gmon/bb_init_func.c

   1 /* Copyright (C) 1996-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by David Mosberger (davidm@cs.arizona.edu).
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* __bb_init_func is invoked at the beginning of each function, before
  20    any registers have been saved.  This generic routine should work
  21    provided that calling this function doesn't mangle the arguments
  22    passed to the function being called.  If that's not the case, a
  23    system specific routine must be provided.  */
  24
  25 #include <sys/types.h>
  26 #include <sys/gmon.h>
  27
  28 #include <stdlib.h>
  29
  30 void
  31 __bb_init_func (struct __bb *bb)
  32 {
  33   struct gmonparam *p = &_gmonparam;
  34
  35   if (bb->zero_word != 0)
  36     {
  37       return;   /* handle common case quickly */
  38     }
  39
  40   /* insert this basic-block into basic-block list: */
  41   bb->zero_word = 1;
  42   bb->next = __bb_head;
  43   __bb_head = bb;
  44
  45   if (bb->next == 0 && p->state != GMON_PROF_ON)
  46     {
  47       /* we didn't register _mcleanup yet and pc profiling doesn't seem
  48          to be active, so let's register it now: */
  49       extern void *__dso_handle __attribute__ ((__weak__));
  50       __cxa_atexit ((void (*) (void *)) _mcleanup, NULL,
  51                     &__dso_handle ? __dso_handle : NULL);
  52     }
  53 }