core: Add macros for local allocation

This is GCC-specific, but it makes the code significantly
cleaner.

src/libotutil/ot-local-alloc.c

@@ -0,0 +1,67 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2012 Colin Walters <walters@verbum.org>
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Colin Walters <walters@verbum.org>
+ */
+
+#include "config.h"
+
+#include "otutil.h"
+
+void
+ot_local_free (void *loc)
+{
+  void **location = loc;
+  if (location)
+    g_free (*location);
+}
+
+#define _ot_local_free(type, function) do {           \
+    void **location = loc;                            \
+    if (location)                                     \
+      {                                               \
+        type *value = *location;                      \
+        if (value)                                    \
+          function (value);                           \
+      }                                               \
+  } while (0)
+
+void
+ot_local_obj_unref (void *loc)
+{
+  _ot_local_free(GObject, g_object_unref);
+}
+
+void
+ot_local_variant_unref (void *loc)
+{
+  _ot_local_free(GVariant, g_variant_unref);
+}
+
+void
+ot_local_ptrarray_unref (void *loc)
+{
+  _ot_local_free(GPtrArray, g_ptr_array_unref);
+}
+
+void
+ot_local_hashtable_unref (void *loc)
+{
+  _ot_local_free(GHashTable, g_hash_table_unref);
+}