X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/6d58c632025cb6928a90e4176577982bfb9c3981..0fe9720964da510a2b359af390a3053aace65f9f:/NEWS diff --git a/NEWS b/NEWS index cb594715..39c812e0 100644 --- a/NEWS +++ b/NEWS @@ -240,28 +240,70 @@ 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] + +** Bug fixes + + Warnings about uninitialized yylloc in yyparse have been fixed. -** Changes in the format of error messages + Restored C90 compliance (yet no report was ever made). + +** 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) @@ -282,7 +324,16 @@ GNU Bison NEWS position_type are deprecated in favor of api.location.type and api.position.type. -** Graphviz improvements +** 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 now rectangular, the state number is clearly displayed, and the items are @@ -291,6 +342,24 @@ GNU Bison NEWS 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. + +** %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. @@ -676,6 +745,7 @@ 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): @@ -1192,6 +1262,7 @@ 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 @@ -1205,6 +1276,7 @@ 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: