1 files changed, 72 insertions, 0 deletions
diff --git a/js/src/vm/StringObject.h b/js/src/vm/StringObject.h
new file mode 100644
index 0000000000..ad90e649f0
--- /dev/null
+++ b/js/src/vm/StringObject.h
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * 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/. */
+
+#ifndef vm_StringObject_h
+#define vm_StringObject_h
+
+#include "vm/JSObject.h"
+#include "vm/NativeObject.h"
+
+namespace js {
+
+class Shape;
+
+class StringObject : public NativeObject {
+  static const unsigned PRIMITIVE_VALUE_SLOT = 0;
+  static const unsigned LENGTH_SLOT = 1;
+
+  static const ClassSpec classSpec_;
+
+ public:
+  static const unsigned RESERVED_SLOTS = 2;
+
+  static const JSClass class_;
+
+  /*
+   * Creates a new String object boxing the given string.  The object's
+   * [[Prototype]] is determined from context.
+   */
+  static inline StringObject* create(JSContext* cx, HandleString str,
+                                     HandleObject proto = nullptr,
+                                     NewObjectKind newKind = GenericObject);
+
+  /*
+   * Compute the initial shape to associate with fresh String objects, which
+   * encodes the initial length property. Return the shape after changing
+   * |obj|'s last property to it.
+   */
+  static SharedShape* assignInitialShape(JSContext* cx,
+                                         Handle<StringObject*> obj);
+
+  JSString* unbox() const {
+    return getFixedSlot(PRIMITIVE_VALUE_SLOT).toString();
+  }
+
+  inline size_t length() const {
+    return size_t(getFixedSlot(LENGTH_SLOT).toInt32());
+  }
+
+  static size_t offsetOfPrimitiveValue() {
+    return getFixedSlotOffset(PRIMITIVE_VALUE_SLOT);
+  }
+  static size_t offsetOfLength() { return getFixedSlotOffset(LENGTH_SLOT); }
+
+ private:
+  static inline bool init(JSContext* cx, Handle<StringObject*> obj,
+                          HandleString str);
+
+  static JSObject* createPrototype(JSContext* cx, JSProtoKey key);
+
+  void setStringThis(JSString* str) {
+    MOZ_ASSERT(getReservedSlot(PRIMITIVE_VALUE_SLOT).isUndefined());
+    setFixedSlot(PRIMITIVE_VALUE_SLOT, StringValue(str));
+    setFixedSlot(LENGTH_SLOT, Int32Value(int32_t(str->length())));
+  }
+};
+
+}  // namespace js
+
+#endif /* vm_StringObject_h */