use strict;

my @manifest;
my $recurse=0;
for (@ARGV) {
  if (/^-M(.*)$/) {
    push @manifest, $1;
  }
  elsif (s/^-r$//) {$recurse=1}
  elsif (s/^-R$//) {$recurse=0}
}

my @files = ();

sub getf {
  my ($p) = @_;
  my @res = ();
  opendir FDIR, $p;
  for (readdir FDIR) {
    next if /^\.*$/;
    if (-f "$p/$_") {push @res,"$p/$_"}
    elsif (-d "$p/$_") {push @res,getf("$p/$_")}
  }
  closedir FDIR;
  return @res;
}

if ($recurse) {
  my @f;
  for (@ARGV) {
    s/[\/\\]+$//;
    if (/^(.*?)[\\\/]([^\\\/]+)$/) {
      my ($path, $patt) = ($1,$2);
      push @f, getf($path);
      $patt =~ s/([.+])/\\$1/g;
      $patt =~ s/\?/./g;
      $patt =~ s/\*/(?:.*?)/g;
      push @files, grep {/[\/\\]$patt$/} @f;
    }
    elsif (-f) {
      push @files, $_;
    }
  }
}
else {
  push @files, @ARGV;
}

for (@manifest) {
  open FIN, "<$_";
  push @files, grep {!/^#/ and !/^\s*$/} <FIN>;
  close FIN;
}

undef $/;

sub retr {
  my $str = shift;
  for ($str) {
    s/(["\\])/\\$1/g;
    s/(\r?\n)/\\n\\$1/g;
  }
  return $str;
}

for (@files) {
  next unless -f;
  my $bb = 0;
  open FIN, "<$_";
  binmode FIN;
  my $f = <FIN>;
  my $f0 = $f;
  close FIN;
  if (
    $f=~s/^(#ifdef PERL_SOURCE((?:_S)?))(\r?\n)(.*?)#else(.*?)#endif/
     ((index($4.$5,"#ifdef")>-1) or (index($4.$5,"#else")>-1)) ? $& :
     "$1$3$4#else${3}PERL_EVAL$2(\"\\$3".retr($4)."\");$3#endif"
     /megs
  ) {
    $bb = 1;
  }
  if (
    $f=~s/^(#ifdef PERL_SOURCE((?:_S)?))(\r?\n)(.*?)#endif/
     ((index($4,"#ifdef")>-1) or (index($4,"#else")>-1)) ? $& :
     "$1$3$4#else${3}PERL_EVAL$2(\"\\$3".retr($4)."\");$3#endif"
     /megs
  ) {
    $bb = 1;
  }
  if ($bb and $f0 ne $f) {
    print STDERR ">>>$_<<<\n";
    open FOUT, ">$_";
    binmode FOUT;
    print FOUT $f;
    close FOUT;
  }
  else {
    print STDERR "   $_\n";
  }
}
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