X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/3eb4f1a3e62807125a815dc572da9204b5b51865..1f77b2e095492ae95ae6ab33b3ad1f1bf5d758d8:/NEWS diff --git a/NEWS b/NEWS index 8db03d60..f6e6a8c6 100644 --- a/NEWS +++ b/NEWS @@ -2,9 +2,24 @@ GNU Bison NEWS * Noteworthy changes in release ?.? (????-??-??) [?] +** Incompatible changes + +*** 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). + ** Warnings -*** Warning categories are now displayed in warnings +*** Deprecated constructs + + The new 'deprecated' warning category flags obsolete constructs whose + support will be discontinued. It is enabled by default. These warnings + used to be reported as 'other' warnings. + +*** Warning categories are now displayed For instance: @@ -27,18 +42,17 @@ GNU Bison NEWS 3.28-34: warning: type is used, but is not associated to any symbol 4.28-34: warning: type is used, but is not associated to any symbol -*** Undeclared symbols +*** Undefined but unused symbols - Bison used to raise an error for %printer and %destructor directives for - undefined symbols. + Bison used to raise an error for undefined symbols that are not used in + the grammar. This is now only a warning. %printer {} symbol1 %destructor {} symbol2 + %type symbol3 %% exp: "a"; - This is now only a warning. - *** Useless destructors or printers Bison now warns about useless destructors or printers. In the following @@ -70,11 +84,23 @@ GNU Bison NEWS ** Java skeleton improvements - The constants for token names were moved to the Lexer interface. - Also, it is possible to add code to the parser's constructors using - "%code init" and "%define init_throws". + The constants for token names were moved to the Lexer interface. Also, it + is possible to add code to the parser's constructors using "%code init" + and "%define init_throws". + +** C++ skeletons improvements + +*** The parser header is no longer mandatory (lalr1.cc, glr.cc) + + Using %defines is now optional. Without it, the needed support classes + are defined in the generated parser, instead of additional files (such as + location.hh, position.hh and stack.hh). + +*** Locations are no longer mandatory (lalr1.cc, glr.cc) -** C++ skeleton improvements + Both lalr1.cc and glr.cc no longer require %location. + +*** syntax_error exception (lalr1.cc) The C++ parser features a syntax_error exception, which can be thrown from the scanner or from user rules to raise syntax errors. @@ -101,27 +127,81 @@ GNU Bison NEWS ** Variable api.namespace - The "namespace" variable is renamed "api.namespace". Backward + The 'namespace' variable is renamed 'api.namespace'. Backward compatibility is ensured, but upgrading is recommended. ** Variable parse.error - The variable error controls the verbosity of error messages. The - use of the %error-verbose directive is deprecated in favor of - %define parse.error "verbose". + This variable controls the verbosity of error messages. The use of the + %error-verbose directive is deprecated in favor of "%define parse.error + verbose". ** Semantic predicates - The new, experimental, semantic-predicate feature allows actions of - the form %?{ BOOLEAN-EXPRESSION }, which cause syntax errors (as for + The new, experimental, semantic-predicate feature allows actions of the + form "%?{ BOOLEAN-EXPRESSION }", which cause syntax errors (as for YYERROR) if the expression evaluates to 0, and are evaluated immediately - in GLR parsers, rather than being deferred. The result is that they - allow the programmer to prune possible parses based on the values of - run-time expressions. + in GLR parsers, rather than being deferred. The result is that they allow + the programmer to prune possible parses based on the values of run-time + expressions. * Noteworthy changes in release ?.? (????-??-??) [?] +* Noteworthy changes in release 2.6.2 (2012-08-03) [stable] + +** Bug fixes + + Buffer overruns, complaints from Flex, and portability issues in the test + suite have been fixed. + +** Spaces in %lex- and %parse-param (lalr1.cc, glr.cc) + + Trailing end-of-lines in %parse-param or %lex-param would result in + invalid C++. This is fixed. + +** Spurious spaces and end-of-lines + + The generated files no longer end (nor start) with empty lines. + +* Noteworthy changes in release 2.6.1 (2012-07-30) [stable] + + Bison no longer executes user-specified M4 code when processing a grammar. + +** Future Changes + + In addition to the removal of the features announced in Bison 2.6, the + next major release will remove the "Temporary hack for adding a semicolon + to the user action", as announced in the release 2.5. Instead of: + + exp: exp "+" exp { $$ = $1 + $3 }; + + write: + + exp: exp "+" exp { $$ = $1 + $3; }; + +** Bug fixes + +*** Type names are now properly escaped. + +*** glr.cc: set_debug_level and debug_level work as expected. + +*** Stray @ or $ in actions + + While Bison used to warn about stray $ or @ in action rules, it did not + for other actions such as printers, destructors, or initial actions. It + now does. + +** Type names in actions + + For consistency with rule actions, it is now possible to qualify $$ by a + type-name in destructors, printers, and initial actions. For instance: + + %printer { fprintf (yyo, "(%d, %f)", $$, $$); } <*> <>; + + will display two values for each typed and untyped symbol (provided + that YYSTYPE has both "ival" and "fval" fields). + * Noteworthy changes in release 2.6 (2012-07-19) [stable] ** Future changes: @@ -129,7 +209,7 @@ GNU Bison NEWS The next major release of Bison will drop support for the following deprecated features. Please report disagreements to bug-bison@gnu.org. -*** K&C parsers +*** K&R C parsers Support for generating parsers in K&R C will be removed. Parsers generated for C support ISO C90, and are tested with ISO C99 and ISO C11