X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/a1a77e1fcc32e94aff477f2a98c15172b199d1e0..c49e2f153521a86f22b2631ca8a1fb6389c3a70e:/NEWS diff --git a/NEWS b/NEWS index c8a4d312..593251a6 100644 --- a/NEWS +++ b/NEWS @@ -4,17 +4,36 @@ GNU Bison NEWS ** Bug fixes - Bugs and portability issues in the test suite have been fixed. + Warnings about uninitialized yylloc in yyparse have been fixed. - Some errors in translations have been addressed, and --help now directs - users to the appropriate place to report them. +** %language is no longer an experimental feature. - Stray Info files shipped by accident are removed. + The introduction of this feature, in 2.4, was four years ago. The --language + option and the %language directive are no longer experimental. - Incorrect definitions of YY_, issued by yacc.c when no parser header is - generated, are removed. +** New format for error reports: carets - All the generated headers are self-contained. + Caret errors have been added to Bison, for example (taken from the + documentation): + + input.y:3.20-23: error: ambiguous reference: '$exp' + exp: exp '+' exp { $exp = $1 + $2; }; + ^^^^ + + The default behaviour for now is still not to display these unless explictly + asked with -fall of -fcaret. However, in a later release, it will be made the + default behavior (but may still be deactivated with -fno-caret). + +** New value for %define variable: api.pure full + + The %define variable api.pure requests a pure (reentrant) parser. However, + for historical reasons, using it in a location-tracking Yacc parser resulted + in an yyerror function that did not take a location as a parameter. With this + new value, the user may request a better pure parser, where yyerror does take + a location as a parameter (in location-tracking parsers). + + The use of "%define api.pure true" is deprecated in favor of this new + "%define api.pure full". ** Changes in the format of error messages @@ -28,6 +47,92 @@ GNU Bison NEWS foo.y:5.10-25: result type clash on merge function 'merge': != foo.y:4.13-27: previous declaration +** Exception safety (lalr1.cc) + + The parse function now catches exceptions, uses the %destructors to + release memory (the lookahead symbol and the symbols pushed on the stack) + before re-throwing the exception. + + This feature is somewhat experimental. User feedback would be + appreciated. + +** New %define variable: api.location.type (glr.cc, lalr1.cc, lalr1.java) + + The %define variable api.location.type defines the name of the type to use + for locations. When defined, Bison no longer generates the position.hh + and location.hh files, nor does the parser will include them: the user is + then responsible to define her type. + + This can be used in programs with several parsers to factor their location + and position files: let one of them generate them, and the others just use + them. + + This feature was actually introduced, but not documented, in Bison 2.5, + under the name "location_type" (which is maintained for backward + compatibility). + + For consistency, lalr1.java's %define variables location_type and + position_type are deprecated in favor of api.location.type and + api.position.type. + +** Graph improvements in DOT and XSLT + + The graphical presentation of the states is more readable: their shape is + now rectangular, the state number is clearly displayed, and the items are + numbered and left-justified. + + The reductions are now explicitly represented as transitions to other + diamond shaped nodes. + + These changes are present in both --graph output and xml2dot.xsl XSLT + processing, with minor (documented) differences. + + Two nodes were added to the documentation: Xml and Graphviz. + +** Documentation + + The sections about shift/reduce and reduce/reduce conflicts resolution + have been fixed and extended. + +* Noteworthy changes in release 2.6.5 (2012-11-07) [stable] + + We consider compiler warnings about Bison generated parsers to be bugs. + Rather than working around them in your own project, please consider + reporting them to us. + +** Bug fixes + + Warnings about uninitialized yylval and/or yylloc for push parsers with a + pure interface have been fixed for GCC 4.0 up to 4.8, and Clang 2.9 to + 3.2. + + Other issues in the test suite have been addressed. + + Nul characters are correctly displayed in error messages. + + When possible, yylloc is correctly initialized before calling yylex. It + is no longer necessary to initialize it in the %initial-action. + +* Noteworthy changes in release 2.6.4 (2012-10-23) [stable] + + Bison 2.6.3's --version was incorrect. This release fixes this issue. + +* Noteworthy changes in release 2.6.3 (2012-10-22) [stable] + +** Bug fixes + + Bugs and portability issues in the test suite have been fixed. + + Some errors in translations have been addressed, and --help now directs + users to the appropriate place to report them. + + Stray Info files shipped by accident are removed. + + Incorrect definitions of YY_, issued by yacc.c when no parser header is + generated, are removed. + + All the generated headers are self-contained. + ** Header guards (yacc.c, glr.c, glr.cc) In order to avoid collisions, the header guards are now @@ -39,6 +144,23 @@ GNU Bison NEWS will use YY_CALC_LIB_PARSE_H_INCLUDED as guard. +** Fix compiler warnings in the generated parser (yacc.c, glr.c) + + The compilation of pure parsers (%define api.pure) can trigger GCC + warnings such as: + + input.c: In function 'yyparse': + input.c:1503:12: warning: 'yylval' may be used uninitialized in this + function [-Wmaybe-uninitialized] + *++yyvsp = yylval; + ^ + + This is now fixed; pragmas to avoid these warnings are no longer needed. + + Warnings from clang ("equality comparison with extraneous parentheses" and + "function declared 'noreturn' should not return") have also been + addressed. + * Noteworthy changes in release 2.6.2 (2012-08-03) [stable] ** Bug fixes @@ -1896,7 +2018,8 @@ along with this program. If not, see . LocalWords: namespaces strerror const autoconfiguration Dconst Autoconf's FDL LocalWords: Automake TMPDIR LESSEQ ylwrap endif yydebug YYTOKEN YYLSP ival hh LocalWords: extern YYTOKENTYPE TOKENTYPE yytokentype tokentype STYPE lval pdf - LocalWords: lang yyoutput dvi html ps POSIX lvalp llocp calc yyo fval + LocalWords: lang yyoutput dvi html ps POSIX lvalp llocp calc yyo fval Wmaybe + LocalWords: yyvsp pragmas noreturn java's Local Variables: mode: outline