llvm-project/libcxx/include/exception

375 lines
11 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_EXCEPTION
#define _LIBCPP_EXCEPTION
/*
exception synopsis
namespace std
{
class exception
{
public:
exception() noexcept;
exception(const exception&) noexcept;
exception& operator=(const exception&) noexcept;
virtual ~exception() noexcept;
virtual const char* what() const noexcept;
};
class bad_exception
: public exception
{
public:
bad_exception() noexcept;
bad_exception(const bad_exception&) noexcept;
bad_exception& operator=(const bad_exception&) noexcept;
virtual ~bad_exception() noexcept;
virtual const char* what() const noexcept;
};
typedef void (*unexpected_handler)();
unexpected_handler set_unexpected(unexpected_handler f ) noexcept;
unexpected_handler get_unexpected() noexcept;
[[noreturn]] void unexpected();
typedef void (*terminate_handler)();
terminate_handler set_terminate(terminate_handler f ) noexcept;
terminate_handler get_terminate() noexcept;
[[noreturn]] void terminate() noexcept;
bool uncaught_exception() noexcept;
int uncaught_exceptions() noexcept; // C++17
typedef unspecified exception_ptr;
exception_ptr current_exception() noexcept;
void rethrow_exception [[noreturn]] (exception_ptr p);
template<class E> exception_ptr make_exception_ptr(E e) noexcept;
class nested_exception
{
public:
nested_exception() noexcept;
nested_exception(const nested_exception&) noexcept = default;
nested_exception& operator=(const nested_exception&) noexcept = default;
virtual ~nested_exception() = default;
// access functions
[[noreturn]] void rethrow_nested() const;
exception_ptr nested_ptr() const noexcept;
};
template <class T> [[noreturn]] void throw_with_nested(T&& t);
template <class E> void rethrow_if_nested(const E& e);
} // std
*/
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__config>
#include <__memory/addressof.h>
#include <cstddef>
#include <cstdlib>
#include <type_traits>
#include <version>
// <vcruntime_exception.h> defines its own std::exception and std::bad_exception types,
// which we use in order to be ABI-compatible with other STLs on Windows.
#if defined(_LIBCPP_ABI_VCRUNTIME)
# include <vcruntime_exception.h>
#endif
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
namespace std // purposefully not using versioning namespace
{
#if defined(_LIBCPP_ABI_VCRUNTIME) && (!defined(_HAS_EXCEPTIONS) || _HAS_EXCEPTIONS != 0)
// The std::exception class was already included above, but we're explicit about this condition here for clarity.
#elif defined(_LIBCPP_ABI_VCRUNTIME) && _HAS_EXCEPTIONS == 0
// However, <vcruntime_exception.h> does not define std::exception and std::bad_exception
// when _HAS_EXCEPTIONS == 0.
//
// Since libc++ still wants to provide the std::exception hierarchy even when _HAS_EXCEPTIONS == 0
// (after all those are simply types like any other), we define an ABI-compatible version
// of the VCRuntime std::exception and std::bad_exception types in that mode.
struct __std_exception_data {
char const* _What;
bool _DoFree;
};
class exception { // base of all library exceptions
public:
exception() _NOEXCEPT : _Data() {}
explicit exception(char const* __message) _NOEXCEPT : _Data() {
_Data._What = __message;
_Data._DoFree = true;
}
exception(exception const&) _NOEXCEPT {}
exception& operator=(exception const&) _NOEXCEPT { return *this; }
virtual ~exception() _NOEXCEPT {}
virtual char const* what() const _NOEXCEPT { return _Data._What ? _Data._What : "Unknown exception"; }
private:
__std_exception_data _Data;
};
class bad_exception : public exception {
public:
bad_exception() _NOEXCEPT : exception("bad exception") {}
};
#else // !defined(_LIBCPP_ABI_VCRUNTIME)
// On all other platforms, we define our own std::exception and std::bad_exception types
// regardless of whether exceptions are turned on as a language feature.
class _LIBCPP_EXCEPTION_ABI exception {
public:
_LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
_LIBCPP_INLINE_VISIBILITY exception(const exception&) _NOEXCEPT = default;
virtual ~exception() _NOEXCEPT;
virtual const char* what() const _NOEXCEPT;
};
class _LIBCPP_EXCEPTION_ABI bad_exception : public exception {
public:
_LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
virtual ~bad_exception() _NOEXCEPT;
virtual const char* what() const _NOEXCEPT;
};
#endif // !_LIBCPP_ABI_VCRUNTIME
#if _LIBCPP_STD_VER <= 14 \
|| defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
|| defined(_LIBCPP_BUILDING_LIBRARY)
typedef void (*unexpected_handler)();
_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
#endif
typedef void (*terminate_handler)();
_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
class _LIBCPP_TYPE_VIS exception_ptr;
_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
#ifndef _LIBCPP_ABI_MICROSOFT
class _LIBCPP_TYPE_VIS exception_ptr
{
void* __ptr_;
public:
_LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
_LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
exception_ptr(const exception_ptr&) _NOEXCEPT;
exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
~exception_ptr() _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY explicit operator bool() const _NOEXCEPT
{return __ptr_ != nullptr;}
friend _LIBCPP_INLINE_VISIBILITY
bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
{return __x.__ptr_ == __y.__ptr_;}
friend _LIBCPP_INLINE_VISIBILITY
bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
{return !(__x == __y);}
friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
};
template<class _Ep>
_LIBCPP_INLINE_VISIBILITY exception_ptr
make_exception_ptr(_Ep __e) _NOEXCEPT
{
#ifndef _LIBCPP_NO_EXCEPTIONS
try
{
throw __e;
}
catch (...)
{
return current_exception();
}
#else
((void)__e);
_VSTD::abort();
#endif
}
#else // _LIBCPP_ABI_MICROSOFT
class _LIBCPP_TYPE_VIS exception_ptr
{
_LIBCPP_DIAGNOSTIC_PUSH
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")
void* __ptr1_;
void* __ptr2_;
_LIBCPP_DIAGNOSTIC_POP
public:
exception_ptr() _NOEXCEPT;
exception_ptr(nullptr_t) _NOEXCEPT;
exception_ptr(const exception_ptr& __other) _NOEXCEPT;
exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
exception_ptr& operator=(nullptr_t) _NOEXCEPT;
~exception_ptr() _NOEXCEPT;
explicit operator bool() const _NOEXCEPT;
};
_LIBCPP_FUNC_VIS
bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
inline _LIBCPP_INLINE_VISIBILITY
bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
{return !(__x == __y);}
_LIBCPP_FUNC_VIS void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
_LIBCPP_FUNC_VIS exception_ptr __copy_exception_ptr(void *__except, const void* __ptr);
_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
// This is a built-in template function which automagically extracts the required
// information.
template <class _E> void *__GetExceptionInfo(_E);
template<class _Ep>
_LIBCPP_INLINE_VISIBILITY exception_ptr
make_exception_ptr(_Ep __e) _NOEXCEPT
{
return __copy_exception_ptr(_VSTD::addressof(__e), __GetExceptionInfo(__e));
}
#endif // _LIBCPP_ABI_MICROSOFT
// nested_exception
class _LIBCPP_EXCEPTION_ABI nested_exception
{
exception_ptr __ptr_;
public:
nested_exception() _NOEXCEPT;
// nested_exception(const nested_exception&) noexcept = default;
// nested_exception& operator=(const nested_exception&) noexcept = default;
virtual ~nested_exception() _NOEXCEPT;
// access functions
_LIBCPP_NORETURN void rethrow_nested() const;
_LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
};
template <class _Tp>
struct __nested
: public _Tp,
public nested_exception
{
_LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
};
#ifndef _LIBCPP_NO_EXCEPTIONS
template <class _Tp, class _Up, bool>
struct __throw_with_nested;
template <class _Tp, class _Up>
struct __throw_with_nested<_Tp, _Up, true> {
_LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
__do_throw(_Tp&& __t)
{
throw __nested<_Up>(static_cast<_Tp&&>(__t));
}
};
template <class _Tp, class _Up>
struct __throw_with_nested<_Tp, _Up, false> {
_LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
#ifndef _LIBCPP_CXX03_LANG
__do_throw(_Tp&& __t)
#else
__do_throw (_Tp& __t)
#endif // _LIBCPP_CXX03_LANG
{
throw static_cast<_Tp&&>(__t);
}
};
#endif
template <class _Tp>
_LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
void
throw_with_nested(_Tp&& __t)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
typedef typename decay<_Tp>::type _Up;
static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
__throw_with_nested<_Tp, _Up,
is_class<_Up>::value &&
!is_base_of<nested_exception, _Up>::value &&
!__libcpp_is_final<_Up>::value>::
__do_throw(static_cast<_Tp&&>(__t));
#else
((void)__t);
// FIXME: Make this abort
#endif
}
template <class _From, class _To>
struct __can_dynamic_cast : _BoolConstant<
is_polymorphic<_From>::value &&
(!is_base_of<_To, _From>::value ||
is_convertible<const _From*, const _To*>::value)> {};
template <class _Ep>
inline _LIBCPP_INLINE_VISIBILITY
void
rethrow_if_nested(const _Ep& __e,
__enable_if_t< __can_dynamic_cast<_Ep, nested_exception>::value>* = 0)
{
const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
if (__nep)
__nep->rethrow_nested();
}
template <class _Ep>
inline _LIBCPP_INLINE_VISIBILITY
void
rethrow_if_nested(const _Ep&,
__enable_if_t<!__can_dynamic_cast<_Ep, nested_exception>::value>* = 0)
{
}
} // namespace std
#endif // _LIBCPP_EXCEPTION