Add __swhatbuf function from OpenBSD

To fix a long-standing setvbuf bug, import __swhatbuf function from
OpenBSD and only slightly rearrange for newlib.

	* libc/stdio/local.h (__swhatbuf_r): Declare.
	* libc/stdio/makebuf (__smakebuf_r): New function.
	(__smakebuf_r): Drop file handling code and call __smakebuf_r.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This commit is contained in:
Corinna Vinschen 2016-03-12 23:37:01 +01:00
parent 6b97fabf1b
commit 99d0e2341d
2 changed files with 60 additions and 49 deletions

View File

@ -182,6 +182,7 @@ extern int _EXFUN(__stextmode,(int));
extern _VOID _EXFUN(__sinit,(struct _reent *));
extern _VOID _EXFUN(_cleanup_r,(struct _reent *));
extern _VOID _EXFUN(__smakebuf_r,(struct _reent *, FILE *));
extern int _EXFUN(__swhatbuf_r,(struct _reent *, FILE *, size_t *, int *));
extern int _EXFUN(_fwalk,(struct _reent *, int (*)(FILE *)));
extern int _EXFUN(_fwalk_reent,(struct _reent *, int (*)(struct _reent *, FILE *)));
struct _glue * _EXFUN(__sfmoreglue,(struct _reent *,int n));

View File

@ -39,13 +39,10 @@ _DEFUN(__smakebuf_r, (ptr, fp),
struct _reent *ptr _AND
register FILE *fp)
{
register size_t size, couldbetty;
register _PTR p;
#ifdef __USE_INTERNAL_STAT64
struct stat64 st;
#else
struct stat st;
#endif
int flags;
size_t size;
int couldbetty;
if (fp->_flags & __SNBF)
{
@ -53,49 +50,7 @@ _DEFUN(__smakebuf_r, (ptr, fp),
fp->_bf._size = 1;
return;
}
#ifdef __USE_INTERNAL_STAT64
if (fp->_file < 0 || _fstat64_r (ptr, fp->_file, &st) < 0)
#else
if (fp->_file < 0 || _fstat_r (ptr, fp->_file, &st) < 0)
#endif
{
couldbetty = 0;
/* Check if we are be called by asprintf family for initial buffer. */
if (fp->_flags & __SMBF)
size = _DEFAULT_ASPRINTF_BUFSIZE;
else
size = BUFSIZ;
#ifdef _FSEEK_OPTIMIZATION
/* do not try to optimise fseek() */
fp->_flags |= __SNPT;
#endif
}
else
{
couldbetty = (st.st_mode & S_IFMT) == S_IFCHR;
#ifdef HAVE_BLKSIZE
size = st.st_blksize <= 0 ? BUFSIZ : st.st_blksize;
#else
size = BUFSIZ;
#endif
#ifdef _FSEEK_OPTIMIZATION
/*
* Optimize fseek() only if it is a regular file.
* (The test for __sseek is mainly paranoia.)
*/
if ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek)
{
fp->_flags |= __SOPT;
#ifdef HAVE_BLKSIZE
fp->_blksize = st.st_blksize;
#else
fp->_blksize = 1024;
#endif
}
else
fp->_flags |= __SNPT;
#endif
}
flags = __swhatbuf_r (ptr, fp, &size, &couldbetty);
if ((p = _malloc_r (ptr, size)) == NULL)
{
if (!(fp->_flags & __SSTR))
@ -113,5 +68,60 @@ _DEFUN(__smakebuf_r, (ptr, fp),
fp->_bf._size = size;
if (couldbetty && _isatty_r (ptr, fp->_file))
fp->_flags |= __SLBF;
fp->_flags |= flags;
}
}
/*
* Internal routine to determine `proper' buffering for a file.
*/
int
_DEFUN(__swhatbuf_r, (ptr, fp, bufsize, couldbetty),
struct _reent *ptr _AND
FILE *fp _AND
size_t *bufsize _AND
int *couldbetty)
{
#ifdef _FSEEK_OPTIMIZATION
const int snpt = __SNPT;
#else
const int snpt = 0;
#endif
#ifdef __USE_INTERNAL_STAT64
struct stat64 st;
if (fp->_file < 0 || _fstat64_r (ptr, fp->_file, &st) < 0)
#else
struct stat st;
if (fp->_file < 0 || _fstat_r (ptr, fp->_file, &st) < 0)
#endif
{
*couldbetty = 0;
/* Check if we are be called by asprintf family for initial buffer. */
if (fp->_flags & __SMBF)
*bufsize = _DEFAULT_ASPRINTF_BUFSIZE;
else
*bufsize = BUFSIZ;
return (0);
}
/* could be a tty iff it is a character device */
*couldbetty = S_ISCHR(st.st_mode);
#ifdef HAVE_BLKSIZE
if (st.st_blksize > 0)
{
/*
* Optimise fseek() only if it is a regular file. (The test for
* __sseek is mainly paranoia.) It is safe to set _blksize
* unconditionally; it will only be used if __SOPT is also set.
*/
*bufsize = st.st_blksize;
fp->_blksize = st.st_blksize;
return ((st.st_mode & S_IFMT) == S_IFREG ? __SOPT : snpt);
}
#endif
*bufsize = BUFSIZ;
return (snpt);
}