Extract frozen checking to function

src/array.c

@@ -120,9 +120,7 @@ ary_fill_with_nil(mrb_value *ptr, mrb_int size)
 static void
 ary_modify_check(mrb_state *mrb, struct RArray *a)
 {
-  if (MRB_FROZEN_P(a)) {
-    mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen array");
-  }
+  mrb_check_frozen(mrb, a);
 }
 
 static void

src/class.c

@@ -441,12 +441,7 @@ mrb_define_method_raw(mrb_state *mrb, struct RClass *c, mrb_sym mid, mrb_method_
   MRB_CLASS_ORIGIN(c);
   h = c->mt;
 
-  if (MRB_FROZEN_P(c)) {
-    if (c->tt == MRB_TT_MODULE)
-      mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen module");
-    else
-      mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen class");
-  }
+  mrb_check_frozen(mrb, c);
   if (!h) h = c->mt = kh_init(mt, mrb);
   k = kh_put(mt, mrb, h, mid);
   kh_value(h, k) = m;

src/error.c

@@ -484,6 +484,13 @@ mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_value args, char const* fmt,
   mrb_exc_raise(mrb, exc);
 }
 
+MRB_API mrb_noreturn void
+mrb_frozen_error(mrb_state *mrb, void *frozen_obj)
+{
+  mrb_raisef(mrb, E_FROZEN_ERROR, "can't modify frozen %S",
+             mrb_obj_value(mrb_class(mrb, mrb_obj_value(frozen_obj))));
+}
+
 void
 mrb_init_exception(mrb_state *mrb)
 {

src/hash.c

@@ -746,10 +746,7 @@ mrb_hash_set(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_value val)
 static void
 mrb_hash_modify(mrb_state *mrb, mrb_value hash)
 {
-  if (MRB_FROZEN_P(mrb_hash_ptr(hash))) {
-    mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen hash");
-  }
-
+  mrb_check_frozen(mrb, mrb_hash_ptr(hash));
   if (!RHASH_TBL(hash)) {
     RHASH_TBL(hash) = ht_new(mrb);
   }

src/string.c

@@ -493,20 +493,12 @@ str_index_str(mrb_state *mrb, mrb_value str, mrb_value str2, mrb_int offset)
   return mrb_str_index(mrb, str, ptr, len, offset);
 }
 
-static void
-check_frozen(mrb_state *mrb, struct RString *s)
-{
-  if (MRB_FROZEN_P(s)) {
-    mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen string");
-  }
-}
-
 static mrb_value
 str_replace(mrb_state *mrb, struct RString *s1, struct RString *s2)
 {
   mrb_int len;
 
-  check_frozen(mrb, s1);
+  mrb_check_frozen(mrb, s1);
   if (s1 == s2) return mrb_obj_value(s1);
   s1->flags &= ~MRB_STR_NO_UTF;
   s1->flags |= s2->flags&MRB_STR_NO_UTF;
@@ -646,7 +638,7 @@ mrb_locale_from_utf8(const char *utf8, int len)
 MRB_API void
 mrb_str_modify(mrb_state *mrb, struct RString *s)
 {
-  check_frozen(mrb, s);
+  mrb_check_frozen(mrb, s);
   s->flags &= ~MRB_STR_NO_UTF;
   if (RSTR_SHARED_P(s)) {
     mrb_shared_string *shared = s->as.heap.aux.shared;

src/variable.c

@@ -346,9 +346,7 @@ mrb_obj_iv_set(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
 {
   iv_tbl *t;
 
-  if (MRB_FROZEN_P(obj)) {
-    mrb_raisef(mrb, E_FROZEN_ERROR, "can't modify frozen %S", mrb_obj_value(obj));
-  }
+  mrb_check_frozen(mrb, obj);
   assign_class_name(mrb, obj, sym, v);
   if (!obj->iv) {
     obj->iv = iv_new(mrb);