Raise `ArgumentError` by `aspec` check; ref #4688

This is partial `aspec` check that only checks `MRB_ARGS_NONE()`.

3 files changed, 13 insertions, 0 deletions

diff --git a/include/mruby/proc.h b/include/mruby/proc.h
index e58684fa1..f7f4d336a 100644
--- a/include/mruby/proc.h
+++ b/include/mruby/proc.h
@@ -98,9 +98,12 @@ MRB_API mrb_value mrb_proc_cfunc_env_get(mrb_state *mrb, mrb_int idx);
 #define mrb_cfunc_env_get(mrb, idx) mrb_proc_cfunc_env_get(mrb, idx)
 
 #define MRB_METHOD_FUNC_FL 1
+#define MRB_METHOD_NOARG_FL 2
 #ifdef MRB_METHOD_TABLE_INLINE
 
 #define MRB_METHOD_FUNC_P(m) (((uintptr_t)(m))&MRB_METHOD_FUNC_FL)
+#define MRB_METHOD_NOARG_P(m) (((uintptr_t)(m))&MRB_METHOD_NOARG_FL)
+#define MRB_METHOD_NOARG_SET(m) ((m)=(mrb_method_t)(((uintptr_t)(m))|MRB_METHOD_NOARG_FL))
 #define MRB_METHOD_FUNC(m) ((mrb_func_t)((uintptr_t)(m)>>2))
 #define MRB_METHOD_FROM_FUNC(m,fn) ((m)=(mrb_method_t)((((uintptr_t)(fn))<<2)|MRB_METHOD_FUNC_FL))
 #define MRB_METHOD_FROM_PROC(m,pr) ((m)=(mrb_method_t)(pr))
@@ -111,7 +114,9 @@ MRB_API mrb_value mrb_proc_cfunc_env_get(mrb_state *mrb, mrb_int idx);
 #else
 
 #define MRB_METHOD_FUNC_P(m) ((m).flags&MRB_METHOD_FUNC_FL)
+#define MRB_METHOD_NOARG_P(m) ((m).flags&MRB_METHOD_NOARG_FL)
 #define MRB_METHOD_FUNC(m) ((m).func)
+#define MRB_METHOD_NOARG_SET(m) do{(m).flags|=MRB_METHOD_NOARG_FL;}while(0)
 #define MRB_METHOD_FROM_FUNC(m,fn) do{(m).flags=MRB_METHOD_FUNC_FL;(m).func=(fn);}while(0)
 #define MRB_METHOD_FROM_PROC(m,pr) do{(m).flags=0;(m).proc=(pr);}while(0)
 #define MRB_METHOD_PROC_P(m) (!MRB_METHOD_FUNC_P(m))
diff --git a/src/class.c b/src/class.c
index ac0bb8ede..d037a8abb 100644
--- a/src/class.c
+++ b/src/class.c
@@ -470,6 +470,9 @@ mrb_define_method_id(mrb_state *mrb, struct RClass *c, mrb_sym mid, mrb_func_t f
   int ai = mrb_gc_arena_save(mrb);
 
   MRB_METHOD_FROM_FUNC(m, func);
+  if (aspec == MRB_ARGS_NONE()) {
+    MRB_METHOD_NOARG_SET(m);
+  }
   mrb_define_method_raw(mrb, c, mid, m);
   mrb_gc_arena_restore(mrb, ai);
 }
diff --git a/src/vm.c b/src/vm.c
index 8d233f291..449ea7b13 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1435,6 +1435,11 @@ RETRY_TRY_BLOCK:
           ci->proc = p;
           recv = p->body.func(mrb, recv);
         }
+        else if (MRB_METHOD_NOARG_P(m) &&
+                 (argc > 0 || (argc == -1 && RARRAY_LEN(regs[1]) != 0))) {
+          argnum_error(mrb, 0);
+          goto L_RAISE;
+        }
         else {
           recv = MRB_METHOD_FUNC(m)(mrb, recv);
         }