/* Specification. */
#include "freadahead.h"
+#include "stdio-impl.h"
+
size_t
freadahead (FILE *fp)
{
-#if defined _IO_ferror_unlocked /* GNU libc, BeOS */
+#if defined _IO_ferror_unlocked || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Linux libc5 */
if (fp->_IO_write_ptr > fp->_IO_write_base)
return 0;
return (fp->_IO_read_end - fp->_IO_read_ptr)
+ (fp->_flags & _IO_IN_BACKUP ? fp->_IO_save_end - fp->_IO_save_base :
0);
-#elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
-# if defined __NetBSD__ || defined __OpenBSD__
- struct __sfileext
- {
- struct __sbuf _ub; /* ungetc buffer */
- /* More fields, not relevant here. */
- };
-# define HASUB(fp) (((struct __sfileext *) (fp)->_ext._base)->_ub._base != NULL)
+#elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
+ if ((fp_->_flags & __SWR) != 0 || fp_->_r < 0)
+ return 0;
+# if defined __DragonFly__
+ return __sreadahead (fp);
# else
-# define HASUB(fp) ((fp)->_ub._base != NULL)
+ return fp_->_r
+ + (HASUB (fp) ? fp_->_ur : 0);
# endif
- if ((fp->_flags & __SWR) != 0 || fp->_r < 0)
+#elif defined __EMX__ /* emx+gcc */
+ if ((fp->_flags & _IOWRT) != 0)
return 0;
- return fp->_r
- + (HASUB (fp) ? fp->_ur : 0);
+ /* Note: fp->_ungetc_count > 0 implies fp->_rcount <= 0,
+ fp->_ungetc_count = 0 implies fp->_rcount >= 0. */
+ /* equivalent to
+ (fp->_ungetc_count == 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount) */
+ return (fp->_rcount > 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount);
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */
-# if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
-# define fp_ ((struct { unsigned char *_ptr; \
- unsigned char *_base; \
- unsigned char *_end; \
- long _cnt; \
- int _file; \
- unsigned int _flag; \
- } *) fp)
if ((fp_->_flag & _IOWRT) != 0)
return 0;
return fp_->_cnt;
-# else
-# if defined _SCO_DS /* OpenServer */
-# define _flag __flag
-# define _cnt __cnt
-# endif
- if ((fp->_flag & _IOWRT) != 0)
- return 0;
- return fp->_cnt;
-# endif
#elif defined __UCLIBC__ /* uClibc */
# ifdef __STDIO_BUFFERS
if (fp->__modeflags & __FLAG_WRITING)