lib/perl5/5.6.1/ExtUtils/Mkbootstrap.pm

   1 package ExtUtils::Mkbootstrap;
   2
   3 $VERSION = substr q$Revision: 1.14 $, 10;
   4 # $Date: 1996/09/03 17:04:43 $
   5
   6 use Config;
   7 use Exporter;
   8 @ISA=('Exporter');
   9 @EXPORT='&Mkbootstrap';
  10
  11 sub Mkbootstrap {
  12     my($baseext, @bsloadlibs)=@_;
  13     @bsloadlibs = grep($_, @bsloadlibs); # strip empty libs
  14
  15     print STDOUT "      bsloadlibs=@bsloadlibs\n" if $Verbose;
  16
  17     # We need DynaLoader here because we and/or the *_BS file may
  18     # call dl_findfile(). We don't say `use' here because when
  19     # first building perl extensions the DynaLoader will not have
  20     # been built when MakeMaker gets first used.
  21     require DynaLoader;
  22
  23     rename "$baseext.bs", "$baseext.bso"
  24       if -s "$baseext.bs";
  25
  26     if (-f "${baseext}_BS"){
  27         $_ = "${baseext}_BS";
  28         package DynaLoader; # execute code as if in DynaLoader
  29         local($osname, $dlsrc) = (); # avoid warnings
  30         ($osname, $dlsrc) = @Config::Config{qw(osname dlsrc)};
  31         $bscode = "";
  32         unshift @INC, ".";
  33         require $_;
  34         shift @INC;
  35     }
  36
  37     if ($Config{'dlsrc'} =~ /^dl_dld/){
  38         package DynaLoader;
  39         push(@dl_resolve_using, dl_findfile('-lc'));
  40     }
  41
  42     my(@all) = (@bsloadlibs, @DynaLoader::dl_resolve_using);
  43     my($method) = '';
  44     if (@all){
  45         open BS, ">$baseext.bs"
  46                 or die "Unable to open $baseext.bs: $!";
  47         print STDOUT "Writing $baseext.bs\n";
  48         print STDOUT "  containing: @all" if $Verbose;
  49         print BS "# $baseext DynaLoader bootstrap file for $^O architecture.\n";
  50         print BS "# Do not edit this file, changes will be lost.\n";
  51         print BS "# This file was automatically generated by the\n";
  52         print BS "# Mkbootstrap routine in ExtUtils::Mkbootstrap (v$VERSION).\n";
  53         print BS "\@DynaLoader::dl_resolve_using = ";
  54         # If @all contains names in the form -lxxx or -Lxxx then it's asking for
  55         # runtime library location so we automatically add a call to dl_findfile()
  56         if (" @all" =~ m/ -[lLR]/){
  57             print BS "  dl_findfile(qw(\n  @all\n  ));\n";
  58         }else{
  59             print BS "  qw(@all);\n";
  60         }
  61         # write extra code if *_BS says so
  62         print BS $DynaLoader::bscode if $DynaLoader::bscode;
  63         print BS "\n1;\n";
  64         close BS;
  65     }
  66 }
  67
  68 1;
  69
  70 __END__
  71
  72 =head1 NAME
  73
  74 ExtUtils::Mkbootstrap - make a bootstrap file for use by DynaLoader
  75
  76 =head1 SYNOPSIS
  77
  78 C<mkbootstrap>
  79
  80 =head1 DESCRIPTION
  81
  82 Mkbootstrap typically gets called from an extension Makefile.
  83
  84 There is no C<*.bs> file supplied with the extension. Instead, there may
  85 be a C<*_BS> file which has code for the special cases, like posix for
  86 berkeley db on the NeXT.
  87
  88 This file will get parsed, and produce a maybe empty
  89 C<@DynaLoader::dl_resolve_using> array for the current architecture.
  90 That will be extended by $BSLOADLIBS, which was computed by
  91 ExtUtils::Liblist::ext(). If this array still is empty, we do nothing,
  92 else we write a .bs file with an C<@DynaLoader::dl_resolve_using>
  93 array.
  94
  95 The C<*_BS> file can put some code into the generated C<*.bs> file by
  96 placing it in C<$bscode>. This is a handy 'escape' mechanism that may
  97 prove useful in complex situations.
  98
  99 If @DynaLoader::dl_resolve_using contains C<-L*> or C<-l*> entries then
 100 Mkbootstrap will automatically add a dl_findfile() call to the
 101 generated C<*.bs> file.
 102
 103 =cut