A compiler generates code providing an execution sequence, from a declarative event-driven model, for execution by a computer. To assist in debugging the declarative event-driven model, the compiler also generates cross-references that relate steps in the generated code to elements of the declarative source code. The cross-references may be used as input to a debugger, along with the declarative source and the generated code, to assist a user who is stepping through the generated code (for example) in understanding which portion of the declarative source gave rise to the current step in the generated execution sequence.