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/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 2011-2020, VU University Amsterdam
CWI, Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(prolog_autoload,
[ autoload_all/0,
autoload_all/1 % +Options
]).
:- use_module(library(check), []). % uses :- public predicates
:- autoload(library(aggregate),[aggregate_all/3]).
:- autoload(library(error),[must_be/2,existence_error/2]).
:- autoload(library(option),[option/2,option/3]).
:- autoload(library(prolog_codewalk),[prolog_walk_code/1]).
:- predicate_options(autoload_all/1, 1,
[ verbose(boolean),
undefined(oneof([ignore,error]))
]).
/** <module> 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.
*/
:- thread_local
autoloaded_count/1.
%! autoload_all is det.
%! autoload_all(+Options) is det.
%
% Force all necessary autoloading to be done _now_. This sets the
% Prolog flag `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:
%
% * verbose(+Boolean)
% If `true` (default `false`), report on the files loaded.
% * undefined(+Action)
% Action defines what happens if the analysis finds a
% definitely undefined predicate. One of `ignore` or
% `error`. Default is `ignore`.
autoload_all :-
autoload_all([]).
autoload_all(Options) :-
set_prolog_flag(autoload, false),
must_be(list, Options),
statistics(cputime, T0),
aggregate_all(count, source_file(_), OldFileCount),
call_cleanup(
autoload(0, Iterations, Options),
check:collect_undef(Undef)),
aggregate_all(count, source_file(_), NewFileCount),
statistics(cputime, T1),
Time is T1-T0,
information_level(Level, Options),
NewFiles is NewFileCount - OldFileCount,
print_message(Level, autoload(completed(Iterations, Time, NewFiles))),
report_undefined(Undef).
autoload(Iteration0, Iterations, Options) :-
statistics(cputime, T0),
autoload_step(NewFiles, NewPreds, Options),
statistics(cputime, T1),
Time is T1-T0,
succ(Iteration0, Iteration),
( NewFiles > 0
-> information_level(Level, Options),
print_message(Level, autoload(reiterate(Iteration,
NewFiles, NewPreds, Time))),
autoload(Iteration, Iterations, Options)
; Iterations = Iteration
).
information_level(Level, Options) :-
( option(verbose(true), Options)
-> Level = informational
; Level = silent
).
%! autoload_step(-NewFiles, -NewPreds, +Options) is det.
%
% Scan through the program and autoload all undefined referenced
% predicates.
%
% @param NewFiles is unified to the number of files loaded
% @param NewPreds is unified to the number of predicates imported
% using the autoloader.
autoload_step(NewFiles, NewPreds, Options) :-
option(verbose(Verbose), Options, false),
walk_options(Options, WalkOptions),
aggregate_all(count, source_file(_), OldFileCount),
setup_call_cleanup(
( current_prolog_flag(autoload, OldAutoLoad),
current_prolog_flag(verbose_autoload, OldVerbose),
set_prolog_flag(autoload, true),
set_prolog_flag(verbose_autoload, Verbose),
assert_autoload_hook(Ref),
asserta(autoloaded_count(0))
),
prolog_walk_code(WalkOptions),
( retract(autoloaded_count(Count)),
erase(Ref),
set_prolog_flag(autoload, OldAutoLoad),
set_prolog_flag(verbose_autoload, OldVerbose)
)),
aggregate_all(count, source_file(_), NewFileCount),
NewPreds = Count,
NewFiles is NewFileCount - OldFileCount.
assert_autoload_hook(Ref) :-
asserta((user:message_hook(autoload(Module:Name/Arity, Library), _, _) :-
autoloaded(Module:Name/Arity, Library)), Ref).
:- public
autoloaded/2.
autoloaded(_, _) :-
retract(autoloaded_count(N)),
succ(N, N2),
asserta(autoloaded_count(N2)),
fail. % proceed with other hooks
%! walk_options(+AutoloadOptions, -WalkOptions) is det.
%
% Construct the option list for the code walker. If we see an
% undefined predicate, we must collect these rather than printing them
% or immediately terminating with an exception. This reuses code from
% library(check).
walk_options([], []).
walk_options([verbose(V)|T0], [verbose(V)|T]) :-
!,
walk_options(T0, T).
walk_options([undefined(error)|T0],
[ undefined(trace),
on_trace(check:found_undef)
| T
]) :-
!,
walk_options(T0, T).
walk_options([_|T0], T) :-
walk_options(T0, T).
%! report_undefined(+Undefined) is det.
%
%
report_undefined([]) :-
!.
report_undefined(Grouped) :-
existence_error(procedures, Grouped).
/*******************************
* MESSAGES *
*******************************/
:- multifile
prolog:message//1,
prolog:error_message//1.
prolog:message(autoload(reiterate(Iteration, NewFiles, NewPreds, Time))) -->
[ 'Autoloader: iteration ~D resolved ~D predicates \c
and loaded ~D files in ~3f seconds. Restarting ...'-
[Iteration, NewPreds, NewFiles, Time]
].
prolog:message(autoload(completed(Iterations, Time, NewFiles))) -->
[ 'Autoloader: loaded ~D files in ~D iterations in ~3f seconds'-
[NewFiles, Iterations, Time] ].
prolog:error_message(existence_error(procedures, Grouped)) -->
prolog:message(check(undefined_procedures, Grouped)).
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