mirror of
https://git.savannah.gnu.org/git/parallel.git
synced 2024-11-24 23:17:55 +00:00
353 lines
10 KiB
Perl
353 lines
10 KiB
Perl
# Generated from XSLoader.pm.PL (resolved %Config::Config value)
|
|
|
|
package XSLoader;
|
|
|
|
$VERSION = "0.13";
|
|
|
|
#use strict;
|
|
|
|
# enable debug/trace messages from DynaLoader perl code
|
|
# $dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
|
|
|
|
package DynaLoader;
|
|
|
|
# No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
|
|
# NOTE: All dl_*.xs (including dl_none.xs) define a dl_error() XSUB
|
|
boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
|
|
!defined(&dl_error);
|
|
package XSLoader;
|
|
|
|
sub load {
|
|
package DynaLoader;
|
|
|
|
my ($module, $modlibname) = caller();
|
|
|
|
if (@_) {
|
|
$module = $_[0];
|
|
} else {
|
|
$_[0] = $module;
|
|
}
|
|
|
|
# work with static linking too
|
|
my $boots = "$module\::bootstrap";
|
|
goto &$boots if defined &$boots;
|
|
|
|
goto \&XSLoader::bootstrap_inherit unless $module and defined &dl_load_file;
|
|
|
|
my @modparts = split(/::/,$module);
|
|
my $modfname = $modparts[-1];
|
|
|
|
my $modpname = join('/',@modparts);
|
|
my $c = @modparts;
|
|
$modlibname =~ s,[\\/][^\\/]+$,, while $c--; # Q&D basename
|
|
my $file = "$modlibname/auto/$modpname/$modfname.so";
|
|
|
|
# print STDERR "XSLoader::load for $module ($file)\n" if $dl_debug;
|
|
|
|
my $bs = $file;
|
|
$bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
|
|
|
|
if (-s $bs) { # only read file if it's not empty
|
|
# print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
|
|
eval { do $bs; };
|
|
warn "$bs: $@\n" if $@;
|
|
}
|
|
|
|
goto \&XSLoader::bootstrap_inherit if not -f $file or -s $bs;
|
|
|
|
my $bootname = "boot_$module";
|
|
$bootname =~ s/\W/_/g;
|
|
@DynaLoader::dl_require_symbols = ($bootname);
|
|
|
|
my $boot_symbol_ref;
|
|
|
|
# Many dynamic extension loading problems will appear to come from
|
|
# this section of code: XYZ failed at line 123 of DynaLoader.pm.
|
|
# Often these errors are actually occurring in the initialisation
|
|
# C code of the extension XS file. Perl reports the error as being
|
|
# in this perl code simply because this was the last perl code
|
|
# it executed.
|
|
|
|
my $libref = dl_load_file($file, 0) or do {
|
|
require Carp;
|
|
Carp::croak("Can't load '$file' for module $module: " . dl_error());
|
|
};
|
|
push(@DynaLoader::dl_librefs,$libref); # record loaded object
|
|
|
|
my @unresolved = dl_undef_symbols();
|
|
if (@unresolved) {
|
|
require Carp;
|
|
Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
|
|
}
|
|
|
|
$boot_symbol_ref = dl_find_symbol($libref, $bootname) or do {
|
|
require Carp;
|
|
Carp::croak("Can't find '$bootname' symbol in $file\n");
|
|
};
|
|
|
|
push(@DynaLoader::dl_modules, $module); # record loaded module
|
|
|
|
boot:
|
|
my $xs = dl_install_xsub($boots, $boot_symbol_ref, $file);
|
|
|
|
# See comment block above
|
|
push(@DynaLoader::dl_shared_objects, $file); # record files loaded
|
|
return &$xs(@_);
|
|
}
|
|
|
|
sub bootstrap_inherit {
|
|
require DynaLoader;
|
|
goto \&DynaLoader::bootstrap_inherit;
|
|
}
|
|
|
|
1;
|
|
|
|
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
XSLoader - Dynamically load C libraries into Perl code
|
|
|
|
=head1 VERSION
|
|
|
|
Version 0.13
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
package YourPackage;
|
|
require XSLoader;
|
|
|
|
XSLoader::load();
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
This module defines a standard I<simplified> interface to the dynamic
|
|
linking mechanisms available on many platforms. Its primary purpose is
|
|
to implement cheap automatic dynamic loading of Perl modules.
|
|
|
|
For a more complicated interface, see L<DynaLoader>. Many (most)
|
|
features of C<DynaLoader> are not implemented in C<XSLoader>, like for
|
|
example the C<dl_load_flags>, not honored by C<XSLoader>.
|
|
|
|
=head2 Migration from C<DynaLoader>
|
|
|
|
A typical module using L<DynaLoader|DynaLoader> starts like this:
|
|
|
|
package YourPackage;
|
|
require DynaLoader;
|
|
|
|
our @ISA = qw( OnePackage OtherPackage DynaLoader );
|
|
our $VERSION = '0.01';
|
|
bootstrap YourPackage $VERSION;
|
|
|
|
Change this to
|
|
|
|
package YourPackage;
|
|
use XSLoader;
|
|
|
|
our @ISA = qw( OnePackage OtherPackage );
|
|
our $VERSION = '0.01';
|
|
XSLoader::load 'YourPackage', $VERSION;
|
|
|
|
In other words: replace C<require DynaLoader> by C<use XSLoader>, remove
|
|
C<DynaLoader> from C<@ISA>, change C<bootstrap> by C<XSLoader::load>. Do not
|
|
forget to quote the name of your package on the C<XSLoader::load> line,
|
|
and add comma (C<,>) before the arguments (C<$VERSION> above).
|
|
|
|
Of course, if C<@ISA> contained only C<DynaLoader>, there is no need to have
|
|
the C<@ISA> assignment at all; moreover, if instead of C<our> one uses the
|
|
more backward-compatible
|
|
|
|
use vars qw($VERSION @ISA);
|
|
|
|
one can remove this reference to C<@ISA> together with the C<@ISA> assignment.
|
|
|
|
If no C<$VERSION> was specified on the C<bootstrap> line, the last line becomes
|
|
|
|
XSLoader::load 'YourPackage';
|
|
|
|
If the call to C<load> is from the YourPackage, then that can be further
|
|
simplified to
|
|
|
|
XSLoader::load();
|
|
|
|
as C<load> will use C<caller> to determine the package.
|
|
|
|
=head2 Backward compatible boilerplate
|
|
|
|
If you want to have your cake and eat it too, you need a more complicated
|
|
boilerplate.
|
|
|
|
package YourPackage;
|
|
use vars qw($VERSION @ISA);
|
|
|
|
@ISA = qw( OnePackage OtherPackage );
|
|
$VERSION = '0.01';
|
|
eval {
|
|
require XSLoader;
|
|
XSLoader::load('YourPackage', $VERSION);
|
|
1;
|
|
} or do {
|
|
require DynaLoader;
|
|
push @ISA, 'DynaLoader';
|
|
bootstrap YourPackage $VERSION;
|
|
};
|
|
|
|
The parentheses about C<XSLoader::load()> arguments are needed since we replaced
|
|
C<use XSLoader> by C<require>, so the compiler does not know that a function
|
|
C<XSLoader::load()> is present.
|
|
|
|
This boilerplate uses the low-overhead C<XSLoader> if present; if used with
|
|
an antic Perl which has no C<XSLoader>, it falls back to using C<DynaLoader>.
|
|
|
|
=head1 Order of initialization: early load()
|
|
|
|
I<Skip this section if the XSUB functions are supposed to be called from other
|
|
modules only; read it only if you call your XSUBs from the code in your module,
|
|
or have a C<BOOT:> section in your XS file (see L<perlxs/"The BOOT: Keyword">).
|
|
What is described here is equally applicable to the L<DynaLoader|DynaLoader>
|
|
interface.>
|
|
|
|
A sufficiently complicated module using XS would have both Perl code (defined
|
|
in F<YourPackage.pm>) and XS code (defined in F<YourPackage.xs>). If this
|
|
Perl code makes calls into this XS code, and/or this XS code makes calls to
|
|
the Perl code, one should be careful with the order of initialization.
|
|
|
|
The call to C<XSLoader::load()> (or C<bootstrap()>) calls the module's
|
|
bootstrap code. For modules build by F<xsubpp> (nearly all modules) this
|
|
has three side effects:
|
|
|
|
=over
|
|
|
|
=item *
|
|
|
|
A sanity check is done to ensure that the versions of the F<.pm> and the
|
|
(compiled) F<.xs> parts are compatible. If C<$VERSION> was specified, this
|
|
is used for the check. If not specified, it defaults to
|
|
C<$XS_VERSION // $VERSION> (in the module's namespace)
|
|
|
|
=item *
|
|
|
|
the XSUBs are made accessible from Perl
|
|
|
|
=item *
|
|
|
|
if a C<BOOT:> section was present in the F<.xs> file, the code there is called.
|
|
|
|
=back
|
|
|
|
Consequently, if the code in the F<.pm> file makes calls to these XSUBs, it is
|
|
convenient to have XSUBs installed before the Perl code is defined; for
|
|
example, this makes prototypes for XSUBs visible to this Perl code.
|
|
Alternatively, if the C<BOOT:> section makes calls to Perl functions (or
|
|
uses Perl variables) defined in the F<.pm> file, they must be defined prior to
|
|
the call to C<XSLoader::load()> (or C<bootstrap()>).
|
|
|
|
The first situation being much more frequent, it makes sense to rewrite the
|
|
boilerplate as
|
|
|
|
package YourPackage;
|
|
use XSLoader;
|
|
use vars qw($VERSION @ISA);
|
|
|
|
BEGIN {
|
|
@ISA = qw( OnePackage OtherPackage );
|
|
$VERSION = '0.01';
|
|
|
|
# Put Perl code used in the BOOT: section here
|
|
|
|
XSLoader::load 'YourPackage', $VERSION;
|
|
}
|
|
|
|
# Put Perl code making calls into XSUBs here
|
|
|
|
=head2 The most hairy case
|
|
|
|
If the interdependence of your C<BOOT:> section and Perl code is
|
|
more complicated than this (e.g., the C<BOOT:> section makes calls to Perl
|
|
functions which make calls to XSUBs with prototypes), get rid of the C<BOOT:>
|
|
section altogether. Replace it with a function C<onBOOT()>, and call it like
|
|
this:
|
|
|
|
package YourPackage;
|
|
use XSLoader;
|
|
use vars qw($VERSION @ISA);
|
|
|
|
BEGIN {
|
|
@ISA = qw( OnePackage OtherPackage );
|
|
$VERSION = '0.01';
|
|
XSLoader::load 'YourPackage', $VERSION;
|
|
}
|
|
|
|
# Put Perl code used in onBOOT() function here; calls to XSUBs are
|
|
# prototype-checked.
|
|
|
|
onBOOT;
|
|
|
|
# Put Perl initialization code assuming that XS is initialized here
|
|
|
|
|
|
=head1 DIAGNOSTICS
|
|
|
|
=over
|
|
|
|
=item C<Can't find '%s' symbol in %s>
|
|
|
|
B<(F)> The bootstrap symbol could not be found in the extension module.
|
|
|
|
=item C<Can't load '%s' for module %s: %s>
|
|
|
|
B<(F)> The loading or initialisation of the extension module failed.
|
|
The detailed error follows.
|
|
|
|
=item C<Undefined symbols present after loading %s: %s>
|
|
|
|
B<(W)> As the message says, some symbols stay undefined although the
|
|
extension module was correctly loaded and initialised. The list of undefined
|
|
symbols follows.
|
|
|
|
=back
|
|
|
|
=head1 LIMITATIONS
|
|
|
|
To reduce the overhead as much as possible, only one possible location
|
|
is checked to find the extension DLL (this location is where C<make install>
|
|
would put the DLL). If not found, the search for the DLL is transparently
|
|
delegated to C<DynaLoader>, which looks for the DLL along the C<@INC> list.
|
|
|
|
In particular, this is applicable to the structure of C<@INC> used for testing
|
|
not-yet-installed extensions. This means that running uninstalled extensions
|
|
may have much more overhead than running the same extensions after
|
|
C<make install>.
|
|
|
|
|
|
=head1 BUGS
|
|
|
|
Please report any bugs or feature requests via the perlbug(1) utility.
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<DynaLoader>
|
|
|
|
|
|
=head1 AUTHORS
|
|
|
|
Ilya Zakharevich originally extracted C<XSLoader> from C<DynaLoader>.
|
|
|
|
CPAN version is currently maintained by SE<eacute>bastien Aperghis-Tramoni
|
|
E<lt>sebastien@aperghis.netE<gt>.
|
|
|
|
Previous maintainer was Michael G Schwern <schwern@pobox.com>.
|
|
|
|
|
|
=head1 COPYRIGHT & LICENSE
|
|
|
|
Copyright (C) 1990-2007 by Larry Wall and others.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the same terms as Perl itself.
|
|
|
|
=cut
|