perf hists: Introduce hist_entry__init function

Move the 'struct hist_entry' initialization code to a separate function.
It'll be useful and more clear for the following patches that introduce
allocation callbacks.

Releasing the hist_entry object in hist_entry__new function
(where it's allocated) rather than in hist_entry__init.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1467701765-26194-2-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.c

@@ -352,26 +352,16 @@ void hists__delete_entries(struct hists *hists)
  * histogram, sorted on item, collects periods
  */
 
-static struct hist_entry *hist_entry__new(struct hist_entry *template,
+static int hist_entry__init(struct hist_entry *he,
+			    struct hist_entry *template,
 			    bool sample_self)
 {
-	size_t callchain_size = 0;
-	struct hist_entry *he;
-
-	if (symbol_conf.use_callchain)
-		callchain_size = sizeof(struct callchain_root);
-
-	he = zalloc(sizeof(*he) + callchain_size);
-
-	if (he != NULL) {
 	*he = *template;
 
 	if (symbol_conf.cumulate_callchain) {
 		he->stat_acc = malloc(sizeof(he->stat));
-			if (he->stat_acc == NULL) {
-				free(he);
-				return NULL;
-			}
+		if (he->stat_acc == NULL)
+			return -ENOMEM;
 		memcpy(he->stat_acc, &he->stat, sizeof(he->stat));
 		if (!sample_self)
 			memset(&he->stat, 0, sizeof(he->stat));
@@ -389,8 +379,7 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
 		if (he->branch_info == NULL) {
 			map__zput(he->ms.map);
 			free(he->stat_acc);
-				free(he);
-				return NULL;
+			return -ENOMEM;
 		}
 
 		memcpy(he->branch_info, template->branch_info,
@@ -423,8 +412,7 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
 				map__put(he->mem_info->daddr.map);
 			}
 			free(he->stat_acc);
-				free(he);
-				return NULL;
+			return -ENOMEM;
 		}
 	}
 	INIT_LIST_HEAD(&he->pairs.node);
@@ -432,6 +420,25 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
 
 	if (!symbol_conf.report_hierarchy)
 		he->leaf = true;
+
+	return 0;
+}
+
+static struct hist_entry *hist_entry__new(struct hist_entry *template,
+					  bool sample_self)
+{
+	size_t callchain_size = 0;
+	struct hist_entry *he;
+	int err = 0;
+
+	if (symbol_conf.use_callchain)
+		callchain_size = sizeof(struct callchain_root);
+
+	he = zalloc(sizeof(*he) + callchain_size);
+	if (he) {
+		err = hist_entry__init(he, template, sample_self);
+		if (err)
+			zfree(&he);
 	}
 
 	return he;