+
+ if (defined $is_debugging) {
+ $source = "Config::Perl::V version $Config::Perl::V::VERSION";
+ }
+ }
+
+ unless (defined $is_debugging) {
+ $is_debugging = 0;
+ $source = "%Config";
+
+ require Config;
+ my @fields = qw<ccflags cppflags optimize>;
+
+ for my $field (@fields) {
+ my $content = $Config::Config{$field};
+
+ while ($content =~ /(-DD?EBUGGING((?:=\S*)?))/g) {
+ my $extra = $2 || '';
+ if ($extra ne '=none') {
+ $is_debugging = 1;
+ $source = "\$Config{$field} =~ /$1/";
+ }
+ }
+ }
+ }
+
+ my $maybe_is = $is_debugging ? "is" : "is NOT";
+ _diag("According to $source, this $maybe_is a debugging perl");
+
+ return $is_debugging;
+}
+
+sub import {
+ shift;
+ my %args = @_;
+
+ my $level = $args{level};
+ $level = 1 unless defined $level;
+
+ if ("$]" < 5.013_004 and not $ENV{PERL_FORCE_TEST_THREADS}) {
+ _diag("perl 5.13.4 required to safely test global destruction");
+ return 0;
+ }
+
+ my $env_level = $ENV{PERL_DESTRUCT_LEVEL};
+ if (defined $env_level) {
+ no warnings 'numeric';
+ $env_level = int $env_level;
+ }
+
+ my $is_debugging = is_debugging_perl();
+ if ($is_debugging) {
+ if (defined $env_level) {
+ _diag("Global destruction level $env_level set by PERL_DESTRUCT_LEVEL (environment)");
+ return ($env_level >= $level) ? 1 : 0;