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1 | /* Specialized bits of code needed to support construction and | |
2 | destruction of file-scope objects in C++ code. | |
3 | Copyright (C) 1991-2025 Free Software Foundation, Inc. | |
4 | Contributed by Ron Guilmette (rfg@monkeys.com). | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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/>. */ | |
26 | ||
27 | /* This file is a bit like libgcc2.c in that it is compiled | |
28 | multiple times and yields multiple .o files. | |
29 | ||
30 | This file is useful on target machines where the object file format | |
31 | supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE). On | |
32 | such systems, this file allows us to avoid running collect (or any | |
33 | other such slow and painful kludge). Additionally, if the target | |
34 | system supports a .init section, this file allows us to support the | |
35 | linking of C++ code with a non-C++ main program. | |
36 | ||
37 | Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then | |
38 | this file *will* make use of the .init section. If that symbol is | |
39 | not defined however, then the .init section will not be used. | |
40 | ||
41 | Currently, only ELF and COFF are supported. It is likely however that | |
42 | ROSE could also be supported, if someone was willing to do the work to | |
43 | make whatever (small?) adaptations are needed. (Some work may be | |
44 | needed on the ROSE assembler and linker also.) | |
45 | ||
46 | This file must be compiled with gcc. */ | |
47 | ||
48 | /* Target machine header files require this define. */ | |
49 | #define IN_LIBGCC2 | |
50 | ||
51 | /* FIXME: Including auto-host is incorrect, but until we have | |
52 | identified the set of defines that need to go into auto-target.h, | |
53 | this will have to do. */ | |
54 | #include "auto-host.h" | |
55 | #undef caddr_t | |
56 | #undef pid_t | |
57 | #undef rlim_t | |
58 | #undef ssize_t | |
59 | #undef vfork | |
60 | #include "tconfig.h" | |
61 | #include "tsystem.h" | |
62 | #include "coretypes.h" | |
63 | #include "tm.h" | |
64 | #include "libgcc_tm.h" | |
65 | #include "unwind-dw2-fde.h" | |
66 | ||
67 | #ifndef FORCE_CODE_SECTION_ALIGN | |
68 | # define FORCE_CODE_SECTION_ALIGN | |
69 | #endif | |
70 | ||
71 | #ifndef CRT_CALL_STATIC_FUNCTION | |
72 | # define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \ | |
73 | static void __attribute__((__used__)) \ | |
74 | call_ ## FUNC (void) \ | |
75 | { \ | |
76 | asm (SECTION_OP); \ | |
77 | FUNC (); \ | |
78 | FORCE_CODE_SECTION_ALIGN \ | |
79 | asm (__LIBGCC_TEXT_SECTION_ASM_OP__); \ | |
80 | } | |
81 | #endif | |
82 | ||
83 | #if defined(TARGET_DL_ITERATE_PHDR) && \ | |
84 | (defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__)) | |
85 | #define BSD_DL_ITERATE_PHDR_AVAILABLE | |
86 | #endif | |
87 | ||
88 | #if defined(OBJECT_FORMAT_ELF) \ | |
89 | && !defined(OBJECT_FORMAT_FLAT) \ | |
90 | && defined(HAVE_LD_EH_FRAME_HDR) \ | |
91 | && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \ | |
92 | && defined(BSD_DL_ITERATE_PHDR_AVAILABLE) | |
93 | #include <link.h> | |
94 | # define USE_PT_GNU_EH_FRAME | |
95 | #endif | |
96 | ||
97 | #if defined(OBJECT_FORMAT_ELF) \ | |
98 | && !defined(OBJECT_FORMAT_FLAT) \ | |
99 | && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR) \ | |
100 | && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \ | |
101 | && defined(__sun__) && defined(__svr4__) | |
102 | #include <link.h> | |
103 | # define USE_PT_GNU_EH_FRAME | |
104 | #endif | |
105 | ||
106 | #if defined(OBJECT_FORMAT_ELF) \ | |
107 | && !defined(OBJECT_FORMAT_FLAT) \ | |
108 | && defined(HAVE_LD_EH_FRAME_HDR) \ | |
109 | && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \ | |
110 | && defined(__GLIBC__) && __GLIBC__ >= 2 | |
111 | #include <link.h> | |
112 | /* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h. | |
113 | But it doesn't use PT_GNU_EH_FRAME ELF segment currently. */ | |
114 | # if !defined(__UCLIBC__) \ | |
115 | && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \ | |
116 | || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG))) | |
117 | # define USE_PT_GNU_EH_FRAME | |
118 | # endif | |
119 | #endif | |
120 | ||
121 | #if defined(OBJECT_FORMAT_ELF) \ | |
122 | && !defined(OBJECT_FORMAT_FLAT) \ | |
123 | && defined(HAVE_LD_EH_FRAME_HDR) \ | |
124 | && !defined(CRTSTUFFT_O) \ | |
125 | && defined(inhibit_libc) \ | |
126 | && (defined(__GLIBC__) || defined(__gnu_linux__) || defined(__GNU__)) | |
127 | /* On systems using glibc, an inhibit_libc build of libgcc is only | |
128 | part of a bootstrap process. Build the same crt*.o as would be | |
129 | built with headers present, so that it is not necessary to build | |
130 | glibc more than once for the bootstrap to converge. */ | |
131 | # define USE_PT_GNU_EH_FRAME | |
132 | #endif | |
133 | ||
134 | #ifdef USE_EH_FRAME_REGISTRY_ALWAYS | |
135 | # ifndef __LIBGCC_EH_FRAME_SECTION_NAME__ | |
136 | # error "Can't use explicit exception-frame-registration without __LIBGCC_EH_FRAME_SECTION_NAME__" | |
137 | # endif | |
138 | #endif | |
139 | #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) && (!defined(USE_PT_GNU_EH_FRAME) || defined(USE_EH_FRAME_REGISTRY_ALWAYS)) | |
140 | # define USE_EH_FRAME_REGISTRY | |
141 | #endif | |
142 | #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) \ | |
143 | && __LIBGCC_EH_TABLES_CAN_BE_READ_ONLY__ | |
144 | # define EH_FRAME_SECTION_CONST const | |
145 | #else | |
146 | # define EH_FRAME_SECTION_CONST | |
147 | #endif | |
148 | ||
149 | #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \ | |
150 | && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP) | |
151 | # define HIDDEN_DTOR_LIST_END | |
152 | #endif | |
153 | ||
154 | #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF) | |
155 | # define USE_TM_CLONE_REGISTRY 1 | |
156 | #elif !defined(USE_TM_CLONE_REGISTRY) | |
157 | # define USE_TM_CLONE_REGISTRY 0 | |
158 | #endif | |
159 | ||
160 | /* We do not want to add the weak attribute to the declarations of these | |
161 | routines in unwind-dw2-fde.h because that will cause the definition of | |
162 | these symbols to be weak as well. | |
163 | ||
164 | This exposes a core issue, how to handle creating weak references vs | |
165 | how to create weak definitions. Either we have to have the definition | |
166 | of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or | |
167 | have a second declaration if we want a function's references to be weak, | |
168 | but not its definition. | |
169 | ||
170 | Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until | |
171 | one thinks about scaling to larger problems -- i.e., the condition under | |
172 | which TARGET_WEAK_ATTRIBUTE is active will eventually get far too | |
173 | complicated. | |
174 | ||
175 | So, we take an approach similar to #pragma weak -- we have a second | |
176 | declaration for functions that we want to have weak references. | |
177 | ||
178 | Neither way is particularly good. */ | |
179 | ||
180 | /* References to __register_frame_info and __deregister_frame_info should | |
181 | be weak in this file if at all possible. */ | |
182 | extern void __register_frame_info (const void *, struct object *) | |
183 | TARGET_ATTRIBUTE_WEAK; | |
184 | extern void __register_frame_info_bases (const void *, struct object *, | |
185 | void *, void *) | |
186 | TARGET_ATTRIBUTE_WEAK; | |
187 | extern void *__deregister_frame_info (const void *) | |
188 | TARGET_ATTRIBUTE_WEAK; | |
189 | extern void *__deregister_frame_info_bases (const void *) | |
190 | TARGET_ATTRIBUTE_WEAK; | |
191 | extern void __do_global_ctors_1 (void); | |
192 | ||
193 | /* Likewise for transactional memory clone tables. */ | |
194 | extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK; | |
195 | extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK; | |
196 | ||
197 | #ifdef OBJECT_FORMAT_ELF | |
198 | ||
199 | /* Declare a pointer to void function type. */ | |
200 | typedef void (*func_ptr) (void); | |
201 | #define STATIC static | |
202 | ||
203 | #else /* OBJECT_FORMAT_ELF */ | |
204 | ||
205 | #include "gbl-ctors.h" | |
206 | ||
207 | #define STATIC | |
208 | ||
209 | #endif /* OBJECT_FORMAT_ELF */ | |
210 | ||
211 | #ifdef CRT_BEGIN | |
212 | ||
213 | /* NOTE: In order to be able to support SVR4 shared libraries, we arrange | |
214 | to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__, | |
215 | __DTOR_END__ } per root executable and also one set of these symbols | |
216 | per shared library. So in any given whole process image, we may have | |
217 | multiple definitions of each of these symbols. In order to prevent | |
218 | these definitions from conflicting with one another, and in order to | |
219 | ensure that the proper lists are used for the initialization/finalization | |
220 | of each individual shared library (respectively), we give these symbols | |
221 | only internal (i.e. `static') linkage, and we also make it a point to | |
222 | refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__ | |
223 | symbol in crtbegin.o, where they are defined. */ | |
224 | ||
225 | /* No need for .ctors/.dtors section if linker can place them in | |
226 | .init_array/.fini_array section. */ | |
227 | #ifndef USE_INITFINI_ARRAY | |
228 | /* The -1 is a flag to __do_global_[cd]tors indicating that this table | |
229 | does not start with a count of elements. */ | |
230 | #ifdef CTOR_LIST_BEGIN | |
231 | CTOR_LIST_BEGIN; | |
232 | #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__) | |
233 | /* Hack: force cc1 to switch to .data section early, so that assembling | |
234 | __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */ | |
235 | static func_ptr force_to_data[1] __attribute__ ((__used__)) = { }; | |
236 | asm (__LIBGCC_CTORS_SECTION_ASM_OP__); | |
237 | STATIC func_ptr __CTOR_LIST__[1] | |
238 | __attribute__ ((__used__, aligned(__alignof__(func_ptr)))) | |
239 | = { (func_ptr) (-1) }; | |
240 | #else | |
241 | STATIC func_ptr __CTOR_LIST__[1] | |
242 | __attribute__ ((__used__, section(".ctors"), aligned(__alignof__(func_ptr)))) | |
243 | = { (func_ptr) (-1) }; | |
244 | #endif /* __CTOR_LIST__ alternatives */ | |
245 | ||
246 | #ifdef DTOR_LIST_BEGIN | |
247 | DTOR_LIST_BEGIN; | |
248 | #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__) | |
249 | asm (__LIBGCC_DTORS_SECTION_ASM_OP__); | |
250 | STATIC func_ptr __DTOR_LIST__[1] | |
251 | __attribute__ ((aligned(__alignof__(func_ptr)))) | |
252 | = { (func_ptr) (-1) }; | |
253 | #else | |
254 | STATIC func_ptr __DTOR_LIST__[1] | |
255 | __attribute__((section(".dtors"), aligned(__alignof__(func_ptr)))) | |
256 | = { (func_ptr) (-1) }; | |
257 | #endif /* __DTOR_LIST__ alternatives */ | |
258 | #endif /* USE_INITFINI_ARRAY */ | |
259 | ||
260 | #ifdef USE_EH_FRAME_REGISTRY | |
261 | /* Stick a label at the beginning of the frame unwind info so we can register | |
262 | and deregister it with the exception handling library code. */ | |
263 | STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[] | |
264 | __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), | |
265 | aligned(__alignof__ (void *)))) | |
266 | = { }; | |
267 | #endif /* USE_EH_FRAME_REGISTRY */ | |
268 | ||
269 | #if USE_TM_CLONE_REGISTRY | |
270 | STATIC func_ptr __TMC_LIST__[] | |
271 | __attribute__((used, section(".tm_clone_table"), aligned(__alignof__(void*)))) | |
272 | = { }; | |
273 | # ifdef HAVE_GAS_HIDDEN | |
274 | extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden"))); | |
275 | # endif | |
276 | ||
277 | static inline void | |
278 | deregister_tm_clones (void) | |
279 | { | |
280 | void (*fn) (void *); | |
281 | ||
282 | #ifdef HAVE_GAS_HIDDEN | |
283 | func_ptr *end = __TMC_END__; | |
284 | // Do not optimize the comparison to false. | |
285 | __asm ("" : "+g" (end)); | |
286 | if (__TMC_LIST__ == end) | |
287 | return; | |
288 | #else | |
289 | if (__TMC_LIST__[0] == NULL) | |
290 | return; | |
291 | #endif | |
292 | ||
293 | fn = _ITM_deregisterTMCloneTable; | |
294 | __asm ("" : "+r" (fn)); | |
295 | if (fn) | |
296 | fn (__TMC_LIST__); | |
297 | } | |
298 | ||
299 | static inline void | |
300 | register_tm_clones (void) | |
301 | { | |
302 | void (*fn) (void *, size_t); | |
303 | size_t size; | |
304 | ||
305 | #ifdef HAVE_GAS_HIDDEN | |
306 | func_ptr *end = __TMC_END__; | |
307 | // Do not optimize the comparison to false. | |
308 | __asm ("" : "+g" (end)); | |
309 | size = (end - __TMC_LIST__) / 2; | |
310 | #else | |
311 | for (size = 0; __TMC_LIST__[size * 2] != NULL; size++) | |
312 | continue; | |
313 | #endif | |
314 | if (size == 0) | |
315 | return; | |
316 | ||
317 | fn = _ITM_registerTMCloneTable; | |
318 | __asm ("" : "+r" (fn)); | |
319 | if (fn) | |
320 | fn (__TMC_LIST__, size); | |
321 | } | |
322 | #endif /* USE_TM_CLONE_REGISTRY */ | |
323 | ||
324 | #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \ | |
325 | || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__) | |
326 | ||
327 | #ifdef OBJECT_FORMAT_ELF | |
328 | ||
329 | #if DEFAULT_USE_CXA_ATEXIT | |
330 | /* Declare the __dso_handle variable. It should have a unique value | |
331 | in every shared-object; in a main program its value is zero. The | |
332 | object should in any case be protected. This means the instance | |
333 | in one DSO or the main program is not used in another object. The | |
334 | dynamic linker takes care of this. | |
335 | If __cxa_atexit is not being used, __dso_handle will not be used and | |
336 | doesn't need to be defined. */ | |
337 | ||
338 | #ifdef TARGET_LIBGCC_SDATA_SECTION | |
339 | extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION))); | |
340 | #endif | |
341 | #ifdef HAVE_GAS_HIDDEN | |
342 | extern void *__dso_handle __attribute__ ((__visibility__ ("hidden"))); | |
343 | #endif | |
344 | #ifdef CRTSTUFFS_O | |
345 | void *__dso_handle = &__dso_handle; | |
346 | #else | |
347 | void *__dso_handle = 0; | |
348 | #endif | |
349 | #endif /* DEFAULT_USE_CXA_ATEXIT */ | |
350 | ||
351 | /* The __cxa_finalize function may not be available so we use only a | |
352 | weak declaration. */ | |
353 | extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK; | |
354 | ||
355 | /* Run all the global destructors on exit from the program. */ | |
356 | ||
357 | /* Some systems place the number of pointers in the first word of the | |
358 | table. On SVR4 however, that word is -1. In all cases, the table is | |
359 | null-terminated. On SVR4, we start from the beginning of the list and | |
360 | invoke each per-compilation-unit destructor routine in order | |
361 | until we find that null. | |
362 | ||
363 | Note that this function MUST be static. There will be one of these | |
364 | functions in each root executable and one in each shared library, but | |
365 | although they all have the same code, each one is unique in that it | |
366 | refers to one particular associated `__DTOR_LIST__' which belongs to the | |
367 | same particular root executable or shared library file. | |
368 | ||
369 | On some systems, this routine is run more than once from the .fini, | |
370 | when exit is called recursively, so we arrange to remember where in | |
371 | the list we left off processing, and we resume at that point, | |
372 | should we be re-invoked. | |
373 | ||
374 | This routine does not need to be run if none of the following clauses are | |
375 | true, as it will not do anything, so can be removed. */ | |
376 | #if defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP) \ | |
377 | || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY) | |
378 | static void __attribute__((used)) | |
379 | __do_global_dtors_aux (void) | |
380 | { | |
381 | static _Bool completed; | |
382 | ||
383 | if (__builtin_expect (completed, 0)) | |
384 | return; | |
385 | ||
386 | #if DEFAULT_USE_CXA_ATEXIT | |
387 | #ifdef CRTSTUFFS_O | |
388 | if (__cxa_finalize) | |
389 | __cxa_finalize (__dso_handle); | |
390 | #endif | |
391 | #endif | |
392 | ||
393 | #ifdef FINI_ARRAY_SECTION_ASM_OP | |
394 | /* If we are using .fini_array then destructors will be run via that | |
395 | mechanism. */ | |
396 | #elif defined(HIDDEN_DTOR_LIST_END) | |
397 | { | |
398 | /* Safer version that makes sure only .dtors function pointers are | |
399 | called even if the static variable is maliciously changed. */ | |
400 | extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden"))); | |
401 | static size_t dtor_idx; | |
402 | const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1; | |
403 | func_ptr *dtor_list; | |
404 | ||
405 | __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__)); | |
406 | while (dtor_idx < max_idx) | |
407 | dtor_list[++dtor_idx] (); | |
408 | } | |
409 | #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */ | |
410 | { | |
411 | static func_ptr *p = __DTOR_LIST__ + 1; | |
412 | func_ptr f; | |
413 | ||
414 | while ((f = *p)) | |
415 | { | |
416 | p++; | |
417 | f (); | |
418 | } | |
419 | } | |
420 | #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */ | |
421 | ||
422 | #if USE_TM_CLONE_REGISTRY | |
423 | deregister_tm_clones (); | |
424 | #endif /* USE_TM_CLONE_REGISTRY */ | |
425 | ||
426 | #ifdef USE_EH_FRAME_REGISTRY | |
427 | #ifdef CRT_GET_RFIB_DATA | |
428 | /* If we used the new __register_frame_info_bases interface, | |
429 | make sure that we deregister from the same place. */ | |
430 | if (__deregister_frame_info_bases) | |
431 | __deregister_frame_info_bases (__EH_FRAME_BEGIN__); | |
432 | #else | |
433 | if (__deregister_frame_info) | |
434 | __deregister_frame_info (__EH_FRAME_BEGIN__); | |
435 | #endif | |
436 | #endif | |
437 | ||
438 | completed = 1; | |
439 | } | |
440 | ||
441 | /* Stick a call to __do_global_dtors_aux into the .fini section. */ | |
442 | #ifdef FINI_SECTION_ASM_OP | |
443 | CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux) | |
444 | #elif defined (FINI_ARRAY_SECTION_ASM_OP) | |
445 | #if defined(__FDPIC__) | |
446 | __asm__("\t.equ\t__do_global_dtors_aux_alias, __do_global_dtors_aux\n"); | |
447 | extern char __do_global_dtors_aux_alias; | |
448 | static void *__do_global_dtors_aux_fini_array_entry[] | |
449 | __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(void *)))) | |
450 | = { &__do_global_dtors_aux_alias }; | |
451 | #else /* defined(__FDPIC__) */ | |
452 | static func_ptr __do_global_dtors_aux_fini_array_entry[] | |
453 | __attribute__ ((__used__, section(".fini_array"), | |
454 | aligned(__alignof__(func_ptr)))) = { __do_global_dtors_aux }; | |
455 | #endif /* defined(__FDPIC__) */ | |
456 | #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */ | |
457 | static void __attribute__((used)) | |
458 | __do_global_dtors_aux_1 (void) | |
459 | { | |
460 | atexit (__do_global_dtors_aux); | |
461 | } | |
462 | CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, | |
463 | __do_global_dtors_aux_1) | |
464 | #endif | |
465 | #endif /* defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP) | |
466 | || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY) */ | |
467 | ||
468 | #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY | |
469 | /* Stick a call to __register_frame_info into the .init section. For some | |
470 | reason calls with no arguments work more reliably in .init, so stick the | |
471 | call in another function. */ | |
472 | ||
473 | static void __attribute__((used)) | |
474 | frame_dummy (void) | |
475 | { | |
476 | #ifdef USE_EH_FRAME_REGISTRY | |
477 | static struct object object; | |
478 | #ifdef CRT_GET_RFIB_DATA | |
479 | void *tbase, *dbase; | |
480 | tbase = 0; | |
481 | CRT_GET_RFIB_DATA (dbase); | |
482 | if (__register_frame_info_bases) | |
483 | __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase); | |
484 | #else | |
485 | if (__register_frame_info) | |
486 | __register_frame_info (__EH_FRAME_BEGIN__, &object); | |
487 | #endif /* CRT_GET_RFIB_DATA */ | |
488 | #endif /* USE_EH_FRAME_REGISTRY */ | |
489 | ||
490 | #if USE_TM_CLONE_REGISTRY | |
491 | register_tm_clones (); | |
492 | #endif /* USE_TM_CLONE_REGISTRY */ | |
493 | } | |
494 | ||
495 | #ifdef __LIBGCC_INIT_SECTION_ASM_OP__ | |
496 | CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy) | |
497 | #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */ | |
498 | #if defined(__FDPIC__) | |
499 | __asm__("\t.equ\t__frame_dummy_alias, frame_dummy\n"); | |
500 | extern char __frame_dummy_alias; | |
501 | static void *__frame_dummy_init_array_entry[] | |
502 | __attribute__ ((__used__, section(".init_array"), aligned(sizeof(void *)))) | |
503 | = { &__frame_dummy_alias }; | |
504 | #else /* defined(__FDPIC__) */ | |
505 | static func_ptr __frame_dummy_init_array_entry[] | |
506 | __attribute__ ((__used__, section(".init_array"), | |
507 | aligned(__alignof__(func_ptr)))) = { frame_dummy }; | |
508 | #endif /* defined(__FDPIC__) */ | |
509 | #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */ | |
510 | #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */ | |
511 | ||
512 | #else /* OBJECT_FORMAT_ELF */ | |
513 | ||
514 | /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o | |
515 | and once in crtend.o). It must be declared static to avoid a link | |
516 | error. Here, we define __do_global_ctors as an externally callable | |
517 | function. It is externally callable so that __main can invoke it when | |
518 | INVOKE__main is defined. This has the additional effect of forcing cc1 | |
519 | to switch to the .text section. */ | |
520 | ||
521 | static void __do_global_ctors_aux (void); | |
522 | void | |
523 | __do_global_ctors (void) | |
524 | { | |
525 | #ifdef INVOKE__main | |
526 | /* If __main won't actually call __do_global_ctors then it doesn't matter | |
527 | what's inside the function. The inside of __do_global_ctors_aux is | |
528 | called automatically in that case. And the Alliant fx2800 linker | |
529 | crashes on this reference. So prevent the crash. */ | |
530 | __do_global_ctors_aux (); | |
531 | #endif | |
532 | } | |
533 | ||
534 | asm (__LIBGCC_INIT_SECTION_ASM_OP__); /* cc1 doesn't know that we are switching! */ | |
535 | ||
536 | /* A routine to invoke all of the global constructors upon entry to the | |
537 | program. We put this into the .init section (for systems that have | |
538 | such a thing) so that we can properly perform the construction of | |
539 | file-scope static-storage C++ objects within shared libraries. */ | |
540 | ||
541 | static void __attribute__((used)) | |
542 | __do_global_ctors_aux (void) /* prologue goes in .init section */ | |
543 | { | |
544 | FORCE_CODE_SECTION_ALIGN /* explicit align before switch to .text */ | |
545 | asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */ | |
546 | DO_GLOBAL_CTORS_BODY; | |
547 | atexit (__do_global_dtors); | |
548 | } | |
549 | ||
550 | #endif /* OBJECT_FORMAT_ELF */ | |
551 | ||
552 | #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ | |
553 | ||
554 | extern void __do_global_dtors (void); | |
555 | ||
556 | /* This case is used by the Irix 6 port, which supports named sections but | |
557 | not an SVR4-style .fini section. __do_global_dtors can be non-static | |
558 | in this case because we protect it with -hidden_symbol. */ | |
559 | ||
560 | void | |
561 | __do_global_dtors (void) | |
562 | { | |
563 | func_ptr *p, f; | |
564 | for (p = __DTOR_LIST__ + 1; (f = *p); p++) | |
565 | f (); | |
566 | ||
567 | #if USE_TM_CLONE_REGISTRY | |
568 | deregister_tm_clones (); | |
569 | #endif /* USE_TM_CLONE_REGISTRY */ | |
570 | ||
571 | #ifdef USE_EH_FRAME_REGISTRY | |
572 | if (__deregister_frame_info) | |
573 | __deregister_frame_info (__EH_FRAME_BEGIN__); | |
574 | #endif | |
575 | } | |
576 | ||
577 | #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY | |
578 | /* A helper function for __do_global_ctors, which is in crtend.o. Here | |
579 | in crtbegin.o, we can reference a couple of symbols not visible there. | |
580 | Plus, since we're before libgcc.a, we have no problems referencing | |
581 | functions from there. */ | |
582 | void | |
583 | __do_global_ctors_1(void) | |
584 | { | |
585 | #ifdef USE_EH_FRAME_REGISTRY | |
586 | static struct object object; | |
587 | if (__register_frame_info) | |
588 | __register_frame_info (__EH_FRAME_BEGIN__, &object); | |
589 | #endif | |
590 | ||
591 | #if USE_TM_CLONE_REGISTRY | |
592 | register_tm_clones (); | |
593 | #endif /* USE_TM_CLONE_REGISTRY */ | |
594 | } | |
595 | #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */ | |
596 | ||
597 | #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ | |
598 | #error "What are you doing with crtstuff.c, then?" | |
599 | #endif | |
600 | ||
601 | #elif defined(CRT_END) /* ! CRT_BEGIN */ | |
602 | ||
603 | /* No need for .ctors/.dtors section if linker can place them in | |
604 | .init_array/.fini_array section. */ | |
605 | #ifndef USE_INITFINI_ARRAY | |
606 | /* Put a word containing zero at the end of each of our two lists of function | |
607 | addresses. Note that the words defined here go into the .ctors and .dtors | |
608 | sections of the crtend.o file, and since that file is always linked in | |
609 | last, these words naturally end up at the very ends of the two lists | |
610 | contained in these two sections. */ | |
611 | ||
612 | #ifdef CTOR_LIST_END | |
613 | CTOR_LIST_END; | |
614 | #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__) | |
615 | /* Hack: force cc1 to switch to .data section early, so that assembling | |
616 | __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */ | |
617 | static func_ptr force_to_data[1] __attribute__ ((__used__)) = { }; | |
618 | asm (__LIBGCC_CTORS_SECTION_ASM_OP__); | |
619 | STATIC func_ptr __CTOR_END__[1] | |
620 | __attribute__((aligned(__alignof__(func_ptr)))) | |
621 | = { (func_ptr) 0 }; | |
622 | #else | |
623 | STATIC func_ptr __CTOR_END__[1] | |
624 | __attribute__((section(".ctors"), aligned(__alignof__(func_ptr)))) | |
625 | = { (func_ptr) 0 }; | |
626 | #endif | |
627 | ||
628 | #ifdef DTOR_LIST_END | |
629 | DTOR_LIST_END; | |
630 | #elif defined(HIDDEN_DTOR_LIST_END) | |
631 | #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__ | |
632 | asm (__LIBGCC_DTORS_SECTION_ASM_OP__); | |
633 | #endif | |
634 | func_ptr __DTOR_END__[1] | |
635 | __attribute__ ((used, | |
636 | #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__ | |
637 | section(".dtors"), | |
638 | #endif | |
639 | aligned(__alignof__(func_ptr)), visibility ("hidden"))) | |
640 | = { (func_ptr) 0 }; | |
641 | #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__) | |
642 | asm (__LIBGCC_DTORS_SECTION_ASM_OP__); | |
643 | STATIC func_ptr __DTOR_END__[1] | |
644 | __attribute__ ((used, aligned(__alignof__(func_ptr)))) | |
645 | = { (func_ptr) 0 }; | |
646 | #else | |
647 | STATIC func_ptr __DTOR_END__[1] | |
648 | __attribute__((used, section(".dtors"), aligned(__alignof__(func_ptr)))) | |
649 | = { (func_ptr) 0 }; | |
650 | #endif | |
651 | #endif /* USE_INITFINI_ARRAY */ | |
652 | ||
653 | #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__ | |
654 | /* Terminate the frame unwind info section with a 4byte 0 as a sentinel; | |
655 | this would be the 'length' field in a real FDE. */ | |
656 | # if __INT_MAX__ == 2147483647 | |
657 | typedef int int32; | |
658 | # elif __LONG_MAX__ == 2147483647 | |
659 | typedef long int32; | |
660 | # elif __SHRT_MAX__ == 2147483647 | |
661 | typedef short int32; | |
662 | # else | |
663 | # error "Missing a 4 byte integer" | |
664 | # endif | |
665 | STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[] | |
666 | __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__), | |
667 | aligned(__alignof__(int32)))) | |
668 | = { 0 }; | |
669 | #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */ | |
670 | ||
671 | #if USE_TM_CLONE_REGISTRY | |
672 | # ifndef HAVE_GAS_HIDDEN | |
673 | static | |
674 | # endif | |
675 | func_ptr __TMC_END__[] | |
676 | __attribute__((used, section(".tm_clone_table"), | |
677 | aligned(__alignof__(void *)))) | |
678 | # ifdef HAVE_GAS_HIDDEN | |
679 | __attribute__((__visibility__ ("hidden"))) = { }; | |
680 | # else | |
681 | = { 0, 0 }; | |
682 | # endif | |
683 | #endif /* USE_TM_CLONE_REGISTRY */ | |
684 | ||
685 | #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__ | |
686 | ||
687 | /* If we are using .init_array, there is nothing to do. */ | |
688 | ||
689 | #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__) | |
690 | ||
691 | #ifdef OBJECT_FORMAT_ELF | |
692 | static void __attribute__((used)) | |
693 | __do_global_ctors_aux (void) | |
694 | { | |
695 | func_ptr *p; | |
696 | for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) | |
697 | (*p) (); | |
698 | } | |
699 | ||
700 | /* Stick a call to __do_global_ctors_aux into the .init section. */ | |
701 | CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux) | |
702 | #else /* OBJECT_FORMAT_ELF */ | |
703 | ||
704 | /* Stick the real initialization code, followed by a normal sort of | |
705 | function epilogue at the very end of the .init section for this | |
706 | entire root executable file or for this entire shared library file. | |
707 | ||
708 | Note that we use some tricks here to get *just* the body and just | |
709 | a function epilogue (but no function prologue) into the .init | |
710 | section of the crtend.o file. Specifically, we switch to the .text | |
711 | section, start to define a function, and then we switch to the .init | |
712 | section just before the body code. | |
713 | ||
714 | Earlier on, we put the corresponding function prologue into the .init | |
715 | section of the crtbegin.o file (which will be linked in first). | |
716 | ||
717 | Note that we want to invoke all constructors for C++ file-scope static- | |
718 | storage objects AFTER any other possible initialization actions which | |
719 | may be performed by the code in the .init section contributions made by | |
720 | other libraries, etc. That's because those other initializations may | |
721 | include setup operations for very primitive things (e.g. initializing | |
722 | the state of the floating-point coprocessor, etc.) which should be done | |
723 | before we start to execute any of the user's code. */ | |
724 | ||
725 | static void | |
726 | __do_global_ctors_aux (void) /* prologue goes in .text section */ | |
727 | { | |
728 | asm (__LIBGCC_INIT_SECTION_ASM_OP__); | |
729 | DO_GLOBAL_CTORS_BODY; | |
730 | atexit (__do_global_dtors); | |
731 | } /* epilogue and body go in .init section */ | |
732 | ||
733 | FORCE_CODE_SECTION_ALIGN | |
734 | asm (__LIBGCC_TEXT_SECTION_ASM_OP__); | |
735 | ||
736 | #endif /* OBJECT_FORMAT_ELF */ | |
737 | ||
738 | #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ | |
739 | ||
740 | extern void __do_global_ctors (void); | |
741 | ||
742 | /* This case is used by the Irix 6 port, which supports named sections but | |
743 | not an SVR4-style .init section. __do_global_ctors can be non-static | |
744 | in this case because we protect it with -hidden_symbol. */ | |
745 | void | |
746 | __do_global_ctors (void) | |
747 | { | |
748 | func_ptr *p; | |
749 | #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY | |
750 | __do_global_ctors_1(); | |
751 | #endif | |
752 | for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) | |
753 | (*p) (); | |
754 | } | |
755 | ||
756 | #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ | |
757 | #error "What are you doing with crtstuff.c, then?" | |
758 | #endif | |
759 | ||
760 | #else /* ! CRT_BEGIN && ! CRT_END */ | |
761 | #error "One of CRT_BEGIN or CRT_END must be defined." | |
762 | #endif |