CSE2410 Fall 2014 Bounce

// 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.

"use strict";

// This file relies on the fact that the following declaration has been made

// in runtime.js:

// var $Object = global.Object;

var $Proxy = new $Object();

// -------------------------------------------------------------------

function ProxyCreate(handler, proto) {

  if (!IS_SPEC_OBJECT(handler))

    throw MakeTypeError("handler_non_object", ["create"])

  if (IS_UNDEFINED(proto))

    proto = null

  else if (!(IS_SPEC_OBJECT(proto) || IS_NULL(proto)))

    throw MakeTypeError("proto_non_object", ["create"])

  return %CreateJSProxy(handler, proto)

}

function ProxyCreateFunction(handler, callTrap, constructTrap) {

  if (!IS_SPEC_OBJECT(handler))

    throw MakeTypeError("handler_non_object", ["create"])

  if (!IS_SPEC_FUNCTION(callTrap))

    throw MakeTypeError("trap_function_expected", ["createFunction", "call"])

  if (IS_UNDEFINED(constructTrap)) {

    constructTrap = DerivedConstructTrap(callTrap)

  } else if (IS_SPEC_FUNCTION(constructTrap)) {

    // Make sure the trap receives 'undefined' as this.

    var construct = constructTrap

    constructTrap = function() {

      return %Apply(construct, UNDEFINED, arguments, 0, %_ArgumentsLength());

    }

  } else {

    throw MakeTypeError("trap_function_expected",

                        ["createFunction", "construct"])

  }

  return %CreateJSFunctionProxy(

    handler, callTrap, constructTrap, $Function.prototype)

}

// -------------------------------------------------------------------

function SetUpProxy() {

  %CheckIsBootstrapping()

  global.Proxy = $Proxy;

  // Set up non-enumerable properties of the Proxy object.

  InstallFunctions($Proxy, DONT_ENUM, [

    "create", ProxyCreate,

    "createFunction", ProxyCreateFunction

  ])

}

SetUpProxy();

// -------------------------------------------------------------------

// Proxy Builtins

function DerivedConstructTrap(callTrap) {

  return function() {

    var proto = this.prototype

    if (!IS_SPEC_OBJECT(proto)) proto = $Object.prototype

    var obj = { __proto__: proto };

    var result = %Apply(callTrap, obj, arguments, 0, %_ArgumentsLength());

    return IS_SPEC_OBJECT(result) ? result : obj

  }

}

function DelegateCallAndConstruct(callTrap, constructTrap) {

  return function() {

    return %Apply(%_IsConstructCall() ? constructTrap : callTrap,

                  this, arguments, 0, %_ArgumentsLength())

  }

}

function DerivedGetTrap(receiver, name) {

  var desc = this.getPropertyDescriptor(name)

  if (IS_UNDEFINED(desc)) { return desc }

  if ('value' in desc) {

    return desc.value

  } else {

    if (IS_UNDEFINED(desc.get)) { return desc.get }

    // The proposal says: desc.get.call(receiver)

    return %_CallFunction(receiver, desc.get)

  }

}

function DerivedSetTrap(receiver, name, val) {

  var desc = this.getOwnPropertyDescriptor(name)

  if (desc) {

    if ('writable' in desc) {

      if (desc.writable) {

        desc.value = val

        this.defineProperty(name, desc)

        return true

      } else {

        return false

      }

    } else { // accessor

      if (desc.set) {

        // The proposal says: desc.set.call(receiver, val)

        %_CallFunction(receiver, val, desc.set)

        return true

      } else {

        return false

      }

    }

  }

  desc = this.getPropertyDescriptor(name)

  if (desc) {

    if ('writable' in desc) {

      if (desc.writable) {

        // fall through

      } else {

        return false

      }

    } else { // accessor

      if (desc.set) {

        // The proposal says: desc.set.call(receiver, val)

        %_CallFunction(receiver, val, desc.set)

        return true

      } else {

        return false

      }

    }

  }

  this.defineProperty(name, {

    value: val,

    writable: true,

    enumerable: true,

    configurable: true});

  return true;

}

function DerivedHasTrap(name) {

  return !!this.getPropertyDescriptor(name)

}

function DerivedHasOwnTrap(name) {

  return !!this.getOwnPropertyDescriptor(name)

}

function DerivedKeysTrap() {

  var names = this.getOwnPropertyNames()

  var enumerableNames = []

  for (var i = 0, count = 0; i < names.length; ++i) {

    var name = names[i]

    if (IS_SYMBOL(name)) continue

    var desc = this.getOwnPropertyDescriptor(TO_STRING_INLINE(name))

    if (!IS_UNDEFINED(desc) && desc.enumerable) {

      enumerableNames[count++] = names[i]

    }

  }

  return enumerableNames

}

function DerivedEnumerateTrap() {

  var names = this.getPropertyNames()

  var enumerableNames = []

  for (var i = 0, count = 0; i < names.length; ++i) {

    var name = names[i]

    if (IS_SYMBOL(name)) continue

    var desc = this.getPropertyDescriptor(TO_STRING_INLINE(name))

    if (!IS_UNDEFINED(desc)) {

      if (!desc.configurable) {

        throw MakeTypeError("proxy_prop_not_configurable",

            [this, "getPropertyDescriptor", name])

      }

      if (desc.enumerable) enumerableNames[count++] = names[i]

    }

  }

  return enumerableNames

}

function ProxyEnumerate(proxy) {

  var handler = %GetHandler(proxy)

  if (IS_UNDEFINED(handler.enumerate)) {

    return %Apply(DerivedEnumerateTrap, handler, [], 0, 0)

  } else {

    return ToNameArray(handler.enumerate(), "enumerate", false)

  }

}