X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/4d019228a484920fe08b23a7a9f006660a039a1e..670ddffd5ba88d6d5baf6aa51803592687ae48b0:/NEWS diff --git a/NEWS b/NEWS index c094c707..e4acf388 100644 --- a/NEWS +++ b/NEWS @@ -1,6 +1,343 @@ Bison News ---------- +Changes in version 1.49b: + +* Undefined token + The undefined token was systematically mapped to 2 which prevented + the use of 2 from the user. This is no longer the case. + +* Unknown token numbers + If yylex returned a code out of range, yyparse could die. This is + no longer the case. + +* Error token + According to POSIX, the error token should be numbered as 256. + Bison extends this requirement by making it a preference: *if* the + user specified that one of her tokens is numbered 256, then error + will be mapped onto another number. + +* Error recovery now conforms to documentation and to POSIX + When a Bison-generated parser encounters a syntax error, it now pops + the stack until it finds a state that allows shifting the error + token. Formerly, it popped the stack until it found a state that + allowed some non-error action other than a default reduction on the + error token. The new behavior has long been the documented behavior, + and has long been required by POSIX. For more details, please see + . + +* Traces + Popped tokens and nonterminals are now reported. + +* Large grammars + Large grammars are now supported (large token numbers, large grammar + size (= sum of the LHS and RHS lengths), large LALR tables). + +* Explicit initial rule + Bison used to play hacks with the initial rule, which the user does + not write. It is now explicit, and visible in the reports and + graphs as rule 0. + +* Useless rules + Before, Bison reported the useless rules, but, although not used, + included them in the parsers. They are now actually removed. + +* Incorrect `Token not used' + On a grammar such as + + %token useless useful + %% + exp: '0' %prec useful; + + where a token was used to set the precedence of the last rule, + bison reported both `useful' and `useless' as useless tokens. + +* Revert the C++ namespace changes introduced in 1.31 + as they caused too many portability hassles. + +* Default locations + By an accident of design, the default computation of @$ was + performed after another default computation was performed: @$ = @1. + The latter is now removed: YYLLOC_DEFAULT is fully responsible of + the computation of @$. + +* Token end-of-file + The token end of file may be specified by the user, in which case, + the user symbol is used in the reports, the graphs, and the verbose + error messages instead of `$', which remains being the defaults. + For instance + %token YYEOF 0 + or + %token YYEOF 0 "end of file" + +* Semantic parser + This old option, which has been broken for ages, is removed. + +* New translation + Croatian, thanks to Denis Lackovic. + +* Incorrect token definitions + When fed with `%token 'a' "A"', Bison used to output `#define 'a' 65'. + +* Token definitions as enums + Tokens are output both as the traditional #define's, and, provided + the compiler supports ANSI C or is a C++ compiler, as enums. + This helps debuggers producing symbols instead of values. + +* Reports + In addition to --verbose, bison supports --report=THINGS, which + produces additional information: + - itemset + complete the core item sets with their closure + - lookahead + explicitly associate lookaheads to items + - solved + describe shift/reduce conflicts solving. + Bison used to systematically output this information on top of + the report. Solved conflicts are now attached to their states. + + +Changes in version 1.35, 2002-03-25: + +* C Skeleton + Some projects use Bison's C parser with C++ compilers, and define + YYSTYPE as a class. The recent adjustment of C parsers for data + alignment and 64 bit architectures made this impossible. + + Because for the time being no real solution for C++ parser + generation exists, kludges were implemented in the parser to + maintain this use. In the future, when Bison has C++ parsers, this + kludge will be disabled. + + This kludge also addresses some C++ problems when the stack was + extended. + + +Changes in version 1.34, 2002-03-12: + +* File name clashes are detected + $ bison foo.y -d -o foo.x + fatal error: header and parser would both be named `foo.x' + +* A missing `;' at the end of a rule triggers a warning + In accordance with POSIX, and in agreement with other + Yacc implementations, Bison will mandate this semicolon in the near + future. This eases the implementation of a Bison parser of Bison + grammars by making this grammar LALR(1) instead of LR(2). To + facilitate the transition, this release introduces a warning. + +* Revert the C++ namespace changes introduced in 1.31, as they caused too + many portability hassles. + +* DJGPP support added. + +* Fix test suite portability problems. + +Changes in version 1.33, 2002-02-07: + +* Fix C++ issues + Groff could not be compiled for the definition of size_t was lacking + under some conditions. + +* Catch invalid @n + As is done with $n. + +Changes in version 1.32, 2002-01-23: + +* Fix Yacc output file names + +* Portability fixes + +* Italian, Dutch translations + +Changes in version 1.31, 2002-01-14: + +* Many Bug Fixes + +* GNU Gettext and %expect + GNU Gettext asserts 10 s/r conflicts, but there are 7. Now that + Bison dies on incorrect %expectations, we fear there will be + too many bug reports for Gettext, so _for the time being_, %expect + does not trigger an error when the input file is named `plural.y'. + +* Use of alloca in parsers + If YYSTACK_USE_ALLOCA is defined to 0, then the parsers will use + malloc exclusively. Since 1.29, but was not NEWS'ed. + + alloca is used only when compiled with GCC, to avoid portability + problems as on AIX. + +* When the generated parser lacks debugging code, YYDEBUG is now 0 + (as POSIX requires) instead of being undefined. + +* User Actions + Bison has always permitted actions such as { $$ = $1 }: it adds the + ending semicolon. Now if in Yacc compatibility mode, the semicolon + is no longer output: one has to write { $$ = $1; }. + +* Better C++ compliance + The output parsers try to respect C++ namespaces. + [This turned out to be a failed experiment, and it was reverted later.] + +* Reduced Grammars + Fixed bugs when reporting useless nonterminals. + +* 64 bit hosts + The parsers work properly on 64 bit hosts. + +* Error messages + Some calls to strerror resulted in scrambled or missing error messages. + +* %expect + When the number of shift/reduce conflicts is correct, don't issue + any warning. + +* The verbose report includes the rule line numbers. + +* Rule line numbers are fixed in traces. + +* Swedish translation + +* Parse errors + Verbose parse error messages from the parsers are better looking. + Before: parse error: unexpected `'/'', expecting `"number"' or `'-'' or `'('' + Now: parse error: unexpected '/', expecting "number" or '-' or '(' + +* Fixed parser memory leaks. + When the generated parser was using malloc to extend its stacks, the + previous allocations were not freed. + +* Fixed verbose output file. + Some newlines were missing. + Some conflicts in state descriptions were missing. + +* Fixed conflict report. + Option -v was needed to get the result. + +* %expect + Was not used. + Mismatches are errors, not warnings. + +* Fixed incorrect processing of some invalid input. + +* Fixed CPP guards: 9foo.h uses BISON_9FOO_H instead of 9FOO_H. + +* Fixed some typos in the documentation. + +* %token MY_EOF 0 is supported. + Before, MY_EOF was silently renumbered as 257. + +* doc/refcard.tex is updated. + +* %output, %file-prefix, %name-prefix. + New. + +* --output + New, aliasing `--output-file'. + +Changes in version 1.30, 2001-10-26: + +* `--defines' and `--graph' have now an optionnal argument which is the + output file name. `-d' and `-g' do not change, they do not take any + argument. + +* `%source_extension' and `%header_extension' are removed, failed + experiment. + +* Portability fixes. + +Changes in version 1.29, 2001-09-07: + +* The output file does not define const, as this caused problems when used + with common autoconfiguration schemes. If you still use ancient compilers + that lack const, compile with the equivalent of the C compiler option + `-Dconst='. autoconf's AC_C_CONST macro provides one way to do this. + +* Added `-g' and `--graph'. + +* The Bison manual is now distributed under the terms of the GNU FDL. + +* The input and the output files has automatically a similar extension. + +* Russian translation added. + +* NLS support updated; should hopefully be less troublesome. + +* Added the old Bison reference card. + +* Added `--locations' and `%locations'. + +* Added `-S' and `--skeleton'. + +* `%raw', `-r', `--raw' is disabled. + +* Special characters are escaped when output. This solves the problems + of the #line lines with path names including backslashes. + +* New directives. + `%yacc', `%fixed_output_files', `%defines', `%no_parser', `%verbose', + `%debug', `%source_extension' and `%header_extension'. + +* @$ + Automatic location tracking. + +Changes in version 1.28, 1999-07-06: + +* Should compile better now with K&R compilers. + +* Added NLS. + +* Fixed a problem with escaping the double quote character. + +* There is now a FAQ. + +Changes in version 1.27: + +* The make rule which prevented bison.simple from being created on + some systems has been fixed. + +Changes in version 1.26: + +* Bison now uses automake. + +* New mailing lists: and . + +* Token numbers now start at 257 as previously documented, not 258. + +* Bison honors the TMPDIR environment variable. + +* A couple of buffer overruns have been fixed. + +* Problems when closing files should now be reported. + +* Generated parsers should now work even on operating systems which do + not provide alloca(). + +Changes in version 1.25, 1995-10-16: + +* Errors in the input grammar are not fatal; Bison keeps reading +the grammar file, and reports all the errors found in it. + +* Tokens can now be specified as multiple-character strings: for +example, you could use "<=" for a token which looks like <=, instead +of chosing a name like LESSEQ. + +* The %token_table declaration says to write a table of tokens (names +and numbers) into the parser file. The yylex function can use this +table to recognize multiple-character string tokens, or for other +purposes. + +* The %no_lines declaration says not to generate any #line preprocessor +directives in the parser file. + +* The %raw declaration says to use internal Bison token numbers, not +Yacc-compatible token numbers, when token names are defined as macros. + +* The --no-parser option produces the parser tables without including +the parser engine; a project can now use its own parser engine. +The actions go into a separate file called NAME.act, in the form of +a switch statement body. + Changes in version 1.23: The user can define YYPARSE_PARAM as the name of an argument to be @@ -8,24 +345,37 @@ passed into yyparse. The argument should have type void *. It should actually point to an object. Grammar actions can access the variable by casting it to the proper pointer type. -Error in printing reductions fixed. - Line numbers in output file corrected. - -Configuration and compilation problems fixed. Changes in version 1.22: --help option added. - -Configuration and compilation problems fixed. - -Changes in version 1.21: - -Configuration and compilation problems fixed. Changes in version 1.20: Output file does not redefine const for C++. -Configuration and compilation problems fixed. +Local Variables: +mode: outline +End: + +----- + +Copyright (C) 2001, 2002 Free Software Foundation, Inc. + +This file is part of GNU Autoconf. + +GNU Autoconf is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Autoconf is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with autoconf; see the file COPYING. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA.