# New Ticket Created by Jerry Gay
# Please include the string: [perl #50878]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=50878 >
'cotto' on #parrot came to me with a problem today. he is unable to
call VTABLE_is_equal(...) inside a .pmc file. i'll use
src/pmc/exporter.pmc as an example pmc file, because i know its
internals. here's a patch:
Index: src/pmc/exporter.pmc
===================================================================
--- src/pmc/exporter.pmc (revision 25720)
+++ src/pmc/exporter.pmc (working copy)
@@ -100,6 +100,17 @@
*/
+static void test(PARROT_INTERP) {
+ PMC *p1 = pmc_new(interp, enum_class_String);
+ PMC *p2 = pmc_new(interp, enum_class_String);
+ INTVAL cmp;
+ VTABLE_set_string_native(interp, p1, const_string(interp, "test"));
+ VTABLE_set_string_native(interp, p2, const_string(interp, "test"));
+
+ cmp = VTABLE_is_equal(interp, p1, p2);
+ printf("<<<%d>>>\n", cmp);
+}
+
pmclass Exporter
need_ext {
@@ -117,6 +128,7 @@
void init() {
Parrot_Exporter *exp = NULL;
+ test(INTERP);
/* Set up the object. */
exp = mem_allocate_zeroed_typed(Parrot_Exporter);
exp->ns_src = PMCNULL;
compiling with this patch produces an error like:
exporter.obj : error LNK2019: unresolved external symbol
_VTABLE_is_equal referenced in function _test
err, wha? it's in docs/pdds/pdd17_pmc.pod. it should be there. why on
earth isn't it callable?
i went digging in include/parrot/vtable.h, tools/build/vtable_h.pl,
src/vtable.tbl, lib/Parrot/Vtable.pm. i can't figure out what's going
on. i can see that there's no VTABLE_ macro for is_equal (or cmp, for
that matter). i just can't put my finger on *why*. i wondered if it
was just the missing VTABLE_ accessor macros, so i unrolled the macro.
+ cmp = (p1)->vtable->is_equal(interp, p1, p2);
didn't work:
.\src\pmc\exporter.pmc(110) : error C2039: 'is_equal' : is not a
member of '_vtable'
i was able to work around the problem, looking at how 'eq' is
implemented in src/ops/cmp.ops gave me an idea. if i replace the line
+ cmp = VTABLE_is_equal(interp, p1, p2);
with
+ cmp = mmd_dispatch_i_pp(interp, p1, p2, MMD_EQ);
then it works. so, mmd dispatch is working. the functions are there.
what am i missing? i'm guessing it's something in the perl that
generates the c, but i have to step away for a while. i'd be happy if
somebody else put their eyes on it, too. chromatic? anyone?
~jerry
