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Serenity Operating System
1/*
2 * Copyright (c) 2019-2020, Andrew Kaster <andrewdkaster@gmail.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/Types.h>
28#include <assert.h>
29#include <stdio.h>
30#include <stdlib.h>
31
32//#define GLOBAL_DTORS_DEBUG
33
34extern "C" {
35
36typedef void (*AtExitFunction)(void*);
37
38struct __exit_entry {
39 AtExitFunction method;
40 void* parameter;
41 void* dso_handle;
42 bool has_been_called;
43};
44
45static __exit_entry __exit_entries[1024] {};
46static int __exit_entry_count = 0;
47
48int __cxa_atexit(AtExitFunction exit_function, void* parameter, void* dso_handle)
49{
50 if (__exit_entry_count >= 1024)
51 return -1;
52
53 __exit_entries[__exit_entry_count++] = { exit_function, parameter, dso_handle, false };
54
55 return 0;
56}
57
58void __cxa_finalize(void* dso_handle)
59{
60 // From the itanium abi, https://itanium-cxx-abi.github.io/cxx-abi/abi.html#dso-dtor-runtime-api
61 //
62 // When __cxa_finalize(d) is called, it should walk the termination function list, calling each in turn
63 // if d matches __dso_handle for the termination function entry. If d == NULL, it should call all of them.
64 // Multiple calls to __cxa_finalize shall not result in calling termination function entries multiple times;
65 // the implementation may either remove entries or mark them finished.
66
67 int entry_index = __exit_entry_count;
68
69#ifdef GLOBAL_DTORS_DEBUG
70 dbgprintf("__cxa_finalize: %d entries in the finalizer list\n", entry_index);
71#endif
72
73 while (--entry_index >= 0) {
74 auto& exit_entry = __exit_entries[entry_index];
75 bool needs_calling = !exit_entry.has_been_called && (!dso_handle || dso_handle == exit_entry.dso_handle);
76 if (needs_calling) {
77#ifdef GLOBAL_DTORS_DEBUG
78 dbgprintf("__cxa_finalize: calling entry[%d] %p(%p) dso: %p\n", entry_index, exit_entry.method, exit_entry.parameter, exit_entry.dso_handle);
79#endif
80 exit_entry.method(exit_entry.parameter);
81 exit_entry.has_been_called = true;
82 }
83 }
84}
85
86} // extern "C"