v8/test/mjsunit/builtins.js
lrn@chromium.org 2c8680cc46 Avoid size increase of snapshot.
The prototype of builtin functions is already unwritable, so we don't
have to make it so (the default map for functions changes after builtins
are initialized).

We no longer need to make the prototype non-extensible, since all properties
that are ever read by the bultins code has been added and frozen already.
Adding properties to the prototype, or changing its __proto__, cannot affect
code.

Removing these two pieces of initialization code reduces the snapshot size
by a few Kb.

Review URL: http://codereview.chromium.org/7839028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9166 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2011-09-07 11:56:06 +00:00

83 lines
3.5 KiB
JavaScript

// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Flags: --expose-natives-as=builtins
// Checks that all function properties of the builtin object are neither
// writable nor configurable. Also, theose functions that are actually
// constructors (recognized by having properties on their .prototype object),
// have only unconfigurable properties on the prototype, and the methods
// are also non-writable.
var names = Object.getOwnPropertyNames(builtins);
function isFunction(obj) {
return typeof obj == "function";
}
function checkConstructor(func, name) {
// A constructor is a function with a prototype and properties on the
// prototype object besides "constructor";
if (name.charAt(0) == "$") return;
if (typeof func.prototype != "object") return;
var propNames = Object.getOwnPropertyNames(func.prototype);
if (propNames.length == 0 ||
(propNames.length == 1 && propNames[0] == "constructor")) {
// Not a constructor.
return;
}
var proto_desc = Object.getOwnPropertyDescriptor(func, "prototype");
assertTrue(proto_desc.hasOwnProperty("value"), name);
assertFalse(proto_desc.writable, name);
assertFalse(proto_desc.configurable, name);
var prototype = proto_desc.value;
assertEquals(null, prototype.__proto__, name);
for (var i = 0; i < propNames.length; i++) {
var propName = propNames[i];
if (propName == "constructor") continue;
var testName = name + "-" + propName;
var propDesc = Object.getOwnPropertyDescriptor(prototype, propName);
assertTrue(propDesc.hasOwnProperty("value"), testName);
assertFalse(propDesc.configurable, testName);
if (isFunction(propDesc.value)) {
assertFalse(propDesc.writable, testName);
}
}
}
for (var i = 0; i < names.length; i++) {
var name = names[i];
var desc = Object.getOwnPropertyDescriptor(builtins, name);
assertTrue(desc.hasOwnProperty("value"));
var value = desc.value;
if (isFunction(value)) {
assertFalse(desc.writable, name);
assertFalse(desc.configurable, name);
checkConstructor(value, name);
}
}