Fine-grained annotations for pointcuts with a finer granularity

A number of authors have suggested that AspectJ-like pointcut languages are too limited, and that they cannot select every possible join point in a program. Many enhanced pointcut languages have been proposed; they require virtually no change to the original code, but their improved expressive power comes often at the cost of making the pointcut expression too tightly connected with the structure of the programs that are being advised. Other solutions consist in simple extensions to the base language; they require only small changes to the original code, but they frequently serve no other immediate purpose than exposing pieces of code to the weaver. Annotations are a form of metadata that has been introduced in Java 5. Annotations have a number of uses: they may provide hints to the compiler, information to code processing tools and they can be retained at runtime. At the moment of writing, runtime-accessible annotations in the Java programming language can only be applied to classes, fields and methods. The support to annotate expressions and blocks feels like a natural extension to Java's annotation model, that can be also exploited to expose join points at a finer-grained level. In this paper we present an extension to the AspectJ language to select block and expression annotations in the @Java language extension.