perf tests: Run ctags/cscope make tests only with needed binaries

Running tags and cscope make tests only if the 'ctags' and 'cscope'
binaries are installed, so we don't have false alarm test failures.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@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/1374497014-2817-2-git-send-email-jolsa@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/make

 PERF := .
 MK   := Makefile
 
+has = $(shell which $1 2>/dev/null)
+
 # standard single make variable specified
 make_clean_all      := clean all
 make_python_perf_so := python/perf.so
@@ -50,14 +52,19 @@ run += make_no_backtrace
 run += make_no_libnuma
 run += make_no_libaudit
 run += make_no_libbionic
-run += make_tags
-run += make_cscope
 run += make_help
 run += make_doc
 run += make_perf_o
 run += make_util_map_o
 run += make_minimal
 
+ifneq ($(call has,ctags),)
+run += make_tags
+endif
+ifneq ($(call has,cscope),)
+run += make_cscope
+endif
+
 # $(run_O) contains same portion of $(run) tests with '_O' attached
 # to distinguish O=... tests
 run_O := $(addsuffix _O,$(run))