1/* Copyright (C) 1992-2022 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__
31# error "You need a ISO 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#else /* Not GCC or clang. */
102
103# if (defined __cplusplus \
104 || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
105# define __inline inline
106# else
107# define __inline /* No inline functions. */
108# endif
109
110# define __THROW
111# define __THROWNL
112# define __NTH(fct) fct
113
114#endif /* GCC || clang. */
115
116/* These two macros are not used in glibc anymore. They are kept here
117 only because some other projects expect the macros to be defined. */
118#define __P(args) args
119#define __PMT(args) args
120
121/* For these things, GCC behaves the ANSI way normally,
122 and the non-ANSI way under -traditional. */
123
124#define __CONCAT(x,y) x ## y
125#define __STRING(x) #x
126
127/* This is not a typedef so `const __ptr_t' does the right thing. */
128#define __ptr_t void *
129
130
131/* C++ needs to know that types and declarations are C, not C++. */
132#ifdef __cplusplus
133# define __BEGIN_DECLS extern "C" {
134# define __END_DECLS }
135#else
136# define __BEGIN_DECLS
137# define __END_DECLS
138#endif
139
140
141/* Fortify support. */
142#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
143#define __bos0(ptr) __builtin_object_size (ptr, 0)
144
145/* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available. */
146#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
147 || __GNUC_PREREQ (12, 0))
148# define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
149# define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
150#else
151# define __glibc_objsize0(__o) __bos0 (__o)
152# define __glibc_objsize(__o) __bos (__o)
153#endif
154
155/* Compile time conditions to choose between the regular, _chk and _chk_warn
156 variants. These conditions should get evaluated to constant and optimized
157 away. */
158
159#define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
160#define __glibc_unsigned_or_positive(__l) \
161 ((__typeof (__l)) 0 < (__typeof (__l)) -1 \
162 || (__builtin_constant_p (__l) && (__l) > 0))
163
164/* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
165 condition can be folded to a constant and if it is true, or unknown (-1) */
166#define __glibc_safe_or_unknown_len(__l, __s, __osz) \
167 ((__builtin_constant_p (__osz) && (__osz) == (__SIZE_TYPE__) -1) \
168 || (__glibc_unsigned_or_positive (__l) \
169 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
170 (__s), (__osz))) \
171 && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), (__s), (__osz))))
172
173/* Conversely, we know at compile time that the length is unsafe if the
174 __L * __S <= __OBJSZ condition can be folded to a constant and if it is
175 false. */
176#define __glibc_unsafe_len(__l, __s, __osz) \
177 (__glibc_unsigned_or_positive (__l) \
178 && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), \
179 __s, __osz)) \
180 && !__glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
181
182/* Fortify function f. __f_alias, __f_chk and __f_chk_warn must be
183 declared. */
184
185#define __glibc_fortify(f, __l, __s, __osz, ...) \
186 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
187 ? __ ## f ## _alias (__VA_ARGS__) \
188 : (__glibc_unsafe_len (__l, __s, __osz) \
189 ? __ ## f ## _chk_warn (__VA_ARGS__, __osz) \
190 : __ ## f ## _chk (__VA_ARGS__, __osz))) \
191
192/* Fortify function f, where object size argument passed to f is the number of
193 elements and not total size. */
194
195#define __glibc_fortify_n(f, __l, __s, __osz, ...) \
196 (__glibc_safe_or_unknown_len (__l, __s, __osz) \
197 ? __ ## f ## _alias (__VA_ARGS__) \
198 : (__glibc_unsafe_len (__l, __s, __osz) \
199 ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s)) \
200 : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s)))) \
201
202#if __GNUC_PREREQ (4,3)
203# define __warnattr(msg) __attribute__((__warning__ (msg)))
204# define __errordecl(name, msg) \
205 extern void name (void) __attribute__((__error__ (msg)))
206#else
207# define __warnattr(msg)
208# define __errordecl(name, msg) extern void name (void)
209#endif
210
211/* Support for flexible arrays.
212 Headers that should use flexible arrays only if they're "real"
213 (e.g. only if they won't affect sizeof()) should test
214 #if __glibc_c99_flexarr_available. */
215#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
216# define __flexarr []
217# define __glibc_c99_flexarr_available 1
218#elif __GNUC_PREREQ (2,97) || defined __clang__
219/* GCC 2.97 and clang support C99 flexible array members as an extension,
220 even when in C89 mode or compiling C++ (any version). */
221# define __flexarr []
222# define __glibc_c99_flexarr_available 1
223#elif defined __GNUC__
224/* Pre-2.97 GCC did not support C99 flexible arrays but did have
225 an equivalent extension with slightly different notation. */
226# define __flexarr [0]
227# define __glibc_c99_flexarr_available 1
228#else
229/* Some other non-C99 compiler. Approximate with [1]. */
230# define __flexarr [1]
231# define __glibc_c99_flexarr_available 0
232#endif
233
234
235/* __asm__ ("xyz") is used throughout the headers to rename functions
236 at the assembly language level. This is wrapped by the __REDIRECT
237 macro, in order to support compilers that can do this some other
238 way. When compilers don't support asm-names at all, we have to do
239 preprocessor tricks instead (which don't have exactly the right
240 semantics, but it's the best we can do).
241
242 Example:
243 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
244
245#if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
246
247# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
248# ifdef __cplusplus
249# define __REDIRECT_NTH(name, proto, alias) \
250 name proto __THROW __asm__ (__ASMNAME (#alias))
251# define __REDIRECT_NTHNL(name, proto, alias) \
252 name proto __THROWNL __asm__ (__ASMNAME (#alias))
253# else
254# define __REDIRECT_NTH(name, proto, alias) \
255 name proto __asm__ (__ASMNAME (#alias)) __THROW
256# define __REDIRECT_NTHNL(name, proto, alias) \
257 name proto __asm__ (__ASMNAME (#alias)) __THROWNL
258# endif
259# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
260# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
261
262/*
263#elif __SOME_OTHER_COMPILER__
264
265# define __REDIRECT(name, proto, alias) name proto; \
266 _Pragma("let " #name " = " #alias)
267*/
268#endif
269
270/* GCC and clang have various useful declarations that can be made with
271 the '__attribute__' syntax. All of the ways we use this do fine if
272 they are omitted for compilers that don't understand it. */
273#if !(defined __GNUC__ || defined __clang__)
274# define __attribute__(xyz) /* Ignore */
275#endif
276
277/* At some point during the gcc 2.96 development the `malloc' attribute
278 for functions was introduced. We don't want to use it unconditionally
279 (although this would be possible) since it generates warnings. */
280#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
281# define __attribute_malloc__ __attribute__ ((__malloc__))
282#else
283# define __attribute_malloc__ /* Ignore */
284#endif
285
286/* Tell the compiler which arguments to an allocation function
287 indicate the size of the allocation. */
288#if __GNUC_PREREQ (4, 3)
289# define __attribute_alloc_size__(params) \
290 __attribute__ ((__alloc_size__ params))
291#else
292# define __attribute_alloc_size__(params) /* Ignore. */
293#endif
294
295/* Tell the compiler which argument to an allocation function
296 indicates the alignment of the allocation. */
297#if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
298# define __attribute_alloc_align__(param) \
299 __attribute__ ((__alloc_align__ param))
300#else
301# define __attribute_alloc_align__(param) /* Ignore. */
302#endif
303
304/* At some point during the gcc 2.96 development the `pure' attribute
305 for functions was introduced. We don't want to use it unconditionally
306 (although this would be possible) since it generates warnings. */
307#if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
308# define __attribute_pure__ __attribute__ ((__pure__))
309#else
310# define __attribute_pure__ /* Ignore */
311#endif
312
313/* This declaration tells the compiler that the value is constant. */
314#if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
315# define __attribute_const__ __attribute__ ((__const__))
316#else
317# define __attribute_const__ /* Ignore */
318#endif
319
320#if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
321# define __attribute_maybe_unused__ __attribute__ ((__unused__))
322#else
323# define __attribute_maybe_unused__ /* Ignore */
324#endif
325
326/* At some point during the gcc 3.1 development the `used' attribute
327 for functions was introduced. We don't want to use it unconditionally
328 (although this would be possible) since it generates warnings. */
329#if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
330# define __attribute_used__ __attribute__ ((__used__))
331# define __attribute_noinline__ __attribute__ ((__noinline__))
332#else
333# define __attribute_used__ __attribute__ ((__unused__))
334# define __attribute_noinline__ /* Ignore */
335#endif
336
337/* Since version 3.2, gcc allows marking deprecated functions. */
338#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
339# define __attribute_deprecated__ __attribute__ ((__deprecated__))
340#else
341# define __attribute_deprecated__ /* Ignore */
342#endif
343
344/* Since version 4.5, gcc also allows one to specify the message printed
345 when a deprecated function is used. clang claims to be gcc 4.2, but
346 may also support this feature. */
347#if __GNUC_PREREQ (4,5) \
348 || __glibc_has_extension (__attribute_deprecated_with_message__)
349# define __attribute_deprecated_msg__(msg) \
350 __attribute__ ((__deprecated__ (msg)))
351#else
352# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
353#endif
354
355/* At some point during the gcc 2.8 development the `format_arg' attribute
356 for functions was introduced. We don't want to use it unconditionally
357 (although this would be possible) since it generates warnings.
358 If several `format_arg' attributes are given for the same function, in
359 gcc-3.0 and older, all but the last one are ignored. In newer gccs,
360 all designated arguments are considered. */
361#if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
362# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
363#else
364# define __attribute_format_arg__(x) /* Ignore */
365#endif
366
367/* At some point during the gcc 2.97 development the `strfmon' format
368 attribute for functions was introduced. We don't want to use it
369 unconditionally (although this would be possible) since it
370 generates warnings. */
371#if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
372# define __attribute_format_strfmon__(a,b) \
373 __attribute__ ((__format__ (__strfmon__, a, b)))
374#else
375# define __attribute_format_strfmon__(a,b) /* Ignore */
376#endif
377
378/* The nonnull function attribute marks pointer parameters that
379 must not be NULL. This has the name __nonnull in glibc,
380 and __attribute_nonnull__ in files shared with Gnulib to avoid
381 collision with a different __nonnull in DragonFlyBSD 5.9. */
382#ifndef __attribute_nonnull__
383# if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
384# define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
385# else
386# define __attribute_nonnull__(params)
387# endif
388#endif
389#ifndef __nonnull
390# define __nonnull(params) __attribute_nonnull__ (params)
391#endif
392
393/* The returns_nonnull function attribute marks the return type of the function
394 as always being non-null. */
395#ifndef __returns_nonnull
396# if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
397# define __returns_nonnull __attribute__ ((__returns_nonnull__))
398# else
399# define __returns_nonnull
400# endif
401#endif
402
403/* If fortification mode, we warn about unused results of certain
404 function calls which can lead to problems. */
405#if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
406# define __attribute_warn_unused_result__ \
407 __attribute__ ((__warn_unused_result__))
408# if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
409# define __wur __attribute_warn_unused_result__
410# endif
411#else
412# define __attribute_warn_unused_result__ /* empty */
413#endif
414#ifndef __wur
415# define __wur /* Ignore */
416#endif
417
418/* Forces a function to be always inlined. */
419#if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
420/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
421 it conflicts with this definition. Therefore undefine it first to
422 allow either header to be included first. */
423# undef __always_inline
424# define __always_inline __inline __attribute__ ((__always_inline__))
425#else
426# undef __always_inline
427# define __always_inline __inline
428#endif
429
430/* Associate error messages with the source location of the call site rather
431 than with the source location inside the function. */
432#if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
433# define __attribute_artificial__ __attribute__ ((__artificial__))
434#else
435# define __attribute_artificial__ /* Ignore */
436#endif
437
438/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
439 inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
440 or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
441 older than 4.3 may define these macros and still not guarantee GNU inlining
442 semantics.
443
444 clang++ identifies itself as gcc-4.2, but has support for GNU inlining
445 semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
446 __GNUC_GNU_INLINE__ macro definitions. */
447#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
448 || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
449 || defined __GNUC_GNU_INLINE__)))
450# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
451# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
452# define __extern_always_inline \
453 extern __always_inline __attribute__ ((__gnu_inline__))
454# else
455# define __extern_inline extern __inline
456# define __extern_always_inline extern __always_inline
457# endif
458#endif
459
460#ifdef __extern_always_inline
461# define __fortify_function __extern_always_inline __attribute_artificial__
462#endif
463
464/* GCC 4.3 and above allow passing all anonymous arguments of an
465 __extern_always_inline function to some other vararg function. */
466#if __GNUC_PREREQ (4,3)
467# define __va_arg_pack() __builtin_va_arg_pack ()
468# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
469#endif
470
471/* It is possible to compile containing GCC extensions even if GCC is
472 run in pedantic mode if the uses are carefully marked using the
473 `__extension__' keyword. But this is not generally available before
474 version 2.8. */
475#if !(__GNUC_PREREQ (2,8) || defined __clang__)
476# define __extension__ /* Ignore */
477#endif
478
479/* __restrict is known in EGCS 1.2 and above, and in clang.
480 It works also in C++ mode (outside of arrays), but only when spelled
481 as '__restrict', not 'restrict'. */
482#if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
483# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
484# define __restrict restrict
485# else
486# define __restrict /* Ignore */
487# endif
488#endif
489
490/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
491 array_name[restrict]
492 GCC 3.1 and clang support this.
493 This syntax is not usable in C++ mode. */
494#if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
495# define __restrict_arr __restrict
496#else
497# ifdef __GNUC__
498# define __restrict_arr /* Not supported in old GCC. */
499# else
500# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
501# define __restrict_arr restrict
502# else
503/* Some other non-C99 compiler. */
504# define __restrict_arr /* Not supported. */
505# endif
506# endif
507#endif
508
509#if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
510# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
511# define __glibc_likely(cond) __builtin_expect ((cond), 1)
512#else
513# define __glibc_unlikely(cond) (cond)
514# define __glibc_likely(cond) (cond)
515#endif
516
517#if (!defined _Noreturn \
518 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
519 && !(__GNUC_PREREQ (4,7) \
520 || (3 < __clang_major__ + (5 <= __clang_minor__))))
521# if __GNUC_PREREQ (2,8)
522# define _Noreturn __attribute__ ((__noreturn__))
523# else
524# define _Noreturn
525# endif
526#endif
527
528#if __GNUC_PREREQ (8, 0)
529/* Describes a char array whose address can safely be passed as the first
530 argument to strncpy and strncat, as the char array is not necessarily
531 a NUL-terminated string. */
532# define __attribute_nonstring__ __attribute__ ((__nonstring__))
533#else
534# define __attribute_nonstring__
535#endif
536
537/* Undefine (also defined in libc-symbols.h). */
538#undef __attribute_copy__
539#if __GNUC_PREREQ (9, 0)
540/* Copies attributes from the declaration or type referenced by
541 the argument. */
542# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
543#else
544# define __attribute_copy__(arg)
545#endif
546
547#if (!defined _Static_assert && !defined __cplusplus \
548 && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
549 && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
550 || defined __STRICT_ANSI__))
551# define _Static_assert(expr, diagnostic) \
552 extern int (*__Static_assert_function (void)) \
553 [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
554#endif
555
556/* Gnulib avoids including these, as they don't work on non-glibc or
557 older glibc platforms. */
558#ifndef __GNULIB_CDEFS
559# include <bits/wordsize.h>
560# include <bits/long-double.h>
561#endif
562
563#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
564# ifdef __REDIRECT
565
566/* Alias name defined automatically. */
567# define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
568# define __LDBL_REDIR_DECL(name) \
569 extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
570
571/* Alias name defined automatically, with leading underscores. */
572# define __LDBL_REDIR2_DECL(name) \
573 extern __typeof (__##name) __##name \
574 __asm (__ASMNAME ("__" #name "ieee128"));
575
576/* Alias name defined manually. */
577# define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
578# define __LDBL_REDIR1_DECL(name, alias) \
579 extern __typeof (name) name __asm (__ASMNAME (#alias));
580
581# define __LDBL_REDIR1_NTH(name, proto, alias) \
582 __REDIRECT_NTH (name, proto, alias)
583# define __REDIRECT_NTH_LDBL(name, proto, alias) \
584 __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
585
586/* Unused. */
587# define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
588# define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
589
590# else
591_Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
592# endif
593#elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
594# define __LDBL_COMPAT 1
595# ifdef __REDIRECT
596# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
597# define __LDBL_REDIR(name, proto) \
598 __LDBL_REDIR1 (name, proto, __nldbl_##name)
599# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
600# define __LDBL_REDIR_NTH(name, proto) \
601 __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
602# define __LDBL_REDIR2_DECL(name) \
603 extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
604# define __LDBL_REDIR1_DECL(name, alias) \
605 extern __typeof (name) name __asm (__ASMNAME (#alias));
606# define __LDBL_REDIR_DECL(name) \
607 extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
608# define __REDIRECT_LDBL(name, proto, alias) \
609 __LDBL_REDIR1 (name, proto, __nldbl_##alias)
610# define __REDIRECT_NTH_LDBL(name, proto, alias) \
611 __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
612# endif
613#endif
614#if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
615 || !defined __REDIRECT
616# define __LDBL_REDIR1(name, proto, alias) name proto
617# define __LDBL_REDIR(name, proto) name proto
618# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
619# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
620# define __LDBL_REDIR2_DECL(name)
621# define __LDBL_REDIR_DECL(name)
622# ifdef __REDIRECT
623# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
624# define __REDIRECT_NTH_LDBL(name, proto, alias) \
625 __REDIRECT_NTH (name, proto, alias)
626# endif
627#endif
628
629/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
630 intended for use in preprocessor macros.
631
632 Note: MESSAGE must be a _single_ string; concatenation of string
633 literals is not supported. */
634#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
635# define __glibc_macro_warning1(message) _Pragma (#message)
636# define __glibc_macro_warning(message) \
637 __glibc_macro_warning1 (GCC warning message)
638#else
639# define __glibc_macro_warning(msg)
640#endif
641
642/* Generic selection (ISO C11) is a C-only feature, available in GCC
643 since version 4.9. Previous versions do not provide generic
644 selection, even though they might set __STDC_VERSION__ to 201112L,
645 when in -std=c11 mode. Thus, we must check for !defined __GNUC__
646 when testing __STDC_VERSION__ for generic selection support.
647 On the other hand, Clang also defines __GNUC__, so a clang-specific
648 check is required to enable the use of generic selection. */
649#if !defined __cplusplus \
650 && (__GNUC_PREREQ (4, 9) \
651 || __glibc_has_extension (c_generic_selections) \
652 || (!defined __GNUC__ && defined __STDC_VERSION__ \
653 && __STDC_VERSION__ >= 201112L))
654# define __HAVE_GENERIC_SELECTION 1
655#else
656# define __HAVE_GENERIC_SELECTION 0
657#endif
658
659#if __GNUC_PREREQ (10, 0)
660/* Designates a 1-based positional argument ref-index of pointer type
661 that can be used to access size-index elements of the pointed-to
662 array according to access mode, or at least one element when
663 size-index is not provided:
664 access (access-mode, <ref-index> [, <size-index>]) */
665# define __attr_access(x) __attribute__ ((__access__ x))
666/* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
667 use the access attribute to get object sizes from function definition
668 arguments, so we can't use them on functions we fortify. Drop the object
669 size hints for such functions. */
670# if __USE_FORTIFY_LEVEL == 3
671# define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o)))
672# else
673# define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
674# endif
675# if __GNUC_PREREQ (11, 0)
676# define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
677# else
678# define __attr_access_none(argno)
679# endif
680#else
681# define __fortified_attr_access(a, o, s)
682# define __attr_access(x)
683# define __attr_access_none(argno)
684#endif
685
686#if __GNUC_PREREQ (11, 0)
687/* Designates dealloc as a function to call to deallocate objects
688 allocated by the declared function. */
689# define __attr_dealloc(dealloc, argno) \
690 __attribute__ ((__malloc__ (dealloc, argno)))
691# define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
692#else
693# define __attr_dealloc(dealloc, argno)
694# define __attr_dealloc_free
695#endif
696
697/* Specify that a function such as setjmp or vfork may return
698 twice. */
699#if __GNUC_PREREQ (4, 1)
700# define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
701#else
702# define __attribute_returns_twice__ /* Ignore. */
703#endif
704
705#endif /* sys/cdefs.h */
706

source code of glibc/misc/sys/cdefs.h