49 lines
1.2 KiB
JavaScript
49 lines
1.2 KiB
JavaScript
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// Copyright 2015 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Flags: --allow-natives-syntax --expose-gc
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function Inner() {
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this.p1 = 0;
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this.p2 = 3;
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}
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function Outer() {
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this.p3 = 0;
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}
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var i1 = new Inner();
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var i2 = new Inner();
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var o1 = new Outer();
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o1.inner = i1;
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// o1.map now thinks "inner" has type Inner.map1.
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// Deprecate Inner.map1:
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i1.p1 = 0.5;
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// Let Inner.map1 die by migrating i2 to Inner.map2:
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print(i2.p1);
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gc();
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// o1.map's descriptor for "inner" is now a cleared WeakCell;
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// o1.inner's actual map is Inner.map2.
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// Prepare Inner.map3, deprecating Inner.map2.
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i2.p2 = 0.5;
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// Deprecate o1's map.
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var o2 = new Outer();
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o2.p3 = 0.5;
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o2.inner = i2;
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// o2.map (Outer.map2) now says that o2.inner's type is Inner.map3.
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// Migrate o1 to Outer.map2.
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print(o1.p3);
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// o1.map now thinks that o1.inner has map Inner.map3 just like o2.inner,
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// but in fact o1.inner.map is still Inner.map2!
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function loader(o) {
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return o.inner.p2;
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}
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loader(o2);
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loader(o2);
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%OptimizeFunctionOnNextCall(loader);
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assertEquals(0.5, loader(o2));
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assertEquals(3, loader(o1));
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gc(); // Crashes with --verify-heap.
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