gstddef.h

早期freebsd实现

#ifndef _STDDEF_H
#ifndef _STDDEF_H_
#ifndef _ANSI_STDDEF_H

/* Any one of these symbols __need_* means that GNU libc
   wants us just to define one data type.  So don't define
   the symbols that indicate this file's entire job has been done.  */
#if (!defined(__need_wchar_t) && !defined(__need_size_t)	\
     && !defined(__need_ptrdiff_t) && !defined(__need_NULL))
#define _STDDEF_H
#define _STDDEF_H_
/* [e-mail] says the NeXT needs this.  */
#define _ANSI_STDDEF_H
#endif

#ifndef __sys_stdtypes_h
/* This avoids lossage on SunOS but only if stdtypes.h comes first.
   There's no way to win with the other order!  Sun lossage.  */

/* On 4.3bsd-net2, make sure ansi.h is included, so we have
   one less case to deal with in the following.  */
/* #if defined (__BSD_NET2__) || defined (____386BSD____)*/
#include <machine/ansi.h>
/* #endif*/

/* In 4.3bsd-net2, machine/ansi.h defines these symbols, which are
    defined if the corresponding type is *not* defined.  */
#ifdef _ANSI_H_
#ifndef _SIZE_T_
#define _SIZE_T
#endif
#ifndef _PTRDIFF_T_
#define _PTRDIFF_T
#endif
#ifndef _WCHAR_T_
#define _WCHAR_T
#endif
#undef _PTRDIFF_T_
#ifndef __need_ptrdiff_t
#undef _SIZE_T_
#undef _WCHAR_T_
#endif
#endif /* _ANSI_H_ */

/* In case nobody has defined these types, but we aren't running under
   GCC 2.00, make sure that __PTRDIFF_TYPE__, __SIZE__TYPE__, and
   __WCHAR_TYPE__ have reasonable values.  This can happen if the
   parts of GCC is compiled by an older compiler, that actually
   include gstddef.h, such as collect2.  */

/* Signed type of difference of two pointers.  */

/* Define this type if we are doing the whole job,
   or if we want this type in particular.  */
#if defined (_STDDEF_H) || defined (__need_ptrdiff_t)
#ifndef _PTRDIFF_T	/* in case <sys/types.h> has defined it. */
#ifndef _T_PTRDIFF_
#ifndef _T_PTRDIFF
#ifndef __PTRDIFF_T
#ifndef _PTRDIFF_T_
#ifndef ___int_ptrdiff_t_h
#ifndef _GCC_PTRDIFF_T
#define _PTRDIFF_T
#define _T_PTRDIFF_
#define _T_PTRDIFF
#define __PTRDIFF_T
#define _PTRDIFF_T_
#define ___int_ptrdiff_t_h
#define _GCC_PTRDIFF_T
#ifndef __PTRDIFF_TYPE__
#define __PTRDIFF_TYPE__ long int
#endif
typedef __PTRDIFF_TYPE__ ptrdiff_t;
#endif /* _GCC_PTRDIFF_T */
#endif /* ___int_ptrdiff_t_h */
#endif /* _PTRDIFF_T_ */
#endif /* __PTRDIFF_T */
#endif /* _T_PTRDIFF */
#endif /* _T_PTRDIFF_ */
#endif /* _PTRDIFF_T */

/* If this symbol has done its job, get rid of it.  */
#undef	__need_ptrdiff_t

#endif /* _STDDEF_H or __need_ptrdiff_t.  */

/* Unsigned type of `sizeof' something.  */

/* Define this type if we are doing the whole job,
   or if we want this type in particular.  */
#if defined (_STDDEF_H) || defined (__need_size_t)
#ifndef _SIZE_T	/* in case <sys/types.h> has defined it. */
#ifndef _T_SIZE_
#ifndef _T_SIZE
#ifndef __SIZE_T
#ifndef _SIZE_T_
#ifndef ___int_size_t_h
#ifndef _GCC_SIZE_T
#ifndef _SIZET_
#define _SIZE_T
#define _T_SIZE_
#define _T_SIZE
#define __SIZE_T
#define _SIZE_T_
#define ___int_size_t_h
#define _GCC_SIZE_T
#define _SIZET_
#ifndef __SIZE_TYPE__
#define __SIZE_TYPE__ long unsigned int
#endif
typedef __SIZE_TYPE__ size_t;
#endif /* _SIZET_ */
#endif /* _GCC_SIZE_T */
#endif /* ___int_size_t_h */
#endif /* _SIZE_T_ */
#endif /* __SIZE_T */
#endif /* _T_SIZE */
#endif /* _T_SIZE_ */
#endif /* _SIZE_T */
#undef	__need_size_t
#endif /* _STDDEF_H or __need_size_t.  */


/* Wide character type.
   Locale-writers should change this as necessary to
   be big enough to hold unique values not between 0 and 127,
   and not (wchar_t) -1, for each defined multibyte character.  */

/* Define this type if we are doing the whole job,
   or if we want this type in particular.  */
#if defined (_STDDEF_H) || defined (__need_wchar_t)
#ifndef _WCHAR_T
#ifndef _T_WCHAR_
#ifndef _T_WCHAR
#ifndef __WCHAR_T
#ifndef _WCHAR_T_
#ifndef ___int_wchar_t_h
#ifndef _GCC_WCHAR_T
#define _WCHAR_T
#define _T_WCHAR_
#define _T_WCHAR
#define __WCHAR_T
#define _WCHAR_T_
#define ___int_wchar_t_h
#define _GCC_WCHAR_T
#ifndef __WCHAR_TYPE__
#define __WCHAR_TYPE__ int
#endif
#ifdef __GNUG__
/* In C++, wchar_t is a distinct basic type,
   and we can expect __wchar_t to be defined by cc1plus.  */
typedef __wchar_t wchar_t;
#else
/* In C, cpp tells us which type to make an alias for.  */
typedef __WCHAR_TYPE__ wchar_t;
#endif
#endif
#endif
#endif
#endif
#endif
#endif
#endif
#undef	__need_wchar_t
#endif /* _STDDEF_H or __need_wchar_t.  */

/*  In 4.3bsd-net2, leave these undefined to indicate that size_t, etc.
    are already defined.  We need not worry about the case of wanting just
    one of these types, not on 4.3bsd-net2, because only the GNU libc
    header files do that.  */
#ifdef _ANSI_H_
#undef _PTRDIFF_T_
#ifdef _STDDEF_H /* This is a kludge.
		    _STDDEF_H is defined when we are using the whole file,
		    undefined when obstack.h wants just ptrdiff_t.  */
#undef _SIZE_T_
#undef _WCHAR_T_
#endif
#endif

#endif /* __sys_stdtypes_h */

/* A null pointer constant.  */

#if defined (_STDDEF_H) || defined (__need_NULL)
#undef NULL		/* in case <stdio.h> has defined it. */
#define NULL ((void *)0)
#endif	/* NULL not defined and <stddef.h> or need NULL.  */
#undef	__need_NULL

#ifdef _STDDEF_H

/* Offset of member MEMBER in a struct of type TYPE.  */

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

#endif /* _STDDEF_H was defined this time */

#endif /* _ANSI_STDDEF_H was not defined before */
#endif /* _STDDEF_H_ was not defined before */
#endif /* _STDDEF_H was not defined before */