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  33    CONST is also defined, but is obsolete.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 /* Using MACRO(x,y) in cpp #if conditionals does not work with some
 165    older preprocessors.  Thus we can't define something like this:
 166
 167 #define HAVE_GCC_VERSION(MAJOR, MINOR) \
 168   (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR)))
 169
 170 and then test "#if HAVE_GCC_VERSION(2,7)".
 171
 172 So instead we use the macro below and test it against specific values.  */
 173
 174 /* This macro simplifies testing whether we are using gcc, and if it
 175    is of a particular minimum version. (Both major & minor numbers are
 176    significant.)  This macro will evaluate to 0 if we are not using
 177    gcc at all.  */
 178 #ifndef GCC_VERSION
 179 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
 180 #endif /* GCC_VERSION */
 181
 182 /* Define macros for some gcc attributes.  This permits us to use the
 183    macros freely, and know that they will come into play for the
 184    version of gcc in which they are supported.  */
 185
 186 #if (GCC_VERSION < 2007)
 187 # define __attribute__(x)
 188 #endif
 189
 190 /* Attribute __malloc__ on functions was valid as of gcc 2.96. */
 191 #ifndef ATTRIBUTE_MALLOC
 192 # if (GCC_VERSION >= 2096)
 193 #  define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
 194 # else
 195 #  define ATTRIBUTE_MALLOC
 196 # endif /* GNUC >= 2.96 */
 197 #endif /* ATTRIBUTE_MALLOC */
 198
 199 /* Attributes on labels were valid as of gcc 2.93. */
 200 #ifndef ATTRIBUTE_UNUSED_LABEL
 201 # if (GCC_VERSION >= 2093)
 202 #  define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED
 203 # else
 204 #  define ATTRIBUTE_UNUSED_LABEL
 205 # endif /* GNUC >= 2.93 */
 206 #endif /* ATTRIBUTE_UNUSED_LABEL */
 207
 208 #ifndef ATTRIBUTE_UNUSED
 209 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
 210 #endif /* ATTRIBUTE_UNUSED */
 211
 212 #ifndef ATTRIBUTE_NORETURN
 213 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
 214 #endif /* ATTRIBUTE_NORETURN */
 215
 216 #ifndef ATTRIBUTE_PRINTF
 217 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
 218 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
 219 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
 220 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
 221 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
 222 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
 223 #endif /* ATTRIBUTE_PRINTF */
 224
 225 /* We use __extension__ in some places to suppress -pedantic warnings
 226    about GCC extensions.  This feature didn't work properly before
 227    gcc 2.8.  */
 228 #if GCC_VERSION < 2008
 229 #define __extension__
 230 #endif
 231
 232 /* Bootstrap support: Autoconf will possibly define the `inline' or
 233    `const' keywords as macros, however this is only valid for the
 234    stage1 compiler.  If we detect a modern version of gcc,
 235    unconditionally reset the values.  This makes sure the right thing
 236    happens in stage2 and later.  We need to do this very early;
 237    i.e. before any header files that might use these keywords.
 238    Otherwise conflicts might occur.  */
 239
 240 #if (GCC_VERSION >= 2007)
 241 # ifdef __STDC__
 242 #  undef const
 243 # endif
 244 # undef inline
 245 # define inline __inline__  /* __inline__ prevents -pedantic warnings */
 246 # ifndef HAVE_LONG_DOUBLE
 247 #  define HAVE_LONG_DOUBLE 1
 248 # endif
 249 #endif /* GCC >= 2.7 */
 250
 251 #endif  /* ansidecl.h   */