4210 unsigned unsigned short short is valid in dtrace
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Eric Diven <eric.diven@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>

@@ -19,11 +19,11 @@
  * CDDL HEADER END
  */
 
 /*
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 #include <strings.h>
 #include <stdlib.h>
 #include <limits.h>

@@ -264,10 +264,30 @@
                 ddp = dt_decl_push(dt_decl_alloc(CTF_K_UNKNOWN, NULL));
                 ddp->dd_attr = attr;
                 return (ddp);
         }
 
+        if ((attr & DT_DA_LONG) && (ddp->dd_attr & DT_DA_LONGLONG)) {
+                xyerror(D_DECL_COMBO, "the attribute 'long' may only "
+                    "be used at most twice in a declaration");
+        }
+
+        if ((attr & DT_DA_SHORT) && (ddp->dd_attr & DT_DA_SHORT)) {
+                xyerror(D_DECL_COMBO, "the attribute 'short' may only be "
+                    "used at most once in a declaration");
+        }
+
+        if ((attr & DT_DA_SIGNED) && (ddp->dd_attr & DT_DA_SIGNED)) {
+                xyerror(D_DECL_COMBO, "the attribute 'signed' may only be "
+                    "used at most once in a declaration");
+        }
+
+        if ((attr & DT_DA_UNSIGNED) && (ddp->dd_attr & DT_DA_UNSIGNED)) {
+                xyerror(D_DECL_COMBO, "the attribute 'unsigned' may only be "
+                    "used at most once in a declaration");
+        }
+
         if (attr == DT_DA_LONG && (ddp->dd_attr & DT_DA_LONG)) {
                 ddp->dd_attr &= ~DT_DA_LONG;
                 attr = DT_DA_LONGLONG;
         }