v8/test/mjsunit/regress/regress-5205.js

// Copyright 2016 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 --gc-global

(function TestGCDuringToObjectForWith() {
  function f(o) {
    if (o == 'warmup') { return g() }
    with (o) { return x }
  }
  %PrepareFunctionForOptimization(f);
  function g() {
    // Only a marker function serving as weak embedded object.
  }

  // Warm up 'f' so that weak embedded object 'g' will be used.
  f('warmup');
  f('warmup');
  g = null;

  // Test that 'f' behaves correctly unoptimized.
  assertEquals(23, f({ x:23 }));
  assertEquals(42, f({ x:42 }));

  // Test that 'f' behaves correctly optimized.
  %OptimizeFunctionOnNextCall(f);
  assertEquals(65, f({ x:65 }));

  // Test that 'f' behaves correctly on numbers.
  Number.prototype.x = 99;
  assertEquals(99, f(0));

  // Make sure the next [[ToObject]] allocation triggers GC. This in turn will
  // deoptimize 'f' because it has the weak embedded object 'g' in the code.
  %SetAllocationTimeout(1000, 1, false);
  assertEquals(99, f(0));
})();