11 1 while unlink "XSLoader.pm";
12 open OUT, ">XSLoader.pm" or die $!;
14 # Generated from XSLoader.pm.PL (resolved %Config::Config value)
22 # enable debug/trace messages from DynaLoader perl code
23 # $dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
27 print OUT ' my $dl_dlext = ', to_string($Config::Config{'dlext'}), ";\n" ;
33 # No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
34 # NOTE: All dl_*.xs (including dl_none.xs) define a dl_error() XSUB
35 boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
42 die q{XSLoader::load('Your::Module', $Your::Module::VERSION)} unless @_;
46 # work with static linking too
47 my $boots = "$module\::bootstrap";
48 goto &$boots if defined &$boots;
50 goto retry unless $module and defined &dl_load_file;
52 my @modparts = split(/::/,$module);
53 my $modfname = $modparts[-1];
57 print OUT <<'EOT' if defined &DynaLoader::mod2fname;
58 # Some systems have restrictions on files names for DLL's etc.
59 # mod2fname returns appropriate file base name (typically truncated)
60 # It may also edit @modparts if required.
61 $modfname = &mod2fname(\@modparts) if defined &mod2fname;
65 print OUT <<'EOT' if $^O eq 'os2';
67 # os2 static build can dynaload, but cannot dynaload Perl modules...
68 die 'Dynaloaded Perl modules are not available in this build of Perl' if $OS2::is_static;
73 my $modpname = join('/',@modparts);
74 my $modlibname = (caller())[1];
76 $modlibname =~ s,[\\/][^\\/]+$,, while $c--; # Q&D basename
77 my $file = "$modlibname/auto/$modpname/$modfname.$dl_dlext";
79 # print STDERR "XSLoader::load for $module ($file)\n" if $dl_debug;
82 $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
84 if (-s $bs) { # only read file if it's not empty
85 # print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
87 warn "$bs: $@\n" if $@;
90 goto retry if not -f $file or -s $bs;
92 my $bootname = "boot_$module";
93 $bootname =~ s/\W/_/g;
94 @DynaLoader::dl_require_symbols = ($bootname);
100 if ($^O eq 'darwin') {
102 if ($boot_symbol_ref = dl_find_symbol(0, $bootname)) {
103 goto boot; #extension library has already been loaded, e.g. darwin
109 # Many dynamic extension loading problems will appear to come from
110 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
111 # Often these errors are actually occurring in the initialisation
112 # C code of the extension XS file. Perl reports the error as being
113 # in this perl code simply because this was the last perl code
116 my $libref = dl_load_file($file, 0) or do {
118 Carp::croak("Can't load '$file' for module $module: " . dl_error());
120 push(@DynaLoader::dl_librefs,$libref); # record loaded object
122 my @unresolved = dl_undef_symbols();
125 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
128 $boot_symbol_ref = dl_find_symbol($libref, $bootname) or do {
130 Carp::croak("Can't find '$bootname' symbol in $file\n");
133 push(@DynaLoader::dl_modules, $module); # record loaded module
136 my $xs = dl_install_xsub($boots, $boot_symbol_ref, $file);
138 # See comment block above
139 push(@DynaLoader::dl_shared_objects, $file); # record files loaded
143 my $bootstrap_inherit = DynaLoader->can('bootstrap_inherit') ||
144 XSLoader->can('bootstrap_inherit');
145 goto &$bootstrap_inherit;
148 # Versions of DynaLoader prior to 5.6.0 don't have this function.
149 sub bootstrap_inherit {
153 local *DynaLoader::isa = *{"$module\::ISA"};
154 local @DynaLoader::isa = (@DynaLoader::isa, 'DynaLoader');
155 # Cannot goto due to delocalization. Will report errors on a wrong line?
157 DynaLoader::bootstrap(@_);
167 XSLoader - Dynamically load C libraries into Perl code
178 XSLoader::load 'YourPackage', $YourPackage::VERSION;
182 This module defines a standard I<simplified> interface to the dynamic
183 linking mechanisms available on many platforms. Its primary purpose is
184 to implement cheap automatic dynamic loading of Perl modules.
186 For a more complicated interface, see L<DynaLoader>. Many (most)
187 features of C<DynaLoader> are not implemented in C<XSLoader>, like for
188 example the C<dl_load_flags>, not honored by C<XSLoader>.
190 =head2 Migration from C<DynaLoader>
192 A typical module using L<DynaLoader|DynaLoader> starts like this:
197 our @ISA = qw( OnePackage OtherPackage DynaLoader );
198 our $VERSION = '0.01';
199 bootstrap YourPackage $VERSION;
206 our @ISA = qw( OnePackage OtherPackage );
207 our $VERSION = '0.01';
208 XSLoader::load 'YourPackage', $VERSION;
210 In other words: replace C<require DynaLoader> by C<use XSLoader>, remove
211 C<DynaLoader> from C<@ISA>, change C<bootstrap> by C<XSLoader::load>. Do not
212 forget to quote the name of your package on the C<XSLoader::load> line,
213 and add comma (C<,>) before the arguments (C<$VERSION> above).
215 Of course, if C<@ISA> contained only C<DynaLoader>, there is no need to have
216 the C<@ISA> assignment at all; moreover, if instead of C<our> one uses the
217 more backward-compatible
219 use vars qw($VERSION @ISA);
221 one can remove this reference to C<@ISA> together with the C<@ISA> assignment.
223 If no C<$VERSION> was specified on the C<bootstrap> line, the last line becomes
225 XSLoader::load 'YourPackage';
227 =head2 Backward compatible boilerplate
229 If you want to have your cake and eat it too, you need a more complicated
233 use vars qw($VERSION @ISA);
235 @ISA = qw( OnePackage OtherPackage );
239 XSLoader::load('YourPackage', $VERSION);
243 push @ISA, 'DynaLoader';
244 bootstrap YourPackage $VERSION;
247 The parentheses about C<XSLoader::load()> arguments are needed since we replaced
248 C<use XSLoader> by C<require>, so the compiler does not know that a function
249 C<XSLoader::load()> is present.
251 This boilerplate uses the low-overhead C<XSLoader> if present; if used with
252 an antic Perl which has no C<XSLoader>, it falls back to using C<DynaLoader>.
254 =head1 Order of initialization: early load()
256 I<Skip this section if the XSUB functions are supposed to be called from other
257 modules only; read it only if you call your XSUBs from the code in your module,
258 or have a C<BOOT:> section in your XS file (see L<perlxs/"The BOOT: Keyword">).
259 What is described here is equally applicable to the L<DynaLoader|DynaLoader>
262 A sufficiently complicated module using XS would have both Perl code (defined
263 in F<YourPackage.pm>) and XS code (defined in F<YourPackage.xs>). If this
264 Perl code makes calls into this XS code, and/or this XS code makes calls to
265 the Perl code, one should be careful with the order of initialization.
267 The call to C<XSLoader::load()> (or C<bootstrap()>) has three side effects:
273 if C<$VERSION> was specified, a sanity check is done to ensure that the
274 versions of the F<.pm> and the (compiled) F<.xs> parts are compatible;
278 the XSUBs are made accessible from Perl;
282 if a C<BOOT:> section was present in the F<.xs> file, the code there is called.
286 Consequently, if the code in the F<.pm> file makes calls to these XSUBs, it is
287 convenient to have XSUBs installed before the Perl code is defined; for
288 example, this makes prototypes for XSUBs visible to this Perl code.
289 Alternatively, if the C<BOOT:> section makes calls to Perl functions (or
290 uses Perl variables) defined in the F<.pm> file, they must be defined prior to
291 the call to C<XSLoader::load()> (or C<bootstrap()>).
293 The first situation being much more frequent, it makes sense to rewrite the
298 use vars qw($VERSION @ISA);
301 @ISA = qw( OnePackage OtherPackage );
304 # Put Perl code used in the BOOT: section here
306 XSLoader::load 'YourPackage', $VERSION;
309 # Put Perl code making calls into XSUBs here
311 =head2 The most hairy case
313 If the interdependence of your C<BOOT:> section and Perl code is
314 more complicated than this (e.g., the C<BOOT:> section makes calls to Perl
315 functions which make calls to XSUBs with prototypes), get rid of the C<BOOT:>
316 section altogether. Replace it with a function C<onBOOT()>, and call it like
321 use vars qw($VERSION @ISA);
324 @ISA = qw( OnePackage OtherPackage );
326 XSLoader::load 'YourPackage', $VERSION;
329 # Put Perl code used in onBOOT() function here; calls to XSUBs are
334 # Put Perl initialization code assuming that XS is initialized here
341 =item C<Can't find '%s' symbol in %s>
343 B<(F)> The bootstrap symbol could not be found in the extension module.
345 =item C<Can't load '%s' for module %s: %s>
347 B<(F)> The loading or initialisation of the extension module failed.
348 The detailed error follows.
350 =item C<Undefined symbols present after loading %s: %s>
352 B<(W)> As the message says, some symbols stay undefined although the
353 extension module was correctly loaded and initialised. The list of undefined
356 =item C<XSLoader::load('Your::Module', $Your::Module::VERSION)>
358 B<(F)> You tried to invoke C<load()> without any argument. You must supply
359 a module name, and optionally its version.
366 To reduce the overhead as much as possible, only one possible location
367 is checked to find the extension DLL (this location is where C<make install>
368 would put the DLL). If not found, the search for the DLL is transparently
369 delegated to C<DynaLoader>, which looks for the DLL along the C<@INC> list.
371 In particular, this is applicable to the structure of C<@INC> used for testing
372 not-yet-installed extensions. This means that running uninstalled extensions
373 may have much more overhead than running the same extensions after
379 Please report any bugs or feature requests via the perlbug(1) utility.
389 Ilya Zakharevich originally extracted C<XSLoader> from C<DynaLoader>.
391 CPAN version is currently maintained by SE<eacute>bastien Aperghis-Tramoni
392 E<lt>sebastien@aperghis.netE<gt>.
394 Previous maintainer was Michael G Schwern <schwern@pobox.com>.
397 =head1 COPYRIGHT & LICENSE
399 Copyright (C) 1990-2007 by Larry Wall and others.
401 This program is free software; you can redistribute it and/or modify
402 it under the same terms as Perl itself.