v8/test/mjsunit/es6/iterator-call-lazy-deopt.js
Camillo Bruni e3e8ea5d65 [flags] Rename --opt to --turbofan
To be consistent with the all the other tiers and avoid confusion, we
rename --opt to ---turbofan, and --always-opt to --always-turbofan.

Change-Id: Ie23dc8282b3fb4cf2fbf73b6c3d5264de5d09718
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3610431
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80336}
2022-05-03 12:10:30 +00:00

67 lines
1.9 KiB
JavaScript

// Copyright 2022 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.
// The GetIterator bytecode is used to implement a part of the iterator
// protocol (https://tc39.es/ecma262/#sec-getiterator). Here, the
// bytecode performs multiple operations including some that have side-effects
// and may deoptimize eagerly or lazily.
// This test ensures the call @@iterator lazy deoptimization is handled correctly.
// Flags: --allow-natives-syntax --no-always-turbofan
let getIteratorCount = 0;
let iteratorCount = 0;
let iteratorAfterEagerDeoptCount = 0;
let triggerLazyDeopt = false;
function foo(obj) {
// The following for-of loop uses the iterator protocol to iterate
// over the 'obj'.
// The GetIterator bytecode involves 3 steps:
// 1. method = GetMethod(obj, @@iterator)
// 2. iterator = Call(method, obj).
// 3. if(!IsJSReceiver(iterator)) throw SymbolIteratorInvalid.
for (var x of obj) {
}
}
// The lazy deoptimization is triggerred by setting the
// 'triggerLazyDeopt' to true. And the lazy deopt should
// goto continuation to check the call result is JSReceiver.
var iterator =
function () {
if (triggerLazyDeopt) {
iteratorAfterEagerDeoptCount++;
%DeoptimizeFunction(foo);
// SymbolIteratorInvalid should be throwed.
return 1;
}
iteratorCount++;
return {
next: function () {
return { done: true };
}
}
}
let y = {
get [Symbol.iterator]() {
getIteratorCount++;
return iterator;
}
};
%PrepareFunctionForOptimization(foo);
foo(y);
foo(y);
%OptimizeFunctionOnNextCall(foo);
triggerLazyDeopt = true;
assertThrows(() => {
foo(y)
}, TypeError, "Result of the Symbol.iterator method is not an object")
assertUnoptimized(foo);
assertEquals(getIteratorCount, 3);
assertEquals(iteratorCount, 2);
assertEquals(iteratorAfterEagerDeoptCount, 1);