PublicShow sourcetest_cover.pl -- Clause cover analysis

The purpose of this module is to find which part of the program has been used by a certain goal. Usage is defined in terms of clauses that have fired, seperated in clauses that succeeded at least once and clauses that failed on each occasion.

This module relies on the SWI-Prolog tracer hooks. It modifies these hooks and collects the results, after which it restores the debugging environment. This has some limitations:

The result is represented as a list of clause-references. As the references to clauses of dynamic predicates cannot be guaranteed, these are omitted from the result.

bug
- Relies heavily on SWI-Prolog internals. We have considered using a meta-interpreter for this purpose, but it is nearly impossible to do 100% complete meta-interpretation of Prolog. Example problem areas include handling cuts in control-structures and calls from non-interpreted meta-predicates.
To be done
- Provide detailed information organised by predicate. Possibly annotate the source with coverage information.
Source show_coverage(:Goal) is semidet
Source show_coverage(:Goal, +Modules:list(atom)) is semidet
Report on coverage by Goal. Goal is executed as in once/1. Report the details of the uncovered clauses for each module in the list Modules