Add %define lr.keep_unreachable_states.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index bf260476b0253dd1cc70431f1a5680e021625695..96cfa7a773830c03ccf49634cf384e430031ebda 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -3,8 +3,9 @@ Bison News
 
 Changes in version 2.3a+ (????-??-??):
 
 
 Changes in version 2.3a+ (????-??-??):
 

-* Previously, Bison sometimes generated parser tables with states that were
-  unreachable due to conflicts in predecessor states.  Bison now:
+* Previously, Bison sometimes generated parser tables containing unreachable
+  states.  A state can become unreachable during conflict resolution if Bison
+  disables a shift action leading to it from a predecessor state.  Bison now:

 
     1. Removes unreachable states.
 
 
     1. Removes unreachable states.
 


@@ -15,6 +16,13 @@ Changes in version 2.3a+ (????-??-??):
     3. For any rule used only in such states, Bison now reports the rule as
        "never reduced because of conflicts".
 
     3. For any rule used only in such states, Bison now reports the rule as
        "never reduced because of conflicts".
 

+  This feature can be disabled with the following directive:
+
+    %define lr.keep_unreachable_states
+
+  See the %define entry in the `Bison Declaration Summary' in the Bison manual
+  for further discussion.
+

 * When instructed to generate a `.output' file including lookahead sets
   (using `--report=lookahead', for example), Bison now prints each reduction's
   lookahead set only next to the associated state's one item that (1) is
 * When instructed to generate a `.output' file including lookahead sets
   (using `--report=lookahead', for example), Bison now prints each reduction's
   lookahead set only next to the associated state's one item that (1) is