Management of changes involving base classes is facilitated. An intermediate language code has execution-ready register allocation but unbound object field layout and/or virtual method slot assignment, thereby providing resilience. A symbolic reference rather than a direct offset can identify a field, and intermediate language code can be field order independent. Other symbolic references may also be used. Intermediate language code pseudo instructions can express items such as a field access, a method call, a virtual method call, part or all of a method prolog, part or all of a method epilog. A binder binds the intermediate language code to produce executable code. Thus, one may avoid recompilation otherwise required when a base class is revised by adding a field, removing a private field, rearranging field order, adding a virtual method, or rearranging virtual method order.