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 $b = "$module\::bootstrap";
48 goto &$b if defined &$b;
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 goto retry if not -f $file or -s $bs;
86 my $bootname = "boot_$module";
87 $bootname =~ s/\W/_/g;
88 @DynaLoader::dl_require_symbols = ($bootname);
94 if ($^O eq 'darwin') {
96 if ($boot_symbol_ref = dl_find_symbol(0, $bootname)) {
97 goto boot; #extension library has already been loaded, e.g. darwin
103 # Many dynamic extension loading problems will appear to come from
104 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
105 # Often these errors are actually occurring in the initialisation
106 # C code of the extension XS file. Perl reports the error as being
107 # in this perl code simply because this was the last perl code
110 my $libref = dl_load_file($file, 0) or do {
112 Carp::croak("Can't load '$file' for module $module: " . dl_error());
114 push(@DynaLoader::dl_librefs,$libref); # record loaded object
116 my @unresolved = dl_undef_symbols();
119 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
122 $boot_symbol_ref = dl_find_symbol($libref, $bootname) or do {
124 Carp::croak("Can't find '$bootname' symbol in $file\n");
127 push(@DynaLoader::dl_modules, $module); # record loaded module
130 my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
132 # See comment block above
133 push(@DynaLoader::dl_shared_objects, $file); # record files loaded
137 my $bootstrap_inherit = DynaLoader->can('bootstrap_inherit') ||
138 XSLoader->can('bootstrap_inherit');
139 goto &$bootstrap_inherit;
142 # Versions of DynaLoader prior to 5.6.0 don't have this function.
143 sub bootstrap_inherit {
147 local *DynaLoader::isa = *{"$module\::ISA"};
148 local @DynaLoader::isa = (@DynaLoader::isa, 'DynaLoader');
149 # Cannot goto due to delocalization. Will report errors on a wrong line?
151 DynaLoader::bootstrap(@_);
161 XSLoader - Dynamically load C libraries into Perl code
172 XSLoader::load 'YourPackage', $YourPackage::VERSION;
176 This module defines a standard I<simplified> interface to the dynamic
177 linking mechanisms available on many platforms. Its primary purpose is
178 to implement cheap automatic dynamic loading of Perl modules.
180 For a more complicated interface, see L<DynaLoader>. Many (most)
181 features of C<DynaLoader> are not implemented in C<XSLoader>, like for
182 example the C<dl_load_flags>, not honored by C<XSLoader>.
184 =head2 Migration from C<DynaLoader>
186 A typical module using L<DynaLoader|DynaLoader> starts like this:
191 our @ISA = qw( OnePackage OtherPackage DynaLoader );
192 our $VERSION = '0.01';
193 bootstrap YourPackage $VERSION;
200 our @ISA = qw( OnePackage OtherPackage );
201 our $VERSION = '0.01';
202 XSLoader::load 'YourPackage', $VERSION;
204 In other words: replace C<require DynaLoader> by C<use XSLoader>, remove
205 C<DynaLoader> from C<@ISA>, change C<bootstrap> by C<XSLoader::load>. Do not
206 forget to quote the name of your package on the C<XSLoader::load> line,
207 and add comma (C<,>) before the arguments (C<$VERSION> above).
209 Of course, if C<@ISA> contained only C<DynaLoader>, there is no need to have
210 the C<@ISA> assignment at all; moreover, if instead of C<our> one uses the
211 more backward-compatible
213 use vars qw($VERSION @ISA);
215 one can remove this reference to C<@ISA> together with the C<@ISA> assignment.
217 If no C<$VERSION> was specified on the C<bootstrap> line, the last line becomes
219 XSLoader::load 'YourPackage';
221 =head2 Backward compatible boilerplate
223 If you want to have your cake and eat it too, you need a more complicated
227 use vars qw($VERSION @ISA);
229 @ISA = qw( OnePackage OtherPackage );
233 XSLoader::load('YourPackage', $VERSION);
237 push @ISA, 'DynaLoader';
238 bootstrap YourPackage $VERSION;
241 The parentheses about C<XSLoader::load()> arguments are needed since we replaced
242 C<use XSLoader> by C<require>, so the compiler does not know that a function
243 C<XSLoader::load()> is present.
245 This boilerplate uses the low-overhead C<XSLoader> if present; if used with
246 an antic Perl which has no C<XSLoader>, it falls back to using C<DynaLoader>.
248 =head1 Order of initialization: early load()
250 I<Skip this section if the XSUB functions are supposed to be called from other
251 modules only; read it only if you call your XSUBs from the code in your module,
252 or have a C<BOOT:> section in your XS file (see L<perlxs/"The BOOT: Keyword">).
253 What is described here is equally applicable to the L<DynaLoader|DynaLoader>
256 A sufficiently complicated module using XS would have both Perl code (defined
257 in F<YourPackage.pm>) and XS code (defined in F<YourPackage.xs>). If this
258 Perl code makes calls into this XS code, and/or this XS code makes calls to
259 the Perl code, one should be careful with the order of initialization.
261 The call to C<XSLoader::load()> (or C<bootstrap()>) has three side effects:
267 if C<$VERSION> was specified, a sanity check is done to ensure that the
268 versions of the F<.pm> and the (compiled) F<.xs> parts are compatible;
272 the XSUBs are made accessible from Perl;
276 if a C<BOOT:> section was present in the F<.xs> file, the code there is called.
280 Consequently, if the code in the F<.pm> file makes calls to these XSUBs, it is
281 convenient to have XSUBs installed before the Perl code is defined; for
282 example, this makes prototypes for XSUBs visible to this Perl code.
283 Alternatively, if the C<BOOT:> section makes calls to Perl functions (or
284 uses Perl variables) defined in the F<.pm> file, they must be defined prior to
285 the call to C<XSLoader::load()> (or C<bootstrap()>).
287 The first situation being much more frequent, it makes sense to rewrite the
292 use vars qw($VERSION @ISA);
295 @ISA = qw( OnePackage OtherPackage );
298 # Put Perl code used in the BOOT: section here
300 XSLoader::load 'YourPackage', $VERSION;
303 # Put Perl code making calls into XSUBs here
305 =head2 The most hairy case
307 If the interdependence of your C<BOOT:> section and Perl code is
308 more complicated than this (e.g., the C<BOOT:> section makes calls to Perl
309 functions which make calls to XSUBs with prototypes), get rid of the C<BOOT:>
310 section altogether. Replace it with a function C<onBOOT()>, and call it like
315 use vars qw($VERSION @ISA);
318 @ISA = qw( OnePackage OtherPackage );
320 XSLoader::load 'YourPackage', $VERSION;
323 # Put Perl code used in onBOOT() function here; calls to XSUBs are
328 # Put Perl initialization code assuming that XS is initialized here
335 =item C<Can't find '%s' symbol in %s>
337 B<(F)> The bootstrap symbol could not be found in the extension module.
339 =item C<Can't load '%s' for module %s: %s>
341 B<(F)> The loading or initialisation of the extension module failed.
342 The detailed error follows.
344 =item C<Undefined symbols present after loading %s: %s>
346 B<(W)> As the message says, some symbols stay undefined although the
347 extension module was correctly loaded and initialised. The list of undefined
350 =item C<XSLoader::load('Your::Module', $Your::Module::VERSION)>
352 B<(F)> You tried to invoke C<load()> without any argument. You must supply
353 a module name, and optionally its version.
360 To reduce the overhead as much as possible, only one possible location
361 is checked to find the extension DLL (this location is where C<make install>
362 would put the DLL). If not found, the search for the DLL is transparently
363 delegated to C<DynaLoader>, which looks for the DLL along the C<@INC> list.
365 In particular, this is applicable to the structure of C<@INC> used for testing
366 not-yet-installed extensions. This means that running uninstalled extensions
367 may have much more overhead than running the same extensions after
373 Please report any bugs or feature requests via the perlbug(1) utility.
383 Ilya Zakharevich originally extracted C<XSLoader> from C<DynaLoader>.
385 CPAN version is currently maintained by SE<eacute>bastien Aperghis-Tramoni
386 E<lt>sebastien@aperghis.netE<gt>.
388 Previous maintainer was Michael G Schwern <schwern@pobox.com>.
393 This program is free software; you can redistribute it and/or modify
394 it under the same terms as Perl itself.