X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/5202b6ac1d3662fe283240aab1b29f35607995cd..3e82dfaa0dedffdfdc948a971deee3cbd2d965ba:/NEWS diff --git a/NEWS b/NEWS index 3bfc1f94..2e38038e 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,125 @@ GNU Bison NEWS * Noteworthy changes in release ?.? (????-??-??) [?] +** Bug fixes + +*** C++ with Variants (lalr1.cc) + + Fix a compiler warning when no %destructor use $$. + +* Noteworthy changes in release 3.0.3 (2015-01-15) [stable] + +** Bug fixes + +*** C++ with Variants (lalr1.cc) + + Problems with %destructor and '%define parse.assert' have been fixed. + +*** Named %union support (yacc.c, glr.c) + + Bison 3.0 introduced a regression on named %union such as + + %union foo { int ival; }; + + The possibility to use a name was introduced "for Yacc compatibility". + It is however not required by POSIX Yacc, and its usefulness is not clear. + +*** %define api.value.type union with %defines (yacc.c, glr.c) + + The C parsers were broken when %defines was used together with "%define + api.value.type union". + +*** Redeclarations are reported in proper order + + On + + %token FOO "foo" + %printer {} "foo" + %printer {} FOO + + bison used to report: + + /tmp/foo.yy:2.10-11: error: %printer redeclaration for FOO + %printer {} "foo" + ^^ + /tmp/foo.yy:3.10-11: previous declaration + %printer {} FOO + ^^ + + Now, the "previous" declaration is always the first one. + + +** Documentation + + Bison now installs various files in its docdir (which defaults to + '/usr/local/share/doc/bison'), including the three fully blown examples + extracted from the documentation: + + - rpcalc + Reverse polish calculator, a simple introductory example. + - mfcalc + Multi-function Calc, a calculator with memory and functions and located + error messages. + - calc++ + a calculator in C++ using variant support and token constructors. + +* Noteworthy changes in release 3.0.2 (2013-12-05) [stable] + +** Bug fixes + +*** Generated source files when errors are reported + + When warnings are issued and -Werror is set, bison would still generate + the source files (*.c, *.h...). As a consequence, some runs of "make" + could fail the first time, but not the second (as the files were generated + anyway). + + This is fixed: bison no longer generates this source files, but, of + course, still produces the various reports (*.output, *.xml, etc.). + +*** %empty is used in reports + + Empty right-hand sides are denoted by '%empty' in all the reports (text, + dot, XML and formats derived from it). + +*** YYERROR and variants + + When C++ variant support is enabled, an error triggered via YYERROR, but + not caught via error recovery, resulted in a double deletion. + +* Noteworthy changes in release 3.0.1 (2013-11-12) [stable] + +** Bug fixes + +*** Errors in caret diagnostics + + On some platforms, some errors could result in endless diagnostics. + +*** Fixes of the -Werror option + + Options such as "-Werror -Wno-error=foo" were still turning "foo" + diagnostics into errors instead of warnings. This is fixed. + + Actually, for consistency with GCC, "-Wno-error=foo -Werror" now also + leaves "foo" diagnostics as warnings. Similarly, with "-Werror=foo + -Wno-error", "foo" diagnostics are now errors. + +*** GLR Predicates + + As demonstrated in the documentation, one can now leave spaces between + "%?" and its "{". + +*** Installation + + The yacc.1 man page is no longer installed if --disable-yacc was + specified. + +*** Fixes in the test suite + + Bugs and portability issues. + +* Noteworthy changes in release 3.0 (2013-07-25) [stable] + ** WARNING: Future backward-incompatibilities! Like other GNU packages, Bison will start using some of the C99 features @@ -23,6 +142,26 @@ GNU Bison NEWS Missing semicolons at the end of actions are no longer added (as announced in the release 2.5). +*** Use of YACC='bison -y' + + TL;DR: With Autoconf <= 2.69, pass -Wno-yacc to (AM_)YFLAGS if you use + Bison extensions. + + Traditional Yacc generates 'y.tab.c' whatever the name of the input file. + Therefore Makefiles written for Yacc expect 'y.tab.c' (and possibly + 'y.tab.h' and 'y.outout') to be generated from 'foo.y'. + + To this end, for ages, AC_PROG_YACC, Autoconf's macro to look for an + implementation of Yacc, was using Bison as 'bison -y'. While it does + ensure compatible output file names, it also enables warnings for + incompatibilities with POSIX Yacc. In other words, 'bison -y' triggers + warnings for Bison extensions. + + Autoconf 2.70+ fixes this incompatibility by using YACC='bison -o y.tab.c' + (which also generates 'y.tab.h' and 'y.output' when needed). + Alternatively, disable Yacc warnings by passing '-Wno-yacc' to your Yacc + flags (YFLAGS, or AM_YFLAGS with Automake). + ** Bug fixes *** The epilogue is no longer affected by internal #defines (glr.c) @@ -42,6 +181,8 @@ GNU Bison NEWS Changes in Bison 2.7 introduced a dependency on FILE and fprintf when locations are enabled. This is fixed. +*** Warnings about useless %pure-parser/%define api.pure are restored + ** Diagnostics reported by Bison Most of these features were contributed by Théophile Ranquet and Victor @@ -236,6 +377,23 @@ GNU Bison NEWS %param {arg1_type *arg1} {arg2_type *arg2} +** Types of values for %define variables + + Bison used to make no difference between '%define foo bar' and '%define + foo "bar"'. The former is now called a 'keyword value', and the latter a + 'string value'. A third kind was added: 'code values', such as '%define + foo {bar}'. + + Keyword variables are used for fixed value sets, e.g., + + %define lr.type lalr + + Code variables are used for value in the target language, e.g., + + %define api.value.type {struct semantic_type} + + String variables are used remaining cases, e.g. file names. + ** Variable api.token.prefix The variable api.token.prefix changes the way tokens are identified in @@ -243,7 +401,7 @@ GNU Bison NEWS with identifiers in the target language. For instance %token FILE for ERROR - %define api.token.prefix "TOK_" + %define api.token.prefix {TOK_} %% start: FILE for ERROR; @@ -252,6 +410,79 @@ GNU Bison NEWS use these prefixed token names, although the grammar itself still uses the short names (as in the sample rule given above). +** Variable api.value.type + + This new %define variable supersedes the #define macro YYSTYPE. The use + of YYSTYPE is discouraged. In particular, #defining YYSTYPE *and* either + using %union or %defining api.value.type results in undefined behavior. + + Either define api.value.type, or use "%union": + + %union + { + int ival; + char *sval; + } + %token INT "integer" + %token STRING "string" + %printer { fprintf (yyo, "%d", $$); } + %destructor { free ($$); } + + /* In yylex(). */ + yylval.ival = 42; return INT; + yylval.sval = "42"; return STRING; + + The %define variable api.value.type supports both keyword and code values. + + The keyword value 'union' means that the user provides genuine types, not + union member names such as "ival" and "sval" above (WARNING: will fail if + -y/--yacc/%yacc is enabled). + + %define api.value.type union + %token INT "integer" + %token STRING "string" + %printer { fprintf (yyo, "%d", $$); } + %destructor { free ($$); } + + /* In yylex(). */ + yylval.INT = 42; return INT; + yylval.STRING = "42"; return STRING; + + The keyword value variant is somewhat equivalent, but for C++ special + provision is made to allow classes to be used (more about this below). + + %define api.value.type variant + %token INT "integer" + %token STRING "string" + + Code values (in braces) denote user defined types. This is where YYSTYPE + used to be used. + + %code requires + { + struct my_value + { + enum + { + is_int, is_string + } kind; + union + { + int ival; + char *sval; + } u; + }; + } + %define api.value.type {struct my_value} + %token INT "integer" + %token STRING "string" + %printer { fprintf (yyo, "%d", $$); } + %destructor { free ($$); } + + /* In yylex(). */ + yylval.u.ival = 42; return INT; + yylval.u.sval = "42"; return STRING; + ** Variable parse.error This variable controls the verbosity of error messages. The use of the @@ -404,11 +635,13 @@ GNU Bison NEWS ** Java skeleton improvements - Contributed by Paolo Bonzini. - 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". + Contributed by Paolo Bonzini. + + The Java skeleton now supports push parsing. + Contributed by Dennis Heimbigner. ** C++ skeletons improvements @@ -477,6 +710,21 @@ GNU Bison NEWS ... } +*** C++ locations + + There are operator- and operator-= for 'location'. Negative line/column + increments can no longer underflow the resulting value. + +* Noteworthy changes in release 2.7.1 (2013-04-15) [stable] + +** Bug fixes + +*** Fix compiler attribute portability (yacc.c) + + With locations enabled, __attribute__ was used unprotected. + +*** Fix some compiler warnings (lalr1.cc) + * Noteworthy changes in release 2.7 (2012-12-12) [stable] ** Bug fixes @@ -2496,7 +2744,7 @@ Output file does not redefine const for C++. ----- -Copyright (C) 1995-2013 Free Software Foundation, Inc. +Copyright (C) 1995-2015 Free Software Foundation, Inc. This file is part of Bison, the GNU Parser Generator. @@ -2536,7 +2784,7 @@ along with this program. If not, see . LocalWords: Wprecedence Rassoul Wempty Paolo Bonzini parser's Michiel loc LocalWords: redeclaration sval fcaret reentrant XSLT xsl Wmaybe yyvsp Tedi LocalWords: pragmas noreturn untyped Rozenman unexpanded Wojciech Polak - LocalWords: Alexandre MERCHANTABILITY + LocalWords: Alexandre MERCHANTABILITY yytype Local Variables: mode: outline