include/ansidecl.h

   1 /* ANSI and traditional C compatability macros
   2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* ANSI and traditional C compatibility macros
  21
  22    ANSI C is assumed if __STDC__ is #defined.
  23
  24    Macro        ANSI C definition       Traditional C definition
  25    -----        ---- - ----------       ----------- - ----------
  26    PTR          `void *'                `char *'
  27    LONG_DOUBLE  `long double'           `double'
  28    VOLATILE     `volatile'              `'
  29    SIGNED       `signed'                `'
  30    PTRCONST     `void *const'           `char *'
  31    ANSI_PROTOTYPES  1                   not defined
  32
  33    CONST is also defined, but is obsolete.  Just use const.
  34
  35    obsolete --     DEFUN (name, arglist, args)
  36
  37         Defines function NAME.
  38
  39         ARGLIST lists the arguments, separated by commas and enclosed in
  40         parentheses.  ARGLIST becomes the argument list in traditional C.
  41
  42         ARGS list the arguments with their types.  It becomes a prototype in
  43         ANSI C, and the type declarations in traditional C.  Arguments should
  44         be separated with `AND'.  For functions with a variable number of
  45         arguments, the last thing listed should be `DOTS'.
  46
  47    obsolete --     DEFUN_VOID (name)
  48
  49         Defines a function NAME, which takes no arguments.
  50
  51    obsolete --     EXFUN (name, (prototype))    -- obsolete.
  52
  53         Replaced by PARAMS.  Do not use; will disappear someday soon.
  54         Was used in external function declarations.
  55         In ANSI C it is `NAME PROTOTYPE' (so PROTOTYPE should be enclosed in
  56         parentheses).  In traditional C it is `NAME()'.
  57         For a function that takes no arguments, PROTOTYPE should be `(void)'.
  58
  59    obsolete --     PROTO (type, name, (prototype)    -- obsolete.
  60
  61         This one has also been replaced by PARAMS.  Do not use.
  62
  63    PARAMS ((args))
  64
  65         We could use the EXFUN macro to handle prototype declarations, but
  66         the name is misleading and the result is ugly.  So we just define a
  67         simple macro to handle the parameter lists, as in:
  68
  69               static int foo PARAMS ((int, char));
  70
  71         This produces:  `static int foo();' or `static int foo (int, char);'
  72
  73         EXFUN would have done it like this:
  74
  75               static int EXFUN (foo, (int, char));
  76
  77         but the function is not external...and it's hard to visually parse
  78         the function name out of the mess.   EXFUN should be considered
  79         obsolete; new code should be written to use PARAMS.
  80
  81    DOTS is also obsolete.
  82
  83    Examples:
  84
  85         extern int printf PARAMS ((const char *format, ...));
  86 */
  87
  88 #ifndef _ANSIDECL_H
  89
  90 #define _ANSIDECL_H     1
  91
  92
  93 /* Every source file includes this file,
  94    so they will all get the switch for lint.  */
  95 /* LINTLIBRARY */
  96
  97
  98 #if defined (__STDC__) || defined (_AIX) || (defined (__mips) && defined (_SYSTYPE_SVR4)) || defined(_WIN32)
  99 /* All known AIX compilers implement these things (but don't always
 100    define __STDC__).  The RISC/OS MIPS compiler defines these things
 101    in SVR4 mode, but does not define __STDC__.  */
 102
 103 #define PTR             void *
 104 #define PTRCONST        void *CONST
 105 #define LONG_DOUBLE     long double
 106
 107 #ifndef IN_GCC
 108 #define AND             ,
 109 #define NOARGS          void
 110 #define VOLATILE        volatile
 111 #define SIGNED          signed
 112 #endif /* ! IN_GCC */
 113
 114 #define PARAMS(paramlist)               paramlist
 115 #define ANSI_PROTOTYPES                 1
 116
 117 #define VPARAMS(ARGS)                   ARGS
 118 #define VA_START(va_list,var)           va_start(va_list,var)
 119
 120 /* These are obsolete.  Do not use.  */
 121 #ifndef IN_GCC
 122 #define CONST                           const
 123 #define DOTS                            , ...
 124 #define PROTO(type, name, arglist)      type name arglist
 125 #define EXFUN(name, proto)              name proto
 126 #define DEFUN(name, arglist, args)      name(args)
 127 #define DEFUN_VOID(name)                name(void)
 128 #endif /* ! IN_GCC */
 129
 130 #else   /* Not ANSI C.  */
 131
 132 #define PTR             char *
 133 #define PTRCONST        PTR
 134 #define LONG_DOUBLE     double
 135
 136 #ifndef IN_GCC
 137 #define AND             ;
 138 #define NOARGS
 139 #define VOLATILE
 140 #define SIGNED
 141 #endif /* !IN_GCC */
 142
 143 #ifndef const /* some systems define it in header files for non-ansi mode */
 144 #define const
 145 #endif
 146
 147 #define PARAMS(paramlist)               ()
 148
 149 #define VPARAMS(ARGS)                   (va_alist) va_dcl
 150 #define VA_START(va_list,var)           va_start(va_list)
 151
 152 /* These are obsolete.  Do not use.  */
 153 #ifndef IN_GCC
 154 #define CONST
 155 #define DOTS
 156 #define PROTO(type, name, arglist)      type name ()
 157 #define EXFUN(name, proto)              name()
 158 #define DEFUN(name, arglist, args)      name arglist args;
 159 #define DEFUN_VOID(name)                name()
 160 #endif /* ! IN_GCC */
 161
 162 #endif  /* ANSI C.  */
 163
 164 /* This is for GCC, which has historically used typed null pointer
 165    constants.  It needs to be here so it is seen by headers included
 166    by gcc's config.h.
 167
 168    FIXME: GCC probably doesn't need to use typed nulls anymore.
 169    Clean it up, then remove this.  Ware variable-argument functions.  */
 170 #ifdef IN_GCC
 171 # define NULL_PTR ((PTR) 0)
 172 #endif
 173
 174 /* Using MACRO(x,y) in cpp #if conditionals does not work with some
 175    older preprocessors.  Thus we can't define something like this:
 176
 177 #define HAVE_GCC_VERSION(MAJOR, MINOR) \
 178   (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR)))
 179
 180 and then test "#if HAVE_GCC_VERSION(2,7)".
 181
 182 So instead we use the macro below and test it against specific values.  */
 183
 184 /* This macro simplifies testing whether we are using gcc, and if it
 185    is of a particular minimum version. (Both major & minor numbers are
 186    significant.)  This macro will evaluate to 0 if we are not using
 187    gcc at all.  */
 188 #ifndef GCC_VERSION
 189 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
 190 #endif /* GCC_VERSION */
 191
 192 /* Define macros for some gcc attributes.  This permits us to use the
 193    macros freely, and know that they will come into play for the
 194    version of gcc in which they are supported.  */
 195
 196 #if (GCC_VERSION < 2007)
 197 # define __attribute__(x)
 198 #endif
 199
 200 /* Attribute __malloc__ on functions was valid as of gcc 2.96. */
 201 #ifndef ATTRIBUTE_MALLOC
 202 # if (GCC_VERSION >= 2096)
 203 #  define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
 204 # else
 205 #  define ATTRIBUTE_MALLOC
 206 # endif /* GNUC >= 2.96 */
 207 #endif /* ATTRIBUTE_MALLOC */
 208
 209 /* Attributes on labels were valid as of gcc 2.93. */
 210 #ifndef ATTRIBUTE_UNUSED_LABEL
 211 # if (GCC_VERSION >= 2093)
 212 #  define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED
 213 # else
 214 #  define ATTRIBUTE_UNUSED_LABEL
 215 # endif /* GNUC >= 2.93 */
 216 #endif /* ATTRIBUTE_UNUSED_LABEL */
 217
 218 #ifndef ATTRIBUTE_UNUSED
 219 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
 220 #endif /* ATTRIBUTE_UNUSED */
 221
 222 #ifndef ATTRIBUTE_NORETURN
 223 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
 224 #endif /* ATTRIBUTE_NORETURN */
 225
 226 #ifndef ATTRIBUTE_PRINTF
 227 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
 228 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
 229 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
 230 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
 231 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
 232 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
 233 #endif /* ATTRIBUTE_PRINTF */
 234
 235 /* We use __extension__ in some places to suppress -pedantic warnings
 236    about GCC extensions.  This feature didn't work properly before
 237    gcc 2.8.  */
 238 #if GCC_VERSION < 2008
 239 #define __extension__
 240 #endif
 241
 242 /* Bootstrap support: Autoconf will possibly define the `inline' or
 243    `const' keywords as macros, however this is only valid for the
 244    stage1 compiler.  If we detect a modern version of gcc,
 245    unconditionally reset the values.  This makes sure the right thing
 246    happens in stage2 and later.  We need to do this very early;
 247    i.e. before any header files that might use these keywords.
 248    Otherwise conflicts might occur.  */
 249
 250 #if (GCC_VERSION >= 2007)
 251 # ifdef __STDC__
 252 #  undef const
 253 # endif
 254 # undef inline
 255 # define inline __inline__  /* __inline__ prevents -pedantic warnings */
 256 # ifndef HAVE_LONG_DOUBLE
 257 #  define HAVE_LONG_DOUBLE 1
 258 # endif
 259 #endif /* GCC >= 2.7 */
 260
 261 #endif  /* ansidecl.h   */