Add -Wconflicts-sr and -Wconflicts-rr.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index ed2b23f9dd4905577b5e3770c382a7841a5eb5a7..d22e246adfdf02df7dc53d8519cd73d177c8ad89 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -359,6 +359,49 @@ Bison News
 
 *** Parser traces now print the top element of the stack.
 
+** -W/--warnings fixes:
+
+*** Bison now properly recognizes the "no-" versions of categories:
+
+  For example, given the following command line, Bison now enables all
+  warnings except warnings for incompatibilities with POSIX Yacc:
+
+    bison -Wall,no-yacc gram.y
+
+*** Bison now treats S/R and R/R conflicts like other warnings:
+
+  Previously, conflict reports were independent of Bison's normal
+  warning system.  Now, Bison recognizes the warning categories
+  "conflicts-sr" and "conflicts-rr".  This change has important
+  consequences for the -W and --warnings command-line options.  For
+  example:
+
+    bison -Wno-conflicts-sr gram.y  # S/R conflicts not reported
+    bison -Wno-conflicts-rr gram.y  # R/R conflicts not reported
+    bison -Wnone            gram.y  # no conflicts are reported
+    bison -Werror           gram.y  # any conflict is an error
+
+  However, as before, if the %expect or %expect-rr directive is
+  specified, an unexpected number of conflicts is an error, and an
+  expected number of conflicts is not reported, so -W and --warning
+  then have no effect on the conflict report.
+
+*** The "none" category no longer disables a preceding "error":
+
+  For example, for the following command line, Bison now reports
+  errors instead of warnings for incompatibilities with POSIX Yacc:
+
+    bison -Werror,none,yacc gram.y
+
+*** The "none" category now disables all Bison warnings.
+
+  Previously, the "none" category disabled only Bison warnings for
+  which there existed a specific -W/--warning category.  However,
+  given the following command line, Bison is now guaranteed to
+  suppress all warnings:
+
+    bison -Wnone gram.y
+
 * Changes in version 2.4.3 (2010-08-05):
 
 ** Bison now obeys -Werror and --warnings=error for warnings about