* Noteworthy changes in release ?.? (????-??-??) [?]
-** Warnings about useless semantic types
+** Incompatible changes
+
+*** Obsolete features
+
+ Support for YYFAIL is removed, as announced since Bison 2.4.2.
+
+** Warnings
+
+*** Warning categories are now displayed in warnings
+
+ For instance:
+
+ foo.y:4.6: warning: type clash on default action: <foo> != <bar> [-Wother]
+
+*** Useless semantic types
Bison now warns about useless (uninhabited) semantic types. Since
semantic types are not declared to Bison (they are defined in the opaque
3.28-34: warning: type <type3> is used, but is not associated to any symbol
4.28-34: warning: type <type4> is used, but is not associated to any symbol
-** Warnings about undeclared symbols
+*** Undeclared symbols
Bison used to raise an error for %printer and %destructor directives for
undefined symbols.
This is now only a warning.
-** Warnings about useless destructors or printers
+*** Useless destructors or printers
Bison now warns about useless destructors or printers. In the following
example, the printer for <type1>, and the destructor for <type2> are
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
- runtime expressions.
+ run-time expressions.
* Noteworthy changes in release ?.? (????-??-??) [?]
-** Future changes
+
+* Noteworthy changes in release 2.6 (2012-07-19) [stable]
+
+** Future changes:
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
Support for generating parsers in K&R C will be removed. Parsers
- generated for C supprt ISO C90, and are tested with ISO C99 and ISO C11
+ generated for C support ISO C90, and are tested with ISO C99 and ISO C11
compilers.
-*** Deprecated features
+*** Features deprecated since Bison 1.875
+
+ The definitions of yystype and yyltype will be removed; use YYSTYPE and
+ YYLTYPE.
- The definitions of yystype and yyltype will be removed, as announced since
- Bison 1.875. Use YYSTYPE and YYLTYPE only.
+ YYPARSE_PARAM and YYLEX_PARAM, deprecated in favor of %parse-param and
+ %lex-param, will no longer be supported.
- YYPARSE_PARAM and YYLEX_PARAM, which were deprecated in favor of
- %parse-param and %lex-param (introduced in Bison 1.875), will no longer be
- supported.
+ Support for the preprocessor symbol YYERROR_VERBOSE will be removed, use
+ %error-verbose.
*** The generated header will be included (yacc.c)
because existing versions of ylwrap (e.g., Automake 1.12.1) do not support
it.
-** Headers (yacc.c, glr.c, glr.cc)
+** Generated Parser Headers
-*** Guards
+*** Guards (yacc.c, glr.c, glr.cc)
The generated headers are now guarded, as is already the case for C++
- parsers (lalr1.cc). For intance, with --defines=foo.h:
+ parsers (lalr1.cc). For instance, with --defines=foo.h:
#ifndef YY_FOO_H
# define YY_FOO_H
...
#endif /* !YY_FOO_H */
-*** New declarations
+*** New declarations (yacc.c, glr.c)
The generated header now declares yydebug and yyparse. Both honor
--name-prefix=bar_, and yield
in order to facilitate the inclusion of several parser headers inside a
single compilation unit.
+*** Exported symbols in C++
+
+ The symbols YYTOKEN_TABLE and YYERROR_VERBOSE, which were defined in the
+ header, are removed, as they prevent the possibility of including several
+ generated headers from a single compilation unit.
+
+*** YYLSP_NEEDED
+
+ For the same reasons, the undocumented and unused macro YYLSP_NEEDED is no
+ longer defined.
+
+** New %define variable: api.prefix
+
+ Now that the generated headers are more complete and properly protected
+ against multiple inclusions, constant names, such as YYSTYPE are a
+ problem. While yyparse and others are properly renamed by %name-prefix,
+ YYSTYPE, YYDEBUG and others have never been affected by it. Because it
+ would introduce backward compatibility issues in projects not expecting
+ YYSTYPE to be renamed, instead of changing the behavior of %name-prefix,
+ it is deprecated in favor of a new %define variable: api.prefix.
+
+ The following examples compares both:
+
+ %name-prefix "bar_" | %define api.prefix "bar_"
+ %token <ival> FOO %token <ival> FOO
+ %union { int ival; } %union { int ival; }
+ %% %%
+ exp: 'a'; exp: 'a';
+
+ bison generates:
+
+ #ifndef BAR_FOO_H #ifndef BAR_FOO_H
+ # define BAR_FOO_H # define BAR_FOO_H
+
+ /* Enabling traces. */ /* Enabling traces. */
+ # ifndef YYDEBUG | # ifndef BAR_DEBUG
+ > # if defined YYDEBUG
+ > # if YYDEBUG
+ > # define BAR_DEBUG 1
+ > # else
+ > # define BAR_DEBUG 0
+ > # endif
+ > # else
+ # define YYDEBUG 0 | # define BAR_DEBUG 0
+ > # endif
+ # endif | # endif
+
+ # if YYDEBUG | # if BAR_DEBUG
+ extern int bar_debug; extern int bar_debug;
+ # endif # endif
+
+ /* Tokens. */ /* Tokens. */
+ # ifndef YYTOKENTYPE | # ifndef BAR_TOKENTYPE
+ # define YYTOKENTYPE | # define BAR_TOKENTYPE
+ enum yytokentype { | enum bar_tokentype {
+ FOO = 258 FOO = 258
+ }; };
+ # endif # endif
+
+ #if ! defined YYSTYPE \ | #if ! defined BAR_STYPE \
+ && ! defined YYSTYPE_IS_DECLARED | && ! defined BAR_STYPE_IS_DECLARED
+ typedef union YYSTYPE | typedef union BAR_STYPE
+ { {
+ int ival; int ival;
+ } YYSTYPE; | } BAR_STYPE;
+ # define YYSTYPE_IS_DECLARED 1 | # define BAR_STYPE_IS_DECLARED 1
+ #endif #endif
+
+ extern YYSTYPE bar_lval; | extern BAR_STYPE bar_lval;
+
+ int bar_parse (void); int bar_parse (void);
+
+ #endif /* !BAR_FOO_H */ #endif /* !BAR_FOO_H */
+
* Noteworthy changes in release 2.5.1 (2012-06-05) [stable]
** Future changes:
- a single argument only can be added,
- their types are weak (void *),
- - this context is not passed to anciliary functions such as yyerror,
+ - this context is not passed to ancillary functions such as yyerror,
- only yacc.c parsers support them.
The new %parse-param/%lex-param directives provide a more precise control.
LocalWords: struct yystype DJGPP lex param Haible NUM alloca YYSTACK NUL goto
LocalWords: YYMAXDEPTH Unescaped UCNs YYLTYPE's yyltype typedefs inline Yaccs
LocalWords: Heriyanto Reenable dprec Hilfinger Eggert MYEOF Folle Menezes EOF
- LocalWords: Lackovic define's itemset Groff Gettext malloc NEWS'ed YYDEBUG
+ LocalWords: Lackovic define's itemset Groff Gettext malloc NEWS'ed YYDEBUG YY
LocalWords: namespaces strerror const autoconfiguration Dconst Autoconf's FDL
- LocalWords: Automake TMPDIR LESSEQ
+ LocalWords: Automake TMPDIR LESSEQ ylwrap endif yydebug YYTOKEN YYLSP ival hh
+ LocalWords: extern YYTOKENTYPE TOKENTYPE yytokentype tokentype STYPE lval pdf
+ LocalWords: lang yyoutput dvi html ps POSIX lvalp llocp Wother nterm arg init
+ LocalWords: TOK
Local Variables:
mode: outline
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