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). 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 #endif 157 158 /* 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. 161 162 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. 167 168 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. 172 173 So, we take an approach similar to #pragma weak -- we have a second 174 declaration for functions that we want to have weak references. 175 176 Neither way is particularly good. */ 177 178 /* 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); 190 191 /* Likewise for _Jv_RegisterClasses. */ 192 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK; 193 194 /* 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; 197 198 #ifdef OBJECT_FORMAT_ELF 199 200 /* Declare a pointer to void function type. */ 201 typedef void (*func_ptr) (void); 202 #define STATIC static 203 204 #else /* OBJECT_FORMAT_ELF */ 205 206 #include "gbl-ctors.h" 207 208 #define STATIC 209 210 #endif /* OBJECT_FORMAT_ELF */ 211 212 #ifdef CRT_BEGIN 213 214 /* 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. */ 225 226 /* 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 */ 246 247 #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 */ 260 261 #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 */ 268 269 #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 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 /* 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. */ 334 335 #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 346 347 /* 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; 350 351 /* Run all the global destructors on exit from the program. */ 352 353 /* 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. 358 359 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. 364 365 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. */ 369 370 static void __attribute__((used)) 371 __do_global_dtors_aux (void) 372 { 373 static _Bool completed; 374 375 if (__builtin_expect (completed, 0)) 376 return; 377 378 #ifdef CRTSTUFFS_O 379 if (__cxa_finalize) 380 __cxa_finalize (__dso_handle); 381 #endif 382 383 #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) 387 { 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; 394 395 __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__)); 396 while (dtor_idx < max_idx) 397 dtor_list[++dtor_idx] (); 398 } 399 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */ 400 { 401 static func_ptr *p = __DTOR_LIST__ + 1; 402 func_ptr f; 403 404 while ((f = *p)) 405 { 406 p++; 407 f (); 408 } 409 } 410 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */ 411 412 #if USE_TM_CLONE_REGISTRY 413 deregister_tm_clones (); 414 #endif /* USE_TM_CLONE_REGISTRY */ 415 416 #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 427 428 completed = 1; 429 } 430 431 /* 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) 441 { 442 atexit (__do_global_dtors_aux); 443 } 444 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, 445 __do_global_dtors_aux_1) 446 #endif 447 448 #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. */ 453 454 static void __attribute__((used)) 455 frame_dummy (void) 456 { 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 */ 470 471 #if USE_TM_CLONE_REGISTRY 472 register_tm_clones (); 473 #endif /* USE_TM_CLONE_REGISTRY */ 474 } 475 476 #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 */ 484 485 #else /* OBJECT_FORMAT_ELF */ 486 487 /* 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. */ 493 494 static void __do_global_ctors_aux (void); 495 void 496 __do_global_ctors (void) 497 { 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 505 } 506 507 asm (__LIBGCC_INIT_SECTION_ASM_OP__); /* cc1 doesn't know that we are switching! */ 508 509 /* 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. */ 513 514 static void __attribute__((used)) 515 __do_global_ctors_aux (void) /* prologue goes in .init section */ 516 { 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); 521 } 522 523 #endif /* OBJECT_FORMAT_ELF */ 524 525 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ 526 527 extern void __do_global_dtors (void); 528 529 /* 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. */ 532 533 void 534 __do_global_dtors (void) 535 { 536 func_ptr *p, f; 537 for (p = __DTOR_LIST__ + 1; (f = *p); p++) 538 f (); 539 540 #if USE_TM_CLONE_REGISTRY 541 deregister_tm_clones (); 542 #endif /* USE_TM_CLONE_REGISTRY */ 543 544 #ifdef USE_EH_FRAME_REGISTRY 545 if (__deregister_frame_info) 546 __deregister_frame_info (__EH_FRAME_BEGIN__); 547 #endif 548 } 549 550 #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) 558 { 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 564 565 #if USE_TM_CLONE_REGISTRY 566 register_tm_clones (); 567 #endif /* USE_TM_CLONE_REGISTRY */ 568 } 569 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */ 570 571 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ 572 #error "What are you doing with crtstuff.c, then?" 573 #endif 574 575 #elif defined(CRT_END) /* ! CRT_BEGIN */ 576 577 /* 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. */ 585 586 #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 601 602 #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 */ 626 627 #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__ */ 644 645 #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 */ 657 658 #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__ 659 660 /* If we are using .init_array, there is nothing to do. */ 661 662 #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__) 663 664 #ifdef OBJECT_FORMAT_ELF 665 static void __attribute__((used)) 666 __do_global_ctors_aux (void) 667 { 668 func_ptr *p; 669 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) 670 (*p) (); 671 } 672 673 /* 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 */ 676 677 /* 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. 680 681 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. 686 687 Earlier on, we put the corresponding function prologue into the .init 688 section of the crtbegin.o file (which will be linked in first). 689 690 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. */ 697 698 static void 699 __do_global_ctors_aux (void) /* prologue goes in .text section */ 700 { 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 */ 705 706 FORCE_CODE_SECTION_ALIGN 707 asm (__LIBGCC_TEXT_SECTION_ASM_OP__); 708 709 #endif /* OBJECT_FORMAT_ELF */ 710 711 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ 712 713 extern void __do_global_ctors (void); 714 715 /* 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) 720 { 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) (); 728 } 729 730 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ 731 #error "What are you doing with crtstuff.c, then?" 732 #endif 733 734 #else /* ! CRT_BEGIN && ! CRT_END */ 735 #error "One of CRT_BEGIN or CRT_END must be defined." 736 #endif 737