add missing file

p4raw-id: //depot/perl@4624

Author: Gurusamy Sarathy

ext/DynaLoader/XSLoader_pm.PL

@@ -0,0 +1,158 @@
+use Config;
+
+sub to_string {
+    my ($value) = @_;
+    $value =~ s/\\/\\\\/g;
+    $value =~ s/'/\\'/g;
+    return "'$value'";
+}
+
+unlink "XSLoader.pm" if -f "XSLoader.pm";
+open OUT, ">XSLoader.pm" or die $!;
+print OUT <<'EOT';
+# Generated from XSLoader.pm.PL (resolved %Config::Config value)
+
+package XSLoader;
+
+#   And Gandalf said: 'Many folk like to know beforehand what is to
+#   be set on the table; but those who have laboured to prepare the
+#   feast like to keep their secret; for wonder makes the words of
+#   praise louder.'
+
+#   (Quote from Tolkien sugested by Anno Siegel.)
+#
+# See pod text at end of file for documentation.
+# See also ext/DynaLoader/README in source tree for other information.
+#
+# [email protected], August 1994
+
+$VERSION = "0.01";	# avoid typo warning
+
+# enable debug/trace messages from DynaLoader perl code
+# $dl_debug = $ENV{PERL_DL_DEBUG} || 0 unless defined $dl_debug;
+
+EOT
+
+print OUT '  my $dl_dlext = ', to_string($Config::Config{'dlext'}), ";\n" ;
+
+print OUT <<'EOT';
+
+# No prizes for guessing why we don't say 'bootstrap DynaLoader;' here.
+package DynaLoader;
+boot_DynaLoader('DynaLoader') if defined(&boot_DynaLoader) &&
+                                !defined(&dl_load_file);
+package XSLoader;
+
+1; # End of main code
+
+# The bootstrap function cannot be autoloaded (without complications)
+# so we define it here:
+
+sub load {
+    package DynaLoader;
+
+    my($module) = $_[0];
+
+    # work with static linking too
+    my $b = "$module\::bootstrap";
+    goto &$b if defined &$b;
+
+    goto retry unless $module and defined &dl_load_file;
+
+    my @modparts = split(/::/,$module);
+    my $modfname = $modparts[-1];
+
+EOT
+
+print OUT <<'EOT' if defined &DynaLoader::mod2fname;
+    # Some systems have restrictions on files names for DLL's etc.
+    # mod2fname returns appropriate file base name (typically truncated)
+    # It may also edit @modparts if required.
+    $modfname = &mod2fname(\@modparts) if defined &mod2fname;
+
+EOT
+
+print OUT <<'EOT';
+    my $modpname = join('/',@modparts);
+    my $modlibname = (caller())[1];
+    my $c = @modparts;
+    $modlibname =~ s,[\\/][^\\/]+$,, while $c--;	# Q&D basename
+    my $file = "$modlibname/auto/$modpname/$modfname.$dl_dlext";
+
+#   print STDERR "XSLoader::load for $module ($file)\n" if $dl_debug;
+
+    my $bs = $file;
+    $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
+
+    goto retry if not -f $file or -s $bs;
+
+    my $bootname = "boot_$module";
+    $bootname =~ s/\W/_/g;
+    @dl_require_symbols = ($bootname);
+
+    # Many dynamic extension loading problems will appear to come from
+    # this section of code: XYZ failed at line 123 of DynaLoader.pm.
+    # Often these errors are actually occurring in the initialisation
+    # C code of the extension XS file. Perl reports the error as being
+    # in this perl code simply because this was the last perl code
+    # it executed.
+
+    my $libref = dl_load_file($file, 0) or do { 
+	require Carp;
+	Carp::croak("Can't load '$file' for module $module: " . dl_error());
+    };
+    push(@dl_librefs,$libref);  # record loaded object
+
+    my @unresolved = dl_undef_symbols();
+    if (@unresolved) {
+	require Carp;
+	Carp::carp("Undefined symbols present after loading $file: @unresolved\n");
+    }
+
+    my $boot_symbol_ref = dl_find_symbol($libref, $bootname) or do {
+	require Carp;
+	Carp::croak("Can't find '$bootname' symbol in $file\n");
+    };
+
+    my $xs = dl_install_xsub("${module}::bootstrap", $boot_symbol_ref, $file);
+
+    push(@dl_modules, $module); # record loaded module
+
+    # See comment block above
+    return &$xs(@_);
+
+  retry:
+    require DynaLoader;
+    goto &DynaLoader::bootstrap_inherit;
+}
+
+__END__
+
+=head1 NAME
+
+XSLoader - Dynamically load C libraries into Perl code
+
+=head1 SYNOPSIS
+
+    package YourPackage;
+    use XSLoader;
+
+    XSLoader::load 'YourPackage', @args;
+
+=head1 DESCRIPTION
+
+This module defines a standard I<simplified> interface to the dynamic
+linking mechanisms available on many platforms.  Its primary purpose is
+to implement cheap automatic dynamic loading of Perl modules.
+
+For more complicated interface see L<DynaLoader>.
+
+=head1 AUTHOR
+
+Ilya Zakharevich: extraction from DynaLoader.
+
+=cut
+EOT
+
+close OUT or die $!;
+