package AutoLoader;
use strict;
use 5.006_001;
our($VERSION, $AUTOLOAD);
my $is_dosish;
my $is_epoc;
my $is_vms;
my $is_macos;
BEGIN {
$is_dosish = $^O eq 'dos' || $^O eq 'os2' || $^O eq 'MSWin32' || $^O eq 'NetWare';
$is_epoc = $^O eq 'epoc';
$is_vms = $^O eq 'VMS';
$is_macos = $^O eq 'MacOS';
$VERSION = '5.68';
}
AUTOLOAD {
my $sub = $AUTOLOAD;
my $filename = AutoLoader::find_filename( $sub );
my $save = $@;
local $!; # Do not munge the value.
eval { local $SIG{__DIE__}; require $filename };
if ($@) {
if (substr($sub,-9) eq '::DESTROY') {
no strict 'refs';
*$sub = sub {};
$@ = undef;
} elsif ($@ =~ /^Can't locate/) {
# The load might just have failed because the filename was too
# long for some old SVR3 systems which treat long names as errors.
# If we can successfully truncate a long name then it's worth a go.
# There is a slight risk that we could pick up the wrong file here
# but autosplit should have warned about that when splitting.
if ($filename =~ s/(\w{12,})\.al$/substr($1,0,11).".al"/e){
eval { local $SIG{__DIE__}; require $filename };
}
}
if ($@){
$@ =~ s/ at .*\n//;
my $error = $@;
require Carp;
Carp::croak($error);
}
}
$@ = $save;
goto &$sub;
}
sub find_filename {
my $sub = shift;
my $filename;
# Braces used to preserve $1 et al.
{
# Try to find the autoloaded file from the package-qualified
# name of the sub. e.g., if the sub needed is
# Getopt::Long::GetOptions(), then $INC{Getopt/Long.pm} is
# something like '/usr/lib/perl5/Getopt/Long.pm', and the
# autoload file is '/usr/lib/perl5/auto/Getopt/Long/GetOptions.al'.
#
# However, if @INC is a relative path, this might not work. If,
# for example, @INC = ('lib'), then $INC{Getopt/Long.pm} is
# 'lib/Getopt/Long.pm', and we want to require
# 'auto/Getopt/Long/GetOptions.al' (without the leading 'lib').
# In this case, we simple prepend the 'auto/' and let the
# C take care of the searching for us.
my ($pkg,$func) = ($sub =~ /(.*)::([^:]+)$/);
$pkg =~ s#::#/#g;
if (defined($filename = $INC{"$pkg.pm"})) {
if ($is_macos) {
$pkg =~ tr#/#:#;
$filename = undef
unless $filename =~ s#^(.*)$pkg\.pm\z#$1auto:$pkg:$func.al#s;
} else {
$filename = undef
unless $filename =~ s#^(.*)$pkg\.pm\z#$1auto/$pkg/$func.al#s;
}
# if the file exists, then make sure that it is a
# a fully anchored path (i.e either '/usr/lib/auto/foo/bar.al',
# or './lib/auto/foo/bar.al'. This avoids C searching
# (and failing) to find the 'lib/auto/foo/bar.al' because it
# looked for 'lib/lib/auto/foo/bar.al', given @INC = ('lib').
if (defined $filename and -r $filename) {
unless ($filename =~ m|^/|s) {
if ($is_dosish) {
unless ($filename =~ m{^([a-z]:)?[\\/]}is) {
if ($^O ne 'NetWare') {
$filename = "./$filename";
} else {
$filename = "$filename";
}
}
}
elsif ($is_epoc) {
unless ($filename =~ m{^([a-z?]:)?[\\/]}is) {
$filename = "./$filename";
}
}
elsif ($is_vms) {
# XXX todo by VMSmiths
$filename = "./$filename";
}
elsif (!$is_macos) {
$filename = "./$filename";
}
}
}
else {
$filename = undef;
}
}
unless (defined $filename) {
# let C do the searching
$filename = "auto/$sub.al";
$filename =~ s#::#/#g;
}
}
return $filename;
}
sub import {
my $pkg = shift;
my $callpkg = caller;
#
# Export symbols, but not by accident of inheritance.
#
if ($pkg eq 'AutoLoader') {
if ( @_ and $_[0] =~ /^&?AUTOLOAD$/ ) {
no strict 'refs';
*{ $callpkg . '::AUTOLOAD' } = \&AUTOLOAD;
}
}
#
# Try to find the autosplit index file. Eg., if the call package
# is POSIX, then $INC{POSIX.pm} is something like
# '/usr/local/lib/perl5/POSIX.pm', and the autosplit index file is in
# '/usr/local/lib/perl5/auto/POSIX/autosplit.ix', so we require that.
#
# However, if @INC is a relative path, this might not work. If,
# for example, @INC = ('lib'), then
# $INC{POSIX.pm} is 'lib/POSIX.pm', and we want to require
# 'auto/POSIX/autosplit.ix' (without the leading 'lib').
#
(my $calldir = $callpkg) =~ s#::#/#g;
my $path = $INC{$calldir . '.pm'};
if (defined($path)) {
# Try absolute path name, but only eval it if the
# transformation from module path to autosplit.ix path
# succeeded!
my $replaced_okay;
if ($is_macos) {
(my $malldir = $calldir) =~ tr#/#:#;
$replaced_okay = ($path =~ s#^(.*)$malldir\.pm\z#$1auto:$malldir:autosplit.ix#s);
} else {
$replaced_okay = ($path =~ s#^(.*)$calldir\.pm\z#$1auto/$calldir/autosplit.ix#);
}
eval { require $path; } if $replaced_okay;
# If that failed, try relative path with normal @INC searching.
if (!$replaced_okay or $@) {
$path ="auto/$calldir/autosplit.ix";
eval { require $path; };
}
if ($@) {
my $error = $@;
require Carp;
Carp::carp($error);
}
}
}
sub unimport {
my $callpkg = caller;
no strict 'refs';
for my $exported (qw( AUTOLOAD )) {
my $symname = $callpkg . '::' . $exported;
undef *{ $symname } if \&{ $symname } == \&{ $exported };
*{ $symname } = \&{ $symname };
}
}
1;
__END__
=head1 NAME
AutoLoader - load subroutines only on demand
=head1 SYNOPSIS
package Foo;
use AutoLoader 'AUTOLOAD'; # import the default AUTOLOAD subroutine
package Bar;
use AutoLoader; # don't import AUTOLOAD, define our own
sub AUTOLOAD {
...
$AutoLoader::AUTOLOAD = "...";
goto &AutoLoader::AUTOLOAD;
}
=head1 DESCRIPTION
The B module works with the B module and the
C<__END__> token to defer the loading of some subroutines until they are
used rather than loading them all at once.
To use B, the author of a module has to place the
definitions of subroutines to be autoloaded after an C<__END__> token.
(See L.) The B module can then be run manually to
extract the definitions into individual files F.
B implements an AUTOLOAD subroutine. When an undefined
subroutine in is called in a client module of B,
B's AUTOLOAD subroutine attempts to locate the subroutine in a
file with a name related to the location of the file from which the
client module was read. As an example, if F is located in
F, B will look for perl
subroutines B in F, where
the C<.al> file has the same name as the subroutine, sans package. If
such a file exists, AUTOLOAD will read and evaluate it,
thus (presumably) defining the needed subroutine. AUTOLOAD will then
C the newly defined subroutine.
Once this process completes for a given function, it is defined, so
future calls to the subroutine will bypass the AUTOLOAD mechanism.
=head2 Subroutine Stubs
In order for object method lookup and/or prototype checking to operate
correctly even when methods have not yet been defined it is necessary to
"forward declare" each subroutine (as in C). See
L. Such forward declaration creates "subroutine
stubs", which are place holders with no code.
The AutoSplit and B modules automate the creation of forward
declarations. The AutoSplit module creates an 'index' file containing
forward declarations of all the AutoSplit subroutines. When the
AutoLoader module is 'use'd it loads these declarations into its callers
package.
Because of this mechanism it is important that B is always
C