misc/sys/cdefs.h

   1 /* Copyright (C) 1992-2001, 2002, 2004 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  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    anymore supported.  */
  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 #ifdef __GNUC__
  39
  40 /* GCC can always grok prototypes.  For C++ programs we add throw()
  41    to help it optimize the function calls.  But this works only with
  42    gcc 2.8.x and egcs.  For gcc 3.2 and up we even mark C functions
  43    as non-throwing using a function attribute since programs can use
  44    the -fexceptions options for C code as well.  */
  45 # if !defined __cplusplus && __GNUC_PREREQ (3, 3)
  46 #  define __THROW       __attribute__ ((__nothrow__))
  47 #  define __NTH(fct)    __attribute__ ((__nothrow__)) fct
  48 # else
  49 #  if defined __cplusplus && __GNUC_PREREQ (2,8)
  50 #   define __THROW      throw ()
  51 #   define __NTH(fct)   fct throw ()
  52 #  else
  53 #   define __THROW
  54 #   define __NTH(fct)   fct
  55 #  endif
  56 # endif
  57
  58 #else   /* Not GCC.  */
  59
  60 # define __inline               /* No inline functions.  */
  61
  62 # define __THROW
  63 # define __NTH(fct)     fct
  64
  65 # define __const        const
  66 # define __signed       signed
  67 # define __volatile     volatile
  68
  69 #endif  /* GCC.  */
  70
  71 /* These two macros are not used in glibc anymore.  They are kept here
  72    only because some other projects expect the macros to be defined.  */
  73 #define __P(args)       args
  74 #define __PMT(args)     args
  75
  76 /* For these things, GCC behaves the ANSI way normally,
  77    and the non-ANSI way under -traditional.  */
  78
  79 #define __CONCAT(x,y)   x ## y
  80 #define __STRING(x)     #x
  81
  82 /* This is not a typedef so `const __ptr_t' does the right thing.  */
  83 #define __ptr_t void *
  84 #define __long_double_t  long double
  85
  86
  87 /* C++ needs to know that types and declarations are C, not C++.  */
  88 #ifdef  __cplusplus
  89 # define __BEGIN_DECLS  extern "C" {
  90 # define __END_DECLS    }
  91 #else
  92 # define __BEGIN_DECLS
  93 # define __END_DECLS
  94 #endif
  95
  96
  97 /* The standard library needs the functions from the ISO C90 standard
  98    in the std namespace.  At the same time we want to be safe for
  99    future changes and we include the ISO C99 code in the non-standard
 100    namespace __c99.  The C++ wrapper header take case of adding the
 101    definitions to the global namespace.  */
 102 #if defined __cplusplus && defined _GLIBCPP_USE_NAMESPACES
 103 # define __BEGIN_NAMESPACE_STD  namespace std {
 104 # define __END_NAMESPACE_STD    }
 105 # define __USING_NAMESPACE_STD(name) using std::name;
 106 # define __BEGIN_NAMESPACE_C99  namespace __c99 {
 107 # define __END_NAMESPACE_C99    }
 108 # define __USING_NAMESPACE_C99(name) using __c99::name;
 109 #else
 110 /* For compatibility we do not add the declarations into any
 111    namespace.  They will end up in the global namespace which is what
 112    old code expects.  */
 113 # define __BEGIN_NAMESPACE_STD
 114 # define __END_NAMESPACE_STD
 115 # define __USING_NAMESPACE_STD(name)
 116 # define __BEGIN_NAMESPACE_C99
 117 # define __END_NAMESPACE_C99
 118 # define __USING_NAMESPACE_C99(name)
 119 #endif
 120
 121
 122 /* Support for bounded pointers.  */
 123 #ifndef __BOUNDED_POINTERS__
 124 # define __bounded      /* nothing */
 125 # define __unbounded    /* nothing */
 126 # define __ptrvalue     /* nothing */
 127 #endif
 128
 129
 130 /* Fortify support.  */
 131 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
 132 #define __bos0(ptr) __builtin_object_size (ptr, 0)
 133
 134
 135 /* Support for flexible arrays.  */
 136 #if __GNUC_PREREQ (2,97)
 137 /* GCC 2.97 supports C99 flexible array members.  */
 138 # define __flexarr      []
 139 #else
 140 # ifdef __GNUC__
 141 #  define __flexarr     [0]
 142 # else
 143 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 144 #   define __flexarr    []
 145 #  else
 146 /* Some other non-C99 compiler.  Approximate with [1].  */
 147 #   define __flexarr    [1]
 148 #  endif
 149 # endif
 150 #endif
 151
 152
 153 /* __asm__ ("xyz") is used throughout the headers to rename functions
 154    at the assembly language level.  This is wrapped by the __REDIRECT
 155    macro, in order to support compilers that can do this some other
 156    way.  When compilers don't support asm-names at all, we have to do
 157    preprocessor tricks instead (which don't have exactly the right
 158    semantics, but it's the best we can do).
 159
 160    Example:
 161    int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
 162
 163 #if defined __GNUC__ && __GNUC__ >= 2
 164
 165 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
 166 # ifdef __cplusplus
 167 #  define __REDIRECT_NTH(name, proto, alias) \
 168      name proto __THROW __asm__ (__ASMNAME (#alias))
 169 # else
 170 #  define __REDIRECT_NTH(name, proto, alias) \
 171      name proto __asm__ (__ASMNAME (#alias)) __THROW
 172 # endif
 173 # define __ASMNAME(cname)  __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
 174 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname
 175
 176 /*
 177 #elif __SOME_OTHER_COMPILER__
 178
 179 # define __REDIRECT(name, proto, alias) name proto; \
 180         _Pragma("let " #name " = " #alias)
 181 */
 182 #endif
 183
 184 /* GCC has various useful declarations that can be made with the
 185    `__attribute__' syntax.  All of the ways we use this do fine if
 186    they are omitted for compilers that don't understand it. */
 187 #if !defined __GNUC__ || __GNUC__ < 2
 188 # define __attribute__(xyz)     /* Ignore */
 189 #endif
 190
 191 /* At some point during the gcc 2.96 development the `malloc' attribute
 192    for functions was introduced.  We don't want to use it unconditionally
 193    (although this would be possible) since it generates warnings.  */
 194 #if __GNUC_PREREQ (2,96)
 195 # define __attribute_malloc__ __attribute__ ((__malloc__))
 196 #else
 197 # define __attribute_malloc__ /* Ignore */
 198 #endif
 199
 200 /* At some point during the gcc 2.96 development the `pure' attribute
 201    for functions was introduced.  We don't want to use it unconditionally
 202    (although this would be possible) since it generates warnings.  */
 203 #if __GNUC_PREREQ (2,96)
 204 # define __attribute_pure__ __attribute__ ((__pure__))
 205 #else
 206 # define __attribute_pure__ /* Ignore */
 207 #endif
 208
 209 /* At some point during the gcc 3.1 development the `used' attribute
 210    for functions was introduced.  We don't want to use it unconditionally
 211    (although this would be possible) since it generates warnings.  */
 212 #if __GNUC_PREREQ (3,1)
 213 # define __attribute_used__ __attribute__ ((__used__))
 214 # define __attribute_noinline__ __attribute__ ((__noinline__))
 215 #else
 216 # define __attribute_used__ __attribute__ ((__unused__))
 217 # define __attribute_noinline__ /* Ignore */
 218 #endif
 219
 220 /* gcc allows marking deprecated functions.  */
 221 #if __GNUC_PREREQ (3,2)
 222 # define __attribute_deprecated__ __attribute__ ((__deprecated__))
 223 #else
 224 # define __attribute_deprecated__ /* Ignore */
 225 #endif
 226
 227 /* At some point during the gcc 2.8 development the `format_arg' attribute
 228    for functions was introduced.  We don't want to use it unconditionally
 229    (although this would be possible) since it generates warnings.
 230    If several `format_arg' attributes are given for the same function, in
 231    gcc-3.0 and older, all but the last one are ignored.  In newer gccs,
 232    all designated arguments are considered.  */
 233 #if __GNUC_PREREQ (2,8)
 234 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
 235 #else
 236 # define __attribute_format_arg__(x) /* Ignore */
 237 #endif
 238
 239 /* At some point during the gcc 2.97 development the `strfmon' format
 240    attribute for functions was introduced.  We don't want to use it
 241    unconditionally (although this would be possible) since it
 242    generates warnings.  */
 243 #if __GNUC_PREREQ (2,97)
 244 # define __attribute_format_strfmon__(a,b) \
 245   __attribute__ ((__format__ (__strfmon__, a, b)))
 246 #else
 247 # define __attribute_format_strfmon__(a,b) /* Ignore */
 248 #endif
 249
 250 /* The nonull function attribute allows to mark pointer parameters which
 251    must not be NULL.  */
 252 #if __GNUC_PREREQ (3,3)
 253 # define __nonnull(params) __attribute__ ((__nonnull__ params))
 254 #else
 255 # define __nonnull(params)
 256 #endif
 257
 258 /* It is possible to compile containing GCC extensions even if GCC is
 259    run in pedantic mode if the uses are carefully marked using the
 260    `__extension__' keyword.  But this is not generally available before
 261    version 2.8.  */
 262 #if !__GNUC_PREREQ (2,8)
 263 # define __extension__          /* Ignore */
 264 #endif
 265
 266 /* __restrict is known in EGCS 1.2 and above. */
 267 #if !__GNUC_PREREQ (2,92)
 268 # define __restrict     /* Ignore */
 269 #endif
 270
 271 /* ISO C99 also allows to declare arrays as non-overlapping.  The syntax is
 272      array_name[restrict]
 273    GCC 3.1 supports this.  */
 274 #if __GNUC_PREREQ (3,1) && !defined __GNUG__
 275 # define __restrict_arr __restrict
 276 #else
 277 # ifdef __GNUC__
 278 #  define __restrict_arr        /* Not supported in old GCC.  */
 279 # else
 280 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 281 #   define __restrict_arr       restrict
 282 #  else
 283 /* Some other non-C99 compiler.  */
 284 #   define __restrict_arr       /* Not supported.  */
 285 #  endif
 286 # endif
 287 #endif
 288
 289 #endif   /* sys/cdefs.h */