perf tool: Add hpp interface to enable/disable hpp column

Adding perf_hpp__column_enable function to enable/disable hists column
and removing diff command specific stuff 'need_pair and
show_displacement' from hpp code.

The diff command now enables/disables columns separately according to
the user arguments. This will be helpful in future patches where more
columns are added into diff output.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1349354994-17853-6-git-send-email-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 413c65a1b..a0b531c 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -256,6 +256,21 @@
 	OPT_END()
 };
 
+static void ui_init(void)
+{
+	perf_hpp__init();
+
+	/* No overhead column. */
+	perf_hpp__column_enable(PERF_HPP__OVERHEAD, false);
+
+	/* Display baseline/delta/displacement columns. */
+	perf_hpp__column_enable(PERF_HPP__BASELINE, true);
+	perf_hpp__column_enable(PERF_HPP__DELTA, true);
+
+	if (show_displacement)
+		perf_hpp__column_enable(PERF_HPP__DISPL, true);
+}
+
 int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	sort_order = diff__default_sort_order;
@@ -278,7 +293,8 @@
 	if (symbol__init() < 0)
 		return -1;
 
-	perf_hpp__init(true, show_displacement);
+	ui_init();
+
 	setup_sorting(diff_usage, options);
 	setup_pager();