1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 1985-2020, University of Amsterdam 7 VU University Amsterdam 8 CWI, Amsterdam 9 All rights reserved. 10 11 Redistribution and use in source and binary forms, with or without 12 modification, are permitted provided that the following conditions 13 are met: 14 15 1. Redistributions of source code must retain the above copyright 16 notice, this list of conditions and the following disclaimer. 17 18 2. Redistributions in binary form must reproduce the above copyright 19 notice, this list of conditions and the following disclaimer in 20 the documentation and/or other materials provided with the 21 distribution. 22 23 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 29 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 31 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 33 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 POSSIBILITY OF SUCH DAMAGE. 35*/ 36 37:- module('$autoload', 38 [ '$find_library'/5, 39 '$in_library'/3, 40 '$define_predicate'/1, 41 '$update_library_index'/0, 42 '$autoload'/1, 43 44 make_library_index/1, 45 make_library_index/2, 46 reload_library_index/0, 47 autoload_path/1, 48 49 autoload/1, % +File 50 autoload/2, % +File, +Imports 51 52 require/1 % +Predicates 53 ]). 54 55:- meta_predicate 56 '$autoload'(), 57 autoload(), 58 autoload(, ), 59 require(). 60 61:- dynamic 62 library_index/3, % Head x Module x Path 63 autoload_directories/1, % List 64 index_checked_at/1. % Time 65:- volatile 66 library_index/3, 67 autoload_directories/1, 68 index_checked_at/1. 69 70user:file_search_path(autoload, swi(library)). 71user:file_search_path(autoload, pce(prolog/lib)). 72user:file_search_path(autoload, app_config(lib)).
83'$find_library'(Module, Name, Arity, LoadModule, Library) :-
84 load_library_index(Name, Arity),
85 functor(Head, Name, Arity),
86 ( library_index(Head, Module, Library),
87 LoadModule = Module
88 ; library_index(Head, LoadModule, Library)
89 ),
90 !.97'$in_library'(Name, Arity, Path) :- 98 atom(Name), integer(Arity), 99 !, 100 load_library_index(Name, Arity), 101 functor(Head, Name, Arity), 102 library_index(Head, _, Path). 103'$in_library'(Name, Arity, Path) :- 104 load_library_index(Name, Arity), 105 library_index(Head, _, Path), 106 functor(Head, Name, Arity).
113:- meta_predicate 114 '$define_predicate'(). 115 116'$define_predicate'(Head) :- 117 '$defined_predicate'(Head), 118 !. 119'$define_predicate'(Term) :- 120 Term = Module:Head, 121 ( compound(Head) 122 -> compound_name_arity(Head, Name, Arity) 123 ; Name = Head, Arity = 0 124 ), 125 '$undefined_procedure'(Module, Name, Arity, retry). 126 127 128 /******************************** 129 * UPDATE INDEX * 130 ********************************/ 131 132:- thread_local 133 silent/0.
142'$update_library_index' :- 143 setof(Dir, writable_indexed_directory(Dir), Dirs), 144 !, 145 setup_call_cleanup( 146 asserta(silent, Ref), 147 guarded_make_library_index(Dirs), 148 erase(Ref)), 149 ( flag('$modified_index', true, false) 150 -> reload_library_index 151 ; true 152 ). 153'$update_library_index'. 154 155guarded_make_library_index([]). 156guarded_make_library_index([Dir|Dirs]) :- 157 ( catch(make_library_index(Dir), E, 158 print_message(error, E)) 159 -> true 160 ; print_message(warning, goal_failed(make_library_index(Dir))) 161 ), 162 guarded_make_library_index(Dirs).
169writable_indexed_directory(Dir) :- 170 index_file_name(IndexFile, autoload('INDEX'), [access([read,write])]), 171 file_directory_name(IndexFile, Dir). 172writable_indexed_directory(Dir) :- 173 absolute_file_name(library('MKINDEX'), 174 [ file_type(prolog), 175 access(read), 176 solutions(all), 177 file_errors(fail) 178 ], MkIndexFile), 179 file_directory_name(MkIndexFile, Dir), 180 plfile_in_dir(Dir, 'INDEX', _, IndexFile), 181 access_file(IndexFile, write). 182 183 184 /******************************** 185 * LOAD INDEX * 186 ********************************/
192reload_library_index :- 193 context_module(M), 194 reload_library_index(M). 195 196reload_library_index(M) :- 197 with_mutex('$autoload', clear_library_index(M)). 198 199clear_library_index(M) :- 200 retractall(M:library_index(_, _, _)), 201 retractall(M:autoload_directories(_)), 202 retractall(M:index_checked_at(_)).
212:- meta_predicate load_library_index(, , ). 213:- public load_library_index/3. 214 215load_library_index(Name, Arity) :- 216 load_library_index(Name, Arity, autoload('INDEX')). 217 218load_library_index(Name, Arity, M:_Spec) :- 219 atom(Name), integer(Arity), 220 functor(Head, Name, Arity), 221 M:library_index(Head, _, _), 222 !. 223load_library_index(_, _, Spec) :- 224 notrace(with_mutex('$autoload', load_library_index_p(Spec))). 225 226load_library_index_p(M:_) :- 227 M:index_checked_at(Time), 228 get_time(Now), 229 Now-Time < 60, 230 !. 231load_library_index_p(M:Spec) :- 232 findall(Index, index_file_name(Index, Spec, [access(read)]), List0), 233 '$list_to_set'(List0, List), 234 retractall(M:index_checked_at(_)), 235 get_time(Now), 236 assert(M:index_checked_at(Now)), 237 ( M:autoload_directories(List) 238 -> true 239 ; retractall(M:library_index(_, _, _)), 240 retractall(M:autoload_directories(_)), 241 read_index(List, M), 242 assert(M:autoload_directories(List)) 243 ).
autoload.
253index_file_name(IndexFile, FileSpec, Options) :- 254 absolute_file_name(FileSpec, 255 IndexFile, 256 [ file_type(prolog), 257 solutions(all), 258 file_errors(fail) 259 | Options 260 ]). 261 262read_index([], _) :- !. 263read_index([H|T], M) :- 264 !, 265 read_index(H, M), 266 read_index(T, M). 267read_index(Index, M) :- 268 print_message(silent, autoload(read_index(Dir))), 269 file_directory_name(Index, Dir), 270 setup_call_cleanup( 271 '$push_input_context'(autoload_index), 272 setup_call_cleanup( 273 open(Index, read, In), 274 read_index_from_stream(Dir, In, M), 275 close(In)), 276 '$pop_input_context'). 277 278read_index_from_stream(Dir, In, M) :- 279 repeat, 280 read(In, Term), 281 assert_index(Term, Dir, M), 282 !. 283 284assert_index(end_of_file, _, _) :- !. 285assert_index(index(Name, Arity, Module, File), Dir, M) :- 286 !, 287 functor(Head, Name, Arity), 288 atomic_list_concat([Dir, '/', File], Path), 289 assertz(M:library_index(Head, Module, Path)), 290 fail. 291assert_index(Term, Dir, _) :- 292 print_message(error, illegal_autoload_index(Dir, Term)), 293 fail. 294 295 296 /******************************** 297 * CREATE INDEX.pl * 298 ********************************/
INDEX.pl. In Dir contains a file
MKINDEX.pl, this file is loaded and we assume that the index is
created by directives that appearin this file. Otherwise, all
source files are scanned for their module-header and all
exported predicates are added to the autoload index.
311make_library_index(Dir0) :- 312 forall(absolute_file_name(Dir0, Dir, 313 [ expand(true), 314 file_type(directory), 315 file_errors(fail), 316 solutions(all) 317 ]), 318 make_library_index2(Dir)). 319 320make_library_index2(Dir) :- 321 plfile_in_dir(Dir, 'MKINDEX', _MkIndex, AbsMkIndex), 322 access_file(AbsMkIndex, read), 323 !, 324 load_files(user:AbsMkIndex, [silent(true)]). 325make_library_index2(Dir) :- 326 findall(Pattern, source_file_pattern(Pattern), PatternList), 327 make_library_index2(Dir, PatternList).
INDEX.pl for Dir by scanning all files
that match any of the file-patterns in Patterns. Typically, this
appears as a directive in MKINDEX.pl. For example:
:- prolog_load_context(directory, Dir), make_library_index(Dir, ['*.pl']).
342make_library_index(Dir0, Patterns) :- 343 forall(absolute_file_name(Dir0, Dir, 344 [ expand(true), 345 file_type(directory), 346 file_errors(fail), 347 solutions(all) 348 ]), 349 make_library_index2(Dir, Patterns)). 350 351make_library_index2(Dir, Patterns) :- 352 plfile_in_dir(Dir, 'INDEX', _Index, AbsIndex), 353 ensure_slash(Dir, DirS), 354 pattern_files(Patterns, DirS, Files), 355 ( library_index_out_of_date(Dir, AbsIndex, Files) 356 -> do_make_library_index(AbsIndex, DirS, Files), 357 flag('$modified_index', _, true) 358 ; true 359 ). 360 361ensure_slash(Dir, DirS) :- 362 ( sub_atom(Dir, _, _, 0, /) 363 -> DirS = Dir 364 ; atom_concat(Dir, /, DirS) 365 ). 366 367source_file_pattern(Pattern) :- 368 user:prolog_file_type(PlExt, prolog), 369 PlExt \== qlf, 370 atom_concat('*.', PlExt, Pattern). 371 372plfile_in_dir(Dir, Base, PlBase, File) :- 373 file_name_extension(Base, pl, PlBase), 374 atomic_list_concat([Dir, '/', PlBase], File). 375 376pattern_files([], _, []). 377pattern_files([H|T], DirS, Files) :- 378 atom_concat(DirS, H, P0), 379 expand_file_name(P0, Files0), 380 '$append'(Files0, Rest, Files), 381 pattern_files(T, DirS, Rest). 382 383library_index_out_of_date(_Dir, Index, _Files) :- 384 \+ exists_file(Index), 385 !. 386library_index_out_of_date(Dir, Index, Files) :- 387 time_file(Index, IndexTime), 388 ( time_file(Dir, DotTime), 389 DotTime > IndexTime 390 ; '$member'(File, Files), 391 time_file(File, FileTime), 392 FileTime > IndexTime 393 ), 394 !. 395 396 397do_make_library_index(Index, Dir, Files) :- 398 ensure_slash(Dir, DirS), 399 '$stage_file'(Index, StagedIndex), 400 setup_call_catcher_cleanup( 401 open(StagedIndex, write, Out), 402 ( print_message(informational, make(library_index(Dir))), 403 index_header(Out), 404 index_files(Files, DirS, Out) 405 ), 406 Catcher, 407 install_index(Out, Catcher, StagedIndex, Index)). 408 409install_index(Out, Catcher, StagedIndex, Index) :- 410 catch(close(Out), Error, true), 411 ( silent 412 -> OnError = silent 413 ; OnError = error 414 ), 415 ( var(Error) 416 -> TheCatcher = Catcher 417 ; TheCatcher = exception(Error) 418 ), 419 '$install_staged_file'(TheCatcher, StagedIndex, Index, OnError).
425index_files([], _, _). 426index_files([File|Files], DirS, Fd) :- 427 catch(setup_call_cleanup( 428 open(File, read, In), 429 read(In, Term), 430 close(In)), 431 E, print_message(warning, E)), 432 ( Term = (:- module(Module, Public)), 433 is_list(Public) 434 -> atom_concat(DirS, Local, File), 435 file_name_extension(Base, _, Local), 436 forall(public_predicate(Public, Name/Arity), 437 format(Fd, 'index((~k), ~k, ~k, ~k).~n', 438 [Name, Arity, Module, Base])) 439 ; true 440 ), 441 index_files(Files, DirS, Fd). 442 443public_predicate(Public, PI) :- 444 '$member'(PI0, Public), 445 canonical_pi(PI0, PI). 446 447canonical_pi(Var, _) :- 448 var(Var), !, fail. 449canonical_pi(Name/Arity, Name/Arity). 450canonical_pi(Name//A0, Name/Arity) :- 451 Arity is A0 + 2. 452 453 454index_header(Fd):- 455 format(Fd, '/* Creator: make/0~n~n', []), 456 format(Fd, ' Purpose: Provide index for autoload~n', []), 457 format(Fd, '*/~n~n', []). 458 459 460 /******************************* 461 * EXTENDING * 462 *******************************/
autoload and reloads the library
index. For example:
:- autoload_path(library(http)).
If this call appears as a directive, it is term-expanded into a clause for file_search_path/2 and a directive calling reload_library_index/0. This keeps source information and allows for removing this directive.
479autoload_path(Alias) :- 480 ( user:file_search_path(autoload, Alias) 481 -> true 482 ; assertz(user:file_search_path(autoload, Alias)), 483 reload_library_index 484 ). 485 486systemterm_expansion((:- autoload_path(Alias)), 487 [ user:file_search_path(autoload, Alias), 488 (:- reload_library_index) 489 ]). 490 491 492 /******************************* 493 * RUNTIME AUTOLOADER * 494 *******************************/
current_prolog_flag(autoload, true) holds.504'$autoload'(PI) :- 505 source_location(File, _Line), 506 !, 507 setup_call_cleanup( 508 '$start_aux'(File, Context), 509 '$autoload2'(PI), 510 '$end_aux'(File, Context)). 511'$autoload'(PI) :- 512 '$autoload2'(PI). 513 514'$autoload2'(PI) :- 515 autoload_from(PI, LoadModule, FullFile), 516 do_autoload(FullFile, PI, LoadModule).
523autoload_from(Module:PI, LoadModule, FullFile) :- 524 autoload_in(Module, explicit), 525 current_autoload(Module:File, Ctx, import(Imports)), 526 memberchk(PI, Imports), 527 library_info(File, Ctx, FullFile, LoadModule, Exports), 528 ( pi_in_exports(PI, Exports) 529 -> ! 530 ; autoload_error(Ctx, not_exported(PI, File, FullFile, Exports)), 531 fail 532 ). 533autoload_from(Module:Name/Arity, LoadModule, FullFile) :- 534 autoload_in(Module, explicit), 535 PI = Name/Arity, 536 current_autoload(Module:File, Ctx, all), 537 library_info(File, Ctx, FullFile, LoadModule, Exports), 538 pi_in_exports(PI, Exports). 539autoload_from(Module:Name/Arity, LoadModule, Library) :- 540 autoload_in(Module, general), 541 '$find_library'(Module, Name, Arity, LoadModule, Library). 542 543:- public autoload_in/2. % used in syspred 544 545autoload_in(Module, How) :- 546 current_prolog_flag(autoload, AutoLoad), 547 autoload_in(AutoLoad, How, Module), 548 !.
552autoload_in(true, _, _). 553autoload_in(explicit, explicit, _). 554autoload_in(explicit_or_user, explicit, _). 555autoload_in(user, explicit, user). 556autoload_in(explicit_or_user, explicit, _). 557autoload_in(user, _, user). 558autoload_in(explicit_or_user, general, user).
user. '$c_current_predicate'/2
verifies the predicate really exists, but doesn't validate
that it is defined.574do_autoload(Library, Module:Name/Arity, LoadModule) :- 575 functor(Head, Name, Arity), 576 '$update_autoload_level'([autoload(true)], Old), 577 verbose_autoload(Module:Name/Arity, Library), 578 '$compilation_mode'(OldComp, database), 579 ( Module == LoadModule 580 -> ensure_loaded(Module:Library) 581 ; ( '$c_current_predicate'(_, LoadModule:Head), 582 '$get_predicate_attribute'(LoadModule:Head, defined, 1), 583 \+ '$loading'(Library) 584 -> Module:import(LoadModule:Name/Arity) 585 ; use_module(Module:Library, [Name/Arity]) 586 ) 587 ), 588 '$set_compilation_mode'(OldComp), 589 '$set_autoload_level'(Old), 590 '$c_current_predicate'(_, Module:Head). 591 592verbose_autoload(PI, Library) :- 593 current_prolog_flag(verbose_autoload, true), 594 !, 595 set_prolog_flag(verbose_autoload, false), 596 print_message(informational, autoload(PI, Library)), 597 set_prolog_flag(verbose_autoload, true). 598verbose_autoload(PI, Library) :- 599 print_message(silent, autoload(PI, Library)).
autoload(File). The module muse be
instantiated.608:- public % used from predicate_property/2 609 autoloadable/2. 610 611autoloadable(M:Head, FullFile) :- 612 atom(M), 613 current_module(M), 614 autoload_in(M, explicit), 615 ( callable(Head) 616 -> goal_name_arity(Head, Name, Arity), 617 autoload_from(M:Name/Arity, _, FullFile) 618 ; findall((M:H)-F, autoloadable_2(M:H, F), Pairs), 619 ( '$member'(M:Head-FullFile, Pairs) 620 ; current_autoload(M:File, Ctx, all), 621 library_info(File, Ctx, FullFile, _, Exports), 622 '$member'(PI, Exports), 623 '$pi_head'(PI, Head), 624 \+ memberchk(M:Head-_, Pairs) 625 ) 626 ). 627autoloadable(M:Head, FullFile) :- 628 ( var(M) 629 -> autoload_in(any, general) 630 ; autoload_in(M, general) 631 ), 632 ( callable(Head) 633 -> goal_name_arity(Head, Name, Arity), 634 ( '$find_library'(_, Name, Arity, _, FullFile) 635 -> true 636 ) 637 ; '$in_library'(Name, Arity, autoload), 638 functor(Head, Name, Arity) 639 ). 640 641 642autoloadable_2(M:Head, FullFile) :- 643 current_autoload(M:File, Ctx, import(Imports)), 644 library_info(File, Ctx, FullFile, _LoadModule, _Exports), 645 '$member'(PI, Imports), 646 '$pi_head'(PI, Head). 647 648goal_name_arity(Head, Name, Arity) :- 649 compound(Head), 650 !, 651 compound_name_arity(Head, Name, Arity). 652goal_name_arity(Head, Head, 0).
658library_info(Spec, _, FullFile, Module, Exports) :- 659 '$resolved_source_path'(Spec, FullFile, []), 660 !, 661 ( \+ '$loading_file'(FullFile, _Queue, _LoadThread) 662 -> '$current_module'(Module, FullFile), 663 '$module_property'(Module, exports(Exports)) 664 ; library_info_from_file(FullFile, Module, Exports) 665 ). 666library_info(Spec, Context, FullFile, Module, Exports) :- 667 ( Context = (Path:_Line) 668 -> Extra = [relative_to(Path)] 669 ; Extra = [] 670 ), 671 ( absolute_file_name(Spec, FullFile, 672 [ file_type(prolog), 673 access(read), 674 file_errors(fail) 675 | Extra 676 ]) 677 -> '$register_resolved_source_path'(Spec, FullFile), 678 library_info_from_file(FullFile, Module, Exports) 679 ; autoload_error(Context, no_file(Spec)), 680 fail 681 ). 682 683 684library_info_from_file(FullFile, Module, Exports) :- 685 setup_call_cleanup( 686 '$open_source'(FullFile, In, State, [], []), 687 '$term_in_file'(In, _Read, _RLayout, Term, _TLayout, _Stream, 688 [FullFile], []), 689 '$close_source'(State, true)), 690 ( Term = (:- module(Module, Exports)) 691 -> ! 692 ; nonvar(Term), 693 skip_header(Term) 694 -> fail 695 ; throw(error(domain_error(module_file, FullFile), _)) 696 ). 697 698skip_header(begin_of_file). 699 700 701:- dynamic printed/3. 702:- volatile printed/3. 703 704autoload_error(Context, Error) :- 705 suppress(Context, Error), 706 !. 707autoload_error(Context, Error) :- 708 get_time(Now), 709 assertz(printed(Context, Error, Now)), 710 print_message(warning, error(autoload(Error), autoload(Context))). 711 712suppress(Context, Error) :- 713 printed(Context, Error, Printed), 714 get_time(Now), 715 ( Now - Printed < 1 716 -> true 717 ; retractall(printed(Context, Error, _)), 718 fail 719 ). 720 721 722 /******************************* 723 * CALLBACK * 724 *******************************/ 725 726:- public 727 set_autoload/1.
false we should materialize all registered
requests for autoloading. We must do so before disabling autoloading
as loading the files may require autoloading.736set_autoload(FlagValue) :- 737 current_prolog_flag(autoload, FlagValue), 738 !. 739set_autoload(FlagValue) :- 740 \+ autoload_in(FlagValue, explicit, any), 741 !, 742 setup_call_cleanup( 743 nb_setval('$autoload_disabling', true), 744 materialize_autoload(Count), 745 nb_delete('$autoload_disabling')), 746 print_message(informational, autoload(disabled(Count))). 747set_autoload(_). 748 749materialize_autoload(Count) :- 750 State = state(0), 751 forall(current_predicate(M:'$autoload'/3), 752 materialize_autoload(M, State)), 753 arg(1, State, Count). 754 755materialize_autoload(M, State) :- 756 ( current_autoload(M:File, Context, Import), 757 library_info(File, Context, FullFile, _LoadModule, _Exports), 758 arg(1, State, N0), 759 N is N0+1, 760 nb_setarg(1, State, N), 761 ( Import == all 762 -> verbose_autoload(M:all, FullFile), 763 use_module(M:FullFile) 764 ; Import = import(Preds) 765 -> verbose_autoload(M:Preds, FullFile), 766 use_module(M:FullFile, Preds) 767 ), 768 fail 769 ; true 770 ), 771 abolish(M:'$autoload'/3). 772 773 774 /******************************* 775 * AUTOLOAD/2 * 776 *******************************/ 777 778autoload(M:File) :- 779 ( \+ autoload_in(M, explicit) 780 ; nb_current('$autoload_disabling', true) 781 ), 782 !, 783 use_module(M:File). 784autoload(M:File) :- 785 '$must_be'(filespec, File), 786 source_context(Context), 787 retractall(M:'$autoload'(File, _, _)), 788 assert_autoload(M:'$autoload'(File, Context, all)). 789 790autoload(M:File, Imports) :- 791 ( \+ autoload_in(M, explicit) 792 ; nb_current('$autoload_disabling', true) 793 ), 794 !, 795 use_module(M:File, Imports). 796autoload(M:File, Imports0) :- 797 '$must_be'(filespec, File), 798 valid_imports(Imports0, Imports), 799 source_context(Context), 800 register_autoloads(Imports, M, File, Context), 801 ( current_autoload(M:File, _, import(Imports)) 802 -> true 803 ; assert_autoload(M:'$autoload'(File, Context, import(Imports))) 804 ). 805 806source_context(Path:Line) :- 807 source_location(Path, Line), 808 !. 809source_context(-). 810 811assert_autoload(Clause) :- 812 '$initialization_context'(Source, Ctx), 813 '$store_admin_clause2'(Clause, _Layout, Source, Ctx). 814 815valid_imports(Imports0, Imports) :- 816 '$must_be'(list, Imports0), 817 valid_import_list(Imports0, Imports). 818 819valid_import_list([], []). 820valid_import_list([H0|T0], [H|T]) :- 821 '$pi_head'(H0, Head), 822 '$pi_head'(H, Head), 823 valid_import_list(T0, T).
autoload flag on all predicates declared using autoload/2
to prevent duplicates or the user defining the same predicate.830register_autoloads([], _, _, _). 831register_autoloads([PI|T], Module, File, Context) :- 832 PI = Name/Arity, 833 functor(Head, Name, Arity), 834 ( '$get_predicate_attribute'(Module:Head, autoload, 1) 835 -> ( current_autoload(Module:_File0, _Ctx0, import(Imports)), 836 memberchk(PI, Imports) 837 -> '$permission_error'(redefine, imported_procedure, PI), 838 fail 839 ; Done = true 840 ) 841 ; '$c_current_predicate'(_, Module:Head), % no auto-import 842 '$get_predicate_attribute'(Module:Head, imported, From) 843 -> ( ( '$resolved_source_path'(File, FullFile) 844 -> true 845 ; '$resolve_source_path'(File, FullFile, []) 846 ), 847 module_property(From, file(FullFile)) 848 -> Done = true 849 ; print_message(warning, 850 autoload(already_defined(Module:PI, From))), 851 Done = true 852 ) 853 ; true 854 ), 855 ( Done == true 856 -> true 857 ; '$set_predicate_attribute'(Module:Head, autoload, 1) 858 ), 859 register_autoloads(T, Module, File, Context). 860 861pi_in_exports(PI, Exports) :- 862 '$member'(E, Exports), 863 canonical_pi(E, PI), 864 !. 865 866current_autoload(M:File, Context, Term) :- 867 '$get_predicate_attribute'(M:'$autoload'(_,_,_), defined, 1), 868 M:'$autoload'(File, Context, Term). 869 870 /******************************* 871 * REQUIRE * 872 *******************************/
879require(M:Spec) :- 880 ( is_list(Spec) 881 -> List = Spec 882 ; phrase(comma_list(Spec), List) 883 ), !, 884 require(List, M, FromLib), 885 keysort(FromLib, Sorted), 886 by_file(Sorted, Autoload), 887 forall('$member'(File-Import, Autoload), 888 autoload(M:File, Import)). 889require(_:Spec) :- 890 '$type_error'(list, Spec). 891 892require([],_, []). 893require([H|T], M, Needed) :- 894 '$pi_head'(H, Head), 895 ( '$get_predicate_attribute'(system:Head, defined, 1) 896 -> require(T, M, Needed) 897 ; '$pi_head'(Module:Name/Arity, M:Head), 898 ( '$find_library'(Module, Name, Arity, _LoadModule, Library) 899 -> Needed = [Library-H|More], 900 require(T, M, More) 901 ; print_message(error, error(existence_error(procedure, Name/Arity), _)), 902 require(T, M, Needed) 903 ) 904 ). 905 906by_file([], []). 907by_file([File-PI|T0], [Spec-[PI|PIs]|T]) :- 908 on_path(File, Spec), 909 same_file(T0, File, PIs, T1), 910 by_file(T1, T). 911 912on_path(Library, library(Base)) :- 913 file_base_name(Library, Base), 914 findall(Path, plain_source(library(Base), Path), [Library]), 915 !. 916on_path(Library, Library). 917 918plain_source(Spec, Path) :- 919 absolute_file_name(Spec, PathExt, 920 [ file_type(prolog), 921 access(read), 922 file_errors(fail), 923 solutions(all) 924 ]), 925 file_name_extension(Path, _, PathExt). 926 927same_file([File-PI|T0], File, [PI|PIs], T) :- 928 !, 929 same_file(T0, File, PIs, T). 930same_file(List, _, [], List). 931 932comma_list(Var) --> 933 { var(Var), 934 !, 935 '$instantiation_error'(Var) 936 }. 937comma_list((A,B)) --> 938 !, 939 comma_list(A), 940 comma_list(B). 941comma_list(A) --> 942 [A]