Implements `Module::nesting' (15.2.2.3.2); ref #600, #3200

6 files changed, 53 insertions, 4 deletions

diff --git a/include/mruby/irep.h b/include/mruby/irep.h
index 35ae2bbaa..1e9f49fff 100644
--- a/include/mruby/irep.h
+++ b/include/mruby/irep.h
@@ -45,6 +45,8 @@ typedef struct mrb_irep {
   struct mrb_irep_debug_info* debug_info;
 
   size_t ilen, plen, slen, rlen, refcnt;
+
+  struct RProc *outer;      /* Refers outer scope */
 } mrb_irep;
 
 #define MRB_ISEQ_NO_FREE 1
diff --git a/include/mruby/proc.h b/include/mruby/proc.h
index 9c2666289..244b2c361 100644
--- a/include/mruby/proc.h
+++ b/include/mruby/proc.h
@@ -57,6 +57,8 @@ struct RProc {
 #define MRB_PROC_STRICT_P(p) (((p)->flags & MRB_PROC_STRICT) != 0)
 #define MRB_PROC_ORPHAN 512
 #define MRB_PROC_ORPHAN_P(p) (((p)->flags & MRB_PROC_ORPHAN) != 0)
+#define MRB_PROC_CLASS  1024
+#define MRB_PROC_CLASS_P(p) (((p)->flags & MRB_PROC_CLASS) != 0)
 
 #define mrb_proc_ptr(v)    ((struct RProc*)(mrb_ptr(v)))
 
diff --git a/src/class.c b/src/class.c
index 57f64dcc5..54754092e 100644
--- a/src/class.c
+++ b/src/class.c
@@ -2314,6 +2314,8 @@ mrb_mod_module_function(mrb_state *mrb, mrb_value mod)
 mrb_value mrb_obj_id_m(mrb_state *mrb, mrb_value self);
 /* implementation of instance_eval */
 mrb_value mrb_obj_instance_eval(mrb_state*, mrb_value);
+/* implementation of Module.nesting */
+mrb_value mrb_mod_s_nesting(mrb_state*, mrb_value);
 
 void
 mrb_init_class(mrb_state *mrb)
@@ -2407,6 +2409,7 @@ mrb_init_class(mrb_state *mrb)
   mrb_define_method(mrb, mod, "class_variables",         mrb_mod_class_variables,  MRB_ARGS_NONE()); /* 15.2.2.4.19 */
   mrb_define_method(mrb, mod, "===",                     mrb_mod_eqq,              MRB_ARGS_REQ(1));
   mrb_define_class_method(mrb, mod, "constants",         mrb_mod_s_constants,      MRB_ARGS_ANY());  /* 15.2.2.3.1 */
+  mrb_define_class_method(mrb, mod, "nesting",           mrb_mod_s_nesting,        MRB_ARGS_REQ(0)); /* 15.2.2.3.2 */
 
   mrb_undef_method(mrb, cls, "append_features");
   mrb_undef_method(mrb, cls, "extend_object");
diff --git a/src/gc.c b/src/gc.c
index 8cc8feb08..cd885f7e8 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -647,6 +647,9 @@ gc_mark_children(mrb_state *mrb, mrb_gc *gc, struct RBasic *obj)
 
       mrb_gc_mark(mrb, (struct RBasic*)p->env);
       mrb_gc_mark(mrb, (struct RBasic*)p->target_class);
+      if (!MRB_PROC_CFUNC_P(p)) {
+        mrb_gc_mark(mrb, (struct RBasic*)p->body.irep->outer);
+      }
     }
     break;
 
diff --git a/src/vm.c b/src/vm.c
index 45f9bf967..152a28651 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -778,6 +778,25 @@ mrb_yield_cont(mrb_state *mrb, mrb_value b, mrb_value self, mrb_int argc, const
   return mrb_exec_irep(mrb, self, p);
 }
 
+mrb_value
+mrb_mod_s_nesting(mrb_state *mrb, mrb_value mod)
+{
+  struct RProc *proc;
+  mrb_value ary;
+
+  mrb_get_args(mrb, "");
+  ary = mrb_ary_new(mrb);
+  proc = mrb->c->ci[-1].proc;   /* callee proc */
+  while (proc) {
+    mrb_assert(!MRB_PROC_CFUNC_P(proc));
+    if (MRB_PROC_CLASS_P(proc) && proc->target_class) {
+      mrb_ary_push(mrb, ary, mrb_obj_value(proc->target_class));
+    }
+    proc = proc->body.irep->outer;
+  }
+  return ary;
+}
+
 static struct RBreak*
 break_new(mrb_state *mrb, struct RProc *p, mrb_value val)
 {
@@ -2701,16 +2720,20 @@ RETRY_TRY_BLOCK:
     CASE(OP_LAMBDA) {
       /* A b c  R(A) := lambda(SEQ[b],c) (b:c = 14:2) */
       struct RProc *p;
+      int a = GETARG_A(i);
+      int b = GETARG_b(i);
       int c = GETARG_c(i);
+      mrb_irep *nirep = irep->reps[b];
 
+      nirep->outer = mrb->c->ci->proc;
       if (c & OP_L_CAPTURE) {
-        p = mrb_closure_new(mrb, irep->reps[GETARG_b(i)]);
+        p = mrb_closure_new(mrb, nirep);
       }
       else {
-        p = mrb_proc_new(mrb, irep->reps[GETARG_b(i)]);
+        p = mrb_proc_new(mrb, nirep);
       }
       if (c & OP_L_STRICT) p->flags |= MRB_PROC_STRICT;
-      regs[GETARG_A(i)] = mrb_obj_value(p);
+      regs[a] = mrb_obj_value(p);
       mrb_gc_arena_restore(mrb, ai);
       NEXT;
     }
@@ -2765,13 +2788,17 @@ RETRY_TRY_BLOCK:
     CASE(OP_EXEC) {
       /* A Bx   R(A) := blockexec(R(A),SEQ[Bx]) */
       int a = GETARG_A(i);
+      int bx = GETARG_Bx(i);
       mrb_callinfo *ci;
       mrb_value recv = regs[a];
       struct RProc *p;
+      mrb_irep *nirep = irep->reps[bx];
 
+      nirep->outer = mrb->c->ci->proc;
       /* prepare closure */
-      p = mrb_closure_new(mrb, irep->reps[GETARG_Bx(i)]);
+      p = mrb_closure_new(mrb, nirep);
       p->c = NULL;
+      p->flags |= MRB_PROC_CLASS;
 
       /* prepare stack */
       ci = cipush(mrb);
diff --git a/test/t/module.rb b/test/t/module.rb
index e32cac5f1..107bea875 100644
--- a/test/t/module.rb
+++ b/test/t/module.rb
@@ -29,6 +29,18 @@ end
 
 # TODO not implemented ATM assert('Module.nesting', '15.2.2.3.2') do
 
+assert('Module.nesting', '15.2.2.2.2') do
+  module Test4ModuleNesting
+    module Test4ModuleNesting2
+      assert_equal [Test4ModuleNesting2, Test4ModuleNesting],
+                   Module.nesting
+    end
+  end
+  module Test4ModuleNesting::Test4ModuleNesting2
+    assert_equal [Test4ModuleNesting::Test4ModuleNesting2], Module.nesting
+  end
+end
+
 assert('Module#ancestors', '15.2.2.4.9') do
   class Test4ModuleAncestors
   end