minix/include/ansi.h

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2005-04-21 16:53:53 +02:00
/* The <ansi.h> header attempts to decide whether the compiler has enough
* conformance to Standard C for Minix to take advantage of. If so, the
* symbol _ANSI is defined (as 31415). Otherwise _ANSI is not defined
* here, but it may be defined by applications that want to bend the rules.
* The magic number in the definition is to inhibit unnecessary bending
* of the rules. (For consistency with the new '#ifdef _ANSI" tests in
* the headers, _ANSI should really be defined as nothing, but that would
* break many library routines that use "#if _ANSI".)
* If _ANSI ends up being defined, a macro
*
* _PROTOTYPE(function, params)
*
* is defined. This macro expands in different ways, generating either
* ANSI Standard C prototypes or old-style K&R (Kernighan & Ritchie)
* prototypes, as needed. Finally, some programs use _CONST, _VOIDSTAR etc
* in such a way that they are portable over both ANSI and K&R compilers.
* The appropriate macros are defined here.
*/
#ifndef _ANSI_H
#define _ANSI_H
#if __STDC__ == 1
#define _ANSI 31459 /* compiler claims full ANSI conformance */
#endif
#ifdef __GNUC__
#define _ANSI 31459 /* gcc conforms enough even in non-ANSI mode */
#endif
#ifdef _ANSI
/* Keep everything for ANSI prototypes. */
#define _PROTOTYPE(function, params) function params
#define _ARGS(params) params
#define _VOIDSTAR void *
#define _VOID void
#define _CONST const
#define _VOLATILE volatile
#define _SIZET size_t
#else
/* Throw away the parameters for K&R prototypes. */
#define _PROTOTYPE(function, params) function()
#define _ARGS(params) ()
#define _VOIDSTAR void *
#define _VOID void
#define _CONST
#define _VOLATILE
#define _SIZET int
#endif /* _ANSI */
/* Setting any of _MINIX, _POSIX_C_SOURCE or _POSIX2_SOURCE implies
* _POSIX_SOURCE. (Seems wrong to put this here in ANSI space.)
*/
#if defined(_MINIX) || _POSIX_C_SOURCE > 0 || defined(_POSIX2_SOURCE)
#undef _POSIX_SOURCE
#define _POSIX_SOURCE 1
#endif
#endif /* ANSI_H */