build: avoid ignored errors.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index fe80c6ff07100b139fe3cecf62f439d96a83ef13..3c99a876e4d9009570b7a7d691bd05879b2ce744 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,22 @@ Bison News
   Also, it is possible to add code to the parser's constructors using
   "%code init" and "%define init_throws".
 
+** Variable api.tokens.prefix
+
+  The variable api.tokens.prefix changes the way tokens are identified in
+  the generated files.  This is especially useful to avoid collisions
+  with identifiers in the target language.  For instance
+
+      %token FILE for ERROR
+      %define api.tokens.prefix "TOK_"
+      %%
+      start: FILE for ERROR;
+
+  will generate the definition of the symbols TOK_FILE, TOK_for, and
+  TOK_ERROR in the generated sources.  In particular, the scanner must
+  use these prefixed token names, although the grammar itself still
+  uses the short names (as in the sample rule given above).
+
 * Changes in version 2.5 (????-??-??):
 
 ** IELR(1) and Canonical LR(1) Support
@@ -41,19 +57,26 @@ 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.
 
@@ -70,6 +93,14 @@ Bison News
   The old names are now deprecated but will be maintained indefinitely
   for backward compatibility.
 
+** Symbols names
+
+  Consistently with directives (such as %error-verbose) and variables
+  (e.g. push-pull), symbol names may include dashes in any position,
+  similarly to periods and underscores.  This is GNU extension over
+  POSIX Yacc whose use is reported by -Wyacc, and rejected in Yacc
+  mode (--yacc).
+
 ** Temporary hack for adding a semicolon to the user action.
 
   Previously, Bison appended a semicolon to every user action for