glibc/elf/soinit.c

/* Initializer module for building the ELF shared C library.  This file and
   sofini.c do the work normally done by crtbeginS.o and crtendS.o, to wrap
   the `.ctors' and `.dtors' sections so the lists are terminated, and
   calling those lists of functions.  */

static void (*const __CTOR_LIST__[1]) (void)
     __attribute__ ((section (".ctors")))
     = { (void (*) (void)) -1 };
static void (*const __DTOR_LIST__[1]) (void)
     __attribute__ ((section (".dtors")))
     = { (void (*) (void)) -1 };

static inline void
run_hooks (void (*const list[]) (void))
{
  while (*++list)
    (**list) ();
}

#ifdef HAVE_DWARF2_UNWIND_INFO
static char __EH_FRAME_BEGIN__[]
     __attribute__ ((section (".eh_frame")))
     = { };
# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
/* This must match what's in frame.h in gcc. How can one do that? */
struct object
{
  void *pc_begin;
  void *pc_end;
  void *fde_begin;
  void *fde_array;
  __SIZE_TYPE__ count;
  struct object *next;
};
extern void __register_frame_info (const void *, struct object *);
extern void __deregister_frame_info (const void *);
# else
extern void __register_frame (const void *);
extern void __deregister_frame (const void *);
# endif
#endif

/* We have to initialize the thread library at least if bit.  */
extern void __pthread_initialize_minimal (void) __attribute__ ((weak));

/* This function will be called from _init in init-first.c.  */
void
__libc_global_ctors (void)
{
  /* Call constructor functions.  */
  run_hooks (__CTOR_LIST__);

  /* Initialize the thread library at least a bit since the libgcc functions
     are using thread functions if these are available.  */
  if (__pthread_initialize_minimal)
    __pthread_initialize_minimal ();

#ifdef HAVE_DWARF2_UNWIND_INFO
# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  {
    static struct object ob;
    __register_frame_info (__EH_FRAME_BEGIN__, &ob);
  }
# else
  __register_frame (__EH_FRAME_BEGIN__);
# endif
#endif
}


/* This function becomes the DT_FINI termination function
   for the C library.  */
void _fini (void) __attribute__ ((section (".fini"))); /* Just for kicks.  */
void
_fini (void)
{
  /* Call destructor functions.  */
  run_hooks (__DTOR_LIST__);
#ifdef HAVE_DWARF2_UNWIND_INFO
# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  __deregister_frame_info (__EH_FRAME_BEGIN__);
# else
  __deregister_frame (__EH_FRAME_BEGIN__);
# endif
#endif
}