[PR c++/839888] Baselink tsubst ICE
[official-gcc.git] / libgcc / crtstuff.c
blob5e894455e16274a7e5a82f199b83db236d4c6529
1 /* Specialized bits of code needed to support construction and
2 destruction of file-scope objects in C++ code.
3 Copyright (C) 1991-2018 Free Software Foundation, Inc.
4 Contributed by Ron Guilmette (rfg@monkeys.com).
6 This file is part of GCC.
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.
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.
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.
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/>. */
27 /* This file is a bit like libgcc2.c in that it is compiled
28 multiple times and yields multiple .o files.
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.
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.
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.)
46 This file must be compiled with gcc. */
48 /* Target machine header files require this define. */
49 #define IN_LIBGCC2
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"
67 #ifndef FORCE_CODE_SECTION_ALIGN
68 # define FORCE_CODE_SECTION_ALIGN
69 #endif
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__); \
81 #endif
83 #if defined(TARGET_DL_ITERATE_PHDR) && \
84 (defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__))
85 #define BSD_DL_ITERATE_PHDR_AVAILABLE
86 #endif
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
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
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
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
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
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
154 #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
155 # define USE_TM_CLONE_REGISTRY 1
156 #endif
158 /* We do not want to add the weak attribute to the declarations of these
159 routines in unwind-dw2-fde.h because that will cause the definition of
160 these symbols to be weak as well.
162 This exposes a core issue, how to handle creating weak references vs
163 how to create weak definitions. Either we have to have the definition
164 of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
165 have a second declaration if we want a function's references to be weak,
166 but not its definition.
168 Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
169 one thinks about scaling to larger problems -- i.e., the condition under
170 which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
171 complicated.
173 So, we take an approach similar to #pragma weak -- we have a second
174 declaration for functions that we want to have weak references.
176 Neither way is particularly good. */
178 /* References to __register_frame_info and __deregister_frame_info should
179 be weak in this file if at all possible. */
180 extern void __register_frame_info (const void *, struct object *)
181 TARGET_ATTRIBUTE_WEAK;
182 extern void __register_frame_info_bases (const void *, struct object *,
183 void *, void *)
184 TARGET_ATTRIBUTE_WEAK;
185 extern void *__deregister_frame_info (const void *)
186 TARGET_ATTRIBUTE_WEAK;
187 extern void *__deregister_frame_info_bases (const void *)
188 TARGET_ATTRIBUTE_WEAK;
189 extern void __do_global_ctors_1 (void);
191 /* Likewise for _Jv_RegisterClasses. */
192 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
194 /* Likewise for transactional memory clone tables. */
195 extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
196 extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
198 #ifdef OBJECT_FORMAT_ELF
200 /* Declare a pointer to void function type. */
201 typedef void (*func_ptr) (void);
202 #define STATIC static
204 #else /* OBJECT_FORMAT_ELF */
206 #include "gbl-ctors.h"
208 #define STATIC
210 #endif /* OBJECT_FORMAT_ELF */
212 #ifdef CRT_BEGIN
214 /* NOTE: In order to be able to support SVR4 shared libraries, we arrange
215 to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
216 __DTOR_END__ } per root executable and also one set of these symbols
217 per shared library. So in any given whole process image, we may have
218 multiple definitions of each of these symbols. In order to prevent
219 these definitions from conflicting with one another, and in order to
220 ensure that the proper lists are used for the initialization/finalization
221 of each individual shared library (respectively), we give these symbols
222 only internal (i.e. `static') linkage, and we also make it a point to
223 refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
224 symbol in crtbegin.o, where they are defined. */
226 /* No need for .ctors/.dtors section if linker can place them in
227 .init_array/.fini_array section. */
228 #ifndef USE_INITFINI_ARRAY
229 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
230 does not start with a count of elements. */
231 #ifdef CTOR_LIST_BEGIN
232 CTOR_LIST_BEGIN;
233 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
234 /* Hack: force cc1 to switch to .data section early, so that assembling
235 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */
236 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
237 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
238 STATIC func_ptr __CTOR_LIST__[1]
239 __attribute__ ((__used__, aligned(sizeof(func_ptr))))
240 = { (func_ptr) (-1) };
241 #else
242 STATIC func_ptr __CTOR_LIST__[1]
243 __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
244 = { (func_ptr) (-1) };
245 #endif /* __CTOR_LIST__ alternatives */
247 #ifdef DTOR_LIST_BEGIN
248 DTOR_LIST_BEGIN;
249 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
250 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
251 STATIC func_ptr __DTOR_LIST__[1]
252 __attribute__ ((aligned(sizeof(func_ptr))))
253 = { (func_ptr) (-1) };
254 #else
255 STATIC func_ptr __DTOR_LIST__[1]
256 __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
257 = { (func_ptr) (-1) };
258 #endif /* __DTOR_LIST__ alternatives */
259 #endif /* USE_INITFINI_ARRAY */
261 #ifdef USE_EH_FRAME_REGISTRY
262 /* Stick a label at the beginning of the frame unwind info so we can register
263 and deregister it with the exception handling library code. */
264 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
265 __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4)))
266 = { };
267 #endif /* USE_EH_FRAME_REGISTRY */
269 #if USE_TM_CLONE_REGISTRY
270 STATIC func_ptr __TMC_LIST__[]
271 __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*))))
272 = { };
273 # ifdef HAVE_GAS_HIDDEN
274 extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
275 # endif
277 static inline void
278 deregister_tm_clones (void)
280 void (*fn) (void *);
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
293 fn = _ITM_deregisterTMCloneTable;
294 __asm ("" : "+r" (fn));
295 if (fn)
296 fn (__TMC_LIST__);
299 static inline void
300 register_tm_clones (void)
302 void (*fn) (void *, size_t);
303 size_t size;
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;
317 fn = _ITM_registerTMCloneTable;
318 __asm ("" : "+r" (fn));
319 if (fn)
320 fn (__TMC_LIST__, size);
322 #endif /* USE_TM_CLONE_REGISTRY */
324 #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
325 || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
327 #ifdef OBJECT_FORMAT_ELF
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. */
335 #ifdef TARGET_LIBGCC_SDATA_SECTION
336 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
337 #endif
338 #ifdef HAVE_GAS_HIDDEN
339 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
340 #endif
341 #ifdef CRTSTUFFS_O
342 void *__dso_handle = &__dso_handle;
343 #else
344 void *__dso_handle = 0;
345 #endif
347 /* The __cxa_finalize function may not be available so we use only a
348 weak declaration. */
349 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
351 /* Run all the global destructors on exit from the program. */
353 /* Some systems place the number of pointers in the first word of the
354 table. On SVR4 however, that word is -1. In all cases, the table is
355 null-terminated. On SVR4, we start from the beginning of the list and
356 invoke each per-compilation-unit destructor routine in order
357 until we find that null.
359 Note that this function MUST be static. There will be one of these
360 functions in each root executable and one in each shared library, but
361 although they all have the same code, each one is unique in that it
362 refers to one particular associated `__DTOR_LIST__' which belongs to the
363 same particular root executable or shared library file.
365 On some systems, this routine is run more than once from the .fini,
366 when exit is called recursively, so we arrange to remember where in
367 the list we left off processing, and we resume at that point,
368 should we be re-invoked. */
370 static void __attribute__((used))
371 __do_global_dtors_aux (void)
373 static _Bool completed;
375 if (__builtin_expect (completed, 0))
376 return;
378 #ifdef CRTSTUFFS_O
379 if (__cxa_finalize)
380 __cxa_finalize (__dso_handle);
381 #endif
383 #ifdef FINI_ARRAY_SECTION_ASM_OP
384 /* If we are using .fini_array then destructors will be run via that
385 mechanism. */
386 #elif defined(HIDDEN_DTOR_LIST_END)
388 /* Safer version that makes sure only .dtors function pointers are
389 called even if the static variable is maliciously changed. */
390 extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
391 static size_t dtor_idx;
392 const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
393 func_ptr *dtor_list;
395 __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__));
396 while (dtor_idx < max_idx)
397 dtor_list[++dtor_idx] ();
399 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
401 static func_ptr *p = __DTOR_LIST__ + 1;
402 func_ptr f;
404 while ((f = *p))
406 p++;
407 f ();
410 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
412 #if USE_TM_CLONE_REGISTRY
413 deregister_tm_clones ();
414 #endif /* USE_TM_CLONE_REGISTRY */
416 #ifdef USE_EH_FRAME_REGISTRY
417 #ifdef CRT_GET_RFIB_DATA
418 /* If we used the new __register_frame_info_bases interface,
419 make sure that we deregister from the same place. */
420 if (__deregister_frame_info_bases)
421 __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
422 #else
423 if (__deregister_frame_info)
424 __deregister_frame_info (__EH_FRAME_BEGIN__);
425 #endif
426 #endif
428 completed = 1;
431 /* Stick a call to __do_global_dtors_aux into the .fini section. */
432 #ifdef FINI_SECTION_ASM_OP
433 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
434 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
435 static func_ptr __do_global_dtors_aux_fini_array_entry[]
436 __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
437 = { __do_global_dtors_aux };
438 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
439 static void __attribute__((used))
440 __do_global_dtors_aux_1 (void)
442 atexit (__do_global_dtors_aux);
444 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
445 __do_global_dtors_aux_1)
446 #endif
448 #if defined(USE_EH_FRAME_REGISTRY) \
449 || defined(USE_TM_CLONE_REGISTRY)
450 /* Stick a call to __register_frame_info into the .init section. For some
451 reason calls with no arguments work more reliably in .init, so stick the
452 call in another function. */
454 static void __attribute__((used))
455 frame_dummy (void)
457 #ifdef USE_EH_FRAME_REGISTRY
458 static struct object object;
459 #ifdef CRT_GET_RFIB_DATA
460 void *tbase, *dbase;
461 tbase = 0;
462 CRT_GET_RFIB_DATA (dbase);
463 if (__register_frame_info_bases)
464 __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
465 #else
466 if (__register_frame_info)
467 __register_frame_info (__EH_FRAME_BEGIN__, &object);
468 #endif /* CRT_GET_RFIB_DATA */
469 #endif /* USE_EH_FRAME_REGISTRY */
471 #if USE_TM_CLONE_REGISTRY
472 register_tm_clones ();
473 #endif /* USE_TM_CLONE_REGISTRY */
476 #ifdef __LIBGCC_INIT_SECTION_ASM_OP__
477 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
478 #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
479 static func_ptr __frame_dummy_init_array_entry[]
480 __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
481 = { frame_dummy };
482 #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
483 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
485 #else /* OBJECT_FORMAT_ELF */
487 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
488 and once in crtend.o). It must be declared static to avoid a link
489 error. Here, we define __do_global_ctors as an externally callable
490 function. It is externally callable so that __main can invoke it when
491 INVOKE__main is defined. This has the additional effect of forcing cc1
492 to switch to the .text section. */
494 static void __do_global_ctors_aux (void);
495 void
496 __do_global_ctors (void)
498 #ifdef INVOKE__main
499 /* If __main won't actually call __do_global_ctors then it doesn't matter
500 what's inside the function. The inside of __do_global_ctors_aux is
501 called automatically in that case. And the Alliant fx2800 linker
502 crashes on this reference. So prevent the crash. */
503 __do_global_ctors_aux ();
504 #endif
507 asm (__LIBGCC_INIT_SECTION_ASM_OP__); /* cc1 doesn't know that we are switching! */
509 /* A routine to invoke all of the global constructors upon entry to the
510 program. We put this into the .init section (for systems that have
511 such a thing) so that we can properly perform the construction of
512 file-scope static-storage C++ objects within shared libraries. */
514 static void __attribute__((used))
515 __do_global_ctors_aux (void) /* prologue goes in .init section */
517 FORCE_CODE_SECTION_ALIGN /* explicit align before switch to .text */
518 asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */
519 DO_GLOBAL_CTORS_BODY;
520 atexit (__do_global_dtors);
523 #endif /* OBJECT_FORMAT_ELF */
525 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
527 extern void __do_global_dtors (void);
529 /* This case is used by the Irix 6 port, which supports named sections but
530 not an SVR4-style .fini section. __do_global_dtors can be non-static
531 in this case because we protect it with -hidden_symbol. */
533 void
534 __do_global_dtors (void)
536 func_ptr *p, f;
537 for (p = __DTOR_LIST__ + 1; (f = *p); p++)
538 f ();
540 #if USE_TM_CLONE_REGISTRY
541 deregister_tm_clones ();
542 #endif /* USE_TM_CLONE_REGISTRY */
544 #ifdef USE_EH_FRAME_REGISTRY
545 if (__deregister_frame_info)
546 __deregister_frame_info (__EH_FRAME_BEGIN__);
547 #endif
550 #if defined(USE_EH_FRAME_REGISTRY) \
551 || defined(USE_TM_CLONE_REGISTRY)
552 /* A helper function for __do_global_ctors, which is in crtend.o. Here
553 in crtbegin.o, we can reference a couple of symbols not visible there.
554 Plus, since we're before libgcc.a, we have no problems referencing
555 functions from there. */
556 void
557 __do_global_ctors_1(void)
559 #ifdef USE_EH_FRAME_REGISTRY
560 static struct object object;
561 if (__register_frame_info)
562 __register_frame_info (__EH_FRAME_BEGIN__, &object);
563 #endif
565 #if USE_TM_CLONE_REGISTRY
566 register_tm_clones ();
567 #endif /* USE_TM_CLONE_REGISTRY */
569 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
571 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
572 #error "What are you doing with crtstuff.c, then?"
573 #endif
575 #elif defined(CRT_END) /* ! CRT_BEGIN */
577 /* No need for .ctors/.dtors section if linker can place them in
578 .init_array/.fini_array section. */
579 #ifndef USE_INITFINI_ARRAY
580 /* Put a word containing zero at the end of each of our two lists of function
581 addresses. Note that the words defined here go into the .ctors and .dtors
582 sections of the crtend.o file, and since that file is always linked in
583 last, these words naturally end up at the very ends of the two lists
584 contained in these two sections. */
586 #ifdef CTOR_LIST_END
587 CTOR_LIST_END;
588 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
589 /* Hack: force cc1 to switch to .data section early, so that assembling
590 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */
591 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
592 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
593 STATIC func_ptr __CTOR_END__[1]
594 __attribute__((aligned(sizeof(func_ptr))))
595 = { (func_ptr) 0 };
596 #else
597 STATIC func_ptr __CTOR_END__[1]
598 __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
599 = { (func_ptr) 0 };
600 #endif
602 #ifdef DTOR_LIST_END
603 DTOR_LIST_END;
604 #elif defined(HIDDEN_DTOR_LIST_END)
605 #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
606 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
607 #endif
608 func_ptr __DTOR_END__[1]
609 __attribute__ ((used,
610 #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
611 section(".dtors"),
612 #endif
613 aligned(sizeof(func_ptr)), visibility ("hidden")))
614 = { (func_ptr) 0 };
615 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
616 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
617 STATIC func_ptr __DTOR_END__[1]
618 __attribute__ ((used, aligned(sizeof(func_ptr))))
619 = { (func_ptr) 0 };
620 #else
621 STATIC func_ptr __DTOR_END__[1]
622 __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
623 = { (func_ptr) 0 };
624 #endif
625 #endif /* USE_INITFINI_ARRAY */
627 #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
628 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
629 this would be the 'length' field in a real FDE. */
630 # if __INT_MAX__ == 2147483647
631 typedef int int32;
632 # elif __LONG_MAX__ == 2147483647
633 typedef long int32;
634 # elif __SHRT_MAX__ == 2147483647
635 typedef short int32;
636 # else
637 # error "Missing a 4 byte integer"
638 # endif
639 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
640 __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
641 aligned(sizeof(int32))))
642 = { 0 };
643 #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
645 #if USE_TM_CLONE_REGISTRY
646 # ifndef HAVE_GAS_HIDDEN
647 static
648 # endif
649 func_ptr __TMC_END__[]
650 __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
651 # ifdef HAVE_GAS_HIDDEN
652 __attribute__((__visibility__ ("hidden"))) = { };
653 # else
654 = { 0, 0 };
655 # endif
656 #endif /* USE_TM_CLONE_REGISTRY */
658 #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
660 /* If we are using .init_array, there is nothing to do. */
662 #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
664 #ifdef OBJECT_FORMAT_ELF
665 static void __attribute__((used))
666 __do_global_ctors_aux (void)
668 func_ptr *p;
669 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
670 (*p) ();
673 /* Stick a call to __do_global_ctors_aux into the .init section. */
674 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
675 #else /* OBJECT_FORMAT_ELF */
677 /* Stick the real initialization code, followed by a normal sort of
678 function epilogue at the very end of the .init section for this
679 entire root executable file or for this entire shared library file.
681 Note that we use some tricks here to get *just* the body and just
682 a function epilogue (but no function prologue) into the .init
683 section of the crtend.o file. Specifically, we switch to the .text
684 section, start to define a function, and then we switch to the .init
685 section just before the body code.
687 Earlier on, we put the corresponding function prologue into the .init
688 section of the crtbegin.o file (which will be linked in first).
690 Note that we want to invoke all constructors for C++ file-scope static-
691 storage objects AFTER any other possible initialization actions which
692 may be performed by the code in the .init section contributions made by
693 other libraries, etc. That's because those other initializations may
694 include setup operations for very primitive things (e.g. initializing
695 the state of the floating-point coprocessor, etc.) which should be done
696 before we start to execute any of the user's code. */
698 static void
699 __do_global_ctors_aux (void) /* prologue goes in .text section */
701 asm (__LIBGCC_INIT_SECTION_ASM_OP__);
702 DO_GLOBAL_CTORS_BODY;
703 atexit (__do_global_dtors);
704 } /* epilogue and body go in .init section */
706 FORCE_CODE_SECTION_ALIGN
707 asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
709 #endif /* OBJECT_FORMAT_ELF */
711 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
713 extern void __do_global_ctors (void);
715 /* This case is used by the Irix 6 port, which supports named sections but
716 not an SVR4-style .init section. __do_global_ctors can be non-static
717 in this case because we protect it with -hidden_symbol. */
718 void
719 __do_global_ctors (void)
721 func_ptr *p;
722 #if defined(USE_EH_FRAME_REGISTRY) \
723 || defined(USE_TM_CLONE_REGISTRY)
724 __do_global_ctors_1();
725 #endif
726 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
727 (*p) ();
730 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
731 #error "What are you doing with crtstuff.c, then?"
732 #endif
734 #else /* ! CRT_BEGIN && ! CRT_END */
735 #error "One of CRT_BEGIN or CRT_END must be defined."
736 #endif