/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

/*
 * JS lexical scanner.
 */
#include <stdio.h>	/* first to avoid trouble on some systems */
#include <errno.h>
#include <limits.h>
#include <math.h>
#include <memory.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "prtypes.h"
#ifndef NSPR20
#include "prarena.h"
#else
#include "plarena.h"
#endif
#include "prlog.h"
#include "prdtoa.h"
#include "prprf.h"
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsemit.h"
#include "jsnum.h"
#include "jsopcode.h"
#include "jsregexp.h"
#include "jsscan.h"

#define RESERVE_JAVA_KEYWORDS

static struct keyword {
    char        *name;
    int16       tokentype;      /* JSTokenType */
    int8        op;             /* JSOp */
    int8        version;        /* JSVersion */
} keywords[] = {
    {"break",           TOK_BREAK,              JSOP_NOP},
    {"case",            TOK_CASE,               JSOP_NOP},
    {"continue",        TOK_CONTINUE,           JSOP_NOP},
    {"default",         TOK_DEFAULT,            JSOP_NOP},
    {"delete",          TOK_DELETE,             JSOP_NOP},
    {"do",              TOK_DO,                 JSOP_NOP},
    {"else",            TOK_ELSE,               JSOP_NOP},
    {"export",          TOK_EXPORT,             JSOP_NOP,       JSVERSION_1_2},
    {"false",           TOK_PRIMARY,            JSOP_FALSE},
    {"for",             TOK_FOR,                JSOP_NOP},
    {"function",        TOK_FUNCTION,           JSOP_NOP},
    {"if",              TOK_IF,                 JSOP_NOP},
    {"in",              TOK_IN,                 JSOP_NOP},
    {"new",             TOK_NEW,                JSOP_NEW},
    {"null",            TOK_PRIMARY,            JSOP_NULL},
    {"return",          TOK_RETURN,             JSOP_NOP},
    {"switch",          TOK_SWITCH,             JSOP_NOP},
    {"this",            TOK_PRIMARY,            JSOP_THIS},
    {"true",            TOK_PRIMARY,            JSOP_TRUE},
    {"typeof",          TOK_UNARYOP,            JSOP_TYPEOF},
    {"var",             TOK_VAR,                JSOP_NOP},
    {"void",            TOK_UNARYOP,            JSOP_VOID},
    {"while",           TOK_WHILE,              JSOP_NOP},
    {"with",            TOK_WITH,               JSOP_NOP},

#ifdef RESERVE_JAVA_KEYWORDS
    {"abstract",        TOK_RESERVED,           JSOP_NOP},
    {"boolean",         TOK_RESERVED,           JSOP_NOP},
    {"byte",            TOK_RESERVED,           JSOP_NOP},
    {"catch",           TOK_RESERVED,           JSOP_NOP},
    {"char",            TOK_RESERVED,           JSOP_NOP},
    {"class",           TOK_RESERVED,           JSOP_NOP},
    {"const",           TOK_RESERVED,           JSOP_NOP},
    {"double",          TOK_RESERVED,           JSOP_NOP},
    {"extends",         TOK_RESERVED,           JSOP_NOP},
    {"final",           TOK_RESERVED,           JSOP_NOP},
    {"finally",         TOK_RESERVED,           JSOP_NOP},
    {"float",           TOK_RESERVED,           JSOP_NOP},
    {"goto",            TOK_RESERVED,           JSOP_NOP},
    {"implements",      TOK_RESERVED,           JSOP_NOP},
    {"import",          TOK_IMPORT,             JSOP_NOP},
    {"instanceof",      TOK_RESERVED,           JSOP_NOP},
    {"int",             TOK_RESERVED,           JSOP_NOP},
    {"interface",       TOK_RESERVED,           JSOP_NOP},
    {"long",            TOK_RESERVED,           JSOP_NOP},
    {"native",          TOK_RESERVED,           JSOP_NOP},
    {"package",         TOK_RESERVED,           JSOP_NOP},
    {"private",         TOK_RESERVED,           JSOP_NOP},
    {"protected",       TOK_RESERVED,           JSOP_NOP},
    {"public",          TOK_RESERVED,           JSOP_NOP},
    {"short",           TOK_RESERVED,           JSOP_NOP},
    {"static",          TOK_RESERVED,           JSOP_NOP},
    {"super",           TOK_PRIMARY,            JSOP_NOP},
    {"synchronized",    TOK_RESERVED,           JSOP_NOP},
    {"throw",           TOK_RESERVED,           JSOP_NOP},
    {"throws",          TOK_RESERVED,           JSOP_NOP},
    {"transient",       TOK_RESERVED,           JSOP_NOP},
    {"try",             TOK_RESERVED,           JSOP_NOP},
    {"volatile",        TOK_RESERVED,           JSOP_NOP},
#endif

    {0}
};

JSBool
js_InitScanner(JSContext *cx)
{
    struct keyword *kw;
    JSAtom *atom;

    for (kw = keywords; kw->name; kw++) {
	atom = js_Atomize(cx, kw->name, strlen(kw->name), 0);
	if (!atom)
	    return JS_FALSE;
	atom->kwindex = (kw->version <= cx->version) ? kw - keywords : -1;
    }
    return JS_TRUE;
}

JS_FRIEND_API(void)
js_MapKeywords(void (*mapfun)(const char *))
{
    struct keyword *kw;

    for (kw = keywords; kw->name; kw++)
	mapfun(kw->name);
}

JSTokenStream *
js_NewTokenStream(JSContext *cx, const jschar *base, size_t length,
		  const char *filename, uintN lineno,
		  JSPrincipals *principals)
{
    JSTokenStream *ts;

    ts = js_NewBufferTokenStream(cx, base, length);
    if (!ts)
	return NULL;
    ts->filename = filename;
    ts->lineno = lineno;
    if (principals)
        JSPRINCIPALS_HOLD(cx, principals);
    ts->principals = principals;
    return ts;
}

JS_FRIEND_API(JSTokenStream *)
js_NewBufferTokenStream(JSContext *cx, const jschar *base, size_t length)
{
    size_t nb;
    JSTokenStream *ts;

    nb = sizeof(JSTokenStream) + JS_LINE_LIMIT * sizeof(jschar);
    PR_ARENA_ALLOCATE(ts, &cx->tempPool, nb);
    if (!ts) {
	JS_ReportOutOfMemory(cx);
	return NULL;
    }
    memset(ts, 0, nb);
    CLEAR_PUSHBACK(ts);
    ts->lineno = 1;
    ts->linebuf.base = ts->linebuf.limit = ts->linebuf.ptr = (jschar *)(ts + 1);
    ts->userbuf.base = (jschar *)base;
    ts->userbuf.limit = (jschar *)base + length;
    ts->userbuf.ptr = (jschar *)base;
    return ts;
}

#ifdef JSFILE
JS_FRIEND_API(JSTokenStream *)
js_NewFileTokenStream(JSContext *cx, const char *filename)
{
    JSTokenStream *ts;
    FILE *file;

    ts = js_NewBufferTokenStream(cx, NULL, 0);
    if (!ts)
	return NULL;
    file = fopen(filename, "r");
    if (!file) {
	JS_ReportError(cx, "can't open %s: %s", filename, strerror(errno));
	return NULL;
    }
    ts->file = file;
    ts->filename = filename;
    return ts;
}
#endif

JS_FRIEND_API(JSBool)
js_CloseTokenStream(JSContext *cx, JSTokenStream *ts)
{
    if (ts->principals)
        JSPRINCIPALS_DROP(cx, ts->principals);
#ifdef JSFILE
    return !ts->file || fclose(ts->file) == 0;
#else
    return JS_TRUE;
#endif
}

static int32
GetChar(JSTokenStream *ts)
{
    ptrdiff_t length;
    jschar *nl;
    int32 c;

    if (ts->ungetpos != 0) {
	c = ts->ungetbuf[--ts->ungetpos];
    } else {
	if (ts->linebuf.ptr >= ts->linebuf.limit) {
#ifdef JSFILE
	    if (ts->file) {
		char cbuf[JS_LINE_LIMIT];
		ptrdiff_t i;

		if (!fgets(cbuf, JS_LINE_LIMIT, ts->file)) {
		    ts->flags |= TSF_EOF;
		    return EOF;
		}
		length = strlen(cbuf);
		for (i = 0; i < length; i++)
		    ts->linebuf.base[i] = (jschar) cbuf[i];
	    } else
#endif
	    {
		length = ts->userbuf.limit - ts->userbuf.ptr;
		if (length <= 0) {
		    ts->flags |= TSF_EOF;
		    return EOF;
		}

		/*
		 * Any one of \n, \r, or \r\n ends a line (longest match wins).
		 */
		for (nl = ts->userbuf.ptr; nl < ts->userbuf.limit; nl++) {
		    if (*nl == '\n')
			break;
		    if (*nl == '\r') {
			if (nl + 1 < ts->userbuf.limit && nl[1] == '\n')
			    nl++;
			break;
		    }
		}

		/*
		 * If there was a line terminator, copy thru it into linebuf.
		 * Else copy JS_LINE_LIMIT-1 bytes into linebuf.
		 */
		if (nl < ts->userbuf.limit)
		    length = nl - ts->userbuf.ptr + 1;
		if (length >= JS_LINE_LIMIT)
		    length = JS_LINE_LIMIT - 1;
		js_strncpy(ts->linebuf.base, ts->userbuf.ptr, length);
		ts->userbuf.ptr += length;

		/*
		 * Make sure linebuf contains \n for EOL (don't do this in
		 * userbuf because the user's string might be readonly).
		 */
		if (nl < ts->userbuf.limit) {
		    if (*nl == '\r') {
			if (ts->linebuf.base[length-1] == '\r')
			    ts->linebuf.base[length-1] = '\n';
		    } else if (*nl == '\n') {
			if (nl > ts->userbuf.base &&
			    nl[-1] == '\r' &&
			    ts->linebuf.base[length-2] == '\r') {
			    length--;
			    PR_ASSERT(ts->linebuf.base[length] == '\n');
			    ts->linebuf.base[length-1] = '\n';
			}
		    }
		}
	    }
	    ts->linebuf.limit = ts->linebuf.base + length;
	    ts->linebuf.ptr = ts->linebuf.base;
	}
	c = *ts->linebuf.ptr++;
    }
    if (c == '\n')
	ts->lineno++;
    return c;
}

static void
UngetChar(JSTokenStream *ts, int32 c)
{
    if (c == EOF)
	return;
    PR_ASSERT(ts->ungetpos < sizeof ts->ungetbuf / sizeof ts->ungetbuf[0]);
    if (c == '\n')
	ts->lineno--;
    ts->ungetbuf[ts->ungetpos++] = (jschar)c;
}

static int32
PeekChar(JSTokenStream *ts)
{
    int32 c;

    c = GetChar(ts);
    UngetChar(ts, c);
    return c;
}

static JSBool
PeekChars(JSTokenStream *ts, intN n, jschar *cp)
{
    intN i, j;
    int32 c;

    for (i = 0; i < n; i++) {
	c = GetChar(ts);
	if (c == EOF)
	    break;
	cp[i] = (jschar)c;
    }
    for (j = i - 1; j >= 0; j--)
	UngetChar(ts, cp[j]);
    return i == n;
}

static void
SkipChars(JSTokenStream *ts, intN n)
{
    while (--n >= 0)
	GetChar(ts);
}

static int32
MatchChar(JSTokenStream *ts, int32 nextChar)
{
    int32 c;

    c = GetChar(ts);
    if (c == nextChar)
	return 1;
    UngetChar(ts, c);
    return 0;
}

void
js_ReportCompileError(JSContext *cx, JSTokenStream *ts, const char *format,
		      ...)
{
    va_list ap;
    char *message;
    jschar *limit, lastc;
    JSErrorReporter onError;
    JSErrorReport report;
    JSString *linestr;

    va_start(ap, format);
    message = PR_vsmprintf(format, ap);
    va_end(ap);
    if (!message) {
	JS_ReportOutOfMemory(cx);
	return;
    }

    PR_ASSERT(ts->linebuf.limit < ts->linebuf.base + JS_LINE_LIMIT);
    limit = ts->linebuf.limit;
    lastc = limit[-1];
    if (lastc == '\n')
	limit[-1] = 0;
    onError = cx->errorReporter;
    if (onError) {
	report.filename = ts->filename;
	report.lineno = ts->lineno;
	linestr = js_NewStringCopyZ(cx, ts->linebuf.base, 0);
	report.linebuf  = linestr
			  ? JS_GetStringBytes(linestr)
			  : NULL;
	report.tokenptr = linestr
			  ? report.linebuf + (ts->token.ptr - ts->linebuf.base)
			  : NULL;
	report.uclinebuf = ts->linebuf.base;
	report.uctokenptr = ts->token.ptr;
	(*onError)(cx, message, &report);
#if !defined XP_PC || !defined _MSC_VER || _MSC_VER > 800
    } else {
	if (!(ts->flags & TSF_INTERACTIVE))
	    fprintf(stderr, "JavaScript error: ");
	if (ts->filename)
	    fprintf(stderr, "%s, ", ts->filename);
	if (ts->lineno)
	    fprintf(stderr, "line %u: ", ts->lineno);
	fprintf(stderr, "%s:\n%s\n", message, ts->linebuf.base);
#endif
    }
    if (lastc == '\n')
	limit[-1] = lastc;
    free(message);
}

JSTokenType
js_PeekToken(JSContext *cx, JSTokenStream *ts, JSCodeGenerator *cg)
{
    JSTokenType tt;

    tt = ts->pushback.type;
    if (tt == TOK_EOF) {
	ts->flags |= TSF_LOOKAHEAD;
	tt = js_GetToken(cx, ts, cg);
	ts->flags &= ~TSF_LOOKAHEAD;
	js_UngetToken(ts);
    }
    return tt;
}

JSTokenType
js_PeekTokenSameLine(JSContext *cx, JSTokenStream *ts, JSCodeGenerator *cg)
{
    uintN newlines;
    JSTokenType tt;

    newlines = ts->flags & TSF_NEWLINES;
    if (!newlines)
	SCAN_NEWLINES(ts);
    tt = js_PeekToken(cx, ts, cg);
    if (!newlines)
	HIDE_NEWLINES(ts);
    return tt;
}

#define TBINCR         64

static JSBool
GrowTokenBuf(JSContext *cx, JSTokenBuf *tb)
{
    jschar *base;
    ptrdiff_t offset, length;
    size_t tbincr, tbsize;
    PRArenaPool *pool;

    base = tb->base;
    offset = tb->ptr - base;
    length = tb->limit - base;
    tbincr = TBINCR * sizeof(jschar);
    pool = &cx->tempPool;
    if (!base) {
	PR_ARENA_ALLOCATE(base, pool, tbincr);
    } else {
	tbsize = (size_t)(length * sizeof(jschar));
	PR_ARENA_GROW(base, pool, tbsize, tbincr);
    }
    if (!base) {
	JS_ReportOutOfMemory(cx);
	return JS_FALSE;
    }
    tb->base = base;
    tb->limit = base + length + TBINCR;
    tb->ptr = base + offset;
    return JS_TRUE;
}

static JSBool
AddToTokenBuf(JSContext *cx, JSTokenBuf *tb, jschar c)
{
    if (tb->ptr == tb->limit && !GrowTokenBuf(cx, tb))
	return JS_FALSE;
    *tb->ptr++ = c;
    return JS_TRUE;
}

JSTokenType
js_GetToken(JSContext *cx, JSTokenStream *ts, JSCodeGenerator *cg)
{
    int32 c;
    JSAtom *atom;

#define INIT_TOKENBUF(tb)   ((tb)->ptr = (tb)->base)
#define FINISH_TOKENBUF(tb) if (!AddToTokenBuf(cx, tb, 0)) RETURN(TOK_ERROR)
#define TOKEN_LENGTH(tb)    ((tb)->ptr - (tb)->base - 1)
#define RETURN(tt)          { if (tt == TOK_ERROR) ts->flags |= TSF_ERROR;    \
			      return (ts->token.type = tt); }

#define NOTE_NEWLINE() {                                                      \
    if (cg) {                                                                 \
	if (ts->flags & TSF_LOOKAHEAD) {                                      \
	    /* Don't emit newline source notes during lookahead. */           \
	    ts->newlines++;                                                   \
	} else {                                                              \
	    if (js_NewSrcNote(cx, cg, SRC_NEWLINE) < 0)                       \
		RETURN(TOK_ERROR);                                            \
	}                                                                     \
    }                                                                         \
}

    /* If there was a fatal error, keep returning TOK_ERROR. */
    if (ts->flags & TSF_ERROR)
	return TOK_ERROR;

    /* If done with lookahead, emit source notes for any skipped newlines. */
    if (!(ts->flags & TSF_LOOKAHEAD) &&
	ts->newlines != 0 &&
	!js_FlushNewlines(cx, ts, cg)) {
	RETURN(TOK_ERROR);
    }

    /* Check for a pushed-back token resulting from mismatching lookahead. */
    if (ts->pushback.type != TOK_EOF) {
	ts->token = ts->pushback;
	CLEAR_PUSHBACK(ts);
	return ts->token.type;
    }

retry:
    do {
	c = GetChar(ts);
	if (c == '\n') {
	    NOTE_NEWLINE();
	    if (ts->flags & TSF_NEWLINES)
		break;
	}
    } while (JS_ISSPACE(c));

    ts->token.ptr = ts->linebuf.ptr - 1;
    if (c == EOF)
	RETURN(TOK_EOF);

    if (JS_ISIDENT(c)) {
	INIT_TOKENBUF(&ts->tokenbuf);
	do {
	    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		RETURN(TOK_ERROR);
	    c = GetChar(ts);
	} while (JS_ISIDENT2(c));
	UngetChar(ts, c);
	FINISH_TOKENBUF(&ts->tokenbuf);

	atom = js_AtomizeChars(cx,
			       ts->tokenbuf.base,
			       TOKEN_LENGTH(&ts->tokenbuf),
			       ATOM_NOHOLD);
	if (!atom)
	    RETURN(TOK_ERROR);
	if (atom->kwindex >= 0) {
	    struct keyword *kw;

	    kw = &keywords[atom->kwindex];
	    ts->token.u.op = kw->op;
	    RETURN(kw->tokentype);
	}
	ts->token.u.atom = atom;
	RETURN(TOK_NAME);
    }

    if (JS7_ISDEC(c) || (c == '.' && JS7_ISDEC(PeekChar(ts)))) {
	jsint radix;
	jschar *endptr;
	jsdouble dval;

	radix = 10;
	INIT_TOKENBUF(&ts->tokenbuf);

	if (c == '0') {
	    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		RETURN(TOK_ERROR);
	    c = GetChar(ts);
	    if (JS_TOLOWER(c) == 'x') {
		if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		    RETURN(TOK_ERROR);
		c = GetChar(ts);
		radix = 16;
	    } else if (JS7_ISDEC(c) && c < '8') {
		radix = 8;
	    }
	}

	while (JS7_ISHEX(c)) {
	    if (radix < 16 && (JS7_ISLET(c) || (radix == 8 && c >= '8')))
		break;
	    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		RETURN(TOK_ERROR);
	    c = GetChar(ts);
	}

	if (radix == 10 && (c == '.' || JS_TOLOWER(c) == 'e')) {
	    if (c == '.') {
		do {
		    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
			RETURN(TOK_ERROR);
		    c = GetChar(ts);
		} while (JS7_ISDEC(c));
	    }
	    if (JS_TOLOWER(c) == 'e') {
		if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		    RETURN(TOK_ERROR);
		c = GetChar(ts);
		if (c == '+' || c == '-') {
		    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
			RETURN(TOK_ERROR);
		    c = GetChar(ts);
		}
		if (!JS7_ISDEC(c)) {
		    js_ReportCompileError(cx, ts, "missing exponent");
		    RETURN(TOK_ERROR);
		}
		do {
		    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
			RETURN(TOK_ERROR);
		    c = GetChar(ts);
		} while (JS7_ISDEC(c));
	    }
	}

	UngetChar(ts, c);
	FINISH_TOKENBUF(&ts->tokenbuf);

	if (radix == 10) {
	    /* Let js_strtod() do the hard work and validity checks. */
	    if (!js_strtod(ts->tokenbuf.base, &endptr, &dval)) {
		js_ReportCompileError(cx, ts,
				      "floating point literal out of range");
		RETURN(TOK_ERROR);
	    }
	} else {
	    /* Let js_strtol() do the hard work, then check for overflow */
	    if (!js_strtol(ts->tokenbuf.base, &endptr, radix, &dval)) {
		js_ReportCompileError(cx, ts, "integer literal too large");
		RETURN(TOK_ERROR);
	    }
	}
	ts->token.u.dval = dval;
	RETURN(TOK_NUMBER);
    }

    if (c == '"' || c == '\'') {
	int32 val, qc = c;

	INIT_TOKENBUF(&ts->tokenbuf);
	while ((c = GetChar(ts)) != qc) {
	    if (c == '\n' || c == EOF) {
		UngetChar(ts, c);
		js_ReportCompileError(cx, ts, "unterminated string literal");
		RETURN(TOK_ERROR);
	    }
	    if (c == '\\') {
		switch (c = GetChar(ts)) {
		  case 'b': c = '\b'; break;
		  case 'f': c = '\f'; break;
		  case 'n': c = '\n'; break;
		  case 'r': c = '\r'; break;
		  case 't': c = '\t'; break;
		  case 'v': c = '\v'; break;

		  default:
		    if ('0' <= c && c < '8') {
			val = JS7_UNDEC(c);
			c = PeekChar(ts);
			if ('0' <= c && c < '8') {
			    val = 8 * val + JS7_UNDEC(c);
			    GetChar(ts);
			    c = PeekChar(ts);
			    if ('0' <= c && c < '8') {
				int32 save = val;
				val = 8 * val + JS7_UNDEC(c);
				if (val <= 0377)
				    GetChar(ts);
				else
				    val = save;
			    }
			}
			c = (jschar)val;
		    } else if (c == 'u') {
			jschar cp[4];
			if (PeekChars(ts, 4, cp) &&
			    JS7_ISHEX(cp[0]) && JS7_ISHEX(cp[1]) &&
			    JS7_ISHEX(cp[2]) && JS7_ISHEX(cp[3])) {
			    c = (((((JS7_UNHEX(cp[0]) << 4)
				    + JS7_UNHEX(cp[1])) << 4)
				  + JS7_UNHEX(cp[2])) << 4)
				+ JS7_UNHEX(cp[3]);
			    SkipChars(ts, 4);
			}
		    } else if (c == 'x') {
			jschar cp[2];
			if (PeekChars(ts, 2, cp) &&
			    JS7_ISHEX(cp[0]) && JS7_ISHEX(cp[1])) {
			    c = (JS7_UNHEX(cp[0]) << 4) + JS7_UNHEX(cp[1]);
			    SkipChars(ts, 2);
			}
		    } else if (c == '\n') {
			NOTE_NEWLINE();
		    }
		    break;
		}
	    }
	    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		RETURN(TOK_ERROR);
	}
	FINISH_TOKENBUF(&ts->tokenbuf);
	atom = js_AtomizeChars(cx,
			       ts->tokenbuf.base,
			       TOKEN_LENGTH(&ts->tokenbuf),
			       ATOM_NOHOLD);
	if (!atom)
	    RETURN(TOK_ERROR);
	ts->token.u.atom = atom;
	RETURN(TOK_STRING);
    }

    switch (c) {
      case '\n': c = TOK_EOL; break;
      case ';': c = TOK_SEMI; break;
      case '[': c = TOK_LB; break;
      case ']': c = TOK_RB; break;
      case '{': c = TOK_LC; break;
      case '}': c = TOK_RC; break;
      case '(': c = TOK_LP; break;
      case ')': c = TOK_RP; break;
      case ',': c = TOK_COMMA; break;
      case '?': c = TOK_HOOK; break;
      case ':': c = TOK_COLON; break;
      case '.': c = TOK_DOT; break;

      case '|':
	if (MatchChar(ts, c)) {
	    c = TOK_OR;
	} else if (MatchChar(ts, '=')) {
	    ts->token.u.op = JSOP_BITOR;
	    c = TOK_ASSIGN;
	} else {
	    c = TOK_BITOR;
	}
	break;

      case '^':
	if (MatchChar(ts, '=')) {
	    ts->token.u.op = JSOP_BITXOR;
	    c = TOK_ASSIGN;
	} else {
	    c = TOK_BITXOR;
	}
	break;

      case '&':
	if (MatchChar(ts, c)) {
	    c = TOK_AND;
	} else if (MatchChar(ts, '=')) {
	    ts->token.u.op = JSOP_BITAND;
	    c = TOK_ASSIGN;
	} else {
	    c = TOK_BITAND;
	}
	break;

      case '=':
	if (MatchChar(ts, c)) {
#if JS_HAS_TRIPLE_EQOPS
	    ts->token.u.op = MatchChar(ts, c) ? JSOP_NEW_EQ : cx->jsop_eq;
#else
	    ts->token.u.op = cx->jsop_eq;
#endif
	    c = TOK_EQOP;
	} else {
	    ts->token.u.op = JSOP_NOP;
	    c = TOK_ASSIGN;
	}
	break;

      case '!':
	if (MatchChar(ts, '=')) {
#if JS_HAS_TRIPLE_EQOPS
	    ts->token.u.op = MatchChar(ts, '=') ? JSOP_NEW_NE : cx->jsop_ne;
#else
	    ts->token.u.op = cx->jsop_ne;
#endif
	    c = TOK_EQOP;
	} else {
	    ts->token.u.op = JSOP_NOT;
	    c = TOK_UNARYOP;
	}
	break;

      case '<':
	/* NB: treat HTML begin-comment as comment-till-end-of-line */
	if (MatchChar(ts, '!')) {
	    if (MatchChar(ts, '-')) {
		if (MatchChar(ts, '-'))
		    goto skipline;
		UngetChar(ts, '-');
	    }
	    UngetChar(ts, '!');
	}
	if (MatchChar(ts, c)) {
	    ts->token.u.op = JSOP_LSH;
	    c = MatchChar(ts, '=') ? TOK_ASSIGN : TOK_SHOP;
	} else {
	    ts->token.u.op = MatchChar(ts, '=') ? JSOP_LE : JSOP_LT;
	    c = TOK_RELOP;
	}
	break;

      case '>':
	if (MatchChar(ts, c)) {
	    ts->token.u.op = MatchChar(ts, c) ? JSOP_URSH : JSOP_RSH;
	    c = MatchChar(ts, '=') ? TOK_ASSIGN : TOK_SHOP;
	} else {
	    ts->token.u.op = MatchChar(ts, '=') ? JSOP_GE : JSOP_GT;
	    c = TOK_RELOP;
	}
	break;

      case '*':
	ts->token.u.op = JSOP_MUL;
	c = MatchChar(ts, '=') ? TOK_ASSIGN : TOK_STAR;
	break;

      case '/':
	if (MatchChar(ts, '/')) {
skipline:
	    while ((c = GetChar(ts)) != EOF && c != '\n')
		/* skip to end of line */;
	    UngetChar(ts, c);
	    goto retry;
	}
	if (MatchChar(ts, '*')) {
	    while ((c = GetChar(ts)) != EOF
		&& !(c == '*' && MatchChar(ts, '/'))) {
		if (c == '\n') {
		    NOTE_NEWLINE();
		} else if (c == '/' && MatchChar(ts, '*')) {
		    if (MatchChar(ts, '/'))
			goto retry;
		    js_ReportCompileError(cx, ts, "nested comment");
		}
	    }
	    if (c == EOF) {
		js_ReportCompileError(cx, ts, "unterminated comment");
		RETURN(TOK_ERROR);
	    }
	    goto retry;
	}

#if JS_HAS_REGEXPS
	if (ts->flags & TSF_REGEXP) {
	    JSObject *obj;
	    uintN flags;

	    INIT_TOKENBUF(&ts->tokenbuf);
	    while ((c = GetChar(ts)) != '/') {
		if (c == '\n' || c == EOF) {
		    UngetChar(ts, c);
		    js_ReportCompileError(cx, ts,
			"unterminated regular expression literal");
		    RETURN(TOK_ERROR);
		}
		if (c == '\\') {
		    if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
			RETURN(TOK_ERROR);
		    c = GetChar(ts);
		}
		if (!AddToTokenBuf(cx, &ts->tokenbuf, (jschar)c))
		    RETURN(TOK_ERROR);
	    }
	    FINISH_TOKENBUF(&ts->tokenbuf);
	    for (flags = 0; ; ) {
		if (MatchChar(ts, 'g'))
		    flags |= JSREG_GLOB;
		else if (MatchChar(ts, 'i'))
		    flags |= JSREG_FOLD;
		else
		    break;
	    }
	    c = PeekChar(ts);
	    if (JS7_ISLET(c)) {
		ts->token.ptr = ts->linebuf.ptr - 1;
		js_ReportCompileError(cx, ts,
				      "invalid flag after regular expression");
		RETURN(TOK_ERROR);
	    }
	    obj = js_NewRegExpObject(cx,
				     ts->tokenbuf.base,
				     TOKEN_LENGTH(&ts->tokenbuf),
				     flags);
	    if (!obj)
		RETURN(TOK_ERROR);
	    atom = js_AtomizeObject(cx, obj, ATOM_NOHOLD);
	    if (!atom)
		RETURN(TOK_ERROR);
	    ts->token.u.atom = atom;
	    RETURN(TOK_OBJECT);
	}
#endif /* JS_HAS_REGEXPS */

	ts->token.u.op = JSOP_DIV;
	c = MatchChar(ts, '=') ? TOK_ASSIGN : TOK_DIVOP;
	break;

      case '%':
	ts->token.u.op = JSOP_MOD;
	c = MatchChar(ts, '=') ? TOK_ASSIGN : TOK_DIVOP;
	break;

      case '~':
	ts->token.u.op = JSOP_BITNOT;
	c = TOK_UNARYOP;
	break;

      case '+':
      case '-':
	if (MatchChar(ts, '=')) {
	    ts->token.u.op = (c == '+') ? JSOP_ADD : JSOP_SUB;
	    c = TOK_ASSIGN;
	} else if (MatchChar(ts, c)) {
	    c = (c == '+') ? TOK_INC : TOK_DEC;
	} else if (c == '-') {
	    ts->token.u.op = JSOP_NEG;
	    c = TOK_MINUS;
	} else {
	    ts->token.u.op = JSOP_POS;
	    c = TOK_PLUS;
	}
	break;

#if JS_HAS_SHARP_VARS
      case '#':
      {
	uint32 n;

	c = GetChar(ts);
	if (!JS7_ISDEC(c)) {
	    UngetChar(ts, c);
	    goto badchar;
	}
	n = (uint32)JS7_UNDEC(c);
	for (;;) {
	    c = GetChar(ts);
	    if (!JS7_ISDEC(c))
		break;
	    n = 10 * n + JS7_UNDEC(c);
	    if (n >= ATOM_INDEX_LIMIT) {
		js_ReportCompileError(cx, ts,
				      "overlarge sharp variable number");
		RETURN(TOK_ERROR);
	    }
	}
	ts->token.u.dval = (jsdouble) n;
	if (c == '=')
	    RETURN(TOK_DEFSHARP);
	if (c == '#')
	    RETURN(TOK_USESHARP);
	goto badchar;
      }

#endif /* JS_HAS_SHARP_VARS */

      badchar:
      default:
	js_ReportCompileError(cx, ts, "illegal character");
	RETURN(TOK_ERROR);
    }

    PR_ASSERT(c < TOK_LIMIT);
    RETURN(c);

#undef INIT_TOKENBUF
#undef FINISH_TOKENBUF
#undef TOKEN_LENGTH
#undef RETURN
#undef NOTE_NEWLINE
}

void
js_UngetToken(JSTokenStream *ts)
{
    PR_ASSERT(ts->pushback.type == TOK_EOF);
    if (ts->flags & TSF_ERROR)
	return;
    ts->pushback = ts->token;
}

JSBool
js_MatchToken(JSContext *cx, JSTokenStream *ts, JSCodeGenerator *cg,
		 JSTokenType tt)
{
    JSTokenType got;

    ts->flags |= TSF_LOOKAHEAD;
    got = js_GetToken(cx, ts, cg);
    ts->flags &= ~TSF_LOOKAHEAD;
    if (got == tt) {
	if (ts->newlines != 0 && !js_FlushNewlines(cx, ts, cg))
	    return JS_FALSE;
	return JS_TRUE;
    }
    js_UngetToken(ts);
    return JS_FALSE;
}

JSBool
js_FlushNewlines(JSContext *cx, JSTokenStream *ts, JSCodeGenerator *cg)
{
    while (ts->newlines != 0) {
	if (js_NewSrcNote(cx, cg, SRC_NEWLINE) < 0)
	    return JS_FALSE;
	ts->newlines--;
    }
    return JS_TRUE;
}