perf tools: Use __maybe_used for unused variables

perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 13 insertions, 11 deletions

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 64d8ba2..1eaa661 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -17,9 +17,9 @@
 static char		const *input_name = "-";
 static bool		inject_build_ids;
 
-static int perf_event__repipe_synth(struct perf_tool *tool __used,
+static int perf_event__repipe_synth(struct perf_tool *tool __maybe_unused,
 				    union perf_event *event,
-				    struct machine *machine __used)
+				    struct machine *machine __maybe_unused)
 {
 	uint32_t size;
 	void *buf = event;
@@ -40,7 +40,8 @@ static int perf_event__repipe_synth(struct perf_tool *tool __used,
 
 static int perf_event__repipe_op2_synth(struct perf_tool *tool,
 					union perf_event *event,
-					struct perf_session *session __used)
+					struct perf_session *session
+					__maybe_unused)
 {
 	return perf_event__repipe_synth(tool, event, NULL);
 }
@@ -52,13 +53,14 @@ static int perf_event__repipe_event_type_synth(struct perf_tool *tool,
 }
 
 static int perf_event__repipe_tracing_data_synth(union perf_event *event,
-						 struct perf_session *session __used)
+						 struct perf_session *session
+						 __maybe_unused)
 {
 	return perf_event__repipe_synth(NULL, event, NULL);
 }
 
 static int perf_event__repipe_attr(union perf_event *event,
-				   struct perf_evlist **pevlist __used)
+				   struct perf_evlist **pevlist __maybe_unused)
 {
 	int ret;
 	ret = perf_event__process_attr(event, pevlist);
@@ -70,7 +72,7 @@ static int perf_event__repipe_attr(union perf_event *event,
 
 static int perf_event__repipe(struct perf_tool *tool,
 			      union perf_event *event,
-			      struct perf_sample *sample __used,
+			      struct perf_sample *sample __maybe_unused,
 			      struct machine *machine)
 {
 	return perf_event__repipe_synth(tool, event, machine);
@@ -78,8 +80,8 @@ static int perf_event__repipe(struct perf_tool *tool,
 
 static int perf_event__repipe_sample(struct perf_tool *tool,
 				     union perf_event *event,
-			      struct perf_sample *sample __used,
-			      struct perf_evsel *evsel __used,
+			      struct perf_sample *sample __maybe_unused,
+			      struct perf_evsel *evsel __maybe_unused,
 			      struct machine *machine)
 {
 	return perf_event__repipe_synth(tool, event, machine);
@@ -163,7 +165,7 @@ static int dso__inject_build_id(struct dso *self, struct perf_tool *tool,
 static int perf_event__inject_buildid(struct perf_tool *tool,
 				      union perf_event *event,
 				      struct perf_sample *sample,
-				      struct perf_evsel *evsel __used,
+				      struct perf_evsel *evsel __maybe_unused,
 				      struct machine *machine)
 {
 	struct addr_location al;
@@ -224,7 +226,7 @@ struct perf_tool perf_inject = {
 
 extern volatile int session_done;
 
-static void sig_handler(int sig __attribute__((__unused__)))
+static void sig_handler(int sig __maybe_unused)
 {
 	session_done = 1;
 }
@@ -267,7 +269,7 @@ static const struct option options[] = {
 	OPT_END()
 };
 
-int cmd_inject(int argc, const char **argv, const char *prefix __used)
+int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	argc = parse_options(argc, argv, options, report_usage, 0);