pkgsrc/lang/swi-prolog-lite/files/shlib.pl
2004-05-20 11:09:16 +00:00

293 lines
8.6 KiB
Prolog

/* $Id: shlib.pl,v 1.1.1.1 2004/05/20 11:09:17 hubertf Exp $
Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: jan@swi.psy.uva.nl
WWW: http://www.swi-prolog.org
Copyright (C): 1985-2002, University of Amsterdam
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
As a special exception, if you link this library with other files,
compiled with a Free Software compiler, to produce an executable, this
library does not by itself cause the resulting executable to be covered
by the GNU General Public License. This exception does not however
invalidate any other reasons why the executable file might be covered by
the GNU General Public License.
*/
:- module(shlib,
[ load_foreign_library/1, % :LibFile
load_foreign_library/2, % :LibFile, +InstallFunc
unload_foreign_library/1, % +LibFile
unload_foreign_library/2, % +LibFile, +UninstallFunc
current_foreign_library/2, % ?LibFile, ?Public
reload_foreign_libraries/0
]).
:- set_prolog_flag(generate_debug_info, false).
:- module_transparent
load_foreign_library/1,
load_foreign_library/2.
:- dynamic
loading/1, % Lib
error/2, % File, Error
foreign_predicate/2, % Lib, Pred
current_library/5. % Lib, Entry, Path, Module, Handle
:- volatile % Do not store in state
loading/1,
error/2,
foreign_predicate/2,
current_library/5.
:- ( current_prolog_flag(open_shared_object, true)
-> true
; print_message(warning, shlib(not_supported)) % error?
).
/*******************************
* DISPATCHING *
*******************************/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Windows: If libpl.dll is compiled for debugging, prefer loading <lib>D.dll
to allow for debugging.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
find_library(Spec, Lib) :-
current_prolog_flag(windows, true),
current_prolog_flag(kernel_compile_mode, debug),
libd_spec(Spec, SpecD),
catch(find_library2(SpecD, Lib), _, fail).
find_library(Spec, Lib) :-
find_library2(Spec, Lib).
find_library2(Spec, Lib) :-
absolute_file_name(Spec,
[ file_type(executable),
access(read),
file_errors(fail)
], Lib), !.
find_library2(Spec, Spec) :-
atom(Spec), !. % use machines finding schema
find_library2(foreign(Spec), Spec) :-
atom(Spec), !. % use machines finding schema
find_library2(Spec, _) :-
throw(error(existence_error(source_sink, Spec), _)).
libd_spec(Name, NameD) :-
atomic(Name),
file_name_extension(Base, Ext, Name),
atom_concat(Base, 'D', BaseD),
file_name_extension(BaseD, Ext, NameD).
libd_spec(Spec, SpecD) :-
compound(Spec),
Spec =.. [Alias,Name],
libd_spec(Name, NameD),
SpecD =.. [Alias,NameD].
libd_spec(Spec, Spec). % delay errors
base(Path, Base) :-
atomic(Path), !,
file_base_name(Path, File),
file_name_extension(Base, _Ext, File).
base(Path, Base) :-
Path =.. [_,Arg],
base(Arg, Base).
entry(_, Function, Function) :-
Function \= default(_), !.
entry(Spec, default(FuncBase), Function) :-
base(Spec, Base),
concat_atom([FuncBase, Base], '_', Function).
entry(_, default(Function), Function).
/*******************************
* (UN)LOADING *
*******************************/
load_foreign_library(Library) :-
load_foreign_library(Library, default(install)).
load_foreign_library(LibFileSpec, Entry) :-
'$strip_module'(LibFileSpec, Module, LibFile),
with_mutex('$foreign',
shlib:load_foreign_library(LibFile, Module, Entry)).
load_foreign_library(LibFile, _Module, _) :-
current_library(LibFile, _, _, _, _), !.
load_foreign_library(LibFile, Module, DefEntry) :-
retractall(error(_, _)),
find_library(LibFile, Path),
asserta(loading(LibFile)),
catch(Module:open_shared_object(Path, Handle), E, true),
( nonvar(E)
-> assert(error(Path, E)),
fail
; true
), !,
( ( entry(LibFile, DefEntry, Entry),
Module:call_shared_object_function(Handle, Entry)
-> true
; DefEntry == default(install)
)
-> retractall(loading(LibFile)),
assert_shlib(LibFile, Entry, Path, Module, Handle)
; retractall(loading(LibFile)),
close_shared_object(Handle),
print_message(error, shlib(LibFile, call_entry(DefEntry))),
fail
).
load_foreign_library(LibFile, _, _) :-
retractall(loading(LibFile)),
( error(_Path, E)
-> retractall(error(_, _)),
throw(E)
; throw(error(existence_error(foreign_library, LibFile), _))
).
unload_foreign_library(LibFile) :-
unload_foreign_library(LibFile, default(uninstall)).
unload_foreign_library(LibFile, DefUninstall) :-
with_mutex('$foreign', do_unload(LibFile, DefUninstall)).
do_unload(LibFile, DefUninstall) :-
current_library(LibFile, _, _, Module, Handle),
retractall(current_library(LibFile, _, _, _, _)),
( entry(LibFile, DefUninstall, Uninstall),
Module:call_shared_object_function(Handle, Uninstall)
-> true
; true
),
abolish_foreign(LibFile),
close_shared_object(Handle).
abolish_foreign(LibFile) :-
( retract(foreign_predicate(LibFile, Module:Head)),
functor(Head, Name, Arity),
abolish(Module:Name, Arity),
fail
; true
).
system:'$foreign_registered'(M, H) :-
( loading(Lib)
-> true
; Lib = '<spontaneous>'
),
assert(foreign_predicate(Lib, M:H)).
assert_shlib(File, Entry, Path, Module, Handle) :-
retractall(current_library(File, _, _, _, _)),
asserta(current_library(File, Entry, Path, Module, Handle)).
/*******************************
* ADMINISTRATION *
*******************************/
% current_foreign_library(?File, ?Public)
%
% Query currently loaded shared libraries
current_foreign_library(File, Public) :-
current_library(File, _Entry, _Path, _Module, _Handle),
findall(Pred, foreign_predicate(File, Pred), Public).
/*******************************
* RELOAD *
*******************************/
% reload_foreign_libraries
%
% Reload all foreign libraries loaded (after restore of a state
% craeted using qsave_program/2.
reload_foreign_libraries :-
findall(lib(File, Entry, Module),
( retract(current_library(File, Entry, _, Module, _)),
File \== -
),
Libs),
reverse(Libs, Reversed),
reload_libraries(Reversed).
reload_libraries([]).
reload_libraries([lib(File, Entry, Module)|T]) :-
( load_foreign_library(File, Module, Entry)
-> true
; print_message(error, shlib(File, load_failed))
),
reload_libraries(T).
/*******************************
* CLEANUP (WINDOWS ...) *
*******************************/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Called from Halt() in pl-os.c (if it is defined), *after* all at_halt/1
hooks have been executed, and after dieIO(), closing and flushing all
files has been called.
On Unix, this is not very useful, and can only lead to conflicts.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
unload_all_foreign_libraries :-
current_prolog_flag(unix, true), !.
unload_all_foreign_libraries :-
forall(current_library(File, _, _, _, _),
unload_foreign(File)).
% unload_foreign(+File)
%
% Unload the given foreign file and all `spontaneous' foreign
% predicates created afterwards. Handling these spontaneous
% predicates is a bit hard, as we do not know who created them and
% on which library they depend.
unload_foreign(File) :-
unload_foreign_library(File),
( clause(foreign_predicate(Lib, M:H), true, Ref),
( Lib == '<spontaneous>'
-> functor(H, Name, Arity),
abolish(M:Name, Arity),
erase(Ref),
fail
; !
)
-> true
; true
).
/*******************************
* MESSAGES *
*******************************/
:- multifile
prolog:message/3.
prolog:message(shlib(LibFile, call_entry(DefEntry))) -->
[ '~w: Failed to call entry-point ~w'-[LibFile, DefEntry] ].
prolog:message(shlib(LibFile, load_failed)) -->
[ '~w: Failed to load file'-[LibFile] ].
prolog:message(shlib(not_supported)) -->
[ 'Emulator does not support foreign libraries' ].