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, 11 insertions, 10 deletions

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 031b349a3f84..407e855cccb8 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -13,7 +13,7 @@ static int hpp__header_overhead(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt);
 }
 
-static int hpp__width_overhead(struct perf_hpp *hpp __used)
+static int hpp__width_overhead(struct perf_hpp *hpp __maybe_unused)
 {
         return 8;
 }
@@ -62,7 +62,7 @@ static int hpp__header_overhead_sys(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt, "sys");
 }
 
-static int hpp__width_overhead_sys(struct perf_hpp *hpp __used)
+static int hpp__width_overhead_sys(struct perf_hpp *hpp __maybe_unused)
 {
         return 6;
 }
@@ -88,7 +88,7 @@ static int hpp__header_overhead_us(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt, "user");
 }
 
-static int hpp__width_overhead_us(struct perf_hpp *hpp __used)
+static int hpp__width_overhead_us(struct perf_hpp *hpp __maybe_unused)
 {
         return 6;
 }
@@ -112,7 +112,7 @@ static int hpp__header_overhead_guest_sys(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, "guest sys");
 }
 
-static int hpp__width_overhead_guest_sys(struct perf_hpp *hpp __used)
+static int hpp__width_overhead_guest_sys(struct perf_hpp *hpp __maybe_unused)
 {
         return 9;
 }
@@ -138,7 +138,7 @@ static int hpp__header_overhead_guest_us(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, "guest usr");
 }
 
-static int hpp__width_overhead_guest_us(struct perf_hpp *hpp __used)
+static int hpp__width_overhead_guest_us(struct perf_hpp *hpp __maybe_unused)
 {
         return 9;
 }
@@ -166,7 +166,7 @@ static int hpp__header_samples(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt, "Samples");
 }
 
-static int hpp__width_samples(struct perf_hpp *hpp __used)
+static int hpp__width_samples(struct perf_hpp *hpp __maybe_unused)
 {
         return 11;
 }
@@ -185,7 +185,7 @@ static int hpp__header_period(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt, "Period");
 }
 
-static int hpp__width_period(struct perf_hpp *hpp __used)
+static int hpp__width_period(struct perf_hpp *hpp __maybe_unused)
 {
         return 12;
 }
@@ -204,7 +204,7 @@ static int hpp__header_delta(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, fmt, "Delta");
 }
 
-static int hpp__width_delta(struct perf_hpp *hpp __used)
+static int hpp__width_delta(struct perf_hpp *hpp __maybe_unused)
 {
         return 7;
 }
@@ -238,12 +238,13 @@ static int hpp__header_displ(struct perf_hpp *hpp)
         return scnprintf(hpp->buf, hpp->size, "Displ.");
 }
 
-static int hpp__width_displ(struct perf_hpp *hpp __used)
+static int hpp__width_displ(struct perf_hpp *hpp __maybe_unused)
 {
         return 6;
 }
 
-static int hpp__entry_displ(struct perf_hpp *hpp, struct hist_entry *he __used)
+static int hpp__entry_displ(struct perf_hpp *hpp,
+                            struct hist_entry *he __maybe_unused)
 {
         const char *fmt = symbol_conf.field_sep ? "%s" : "%6.6s";
         char buf[32] = " ";