&CORE::__CLASS__ returns bogus value (filename)

[mauke]

Description

&CORE::__CLASS__ should either fail cleanly (Undefined subroutine &CORE::__CLASS__ called or similar) or work and return a class name. Instead it returns the caller's filename.

Steps to Reproduce

use v5.36;
use experimental qw(class);

class Foo {
    method f1() { __CLASS__ }
    method f2() { &CORE::__CLASS__() }
    method f3() { \&CORE::__CLASS__ }
}

my $o = Foo->new;

say $o->f1;
say $o->f2;
say $o->f3->();

Output:

Foo
bug.pl
bug.pl

Expected behavior

Foo
Foo
Foo

... actually I'm not sure about the third one. I think that ought to be a runtime error, maybe?

[jkeenan]

Your program starts with use v5.36;. That suggested to me that I should try to run it with my perlbrew-installed perl-5.36.0 -- but I got exception there and at 5.38 as well.

$ perlbrew use perl-5.36.0
$ perl gh-23737-class.pl 
Can't enable unknown feature class at gh-23737-class.pl line 4.
BEGIN failed--compilation aborted at gh-23737-class.pl line 4.

$ perlbrew use perl-5.38.0
$ perl gh-23737-class.pl 
Bareword "__CLASS__" not allowed while "strict subs" in use at gh-23737-class.pl line 7.
Execution of gh-23737-class.pl aborted due to compilation errors.

I had to use 5.40 to get it to DWIM.

$ perlbrew use perl-5.40.1
$ perl gh-23737-class.pl 
Foo
gh-23737-class.pl
gh-23737-class.pl

Am I missing something?

[mauke]

That suggested to me that I should try to run it with my perlbrew-installed perl-5.36.0

Not my intention. My "default script template" starts with use v5.36 to enable strict/warnings/modern features with a single line of code, but any additional features (such as class) may require a newer perl (5.40.0 in this case).