1  /* Machine-dependent definitions for profiling support.  Generic GCC 2 version.
       2     Copyright (C) 1996-2023 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     <https://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  }