From @moritz

sub f {
  gather for 1..10 {
  return if $_ == 3;
  take +$_;
  }
}
my @​x = f();

Output​:

No exception handler and no message
current instr.​: '&return' pc 18095 (src/builtins/Junction.pir​:404)
called from Sub '_block46' pc 373 (EVAL_1​:45279834)
called from Sub '_block39' pc 277 (EVAL_1​:45279680)
called from Sub 'perl6;GatherIterator;' pc 572757 (src/gen/core.pir​:100526)
called from Sub 'perl6;GatherIterator;get' pc 572737 (src/gen/core.pir​:0)
called from Sub 'perl6;Iterator;eager' pc 11606 (src/builtins/Role.pir​:87)
called from Sub 'perl6;Seq;!STORE' pc 14949 (src/builtins/Code.pir​:188)
called from Sub '_block14' pc 29 (EVAL_1​:0)
called from Sub '!YOU_ARE_HERE' pc 378767 (src/gen/core.pir​:29448)
called from Sub '!UNIT_START' pc 1400 (src/glue/run.pir​:21)
called from Sub 'perl6;PCT;HLLCompiler;eval' pc -1 ((unknown file)​:-1)
called from Sub 'perl6;PCT;HLLCompiler;evalfiles' pc 1318
(compilers/pct/src/PCT/HLLCompiler.pir​:714)
called from Sub 'perl6;PCT;HLLCompiler;command_line' pc 1504
(compilers/pct/src/PCT/HLLCompiler.pir​:801)
called from Sub 'perl6;Perl6;Compiler;main' pc -1 ((unknown file)​:-1)

I'd expect that to leave @​x empty, not die.

From @coke

On Tue May 18 11​:52​:31 2010, moritz wrote​:

sub f {
gather for 1..10 {
return if $_ == 3;
take +$_;
}
}
my @​x = f();

This now generates no output. Even if you add a 'say "alive" at the end.

--
Will "Coke" Coleda

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

From @moritz

On Tue May 18 11​:52​:31 2010, moritz wrote​:

sub f {
gather for 1..10 {
return if $_ == 3;
take +$_;
}
}
my @​x = f();

Now segfaults with this backtrace​:

#​0 0x00007ffff3dc998a in find_common_ctx () from dynext/perl6_ops.so
#​1 0x00007ffff3de0d75 in Parrot_perl6_return_from_routine_p () from
dynext/perl6_ops.so
#​2 0x00007ffff7a6d726 in runops_fast_core ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​3 0x00007ffff7a6d59a in runops_int ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​4 0x00007ffff7a55e4e in runops ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​5 0x00007ffff7a51706 in Parrot_pcc_invoke_from_sig_object ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​6 0x00007ffff7a45add in Parrot_ext_call ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​7 0x00007ffff7b22d48 in Parrot_Task_invoke ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​8 0x00007ffff7a516b2 in Parrot_pcc_invoke_from_sig_object ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​9 0x00007ffff7a45add in Parrot_ext_call ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​10 0x00007ffff7a7190d in Parrot_cx_outer_runloop ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​11 0x00007ffff7a7199d in Parrot_cx_begin_execution ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​12 0x00007ffff7a787f8 in Parrot_pf_execute_bytecode_program ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​13 0x00007ffff7a4154a in Parrot_api_run_bytecode ()
  from /nocrypt-home/moritz/source/rakudo/install/lib/libparrot.so.4.2.0
#​14 0x0000000000401540 in main ()

From @moritz

09​:47 < moritz> p6​: sub f { gather loop { take 1; return } }; say f
09​:47 <+p6eval> rakudo e75663​: OUTPUT«(signal SEGV)»

I expected an error along the lines of "Cannot return from exhausted
routine" (because by the time the return() is run, the function already
has returned a lazy list.

From @moritz

Now with a backtrace​:

(gdb) run
Starting program​: /home/moritz/p6/rakudo/perl6 -e sub\ f\(\)\ \{\
gather\ loop\ \{\ take\ 1\;\ return\ 1\ \}\ \}\;\ say\ f\(\)
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff37261ca in find_common_ctx () from dynext/perl6_ops.so
(gdb) bt
#​0 0x00007ffff37261ca in find_common_ctx () from dynext/perl6_ops.so
#​1 0x00007ffff373db82 in Parrot_perl6_return_from_routine_p () from
dynext/perl6_ops.so
#​2 0x00007ffff7a6ba16 in runops_fast_core () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​3 0x00007ffff7a6b88a in runops_int () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​4 0x00007ffff7a5355e in runops () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​5 0x00007ffff7a4ef0e in Parrot_pcc_invoke_from_sig_object () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​6 0x00007ffff7a433ca in Parrot_ext_call () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​7 0x00007ffff7b21568 in Parrot_Task_invoke () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​8 0x00007ffff7a4eebf in Parrot_pcc_invoke_from_sig_object () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​9 0x00007ffff7a433ca in Parrot_ext_call () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​10 0x00007ffff7a6fbfd in Parrot_cx_outer_runloop () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​11 0x00007ffff7a6fc8d in Parrot_cx_begin_execution () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​12 0x00007ffff7a76b58 in Parrot_pf_execute_bytecode_program () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​13 0x00007ffff7a3ed1a in Parrot_api_run_bytecode () from
/home/moritz/p6/rakudo/install/lib/libparrot.so.4.4.0
#​14 0x0000000000401550 in main ()
(gdb)

@moritz - Status changed from 'new' to 'open'

From @diakopter

jnthn says fixed in 3b15966​: marking testneeded.

14​:40 <+dalek> rakudo/nom​: 3b15966 | jnthn++ | src/ops/perl6.ops​:
14​:40 <+dalek> rakudo/nom​: Fix SEGV that arose from a return in a gather.
14​:40 <+dalek> rakudo/nom​: review​:
rakudo/rakudo@3b15966a49
14​:40 < jnthn> diakopter​: ^^
14​:41 < diakopter> jnthn++ # I'll update the ticket
14​:41 * jnthn guesses update means "tag testneeded"
14​:41 < diakopter> yeah

From @moritz

Now tested in S32-exceptions/misc.t

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