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) 1991-2014 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 #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) && !defined(USE_PT_GNU_EH_FRAME)
 135 # define USE_EH_FRAME_REGISTRY
 136 #endif
 137 #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) \
 138     && __LIBGCC_EH_TABLES_CAN_BE_READ_ONLY__
 139 # define EH_FRAME_SECTION_CONST const
 140 #else
 141 # define EH_FRAME_SECTION_CONST
 142 #endif
 143
 144 #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
 145     && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
 146 # define HIDDEN_DTOR_LIST_END
 147 #endif
 148
 149 #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
 150 # define USE_TM_CLONE_REGISTRY 1
 151 #endif
 152
 153 /* We do not want to add the weak attribute to the declarations of these
 154    routines in unwind-dw2-fde.h because that will cause the definition of
 155    these symbols to be weak as well.
 156
 157    This exposes a core issue, how to handle creating weak references vs
 158    how to create weak definitions.  Either we have to have the definition
 159    of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
 160    have a second declaration if we want a function's references to be weak,
 161    but not its definition.
 162
 163    Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
 164    one thinks about scaling to larger problems -- i.e., the condition under
 165    which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
 166    complicated.
 167
 168    So, we take an approach similar to #pragma weak -- we have a second
 169    declaration for functions that we want to have weak references.
 170
 171    Neither way is particularly good.  */
 172
 173 /* References to __register_frame_info and __deregister_frame_info should
 174    be weak in this file if at all possible.  */
 175 extern void __register_frame_info (const void *, struct object *)
 176                                   TARGET_ATTRIBUTE_WEAK;
 177 extern void __register_frame_info_bases (const void *, struct object *,
 178                                          void *, void *)
 179                                   TARGET_ATTRIBUTE_WEAK;
 180 extern void *__deregister_frame_info (const void *)
 181                                      TARGET_ATTRIBUTE_WEAK;
 182 extern void *__deregister_frame_info_bases (const void *)
 183                                      TARGET_ATTRIBUTE_WEAK;
 184 extern void __do_global_ctors_1 (void);
 185
 186 /* Likewise for _Jv_RegisterClasses.  */
 187 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
 188
 189 /* Likewise for transactional memory clone tables.  */
 190 extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
 191 extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
 192
 193 #ifdef OBJECT_FORMAT_ELF
 194
 195 /*  Declare a pointer to void function type.  */
 196 typedef void (*func_ptr) (void);
 197 #define STATIC static
 198
 199 #else  /* OBJECT_FORMAT_ELF */
 200
 201 #include "gbl-ctors.h"
 202
 203 #define STATIC
 204
 205 #endif /* OBJECT_FORMAT_ELF */
 206
 207 #ifdef CRT_BEGIN
 208
 209 /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
 210    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
 211    __DTOR_END__ } per root executable and also one set of these symbols
 212    per shared library.  So in any given whole process image, we may have
 213    multiple definitions of each of these symbols.  In order to prevent
 214    these definitions from conflicting with one another, and in order to
 215    ensure that the proper lists are used for the initialization/finalization
 216    of each individual shared library (respectively), we give these symbols
 217    only internal (i.e. `static') linkage, and we also make it a point to
 218    refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
 219    symbol in crtbegin.o, where they are defined.  */
 220
 221 /* No need for .ctors/.dtors section if linker can place them in
 222    .init_array/.fini_array section.  */
 223 #ifndef USE_INITFINI_ARRAY
 224 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
 225    does not start with a count of elements.  */
 226 #ifdef CTOR_LIST_BEGIN
 227 CTOR_LIST_BEGIN;
 228 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
 229 /* Hack: force cc1 to switch to .data section early, so that assembling
 230    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 231 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 232 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
 233 STATIC func_ptr __CTOR_LIST__[1]
 234   __attribute__ ((__used__, aligned(sizeof(func_ptr))))
 235   = { (func_ptr) (-1) };
 236 #else
 237 STATIC func_ptr __CTOR_LIST__[1]
 238   __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
 239   = { (func_ptr) (-1) };
 240 #endif /* __CTOR_LIST__ alternatives */
 241
 242 #ifdef DTOR_LIST_BEGIN
 243 DTOR_LIST_BEGIN;
 244 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
 245 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
 246 STATIC func_ptr __DTOR_LIST__[1]
 247   __attribute__ ((aligned(sizeof(func_ptr))))
 248   = { (func_ptr) (-1) };
 249 #else
 250 STATIC func_ptr __DTOR_LIST__[1]
 251   __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
 252   = { (func_ptr) (-1) };
 253 #endif /* __DTOR_LIST__ alternatives */
 254 #endif /* USE_INITFINI_ARRAY */
 255
 256 #ifdef USE_EH_FRAME_REGISTRY
 257 /* Stick a label at the beginning of the frame unwind info so we can register
 258    and deregister it with the exception handling library code.  */
 259 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
 260      __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4)))
 261      = { };
 262 #endif /* USE_EH_FRAME_REGISTRY */
 263
 264 #ifdef __LIBGCC_JCR_SECTION_NAME__
 265 /* Stick a label at the beginning of the java class registration info
 266    so we can register them properly.  */
 267 STATIC void *__JCR_LIST__[]
 268   __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__),
 269                   aligned(sizeof(void*))))
 270   = { };
 271 #endif /* __LIBGCC_JCR_SECTION_NAME__ */
 272
 273 #if USE_TM_CLONE_REGISTRY
 274 STATIC func_ptr __TMC_LIST__[]
 275   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*))))
 276   = { };
 277 # ifdef HAVE_GAS_HIDDEN
 278 extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
 279 # endif
 280
 281 static inline void
 282 deregister_tm_clones (void)
 283 {
 284   void (*fn) (void *);
 285
 286 #ifdef HAVE_GAS_HIDDEN
 287   if (__TMC_END__ - __TMC_LIST__ == 0)
 288     return;
 289 #else
 290   if (__TMC_LIST__[0] == NULL)
 291     return;
 292 #endif
 293
 294   fn = _ITM_deregisterTMCloneTable;
 295   __asm ("" : "+r" (fn));
 296   if (fn)
 297     fn (__TMC_LIST__);
 298 }
 299
 300 static inline void
 301 register_tm_clones (void)
 302 {
 303   void (*fn) (void *, size_t);
 304   size_t size;
 305
 306 #ifdef HAVE_GAS_HIDDEN
 307   size = (__TMC_END__ - __TMC_LIST__) / 2;
 308 #else
 309   for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
 310     continue;
 311 #endif
 312   if (size == 0)
 313     return;
 314
 315   fn = _ITM_registerTMCloneTable;
 316   __asm ("" : "+r" (fn));
 317   if (fn)
 318     fn (__TMC_LIST__, size);
 319 }
 320 #endif /* USE_TM_CLONE_REGISTRY */
 321
 322 #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
 323     || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
 324
 325 #ifdef OBJECT_FORMAT_ELF
 326
 327 /* Declare the __dso_handle variable.  It should have a unique value
 328    in every shared-object; in a main program its value is zero.  The
 329    object should in any case be protected.  This means the instance
 330    in one DSO or the main program is not used in another object.  The
 331    dynamic linker takes care of this.  */
 332
 333 #ifdef TARGET_LIBGCC_SDATA_SECTION
 334 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
 335 #endif
 336 #ifdef HAVE_GAS_HIDDEN
 337 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 338 #endif
 339 #ifdef CRTSTUFFS_O
 340 void *__dso_handle = &__dso_handle;
 341 #else
 342 void *__dso_handle = 0;
 343 #endif
 344
 345 /* The __cxa_finalize function may not be available so we use only a
 346    weak declaration.  */
 347 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
 348
 349 /* Run all the global destructors on exit from the program.  */
 350
 351 /* Some systems place the number of pointers in the first word of the
 352    table.  On SVR4 however, that word is -1.  In all cases, the table is
 353    null-terminated.  On SVR4, we start from the beginning of the list and
 354    invoke each per-compilation-unit destructor routine in order
 355    until we find that null.
 356
 357    Note that this function MUST be static.  There will be one of these
 358    functions in each root executable and one in each shared library, but
 359    although they all have the same code, each one is unique in that it
 360    refers to one particular associated `__DTOR_LIST__' which belongs to the
 361    same particular root executable or shared library file.
 362
 363    On some systems, this routine is run more than once from the .fini,
 364    when exit is called recursively, so we arrange to remember where in
 365    the list we left off processing, and we resume at that point,
 366    should we be re-invoked.  */
 367
 368 static void __attribute__((used))
 369 __do_global_dtors_aux (void)
 370 {
 371   static _Bool completed;
 372
 373   if (__builtin_expect (completed, 0))
 374     return;
 375
 376 #ifdef CRTSTUFFS_O
 377   if (__cxa_finalize)
 378     __cxa_finalize (__dso_handle);
 379 #endif
 380
 381 #ifdef FINI_ARRAY_SECTION_ASM_OP
 382   /* If we are using .fini_array then destructors will be run via that
 383      mechanism.  */
 384 #elif defined(HIDDEN_DTOR_LIST_END)
 385   {
 386     /* Safer version that makes sure only .dtors function pointers are
 387        called even if the static variable is maliciously changed.  */
 388     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
 389     static size_t dtor_idx;
 390     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
 391     func_ptr f;
 392
 393     while (dtor_idx < max_idx)
 394       {
 395         f = __DTOR_LIST__[++dtor_idx];
 396         f ();
 397       }
 398   }
 399 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
 400   {
 401     static func_ptr *p = __DTOR_LIST__ + 1;
 402     func_ptr f;
 403
 404     while ((f = *p))
 405       {
 406         p++;
 407         f ();
 408       }
 409   }
 410 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
 411
 412 #if USE_TM_CLONE_REGISTRY
 413   deregister_tm_clones ();
 414 #endif /* USE_TM_CLONE_REGISTRY */
 415
 416 #ifdef USE_EH_FRAME_REGISTRY
 417 #ifdef CRT_GET_RFIB_DATA
 418   /* If we used the new __register_frame_info_bases interface,
 419      make sure that we deregister from the same place.  */
 420   if (__deregister_frame_info_bases)
 421     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
 422 #else
 423   if (__deregister_frame_info)
 424     __deregister_frame_info (__EH_FRAME_BEGIN__);
 425 #endif
 426 #endif
 427
 428   completed = 1;
 429 }
 430
 431 /* Stick a call to __do_global_dtors_aux into the .fini section.  */
 432 #ifdef FINI_SECTION_ASM_OP
 433 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
 434 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
 435 static func_ptr __do_global_dtors_aux_fini_array_entry[]
 436   __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
 437   = { __do_global_dtors_aux };
 438 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
 439 static void __attribute__((used))
 440 __do_global_dtors_aux_1 (void)
 441 {
 442   atexit (__do_global_dtors_aux);
 443 }
 444 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
 445                           __do_global_dtors_aux_1)
 446 #endif
 447
 448 #if defined(USE_EH_FRAME_REGISTRY) \
 449     || defined(__LIBGCC_JCR_SECTION_NAME__) \
 450     || defined(USE_TM_CLONE_REGISTRY)
 451 /* Stick a call to __register_frame_info into the .init section.  For some
 452    reason calls with no arguments work more reliably in .init, so stick the
 453    call in another function.  */
 454
 455 static void __attribute__((used))
 456 frame_dummy (void)
 457 {
 458 #ifdef USE_EH_FRAME_REGISTRY
 459   static struct object object;
 460 #ifdef CRT_GET_RFIB_DATA
 461   void *tbase, *dbase;
 462   tbase = 0;
 463   CRT_GET_RFIB_DATA (dbase);
 464   if (__register_frame_info_bases)
 465     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
 466 #else
 467   if (__register_frame_info)
 468     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 469 #endif /* CRT_GET_RFIB_DATA */
 470 #endif /* USE_EH_FRAME_REGISTRY */
 471
 472 #ifdef __LIBGCC_JCR_SECTION_NAME__
 473   void **jcr_list;
 474   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
 475   if (__builtin_expect (*jcr_list != NULL, 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 /* __LIBGCC_JCR_SECTION_NAME__ */
 483
 484 #if USE_TM_CLONE_REGISTRY
 485   register_tm_clones ();
 486 #endif /* USE_TM_CLONE_REGISTRY */
 487 }
 488
 489 #ifdef __LIBGCC_INIT_SECTION_ASM_OP__
 490 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
 491 #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
 492 static func_ptr __frame_dummy_init_array_entry[]
 493   __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
 494   = { frame_dummy };
 495 #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
 496 #endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */
 497
 498 #else  /* OBJECT_FORMAT_ELF */
 499
 500 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
 501    and once in crtend.o).  It must be declared static to avoid a link
 502    error.  Here, we define __do_global_ctors as an externally callable
 503    function.  It is externally callable so that __main can invoke it when
 504    INVOKE__main is defined.  This has the additional effect of forcing cc1
 505    to switch to the .text section.  */
 506
 507 static void __do_global_ctors_aux (void);
 508 void
 509 __do_global_ctors (void)
 510 {
 511 #ifdef INVOKE__main
 512   /* If __main won't actually call __do_global_ctors then it doesn't matter
 513      what's inside the function.  The inside of __do_global_ctors_aux is
 514      called automatically in that case.  And the Alliant fx2800 linker
 515      crashes on this reference.  So prevent the crash.  */
 516   __do_global_ctors_aux ();
 517 #endif
 518 }
 519
 520 asm (__LIBGCC_INIT_SECTION_ASM_OP__);   /* cc1 doesn't know that we are switching! */
 521
 522 /* A routine to invoke all of the global constructors upon entry to the
 523    program.  We put this into the .init section (for systems that have
 524    such a thing) so that we can properly perform the construction of
 525    file-scope static-storage C++ objects within shared libraries.  */
 526
 527 static void __attribute__((used))
 528 __do_global_ctors_aux (void)    /* prologue goes in .init section */
 529 {
 530   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
 531   asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */
 532   DO_GLOBAL_CTORS_BODY;
 533   atexit (__do_global_dtors);
 534 }
 535
 536 #endif /* OBJECT_FORMAT_ELF */
 537
 538 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
 539
 540 extern void __do_global_dtors (void);
 541
 542 /* This case is used by the Irix 6 port, which supports named sections but
 543    not an SVR4-style .fini section.  __do_global_dtors can be non-static
 544    in this case because we protect it with -hidden_symbol.  */
 545
 546 void
 547 __do_global_dtors (void)
 548 {
 549   func_ptr *p, f;
 550   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
 551     f ();
 552
 553 #if USE_TM_CLONE_REGISTRY
 554   deregister_tm_clones ();
 555 #endif /* USE_TM_CLONE_REGISTRY */
 556
 557 #ifdef USE_EH_FRAME_REGISTRY
 558   if (__deregister_frame_info)
 559     __deregister_frame_info (__EH_FRAME_BEGIN__);
 560 #endif
 561 }
 562
 563 #if defined(USE_EH_FRAME_REGISTRY) \
 564     || defined(__LIBGCC_JCR_SECTION_NAME__) \
 565     || defined(USE_TM_CLONE_REGISTRY)
 566 /* A helper function for __do_global_ctors, which is in crtend.o.  Here
 567    in crtbegin.o, we can reference a couple of symbols not visible there.
 568    Plus, since we're before libgcc.a, we have no problems referencing
 569    functions from there.  */
 570 void
 571 __do_global_ctors_1(void)
 572 {
 573 #ifdef USE_EH_FRAME_REGISTRY
 574   static struct object object;
 575   if (__register_frame_info)
 576     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 577 #endif
 578
 579 #ifdef __LIBGCC_JCR_SECTION_NAME__
 580   void **jcr_list
 581   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
 582   if (__builtin_expect (*jcr_list != NULL, 0))
 583     {
 584       void (*register_classes) (void *) = _Jv_RegisterClasses;
 585       __asm ("" : "+r" (register_classes));
 586       if (register_classes)
 587         register_classes (jcr_list);
 588     }
 589 #endif
 590
 591 #if USE_TM_CLONE_REGISTRY
 592   register_tm_clones ();
 593 #endif /* USE_TM_CLONE_REGISTRY */
 594 }
 595 #endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */
 596
 597 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
 598 #error "What are you doing with crtstuff.c, then?"
 599 #endif
 600
 601 #elif defined(CRT_END) /* ! CRT_BEGIN */
 602
 603 /* No need for .ctors/.dtors section if linker can place them in
 604    .init_array/.fini_array section.  */
 605 #ifndef USE_INITFINI_ARRAY
 606 /* Put a word containing zero at the end of each of our two lists of function
 607    addresses.  Note that the words defined here go into the .ctors and .dtors
 608    sections of the crtend.o file, and since that file is always linked in
 609    last, these words naturally end up at the very ends of the two lists
 610    contained in these two sections.  */
 611
 612 #ifdef CTOR_LIST_END
 613 CTOR_LIST_END;
 614 #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
 615 /* Hack: force cc1 to switch to .data section early, so that assembling
 616    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 617 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 618 asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
 619 STATIC func_ptr __CTOR_END__[1]
 620   __attribute__((aligned(sizeof(func_ptr))))
 621   = { (func_ptr) 0 };
 622 #else
 623 STATIC func_ptr __CTOR_END__[1]
 624   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
 625   = { (func_ptr) 0 };
 626 #endif
 627
 628 #ifdef DTOR_LIST_END
 629 DTOR_LIST_END;
 630 #elif defined(HIDDEN_DTOR_LIST_END)
 631 #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
 632 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
 633 #endif
 634 func_ptr __DTOR_END__[1]
 635   __attribute__ ((used,
 636 #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
 637                   section(".dtors"),
 638 #endif
 639                   aligned(sizeof(func_ptr)), visibility ("hidden")))
 640   = { (func_ptr) 0 };
 641 #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
 642 asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
 643 STATIC func_ptr __DTOR_END__[1]
 644   __attribute__ ((used, aligned(sizeof(func_ptr))))
 645   = { (func_ptr) 0 };
 646 #else
 647 STATIC func_ptr __DTOR_END__[1]
 648   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
 649   = { (func_ptr) 0 };
 650 #endif
 651 #endif /* USE_INITFINI_ARRAY */
 652
 653 #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
 654 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
 655    this would be the 'length' field in a real FDE.  */
 656 # if __INT_MAX__ == 2147483647
 657 typedef int int32;
 658 # elif __LONG_MAX__ == 2147483647
 659 typedef long int32;
 660 # elif __SHRT_MAX__ == 2147483647
 661 typedef short int32;
 662 # else
 663 #  error "Missing a 4 byte integer"
 664 # endif
 665 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
 666      __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
 667                      aligned(sizeof(int32))))
 668      = { 0 };
 669 #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
 670
 671 #ifdef __LIBGCC_JCR_SECTION_NAME__
 672 /* Null terminate the .jcr section array.  */
 673 STATIC void *__JCR_END__[1]
 674    __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__),
 675                    aligned(sizeof(void *))))
 676    = { 0 };
 677 #endif /* __LIBGCC_JCR_SECTION_NAME__ */
 678
 679 #if USE_TM_CLONE_REGISTRY
 680 # ifndef HAVE_GAS_HIDDEN
 681 static
 682 # endif
 683 func_ptr __TMC_END__[]
 684   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
 685 # ifdef HAVE_GAS_HIDDEN
 686   __attribute__((__visibility__ ("hidden"))) = { };
 687 # else
 688   = { 0, 0 };
 689 # endif
 690 #endif /* USE_TM_CLONE_REGISTRY */
 691
 692 #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
 693
 694 /* If we are using .init_array, there is nothing to do.  */
 695
 696 #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
 697
 698 #ifdef OBJECT_FORMAT_ELF
 699 static void __attribute__((used))
 700 __do_global_ctors_aux (void)
 701 {
 702   func_ptr *p;
 703   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 704     (*p) ();
 705 }
 706
 707 /* Stick a call to __do_global_ctors_aux into the .init section.  */
 708 CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
 709 #else  /* OBJECT_FORMAT_ELF */
 710
 711 /* Stick the real initialization code, followed by a normal sort of
 712    function epilogue at the very end of the .init section for this
 713    entire root executable file or for this entire shared library file.
 714
 715    Note that we use some tricks here to get *just* the body and just
 716    a function epilogue (but no function prologue) into the .init
 717    section of the crtend.o file.  Specifically, we switch to the .text
 718    section, start to define a function, and then we switch to the .init
 719    section just before the body code.
 720
 721    Earlier on, we put the corresponding function prologue into the .init
 722    section of the crtbegin.o file (which will be linked in first).
 723
 724    Note that we want to invoke all constructors for C++ file-scope static-
 725    storage objects AFTER any other possible initialization actions which
 726    may be performed by the code in the .init section contributions made by
 727    other libraries, etc.  That's because those other initializations may
 728    include setup operations for very primitive things (e.g. initializing
 729    the state of the floating-point coprocessor, etc.) which should be done
 730    before we start to execute any of the user's code.  */
 731
 732 static void
 733 __do_global_ctors_aux (void)    /* prologue goes in .text section */
 734 {
 735   asm (__LIBGCC_INIT_SECTION_ASM_OP__);
 736   DO_GLOBAL_CTORS_BODY;
 737   atexit (__do_global_dtors);
 738 }                               /* epilogue and body go in .init section */
 739
 740 FORCE_CODE_SECTION_ALIGN
 741 asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
 742
 743 #endif /* OBJECT_FORMAT_ELF */
 744
 745 #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
 746
 747 extern void __do_global_ctors (void);
 748
 749 /* This case is used by the Irix 6 port, which supports named sections but
 750    not an SVR4-style .init section.  __do_global_ctors can be non-static
 751    in this case because we protect it with -hidden_symbol.  */
 752 void
 753 __do_global_ctors (void)
 754 {
 755   func_ptr *p;
 756 #if defined(USE_EH_FRAME_REGISTRY) \
 757     || defined(__LIBGCC_JCR_SECTION_NAME__) \
 758     || defined(USE_TM_CLONE_REGISTRY)
 759   __do_global_ctors_1();
 760 #endif
 761   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 762     (*p) ();
 763 }
 764
 765 #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
 766 #error "What are you doing with crtstuff.c, then?"
 767 #endif
 768
 769 #else /* ! CRT_BEGIN && ! CRT_END */
 770 #error "One of CRT_BEGIN or CRT_END must be defined."
 771 #endif