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