#ifndef __LINUX_COMPILER_H
  #define __LINUX_COMPILER_H
  
  #ifndef __ASSEMBLY__
  
  #ifdef __CHECKER__
  # define __user		__attribute__((noderef, address_space(1)))
  # define __kernel	__attribute__((address_space(0)))
  # define __safe		__attribute__((safe))
  # define __force	__attribute__((force))
  # define __nocast	__attribute__((nocast))
  # define __iomem	__attribute__((noderef, address_space(2)))
  # define __must_hold(x)	__attribute__((context(x,1,1)))
  # define __acquires(x)	__attribute__((context(x,0,1)))
  # define __releases(x)	__attribute__((context(x,1,0)))
  # define __acquire(x)	__context__(x,1)
  # define __release(x)	__context__(x,-1)
  # define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
  # define __percpu	__attribute__((noderef, address_space(3)))
  #ifdef CONFIG_SPARSE_RCU_POINTER
  # define __rcu		__attribute__((noderef, address_space(4)))
  #else
  # define __rcu
  #endif
  extern void __chk_user_ptr(const volatile void __user *);
  extern void __chk_io_ptr(const volatile void __iomem *);
  #else
  # define __user
  # define __kernel
  # define __safe
  # define __force
  # define __nocast
  # define __iomem
  # define __chk_user_ptr(x) (void)0
  # define __chk_io_ptr(x) (void)0
  # define __builtin_warning(x, y...) (1)
  # define __must_hold(x)
  # define __acquires(x)
  # define __releases(x)
  # define __acquire(x) (void)0
  # define __release(x) (void)0
  # define __cond_lock(x,c) (c)
  # define __percpu
  # define __rcu
  #endif
  
  /* Indirect macros required for expanded argument pasting, eg. __LINE__. */
  #define ___PASTE(a,b) a##b
  #define __PASTE(a,b) ___PASTE(a,b)
  
  #ifdef __KERNEL__
  
  #ifdef __GNUC__
  #include <linux/compiler-gcc.h>
  #endif
  
  #define notrace __attribute__((no_instrument_function))
  
  /* Intel compiler defines __GNUC__. So we will overwrite implementations
   * coming from above header files here
   */
  #ifdef __INTEL_COMPILER
  # include <linux/compiler-intel.h>
  #endif
  
  /* Clang compiler defines __GNUC__. So we will overwrite implementations
   * coming from above header files here
   */
  #ifdef __clang__
  #include <linux/compiler-clang.h>
  #endif
  
  /*
   * Generic compiler-dependent macros required for kernel
   * build go below this comment. Actual compiler/compiler version
   * specific implementations come from the above header files
   */
  
  struct ftrace_branch_data {
  	const char *func;
  	const char *file;
  	unsigned line;
  	union {
  		struct {
  			unsigned long correct;
  			unsigned long incorrect;
  		};
  		struct {
  			unsigned long miss;
  			unsigned long hit;
  		};
  		unsigned long miss_hit[2];
  	};
  };
  
  /*
   * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
   * to disable branch tracing on a per file basis.
   */
  #if defined(CONFIG_TRACE_BRANCH_PROFILING) \
      && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
  void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
  
  #define likely_notrace(x)	__builtin_expect(!!(x), 1)
  #define unlikely_notrace(x)	__builtin_expect(!!(x), 0)
  
  #define __branch_check__(x, expect) ({					\
  			int ______r;					\
  			static struct ftrace_branch_data		\
  				__attribute__((__aligned__(4)))		\
  				__attribute__((section("_ftrace_annotated_branch"))) \
  				______f = {				\
  				.func = __func__,			\
  				.file = __FILE__,			\
  				.line = __LINE__,			\
  			};						\
  			______r = likely_notrace(x);			\
  			ftrace_likely_update(&______f, ______r, expect); \
  			______r;					\
  		})
  
  /*
   * Using __builtin_constant_p(x) to ignore cases where the return
   * value is always the same.  This idea is taken from a similar patch
   * written by Daniel Walker.
   */
  # ifndef likely
  #  define likely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
  # endif
  # ifndef unlikely
  #  define unlikely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
  # endif
  
  #ifdef CONFIG_PROFILE_ALL_BRANCHES
  /*
   * "Define 'is'", Bill Clinton
   * "Define 'if'", Steven Rostedt
   */
  #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
  #define __trace_if(cond) \
  	if (__builtin_constant_p((cond)) ? !!(cond) :			\
  	({								\
  		int ______r;						\
  		static struct ftrace_branch_data			\
  			__attribute__((__aligned__(4)))			\
  			__attribute__((section("_ftrace_branch")))	\
  			______f = {					\
  				.func = __func__,			\
  				.file = __FILE__,			\
  				.line = __LINE__,			\
  			};						\
  		______r = !!(cond);					\
  		______f.miss_hit[______r]++;					\
  		______r;						\
  	}))
  #endif /* CONFIG_PROFILE_ALL_BRANCHES */
  
  #else
  # define likely(x)	__builtin_expect(!!(x), 1)
  # define unlikely(x)	__builtin_expect(!!(x), 0)
  #endif
  
  /* Optimization barrier */
  #ifndef barrier
  # define barrier() __memory_barrier()
  #endif
  
  /* Unreachable code */
  #ifndef unreachable
  # define unreachable() do { } while (1)
  #endif
  
  #ifndef RELOC_HIDE
  # define RELOC_HIDE(ptr, off)					\
    ({ unsigned long __ptr;					\
       __ptr = (unsigned long) (ptr);				\
      (typeof(ptr)) (__ptr + (off)); })
  #endif
  
  #ifndef OPTIMIZER_HIDE_VAR
  #define OPTIMIZER_HIDE_VAR(var) barrier()
  #endif
  
  /* Not-quite-unique ID. */
  #ifndef __UNIQUE_ID
  # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
  #endif
  
  #endif /* __KERNEL__ */
  
  #endif /* __ASSEMBLY__ */
  
  #ifdef __KERNEL__
  /*
   * Allow us to mark functions as 'deprecated' and have gcc emit a nice
   * warning for each use, in hopes of speeding the functions removal.
   * Usage is:
   * 		int __deprecated foo(void)
   */
  #ifndef __deprecated
  # define __deprecated		/* unimplemented */
  #endif
  
  #ifdef MODULE
  #define __deprecated_for_modules __deprecated
  #else
  #define __deprecated_for_modules
  #endif
  
  #ifndef __must_check
  #define __must_check
  #endif
  
  #ifndef CONFIG_ENABLE_MUST_CHECK
  #undef __must_check
  #define __must_check
  #endif
  #ifndef CONFIG_ENABLE_WARN_DEPRECATED
  #undef __deprecated
  #undef __deprecated_for_modules
  #define __deprecated
  #define __deprecated_for_modules
  #endif
  
  /*
   * Allow us to avoid 'defined but not used' warnings on functions and data,
   * as well as force them to be emitted to the assembly file.
   *
   * As of gcc 3.4, static functions that are not marked with attribute((used))
   * may be elided from the assembly file.  As of gcc 3.4, static data not so
   * marked will not be elided, but this may change in a future gcc version.
   *
   * NOTE: Because distributions shipped with a backported unit-at-a-time
   * compiler in gcc 3.3, we must define __used to be __attribute__((used))
   * for gcc >=3.3 instead of 3.4.
   *
   * In prior versions of gcc, such functions and data would be emitted, but
   * would be warned about except with attribute((unused)).
   *
   * Mark functions that are referenced only in inline assembly as __used so
   * the code is emitted even though it appears to be unreferenced.
   */
  #ifndef __used
  # define __used			/* unimplemented */
  #endif
  
  #ifndef __maybe_unused
  # define __maybe_unused		/* unimplemented */
  #endif
  
  #ifndef __always_unused
  # define __always_unused	/* unimplemented */
  #endif
  
  #ifndef noinline
  #define noinline
  #endif
  
  /*
   * Rather then using noinline to prevent stack consumption, use
   * noinline_for_stack instead.  For documentation reasons.
   */
  #define noinline_for_stack noinline
  
  #ifndef __always_inline
  #define __always_inline inline
  #endif
  
  #endif /* __KERNEL__ */
  
  /*
   * From the GCC manual:
   *
   * Many functions do not examine any values except their arguments,
   * and have no effects except the return value.  Basically this is
   * just slightly more strict class than the `pure' attribute above,
   * since function is not allowed to read global memory.
   *
   * Note that a function that has pointer arguments and examines the
   * data pointed to must _not_ be declared `const'.  Likewise, a
   * function that calls a non-`const' function usually must not be
   * `const'.  It does not make sense for a `const' function to return
   * `void'.
   */
  #ifndef __attribute_const__
  # define __attribute_const__	/* unimplemented */
  #endif
  
  /*
   * Tell gcc if a function is cold. The compiler will assume any path
   * directly leading to the call is unlikely.
   */
  
  #ifndef __cold
  #define __cold
  #endif
  
  /* Simple shorthand for a section definition */
  #ifndef __section
  # define __section(S) __attribute__ ((__section__(#S)))
  #endif
  
  #ifndef __visible
  #define __visible
  #endif
  
  /* Are two types/vars the same type (ignoring qualifiers)? */
  #ifndef __same_type
  # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
  #endif
  
  /* Is this type a native word size -- useful for atomic operations */
  #ifndef __native_word
  # define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
  #endif
  
  /* Compile time object size, -1 for unknown */
  #ifndef __compiletime_object_size
  # define __compiletime_object_size(obj) -1
  #endif
  #ifndef __compiletime_warning
  # define __compiletime_warning(message)
  #endif
  #ifndef __compiletime_error
  # define __compiletime_error(message)
  /*
   * Sparse complains of variable sized arrays due to the temporary variable in
   * __compiletime_assert. Unfortunately we can't just expand it out to make
   * sparse see a constant array size without breaking compiletime_assert on old
   * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
   */
  # ifndef __CHECKER__
  #  define __compiletime_error_fallback(condition) \
  	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
  # endif
  #endif
  #ifndef __compiletime_error_fallback
  # define __compiletime_error_fallback(condition) do { } while (0)
  #endif
  
  #define __compiletime_assert(condition, msg, prefix, suffix)		\
  	do {								\
  		bool __cond = !(condition);				\
  		extern void prefix ## suffix(void) __compiletime_error(msg); \
  		if (__cond)						\
  			prefix ## suffix();				\
  		__compiletime_error_fallback(__cond);			\
  	} while (0)
  
  #define _compiletime_assert(condition, msg, prefix, suffix) \
  	__compiletime_assert(condition, msg, prefix, suffix)
  
  /**
   * compiletime_assert - break build and emit msg if condition is false
   * @condition: a compile-time constant condition to check
   * @msg:       a message to emit if condition is false
   *
   * In tradition of POSIX assert, this macro will break the build if the
   * supplied condition is *false*, emitting the supplied error message if the
   * compiler has support to do so.
   */
  #define compiletime_assert(condition, msg) \
  	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  
  #define compiletime_assert_atomic_type(t)				\
  	compiletime_assert(__native_word(t),				\
  		"Need native word sized stores/loads for atomicity.")
  
  /*
   * Prevent the compiler from merging or refetching accesses.  The compiler
   * is also forbidden from reordering successive instances of ACCESS_ONCE(),
   * but only when the compiler is aware of some particular ordering.  One way
   * to make the compiler aware of ordering is to put the two invocations of
   * ACCESS_ONCE() in different C statements.
   *
   * This macro does absolutely -nothing- to prevent the CPU from reordering,
   * merging, or refetching absolutely anything at any time.  Its main intended
   * use is to mediate communication between process-level code and irq/NMI
   * handlers, all running on the same CPU.
   */
  #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
  
  /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
  #ifdef CONFIG_KPROBES
  # define __kprobes	__attribute__((__section__(".kprobes.text")))
  # define nokprobe_inline	__always_inline
  #else
  # define __kprobes
  # define nokprobe_inline	inline
  #endif
  #endif /* __LINUX_COMPILER_H */