Attribute-Handlers: rework eval code

This makes the logic a bit simpler, and makes it easier to debug
as well. Reducing the amount of code that needs to be inside
the eval makes it easier to debug what is going on, especially
from an internals point of view (eg with -Dl enabled).

Author: demerphq

dist/Attribute-Handlers/lib/Attribute/Handlers.pm

@@ -4,9 +4,9 @@ use Carp;
 use warnings;
 use strict;
 our $AUTOLOAD;
-our $VERSION = '1.02'; # remember to update version in POD!
+our $VERSION = '1.03'; # remember to update version in POD!
 # $DB::single=1;
-
+my $debug= $ENV{DEBUG_ATTRIBUTE_HANDLERS} || 0;
 my %symcache;
 sub findsym {
 	my ($pkg, $ref, $type) = @_;
@@ -241,20 +241,33 @@ sub _apply_handler_AH_ {
 	my ($declaration, $phase) = @_;
 	my ($pkg, $ref, $attr, $data, $raw, $handlerphase, $filename, $linenum) = @$declaration;
 	return unless $handlerphase->{$phase};
-	# print STDERR "Handling $attr on $ref in $phase with [$data]\n";
+        print STDERR "Handling $attr on $ref in $phase with [$data]\n"
+            if $debug;
 	my $type = ref $ref;
 	my $handler = "_ATTR_${type}_${attr}";
 	my $sym = findsym($pkg, $ref);
 	$sym ||= $type eq 'CODE' ? 'ANON' : 'LEXICAL';
 	no warnings;
 	if (!$raw && defined($data)) {
 	    if ($data ne '') {
-		my $evaled = eval("package $pkg; no warnings; no strict;
-				   local \$SIG{__WARN__}=sub{die}; [$data]");
-		$data = $evaled unless $@;
+                # keeping the minimum amount of code inside the eval string
+                # makes debugging perl internals issues with this logic easier.
+                my $code= "package $pkg; my \$ref= [$data]; \$data= \$ref; 1";
+                print STDERR "Evaling: '$code'\n"
+                    if $debug;
+                local $SIG{__WARN__} = sub{ die };
+                no strict;
+                no warnings;
+                # Note we do not need
+                eval($code) or do {
+                    print STDERR "Eval failed: $@"
+                        if $debug;
+                };
 	    }
 	    else { $data = undef }
 	}
+
+        # now call the handler with the $data decoded (maybe)
 	$pkg->$handler($sym,
 		       (ref $sym eq 'GLOB' ? *{$sym}{ref $ref}||$ref : $ref),
 		       $attr,
@@ -300,7 +313,7 @@ Attribute::Handlers - Simpler definition of attribute handlers
 
 =head1 VERSION
 
-This document describes version 1.02 of Attribute::Handlers.
+This document describes version 1.03 of Attribute::Handlers.
 
 =head1 SYNOPSIS