I can't HAS stub?

[kazcw]

use NativeCall;
class MyStub is repr(｢CStruct｣) { ... }
class SpecialDelivery:«💣» is repr(｢CStruct｣) {
    HAS MyStub $.stubby;
}

Segmentation fault

[kazcw]

I could understand the compiler not being happy with what I was trying to do 🐟, but segfaulting seems a bit much

[kazcw]

This is probably for the same reason:

use NativeCall;
class Oops is repr(｢CStruct｣) { HAS Oops $.more; }

Segmentation fault

[MasterDuke17]

dan@hermes:~/p6$ pg6 -e 'use NativeCall;
> 
> class Oops is repr(｢CStruct｣) { HAS Oops $.more; }'
================================================================================================
This is Rakudo Perl 6 running in the  debugger, which often allows the user to generate useful back-
traces to debug or report issues in Rakudo, the MoarVM backend or the currently running code.

This Rakudo version is 2019.03.1.574.gee.2.f.2.d.2.df built on MoarVM version 2019.05.36.ge.865.f.43.df,
running on ubuntu (19.04.Disco.Dingo) / linux (17.Ubuntu.SMP.Wed.May.15.10.52.21.UTC.2019)

Type `bt full` to generate a backtrace if applicable, type `q` to quit or `help` for help.
------------------------------------------------------------------------------------------------
Reading symbols from /home/dan/Source/perl6/install/bin/perl6-m...
Starting program: /home/dan/Source/perl6/install/bin/perl6-m -e use\ NativeCall\;'
''
'class\ Oops\ is\ repr\(｢CStruct｣\)\ \{\ HAS\ Oops\ \$.more\;\ \}
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff6ff6700 (LWP 21302)]

Thread 1 "perl6-m" received signal SIGSEGV, Segmentation fault.
compute_allocation_strategy (st=<optimized out>, repr_data=<optimized out>, repr_info=<optimized out>, tc=0x55555555ae90) at src/6model/reprs/CStruct.c:263
263                             bits                                      = cppstruct_repr_data->struct_size * 8;
(gdb) bt
#0  compute_allocation_strategy (st=<optimized out>, repr_data=<optimized out>, repr_info=<optimized out>, tc=0x55555555ae90) at src/6model/reprs/CStruct.c:263
#1  compose (tc=0x55555555ae90, st=0x7fffefad87f0, repr_info=<optimized out>) at src/6model/reprs/CStruct.c:382
#2  0x00007ffff798af0d in MVM_interp_run (tc=tc@entry=0x55555555ae90, initial_invoke=0x0, invoke_data=0x2) at src/core/interp.c:2527
#3  0x00007ffff7a88895 in MVM_vm_run_file (instance=0x55555555a430, filename=<optimized out>) at src/moar.c:444
#4  0x0000555555555698 in main (argc=<optimized out>, argv=0x7fffffffde98) at src/vm/moar/runner/main.c:363
(gdb) call MVM_dump_backtrace(tc)
   at gen/moar/Metamodel.nqp:1674  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Metamodel.moarvm:compose_repr)
 from gen/moar/Metamodel.nqp:3431  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Metamodel.moarvm:compose)
 from src/Perl6/World.nqp:3289  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/World.moarvm:)
 from src/Perl6/World.nqp:5350  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/World.moarvm:)
 from src/Perl6/World.nqp:5346  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/World.moarvm:ex-handle)
 from src/Perl6/World.nqp:3288  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/World.moarvm:pkg_compose)
 from gen/moar/Perl6-Actions.nqp:3239  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Actions.moarvm:package_def)
 from gen/moar/stage2/QRegex.nqp:1598  (/home/dan/Source/perl6/install/share/nqp/lib/QRegex.moarvm:!cursor_pass)
 from gen/moar/Perl6-Grammar.nqp:2174  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:package_def)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:package_declarator:sym<class>)
 from gen/moar/stage2/QRegex.nqp:1697  (/home/dan/Source/perl6/install/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:package_declarator)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:term:sym<package_declarator>)
 from gen/moar/stage2/QRegex.nqp:1697  (/home/dan/Source/perl6/install/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:term)
 from gen/moar/Perl6-Grammar.nqp:3639  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:termish)
 from gen/moar/stage2/NQPHLL.nqp:1056  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:EXPR)
 from gen/moar/Perl6-Grammar.nqp:3675  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:EXPR)
 from gen/moar/Perl6-Grammar.nqp:956  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:statement)
 from gen/moar/Perl6-Grammar.nqp:884  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:statementlist)
 from gen/moar/stage2/NQPHLL.nqp:1278  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:LANG)
 from gen/moar/Perl6-Grammar.nqp:1320  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:FOREIGN_LANG)
 from gen/moar/Perl6-Grammar.nqp:826  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:comp_unit)
 from gen/moar/Perl6-Grammar.nqp:555  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Grammar.moarvm:TOP)
 from gen/moar/stage2/QRegex.nqp:2302  (/home/dan/Source/perl6/install/share/nqp/lib/QRegex.moarvm:parse)
 from gen/moar/stage2/NQPHLL.nqp:2099  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:parse)
 from gen/moar/stage2/NQPHLL.nqp:2019  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:execute_stage)
 from gen/moar/stage2/NQPHLL.nqp:2052  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:run)
 from gen/moar/stage2/NQPHLL.nqp:2044  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:)
 from gen/moar/stage2/NQPHLL.nqp:2039  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:compile)
 from gen/moar/stage2/NQPHLL.nqp:1729  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:eval)
 from gen/moar/stage2/NQPHLL.nqp:1862  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:)
 from gen/moar/stage2/NQPHLL.nqp:1861  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:command_eval)
 from src/Perl6/Compiler.nqp:52  (/home/dan/Source/perl6/install/share/perl6/lib/Perl6/Compiler.moarvm:command_eval)
 from gen/moar/stage2/NQPHLL.nqp:1842  (/home/dan/Source/perl6/install/share/nqp/lib/NQPHLL.moarvm:command_line)
 from gen/moar/main.nqp:82  (/home/dan/Source/perl6/install/share/perl6/runtime/perl6.moarvm:MAIN)
 from gen/moar/main.nqp:47  (/home/dan/Source/perl6/install/share/perl6/runtime/perl6.moarvm:<mainline>)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/runtime/perl6.moarvm:<main>)
 from <unknown>:1  (/home/dan/Source/perl6/install/share/perl6/runtime/perl6.moarvm:<entry>)
(gdb)

================================================================================================
This is Rakudo Perl 6 running in valgrind, a tool for debugging and profiling programs.
Running a program in valgrind usually takes *a lot* more time than running it directly,
so please be patient.
Valgrind options can be added with MVM_VALGRIND_OPTS environment variable.

This Rakudo version is 2019.03.1.574.gee.2.f.2.d.2.df built on MoarVM version 2019.05.36.ge.865.f.43.df,
running on ubuntu (19.04.Disco.Dingo) / linux (17.Ubuntu.SMP.Wed.May.15.10.52.21.UTC.2019)
------------------------------------------------------------------------------------------------
==21403== Memcheck, a memory error detector
==21403== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==21403== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==21403== Command: /home/dan/Source/perl6/install/bin/perl6-m -e use\ NativeCall;\ class\ Oops\ is\ repr(___CStruct___)\ {\ HAS\ Oops\ $.more;\ }
==21403== 
==21403== Invalid read of size 4
==21403==    at 0x4AA047F: compute_allocation_strategy (CStruct.c:263)
==21403==    by 0x4AA047F: compose (CStruct.c:382)
==21403==    by 0x4A2CF0C: MVM_interp_run (interp.c:2527)
==21403==    by 0x4B2A894: MVM_vm_run_file (moar.c:444)
==21403==    by 0x109697: main (main.c:363)
==21403==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
==21403== 
==21403== 
==21403== Process terminating with default action of signal 11 (SIGSEGV)
==21403==  Access not within mapped region at address 0x0
==21403==    at 0x4AA047F: compute_allocation_strategy (CStruct.c:263)
==21403==    by 0x4AA047F: compose (CStruct.c:382)
==21403==    by 0x4A2CF0C: MVM_interp_run (interp.c:2527)
==21403==    by 0x4B2A894: MVM_vm_run_file (moar.c:444)
==21403==    by 0x109697: main (main.c:363)
==21403==  If you believe this happened as a result of a stack
==21403==  overflow in your program's main thread (unlikely but
==21403==  possible), you can try to increase the size of the
==21403==  main thread stack using the --main-stacksize= flag.
==21403==  The main thread stack size used in this run was 8388608.
==21403== 
==21403== HEAP SUMMARY:
==21403==     in use at exit: 71,027,333 bytes in 232,926 blocks
==21403==   total heap usage: 343,326 allocs, 110,400 frees, 163,248,863 bytes allocated
==21403== 
==21403== LEAK SUMMARY:
==21403==    definitely lost: 96 bytes in 2 blocks
==21403==    indirectly lost: 88 bytes in 5 blocks
==21403==      possibly lost: 237,032 bytes in 4,232 blocks
==21403==    still reachable: 70,790,117 bytes in 228,687 blocks
==21403==         suppressed: 0 bytes in 0 blocks
==21403== Rerun with --leak-check=full to see details of leaked memory
==21403== 
==21403== For counts of detected and suppressed errors, rerun with: -v
==21403== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

[kazcw]

Is there documentation on the runtime way to define a class? The MOP page is pretty light. I'm trying to write a test case, but "passing" means throwing an exception when the type is composed (rather than segfaulting), so I need to do the equivalent of this:

class OopsUnion is repr(｢CUnion｣) { HAS OopsUnion $.more; }
class OopsStruct is repr(｢CStruct｣) { HAS OopsStruct $.more; }
class OopsPPStruct is repr(｢CPPStruct｣) { HAS OopsPPStruct $.more; }

but at runtime so I can catch the exception...