Implement Instance instances correctly; fix a few error cases

R=titzer@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2620263003
Cr-Commit-Position: refs/heads/master@{#42288}

src/bootstrapper.cc

@@ -4166,8 +4166,6 @@ bool Genesis::InstallSpecialObjects(Handle<Context> native_context) {
 
   Factory* factory = isolate->factory();
   HandleScope scope(isolate);
-  Handle<JSGlobalObject> global(JSGlobalObject::cast(
-      native_context->global_object()));
 
   Handle<JSObject> Error = isolate->error_function();
   Handle<String> name =
@@ -4175,7 +4173,9 @@ bool Genesis::InstallSpecialObjects(Handle<Context> native_context) {
   Handle<Smi> stack_trace_limit(Smi::FromInt(FLAG_stack_trace_limit), isolate);
   JSObject::AddProperty(Error, name, stack_trace_limit, NONE);
 
-  WasmJs::Install(isolate, global);
+  if (FLAG_expose_wasm || FLAG_validate_asm) {
+    WasmJs::Install(isolate);
+  }
 
   return true;
 }

src/wasm/wasm-js.h

@@ -13,16 +13,7 @@ namespace internal {
 // Exposes a WASM API to JavaScript through the V8 API.
 class WasmJs {
  public:
-  static void Install(Isolate* isolate, Handle<JSGlobalObject> global_object);
-
-  V8_EXPORT_PRIVATE static void InstallWasmModuleSymbolIfNeeded(
-      Isolate* isolate, Handle<JSGlobalObject> global, Handle<Context> context);
-
-  V8_EXPORT_PRIVATE static void InstallWasmMapsIfNeeded(
-      Isolate* isolate, Handle<Context> context);
-  static void InstallWasmConstructors(Isolate* isolate,
-                                      Handle<JSGlobalObject> global,
-                                      Handle<Context> context);
+  V8_EXPORT_PRIVATE static void Install(Isolate* isolate);
 
   // WebAssembly.Table.
   static bool IsWasmTableObject(Isolate* isolate, Handle<Object> value);

src/wasm/wasm-module.h

@@ -398,6 +398,8 @@ V8_EXPORT_PRIVATE MaybeHandle<WasmModuleObject> CreateModuleObjectFromBytes(
 
 V8_EXPORT_PRIVATE Handle<JSArray> GetImports(Isolate* isolate,
                                              Handle<WasmModuleObject> module);
+V8_EXPORT_PRIVATE Handle<JSArray> GetExports(Isolate* isolate,
+                                             Handle<WasmModuleObject> module);
 
 V8_EXPORT_PRIVATE Handle<JSArray> GetExports(Isolate* isolate,
                                              Handle<WasmModuleObject> module);

src/wasm/wasm-objects.cc

@@ -292,12 +292,15 @@ bool WasmInstanceObject::IsWasmInstanceObject(Object* object) {
 
 Handle<WasmInstanceObject> WasmInstanceObject::New(
     Isolate* isolate, Handle<WasmCompiledModule> compiled_module) {
-  Handle<Map> map = isolate->factory()->NewMap(
-      JS_OBJECT_TYPE, JSObject::kHeaderSize + kFieldCount * kPointerSize);
+  Handle<JSFunction> instance_cons(
+      isolate->native_context()->wasm_instance_constructor());
+  Handle<JSObject> instance_object =
+      isolate->factory()->NewJSObject(instance_cons, TENURED);
+  Handle<Symbol> instance_sym(isolate->native_context()->wasm_instance_sym());
+  Object::SetProperty(instance_object, instance_sym, instance_object, STRICT)
+      .Check();
   Handle<WasmInstanceObject> instance(
-      reinterpret_cast<WasmInstanceObject*>(
-          *isolate->factory()->NewJSObjectFromMap(map, TENURED)),
-      isolate);
+      reinterpret_cast<WasmInstanceObject*>(*instance_object), isolate);
 
   instance->SetInternalField(kCompiledModule, *compiled_module);
   instance->SetInternalField(kMemoryObject, isolate->heap()->undefined_value());

test/cctest/wasm/wasm-run-utils.h

@@ -85,6 +85,7 @@ class TestingModule : public ModuleEnv {
                                               Vector<const byte>::empty()),
                                zone->allocator())
                          : nullptr) {
+    WasmJs::Install(isolate_);
     instance->module = &module_;
     instance->globals_start = global_data;
     module_.globals_size = kMaxGlobalsSize;
@@ -223,7 +224,6 @@ class TestingModule : public ModuleEnv {
     // Wrap the code so it can be called as a JS function.
     Handle<WasmInstanceObject> instance_obj(0, isolate_);
     Handle<Code> code = instance->function_code[index];
-    WasmJs::InstallWasmMapsIfNeeded(isolate_, isolate_->native_context());
     Handle<Code> ret_code =
         compiler::CompileJSToWasmWrapper(isolate_, &module_, code, index);
     Handle<JSFunction> ret = WasmExportedFunction::New(

test/common/wasm/wasm-module-runner.cc

@@ -205,9 +205,7 @@ int32_t CallWasmFunctionForTesting(Isolate* isolate, Handle<JSObject> instance,
 }
 
 void SetupIsolateForWasmModule(Isolate* isolate) {
-  WasmJs::InstallWasmMapsIfNeeded(isolate, isolate->native_context());
-  WasmJs::InstallWasmModuleSymbolIfNeeded(isolate, isolate->global_object(),
-                                          isolate->native_context());
+  WasmJs::Install(isolate);
 }
 }  // namespace testing
 }  // namespace wasm

test/mjsunit/wasm/js-api.js

@@ -134,8 +134,8 @@ assertErrorMessage(() => new Module(), TypeError, /requires more than 0 argument
 assertErrorMessage(() => new Module(undefined), TypeError, "first argument must be an ArrayBuffer or typed array object");
 assertErrorMessage(() => new Module(1), TypeError, "first argument must be an ArrayBuffer or typed array object");
 assertErrorMessage(() => new Module({}), TypeError, "first argument must be an ArrayBuffer or typed array object");
-//TODO assertErrorMessage(() => new Module(new Uint8Array()), CompileError, /failed to match magic number/);
-//TODO assertErrorMessage(() => new Module(new ArrayBuffer()), CompileError, /failed to match magic number/);
+assertErrorMessage(() => new Module(new Uint8Array()), CompileError, /failed to match magic number/);
+assertErrorMessage(() => new Module(new ArrayBuffer()), CompileError, /failed to match magic number/);
 assertEq(new Module(emptyModuleBinary) instanceof Module, true);
 assertEq(new Module(emptyModuleBinary.buffer) instanceof Module, true);
 
@@ -259,9 +259,9 @@ assertEq(Instance.name, "Instance");
 assertErrorMessage(() => Instance(), TypeError, /constructor without new is forbidden/);
 assertErrorMessage(() => new Instance(1), TypeError, "first argument must be a WebAssembly.Module");
 assertErrorMessage(() => new Instance({}), TypeError, "first argument must be a WebAssembly.Module");
-//TODO assertErrorMessage(() => new Instance(emptyModule, null), TypeError, "second argument must be an object");
-//TODO assertEq(new Instance(emptyModule) instanceof Instance, true);
-//TODO assertEq(new Instance(emptyModule, {}) instanceof Instance, true);
+assertErrorMessage(() => new Instance(emptyModule, null), TypeError, "second argument must be an object");
+assertEq(new Instance(emptyModule) instanceof Instance, true);
+assertEq(new Instance(emptyModule, {}) instanceof Instance, true);
 
 // 'WebAssembly.Instance.prototype' data property
 let instanceProtoDesc = Object.getOwnPropertyDescriptor(Instance, 'prototype');