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Diffstat (limited to 'include/stap-probe.h')
| -rw-r--r-- | include/stap-probe.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/include/stap-probe.h b/include/stap-probe.h new file mode 100644 index 0000000000..1051ad1980 --- /dev/null +++ b/include/stap-probe.h @@ -0,0 +1,80 @@ +/* Macros for defining Systemtap <sys/sdt.h> static probe points. + Copyright (C) 2012 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 */ |