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, 10 insertions, 9 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index f7f480503af4..8202f5ca0483 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -514,9 +514,9 @@ size_t perf_event__fprintf_comm(union perf_event *event, FILE *fp)
         return fprintf(fp, ": %s:%d\n", event->comm.comm, event->comm.tid);
 }
 
-int perf_event__process_comm(struct perf_tool *tool __used,
+int perf_event__process_comm(struct perf_tool *tool __maybe_unused,
                              union perf_event *event,
-                             struct perf_sample *sample __used,
+                             struct perf_sample *sample __maybe_unused,
                              struct machine *machine)
 {
         struct thread *thread = machine__findnew_thread(machine, event->comm.tid);
@@ -532,10 +532,10 @@ int perf_event__process_comm(struct perf_tool *tool __used,
         return 0;
 }
 
-int perf_event__process_lost(struct perf_tool *tool __used,
+int perf_event__process_lost(struct perf_tool *tool __maybe_unused,
                              union perf_event *event,
-                             struct perf_sample *sample __used,
-                             struct machine *machine __used)
+                             struct perf_sample *sample __maybe_unused,
+                             struct machine *machine __maybe_unused)
 {
         dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "\n",
                     event->lost.id, event->lost.lost);
@@ -555,7 +555,8 @@ static void perf_event__set_kernel_mmap_len(union perf_event *event,
                 maps[MAP__FUNCTION]->end = ~0ULL;
 }
 
-static int perf_event__process_kernel_mmap(struct perf_tool *tool __used,
+static int perf_event__process_kernel_mmap(struct perf_tool *tool
+                                           __maybe_unused,
                                            union perf_event *event,
                                            struct machine *machine)
 {
@@ -657,7 +658,7 @@ size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
 
 int perf_event__process_mmap(struct perf_tool *tool,
                              union perf_event *event,
-                             struct perf_sample *sample __used,
+                             struct perf_sample *sample __maybe_unused,
                              struct machine *machine)
 {
         struct thread *thread;
@@ -701,9 +702,9 @@ size_t perf_event__fprintf_task(union perf_event *event, FILE *fp)
                        event->fork.ppid, event->fork.ptid);
 }
 
-int perf_event__process_task(struct perf_tool *tool __used,
+int perf_event__process_task(struct perf_tool *tool __maybe_unused,
                              union perf_event *event,
-                             struct perf_sample *sample __used,
+                             struct perf_sample *sample __maybe_unused,
                               struct machine *machine)
 {
         struct thread *thread = machine__findnew_thread(machine, event->fork.tid);