gecko/js/src/jsprf.cpp

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
** Portable safe sprintf code.
**
** Author: Kipp E.B. Hickman
*/
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "jsprf.h"
#include "jsutil.h"
#include "jspubtd.h"
#include "jsstr.h"

using namespace js;

/*
** Note: on some platforms va_list is defined as an array,
** and requires array notation.
*/
#ifdef HAVE_VA_COPY
#define VARARGS_ASSIGN(foo, bar)        VA_COPY(foo,bar)
#elif defined(HAVE_VA_LIST_AS_ARRAY)
#define VARARGS_ASSIGN(foo, bar)        foo[0] = bar[0]
#else
#define VARARGS_ASSIGN(foo, bar)        (foo) = (bar)
#endif

/*
** WARNING: This code may *NOT* call JS_LOG (because JS_LOG calls it)
*/

/*
** XXX This needs to be internationalized!
*/

typedef struct SprintfStateStr SprintfState;

struct SprintfStateStr {
    int (*stuff)(SprintfState *ss, const char *sp, uint32_t len);

    char *base;
    char *cur;
    uint32_t maxlen;

    int (*func)(void *arg, const char *sp, uint32_t len);
    void *arg;
};

/*
** Numbered Arguement State
*/
struct NumArgState{
    int     type;               /* type of the current ap                    */
    va_list ap;                 /* point to the corresponding position on ap */
};

#define NAS_DEFAULT_NUM 20  /* default number of NumberedArgumentState array */


#define TYPE_INT16      0
#define TYPE_UINT16     1
#define TYPE_INTN       2
#define TYPE_UINTN      3
#define TYPE_INT32      4
#define TYPE_UINT32     5
#define TYPE_INT64      6
#define TYPE_UINT64     7
#define TYPE_STRING     8
#define TYPE_DOUBLE     9
#define TYPE_INTSTR     10
#define TYPE_WSTRING    11
#define TYPE_UNKNOWN    20

#define FLAG_LEFT       0x1
#define FLAG_SIGNED     0x2
#define FLAG_SPACED     0x4
#define FLAG_ZEROS      0x8
#define FLAG_NEG        0x10

/*
** Fill into the buffer using the data in src
*/
static int fill2(SprintfState *ss, const char *src, int srclen, int width,
                int flags)
{
    char space = ' ';
    int rv;

    width -= srclen;
    if ((width > 0) && ((flags & FLAG_LEFT) == 0)) {    /* Right adjusting */
        if (flags & FLAG_ZEROS) {
            space = '0';
        }
        while (--width >= 0) {
            rv = (*ss->stuff)(ss, &space, 1);
            if (rv < 0) {
                return rv;
            }
        }
    }

    /* Copy out the source data */
    rv = (*ss->stuff)(ss, src, uint32_t(srclen));
    if (rv < 0) {
        return rv;
    }

    if ((width > 0) && ((flags & FLAG_LEFT) != 0)) {    /* Left adjusting */
        while (--width >= 0) {
            rv = (*ss->stuff)(ss, &space, 1);
            if (rv < 0) {
                return rv;
            }
        }
    }
    return 0;
}

/*
** Fill a number. The order is: optional-sign zero-filling conversion-digits
*/
static int fill_n(SprintfState *ss, const char *src, int srclen, int width,
                  int prec, int type, int flags)
{
    int zerowidth = 0;
    int precwidth = 0;
    int signwidth = 0;
    int leftspaces = 0;
    int rightspaces = 0;
    int cvtwidth;
    int rv;
    char sign;

    if ((type & 1) == 0) {
        if (flags & FLAG_NEG) {
            sign = '-';
            signwidth = 1;
        } else if (flags & FLAG_SIGNED) {
            sign = '+';
            signwidth = 1;
        } else if (flags & FLAG_SPACED) {
            sign = ' ';
            signwidth = 1;
        }
    }
    cvtwidth = signwidth + srclen;

    if (prec > 0) {
        if (prec > srclen) {
            precwidth = prec - srclen;          /* Need zero filling */
            cvtwidth += precwidth;
        }
    }

    if ((flags & FLAG_ZEROS) && (prec < 0)) {
        if (width > cvtwidth) {
            zerowidth = width - cvtwidth;       /* Zero filling */
            cvtwidth += zerowidth;
        }
    }

    if (flags & FLAG_LEFT) {
        if (width > cvtwidth) {
            /* Space filling on the right (i.e. left adjusting) */
            rightspaces = width - cvtwidth;
        }
    } else {
        if (width > cvtwidth) {
            /* Space filling on the left (i.e. right adjusting) */
            leftspaces = width - cvtwidth;
        }
    }
    while (--leftspaces >= 0) {
        rv = (*ss->stuff)(ss, " ", 1);
        if (rv < 0) {
            return rv;
        }
    }
    if (signwidth) {
        rv = (*ss->stuff)(ss, &sign, 1);
        if (rv < 0) {
            return rv;
        }
    }
    while (--precwidth >= 0) {
        rv = (*ss->stuff)(ss, "0", 1);
        if (rv < 0) {
            return rv;
        }
    }
    while (--zerowidth >= 0) {
        rv = (*ss->stuff)(ss, "0", 1);
        if (rv < 0) {
            return rv;
        }
    }
    rv = (*ss->stuff)(ss, src, uint32_t(srclen));
    if (rv < 0) {
        return rv;
    }
    while (--rightspaces >= 0) {
        rv = (*ss->stuff)(ss, " ", 1);
        if (rv < 0) {
            return rv;
        }
    }
    return 0;
}

/*
** Convert a long into its printable form
*/
static int cvt_l(SprintfState *ss, long num, int width, int prec, int radix,
                 int type, int flags, const char *hexp)
{
    char cvtbuf[100];
    char *cvt;
    int digits;

    /* according to the man page this needs to happen */
    if ((prec == 0) && (num == 0)) {
        return 0;
    }

    /*
    ** Converting decimal is a little tricky. In the unsigned case we
    ** need to stop when we hit 10 digits. In the signed case, we can
    ** stop when the number is zero.
    */
    cvt = cvtbuf + sizeof(cvtbuf);
    digits = 0;
    while (num) {
        int digit = (((unsigned long)num) % radix) & 0xF;
        *--cvt = hexp[digit];
        digits++;
        num = (long)(((unsigned long)num) / radix);
    }
    if (digits == 0) {
        *--cvt = '0';
        digits++;
    }

    /*
    ** Now that we have the number converted without its sign, deal with
    ** the sign and zero padding.
    */
    return fill_n(ss, cvt, digits, width, prec, type, flags);
}

/*
** Convert a 64-bit integer into its printable form
*/
static int cvt_ll(SprintfState *ss, int64_t num, int width, int prec, int radix,
                  int type, int flags, const char *hexp)
{
    /* according to the man page this needs to happen */
    if (prec == 0 && num == 0) {
        return 0;
    }

    /*
    ** Converting decimal is a little tricky. In the unsigned case we
    ** need to stop when we hit 10 digits. In the signed case, we can
    ** stop when the number is zero.
    */
    int64_t rad = int64_t(radix);
    char cvtbuf[100];
    char *cvt = cvtbuf + sizeof(cvtbuf);
    int digits = 0;
    while (num != 0) {
        int64_t quot = uint64_t(num) / rad;
        int64_t rem = uint64_t(num) % rad;
        int32_t digit = int32_t(rem);
        *--cvt = hexp[digit & 0xf];
        digits++;
        num = quot;
    }
    if (digits == 0) {
        *--cvt = '0';
        digits++;
    }

    /*
    ** Now that we have the number converted without its sign, deal with
    ** the sign and zero padding.
    */
    return fill_n(ss, cvt, digits, width, prec, type, flags);
}

/*
** Convert a double precision floating point number into its printable
** form.
**
** XXX stop using sprintf to convert floating point
*/
static int cvt_f(SprintfState *ss, double d, const char *fmt0, const char *fmt1)
{
    char fin[20];
    char fout[300];
    int amount = fmt1 - fmt0;

    JS_ASSERT((amount > 0) && (amount < (int)sizeof(fin)));
    if (amount >= (int)sizeof(fin)) {
        /* Totally bogus % command to sprintf. Just ignore it */
        return 0;
    }
    js_memcpy(fin, fmt0, (size_t)amount);
    fin[amount] = 0;

    /* Convert floating point using the native sprintf code */
#ifdef DEBUG
    {
        const char *p = fin;
        while (*p) {
            JS_ASSERT(*p != 'L');
            p++;
        }
    }
#endif
    sprintf(fout, fin, d);

    /*
    ** This assert will catch overflow's of fout, when building with
    ** debugging on. At least this way we can track down the evil piece
    ** of calling code and fix it!
    */
    JS_ASSERT(strlen(fout) < sizeof(fout));

    return (*ss->stuff)(ss, fout, strlen(fout));
}

/*
** Convert a string into its printable form.  "width" is the output
** width. "prec" is the maximum number of characters of "s" to output,
** where -1 means until NUL.
*/
static int cvt_s(SprintfState *ss, const char *s, int width, int prec,
                 int flags)
{
    int slen;

    if (prec == 0)
        return 0;

    /* Limit string length by precision value */
    slen = s ? strlen(s) : 6;
    if (prec > 0) {
        if (prec < slen) {
            slen = prec;
        }
    }

    /* and away we go */
    return fill2(ss, s ? s : "(null)", slen, width, flags);
}

static int cvt_ws(SprintfState *ss, const jschar *ws, int width, int prec,
                  int flags)
{
    int result;
    /*
     * Supply NULL as the JSContext; errors are not reported,
     * and malloc() is used to allocate the buffer buffer.
     */
    if (ws) {
        int slen = js_strlen(ws);
        char *s = DeflateString(NULL, ws, slen);
        if (!s)
            return -1; /* JSStuffFunc error indicator. */
        result = cvt_s(ss, s, width, prec, flags);
        js_free(s);
    } else {
        result = cvt_s(ss, NULL, width, prec, flags);
    }
    return result;
}

/*
** BuildArgArray stands for Numbered Argument list Sprintf
** for example,
**      fmp = "%4$i, %2$d, %3s, %1d";
** the number must start from 1, and no gap among them
*/

static struct NumArgState* BuildArgArray( const char *fmt, va_list ap, int* rv, struct NumArgState* nasArray )
{
    int number = 0, cn = 0, i;
    const char *p;
    char c;
    struct NumArgState *nas;


    /*
    **  first pass:
    **  detemine how many legal % I have got, then allocate space
    */

    p = fmt;
    *rv = 0;
    i = 0;
    while( ( c = *p++ ) != 0 ){
        if( c != '%' )
            continue;
        if( ( c = *p++ ) == '%' )       /* skip %% case */
            continue;

        while( c != 0 ){
            if( c > '9' || c < '0' ){
                if( c == '$' ){         /* numbered argument csae */
                    if( i > 0 ){
                        *rv = -1;
                        return NULL;
                    }
                    number++;
                } else {                /* non-numbered argument case */
                    if( number > 0 ){
                        *rv = -1;
                        return NULL;
                    }
                    i = 1;
                }
                break;
            }

            c = *p++;
        }
    }

    if( number == 0 ){
        return NULL;
    }


    if( number > NAS_DEFAULT_NUM ){
        nas = (struct NumArgState*)malloc( number * sizeof( struct NumArgState ) );
        if( !nas ){
            *rv = -1;
            return NULL;
        }
    } else {
        nas = nasArray;
    }

    for( i = 0; i < number; i++ ){
        nas[i].type = TYPE_UNKNOWN;
    }


    /*
    ** second pass:
    ** set nas[].type
    */

    p = fmt;
    while( ( c = *p++ ) != 0 ){
        if( c != '%' )  continue;
            c = *p++;
        if( c == '%' )  continue;

        cn = 0;
        while( c && c != '$' ){     /* should improve error check later */
            cn = cn*10 + c - '0';
            c = *p++;
        }

        if( !c || cn < 1 || cn > number ){
            *rv = -1;
            break;
        }

        /* nas[cn] starts from 0, and make sure nas[cn].type is not assigned */
        cn--;
        if( nas[cn].type != TYPE_UNKNOWN )
            continue;

        c = *p++;

        /* width */
        if (c == '*') {
            /* not supported feature, for the argument is not numbered */
            *rv = -1;
            break;
        }

        while ((c >= '0') && (c <= '9')) {
            c = *p++;
        }

        /* precision */
        if (c == '.') {
            c = *p++;
            if (c == '*') {
                /* not supported feature, for the argument is not numbered */
                *rv = -1;
                break;
            }

            while ((c >= '0') && (c <= '9')) {
                c = *p++;
            }
        }

        /* size */
        nas[cn].type = TYPE_INTN;
        if (c == 'h') {
            nas[cn].type = TYPE_INT16;
            c = *p++;
        } else if (c == 'L') {
            /* XXX not quite sure here */
            nas[cn].type = TYPE_INT64;
            c = *p++;
        } else if (c == 'l') {
            nas[cn].type = TYPE_INT32;
            c = *p++;
            if (c == 'l') {
                nas[cn].type = TYPE_INT64;
                c = *p++;
            }
        }

        /* format */
        switch (c) {
        case 'd':
        case 'c':
        case 'i':
        case 'o':
        case 'u':
        case 'x':
        case 'X':
            break;

        case 'e':
        case 'f':
        case 'g':
            nas[ cn ].type = TYPE_DOUBLE;
            break;

        case 'p':
            /* XXX should use cpp */
            if (sizeof(void *) == sizeof(int32_t)) {
                nas[ cn ].type = TYPE_UINT32;
            } else if (sizeof(void *) == sizeof(int64_t)) {
                nas[ cn ].type = TYPE_UINT64;
            } else if (sizeof(void *) == sizeof(int)) {
                nas[ cn ].type = TYPE_UINTN;
            } else {
                nas[ cn ].type = TYPE_UNKNOWN;
            }
            break;

        case 'C':
        case 'S':
        case 'E':
        case 'G':
            /* XXX not supported I suppose */
            JS_ASSERT(0);
            nas[ cn ].type = TYPE_UNKNOWN;
            break;

        case 's':
            nas[ cn ].type = (nas[ cn ].type == TYPE_UINT16) ? TYPE_WSTRING : TYPE_STRING;
            break;

        case 'n':
            nas[ cn ].type = TYPE_INTSTR;
            break;

        default:
            JS_ASSERT(0);
            nas[ cn ].type = TYPE_UNKNOWN;
            break;
        }

        /* get a legal para. */
        if( nas[ cn ].type == TYPE_UNKNOWN ){
            *rv = -1;
            break;
        }
    }


    /*
    ** third pass
    ** fill the nas[cn].ap
    */

    if( *rv < 0 ){
        if( nas != nasArray )
            js_free( nas );
        return NULL;
    }

    cn = 0;
    while( cn < number ){
        if( nas[cn].type == TYPE_UNKNOWN ){
            cn++;
            continue;
        }

        VARARGS_ASSIGN(nas[cn].ap, ap);

        switch( nas[cn].type ){
        case TYPE_INT16:
        case TYPE_UINT16:
        case TYPE_INTN:
        case TYPE_UINTN:                (void)va_arg( ap, int );             break;

        case TYPE_INT32:                (void)va_arg( ap, int32_t );            break;

        case TYPE_UINT32:       (void)va_arg( ap, uint32_t );   break;

        case TYPE_INT64:        (void)va_arg( ap, int64_t );            break;

        case TYPE_UINT64:       (void)va_arg( ap, uint64_t );           break;

        case TYPE_STRING:       (void)va_arg( ap, char* );              break;

        case TYPE_WSTRING:      (void)va_arg( ap, jschar* );            break;

        case TYPE_INTSTR:       (void)va_arg( ap, int* );            break;

        case TYPE_DOUBLE:       (void)va_arg( ap, double );             break;

        default:
            if( nas != nasArray )
                js_free( nas );
            *rv = -1;
            return NULL;
        }

        cn++;
    }


    return nas;
}

/*
** The workhorse sprintf code.
*/
static int dosprintf(SprintfState *ss, const char *fmt, va_list ap)
{
    char c;
    int flags, width, prec, radix, type;
    union {
        char ch;
        jschar wch;
        int i;
        long l;
        int64_t ll;
        double d;
        const char *s;
        const jschar* ws;
        int *ip;
    } u;
    const char *fmt0;
    static const char hex[] = "0123456789abcdef";
    static const char HEX[] = "0123456789ABCDEF";
    const char *hexp;
    int rv, i;
    struct NumArgState *nas = NULL;
    struct NumArgState nasArray[ NAS_DEFAULT_NUM ];
    char pattern[20];
    const char *dolPt = NULL;  /* in "%4$.2f", dolPt will poiont to . */
    uint8_t utf8buf[6];
    int utf8len;

    /*
    ** build an argument array, IF the fmt is numbered argument
    ** list style, to contain the Numbered Argument list pointers
    */

    nas = BuildArgArray( fmt, ap, &rv, nasArray );
    if( rv < 0 ){
        /* the fmt contains error Numbered Argument format, jliu@netscape.com */
        JS_ASSERT(0);
        return rv;
    }

    while ((c = *fmt++) != 0) {
        if (c != '%') {
            rv = (*ss->stuff)(ss, fmt - 1, 1);
            if (rv < 0) {
                return rv;
            }
            continue;
        }
        fmt0 = fmt - 1;

        /*
        ** Gobble up the % format string. Hopefully we have handled all
        ** of the strange cases!
        */
        flags = 0;
        c = *fmt++;
        if (c == '%') {
            /* quoting a % with %% */
            rv = (*ss->stuff)(ss, fmt - 1, 1);
            if (rv < 0) {
                return rv;
            }
            continue;
        }

        if( nas != NULL ){
            /* the fmt contains the Numbered Arguments feature */
            i = 0;
            while( c && c != '$' ){         /* should imporve error check later */
                i = ( i * 10 ) + ( c - '0' );
                c = *fmt++;
            }

            if( nas[i-1].type == TYPE_UNKNOWN ){
                if( nas && ( nas != nasArray ) )
                    js_free( nas );
                return -1;
            }

            ap = nas[i-1].ap;
            dolPt = fmt;
            c = *fmt++;
        }

        /*
         * Examine optional flags.  Note that we do not implement the
         * '#' flag of sprintf().  The ANSI C spec. of the '#' flag is
         * somewhat ambiguous and not ideal, which is perhaps why
         * the various sprintf() implementations are inconsistent
         * on this feature.
         */
        while ((c == '-') || (c == '+') || (c == ' ') || (c == '0')) {
            if (c == '-') flags |= FLAG_LEFT;
            if (c == '+') flags |= FLAG_SIGNED;
            if (c == ' ') flags |= FLAG_SPACED;
            if (c == '0') flags |= FLAG_ZEROS;
            c = *fmt++;
        }
        if (flags & FLAG_SIGNED) flags &= ~FLAG_SPACED;
        if (flags & FLAG_LEFT) flags &= ~FLAG_ZEROS;

        /* width */
        if (c == '*') {
            c = *fmt++;
            width = va_arg(ap, int);
        } else {
            width = 0;
            while ((c >= '0') && (c <= '9')) {
                width = (width * 10) + (c - '0');
                c = *fmt++;
            }
        }

        /* precision */
        prec = -1;
        if (c == '.') {
            c = *fmt++;
            if (c == '*') {
                c = *fmt++;
                prec = va_arg(ap, int);
            } else {
                prec = 0;
                while ((c >= '0') && (c <= '9')) {
                    prec = (prec * 10) + (c - '0');
                    c = *fmt++;
                }
            }
        }

        /* size */
        type = TYPE_INTN;
        if (c == 'h') {
            type = TYPE_INT16;
            c = *fmt++;
        } else if (c == 'L') {
            /* XXX not quite sure here */
            type = TYPE_INT64;
            c = *fmt++;
        } else if (c == 'l') {
            type = TYPE_INT32;
            c = *fmt++;
            if (c == 'l') {
                type = TYPE_INT64;
                c = *fmt++;
            }
        }

        /* format */
        hexp = hex;
        switch (c) {
          case 'd': case 'i':                   /* decimal/integer */
            radix = 10;
            goto fetch_and_convert;

          case 'o':                             /* octal */
            radix = 8;
            type |= 1;
            goto fetch_and_convert;

          case 'u':                             /* unsigned decimal */
            radix = 10;
            type |= 1;
            goto fetch_and_convert;

          case 'x':                             /* unsigned hex */
            radix = 16;
            type |= 1;
            goto fetch_and_convert;

          case 'X':                             /* unsigned HEX */
            radix = 16;
            hexp = HEX;
            type |= 1;
            goto fetch_and_convert;

          fetch_and_convert:
            switch (type) {
              case TYPE_INT16:
                u.l = va_arg(ap, int);
                if (u.l < 0) {
                    u.l = -u.l;
                    flags |= FLAG_NEG;
                }
                goto do_long;
              case TYPE_UINT16:
                u.l = va_arg(ap, int) & 0xffff;
                goto do_long;
              case TYPE_INTN:
                u.l = va_arg(ap, int);
                if (u.l < 0) {
                    u.l = -u.l;
                    flags |= FLAG_NEG;
                }
                goto do_long;
              case TYPE_UINTN:
                u.l = (long)va_arg(ap, unsigned int);
                goto do_long;

              case TYPE_INT32:
                u.l = va_arg(ap, int32_t);
                if (u.l < 0) {
                    u.l = -u.l;
                    flags |= FLAG_NEG;
                }
                goto do_long;
              case TYPE_UINT32:
                u.l = (long)va_arg(ap, uint32_t);
              do_long:
                rv = cvt_l(ss, u.l, width, prec, radix, type, flags, hexp);
                if (rv < 0) {
                    return rv;
                }
                break;

              case TYPE_INT64:
                u.ll = va_arg(ap, int64_t);
                if (u.ll < 0) {
                    u.ll = -u.ll;
                    flags |= FLAG_NEG;
                }
                goto do_longlong;
              case TYPE_UINT64:
                u.ll = va_arg(ap, uint64_t);
              do_longlong:
                rv = cvt_ll(ss, u.ll, width, prec, radix, type, flags, hexp);
                if (rv < 0) {
                    return rv;
                }
                break;
            }
            break;

          case 'e':
          case 'E':
          case 'f':
          case 'g':
            u.d = va_arg(ap, double);
            if( nas != NULL ){
                i = fmt - dolPt;
                if( i < (int)sizeof( pattern ) ){
                    pattern[0] = '%';
                    js_memcpy( &pattern[1], dolPt, (size_t)i );
                    rv = cvt_f(ss, u.d, pattern, &pattern[i+1] );
                }
            } else
                rv = cvt_f(ss, u.d, fmt0, fmt);

            if (rv < 0) {
                return rv;
            }
            break;

          case 'c':
            if ((flags & FLAG_LEFT) == 0) {
                while (width-- > 1) {
                    rv = (*ss->stuff)(ss, " ", 1);
                    if (rv < 0) {
                        return rv;
                    }
                }
            }
            switch (type) {
              case TYPE_INT16:
                /* Treat %hc as %c unless js_CStringsAreUTF8. */
                if (js_CStringsAreUTF8) {
                    u.wch = va_arg(ap, int);
                    utf8len = js_OneUcs4ToUtf8Char (utf8buf, u.wch);
                    rv = (*ss->stuff)(ss, (char *)utf8buf, utf8len);
                    break;
                }
              case TYPE_INTN:
                u.ch = va_arg(ap, int);
                rv = (*ss->stuff)(ss, &u.ch, 1);
                break;
            }
            if (rv < 0) {
                return rv;
            }
            if (flags & FLAG_LEFT) {
                while (width-- > 1) {
                    rv = (*ss->stuff)(ss, " ", 1);
                    if (rv < 0) {
                        return rv;
                    }
                }
            }
            break;

          case 'p':
            if (sizeof(void *) == sizeof(int32_t)) {
                type = TYPE_UINT32;
            } else if (sizeof(void *) == sizeof(int64_t)) {
                type = TYPE_UINT64;
            } else if (sizeof(void *) == sizeof(int)) {
                type = TYPE_UINTN;
            } else {
                JS_ASSERT(0);
                break;
            }
            radix = 16;
            goto fetch_and_convert;

#if 0
          case 'C':
          case 'S':
          case 'E':
          case 'G':
            /* XXX not supported I suppose */
            JS_ASSERT(0);
            break;
#endif

          case 's':
            if(type == TYPE_INT16) {
                /*
                 * This would do a simple string/byte conversion
                 * unless js_CStringsAreUTF8.
                 */
                u.ws = va_arg(ap, const jschar*);
                rv = cvt_ws(ss, u.ws, width, prec, flags);
            } else {
                u.s = va_arg(ap, const char*);
                rv = cvt_s(ss, u.s, width, prec, flags);
            }
            if (rv < 0) {
                return rv;
            }
            break;

          case 'n':
            u.ip = va_arg(ap, int*);
            if (u.ip) {
                *u.ip = ss->cur - ss->base;
            }
            break;

          default:
            /* Not a % token after all... skip it */
#if 0
            JS_ASSERT(0);
#endif
            rv = (*ss->stuff)(ss, "%", 1);
            if (rv < 0) {
                return rv;
            }
            rv = (*ss->stuff)(ss, fmt - 1, 1);
            if (rv < 0) {
                return rv;
            }
        }
    }

    /* Stuff trailing NUL */
    rv = (*ss->stuff)(ss, "\0", 1);

    if( nas && ( nas != nasArray ) ){
        js_free( nas );
    }

    return rv;
}

/************************************************************************/

static int FuncStuff(SprintfState *ss, const char *sp, uint32_t len)
{
    int rv;

    rv = (*ss->func)(ss->arg, sp, len);
    if (rv < 0) {
        return rv;
    }
    ss->maxlen += len;
    return 0;
}

JS_PUBLIC_API(uint32_t) JS_sxprintf(JSStuffFunc func, void *arg,
                                    const char *fmt, ...)
{
    va_list ap;
    int rv;

    va_start(ap, fmt);
    rv = JS_vsxprintf(func, arg, fmt, ap);
    va_end(ap);
    return rv;
}

JS_PUBLIC_API(uint32_t) JS_vsxprintf(JSStuffFunc func, void *arg,
                                     const char *fmt, va_list ap)
{
    SprintfState ss;
    int rv;

    ss.stuff = FuncStuff;
    ss.func = func;
    ss.arg = arg;
    ss.maxlen = 0;
    rv = dosprintf(&ss, fmt, ap);
    return (rv < 0) ? UINT32_MAX : ss.maxlen;
}

/*
** Stuff routine that automatically grows the malloc'd output buffer
** before it overflows.
*/
static int GrowStuff(SprintfState *ss, const char *sp, uint32_t len)
{
    ptrdiff_t off;
    char *newbase;
    uint32_t newlen;

    off = ss->cur - ss->base;
    if (off + len >= ss->maxlen) {
        /* Grow the buffer */
        newlen = ss->maxlen + ((len > 32) ? len : 32);
        if (ss->base) {
            newbase = (char*) js_realloc(ss->base, newlen);
        } else {
            newbase = (char*) js_malloc(newlen);
        }
        if (!newbase) {
            /* Ran out of memory */
            return -1;
        }
        ss->base = newbase;
        ss->maxlen = newlen;
        ss->cur = ss->base + off;
    }

    /* Copy data */
    while (len) {
        --len;
        *ss->cur++ = *sp++;
    }
    JS_ASSERT(uint32_t(ss->cur - ss->base) <= ss->maxlen);
    return 0;
}

/*
** sprintf into a malloc'd buffer
*/
JS_PUBLIC_API(char *) JS_smprintf(const char *fmt, ...)
{
    va_list ap;
    char *rv;

    va_start(ap, fmt);
    rv = JS_vsmprintf(fmt, ap);
    va_end(ap);
    return rv;
}

/*
** Free memory allocated, for the caller, by JS_smprintf
*/
JS_PUBLIC_API(void) JS_smprintf_free(char *mem)
{
        js_free(mem);
}

JS_PUBLIC_API(char *) JS_vsmprintf(const char *fmt, va_list ap)
{
    SprintfState ss;
    int rv;

    ss.stuff = GrowStuff;
    ss.base = 0;
    ss.cur = 0;
    ss.maxlen = 0;
    rv = dosprintf(&ss, fmt, ap);
    if (rv < 0) {
        if (ss.base) {
            js_free(ss.base);
        }
        return 0;
    }
    return ss.base;
}

/*
** Stuff routine that discards overflow data
*/
static int LimitStuff(SprintfState *ss, const char *sp, uint32_t len)
{
    uint32_t limit = ss->maxlen - (ss->cur - ss->base);

    if (len > limit) {
        len = limit;
    }
    while (len) {
        --len;
        *ss->cur++ = *sp++;
    }
    return 0;
}

/*
** sprintf into a fixed size buffer. Make sure there is a NUL at the end
** when finished.
*/
JS_PUBLIC_API(uint32_t) JS_snprintf(char *out, uint32_t outlen, const char *fmt, ...)
{
    va_list ap;
    int rv;

    JS_ASSERT(int32_t(outlen) > 0);
    if (int32_t(outlen) <= 0) {
        return 0;
    }

    va_start(ap, fmt);
    rv = JS_vsnprintf(out, outlen, fmt, ap);
    va_end(ap);
    return rv;
}

JS_PUBLIC_API(uint32_t) JS_vsnprintf(char *out, uint32_t outlen,const char *fmt,
                                     va_list ap)
{
    SprintfState ss;
    uint32_t n;

    JS_ASSERT(int32_t(outlen) > 0);
    if (int32_t(outlen) <= 0) {
        return 0;
    }

    ss.stuff = LimitStuff;
    ss.base = out;
    ss.cur = out;
    ss.maxlen = outlen;
    (void) dosprintf(&ss, fmt, ap);

    /* If we added chars, and we didn't append a null, do it now. */
    if( (ss.cur != ss.base) && (ss.cur[-1] != '\0') )
        ss.cur[-1] = '\0';

    n = ss.cur - ss.base;
    return n ? n - 1 : n;
}

JS_PUBLIC_API(char *) JS_sprintf_append(char *last, const char *fmt, ...)
{
    va_list ap;
    char *rv;

    va_start(ap, fmt);
    rv = JS_vsprintf_append(last, fmt, ap);
    va_end(ap);
    return rv;
}

JS_PUBLIC_API(char *) JS_vsprintf_append(char *last, const char *fmt, va_list ap)
{
    SprintfState ss;
    int rv;

    ss.stuff = GrowStuff;
    if (last) {
        int lastlen = strlen(last);
        ss.base = last;
        ss.cur = last + lastlen;
        ss.maxlen = lastlen;
    } else {
        ss.base = 0;
        ss.cur = 0;
        ss.maxlen = 0;
    }
    rv = dosprintf(&ss, fmt, ap);
    if (rv < 0) {
        if (ss.base) {
            js_free(ss.base);
        }
        return 0;
    }
    return ss.base;
}