X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/84866159725a9df9febc1050643c0355eba5916c..f5d5ecdfaf97b891f6a634cc58817496a2e0faf8:/NEWS diff --git a/NEWS b/NEWS index 784efeb7..4de67f10 100644 --- a/NEWS +++ b/NEWS @@ -1,11 +1,20 @@ Bison News ---------- -Changes in version 2.1a: +Changes in version 2.1b: + +* %name-prefix changes the namespace name in C++ outputs. + +* The C++ parsers export their token_type. + +Changes in version 2.1a, 2006-02-13: + +* Bison now allows multiple %union declarations, and concatenates + their contents together. * New warning: unused values - Typed right-hand side symbols whose value are not used are reported. - For instance: + Right-hand side symbols whose values are not used are reported, + if the symbols have destructors. For instance: exp: exp "?" exp ":" exp { $1 ? $1 : $3; } | exp "+" exp @@ -13,14 +22,17 @@ Changes in version 2.1a: will trigger a warning about $$ and $5 in the first rule, and $3 in the second ($1 is copied to $$ by the default rule). This example - most likely contains three errors, and should be rewritten as: + most likely contains three errors, and could be rewritten as: - exp: exp "?" exp ":" exp { $$ = $1 ? $3 : $5; } - | exp "+" exp { $$ = $1 + $3; } + exp: exp "?" exp ":" exp + { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); } + | exp "+" exp + { $$ = $1 ? $1 : $3; if ($1) free ($3); } ; - However, if the original actions were really intended, the warnings - can be suppressed by letting Bison believe the values are used, e.g.: + However, if the original actions were really intended, memory leaks + and all, the warnings can be suppressed by letting Bison believe the + values are used, e.g.: exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); } | exp "+" exp { $$ = $1; (void) $3; } @@ -31,12 +43,6 @@ Changes in version 2.1a: exp: exp { push ($1); } '+' exp { push ($3); sum (); }; - Mid-rule actions that use $$ cause the corresponding value to be - set, therefore the following action must use it. The following rule - triggers a warning about $2. - - exp: '1' { $$ = 1; } '+' exp { $$ = $1 + $4; }; - The warning is intended to help catching lost values and memory leaks. If a value is ignored, its associated memory typically is not reclaimed. @@ -50,14 +56,14 @@ Changes in version 2.1a: instead of warnings. * GLR, YACC parsers. - The %parse-params are available in the %destructor's (and the - experimental %printer's) as per the documentation. + The %parse-params are available in the destructors (and the + experimental printers) as per the documentation. * Bison now warns if it finds a stray `$' or `@' in an action. * %require "VERSION" - To specify that the grammar file depends on features implemented in - Bison version VERSION or higher. + This specifies that the grammar file depends on features implemented + in Bison version VERSION or higher. * lalr1.cc: The token and value types are now class members. The tokens were defined as free form enums and cpp macros. YYSTYPE @@ -695,8 +701,8 @@ End: ----- -Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 -Free Software Foundation, Inc. +Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, +2004, 2005, 2006 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler.