Implement Object#freeze

include/mruby/class.h

@@ -52,6 +52,7 @@ mrb_class(mrb_state *mrb, mrb_value v)
 }
 
 // TODO: figure out where to put user flags
+#define MRB_FLAG_IS_FROZEN (1 << 18)
 #define MRB_FLAG_IS_PREPENDED (1 << 19)
 #define MRB_FLAG_IS_ORIGIN (1 << 20)
 #define MRB_CLASS_ORIGIN(c) do {\

include/mruby/object.h

@@ -22,6 +22,10 @@ struct RBasic {
 };
 #define mrb_basic_ptr(v) ((struct RBasic*)(mrb_ptr(v)))
 
+#define RBASIC_FROZEN_P(o) ((o)->flags & MRB_FLAG_IS_FROZEN)
+#define RBASIC_SET_FROZEN_FLAG(o) ((o)->flags |= MRB_FLAG_IS_FROZEN)
+#define RBASIC_UNSET_FROZEN_FLAG(o) ((o)->flags &= ~MRB_FLAG_IS_FROZEN)
+
 struct RObject {
   MRB_OBJECT_HEADER;
   struct iv_tbl *iv;

include/mruby/string.h

@@ -62,10 +62,6 @@ struct RString {
 #define RSTR_SET_NOFREE_FLAG(s) ((s)->flags |= MRB_STR_NOFREE)
 #define RSTR_UNSET_NOFREE_FLAG(s) ((s)->flags &= ~MRB_STR_NOFREE)
 
-#define RSTR_FROZEN_P(s) ((s)->flags & MRB_STR_FROZEN)
-#define RSTR_SET_FROZEN_FLAG(s) ((s)->flags |= MRB_STR_FROZEN)
-#define RSTR_UNSET_FROZEN_FLAG(s) ((s)->flags &= ~MRB_STR_FROZEN)
-
 /*
  * Returns a pointer from a Ruby string
  */
@@ -80,7 +76,6 @@ MRB_API mrb_int mrb_str_strlen(mrb_state*, struct RString*);
 
 #define MRB_STR_SHARED    1
 #define MRB_STR_NOFREE    2
-#define MRB_STR_FROZEN    4
 #define MRB_STR_NO_UTF    8
 #define MRB_STR_EMBED    16
 #define MRB_STR_EMBED_LEN_MASK 0x3e0

src/array.c

@@ -108,6 +108,10 @@ ary_fill_with_nil(mrb_value *ptr, mrb_int size)
 static void
 ary_modify(mrb_state *mrb, struct RArray *a)
 {
+  if (RBASIC_FROZEN_P(a)) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "can't modify frozen array");
+  }
+
   if (ARY_SHARED_P(a)) {
     mrb_shared_array *shared = a->aux.shared;
 

src/hash.c

@@ -98,9 +98,9 @@ static void mrb_hash_modify(mrb_state *mrb, mrb_value hash);
 static inline mrb_value
 mrb_hash_ht_key(mrb_state *mrb, mrb_value key)
 {
-  if (mrb_string_p(key) && !RSTR_FROZEN_P(mrb_str_ptr(key))) {
+  if (mrb_string_p(key) && !RBASIC_FROZEN_P(mrb_str_ptr(key))) {
     key = mrb_str_dup(mrb, key);
-    RSTR_SET_FROZEN_FLAG(mrb_str_ptr(key));
+    RBASIC_SET_FROZEN_FLAG(mrb_str_ptr(key));
   }
   return key;
 }
@@ -278,6 +278,9 @@ mrb_hash_tbl(mrb_state *mrb, mrb_value hash)
 static void
 mrb_hash_modify(mrb_state *mrb, mrb_value hash)
 {
+  if (RBASIC_FROZEN_P(mrb_hash_ptr(hash))) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "can't modify frozen hash");
+  }
   mrb_hash_tbl(mrb, hash);
 }
 

src/kernel.c

@@ -450,6 +450,15 @@ mrb_obj_extend_m(mrb_state *mrb, mrb_value self)
   return mrb_obj_extend(mrb, argc, argv, self);
 }
 
+static mrb_value
+mrb_obj_freeze(mrb_state *mrb, mrb_value self)
+{
+  struct RBasic *b = mrb_basic_ptr(self);
+
+  RBASIC_SET_FROZEN_FLAG(b);
+  return self;
+}
+
 /* 15.3.1.3.15 */
 /*
  *  call-seq:
@@ -1124,6 +1133,7 @@ mrb_init_kernel(mrb_state *mrb)
   mrb_define_method(mrb, krn, "eql?",                       mrb_obj_equal_m,                 MRB_ARGS_REQ(1));    /* 15.3.1.3.10 */
   mrb_define_method(mrb, krn, "equal?",                     mrb_obj_equal_m,                 MRB_ARGS_REQ(1));    /* 15.3.1.3.11 */
   mrb_define_method(mrb, krn, "extend",                     mrb_obj_extend_m,                MRB_ARGS_ANY());     /* 15.3.1.3.13 */
+  mrb_define_method(mrb, krn, "freeze",                     mrb_obj_freeze,                  MRB_ARGS_NONE());
   mrb_define_method(mrb, krn, "global_variables",           mrb_f_global_variables,          MRB_ARGS_NONE());    /* 15.3.1.3.14 */
   mrb_define_method(mrb, krn, "hash",                       mrb_obj_hash,                    MRB_ARGS_NONE());    /* 15.3.1.3.15 */
   mrb_define_method(mrb, krn, "initialize_copy",            mrb_obj_init_copy,               MRB_ARGS_REQ(1));    /* 15.3.1.3.16 */

src/string.c

@@ -501,7 +501,7 @@ str_index(mrb_state *mrb, mrb_value str, mrb_value sub, mrb_int offset)
 static void
 check_frozen(mrb_state *mrb, struct RString *s)
 {
-  if (RSTR_FROZEN_P(s)) {
+  if (RBASIC_FROZEN_P(s)) {
     mrb_raise(mrb, E_RUNTIME_ERROR, "can't modify frozen string");
   }
 }
@@ -700,15 +700,6 @@ mrb_str_modify(mrb_state *mrb, struct RString *s)
   }
 }
 
-static mrb_value
-mrb_str_freeze(mrb_state *mrb, mrb_value str)
-{
-  struct RString *s = mrb_str_ptr(str);
-
-  RSTR_SET_FROZEN_FLAG(s);
-  return str;
-}
-
 MRB_API mrb_value
 mrb_str_resize(mrb_state *mrb, mrb_value str, mrb_int len)
 {
@@ -2217,7 +2208,7 @@ mrb_string_value_cstr(mrb_state *mrb, mrb_value *ptr)
   char *p = RSTR_PTR(ps);
 
   if (!p || p[len] != '\0') {
-    if (RSTR_FROZEN_P(ps)) {
+    if (RBASIC_FROZEN_P(ps)) {
       *ptr = str = mrb_str_dup(mrb, str);
       ps = mrb_str_ptr(str);
     }
@@ -2746,8 +2737,6 @@ mrb_init_string(mrb_state *mrb)
   mrb_define_method(mrb, s, "upcase!",         mrb_str_upcase_bang,     MRB_ARGS_NONE()); /* 15.2.10.5.43 */
   mrb_define_method(mrb, s, "inspect",         mrb_str_inspect,         MRB_ARGS_NONE()); /* 15.2.10.5.46(x) */
   mrb_define_method(mrb, s, "bytes",           mrb_str_bytes,           MRB_ARGS_NONE());
-
-  mrb_define_method(mrb, s, "freeze",          mrb_str_freeze,          MRB_ARGS_NONE());
 }
 
 /*

test/t/array.rb

@@ -373,3 +373,10 @@ assert("Array#rindex") do
   $a = [2, 3, 4, 5, 6, 7, 8, 9, 10, Sneaky.new]
   assert_equal 0, $a.rindex(1)
 end
+
+assert('Array#freeze') do
+  a = [].freeze
+  assert_raise(RuntimeError) do
+    a[0] = 1
+  end
+end

test/t/hash.rb

@@ -366,3 +366,10 @@ assert('Hash#rehash') do
   h.rehash
   assert_equal("b", h[[:b]])
 end
+
+assert('Hash#freeze') do
+  h = {}.freeze
+  assert_raise(RuntimeError) do
+    h[:a] = 'b'
+  end
+end

test/t/kernel.rb

@@ -257,6 +257,11 @@ assert('Kernel#extend works on toplevel', '15.3.1.3.13') do
   assert_true respond_to?(:test_method)
 end
 
+assert('Kernel#freeze') do
+  obj = Object.new
+  assert_equal obj, obj.freeze
+end
+
 assert('Kernel#global_variables', '15.3.1.3.14') do
   assert_equal Array, global_variables.class
 end