#ifndef __LINUX_COMPILER_H

#define __LINUX_COMPILER_H

#if !defined(__GNUC__) || (__GNUC__ < 4)

#error Sorry, your compiler is too old/not recognized.

#endif

#define barrier()     __asm__ __volatile__("": : :"memory")

#define likely(x)     __builtin_expect(!!(x),1)

#define unlikely(x)   __builtin_expect(!!(x),0)

#define inline        __inline__

#define always_inline __inline__ __attribute__ ((__always_inline__))

#define noinline      __attribute__((__noinline__))

#define noreturn      __attribute__((__noreturn__))

#define __packed      __attribute__((__packed__))

#if (!defined(__clang__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 5))

#define unreachable() do {} while (1)

#else

#define unreachable() __builtin_unreachable()

#endif

#ifdef __clang__

/* Clang can replace some vars with new automatic ones that go in .data;

 * mark all explicit-segment vars 'used' to prevent that. */

#define __section(s)      __used __attribute__((__section__(s)))

#else

#define __section(s)      __attribute__((__section__(s)))

#endif

#define __used_section(s) __used __attribute__((__section__(s)))

#define __text_section(s) __attribute__((__section__(s)))

#define __aligned(a) __attribute__((__aligned__(a)))

#ifdef INIT_SECTIONS_ONLY

/*

 * For sources indicated to have only init code, make sure even

 * inline functions not expanded inline get placed in .init.text.

 */

#include <xen/init.h>

#define __inline__ __inline__ __init

#endif

#define __attribute_pure__  __attribute__((__pure__))

#define __attribute_const__ __attribute__((__const__))

#define __transparent__     __attribute__((__transparent_union__))

/*

 * The difference between the following two attributes is that __used is

 * intended to be used in cases where a reference to an identifier may be

 * invisible to the compiler (e.g. an inline assembly operand not listed

 * in the asm()'s operands), preventing the compiler from eliminating the

 * variable or function.

 * __maybe_unused otoh is to be used to merely prevent warnings (e.g. when

 * an identifier is used only inside a preprocessor conditional, yet putting

 * its declaration/definition inside another conditional would harm code

 * readability).

 */

#define __used         __attribute__((__used__))

#define __maybe_unused __attribute__((__unused__))

#define __must_check __attribute__((__warn_unused_result__))

#define __nonnull(...) __attribute__((__nonnull__(__VA_ARGS__)))

#define offsetof(a,b) __builtin_offsetof(a,b)

#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L

#define alignof __alignof__

#endif

/* &a[0] degrades to a pointer: a different type from an array */

#define __must_be_array(a) \

  BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))

#ifdef GCC_HAS_VISIBILITY_ATTRIBUTE

/* Results in more efficient PIC code (no indirections through GOT or PLT). */

#pragma GCC visibility push(hidden)

#endif

/* This macro obfuscates arithmetic on a variable address so that gcc

   shouldn't recognize the original var, and make assumptions about it */

/*

 * Versions of the ppc64 compiler before 4.1 had a bug where use of

 * RELOC_HIDE could trash r30. The bug can be worked around by changing

 * the inline assembly constraint from =g to =r, in this particular

 * case either is valid.

 */

#define RELOC_HIDE(ptr, off)                    \

  ({ unsigned long __ptr;                       \

    __asm__ ("" : "=r"(__ptr) : "0"(ptr));      \

    (typeof(ptr)) (__ptr + (off)); })

#ifdef __GCC_ASM_FLAG_OUTPUTS__

# define ASM_FLAG_OUT(yes, no) yes

#else

# define ASM_FLAG_OUT(yes, no) no

#endif

/*

 * NB: we need to disable the gcc-compat warnings for clang in some places or

 * else it will complain with: "'break' is bound to loop, GCC binds it to

 * switch" when a switch is used inside of a while expression inside of a

 * switch statement, ie:

 *

 * switch ( ... )

 * {

 * case ...:

 *      while ( ({ int x; switch ( foo ) { case 1: x = 1; break; } x }) )

 *      {

 *              ...

 *

 * This has already been reported upstream:

 * http://bugs.llvm.org/show_bug.cgi?id=32595 

 */

#ifdef __clang__

# define CLANG_DISABLE_WARN_GCC_COMPAT_START                    \

    _Pragma("clang diagnostic push")                            \

    _Pragma("clang diagnostic ignored \"-Wgcc-compat\"")

# define CLANG_DISABLE_WARN_GCC_COMPAT_END                      \

    _Pragma("clang diagnostic pop")

#else

# define CLANG_DISABLE_WARN_GCC_COMPAT_START

# define CLANG_DISABLE_WARN_GCC_COMPAT_END

#endif

#endif /* __LINUX_COMPILER_H */