v8/test/debugger/debug/lazy-deopt-then-flush-bytecode.js
Ross McIlroy 3cdee40e59 [Compiler] Ensure JSFunction is reset if bytecode was flushed before trying to deoptimize it.
BUG=v8:8395

Change-Id: I6e4c7550d71f4fe8b4df36a0a5794f89bf94d70a
Reviewed-on: https://chromium-review.googlesource.com/c/1373774
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58216}
2018-12-13 12:27:20 +00:00

49 lines
1.5 KiB
JavaScript

// Copyright 2018 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 --opt --noalways-opt --stress-flush-bytecode
// Flags: --expose-gc
Debug = debug.Debug
function foo() {
return 44;
}
function listener(event, exec_state, event_data, data) {
if (event != Debug.DebugEvent.Break) return;
// Optimize foo.
%OptimizeFunctionOnNextCall(foo);
foo();
assertOptimized(foo);
// Lazily deopt foo, which marks the code for deoptimization and invalidates
// the DeoptimizationData, but doesn't unlink the optimized code entry in
// foo's JSFunction.
%DeoptimizeFunction(foo);
// Run the GC. Since the DeoptimizationData is now dead, the bytecode
// associated with the optimized code is free to be flushed, which also
// free's the feedback vector meta-data.
gc();
// Execute foo with side-effect checks, which causes the debugger to call
// DeoptimizeFunction on foo. Even though the code is already marked for
// deoptimization, this will try to unlink the optimized code from the
// feedback vector, which will fail due to the feedback meta-data being
// flushed. The deoptimizer should call JSFunction::ResetIfBytecodeFlushed
// before trying to do this, which will clear the whole feedback vector and
// reset the JSFunction's code entry field to CompileLazy.
exec_state.frame(0).evaluate("foo()", true);
}
// Add the debug event listener.
Debug.setListener(listener);
function f() {
debugger;
}
f();