al.patch

--- AutoLoader.pm.orig	Wed Aug 13 01:11:29 1997
+++ AutoLoader.pm	Fri Aug 22 00:21:52 1997
@@ -1,7 +1,7 @@
 package AutoLoader;
 
 use Carp;
-use vars qw(@EXPORT @EXPORT_OK);
+use vars qw(@EXPORT @EXPORT_OK $Verbose $Notruncate);
 
 BEGIN {
     require Exporter;
@@ -9,6 +9,9 @@
     @EXPORT_OK = qw(AUTOLOAD);
 }
 
+$Verbose    = 0 unless $Verbose;
+$Notruncate = 0 unless $Notruncate;
+
 AUTOLOAD {
     my $name;
     # Braces used to preserve $1 et al.
@@ -31,15 +34,18 @@
     if ($@) {
 	if (substr($AUTOLOAD,-9) eq '::DESTROY') {
 	    *$AUTOLOAD = sub {};
-	} else {
+	}
+	else {
 	    # 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 succesfully 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 ($name =~ s/(\w{12,})\.al$/substr($1,0,11).".al"/e){
-		eval {local $SIG{__DIE__};require $name};
-	    }
+	    if (!$Notruncate &&
+		$name =~ s/(\w{12,})\.al$/substr($1,0,11).".al"/e)
+	        {
+		    eval {local $SIG{__DIE__};require $name};
+		}
 	    if ($@){
 		$@ =~ s/ at .*\n//;
 		croak $@;
@@ -47,6 +53,7 @@
 	}
     }
     $@ = $save;
+    carp "AutoLoaded $AUTOLOAD" if $Verbose;
     goto &$AUTOLOAD;
 }
 
@@ -134,6 +141,18 @@
 Once this process completes for a given funtion, it is defined, so
 future calls to the subroutine will bypass the AUTOLOAD mechanism.
 
+You can say C<BEGIN { $AutoLoader::Verbose=1 }> to see which routines are
+being autoloaded from which points in your code.
+
+Normally if B<AutoLoader> fails to successfully read and evaluate the
+C<.al> file corresponding to a subroutine, another attempt will be made
+with the filename shortened to 14 characters.  If this attempt fails, an
+exception is raised.  While this allows B<AutoLoader> to function on
+machines without long filename support, it causes some difficulties because
+the filename returned in the exception is the truncated one.  To avoid
+this, the truncation behavior can be turned off by saying C<BEGIN {
+$AutoLoader::Notruncate=1 }>.
+
 =head2 Subroutine Stubs
 
 In order for object method lookup and/or prototype checking to operate
@@ -142,10 +161,10 @@
 L<perlsub/"SYNOPSIS">.  Such forward declaration creates "subroutine
 stubs", which are place holders with no code.
 
-The AutoSplit and B<AutoLoader> 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
+The B<AutoSplit> and B<AutoLoader> modules automate the creation of forward
+declarations.  The B<AutoSplit> module creates an 'index' file containing
+forward declarations of all the B<AutoSplit> subroutines.  When the
+AutoLoaded module is 'use'd it loads these declarations into its callers
 package.
 
 Because of this mechanism it is important that B<AutoLoader> is always
@@ -188,7 +207,7 @@
     }
 
 If any module's own AUTOLOAD subroutine has no need to fallback to the
-AutoLoader's AUTOLOAD subroutine (because it doesn't have any AutoSplit
+AutoLoader's AUTOLOAD subroutine (because it doesn't have any B<AutoSplit>
 subroutines), then that module should not use B<AutoLoader> at all.
 
 =head2 Package Lexicals
@@ -205,6 +224,18 @@
 visible to any autoloaded routines (but will not be invisible outside
 the package, unfortunately).
 
+=head2 B<AutoLoader> and C<use>d modules
+
+Because B<AutoLoader> simply C<require>s the appropriate C<.al> file to
+complete a call to an autoloaded subroutine, it can also be used to delay
+the loading of the modules that are called by said subroutine.  If modules
+are C<use>d before the C<__END__> tag, they will be loaded when the package
+is C<use>d, but if the modules are C<use>d directly before the definition
+of a subroutines that calls them, their loading will be delayed until that
+subroutine is called.  (This works because B<AutoSplit> will place the
+C<use> of the module in the C<.al> file for the subroutine.  Thus the
+C<use> will not happen until the subroutine is autoloaded.)
+
 =head2 B<AutoLoader> vs. B<SelfLoader>
 
 The B<AutoLoader> is similar in purpose to B<SelfLoader>: both delay the
@@ -233,8 +264,15 @@
 
 On systems with restrictions on file name length, the file corresponding
 to a subroutine may have a shorter name that the routine itself.  This
-can lead to conflicting file names.  The I<AutoSplit> package warns of
+can lead to conflicting file names.  The B<AutoSplit> package warns of
 these potential conflicts when used to split a module.
+
+The setting of C<AutoLoader::Notruncate> is not intended as an alternative
+to removing the C<__END__> tag and the inclusion of the AutoLoader module.
+The former only gives you the correct name of the failed file in the case
+of a parsing error, while the latter is the only way to completely check
+for syntax errors since autoloading also delays syntax checking until
+runtime.
 
 =head1 SEE ALSO