+/*
+ * Get exclusion names message for a single event.
+ *
+ * Returned pointer must be freed by caller. Returns NULL on error.
+ */
+static char *get_exclusion_names_msg(struct lttng_event *event)
+{
+ int ret;
+ int exclusion_count;
+ char *exclusion_msg = NULL;
+ char *at;
+ int count;
+ size_t i;
+ const char * const exclusion_fmt = " [exclusions: ";
+ const size_t exclusion_fmt_len = strlen(exclusion_fmt);
+
+ exclusion_count = lttng_event_get_exclusion_name_count(event);
+ if (exclusion_count < 0) {
+ goto end;
+ } else if (exclusion_count == 0) {
+ /*
+ * No exclusions: return copy of empty string so that
+ * it can be freed by caller.
+ */
+ exclusion_msg = strdup("");
+ goto end;
+ }
+
+ /*
+ * exclusion_msg's size is bounded by the exclusion_fmt string,
+ * a comma per entry, the entry count (fixed-size), a closing
+ * bracket, and a trailing \0.
+ */
+ exclusion_msg = malloc(exclusion_count +
+ exclusion_count * LTTNG_SYMBOL_NAME_LEN +
+ exclusion_fmt_len + 1);
+ if (!exclusion_msg) {
+ goto end;
+ }
+
+ at = strcpy(exclusion_msg, exclusion_fmt) + exclusion_fmt_len;
+ for (i = 0; i < exclusion_count; ++i) {
+ const char *name;
+
+ /* Append comma between exclusion names */
+ if (i > 0) {
+ *at = ',';
+ at++;
+ }
+
+ ret = lttng_event_get_exclusion_name(event, i, &name);
+ if (ret) {
+ /* Prints '?' on local error; should never happen */
+ *at = '?';
+ at++;
+ continue;
+ }
+
+ /* Append exclusion name */
+ count = sprintf(at, "%s", name);
+ at += count;
+ }
+
+ /* This also puts a final '\0' at the end of exclusion_msg */
+ strcpy(at, "]");
+
+end:
+ return exclusion_msg;
+}
+