1/* Copyright (C) 1999-2015 Free Software Foundation, Inc. 2 3 NOTE: This source is derived from an old version taken from the GNU C 4 Library (glibc). 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18Under Section 7 of GPL version 3, you are granted additional 19permissions described in the GCC Runtime Library Exception, version 203.1, as published by the Free Software Foundation. 21 22You should have received a copy of the GNU General Public License and 23a copy of the GCC Runtime Library Exception along with this program; 24see 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 30#include "exit.h" 31 32#undef __cxa_atexit 33 34#define atomic_write_barrier() __asm__ ("eieio" ::: "memory") 35 36int 37attribute_hidden 38__internal_atexit (void (*func) (void *), void *arg, void *d, 39 struct exit_function_list **listp) 40{ 41 struct exit_function *new = __new_exitfn (listp); 42 43 if (new == NULL) 44 return -1; 45 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; 55} 56 57 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. */ 61int 62__cxa_atexit (void (*func) (void *), void *arg, void *d) 63{ 64 return __internal_atexit (func, arg, d, &__exit_funcs); 65} 66INTDEF(__cxa_atexit) 67 68 69static struct exit_function_list initial; 70struct exit_function_list *__exit_funcs = &initial; 71uint64_t __new_exitfn_called; 72 73struct exit_function * 74__new_exitfn (struct exit_function_list **listp) 75{ 76 struct exit_function_list *p = NULL; 77 struct exit_function_list *l; 78 struct exit_function *r = NULL; 79 size_t i = 0; 80 81 for (l = *listp; l != NULL; p = l, l = l->next) 82 { 83 for (i = l->idx; i > 0; --i) 84 if (l->fns[i - 1].flavor != ef_free) 85 break; 86 87 if (i > 0) 88 break; 89 90 /* This block is completely unused. */ 91 l->idx = 0; 92 } 93 94 if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0])) 95 { 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) 99 { 100 assert (l != NULL); 101 p = (struct exit_function_list *) 102 calloc (1, sizeof (struct exit_function_list)); 103 if (p != NULL) 104 { 105 p->next = *listp; 106 *listp = p; 107 } 108 } 109 110 if (p != NULL) 111 { 112 r = &p->fns[0]; 113 p->idx = 1; 114 } 115 } 116 else 117 { 118 /* There is more room in the block. */ 119 r = &l->fns[i]; 120 l->idx = i + 1; 121 } 122 123 /* Mark entry as used, but we don't know the flavor now. */ 124 if (r != NULL) 125 { 126 r->flavor = ef_us; 127 ++__new_exitfn_called; 128 } 129 130 return r; 131} 132