glibc/libio/bits/stdio.h

/* Optimizing macros and inline functions for stdio functions.
   Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _STDIO_H
# error "Never include <bits/stdio.h> directly; use <stdio.h> instead."
#endif

#ifdef __cplusplus
# define __STDIO_INLINE inline
#else
# define __STDIO_INLINE extern __inline
#endif


#ifdef __USE_EXTERN_INLINES
/* Since version 2.97 GCC knows about `fprintf' and can optimize certain
   cases.  Help gcc to optimize more code by mapping `printf' to the known
   `fprintf' function.  Unfortunately we have to use a macro.  */
# if __GNUC_PREREQ (2,97)
#  define printf(fmt, args...) fprintf (stdout, fmt, ##args)
# endif

/* Write formatted output to stdout from argument list ARG.  */
__STDIO_INLINE int
vprintf (__const char *__restrict __fmt, _G_va_list __arg) __THROW
{
  return vfprintf (stdout, __fmt, __arg);
}

/* Read a character from stdin.  */
__STDIO_INLINE int
getchar (void) __THROW
{
  return _IO_getc (stdin);
}


# if defined __USE_POSIX || defined __USE_MISC
/* This is defined in POSIX.1:1996.  */
__STDIO_INLINE int
getc_unlocked (FILE *__fp) __THROW
{
  return _IO_getc_unlocked (__fp);
}

/* This is defined in POSIX.1:1996.  */
__STDIO_INLINE int
getchar_unlocked (void) __THROW
{
  return _IO_getc_unlocked (stdin);
}
# endif	/* POSIX || misc */


/* Write a character to stdout.  */
__STDIO_INLINE int
putchar (int __c) __THROW
{
  return _IO_putc (__c, stdout);
}


# ifdef __USE_MISC
/* Faster version when locking is not necessary.  */
__STDIO_INLINE int
fputc_unlocked (int __c, FILE *__stream) __THROW
{
  return _IO_putc_unlocked (__c, __stream);
}
# endif /* misc */


# if defined __USE_POSIX || defined __USE_MISC
/* This is defined in POSIX.1:1996.  */
__STDIO_INLINE int
putc_unlocked (int __c, FILE *__stream) __THROW
{
  return _IO_putc_unlocked (__c, __stream);
}

/* This is defined in POSIX.1:1996.  */
__STDIO_INLINE int
putchar_unlocked (int __c) __THROW
{
  return _IO_putc_unlocked (__c, stdout);
}
# endif	/* POSIX || misc */


# ifdef	__USE_GNU
/* Like `getdelim', but reads up to a newline.  */
__STDIO_INLINE _IO_ssize_t
getline (char **__lineptr, size_t *__n, FILE *__stream) __THROW
{
  return __getdelim (__lineptr, __n, '\n', __stream);
}
# endif /* GNU */


# ifdef __USE_MISC
/* Faster versions when locking is not required.  */
__STDIO_INLINE int
feof_unlocked (FILE *__stream) __THROW
{
  return _IO_feof_unlocked (__stream);
}

/* Faster versions when locking is not required.  */
__STDIO_INLINE int
ferror_unlocked (FILE *__stream) __THROW
{
  return _IO_ferror_unlocked (__stream);
}
# endif /* misc */

#endif /* Use extern inlines.  */


#if defined __USE_MISC && defined __GNUC__ && defined __OPTIMIZE__
/* Perform some simple optimizations.  */
# define fread_unlocked(ptr, size, n, stream) \
  (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n)    \
		   && (size_t) ((size) * (n)) <= 8 && (size) != 0)	      \
		  ? ({ char *__ptr = (char *) (ptr);			      \
		       FILE *__stream = (stream);			      \
		       size_t __cnt;					      \
		       for (__cnt = (size) * (n); __cnt > 0; --__cnt)	      \
			 {						      \
			   int __c = _IO_getc_unlocked (__stream);	      \
			   if (__c == EOF)				      \
			     break;					      \
			   *__ptr++ = __c;				      \
			 }						      \
		       ((size_t) ((size) * (n)) - __cnt) / (size); })	      \
		  : (((__builtin_constant_p (size) && (size) == 0)	      \
		      || (__builtin_constant_p (n) && (n) == 0))	      \
			/* Evaluate all parameters once.  */		      \
		     ? ((void) (ptr), (void) (stream), (void) (size),	      \
			(void) (n), 0)					      \
		     : fread_unlocked (ptr, size, n, stream))))

# define fwrite_unlocked(ptr, size, n, stream) \
  (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n)    \
		   && (size_t) ((size) * (n)) <= 8 && (size) != 0)	      \
		  ? ({ const char *__ptr = (const char *) (ptr);	      \
		       FILE *__stream = (stream);			      \
		       size_t __cnt;					      \
		       for (__cnt = (size) * (n); __cnt > 0; --__cnt)	      \
			 if (_IO_putc_unlocked (*__ptr++, __stream) == EOF)   \
			   break;					      \
		       ((size_t) ((size) * (n)) - __cnt) / (size); })	      \
		  : (((__builtin_constant_p (size) && (size) == 0)	      \
		      || (__builtin_constant_p (n) && (n) == 0))	      \
			/* Evaluate all parameters once.  */		      \
		     ? ((void) (ptr), (void) (stream), (void) (size), n)      \
		     : fwrite_unlocked (ptr, size, n, stream))))
#endif

/* Define helper macro.  */
#undef __STDIO_INLINE