Don't let -Wnone disable -Werror.

Discussed at
<http://lists.gnu.org/archive/html/bison-patches/2010-08/msg00009.html>.
* NEWS (2.5): Document.
* src/getargs.c (flags_argmatch): Accept a new argument that
specifies what flags "all" and thus "none" affect.
(FLAGS_ARGMATCH): Update flags_argmatch invocation.
* tests/input.at (-Werror is not affected by -Wnone and -Wall):
New test group.
(cherry picked from commit dab9663283437092d17af8ede75f3aff33380d53)

4 files changed, 72 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index bd642258..8feb6a55 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
 2011-03-27  Joel E. Denny  <joeldenny@joeldenny.org>
 
+	Don't let -Wnone disable -Werror.
+	Discussed at
+	<http://lists.gnu.org/archive/html/bison-patches/2010-08/msg00009.html>.
+	* NEWS (2.5): Document.
+	* src/getargs.c (flags_argmatch): Accept a new argument that
+	specifies what flags "all" and thus "none" affect.
+	(FLAGS_ARGMATCH): Update flags_argmatch invocation.
+	* tests/input.at (-Werror is not affected by -Wnone and -Wall):
+	New test group.
+
+2011-03-27  Joel E. Denny  <joeldenny@joeldenny.org>
+
 	* NEWS (2.5): Document fix for -Wno-CATEGORY.
 
 2011-03-20  Joel E. Denny  <joeldenny@joeldenny.org>
diff --git a/NEWS b/NEWS
index 64a25704..404efd7a 100644
--- a/NEWS
+++ b/NEWS
@@ -368,6 +368,13 @@ Bison News
 
     bison -Wall,no-yacc gram.y
 
+*** 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
+
 * Changes in version 2.4.3 (2010-08-05):
 
 ** Bison now obeys -Werror and --warnings=error for warnings about
diff --git a/src/getargs.c b/src/getargs.c
index 35b6a2a6..a15dd24c 100644
--- a/src/getargs.c
+++ b/src/getargs.c
@@ -82,18 +82,19 @@ char *program_name;
  *  \param option   option being decoded.
  *  \param keys     array of valid subarguments.
  *  \param values   array of corresponding (int) values.
+ *  \param all      the all value.
  *  \param flags    the flags to update
  *  \param args     comma separated list of effective subarguments to decode.
  *                  If 0, then activate all the flags.
  *
  *  If VALUE != 0 then KEY sets flags and no-KEY clears them.
- *  If VALUE == 0 then KEY clears all flags and no-KEY sets all flags.
- *  Thus no-none = all and no-all = none.
+ *  If VALUE == 0 then KEY clears all flags from \c all and no-KEY sets all
+ *  flags from \c all.  Thus no-none = all and no-all = none.
  */
 static void
 flags_argmatch (const char *option,
 		const char * const keys[], const int values[],
-		int *flags, char *args)
+		int all, int *flags, char *args)
 {
   if (args)
     {
@@ -103,20 +104,24 @@ flags_argmatch (const char *option,
 	  int no = strncmp (args, "no-", 3) == 0 ? 3 : 0;
 	  int value = XARGMATCH (option, args + no, keys, values);
 	  if (value == 0)
-	    if (no)
-	      *flags = ~0;
-	    else
-	      *flags = 0;
+	    {
+	      if (no)
+		*flags |= all;
+	      else
+		*flags &= ~all;
+	    }
 	  else
-	    if (no)
-	      *flags &= ~value;
-	    else
-	      *flags |= value;
+	    {
+	      if (no)
+		*flags &= ~value;
+	      else
+		*flags |= value;
+	    }
 	  args = strtok (NULL, ",");
 	}
     }
   else
-    *flags = ~0;
+    *flags |= all;
 }
 
 /** Decode a set of sub arguments.
@@ -126,11 +131,12 @@ flags_argmatch (const char *option,
  *
  *  \arg FlagName_args   the list of keys.
  *  \arg FlagName_types  the list of values.
+ *  \arg FlagName_all    the all value.
  *  \arg FlagName_flag   the flag to update.
  */
 #define FLAGS_ARGMATCH(FlagName, Args)					\
   flags_argmatch ("--" #FlagName, FlagName ## _args, FlagName ## _types, \
-		  &FlagName ## _flag, Args)
+		  FlagName ## _all, &FlagName ## _flag, Args)
 
 
 /*----------------------.
@@ -576,10 +582,7 @@ getargs (int argc, char *argv[])
 	exit (EXIT_SUCCESS);
 
       case 'W':
-	if (optarg)
-	  FLAGS_ARGMATCH (warnings, optarg);
-	else
-	  warnings_flag |= warnings_all;
+	FLAGS_ARGMATCH (warnings, optarg);
 	break;
 
       case 'b':
diff --git a/tests/input.at b/tests/input.at
index ada68261..8d1e80d1 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -1314,3 +1314,36 @@ AT_BISON_CHECK([[-Dparse.lac.memory-trace=full input.y]],
 ]])
 
 AT_CLEANUP
+
+## --------------------------------------------- ##
+## -Werror is not affected by -Wnone and -Wall.  ##
+## --------------------------------------------- ##
+
+AT_SETUP([[-Werror is not affected by -Wnone and -Wall]])
+
+AT_DATA([[input.y]],
+[[%%
+foo-bar: ;
+]])
+
+# -Werror is not enabled by -Wall or equivalent.
+AT_BISON_CHECK([[-Wall input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+AT_BISON_CHECK([[-W input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+AT_BISON_CHECK([[-Wno-none input.y]], [[0]], [[]],
+[[input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+
+# -Werror is not disabled by -Wnone or equivalent.
+AT_BISON_CHECK([[-Werror,none,yacc input.y]], [[1]], [[]], [[stderr]])
+AT_CHECK([[sed 's/^.*bison:/bison:/' stderr]], [[0]],
+[[bison: warnings being treated as errors
+input.y:2.1-7: warning: POSIX Yacc forbids dashes in symbol names: foo-bar
+]])
+[mv stderr experr]
+AT_BISON_CHECK([[-Werror,no-all,yacc input.y]], [[1]], [[]], [[experr]])
+
+AT_CLEANUP