AutoSplit - split a package for autoloading

 autosplit($file, $dir, $keep, $check, $modtime);

 autosplit_lib_modules(@modules);

 perl -e 'use AutoSplit; autosplit($ARGV[0], $ARGV[1], 0, 1, 1)'

   package NAME;
   __END__
   sub AAA { ... }
   package NAME::option1;
   sub BBB { ... }
   package NAME::option2;
   sub BBB { ... }

   package NAME;
   __END__
   sub AAA { ... }
   sub NAME::option1::BBB { ... }
   sub NAME::option2::BBB { ... }

             Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
        2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
        by Larry Wall and others

			    All rights reserved.

    This program is free software; you can redistribute it and/or modify
    it under the terms of either:

	a) the GNU General Public License as published by the Free
	Software Foundation; either version 1, or (at your option) any
	later version, or

	b) the "Artistic License" which comes with this Kit.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See either
    the GNU General Public License or the Artistic License for more details.

    You should have received a copy of the Artistic License with this
    Kit, in the file named "Artistic".  If not, I'll be glad to provide one.

    You should also have received a copy of the GNU General Public License
    along with this program in the file named "Copying". If not, write to the 
    Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 
    02111-1307, USA or visit their web page on the internet at
    http://www.gnu.org/copyleft/gpl.html.

    For those of you that choose to use the GNU General Public License,
    my interpretation of the GNU General Public License is that no Perl
    script falls under the terms of the GPL unless you explicitly put
    said script under the terms of the GPL yourself.  Furthermore, any
    object code linked with perl does not automatically fall under the
    terms of the GPL, provided such object code only adds definitions
    of subroutines and variables, and does not otherwise impair the
    resulting interpreter from executing any standard Perl script.  I
    consider linking in C subroutines in this manner to be the moral
    equivalent of defining subroutines in the Perl language itself.  You
    may sell such an object file as proprietary provided that you provide
    or offer to provide the Perl source, as specified by the GNU General
    Public License.  (This is merely an alternate way of specifying input
    to the program.)  You may also sell a binary produced by the dumping of
    a running Perl script that belongs to you, provided that you provide or
    offer to provide the Perl source as specified by the GPL.  (The
    fact that a Perl interpreter and your code are in the same binary file
    is, in this case, a form of mere aggregation.)  This is my interpretation
    of the GPL.  If you still have concerns or difficulties understanding
    my intent, feel free to contact me.  Of course, the Artistic License
    spells all this out for your protection, so you may prefer to use that.

package AutoSplit;

use Exporter ();
use Config qw(%Config);
use File::Basename ();
use File::Path qw(mkpath);
use File::Spec::Functions qw(curdir catfile catdir);
use strict;
our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Verbose, $Keep, $Maxlen,
    $CheckForAutoloader, $CheckModTime);

$VERSION = "1.06";
@ISA = qw(Exporter);
@EXPORT = qw(&autosplit &autosplit_lib_modules);
@EXPORT_OK = qw($Verbose $Keep $Maxlen $CheckForAutoloader $CheckModTime);

# for portability warn about names longer than $maxlen
$Maxlen  = 8;	# 8 for dos, 11 (14-".al") for SYSVR3
$Verbose = 1;	# 0=none, 1=minimal, 2=list .al files
$Keep    = 0;
$CheckForAutoloader = 1;
$CheckModTime = 1;

my $IndexFile = "autosplit.ix";	# file also serves as timestamp
my $maxflen = 255;
$maxflen = 14 if $Config{'d_flexfnam'} ne 'define';
if (defined (&Dos::UseLFN)) {
     $maxflen = Dos::UseLFN() ? 255 : 11;
}
my $Is_VMS = ($^O eq 'VMS');

# allow checking for valid ': attrlist' attachments.
# extra jugglery required to support both 5.8 and 5.9/5.10 features
# (support for 5.8 required for cross-compiling environments)

my $attr_list = 
  $] >= 5.009005 ?
  eval <<'__QR__'
  qr{
    \s* : \s*
    (?:
	# one attribute
	(?> # no backtrack
	    (?! \d) \w+
	    (?<nested> \( (?: [^()]++ | (?&nested)++ )*+ \) ) ?
	)
	(?: \s* : \s* | \s+ (?! :) )
    )*
  }x
__QR__
  :
  do {
    # In pre-5.9.5 world we have to do dirty tricks.
    # (we use 'our' rather than 'my' here, due to the rather complex and buggy
    # behaviour of lexicals with qr// and (??{$lex}) )
    our $trick1; # yes, cannot our and assign at the same time.
    $trick1 = qr{ \( (?: (?> [^()]+ ) | (??{ $trick1 }) )* \) }x;
    our $trick2 = qr{ (?> (?! \d) \w+ (?:$trick1)? ) (?:\s*\:\s*|\s+(?!\:)) }x;
    qr{ \s* : \s* (?: $trick2 )* }x;
  };

sub autosplit{
    my($file, $autodir,  $keep, $ckal, $ckmt) = @_;
    # $file    - the perl source file to be split (after __END__)
    # $autodir - the ".../auto" dir below which to write split subs
    # Handle optional flags:
    $keep = $Keep unless defined $keep;
    $ckal = $CheckForAutoloader unless defined $ckal;
    $ckmt = $CheckModTime unless defined $ckmt;
    autosplit_file($file, $autodir, $keep, $ckal, $ckmt);
}

sub carp{
    require Carp;
    goto &Carp::carp;
}

# This function is used during perl building/installation
# ./miniperl -e 'use AutoSplit; autosplit_lib_modules(@ARGV)' ...

sub autosplit_lib_modules {
    my(@modules) = @_; # list of Module names
    local $_; # Avoid clobber.
    while (defined($_ = shift @modules)) {
	while (m#([^:]+)::([^:].*)#) { # in case specified as ABC::XYZ
	    $_ = catfile($1, $2);
	}
	s|\\|/|g;		# bug in ksh OS/2
	s#^lib/##s; # incase specified as lib/*.pm
	my($lib) = catfile(curdir(), "lib");
	if ($Is_VMS) { # may need to convert VMS-style filespecs
	    $lib =~ s#^\[\]#.\/#;
	}
	s#^$lib\W+##s; # incase specified as ./lib/*.pm
	if ($Is_VMS && /[:>\]]/) { # may need to convert VMS-style filespecs
	    my ($dir,$name) = (/(.*])(.*)/s);
	    $dir =~ s/.*lib[\.\]]//s;
	    $dir =~ s#[\.\]]#/#g;
	    $_ = $dir . $name;
	}
	autosplit_file(catfile($lib, $_), catfile($lib, "auto"),
		       $Keep, $CheckForAutoloader, $CheckModTime);
    }
    0;
}


# private functions

my $self_mod_time = (stat __FILE__)[9];

sub autosplit_file {
    my($filename, $autodir, $keep, $check_for_autoloader, $check_mod_time)
	= @_;
    my(@outfiles);
    local($_);
    local($/) = "\n";

    # where to write output files
    $autodir ||= catfile(curdir(), "lib", "auto");
    if ($Is_VMS) {
	($autodir = VMS::Filespec::unixpath($autodir)) =~ s|/\z||;
	$filename = VMS::Filespec::unixify($filename); # may have dirs
    }
    unless (-d $autodir){
	mkpath($autodir,0,0755);
	# We should never need to create the auto dir
	# here. installperl (or similar) should have done
	# it. Expecting it to exist is a valuable sanity check against
	# autosplitting into some random directory by mistake.
	print "Warning: AutoSplit had to create top-level " .
	    "$autodir unexpectedly.\n";
    }

    # allow just a package name to be used
    $filename .= ".pm" unless ($filename =~ m/\.pm\z/);

    open(my $in, "<$filename") or die "AutoSplit: Can't open $filename: $!\n";
    my($pm_mod_time) = (stat($filename))[9];
    my($autoloader_seen) = 0;
    my($in_pod) = 0;
    my($def_package,$last_package,$this_package,$fnr);
    while (<$in>) {
	# Skip pod text.
	$fnr++;
	$in_pod = 1 if /^=\w/;
	$in_pod = 0 if /^=cut/;
	next if ($in_pod || /^=cut/);
        next if /^\s*#/;

	# record last package name seen
	$def_package = $1 if (m/^\s*package\s+([\w:]+)\s*;/);
	++$autoloader_seen if m/^\s*(use|require)\s+AutoLoader\b/;
	++$autoloader_seen if m/\bISA\s*=.*\bAutoLoader\b/;
	last if /^__END__/;
    }
    if ($check_for_autoloader && !$autoloader_seen){
	print "AutoSplit skipped $filename: no AutoLoader used\n"
	    if ($Verbose>=2);
	return 0;
    }
    $_ or die "Can't find __END__ in $filename\n";

    $def_package or die "Can't find 'package Name;' in $filename\n";

    my($modpname) = _modpname($def_package); 

    # this _has_ to match so we have a reasonable timestamp file
    die "Package $def_package ($modpname.pm) does not ".
	"match filename $filename"
	    unless ($filename =~ m/\Q$modpname.pm\E$/ or
		    ($^O eq 'dos') or ($^O eq 'MSWin32') or ($^O eq 'NetWare') or
	            $Is_VMS && $filename =~ m/$modpname.pm/i);

    my($al_idx_file) = catfile($autodir, $modpname, $IndexFile);

    if ($check_mod_time){
	my($al_ts_time) = (stat("$al_idx_file"))[9] || 1;
	if ($al_ts_time >= $pm_mod_time and
	    $al_ts_time >= $self_mod_time){
	    print "AutoSplit skipped ($al_idx_file newer than $filename)\n"
		if ($Verbose >= 2);
	    return undef;	# one undef, not a list
	}
    }

    my($modnamedir) = catdir($autodir, $modpname);
    print "AutoSplitting $filename ($modnamedir)\n"
	if $Verbose;

    unless (-d $modnamedir){
	mkpath($modnamedir,0,0777);
    }

    # We must try to deal with some SVR3 systems with a limit of 14
    # characters for file names. Sadly we *cannot* simply truncate all
    # file names to 14 characters on these systems because we *must*
    # create filenames which exactly match the names used by AutoLoader.pm.
    # This is a problem because some systems silently truncate the file
    # names while others treat long file names as an error.

    my $Is83 = $maxflen==11;  # plain, case INSENSITIVE dos filenames

    my(@subnames, $subname, %proto, %package);
    my @cache = ();
    my $caching = 1;
    $last_package = '';
    my $out;
    while (<$in>) {
	$fnr++;
	$in_pod = 1 if /^=\w/;
	$in_pod = 0 if /^=cut/;
	next if ($in_pod || /^=cut/);
	# the following (tempting) old coding gives big troubles if a
	# cut is forgotten at EOF:
	# next if /^=\w/ .. /^=cut/;
	if (/^package\s+([\w:]+)\s*;/) {
	    $this_package = $def_package = $1;
	}

	if (/^sub\s+([\w:]+)(\s*(?:\(.*?\))?(?:$attr_list)?)/) {
	    print $out "# end of $last_package\::$subname\n1;\n"
		if $last_package;
	    $subname = $1;
	    my $proto = $2 || '';
	    if ($subname =~ s/(.*):://){
		$this_package = $1;
	    } else {
		$this_package = $def_package;
	    }
	    my $fq_subname = "$this_package\::$subname";
	    $package{$fq_subname} = $this_package;
	    $proto{$fq_subname} = $proto;
	    push(@subnames, $fq_subname);
	    my($lname, $sname) = ($subname, substr($subname,0,$maxflen-3));
	    $modpname = _modpname($this_package);
            my($modnamedir) = catdir($autodir, $modpname);
	    mkpath($modnamedir,0,0777);
	    my($lpath) = catfile($modnamedir, "$lname.al");
	    my($spath) = catfile($modnamedir, "$sname.al");
	    my $path;

	    if (!$Is83 and open($out, ">$lpath")){
	        $path=$lpath;
		print "  writing $lpath\n" if ($Verbose>=2);
	    } else {
		open($out, ">$spath") or die "Can't create $spath: $!\n";
		$path=$spath;
		print "  writing $spath (with truncated name)\n"
			if ($Verbose>=1);
	    }
	    push(@outfiles, $path);
	    my $lineno = $fnr - @cache;
	    print $out <<EOT;
# NOTE: Derived from $filename.
# Changes made here will be lost when autosplit is run again.
# See AutoSplit.pm.
package $this_package;

#line $lineno "$filename (autosplit into $path)"
EOT
	    print $out @cache;
	    @cache = ();
	    $caching = 0;
	}
	if($caching) {
	    push(@cache, $_) if @cache || /\S/;
	} else {
	    print $out $_;
	}
	if(/^\}/) {
	    if($caching) {
		print $out @cache;
		@cache = ();
	    }
	    print $out "\n";
	    $caching = 1;
	}
	$last_package = $this_package if defined $this_package;
    }
    if ($subname) {
	print $out @cache,"1;\n# end of $last_package\::$subname\n";
	close($out);
    }
    close($in);
    
    if (!$keep){  # don't keep any obsolete *.al files in the directory
	my(%outfiles);
	# @outfiles{@outfiles} = @outfiles;
	# perl downcases all filenames on VMS (which upcases all filenames) so
	# we'd better downcase the sub name list too, or subs with upper case
	# letters in them will get their .al files deleted right after they're
	# created. (The mixed case sub name won't match the all-lowercase
	# filename, and so be cleaned up as a scrap file)
	if ($Is_VMS or $Is83) {
	    %outfiles = map {lc($_) => lc($_) } @outfiles;
	} else {
	    @outfiles{@outfiles} = @outfiles;
	}  
	my(%outdirs,@outdirs);
	for (@outfiles) {
	    $outdirs{File::Basename::dirname($_)}||=1;
	}
	for my $dir (keys %outdirs) {
	    opendir(my $outdir,$dir);
	    foreach (sort readdir($outdir)){
		next unless /\.al\z/;
		my($file) = catfile($dir, $_);
		$file = lc $file if $Is83 or $Is_VMS;
		next if $outfiles{$file};
		print "  deleting $file\n" if ($Verbose>=2);
		my($deleted,$thistime);  # catch all versions on VMS
		do { $deleted += ($thistime = unlink $file) } while ($thistime);
		carp ("Unable to delete $file: $!") unless $deleted;
	    }
	    closedir($outdir);
	}
    }

    open(my $ts,">$al_idx_file") or
	carp ("AutoSplit: unable to create timestamp file ($al_idx_file): $!");
    print $ts "# Index created by AutoSplit for $filename\n";
    print $ts "#    (file acts as timestamp)\n";
    $last_package = '';
    for my $fqs (@subnames) {
	my($subname) = $fqs;
	$subname =~ s/.*:://;
	print $ts "package $package{$fqs};\n"
	    unless $last_package eq $package{$fqs};
	print $ts "sub $subname $proto{$fqs};\n";
	$last_package = $package{$fqs};
    }
    print $ts "1;\n";
    close($ts);

    _check_unique($filename, $Maxlen, 1, @outfiles);

    @outfiles;
}

sub _modpname ($) {
    my($package) = @_;
    my $modpname = $package;
    if ($^O eq 'MSWin32') {
	$modpname =~ s#::#\\#g; 
    } else {
	my @modpnames = ();
	while ($modpname =~ m#(.*?[^:])::([^:].*)#) {
	       push @modpnames, $1;
	       $modpname = $2;
         }
	$modpname = catfile(@modpnames, $modpname);
    }
    if ($Is_VMS) {
        $modpname = VMS::Filespec::unixify($modpname); # may have dirs
    }
    $modpname;
}

sub _check_unique {
    my($filename, $maxlen, $warn, @outfiles) = @_;
    my(%notuniq) = ();
    my(%shorts)  = ();
    my(@toolong) = grep(
			length(File::Basename::basename($_))
			> $maxlen,
			@outfiles
		       );

    foreach (@toolong){
	my($dir) = File::Basename::dirname($_);
	my($file) = File::Basename::basename($_);
	my($trunc) = substr($file,0,$maxlen);
	$notuniq{$dir}{$trunc} = 1 if $shorts{$dir}{$trunc};
	$shorts{$dir}{$trunc} = $shorts{$dir}{$trunc} ?
	    "$shorts{$dir}{$trunc}, $file" : $file;
    }
    if (%notuniq && $warn){
	print "$filename: some names are not unique when " .
	    "truncated to $maxlen characters:\n";
	foreach my $dir (sort keys %notuniq){
	    print " directory $dir:\n";
	    foreach my $trunc (sort keys %{$notuniq{$dir}}) {
		print "  $shorts{$dir}{$trunc} truncate to $trunc\n";
	    }
	}
    }
}

1;
__END__

# test functions so AutoSplit.pm can be applied to itself:
sub test1 ($)   { "test 1\n"; }
sub test2 ($$)  { "test 2\n"; }
sub test3 ($$$) { "test 3\n"; }
sub testtesttesttest4_1  { "test 4\n"; }
sub testtesttesttest4_2  { "duplicate test 4\n"; }
sub Just::Another::test5 { "another test 5\n"; }
sub test6       { return join ":", __FILE__,__LINE__; }
package Yet::Another::AutoSplit;
sub testtesttesttest4_1 ($)  { "another test 4\n"; }
sub testtesttesttest4_2 ($$) { "another duplicate test 4\n"; }
package Yet::More::Attributes;
sub test_a1 ($) : locked :locked { 1; }
sub test_a2 : locked { 1; }