glibc/include/stap-probe.h
Siddhesh Poyarekar a10178bda1 Remove IN_LIB
Replace with IS_IN and IS_IN_LIB macros instead.  This change results
in a change in generated code, because it fixes a subtle bug.  The bug
was introduced when systemtap probes were added to lowlevellock.h,
which resulted in stap-probe.h being included in a number of places.
stap-probe.h always defines IN_LIB, which breaks a check in errno.h
and netdb.h since they rely on that macro to decide whether to
implement an internal version of a declaration or an external one.

The components that see a code change due to this are:

iconv_prog
libmemusage.so
libpcprofile.so
libSegFault.so
libutil.so.1
locale
localedef
nscd

All other built components (i.e. libc, libpthread, etc.) remain
unchanged by this on x86_64.

	* elf/Makefile (CPPFLAGS-.os): Remove IN_LIB.
	* elf/rtld-Rules (rtld-CPPFLAGS): Likewise.
	* extra-lib.mk (CPPFLAGS-$(lib)): Likewise.
	* include/libc-symbols.h (IS_IN_LIB): New macro.
	* include/errno.h: Use IS_IN_LIB instead of IN_LIB.
	* include/netdb.h: Likewise.
	* include/stap-probe.h: Remove all uses of IN_LIB.
2014-11-24 11:41:42 +05:30

78 lines
2.5 KiB
C

/* Macros for defining Systemtap <sys/sdt.h> static probe points.
Copyright (C) 2012-2014 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 MODULE_NAME (libc, libpthread, etc.) automagically.
The format of the arg parameters is discussed here:
https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation
The precise details of how register names are specified is
architecture specific and can be found in the gdb and SystemTap
source code. */
# define LIBC_PROBE(name, n, ...) \
LIBC_PROBE_1 (MODULE_NAME, 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 (MODULE_NAME, 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, ...) STAP_PROBE##n (__VA_ARGS__)
#define STAP_PROBE0()
#define STAP_PROBE1(a1)
#define STAP_PROBE2(a1, a2)
#define STAP_PROBE3(a1, a2, a3)
#define STAP_PROBE4(a1, a2, a3, a4)
# 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 */