http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55792
--- Comment #11 from Diego Novillo <dnovillo at gcc dot gnu.org> 2013-01-07
17:54:14 UTC ---
(In reply to comment #9)
> Eh. Diego, how does GTY((user)) work here? It smells like a bug in vec.h
> to me.
>
> /* Garbage collection support for vec<T, A, vl_embed>. */
>
> template<typename T>
> void
> gt_ggc_mx (vec<T, va_gc> *v)
> {
> extern void gt_ggc_mx (T &);
> for (unsigned i = 0; i < v->length (); i++)
> gt_ggc_mx ((*v)[i]);
> }
>
> doesn't it need to mark the vec itself? Maybe automatic registration of
> roots (this is a GC root) does not work with GTY((user))?
No. The root is/should be marked by the code calling gt_ggc_mx. gengtype will
generate code like:
if (ggc_test_and_set_mark (x))
{
gt_ggc_mx (x);
}
ggc_test_and_set_mark() is the one that marks the root. Has gengtype generated
a function for this global? It should be something like this
void
gt_ggc_mx_vec_<mangled_type_name> (void *x_p)
{
vec<type_name,va_gc> * const x = (vec<type_name,va_gc> *)x_p;
if (ggc_test_and_set_mark (x))
{
gt_ggc_mx (x);
}
}
