f149912f33
Extend the effect of --freeze-flags-after-init to also protect updates
of individual flags instead of only the API.
For this, we wrap each flag in a {FlagValue} class which implicitly
converts to the value of the flag. Some cases still require the explicit
{value()} accessor though. That accessor is {constexpr}, in contrast to
the implicit conversion, because otherwise clang emits a lot of warnings
about dead code within "if (FLAG...)" scopes.
R=cbruni@chromium.org
Bug: v8:12887
Change-Id: I87d3457e49ceb317d34d6a21cf09c520d4171eb5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3683321
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80938}
37 lines
939 B
C++
37 lines
939 B
C++
// Copyright 2020 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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#ifndef V8_TEST_COMMON_FLAG_UTILS_H
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#define V8_TEST_COMMON_FLAG_UTILS_H
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#include "src/base/macros.h"
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#include "src/flags/flags.h"
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namespace v8 {
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namespace internal {
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template <typename T>
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class V8_NODISCARD FlagScope {
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public:
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FlagScope(FlagValue<T>* flag, T new_value)
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: flag_(flag), previous_value_(*flag) {
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*flag = new_value;
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}
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~FlagScope() { *flag_ = previous_value_; }
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private:
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FlagValue<T>* flag_;
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T previous_value_;
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};
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} // namespace internal
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} // namespace v8
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#define FLAG_VALUE_SCOPE(flag, value) \
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v8::internal::FlagScope<bool> UNIQUE_IDENTIFIER(__scope_##flag)( \
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&v8::internal::FLAG_##flag, value)
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#define FLAG_SCOPE(flag) FLAG_VALUE_SCOPE(flag, true)
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#endif // V8_TEST_COMMON_FLAG_UTILS_H
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