Bison News
----------
-Changes in version 1.875a:
+Changes in version 1.875f:
-* %expect-count violations are now just warnings, not errors, for
- compatibility with Bison 1.75 and earlier (when there are
+* Bison-generated parsers no longer default to using the alloca function
+ (when available) to extend the parser stack, due to widespread
+ problems in unchecked stack-overflow detection. You can "#define
+ YYSTACK_USE_ALLOCA 1" to use alloca anyway, but please read the
+ manual to determine safe values for YYMAXDEPTH in that case.
+
+Changes in version 1.875e, 2004-12-10:
+
+* New directive: %initial-action.
+ This directive allows the user to run arbitrary code (including
+ initializing @$) from yyparse before parsing starts.
+
+* The option `--report=lookahead' was changed to `--report=look-ahead'.
+ The old spelling still works, but is not documented and will be
+ removed.
+
+* Error token location.
+ During error recovery, the location of the syntax error is updated
+ to cover the whole sequence covered by the error token: it includes
+ the shifted symbols thrown away during the first part of the error
+ recovery, and the lookahead rejected during the second part.
+
+* Goto numbers are no longer arbitrarily limited to 16-bit counts.
+
+Changes in version 1.875d, 2004-05-21:
+
+* Unescaped newlines are no longer allowed in character constants or
+ string literals. They were never portable, and GCC 3.4.0 has
+ dropped support for them. Better diagnostics are now generated if
+ forget a closing quote.
+
+* NUL bytes are no longer allowed in Bison string literals, unfortunately.
+
+* %token numbers can now be hexadecimal integers, e.g., `%token FOO 0x12d'.
+ This is a GNU extension.
+
+* A new directive "%expect-rr N" specifies the expected number of
+ reduce/reduce conflicts in GLR parsers.
+
+* Experimental %destructor support has been added to lalr1.cc.
+
+Changes in version 1.875c, 2003-08-25:
+
+ (Just bug fixes.)
+
+Changes in version 1.875b, 2003-06-17:
+
+* GLR grammars now support locations.
+
+* Semicolon changes:
+ - Semicolons are now allowed before "|" in grammar rules, as POSIX requires.
+ - Stray semicolons are no longer allowed at the start of a grammar.
+ - Semicolons are now required after in-grammar declarations.
+
+Changes in version 1.875a, 2003-02-01:
+
+* For now, %expect-count violations are now just warnings, not errors.
+ This is for compatibility with Bison 1.75 and earlier (when there are
reduce/reduce conflicts) and with Bison 1.30 and earlier (when there
- are too many or too few shift/reduce conflicts).
+ are too many or too few shift/reduce conflicts). However, in future
+ versions of Bison we plan to improve the %expect machinery so that
+ these violations will become errors again.
* New configure option --disable-yacc, to disable installation of the
yacc command and -ly library introduced in 1.875 for POSIX conformance.
allowed some non-error action other than a default reduction on the
error token. The new behavior has long been the documented behavior,
and has long been required by POSIX. For more details, please see
- <http://mail.gnu.org/pipermail/bug-bison/2002-May/001452.html>.
+ Paul Eggert, "Reductions during Bison error handling" (2002-05-20)
+ <http://lists.gnu.org/archive/html/bug-bison/2002-05/msg00038.html>.
* Traces
Popped tokens and nonterminals are now reported.
produces additional information:
- itemset
complete the core item sets with their closure
- - lookahead
- explicitly associate lookaheads to items
+ - lookahead [changed to `look-ahead' in 1.875e and later]
+ explicitly associate look-ahead tokens to items
- solved
describe shift/reduce conflicts solving.
Bison used to systematically output this information on top of
-----
-Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
+Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.