optional D::GD usage

[gitmo/Moo.git] / lib / Moo / _Utils.pm

diff --git a/lib/Moo/_Utils.pm b/lib/Moo/_Utils.pm
index 6b1a5b3..24fe665 100644 (file)
--- a/lib/Moo/_Utils.pm
+++ b/lib/Moo/_Utils.pm
@@ -1,24 +1,26 @@
 package Moo::_Utils;
 
+no warnings 'once'; # guard against -w
+
 sub _getglob { \*{$_[0]} }
 sub _getstash { \%{"$_[0]::"} }
 
-BEGIN {
-  *lt_5_8_3 = $] < 5.008003
-    ? sub () { 1 }
-    : sub () { 0 }
-  ;
-}
+use constant lt_5_8_3 => ( $] < 5.008003 ) ? 1 : 0;
+use constant can_haz_subname => eval { require Sub::Name };
 
 use strictures 1;
+use Module::Runtime qw(require_module);
 use base qw(Exporter);
 use Moo::_mro;
 
 our @EXPORT = qw(
     _getglob _install_modifier _load_module _maybe_load_module
-    _get_linear_isa
+    _get_linear_isa _getstash _install_coderef _name_coderef
+    _in_global_destruction
 );
 
+sub _in_global_destruction ();
+
 sub _install_modifier {
   my ($into, $type, $name, $code) = @_;
 
@@ -32,21 +34,21 @@ sub _install_modifier {
 
 our %MAYBE_LOADED;
 
-# _load_module is inlined in Role::Tiny - make sure to copy if you update it.
-
 sub _load_module {
   (my $proto = $_[0]) =~ s/::/\//g;
   return 1 if $INC{"${proto}.pm"};
   # can't just ->can('can') because a sub-package Foo::Bar::Baz
   # creates a 'Baz::' key in Foo::Bar's symbol table
-  return 1 if grep !/::$/, keys %{_getstash($_[0])||{}};
-  require "${proto}.pm";
+  my $stash = _getstash($_[0])||{};
+  return 1 if grep +(!ref($_) and *$_{CODE}), values %$stash;
+  require_module($_[0]);
   return 1;
 }
 
 sub _maybe_load_module {
   return $MAYBE_LOADED{$_[0]} if exists $MAYBE_LOADED{$_[0]};
   (my $proto = $_[0]) =~ s/::/\//g;
+  local $@;
   if (eval { require "${proto}.pm"; 1 }) {
     $MAYBE_LOADED{$_[0]} = 1;
   } else {
@@ -59,10 +61,80 @@ sub _maybe_load_module {
 }
 
 sub _get_linear_isa {
-    return mro::get_linear_isa($_[0]);
+  return mro::get_linear_isa($_[0]);
+}
+
+sub _install_coderef {
+  *{_getglob($_[0])} = _name_coderef(@_);
+}
+
+sub _name_coderef {
+  shift if @_ > 2; # three args is (target, name, sub)
+  can_haz_subname ? Sub::Name::subname(@_) : $_[1];
+}
+
+sub STANDARD_DESTROY {
+  my $self = shift;
+
+  my $e = do {
+    local $?;
+    local $@;
+    eval {
+      $self->DEMOLISHALL(_in_global_destruction);
+    };
+    $@;
+  };
+
+  no warnings 'misc';
+  die $e if $e; # rethrow
+}
+
+if (eval { require_module('Devel::GlobalDestruction') }) {
+  *_in_global_destruction = \&Devel::GlobalDestruction::in_global_destruction;
+} elsif (defined ${^GLOBAL_PHASE}) {
+  eval 'sub _in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }';
+} else {
+  eval <<'PP_IGD' or die $@;
+
+my ($in_global_destruction, $before_is_installed);
+
+sub _in_global_destruction () { $in_global_destruction }
+
+END {
+  # SpeedyCGI runs END blocks every cycle but somehow keeps object instances
+  # hence lying about it seems reasonable...ish
+  $in_global_destruction = 1 unless $CGI::SpeedyCGI::i_am_speedy;
+}
+
+# threads do not execute the global ENDs (it would be stupid). However
+# one can register a new END via simple string eval within a thread, and
+# achieve the same result. A logical place to do this would be CLONE, which
+# is claimed to run in the context of the new thread. However this does
+# not really seem to be the case - any END evaled in a CLONE is ignored :(
+# Hence blatantly hooking threads::create
+
+if ($INC{'threads.pm'}) {
+  my $orig_create = threads->can('create');
+  no warnings 'redefine';
+  *threads::create = sub {
+    { local $@; eval 'END { $in_global_destruction = 1 }' };
+    goto $orig_create;
+  };
+  $before_is_installed = 1;
 }
 
-our $_in_global_destruction = 0;
-END { $_in_global_destruction = 1 }
+# just in case threads got loaded after us (silly)
+sub CLONE {
+  unless ($before_is_installed) {
+    require Carp;
+    Carp::croak("You must load the 'threads' module before @{[ __PACKAGE__ ]}");
+  }
+}
+
+1;  # keep eval happy
+
+PP_IGD
+
+}
 
 1;