root/maint/gnulib/lib/cdefs.h

/* */

INCLUDED FROM

   1 /* Copyright (C) 1992-2021 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 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
 148 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
 149 #else
 150 # define __glibc_objsize0(__o) __bos0 (__o)
 151 # define __glibc_objsize(__o) __bos (__o)
 152 #endif
 153 
 154 /* Compile time conditions to choose between the regular, _chk and _chk_warn
 155    variants.  These conditions should get evaluated to constant and optimized
 156    away.  */
 157 
 158 #define __glibc_safe_len_cond(__l, __s, __osz) ((__l) <= (__osz) / (__s))
 159 #define __glibc_unsigned_or_positive(__l) \
 160   ((__typeof (__l)) 0 < (__typeof (__l)) -1                                   \
 161    || (__builtin_constant_p (__l) && (__l) > 0))
 162 
 163 /* Length is known to be safe at compile time if the __L * __S <= __OBJSZ
 164    condition can be folded to a constant and if it is true.  The -1 check is
 165    redundant because since it implies that __glibc_safe_len_cond is true.  */
 166 #define __glibc_safe_or_unknown_len(__l, __s, __osz) \
 167   (__glibc_unsigned_or_positive (__l)                                         \
 168    && __builtin_constant_p (__glibc_safe_len_cond ((__SIZE_TYPE__) (__l),     \
 169                                                    __s, __osz))               \
 170    && __glibc_safe_len_cond ((__SIZE_TYPE__) (__l), __s, __osz))
 171 
 172 /* Conversely, we know at compile time that the length is safe if the
 173    __L * __S <= __OBJSZ condition can be folded to a constant and if it is
 174    false.  */
 175 #define __glibc_unsafe_len(__l, __s, __osz) \
 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 /* Fortify function f.  __f_alias, __f_chk and __f_chk_warn must be
 182    declared.  */
 183 
 184 #define __glibc_fortify(f, __l, __s, __osz, ...) \
 185   (__glibc_safe_or_unknown_len (__l, __s, __osz)                              \
 186    ? __ ## f ## _alias (__VA_ARGS__)                                          \
 187    : (__glibc_unsafe_len (__l, __s, __osz)                                    \
 188       ? __ ## f ## _chk_warn (__VA_ARGS__, __osz)                             \
 189       : __ ## f ## _chk (__VA_ARGS__, __osz)))                        \
 190 
 191 /* Fortify function f, where object size argument passed to f is the number of
 192    elements and not total size.  */
 193 
 194 #define __glibc_fortify_n(f, __l, __s, __osz, ...) \
 195   (__glibc_safe_or_unknown_len (__l, __s, __osz)                              \
 196    ? __ ## f ## _alias (__VA_ARGS__)                                          \
 197    : (__glibc_unsafe_len (__l, __s, __osz)                                    \
 198       ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s))                   \
 199       : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))                      \
 200 
 201 #if __GNUC_PREREQ (4,3)
 202 # define __warnattr(msg) __attribute__((__warning__ (msg)))
 203 # define __errordecl(name, msg) \
 204   extern void name (void) __attribute__((__error__ (msg)))
 205 #else
 206 # define __warnattr(msg)
 207 # define __errordecl(name, msg) extern void name (void)
 208 #endif
 209 
 210 /* Support for flexible arrays.
 211    Headers that should use flexible arrays only if they're "real"
 212    (e.g. only if they won't affect sizeof()) should test
 213    #if __glibc_c99_flexarr_available.  */
 214 #if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
 215 # define __flexarr      []
 216 # define __glibc_c99_flexarr_available 1
 217 #elif __GNUC_PREREQ (2,97) || defined __clang__
 218 /* GCC 2.97 and clang support C99 flexible array members as an extension,
 219    even when in C89 mode or compiling C++ (any version).  */
 220 # define __flexarr      []
 221 # define __glibc_c99_flexarr_available 1
 222 #elif defined __GNUC__
 223 /* Pre-2.97 GCC did not support C99 flexible arrays but did have
 224    an equivalent extension with slightly different notation.  */
 225 # define __flexarr      [0]
 226 # define __glibc_c99_flexarr_available 1
 227 #else
 228 /* Some other non-C99 compiler.  Approximate with [1].  */
 229 # define __flexarr      [1]
 230 # define __glibc_c99_flexarr_available 0
 231 #endif
 232 
 233 
 234 /* __asm__ ("xyz") is used throughout the headers to rename functions
 235    at the assembly language level.  This is wrapped by the __REDIRECT
 236    macro, in order to support compilers that can do this some other
 237    way.  When compilers don't support asm-names at all, we have to do
 238    preprocessor tricks instead (which don't have exactly the right
 239    semantics, but it's the best we can do).
 240 
 241    Example:
 242    int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
 243 
 244 #if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
 245 
 246 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
 247 # ifdef __cplusplus
 248 #  define __REDIRECT_NTH(name, proto, alias) \
 249      name proto __THROW __asm__ (__ASMNAME (#alias))
 250 #  define __REDIRECT_NTHNL(name, proto, alias) \
 251      name proto __THROWNL __asm__ (__ASMNAME (#alias))
 252 # else
 253 #  define __REDIRECT_NTH(name, proto, alias) \
 254      name proto __asm__ (__ASMNAME (#alias)) __THROW
 255 #  define __REDIRECT_NTHNL(name, proto, alias) \
 256      name proto __asm__ (__ASMNAME (#alias)) __THROWNL
 257 # endif
 258 # define __ASMNAME(cname)  __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
 259 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
 260 
 261 /*
 262 #elif __SOME_OTHER_COMPILER__
 263 
 264 # define __REDIRECT(name, proto, alias) name proto; \
 265         _Pragma("let " #name " = " #alias)
 266 */
 267 #endif
 268 
 269 /* GCC and clang have various useful declarations that can be made with
 270    the '__attribute__' syntax.  All of the ways we use this do fine if
 271    they are omitted for compilers that don't understand it.  */
 272 #if !(defined __GNUC__ || defined __clang__)
 273 # define __attribute__(xyz)     /* Ignore */
 274 #endif
 275 
 276 /* At some point during the gcc 2.96 development the `malloc' attribute
 277    for functions was introduced.  We don't want to use it unconditionally
 278    (although this would be possible) since it generates warnings.  */
 279 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__malloc__)
 280 # define __attribute_malloc__ __attribute__ ((__malloc__))
 281 #else
 282 # define __attribute_malloc__ /* Ignore */
 283 #endif
 284 
 285 /* Tell the compiler which arguments to an allocation function
 286    indicate the size of the allocation.  */
 287 #if __GNUC_PREREQ (4, 3)
 288 # define __attribute_alloc_size__(params) \
 289   __attribute__ ((__alloc_size__ params))
 290 #else
 291 # define __attribute_alloc_size__(params) /* Ignore.  */
 292 #endif
 293 
 294 /* Tell the compiler which argument to an allocation function
 295    indicates the alignment of the allocation.  */
 296 #if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__alloc_align__)
 297 # define __attribute_alloc_align__(param) \
 298   __attribute__ ((__alloc_align__ param))
 299 #else
 300 # define __attribute_alloc_align__(param) /* Ignore.  */
 301 #endif
 302 
 303 /* At some point during the gcc 2.96 development the `pure' attribute
 304    for functions was introduced.  We don't want to use it unconditionally
 305    (although this would be possible) since it generates warnings.  */
 306 #if __GNUC_PREREQ (2,96) || __glibc_has_attribute (__pure__)
 307 # define __attribute_pure__ __attribute__ ((__pure__))
 308 #else
 309 # define __attribute_pure__ /* Ignore */
 310 #endif
 311 
 312 /* This declaration tells the compiler that the value is constant.  */
 313 #if __GNUC_PREREQ (2,5) || __glibc_has_attribute (__const__)
 314 # define __attribute_const__ __attribute__ ((__const__))
 315 #else
 316 # define __attribute_const__ /* Ignore */
 317 #endif
 318 
 319 #if __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
 320 # define __attribute_maybe_unused__ __attribute__ ((__unused__))
 321 #else
 322 # define __attribute_maybe_unused__ /* Ignore */
 323 #endif
 324 
 325 /* At some point during the gcc 3.1 development the `used' attribute
 326    for functions was introduced.  We don't want to use it unconditionally
 327    (although this would be possible) since it generates warnings.  */
 328 #if __GNUC_PREREQ (3,1) || __glibc_has_attribute (__used__)
 329 # define __attribute_used__ __attribute__ ((__used__))
 330 # define __attribute_noinline__ __attribute__ ((__noinline__))
 331 #else
 332 # define __attribute_used__ __attribute__ ((__unused__))
 333 # define __attribute_noinline__ /* Ignore */
 334 #endif
 335 
 336 /* Since version 3.2, gcc allows marking deprecated functions.  */
 337 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__deprecated__)
 338 # define __attribute_deprecated__ __attribute__ ((__deprecated__))
 339 #else
 340 # define __attribute_deprecated__ /* Ignore */
 341 #endif
 342 
 343 /* Since version 4.5, gcc also allows one to specify the message printed
 344    when a deprecated function is used.  clang claims to be gcc 4.2, but
 345    may also support this feature.  */
 346 #if __GNUC_PREREQ (4,5) \
 347     || __glibc_has_extension (__attribute_deprecated_with_message__)
 348 # define __attribute_deprecated_msg__(msg) \
 349          __attribute__ ((__deprecated__ (msg)))
 350 #else
 351 # define __attribute_deprecated_msg__(msg) __attribute_deprecated__
 352 #endif
 353 
 354 /* At some point during the gcc 2.8 development the `format_arg' attribute
 355    for functions was introduced.  We don't want to use it unconditionally
 356    (although this would be possible) since it generates warnings.
 357    If several `format_arg' attributes are given for the same function, in
 358    gcc-3.0 and older, all but the last one are ignored.  In newer gccs,
 359    all designated arguments are considered.  */
 360 #if __GNUC_PREREQ (2,8) || __glibc_has_attribute (__format_arg__)
 361 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
 362 #else
 363 # define __attribute_format_arg__(x) /* Ignore */
 364 #endif
 365 
 366 /* At some point during the gcc 2.97 development the `strfmon' format
 367    attribute for functions was introduced.  We don't want to use it
 368    unconditionally (although this would be possible) since it
 369    generates warnings.  */
 370 #if __GNUC_PREREQ (2,97) || __glibc_has_attribute (__format__)
 371 # define __attribute_format_strfmon__(a,b) \
 372   __attribute__ ((__format__ (__strfmon__, a, b)))
 373 #else
 374 # define __attribute_format_strfmon__(a,b) /* Ignore */
 375 #endif
 376 
 377 /* The nonnull function attribute marks pointer parameters that
 378    must not be NULL.  This has the name __nonnull in glibc,
 379    and __attribute_nonnull__ in files shared with Gnulib to avoid
 380    collision with a different __nonnull in DragonFlyBSD 5.9.  */
 381 #ifndef __attribute_nonnull__
 382 # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__)
 383 #  define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params))
 384 # else
 385 #  define __attribute_nonnull__(params)
 386 # endif
 387 #endif
 388 #ifndef __nonnull
 389 # define __nonnull(params) __attribute_nonnull__ (params)
 390 #endif
 391 
 392 /* The returns_nonnull function attribute marks the return type of the function
 393    as always being non-null.  */
 394 #ifndef __returns_nonnull
 395 # if __GNUC_PREREQ (4, 9) || __glibc_has_attribute (__returns_nonnull__)
 396 # define __returns_nonnull __attribute__ ((__returns_nonnull__))
 397 # else
 398 # define __returns_nonnull
 399 # endif
 400 #endif
 401 
 402 /* If fortification mode, we warn about unused results of certain
 403    function calls which can lead to problems.  */
 404 #if __GNUC_PREREQ (3,4) || __glibc_has_attribute (__warn_unused_result__)
 405 # define __attribute_warn_unused_result__ \
 406    __attribute__ ((__warn_unused_result__))
 407 # if defined __USE_FORTIFY_LEVEL && __USE_FORTIFY_LEVEL > 0
 408 #  define __wur __attribute_warn_unused_result__
 409 # endif
 410 #else
 411 # define __attribute_warn_unused_result__ /* empty */
 412 #endif
 413 #ifndef __wur
 414 # define __wur /* Ignore */
 415 #endif
 416 
 417 /* Forces a function to be always inlined.  */
 418 #if __GNUC_PREREQ (3,2) || __glibc_has_attribute (__always_inline__)
 419 /* The Linux kernel defines __always_inline in stddef.h (283d7573), and
 420    it conflicts with this definition.  Therefore undefine it first to
 421    allow either header to be included first.  */
 422 # undef __always_inline
 423 # define __always_inline __inline __attribute__ ((__always_inline__))
 424 #else
 425 # undef __always_inline
 426 # define __always_inline __inline
 427 #endif
 428 
 429 /* Associate error messages with the source location of the call site rather
 430    than with the source location inside the function.  */
 431 #if __GNUC_PREREQ (4,3) || __glibc_has_attribute (__artificial__)
 432 # define __attribute_artificial__ __attribute__ ((__artificial__))
 433 #else
 434 # define __attribute_artificial__ /* Ignore */
 435 #endif
 436 
 437 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
 438    inline semantics, unless -fgnu89-inline is used.  Using __GNUC_STDC_INLINE__
 439    or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
 440    older than 4.3 may define these macros and still not guarantee GNU inlining
 441    semantics.
 442 
 443    clang++ identifies itself as gcc-4.2, but has support for GNU inlining
 444    semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
 445    __GNUC_GNU_INLINE__ macro definitions.  */
 446 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
 447      || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
 448                                || defined __GNUC_GNU_INLINE__)))
 449 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
 450 #  define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
 451 #  define __extern_always_inline \
 452   extern __always_inline __attribute__ ((__gnu_inline__))
 453 # else
 454 #  define __extern_inline extern __inline
 455 #  define __extern_always_inline extern __always_inline
 456 # endif
 457 #endif
 458 
 459 #ifdef __extern_always_inline
 460 # define __fortify_function __extern_always_inline __attribute_artificial__
 461 #endif
 462 
 463 /* GCC 4.3 and above allow passing all anonymous arguments of an
 464    __extern_always_inline function to some other vararg function.  */
 465 #if __GNUC_PREREQ (4,3)
 466 # define __va_arg_pack() __builtin_va_arg_pack ()
 467 # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
 468 #endif
 469 
 470 /* It is possible to compile containing GCC extensions even if GCC is
 471    run in pedantic mode if the uses are carefully marked using the
 472    `__extension__' keyword.  But this is not generally available before
 473    version 2.8.  */
 474 #if !(__GNUC_PREREQ (2,8) || defined __clang__)
 475 # define __extension__          /* Ignore */
 476 #endif
 477 
 478 /* __restrict is known in EGCS 1.2 and above, and in clang.
 479    It works also in C++ mode (outside of arrays), but only when spelled
 480    as '__restrict', not 'restrict'.  */
 481 #if !(__GNUC_PREREQ (2,92) || __clang_major__ >= 3)
 482 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 483 #  define __restrict    restrict
 484 # else
 485 #  define __restrict    /* Ignore */
 486 # endif
 487 #endif
 488 
 489 /* ISO C99 also allows to declare arrays as non-overlapping.  The syntax is
 490      array_name[restrict]
 491    GCC 3.1 and clang support this.
 492    This syntax is not usable in C++ mode.  */
 493 #if (__GNUC_PREREQ (3,1) || __clang_major__ >= 3) && !defined __cplusplus
 494 # define __restrict_arr __restrict
 495 #else
 496 # ifdef __GNUC__
 497 #  define __restrict_arr        /* Not supported in old GCC.  */
 498 # else
 499 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 500 #   define __restrict_arr       restrict
 501 #  else
 502 /* Some other non-C99 compiler.  */
 503 #   define __restrict_arr       /* Not supported.  */
 504 #  endif
 505 # endif
 506 #endif
 507 
 508 #if (__GNUC__ >= 3) || __glibc_has_builtin (__builtin_expect)
 509 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
 510 # define __glibc_likely(cond)   __builtin_expect ((cond), 1)
 511 #else
 512 # define __glibc_unlikely(cond) (cond)
 513 # define __glibc_likely(cond)   (cond)
 514 #endif
 515 
 516 #if (!defined _Noreturn \
 517      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
 518      &&  !(__GNUC_PREREQ (4,7) \
 519            || (3 < __clang_major__ + (5 <= __clang_minor__))))
 520 # if __GNUC_PREREQ (2,8)
 521 #  define _Noreturn __attribute__ ((__noreturn__))
 522 # else
 523 #  define _Noreturn
 524 # endif
 525 #endif
 526 
 527 #if __GNUC_PREREQ (8, 0)
 528 /* Describes a char array whose address can safely be passed as the first
 529    argument to strncpy and strncat, as the char array is not necessarily
 530    a NUL-terminated string.  */
 531 # define __attribute_nonstring__ __attribute__ ((__nonstring__))
 532 #else
 533 # define __attribute_nonstring__
 534 #endif
 535 
 536 /* Undefine (also defined in libc-symbols.h).  */
 537 #undef __attribute_copy__
 538 #if __GNUC_PREREQ (9, 0)
 539 /* Copies attributes from the declaration or type referenced by
 540    the argument.  */
 541 # define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
 542 #else
 543 # define __attribute_copy__(arg)
 544 #endif
 545 
 546 #if (!defined _Static_assert && !defined __cplusplus \
 547      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
 548      && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
 549          || defined __STRICT_ANSI__))
 550 # define _Static_assert(expr, diagnostic) \
 551     extern int (*__Static_assert_function (void)) \
 552       [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
 553 #endif
 554 
 555 /* Gnulib avoids including these, as they don't work on non-glibc or
 556    older glibc platforms.  */
 557 #ifndef __GNULIB_CDEFS
 558 # include <bits/wordsize.h>
 559 # include <bits/long-double.h>
 560 #endif
 561 
 562 #if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
 563 # ifdef __REDIRECT
 564 
 565 /* Alias name defined automatically.  */
 566 #  define __LDBL_REDIR(name, proto) ... unused__ldbl_redir
 567 #  define __LDBL_REDIR_DECL(name) \
 568   extern __typeof (name) name __asm (__ASMNAME ("__" #name "ieee128"));
 569 
 570 /* Alias name defined automatically, with leading underscores.  */
 571 #  define __LDBL_REDIR2_DECL(name) \
 572   extern __typeof (__##name) __##name \
 573     __asm (__ASMNAME ("__" #name "ieee128"));
 574 
 575 /* Alias name defined manually.  */
 576 #  define __LDBL_REDIR1(name, proto, alias) ... unused__ldbl_redir1
 577 #  define __LDBL_REDIR1_DECL(name, alias) \
 578   extern __typeof (name) name __asm (__ASMNAME (#alias));
 579 
 580 #  define __LDBL_REDIR1_NTH(name, proto, alias) \
 581   __REDIRECT_NTH (name, proto, alias)
 582 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
 583   __LDBL_REDIR1_NTH (name, proto, __##alias##ieee128)
 584 
 585 /* Unused.  */
 586 #  define __REDIRECT_LDBL(name, proto, alias) ... unused__redirect_ldbl
 587 #  define __LDBL_REDIR_NTH(name, proto) ... unused__ldbl_redir_nth
 588 
 589 # else
 590 _Static_assert (0, "IEEE 128-bits long double requires redirection on this platform");
 591 # endif
 592 #elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
 593 # define __LDBL_COMPAT 1
 594 # ifdef __REDIRECT
 595 #  define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
 596 #  define __LDBL_REDIR(name, proto) \
 597   __LDBL_REDIR1 (name, proto, __nldbl_##name)
 598 #  define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
 599 #  define __LDBL_REDIR_NTH(name, proto) \
 600   __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
 601 #  define __LDBL_REDIR2_DECL(name) \
 602   extern __typeof (__##name) __##name __asm (__ASMNAME ("__nldbl___" #name));
 603 #  define __LDBL_REDIR1_DECL(name, alias) \
 604   extern __typeof (name) name __asm (__ASMNAME (#alias));
 605 #  define __LDBL_REDIR_DECL(name) \
 606   extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
 607 #  define __REDIRECT_LDBL(name, proto, alias) \
 608   __LDBL_REDIR1 (name, proto, __nldbl_##alias)
 609 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
 610   __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
 611 # endif
 612 #endif
 613 #if (!defined __LDBL_COMPAT && __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0) \
 614     || !defined __REDIRECT
 615 # define __LDBL_REDIR1(name, proto, alias) name proto
 616 # define __LDBL_REDIR(name, proto) name proto
 617 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
 618 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
 619 # define __LDBL_REDIR2_DECL(name)
 620 # define __LDBL_REDIR_DECL(name)
 621 # ifdef __REDIRECT
 622 #  define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
 623 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
 624   __REDIRECT_NTH (name, proto, alias)
 625 # endif
 626 #endif
 627 
 628 /* __glibc_macro_warning (MESSAGE) issues warning MESSAGE.  This is
 629    intended for use in preprocessor macros.
 630 
 631    Note: MESSAGE must be a _single_ string; concatenation of string
 632    literals is not supported.  */
 633 #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
 634 # define __glibc_macro_warning1(message) _Pragma (#message)
 635 # define __glibc_macro_warning(message) \
 636   __glibc_macro_warning1 (GCC warning message)
 637 #else
 638 # define __glibc_macro_warning(msg)
 639 #endif
 640 
 641 /* Generic selection (ISO C11) is a C-only feature, available in GCC
 642    since version 4.9.  Previous versions do not provide generic
 643    selection, even though they might set __STDC_VERSION__ to 201112L,
 644    when in -std=c11 mode.  Thus, we must check for !defined __GNUC__
 645    when testing __STDC_VERSION__ for generic selection support.
 646    On the other hand, Clang also defines __GNUC__, so a clang-specific
 647    check is required to enable the use of generic selection.  */
 648 #if !defined __cplusplus \
 649     && (__GNUC_PREREQ (4, 9) \
 650         || __glibc_has_extension (c_generic_selections) \
 651         || (!defined __GNUC__ && defined __STDC_VERSION__ \
 652             && __STDC_VERSION__ >= 201112L))
 653 # define __HAVE_GENERIC_SELECTION 1
 654 #else
 655 # define __HAVE_GENERIC_SELECTION 0
 656 #endif
 657 
 658 #if __GNUC_PREREQ (10, 0)
 659 /* Designates a 1-based positional argument ref-index of pointer type
 660    that can be used to access size-index elements of the pointed-to
 661    array according to access mode, or at least one element when
 662    size-index is not provided:
 663      access (access-mode, <ref-index> [, <size-index>])  */
 664 #  define __attr_access(x) __attribute__ ((__access__ x))
 665 /* For _FORTIFY_SOURCE == 3 we use __builtin_dynamic_object_size, which may
 666    use the access attribute to get object sizes from function definition
 667    arguments, so we can't use them on functions we fortify.  Drop the object
 668    size hints for such functions.  */
 669 #  if __USE_FORTIFY_LEVEL == 3
 670 #    define __fortified_attr_access(a, o, s) __attribute__ ((__access__ (a, o)))
 671 #  else
 672 #    define __fortified_attr_access(a, o, s) __attr_access ((a, o, s))
 673 #  endif
 674 #  if __GNUC_PREREQ (11, 0)
 675 #    define __attr_access_none(argno) __attribute__ ((__access__ (__none__, argno)))
 676 #  else
 677 #    define __attr_access_none(argno)
 678 #  endif
 679 #else
 680 #  define __fortified_attr_access(a, o, s)
 681 #  define __attr_access(x)
 682 #  define __attr_access_none(argno)
 683 #endif
 684 
 685 #if __GNUC_PREREQ (11, 0)
 686 /* Designates dealloc as a function to call to deallocate objects
 687    allocated by the declared function.  */
 688 # define __attr_dealloc(dealloc, argno) \
 689     __attribute__ ((__malloc__ (dealloc, argno)))
 690 # define __attr_dealloc_free __attr_dealloc (__builtin_free, 1)
 691 #else
 692 # define __attr_dealloc(dealloc, argno)
 693 # define __attr_dealloc_free
 694 #endif
 695 
 696 /* Specify that a function such as setjmp or vfork may return
 697    twice.  */
 698 #if __GNUC_PREREQ (4, 1)
 699 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
 700 #else
 701 # define __attribute_returns_twice__ /* Ignore.  */
 702 #endif
 703 
 704 #endif   /* sys/cdefs.h */

/* */