Multi-Mode Debugging for FRP-Based Embedded Systems

Abstract

Emfrp is a functional reactive programming (FRP) language designed for small-scale embedded systems. Time-varying values are the primary abstraction mechanism in FRP and enable concise descriptions of reactive behavior. In practice, however, Emfrp programs are compiled into C and combined with platform-dependent input/output components written in C or C++. Consequently, developers must debug the resulting mixed C/C++ program using conventional debuggers such as GDB, even though the application logic is written in Emfrp. This situation creates an abstraction gap between the source-level FRP program and the executable system. This paper presents a multi-mode debugging framework for Emfrp-based embedded applications. The framework supports debugging at the level of Emfrp abstractions while also allowing inspection of platform-specific C/C++ I/O code. Our approach uses a source code mapping technique that relates Emfrp constructs to corresponding locations in the compiled program. A case study on an ESP32 microcontroller using representative debugging scenarios demonstrates improved debugging efficiency.

This paper was accepted and presented at the 4th ACM International Workshop on Future Debugging Techniques (DEBT '26) held in Brussels on June 29, 2026. The official publication is scheduled to appear in the ACM Digital Library