Copying GC support for EXIVAR

Instance variables held in gen_ivtbl are marked with rb_gc_mark.  It
prevents the referenced objects from moving, which is bad for copying
garbage collectors.

This commit allows those instance variables to be updated during
gc_update_object_references.

3 files changed, 10 insertions, 6 deletions

diff --git a/gc.c b/gc.c
index 82590b9234..269d46daef 100644
--- a/gc.c
+++ b/gc.c
@@ -7232,7 +7232,7 @@ gc_mark_children(rb_objspace_t *objspace, VALUE obj)
     gc_mark_set_parent(objspace, obj);
 
     if (FL_TEST(obj, FL_EXIVAR)) {
-        rb_mark_generic_ivar(obj);
+        rb_mark_and_update_generic_ivar(obj);
     }
 
     switch (BUILTIN_TYPE(obj)) {
@@ -10560,6 +10560,10 @@ gc_update_object_references(rb_objspace_t *objspace, VALUE obj)
 
     gc_report(4, objspace, "update-refs: %p ->\n", (void *)obj);
 
+    if (FL_TEST(obj, FL_EXIVAR)) {
+        rb_mark_and_update_generic_ivar(obj);
+    }
+
     switch (BUILTIN_TYPE(obj)) {
       case T_CLASS:
       case T_MODULE:
diff --git a/internal/variable.h b/internal/variable.h
index 3933279633..88fa28e1ba 100644
--- a/internal/variable.h
+++ b/internal/variable.h
@@ -42,7 +42,7 @@ int rb_obj_evacuate_ivs_to_hash_table(ID key, VALUE val, st_data_t arg);
 
 RUBY_SYMBOL_EXPORT_BEGIN
 /* variable.c (export) */
-void rb_mark_generic_ivar(VALUE);
+void rb_mark_and_update_generic_ivar(VALUE);
 void rb_mv_generic_ivar(VALUE src, VALUE dst);
 VALUE rb_const_missing(VALUE klass, VALUE name);
 int rb_class_ivar_set(VALUE klass, ID vid, VALUE value);
diff --git a/variable.c b/variable.c
index f1d89ab615..def22449a5 100644
--- a/variable.c
+++ b/variable.c
@@ -1020,22 +1020,22 @@ generic_ivar_update(st_data_t *k, st_data_t *v, st_data_t u, int existing)
 }
 
 static void
-gen_ivtbl_mark(const struct gen_ivtbl *ivtbl)
+gen_ivtbl_mark_and_update(struct gen_ivtbl *ivtbl)
 {
     uint32_t i;
 
     for (i = 0; i < ivtbl->numiv; i++) {
-        rb_gc_mark(ivtbl->ivptr[i]);
+        rb_gc_mark_and_move(&ivtbl->ivptr[i]);
     }
 }
 
 void
-rb_mark_generic_ivar(VALUE obj)
+rb_mark_and_update_generic_ivar(VALUE obj)
 {
     struct gen_ivtbl *ivtbl;
 
     if (rb_gen_ivtbl_get(obj, 0, &ivtbl)) {
-        gen_ivtbl_mark(ivtbl);
+        gen_ivtbl_mark_and_update(ivtbl);
     }
 }