/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@cs.vu.nl WWW: http://www.swi-prolog.org Copyright (C): 2011, 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(predicate_options, [ predicate_options/3, % +PI, +Arg, +Options assert_predicate_options/4, % +PI, +Arg, +Options, ?New current_option_arg/2, % ?PI, ?Arg current_predicate_option/3, % ?PI, ?Arg, ?Option check_predicate_option/3, % +PI, +Arg, +Option % Create declarations current_predicate_options/3, % ?PI, ?Arg, ?Options retractall_predicate_options/0, derived_predicate_options/3, % :PI, ?Arg, ?Options derived_predicate_options/1, % +Module % Checking check_predicate_options/0, derive_predicate_options/0, check_predicate_options/1 % :PredicateIndicator ]). :- use_module(library(lists)). :- use_module(library(pairs)). :- use_module(library(error)). :- use_module(library(lists)). :- use_module(library(debug)). :- use_module(library(prolog_clause)). :- meta_predicate predicate_options(:, +, +), assert_predicate_options(:, +, +, ?), current_predicate_option(:, ?, ?), check_predicate_option(:, ?, ?), current_predicate_options(:, ?, ?), current_option_arg(:, ?), pred_option(:,-), derived_predicate_options(:,?,?), check_predicate_options(:). /** Access and analyse predicate options This module provides the developers interface for the directive predicate_options/3. This directive allows us to specify that e.g., open/4 processes options using the 4th argument and supports the option =type= using the values =text= and =binary=. Declaring options that are processed allows for more reliable handling of predicate options and simplifies porting applications. This libarry provides the following functionality: * Query supported options through current_predicate_option/3 or current_predicate_options/3. This is intended to support conditional compilation and an IDE. * Derive additional declarations through dataflow analysis using derive_predicate_options/0. * Perform a compile-time analysis of the entire loaded program using check_predicate_options/0. Below, we describe some use-cases. $ Quick check of a program : This scenario is useful as an occasional check or to assess problems with option-handling for porting an application to SWI-Prolog. It consists of three steps: loading the program (1 and 2), deriving option handling for application predicates (3) and running the checker (4). == 1 ?- [load]. 2 ?- autoload. 3 ?- derive_predicate_options. 4 ?- check_predicate_options. == $ Add declaations to your program : Adding declarations about option processes improves the quality of the checking. The analysis of derive_predicate_options/0 may miss options and does not derive the types for options that are processed in Prolog code. The process is similar to the above. In steps 4 and further, the inferred declarations are listed, inspected and added to the source-code of the module. == 1 ?- [load]. 2 ?- autoload. 3 ?- derive_predicate_options. 4 ?- derived_predicate_options(module_1). 5 ?- derived_predicate_options(module_2). 6 ?- ... == $ Declare option processing requirements : If an application requires that open/4 needs to support lock(write), it may do so using the derective below. This directive raises an exception when loaded on a Prolog implementation that does not support this option. == :- current_predicate_option(open/4, 4, lock(write)). == @see library(option) for accessing options in Prolog code. */ :- multifile option_decl/3, pred_option/3. :- dynamic dyn_option_decl/3. %% predicate_options(:PI, +Arg, +Options) is det. % % Declare that the predicate PI processes options on Arg. Options % is a list of options processed. Each element is one of: % % * Option(ModeAndType) % PI processes Option. The option-value must comply to % ModeAndType. Mode is one of + or - and Type is a type as % accepted by must_be/2. % % * pass_to(:PI,Arg) % The option-list is passed to the indicated predicate. % % Below is an example that processes the option header(boolean) % and passes all options to open/4: % % == % :- predicate_options(write_xml_file/3, 3, % [ header(boolean), % pass_to(open/4, 4) % ]). % % write_xml_file(File, XMLTerm, Options) :- % open(File, write, Out, Options), % ( option(header(true), Option, true) % -> write_xml_header(Out) % ; true % ), % ... % == % % This predicate may only be used as a _directive_ and is % processed by expand_term/2. Option processing can be be % specified at runtime using assert_predicate_options/3, which is % intended to support program analysis. predicate_options(PI, Arg, Options) :- throw(error(context_error(nodirective, predicate_options(PI, Arg, Options)), _)). %% assert_predicate_options(:PI, +Arg, +Options, ?New) is semidet. % % As predicate_options(:PI, +Arg, +Options). New is a boolean % indicating whether the declarations have changed. If new is % provided and =false=, the predicate becomes semidet and fails % without modifications if modifications are required. assert_predicate_options(PI, Arg, Options, New) :- canonical_pi(PI, M:Name/Arity), functor(Head, Name, Arity), ( dyn_option_decl(Head, M, Arg) -> true ; New = true, assertz(dyn_option_decl(Head, M, Arg)) ), phrase('$predopts':option_clauses(Options, Head, M, Arg), OptionClauses), forall(member(Clause, OptionClauses), assert_option_clause(Clause, New)), ( var(New) -> New = false ; true ). assert_option_clause(Clause, New) :- rename_clause(Clause, NewClause, '$pred_option'(A,B,C,D), '$dyn_pred_option'(A,B,C,D)), clause_head(NewClause, NewHead), ( clause(NewHead, _) -> true ; New = true, assertz(NewClause) ). clause_head(M:(Head:-_Body), M:Head) :- !. clause_head((M:Head :-_Body), M:Head) :- !. clause_head(Head, Head). rename_clause(M:Clause, M:NewClause, Head, NewHead) :- !, rename_clause(Clause, NewClause, Head, NewHead). rename_clause((Head :- Body), (NewHead :- Body), Head, NewHead) :- !. rename_clause(Head, NewHead, Head, NewHead) :- !. rename_clause(Head, Head, _, _). /******************************* * QUERY OPTIONS * *******************************/ %% current_option_arg(:PI, ?Arg) is nondet. % % True when Arg of PI processes predicate options. Which options % are processed can be accessed using current_predicate_option/3. current_option_arg(Module:Name/Arity, Arg) :- current_option_arg(Module:Name/Arity, Arg, _DefM). current_option_arg(Module:Name/Arity, Arg, DefM) :- atom(Name), integer(Arity), !, resolve_module(Module:Name/Arity, DefM:Name/Arity), functor(Head, Name, Arity), ( option_decl(Head, DefM, Arg) ; dyn_option_decl(Head, DefM, Arg) ). current_option_arg(M:Name/Arity, Arg, M) :- ( option_decl(Head, M, Arg) ; dyn_option_decl(Head, M, Arg) ), functor(Head, Name, Arity). %% current_predicate_option(:PI, ?Arg, ?Option) is nondet. % % True when Arg of PI processes Option. For example, the following % is true: % % == % ?- current_predicate_option(open/4, 4, type(text)). % true. % == % % This predicate is intended to support conditional compilation % using if/1 ... endif/0. The predicate % current_predicate_options/3 can be used to access the full % capabilities of a predicate. current_predicate_option(Module:PI, Arg, Option) :- current_option_arg(Module:PI, Arg, DefM), PI = Name/Arity, functor(Head, Name, Arity), catch(pred_option(DefM:Head, Option), error(type_error(_,_),_), fail). %% check_predicate_option(:PI, +Arg, +Option) is det. % % Similar to current_predicate_option/3, but intended to support % runtime checking. % % @error existence_error(option, OptionName) if the option is not % supported by PI. % @error type_error(Type, Value) if the option is supported but % the value does not match the option type. See must_be/2. check_predicate_option(Module:PI, Arg, Option) :- define_predicate(Module:PI), current_option_arg(Module:PI, Arg, DefM), PI = Name/Arity, functor(Head, Name, Arity), ( pred_option(DefM:Head, Option) -> true ; existence_error(option, Option) ). pred_option(M:Head, Option) :- pred_option(M:Head, Option, []). pred_option(M:Head, Option, Seen) :- ( has_static_option_decl(M), M:'$pred_option'(Head, _, Option, Seen) ; has_dynamic_option_decl(M), M:'$dyn_pred_option'(Head, _, Option, Seen) ). has_static_option_decl(M) :- '$c_current_predicate'(_, M:'$pred_option'(_,_,_,_)). has_dynamic_option_decl(M) :- '$c_current_predicate'(_, M:'$dyn_pred_option'(_,_,_,_)). /******************************* * TYPE&MODE CONSTRAINTS * *******************************/ :- public system:predicate_option_mode/2, system:predicate_option_type/2. add_attr(Var, Value) :- ( get_attr(Var, predicate_options, Old) -> put_attr(Var, predicate_options, [Value|Old]) ; put_attr(Var, predicate_options, [Value]) ). system:predicate_option_type(Type, Arg) :- var(Arg), !, add_attr(Arg, option_type(Type)). system:predicate_option_type(Type, Arg) :- must_be(Type, Arg). system:predicate_option_mode(Mode, Arg) :- var(Arg), !, add_attr(Arg, option_mode(Mode)). system:predicate_option_mode(Mode, Arg) :- check_mode(Mode, Arg). check_mode(input, Arg) :- ( nonvar(Arg) -> true ; instantiation_error(Arg) ). check_mode(output, Arg) :- ( var(Arg) -> true ; instantiation_error(Arg) % TBD: Uninstantiated ). attr_unify_hook([], _). attr_unify_hook([H|T], Var) :- option_hook(H, Var), attr_unify_hook(T, Var). option_hook(option_type(Type), Value) :- is_of_type(Type, Value). option_hook(option_mode(Mode), Value) :- check_mode(Mode, Value). attribute_goals(Var) --> { get_attr(Var, predicate_options, Attrs) }, option_goals(Attrs, Var). option_goals([], _) --> []. option_goals([H|T], Var) --> option_goal(H, Var), option_goals(T, Var). option_goal(option_type(Type), Var) --> [predicate_option_type(Type, Var)]. option_goal(option_mode(Mode), Var) --> [predicate_option_mode(Mode, Var)]. /******************************* * OUTPUT DECLARATIONS * *******************************/ %% current_predicate_options(:PI, ?Arg, ?Options) is nondet. % % True when Options is the current active option declaration for % PI on Arg. See predicate_options/3 for the argument % descriptions. If PI is ground and refers to an undefined % predicate, the autoloader is used to obtain a definition of the % predicate. current_predicate_options(PI, Arg, Options) :- define_predicate(PI), setof(Arg-Option, current_predicate_option_decl(PI, Arg, Option), Options0), group_pairs_by_key(Options0, Grouped), member(Arg-Options, Grouped). current_predicate_option_decl(PI, Arg, Option) :- current_predicate_option(PI, Arg, Option0), Option0 =.. [Name|Values], maplist(mode_and_type, Values, Types), Option =.. [Name|Types]. mode_and_type(Value, ModeAndType) :- copy_term(Value,_,Goals), ( memberchk(predicate_option_mode(output, _), Goals) -> ModeAndType = -(Type) ; ModeAndType = Type ), ( memberchk(predicate_option_type(Type, _), Goals) -> true ; Type = any ). define_predicate(PI) :- ground(PI), !, PI = M:Name/Arity, functor(Head, Name, Arity), once(predicate_property(M:Head, _)). define_predicate(_). %% derived_predicate_options(:PI, ?Arg, ?Options) is nondet. % % True when Options is the current _derived_ active option % declaration for PI on Arg. derived_predicate_options(PI, Arg, Options) :- define_predicate(PI), setof(Arg-Option, derived_predicate_option(PI, Arg, Option), Options0), group_pairs_by_key(Options0, Grouped), member(Arg-Options1, Grouped), PI = M:_, phrase(expand_pass_to_options(Options1, M), Options2), sort(Options2, Options). derived_predicate_option(PI, Arg, Decl) :- current_option_arg(PI, Arg, DefM), PI = _:Name/Arity, functor(Head, Name, Arity), has_dynamic_option_decl(DefM), ( has_static_option_decl(DefM), DefM:'$pred_option'(Head, Decl, _, []) ; DefM:'$dyn_pred_option'(Head, Decl, _, []) ). %% expand_pass_to_options(+OptionsIn, +Module, -OptionsOut)// is det. % % Expand the options of pass_to(PI,Arg) if PI does not refer to a % public predicate. expand_pass_to_options([], _) --> []. expand_pass_to_options([H|T], M) --> expand_pass_to(H, M), expand_pass_to_options(T, M). expand_pass_to(pass_to(PI, Arg), Module) --> { strip_module(Module:PI, M, Name/Arity), functor(Head, Name, Arity), \+ ( predicate_property(M:Head, exported) ; predicate_property(M:Head, public) ; M == system ), !, current_predicate_options(M:Name/Arity, Arg, Options) }, list(Options). expand_pass_to(Option, _) --> [Option]. list([]) --> []. list([H|T]) --> [H], list(T). %% derived_predicate_options(+Module) is det. % % Derive predicate option declarations for the given module and % print them to the current output. derived_predicate_options(Module) :- var(Module), !, forall(current_module(Module), derived_predicate_options(Module)). derived_predicate_options(Module) :- findall(predicate_options(Module:PI, Arg, Options), ( derived_predicate_options(Module:PI, Arg, Options), PI = Name/Arity, functor(Head, Name, Arity), ( predicate_property(Module:Head, exported) -> true ; predicate_property(Module:Head, public) ) ), Decls0), maplist(qualify_decl(Module), Decls0, Decls1), sort(Decls1, Decls), ( Decls \== [] -> format('~N~n~n% Predicate option declarations for module ~q~n~n', [Module]), forall(member(Decl, Decls), portray_clause((:-Decl))) ; true ). qualify_decl(M, predicate_options(PI0, Arg, Options0), predicate_options(PI1, Arg, Options1)) :- qualify(PI0, M, PI1), maplist(qualify_option(M), Options0, Options1). qualify_option(M, pass_to(PI0, Arg), pass_to(PI1, Arg)) :- !, qualify(PI0, M, PI1). qualify_option(_, Opt, Opt). qualify(M:Term, M, Term) :- !. qualify(QTerm, _, QTerm). /******************************* * CLEANUP * *******************************/ %% retractall_predicate_options is det. % % Remove all dynamically (derived) predicate options. retractall_predicate_options :- forall(retract(dyn_option_decl(_,M,_)), abolish(M:'$dyn_pred_option'/4)). /******************************* * COMPILE-TIME CHECKER * *******************************/ :- thread_local new_decl/1. %% check_predicate_options is det. % % Analyse loaded program for errornous options. This predicate % decompiles the current program and searches for calls to % predicates that process options. For each option list, it % validates whether the provided options are supported and % validates the argument type. This predicate performs partial % dataflow analysis to track option-lists inside a clause. % % @see derive_predicate_options/0 can be used to derive % declarations for predicates that pass options. This % predicate should normally be called before % check_predicate_options/0. check_predicate_options :- forall(current_module(Module), check_predicate_options_module(Module)). %% derive_predicate_options is det. % % Derive new predicate option declarations. This predicate % analyses the loaded program to find clauses that process options % using one of the predicates from library(option) or passes % options to other predicates that are known to process options. % The process is repeated until no new declarations are retrieved. % % @see autoload/0 may be used to complete the loaded program. derive_predicate_options :- derive_predicate_options(NewDecls), ( NewDecls == [] -> true ; print_message(informational, check_options(new(NewDecls))), new_decls(NewDecls), derive_predicate_options ). new_decls([]). new_decls([predicate_options(PI, A, O)|T]) :- assert_predicate_options(PI, A, O, _), new_decls(T). derive_predicate_options(NewDecls) :- call_cleanup( ( forall( current_module(Module), forall( ( predicate_in_module(Module, PI), PI = Name/Arity, functor(Head, Name, Arity), catch(Module:clause(Head, Body, Ref), _, fail) ), check_clause((Head:-Body), Module, Ref, decl))), ( setof(Decl, retract(new_decl(Decl)), NewDecls) -> true ; NewDecls = [] ) ), retractall(new_decl(_))). check_predicate_options_module(Module) :- forall(predicate_in_module(Module, PI), check_predicate_options(Module:PI)). predicate_in_module(Module, PI) :- current_predicate(Module:PI), PI = Name/Arity, functor(Head, Name, Arity), \+ predicate_property(Module:Head, imported_from(_)). %% check_predicate_options(:PredicateIndicator) is det. % % Verify calls to predicates that have options in all clauses of % the predicate indicated by PredicateIndicator. check_predicate_options(Module:Name/Arity) :- debug(predicate_options, 'Checking ~q', [Module:Name/Arity]), functor(Head, Name, Arity), forall(catch(Module:clause(Head, Body, Ref), _, fail), check_clause((Head:-Body), Module, Ref, check)). %% check_clause(+Clause, +Module, +Ref, +Action) is det. % % Action is one of % % * decl % Create additional declarations % * check % Produce error messages check_clause((Head:-Body), M, ClauseRef, Action) :- !, catch(check_body(Body, M, _, Action), E, true), ( var(E) -> option_decl(M:Head, Action) ; ( clause_info(ClauseRef, File, TermPos, _NameOffset), TermPos = term_position(_,_,_,_,[_,BodyPos]), catch(check_body(Body, M, BodyPos, Action), error(Formal, ArgPos), true), compound(ArgPos), arg(1, ArgPos, CharCount), integer(CharCount) -> Location = file_char_count(File, CharCount) ; Location = clause(ClauseRef), E = error(Formal, _) ), print_message(error, predicate_option_error(Formal, Location)) ). %% check_body(+Body, +Module, +TermPos, +Action) check_body(Var, _, _, _) :- var(Var), !. check_body(M:G, _, term_position(_,_,_,_,[_,Pos]), Action) :- !, check_body(G, M, Pos, Action). check_body((A,B), M, term_position(_,_,_,_,[PA,PB]), Action) :- !, check_body(A, M, PA, Action), check_body(B, M, PB, Action). check_body(A=B, _, _, _) :- % partial evaluation unify_with_occurs_check(A,B), !. check_body(Goal, M, term_position(_,_,_,_,ArgPosList), Action) :- callable(Goal), functor(Goal, Name, Arity), ( '$get_predicate_attribute'(M:Goal, imported, DefM) -> true ; DefM = M ), ( eval_option_pred(DefM:Goal) -> true ; current_option_arg(DefM:Name/Arity, OptArg), !, arg(OptArg, Goal, Options), nth1(OptArg, ArgPosList, ArgPos), check_options(DefM:Name/Arity, OptArg, Options, ArgPos, Action) ). check_body(Goal, M, _, Action) :- prolog:called_by(Goal, Called), !, check_called_by(Called, M, Action). check_body(Meta, M, term_position(_,_,_,_,ArgPosList), Action) :- '$get_predicate_attribute'(M:Meta, meta_predicate, Head), !, check_meta_args(1, Head, Meta, M, ArgPosList, Action). check_body(_, _, _, _). check_meta_args(I, Head, Meta, M, [ArgPos|ArgPosList], Action) :- arg(I, Head, AS), !, ( AS == 0 -> arg(I, Meta, MA), check_body(MA, M, ArgPos, Action) ; true ), succ(I, I2), check_meta_args(I2, Head, Meta, M, ArgPosList, Action). check_meta_args(_,_,_,_, _, _). %% check_called_by(+CalledBy, +M, +Action) is det. % % Handle results from prolog:called_by/2. check_called_by([], _, _). check_called_by([H|T], M, Action) :- ( H = G+N -> ( extend(G, N, G2) -> check_body(G2, M, _, Action) ; true ) ; check_body(H, M, _, Action) ), check_called_by(T, M, Action). extend(Goal, N, GoalEx) :- callable(Goal), Goal =.. List, length(Extra, N), append(List, Extra, ListEx), GoalEx =.. ListEx. %% check_options(:Predicate, +OptionArg, +Options, +ArgPos, +Action) % % Verify the list Options, that is passed into Predicate on % argument OptionArg. ArgPos is a term-position term describing % the location of the Options list. If Options is a partial list, % the tail is annotated with pass_to(PI, OptArg). check_options(PI, OptArg, QOptions, ArgPos, Action) :- debug(predicate_options, '\tChecking call to ~q', [PI]), remove_qualifier(QOptions, Options), must_be(list_or_partial_list, Options), check_option_list(Options, PI, OptArg, Options, ArgPos, Action). remove_qualifier(X, X) :- var(X), !. remove_qualifier(_:X, X) :- !. remove_qualifier(X, X). check_option_list(Var, PI, OptArg, _, _, _) :- var(Var), !, annotate(Var, pass_to(PI, OptArg)). check_option_list([], _, _, _, _, _). check_option_list([H|T], PI, OptArg, Options, ArgPos, Action) :- check_option(PI, OptArg, H, ArgPos, Action), check_option_list(T, PI, OptArg, Options, ArgPos, Action). check_option(_, _, _, _, decl) :- !. check_option(PI, OptArg, Opt, ArgPos, _) :- catch(check_predicate_option(PI, OptArg, Opt), E, true), !, ( var(E) -> true ; E = error(Formal,_), throw(error(Formal,ArgPos)) ). /******************************* * ANNOTATIONS * *******************************/ %% annotate(+Var, +Term) is det. % % Use constraints to accumulate annotations about variables. If % two annotated variables are unified, the attributes are joined. annotate(Var, Term) :- ( get_attr(Var, predopts_analysis, Old) -> put_attr(Var, predopts_analysis, [Term|Old]) ; var(Var) -> put_attr(Var, predopts_analysis, [Term]) ; true ). annotations(Var, Annotations) :- get_attr(Var, predopts_analysis, Annotations). predopts_analysis:attr_unify_hook(Opts, Value) :- get_attr(Value, predopts_analysis, Others), !, append(Opts, Others, All), put_attr(Value, predopts_analysis, All). predopts_analysis:attr_unify_hook(_, _). /******************************* * PARTIAL EVAL * *******************************/ eval_option_pred(swi_option:option(Opt, Options)) :- processes(Opt, Spec), annotate(Options, Spec). eval_option_pred(swi_option:option(Opt, Options, _Default)) :- processes(Opt, Spec), annotate(Options, Spec). eval_option_pred(swi_option:select_option(Opt, Options, Rest)) :- ignore(unify_with_occurs_check(Rest, Options)), processes(Opt, Spec), annotate(Options, Spec). eval_option_pred(swi_option:select_option(Opt, Options, Rest, _Default)) :- ignore(unify_with_occurs_check(Rest, Options)), processes(Opt, Spec), annotate(Options, Spec). eval_option_pred(swi_option:meta_options(_Cond, QOptionsIn, QOptionsOut)) :- remove_qualifier(QOptionsIn, OptionsIn), remove_qualifier(QOptionsOut, OptionsOut), ignore(unify_with_occurs_check(OptionsIn, OptionsOut)). processes(Opt, Spec) :- compound(Opt), functor(Opt, OptName, 1), Spec =.. [OptName,any]. /******************************* * NEW DECLARTIONS * *******************************/ %% option_decl(:Head, +Action) is det. % % Add new declarations based on attributes left by the analysis % pass. We do not add declarations for system modules or modules % that already contain static declarations. % % @tbd Should we add a mode to include generating declarations % for system modules and modules with static declarations? option_decl(_, check) :- !. option_decl(M:_, _) :- system_module(M), !. option_decl(M:_, _) :- has_static_option_decl(M), !. option_decl(M:Head, _) :- arg(AP, Head, QA), remove_qualifier(QA, A), annotations(A, Annotations0), functor(Head, Name, Arity), PI = M:Name/Arity, delete(Annotations0, pass_to(PI,AP), Annotations), Annotations \== [], Decl = predicate_options(PI, AP, Annotations), ( new_decl(Decl) -> true ; assert_predicate_options(M:Name/Arity, AP, Annotations, false) -> true ; assertz(new_decl(Decl)), debug(predicate_options(decl), '~q', [Decl]) ), fail. option_decl(_, _). system_module(system) :- !. system_module(Module) :- sub_atom(Module, 0, _, _, $). /******************************* * MISC * *******************************/ canonical_pi(M:Name//Arity, M:Name/PArity) :- integer(Arity), PArity is Arity+2. canonical_pi(PI, PI). %% resolve_module(:PI, -DefPI) is det. % % Find the real predicate indicator pointing to the definition % module of PI. This is similar to using predicate_property/3 with % the property imported_from, but using % '$get_predicate_attribute'/3 avoids auto-importing the % predicate. resolve_module(Module:Name/Arity, DefM:Name/Arity) :- functor(Head, Name, Arity), ( '$get_predicate_attribute'(Module:Head, imported, M) -> DefM = M ; DefM = Module ). /******************************* * MESSAGES * *******************************/ :- multifile prolog:message//1. prolog:message(predicate_option_error(Formal, Location)) --> error_location(Location), '$messages':term_message(Formal). % TBD: clean interface prolog:message(check_options(new(Decls))) --> [ 'Inferred declarations:'-[], nl ], new_decls(Decls). error_location(file_char_count(File, CharPos)) --> { filepos_line(File, CharPos, Line, LinePos) }, [ '~w:~d:~d: '-[File, Line, LinePos] ]. error_location(clause(ClauseRef)) --> { clause_property(ClauseRef, file(File)), clause_property(ClauseRef, line_count(Line)) }, !, [ '~w:~d: '-[File, Line] ]. error_location(clause(ClauseRef)) --> [ 'Clause ~q: '-[ClauseRef] ]. filepos_line(File, CharPos, Line, LinePos) :- setup_call_cleanup( ( open(File, read, In), open_null_stream(Out) ), ( Skip is CharPos-1, copy_stream_data(In, Out, Skip), stream_property(In, position(Pos)), stream_position_data(line_count, Pos, Line), stream_position_data(line_position, Pos, LinePos) ), ( close(Out), close(In) )). new_decls([]) --> []. new_decls([H|T]) --> [ ' :- ~q'-[H], nl ], new_decls(T). /******************************* * SYSTEM DECLARATIONS * *******************************/ :- use_module(library(dialect/swi/syspred_options)).