Merge pull request #759 from WebAssembly/js-api

memory growth fixes

2 files changed, 13 insertions, 2 deletions

diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 9b503c84d..9bf677e6f 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -981,6 +981,7 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
   // apply memory growth, if relevant
   if (memoryGrowth) {
     emscripten::generateMemoryGrowthFunction(wasm);
+    wasm.memory.max = Memory::kMaxSize;
   }
 
 #if 0
diff --git a/src/js/wasm.js-post.js b/src/js/wasm.js-post.js
index f093ff64d..a4bc35f97 100644
--- a/src/js/wasm.js-post.js
+++ b/src/js/wasm.js-post.js
@@ -269,8 +269,18 @@ function integrateWasmJS(Module) {
   Module['reallocBuffer'] = function(size) {
     size = Math.ceil(size / wasmPageSize) * wasmPageSize; // round up to wasm page size
     var old = Module['buffer'];
-    exports['__growWasmMemory'](size / wasmPageSize); // tiny wasm method that just does grow_memory
-    return Module['buffer'] !== old ? Module['buffer'] : null; // if it was reallocated, it changed
+    var result = exports['__growWasmMemory'](size / wasmPageSize); // tiny wasm method that just does grow_memory
+    if (Module["usingWasm"]) {
+      if (result !== (-1 | 0)) {
+        // success in native wasm memory growth, get the buffer from the memory
+        return Module['buffer'] = Module['wasmMemory'].buffer;
+      } else {
+        return null;
+      }
+    } else {
+      // in interpreter, we replace Module.buffer if we allocate
+      return Module['buffer'] !== old ? Module['buffer'] : null; // if it was reallocated, it changed
+    }
   };
 
   // Provide an "asm.js function" for the application, called to "link" the asm.js module. We instantiate