Careful Analysis of Type Spoofing

Saraswat’s type spoofing was one of the most long-lasting bugs in the JVM. Recently, its solution was proposed and implemented in JDK 1.2. The correctness of this new feature, however, is non-trivial and required the formal soundness proof. Actually, during our work on it, two flaws inside the new JVM implementation were found. This paper briefly reports our work and results.