[PATCH v2] perf c2c: Use stdio interface if slang is not supported

[Leo Yan]

If slang lib is not installed on the system, perf c2c tool disables
TUI mode and roll back to use stdio mode;  but the flag 'c2c.use_stdio'
is missed to set true and thus it wrongly applies UI quirks in the
function ui_quirks().

This commit forces to use stdio interface if slang is not supported,
and it can avoid to apply the UI quirks and show the correct metric
header.

Before:

=================================================
      Shared Cache Line Distribution Pareto
=================================================
  -------------------------------------------------------------------------------
      0        0        0       99        0        0        0      0xaaaac17d6000
  -------------------------------------------------------------------------------
    0.00%    0.00%    6.06%    0.00%    0.00%    0.00%   0x20   N/A       0      0xaaaac17c25ac         0         0        43       375    18469         2  [.] 0x00000000000025ac  memstress         memstress[25ac]   0
    0.00%    0.00%   93.94%    0.00%    0.00%    0.00%   0x29   N/A       0      0xaaaac17c3e88         0         0       173       180      135         2  [.] 0x0000000000003e88  memstress         memstress[3e88]   0

After:

=================================================
      Shared Cache Line Distribution Pareto
=================================================
  -------------------------------------------------------------------------------
      0        0        0       99        0        0        0      0xaaaac17d6000
  -------------------------------------------------------------------------------
           0.00%    0.00%    6.06%    0.00%    0.00%    0.00%                0x20   N/A       0      0xaaaac17c25ac         0         0        43       375    18469         2  [.] 0x00000000000025ac  memstress         memstress[25ac]   0
           0.00%    0.00%   93.94%    0.00%    0.00%    0.00%                0x29   N/A       0      0xaaaac17c3e88         0         0       173       180      135         2  [.] 0x0000000000003e88  memstress         memstress[3e88]   0

Fixes: 5a1a99cd2e4e ("perf c2c report: Add main TUI browser")
Reported-by: Joe Mario <jmario@xxxxxxxxxx>
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---

Changes from v1:
* Added fixes tag;
* Added reported tag from Joe.

 tools/perf/builtin-c2c.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index c8230c48125f..80b525c065ed 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -2801,9 +2801,7 @@ static int perf_c2c__report(int argc, const char **argv)
 		   "the input file to process"),
 	OPT_INCR('N', "node-info", &c2c.node_info,
 		 "show extra node info in report (repeat for more info)"),
-#ifdef HAVE_SLANG_SUPPORT
 	OPT_BOOLEAN(0, "stdio", &c2c.use_stdio, "Use the stdio interface"),
-#endif
 	OPT_BOOLEAN(0, "stats", &c2c.stats_only,
 		    "Display only statistic tables (implies --stdio)"),
 	OPT_BOOLEAN(0, "full-symbols", &c2c.symbol_full,
@@ -2833,6 +2831,10 @@ static int perf_c2c__report(int argc, const char **argv)
 	if (argc)
 		usage_with_options(report_c2c_usage, options);
 
+#ifndef HAVE_SLANG_SUPPORT
+	c2c.use_stdio = true;
+#endif
+
 	if (c2c.stats_only)
 		c2c.use_stdio = true;
 
-- 
2.25.1