[wasm] Allow Uint8Array in _WASMEXP_.instantiateModule()

R=dschuff@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1767203002

Cr-Commit-Position: refs/heads/master@{#34565}

src/wasm/wasm-js.cc

@@ -37,20 +37,43 @@ struct RawBuffer {
 
 RawBuffer GetRawBufferArgument(
     ErrorThrower& thrower, const v8::FunctionCallbackInfo<v8::Value>& args) {
-  // TODO(titzer): allow typed array views.
-  if (args.Length() < 1 || !args[0]->IsArrayBuffer()) {
+  if (args.Length() < 1) {
     thrower.Error("Argument 0 must be an array buffer");
     return {nullptr, nullptr};
   }
-  Local<ArrayBuffer> buffer = Local<ArrayBuffer>::Cast(args[0]);
-  ArrayBuffer::Contents contents = buffer->GetContents();
 
-  const byte* start = reinterpret_cast<const byte*>(contents.Data());
-  const byte* end = start + contents.ByteLength();
+  const byte* start = nullptr;
+  const byte* end = nullptr;
 
-  if (start == nullptr) {
-    thrower.Error("ArrayBuffer argument is empty");
+  if (args[0]->IsArrayBuffer()) {
+    // A raw array buffer was passed.
+    Local<ArrayBuffer> buffer = Local<ArrayBuffer>::Cast(args[0]);
+    ArrayBuffer::Contents contents = buffer->GetContents();
+
+    start = reinterpret_cast<const byte*>(contents.Data());
+    end = start + contents.ByteLength();
+
+    if (start == nullptr || end == start) {
+      thrower.Error("ArrayBuffer argument is empty");
+    }
+  } else if (args[0]->IsTypedArray()) {
+    // A TypedArray was passed.
+    Local<TypedArray> array = Local<TypedArray>::Cast(args[0]);
+    Local<ArrayBuffer> buffer = array->Buffer();
+
+    ArrayBuffer::Contents contents = buffer->GetContents();
+
+    start =
+        reinterpret_cast<const byte*>(contents.Data()) + array->ByteOffset();
+    end = start + array->ByteLength();
+
+    if (start == nullptr || end == start) {
+      thrower.Error("ArrayBuffer argument is empty");
+    }
+  } else {
+    thrower.Error("Argument 0 must be an ArrayBuffer or Uint8Array");
   }
+
   return {start, end};
 }
 

test/mjsunit/wasm/test-wasm-module-builder.js

@@ -111,3 +111,30 @@ var debug = false;
     var instance = _WASMEXP_.instantiateModule(buffer);
     assertEquals(151587081, instance.exports.load(0));
 })();
+
+
+(function BasicTestWithUint8Array() {
+    var module = new WasmModuleBuilder();
+    module.addMemory(1, 2, false);
+    module.addFunction("foo", [kAstI32])
+        .addBody([kExprI8Const, 17])
+        .exportAs("blarg");
+
+    var buffer = module.toBuffer(debug);
+    var array = new Uint8Array(buffer);
+    var instance = _WASMEXP_.instantiateModule(array);
+    assertEquals(17, instance.exports.blarg());
+
+    var kPad = 5;
+    var buffer2 = new ArrayBuffer(kPad + buffer.byteLength + kPad);
+    var whole = new Uint8Array(buffer2);
+    for (var i = 0; i < whole.byteLength; i++) {
+      whole[i] = 0xff;
+    }
+    var array2 = new Uint8Array(buffer2, kPad, buffer.byteLength);
+    for (var i = 0; i < array2.byteLength; i++) {
+      array2[i] = array[i];
+    }
+    var instance = _WASMEXP_.instantiateModule(array2);
+    assertEquals(17, instance.exports.blarg());
+})();