1/* Copyright (C) 1992-2025 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/* The overloadable attribute was added on clang 2.6. */
149#if defined __clang_major__ \
150 && (__clang_major__ + (__clang_minor__ >= 6) > 2)
151# define __attribute_overloadable__ __attribute__((__overloadable__))
152#else
153# define __attribute_overloadable__
154#endif
155
156/* Fortify support. */
157#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
158#define __bos0(ptr) __builtin_object_size (ptr, 0)
159
160/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
161#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
162 || __GNUC_PREREQ (12, 0))
163# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
164# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
165#else
166# define __glibc_objsize0(__o) __bos0 (__o)
167# define __glibc_objsize(__o) __bos (__o)
168#endif
169
170#if __USE_FORTIFY_LEVEL > 0
171/* Compile time conditions to choose between the regular, _chk and _chk_warn
172 variants. These conditions should get evaluated to constant and optimized
173 away. */
174
175#define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
176#define __glibc_unsigned_or_positive(__l) \
177 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \
178 || (__builtin_constant_p (__l) && (__l) > 0))
179
180/* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
181 condition can be folded to a constant and if it is true, or unknown (-1) */
182#define __glibc_safe_or_unknown_len(__l, __s, __osz) \
183 ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
184 || (__glibc_unsigned_or_positive (__l) \
185 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
186 (__s), (__osz))) \
187 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
188
189/* Conversely, we know at compile time that the length is unsafe if the
190 __L * __S <= __OBJSZ condition can be folded to a constant and if it is
191 false. */
192#define __glibc_unsafe_len(__l, __s, __osz) \
193 (__glibc_unsigned_or_positive (__l) \
194 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
195 __s, __osz)) \
196 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
197
198/* To correctly instrument the fortify wrapper clang requires the
199 pass_object_size attribute, and the attribute has the restriction that the
200 argument needs to be 'const'. Furthermore, to make it usable with C
201 interfaces, clang provides the overload attribute, which provides a C++
202 like function overload support. The overloaded fortify wrapper with the
203 pass_object_size attribute has precedence over the default symbol.
204
205 Also, clang does not support __va_arg_pack, so variadic functions are
206 expanded to issue va_arg implementations. The error function must not have
207 bodies (address takes are expanded to nonfortified calls), and with
208 __fortify_function compiler might still create a body with the C++
209 mangling name (due to the overload attribute). In this case, the function
210 is defined with __fortify_function_error_function macro instead.
211
212 The argument size check is also done with a clang-only attribute,
213 __attribute__ ((__diagnose_if__ (...))), different than gcc which calls
214 symbol_chk_warn alias with uses __warnattr attribute.
215
216 The pass_object_size was added on clang 4.0, __diagnose_if__ on 5.0,
217 and pass_dynamic_object_size on 9.0. */
218#if defined __clang_major__ && __clang_major__ >= 5
219# define __fortify_use_clang 1
220
221# define __fortify_function_error_function static __attribute__((__unused__))
222
223# define __fortify_clang_pass_object_size_n(n) \
224 __attribute__ ((__pass_object_size__ (n)))
225# define __fortify_clang_pass_object_size0 \
226 __fortify_clang_pass_object_size_n (0)
227# define __fortify_clang_pass_object_size \
228 __fortify_clang_pass_object_size_n (__USE_FORTIFY_LEVEL > 1)
229
230# if __clang_major__ >= 9
231# define __fortify_clang_pass_dynamic_object_size_n(n) \
232 __attribute__ ((__pass_dynamic_object_size__ (n)))
233# define __fortify_clang_pass_dynamic_object_size0 \
234 __fortify_clang_pass_dynamic_object_size_n (0)
235# define __fortify_clang_pass_dynamic_object_size \
236 __fortify_clang_pass_dynamic_object_size_n (1)
237# else
238# define __fortify_clang_pass_dynamic_object_size_n(n)
239# define __fortify_clang_pass_dynamic_object_size0
240# define __fortify_clang_pass_dynamic_object_size
241# endif
242
243# define __fortify_clang_bos_static_lt_impl(bos_val, n, s) \
244 ((bos_val) != -1ULL && (n) > (bos_val) / (s))
245# define __fortify_clang_bos_static_lt2(__n, __e, __s) \
246 __fortify_clang_bos_static_lt_impl (__bos (__e), __n, __s)
247# define __fortify_clang_bos_static_lt(__n, __e) \
248 __fortify_clang_bos_static_lt2 (__n, __e, 1)
249# define __fortify_clang_bos0_static_lt2(__n, __e, __s) \
250 __fortify_clang_bos_static_lt_impl (__bos0 (__e), __n, __s)
251# define __fortify_clang_bos0_static_lt(__n, __e) \
252 __fortify_clang_bos0_static_lt2 (__n, __e, 1)
253
254# define __fortify_clang_bosn_args(bos_fn, n, buf, div, complaint) \
255 (__fortify_clang_bos_static_lt_impl (bos_fn (buf), n, div)), (complaint), \
256 "warning"
257
258# define __fortify_clang_warning(__c, __msg) \
259 __attribute__ ((__diagnose_if__ ((__c), (__msg), "warning")))
260# define __fortify_clang_error(__c, __msg) \
261 __attribute__ ((__diagnose_if__ ((__c), (__msg), "error")))
262# define __fortify_clang_warning_only_if_bos0_lt(n, buf, complaint) \
263 __attribute__ ((__diagnose_if__ \
264 (__fortify_clang_bosn_args (__bos0, n, buf, 1, complaint))))
265# define __fortify_clang_warning_only_if_bos0_lt2(n, buf, div, complaint) \
266 __attribute__ ((__diagnose_if__ \
267 (__fortify_clang_bosn_args (__bos0, n, buf, div, complaint))))
268# define __fortify_clang_warning_only_if_bos_lt(n, buf, complaint) \
269 __attribute__ ((__diagnose_if__ \
270 (__fortify_clang_bosn_args (__bos, n, buf, 1, complaint))))
271# define __fortify_clang_warning_only_if_bos_lt2(n, buf, div, complaint) \
272 __attribute__ ((__diagnose_if__ \
273 (__fortify_clang_bosn_args (__bos, n, buf, div, complaint))))
274
275# define __fortify_clang_prefer_this_overload \
276 __attribute__ ((enable_if (1, "")))
277# define __fortify_clang_unavailable(__msg) \
278 __attribute__ ((unavailable(__msg)))
279
280# if __USE_FORTIFY_LEVEL == 3
281# define __fortify_clang_overload_arg(__type, __attr, __name) \
282 __type __attr const __fortify_clang_pass_dynamic_object_size __name
283# define __fortify_clang_overload_arg0(__type, __attr, __name) \
284 __type __attr const __fortify_clang_pass_dynamic_object_size0 __name
285# else
286# define __fortify_clang_overload_arg(__type, __attr, __name) \
287 __type __attr const __fortify_clang_pass_object_size __name
288# define __fortify_clang_overload_arg0(__type, __attr, __name) \
289 __type __attr const __fortify_clang_pass_object_size0 __name
290# endif
291
292# define __fortify_clang_mul_may_overflow(size, n) \
293 ((size | n) >= (((size_t)1) << (8 * sizeof (size_t) / 2)))
294
295# define __fortify_clang_size_too_small(__bos, __dest, __len) \
296 (__bos (__dest) != (size_t) -1 && __bos (__dest) < __len)
297# define __fortify_clang_warn_if_src_too_large(__dest, __src) \
298 __fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
299 __dest, \
300 __builtin_strlen (__src) + 1), \
301 "destination buffer will always be overflown by source")
302# define __fortify_clang_warn_if_dest_too_small(__dest, __len) \
303 __fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize, \
304 __dest, \
305 __len), \
306 "function called with bigger length than the destination buffer")
307# define __fortify_clang_warn_if_dest_too_small0(__dest, __len) \
308 __fortify_clang_warning (__fortify_clang_size_too_small (__glibc_objsize0, \
309 __dest, \
310 __len), \
311 "function called with bigger length than the destination buffer")
312#else
313# define __fortify_use_clang 0
314# define __fortify_clang_warning(__c, __msg)
315# define __fortify_clang_warning_only_if_bos0_lt(__n, __buf, __complaint)
316# define __fortify_clang_warning_only_if_bos0_lt2(__n, __buf, __div, complaint)
317# define __fortify_clang_warning_only_if_bos_lt(__n, __buf, __complaint)
318# define __fortify_clang_warning_only_if_bos_lt2(__n, __buf, div, __complaint)
319# define __fortify_clang_overload_arg(__type, __attr, __name) \
320 __type __attr __name
321# define __fortify_clang_overload_arg0(__type, __attr, __name) \
322 __fortify_clang_overload_arg (__type, __attr, __name)
323# define __fortify_clang_warn_if_src_too_large(__dest, __src)
324# define __fortify_clang_warn_if_dest_too_small(__dest, __len)
325# define __fortify_clang_warn_if_dest_too_small0(__dest, __len)
326#endif
327
328
329/* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
330 declared. */
331
332#if !__fortify_use_clang
333# define __glibc_fortify(f, __l, __s, __osz, ...) \
334 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
335 ? __ ## f ## _alias (__VA_ARGS__) \
336 : (__glibc_unsafe_len (__l, __s, __osz) \
337 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
338 : __ ## f ## _chk (__VA_ARGS__, __osz)))
339#else
340# define __glibc_fortify(f, __l, __s, __osz, ...) \
341 (__osz == (__SIZE_TYPE__) -1) \
342 ? __ ## f ## _alias (__VA_ARGS__) \
343 : __ ## f ## _chk (__VA_ARGS__, __osz)
344#endif
345
346/* Fortify function f, where object size argument passed to f is the number of
347 elements and not total size. */
348
349#if !__fortify_use_clang
350# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
351 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
352 ? __ ## f ## _alias (__VA_ARGS__) \
353 : (__glibc_unsafe_len (__l, __s, __osz) \
354 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
355 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
356# else
357# define __glibc_fortify_n(f, __l, __s, __osz, ...) \
358 (__osz == (__SIZE_TYPE__) -1) \
359 ? __ ## f ## _alias (__VA_ARGS__) \
360 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))
361#endif
362
363#endif /* __USE_FORTIFY_LEVEL > 0 */
364
365#if __GNUC_PREREQ (4,3)
366# define __warnattr(msg) __attribute__((__warning__ (msg)))
367# define __errordecl(name, msg) \
368 extern void name (void) __attribute__((__error__ (msg)))
369#else
370# define __warnattr(msg)
371# define __errordecl(name, msg) extern void name (void)
372#endif
373
374/* Support for flexible arrays.
375 Headers that should use flexible arrays only if they're "real"
376 (e.g. only if they won't affect sizeof()) should test
377 #if __glibc_c99_flexarr_available. */
378#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
379# define __flexarr []
380# define __glibc_c99_flexarr_available 1
381#elif __GNUC_PREREQ (2,97) || defined __clang__
382/* GCC 2.97 and clang support C99 flexible array members as an extension,
383 even when in C89 mode or compiling C++ (any version). */
384# define __flexarr []
385# define __glibc_c99_flexarr_available 1
386#elif defined __GNUC__
387/* Pre-2.97 GCC did not support C99 flexible arrays but did have
388 an equivalent extension with slightly different notation. */
389# define __flexarr [0]
390# define __glibc_c99_flexarr_available 1
391#else
392/* Some other non-C99 compiler. Approximate with [1]. */
393# define __flexarr [1]
394# define __glibc_c99_flexarr_available 0
395#endif
396
397
398/* __asm__ ("xyz") is used throughout the headers to rename functions
399 at the assembly language level. This is wrapped by the __REDIRECT
400 macro, in order to support compilers that can do this some other
401 way. When compilers don't support asm-names at all, we have to do
402 preprocessor tricks instead (which don't have exactly the right
403 semantics, but it's the best we can do).
404
405 Example:
406 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
407
408#if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
409
410# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
411# ifdef __cplusplus
412# define __REDIRECT_NTH(name, proto, alias) \
413 name proto __THROW __asm__ (__ASMNAME (#alias))
414# define __REDIRECT_NTHNL(name, proto, alias) \
415 name proto __THROWNL __asm__ (__ASMNAME (#alias))
416# else
417# define __REDIRECT_NTH(name, proto, alias) \
418 name proto __asm__ (__ASMNAME (#alias)) __THROW
419# define __REDIRECT_NTHNL(name, proto, alias) \
420 name proto __asm__ (__ASMNAME (#alias)) __THROWNL
421# endif
422# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
423# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
424
425#ifndef __REDIRECT_FORTIFY
426#define __REDIRECT_FORTIFY __REDIRECT
427#endif
428
429#ifndef __REDIRECT_FORTIFY_NTH
430#define __REDIRECT_FORTIFY_NTH __REDIRECT_NTH
431#endif
432
433/*
434#elif __SOME_OTHER_COMPILER__
435
436# define __REDIRECT(name, proto, alias) name proto; \
437 _Pragma("let " #name " = " #alias)
438*/
439#endif
440
441/* GCC and clang have various useful declarations that can be made with
442 the '__attribute__' syntax. All of the ways we use this do fine if
443 they are omitted for compilers that don't understand it. */
444#if !(defined __GNUC__ || defined __clang__)
445# define __attribute__(xyz) /* Ignore */
446#endif
447
448/* At some point during the gcc 2.96 development the `malloc' attribute
449 for functions was introduced. We don't want to use it unconditionally
450 (although this would be possible) since it generates warnings. */
451#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
452# define __attribute_malloc__ __attribute__ ((__malloc__))
453#else
454# define __attribute_malloc__ /* Ignore */
455#endif
456
457/* Tell the compiler which arguments to an allocation function
458 indicate the size of the allocation. */
459#if __GNUC_PREREQ (4, 3)
460# define __attribute_alloc_size__(params) \
461 __attribute__ ((__alloc_size__ params))
462#else
463# define __attribute_alloc_size__(params) /* Ignore. */
464#endif
465
466/* Tell the compiler which argument to an allocation function
467 indicates the alignment of the allocation. */
468#if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
469# define __attribute_alloc_align__(param) \
470 __attribute__ ((__alloc_align__ param))
471#else
472# define __attribute_alloc_align__(param) /* Ignore. */
473#endif
474
475/* At some point during the gcc 2.96 development the `pure' attribute
476 for functions was introduced. We don't want to use it unconditionally
477 (although this would be possible) since it generates warnings. */
478#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
479# define __attribute_pure__ __attribute__ ((__pure__))
480#else
481# define __attribute_pure__ /* Ignore */
482#endif
483
484/* This declaration tells the compiler that the value is constant. */
485#if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
486# define __attribute_const__ __attribute__ ((__const__))
487#else
488# define __attribute_const__ /* Ignore */
489#endif
490
491#if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
492# define __attribute_maybe_unused__ __attribute__ ((__unused__))
493#else
494# define __attribute_maybe_unused__ /* Ignore */
495#endif
496
497/* At some point during the gcc 3.1 development the `used' attribute
498 for functions was introduced. We don't want to use it unconditionally
499 (although this would be possible) since it generates warnings. */
500#if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
501# define __attribute_used__ __attribute__ ((__used__))
502# define __attribute_noinline__ __attribute__ ((__noinline__))
503#else
504# define __attribute_used__ __attribute__ ((__unused__))
505# define __attribute_noinline__ /* Ignore */
506#endif
507
508/* Since version 3.2, gcc allows marking deprecated functions. */
509#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
510# define __attribute_deprecated__ __attribute__ ((__deprecated__))
511#else
512# define __attribute_deprecated__ /* Ignore */
513#endif
514
515/* Since version 4.5, gcc also allows one to specify the message printed
516 when a deprecated function is used. clang claims to be gcc 4.2, but
517 may also support this feature. */
518#if __GNUC_PREREQ (4,5) \
519 || __glibc_has_extension (__attribute_deprecated_with_message__)
520# define __attribute_deprecated_msg__(msg) \
521 __attribute__ ((__deprecated__ (msg)))
522#else
523# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
524#endif
525
526/* At some point during the gcc 2.8 development the `format_arg' attribute
527 for functions was introduced. We don't want to use it unconditionally
528 (although this would be possible) since it generates warnings.
529 If several `format_arg' attributes are given for the same function, in
530 gcc-3.0 and older, all but the last one are ignored. In newer gccs,
531 all designated arguments are considered. */
532#if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
533# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
534#else
535# define __attribute_format_arg__(x) /* Ignore */
536#endif
537
538/* At some point during the gcc 2.97 development the `strfmon' format
539 attribute for functions was introduced. We don't want to use it
540 unconditionally (although this would be possible) since it
541 generates warnings. */
542#if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
543# define __attribute_format_strfmon__(a,b) \
544 __attribute__ ((__format__ (__strfmon__, a, b)))
545#else
546# define __attribute_format_strfmon__(a,b) /* Ignore */
547#endif
548
549/* The nonnull function attribute marks pointer parameters that
550 must not be NULL. This has the name __nonnull in glibc,
551 and __attribute_nonnull__ in files shared with Gnulib to avoid
552 collision with a different __nonnull in DragonFlyBSD 5.9. */
553#ifndef __attribute_nonnull__
554# if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
555# define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
556# else
557# define __attribute_nonnull__(params)
558# endif
559#endif
560#ifndef __nonnull
561# define __nonnull(params) __attribute_nonnull__ (params)
562#endif
563
564/* The returns_nonnull function attribute marks the return type of the function
565 as always being non-null. */
566#ifndef __returns_nonnull
567# if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
568# define __returns_nonnull __attribute__ ((__returns_nonnull__))
569# else
570# define __returns_nonnull
571# endif
572#endif
573
574/* If fortification mode, we warn about unused results of certain
575 function calls which can lead to problems. */
576#if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
577# define __attribute_warn_unused_result__ \
578 __attribute__ ((__warn_unused_result__))
579# if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
580# define __wur __attribute_warn_unused_result__
581# endif
582#else
583# define __attribute_warn_unused_result__ /* empty */
584#endif
585#ifndef __wur
586# define __wur /* Ignore */
587#endif
588
589/* Forces a function to be always inlined. */
590#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
591/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
592 it conflicts with this definition. Therefore undefine it first to
593 allow either header to be included first. */
594# undef __always_inline
595# define __always_inline __inline __attribute__ ((__always_inline__))
596#else
597# undef __always_inline
598# define __always_inline __inline
599#endif
600
601/* Associate error messages with the source location of the call site rather
602 than with the source location inside the function. */
603#if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
604# define __attribute_artificial__ __attribute__ ((__artificial__))
605#else
606# define __attribute_artificial__ /* Ignore */
607#endif
608
609/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
610 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
611 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
612 older than 4.3 may define these macros and still not guarantee GNU inlining
613 semantics.
614
615 clang++ identifies itself as gcc-4.2, but has support for GNU inlining
616 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
617 __GNUC_GNU_INLINE__ macro definitions. */
618#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
619 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
620 || defined __GNUC_GNU_INLINE__)))
621# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
622# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
623# define __extern_always_inline \
624 extern __always_inline __attribute__ ((__gnu_inline__))
625# else
626# define __extern_inline extern __inline
627# define __extern_always_inline extern __always_inline
628# endif
629#endif
630
631#ifdef __extern_always_inline
632# define __fortify_function __extern_always_inline __attribute_artificial__
633#endif
634
635/* GCC 4.3 and above allow passing all anonymous arguments of an
636 __extern_always_inline function to some other vararg function. */
637#if __GNUC_PREREQ (4,3)
638# define __va_arg_pack() __builtin_va_arg_pack ()
639# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
640#endif
641
642/* It is possible to compile containing GCC extensions even if GCC is
643 run in pedantic mode if the uses are carefully marked using the
644 `__extension__' keyword. But this is not generally available before
645 version 2.8. */
646#if !(__GNUC_PREREQ (2,8) || defined __clang__)
647# define __extension__ /* Ignore */
648#endif
649
650/* __restrict is known in EGCS 1.2 and above, and in clang.
651 It works also in C++ mode (outside of arrays), but only when spelled
652 as '__restrict', not 'restrict'. */
653#if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
654# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
655# define __restrict restrict
656# else
657# define __restrict /* Ignore */
658# endif
659#endif
660
661/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
662 array_name[restrict]
663 GCC 3.1 and clang support this.
664 This syntax is not usable in C++ mode. */
665#if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
666# define __restrict_arr __restrict
667#else
668# ifdef __GNUC__
669# define __restrict_arr /* Not supported in old GCC. */
670# else
671# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
672# define __restrict_arr restrict
673# else
674/* Some other non-C99 compiler. */
675# define __restrict_arr /* Not supported. */
676# endif
677# endif
678#endif
679
680#if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
681# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
682# define __glibc_likely(cond) __builtin_expect ((cond), 1)
683#else
684# define __glibc_unlikely(cond) (cond)
685# define __glibc_likely(cond) (cond)
686#endif
687
688#if (!defined _Noreturn \
689 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
690 && !(__GNUC_PREREQ (4,7) \
691 || (3 < __clang_major__ + (5 <= __clang_minor__))))
692# if __GNUC_PREREQ (2,8)
693# define _Noreturn __attribute__ ((__noreturn__))
694# else
695# define _Noreturn
696# endif
697#endif
698
699#if __GNUC_PREREQ (8, 0)
700/* Describes a char array whose address can safely be passed as the first
701 argument to strncpy and strncat, as the char array is not necessarily
702 a NUL-terminated string. */
703# define __attribute_nonstring__ __attribute__ ((__nonstring__))
704#else
705# define __attribute_nonstring__
706#endif
707
708/* Undefine (also defined in libc-symbols.h). */
709#undef __attribute_copy__
710#if __GNUC_PREREQ (9, 0)
711/* Copies attributes from the declaration or type referenced by
712 the argument. */
713# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
714#else
715# define __attribute_copy__(arg)
716#endif
717
718#if (!defined _Static_assert && !defined __cplusplus \
719 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
720 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
721 || defined __STRICT_ANSI__))
722# define _Static_assert(expr, diagnostic) \
723 extern int (*__Static_assert_function (void)) \
724 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
725#endif
726
727/* Gnulib avoids including these, as they don't work on non-glibc or
728 older glibc platforms. */
729#ifndef __GNULIB_CDEFS
730# include <bits/wordsize.h>
731# include <bits/long-double.h>
732#endif
733
734#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
735# ifdef __REDIRECT
736
737/* Alias name defined automatically. */
738# define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
739# define __LDBL_REDIR_DECL(name) \
740 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
741# define __REDIRECT_LDBL(name, proto, alias) \
742 name proto __asm (__ASMNAME ("__" #alias "ieee128"))
743
744/* Alias name defined automatically, with leading underscores. */
745# define __LDBL_REDIR2_DECL(name) \
746 extern __typeof (__##name) __##name \
747 __asm (__ASMNAME ("__" #name "ieee128"));
748
749/* Alias name defined manually. */
750# define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
751# define __LDBL_REDIR1_DECL(name, alias) \
752 extern __typeof (name) name __asm (__ASMNAME (#alias));
753
754# define __LDBL_REDIR1_NTH(name, proto, alias) \
755 __REDIRECT_NTH (name, proto, alias)
756# define __REDIRECT_NTH_LDBL(name, proto, alias) \
757 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
758
759/* Unused. */
760# define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
761
762# else
763_Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
764# endif
765#elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
766# define __LDBL_COMPAT 1
767# ifdef __REDIRECT
768# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
769# define __LDBL_REDIR(name, proto) \
770 __LDBL_REDIR1 (name, proto, __nldbl_##name)
771# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
772# define __LDBL_REDIR_NTH(name, proto) \
773 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
774# define __LDBL_REDIR2_DECL(name) \
775 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
776# define __LDBL_REDIR1_DECL(name, alias) \
777 extern __typeof (name) name __asm (__ASMNAME (#alias));
778# define __LDBL_REDIR_DECL(name) \
779 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
780# define __REDIRECT_LDBL(name, proto, alias) \
781 __LDBL_REDIR1 (name, proto, __nldbl_##alias)
782# define __REDIRECT_NTH_LDBL(name, proto, alias) \
783 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
784# endif
785#endif
786#if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
787 || !defined __REDIRECT
788# define __LDBL_REDIR1(name, proto, alias) name proto
789# define __LDBL_REDIR(name, proto) name proto
790# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
791# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
792# define __LDBL_REDIR2_DECL(name)
793# define __LDBL_REDIR_DECL(name)
794# ifdef __REDIRECT
795# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
796# define __REDIRECT_NTH_LDBL(name, proto, alias) \
797 __REDIRECT_NTH (name, proto, alias)
798# endif
799#endif
800
801/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
802 intended for use in preprocessor macros.
803
804 Note: MESSAGE must be a _single_ string; concatenation of string
805 literals is not supported. */
806#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
807# define __glibc_macro_warning1(message) _Pragma (#message)
808# define __glibc_macro_warning(message) \
809 __glibc_macro_warning1 (GCC warning message)
810#else
811# define __glibc_macro_warning(msg)
812#endif
813
814/* Generic selection (ISO C11) is a C-only feature, available in GCC
815 since version 4.9. Previous versions do not provide generic
816 selection, even though they might set __STDC_VERSION__ to 201112L,
817 when in -std=c11 mode. Thus, we must check for !defined __GNUC__
818 when testing __STDC_VERSION__ for generic selection support.
819 On the other hand, Clang also defines __GNUC__, so a clang-specific
820 check is required to enable the use of generic selection. */
821#if !defined __cplusplus \
822 && (__GNUC_PREREQ (4, 9) \
823 || __glibc_has_extension (c_generic_selections) \
824 || (!defined __GNUC__ && defined __STDC_VERSION__ \
825 && __STDC_VERSION__ >= 201112L))
826# define __HAVE_GENERIC_SELECTION 1
827#else
828# define __HAVE_GENERIC_SELECTION 0
829#endif
830
831#if __GNUC_PREREQ (10, 0)
832/* Designates a 1-based positional argument ref-index of pointer type
833 that can be used to access size-index elements of the pointed-to
834 array according to access mode, or at least one element when
835 size-index is not provided:
836 access (access-mode, <ref-index> [, <size-index>]) */
837# define __attr_access(x) __attribute__ ((__access__ x))
838/* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
839 use the access attribute to get object sizes from function definition
840 arguments, so we can't use them on functions we fortify. Drop the access
841 attribute for such functions. */
842# if __USE_FORTIFY_LEVEL == 3
843# define __fortified_attr_access(a, o, s)
844# else
845# define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
846# endif
847# if __GNUC_PREREQ (11, 0)
848# define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
849# else
850# define __attr_access_none(argno)
851# endif
852#else
853# define __fortified_attr_access(a, o, s)
854# define __attr_access(x)
855# define __attr_access_none(argno)
856#endif
857
858#if __GNUC_PREREQ (11, 0)
859/* Designates dealloc as a function to call to deallocate objects
860 allocated by the declared function. */
861# define __attr_dealloc(dealloc, argno) \
862 __attribute__ ((__malloc__ (dealloc, argno)))
863# define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
864#else
865# define __attr_dealloc(dealloc, argno)
866# define __attr_dealloc_free
867#endif
868
869/* Specify that a function such as setjmp or vfork may return
870 twice. */
871#if __GNUC_PREREQ (4, 1)
872# define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
873#else
874# define __attribute_returns_twice__ /* Ignore. */
875#endif
876
877/* Mark struct types as aliasable. Restricted to compilers that
878 support forward declarations of structs in the presence of the
879 attribute. */
880#if __GNUC_PREREQ (7, 1) || defined __clang__
881# define __attribute_struct_may_alias__ __attribute__ ((__may_alias__))
882#else
883# define __attribute_struct_may_alias__
884#endif
885
886#endif /* sys/cdefs.h */
887