perf evsel: Introduce perf_evsel__{str,int}val methods

Wrappers to the libtraceevent routines, so that we can further reduce
the surface contact perf builtins have with it.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
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-rtmgzptvrifzjxqwb9vs6g1b@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -10,6 +10,7 @@
 #include <byteswap.h>
 #include <linux/bitops.h>
 #include "asm/bug.h"
+#include "event-parse.h"
 #include "evsel.h"
 #include "evlist.h"
 #include "util.h"
@@ -1000,3 +1001,37 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type,
 
 	return 0;
 }
+
+char *perf_evsel__strval(struct perf_evsel *evsel, struct perf_sample *sample,
+			 const char *name)
+{
+	struct format_field *field = pevent_find_field(evsel->tp_format, name);
+	int offset;
+
+        if (!field)
+                return NULL;
+
+	offset = field->offset;
+
+	if (field->flags & FIELD_IS_DYNAMIC) {
+		offset = *(int *)(sample->raw_data + field->offset);
+		offset &= 0xffff;
+	}
+
+	return sample->raw_data + offset;
+}
+
+u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
+		       const char *name)
+{
+	struct format_field *field = pevent_find_field(evsel->tp_format, name);
+	u64 val;
+
+        if (!field)
+                return 0;
+
+	val = pevent_read_number(evsel->tp_format->pevent,
+				 sample->raw_data + field->offset, field->size);
+	return val;
+
+}

tools/perf/util/evsel.h

@@ -120,6 +120,13 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 		     struct thread_map *threads);
 void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads);
 
+struct perf_sample;
+
+char *perf_evsel__strval(struct perf_evsel *evsel, struct perf_sample *sample,
+			 const char *name);
+u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
+		       const char *name);
+
 #define perf_evsel__match(evsel, t, c)		\
 	(evsel->attr.type == PERF_TYPE_##t &&	\
 	 evsel->attr.config == PERF_COUNT_##c)