From 377d33ed8d03fbfd6c8655862de50d7fc213c0f4 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 13 Apr 2011 14:00:21 -0400 Subject: [PATCH] Tracepoints: add noargs support Add support for tracepoints receiving no argument as parameters. Copied from Linux kernel: commit 38516ab59fbc5b3bb278cf5e1fe2867c70cff32e Author: Steven Rostedt Date: Tue Apr 20 17:04:50 2010 -0400 Signed-off-by: Mathieu Desnoyers CC: Nils Carlson CC: Steven Rostedt --- include/ust/tracepoint.h | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h index b2e03cd..626f8af 100644 --- a/include/ust/tracepoint.h +++ b/include/ust/tracepoint.h @@ -175,10 +175,27 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, { } #endif /* CONFIG_TRACEPOINTS */ -#define DECLARE_TRACE(name, proto, args) \ - __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ - PARAMS(void *__data, proto), \ - PARAMS(__data, args)) +/* + * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype + * (void). "void" is a special value in a function prototype and can + * not be combined with other arguments. Since the DECLARE_TRACE() + * macro adds a data element at the beginning of the prototype, + * we need a way to differentiate "(void *data, proto)" from + * "(void *data, void)". The second prototype is invalid. + * + * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype + * and "void *__data" as the callback prototype. + * + * DECLARE_TRACE() passes "proto" as the tracepoint protoype and + * "void *__data, proto" as the callback prototype. + */ +#define DECLARE_TRACE_NOARGS(name) \ + __DECLARE_TRACE(name, void, , void *__data, __data) + +#define DECLARE_TRACE(name, proto, args) \ + __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ + PARAMS(void *__data, proto), \ + PARAMS(__data, args)) /* * Connect a probe to a tracepoint. -- 2.34.1