v8/test/mjsunit/async-stack-traces-realms.js
Benedikt Meurer 2aa9474986 [dx] Support some cross-context async stack traces.
When passing promises from other contexts to an `await`, the
--harmony-await-optimization doesn't kick in, and as such the
promise will be wrapped in a "native promise" (from this context).
That means the promises aren't chained immediately, but delayed
via a PromiseResolveThenableJob, which chains these promises on
the next turn of this contexts' microtask queue.

If there's anything happening on the macro task queue in between
this and the point when an exception is raised, the chaining will
have happened and we actually find our way back via the promise
chains. And this CL adds support for exactly that case. For other
cases, it's currently impossible to reconstruct the async stack
unfortunately, but we hope that this will help with the major
use cases, where the developer awaits on I/O.

Bug: v8:7522, v8:8673, v8:9487
Ref: nodejs/node#28680
Change-Id: Icc06c7df12644c2d8d43b6c7580ee06bb8f1024a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1701847
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62709}
2019-07-15 11:57:32 +00:00

116 lines
3.0 KiB
JavaScript

// Copyright 2019 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 --async-stack-traces
// Basic test with an explicit throw.
(function() {
const realm = Realm.createAllowCrossRealmAccess();
async function one(x) {
await two(x);
}
const two = Realm.eval(realm, `(async function two(x) {
await x;
throw new Error();
})`);
async function test(f) {
try {
await f(new Promise(resolve => setTimeout(resolve)));
assertUnreachable();
} catch (e) {
assertInstanceof(e, Realm.global(realm).Error);
assertMatches(/Error.+at two.+at async one.+at async test/ms, e.stack);
}
}
assertPromiseResult((async () => {
%PrepareFunctionForOptimization(one);
%PrepareFunctionForOptimization(two);
await test(one);
await test(one);
%OptimizeFunctionOnNextCall(two);
await test(one);
%OptimizeFunctionOnNextCall(one);
await test(one);
Realm.dispose(realm);
})());
})();
// Basic test with an implicit throw (via ToNumber on Symbol).
(function() {
const realm = Realm.createAllowCrossRealmAccess();
async function one(x) {
return await two(x);
}
const two = Realm.eval(realm, `(async function two(x) {
await x;
return +Symbol(); // This will raise a TypeError.
})`);
async function test(f) {
try {
await f(new Promise(resolve => setTimeout(resolve)));
assertUnreachable();
} catch (e) {
assertInstanceof(e, Realm.global(realm).TypeError);
assertMatches(/TypeError.+at two.+at async one.+at async test/ms, e.stack);
}
}
assertPromiseResult((async() => {
%PrepareFunctionForOptimization(one);
%PrepareFunctionForOptimization(two);
await test(one);
await test(one);
%OptimizeFunctionOnNextCall(two);
await test(one);
%OptimizeFunctionOnNextCall(one);
await test(one);
Realm.dispose(realm);
})());
})();
// Basic test with async functions and promises chained via
// Promise.prototype.then(), which should still work following
// the generic chain upwards.
(function() {
const realm = Realm.createAllowCrossRealmAccess();
async function one(x) {
return await two(x).then(x => x);
}
const two = Realm.eval(realm, `(async function two(x) {
await x.then(x => x);
throw new Error();
})`);
async function test(f) {
try {
await f(new Promise(resolve => setTimeout(resolve)));
assertUnreachable();
} catch (e) {
assertInstanceof(e, Realm.global(realm).Error);
assertMatches(/Error.+at two.+at async one.+at async test/ms, e.stack);
}
}
assertPromiseResult((async() => {
%PrepareFunctionForOptimization(one);
%PrepareFunctionForOptimization(two);
await test(one);
await test(one);
%OptimizeFunctionOnNextCall(two);
await test(one);
%OptimizeFunctionOnNextCall(one);
await test(one);
Realm.dispose(realm);
})());
})();