perf tools: Stop using a global trace events description list

The pevent thing is per perf.data file, so I made it stop being static
and become a perf_session member, so tools processing perf.data files
use perf_session and _there_ we read the trace events description into
session->pevent and then change everywhere to stop using that single
global pevent variable and use the per session one.

Note that it _doesn't_ fall backs to trace__event_id, as we're not
interested at all in what is present in the
/sys/kernel/debug/tracing/events in the workstation doing the analysis,
just in what is in the perf.data file.

This patch also introduces perf_session__set_tracepoints_handlers that
is the perf perf.data/session way to associate handlers to tracepoint
events by resolving their IDs using the events descriptions stored in a
perf.data file. Make 'perf sched' use it.

Reported-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Tested-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linaro-dev@lists.linaro.org
Cc: patches@linaro.org
Link: http://lkml.kernel.org/r/20120625232016.GA28525@infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 6b305fb..f5baff1 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -14,6 +14,7 @@
 #include "sort.h"
 #include "util.h"
 #include "cpumap.h"
+#include "event-parse.h"
 
 static int perf_session__open(struct perf_session *self, bool force)
 {
@@ -1610,3 +1611,58 @@
 	perf_header__fprintf_info(session, fp, full);
 	fprintf(fp, "# ========\n#\n");
 }
+
+
+int __perf_session__set_tracepoints_handlers(struct perf_session *session,
+					     const struct perf_evsel_str_handler *assocs,
+					     size_t nr_assocs)
+{
+	struct perf_evlist *evlist = session->evlist;
+	struct event_format *format;
+	struct perf_evsel *evsel;
+	char *tracepoint, *name;
+	size_t i;
+	int err;
+
+	for (i = 0; i < nr_assocs; i++) {
+		err = -ENOMEM;
+		tracepoint = strdup(assocs[i].name);
+		if (tracepoint == NULL)
+			goto out;
+
+		err = -ENOENT;
+		name = strchr(tracepoint, ':');
+		if (name == NULL)
+			goto out_free;
+
+		*name++ = '\0';
+		format = pevent_find_event_by_name(session->pevent,
+						   tracepoint, name);
+		if (format == NULL) {
+			/*
+			 * Adding a handler for an event not in the session,
+			 * just ignore it.
+			 */
+			goto next;
+		}
+
+		evsel = perf_evlist__find_tracepoint_by_id(evlist, format->id);
+		if (evsel == NULL)
+			goto next;
+
+		err = -EEXIST;
+		if (evsel->handler.func != NULL)
+			goto out_free;
+		evsel->handler.func = assocs[i].handler;
+next:
+		free(tracepoint);
+	}
+
+	err = 0;
+out:
+	return err;
+
+out_free:
+	free(tracepoint);
+	goto out;
+}