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 $bs) { # only read file if it's not empty
86 warn "$bs: $@\n" if $@;
89 goto retry if not -f $file or -s $bs;
91 my $bootname = "boot_$module";
92 $bootname =~ s/\W/_/g;
93 @DynaLoader::dl_require_symbols = ($bootname);
99 if ($^O eq 'darwin') {
101 if ($boot_symbol_ref = dl_find_symbol(0, $bootname)) {
102 goto boot; #extension library has already been loaded, e.g. darwin
108 # Many dynamic extension loading problems will appear to come from
109 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
110 # Often these errors are actually occurring in the initialisation
111 # C code of the extension XS file. Perl reports the error as being
112 # in this perl code simply because this was the last perl code
115 my $libref = dl_load_file($file, 0) or do {
117 Carp::croak("Can't load '$file' for module $module: " . dl_error());
119 push(@DynaLoader::dl_librefs,$libref); # record loaded object
121 my @unresolved = dl_undef_symbols();
124 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
127 $boot_symbol_ref = dl_find_symbol($libref, $bootname) or do {
129 Carp::croak("Can't find '$bootname' symbol in $file\n");
132 push(@DynaLoader::dl_modules, $module); # record loaded module
135 my $xs = dl_install_xsub($boots, $boot_symbol_ref, $file);
137 # See comment block above
138 push(@DynaLoader::dl_shared_objects, $file); # record files loaded
142 my $bootstrap_inherit = DynaLoader->can('bootstrap_inherit') ||
143 XSLoader->can('bootstrap_inherit');
144 goto &$bootstrap_inherit;
147 # Versions of DynaLoader prior to 5.6.0 don't have this function.
148 sub bootstrap_inherit {
152 local *DynaLoader::isa = *{"$module\::ISA"};
153 local @DynaLoader::isa = (@DynaLoader::isa, 'DynaLoader');
154 # Cannot goto due to delocalization. Will report errors on a wrong line?
156 DynaLoader::bootstrap(@_);
166 XSLoader - Dynamically load C libraries into Perl code
177 XSLoader::load 'YourPackage', $YourPackage::VERSION;
181 This module defines a standard I<simplified> interface to the dynamic
182 linking mechanisms available on many platforms. Its primary purpose is
183 to implement cheap automatic dynamic loading of Perl modules.
185 For a more complicated interface, see L<DynaLoader>. Many (most)
186 features of C<DynaLoader> are not implemented in C<XSLoader>, like for
187 example the C<dl_load_flags>, not honored by C<XSLoader>.
189 =head2 Migration from C<DynaLoader>
191 A typical module using L<DynaLoader|DynaLoader> starts like this:
196 our @ISA = qw( OnePackage OtherPackage DynaLoader );
197 our $VERSION = '0.01';
198 bootstrap YourPackage $VERSION;
205 our @ISA = qw( OnePackage OtherPackage );
206 our $VERSION = '0.01';
207 XSLoader::load 'YourPackage', $VERSION;
209 In other words: replace C<require DynaLoader> by C<use XSLoader>, remove
210 C<DynaLoader> from C<@ISA>, change C<bootstrap> by C<XSLoader::load>. Do not
211 forget to quote the name of your package on the C<XSLoader::load> line,
212 and add comma (C<,>) before the arguments (C<$VERSION> above).
214 Of course, if C<@ISA> contained only C<DynaLoader>, there is no need to have
215 the C<@ISA> assignment at all; moreover, if instead of C<our> one uses the
216 more backward-compatible
218 use vars qw($VERSION @ISA);
220 one can remove this reference to C<@ISA> together with the C<@ISA> assignment.
222 If no C<$VERSION> was specified on the C<bootstrap> line, the last line becomes
224 XSLoader::load 'YourPackage';
226 =head2 Backward compatible boilerplate
228 If you want to have your cake and eat it too, you need a more complicated
232 use vars qw($VERSION @ISA);
234 @ISA = qw( OnePackage OtherPackage );
238 XSLoader::load('YourPackage', $VERSION);
242 push @ISA, 'DynaLoader';
243 bootstrap YourPackage $VERSION;
246 The parentheses about C<XSLoader::load()> arguments are needed since we replaced
247 C<use XSLoader> by C<require>, so the compiler does not know that a function
248 C<XSLoader::load()> is present.
250 This boilerplate uses the low-overhead C<XSLoader> if present; if used with
251 an antic Perl which has no C<XSLoader>, it falls back to using C<DynaLoader>.
253 =head1 Order of initialization: early load()
255 I<Skip this section if the XSUB functions are supposed to be called from other
256 modules only; read it only if you call your XSUBs from the code in your module,
257 or have a C<BOOT:> section in your XS file (see L<perlxs/"The BOOT: Keyword">).
258 What is described here is equally applicable to the L<DynaLoader|DynaLoader>
261 A sufficiently complicated module using XS would have both Perl code (defined
262 in F<YourPackage.pm>) and XS code (defined in F<YourPackage.xs>). If this
263 Perl code makes calls into this XS code, and/or this XS code makes calls to
264 the Perl code, one should be careful with the order of initialization.
266 The call to C<XSLoader::load()> (or C<bootstrap()>) has three side effects:
272 if C<$VERSION> was specified, a sanity check is done to ensure that the
273 versions of the F<.pm> and the (compiled) F<.xs> parts are compatible;
277 the XSUBs are made accessible from Perl;
281 if a C<BOOT:> section was present in the F<.xs> file, the code there is called.
285 Consequently, if the code in the F<.pm> file makes calls to these XSUBs, it is
286 convenient to have XSUBs installed before the Perl code is defined; for
287 example, this makes prototypes for XSUBs visible to this Perl code.
288 Alternatively, if the C<BOOT:> section makes calls to Perl functions (or
289 uses Perl variables) defined in the F<.pm> file, they must be defined prior to
290 the call to C<XSLoader::load()> (or C<bootstrap()>).
292 The first situation being much more frequent, it makes sense to rewrite the
297 use vars qw($VERSION @ISA);
300 @ISA = qw( OnePackage OtherPackage );
303 # Put Perl code used in the BOOT: section here
305 XSLoader::load 'YourPackage', $VERSION;
308 # Put Perl code making calls into XSUBs here
310 =head2 The most hairy case
312 If the interdependence of your C<BOOT:> section and Perl code is
313 more complicated than this (e.g., the C<BOOT:> section makes calls to Perl
314 functions which make calls to XSUBs with prototypes), get rid of the C<BOOT:>
315 section altogether. Replace it with a function C<onBOOT()>, and call it like
320 use vars qw($VERSION @ISA);
323 @ISA = qw( OnePackage OtherPackage );
325 XSLoader::load 'YourPackage', $VERSION;
328 # Put Perl code used in onBOOT() function here; calls to XSUBs are
333 # Put Perl initialization code assuming that XS is initialized here
340 =item C<Can't find '%s' symbol in %s>
342 B<(F)> The bootstrap symbol could not be found in the extension module.
344 =item C<Can't load '%s' for module %s: %s>
346 B<(F)> The loading or initialisation of the extension module failed.
347 The detailed error follows.
349 =item C<Undefined symbols present after loading %s: %s>
351 B<(W)> As the message says, some symbols stay undefined although the
352 extension module was correctly loaded and initialised. The list of undefined
355 =item C<XSLoader::load('Your::Module', $Your::Module::VERSION)>
357 B<(F)> You tried to invoke C<load()> without any argument. You must supply
358 a module name, and optionally its version.
365 To reduce the overhead as much as possible, only one possible location
366 is checked to find the extension DLL (this location is where C<make install>
367 would put the DLL). If not found, the search for the DLL is transparently
368 delegated to C<DynaLoader>, which looks for the DLL along the C<@INC> list.
370 In particular, this is applicable to the structure of C<@INC> used for testing
371 not-yet-installed extensions. This means that running uninstalled extensions
372 may have much more overhead than running the same extensions after
378 Please report any bugs or feature requests via the perlbug(1) utility.
388 Ilya Zakharevich originally extracted C<XSLoader> from C<DynaLoader>.
390 CPAN version is currently maintained by SE<eacute>bastien Aperghis-Tramoni
391 E<lt>sebastien@aperghis.netE<gt>.
393 Previous maintainer was Michael G Schwern <schwern@pobox.com>.
396 =head1 COPYRIGHT & LICENSE
398 Copyright (C) 1990-2007 by Larry Wall and others.
400 This program is free software; you can redistribute it and/or modify
401 it under the same terms as Perl itself.