[PATCH 3/7] perf: add ability to change event according to sample (v2)

[Andrew Vagin <avagin@openvz.org>]

It's opposition of perf_session__parse_sample.

v2: fixed mistakes which David Arhen found

Signed-off-by: Andrew Vagin <avagin@openvz.org>
---
 tools/perf/util/event.h   |    2 +
 tools/perf/util/evsel.c   |   74 +++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/session.h |    9 +++++
 3 files changed, 85 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 357a85b..0493101 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -187,5 +187,7 @@ const char *perf_event__name(unsigned int id);
 int perf_event__parse_sample(const union perf_event *event, u64 type,
 			     int sample_size, bool sample_id_all,
 			     struct perf_sample *sample, bool swapped);
+int perf_event__change_sample(union perf_event *event, u64 type,
+			     const struct perf_sample *data, bool swapped);
 
 #endif /* __PERF_RECORD_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index e426264..d697568 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -494,3 +494,77 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
 
 	return 0;
 }
+
+int perf_event__change_sample(union perf_event *event, u64 type,
+			     const struct perf_sample *data, bool swapped)
+{
+	u64 *array;
+
+	/*
+	 * used for cross-endian analysis. See git commit 65014ab3
+	 * for why this goofiness is needed.
+	 */
+	union {
+		u64 val64;
+		u32 val32[2];
+	} u;
+
+	array = event->sample.array;
+
+	if (type & PERF_SAMPLE_IP) {
+		event->ip.ip = data->ip;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TID) {
+		u.val32[0] = data->pid;
+		u.val32[1] = data->tid;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val32[0] = bswap_32(u.val32[0]);
+			u.val32[1] = bswap_32(u.val32[1]);
+			u.val64 = bswap_64(u.val64);
+		}
+
+		*array = u.val64;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TIME) {
+		*array = data->time;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ADDR) {
+		*array = data->addr;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ID) {
+		*array = data->id;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_STREAM_ID) {
+		*array = data->stream_id;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_CPU) {
+		u.val32[0] = data->cpu;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val32[0] = bswap_32(u.val32[0]);
+			u.val64 = bswap_64(u.val64);
+		}
+		*array = u.val64;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_PERIOD) {
+		*array = data->period;
+		array++;
+	}
+
+	return 0;
+}
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 6e393c9..444f121 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -167,6 +167,15 @@ static inline int perf_session__parse_sample(struct perf_session *session,
 					session->header.needs_swap);
 }
 
+static inline int perf_session__change_sample(struct perf_session *session,
+					     union perf_event *event,
+					     const struct perf_sample *sample)
+{
+	return perf_event__change_sample(event, session->sample_type,
+					sample,
+					session->header.needs_swap);
+}
+
 struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
 					    unsigned int type);
 
-- 
1.7.1