gc: use single allocation for prot_array.

* gc.c (prot_array): Add self pointer; arr member
becomes flexible array.
(prot_array_mark): We now check the handle itself for
null, because the whole thing is freed.
(prot_array_free): Function removed.
(prot_array_ops): Wire cobj_destroy_free_op in place
of prot_array_free. This fixes a memory leak because
prot_array_free was not freeing the handle, only
the array.
(gc_prot_array_alloc): Fix to allocate everything
in one swoop and store the self-pointer in the
named member rather than arr[-1]. The self argument
is not required; we drop it. The size argument cannot
be anywhere near INT_PTR_MAX, because such an array
wouldn't fit into virtual memory, so it is always
safe to add a small value to the size.
(prot_array_free): Obtain the self-pointer, and
free the handle, replacing it with a null pointer.

* gc.h (gc_prot_array_alloc): Declaration updated.

* lib.c (ssort_vec): Don't pass self to gc_prot_array_alloc.

* lib.h (container): New macro.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib.c b/lib.c
index bea09ea3..2e9de482 100644
--- a/lib.c
+++ b/lib.c
@@ -10922,7 +10922,7 @@ static void mergesort(val vec, val lessfun, val keyfun, cnum from, cnum to,
 static void ssort_vec(val vec, val lessfun, val keyfun, val self)
 {
   cnum len = c_fixnum(length(vec), self);
-  val *aux = gc_prot_array_alloc(len, self);
+  val *aux = gc_prot_array_alloc(len);
   mergesort(vec, lessfun, keyfun, 0, len, aux);
   gc_prot_array_free(aux);
 }