perf evlist: Introduce add_newtp method

To reduce the boilerplate of creating and adding a new tracepoint to an
evlist.

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-4z90i79gnmsza2czv2dhdrb7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -200,24 +200,12 @@ static int trace__run(struct trace *trace)
 		goto out;
 	}
 
-	evsel = perf_evsel__newtp("raw_syscalls", "sys_enter", 0);
-	if (evsel == NULL) {
-		printf("Couldn't read the raw_syscalls:sys_enter tracepoint information!\n");
+	if (perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_enter", trace__sys_enter) ||
+	    perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit)) {
+		printf("Couldn't read the raw_syscalls tracepoints information!\n");
 		goto out_delete_evlist;
 	}
 
-	evsel->handler.func = trace__sys_enter;
-	perf_evlist__add(evlist, evsel);
-
-	evsel = perf_evsel__newtp("raw_syscalls", "sys_exit", 1);
-	if (evsel == NULL) {
-		printf("Couldn't read the raw_syscalls:sys_exit tracepoint information!\n");
-		goto out_delete_evlist;
-	}
-
-	evsel->handler.func = trace__sys_exit;
-	perf_evlist__add(evlist, evsel);
-
 	err = perf_evlist__create_maps(evlist, &trace->opts.target);
 	if (err < 0) {
 		printf("Problems parsing the target to trace, check your options!\n");

tools/perf/util/evlist.c

@@ -285,6 +285,20 @@ int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
 	return err;
 }
 
+int perf_evlist__add_newtp(struct perf_evlist *evlist,
+			   const char *sys, const char *name, void *handler)
+{
+	struct perf_evsel *evsel;
+
+	evsel = perf_evsel__newtp(sys, name, evlist->nr_entries);
+	if (evsel == NULL)
+		return -1;
+
+	evsel->handler.func = handler;
+	perf_evlist__add(evlist, evsel);
+	return 0;
+}
+
 void perf_evlist__disable(struct perf_evlist *evlist)
 {
 	int cpu, thread;

tools/perf/util/evlist.h

@@ -72,6 +72,9 @@ int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
 #define perf_evlist__set_tracepoints_handlers_array(evlist, array) \
 	perf_evlist__set_tracepoints_handlers(evlist, array, ARRAY_SIZE(array))
 
+int perf_evlist__add_newtp(struct perf_evlist *evlist,
+			   const char *sys, const char *name, void *handler);
+
 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter);
 
 struct perf_evsel *