Inserting a call statement

[drizzle drizzle]

Hi 
    I am trying to insert a function call "foo" inside the tree list. 
        

Inside this particular loop 
         for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
         {

 //            if a particular condition is satisfied  I do the following 

                tree id = get_identifier ("foo");
                tree t = build_function_type_list (void_type_node,NULL_TREE);
                tree decl = build_decl (FUNCTION_DECL, id, t);
                tree call = build_function_call_expr (decl, NULL);
                 bsi_insert_before(&bsi,call,BSI_CHAIN_END); // I have tried 
BSI_NEW_STMT


          }


Although the node is created properly, an assertion in
tree-flow-inline.h fails. Can someone help me identify the issue here.
 i will appreciate that

thanks