X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/edf9a06f27c9228b8c62cfe40be1f608ecf549a9..0a7b855930312a1e2d86227609d743352d860bd3:/NEWS?ds=sidebyside diff --git a/NEWS b/NEWS index 593251a6..12242e18 100644 --- a/NEWS +++ b/NEWS @@ -2,59 +2,71 @@ GNU Bison NEWS * Noteworthy changes in release ?.? (????-??-??) [?] + +* Noteworthy changes in release 2.7 (2012-12-12) [stable] + ** Bug fixes Warnings about uninitialized yylloc in yyparse have been fixed. -** %language is no longer an experimental feature. + Restored C90 compliance (yet no report was ever made). - The introduction of this feature, in 2.4, was four years ago. The --language - option and the %language directive are no longer experimental. +** Diagnostics are improved -** New format for error reports: carets +*** Changes in the format of error messages - Caret errors have been added to Bison, for example (taken from the - documentation): + This used to be the format of many error reports: - input.y:3.20-23: error: ambiguous reference: '$exp' - exp: exp '+' exp { $exp = $1 + $2; }; - ^^^^ + input.y:2.7-12: %type redeclaration for exp + input.y:1.7-12: previous declaration - The default behaviour for now is still not to display these unless explictly - asked with -fall of -fcaret. However, in a later release, it will be made the - default behavior (but may still be deactivated with -fno-caret). + It is now: -** New value for %define variable: api.pure full + input.y:2.7-12: error: %type redeclaration for exp + input.y:1.7-12: previous declaration - The %define variable api.pure requests a pure (reentrant) parser. However, - for historical reasons, using it in a location-tracking Yacc parser resulted - in an yyerror function that did not take a location as a parameter. With this - new value, the user may request a better pure parser, where yyerror does take - a location as a parameter (in location-tracking parsers). +*** New format for error reports: carets - The use of "%define api.pure true" is deprecated in favor of this new - "%define api.pure full". + Caret errors have been added to Bison: -** Changes in the format of error messages + input.y:2.7-12: error: %type redeclaration for exp + %type exp + ^^^^^^ + input.y:1.7-12: previous declaration + %type exp + ^^^^^^ - This used to be the format of many error reports: - - foo.y:5.10-24: result type clash on merge function 'merge': != - foo.y:4.13-27: previous declaration - - It is now: + or - foo.y:5.10-25: result type clash on merge function 'merge': != - foo.y:4.13-27: previous declaration + input.y:3.20-23: error: ambiguous reference: '$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). -** Exception safety (lalr1.cc) +** New value for %define variable: api.pure full - 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. + 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). - This feature is somewhat experimental. User feedback would be - appreciated. + 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) @@ -75,6 +87,15 @@ 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 @@ -87,13 +108,21 @@ 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. +** %language is no longer an experimental feature. + + 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.