[PATCH v1 3/3] perf: Support perf -vv

[Jin Yao]

We keep having bug reports that when users build perf on their own,
but they don't install some needed libraries such as libelf,
libbfd/libibery.

The perf can build, but it is missing important functionality.

This patch provides a new option '-vv' which will print the
compiled-in status of libraries.

For example:

$ ./perf -vv
perf version 4.13.rc5.g9b7a81b
                 dwarf: [  on ]
    dwarf_getlocations: [  on ]
                 glibc: [  on ]
                  gtk2: [  on ]
              libaudit: [ off ]
                libbfd: [  on ]
                libelf: [  on ]
               libnuma: [  on ]
numa_num_possible_cpus: [  on ]
               libperl: [  on ]
             libpython: [  on ]
              libslang: [  on ]
             libcrypto: [  on ]
             libunwind: [  on ]
    libdw-dwarf-unwind: [  on ]
                  zlib: [  on ]
                  lzma: [  on ]
             get_cpuid: [  on ]
                   bpf: [  on ]

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/perf.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 1b3fc8e..300c83d 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -64,6 +64,7 @@ static struct cmd_struct commands[] = {
 	{ "top",	cmd_top,	0 },
 	{ "annotate",	cmd_annotate,	0 },
 	{ "version",	cmd_version,	0 },
+	{ "version2",	cmd_version2,	0 },
 	{ "script",	cmd_script,	0 },
 	{ "sched",	cmd_sched,	0 },
 #ifdef HAVE_LIBELF_SUPPORT
@@ -190,6 +191,11 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			break;
 		}
 
+		if (!strcmp(cmd, "-vv")) {
+			(*argv)[0] = "--version2";
+			break;
+		}
+
 		/*
 		 * Check remaining flags.
 		 */
-- 
2.7.4