[wasm] instantiate expressed in terms of compile

Today, the semantics of:

WebAssembly.instantiate

and

WebAssembly.compile().then(new WebAssemblyInstance)

are subtly different, to the point where attempting the proposed
change uncovered bugs.

In the future, it's possible that .instantiate actually have different
semantics - if we pre-specialized to the provided ffi, for example.
Right now that's not the case.

This CL:
- gets our implementation closer to what developers may write using
the compile -> new Instance alternative, in particular wrt promise
creation. By reusing code paths, we uncover more bugs, and keep
maintenance cost lower.

- it gives us the response-based WebAssembly.instantiate implicitly.
Otherwise, we'd need that same implementation on the blink side. The
negative is maintenance: imagine if the bugs I mentioned could only be
found when running in Blink.

BUG=chromium:697028

Review-Url: https://codereview.chromium.org/2806073002
Cr-Commit-Position: refs/heads/master@{#44592}
This commit is contained in:
mtrofin 2017-04-11 17:01:04 -07:00 committed by Commit bot
parent 70ad23791a
commit 7829af3275
8 changed files with 193 additions and 90 deletions

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@ -111,6 +111,15 @@ bool WasmInstantiateOverride(const v8::FunctionCallbackInfo<v8::Value>& args) {
return true;
}
bool GetWasmFromResolvedPromise(
const v8::FunctionCallbackInfo<v8::Value>& args) {
CHECK(args.Length() == 1);
v8::Local<v8::Promise> promise = v8::Local<v8::Promise>::Cast(args[0]);
CHECK(promise->State() == v8::Promise::PromiseState::kFulfilled);
args.GetReturnValue().Set(promise);
return true;
}
} // namespace
namespace v8 {
@ -445,6 +454,24 @@ RUNTIME_FUNCTION(Runtime_ClearFunctionFeedback) {
return isolate->heap()->undefined_value();
}
RUNTIME_FUNCTION(Runtime_SetWasmCompileFromPromiseOverload) {
v8::ExtensionCallback old = isolate->wasm_compile_callback();
HandleScope scope(isolate);
Handle<Foreign> ret =
isolate->factory()->NewForeign(reinterpret_cast<Address>(old));
isolate->set_wasm_compile_callback(GetWasmFromResolvedPromise);
return *ret;
}
RUNTIME_FUNCTION(Runtime_ResetWasmOverloads) {
HandleScope scope(isolate);
DCHECK_EQ(1, args.length());
CONVERT_ARG_HANDLE_CHECKED(Foreign, old, 0);
isolate->set_wasm_compile_callback(
reinterpret_cast<v8::ExtensionCallback>(old->foreign_address()));
return isolate->heap()->undefined_value();
}
RUNTIME_FUNCTION(Runtime_CheckWasmWrapperElision) {
// This only supports the case where the function being exported
// calls an intermediate function, and the intermediate function

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@ -616,6 +616,8 @@ namespace internal {
F(ValidateWasmOrphanedInstance, 1, 1) \
F(SetWasmCompileControls, 2, 1) \
F(SetWasmInstantiateControls, 0, 1) \
F(SetWasmCompileFromPromiseOverload, 0, 1) \
F(ResetWasmOverloads, 1, 1) \
F(HeapObjectVerify, 1, 1) \
F(WasmNumInterpretedCalls, 1, 1) \
F(RedirectToWasmInterpreter, 2, 1)

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@ -32,6 +32,18 @@ namespace v8 {
namespace {
#define ASSIGN(type, var, expr) \
Local<type> var; \
do { \
if (!expr.ToLocal(&var)) return; \
} while (false)
#define DO_BOOL(expr) \
do { \
bool ok; \
if (!expr.To(&ok) || !ok) return; \
} while (false)
// TODO(wasm): move brand check to the respective types, and don't throw
// in it, rather, use a provided ErrorThrower, or let caller handle it.
static bool HasBrand(i::Handle<i::Object> value, i::Handle<i::Symbol> sym) {
@ -117,16 +129,15 @@ i::wasm::ModuleWireBytes GetFirstArgumentAsBytes(
return i::wasm::ModuleWireBytes(start, start + length);
}
i::MaybeHandle<i::JSReceiver> GetSecondArgumentAsImports(
const v8::FunctionCallbackInfo<v8::Value>& args, ErrorThrower* thrower) {
if (args.Length() < 2) return {};
if (args[1]->IsUndefined()) return {};
i::MaybeHandle<i::JSReceiver> GetValueAsImports(const Local<Value>& arg,
ErrorThrower* thrower) {
if (arg->IsUndefined()) return {};
if (!args[1]->IsObject()) {
if (!arg->IsObject()) {
thrower->TypeError("Argument 1 must be an object");
return {};
}
Local<Object> obj = Local<Object>::Cast(args[1]);
Local<Object> obj = Local<Object>::Cast(arg);
return i::Handle<i::JSReceiver>::cast(v8::Utils::OpenHandle(*obj));
}
@ -140,8 +151,7 @@ void WebAssemblyCompile(const v8::FunctionCallbackInfo<v8::Value>& args) {
ErrorThrower thrower(i_isolate, "WebAssembly.compile()");
Local<Context> context = isolate->GetCurrentContext();
v8::Local<v8::Promise::Resolver> resolver;
if (!v8::Promise::Resolver::New(context).ToLocal(&resolver)) return;
ASSIGN(Promise::Resolver, resolver, Promise::Resolver::New(context));
v8::ReturnValue<v8::Value> return_value = args.GetReturnValue();
return_value.Set(resolver->GetPromise());
@ -253,10 +263,70 @@ void WebAssemblyModuleCustomSections(
args.GetReturnValue().Set(Utils::ToLocal(custom_sections));
}
// Entered as internal implementation detail of sync and async instantiate.
// args[0] *must* be a WebAssembly.Module.
void WebAssemblyInstantiateImpl(
const v8::FunctionCallbackInfo<v8::Value>& args) {
DCHECK_GE(args.Length(), 1);
Local<Value> module = args[0];
Local<Value> ffi = args.Data();
HandleScope scope(args.GetIsolate());
v8::Isolate* isolate = args.GetIsolate();
i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
ErrorThrower thrower(i_isolate, "WebAssembly Instantiation");
i::MaybeHandle<i::JSReceiver> maybe_imports =
GetValueAsImports(ffi, &thrower);
if (thrower.error()) return;
i::Handle<i::WasmModuleObject> module_obj =
i::Handle<i::WasmModuleObject>::cast(
Utils::OpenHandle(Object::Cast(*module)));
i::MaybeHandle<i::Object> instance_object =
i::wasm::SyncInstantiate(i_isolate, &thrower, module_obj, maybe_imports,
i::MaybeHandle<i::JSArrayBuffer>());
if (instance_object.is_null()) {
// TODO(wasm): this *should* mean there's an error to throw, but
// we exit sometimes the instantiation pipeline without throwing.
// v8:6232.
return;
}
args.GetReturnValue().Set(Utils::ToLocal(instance_object.ToHandleChecked()));
}
void WebAssemblyInstantiateToPair(
const v8::FunctionCallbackInfo<v8::Value>& args) {
DCHECK_GE(args.Length(), 1);
Local<Value> module = args[0];
Isolate* isolate = args.GetIsolate();
Local<Context> context = isolate->GetCurrentContext();
const uint8_t* instance_str = reinterpret_cast<const uint8_t*>("instance");
const uint8_t* module_str = reinterpret_cast<const uint8_t*>("module");
ASSIGN(Function, vanilla_instantiate,
Function::New(context, WebAssemblyInstantiateImpl, args.Data()));
ASSIGN(Value, instance,
vanilla_instantiate->Call(context, args.Holder(), 1, &module));
Local<Object> ret = Object::New(isolate);
ASSIGN(String, instance_name,
String::NewFromOneByte(isolate, instance_str,
NewStringType::kInternalized));
ASSIGN(String, module_name,
String::NewFromOneByte(isolate, module_str,
NewStringType::kInternalized));
DO_BOOL(ret->CreateDataProperty(context, instance_name, instance));
DO_BOOL(ret->CreateDataProperty(context, module_name, module));
args.GetReturnValue().Set(ret);
}
// new WebAssembly.Instance(module, imports) -> WebAssembly.Instance
void WebAssemblyInstance(const v8::FunctionCallbackInfo<v8::Value>& args) {
HandleScope scope(args.GetIsolate());
v8::Isolate* isolate = args.GetIsolate();
Isolate* isolate = args.GetIsolate();
Local<Context> context = isolate->GetCurrentContext();
i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
if (i_isolate->wasm_instance_callback()(args)) return;
@ -265,14 +335,15 @@ void WebAssemblyInstance(const v8::FunctionCallbackInfo<v8::Value>& args) {
auto maybe_module = GetFirstArgumentAsModule(args, &thrower);
if (thrower.error()) return;
auto maybe_imports = GetSecondArgumentAsImports(args, &thrower);
if (thrower.error()) return;
// If args.Length < 2, this will be undefined - see FunctionCallbackInfo.
// We'll check for that in WebAssemblyInstantiateImpl.
Local<Value> data = args[1];
i::MaybeHandle<i::Object> instance_object = i::wasm::SyncInstantiate(
i_isolate, &thrower, maybe_module.ToHandleChecked(), maybe_imports,
i::MaybeHandle<i::JSArrayBuffer>());
if (instance_object.is_null()) return;
args.GetReturnValue().Set(Utils::ToLocal(instance_object.ToHandleChecked()));
ASSIGN(Function, impl,
Function::New(context, WebAssemblyInstantiateImpl, data));
Local<Value> first_param = args[0];
ASSIGN(Value, ret, impl->Call(context, args.Holder(), 1, &first_param));
args.GetReturnValue().Set(ret);
}
// WebAssembly.instantiate(module, imports) -> WebAssembly.Instance
@ -290,10 +361,9 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
Local<Context> context = isolate->GetCurrentContext();
i::Handle<i::Context> i_context = Utils::OpenHandle(*context);
v8::Local<v8::Promise::Resolver> resolver;
if (!v8::Promise::Resolver::New(context).ToLocal(&resolver)) return;
v8::ReturnValue<v8::Value> return_value = args.GetReturnValue();
return_value.Set(resolver->GetPromise());
ASSIGN(Promise::Resolver, resolver, Promise::Resolver::New(context));
Local<Promise> module_promise = resolver->GetPromise();
args.GetReturnValue().Set(module_promise);
if (args.Length() < 1) {
thrower.TypeError(
@ -305,7 +375,8 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
return;
}
i::Handle<i::Object> first_arg = Utils::OpenHandle(*args[0]);
Local<Value> first_arg_value = args[0];
i::Handle<i::Object> first_arg = Utils::OpenHandle(*first_arg_value);
if (!first_arg->IsJSObject()) {
thrower.TypeError(
"Argument 0 must be a buffer source or a WebAssembly.Module object");
@ -315,31 +386,27 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
return;
}
auto maybe_imports = GetSecondArgumentAsImports(args, &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::Handle<i::JSPromise> promise = Utils::OpenHandle(*resolver->GetPromise());
FunctionCallback instantiator = nullptr;
if (HasBrand(first_arg, i::Handle<i::Symbol>(i_context->wasm_module_sym()))) {
// WebAssembly.instantiate(module, imports) -> WebAssembly.Instance
auto module_object = GetFirstArgumentAsModule(args, &thrower);
i::wasm::AsyncInstantiate(i_isolate, promise,
module_object.ToHandleChecked(), maybe_imports);
module_promise = resolver->GetPromise();
DO_BOOL(resolver->Resolve(context, first_arg_value));
instantiator = WebAssemblyInstantiateImpl;
} else {
// WebAssembly.instantiate(bytes, imports) -> {module, instance}
auto bytes = GetFirstArgumentAsBytes(args, &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::AsyncCompileAndInstantiate(i_isolate, promise, bytes,
maybe_imports);
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 = WebAssemblyInstantiateToPair;
}
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];
ASSIGN(Function, instantiate_impl,
Function::New(context, instantiator, data));
ASSIGN(Promise, result, module_promise->Then(context, instantiate_impl));
args.GetReturnValue().Set(result);
}
bool GetIntegerProperty(v8::Isolate* isolate, ErrorThrower* thrower,

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@ -2604,44 +2604,6 @@ void wasm::AsyncInstantiate(Isolate* isolate, Handle<JSPromise> promise,
instance_object.ToHandleChecked());
}
void wasm::AsyncCompileAndInstantiate(Isolate* isolate,
Handle<JSPromise> promise,
const ModuleWireBytes& bytes,
MaybeHandle<JSReceiver> imports) {
ErrorThrower thrower(isolate, nullptr);
// Compile the module.
MaybeHandle<WasmModuleObject> module_object =
SyncCompile(isolate, &thrower, bytes);
if (thrower.error()) {
RejectPromise(isolate, handle(isolate->context()), &thrower, promise);
return;
}
Handle<WasmModuleObject> module = module_object.ToHandleChecked();
// Instantiate the module.
MaybeHandle<WasmInstanceObject> instance_object = SyncInstantiate(
isolate, &thrower, module, imports, Handle<JSArrayBuffer>::null());
if (thrower.error()) {
RejectPromise(isolate, handle(isolate->context()), &thrower, promise);
return;
}
Handle<JSFunction> object_function =
Handle<JSFunction>(isolate->native_context()->object_function(), isolate);
Handle<JSObject> ret =
isolate->factory()->NewJSObject(object_function, TENURED);
Handle<String> module_property_name =
isolate->factory()->InternalizeUtf8String("module");
Handle<String> instance_property_name =
isolate->factory()->InternalizeUtf8String("instance");
JSObject::AddProperty(ret, module_property_name, module, NONE);
JSObject::AddProperty(ret, instance_property_name,
instance_object.ToHandleChecked(), NONE);
ResolvePromise(isolate, handle(isolate->context()), promise, ret);
}
// Encapsulates all the state and steps of an asynchronous compilation.
// An asynchronous compile job consists of a number of tasks that are executed
// as foreground and background tasks. Any phase that touches the V8 heap or

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@ -472,10 +472,6 @@ V8_EXPORT_PRIVATE void AsyncInstantiate(Isolate* isolate,
Handle<WasmModuleObject> module_object,
MaybeHandle<JSReceiver> imports);
V8_EXPORT_PRIVATE void AsyncCompileAndInstantiate(
Isolate* isolate, Handle<JSPromise> promise, const ModuleWireBytes& bytes,
MaybeHandle<JSReceiver> imports);
#if V8_TARGET_ARCH_64_BIT
const bool kGuardRegionsSupported = true;
#else

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@ -2,19 +2,33 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --expose-wasm
// Flags: --allow-natives-syntax
load("test/mjsunit/wasm/wasm-constants.js");
load("test/mjsunit/wasm/wasm-module-builder.js");
(function BasicTest() {
var kReturnValue = 15;
const kReturnValue = 15;
function getBuilder() {
var builder = new WasmModuleBuilder();
builder.addFunction("main", kSig_i_i)
.addBody([kExprI32Const, kReturnValue])
.exportFunc();
return builder;
}
(function BasicTest() {
var builder = getBuilder();
var main = builder.instantiate().exports.main;
assertEquals(kReturnValue, main());
})();
(function AsyncTest() {
var builder = getBuilder();
var buffer = builder.toBuffer();
assertPromiseResult(
WebAssembly.instantiate(buffer)
.then(pair => pair.instance.exports.main(), assertUnreachable)
.then(result => assertEquals(kReturnValue, result), assertUnreachable));
})();

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@ -713,7 +713,6 @@ function assertCompileError(args, err, msg) {
var error = null;
assertPromiseResult(compile(...args), unexpectedSuccess, error => {
assertTrue(error instanceof err);
assertTrue(Boolean(error.stack.match('js-api.js')));
// TODO assertTrue(Boolean(error.message.match(msg)));
});
}
@ -760,7 +759,6 @@ function assertInstantiateError(args, err, msg) {
var error = null;
assertPromiseResult(instantiate(...args), unexpectedSuccess, error => {
assertTrue(error instanceof err);
assertTrue(Boolean(error.stack.match('js-api.js')));
// TODO assertTrue(Boolean(error.message.match(msg)));
});
}

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@ -0,0 +1,37 @@
// Copyright 2017 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.
// Flags: --allow-natives-syntax
load("test/mjsunit/wasm/wasm-constants.js");
load("test/mjsunit/wasm/wasm-module-builder.js");
let buffer = (() => {
let builder = new WasmModuleBuilder();
builder.addFunction("f", kSig_i_v)
.addBody([kExprI32Const, 42])
.exportAs("f");
return builder.toBuffer();
})();
var module = new WebAssembly.Module(buffer);
var wrapper = Promise.resolve(module);
assertPromiseResult(
WebAssembly.instantiate(wrapper),
assertUnreachable,
e => assertTrue(e instanceof TypeError));
assertPromiseResult((
() => {
var old = %SetWasmCompileFromPromiseOverload();
var ret = WebAssembly.instantiate(wrapper);
%ResetWasmOverloads(old);
return ret;
})(),
pair => {
assertTrue(pair.instance instanceof WebAssembly.Instance);
assertTrue(pair.module instanceof WebAssembly.Module)
},
assertUnreachable);