A case for explicit join point models for aspect-oriented intermediate languages

Aspect-oriented languages mostly employ implicit language-defined join point models, where well-defined points in the program are called join points and declarative predicates are used to quantify them. The primary motivation for using an implicit join point model is obliviousness and ease of quantification. A design choice for aspect-oriented intermediate languages is to mirror the source language model. In this position paper, I argue that an explicit join point model is better suited at the intermediate language level and sketch a preliminary solutio

Modular Compilation Strategies for Aspect-Oriented Constructs

In our previous work, we presented an aspect-oriented intermediate language, named Nu, to preserve design modularity in object code. Nu is based on two primitives: bind and remove. We showed that maintaining modularity in object code significantly improved the incremental compilation time of aspect-oriented programs. The key contribution of this work is a set of compilation strategies to Nu for a number of AspectJ constructs such as control flow (cflow and cflowbelow), instantiation (perthis, pertarget, percflow, percflowbelow) and dynamic checks (if, this, target, args), as well as composition operators (&& and ||). The motivation was to determine if these high-level language constructs need to be supported in the intermediate language. Our compilation strategies are modular and textually local. To compile a construct in a module, only the information about that module\u27s implementation and the specification of other modules referenced in that module are needed. The generated intermediate code for a construct in a source module is confined to a single module in the object code. We show that our compilation strategies improve incremental compilation time of aspect-oriented programs. We also analyze our intermediate language with respect to constructs that are not directly supported

Context-aware security: Linguistic mechanisms and static analysis

Adaptive systems improve their efficiency by modifying their behaviour to respond to changes in their operational environment. Also, security must adapt to these changes and policy enforcement becomes dependent on the dynamic contexts. We study these issues within MLCoDa, (the core of) an adaptive declarative language proposed recently. A main characteristic of MLCoDa is to have two components: a logical one for handling the context and a functional one for computing. We extend this language with security policies that are expressed in logical terms. They are of two different kinds: context and application policies. The first, unknown a priori to an application, protect the context from unwanted changes. The others protect the applications from malicious actions of the context, can be nested and can be activated and deactivated according to their scope. An execution step can only occur if all the policies in force hold, under the control of an execution monitor. Beneficial to this is a type and effect system, which safely approximates the behaviour of an application, and a further static analysis, based on the computed effect. The last analysis can only be carried on at load time, when the execution context is known, and it enables us to efficiently enforce the security policies on the code execution, by instrumenting applications. The monitor is thus implemented within MLCoDa, and it is only activated on those policies that may be infringed, and switched off otherwise

A Type-theoretic Interpretation of Pointcuts and Advice

This article defines the semantics of MinAML, an idealized aspectoriented programming language, by giving a type-directed translation from a user-friendly external language to a compact, well-defined core language. We argue that our framework is an e#ective way to give semantics to aspect-oriented programming languages in general because the translation eliminates shallow syntactic di#erences between related constructs and permits definition of an elegant and extensible core language