libcxx/include/__exception/exception_ptr.h

   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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
  10 #define _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
  11
  12 #include <__config>
  13 #include <__exception/operations.h>
  14 #include <__memory/addressof.h>
  15 #include <cstddef>
  16 #include <cstdlib>
  17
  18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19 #  pragma GCC system_header
  20 #endif
  21
  22 namespace std { // purposefully not using versioning namespace
  23
  24 #ifndef _LIBCPP_ABI_MICROSOFT
  25
  26 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
  27   void* __ptr_;
  28
  29 public:
  30   _LIBCPP_HIDE_FROM_ABI exception_ptr() _NOEXCEPT : __ptr_() {}
  31   _LIBCPP_HIDE_FROM_ABI exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
  32
  33   exception_ptr(const exception_ptr&) _NOEXCEPT;
  34   exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
  35   ~exception_ptr() _NOEXCEPT;
  36
  37   _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __ptr_ != nullptr; }
  38
  39   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
  40     return __x.__ptr_ == __y.__ptr_;
  41   }
  42
  43   friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
  44     return !(__x == __y);
  45   }
  46
  47   friend _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
  48   friend _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
  49 };
  50
  51 template <class _Ep>
  52 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
  53 #  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
  54   try {
  55     throw __e;
  56   } catch (...) {
  57     return current_exception();
  58   }
  59 #  else
  60   ((void)__e);
  61   std::abort();
  62 #  endif
  63 }
  64
  65 #else // _LIBCPP_ABI_MICROSOFT
  66
  67 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
  68   _LIBCPP_DIAGNOSTIC_PUSH
  69   _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")
  70   void* __ptr1_;
  71   void* __ptr2_;
  72   _LIBCPP_DIAGNOSTIC_POP
  73
  74 public:
  75   exception_ptr() _NOEXCEPT;
  76   exception_ptr(nullptr_t) _NOEXCEPT;
  77   exception_ptr(const exception_ptr& __other) _NOEXCEPT;
  78   exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
  79   exception_ptr& operator=(nullptr_t) _NOEXCEPT;
  80   ~exception_ptr() _NOEXCEPT;
  81   explicit operator bool() const _NOEXCEPT;
  82 };
  83
  84 _LIBCPP_EXPORTED_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
  85
  86 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
  87   return !(__x == __y);
  88 }
  89
  90 _LIBCPP_EXPORTED_FROM_ABI void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
  91
  92 _LIBCPP_EXPORTED_FROM_ABI exception_ptr __copy_exception_ptr(void* __except, const void* __ptr);
  93 _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
  94 _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
  95
  96 // This is a built-in template function which automagically extracts the required
  97 // information.
  98 template <class _E>
  99 void* __GetExceptionInfo(_E);
 100
 101 template <class _Ep>
 102 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
 103   return __copy_exception_ptr(std::addressof(__e), __GetExceptionInfo(__e));
 104 }
 105
 106 #endif // _LIBCPP_ABI_MICROSOFT
 107 } // namespace std
 108
 109 #endif // _LIBCPP___EXCEPTION_EXCEPTION_PTR_H