Termination analysis of programs with complex control-flow

Tesis de la Universidad Complutense de Madrid, Facultad de Informática, leída el 22-01-2021El problema de la terminación de un programa es fundamental en la informática y ha sido objeto de estudio de numerosas investigaciones. La técnica mejor conocida, y más frecuentemente utilizada, para demostrar terminación es la del uso de funciones de clasificación (ranking functions). Estas funciones relacionan los estados del programa con los elementos de un conjunto ordenado bien-fundado, tal que el valor desciende en estado consecutivos del programa. Como descender en un conjunto ordenado bien-fundado no se puede hacer de manera infinita se demuestra la terminación del programa. Es esta tesis, abordamos el problema de terminación para Sistemas de Transiciones (Transition Systems) con valores numéricos, que son una representación de programas muy comúnmente utilizada en los análisis de programas. Los Sistemas de Transiciones están definidos por Grafos de Control de Flujo (Control-Flow Graph) donde las aristas están anotadas con fórmulas describiendo las transiciones que hay entre los nodos correspondientes...The problem of the program termination is fundamental in Computer Science and has been the subject of voluminous research. The best known, and often used technique for proving termination is that of ranking functions. These are functions that map the program states to the elements of a well-founded ordered set, such that the value descends on consecutive program states. Since descent in a well-founded set cannot be infinite, this proves terminatio. In this thesis, we address the termination problem for Transition Systems with numerical variables, which is a very common program representation that is often used in program analysis. They are defined by Control-Flow Graphs where edges are annotated with formulas describing transitions between corresponding nodes...Fac. de InformáticaTRUEunpu

EasyInterface: a toolkit for the rapid development of GUIs for research prototype tools

During the lifetime of a research project, different partners develop several research prototype tools that share many common aspects. This is equally true for researchers as individuals and as groups: during a period of time they often develop several related tools to pursue a specific research line. Making research prototype tools easily accessible to the community is of utmost importance to promote the corresponding research, get feedback, and increase the tools’ lifetime beyond the duration of a specific project. One way to achieve this is to build graphical user interfaces (GUIs) that facilitate trying tools; in particular, with web-interfaces one avoids the overhead of downloading and installing the tools. Building GUIs from scratch is a tedious task, in particular for web-interfaces, and thus it typically gets low priority when developing a research prototype. Often we opt for copying the GUI of one tool and modifying it to fit the needs of a new related tool. Apart from code duplication, these tools will “live” separately, even though we might benefit from having them all in a common environment since they are related. This work aims at simplifying the process of building GUIs for research prototypes tools. In particular, we present EasyInterface, a toolkit that is based on novel methodology that provides an easy way to make research prototype tools available via common different environments such as a web-interface, within Eclipse, etc. It includes a novel text-based output language that allows to present results graphically without requiring any knowledge in GUI/Web programming. For example, an output of a tool could be (a structured version of) “highlight line number 10 of file ex.c” and “when the user clicks on line 10, open a dialog box with the text ...”. The environment will interpret this output and converts it to corresponding visual e_ects. The advantage of using this approach is that it will be interpreted equally by all environments of EasyInterface, e.g., the web-interface, the Eclipse plugin, etc. EasyInterface has been developed in the context of the Envisage [5] project, and has been evaluated on tools developed in this project, which include static analyzers, test-case generators, compilers, simulators, etc. EasyInterface is open source and available at GitHub2

Añadiendo mecanismos de ayuda en un juez on-line automático para soporte a mentorías académicas

Todos los jueces en línea, incluído en sus inicios ¡Acepta el reto! (https://www.aceptaelreto.com) desarrollado por profesores de la UCM, adolecen de un problema de realimentación al usuario: cuando el visitante hace un envío incorrecto el sistema no es capaz de dar información específica del error. El documento es la memoria final de un Proyecto de Innovación y Mejora de la Calidad Docente (PIMCD) de 2017/2018 en el que se puso en marcha un sistema de pistas en el juez