Ludovic Langevine, SICS
Trace-based debugging in CP

Abstract:

Constraint debugging still lacks the suitable debugging tools and
technics. Numerous debugging tools have already been designed but
there is no "ultimate" one. Most of them collect data during the
execution and compute views that help programmer better understand the
behavior of  the execution. 
To ease the developement of new debugging tools, we propose to
implement them on top of a generic execution tracer. The trace we
propose is rich enough to cover the needs of a large variety of
tools. Moreover, the verbosity of the generated trace can be adapted
during the execution to fill the needs of a specific tool, thanks to a
so-called "tracer driver". The tracer driver limits the overhead of
the trace generation. Our trace schema have already been implemented
in four constraint solvers (GNU-Prolog, Choco, PaLM and CHIP) and
various debugging tools have been connected to all of them.