1/* Specialized bits of code needed to support construction and 2 destruction of file-scope objects in C++ code. 3 Copyright (C) 1991-2015 Free Software Foundation, Inc. 4 Contributed by Ron Guilmette (rfg@monkeys.com). 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18Under Section 7 of GPL version 3, you are granted additional 19permissions described in the GCC Runtime Library Exception, version 203.1, as published by the Free Software Foundation. 21 22You should have received a copy of the GNU General Public License and 23a copy of the GCC Runtime Library Exception along with this program; 24see 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) \ 73static void __attribute__((__used__)) \ 74call_ ## 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__)) 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#ifndef __HAIKU__ 112#include <link.h> 113#endif 114/* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h. 115 But it doesn't use PT_GNU_EH_FRAME ELF segment currently. */ 116# if !defined(__UCLIBC__) \ 117 && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \ 118 || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG))) 119# define USE_PT_GNU_EH_FRAME 120# endif 121#endif 122 123#if defined(OBJECT_FORMAT_ELF) \ 124 && !defined(OBJECT_FORMAT_FLAT) \ 125 && defined(HAVE_LD_EH_FRAME_HDR) \ 126 && !defined(CRTSTUFFT_O) \ 127 && defined(inhibit_libc) \ 128 && (defined(__GLIBC__) || defined(__gnu_linux__) || defined(__GNU__)) 129/* On systems using glibc, an inhibit_libc build of libgcc is only 130 part of a bootstrap process. Build the same crt*.o as would be 131 built with headers present, so that it is not necessary to build 132 glibc more than once for the bootstrap to converge. */ 133# define USE_PT_GNU_EH_FRAME 134#endif 135 136#ifdef USE_EH_FRAME_REGISTRY_ALWAYS 137# ifndef __LIBGCC_EH_FRAME_SECTION_NAME__ 138# error "Can't use explicit exception-frame-registration without __LIBGCC_EH_FRAME_SECTION_NAME__" 139# endif 140#endif 141#if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) && (!defined(USE_PT_GNU_EH_FRAME) || defined(USE_EH_FRAME_REGISTRY_ALWAYS)) 142# define USE_EH_FRAME_REGISTRY 143#endif 144#if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) \ 145 && __LIBGCC_EH_TABLES_CAN_BE_READ_ONLY__ 146# define EH_FRAME_SECTION_CONST const 147#else 148# define EH_FRAME_SECTION_CONST 149#endif 150 151#if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \ 152 && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP) 153# define HIDDEN_DTOR_LIST_END 154#endif 155 156#if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF) 157# define USE_TM_CLONE_REGISTRY 1 158#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. */ 182extern void __register_frame_info (const void *, struct object *) 183 TARGET_ATTRIBUTE_WEAK; 184extern void __register_frame_info_bases (const void *, struct object *, 185 void *, void *) 186 TARGET_ATTRIBUTE_WEAK; 187extern void *__deregister_frame_info (const void *) 188 TARGET_ATTRIBUTE_WEAK; 189extern void *__deregister_frame_info_bases (const void *) 190 TARGET_ATTRIBUTE_WEAK; 191extern void __do_global_ctors_1 (void); 192 193/* Likewise for _Jv_RegisterClasses. */ 194extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK; 195 196/* Likewise for transactional memory clone tables. */ 197extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK; 198extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK; 199 200#ifdef OBJECT_FORMAT_ELF 201 202/* Declare a pointer to void function type. */ 203typedef void (*func_ptr) (void); 204#define STATIC static 205 206#else /* OBJECT_FORMAT_ELF */ 207 208#include "gbl-ctors.h" 209 210#define STATIC 211 212#endif /* OBJECT_FORMAT_ELF */ 213 214#ifdef CRT_BEGIN 215 216/* NOTE: In order to be able to support SVR4 shared libraries, we arrange 217 to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__, 218 __DTOR_END__ } per root executable and also one set of these symbols 219 per shared library. So in any given whole process image, we may have 220 multiple definitions of each of these symbols. In order to prevent 221 these definitions from conflicting with one another, and in order to 222 ensure that the proper lists are used for the initialization/finalization 223 of each individual shared library (respectively), we give these symbols 224 only internal (i.e. `static') linkage, and we also make it a point to 225 refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__ 226 symbol in crtbegin.o, where they are defined. */ 227 228/* No need for .ctors/.dtors section if linker can place them in 229 .init_array/.fini_array section. */ 230#ifndef USE_INITFINI_ARRAY 231/* The -1 is a flag to __do_global_[cd]tors indicating that this table 232 does not start with a count of elements. */ 233#ifdef CTOR_LIST_BEGIN 234CTOR_LIST_BEGIN; 235#elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__) 236/* Hack: force cc1 to switch to .data section early, so that assembling 237 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */ 238static func_ptr force_to_data[1] __attribute__ ((__used__)) = { }; 239asm (__LIBGCC_CTORS_SECTION_ASM_OP__); 240STATIC func_ptr __CTOR_LIST__[1] 241 __attribute__ ((__used__, aligned(sizeof(func_ptr)))) 242 = { (func_ptr) (-1) }; 243#else 244STATIC func_ptr __CTOR_LIST__[1] 245 __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr)))) 246 = { (func_ptr) (-1) }; 247#endif /* __CTOR_LIST__ alternatives */ 248 249#ifdef DTOR_LIST_BEGIN 250DTOR_LIST_BEGIN; 251#elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__) 252asm (__LIBGCC_DTORS_SECTION_ASM_OP__); 253STATIC func_ptr __DTOR_LIST__[1] 254 __attribute__ ((aligned(sizeof(func_ptr)))) 255 = { (func_ptr) (-1) }; 256#else 257STATIC func_ptr __DTOR_LIST__[1] 258 __attribute__((section(".dtors"), aligned(sizeof(func_ptr)))) 259 = { (func_ptr) (-1) }; 260#endif /* __DTOR_LIST__ alternatives */ 261#endif /* USE_INITFINI_ARRAY */ 262 263#ifdef USE_EH_FRAME_REGISTRY 264/* Stick a label at the beginning of the frame unwind info so we can register 265 and deregister it with the exception handling library code. */ 266STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[] 267 __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4))) 268 = { }; 269#endif /* USE_EH_FRAME_REGISTRY */ 270 271#ifdef __LIBGCC_JCR_SECTION_NAME__ 272/* Stick a label at the beginning of the java class registration info 273 so we can register them properly. */ 274STATIC void *__JCR_LIST__[] 275 __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__), 276 aligned(sizeof(void*)))) 277 = { }; 278#endif /* __LIBGCC_JCR_SECTION_NAME__ */ 279 280#if USE_TM_CLONE_REGISTRY 281STATIC func_ptr __TMC_LIST__[] 282 __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*)))) 283 = { }; 284# ifdef HAVE_GAS_HIDDEN 285extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden"))); 286# endif 287 288static inline void 289deregister_tm_clones (void) 290{ 291 void (*fn) (void *); 292 293#ifdef HAVE_GAS_HIDDEN 294 if (__TMC_END__ - __TMC_LIST__ == 0) 295 return; 296#else 297 if (__TMC_LIST__[0] == NULL) 298 return; 299#endif 300 301 fn = _ITM_deregisterTMCloneTable; 302 __asm ("" : "+r" (fn)); 303 if (fn) 304 fn (__TMC_LIST__); 305} 306 307static inline void 308register_tm_clones (void) 309{ 310 void (*fn) (void *, size_t); 311 size_t size; 312 313#ifdef HAVE_GAS_HIDDEN 314 size = (__TMC_END__ - __TMC_LIST__) / 2; 315#else 316 for (size = 0; __TMC_LIST__[size * 2] != NULL; size++) 317 continue; 318#endif 319 if (size == 0) 320 return; 321 322 fn = _ITM_registerTMCloneTable; 323 __asm ("" : "+r" (fn)); 324 if (fn) 325 fn (__TMC_LIST__, size); 326} 327#endif /* USE_TM_CLONE_REGISTRY */ 328 329#if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \ 330 || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__) 331 332#ifdef OBJECT_FORMAT_ELF 333 334/* Declare the __dso_handle variable. It should have a unique value 335 in every shared-object; in a main program its value is zero. The 336 object should in any case be protected. This means the instance 337 in one DSO or the main program is not used in another object. The 338 dynamic linker takes care of this. */ 339 340#ifdef TARGET_LIBGCC_SDATA_SECTION 341extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION))); 342#endif 343#ifdef HAVE_GAS_HIDDEN 344extern void *__dso_handle __attribute__ ((__visibility__ ("hidden"))); 345#endif 346#ifdef CRTSTUFFS_O 347void *__dso_handle = &__dso_handle; 348#else 349void *__dso_handle = 0; 350#endif 351 352/* The __cxa_finalize function may not be available so we use only a 353 weak declaration. */ 354extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK; 355 356/* Run all the global destructors on exit from the program. */ 357 358/* Some systems place the number of pointers in the first word of the 359 table. On SVR4 however, that word is -1. In all cases, the table is 360 null-terminated. On SVR4, we start from the beginning of the list and 361 invoke each per-compilation-unit destructor routine in order 362 until we find that null. 363 364 Note that this function MUST be static. There will be one of these 365 functions in each root executable and one in each shared library, but 366 although they all have the same code, each one is unique in that it 367 refers to one particular associated `__DTOR_LIST__' which belongs to the 368 same particular root executable or shared library file. 369 370 On some systems, this routine is run more than once from the .fini, 371 when exit is called recursively, so we arrange to remember where in 372 the list we left off processing, and we resume at that point, 373 should we be re-invoked. */ 374 375static void __attribute__((used)) 376__do_global_dtors_aux (void) 377{ 378 static _Bool completed; 379 380 if (__builtin_expect (completed, 0)) 381 return; 382 383#ifdef CRTSTUFFS_O 384 if (__cxa_finalize) 385 __cxa_finalize (__dso_handle); 386#endif 387 388#ifdef FINI_ARRAY_SECTION_ASM_OP 389 /* If we are using .fini_array then destructors will be run via that 390 mechanism. */ 391#elif defined(HIDDEN_DTOR_LIST_END) 392 { 393 /* Safer version that makes sure only .dtors function pointers are 394 called even if the static variable is maliciously changed. */ 395 extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden"))); 396 static size_t dtor_idx; 397 const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1; 398 func_ptr *dtor_list; 399 400 __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__)); 401 while (dtor_idx < max_idx) 402 dtor_list[++dtor_idx] (); 403 } 404#else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */ 405 { 406 static func_ptr *p = __DTOR_LIST__ + 1; 407 func_ptr f; 408 409 while ((f = *p)) 410 { 411 p++; 412 f (); 413 } 414 } 415#endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */ 416 417#if USE_TM_CLONE_REGISTRY 418 deregister_tm_clones (); 419#endif /* USE_TM_CLONE_REGISTRY */ 420 421#ifdef USE_EH_FRAME_REGISTRY 422#ifdef CRT_GET_RFIB_DATA 423 /* If we used the new __register_frame_info_bases interface, 424 make sure that we deregister from the same place. */ 425 if (__deregister_frame_info_bases) 426 __deregister_frame_info_bases (__EH_FRAME_BEGIN__); 427#else 428 if (__deregister_frame_info) 429 __deregister_frame_info (__EH_FRAME_BEGIN__); 430#endif 431#endif 432 433 completed = 1; 434} 435 436/* Stick a call to __do_global_dtors_aux into the .fini section. */ 437#ifdef FINI_SECTION_ASM_OP 438CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux) 439#elif defined (FINI_ARRAY_SECTION_ASM_OP) 440static func_ptr __do_global_dtors_aux_fini_array_entry[] 441 __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr)))) 442 = { __do_global_dtors_aux }; 443#else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */ 444static void __attribute__((used)) 445__do_global_dtors_aux_1 (void) 446{ 447 atexit (__do_global_dtors_aux); 448} 449CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, 450 __do_global_dtors_aux_1) 451#endif 452 453#if defined(USE_EH_FRAME_REGISTRY) \ 454 || defined(__LIBGCC_JCR_SECTION_NAME__) \ 455 || defined(USE_TM_CLONE_REGISTRY) 456/* Stick a call to __register_frame_info into the .init section. For some 457 reason calls with no arguments work more reliably in .init, so stick the 458 call in another function. */ 459 460static void __attribute__((used)) 461frame_dummy (void) 462{ 463#ifdef USE_EH_FRAME_REGISTRY 464 static struct object object; 465#ifdef CRT_GET_RFIB_DATA 466 void *tbase, *dbase; 467 tbase = 0; 468 CRT_GET_RFIB_DATA (dbase); 469 if (__register_frame_info_bases) 470 __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase); 471#else 472 if (__register_frame_info) 473 __register_frame_info (__EH_FRAME_BEGIN__, &object); 474#endif /* CRT_GET_RFIB_DATA */ 475#endif /* USE_EH_FRAME_REGISTRY */ 476 477#ifdef __LIBGCC_JCR_SECTION_NAME__ 478 void **jcr_list; 479 __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__)); 480 if (__builtin_expect (*jcr_list != NULL, 0)) 481 { 482 void (*register_classes) (void *) = _Jv_RegisterClasses; 483 __asm ("" : "+r" (register_classes)); 484 if (register_classes) 485 register_classes (jcr_list); 486 } 487#endif /* __LIBGCC_JCR_SECTION_NAME__ */ 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__ 495CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy) 496#else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */ 497static func_ptr __frame_dummy_init_array_entry[] 498 __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr)))) 499 = { frame_dummy }; 500#endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */ 501#endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */ 502 503#else /* OBJECT_FORMAT_ELF */ 504 505/* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o 506 and once in crtend.o). It must be declared static to avoid a link 507 error. Here, we define __do_global_ctors as an externally callable 508 function. It is externally callable so that __main can invoke it when 509 INVOKE__main is defined. This has the additional effect of forcing cc1 510 to switch to the .text section. */ 511 512static void __do_global_ctors_aux (void); 513void 514__do_global_ctors (void) 515{ 516#ifdef INVOKE__main 517 /* If __main won't actually call __do_global_ctors then it doesn't matter 518 what's inside the function. The inside of __do_global_ctors_aux is 519 called automatically in that case. And the Alliant fx2800 linker 520 crashes on this reference. So prevent the crash. */ 521 __do_global_ctors_aux (); 522#endif 523} 524 525asm (__LIBGCC_INIT_SECTION_ASM_OP__); /* cc1 doesn't know that we are switching! */ 526 527/* A routine to invoke all of the global constructors upon entry to the 528 program. We put this into the .init section (for systems that have 529 such a thing) so that we can properly perform the construction of 530 file-scope static-storage C++ objects within shared libraries. */ 531 532static void __attribute__((used)) 533__do_global_ctors_aux (void) /* prologue goes in .init section */ 534{ 535 FORCE_CODE_SECTION_ALIGN /* explicit align before switch to .text */ 536 asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */ 537 DO_GLOBAL_CTORS_BODY; 538 atexit (__do_global_dtors); 539} 540 541#endif /* OBJECT_FORMAT_ELF */ 542 543#elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ 544 545extern void __do_global_dtors (void); 546 547/* This case is used by the Irix 6 port, which supports named sections but 548 not an SVR4-style .fini section. __do_global_dtors can be non-static 549 in this case because we protect it with -hidden_symbol. */ 550 551void 552__do_global_dtors (void) 553{ 554 func_ptr *p, f; 555 for (p = __DTOR_LIST__ + 1; (f = *p); p++) 556 f (); 557 558#if USE_TM_CLONE_REGISTRY 559 deregister_tm_clones (); 560#endif /* USE_TM_CLONE_REGISTRY */ 561 562#ifdef USE_EH_FRAME_REGISTRY 563 if (__deregister_frame_info) 564 __deregister_frame_info (__EH_FRAME_BEGIN__); 565#endif 566} 567 568#if defined(USE_EH_FRAME_REGISTRY) \ 569 || defined(__LIBGCC_JCR_SECTION_NAME__) \ 570 || defined(USE_TM_CLONE_REGISTRY) 571/* A helper function for __do_global_ctors, which is in crtend.o. Here 572 in crtbegin.o, we can reference a couple of symbols not visible there. 573 Plus, since we're before libgcc.a, we have no problems referencing 574 functions from there. */ 575void 576__do_global_ctors_1(void) 577{ 578#ifdef USE_EH_FRAME_REGISTRY 579 static struct object object; 580 if (__register_frame_info) 581 __register_frame_info (__EH_FRAME_BEGIN__, &object); 582#endif 583 584#ifdef __LIBGCC_JCR_SECTION_NAME__ 585 void **jcr_list; 586 __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__)); 587 if (__builtin_expect (*jcr_list != NULL, 0)) 588 { 589 void (*register_classes) (void *) = _Jv_RegisterClasses; 590 __asm ("" : "+r" (register_classes)); 591 if (register_classes) 592 register_classes (jcr_list); 593 } 594#endif 595 596#if USE_TM_CLONE_REGISTRY 597 register_tm_clones (); 598#endif /* USE_TM_CLONE_REGISTRY */ 599} 600#endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */ 601 602#else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ 603#error "What are you doing with crtstuff.c, then?" 604#endif 605 606#elif defined(CRT_END) /* ! CRT_BEGIN */ 607 608/* No need for .ctors/.dtors section if linker can place them in 609 .init_array/.fini_array section. */ 610#ifndef USE_INITFINI_ARRAY 611/* Put a word containing zero at the end of each of our two lists of function 612 addresses. Note that the words defined here go into the .ctors and .dtors 613 sections of the crtend.o file, and since that file is always linked in 614 last, these words naturally end up at the very ends of the two lists 615 contained in these two sections. */ 616 617#ifdef CTOR_LIST_END 618CTOR_LIST_END; 619#elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__) 620/* Hack: force cc1 to switch to .data section early, so that assembling 621 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */ 622static func_ptr force_to_data[1] __attribute__ ((__used__)) = { }; 623asm (__LIBGCC_CTORS_SECTION_ASM_OP__); 624STATIC func_ptr __CTOR_END__[1] 625 __attribute__((aligned(sizeof(func_ptr)))) 626 = { (func_ptr) 0 }; 627#else 628STATIC func_ptr __CTOR_END__[1] 629 __attribute__((section(".ctors"), aligned(sizeof(func_ptr)))) 630 = { (func_ptr) 0 }; 631#endif 632 633#ifdef DTOR_LIST_END 634DTOR_LIST_END; 635#elif defined(HIDDEN_DTOR_LIST_END) 636#ifdef __LIBGCC_DTORS_SECTION_ASM_OP__ 637asm (__LIBGCC_DTORS_SECTION_ASM_OP__); 638#endif 639func_ptr __DTOR_END__[1] 640 __attribute__ ((used, 641#ifndef __LIBGCC_DTORS_SECTION_ASM_OP__ 642 section(".dtors"), 643#endif 644 aligned(sizeof(func_ptr)), visibility ("hidden"))) 645 = { (func_ptr) 0 }; 646#elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__) 647asm (__LIBGCC_DTORS_SECTION_ASM_OP__); 648STATIC func_ptr __DTOR_END__[1] 649 __attribute__ ((used, aligned(sizeof(func_ptr)))) 650 = { (func_ptr) 0 }; 651#else 652STATIC func_ptr __DTOR_END__[1] 653 __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr)))) 654 = { (func_ptr) 0 }; 655#endif 656#endif /* USE_INITFINI_ARRAY */ 657 658#ifdef __LIBGCC_EH_FRAME_SECTION_NAME__ 659/* Terminate the frame unwind info section with a 4byte 0 as a sentinel; 660 this would be the 'length' field in a real FDE. */ 661# if __INT_MAX__ == 2147483647 662typedef int int32; 663# elif __LONG_MAX__ == 2147483647 664typedef long int32; 665# elif __SHRT_MAX__ == 2147483647 666typedef short int32; 667# else 668# error "Missing a 4 byte integer" 669# endif 670STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[] 671 __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__), 672 aligned(sizeof(int32)))) 673 = { 0 }; 674#endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */ 675 676#ifdef __LIBGCC_JCR_SECTION_NAME__ 677/* Null terminate the .jcr section array. */ 678STATIC void *__JCR_END__[1] 679 __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__), 680 aligned(sizeof(void *)))) 681 = { 0 }; 682#endif /* __LIBGCC_JCR_SECTION_NAME__ */ 683 684#if USE_TM_CLONE_REGISTRY 685# ifndef HAVE_GAS_HIDDEN 686static 687# endif 688func_ptr __TMC_END__[] 689 __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *)))) 690# ifdef HAVE_GAS_HIDDEN 691 __attribute__((__visibility__ ("hidden"))) = { }; 692# else 693 = { 0, 0 }; 694# endif 695#endif /* USE_TM_CLONE_REGISTRY */ 696 697#ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__ 698 699/* If we are using .init_array, there is nothing to do. */ 700 701#elif defined(__LIBGCC_INIT_SECTION_ASM_OP__) 702 703#ifdef OBJECT_FORMAT_ELF 704static void __attribute__((used)) 705__do_global_ctors_aux (void) 706{ 707 func_ptr *p; 708 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) 709 (*p) (); 710} 711 712/* Stick a call to __do_global_ctors_aux into the .init section. */ 713CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux) 714#else /* OBJECT_FORMAT_ELF */ 715 716/* Stick the real initialization code, followed by a normal sort of 717 function epilogue at the very end of the .init section for this 718 entire root executable file or for this entire shared library file. 719 720 Note that we use some tricks here to get *just* the body and just 721 a function epilogue (but no function prologue) into the .init 722 section of the crtend.o file. Specifically, we switch to the .text 723 section, start to define a function, and then we switch to the .init 724 section just before the body code. 725 726 Earlier on, we put the corresponding function prologue into the .init 727 section of the crtbegin.o file (which will be linked in first). 728 729 Note that we want to invoke all constructors for C++ file-scope static- 730 storage objects AFTER any other possible initialization actions which 731 may be performed by the code in the .init section contributions made by 732 other libraries, etc. That's because those other initializations may 733 include setup operations for very primitive things (e.g. initializing 734 the state of the floating-point coprocessor, etc.) which should be done 735 before we start to execute any of the user's code. */ 736 737static void 738__do_global_ctors_aux (void) /* prologue goes in .text section */ 739{ 740 asm (__LIBGCC_INIT_SECTION_ASM_OP__); 741 DO_GLOBAL_CTORS_BODY; 742 atexit (__do_global_dtors); 743} /* epilogue and body go in .init section */ 744 745FORCE_CODE_SECTION_ALIGN 746asm (__LIBGCC_TEXT_SECTION_ASM_OP__); 747 748#endif /* OBJECT_FORMAT_ELF */ 749 750#elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */ 751 752extern void __do_global_ctors (void); 753 754/* This case is used by the Irix 6 port, which supports named sections but 755 not an SVR4-style .init section. __do_global_ctors can be non-static 756 in this case because we protect it with -hidden_symbol. */ 757void 758__do_global_ctors (void) 759{ 760 func_ptr *p; 761#if defined(USE_EH_FRAME_REGISTRY) \ 762 || defined(__LIBGCC_JCR_SECTION_NAME__) \ 763 || defined(USE_TM_CLONE_REGISTRY) 764 __do_global_ctors_1(); 765#endif 766 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) 767 (*p) (); 768} 769 770#else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */ 771#error "What are you doing with crtstuff.c, then?" 772#endif 773 774#else /* ! CRT_BEGIN && ! CRT_END */ 775#error "One of CRT_BEGIN or CRT_END must be defined." 776#endif 777