35 lines
1.1 KiB
JavaScript
35 lines
1.1 KiB
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
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function f() {
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function g(arg) { return arg; }
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// The closure contains a call IC slot.
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return function() { return g(42); };
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}
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const a = Realm.create();
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const b = Realm.create();
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// Create two closures in different contexts sharing the same
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// SharedFunctionInfo (shared due to code caching).
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const x = Realm.eval(a, f.toString() + " f()");
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const y = Realm.eval(b, f.toString() + " f()");
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// Run the first closure to create SFI::code.
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x();
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// At this point, SFI::code is set and `x` has a feedback vector (`y` does not).
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// Enabling block code coverage deoptimizes all functions and triggers the
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// buggy code path in which we'd unconditionally replace JSFunction::code with
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// its SFI::code (but skip feedback vector setup).
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%DebugToggleBlockCoverage(true);
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// Still no feedback vector set on `y` but it now contains code. Run it to
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// trigger the crash when attempting to write into the non-existent feedback
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// vector.
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y();
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