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, 2010 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) && defined(TARGET_DL_ITERATE_PHDR) \
  94     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
  95     && defined(__sun__) && defined(__svr4__)
  96 #include <link.h>
  97 # define USE_PT_GNU_EH_FRAME
  98 #endif
  99
 100 #if defined(OBJECT_FORMAT_ELF) \
 101     && !defined(OBJECT_FORMAT_FLAT) \
 102     && defined(HAVE_LD_EH_FRAME_HDR) \
 103     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
 104     && defined(__GLIBC__) && __GLIBC__ >= 2
 105 #include <link.h>
 106 /* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h.
 107    But it doesn't use PT_GNU_EH_FRAME ELF segment currently.  */
 108 # if !defined(__UCLIBC__) \
 109      && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
 110      || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
 111 #  define USE_PT_GNU_EH_FRAME
 112 # endif
 113 #endif
 114 #if defined(EH_FRAME_SECTION_NAME) && !defined(USE_PT_GNU_EH_FRAME)
 115 # define USE_EH_FRAME_REGISTRY
 116 #endif
 117 #if defined(EH_FRAME_SECTION_NAME) && EH_TABLES_CAN_BE_READ_ONLY
 118 # define EH_FRAME_SECTION_CONST const
 119 #else
 120 # define EH_FRAME_SECTION_CONST
 121 #endif
 122
 123 #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
 124     && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
 125 # define HIDDEN_DTOR_LIST_END
 126 #endif
 127
 128 /* We do not want to add the weak attribute to the declarations of these
 129    routines in unwind-dw2-fde.h because that will cause the definition of
 130    these symbols to be weak as well.
 131
 132    This exposes a core issue, how to handle creating weak references vs
 133    how to create weak definitions.  Either we have to have the definition
 134    of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
 135    have a second declaration if we want a function's references to be weak,
 136    but not its definition.
 137
 138    Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
 139    one thinks about scaling to larger problems -- i.e., the condition under
 140    which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
 141    complicated.
 142
 143    So, we take an approach similar to #pragma weak -- we have a second
 144    declaration for functions that we want to have weak references.
 145
 146    Neither way is particularly good.  */
 147
 148 /* References to __register_frame_info and __deregister_frame_info should
 149    be weak in this file if at all possible.  */
 150 extern void __register_frame_info (const void *, struct object *)
 151                                   TARGET_ATTRIBUTE_WEAK;
 152 extern void __register_frame_info_bases (const void *, struct object *,
 153                                          void *, void *)
 154                                   TARGET_ATTRIBUTE_WEAK;
 155 extern void *__deregister_frame_info (const void *)
 156                                      TARGET_ATTRIBUTE_WEAK;
 157 extern void *__deregister_frame_info_bases (const void *)
 158                                      TARGET_ATTRIBUTE_WEAK;
 159 extern void __do_global_ctors_1 (void);
 160
 161 /* Likewise for _Jv_RegisterClasses.  */
 162 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
 163
 164 #ifdef OBJECT_FORMAT_ELF
 165
 166 /*  Declare a pointer to void function type.  */
 167 typedef void (*func_ptr) (void);
 168 #define STATIC static
 169
 170 #else  /* OBJECT_FORMAT_ELF */
 171
 172 #include "gbl-ctors.h"
 173
 174 #define STATIC
 175
 176 #endif /* OBJECT_FORMAT_ELF */
 177
 178 #ifdef CRT_BEGIN
 179
 180 /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
 181    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
 182    __DTOR_END__ } per root executable and also one set of these symbols
 183    per shared library.  So in any given whole process image, we may have
 184    multiple definitions of each of these symbols.  In order to prevent
 185    these definitions from conflicting with one another, and in order to
 186    ensure that the proper lists are used for the initialization/finalization
 187    of each individual shared library (respectively), we give these symbols
 188    only internal (i.e. `static') linkage, and we also make it a point to
 189    refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
 190    symbol in crtbegin.o, where they are defined.  */
 191
 192 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
 193    does not start with a count of elements.  */
 194 #ifdef CTOR_LIST_BEGIN
 195 CTOR_LIST_BEGIN;
 196 #elif defined(CTORS_SECTION_ASM_OP)
 197 /* Hack: force cc1 to switch to .data section early, so that assembling
 198    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 199 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 200 asm (CTORS_SECTION_ASM_OP);
 201 STATIC func_ptr __CTOR_LIST__[1]
 202   __attribute__ ((__used__, aligned(sizeof(func_ptr))))
 203   = { (func_ptr) (-1) };
 204 #else
 205 STATIC func_ptr __CTOR_LIST__[1]
 206   __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
 207   = { (func_ptr) (-1) };
 208 #endif /* __CTOR_LIST__ alternatives */
 209
 210 #ifdef DTOR_LIST_BEGIN
 211 DTOR_LIST_BEGIN;
 212 #elif defined(DTORS_SECTION_ASM_OP)
 213 asm (DTORS_SECTION_ASM_OP);
 214 STATIC func_ptr __DTOR_LIST__[1]
 215   __attribute__ ((aligned(sizeof(func_ptr))))
 216   = { (func_ptr) (-1) };
 217 #else
 218 STATIC func_ptr __DTOR_LIST__[1]
 219   __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
 220   = { (func_ptr) (-1) };
 221 #endif /* __DTOR_LIST__ alternatives */
 222
 223 #ifdef USE_EH_FRAME_REGISTRY
 224 /* Stick a label at the beginning of the frame unwind info so we can register
 225    and deregister it with the exception handling library code.  */
 226 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
 227      __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
 228      = { };
 229 #endif /* USE_EH_FRAME_REGISTRY */
 230
 231 #ifdef JCR_SECTION_NAME
 232 /* Stick a label at the beginning of the java class registration info
 233    so we can register them properly.  */
 234 STATIC void *__JCR_LIST__[]
 235   __attribute__ ((used, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
 236   = { };
 237 #endif /* JCR_SECTION_NAME */
 238
 239 #if defined(INIT_SECTION_ASM_OP) || defined(INIT_ARRAY_SECTION_ASM_OP)
 240
 241 #ifdef OBJECT_FORMAT_ELF
 242
 243 /* Declare the __dso_handle variable.  It should have a unique value
 244    in every shared-object; in a main program its value is zero.  The
 245    object should in any case be protected.  This means the instance
 246    in one DSO or the main program is not used in another object.  The
 247    dynamic linker takes care of this.  */
 248
 249 #ifdef TARGET_LIBGCC_SDATA_SECTION
 250 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
 251 #endif
 252 #ifdef HAVE_GAS_HIDDEN
 253 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 254 #endif
 255 #ifdef CRTSTUFFS_O
 256 void *__dso_handle = &__dso_handle;
 257 #else
 258 void *__dso_handle = 0;
 259 #endif
 260
 261 /* The __cxa_finalize function may not be available so we use only a
 262    weak declaration.  */
 263 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
 264
 265 /* Run all the global destructors on exit from the program.  */
 266
 267 /* Some systems place the number of pointers in the first word of the
 268    table.  On SVR4 however, that word is -1.  In all cases, the table is
 269    null-terminated.  On SVR4, we start from the beginning of the list and
 270    invoke each per-compilation-unit destructor routine in order
 271    until we find that null.
 272
 273    Note that this function MUST be static.  There will be one of these
 274    functions in each root executable and one in each shared library, but
 275    although they all have the same code, each one is unique in that it
 276    refers to one particular associated `__DTOR_LIST__' which belongs to the
 277    same particular root executable or shared library file.
 278
 279    On some systems, this routine is run more than once from the .fini,
 280    when exit is called recursively, so we arrange to remember where in
 281    the list we left off processing, and we resume at that point,
 282    should we be re-invoked.  */
 283
 284 static void __attribute__((used))
 285 __do_global_dtors_aux (void)
 286 {
 287   static _Bool completed;
 288
 289   if (__builtin_expect (completed, 0))
 290     return;
 291
 292 #ifdef CRTSTUFFS_O
 293   if (__cxa_finalize)
 294     __cxa_finalize (__dso_handle);
 295 #endif
 296
 297 #ifdef FINI_ARRAY_SECTION_ASM_OP
 298   /* If we are using .fini_array then destructors will be run via that
 299      mechanism.  */
 300 #elif defined(HIDDEN_DTOR_LIST_END)
 301   {
 302     /* Safer version that makes sure only .dtors function pointers are
 303        called even if the static variable is maliciously changed.  */
 304     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
 305     static size_t dtor_idx;
 306     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
 307     func_ptr f;
 308
 309     while (dtor_idx < max_idx)
 310       {
 311         f = __DTOR_LIST__[++dtor_idx];
 312         f ();
 313       }
 314   }
 315 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
 316   {
 317     static func_ptr *p = __DTOR_LIST__ + 1;
 318     func_ptr f;
 319
 320     while ((f = *p))
 321       {
 322         p++;
 323         f ();
 324       }
 325   }
 326 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
 327
 328 #ifdef USE_EH_FRAME_REGISTRY
 329 #ifdef CRT_GET_RFIB_DATA
 330   /* If we used the new __register_frame_info_bases interface,
 331      make sure that we deregister from the same place.  */
 332   if (__deregister_frame_info_bases)
 333     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
 334 #else
 335   if (__deregister_frame_info)
 336     __deregister_frame_info (__EH_FRAME_BEGIN__);
 337 #endif
 338 #endif
 339
 340   completed = 1;
 341 }
 342
 343 /* Stick a call to __do_global_dtors_aux into the .fini section.  */
 344 #ifdef FINI_SECTION_ASM_OP
 345 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
 346 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
 347 static func_ptr __do_global_dtors_aux_fini_array_entry[]
 348   __attribute__ ((__used__, section(".fini_array")))
 349   = { __do_global_dtors_aux };
 350 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
 351 static void __attribute__((used))
 352 __do_global_dtors_aux_1 (void)
 353 {
 354   atexit (__do_global_dtors_aux);
 355 }
 356 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_dtors_aux_1)
 357 #endif
 358
 359 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
 360 /* Stick a call to __register_frame_info into the .init section.  For some
 361    reason calls with no arguments work more reliably in .init, so stick the
 362    call in another function.  */
 363
 364 static void __attribute__((used))
 365 frame_dummy (void)
 366 {
 367 #ifdef USE_EH_FRAME_REGISTRY
 368   static struct object object;
 369 #ifdef CRT_GET_RFIB_DATA
 370   void *tbase, *dbase;
 371   tbase = 0;
 372   CRT_GET_RFIB_DATA (dbase);
 373   if (__register_frame_info_bases)
 374     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
 375 #else
 376   if (__register_frame_info)
 377     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 378 #endif /* CRT_GET_RFIB_DATA */
 379 #endif /* USE_EH_FRAME_REGISTRY */
 380 #ifdef JCR_SECTION_NAME
 381   if (__JCR_LIST__[0])
 382     {
 383       void (*register_classes) (void *) = _Jv_RegisterClasses;
 384       __asm ("" : "+r" (register_classes));
 385       if (register_classes)
 386         register_classes (__JCR_LIST__);
 387     }
 388 #endif /* JCR_SECTION_NAME */
 389 }
 390
 391 #ifdef INIT_SECTION_ASM_OP
 392 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, frame_dummy)
 393 #else /* defined(INIT_SECTION_ASM_OP) */
 394 static func_ptr __frame_dummy_init_array_entry[]
 395   __attribute__ ((__used__, section(".init_array")))
 396   = { frame_dummy };
 397 #endif /* !defined(INIT_SECTION_ASM_OP) */
 398 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME */
 399
 400 #else  /* OBJECT_FORMAT_ELF */
 401
 402 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
 403    and once in crtend.o).  It must be declared static to avoid a link
 404    error.  Here, we define __do_global_ctors as an externally callable
 405    function.  It is externally callable so that __main can invoke it when
 406    INVOKE__main is defined.  This has the additional effect of forcing cc1
 407    to switch to the .text section.  */
 408
 409 static void __do_global_ctors_aux (void);
 410 void
 411 __do_global_ctors (void)
 412 {
 413 #ifdef INVOKE__main
 414   /* If __main won't actually call __do_global_ctors then it doesn't matter
 415      what's inside the function.  The inside of __do_global_ctors_aux is
 416      called automatically in that case.  And the Alliant fx2800 linker
 417      crashes on this reference.  So prevent the crash.  */
 418   __do_global_ctors_aux ();
 419 #endif
 420 }
 421
 422 asm (INIT_SECTION_ASM_OP);      /* cc1 doesn't know that we are switching! */
 423
 424 /* A routine to invoke all of the global constructors upon entry to the
 425    program.  We put this into the .init section (for systems that have
 426    such a thing) so that we can properly perform the construction of
 427    file-scope static-storage C++ objects within shared libraries.  */
 428
 429 static void __attribute__((used))
 430 __do_global_ctors_aux (void)    /* prologue goes in .init section */
 431 {
 432   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
 433   asm (TEXT_SECTION_ASM_OP);    /* don't put epilogue and body in .init */
 434   DO_GLOBAL_CTORS_BODY;
 435   atexit (__do_global_dtors);
 436 }
 437
 438 #endif /* OBJECT_FORMAT_ELF */
 439
 440 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 441
 442 extern void __do_global_dtors (void);
 443
 444 /* This case is used by the Irix 6 port, which supports named sections but
 445    not an SVR4-style .fini section.  __do_global_dtors can be non-static
 446    in this case because we protect it with -hidden_symbol.  */
 447
 448 void
 449 __do_global_dtors (void)
 450 {
 451   func_ptr *p, f;
 452   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
 453     f ();
 454
 455 #ifdef USE_EH_FRAME_REGISTRY
 456   if (__deregister_frame_info)
 457     __deregister_frame_info (__EH_FRAME_BEGIN__);
 458 #endif
 459 }
 460
 461 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
 462 /* A helper function for __do_global_ctors, which is in crtend.o.  Here
 463    in crtbegin.o, we can reference a couple of symbols not visible there.
 464    Plus, since we're before libgcc.a, we have no problems referencing
 465    functions from there.  */
 466 void
 467 __do_global_ctors_1(void)
 468 {
 469 #ifdef USE_EH_FRAME_REGISTRY
 470   static struct object object;
 471   if (__register_frame_info)
 472     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 473 #endif
 474 #ifdef JCR_SECTION_NAME
 475   if (__JCR_LIST__[0])
 476     {
 477       void (*register_classes) (void *) = _Jv_RegisterClasses;
 478       __asm ("" : "+r" (register_classes));
 479       if (register_classes)
 480         register_classes (__JCR_LIST__);
 481     }
 482 #endif
 483 }
 484 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME */
 485
 486 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 487 #error "What are you doing with crtstuff.c, then?"
 488 #endif
 489
 490 #elif defined(CRT_END) /* ! CRT_BEGIN */
 491
 492 /* Put a word containing zero at the end of each of our two lists of function
 493    addresses.  Note that the words defined here go into the .ctors and .dtors
 494    sections of the crtend.o file, and since that file is always linked in
 495    last, these words naturally end up at the very ends of the two lists
 496    contained in these two sections.  */
 497
 498 #ifdef CTOR_LIST_END
 499 CTOR_LIST_END;
 500 #elif defined(CTORS_SECTION_ASM_OP)
 501 /* Hack: force cc1 to switch to .data section early, so that assembling
 502    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 503 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 504 asm (CTORS_SECTION_ASM_OP);
 505 STATIC func_ptr __CTOR_END__[1]
 506   __attribute__((aligned(sizeof(func_ptr))))
 507   = { (func_ptr) 0 };
 508 #else
 509 STATIC func_ptr __CTOR_END__[1]
 510   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
 511   = { (func_ptr) 0 };
 512 #endif
 513
 514 #ifdef DTOR_LIST_END
 515 DTOR_LIST_END;
 516 #elif defined(HIDDEN_DTOR_LIST_END)
 517 #ifdef DTORS_SECTION_ASM_OP
 518 asm (DTORS_SECTION_ASM_OP);
 519 #endif
 520 func_ptr __DTOR_END__[1]
 521   __attribute__ ((used,
 522 #ifndef DTORS_SECTION_ASM_OP
 523                   section(".dtors"),
 524 #endif
 525                   aligned(sizeof(func_ptr)), visibility ("hidden")))
 526   = { (func_ptr) 0 };
 527 #elif defined(DTORS_SECTION_ASM_OP)
 528 asm (DTORS_SECTION_ASM_OP);
 529 STATIC func_ptr __DTOR_END__[1]
 530   __attribute__ ((used, aligned(sizeof(func_ptr))))
 531   = { (func_ptr) 0 };
 532 #else
 533 STATIC func_ptr __DTOR_END__[1]
 534   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
 535   = { (func_ptr) 0 };
 536 #endif
 537
 538 #ifdef EH_FRAME_SECTION_NAME
 539 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
 540    this would be the 'length' field in a real FDE.  */
 541 # if __INT_MAX__ == 2147483647
 542 typedef int int32;
 543 # elif __LONG_MAX__ == 2147483647
 544 typedef long int32;
 545 # elif __SHRT_MAX__ == 2147483647
 546 typedef short int32;
 547 # else
 548 #  error "Missing a 4 byte integer"
 549 # endif
 550 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
 551      __attribute__ ((used, section(EH_FRAME_SECTION_NAME),
 552                      aligned(sizeof(int32))))
 553      = { 0 };
 554 #endif /* EH_FRAME_SECTION_NAME */
 555
 556 #ifdef JCR_SECTION_NAME
 557 /* Null terminate the .jcr section array.  */
 558 STATIC void *__JCR_END__[1]
 559    __attribute__ ((used, section(JCR_SECTION_NAME),
 560                    aligned(sizeof(void *))))
 561    = { 0 };
 562 #endif /* JCR_SECTION_NAME */
 563
 564 #ifdef INIT_ARRAY_SECTION_ASM_OP
 565
 566 /* If we are using .init_array, there is nothing to do.  */
 567
 568 #elif defined(INIT_SECTION_ASM_OP)
 569
 570 #ifdef OBJECT_FORMAT_ELF
 571 static void __attribute__((used))
 572 __do_global_ctors_aux (void)
 573 {
 574   func_ptr *p;
 575   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 576     (*p) ();
 577 }
 578
 579 /* Stick a call to __do_global_ctors_aux into the .init section.  */
 580 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_ctors_aux)
 581 #else  /* OBJECT_FORMAT_ELF */
 582
 583 /* Stick the real initialization code, followed by a normal sort of
 584    function epilogue at the very end of the .init section for this
 585    entire root executable file or for this entire shared library file.
 586
 587    Note that we use some tricks here to get *just* the body and just
 588    a function epilogue (but no function prologue) into the .init
 589    section of the crtend.o file.  Specifically, we switch to the .text
 590    section, start to define a function, and then we switch to the .init
 591    section just before the body code.
 592
 593    Earlier on, we put the corresponding function prologue into the .init
 594    section of the crtbegin.o file (which will be linked in first).
 595
 596    Note that we want to invoke all constructors for C++ file-scope static-
 597    storage objects AFTER any other possible initialization actions which
 598    may be performed by the code in the .init section contributions made by
 599    other libraries, etc.  That's because those other initializations may
 600    include setup operations for very primitive things (e.g. initializing
 601    the state of the floating-point coprocessor, etc.) which should be done
 602    before we start to execute any of the user's code.  */
 603
 604 static void
 605 __do_global_ctors_aux (void)    /* prologue goes in .text section */
 606 {
 607   asm (INIT_SECTION_ASM_OP);
 608   DO_GLOBAL_CTORS_BODY;
 609   atexit (__do_global_dtors);
 610 }                               /* epilogue and body go in .init section */
 611
 612 FORCE_CODE_SECTION_ALIGN
 613 asm (TEXT_SECTION_ASM_OP);
 614
 615 #endif /* OBJECT_FORMAT_ELF */
 616
 617 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 618
 619 extern void __do_global_ctors (void);
 620
 621 /* This case is used by the Irix 6 port, which supports named sections but
 622    not an SVR4-style .init section.  __do_global_ctors can be non-static
 623    in this case because we protect it with -hidden_symbol.  */
 624 void
 625 __do_global_ctors (void)
 626 {
 627   func_ptr *p;
 628 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
 629   __do_global_ctors_1();
 630 #endif
 631   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 632     (*p) ();
 633 }
 634
 635 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 636 #error "What are you doing with crtstuff.c, then?"
 637 #endif
 638
 639 #else /* ! CRT_BEGIN && ! CRT_END */
 640 #error "One of CRT_BEGIN or CRT_END must be defined."
 641 #endif