NEWS

   1 Bison News
   2 ----------
   3
   4 Changes in version 2.1a:
   5
   6 * New warning: unused values
   7   Typed right-hand side symbols whose value are not used are reported.
   8   For instance:
   9
  10      exp: exp "?" exp ":" exp { $1 ? $1 : $3; }
  11         | exp "+" exp
  12         ;
  13
  14   will trigger a warning about $$ and $5 in the first rule, and $3 in
  15   the second ($1 is copied to $$ by the default rule).  This example
  16   most likely contains three errors, and should be rewritten as:
  17
  18      exp: exp "?" exp ":" exp { $$ = $1 ? $3 : $5; }
  19         | exp "+" exp         { $$ = $1 + $3; }
  20         ;
  21
  22   However, if the original actions were really intended, the warnings
  23   can be suppressed by letting Bison believe the values are used, e.g.:
  24
  25      exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); }
  26         | exp "+" exp         { $$ = $1; (void) $3; }
  27         ;
  28
  29   If there are mid-rule actions, the warning is issued if no action
  30   uses it.  The following triggers no warning: $1 and $3 are used.
  31
  32      exp: exp { push ($1); } '+' exp { push ($3); sum (); };
  33
  34   Mid-rule actions that use $$ cause the corresponding value to be
  35   set, therefore the following action must use it.  The following rule
  36   triggers a warning about $2.
  37
  38      exp: '1' { $$ = 1; } '+' exp { $$ = $1 + $4; };
  39
  40   The warning is intended to help catching lost values and memory leaks.
  41   If a value is ignored, its associated memory typically is not reclaimed.
  42
  43 * %destructor vs. YYABORT, YYACCEPT, and YYERROR.
  44   Destructors are now called when user code invokes YYABORT, YYACCEPT,
  45   and YYERROR, for all objects on the stack, other than objects
  46   corresponding to the right-hand side of the current rule.
  47
  48 * %expect, %expect-rr
  49   Incorrect numbers of expected conflicts are now actual errors,
  50   instead of warnings.
  51
  52 * GLR, YACC parsers.
  53   The %parse-params are available in the %destructor's (and the
  54   experimental %printer's) as per the documentation.
  55
  56 * Bison now warns if it finds a stray `$' or `@' in an action.
  57
  58 * %require "VERSION"
  59   To specify that the grammar file depends on features implemented in
  60   Bison version VERSION or higher.
  61
  62 * lalr1.cc: The token and value types are now class members.
  63   The tokens were defined as free form enums and cpp macros.  YYSTYPE
  64   was defined as a free form union.  They are now class members:
  65   tokens are enumerations of the `yy::parser::token' struct, and the
  66   semantic values have the `yy::parser::semantic_type' type.
  67
  68   If you do not want or can update to this scheme, the directive
  69   `%define "global_tokens_and_yystype" "1"' triggers the global
  70   definition of tokens and YYSTYPE.  This change is suitable both
  71   for previous releases of Bison, and this one.
  72
  73   If you wish to update, then make sure older version of Bison will
  74   fail using `%require "2.1a"'.
  75
  76 * DJGPP support added.
  77
  78 Changes in version 2.1, 2005-09-16:
  79
  80 * The C++ lalr1.cc skeleton supports %lex-param.
  81
  82 * Bison-generated parsers now support the translation of diagnostics like
  83   "syntax error" into languages other than English.  The default
  84   language is still English.  For details, please see the new
  85   Internationalization section of the Bison manual.  Software
  86   distributors should also see the new PACKAGING file.  Thanks to
  87   Bruno Haible for this new feature.
  88
  89 * Wording in the Bison-generated parsers has been changed slightly to
  90   simplify translation.  In particular, the message "memory exhausted"
  91   has replaced "parser stack overflow", as the old message was not
  92   always accurate for modern Bison-generated parsers.
  93
  94 * Destructors are now called when the parser aborts, for all symbols left
  95   behind on the stack.  Also, the start symbol is now destroyed after a
  96   successful parse.  In both cases, the behavior was formerly inconsistent.
  97
  98 * When generating verbose diagnostics, Bison-generated parsers no longer
  99   quote the literal strings associated with tokens.  For example, for
 100   a syntax error associated with '%token NUM "number"' they might
 101   print 'syntax error, unexpected number' instead of 'syntax error,
 102   unexpected "number"'.
 103
 104 Changes in version 2.0, 2004-12-25:
 105
 106 * Possibly-incompatible changes
 107
 108   - Bison-generated parsers no longer default to using the alloca function
 109     (when available) to extend the parser stack, due to widespread
 110     problems in unchecked stack-overflow detection.  You can "#define
 111     YYSTACK_USE_ALLOCA 1" to require the use of alloca, but please read
 112     the manual to determine safe values for YYMAXDEPTH in that case.
 113
 114   - Error token location.
 115     During error recovery, the location of the syntax error is updated
 116     to cover the whole sequence covered by the error token: it includes
 117     the shifted symbols thrown away during the first part of the error
 118     recovery, and the lookahead rejected during the second part.
 119
 120   - Semicolon changes:
 121     . Stray semicolons are no longer allowed at the start of a grammar.
 122     . Semicolons are now required after in-grammar declarations.
 123
 124   - Unescaped newlines are no longer allowed in character constants or
 125     string literals.  They were never portable, and GCC 3.4.0 has
 126     dropped support for them.  Better diagnostics are now generated if
 127     forget a closing quote.
 128
 129   - NUL bytes are no longer allowed in Bison string literals, unfortunately.
 130
 131 * New features
 132
 133   - GLR grammars now support locations.
 134
 135   - New directive: %initial-action.
 136     This directive allows the user to run arbitrary code (including
 137     initializing @$) from yyparse before parsing starts.
 138
 139   - A new directive "%expect-rr N" specifies the expected number of
 140     reduce/reduce conflicts in GLR parsers.
 141
 142   - %token numbers can now be hexadecimal integers, e.g., `%token FOO 0x12d'.
 143     This is a GNU extension.
 144
 145   - The option `--report=lookahead' was changed to `--report=look-ahead'.
 146     The old spelling still works, but is not documented and will be
 147     removed.
 148
 149   - Experimental %destructor support has been added to lalr1.cc.
 150
 151   - New configure option --disable-yacc, to disable installation of the
 152     yacc command and -ly library introduced in 1.875 for POSIX conformance.
 153
 154 * Bug fixes
 155
 156   - For now, %expect-count violations are now just warnings, not errors.
 157     This is for compatibility with Bison 1.75 and earlier (when there are
 158     reduce/reduce conflicts) and with Bison 1.30 and earlier (when there
 159     are too many or too few shift/reduce conflicts).  However, in future
 160     versions of Bison we plan to improve the %expect machinery so that
 161     these violations will become errors again.
 162
 163   - Within Bison itself, numbers (e.g., goto numbers) are no longer
 164     arbitrarily limited to 16-bit counts.
 165
 166   - Semicolons are now allowed before "|" in grammar rules, as POSIX requires.
 167 \f
 168 Changes in version 1.875, 2003-01-01:
 169
 170 * The documentation license has been upgraded to version 1.2
 171   of the GNU Free Documentation License.
 172
 173 * syntax error processing
 174
 175   - In Yacc-style parsers YYLLOC_DEFAULT is now used to compute error
 176     locations too.  This fixes bugs in error-location computation.
 177
 178   - %destructor
 179     It is now possible to reclaim the memory associated to symbols
 180     discarded during error recovery.  This feature is still experimental.
 181
 182   - %error-verbose
 183     This new directive is preferred over YYERROR_VERBOSE.
 184
 185   - #defining yyerror to steal internal variables is discouraged.
 186     It is not guaranteed to work forever.
 187
 188 * POSIX conformance
 189
 190   - Semicolons are once again optional at the end of grammar rules.
 191     This reverts to the behavior of Bison 1.33 and earlier, and improves
 192     compatibility with Yacc.
 193
 194   - `parse error' -> `syntax error'
 195     Bison now uniformly uses the term `syntax error'; formerly, the code
 196     and manual sometimes used the term `parse error' instead.  POSIX
 197     requires `syntax error' in diagnostics, and it was thought better to
 198     be consistent.
 199
 200   - The documentation now emphasizes that yylex and yyerror must be
 201     declared before use.  C99 requires this.
 202
 203   - Bison now parses C99 lexical constructs like UCNs and
 204     backslash-newline within C escape sequences, as POSIX 1003.1-2001 requires.
 205
 206   - File names are properly escaped in C output.  E.g., foo\bar.y is
 207     output as "foo\\bar.y".
 208
 209   - Yacc command and library now available
 210     The Bison distribution now installs a `yacc' command, as POSIX requires.
 211     Also, Bison now installs a small library liby.a containing
 212     implementations of Yacc-compatible yyerror and main functions.
 213     This library is normally not useful, but POSIX requires it.
 214
 215   - Type clashes now generate warnings, not errors.
 216
 217   - If the user does not define YYSTYPE as a macro, Bison now declares it
 218     using typedef instead of defining it as a macro.
 219     For consistency, YYLTYPE is also declared instead of defined.
 220
 221 * Other compatibility issues
 222
 223   - %union directives can now have a tag before the `{', e.g., the
 224     directive `%union foo {...}' now generates the C code
 225     `typedef union foo { ... } YYSTYPE;'; this is for Yacc compatibility.
 226     The default union tag is `YYSTYPE', for compatibility with Solaris 9 Yacc.
 227     For consistency, YYLTYPE's struct tag is now `YYLTYPE' not `yyltype'.
 228     This is for compatibility with both Yacc and Bison 1.35.
 229
 230   - `;' is output before the terminating `}' of an action, for
 231     compatibility with Bison 1.35.
 232
 233   - Bison now uses a Yacc-style format for conflict reports, e.g.,
 234     `conflicts: 2 shift/reduce, 1 reduce/reduce'.
 235
 236   - `yystype' and `yyltype' are now obsolescent macros instead of being
 237     typedefs or tags; they are no longer documented and are planned to be
 238     withdrawn in a future release.
 239
 240 * GLR parser notes
 241
 242   - GLR and inline
 243     Users of Bison have to decide how they handle the portability of the
 244     C keyword `inline'.
 245
 246   - `parsing stack overflow...' -> `parser stack overflow'
 247     GLR parsers now report `parser stack overflow' as per the Bison manual.
 248
 249 * Bison now warns if it detects conflicting outputs to the same file,
 250   e.g., it generates a warning for `bison -d -o foo.h foo.y' since
 251   that command outputs both code and header to foo.h.
 252
 253 * #line in output files
 254   - --no-line works properly.
 255
 256 * Bison can no longer be built by a K&R C compiler; it requires C89 or
 257   later to be built.  This change originally took place a few versions
 258   ago, but nobody noticed until we recently asked someone to try
 259   building Bison with a K&R C compiler.
 260 \f
 261 Changes in version 1.75, 2002-10-14:
 262
 263 * Bison should now work on 64-bit hosts.
 264
 265 * Indonesian translation thanks to Tedi Heriyanto.
 266
 267 * GLR parsers
 268   Fix spurious parse errors.
 269
 270 * Pure parsers
 271   Some people redefine yyerror to steal yyparse' private variables.
 272   Reenable this trick until an official feature replaces it.
 273
 274 * Type Clashes
 275   In agreement with POSIX and with other Yaccs, leaving a default
 276   action is valid when $$ is untyped, and $1 typed:
 277
 278         untyped: ... typed;
 279
 280   but the converse remains an error:
 281
 282         typed: ... untyped;
 283
 284 * Values of mid-rule actions
 285   The following code:
 286
 287         foo: { ... } { $$ = $1; } ...
 288
 289   was incorrectly rejected: $1 is defined in the second mid-rule
 290   action, and is equal to the $$ of the first mid-rule action.
 291 \f
 292 Changes in version 1.50, 2002-10-04:
 293
 294 * GLR parsing
 295   The declaration
 296      %glr-parser
 297   causes Bison to produce a Generalized LR (GLR) parser, capable of handling
 298   almost any context-free grammar, ambiguous or not.  The new declarations
 299   %dprec and %merge on grammar rules allow parse-time resolution of
 300   ambiguities.  Contributed by Paul Hilfinger.
 301
 302   Unfortunately Bison 1.50 does not work properly on 64-bit hosts
 303   like the Alpha, so please stick to 32-bit hosts for now.
 304
 305 * Output Directory
 306   When not in Yacc compatibility mode, when the output file was not
 307   specified, running `bison foo/bar.y' created `foo/bar.c'.  It
 308   now creates `bar.c'.
 309
 310 * Undefined token
 311   The undefined token was systematically mapped to 2 which prevented
 312   the use of 2 by the user.  This is no longer the case.
 313
 314 * Unknown token numbers
 315   If yylex returned an out of range value, yyparse could die.  This is
 316   no longer the case.
 317
 318 * Error token
 319   According to POSIX, the error token must be 256.
 320   Bison extends this requirement by making it a preference: *if* the
 321   user specified that one of her tokens is numbered 256, then error
 322   will be mapped onto another number.
 323
 324 * Verbose error messages
 325   They no longer report `..., expecting error or...' for states where
 326   error recovery is possible.
 327
 328 * End token
 329   Defaults to `$end' instead of `$'.
 330
 331 * Error recovery now conforms to documentation and to POSIX
 332   When a Bison-generated parser encounters a syntax error, it now pops
 333   the stack until it finds a state that allows shifting the error
 334   token.  Formerly, it popped the stack until it found a state that
 335   allowed some non-error action other than a default reduction on the
 336   error token.  The new behavior has long been the documented behavior,
 337   and has long been required by POSIX.  For more details, please see
 338   Paul Eggert, "Reductions during Bison error handling" (2002-05-20)
 339   <http://lists.gnu.org/archive/html/bug-bison/2002-05/msg00038.html>.
 340
 341 * Traces
 342   Popped tokens and nonterminals are now reported.
 343
 344 * Larger grammars
 345   Larger grammars are now supported (larger token numbers, larger grammar
 346   size (= sum of the LHS and RHS lengths), larger LALR tables).
 347   Formerly, many of these numbers ran afoul of 16-bit limits;
 348   now these limits are 32 bits on most hosts.
 349
 350 * Explicit initial rule
 351   Bison used to play hacks with the initial rule, which the user does
 352   not write.  It is now explicit, and visible in the reports and
 353   graphs as rule 0.
 354
 355 * Useless rules
 356   Before, Bison reported the useless rules, but, although not used,
 357   included them in the parsers.  They are now actually removed.
 358
 359 * Useless rules, useless nonterminals
 360   They are now reported, as a warning, with their locations.
 361
 362 * Rules never reduced
 363   Rules that can never be reduced because of conflicts are now
 364   reported.
 365
 366 * Incorrect `Token not used'
 367   On a grammar such as
 368
 369            %token useless useful
 370            %%
 371            exp: '0' %prec useful;
 372
 373   where a token was used to set the precedence of the last rule,
 374   bison reported both `useful' and `useless' as useless tokens.
 375
 376 * Revert the C++ namespace changes introduced in 1.31
 377   as they caused too many portability hassles.
 378
 379 * Default locations
 380   By an accident of design, the default computation of @$ was
 381   performed after another default computation was performed: @$ = @1.
 382   The latter is now removed: YYLLOC_DEFAULT is fully responsible of
 383   the computation of @$.
 384
 385 * Token end-of-file
 386   The token end of file may be specified by the user, in which case,
 387   the user symbol is used in the reports, the graphs, and the verbose
 388   error messages instead of `$end', which remains being the default.
 389   For instance
 390      %token MYEOF 0
 391   or
 392      %token MYEOF 0 "end of file"
 393
 394 * Semantic parser
 395   This old option, which has been broken for ages, is removed.
 396
 397 * New translations
 398   Brazilian Portuguese, thanks to Alexandre Folle de Menezes.
 399   Croatian, thanks to Denis Lackovic.
 400
 401 * Incorrect token definitions
 402   When given `%token 'a' "A"', Bison used to output `#define 'a' 65'.
 403
 404 * Token definitions as enums
 405   Tokens are output both as the traditional #define's, and, provided
 406   the compiler supports ANSI C or is a C++ compiler, as enums.
 407   This lets debuggers display names instead of integers.
 408
 409 * Reports
 410   In addition to --verbose, bison supports --report=THINGS, which
 411   produces additional information:
 412   - itemset
 413     complete the core item sets with their closure
 414   - lookahead [changed to `look-ahead' in 1.875e and later]
 415     explicitly associate look-ahead tokens to items
 416   - solved
 417     describe shift/reduce conflicts solving.
 418     Bison used to systematically output this information on top of
 419     the report.  Solved conflicts are now attached to their states.
 420
 421 * Type clashes
 422   Previous versions don't complain when there is a type clash on
 423   the default action if the rule has a mid-rule action, such as in:
 424
 425       %type <foo> bar
 426       %%
 427       bar: '0' {} '0';
 428
 429   This is fixed.
 430
 431 * GNU M4 is now required when using Bison.
 432 \f
 433 Changes in version 1.35, 2002-03-25:
 434
 435 * C Skeleton
 436   Some projects use Bison's C parser with C++ compilers, and define
 437   YYSTYPE as a class.  The recent adjustment of C parsers for data
 438   alignment and 64 bit architectures made this impossible.
 439
 440   Because for the time being no real solution for C++ parser
 441   generation exists, kludges were implemented in the parser to
 442   maintain this use.  In the future, when Bison has C++ parsers, this
 443   kludge will be disabled.
 444
 445   This kludge also addresses some C++ problems when the stack was
 446   extended.
 447 \f
 448 Changes in version 1.34, 2002-03-12:
 449
 450 * File name clashes are detected
 451   $ bison foo.y -d -o foo.x
 452   fatal error: header and parser would both be named `foo.x'
 453
 454 * A missing `;' at the end of a rule triggers a warning
 455   In accordance with POSIX, and in agreement with other
 456   Yacc implementations, Bison will mandate this semicolon in the near
 457   future.  This eases the implementation of a Bison parser of Bison
 458   grammars by making this grammar LALR(1) instead of LR(2).  To
 459   facilitate the transition, this release introduces a warning.
 460
 461 * Revert the C++ namespace changes introduced in 1.31, as they caused too
 462   many portability hassles.
 463
 464 * DJGPP support added.
 465
 466 * Fix test suite portability problems.
 467 \f
 468 Changes in version 1.33, 2002-02-07:
 469
 470 * Fix C++ issues
 471   Groff could not be compiled for the definition of size_t was lacking
 472   under some conditions.
 473
 474 * Catch invalid @n
 475   As is done with $n.
 476 \f
 477 Changes in version 1.32, 2002-01-23:
 478
 479 * Fix Yacc output file names
 480
 481 * Portability fixes
 482
 483 * Italian, Dutch translations
 484 \f
 485 Changes in version 1.31, 2002-01-14:
 486
 487 * Many Bug Fixes
 488
 489 * GNU Gettext and %expect
 490   GNU Gettext asserts 10 s/r conflicts, but there are 7.  Now that
 491   Bison dies on incorrect %expectations, we fear there will be
 492   too many bug reports for Gettext, so _for the time being_, %expect
 493   does not trigger an error when the input file is named `plural.y'.
 494
 495 * Use of alloca in parsers
 496   If YYSTACK_USE_ALLOCA is defined to 0, then the parsers will use
 497   malloc exclusively.  Since 1.29, but was not NEWS'ed.
 498
 499   alloca is used only when compiled with GCC, to avoid portability
 500   problems as on AIX.
 501
 502 * yyparse now returns 2 if memory is exhausted; formerly it dumped core.
 503
 504 * When the generated parser lacks debugging code, YYDEBUG is now 0
 505   (as POSIX requires) instead of being undefined.
 506
 507 * User Actions
 508   Bison has always permitted actions such as { $$ = $1 }: it adds the
 509   ending semicolon.  Now if in Yacc compatibility mode, the semicolon
 510   is no longer output: one has to write { $$ = $1; }.
 511
 512 * Better C++ compliance
 513   The output parsers try to respect C++ namespaces.
 514   [This turned out to be a failed experiment, and it was reverted later.]
 515
 516 * Reduced Grammars
 517   Fixed bugs when reporting useless nonterminals.
 518
 519 * 64 bit hosts
 520   The parsers work properly on 64 bit hosts.
 521
 522 * Error messages
 523   Some calls to strerror resulted in scrambled or missing error messages.
 524
 525 * %expect
 526   When the number of shift/reduce conflicts is correct, don't issue
 527   any warning.
 528
 529 * The verbose report includes the rule line numbers.
 530
 531 * Rule line numbers are fixed in traces.
 532
 533 * Swedish translation
 534
 535 * Parse errors
 536   Verbose parse error messages from the parsers are better looking.
 537   Before: parse error: unexpected `'/'', expecting `"number"' or `'-'' or `'(''
 538      Now: parse error: unexpected '/', expecting "number" or '-' or '('
 539
 540 * Fixed parser memory leaks.
 541   When the generated parser was using malloc to extend its stacks, the
 542   previous allocations were not freed.
 543
 544 * Fixed verbose output file.
 545   Some newlines were missing.
 546   Some conflicts in state descriptions were missing.
 547
 548 * Fixed conflict report.
 549   Option -v was needed to get the result.
 550
 551 * %expect
 552   Was not used.
 553   Mismatches are errors, not warnings.
 554
 555 * Fixed incorrect processing of some invalid input.
 556
 557 * Fixed CPP guards: 9foo.h uses BISON_9FOO_H instead of 9FOO_H.
 558
 559 * Fixed some typos in the documentation.
 560
 561 * %token MY_EOF 0 is supported.
 562   Before, MY_EOF was silently renumbered as 257.
 563
 564 * doc/refcard.tex is updated.
 565
 566 * %output, %file-prefix, %name-prefix.
 567   New.
 568
 569 * --output
 570   New, aliasing `--output-file'.
 571 \f
 572 Changes in version 1.30, 2001-10-26:
 573
 574 * `--defines' and `--graph' have now an optional argument which is the
 575   output file name. `-d' and `-g' do not change; they do not take any
 576   argument.
 577
 578 * `%source_extension' and `%header_extension' are removed, failed
 579   experiment.
 580
 581 * Portability fixes.
 582 \f
 583 Changes in version 1.29, 2001-09-07:
 584
 585 * The output file does not define const, as this caused problems when used
 586   with common autoconfiguration schemes.  If you still use ancient compilers
 587   that lack const, compile with the equivalent of the C compiler option
 588   `-Dconst='.  autoconf's AC_C_CONST macro provides one way to do this.
 589
 590 * Added `-g' and `--graph'.
 591
 592 * The Bison manual is now distributed under the terms of the GNU FDL.
 593
 594 * The input and the output files has automatically a similar extension.
 595
 596 * Russian translation added.
 597
 598 * NLS support updated; should hopefully be less troublesome.
 599
 600 * Added the old Bison reference card.
 601
 602 * Added `--locations' and `%locations'.
 603
 604 * Added `-S' and `--skeleton'.
 605
 606 * `%raw', `-r', `--raw' is disabled.
 607
 608 * Special characters are escaped when output.  This solves the problems
 609   of the #line lines with path names including backslashes.
 610
 611 * New directives.
 612   `%yacc', `%fixed_output_files', `%defines', `%no_parser', `%verbose',
 613   `%debug', `%source_extension' and `%header_extension'.
 614
 615 * @$
 616   Automatic location tracking.
 617 \f
 618 Changes in version 1.28, 1999-07-06:
 619
 620 * Should compile better now with K&R compilers.
 621
 622 * Added NLS.
 623
 624 * Fixed a problem with escaping the double quote character.
 625
 626 * There is now a FAQ.
 627 \f
 628 Changes in version 1.27:
 629
 630 * The make rule which prevented bison.simple from being created on
 631   some systems has been fixed.
 632 \f
 633 Changes in version 1.26:
 634
 635 * Bison now uses automake.
 636
 637 * New mailing lists: <bug-bison@gnu.org> and <help-bison@gnu.org>.
 638
 639 * Token numbers now start at 257 as previously documented, not 258.
 640
 641 * Bison honors the TMPDIR environment variable.
 642
 643 * A couple of buffer overruns have been fixed.
 644
 645 * Problems when closing files should now be reported.
 646
 647 * Generated parsers should now work even on operating systems which do
 648   not provide alloca().
 649 \f
 650 Changes in version 1.25, 1995-10-16:
 651
 652 * Errors in the input grammar are not fatal; Bison keeps reading
 653 the grammar file, and reports all the errors found in it.
 654
 655 * Tokens can now be specified as multiple-character strings: for
 656 example, you could use "<=" for a token which looks like <=, instead
 657 of chosing a name like LESSEQ.
 658
 659 * The %token_table declaration says to write a table of tokens (names
 660 and numbers) into the parser file.  The yylex function can use this
 661 table to recognize multiple-character string tokens, or for other
 662 purposes.
 663
 664 * The %no_lines declaration says not to generate any #line preprocessor
 665 directives in the parser file.
 666
 667 * The %raw declaration says to use internal Bison token numbers, not
 668 Yacc-compatible token numbers, when token names are defined as macros.
 669
 670 * The --no-parser option produces the parser tables without including
 671 the parser engine; a project can now use its own parser engine.
 672 The actions go into a separate file called NAME.act, in the form of
 673 a switch statement body.
 674 \f
 675 Changes in version 1.23:
 676
 677 The user can define YYPARSE_PARAM as the name of an argument to be
 678 passed into yyparse.  The argument should have type void *.  It should
 679 actually point to an object.  Grammar actions can access the variable
 680 by casting it to the proper pointer type.
 681
 682 Line numbers in output file corrected.
 683 \f
 684 Changes in version 1.22:
 685
 686 --help option added.
 687 \f
 688 Changes in version 1.20:
 689
 690 Output file does not redefine const for C++.
 691
 692 Local Variables:
 693 mode: outline
 694 End:
 695
 696 -----
 697
 698 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
 699 Free Software Foundation, Inc.
 700
 701 This file is part of Bison, the GNU Compiler Compiler.
 702
 703 Bison is free software; you can redistribute it and/or modify
 704 it under the terms of the GNU General Public License as published by
 705 the Free Software Foundation; either version 2, or (at your option)
 706 any later version.
 707
 708 Bison is distributed in the hope that it will be useful,
 709 but WITHOUT ANY WARRANTY; without even the implied warranty of
 710 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 711 GNU General Public License for more details.
 712
 713 You should have received a copy of the GNU General Public License
 714 along with autoconf; see the file COPYING.  If not, write to
 715 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 716 Boston, MA 02110-1301, USA.