There is an application in SWI's plunit that does coverage analysis which is extremely useful to see if any code has been missed by unit testing. For details see http://www.swi-prolog.org/pldoc/doc_for ... l%27%29%29
It is a small prolog application (250 lines) that uses only the debugger and the ordered set library. Could you give me an indication of how easy it would be to port? In particular the interaction with the debugger seems challenging.
It could make a nice addition to Logtalk.
PS I have attached the code. Perhaps not: .pl and even .txt extensions are not allowed for attachments. Inlined the code instead.
Code: Select all
/* $Id$ Part of SWI-Prolog Author: Jan Wielemaker E-mail: firstname.lastname@example.org WWW: http://www.swi-prolog.org Copyright (C): 1985-2006, University of Amsterdam This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(prolog_cover, [ show_coverage/1, % :Goal covered_clauses/4 % +Goal, -Result, -Succeeded, -Failed ]). :- use_module(library(ordsets)). :- set_prolog_flag(generate_debug_info, false). /** <module> Clause cover analysis The purpose of this module is to find which part of the program has been use 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 performance degrades significantly (about 10 times) * It is not possible to use the debugger using coverage analysis * The cover analysis tool is currently not thread-safe. 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. */ :- dynamic entered/1, % clauses entered exited/1. % clauses completed :- module_transparent covering/1, covering/4. %% show_coverage(Goal) % % Report on coverage by Goal show_coverage(Goal) :- covered_clauses(Goal, Result, Succeeded, Failed), file_coverage(Succeeded, Failed), return(Result). return(true). return(fail) :- !, fail. return(error(E)) :- throw(E). %% covered_clauses(:Goal, -Result, -Succeeded, -Failed) is det. % % Run Goal as once/1. Unify Result with one of =true=, =fail= or % error(Error). % % @param Succeeded Ordered set of succeeded clauses % @param Failed Ordered set of clauses that are entered but % never succeeded. covered_clauses(Goal, Result, Succeeded, Failed) :- asserta(user:prolog_trace_interception(Port, Frame, _, continue) :- prolog_cover:assert_cover(Port, Frame), Ref), port_mask([unify,exit], Mask), '$visible'(V, Mask), '$leash'(L, Mask), trace, call_with_result(Goal, Result), set_prolog_flag(debug, false), covered(Ref, V, L, Succeeded, Failed). %% call_with_result(:Goal, -Result) is det. % % Run Goal as once/1. Unify Result with one of =true=, =fail= or % error(Error). call_with_result(Goal, Result) :- ( catch(Goal, E, true) -> ( var(E) -> Result = true ; Result = error(E) ) ; Result = false ). port_mask(, 0). port_mask([H|T], Mask) :- port_mask(T, M0), '$syspreds':'$port_bit'(H, Bit), % Private stuff Mask is M0 \/ Bit. %% assert_cover(+Port, +Frame) is det. % % Assert coverage of the current clause. We monitor two ports: the % _unify_ port to see which clauses we entered, and the _exit_ % port to see which completed successfully. assert_cover(unify, Frame) :- running_static_pred(Frame), prolog_frame_attribute(Frame, clause, Cl), !, assert_entered(Cl). assert_cover(exit, Frame) :- running_static_pred(Frame), prolog_frame_attribute(Frame, clause, Cl), !, assert_exited(Cl). assert_cover(_, _). %% running_static_pred(+Frame) is semidet. % % True if Frame is not running a dynamic predicate. running_static_pred(Frame) :- prolog_frame_attribute(Frame, goal, Goal), \+ predicate_property(Goal, dynamic). %% assert_entered(+Ref) is det. %% assert_exited(+Ref) is det. % % Add Ref to the set of entered or exited clauses. assert_entered(Cl) :- entered(Cl), !. assert_entered(Cl) :- assert(entered(Cl)). assert_exited(Cl) :- exited(Cl), !. assert_exited(Cl) :- assert(exited(Cl)). %% covered(+Ref, +VisibleMask, +LeashMask, -Succeeded, -Failed) is det. % % Restore state and collect failed and succeeded clauses. covered(Ref, V, L, Succeeded, Failed) :- '$visible'(_, V), '$leash'(_, L), erase(Ref), findall(Cl, (entered(Cl), \+exited(Cl)), Failed0), findall(Cl, retract(exited(Cl)), Succeeded0), retractall(entered(Cl)), sort(Failed0, Failed), sort(Succeeded0, Succeeded). /******************************* * REPORTING * *******************************/ %% file_coverage(+Succeeded, +Failed) is det. % % Write a report on the clauses covered organised by file to % current output. file_coverage(Succeeded, Failed) :- format('~N~n~`=t~78|~n'), format('~tCoverage by File~t~78|~n'), format('~`=t~78|~n'), format('~w~t~w~64|~t~w~72|~t~w~78|~n', ['File', 'Clauses', '%Cov', '%Fail']), format('~`=t~78|~n'), forall(source_file(File), file_coverage(File, Succeeded, Failed)), format('~`=t~78|~n'). file_coverage(File, Succeeded, Failed) :- findall(Cl, clause_source(Cl, File, _), Clauses), sort(Clauses, All), ( ord_intersect(All, Succeeded) -> true ; ord_intersect(All, Failed) ), !, ord_intersection(All, Failed, FailedInFile), ord_intersection(All, Succeeded, SucceededInFile), ord_subtract(All, SucceededInFile, UnCov1), ord_subtract(UnCov1, FailedInFile, Uncovered), length(All, AC), length(Uncovered, UC), length(FailedInFile, FC), CP is 100-100*UC/AC, FCP is 100*FC/AC, summary(File, 56, SFile), format('~w~t ~D~64| ~t~1f~72| ~t~1f~78|~n', [SFile, AC, CP, FCP]). file_coverage(_,_,_). summary(Atom, MaxLen, Summary) :- atom_length(Atom, Len), ( Len < MaxLen -> Summary = Atom ; SLen is MaxLen - 5, sub_atom(Atom, _, SLen, 0, End), atom_concat('...', End, Summary) ). %% clause_source(+Clause, -File, -Line) is det. %% clause_source(-Clause, +File, -Line) is det. clause_source(Clause, File, Line) :- nonvar(Clause), !, clause_property(Clause, file(File)), clause_property(Clause, line_count(Line)). clause_source(Clause, File, Line) :- source_file(Pred, File), \+ predicate_property(Pred, multifile), nth_clause(Pred, _Index, Clause), clause_property(Clause, line_count(Line)). clause_source(Clause, File, Line) :- Pred = _:_, predicate_property(Pred, multifile), nth_clause(Pred, _Index, Clause), clause_property(Clause, file(File)), clause_property(Clause, line_count(Line)).