Subversion Repositories Kolibri OS

#ifndef __LINUX_COMPILER_H

#error "Please don't include  directly, include  instead."

#endif

/*

 * Common definitions for all gcc versions go here.

 */

#define GCC_VERSION (__GNUC__ * 10000		\

		     + __GNUC_MINOR__ * 100	\

		     + __GNUC_PATCHLEVEL__)

/* Optimization barrier */

/* The "volatile" is due to gcc bugs */

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

/*

 * This version is i.e. to prevent dead stores elimination on @ptr

 * where gcc and llvm may behave differently when otherwise using

 * normal barrier(): while gcc behavior gets along with a normal

 * barrier(), llvm needs an explicit input variable to be assumed

 * clobbered. The issue is as follows: while the inline asm might

 * access any memory it wants, the compiler could have fit all of

 * @ptr into memory registers instead, and since @ptr never escaped

 * from that, it proofed that the inline asm wasn't touching any of

 * it. This version works well with both compilers, i.e. we're telling

 * the compiler that the inline asm absolutely may see the contents

 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495

 */

#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")

/*

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

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

 *

 * This is needed because the C standard makes it undefined to do

 * pointer arithmetic on "objects" outside their boundaries and the

 * gcc optimizers assume this is the case. In particular they

 * assume such arithmetic does not wrap.

 *

 * A miscompilation has been observed because of this on PPC.

 * To work around it we hide the relationship of the pointer and the object

 * using this macro.

 *

 * 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));					\

})

/* Make the optimizer believe the variable can be manipulated arbitrarily. */

#define OPTIMIZER_HIDE_VAR(var)						\

	__asm__ ("" : "=r" (var) : "0" (var))

#ifdef __CHECKER__

#define __must_be_array(a)	0

#else

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

#define __must_be_array(a)	BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))

#endif

/*

 * Force always-inline if the user requests it so via the .config,

 * or if gcc is too old:

 */

#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) ||		\

    !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)

#define inline		inline		__attribute__((always_inline)) notrace

#define __inline__	__inline__	__attribute__((always_inline)) notrace

#define __inline	__inline	__attribute__((always_inline)) notrace

#else

/* A lot of inline functions can cause havoc with function tracing */

#define inline		inline		notrace

#define __inline__	__inline__	notrace

#define __inline	__inline	notrace

#endif

#define __always_inline	inline __attribute__((always_inline))

#define  noinline	__attribute__((noinline))

#define __deprecated	__attribute__((deprecated))

#define __packed	__attribute__((packed))

#define __weak		__attribute__((weak))

#define __alias(symbol)	__attribute__((alias(#symbol)))

/*

 * it doesn't make sense on ARM (currently the only user of __naked)

 * to trace naked functions because then mcount is called without

 * stack and frame pointer being set up and there is no chance to

 * restore the lr register to the value before mcount was called.

 *

 * The asm() bodies of naked functions often depend on standard calling

 * conventions, therefore they must be noinline and noclone.

 *

 * GCC 4.[56] currently fail to enforce this, so we must do so ourselves.

 * See GCC PR44290.

 */

#define __naked		__attribute__((naked)) noinline __noclone notrace

#define __noreturn	__attribute__((noreturn))

/*

 * From the GCC manual:

 *

 * Many functions have no effects except the return value and their

 * return value depends only on the parameters and/or global

 * variables.  Such a function can be subject to common subexpression

 * elimination and loop optimization just as an arithmetic operator

 * would be.

 * [...]

 */

#define __pure			__attribute__((pure))

#define __aligned(x)		__attribute__((aligned(x)))

#define __printf(a, b)		__attribute__((format(printf, a, b)))

#define __scanf(a, b)		__attribute__((format(scanf, a, b)))

#define __attribute_const__	__attribute__((__const__))

#define __maybe_unused		__attribute__((unused))

#define __always_unused		__attribute__((unused))

/* gcc version specific checks */

#if GCC_VERSION < 30200

# error Sorry, your compiler is too old - please upgrade it.

#endif

#if GCC_VERSION < 30300

# define __used			__attribute__((__unused__))

#else

# define __used			__attribute__((__used__))

#endif

#ifdef CONFIG_GCOV_KERNEL

# if GCC_VERSION < 30400

#   error "GCOV profiling support for gcc versions below 3.4 not included"

# endif /* __GNUC_MINOR__ */

#endif /* CONFIG_GCOV_KERNEL */

#if GCC_VERSION >= 30400

#define __must_check		__attribute__((warn_unused_result))

#endif

#if GCC_VERSION >= 40000

/* GCC 4.1.[01] miscompiles __weak */

#ifdef __KERNEL__

# if GCC_VERSION >= 40100 &&  GCC_VERSION <= 40101

#  error Your version of gcc miscompiles the __weak directive

# endif

#endif

#define __used			__attribute__((__used__))

#define __compiler_offsetof(a, b)					\

	__builtin_offsetof(a, b)

#if GCC_VERSION >= 40100 && GCC_VERSION < 40600

# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)

#endif

#if GCC_VERSION >= 40300

/* Mark functions as cold. gcc will assume any path leading to a call

 * to them will be unlikely.  This means a lot of manual unlikely()s

 * are unnecessary now for any paths leading to the usual suspects

 * like BUG(), printk(), panic() etc. [but let's keep them for now for

 * older compilers]

 *

 * Early snapshots of gcc 4.3 don't support this and we can't detect this

 * in the preprocessor, but we can live with this because they're unreleased.

 * Maketime probing would be overkill here.

 *

 * gcc also has a __attribute__((__hot__)) to move hot functions into

 * a special section, but I don't see any sense in this right now in

 * the kernel context

 */

#define __cold			__attribute__((__cold__))

#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)

#ifndef __CHECKER__

# define __compiletime_warning(message) __attribute__((warning(message)))

# define __compiletime_error(message) __attribute__((error(message)))

#endif /* __CHECKER__ */

#endif /* GCC_VERSION >= 40300 */

#if GCC_VERSION >= 40500

/*

 * Mark a position in code as unreachable.  This can be used to

 * suppress control flow warnings after asm blocks that transfer

 * control elsewhere.

 *

 * Early snapshots of gcc 4.5 don't support this and we can't detect

 * this in the preprocessor, but we can live with this because they're

 * unreleased.  Really, we need to have autoconf for the kernel.

 */

#define unreachable() __builtin_unreachable()

/* Mark a function definition as prohibited from being cloned. */

#define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))

#endif /* GCC_VERSION >= 40500 */

#if GCC_VERSION >= 40600

/*

 * When used with Link Time Optimization, gcc can optimize away C functions or

 * variables which are referenced only from assembly code.  __visible tells the

 * optimizer that something else uses this function or variable, thus preventing

 * this.

 */

#define __visible	__attribute__((externally_visible))

#endif

#if GCC_VERSION >= 40900 && !defined(__CHECKER__)

/*

 * __assume_aligned(n, k): Tell the optimizer that the returned

 * pointer can be assumed to be k modulo n. The second argument is

 * optional (default 0), so we use a variadic macro to make the

 * shorthand.

 *

 * Beware: Do not apply this to functions which may return

 * ERR_PTRs. Also, it is probably unwise to apply it to functions

 * returning extra information in the low bits (but in that case the

 * compiler should see some alignment anyway, when the return value is

 * massaged by 'flags = ptr & 3; ptr &= ~3;').

 */

#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))

#endif

/*

 * GCC 'asm goto' miscompiles certain code sequences:

 *

 *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

 *

 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.

 *

 * (asm goto is automatically volatile - the naming reflects this.)

 */

#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)

#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP

#if GCC_VERSION >= 40400

#define __HAVE_BUILTIN_BSWAP32__

#define __HAVE_BUILTIN_BSWAP64__

#endif

#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)

#define __HAVE_BUILTIN_BSWAP16__

#endif

#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */

#if GCC_VERSION >= 50000

#define KASAN_ABI_VERSION 4

#elif GCC_VERSION >= 40902

#define KASAN_ABI_VERSION 3

#endif

#if GCC_VERSION >= 40902

/*

 * Tell the compiler that address safety instrumentation (KASAN)

 * should not be applied to that function.

 * Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368

 */

#define __no_sanitize_address __attribute__((no_sanitize_address))

#endif

#endif	/* gcc version >= 40000 specific checks */

#if !defined(__noclone)

#define __noclone	/* not needed */

#endif

#if !defined(__no_sanitize_address)

#define __no_sanitize_address

#endif

/*

 * A trick to suppress uninitialized variable warning without generating any

 * code

 */

#define uninitialized_var(x) x = x