Files
colorredstderr-mirror/src/compiler.h
2015-08-28 12:25:36 +02:00

54 lines
1.9 KiB
C

/*
* Compiler specific macros.
*
* Copyright (C) 2013-2015 Simon Ruderich
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef COMPILER_H
#define COMPILER_H 1
#ifdef HAVE___ATTRIBUTE__
/* Prevent/force inlining. Used to improve performance. */
# define noinline __attribute__((noinline))
# define always_inline __attribute__((always_inline))
/* Unused parameter. */
# define unused __attribute__((unused))
/* Mark the function protected, which means it can't be overwritten by other
* modules (libraries), e.g. with LD_PRELOAD); otherwise same as the default
* visibility. This causes the compiler not use the PLT (and no relocations)
* for local calls from inside this module; but the symbols are still
* exported. This is faster and in this case prevents useless lookups as we
* hook those functions and nobody else should modify them. Not strictly
* necessary, but nice to have. */
# define visibility_protected __attribute__((visibility("protected")))
#else
# define noinline
# define always_inline
# define unused
# define visibility_protected
#endif
/* Branch prediction information for the compiler. */
#ifdef HAVE___BUILTIN_EXPECT
# define likely(x) __builtin_expect(!!(x), 1)
# define unlikely(x) __builtin_expect(!!(x), 0)
#else
# define likely(x) x
# define unlikely(x) x
#endif
#endif