Avoid allocating Lisp_Save_Value for arrays

* src/alloc.c (mark_maybe_objects): New function.
* src/eval.c (default_toplevel_binding)
(backtrace_eval_unrewind, Fbacktrace__locals):
Treat array unwindings like other miscellaneous pdl types.
(record_unwind_protect_array): New function.
(do_one_unbind): Free the array while unwinding.
(mark_specpdl): Mark arrays directly.
* src/lisp.h (SPECPDL_UNWIND_ARRAY): New constant.
(union specbinding): New member unwind_array.
(SAFE_ALLOCA_LISP_EXTRA): Use record_unwind_protect_array
instead of make_save_memory + record_unwind_protect.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/alloc.c b/src/alloc.c
index e5fc6ebeb1a..1d3ec4fbb8a 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -4845,6 +4845,13 @@ mark_maybe_object (Lisp_Object obj)
     }
 }
 
+void
+mark_maybe_objects (Lisp_Object *array, ptrdiff_t nelts)
+{
+  for (Lisp_Object *lim = array + nelts; array < lim; array++)
+    mark_maybe_object (*array);
+}
+
 /* Return true if P might point to Lisp data that can be garbage
    collected, and false otherwise (i.e., false if it is easy to see
    that P cannot point to Lisp data that can be garbage collected).