31 lines
796 B
JavaScript
31 lines
796 B
JavaScript
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// Copyright 2017 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 --opt --no-always-opt
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function foo(s) {
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return s[5];
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}
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assertEquals("f", foo("abcdef"));
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assertEquals(undefined, foo("a"));
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%OptimizeFunctionOnNextCall(foo);
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assertEquals("f", foo("abcdef"));
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assertEquals(undefined, foo("a"));
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assertOptimized(foo);
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// Now mess with the String.prototype.
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String.prototype.__proto__ = new Proxy(String.prototype.__proto__, {
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get(target, property) {
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return "5";
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}
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});
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assertEquals("f", foo("abcdef"));
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assertEquals("5", foo("a"));
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%OptimizeFunctionOnNextCall(foo);
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assertEquals("f", foo("abcdef"));
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assertEquals("5", foo("a"));
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assertOptimized(foo);
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