/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@cs.vu.nl
WWW: http://www.swi-prolog.org
Copyright (C): 2012, VU University 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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_codewalk,
[ prolog_walk_code/1 % +Options
]).
:- use_module(library(option)).
:- use_module(library(record)).
:- use_module(library(debug)).
:- use_module(library(apply)).
:- use_module(library(lists)).
:- use_module(library(prolog_metainference)).
/** <module> Prolog code walker
This module walks over the loaded program, searching for callable
predicates. It started as part of library(prolog_autoload) and has been
turned into a seperate module to facilitate operations that require the
same reachability analysis, such as finding references to a predicate,
finding unreachable code, etc.
For example, the following determins the call graph of the loaded
program. By using source(true), The exact location of the call in the
source file is passed into _Where.
==
:- dynamic
calls/2.
assert_call_graph :-
retractall(calls(_, _)),
prolog_walk_code([ trace_reference(_),
on_trace(assert_edge),
source(false)
]),
predicate_property(calls(_,_), number_of_clauses(N)),
format('Got ~D edges~n', [N]).
assert_edge(Callee, Caller, _Where) :-
calls(Caller, Callee), !.
assert_edge(Callee, Caller, _Where) :-
assertz(calls(Caller, Callee)).
==
*/
:- meta_predicate
prolog_walk_code(:).
:- predicate_options(prolog_walk_code/1, 1,
[ undefined(oneof([ignore,error,trace])),
autoload(boolean),
module(atom),
module_class(list(oneof([user,system,library,
test,development]))),
source(boolean),
trace_reference(any),
on_trace(callable),
infer_meta_predicates(oneof([false,true,all])),
evaluate(boolean)
]).
:- record
walk_option(undefined:oneof([ignore,error,trace])=ignore,
autoload:boolean=true,
source:boolean=true,
module:atom, % Only analyse given module
module_class:list(oneof([user,system,library,
test,development]))=[user,library],
infer_meta_predicates:oneof([false,true,all])=true,
trace_reference:any=(-),
on_trace:callable, % Call-back on trace hits
% private stuff
clause, % Processed clause
caller, % Head of the caller
initialization, % Initialization source
undecided, % Error to throw error
evaluate:boolean). % Do partial evaluation
:- thread_local
multifile_predicate/3. % Name, Arity, Module
%% prolog_walk_code(+Options) is det.
%
% Walk over all loaded (user) Prolog code. The following code is
% processed:
%
% 1. The bodies of all clauses in all user and library modules.
% This steps collects, but does not scan multifile predicates
% to avoid duplicate work.
% 2. All multi-file predicates collected.
% 3. All goals registered with initialization/1
%
% Options processed:
%
% * undefined(+Action)
% Action defines what happens if the analysis finds a
% definitely undefined predicate. One of =ignore= or
% =error=.
%
% * autoload(+Boolean)
% Try to autoload code while walking. This is enabled by default
% to obtain as much as possible information about goals and find
% references from autoloaded libraries.
%
% * module(+Module)
% Only process the given module
%
% * module_class(+ModuleClass)
% Limit processing to modules of this class. See
% module_property/2 for details on module classes. Default
% is to scan the classes =user= and =library=.
%
% * infer_meta_predicates(+BooleanOrAll)
% Use infer_meta_predicate/2 on predicates with clauses that
% call known meta-predicates. The analysis is restarted until
% a fixed point is reached. If =true= (default), analysis is
% only restarted if the inferred meta-predicate contains a
% callable argument. If =all=, it will be restarted until no
% more new meta-predicates can be found.
%
% * trace_reference(Callable)
% Print all calls to goals that subsume Callable. Goals are
% represented as Module:Callable (i.e., they are always
% qualified). See also subsumes_term/2.
%
% * on_trace(:OnTrace)
% If a reference to =trace_reference= is found, call
% call(OnTrace, Callee, Caller, Location), where Location is one
% of these:
%
% - clause_term_position(+ClauseRef, +TermPos)
% - clause(+ClauseRef)
% - file_term_position(+Path, +TermPos)
% - file(+File, +Line, -1, _)
% - a variable (unknown)
%
% Caller is the qualified head of the calling clause or the
% atom '<initialization>'.
%
% * source(+Boolean)
% If =false= (default =true=), to not try to obtain detailed
% source information for printed messages.
%
% @compat OnTrace was called using Caller-Location in older
% versions.
prolog_walk_code(Options) :-
meta_options(is_meta, Options, QOptions),
prolog_walk_code(1, QOptions).
prolog_walk_code(Iteration, Options) :-
statistics(cputime, CPU0),
make_walk_option(Options, OTerm, _),
forall(( walk_option_module(OTerm, M),
current_module(M),
scan_module(M, OTerm)
),
find_walk_from_module(M, OTerm)),
walk_from_multifile(OTerm),
walk_from_initialization(OTerm),
infer_new_meta_predicates(New, OTerm),
statistics(cputime, CPU1),
( New \== []
-> CPU is CPU1-CPU0,
print_message(informational,
codewalk(reiterate(New, Iteration, CPU))),
succ(Iteration, Iteration2),
prolog_walk_code(Iteration2, Options)
; true
).
is_meta(on_trace).
%% scan_module(+Module, +OTerm) is semidet.
%
% True if we must scan Module according to OTerm.
scan_module(M, OTerm) :-
walk_option_module_class(OTerm, Classes),
module_property(M, class(Class)),
memberchk(Class, Classes).
%% walk_from_initialization(+OTerm)
%
% Find initialization/1,2 directives and process what they are
% calling. Skip
%
% @bug Relies on private '$init_goal'/3 database.
walk_from_initialization(OTerm) :-
walk_option_caller(OTerm, '<initialization>'),
forall('$init_goal'(_File, Goal, SourceLocation),
( walk_option_initialization(OTerm, SourceLocation),
walk_from_initialization(Goal, OTerm))).
walk_from_initialization(M:Goal, OTerm) :-
scan_module(M, OTerm), !,
walk_called_by_body(Goal, M, OTerm).
walk_from_initialization(_, _).
%% find_walk_from_module(+Module, +OTerm) is det.
%
% Find undefined calls from the bodies of all clauses that belong
% to Module.
find_walk_from_module(M, OTerm) :-
debug(autoload, 'Analysing module ~q', [M]),
forall(predicate_in_module(M, PI),
walk_called_by_pred(M:PI, OTerm)).
walk_called_by_pred(Module:Name/Arity, _) :-
multifile_predicate(Name, Arity, Module), !.
walk_called_by_pred(Module:Name/Arity, _) :-
functor(Head, Name, Arity),
predicate_property(Module:Head, multifile), !,
assertz(multifile_predicate(Name, Arity, Module)).
walk_called_by_pred(Module:Name/Arity, OTerm) :-
functor(Head, Name, Arity),
( no_walk_property(Property),
predicate_property(Module:Head, Property)
-> true
; walk_option_caller(OTerm, Module:Head),
walk_option_clause(OTerm, ClauseRef),
forall(catch(clause(Module:Head, Body, ClauseRef), _, fail),
walk_called_by_body(Body, Module, OTerm))
).
no_walk_property(number_of_rules(0)). % no point walking only facts
no_walk_property(foreign). % cannot walk foreign code
%% walk_from_multifile(+OTerm)
%
% Process registered multifile predicates.
walk_from_multifile(OTerm) :-
forall(retract(multifile_predicate(Name, Arity, Module)),
walk_called_by_multifile(Module:Name/Arity, OTerm)).
walk_called_by_multifile(Module:Name/Arity, OTerm) :-
functor(Head, Name, Arity),
forall(catch(clause_not_from_development(
Module:Head, Body, ClauseRef, OTerm),
_, fail),
( walk_option_clause(OTerm, ClauseRef),
walk_option_caller(OTerm, Module:Head),
walk_called_by_body(Body, Module, OTerm)
)).
%% clause_not_from_development(:Head, -Body, ?Ref, +Options) is nondet.
%
% Enumerate clauses for a multifile predicate, but omit those from
% a module that is specifically meant to support development.
clause_not_from_development(Module:Head, Body, Ref, OTerm) :-
clause(Module:Head, Body, Ref),
\+ ( clause_property(Ref, file(File)),
module_property(LoadModule, file(File)),
\+ scan_module(LoadModule, OTerm)
).
%% walk_called_by_body(+Body, +Module, +OTerm) is det.
%
% Check the Body term when executed in the context of Module.
% Options:
%
% - undefined(+Action)
% One of =ignore=, =error=
walk_called_by_body(True, _, _) :-
True == true, !. % quickly deal with facts
walk_called_by_body(Body, Module, OTerm) :-
set_undecided_of_walk_option(error, OTerm, OTerm1),
set_evaluate_of_walk_option(false, OTerm1, OTerm2),
catch(walk_called(Body, Module, _TermPos, OTerm2),
missing(Missing),
walk_called_by_body(Missing, Body, Module, OTerm)), !.
walk_called_by_body(Body, Module, OTerm) :-
format(user_error, 'Failed to analyse:~n', []),
portray_clause(('<head>' :- Body)),
( debugging(autoload(trace))
-> gtrace,
walk_called_by_body(Body, Module, OTerm)
; true
).
%% walk_called_by_body(+Missing, +Body, +Module, +OTerm)
%
% Restart the analysis because the previous analysis provided
% insufficient information.
walk_called_by_body(Missing, Body, _, OTerm) :-
debugging(autoload),
format(user_error, 'Retrying due to ~w (~p)~n', [Missing, OTerm]),
portray_clause(('<head>' :- Body)), fail.
walk_called_by_body(undecided_call, Body, Module, OTerm) :-
catch(forall(walk_called(Body, Module, _TermPos, OTerm),
true),
missing(Missing),
walk_called_by_body(Missing, Body, Module, OTerm)).
walk_called_by_body(subterm_positions, Body, Module, OTerm) :-
( ( walk_option_clause(OTerm, ClauseRef), nonvar(ClauseRef),
clause_info(ClauseRef, _, TermPos, _NameOffset),
TermPos = term_position(_,_,_,_,[_,BodyPos])
-> WBody = Body
; walk_option_initialization(OTerm, SrcLoc),
ground(SrcLoc), SrcLoc = _File:_Line,
initialization_layout(SrcLoc, Module:Body, WBody, BodyPos)
)
-> catch(forall(walk_called(WBody, Module, BodyPos, OTerm),
true),
missing(subterm_positions),
walk_called_by_body(no_positions, Body, Module, OTerm))
; set_source_of_walk_option(false, OTerm, OTerm2),
forall(walk_called(Body, Module, BodyPos, OTerm2),
true)
).
walk_called_by_body(no_positions, Body, Module, OTerm) :-
set_source_of_walk_option(false, OTerm, OTerm2),
forall(walk_called(Body, Module, _NoPos, OTerm2),
true).
%% walk_called(+Goal, +Module, +TermPos, +OTerm) is multi.
%
% Perform abstract interpretation of Goal, touching all sub-goals
% that are directly called or immediately reachable through
% meta-calls. The actual auto-loading is performed by the
% predicate_property/2 call for meta-predicates.
%
% If Goal is disjunctive, walk_called succeeds with a
% choice-point. Backtracking analyses the alternative control
% path(s).
%
% Options:
%
% * undecided(+Action)
% How to deal with insifficiently instantiated terms in the
% call-tree. Values are:
%
% - ignore
% Silently ignore such goals
% - error
% Throw =undecided_call=
%
% * evaluate(+Boolean)
% If =true= (default), evaluate some goals. Notably =/2.
%
% @tbd Analyse e.g. assert((Head:-Body))?
walk_called(Var, _, TermPos, OTerm) :-
var(Var), !, % Incomplete analysis
undecided(Var, TermPos, OTerm).
walk_called(M:G, _, term_position(_,_,_,_,[MPos,Pos]), OTerm) :- !,
( nonvar(M)
-> walk_called(G, M, Pos, OTerm)
; undecided(M, MPos, OTerm)
).
walk_called((A,B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
walk_called(A, M, PA, OTerm),
walk_called(B, M, PB, OTerm).
walk_called((A;B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
( walk_option_evaluate(OTerm, Eval), Eval == true
-> Goal = (A;B),
setof(Goal,
( walk_called(A, M, PA, OTerm)
; walk_called(B, M, PB, OTerm)
),
Alts0),
variants(Alts0, Alts),
member(Goal, Alts)
; walk_called(A, M, PA, OTerm),
walk_called(B, M, PB, OTerm)
).
walk_called(Goal, Module, TermPos, OTerm) :-
walk_option_trace_reference(OTerm, To), To \== (-),
( subsumes_term(To, Module:Goal)
-> M2 = Module
; predicate_property(Module:Goal, imported_from(M2)),
subsumes_term(To, M2:Goal)
),
print_reference(M2:Goal, TermPos, trace, OTerm),
fail. % Continue search
walk_called(Goal, Module, _, OTerm) :-
evaluate(Goal, Module, OTerm), !.
walk_called(Goal, M, TermPos, OTerm) :-
prolog:called_by(Goal, Called),
Called \== [], !,
walk_called_by(Called, M, Goal, TermPos, OTerm).
walk_called(Meta, M, term_position(_,E,_,_,ArgPosList), OTerm) :-
( walk_option_autoload(OTerm, false)
-> nonvar(M),
'$get_predicate_attribute'(M:Meta, defined, 1)
; true
),
( predicate_property(M:Meta, meta_predicate(Head))
; inferred_meta_predicate(M:Meta, Head)
), !,
walk_option_clause(OTerm, ClauseRef),
register_possible_meta_clause(ClauseRef),
walk_meta_call(1, Head, Meta, M, ArgPosList, E-E, OTerm).
walk_called(Goal, Module, _, _) :-
nonvar(Module),
'$get_predicate_attribute'(Module:Goal, defined, 1), !.
walk_called(Goal, Module, TermPos, OTerm) :-
callable(Goal), !,
undefined(Module:Goal, TermPos, OTerm).
walk_called(Goal, _Module, TermPos, OTerm) :-
not_callable(Goal, TermPos, OTerm).
%% undecided(+Variable, +TermPos, +OTerm)
undecided(Var, TermPos, OTerm) :-
walk_option_undecided(OTerm, Undecided),
( var(Undecided)
-> Action = ignore
; Action = Undecided
),
undecided(Action, Var, TermPos, OTerm).
undecided(ignore, _, _, _) :- !.
undecided(error, _, _, _) :-
throw(missing(undecided_call)).
%% evaluate(Goal, Module, OTerm) is nondet.
evaluate(Goal, Module, OTerm) :-
walk_option_evaluate(OTerm, Evaluate),
Evaluate \== false,
evaluate(Goal, Module).
evaluate(A=B, _) :-
unify_with_occurs_check(A, B).
%% undefined(:Goal, +TermPos, +OTerm)
%
% The analysis trapped a definitely undefined predicate.
undefined(_, _, OTerm) :-
walk_option_undefined(OTerm, ignore), !.
undefined(Goal, _, _) :-
predicate_property(Goal, autoload(_)), !.
undefined(Goal, TermPos, OTerm) :-
( walk_option_undefined(OTerm, trace)
-> Why = trace
; Why = undefined
),
print_reference(Goal, TermPos, Why, OTerm).
%% not_callable(+Goal, +TermPos, +OTerm)
%
% We found a reference to a non-callable term
not_callable(Goal, TermPos, OTerm) :-
print_reference(Goal, TermPos, not_callable, OTerm).
%% print_reference(+Goal, +TermPos, +Why, +OTerm)
%
% Print a reference to Goal, found at TermPos.
%
% @param Why is one of =trace= or =undefined=
print_reference(Goal, TermPos, Why, OTerm) :-
walk_option_clause(OTerm, Clause), nonvar(Clause), !,
( compound(TermPos),
arg(1, TermPos, CharCount),
integer(CharCount) % test it is valid
-> From = clause_term_position(Clause, TermPos)
; walk_option_source(OTerm, false)
-> From = clause(Clause)
; throw(missing(subterm_positions))
),
print_reference2(Goal, From, Why, OTerm).
print_reference(Goal, TermPos, Why, OTerm) :-
walk_option_initialization(OTerm, Init), nonvar(Init),
Init = File:Line, !,
( compound(TermPos),
arg(1, TermPos, CharCount),
integer(CharCount) % test it is valid
-> From = file_term_position(File, TermPos)
; walk_option_source(OTerm, false)
-> From = file(File, Line, -1, _)
; throw(missing(subterm_positions))
),
print_reference2(Goal, From, Why, OTerm).
print_reference(Goal, _, Why, OTerm) :-
print_reference2(Goal, _, Why, OTerm).
print_reference2(Goal, From, trace, OTerm) :-
walk_option_on_trace(OTerm, Closure),
walk_option_caller(OTerm, Caller),
nonvar(Closure),
call(Closure, Goal, Caller, From), !.
print_reference2(Goal, From, Why, _OTerm) :-
make_message(Why, Goal, From, Message, Level),
print_message(Level, Message).
make_message(undefined, Goal, Context,
error(existence_error(procedure, PI), Context), error) :-
goal_pi(Goal, PI).
make_message(not_callable, Goal, Context,
error(type_error(callable, Goal), Context), error).
make_message(trace, Goal, Context,
trace_call_to(PI, Context), informational) :-
goal_pi(Goal, PI).
goal_pi(Goal, M:Name/Arity) :-
strip_module(Goal, M, Head),
callable(Head), !,
functor(Head, Name, Arity).
goal_pi(Goal, Goal).
:- dynamic
possible_meta_predicate/2.
%% register_possible_meta_clause(+ClauseRef) is det.
%
% ClausesRef contains as call to a meta-predicate. Remember to
% analyse this predicate. We only analyse the predicate if it is
% loaded from a user module. I.e., system and library modules are
% trusted.
register_possible_meta_clause(ClausesRef) :-
nonvar(ClausesRef),
clause_property(ClausesRef, predicate(PI)),
pi_head(PI, Head, Module),
module_property(Module, class(user)),
\+ predicate_property(Module:Head, meta_predicate(_)),
\+ inferred_meta_predicate(Module:Head, _),
\+ possible_meta_predicate(Head, Module), !,
assertz(possible_meta_predicate(Head, Module)).
register_possible_meta_clause(_).
pi_head(Module:Name/Arity, Head, Module) :- !,
functor(Head, Name, Arity).
pi_head(_, _, _) :-
assertion(fail).
%% infer_new_meta_predicates(-MetaSpecs, +OTerm) is det.
infer_new_meta_predicates([], OTerm) :-
walk_option_infer_meta_predicates(OTerm, false), !.
infer_new_meta_predicates(MetaSpecs, OTerm) :-
findall(Module:MetaSpec,
( retract(possible_meta_predicate(Head, Module)),
infer_meta_predicate(Module:Head, MetaSpec),
( walk_option_infer_meta_predicates(OTerm, all)
-> true
; calling_metaspec(MetaSpec)
)
),
MetaSpecs).
%% calling_metaspec(+Head) is semidet.
%
% True if this is a meta-specification that makes a difference to
% the code walker.
calling_metaspec(Head) :-
arg(_, Head, Arg),
calling_metaarg(Arg), !.
calling_metaarg(I) :- integer(I), !.
calling_metaarg(^).
calling_metaarg(//).
%% walk_meta_call(+Index, +GoalHead, +MetaHead, +Module,
%% +ArgPosList, +EndPos, +OTerm)
%
% Walk a call to a meta-predicate. This walks all meta-arguments
% labeled with an integer, ^ or //.
%
% @arg EndPos reflects the end of the term. This is used if the
% number of arguments in the compiled form exceeds the
% number of arguments in the term read.
walk_meta_call(I, Head, Meta, M, ArgPosList, EPos, OTerm) :-
arg(I, Head, AS), !,
( ArgPosList = [ArgPos|ArgPosTail]
-> true
; ArgPos = EPos,
ArgPosTail = []
),
( integer(AS)
-> arg(I, Meta, MA),
extend(MA, AS, Goal, ArgPos, ArgPosEx, OTerm),
walk_called(Goal, M, ArgPosEx, OTerm)
; AS == (^)
-> arg(I, Meta, MA),
remove_quantifier(MA, Goal, ArgPos, ArgPosEx, M, MG, OTerm),
walk_called(Goal, MG, ArgPosEx, OTerm)
; AS == (//)
-> arg(I, Meta, DCG),
walk_dcg_body(DCG, M, ArgPos, OTerm)
; true
),
succ(I, I2),
walk_meta_call(I2, Head, Meta, M, ArgPosTail, EPos, OTerm).
walk_meta_call(_, _, _, _, _, _, _).
remove_quantifier(Goal, _, TermPos, TermPos, M, M, OTerm) :-
var(Goal), !,
undecided(Goal, TermPos, OTerm).
remove_quantifier(_^Goal0, Goal,
term_position(_,_,_,_,[_,GPos]),
TermPos, M0, M, OTerm) :- !,
remove_quantifier(Goal0, Goal, GPos, TermPos, M0, M, OTerm).
remove_quantifier(M1:Goal0, Goal,
term_position(_,_,_,_,[_,GPos]),
TermPos, _, M, OTerm) :- !,
remove_quantifier(Goal0, Goal, GPos, TermPos, M1, M, OTerm).
remove_quantifier(Goal, Goal, TermPos, TermPos, M, M, _).
%% walk_called_by(+Called:list, +Module, +Goal, +TermPos, +OTerm)
%
% Walk code explicitly mentioned to be called through the hook
% prolog:called_by/2.
walk_called_by([], _, _, _, _).
walk_called_by([H|T], M, Goal, TermPos, OTerm) :-
( H = G+N
-> subterm_pos(G, Goal, TermPos, GPos),
( extend(G, N, G2, GPos, GPosEx, OTerm)
-> walk_called(G2, M, GPosEx, OTerm)
; true
)
; subterm_pos(G, Goal, TermPos, GPos),
walk_called(H, M, GPos, OTerm)
),
walk_called_by(T, M, Goal, TermPos, OTerm).
subterm_pos(Sub, Term, TermPos, SubTermPos) :-
subterm_pos(Sub, Term, same_term, TermPos, SubTermPos), !.
subterm_pos(Sub, Term, TermPos, SubTermPos) :-
subterm_pos(Sub, Term, ==, TermPos, SubTermPos), !.
subterm_pos(Sub, Term, TermPos, SubTermPos) :-
subterm_pos(Sub, Term, =@=, TermPos, SubTermPos), !.
subterm_pos(Sub, Term, TermPos, SubTermPos) :-
subterm_pos(Sub, Term, =, TermPos, SubTermPos), !.
subterm_pos(_, _, _, _).
%% walk_dcg_body(+Body, +Module, +TermPos, +OTerm)
%
% Walk a DCG body that is meta-called.
walk_dcg_body(Var, _Module, TermPos, OTerm) :-
var(Var), !,
undecided(Var, TermPos, OTerm).
walk_dcg_body([], _Module, _, _) :- !.
walk_dcg_body([_|_], _Module, _, _) :- !.
walk_dcg_body(!, _Module, _, _) :- !.
walk_dcg_body(M:G, _, term_position(_,_,_,_,[MPos,Pos]), OTerm) :- !,
( nonvar(M)
-> walk_dcg_body(G, M, Pos, OTerm)
; undecided(M, MPos, OTerm)
).
walk_dcg_body((A,B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
walk_dcg_body(A, M, PA, OTerm),
walk_dcg_body(B, M, PB, OTerm).
walk_dcg_body((A->B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
walk_dcg_body(A, M, PA, OTerm),
walk_dcg_body(B, M, PB, OTerm).
walk_dcg_body((A*->B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
walk_dcg_body(A, M, PA, OTerm),
walk_dcg_body(B, M, PB, OTerm).
walk_dcg_body((A;B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
( walk_dcg_body(A, M, PA, OTerm)
; walk_dcg_body(B, M, PB, OTerm)
).
walk_dcg_body((A|B), M, term_position(_,_,_,_,[PA,PB]), OTerm) :- !,
( walk_dcg_body(A, M, PA, OTerm)
; walk_dcg_body(B, M, PB, OTerm)
).
walk_dcg_body(G, M, TermPos, OTerm) :-
extend(G, 2, G2, TermPos, TermPosEx, OTerm),
walk_called(G2, M, TermPosEx, OTerm).
%% subterm_pos(+SubTerm, +Term, :Cmp,
%% +TermPosition, -SubTermPos) is nondet.
%
% True when SubTerm is a sub term of Term, compared using Cmp,
% TermPosition describes the term layout of Term and SubTermPos
% describes the term layout of SubTerm. Cmp is typically one of
% =same_term=, =|==|=, =|=@=|= or =|=|=
:- meta_predicate
subterm_pos(+, +, 2, +, -),
sublist_pos(+, +, +, +, 2, -).
subterm_pos(_, _, _, Pos, _) :-
var(Pos), !, fail.
subterm_pos(Sub, Term, Cmp, Pos, Pos) :-
call(Cmp, Sub, Term), !.
subterm_pos(Sub, Term, Cmp, term_position(_,_,_,_,ArgPosList), Pos) :-
nth1(I, ArgPosList, ArgPos),
arg(I, Term, Arg),
subterm_pos(Sub, Arg, Cmp, ArgPos, Pos).
subterm_pos(Sub, Term, Cmp, list_position(_,_,ElemPosList,TailPos), Pos) :-
sublist_pos(ElemPosList, TailPos, Sub, Term, Cmp, Pos).
subterm_pos(Sub, {Arg}, Cmp, brace_term_position(_,_,ArgPos), Pos) :-
subterm_pos(Sub, Arg, Cmp, ArgPos, Pos).
sublist_pos([EP|TP], TailPos, Sub, [H|T], Cmp, Pos) :-
( subterm_pos(Sub, H, Cmp, EP, Pos)
; sublist_pos(TP, TailPos, Sub, T, Cmp, Pos)
).
sublist_pos([], TailPos, Sub, Tail, Cmp, Pos) :-
TailPos \== none,
subterm_pos(Sub, Tail, Cmp, TailPos, Pos).
%% extend(+Goal, +ExtraArgs, +TermPosIn, -TermPosOut, +OTerm)
%
% @bug:
extend(Goal, 0, Goal, TermPos, TermPos, _) :- !.
extend(Goal, _, _, TermPos, TermPos, OTerm) :-
var(Goal), !,
undecided(Goal, TermPos, OTerm).
extend(M:Goal, N, M:GoalEx,
term_position(F,T,FT,TT,[MPos,GPosIn]),
term_position(F,T,FT,TT,[MPos,GPosOut]), OTerm) :- !,
( var(M)
-> undecided(N, MPos, OTerm)
; true
),
extend(Goal, N, GoalEx, GPosIn, GPosOut, OTerm).
extend(Goal, N, GoalEx, TermPosIn, TermPosOut, _) :-
callable(Goal),
Goal =.. List,
length(Extra, N),
extend_term_pos(TermPosIn, N, TermPosOut),
append(List, Extra, ListEx),
GoalEx =.. ListEx.
extend_term_pos(Var, _, _) :-
var(Var), !.
extend_term_pos(term_position(F,T,FT,TT,ArgPosIn),
N,
term_position(F,T,FT,TT,ArgPosOut)) :- !,
length(Extra, N),
maplist(=(0-0), Extra),
append(ArgPosIn, Extra, ArgPosOut).
extend_term_pos(F-T, N, term_position(F,T,F,T,Extra)) :-
length(Extra, N),
maplist(=(0-0), Extra).
%% variants(+SortedList, -Variants) is det.
variants([], []).
variants([H|T], List) :-
variants(T, H, List).
variants([], H, [H]).
variants([H|T], V, List) :-
( H =@= V
-> variants(T, V, List)
; List = [V|List2],
variants(T, H, List2)
).
%% predicate_in_module(+Module, ?PI) is nondet.
%
% True if PI is a predicate locally defined in Module.
predicate_in_module(Module, PI) :-
current_predicate(Module:PI),
PI = Name/Arity,
functor(Head, Name, Arity),
\+ predicate_property(Module:Head, imported_from(_)).
/*******************************
* MESSAGES *
*******************************/
:- multifile
prolog:message//1,
prolog:message_location//1.
prolog:message(trace_call_to(PI, Context)) -->
[ 'Call to ~q at '-[PI] ],
prolog:message_location(Context).
prolog:message_location(clause_term_position(ClauseRef, TermPos)) -->
{ clause_property(ClauseRef, file(File)) },
message_location_file_term_position(File, TermPos).
prolog:message_location(clause(ClauseRef)) -->
{ clause_property(ClauseRef, file(File)),
clause_property(ClauseRef, line_count(Line))
}, !,
[ '~w:~d: '-[File, Line] ].
prolog:message_location(clause(ClauseRef)) -->
{ clause_name(ClauseRef, Name) },
[ '~w: '-[Name] ].
prolog:message_location(file_term_position(Path, TermPos)) -->
message_location_file_term_position(Path, TermPos).
prolog:message_location(file(Path, Line, _, _)) -->
[ '~w:~d: '-[Path, Line] ].
prolog:message(codewalk(reiterate(New, Iteration, CPU))) -->
[ 'Found new meta-predicates in iteration ~w (~3f sec)'-
[Iteration, CPU], nl ],
meta_decls(New),
[ 'Restarting analysis ...'-[], nl ].
meta_decls([]) --> [].
meta_decls([H|T]) -->
[ ':- meta_predicate ~q.'-[H], nl ],
meta_decls(T).
message_location_file_term_position(File, TermPos) -->
{ arg(1, TermPos, CharCount),
filepos_line(File, CharCount, Line, LinePos)
},
[ '~w:~d:~d: '-[File, Line, LinePos] ].
%% filepos_line(+File, +CharPos, -Line, -Column) is det.
%
% @param CharPos is 0-based character offset in the file.
% @param Column is the current column, counting tabs as 8 spaces.
filepos_line(File, CharPos, Line, LinePos) :-
setup_call_cleanup(
( open(File, read, In),
open_null_stream(Out)
),
( copy_stream_data(In, Out, CharPos),
stream_property(In, position(Pos)),
stream_position_data(line_count, Pos, Line),
stream_position_data(line_position, Pos, LinePos)
),
( close(Out),
close(In)
)).