Add rb_gc_mark_and_move and implement on iseq

This commit adds rb_gc_mark_and_move which takes a pointer to an object
and marks it during marking phase and updates references during compaction.
This allows for marking and reference updating to be combined into a
single function, which reduces code duplication and prevents bugs if
marking and reference updating goes out of sync.

This commit also implements rb_gc_mark_and_move on iseq as an example.

1 files changed, 8 insertions, 0 deletions

diff --git a/internal/gc.h b/internal/gc.h
index c9123b3c7f..0c6fb2bcaf 100644
--- a/internal/gc.h
+++ b/internal/gc.h
@@ -113,6 +113,14 @@ size_t rb_gc_obj_slot_size(VALUE obj);
 bool rb_gc_size_allocatable_p(size_t size);
 int rb_objspace_garbage_object_p(VALUE obj);
 
+void rb_gc_mark_and_move(VALUE *ptr);
+
+#define rb_gc_mark_and_move_ptr(ptr) do { \
+    VALUE _obj = (VALUE)*(ptr); \
+    rb_gc_mark_and_move(&_obj); \
+    if (_obj != (VALUE)*(ptr)) *(ptr) = (void *)_obj; \
+} while (0)
+
 RUBY_SYMBOL_EXPORT_BEGIN
 /* gc.c (export) */
 const char *rb_objspace_data_type_name(VALUE obj);