From b76456f0ed8b9dba63ec2746d8f5f244b3db4e30 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 8 Sep 2021 22:58:36 +0200
Subject: [PATCH] LibJS: Add a way to attach custom data to a JS::VM instance

This will be used by LibWeb to attach web engine specific stuff that
LibJS doesn't need to know about.
---
 Userland/Libraries/LibJS/Runtime/VM.cpp | 11 ++++++++---
 Userland/Libraries/LibJS/Runtime/VM.h   | 12 ++++++++++--
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/VM.cpp b/Userland/Libraries/LibJS/Runtime/VM.cpp
index a0e0acceb8..1f4eb9b1bb 100644
--- a/Userland/Libraries/LibJS/Runtime/VM.cpp
+++ b/Userland/Libraries/LibJS/Runtime/VM.cpp
@@ -28,13 +28,14 @@
 
 namespace JS {
 
-NonnullRefPtr<VM> VM::create()
+NonnullRefPtr<VM> VM::create(OwnPtr<CustomData> custom_data)
 {
-    return adopt_ref(*new VM);
+    return adopt_ref(*new VM(move(custom_data)));
 }
 
-VM::VM()
+VM::VM(OwnPtr<CustomData> custom_data)
     : m_heap(*this)
+    , m_custom_data(move(custom_data))
 {
     m_empty_string = m_heap.allocate_without_global_object<PrimitiveString>(String::empty());
     for (size_t i = 0; i < 128; ++i) {
@@ -773,4 +774,8 @@ void VM::dump_environment_chain() const
     }
 }
 
+VM::CustomData::~CustomData()
+{
+}
+
 }
diff --git a/Userland/Libraries/LibJS/Runtime/VM.h b/Userland/Libraries/LibJS/Runtime/VM.h
index 5f8c4e1a72..c3ea351d9a 100644
--- a/Userland/Libraries/LibJS/Runtime/VM.h
+++ b/Userland/Libraries/LibJS/Runtime/VM.h
@@ -61,7 +61,11 @@ struct ExecutionContext {
 
 class VM : public RefCounted<VM> {
 public:
-    static NonnullRefPtr<VM> create();
+    struct CustomData {
+        virtual ~CustomData();
+    };
+
+    static NonnullRefPtr<VM> create(OwnPtr<CustomData> = {});
     ~VM();
 
     Heap& heap() { return m_heap; }
@@ -272,8 +276,10 @@ public:
 
     void initialize_instance_elements(Object& object, FunctionObject& constructor);
 
+    CustomData* custom_data() { return m_custom_data; }
+
 private:
-    VM();
+    explicit VM(OwnPtr<CustomData>);
 
     void ordinary_call_bind_this(FunctionObject&, ExecutionContext&, Value this_argument);
 
@@ -310,6 +316,8 @@ private:
     bool m_underscore_is_last_value { false };
 
     u32 m_execution_generation { 0 };
+
+    OwnPtr<CustomData> m_custom_data;
 };
 
 template<>