libgcc/crtstuff.c

   1 /* Specialized bits of code needed to support construction and
   2    destruction of file-scope objects in C++ code.
   3    Copyright (C) 1991-2016 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__))
  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   if (__TMC_END__ - __TMC_LIST__ == 0)
 284     return;
 285 #else
 286   if (__TMC_LIST__[0] == NULL)
 287     return;
 288 #endif
 289
 290   fn = _ITM_deregisterTMCloneTable;
 291   __asm ("" : "+r" (fn));
 292   if (fn)
 293     fn (__TMC_LIST__);
 294 }
 295
 296 static inline void
 297 register_tm_clones (void)
 298 {
 299   void (*fn) (void *, size_t);
 300   size_t size;
 301
 302 #ifdef HAVE_GAS_HIDDEN
 303   size = (__TMC_END__ - __TMC_LIST__) / 2;
 304 #else
 305   for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
 306     continue;
 307 #endif
 308   if (size == 0)
 309     return;
 310
 311   fn = _ITM_registerTMCloneTable;
 312   __asm ("" : "+r" (fn));
 313   if (fn)
 314     fn (__TMC_LIST__, size);
 315 }
 316 #endif /* USE_TM_CLONE_REGISTRY */
 317
 318 #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
 319     || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
 320
 321 #ifdef OBJECT_FORMAT_ELF
 322
 323 /* Declare the __dso_handle variable.  It should have a unique value
 324    in every shared-object; in a main program its value is zero.  The
 325    object should in any case be protected.  This means the instance
 326    in one DSO or the main program is not used in another object.  The
 327    dynamic linker takes care of this.  */
 328
 329 #ifdef TARGET_LIBGCC_SDATA_SECTION
 330 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
 331 #endif
 332 #ifdef HAVE_GAS_HIDDEN
 333 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 334 #endif
 335 #ifdef CRTSTUFFS_O
 336 void *__dso_handle = &__dso_handle;
 337 #else
 338 void *__dso_handle = 0;
 339 #endif
 340
 341 /* The __cxa_finalize function may not be available so we use only a
 342    weak declaration.  */
 343 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
 344
 345 /* Run all the global destructors on exit from the program.  */
 346
 347 /* Some systems place the number of pointers in the first word of the
 348    table.  On SVR4 however, that word is -1.  In all cases, the table is
 349    null-terminated.  On SVR4, we start from the beginning of the list and
 350    invoke each per-compilation-unit destructor routine in order
 351    until we find that null.
 352
 353    Note that this function MUST be static.  There will be one of these
 354    functions in each root executable and one in each shared library, but
 355    although they all have the same code, each one is unique in that it
 356    refers to one particular associated `__DTOR_LIST__' which belongs to the
 357    same particular root executable or shared library file.
 358
 359    On some systems, this routine is run more than once from the .fini,
 360    when exit is called recursively, so we arrange to remember where in
 361    the list we left off processing, and we resume at that point,
 362    should we be re-invoked.  */
 363
 364 static void __attribute__((used))
 365 __do_global_dtors_aux (void)
 366 {
 367   static _Bool completed;
 368
 369   if (__builtin_expect (completed, 0))
 370     return;
 371
 372 #ifdef CRTSTUFFS_O
 373   if (__cxa_finalize)
 374     __cxa_finalize (__dso_handle);
 375 #endif
 376
 377 #ifdef FINI_ARRAY_SECTION_ASM_OP
 378   /* If we are using .fini_array then destructors will be run via that
 379      mechanism.  */
 380 #elif defined(HIDDEN_DTOR_LIST_END)
 381   {
 382     /* Safer version that makes sure only .dtors function pointers are
 383        called even if the static variable is maliciously changed.  */
 384     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
 385     static size_t dtor_idx;
 386     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
 387     func_ptr *dtor_list;
 388
 389     __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__));
 390     while (dtor_idx < max_idx)
 391       dtor_list[++dtor_idx] ();
 392   }
 393 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
 394   {
 395     static func_ptr *p = __DTOR_LIST__ + 1;
 396     func_ptr f;
 397
 398     while ((f = *p))
 399       {
 400         p++;
 401         f ();
 402       }
 403   }
 404 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
 405
 406 #if USE_TM_CLONE_REGISTRY
 407   deregister_tm_clones ();
 408 #endif /* USE_TM_CLONE_REGISTRY */
 409
 410 #ifdef USE_EH_FRAME_REGISTRY
 411 #ifdef CRT_GET_RFIB_DATA
 412   /* If we used the new __register_frame_info_bases interface,
 413      make sure that we deregister from the same place.  */
 414   if (__deregister_frame_info_bases)
 415     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
 416 #else
 417   if (__deregister_frame_info)
 418     __deregister_frame_info (__EH_FRAME_BEGIN__);
 419 #endif
 420 #endif
 421
 422   completed = 1;
 423 }
 424
 425 /* Stick a call to __do_global_dtors_aux into the .fini section.  */
 426 #ifdef FINI_SECTION_ASM_OP
 427 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
 428 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
 429 static func_ptr __do_global_dtors_aux_fini_array_entry[]
 430   __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
 431   = { __do_global_dtors_aux };
 432 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
 433 static void __attribute__((used))
 434 __do_global_dtors_aux_1 (void)
 435 {
 436   atexit (__do_global_dtors_aux);
 437 }
 438 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
 439                           __do_global_dtors_aux_1)
 440 #endif
 441
 442 #if defined(USE_EH_FRAME_REGISTRY) \
 443     || defined(USE_TM_CLONE_REGISTRY)
 444 /* Stick a call to __register_frame_info into the .init section.  For some
 445    reason calls with no arguments work more reliably in .init, so stick the
 446    call in another function.  */
 447
 448 static void __attribute__((used))
 449 frame_dummy (void)
 450 {
 451 #ifdef USE_EH_FRAME_REGISTRY
 452   static struct object object;
 453 #ifdef CRT_GET_RFIB_DATA
 454   void *tbase, *dbase;
 455   tbase = 0;
 456   CRT_GET_RFIB_DATA (dbase);
 457   if (__register_frame_info_bases)
 458     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
 459 #else
 460   if (__register_frame_info)
 461     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 462 #endif /* CRT_GET_RFIB_DATA */
 463 #endif /* USE_EH_FRAME_REGISTRY */
 464
 465 #if USE_TM_CLONE_REGISTRY
 466   register_tm_clones ();
 467 #endif /* USE_TM_CLONE_REGISTRY */
 468 }
 469
 470 #ifdef __LIBGCC_INIT_SECTION_ASM_OP__
 471 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
 472 #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
 473 static func_ptr __frame_dummy_init_array_entry[]
 474   __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
 475   = { frame_dummy };
 476 #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
 477 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
 478
 479 #else  /* OBJECT_FORMAT_ELF */
 480
 481 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
 482    and once in crtend.o).  It must be declared static to avoid a link
 483    error.  Here, we define __do_global_ctors as an externally callable
 484    function.  It is externally callable so that __main can invoke it when
 485    INVOKE__main is defined.  This has the additional effect of forcing cc1
 486    to switch to the .text section.  */
 487
 488 static void __do_global_ctors_aux (void);
 489 void
 490 __do_global_ctors (void)
 491 {
 492 #ifdef INVOKE__main
 493   /* If __main won't actually call __do_global_ctors then it doesn't matter
 494      what's inside the function.  The inside of __do_global_ctors_aux is
 495      called automatically in that case.  And the Alliant fx2800 linker
 496      crashes on this reference.  So prevent the crash.  */
 497   __do_global_ctors_aux ();
 498 #endif
 499 }
 500
 501 asm (__LIBGCC_INIT_SECTION_ASM_OP__);   /* cc1 doesn't know that we are switching! */
 502
 503 /* A routine to invoke all of the global constructors upon entry to the
 504    program.  We put this into the .init section (for systems that have
 505    such a thing) so that we can properly perform the construction of
 506    file-scope static-storage C++ objects within shared libraries.  */
 507
 508 static void __attribute__((used))
 509 __do_global_ctors_aux (void)    /* prologue goes in .init section */
 510 {
 511   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
 512   asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */
 513   DO_GLOBAL_CTORS_BODY;
 514   atexit (__do_global_dtors);
 515 }
 516
 517 #endif /* OBJECT_FORMAT_ELF */
 518
 519 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
 520
 521 extern void __do_global_dtors (void);
 522
 523 /* This case is used by the Irix 6 port, which supports named sections but
 524    not an SVR4-style .fini section.  __do_global_dtors can be non-static
 525    in this case because we protect it with -hidden_symbol.  */
 526
 527 void
 528 __do_global_dtors (void)
 529 {
 530   func_ptr *p, f;
 531   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
 532     f ();
 533
 534 #if USE_TM_CLONE_REGISTRY
 535   deregister_tm_clones ();
 536 #endif /* USE_TM_CLONE_REGISTRY */
 537
 538 #ifdef USE_EH_FRAME_REGISTRY
 539   if (__deregister_frame_info)
 540     __deregister_frame_info (__EH_FRAME_BEGIN__);
 541 #endif
 542 }
 543
 544 #if defined(USE_EH_FRAME_REGISTRY) \
 545     || defined(USE_TM_CLONE_REGISTRY)
 546 /* A helper function for __do_global_ctors, which is in crtend.o.  Here
 547    in crtbegin.o, we can reference a couple of symbols not visible there.
 548    Plus, since we're before libgcc.a, we have no problems referencing
 549    functions from there.  */
 550 void
 551 __do_global_ctors_1(void)
 552 {
 553 #ifdef USE_EH_FRAME_REGISTRY
 554   static struct object object;
 555   if (__register_frame_info)
 556     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 557 #endif
 558
 559 #if USE_TM_CLONE_REGISTRY
 560   register_tm_clones ();
 561 #endif /* USE_TM_CLONE_REGISTRY */
 562 }
 563 #endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
 564
 565 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
 566 #error "What are you doing with crtstuff.c, then?"
 567 #endif
 568
 569 #elif defined(CRT_END) /* ! CRT_BEGIN */
 570
 571 /* No need for .ctors/.dtors section if linker can place them in
 572    .init_array/.fini_array section.  */
 573 #ifndef USE_INITFINI_ARRAY
 574 /* Put a word containing zero at the end of each of our two lists of function
 575    addresses.  Note that the words defined here go into the .ctors and .dtors
 576    sections of the crtend.o file, and since that file is always linked in
 577    last, these words naturally end up at the very ends of the two lists
 578    contained in these two sections.  */
 579
 580 #ifdef CTOR_LIST_END
 581 CTOR_LIST_END;
 582 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
 583 /* Hack: force cc1 to switch to .data section early, so that assembling
 584    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 585 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 586 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
 587 STATIC func_ptr __CTOR_END__[1]
 588   __attribute__((aligned(sizeof(func_ptr))))
 589   = { (func_ptr) 0 };
 590 #else
 591 STATIC func_ptr __CTOR_END__[1]
 592   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
 593   = { (func_ptr) 0 };
 594 #endif
 595
 596 #ifdef DTOR_LIST_END
 597 DTOR_LIST_END;
 598 #elif defined(HIDDEN_DTOR_LIST_END)
 599 #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
 600 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
 601 #endif
 602 func_ptr __DTOR_END__[1]
 603   __attribute__ ((used,
 604 #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
 605                   section(".dtors"),
 606 #endif
 607                   aligned(sizeof(func_ptr)), visibility ("hidden")))
 608   = { (func_ptr) 0 };
 609 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
 610 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
 611 STATIC func_ptr __DTOR_END__[1]
 612   __attribute__ ((used, aligned(sizeof(func_ptr))))
 613   = { (func_ptr) 0 };
 614 #else
 615 STATIC func_ptr __DTOR_END__[1]
 616   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
 617   = { (func_ptr) 0 };
 618 #endif
 619 #endif /* USE_INITFINI_ARRAY */
 620
 621 #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
 622 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
 623    this would be the 'length' field in a real FDE.  */
 624 # if __INT_MAX__ == 2147483647
 625 typedef int int32;
 626 # elif __LONG_MAX__ == 2147483647
 627 typedef long int32;
 628 # elif __SHRT_MAX__ == 2147483647
 629 typedef short int32;
 630 # else
 631 #  error "Missing a 4 byte integer"
 632 # endif
 633 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
 634      __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
 635                      aligned(sizeof(int32))))
 636      = { 0 };
 637 #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
 638
 639 #if USE_TM_CLONE_REGISTRY
 640 # ifndef HAVE_GAS_HIDDEN
 641 static
 642 # endif
 643 func_ptr __TMC_END__[]
 644   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
 645 # ifdef HAVE_GAS_HIDDEN
 646   __attribute__((__visibility__ ("hidden"))) = { };
 647 # else
 648   = { 0, 0 };
 649 # endif
 650 #endif /* USE_TM_CLONE_REGISTRY */
 651
 652 #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
 653
 654 /* If we are using .init_array, there is nothing to do.  */
 655
 656 #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
 657
 658 #ifdef OBJECT_FORMAT_ELF
 659 static void __attribute__((used))
 660 __do_global_ctors_aux (void)
 661 {
 662   func_ptr *p;
 663   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 664     (*p) ();
 665 }
 666
 667 /* Stick a call to __do_global_ctors_aux into the .init section.  */
 668 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
 669 #else  /* OBJECT_FORMAT_ELF */
 670
 671 /* Stick the real initialization code, followed by a normal sort of
 672    function epilogue at the very end of the .init section for this
 673    entire root executable file or for this entire shared library file.
 674
 675    Note that we use some tricks here to get *just* the body and just
 676    a function epilogue (but no function prologue) into the .init
 677    section of the crtend.o file.  Specifically, we switch to the .text
 678    section, start to define a function, and then we switch to the .init
 679    section just before the body code.
 680
 681    Earlier on, we put the corresponding function prologue into the .init
 682    section of the crtbegin.o file (which will be linked in first).
 683
 684    Note that we want to invoke all constructors for C++ file-scope static-
 685    storage objects AFTER any other possible initialization actions which
 686    may be performed by the code in the .init section contributions made by
 687    other libraries, etc.  That's because those other initializations may
 688    include setup operations for very primitive things (e.g. initializing
 689    the state of the floating-point coprocessor, etc.) which should be done
 690    before we start to execute any of the user's code.  */
 691
 692 static void
 693 __do_global_ctors_aux (void)    /* prologue goes in .text section */
 694 {
 695   asm (__LIBGCC_INIT_SECTION_ASM_OP__);
 696   DO_GLOBAL_CTORS_BODY;
 697   atexit (__do_global_dtors);
 698 }                               /* epilogue and body go in .init section */
 699
 700 FORCE_CODE_SECTION_ALIGN
 701 asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
 702
 703 #endif /* OBJECT_FORMAT_ELF */
 704
 705 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
 706
 707 extern void __do_global_ctors (void);
 708
 709 /* This case is used by the Irix 6 port, which supports named sections but
 710    not an SVR4-style .init section.  __do_global_ctors can be non-static
 711    in this case because we protect it with -hidden_symbol.  */
 712 void
 713 __do_global_ctors (void)
 714 {
 715   func_ptr *p;
 716 #if defined(USE_EH_FRAME_REGISTRY) \
 717     || defined(USE_TM_CLONE_REGISTRY)
 718   __do_global_ctors_1();
 719 #endif
 720   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 721     (*p) ();
 722 }
 723
 724 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
 725 #error "What are you doing with crtstuff.c, then?"
 726 #endif
 727
 728 #else /* ! CRT_BEGIN && ! CRT_END */
 729 #error "One of CRT_BEGIN or CRT_END must be defined."
 730 #endif