diff -r 000000000000 -r 6474c204b198 js/src/jsbool.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsbool.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,204 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * JS boolean implementation.
+ */
+
+#include "jsboolinlines.h"
+
+#include "jsapi.h"
+#include "jsatom.h"
+#include "jscntxt.h"
+#include "jsobj.h"
+#include "jstypes.h"
+
+#include "vm/GlobalObject.h"
+#include "vm/ProxyObject.h"
+#include "vm/StringBuffer.h"
+
+#include "vm/BooleanObject-inl.h"
+
+using namespace js;
+using namespace js::types;
+
+const Class BooleanObject::class_ = {
+    "Boolean",
+    JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Boolean),
+    JS_PropertyStub,         /* addProperty */
+    JS_DeletePropertyStub,   /* delProperty */
+    JS_PropertyStub,         /* getProperty */
+    JS_StrictPropertyStub,   /* setProperty */
+    JS_EnumerateStub,
+    JS_ResolveStub,
+    JS_ConvertStub
+};
+
+MOZ_ALWAYS_INLINE bool
+IsBoolean(HandleValue v)
+{
+    return v.isBoolean() || (v.isObject() && v.toObject().is<BooleanObject>());
+}
+
+#if JS_HAS_TOSOURCE
+MOZ_ALWAYS_INLINE bool
+bool_toSource_impl(JSContext *cx, CallArgs args)
+{
+    HandleValue thisv = args.thisv();
+    JS_ASSERT(IsBoolean(thisv));
+
+    bool b = thisv.isBoolean() ? thisv.toBoolean() : thisv.toObject().as<BooleanObject>().unbox();
+
+    StringBuffer sb(cx);
+    if (!sb.append("(new Boolean(") || !BooleanToStringBuffer(b, sb) || !sb.append("))"))
+        return false;
+
+    JSString *str = sb.finishString();
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+}
+
+static bool
+bool_toSource(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsBoolean, bool_toSource_impl>(cx, args);
+}
+#endif
+
+MOZ_ALWAYS_INLINE bool
+bool_toString_impl(JSContext *cx, CallArgs args)
+{
+    HandleValue thisv = args.thisv();
+    JS_ASSERT(IsBoolean(thisv));
+
+    bool b = thisv.isBoolean() ? thisv.toBoolean() : thisv.toObject().as<BooleanObject>().unbox();
+    args.rval().setString(js_BooleanToString(cx, b));
+    return true;
+}
+
+static bool
+bool_toString(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsBoolean, bool_toString_impl>(cx, args);
+}
+
+MOZ_ALWAYS_INLINE bool
+bool_valueOf_impl(JSContext *cx, CallArgs args)
+{
+    HandleValue thisv = args.thisv();
+    JS_ASSERT(IsBoolean(thisv));
+
+    bool b = thisv.isBoolean() ? thisv.toBoolean() : thisv.toObject().as<BooleanObject>().unbox();
+    args.rval().setBoolean(b);
+    return true;
+}
+
+static bool
+bool_valueOf(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsBoolean, bool_valueOf_impl>(cx, args);
+}
+
+static const JSFunctionSpec boolean_methods[] = {
+#if JS_HAS_TOSOURCE
+    JS_FN(js_toSource_str,  bool_toSource,  0, 0),
+#endif
+    JS_FN(js_toString_str,  bool_toString,  0, 0),
+    JS_FS_END
+};
+
+static bool
+Boolean(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    bool b = args.length() != 0 ? JS::ToBoolean(args[0]) : false;
+
+    if (args.isConstructing()) {
+        JSObject *obj = BooleanObject::create(cx, b);
+        if (!obj)
+            return false;
+        args.rval().setObject(*obj);
+    } else {
+        args.rval().setBoolean(b);
+    }
+    return true;
+}
+
+JSObject *
+js_InitBooleanClass(JSContext *cx, HandleObject obj)
+{
+    JS_ASSERT(obj->isNative());
+
+    Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
+
+    RootedObject booleanProto (cx, global->createBlankPrototype(cx, &BooleanObject::class_));
+    if (!booleanProto)
+        return nullptr;
+    booleanProto->setFixedSlot(BooleanObject::PRIMITIVE_VALUE_SLOT, BooleanValue(false));
+
+    RootedFunction ctor(cx, global->createConstructor(cx, Boolean, cx->names().Boolean, 1));
+    if (!ctor)
+        return nullptr;
+
+    if (!LinkConstructorAndPrototype(cx, ctor, booleanProto))
+        return nullptr;
+
+    if (!DefinePropertiesAndBrand(cx, booleanProto, nullptr, boolean_methods))
+        return nullptr;
+
+    Handle<PropertyName*> valueOfName = cx->names().valueOf;
+    RootedFunction
+        valueOf(cx, NewFunction(cx, NullPtr(), bool_valueOf, 0, JSFunction::NATIVE_FUN,
+                                global, valueOfName));
+    if (!valueOf)
+        return nullptr;
+
+    RootedValue value(cx, ObjectValue(*valueOf));
+    if (!JSObject::defineProperty(cx, booleanProto, valueOfName, value,
+                                  JS_PropertyStub, JS_StrictPropertyStub, 0))
+    {
+        return nullptr;
+    }
+
+    if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_Boolean, ctor, booleanProto))
+        return nullptr;
+
+    return booleanProto;
+}
+
+JSString *
+js_BooleanToString(ExclusiveContext *cx, bool b)
+{
+    return b ? cx->names().true_ : cx->names().false_;
+}
+
+JS_PUBLIC_API(bool)
+js::ToBooleanSlow(HandleValue v)
+{
+    if (v.isString())
+        return v.toString()->length() != 0;
+
+    JS_ASSERT(v.isObject());
+    return !EmulatesUndefined(&v.toObject());
+}
+
+/*
+ * This slow path is only ever taken for proxies wrapping Boolean objects
+ * The only caller of the fast path, JSON's PreprocessValue, ensures that.
+ */
+bool
+js::BooleanGetPrimitiveValueSlow(HandleObject wrappedBool)
+{
+    JSObject *obj = wrappedBool->as<ProxyObject>().target();
+    JS_ASSERT(obj);
+    return obj->as<BooleanObject>().unbox();
+}