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remove XSLoader and DynaLoader OS specific code on NA OSes
[perl5.git] / ext / DynaLoader / DynaLoader_pm.PL
CommitLineData
03c9e98c
GS
1use Config;
2
3sub to_string {
4 my ($value) = @_;
146174a9 5 $value =~ s/\\/\\\\/g;
03c9e98c
GS
6 $value =~ s/'/\\'/g;
7 return "'$value'";
8}
9
1c7f9087
VK
10#
11# subroutine expand_os_specific expands $^O-specific preprocessing information
12# so that it will not be re-calculated at runtime in Dynaloader.pm
13#
14# Syntax of preprocessor should be kept extremely simple:
15# - directives are in double angle brackets <<...>>
16# - <<=string>> will be just evaluated
17# - for $^O-specific there are two forms:
18# <<$^O-eq-osname>>
19# <<$^O-ne-osname>>
20# this directive should be closed with respectively
21# <</$^O-eq-osname>>
22# <</$^O-ne-osname>>
23# construct <<|$^O-ne-osname>> means #else
24# nested <<$^O...>>-constructs are allowed but nested values must be for
25# different OS-names!
26#
27# -- added by VKON, 03-10-2004 to separate $^O-specific between OSes
28# (so that Win32 never checks for $^O eq 'VMS' for example)
27da23d5
JH
29#
30# The $^O tests test both for $^O and for $Config{osname}.
31# The latter is better for some for cross-compilation setups.
32#
1c7f9087
VK
33sub expand_os_specific {
34 my $s = shift;
35 for ($s) {
36 s/<<=(.*?)>>/$1/gee;
37 s/<<\$\^O-(eq|ne)-(\w+)>>(.*?)<<\/\$\^O-\1-\2>>/
38 my ($op, $os, $expr) = ($1,$2,$3);
39 if ($op ne 'eq' and $op ne 'ne') {die "wrong eq-ne arg in $&"};
40 if ($expr =~ m[^(.*?)<<\|\$\^O-$op-$os>>(.*?)$]s) {
41 # #if;#else;#endif
42 my ($if,$el) = ($1,$2);
27da23d5 43 if (($op eq 'eq' and ($^O eq $os || $Config{osname} eq $os)) || ($op eq 'ne' and ($^O ne $os || $Config{osname} ne $os))) {
1c7f9087
VK
44 $if
45 }
46 else {
47 $el
48 }
49 }
50 else {
51 # #if;#endif
27da23d5 52 if (($op eq 'eq' and ($^O eq $os || $Config{osname} eq $os)) || ($op eq 'ne' and ($^O ne $os || $Config{osname} ne $os))) {
1c7f9087
VK
53 $expr
54 }
55 else {
56 ""
57 }
58 }
59 /ges;
60 if (/<<(=|\$\^O-)/) {die "bad <<\$^O-eq/ne-osname>> expression.".
61 " Unclosed brackets?";
62 }
63 }
64 $s;
65}
66
03c9e98c
GS
67unlink "DynaLoader.pm" if -f "DynaLoader.pm";
68open OUT, ">DynaLoader.pm" or die $!;
69print OUT <<'EOT';
70
f24427cc 71# Generated from DynaLoader_pm.PL, this file is unique for every OS
03c9e98c 72
a0d0e21e
LW
73package DynaLoader;
74
8e07c86e
AD
75# And Gandalf said: 'Many folk like to know beforehand what is to
76# be set on the table; but those who have laboured to prepare the
77# feast like to keep their secret; for wonder makes the words of
78# praise louder.'
79
6662521e 80# (Quote from Tolkien suggested by Anno Siegel.)
8e07c86e
AD
81#
82# See pod text at end of file for documentation.
83# See also ext/DynaLoader/README in source tree for other information.
84#
85# Tim.Bunce@ig.co.uk, August 1994
86
e240c90c 87BEGIN {
f24427cc 88 $VERSION = '1.36';
e240c90c 89}
dc848c6f 90
d2a92727
TR
91EOT
92
93if (!$ENV{PERL_BUILD_EXPAND_CONFIG_VARS}) {
94 print OUT "use Config;\n";
95}
96
97print OUT <<'EOT';
7e9f3af8 98
8e07c86e
AD
99# enable debug/trace messages from DynaLoader perl code
100$dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
101
ff7f3c60
NIS
102#
103# Flags to alter dl_load_file behaviour. Assigned bits:
104# 0x01 make symbols available for linking later dl_load_file's.
105# (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
f86702cc 106# (ignored under VMS; effect is built-in to image linking)
dec98916 107# (ignored under Android; the linker always uses RTLD_LOCAL)
ff7f3c60
NIS
108#
109# This is called as a class method $module->dl_load_flags. The
110# definition here will be inherited and result on "default" loading
111# behaviour unless a sub-class of DynaLoader defines its own version.
112#
113
114sub dl_load_flags { 0x00 }
115
03c9e98c
GS
116EOT
117
37589e1e
JD
118if ($ENV{PERL_BUILD_EXPAND_CONFIG_VARS}) {
119 print OUT "(\$dl_dlext, \$dl_so, \$dlsrc) = (",
120 to_string($Config{'dlext'}), ",",
121 to_string($Config{'so'}), ",",
122 to_string($Config{'dlsrc'}), ")\n;" ;
123}
124else {
125 print OUT <<'EOT';
126($dl_dlext, $dl_so, $dlsrc) = @Config::Config{qw(dlext so dlsrc)};
127EOT
128}
ff7f3c60 129
1c7f9087 130print OUT expand_os_specific(<<'EOT');
8e07c86e 131
1c7f9087 132<<$^O-eq-VMS>>
8e07c86e
AD
133# Some systems need special handling to expand file specifications
134# (VMS support by Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>)
135# See dl_expandspec() for more details. Should be harmless but
136# inefficient to define on systems that don't need it.
632a9a7f 137$Is_VMS = $^O eq 'VMS';
1c7f9087
VK
138<</$^O-eq-VMS>>
139$do_expand = <<$^O-eq-VMS>>1<<|$^O-eq-VMS>>0<</$^O-eq-VMS>>;
8e07c86e 140
f24427cc
DD
141@dl_require_symbols = (); # names of symbols we need<<$^O-eq-freemint>>
142@dl_resolve_using = (); # names of files to link with<</$^O-eq-freemint>><<$^O-eq-hpux>>
143@dl_resolve_using = (); # names of files to link with<</$^O-eq-hpux>>
8e07c86e 144@dl_library_path = (); # path to look for files
bff25830
DM
145
146#XSLoader.pm may have added elements before we were required
89166d32 147#@dl_shared_objects = (); # shared objects for symbols we have
bff25830
DM
148#@dl_librefs = (); # things we have loaded
149#@dl_modules = (); # Modules we have loaded
8e07c86e 150
d0a5ed9f 151EOT
03c9e98c 152
d0a5ed9f 153my $cfg_dl_library_path = <<'EOT';
632a9a7f 154push(@dl_library_path, split(' ', $Config::Config{libpth}));
03c9e98c
GS
155EOT
156
d0a5ed9f 157sub dquoted_comma_list {
1c7f9087 158 join(", ", map {'"'.quotemeta($_).'"'} @_);
d0a5ed9f 159}
03c9e98c 160
d0a5ed9f
JH
161if ($ENV{PERL_BUILD_EXPAND_CONFIG_VARS}) {
162 eval $cfg_dl_library_path;
163 if (!$ENV{PERL_BUILD_EXPAND_ENV_VARS}) {
164 my $dl_library_path = dquoted_comma_list(@dl_library_path);
165 print OUT <<EOT;
7e9f3af8 166# The below \@dl_library_path has been expanded (%Config) in Perl build time.
d0a5ed9f
JH
167
168\@dl_library_path = ($dl_library_path);
169
170EOT
171 }
172}
173else {
174 print OUT <<EOT;
175# Initialise \@dl_library_path with the 'standard' library path
176# for this platform as determined by Configure.
177
178$cfg_dl_library_path
179
180EOT
181}
8e07c86e 182
8225e35f 183my $ldlibpthname;
7e9f3af8 184my $ldlibpthname_defined;
8225e35f
JH
185my $pthsep;
186
187if ($ENV{PERL_BUILD_EXPAND_CONFIG_VARS}) {
1c7f9087
VK
188 $ldlibpthname = to_string($Config::Config{ldlibpthname});
189 $ldlibpthname_defined = to_string(defined $Config::Config{ldlibpthname} ? 1 : 0);
190 $pthsep = to_string($Config::Config{path_sep});
8225e35f
JH
191}
192else {
7e9f3af8
JH
193 $ldlibpthname = q($Config::Config{ldlibpthname});
194 $ldlibpthname_defined = q(defined $Config::Config{ldlibpthname});
195 $pthsep = q($Config::Config{path_sep});
1c7f9087
VK
196}
197print OUT <<EOT;
7e9f3af8
JH
198my \$ldlibpthname = $ldlibpthname;
199my \$ldlibpthname_defined = $ldlibpthname_defined;
200my \$pthsep = $pthsep;
8225e35f
JH
201
202EOT
8225e35f 203
7e9f3af8
JH
204my $env_dl_library_path = <<'EOT';
205if ($ldlibpthname_defined &&
206 exists $ENV{$ldlibpthname}) {
207 push(@dl_library_path, split(/$pthsep/, $ENV{$ldlibpthname}));
8225e35f
JH
208}
209
5cf1d1f1 210# E.g. HP-UX supports both its native SHLIB_PATH *and* LD_LIBRARY_PATH.
8225e35f 211
7e9f3af8
JH
212if ($ldlibpthname_defined &&
213 $ldlibpthname ne 'LD_LIBRARY_PATH' &&
214 exists $ENV{LD_LIBRARY_PATH}) {
215 push(@dl_library_path, split(/$pthsep/, $ENV{LD_LIBRARY_PATH}));
d0a5ed9f 216}
e6197cab
NC
217EOT
218
d0a5ed9f
JH
219if ($ENV{PERL_BUILD_EXPAND_CONFIG_VARS} && $ENV{PERL_BUILD_EXPAND_ENV_VARS}) {
220 eval $env_dl_library_path;
e6197cab 221}
d0a5ed9f
JH
222else {
223 print OUT <<EOT;
224# Add to \@dl_library_path any extra directories we can gather from environment
225# during runtime.
e6197cab 226
d0a5ed9f
JH
227$env_dl_library_path
228
229EOT
e6197cab
NC
230}
231
d0a5ed9f
JH
232if ($ENV{PERL_BUILD_EXPAND_CONFIG_VARS} && $ENV{PERL_BUILD_EXPAND_ENV_VARS}) {
233 my $dl_library_path = dquoted_comma_list(@dl_library_path);
234 print OUT <<EOT;
7e9f3af8
JH
235# The below \@dl_library_path has been expanded (%Config, %ENV)
236# in Perl build time.
d0a5ed9f
JH
237
238\@dl_library_path = ($dl_library_path);
239
240EOT
146174a9 241}
8e07c86e 242
adedc077 243if ( $Config::Config{d_libname_unique} ) {
7ba225ea 244 printf OUT <<'EOT', length($Config::Config{dlext}) + 1;
adedc077
BF
245sub mod2fname {
246 my $parts = shift;
7ba225ea 247 my $so_len = %d;
adedc077
BF
248 my $name_max = 255; # No easy way to get this here
249
250 my $libname = "PL_" . join("__", @$parts);
251
252 return $libname if (length($libname)+$so_len) <= $name_max;
253
254 # It's too darned big, so we need to go strip. We use the same
255 # algorithm as xsubpp does. First, strip out doubled __
256 $libname =~ s/__/_/g;
257 return $libname if (length($libname)+$so_len) <= $name_max;
258
259 # Strip duplicate letters
260 1 while $libname =~ s/(.)\1/\U$1/i;
261 return $libname if (length($libname)+$so_len) <= $name_max;
262
263 # Still too long. Truncate.
264 $libname = substr($libname, 0, $name_max - $so_len);
265 return $libname;
266}
267EOT
268}
1c7f9087
VK
269
270# following long string contains $^O-specific stuff, which is factored out
271print OUT expand_os_specific(<<'EOT');
8e07c86e 272# No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
b4cea227 273# NOTE: All dl_*.xs (including dl_none.xs) define a dl_error() XSUB
bb3913c7 274boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
b4cea227 275 !defined(&dl_error);
8e07c86e
AD
276
277if ($dl_debug) {
278 print STDERR "DynaLoader.pm loaded (@INC, @dl_library_path)\n";
279 print STDERR "DynaLoader not linked into this perl\n"
280 unless defined(&boot_DynaLoader);
281}
282
2831; # End of main code
284
285
fb73857a
PP
286sub croak { require Carp; Carp::croak(@_) }
287
146174a9
CB
288sub bootstrap_inherit {
289 my $module = $_[0];
290 local *isa = *{"$module\::ISA"};
291 local @isa = (@isa, 'DynaLoader');
292 # Cannot goto due to delocalization. Will report errors on a wrong line?
293 bootstrap(@_);
294}
295
8e07c86e
AD
296sub bootstrap {
297 # use local vars to enable $module.bs script to edit values
298 local(@args) = @_;
299 local($module) = $args[0];
300 local(@dirs, $file);
301
fb73857a
PP
302 unless ($module) {
303 require Carp;
304 Carp::confess("Usage: DynaLoader::bootstrap(module)");
305 }
8e07c86e
AD
306
307 # A common error on platforms which don't support dynamic loading.
308 # Since it's fatal and potentially confusing we give a detailed message.
fb73857a 309 croak("Can't load module $module, dynamic loading not available in this perl.\n".
8e07c86e
AD
310 " (You may need to build a new perl executable which either supports\n".
311 " dynamic loading or has the $module module statically linked into it.)\n")
312 unless defined(&dl_load_file);
313
59ad941d 314
1c7f9087 315 <<$^O-eq-os2>>
59ad941d
IZ
316 # Can dynaload, but cannot dynaload Perl modules...
317 die 'Dynaloaded Perl modules are not available in this build of Perl' if $OS2::is_static;
318
1c7f9087 319 <</$^O-eq-os2>>
8e07c86e
AD
320 my @modparts = split(/::/,$module);
321 my $modfname = $modparts[-1];
322
323 # Some systems have restrictions on files names for DLL's etc.
324 # mod2fname returns appropriate file base name (typically truncated)
325 # It may also edit @modparts if required.
326 $modfname = &mod2fname(\@modparts) if defined &mod2fname;
327
1c7f9087 328 <<$^O-eq-NetWare>>
1a95e36d 329 # Truncate the module name to 8.3 format for NetWare
1c7f9087 330 if ((length($modfname) > 8)) {
f355267c
JH
331 $modfname = substr($modfname, 0, 8);
332 }
1c7f9087 333 <</$^O-eq-NetWare>>
f355267c 334
c457df04 335 my $modpname = join('/',@modparts);
8e07c86e
AD
336
337 print STDERR "DynaLoader::bootstrap for $module ",
c457df04 338 "(auto/$modpname/$modfname.$dl_dlext)\n"
146174a9 339 if $dl_debug;
8e07c86e
AD
340
341 foreach (@INC) {
1c7f9087 342 <<$^O-eq-VMS>>chop($_ = VMS::Filespec::unixpath($_));<</$^O-eq-VMS>>
1c7f9087 343 my $dir = "$_/auto/$modpname";
1a95e36d
JH
344
345 next unless -d $dir; # skip over uninteresting directories
346
8e07c86e 347 # check for common cases to avoid autoload of dl_findfile
adedc077 348 my $try = "$dir/$modfname.$dl_dlext";
444c2e40 349 last if $file = ($do_expand) ? dl_expandspec($try) : ((-f $try) && $try);
1a95e36d 350
8e07c86e 351 # no luck here, save dir for possible later dl_findfile search
fb73857a 352 push @dirs, $dir;
8e07c86e
AD
353 }
354 # last resort, let dl_findfile have a go in all known locations
fb73857a 355 $file = dl_findfile(map("-L$_",@dirs,@INC), $modfname) unless $file;
8e07c86e 356
fb73857a
PP
357 croak("Can't locate loadable object for module $module in \@INC (\@INC contains: @INC)")
358 unless $file; # wording similar to error from 'require'
8e07c86e 359
1c7f9087 360 <<$^O-eq-VMS>>$file = uc($file) if $Config::Config{d_vms_case_sensitive_symbols};<</$^O-eq-VMS>>
8e07c86e
AD
361 my $bootname = "boot_$module";
362 $bootname =~ s/\W/_/g;
363 @dl_require_symbols = ($bootname);
364
365 # Execute optional '.bootstrap' perl script for this module.
366 # The .bs file can be used to configure @dl_resolve_using etc to
367 # match the needs of the individual module on this architecture.
368 my $bs = $file;
3f45a6dd 369 $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
8e07c86e 370 if (-s $bs) { # only read file if it's not empty
d404d5bf 371 print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
8e07c86e
AD
372 eval { do $bs; };
373 warn "$bs: $@\n" if $@;
374 }
375
588cafc8
DM
376 my $boot_symbol_ref;
377
1c7f9087
VK
378 <<$^O-eq-darwin>>
379 if ($boot_symbol_ref = dl_find_symbol(0, $bootname)) {
380 goto boot; #extension library has already been loaded, e.g. darwin
588cafc8 381 }
1c7f9087 382 <</$^O-eq-darwin>>
588cafc8 383
8e07c86e
AD
384 # Many dynamic extension loading problems will appear to come from
385 # this section of code: XYZ failed at line 123 of DynaLoader.pm.
386 # Often these errors are actually occurring in the initialisation
387 # C code of the extension XS file. Perl reports the error as being
388 # in this perl code simply because this was the last perl code
389 # it executed.
390
dec98916
BF
391 my $flags = $module->dl_load_flags;
392 <<$^O-eq-android>>
393 # See the note above regarding the linker.
394 $flags = 0x00;
395 <</$^O-eq-android>>
396 my $libref = dl_load_file($file, $flags) or
549a6b10 397 croak("Can't load '$file' for module $module: ".dl_error());
8e07c86e 398
ff7f3c60 399 push(@dl_librefs,$libref); # record loaded object
f24427cc 400<<$^O-eq-freemint>>
8e07c86e 401 my @unresolved = dl_undef_symbols();
fb73857a
PP
402 if (@unresolved) {
403 require Carp;
404 Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
405 }
f24427cc 406<</$^O-eq-freemint>>
588cafc8 407 $boot_symbol_ref = dl_find_symbol($libref, $bootname) or
fb73857a 408 croak("Can't find '$bootname' symbol in $file\n");
8e07c86e 409
ff7f3c60
NIS
410 push(@dl_modules, $module); # record loaded module
411
588cafc8
DM
412 boot:
413 my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
414
8e07c86e 415 # See comment block above
8cf57410
EP
416
417 push(@dl_shared_objects, $file); # record files loaded
418
8e07c86e
AD
419 &$xs(@args);
420}
421
8e07c86e 422sub dl_findfile {
8e07c86e
AD
423 # This function does not automatically consider the architecture
424 # or the perl library auto directories.
425 my (@args) = @_;
426 my (@dirs, $dir); # which directories to search
427 my (@found); # full paths to real files we have found
1c7f9087
VK
428 #my $dl_ext= <<=to_string($Config::Config{'dlext'})>>; # $Config::Config{'dlext'} suffix for perl extensions
429 #my $dl_so = <<=to_string($Config::Config{'so'})>>; # $Config::Config{'so'} suffix for shared libraries
8e07c86e
AD
430
431 print STDERR "dl_findfile(@args)\n" if $dl_debug;
432
433 # accumulate directories but process files as they appear
434 arg: foreach(@args) {
435 # Special fast case: full filepath requires no search
1c7f9087
VK
436 <<$^O-eq-VMS>>
437 if (m%[:>/\]]% && -f $_) {
54d6a3b3
PP
438 push(@found,dl_expandspec(VMS::Filespec::vmsify($_)));
439 last arg unless wantarray;
440 next;
441 }
1c7f9087 442 <</$^O-eq-VMS>>
1c7f9087
VK
443 <<$^O-ne-VMS>>
444 if (m:/: && -f $_) {
8e07c86e
AD
445 push(@found,$_);
446 last arg unless wantarray;
447 next;
448 }
1c7f9087 449 <</$^O-ne-VMS>>
8e07c86e
AD
450
451 # Deal with directories first:
452 # Using a -L prefix is the preferred option (faster and more robust)
453 if (m:^-L:) { s/^-L//; push(@dirs, $_); next; }
454
455 # Otherwise we try to try to spot directories by a heuristic
456 # (this is a more complicated issue than it first appears)
457 if (m:/: && -d $_) { push(@dirs, $_); next; }
458
1c7f9087 459 <<$^O-eq-VMS>>
7e9f3af8 460 # VMS: we may be using native VMS directory syntax instead of
8e07c86e 461 # Unix emulation, so check this as well
1c7f9087
VK
462 if (/[:>\]]/ && -d $_) { push(@dirs, $_); next; }
463 <</$^O-eq-VMS>>
8e07c86e
AD
464
465 # Only files should get this far...
466 my(@names, $name); # what filenames to look for
467 if (m:-l: ) { # convert -lname to appropriate library name
468 s/-l//;
37589e1e 469 push(@names,"lib$_.$dl_so");
8e07c86e
AD
470 push(@names,"lib$_.a");
471 } else { # Umm, a bare name. Try various alternatives:
472 # these should be ordered with the most likely first
37589e1e
JD
473 push(@names,"$_.$dl_dlext") unless m/\.$dl_dlext$/o;
474 push(@names,"$_.$dl_so") unless m/\.$dl_so$/o;
f3467506
JD
475 <<$^O-eq-cygwin>>
476 push(@names,"cyg$_.$dl_so") unless m:/:;
477 <</$^O-eq-cygwin>>
37589e1e 478 push(@names,"lib$_.$dl_so") unless m:/:;
8e07c86e
AD
479 push(@names, $_);
480 }
27da23d5
JH
481 my $dirsep = '/';
482 <<$^O-eq-symbian>>
483 $dirsep = '\\';
484 if ($0 =~ /^([a-z]):/i) {
485 my $drive = $1;
486 @dirs = map { "$drive:$_" } @dirs;
487 @dl_library_path = map { "$drive:$_" } @dl_library_path;
488 }
489 <</$^O-eq-symbian>>
8e07c86e
AD
490 foreach $dir (@dirs, @dl_library_path) {
491 next unless -d $dir;
1c7f9087
VK
492 <<$^O-eq-VMS>>
493 chop($dir = VMS::Filespec::unixpath($dir));
494 <</$^O-eq-VMS>>
8e07c86e 495 foreach $name (@names) {
27da23d5 496 my($file) = "$dir$dirsep$name";
8e07c86e 497 print STDERR " checking in $dir for $name\n" if $dl_debug;
fb73857a
PP
498 $file = ($do_expand) ? dl_expandspec($file) : (-f $file && $file);
499 #$file = _check_file($file);
8e07c86e
AD
500 if ($file) {
501 push(@found, $file);
502 next arg; # no need to look any further
503 }
504 }
505 }
506 }
507 if ($dl_debug) {
508 foreach(@dirs) {
509 print STDERR " dl_findfile ignored non-existent directory: $_\n" unless -d $_;
510 }
511 print STDERR "dl_findfile found: @found\n";
512 }
513 return $found[0] unless wantarray;
514 @found;
515}
516
517
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518<<$^O-eq-VMS>>
519# dl_expandspec should be defined in dl_vms.xs
520<<|$^O-eq-VMS>>
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521sub dl_expandspec {
522 my($spec) = @_;
523 # Optional function invoked if DynaLoader.pm sets $do_expand.
524 # Most systems do not require or use this function.
525 # Some systems may implement it in the dl_*.xs file in which case
5477b9a1 526 # this Perl version should be excluded at build time.
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527
528 # This function is designed to deal with systems which treat some
529 # 'filenames' in a special way. For example VMS 'Logical Names'
530 # (something like unix environment variables - but different).
531 # This function should recognise such names and expand them into
532 # full file paths.
533 # Must return undef if $spec is invalid or file does not exist.
534
535 my $file = $spec; # default output to input
536
8e07c86e 537 return undef unless -f $file;
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538 print STDERR "dl_expandspec($spec) => $file\n" if $dl_debug;
539 $file;
540}
5477b9a1 541<</$^O-eq-VMS>>
8e07c86e 542
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543sub dl_find_symbol_anywhere
544{
545 my $sym = shift;
546 my $libref;
547 foreach $libref (@dl_librefs) {
548 my $symref = dl_find_symbol($libref,$sym);
549 return $symref if $symref;
550 }
551 return undef;
552}
8e07c86e 553
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554__END__
555
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556=head1 NAME
557
558DynaLoader - Dynamically load C libraries into Perl code
559
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560=head1 SYNOPSIS
561
8e07c86e 562 package YourPackage;
3b35bae3 563 require DynaLoader;
c2960299 564 @ISA = qw(... DynaLoader ...);
8e07c86e 565 bootstrap YourPackage;
3b35bae3 566
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567 # optional method for 'global' loading
568 sub dl_load_flags { 0x01 }
569
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570
571=head1 DESCRIPTION
572
c2960299 573This document defines a standard generic interface to the dynamic
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574linking mechanisms available on many platforms. Its primary purpose is
575to implement automatic dynamic loading of Perl modules.
576
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577This document serves as both a specification for anyone wishing to
578implement the DynaLoader for a new platform and as a guide for
579anyone wishing to use the DynaLoader directly in an application.
580
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581The DynaLoader is designed to be a very simple high-level
582interface that is sufficiently general to cover the requirements
f05550c0 583of SunOS, HP-UX, Linux, VMS and other platforms.
3b35bae3 584
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585It is also hoped that the interface will cover the needs of OS/2, NT
586etc and also allow pseudo-dynamic linking (using C<ld -A> at runtime).
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587
588It must be stressed that the DynaLoader, by itself, is practically
589useless for accessing non-Perl libraries because it provides almost no
590Perl-to-C 'glue'. There is, for example, no mechanism for calling a C
03c9e98c 591library function or supplying arguments. A C::DynaLib module
90248788 592is available from CPAN sites which performs that function for some
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593common system types. And since the year 2000, there's also Inline::C,
594a module that allows you to write Perl subroutines in C. Also available
595from your local CPAN site.
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596
597DynaLoader Interface Summary
598
599 @dl_library_path
600 @dl_resolve_using
601 @dl_require_symbols
602 $dl_debug
4c6d3177 603 $dl_dlext
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604 @dl_librefs
605 @dl_modules
8cf57410 606 @dl_shared_objects
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607 Implemented in:
608 bootstrap($modulename) Perl
609 @filepaths = dl_findfile(@names) Perl
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610 $flags = $modulename->dl_load_flags Perl
611 $symref = dl_find_symbol_anywhere($symbol) Perl
3b35bae3 612
ff7f3c60 613 $libref = dl_load_file($filename, $flags) C
abb9e9dc 614 $status = dl_unload_file($libref) C
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615 $symref = dl_find_symbol($libref, $symbol) C
616 @symbols = dl_undef_symbols() C
617 dl_install_xsub($name, $symref [, $filename]) C
618 $message = dl_error C
619
620=over 4
621
622=item @dl_library_path
623
624The standard/default list of directories in which dl_findfile() will
625search for libraries etc. Directories are searched in order:
626$dl_library_path[0], [1], ... etc
627
628@dl_library_path is initialised to hold the list of 'normal' directories
629(F</usr/lib>, etc) determined by B<Configure> (C<$Config{'libpth'}>). This should
630ensure portability across a wide range of platforms.
631
632@dl_library_path should also be initialised with any other directories
633that can be determined from the environment at runtime (such as
634LD_LIBRARY_PATH for SunOS).
635
636After initialisation @dl_library_path can be manipulated by an
637application using push and unshift before calling dl_findfile().
638Unshift can be used to add directories to the front of the search order
639either to save search time or to override libraries with the same name
640in the 'normal' directories.
641
642The load function that dl_load_file() calls may require an absolute
643pathname. The dl_findfile() function and @dl_library_path can be
644used to search for and return the absolute pathname for the
645library/object that you wish to load.
646
647=item @dl_resolve_using
648
649A list of additional libraries or other shared objects which can be
650used to resolve any undefined symbols that might be generated by a
651later call to load_file().
652
653This is only required on some platforms which do not handle dependent
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654libraries automatically. For example the Socket Perl extension
655library (F<auto/Socket/Socket.so>) contains references to many socket
656functions which need to be resolved when it's loaded. Most platforms
657will automatically know where to find the 'dependent' library (e.g.,
658F</usr/lib/libsocket.so>). A few platforms need to be told the
659location of the dependent library explicitly. Use @dl_resolve_using
660for this.
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661
662Example usage:
663
664 @dl_resolve_using = dl_findfile('-lsocket');
665
666=item @dl_require_symbols
667
668A list of one or more symbol names that are in the library/object file
669to be dynamically loaded. This is only required on some platforms.
670
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671=item @dl_librefs
672
673An array of the handles returned by successful calls to dl_load_file(),
674made by bootstrap, in the order in which they were loaded.
675Can be used with dl_find_symbol() to look for a symbol in any of
676the loaded files.
677
678=item @dl_modules
679
680An array of module (package) names that have been bootstrap'ed.
681
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682=item @dl_shared_objects
683
684An array of file names for the shared objects that were loaded.
685
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686=item dl_error()
687
688Syntax:
689
690 $message = dl_error();
691
692Error message text from the last failed DynaLoader function. Note
693that, similar to errno in unix, a successful function call does not
694reset this message.
695
696Implementations should detect the error as soon as it occurs in any of
697the other functions and save the corresponding message for later
698retrieval. This will avoid problems on some platforms (such as SunOS)
699where the error message is very temporary (e.g., dlerror()).
700
701=item $dl_debug
702
703Internal debugging messages are enabled when $dl_debug is set true.
704Currently setting $dl_debug only affects the Perl side of the
705DynaLoader. These messages should help an application developer to
706resolve any DynaLoader usage problems.
707
708$dl_debug is set to C<$ENV{'PERL_DL_DEBUG'}> if defined.
709
710For the DynaLoader developer/porter there is a similar debugging
711variable added to the C code (see dlutils.c) and enabled if Perl was
712built with the B<-DDEBUGGING> flag. This can also be set via the
713PERL_DL_DEBUG environment variable. Set to 1 for minimal information or
714higher for more.
715
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716=item $dl_dlext
717
718When specified (localised) in a module's F<.pm> file, indicates the extension
719which the module's loadable object will have. For example:
720
721 local $DynaLoader::dl_dlext = 'unusual_ext';
722
723would indicate that the module's loadable object has an extension of
724C<unusual_ext> instead of the more usual C<$Config{dlext}>. NOTE: This also
725requires that the module's F<Makefile.PL> specify (in C<WriteMakefile()>):
726
727 DLEXT => 'unusual_ext',
728
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729=item dl_findfile()
730
731Syntax:
732
733 @filepaths = dl_findfile(@names)
734
735Determine the full paths (including file suffix) of one or more
736loadable files given their generic names and optionally one or more
737directories. Searches directories in @dl_library_path by default and
738returns an empty list if no files were found.
739
740Names can be specified in a variety of platform independent forms. Any
741names in the form B<-lname> are converted into F<libname.*>, where F<.*> is
742an appropriate suffix for the platform.
743
744If a name does not already have a suitable prefix and/or suffix then
745the corresponding file will be searched for by trying combinations of
746prefix and suffix appropriate to the platform: "$name.o", "lib$name.*"
747and "$name".
748
749If any directories are included in @names they are searched before
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750@dl_library_path. Directories may be specified as B<-Ldir>. Any other
751names are treated as filenames to be searched for.
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752
753Using arguments of the form C<-Ldir> and C<-lname> is recommended.
754
755Example:
756
757 @dl_resolve_using = dl_findfile(qw(-L/usr/5lib -lposix));
758
759
760=item dl_expandspec()
761
762Syntax:
763
764 $filepath = dl_expandspec($spec)
765
766Some unusual systems, such as VMS, require special filename handling in
767order to deal with symbolic names for files (i.e., VMS's Logical Names).
768
769To support these systems a dl_expandspec() function can be implemented
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770either in the F<dl_*.xs> file or code can be added to the dl_expandspec()
771function in F<DynaLoader.pm>. See F<DynaLoader_pm.PL> for more information.
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772
773=item dl_load_file()
774
775Syntax:
776
ff7f3c60 777 $libref = dl_load_file($filename, $flags)
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778
779Dynamically load $filename, which must be the path to a shared object
780or library. An opaque 'library reference' is returned as a handle for
781the loaded object. Returns undef on error.
782
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783The $flags argument to alters dl_load_file behaviour.
784Assigned bits:
785
786 0x01 make symbols available for linking later dl_load_file's.
787 (only known to work on Solaris 2 using dlopen(RTLD_GLOBAL))
f86702cc 788 (ignored under VMS; this is a normal part of image linking)
ff7f3c60 789
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790(On systems that provide a handle for the loaded object such as SunOS
791and HPUX, $libref will be that handle. On other systems $libref will
792typically be $filename or a pointer to a buffer containing $filename.
793The application should not examine or alter $libref in any way.)
794
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795This is the function that does the real work. It should use the
796current values of @dl_require_symbols and @dl_resolve_using if required.
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797
798 SunOS: dlopen($filename)
799 HP-UX: shl_load($filename)
800 Linux: dld_create_reference(@dl_require_symbols); dld_link($filename)
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801 VMS: lib$find_image_symbol($filename,$dl_require_symbols[0])
802
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803(The dlopen() function is also used by Solaris and some versions of
804Linux, and is a common choice when providing a "wrapper" on other
805mechanisms as is done in the OS/2 port.)
806
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807=item dl_unload_file()
808
809Syntax:
810
811 $status = dl_unload_file($libref)
812
813Dynamically unload $libref, which must be an opaque 'library reference' as
814returned from dl_load_file. Returns one on success and zero on failure.
abb9e9dc 815This function is optional and may not necessarily be provided on all platforms.
fbe4ac3d
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816
817If it is defined and perl is compiled with the C macro C<DL_UNLOAD_ALL_AT_EXIT>
818defined, then it is called automatically when the interpreter exits for
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819every shared object or library loaded by DynaLoader::bootstrap. All such
820library references are stored in @dl_librefs by DynaLoader::Bootstrap as it
22851543 821loads the libraries. The files are unloaded in last-in, first-out order.
abb9e9dc
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822
823This unloading is usually necessary when embedding a shared-object perl (e.g.
824one configured with -Duseshrplib) within a larger application, and the perl
825interpreter is created and destroyed several times within the lifetime of the
826application. In this case it is possible that the system dynamic linker will
827unload and then subsequently reload the shared libperl without relocating any
828references to it from any files DynaLoaded by the previous incarnation of the
829interpreter. As a result, any shared objects opened by DynaLoader may point to
830a now invalid 'ghost' of the libperl shared object, causing apparently random
831memory corruption and crashes. This behaviour is most commonly seen when using
832Apache and mod_perl built with the APXS mechanism.
833
834 SunOS: dlclose($libref)
835 HP-UX: ???
836 Linux: ???
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837 VMS: ???
838
839(The dlclose() function is also used by Solaris and some versions of
840Linux, and is a common choice when providing a "wrapper" on other
841mechanisms as is done in the OS/2 port.)
842
2307c6d0 843=item dl_load_flags()
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844
845Syntax:
846
2307c6d0 847 $flags = dl_load_flags $modulename;
ff7f3c60
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848
849Designed to be a method call, and to be overridden by a derived class
850(i.e. a class which has DynaLoader in its @ISA). The definition in
851DynaLoader itself returns 0, which produces standard behavior from
852dl_load_file().
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853
854=item dl_find_symbol()
855
856Syntax:
857
858 $symref = dl_find_symbol($libref, $symbol)
859
860Return the address of the symbol $symbol or C<undef> if not found. If the
861target system has separate functions to search for symbols of different
862types then dl_find_symbol() should search for function symbols first and
863then other types.
864
865The exact manner in which the address is returned in $symref is not
866currently defined. The only initial requirement is that $symref can
867be passed to, and understood by, dl_install_xsub().
868
869 SunOS: dlsym($libref, $symbol)
870 HP-UX: shl_findsym($libref, $symbol)
871 Linux: dld_get_func($symbol) and/or dld_get_symbol($symbol)
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872 VMS: lib$find_image_symbol($libref,$symbol)
873
874
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875=item dl_find_symbol_anywhere()
876
877Syntax:
878
879 $symref = dl_find_symbol_anywhere($symbol)
880
881Applies dl_find_symbol() to the members of @dl_librefs and returns
882the first match found.
883
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884=item dl_undef_symbols()
885
886Example
887
888 @symbols = dl_undef_symbols()
889
890Return a list of symbol names which remain undefined after load_file().
891Returns C<()> if not known. Don't worry if your platform does not provide
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892a mechanism for this. Most do not need it and hence do not provide it,
893they just return an empty list.
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894
895
896=item dl_install_xsub()
897
898Syntax:
899
900 dl_install_xsub($perl_name, $symref [, $filename])
901
902Create a new Perl external subroutine named $perl_name using $symref as
903a pointer to the function which implements the routine. This is simply
6114e455 904a direct call to newXS()/newXS_flags(). Returns a reference to the installed
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905function.
906
907The $filename parameter is used by Perl to identify the source file for
908the function if required by die(), caller() or the debugger. If
909$filename is not defined then "DynaLoader" will be used.
910
911
1fef88e7 912=item bootstrap()
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913
914Syntax:
915
65fa4aaa 916bootstrap($module [...])
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917
918This is the normal entry point for automatic dynamic loading in Perl.
919
920It performs the following actions:
921
922=over 8
923
924=item *
925
926locates an auto/$module directory by searching @INC
927
928=item *
929
930uses dl_findfile() to determine the filename to load
931
932=item *
933
934sets @dl_require_symbols to C<("boot_$module")>
935
936=item *
937
938executes an F<auto/$module/$module.bs> file if it exists
939(typically used to add to @dl_resolve_using any files which
940are required to load the module on the current platform)
941
942=item *
943
ff7f3c60
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944calls dl_load_flags() to determine how to load the file.
945
946=item *
947
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948calls dl_load_file() to load the file
949
950=item *
951
952calls dl_undef_symbols() and warns if any symbols are undefined
953
954=item *
955
956calls dl_find_symbol() for "boot_$module"
957
958=item *
959
960calls dl_install_xsub() to install it as "${module}::bootstrap"
961
962=item *
963
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964calls &{"${module}::bootstrap"} to bootstrap the module (actually
965it uses the function reference returned by dl_install_xsub for speed)
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966
967=back
968
65fa4aaa
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969All arguments to bootstrap() are passed to the module's bootstrap function.
970The default code generated by F<xsubpp> expects $module [, $version]
971If the optional $version argument is not given, it defaults to
972C<$XS_VERSION // $VERSION> in the module's symbol table. The default code
973compares the Perl-space version with the version of the compiled XS code,
974and croaks with an error if they do not match.
975
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976=back
977
978
979=head1 AUTHOR
980
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981Tim Bunce, 11 August 1994.
982
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983This interface is based on the work and comments of (in no particular
984order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno
c2960299 985Siegel, Thomas Neumann, Paul Marquess, Charles Bailey, myself and others.
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986
987Larry Wall designed the elegant inherited bootstrap mechanism and
988implemented the first Perl 5 dynamic loader using it.
989
ff7f3c60
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990Solaris global loading added by Nick Ing-Simmons with design/coding
991assistance from Tim Bunce, January 1996.
992
3b35bae3 993=cut
03c9e98c
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994EOT
995
996close OUT or die $!;
997