Abstract. The system dependence graph (SDG) is a data structure used in the imperative paradigm for different static analysis, and particularly, for program slicing. Program slicing allows us to determine the part of a program (called slice) that influences a given variable of interest. Thanks to the SDG, we can produce precise slices for interprocedural programs. Unfortunately, the SDG cannot be used in the functional paradigm due to important features that are not considered in this formalism (e.g., pattern matching, higher-order, composite expressions, etc.). In this work we propose the first adaptation of the SDG to a functional language facing these problems. We take Erlang as the host language and we adapt the algorithms used to slice the SDG to produce precise slices of Erlang interprocedural programs. As a proof-of-concept, we have implemented a program slicer for Erlang based on our SDGs.

Declarative debuggers are semi-automatic debugging tools that abstract the execution details to focus on the program semantics. This paper presents a tool implementing this approach for the sequential subset of Erlang, a functional language with dynamic typing and strict evaluation. Given an erroneous computation, it first detects an erroneous function (either a "named" function or a lambda-abstraction), and then continues the process to identify the fragment of the function responsible for the error. Among its features it includes support for exceptions, predefined and built-in functions, higher-order functions, and trusting and undo commands.

Petri nets provide a means for modelling and verifying the behavior of concurrent systems. Program slicing is a well-known technique in imperative programming for extracting those statements of a program that may affect a given program point. In the context of Petri nets, computing a net slice can be seen as a graph reachability problem. In this paper, we propose two slicing techniques for Petri nets that can be useful to reduce the size of the considered net, thereby simplifying subsequent analysis and debugging tasks by standard Petri net techniques.

No abstract

In any alive and nontrivial program, the source code naturally evolves along the lifecycle for many reasons such as the implementation of new functionality, the optimization of a bottleneck, or the refactoring of an obscure function. Frequently, these code changes affect various different functions and modules, so it can be difficult to know whether the correct behaviour of the previous version has been preserved in the new version. In this paper, we face this problem in the context of the Erlang language, where most developers rely on a previously defined test suite to check the behaviour preservation. We propose an alternative approach to automatically obtain a test suite that specifically focusses on comparing the old and new versions of the code. Our test case generation is directed by a sophisticated combination of several already existing tools such as TypEr, CutEr, and PropEr; and it introduces novel ideas such as allowing the programmer to choose one or more expressions of interest that must preserve the behaviour, or the recording of the sequences of values to which those expressions are evaluated. All the presented work has been implemented in an open-source tool that is publicly available on GitHub.