Possible GC bug in Rakudo (parrot r27449, r27451)

There appears to be a possible GC-related bug introduced to Parrot
prior to r27449 which is showing up in Rakudo.  Using the following
script (courtesy of Jonathan W):

--------------------------------
class Foo {
has $.x;
method boo { say $.x }
}

class Bar is Foo {
method set($v) { $.x = $v }
}

my Foo $u .= new(x => 5);
$u.boo;                    # 5

$u= Bar.new(Foo{ x => 12 });
$u.boo;                    # 12
$u.set(9);
$u.boo;                    # 9
--------------------------------

'perl6 obj_init.p6' results :

5
Segmentation fault

--------------------------------

'parrot ~/src/parrot/languages/perl6/perl6.pbc obj_init.p6' results:

cjfields:tests cjfields$ parrot ~/src/parrot/languages/perl6/perl6.pbc
obj_init.p6
5
get_pmc_keyed() not implemented in class 'Undef'
current instr.: '_block10' pc 137 (EVAL_13:46)
called from Sub 'parrot;PCT::HLLCompiler;eval' pc 785 (src/PCT/
HLLCompiler.pir:458)
called from Sub 'parrot;PCT::HLLCompiler;evalfiles' pc 1067 (src/PCT/
HLLCompiler.pir:587)
called from Sub 'parrot;PCT::HLLCompiler;command_line' pc 1246 (src/
PCT/HLLCompiler.pir:676)
called from Sub 'parrot;Perl6::Compiler;main' pc 9647 (perl6.pir:187)

--------------------------------

'parrot -G ~/src/parrot/languages/perl6/perl6.pbc obj_init.p6' results:

5
get_pmc_keyed() not implemented in class 'Any'
current instr.: '_block10' pc 137 (EVAL_13:46)
called from Sub 'parrot;PCT::HLLCompiler;eval' pc 785 (src/PCT/
HLLCompiler.pir:458)
called from Sub 'parrot;PCT::HLLCompiler;evalfiles' pc 1067 (src/PCT/
HLLCompiler.pir:587)
called from Sub 'parrot;PCT::HLLCompiler;command_line' pc 1246 (src/
PCT/HLLCompiler.pir:676)
called from Sub 'parrot;Perl6::Compiler;main' pc 9647 (perl6.pir:187)

--------------------------------

Note difference with Any (-G) vs Undef (no -G).  Not sure if it means
anything.

-chris

Chris Fields wrote:
> There appears to be a possible GC-related bug introduced to Parrot
> prior to r27449 which is showing up in Rakudo.  Using the following
> script (courtesy of Jonathan W):
> <snip>
After investigating a little, the breakage occurred in:
http://www.parrotvm.org/svn/parrot/revision?rev=27447

Basically, protoobjects didn't handle the switch-over to using the new
copy opcode for :pasttype('copy') nodes properly. Fixed in r27539, so
this example runs again.

Thanks,

Jonathan

That also fixes the bus error I reported in rt:

http://rt.perl.org/rt3/Public/Bug/Display.html?id=54004

I went ahead and closed that ticket out.  jonathan++

Thanks!

chris

On May 16, 2008, at 7:01 AM, Jonathan Worthington wrote:

> Chris Fields wrote: 
> After investigating a little, the breakage occurred in:
> http://www.parrotvm.org/svn/parrot/revision?rev=27447
>
> Basically, protoobjects didn't handle the switch-over to using the
> new copy opcode for :pasttype('copy') nodes properly. Fixed in
> r27539, so this example runs again.
>
> Thanks,
>
> Jonathan
>

Christopher Fields
Postdoctoral Researcher
Lab of Dr. Marie-Claude Hofmann
College of Veterinary Medicine
University of Illinois Urbana-Champaign