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/* Copyright (C) 1999-2021 Free Software Foundation, Inc.
NOTE: This source is derived from an old version taken from the GNU C
Library (glibc).
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 <assert.h>
#include <stdlib.h>
#include "exit.h"
#undef __cxa_atexit
#define atomic_write_barrier() __asm__ ("eieio" ::: "memory")
int
attribute_hidden
__internal_atexit (void (*func) (void *), void *arg, void *d,
struct exit_function_list **listp)
{
struct exit_function *new = __new_exitfn (listp);
if (new == NULL)
return -1;
#ifdef PTR_MANGLE
PTR_MANGLE (func);
#endif
new->func.cxa.fn = (void (*) (void *, int)) func;
new->func.cxa.arg = arg;
new->func.cxa.dso_handle = d;
atomic_write_barrier ();
new->flavor = ef_cxa;
return 0;
}
/* Register a function to be called by exit or when a shared library
is unloaded. This function is only called from code generated by
the C++ compiler. */
int
__cxa_atexit (void (*func) (void *), void *arg, void *d)
{
return __internal_atexit (func, arg, d, &__exit_funcs);
}
INTDEF(__cxa_atexit)
static struct exit_function_list initial;
struct exit_function_list *__exit_funcs = &initial;
uint64_t __new_exitfn_called;
struct exit_function *
__new_exitfn (struct exit_function_list **listp)
{
struct exit_function_list *p = NULL;
struct exit_function_list *l;
struct exit_function *r = NULL;
size_t i = 0;
for (l = *listp; l != NULL; p = l, l = l->next)
{
for (i = l->idx; i > 0; --i)
if (l->fns[i - 1].flavor != ef_free)
break;
if (i > 0)
break;
/* This block is completely unused. */
l->idx = 0;
}
if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
{
/* The last entry in a block is used. Use the first entry in
the previous block if it exists. Otherwise create a new one. */
if (p == NULL)
{
assert (l != NULL);
p = (struct exit_function_list *)
calloc (1, sizeof (struct exit_function_list));
if (p != NULL)
{
p->next = *listp;
*listp = p;
}
}
if (p != NULL)
{
r = &p->fns[0];
p->idx = 1;
}
}
else
{
/* There is more room in the block. */
r = &l->fns[i];
l->idx = i + 1;
}
/* Mark entry as used, but we don't know the flavor now. */
if (r != NULL)
{
r->flavor = ef_us;
++__new_exitfn_called;
}
return r;
}