Bison News
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-* Changes in version 2.5 (????-??-??):
+* Changes in version 2.5.1 (????-??-??):
+
+** Future changes:
+
+ The next major release will drop support for K&R C.
+
+** yacc.c: YYBACKUP works as expected.
+
+** glr.c improvements:
+
+*** Location support is eliminated when not requested:
+
+ GLR parsers used to include location-related code even when
+ locations were not requested, and therefore not even usable.
+
+*** __attribute__ is preserved:
+
+ __attribute__ is no longer disabled when __STRICT_ANSI__ is defined
+ (i.e., when -std is passed to GCC).
+
+** lalr1.java: several fixes:
+
+ The Java parser no longer throws ArrayIndexOutOfBoundsException if
+ the first token leads to a syntax error. Some minor clean ups.
+
+** C++11 compatibility:
+
+ C and C++ parsers use nullptr instead of 0 when __cplusplus is
+ 201103L or higher.
+
+** C++ locations:
+
+ The position and location constructors (and their initialize
+ methods) accept new arguments for line and column. Several issues
+ in the documentation were fixed.
+
+** liby is no longer asking for "rpl_fprintf" on some platforms.
+
+** Several improvements have been made to the manual:
+
+ The layout for grammar excerpts was changed to a more compact
+ scheme. Named references are motivated. The description of the
+ automaton description file (*.output) is updated to the current
+ format. Incorrect index entries were fixed. Some other errors were
+ fixed.
+
+** Warnings during the build procedure have been eliminated.
+
+** Several portability problems in the test suite have been fixed:
+
+ This includes warnings with some compilers, unexpected behavior of
+ tools such as diff, warning messages from the test suite itself,
+ etc.
+
+* Changes in version 2.5 (2011-05-14):
** Grammar symbol names can now contain non-initial dashes:
When no ambiguity is possible, original symbol names may be used
as named references:
- if_stmt : 'if' cond_expr 'then' then_stmt ';'
+ if_stmt : "if" cond_expr "then" then_stmt ';'
{ $if_stmt = mk_if_stmt($cond_expr, $then_stmt); }
In the more common case, explicit names may be declared:
- stmt[res] : 'if' expr[cond] 'then' stmt[then] 'else' stmt[else] ';'
+ stmt[res] : "if" expr[cond] "then" stmt[then] "else" stmt[else] ';'
{ $res = mk_if_stmt($cond, $then, $else); }
Location information is also accessible using @name syntax. When
IELR(1) is a minimal LR(1) parser table generation algorithm. That
is, given any context-free grammar, IELR(1) generates parser tables
- with the full language recognition power of canonical LR(1) but with
+ with the full language-recognition power of canonical LR(1) but with
nearly the same number of parser states as LALR(1). This reduction
in parser states is often an order of magnitude. More importantly,
because canonical LR(1)'s extra parser states may contain duplicate
except that the manner in which Bison processes multiple definitions
for the same NAME differs. Most importantly, -F and --force-define
quietly override %define, but -D and --define do not. For further
- details, see the section "Bison Options" in the Bison manual.
+ details, see the section `Bison Options' in the Bison manual.
*** Variables renamed:
The old names are now deprecated but will be maintained indefinitely
for backward compatibility.
-*** Values no longer need to be quoted in grammar file:
+*** Values no longer need to be quoted in the grammar file:
If a %define value is an identifier, it no longer needs to be placed
within quotations marks. For example,
Similarly to the C parsers, the C++ parsers now define the YYRHSLOC
macro and use it in the default YYLLOC_DEFAULT. You are encouraged
- to use it. If, for instance, your location structure has "first"
- and "last" members, instead of
+ to use it. If, for instance, your location structure has `first'
+ and `last' members, instead of
# define YYLLOC_DEFAULT(Current, Rhs, N) \
do \
in order to detect a syntax error. Because no unexpected token or
expected tokens can then be reported, the verbose syntax error
message described above is suppressed, and the parser instead
- reports the simpler message, "syntax error". Previously, this
+ reports the simpler message, `syntax error'. Previously, this
suppression was sometimes erroneously triggered by %nonassoc when a
lookahead was actually required. Now verbose messages are
suppressed only when all previous lookaheads have already been
*** Parser traces now print the top element of the stack.
+** -W/--warnings fixes:
+
+*** Bison now properly recognizes the `no-' versions of categories:
+
+ For example, given the following command line, Bison now enables all
+ warnings except warnings for incompatibilities with POSIX Yacc:
+
+ bison -Wall,no-yacc gram.y
+
+*** Bison now treats S/R and R/R conflicts like other warnings:
+
+ Previously, conflict reports were independent of Bison's normal
+ warning system. Now, Bison recognizes the warning categories
+ `conflicts-sr' and `conflicts-rr'. This change has important
+ consequences for the -W and --warnings command-line options. For
+ example:
+
+ bison -Wno-conflicts-sr gram.y # S/R conflicts not reported
+ bison -Wno-conflicts-rr gram.y # R/R conflicts not reported
+ bison -Wnone gram.y # no conflicts are reported
+ bison -Werror gram.y # any conflict is an error
+
+ However, as before, if the %expect or %expect-rr directive is
+ specified, an unexpected number of conflicts is an error, and an
+ expected number of conflicts is not reported, so -W and --warning
+ then have no effect on the conflict report.
+
+*** The `none' category no longer disables a preceding `error':
+
+ For example, for the following command line, Bison now reports
+ errors instead of warnings for incompatibilities with POSIX Yacc:
+
+ bison -Werror,none,yacc gram.y
+
+*** The `none' category now disables all Bison warnings:
+
+ Previously, the `none' category disabled only Bison warnings for
+ which there existed a specific -W/--warning category. However,
+ given the following command line, Bison is now guaranteed to
+ suppress all warnings:
+
+ bison -Wnone gram.y
+
+** Precedence directives can now assign token number 0:
+
+ Since Bison 2.3b, which restored the ability of precedence
+ directives to assign token numbers, doing so for token number 0 has
+ produced an assertion failure. For example:
+
+ %left END 0
+
+ This bug has been fixed.
+
* Changes in version 2.4.3 (2010-08-05):
** Bison now obeys -Werror and --warnings=error for warnings about
-----
-Copyright (C) 1995-2011 Free Software Foundation, Inc.
+Copyright (C) 1995-2012 Free Software Foundation, Inc.
This file is part of Bison, the GNU Parser Generator.
projects / bison.git / blobdiff