Confusion in SPESH about return

[p6rt]

Migrated from rt.perl.org#128368 (status was 'resolved')

Searchable as RT128368$

[p6rt]

From @lizmat

m​: class A { has $.foo; method foo { return $!foo } }; my $a = A.new(foo => 42); for ^158 { $a.foo } # first value it breaks on 158
  rakudo-moar 87e91c​: OUTPUT«Attempt to return outside of any Routine␤ in block <unit> at /tmp/9NqzgIZLo_ line 1␤␤»

m​: class A { has $.foo; method foo { return $!foo } }; my $a = A.new(foo => 42); for ^157 { $a.foo } # 157 is ok
  rakudo-moar 87e91c​: ( no output )

With MVM_SPESH_DISABLE=1, this is all ok.

Tux++ for the initial canary!

[p6rt]

From @lizmat

It appears we can golf this down further​:

m​: class A { method foo { return 42 } }; my $a = A.new; for ^157 { $a.foo } # still smaller golf, no attributes neede
  rakudo-moar 87e91c​: ( no output )
m​: class A { method foo { return 42 } }; my $a = A.new; for ^158 { $a.foo } # at 158 it fails
  rakudo-moar 87e91c​: OUTPUT«Attempt to return outside of any Routine␤ in block <unit> at /tmp/OZc4EqaZLv line 1␤␤»
m​: sub foo() { return 42 }; for ^157 { foo } # still smaller golf
  rakudo-moar 87e91c​: ( no output )
m​: sub foo() { return 42 }; for ^158 { foo } # fails at 158
  rakudo-moar 87e91c​: OUTPUT«Attempt to return outside of any Routine␤ in block <unit> at /tmp/tOCcim2lY1 line 1␤␤»

Of course, if there had been a Routine outside, this error would have been silent! Just done the wrong thing!

[p6rt]

From @zoffixznet

For records,

The tests for this ticket already exist at https://github.com/perl6/roast/blob/a9597e6781703f012399dd5a1f988028e2279afc/integration/weird-errors.t#L205

As stated in commit Raku/roast@a9597e6 this bug is currently worked-around rather than fixed entirely.

[p6rt]

The RT System itself - Status changed from 'new' to 'open'

[p6rt]

From @jnthn

On Fri Jul 08 22​:00​:54 2016, cpan@​zoffix.com wrote​:

For records,

The tests for this ticket already exist at
https://github.com/perl6/roast/blob/a9597e6781703f012399dd5a1f988028e2279afc/integration/weird-
errors.t#L205

As stated in commit
Raku/roast@a9597e6
this bug is currently worked-around rather than fixed entirely.

From a Perl 6 perspective, this is sufficiently fixed. The workaround is safe, it just means MoarVM can't optimize stuff so well as would be nice. But that doesn't need an RT here.

[p6rt]

@jnthn - Status changed from 'open' to 'resolved'