lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Macros for defining Systemtap <sys/sdt.h> static probe points. |
| 2 | Copyright (C) 2012-2015 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 | #ifndef _STAP_PROBE_H |
| 20 | #define _STAP_PROBE_H 1 |
| 21 | |
| 22 | #ifdef USE_STAP_PROBE |
| 23 | |
| 24 | # include <sys/sdt.h> |
| 25 | |
| 26 | /* Our code uses one macro LIBC_PROBE (name, n, arg1, ..., argn). |
| 27 | |
| 28 | Without USE_STAP_PROBE, that does nothing but evaluates all |
| 29 | its arguments (to prevent bit rot, unlike e.g. assert). |
| 30 | |
| 31 | Systemtap's header defines the macros STAP_PROBE (provider, name) and |
| 32 | STAP_PROBEn (provider, name, arg1, ..., argn). For "provider" we paste |
| 33 | in MODULE_NAME (libc, libpthread, etc.) automagically. |
| 34 | |
| 35 | The format of the arg parameters is discussed here: |
| 36 | |
| 37 | https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation |
| 38 | |
| 39 | The precise details of how register names are specified is |
| 40 | architecture specific and can be found in the gdb and SystemTap |
| 41 | source code. */ |
| 42 | |
| 43 | # define LIBC_PROBE(name, n, ...) \ |
| 44 | LIBC_PROBE_1 (MODULE_NAME, name, n, ## __VA_ARGS__) |
| 45 | |
| 46 | # define LIBC_PROBE_1(lib, name, n, ...) \ |
| 47 | STAP_PROBE##n (lib, name, ## __VA_ARGS__) |
| 48 | |
| 49 | # define STAP_PROBE0 STAP_PROBE |
| 50 | |
| 51 | # define LIBC_PROBE_ASM(name, template) \ |
| 52 | STAP_PROBE_ASM (MODULE_NAME, name, template) |
| 53 | |
| 54 | # define LIBC_PROBE_ASM_OPERANDS STAP_PROBE_ASM_OPERANDS |
| 55 | |
| 56 | #else /* Not USE_STAP_PROBE. */ |
| 57 | |
| 58 | # ifndef __ASSEMBLER__ |
| 59 | /* Evaluate all the arguments and verify that N matches their number. */ |
| 60 | #define LIBC_PROBE(name, n, ...) STAP_PROBE##n (__VA_ARGS__) |
| 61 | |
| 62 | #define STAP_PROBE0() |
| 63 | #define STAP_PROBE1(a1) |
| 64 | #define STAP_PROBE2(a1, a2) |
| 65 | #define STAP_PROBE3(a1, a2, a3) |
| 66 | #define STAP_PROBE4(a1, a2, a3, a4) |
| 67 | |
| 68 | # else |
| 69 | # define LIBC_PROBE(name, n, ...) /* Nothing. */ |
| 70 | # endif |
| 71 | |
| 72 | # define LIBC_PROBE_ASM(name, template) /* Nothing. */ |
| 73 | # define LIBC_PROBE_ASM_OPERANDS(n, ...) /* Nothing. */ |
| 74 | |
| 75 | #endif /* USE_STAP_PROBE. */ |
| 76 | |
| 77 | #endif /* stap-probe.h */ |