1 /* Machine-dependent definitions for profiling support. Generic GCC 2 version. 2 Copyright (C) 1996-2022 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 } 48