tvl-depot/absl/flags/flag.cc
Abseil Team 2796d500ae Export of internal Abseil changes
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b770d03c2f1042d399c3f9576e881691cbe962c4 by Abseil Team <absl-team@google.com>:

Avoid applying the workaround for MSVC's static initialization problems when using clang-cl.

PiperOrigin-RevId: 275870089

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2b8fc02ec49aeb5ad56cef20259cdd7f6ee0c917 by Abseil Team <absl-team@google.com>:

Document return values.

PiperOrigin-RevId: 275839042

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baa99064f9a28b188661df7fba989fcd558818af by Abseil Team <absl-team@google.com>:

Support "auto" and other uncommon builtin types in absl::debugging_internal::Demangle.

PiperOrigin-RevId: 275556195

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f9d5c6a3a0d374dbf105d6e2e9e0c8fa949ed187 by Gennadiy Rozental <rogeeff@google.com>:

Internal rework.

PiperOrigin-RevId: 275550005

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2679a77db5b26349e8c8b2059621af55d2fca139 by Mark Barolak <mbar@google.com>:

Remove a comment reference to the no longer extant ::string implementation.

PiperOrigin-RevId: 275531987

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7b427a7613c44a98c6f13da43b2bff2837ca6b19 by Derek Mauro <dmauro@google.com>:

Upgrade to Bazel 1.0.0 and CMake 3.15.4

PiperOrigin-RevId: 275500823

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81f7d20905debf9d1e300bd2e9899f88d27f632a by Derek Mauro <dmauro@google.com>:

Fix -Wimplicit-int-float-conversion warning in latest clang

PiperOrigin-RevId: 275492439
GitOrigin-RevId: b770d03c2f1042d399c3f9576e881691cbe962c4
Change-Id: I9b39dad524489f0d62c912d02e8ac43761c81e55
2019-10-21 14:35:27 -04:00

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1.8 KiB
C++

//
// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/flags/flag.h"
#include <cstring>
namespace absl {
// We want to validate the type mismatch between type definition and
// declaration. The lock-free implementation does not allow us to do it,
// so in debug builds we always use the slower implementation, which always
// validates the type.
#ifndef NDEBUG
#define ABSL_FLAGS_ATOMIC_GET(T) \
T GetFlag(const absl::Flag<T>& flag) { return flag.Get(); }
#else
#define ABSL_FLAGS_ATOMIC_GET(T) \
T GetFlag(const absl::Flag<T>& flag) { \
T result; \
if (flag.AtomicGet(&result)) { \
return result; \
} \
return flag.Get(); \
}
#endif
ABSL_FLAGS_INTERNAL_FOR_EACH_LOCK_FREE(ABSL_FLAGS_ATOMIC_GET)
#undef ABSL_FLAGS_ATOMIC_GET
// This global nutex protects on-demand construction of flag objects in MSVC
// builds.
#if defined(_MSC_VER) && !defined(__clang__)
namespace flags_internal {
ABSL_CONST_INIT static absl::Mutex construction_guard(absl::kConstInit);
absl::Mutex* GetGlobalConstructionGuard() { return &construction_guard; }
} // namespace flags_internal
#endif
} // namespace absl