Causal-Consistent Reversible Debugging: Improving CauDEr

TL;DR

This paper extends a causal-consistent reversible debugging framework for Erlang, integrating source-level support and combining user-driven and replay debugging approaches into an improved tool with a new interface.

Contribution

It introduces source-level support for Erlang in the reversible debugger and unifies two debugging approaches into a comprehensive framework and tool.

Findings

Extended debugger to handle source Erlang programs.

Unified user-driven and replay debugging approaches.

Developed an improved debugging tool with a new interface.

Abstract

Causal-consistent reversible debugging allows one to explore concurrent computations back and forth in order to locate the source of an error. In this setting, backward steps can be chosen freely as long as they are "causal consistent", i.e., as long as all the actions that depend on the action we want to undo have been already undone. Here, we consider a framework for causal-consistent reversible debugging in the functional and concurrent language Erlang. This framework considered programs translated to an intermediate representation, called Core Erlang. Although using such an intermediate representation simplified both the formal definitions and their implementation in a debugging tool, the choice of Core Erlang also complicated the use of the debugger. In this paper, we extend the framework in order to deal with source Erlang programs, also including some features that were not considered before. Moreover, we integrate the two existing approaches (user-driven debugging and replay debugging) into a single, more general framework, and develop a new version of the debugging tool CauDEr including all the mentioned extensions as well as a renovated user interface.