1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_COMPILER_TYPES_H
3#define __LINUX_COMPILER_TYPES_H
4
5/*
6 * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21.
7 * In the meantime, to support gcc < 10, we implement __has_builtin
8 * by hand.
9 */
10#ifndef __has_builtin
11#define __has_builtin(x) (0)
12#endif
13
14#ifndef __ASSEMBLY__
15
16/*
17 * Skipped when running bindgen due to a libclang issue;
18 * see https://github.com/rust-lang/rust-bindgen/issues/2244.
19 */
20#if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \
21 __has_attribute(btf_type_tag) && !defined(__BINDGEN__)
22# define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value)))
23#else
24# define BTF_TYPE_TAG(value) /* nothing */
25#endif
26
27/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
28#ifdef __CHECKER__
29/* address spaces */
30# define __kernel __attribute__((address_space(0)))
31# define __user __attribute__((noderef, address_space(__user)))
32# define __iomem __attribute__((noderef, address_space(__iomem)))
33# define __percpu __attribute__((noderef, address_space(__percpu)))
34# define __rcu __attribute__((noderef, address_space(__rcu)))
35static inline void __chk_user_ptr(const volatile void __user *ptr) { }
36static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
37/* context/locking */
38# define __must_hold(x) __attribute__((context(x,1,1)))
39# define __acquires(x) __attribute__((context(x,0,1)))
40# define __cond_acquires(x) __attribute__((context(x,0,-1)))
41# define __releases(x) __attribute__((context(x,1,0)))
42# define __acquire(x) __context__(x,1)
43# define __release(x) __context__(x,-1)
44# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
45/* other */
46# define __force __attribute__((force))
47# define __nocast __attribute__((nocast))
48# define __safe __attribute__((safe))
49# define __private __attribute__((noderef))
50# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
51#else /* __CHECKER__ */
52/* address spaces */
53# define __kernel
54# ifdef STRUCTLEAK_PLUGIN
55# define __user __attribute__((user))
56# else
57# define __user BTF_TYPE_TAG(user)
58# endif
59# define __iomem
60# define __percpu __percpu_qual BTF_TYPE_TAG(percpu)
61# define __rcu BTF_TYPE_TAG(rcu)
62
63# define __chk_user_ptr(x) (void)0
64# define __chk_io_ptr(x) (void)0
65/* context/locking */
66# define __must_hold(x)
67# define __acquires(x)
68# define __cond_acquires(x)
69# define __releases(x)
70# define __acquire(x) (void)0
71# define __release(x) (void)0
72# define __cond_lock(x,c) (c)
73/* other */
74# define __force
75# define __nocast
76# define __safe
77# define __private
78# define ACCESS_PRIVATE(p, member) ((p)->member)
79# define __builtin_warning(x, y...) (1)
80#endif /* __CHECKER__ */
81
82/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
83#define ___PASTE(a,b) a##b
84#define __PASTE(a,b) ___PASTE(a,b)
85
86#ifdef __KERNEL__
87
88/* Attributes */
89#include <linux/compiler_attributes.h>
90
91#if CONFIG_FUNCTION_ALIGNMENT > 0
92#define __function_aligned __aligned(CONFIG_FUNCTION_ALIGNMENT)
93#else
94#define __function_aligned
95#endif
96
97/*
98 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute
99 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute
100 *
101 * When -falign-functions=N is in use, we must avoid the cold attribute as
102 * GCC drops the alignment for cold functions. Worse, GCC can implicitly mark
103 * callees of cold functions as cold themselves, so it's not sufficient to add
104 * __function_aligned here as that will not ensure that callees are correctly
105 * aligned.
106 *
107 * See:
108 *
109 * https://lore.kernel.org/lkml/Y77%2FqVgvaJidFpYt@FVFF77S0Q05N
110 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c9
111 */
112#if defined(CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT) || (CONFIG_FUNCTION_ALIGNMENT == 0)
113#define __cold __attribute__((__cold__))
114#else
115#define __cold
116#endif
117
118/*
119 * On x86-64 and arm64 targets, __preserve_most changes the calling convention
120 * of a function to make the code in the caller as unintrusive as possible. This
121 * convention behaves identically to the C calling convention on how arguments
122 * and return values are passed, but uses a different set of caller- and callee-
123 * saved registers.
124 *
125 * The purpose is to alleviates the burden of saving and recovering a large
126 * register set before and after the call in the caller. This is beneficial for
127 * rarely taken slow paths, such as error-reporting functions that may be called
128 * from hot paths.
129 *
130 * Note: This may conflict with instrumentation inserted on function entry which
131 * does not use __preserve_most or equivalent convention (if in assembly). Since
132 * function tracing assumes the normal C calling convention, where the attribute
133 * is supported, __preserve_most implies notrace. It is recommended to restrict
134 * use of the attribute to functions that should or already disable tracing.
135 *
136 * Optional: not supported by gcc.
137 *
138 * clang: https://clang.llvm.org/docs/AttributeReference.html#preserve-most
139 */
140#if __has_attribute(__preserve_most__) && (defined(CONFIG_X86_64) || defined(CONFIG_ARM64))
141# define __preserve_most notrace __attribute__((__preserve_most__))
142#else
143# define __preserve_most
144#endif
145
146/*
147 * Annotating a function/variable with __retain tells the compiler to place
148 * the object in its own section and set the flag SHF_GNU_RETAIN. This flag
149 * instructs the linker to retain the object during garbage-cleanup or LTO
150 * phases.
151 *
152 * Note that the __used macro is also used to prevent functions or data
153 * being optimized out, but operates at the compiler/IR-level and may still
154 * allow unintended removal of objects during linking.
155 *
156 * Optional: only supported since gcc >= 11, clang >= 13
157 *
158 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-retain-function-attribute
159 * clang: https://clang.llvm.org/docs/AttributeReference.html#retain
160 */
161#if __has_attribute(__retain__) && \
162 (defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || \
163 defined(CONFIG_LTO_CLANG))
164# define __retain __attribute__((__retain__))
165#else
166# define __retain
167#endif
168
169/* Compiler specific macros. */
170#ifdef __clang__
171#include <linux/compiler-clang.h>
172#elif defined(__GNUC__)
173/* The above compilers also define __GNUC__, so order is important here. */
174#include <linux/compiler-gcc.h>
175#else
176#error "Unknown compiler"
177#endif
178
179/*
180 * Some architectures need to provide custom definitions of macros provided
181 * by linux/compiler-*.h, and can do so using asm/compiler.h. We include that
182 * conditionally rather than using an asm-generic wrapper in order to avoid
183 * build failures if any C compilation, which will include this file via an
184 * -include argument in c_flags, occurs prior to the asm-generic wrappers being
185 * generated.
186 */
187#ifdef CONFIG_HAVE_ARCH_COMPILER_H
188#include <asm/compiler.h>
189#endif
190
191struct ftrace_branch_data {
192 const char *func;
193 const char *file;
194 unsigned line;
195 union {
196 struct {
197 unsigned long correct;
198 unsigned long incorrect;
199 };
200 struct {
201 unsigned long miss;
202 unsigned long hit;
203 };
204 unsigned long miss_hit[2];
205 };
206};
207
208struct ftrace_likely_data {
209 struct ftrace_branch_data data;
210 unsigned long constant;
211};
212
213#if defined(CC_USING_HOTPATCH)
214#define notrace __attribute__((hotpatch(0, 0)))
215#elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY)
216#define notrace __attribute__((patchable_function_entry(0, 0)))
217#else
218#define notrace __attribute__((__no_instrument_function__))
219#endif
220
221/*
222 * it doesn't make sense on ARM (currently the only user of __naked)
223 * to trace naked functions because then mcount is called without
224 * stack and frame pointer being set up and there is no chance to
225 * restore the lr register to the value before mcount was called.
226 */
227#define __naked __attribute__((__naked__)) notrace
228
229/*
230 * Prefer gnu_inline, so that extern inline functions do not emit an
231 * externally visible function. This makes extern inline behave as per gnu89
232 * semantics rather than c99. This prevents multiple symbol definition errors
233 * of extern inline functions at link time.
234 * A lot of inline functions can cause havoc with function tracing.
235 */
236#define inline inline __gnu_inline __inline_maybe_unused notrace
237
238/*
239 * gcc provides both __inline__ and __inline as alternate spellings of
240 * the inline keyword, though the latter is undocumented. New kernel
241 * code should only use the inline spelling, but some existing code
242 * uses __inline__. Since we #define inline above, to ensure
243 * __inline__ has the same semantics, we need this #define.
244 *
245 * However, the spelling __inline is strictly reserved for referring
246 * to the bare keyword.
247 */
248#define __inline__ inline
249
250/*
251 * GCC does not warn about unused static inline functions for -Wunused-function.
252 * Suppress the warning in clang as well by using __maybe_unused, but enable it
253 * for W=1 build. This will allow clang to find unused functions. Remove the
254 * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
255 */
256#ifdef KBUILD_EXTRA_WARN1
257#define __inline_maybe_unused
258#else
259#define __inline_maybe_unused __maybe_unused
260#endif
261
262/*
263 * Rather then using noinline to prevent stack consumption, use
264 * noinline_for_stack instead. For documentation reasons.
265 */
266#define noinline_for_stack noinline
267
268/*
269 * Use noinline_for_tracing for functions that should not be inlined.
270 * For tracing reasons.
271 */
272#define noinline_for_tracing noinline
273
274/*
275 * Sanitizer helper attributes: Because using __always_inline and
276 * __no_sanitize_* conflict, provide helper attributes that will either expand
277 * to __no_sanitize_* in compilation units where instrumentation is enabled
278 * (__SANITIZE_*__), or __always_inline in compilation units without
279 * instrumentation (__SANITIZE_*__ undefined).
280 */
281#ifdef __SANITIZE_ADDRESS__
282/*
283 * We can't declare function 'inline' because __no_sanitize_address conflicts
284 * with inlining. Attempt to inline it may cause a build failure.
285 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
286 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
287 */
288# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
289# define __no_sanitize_or_inline __no_kasan_or_inline
290#else
291# define __no_kasan_or_inline __always_inline
292#endif
293
294#ifdef __SANITIZE_THREAD__
295/*
296 * Clang still emits instrumentation for __tsan_func_{entry,exit}() and builtin
297 * atomics even with __no_sanitize_thread (to avoid false positives in userspace
298 * ThreadSanitizer). The kernel's requirements are stricter and we really do not
299 * want any instrumentation with __no_kcsan.
300 *
301 * Therefore we add __disable_sanitizer_instrumentation where available to
302 * disable all instrumentation. See Kconfig.kcsan where this is mandatory.
303 */
304# define __no_kcsan __no_sanitize_thread __disable_sanitizer_instrumentation
305/*
306 * Type qualifier to mark variables where all data-racy accesses should be
307 * ignored by KCSAN. Note, the implementation simply marks these variables as
308 * volatile, since KCSAN will treat such accesses as "marked".
309 */
310# define __data_racy volatile
311# define __no_sanitize_or_inline __no_kcsan notrace __maybe_unused
312#else
313# define __no_kcsan
314# define __data_racy
315#endif
316
317#ifdef __SANITIZE_MEMORY__
318/*
319 * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined
320 * functions, therefore disabling KMSAN checks also requires disabling inlining.
321 *
322 * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors
323 * within the function and marks all its outputs as initialized.
324 */
325# define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused
326#endif
327
328#ifndef __no_sanitize_or_inline
329#define __no_sanitize_or_inline __always_inline
330#endif
331
332/*
333 * Optional: only supported since gcc >= 15
334 * Optional: only supported since clang >= 18
335 *
336 * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
337 * clang: https://github.com/llvm/llvm-project/pull/76348
338 *
339 * __bdos on clang < 19.1.2 can erroneously return 0:
340 * https://github.com/llvm/llvm-project/pull/110497
341 *
342 * __bdos on clang < 19.1.3 can be off by 4:
343 * https://github.com/llvm/llvm-project/pull/112636
344 */
345#ifdef CONFIG_CC_HAS_COUNTED_BY
346# define __counted_by(member) __attribute__((__counted_by__(member)))
347#else
348# define __counted_by(member)
349#endif
350
351/*
352 * Optional: only supported since gcc >= 15
353 * Optional: not supported by Clang
354 *
355 * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178
356 */
357#ifdef CONFIG_CC_HAS_MULTIDIMENSIONAL_NONSTRING
358# define __nonstring_array __attribute__((__nonstring__))
359#else
360# define __nonstring_array
361#endif
362
363/*
364 * Apply __counted_by() when the Endianness matches to increase test coverage.
365 */
366#ifdef __LITTLE_ENDIAN
367#define __counted_by_le(member) __counted_by(member)
368#define __counted_by_be(member)
369#else
370#define __counted_by_le(member)
371#define __counted_by_be(member) __counted_by(member)
372#endif
373
374/* Do not trap wrapping arithmetic within an annotated function. */
375#ifdef CONFIG_UBSAN_INTEGER_WRAP
376# define __signed_wrap __attribute__((no_sanitize("signed-integer-overflow")))
377#else
378# define __signed_wrap
379#endif
380
381/* Section for code which can't be instrumented at all */
382#define __noinstr_section(section) \
383 noinline notrace __attribute((__section__(section))) \
384 __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \
385 __no_sanitize_memory __signed_wrap
386
387#define noinstr __noinstr_section(".noinstr.text")
388
389/*
390 * The __cpuidle section is used twofold:
391 *
392 * 1) the original use -- identifying if a CPU is 'stuck' in idle state based
393 * on it's instruction pointer. See cpu_in_idle().
394 *
395 * 2) supressing instrumentation around where cpuidle disables RCU; where the
396 * function isn't strictly required for #1, this is interchangeable with
397 * noinstr.
398 */
399#define __cpuidle __noinstr_section(".cpuidle.text")
400
401#endif /* __KERNEL__ */
402
403#endif /* __ASSEMBLY__ */
404
405/*
406 * The below symbols may be defined for one or more, but not ALL, of the above
407 * compilers. We don't consider that to be an error, so set them to nothing.
408 * For example, some of them are for compiler specific plugins.
409 */
410#ifndef __latent_entropy
411# define __latent_entropy
412#endif
413
414#if defined(RANDSTRUCT) && !defined(__CHECKER__)
415# define __randomize_layout __designated_init __attribute__((randomize_layout))
416# define __no_randomize_layout __attribute__((no_randomize_layout))
417/* This anon struct can add padding, so only enable it under randstruct. */
418# define randomized_struct_fields_start struct {
419# define randomized_struct_fields_end } __randomize_layout;
420#else
421# define __randomize_layout __designated_init
422# define __no_randomize_layout
423# define randomized_struct_fields_start
424# define randomized_struct_fields_end
425#endif
426
427#ifndef __noscs
428# define __noscs
429#endif
430
431#ifndef __nocfi
432# define __nocfi
433#endif
434
435/*
436 * Any place that could be marked with the "alloc_size" attribute is also
437 * a place to be marked with the "malloc" attribute, except those that may
438 * be performing a _reallocation_, as that may alias the existing pointer.
439 * For these, use __realloc_size().
440 */
441#ifdef __alloc_size__
442# define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc
443# define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__)
444#else
445# define __alloc_size(x, ...) __malloc
446# define __realloc_size(x, ...)
447#endif
448
449/*
450 * When the size of an allocated object is needed, use the best available
451 * mechanism to find it. (For cases where sizeof() cannot be used.)
452 *
453 * Optional: only supported since gcc >= 12
454 *
455 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
456 * clang: https://clang.llvm.org/docs/LanguageExtensions.html#evaluating-object-size
457 */
458#if __has_builtin(__builtin_dynamic_object_size)
459#define __struct_size(p) __builtin_dynamic_object_size(p, 0)
460#define __member_size(p) __builtin_dynamic_object_size(p, 1)
461#else
462#define __struct_size(p) __builtin_object_size(p, 0)
463#define __member_size(p) __builtin_object_size(p, 1)
464#endif
465
466/*
467 * Determine if an attribute has been applied to a variable.
468 * Using __annotated needs to check for __annotated being available,
469 * or negative tests may fail when annotation cannot be checked. For
470 * example, see the definition of __is_cstr().
471 */
472#if __has_builtin(__builtin_has_attribute)
473#define __annotated(var, attr) __builtin_has_attribute(var, attr)
474#endif
475
476/*
477 * Some versions of gcc do not mark 'asm goto' volatile:
478 *
479 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979
480 *
481 * We do it here by hand, because it doesn't hurt.
482 */
483#ifndef asm_goto_output
484#define asm_goto_output(x...) asm volatile goto(x)
485#endif
486
487/*
488 * Clang has trouble with constraints with multiple
489 * alternative behaviors (mainly "g" and "rm").
490 */
491#ifndef ASM_INPUT_G
492 #define ASM_INPUT_G "g"
493 #define ASM_INPUT_RM "rm"
494#endif
495
496#ifdef CONFIG_CC_HAS_ASM_INLINE
497#define asm_inline asm __inline
498#else
499#define asm_inline asm
500#endif
501
502/* Are two types/vars the same type (ignoring qualifiers)? */
503#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
504
505/*
506 * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving
507 * non-scalar types unchanged.
508 */
509/*
510 * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char'
511 * is not type-compatible with 'signed char', and we define a separate case.
512 */
513#define __scalar_type_to_expr_cases(type) \
514 unsigned type: (unsigned type)0, \
515 signed type: (signed type)0
516
517#define __unqual_scalar_typeof(x) typeof( \
518 _Generic((x), \
519 char: (char)0, \
520 __scalar_type_to_expr_cases(char), \
521 __scalar_type_to_expr_cases(short), \
522 __scalar_type_to_expr_cases(int), \
523 __scalar_type_to_expr_cases(long), \
524 __scalar_type_to_expr_cases(long long), \
525 default: (x)))
526
527/* Is this type a native word size -- useful for atomic operations */
528#define __native_word(t) \
529 (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \
530 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
531
532#ifdef __OPTIMIZE__
533/*
534 * #ifdef __OPTIMIZE__ is only a good approximation; for instance "make
535 * CFLAGS_foo.o=-Og" defines __OPTIMIZE__, does not elide the conditional code
536 * and can break compilation with wrong error message(s). Combine with
537 * -U__OPTIMIZE__ when needed.
538 */
539# define __compiletime_assert(condition, msg, prefix, suffix) \
540 do { \
541 /* \
542 * __noreturn is needed to give the compiler enough \
543 * information to avoid certain possibly-uninitialized \
544 * warnings (regardless of the build failing). \
545 */ \
546 __noreturn extern void prefix ## suffix(void) \
547 __compiletime_error(msg); \
548 if (!(condition)) \
549 prefix ## suffix(); \
550 } while (0)
551#else
552# define __compiletime_assert(condition, msg, prefix, suffix) ((void)(condition))
553#endif
554
555#define _compiletime_assert(condition, msg, prefix, suffix) \
556 __compiletime_assert(condition, msg, prefix, suffix)
557
558/**
559 * compiletime_assert - break build and emit msg if condition is false
560 * @condition: a compile-time constant condition to check
561 * @msg: a message to emit if condition is false
562 *
563 * In tradition of POSIX assert, this macro will break the build if the
564 * supplied condition is *false*, emitting the supplied error message if the
565 * compiler has support to do so.
566 */
567#define compiletime_assert(condition, msg) \
568 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
569
570#define compiletime_assert_atomic_type(t) \
571 compiletime_assert(__native_word(t), \
572 "Need native word sized stores/loads for atomicity.")
573
574/* Helpers for emitting diagnostics in pragmas. */
575#ifndef __diag
576#define __diag(string)
577#endif
578
579#ifndef __diag_GCC
580#define __diag_GCC(version, severity, string)
581#endif
582
583#define __diag_push() __diag(push)
584#define __diag_pop() __diag(pop)
585
586#define __diag_ignore(compiler, version, option, comment) \
587 __diag_ ## compiler(version, ignore, option)
588#define __diag_warn(compiler, version, option, comment) \
589 __diag_ ## compiler(version, warn, option)
590#define __diag_error(compiler, version, option, comment) \
591 __diag_ ## compiler(version, error, option)
592
593#ifndef __diag_ignore_all
594#define __diag_ignore_all(option, comment)
595#endif
596
597#endif /* __LINUX_COMPILER_TYPES_H */
598

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