It has been altogether too long since I wrote XS code. I have some code which
goes through an array and splices out a certain value:
void _drop_node(HV* a, SV* activelist) {
AV* newlist = newAV();
I32 i = 0;
while (i <= av_len((AV*)SvRV(activelist))) {
SV** x = av_fetch((AV*)SvRV(activelist), i, 0);
if (*x && SvRV(*x) && SvRV(*x) != (SV*)a)
av_push(newlist, newSVsv(*x));
i++;
}
SvRV_set(activelist, (SV*)newlist);
}
This works, but it's horrible and it leaks like a sieve. I'd like to fix the
leak, but ideally I'd prefer to replace it with more sensible code. So I tried
this instead:
void _drop_node(HV* a, SV* activelist) {
SV** src;
AV* ary = (AV*)SvRV(activelist);
I32 i = 0;
i=0;
while (i <= AvFILLp(ary)) {
SV** x = AvARRAY(ary) + i;
if (*x && SvRV(*x) && SvRV(*x) == (SV*)a) break;
i++;
}
src = AvARRAY(ary) + i + 1;
Move(src,src - 1, AvFILLp(ary) - i + 1, SV*);
AvFILLp(ary)--;
}
(Last three lines stolen from pp.c:pp_splice.) Unfortunately, this seems to do
the right thing to the array but it messes up existing pointers to things that
used to be in the array - tests are giving strangely wrong answers.
I don't know what to do at this point. Can anyone help? (The module is
Text::KnuthPlass, if anyone's interested, and there's a similarly leaky
function called _insert_before that I'd also like to fix up.)
