2 * This file is part of cparser.
3 * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
24 * @brief Various utility functions that wrap compiler specific extensions
25 * @author Matthias Braun
32 * Asserts that the constant expression x is not zero at compiletime. name has
33 * to be a unique identifier.
35 * @note This uses the fact, that double case labels are not allowed.
37 #define COMPILETIME_ASSERT(x, name) \
38 static __attribute__((unused)) void compiletime_assert_##name (int h) { \
39 switch(h) { case 0: case (x): {} } \
43 * Indicates to the compiler that the value of x is very likely 1
44 * @note Only use this in speed critical code and when you are sure x is often 1
46 #define LIKELY(x) __builtin_expect((x), 1)
48 * Indicates to the compiler that it's very likely that x is 0
49 * @note Only use this in speed critical code and when you are sure x is often 0
51 #define UNLIKELY(x) __builtin_expect((x), 0)
53 #define lengthof(x) (sizeof(x) / sizeof(*(x)))
55 #define endof(x) ((x) + lengthof(x))