1 /* Specialized bits of code needed to support construction and
2 destruction of file-scope objects in C++ code.
3 Copyright (C) 1991-2020 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__), aligned(4)))
265 = { };
266 #endif /* USE_EH_FRAME_REGISTRY */
267
268 #if USE_TM_CLONE_REGISTRY
269 STATIC func_ptr __TMC_LIST__[]
270 __attribute__((used, section(".tm_clone_table"), aligned(__alignof__(void*))))
271 = { };
272 # ifdef HAVE_GAS_HIDDEN
273 extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
274 # endif
275
276 static inline void
deregister_tm_clones(void)277 deregister_tm_clones (void)
278 {
279 void (*fn) (void *);
280
281 #ifdef HAVE_GAS_HIDDEN
282 func_ptr *end = __TMC_END__;
283 // Do not optimize the comparison to false.
284 __asm ("" : "+g" (end));
285 if (__TMC_LIST__ == end)
286 return;
287 #else
288 if (__TMC_LIST__[0] == NULL)
289 return;
290 #endif
291
292 fn = _ITM_deregisterTMCloneTable;
293 __asm ("" : "+r" (fn));
294 if (fn)
295 fn (__TMC_LIST__);
296 }
297
298 static inline void
register_tm_clones(void)299 register_tm_clones (void)
300 {
301 void (*fn) (void *, size_t);
302 size_t size;
303
304 #ifdef HAVE_GAS_HIDDEN
305 func_ptr *end = __TMC_END__;
306 // Do not optimize the comparison to false.
307 __asm ("" : "+g" (end));
308 size = (end - __TMC_LIST__) / 2;
309 #else
310 for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
311 continue;
312 #endif
313 if (size == 0)
314 return;
315
316 fn = _ITM_registerTMCloneTable;
317 __asm ("" : "+r" (fn));
318 if (fn)
319 fn (__TMC_LIST__, size);
320 }
321 #endif /* USE_TM_CLONE_REGISTRY */
322
323 #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
324 || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
325
326 #ifdef OBJECT_FORMAT_ELF
327
328 #if DEFAULT_USE_CXA_ATEXIT
329 /* Declare the __dso_handle variable. It should have a unique value
330 in every shared-object; in a main program its value is zero. The
331 object should in any case be protected. This means the instance
332 in one DSO or the main program is not used in another object. The
333 dynamic linker takes care of this.
334 If __cxa_atexit is not being used, __dso_handle will not be used and
335 doesn't need to be defined. */
336
337 #ifdef TARGET_LIBGCC_SDATA_SECTION
338 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
339 #endif
340 #ifdef HAVE_GAS_HIDDEN
341 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
342 #endif
343 #ifdef CRTSTUFFS_O
344 void *__dso_handle = &__dso_handle;
345 #else
346 void *__dso_handle = 0;
347 #endif
348 #endif /* DEFAULT_USE_CXA_ATEXIT */
349
350 /* The __cxa_finalize function may not be available so we use only a
351 weak declaration. */
352 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
353
354 /* Run all the global destructors on exit from the program. */
355
356 /* Some systems place the number of pointers in the first word of the
357 table. On SVR4 however, that word is -1. In all cases, the table is
358 null-terminated. On SVR4, we start from the beginning of the list and
359 invoke each per-compilation-unit destructor routine in order
360 until we find that null.
361
362 Note that this function MUST be static. There will be one of these
363 functions in each root executable and one in each shared library, but
364 although they all have the same code, each one is unique in that it
365 refers to one particular associated `__DTOR_LIST__' which belongs to the
366 same particular root executable or shared library file.
367
368 On some systems, this routine is run more than once from the .fini,
369 when exit is called recursively, so we arrange to remember where in
370 the list we left off processing, and we resume at that point,
371 should we be re-invoked.
372
373 This routine does not need to be run if none of the following clauses are
374 true, as it will not do anything, so can be removed. */
375 #if defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP) \
376 || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY)
377 static void __attribute__((used))
__do_global_dtors_aux(void)378 __do_global_dtors_aux (void)
379 {
380 static _Bool completed;
381
382 if (__builtin_expect (completed, 0))
383 return;
384
385 #if DEFAULT_USE_CXA_ATEXIT
386 #ifdef CRTSTUFFS_O
387 if (__cxa_finalize)
388 __cxa_finalize (__dso_handle);
389 #endif
390 #endif
391
392 #ifdef FINI_ARRAY_SECTION_ASM_OP
393 /* If we are using .fini_array then destructors will be run via that
394 mechanism. */
395 #elif defined(HIDDEN_DTOR_LIST_END)
396 {
397 /* Safer version that makes sure only .dtors function pointers are
398 called even if the static variable is maliciously changed. */
399 extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
400 static size_t dtor_idx;
401 const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
402 func_ptr *dtor_list;
403
404 __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__));
405 while (dtor_idx < max_idx)
406 dtor_list[++dtor_idx] ();
407 }
408 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
409 {
410 static func_ptr *p = __DTOR_LIST__ + 1;
411 func_ptr f;
412
413 while ((f = *p))
414 {
415 p++;
416 f ();
417 }
418 }
419 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
420
421 #if USE_TM_CLONE_REGISTRY
422 deregister_tm_clones ();
423 #endif /* USE_TM_CLONE_REGISTRY */
424
425 #ifdef USE_EH_FRAME_REGISTRY
426 #ifdef CRT_GET_RFIB_DATA
427 /* If we used the new __register_frame_info_bases interface,
428 make sure that we deregister from the same place. */
429 if (__deregister_frame_info_bases)
430 __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
431 #else
432 if (__deregister_frame_info)
433 __deregister_frame_info (__EH_FRAME_BEGIN__);
434 #endif
435 #endif
436
437 completed = 1;
438 }
439
440 /* Stick a call to __do_global_dtors_aux into the .fini section. */
441 #ifdef FINI_SECTION_ASM_OP
CRT_CALL_STATIC_FUNCTION(FINI_SECTION_ASM_OP,__do_global_dtors_aux)442 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
443 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
444 #if defined(__FDPIC__)
445 __asm__("\t.equ\t__do_global_dtors_aux_alias, __do_global_dtors_aux\n");
446 extern char __do_global_dtors_aux_alias;
447 static void *__do_global_dtors_aux_fini_array_entry[]
448 __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(void *))))
449 = { &__do_global_dtors_aux_alias };
450 #else /* defined(__FDPIC__) */
451 static func_ptr __do_global_dtors_aux_fini_array_entry[]
452 __attribute__ ((__used__, section(".fini_array"),
453 aligned(__alignof__(func_ptr)))) = { __do_global_dtors_aux };
454 #endif /* defined(__FDPIC__) */
455 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
456 static void __attribute__((used))
457 __do_global_dtors_aux_1 (void)
458 {
459 atexit (__do_global_dtors_aux);
460 }
461 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
462 __do_global_dtors_aux_1)
463 #endif
464 #endif /* defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP)
465 || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY) */
466
467 #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
468 /* Stick a call to __register_frame_info into the .init section. For some
469 reason calls with no arguments work more reliably in .init, so stick the
470 call in another function. */
471
472 static void __attribute__((used))
473 frame_dummy (void)
474 {
475 #ifdef USE_EH_FRAME_REGISTRY
476 static struct object object;
477 #ifdef CRT_GET_RFIB_DATA
478 void *tbase, *dbase;
479 tbase = 0;
480 CRT_GET_RFIB_DATA (dbase);
481 if (__register_frame_info_bases)
482 __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
483 #else
484 if (__register_frame_info)
485 __register_frame_info (__EH_FRAME_BEGIN__, &object);
486 #endif /* CRT_GET_RFIB_DATA */
487 #endif /* USE_EH_FRAME_REGISTRY */
488
489 #if USE_TM_CLONE_REGISTRY
490 register_tm_clones ();
491 #endif /* USE_TM_CLONE_REGISTRY */
492 }
493
494 #ifdef __LIBGCC_INIT_SECTION_ASM_OP__
495 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
496 #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
497 #if defined(__FDPIC__)
498 __asm__("\t.equ\t__frame_dummy_alias, frame_dummy\n");
499 extern char __frame_dummy_alias;
500 static void *__frame_dummy_init_array_entry[]
501 __attribute__ ((__used__, section(".init_array"), aligned(sizeof(void *))))
502 = { &__frame_dummy_alias };
503 #else /* defined(__FDPIC__) */
504 static func_ptr __frame_dummy_init_array_entry[]
505 __attribute__ ((__used__, section(".init_array"),
506 aligned(__alignof__(func_ptr)))) = { frame_dummy };
507 #endif /* defined(__FDPIC__) */
508 #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
509 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
510
511 #else /* OBJECT_FORMAT_ELF */
512
513 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
514 and once in crtend.o). It must be declared static to avoid a link
515 error. Here, we define __do_global_ctors as an externally callable
516 function. It is externally callable so that __main can invoke it when
517 INVOKE__main is defined. This has the additional effect of forcing cc1
518 to switch to the .text section. */
519
520 static void __do_global_ctors_aux (void);
521 void
522 __do_global_ctors (void)
523 {
524 #ifdef INVOKE__main
525 /* If __main won't actually call __do_global_ctors then it doesn't matter
526 what's inside the function. The inside of __do_global_ctors_aux is
527 called automatically in that case. And the Alliant fx2800 linker
528 crashes on this reference. So prevent the crash. */
529 __do_global_ctors_aux ();
530 #endif
531 }
532
533 asm (__LIBGCC_INIT_SECTION_ASM_OP__); /* cc1 doesn't know that we are switching! */
534
535 /* A routine to invoke all of the global constructors upon entry to the
536 program. We put this into the .init section (for systems that have
537 such a thing) so that we can properly perform the construction of
538 file-scope static-storage C++ objects within shared libraries. */
539
540 static void __attribute__((used))
541 __do_global_ctors_aux (void) /* prologue goes in .init section */
542 {
543 FORCE_CODE_SECTION_ALIGN /* explicit align before switch to .text */
544 asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */
545 DO_GLOBAL_CTORS_BODY;
546 atexit (__do_global_dtors);
547 }
548
549 #endif /* OBJECT_FORMAT_ELF */
550
551 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
552
553 extern void __do_global_dtors (void);
554
555 /* This case is used by the Irix 6 port, which supports named sections but
556 not an SVR4-style .fini section. __do_global_dtors can be non-static
557 in this case because we protect it with -hidden_symbol. */
558
559 void
560 __do_global_dtors (void)
561 {
562 func_ptr *p, f;
563 for (p = __DTOR_LIST__ + 1; (f = *p); p++)
564 f ();
565
566 #if USE_TM_CLONE_REGISTRY
567 deregister_tm_clones ();
568 #endif /* USE_TM_CLONE_REGISTRY */
569
570 #ifdef USE_EH_FRAME_REGISTRY
571 if (__deregister_frame_info)
572 __deregister_frame_info (__EH_FRAME_BEGIN__);
573 #endif
574 }
575
576 #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
577 /* A helper function for __do_global_ctors, which is in crtend.o. Here
578 in crtbegin.o, we can reference a couple of symbols not visible there.
579 Plus, since we're before libgcc.a, we have no problems referencing
580 functions from there. */
581 void
582 __do_global_ctors_1(void)
583 {
584 #ifdef USE_EH_FRAME_REGISTRY
585 static struct object object;
586 if (__register_frame_info)
587 __register_frame_info (__EH_FRAME_BEGIN__, &object);
588 #endif
589
590 #if USE_TM_CLONE_REGISTRY
591 register_tm_clones ();
592 #endif /* USE_TM_CLONE_REGISTRY */
593 }
594 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
595
596 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
597 #error "What are you doing with crtstuff.c, then?"
598 #endif
599
600 #elif defined(CRT_END) /* ! CRT_BEGIN */
601
602 /* No need for .ctors/.dtors section if linker can place them in
603 .init_array/.fini_array section. */
604 #ifndef USE_INITFINI_ARRAY
605 /* Put a word containing zero at the end of each of our two lists of function
606 addresses. Note that the words defined here go into the .ctors and .dtors
607 sections of the crtend.o file, and since that file is always linked in
608 last, these words naturally end up at the very ends of the two lists
609 contained in these two sections. */
610
611 #ifdef CTOR_LIST_END
612 CTOR_LIST_END;
613 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
614 /* Hack: force cc1 to switch to .data section early, so that assembling
615 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */
616 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
617 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
618 STATIC func_ptr __CTOR_END__[1]
619 __attribute__((aligned(__alignof__(func_ptr))))
620 = { (func_ptr) 0 };
621 #else
622 STATIC func_ptr __CTOR_END__[1]
623 __attribute__((section(".ctors"), aligned(__alignof__(func_ptr))))
624 = { (func_ptr) 0 };
625 #endif
626
627 #ifdef DTOR_LIST_END
628 DTOR_LIST_END;
629 #elif defined(HIDDEN_DTOR_LIST_END)
630 #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
631 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
632 #endif
633 func_ptr __DTOR_END__[1]
634 __attribute__ ((used,
635 #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
636 section(".dtors"),
637 #endif
638 aligned(__alignof__(func_ptr)), visibility ("hidden")))
639 = { (func_ptr) 0 };
640 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
641 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
642 STATIC func_ptr __DTOR_END__[1]
643 __attribute__ ((used, aligned(__alignof__(func_ptr))))
644 = { (func_ptr) 0 };
645 #else
646 STATIC func_ptr __DTOR_END__[1]
647 __attribute__((used, section(".dtors"), aligned(__alignof__(func_ptr))))
648 = { (func_ptr) 0 };
649 #endif
650 #endif /* USE_INITFINI_ARRAY */
651
652 #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
653 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
654 this would be the 'length' field in a real FDE. */
655 # if __INT_MAX__ == 2147483647
656 typedef int int32;
657 # elif __LONG_MAX__ == 2147483647
658 typedef long int32;
659 # elif __SHRT_MAX__ == 2147483647
660 typedef short int32;
661 # else
662 # error "Missing a 4 byte integer"
663 # endif
664 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
665 __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
666 aligned(__alignof__(int32))))
667 = { 0 };
668 #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
669
670 #if USE_TM_CLONE_REGISTRY
671 # ifndef HAVE_GAS_HIDDEN
672 static
673 # endif
674 func_ptr __TMC_END__[]
675 __attribute__((used, section(".tm_clone_table"),
676 aligned(__alignof__(void *))))
677 # ifdef HAVE_GAS_HIDDEN
678 __attribute__((__visibility__ ("hidden"))) = { };
679 # else
680 = { 0, 0 };
681 # endif
682 #endif /* USE_TM_CLONE_REGISTRY */
683
684 #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
685
686 /* If we are using .init_array, there is nothing to do. */
687
688 #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
689
690 #ifdef OBJECT_FORMAT_ELF
691 static void __attribute__((used))
692 __do_global_ctors_aux (void)
693 {
694 func_ptr *p;
695 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
696 (*p) ();
697 }
698
699 /* Stick a call to __do_global_ctors_aux into the .init section. */
700 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
701 #else /* OBJECT_FORMAT_ELF */
702
703 /* Stick the real initialization code, followed by a normal sort of
704 function epilogue at the very end of the .init section for this
705 entire root executable file or for this entire shared library file.
706
707 Note that we use some tricks here to get *just* the body and just
708 a function epilogue (but no function prologue) into the .init
709 section of the crtend.o file. Specifically, we switch to the .text
710 section, start to define a function, and then we switch to the .init
711 section just before the body code.
712
713 Earlier on, we put the corresponding function prologue into the .init
714 section of the crtbegin.o file (which will be linked in first).
715
716 Note that we want to invoke all constructors for C++ file-scope static-
717 storage objects AFTER any other possible initialization actions which
718 may be performed by the code in the .init section contributions made by
719 other libraries, etc. That's because those other initializations may
720 include setup operations for very primitive things (e.g. initializing
721 the state of the floating-point coprocessor, etc.) which should be done
722 before we start to execute any of the user's code. */
723
724 static void
725 __do_global_ctors_aux (void) /* prologue goes in .text section */
726 {
727 asm (__LIBGCC_INIT_SECTION_ASM_OP__);
728 DO_GLOBAL_CTORS_BODY;
729 atexit (__do_global_dtors);
730 } /* epilogue and body go in .init section */
731
732 FORCE_CODE_SECTION_ALIGN
733 asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
734
735 #endif /* OBJECT_FORMAT_ELF */
736
737 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
738
739 extern void __do_global_ctors (void);
740
741 /* This case is used by the Irix 6 port, which supports named sections but
742 not an SVR4-style .init section. __do_global_ctors can be non-static
743 in this case because we protect it with -hidden_symbol. */
744 void
745 __do_global_ctors (void)
746 {
747 func_ptr *p;
748 #if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
749 __do_global_ctors_1();
750 #endif
751 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
752 (*p) ();
753 }
754
755 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
756 #error "What are you doing with crtstuff.c, then?"
757 #endif
758
759 #else /* ! CRT_BEGIN && ! CRT_END */
760 #error "One of CRT_BEGIN or CRT_END must be defined."
761 #endif
762