caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
0f8412c19c32dbda994248bc1bdfd6bc71346049
clang-p2996/libcxx/include/exception
Paul Kirth 56a34451e1 [libcxx] Fix using the vcruntime ABI with _HAS_EXCEPTIONS=0 defined 
_HAS_EXCEPTIONS=0 allows disabling the exception parts of the MS STL
and vcruntime, and e.g. compiler-rt/lib/fuzzer sets this define (to
work around issues with MS STL). If using libc++ instead of MS STL,
this define previously broke the libc++ headers.

If _HAS_EXCEPTIONS is set to 0, the vcruntime_exception.h header
doesn't define the ABI base class std::exception. If no exceptions
are going to be thrown, this probably is fine (although it also
breaks using subclasses of it as regular objects that aren't thrown),
but it requires ifdeffing out all subclasses of all exception/error
derived objects (which are sprinkled throughout the headers).

Instead, libc++ will supply an ABI compatible definition when
_HAS_EXCEPTIONS is set to 0, which will make the class hierarchies
complete.

In this build configuration, one can still create instances of
exception subclasses, and those objects will be ABI incompatible
with the ones from when _HAS_EXCEPTIONS isn't defined to 0 - but
one may argue that's a pathological/self-imposed problem in that case.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D103947
2022-08-17 21:14:25 +00:00

375 lines
11 KiB
C++
Raw Blame History

// -*- 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
Reference in New Issue View Git Blame Copy Permalink