]> git.saurik.com Git - bison.git/blame - NEWS
Add it for real.
[bison.git] / NEWS
CommitLineData
6780ca7a
DM
1Bison News
2----------
3af4feb2 3
4ad3ed84
PE
4Changes in version 2.3, 2006-06-05:
5
6* GLR grammars should now use `YYRECOVERING ()' instead of `YYRECOVERING',
7 for compatibility with LALR(1) grammars.
8
9* It is now documented that any definition of YYSTYPE or YYLTYPE should
10 be to a type name that does not contain parentheses or brackets.
11
ab8d9dc5 12Changes in version 2.2, 2006-05-19:
193d7c70
PE
13
14* The distribution terms for all Bison-generated parsers now permit
15 using the parsers in nonfree programs. Previously, this permission
16 was granted only for Bison-generated LALR(1) parsers in C.
5f4236a0 17
aa08666d
AD
18* %name-prefix changes the namespace name in C++ outputs.
19
20* The C++ parsers export their token_type.
5f4236a0 21
d6ca7905
PE
22* Bison now allows multiple %union declarations, and concatenates
23 their contents together.
24
affac613 25* New warning: unused values
4d7bc38c
PE
26 Right-hand side symbols whose values are not used are reported,
27 if the symbols have destructors. For instance:
affac613 28
8f3596a6 29 exp: exp "?" exp ":" exp { $1 ? $1 : $3; }
721be13c
PE
30 | exp "+" exp
31 ;
affac613 32
8f3596a6
AD
33 will trigger a warning about $$ and $5 in the first rule, and $3 in
34 the second ($1 is copied to $$ by the default rule). This example
4e26c69e 35 most likely contains three errors, and could be rewritten as:
affac613 36
4e26c69e
PE
37 exp: exp "?" exp ":" exp
38 { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); }
39 | exp "+" exp
40 { $$ = $1 ? $1 : $3; if ($1) free ($3); }
721be13c 41 ;
affac613 42
4e26c69e
PE
43 However, if the original actions were really intended, memory leaks
44 and all, the warnings can be suppressed by letting Bison believe the
45 values are used, e.g.:
721be13c 46
8f3596a6 47 exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); }
721be13c
PE
48 | exp "+" exp { $$ = $1; (void) $3; }
49 ;
50
84866159
AD
51 If there are mid-rule actions, the warning is issued if no action
52 uses it. The following triggers no warning: $1 and $3 are used.
53
54 exp: exp { push ($1); } '+' exp { push ($3); sum (); };
55
721be13c
PE
56 The warning is intended to help catching lost values and memory leaks.
57 If a value is ignored, its associated memory typically is not reclaimed.
affac613 58
9d9b8b70
PE
59* %destructor vs. YYABORT, YYACCEPT, and YYERROR.
60 Destructors are now called when user code invokes YYABORT, YYACCEPT,
61 and YYERROR, for all objects on the stack, other than objects
62 corresponding to the right-hand side of the current rule.
a85284cf 63
035aa4a0
PE
64* %expect, %expect-rr
65 Incorrect numbers of expected conflicts are now actual errors,
66 instead of warnings.
67
4b367315 68* GLR, YACC parsers.
4e26c69e
PE
69 The %parse-params are available in the destructors (and the
70 experimental printers) as per the documentation.
4b367315 71
302c0aee 72* Bison now warns if it finds a stray `$' or `@' in an action.
ad6a9b97 73
b50d2359 74* %require "VERSION"
4e26c69e
PE
75 This specifies that the grammar file depends on features implemented
76 in Bison version VERSION or higher.
b50d2359 77
fb9712a9 78* lalr1.cc: The token and value types are now class members.
e14d0ab6
AD
79 The tokens were defined as free form enums and cpp macros. YYSTYPE
80 was defined as a free form union. They are now class members:
fb9712a9
AD
81 tokens are enumerations of the `yy::parser::token' struct, and the
82 semantic values have the `yy::parser::semantic_type' type.
83
84 If you do not want or can update to this scheme, the directive
85 `%define "global_tokens_and_yystype" "1"' triggers the global
b50d2359
AD
86 definition of tokens and YYSTYPE. This change is suitable both
87 for previous releases of Bison, and this one.
fb9712a9 88
b50d2359 89 If you wish to update, then make sure older version of Bison will
ab8d9dc5 90 fail using `%require "2.2"'.
fb9712a9 91
302c0aee 92* DJGPP support added.
193d7c70 93\f
1bd0deda 94Changes in version 2.1, 2005-09-16:
1ce59070 95
e14d0ab6
AD
96* The C++ lalr1.cc skeleton supports %lex-param.
97
a7db4add 98* Bison-generated parsers now support the translation of diagnostics like
baf785db
PE
99 "syntax error" into languages other than English. The default
100 language is still English. For details, please see the new
0410a6e0
PE
101 Internationalization section of the Bison manual. Software
102 distributors should also see the new PACKAGING file. Thanks to
103 Bruno Haible for this new feature.
1ce59070 104
1a059451
PE
105* Wording in the Bison-generated parsers has been changed slightly to
106 simplify translation. In particular, the message "memory exhausted"
107 has replaced "parser stack overflow", as the old message was not
108 always accurate for modern Bison-generated parsers.
109
258b75ca
PE
110* Destructors are now called when the parser aborts, for all symbols left
111 behind on the stack. Also, the start symbol is now destroyed after a
112 successful parse. In both cases, the behavior was formerly inconsistent.
113
a7db4add 114* When generating verbose diagnostics, Bison-generated parsers no longer
72f000b0
PE
115 quote the literal strings associated with tokens. For example, for
116 a syntax error associated with '%token NUM "number"' they might
117 print 'syntax error, unexpected number' instead of 'syntax error,
118 unexpected "number"'.
193d7c70 119\f
82de6b0d 120Changes in version 2.0, 2004-12-25:
efeed023 121
82de6b0d 122* Possibly-incompatible changes
d7e14fc0 123
82de6b0d
PE
124 - Bison-generated parsers no longer default to using the alloca function
125 (when available) to extend the parser stack, due to widespread
126 problems in unchecked stack-overflow detection. You can "#define
127 YYSTACK_USE_ALLOCA 1" to require the use of alloca, but please read
128 the manual to determine safe values for YYMAXDEPTH in that case.
8dd162d3 129
82de6b0d
PE
130 - Error token location.
131 During error recovery, the location of the syntax error is updated
132 to cover the whole sequence covered by the error token: it includes
133 the shifted symbols thrown away during the first part of the error
134 recovery, and the lookahead rejected during the second part.
18d192f0 135
82de6b0d
PE
136 - Semicolon changes:
137 . Stray semicolons are no longer allowed at the start of a grammar.
138 . Semicolons are now required after in-grammar declarations.
e342c3be 139
82de6b0d
PE
140 - Unescaped newlines are no longer allowed in character constants or
141 string literals. They were never portable, and GCC 3.4.0 has
142 dropped support for them. Better diagnostics are now generated if
143 forget a closing quote.
8dd162d3 144
82de6b0d 145 - NUL bytes are no longer allowed in Bison string literals, unfortunately.
f74b6f91 146
82de6b0d 147* New features
1452af69 148
82de6b0d 149 - GLR grammars now support locations.
4febdd96 150
82de6b0d
PE
151 - New directive: %initial-action.
152 This directive allows the user to run arbitrary code (including
153 initializing @$) from yyparse before parsing starts.
1452af69 154
82de6b0d
PE
155 - A new directive "%expect-rr N" specifies the expected number of
156 reduce/reduce conflicts in GLR parsers.
1452af69 157
82de6b0d
PE
158 - %token numbers can now be hexadecimal integers, e.g., `%token FOO 0x12d'.
159 This is a GNU extension.
4febdd96 160
82de6b0d
PE
161 - The option `--report=lookahead' was changed to `--report=look-ahead'.
162 The old spelling still works, but is not documented and will be
163 removed.
1452af69 164
82de6b0d 165 - Experimental %destructor support has been added to lalr1.cc.
1452af69 166
82de6b0d
PE
167 - New configure option --disable-yacc, to disable installation of the
168 yacc command and -ly library introduced in 1.875 for POSIX conformance.
6040d338 169
82de6b0d 170* Bug fixes
d5a3fe37 171
82de6b0d
PE
172 - For now, %expect-count violations are now just warnings, not errors.
173 This is for compatibility with Bison 1.75 and earlier (when there are
174 reduce/reduce conflicts) and with Bison 1.30 and earlier (when there
175 are too many or too few shift/reduce conflicts). However, in future
176 versions of Bison we plan to improve the %expect machinery so that
177 these violations will become errors again.
3473d0f8 178
82de6b0d
PE
179 - Within Bison itself, numbers (e.g., goto numbers) are no longer
180 arbitrarily limited to 16-bit counts.
d600ee67 181
82de6b0d 182 - Semicolons are now allowed before "|" in grammar rules, as POSIX requires.
d600ee67 183\f
dc546b0f 184Changes in version 1.875, 2003-01-01:
963fcc17 185
dc546b0f
PE
186* The documentation license has been upgraded to version 1.2
187 of the GNU Free Documentation License.
75eb3bc4 188
dc546b0f 189* syntax error processing
75eb3bc4 190
dc546b0f
PE
191 - In Yacc-style parsers YYLLOC_DEFAULT is now used to compute error
192 locations too. This fixes bugs in error-location computation.
75eb3bc4 193
dc546b0f
PE
194 - %destructor
195 It is now possible to reclaim the memory associated to symbols
196 discarded during error recovery. This feature is still experimental.
20daca06 197
dc546b0f
PE
198 - %error-verbose
199 This new directive is preferred over YYERROR_VERBOSE.
74724a70 200
dc546b0f
PE
201 - #defining yyerror to steal internal variables is discouraged.
202 It is not guaranteed to work forever.
d1de5372 203
dc546b0f 204* POSIX conformance
d1de5372 205
dc546b0f
PE
206 - Semicolons are once again optional at the end of grammar rules.
207 This reverts to the behavior of Bison 1.33 and earlier, and improves
208 compatibility with Yacc.
74724a70 209
dc546b0f
PE
210 - `parse error' -> `syntax error'
211 Bison now uniformly uses the term `syntax error'; formerly, the code
212 and manual sometimes used the term `parse error' instead. POSIX
213 requires `syntax error' in diagnostics, and it was thought better to
214 be consistent.
74724a70 215
dc546b0f
PE
216 - The documentation now emphasizes that yylex and yyerror must be
217 declared before use. C99 requires this.
d1de5372 218
dc546b0f
PE
219 - Bison now parses C99 lexical constructs like UCNs and
220 backslash-newline within C escape sequences, as POSIX 1003.1-2001 requires.
d1de5372 221
dc546b0f
PE
222 - File names are properly escaped in C output. E.g., foo\bar.y is
223 output as "foo\\bar.y".
6780ca7a 224
dc546b0f
PE
225 - Yacc command and library now available
226 The Bison distribution now installs a `yacc' command, as POSIX requires.
227 Also, Bison now installs a small library liby.a containing
228 implementations of Yacc-compatible yyerror and main functions.
229 This library is normally not useful, but POSIX requires it.
6e649e65 230
dc546b0f 231 - Type clashes now generate warnings, not errors.
6e649e65 232
dc546b0f
PE
233 - If the user does not define YYSTYPE as a macro, Bison now declares it
234 using typedef instead of defining it as a macro.
235 For consistency, YYLTYPE is also declared instead of defined.
9501dc6e 236
dc546b0f 237* Other compatibility issues
886a425c 238
dc546b0f
PE
239 - %union directives can now have a tag before the `{', e.g., the
240 directive `%union foo {...}' now generates the C code
241 `typedef union foo { ... } YYSTYPE;'; this is for Yacc compatibility.
242 The default union tag is `YYSTYPE', for compatibility with Solaris 9 Yacc.
243 For consistency, YYLTYPE's struct tag is now `YYLTYPE' not `yyltype'.
244 This is for compatibility with both Yacc and Bison 1.35.
72f889cc 245
dc546b0f
PE
246 - `;' is output before the terminating `}' of an action, for
247 compatibility with Bison 1.35.
886a425c 248
dc546b0f
PE
249 - Bison now uses a Yacc-style format for conflict reports, e.g.,
250 `conflicts: 2 shift/reduce, 1 reduce/reduce'.
437c2d80 251
dc546b0f
PE
252 - `yystype' and `yyltype' are now obsolescent macros instead of being
253 typedefs or tags; they are no longer documented and are planned to be
254 withdrawn in a future release.
2a8d363a 255
dc546b0f 256* GLR parser notes
2a8d363a 257
dc546b0f
PE
258 - GLR and inline
259 Users of Bison have to decide how they handle the portability of the
260 C keyword `inline'.
959e5f51 261
dc546b0f
PE
262 - `parsing stack overflow...' -> `parser stack overflow'
263 GLR parsers now report `parser stack overflow' as per the Bison manual.
900c5db5 264
dc546b0f
PE
265* Bison now warns if it detects conflicting outputs to the same file,
266 e.g., it generates a warning for `bison -d -o foo.h foo.y' since
267 that command outputs both code and header to foo.h.
6e40b4eb 268
dc546b0f
PE
269* #line in output files
270 - --no-line works properly.
6e40b4eb
AD
271
272* Bison can no longer be built by a K&R C compiler; it requires C89 or
273 later to be built. This change originally took place a few versions
274 ago, but nobody noticed until we recently asked someone to try
275 building Bison with a K&R C compiler.
d600ee67 276\f
5c16c6b1 277Changes in version 1.75, 2002-10-14:
7933f2b5
PE
278
279* Bison should now work on 64-bit hosts.
280
b7195100 281* Indonesian translation thanks to Tedi Heriyanto.
7933f2b5 282
f50adbbd
AD
283* GLR parsers
284 Fix spurious parse errors.
285
286* Pure parsers
287 Some people redefine yyerror to steal yyparse' private variables.
288 Reenable this trick until an official feature replaces it.
289
d90c934c
AD
290* Type Clashes
291 In agreement with POSIX and with other Yaccs, leaving a default
292 action is valid when $$ is untyped, and $1 typed:
293
294 untyped: ... typed;
295
296 but the converse remains an error:
297
298 typed: ... untyped;
299
300* Values of mid-rule actions
301 The following code:
302
303 foo: { ... } { $$ = $1; } ...
304
305 was incorrectly rejected: $1 is defined in the second mid-rule
306 action, and is equal to the $$ of the first mid-rule action.
d600ee67 307\f
420f93c8 308Changes in version 1.50, 2002-10-04:
adc8c848 309
676385e2
PH
310* GLR parsing
311 The declaration
312 %glr-parser
313 causes Bison to produce a Generalized LR (GLR) parser, capable of handling
314 almost any context-free grammar, ambiguous or not. The new declarations
e8832397 315 %dprec and %merge on grammar rules allow parse-time resolution of
676385e2
PH
316 ambiguities. Contributed by Paul Hilfinger.
317
7933f2b5 318 Unfortunately Bison 1.50 does not work properly on 64-bit hosts
420f93c8
PE
319 like the Alpha, so please stick to 32-bit hosts for now.
320
8c165d89
AD
321* Output Directory
322 When not in Yacc compatibility mode, when the output file was not
e88dbdbf 323 specified, running `bison foo/bar.y' created `foo/bar.c'. It
8c165d89
AD
324 now creates `bar.c'.
325
007a50a4
AD
326* Undefined token
327 The undefined token was systematically mapped to 2 which prevented
e88dbdbf 328 the use of 2 by the user. This is no longer the case.
007a50a4 329
77714df2 330* Unknown token numbers
e88dbdbf 331 If yylex returned an out of range value, yyparse could die. This is
007a50a4
AD
332 no longer the case.
333
23c5a174 334* Error token
e88dbdbf 335 According to POSIX, the error token must be 256.
23c5a174
AD
336 Bison extends this requirement by making it a preference: *if* the
337 user specified that one of her tokens is numbered 256, then error
338 will be mapped onto another number.
339
217598da 340* Verbose error messages
e88dbdbf 341 They no longer report `..., expecting error or...' for states where
217598da
AD
342 error recovery is possible.
343
344* End token
345 Defaults to `$end' instead of `$'.
346
68cd8af3
PE
347* Error recovery now conforms to documentation and to POSIX
348 When a Bison-generated parser encounters a syntax error, it now pops
349 the stack until it finds a state that allows shifting the error
350 token. Formerly, it popped the stack until it found a state that
351 allowed some non-error action other than a default reduction on the
352 error token. The new behavior has long been the documented behavior,
353 and has long been required by POSIX. For more details, please see
337116ba
PE
354 Paul Eggert, "Reductions during Bison error handling" (2002-05-20)
355 <http://lists.gnu.org/archive/html/bug-bison/2002-05/msg00038.html>.
68cd8af3 356
5504898e
AD
357* Traces
358 Popped tokens and nonterminals are now reported.
359
a861a339
PE
360* Larger grammars
361 Larger grammars are now supported (larger token numbers, larger grammar
362 size (= sum of the LHS and RHS lengths), larger LALR tables).
363 Formerly, many of these numbers ran afoul of 16-bit limits;
364 now these limits are 32 bits on most hosts.
355e7c1c 365
77714df2 366* Explicit initial rule
643a5994
AD
367 Bison used to play hacks with the initial rule, which the user does
368 not write. It is now explicit, and visible in the reports and
369 graphs as rule 0.
23c5a174 370
77714df2 371* Useless rules
643a5994 372 Before, Bison reported the useless rules, but, although not used,
77714df2 373 included them in the parsers. They are now actually removed.
23c5a174 374
6b98e4b5
AD
375* Useless rules, useless nonterminals
376 They are now reported, as a warning, with their locations.
377
e8832397
AD
378* Rules never reduced
379 Rules that can never be reduced because of conflicts are now
380 reported.
381
77714df2 382* Incorrect `Token not used'
11652ab3
AD
383 On a grammar such as
384
385 %token useless useful
386 %%
387 exp: '0' %prec useful;
388
389 where a token was used to set the precedence of the last rule,
390 bison reported both `useful' and `useless' as useless tokens.
391
77714df2
AD
392* Revert the C++ namespace changes introduced in 1.31
393 as they caused too many portability hassles.
0179dd65 394
b2d52318
AD
395* Default locations
396 By an accident of design, the default computation of @$ was
397 performed after another default computation was performed: @$ = @1.
398 The latter is now removed: YYLLOC_DEFAULT is fully responsible of
399 the computation of @$.
adc8c848 400
b7c49edf
AD
401* Token end-of-file
402 The token end of file may be specified by the user, in which case,
403 the user symbol is used in the reports, the graphs, and the verbose
a861a339 404 error messages instead of `$end', which remains being the default.
b7c49edf 405 For instance
7bd6c77e 406 %token MYEOF 0
b7c49edf 407 or
7bd6c77e 408 %token MYEOF 0 "end of file"
fdbcd8e2
AD
409
410* Semantic parser
411 This old option, which has been broken for ages, is removed.
412
a861a339
PE
413* New translations
414 Brazilian Portuguese, thanks to Alexandre Folle de Menezes.
84614e13
AD
415 Croatian, thanks to Denis Lackovic.
416
77714df2 417* Incorrect token definitions
e88dbdbf 418 When given `%token 'a' "A"', Bison used to output `#define 'a' 65'.
b87f8b21 419
77714df2
AD
420* Token definitions as enums
421 Tokens are output both as the traditional #define's, and, provided
422 the compiler supports ANSI C or is a C++ compiler, as enums.
e88dbdbf 423 This lets debuggers display names instead of integers.
77714df2 424
ec3bc396
AD
425* Reports
426 In addition to --verbose, bison supports --report=THINGS, which
427 produces additional information:
b408954b
AD
428 - itemset
429 complete the core item sets with their closure
8dd162d3
PE
430 - lookahead [changed to `look-ahead' in 1.875e and later]
431 explicitly associate look-ahead tokens to items
b408954b
AD
432 - solved
433 describe shift/reduce conflicts solving.
434 Bison used to systematically output this information on top of
435 the report. Solved conflicts are now attached to their states.
ec3bc396 436
9af3fbce
AD
437* Type clashes
438 Previous versions don't complain when there is a type clash on
439 the default action if the rule has a mid-rule action, such as in:
440
441 %type <foo> bar
442 %%
443 bar: '0' {} '0';
444
445 This is fixed.
a861a339
PE
446
447* GNU M4 is now required when using Bison.
f987e9d2 448\f
76551463
AD
449Changes in version 1.35, 2002-03-25:
450
451* C Skeleton
452 Some projects use Bison's C parser with C++ compilers, and define
453 YYSTYPE as a class. The recent adjustment of C parsers for data
454 alignment and 64 bit architectures made this impossible.
455
456 Because for the time being no real solution for C++ parser
457 generation exists, kludges were implemented in the parser to
458 maintain this use. In the future, when Bison has C++ parsers, this
459 kludge will be disabled.
460
461 This kludge also addresses some C++ problems when the stack was
462 extended.
76551463
AD
463\f
464Changes in version 1.34, 2002-03-12:
465
466* File name clashes are detected
467 $ bison foo.y -d -o foo.x
468 fatal error: header and parser would both be named `foo.x'
469
470* A missing `;' at the end of a rule triggers a warning
471 In accordance with POSIX, and in agreement with other
472 Yacc implementations, Bison will mandate this semicolon in the near
473 future. This eases the implementation of a Bison parser of Bison
474 grammars by making this grammar LALR(1) instead of LR(2). To
475 facilitate the transition, this release introduces a warning.
476
477* Revert the C++ namespace changes introduced in 1.31, as they caused too
478 many portability hassles.
479
480* DJGPP support added.
481
482* Fix test suite portability problems.
483\f
484Changes in version 1.33, 2002-02-07:
485
486* Fix C++ issues
487 Groff could not be compiled for the definition of size_t was lacking
488 under some conditions.
489
490* Catch invalid @n
491 As is done with $n.
492\f
493Changes in version 1.32, 2002-01-23:
494
495* Fix Yacc output file names
496
497* Portability fixes
498
499* Italian, Dutch translations
500\f
52d1aeee
MA
501Changes in version 1.31, 2002-01-14:
502
503* Many Bug Fixes
504
505* GNU Gettext and %expect
506 GNU Gettext asserts 10 s/r conflicts, but there are 7. Now that
507 Bison dies on incorrect %expectations, we fear there will be
508 too many bug reports for Gettext, so _for the time being_, %expect
509 does not trigger an error when the input file is named `plural.y'.
510
511* Use of alloca in parsers
512 If YYSTACK_USE_ALLOCA is defined to 0, then the parsers will use
513 malloc exclusively. Since 1.29, but was not NEWS'ed.
514
515 alloca is used only when compiled with GCC, to avoid portability
516 problems as on AIX.
517
b47dbebe
PE
518* yyparse now returns 2 if memory is exhausted; formerly it dumped core.
519
52d1aeee
MA
520* When the generated parser lacks debugging code, YYDEBUG is now 0
521 (as POSIX requires) instead of being undefined.
522
523* User Actions
524 Bison has always permitted actions such as { $$ = $1 }: it adds the
525 ending semicolon. Now if in Yacc compatibility mode, the semicolon
526 is no longer output: one has to write { $$ = $1; }.
527
528* Better C++ compliance
529 The output parsers try to respect C++ namespaces.
76551463 530 [This turned out to be a failed experiment, and it was reverted later.]
52d1aeee
MA
531
532* Reduced Grammars
533 Fixed bugs when reporting useless nonterminals.
534
535* 64 bit hosts
536 The parsers work properly on 64 bit hosts.
537
538* Error messages
539 Some calls to strerror resulted in scrambled or missing error messages.
540
541* %expect
542 When the number of shift/reduce conflicts is correct, don't issue
543 any warning.
544
545* The verbose report includes the rule line numbers.
546
547* Rule line numbers are fixed in traces.
548
549* Swedish translation
550
551* Parse errors
552 Verbose parse error messages from the parsers are better looking.
553 Before: parse error: unexpected `'/'', expecting `"number"' or `'-'' or `'(''
554 Now: parse error: unexpected '/', expecting "number" or '-' or '('
555
556* Fixed parser memory leaks.
557 When the generated parser was using malloc to extend its stacks, the
558 previous allocations were not freed.
559
560* Fixed verbose output file.
561 Some newlines were missing.
562 Some conflicts in state descriptions were missing.
563
564* Fixed conflict report.
565 Option -v was needed to get the result.
566
567* %expect
568 Was not used.
569 Mismatches are errors, not warnings.
570
571* Fixed incorrect processing of some invalid input.
572
573* Fixed CPP guards: 9foo.h uses BISON_9FOO_H instead of 9FOO_H.
574
575* Fixed some typos in the documentation.
576
577* %token MY_EOF 0 is supported.
578 Before, MY_EOF was silently renumbered as 257.
579
580* doc/refcard.tex is updated.
581
582* %output, %file-prefix, %name-prefix.
583 New.
584
585* --output
586 New, aliasing `--output-file'.
587\f
76551463 588Changes in version 1.30, 2001-10-26:
342b8b6e 589
fdac0091
PE
590* `--defines' and `--graph' have now an optional argument which is the
591 output file name. `-d' and `-g' do not change; they do not take any
342b8b6e
AD
592 argument.
593
594* `%source_extension' and `%header_extension' are removed, failed
595 experiment.
596
f987e9d2
AD
597* Portability fixes.
598\f
9f4503d6 599Changes in version 1.29, 2001-09-07:
342b8b6e
AD
600
601* The output file does not define const, as this caused problems when used
602 with common autoconfiguration schemes. If you still use ancient compilers
603 that lack const, compile with the equivalent of the C compiler option
604 `-Dconst='. autoconf's AC_C_CONST macro provides one way to do this.
605
606* Added `-g' and `--graph'.
f87a2205 607
f2b5126e
PB
608* The Bison manual is now distributed under the terms of the GNU FDL.
609
f1c63ced 610* The input and the output files has automatically a similar extension.
234a3be3 611
f87a2205
JT
612* Russian translation added.
613
614* NLS support updated; should hopefully be less troublesome.
615
616* Added the old Bison reference card.
c33638bb
AD
617
618* Added `--locations' and `%locations'.
6deb4447 619
cd5bd6ac
AD
620* Added `-S' and `--skeleton'.
621
62ab6972
AD
622* `%raw', `-r', `--raw' is disabled.
623
cd5bd6ac
AD
624* Special characters are escaped when output. This solves the problems
625 of the #line lines with path names including backslashes.
626
6deb4447 627* New directives.
4ecbf796
MA
628 `%yacc', `%fixed_output_files', `%defines', `%no_parser', `%verbose',
629 `%debug', `%source_extension' and `%header_extension'.
f987e9d2
AD
630
631* @$
632 Automatic location tracking.
f87a2205 633\f
9f4503d6 634Changes in version 1.28, 1999-07-06:
d2e00347
JT
635
636* Should compile better now with K&R compilers.
637
638* Added NLS.
639
640* Fixed a problem with escaping the double quote character.
641
642* There is now a FAQ.
643\f
5c31c3c2
JT
644Changes in version 1.27:
645
646* The make rule which prevented bison.simple from being created on
647 some systems has been fixed.
648\f
649Changes in version 1.26:
4be07551
JT
650
651* Bison now uses automake.
652
653* New mailing lists: <bug-bison@gnu.org> and <help-bison@gnu.org>.
654
655* Token numbers now start at 257 as previously documented, not 258.
656
657* Bison honors the TMPDIR environment variable.
658
659* A couple of buffer overruns have been fixed.
f51dbca1
JT
660
661* Problems when closing files should now be reported.
662
663* Generated parsers should now work even on operating systems which do
664 not provide alloca().
4be07551 665\f
9f4503d6 666Changes in version 1.25, 1995-10-16:
df8878c5
RS
667
668* Errors in the input grammar are not fatal; Bison keeps reading
669the grammar file, and reports all the errors found in it.
8c44d3ec 670
df8878c5
RS
671* Tokens can now be specified as multiple-character strings: for
672example, you could use "<=" for a token which looks like <=, instead
673of chosing a name like LESSEQ.
674
675* The %token_table declaration says to write a table of tokens (names
676and numbers) into the parser file. The yylex function can use this
677table to recognize multiple-character string tokens, or for other
678purposes.
679
680* The %no_lines declaration says not to generate any #line preprocessor
681directives in the parser file.
682
683* The %raw declaration says to use internal Bison token numbers, not
684Yacc-compatible token numbers, when token names are defined as macros.
685
686* The --no-parser option produces the parser tables without including
687the parser engine; a project can now use its own parser engine.
688The actions go into a separate file called NAME.act, in the form of
689a switch statement body.
690\f
6780ca7a
DM
691Changes in version 1.23:
692
4d019228
DM
693The user can define YYPARSE_PARAM as the name of an argument to be
694passed into yyparse. The argument should have type void *. It should
695actually point to an object. Grammar actions can access the variable
696by casting it to the proper pointer type.
6780ca7a 697
6780ca7a 698Line numbers in output file corrected.
6780ca7a
DM
699\f
700Changes in version 1.22:
701
702--help option added.
6780ca7a
DM
703\f
704Changes in version 1.20:
705
706Output file does not redefine const for C++.
9f4503d6
AD
707
708Local Variables:
709mode: outline
710End:
76551463
AD
711
712-----
713
d6ca7905
PE
714Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
7152004, 2005, 2006 Free Software Foundation, Inc.
76551463 716
75eb3bc4 717This file is part of Bison, the GNU Compiler Compiler.
76551463 718
75eb3bc4 719Bison is free software; you can redistribute it and/or modify
76551463
AD
720it under the terms of the GNU General Public License as published by
721the Free Software Foundation; either version 2, or (at your option)
722any later version.
723
75eb3bc4 724Bison is distributed in the hope that it will be useful,
76551463
AD
725but WITHOUT ANY WARRANTY; without even the implied warranty of
726MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
727GNU General Public License for more details.
728
729You should have received a copy of the GNU General Public License
730along with autoconf; see the file COPYING. If not, write to
0fb669f9
PE
731the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
732Boston, MA 02110-1301, USA.