Typed intermediate language support for languages with multiple inheritance

摘要

A typed intermediate representation of source code written in a language that supports multiple inheritance is presented. The typed intermediate representation uses paths to represent objects embedded in other objects. For each class, an exact record type represents layout of complete objects of that class. An approximated record type describes layout of inner objects when the runtime types of the objects are statically unknown. Address arithmetic is represented by special instructions and type-checked to ensure proper pointer adjustment. Types are also given to “this” pointers of methods within classes. These “this” pointer types refer to the paths associated with the object.