1 /* Copyright (C) 1992-2023 Free Software Foundation, Inc.
2 Copyright The GNU Toolchain Authors.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #ifndef _SYS_CDEFS_H
20 #define _SYS_CDEFS_H 1
21
22 /* We are almost always included from features.h. */
23 #ifndef _FEATURES_H
24 # include <features.h>
25 #endif
26
27 /* The GNU libc does not support any K&R compilers or the traditional mode
28 of ISO C compilers anymore. Check for some of the combinations not
29 supported anymore. */
30 #if defined __GNUC__ && !defined __STDC__ && !defined __cplusplus
31 # error "You need a ISO C or C++ conforming compiler to use the glibc headers"
32 #endif
33
34 /* Some user header file might have defined this before. */
35 #undef __P
36 #undef __PMT
37
38 /* Compilers that lack __has_attribute may object to
39 #if defined __has_attribute && __has_attribute (...)
40 even though they do not need to evaluate the right-hand side of the &&.
41 Similarly for __has_builtin, etc. */
42 #if (defined __has_attribute \
43 && (!defined __clang_minor__ \
44 || 3 < __clang_major__ + (5 <= __clang_minor__)))
45 # define __glibc_has_attribute(attr) __has_attribute (attr)
46 #else
47 # define __glibc_has_attribute(attr) 0
48 #endif
49 #ifdef __has_builtin
50 # define __glibc_has_builtin(name) __has_builtin (name)
51 #else
52 # define __glibc_has_builtin(name) 0
53 #endif
54 #ifdef __has_extension
55 # define __glibc_has_extension(ext) __has_extension (ext)
56 #else
57 # define __glibc_has_extension(ext) 0
58 #endif
59
60 #if defined __GNUC__ || defined __clang__
61
62 /* All functions, except those with callbacks or those that
63 synchronize memory, are leaf functions. */
64 # if __GNUC_PREREQ (4, 6) && !defined _LIBC
65 # define __LEAF , __leaf__
66 # define __LEAF_ATTR __attribute__ ((__leaf__))
67 # else
68 # define __LEAF
69 # define __LEAF_ATTR
70 # endif
71
72 /* GCC can always grok prototypes. For C++ programs we add throw()
73 to help it optimize the function calls. But this only works with
74 gcc 2.8.x and egcs. For gcc 3.4 and up we even mark C functions
75 as non-throwing using a function attribute since programs can use
76 the -fexceptions options for C code as well. */
77 # if !defined __cplusplus \
78 && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
79 # define __THROW __attribute__ ((__nothrow__ __LEAF))
80 # define __THROWNL __attribute__ ((__nothrow__))
81 # define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
82 # define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
83 # else
84 # if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major__ >= 4)
85 # if __cplusplus >= 201103L
86 # define __THROW noexcept (true)
87 # else
88 # define __THROW throw ()
89 # endif
90 # define __THROWNL __THROW
91 # define __NTH(fct) __LEAF_ATTR fct __THROW
92 # define __NTHNL(fct) fct __THROW
93 # else
94 # define __THROW
95 # define __THROWNL
96 # define __NTH(fct) fct
97 # define __NTHNL(fct) fct
98 # endif
99 # endif
100
101 # if __GNUC_PREREQ (4, 3) || __glibc_has_attribute (__cold__)
102 # define __COLD __attribute__ ((__cold__))
103 # else
104 # define __COLD
105 # endif
106
107 #else /* Not GCC or clang. */
108
109 # if (defined __cplusplus \
110 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
111 # define __inline inline
112 # else
113 # define __inline /* No inline functions. */
114 # endif
115
116 # define __THROW
117 # define __THROWNL
118 # define __NTH(fct) fct
119 # define __COLD
120
121 #endif /* GCC || clang. */
122
123 /* These two macros are not used in glibc anymore. They are kept here
124 only because some other projects expect the macros to be defined. */
125 #define __P(args) args
126 #define __PMT(args) args
127
128 /* For these things, GCC behaves the ANSI way normally,
129 and the non-ANSI way under -traditional. */
130
131 #define __CONCAT(x,y) x ## y
132 #define __STRING(x) #x
133
134 /* This is not a typedef so `const __ptr_t' does the right thing. */
135 #define __ptr_t void *
136
137
138 /* C++ needs to know that types and declarations are C, not C++. */
139 #ifdef __cplusplus
140 # define __BEGIN_DECLS extern "C" {
141 # define __END_DECLS }
142 #else
143 # define __BEGIN_DECLS
144 # define __END_DECLS
145 #endif
146
147
148 /* Fortify support. */
149 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
150 #define __bos0(ptr) __builtin_object_size (ptr, 0)
151
152 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
153 #if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
154 || __GNUC_PREREQ (12, 0))
155 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
156 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
157 #else
158 # define __glibc_objsize0(__o) __bos0 (__o)
159 # define __glibc_objsize(__o) __bos (__o)
160 #endif
161
162 #if __USE_FORTIFY_LEVEL > 0
163 /* Compile time conditions to choose between the regular, _chk and _chk_warn
164 variants. These conditions should get evaluated to constant and optimized
165 away. */
166
167 #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
168 #define __glibc_unsigned_or_positive(__l) \
169 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \
170 || (__builtin_constant_p (__l) && (__l) > 0))
171
172 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
173 condition can be folded to a constant and if it is true, or unknown (-1) */
174 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \
175 ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
176 || (__glibc_unsigned_or_positive (__l) \
177 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
178 (__s), (__osz))) \
179 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
180
181 /* Conversely, we know at compile time that the length is unsafe if the
182 __L * __S <= __OBJSZ condition can be folded to a constant and if it is
183 false. */
184 #define __glibc_unsafe_len(__l, __s, __osz) \
185 (__glibc_unsigned_or_positive (__l) \
186 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
187 __s, __osz)) \
188 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
189
190 /* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
191 declared. */
192
193 #define __glibc_fortify(f, __l, __s, __osz, ...) \
194 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
195 ? __ ## f ## _alias (__VA_ARGS__) \
196 : (__glibc_unsafe_len (__l, __s, __osz) \
197 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
198 : __ ## f ## _chk (__VA_ARGS__, __osz)))
199
200 /* Fortify function f, where object size argument passed to f is the number of
201 elements and not total size. */
202
203 #define __glibc_fortify_n(f, __l, __s, __osz, ...) \
204 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
205 ? __ ## f ## _alias (__VA_ARGS__) \
206 : (__glibc_unsafe_len (__l, __s, __osz) \
207 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
208 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
209 #endif
210
211 #if __GNUC_PREREQ (4,3)
212 # define __warnattr(msg) __attribute__((__warning__ (msg)))
213 # define __errordecl(name, msg) \
214 extern void name (void) __attribute__((__error__ (msg)))
215 #else
216 # define __warnattr(msg)
217 # define __errordecl(name, msg) extern void name (void)
218 #endif
219
220 /* Support for flexible arrays.
221 Headers that should use flexible arrays only if they're "real"
222 (e.g. only if they won't affect sizeof()) should test
223 #if __glibc_c99_flexarr_available. */
224 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
225 # define __flexarr []
226 # define __glibc_c99_flexarr_available 1
227 #elif __GNUC_PREREQ (2,97) || defined __clang__
228 /* GCC 2.97 and clang support C99 flexible array members as an extension,
229 even when in C89 mode or compiling C++ (any version). */
230 # define __flexarr []
231 # define __glibc_c99_flexarr_available 1
232 #elif defined __GNUC__
233 /* Pre-2.97 GCC did not support C99 flexible arrays but did have
234 an equivalent extension with slightly different notation. */
235 # define __flexarr [0]
236 # define __glibc_c99_flexarr_available 1
237 #else
238 /* Some other non-C99 compiler. Approximate with [1]. */
239 # define __flexarr [1]
240 # define __glibc_c99_flexarr_available 0
241 #endif
242
243
244 /* __asm__ ("xyz") is used throughout the headers to rename functions
245 at the assembly language level. This is wrapped by the __REDIRECT
246 macro, in order to support compilers that can do this some other
247 way. When compilers don't support asm-names at all, we have to do
248 preprocessor tricks instead (which don't have exactly the right
249 semantics, but it's the best we can do).
250
251 Example:
252 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
253
254 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
255
256 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
257 # ifdef __cplusplus
258 # define __REDIRECT_NTH(name, proto, alias) \
259 name proto __THROW __asm__ (__ASMNAME (#alias))
260 # define __REDIRECT_NTHNL(name, proto, alias) \
261 name proto __THROWNL __asm__ (__ASMNAME (#alias))
262 # else
263 # define __REDIRECT_NTH(name, proto, alias) \
264 name proto __asm__ (__ASMNAME (#alias)) __THROW
265 # define __REDIRECT_NTHNL(name, proto, alias) \
266 name proto __asm__ (__ASMNAME (#alias)) __THROWNL
267 # endif
268 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
269 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
270
271 #ifndef __REDIRECT_FORTIFY
272 #define __REDIRECT_FORTIFY __REDIRECT
273 #endif
274
275 #ifndef __REDIRECT_FORTIFY_NTH
276 #define __REDIRECT_FORTIFY_NTH __REDIRECT_NTH
277 #endif
278
279 /*
280 #elif __SOME_OTHER_COMPILER__
281
282 # define __REDIRECT(name, proto, alias) name proto; \
283 _Pragma("let " #name " = " #alias)
284 */
285 #endif
286
287 /* GCC and clang have various useful declarations that can be made with
288 the '__attribute__' syntax. All of the ways we use this do fine if
289 they are omitted for compilers that don't understand it. */
290 #if !(defined __GNUC__ || defined __clang__)
291 # define __attribute__(xyz) /* Ignore */
292 #endif
293
294 /* At some point during the gcc 2.96 development the `malloc' attribute
295 for functions was introduced. We don't want to use it unconditionally
296 (although this would be possible) since it generates warnings. */
297 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
298 # define __attribute_malloc__ __attribute__ ((__malloc__))
299 #else
300 # define __attribute_malloc__ /* Ignore */
301 #endif
302
303 /* Tell the compiler which arguments to an allocation function
304 indicate the size of the allocation. */
305 #if __GNUC_PREREQ (4, 3)
306 # define __attribute_alloc_size__(params) \
307 __attribute__ ((__alloc_size__ params))
308 #else
309 # define __attribute_alloc_size__(params) /* Ignore. */
310 #endif
311
312 /* Tell the compiler which argument to an allocation function
313 indicates the alignment of the allocation. */
314 #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
315 # define __attribute_alloc_align__(param) \
316 __attribute__ ((__alloc_align__ param))
317 #else
318 # define __attribute_alloc_align__(param) /* Ignore. */
319 #endif
320
321 /* At some point during the gcc 2.96 development the `pure' attribute
322 for functions was introduced. We don't want to use it unconditionally
323 (although this would be possible) since it generates warnings. */
324 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
325 # define __attribute_pure__ __attribute__ ((__pure__))
326 #else
327 # define __attribute_pure__ /* Ignore */
328 #endif
329
330 /* This declaration tells the compiler that the value is constant. */
331 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
332 # define __attribute_const__ __attribute__ ((__const__))
333 #else
334 # define __attribute_const__ /* Ignore */
335 #endif
336
337 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
338 # define __attribute_maybe_unused__ __attribute__ ((__unused__))
339 #else
340 # define __attribute_maybe_unused__ /* Ignore */
341 #endif
342
343 /* At some point during the gcc 3.1 development the `used' attribute
344 for functions was introduced. We don't want to use it unconditionally
345 (although this would be possible) since it generates warnings. */
346 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
347 # define __attribute_used__ __attribute__ ((__used__))
348 # define __attribute_noinline__ __attribute__ ((__noinline__))
349 #else
350 # define __attribute_used__ __attribute__ ((__unused__))
351 # define __attribute_noinline__ /* Ignore */
352 #endif
353
354 /* Since version 3.2, gcc allows marking deprecated functions. */
355 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
356 # define __attribute_deprecated__ __attribute__ ((__deprecated__))
357 #else
358 # define __attribute_deprecated__ /* Ignore */
359 #endif
360
361 /* Since version 4.5, gcc also allows one to specify the message printed
362 when a deprecated function is used. clang claims to be gcc 4.2, but
363 may also support this feature. */
364 #if __GNUC_PREREQ (4,5) \
365 || __glibc_has_extension (__attribute_deprecated_with_message__)
366 # define __attribute_deprecated_msg__(msg) \
367 __attribute__ ((__deprecated__ (msg)))
368 #else
369 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__
370 #endif
371
372 /* At some point during the gcc 2.8 development the `format_arg' attribute
373 for functions was introduced. We don't want to use it unconditionally
374 (although this would be possible) since it generates warnings.
375 If several `format_arg' attributes are given for the same function, in
376 gcc-3.0 and older, all but the last one are ignored. In newer gccs,
377 all designated arguments are considered. */
378 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
379 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
380 #else
381 # define __attribute_format_arg__(x) /* Ignore */
382 #endif
383
384 /* At some point during the gcc 2.97 development the `strfmon' format
385 attribute for functions was introduced. We don't want to use it
386 unconditionally (although this would be possible) since it
387 generates warnings. */
388 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
389 # define __attribute_format_strfmon__(a,b) \
390 __attribute__ ((__format__ (__strfmon__, a, b)))
391 #else
392 # define __attribute_format_strfmon__(a,b) /* Ignore */
393 #endif
394
395 /* The nonnull function attribute marks pointer parameters that
396 must not be NULL. This has the name __nonnull in glibc,
397 and __attribute_nonnull__ in files shared with Gnulib to avoid
398 collision with a different __nonnull in DragonFlyBSD 5.9. */
399 #ifndef __attribute_nonnull__
400 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
401 # define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
402 # else
403 # define __attribute_nonnull__(params)
404 # endif
405 #endif
406 #ifndef __nonnull
407 # define __nonnull(params) __attribute_nonnull__ (params)
408 #endif
409
410 /* The returns_nonnull function attribute marks the return type of the function
411 as always being non-null. */
412 #ifndef __returns_nonnull
413 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
414 # define __returns_nonnull __attribute__ ((__returns_nonnull__))
415 # else
416 # define __returns_nonnull
417 # endif
418 #endif
419
420 /* If fortification mode, we warn about unused results of certain
421 function calls which can lead to problems. */
422 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
423 # define __attribute_warn_unused_result__ \
424 __attribute__ ((__warn_unused_result__))
425 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
426 # define __wur __attribute_warn_unused_result__
427 # endif
428 #else
429 # define __attribute_warn_unused_result__ /* empty */
430 #endif
431 #ifndef __wur
432 # define __wur /* Ignore */
433 #endif
434
435 /* Forces a function to be always inlined. */
436 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
437 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and
438 it conflicts with this definition. Therefore undefine it first to
439 allow either header to be included first. */
440 # undef __always_inline
441 # define __always_inline __inline __attribute__ ((__always_inline__))
442 #else
443 # undef __always_inline
444 # define __always_inline __inline
445 #endif
446
447 /* Associate error messages with the source location of the call site rather
448 than with the source location inside the function. */
449 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
450 # define __attribute_artificial__ __attribute__ ((__artificial__))
451 #else
452 # define __attribute_artificial__ /* Ignore */
453 #endif
454
455 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
456 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
457 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
458 older than 4.3 may define these macros and still not guarantee GNU inlining
459 semantics.
460
461 clang++ identifies itself as gcc-4.2, but has support for GNU inlining
462 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
463 __GNUC_GNU_INLINE__ macro definitions. */
464 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
465 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
466 || defined __GNUC_GNU_INLINE__)))
467 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
468 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
469 # define __extern_always_inline \
470 extern __always_inline __attribute__ ((__gnu_inline__))
471 # else
472 # define __extern_inline extern __inline
473 # define __extern_always_inline extern __always_inline
474 # endif
475 #endif
476
477 #ifdef __extern_always_inline
478 # define __fortify_function __extern_always_inline __attribute_artificial__
479 #endif
480
481 /* GCC 4.3 and above allow passing all anonymous arguments of an
482 __extern_always_inline function to some other vararg function. */
483 #if __GNUC_PREREQ (4,3)
484 # define __va_arg_pack() __builtin_va_arg_pack ()
485 # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
486 #endif
487
488 /* It is possible to compile containing GCC extensions even if GCC is
489 run in pedantic mode if the uses are carefully marked using the
490 `__extension__' keyword. But this is not generally available before
491 version 2.8. */
492 #if !(__GNUC_PREREQ (2,8) || defined __clang__)
493 # define __extension__ /* Ignore */
494 #endif
495
496 /* __restrict is known in EGCS 1.2 and above, and in clang.
497 It works also in C++ mode (outside of arrays), but only when spelled
498 as '__restrict', not 'restrict'. */
499 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
500 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
501 # define __restrict restrict
502 # else
503 # define __restrict /* Ignore */
504 # endif
505 #endif
506
507 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
508 array_name[restrict]
509 GCC 3.1 and clang support this.
510 This syntax is not usable in C++ mode. */
511 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
512 # define __restrict_arr __restrict
513 #else
514 # ifdef __GNUC__
515 # define __restrict_arr /* Not supported in old GCC. */
516 # else
517 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
518 # define __restrict_arr restrict
519 # else
520 /* Some other non-C99 compiler. */
521 # define __restrict_arr /* Not supported. */
522 # endif
523 # endif
524 #endif
525
526 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
527 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
528 # define __glibc_likely(cond) __builtin_expect ((cond), 1)
529 #else
530 # define __glibc_unlikely(cond) (cond)
531 # define __glibc_likely(cond) (cond)
532 #endif
533
534 #if (!defined _Noreturn \
535 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
536 && !(__GNUC_PREREQ (4,7) \
537 || (3 < __clang_major__ + (5 <= __clang_minor__))))
538 # if __GNUC_PREREQ (2,8)
539 # define _Noreturn __attribute__ ((__noreturn__))
540 # else
541 # define _Noreturn
542 # endif
543 #endif
544
545 #if __GNUC_PREREQ (8, 0)
546 /* Describes a char array whose address can safely be passed as the first
547 argument to strncpy and strncat, as the char array is not necessarily
548 a NUL-terminated string. */
549 # define __attribute_nonstring__ __attribute__ ((__nonstring__))
550 #else
551 # define __attribute_nonstring__
552 #endif
553
554 /* Undefine (also defined in libc-symbols.h). */
555 #undef __attribute_copy__
556 #if __GNUC_PREREQ (9, 0)
557 /* Copies attributes from the declaration or type referenced by
558 the argument. */
559 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
560 #else
561 # define __attribute_copy__(arg)
562 #endif
563
564 #if (!defined _Static_assert && !defined __cplusplus \
565 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
566 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
567 || defined __STRICT_ANSI__))
568 # define _Static_assert(expr, diagnostic) \
569 extern int (*__Static_assert_function (void)) \
570 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
571 #endif
572
573 /* Gnulib avoids including these, as they don't work on non-glibc or
574 older glibc platforms. */
575 #ifndef __GNULIB_CDEFS
576 # include <bits/wordsize.h>
577 # include <bits/long-double.h>
578 #endif
579
580 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
581 # ifdef __REDIRECT
582
583 /* Alias name defined automatically. */
584 # define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
585 # define __LDBL_REDIR_DECL(name) \
586 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
587 # define __REDIRECT_LDBL(name, proto, alias) \
588 name proto __asm (__ASMNAME ("__" #alias "ieee128"))
589
590 /* Alias name defined automatically, with leading underscores. */
591 # define __LDBL_REDIR2_DECL(name) \
592 extern __typeof (__##name) __##name \
593 __asm (__ASMNAME ("__" #name "ieee128"));
594
595 /* Alias name defined manually. */
596 # define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
597 # define __LDBL_REDIR1_DECL(name, alias) \
598 extern __typeof (name) name __asm (__ASMNAME (#alias));
599
600 # define __LDBL_REDIR1_NTH(name, proto, alias) \
601 __REDIRECT_NTH (name, proto, alias)
602 # define __REDIRECT_NTH_LDBL(name, proto, alias) \
603 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
604
605 /* Unused. */
606 # define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
607
608 # else
609 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
610 # endif
611 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
612 # define __LDBL_COMPAT 1
613 # ifdef __REDIRECT
614 # define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
615 # define __LDBL_REDIR(name, proto) \
616 __LDBL_REDIR1 (name, proto, __nldbl_##name)
617 # define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
618 # define __LDBL_REDIR_NTH(name, proto) \
619 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
620 # define __LDBL_REDIR2_DECL(name) \
621 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
622 # define __LDBL_REDIR1_DECL(name, alias) \
623 extern __typeof (name) name __asm (__ASMNAME (#alias));
624 # define __LDBL_REDIR_DECL(name) \
625 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
626 # define __REDIRECT_LDBL(name, proto, alias) \
627 __LDBL_REDIR1 (name, proto, __nldbl_##alias)
628 # define __REDIRECT_NTH_LDBL(name, proto, alias) \
629 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
630 # endif
631 #endif
632 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
633 || !defined __REDIRECT
634 # define __LDBL_REDIR1(name, proto, alias) name proto
635 # define __LDBL_REDIR(name, proto) name proto
636 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
637 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
638 # define __LDBL_REDIR2_DECL(name)
639 # define __LDBL_REDIR_DECL(name)
640 # ifdef __REDIRECT
641 # define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
642 # define __REDIRECT_NTH_LDBL(name, proto, alias) \
643 __REDIRECT_NTH (name, proto, alias)
644 # endif
645 #endif
646
647 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
648 intended for use in preprocessor macros.
649
650 Note: MESSAGE must be a _single_ string; concatenation of string
651 literals is not supported. */
652 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
653 # define __glibc_macro_warning1(message) _Pragma (#message)
654 # define __glibc_macro_warning(message) \
655 __glibc_macro_warning1 (GCC warning message)
656 #else
657 # define __glibc_macro_warning(msg)
658 #endif
659
660 /* Generic selection (ISO C11) is a C-only feature, available in GCC
661 since version 4.9. Previous versions do not provide generic
662 selection, even though they might set __STDC_VERSION__ to 201112L,
663 when in -std=c11 mode. Thus, we must check for !defined __GNUC__
664 when testing __STDC_VERSION__ for generic selection support.
665 On the other hand, Clang also defines __GNUC__, so a clang-specific
666 check is required to enable the use of generic selection. */
667 #if !defined __cplusplus \
668 && (__GNUC_PREREQ (4, 9) \
669 || __glibc_has_extension (c_generic_selections) \
670 || (!defined __GNUC__ && defined __STDC_VERSION__ \
671 && __STDC_VERSION__ >= 201112L))
672 # define __HAVE_GENERIC_SELECTION 1
673 #else
674 # define __HAVE_GENERIC_SELECTION 0
675 #endif
676
677 #if __GNUC_PREREQ (10, 0)
678 /* Designates a 1-based positional argument ref-index of pointer type
679 that can be used to access size-index elements of the pointed-to
680 array according to access mode, or at least one element when
681 size-index is not provided:
682 access (access-mode, <ref-index> [, <size-index>]) */
683 # define __attr_access(x) __attribute__ ((__access__ x))
684 /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
685 use the access attribute to get object sizes from function definition
686 arguments, so we can't use them on functions we fortify. Drop the object
687 size hints for such functions. */
688 # if __USE_FORTIFY_LEVEL == 3
689 # define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o)))
690 # else
691 # define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
692 # endif
693 # if __GNUC_PREREQ (11, 0)
694 # define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
695 # else
696 # define __attr_access_none(argno)
697 # endif
698 #else
699 # define __fortified_attr_access(a, o, s)
700 # define __attr_access(x)
701 # define __attr_access_none(argno)
702 #endif
703
704 #if __GNUC_PREREQ (11, 0)
705 /* Designates dealloc as a function to call to deallocate objects
706 allocated by the declared function. */
707 # define __attr_dealloc(dealloc, argno) \
708 __attribute__ ((__malloc__ (dealloc, argno)))
709 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
710 #else
711 # define __attr_dealloc(dealloc, argno)
712 # define __attr_dealloc_free
713 #endif
714
715 /* Specify that a function such as setjmp or vfork may return
716 twice. */
717 #if __GNUC_PREREQ (4, 1)
718 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
719 #else
720 # define __attribute_returns_twice__ /* Ignore. */
721 #endif
722
723 #endif /* sys/cdefs.h */