1 /* Copyright (C) 1992-2021 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #ifndef	_SYS_CDEFS_H
19 #define	_SYS_CDEFS_H	1
20 
21 /* We are almost always included from features.h. */
22 #ifndef _FEATURES_H
23 # include <features.h>
24 #endif
25 
26 /* The GNU libc does not support any K&R compilers or the traditional mode
27    of ISO C compilers anymore.  Check for some of the combinations not
28    supported anymore.  */
29 #if defined __GNUC__ && !defined __STDC__
30 # error "You need a ISO C conforming compiler to use the glibc headers"
31 #endif
32 
33 /* Some user header file might have defined this before.  */
34 #undef	__P
35 #undef	__PMT
36 
37 /* Compilers that lack __has_attribute may object to
38        #if defined __has_attribute && __has_attribute (...)
39    even though they do not need to evaluate the right-hand side of the &&.
40    Similarly for __has_builtin, etc.  */
41 #if (defined __has_attribute \
42      && (!defined __clang_minor__ \
43          || 3 < __clang_major__ + (5 <= __clang_minor__)))
44 # define __glibc_has_attribute(attr) __has_attribute (attr)
45 #else
46 # define __glibc_has_attribute(attr) 0
47 #endif
48 #ifdef __has_builtin
49 # define __glibc_has_builtin(name) __has_builtin (name)
50 #else
51 # define __glibc_has_builtin(name) 0
52 #endif
53 #ifdef __has_extension
54 # define __glibc_has_extension(ext) __has_extension (ext)
55 #else
56 # define __glibc_has_extension(ext) 0
57 #endif
58 
59 #if defined __GNUC__ || defined __clang__
60 
61 /* All functions, except those with callbacks or those that
62    synchronize memory, are leaf functions.  */
63 # if __GNUC_PREREQ (4, 6) && !defined _LIBC
64 #  define __LEAF , __leaf__
65 #  define __LEAF_ATTR __attribute__ ((__leaf__))
66 # else
67 #  define __LEAF
68 #  define __LEAF_ATTR
69 # endif
70 
71 /* GCC can always grok prototypes.  For C++ programs we add throw()
72    to help it optimize the function calls.  But this only works with
73    gcc 2.8.x and egcs.  For gcc 3.4 and up we even mark C functions
74    as non-throwing using a function attribute since programs can use
75    the -fexceptions options for C code as well.  */
76 # if !defined __cplusplus \
77      && (__GNUC_PREREQ (3, 4) || __glibc_has_attribute (__nothrow__))
78 #  define __THROW	__attribute__ ((__nothrow__ __LEAF))
79 #  define __THROWNL	__attribute__ ((__nothrow__))
80 #  define __NTH(fct)	__attribute__ ((__nothrow__ __LEAF)) fct
81 #  define __NTHNL(fct)  __attribute__ ((__nothrow__)) fct
82 # else
83 #  if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4)
84 #   if __cplusplus >= 201103L
85 #    define __THROW	noexcept (true)
86 #   else
87 #    define __THROW	throw ()
88 #   endif
89 #   define __THROWNL	__THROW
90 #   define __NTH(fct)	__LEAF_ATTR fct __THROW
91 #   define __NTHNL(fct) fct __THROW
92 #  else
93 #   define __THROW
94 #   define __THROWNL
95 #   define __NTH(fct)	fct
96 #   define __NTHNL(fct) fct
97 #  endif
98 # endif
99 
100 #else	/* Not GCC or clang.  */
101 
102 # if (defined __cplusplus						\
103       || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
104 #  define __inline	inline
105 # else
106 #  define __inline		/* No inline functions.  */
107 # endif
108 
109 # define __THROW
110 # define __THROWNL
111 # define __NTH(fct)	fct
112 
113 #endif	/* GCC || clang.  */
114 
115 /* These two macros are not used in glibc anymore.  They are kept here
116    only because some other projects expect the macros to be defined.  */
117 #define __P(args)	args
118 #define __PMT(args)	args
119 
120 /* For these things, GCC behaves the ANSI way normally,
121    and the non-ANSI way under -traditional.  */
122 
123 #define __CONCAT(x,y)	x ## y
124 #define __STRING(x)	#x
125 
126 /* This is not a typedef so `const __ptr_t' does the right thing.  */
127 #define __ptr_t void *
128 
129 
130 /* C++ needs to know that types and declarations are C, not C++.  */
131 #ifdef	__cplusplus
132 # define __BEGIN_DECLS	extern "C" {
133 # define __END_DECLS	}
134 #else
135 # define __BEGIN_DECLS
136 # define __END_DECLS
137 #endif
138 
139 
140 /* Fortify support.  */
141 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
142 #define __bos0(ptr) __builtin_object_size (ptr, 0)
143 
144 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available.  */
145 #if __USE_FORTIFY_LEVEL == 3 && __glibc_clang_prereq (9, 0)
146 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
147 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
148 #else
149 # define __glibc_objsize0(__o) __bos0 (__o)
150 # define __glibc_objsize(__o) __bos (__o)
151 #endif
152 
153 #if __GNUC_PREREQ (4,3)
154 # define __warnattr(msg) __attribute__((__warning__ (msg)))
155 # define __errordecl(name, msg) \
156   extern void name (void) __attribute__((__error__ (msg)))
157 #else
158 # define __warnattr(msg)
159 # define __errordecl(name, msg) extern void name (void)
160 #endif
161 
162 /* Support for flexible arrays.
163    Headers that should use flexible arrays only if they're "real"
164    (e.g. only if they won't affect sizeof()) should test
165    #if __glibc_c99_flexarr_available.  */
166 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
167 # define __flexarr	[]
168 # define __glibc_c99_flexarr_available 1
169 #elif __GNUC_PREREQ (2,97) || defined __clang__
170 /* GCC 2.97 and clang support C99 flexible array members as an extension,
171    even when in C89 mode or compiling C++ (any version).  */
172 # define __flexarr	[]
173 # define __glibc_c99_flexarr_available 1
174 #elif defined __GNUC__
175 /* Pre-2.97 GCC did not support C99 flexible arrays but did have
176    an equivalent extension with slightly different notation.  */
177 # define __flexarr	[0]
178 # define __glibc_c99_flexarr_available 1
179 #else
180 /* Some other non-C99 compiler.  Approximate with [1].  */
181 # define __flexarr	[1]
182 # define __glibc_c99_flexarr_available 0
183 #endif
184 
185 
186 /* __asm__ ("xyz") is used throughout the headers to rename functions
187    at the assembly language level.  This is wrapped by the __REDIRECT
188    macro, in order to support compilers that can do this some other
189    way.  When compilers don't support asm-names at all, we have to do
190    preprocessor tricks instead (which don't have exactly the right
191    semantics, but it's the best we can do).
192 
193    Example:
194    int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
195 
196 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
197 
198 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
199 # ifdef __cplusplus
200 #  define __REDIRECT_NTH(name, proto, alias) \
201      name proto __THROW __asm__ (__ASMNAME (#alias))
202 #  define __REDIRECT_NTHNL(name, proto, alias) \
203      name proto __THROWNL __asm__ (__ASMNAME (#alias))
204 # else
205 #  define __REDIRECT_NTH(name, proto, alias) \
206      name proto __asm__ (__ASMNAME (#alias)) __THROW
207 #  define __REDIRECT_NTHNL(name, proto, alias) \
208      name proto __asm__ (__ASMNAME (#alias)) __THROWNL
209 # endif
210 # define __ASMNAME(cname)  __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
211 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
212 
213 /*
214 #elif __SOME_OTHER_COMPILER__
215 
216 # define __REDIRECT(name, proto, alias) name proto; \
217 	_Pragma("let " #name " = " #alias)
218 */
219 #endif
220 
221 /* GCC and clang have various useful declarations that can be made with
222    the '__attribute__' syntax.  All of the ways we use this do fine if
223    they are omitted for compilers that don't understand it.  */
224 #if !(defined __GNUC__ || defined __clang__)
225 # define __attribute__(xyz)	/* Ignore */
226 #endif
227 
228 /* At some point during the gcc 2.96 development the `malloc' attribute
229    for functions was introduced.  We don't want to use it unconditionally
230    (although this would be possible) since it generates warnings.  */
231 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
232 # define __attribute_malloc__ __attribute__ ((__malloc__))
233 #else
234 # define __attribute_malloc__ /* Ignore */
235 #endif
236 
237 /* Tell the compiler which arguments to an allocation function
238    indicate the size of the allocation.  */
239 #if __GNUC_PREREQ (4, 3)
240 # define __attribute_alloc_size__(params) \
241   __attribute__ ((__alloc_size__ params))
242 #else
243 # define __attribute_alloc_size__(params) /* Ignore.  */
244 #endif
245 
246 /* At some point during the gcc 2.96 development the `pure' attribute
247    for functions was introduced.  We don't want to use it unconditionally
248    (although this would be possible) since it generates warnings.  */
249 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
250 # define __attribute_pure__ __attribute__ ((__pure__))
251 #else
252 # define __attribute_pure__ /* Ignore */
253 #endif
254 
255 /* This declaration tells the compiler that the value is constant.  */
256 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
257 # define __attribute_const__ __attribute__ ((__const__))
258 #else
259 # define __attribute_const__ /* Ignore */
260 #endif
261 
262 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
263 # define __attribute_maybe_unused__ __attribute__ ((__unused__))
264 #else
265 # define __attribute_maybe_unused__ /* Ignore */
266 #endif
267 
268 /* At some point during the gcc 3.1 development the `used' attribute
269    for functions was introduced.  We don't want to use it unconditionally
270    (although this would be possible) since it generates warnings.  */
271 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
272 # define __attribute_used__ __attribute__ ((__used__))
273 # define __attribute_noinline__ __attribute__ ((__noinline__))
274 #else
275 # define __attribute_used__ __attribute__ ((__unused__))
276 # define __attribute_noinline__ /* Ignore */
277 #endif
278 
279 /* Since version 3.2, gcc allows marking deprecated functions.  */
280 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
281 # define __attribute_deprecated__ __attribute__ ((__deprecated__))
282 #else
283 # define __attribute_deprecated__ /* Ignore */
284 #endif
285 
286 /* Since version 4.5, gcc also allows one to specify the message printed
287    when a deprecated function is used.  clang claims to be gcc 4.2, but
288    may also support this feature.  */
289 #if __GNUC_PREREQ (4,5) \
290     || __glibc_has_extension (__attribute_deprecated_with_message__)
291 # define __attribute_deprecated_msg__(msg) \
292 	 __attribute__ ((__deprecated__ (msg)))
293 #else
294 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__
295 #endif
296 
297 /* At some point during the gcc 2.8 development the `format_arg' attribute
298    for functions was introduced.  We don't want to use it unconditionally
299    (although this would be possible) since it generates warnings.
300    If several `format_arg' attributes are given for the same function, in
301    gcc-3.0 and older, all but the last one are ignored.  In newer gccs,
302    all designated arguments are considered.  */
303 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
304 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
305 #else
306 # define __attribute_format_arg__(x) /* Ignore */
307 #endif
308 
309 /* At some point during the gcc 2.97 development the `strfmon' format
310    attribute for functions was introduced.  We don't want to use it
311    unconditionally (although this would be possible) since it
312    generates warnings.  */
313 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
314 # define __attribute_format_strfmon__(a,b) \
315   __attribute__ ((__format__ (__strfmon__, a, b)))
316 #else
317 # define __attribute_format_strfmon__(a,b) /* Ignore */
318 #endif
319 
320 /* The nonnull function attribute marks pointer parameters that
321    must not be NULL.  */
322 #ifndef __nonnull
323 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
324 #  define __nonnull(params) __attribute__ ((__nonnull__ params))
325 # else
326 #  define __nonnull(params)
327 # endif
328 #elif !defined __GLIBC__
329 # undef __nonnull
330 # define __nonnull(params) _GL_ATTRIBUTE_NONNULL (params)
331 #endif
332 
333 /* The returns_nonnull function attribute marks the return type of the function
334    as always being non-null.  */
335 #ifndef __returns_nonnull
336 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
337 # define __returns_nonnull __attribute__ ((__returns_nonnull__))
338 # else
339 # define __returns_nonnull
340 # endif
341 #endif
342 
343 /* If fortification mode, we warn about unused results of certain
344    function calls which can lead to problems.  */
345 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
346 # define __attribute_warn_unused_result__ \
347    __attribute__ ((__warn_unused_result__))
348 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
349 #  define __wur __attribute_warn_unused_result__
350 # endif
351 #else
352 # define __attribute_warn_unused_result__ /* empty */
353 #endif
354 #ifndef __wur
355 # define __wur /* Ignore */
356 #endif
357 
358 /* Forces a function to be always inlined.  */
359 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
360 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and
361    it conflicts with this definition.  Therefore undefine it first to
362    allow either header to be included first.  */
363 # undef __always_inline
364 # define __always_inline __inline __attribute__ ((__always_inline__))
365 #else
366 # undef __always_inline
367 # define __always_inline __inline
368 #endif
369 
370 /* Associate error messages with the source location of the call site rather
371    than with the source location inside the function.  */
372 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
373 # define __attribute_artificial__ __attribute__ ((__artificial__))
374 #else
375 # define __attribute_artificial__ /* Ignore */
376 #endif
377 
378 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
379    inline semantics, unless -fgnu89-inline is used.  Using __GNUC_STDC_INLINE__
380    or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
381    older than 4.3 may define these macros and still not guarantee GNU inlining
382    semantics.
383 
384    clang++ identifies itself as gcc-4.2, but has support for GNU inlining
385    semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
386    __GNUC_GNU_INLINE__ macro definitions.  */
387 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
388      || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
389 			       || defined __GNUC_GNU_INLINE__)))
390 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
391 #  define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
392 #  define __extern_always_inline \
393   extern __always_inline __attribute__ ((__gnu_inline__))
394 # else
395 #  define __extern_inline extern __inline
396 #  define __extern_always_inline extern __always_inline
397 # endif
398 #endif
399 
400 #ifdef __extern_always_inline
401 # define __fortify_function __extern_always_inline __attribute_artificial__
402 #endif
403 
404 /* GCC 4.3 and above allow passing all anonymous arguments of an
405    __extern_always_inline function to some other vararg function.  */
406 #if __GNUC_PREREQ (4,3)
407 # define __va_arg_pack() __builtin_va_arg_pack ()
408 # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
409 #endif
410 
411 /* It is possible to compile containing GCC extensions even if GCC is
412    run in pedantic mode if the uses are carefully marked using the
413    `__extension__' keyword.  But this is not generally available before
414    version 2.8.  */
415 #if !(__GNUC_PREREQ (2,8) || defined __clang__)
416 # define __extension__		/* Ignore */
417 #endif
418 
419 /* __restrict is known in EGCS 1.2 and above, and in clang.
420    It works also in C++ mode (outside of arrays), but only when spelled
421    as '__restrict', not 'restrict'.  */
422 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
423 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
424 #  define __restrict	restrict
425 # else
426 #  define __restrict	/* Ignore */
427 # endif
428 #endif
429 
430 /* ISO C99 also allows to declare arrays as non-overlapping.  The syntax is
431      array_name[restrict]
432    GCC 3.1 and clang support this.
433    This syntax is not usable in C++ mode.  */
434 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
435 # define __restrict_arr	__restrict
436 #else
437 # ifdef __GNUC__
438 #  define __restrict_arr	/* Not supported in old GCC.  */
439 # else
440 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
441 #   define __restrict_arr	restrict
442 #  else
443 /* Some other non-C99 compiler.  */
444 #   define __restrict_arr	/* Not supported.  */
445 #  endif
446 # endif
447 #endif
448 
449 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
450 # define __glibc_unlikely(cond)	__builtin_expect ((cond), 0)
451 # define __glibc_likely(cond)	__builtin_expect ((cond), 1)
452 #else
453 # define __glibc_unlikely(cond)	(cond)
454 # define __glibc_likely(cond)	(cond)
455 #endif
456 
457 #if (!defined _Noreturn \
458      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
459      &&  !(__GNUC_PREREQ (4,7) \
460            || (3 < __clang_major__ + (5 <= __clang_minor__))))
461 # if __GNUC_PREREQ (2,8)
462 #  define _Noreturn __attribute__ ((__noreturn__))
463 # else
464 #  define _Noreturn
465 # endif
466 #endif
467 
468 #if __GNUC_PREREQ (8, 0)
469 /* Describes a char array whose address can safely be passed as the first
470    argument to strncpy and strncat, as the char array is not necessarily
471    a NUL-terminated string.  */
472 # define __attribute_nonstring__ __attribute__ ((__nonstring__))
473 #else
474 # define __attribute_nonstring__
475 #endif
476 
477 /* Undefine (also defined in libc-symbols.h).  */
478 #undef __attribute_copy__
479 #if __GNUC_PREREQ (9, 0)
480 /* Copies attributes from the declaration or type referenced by
481    the argument.  */
482 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
483 #else
484 # define __attribute_copy__(arg)
485 #endif
486 
487 #if (!defined _Static_assert && !defined __cplusplus \
488      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
489      && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
490          || defined __STRICT_ANSI__))
491 # define _Static_assert(expr, diagnostic) \
492     extern int (*__Static_assert_function (void)) \
493       [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
494 #endif
495 
496 /* The #ifndef lets Gnulib avoid including these on non-glibc
497    platforms, where the includes typically do not exist.  */
498 #ifdef __GLIBC__
499 # include <bits/wordsize.h>
500 # include <bits/long-double.h>
501 #endif
502 
503 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
504 # ifdef __REDIRECT
505 
506 /* Alias name defined automatically.  */
507 #  define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
508 #  define __LDBL_REDIR_DECL(name) \
509   extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
510 
511 /* Alias name defined automatically, with leading underscores.  */
512 #  define __LDBL_REDIR2_DECL(name) \
513   extern __typeof (__##name) __##name \
514     __asm (__ASMNAME ("__" #name "ieee128"));
515 
516 /* Alias name defined manually.  */
517 #  define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
518 #  define __LDBL_REDIR1_DECL(name, alias) \
519   extern __typeof (name) name __asm (__ASMNAME (#alias));
520 
521 #  define __LDBL_REDIR1_NTH(name, proto, alias) \
522   __REDIRECT_NTH (name, proto, alias)
523 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
524   __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
525 
526 /* Unused.  */
527 #  define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
528 #  define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
529 
530 # else
531 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
532 # endif
533 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
534 # define __LDBL_COMPAT 1
535 # ifdef __REDIRECT
536 #  define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
537 #  define __LDBL_REDIR(name, proto) \
538   __LDBL_REDIR1 (name, proto, __nldbl_##name)
539 #  define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
540 #  define __LDBL_REDIR_NTH(name, proto) \
541   __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
542 #  define __LDBL_REDIR2_DECL(name) \
543   extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
544 #  define __LDBL_REDIR1_DECL(name, alias) \
545   extern __typeof (name) name __asm (__ASMNAME (#alias));
546 #  define __LDBL_REDIR_DECL(name) \
547   extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
548 #  define __REDIRECT_LDBL(name, proto, alias) \
549   __LDBL_REDIR1 (name, proto, __nldbl_##alias)
550 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
551   __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
552 # endif
553 #endif
554 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
555     || !defined __REDIRECT
556 # define __LDBL_REDIR1(name, proto, alias) name proto
557 # define __LDBL_REDIR(name, proto) name proto
558 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
559 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
560 # define __LDBL_REDIR2_DECL(name)
561 # define __LDBL_REDIR_DECL(name)
562 # ifdef __REDIRECT
563 #  define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
564 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
565   __REDIRECT_NTH (name, proto, alias)
566 # endif
567 #endif
568 
569 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE.  This is
570    intended for use in preprocessor macros.
571 
572    Note: MESSAGE must be a _single_ string; concatenation of string
573    literals is not supported.  */
574 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
575 # define __glibc_macro_warning1(message) _Pragma (#message)
576 # define __glibc_macro_warning(message) \
577   __glibc_macro_warning1 (GCC warning message)
578 #else
579 # define __glibc_macro_warning(msg)
580 #endif
581 
582 /* Generic selection (ISO C11) is a C-only feature, available in GCC
583    since version 4.9.  Previous versions do not provide generic
584    selection, even though they might set __STDC_VERSION__ to 201112L,
585    when in -std=c11 mode.  Thus, we must check for !defined __GNUC__
586    when testing __STDC_VERSION__ for generic selection support.
587    On the other hand, Clang also defines __GNUC__, so a clang-specific
588    check is required to enable the use of generic selection.  */
589 #if !defined __cplusplus \
590     && (__GNUC_PREREQ (4, 9) \
591 	|| __glibc_has_extension (c_generic_selections) \
592 	|| (!defined __GNUC__ && defined __STDC_VERSION__ \
593 	    && __STDC_VERSION__ >= 201112L))
594 # define __HAVE_GENERIC_SELECTION 1
595 #else
596 # define __HAVE_GENERIC_SELECTION 0
597 #endif
598 
599 #if __GNUC_PREREQ (10, 0)
600 /* Designates a 1-based positional argument ref-index of pointer type
601    that can be used to access size-index elements of the pointed-to
602    array according to access mode, or at least one element when
603    size-index is not provided:
604      access (access-mode, <ref-index> [, <size-index>])  */
605 #  define __attr_access(x) __attribute__ ((__access__ x))
606 #  if __GNUC_PREREQ (11, 0)
607 #    define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
608 #  else
609 #    define __attr_access_none(argno)
610 #  endif
611 #else
612 #  define __attr_access(x)
613 #  define __attr_access_none(argno)
614 #endif
615 
616 #if __GNUC_PREREQ (11, 0)
617 /* Designates dealloc as a function to call to deallocate objects
618    allocated by the declared function.  */
619 # define __attr_dealloc(dealloc, argno) \
620     __attribute__ ((__malloc__ (dealloc, argno)))
621 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
622 #else
623 # define __attr_dealloc(dealloc, argno)
624 # define __attr_dealloc_free
625 #endif
626 
627 /* Specify that a function such as setjmp or vfork may return
628    twice.  */
629 #if __GNUC_PREREQ (4, 1)
630 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
631 #else
632 # define __attribute_returns_twice__ /* Ignore.  */
633 #endif
634 
635 #endif	 /* sys/cdefs.h */