LibJS: Add a new PrimitiveString class to hold GC-allocated strings

Libraries/LibJS/Forward.h

@@ -34,6 +34,7 @@ class Heap;
 class HeapBlock;
 class Interpreter;
 class Object;
+class PrimitiveString;
 class ScopeNode;
 class Value;
 

Libraries/LibJS/Makefile

@@ -6,6 +6,7 @@ OBJS = \
     HeapBlock.o \
     Interpreter.o \
     Object.o \
+    PrimitiveString.o \
     Value.o
 
 LIBRARY = libjs.a

Libraries/LibJS/PrimitiveString.cpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#include <LibJS/Heap.h>
+#include <LibJS/PrimitiveString.h>
+
+namespace JS {
+
+PrimitiveString::PrimitiveString(String string)
+    : m_string(move(string))
+{
+}
+
+PrimitiveString::~PrimitiveString()
+{
+}
+
+PrimitiveString* js_string(Heap& heap, String string)
+{
+    return heap.allocate<PrimitiveString>(move(string));
+}
+
+}

Libraries/LibJS/PrimitiveString.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <LibJS/Cell.h>
+
+namespace JS {
+
+class PrimitiveString final : public Cell {
+public:
+    explicit PrimitiveString(String);
+    virtual ~PrimitiveString();
+
+    const String& string() const { return m_string; }
+
+private:
+    virtual const char* class_name() const override { return "PrimitiveString"; }
+
+    String m_string;
+};
+
+PrimitiveString* js_string(Heap&, String);
+
+}