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- /*
- * Copyright 2013-present Facebook, Inc.
- *
- * 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
- *
- * http://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.
- */
- #pragma once
- #include <exception>
- #if !defined(FOLLY_FORCE_EXCEPTION_COUNT_USE_STD) && \
- (defined(__GNUG__) || defined(__clang__))
- #define FOLLY_EXCEPTION_COUNT_USE_CXA_GET_GLOBALS
- namespace __cxxabiv1 {
- // forward declaration (originally defined in unwind-cxx.h from from libstdc++)
- struct __cxa_eh_globals;
- // declared in cxxabi.h from libstdc++-v3
- extern "C" __cxa_eh_globals* __cxa_get_globals() noexcept;
- } // namespace __cxxabiv1
- #elif defined(_MSC_VER) && (_MSC_VER >= 1400) && \
- (_MSC_VER < 1900) // MSVC++ 8.0 or greater
- #define FOLLY_EXCEPTION_COUNT_USE_GETPTD
- // forward declaration (originally defined in mtdll.h from MSVCRT)
- struct _tiddata;
- extern "C" _tiddata* _getptd(); // declared in mtdll.h from MSVCRT
- #elif defined(FOLLY_FORCE_EXCEPTION_COUNT_USE_STD) || \
- (defined(_MSC_VER) && (_MSC_VER >= 1900)) // MSVC++ 2015
- #define FOLLY_EXCEPTION_COUNT_USE_STD
- #else
- // Raise an error when trying to use this on unsupported platforms.
- #error "Unsupported platform, don't include this header."
- #endif
- namespace folly {
- /**
- * Returns the number of uncaught exceptions.
- *
- * This function is based on Evgeny Panasyuk's implementation from here:
- * http://fburl.com/15190026
- */
- inline int uncaught_exceptions() noexcept {
- #if defined(FOLLY_EXCEPTION_COUNT_USE_CXA_GET_GLOBALS)
- // __cxa_get_globals returns a __cxa_eh_globals* (defined in unwind-cxx.h).
- // The offset below returns __cxa_eh_globals::uncaughtExceptions.
- return *(reinterpret_cast<unsigned int*>(
- static_cast<char*>(static_cast<void*>(__cxxabiv1::__cxa_get_globals())) +
- sizeof(void*)));
- #elif defined(FOLLY_EXCEPTION_COUNT_USE_GETPTD)
- // _getptd() returns a _tiddata* (defined in mtdll.h).
- // The offset below returns _tiddata::_ProcessingThrow.
- return *(reinterpret_cast<int*>(
- static_cast<char*>(static_cast<void*>(_getptd())) + sizeof(void*) * 28 +
- 0x4 * 8));
- #elif defined(FOLLY_EXCEPTION_COUNT_USE_STD)
- return std::uncaught_exceptions();
- #endif
- }
- } // namespace folly
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