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) 2011-2020, VU University Amsterdam 7 CWI, Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(prolog_autoload, 37 [ autoload_all/0, 38 autoload_all/1 % +Options 39 ]). 40:- use_module(library(check), []). % uses :- public predicates 41 42:- autoload(library(aggregate),[aggregate_all/3]). 43:- autoload(library(error),[must_be/2,existence_error/2]). 44:- autoload(library(option),[option/2,option/3]). 45:- autoload(library(prolog_codewalk),[prolog_walk_code/1]). 46 47:- predicate_options(autoload_all/1, 1, 48 [ verbose(boolean), 49 undefined(oneof([ignore,error])) 50 ]).
80:- thread_local
81 autoloaded_count/1.autoload to false, resolving explicit autoloading
and then finds all undefined references to autoloadable predicates
and load the library files that define these predicates.
Options:
true (default false), report on the files loaded.ignore or
error. Default is ignore.100autoload_all :- 101 autoload_all([]). 102 103autoload_all(Options) :- 104 set_prolog_flag(autoload, false), 105 must_be(list, Options), 106 statistics(cputime, T0), 107 aggregate_all(count, source_file(_), OldFileCount), 108 call_cleanup( 109 autoload(0, Iterations, Options), 110 check:collect_undef(Undef)), 111 aggregate_all(count, source_file(_), NewFileCount), 112 statistics(cputime, T1), 113 Time is T1-T0, 114 information_level(Level, Options), 115 NewFiles is NewFileCount - OldFileCount, 116 print_message(Level, autoload(completed(Iterations, Time, NewFiles))), 117 report_undefined(Undef). 118 119autoload(Iteration0, Iterations, Options) :- 120 statistics(cputime, T0), 121 autoload_step(NewFiles, NewPreds, Options), 122 statistics(cputime, T1), 123 Time is T1-T0, 124 succ(Iteration0, Iteration), 125 ( NewFiles > 0 126 -> information_level(Level, Options), 127 print_message(Level, autoload(reiterate(Iteration, 128 NewFiles, NewPreds, Time))), 129 autoload(Iteration, Iterations, Options) 130 ; Iterations = Iteration 131 ). 132 133information_level(Level, Options) :- 134 ( option(verbose(true), Options) 135 -> Level = informational 136 ; Level = silent 137 ).
148autoload_step(NewFiles, NewPreds, Options) :- 149 option(verbose(Verbose), Options, false), 150 walk_options(Options, WalkOptions), 151 aggregate_all(count, source_file(_), OldFileCount), 152 setup_call_cleanup( 153 ( current_prolog_flag(autoload, OldAutoLoad), 154 current_prolog_flag(verbose_autoload, OldVerbose), 155 set_prolog_flag(autoload, true), 156 set_prolog_flag(verbose_autoload, Verbose), 157 assert_autoload_hook(Ref), 158 asserta(autoloaded_count(0)) 159 ), 160 prolog_walk_code(WalkOptions), 161 ( retract(autoloaded_count(Count)), 162 erase(Ref), 163 set_prolog_flag(autoload, OldAutoLoad), 164 set_prolog_flag(verbose_autoload, OldVerbose) 165 )), 166 aggregate_all(count, source_file(_), NewFileCount), 167 NewPreds = Count, 168 NewFiles is NewFileCount - OldFileCount. 169 170assert_autoload_hook(Ref) :- 171 asserta((user:message_hook(autoload(Module:Name/Arity, Library), _, _) :- 172 autoloaded(Module:Name/Arity, Library)), Ref). 173 174:- public 175 autoloaded/2. 176 177autoloaded(_, _) :- 178 retract(autoloaded_count(N)), 179 succ(N, N2), 180 asserta(autoloaded_count(N2)), 181 fail. % proceed with other hooks
190walk_options([], []). 191walk_options([verbose(V)|T0], [verbose(V)|T]) :- 192 !, 193 walk_options(T0, T). 194walk_options([undefined(error)|T0], 195 [ undefined(trace), 196 on_trace(check:found_undef) 197 | T 198 ]) :- 199 !, 200 walk_options(T0, T). 201walk_options([_|T0], T) :- 202 walk_options(T0, T).
209report_undefined([]) :- 210 !. 211report_undefined(Grouped) :- 212 existence_error(procedures, Grouped). 213 214 215 /******************************* 216 * MESSAGES * 217 *******************************/ 218 219:- multifile 220 prolog:message//1, 221 prolog:error_message//1. 222 223prologmessage(autoload(reiterate(Iteration, NewFiles, NewPreds, Time))) --> 224 [ 'Autoloader: iteration ~D resolved ~D predicates \c 225 and loaded ~D files in ~3f seconds. Restarting ...'- 226 [Iteration, NewPreds, NewFiles, Time] 227 ]. 228prologmessage(autoload(completed(Iterations, Time, NewFiles))) --> 229 [ 'Autoloader: loaded ~D files in ~D iterations in ~3f seconds'- 230 [NewFiles, Iterations, Time] ]. 231 232prologerror_message(existence_error(procedures, Grouped)) --> 233 prolog:message(check(undefined_procedures, Grouped))
Autoload all dependencies
The autoloader is there to smoothen program development. It liberates the programmer from finding the library that defines some particular predicate and including the proper use_module/1,2 directive in the sources. This is even better at the toplevel, where just using maplist/3 is way more comfortable than first having to load library(apply). In addition, it reduces the startup time of applications by only loading the necessary bits.
Of course, there is also a price. One is that it becomes less obvious from where some predicate is loaded and thus whether you have the right definition. The second issue is that it is harder to create a stand-alone executable because this executable, without access to the development system, can no longer rely on autoloading.
This library provides autoload_all/0 and autoload_all/1 to autoload all predicates that are referenced by the program. Now, this is in general not possible in Prolog because the language allows for constructing arbitrary goals and runtime and calling them (e.g.,
read(X),call(X)).The implementation relies on code analysis of the bodies of all clauses and all initialization goals.
As of SWI-Prolog 8.1.22 the system provides autoload/1,2 directives that mitigate the possible ambiguity. */