perf trace: Warn the user when not available
When the audit-libs devel package is not found at build time we disable
the 'trace' command, as we are not able to map syscall numbers to
strings, but then the message the user is presented is cryptic:
[root@zoo linux]# trace ls
perf: 'ls' is not a perf-command. See 'perf --help'.
Fix it by presenting a more helpful message:
[root@zoo linux]# trace l
trace command not available: missing audit-libs devel package at build time.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uxeunqetd0sgxyibusapen9a@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 431798a..78f7b92 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -481,14 +481,18 @@
fprintf(stderr, "cannot handle %s internally", cmd);
goto out;
}
-#ifdef HAVE_LIBAUDIT_SUPPORT
if (!prefixcmp(cmd, "trace")) {
+#ifdef HAVE_LIBAUDIT_SUPPORT
set_buildid_dir();
setup_path();
argv[0] = "trace";
return cmd_trace(argc, argv, NULL);
- }
+#else
+ fprintf(stderr,
+ "trace command not available: missing audit-libs devel package at build time.\n");
+ goto out;
#endif
+ }
/* Look for flags.. */
argv++;
argc--;