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authorRoland McGrath <roland@hack.frob.com>2012-05-25 13:40:20 -0700
committerRoland McGrath <roland@hack.frob.com>2012-05-25 13:40:20 -0700
commit3a097cc7a18309c864186c1b864b90889d2a45e9 (patch)
tree90867caf9bc281dee470b566c7a3188ce86d20c1 /include
parent21708942c9b115a91dc03318a5f9e14328c5a71e (diff)
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Add --enable-systemtap configuration to define static probe points.
Diffstat (limited to 'include')
-rw-r--r--include/stap-probe.h80
1 files changed, 80 insertions, 0 deletions
diff --git a/include/stap-probe.h b/include/stap-probe.h
new file mode 100644
index 0000000..1051ad1
--- /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 */