dart-sdk/tests/language/optimize/pure_function_test.dart
Robert Nystrom c959c9aba7 Migrate language_2/optimize to NNBD.
Change-Id: I3f67dd79ff2ee745cc2ea161ce7150630e805c97
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150186
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
2020-06-06 01:42:35 +00:00

37 lines
1.1 KiB
Dart

// Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import "package:expect/expect.dart";
// Regression test for issue 17483.
class A {
var x, y;
A(x, this.y) {
this.x = x;
}
toString() => "a";
}
foo(trace) => trace.add("foo");
bar(trace) => trace.add("bar");
main() {
var trace = [];
// Dart2js must keep the order of t1 and t2.
var t1 = foo(trace);
var t2 = bar(trace);
// Dart2js inlines the constructor, yielding something like:
// t3 = jsNew A(null, t2); // Note that jsNew is pure.
// t3.x = t1;
// t3 is used twice and cannot be generated at use site.
// Dart2js must not allow t1 to cross the t3-line.
var a = new A(t1, t2);
// Use a. It is already implicitly used by the this.x = x line in its
// constructor. With the following use we use it twice and make sure that
// the allocation can not be generated at use-site.
trace.add(a.toString());
Expect.listEquals(["foo", "bar", "a"], trace);
}