grammar: warn about unused precedence for symbols

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index 5b6ea0c5daa3344c97319b5d24c0f36b0eb035cf..62f834b6390960c110c4d0d3804a075c834a97fa 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -198,6 +198,13 @@ GNU Bison NEWS
     bar.y: error: shift/reduce conflicts: 1 found, 0 expected
     bar.y: error: reduce/reduce conflicts: 2 found, 0 expected
 
     bar.y: error: shift/reduce conflicts: 1 found, 0 expected
     bar.y: error: reduce/reduce conflicts: 2 found, 0 expected
 

+*** Useless precedence
+
+  Bison now warns about symbols with a declared precedence but no declared
+  associativity (i.e. declared with %precedence), and whose precedence is
+  never used.  In that case, the symbol can be safely declared with %token
+  instead, without modifying the parsing tables.
+

 ** Additional yylex/yyparse arguments
 
   The new directive %param declares additional arguments to both yylex and
 ** Additional yylex/yyparse arguments
 
   The new directive %param declares additional arguments to both yylex and