1 files changed, 234 insertions, 0 deletions
diff --git a/js/src/builtin/SymbolObject.cpp b/js/src/builtin/SymbolObject.cpp
new file mode 100644
index 000000000..cf48402d6
--- /dev/null
+++ b/js/src/builtin/SymbolObject.cpp
@@ -0,0 +1,234 @@
+/* -*- 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/. */
+
+#include "builtin/SymbolObject.h"
+
+#include "vm/StringBuffer.h"
+#include "vm/Symbol.h"
+
+#include "jsobjinlines.h"
+
+#include "vm/NativeObject-inl.h"
+
+using JS::Symbol;
+using namespace js;
+
+const Class SymbolObject::class_ = {
+    "Symbol",
+    JSCLASS_HAS_RESERVED_SLOTS(RESERVED_SLOTS) | JSCLASS_HAS_CACHED_PROTO(JSProto_Symbol)
+};
+
+SymbolObject*
+SymbolObject::create(JSContext* cx, JS::HandleSymbol symbol)
+{
+    JSObject* obj = NewBuiltinClassInstance(cx, &class_);
+    if (!obj)
+        return nullptr;
+    SymbolObject& symobj = obj->as<SymbolObject>();
+    symobj.setPrimitiveValue(symbol);
+    return &symobj;
+}
+
+const JSPropertySpec SymbolObject::properties[] = {
+    JS_PS_END
+};
+
+const JSFunctionSpec SymbolObject::methods[] = {
+    JS_FN(js_toString_str, toString, 0, 0),
+    JS_FN(js_valueOf_str, valueOf, 0, 0),
+    JS_SYM_FN(toPrimitive, toPrimitive, 1, JSPROP_READONLY),
+    JS_FS_END
+};
+
+const JSFunctionSpec SymbolObject::staticMethods[] = {
+    JS_FN("for", for_, 1, 0),
+    JS_FN("keyFor", keyFor, 1, 0),
+    JS_FS_END
+};
+
+JSObject*
+SymbolObject::initClass(JSContext* cx, HandleObject obj)
+{
+    Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
+
+    // This uses &JSObject::class_ because: "The Symbol prototype object is an
+    // ordinary object. It is not a Symbol instance and does not have a
+    // [[SymbolData]] internal slot." (ES6 rev 24, 19.4.3)
+    RootedObject proto(cx, global->createBlankPrototype<PlainObject>(cx));
+    if (!proto)
+        return nullptr;
+
+    RootedFunction ctor(cx, global->createConstructor(cx, construct,
+                                                      ClassName(JSProto_Symbol, cx), 0));
+    if (!ctor)
+        return nullptr;
+
+    // Define the well-known symbol properties, such as Symbol.iterator.
+    ImmutablePropertyNamePtr* names = cx->names().wellKnownSymbolNames();
+    RootedValue value(cx);
+    unsigned attrs = JSPROP_READONLY | JSPROP_PERMANENT;
+    WellKnownSymbols* wks = cx->runtime()->wellKnownSymbols;
+    for (size_t i = 0; i < JS::WellKnownSymbolLimit; i++) {
+        value.setSymbol(wks->get(i));
+        if (!NativeDefineProperty(cx, ctor, names[i], value, nullptr, nullptr, attrs))
+            return nullptr;
+    }
+
+    if (!LinkConstructorAndPrototype(cx, ctor, proto) ||
+        !DefinePropertiesAndFunctions(cx, proto, properties, methods) ||
+        !DefineToStringTag(cx, proto, cx->names().Symbol) ||
+        !DefinePropertiesAndFunctions(cx, ctor, nullptr, staticMethods) ||
+        !GlobalObject::initBuiltinConstructor(cx, global, JSProto_Symbol, ctor, proto))
+    {
+        return nullptr;
+    }
+    return proto;
+}
+
+// ES6 rev 24 (2014 Apr 27) 19.4.1.1 and 19.4.1.2
+bool
+SymbolObject::construct(JSContext* cx, unsigned argc, Value* vp)
+{
+    // According to a note in the draft standard, "Symbol has ordinary
+    // [[Construct]] behaviour but the definition of its @@create method causes
+    // `new Symbol` to throw a TypeError exception." We do not support @@create
+    // yet, so just throw a TypeError.
+    CallArgs args = CallArgsFromVp(argc, vp);
+    if (args.isConstructing()) {
+        JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_NOT_CONSTRUCTOR, "Symbol");
+        return false;
+    }
+
+    // steps 1-3
+    RootedString desc(cx);
+    if (!args.get(0).isUndefined()) {
+        desc = ToString(cx, args.get(0));
+        if (!desc)
+            return false;
+    }
+
+    // step 4
+    RootedSymbol symbol(cx, JS::Symbol::new_(cx, JS::SymbolCode::UniqueSymbol, desc));
+    if (!symbol)
+        return false;
+    args.rval().setSymbol(symbol);
+    return true;
+}
+
+// ES6 rev 24 (2014 Apr 27) 19.4.2.2
+bool
+SymbolObject::for_(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // steps 1-2
+    RootedString stringKey(cx, ToString(cx, args.get(0)));
+    if (!stringKey)
+        return false;
+
+    // steps 3-7
+    JS::Symbol* symbol = JS::Symbol::for_(cx, stringKey);
+    if (!symbol)
+        return false;
+    args.rval().setSymbol(symbol);
+    return true;
+}
+
+// ES6 rev 25 (2014 May 22) 19.4.2.7
+bool
+SymbolObject::keyFor(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // step 1
+    HandleValue arg = args.get(0);
+    if (!arg.isSymbol()) {
+        ReportValueErrorFlags(cx, JSREPORT_ERROR, JSMSG_UNEXPECTED_TYPE, JSDVG_SEARCH_STACK,
+                              arg, nullptr, "not a symbol", nullptr);
+        return false;
+    }
+
+    // step 2
+    if (arg.toSymbol()->code() == JS::SymbolCode::InSymbolRegistry) {
+#ifdef DEBUG
+        RootedString desc(cx, arg.toSymbol()->description());
+        MOZ_ASSERT(Symbol::for_(cx, desc) == arg.toSymbol());
+#endif
+        args.rval().setString(arg.toSymbol()->description());
+        return true;
+    }
+
+    // step 3: omitted
+    // step 4
+    args.rval().setUndefined();
+    return true;
+}
+
+MOZ_ALWAYS_INLINE bool
+IsSymbol(HandleValue v)
+{
+    return v.isSymbol() || (v.isObject() && v.toObject().is<SymbolObject>());
+}
+
+// ES6 rev 27 (2014 Aug 24) 19.4.3.2
+bool
+SymbolObject::toString_impl(JSContext* cx, const CallArgs& args)
+{
+    // steps 1-3
+    HandleValue thisv = args.thisv();
+    MOZ_ASSERT(IsSymbol(thisv));
+    Rooted<Symbol*> sym(cx, thisv.isSymbol()
+                            ? thisv.toSymbol()
+                            : thisv.toObject().as<SymbolObject>().unbox());
+
+    // step 4
+    return SymbolDescriptiveString(cx, sym, args.rval());
+}
+
+bool
+SymbolObject::toString(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsSymbol, toString_impl>(cx, args);
+}
+
+//ES6 rev 24 (2014 Apr 27) 19.4.3.3
+bool
+SymbolObject::valueOf_impl(JSContext* cx, const CallArgs& args)
+{
+    // Step 3, the error case, is handled by CallNonGenericMethod.
+    HandleValue thisv = args.thisv();
+    MOZ_ASSERT(IsSymbol(thisv));
+    if (thisv.isSymbol())
+        args.rval().set(thisv);
+    else
+        args.rval().setSymbol(thisv.toObject().as<SymbolObject>().unbox());
+    return true;
+}
+
+bool
+SymbolObject::valueOf(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsSymbol, valueOf_impl>(cx, args);
+}
+
+// ES6 19.4.3.4
+bool
+SymbolObject::toPrimitive(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // The specification gives exactly the same algorithm for @@toPrimitive as
+    // for valueOf, so reuse the valueOf implementation.
+    return CallNonGenericMethod<IsSymbol, valueOf_impl>(cx, args);
+}
+
+JSObject*
+js::InitSymbolClass(JSContext* cx, HandleObject obj)
+{
+    return SymbolObject::initClass(cx, obj);
+}