libgcc/config/rs6000/cxa_finalize.c

   1 /* Copyright (C) 1999-2018 Free Software Foundation, Inc.
   2
   3    NOTE: This source is derived from an old version taken from the GNU C
   4    Library (glibc).
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #include <assert.h>
  28 #include <stdlib.h>
  29 #include "exit.h"
  30
  31
  32 static boolean_t
  33 catomic_compare_and_exchange_bool_acq (long *mem, long newval, long oldval)
  34 {
  35   return ! __atomic_compare_exchange (mem, &oldval, &newval, 0,
  36                                       __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
  37 }
  38
  39 /* If D is non-NULL, call all functions registered with `__cxa_atexit'
  40    with the same dso handle.  Otherwise, if D is NULL, call all of the
  41    registered handlers.  */
  42 void
  43 __cxa_finalize (void *d)
  44 {
  45   struct exit_function_list *funcs;
  46
  47  restart:
  48   for (funcs = __exit_funcs; funcs; funcs = funcs->next)
  49     {
  50       struct exit_function *f;
  51
  52       for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f)
  53         {
  54           void (*cxafn) (void *arg, int status);
  55           void *cxaarg;
  56
  57           if ((d == NULL || d == f->func.cxa.dso_handle)
  58               /* We don't want to run this cleanup more than once.  */
  59               && (cxafn = f->func.cxa.fn,
  60                   cxaarg = f->func.cxa.arg,
  61                   ! catomic_compare_and_exchange_bool_acq (&f->flavor, ef_free,
  62                                                            ef_cxa)))
  63             {
  64               uint64_t check = __new_exitfn_called;
  65
  66 #ifdef PTR_DEMANGLE
  67               PTR_DEMANGLE (cxafn);
  68 #endif
  69               cxafn (cxaarg, 0);
  70
  71               /* It is possible that that last exit function registered
  72                  more exit functions.  Start the loop over.  */
  73               if (__builtin_expect (check != __new_exitfn_called, 0))
  74                 goto restart;
  75             }
  76         }
  77     }
  78
  79   /* Remove the registered fork handlers.  We do not have to
  80      unregister anything if the program is going to terminate anyway.  */
  81 #ifdef UNREGISTER_ATFORK
  82   if (d != NULL)
  83     UNREGISTER_ATFORK (d);
  84 #endif
  85 }