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, 16 insertions, 12 deletions

diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index 6738ea128c90..259f8f2ea9c9 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -69,8 +69,9 @@ static int read_build_id(void *note_data, size_t note_len, void *bf,
 	return -1;
 }
 
-int filename__read_debuglink(const char *filename __used,
-			     char *debuglink __used, size_t size __used)
+int filename__read_debuglink(const char *filename __maybe_unused,
+			     char *debuglink __maybe_unused,
+			     size_t size __maybe_unused)
 {
 	return -1;
 }
@@ -241,7 +242,8 @@ out:
 	return ret;
 }
 
-int symsrc__init(struct symsrc *ss, struct dso *dso __used, const char *name,
+int symsrc__init(struct symsrc *ss, struct dso *dso __maybe_unused,
+		 const char *name,
 	         enum dso_binary_type type)
 {
 	int fd = open(name, O_RDONLY);
@@ -260,13 +262,13 @@ out_close:
 	return -1;
 }
 
-bool symsrc__possibly_runtime(struct symsrc *ss __used)
+bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
 {
 	/* Assume all sym sources could be a runtime image. */
 	return true;
 }
 
-bool symsrc__has_symtab(struct symsrc *ss __used)
+bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
 {
 	return false;
 }
@@ -277,17 +279,19 @@ void symsrc__destroy(struct symsrc *ss)
 	close(ss->fd);
 }
 
-int dso__synthesize_plt_symbols(struct dso *dso __used,
-				struct symsrc *ss __used,
-				struct map *map __used,
-				symbol_filter_t filter __used)
+int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
+				struct symsrc *ss __maybe_unused,
+				struct map *map __maybe_unused,
+				symbol_filter_t filter __maybe_unused)
 {
 	return 0;
 }
 
-int dso__load_sym(struct dso *dso, struct map *map __used, struct symsrc *ss,
-		  struct symsrc *runtime_ss __used,
-		  symbol_filter_t filter __used, int kmodule __used)
+int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
+		  struct symsrc *ss,
+		  struct symsrc *runtime_ss __maybe_unused,
+		  symbol_filter_t filter __maybe_unused,
+		  int kmodule __maybe_unused)
 {
 	unsigned char *build_id[BUILD_ID_SIZE];