set: add new helper set_make() which is like set_new() + multiple set_put() in vararg

src/basic/meson.build

@@ -145,6 +145,7 @@ basic_sources_plain = files('''
         securebits.h
         selinux-util.c
         selinux-util.h
+        set.c
         set.h
         sigbus.c
         sigbus.h

src/basic/set.c

@@ -0,0 +1,61 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2017 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "set.h"
+
+int set_make(Set **ret, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS, void *add, ...) {
+        _cleanup_set_free_ Set *s = NULL;
+        int r;
+
+        assert(ret);
+
+        s = set_new(hash_ops HASHMAP_DEBUG_PASS_ARGS);
+        if (!s)
+                return -ENOMEM;
+
+        if (add) {
+                va_list ap;
+
+                r = set_put(s, add);
+                if (r < 0)
+                        return r;
+
+                va_start(ap, add);
+
+                for(;;) {
+                        void *arg = va_arg(ap, void*);
+
+                        if (!arg)
+                                break;
+
+                        r = set_put(s, arg);
+                        if (r < 0) {
+                                va_end(ap);
+                                return r;
+                        }
+                }
+
+                va_end(ap);
+        }
+
+        *ret = s;
+        s = NULL;
+
+        return 0;
+}

src/basic/set.h

@@ -136,3 +136,5 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(Set*, set_free_free);
 
 #define _cleanup_set_free_ _cleanup_(set_freep)
 #define _cleanup_set_free_free_ _cleanup_(set_free_freep)
+
+int set_make(Set **ret, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS, void *add, ...);