js/src/jsscan.h

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
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  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is Mozilla Communicator client code, released
  17  * March 31, 1998.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Netscape Communications Corporation.
  21  * Portions created by the Initial Developer are Copyright (C) 1998
  22  * the Initial Developer. All Rights Reserved.
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  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
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  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #ifndef jsscan_h___
  41 #define jsscan_h___
  42 /*
  43  * JS lexical scanner interface.
  44  */
  45 #include <stddef.h>
  46 #include <stdio.h>
  47 #include <stdarg.h>
  48 #include "jsversion.h"
  49 #include "jsopcode.h"
  50 #include "jsprvtd.h"
  51 #include "jspubtd.h"
  52 #include "jsvector.h"
  53
  54 #define JS_KEYWORD(keyword, type, op, version) \
  55     extern const char js_##keyword##_str[];
  56 #include "jskeyword.tbl"
  57 #undef JS_KEYWORD
  58
  59 namespace js {
  60
  61 enum TokenKind {
  62     TOK_ERROR = -1,                     /* well-known as the only code < EOF */
  63     TOK_EOF = 0,                        /* end of file */
  64     TOK_EOL = 1,                        /* end of line */
  65     TOK_SEMI = 2,                       /* semicolon */
  66     TOK_COMMA = 3,                      /* comma operator */
  67     TOK_ASSIGN = 4,                     /* assignment ops (= += -= etc.) */
  68     TOK_HOOK = 5, TOK_COLON = 6,        /* conditional (?:) */
  69     TOK_OR = 7,                         /* logical or (||) */
  70     TOK_AND = 8,                        /* logical and (&&) */
  71     TOK_BITOR = 9,                      /* bitwise-or (|) */
  72     TOK_BITXOR = 10,                    /* bitwise-xor (^) */
  73     TOK_BITAND = 11,                    /* bitwise-and (&) */
  74     TOK_EQOP = 12,                      /* equality ops (== !=) */
  75     TOK_RELOP = 13,                     /* relational ops (< <= > >=) */
  76     TOK_SHOP = 14,                      /* shift ops (<< >> >>>) */
  77     TOK_PLUS = 15,                      /* plus */
  78     TOK_MINUS = 16,                     /* minus */
  79     TOK_STAR = 17, TOK_DIVOP = 18,      /* multiply/divide ops (* / %) */
  80     TOK_UNARYOP = 19,                   /* unary prefix operator */
  81     TOK_INC = 20, TOK_DEC = 21,         /* increment/decrement (++ --) */
  82     TOK_DOT = 22,                       /* member operator (.) */
  83     TOK_LB = 23, TOK_RB = 24,           /* left and right brackets */
  84     TOK_LC = 25, TOK_RC = 26,           /* left and right curlies (braces) */
  85     TOK_LP = 27, TOK_RP = 28,           /* left and right parentheses */
  86     TOK_NAME = 29,                      /* identifier */
  87     TOK_NUMBER = 30,                    /* numeric constant */
  88     TOK_STRING = 31,                    /* string constant */
  89     TOK_REGEXP = 32,                    /* RegExp constant */
  90     TOK_PRIMARY = 33,                   /* true, false, null, this, super */
  91     TOK_FUNCTION = 34,                  /* function keyword */
  92     TOK_IF = 35,                        /* if keyword */
  93     TOK_ELSE = 36,                      /* else keyword */
  94     TOK_SWITCH = 37,                    /* switch keyword */
  95     TOK_CASE = 38,                      /* case keyword */
  96     TOK_DEFAULT = 39,                   /* default keyword */
  97     TOK_WHILE = 40,                     /* while keyword */
  98     TOK_DO = 41,                        /* do keyword */
  99     TOK_FOR = 42,                       /* for keyword */
 100     TOK_BREAK = 43,                     /* break keyword */
 101     TOK_CONTINUE = 44,                  /* continue keyword */
 102     TOK_IN = 45,                        /* in keyword */
 103     TOK_VAR = 46,                       /* var keyword */
 104     TOK_WITH = 47,                      /* with keyword */
 105     TOK_RETURN = 48,                    /* return keyword */
 106     TOK_NEW = 49,                       /* new keyword */
 107     TOK_DELETE = 50,                    /* delete keyword */
 108     TOK_DEFSHARP = 51,                  /* #n= for object/array initializers */
 109     TOK_USESHARP = 52,                  /* #n# for object/array initializers */
 110     TOK_TRY = 53,                       /* try keyword */
 111     TOK_CATCH = 54,                     /* catch keyword */
 112     TOK_FINALLY = 55,                   /* finally keyword */
 113     TOK_THROW = 56,                     /* throw keyword */
 114     TOK_INSTANCEOF = 57,                /* instanceof keyword */
 115     TOK_DEBUGGER = 58,                  /* debugger keyword */
 116     TOK_XMLSTAGO = 59,                  /* XML start tag open (<) */
 117     TOK_XMLETAGO = 60,                  /* XML end tag open (</) */
 118     TOK_XMLPTAGC = 61,                  /* XML point tag close (/>) */
 119     TOK_XMLTAGC = 62,                   /* XML start or end tag close (>) */
 120     TOK_XMLNAME = 63,                   /* XML start-tag non-final fragment */
 121     TOK_XMLATTR = 64,                   /* XML quoted attribute value */
 122     TOK_XMLSPACE = 65,                  /* XML whitespace */
 123     TOK_XMLTEXT = 66,                   /* XML text */
 124     TOK_XMLCOMMENT = 67,                /* XML comment */
 125     TOK_XMLCDATA = 68,                  /* XML CDATA section */
 126     TOK_XMLPI = 69,                     /* XML processing instruction */
 127     TOK_AT = 70,                        /* XML attribute op (@) */
 128     TOK_DBLCOLON = 71,                  /* namespace qualified name op (::) */
 129     TOK_ANYNAME = 72,                   /* XML AnyName singleton (*) */
 130     TOK_DBLDOT = 73,                    /* XML descendant op (..) */
 131     TOK_FILTER = 74,                    /* XML filtering predicate op (.()) */
 132     TOK_XMLELEM = 75,                   /* XML element node type (no token) */
 133     TOK_XMLLIST = 76,                   /* XML list node type (no token) */
 134     TOK_YIELD = 77,                     /* yield from generator function */
 135     TOK_ARRAYCOMP = 78,                 /* array comprehension initialiser */
 136     TOK_ARRAYPUSH = 79,                 /* array push within comprehension */
 137     TOK_LEXICALSCOPE = 80,              /* block scope AST node label */
 138     TOK_LET = 81,                       /* let keyword */
 139     TOK_SEQ = 82,                       /* synthetic sequence of statements,
 140                                            not a block */
 141     TOK_FORHEAD = 83,                   /* head of for(;;)-style loop */
 142     TOK_ARGSBODY = 84,                  /* formal args in list + body at end */
 143     TOK_UPVARS = 85,                    /* lexical dependencies as JSAtomList
 144                                            of definitions paired with a parse
 145                                            tree full of uses of those names */
 146     TOK_RESERVED,                       /* reserved keywords */
 147     TOK_STRICT_RESERVED,                /* reserved keywords in strict mode */
 148     TOK_LIMIT                           /* domain size */
 149 };
 150
 151 static inline bool
 152 TokenKindIsXML(TokenKind tt)
 153 {
 154     return tt == TOK_AT || tt == TOK_DBLCOLON || tt == TOK_ANYNAME;
 155 }
 156
 157 static inline bool
 158 TreeTypeIsXML(TokenKind tt)
 159 {
 160     return tt == TOK_XMLCOMMENT || tt == TOK_XMLCDATA || tt == TOK_XMLPI ||
 161            tt == TOK_XMLELEM || tt == TOK_XMLLIST;
 162 }
 163
 164 static inline bool
 165 TokenKindIsDecl(TokenKind tt)
 166 {
 167 #if JS_HAS_BLOCK_SCOPE
 168     return tt == TOK_VAR || tt == TOK_LET;
 169 #else
 170     return tt == TOK_VAR;
 171 #endif
 172 }
 173
 174 struct TokenPtr {
 175     uint32              index;          /* index of char in physical line */
 176     uint32              lineno;         /* physical line number */
 177
 178     bool operator==(const TokenPtr& bptr) {
 179         return index == bptr.index && lineno == bptr.lineno;
 180     }
 181
 182     bool operator!=(const TokenPtr& bptr) {
 183         return index != bptr.index || lineno != bptr.lineno;
 184     }
 185
 186     bool operator <(const TokenPtr& bptr) {
 187         return lineno < bptr.lineno ||
 188                (lineno == bptr.lineno && index < bptr.index);
 189     }
 190
 191     bool operator <=(const TokenPtr& bptr) {
 192         return lineno < bptr.lineno ||
 193                (lineno == bptr.lineno && index <= bptr.index);
 194     }
 195
 196     bool operator >(const TokenPtr& bptr) {
 197         return !(*this <= bptr);
 198     }
 199
 200     bool operator >=(const TokenPtr& bptr) {
 201         return !(*this < bptr);
 202     }
 203 };
 204
 205 struct TokenPos {
 206     TokenPtr          begin;          /* first character and line of token */
 207     TokenPtr          end;            /* index 1 past last char, last line */
 208
 209     bool operator==(const TokenPos& bpos) {
 210         return begin == bpos.begin && end == bpos.end;
 211     }
 212
 213     bool operator!=(const TokenPos& bpos) {
 214         return begin != bpos.begin || end != bpos.end;
 215     }
 216
 217     bool operator <(const TokenPos& bpos) {
 218         return begin < bpos.begin;
 219     }
 220
 221     bool operator <=(const TokenPos& bpos) {
 222         return begin <= bpos.begin;
 223     }
 224
 225     bool operator >(const TokenPos& bpos) {
 226         return !(*this <= bpos);
 227     }
 228
 229     bool operator >=(const TokenPos& bpos) {
 230         return !(*this < bpos);
 231     }
 232 };
 233
 234 struct Token {
 235     TokenKind           type;           /* char value or above enumerator */
 236     TokenPos            pos;            /* token position in file */
 237     jschar              *ptr;           /* beginning of token in line buffer */
 238     union {
 239         struct {                        /* name or string literal */
 240             JSOp        op;             /* operator, for minimal parser */
 241             JSAtom      *atom;          /* atom table entry */
 242         } s;
 243         uintN           reflags;        /* regexp flags, use tokenbuf to access
 244                                            regexp chars */
 245         struct {                        /* atom pair, for XML PIs */
 246             JSAtom      *atom2;         /* auxiliary atom table entry */
 247             JSAtom      *atom;          /* main atom table entry */
 248         } p;
 249         jsdouble        dval;           /* floating point number */
 250     } u;
 251 };
 252
 253 enum TokenStreamFlags
 254 {
 255     TSF_ERROR = 0x01,           /* fatal error while compiling */
 256     TSF_EOF = 0x02,             /* hit end of file */
 257     TSF_NEWLINES = 0x04,        /* tokenize newlines */
 258     TSF_OPERAND = 0x08,         /* looking for operand, not operator */
 259     TSF_UNEXPECTED_EOF = 0x10,  /* unexpected end of input, i.e. TOK_EOF not at top-level. */
 260     TSF_KEYWORD_IS_NAME = 0x20, /* Ignore keywords and return TOK_NAME instead to the parser. */
 261     TSF_STRICT_MODE_CODE = 0x40,/* Tokenize as appropriate for strict mode code. */
 262     TSF_DIRTYLINE = 0x80,       /* non-whitespace since start of line */
 263     TSF_OWNFILENAME = 0x100,    /* ts->filename is malloc'd */
 264     TSF_XMLTAGMODE = 0x200,     /* scanning within an XML tag in E4X */
 265     TSF_XMLTEXTMODE = 0x400,    /* scanning XMLText terminal from E4X */
 266     TSF_XMLONLYMODE = 0x800,    /* don't scan {expr} within text/tag */
 267     TSF_OCTAL_CHAR = 0x1000,    /* observed a octal character escape */
 268
 269     /*
 270      * To handle the hard case of contiguous HTML comments, we want to clear the
 271      * TSF_DIRTYINPUT flag at the end of each such comment.  But we'd rather not
 272      * scan for --> within every //-style comment unless we have to.  So we set
 273      * TSF_IN_HTML_COMMENT when a <!-- is scanned as an HTML begin-comment, and
 274      * clear it (and TSF_DIRTYINPUT) when we scan --> either on a clean line, or
 275      * only if (ts->flags & TSF_IN_HTML_COMMENT), in a //-style comment.
 276      *
 277      * This still works as before given a malformed comment hiding hack such as:
 278      *
 279      *    <script>
 280      *      <!-- comment hiding hack #1
 281      *      code goes here
 282      *      // --> oops, markup for script-unaware browsers goes here!
 283      *    </script>
 284      *
 285      * It does not cope with malformed comment hiding hacks where --> is hidden
 286      * by C-style comments, or on a dirty line.  Such cases are already broken.
 287      */
 288     TSF_IN_HTML_COMMENT = 0x2000
 289 };
 290
 291 #define t_op            u.s.op
 292 #define t_reflags       u.reflags
 293 #define t_atom          u.s.atom
 294 #define t_atom2         u.p.atom2
 295 #define t_dval          u.dval
 296
 297 class TokenStream
 298 {
 299     static const size_t ntokens = 4;                /* 1 current + 2 lookahead, rounded
 300                                                        to power of 2 to avoid divmod by 3 */
 301     static const uintN ntokensMask = ntokens - 1;
 302
 303   public:
 304     typedef Vector<jschar, 32> CharBuffer;
 305
 306     /*
 307      * To construct a TokenStream, first call the constructor, which is
 308      * infallible, then call |init|, which can fail. To destroy a TokenStream,
 309      * first call |close| then call the destructor. If |init| fails, do not call
 310      * |close|.
 311      *
 312      * This class uses JSContext.tempPool to allocate internal buffers. The
 313      * caller should JS_ARENA_MARK before calling |init| and JS_ARENA_RELEASE
 314      * after calling |close|.
 315      */
 316     TokenStream(JSContext *);
 317
 318     /*
 319      * Create a new token stream from an input buffer.
 320      * Return false on memory-allocation failure.
 321      */
 322     bool init(const jschar *base, size_t length, const char *filename, uintN lineno,
 323               JSVersion version);
 324     void close();
 325     ~TokenStream() {}
 326
 327     /* Accessors. */
 328     JSContext *getContext() const { return cx; }
 329     bool onCurrentLine(const TokenPos &pos) const { return lineno == pos.end.lineno; }
 330     const Token &currentToken() const { return tokens[cursor]; }
 331     const CharBuffer &getTokenbuf() const { return tokenbuf; }
 332     const char *getFilename() const { return filename; }
 333     uintN getLineno() const { return lineno; }
 334     /* Note that the version and hasXML can get out of sync via setXML. */
 335     JSVersion versionNumber() const { return VersionNumber(version); }
 336     JSVersion versionWithFlags() const { return version; }
 337     bool hasAnonFunFix() const { return VersionHasAnonFunFix(version); }
 338     bool hasXML() const { return xml || VersionShouldParseXML(versionNumber()); }
 339     void setXML(bool enabled) { xml = enabled; }
 340
 341     /* Flag methods. */
 342     void setStrictMode(bool enabled = true) { setFlag(enabled, TSF_STRICT_MODE_CODE); }
 343     void setXMLTagMode(bool enabled = true) { setFlag(enabled, TSF_XMLTAGMODE); }
 344     void setXMLOnlyMode(bool enabled = true) { setFlag(enabled, TSF_XMLONLYMODE); }
 345     void setUnexpectedEOF(bool enabled = true) { setFlag(enabled, TSF_UNEXPECTED_EOF); }
 346     void setOctalCharacterEscape(bool enabled = true) { setFlag(enabled, TSF_OCTAL_CHAR); }
 347
 348     bool isStrictMode() { return !!(flags & TSF_STRICT_MODE_CODE); }
 349     bool isXMLTagMode() { return !!(flags & TSF_XMLTAGMODE); }
 350     bool isXMLOnlyMode() { return !!(flags & TSF_XMLONLYMODE); }
 351     bool isUnexpectedEOF() { return !!(flags & TSF_UNEXPECTED_EOF); }
 352     bool isEOF() const { return !!(flags & TSF_EOF); }
 353     bool isError() const { return !!(flags & TSF_ERROR); }
 354     bool hasOctalCharacterEscape() const { return flags & TSF_OCTAL_CHAR; }
 355
 356     /* Mutators. */
 357     bool reportCompileErrorNumberVA(JSParseNode *pn, uintN flags, uintN errorNumber, va_list ap);
 358     void mungeCurrentToken(TokenKind newKind) { tokens[cursor].type = newKind; }
 359     void mungeCurrentToken(JSOp newOp) { tokens[cursor].t_op = newOp; }
 360     void mungeCurrentToken(TokenKind newKind, JSOp newOp) {
 361         mungeCurrentToken(newKind);
 362         mungeCurrentToken(newOp);
 363     }
 364
 365   private:
 366     static JSAtom *atomize(JSContext *cx, CharBuffer &cb);
 367
 368     /*
 369      * Enables flags in the associated tokenstream for the object lifetime.
 370      * Useful for lexically-scoped flag toggles.
 371      */
 372     class Flagger {
 373         TokenStream * const parent;
 374         uintN       flags;
 375       public:
 376         Flagger(TokenStream *parent, uintN withFlags) : parent(parent), flags(withFlags) {
 377             parent->flags |= flags;
 378         }
 379
 380         ~Flagger() { parent->flags &= ~flags; }
 381     };
 382     friend class Flagger;
 383
 384     void setFlag(bool enabled, TokenStreamFlags flag) {
 385         if (enabled)
 386             flags |= flag;
 387         else
 388             flags &= ~flag;
 389     }
 390
 391   public:
 392     /*
 393      * Get the next token from the stream, make it the current token, and
 394      * return its kind.
 395      */
 396     TokenKind getToken() {
 397         /* Check for a pushed-back token resulting from mismatching lookahead. */
 398         while (lookahead != 0) {
 399             JS_ASSERT(!(flags & TSF_XMLTEXTMODE));
 400             lookahead--;
 401             cursor = (cursor + 1) & ntokensMask;
 402             TokenKind tt = currentToken().type;
 403             JS_ASSERT(!(flags & TSF_NEWLINES));
 404             if (tt != TOK_EOL)
 405                 return tt;
 406         }
 407
 408         /* If there was a fatal error, keep returning TOK_ERROR. */
 409         if (flags & TSF_ERROR)
 410             return TOK_ERROR;
 411
 412         return getTokenInternal();
 413     }
 414
 415     /* Similar, but also sets flags. */
 416     TokenKind getToken(uintN withFlags) {
 417         Flagger flagger(this, withFlags);
 418         return getToken();
 419     }
 420
 421     /*
 422      * Push the last scanned token back into the stream.
 423      */
 424     void ungetToken() {
 425         JS_ASSERT(lookahead < ntokensMask);
 426         lookahead++;
 427         cursor = (cursor - 1) & ntokensMask;
 428     }
 429
 430     TokenKind peekToken(uintN withFlags = 0) {
 431         Flagger flagger(this, withFlags);
 432         if (lookahead != 0) {
 433             JS_ASSERT(lookahead == 1);
 434             return tokens[(cursor + lookahead) & ntokensMask].type;
 435         }
 436         TokenKind tt = getToken();
 437         ungetToken();
 438         return tt;
 439     }
 440
 441     TokenKind peekTokenSameLine(uintN withFlags = 0) {
 442         Flagger flagger(this, withFlags);
 443         if (!onCurrentLine(currentToken().pos))
 444             return TOK_EOL;
 445         TokenKind tt = peekToken(TSF_NEWLINES);
 446         return tt;
 447     }
 448
 449     /*
 450      * Get the next token from the stream if its kind is |tt|.
 451      */
 452     JSBool matchToken(TokenKind tt, uintN withFlags = 0) {
 453         Flagger flagger(this, withFlags);
 454         if (getToken() == tt)
 455             return JS_TRUE;
 456         ungetToken();
 457         return JS_FALSE;
 458     }
 459
 460   private:
 461     typedef struct TokenBuf {
 462         jschar              *base;      /* base of line or stream buffer */
 463         jschar              *limit;     /* limit for quick bounds check */
 464         jschar              *ptr;       /* next char to get, or slot to use */
 465     } TokenBuf;
 466
 467     TokenKind getTokenInternal();     /* doesn't check for pushback or error flag. */
 468
 469     int32 getChar();
 470     int32 getCharIgnoreEOL();
 471     void ungetChar(int32 c);
 472     void ungetCharIgnoreEOL(int32 c);
 473     Token *newToken(ptrdiff_t adjust);
 474     bool peekUnicodeEscape(int32 *c);
 475     bool matchUnicodeEscapeIdStart(int32 *c);
 476     bool matchUnicodeEscapeIdent(int32 *c);
 477     JSBool peekChars(intN n, jschar *cp);
 478     JSBool getXMLEntity();
 479     jschar *findEOL();
 480
 481     JSBool matchChar(int32 expect) {
 482         int32 c = getChar();
 483         if (c == expect)
 484             return JS_TRUE;
 485         ungetChar(c);
 486         return JS_FALSE;
 487     }
 488
 489     int32 peekChar() {
 490         int32 c = getChar();
 491         ungetChar(c);
 492         return c;
 493     }
 494
 495     void skipChars(intN n) {
 496         while (--n >= 0)
 497             getChar();
 498     }
 499
 500     JSContext           * const cx;
 501     Token               tokens[ntokens];/* circular token buffer */
 502     uintN               cursor;         /* index of last parsed token */
 503     uintN               lookahead;      /* count of lookahead tokens */
 504     uintN               lineno;         /* current line number */
 505     uintN               flags;          /* flags -- see above */
 506     jschar              *linebase;      /* start of current line;  points into userbuf */
 507     jschar              *prevLinebase;  /* start of previous line;  NULL if on the first line */
 508     TokenBuf            userbuf;        /* user input buffer */
 509     const char          *filename;      /* input filename or null */
 510     JSSourceHandler     listener;       /* callback for source; eg debugger */
 511     void                *listenerData;  /* listener 'this' data */
 512     void                *listenerTSData;/* listener data for this TokenStream */
 513     CharBuffer          tokenbuf;       /* current token string buffer */
 514     bool                maybeEOL[256];  /* probabilistic EOL lookup table */
 515     bool                maybeStrSpecial[256];/* speeds up string scanning */
 516     JSVersion           version;        /* (i.e. to identify keywords) */
 517     bool                xml;            /* see JSOPTION_XML */
 518 };
 519
 520 } /* namespace js */
 521
 522 /* Unicode separators that are treated as line terminators, in addition to \n, \r */
 523 #define LINE_SEPARATOR  0x2028
 524 #define PARA_SEPARATOR  0x2029
 525
 526 extern void
 527 js_CloseTokenStream(JSContext *cx, js::TokenStream *ts);
 528
 529 extern JS_FRIEND_API(int)
 530 js_fgets(char *buf, int size, FILE *file);
 531
 532 /*
 533  * If the given char array forms JavaScript keyword, return corresponding
 534  * token. Otherwise return TOK_EOF.
 535  */
 536 extern js::TokenKind
 537 js_CheckKeyword(const jschar *chars, size_t length);
 538
 539 /*
 540  * Friend-exported API entry point to call a mapping function on each reserved
 541  * identifier in the scanner's keyword table.
 542  */
 543 typedef void (*JSMapKeywordFun)(const char *);
 544
 545 /*
 546  * Check that str forms a valid JS identifier name. The function does not
 547  * check if str is a JS keyword.
 548  */
 549 extern JSBool
 550 js_IsIdentifier(JSLinearString *str);
 551
 552 /*
 553  * Steal one JSREPORT_* bit (see jsapi.h) to tell that arguments to the error
 554  * message have const jschar* type, not const char*.
 555  */
 556 #define JSREPORT_UC 0x100
 557
 558 namespace js {
 559
 560 /*
 561  * Report a compile-time error by its number. Return true for a warning, false
 562  * for an error. When pn is not null, use it to report error's location.
 563  * Otherwise use ts, which must not be null.
 564  */
 565 bool
 566 ReportCompileErrorNumber(JSContext *cx, TokenStream *ts, JSParseNode *pn, uintN flags,
 567                          uintN errorNumber, ...);
 568
 569 /*
 570  * Report a condition that should elicit a warning with JSOPTION_STRICT,
 571  * or an error if ts or tc is handling strict mode code.  This function
 572  * defers to ReportCompileErrorNumber to do the real work.  Either tc
 573  * or ts may be NULL, if there is no tree context or token stream state
 574  * whose strictness should affect the report.
 575  *
 576  * One could have ReportCompileErrorNumber recognize the
 577  * JSREPORT_STRICT_MODE_ERROR flag instead of having a separate function
 578  * like this one.  However, the strict mode code flag we need to test is
 579  * in the JSTreeContext structure for that code; we would have to change
 580  * the ~120 ReportCompileErrorNumber calls to pass the additional
 581  * argument, even though many of those sites would never use it.  Using
 582  * ts's TSF_STRICT_MODE_CODE flag instead of tc's would be brittle: at some
 583  * points ts's flags don't correspond to those of the tc relevant to the
 584  * error.
 585  */
 586 bool
 587 ReportStrictModeError(JSContext *cx, TokenStream *ts, JSTreeContext *tc, JSParseNode *pn,
 588                       uintN errorNumber, ...);
 589
 590 } /* namespace js */
 591
 592 #endif /* jsscan_h___ */