1package ExtUtils::Mkbootstrap;
2
3$VERSION = 1.15;
4
5use Config;
6use Exporter;
7@ISA=('Exporter');
8@EXPORT='&Mkbootstrap';
9
10sub Mkbootstrap {
11    my($baseext, @bsloadlibs)=@_;
12    @bsloadlibs = grep($_, @bsloadlibs); # strip empty libs
13
14    print STDOUT "	bsloadlibs=@bsloadlibs\n" if $Verbose;
15
16    # We need DynaLoader here because we and/or the *_BS file may
17    # call dl_findfile(). We don't say `use' here because when
18    # first building perl extensions the DynaLoader will not have
19    # been built when MakeMaker gets first used.
20    require DynaLoader;
21
22    rename "$baseext.bs", "$baseext.bso"
23      if -s "$baseext.bs";
24
25    if (-f "${baseext}_BS"){
26	$_ = "${baseext}_BS";
27	package DynaLoader; # execute code as if in DynaLoader
28	local($osname, $dlsrc) = (); # avoid warnings
29	($osname, $dlsrc) = @Config::Config{qw(osname dlsrc)};
30	$bscode = "";
31	unshift @INC, ".";
32	require $_;
33	shift @INC;
34    }
35
36    if ($Config{'dlsrc'} =~ /^dl_dld/){
37	package DynaLoader;
38	push(@dl_resolve_using, dl_findfile('-lc'));
39    }
40
41    my(@all) = (@bsloadlibs, @DynaLoader::dl_resolve_using);
42    my($method) = '';
43    if (@all){
44	open BS, ">$baseext.bs"
45		or die "Unable to open $baseext.bs: $!";
46	print STDOUT "Writing $baseext.bs\n";
47	print STDOUT "	containing: @all" if $Verbose;
48	print BS "# $baseext DynaLoader bootstrap file for $^O architecture.\n";
49	print BS "# Do not edit this file, changes will be lost.\n";
50	print BS "# This file was automatically generated by the\n";
51	print BS "# Mkbootstrap routine in ExtUtils::Mkbootstrap (v$VERSION).\n";
52	print BS "\@DynaLoader::dl_resolve_using = ";
53	# If @all contains names in the form -lxxx or -Lxxx then it's asking for
54	# runtime library location so we automatically add a call to dl_findfile()
55	if (" @all" =~ m/ -[lLR]/){
56	    print BS "  dl_findfile(qw(\n  @all\n  ));\n";
57	}else{
58	    print BS "  qw(@all);\n";
59	}
60	# write extra code if *_BS says so
61	print BS $DynaLoader::bscode if $DynaLoader::bscode;
62	print BS "\n1;\n";
63	close BS;
64    }
65}
66
671;
68
69__END__
70
71=head1 NAME
72
73ExtUtils::Mkbootstrap - make a bootstrap file for use by DynaLoader
74
75=head1 SYNOPSIS
76
77C<Mkbootstrap>
78
79=head1 DESCRIPTION
80
81Mkbootstrap typically gets called from an extension Makefile.
82
83There is no C<*.bs> file supplied with the extension. Instead, there may
84be a C<*_BS> file which has code for the special cases, like posix for
85berkeley db on the NeXT.
86
87This file will get parsed, and produce a maybe empty
88C<@DynaLoader::dl_resolve_using> array for the current architecture.
89That will be extended by $BSLOADLIBS, which was computed by
90ExtUtils::Liblist::ext(). If this array still is empty, we do nothing,
91else we write a .bs file with an C<@DynaLoader::dl_resolve_using>
92array.
93
94The C<*_BS> file can put some code into the generated C<*.bs> file by
95placing it in C<$bscode>. This is a handy 'escape' mechanism that may
96prove useful in complex situations.
97
98If @DynaLoader::dl_resolve_using contains C<-L*> or C<-l*> entries then
99Mkbootstrap will automatically add a dl_findfile() call to the
100generated C<*.bs> file.
101
102=cut
103