1 | /* Startup support for ELF initializers/finalizers in the main executable. |
2 | Copyright (C) 2002-2020 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | In addition to the permissions in the GNU Lesser General Public |
11 | License, the Free Software Foundation gives you unlimited |
12 | permission to link the compiled version of this file with other |
13 | programs, and to distribute those programs without any restriction |
14 | coming from the use of this file. (The GNU Lesser General Public |
15 | License restrictions do apply in other respects; for example, they |
16 | cover modification of the file, and distribution when not linked |
17 | into another program.) |
18 | |
19 | Note that people who make modified versions of this file are not |
20 | obligated to grant this special exception for their modified |
21 | versions; it is their choice whether to do so. The GNU Lesser |
22 | General Public License gives permission to release a modified |
23 | version without this exception; this exception also makes it |
24 | possible to release a modified version which carries forward this |
25 | exception. |
26 | |
27 | The GNU C Library is distributed in the hope that it will be useful, |
28 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
29 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
30 | Lesser General Public License for more details. |
31 | |
32 | You should have received a copy of the GNU Lesser General Public |
33 | License along with the GNU C Library; if not, see |
34 | <https://www.gnu.org/licenses/>. */ |
35 | |
36 | #include <stddef.h> |
37 | |
38 | |
39 | /* These magic symbols are provided by the linker. */ |
40 | extern void (*__preinit_array_start []) (int, char **, char **) |
41 | attribute_hidden; |
42 | extern void (*__preinit_array_end []) (int, char **, char **) |
43 | attribute_hidden; |
44 | extern void (*__init_array_start []) (int, char **, char **) |
45 | attribute_hidden; |
46 | extern void (*__init_array_end []) (int, char **, char **) |
47 | attribute_hidden; |
48 | extern void (*__fini_array_start []) (void) attribute_hidden; |
49 | extern void (*__fini_array_end []) (void) attribute_hidden; |
50 | |
51 | |
52 | #ifndef NO_INITFINI |
53 | /* These function symbols are provided for the .init/.fini section entry |
54 | points automagically by the linker. */ |
55 | extern void _init (void); |
56 | extern void _fini (void); |
57 | #endif |
58 | |
59 | |
60 | /* These functions are passed to __libc_start_main by the startup code. |
61 | These get statically linked into each program. For dynamically linked |
62 | programs, this module will come from libc_nonshared.a and differs from |
63 | the libc.a module in that it doesn't call the preinit array. */ |
64 | |
65 | |
66 | void |
67 | __libc_csu_init (int argc, char **argv, char **envp) |
68 | { |
69 | /* For dynamically linked executables the preinit array is executed by |
70 | the dynamic linker (before initializing any shared object). */ |
71 | |
72 | #ifndef LIBC_NONSHARED |
73 | /* For static executables, preinit happens right before init. */ |
74 | { |
75 | const size_t size = __preinit_array_end - __preinit_array_start; |
76 | size_t i; |
77 | for (i = 0; i < size; i++) |
78 | (*__preinit_array_start [i]) (argc, argv, envp); |
79 | } |
80 | #endif |
81 | |
82 | #ifndef NO_INITFINI |
83 | _init (); |
84 | #endif |
85 | |
86 | const size_t size = __init_array_end - __init_array_start; |
87 | for (size_t i = 0; i < size; i++) |
88 | (*__init_array_start [i]) (argc, argv, envp); |
89 | } |
90 | |
91 | /* This function should not be used anymore. We run the executable's |
92 | destructor now just like any other. We cannot remove the function, |
93 | though. */ |
94 | void |
95 | __libc_csu_fini (void) |
96 | { |
97 | #ifndef LIBC_NONSHARED |
98 | size_t i = __fini_array_end - __fini_array_start; |
99 | while (i-- > 0) |
100 | (*__fini_array_start [i]) (); |
101 | |
102 | # ifndef NO_INITFINI |
103 | _fini (); |
104 | # endif |
105 | #endif |
106 | } |
107 | |