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  1. /* Specialized bits of code needed to support construction and
  2.    destruction of file-scope objects in C++ code.
  3.    Copyright (C) 1991-2015 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. #ifdef USE_EH_FRAME_REGISTRY_ALWAYS
  135. # ifndef __LIBGCC_EH_FRAME_SECTION_NAME__
  136. #  error "Can't use explicit exception-frame-registration without __LIBGCC_EH_FRAME_SECTION_NAME__"
  137. # endif
  138. #endif
  139. #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) && (!defined(USE_PT_GNU_EH_FRAME) || defined(USE_EH_FRAME_REGISTRY_ALWAYS))
  140. # define USE_EH_FRAME_REGISTRY
  141. #endif
  142. #if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) \
  143.     && __LIBGCC_EH_TABLES_CAN_BE_READ_ONLY__
  144. # define EH_FRAME_SECTION_CONST const
  145. #else
  146. # define EH_FRAME_SECTION_CONST
  147. #endif
  148.  
  149. #if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
  150.     && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
  151. # define HIDDEN_DTOR_LIST_END
  152. #endif
  153.  
  154. #if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
  155. # define USE_TM_CLONE_REGISTRY 1
  156. #endif
  157.  
  158. /* We do not want to add the weak attribute to the declarations of these
  159.    routines in unwind-dw2-fde.h because that will cause the definition of
  160.    these symbols to be weak as well.
  161.  
  162.    This exposes a core issue, how to handle creating weak references vs
  163.    how to create weak definitions.  Either we have to have the definition
  164.    of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
  165.    have a second declaration if we want a function's references to be weak,
  166.    but not its definition.
  167.  
  168.    Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
  169.    one thinks about scaling to larger problems -- i.e., the condition under
  170.    which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
  171.    complicated.
  172.  
  173.    So, we take an approach similar to #pragma weak -- we have a second
  174.    declaration for functions that we want to have weak references.
  175.  
  176.    Neither way is particularly good.  */
  177.  
  178. /* References to __register_frame_info and __deregister_frame_info should
  179.    be weak in this file if at all possible.  */
  180. extern void __register_frame_info (const void *, struct object *)
  181.                                   TARGET_ATTRIBUTE_WEAK;
  182. extern void __register_frame_info_bases (const void *, struct object *,
  183.                                          void *, void *)
  184.                                   TARGET_ATTRIBUTE_WEAK;
  185. extern void *__deregister_frame_info (const void *)
  186.                                      TARGET_ATTRIBUTE_WEAK;
  187. extern void *__deregister_frame_info_bases (const void *)
  188.                                      TARGET_ATTRIBUTE_WEAK;
  189. extern void __do_global_ctors_1 (void);
  190.  
  191. /* Likewise for _Jv_RegisterClasses.  */
  192. extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
  193.  
  194. /* Likewise for transactional memory clone tables.  */
  195. extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
  196. extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
  197.  
  198. #ifdef OBJECT_FORMAT_ELF
  199.  
  200. /*  Declare a pointer to void function type.  */
  201. typedef void (*func_ptr) (void);
  202. #define STATIC static
  203.  
  204. #else  /* OBJECT_FORMAT_ELF */
  205.  
  206. #include "gbl-ctors.h"
  207.  
  208. #define STATIC
  209.  
  210. #endif /* OBJECT_FORMAT_ELF */
  211.  
  212. #ifdef CRT_BEGIN
  213.  
  214. /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
  215.    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
  216.    __DTOR_END__ } per root executable and also one set of these symbols
  217.    per shared library.  So in any given whole process image, we may have
  218.    multiple definitions of each of these symbols.  In order to prevent
  219.    these definitions from conflicting with one another, and in order to
  220.    ensure that the proper lists are used for the initialization/finalization
  221.    of each individual shared library (respectively), we give these symbols
  222.    only internal (i.e. `static') linkage, and we also make it a point to
  223.    refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
  224.    symbol in crtbegin.o, where they are defined.  */
  225.  
  226. /* No need for .ctors/.dtors section if linker can place them in
  227.    .init_array/.fini_array section.  */
  228. #ifndef USE_INITFINI_ARRAY
  229. /* The -1 is a flag to __do_global_[cd]tors indicating that this table
  230.    does not start with a count of elements.  */
  231. #ifdef CTOR_LIST_BEGIN
  232. CTOR_LIST_BEGIN;
  233. #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
  234. /* Hack: force cc1 to switch to .data section early, so that assembling
  235.    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
  236. static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
  237. asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
  238. STATIC func_ptr __CTOR_LIST__[1]
  239.   __attribute__ ((__used__, aligned(sizeof(func_ptr))))
  240.   = { (func_ptr) (-1) };
  241. #else
  242. STATIC func_ptr __CTOR_LIST__[1]
  243.   __attribute__ ((__used__, section(".ctors"), aligned(sizeof(func_ptr))))
  244.   = { (func_ptr) (-1) };
  245. #endif /* __CTOR_LIST__ alternatives */
  246.  
  247. #ifdef DTOR_LIST_BEGIN
  248. DTOR_LIST_BEGIN;
  249. #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
  250. asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
  251. STATIC func_ptr __DTOR_LIST__[1]
  252.   __attribute__ ((aligned(sizeof(func_ptr))))
  253.   = { (func_ptr) (-1) };
  254. #else
  255. STATIC func_ptr __DTOR_LIST__[1]
  256.   __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
  257.   = { (func_ptr) (-1) };
  258. #endif /* __DTOR_LIST__ alternatives */
  259. #endif /* USE_INITFINI_ARRAY */
  260.  
  261. #ifdef USE_EH_FRAME_REGISTRY
  262. /* Stick a label at the beginning of the frame unwind info so we can register
  263.    and deregister it with the exception handling library code.  */
  264. STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
  265.      __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4)))
  266.      = { };
  267. #endif /* USE_EH_FRAME_REGISTRY */
  268.  
  269. #ifdef __LIBGCC_JCR_SECTION_NAME__
  270. /* Stick a label at the beginning of the java class registration info
  271.    so we can register them properly.  */
  272. STATIC void *__JCR_LIST__[]
  273.   __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__),
  274.                   aligned(sizeof(void*))))
  275.   = { };
  276. #endif /* __LIBGCC_JCR_SECTION_NAME__ */
  277.  
  278. #if USE_TM_CLONE_REGISTRY
  279. STATIC func_ptr __TMC_LIST__[]
  280.   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void*))))
  281.   = { };
  282. # ifdef HAVE_GAS_HIDDEN
  283. extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
  284. # endif
  285.  
  286. static inline void
  287. deregister_tm_clones (void)
  288. {
  289.   void (*fn) (void *);
  290.  
  291. #ifdef HAVE_GAS_HIDDEN
  292.   if (__TMC_END__ - __TMC_LIST__ == 0)
  293.     return;
  294. #else
  295.   if (__TMC_LIST__[0] == NULL)
  296.     return;
  297. #endif
  298.  
  299.   fn = _ITM_deregisterTMCloneTable;
  300.   __asm ("" : "+r" (fn));
  301.   if (fn)
  302.     fn (__TMC_LIST__);
  303. }
  304.  
  305. static inline void
  306. register_tm_clones (void)
  307. {
  308.   void (*fn) (void *, size_t);
  309.   size_t size;
  310.  
  311. #ifdef HAVE_GAS_HIDDEN
  312.   size = (__TMC_END__ - __TMC_LIST__) / 2;
  313. #else
  314.   for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
  315.     continue;
  316. #endif
  317.   if (size == 0)
  318.     return;
  319.  
  320.   fn = _ITM_registerTMCloneTable;
  321.   __asm ("" : "+r" (fn));
  322.   if (fn)
  323.     fn (__TMC_LIST__, size);
  324. }
  325. #endif /* USE_TM_CLONE_REGISTRY */
  326.  
  327. #if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
  328.     || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
  329.  
  330. #ifdef OBJECT_FORMAT_ELF
  331.  
  332. /* Declare the __dso_handle variable.  It should have a unique value
  333.    in every shared-object; in a main program its value is zero.  The
  334.    object should in any case be protected.  This means the instance
  335.    in one DSO or the main program is not used in another object.  The
  336.    dynamic linker takes care of this.  */
  337.  
  338. #ifdef TARGET_LIBGCC_SDATA_SECTION
  339. extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
  340. #endif
  341. #ifdef HAVE_GAS_HIDDEN
  342. extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
  343. #endif
  344. #ifdef CRTSTUFFS_O
  345. void *__dso_handle = &__dso_handle;
  346. #else
  347. void *__dso_handle = 0;
  348. #endif
  349.  
  350. /* The __cxa_finalize function may not be available so we use only a
  351.    weak declaration.  */
  352. extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
  353.  
  354. /* Run all the global destructors on exit from the program.  */
  355.  
  356. /* Some systems place the number of pointers in the first word of the
  357.    table.  On SVR4 however, that word is -1.  In all cases, the table is
  358.    null-terminated.  On SVR4, we start from the beginning of the list and
  359.    invoke each per-compilation-unit destructor routine in order
  360.    until we find that null.
  361.  
  362.    Note that this function MUST be static.  There will be one of these
  363.    functions in each root executable and one in each shared library, but
  364.    although they all have the same code, each one is unique in that it
  365.    refers to one particular associated `__DTOR_LIST__' which belongs to the
  366.    same particular root executable or shared library file.
  367.  
  368.    On some systems, this routine is run more than once from the .fini,
  369.    when exit is called recursively, so we arrange to remember where in
  370.    the list we left off processing, and we resume at that point,
  371.    should we be re-invoked.  */
  372.  
  373. static void __attribute__((used))
  374. __do_global_dtors_aux (void)
  375. {
  376.   static _Bool completed;
  377.  
  378.   if (__builtin_expect (completed, 0))
  379.     return;
  380.  
  381. #ifdef CRTSTUFFS_O
  382.   if (__cxa_finalize)
  383.     __cxa_finalize (__dso_handle);
  384. #endif
  385.  
  386. #ifdef FINI_ARRAY_SECTION_ASM_OP
  387.   /* If we are using .fini_array then destructors will be run via that
  388.      mechanism.  */
  389. #elif defined(HIDDEN_DTOR_LIST_END)
  390.   {
  391.     /* Safer version that makes sure only .dtors function pointers are
  392.        called even if the static variable is maliciously changed.  */
  393.     extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
  394.     static size_t dtor_idx;
  395.     const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
  396.     func_ptr *dtor_list;
  397.  
  398.     __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__));
  399.     while (dtor_idx < max_idx)
  400.       dtor_list[++dtor_idx] ();
  401.   }
  402. #else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
  403.   {
  404.     static func_ptr *p = __DTOR_LIST__ + 1;
  405.     func_ptr f;
  406.  
  407.     while ((f = *p))
  408.       {
  409.         p++;
  410.         f ();
  411.       }
  412.   }
  413. #endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
  414.  
  415. #if USE_TM_CLONE_REGISTRY
  416.   deregister_tm_clones ();
  417. #endif /* USE_TM_CLONE_REGISTRY */
  418.  
  419. #ifdef USE_EH_FRAME_REGISTRY
  420. #ifdef CRT_GET_RFIB_DATA
  421.   /* If we used the new __register_frame_info_bases interface,
  422.      make sure that we deregister from the same place.  */
  423.   if (__deregister_frame_info_bases)
  424.     __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
  425. #else
  426.   if (__deregister_frame_info)
  427.     __deregister_frame_info (__EH_FRAME_BEGIN__);
  428. #endif
  429. #endif
  430.  
  431.   completed = 1;
  432. }
  433.  
  434. /* Stick a call to __do_global_dtors_aux into the .fini section.  */
  435. #ifdef FINI_SECTION_ASM_OP
  436. CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
  437. #elif defined (FINI_ARRAY_SECTION_ASM_OP)
  438. static func_ptr __do_global_dtors_aux_fini_array_entry[]
  439.   __attribute__ ((__used__, section(".fini_array"), aligned(sizeof(func_ptr))))
  440.   = { __do_global_dtors_aux };
  441. #else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
  442. static void __attribute__((used))
  443. __do_global_dtors_aux_1 (void)
  444. {
  445.   atexit (__do_global_dtors_aux);
  446. }
  447. CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
  448.                           __do_global_dtors_aux_1)
  449. #endif
  450.  
  451. #if defined(USE_EH_FRAME_REGISTRY) \
  452.     || defined(__LIBGCC_JCR_SECTION_NAME__) \
  453.     || defined(USE_TM_CLONE_REGISTRY)
  454. /* Stick a call to __register_frame_info into the .init section.  For some
  455.    reason calls with no arguments work more reliably in .init, so stick the
  456.    call in another function.  */
  457.  
  458. static void __attribute__((used))
  459. frame_dummy (void)
  460. {
  461. #ifdef USE_EH_FRAME_REGISTRY
  462.   static struct object object;
  463. #ifdef CRT_GET_RFIB_DATA
  464.   void *tbase, *dbase;
  465.   tbase = 0;
  466.   CRT_GET_RFIB_DATA (dbase);
  467.   if (__register_frame_info_bases)
  468.     __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
  469. #else
  470.   if (__register_frame_info)
  471.     __register_frame_info (__EH_FRAME_BEGIN__, &object);
  472. #endif /* CRT_GET_RFIB_DATA */
  473. #endif /* USE_EH_FRAME_REGISTRY */
  474.  
  475. #ifdef __LIBGCC_JCR_SECTION_NAME__
  476.   void **jcr_list;
  477.   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
  478.   if (__builtin_expect (*jcr_list != NULL, 0))
  479.     {
  480.       void (*register_classes) (void *) = _Jv_RegisterClasses;
  481.       __asm ("" : "+r" (register_classes));
  482.       if (register_classes)
  483.         register_classes (jcr_list);
  484.     }
  485. #endif /* __LIBGCC_JCR_SECTION_NAME__ */
  486.  
  487. #if USE_TM_CLONE_REGISTRY
  488.   register_tm_clones ();
  489. #endif /* USE_TM_CLONE_REGISTRY */
  490. }
  491.  
  492. #ifdef __LIBGCC_INIT_SECTION_ASM_OP__
  493. CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
  494. #else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
  495. static func_ptr __frame_dummy_init_array_entry[]
  496.   __attribute__ ((__used__, section(".init_array"), aligned(sizeof(func_ptr))))
  497.   = { frame_dummy };
  498. #endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
  499. #endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */
  500.  
  501. #else  /* OBJECT_FORMAT_ELF */
  502.  
  503. /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
  504.    and once in crtend.o).  It must be declared static to avoid a link
  505.    error.  Here, we define __do_global_ctors as an externally callable
  506.    function.  It is externally callable so that __main can invoke it when
  507.    INVOKE__main is defined.  This has the additional effect of forcing cc1
  508.    to switch to the .text section.  */
  509.  
  510. static void __do_global_ctors_aux (void);
  511. void
  512. __do_global_ctors (void)
  513. {
  514. #ifdef INVOKE__main
  515.   /* If __main won't actually call __do_global_ctors then it doesn't matter
  516.      what's inside the function.  The inside of __do_global_ctors_aux is
  517.      called automatically in that case.  And the Alliant fx2800 linker
  518.      crashes on this reference.  So prevent the crash.  */
  519.   __do_global_ctors_aux ();
  520. #endif
  521. }
  522.  
  523. asm (__LIBGCC_INIT_SECTION_ASM_OP__);   /* cc1 doesn't know that we are switching! */
  524.  
  525. /* A routine to invoke all of the global constructors upon entry to the
  526.    program.  We put this into the .init section (for systems that have
  527.    such a thing) so that we can properly perform the construction of
  528.    file-scope static-storage C++ objects within shared libraries.  */
  529.  
  530. static void __attribute__((used))
  531. __do_global_ctors_aux (void)    /* prologue goes in .init section */
  532. {
  533.   FORCE_CODE_SECTION_ALIGN      /* explicit align before switch to .text */
  534.   asm (__LIBGCC_TEXT_SECTION_ASM_OP__); /* don't put epilogue and body in .init */
  535.   DO_GLOBAL_CTORS_BODY;
  536.   atexit (__do_global_dtors);
  537. }
  538.  
  539. #endif /* OBJECT_FORMAT_ELF */
  540.  
  541. #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
  542.  
  543. extern void __do_global_dtors (void);
  544.  
  545. /* This case is used by the Irix 6 port, which supports named sections but
  546.    not an SVR4-style .fini section.  __do_global_dtors can be non-static
  547.    in this case because we protect it with -hidden_symbol.  */
  548.  
  549. void
  550. __do_global_dtors (void)
  551. {
  552.   func_ptr *p, f;
  553.   for (p = __DTOR_LIST__ + 1; (f = *p); p++)
  554.     f ();
  555.  
  556. #if USE_TM_CLONE_REGISTRY
  557.   deregister_tm_clones ();
  558. #endif /* USE_TM_CLONE_REGISTRY */
  559.  
  560. #ifdef USE_EH_FRAME_REGISTRY
  561.   if (__deregister_frame_info)
  562.     __deregister_frame_info (__EH_FRAME_BEGIN__);
  563. #endif
  564. }
  565.  
  566. #if defined(USE_EH_FRAME_REGISTRY) \
  567.     || defined(__LIBGCC_JCR_SECTION_NAME__) \
  568.     || defined(USE_TM_CLONE_REGISTRY)
  569. /* A helper function for __do_global_ctors, which is in crtend.o.  Here
  570.    in crtbegin.o, we can reference a couple of symbols not visible there.
  571.    Plus, since we're before libgcc.a, we have no problems referencing
  572.    functions from there.  */
  573. void
  574. __do_global_ctors_1(void)
  575. {
  576. #ifdef USE_EH_FRAME_REGISTRY
  577.   static struct object object;
  578.   if (__register_frame_info)
  579.     __register_frame_info (__EH_FRAME_BEGIN__, &object);
  580. #endif
  581.  
  582. #ifdef __LIBGCC_JCR_SECTION_NAME__
  583.   void **jcr_list;
  584.   __asm ("" : "=g" (jcr_list) : "0" (__JCR_LIST__));
  585.   if (__builtin_expect (*jcr_list != NULL, 0))
  586.     {
  587.       void (*register_classes) (void *) = _Jv_RegisterClasses;
  588.       __asm ("" : "+r" (register_classes));
  589.       if (register_classes)
  590.         register_classes (jcr_list);
  591.     }
  592. #endif
  593.  
  594. #if USE_TM_CLONE_REGISTRY
  595.   register_tm_clones ();
  596. #endif /* USE_TM_CLONE_REGISTRY */
  597. }
  598. #endif /* USE_EH_FRAME_REGISTRY || __LIBGCC_JCR_SECTION_NAME__ || USE_TM_CLONE_REGISTRY */
  599.  
  600. #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
  601. #error "What are you doing with crtstuff.c, then?"
  602. #endif
  603.  
  604. #elif defined(CRT_END) /* ! CRT_BEGIN */
  605.  
  606. /* No need for .ctors/.dtors section if linker can place them in
  607.    .init_array/.fini_array section.  */
  608. #ifndef USE_INITFINI_ARRAY
  609. /* Put a word containing zero at the end of each of our two lists of function
  610.    addresses.  Note that the words defined here go into the .ctors and .dtors
  611.    sections of the crtend.o file, and since that file is always linked in
  612.    last, these words naturally end up at the very ends of the two lists
  613.    contained in these two sections.  */
  614.  
  615. #ifdef CTOR_LIST_END
  616. CTOR_LIST_END;
  617. #elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
  618. /* Hack: force cc1 to switch to .data section early, so that assembling
  619.    __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
  620. static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
  621. asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
  622. STATIC func_ptr __CTOR_END__[1]
  623.   __attribute__((aligned(sizeof(func_ptr))))
  624.   = { (func_ptr) 0 };
  625. #else
  626. STATIC func_ptr __CTOR_END__[1]
  627.   __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
  628.   = { (func_ptr) 0 };
  629. #endif
  630.  
  631. #ifdef DTOR_LIST_END
  632. DTOR_LIST_END;
  633. #elif defined(HIDDEN_DTOR_LIST_END)
  634. #ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
  635. asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
  636. #endif
  637. func_ptr __DTOR_END__[1]
  638.   __attribute__ ((used,
  639. #ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
  640.                   section(".dtors"),
  641. #endif
  642.                   aligned(sizeof(func_ptr)), visibility ("hidden")))
  643.   = { (func_ptr) 0 };
  644. #elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
  645. asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
  646. STATIC func_ptr __DTOR_END__[1]
  647.   __attribute__ ((used, aligned(sizeof(func_ptr))))
  648.   = { (func_ptr) 0 };
  649. #else
  650. STATIC func_ptr __DTOR_END__[1]
  651.   __attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
  652.   = { (func_ptr) 0 };
  653. #endif
  654. #endif /* USE_INITFINI_ARRAY */
  655.  
  656. #ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
  657. /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
  658.    this would be the 'length' field in a real FDE.  */
  659. # if __INT_MAX__ == 2147483647
  660. typedef int int32;
  661. # elif __LONG_MAX__ == 2147483647
  662. typedef long int32;
  663. # elif __SHRT_MAX__ == 2147483647
  664. typedef short int32;
  665. # else
  666. #  error "Missing a 4 byte integer"
  667. # endif
  668. STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
  669.      __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
  670.                      aligned(sizeof(int32))))
  671.      = { 0 };
  672. #endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
  673.  
  674. #ifdef __LIBGCC_JCR_SECTION_NAME__
  675. /* Null terminate the .jcr section array.  */
  676. STATIC void *__JCR_END__[1]
  677.    __attribute__ ((used, section(__LIBGCC_JCR_SECTION_NAME__),
  678.                    aligned(sizeof(void *))))
  679.    = { 0 };
  680. #endif /* __LIBGCC_JCR_SECTION_NAME__ */
  681.  
  682. #if USE_TM_CLONE_REGISTRY
  683. # ifndef HAVE_GAS_HIDDEN
  684. static
  685. # endif
  686. func_ptr __TMC_END__[]
  687.   __attribute__((used, section(".tm_clone_table"), aligned(sizeof(void *))))
  688. # ifdef HAVE_GAS_HIDDEN
  689.   __attribute__((__visibility__ ("hidden"))) = { };
  690. # else
  691.   = { 0, 0 };
  692. # endif
  693. #endif /* USE_TM_CLONE_REGISTRY */
  694.  
  695. #ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
  696.  
  697. /* If we are using .init_array, there is nothing to do.  */
  698.  
  699. #elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
  700.  
  701. #ifdef OBJECT_FORMAT_ELF
  702. static void __attribute__((used))
  703. __do_global_ctors_aux (void)
  704. {
  705.   func_ptr *p;
  706.   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
  707.     (*p) ();
  708. }
  709.  
  710. /* Stick a call to __do_global_ctors_aux into the .init section.  */
  711. CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
  712. #else  /* OBJECT_FORMAT_ELF */
  713.  
  714. /* Stick the real initialization code, followed by a normal sort of
  715.    function epilogue at the very end of the .init section for this
  716.    entire root executable file or for this entire shared library file.
  717.  
  718.    Note that we use some tricks here to get *just* the body and just
  719.    a function epilogue (but no function prologue) into the .init
  720.    section of the crtend.o file.  Specifically, we switch to the .text
  721.    section, start to define a function, and then we switch to the .init
  722.    section just before the body code.
  723.  
  724.    Earlier on, we put the corresponding function prologue into the .init
  725.    section of the crtbegin.o file (which will be linked in first).
  726.  
  727.    Note that we want to invoke all constructors for C++ file-scope static-
  728.    storage objects AFTER any other possible initialization actions which
  729.    may be performed by the code in the .init section contributions made by
  730.    other libraries, etc.  That's because those other initializations may
  731.    include setup operations for very primitive things (e.g. initializing
  732.    the state of the floating-point coprocessor, etc.) which should be done
  733.    before we start to execute any of the user's code.  */
  734.  
  735. static void
  736. __do_global_ctors_aux (void)    /* prologue goes in .text section */
  737. {
  738.   asm (__LIBGCC_INIT_SECTION_ASM_OP__);
  739.   DO_GLOBAL_CTORS_BODY;
  740.   atexit (__do_global_dtors);
  741. }                               /* epilogue and body go in .init section */
  742.  
  743. FORCE_CODE_SECTION_ALIGN
  744. asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
  745.  
  746. #endif /* OBJECT_FORMAT_ELF */
  747.  
  748. #elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
  749.  
  750. extern void __do_global_ctors (void);
  751.  
  752. /* This case is used by the Irix 6 port, which supports named sections but
  753.    not an SVR4-style .init section.  __do_global_ctors can be non-static
  754.    in this case because we protect it with -hidden_symbol.  */
  755. void
  756. __do_global_ctors (void)
  757. {
  758.   func_ptr *p;
  759. #if defined(USE_EH_FRAME_REGISTRY) \
  760.     || defined(__LIBGCC_JCR_SECTION_NAME__) \
  761.     || defined(USE_TM_CLONE_REGISTRY)
  762.   __do_global_ctors_1();
  763. #endif
  764.   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
  765.     (*p) ();
  766. }
  767.  
  768. #else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
  769. #error "What are you doing with crtstuff.c, then?"
  770. #endif
  771.  
  772. #else /* ! CRT_BEGIN && ! CRT_END */
  773. #error "One of CRT_BEGIN or CRT_END must be defined."
  774. #endif
  775.