kernel / include / linux / compiler_types.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#define __LINUX_COMPILER_TYPES_H

#ifndef __ASSEMBLY__

#ifdef __CHECKER__
# define __kernel	__attribute__((address_space(0)))
# define __user		__attribute__((noderef, address_space(__user)))
# define __safe		__attribute__((safe))
# define __force	__attribute__((force))
# define __nocast	__attribute__((nocast))
# define __iomem	__attribute__((noderef, address_space(__iomem)))
# 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(__percpu)))
# define __rcu		__attribute__((noderef, address_space(__rcu)))
# define __private	__attribute__((noderef))
extern void __chk_user_ptr(const volatile void __user *);
extern void __chk_io_ptr(const volatile void __iomem *);
# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
#else /* __CHECKER__ */
# ifdef STRUCTLEAK_PLUGIN
#  define __user __attribute__((user))
# else
#  define __user
# endif
# 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
# define __private
# define ACCESS_PRIVATE(p, member) ((p)->member)
#endif /* __CHECKER__ */

/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
#define ___PASTE(a,b) a##b
#define __PASTE(a,b) ___PASTE(a,b)

#ifdef __KERNEL__

/* Attributes */
#include <linux/compiler_attributes.h>

/* Compiler specific macros. */
#ifdef __clang__
#include <linux/compiler-clang.h>
#elif defined(__INTEL_COMPILER)
#include <linux/compiler-intel.h>
#elif defined(__GNUC__)
/* The above compilers also define __GNUC__, so order is important here. */
#include <linux/compiler-gcc.h>
#else
#error "Unknown compiler"
#endif

/*
 * Some architectures need to provide custom definitions of macros provided
 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
 * conditionally rather than using an asm-generic wrapper in order to avoid
 * build failures if any C compilation, which will include this file via an
 * -include argument in c_flags, occurs prior to the asm-generic wrappers being
 * generated.
 */
#ifdef CONFIG_HAVE_ARCH_COMPILER_H
#include <asm/compiler.h>
#endif

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];
	};
};

struct ftrace_likely_data {
	struct ftrace_branch_data	data;
	unsigned long			constant;
};

#ifdef CONFIG_ENABLE_MUST_CHECK
#define __must_check		__attribute__((__warn_unused_result__))
#else
#define __must_check
#endif

#if defined(CC_USING_HOTPATCH)
#define notrace			__attribute__((hotpatch(0, 0)))
#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
#define notrace			__attribute__((patchable_function_entry(0, 0)))
#else
#define notrace			__attribute__((__no_instrument_function__))
#endif

/* Section for code which can't be instrumented at all */
#define noinstr								\
	noinline notrace __attribute((__section__(".noinstr.text")))

/*
 * 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.
 */
#define __naked			__attribute__((__naked__)) notrace

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

/*
 * Prefer gnu_inline, so that extern inline functions do not emit an
 * externally visible function. This makes extern inline behave as per gnu89
 * semantics rather than c99. This prevents multiple symbol definition errors
 * of extern inline functions at link time.
 * A lot of inline functions can cause havoc with function tracing.
 */
#define inline inline __gnu_inline __inline_maybe_unused notrace

/*
 * gcc provides both __inline__ and __inline as alternate spellings of
 * the inline keyword, though the latter is undocumented. New kernel
 * code should only use the inline spelling, but some existing code
 * uses __inline__. Since we #define inline above, to ensure
 * __inline__ has the same semantics, we need this #define.
 *
 * However, the spelling __inline is strictly reserved for referring
 * to the bare keyword.
 */
#define __inline__ inline

/*
 * GCC does not warn about unused static inline functions for -Wunused-function.
 * Suppress the warning in clang as well by using __maybe_unused, but enable it
 * for W=1 build. This will allow clang to find unused functions. Remove the
 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
 */
#ifdef KBUILD_EXTRA_WARN1
#define __inline_maybe_unused
#else
#define __inline_maybe_unused __maybe_unused
#endif

/*
 * Rather then using noinline to prevent stack consumption, use
 * noinline_for_stack instead.  For documentation reasons.
 */
#define noinline_for_stack noinline

/*
 * Sanitizer helper attributes: Because using __always_inline and
 * __no_sanitize_* conflict, provide helper attributes that will either expand
 * to __no_sanitize_* in compilation units where instrumentation is enabled
 * (__SANITIZE_*__), or __always_inline in compilation units without
 * instrumentation (__SANITIZE_*__ undefined).
 */
#ifdef __SANITIZE_ADDRESS__
/*
 * We can't declare function 'inline' because __no_sanitize_address conflicts
 * with inlining. Attempt to inline it may cause a build failure.
 *     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
 */
# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
# define __no_sanitize_or_inline __no_kasan_or_inline
#else
# define __no_kasan_or_inline __always_inline
#endif

#define __no_kcsan __no_sanitize_thread
#ifdef __SANITIZE_THREAD__
# define __no_kcsan_or_inline __no_kcsan notrace __maybe_unused
# define __no_sanitize_or_inline __no_kcsan_or_inline
#else
# define __no_kcsan_or_inline __always_inline
#endif

#ifndef __no_sanitize_or_inline
#define __no_sanitize_or_inline __always_inline
#endif

#endif /* __KERNEL__ */

#endif /* __ASSEMBLY__ */

/*
 * The below symbols may be defined for one or more, but not ALL, of the above
 * compilers. We don't consider that to be an error, so set them to nothing.
 * For example, some of them are for compiler specific plugins.
 */
#ifndef __latent_entropy
# define __latent_entropy
#endif

#ifndef __randomize_layout
# define __randomize_layout __designated_init
#endif

#ifndef __no_randomize_layout
# define __no_randomize_layout
#endif

#ifndef randomized_struct_fields_start
# define randomized_struct_fields_start
# define randomized_struct_fields_end
#endif

#ifndef __noscs
# define __noscs
#endif

#ifndef asm_volatile_goto
#define asm_volatile_goto(x...) asm goto(x)
#endif

#ifdef CONFIG_CC_HAS_ASM_INLINE
#define asm_inline asm __inline
#else
#define asm_inline asm
#endif

#ifndef __no_fgcse
# define __no_fgcse
#endif

/* Are two types/vars the same type (ignoring qualifiers)? */
#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))

/*
 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
 *			       non-scalar types unchanged.
 */
#if (defined(CONFIG_CC_IS_GCC) && CONFIG_GCC_VERSION < 40900) || defined(__CHECKER__)
/*
 * We build this out of a couple of helper macros in a vain attempt to
 * help you keep your lunch down while reading it.
 */
#define __pick_scalar_type(x, type, otherwise)					\
	__builtin_choose_expr(__same_type(x, type), (type)0, otherwise)

/*
 * 'char' is not type-compatible with either 'signed char' or 'unsigned char',
 * so we include the naked type here as well as the signed/unsigned variants.
 */
#define __pick_integer_type(x, type, otherwise)					\
	__pick_scalar_type(x, type,						\
		__pick_scalar_type(x, unsigned type,				\
			__pick_scalar_type(x, signed type, otherwise)))

#define __unqual_scalar_typeof(x) typeof(					\
	__pick_integer_type(x, char,						\
		__pick_integer_type(x, short,					\
			__pick_integer_type(x, int,				\
				__pick_integer_type(x, long,			\
					__pick_integer_type(x, long long, x))))))
#else
/*
 * If supported, prefer C11 _Generic for better compile-times. As above, 'char'
 * is not type-compatible with 'signed char', and we define a separate case.
 */
#define __scalar_type_to_expr_cases(type)				\
		unsigned type:	(unsigned type)0,			\
		signed type:	(signed type)0

#define __unqual_scalar_typeof(x) typeof(				\
		_Generic((x),						\
			 char:	(char)0,				\
			 __scalar_type_to_expr_cases(char),		\
			 __scalar_type_to_expr_cases(short),		\
			 __scalar_type_to_expr_cases(int),		\
			 __scalar_type_to_expr_cases(long),		\
			 __scalar_type_to_expr_cases(long long),	\
			 default: (x)))
#endif

/* Is this type a native word size -- useful for atomic operations */
#define __native_word(t) \
	(sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
	 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))

/* Helpers for emitting diagnostics in pragmas. */
#ifndef __diag
#define __diag(string)
#endif

#ifndef __diag_GCC
#define __diag_GCC(version, severity, string)
#endif

#define __diag_push()	__diag(push)
#define __diag_pop()	__diag(pop)

#define __diag_ignore(compiler, version, option, comment) \
	__diag_ ## compiler(version, ignore, option)
#define __diag_warn(compiler, version, option, comment) \
	__diag_ ## compiler(version, warn, option)
#define __diag_error(compiler, version, option, comment) \
	__diag_ ## compiler(version, error, option)

#endif /* __LINUX_COMPILER_TYPES_H */