Implement Instance instances correctly; fix a few error cases

src/wasm/wasm-js.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/asmjs/asm-js.h"
 #include "src/asmjs/asm-typer.h"
 #include "src/asmjs/asm-wasm-builder.h"
 #include "src/assert-scope.h"
@@ skipping 53 matching lines @@
     Local<TypedArray> array = Local<TypedArray>::Cast(source);
     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->TypeError("ArrayBuffer argument is empty");
+      thrower->CompileError("ArrayBuffer argument is empty");
     }
   } else {
     thrower->TypeError("Argument 0 must be an ArrayBuffer or Uint8Array");
   }
 
   return {start, end};
 }
 
 static i::MaybeHandle<i::WasmModuleObject> CreateModuleObject(
     v8::Isolate* isolate, const v8::Local<v8::Value> source,
@@ skipping 111 matching lines @@
     const v8::FunctionCallbackInfo<v8::Value>& args, ErrorThrower* thrower) {
   // It so happens that in both the WebAssembly.instantiate, as well as
   // WebAssembly.Instance ctor, the positions of the ffi object and memory
   // are the same. If that changes later, we refactor the consts into
   // parameters.
   static const int kFfiOffset = 1;
   static const int kMemOffset = 2;
 
   MaybeLocal<Value> nothing;
   i::Handle<i::JSReceiver> ffi = i::Handle<i::JSObject>::null();
-  if (args.Length() > kFfiOffset && args[kFfiOffset]->IsObject()) {
+  if (args.Length() > kFfiOffset && !args[kFfiOffset]->IsUndefined()) {
+    if (!args[kFfiOffset]->IsObject()) {
+      thrower->TypeError("Argument %d must be an object", kFfiOffset);
+      return nothing;
+    }
     Local<Object> obj = Local<Object>::Cast(args[kFfiOffset]);
     ffi = i::Handle<i::JSReceiver>::cast(v8::Utils::OpenHandle(*obj));
   }
 
   i::Handle<i::JSArrayBuffer> memory = i::Handle<i::JSArrayBuffer>::null();
-  if (args.Length() > kMemOffset && args[kMemOffset]->IsObject()) {
-    Local<Object> obj = Local<Object>::Cast(args[kMemOffset]);
-    i::Handle<i::Object> mem_obj = v8::Utils::OpenHandle(*obj);
-    if (i::WasmJs::IsWasmMemoryObject(i_isolate, mem_obj)) {
-      memory = i::Handle<i::JSArrayBuffer>(
-          i::Handle<i::WasmMemoryObject>::cast(mem_obj)->buffer(), i_isolate);
-    } else {
+  if (args.Length() > kMemOffset && !args[kMemOffset]->IsUndefined()) {
+    if (!args[kMemOffset]->IsObject()) {
       thrower->TypeError("Argument %d must be a WebAssembly.Memory",
                          kMemOffset);
       return nothing;
     }
+    Local<Object> obj = Local<Object>::Cast(args[kMemOffset]);
+    i::Handle<i::Object> mem_obj = v8::Utils::OpenHandle(*obj);
+    if (!i::WasmJs::IsWasmMemoryObject(i_isolate, mem_obj)) {
+      thrower->TypeError("Argument %d must be a WebAssembly.Memory",
+                         kMemOffset);
+      return nothing;
+    }
+    memory = i::Handle<i::JSArrayBuffer>(
+        i::Handle<i::WasmMemoryObject>::cast(mem_obj)->buffer(), i_isolate);
   }
   i::MaybeHandle<i::JSObject> instance = i::wasm::WasmModule::Instantiate(
       i_isolate, thrower, i_module_obj, ffi, memory);
   if (instance.is_null()) {
     if (!thrower->error())
       thrower->RuntimeError("Could not instantiate module");
     return nothing;
   }
   DCHECK(!i_isolate->has_pending_exception());
   return Utils::ToLocal(instance.ToHandleChecked());
@@ skipping 52 matching lines @@
   Local<Object> module_obj = Local<Object>::Cast(args[0]);
   i::Handle<i::WasmModuleObject> i_module_obj =
       i::Handle<i::WasmModuleObject>::cast(v8::Utils::OpenHandle(*module_obj));
 
   i::Handle<i::JSArray> exports = i::wasm::GetExports(i_isolate, i_module_obj);
 
   v8::ReturnValue<v8::Value> return_value = args.GetReturnValue();
   return_value.Set(Utils::ToLocal(exports));
 }
 
-void WebAssemblyInstanceCtor(const v8::FunctionCallbackInfo<v8::Value>& args) {
+void WebAssemblyInstance(const v8::FunctionCallbackInfo<v8::Value>& args) {
   HandleScope scope(args.GetIsolate());
   v8::Isolate* isolate = args.GetIsolate();
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
 
   ErrorThrower thrower(i_isolate, "WebAssembly.Instance()");
 
   if (args.Length() < 1) {
     thrower.TypeError("Argument 0 must be a WebAssembly.Module");
     return;
   }
@@ skipping 409 matching lines @@
   Handle<JSFunction> function =
       ApiNatives::InstantiateFunction(temp).ToHandleChecked();
   v8::PropertyAttribute attributes =
       static_cast<v8::PropertyAttribute>(v8::DontEnum);
   Utils::ToLocal(object)->SetAccessorProperty(Utils::ToLocal(name),
                                               Utils::ToLocal(function),
                                               Local<Function>(), attributes);
   return function;
 }
 
-void WasmJs::InstallWasmModuleSymbolIfNeeded(Isolate* isolate,
-                                             Handle<JSGlobalObject> global,
-                                             Handle<Context> context) {
-  if (!context->get(Context::WASM_MODULE_SYM_INDEX)->IsSymbol() ||
-      !context->get(Context::WASM_INSTANCE_SYM_INDEX)->IsSymbol()) {
-    InstallWasmMapsIfNeeded(isolate, isolate->native_context());
-    InstallWasmConstructors(isolate, isolate->global_object(),
-                            isolate->native_context());
-  }
-}
+void WasmJs::Install(Isolate* isolate) {
+  Handle<JSGlobalObject> global = isolate->global_object();
+  Handle<Context> context(global->native_context(), isolate);
+  // TODO(titzer): once FLAG_expose_wasm is gone, this should become a DCHECK.
+  if (context->get(Context::WASM_FUNCTION_MAP_INDEX)->IsMap()) return;
 
-void WasmJs::InstallWasmConstructors(Isolate* isolate,
-                                     Handle<JSGlobalObject> global,
-                                     Handle<Context> context) {
+  // Install Maps.
+
+  // TODO(titzer): Also make one for strict mode functions?
+  Handle<Map> prev_map = Handle<Map>(context->sloppy_function_map(), isolate);
+
+  InstanceType instance_type = prev_map->instance_type();
+  int internal_fields = JSObject::GetInternalFieldCount(*prev_map);
+  CHECK_EQ(0, internal_fields);
+  int pre_allocated =
+      prev_map->GetInObjectProperties() - prev_map->unused_property_fields();
+  int instance_size = 0;
+  int in_object_properties = 0;
+  int wasm_internal_fields = internal_fields + 1  // module instance object
+      + 1                  // function arity
+      + 1;                 // function signature
+  JSFunction::CalculateInstanceSizeHelper(instance_type, wasm_internal_fields,
+                                          0, &instance_size,
+                                          &in_object_properties);
+
+  int unused_property_fields = in_object_properties - pre_allocated;
+  Handle<Map> map = Map::CopyInitialMap(
+      prev_map, instance_size, in_object_properties, unused_property_fields);
+
+  context->set_wasm_function_map(*map);
+
+  // Install symbols.
+
   Factory* factory = isolate->factory();
   // Create private symbols.
   Handle<Symbol> module_sym = factory->NewPrivateSymbol();
   context->set_wasm_module_sym(*module_sym);
 
   Handle<Symbol> instance_sym = factory->NewPrivateSymbol();
   context->set_wasm_instance_sym(*instance_sym);
 
   Handle<Symbol> table_sym = factory->NewPrivateSymbol();
   context->set_wasm_table_sym(*table_sym);
 
   Handle<Symbol> memory_sym = factory->NewPrivateSymbol();
   context->set_wasm_memory_sym(*memory_sym);
 
-  // Bind the WebAssembly object.
+  // Install the JS API.
+
+  // Setup WebAssembly
   Handle<String> name = v8_str(isolate, "WebAssembly");
   Handle<JSFunction> cons = factory->NewFunction(name);
   JSFunction::SetInstancePrototype(
       cons, Handle<Object>(context->initial_object_prototype(), isolate));
   cons->shared()->set_instance_class_name(*name);
   Handle<JSObject> webassembly = factory->NewJSObject(cons, TENURED);
   PropertyAttributes attributes = static_cast<PropertyAttributes>(DONT_ENUM);
   JSObject::AddProperty(global, name, webassembly, attributes);
 
   // Setup compile
   InstallFunc(isolate, webassembly, "compile", WebAssemblyCompile, 1);
 
   // Setup validate
   InstallFunc(isolate, webassembly, "validate", WebAssemblyValidate, 1);
 
   // Setup instantiate
   InstallFunc(isolate, webassembly, "instantiate", WebAssemblyInstantiate, 1);
 
   // Setup Module
   Handle<JSFunction> module_constructor =
       InstallFunc(isolate, webassembly, "Module", WebAssemblyModule, 1);
   context->set_wasm_module_constructor(*module_constructor);
   Handle<JSObject> module_proto =
       factory->NewJSObject(module_constructor, TENURED);
-  i::Handle<i::Map> map = isolate->factory()->NewMap(
+  i::Handle<i::Map> module_map = isolate->factory()->NewMap(
       i::JS_OBJECT_TYPE, i::JSObject::kHeaderSize +
                              WasmModuleObject::kFieldCount * i::kPointerSize);
-  JSFunction::SetInitialMap(module_constructor, map, module_proto);
+  JSFunction::SetInitialMap(module_constructor, module_map, module_proto);
   JSObject::AddProperty(module_proto, isolate->factory()->constructor_string(),
                         module_constructor, DONT_ENUM);
   InstallFunc(isolate, module_constructor, "imports", WebAssemblyModuleImports,
               1);
   InstallFunc(isolate, module_constructor, "exports", WebAssemblyModuleExports,
               1);
 
   // Setup Instance
   Handle<JSFunction> instance_constructor =
-      InstallFunc(isolate, webassembly, "Instance", WebAssemblyInstanceCtor, 1);
+      InstallFunc(isolate, webassembly, "Instance", WebAssemblyInstance, 1);
   context->set_wasm_instance_constructor(*instance_constructor);
+  Handle<JSObject> instance_proto =
+      factory->NewJSObject(instance_constructor, TENURED);
+  i::Handle<i::Map> instance_map = isolate->factory()->NewMap(
+      i::JS_OBJECT_TYPE, i::JSObject::kHeaderSize +
+                             WasmInstanceObject::kFieldCount * i::kPointerSize);
+  JSFunction::SetInitialMap(instance_constructor, instance_map, instance_proto);
+  JSObject::AddProperty(instance_proto,
+                        isolate->factory()->constructor_string(),
+                        instance_constructor, DONT_ENUM);
 
   // Setup Table
   Handle<JSFunction> table_constructor =
       InstallFunc(isolate, webassembly, "Table", WebAssemblyTable, 1);
   context->set_wasm_table_constructor(*table_constructor);
   Handle<JSObject> table_proto =
       factory->NewJSObject(table_constructor, TENURED);
-  map = isolate->factory()->NewMap(
+  i::Handle<i::Map> table_map = isolate->factory()->NewMap(
       i::JS_OBJECT_TYPE, i::JSObject::kHeaderSize +
                              WasmTableObject::kFieldCount * i::kPointerSize);
-  JSFunction::SetInitialMap(table_constructor, map, table_proto);
+  JSFunction::SetInitialMap(table_constructor, table_map, table_proto);
   JSObject::AddProperty(table_proto, isolate->factory()->constructor_string(),
                         table_constructor, DONT_ENUM);
   InstallGetter(isolate, table_proto, "length", WebAssemblyTableGetLength);
   InstallFunc(isolate, table_proto, "grow", WebAssemblyTableGrow, 1);
   InstallFunc(isolate, table_proto, "get", WebAssemblyTableGet, 1);
   InstallFunc(isolate, table_proto, "set", WebAssemblyTableSet, 2);
 
   // Setup Memory
   Handle<JSFunction> memory_constructor =
       InstallFunc(isolate, webassembly, "Memory", WebAssemblyMemory, 1);
   context->set_wasm_memory_constructor(*memory_constructor);
   Handle<JSObject> memory_proto =
       factory->NewJSObject(memory_constructor, TENURED);
-  map = isolate->factory()->NewMap(
+  i::Handle<i::Map> memory_map = isolate->factory()->NewMap(
       i::JS_OBJECT_TYPE, i::JSObject::kHeaderSize +
                              WasmMemoryObject::kFieldCount * i::kPointerSize);
-  JSFunction::SetInitialMap(memory_constructor, map, memory_proto);
+  JSFunction::SetInitialMap(memory_constructor, memory_map, memory_proto);
   JSObject::AddProperty(memory_proto, isolate->factory()->constructor_string(),
                         memory_constructor, DONT_ENUM);
   InstallFunc(isolate, memory_proto, "grow", WebAssemblyMemoryGrow, 1);
   InstallGetter(isolate, memory_proto, "buffer", WebAssemblyMemoryGetBuffer);
 
   // Setup errors
   attributes = static_cast<PropertyAttributes>(DONT_ENUM);
   Handle<JSFunction> compile_error(
       isolate->native_context()->wasm_compile_error_function());
   JSObject::AddProperty(webassembly, isolate->factory()->CompileError_string(),
                         compile_error, attributes);
   Handle<JSFunction> link_error(
       isolate->native_context()->wasm_link_error_function());
   JSObject::AddProperty(webassembly, isolate->factory()->LinkError_string(),
                         link_error, attributes);
   Handle<JSFunction> runtime_error(
       isolate->native_context()->wasm_runtime_error_function());
   JSObject::AddProperty(webassembly, isolate->factory()->RuntimeError_string(),
                         runtime_error, attributes);
 }
 
-void WasmJs::Install(Isolate* isolate, Handle<JSGlobalObject> global) {
-  if (!FLAG_expose_wasm && !FLAG_validate_asm) {
-    return;
-  }
-
-  // Setup wasm function map.
-  Handle<Context> context(global->native_context(), isolate);
-  InstallWasmMapsIfNeeded(isolate, context);
-
-  if (FLAG_expose_wasm) {
-    InstallWasmConstructors(isolate, global, context);
-  }
-}
-
-void WasmJs::InstallWasmMapsIfNeeded(Isolate* isolate,
-                                     Handle<Context> context) {
-  if (!context->get(Context::WASM_FUNCTION_MAP_INDEX)->IsMap()) {
-    // TODO(titzer): Move this to bootstrapper.cc??
-    // TODO(titzer): Also make one for strict mode functions?
-    Handle<Map> prev_map = Handle<Map>(context->sloppy_function_map(), isolate);
-
-    InstanceType instance_type = prev_map->instance_type();
-    int internal_fields = JSObject::GetInternalFieldCount(*prev_map);
-    CHECK_EQ(0, internal_fields);
-    int pre_allocated =
-        prev_map->GetInObjectProperties() - prev_map->unused_property_fields();
-    int instance_size = 0;
-    int in_object_properties = 0;
-    int wasm_internal_fields = internal_fields + 1  // module instance object
-                               + 1                  // function arity
-                               + 1;                 // function signature
-    JSFunction::CalculateInstanceSizeHelper(instance_type, wasm_internal_fields,
-                                            0, &instance_size,
-                                            &in_object_properties);
-
-    int unused_property_fields = in_object_properties - pre_allocated;
-    Handle<Map> map = Map::CopyInitialMap(
-        prev_map, instance_size, in_object_properties, unused_property_fields);
-
-    context->set_wasm_function_map(*map);
-  }
-}
-
 static bool HasBrand(i::Handle<i::Object> value, i::Handle<i::Symbol> symbol) {
   if (value->IsJSObject()) {
     i::Handle<i::JSObject> object = i::Handle<i::JSObject>::cast(value);
     Maybe<bool> has_brand = i::JSObject::HasOwnProperty(object, symbol);
     if (has_brand.IsNothing()) return false;
     if (has_brand.ToChecked()) return true;
   }
   return false;
 }
 
 bool WasmJs::IsWasmMemoryObject(Isolate* isolate, Handle<Object> value) {
   i::Handle<i::Symbol> symbol(isolate->context()->wasm_memory_sym(), isolate);
   return HasBrand(value, symbol);
 }
 
 bool WasmJs::IsWasmTableObject(Isolate* isolate, Handle<Object> value) {
   i::Handle<i::Symbol> symbol(isolate->context()->wasm_table_sym(), isolate);
   return HasBrand(value, symbol);
 }
 }  // namespace internal
 }  // namespace v8