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