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d7ad6040 JL |
1 | /* .init/.fini section handling + C++ global constructor/destructor handling. |
2 | This file is based on crtstuff.c, sol2-crti.asm, sol2-crtn.asm. | |
3 | ||
748086b7 | 4 | Copyright (C) 1995, 1997, 1998, 2009 Free Software Foundation, Inc. |
d7ad6040 | 5 | |
7ec022b2 | 6 | This file is part of GCC. |
d7ad6040 | 7 | |
7ec022b2 | 8 | GCC is free software; you can redistribute it and/or modify |
d7ad6040 | 9 | it under the terms of the GNU General Public License as published by |
748086b7 | 10 | the Free Software Foundation; either version 3, or (at your option) |
d7ad6040 JL |
11 | any later version. |
12 | ||
7ec022b2 | 13 | GCC is distributed in the hope that it will be useful, |
d7ad6040 JL |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
748086b7 JJ |
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. | |
21 | ||
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/>. */ | |
d7ad6040 | 26 | |
d7ad6040 JL |
27 | /* Declare a pointer to void function type. */ |
28 | typedef void (*func_ptr) (void); | |
29 | ||
30 | #ifdef CRT_INIT | |
31 | ||
32 | /* NOTE: In order to be able to support SVR4 shared libraries, we arrange | |
33 | to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__, | |
34 | __DTOR_END__ } per root executable and also one set of these symbols | |
35 | per shared library. So in any given whole process image, we may have | |
36 | multiple definitions of each of these symbols. In order to prevent | |
37 | these definitions from conflicting with one another, and in order to | |
38 | ensure that the proper lists are used for the initialization/finalization | |
39 | of each individual shared library (respectively), we give these symbols | |
40 | only internal (i.e. `static') linkage, and we also make it a point to | |
41 | refer to only the __CTOR_END__ symbol in crtfini.o and the __DTOR_LIST__ | |
42 | symbol in crtinit.o, where they are defined. */ | |
43 | ||
44 | static func_ptr __CTOR_LIST__[1] __attribute__ ((section (".ctors"))) | |
45 | = { (func_ptr) (-1) }; | |
46 | ||
47 | static func_ptr __DTOR_LIST__[1] __attribute__ ((section (".dtors"))) | |
48 | = { (func_ptr) (-1) }; | |
49 | ||
50 | /* Run all the global destructors on exit from the program. */ | |
51 | ||
52 | /* Some systems place the number of pointers in the first word of the | |
53 | table. On SVR4 however, that word is -1. In all cases, the table is | |
54 | null-terminated. On SVR4, we start from the beginning of the list and | |
55 | invoke each per-compilation-unit destructor routine in order | |
56 | until we find that null. | |
57 | ||
58 | Note that this function MUST be static. There will be one of these | |
59 | functions in each root executable and one in each shared library, but | |
60 | although they all have the same code, each one is unique in that it | |
61 | refers to one particular associated `__DTOR_LIST__' which belongs to the | |
62 | same particular root executable or shared library file. */ | |
63 | ||
2b49e0aa | 64 | static void __do_global_dtors (void) |
d7ad6040 JL |
65 | asm ("__do_global_dtors") __attribute__ ((section (".text"))); |
66 | ||
67 | static void | |
2b49e0aa | 68 | __do_global_dtors (void) |
d7ad6040 JL |
69 | { |
70 | func_ptr *p; | |
71 | for (p = __DTOR_LIST__ + 1; *p; p++) | |
72 | (*p) (); | |
73 | } | |
74 | ||
75 | /* .init section start. | |
76 | This must appear at the start of the .init section. */ | |
77 | ||
ab87f8c8 JL |
78 | asm ("\n\ |
79 | .section .init\n\ | |
80 | .global init\n\ | |
81 | .word 0\n\ | |
82 | init:\n\ | |
83 | st blink,[sp,4]\n\ | |
84 | st fp,[sp]\n\ | |
85 | mov fp,sp\n\ | |
86 | sub sp,sp,16\n\ | |
d7ad6040 JL |
87 | "); |
88 | ||
89 | /* .fini section start. | |
90 | This must appear at the start of the .init section. */ | |
91 | ||
ab87f8c8 JL |
92 | asm ("\n\ |
93 | .section .fini\n\ | |
94 | .global fini\n\ | |
95 | .word 0\n\ | |
96 | fini:\n\ | |
97 | st blink,[sp,4]\n\ | |
98 | st fp,[sp]\n\ | |
99 | mov fp,sp\n\ | |
100 | sub sp,sp,16\n\ | |
101 | bl.nd __do_global_dtors\n\ | |
d7ad6040 JL |
102 | "); |
103 | ||
104 | #endif /* CRT_INIT */ | |
105 | ||
106 | #ifdef CRT_FINI | |
107 | ||
108 | /* Put a word containing zero at the end of each of our two lists of function | |
109 | addresses. Note that the words defined here go into the .ctors and .dtors | |
110 | sections of the crtend.o file, and since that file is always linked in | |
111 | last, these words naturally end up at the very ends of the two lists | |
112 | contained in these two sections. */ | |
113 | ||
114 | static func_ptr __CTOR_END__[1] __attribute__ ((section (".ctors"))) | |
115 | = { (func_ptr) 0 }; | |
116 | ||
117 | static func_ptr __DTOR_END__[1] __attribute__ ((section (".dtors"))) | |
118 | = { (func_ptr) 0 }; | |
119 | ||
120 | /* Run all global constructors for the program. | |
121 | Note that they are run in reverse order. */ | |
122 | ||
2b49e0aa | 123 | static void __do_global_ctors (void) |
d7ad6040 JL |
124 | asm ("__do_global_ctors") __attribute__ ((section (".text"))); |
125 | ||
126 | static void | |
2b49e0aa | 127 | __do_global_ctors (void) |
d7ad6040 JL |
128 | { |
129 | func_ptr *p; | |
130 | for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) | |
131 | (*p) (); | |
132 | } | |
133 | ||
134 | /* .init section end. | |
135 | This must live at the end of the .init section. */ | |
136 | ||
ab87f8c8 JL |
137 | asm ("\n\ |
138 | .section .init\n\ | |
f811f821 | 139 | bl.nd __do_global_ctors\n\ |
ab87f8c8 JL |
140 | ld blink,[fp,4]\n\ |
141 | j.d blink\n\ | |
142 | ld.a fp,[sp,16]\n\ | |
d7ad6040 JL |
143 | "); |
144 | ||
145 | /* .fini section end. | |
146 | This must live at the end of the .fini section. */ | |
147 | ||
ab87f8c8 JL |
148 | asm ("\n\ |
149 | .section .fini\n\ | |
150 | ld blink,[fp,4]\n\ | |
151 | j.d blink\n\ | |
152 | ld.a fp,[sp,16]\n\ | |
d7ad6040 JL |
153 | "); |
154 | ||
155 | #endif /* CRT_FINI */ |