sysdeps/generic/machine-gmon.h

   1 /* Machine-dependent definitions for profiling support.  Generic GCC 2 version.
   2    Copyright (C) 1996-2015 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 /* GCC version 2 gives us a perfect magical function to get
  20    just the information we need:
  21      void *__builtin_return_address (unsigned int N)
  22    returns the return address of the frame N frames up.  */
  23
  24 /* Be warned that GCC cannot usefully compile __builtin_return_address(N)
  25    for N != 0 on all machines.  In this case, you may have to write
  26    your own version of _mcount().  */
  27
  28 #if __GNUC__ < 2
  29  #error "This file uses __builtin_return_address, a GCC 2 extension."
  30 #endif
  31
  32 #include <sysdep.h>
  33 /* The canonical name for the function is `_mcount' in both C and asm,
  34    but some old asm code might assume it's `mcount'.  */
  35 void _mcount (void);
  36 weak_alias (_mcount, mcount)
  37
  38 static void mcount_internal (u_long frompc, u_long selfpc);
  39
  40 #define _MCOUNT_DECL(frompc, selfpc) \
  41 static inline void mcount_internal (u_long frompc, u_long selfpc)
  42
  43 #define MCOUNT \
  44 void _mcount (void)                                                           \
  45 {                                                                             \
  46   mcount_internal ((u_long) RETURN_ADDRESS (1), (u_long) RETURN_ADDRESS (0)); \
  47 }