CWG 616, 1213 - value category of subobject references.
[official-gcc.git] / libgcc / config / rs6000 / cxa_atexit.c
blob0801565efb3f9640f7134beabd0081b55910b1ce
1 /* Copyright (C) 1999-2018 Free Software Foundation, Inc.
3 NOTE: This source is derived from an old version taken from the GNU C
4 Library (glibc).
6 This file is part of GCC.
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.
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.
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.
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/>. */
27 #include <assert.h>
28 #include <stdlib.h>
30 #include "exit.h"
32 #undef __cxa_atexit
34 #define atomic_write_barrier() __asm__ ("eieio" ::: "memory")
36 int
37 attribute_hidden
38 __internal_atexit (void (*func) (void *), void *arg, void *d,
39 struct exit_function_list **listp)
41 struct exit_function *new = __new_exitfn (listp);
43 if (new == NULL)
44 return -1;
46 #ifdef PTR_MANGLE
47 PTR_MANGLE (func);
48 #endif
49 new->func.cxa.fn = (void (*) (void *, int)) func;
50 new->func.cxa.arg = arg;
51 new->func.cxa.dso_handle = d;
52 atomic_write_barrier ();
53 new->flavor = ef_cxa;
54 return 0;
58 /* Register a function to be called by exit or when a shared library
59 is unloaded. This function is only called from code generated by
60 the C++ compiler. */
61 int
62 __cxa_atexit (void (*func) (void *), void *arg, void *d)
64 return __internal_atexit (func, arg, d, &__exit_funcs);
66 INTDEF(__cxa_atexit)
69 static struct exit_function_list initial;
70 struct exit_function_list *__exit_funcs = &initial;
71 uint64_t __new_exitfn_called;
73 struct exit_function *
74 __new_exitfn (struct exit_function_list **listp)
76 struct exit_function_list *p = NULL;
77 struct exit_function_list *l;
78 struct exit_function *r = NULL;
79 size_t i = 0;
81 for (l = *listp; l != NULL; p = l, l = l->next)
83 for (i = l->idx; i > 0; --i)
84 if (l->fns[i - 1].flavor != ef_free)
85 break;
87 if (i > 0)
88 break;
90 /* This block is completely unused. */
91 l->idx = 0;
94 if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
96 /* The last entry in a block is used. Use the first entry in
97 the previous block if it exists. Otherwise create a new one. */
98 if (p == NULL)
100 assert (l != NULL);
101 p = (struct exit_function_list *)
102 calloc (1, sizeof (struct exit_function_list));
103 if (p != NULL)
105 p->next = *listp;
106 *listp = p;
110 if (p != NULL)
112 r = &p->fns[0];
113 p->idx = 1;
116 else
118 /* There is more room in the block. */
119 r = &l->fns[i];
120 l->idx = i + 1;
123 /* Mark entry as used, but we don't know the flavor now. */
124 if (r != NULL)
126 r->flavor = ef_us;
127 ++__new_exitfn_called;
130 return r;