// -*- C++ -*- Implement the members of exception_ptr.
// Copyright (C) 2008-2015 Free Software Foundation, Inc.
//
// This file is part of GCC.
//
// GCC is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3, or (at your option)
// any later version.
//
// GCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
#include <bits/c++config.h>
#include <bits/atomic_lockfree_defines.h>
#if ATOMIC_INT_LOCK_FREE > 1
#define _GLIBCXX_EH_PTR_COMPAT
#include <exception>
#include <bits/exception_ptr.h>
#include "unwind-cxx.h"
using namespace __cxxabiv1;
// Verify assumptions about member layout in exception types
namespace
{
template<typename Ex>
constexpr std::size_t unwindhdr()
{ return offsetof(Ex, unwindHeader); }
template<typename Ex>
constexpr std::size_t termHandler()
{ return unwindhdr<Ex>() - offsetof(Ex, terminateHandler); }
static_assert( termHandler<__cxa_exception>()
== termHandler<__cxa_dependent_exception>(),
"__cxa_dependent_exception::termHandler layout must be"
" consistent with __cxa_exception::termHandler" );
#ifndef __ARM_EABI_UNWINDER__
template<typename Ex>
constexpr std::ptrdiff_t adjptr()
{ return unwindhdr<Ex>() - offsetof(Ex, adjustedPtr); }
static_assert( adjptr<__cxa_exception>()
== adjptr<__cxa_dependent_exception>(),
"__cxa_dependent_exception::adjustedPtr layout must be"
" consistent with __cxa_exception::adjustedPtr" );
#endif
}
std::__exception_ptr::exception_ptr::exception_ptr() _GLIBCXX_USE_NOEXCEPT
: _M_exception_object(0) { }
std::__exception_ptr::exception_ptr::exception_ptr(void* obj)
_GLIBCXX_USE_NOEXCEPT
: _M_exception_object(obj) { _M_addref(); }
std::__exception_ptr::exception_ptr::exception_ptr(__safe_bool)
_GLIBCXX_USE_NOEXCEPT
: _M_exception_object(0) { }
std::__exception_ptr::
exception_ptr::exception_ptr(const exception_ptr& other) _GLIBCXX_USE_NOEXCEPT
: _M_exception_object(other._M_exception_object)
{ _M_addref(); }
std::__exception_ptr::exception_ptr::~exception_ptr() _GLIBCXX_USE_NOEXCEPT
{ _M_release(); }
std::__exception_ptr::exception_ptr&
std::__exception_ptr::
exception_ptr::operator=(const exception_ptr& other) _GLIBCXX_USE_NOEXCEPT
{
exception_ptr(other).swap(*this);
return *this;
}
void
std::__exception_ptr::exception_ptr::_M_addref() _GLIBCXX_USE_NOEXCEPT
{
if (_M_exception_object)
{
__cxa_refcounted_exception *eh =
__get_refcounted_exception_header_from_obj (_M_exception_object);
__atomic_add_fetch (&eh->referenceCount, 1, __ATOMIC_ACQ_REL);
}
}
void
std::__exception_ptr::exception_ptr::_M_release() _GLIBCXX_USE_NOEXCEPT
{
if (_M_exception_object)
{
__cxa_refcounted_exception *eh =
__get_refcounted_exception_header_from_obj (_M_exception_object);
if (__atomic_sub_fetch (&eh->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
{
if (eh->exc.exceptionDestructor)
eh->exc.exceptionDestructor (_M_exception_object);
__cxa_free_exception (_M_exception_object);
_M_exception_object = 0;
}
}
}
void*
std::__exception_ptr::exception_ptr::_M_get() const _GLIBCXX_USE_NOEXCEPT
{ return _M_exception_object; }
void
std::__exception_ptr::exception_ptr::swap(exception_ptr &other)
_GLIBCXX_USE_NOEXCEPT
{
void *tmp = _M_exception_object;
_M_exception_object = other._M_exception_object;
other._M_exception_object = tmp;
}
// Retained for compatibility with CXXABI_1.3.
void
std::__exception_ptr::exception_ptr::_M_safe_bool_dummy()
_GLIBCXX_USE_NOEXCEPT { }
// Retained for compatibility with CXXABI_1.3.
bool
std::__exception_ptr::exception_ptr::operator!() const _GLIBCXX_USE_NOEXCEPT
{ return _M_exception_object == 0; }
// Retained for compatibility with CXXABI_1.3.
std::__exception_ptr::exception_ptr::operator __safe_bool() const
_GLIBCXX_USE_NOEXCEPT
{
return _M_exception_object ? &exception_ptr::_M_safe_bool_dummy : 0;
}
const std::type_info*
std::__exception_ptr::exception_ptr::__cxa_exception_type() const
_GLIBCXX_USE_NOEXCEPT
{
__cxa_exception *eh = __get_exception_header_from_obj (_M_exception_object);
return eh->exceptionType;
}
bool std::__exception_ptr::operator==(const exception_ptr& lhs,
const exception_ptr& rhs)
_GLIBCXX_USE_NOEXCEPT
{ return lhs._M_exception_object == rhs._M_exception_object; }
bool std::__exception_ptr::operator!=(const exception_ptr& lhs,
const exception_ptr& rhs)
_GLIBCXX_USE_NOEXCEPT
{ return !(lhs == rhs);}
std::exception_ptr
std::current_exception() _GLIBCXX_USE_NOEXCEPT
{
__cxa_eh_globals *globals = __cxa_get_globals ();
__cxa_exception *header = globals->caughtExceptions;
if (!header)
return std::exception_ptr();
// Since foreign exceptions can't be counted, we can't return them.
if (!__is_gxx_exception_class (header->unwindHeader.exception_class))
return std::exception_ptr();
return std::exception_ptr(
__get_object_from_ambiguous_exception (header));
}
static void
__gxx_dependent_exception_cleanup(_Unwind_Reason_Code code,
_Unwind_Exception *exc)
{
// This cleanup is set only for dependents.
__cxa_dependent_exception *dep = __get_dependent_exception_from_ue (exc);
__cxa_refcounted_exception *header =
__get_refcounted_exception_header_from_obj (dep->primaryException);
// We only want to be called through _Unwind_DeleteException.
// _Unwind_DeleteException in the HP-UX IA64 libunwind library
// returns _URC_NO_REASON and not _URC_FOREIGN_EXCEPTION_CAUGHT
// like the GCC _Unwind_DeleteException function does.
if (code != _URC_FOREIGN_EXCEPTION_CAUGHT && code != _URC_NO_REASON)
__terminate (header->exc.terminateHandler);
__cxa_free_dependent_exception (dep);
if (__atomic_sub_fetch (&header->referenceCount, 1, __ATOMIC_ACQ_REL) == 0)
{
if (header->exc.exceptionDestructor)
header->exc.exceptionDestructor (header + 1);
__cxa_free_exception (header + 1);
}
}
void
std::rethrow_exception(std::exception_ptr ep)
{
void *obj = ep._M_get();
__cxa_refcounted_exception *eh
= __get_refcounted_exception_header_from_obj (obj);
__cxa_dependent_exception *dep = __cxa_allocate_dependent_exception ();
dep->primaryException = obj;
__atomic_add_fetch (&eh->referenceCount, 1, __ATOMIC_ACQ_REL);
dep->unexpectedHandler = get_unexpected ();
dep->terminateHandler = get_terminate ();
__GXX_INIT_DEPENDENT_EXCEPTION_CLASS(dep->unwindHeader.exception_class);
dep->unwindHeader.exception_cleanup = __gxx_dependent_exception_cleanup;
__cxa_eh_globals *globals = __cxa_get_globals ();
globals->uncaughtExceptions += 1;
#ifdef _GLIBCXX_SJLJ_EXCEPTIONS
_Unwind_SjLj_RaiseException (&dep->unwindHeader);
#else
_Unwind_RaiseException (&dep->unwindHeader);
#endif
// Some sort of unwinding error. Note that terminate is a handler.
__cxa_begin_catch (&dep->unwindHeader);
std::terminate();
}
#undef _GLIBCXX_EH_PTR_COMPAT
#endif