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, 7 insertions, 6 deletions

diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 62a6e7a7365d..9b5b21e7b032 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -126,7 +126,7 @@ int symbol__alloc_hist(struct symbol *sym);
 void symbol__annotate_zero_histograms(struct symbol *sym);
 
 int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize);
-int symbol__annotate_init(struct map *map __used, struct symbol *sym);
+int symbol__annotate_init(struct map *map __maybe_unused, struct symbol *sym);
 int symbol__annotate_printf(struct symbol *sym, struct map *map, int evidx,
 			    bool full_paths, int min_pcnt, int max_lines,
 			    int context);
@@ -139,11 +139,12 @@ int symbol__tty_annotate(struct symbol *sym, struct map *map, int evidx,
 			 int max_lines);
 
 #ifdef NO_NEWT_SUPPORT
-static inline int symbol__tui_annotate(struct symbol *sym __used,
-				       struct map *map __used,
-				       int evidx __used,
-				       void(*timer)(void *arg) __used,
-				       void *arg __used, int delay_secs __used)
+static inline int symbol__tui_annotate(struct symbol *sym __maybe_unused,
+				       struct map *map __maybe_unused,
+				       int evidx __maybe_unused,
+				       void(*timer)(void *arg) __maybe_unused,
+				       void *arg __maybe_unused,
+				       int delay_secs __maybe_unused)
 {
 	return 0;
 }