X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/5807bb9156930091850a52b5bb9ab9f89082b04e..465df9c65c7022a66e9cea7145b80886174e90af:/NEWS?ds=sidebyside diff --git a/NEWS b/NEWS index a1bb0f91..d4f8a750 100644 --- a/NEWS +++ b/NEWS @@ -6,10 +6,13 @@ GNU Bison NEWS *** Obsolete features - Support for YYFAIL is removed (deprecated in Bison 2.4.2). - Support for yystype and yyltype (instead of YYSTYPE and YYLTYPE) - is removed (deprecated in Bison 1.875). - Support for YYPARSE_PARAM is removed (deprecated in Bison 1.875). + Support for YYFAIL is removed (deprecated in Bison 2.4.2): use YYERROR. + + Support for yystype and yyltype is removed (deprecated in Bison 1.875): + use YYSTYPE and YYLTYPE. + + Support for YYLEX_PARAM and YYPARSE_PARAM is removed (deprecated in Bison + 1.875): use %lex-param, %parse-param, or %param. ** Warnings @@ -240,39 +243,70 @@ GNU Bison NEWS It used to be an error only if used in non GLR mode, _and_ if there are reduce/reduce conflicts. -* Noteworthy changes in release ?.? (????-??-??) [?] +* Noteworthy changes in release 2.7 (2012-12-12) [stable] -** New value for %define variable: api.pure full +** Bug fixes - 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). + Warnings about uninitialized yylloc in yyparse have been fixed. - The use of "%define api.pure true" is deprecated in favor of this new - "%define api.pure full". + Restored C90 compliance (yet no report was ever made). -** Changes in the format of error messages +** Diagnostics are improved + +*** Changes in the format of error messages This used to be the format of many error reports: - foo.y:5.10-24: result type clash on merge function 'merge': != - foo.y:4.13-27: previous declaration + input.y:2.7-12: %type redeclaration for exp + input.y:1.7-12: previous declaration It is now: - foo.y:5.10-25: result type clash on merge function 'merge': != - foo.y:4.13-27: previous declaration + input.y:2.7-12: error: %type redeclaration for exp + input.y:1.7-12: previous declaration -** Exception safety (lalr1.cc) +*** New format for error reports: carets - 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. + Caret errors have been added to Bison: - This feature is somewhat experimental. User feedback would be - appreciated. + input.y:2.7-12: error: %type redeclaration for exp + %type exp + ^^^^^^ + input.y:1.7-12: previous declaration + %type exp + ^^^^^^ + + or + + input.y:3.20-23: error: ambiguous reference: '$exp' + exp: exp '+' exp { $exp = $1 + $3; }; + ^^^^ + input.y:3.1-3: refers to: $exp at $$ + exp: exp '+' exp { $exp = $1 + $3; }; + ^^^ + input.y:3.6-8: refers to: $exp at $1 + exp: exp '+' exp { $exp = $1 + $3; }; + ^^^ + input.y:3.14-16: refers to: $exp at $3 + exp: exp '+' exp { $exp = $1 + $3; }; + ^^^ + + The default behaviour for now is still not to display these unless + explictly asked with -fcaret (or -fall). 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 a 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". ** New %define variable: api.location.type (glr.cc, lalr1.cc, lalr1.java) @@ -293,6 +327,15 @@ GNU Bison NEWS position_type are deprecated in favor of api.location.type and api.position.type. +** 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. + ** Graph improvements in DOT and XSLT The graphical presentation of the states is more readable: their shape is @@ -305,19 +348,21 @@ GNU Bison NEWS 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. - -* Noteworthy changes in release ?.? (????-??-??) [?] - -** Bug fixes +** %language is no longer an experimental feature. - Warnings about uninitialized yylloc in yyparse have been fixed. + The introduction of this feature, in 2.4, was four years ago. The + --language option and the %language directive are no longer experimental. ** Documentation The sections about shift/reduce and reduce/reduce conflicts resolution have been fixed and extended. + Although introduced more than four years ago, XML and Graphviz reports + were not properly documented. + + The translation of mid-rule actions is now described. + * Noteworthy changes in release 2.6.5 (2012-11-07) [stable] We consider compiler warnings about Bison generated parsers to be bugs. @@ -703,6 +748,7 @@ GNU Bison NEWS These features are experimental in this version. More user feedback will help to stabilize them. + Contributed by Alex Rozenman. ** IELR(1) and canonical LR(1): @@ -1219,6 +1265,7 @@ GNU Bison NEWS The current Java interface is experimental and may evolve. More user feedback will help to stabilize it. + Contributed by Paolo Bonzini. ** %language @@ -1232,6 +1279,7 @@ GNU Bison NEWS Bison can now generate an XML report of the LALR(1) automaton using the new "--xml" option. The current XML schema is experimental and may evolve. More user feedback will help to stabilize it. + Contributed by Wojciech Polak. ** The grammar file may now specify the name of the parser header file using %defines. For example: