source: HiSusy/trunk/Delphes/Delphes-3.0.9/external/tcl/tclParse.c @ 5

/* 
 * tclParse.c --
 *
 *      This file contains a collection of procedures that are used
 *      to parse Tcl commands or parts of commands (like quoted
 *      strings or nested sub-commands).
 *
 * Copyright (c) 1987-1993 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclParse.c,v 1.1 2008-06-04 13:58:09 demin Exp $
 */

#include "tclInt.h"
#include "tclPort.h"

/*
 * Function prototypes for procedures local to this file:
 */

static char *   QuoteEnd _ANSI_ARGS_((char *string, char *lastChar,
                    int term));
static char *   ScriptEnd _ANSI_ARGS_((char *p, char *lastChar,
                    int nested));
static char *   VarNameEnd _ANSI_ARGS_((char *string,  char *lastChar));

/*
 *--------------------------------------------------------------
 *
 * TclParseQuotes --
 *
 *      This procedure parses a double-quoted string such as a
 *      quoted Tcl command argument or a quoted value in a Tcl
 *      expression.  This procedure is also used to parse array
 *      element names within parentheses, or anything else that
 *      needs all the substitutions that happen in quotes.
 *
 * Results:
 *      The return value is a standard Tcl result, which is
 *      TCL_OK unless there was an error while parsing the
 *      quoted string.  If an error occurs then interp->result
 *      contains a standard error message.  *TermPtr is filled
 *      in with the address of the character just after the
 *      last one successfully processed;  this is usually the
 *      character just after the matching close-quote.  The
 *      fully-substituted contents of the quotes are stored in
 *      standard fashion in *pvPtr, null-terminated with
 *      pvPtr->next pointing to the terminating null character.
 *
 * Side effects:
 *      The buffer space in pvPtr may be enlarged by calling its
 *      expandProc.
 *
 *--------------------------------------------------------------
 */

int
TclParseQuotes(interp, string, termChar, flags, termPtr, pvPtr)
    Tcl_Interp *interp;         /* Interpreter to use for nested command
                                 * evaluations and error messages. */
    char *string;               /* Character just after opening double-
                                 * quote. */
    int termChar;               /* Character that terminates "quoted" string
                                 * (usually double-quote, but sometimes
                                 * right-paren or something else). */
    int flags;                  /* Flags to pass to nested Tcl_Eval calls. */
    char **termPtr;             /* Store address of terminating character
                                 * here. */
    ParseValue *pvPtr;          /* Information about where to place
                                 * fully-substituted result of parse. */
{
    register char *src, *dst, c;
    char *lastChar = string + strlen(string);

    src = string;
    dst = pvPtr->next;

    while (1) {
        if (dst == pvPtr->end) {
            /*
             * Target buffer space is about to run out.  Make more space.
             */

            pvPtr->next = dst;
            (*pvPtr->expandProc)(pvPtr, 1);
            dst = pvPtr->next;
        }

        c = *src;
        src++;
        if (c == termChar) {
            *dst = '\0';
            pvPtr->next = dst;
            *termPtr = src;
            return TCL_OK;
        } else if (CHAR_TYPE(src-1, lastChar) == TCL_NORMAL) {
            copy:
            *dst = c;
            dst++;
            continue;
        } else if (c == '$') {
            int length;
            char *value;

            value = Tcl_ParseVar(interp, src-1, termPtr);
            if (value == NULL) {
                return TCL_ERROR;
            }
            src = *termPtr;
            length = strlen(value);
            if ((pvPtr->end - dst) <= length) {
                pvPtr->next = dst;
                (*pvPtr->expandProc)(pvPtr, length);
                dst = pvPtr->next;
            }
            strcpy(dst, value);
            dst += length;
            continue;
        } else if (c == '[') {
            int result;

            pvPtr->next = dst;
            result = TclParseNestedCmd(interp, src, flags, termPtr, pvPtr);
            if (result != TCL_OK) {
                return result;
            }
            src = *termPtr;
            dst = pvPtr->next;
            continue;
        } else if (c == '\\') {
            int numRead;

            src--;
            *dst = Tcl_Backslash(src, &numRead);
            dst++;
            src += numRead;
            continue;
        } else if (c == '\0') {
            char buf[30];
            
            Tcl_ResetResult(interp);
            sprintf(buf, "missing %c", termChar);
            Tcl_SetResult(interp, buf, TCL_VOLATILE);
            *termPtr = string-1;
            return TCL_ERROR;
        } else {
            goto copy;
        }
    }
}

/*
 *--------------------------------------------------------------
 *
 * TclParseNestedCmd --
 *
 *      This procedure parses a nested Tcl command between
 *      brackets, returning the result of the command.
 *
 * Results:
 *      The return value is a standard Tcl result, which is
 *      TCL_OK unless there was an error while executing the
 *      nested command.  If an error occurs then interp->result
 *      contains a standard error message.  *TermPtr is filled
 *      in with the address of the character just after the
 *      last one processed;  this is usually the character just
 *      after the matching close-bracket, or the null character
 *      at the end of the string if the close-bracket was missing
 *      (a missing close bracket is an error).  The result returned
 *      by the command is stored in standard fashion in *pvPtr,
 *      null-terminated, with pvPtr->next pointing to the null
 *      character.
 *
 * Side effects:
 *      The storage space at *pvPtr may be expanded.
 *
 *--------------------------------------------------------------
 */

int
TclParseNestedCmd(interp, string, flags, termPtr, pvPtr)
    Tcl_Interp *interp;         /* Interpreter to use for nested command
                                 * evaluations and error messages. */
    char *string;               /* Character just after opening bracket. */
    int flags;                  /* Flags to pass to nested Tcl_Eval. */
    char **termPtr;             /* Store address of terminating character
                                 * here. */
    register ParseValue *pvPtr; /* Information about where to place
                                 * result of command. */
{
    int result, length, shortfall;
    Interp *iPtr = (Interp *) interp;

    iPtr->evalFlags = flags | TCL_BRACKET_TERM;
    result = Tcl_Eval(interp, string);
    *termPtr = (string + iPtr->termOffset);
    if (result != TCL_OK) {
        /*
         * The increment below results in slightly cleaner message in
         * the errorInfo variable (the close-bracket will appear).
         */

        if (**termPtr == ']') {
            *termPtr += 1;
        }
        return result;
    }
    (*termPtr) += 1;
    length = strlen(iPtr->result);
    shortfall = length + 1 - (pvPtr->end - pvPtr->next);
    if (shortfall > 0) {
        (*pvPtr->expandProc)(pvPtr, shortfall);
    }
    strcpy(pvPtr->next, iPtr->result);
    pvPtr->next += length;
    
    Tcl_FreeResult(interp);
    iPtr->result = iPtr->resultSpace;
    iPtr->resultSpace[0] = '\0';
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * TclParseBraces --
 *
 *      This procedure scans the information between matching
 *      curly braces.
 *
 * Results:
 *      The return value is a standard Tcl result, which is
 *      TCL_OK unless there was an error while parsing string.
 *      If an error occurs then interp->result contains a
 *      standard error message.  *TermPtr is filled
 *      in with the address of the character just after the
 *      last one successfully processed;  this is usually the
 *      character just after the matching close-brace.  The
 *      information between curly braces is stored in standard
 *      fashion in *pvPtr, null-terminated with pvPtr->next
 *      pointing to the terminating null character.
 *
 * Side effects:
 *      The storage space at *pvPtr may be expanded.
 *
 *--------------------------------------------------------------
 */

int
TclParseBraces(interp, string, termPtr, pvPtr)
    Tcl_Interp *interp;         /* Interpreter to use for nested command
                                 * evaluations and error messages. */
    char *string;               /* Character just after opening bracket. */
    char **termPtr;             /* Store address of terminating character
                                 * here. */
    register ParseValue *pvPtr; /* Information about where to place
                                 * result of command. */
{
    int level;
    register char *src, *dst, *end;
    register char c;
    char *lastChar = string + strlen(string);

    src = string;
    dst = pvPtr->next;
    end = pvPtr->end;
    level = 1;

    /*
     * Copy the characters one at a time to the result area, stopping
     * when the matching close-brace is found.
     */

    while (1) {
        c = *src;
        src++;
        if (dst == end) {
            pvPtr->next = dst;
            (*pvPtr->expandProc)(pvPtr, 20);
            dst = pvPtr->next;
            end = pvPtr->end;
        }
        *dst = c;
        dst++;
        if (CHAR_TYPE(src-1, lastChar) == TCL_NORMAL) {
            continue;
        } else if (c == '{') {
            level++;
        } else if (c == '}') {
            level--;
            if (level == 0) {
                dst--;                  /* Don't copy the last close brace. */
                break;
            }
        } else if (c == '\\') {
            int count;

            /*
             * Must always squish out backslash-newlines, even when in
             * braces.  This is needed so that this sequence can appear
             * anywhere in a command, such as the middle of an expression.
             */

            if (*src == '\n') {
                dst[-1] = Tcl_Backslash(src-1, &count);
                src += count - 1;
            } else {
                (void) Tcl_Backslash(src-1, &count);
                while (count > 1) {
                    if (dst == end) {
                        pvPtr->next = dst;
                        (*pvPtr->expandProc)(pvPtr, 20);
                        dst = pvPtr->next;
                        end = pvPtr->end;
                    }
                    *dst = *src;
                    dst++;
                    src++;
                    count--;
                }
            }
        } else if (c == '\0') {
            Tcl_SetResult(interp, "missing close-brace", TCL_STATIC);
            *termPtr = string-1;
            return TCL_ERROR;
        }
    }

    *dst = '\0';
    pvPtr->next = dst;
    *termPtr = src;
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * TclExpandParseValue --
 *
 *      This procedure is commonly used as the value of the
 *      expandProc in a ParseValue.  It uses malloc to allocate
 *      more space for the result of a parse.
 *
 * Results:
 *      The buffer space in *pvPtr is reallocated to something
 *      larger, and if pvPtr->clientData is non-zero the old
 *      buffer is freed.  Information is copied from the old
 *      buffer to the new one.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

void
TclExpandParseValue(pvPtr, needed)
    register ParseValue *pvPtr;         /* Information about buffer that
                                         * must be expanded.  If the clientData
                                         * in the structure is non-zero, it
                                         * means that the current buffer is
                                         * dynamically allocated. */
    int needed;                         /* Minimum amount of additional space
                                         * to allocate. */
{
    int newSpace;
    char *new;

    /*
     * Either double the size of the buffer or add enough new space
     * to meet the demand, whichever produces a larger new buffer.
     */

    newSpace = (pvPtr->end - pvPtr->buffer) + 1;
    if (newSpace < needed) {
        newSpace += needed;
    } else {
        newSpace += newSpace;
    }
    new = (char *) ckalloc((unsigned) newSpace);

    /*
     * Copy from old buffer to new, free old buffer if needed, and
     * mark new buffer as malloc-ed.
     */

    memcpy((VOID *) new, (VOID *) pvPtr->buffer,
            (size_t) (pvPtr->next - pvPtr->buffer));
    pvPtr->next = new + (pvPtr->next - pvPtr->buffer);
    if (pvPtr->clientData != 0) {
        ckfree(pvPtr->buffer);
    }
    pvPtr->buffer = new;
    pvPtr->end = new + newSpace - 1;
    pvPtr->clientData = (ClientData) 1;
}

/*
 *----------------------------------------------------------------------
 *
 * TclWordEnd --
 *
 *      Given a pointer into a Tcl command, find the end of the next
 *      word of the command.
 *
 * Results:
 *      The return value is a pointer to the last character that's part
 *      of the word pointed to by "start".  If the word doesn't end
 *      properly within the string then the return value is the address
 *      of the null character at the end of the string.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

char *
TclWordEnd(start, lastChar, nested, semiPtr)
    char *start;                /* Beginning of a word of a Tcl command. */
    char *lastChar;             /* Terminating character in string. */
    int nested;                 /* Zero means this is a top-level command.
                                 * One means this is a nested command (close
                                 * bracket is a word terminator). */
    int *semiPtr;               /* Set to 1 if word ends with a command-
                                 * terminating semi-colon, zero otherwise.
                                 * If NULL then ignored. */
{
    register char *p;
    int count;

    if (semiPtr != NULL) {
        *semiPtr = 0;
    }

    /*
     * Skip leading white space (backslash-newline must be treated like
     * white-space, except that it better not be the last thing in the
     * command).
     */

    for (p = start; ; p++) {
        if (isspace(UCHAR(*p))) {
            continue;
        }
        if ((p[0] == '\\') && (p[1] == '\n')) {
            if (p+2 == lastChar) {
                return p+2;
            }
            continue;
        }
        break;
    }

    /*
     * Handle words beginning with a double-quote or a brace.
     */

    if (*p == '"') {
        p = QuoteEnd(p+1, lastChar, '"');
        if (p == lastChar) {
            return p;
        }
        p++;
    } else if (*p == '{') {
        int braces = 1;
        while (braces != 0) {
            p++;
            while (*p == '\\') {
                (void) Tcl_Backslash(p, &count);
                p += count;
            }
            if (*p == '}') {
                braces--;
            } else if (*p == '{') {
                braces++;
            } else if (p == lastChar) {
                return p;
            }
        }
        p++;
    }

    /*
     * Handle words that don't start with a brace or double-quote.
     * This code is also invoked if the word starts with a brace or
     * double-quote and there is garbage after the closing brace or
     * quote.  This is an error as far as Tcl_Eval is concerned, but
     * for here the garbage is treated as part of the word.
     */

    while (1) {
        if (*p == '[') {
            p = ScriptEnd(p+1, lastChar, 1);
            if (p == lastChar) {
                return p;
            }
            p++;
        } else if (*p == '\\') {
            if (p[1] == '\n') {
                /*
                 * Backslash-newline:  it maps to a space character
                 * that is a word separator, so the word ends just before
                 * the backslash.
                 */

                return p-1;
            }
            (void) Tcl_Backslash(p, &count);
            p += count;
        } else if (*p == '$') {
            p = VarNameEnd(p, lastChar);
            if (p == lastChar) {
                return p;
            }
            p++;
        } else if (*p == ';') {
            /*
             * Include the semi-colon in the word that is returned.
             */

            if (semiPtr != NULL) {
                *semiPtr = 1;
            }
            return p;
        } else if (isspace(UCHAR(*p))) {
            return p-1;
        } else if ((*p == ']') && nested) {
            return p-1;
        } else if (p == lastChar) {
            if (nested) {
                /*
                 * Nested commands can't end because of the end of the
                 * string.
                 */
                return p;
            }
            return p-1;
        } else {
            p++;
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * QuoteEnd --
 *
 *      Given a pointer to a string that obeys the parsing conventions
 *      for quoted things in Tcl, find the end of that quoted thing.
 *      The actual thing may be a quoted argument or a parenthesized
 *      index name.
 *
 * Results:
 *      The return value is a pointer to the last character that is
 *      part of the quoted string (i.e the character that's equal to
 *      term).  If the quoted string doesn't terminate properly then
 *      the return value is a pointer to the null character at the
 *      end of the string.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
QuoteEnd(string, lastChar, term)
    char *string;               /* Pointer to character just after opening
                                 * "quote". */
    char *lastChar;             /* Terminating character in string. */
    int term;                   /* This character will terminate the
                                 * quoted string (e.g. '"' or ')'). */
{
    register char *p = string;
    int count;

    while (*p != term) {
        if (*p == '\\') {
            (void) Tcl_Backslash(p, &count);
            p += count;
        } else if (*p == '[') {
            for (p++; *p != ']'; p++) {
                p = TclWordEnd(p, lastChar, 1, (int *) NULL);
                if (*p == 0) {
                    return p;
                }
            }
            p++;
        } else if (*p == '$') {
            p = VarNameEnd(p, lastChar);
            if (*p == 0) {
                return p;
            }
            p++;
        } else if (p == lastChar) {
            return p;
        } else {
            p++;
        }
    }
    return p-1;
}

/*
 *----------------------------------------------------------------------
 *
 * VarNameEnd --
 *
 *      Given a pointer to a variable reference using $-notation, find
 *      the end of the variable name spec.
 *
 * Results:
 *      The return value is a pointer to the last character that
 *      is part of the variable name.  If the variable name doesn't
 *      terminate properly then the return value is a pointer to the
 *      null character at the end of the string.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
VarNameEnd(string, lastChar)
    char *string;               /* Pointer to dollar-sign character. */
    char *lastChar;             /* Terminating character in string. */
{
    register char *p = string+1;

    if (*p == '{') {
        for (p++; (*p != '}') && (p != lastChar); p++) {
            /* Empty loop body. */
        }
        return p;
    }
    while (isalnum(UCHAR(*p)) || (*p == '_')) {
        p++;
    }
    if ((*p == '(') && (p != string+1)) {
        return QuoteEnd(p+1, lastChar, ')');
    }
    return p-1;
}


/*
 *----------------------------------------------------------------------
 *
 * ScriptEnd --
 *
 *      Given a pointer to the beginning of a Tcl script, find the end of
 *      the script.
 *
 * Results:
 *      The return value is a pointer to the last character that's part
 *      of the script pointed to by "p".  If the command doesn't end
 *      properly within the string then the return value is the address
 *      of the null character at the end of the string.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static char *
ScriptEnd(p, lastChar, nested)
    char *p;                    /* Script to check. */
    char *lastChar;             /* Terminating character in string. */
    int nested;                 /* Zero means this is a top-level command.
                                 * One means this is a nested command (the
                                 * last character of the script must be
                                 * an unquoted ]). */
{
    int commentOK = 1;
    int length;

    while (1) {
        while (isspace(UCHAR(*p))) {
            if (*p == '\n') {
                commentOK = 1;
            }
            p++;
        }
        if ((*p == '#') && commentOK) {
            do {
                if (*p == '\\') {
                    /*
                     * If the script ends with backslash-newline, then
                     * this command isn't complete.
                     */

                    if ((p[1] == '\n') && (p+2 == lastChar)) {
                        return p+2;
                    }
                    Tcl_Backslash(p, &length);
                    p += length;
                } else {
                    p++;
                }
            } while ((p != lastChar) && (*p != '\n'));
            continue;
        }
        p = TclWordEnd(p, lastChar, nested, &commentOK);
        if (p == lastChar) {
            return p;
        }
        p++;
        if (nested) {
            if (*p == ']') {
                return p;
            }
        } else {
            if (p == lastChar) {
                return p-1;
            }
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ParseVar --
 *
 *      Given a string starting with a $ sign, parse off a variable
 *      name and return its value.
 *
 * Results:
 *      The return value is the contents of the variable given by
 *      the leading characters of string.  If termPtr isn't NULL,
 *      *termPtr gets filled in with the address of the character
 *      just after the last one in the variable specifier.  If the
 *      variable doesn't exist, then the return value is NULL and
 *      an error message will be left in interp->result.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

char *
Tcl_ParseVar(interp, string, termPtr)
    Tcl_Interp *interp;                 /* Context for looking up variable. */
    register char *string;              /* String containing variable name.
                                         * First character must be "$". */
    char **termPtr;                     /* If non-NULL, points to word to fill
                                         * in with character just after last
                                         * one in the variable specifier. */

{
    char *name1, *name1End, c, *result;
    register char *name2;
#define NUM_CHARS 200
    char copyStorage[NUM_CHARS];
    ParseValue pv;

    /*
     * There are three cases:
     * 1. The $ sign is followed by an open curly brace.  Then the variable
     *    name is everything up to the next close curly brace, and the
     *    variable is a scalar variable.
     * 2. The $ sign is not followed by an open curly brace.  Then the
     *    variable name is everything up to the next character that isn't
     *    a letter, digit, or underscore, or a "::" namespace separator.
     *    If the following character is an open parenthesis, then the
     *    information between parentheses is the array element name, which
     *    can include any of the substitutions permissible between quotes.
     * 3. The $ sign is followed by something that isn't a letter, digit,
     *    underscore, or a "::" namespace separator: in this case,
     *    there is no variable name, and "$" is returned.
     */

    name2 = NULL;
    string++;
    if (*string == '{') {
        string++;
        name1 = string;
        while (*string != '}') {
            if (*string == 0) {
                Tcl_SetResult(interp, "missing close-brace for variable name",
                        TCL_STATIC);
                if (termPtr != 0) {
                    *termPtr = string;
                }
                return NULL;
            }
            string++;
        }
        name1End = string;
        string++;
    } else {
        name1 = string;
        while (isalnum(UCHAR(*string)) || (*string == '_')
                || (*string == ':')) {
            if (*string == ':') {
                if (*(string+1) == ':') {
                    string += 2;  /* skip over the initial :: */
                    while (*string == ':') {
                        string++; /* skip over a subsequent : */
                    }
                } else {
                    break;        /* : by itself */
                }
            } else {
                string++;
            }
        }
        if (string == name1) {
            if (termPtr != 0) {
                *termPtr = string;
            }
            return "$";
        }
        name1End = string;
        if (*string == '(') {
            char *end;

            /*
             * Perform substitutions on the array element name, just as
             * is done for quotes.
             */

            pv.buffer = pv.next = copyStorage;
            pv.end = copyStorage + NUM_CHARS - 1;
            pv.expandProc = TclExpandParseValue;
            pv.clientData = (ClientData) NULL;
            if (TclParseQuotes(interp, string+1, ')', 0, &end, &pv)
                    != TCL_OK) {
                char msg[200];
                int length;

                length = string-name1;
                if (length > 100) {
                    length = 100;
                }
                sprintf(msg, "\n    (parsing index for array \"%.*s\")",
                        length, name1);
                Tcl_AddErrorInfo(interp, msg);
                result = NULL;
                name2 = pv.buffer;
                if (termPtr != 0) {
                    *termPtr = end;
                }
                goto done;
            }
            Tcl_ResetResult(interp);
            string = end;
            name2 = pv.buffer;
        }
    }
    if (termPtr != 0) {
        *termPtr = string;
    }

    c = *name1End;
    *name1End = 0;
    result = Tcl_GetVar2(interp, name1, name2, TCL_LEAVE_ERR_MSG);
    *name1End = c;

    done:
    if ((name2 != NULL) && (pv.buffer != copyStorage)) {
        ckfree(pv.buffer);
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CommandComplete --
 *
 *      Given a partial or complete Tcl command, this procedure
 *      determines whether the command is complete in the sense
 *      of having matched braces and quotes and brackets.
 *
 * Results:
 *      1 is returned if the command is complete, 0 otherwise.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_CommandComplete(cmd)
    char *cmd;                  /* Command to check. */
{
    char *p;

    if (*cmd == 0) {
        return 1;
    }
    p = ScriptEnd(cmd, cmd+strlen(cmd), 0);
    return (*p != 0);
}

/*
 *----------------------------------------------------------------------
 *
 * TclObjCommandComplete --
 *
 *      Given a partial or complete Tcl command in a Tcl object, this
 *      procedure determines whether the command is complete in the sense of
 *      having matched braces and quotes and brackets.
 *
 * Results:
 *      1 is returned if the command is complete, 0 otherwise.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
TclObjCommandComplete(cmdPtr)
    Tcl_Obj *cmdPtr;                    /* Points to object holding command
                                         * to check. */
{
    char *cmd, *p;
    int length;

    cmd = Tcl_GetStringFromObj(cmdPtr, &length);
    if (length == 0) {
        return 1;
    }
    p = ScriptEnd(cmd, cmd+length, /*nested*/ 0);
    return (*p != 0);
}