| /* |
| * Copyright 2017 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 { |
| |
| /** |
| * 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 |
| } |
| |
| } // namespaces |