Remove hidden prototype for builtin functions.

test/mjsunit/undeletable-functions.js

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 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Test that we match JSC in making some functions undeletable.
-// See http://code.google.com/p/chromium/issues/detail?id=1717
-// The functions on these prototypes are not just undeletable.  It is
-// possible to override them with new definitions, then get the old
-// version back by deleting the new definition.
+// Test that we match ECMAScript in making most builtin functions
+// deletable and only specific ones undeletable or read-only.
 
 var array;
 
 array = [
   "toString", "toLocaleString", "join", "pop", "push", "concat", "reverse",
   "shift", "unshift", "slice", "splice", "sort", "filter", "forEach", "some",
   "every", "map", "indexOf", "lastIndexOf", "reduce", "reduceRight"];
-CheckJSCSemantics(Array.prototype, array, "Array prototype");
+CheckEcmaSemantics(Array.prototype, array, "Array prototype");
 
 var old_Array_prototype = Array.prototype;
 var new_Array_prototype = {};
 for (var i = 0; i < 7; i++) {
   Array.prototype = new_Array_prototype;
   assertEquals(old_Array_prototype, Array.prototype);
 }
 
 array = [
   "toString", "toDateString", "toTimeString", "toLocaleString",
   "toLocaleDateString", "toLocaleTimeString", "valueOf", "getTime",
   "getFullYear", "getUTCFullYear", "getMonth", "getUTCMonth", "getDate",
   "getUTCDate", "getDay", "getUTCDay", "getHours", "getUTCHours", "getMinutes",
   "getUTCMinutes", "getSeconds", "getUTCSeconds", "getMilliseconds",
   "getUTCMilliseconds", "getTimezoneOffset", "setTime", "setMilliseconds",
   "setUTCMilliseconds", "setSeconds", "setUTCSeconds", "setMinutes",
   "setUTCMinutes", "setHours", "setUTCHours", "setDate", "setUTCDate",
   "setMonth", "setUTCMonth", "setFullYear", "setUTCFullYear", "toGMTString",
   "toUTCString", "getYear", "setYear", "toISOString", "toJSON"];
-CheckJSCSemantics(Date.prototype, array, "Date prototype");
+CheckEcmaSemantics(Date.prototype, array, "Date prototype");
 
 array = [
   "random", "abs", "acos", "asin", "atan", "ceil", "cos", "exp", "floor", "log",
   "round", "sin", "sqrt", "tan", "atan2", "pow", "max", "min"];
-CheckJSCSemantics(Math, array, "Math1");
+CheckEcmaSemantics(Math, array, "Math1");
 
 CheckEcmaSemantics(Date, ["UTC", "parse", "now"], "Date");
 
 array = [
   "E", "LN10", "LN2", "LOG2E", "LOG10E", "PI", "SQRT1_2", "SQRT2"];
 CheckDontDelete(Math, array, "Math2");
 
 array = [
   "escape", "unescape", "decodeURI", "decodeURIComponent", "encodeURI",
   "encodeURIComponent", "isNaN", "isFinite", "parseInt", "parseFloat", "eval",
@@ skipping 31 matching lines @@
 CheckEcmaSemantics(Function.prototype, ["toString"], "Function prototype");
 CheckEcmaSemantics(Date.prototype, ["constructor"], "Date prototype constructor");
 
 array = [
   "charAt", "charCodeAt", "concat", "indexOf",
   "lastIndexOf", "localeCompare", "match", "replace", "search", "slice",
   "split", "substring", "substr", "toLowerCase", "toLocaleLowerCase",
   "toUpperCase", "toLocaleUpperCase", "link", "anchor", "fontcolor", "fontsize",
   "big", "blink", "bold", "fixed", "italics", "small", "strike", "sub", "sup",
   "toJSON", "toString", "valueOf"];
-CheckJSCSemantics(String.prototype, array, "String prototype");
+CheckEcmaSemantics(String.prototype, array, "String prototype");
 CheckEcmaSemantics(String, ["fromCharCode"], "String");
 
 
 function CheckEcmaSemantics(type, props, name) {
   print(name);
   for (var i = 0; i < props.length; i++) {
     CheckDeletable(type, props[i]);
   }
 }
 
 
-function CheckJSCSemantics(type, props, name) {
-  print(name);
-  for (var i = 0; i < props.length; i++) {
-    CheckNotDeletable(type, props[i]);
-  }
-}
-
-
 function CheckDontDelete(type, props, name) {
   print(name);
   for (var i = 0; i < props.length; i++) {
     CheckDontDeleteAttr(type, props[i]);
   }
 }
 
 
 function CheckDeletable(type, prop) {
   var old = type[prop];
   var hasOwnProperty = Object.prototype.hasOwnProperty;
   if (!type[prop]) return;
   assertTrue(type.hasOwnProperty(prop), "inherited: " + prop);
   var deleted = delete type[prop];
   assertTrue(deleted, "delete operator returned false: " + prop);
   assertFalse(hasOwnProperty.call(type, prop), "still there after delete: " + prop);
   type[prop] = "foo";
   assertEquals("foo", type[prop], "not overwritable: " + prop);
   type[prop] = old;
 }
 
 
-function CheckNotDeletable(type, prop) {
-  var old = type[prop];
-  if (!type[prop]) return;
-  assertTrue(type.hasOwnProperty(prop), "inherited: " + prop);
-  var deleted = delete type[prop];
-  assertTrue(deleted, "delete operator returned false: " + prop);
-  assertTrue(type.hasOwnProperty(prop), "not there after delete: " + prop);
-  type[prop] = "foo";
-  assertEquals("foo", type[prop], "not overwritable: " + prop);
-  deleted = delete type[prop];
-  assertTrue(deleted, "delete operator returned false 2nd time: " + prop);
-  assertEquals(old.toString(), type[prop].toString(), "delete didn't restore the old value: " + prop);
-}
-
-
 function CheckDontDeleteAttr(type, prop) {
   var old = type[prop];
   if (!type[prop]) return;
   assertTrue(type.hasOwnProperty(prop), "inherited: " + prop);
   var deleted = delete type[prop];
   assertFalse(deleted, "delete operator returned true: " + prop);
   assertTrue(type.hasOwnProperty(prop), "not there after delete: " + prop);
   type[prop] = "foo";
   assertFalse("foo" == type[prop], "overwritable: " + prop);
 }
 
 
 function CheckReadOnlyAttr(type, prop) {
   var old = type[prop];
   if (!type[prop]) return;
   assertTrue(type.hasOwnProperty(prop), "inherited: " + prop);
   var deleted = delete type[prop];
   assertFalse(deleted, "delete operator returned true: " + prop);
   assertTrue(type.hasOwnProperty(prop), "not there after delete: " + prop);
   type[prop] = "foo";
   assertEquals(old, type[prop], "overwritable: " + prop);
 }
 
 print("OK");