2 files changed, 14 insertions, 4 deletions

diff --git a/src/vppinfra/macros.c b/src/vppinfra/macros.c
index bc6df55b39d..240cef02e0e 100644
--- a/src/vppinfra/macros.c
+++ b/src/vppinfra/macros.c
@@ -92,12 +92,20 @@ clib_macro_get_value (clib_macro_main_t * mm, char *name)
  * looks up $foobar in the variable table.
  */
 i8 *
-clib_macro_eval (clib_macro_main_t * mm, i8 * s, i32 complain)
+clib_macro_eval (clib_macro_main_t * mm, i8 * s, i32 complain, u16 level,
+		 u16 max_level)
 {
   i8 *rv = 0;
   i8 *varname, *varvalue;
   i8 *ts;
 
+  if (level >= max_level)
+    {
+      if (complain)
+	clib_warning ("circular definition, level %d", level);
+      return (i8 *) format (0, " CIRCULAR ");
+    }
+
   while (*s)
     {
       switch (*s)
@@ -161,7 +169,8 @@ clib_macro_eval (clib_macro_main_t * mm, i8 * s, i32 complain)
 	  if (varvalue)
 	    {
 	      /* recursively evaluate */
-	      ts = clib_macro_eval (mm, varvalue, complain);
+	      ts = clib_macro_eval (mm, varvalue, complain, level + 1,
+				    max_level);
 	      vec_free (varvalue);
 	      /* add results to answer */
 	      vec_append (rv, ts);
@@ -195,7 +204,7 @@ clib_macro_eval_dollar (clib_macro_main_t * mm, i8 * s, i32 complain)
   i8 *rv;
 
   s2 = (i8 *) format (0, "$(%s)%c", s, 0);
-  rv = clib_macro_eval (mm, s2, complain);
+  rv = clib_macro_eval (mm, s2, complain, 0 /* level */ , 8 /* max_level */ );
   vec_free (s2);
   return (rv);
 }
diff --git a/src/vppinfra/macros.h b/src/vppinfra/macros.h
index 54ceda7016b..1b2064add34 100644
--- a/src/vppinfra/macros.h
+++ b/src/vppinfra/macros.h
@@ -39,7 +39,8 @@ int clib_macro_set_value (clib_macro_main_t * mm, char *name, char *value);
 void clib_macro_add_builtin (clib_macro_main_t * mm, char *name,
 			     void *eval_fn);
 i8 *clib_macro_get_value (clib_macro_main_t * mm, char *name);
-i8 *clib_macro_eval (clib_macro_main_t * mm, i8 * s, i32 complain);
+i8 *clib_macro_eval (clib_macro_main_t * mm, i8 * s, i32 complain,
+		     u16 level, u16 max_level);
 i8 *clib_macro_eval_dollar (clib_macro_main_t * mm, i8 * s, i32 complain);
 void clib_macro_init (clib_macro_main_t * mm);
 void clib_macro_free (clib_macro_main_t * mm);