TclInExit()) {
+	/*
+	 * 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(iPtr->lineLABCPtr);
+    iPtr->lineLABCPtr = NULL;
+
+    /*
+     * Squelch the tables of traces on variables and searches over arrays in
+     * the in the interpreter.
+     */
+
+    Tcl_DeleteHashTable(&iPtr->varTraces);
+    Tcl_DeleteHashTable(&iPtr->varSearches);
+
+    ckfree(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_SetObjResult(interp, Tcl_NewStringObj(
+		"cannot use namespace qualifiers in hidden command"
+		" token (rename)", -1));
+        Tcl_SetErrorCode(interp, "TCL", "VALUE", "HIDDENTOKEN", 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_SetObjResult(interp, Tcl_NewStringObj(
+                "can only hide global namespace commands (use rename then hide)",
+                -1));
+        Tcl_SetErrorCode(interp, "TCL", "HIDE", "NON_GLOBAL", NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Initialize the hidden command table if necessary.
+     */
+
+    hiddenCmdTablePtr = iPtr->hiddenCmdTablePtr;
+    if (hiddenCmdTablePtr == NULL) {
+	hiddenCmdTablePtr = ckalloc(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_SetObjResult(interp, Tcl_ObjPrintf(
+                "hidden command named \"%s\" already exists",
+                hiddenCmdToken));
+        Tcl_SetErrorCode(interp, "TCL", "HIDE", "ALREADY_HIDDEN", 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_SetObjResult(interp, Tcl_NewStringObj(
+                "cannot expose to a namespace (use expose to toplevel, then rename)",
+                -1));
+        Tcl_SetErrorCode(interp, "TCL", "EXPOSE", "NON_GLOBAL", 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_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown hidden command \"%s\"", hiddenCmdToken));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "HIDDENTOKEN",
+                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_SetObjResult(interp, Tcl_NewStringObj(
+		"trying to expose a non-global command namespace command",
+		-1));
+	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_SetObjResult(interp, Tcl_ObjPrintf(
+                "exposed command \"%s\" already exists", cmdName));
+        Tcl_SetErrorCode(interp, "TCL", "EXPOSE", "COMMAND_EXISTS", NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Command resolvers (per-interp, per-namespace) might have resolved to a
+     * command for the given namespace scope with this command not being
+     * registered with the namespace's command table. During BC compilation,
+     * the so-resolved command turns into a CmdName literal. Without
+     * invalidating a possible CmdName literal here explicitly, such literals
+     * keep being reused while pointing to overhauled commands.
+     */
+
+    TclInvalidateCmdLiteral(interp, cmdName, nsPtr);
+
+    /*
+     * 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);
+	cmdPtr->refCount++;
+	if (cmdPtr->importRefPtr) {
+	    cmdPtr->flags |= CMD_REDEF_IN_PROGRESS;
+	}
+
+	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
+
+	if (cmdPtr->flags & CMD_REDEF_IN_PROGRESS) {
+	    oldRefPtr = cmdPtr->importRefPtr;
+	    cmdPtr->importRefPtr = NULL;
+	}
+	TclCleanupCommandMacro(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 {
+	/*
+	 * Command resolvers (per-interp, per-namespace) might have resolved
+	 * to a command for the given namespace scope with this command not
+	 * being registered with the namespace's command table. During BC
+	 * compilation, the so-resolved command turns into a CmdName literal.
+	 * Without invalidating a possible CmdName literal here explicitly,
+	 * such literals keep being reused while pointing to overhauled
+	 * commands.
+	 */
+
+	TclInvalidateCmdLiteral(interp, tail, nsPtr);
+
+	/*
+	 * 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 = 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;
+    cmdPtr->nreProc = 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 a command named "cmdName" already exists for interp, it is
+ *	first deleted.  Then the new command is created from the arguments.
+ *	[***] (See below for exception).
+ *
+ *	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. */
+
+	/*
+	 * [***] This is wrong.  See Tcl Bug a16752c252.
+	 * However, this buggy behavior is kept under particular
+	 * circumstances to accommodate deployed binaries of the
+	 * "tclcompiler" program. http://sourceforge.net/projects/tclpro/
+	 * that crash if the bug is fixed.
+	 */
+
+	if (cmdPtr->objProc == TclInvokeStringCommand
+		&& cmdPtr->clientData == clientData
+		&& cmdPtr->deleteData == clientData
+		&& cmdPtr->deleteProc == deleteProc) {
+	    cmdPtr->objProc = proc;
+	    cmdPtr->objClientData = 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.
+	 */
+
+	cmdPtr->refCount++;
+	if (cmdPtr->importRefPtr) {
+	    cmdPtr->flags |= CMD_REDEF_IN_PROGRESS;
+	}
+
+	Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
+
+	if (cmdPtr->flags & CMD_REDEF_IN_PROGRESS) {
+	    oldRefPtr = cmdPtr->importRefPtr;
+	    cmdPtr->importRefPtr = NULL;
+	}
+	TclCleanupCommandMacro(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 {
+	/*
+	 * Command resolvers (per-interp, per-namespace) might have resolved
+	 * to a command for the given namespace scope with this command not
+	 * being registered with the namespace's command table. During BC
+	 * compilation, the so-resolved command turns into a CmdName literal.
+	 * Without invalidating a possible CmdName literal here explicitly,
+	 * such literals keep being reused while pointing to overhauled
+	 * commands.
+	 */
+
+	TclInvalidateCmdLiteral(interp, tail, nsPtr);
+
+	/*
+	 * 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 = 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;
+    cmdPtr->nreProc = 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 =
+	    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_ObjCmdProc,
+ *	TclInvokeObjectCommand 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 = clientData;
+    Tcl_Obj *objPtr;
+    int i, length, result;
+    Tcl_Obj **objv =
+	    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.
+     */
+
+    if (cmdPtr->objProc != NULL) {
+	result = cmdPtr->objProc(cmdPtr->objClientData, interp, argc, objv);
+    } else {
+	result = Tcl_NRCallObjProc(interp, cmdPtr->nreProc,
+		cmdPtr->objClientData, 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_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't %s \"%s\": command doesn't exist",
+		((newName == NULL)||(*newName == '\0'))? "delete":"rename",
+		oldName));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND", oldName, 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_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't rename to \"%s\": bad command name", newName));
+        Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", NULL);
+	result = TCL_ERROR;
+	goto done;
+    }
+    if (Tcl_FindHashEntry(&newNsPtr->cmdTable, newTail) != NULL) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't rename to \"%s\": command already exists", newName));
+        Tcl_SetErrorCode(interp, "TCL", "OPERATION", "RENAME",
+                "TARGET_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);
+
+    /*
+     * Command resolvers (per-interp, per-namespace) might have resolved to a
+     * command for the given namespace scope with this command not being
+     * registered with the namespace's command table. During BC compilation,
+     * the so-resolved command turns into a CmdName literal. Without
+     * invalidating a possible CmdName literal here explicitly, such literals
+     * keep being reused while pointing to overhauled commands.
+     */
+
+    TclInvalidateCmdLiteral(interp, newTail, 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) {
+	TclDStringAppendLiteral(&newFullName, "::");
+    }
+    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 == 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;
+	cmdPtr->nreProc = NULL;
+    } else {
+	if (infoPtr->objProc != cmdPtr->objProc) {
+	    cmdPtr->nreProc = NULL;
+	    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 == 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 == 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-- <= 1) {
+		ckfree(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.
+     */
+    if (!(cmdPtr->flags & CMD_REDEF_IN_PROGRESS)) {
+	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;
+    }
+
+    /*
+     * A number of tests for particular kinds of commands are done by checking
+     * whether the objProc field holds a known value. Set the field to NULL so
+     * that such tests won't have false positives when applied to deleted
+     * commands.
+     */
+
+    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
+     * TclNRExecuteByteCode looks up the command in the command hashtable).
+     */
+
+    TclCleanupCommandMacro(cmdPtr);
+    return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * CallCommandTraces --
+ *
+ *	Abstraction of the code to call traces on a command.
+ *
+ * Results:
+ *	Currently always NULL.
+ *
+ * Side effects:
+ *	Anything; this may recursively evaluate scripts and code exists to do
+ *	just that.
+ *
+ *----------------------------------------------------------------------
+ */
+
+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-- <= 1) {
+	    ckfree(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;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * CancelEvalProc --
+ *
+ *	Marks this interpreter as being canceled. This causes current
+ *	executions to be unwound as the interpreter enters a state where it
+ *	refuses to execute more commands or handle [catch] or [try], yet the
+ *	interpreter is still able to execute further commands after the
+ *	cancelation is cleared (unlike if it is deleted).
+ *
+ * Results:
+ *	The value given for the code argument.
+ *
+ * Side effects:
+ *	Transfers a message from the cancelation message to the interpreter.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+CancelEvalProc(
+    ClientData clientData,	/* Interp to cancel the script in progress. */
+    Tcl_Interp *interp,		/* Ignored */
+    int code)			/* Current return code from command. */
+{
+    CancelInfo *cancelInfo = clientData;
+    Interp *iPtr;
+
+    if (cancelInfo != NULL) {
+	Tcl_MutexLock(&cancelLock);
+	iPtr = (Interp *) cancelInfo->interp;
+
+	if (iPtr != NULL) {
+	    /*
+	     * Setting the CANCELED flag will cause the script in progress to
+	     * be canceled as soon as possible. The core honors this flag at
+	     * all the necessary places to ensure script cancellation is
+	     * responsive. Extensions can check for this flag by calling
+	     * Tcl_Canceled and checking if TCL_ERROR is returned or they can
+	     * choose to ignore the script cancellation flag and the
+	     * associated functionality altogether. Currently, the only other
+	     * flag we care about here is the TCL_CANCEL_UNWIND flag (from
+	     * Tcl_CancelEval). We do not want to simply combine all the flags
+	     * from original Tcl_CancelEval call with the interp flags here
+	     * just in case the caller passed flags that might cause behaviour
+	     * unrelated to script cancellation.
+	     */
+
+	    TclSetCancelFlags(iPtr, cancelInfo->flags | CANCELED);
+
+	    /*
+	     * Now, we must set the script cancellation flags on all the slave
+	     * interpreters belonging to this one.
+	     */
+
+	    TclSetSlaveCancelFlags((Tcl_Interp *) iPtr,
+		    cancelInfo->flags | CANCELED, 0);
+
+	    /*
+	     * Create the result object now so that Tcl_Canceled can avoid
+	     * locking the cancelLock mutex.
+	     */
+
+	    if (cancelInfo->result != NULL) {
+		Tcl_SetStringObj(iPtr->asyncCancelMsg, cancelInfo->result,
+			cancelInfo->length);
+	    } else {
+		Tcl_SetObjLength(iPtr->asyncCancelMsg, 0);
+	    }
+	}
+	Tcl_MutexUnlock(&cancelLock);
+    }
+
+    return code;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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(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 = ckalloc(sizeof(OldMathFuncData));
+
+    data->proc = proc;
+    data->numArgs = numArgs;
+    data->argTypes = ckalloc(numArgs * sizeof(Tcl_ValueType));
+    memcpy(data->argTypes, argTypes, numArgs * sizeof(Tcl_ValueType));
+    data->clientData = clientData;
+
+    Tcl_DStringInit(&bigName);
+    TclDStringAppendLiteral(&bigName, "::tcl::mathfunc::");
+    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 = 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(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 (TclGetWideIntFromObj(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(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(args);
+		return TCL_ERROR;
+	    }
+	    valuePtr = Tcl_GetObjResult(interp);
+	    TclGetWideIntFromObj(NULL, valuePtr, &args[k].wideValue);
+	    Tcl_ResetResult(interp);
+	    break;
+	}
+    }
+
+    /*
+     * Call the function.
+     */
+
+    errno = 0;
+    result = dataPtr->proc(dataPtr->clientData, interp, args, &funcResult);
+    ckfree(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(dataPtr->argTypes);
+    ckfree(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_SetObjResult(interp, Tcl_ObjPrintf(
+                "unknown math function \"%s\"", name));
+	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "MATHFUNC", name, NULL);
+	*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)
+{
+    Tcl_Obj *script = Tcl_NewStringObj("::info functions ", -1);
+    Tcl_Obj *result;
+    Tcl_InterpState state;
+
+    if (pattern) {
+	Tcl_Obj *patternObj = Tcl_NewStringObj(pattern, -1);
+	Tcl_Obj *arg = Tcl_NewListObj(1, &patternObj);
+
+	Tcl_AppendObjToObj(script, arg);
+	Tcl_DecrRefCount(arg);	/* Should tear down patternObj too */
+    }
+
+    state = Tcl_SaveInterpState(interp, TCL_OK);
+    Tcl_IncrRefCount(script);
+    if (TCL_OK == Tcl_EvalObjEx(interp, script, 0)) {
+	result = Tcl_DuplicateObj(Tcl_GetObjResult(interp));
+    } else {
+	result = Tcl_NewObj();
+    }
+    Tcl_DecrRefCount(script);
+    Tcl_RestoreInterpState(interp, state);
+
+    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)
+{
+    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_SetObjResult(interp, Tcl_NewStringObj(
+		"attempt to call eval in deleted interpreter", -1));
+	Tcl_SetErrorCode(interp, "TCL", "IDELETE",
+		"attempt to call eval in deleted interpreter", NULL);
+	return TCL_ERROR;
+    }
+
+    if (iPtr->execEnvPtr->rewind) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Make sure the script being evaluated (if any) has not been canceled.
+     */
+
+    if (TclCanceled(iPtr) &&
+	    (TCL_OK != Tcl_Canceled(interp, TCL_LEAVE_ERR_MSG))) {
+	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)) {
+	return TCL_OK;
+    }
+
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(
+	    "too many nested evaluations (infinite loop?)", -1));
+    Tcl_SetErrorCode(interp, "TCL", "LIMIT", "STACK", NULL);
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclResetCancellation --
+ *
+ *	Reset the script cancellation flags if the nesting level
+ *	(iPtr->numLevels) for the interp is zero or argument force is
+ *	non-zero.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	The script cancellation flags for the interp may be reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclResetCancellation(
+    Tcl_Interp *interp,
+    int force)
+{
+    register Interp *iPtr = (Interp *) interp;
+
+    if (iPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    if (force || (iPtr->numLevels == 0)) {
+	TclUnsetCancelFlags(iPtr);
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_Canceled --
+ *
+ *	Check if the script in progress has been canceled, i.e.,
+ *	Tcl_CancelEval was called for this interpreter or any of its master
+ *	interpreters.
+ *
+ * Results:
+ *	The return value is TCL_OK if the script evaluation has not been
+ *	canceled, TCL_ERROR otherwise.
+ *
+ *	If "flags" contains TCL_LEAVE_ERR_MSG, an error message is returned in
+ *	the interpreter's result object. Otherwise, the interpreter's result
+ *	object is left unchanged. If "flags" contains TCL_CANCEL_UNWIND,
+ *	TCL_ERROR will only be returned if the script evaluation is being
+ *	completely unwound.
+ *
+ * Side effects:
+ *	The CANCELED flag for the interp will be reset if it is set.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_Canceled(
+    Tcl_Interp *interp,
+    int flags)
+{
+    register Interp *iPtr = (Interp *) interp;
+
+    /*
+     * Has the current script in progress for this interpreter been canceled
+     * or is the stack being unwound due to the previous script cancellation?
+     */
+
+    if (!TclCanceled(iPtr)) {
+        return TCL_OK;
+    }
+
+    /*
+     * The CANCELED flag is a one-shot flag that is reset immediately upon
+     * being detected; however, if the TCL_CANCEL_UNWIND flag is set we will
+     * continue to report that the script in progress has been canceled
+     * thereby allowing the evaluation stack for the interp to be fully
+     * unwound.
+     */
+
+    iPtr->flags &= ~CANCELED;
+
+    /*
+     * The CANCELED flag was detected and reset; however, if the caller
+     * specified the TCL_CANCEL_UNWIND flag, we only return TCL_ERROR
+     * (indicating that the script in progress has been canceled) if the
+     * evaluation stack for the interp is being fully unwound.
+     */
+
+    if ((flags & TCL_CANCEL_UNWIND) && !(iPtr->flags & TCL_CANCEL_UNWIND)) {
+        return TCL_OK;
+    }
+
+    /*
+     * If the TCL_LEAVE_ERR_MSG flags bit is set, place an error in the
+     * interp's result; otherwise, we leave it alone.
+     */
+
+    if (flags & TCL_LEAVE_ERR_MSG) {
+        const char *id, *message = NULL;
+        int length;
+
+        /*
+         * Setup errorCode variables so that we can differentiate between
+         * being canceled and unwound.
+         */
+
+        if (iPtr->asyncCancelMsg != NULL) {
+            message = Tcl_GetStringFromObj(iPtr->asyncCancelMsg, &length);
+        } else {
+            length = 0;
+        }
+
+        if (iPtr->flags & TCL_CANCEL_UNWIND) {
+            id = "IUNWIND";
+            if (length == 0) {
+                message = "eval unwound";
+            }
+        } else {
+            id = "ICANCEL";
+            if (length == 0) {
+                message = "eval canceled";
+            }
+        }
+
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(message, -1));
+        Tcl_SetErrorCode(interp, "TCL", "CANCEL", id, message, NULL);
+    }
+
+    /*
+     * Return TCL_ERROR to the caller (not necessarily just the Tcl core
+     * itself) that indicates further processing of the script or command in
+     * progress should halt gracefully and as soon as possible.
+     */
+
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_CancelEval --
+ *
+ *	This function schedules the cancellation of the current script in the
+ *	given interpreter.
+ *
+ * Results:
+ *	The return value is a standard Tcl completion code such as TCL_OK or
+ *	TCL_ERROR. Since the interp may belong to a different thread, no error
+ *	message can be left in the interp's result.
+ *
+ * Side effects:
+ *	The script in progress in the specified interpreter will be canceled
+ *	with TCL_ERROR after asynchronous handlers are invoked at the next
+ *	Tcl_Canceled check.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_CancelEval(
+    Tcl_Interp *interp,		/* Interpreter in which to cancel the
+				 * script. */
+    Tcl_Obj *resultObjPtr,	/* The script cancellation error message or
+				 * NULL for a default error message. */
+    ClientData clientData,	/* Passed to CancelEvalProc. */
+    int flags)			/* Collection of OR-ed bits that control
+				 * the cancellation of the script. Only
+				 * TCL_CANCEL_UNWIND is currently
+				 * supported. */
+{
+    Tcl_HashEntry *hPtr;
+    CancelInfo *cancelInfo;
+    int code = TCL_ERROR;
+    const char *result;
+
+    if (interp == NULL) {
+	return TCL_ERROR;
+    }
+
+    Tcl_MutexLock(&cancelLock);
+    if (cancelTableInitialized != 1) {
+	/*
+	 * No CancelInfo hash table (Tcl_CreateInterp has never been called?)
+	 */
+
+	goto done;
+    }
+    hPtr = Tcl_FindHashEntry(&cancelTable, (char *) interp);
+    if (hPtr == NULL) {
+	/*
+	 * No CancelInfo record for this interpreter.
+	 */
+
+	goto done;
+    }
+    cancelInfo = Tcl_GetHashValue(hPtr);
+
+    /*
+     * Populate information needed by the interpreter thread to fulfill the
+     * cancellation request. Currently, clientData is ignored. If the
+     * TCL_CANCEL_UNWIND flags bit is set, the script in progress is not
+     * allowed to catch the script cancellation because the evaluation stack
+     * for the interp is completely unwound.
+     */
+
+    if (resultObjPtr != NULL) {
+	result = Tcl_GetStringFromObj(resultObjPtr, &cancelInfo->length);
+	cancelInfo->result = ckrealloc(cancelInfo->result,cancelInfo->length);
+	memcpy(cancelInfo->result, result, (size_t) cancelInfo->length);
+	TclDecrRefCount(resultObjPtr);	/* Discard their result object. */
+    } else {
+	cancelInfo->result = NULL;
+	cancelInfo->length = 0;
+    }
+    cancelInfo->clientData = clientData;
+    cancelInfo->flags = flags;
+    Tcl_AsyncMark(cancelInfo->async);
+    code = TCL_OK;
+
+  done:
+    Tcl_MutexUnlock(&cancelLock);
+    return code;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_InterpActive --
+ *
+ *	Returns non-zero if the specified interpreter is in use, i.e. if there
+ *	is an evaluation currently active in the interpreter.
+ *
+ * Results:
+ *	See above.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_InterpActive(
+    Tcl_Interp *interp)
+{
+    return ((Interp *) interp)->numLevels > 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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:
+ *	Always pushes a callback. Other side effects depend 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, TCL_EVAL_INVOKE and
+				 * TCL_EVAL_NOERR are currently supported. */
+{
+    int result;
+    NRE_callback *rootPtr = TOP_CB(interp);
+
+    result = TclNREvalObjv(interp, objc, objv, flags, NULL);
+    return TclNRRunCallbacks(interp, result, rootPtr);
+}
+
+int
+TclNREvalObjv(
+    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, TCL_EVAL_INVOKE and
+				 * TCL_EVAL_NOERR are currently supported. */
+    Command *cmdPtr)		/* NULL if the Command is to be looked up
+				 * here, otherwise the pointer to the
+				 * requested Command struct to be invoked. */
+{
+    Interp *iPtr = (Interp *) interp;
+
+    /*
+     * data[1] stores a marker for use by tailcalls; it will be set to 1 by
+     * command redirectors (imports, alias, ensembles) so that tailcall skips
+     * this callback (that marks the end of the target command) and goes back
+     * to the end of the source command.
+     */
+
+    if (iPtr->deferredCallbacks) {
+        iPtr->deferredCallbacks = NULL;
+    } else {
+	TclNRAddCallback(interp, NRCommand, NULL, NULL, NULL, NULL);
+    }
+
+    iPtr->numLevels++;
+    TclNRAddCallback(interp, EvalObjvCore, cmdPtr, INT2PTR(flags),
+	    INT2PTR(objc), objv);
+    return TCL_OK;
+}
+
+static int
+EvalObjvCore(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Command *cmdPtr = NULL, *preCmdPtr = data[0];
+    int flags = PTR2INT(data[1]);
+    int objc = PTR2INT(data[2]);
+    Tcl_Obj **objv = data[3];
+    Interp *iPtr = (Interp *) interp;
+    Namespace *lookupNsPtr = NULL;
+    int enterTracesDone = 0;
+
+    /*
+     * Push records for task to be done on return, in INVERSE order. First, if
+     * needed, the exception handlers (as they should happen last).
+     */
+
+    if (!(flags & TCL_EVAL_NOERR)) {
+	TEOV_PushExceptionHandlers(interp, objc, objv, flags);
+    }
+
+    if (TCL_OK != TclInterpReady(interp)) {
+	return TCL_ERROR;
+    }
+
+    if (objc == 0) {
+	return TCL_OK;
+    }
+
+    if (TclLimitExceeded(iPtr->limit)) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Configure evaluation context to match the requested flags.
+     */
+
+    if (iPtr->lookupNsPtr) {
+
+	/*
+	 * Capture the namespace we should do command name resolution in, as
+	 * instructed by our caller sneaking it in to us in a private interp
+	 * field.  Clear that field right away so we cannot possibly have its
+	 * use leak where it should not.  The sneaky message pass is done.
+	 *
+	 * Use of this mechanism overrides the TCL_EVAL_GLOBAL flag.
+	 * TODO: Is that a bug?
+	 */
+
+	lookupNsPtr = iPtr->lookupNsPtr;
+	iPtr->lookupNsPtr = NULL;
+    } else if (flags & TCL_EVAL_INVOKE) {
+	lookupNsPtr = iPtr->globalNsPtr;
+    } else {
+
+	/*
+	 * TCL_EVAL_INVOKE was not set: clear rewrite rules
+	 */
+
+	TclResetRewriteEnsemble(interp, 1);
+
+	if (flags & TCL_EVAL_GLOBAL) {
+	    TEOV_SwitchVarFrame(interp);
+	    lookupNsPtr = iPtr->globalNsPtr;
+	}
+    }
+
+    /*
+     * Lookup the Command to dispatch.
+     */
+
+    reresolve:
+    assert(cmdPtr == NULL);
+    if (preCmdPtr) {
+	/* Caller gave it to us */
+	if (!(preCmdPtr->flags & CMD_IS_DELETED)) {
+	    /* So long as it exists, use it. */
+	    cmdPtr = preCmdPtr;
+	} else if (flags & TCL_EVAL_NORESOLVE) {
+	    /*
+	     * When it's been deleted, and we're told not to attempt
+	     * resolving it ourselves, all we can do is raise an error.
+	     */
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "attempt to invoke a deleted command"));
+	    Tcl_SetErrorCode(interp, "TCL", "EVAL", "DELETEDCOMMAND", NULL);
+	    return TCL_ERROR;
+	}
+    }
+    if (cmdPtr == NULL) {
+	cmdPtr = TEOV_LookupCmdFromObj(interp, objv[0], lookupNsPtr);
+	if (!cmdPtr) {
+	    return TEOV_NotFound(interp, objc, objv, lookupNsPtr);
+	}
+    }
+
+    if (enterTracesDone || iPtr->tracePtr
+	    || (cmdPtr->flags & CMD_HAS_EXEC_TRACES)) {
+
+	Tcl_Obj *commandPtr = TclGetSourceFromFrame(
+		flags & TCL_EVAL_SOURCE_IN_FRAME ?  iPtr->cmdFramePtr : NULL,
+		objc, objv);
+	Tcl_IncrRefCount(commandPtr);
+
+	if (!enterTracesDone) {
+
+	    int code = TEOV_RunEnterTraces(interp, &cmdPtr, commandPtr,
+		    objc, objv);
+
+	    /*
+	     * Send any exception from enter traces back as an exception
+	     * raised by the traced command.
+	     * TODO: Is this a bug?  Letting an execution trace BREAK or
+	     * CONTINUE or RETURN in the place of the traced command?
+	     * Would either converting all exceptions to TCL_ERROR, or
+	     * just swallowing them be better?  (Swallowing them has the
+	     * problem of permanently hiding program errors.)
+	     */
+
+	    if (code != TCL_OK) {
+		Tcl_DecrRefCount(commandPtr);
+		return code;
+	    }
+
+	    /*
+	     * If the enter traces made the resolved cmdPtr unusable, go
+	     * back and resolve again, but next time don't run enter
+	     * traces again.
+	     */
+
+	    if (cmdPtr == NULL) {
+		enterTracesDone = 1;
+		Tcl_DecrRefCount(commandPtr);
+		goto reresolve;
+	    }
+	}
+
+	/*
+	 * Schedule leave traces.  Raise the refCount on the resolved
+	 * cmdPtr, so that when it passes to the leave traces we know
+	 * it's still valid.
+	 */
+
+	cmdPtr->refCount++;
+	TclNRAddCallback(interp, TEOV_RunLeaveTraces, INT2PTR(objc),
+		    commandPtr, cmdPtr, objv);
+    }
+
+    TclNRAddCallback(interp, Dispatch,
+	    cmdPtr->nreProc ? cmdPtr->nreProc : cmdPtr->objProc,
+	    cmdPtr->objClientData, INT2PTR(objc), objv);
+    return TCL_OK;
+}
+
+static int
+Dispatch(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Tcl_ObjCmdProc *objProc = data[0];
+    ClientData clientData = data[1];
+    int objc = PTR2INT(data[2]);
+    Tcl_Obj **objv = data[3];
+    Interp *iPtr = (Interp *) interp;
+
+#ifdef USE_DTRACE
+    if (TCL_DTRACE_CMD_ARGS_ENABLED()) {
+	const 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);
+	const char *a[6]; int i[2];
+
+	TclDTraceInfo(info, a, i);
+	TCL_DTRACE_CMD_INFO(a[0], a[1], a[2], a[3], i[0], i[1], a[4], a[5]);
+	TclDecrRefCount(info);
+    }
+    if ((TCL_DTRACE_CMD_RETURN_ENABLED() || TCL_DTRACE_CMD_RESULT_ENABLED())
+	    && objc) {
+	TclNRAddCallback(interp, DTraceCmdReturn, objv[0], NULL, NULL, NULL);
+    }
+    if (TCL_DTRACE_CMD_ENTRY_ENABLED() && objc) {
+	TCL_DTRACE_CMD_ENTRY(TclGetString(objv[0]), objc - 1,
+		(Tcl_Obj **)(objv + 1));
+    }
+#endif /* USE_DTRACE */
+
+    iPtr->cmdCount++;
+    return objProc(clientData, interp, objc, objv);
+}
+
+int
+TclNRRunCallbacks(
+    Tcl_Interp *interp,
+    int result,
+    struct NRE_callback *rootPtr)
+				/* All callbacks down to rootPtr not inclusive
+				 * are to be run. */
+{
+    Interp *iPtr = (Interp *) interp;
+    NRE_callback *callbackPtr;
+    Tcl_NRPostProc *procPtr;
+
+    /*
+     * 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.
+     *
+     * This only needs to be done for the first item in the list: all other
+     * are for NR function calls, and those are Tcl_Obj based.
+     */
+
+    if (*(iPtr->result) != 0) {
+	(void) Tcl_GetObjResult(interp);
+    }
+
+    while (TOP_CB(interp) != rootPtr) {
+	callbackPtr = TOP_CB(interp);
+	procPtr = callbackPtr->procPtr;
+	TOP_CB(interp) = callbackPtr->nextPtr;
+	result = procPtr(callbackPtr->data, interp, result);
+	TCLNR_FREE(interp, callbackPtr);
+    }
+    return result;
+}
+
+static int
+NRCommand(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+
+    iPtr->numLevels--;
+
+     /*
+      * If there is a tailcall, schedule it next
+      */
+
+    if (data[1] && (data[1] != INT2PTR(1))) {
+        TclNRAddCallback(interp, TclNRTailcallEval, data[1], NULL, NULL, NULL);
+    }
+
+    /* OPT ??
+     * Do not interrupt a series of cleanups with async or limit checks:
+     * just check at the end?
+     */
+
+    if (TclAsyncReady(iPtr)) {
+	result = Tcl_AsyncInvoke(interp, result);
+    }
+    if ((result == TCL_OK) && TclCanceled(iPtr)) {
+	result = Tcl_Canceled(interp, TCL_LEAVE_ERR_MSG);
+    }
+    if (result == TCL_OK && TclLimitReady(iPtr->limit)) {
+	result = Tcl_LimitCheck(interp);
+    }
+
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TEOV_Exception	 -
+ * TEOV_LookupCmdFromObj -
+ * TEOV_RunEnterTraces	 -
+ * TEOV_RunLeaveTraces	 -
+ * TEOV_NotFound	 -
+ *
+ *	These are helper functions for Tcl_EvalObjv.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+TEOV_PushExceptionHandlers(
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[],
+    int flags)
+{
+    Interp *iPtr = (Interp *) interp;
+
+    /*
+     * If any error processing is necessary, push the appropriate records.
+     * Note that we have to push them in the inverse order: first the one that
+     * has to run last.
+     */
+
+    if (!(flags & TCL_EVAL_INVOKE)) {
+	/*
+	 * Error messages
+	 */
+
+	TclNRAddCallback(interp, TEOV_Error, INT2PTR(objc),
+		(ClientData) objv, NULL, NULL);
+    }
+
+    if (iPtr->numLevels == 1) {
+	/*
+	 * No CONTINUE or BREAK at level 0, manage RETURN
+	 */
+
+	TclNRAddCallback(interp, TEOV_Exception, INT2PTR(iPtr->evalFlags),
+		NULL, NULL, NULL);
+    }
+}
+
+static void
+TEOV_SwitchVarFrame(
+    Tcl_Interp *interp)
+{
+    Interp *iPtr = (Interp *) interp;
+
+    /*
+     * Change the varFrame to be the rootVarFrame, and push a record to
+     * restore things at the end.
+     */
+
+    TclNRAddCallback(interp, TEOV_RestoreVarFrame, iPtr->varFramePtr, NULL,
+	    NULL, NULL);
+    iPtr->varFramePtr = iPtr->rootFramePtr;
+}
+
+static int
+TEOV_RestoreVarFrame(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    ((Interp *) interp)->varFramePtr = data[0];
+    return result;
+}
+
+static int
+TEOV_Exception(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    int allowExceptions = (PTR2INT(data[0]) & TCL_ALLOW_EXCEPTIONS);
+
+    if (result != TCL_OK) {
+	if (result == TCL_RETURN) {
+	    result = TclUpdateReturnInfo(iPtr);
+	}
+	if ((result != TCL_ERROR) && !allowExceptions) {
+	    ProcessUnexpectedResult(interp, result);
+	    result = TCL_ERROR;
+	}
+    }
+
+    /*
+     * We are returning to level 0, so should process TclResetCancellation. As
+     * numLevels has not *yet* been decreased, do not call it: do the thing
+     * here directly.
+     */
+
+    TclUnsetCancelFlags(iPtr);
+    return result;
+}
+
+static int
+TEOV_Error(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    Tcl_Obj *listPtr;
+    const char *cmdString;
+    int cmdLen;
+    int objc = PTR2INT(data[0]);
+    Tcl_Obj **objv = data[1];
+
+    if ((result == TCL_ERROR) && !(iPtr->flags & ERR_ALREADY_LOGGED)){
+	/*
+	 * If there was an error, a command string will be needed for the
+	 * error log: get it out of the itemPtr. The details depend on the
+	 * type.
+	 */
+
+	listPtr = Tcl_NewListObj(objc, objv);
+	cmdString = Tcl_GetStringFromObj(listPtr, &cmdLen);
+	Tcl_LogCommandInfo(interp, cmdString, cmdString, cmdLen);
+	Tcl_DecrRefCount(listPtr);
+    }
+    iPtr->flags &= ~ERR_ALREADY_LOGGED;
+    return result;
+}
+
+static int
+TEOV_NotFound(
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[],
+    Namespace *lookupNsPtr)
+{
+    Command * cmdPtr;
+    Interp *iPtr = (Interp *) interp;
+    int i, newObjc, handlerObjc;
+    Tcl_Obj **newObjv, **handlerObjv;
+    CallFrame *varFramePtr = iPtr->varFramePtr;
+    Namespace *currNsPtr = NULL;/* Used to check for and invoke any registered
+				 * unknown command handler for the current
+				 * namespace (TIP 181). */
+    Namespace *savedNsPtr = NULL;
+
+    currNsPtr = varFramePtr->nsPtr;
+    if ((currNsPtr == NULL) || (currNsPtr->unknownHandlerPtr == NULL)) {
+	currNsPtr = iPtr->globalNsPtr;
+	if (currNsPtr == NULL) {
+	    Tcl_Panic("Tcl_EvalObjv: 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 = 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.
+     *
+     * In this case we worry a bit less about recursion for now, and call the
+     * "blocking" interface.
+     */
+
+    cmdPtr = TEOV_LookupCmdFromObj(interp, newObjv[0], lookupNsPtr);
+    if (cmdPtr == NULL) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "invalid command name \"%s\"", TclGetString(objv[0])));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
+                TclGetString(objv[0]), NULL);
+
+	/*
+	 * Release any resources we locked and allocated during the handler
+	 * call.
+	 */
+
+	for (i = 0; i < handlerObjc; ++i) {
+	    Tcl_DecrRefCount(newObjv[i]);
+	}
+	TclStackFree(interp, newObjv);
+	return TCL_ERROR;
+    }
+
+    if (lookupNsPtr) {
+	savedNsPtr = varFramePtr->nsPtr;
+	varFramePtr->nsPtr = lookupNsPtr;
+    }
+    TclSkipTailcall(interp);
+    TclNRAddCallback(interp, TEOV_NotFoundCallback, INT2PTR(handlerObjc),
+	    newObjv, savedNsPtr, NULL);
+    return TclNREvalObjv(interp, newObjc, newObjv, TCL_EVAL_NOERR, NULL);
+}
+
+static int
+TEOV_NotFoundCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    int objc = PTR2INT(data[0]);
+    Tcl_Obj **objv = data[1];
+    Namespace *savedNsPtr = data[2];
+
+    int i;
+
+    if (savedNsPtr) {
+	iPtr->varFramePtr->nsPtr = savedNsPtr;
+    }
+
+    /*
+     * Release any resources we locked and allocated during the handler call.
+     */
+
+    for (i = 0; i < objc; ++i) {
+	Tcl_DecrRefCount(objv[i]);
+    }
+    TclStackFree(interp, objv);
+
+    return result;
+}
+
+static int
+TEOV_RunEnterTraces(
+    Tcl_Interp *interp,
+    Command **cmdPtrPtr,
+    Tcl_Obj *commandPtr,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    Interp *iPtr = (Interp *) interp;
+    Command *cmdPtr = *cmdPtrPtr;
+    int newEpoch, cmdEpoch = cmdPtr->cmdEpoch;
+    int length, traceCode = TCL_OK;
+    const char *command = Tcl_GetStringFromObj(commandPtr, &length);
+
+    /*
+     * Call trace functions.
+     * 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 = TclCheckInterpTraces(interp, command, length,
+		cmdPtr, TCL_OK, TCL_TRACE_ENTER_EXEC, objc, objv);
+    }
+    if ((cmdPtr->flags & CMD_HAS_EXEC_TRACES) && (traceCode == TCL_OK)) {
+	traceCode = TclCheckExecutionTraces(interp, command, length,
+		cmdPtr, TCL_OK, TCL_TRACE_ENTER_EXEC, objc, objv);
+    }
+    newEpoch = cmdPtr->cmdEpoch;
+    TclCleanupCommandMacro(cmdPtr);
+
+    if (traceCode != TCL_OK) {
+	if (traceCode == TCL_ERROR) {
+	    Tcl_Obj *info;
+
+	    TclNewLiteralStringObj(info, "\n    (enter trace on \"");
+	    Tcl_AppendLimitedToObj(info, command, length, 55, "...");
+	    Tcl_AppendToObj(info, "\")", 2);
+	    Tcl_AppendObjToErrorInfo(interp, info);
+	    iPtr->flags |= ERR_ALREADY_LOGGED;
+	}
+	return traceCode;
+    }
+    if (cmdEpoch != newEpoch) {
+	*cmdPtrPtr = NULL;
+    }
+    return TCL_OK;
+}
+
+static int
+TEOV_RunLeaveTraces(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    int traceCode = TCL_OK;
+    int objc = PTR2INT(data[0]);
+    Tcl_Obj *commandPtr = data[1];
+    Command *cmdPtr = data[2];
+    Tcl_Obj **objv = data[3];
+    int length;
+    const char *command = Tcl_GetStringFromObj(commandPtr, &length);
+
+    if (!(cmdPtr->flags & CMD_IS_DELETED)) {
+	if (cmdPtr->flags & CMD_HAS_EXEC_TRACES){
+	    traceCode = TclCheckExecutionTraces(interp, command, length,
+		    cmdPtr, result, TCL_TRACE_LEAVE_EXEC, objc, objv);
+	}
+	if (iPtr->tracePtr != NULL && traceCode == TCL_OK) {
+	    traceCode = TclCheckInterpTraces(interp, command, length,
+		    cmdPtr, result, TCL_TRACE_LEAVE_EXEC, objc, objv);
+	}
+    }
+
+    /*
+     * As cmdPtr is set, TclNRRunCallbacks is about to reduce the numlevels.
+     * Prevent that by resetting the cmdPtr field and dealing right here with
+     * cmdPtr->refCount.
+     */
+
+    TclCleanupCommandMacro(cmdPtr);
+
+    if (traceCode != TCL_OK) {
+	if (traceCode == TCL_ERROR) {
+	    Tcl_Obj *info;
+
+	    TclNewLiteralStringObj(info, "\n    (leave trace on \"");
+	    Tcl_AppendLimitedToObj(info, command, length, 55, "...");
+	    Tcl_AppendToObj(info, "\")", 2);
+	    Tcl_AppendObjToErrorInfo(interp, info);
+	    iPtr->flags |= ERR_ALREADY_LOGGED;
+	}
+	result = traceCode;
+    }
+    Tcl_DecrRefCount(commandPtr);
+    return result;
+}
+
+static inline Command *
+TEOV_LookupCmdFromObj(
+    Tcl_Interp *interp,
+    Tcl_Obj *namePtr,
+    Namespace *lookupNsPtr)
+{
+    Interp *iPtr = (Interp *) interp;
+    Command *cmdPtr;
+    Namespace *savedNsPtr = iPtr->varFramePtr->nsPtr;
+
+    if (lookupNsPtr) {
+	iPtr->varFramePtr->nsPtr = lookupNsPtr;
+    }
+    cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, namePtr);
+    iPtr->varFramePtr->nsPtr = savedNsPtr;
+    return cmdPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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
+				 * TclSubstTokens(), 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 = TclStackAlloc(interp, sizeof(Tcl_Parse));
+    CmdFrame *eeFramePtr = TclStackAlloc(interp, sizeof(CmdFrame));
+    Tcl_Obj **stackObjArray =
+	    TclStackAlloc(interp, minObjs * sizeof(Tcl_Obj *));
+    int *expandStack = TclStackAlloc(interp, minObjs * sizeof(int));
+    int *linesStack = TclStackAlloc(interp, minObjs * sizeof(int));
+				/* TIP #280 Structures for tracking of command
+				 * locations. */
+    int *clNext = NULL;		/* 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. */
+
+    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 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.
+     */
+
+    eeFramePtr->level = iPtr->cmdFramePtr ? iPtr->cmdFramePtr->level + 1 : 1;
+    eeFramePtr->framePtr = iPtr->framePtr;
+    eeFramePtr->nextPtr = iPtr->cmdFramePtr;
+    eeFramePtr->nline = 0;
+    eeFramePtr->line = NULL;
+    eeFramePtr->cmdObj = NULL;
+
+    iPtr->cmdFramePtr = eeFramePtr;
+    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;
+    }
+
+    iPtr->evalFlags = 0;
+    do {
+	if (Tcl_ParseCommand(interp, p, bytesLeft, 0, parsePtr) != TCL_OK) {
+	    code = TCL_ERROR;
+	    Tcl_LogCommandInfo(interp, script, parsePtr->commandStart,
+		    parsePtr->term + 1 - parsePtr->commandStart);
+	    goto posterror;
+	}
+
+	/*
+	 * 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;
+	    unsigned int objectsNeeded = 0;
+	    unsigned int numWords = parsePtr->numWords;
+
+	    /*
+	     * Generate an array of objects for the words of the command.
+	     */
+
+	    if (numWords > minObjs) {
+		expand =    ckalloc(numWords * sizeof(int));
+		objvSpace = ckalloc(numWords * sizeof(Tcl_Obj *));
+		lineSpace = ckalloc(numWords * sizeof(int));
+	    }
+	    expandRequested = 0;
+	    objv = objvSpace;
+	    lines = lineSpace;
+
+	    iPtr->cmdFramePtr = eeFramePtr->nextPtr;
+	    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) {
+		    break;
+		}
+		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]);
+			break;
+		    }
+		    expandRequested = 1;
+		    expand[objectsUsed] = 1;
+
+		    objectsNeeded += (numElements ? numElements : 1);
+		} else {
+		    expand[objectsUsed] = 0;
+		    objectsNeeded++;
+		}
+
+		if (wordCLNext) {
+		    TclContinuationsEnterDerived(objv[objectsUsed],
+			    wordStart - outerScript, wordCLNext);
+		}
+	    } /* for loop */
+	    iPtr->cmdFramePtr = eeFramePtr;
+	    if (code != TCL_OK) {
+		goto error;
+	    }
+	    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 =
+			    ckalloc(objectsNeeded * sizeof(Tcl_Obj *));
+		    lines = lineSpace = 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(copy);
+		}
+		if (lcopy != linesStack) {
+		    ckfree(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 = parsePtr->commandStart;
+	    eeFramePtr->len = parsePtr->commandSize;
+
+	    if (parsePtr->term ==
+		    parsePtr->commandStart + parsePtr->commandSize - 1) {
+		eeFramePtr->len--;
+	    }
+
+	    eeFramePtr->nline = objectsUsed;
+	    eeFramePtr->line = lines;
+
+	    TclArgumentEnter(interp, objv, objectsUsed, eeFramePtr);
+	    code = Tcl_EvalObjv(interp, objectsUsed, objv,
+		    TCL_EVAL_NOERR | TCL_EVAL_SOURCE_IN_FRAME);
+	    TclArgumentRelease(interp, objv, objectsUsed);
+
+	    eeFramePtr->line = NULL;
+	    eeFramePtr->nline = 0;
+	    if (eeFramePtr->cmdObj) {
+		Tcl_DecrRefCount(eeFramePtr->cmdObj);
+		eeFramePtr->cmdObj = NULL;
+	    }
+
+	    if (code != TCL_OK) {
+		goto error;
+	    }
+	    for (i = 0; i < objectsUsed; i++) {
+		Tcl_DecrRefCount(objv[i]);
+	    }
+	    objectsUsed = 0;
+	    if (objvSpace != stackObjArray) {
+		ckfree(objvSpace);
+		objvSpace = stackObjArray;
+		ckfree(lineSpace);
+		lineSpace = linesStack;
+	    }
+
+	    /*
+	     * Free expand separately since objvSpace could have been
+	     * reallocated above.
+	     */
+
+	    if (expand != expandStack) {
+		ckfree(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);
+    }
+ posterror:
+    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(objvSpace);
+	ckfree(lineSpace);
+    }
+    if (expand != expandStack) {
+	ckfree(expand);
+    }
+    iPtr->varFramePtr = savedVarFramePtr;
+
+ cleanup_return:
+    /*
+     * TIP #280. Release the local CmdFrame, and its contents.
+     */
+
+    iPtr->cmdFramePtr = iPtr->cmdFramePtr->nextPtr;
+    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(
+    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
+     * TclSubstTokens via TclParseBackslash.
+     *
+     * *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(
+    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, objv[i], &new);
+	if (new) {
+	    /*
+	     * The word is not on the stack yet, remember the current location
+	     * and initialize references.
+	     */
+
+	    cfwPtr = 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 = 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(
+    Tcl_Interp *interp,
+    Tcl_Obj **objv,
+    int objc)
+{
+    Interp *iPtr = (Interp *) interp;
+    int i;
+
+    for (i = 1; i < objc; i++) {
+	CFWord *cfwPtr;
+	Tcl_HashEntry *hPtr =
+		Tcl_FindHashEntry(iPtr->lineLAPtr, (char *) objv[i]);
+
+	if (!hPtr) {
+	    continue;
+	}
+	cfwPtr = Tcl_GetHashValue(hPtr);
+
+	cfwPtr->refCount--;
+	if (cfwPtr->refCount > 0) {
+	    continue;
+	}
+
+	ckfree(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(
+    Tcl_Interp *interp,
+    Tcl_Obj *objv[],
+    int objc,
+    void *codePtr,
+    CmdFrame *cfPtr,
+    int cmd,
+    int pc)
+{
+    ExtCmdLoc *eclPtr;
+    int word;
+    ECL *ePtr;
+    CFWordBC *lastPtr = NULL;
+    Interp *iPtr = (Interp *) interp;
+    Tcl_HashEntry *hePtr =
+	    Tcl_FindHashEntry(iPtr->lineBCPtr, (char *) codePtr);
+
+    if (!hePtr) {
+	return;
+    }
+    eclPtr = Tcl_GetHashValue(hePtr);
+    ePtr = &eclPtr->loc[cmd];
+
+    /*
+     * ePtr->nline is the number of words originally parsed.
+     *
+     * objc is the number of elements getting invoked.
+     *
+     * If they are not the same, we arrived here by compiling an
+     * ensemble dispatch.  Ensemble subcommands that lead to script
+     * evaluation are not supposed to get compiled, because a command
+     * such as [info level] in the script can expose some of the dispatch
+     * shenanigans.  This means that we don't have to tend to the
+     * housekeeping, and can escape now.
+     */
+
+    if (ePtr->nline != objc) {
+        return;
+    }
+
+    /*
+     * Having disposed of the ensemble cases, we can state...
+     * 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,
+		objv[word], &isnew);
+	    CFWordBC *cfwPtr = ckalloc(sizeof(CFWordBC));
+
+	    cfwPtr->framePtr = cfPtr;
+	    cfwPtr->obj = objv[word];
+	    cfwPtr->pc = pc;
+	    cfwPtr->word = word;
+	    cfwPtr->nextPtr = lastPtr;
+	    lastPtr = cfwPtr;
+
+	    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 = Tcl_GetHashValue(hPtr);
+	    }
+
+	    Tcl_SetHashValue(hPtr, cfwPtr);
+	}
+    } /* for */
+
+    cfPtr->litarg = lastPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * 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(
+    Tcl_Interp *interp,
+    CmdFrame *cfPtr)
+{
+    Interp *iPtr = (Interp *) interp;
+    CFWordBC *cfwPtr = (CFWordBC *) cfPtr->litarg;
+
+    while (cfwPtr) {
+	CFWordBC *nextPtr = cfwPtr->nextPtr;
+	Tcl_HashEntry *hPtr =
+		Tcl_FindHashEntry(iPtr->lineLABCPtr, (char *) cfwPtr->obj);
+	CFWordBC *xPtr = Tcl_GetHashValue(hPtr);
+
+	if (xPtr != cfwPtr) {
+	    Tcl_Panic("TclArgumentBC Enter/Release Mismatch");
+	}
+
+	if (cfwPtr->prevPtr) {
+	    Tcl_SetHashValue(hPtr, cfwPtr->prevPtr);
+	} else {
+	    Tcl_DeleteHashEntry(hPtr);
+	}
+
+	ckfree(cfwPtr);
+	cfwPtr = nextPtr;
+    }
+
+    cfPtr->litarg = NULL;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclArgumentGet --
+ *
+ *	This procedure is a helper for the TIP #280 uplevel extension. It
+ *	finds 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(
+    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 == NULL) || TclListObjIsCanonical(obj)) {
+	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 = 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 = 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.
+ *
+ *----------------------------------------------------------------------
+ */
+
+#undef Tcl_Eval
+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.
+ *
+ *	If the flag TCL_EVAL_DIRECT is passed in, the value of invoker
+ *	must be NULL.  Support for non-NULL invokers in that mode has
+ *	been removed since it was unused and untested.  Failure to
+ *	follow this limitation will lead to an assertion panic.
+ *
+ * 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. */
+{
+    int result = TCL_OK;
+    NRE_callback *rootPtr = TOP_CB(interp);
+
+    result = TclNREvalObjEx(interp, objPtr, flags, invoker, word);
+    return TclNRRunCallbacks(interp, result, rootPtr);
+}
+
+int
+TclNREvalObjEx(
+    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. */
+{
+    Interp *iPtr = (Interp *) interp;
+    int result;
+
+    /*
+     * This function consists of three independent blocks for: direct
+     * evaluation of canonical lists, compilation and bytecode execution and
+     * finally direct evaluation. Precisely one of these blocks will be run.
+     */
+
+    if (TclListObjIsCanonical(objPtr)) {
+	CmdFrame *eoFramePtr = NULL;
+	int objc;
+	Tcl_Obj *listPtr, **objv;
+
+	/*
+	 * Canonical List Optimization:  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.
+	 */
+
+	/*
+	 * Shimmer protection! Always pass an unshared obj. The caller could
+	 * incr the refCount of objPtr AFTER calling us! To be completely safe
+	 * we always make a copy. The callback takes care od the refCounts for
+	 * both listPtr and objPtr.
+	 *
+	 * TODO: Create a test to demo this need, or eliminate it.
+	 * FIXME OPT: preserve just the internal rep?
+	 */
+
+	Tcl_IncrRefCount(objPtr);
+	listPtr = TclListObjCopy(interp, objPtr);
+	Tcl_IncrRefCount(listPtr);
+
+	if (word != INT_MIN) {
+	    /*
+	     * TIP #280 Structures for tracking lines. As we know that this is
+	     * dynamic execution we ignore the invoker, even if known.
+	     *
+	     * 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.
+	     *
+	     * Note that we use (word==INTMIN) to signal that no command frame
+	     * should be pushed, as needed by alias and ensemble redirections.
+	     */
+
+	    eoFramePtr = TclStackAlloc(interp, sizeof(CmdFrame));
+	    eoFramePtr->nline = 0;
+	    eoFramePtr->line = NULL;
+
+	    eoFramePtr->type = TCL_LOCATION_EVAL;
+	    eoFramePtr->level = (iPtr->cmdFramePtr == NULL?
+		    1 : iPtr->cmdFramePtr->level + 1);
+	    eoFramePtr->framePtr = iPtr->framePtr;
+	    eoFramePtr->nextPtr = iPtr->cmdFramePtr;
+
+	    eoFramePtr->cmdObj = objPtr;
+	    eoFramePtr->cmd = NULL;
+	    eoFramePtr->len = 0;
+	    eoFramePtr->data.eval.path = NULL;
+
+	    iPtr->cmdFramePtr = eoFramePtr;
+
+	    flags |= TCL_EVAL_SOURCE_IN_FRAME;
+	}
+
+	TclMarkTailcall(interp);
+        TclNRAddCallback(interp, TEOEx_ListCallback, listPtr, eoFramePtr,
+		objPtr, NULL);
+
+	ListObjGetElements(listPtr, objc, objv);
+	return TclNREvalObjv(interp, objc, objv, flags, NULL);
+    }
+
+    if (!(flags & TCL_EVAL_DIRECT)) {
+	/*
+	 * 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);
+	ByteCode *codePtr;
+	CallFrame *savedVarFramePtr = NULL;	/* Saves old copy of
+						 * iPtr->varFramePtr in case
+						 * TCL_EVAL_GLOBAL was set. */
+
+        if (TclInterpReady(interp) != TCL_OK) {
+            return TCL_ERROR;
+        }
+	if (flags & TCL_EVAL_GLOBAL) {
+	    savedVarFramePtr = iPtr->varFramePtr;
+	    iPtr->varFramePtr = iPtr->rootFramePtr;
+	}
+	Tcl_IncrRefCount(objPtr);
+	codePtr = TclCompileObj(interp, objPtr, invoker, word);
+
+	TclNRAddCallback(interp, TEOEx_ByteCodeCallback, savedVarFramePtr,
+		objPtr, INT2PTR(allowExceptions), NULL);
+        return TclNRExecuteByteCode(interp, codePtr);
+    }
+
+    {
+	/*
+	 * We're not supposed to use the compiler or byte-code
+	 * interpreter. Let Tcl_EvalEx evaluate the command directly (and
+	 * probably more slowly).
+	 */
+
+	const char *script;
+	int numSrcBytes;
+
+	/*
+	 * 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;
+
+	assert(invoker == NULL);
+
+	iPtr->scriptCLLocPtr = TclContinuationsGet(objPtr);
+
+	Tcl_IncrRefCount(objPtr);
+
+	script = Tcl_GetStringFromObj(objPtr, &numSrcBytes);
+	result = Tcl_EvalEx(interp, script, numSrcBytes, flags);
+
+	TclDecrRefCount(objPtr);
+
+	iPtr->scriptCLLocPtr = saveCLLocPtr;
+	return result;
+    }
+}
+
+static int
+TEOEx_ByteCodeCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    CallFrame *savedVarFramePtr = data[0];
+    Tcl_Obj *objPtr = data[1];
+    int allowExceptions = PTR2INT(data[2]);
+
+    if (iPtr->numLevels == 0) {
+	if (result == TCL_RETURN) {
+	    result = TclUpdateReturnInfo(iPtr);
+	}
+	if ((result != TCL_OK) && (result != TCL_ERROR) && !allowExceptions) {
+	    const char *script;
+	    int numSrcBytes;
+
+	    ProcessUnexpectedResult(interp, result);
+	    result = TCL_ERROR;
+	    script = Tcl_GetStringFromObj(objPtr, &numSrcBytes);
+	    Tcl_LogCommandInfo(interp, script, script, numSrcBytes);
+	}
+
+	/*
+	 * We are returning to level 0, so should call TclResetCancellation.
+	 * Let us just unset the flags inline.
+	 */
+
+	TclUnsetCancelFlags(iPtr);
+    }
+    iPtr->evalFlags = 0;
+
+    /*
+     * Restore the callFrame if this was a TCL_EVAL_GLOBAL.
+     */
+
+    if (savedVarFramePtr) {
+	iPtr->varFramePtr = savedVarFramePtr;
+    }
+
+    TclDecrRefCount(objPtr);
+    return result;
+}
+
+static int
+TEOEx_ListCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    Tcl_Obj *listPtr = data[0];
+    CmdFrame *eoFramePtr = data[1];
+    Tcl_Obj *objPtr = data[2];
+
+    /*
+     * Remove the cmdFrame
+     */
+
+    if (eoFramePtr) {
+	iPtr->cmdFramePtr = eoFramePtr->nextPtr;
+	TclStackFree(interp, eoFramePtr);
+    }
+    TclDecrRefCount(objPtr);
+    TclDecrRefCount(listPtr);
+
+    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. */
+{
+    char buf[TCL_INTEGER_SPACE];
+
+    Tcl_ResetResult(interp);
+    if (returnCode == TCL_BREAK) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"invoked \"break\" outside of a loop", -1));
+    } else if (returnCode == TCL_CONTINUE) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"invoked \"continue\" outside of a loop", -1));
+    } else {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"command returned bad code: %d", returnCode));
+    }
+    sprintf(buf, "%d", returnCode);
+    Tcl_SetErrorCode(interp, "TCL", "UNEXPECTED_RESULT_CODE", buf, NULL);
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *
+ * 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.
+     */
+
+    (void) TclPushStackFrame(interp, &framePtr, nsPtr, /*isProcFrame*/0);
+    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. */
+{
+    if (interp == NULL) {
+	return TCL_ERROR;
+    }
+    if ((objc < 1) || (objv == NULL)) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "illegal argument vector", -1));
+	return TCL_ERROR;
+    }
+    if ((flags & TCL_INVOKE_HIDDEN) == 0) {
+	Tcl_Panic("TclObjInvoke: called without TCL_INVOKE_HIDDEN");
+    }
+    return Tcl_NRCallObjProc(interp, TclNRInvoke, NULL, objc, objv);
+}
+
+int
+TclNRInvoke(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    register Interp *iPtr = (Interp *) interp;
+    Tcl_HashTable *hTblPtr;	/* Table of hidden commands. */
+    const char *cmdName;	/* Name of the command from objv[0]. */
+    Tcl_HashEntry *hPtr = NULL;
+    Command *cmdPtr;
+
+    cmdName = TclGetString(objv[0]);
+    hTblPtr = iPtr->hiddenCmdTablePtr;
+    if (hTblPtr != NULL) {
+	hPtr = Tcl_FindHashEntry(hTblPtr, cmdName);
+    }
+    if (hPtr == NULL) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "invalid hidden command name \"%s\"", cmdName));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "HIDDENTOKEN", cmdName,
+                NULL);
+	return TCL_ERROR;
+    }
+    cmdPtr = Tcl_GetHashValue(hPtr);
+
+    /* Avoid the exception-handling brain damage when numLevels == 0 . */
+    iPtr->numLevels++;
+    Tcl_NRAddCallback(interp, NRPostInvoke, NULL, NULL, NULL, NULL);
+
+    /*
+     * Normal command resolution of objv[0] isn't going to find cmdPtr.
+     * That's the whole point of **hidden** commands.  So tell the
+     * Eval core machinery not to even try (and risk finding something wrong).
+     */
+
+    return TclNREvalObjv(interp, objc, objv, TCL_EVAL_NORESOLVE, cmdPtr);
+}
+
+static int
+NRPostInvoke(
+    ClientData clientData[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *)interp;
+    iPtr->numLevels--;
+    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_SetObjResult(interp, Tcl_NewIntObj(0));
+    } 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.
+ *
+ *----------------------------------------------------------------------
+ */
+
+#undef Tcl_AddObjErrorInfo
+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.
+ *
+ *----------------------------------------------------------------------
+ */
+
+#undef Tcl_AddErrorInfo
+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(iPtr->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.
+ *
+ *----------------------------------------------------------------------
+ */
+
+#undef Tcl_GlobalEval
+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 (TclGetWideIntFromObj(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));
+    Tcl_SetErrorCode(interp, "ARITH", "DOMAIN",
+	    "domain error: argument not in valid range", NULL);
+    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) {
+	    goto unChanged;
+	} else if (l == (long)0) {
+	    const char *string = objv[1]->bytes;
+	    if (string) {
+		while (*string != '0') {
+		    if (*string == '-') {
+			Tcl_SetObjResult(interp, Tcl_NewLongObj(0));
+			return TCL_OK;
+		    }
+		    string++;
+		}
+	    }
+	    goto unChanged;
+	} else if (l == LONG_MIN) {
+	    TclBNInitBignumFromLong(&big, l);
+	    goto tooLarge;
+	}
+	Tcl_SetObjResult(interp, Tcl_NewLongObj(-l));
+	return TCL_OK;
+    }
+
+    if (type == TCL_NUMBER_DOUBLE) {
+	double d = *((const double *) ptr);
+	static const double poszero = 0.0;
+
+	/*
+	 * We need to distinguish here between positive 0.0 and negative -0.0.
+	 * [Bug 2954959]
+	 */
+
+	if (d == -0.0) {
+	    if (!memcmp(&d, &poszero, sizeof(double))) {
+		goto unChanged;
+	    }
+	} else if (d > -0.0) {
+	    goto unChanged;
+	}
+	Tcl_SetObjResult(interp, Tcl_NewDoubleObj(-d));
+	return TCL_OK;
+    }
+
+#ifndef TCL_WIDE_INT_IS_LONG
+    if (type == TCL_NUMBER_WIDE) {
+	Tcl_WideInt w = *((const Tcl_WideInt *) ptr);
+
+	if (w >= (Tcl_WideInt)0) {
+	    goto unChanged;
+	}
+	if (w == LLONG_MIN) {
+	    TclBNInitBignumFromWideInt(&big, w);
+	    goto tooLarge;
+	}
+	Tcl_SetObjResult(interp, Tcl_NewWideIntObj(-w));
+	return TCL_OK;
+    }
+#endif
+
+    if (type == TCL_NUMBER_BIG) {
+	if (mp_cmp_d((const mp_int *) ptr, 0) == MP_LT) {
+	    Tcl_GetBignumFromObj(NULL, objv[1], &big);
+	tooLarge:
+	    mp_neg(&big, &big);
+	    Tcl_SetObjResult(interp, Tcl_NewBignumObj(&big));
+	} else {
+	unChanged:
+	    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 (TclGetWideIntFromObj(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);
+	TclGetWideIntFromObj(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() + (PTR2INT(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));
+    Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
+}
+
+#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,
+    const char **args,
+    int *argsi)
+{
+    static Tcl_Obj *keys[10] = { NULL };
+    Tcl_Obj **k = keys, *val;
+    int i = 0;
+
+    if (!*k) {
+#define kini(s) TclNewLiteralStringObj(keys[i], s); i++
+	kini("cmd");	kini("type");	kini("proc");	kini("file");
+	kini("method");	kini("class");	kini("lambda");	kini("object");
+	kini("line");	kini("level");
+#undef kini
+    }
+    for (i = 0; i < 6; i++) {
+	Tcl_DictObjGet(NULL, info, *k++, &val);
+	args[i] = val ? TclGetString(val) : NULL;
+    }
+    /* no "proc" -> use "lambda" */
+    if (!args[2]) {
+	Tcl_DictObjGet(NULL, info, *k, &val);
+	args[2] = val ? TclGetString(val) : NULL;
+    }
+    k++;
+    /* no "class" -> use "object" */
+    if (!args[5]) {
+	Tcl_DictObjGet(NULL, info, *k, &val);
+	args[5] = 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;
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * DTraceCmdReturn --
+ *
+ *	NR callback for DTrace command return probes.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+DTraceCmdReturn(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    char *cmdName = TclGetString((Tcl_Obj *) data[0]);
+
+    if (TCL_DTRACE_CMD_RETURN_ENABLED()) {
+	TCL_DTRACE_CMD_RETURN(cmdName, result);
+    }
+    if (TCL_DTRACE_CMD_RESULT_ENABLED()) {
+	Tcl_Obj *r = Tcl_GetObjResult(interp);
+
+	TCL_DTRACE_CMD_RESULT(cmdName, result, TclGetString(r), r);
+    }
+    return result;
+}
+
+TCL_DTRACE_DEBUG_LOG()
+
+#endif /* USE_DTRACE */
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_NRCallObjProc --
+ *
+ *	This function calls an objProc directly while managing things properly
+ *	if it happens to be an NR objProc. It is meant to be used by extenders
+ *	that provide an NR implementation of a command, as this function
+ *	permits a trivial coding of the non-NR objProc.
+ *
+ * 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 objProc.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_NRCallObjProc(
+    Tcl_Interp *interp,
+    Tcl_ObjCmdProc *objProc,
+    ClientData clientData,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    NRE_callback *rootPtr = TOP_CB(interp);
+
+    TclNRAddCallback(interp, Dispatch, objProc, clientData,
+	    INT2PTR(objc), objv);
+    return TclNRRunCallbacks(interp, TCL_OK, rootPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_NRCreateCommand --
+ *
+ *	Define a new NRE-enabled 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_NRCreateCommand(
+    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, provides direct access for direct
+				 * calls. */
+    Tcl_ObjCmdProc *nreProc,	/* Object-based function to associate with
+				 * name, provides NR implementation */
+    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. */
+{
+    Command *cmdPtr = (Command *)
+	    Tcl_CreateObjCommand(interp,cmdName,proc,clientData,deleteProc);
+
+    cmdPtr->nreProc = nreProc;
+    return (Tcl_Command) cmdPtr;
+}
+
+/****************************************************************************
+ * Stuff for the public api
+ ****************************************************************************/
+
+int
+Tcl_NREvalObj(
+    Tcl_Interp *interp,
+    Tcl_Obj *objPtr,
+    int flags)
+{
+    return TclNREvalObjEx(interp, objPtr, flags, NULL, INT_MIN);
+}
+
+int
+Tcl_NREvalObjv(
+    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, TCL_EVAL_INVOKE and
+				 * TCL_EVAL_NOERR are currently supported. */
+{
+    return TclNREvalObjv(interp, objc, objv, flags, NULL);
+}
+
+int
+Tcl_NRCmdSwap(
+    Tcl_Interp *interp,
+    Tcl_Command cmd,
+    int objc,
+    Tcl_Obj *const objv[],
+    int flags)
+{
+    return TclNREvalObjv(interp, objc, objv, flags|TCL_EVAL_NOERR,
+	    (Command *) cmd);
+}
+
+/*****************************************************************************
+ * Tailcall related code
+ *****************************************************************************
+ *
+ * The steps of the tailcall dance are as follows:
+ *
+ *   1. when [tailcall] is invoked, it stores the corresponding callback in
+ *      the current CallFrame and returns TCL_RETURN
+ *   2. when the CallFrame is popped, it calls TclSetTailcall to store the
+ *      callback in the proper NRCommand callback - the spot where the command
+ *      that pushed the CallFrame is completely cleaned up
+ *   3. when the NRCommand callback runs, it schedules the tailcall callback
+ *      to run immediately after it returns
+ *
+ *   One delicate point is to properly define the NRCommand where the tailcall
+ *   will execute. There are functions whose purpose is to help define the
+ *   precise spot:
+ *     TclMarkTailcall: if the NEXT command to be pushed tailcalls, execution
+ *         should continue right here
+ *     TclSkipTailcall:  if the NEXT command to be pushed tailcalls, execution
+ *         should continue after the CURRENT command is fully returned ("skip
+ *         the next command: we are redirecting to it, tailcalls should run
+ *         after WE return")
+ *     TclPushTailcallPoint: the search for a tailcalling spot cannot traverse
+ *         this point. This is special for OO, as some of the oo constructs
+ *         that behave like commands may not push an NRCommand callback.
+ */
+
+void
+TclMarkTailcall(
+    Tcl_Interp *interp)
+{
+    Interp *iPtr = (Interp *) interp;
+
+    if (iPtr->deferredCallbacks == NULL) {
+	TclNRAddCallback(interp, NRCommand, NULL, NULL,
+                NULL, NULL);
+        iPtr->deferredCallbacks = TOP_CB(interp);
+    }
+}
+
+void
+TclSkipTailcall(
+    Tcl_Interp *interp)
+{
+    Interp *iPtr = (Interp *) interp;
+
+    TclMarkTailcall(interp);
+    iPtr->deferredCallbacks->data[1] = INT2PTR(1);
+}
+
+void
+TclPushTailcallPoint(
+    Tcl_Interp *interp)
+{
+    TclNRAddCallback(interp, NRCommand, NULL, NULL, NULL, NULL);
+    ((Interp *) interp)->numLevels++;
+}
+
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclSetTailcall --
+ *
+ *	Splice a tailcall command in the proper spot of the NRE callback
+ *	stack, so that it runs at the right time.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclSetTailcall(
+    Tcl_Interp *interp,
+    Tcl_Obj *listPtr)
+{
+    /*
+     * Find the splicing spot: right before the NRCommand of the thing
+     * being tailcalled. Note that we skip NRCommands marked by a 1 in data[1]
+     * (used by command redirectors).
+     */
+
+    NRE_callback *runPtr;
+
+    for (runPtr = TOP_CB(interp); runPtr; runPtr = runPtr->nextPtr) {
+        if (((runPtr->procPtr) == NRCommand) && !runPtr->data[1]) {
+            break;
+        }
+    }
+    if (!runPtr) {
+        Tcl_Panic("tailcall cannot find the right splicing spot: should not happen!");
+    }
+    runPtr->data[1] = listPtr;
+}
+
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNRTailcallObjCmd --
+ *
+ *	Prepare the tailcall as a list and store it in the current
+ *	varFrame. When the frame is later popped the tailcall will be spliced
+ *	at the proper place.
+ *
+ * Results:
+ *	The first NRCommand callback that is not marked to be skipped is
+ *	updated so that its data[1] field contains the tailcall list.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclNRTailcallObjCmd(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    Interp *iPtr = (Interp *) interp;
+
+    if (objc < 1) {
+	Tcl_WrongNumArgs(interp, 1, objv, "?command? ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    if (!(iPtr->varFramePtr->isProcCallFrame & 1)) {
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "tailcall can only be called from a proc, lambda or method", -1));
+        Tcl_SetErrorCode(interp, "TCL", "TAILCALL", "ILLEGAL", NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Invocation without args just clears a scheduled tailcall; invocation
+     * with an argument replaces any previously scheduled tailcall.
+     */
+
+    if (iPtr->varFramePtr->tailcallPtr) {
+        Tcl_DecrRefCount(iPtr->varFramePtr->tailcallPtr);
+        iPtr->varFramePtr->tailcallPtr = NULL;
+    }
+
+    /*
+     * Create the callback to actually evaluate the tailcalled
+     * command, then set it in the varFrame so that PopCallFrame can use it
+     * at the proper time.
+     */
+
+    if (objc > 1) {
+        Tcl_Obj *listPtr, *nsObjPtr;
+        Tcl_Namespace *nsPtr = (Tcl_Namespace *) iPtr->varFramePtr->nsPtr;
+        Tcl_Namespace *ns1Ptr;
+
+        /* The tailcall data is in a Tcl list: the first element is the
+         * namespace, the rest the command to be tailcalled. */
+
+        listPtr = Tcl_NewListObj(objc, objv);
+
+        nsObjPtr = Tcl_NewStringObj(nsPtr->fullName, -1);
+        if ((TCL_OK != TclGetNamespaceFromObj(interp, nsObjPtr, &ns1Ptr))
+                || (nsPtr != ns1Ptr)) {
+            Tcl_Panic("Tailcall failed to find the proper namespace");
+        }
+ 	TclListObjSetElement(interp, listPtr, 0, nsObjPtr);
+
+        iPtr->varFramePtr->tailcallPtr = listPtr;
+    }
+    return TCL_RETURN;
+}
+
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNRTailcallEval --
+ *
+ *	This NREcallback actually causes the tailcall to be evaluated.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclNRTailcallEval(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    Interp *iPtr = (Interp *) interp;
+    Tcl_Obj *listPtr = data[0], *nsObjPtr;
+    Tcl_Namespace *nsPtr;
+    int objc;
+    Tcl_Obj **objv;
+
+    Tcl_ListObjGetElements(interp, listPtr, &objc, &objv);
+    nsObjPtr = objv[0];
+
+    if (result == TCL_OK) {
+	result = TclGetNamespaceFromObj(interp, nsObjPtr, &nsPtr);
+    }
+
+    if (result != TCL_OK) {
+        /*
+         * Tailcall execution was preempted, eg by an intervening catch or by
+         * a now-gone namespace: cleanup and return.
+         */
+
+	Tcl_DecrRefCount(listPtr);
+        return result;
+    }
+
+    /*
+     * Perform the tailcall
+     */
+
+    TclMarkTailcall(interp);
+    TclNRAddCallback(interp, TclNRReleaseValues, listPtr, NULL, NULL,NULL);
+    iPtr->lookupNsPtr = (Namespace *) nsPtr;
+    return TclNREvalObjv(interp, objc-1, objv+1, 0, NULL);
+}
+
+int
+TclNRReleaseValues(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    int i = 0;
+    while (i < 4) {
+	if (data[i]) {
+	    Tcl_DecrRefCount((Tcl_Obj *) data[i]);
+	} else {
+	    break;
+	}
+	i++;
+    }
+    return result;
+}
+
+
+void
+Tcl_NRAddCallback(
+    Tcl_Interp *interp,
+    Tcl_NRPostProc *postProcPtr,
+    ClientData data0,
+    ClientData data1,
+    ClientData data2,
+    ClientData data3)
+{
+    if (!(postProcPtr)) {
+	Tcl_Panic("Adding a callback without an objProc?!");
+    }
+    TclNRAddCallback(interp, postProcPtr, data0, data1, data2, data3);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNRCoroutineObjCmd -- (and friends)
+ *
+ *	This object-based function is invoked to process the "coroutine" Tcl
+ *	command. It is heavily based on "apply".
+ *
+ * Results:
+ *	A standard Tcl object result value.
+ *
+ * Side effects:
+ *	A new procedure gets created.
+ *
+ * ** FIRST EXPERIMENTAL IMPLEMENTATION **
+ *
+ * It is fairly amateurish and not up to our standards - mainly in terms of
+ * error messages and [info] interaction. Just to test the infrastructure in
+ * teov and tebc.
+ *----------------------------------------------------------------------
+ */
+
+#define iPtr ((Interp *) interp)
+
+int
+TclNRYieldObjCmd(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+
+    if (objc > 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "?returnValue?");
+	return TCL_ERROR;
+    }
+
+    if (!corPtr) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "yield can only be called in a coroutine", -1));
+	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD", NULL);
+	return TCL_ERROR;
+    }
+
+    if (objc == 2) {
+	Tcl_SetObjResult(interp, objv[1]);
+    }
+
+    NRE_ASSERT(!COR_IS_SUSPENDED(corPtr));
+    TclNRAddCallback(interp, TclNRCoroutineActivateCallback, corPtr,
+            clientData, NULL, NULL);
+    return TCL_OK;
+}
+
+int
+TclNRYieldToObjCmd(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+    Tcl_Obj *listPtr, *nsObjPtr;
+    Tcl_Namespace *nsPtr = TclGetCurrentNamespace(interp);
+
+    if (objc < 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "command ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    if (!corPtr) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "yieldto can only be called in a coroutine", -1));
+	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ILLEGAL_YIELD", NULL);
+	return TCL_ERROR;
+    }
+
+    if (((Namespace *) nsPtr)->flags & NS_DYING) {
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+		"yieldto called in deleted namespace", -1));
+        Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "YIELDTO_IN_DELETED",
+		NULL);
+        return TCL_ERROR;
+    }
+
+    /*
+     * Add the tailcall in the caller env, then just yield.
+     *
+     * This is essentially code from TclNRTailcallObjCmd
+     */
+
+    listPtr = Tcl_NewListObj(objc, objv);
+    nsObjPtr = Tcl_NewStringObj(nsPtr->fullName, -1);
+    TclListObjSetElement(interp, listPtr, 0, nsObjPtr);
+
+    /*
+     * Add the callback in the caller's env, then instruct TEBC to yield.
+     */
+
+    iPtr->execEnvPtr = corPtr->callerEEPtr;
+    TclSetTailcall(interp, listPtr);
+    iPtr->execEnvPtr = corPtr->eePtr;
+
+    return TclNRYieldObjCmd(INT2PTR(CORO_ACTIVATE_YIELDM), interp, 1, objv);
+}
+
+static int
+RewindCoroutineCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    return Tcl_RestoreInterpState(interp, data[0]);
+}
+
+static int
+RewindCoroutine(
+    CoroutineData *corPtr,
+    int result)
+{
+    Tcl_Interp *interp = corPtr->eePtr->interp;
+    Tcl_InterpState state = Tcl_SaveInterpState(interp, result);
+
+    NRE_ASSERT(COR_IS_SUSPENDED(corPtr));
+    NRE_ASSERT(corPtr->eePtr != NULL);
+    NRE_ASSERT(corPtr->eePtr != iPtr->execEnvPtr);
+
+    corPtr->eePtr->rewind = 1;
+    TclNRAddCallback(interp, RewindCoroutineCallback, state,
+	    NULL, NULL, NULL);
+    return TclNRInterpCoroutine(corPtr, interp, 0, NULL);
+}
+
+static void
+DeleteCoroutine(
+    ClientData clientData)
+{
+    CoroutineData *corPtr = clientData;
+    Tcl_Interp *interp = corPtr->eePtr->interp;
+    NRE_callback *rootPtr = TOP_CB(interp);
+
+    if (COR_IS_SUSPENDED(corPtr)) {
+	TclNRRunCallbacks(interp, RewindCoroutine(corPtr,TCL_OK), rootPtr);
+    }
+}
+
+static int
+NRCoroutineCallerCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    CoroutineData *corPtr = data[0];
+    Command *cmdPtr = corPtr->cmdPtr;
+
+    /*
+     * This is the last callback in the caller execEnv, right before switching
+     * to the coroutine's
+     */
+
+    NRE_ASSERT(iPtr->execEnvPtr == corPtr->callerEEPtr);
+
+    if (!corPtr->eePtr) {
+	/*
+	 * The execEnv was wound down but not deleted for our sake. We finish
+	 * the job here. The caller context has already been restored.
+	 */
+
+	NRE_ASSERT(iPtr->varFramePtr == corPtr->caller.varFramePtr);
+	NRE_ASSERT(iPtr->framePtr == corPtr->caller.framePtr);
+	NRE_ASSERT(iPtr->cmdFramePtr == corPtr->caller.cmdFramePtr);
+	ckfree(corPtr);
+	return result;
+    }
+
+    NRE_ASSERT(COR_IS_SUSPENDED(corPtr));
+    SAVE_CONTEXT(corPtr->running);
+    RESTORE_CONTEXT(corPtr->caller);
+
+    if (cmdPtr->flags & CMD_IS_DELETED) {
+	/*
+	 * The command was deleted while it was running: wind down the
+	 * execEnv, this will do the complete cleanup. RewindCoroutine will
+	 * restore both the caller's context and interp state.
+	 */
+
+	return RewindCoroutine(corPtr, result);
+    }
+
+    return result;
+}
+
+static int
+NRCoroutineExitCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    CoroutineData *corPtr = data[0];
+    Command *cmdPtr = corPtr->cmdPtr;
+
+    /*
+     * This runs at the bottom of the Coroutine's execEnv: it will be executed
+     * when the coroutine returns or is wound down, but not when it yields. It
+     * deletes the coroutine and restores the caller's environment.
+     */
+
+    NRE_ASSERT(interp == corPtr->eePtr->interp);
+    NRE_ASSERT(TOP_CB(interp) == NULL);
+    NRE_ASSERT(iPtr->execEnvPtr == corPtr->eePtr);
+    NRE_ASSERT(!COR_IS_SUSPENDED(corPtr));
+    NRE_ASSERT((corPtr->callerEEPtr->callbackPtr->procPtr == NRCoroutineCallerCallback));
+
+    cmdPtr->deleteProc = NULL;
+    Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
+    TclCleanupCommandMacro(cmdPtr);
+
+    corPtr->eePtr->corPtr = NULL;
+    TclDeleteExecEnv(corPtr->eePtr);
+    corPtr->eePtr = NULL;
+
+    corPtr->stackLevel = NULL;
+
+    /*
+     * #280.
+     * Drop the coroutine-owned copy of the lineLABCPtr hashtable for literal
+     * command arguments in bytecode.
+     */
+
+    Tcl_DeleteHashTable(corPtr->lineLABCPtr);
+    ckfree(corPtr->lineLABCPtr);
+    corPtr->lineLABCPtr = NULL;
+
+    RESTORE_CONTEXT(corPtr->caller);
+    iPtr->execEnvPtr = corPtr->callerEEPtr;
+    iPtr->numLevels++;
+
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNRCoroutineActivateCallback --
+ *
+ *      This is the workhorse for coroutines: it implements both yield and
+ *      resume.
+ *
+ *      It is important that both be implemented in the same callback: the
+ *      detection of the impossibility to suspend due to a busy C-stack relies
+ *      on the precise position of a local variable in the stack. We do not
+ *      want the compiler to play tricks on us, either by moving things around
+ *      or inlining.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclNRCoroutineActivateCallback(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    CoroutineData *corPtr = data[0];
+    int type = PTR2INT(data[1]);
+    int numLevels, unused;
+    int *stackLevel = &unused;
+
+    if (!corPtr->stackLevel) {
+        /*
+         * -- Coroutine is suspended --
+         * Push the callback to restore the caller's context on yield or
+         * return.
+         */
+
+        TclNRAddCallback(interp, NRCoroutineCallerCallback, corPtr,
+                NULL, NULL, NULL);
+
+        /*
+         * Record the stackLevel at which the resume is happening, then swap
+         * the interp's environment to make it suitable to run this coroutine.
+         */
+
+        corPtr->stackLevel = stackLevel;
+        numLevels = corPtr->auxNumLevels;
+        corPtr->auxNumLevels = iPtr->numLevels;
+
+        SAVE_CONTEXT(corPtr->caller);
+        corPtr->callerEEPtr = iPtr->execEnvPtr;
+        RESTORE_CONTEXT(corPtr->running);
+        iPtr->execEnvPtr = corPtr->eePtr;
+        iPtr->numLevels += numLevels;
+    } else {
+        /*
+         * Coroutine is active: yield
+         */
+
+        if (corPtr->stackLevel != stackLevel) {
+            Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                    "cannot yield: C stack busy", -1));
+            Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "CANT_YIELD",
+                    NULL);
+            return TCL_ERROR;
+        }
+
+        if (type == CORO_ACTIVATE_YIELD) {
+            corPtr->nargs = COROUTINE_ARGUMENTS_SINGLE_OPTIONAL;
+        } else if (type == CORO_ACTIVATE_YIELDM) {
+            corPtr->nargs = COROUTINE_ARGUMENTS_ARBITRARY;
+        } else {
+            Tcl_Panic("Yield received an option which is not implemented");
+        }
+
+        corPtr->stackLevel = NULL;
+
+        numLevels = iPtr->numLevels;
+        iPtr->numLevels = corPtr->auxNumLevels;
+        corPtr->auxNumLevels = numLevels - corPtr->auxNumLevels;
+
+        iPtr->execEnvPtr = corPtr->callerEEPtr;
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNREvalList --
+ *
+ *      Callback to invoke command as list, used in order to delayed
+ *	processing of canonical list command in sane environment.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TclNREvalList(
+    ClientData data[],
+    Tcl_Interp *interp,
+    int result)
+{
+    int objc;
+    Tcl_Obj **objv;
+    Tcl_Obj *listPtr = data[0];
+
+    Tcl_IncrRefCount(listPtr);
+
+    TclMarkTailcall(interp);
+    TclNRAddCallback(interp, TclNRReleaseValues, listPtr, NULL, NULL,NULL);
+    TclListObjGetElements(NULL, listPtr, &objc, &objv);
+    return TclNREvalObjv(interp, objc, objv, 0, NULL);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * NRCoroInjectObjCmd --
+ *
+ *      Implementation of [::tcl::unsupported::inject] command.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+NRCoroInjectObjCmd(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    Command *cmdPtr;
+    CoroutineData *corPtr;
+    ExecEnv *savedEEPtr = iPtr->execEnvPtr;
+
+    /*
+     * Usage more or less like tailcall:
+     *   inject coroName cmd ?arg1 arg2 ...?
+     */
+
+    if (objc < 3) {
+	Tcl_WrongNumArgs(interp, 1, objv, "coroName cmd ?arg1 arg2 ...?");
+	return TCL_ERROR;
+    }
+
+    cmdPtr = (Command *) Tcl_GetCommandFromObj(interp, objv[1]);
+    if ((!cmdPtr) || (cmdPtr->nreProc != TclNRInterpCoroutine)) {
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "can only inject a command into a coroutine", -1));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COROUTINE",
+                TclGetString(objv[1]), NULL);
+        return TCL_ERROR;
+    }
+
+    corPtr = cmdPtr->objClientData;
+    if (!COR_IS_SUSPENDED(corPtr)) {
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(
+                "can only inject a command into a suspended coroutine", -1));
+        Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "ACTIVE", NULL);
+        return TCL_ERROR;
+    }
+
+    /*
+     * Add the callback to the coro's execEnv, so that it is the first thing
+     * to happen when the coro is resumed.
+     */
+
+    iPtr->execEnvPtr = corPtr->eePtr;
+    TclNRAddCallback(interp, TclNREvalList, Tcl_NewListObj(objc-2, objv+2),
+	NULL, NULL, NULL);
+    iPtr->execEnvPtr = savedEEPtr;
+
+    return TCL_OK;
+}
+
+int
+TclNRInterpCoroutine(
+    ClientData clientData,
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    CoroutineData *corPtr = clientData;
+
+    if (!COR_IS_SUSPENDED(corPtr)) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "coroutine \"%s\" is already running",
+                Tcl_GetString(objv[0])));
+	Tcl_SetErrorCode(interp, "TCL", "COROUTINE", "BUSY", NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Parse all the arguments to work out what to feed as the result of the
+     * [yield]. TRICKY POINT: objc==0 happens here! It occurs when a coroutine
+     * is deleted!
+     */
+
+    switch (corPtr->nargs) {
+    case COROUTINE_ARGUMENTS_SINGLE_OPTIONAL:
+        if (objc == 2) {
+            Tcl_SetObjResult(interp, objv[1]);
+        } else if (objc > 2) {
+            Tcl_WrongNumArgs(interp, 1, objv, "?arg?");
+            return TCL_ERROR;
+        }
+        break;
+    default:
+        if (corPtr->nargs != objc-1) {
+            Tcl_SetObjResult(interp,
+                    Tcl_NewStringObj("wrong coro nargs; how did we get here? "
+                    "not implemented!", -1));
+            Tcl_SetErrorCode(interp, "TCL", "WRONGARGS", NULL);
+            return TCL_ERROR;
+        }
+        /* fallthrough */
+    case COROUTINE_ARGUMENTS_ARBITRARY:
+        if (objc > 1) {
+            Tcl_SetObjResult(interp, Tcl_NewListObj(objc-1, objv+1));
+        }
+        break;
+    }
+
+    TclNRAddCallback(interp, TclNRCoroutineActivateCallback, corPtr,
+            NULL, NULL, NULL);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNRCoroutineObjCmd --
+ *
+ *      Implementation of [coroutine] command; see documentation for
+ *      description of what this does.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclNRCoroutineObjCmd(
+    ClientData dummy,		/* Not used. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    Command *cmdPtr;
+    CoroutineData *corPtr;
+    const char *fullName, *procName;
+    Namespace *nsPtr, *altNsPtr, *cxtNsPtr;
+    Tcl_DString ds;
+    Namespace *lookupNsPtr = iPtr->varFramePtr->nsPtr;
+
+    if (objc < 3) {
+	Tcl_WrongNumArgs(interp, 1, objv, "name cmd ?arg ...?");
+	return TCL_ERROR;
+    }
+
+    /*
+     * FIXME: this is copy/pasted from Tcl_ProcObjCommand. Should have
+     * something in tclUtil.c to find the FQ name.
+     */
+
+    fullName = TclGetString(objv[1]);
+    TclGetNamespaceForQualName(interp, fullName, NULL, 0,
+	    &nsPtr, &altNsPtr, &cxtNsPtr, &procName);
+
+    if (nsPtr == NULL) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\": unknown namespace",
+                fullName));
+        Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", NULL);
+	return TCL_ERROR;
+    }
+    if (procName == NULL) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\": bad procedure name",
+                fullName));
+        Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", fullName, NULL);
+	return TCL_ERROR;
+    }
+    if ((nsPtr != iPtr->globalNsPtr)
+	    && (procName != NULL) && (procName[0] == ':')) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+                "can't create procedure \"%s\" in non-global namespace with"
+                " name starting with \":\"", procName));
+        Tcl_SetErrorCode(interp, "TCL", "VALUE", "COMMAND", procName, NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * We ARE creating the coroutine command: allocate the corresponding
+     * struct and create the corresponding command.
+     */
+
+    corPtr = ckalloc(sizeof(CoroutineData));
+
+    Tcl_DStringInit(&ds);
+    if (nsPtr != iPtr->globalNsPtr) {
+	Tcl_DStringAppend(&ds, nsPtr->fullName, -1);
+	TclDStringAppendLiteral(&ds, "::");
+    }
+    Tcl_DStringAppend(&ds, procName, -1);
+
+    cmdPtr = (Command *) Tcl_NRCreateCommand(interp, Tcl_DStringValue(&ds),
+	    /*objProc*/ NULL, TclNRInterpCoroutine, corPtr, DeleteCoroutine);
+    Tcl_DStringFree(&ds);
+
+    corPtr->cmdPtr = cmdPtr;
+    cmdPtr->refCount++;
+
+    /*
+     * #280.
+     * Provide the new coroutine with its own copy of the lineLABCPtr
+     * hashtable for literal command arguments in bytecode. Note that that
+     * CFWordBC chains are not duplicated, only the entrypoints to them. This
+     * means that in the presence of coroutines each chain is potentially a
+     * tree. Like the chain -> tree conversion of the CmdFrame stack.
+     */
+
+    {
+	Tcl_HashSearch hSearch;
+	Tcl_HashEntry *hePtr;
+
+	corPtr->lineLABCPtr = ckalloc(sizeof(Tcl_HashTable));
+	Tcl_InitHashTable(corPtr->lineLABCPtr, TCL_ONE_WORD_KEYS);
+
+	for (hePtr = Tcl_FirstHashEntry(iPtr->lineLABCPtr,&hSearch);
+		hePtr; hePtr = Tcl_NextHashEntry(&hSearch)) {
+	    int isNew;
+	    Tcl_HashEntry *newPtr =
+		    Tcl_CreateHashEntry(corPtr->lineLABCPtr,
+		    Tcl_GetHashKey(iPtr->lineLABCPtr, hePtr),
+		    &isNew);
+
+	    Tcl_SetHashValue(newPtr, Tcl_GetHashValue(hePtr));
+	}
+    }
+
+    /*
+     * Create the base context.
+     */
+
+    corPtr->running.framePtr = iPtr->rootFramePtr;
+    corPtr->running.varFramePtr = iPtr->rootFramePtr;
+    corPtr->running.cmdFramePtr = NULL;
+    corPtr->running.lineLABCPtr = corPtr->lineLABCPtr;
+    corPtr->stackLevel = NULL;
+    corPtr->auxNumLevels = 0;
+
+    /*
+     * Create the coro's execEnv, switch to it to push the exit and coro
+     * command callbacks, then switch back.
+     */
+
+    corPtr->eePtr = TclCreateExecEnv(interp, CORO_STACK_INITIAL_SIZE);
+    corPtr->callerEEPtr = iPtr->execEnvPtr;
+    corPtr->eePtr->corPtr = corPtr;
+
+    SAVE_CONTEXT(corPtr->caller);
+    corPtr->callerEEPtr = iPtr->execEnvPtr;
+    RESTORE_CONTEXT(corPtr->running);
+    iPtr->execEnvPtr = corPtr->eePtr;
+
+    TclNRAddCallback(interp, NRCoroutineExitCallback, corPtr,
+	    NULL, NULL, NULL);
+
+    /* insure that the command is looked up in the correct namespace */
+    iPtr->lookupNsPtr = lookupNsPtr;
+    Tcl_NREvalObj(interp, Tcl_NewListObj(objc-2, objv+2), 0);
+    iPtr->numLevels--;
+
+    SAVE_CONTEXT(corPtr->running);
+    RESTORE_CONTEXT(corPtr->caller);
+    iPtr->execEnvPtr = corPtr->callerEEPtr;
+
+    /*
+     * Now just resume the coroutine.
+     */
+
+    TclNRAddCallback(interp, TclNRCoroutineActivateCallback, corPtr,
+            NULL, NULL, NULL);
+    return TCL_OK;
+}
+
+/*
+ * This is used in the [info] ensemble
+ */
+
+int
+TclInfoCoroutineCmd(
+    ClientData dummy,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+
+    if (objc != 1) {
+	Tcl_WrongNumArgs(interp, 1, objv, NULL);
+	return TCL_ERROR;
+    }
+
+    if (corPtr && !(corPtr->cmdPtr->flags & CMD_IS_DELETED)) {
+	Tcl_Obj *namePtr;
+
+	TclNewObj(namePtr);
+	Tcl_GetCommandFullName(interp, (Tcl_Command) corPtr->cmdPtr, namePtr);
+	Tcl_SetObjResult(interp, namePtr);
+    }
+    return TCL_OK;
+}
+
+#undef iPtr
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ */