POSIX: complain if %prec's token was not defined.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index 5bd64cc1c86bd1b5e1055615a50b8f015a24130a..13b199e6e024d6bf3b190f6b4e302b8caa9a9585 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -169,6 +169,23 @@ Bison News
   POSIX Yacc whose use is reported by -Wyacc, and rejected in Yacc
   mode (--yacc).
 
+** YYFAIL now produces warnings and Java parsers no longer implement it.
+
+  YYFAIL has existed for many years as an undocumented feature of
+  deterministic parsers in C generated by Bison.  More recently, it was
+  a documented feature of Bison's experimental Java parsers.  As
+  promised in Bison 2.4.2's NEWS entry, any appearance of YYFAIL in a
+  semantic action now produces a deprecation warning, and Java parsers
+  no longer implement YYFAIL at all.  For further details, including a
+  discussion of how to suppress C preprocessor warnings about YYFAIL
+  being unused, see the Bison 2.4.2 NEWS entry.
+
+** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately.
+
+  As promised in Bison 2.4.2's NEWS entry, it is now an error if a token
+  that appears after a %prec directive is not defined by %token, %left,
+  %right, or %nonassoc.  This is required by POSIX.
+
 ** Temporary hack for adding a semicolon to the user action.
 
   Previously, Bison appended a semicolon to every user action for
@@ -212,8 +229,25 @@ Bison News
   were resolved with %nonassoc.  Such tokens are now properly omitted
   from the list.
 
+** Destructor calls fixed for lookaheads altered in semantic actions.
+
+  Previously for deterministic parsers in C, if a user semantic action
+  altered yychar, the parser in some cases used the old yychar value to
+  determine which destructor to call for the lookahead upon a syntax
+  error or upon parser return.  This bug has been fixed.
+
 * Changes in version 2.4.2 (????-??-??):
 
+** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately.
+
+  POSIX specifies that an error be reported for any identifier that does
+  not appear on the LHS of a grammar rule and that is not defined by
+  %token, %left, %right, or %nonassoc.  Bison 2.3b and later lost this
+  error report for the case when an identifier appears only after a
+  %prec directive.  It is now restored.  However, for backward
+  compatibility with recent Bison releases, it is only a warning for
+  now.  In Bison 2.5 and later, it will return to being an error.
+
 ** Detection of GNU M4 1.4.6 or newer during configure is improved.
 
 ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS,