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1 | use strict; |
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2 | use Config; |
3 | |
4 | sub to_string { |
5 | my ($value) = @_; |
6 | $value =~ s/\\/\\\\/g; |
7 | $value =~ s/'/\\'/g; |
8 | return "'$value'"; |
9 | } |
10 | |
11fd7d05 |
11 | 1 while unlink "XSLoader.pm"; |
9cf41c4d |
12 | open OUT, ">XSLoader.pm" or die $!; |
13 | print OUT <<'EOT'; |
14 | # Generated from XSLoader.pm.PL (resolved %Config::Config value) |
15 | |
16 | package XSLoader; |
17 | |
11fd7d05 |
18 | $VERSION = "0.05_01"; |
19 | |
20 | #use strict; |
9cf41c4d |
21 | |
22 | # enable debug/trace messages from DynaLoader perl code |
23 | # $dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug; |
24 | |
25 | EOT |
26 | |
27 | print OUT ' my $dl_dlext = ', to_string($Config::Config{'dlext'}), ";\n" ; |
28 | |
29 | print OUT <<'EOT'; |
30 | |
9cf41c4d |
31 | package DynaLoader; |
b4cea227 |
32 | |
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 |
9cf41c4d |
35 | boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) && |
b4cea227 |
36 | !defined(&dl_error); |
9cf41c4d |
37 | package XSLoader; |
38 | |
9cf41c4d |
39 | sub load { |
40 | package DynaLoader; |
41 | |
9e8c31cc |
42 | die q{XSLoader::load('Your::Module', $Your::Module::VERSION)} unless @_; |
43 | |
9cf41c4d |
44 | my($module) = $_[0]; |
45 | |
46 | # work with static linking too |
47 | my $b = "$module\::bootstrap"; |
48 | goto &$b if defined &$b; |
49 | |
50 | goto retry unless $module and defined &dl_load_file; |
51 | |
52 | my @modparts = split(/::/,$module); |
53 | my $modfname = $modparts[-1]; |
54 | |
55 | EOT |
56 | |
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; |
62 | |
63 | EOT |
64 | |
65 | print OUT <<'EOT'; |
66 | my $modpname = join('/',@modparts); |
67 | my $modlibname = (caller())[1]; |
68 | my $c = @modparts; |
69 | $modlibname =~ s,[\\/][^\\/]+$,, while $c--; # Q&D basename |
70 | my $file = "$modlibname/auto/$modpname/$modfname.$dl_dlext"; |
71 | |
72 | # print STDERR "XSLoader::load for $module ($file)\n" if $dl_debug; |
73 | |
74 | my $bs = $file; |
75 | $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library |
76 | |
77 | goto retry if not -f $file or -s $bs; |
78 | |
79 | my $bootname = "boot_$module"; |
80 | $bootname =~ s/\W/_/g; |
11fd7d05 |
81 | @DynaLoader::dl_require_symbols = ($bootname); |
9cf41c4d |
82 | |
588cafc8 |
83 | my $boot_symbol_ref; |
84 | |
85 | if ($^O eq 'darwin') { |
86 | if ($boot_symbol_ref = dl_find_symbol(0, $bootname)) { |
87 | goto boot; #extension library has already been loaded, e.g. darwin |
88 | } |
89 | } |
90 | |
9cf41c4d |
91 | # Many dynamic extension loading problems will appear to come from |
92 | # this section of code: XYZ failed at line 123 of DynaLoader.pm. |
93 | # Often these errors are actually occurring in the initialisation |
94 | # C code of the extension XS file. Perl reports the error as being |
95 | # in this perl code simply because this was the last perl code |
96 | # it executed. |
97 | |
98 | my $libref = dl_load_file($file, 0) or do { |
11fd7d05 |
99 | require Carp; |
100 | Carp::croak("Can't load '$file' for module $module: " . dl_error()); |
9cf41c4d |
101 | }; |
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102 | push(@DynaLoader::dl_librefs,$libref); # record loaded object |
9cf41c4d |
103 | |
104 | my @unresolved = dl_undef_symbols(); |
105 | if (@unresolved) { |
11fd7d05 |
106 | require Carp; |
107 | Carp::carp("Undefined symbols present after loading $file: @unresolved\n"); |
9cf41c4d |
108 | } |
109 | |
588cafc8 |
110 | $boot_symbol_ref = dl_find_symbol($libref, $bootname) or do { |
11fd7d05 |
111 | require Carp; |
112 | Carp::croak("Can't find '$bootname' symbol in $file\n"); |
9cf41c4d |
113 | }; |
114 | |
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115 | push(@DynaLoader::dl_modules, $module); # record loaded module |
9cf41c4d |
116 | |
588cafc8 |
117 | boot: |
118 | my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file); |
119 | |
9cf41c4d |
120 | # See comment block above |
89166d32 |
121 | push(@DynaLoader::dl_shared_objects, $file); # record files loaded |
9cf41c4d |
122 | return &$xs(@_); |
123 | |
124 | retry: |
11fd7d05 |
125 | my $bootstrap_inherit = DynaLoader->can('bootstrap_inherit') || |
126 | XSLoader->can('bootstrap_inherit'); |
127 | goto &$bootstrap_inherit; |
128 | } |
129 | |
130 | # Versions of DynaLoader prior to 5.6.0 don't have this function. |
131 | sub bootstrap_inherit { |
132 | package DynaLoader; |
133 | |
134 | my $module = $_[0]; |
135 | local *DynaLoader::isa = *{"$module\::ISA"}; |
136 | local @DynaLoader::isa = (@DynaLoader::isa, 'DynaLoader'); |
137 | # Cannot goto due to delocalization. Will report errors on a wrong line? |
9cf41c4d |
138 | require DynaLoader; |
11fd7d05 |
139 | DynaLoader::bootstrap(@_); |
9cf41c4d |
140 | } |
141 | |
9e8c31cc |
142 | 1; |
143 | |
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144 | |
9cf41c4d |
145 | __END__ |
146 | |
147 | =head1 NAME |
148 | |
149 | XSLoader - Dynamically load C libraries into Perl code |
150 | |
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151 | =head1 VERSION |
152 | |
153 | Version 0.05_01 |
154 | |
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155 | =head1 SYNOPSIS |
156 | |
157 | package YourPackage; |
158 | use XSLoader; |
159 | |
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160 | XSLoader::load 'YourPackage', $YourPackage::VERSION; |
9cf41c4d |
161 | |
162 | =head1 DESCRIPTION |
163 | |
164 | This module defines a standard I<simplified> interface to the dynamic |
165 | linking mechanisms available on many platforms. Its primary purpose is |
166 | to implement cheap automatic dynamic loading of Perl modules. |
167 | |
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168 | For a more complicated interface, see L<DynaLoader>. Many (most) |
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169 | features of C<DynaLoader> are not implemented in C<XSLoader>, like for |
170 | example the C<dl_load_flags>, not honored by C<XSLoader>. |
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171 | |
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172 | =head2 Migration from C<DynaLoader> |
173 | |
174 | A typical module using L<DynaLoader|DynaLoader> starts like this: |
175 | |
176 | package YourPackage; |
177 | require DynaLoader; |
178 | |
179 | our @ISA = qw( OnePackage OtherPackage DynaLoader ); |
180 | our $VERSION = '0.01'; |
181 | bootstrap YourPackage $VERSION; |
182 | |
183 | Change this to |
184 | |
185 | package YourPackage; |
186 | use XSLoader; |
187 | |
188 | our @ISA = qw( OnePackage OtherPackage ); |
189 | our $VERSION = '0.01'; |
190 | XSLoader::load 'YourPackage', $VERSION; |
191 | |
192 | In other words: replace C<require DynaLoader> by C<use XSLoader>, remove |
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193 | C<DynaLoader> from C<@ISA>, change C<bootstrap> by C<XSLoader::load>. Do not |
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194 | forget to quote the name of your package on the C<XSLoader::load> line, |
195 | and add comma (C<,>) before the arguments ($VERSION above). |
196 | |
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197 | Of course, if C<@ISA> contained only C<DynaLoader>, there is no need to have |
198 | the C<@ISA> assignment at all; moreover, if instead of C<our> one uses the |
199 | more backward-compatible |
d7f44de2 |
200 | |
201 | use vars qw($VERSION @ISA); |
202 | |
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203 | one can remove this reference to C<@ISA> together with the C<@ISA> assignment. |
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204 | |
11fd7d05 |
205 | If no C<$VERSION> was specified on the C<bootstrap> line, the last line becomes |
d7f44de2 |
206 | |
207 | XSLoader::load 'YourPackage'; |
208 | |
209 | =head2 Backward compatible boilerplate |
210 | |
211 | If you want to have your cake and eat it too, you need a more complicated |
212 | boilerplate. |
213 | |
214 | package YourPackage; |
215 | use vars qw($VERSION @ISA); |
216 | |
217 | @ISA = qw( OnePackage OtherPackage ); |
218 | $VERSION = '0.01'; |
219 | eval { |
220 | require XSLoader; |
221 | XSLoader::load('YourPackage', $VERSION); |
222 | 1; |
223 | } or do { |
224 | require DynaLoader; |
225 | push @ISA, 'DynaLoader'; |
226 | bootstrap YourPackage $VERSION; |
227 | }; |
228 | |
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229 | The parentheses about C<XSLoader::load()> arguments are needed since we replaced |
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230 | C<use XSLoader> by C<require>, so the compiler does not know that a function |
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231 | C<XSLoader::load()> is present. |
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232 | |
233 | This boilerplate uses the low-overhead C<XSLoader> if present; if used with |
234 | an antic Perl which has no C<XSLoader>, it falls back to using C<DynaLoader>. |
235 | |
236 | =head1 Order of initialization: early load() |
237 | |
238 | I<Skip this section if the XSUB functions are supposed to be called from other |
239 | modules only; read it only if you call your XSUBs from the code in your module, |
240 | or have a C<BOOT:> section in your XS file (see L<perlxs/"The BOOT: Keyword">). |
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241 | What is described here is equally applicable to the L<DynaLoader|DynaLoader> |
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242 | interface.> |
243 | |
244 | A sufficiently complicated module using XS would have both Perl code (defined |
245 | in F<YourPackage.pm>) and XS code (defined in F<YourPackage.xs>). If this |
246 | Perl code makes calls into this XS code, and/or this XS code makes calls to |
247 | the Perl code, one should be careful with the order of initialization. |
248 | |
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249 | The call to C<XSLoader::load()> (or C<bootstrap()>) has three side effects: |
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250 | |
251 | =over |
252 | |
253 | =item * |
254 | |
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255 | if C<$VERSION> was specified, a sanity check is done to ensure that the |
256 | versions of the F<.pm> and the (compiled) F<.xs> parts are compatible; |
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257 | |
258 | =item * |
259 | |
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260 | the XSUBs are made accessible from Perl; |
d7f44de2 |
261 | |
262 | =item * |
263 | |
4406dda9 |
264 | if a C<BOOT:> section was present in the F<.xs> file, the code there is called. |
d7f44de2 |
265 | |
266 | =back |
267 | |
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268 | Consequently, if the code in the F<.pm> file makes calls to these XSUBs, it is |
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269 | convenient to have XSUBs installed before the Perl code is defined; for |
270 | example, this makes prototypes for XSUBs visible to this Perl code. |
271 | Alternatively, if the C<BOOT:> section makes calls to Perl functions (or |
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272 | uses Perl variables) defined in the F<.pm> file, they must be defined prior to |
11fd7d05 |
273 | the call to C<XSLoader::load()> (or C<bootstrap()>). |
d7f44de2 |
274 | |
275 | The first situation being much more frequent, it makes sense to rewrite the |
276 | boilerplate as |
277 | |
278 | package YourPackage; |
279 | use XSLoader; |
280 | use vars qw($VERSION @ISA); |
281 | |
282 | BEGIN { |
283 | @ISA = qw( OnePackage OtherPackage ); |
284 | $VERSION = '0.01'; |
285 | |
286 | # Put Perl code used in the BOOT: section here |
287 | |
288 | XSLoader::load 'YourPackage', $VERSION; |
289 | } |
290 | |
291 | # Put Perl code making calls into XSUBs here |
292 | |
293 | =head2 The most hairy case |
294 | |
295 | If the interdependence of your C<BOOT:> section and Perl code is |
296 | more complicated than this (e.g., the C<BOOT:> section makes calls to Perl |
297 | functions which make calls to XSUBs with prototypes), get rid of the C<BOOT:> |
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298 | section altogether. Replace it with a function C<onBOOT()>, and call it like |
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299 | this: |
300 | |
301 | package YourPackage; |
302 | use XSLoader; |
303 | use vars qw($VERSION @ISA); |
304 | |
305 | BEGIN { |
306 | @ISA = qw( OnePackage OtherPackage ); |
307 | $VERSION = '0.01'; |
308 | XSLoader::load 'YourPackage', $VERSION; |
309 | } |
310 | |
311 | # Put Perl code used in onBOOT() function here; calls to XSUBs are |
312 | # prototype-checked. |
313 | |
314 | onBOOT; |
315 | |
316 | # Put Perl initialization code assuming that XS is initialized here |
317 | |
11fd7d05 |
318 | |
319 | =head1 DIAGNOSTICS |
320 | |
321 | =over 4 |
322 | |
323 | =item Can't find '%s' symbol in %s |
324 | |
325 | B<(F)> The bootstrap symbol could not be found in the extension module. |
326 | |
327 | =item Can't load '%s' for module %s: %s |
328 | |
329 | B<(F)> The loading or initialisation of the extension module failed. |
330 | The detailed error follows. |
331 | |
332 | =item Undefined symbols present after loading %s: %s |
333 | |
334 | B<(W)> As the message says, some symbols stay undefined although the |
335 | extension module was correctly loaded and initialised. The list of undefined |
336 | symbols follows. |
337 | |
338 | =item XSLoader::load('Your::Module', $Your::Module::VERSION) |
339 | |
340 | B<(F)> You tried to invoke C<load()> without any argument. You must supply |
341 | a module name, and optionally its version. |
342 | |
343 | =back |
344 | |
345 | |
d7f44de2 |
346 | =head1 LIMITATIONS |
347 | |
348 | To reduce the overhead as much as possible, only one possible location |
349 | is checked to find the extension DLL (this location is where C<make install> |
350 | would put the DLL). If not found, the search for the DLL is transparently |
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351 | delegated to C<DynaLoader>, which looks for the DLL along the C<@INC> list. |
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352 | |
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353 | In particular, this is applicable to the structure of C<@INC> used for testing |
4406dda9 |
354 | not-yet-installed extensions. This means that running uninstalled extensions |
355 | may have much more overhead than running the same extensions after |
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356 | C<make install>. |
357 | |
11fd7d05 |
358 | |
359 | =head1 BUGS |
360 | |
361 | Please report any bugs or feature requests via the perlbug(1) |
362 | utility. |
363 | |
364 | |
365 | =head1 SEE ALSO |
366 | |
367 | L<DynaLoader> |
368 | |
369 | |
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370 | =head1 AUTHOR |
371 | |
11fd7d05 |
372 | Ilya Zakharevich originally extracted C<XSLoader> from C<DynaLoader>. |
373 | |
374 | CPAN version is currently maintained by SE<eacute>bastien Aperghis-Tramoni |
375 | E<lt>sebastien@aperghis.netE<gt> |
376 | |
377 | Previous maintainer was Michael G Schwern <schwern@pobox.com> |
378 | |
379 | |
380 | =head1 COPYRIGHT |
381 | |
382 | This program is free software; you can redistribute it and/or modify |
383 | it under the same terms as Perl itself. |
9cf41c4d |
384 | |
385 | =cut |
386 | EOT |
387 | |
388 | close OUT or die $!; |