# New Ticket Created by Will Coleda
# Please include the string: [perl #51478]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=51478 >
in PDD17, the following program (which prints "b\n" in trunk), dies:
$ ../../parrot tcl.pbc -e "puts [concat {expand}[lindex {a b} 1]]"
argument doesn't array.
This exception is coming from src/inter_call.c:374
369 dod_register_pmc(interp, st->key);
370 }
371 else {
372 /* src ought to be an array */
373 if (!VTABLE_does(interp, p_arg, CONST_STRING(interp, "array")))
374 real_exception(interp, NULL, E_ValueError,
"argument doesn't array");
375 }
376
377 st->src.mode |= CALL_STATE_FLATTEN;
378 st->src.slurp = p_arg;
breaking at 374..
(gdb) p *p_arg
$1 = {cache = {_b = {_bufstart = 0x835a1ac, _buflen = 3735928559}, _ptrs = {
_struct_val = 0x835a1ac, _pmc_val = 0xdeadbeef}, _i = {
_int_val = 137732524, _int_val2 = -559038737},
_num_val = -1.1885954149046845e+148, _string_val = 0x835a1ac},
flags = 1146095104, vtable = 0x808a6a0, data = 0x80bc008,
pmc_ext = 0x81add58, real_self = 0x835a1c8}
(gdb) p p_arg->vtable->base_type
$3 = 61
So, the PMC is a Parrot_Object, and since the vtable is healthy, I
assume this isn't a GC issue.
If I try to ask the PMC what it's type is (so I can figure out where
it came from), I get a segfault
(gdb) p p_arg->vtable->name(interp,p_arg)
#BOOM
So I set a conditional breakpoint on pmc_new and did a bt to find that
this particular PMC was created during a thaw.
(gdb) b src/pmc_new.c:71 if pmc==0x835a1c8
#0 pmc_new (interp=0x804f008, base_type=34) at src/pmc.c:71
#1 0xb7c19fd7 in ft_init (interp=0x804f008, info=0xbff6d228)
at src/pmc_freeze.c:958
#2 0xb7c1a081 in todo_list_init (interp=0x804f008, info=0xbff6d228)
at src/pmc_freeze.c:983
#3 0xb7c1b1e3 in run_thaw (interp=0x804f008, image=0x8326cd8,
what=VISIT_THAW_NORMAL) at src/pmc_freeze.c:1680
#4 0xb7c1b490 in Parrot_thaw (interp=0x804f008, image=0x8326cd8)
at src/pmc_freeze.c:1808
#5 0xb7c15da0 in PackFile_Constant_unpack_pmc (interp=0x804f008,
constt=0x812c148, self=0x80c78c0, cursor=0xb6ce9978) at src/packfile.c:3572
<SNIP>
And here my limited c-fu petered out.
--
Will "Coke" Coleda
