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#if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \
8 __has_attribute(btf_type_tag)
9# define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value)))
10#else
11# define BTF_TYPE_TAG(value) /* nothing */
12#endif
13
14/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
15#ifdef __CHECKER__
16/* address spaces */
17# define __kernel __attribute__((address_space(0)))
18# define __user __attribute__((noderef, address_space(__user)))
19# define __iomem __attribute__((noderef, address_space(__iomem)))
20# define __percpu __attribute__((noderef, address_space(__percpu)))
21# define __rcu __attribute__((noderef, address_space(__rcu)))
22static inline void __chk_user_ptr(const volatile void __user *ptr) { }
23static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
24/* context/locking */
25# define __must_hold(x) __attribute__((context(x,1,1)))
26# define __acquires(x) __attribute__((context(x,0,1)))
27# define __cond_acquires(x) __attribute__((context(x,0,-1)))
28# define __releases(x) __attribute__((context(x,1,0)))
29# define __acquire(x) __context__(x,1)
30# define __release(x) __context__(x,-1)
31# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
32/* other */
33# define __force __attribute__((force))
34# define __nocast __attribute__((nocast))
35# define __safe __attribute__((safe))
36# define __private __attribute__((noderef))
37# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
38#else /* __CHECKER__ */
39/* address spaces */
40# define __kernel
41# ifdef STRUCTLEAK_PLUGIN
42# define __user __attribute__((user))
43# else
44# define __user BTF_TYPE_TAG(user)
45# endif
46# define __iomem
47# define __percpu BTF_TYPE_TAG(percpu)
48# define __rcu
49# define __chk_user_ptr(x) (void)0
50# define __chk_io_ptr(x) (void)0
51/* context/locking */
52# define __must_hold(x)
53# define __acquires(x)
54# define __cond_acquires(x)
55# define __releases(x)
56# define __acquire(x) (void)0
57# define __release(x) (void)0
58# define __cond_lock(x,c) (c)
59/* other */
60# define __force
61# define __nocast
62# define __safe
63# define __private
64# define ACCESS_PRIVATE(p, member) ((p)->member)
65# define __builtin_warning(x, y...) (1)
66#endif /* __CHECKER__ */
67
68/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
69#define ___PASTE(a,b) a##b
70#define __PASTE(a,b) ___PASTE(a,b)
71
72#ifdef __KERNEL__
73
74/* Attributes */
75#include <linux/compiler_attributes.h>
76
77/* Builtins */
78
79/*
80 * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21.
81 * In the meantime, to support gcc < 10, we implement __has_builtin
82 * by hand.
83 */
84#ifndef __has_builtin
85#define __has_builtin(x) (0)
86#endif
87
88/* Compiler specific macros. */
89#ifdef __clang__
90#include <linux/compiler-clang.h>
91#elif defined(__INTEL_COMPILER)
92#include <linux/compiler-intel.h>
93#elif defined(__GNUC__)
94/* The above compilers also define __GNUC__, so order is important here. */
95#include <linux/compiler-gcc.h>
96#else
97#error "Unknown compiler"
98#endif
99
100/*
101 * Some architectures need to provide custom definitions of macros provided
102 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
103 * conditionally rather than using an asm-generic wrapper in order to avoid
104 * build failures if any C compilation, which will include this file via an
105 * -include argument in c_flags, occurs prior to the asm-generic wrappers being
106 * generated.
107 */
108#ifdef CONFIG_HAVE_ARCH_COMPILER_H
109#include <asm/compiler.h>
110#endif
111
112struct ftrace_branch_data {
113 const char *func;
114 const char *file;
115 unsigned line;
116 union {
117 struct {
118 unsigned long correct;
119 unsigned long incorrect;
120 };
121 struct {
122 unsigned long miss;
123 unsigned long hit;
124 };
125 unsigned long miss_hit[2];
126 };
127};
128
129struct ftrace_likely_data {
130 struct ftrace_branch_data data;
131 unsigned long constant;
132};
133
134#if defined(CC_USING_HOTPATCH)
135#define notrace __attribute__((hotpatch(0, 0)))
136#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
137#define notrace __attribute__((patchable_function_entry(0, 0)))
138#else
139#define notrace __attribute__((__no_instrument_function__))
140#endif
141
142/*
143 * it doesn't make sense on ARM (currently the only user of __naked)
144 * to trace naked functions because then mcount is called without
145 * stack and frame pointer being set up and there is no chance to
146 * restore the lr register to the value before mcount was called.
147 */
148#define __naked __attribute__((__naked__)) notrace
149
150/*
151 * Prefer gnu_inline, so that extern inline functions do not emit an
152 * externally visible function. This makes extern inline behave as per gnu89
153 * semantics rather than c99. This prevents multiple symbol definition errors
154 * of extern inline functions at link time.
155 * A lot of inline functions can cause havoc with function tracing.
156 */
157#define inline inline __gnu_inline __inline_maybe_unused notrace
158
159/*
160 * gcc provides both __inline__ and __inline as alternate spellings of
161 * the inline keyword, though the latter is undocumented. New kernel
162 * code should only use the inline spelling, but some existing code
163 * uses __inline__. Since we #define inline above, to ensure
164 * __inline__ has the same semantics, we need this #define.
165 *
166 * However, the spelling __inline is strictly reserved for referring
167 * to the bare keyword.
168 */
169#define __inline__ inline
170
171/*
172 * GCC does not warn about unused static inline functions for -Wunused-function.
173 * Suppress the warning in clang as well by using __maybe_unused, but enable it
174 * for W=1 build. This will allow clang to find unused functions. Remove the
175 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
176 */
177#ifdef KBUILD_EXTRA_WARN1
178#define __inline_maybe_unused
179#else
180#define __inline_maybe_unused __maybe_unused
181#endif
182
183/*
184 * Rather then using noinline to prevent stack consumption, use
185 * noinline_for_stack instead. For documentation reasons.
186 */
187#define noinline_for_stack noinline
188
189/*
190 * Sanitizer helper attributes: Because using __always_inline and
191 * __no_sanitize_* conflict, provide helper attributes that will either expand
192 * to __no_sanitize_* in compilation units where instrumentation is enabled
193 * (__SANITIZE_*__), or __always_inline in compilation units without
194 * instrumentation (__SANITIZE_*__ undefined).
195 */
196#ifdef __SANITIZE_ADDRESS__
197/*
198 * We can't declare function 'inline' because __no_sanitize_address conflicts
199 * with inlining. Attempt to inline it may cause a build failure.
200 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
201 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
202 */
203# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
204# define __no_sanitize_or_inline __no_kasan_or_inline
205#else
206# define __no_kasan_or_inline __always_inline
207#endif
208
209#ifdef __SANITIZE_THREAD__
210/*
211 * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin
212 * atomics even with __no_sanitize_thread (to avoid false positives in userspace
213 * ThreadSanitizer). The kernel's requirements are stricter and we really do not
214 * want any instrumentation with __no_kcsan.
215 *
216 * Therefore we add __disable_sanitizer_instrumentation where available to
217 * disable all instrumentation. See Kconfig.kcsan where this is mandatory.
218 */
219# define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation
220# define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused
221#else
222# define __no_kcsan
223#endif
224
225#ifndef __no_sanitize_or_inline
226#define __no_sanitize_or_inline __always_inline
227#endif
228
229/* Section for code which can't be instrumented at all */
230#define noinstr \
231 noinline notrace __attribute((__section__(".noinstr.text"))) \
232 __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage
233
234#endif /* __KERNEL__ */
235
236#endif /* __ASSEMBLY__ */
237
238/*
239 * The below symbols may be defined for one or more, but not ALL, of the above
240 * compilers. We don't consider that to be an error, so set them to nothing.
241 * For example, some of them are for compiler specific plugins.
242 */
243#ifndef __latent_entropy
244# define __latent_entropy
245#endif
246
247#if defined(RANDSTRUCT) && !defined(__CHECKER__)
248# define __randomize_layout __designated_init __attribute__((randomize_layout))
249# define __no_randomize_layout __attribute__((no_randomize_layout))
250/* This anon struct can add padding, so only enable it under randstruct. */
251# define randomized_struct_fields_start struct {
252# define randomized_struct_fields_end } __randomize_layout;
253#else
254# define __randomize_layout __designated_init
255# define __no_randomize_layout
256# define randomized_struct_fields_start
257# define randomized_struct_fields_end
258#endif
259
260#ifndef __noscs
261# define __noscs
262#endif
263
264#ifndef __nocfi
265# define __nocfi
266#endif
267
268#ifndef __cficanonical
269# define __cficanonical
270#endif
271
272/*
273 * Any place that could be marked with the "alloc_size" attribute is also
274 * a place to be marked with the "malloc" attribute. Do this as part of the
275 * __alloc_size macro to avoid redundant attributes and to avoid missing a
276 * __malloc marking.
277 */
278#ifdef __alloc_size__
279# define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc
280#else
281# define __alloc_size(x, ...) __malloc
282#endif
283
284#ifndef asm_volatile_goto
285#define asm_volatile_goto(x...) asm goto(x)
286#endif
287
288#ifdef CONFIG_CC_HAS_ASM_INLINE
289#define asm_inline asm __inline
290#else
291#define asm_inline asm
292#endif
293
294/* Are two types/vars the same type (ignoring qualifiers)? */
295#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
296
297/*
298 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
299 * non-scalar types unchanged.
300 */
301/*
302 * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
303 * is not type-compatible with 'signed char', and we define a separate case.
304 */
305#define __scalar_type_to_expr_cases(type) \
306 unsigned type: (unsigned type)0, \
307 signed type: (signed type)0
308
309#define __unqual_scalar_typeof(x) typeof( \
310 _Generic((x), \
311 char: (char)0, \
312 __scalar_type_to_expr_cases(char), \
313 __scalar_type_to_expr_cases(short), \
314 __scalar_type_to_expr_cases(int), \
315 __scalar_type_to_expr_cases(long), \
316 __scalar_type_to_expr_cases(long long), \
317 default: (x)))
318
319/* Is this type a native word size -- useful for atomic operations */
320#define __native_word(t) \
321 (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
322 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
323
324#ifdef __OPTIMIZE__
325# define __compiletime_assert(condition, msg, prefix, suffix) \
326 do { \
327 /* \
328 * __noreturn is needed to give the compiler enough \
329 * information to avoid certain possibly-uninitialized \
330 * warnings (regardless of the build failing). \
331 */ \
332 __noreturn extern void prefix ## suffix(void) \
333 __compiletime_error(msg); \
334 if (!(condition)) \
335 prefix ## suffix(); \
336 } while (0)
337#else
338# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
339#endif
340
341#define _compiletime_assert(condition, msg, prefix, suffix) \
342 __compiletime_assert(condition, msg, prefix, suffix)
343
344/**
345 * compiletime_assert - break build and emit msg if condition is false
346 * @condition: a compile-time constant condition to check
347 * @msg: a message to emit if condition is false
348 *
349 * In tradition of POSIX assert, this macro will break the build if the
350 * supplied condition is *false*, emitting the supplied error message if the
351 * compiler has support to do so.
352 */
353#define compiletime_assert(condition, msg) \
354 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
355
356#define compiletime_assert_atomic_type(t) \
357 compiletime_assert(__native_word(t), \
358 "Need native word sized stores/loads for atomicity.")
359
360/* Helpers for emitting diagnostics in pragmas. */
361#ifndef __diag
362#define __diag(string)
363#endif
364
365#ifndef __diag_GCC
366#define __diag_GCC(version, severity, string)
367#endif
368
369#define __diag_push() __diag(push)
370#define __diag_pop() __diag(pop)
371
372#define __diag_ignore(compiler, version, option, comment) \
373 __diag_ ## compiler(version, ignore, option)
374#define __diag_warn(compiler, version, option, comment) \
375 __diag_ ## compiler(version, warn, option)
376#define __diag_error(compiler, version, option, comment) \
377 __diag_ ## compiler(version, error, option)
378
379#ifndef __diag_ignore_all
380#define __diag_ignore_all(option, comment)
381#endif
382
383#endif /* __LINUX_COMPILER_TYPES_H */
384

source code of linux/include/linux/compiler_types.h