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