:- style_check(all).

:- use_module(library(readutil)).
:- use_module(library(lineutils)).
:- use_module(library(lists)).
:- use_module(library(maplist)).
:- use_module(library(system)).

:- initialization(main).

:- yap_flag( double_quotes, string ).

:- dynamic edge/1,
   public/2,
   private/2,
   module_on/3,
   exported/1, 
   dir/2,
   consulted/2,
   op_export/3.
   library/1.

% @short node(?Module:module, ?Predicate:pred_indicator, ?File:file, ?Generator:atom) is nondet
%


inline( !/0 ).
inline( (\+)/1 ).
inline( (fail)/0 ).
inline( (false)/0 ).
inline( (repeat)/0 ).
inline( (true)/0 ).
inline( []/0 ).

% @short edge(+SourceModule:module, +SourcePredicate:pred_indicator, +TargetPredicate:pred_indicator, +InFile:file) is nondet
%

main :-
     init,
    fail.
main :-
      unix(argv([D])),
      working_directory(_, D),
      fail.
main :-
      % from libraries outside the current directories
      assert( node( attributes, woken_att_do/4, 'library/atts.yap', prolog ) ),
     fail.
main :-
    Dirs = ['C'-prolog,
	    'os'-prolog,
	    'pl'-prolog,
	    'OPTYap'-prolog,
	    'library'-user,
	    'swi/console'-prolog,
	    'swi/library'-user,
	    'packages'-user],
    dirs( Dirs ),
    ops_default,
    %%% phase 1: find modules
    nb_setval( current_module, user ),
    nb_setval( private, false ),
    init_loop( Dirs ),
    maplist( pl_interfs, Dirs ),
    %%% phase 2: find C-code predicates
    maplist( c_preds, Dirs ),
    %%% phase 4: construct graph
    retractall( consulted(_,_) ),
    maplist( pl_graphs, Dirs ),
    undefs,
    doubles,
    %     pl_exported(pl).
    c_links.


dirs( Roots ) :-
    member( Root-_, Roots ),
    directory_files( Root , Files),
    member(  File, Files ),
    atom_concat( [Root,'/',File], New ),
    (
	file_property( New, type(directory) ),
	File \= '.',
	File \= '..',
	File \= '.git',
	subdir( New )
    ;
        assert_new( dir( Root, File ))
    ),
    fail.
dirs(_).

subdir( Root ) :-
    directory_files( Root , Files),
    member(  File, Files ),
    atom_concat( [Root,'/',File], New ),
    (
	file_property( New, type(directory) ),
	File \= '.',
	File \= '..',
	File \= '.git',
	subdir( New )
    ;
        assert_new( dir( Root, File ))
    ),
    fail.


init :-
    ops_default,
    retractall(dir(_)),
    retractall(edge(_)),
    retractall(private(_,_)),
    retractall(public(_,_)),
    retractall(consulted(_,_)),
    retractall(module_on(_,_,_)),
    retractall(op_export(_,_,_)),
    retractall(exported(_)).

init_loop( _Dirs ).

c_preds(Dir - Mod) :-
    atom( Dir ),
    atom_concat([Dir,'/*'], Pattern),
    expand_file_name( Pattern, Files ),
    member( File, Files ),
    ( ( sub_atom(File,_,_,0,'.c') ; sub_atom(File,_,_,0,'.cpp') ) ->
	  c_file( File , Mod )
    ;
         exists_directory( File ),
         \+ atom_concat(_, '/.', File),
         \+ atom_concat(_, '/..', File),
         c_preds( File - Mod )
    ),
    fail.
c_preds(_).


c_file(F, Mod) :-
%    wrixbteln(F),
    nb_setval( current_module, Mod ),
    open(F, read, S, [alias(c_file)]),
    repeat,
    read_line_to_string( S, String ),
    ( String == end_of_file
      ->
	  !,
	  close(S)
      ;
      split_string(String, ",; ()\t\"\'", Fields),
%writeln(Fields),
      line_count(S, Lines),
      c_line(Fields , Mod, F:Lines),
      fail
    ).

c_line(["}"], Mod, _) :- !,
     nb_setval( current_module, Mod ).
c_line(Line, _Mod, _) :- 
     append( _, [ "CurrentModule", "=", M|_], Line),
     system_mod(M, _Mod, Mod),
     nb_setval( current_module, Mod ).
c_line(Line, Mod, F:_Line) :- 
    break_line( Line, N/A, Fu),
    handle_pred( Mod, N, A, F ),
    assert( foreign( Mod:N/A, Fu ) ).

break_line( Line, N/A, c(Fu)) :-
    take_line( Line, NS, AS, FS ), !,
    atom_string(N,NS),
    atom_string(Fu,FS),
    number_string(A, AS).
break_line( Line, N/A, swi(Fu)) :-
    take_line( Line, NS, AS, FS ), !,
    atom_string(N,NS),
    number_string(A, AS),
    atomic_concat(["pl_",FS,"_",A,"_va"], Fu).
break_line( Line, N/A, bp(Fu)) :-
    take_line( Line, NS, AS, FS ), !,
    atom_string(N,NS),
    number_string(A, AS),
    atomic_concat(["pc_",FS,"_",A], Fu).
break_line( Line, N/A, c(FuE, FuB)) :-
    take_line( Line, NS, AS, FSE, FSB ), !,
    atom_string(N,NS),
    atom_string(FuE,FSE),
    atom_string(FuB,FSB),
    number_string(A, AS).
    
take_line( Line, NS, AS, FS ) :-
     append( _, [ "Yap_InitCPred", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "Yap_InitAsmPred", NS, AS, _, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "Yap_InitCmpPred", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "Yap_InitCmpPred", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "YAP_UserCPredicate", NS, FS, AS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "PRED", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "PRED_IMPL", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "PRED_DEF", NS, AS, FS|_], Line), !.
take_line( Line, NS, AS, FS ) :-
     append( _, [ "FRG", NS, AS, FS|_], Line), !.


take_line( Line,  AS, FS ) :-
     append( _, [ "REGISTER_CPRED", FS, AS], Line), !.


take_line( Line, NS, AS, FSE, FSB ) :-
     append( _, [ "Yap_InitCPredBack", NS, AS, _, FSE, FSB|_], Line), !.

system_mod("ATTRIBUTES_MODULE", _, attributes ).
system_mod("HACKS_MODULE", _, '$hacks' ).
system_mod("USER_MODULE", _, user ).
system_mod("DBLOAD_MODULE", xs, '$db_load' ).
system_mod("GLOBALS_MODULE", _, globals ).
system_mod("ARG_MODULE", _, arg  ).
system_mod("PROLOG_MODULE", _ , prolog ).
system_mod("RANGE_MODULE", _, range ).
system_mod("SWI_MODULE", _, swi ).
system_mod("OPERATING_SYSTEM_MODULE", _, operating_system_support  ).
system_mod("TERMS_MODULE", _, terms ).
system_mod("SYSTEM_MODULE", _, system ).
system_mod("IDB_MODULE", _, idb ).
system_mod("CHARSIO_MODULE", _, charsio ).
system_mod("cm", M, M ).


pl_interfs(Dir - Mod) :-
    format(' ************* MOD: ~a ***********************\n', [Dir]),
    atom( Dir ),
    directory_files( Dir , Files),
    member( File, Files ),
    File \= '.', % don't loop
    File \= '..', % don't go up
    File \= '.git', % don't go up
    atom_concat([Dir,'/',File], Path),
    ( ( sub_atom(File,_,_,0,'.yap') ; sub_atom(File,_,_,0,'.pl') ) ->
	  ops_restore,
	 pl_interf( Path , Mod )
    ;
         file_property( Path, type(directory) ),
	 pl_interfs( Path - Mod )
    ),
    fail.
pl_interfs(_).

%%
% pl_interf( File, Mod)
% adds a node to the file graph and marks which files are modules
%
% main side-effect facts like edge( F0-Mod:File )
%                             exported( ( FMNATarget :- FMNASource ) ) ou exported(F-M, Op ),
%                             module_on ( M, File ) 
%
pl_interf(F, _Mod) :-
    consulted(F, _M ), 
    !.
pl_interf(F, Mod) :-
    writeln(F),
%	  ( sub_atom(F,_,_,_,'clpfd.pl') -> spy get_interf ; true ), 
    ops_restore,
    assert_new(consulted(F, Mod ) ), 
    nb_getval( private, Default ),
    nb_setval( private, false ),
    catch( open(F, read, S, []) , _, fail ),
    repeat,
    nb_getval( current_module, MR ),
    catch( read_term( S, T, [module( MR )] ), Throw, (writeln(F:MR:Throw), break, fail)),
    ( 
	T == end_of_file
	->
	    !,
	    % also, clo ops defined in the module M, if M \= Mod
	    generate_interface( F, Mod ),
	    nb_setval( current_module, Mod ),
	    nb_setval( private, Default ),
	    close(S)
	;
	nb_getval( current_module, MC0 ),
	( Mod == prolog -> MC = prolog ; MC = MC0 ),
	get_interf( T, F, MC  ),
	fail
    ).

get_interf( T, _F, _M0 ) :- 
    var(T), 
    !. 
get_interf( T, _F, _M0 ) :-
%    ( T = (:- op(_,_,_)) -> trace ; true ),
    var(T), 
    !. 
get_interf( M:T, F, _M0 ) :- !,
    get_interf( T, F, M ). 
get_interf( ( M:H :- _B), F, _M ) :- 
    !,
    get_interf( H, F, M ).
get_interf( ( M:H --> _B), F, _ ) :- 
    !,
    get_interf( ( H --> _B), F, M ).
get_interf( ( A, _ --> _B), F, M ) :- 
    get_interf( ( A --> _B), F, M ).
get_interf( (H --> _B), F, M ) :-
    !,
    functor( H, N, Ar),
    Ar2 is Ar+2,
    functor( H2, N, Ar2),
    get_interf( H2, F, M ).
get_interf( (H :- _B), F, M ) :-
    !,
    get_interf( H, F, M ).
%% switches to new file n
get_interf( (:- V ), _F, _M ) :-
    var( V ),
    !.
get_interf( (:- module( NM, Is ) ), F, _M ) :-
    !,
    nb_setval( current_module, NM ),
    assert( module_on( F , NM, Is) ),
    maplist( public(F, NM), Is ),
    nb_setval( private, true ). 
get_interf( (:- reexport( Loc, Is ) ), F, M ) :- 
    !,
    % find the file
    search_file( Loc, F, NF ),
    % depth visit
    pl_interf(NF, M), % should verify Is in _Is
    % link bdd
    module_on( NF, NM, _ ),
    maplist( exported( NF, F, NM, M) , Is ),
    maplist( public(F, NM), Is ).
get_interf( (:- use_module( Loc, Is ) ), F, M ) :- !,
    !,
    % find the file
    search_file( Loc, F, NF ),
    % depth visit
    pl_interf(NF, M), % should verify Is in _Is
    % link b
    module_on( NF, NM, _ ),
    maplist( exported( NF, F, NM, M) , Is ).
get_interf( (:- use_module( Loc ) ), F, M ) :- !,
    !,
    % find the file
    search_file( Loc, F, NF ),
    % depth visit
    pl_interf(NF, M), % should verify Is in _Is
    % link b
    module_on( NF, NM, Is ),
    maplist( exported( NF, F, NM, M) , Is ).
get_interf( (:- use_module( Loc, Is, _ ) ), F, M ) :- !,
    !,
    % find the file
    search_file( Loc, F, NF ),
    % depth visit
    pl_interf(NF, M), % should verify Is in _Is
    % link b
    module_on( NF, NM, _ ),
    maplist( exported( NF, F, NM, M) , Is ).
get_interf( (:- consult( Files ) ), F, M ) :- 
    !,
    include_files(  F, M, Files ).
get_interf( (:- reconsult( Files ) ), F, M ) :- 
    !,
    include_files(  F, M, Files ).
get_interf( (:- ensure_loaded( Files ) ), F, M ) :- 
    !,
    include_files(  F, M, Files ).
get_interf( (:- include( Files ) ), F, M ) :- 
    !,
    include_files(  F, M, Files ).
get_interf( (:- load_files( Files , [] ) ), F, M ) :- 
    !,
    include_files(  F, M, Files ).
get_interf( (:- [F1|Fs] ), F, M ) :- 
    !,
    include_files(  F, M, [F1|Fs] ).
% don't actually use this one.
get_interf( (:- system_module( _NM, _Publics, _Hiddens) ), _F, _M ) :- 
    !.
get_interf( (:- style_checker( _ ) ), _F, _M ) :- 
    !. 
get_interf( (:- dynamic T), F, M ) :-
    !,
    declare_functors( T, F, M ).
get_interf( (:- multifile T), F, M ) :- % public?
    !,
    declare_functors( T, F, M ).
get_interf( (:- meta_predicate T), F, M ) :-!,
    declare_terms( T, F, M ), % public?
    !.
get_interf( (:- '$install_meta_predicate'( H, M) ), F, __M ) :-
    !,
    declare_functors( H, F, M ).
get_interf( (:- thread_local _Bs), _F, _M ) :-
    !.
get_interf( (:- op( X, Y, Z) ), F, M ) :- 
    !,
    always_strip_module(M:Z, M1, Z1),
    handle_op( F, M1, op( X, Y, Z1) ).
get_interf( (:- _ ), _F, _M ) :- !.
get_interf( (?- _ ), _F, _M ) :- !.
get_interf( V , _F, _M ) :-
    var( V ),
    !,
    error( instantiation_error ).
get_interf( G , F, M ) :-
    functor( G, N, A),
    handle_pred( M, N, A, F ),
    !.


handle_pred( M, N, A, F ) :-
    (
        system_mod( _, _, M )
	->
	    (
		atom_concat('$',_,N)
		->
		    private( F, M, N/A  )
		;
		public( F, M, N/A  )
	    )
	;
	( nb_getval( private, false )
	  ->
	      public( F, M, N/A  )
	  ;
	  private( F, M, N/A  )
	)
    ).

handle_op( F, M, Op ) :-
    ( nb_getval( private, false )
      ->
	  public( F, M, Op  )
      ;
      private( F, M, Op  )
    ),
    Op = op(X, Y, Z ),
    ( ( M == user ; M == prolog )
      ->
	  op( X, Y, prolog:Z )
      ;
	  op( X, Y, M:Z )
    ).

exported( NF, F, NM, M, op(X,Y,Z)) :- 
    !,
    public( NF , NM:op(X,Y,Z) ),
    handle_op( F, M , op(X,Y,Z) ).
exported( NF, F, NM, M, N/A) :- !,
    assert_new( exported( (F-M:N/A :- NF-NM:N/A )) ).
exported( NF, F, NM, M, N/A as NN) :- !,
    assert_new( exported( ( F-M:NN/A :- NF-NM:N/A ) ) ).
exported( NF, F, NM, M, N//A) :- !,
    A2 is A+2,
    assert_new( exported( (F-M:N/A2 :- NF-NM:N/A2) ) ).
exported( NF, F, NM, M, N//A as NN) :- !,
    A2 is A+2,
    assert_new( exported( ( F-M:NN/A2 :- NF-NM:N/A2 )) ).

import_publics( F, ProducerMod, ConsumerMod ) :-
    public(F, ProducerMod:op(X,Y,Z) ),
    handle_op( F, ConsumerMod, op(X,Y,Z) ),
    fail.
import_publics( _F, _ProducerMod, _ConsumerMod ).

all_imported( ProducerFile, ConsumerFile, ProducerMod, ConsumerMod ) :-
    public(ProducerFile, ProducerMod:op(X,Y,Z) ),
    handle_op( ConsumerFile,  ConsumerMod, op(X,Y,Z) ),
    fail.
all_imported( ProducerFile, ConsumerFile, ProducerMod, ConsumerMod ) :-
    public(ProducerFile, ProducerMod:N/A ),
    exported( ProducerFile, ConsumerFile, ProducerMod, ConsumerMod, N/A ),
    fail.
all_imported( _ProducerFile, _ConsumerFile,  _ProducerMod, _ConsumerMod ).


include_files( F, M, Files ) :-
    maplist( include_files( F, M ), Files ),
    !.
include_files( F, M, -Files ) :-
    !,
    include_files(  F, M, Files).
include_files( F, M, Files ) :- 
    !,
    always_strip_module(M:Files, M1, NFiles),
    include_file( F, M1, NFiles ).
include_files( F, M, Loc ) :- 
    include_file( F, M, Loc ).

include_file( F, M, Loc ) :-
    is_list( Loc ), !,
    maplist( include_file( F, M ), Loc ).
include_file( F, M, Loc ) :-
    nb_getval( private, Private ),
    % find the file
    search_file( Loc, F, NF ),
    % depth visit
    pl_interf(NF, M), % should verify Is in _Is
    % link b
    ( module_on(NF, NM, Is)
    ->
       maplist( exported( NF, F, NM, M) , Is )
	;
	all_imported( NF, F, NM, M)
    ),
    nb_setval( private, Private ).

declare_functors( T, _F, _M1) :-  var(T), !,
    error( unbound_variable ).
declare_functors( M:T, F, _M1) :-  !,
    declare_functors( T, F, M).
declare_functors( (T1,T2), F, M1) :-  !,
    declare_functors( T1, F, M1),
    declare_functors( T2, F, M1).
declare_functors( Ts, F, M1) :-  
    maplist( declare_functor( F, M1), Ts ), !.
declare_functors( T, F, M1) :-  
    declare_functor( F, M1, T).

declare_functor(File, M, N/A) :-
    handle_pred( M, N, A, File ).

declare_terms( T, _F, _M1) :-  var(T), !,
    error( unbound_variable ).
declare_terms( M:T, F, _M1) :-  !,
    declare_functors( T, F, M).
declare_terms( (N1,N2), F, M) :- 
    number(N1),
    number(N2),
    !,
    declare_term(  F, M, (N1,N2)).
declare_terms( (T1,T2), F, M1) :-  !,
    declare_terms( T1, F, M1),
    declare_terms( T2, F, M1).
declare_terms( Ts, F, M1) :-  
    maplist( declare_term( F, M1), Ts ), !.
declare_terms( T, F, M1) :-  
    declare_term( F, M1, T).

declare_term(F, M, S) :-
    functor(S, N, A),
    handle_pred( M, N, A, F ).

% clean operators
generate_interface( _F, _M ) :-
fail,
    public( _, prolog:op(_X,Y,Z) ),
    op(0,Y,Z),
    fail.
generate_interface( _F, _M ) :-
fail,
    private( _, prolog:op(_X,Y,Z) ),
    op(0,Y,Z),
    fail.
generate_interface( _F, Mod ) :-
    nb_setval( current_module, Mod ).



pl_graphs(Dir - Mod) :-
    format(' ************* GRAPH: ~a ***********************~n', [Dir]),
    atom( Dir ),
    atom_concat([Dir,'/*'], Pattern),
    expand_file_name( Pattern, Files ),
    member( File, Files ),
    ( ( sub_atom(File,_,_,0,'.yap') ; sub_atom(File,_,_,0,'.pl') ) ->
	 pl_graph( File , Mod )
    ;
         exists_directory( File ),
         \+ atom_concat(_, '/.', File),
         \+ atom_concat(_, '/..', File),
	 pl_graphs( File - Mod )
    ),
    fail.
pl_graphs(_).

%%
% pl_graph( File, Mod)
% adds a node to the file graph and marks which files are modules
%
% main side-effect facts like edge( F0-Mod:File )
%                             exported( F-M , N/A ) ou exported(F- M. Op ),
%                             module_on ( M, File ) 
%                             pred ( M :N/A ) 
%
pl_graph(F, Mod) :-
    consulted( F, Mod), !.
pl_graph(F, Mod) :-
%    writeln(F),
    assert( consulted( F, Mod )),
    catch( open(F, read, S), _, fail ),
    repeat,
    catch( read_term( S, T, [term_position(Pos)] ), Throw, (writeln(Throw), T = end_of_file)),
    ( 
	T == end_of_file
	->
	    !,
	    % also, clo ops defined in the module M, if M \= Mod
	    pl_graph( F, Mod ),
	    nb_setval( current_module, Mod ),
	    close(S)
	;
	nb_getval( current_module, MC0 ),
	( Mod == prolog -> MC = prolog ; MC = MC0 ),
	( system_mod(_,_,MC) -> nb_setval( private, true ) ; nb_setval( private, false ) ),
	get_graph( T, F, Pos, MC  ),
	fail
    ).


get_graph( V , _F, _Pos, _M ) :-
    var( V ),
    !,
    error( instantiation_error ).
get_graph( T, _F, _Pos, _M0 ) :- 
    var(T), 
    !. 
get_graph( M:T, F, _Pos, _M0 ) :- !,
    get_graph( T, F, _Pos, M ). 
get_graph( ( M:H :- B), F, _Pos, M0 ) :- 
    !,
    get_graph( (H :- M0:B), F, _Pos, M ).
get_graph( ( M:H --> B), F, _Pos, M0 ) :- 
    !,
    get_graph( ( H --> M0:B), F, _Pos, M ).
get_graph( ( A, _ --> B), F, _Pos, M ) :- 
    get_graph( ( A --> B), F, _Pos, M ).
get_graph( (H --> B), F, _Pos, M ) :-
    !,
    functor( H, N, Ar),
    Ar2 is Ar+2,
    add_deps( B, M, M:N/Ar2, F, _Pos, 2 ).
get_graph( (H :- B), F, _Pos, M ) :-
    !,
    functor( H, N, Ar),
    add_deps( B, M, M:N/Ar, F, _Pos, 0 ).
%% switches to new file n
get_graph( (:- module(M,_)), _F, _Pos, _M ) :-
    !,
    nb_setval( current_module, M ).
get_graph( (:- _ ), _F, _Pos, _M ) :-
    !.
get_graph( (?- _ ), _F, _Pos, _M ) :- !.


add_deps(V, _M, _P, _F, _Pos, _) :- 
    var(V), !.
add_deps(M1:G, _M, _P, _F, _Pos,L) :- 
    !,
    always_strip_module(M1:G, M2, G2),
    add_deps(G2, M2, _P, _F, _Pos, L).
add_deps((A,B), M, P, F, _Pos, L) :- 
    !,
    add_deps(A, M, P, F, _Pos, L),
    add_deps(B, M, P, F, _Pos, L).
add_deps((A;B), M, P, F, _Pos, L) :- !,
    add_deps(A, M, P, F, _Pos, L),
    add_deps(B, M, P, F, _Pos, L).
add_deps((A|B), M, P, F, _Pos, L) :- !,
    add_deps(A, M, P, F, _Pos, L),
    add_deps(B, M, P, F, _Pos, L).
add_deps((A->B), M, P, F, _Pos, L) :- !,
    add_deps(A, M, P, F, _Pos, L),
    add_deps(B, M, P, F, _Pos, L).
add_deps((A*->B), M, P, F, _Pos, L) :- !,
    add_deps(A, M, P, F, _Pos, L),
    add_deps(B, M, P, F, _Pos, L).
add_deps(once(A), M, P, F, _Pos, L) :- !,
    add_deps(A, M, P, F, _Pos, L).
add_deps({A}, M, P, F, _Pos, 2) :- !,
    add_deps(A, M, P, F, _Pos, 0).
add_deps([_|_], M, P, F, Pos, 2) :- 
    !,
    put_dep( (F-M:P :- prolog:'C'/3 ), Pos ).
add_deps(String, _M, _P, _F, _Pos, _) :-  string(String), !.
add_deps([], _M, _P, _F, _Pos, 2) :- !.
add_deps(!, _M, _P, _F, _Pos, _) :- !.
add_deps(true, _M, _P, _F, _Pos, 0) :- !.
add_deps(false, _M, _P, _F, _Pos, 0) :- !.
add_deps(fail, _M, _P, _F, _Pos, 0) :- !.
add_deps(repeat, _M, _P, _F, _Pos, 0) :- !.
add_deps(A, M, P, F, Pos, L) :- !,
     % we're home, M:N/Ar -> P=M1:N1/A1
    functor(A, N, Ar0),
    Ar is Ar0+L,
    put_dep( ( F-M:P :- F-M:N/Ar ), Pos ).

put_dep( (Target :- F0-M:Goal ), _ ) :- 
    exported( ( F0-M:Goal :- F1-M1:N/Ar ) ), !,
    %follow ancestor chain
    ancestor( ( F1-M1:N/Ar :- F0-M0:N0/Ar )  ),
    assert_new( edge( (  Target :- F0-M0:N0/Ar ) ) ).
% the base case, copying from the same module ( but maybe not same file 0.
put_dep( ( Target :- _F-M:N/Ar ) , _ ) :- 
    m_exists(M:N/Ar, F0),
    !,
    assert_new( edge( ( Target :- F0-M:N/Ar ) ) ).
% prolog is visi ( but maybe not same file 0.
put_dep( ( Target :- _F-_prolog:N/Ar ), _ ) :- 
    m_exists(prolog:N/Ar, F0),
    !,
    assert_new( edge( ( Target :- F0-prolog:N/Ar ) ) ).
put_dep( ( _ :- F-Mod:N/Ar ), Pos) :-
    stream_position_data( line_count, Pos, Line ),
    format( 'UNDEF in file ~w, line ~d :- ~w:~w~n',[ F, Line,  Mod, N/Ar]) .

ancestor( ( Younger :- Older) ) :-  
    exported(  ( Mid :- Older ) ), !,
    ancestor( ( Younger :- Mid) ).
ancestor( (Older :- Older) ).

m_exists(P, F) :- private( F, P ), !.
m_exists(P, F) :- public( F, P ).

doubles :-
    node(M, P, _F, _),
    node(M1, P, _F1, _),
    M @< M1,
    is_public( P, M, _F),
    is_public( P, M1, _F1),
    format('~w vs ~w~n', [M:P,M1:P]),
    fail.
doubles.

undefs :-
    edge(_M:P,_,F),
    \+ node(_, P, _, _),
    format('UNDEFINED procedure call ~q at ~w~n',[P, F]),
    fail.
undefs.

out_list([]) :-
    format('[]', []).
out_list([El]) :-
    format('[~q]', [El]).
out_list([E1,E2|Es]) :-
    format('[~q', [E1]),
    maplist(out_el, [E2|Es]),
    format(']', []).

out_el( El ) :- 
    format(',~n        ~q',[El]).

pub(M, P) :-
    node(M, P, _, _),
    P = N/_A,
    \+ sub_atom(N,0,1,_,'$').

has_edge(M1, P1, M, F) :-
	edge(M1:P1, _P, F:_),
	node(M1, P1, _, _),
	M1 \= prolog,
	M1 \= M,
	\+ is_public(P1, M1, _).

mod_priv(M, P) :-
    node(M, P, _, _),
    node(M, P, _, _),
    \+ is_public(P, M, _),
    edge(M1:P, _P0, _), M1 \= M.

priv(M, P) :-
    node(M, P, F:_, _),
    \+ is_public(P, M, _),
    edge(_:P, _P1, F1:_), F1 \= F.

% utilities
    
split_string( S , Cs, N) :-
    string_codes(S, S1),
    string_codes(Cs, NCs),
    split(S1, NCs, Ncs0),
    maplist(remove_escapes, Ncs0, Ncs),
    maplist(string_codes, N, Ncs).

remove_escapes([0'\\ ,A|Cs], [A|NCs]) :- !, %'
    remove_escapes(Cs, NCs).
remove_escapes([A|Cs], [A|NCs]) :-
    remove_escapes(Cs, NCs).
remove_escapes( [], [] ).

always_strip_module(V, M, V1) :- var(V), !,
		V = M:call(V1).
always_strip_module(M0:A, M0, call(A)) :- var(A), !.
always_strip_module(_:M0:A, M1, B) :- !,
	always_strip_module(M0:A, M1, B).
always_strip_module(M0:A, M0, call(A)) :- var(A),!.
always_strip_module(M0:A, M0, A).

c_location( matrix, 'library/matrix').
c_location( lammpi, 'library/lammpi').
c_location( matlab, 'library/matlab').
c_location( matlab, 'library/matlab').
c_location( matlab, 'library/random').
c_location( regex, 'library/regex').
c_location( rltree, 'library/rltree').
c_location( tries, 'library/tries').
c_location( operating_system_support, 'library/system').

c_links :-
    node( M, P, _, c(F)),
    format( ':- implements( ~q , ~q ).~n', [M:P, F] ),
    fail.
c_links.

warn_singletons(_Vars, _Pos).

%%
% comment( +Comment )
%
% Handle documentation comments
% 
comment( _Pos - Comment) :- 
    skip_blanks(1, Comment, N),
    doc( Comment, N ), !,
    format( "%s\n", [Comment] ).
comment( _Pos - _Comment).

skip_blanks(I, Comment, N) :-
    get_string_code( I, Comment, Code ),
    code_type( Code, space ),
    I1 is I+1,
    skip_blanks(I1, Comment, N).
skip_blanks(N, _Comment, N).

doc( Comment , N ) :-
    N1 is N+1,
    sub_string( Comment, N1, 3, _, Header ),
    ( Header == "/**" -> true ; Header == "/*!" ), !,
    N4 is N+4,
    get_string_code( N4, Comment, Code ),
    code_type( Code, space ).
doc( Comment, N ) :-
    N1 is N+1,
    sub_string( Comment, N1, 2, _, Header ),
    ( Header == "%%" -> true ; Header == "%!" ),
    N3 is N+3,
    get_string_code( N3, Comment, Code ),
    code_type( Code, space ).


%%
% search_file( +Target, +Location, -File )
%
%
% Directories into atoms
search_file(  Loc , F, FN ) :-
    search_file0(  Loc , F, FN ), !.
search_file(  Loc , F, _FN ) :-
    format('~n~n~n###############~n~n FAILED TO FIND ~w when at  ~a~n~n###############~n~n~n', [Loc, F ]),
     fail.

search_file0( A/B, F, FN ) :- !,
    term_to_atom(A/B, AB),
    search_file( AB, F, FN ).
% libraries can be anywhere in the source.
search_file0( LibLoc, _F, FN ) :-
    LibLoc =.. [Dir,File], 
    term_to_atom( Dir/File, Full ),
    !,
    %but we try two choices: look for library/ 
    %
    search_file( Full, Dir, FN ),
    !.
%try to use your base
search_file0(  Loc , _F, FN ) :- 
    file_base_name( Loc, Loc0),
    Loc \= Loc0, !, % you *have* to check the key
    check_suffix( Loc0, Loc1 ), 
    file_directory_name( Loc, LocD),
    match_file( LocD, Loc1, FN ),
    !.
% you try using the parent
search_file0(  Loc , F, FN ) :- 
    file_directory_name( F, FD),
    '' \= FD, % no point here
    file_base_name( Loc, Loc0),
    check_suffix( Loc0, Loc1 ),
    match_file(FD, Loc1, FN ),
    !.
% everything goes
search_file0(  Loc , _F, FN ) :- 
    file_base_name( Loc, Loc0),
    check_suffix( Loc0, Loc1 ),
    match_file( _LocD, Loc1, FN ),
    !.

% files must be called .yap or .pl
% if it is .yap...
check_suffix(  Loc , Loc ) :- 
    atom_concat( _, '.yap', Loc ), !.
%, otherwise, .pl
check_suffix(  Loc , Loc ) :- 
    atom_concat( _, '.pl', Loc ), !.
%, otherwise, .prolog
check_suffix(  Loc , Loc ) :- 
    atom_concat( _, '.prolog', Loc ), !.
%, otherwise, .P
% try adding suffix
check_suffix(  Loc0 , Loc ) :- 
    member( Suf , ['.yap', '.pl' , '.prolog']), 
    atom_concat( Loc0, Suf, Loc ).


 
match_file( LocD, Loc0, FN ) :-  var(LocD), !,
	dir( LocD, Loc0 ),
	atom_concat( [LocD, '/', Loc0], FN ).
match_file( SufLocD, Loc0, FN ) :- 
	dir( LocD, Loc0 ),
	atom_concat(_, SufLocD, LocD ),
	atom_concat( [LocD, '/', Loc0], FN ).

 
new_op( F, M, op(X,Y,Z) ) :-
    nb_getval( private, true ),
    !,
    private( F, M, op(X,Y,Z) ),
    op( X, Y, Z).
new_op( F, M, op( X, Y, Z) ) :-
    public( F, M, op( X, Y, Z) ).


%%%%%%%
%% declare a concept exportable
public( F, M, op(X,Y,Z) ) :-
    retract( private( F, M:op(X,Y,Z) ) ),
    fail.
public( F, M, op(X,Y,Z) ) :- !,
    assert( op_export(F, _M, op(X,Y,Z) ) ),
    assert_new( public( F, M:op(X,Y,Z) ) ),
    ( 
	( M == user ; M == prolog )
      ->
	  op( X, Y, prolog:Z )
      ;
	  op( X, Y, M:Z )
    ).
public( F, M, M:N/Ar ) :-
    retract( private( F, M:N/Ar ) ),
    fail.
public( F, M, N/Ar ) :-
    assert_new( public( F, M:N/Ar ) ).

private( F, M, op(X,Y,Z) ) :- 
    !,
    assert_new( private( F, M:op(X,Y,Z) ) ),
    ( 
	( M == user ; M == prolog )
      ->
	  op( X, Y, prolog:Z )
      ;
	  op( X, Y, M:Z )
    ).
private( F, M, N/Ar ) :-
    assert_new( private( F, M:N/Ar ) ).

is_public( F, M, OP ) :-
    public( F, M:OP ).

is_private( F, M, OP ) :-
     private( F, M :OP ).

assert_new( G ) :- G, !.
assert_new( G ) :- assert( G ).

error( Error ) :- throw(Error ).

ops_default :-
    A = (_,_), functor(A,Comma,2),
    findall(op(X,Y,prolog:Z), ( current_op(X,Y,prolog:Z), Z\= Comma ), L),
    assert_static( default_ops(L) ).

ops_restore :-
    A = (_,_), functor(A,Comma,2),
    current_op(_X,Y,prolog:Z), 
    Z\= Comma,
    op(0,Y,prolog:Z),
    fail.
ops_restore :-
    default_ops(L),
    maplist( call, L ).