X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/4b3847c3c0e161b85267d077adb256a880c0f3e3..db8ab2be3337ef87629b761078ebc46a01e7f876:/NEWS diff --git a/NEWS b/NEWS index 371b9333..a20898fc 100644 --- a/NEWS +++ b/NEWS @@ -2,15 +2,149 @@ GNU Bison NEWS * Noteworthy changes in release ?.? (????-??-??) [?] -** Future changes +** Bug fixes + + Bugs and portability issues in the test suite have been fixed. + + Some errors in translations have been addressed, and --help now directs + users to the appropriate place to report them. + + Stray Info files shipped by accident are removed. + + Incorrect definitions of YY_, issued by yacc.c when no parser header is + generated, are removed. + + All the generated headers are self-contained. + +** Changes in the format of error messages + + This used to be the format of many error reports: + + foo.y:5.10-24: result type clash on merge function 'merge': != + foo.y:4.13-27: previous declaration + + It is now: + + foo.y:5.10-25: result type clash on merge function 'merge': != + foo.y:4.13-27: previous declaration + +** Header guards (yacc.c, glr.c, glr.cc) + + In order to avoid collisions, the header guards are now + YY___INCLUDED, instead of merely _. + For instance the header generated from + + %define api.prefix "calc" + %defines "lib/parse.h" + + will use YY_CALC_LIB_PARSE_H_INCLUDED as guard. + +** Exception safety (lalr1.cc) + + The parse function now catches exceptions, uses the %destructors to + release memory (the lookahead symbol and the symbols pushed on the stack) + before rethrowing the exception. + + This feature is somewhat experimental. User feedback would be + appreciated. + +** Fix compiler warnings in the generated parser (yacc.c, glr.c) + + The compilation of pure parsers (%define api.pure) can trigger GCC + warnings such as: + + input.c: In function 'yyparse': + input.c:1503:12: warning: 'yylval' may be used uninitialized in this + function [-Wmaybe-uninitialized] + *++yyvsp = yylval; + ^ + + This is now fixed; pragmas to avoid these warnings are no longer needed. + + Warnings from clang ("equality comparison with extraneous parentheses" and + "function declared 'noreturn' should not return") have also been + addressed. + +** New %define variable: api.location.type (glr.cc, lalr1.cc) + + The %define variable api.location.type defines the name of the type to use + for locations. When defined, Bison no longer generates the position.hh + and location.hh files, nor does the parser will include them: the user is + then responsible to define her type. + + This can be used in programs with several parsers to factor their location + and position files: let one of them generate them, and let the others + simply resue these types and files. + + This feature was actually introduced, but not documented, in Bison 2.5, + under the name "location_type" (which is maintained for backward + compatibility). + +* 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 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 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. *** Features deprecated since Bison 1.875 @@ -32,12 +166,12 @@ GNU Bison NEWS because existing versions of ylwrap (e.g., Automake 1.12.1) do not support it. -** Headers +** Generated Parser Headers *** 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 @@ -94,10 +228,19 @@ GNU Bison NEWS # define BAR_FOO_H # define BAR_FOO_H /* Enabling traces. */ /* Enabling traces. */ - # ifndef YYDEBUG # ifndef YYDEBUG - # define YYDEBUG 0 # define YYDEBUG 0 - # endif # endif - # if YYDEBUG # if YYDEBUG + # 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 @@ -1292,7 +1435,7 @@ GNU Bison NEWS - 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. @@ -1790,9 +1933,11 @@ along with this program. If not, see . 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 calc yyo fval Local Variables: mode: outline