X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f Message-Id: <200605221729.k4MHTXuo023031@delorie.com> X-Authenticated: #27081556 From: Juan Manuel Guerrero To: djgpp-announce AT delorie DOT com Subject: ANNOUNCE: DJGPP port of GNU bison 2.2 uploaded. Date: Mon, 22 May 2006 19:23:34 +0200 Content-Disposition: inline X-Y-GMX-Trusted: 0 This is a port of GNU Bison 2.2 to MSDOS/DJGPP. Bison is a Yacc compatible parser generator. DJGPP specific changes. ======================= - The DJGPP port of Bison offers LFN and SFN support depending on which OS it is running. If LFN support is available or not is determinated at run time. If LFN support is available (DOS session under Win9X), the standard posix file name extensions will be used. These are: y.tab.c, y.tab.c++, y.tab.h, y.output, etc. If only SFN support is available (plain DOS), then the standard MSDOS short file names will be used. These are: y_tab.c, y_tab.h, y.out, etc. - It should be noticed that this version of Bison uses the m4 program as a backend to generate the parser file (e.g. y_tab.c, etc.) from the skeleton files. This means that m4 *must* be installed and available when bison's is invoked or bison will not be able to generate the parser file. m4 will use a couple m4 scripts that will be installed in /dev/env/DJDIR/share/bison. This version of bison requires at least m4 1.4.3 available as m4-143b.zip at ftp://ftp.delorie.com and mirrors. - It should also be noticed that the two skeleton files bison.simple and bison.hairy are no longer used nor supported anymore. This applies also to the two environment variables BISON_HAIRY and BISON_SIMPLE. Those variables are *no* longer honored at all. This implies that you can no longer use these variables to point bison to an alternative skeleton file. Use the command line option `-S' instead. - The skeleton file bison.simple is now called yacc.c and is an m4 script. Please notice that the grammar type coded in the skeleton file bison.hairy is no longer supported by the bison maintainer. The other two skeleton files supported by this bison version are glr.c and lalr1.cc. The first one is a generalized LR C parser based on Bison's LALR(1) tables and the second one is a experimental C++ parser class. Here is a list of user-visible changes in version 2.2. taken from the NEWS file: * The distribution terms for all Bison-generated parsers now permit using the parsers in nonfree programs. Previously, this permission was granted only for Bison-generated LALR(1) parsers in C. * %name-prefix changes the namespace name in C++ outputs. * The C++ parsers export their token_type. * Bison now allows multiple %union declarations, and concatenates their contents together. * New warning: unused values 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 ; 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 could be rewritten as: 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, 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; } ; If there are mid-rule actions, the warning is issued if no action uses it. The following triggers no warning: $1 and $3 are used. exp: exp { push ($1); } '+' exp { push ($3); sum (); }; The warning is intended to help catching lost values and memory leaks. If a value is ignored, its associated memory typically is not reclaimed. * %destructor vs. YYABORT, YYACCEPT, and YYERROR. Destructors are now called when user code invokes YYABORT, YYACCEPT, and YYERROR, for all objects on the stack, other than objects corresponding to the right-hand side of the current rule. * %expect, %expect-rr Incorrect numbers of expected conflicts are now actual errors, instead of warnings. * GLR, YACC parsers. The %parse-params are available in the destructors (and the experimental printers) as per the documentation. * Bison now warns if it finds a stray `$' or `@' in an action. * %require "VERSION" 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 was defined as a free form union. They are now class members: tokens are enumerations of the `yy::parser::token' struct, and the semantic values have the `yy::parser::semantic_type' type. If you do not want or can update to this scheme, the directive `%define "global_tokens_and_yystype" "1"' triggers the global definition of tokens and YYSTYPE. This change is suitable both for previous releases of Bison, and this one. If you wish to update, then make sure older version of Bison will fail using `%require "2.2"'. * DJGPP support added. For futher information about GNU bison please read the info docs and NEWS file. Please also note that the testsuite will only work if LFN are available. Two tests will be skipped (131 and 132). No other tests should fail. The port consists of the usual three packages that have been compiled using stock djdev203 and that can be downloaded from ftp.delorie.com and mirrors as (timestamp 2006-05-22): Bison 2.2 binary, info and man format documentation: ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bsn22b.zip Bison 2.2 dvi, html, ps and pdf format documentation: ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bsn22d.zip Bison 2.2 source: ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bsn22s.zip For the convenience of the WinXP users the binaries has been produced a second time using the djdev204 beta library. This package is available at ftp.delorie.com and mirrors as (timestamp 2006-05-22): Bison 2.2 binary, info and man format documentation: ftp://ftp.delorie.com/pub/djgpp/beta/v2gnu/bsn22b.zip Send GNU bison specific bug reports to . Send suggestions and bug reports concerning the DJGPP port to comp.os.msdos.djgpp or . Enjoy. Guerrero, Juan Manuel