Add support for Bison's "%expect <int>" directive.

I originally coded this myself, and now I realize {Net,Open}BSD had already
coded this.  I have tossed my version to reduce diffs between the projects.

Obtained from:	OpenBSD 2.5

usr.bin/yacc/defs.h

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)defs.h	5.6 (Berkeley) 5/24/93
- *	$Id: defs.h,v 1.5 1997/02/22 19:57:58 peter Exp $
+ *	$Id: defs.h,v 1.6 1997/08/28 06:33:52 charnier Exp $
  */
 
 #include <sys/cdefs.h>	/* for __P macro */
@@ -104,6 +104,7 @@
 #define START 7
 #define UNION 8
 #define IDENT 9
+#define EXPECT 10
 
 
 /*  symbol classes  */
@@ -300,6 +301,7 @@ extern short *from_state;
 extern short *to_state;
 
 extern action **parser;
+extern int SRexpect;
 extern int SRtotal;
 extern int RRtotal;
 extern short *SRconflicts;

usr.bin/yacc/mkpar.c

@@ -39,13 +39,14 @@
 static char const sccsid[] = "@(#)mkpar.c	5.3 (Berkeley) 1/20/91";
 #endif
 static const char rcsid[] =
-	"$Id: mkpar.c,v 1.7 1997/08/28 06:33:53 charnier Exp $";
+	"$Id: mkpar.c,v 1.8 1999/07/04 17:26:16 billf Exp $";
 #endif /* not lint */
 
 #include <stdlib.h>
 #include "defs.h"
 
 action **parser;
+int SRexpect;
 int SRtotal;
 int RRtotal;
 short *SRconflicts;
@@ -332,11 +333,15 @@ remove_conflicts()
 
 static void
 total_conflicts()
+{
+    /* Warn if s/r != expect or if any r/r */
+    if ((SRtotal != SRexpect) || RRtotal)
     {
 	    if (SRtotal == 1)
 	    warnx("1 shift/reduce conflict");
 	    else if (SRtotal > 1)
 	    warnx("%d shift/reduce conflicts", SRtotal);
+    }
 
     if (RRtotal == 1)
 	warnx("1 reduce/reduce conflict");

usr.bin/yacc/reader.c

@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id$
+ *	$Id: reader.c,v 1.6 1997/02/22 19:58:01 peter Exp $
  */
 
 #ifndef lint
@@ -329,6 +329,8 @@ keyword()
 	    return (UNION);
 	if (strcmp(cache, "ident") == 0)
 	    return (IDENT);
+	if (strcmp(cache, "expect") == 0)
+	    return (EXPECT);
     }
     else
     {
@@ -974,6 +976,51 @@ int assoc;
 }
 
 
+/*
+ * %expect requires special handling
+ * as it really isn't part of the yacc
+ * grammar only a flag for yacc proper.
+ */
+static void
+declare_expect(assoc)
+int assoc;
+{
+    register int c;
+
+    if (assoc != EXPECT) ++prec;
+
+    /*
+     * Stay away from nextc - doesn't
+     * detect EOL and will read to EOF.
+     */
+    c = *++cptr;
+    if (c == EOF) unexpected_EOF();
+
+    for(;;)
+    {
+	if (isdigit(c))
+	{
+	    SRexpect = get_number();
+	    break;
+	}
+	/*
+	 * Looking for number before EOL.
+	 * Spaces, tabs, and numbers are ok,
+	 * words, punc., etc. are syntax errors.
+	 */
+	else if (c == '\n' || isalpha(c) || !isspace(c))
+	{
+	    syntax_error(lineno, line, cptr);
+	}
+	else
+	{
+	    c = *++cptr;
+	    if (c == EOF) unexpected_EOF();
+	}
+    }
+}
+
+
 static void
 declare_types()
 {
@@ -1060,6 +1107,10 @@ read_declarations()
 	    declare_tokens(k);
 	    break;
 
+	case EXPECT:
+	    declare_expect(k);
+	    break;
+
 	case TYPE:
 	    declare_types();
 	    break;