perf tools: Add sort__has_comm variable

The sort__has_comm variable is to check whether the comm sort key is
given.  This is necessary to support thread filtering in the TUI hists
browser later.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457533253-21419-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/sort.c

@@ -27,6 +27,7 @@ int		sort__has_sym = 0;
 int		sort__has_dso = 0;
 int		sort__has_socket = 0;
 int		sort__has_thread = 0;
+int		sort__has_comm = 0;
 enum sort_mode	sort__mode = SORT_MODE__NORMAL;
 
 /*
@@ -2262,6 +2263,8 @@ static int sort_dimension__add(struct perf_hpp_list *list, const char *tok,
 			sort__has_socket = 1;
 		} else if (sd->entry == &sort_thread) {
 			sort__has_thread = 1;
+		} else if (sd->entry == &sort_comm) {
+			sort__has_comm = 1;
 		}
 
 		return __sort_dimension__add(sd, list, level);

tools/perf/util/sort.h

@@ -37,6 +37,7 @@ extern int sort__has_parent;
 extern int sort__has_sym;
 extern int sort__has_socket;
 extern int sort__has_thread;
+extern int sort__has_comm;
 extern enum sort_mode sort__mode;
 extern struct sort_entry sort_comm;
 extern struct sort_entry sort_dso;