ecency-mobile/ios/Pods/Folly/folly/detail/UncaughtExceptionCounter.h

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/*
* Copyright 2016 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(__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;
}
#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(_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 { namespace detail {
/**
* Used to check if a new uncaught exception was thrown by monitoring the
* number of uncaught exceptions.
*
* Usage:
* - create a new UncaughtExceptionCounter object
* - call isNewUncaughtException() on the new object to check if a new
* uncaught exception was thrown since the object was created
*/
class UncaughtExceptionCounter {
public:
UncaughtExceptionCounter() noexcept
: exceptionCount_(getUncaughtExceptionCount()) {}
UncaughtExceptionCounter(const UncaughtExceptionCounter& other) noexcept
: exceptionCount_(other.exceptionCount_) {}
bool isNewUncaughtException() noexcept {
return getUncaughtExceptionCount() > exceptionCount_;
}
private:
int getUncaughtExceptionCount() noexcept;
int exceptionCount_;
};
/**
* Returns the number of uncaught exceptions.
*
* This function is based on Evgeny Panasyuk's implementation from here:
* http://fburl.com/15190026
*/
inline int UncaughtExceptionCounter::getUncaughtExceptionCount() 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
}
}} // namespaces