Add new type of shared string: `RSTR_FSHARED`.

`RSTR_FSHARED` use frozen strings as shared body instead of
`struct mrb_shared_string`. This reduces allocation from
literal strings.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gc.c b/src/gc.c
index 196fb504c..0f95d25ef 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -698,6 +698,10 @@ gc_mark_children(mrb_state *mrb, mrb_gc *gc, struct RBasic *obj)
     break;
 
   case MRB_TT_STRING:
+    if (RSTR_FSHARED_P(obj) && !RSTR_NOFREE_P(obj)) {
+      struct RString *s = (struct RString*)obj;
+      mrb_gc_mark(mrb, (struct RBasic*)s->as.heap.aux.fshared);
+    }
     break;
 
   case MRB_TT_RANGE: