perf record: Make feature initialization generic

Loop over all features to enable it instead of explicitly enabling every
single feature. Reducing duplicate code and making it more robust to
later changes e.g. when adding more features.

Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1323966762-8574-3-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -386,7 +386,7 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
 {
 	struct stat st;
 	int flags;
-	int err, output;
+	int err, output, feat;
 	unsigned long waking = 0;
 	const bool forks = argc > 0;
 	struct machine *machine;
@@ -453,8 +453,14 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
 
 	rec->session = session;
 
-	if (!rec->no_buildid)
-		perf_header__set_feat(&session->header, HEADER_BUILD_ID);
+	for (feat = HEADER_FIRST_FEATURE; feat < HEADER_LAST_FEATURE; feat++)
+		perf_header__set_feat(&session->header, feat);
+
+	if (rec->no_buildid)
+		perf_header__clear_feat(&session->header, HEADER_BUILD_ID);
+
+	if (!have_tracepoints(&evsel_list->entries))
+		perf_header__clear_feat(&session->header, HEADER_TRACE_INFO);
 
 	if (!rec->file_new) {
 		err = perf_session__read_header(session, output);
@@ -462,22 +468,6 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
 			goto out_delete_session;
 	}
 
-	if (have_tracepoints(&evsel_list->entries))
-		perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
-
-	perf_header__set_feat(&session->header, HEADER_HOSTNAME);
-	perf_header__set_feat(&session->header, HEADER_OSRELEASE);
-	perf_header__set_feat(&session->header, HEADER_ARCH);
-	perf_header__set_feat(&session->header, HEADER_CPUDESC);
-	perf_header__set_feat(&session->header, HEADER_NRCPUS);
-	perf_header__set_feat(&session->header, HEADER_EVENT_DESC);
-	perf_header__set_feat(&session->header, HEADER_CMDLINE);
-	perf_header__set_feat(&session->header, HEADER_VERSION);
-	perf_header__set_feat(&session->header, HEADER_CPU_TOPOLOGY);
-	perf_header__set_feat(&session->header, HEADER_TOTAL_MEM);
-	perf_header__set_feat(&session->header, HEADER_NUMA_TOPOLOGY);
-	perf_header__set_feat(&session->header, HEADER_CPUID);
-
 	if (forks) {
 		err = perf_evlist__prepare_workload(evsel_list, opts, argv);
 		if (err < 0) {

tools/perf/util/header.h

@@ -11,6 +11,7 @@
 
 enum {
 	HEADER_RESERVED		= 0,	/* always cleared */
+	HEADER_FIRST_FEATURE	= 1,
 	HEADER_TRACE_INFO	= 1,
 	HEADER_BUILD_ID,