include/ansi.h

   1 /* The <ansi.h> header attempts to decide whether the compiler has enough
   2  * conformance to Standard C for Minix to take advantage of.  If so, the
   3  * symbol _ANSI is defined (as 31459).  Otherwise _ANSI is not defined
   4  * here, but it may be defined by applications that want to bend the rules.
   5  * The magic number in the definition is to inhibit unnecessary bending
   6  * of the rules.  (For consistency with the new '#ifdef _ANSI" tests in
   7  * the headers, _ANSI should really be defined as nothing, but that would
   8  * break many library routines that use "#if _ANSI".)
   9
  10  * If _ANSI ends up being defined, a macro
  11  *
  12  *      _PROTOTYPE(function, params)
  13  *
  14  * is defined.  This macro expands in different ways, generating either
  15  * ANSI Standard C prototypes or old-style K&R (Kernighan & Ritchie)
  16  * prototypes, as needed.  Finally, some programs use _CONST, _VOIDSTAR etc
  17  * in such a way that they are portable over both ANSI and K&R compilers.
  18  * The appropriate macros are defined here.
  19  */
  20
  21 #ifndef _ANSI_H
  22 #define _ANSI_H
  23
  24 #if __STDC__ == 1
  25 #define _ANSI           31459   /* compiler claims full ANSI conformance */
  26 #endif
  27
  28 #ifdef __GNUC__
  29 #define _ANSI           31459   /* gcc conforms enough even in non-ANSI mode */
  30 #endif
  31
  32 #ifdef _ANSI
  33
  34 /* Keep everything for ANSI prototypes. */
  35 #define _PROTOTYPE(function, params)    function params
  36 #define _ARGS(params)                   params
  37
  38 #define _VOIDSTAR       void *
  39 #define _VOID           void
  40 #define _CONST          const
  41 #define _VOLATILE       volatile
  42 #define _SIZET          size_t
  43
  44 #else
  45
  46 /* Throw away the parameters for K&R prototypes. */
  47 #define _PROTOTYPE(function, params)    function()
  48 #define _ARGS(params)                   ()
  49
  50 #define _VOIDSTAR       void *
  51 #define _VOID           void
  52 #define _CONST
  53 #define _VOLATILE
  54 #define _SIZET          int
  55
  56 #endif /* _ANSI */
  57
  58 /* This should be defined as restrict when a C99 compiler is used. */
  59 #define _RESTRICT
  60
  61 /* Setting any of _MINIX, _POSIX_C_SOURCE or _POSIX2_SOURCE implies
  62  * _POSIX_SOURCE.  (Seems wrong to put this here in ANSI space.)
  63  */
  64 #if defined(_MINIX) || _POSIX_C_SOURCE > 0 || defined(_POSIX2_SOURCE)
  65 #undef _POSIX_SOURCE
  66 #define _POSIX_SOURCE   1
  67 #endif
  68
  69 #endif /* ANSI_H */