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(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 '$append'(Files0, Rest, Files), 381 pattern_files(T, DirS, Rest). 382 383library_index_out_of_date(Index, _Files) :- 384 \+ exists_file(Index), 385 !. 386library_index_out_of_date(Index, Files) :- 387 time_file(Index, IndexTime), 388 ( time_file('.', DotTime), 389 DotTime > IndexTime 390 ; '$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 '$find_library'(Module, Name, Arity, LoadModule, Library). 542 543:- public autoload_in/2. % used in syspred 544 545autoload_in(Module, How) :- 546 current_prolog_flag(autoload, AutoLoad), 547 autoload_in(AutoLoad, How, Module), 548 !.
552autoload_in(true, _, _). 553autoload_in(explicit, explicit, _). 554autoload_in(explicit_or_user, explicit, _). 555autoload_in(user, explicit, user). 556autoload_in(explicit_or_user, explicit, _). 557autoload_in(user, _, user). 558autoload_in(explicit_or_user, general, user).
568do_autoload(Library, Module:Name/Arity, LoadModule) :- 569 functor(Head, Name, Arity), 570 '$update_autoload_level'([autoload(true)], Old), 571 verbose_autoload(Module:Name/Arity, Library), 572 '$compilation_mode'(OldComp, database), 573 ( Module == LoadModule 574 -> ensure_loaded(Module:Library) 575 ; ( '$get_predicate_attribute'(LoadModule:Head, defined, 1), 576 \+ '$loading'(Library) 577 -> Module:import(LoadModule:Name/Arity) 578 ; use_module(Module:Library, [Name/Arity]) 579 ) 580 ), 581 '$set_compilation_mode'(OldComp), 582 '$set_autoload_level'(Old), 583 '$c_current_predicate'(_, Module:Head). 584 585verbose_autoload(PI, Library) :- 586 current_prolog_flag(verbose_autoload, true), 587 !, 588 set_prolog_flag(verbose_autoload, false), 589 print_message(informational, autoload(PI, Library)), 590 set_prolog_flag(verbose_autoload, true). 591verbose_autoload(PI, Library) :- 592 print_message(silent, autoload(PI, Library)).
autoload(File). The module muse be
instantiated.601:- public % used from predicate_property/2 602 autoloadable/2. 603 604autoloadable(M:Head, FullFile) :- 605 atom(M), 606 current_module(M), 607 autoload_in(M, explicit), 608 ( callable(Head) 609 -> goal_name_arity(Head, Name, Arity), 610 autoload_from(M:Name/Arity, _, FullFile) 611 ; findall((M:H)-F, autoloadable_2(M:H, F), Pairs), 612 ( '$member'(M:Head-FullFile, Pairs) 613 ; current_autoload(M:File, Ctx, all), 614 library_info(File, Ctx, FullFile, _, Exports), 615 '$member'(PI, Exports), 616 '$pi_head'(PI, Head), 617 \+ memberchk(M:Head-_, Pairs) 618 ) 619 ). 620autoloadable(M:Head, FullFile) :- 621 ( var(M) 622 -> autoload_in(any, general) 623 ; autoload_in(M, general) 624 ), 625 ( callable(Head) 626 -> goal_name_arity(Head, Name, Arity), 627 ( '$find_library'(_, Name, Arity, _, FullFile) 628 -> true 629 ) 630 ; '$in_library'(Name, Arity, autoload), 631 functor(Head, Name, Arity) 632 ). 633 634 635autoloadable_2(M:Head, FullFile) :- 636 current_autoload(M:File, Ctx, import(Imports)), 637 library_info(File, Ctx, FullFile, _LoadModule, _Exports), 638 '$member'(PI, Imports), 639 '$pi_head'(PI, Head). 640 641goal_name_arity(Head, Name, Arity) :- 642 compound(Head), 643 !, 644 compound_name_arity(Head, Name, Arity). 645goal_name_arity(Head, Head, 0).
651library_info(Spec, _, FullFile, Module, Exports) :- 652 '$resolved_source_path'(Spec, FullFile, []), 653 !, 654 ( \+ '$loading_file'(FullFile, _Queue, _LoadThread) 655 -> '$current_module'(Module, FullFile), 656 '$module_property'(Module, exports(Exports)) 657 ; library_info_from_file(FullFile, Module, Exports) 658 ). 659library_info(Spec, Context, FullFile, Module, Exports) :- 660 ( Context = (Path:_Line) 661 -> Extra = [relative_to(Path)] 662 ; Extra = [] 663 ), 664 ( absolute_file_name(Spec, FullFile, 665 [ file_type(prolog), 666 access(read), 667 file_errors(fail) 668 | Extra 669 ]) 670 -> '$register_resolved_source_path'(Spec, FullFile), 671 library_info_from_file(FullFile, Module, Exports) 672 ; autoload_error(Context, no_file(Spec)), 673 fail 674 ). 675 676 677library_info_from_file(FullFile, Module, Exports) :- 678 setup_call_cleanup( 679 '$open_source'(FullFile, In, State, [], []), 680 '$term_in_file'(In, _Read, _RLayout, Term, _TLayout, _Stream, 681 [FullFile], []), 682 '$close_source'(State, true)), 683 ( Term = (:- module(Module, Exports)) 684 -> ! 685 ; nonvar(Term), 686 skip_header(Term) 687 -> fail 688 ; throw(error(domain_error(module_file, FullFile), _)) 689 ). 690 691skip_header(begin_of_file). 692 693 694:- dynamic printed/3. 695:- volatile printed/3. 696 697autoload_error(Context, Error) :- 698 suppress(Context, Error), 699 !. 700autoload_error(Context, Error) :- 701 get_time(Now), 702 assertz(printed(Context, Error, Now)), 703 print_message(warning, error(autoload(Error), autoload(Context))). 704 705suppress(Context, Error) :- 706 printed(Context, Error, Printed), 707 get_time(Now), 708 ( Now - Printed < 1 709 -> true 710 ; retractall(printed(Context, Error, _)), 711 fail 712 ). 713 714 715 /******************************* 716 * CALLBACK * 717 *******************************/ 718 719:- public 720 set_autoload/1.
false we should materialize all registered
requests for autoloading. We must do so before disabling autoloading
as loading the files may require autoloading.729set_autoload(FlagValue) :- 730 \+ autoload_in(FlagValue, explicit, any), 731 !, 732 setup_call_cleanup( 733 nb_setval('$autoload_disabling', true), 734 materialize_autoload(Count), 735 nb_delete('$autoload_disabling')), 736 print_message(informational, autoload(disabled(Count))). 737set_autoload(_). 738 739materialize_autoload(Count) :- 740 State = state(0), 741 forall(current_predicate(M:'$autoload'/3), 742 materialize_autoload(M, State)), 743 arg(1, State, Count). 744 745materialize_autoload(M, State) :- 746 ( current_autoload(M:File, Context, Import), 747 library_info(File, Context, FullFile, _LoadModule, _Exports), 748 arg(1, State, N0), 749 N is N0+1, 750 nb_setarg(1, State, N), 751 ( Import == all 752 -> verbose_autoload(M:all, FullFile), 753 use_module(M:FullFile) 754 ; Import = import(Preds) 755 -> verbose_autoload(M:Preds, FullFile), 756 use_module(M:FullFile, Preds) 757 ), 758 fail 759 ; true 760 ), 761 abolish(M:'$autoload'/3). 762 763 764 /******************************* 765 * AUTOLOAD/2 * 766 *******************************/ 767 768autoload(M:File) :- 769 ( \+ autoload_in(M, explicit) 770 ; nb_current('$autoload_disabling', true) 771 ), 772 !, 773 use_module(M:File). 774autoload(M:File) :- 775 '$must_be'(filespec, File), 776 source_context(Context), 777 retractall(M:'$autoload'(File, _, _)), 778 assert_autoload(M:'$autoload'(File, Context, all)). 779 780autoload(M:File, Imports) :- 781 ( \+ autoload_in(M, explicit) 782 ; nb_current('$autoload_disabling', true) 783 ), 784 !, 785 use_module(M:File, Imports). 786autoload(M:File, Imports0) :- 787 '$must_be'(filespec, File), 788 valid_imports(Imports0, Imports), 789 source_context(Context), 790 register_autoloads(Imports, M, File, Context), 791 ( current_autoload(M:File, _, import(Imports)) 792 -> true 793 ; assert_autoload(M:'$autoload'(File, Context, import(Imports))) 794 ). 795 796source_context(Path:Line) :- 797 source_location(Path, Line), 798 !. 799source_context(-). 800 801assert_autoload(Clause) :- 802 '$initialization_context'(Source, Ctx), 803 '$store_admin_clause2'(Clause, _Layout, Source, Ctx). 804 805valid_imports(Imports0, Imports) :- 806 '$must_be'(list, Imports0), 807 valid_import_list(Imports0, Imports). 808 809valid_import_list([], []). 810valid_import_list([H0|T0], [H|T]) :- 811 '$pi_head'(H0, Head), 812 '$pi_head'(H, Head), 813 valid_import_list(T0, T).
autoload flag on all predicates declared using autoload/2
to prevent duplicates or the user defining the same predicate.820register_autoloads([], _, _, _). 821register_autoloads([PI|T], Module, File, Context) :- 822 PI = Name/Arity, 823 functor(Head, Name, Arity), 824 ( '$get_predicate_attribute'(Module:Head, autoload, 1) 825 -> ( current_autoload(Module:_File0, _Ctx0, import(Imports)), 826 memberchk(PI, Imports) 827 -> '$permission_error'(redefine, imported_procedure, PI), 828 fail 829 ; Done = true 830 ) 831 ; '$get_predicate_attribute'(Module:Head, imported, From) 832 -> ( ( '$resolved_source_path'(File, FullFile) 833 -> true 834 ; '$resolve_source_path'(File, FullFile, []) 835 ), 836 module_property(From, file(FullFile)) 837 -> Done = true 838 ; print_message(warning, 839 autoload(already_defined(Module:PI, From))), 840 Done = true 841 ) 842 ; true 843 ), 844 ( Done == true 845 -> true 846 ; '$set_predicate_attribute'(Module:Head, autoload, 1) 847 ), 848 register_autoloads(T, Module, File, Context). 849 850pi_in_exports(PI, Exports) :- 851 '$member'(E, Exports), 852 canonical_pi(E, PI), 853 !. 854 855current_autoload(M:File, Context, Term) :- 856 '$get_predicate_attribute'(M:'$autoload'(_,_,_), defined, 1), 857 M:'$autoload'(File, Context, Term). 858 859 /******************************* 860 * REQUIRE * 861 *******************************/
868require(M:Spec) :- 869 ( is_list(Spec) 870 -> List = Spec 871 ; phrase(comma_list(Spec), List) 872 ), !, 873 require(List, M, FromLib), 874 keysort(FromLib, Sorted), 875 by_file(Sorted, Autoload), 876 forall('$member'(File-Import, Autoload), 877 autoload(M:File, Import)). 878require(_:Spec) :- 879 '$type_error'(list, Spec). 880 881require([],_, []). 882require([H|T], M, Needed) :- 883 '$pi_head'(H, Head), 884 ( '$get_predicate_attribute'(system:Head, defined, 1) 885 -> require(T, M, Needed) 886 ; '$pi_head'(Module:Name/Arity, M:Head), 887 ( '$find_library'(Module, Name, Arity, _LoadModule, Library) 888 -> Needed = [Library-H|More], 889 require(T, M, More) 890 ; print_message(error, error(existence_error(procedure, Name/Arity), _)), 891 require(T, M, Needed) 892 ) 893 ). 894 895by_file([], []). 896by_file([File-PI|T0], [Spec-[PI|PIs]|T]) :- 897 on_path(File, Spec), 898 same_file(T0, File, PIs, T1), 899 by_file(T1, T). 900 901on_path(Library, library(Base)) :- 902 file_base_name(Library, Base), 903 findall(Path, plain_source(library(Base), Path), [Library]), 904 !. 905on_path(Library, Library). 906 907plain_source(Spec, Path) :- 908 absolute_file_name(Spec, PathExt, 909 [ file_type(prolog), 910 access(read), 911 file_errors(fail), 912 solutions(all) 913 ]), 914 file_name_extension(Path, _, PathExt). 915 916same_file([File-PI|T0], File, [PI|PIs], T) :- 917 !, 918 same_file(T0, File, PIs, T). 919same_file(List, _, [], List). 920 921comma_list(Var) --> 922 { var(Var), 923 !, 924 '$instantiation_error'(Var) 925 }. 926comma_list((A,B)) --> 927 !, 928 comma_list(A), 929 comma_list(B). 930comma_list(A) --> 931 [A]