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, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
   4    2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011, 2012
   5    Free Software Foundation, Inc.
   6    Contributed by Ron Guilmette (rfg@monkeys.com).
   7
   8 This file is part of GCC.
   9
  10 GCC is free software; you can redistribute it and/or modify it under
  11 the terms of the GNU General Public License as published by the Free
  12 Software Foundation; either version 3, or (at your option) any later
  13 version.
  14
  15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18 for more details.
  19
  20 Under Section 7 of GPL version 3, you are granted additional
  21 permissions described in the GCC Runtime Library Exception, version
  22 3.1, as published by the Free Software Foundation.
  23
  24 You should have received a copy of the GNU General Public License and
  25 a copy of the GCC Runtime Library Exception along with this program;
  26 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  27 <http://www.gnu.org/licenses/>.  */
  28
  29 /* This file is a bit like libgcc2.c in that it is compiled
  30    multiple times and yields multiple .o files.
  31
  32    This file is useful on target machines where the object file format
  33    supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE).  On
  34    such systems, this file allows us to avoid running collect (or any
  35    other such slow and painful kludge).  Additionally, if the target
  36    system supports a .init section, this file allows us to support the
  37    linking of C++ code with a non-C++ main program.
  38
  39    Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then
  40    this file *will* make use of the .init section.  If that symbol is
  41    not defined however, then the .init section will not be used.
  42
  43    Currently, only ELF and COFF are supported.  It is likely however that
  44    ROSE could also be supported, if someone was willing to do the work to
  45    make whatever (small?) adaptations are needed.  (Some work may be
  46    needed on the ROSE assembler and linker also.)
  47
  48    This file must be compiled with gcc.  */
  49
  50 /* Target machine header files require this define. */
  51 #define IN_LIBGCC2
  52
  53 /* FIXME: Including auto-host is incorrect, but until we have
  54    identified the set of defines that need to go into auto-target.h,
  55    this will have to do.  */
  56 #include "auto-host.h"
  57 #undef pid_t
  58 #undef rlim_t
  59 #undef ssize_t
  60 #undef vfork
  61 #include "tconfig.h"
  62 #include "tsystem.h"
  63 #include "coretypes.h"
  64 #include "tm.h"
  65 #include "libgcc_tm.h"
  66 #include "unwind-dw2-fde.h"
  67
  68 #ifndef FORCE_CODE_SECTION_ALIGN
  69 # define FORCE_CODE_SECTION_ALIGN
  70 #endif
  71
  72 #ifndef CRT_CALL_STATIC_FUNCTION
  73 # define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)     \
  74 static void __attribute__((__used__))                   \
  75 call_ ## FUNC (void)                                    \
  76 {                                                       \
  77   asm (SECTION_OP);                                     \
  78   FUNC ();                                              \
  79   FORCE_CODE_SECTION_ALIGN                              \
  80   asm (TEXT_SECTION_ASM_OP);                            \
  81 }
  82 #endif
  83
  84 #if defined(OBJECT_FORMAT_ELF) \
  85     && !defined(OBJECT_FORMAT_FLAT) \
  86     && defined(HAVE_LD_EH_FRAME_HDR) \
  87     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
  88     && defined(__FreeBSD__) && __FreeBSD__ >= 7
  89 #include <link.h>
  90 # define USE_PT_GNU_EH_FRAME
  91 #endif
  92
  93 #if defined(OBJECT_FORMAT_ELF) \
  94     && !defined(OBJECT_FORMAT_FLAT) \
  95     && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR) \
  96     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
  97     && defined(__sun__) && defined(__svr4__)
  98 #include <link.h>
  99 # define USE_PT_GNU_EH_FRAME
 100 #endif
 101
 102 #if defined(OBJECT_FORMAT_ELF) \
 103     && !defined(OBJECT_FORMAT_FLAT) \
 104     && defined(HAVE_LD_EH_FRAME_HDR) \
 105     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
 106     && defined(__GLIBC__) && __GLIBC__ >= 2
 107 #include <link.h>
 108 /* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h.
 109    But it doesn't use PT_GNU_EH_FRAME ELF segment currently.  */
 110 # if !defined(__UCLIBC__) \
 111      && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
 112      || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
 113 #  define USE_PT_GNU_EH_FRAME
 114 # endif
 115 #endif
 116
 117 #if defined(OBJECT_FORMAT_ELF) \
 118     && !defined(OBJECT_FORMAT_FLAT) \
 119     && defined(HAVE_LD_EH_FRAME_HDR) \
 120     && !defined(CRTSTUFFT_O) \
 121     && defined(inhibit_libc) \
 122     && (defined(__GLIBC__) || defined(__gnu_linux__) || defined(__GNU__))
 123 /* On systems using glibc, an inhibit_libc build of libgcc is only
 124    part of a bootstrap process.  Build the same crt*.o as would be
 125    built with headers present, so that it is not necessary to build
 126    glibc more than once for the bootstrap to converge.  */
 127 # define USE_PT_GNU_EH_FRAME
 128 #endif
 129
 130 #if defined(EH_FRAME_SECTION_NAME) && !defined(USE_PT_GNU_EH_FRAME)
 131 # define USE_EH_FRAME_REGISTRY
 132 #endif
 133 #if defined(EH_FRAME_SECTION_NAME) && EH_TABLES_CAN_BE_READ_ONLY
 134 # define EH_FRAME_SECTION_CONST const
 135 #else
 136 # define EH_FRAME_SECTION_CONST
 137 #endif
 138
 139 #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
 140     && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
 141 # define HIDDEN_DTOR_LIST_END
 142 #endif
 143
 144 #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
 145 # define USE_TM_CLONE_REGISTRY 1
 146 #endif
 147
 148 /* We do not want to add the weak attribute to the declarations of these
 149    routines in unwind-dw2-fde.h because that will cause the definition of
 150    these symbols to be weak as well.
 151
 152    This exposes a core issue, how to handle creating weak references vs
 153    how to create weak definitions.  Either we have to have the definition
 154    of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
 155    have a second declaration if we want a function's references to be weak,
 156    but not its definition.
 157
 158    Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
 159    one thinks about scaling to larger problems -- i.e., the condition under
 160    which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
 161    complicated.
 162
 163    So, we take an approach similar to #pragma weak -- we have a second
 164    declaration for functions that we want to have weak references.
 165
 166    Neither way is particularly good.  */
 167
 168 /* References to __register_frame_info and __deregister_frame_info should
 169    be weak in this file if at all possible.  */
 170 extern void __register_frame_info (const void *, struct object *)
 171                                   TARGET_ATTRIBUTE_WEAK;
 172 extern void __register_frame_info_bases (const void *, struct object *,
 173                                          void *, void *)
 174                                   TARGET_ATTRIBUTE_WEAK;
 175 extern void *__deregister_frame_info (const void *)
 176                                      TARGET_ATTRIBUTE_WEAK;
 177 extern void *__deregister_frame_info_bases (const void *)
 178                                      TARGET_ATTRIBUTE_WEAK;
 179 extern void __do_global_ctors_1 (void);
 180
 181 /* Likewise for _Jv_RegisterClasses.  */
 182 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
 183
 184 /* Likewise for transactional memory clone tables.  */
 185 extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
 186 extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
 187
 188 #ifdef OBJECT_FORMAT_ELF
 189
 190 /*  Declare a pointer to void function type.  */
 191 typedef void (*func_ptr) (void);
 192 #define STATIC static
 193
 194 #else  /* OBJECT_FORMAT_ELF */
 195
 196 #include "gbl-ctors.h"
 197
 198 #define STATIC
 199
 200 #endif /* OBJECT_FORMAT_ELF */
 201
 202 #ifdef CRT_BEGIN
 203
 204 /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
 205    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
 206    __DTOR_END__ } per root executable and also one set of these symbols
 207    per shared library.  So in any given whole process image, we may have
 208    multiple definitions of each of these symbols.  In order to prevent
 209    these definitions from conflicting with one another, and in order to
 210    ensure that the proper lists are used for the initialization/finalization
 211    of each individual shared library (respectively), we give these symbols
 212    only internal (i.e. `static') linkage, and we also make it a point to
 213    refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
 214    symbol in crtbegin.o, where they are defined.  */
 215
 216 /* No need for .ctors/.dtors section if linker can place them in
 217    .init_array/.fini_array section.  */
 218 #ifndef USE_INITFINI_ARRAY
 219 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
 220    does not start with a count of elements.  */
 221 #ifdef CTOR_LIST_BEGIN
 222 CTOR_LIST_BEGIN;
 223 #elif defined(CTORS_SECTION_ASM_OP)
 224 /* Hack: force cc1 to switch to .data section early, so that assembling
 225    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 226 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 227 asm (CTORS_SECTION_ASM_OP);
 228 STATIC func_ptr __CTOR_LIST__[1]
 229   __attribute__ ((__used__, aligned(sizeof(func_ptr))))
 230   = { (func_ptr) (-1) };
 231 #else
 232 STATIC func_ptr __CTOR_LIST__[1]
 233   __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
 234   = { (func_ptr) (-1) };
 235 #endif /* __CTOR_LIST__ alternatives */
 236
 237 #ifdef DTOR_LIST_BEGIN
 238 DTOR_LIST_BEGIN;
 239 #elif defined(DTORS_SECTION_ASM_OP)
 240 asm (DTORS_SECTION_ASM_OP);
 241 STATIC func_ptr __DTOR_LIST__[1]
 242   __attribute__ ((aligned(sizeof(func_ptr))))
 243   = { (func_ptr) (-1) };
 244 #else
 245 STATIC func_ptr __DTOR_LIST__[1]
 246   __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
 247   = { (func_ptr) (-1) };
 248 #endif /* __DTOR_LIST__ alternatives */
 249 #endif /* USE_INITFINI_ARRAY */
 250
 251 #ifdef USE_EH_FRAME_REGISTRY
 252 /* Stick a label at the beginning of the frame unwind info so we can register
 253    and deregister it with the exception handling library code.  */
 254 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
 255      __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
 256      = { };
 257 #endif /* USE_EH_FRAME_REGISTRY */
 258
 259 #ifdef JCR_SECTION_NAME
 260 /* Stick a label at the beginning of the java class registration info
 261    so we can register them properly.  */
 262 STATIC void *__JCR_LIST__[]
 263   __attribute__ ((used, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
 264   = { };
 265 #endif /* JCR_SECTION_NAME */
 266
 267 #if USE_TM_CLONE_REGISTRY
 268 STATIC func_ptr __TMC_LIST__[]
 269   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*))))
 270   = { };
 271 # ifdef HAVE_GAS_HIDDEN
 272 extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
 273 # endif
 274
 275 static inline void
 276 deregister_tm_clones (void)
 277 {
 278   void (*fn) (void *);
 279
 280 #ifdef HAVE_GAS_HIDDEN
 281   if (__TMC_END__ - __TMC_LIST__ == 0)
 282     return;
 283 #else
 284   if (__TMC_LIST__[0] == NULL)
 285     return;
 286 #endif
 287
 288   fn = _ITM_deregisterTMCloneTable;
 289   __asm ("" : "+r" (fn));
 290   if (fn)
 291     fn (__TMC_LIST__);
 292 }
 293
 294 static inline void
 295 register_tm_clones (void)
 296 {
 297   void (*fn) (void *, size_t);
 298   size_t size;
 299
 300 #ifdef HAVE_GAS_HIDDEN
 301   size = (__TMC_END__ - __TMC_LIST__) / 2;
 302 #else
 303   for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
 304     continue;
 305 #endif
 306   if (size == 0)
 307     return;
 308
 309   fn = _ITM_registerTMCloneTable;
 310   __asm ("" : "+r" (fn));
 311   if (fn)
 312     fn (__TMC_LIST__, size);
 313 }
 314 #endif /* USE_TM_CLONE_REGISTRY */
 315
 316 #if defined(INIT_SECTION_ASM_OP) || defined(INIT_ARRAY_SECTION_ASM_OP)
 317
 318 #ifdef OBJECT_FORMAT_ELF
 319
 320 /* Declare the __dso_handle variable.  It should have a unique value
 321    in every shared-object; in a main program its value is zero.  The
 322    object should in any case be protected.  This means the instance
 323    in one DSO or the main program is not used in another object.  The
 324    dynamic linker takes care of this.  */
 325
 326 #ifdef TARGET_LIBGCC_SDATA_SECTION
 327 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
 328 #endif
 329 #ifdef HAVE_GAS_HIDDEN
 330 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 331 #endif
 332 #ifdef CRTSTUFFS_O
 333 void *__dso_handle = &__dso_handle;
 334 #else
 335 void *__dso_handle = 0;
 336 #endif
 337
 338 /* The __cxa_finalize function may not be available so we use only a
 339    weak declaration.  */
 340 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
 341
 342 /* Run all the global destructors on exit from the program.  */
 343
 344 /* Some systems place the number of pointers in the first word of the
 345    table.  On SVR4 however, that word is -1.  In all cases, the table is
 346    null-terminated.  On SVR4, we start from the beginning of the list and
 347    invoke each per-compilation-unit destructor routine in order
 348    until we find that null.
 349
 350    Note that this function MUST be static.  There will be one of these
 351    functions in each root executable and one in each shared library, but
 352    although they all have the same code, each one is unique in that it
 353    refers to one particular associated `__DTOR_LIST__' which belongs to the
 354    same particular root executable or shared library file.
 355
 356    On some systems, this routine is run more than once from the .fini,
 357    when exit is called recursively, so we arrange to remember where in
 358    the list we left off processing, and we resume at that point,
 359    should we be re-invoked.  */
 360
 361 static void __attribute__((used))
 362 __do_global_dtors_aux (void)
 363 {
 364   static _Bool completed;
 365
 366   if (__builtin_expect (completed, 0))
 367     return;
 368
 369 #ifdef CRTSTUFFS_O
 370   if (__cxa_finalize)
 371     __cxa_finalize (__dso_handle);
 372 #endif
 373
 374 #ifdef FINI_ARRAY_SECTION_ASM_OP
 375   /* If we are using .fini_array then destructors will be run via that
 376      mechanism.  */
 377 #elif defined(HIDDEN_DTOR_LIST_END)
 378   {
 379     /* Safer version that makes sure only .dtors function pointers are
 380        called even if the static variable is maliciously changed.  */
 381     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
 382     static size_t dtor_idx;
 383     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
 384     func_ptr f;
 385
 386     while (dtor_idx < max_idx)
 387       {
 388         f = __DTOR_LIST__[++dtor_idx];
 389         f ();
 390       }
 391   }
 392 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
 393   {
 394     static func_ptr *p = __DTOR_LIST__ + 1;
 395     func_ptr f;
 396
 397     while ((f = *p))
 398       {
 399         p++;
 400         f ();
 401       }
 402   }
 403 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
 404
 405 #if USE_TM_CLONE_REGISTRY
 406   deregister_tm_clones ();
 407 #endif /* USE_TM_CLONE_REGISTRY */
 408
 409 #ifdef USE_EH_FRAME_REGISTRY
 410 #ifdef CRT_GET_RFIB_DATA
 411   /* If we used the new __register_frame_info_bases interface,
 412      make sure that we deregister from the same place.  */
 413   if (__deregister_frame_info_bases)
 414     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
 415 #else
 416   if (__deregister_frame_info)
 417     __deregister_frame_info (__EH_FRAME_BEGIN__);
 418 #endif
 419 #endif
 420
 421   completed = 1;
 422 }
 423
 424 /* Stick a call to __do_global_dtors_aux into the .fini section.  */
 425 #ifdef FINI_SECTION_ASM_OP
 426 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
 427 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
 428 static func_ptr __do_global_dtors_aux_fini_array_entry[]
 429   __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
 430   = { __do_global_dtors_aux };
 431 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
 432 static void __attribute__((used))
 433 __do_global_dtors_aux_1 (void)
 434 {
 435   atexit (__do_global_dtors_aux);
 436 }
 437 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_dtors_aux_1)
 438 #endif
 439
 440 #if defined(USE_EH_FRAME_REGISTRY) \
 441     || defined(JCR_SECTION_NAME) \
 442     || defined(USE_TM_CLONE_REGISTRY)
 443 /* Stick a call to __register_frame_info into the .init section.  For some
 444    reason calls with no arguments work more reliably in .init, so stick the
 445    call in another function.  */
 446
 447 static void __attribute__((used))
 448 frame_dummy (void)
 449 {
 450 #ifdef USE_EH_FRAME_REGISTRY
 451   static struct object object;
 452 #ifdef CRT_GET_RFIB_DATA
 453   void *tbase, *dbase;
 454   tbase = 0;
 455   CRT_GET_RFIB_DATA (dbase);
 456   if (__register_frame_info_bases)
 457     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
 458 #else
 459   if (__register_frame_info)
 460     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 461 #endif /* CRT_GET_RFIB_DATA */
 462 #endif /* USE_EH_FRAME_REGISTRY */
 463
 464 #ifdef JCR_SECTION_NAME
 465   if (__JCR_LIST__[0])
 466     {
 467       void (*register_classes) (void *) = _Jv_RegisterClasses;
 468       __asm ("" : "+r" (register_classes));
 469       if (register_classes)
 470         register_classes (__JCR_LIST__);
 471     }
 472 #endif /* JCR_SECTION_NAME */
 473
 474 #if USE_TM_CLONE_REGISTRY
 475   register_tm_clones ();
 476 #endif /* USE_TM_CLONE_REGISTRY */
 477 }
 478
 479 #ifdef INIT_SECTION_ASM_OP
 480 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, frame_dummy)
 481 #else /* defined(INIT_SECTION_ASM_OP) */
 482 static func_ptr __frame_dummy_init_array_entry[]
 483   __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
 484   = { frame_dummy };
 485 #endif /* !defined(INIT_SECTION_ASM_OP) */
 486 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME || USE_TM_CLONE_REGISTRY */
 487
 488 #else  /* OBJECT_FORMAT_ELF */
 489
 490 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
 491    and once in crtend.o).  It must be declared static to avoid a link
 492    error.  Here, we define __do_global_ctors as an externally callable
 493    function.  It is externally callable so that __main can invoke it when
 494    INVOKE__main is defined.  This has the additional effect of forcing cc1
 495    to switch to the .text section.  */
 496
 497 static void __do_global_ctors_aux (void);
 498 void
 499 __do_global_ctors (void)
 500 {
 501 #ifdef INVOKE__main
 502   /* If __main won't actually call __do_global_ctors then it doesn't matter
 503      what's inside the function.  The inside of __do_global_ctors_aux is
 504      called automatically in that case.  And the Alliant fx2800 linker
 505      crashes on this reference.  So prevent the crash.  */
 506   __do_global_ctors_aux ();
 507 #endif
 508 }
 509
 510 asm (INIT_SECTION_ASM_OP);      /* cc1 doesn't know that we are switching! */
 511
 512 /* A routine to invoke all of the global constructors upon entry to the
 513    program.  We put this into the .init section (for systems that have
 514    such a thing) so that we can properly perform the construction of
 515    file-scope static-storage C++ objects within shared libraries.  */
 516
 517 static void __attribute__((used))
 518 __do_global_ctors_aux (void)    /* prologue goes in .init section */
 519 {
 520   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
 521   asm (TEXT_SECTION_ASM_OP);    /* don't put epilogue and body in .init */
 522   DO_GLOBAL_CTORS_BODY;
 523   atexit (__do_global_dtors);
 524 }
 525
 526 #endif /* OBJECT_FORMAT_ELF */
 527
 528 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 529
 530 extern void __do_global_dtors (void);
 531
 532 /* This case is used by the Irix 6 port, which supports named sections but
 533    not an SVR4-style .fini section.  __do_global_dtors can be non-static
 534    in this case because we protect it with -hidden_symbol.  */
 535
 536 void
 537 __do_global_dtors (void)
 538 {
 539   func_ptr *p, f;
 540   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
 541     f ();
 542
 543 #if USE_TM_CLONE_REGISTRY
 544   deregister_tm_clones ();
 545 #endif /* USE_TM_CLONE_REGISTRY */
 546
 547 #ifdef USE_EH_FRAME_REGISTRY
 548   if (__deregister_frame_info)
 549     __deregister_frame_info (__EH_FRAME_BEGIN__);
 550 #endif
 551 }
 552
 553 #if defined(USE_EH_FRAME_REGISTRY) \
 554     || defined(JCR_SECTION_NAME) \
 555     || defined(USE_TM_CLONE_REGISTRY)
 556 /* A helper function for __do_global_ctors, which is in crtend.o.  Here
 557    in crtbegin.o, we can reference a couple of symbols not visible there.
 558    Plus, since we're before libgcc.a, we have no problems referencing
 559    functions from there.  */
 560 void
 561 __do_global_ctors_1(void)
 562 {
 563 #ifdef USE_EH_FRAME_REGISTRY
 564   static struct object object;
 565   if (__register_frame_info)
 566     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 567 #endif
 568
 569 #ifdef JCR_SECTION_NAME
 570   if (__JCR_LIST__[0])
 571     {
 572       void (*register_classes) (void *) = _Jv_RegisterClasses;
 573       __asm ("" : "+r" (register_classes));
 574       if (register_classes)
 575         register_classes (__JCR_LIST__);
 576     }
 577 #endif
 578
 579 #if USE_TM_CLONE_REGISTRY
 580   register_tm_clones ();
 581 #endif /* USE_TM_CLONE_REGISTRY */
 582 }
 583 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME || USE_TM_CLONE_REGISTRY */
 584
 585 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 586 #error "What are you doing with crtstuff.c, then?"
 587 #endif
 588
 589 #elif defined(CRT_END) /* ! CRT_BEGIN */
 590
 591 /* No need for .ctors/.dtors section if linker can place them in
 592    .init_array/.fini_array section.  */
 593 #ifndef USE_INITFINI_ARRAY
 594 /* Put a word containing zero at the end of each of our two lists of function
 595    addresses.  Note that the words defined here go into the .ctors and .dtors
 596    sections of the crtend.o file, and since that file is always linked in
 597    last, these words naturally end up at the very ends of the two lists
 598    contained in these two sections.  */
 599
 600 #ifdef CTOR_LIST_END
 601 CTOR_LIST_END;
 602 #elif defined(CTORS_SECTION_ASM_OP)
 603 /* Hack: force cc1 to switch to .data section early, so that assembling
 604    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 605 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 606 asm (CTORS_SECTION_ASM_OP);
 607 STATIC func_ptr __CTOR_END__[1]
 608   __attribute__((aligned(sizeof(func_ptr))))
 609   = { (func_ptr) 0 };
 610 #else
 611 STATIC func_ptr __CTOR_END__[1]
 612   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
 613   = { (func_ptr) 0 };
 614 #endif
 615
 616 #ifdef DTOR_LIST_END
 617 DTOR_LIST_END;
 618 #elif defined(HIDDEN_DTOR_LIST_END)
 619 #ifdef DTORS_SECTION_ASM_OP
 620 asm (DTORS_SECTION_ASM_OP);
 621 #endif
 622 func_ptr __DTOR_END__[1]
 623   __attribute__ ((used,
 624 #ifndef DTORS_SECTION_ASM_OP
 625                   section(".dtors"),
 626 #endif
 627                   aligned(sizeof(func_ptr)), visibility ("hidden")))
 628   = { (func_ptr) 0 };
 629 #elif defined(DTORS_SECTION_ASM_OP)
 630 asm (DTORS_SECTION_ASM_OP);
 631 STATIC func_ptr __DTOR_END__[1]
 632   __attribute__ ((used, aligned(sizeof(func_ptr))))
 633   = { (func_ptr) 0 };
 634 #else
 635 STATIC func_ptr __DTOR_END__[1]
 636   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
 637   = { (func_ptr) 0 };
 638 #endif
 639 #endif /* USE_INITFINI_ARRAY */
 640
 641 #ifdef EH_FRAME_SECTION_NAME
 642 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
 643    this would be the 'length' field in a real FDE.  */
 644 # if __INT_MAX__ == 2147483647
 645 typedef int int32;
 646 # elif __LONG_MAX__ == 2147483647
 647 typedef long int32;
 648 # elif __SHRT_MAX__ == 2147483647
 649 typedef short int32;
 650 # else
 651 #  error "Missing a 4 byte integer"
 652 # endif
 653 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
 654      __attribute__ ((used, section(EH_FRAME_SECTION_NAME),
 655                      aligned(sizeof(int32))))
 656      = { 0 };
 657 #endif /* EH_FRAME_SECTION_NAME */
 658
 659 #ifdef JCR_SECTION_NAME
 660 /* Null terminate the .jcr section array.  */
 661 STATIC void *__JCR_END__[1]
 662    __attribute__ ((used, section(JCR_SECTION_NAME),
 663                    aligned(sizeof(void *))))
 664    = { 0 };
 665 #endif /* JCR_SECTION_NAME */
 666
 667 #if USE_TM_CLONE_REGISTRY
 668 # ifndef HAVE_GAS_HIDDEN
 669 static
 670 # endif
 671 func_ptr __TMC_END__[]
 672   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
 673 # ifdef HAVE_GAS_HIDDEN
 674   __attribute__((__visibility__ ("hidden"))) = { };
 675 # else
 676   = { 0, 0 };
 677 # endif
 678 #endif /* USE_TM_CLONE_REGISTRY */
 679
 680 #ifdef INIT_ARRAY_SECTION_ASM_OP
 681
 682 /* If we are using .init_array, there is nothing to do.  */
 683
 684 #elif defined(INIT_SECTION_ASM_OP)
 685
 686 #ifdef OBJECT_FORMAT_ELF
 687 static void __attribute__((used))
 688 __do_global_ctors_aux (void)
 689 {
 690   func_ptr *p;
 691   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 692     (*p) ();
 693 }
 694
 695 /* Stick a call to __do_global_ctors_aux into the .init section.  */
 696 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_ctors_aux)
 697 #else  /* OBJECT_FORMAT_ELF */
 698
 699 /* Stick the real initialization code, followed by a normal sort of
 700    function epilogue at the very end of the .init section for this
 701    entire root executable file or for this entire shared library file.
 702
 703    Note that we use some tricks here to get *just* the body and just
 704    a function epilogue (but no function prologue) into the .init
 705    section of the crtend.o file.  Specifically, we switch to the .text
 706    section, start to define a function, and then we switch to the .init
 707    section just before the body code.
 708
 709    Earlier on, we put the corresponding function prologue into the .init
 710    section of the crtbegin.o file (which will be linked in first).
 711
 712    Note that we want to invoke all constructors for C++ file-scope static-
 713    storage objects AFTER any other possible initialization actions which
 714    may be performed by the code in the .init section contributions made by
 715    other libraries, etc.  That's because those other initializations may
 716    include setup operations for very primitive things (e.g. initializing
 717    the state of the floating-point coprocessor, etc.) which should be done
 718    before we start to execute any of the user's code.  */
 719
 720 static void
 721 __do_global_ctors_aux (void)    /* prologue goes in .text section */
 722 {
 723   asm (INIT_SECTION_ASM_OP);
 724   DO_GLOBAL_CTORS_BODY;
 725   atexit (__do_global_dtors);
 726 }                               /* epilogue and body go in .init section */
 727
 728 FORCE_CODE_SECTION_ALIGN
 729 asm (TEXT_SECTION_ASM_OP);
 730
 731 #endif /* OBJECT_FORMAT_ELF */
 732
 733 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 734
 735 extern void __do_global_ctors (void);
 736
 737 /* This case is used by the Irix 6 port, which supports named sections but
 738    not an SVR4-style .init section.  __do_global_ctors can be non-static
 739    in this case because we protect it with -hidden_symbol.  */
 740 void
 741 __do_global_ctors (void)
 742 {
 743   func_ptr *p;
 744 #if defined(USE_EH_FRAME_REGISTRY) \
 745     || defined(JCR_SECTION_NAME) \
 746     || defined(USE_TM_CLONE_REGISTRY)
 747   __do_global_ctors_1();
 748 #endif
 749   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 750     (*p) ();
 751 }
 752
 753 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 754 #error "What are you doing with crtstuff.c, then?"
 755 #endif
 756
 757 #else /* ! CRT_BEGIN && ! CRT_END */
 758 #error "One of CRT_BEGIN or CRT_END must be defined."
 759 #endif