Otherware/Otherware_1_SB_Development.iso/mac/developm/language/harvest.cpt/Harvest C/Tcl 6.2/tclBasic.c

C/C++ Source or Header | 1992-04-13 | 27.2 KB | 1,062 lines

#ifdef macintosh
#    pragma segment tclBasic
#endif

/*
 * tclBasic.c --
 *
 *    Contains the basic facilities for TCL command interpretation,
 *    including interpreter creation and deletion, command creation
 *    and deletion, and command parsing and execution.
 *
 * Copyright 1987-1991 Regents of the University of California
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies.  The University of California
 * makes no representations about the suitability of this
 * software for any purpose.  It is provided "as is" without
 * express or implied warranty.
 */

#ifndef lint
static char rcsid[] = "$Header: /user6/ouster/tcl/RCS/tclBasic.c,v 1.128 91/10/31 16:41:13 ouster Exp $ SPRITE (Berkeley)";
#endif

#include "tclInt.h"

/*
 * The following structure defines all of the commands in the Tcl core,
 * and the C procedures that execute them.
 */

typedef struct {
    char *name;            /* Name of command. */
    Tcl_CmdProc *proc;        /* Procedure that executes command. */
    } CmdInfo;

/*
 * Built-in commands, and the procedures associated with them:
 */

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

    {"append",        Tcl_AppendCmd},
    {"array",        Tcl_ArrayCmd},
    {"break",        Tcl_BreakCmd},
    {"case",        Tcl_CaseCmd},
    {"catch",        Tcl_CatchCmd},
    {"concat",        Tcl_ConcatCmd},
    {"continue",    Tcl_ContinueCmd},
    {"error",        Tcl_ErrorCmd},
    {"eval",        Tcl_EvalCmd},
    {"expr",        Tcl_ExprCmd},
    {"for",            Tcl_ForCmd},
    {"foreach",        Tcl_ForeachCmd},
    {"format",        Tcl_FormatCmd},
    {"global",        Tcl_GlobalCmd},
    {"if",            Tcl_IfCmd},
    {"incr",        Tcl_IncrCmd},
    {"info",        Tcl_InfoCmd},
    {"join",        Tcl_JoinCmd},
    {"lappend",        Tcl_LappendCmd},
    {"lindex",        Tcl_LindexCmd},
    {"linsert",        Tcl_LinsertCmd},
    {"list",        Tcl_ListCmd},
    {"llength",        Tcl_LlengthCmd},
    {"lrange",        Tcl_LrangeCmd},
    {"lreplace",    Tcl_LreplaceCmd},
    {"lsearch",        Tcl_LsearchCmd},
    {"lsort",        Tcl_LsortCmd},
    {"proc",        Tcl_ProcCmd},
    {"regexp",        Tcl_RegexpCmd},
    {"regsub",        Tcl_RegsubCmd},
    {"rename",        Tcl_RenameCmd},
    {"return",        Tcl_ReturnCmd},
    {"scan",        Tcl_ScanCmd},
    {"set",            Tcl_SetCmd},
    {"split",        Tcl_SplitCmd},
    {"string",        Tcl_StringCmd},
    {"trace",        Tcl_TraceCmd},
    {"unset",        Tcl_UnsetCmd},
    {"uplevel",        Tcl_UplevelCmd},
    {"upvar",        Tcl_UpvarCmd},
    {"while",        Tcl_WhileCmd},

    /*
     * Commands in the UNIX core:
     */

#ifndef TCL_GENERIC_ONLY
#ifndef macintosh
    {"cd",            Tcl_CdCmd},
    {"exec",        Tcl_ExecCmd},
    {"pwd",            Tcl_PwdCmd},
#endif
    {"close",        Tcl_CloseCmd},
    {"eof",            Tcl_EofCmd},
    {"exit",        Tcl_ExitCmd},
    {"file",        Tcl_FileCmd},
    {"flush",        Tcl_FlushCmd},
    {"gets",        Tcl_GetsCmd},
    {"glob",        Tcl_GlobCmd},
    {"open",        Tcl_OpenCmd},
    {"puts",        Tcl_PutsCmd},
    {"read",        Tcl_ReadCmd},
    {"seek",        Tcl_SeekCmd},
    {"source",        Tcl_SourceCmd},
    {"tell",        Tcl_TellCmd},
    {"time",        Tcl_TimeCmd},
#endif /* TCL_GENERIC_ONLY */
    {NULL,        (Tcl_CmdProc *) NULL}
};

/*
 *----------------------------------------------------------------------
 *
 * 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 procedures like Tcl_CreateCmd, Tcl_Eval, or
 *    Tcl_DeleteInterp.
 *
 * Side effects:
 *    The command interpreter is initialized with an empty variable
 *    table and the built-in commands.
 *
 *----------------------------------------------------------------------
 */

Tcl_Interp *
Tcl_CreateInterp()
{
    register Interp *iPtr;
    register Command *cmdPtr;
    register CmdInfo *cmdInfoPtr;
    int i;

    iPtr = (Interp *) ckalloc(sizeof(Interp));
    iPtr->result = iPtr->resultSpace;
    iPtr->freeProc = 0;
    iPtr->errorLine = 0;
    Tcl_InitHashTable(&iPtr->commandTable, TCL_STRING_KEYS);
    Tcl_InitHashTable(&iPtr->globalTable, TCL_STRING_KEYS);
    iPtr->numLevels = 0;
    iPtr->framePtr = NULL;
    iPtr->varFramePtr = NULL;
    iPtr->activeTracePtr = NULL;
    iPtr->numEvents = 0;
    iPtr->events = NULL;
    iPtr->curEvent = 0;
    iPtr->curEventNum = 0;
    iPtr->revPtr = NULL;
    iPtr->historyFirst = NULL;
    iPtr->revDisables = 1;
    iPtr->evalFirst = iPtr->evalLast = NULL;
    iPtr->appendResult = NULL;
    iPtr->appendAvl = 0;
    iPtr->appendUsed = 0;
    iPtr->numFiles = 0;
    iPtr->filePtrArray = NULL;
    for (i = 0; i < NUM_REGEXPS; i++) {
        iPtr->patterns[i] = NULL;
        iPtr->regexps[i] = NULL;
        }
    iPtr->cmdCount = 0;
    iPtr->noEval = 0;
    iPtr->scriptFile = NULL;
    iPtr->flags = 0;
    iPtr->tracePtr = NULL;
    iPtr->resultSpace[0] = 0;

    /*
     * Create the built-in 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).
     */

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

    hPtr = Tcl_CreateHashEntry(&iPtr->commandTable,
        cmdInfoPtr->name, &_new);
    if (_new) {
        cmdPtr = (Command *) ckalloc(sizeof(Command));
        cmdPtr->proc = cmdInfoPtr->proc;
        cmdPtr->clientData = (ClientData) NULL;
        cmdPtr->deleteProc = NULL;
        Tcl_SetHashValue(hPtr, cmdPtr);
    }
    }

#ifndef TCL_GENERIC_ONLY
    TclSetupEnv((Tcl_Interp *) iPtr);
#endif

    return (Tcl_Interp *) iPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteInterp --
 *
 *    Delete an interpreter and free up all of the resources associated
 *    with it.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The interpreter is destroyed.  The caller should never again
 *    use the interp token.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_DeleteInterp(interp)
    Tcl_Interp *interp;        /* Token for command interpreter (returned
                 * by a previous call to Tcl_CreateInterp). */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    register Command *cmdPtr;
    int i;

    /*
     * If the interpreter is in use, delay the deletion until later.
     */

    iPtr->flags |= DELETED;
    if (iPtr->numLevels != 0) {
    return;
    }

    /*
     * Free up any remaining resources associated with the
     * interpreter.
     */

    for (hPtr = Tcl_FirstHashEntry(&iPtr->commandTable, &search);
        hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
    cmdPtr = (Command *) Tcl_GetHashValue(hPtr);
    if (cmdPtr->deleteProc != NULL) {
        (*cmdPtr->deleteProc)(cmdPtr->clientData);
    }
    ckfree((char *) cmdPtr);
    }
    Tcl_DeleteHashTable(&iPtr->commandTable);
    TclDeleteVars(iPtr, &iPtr->globalTable);
    if (iPtr->events != NULL) {
    int i;

    for (i = 0; i < iPtr->numEvents; i++) {
        ckfree(iPtr->events[i].command);
    }
    ckfree((char *) iPtr->events);
    }
    while (iPtr->revPtr != NULL) {
    HistoryRev *nextPtr = iPtr->revPtr->nextPtr;

    ckfree((char *) iPtr->revPtr);
    iPtr->revPtr = nextPtr;
    }
    if (iPtr->appendResult != NULL) {
    ckfree(iPtr->appendResult);
    }
#ifndef TCL_GENERIC_ONLY
    if (iPtr->numFiles > 0) {
    for (i = 0; i < iPtr->numFiles; i++) {
        OpenFile *filePtr;

        filePtr = iPtr->filePtrArray[i];
        if (filePtr == NULL) {
        continue;
        }
        if (i >= 3) {
        fclose(filePtr->f);
        if (filePtr->f2 != NULL) {
            fclose(filePtr->f2);
        }
        if (filePtr->numPids > 0) {
            Tcl_DetachPids(filePtr->numPids, filePtr->pidPtr);
            ckfree((char *) filePtr->pidPtr);
        }
        }
        ckfree((char *) filePtr);
    }
    ckfree((char *) iPtr->filePtrArray);
    }
#endif
    for (i = 0; i < NUM_REGEXPS; i++) {
    if (iPtr->patterns[i] == NULL) {
        break;
    }
    ckfree(iPtr->patterns[i]);
    ckfree((char *) iPtr->regexps[i]);
    }
    while (iPtr->tracePtr != NULL) {
    Trace *nextPtr = iPtr->tracePtr->nextPtr;

    ckfree((char *) iPtr->tracePtr);
    iPtr->tracePtr = nextPtr;
    }
    ckfree((char *) iPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateCommand --
 *
 *    Define a _new command in a command table.
 *
 * Results:
 *    None.
 *
 * 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.  When the command
 *    is deleted from the table, deleteProc will be called.  See the
 *    manual entry for details on the calling sequence.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_CreateCommand(interp, cmdName, proc, clientData, deleteProc)
    Tcl_Interp *interp;        /* Token for command interpreter (returned
                 * by a previous call to Tcl_CreateInterp). */
    char *cmdName;        /* Name of command. */
    Tcl_CmdProc *proc;        /* Command procedure to associate with
                 * cmdName. */
    ClientData clientData;    /* Arbitrary one-word value to pass to proc. */
    Tcl_CmdDeleteProc *deleteProc;
                /* If not NULL, gives a procedure to call when
                 * this command is deleted. */
{
    Interp *iPtr = (Interp *) interp;
    register Command *cmdPtr;
    Tcl_HashEntry *hPtr;
    int _new;

    hPtr = Tcl_CreateHashEntry(&iPtr->commandTable, cmdName, &_new);
    if (!_new) {
    /*
     * Command already exists:  delete the old one.
     */

    cmdPtr = (Command *) Tcl_GetHashValue(hPtr);
    if (cmdPtr->deleteProc != NULL) {
        (*cmdPtr->deleteProc)(cmdPtr->clientData);
    }
    } else {
    cmdPtr = (Command *) ckalloc(sizeof(Command));
    Tcl_SetHashValue(hPtr, cmdPtr);
    }
    cmdPtr->proc = proc;
    cmdPtr->clientData = clientData;
    cmdPtr->deleteProc = deleteProc;
}

/*
 *----------------------------------------------------------------------
 *
 * 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(interp, cmdName)
    Tcl_Interp *interp;        /* Token for command interpreter (returned
                 * by a previous call to Tcl_CreateInterp). */
    char *cmdName;        /* Name of command to remove. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    Command *cmdPtr;

    hPtr = Tcl_FindHashEntry(&iPtr->commandTable, cmdName);
    if (hPtr == NULL) {
    return -1;
    }
    cmdPtr = (Command *) Tcl_GetHashValue(hPtr);
    if (cmdPtr->deleteProc != NULL) {
    (*cmdPtr->deleteProc)(cmdPtr->clientData);
    }
    ckfree((char *) cmdPtr);
    Tcl_DeleteHashEntry(hPtr);
    return 0;
}

/*
 *-----------------------------------------------------------------
 *
 * Tcl_Eval --
 *
 *    Parse and execute a command in the Tcl language.
 *
 * Results:
 *    The return value is one of the return codes defined in tcl.hd
 *    (such as TCL_OK), and interp->result contains a string value
 *    to supplement the return code.  The value of interp->result
 *    will persist only until the next call to Tcl_Eval:  copy it or
 *    lose it! *TermPtr is filled in with the character just after
 *    the last one that was part of the command (usually a NULL
 *    character or a closing bracket).
 *
 * Side effects:
 *    Almost certainly;  depends on the command.
 *
 *-----------------------------------------------------------------
 */

int
Tcl_Eval(interp, cmd, flags, termPtr)
    Tcl_Interp *interp;        /* Token for command interpreter (returned
                 * by a previous call to Tcl_CreateInterp). */
    char *cmd;            /* Pointer to TCL command to interpret. */
    int flags;            /* OR-ed combination of flags like
                 * TCL_BRACKET_TERM and TCL_RECORD_BOUNDS. */
    char **termPtr;        /* If non-NULL, fill in the address it points
                 * to with the address of the char. just after
                 * the last one that was part of cmd.  See
                 * the man page for details on this. */
{
    /*
     * The storage immediately below is used to generate a copy
     * of the command, after all argument substitutions.  Pv will
     * contain the argv values passed to the command procedure.
     */

#   define NUM_CHARS 200
    char copyStorage[NUM_CHARS];
    ParseValue pv;
    char *oldBuffer;

    /*
     * This procedure generates an (argv, argc) array for the command,
     * It starts out with stack-allocated space but uses dynamically-
     * allocated storage to increase it if needed.
     */

#   define NUM_ARGS 10
    char *(argStorage[NUM_ARGS]);
    char **argv = argStorage;
    int argc;
    int argSize = NUM_ARGS;

    register char *src;            /* Points to current character
                     * in cmd. */
    char termChar;            /* Return when this character is found
                     * (either ']' or '\0').  Zero means
                     * that newlines terminate commands. */
    int result;                /* Return value. */
    register Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    Command *cmdPtr;
    char *dummy;            /* Make termPtr point here if it was
                     * originally NULL. */
    char *cmdStart;            /* Points to first non-blank char. in
                     * command (used in calling trace
                     * procedures). */
    char *ellipsis = "";        /* Used in setting errorInfo variable;
                     * set to "..." to indicate that not
                     * all of offending command is included
                     * in errorInfo.  "" means that the
                     * command is all there. */
    register Trace *tracePtr;

    /*
     * Initialize the result to an empty string and clear out any
     * error information.  This makes sure that we return an empty
     * result if there are no commands in the command string.
     */

    Tcl_FreeResult((Tcl_Interp *) iPtr);
    iPtr->result = iPtr->resultSpace;
    iPtr->resultSpace[0] = 0;
    result = TCL_OK;

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

    iPtr->numLevels++;
    if (iPtr->numLevels > MAX_NESTING_DEPTH) {
    iPtr->result =  "too many nested calls to Tcl_Eval (infinite loop?)";
    return TCL_ERROR;
    }

    /*
     * Initialize the area in which command copies will be assembled.
     */

    pv.buffer = copyStorage;
    pv.end = copyStorage + NUM_CHARS - 1;
    pv.expandProc = TclExpandParseValue;
    pv.clientData = (ClientData) NULL;

    src = cmd;
    if (flags & TCL_BRACKET_TERM) {
    termChar = ']';
    } else {
    termChar = 0;
    }
    if (termPtr == NULL) {
    termPtr = &dummy;
    }
    *termPtr = src;
    cmdStart = src;

    /*
     * There can be many sub-commands (separated by semi-colons or
     * newlines) in one command string.  This outer loop iterates over
     * individual commands.
     */

    while (*src != termChar) {
    iPtr->flags &= ~(ERR_IN_PROGRESS | ERROR_CODE_SET);

    /*
     * Skim off leading white space and semi-colons, and skip
     * comments.
     */

    while (1) {
        register char c = *src;

        if ((CHAR_TYPE(c) != TCL_SPACE) && (c != ';') && (c != '\n')) {
        break;
        }
        src += 1;
    }
    if (*src == '#') {
        for (src++; *src != 0; src++) {
        if (*src == '\n') {
            src++;
            break;
        }
        }
        continue;
    }
    cmdStart = src;

    /*
     * Parse the words of the command, generating the argc and
     * argv for the command procedure.  May have to call
     * TclParseWords several times, expanding the argv array
     * between calls.
     */

    pv.next = oldBuffer = pv.buffer;
    argc = 0;
    while (1) {
        int newArgs, maxArgs;
        char **newArgv;
        int i;

        /*
         * Note:  the "- 2" below guarantees that we won't use the
         * last two argv slots here.  One is for a NULL pointer to
         * mark the end of the list, and the other is to leave room
         * for inserting the command name "unknown" as the first
         * argument (see below).
         */

        maxArgs = argSize - argc - 2;
        result = TclParseWords((Tcl_Interp *) iPtr, src, flags,
            maxArgs, termPtr, &newArgs, &argv[argc], &pv);
        src = *termPtr;
        if (result != TCL_OK) {
        ellipsis = "...";
        goto done;
        }

        /*
         * Careful!  Buffer space may have gotten reallocated while
         * parsing words.  If this happened, be sure to update all
         * of the older argv pointers to refer to the _new space.
         */

        if (oldBuffer != pv.buffer) {
        int i;

        for (i = 0; i < argc; i++) {
            argv[i] = pv.buffer + (argv[i] - oldBuffer);
        }
        oldBuffer = pv.buffer;
        }
        argc += newArgs;
        if (newArgs < maxArgs) {
        argv[argc] = (char *) NULL;
        break;
        }

        /*
         * Args didn't all fit in the current array.  Make it bigger.
         */

        argSize *= 2;
        newArgv = (char **)
            ckalloc((unsigned) argSize * sizeof(char *));
        for (i = 0; i < argc; i++) {
        newArgv[i] = argv[i];
        }
        if (argv != argStorage) {
        ckfree((char *) argv);
        }
        argv = newArgv;
    }

    /*
     * If this is an empty command (or if we're just parsing
     * commands without evaluating them), then just skip to the
     * next command.
     */

    if ((argc == 0) || iPtr->noEval) {
        continue;
    }
    argv[argc] = NULL;

    /*
     * Save information for the history module, if needed.
     */

    if (flags & TCL_RECORD_BOUNDS) {
        iPtr->evalFirst = cmdStart;
        iPtr->evalLast = src-1;
    }

    /*
     * Find the procedure to execute this command.  If there isn't
     * one, then see if there is a command "unknown".  If so,
     * invoke it instead, passing it the words of the original
     * command as arguments.
     */

    hPtr = Tcl_FindHashEntry(&iPtr->commandTable, argv[0]);
    if (hPtr == NULL) {
        int i;

        hPtr = Tcl_FindHashEntry(&iPtr->commandTable, "unknown");
        if (hPtr == NULL) {
        Tcl_ResetResult(interp);
        Tcl_AppendResult(interp, "invalid command name: \"",
            argv[0], "\"", (char *) NULL);
        result = TCL_ERROR;
        goto done;
        }
        for (i = argc; i >= 0; i--) {
        argv[i+1] = argv[i];
        }
        argv[0] = "unknown";
        argc++;
    }
    cmdPtr = (Command *) Tcl_GetHashValue(hPtr);

    /*
     * Call trace procedures, if any.
     */

    for (tracePtr = iPtr->tracePtr; tracePtr != NULL;
        tracePtr = tracePtr->nextPtr) {
        char saved;

        if (tracePtr->level < iPtr->numLevels) {
        continue;
        }
        saved = *src;
        *src = 0;
        (*tracePtr->proc)(tracePtr->clientData, interp, iPtr->numLevels,
            cmdStart, cmdPtr->proc, cmdPtr->clientData, argc, argv);
        *src = saved;
    }

    /*
     * At long last, invoke the command procedure.  Reset the
     * result to its default empty value first (it could have
     * gotten changed by earlier commands in the same command
     * string).
     */

    iPtr->cmdCount++;
    Tcl_FreeResult(iPtr);
    iPtr->result = iPtr->resultSpace;
    iPtr->resultSpace[0] = 0;
    result = (*cmdPtr->proc)(cmdPtr->clientData, interp, argc, argv);
    if (result != TCL_OK) {
        break;
    }
    }

    /*
     * Free up any extra resources that were allocated.
     */

    done:
    if (pv.buffer != copyStorage) {
    ckfree((char *) pv.buffer);
    }
    if (argv != argStorage) {
    ckfree((char *) argv);
    }
    iPtr->numLevels--;
    if (iPtr->numLevels == 0) {
    if (result == TCL_RETURN) {
        result = TCL_OK;
    }
    if ((result != TCL_OK) && (result != TCL_ERROR)) {
        Tcl_ResetResult(interp);
        if (result == TCL_BREAK) {
        iPtr->result = "invoked \"break\" outside of a loop";
        } else if (result == TCL_CONTINUE) {
        iPtr->result = "invoked \"continue\" outside of a loop";
        } else {
        iPtr->result = iPtr->resultSpace;
        sprintf(iPtr->resultSpace, "command returned bad code: %d",
            result);
        }
        result = TCL_ERROR;
    }
    if (iPtr->flags & DELETED) {
        Tcl_DeleteInterp(interp);
    }
    }

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

    if ((result == TCL_ERROR) && !(iPtr->flags & ERR_ALREADY_LOGGED)) {
    int numChars;
    register char *p;

    /*
     * Compute the line number where the error occurred.
     */

    iPtr->errorLine = 1;
    for (p = cmd; p != cmdStart; p++) {
        if (*p == '\n') {
        iPtr->errorLine++;
        }
    }
    for ( ; isspace(*p) || (*p == ';'); p++) {
        if (*p == '\n') {
        iPtr->errorLine++;
        }
    }

    /*
     * Figure out how much of the command to print in the error
     * message (up to a certain number of characters, or up to
     * the first _new-line).
     */

    numChars = src - cmdStart;
    if (numChars > (NUM_CHARS-50)) {
        numChars = NUM_CHARS-50;
        ellipsis = " ...";
    }

    if (!(iPtr->flags & ERR_IN_PROGRESS)) {
        sprintf(copyStorage, "\n    while executing\n\"%.*s%s\"",
            numChars, cmdStart, ellipsis);
    } else {
        sprintf(copyStorage, "\n    invoked from within\n\"%.*s%s\"",
            numChars, cmdStart, ellipsis);
    }
    Tcl_AddErrorInfo(interp, copyStorage);
    iPtr->flags &= ~ERR_ALREADY_LOGGED;
    } else {
    iPtr->flags &= ~ERR_ALREADY_LOGGED;
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateTrace --
 *
 *    Arrange for a procedure to be called to trace command execution.
 *
 * Results:
 *    The return value is a token for the trace, which may be passed
 *    to Tcl_DeleteTrace to eliminate the trace.
 *
 * Side effects:
 *    From now on, proc will be called just before a command procedure
 *    is called to execute a Tcl command.  Calls to proc will have the
 *    following form:
 *
 *    void
 *    proc(clientData, interp, level, command, cmdProc, cmdClientData,
 *        argc, argv)
 *        ClientData clientData;
 *        Tcl_Interp *interp;
 *        int level;
 *        char *command;
 *        int (*cmdProc)();
 *        ClientData cmdClientData;
 *        int argc;
 *        char **argv;
 *    {
 *    }
 *
 *    The clientData and interp arguments to proc will be the same
 *    as the corresponding arguments to this procedure.  Level gives
 *    the nesting level of command interpretation for this interpreter
 *    (0 corresponds to top level).  Command gives the ASCII text of
 *    the raw command, cmdProc and cmdClientData give the procedure that
 *    will be called to process the command and the ClientData value it
 *    will receive, and argc and argv give the arguments to the
 *    command, after any argument parsing and substitution.  Proc
 *    does not return a value.
 *
 *----------------------------------------------------------------------
 */

Tcl_Trace
Tcl_CreateTrace(interp, level, proc, clientData)
    Tcl_Interp *interp;        /* Interpreter in which to create the trace. */
    int level;            /* Only call proc for commands at nesting level
                 * <= level (1 => top level). */
    Tcl_CmdTraceProc *proc;    /* Procedure to call before executing each
                 * command. */
    ClientData clientData;    /* Arbitrary one-word value to pass to proc. */
{
    register Trace *tracePtr;
    register Interp *iPtr = (Interp *) interp;

    tracePtr = (Trace *) ckalloc(sizeof(Trace));
    tracePtr->level = level;
    tracePtr->proc = proc;
    tracePtr->clientData = clientData;
    tracePtr->nextPtr = iPtr->tracePtr;
    iPtr->tracePtr = tracePtr;

    return (Tcl_Trace) tracePtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteTrace --
 *
 *    Remove a trace.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    From now on there will be no more calls to the procedure given
 *    in trace.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_DeleteTrace(interp, trace)
    Tcl_Interp *interp;        /* Interpreter that contains trace. */
    Tcl_Trace trace;        /* Token for trace (returned previously by
                 * Tcl_CreateTrace). */
{
    register Interp *iPtr = (Interp *) interp;
    register Trace *tracePtr = (Trace *) trace;
    register Trace *tracePtr2;

    if (iPtr->tracePtr == tracePtr) {
    iPtr->tracePtr = tracePtr->nextPtr;
    ckfree((char *) tracePtr);
    } else {
    for (tracePtr2 = iPtr->tracePtr; tracePtr2 != NULL;
        tracePtr2 = tracePtr2->nextPtr) {
        if (tracePtr2->nextPtr == tracePtr) {
        tracePtr2->nextPtr = tracePtr->nextPtr;
        ckfree((char *) tracePtr);
        return;
        }
    }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AddErrorInfo --
 *
 *    Add information to a message being accumulated that describes
 *    the current error.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    The contents of message are added to the "errorInfo" variable.
 *    If Tcl_Eval has been called since the current value of errorInfo
 *    was set, errorInfo is cleared before adding the _new message.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AddErrorInfo(interp, message)
    Tcl_Interp *interp;        /* Interpreter to which error information
                 * pertains. */
    char *message;        /* Message to record. */
{
    register Interp *iPtr = (Interp *) interp;

    /*
     * If an error is already being logged, then the _new errorInfo
     * is the concatenation of the old info and the _new message.
     * If this is the first piece of info for the error, then the
     * _new errorInfo is the concatenation of the message in
     * interp->result and the _new message.
     */

    if (!(iPtr->flags & ERR_IN_PROGRESS)) {
    Tcl_SetVar2(interp, "errorInfo", (char *) NULL, interp->result,
        TCL_GLOBAL_ONLY);
    iPtr->flags |= ERR_IN_PROGRESS;

    /*
     * If the errorCode variable wasn't set by the code that generated
     * the error, set it to "NONE".
     */

    if (!(iPtr->flags & ERROR_CODE_SET)) {
        (void) Tcl_SetVar2(interp, "errorCode", (char *) NULL, "NONE",
            TCL_GLOBAL_ONLY);
    }
    }
    Tcl_SetVar2(interp, "errorInfo", (char *) NULL, message,
        TCL_GLOBAL_ONLY|TCL_APPEND_VALUE);
}

/*
 *----------------------------------------------------------------------
 *
 * 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.
 *
 *----------------------------------------------------------------------
 */
    /* VARARGS2 */ /* ARGSUSED */

#ifdef macintosh

Tcl_VarEval(Tcl_Interp *interp,...)
{

#else

int
#ifndef lint
Tcl_VarEval(va_alist)
#else
Tcl_VarEval(interp, p, va_alist)
    Tcl_Interp *interp;        /* Interpreter in which to execute command. */
    char *p;            /* One or more strings to concatenate,
                 * terminated with a NULL string. */
#endif
    va_dcl;
{
    Tcl_Interp *interp;

#endif

    va_list argList;
#        define FIXED_SIZE 200
    char fixedSpace[FIXED_SIZE+1];
    int spaceAvl, spaceUsed, length;
    char *string, *cmd;
    int result;

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

#ifdef macintosh
    va_start(argList, interp);
#else
    va_start(argList);
#endif

#ifndef macintosh
    interp = va_arg(argList, Tcl_Interp *);
#endif

    spaceAvl = FIXED_SIZE;
    spaceUsed = 0;
    cmd = fixedSpace;
    while (1) {
    string = va_arg(argList, char *);
    if (string == NULL) {
        break;
    }
    length = strlen(string);
    if ((spaceUsed + length) > spaceAvl) {
        char *_new;

        spaceAvl = spaceUsed + length;
        spaceAvl += spaceAvl/2;
        _new = ckalloc((unsigned) spaceAvl);
        memcpy((VOID *) _new, (VOID *) cmd, spaceUsed);
        if (cmd != fixedSpace) {
        ckfree(cmd);
        }
        cmd = _new;
    }
    strcpy(cmd + spaceUsed, string);
    spaceUsed += length;
    }
    va_end(argList);
    cmd[spaceUsed] = '\0';

    result = Tcl_Eval(interp, cmd, 0, (char **) NULL);
    if (cmd != fixedSpace) {
    ckfree(cmd);
    }
    return result;
}