In some cases you could use B::Deparse, e.g. via Data::Dumper:

use Data::Dumper;
$Data::Dumper::Deparse = 1;

sub foo {
    my ($foo) = @_;
    print "foo called with $foo\n";
    print "going to call bar()...\n";
    bar();
}

sub bar {
    my $caller = (caller 1)[3];
    print Dumper \&$caller;
}

foo(42);
[download]

$ ./895386.pl
foo called with 42
going to call bar()...
$VAR1 = sub {
            my($foo) = @_;
            print "foo called with $foo\n";
            print "going to call bar()...\n";
            bar();
        };
[download]