use instructiont::make_X in remove_virtual_functions

This prevents duplicate initialization of instructions.

Author: kroening

src/goto-programs/remove_virtual_functions.cpp

@@ -228,9 +228,8 @@ goto_programt::targett remove_virtual_functionst::remove_virtual_function(
   // match any expected type:
   if(fallback_action==virtual_dispatch_fallback_actiont::ASSUME_FALSE)
   {
-    auto newinst=new_code_calls.add_instruction(ASSUME);
-    newinst->guard=false_exprt();
-    newinst->source_location=vcall_source_loc;
+    new_code_calls.add(
+      goto_programt::make_assumption(false_exprt(), vcall_source_loc));
   }
 
   // get initial identifier for grouping
@@ -250,29 +249,34 @@ goto_programt::targett remove_virtual_functionst::remove_virtual_function(
     // Only create one call sequence per possible target:
     if(insertit.second)
     {
-      goto_programt::targett t1=new_code_calls.add_instruction();
-      t1->source_location=vcall_source_loc;
       if(fun.symbol_expr.has_value())
       {
-      // call function
-        t1->make_function_call(code);
+        // call function
+        goto_programt::targett t1 = new_code_calls.add(
+          goto_programt::make_function_call(code, vcall_source_loc));
+
         create_static_function_call(
           t1->get_function_call(), *fun.symbol_expr, ns);
+
+        insertit.first->second = t1;
       }
       else
       {
+        goto_programt::targett t1 = new_code_calls.add(
+          goto_programt::make_assertion(false_exprt(), vcall_source_loc));
+
         // No definition for this type; shouldn't be possible...
-        t1->make_assertion(false_exprt());
         t1->source_location.set_comment(
           "cannot find calls for " +
           id2string(code.function().get(ID_identifier)) + " dispatching " +
           id2string(fun.class_id));
+
+        insertit.first->second = t1;
       }
-      insertit.first->second=t1;
+
       // goto final
-      goto_programt::targett t3=new_code_calls.add_instruction();
-      t3->source_location=vcall_source_loc;
-      t3->make_goto(t_final, true_exprt());
+      new_code_calls.add(
+        goto_programt::make_goto(t_final, true_exprt(), vcall_source_loc));
     }
 
     // Fall through to the default callee if possible:
@@ -308,9 +312,8 @@ goto_programt::targett remove_virtual_functionst::remove_virtual_function(
       }
       else
       {
-        goto_programt::targett new_goto = new_code_gotos.add_instruction();
-        new_goto->source_location = vcall_source_loc;
-        new_goto->make_goto(insertit.first->second, class_id_test);
+        new_code_gotos.add(goto_programt::make_goto(
+          insertit.first->second, class_id_test, vcall_source_loc));
       }
     }
   }