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, 3 insertions, 3 deletions

diff --git a/tools/perf/util/parse-events-test.c b/tools/perf/util/parse-events-test.c
index bc8b65130ae0..d7244e553670 100644
--- a/tools/perf/util/parse-events-test.c
+++ b/tools/perf/util/parse-events-test.c
@@ -569,7 +569,7 @@ static int test__group2(struct perf_evlist *evlist)
 	return 0;
 }
 
-static int test__group3(struct perf_evlist *evlist __used)
+static int test__group3(struct perf_evlist *evlist __maybe_unused)
 {
 	struct perf_evsel *evsel, *leader;
 
@@ -648,7 +648,7 @@ static int test__group3(struct perf_evlist *evlist __used)
 	return 0;
 }
 
-static int test__group4(struct perf_evlist *evlist __used)
+static int test__group4(struct perf_evlist *evlist __maybe_unused)
 {
 	struct perf_evsel *evsel, *leader;
 
@@ -684,7 +684,7 @@ static int test__group4(struct perf_evlist *evlist __used)
 	return 0;
 }
 
-static int test__group5(struct perf_evlist *evlist __used)
+static int test__group5(struct perf_evlist *evlist __maybe_unused)
 {
 	struct perf_evsel *evsel, *leader;