[PATCH v3 4/5] 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' for perf which will
print the compiled-in status of libraries.

The 'perf -vv' is mapped to 'perf version --build-options'.

For example:

$ ./perf -vv

perf version 4.13.rc5.g4c1df1
                 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  ]

v3:
---
One bug is found in v2. It didn't process the option like '-vabc'
correctly. Fix this bug.

v2:
---
Use a global variable version_verbose to record the number of 'v'.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/perf.c | 6 ++++++
 tools/perf/perf.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 1b3fc8e..1659029 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -190,6 +190,12 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			break;
 		}
 
+		if (!strcmp(cmd, "-vv")) {
+			(*argv)[0] = "version";
+			version_verbose = 1;
+			break;
+		}
+
 		/*
 		 * Check remaining flags.
 		 */
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 8fec1ab..a1a9795 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -84,6 +84,7 @@ struct record_opts {
 struct option;
 extern const char * const *record_usage;
 extern struct option *record_options;
+extern int version_verbose;
 
 int record__parse_freq(const struct option *opt, const char *str, int unset);
 #endif
-- 
2.7.4