stap-probe.h (2695B) - Raw
1 /* Macros for defining Systemtap <sys/sdt.h> static probe points. 2 Copyright (C) 2012-2025 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 #ifndef _STAP_PROBE_H 20 #define _STAP_PROBE_H 1 21 22 #ifdef USE_STAP_PROBE 23 24 # include <stap-probe-machine.h> 25 # include <sys/sdt.h> 26 27 /* Our code uses one macro LIBC_PROBE (name, n, arg1, ..., argn). 28 29 Without USE_STAP_PROBE, that does nothing but evaluates all 30 its arguments (to prevent bit rot, unlike e.g. assert). 31 32 Systemtap's header defines the macros STAP_PROBE (provider, name) and 33 STAP_PROBEn (provider, name, arg1, ..., argn). For "provider" we paste 34 in MODULE_NAME (libc, libpthread, etc.) automagically. 35 36 The format of the arg parameters is discussed here: 37 38 https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation 39 40 The precise details of how register names are specified is 41 architecture specific and can be found in the gdb and SystemTap 42 source code. */ 43 44 # define LIBC_PROBE(name, n, ...) \ 45 LIBC_PROBE_1 (MODULE_NAME, name, n, ## __VA_ARGS__) 46 47 # define LIBC_PROBE_1(lib, name, n, ...) \ 48 STAP_PROBE##n (lib, name, ## __VA_ARGS__) 49 50 # define STAP_PROBE0 STAP_PROBE 51 52 # define LIBC_PROBE_ASM(name, template) \ 53 STAP_PROBE_ASM (MODULE_NAME, name, template) 54 55 # define LIBC_PROBE_ASM_OPERANDS STAP_PROBE_ASM_OPERANDS 56 57 #else /* Not USE_STAP_PROBE. */ 58 59 # ifndef __ASSEMBLER__ 60 /* Evaluate all the arguments and verify that N matches their number. */ 61 # define LIBC_PROBE(name, n, ...) STAP_PROBE##n (__VA_ARGS__) 62 63 # define STAP_PROBE0() do {} while (0) 64 # define STAP_PROBE1(a1) do {} while (0) 65 # define STAP_PROBE2(a1, a2) do {} while (0) 66 # define STAP_PROBE3(a1, a2, a3) do {} while (0) 67 # define STAP_PROBE4(a1, a2, a3, a4) do {} while (0) 68 69 # else 70 # define LIBC_PROBE(name, n, ...) /* Nothing. */ 71 # endif 72 73 # define LIBC_PROBE_ASM(name, template) /* Nothing. */ 74 # define LIBC_PROBE_ASM_OPERANDS(n, ...) /* Nothing. */ 75 76 #endif /* USE_STAP_PROBE. */ 77 78 #endif /* stap-probe.h */