[Backport] Merged: [wasm] Call AsyncInstantiate directly when instantiating a module objectv5.11.0-rc2v5.11.0

WebAssembly.instantiate is polymorphic, it can either take a module
object as parameter, or a buffer source which should be compiled first.
To share code between the two implementations, the module object was
first passed to a promise (i.e. which is the result of compilation).
However, passing the module object to a promise has a side effect if
the module object has a then function. To avoid this side effect I
remove this code sharing and call AsyncInstantiate directly in case
the parameter is a module object.

NOTRY=true
NOPRESUBMIT=true
NOTREECHECK=true

R=​mstarzinger@chromium.org

Bug: chromium:836141
Reviewed-on: https://chromium-review.googlesource.com/1025774
Reviewed-on: https://chromium-review.googlesource.com/1027875

Change-Id: I66837c83f01760e6b5e141394e0043d0547c6f69
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 32 insertions, 39 deletions

diff --git a/chromium/v8/src/wasm/wasm-js.cc b/chromium/v8/src/wasm/wasm-js.cc
index ce2bf42455b..aa3f2b3f11f 100644
--- a/chromium/v8/src/wasm/wasm-js.cc
+++ b/chromium/v8/src/wasm/wasm-js.cc
@@ -322,25 +322,7 @@ MaybeLocal<Value> WebAssemblyInstantiateImpl(Isolate* isolate,
   return Utils::ToLocal(instance_object.ToHandleChecked());
 }
 
-// Entered as internal implementation detail of sync and async instantiate.
-// args[0] *must* be a WebAssembly.Module.
-void WebAssemblyInstantiateImplCallback(
-    const v8::FunctionCallbackInfo<v8::Value>& args) {
-  DCHECK_GE(args.Length(), 1);
-  v8::Isolate* isolate = args.GetIsolate();
-  MicrotasksScope does_not_run_microtasks(isolate,
-                                          MicrotasksScope::kDoNotRunMicrotasks);
-
-  HandleScope scope(args.GetIsolate());
-  Local<Value> module = args[0];
-  Local<Value> ffi = args.Data();
-  Local<Value> instance;
-  if (WebAssemblyInstantiateImpl(isolate, module, ffi).ToLocal(&instance)) {
-    args.GetReturnValue().Set(instance);
-  }
-}
-
-void WebAssemblyInstantiateToPairCallback(
+void WebAssemblyInstantiateCallback(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   DCHECK_GE(args.Length(), 1);
   Isolate* isolate = args.GetIsolate();
@@ -429,7 +411,7 @@ void WebAssemblyInstantiateStreaming(
   DCHECK(!module_promise.IsEmpty());
   Local<Value> data = args[1];
   ASSIGN(Function, instantiate_impl,
-         Function::New(context, WebAssemblyInstantiateToPairCallback, data));
+         Function::New(context, WebAssemblyInstantiateCallback, data));
   ASSIGN(Promise, result, module_promise->Then(context, instantiate_impl));
   args.GetReturnValue().Set(result);
 }
@@ -452,10 +434,12 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Local<Context> context = isolate->GetCurrentContext();
 
   ASSIGN(Promise::Resolver, resolver, Promise::Resolver::New(context));
-  Local<Promise> module_promise = resolver->GetPromise();
-  args.GetReturnValue().Set(module_promise);
+  Local<Promise> promise = resolver->GetPromise();
+  args.GetReturnValue().Set(promise);
 
   Local<Value> first_arg_value = args[0];
+  // If args.Length < 2, this will be undefined - see FunctionCallbackInfo.
+  Local<Value> ffi = args[1];
   i::Handle<i::Object> first_arg = Utils::OpenHandle(*first_arg_value);
   if (!first_arg->IsJSObject()) {
     thrower.TypeError(
@@ -466,26 +450,35 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
     return;
   }
 
-  FunctionCallback instantiator = nullptr;
   if (first_arg->IsWasmModuleObject()) {
-    module_promise = resolver->GetPromise();
-    if (!resolver->Resolve(context, first_arg_value).IsJust()) return;
-    instantiator = WebAssemblyInstantiateImplCallback;
-  } else {
-    ASSIGN(Function, async_compile, Function::New(context, WebAssemblyCompile));
-    ASSIGN(Value, async_compile_retval,
-           async_compile->Call(context, args.Holder(), 1, &first_arg_value));
-    module_promise = Local<Promise>::Cast(async_compile_retval);
-    instantiator = WebAssemblyInstantiateToPairCallback;
+    i::Handle<i::WasmModuleObject> module_obj =
+        i::Handle<i::WasmModuleObject>::cast(first_arg);
+    // If args.Length < 2, this will be undefined - see FunctionCallbackInfo.
+    i::MaybeHandle<i::JSReceiver> maybe_imports =
+        GetValueAsImports(ffi, &thrower);
+
+    if (thrower.error()) {
+      auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+      CHECK_IMPLIES(!maybe.FromMaybe(false),
+                    i_isolate->has_scheduled_exception());
+      return;
+    }
+
+    i::wasm::AsyncInstantiate(
+        i_isolate, Utils::OpenHandle(*promise), module_obj, maybe_imports);
+    return;
   }
-  DCHECK(!module_promise.IsEmpty());
-  DCHECK_NOT_NULL(instantiator);
-  // If args.Length < 2, this will be undefined - see FunctionCallbackInfo.
-  // We'll check for that in WebAssemblyInstantiateImpl.
-  Local<Value> data = args[1];
+
+  // We did not get a WasmModuleObject as input, we first have to compile the
+  // input.
+  ASSIGN(Function, async_compile, Function::New(context, WebAssemblyCompile));
+  ASSIGN(Value, async_compile_retval,
+         async_compile->Call(context, args.Holder(), 1, &first_arg_value));
+  promise = Local<Promise>::Cast(async_compile_retval);
+  DCHECK(!promise.IsEmpty());
   ASSIGN(Function, instantiate_impl,
-         Function::New(context, instantiator, data));
-  ASSIGN(Promise, result, module_promise->Then(context, instantiate_impl));
+         Function::New(context, WebAssemblyInstantiateCallback, ffi));
+  ASSIGN(Promise, result, promise->Then(context, instantiate_impl));
   args.GetReturnValue().Set(result);
 }