elf/soinit.c

   1 /* Initializer module for building the ELF shared C library.  This file and
   2    sofini.c do the work normally done by crtbeginS.o and crtendS.o, to wrap
   3    the `.ctors' and `.dtors' sections so the lists are terminated, and
   4    calling those lists of functions.  */
   5
   6 #include <libc-internal.h>
   7
   8 #ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
   9 # include <gccframe.h>
  10 #endif
  11
  12 static void (*const __CTOR_LIST__[1]) (void)
  13      __attribute__ ((section (".ctors")))
  14      = { (void (*) (void)) -1 };
  15 static void (*const __DTOR_LIST__[1]) (void)
  16      __attribute__ ((section (".dtors")))
  17      = { (void (*) (void)) -1 };
  18
  19 static inline void
  20 run_hooks (void (*const list[]) (void))
  21 {
  22   while (*++list)
  23     (**list) ();
  24 }
  25
  26 #ifdef HAVE_DWARF2_UNWIND_INFO
  27 static char __EH_FRAME_BEGIN__[]
  28      __attribute__ ((section (".eh_frame")))
  29      = { };
  30 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  31 extern void __register_frame_info (const void *, struct object *);
  32 extern void __deregister_frame_info (const void *);
  33 # else
  34 extern void __register_frame (const void *);
  35 extern void __deregister_frame (const void *);
  36 # endif
  37 #endif
  38
  39 /* This function will be called from _init in init-first.c.  */
  40 void
  41 __libc_global_ctors (void)
  42 {
  43   /* Call constructor functions.  */
  44   run_hooks (__CTOR_LIST__);
  45
  46 #ifdef HAVE_DWARF2_UNWIND_INFO
  47 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  48   {
  49     static struct object ob;
  50     __register_frame_info (__EH_FRAME_BEGIN__, &ob);
  51   }
  52 # else
  53   __register_frame (__EH_FRAME_BEGIN__);
  54 # endif
  55 #endif
  56 }
  57
  58
  59 /* This function becomes the DT_FINI termination function
  60    for the C library.  */
  61 void _fini (void) __attribute__ ((section (".fini"))); /* Just for kicks.  */
  62 void
  63 _fini (void)
  64 {
  65   /* Call destructor functions.  */
  66   run_hooks (__DTOR_LIST__);
  67 #ifdef HAVE_DWARF2_UNWIND_INFO
  68 # ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
  69   __deregister_frame_info (__EH_FRAME_BEGIN__);
  70 # else
  71   __deregister_frame (__EH_FRAME_BEGIN__);
  72 # endif
  73 #endif
  74 }