perf probe: Uncomment and export synthesize_perf_probe_point()

Uncomment and export synthesize_perf_probe_point() which had once
introduced but has been disabled for a long time. This renews the code
and re-enable it.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160608092949.3116.21958.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/probe-event.c

@@ -67,7 +67,6 @@ int e_snprintf(char *str, size_t size, const char *format, ...)
 	return ret;
 }
 
-static char *synthesize_perf_probe_point(struct perf_probe_point *pp);
 static struct machine *host_machine;
 
 /* Initialize symbol maps and path of vmlinux/modules */
@@ -1716,7 +1715,7 @@ char *synthesize_perf_probe_arg(struct perf_probe_arg *pa)
 }
 
 /* Compose only probe point (not argument) */
-static char *synthesize_perf_probe_point(struct perf_probe_point *pp)
+char *synthesize_perf_probe_point(struct perf_probe_point *pp)
 {
 	struct strbuf buf;
 	char *tmp, *ret = NULL;
@@ -1755,30 +1754,36 @@ static char *synthesize_perf_probe_point(struct perf_probe_point *pp)
 	return ret;
 }
 
-#if 0
 char *synthesize_perf_probe_command(struct perf_probe_event *pev)
 {
-	char *buf;
-	int i, len, ret;
+	struct strbuf buf;
+	char *tmp, *ret = NULL;
+	int i;
 
-	buf = synthesize_perf_probe_point(&pev->point);
-	if (!buf)
+	if (strbuf_init(&buf, 64))
 		return NULL;
+	if (pev->event)
+		if (strbuf_addf(&buf, "%s:%s=", pev->group ?: PERFPROBE_GROUP,
+				pev->event) < 0)
+			goto out;
+
+	tmp = synthesize_perf_probe_point(&pev->point);
+	if (!tmp || strbuf_addstr(&buf, tmp) < 0)
+		goto out;
+	free(tmp);
 
-	len = strlen(buf);
 	for (i = 0; i < pev->nargs; i++) {
-		ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
-				 pev->args[i].name);
-		if (ret <= 0) {
-			free(buf);
-			return NULL;
-		}
-		len += ret;
+		tmp = synthesize_perf_probe_arg(pev->args + i);
+		if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0)
+			goto out;
+		free(tmp);
 	}
 
-	return buf;
+	ret = strbuf_detach(&buf, NULL);
+out:
+	strbuf_release(&buf);
+	return ret;
 }
-#endif
 
 static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
 					    struct strbuf *buf, int depth)

tools/perf/util/probe-event.h

@@ -121,6 +121,7 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev);
 char *synthesize_perf_probe_command(struct perf_probe_event *pev);
 char *synthesize_probe_trace_command(struct probe_trace_event *tev);
 char *synthesize_perf_probe_arg(struct perf_probe_arg *pa);
+char *synthesize_perf_probe_point(struct perf_probe_point *pp);
 
 int perf_probe_event__copy(struct perf_probe_event *dst,
 			   struct perf_probe_event *src);