LXR linux/include/linux/compiler

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __LINUX_COMPILER_TYPES_H
   3#define __LINUX_COMPILER_TYPES_H
   4
   5#ifndef __ASSEMBLY__
   6
   7#ifdef __CHECKER__
   8/* address spaces */
   9# define __kernel       __attribute__((address_space(0)))
  10# define __user         __attribute__((noderef, address_space(__user)))
  11# define __iomem        __attribute__((noderef, address_space(__iomem)))
  12# define __percpu       __attribute__((noderef, address_space(__percpu)))
  13# define __rcu          __attribute__((noderef, address_space(__rcu)))
  14static inline void __chk_user_ptr(const volatile void __user *ptr) { }
  15static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
  16/* context/locking */
  17# define __must_hold(x) __attribute__((context(x,1,1)))
  18# define __acquires(x)  __attribute__((context(x,0,1)))
  19# define __releases(x)  __attribute__((context(x,1,0)))
  20# define __acquire(x)   __context__(x,1)
  21# define __release(x)   __context__(x,-1)
  22# define __cond_lock(x,c)       ((c) ? ({ __acquire(x); 1; }) : 0)
  23/* other */
  24# define __force        __attribute__((force))
  25# define __nocast       __attribute__((nocast))
  26# define __safe         __attribute__((safe))
  27# define __private      __attribute__((noderef))
  28# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
  29#else /* __CHECKER__ */
  30/* address spaces */
  31# define __kernel
  32# ifdef STRUCTLEAK_PLUGIN
  33#  define __user        __attribute__((user))
  34# else
  35#  define __user
  36# endif
  37# define __iomem
  38# define __percpu
  39# define __rcu
  40# define __chk_user_ptr(x)      (void)0
  41# define __chk_io_ptr(x)        (void)0
  42/* context/locking */
  43# define __must_hold(x)
  44# define __acquires(x)
  45# define __releases(x)
  46# define __acquire(x)   (void)0
  47# define __release(x)   (void)0
  48# define __cond_lock(x,c) (c)
  49/* other */
  50# define __force
  51# define __nocast
  52# define __safe
  53# define __private
  54# define ACCESS_PRIVATE(p, member) ((p)->member)
  55# define __builtin_warning(x, y...) (1)
  56#endif /* __CHECKER__ */
  57
  58/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
  59#define ___PASTE(a,b) a##b
  60#define __PASTE(a,b) ___PASTE(a,b)
  61
  62#ifdef __KERNEL__
  63
  64/* Attributes */
  65#include <linux/compiler_attributes.h>
  66
  67/* Compiler specific macros. */
  68#ifdef __clang__
  69#include <linux/compiler-clang.h>
  70#elif defined(__INTEL_COMPILER)
  71#include <linux/compiler-intel.h>
  72#elif defined(__GNUC__)
  73/* The above compilers also define __GNUC__, so order is important here. */
  74#include <linux/compiler-gcc.h>
  75#else
  76#error "Unknown compiler"
  77#endif
  78
  79/*
  80 * Some architectures need to provide custom definitions of macros provided
  81 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
  82 * conditionally rather than using an asm-generic wrapper in order to avoid
  83 * build failures if any C compilation, which will include this file via an
  84 * -include argument in c_flags, occurs prior to the asm-generic wrappers being
  85 * generated.
  86 */
  87#ifdef CONFIG_HAVE_ARCH_COMPILER_H
  88#include <asm/compiler.h>
  89#endif
  90
  91struct ftrace_branch_data {
  92        const char *func;
  93        const char *file;
  94        unsigned line;
  95        union {
  96                struct {
  97                        unsigned long correct;
  98                        unsigned long incorrect;
  99                };
 100                struct {
 101                        unsigned long miss;
 102                        unsigned long hit;
 103                };
 104                unsigned long miss_hit[2];
 105        };
 106};
 107
 108struct ftrace_likely_data {
 109        struct ftrace_branch_data       data;
 110        unsigned long                   constant;
 111};
 112
 113#ifdef CONFIG_ENABLE_MUST_CHECK
 114#define __must_check            __attribute__((__warn_unused_result__))
 115#else
 116#define __must_check
 117#endif
 118
 119#if defined(CC_USING_HOTPATCH)
 120#define notrace                 __attribute__((hotpatch(0, 0)))
 121#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
 122#define notrace                 __attribute__((patchable_function_entry(0, 0)))
 123#else
 124#define notrace                 __attribute__((__no_instrument_function__))
 125#endif
 126
 127/*
 128 * it doesn't make sense on ARM (currently the only user of __naked)
 129 * to trace naked functions because then mcount is called without
 130 * stack and frame pointer being set up and there is no chance to
 131 * restore the lr register to the value before mcount was called.
 132 */
 133#define __naked                 __attribute__((__naked__)) notrace
 134
 135#define __compiler_offsetof(a, b)       __builtin_offsetof(a, b)
 136
 137/*
 138 * Prefer gnu_inline, so that extern inline functions do not emit an
 139 * externally visible function. This makes extern inline behave as per gnu89
 140 * semantics rather than c99. This prevents multiple symbol definition errors
 141 * of extern inline functions at link time.
 142 * A lot of inline functions can cause havoc with function tracing.
 143 */
 144#define inline inline __gnu_inline __inline_maybe_unused notrace
 145
 146/*
 147 * gcc provides both __inline__ and __inline as alternate spellings of
 148 * the inline keyword, though the latter is undocumented. New kernel
 149 * code should only use the inline spelling, but some existing code
 150 * uses __inline__. Since we #define inline above, to ensure
 151 * __inline__ has the same semantics, we need this #define.
 152 *
 153 * However, the spelling __inline is strictly reserved for referring
 154 * to the bare keyword.
 155 */
 156#define __inline__ inline
 157
 158/*
 159 * GCC does not warn about unused static inline functions for -Wunused-function.
 160 * Suppress the warning in clang as well by using __maybe_unused, but enable it
 161 * for W=1 build. This will allow clang to find unused functions. Remove the
 162 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
 163 */
 164#ifdef KBUILD_EXTRA_WARN1
 165#define __inline_maybe_unused
 166#else
 167#define __inline_maybe_unused __maybe_unused
 168#endif
 169
 170/*
 171 * Rather then using noinline to prevent stack consumption, use
 172 * noinline_for_stack instead.  For documentation reasons.
 173 */
 174#define noinline_for_stack noinline
 175
 176/*
 177 * Sanitizer helper attributes: Because using __always_inline and
 178 * __no_sanitize_* conflict, provide helper attributes that will either expand
 179 * to __no_sanitize_* in compilation units where instrumentation is enabled
 180 * (__SANITIZE_*__), or __always_inline in compilation units without
 181 * instrumentation (__SANITIZE_*__ undefined).
 182 */
 183#ifdef __SANITIZE_ADDRESS__
 184/*
 185 * We can't declare function 'inline' because __no_sanitize_address conflicts
 186 * with inlining. Attempt to inline it may cause a build failure.
 187 *     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
 188 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
 189 */
 190# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
 191# define __no_sanitize_or_inline __no_kasan_or_inline
 192#else
 193# define __no_kasan_or_inline __always_inline
 194#endif
 195
 196#define __no_kcsan __no_sanitize_thread
 197#ifdef __SANITIZE_THREAD__
 198# define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused
 199#endif
 200
 201#ifndef __no_sanitize_or_inline
 202#define __no_sanitize_or_inline __always_inline
 203#endif
 204
 205/* Section for code which can't be instrumented at all */
 206#define noinstr                                                         \
 207        noinline notrace __attribute((__section__(".noinstr.text")))    \
 208        __no_kcsan __no_sanitize_address
 209
 210#endif /* __KERNEL__ */
 211
 212#endif /* __ASSEMBLY__ */
 213
 214/*
 215 * The below symbols may be defined for one or more, but not ALL, of the above
 216 * compilers. We don't consider that to be an error, so set them to nothing.
 217 * For example, some of them are for compiler specific plugins.
 218 */
 219#ifndef __latent_entropy
 220# define __latent_entropy
 221#endif
 222
 223#ifndef __randomize_layout
 224# define __randomize_layout __designated_init
 225#endif
 226
 227#ifndef __no_randomize_layout
 228# define __no_randomize_layout
 229#endif
 230
 231#ifndef randomized_struct_fields_start
 232# define randomized_struct_fields_start
 233# define randomized_struct_fields_end
 234#endif
 235
 236#ifndef __noscs
 237# define __noscs
 238#endif
 239
 240#ifndef asm_volatile_goto
 241#define asm_volatile_goto(x...) asm goto(x)
 242#endif
 243
 244#ifdef CONFIG_CC_HAS_ASM_INLINE
 245#define asm_inline asm __inline
 246#else
 247#define asm_inline asm
 248#endif
 249
 250#ifndef __no_fgcse
 251# define __no_fgcse
 252#endif
 253
 254/* Are two types/vars the same type (ignoring qualifiers)? */
 255#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
 256
 257/*
 258 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
 259 *                             non-scalar types unchanged.
 260 */
 261/*
 262 * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
 263 * is not type-compatible with 'signed char', and we define a separate case.
 264 */
 265#define __scalar_type_to_expr_cases(type)                               \
 266                unsigned type:  (unsigned type)0,                       \
 267                signed type:    (signed type)0
 268
 269#define __unqual_scalar_typeof(x) typeof(                               \
 270                _Generic((x),                                           \
 271                         char:  (char)0,                                \
 272                         __scalar_type_to_expr_cases(char),             \
 273                         __scalar_type_to_expr_cases(short),            \
 274                         __scalar_type_to_expr_cases(int),              \
 275                         __scalar_type_to_expr_cases(long),             \
 276                         __scalar_type_to_expr_cases(long long),        \
 277                         default: (x)))
 278
 279/* Is this type a native word size -- useful for atomic operations */
 280#define __native_word(t) \
 281        (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
 282         sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
 283
 284/* Compile time object size, -1 for unknown */
 285#ifndef __compiletime_object_size
 286# define __compiletime_object_size(obj) -1
 287#endif
 288#ifndef __compiletime_warning
 289# define __compiletime_warning(message)
 290#endif
 291#ifndef __compiletime_error
 292# define __compiletime_error(message)
 293#endif
 294
 295#ifdef __OPTIMIZE__
 296# define __compiletime_assert(condition, msg, prefix, suffix)           \
 297        do {                                                            \
 298                extern void prefix ## suffix(void) __compiletime_error(msg); \
 299                if (!(condition))                                       \
 300                        prefix ## suffix();                             \
 301        } while (0)
 302#else
 303# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
 304#endif
 305
 306#define _compiletime_assert(condition, msg, prefix, suffix) \
 307        __compiletime_assert(condition, msg, prefix, suffix)
 308
 309/**
 310 * compiletime_assert - break build and emit msg if condition is false
 311 * @condition: a compile-time constant condition to check
 312 * @msg:       a message to emit if condition is false
 313 *
 314 * In tradition of POSIX assert, this macro will break the build if the
 315 * supplied condition is *false*, emitting the supplied error message if the
 316 * compiler has support to do so.
 317 */
 318#define compiletime_assert(condition, msg) \
 319        _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
 320
 321#define compiletime_assert_atomic_type(t)                               \
 322        compiletime_assert(__native_word(t),                            \
 323                "Need native word sized stores/loads for atomicity.")
 324
 325/* Helpers for emitting diagnostics in pragmas. */
 326#ifndef __diag
 327#define __diag(string)
 328#endif
 329
 330#ifndef __diag_GCC
 331#define __diag_GCC(version, severity, string)
 332#endif
 333
 334#define __diag_push()   __diag(push)
 335#define __diag_pop()    __diag(pop)
 336
 337#define __diag_ignore(compiler, version, option, comment) \
 338        __diag_ ## compiler(version, ignore, option)
 339#define __diag_warn(compiler, version, option, comment) \
 340        __diag_ ## compiler(version, warn, option)
 341#define __diag_error(compiler, version, option, comment) \
 342        __diag_ ## compiler(version, error, option)
 343
 344#endif /* __LINUX_COMPILER_TYPES_H */
 345