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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___EXCEPTION_EXCEPTION_H10#define _LIBCPP___EXCEPTION_EXCEPTION_H11 12#include <__config>13 14// <vcruntime_exception.h> defines its own std::exception and std::bad_exception types,15// which we use in order to be ABI-compatible with other STLs on Windows.16#if defined(_LIBCPP_ABI_VCRUNTIME)17# include <vcruntime_exception.h>18#endif19 20#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)21# pragma GCC system_header22#endif23 24_LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD25 26#if defined(_LIBCPP_ABI_VCRUNTIME) && (!defined(_HAS_EXCEPTIONS) || _HAS_EXCEPTIONS != 0)27// The std::exception class was already included above, but we're explicit about this condition here for clarity.28 29#elif defined(_LIBCPP_ABI_VCRUNTIME) && _HAS_EXCEPTIONS == 030// However, <vcruntime_exception.h> does not define std::exception and std::bad_exception31// when _HAS_EXCEPTIONS == 0.32//33// Since libc++ still wants to provide the std::exception hierarchy even when _HAS_EXCEPTIONS == 034// (after all those are simply types like any other), we define an ABI-compatible version35// of the VCRuntime std::exception and std::bad_exception types in that mode.36 37struct __std_exception_data {38 char const* _What;39 bool _DoFree;40};41 42class exception { // base of all library exceptions43public:44 exception() _NOEXCEPT : __data_() {}45 46 explicit exception(char const* __message) _NOEXCEPT : __data_() {47 __data_._What = __message;48 __data_._DoFree = true;49 }50 51 exception(exception const&) _NOEXCEPT : __data_() {}52 53 exception& operator=(exception const&) _NOEXCEPT { return *this; }54 55 virtual ~exception() _NOEXCEPT {}56 57 virtual char const* what() const _NOEXCEPT { return __data_._What ? __data_._What : "Unknown exception"; }58 59private:60 __std_exception_data __data_;61};62 63class bad_exception : public exception {64public:65 bad_exception() _NOEXCEPT : exception("bad exception") {}66};67 68#else // !defined(_LIBCPP_ABI_VCRUNTIME)69// On all other platforms, we define our own std::exception and std::bad_exception types70// regardless of whether exceptions are turned on as a language feature.71 72class _LIBCPP_EXPORTED_FROM_ABI exception {73public:74 _LIBCPP_HIDE_FROM_ABI exception() _NOEXCEPT {}75 _LIBCPP_HIDE_FROM_ABI exception(const exception&) _NOEXCEPT = default;76 _LIBCPP_HIDE_FROM_ABI exception& operator=(const exception&) _NOEXCEPT = default;77 78 virtual ~exception() _NOEXCEPT;79 virtual const char* what() const _NOEXCEPT;80};81 82class _LIBCPP_EXPORTED_FROM_ABI bad_exception : public exception {83public:84 _LIBCPP_HIDE_FROM_ABI bad_exception() _NOEXCEPT {}85 _LIBCPP_HIDE_FROM_ABI bad_exception(const bad_exception&) _NOEXCEPT = default;86 _LIBCPP_HIDE_FROM_ABI bad_exception& operator=(const bad_exception&) _NOEXCEPT = default;87 ~bad_exception() _NOEXCEPT override;88 const char* what() const _NOEXCEPT override;89};90#endif // !_LIBCPP_ABI_VCRUNTIME91 92_LIBCPP_END_UNVERSIONED_NAMESPACE_STD93 94#endif // _LIBCPP___EXCEPTION_EXCEPTION_H95