Code Generation

We describe the use of the Cyber-Physical Modeling Language (CyPhyML) to support trade studies and integration activities in system-level vehicle designs. CyPhyML captures parameterized component behavior using acausal models (i.e. hybrid bond graphs and Modelica) to enable automatic composition and synthesis of simulation models for significant vehicle subsystems. Generated simulations allow us to compare performance between different design alternatives. System behavior and evaluation are specified independently from specifications for design-space alternatives. Test bench models in CyPhyML are given in terms of generic assemblies over the entire design space, so performance can be evaluated for any selected design instance once automated design space exploration is complete. Generated Simulink models are also integrated into a mobility model for interactive 3-D simulation.

A practical type system for ML-style recursive modules should address at least two technical challenges. First, it needs to solve the double vision problem, which refers to an inconsistency between external and internal views of recursive modules. Second, it needs to overcome the tension between practical decidability and expressivity which arises from the potential presence of cyclic type definitions caused by recursion between modules. Although type systems in previous proposals solve the double vision problem and are also decidable, they fail to typecheck common patterns of recursive modules, such as functor fixpoints, that are essential to the expressivity of the module system and the modular development of recursive modules. This paper proposes a novel type system for recursive modules that solves the double vision problem and typechecks common patterns of recursive modules including functor fixpoints. First, we design a type system with a type equivalence based on weak bisimil...

Deep Learning (DL) techniques for Natural Language Processing have been evolving remarkably fast. Recently, the DL advances in language modeling, machine translation, and paragraph understanding are so prominent that the potential of DL in Software Engineering cannot be overlooked, especially in the field of program learning. To facilitate further research and applications of DL in this field, we provide a comprehensive review to categorize and investigate existing DL methods for source code modeling and generation. To address the limitations of the traditional source code models, we formulate common program learning tasks under an encoder-decoder framework. After that, we introduce recent DL mechanisms suitable to solve such problems. Then, we present the state-of-the-art practices and discuss their challenges with some recommendations for practitioners and researchers as well.

En este trabajo se presentan las lineas del grupo de investigacion “Procesadores de Lenguajes” perteneciente al Departamento de Computacion de la UNRC. Los aspectos fundamentales son la creacion de modelos y herramientas de ultima generacion para la generacion de procesadores de lenguajes incluyendo la generacion de Codigo Movil Seguro. Se resenan los trabajos del ultimo ano que han permitido: construir un generador de analizadores lexicos traductores, construir un generador de evaluadores concurrentes sin comunicacion de gramaticas de atributos, realizar un analisis comparativo de los generadores de procesadores de lenguajes mas usados y de Japlage y definir un lenguaje assembler tipado para la ejecucion segura de codigo movil no confiable. Ademas, se presentan los trabajos iniciados por el grupo destacando la obtencion de un prototipo de un compilador certificante y entorno de ejecucion para Proof-Carrying Code (PCC) – una tecnica para garantizar codigo movil seguro – .

Code size is an important concern in embedded systems. VLIW architectures are popular for embedded systems, but often increase code size, by requiring NOPs to be inserted into the code to satisfy instruction placement constraints. Existing VLIW instruction schedulers target run-time but not code size. Indeed, current schedulers often increase code size, by generating compensation copies of instructions when moving them across basic block boundaries. Our approach, for the first time, uses the power of scheduling instructions ...

Abstract--- Security protocols are critical components for the construction of secure and dependable distributed applications, but their implementation is challenging and error prone. Therefore, tools for formal modelling and analysis of security protocols can be potentially very useful to support software engineers. However, despite such tools having been available for a long time, their adoption outside the research community has been very limited. In fact, most practitioners find such applications too complex and hardly usable for their daily work. In this paper, we present an Integrated Development Environment for the design, verification and implementation of security protocols, aimed at lowering the adoption barrier of formal methods tools for security. In the spirit of Model Driven Development, the environment supports the user in the specification of the model using the simple and intuitive language AnB (and its extension AnBx). Moreover, it provides a push-button solution f...

Model Driven Architecture adopts a visual approach to software development. The main development activities are the construction of visual (typically Unified Modelling Language (UML)) models and the transformation of source models into target models, including application code ...

Over the last years, two new software engineering approaches have been proposed: generative programming and aspect-oriented software development. Generative programming addresses the study and definition of methods and tools that enable the automatic production of system families from a high-level specification. Aspect-oriented software development has been proposed as a technique for improving separation of concerns in the construction of OO software and supporting improved reusability and ease of evolution. The use of aspect-oriented techniques in a definition of a generative approach can bring benefits to the modeling and generation of crosscutting features since early development stages. This paper presents our experience in the definition of an aspect-oriented generative approach. The proposed approach explores the multi-agent systems domain to enable the code generation of agent architectures.

In many areas of computation and reasoning, the value of an expression may depend on an implicit parameter, which may for example represent a program state, or time, or a possible world. In this paper we describe a formal first order logic which captures a general notion of expressions which depend on an implicit parameter. Both semantics and syntax are discussed. An important application of the logic, used as a running example, is to provide a basis for unifying the Hoare logic of procedural programs with the mathematically powerful techniques of classical logic and set theory. It is, however, beyond the scope of this paper to develop this application fully.

El papel de los modelos es fundamental en el desarrollo de software para potenciar el reuso de los diferentes elementos del software y facilitar la labor de los diferentes roles que participan del proceso. La Arquitectura Dirigida por Modelos (MDA) propone un proceso de desarrollo basado en la realizacion y transformacion de modelos. Los principios en los que se fundamenta MDA son la abstraccion, la automatizacion y la estandarizacion. El proceso central de MDA es la transformacion de modelos que parten del espacio del problema (CIM) hasta modelos especificos de la plataforma (PSM), pasando por modelos que describen una solucion independientemente de la computacion (PIM). Para explicar el papel de los modelos en el proceso de desarrollo de software este articulo explora los principales conceptos presentados en la propuesta de MDA. Abstract: The role of models is critical in software development to enable the reuse of different software elements and to aid the work of several roles i...

Interpreters are widely used to implement portable language runtime environments. Programs written in these languages may benefit from performance beyond that obtainable by optimizing interpretation alone. A modern high-performance mixed-mode virtual machine (VM) includes a method-based Just In Time (JIT) compiler. A method-based JIT, how- ever, requires the up-front development of a com- plex compilation infrastructure before any perfor- mance benefits are realized. Ideally, the architecture for a mixed-mode VM could detect and execute a variety of shapes of hot regions of a virtual program. Our VM architecture is based on context threading. It supports powerful, efficient instrumentation and a simple framework for dynamic code generation. It has the potential to directly support a full spectrum of mixed-mode ex- ecution: from interpreted bytecode bodies, to spe- cialized bytecode generated at runtime, to traces, to compiled methods. Further, it provides the neces- sary tools to de...