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, 18 insertions, 15 deletions

diff --git a/tools/perf/util/trace-event-scripting.c b/tools/perf/util/trace-event-scripting.c
index 302ff262494c..8715a1006d00 100644
--- a/tools/perf/util/trace-event-scripting.c
+++ b/tools/perf/util/trace-event-scripting.c
@@ -35,11 +35,11 @@ static int stop_script_unsupported(void)
         return 0;
 }
 
-static void process_event_unsupported(union perf_event *event __unused,
-                                      struct perf_sample *sample __unused,
-                                      struct perf_evsel *evsel __unused,
-                                      struct machine *machine __unused,
-                                      struct addr_location *al __unused)
+static void process_event_unsupported(union perf_event *event __maybe_unused,
+                                      struct perf_sample *sample __maybe_unused,
+                                      struct perf_evsel *evsel __maybe_unused,
+                                      struct machine *machine __maybe_unused,
+                                      struct addr_location *al __maybe_unused)
 {
 }
 
@@ -52,17 +52,19 @@ static void print_python_unsupported_msg(void)
                 "\n  etc.\n");
 }
 
-static int python_start_script_unsupported(const char *script __unused,
-                                           int argc __unused,
-                                           const char **argv __unused)
+static int python_start_script_unsupported(const char *script __maybe_unused,
+                                           int argc __maybe_unused,
+                                           const char **argv __maybe_unused)
 {
         print_python_unsupported_msg();
 
         return -1;
 }
 
-static int python_generate_script_unsupported(struct pevent *pevent __unused,
-                                              const char *outfile __unused)
+static int python_generate_script_unsupported(struct pevent *pevent
+                                              __maybe_unused,
+                                              const char *outfile
+                                              __maybe_unused)
 {
         print_python_unsupported_msg();
 
@@ -114,17 +116,18 @@ static void print_perl_unsupported_msg(void)
                 "\n  etc.\n");
 }
 
-static int perl_start_script_unsupported(const char *script __unused,
-                                         int argc __unused,
-                                         const char **argv __unused)
+static int perl_start_script_unsupported(const char *script __maybe_unused,
+                                         int argc __maybe_unused,
+                                         const char **argv __maybe_unused)
 {
         print_perl_unsupported_msg();
 
         return -1;
 }
 
-static int perl_generate_script_unsupported(struct pevent *pevent __unused,
-                                            const char *outfile __unused)
+static int perl_generate_script_unsupported(struct pevent *pevent
+                                            __maybe_unused,
+                                            const char *outfile __maybe_unused)
 {
         print_perl_unsupported_msg();