Make Object.freeze fast

test/mjsunit/object-freeze.js

Index: test/mjsunit/object-freeze.js
diff --git a/test/mjsunit/object-freeze.js b/test/mjsunit/object-freeze.js
index c3a9278bbd9c4629489f143e52cedba78684ddb4..6a177a4441fcc2ecb34a3dc16e07fc101ce267c2 100644
--- a/test/mjsunit/object-freeze.js
+++ b/test/mjsunit/object-freeze.js
@@ -28,6 +28,7 @@
 // Tests the Object.freeze and Object.isFrozen methods - ES 15.2.3.9 and
 // ES 15.2.3.12
 
+// Flags: --allow-natives-syntax
 
 // Test that we throw an error if an object is not passed as argument.
 var non_objects = new Array(undefined, null, 1, -1, 0, 42.43);
@@ -191,3 +192,64 @@ assertFalse(Object.isFrozen(obj5));
 // Make sure that Object.freeze returns the frozen object.
 var obj6 = {}
 assertTrue(obj6 === Object.freeze(obj6))
+
+// Test that the enumerable attribute is unperturbed by freezing.
+obj = { x: 42, y: 'foo' };
+Object.defineProperty(obj, 'y', {enumerable: false});
+Object.freeze(obj);
+desc = Object.getOwnPropertyDescriptor(obj, 'x');
+assertTrue(desc.enumerable);
+desc = Object.getOwnPropertyDescriptor(obj, 'y');
+assertFalse(desc.enumerable);
+
+// Fast properties should remain fast
+obj = { x: 42, y: 'foo' };
+assertTrue(%HasFastProperties(obj));
+Object.freeze(obj);
+assertTrue(%HasFastProperties(obj));
+
+// Frozen objects should share maps where possible
+obj = { prop1: 1, prop2: 2 };
+obj2 = { prop1: 3, prop2: 4 };
+assertTrue(%HaveSameMap(obj, obj2));
+Object.freeze(obj);
+Object.freeze(obj2);
+assertTrue(%HaveSameMap(obj, obj2));
+
+// Frozen objects should share maps even when they have elements
+obj = { prop1: 1, prop2: 2, 75: 'foo' };
+obj2 = { prop1: 3, prop2: 4, 150: 'bar' };
+assertTrue(%HaveSameMap(obj, obj2));
+Object.freeze(obj);
+Object.freeze(obj2);
+assertTrue(%HaveSameMap(obj, obj2));
+
+// Setting elements after freezing should not be allowed
+obj = { prop: 'thing' };
+Object.freeze(obj);
+obj[0] = 'hello';
+assertFalse(obj.hasOwnProperty(0));
+
+// Freezing an object in dictionary mode should work
+obj = { };
+for (var i = 0; i < 100; ++i) {
+  obj['x' + i] = i;
+}
+assertFalse(%HasFastProperties(obj));
+Object.freeze(obj);
+assertFalse(%HasFastProperties(obj));
+assertTrue(Object.isFrozen(obj));
+assertFalse(Object.isExtensible(obj));
+for (var i = 0; i < 100; ++i) {
+  desc = Object.getOwnPropertyDescriptor(obj, 'x' + i);
+  assertFalse(desc.writable);
+  assertFalse(desc.configurable);
+}
+
+// Freezing arguments should work
+var func = function(arg) {
+  Object.freeze(arguments);
+  assertTrue(Object.isFrozen(arguments));
+};
+func('hello', 'world');
+func('goodbye', 'world');