The implementation of ada 2005 interface types in the GNAT compiler

One of the most important object-oriented features of the new revision of the Ada Programming Language is the introduction of Abstract Interfaces to provide a form of multiple inheritance. Ada 2005 Abstract Interface Types are based on Java interfaces, and as such support inheritance of operation specifications, rather than the general complexity of inheritance of implementations as in full multiple inheritance. Real-time uses of Ada demand efficient and bounded worst-case execution time for interface calls. In addition, modern systems require mixed-language programming. This paper summarizes part of the work done by the GNAT Development Team to provide an efficient implementation of this language feature and simplifies interfacing with C++.