/* Macros for defining Systemtap <sys/sdt.h> static probe points. Copyright (C) 2012-2013 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #ifndef _STAP_PROBE_H #define _STAP_PROBE_H 1 #ifdef USE_STAP_PROBE # include <sys/sdt.h> /* Our code uses one macro LIBC_PROBE (name, n, arg1, ..., argn). Without USE_STAP_PROBE, that does nothing but evaluates all its arguments (to prevent bit rot, unlike e.g. assert). Systemtap's header defines the macros STAP_PROBE (provider, name) and STAP_PROBEn (provider, name, arg1, ..., argn). For "provider" we paste in the IN_LIB name (libc, libpthread, etc.) automagically. */ # ifndef NOT_IN_libc # define IN_LIB libc # elif !defined IN_LIB /* This is intentionally defined with extra unquoted commas in it so that macro substitution will bomb out when it is used. We don't just use #error here, so that this header can be included by other headers that use LIBC_PROBE inside their own macros. We only want such headers to fail to compile if those macros are actually used in a context where IN_LIB has not been defined. */ # define IN_LIB ,,,missing -DIN_LIB=... -- not extra-lib.mk?,,, # endif # define LIBC_PROBE(name, n, ...) \ LIBC_PROBE_1 (IN_LIB, name, n, ## __VA_ARGS__) # define LIBC_PROBE_1(lib, name, n, ...) \ STAP_PROBE##n (lib, name, ## __VA_ARGS__) # define STAP_PROBE0 STAP_PROBE # define LIBC_PROBE_ASM(name, template) \ STAP_PROBE_ASM (IN_LIB, name, template) # define LIBC_PROBE_ASM_OPERANDS STAP_PROBE_ASM_OPERANDS #else /* Not USE_STAP_PROBE. */ # ifndef __ASSEMBLER__ /* Evaluate all the arguments and verify that N matches their number. */ # define LIBC_PROBE(name, n, ...) \ do { \ _Bool __libc_probe_args[] = { 0, ## __VA_ARGS__ }; \ _Bool __libc_probe_verify_n[(sizeof __libc_probe_args / sizeof (_Bool)) \ == n + 1 ? 1 : -1]; \ (void) __libc_probe_verify_n; \ } while (0) # else # define LIBC_PROBE(name, n, ...) /* Nothing. */ # endif # define LIBC_PROBE_ASM(name, template) /* Nothing. */ # define LIBC_PROBE_ASM_OPERANDS(n, ...) /* Nothing. */ #endif /* USE_STAP_PROBE. */ #endif /* stap-probe.h */