--- AnyEvent/constants.pl.PL	2010/03/12 23:30:06	1.2
+++ AnyEvent/constants.pl.PL	2017/02/13 14:51:42	1.16
@@ -1,26 +1,85 @@
 #! perl
 
-open STDOUT, ">$ARGV[0]~"
-   or die "$ARGV[0]~: $!";
+# this file is unfortunately only executed at Makefile.PL time
+
+my ($fh, $oldstdout);
+
+BEGIN {
+   open $fh, ">lib/AnyEvent/constants.pl"
+      or die "lib/AnyEvent/constants.pl: $!\n";
+
+   $oldstdout = select $fh;
+
+   print "# automatically generated from constants.pl.PL\n";
+}
+
+{
+   # from common::sense 3.74
+   use strict qw(vars subs);
+   no warnings;
+   use warnings qw(FATAL closed threads internal debugging pack malloc portable prototype
+                   inplace io pipe unpack glob digit printf
+                   layer reserved taint closure semicolon);
+   no warnings qw(exec newline unopened);
+
+   BEGIN {
+      print "sub AnyEvent::common_sense {\n";
+      printf "   local \$^W;\n";
+      printf "   \${^WARNING_BITS} ^= \${^WARNING_BITS} ^ \"%s\";\n",
+             join "", map "\\x$_", unpack "(H2)*", ${^WARNING_BITS};
+      # use strict, use utf8;
+      printf "   \$^H |= 0x%x;\n", $^H;
+      print "}\n";
+   }
+}
+
+use Config;
+
+print "# generated for perl $] built for $Config{archname}\n";
+
+# when built as part of perl, these are not available
+BEGIN { eval "use Socket ()" }
+BEGIN { eval "use Fcntl  ()" }
+BEGIN { eval "use POSIX  ()" }
 
 sub i($$) {
-   print "sub $_[0] () { ", $_[1]*1, " }\n";
+   print "sub $_[0](){", $_[1]*1, "}\n";
+}
+
+sub n($$) {
+   print "sub $_[0](){", (defined $_[1] ? $_[1]*1 : "undef"), "}\n";
 }
 
 print "package AnyEvent;\n";
 
 our $WIN32 = $^O =~ /mswin32/i;
 
-
+# used a lot
 i CYGWIN => $^O =~ /cygwin/i;
 i WIN32  => $WIN32;
 
-use Fcntl ();
+# add these purely to avoid loading Fcntl, which is slow and bloated.
+
+i F_SETFD    => eval { Fcntl::F_SETFD() } || 2;
+i F_SETFL    => eval { Fcntl::F_SETFL() } || 4;
+i O_NONBLOCK => eval { Fcntl::O_NONBLOCK() } || 04000;
+i FD_CLOEXEC => eval { Fcntl::FD_CLOEXEC() } || 1;
+
+print "package AnyEvent::Base;\n";
 
-i F_SETFL    => eval { Fcntl::F_SETFL() };
-i F_SETFD    => eval { Fcntl::F_SETFD() };
-i O_NONBLOCK => eval { Fcntl::O_NONBLOCK() };
-i FD_CLOEXEC => eval { Fcntl::FD_CLOEXEC() };
+# add these purely to avoid loading POSIX, which is slow and bloated.
+
+i WNOHANG    => eval { POSIX::WNOHANG() } || 1;
+
+print "package AnyEvent::IO;\n";
+
+i O_RDONLY   => eval { Fcntl::O_RDONLY() } || 0;
+i O_WRONLY   => eval { Fcntl::O_WRONLY() } || 1;
+i O_RDWR     => eval { Fcntl::O_RDWR  () } || 2;
+i O_CREAT    => eval { Fcntl::O_CREAT () } || 64;
+i O_EXCL     => eval { Fcntl::O_EXCL  () } || 128;
+i O_TRUNC    => eval { Fcntl::O_TRUNC () } || 512;
+i O_APPEND   => eval { Fcntl::O_APPEND() } || 1024;
 
 print "package AnyEvent::Util;\n";
 
@@ -38,17 +97,18 @@
 
 my $af_inet6;
 
-$af_inet6 ||= eval { require Socket ; Socket::AF_INET6 () };
-$af_ine6t ||= eval { require Socket6; Socket6::AF_INET6() };
+$af_inet6 ||= eval {                  Socket::AF_INET6 () }; # where it should be
+$af_inet6 ||= eval { require Socket6; Socket6::AF_INET6() }; # where it actually is ...
 
-# uhoh
+# ... or isn't, because nobody has it installed
 $af_inet6 ||= 10 if $^O =~ /linux/;
 $af_inet6 ||= 23 if $^O =~ /cygwin/i;
 $af_inet6 ||= 23 if AnyEvent::WIN32;
 $af_inet6 ||= 24 if $^O =~ /openbsd|netbsd/;
 $af_inet6 ||= 28 if $^O =~ /freebsd/;
 
-#TODO: WSAxxx, EDOM/ESPIPE
+#TODO: EDOM/ESPIPE
+#TODO: maybe move socket stuff to Socket::?
 
 i _AF_INET6     => $af_inet6;
 #i AF_UNIX      => Socket::AF_UNIX ();
@@ -60,7 +120,86 @@
 #i SO_OOBINLINE => Socket::SO_OOBINLINE ();
 #i IPPROTO_TCP  => Socket::IPPROTO_TCP ();
 
+print "package AnyEvent::Socket;\n";
+
+# more hardcoded os-specific constants - none
+# of these are available via any known module, but we
+# are forward-looking and try Socket:: anyways.
+my %const;
+
+while (<DATA>) {
+   my ($os, $name, $default) = split /\s+/;
+
+   $const{$name} ||= undef; # make sure it exists
+
+   next unless $os eq $^O;
+
+   my $value = eval "Socket::$name ()";
+   $value = eval $default unless defined $value;
+
+   $const{$name} = $value;
+}
+
+for my $k (sort keys %const) {
+   n $k, $const{$k};
+}
+
 print "1;\n";
 
-close STDOUT;
-rename "$ARGV[0]~", $ARGV[0];
+close $fh;
+select $oldstdout;
+
+1
+
+__DATA__
+linux	TCP_MAXSEG	2
+linux	TCP_CORK	3
+linux	TCP_KEEPIDLE	4
+linux	TCP_KEEPINTVL	5
+linux	TCP_KEEPCNT	6
+linux	TCP_SYNCNT	7
+linux	TCP_LINGER2	8
+linux	TCP_DEFER_ACCEPT	9
+linux	TCP_WINDOW_CLAMP	10
+linux	TCP_INFO	11
+linux	TCP_QUICKACK	12
+linux	TCP_CONGESTION	13
+linux	TCP_MD5SIG	14
+linux	TCP_FASTOPEN	23
+linux	MSG_DONTWAIT	0x0040
+linux	MSG_NOSIGNAL	0x4000
+linux	MSG_MORE	0x8000
+linux	MSG_FASTOPEN	0x20000000
+netbsd	TCP_MAXSEG	2
+netbsd	TCP_KEEPIDLE	3
+netbsd	TCP_NOPUSH	4
+netbsd	TCP_KEEPINTVL	5
+netbsd	TCP_KEEPCNT	6
+netbsd	TCP_KEEPINIT	7
+netbsd	TCP_NOOPT	8
+netbsd	TCP_MD5SIG	0x10
+netbsd	TCP_CONGESTION	0x20
+netbsd	MSG_NOSIGNAL	0x0400
+cygwin	TCP_MAXSEG	0x02
+cygwin	TCP_NOPUSH	0x04
+cygwin	TCP_NOOPT	0x08
+freebsd	TCP_MAXSEG	0x02
+freebsd	TCP_NOPUSH	0x04
+freebsd	TCP_NOOPT	0x08
+freebsd	TCP_MD5SIG	0x10
+freebsd	TCP_INFO	0x20
+freebsd	TCP_CONGESTION	0x40
+freebsd	MSG_NOSIGNAL	0x20000
+solaris	TCP_CORK	0x18
+solaris	TCP_LINGER2	0x1C
+solaris	TCP_INIT_CWND	0x15
+solaris	TCP_KEEPALIVE	0x8
+solaris	TCP_MAXSEG	0x02
+openbsd	TCP_MAXSEG	0x02
+openbsd	TCP_MD5SIG	0x04
+openbsd	TCP_SACK_ENABLE	0x08
+darwin	TCP_MAXSEG	0x02
+darwin	TCP_NOPUSH	0x04
+darwin	TCP_NOOPT	0x08
+darwin	TCP_KEEPALIVE	0x10
+darwin	TCP_CONNECTIONTIMEOUT	0x20