X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/c046698e6e98aefa7f234b8035fe4cf20ce5d05d..4bb975e1ad59a39460fe6b16eec5c7830f904b6b:/NEWS?ds=sidebyside

diff --git a/NEWS b/NEWS
index 65781606..57db6c2d 100644
--- a/NEWS
+++ b/NEWS
@@ -33,19 +33,26 @@ Bison News
   These features are experimental.  More user feedback will help to
   stabilize them.
 
+** Multiple %define's for any variable is now an error not a warning.
+
 ** %define can now be invoked via the command line.
 
-  Each of these bison command-line options
+  Each of these command-line options
+
+    -D NAME[=VALUE]
+    --define=NAME[=VALUE]
 
-    -D NAME=VALUE
-    --define=NAME=VALUE
+    -F NAME[=VALUE]
+    --force-define=NAME[=VALUE]
 
   is equivalent to this grammar file declaration
 
-    %define NAME "VALUE"
+    %define NAME ["VALUE"]
 
-  for any NAME and VALUE.  Omitting `=VALUE' on the command line is
-  equivalent to omitting `"VALUE"' in the declaration.
+  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.
 
 ** %define variables renamed.
 
@@ -91,8 +98,32 @@ Bison News
   about a missing semicolon where it did not before.  Future releases of
   Bison will cease to append semicolons entirely.
 
+** Character literals not of length one.
+
+  Previously, Bison quietly converted all character literals to length
+  one.  For example, without warning, Bison interpreted the operators in
+  the following grammar to be the same token:
+
+    exp: exp '++'
+       | exp '+' exp
+       ;
+
+  Bison now warns when a character literal is not of length one.  In
+  some future release, Bison will report an error instead.
+
+** Verbose error messages fixed for nonassociative tokens.
+
+  When %error-verbose is specified, syntax error messages produced by
+  the generated parser include the unexpected token as well as a list of
+  expected tokens.  Previously, this list erroneously included tokens
+  that would actually induce a syntax error because conflicts for them
+  were resolved with %nonassoc.  Such tokens are now properly omitted
+  from the list.
+
 * Changes in version 2.4.2 (????-??-??):
 
+** Detection of GNU M4 1.4.6 or newer during configure is improved.
+
 ** %code is now a permanent feature.
 
   A traditional Yacc prologue directive is written in the form: