~rsrchboy/+junk/ndn-perl

#!./miniperl

use strict;

use warnings;

use Config;

use constant IS_CROSS => defined $Config::Config{usecrosscompile} ? 1 : 0;

my $is_Win32 = $^O eq 'MSWin32';

my $is_VMS = $^O eq 'VMS';

my $is_Unix = !$is_Win32 && !$is_VMS;

my @ext_dirs = qw(cpan dist ext);

my $ext_dirs_re = '(?:' . join('|', @ext_dirs) . ')';

# This script acts as a simple interface for building extensions.

# It's actually a cut and shut of the Unix version ext/utils/makeext and the

# Windows version win32/build_ext.pl hence the two invocation styles.

# On Unix, it primarily used by the perl Makefile one extension at a time:

#

# d_dummy $(dynamic_ext): miniperl preplibrary FORCE

# 	@$(RUN) ./miniperl make_ext.pl --target=dynamic $@ MAKE=$(MAKE) LIBPERL_A=$(LIBPERL)

#

# On Windows or VMS,

# If '--static' is specified, static extensions will be built.

# If '--dynamic' is specified, dynamic extensions will be built.

# If '--nonxs' is specified, nonxs extensions will be built.

# If '--dynaloader' is specified, DynaLoader will be built.

# If '--all' is specified, all extensions will be built.

#

#    make_ext.pl "MAKE=make [-make_opts]" --dir=directory [--target=target] [--static|--dynamic|--all] +ext2 !ext1

#

# E.g.

# 

#     make_ext.pl "MAKE=nmake -nologo" --dir=..\ext

# 

#     make_ext.pl "MAKE=nmake -nologo" --dir=..\ext --target=clean

# 

#     make_ext.pl MAKE=dmake --dir=..\ext

# 

#     make_ext.pl MAKE=dmake --dir=..\ext --target=clean

# 

# Will skip building extensions which are marked with an '!' char.

# Mostly because they still not ported to specified platform.

# 

# If any extensions are listed with a '+' char then only those

# extensions will be built, but only if they aren't countermanded

# by an '!ext' and are appropriate to the type of building being done.

# An extensions follows the format of Foo/Bar, which would be extension Foo::Bar

# It may be deleted in a later release of perl so try to

# avoid using it for other purposes.

my (%excl, %incl, %opts, @extspec, @pass_through);

foreach (@ARGV) {

    if (/^!(.*)$/) {

	$excl{$1} = 1;

    } elsif (/^\+(.*)$/) {

	$incl{$1} = 1;

    } elsif (/^--([\w\-]+)$/) {

	$opts{$1} = 1;

    } elsif (/^--([\w\-]+)=(.*)$/) {

	push @{$opts{$1}}, $2;

    } elsif (/=/) {

	push @pass_through, $_;

    } elsif (length) {

	push @extspec, $_;

    }

}

my $static = $opts{static} || $opts{all};

my $dynamic = $opts{dynamic} || $opts{all};

my $nonxs = $opts{nonxs} || $opts{all};

my $dynaloader = $opts{dynaloader} || $opts{all};

# The Perl Makefile.SH will expand all extensions to

#	lib/auto/X/X.a  (or lib/auto/X/Y/Y.a if nested)

# A user wishing to run make_ext might use

#	X (or X/Y or X::Y if nested)

# canonise into X/Y form (pname)

foreach (@extspec) {

    if (s{^lib/auto/}{}) {

	# Remove lib/auto prefix and /*.* suffix

	s{/[^/]+\.[^/]+$}{};

    } elsif (s{^$ext_dirs_re/}{}) {

	# Remove ext/ prefix and /pm_to_blib suffix

	s{/pm_to_blib$}{};

	# Targets are given as files on disk, but the extension spec is still

	# written using /s for each ::

	tr!-!/!;

    } elsif (s{::}{\/}g) {

	# Convert :: to /

    } else {

	s/\..*o//;

    }

}

my $makecmd  = shift @pass_through; # Should be something like MAKE=make

unshift @pass_through, 'PERL_CORE=1';

my @dirs  = @{$opts{dir} || \@ext_dirs};

my $target   = $opts{target}[0];

$target = 'all' unless defined $target;

# Previously, $make was taken from config.sh.  However, the user might

# instead be running a possibly incompatible make.  This might happen if

# the user types "gmake" instead of a plain "make", for example.  The

# correct current value of MAKE will come through from the main perl

# makefile as MAKE=/whatever/make in $makecmd.  We'll be cautious in

# case third party users of this script (are there any?) don't have the

# MAKE=$(MAKE) argument, which was added after 5.004_03.

unless(defined $makecmd and $makecmd =~ /^MAKE=(.*)$/) {

    die "$0:  WARNING:  Please include MAKE=\$(MAKE) in \@ARGV\n";

}

# This isn't going to cope with anything fancy, such as spaces inside command

# names, but neither did what it replaced. Once there is a use case that needs

# it, please supply patches. Until then, I'm sticking to KISS

my @make = split ' ', $1 || $Config{make} || $ENV{MAKE};

if ($target eq '') {

    die "make_ext: no make target specified (eg all or clean)\n";

} elsif ($target !~ /^(?:all|clean|distclean|realclean|veryclean)$/) {

    # we are strict about what make_ext is used for because we emulate these

    # targets for simple modules:

    die "$0: unknown make target '$target'\n";

}

if (!@extspec and !$static and !$dynamic and !$nonxs and !$dynaloader)  {

    die "$0: no extension specified\n";

}

my $perl;

my %extra_passthrough;

if ($is_Win32) {

    require Cwd;

    require FindExt;

    my $build = Cwd::getcwd();

    $perl = $^X;

    if ($perl =~ m#^\.\.#) {

	my $here = $build;

	$here =~ s{/}{\\}g;

	$perl = "$here\\$perl";

    }

    (my $topdir = $perl) =~ s/\\[^\\]+$//;

    # miniperl needs to find perlglob and pl2bat

    $ENV{PATH} = "$topdir;$topdir\\win32\\bin;$ENV{PATH}";

    my $pl2bat = "$topdir\\win32\\bin\\pl2bat";

    unless (-f "$pl2bat.bat") {

	my @args = ($perl, "-I$topdir\\lib", ("$pl2bat.pl") x 2);

	print "@args\n";

	system(@args) unless IS_CROSS;

    }

    print "In $build";

    foreach my $dir (@dirs) {

	chdir($dir) or die "Cannot cd to $dir: $!\n";

	(my $ext = Cwd::getcwd()) =~ s{/}{\\}g;

	FindExt::scan_ext($ext);

	FindExt::set_static_extensions(split ' ', $Config{static_ext});

	chdir $build

	    or die "Couldn't chdir to '$build': $!"; # restore our start directory

    }

    my @ext;

    push @ext, FindExt::static_ext() if $static;

    push @ext, FindExt::dynamic_ext() if $dynamic;

    push @ext, FindExt::nonxs_ext() if $nonxs;

    push @ext, 'DynaLoader' if $dynaloader;

    foreach (sort @ext) {

	if (%incl and !exists $incl{$_}) {

	    #warn "Skipping extension $_, not in inclusion list\n";

	    next;

	}

	if (exists $excl{$_}) {

	    warn "Skipping extension $_, not ported to current platform";

	    next;

	}

	push @extspec, $_;

	if($_ eq 'DynaLoader' and $target !~ /clean$/) {

	    # No, we don't know why nmake can't work out the dependency chain

	    push @{$extra_passthrough{$_}}, 'DynaLoader.c';

	} elsif(FindExt::is_static($_)) {

	    push @{$extra_passthrough{$_}}, 'LINKTYPE=static';

	}

    }

    chdir '..'

	or die "Couldn't chdir to build directory: $!"; # now in the Perl build

}

elsif ($is_VMS) {

    $perl = $^X;

    push @extspec, (split ' ', $Config{static_ext}) if $static;

    push @extspec, (split ' ', $Config{dynamic_ext}) if $dynamic;

    push @extspec, (split ' ', $Config{nonxs_ext}) if $nonxs;

    push @extspec, 'DynaLoader' if $dynaloader;

}

{

    # Cwd needs to be built before Encode recurses into subdirectories.

    # Pod::Simple needs to be built before Pod::Functions

    # This seems to be the simplest way to ensure this ordering:

    my (@first, @other);

    foreach (@extspec) {

	if ($_ eq 'Cwd' || $_ eq 'Pod/Simple') {

	    push @first, $_;

	} else {

	    push @other, $_;

	}

    }

    @extspec = (@first, @other);

}

if ($Config{osname} eq 'catamount' and @extspec) {

    # Snowball's chance of building extensions.

    die "This is $Config{osname}, not building $extspec[0], sorry.\n";

}

foreach my $spec (@extspec)  {

    my $mname = $spec;

    $mname =~ s!/!::!g;

    my $ext_pathname;

    # Try new style ext/Data-Dumper/ first

    my $copy = $spec;

    $copy =~ tr!/!-!;

    # List/Util.xs lives in Scalar-List-Utils, Cwd.xs lives in PathTools

    $copy = 'Scalar-List-Utils' if $copy eq 'List-Util';

    $copy = 'PathTools'         if $copy eq 'Cwd';

    foreach my $dir (@ext_dirs) {

	if (-d "$dir/$copy") {

	    $ext_pathname = "$dir/$copy";

	    last;

	}

    }

    if (!defined $ext_pathname) {

	if (-d "ext/$spec") {

	    # Old style ext/Data/Dumper/

	    $ext_pathname = "ext/$spec";

	} else {

	    warn "Can't find extension $spec in any of @ext_dirs";

	    next;

	}

    }

    print "\tMaking $mname ($target)\n";

    build_extension($ext_pathname, $perl, $mname, $target,

		    [@pass_through, @{$extra_passthrough{$spec} || []}]);

}

sub build_extension {

    my ($ext_dir, $perl, $mname, $target, $pass_through) = @_;

    unless (chdir "$ext_dir") {

	warn "Cannot cd to $ext_dir: $!";

	return;

    }

    my $up = $ext_dir;

    $up =~ s![^/]+!..!g;

    $perl ||= "$up/miniperl";

    my $return_dir = $up;

    my $lib_dir = "$up/lib";

    $ENV{PERL_CORE} = 1;

    my $makefile;

    if ($is_VMS) {

	$makefile = 'descrip.mms';

	if ($target =~ /clean$/

	    && !-f $makefile

	    && -f "${makefile}_old") {

	    $makefile = "${makefile}_old";

	}

    } else {

	$makefile = 'Makefile';

    }

    if (-f $makefile) {

	open my $mfh, $makefile or die "Cannot open $makefile: $!";

	while (<$mfh>) {

	    # Plagiarised from CPAN::Distribution

	    last if /MakeMaker post_initialize section/;

	    next unless /^#\s+VERSION_FROM\s+=>\s+(.+)/;

	    my $vmod = eval $1;

	    my $oldv;

	    while (<$mfh>) {

		next unless /^XS_VERSION = (\S+)/;

		$oldv = $1;

		last;

	    }

	    last unless defined $oldv;

	    require ExtUtils::MM_Unix;

	    defined (my $newv = parse_version MM $vmod) or last;

	    if ($newv ne $oldv) {

		close $mfh or die "close $makefile: $!";

		_unlink($makefile);

		{

		    no warnings 'deprecated';

		    goto NO_MAKEFILE;

		}

	    }

	}

        if (IS_CROSS) {

            # If we're cross-compiling, it's possible that the host's

            # Makefiles are around.

            seek($mfh, 0, 0) or die "Cannot seek $makefile: $!";

            my $cross_makefile;

            while (<$mfh>) {

                # XXX This might not be throughout enough.

                # For example, it's possible to cause a false-positive

                # if cross compiling on and for the Raspberry Pi,

                # which is insane but plausible.

                # False positives are really not troublesome, though;

                # all they mean is that the module gets rebuilt.

                if (/^CC = \Q$Config{cc}\E/) {

                    $cross_makefile = 1;

                    last;

                }

            }

            if (!$cross_makefile) {

                print "Deleting non-Cross makefile\n";

                close $mfh or die "close $makefile: $!";

                _unlink($makefile);

            }

        }

    }

    if (!-f $makefile) {

	NO_MAKEFILE:

	if (!-f 'Makefile.PL') {

            unless (just_pm_to_blib($target, $ext_dir, $mname, $return_dir)) {

                # No problems returned, so it has faked everything for us. :-)

                chdir $return_dir || die "Cannot cd to $return_dir: $!";

                return;

            }

	    print "\nCreating Makefile.PL in $ext_dir for $mname\n";

	    my ($fromname, $key, $value);

	    if ($mname eq 'podlators') {

		# We need to special case this somewhere, and this is fewer

		# lines of code than a core-only Makefile.PL, and no more

		# complex

		$fromname = 'VERSION';

		$key = 'DISTNAME';

		$value = 'podlators';

		$mname = 'Pod';

	    } else {

		$key = 'ABSTRACT_FROM';

		# We need to cope well with various possible layouts

		my @dirs = split /::/, $mname;

		my $leaf = pop @dirs;

		my $leafname = "$leaf.pm";

		my $pathname = join '/', @dirs, $leafname;

		my @locations = ($leafname, $pathname, "lib/$pathname");

		unshift @locations, 'lib/IO/Compress/Base.pm' if $mname eq 'IO::Compress';

		foreach (@locations) {

		    if (-f $_) {

			$fromname = $_;

			last;

		    }

		}

		unless ($fromname) {

		    die "For $mname tried @locations in in $ext_dir but can't find source";

		}

		($value = $fromname) =~ s/\.pm\z/.pod/;

		$value = $fromname unless -e $value;

	    }

	    open my $fh, '>', 'Makefile.PL'

		or die "Can't open Makefile.PL for writing: $!";

	    printf $fh <<'EOM', $0, $mname, $fromname, $key, $value;

#-*- buffer-read-only: t -*-

# This Makefile.PL was written by %s.

# It will be deleted automatically by make realclean

use strict;

use ExtUtils::MakeMaker;

# This is what the .PL extracts to. Not the ultimate file that is installed.

# (ie Win32 runs pl2bat after this)

# Doing this here avoids all sort of quoting issues that would come from

# attempting to write out perl source with literals to generate the arrays and

# hash.

my @temps = 'Makefile.PL';

foreach (glob('scripts/pod*.PL')) {

    # The various pod*.PL extractors change directory. Doing that with relative

    # paths in @INC breaks. It seems the lesser of two evils to copy (to avoid)

    # the chdir doing anything, than to attempt to convert lib paths to

    # absolute, and potentially run into problems with quoting special

    # characters in the path to our build dir (such as spaces)

    require File::Copy;

    my $temp = $_;

    $temp =~ s!scripts/!!;

    File::Copy::copy($_, $temp) or die "Can't copy $temp to $_: $!";

    push @temps, $temp;

}

my $script_ext = $^O eq 'VMS' ? '.com' : '';

my %%pod_scripts;

foreach (glob('pod*.PL')) {

    my $script = $_;

    s/.PL$/$script_ext/i;

    $pod_scripts{$script} = $_;

}

my @exe_files = values %%pod_scripts;

WriteMakefile(

    NAME          => '%s',

    VERSION_FROM  => '%s',

    %-13s => '%s',

    realclean     => { FILES => "@temps" },

    (%%pod_scripts ? (

        PL_FILES  => \%%pod_scripts,

        EXE_FILES => \@exe_files,

        clean     => { FILES => "@exe_files" },

    ) : ()),

);

# ex: set ro:

EOM

	    close $fh or die "Can't close Makefile.PL: $!";

	    # As described in commit 23525070d6c0e51f:

	    # Push the atime and mtime of generated Makefile.PLs back 4

	    # seconds. In certain circumstances ( on virtual machines ) the

	    # generated Makefile.PL can produce a Makefile that is older than

	    # the Makefile.PL. Altering the atime and mtime backwards by 4

	    # seconds seems to resolve the issue.

	    eval {

        my $ftime = (stat('Makefile.PL'))[9] - 4;

        utime $ftime, $ftime, 'Makefile.PL';

	    };

        } elsif ($mname =~ /\A(?:Carp

                            |ExtUtils::CBuilder

                            |Safe

                            |Search::Dict)\z/x) {

            # An explicit list of dual-life extensions that have a Makefile.PL

            # for CPAN, but we have verified can also be built using the fakery.

            my ($problem) = just_pm_to_blib($target, $ext_dir, $mname, $return_dir);

            # We really need to sanity test that we can fake it.

            # Otherwise "skips" will go undetected, and the build slow down for

            # everyone, defeating the purpose.

            if (defined $problem) {

                if (-d "$return_dir/.git") {

                    # Get the list of files that git isn't ignoring:

                    my @files = `git ls-files --cached --others --exclude-standard 2>/dev/null`;

                    # on error (eg no git) we get nothing, but that's not a

                    # problem. The goal is to see if git thinks that the problem

                    # file is interesting, by getting a positive match with

                    # something git told us about, and if so bail out:

                    foreach (@files) {

                        chomp;

                        # We really need to sanity test that we can fake it.

                        # The intent is that this should only fail because

                        # you've just added a file to the dual-life dist that

                        # we can't handle. In which case you should either

                        # 1) remove the dist from the regex a few lines above.

                        # or

                        # 2) add the file to regex of "safe" filenames earlier

                        #    in this function, that starts with ChangeLog

                        die "FATAL - $0 has $mname in the list of simple extensions, but it now contains file '$problem' which we can't handle"

                            if $problem eq $_;

                    }

                    # There's an unexpected file, but it seems to be something

                    # that git will ignore. So fall through to the regular

                    # Makefile.PL handling code below, on the assumption that

                    # we won't get here for a clean build.

                }

                warn "WARNING - $0 is building $mname using EU::MM, as it found file '$problem'";

            } else {

                # It faked everything for us.

                chdir $return_dir || die "Cannot cd to $return_dir: $!";

                return;

            }

	}

        # We are going to have to use Makefile.PL:

	print "\nRunning Makefile.PL in $ext_dir\n";

	my @args = ("-I$lib_dir", 'Makefile.PL');

	if ($is_VMS) {

	    my $libd = VMS::Filespec::vmspath($lib_dir);

	    push @args, "INST_LIB=$libd", "INST_ARCHLIB=$libd";

	} else {

	    push @args, 'INSTALLDIRS=perl', 'INSTALLMAN1DIR=none',

		'INSTALLMAN3DIR=none';

	}

	push @args, @$pass_through;

	_quote_args(\@args) if $is_VMS;

	print join(' ', $perl, @args), "\n";

	my $code = system $perl, @args;

	warn "$code from $ext_dir\'s Makefile.PL" if $code;

	# Right. The reason for this little hack is that we're sitting inside

	# a program run by ./miniperl, but there are tasks we need to perform

	# when the 'realclean', 'distclean' or 'veryclean' targets are run.

	# Unfortunately, they can be run *after* 'clean', which deletes

	# ./miniperl

	# So we do our best to leave a set of instructions identical to what

	# we would do if we are run directly as 'realclean' etc

	# Whilst we're perfect, unfortunately the targets we call are not, as

	# some of them rely on a $(PERL) for their own distclean targets.

	# But this always used to be a problem with the old /bin/sh version of

	# this.

	if ($is_Unix) {

	    foreach my $clean_target ('realclean', 'veryclean') {

                fallback_cleanup($return_dir, $clean_target, <<"EOS");

cd $ext_dir

if test ! -f Makefile -a -f Makefile.old; then

    echo "Note: Using Makefile.old"

    make -f Makefile.old $clean_target MAKE='@make' @pass_through

else

    if test ! -f Makefile ; then

	echo "Warning: No Makefile!"

    fi

    make $clean_target MAKE='@make' @pass_through

fi

cd $return_dir

EOS

	    }

	}

    }

    if (not -f $makefile) {

	print "Warning: No Makefile!\n";

    }

    if ($is_VMS) {

	_quote_args($pass_through);

	@$pass_through = (

			  "/DESCRIPTION=$makefile",

			  '/MACRO=(' . join(',',@$pass_through) . ')'

			 );

    }

    if (!$target or $target !~ /clean$/) {

	# Give makefile an opportunity to rewrite itself.

	# reassure users that life goes on...

	my @args = ('config', @$pass_through);

	system(@make, @args) and print "@make @args failed, continuing anyway...\n";

    }

    my @targ = ($target, @$pass_through);

    print "Making $target in $ext_dir\n@make @targ\n";

    my $code = system(@make, @targ);

    die "Unsuccessful make($ext_dir): code=$code" if $code != 0;

    chdir $return_dir || die "Cannot cd to $return_dir: $!";

}

sub _quote_args {

    my $args = shift; # must be array reference

    # Do not quote qualifiers that begin with '/'.

    map { if (!/^\//) {

          $_ =~ s/\"/""/g;     # escape C<"> by doubling

          $_ = q(").$_.q(");

        }

    } @{$args}

    ;

}

#guarentee that a file is deleted or die, void _unlink($filename)

#xxx replace with _unlink_or_rename from EU::Install?

sub _unlink {

    1 while unlink $_[0];

    my $err = $!;

    die "Can't unlink $_[0]: $err" if -f $_[0];

}

# Figure out if this extension is simple enough that it would only use

# ExtUtils::MakeMaker's pm_to_blib target. If we're confident that it would,

# then do all the work ourselves (returning an empty list), else return the

# name of a file that we identified as beyond our ability to handle.

#

# While this is clearly quite a bit more work than just letting

# ExtUtils::MakeMaker do it, and effectively is some code duplication, the time

# savings are impressive.

sub just_pm_to_blib {

    my ($target, $ext_dir, $mname, $return_dir) = @_;

    my ($has_lib, $has_top, $has_topdir);

    my ($last) = $mname =~ /([^:]+)$/;

    my ($first) = $mname =~ /^([^:]+)/;

    my $pm_to_blib = $is_VMS ? 'pm_to_blib.ts' : 'pm_to_blib';

    foreach my $leaf (<*>) {

        if (-d $leaf) {

            $leaf =~ s/\.DIR\z//i

                if $is_VMS;

            next if $leaf =~ /\A(?:\.|\.\.|t|demo)\z/;

            if ($leaf eq 'lib') {

                ++$has_lib;

                next;

            }

            if ($leaf eq $first) {

                ++$has_topdir;

                next;

            }

        }

        return $leaf

            unless -f _;

        $leaf =~ s/\.\z//

            if $is_VMS;

        # Makefile.PL is "safe" to ignore because we will only be called for

        # directories that hold a Makefile.PL if they are in the exception list.

        next

            if $leaf =~ /\A(ChangeLog

                            |Changes

                            |LICENSE

                            |Makefile\.PL

                            |MANIFEST

                            |META\.yml

                            |\Q$pm_to_blib\E

                            |README

                            |README\.patching

                            |README\.release

                            )\z/xi; # /i to deal with case munging systems.

        if ($leaf eq "$last.pm") {

            ++$has_top;

            next;

        }

        return $leaf;

    }

    return 'no lib/'

        unless $has_lib || $has_top;

    die "Inconsistent module $mname has both lib/ and $first/"

        if $has_lib && $has_topdir;

    print "\nRunning pm_to_blib for $ext_dir directly\n";

    my %pm;

    if ($has_top) {

        my $to = $mname =~ s!::!/!gr;

        $pm{"$last.pm"} = "../../lib/$to.pm";

    }

    if ($has_lib || $has_topdir) {

        # strictly ExtUtils::MakeMaker uses the pm_to_blib target to install

        # .pm, pod and .pl files. We're just going to do it for .pm and .pod

        # files, to avoid problems on case munging file systems. Specifically,

        # _pm.PL which ExtUtils::MakeMaker should run munges to _PM.PL, and

        # looks a lot like a regular foo.pl (ie FOO.PL)

        my @found;

        require File::Find;

        unless (eval {

            File::Find::find({

                              no_chdir => 1,

                              wanted => sub {

                                  return if -d $_;

                                  # Bail out immediately with the problem file:

                                  die \$_

                                      unless -f _;

                                  die \$_

                                      unless /\A[^.]+\.(?:pm|pod)\z/i;

                                  push @found, $_;

                              }

                             }, $has_lib ? 'lib' : $first);

            1;

        }) {

            # Problem files aren't really errors:

            return ${$@}

                if ref $@ eq 'SCALAR';

            # But anything else is:

            die $@;

        }

        if ($has_lib) {

            $pm{$_} = "../../$_"

                foreach @found;

        } else {

            $pm{$_} = "../../lib/$_"

                foreach @found;

        }

    }

    # This is running under miniperl, so no autodie

    if ($target eq 'all') {

        require ExtUtils::Install;

        ExtUtils::Install::pm_to_blib(\%pm, '../../lib/auto');

        open my $fh, '>', $pm_to_blib

            or die "Can't open '$pm_to_blib': $!";

        print $fh "$0 has handled pm_to_blib directly\n";

        close $fh

            or die "Can't close '$pm_to_blib': $!";

	if ($is_Unix) {

            # Fake the fallback cleanup

            my $fallback

                = join '', map {s!^\.\./\.\./!!; "rm -f $_\n"} sort values %pm;

            foreach my $clean_target ('realclean', 'veryclean') {

                fallback_cleanup($return_dir, $clean_target, $fallback);

            }

        }

    } else {

        # A clean target.

        # For now, make the targets behave the same way as ExtUtils::MakeMaker

        # does

        _unlink($pm_to_blib);

        unless ($target eq 'clean') {

            # but cheat a bit, by relying on the top level Makefile clean target

            # to take out our directory lib/auto/...

            # (which it has to deal with, as cpan/foo/bar creates

            # lib/auto/foo/bar, but the EU::MM rule will only

            # rmdir lib/auto/foo/bar, leaving lib/auto/foo

            _unlink($_)

                foreach sort values %pm;

        }

    }

    return;

}

sub fallback_cleanup {

    my ($dir, $clean_target, $contents) = @_;

    my $file = "$dir/$clean_target.sh";

    open my $fh, '>>', $file or die "open $file: $!";

    # Quite possible that we're being run in parallel here.

    # Can't use Fcntl this early to get the LOCK_EX

    flock $fh, 2 or warn "flock $file: $!";

    print $fh $contents or die "print $file: $!";

    close $fh or die "close $file: $!";

}