From ba6828c3d4d947a4ee01981fd013d55995444126 Mon Sep 17 00:00:00 2001
From: Steve Akinyemi <appcypher@outlook.com>
Date: Fri, 11 Jan 2019 17:10:59 +0100
Subject: [PATCH] Add memory offset addr impl

---
 lib/runtime/src/instance.rs | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/lib/runtime/src/instance.rs b/lib/runtime/src/instance.rs
index e9b23a7bd..b102832ab 100644
--- a/lib/runtime/src/instance.rs
+++ b/lib/runtime/src/instance.rs
@@ -344,7 +344,24 @@ impl Namespace for Instance {
 
 // TODO Remove this later, only needed for compilation till emscripten is updated
 impl Instance {
-    pub fn memory_offset_addr(&self, _index: usize, _offset: usize) -> *const usize {
-        unimplemented!("TODO replace this emscripten stub")
+    pub fn memory_offset_addr(&self, index: usize, offset: usize) -> *const u8 {
+        // Get vm context.
+        let vmctx = &self.vmctx;
+
+        // Check if the index specified refers to an imported memory.
+        if index < self.module.0.imported_memories.len() {
+            // Get imported memory at specified index.
+            let memory = unsafe { vmctx.imported_memories.add(index) };
+
+            // Get the actual address of the specified offset.
+            return unsafe { (*(*memory).memory).base.add(offset) }
+        }
+
+        // Index points to a locally-defined memory
+        // Get local memory at specified index.
+        let memory = unsafe { vmctx.memories.add(index) };
+
+        // Get the actual address of the specified offset.
+        unsafe { (*memory).base.add(offset) }
     }
 }