sysdeps/unix/sysv/linux/init-first.h

   1 /* The job of this fragment it to find argc and friends for INIT.
   2    This is done in one of two ways: either in the stack context
   3    of program start, or having dlopen pass them in.  */
   4
   5 #define SYSDEP_CALL_INIT(NAME, INIT)                                          \
   6 void NAME (void *arg)                                                         \
   7 {                                                                             \
   8   int argc;                                                                   \
   9   char **argv, **envp;                                                        \
  10   /* The next variable is only here to work around a bug in gcc <= 2.7.2.1.   \
  11      If the address would be taken inside the expression the optimizer        \
  12      would try to be too smart and throws it away.  Grrr.  */                 \
  13   int *dummy_addr = &_dl_starting_up;                                         \
  14                                                                               \
  15   __libc_multiple_libcs = dummy_addr && !_dl_starting_up;                     \
  16                                                                               \
  17   if (!__libc_multiple_libcs)                                                 \
  18     {                                                                         \
  19       argc = (int) arg;                                                       \
  20       argv = (char **) &arg + 1;                                              \
  21       envp = &argv[argc+1];                                                   \
  22     }                                                                         \
  23   else                                                                        \
  24     {                                                                         \
  25       argc = (int) arg;                                                       \
  26       argv = ((char ***) &arg)[1];                                            \
  27       envp = ((char ***) &arg)[2];                                            \
  28     }                                                                         \
  29                                                                               \
  30   INIT (argc, argv, envp);                                                    \
  31 }