perf tools: Add --debug optionto set debug variable

Adding --debug option as a way to setup debug variables.  Starting with
support for verbose, more will come.

It's possible to use it now with report command:
  $ perf --debug verbose   ...
  $ perf --debug verbose=2 ...

I'll need this support to add separated debug variable for ordered
events change in order to separate debug output out of standard verbose
stream.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140717105500.GG516@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 95c58fc15284..eed3fb2a3af0 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -13,11 +13,12 @@
 #include "util/quote.h"
 #include "util/run-command.h"
 #include "util/parse-events.h"
+#include "util/debug.h"
 #include <api/fs/debugfs.h>
 #include <pthread.h>
 
 const char perf_usage_string[] =
-	"perf [--version] [--help] COMMAND [ARGS]";
+	"perf [--version] [--debug variable[=VALUE]] [--help] COMMAND [ARGS]";
 
 const char perf_more_info_string[] =
 	"See 'perf help COMMAND' for more information on a specific command.";
@@ -212,6 +213,16 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 				printf("%s ", p->cmd);
 			}
 			exit(0);
+		} else if (!strcmp(cmd, "--debug")) {
+			if (*argc < 2) {
+				fprintf(stderr, "No variable specified for --debug.\n");
+				usage(perf_usage_string);
+			}
+			if (perf_debug_option((*argv)[1]))
+				usage(perf_usage_string);
+
+			(*argv)++;
+			(*argc)--;
 		} else {
 			fprintf(stderr, "Unknown option: %s\n", cmd);
 			usage(perf_usage_string);