perf list: Add debug support for outputing alias string

For debugging and testing it is useful to see the converted alias
string. Add support to perf stat/record and perf list to print the alias
conversion. The text string is saved in the alias structure.  For perf
stat/record it is folded into the normal -v. For perf list -v was taken,
so we use --debug.

Before:

% perf list
...
cache:
  l1d.replacement
       [L1D data line replacements]
  l1d_pend_miss.fb_full
       [Cycles a demand request was blocked due to Fill Buffers inavailability]

After

% perf list --debug
...
cache:
  l1d.replacement
       [L1D data line replacements]
        cpu/umask=0x1,period=2000003,event=0x51/
  l1d_pend_miss.fb_full
       [Cycles a demand request was blocked due to Fill Buffers inavailability]
        cpu/umask=0x2,period=2000003,cmask=1,event=0x48/

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170128020345.19007-6-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
index ba9322f..3b9d98b 100644
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -14,6 +14,7 @@
 #include "util/parse-events.h"
 #include "util/cache.h"
 #include "util/pmu.h"
+#include "util/debug.h"
 #include <subcmd/parse-options.h>
 
 static bool desc_flag = true;
@@ -29,6 +30,8 @@
 			    "Print extra event descriptions. --no-desc to not print."),
 		OPT_BOOLEAN('v', "long-desc", &long_desc_flag,
 			    "Print longer event descriptions."),
+		OPT_INCR(0, "debug", &verbose,
+			     "Enable debugging output"),
 		OPT_END()
 	};
 	const char * const list_usage[] = {