misc/sys/cdefs.h

   1 /* Copyright (C) 1992-2014 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    <http://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    anymore supported.  */
  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 #ifdef __GNUC__
  38
  39 /* All functions, except those with callbacks or those that
  40    synchronize memory, are leaf functions.  */
  41 # if __GNUC_PREREQ (4, 6) && !defined _LIBC
  42 #  define __LEAF , __leaf__
  43 #  define __LEAF_ATTR __attribute__ ((__leaf__))
  44 # else
  45 #  define __LEAF
  46 #  define __LEAF_ATTR
  47 # endif
  48
  49 /* GCC can always grok prototypes.  For C++ programs we add throw()
  50    to help it optimize the function calls.  But this works only with
  51    gcc 2.8.x and egcs.  For gcc 3.2 and up we even mark C functions
  52    as non-throwing using a function attribute since programs can use
  53    the -fexceptions options for C code as well.  */
  54 # if !defined __cplusplus && __GNUC_PREREQ (3, 3)
  55 #  define __THROW       __attribute__ ((__nothrow__ __LEAF))
  56 #  define __THROWNL     __attribute__ ((__nothrow__))
  57 #  define __NTH(fct)    __attribute__ ((__nothrow__ __LEAF)) fct
  58 # else
  59 #  if defined __cplusplus && __GNUC_PREREQ (2,8)
  60 #   define __THROW      throw ()
  61 #   define __THROWNL    throw ()
  62 #   define __NTH(fct)   __LEAF_ATTR fct throw ()
  63 #  else
  64 #   define __THROW
  65 #   define __THROWNL
  66 #   define __NTH(fct)   fct
  67 #  endif
  68 # endif
  69
  70 #else   /* Not GCC.  */
  71
  72 # define __inline               /* No inline functions.  */
  73
  74 # define __THROW
  75 # define __THROWNL
  76 # define __NTH(fct)     fct
  77
  78 #endif  /* GCC.  */
  79
  80 /* These two macros are not used in glibc anymore.  They are kept here
  81    only because some other projects expect the macros to be defined.  */
  82 #define __P(args)       args
  83 #define __PMT(args)     args
  84
  85 /* For these things, GCC behaves the ANSI way normally,
  86    and the non-ANSI way under -traditional.  */
  87
  88 #define __CONCAT(x,y)   x ## y
  89 #define __STRING(x)     #x
  90
  91 /* This is not a typedef so `const __ptr_t' does the right thing.  */
  92 #define __ptr_t void *
  93 #define __long_double_t  long double
  94
  95
  96 /* C++ needs to know that types and declarations are C, not C++.  */
  97 #ifdef  __cplusplus
  98 # define __BEGIN_DECLS  extern "C" {
  99 # define __END_DECLS    }
 100 #else
 101 # define __BEGIN_DECLS
 102 # define __END_DECLS
 103 #endif
 104
 105
 106 /* The standard library needs the functions from the ISO C90 standard
 107    in the std namespace.  At the same time we want to be safe for
 108    future changes and we include the ISO C99 code in the non-standard
 109    namespace __c99.  The C++ wrapper header take case of adding the
 110    definitions to the global namespace.  */
 111 #if defined __cplusplus && defined _GLIBCPP_USE_NAMESPACES
 112 # define __BEGIN_NAMESPACE_STD  namespace std {
 113 # define __END_NAMESPACE_STD    }
 114 # define __USING_NAMESPACE_STD(name) using std::name;
 115 # define __BEGIN_NAMESPACE_C99  namespace __c99 {
 116 # define __END_NAMESPACE_C99    }
 117 # define __USING_NAMESPACE_C99(name) using __c99::name;
 118 #else
 119 /* For compatibility we do not add the declarations into any
 120    namespace.  They will end up in the global namespace which is what
 121    old code expects.  */
 122 # define __BEGIN_NAMESPACE_STD
 123 # define __END_NAMESPACE_STD
 124 # define __USING_NAMESPACE_STD(name)
 125 # define __BEGIN_NAMESPACE_C99
 126 # define __END_NAMESPACE_C99
 127 # define __USING_NAMESPACE_C99(name)
 128 #endif
 129
 130
 131 /* Fortify support.  */
 132 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
 133 #define __bos0(ptr) __builtin_object_size (ptr, 0)
 134
 135 #if __GNUC_PREREQ (4,3)
 136 # define __warndecl(name, msg) \
 137   extern void name (void) __attribute__((__warning__ (msg)))
 138 # define __warnattr(msg) __attribute__((__warning__ (msg)))
 139 # define __errordecl(name, msg) \
 140   extern void name (void) __attribute__((__error__ (msg)))
 141 #else
 142 # define __warndecl(name, msg) extern void name (void)
 143 # define __warnattr(msg)
 144 # define __errordecl(name, msg) extern void name (void)
 145 #endif
 146
 147 /* Support for flexible arrays.  */
 148 #if __GNUC_PREREQ (2,97)
 149 /* GCC 2.97 supports C99 flexible array members.  */
 150 # define __flexarr      []
 151 #else
 152 # ifdef __GNUC__
 153 #  define __flexarr     [0]
 154 # else
 155 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 156 #   define __flexarr    []
 157 #  else
 158 /* Some other non-C99 compiler.  Approximate with [1].  */
 159 #   define __flexarr    [1]
 160 #  endif
 161 # endif
 162 #endif
 163
 164
 165 /* __asm__ ("xyz") is used throughout the headers to rename functions
 166    at the assembly language level.  This is wrapped by the __REDIRECT
 167    macro, in order to support compilers that can do this some other
 168    way.  When compilers don't support asm-names at all, we have to do
 169    preprocessor tricks instead (which don't have exactly the right
 170    semantics, but it's the best we can do).
 171
 172    Example:
 173    int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
 174
 175 #if defined __GNUC__ && __GNUC__ >= 2
 176
 177 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
 178 # ifdef __cplusplus
 179 #  define __REDIRECT_NTH(name, proto, alias) \
 180      name proto __THROW __asm__ (__ASMNAME (#alias))
 181 #  define __REDIRECT_NTHNL(name, proto, alias) \
 182      name proto __THROWNL __asm__ (__ASMNAME (#alias))
 183 # else
 184 #  define __REDIRECT_NTH(name, proto, alias) \
 185      name proto __asm__ (__ASMNAME (#alias)) __THROW
 186 #  define __REDIRECT_NTHNL(name, proto, alias) \
 187      name proto __asm__ (__ASMNAME (#alias)) __THROWNL
 188 # endif
 189 # define __ASMNAME(cname)  __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
 190 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
 191
 192 /*
 193 #elif __SOME_OTHER_COMPILER__
 194
 195 # define __REDIRECT(name, proto, alias) name proto; \
 196         _Pragma("let " #name " = " #alias)
 197 */
 198 #endif
 199
 200 /* GCC has various useful declarations that can be made with the
 201    `__attribute__' syntax.  All of the ways we use this do fine if
 202    they are omitted for compilers that don't understand it. */
 203 #if !defined __GNUC__ || __GNUC__ < 2
 204 # define __attribute__(xyz)     /* Ignore */
 205 #endif
 206
 207 /* At some point during the gcc 2.96 development the `malloc' attribute
 208    for functions was introduced.  We don't want to use it unconditionally
 209    (although this would be possible) since it generates warnings.  */
 210 #if __GNUC_PREREQ (2,96)
 211 # define __attribute_malloc__ __attribute__ ((__malloc__))
 212 #else
 213 # define __attribute_malloc__ /* Ignore */
 214 #endif
 215
 216 /* Tell the compiler which arguments to an allocation function
 217    indicate the size of the allocation.  */
 218 #if __GNUC_PREREQ (4, 3)
 219 # define __attribute_alloc_size__(params) \
 220   __attribute__ ((__alloc_size__ params))
 221 #else
 222 # define __attribute_alloc_size__(params) /* Ignore.  */
 223 #endif
 224
 225 /* At some point during the gcc 2.96 development the `pure' attribute
 226    for functions was introduced.  We don't want to use it unconditionally
 227    (although this would be possible) since it generates warnings.  */
 228 #if __GNUC_PREREQ (2,96)
 229 # define __attribute_pure__ __attribute__ ((__pure__))
 230 #else
 231 # define __attribute_pure__ /* Ignore */
 232 #endif
 233
 234 /* This declaration tells the compiler that the value is constant.  */
 235 #if __GNUC_PREREQ (2,5)
 236 # define __attribute_const__ __attribute__ ((__const__))
 237 #else
 238 # define __attribute_const__ /* Ignore */
 239 #endif
 240
 241 /* At some point during the gcc 3.1 development the `used' attribute
 242    for functions was introduced.  We don't want to use it unconditionally
 243    (although this would be possible) since it generates warnings.  */
 244 #if __GNUC_PREREQ (3,1)
 245 # define __attribute_used__ __attribute__ ((__used__))
 246 # define __attribute_noinline__ __attribute__ ((__noinline__))
 247 #else
 248 # define __attribute_used__ __attribute__ ((__unused__))
 249 # define __attribute_noinline__ /* Ignore */
 250 #endif
 251
 252 /* gcc allows marking deprecated functions.  */
 253 #if __GNUC_PREREQ (3,2)
 254 # define __attribute_deprecated__ __attribute__ ((__deprecated__))
 255 #else
 256 # define __attribute_deprecated__ /* Ignore */
 257 #endif
 258
 259 /* At some point during the gcc 2.8 development the `format_arg' attribute
 260    for functions was introduced.  We don't want to use it unconditionally
 261    (although this would be possible) since it generates warnings.
 262    If several `format_arg' attributes are given for the same function, in
 263    gcc-3.0 and older, all but the last one are ignored.  In newer gccs,
 264    all designated arguments are considered.  */
 265 #if __GNUC_PREREQ (2,8)
 266 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
 267 #else
 268 # define __attribute_format_arg__(x) /* Ignore */
 269 #endif
 270
 271 /* At some point during the gcc 2.97 development the `strfmon' format
 272    attribute for functions was introduced.  We don't want to use it
 273    unconditionally (although this would be possible) since it
 274    generates warnings.  */
 275 #if __GNUC_PREREQ (2,97)
 276 # define __attribute_format_strfmon__(a,b) \
 277   __attribute__ ((__format__ (__strfmon__, a, b)))
 278 #else
 279 # define __attribute_format_strfmon__(a,b) /* Ignore */
 280 #endif
 281
 282 /* The nonull function attribute allows to mark pointer parameters which
 283    must not be NULL.  */
 284 #if __GNUC_PREREQ (3,3)
 285 # define __nonnull(params) __attribute__ ((__nonnull__ params))
 286 #else
 287 # define __nonnull(params)
 288 #endif
 289
 290 /* If fortification mode, we warn about unused results of certain
 291    function calls which can lead to problems.  */
 292 #if __GNUC_PREREQ (3,4)
 293 # define __attribute_warn_unused_result__ \
 294    __attribute__ ((__warn_unused_result__))
 295 # if __USE_FORTIFY_LEVEL > 0
 296 #  define __wur __attribute_warn_unused_result__
 297 # endif
 298 #else
 299 # define __attribute_warn_unused_result__ /* empty */
 300 #endif
 301 #ifndef __wur
 302 # define __wur /* Ignore */
 303 #endif
 304
 305 /* Forces a function to be always inlined.  */
 306 #if __GNUC_PREREQ (3,2)
 307 # define __always_inline __inline __attribute__ ((__always_inline__))
 308 #else
 309 # define __always_inline __inline
 310 #endif
 311
 312 /* Associate error messages with the source location of the call site rather
 313    than with the source location inside the function.  */
 314 #if __GNUC_PREREQ (4,3)
 315 # define __attribute_artificial__ __attribute__ ((__artificial__))
 316 #else
 317 # define __attribute_artificial__ /* Ignore */
 318 #endif
 319
 320 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
 321    inline semantics, unless -fgnu89-inline is used.  Using __GNUC_STDC_INLINE__
 322    or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
 323    older than 4.3 may define these macros and still not guarantee GNU inlining
 324    semantics.
 325
 326    clang++ identifies itself as gcc-4.2, but has support for GNU inlining
 327    semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
 328    __GNUC_GNU_INLINE__ macro definitions.  */
 329 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
 330      || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
 331                                || defined __GNUC_GNU_INLINE__)))
 332 # if defined __GNUC_STDC_INLINE__ || defined __cplusplus
 333 #  define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
 334 #  define __extern_always_inline \
 335   extern __always_inline __attribute__ ((__gnu_inline__))
 336 # else
 337 #  define __extern_inline extern __inline
 338 #  define __extern_always_inline extern __always_inline
 339 # endif
 340 #endif
 341
 342 #ifdef __extern_always_inline
 343 # define __fortify_function __extern_always_inline __attribute_artificial__
 344 #endif
 345
 346 /* GCC 4.3 and above allow passing all anonymous arguments of an
 347    __extern_always_inline function to some other vararg function.  */
 348 #if __GNUC_PREREQ (4,3)
 349 # define __va_arg_pack() __builtin_va_arg_pack ()
 350 # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
 351 #endif
 352
 353 /* It is possible to compile containing GCC extensions even if GCC is
 354    run in pedantic mode if the uses are carefully marked using the
 355    `__extension__' keyword.  But this is not generally available before
 356    version 2.8.  */
 357 #if !__GNUC_PREREQ (2,8)
 358 # define __extension__          /* Ignore */
 359 #endif
 360
 361 /* __restrict is known in EGCS 1.2 and above. */
 362 #if !__GNUC_PREREQ (2,92)
 363 # define __restrict     /* Ignore */
 364 #endif
 365
 366 /* ISO C99 also allows to declare arrays as non-overlapping.  The syntax is
 367      array_name[restrict]
 368    GCC 3.1 supports this.  */
 369 #if __GNUC_PREREQ (3,1) && !defined __GNUG__
 370 # define __restrict_arr __restrict
 371 #else
 372 # ifdef __GNUC__
 373 #  define __restrict_arr        /* Not supported in old GCC.  */
 374 # else
 375 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 376 #   define __restrict_arr       restrict
 377 #  else
 378 /* Some other non-C99 compiler.  */
 379 #   define __restrict_arr       /* Not supported.  */
 380 #  endif
 381 # endif
 382 #endif
 383
 384 #if __GNUC__ >= 3
 385 # define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
 386 # define __glibc_likely(cond)   __builtin_expect ((cond), 1)
 387 #else
 388 # define __glibc_unlikely(cond) (cond)
 389 # define __glibc_likely(cond)   (cond)
 390 #endif
 391
 392 #if (!defined _Noreturn \
 393      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
 394      &&  !__GNUC_PREREQ (4,7))
 395 # if __GNUC_PREREQ (2,8)
 396 #  define _Noreturn __attribute__ ((__noreturn__))
 397 # else
 398 #  define _Noreturn
 399 # endif
 400 #endif
 401
 402 #include <bits/wordsize.h>
 403
 404 #if defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
 405 # define __LDBL_COMPAT 1
 406 # ifdef __REDIRECT
 407 #  define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
 408 #  define __LDBL_REDIR(name, proto) \
 409   __LDBL_REDIR1 (name, proto, __nldbl_##name)
 410 #  define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
 411 #  define __LDBL_REDIR_NTH(name, proto) \
 412   __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
 413 #  define __LDBL_REDIR1_DECL(name, alias) \
 414   extern __typeof (name) name __asm (__ASMNAME (#alias));
 415 #  define __LDBL_REDIR_DECL(name) \
 416   extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
 417 #  define __REDIRECT_LDBL(name, proto, alias) \
 418   __LDBL_REDIR1 (name, proto, __nldbl_##alias)
 419 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
 420   __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
 421 # endif
 422 #endif
 423 #if !defined __LDBL_COMPAT || !defined __REDIRECT
 424 # define __LDBL_REDIR1(name, proto, alias) name proto
 425 # define __LDBL_REDIR(name, proto) name proto
 426 # define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
 427 # define __LDBL_REDIR_NTH(name, proto) name proto __THROW
 428 # define __LDBL_REDIR_DECL(name)
 429 # ifdef __REDIRECT
 430 #  define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
 431 #  define __REDIRECT_NTH_LDBL(name, proto, alias) \
 432   __REDIRECT_NTH (name, proto, alias)
 433 # endif
 434 #endif
 435
 436 #endif   /* sys/cdefs.h */