system/include/pedigree/kernel/compiler.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef KERNEL_COMPILER_H
#define KERNEL_COMPILER_H

// NOTE: See http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
//           http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html
//           http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
//           http://www.imodulo.com/gnu/gcc/Other-Builtins.html
//       for more information.

#define DEPRECATED __attribute__((deprecated))

#define NORETURN __attribute__((noreturn))

#define PURE __attribute__((pure))

#define CONST __attribute__((const))

#define ALWAYS_INLINE __attribute__((always_inline))

#define NEVER_INLINE __attribute__((noinline))

#define ALIGN(x) __attribute__((aligned(x)))

#define PACKED __attribute__((packed))

#define MAY_ALIAS __attribute__((may_alias))

#define LIKELY(exp) __builtin_expect(!!(exp), 1)

#define UNLIKELY(exp) __builtin_expect(!!(exp), 0)

#define UNREACHABLE __builtin_unreachable()

#define FORMAT(type, idx, first) __attribute__((format(type, idx, first)))

#define IS_CONSTANT(x) __builtin_constant_p(x)

#ifdef __MACH__  // Mach targets have special section specifications.
#define SECTION(x)
#else
#define SECTION(x) __attribute__((__section__(x)))
#endif

#define MUST_USE_RESULT __attribute__((warn_unused_result))

#define USED __attribute__((used))

#define WEAK __attribute__((weak))

#define EXPORTED_PUBLIC __attribute__((visibility("default")))

// Builtin checks.
#ifndef __has_builtin
#define __has_builtin(x) 0
#endif

#ifndef __has_feature
#define __has_feature(x) 0
#endif

#if __has_builtin(__builtin_assume_aligned) || !defined(__clang__)
#define ASSUME_ALIGNMENT(b, sz) __builtin_assume_aligned((b), sz)
#else
#define ASSUME_ALIGNMENT(b, sz) \
    ((reinterpret_cast<uintptr_t>(b) % (sz)) == 0) ? (b) : (UNREACHABLE, (b))
#endif

#define INITIALISATION_ONLY SECTION(".init.text")
#define INITIALISATION_ONLY_DATA SECTION(".init.data")

// We don't use a custom allocator if asan is enabled.
#if __has_feature(address_sanitizer) || __has_feature(memory_sanitizer)
#define HAS_ADDRESS_SANITIZER 1
#else
#define HAS_ADDRESS_SANITIZER 0
#endif

#if __has_feature(thread_sanitizer)
#define HAS_THREAD_SANITIZER 1
#else
#define HAS_THREAD_SANITIZER 0
#endif

#if HAS_ADDRESS_SANITIZER || HAS_THREAD_SANITIZER
#define HAS_SANITIZERS 1
#endif

#ifdef __cplusplus
#define NOT_COPY_CONSTRUCTIBLE(Type) Type(const Type &) = delete
#define NOT_ASSIGNABLE(Type) Type &operator=(const Type &) = delete
#define NOT_COPYABLE_OR_ASSIGNABLE(Type) \
    NOT_COPY_CONSTRUCTIBLE(Type);        \
    NOT_ASSIGNABLE(Type)

#define WITHOUT_IMPLICIT_CONSTRUCTORS(Type) \
    Type() = delete;                        \
    NOT_COPYABLE_OR_ASSIGNABLE(Type)
#endif

// BARRIER forces GCC to not reorder code across the barrier.
#define BARRIER() __asm__ __volatile__("" ::: "memory")

// FENCE performs a full load/store hardware memory fence.
#define FENCE() __sync_synchronize()

// Export thread-safety annotations if we're being compiled by clang
#include "pedigree/kernel/utilities/threadsafety.h"  // IWYU: export

#endif