Move `mrb_mod_s_nesting()` to `mruby-metaprog` gem from the core

1 files changed, 24 insertions, 2 deletions

diff --git a/mrbgems/mruby-metaprog/src/metaprog.c b/mrbgems/mruby-metaprog/src/metaprog.c
index 0aafb4c34..38f75d460 100644
--- a/mrbgems/mruby-metaprog/src/metaprog.c
+++ b/mrbgems/mruby-metaprog/src/metaprog.c
@@ -657,8 +657,30 @@ mrb_mod_s_constants(mrb_state *mrb, mrb_value mod)
   return mrb_nil_value();       /* not reached */
 }
 
-/* implementation of Module.nesting */
-mrb_value mrb_mod_s_nesting(mrb_state*, mrb_value);
+mrb_value
+mrb_mod_s_nesting(mrb_state *mrb, mrb_value mod)
+{
+  struct RProc *proc;
+  mrb_value ary;
+  struct RClass *c = NULL;
+
+  mrb_get_args(mrb, "");
+  ary = mrb_ary_new(mrb);
+  proc = mrb->c->ci[-1].proc;   /* callee proc */
+  mrb_assert(!MRB_PROC_CFUNC_P(proc));
+  while (proc) {
+    if (MRB_PROC_SCOPE_P(proc)) {
+      struct RClass *c2 = MRB_PROC_TARGET_CLASS(proc);
+
+      if (c2 != c) {
+        c = c2;
+        mrb_ary_push(mrb, ary, mrb_obj_value(c));
+      }
+    }
+    proc = proc->upper;
+  }
+  return ary;
+}
 
 void
 mrb_mruby_metaprog_gem_init(mrb_state* mrb)