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 pid_t
  56 #undef rlim_t
  57 #undef ssize_t
  58 #undef vfork
  59 #include "tconfig.h"
  60 #include "tsystem.h"
  61 #include "coretypes.h"
  62 #include "tm.h"
  63 #include "libgcc_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(TARGET_DL_ITERATE_PHDR) && \
  83    (defined(__DragonFly__) || defined(__FreeBSD__))
  84 #define BSD_DL_ITERATE_PHDR_AVAILABLE
  85 #endif
  86
  87 #if defined(OBJECT_FORMAT_ELF) \
  88     && !defined(OBJECT_FORMAT_FLAT) \
  89     && defined(HAVE_LD_EH_FRAME_HDR) \
  90     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
  91     && defined(BSD_DL_ITERATE_PHDR_AVAILABLE)
  92 #include <link.h>
  93 # define USE_PT_GNU_EH_FRAME
  94 #endif
  95
  96 #if defined(OBJECT_FORMAT_ELF) \
  97     && !defined(OBJECT_FORMAT_FLAT) \
  98     && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR) \
  99     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
 100     && defined(__sun__) && defined(__svr4__)
 101 #include <link.h>
 102 # define USE_PT_GNU_EH_FRAME
 103 #endif
 104
 105 #if defined(OBJECT_FORMAT_ELF) \
 106     && !defined(OBJECT_FORMAT_FLAT) \
 107     && defined(HAVE_LD_EH_FRAME_HDR) \
 108     && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
 109     && defined(__GLIBC__) && __GLIBC__ >= 2
 110 #include <link.h>
 111 /* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h.
 112    But it doesn't use PT_GNU_EH_FRAME ELF segment currently.  */
 113 # if !defined(__UCLIBC__) \
 114      && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
 115      || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
 116 #  define USE_PT_GNU_EH_FRAME
 117 # endif
 118 #endif
 119
 120 #if defined(OBJECT_FORMAT_ELF) \
 121     && !defined(OBJECT_FORMAT_FLAT) \
 122     && defined(HAVE_LD_EH_FRAME_HDR) \
 123     && !defined(CRTSTUFFT_O) \
 124     && defined(inhibit_libc) \
 125     && (defined(__GLIBC__) || defined(__gnu_linux__) || defined(__GNU__))
 126 /* On systems using glibc, an inhibit_libc build of libgcc is only
 127    part of a bootstrap process.  Build the same crt*.o as would be
 128    built with headers present, so that it is not necessary to build
 129    glibc more than once for the bootstrap to converge.  */
 130 # define USE_PT_GNU_EH_FRAME
 131 #endif
 132
 133 #if defined(EH_FRAME_SECTION_NAME) && !defined(USE_PT_GNU_EH_FRAME)
 134 # define USE_EH_FRAME_REGISTRY
 135 #endif
 136 #if defined(EH_FRAME_SECTION_NAME) && EH_TABLES_CAN_BE_READ_ONLY
 137 # define EH_FRAME_SECTION_CONST const
 138 #else
 139 # define EH_FRAME_SECTION_CONST
 140 #endif
 141
 142 #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
 143     && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
 144 # define HIDDEN_DTOR_LIST_END
 145 #endif
 146
 147 #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
 148 # define USE_TM_CLONE_REGISTRY 1
 149 #endif
 150
 151 /* We do not want to add the weak attribute to the declarations of these
 152    routines in unwind-dw2-fde.h because that will cause the definition of
 153    these symbols to be weak as well.
 154
 155    This exposes a core issue, how to handle creating weak references vs
 156    how to create weak definitions.  Either we have to have the definition
 157    of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
 158    have a second declaration if we want a function's references to be weak,
 159    but not its definition.
 160
 161    Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
 162    one thinks about scaling to larger problems -- i.e., the condition under
 163    which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
 164    complicated.
 165
 166    So, we take an approach similar to #pragma weak -- we have a second
 167    declaration for functions that we want to have weak references.
 168
 169    Neither way is particularly good.  */
 170
 171 /* References to __register_frame_info and __deregister_frame_info should
 172    be weak in this file if at all possible.  */
 173 extern void __register_frame_info (const void *, struct object *)
 174                                   TARGET_ATTRIBUTE_WEAK;
 175 extern void __register_frame_info_bases (const void *, struct object *,
 176                                          void *, void *)
 177                                   TARGET_ATTRIBUTE_WEAK;
 178 extern void *__deregister_frame_info (const void *)
 179                                      TARGET_ATTRIBUTE_WEAK;
 180 extern void *__deregister_frame_info_bases (const void *)
 181                                      TARGET_ATTRIBUTE_WEAK;
 182 extern void __do_global_ctors_1 (void);
 183
 184 /* Likewise for _Jv_RegisterClasses.  */
 185 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
 186
 187 /* Likewise for transactional memory clone tables.  */
 188 extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
 189 extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
 190
 191 #ifdef OBJECT_FORMAT_ELF
 192
 193 /*  Declare a pointer to void function type.  */
 194 typedef void (*func_ptr) (void);
 195 #define STATIC static
 196
 197 #else  /* OBJECT_FORMAT_ELF */
 198
 199 #include "gbl-ctors.h"
 200
 201 #define STATIC
 202
 203 #endif /* OBJECT_FORMAT_ELF */
 204
 205 #ifdef CRT_BEGIN
 206
 207 /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
 208    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
 209    __DTOR_END__ } per root executable and also one set of these symbols
 210    per shared library.  So in any given whole process image, we may have
 211    multiple definitions of each of these symbols.  In order to prevent
 212    these definitions from conflicting with one another, and in order to
 213    ensure that the proper lists are used for the initialization/finalization
 214    of each individual shared library (respectively), we give these symbols
 215    only internal (i.e. `static') linkage, and we also make it a point to
 216    refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
 217    symbol in crtbegin.o, where they are defined.  */
 218
 219 /* No need for .ctors/.dtors section if linker can place them in
 220    .init_array/.fini_array section.  */
 221 #ifndef USE_INITFINI_ARRAY
 222 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
 223    does not start with a count of elements.  */
 224 #ifdef CTOR_LIST_BEGIN
 225 CTOR_LIST_BEGIN;
 226 #elif defined(CTORS_SECTION_ASM_OP)
 227 /* Hack: force cc1 to switch to .data section early, so that assembling
 228    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 229 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 230 asm (CTORS_SECTION_ASM_OP);
 231 STATIC func_ptr __CTOR_LIST__[1]
 232   __attribute__ ((__used__, aligned(sizeof(func_ptr))))
 233   = { (func_ptr) (-1) };
 234 #else
 235 STATIC func_ptr __CTOR_LIST__[1]
 236   __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
 237   = { (func_ptr) (-1) };
 238 #endif /* __CTOR_LIST__ alternatives */
 239
 240 #ifdef DTOR_LIST_BEGIN
 241 DTOR_LIST_BEGIN;
 242 #elif defined(DTORS_SECTION_ASM_OP)
 243 asm (DTORS_SECTION_ASM_OP);
 244 STATIC func_ptr __DTOR_LIST__[1]
 245   __attribute__ ((aligned(sizeof(func_ptr))))
 246   = { (func_ptr) (-1) };
 247 #else
 248 STATIC func_ptr __DTOR_LIST__[1]
 249   __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
 250   = { (func_ptr) (-1) };
 251 #endif /* __DTOR_LIST__ alternatives */
 252 #endif /* USE_INITFINI_ARRAY */
 253
 254 #ifdef USE_EH_FRAME_REGISTRY
 255 /* Stick a label at the beginning of the frame unwind info so we can register
 256    and deregister it with the exception handling library code.  */
 257 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
 258      __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
 259      = { };
 260 #endif /* USE_EH_FRAME_REGISTRY */
 261
 262 #ifdef JCR_SECTION_NAME
 263 /* Stick a label at the beginning of the java class registration info
 264    so we can register them properly.  */
 265 STATIC void *__JCR_LIST__[]
 266   __attribute__ ((used, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
 267   = { };
 268 #endif /* JCR_SECTION_NAME */
 269
 270 #if USE_TM_CLONE_REGISTRY
 271 STATIC func_ptr __TMC_LIST__[]
 272   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*))))
 273   = { };
 274 # ifdef HAVE_GAS_HIDDEN
 275 extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
 276 # endif
 277
 278 static inline void
 279 deregister_tm_clones (void)
 280 {
 281   void (*fn) (void *);
 282
 283 #ifdef HAVE_GAS_HIDDEN
 284   if (__TMC_END__ - __TMC_LIST__ == 0)
 285     return;
 286 #else
 287   if (__TMC_LIST__[0] == NULL)
 288     return;
 289 #endif
 290
 291   fn = _ITM_deregisterTMCloneTable;
 292   __asm ("" : "+r" (fn));
 293   if (fn)
 294     fn (__TMC_LIST__);
 295 }
 296
 297 static inline void
 298 register_tm_clones (void)
 299 {
 300   void (*fn) (void *, size_t);
 301   size_t size;
 302
 303 #ifdef HAVE_GAS_HIDDEN
 304   size = (__TMC_END__ - __TMC_LIST__) / 2;
 305 #else
 306   for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
 307     continue;
 308 #endif
 309   if (size == 0)
 310     return;
 311
 312   fn = _ITM_registerTMCloneTable;
 313   __asm ("" : "+r" (fn));
 314   if (fn)
 315     fn (__TMC_LIST__, size);
 316 }
 317 #endif /* USE_TM_CLONE_REGISTRY */
 318
 319 #if defined(INIT_SECTION_ASM_OP) || defined(INIT_ARRAY_SECTION_ASM_OP)
 320
 321 #ifdef OBJECT_FORMAT_ELF
 322
 323 /* Declare the __dso_handle variable.  It should have a unique value
 324    in every shared-object; in a main program its value is zero.  The
 325    object should in any case be protected.  This means the instance
 326    in one DSO or the main program is not used in another object.  The
 327    dynamic linker takes care of this.  */
 328
 329 #ifdef TARGET_LIBGCC_SDATA_SECTION
 330 extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
 331 #endif
 332 #ifdef HAVE_GAS_HIDDEN
 333 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 334 #endif
 335 #ifdef CRTSTUFFS_O
 336 void *__dso_handle = &__dso_handle;
 337 #else
 338 void *__dso_handle = 0;
 339 #endif
 340
 341 /* The __cxa_finalize function may not be available so we use only a
 342    weak declaration.  */
 343 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
 344
 345 /* Run all the global destructors on exit from the program.  */
 346
 347 /* Some systems place the number of pointers in the first word of the
 348    table.  On SVR4 however, that word is -1.  In all cases, the table is
 349    null-terminated.  On SVR4, we start from the beginning of the list and
 350    invoke each per-compilation-unit destructor routine in order
 351    until we find that null.
 352
 353    Note that this function MUST be static.  There will be one of these
 354    functions in each root executable and one in each shared library, but
 355    although they all have the same code, each one is unique in that it
 356    refers to one particular associated `__DTOR_LIST__' which belongs to the
 357    same particular root executable or shared library file.
 358
 359    On some systems, this routine is run more than once from the .fini,
 360    when exit is called recursively, so we arrange to remember where in
 361    the list we left off processing, and we resume at that point,
 362    should we be re-invoked.  */
 363
 364 static void __attribute__((used))
 365 __do_global_dtors_aux (void)
 366 {
 367   static _Bool completed;
 368
 369   if (__builtin_expect (completed, 0))
 370     return;
 371
 372 #ifdef CRTSTUFFS_O
 373   if (__cxa_finalize)
 374     __cxa_finalize (__dso_handle);
 375 #endif
 376
 377 #ifdef FINI_ARRAY_SECTION_ASM_OP
 378   /* If we are using .fini_array then destructors will be run via that
 379      mechanism.  */
 380 #elif defined(HIDDEN_DTOR_LIST_END)
 381   {
 382     /* Safer version that makes sure only .dtors function pointers are
 383        called even if the static variable is maliciously changed.  */
 384     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
 385     static size_t dtor_idx;
 386     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
 387     func_ptr f;
 388
 389     while (dtor_idx < max_idx)
 390       {
 391         f = __DTOR_LIST__[++dtor_idx];
 392         f ();
 393       }
 394   }
 395 #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
 396   {
 397     static func_ptr *p = __DTOR_LIST__ + 1;
 398     func_ptr f;
 399
 400     while ((f = *p))
 401       {
 402         p++;
 403         f ();
 404       }
 405   }
 406 #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
 407
 408 #if USE_TM_CLONE_REGISTRY
 409   deregister_tm_clones ();
 410 #endif /* USE_TM_CLONE_REGISTRY */
 411
 412 #ifdef USE_EH_FRAME_REGISTRY
 413 #ifdef CRT_GET_RFIB_DATA
 414   /* If we used the new __register_frame_info_bases interface,
 415      make sure that we deregister from the same place.  */
 416   if (__deregister_frame_info_bases)
 417     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
 418 #else
 419   if (__deregister_frame_info)
 420     __deregister_frame_info (__EH_FRAME_BEGIN__);
 421 #endif
 422 #endif
 423
 424   completed = 1;
 425 }
 426
 427 /* Stick a call to __do_global_dtors_aux into the .fini section.  */
 428 #ifdef FINI_SECTION_ASM_OP
 429 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
 430 #elif defined (FINI_ARRAY_SECTION_ASM_OP)
 431 static func_ptr __do_global_dtors_aux_fini_array_entry[]
 432   __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
 433   = { __do_global_dtors_aux };
 434 #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
 435 static void __attribute__((used))
 436 __do_global_dtors_aux_1 (void)
 437 {
 438   atexit (__do_global_dtors_aux);
 439 }
 440 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_dtors_aux_1)
 441 #endif
 442
 443 #if defined(USE_EH_FRAME_REGISTRY) \
 444     || defined(JCR_SECTION_NAME) \
 445     || defined(USE_TM_CLONE_REGISTRY)
 446 /* Stick a call to __register_frame_info into the .init section.  For some
 447    reason calls with no arguments work more reliably in .init, so stick the
 448    call in another function.  */
 449
 450 static void __attribute__((used))
 451 frame_dummy (void)
 452 {
 453 #ifdef USE_EH_FRAME_REGISTRY
 454   static struct object object;
 455 #ifdef CRT_GET_RFIB_DATA
 456   void *tbase, *dbase;
 457   tbase = 0;
 458   CRT_GET_RFIB_DATA (dbase);
 459   if (__register_frame_info_bases)
 460     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
 461 #else
 462   if (__register_frame_info)
 463     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 464 #endif /* CRT_GET_RFIB_DATA */
 465 #endif /* USE_EH_FRAME_REGISTRY */
 466
 467 #ifdef JCR_SECTION_NAME
 468   void **jcr_list;
 469   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
 470   if (__builtin_expect (*jcr_list != NULL, 0))
 471     {
 472       void (*register_classes) (void *) = _Jv_RegisterClasses;
 473       __asm ("" : "+r" (register_classes));
 474       if (register_classes)
 475         register_classes (jcr_list);
 476     }
 477 #endif /* JCR_SECTION_NAME */
 478
 479 #if USE_TM_CLONE_REGISTRY
 480   register_tm_clones ();
 481 #endif /* USE_TM_CLONE_REGISTRY */
 482 }
 483
 484 #ifdef INIT_SECTION_ASM_OP
 485 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, frame_dummy)
 486 #else /* defined(INIT_SECTION_ASM_OP) */
 487 static func_ptr __frame_dummy_init_array_entry[]
 488   __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
 489   = { frame_dummy };
 490 #endif /* !defined(INIT_SECTION_ASM_OP) */
 491 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME || USE_TM_CLONE_REGISTRY */
 492
 493 #else  /* OBJECT_FORMAT_ELF */
 494
 495 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
 496    and once in crtend.o).  It must be declared static to avoid a link
 497    error.  Here, we define __do_global_ctors as an externally callable
 498    function.  It is externally callable so that __main can invoke it when
 499    INVOKE__main is defined.  This has the additional effect of forcing cc1
 500    to switch to the .text section.  */
 501
 502 static void __do_global_ctors_aux (void);
 503 void
 504 __do_global_ctors (void)
 505 {
 506 #ifdef INVOKE__main
 507   /* If __main won't actually call __do_global_ctors then it doesn't matter
 508      what's inside the function.  The inside of __do_global_ctors_aux is
 509      called automatically in that case.  And the Alliant fx2800 linker
 510      crashes on this reference.  So prevent the crash.  */
 511   __do_global_ctors_aux ();
 512 #endif
 513 }
 514
 515 asm (INIT_SECTION_ASM_OP);      /* cc1 doesn't know that we are switching! */
 516
 517 /* A routine to invoke all of the global constructors upon entry to the
 518    program.  We put this into the .init section (for systems that have
 519    such a thing) so that we can properly perform the construction of
 520    file-scope static-storage C++ objects within shared libraries.  */
 521
 522 static void __attribute__((used))
 523 __do_global_ctors_aux (void)    /* prologue goes in .init section */
 524 {
 525   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
 526   asm (TEXT_SECTION_ASM_OP);    /* don't put epilogue and body in .init */
 527   DO_GLOBAL_CTORS_BODY;
 528   atexit (__do_global_dtors);
 529 }
 530
 531 #endif /* OBJECT_FORMAT_ELF */
 532
 533 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 534
 535 extern void __do_global_dtors (void);
 536
 537 /* This case is used by the Irix 6 port, which supports named sections but
 538    not an SVR4-style .fini section.  __do_global_dtors can be non-static
 539    in this case because we protect it with -hidden_symbol.  */
 540
 541 void
 542 __do_global_dtors (void)
 543 {
 544   func_ptr *p, f;
 545   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
 546     f ();
 547
 548 #if USE_TM_CLONE_REGISTRY
 549   deregister_tm_clones ();
 550 #endif /* USE_TM_CLONE_REGISTRY */
 551
 552 #ifdef USE_EH_FRAME_REGISTRY
 553   if (__deregister_frame_info)
 554     __deregister_frame_info (__EH_FRAME_BEGIN__);
 555 #endif
 556 }
 557
 558 #if defined(USE_EH_FRAME_REGISTRY) \
 559     || defined(JCR_SECTION_NAME) \
 560     || defined(USE_TM_CLONE_REGISTRY)
 561 /* A helper function for __do_global_ctors, which is in crtend.o.  Here
 562    in crtbegin.o, we can reference a couple of symbols not visible there.
 563    Plus, since we're before libgcc.a, we have no problems referencing
 564    functions from there.  */
 565 void
 566 __do_global_ctors_1(void)
 567 {
 568 #ifdef USE_EH_FRAME_REGISTRY
 569   static struct object object;
 570   if (__register_frame_info)
 571     __register_frame_info (__EH_FRAME_BEGIN__, &object);
 572 #endif
 573
 574 #ifdef JCR_SECTION_NAME
 575   void **jcr_list
 576   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
 577   if (__builtin_expect (*jcr_list != NULL, 0))
 578     {
 579       void (*register_classes) (void *) = _Jv_RegisterClasses;
 580       __asm ("" : "+r" (register_classes));
 581       if (register_classes)
 582         register_classes (jcr_list);
 583     }
 584 #endif
 585
 586 #if USE_TM_CLONE_REGISTRY
 587   register_tm_clones ();
 588 #endif /* USE_TM_CLONE_REGISTRY */
 589 }
 590 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME || USE_TM_CLONE_REGISTRY */
 591
 592 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 593 #error "What are you doing with crtstuff.c, then?"
 594 #endif
 595
 596 #elif defined(CRT_END) /* ! CRT_BEGIN */
 597
 598 /* No need for .ctors/.dtors section if linker can place them in
 599    .init_array/.fini_array section.  */
 600 #ifndef USE_INITFINI_ARRAY
 601 /* Put a word containing zero at the end of each of our two lists of function
 602    addresses.  Note that the words defined here go into the .ctors and .dtors
 603    sections of the crtend.o file, and since that file is always linked in
 604    last, these words naturally end up at the very ends of the two lists
 605    contained in these two sections.  */
 606
 607 #ifdef CTOR_LIST_END
 608 CTOR_LIST_END;
 609 #elif defined(CTORS_SECTION_ASM_OP)
 610 /* Hack: force cc1 to switch to .data section early, so that assembling
 611    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
 612 static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
 613 asm (CTORS_SECTION_ASM_OP);
 614 STATIC func_ptr __CTOR_END__[1]
 615   __attribute__((aligned(sizeof(func_ptr))))
 616   = { (func_ptr) 0 };
 617 #else
 618 STATIC func_ptr __CTOR_END__[1]
 619   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
 620   = { (func_ptr) 0 };
 621 #endif
 622
 623 #ifdef DTOR_LIST_END
 624 DTOR_LIST_END;
 625 #elif defined(HIDDEN_DTOR_LIST_END)
 626 #ifdef DTORS_SECTION_ASM_OP
 627 asm (DTORS_SECTION_ASM_OP);
 628 #endif
 629 func_ptr __DTOR_END__[1]
 630   __attribute__ ((used,
 631 #ifndef DTORS_SECTION_ASM_OP
 632                   section(".dtors"),
 633 #endif
 634                   aligned(sizeof(func_ptr)), visibility ("hidden")))
 635   = { (func_ptr) 0 };
 636 #elif defined(DTORS_SECTION_ASM_OP)
 637 asm (DTORS_SECTION_ASM_OP);
 638 STATIC func_ptr __DTOR_END__[1]
 639   __attribute__ ((used, aligned(sizeof(func_ptr))))
 640   = { (func_ptr) 0 };
 641 #else
 642 STATIC func_ptr __DTOR_END__[1]
 643   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
 644   = { (func_ptr) 0 };
 645 #endif
 646 #endif /* USE_INITFINI_ARRAY */
 647
 648 #ifdef EH_FRAME_SECTION_NAME
 649 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
 650    this would be the 'length' field in a real FDE.  */
 651 # if __INT_MAX__ == 2147483647
 652 typedef int int32;
 653 # elif __LONG_MAX__ == 2147483647
 654 typedef long int32;
 655 # elif __SHRT_MAX__ == 2147483647
 656 typedef short int32;
 657 # else
 658 #  error "Missing a 4 byte integer"
 659 # endif
 660 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
 661      __attribute__ ((used, section(EH_FRAME_SECTION_NAME),
 662                      aligned(sizeof(int32))))
 663      = { 0 };
 664 #endif /* EH_FRAME_SECTION_NAME */
 665
 666 #ifdef JCR_SECTION_NAME
 667 /* Null terminate the .jcr section array.  */
 668 STATIC void *__JCR_END__[1]
 669    __attribute__ ((used, section(JCR_SECTION_NAME),
 670                    aligned(sizeof(void *))))
 671    = { 0 };
 672 #endif /* JCR_SECTION_NAME */
 673
 674 #if USE_TM_CLONE_REGISTRY
 675 # ifndef HAVE_GAS_HIDDEN
 676 static
 677 # endif
 678 func_ptr __TMC_END__[]
 679   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
 680 # ifdef HAVE_GAS_HIDDEN
 681   __attribute__((__visibility__ ("hidden"))) = { };
 682 # else
 683   = { 0, 0 };
 684 # endif
 685 #endif /* USE_TM_CLONE_REGISTRY */
 686
 687 #ifdef INIT_ARRAY_SECTION_ASM_OP
 688
 689 /* If we are using .init_array, there is nothing to do.  */
 690
 691 #elif defined(INIT_SECTION_ASM_OP)
 692
 693 #ifdef OBJECT_FORMAT_ELF
 694 static void __attribute__((used))
 695 __do_global_ctors_aux (void)
 696 {
 697   func_ptr *p;
 698   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 699     (*p) ();
 700 }
 701
 702 /* Stick a call to __do_global_ctors_aux into the .init section.  */
 703 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_ctors_aux)
 704 #else  /* OBJECT_FORMAT_ELF */
 705
 706 /* Stick the real initialization code, followed by a normal sort of
 707    function epilogue at the very end of the .init section for this
 708    entire root executable file or for this entire shared library file.
 709
 710    Note that we use some tricks here to get *just* the body and just
 711    a function epilogue (but no function prologue) into the .init
 712    section of the crtend.o file.  Specifically, we switch to the .text
 713    section, start to define a function, and then we switch to the .init
 714    section just before the body code.
 715
 716    Earlier on, we put the corresponding function prologue into the .init
 717    section of the crtbegin.o file (which will be linked in first).
 718
 719    Note that we want to invoke all constructors for C++ file-scope static-
 720    storage objects AFTER any other possible initialization actions which
 721    may be performed by the code in the .init section contributions made by
 722    other libraries, etc.  That's because those other initializations may
 723    include setup operations for very primitive things (e.g. initializing
 724    the state of the floating-point coprocessor, etc.) which should be done
 725    before we start to execute any of the user's code.  */
 726
 727 static void
 728 __do_global_ctors_aux (void)    /* prologue goes in .text section */
 729 {
 730   asm (INIT_SECTION_ASM_OP);
 731   DO_GLOBAL_CTORS_BODY;
 732   atexit (__do_global_dtors);
 733 }                               /* epilogue and body go in .init section */
 734
 735 FORCE_CODE_SECTION_ALIGN
 736 asm (TEXT_SECTION_ASM_OP);
 737
 738 #endif /* OBJECT_FORMAT_ELF */
 739
 740 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 741
 742 extern void __do_global_ctors (void);
 743
 744 /* This case is used by the Irix 6 port, which supports named sections but
 745    not an SVR4-style .init section.  __do_global_ctors can be non-static
 746    in this case because we protect it with -hidden_symbol.  */
 747 void
 748 __do_global_ctors (void)
 749 {
 750   func_ptr *p;
 751 #if defined(USE_EH_FRAME_REGISTRY) \
 752     || defined(JCR_SECTION_NAME) \
 753     || defined(USE_TM_CLONE_REGISTRY)
 754   __do_global_ctors_1();
 755 #endif
 756   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 757     (*p) ();
 758 }
 759
 760 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
 761 #error "What are you doing with crtstuff.c, then?"
 762 #endif
 763
 764 #else /* ! CRT_BEGIN && ! CRT_END */
 765 #error "One of CRT_BEGIN or CRT_END must be defined."
 766 #endif