/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- * * Copyright (C) 2012,2015 Colin Walters * SPDX-License-Identifier: LGPL-2.0-or-later * * 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. */ #include "libglnx-config.h" #include "glnx-local-alloc.h" /** * SECTION:glnxlocalalloc * @title: GLnx local allocation * @short_description: Release local variables automatically when they go out of scope * * These macros leverage the GCC extension __attribute__ ((cleanup)) * to allow calling a cleanup function such as g_free() when a * variable goes out of scope. See * for more information on the attribute. * * The provided macros make it easy to use the cleanup attribute for * types that come with GLib. The primary two are #glnx_free and * #glnx_unref_object, which correspond to g_free() and * g_object_unref(), respectively. * * The rationale behind this is that particularly when handling error * paths, it can be very tricky to ensure the right variables are * freed. With this, one simply applies glnx_unref_object to a * locally-allocated #GFile for example, and it will be automatically * unreferenced when it goes out of scope. * * Note - you should only use these macros for stack * allocated variables. They don't provide garbage * collection or let you avoid freeing things. They're simply a * compiler assisted deterministic mechanism for calling a cleanup * function when a stack frame ends. * * Calling g_free automatically * * * GFile * * create_file (GError **error) * { * glnx_free char *random_id = NULL; * * if (!prepare_file (error)) * return NULL; * * random_id = alloc_random_id (); * * return create_file_real (error); * // Note that random_id is freed here automatically * } * * * */