From e96ef450f6ffb049675dc033a561ad3791443f47 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 18 Mar 2020 15:20:49 +0100
Subject: [PATCH] LibJS: Add Interpreter::call(Function*, this_value,
 arguments)

This helper function takes care of pushing/popping a call frame so you
don't need to worry about it.
---
 Libraries/LibJS/Interpreter.cpp | 10 ++++++++++
 Libraries/LibJS/Interpreter.h   |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/Libraries/LibJS/Interpreter.cpp b/Libraries/LibJS/Interpreter.cpp
index 8f36fe58e2..6c6b1563f2 100644
--- a/Libraries/LibJS/Interpreter.cpp
+++ b/Libraries/LibJS/Interpreter.cpp
@@ -161,4 +161,14 @@ void Interpreter::gather_roots(Badge<Heap>, HashTable<Cell*>& roots)
     }
 }
 
+Value Interpreter::call(Function* function, Value this_value, const Vector<Value>& arguments)
+{
+    auto& call_frame = push_call_frame();
+    call_frame.this_value = this_value;
+    call_frame.arguments = arguments;
+    auto result = function->call(*this, call_frame.arguments);
+    pop_call_frame();
+    return result;
+}
+
 }
diff --git a/Libraries/LibJS/Interpreter.h b/Libraries/LibJS/Interpreter.h
index 727cc67629..fd4e92ecb8 100644
--- a/Libraries/LibJS/Interpreter.h
+++ b/Libraries/LibJS/Interpreter.h
@@ -84,6 +84,8 @@ public:
     void enter_scope(const ScopeNode&, Vector<Argument>, ScopeType);
     void exit_scope(const ScopeNode&);
 
+    Value call(Function*, Value this_value, const Vector<Value>& arguments);
+
     CallFrame& push_call_frame() { m_call_stack.append({ js_undefined(), {} }); return m_call_stack.last(); }
     void pop_call_frame() { m_call_stack.take_last(); }
     Value this_value() const