gcc/libitm/eh_cpp.cc

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/* Copyright (C) 2009-2014 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Transactional Memory Library (libitm).
Libitm 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 of the License, or
(at your option) any later version.
Libitm 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 "libitm_i.h"
using namespace GTM;
/* Everything from libstdc++ is weak, to avoid requiring that library
to be linked into plain C applications using libitm.so. */
#define WEAK __attribute__((weak))
extern "C" {
extern void *__cxa_allocate_exception (size_t) WEAK;
extern void __cxa_throw (void *, void *, void *) WEAK;
extern void *__cxa_begin_catch (void *) WEAK;
extern void __cxa_end_catch (void) WEAK;
extern void __cxa_tm_cleanup (void *, void *, unsigned int) WEAK;
#if !defined (HAVE_ELF_STYLE_WEAKREF)
void *__cxa_allocate_exception (size_t) { return NULL; }
void __cxa_throw (void *, void *, void *) { return; }
void *__cxa_begin_catch (void *) { return NULL; }
void __cxa_end_catch (void) { return; }
void __cxa_tm_cleanup (void *, void *, unsigned int) { return; }
void _Unwind_DeleteException (_Unwind_Exception *) { return; }
#endif /* HAVE_ELF_STYLE_WEAKREF */
}
void *
_ITM_cxa_allocate_exception (size_t size)
{
void *r = __cxa_allocate_exception (size);
gtm_thr()->cxa_unthrown = r;
return r;
}
void
_ITM_cxa_throw (void *obj, void *tinfo, void *dest)
{
gtm_thr()->cxa_unthrown = NULL;
__cxa_throw (obj, tinfo, dest);
}
void *
_ITM_cxa_begin_catch (void *exc_ptr)
{
gtm_thr()->cxa_catch_count++;
return __cxa_begin_catch (exc_ptr);
}
void
_ITM_cxa_end_catch (void)
{
gtm_thr()->cxa_catch_count--;
__cxa_end_catch ();
}
void
GTM::gtm_thread::revert_cpp_exceptions (gtm_transaction_cp *cp)
{
if (cp)
{
// If rolling back a nested transaction, only clean up unthrown
// exceptions since the last checkpoint. Always reset eh_in_flight
// because it just contains the argument provided to
// _ITM_commitTransactionEH
void *unthrown =
(cxa_unthrown != cp->cxa_unthrown ? cxa_unthrown : NULL);
assert (cxa_catch_count >= cp->cxa_catch_count);
uint32_t catch_count = cxa_catch_count - cp->cxa_catch_count;
if (unthrown || catch_count)
{
__cxa_tm_cleanup (unthrown, this->eh_in_flight, catch_count);
cxa_catch_count = cp->cxa_catch_count;
cxa_unthrown = cp->cxa_unthrown;
this->eh_in_flight = NULL;
}
}
else
{
// Both cxa_catch_count and cxa_unthrown are maximal because EH regions
// and transactions are properly nested.
if (this->cxa_unthrown || this->cxa_catch_count)
{
__cxa_tm_cleanup (this->cxa_unthrown, this->eh_in_flight,
this->cxa_catch_count);
this->cxa_catch_count = 0;
this->cxa_unthrown = NULL;
this->eh_in_flight = NULL;
}
}
}