Re: [PATCH] Fix wide stdio

[Jakub Jelinek <jakub@redhat.com>]

On Mon, Nov 27, 2006 at 07:13:34AM -0800, Ulrich Drepper wrote:
> Jakub Jelinek wrote:
> >I'd like to understand what's still screwed up big time after the patch
> >I posted.
> 
> Any buffer provided must be associated with the wide char buffer for 
> wide streams, not the underlying temporary buffer.  This requires, if 
> setvbuf is called before the decision is made, to move the buffer from 
> being used in the output buffer to being used as the wide char buffer. 
> Along with handling alignment issues etc this is a terribly complex change.

This updated patch should handle that.  It doesn't really swap the buffers
(which is not necessary IMHO, no app should care about that), just sizes
the wide buffer the same as how big the setvbuf buffer is.  If setvbuf has
not been called (and the narrow buffer is therefore libio allocated,
not user allocated), it preserves the old behavior where the wide buffer
has been sizeof (wchar_t) times bigger than the narrow buffer.

It also fixes a bug where
f = fopen ("/dev/tty", "w"); setvbuf (f, buf, _IOFBF, len); fwprintf (f, L"something");
would not honor the full buffered request, _IO_wfile_doallocate used
to override it to line buffered.  Also, one unneeded stat has been removed.

2006-12-08  Jakub Jelinek  <jakub@redhat.com>

	* libio/genops.c (__uflow): Fix a typo.
	* libio/wfiledoalloc.c (_IO_wfile_doallocate): Don't stat
	nor set _IO_LINE_BUF bit here.  Size the wide buffer based on
	the narrow buffer size.

2006-11-24  Jakub Jelinek  <jakub@redhat.com>

	* libio/libio.h (_IO_FLAGS2_USER_WBUF): Define.
	* libio/wgenops.c (_IO_wsetb, _IO_wdefault_finish): Test and set
	_IO_FLAGS2_USER_WBUF bit in _flags2 instead of _IO_USER_BUF bit
	in _flags.
	* libio/wstrops.c (_IO_wstr_overflow, enlarge_userbuf,
	_IO_wstr_finish): Likewise.
	* libio/wmemstream.c (open_wmemstream): Likewise.
	* libio/fileops.c (_IO_new_file_close_it): Call _IO_set[bgp]
	even for wide streams.

--- libc/libio/fileops.c	19 Jan 2006 00:38:35 -0000	1.110
+++ libc/libio/fileops.c	5 Dec 2006 15:39:22 -0000
@@ -174,14 +174,8 @@ _IO_new_file_close_it (fp)
   close_status = _IO_SYSCLOSE (fp);
 
   /* Free buffer. */
-  if (fp->_mode <= 0)
-    {
-      INTUSE(_IO_setb) (fp, NULL, NULL, 0);
-      _IO_setg (fp, NULL, NULL, NULL);
-      _IO_setp (fp, NULL, NULL);
-    }
 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
-  else
+  if (fp->_mode > 0)
     {
       if (_IO_have_wbackup (fp))
 	INTUSE(_IO_free_wbackup_area) (fp);
@@ -190,6 +184,9 @@ _IO_new_file_close_it (fp)
       _IO_wsetp (fp, NULL, NULL);
     }
 #endif
+  INTUSE(_IO_setb) (fp, NULL, NULL, 0);
+  _IO_setg (fp, NULL, NULL, NULL);
+  _IO_setp (fp, NULL, NULL);
 
   INTUSE(_IO_un_link) ((struct _IO_FILE_plus *) fp);
   fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
--- libc/libio/genops.c	1 Mar 2006 05:32:48 -0000	1.70
+++ libc/libio/genops.c	5 Dec 2006 15:39:22 -0000
@@ -367,7 +367,7 @@ __uflow (fp)
 #endif
 
   if (fp->_mode == 0)
-    _IO_fwide (fp, -11);
+    _IO_fwide (fp, -1);
   if (_IO_in_put_mode (fp))
     if (INTUSE(_IO_switch_to_get_mode) (fp) == EOF)
       return EOF;
--- libc/libio/libio.h	14 Jan 2006 12:09:46 -0000	1.64
+++ libc/libio/libio.h	5 Dec 2006 15:39:22 -0000
@@ -142,6 +142,7 @@
 #ifdef _LIBC
 # define _IO_FLAGS2_FORTIFY 4
 #endif
+#define _IO_FLAGS2_USER_WBUF 8
 
 /* These are "formatting flags" matching the iostream fmtflags enum values. */
 #define _IO_SKIPWS 01
--- libc/libio/wfiledoalloc.c	6 Jul 2002 06:35:54 -0000	1.6
+++ libc/libio/wfiledoalloc.c	5 Dec 2006 15:39:22 -0000
@@ -1,4 +1,5 @@
-/* Copyright (C) 1993, 1997, 1999, 2000, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1993, 1997, 1999, 2000, 2002, 2006
+   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
@@ -85,35 +86,20 @@ _IO_wfile_doallocate (fp)
      _IO_FILE *fp;
 {
   _IO_size_t size;
-  int couldbetty;
   wchar_t *p;
-  struct _G_stat64 st;
 
   /* Allocate room for the external buffer.  */
   if (fp->_IO_buf_base == NULL)
     INTUSE(_IO_file_doallocate) (fp);
 
-  if (fp->_fileno < 0 || _IO_SYSSTAT (fp, &st) < 0)
-    {
-      couldbetty = 0;
-      size = _IO_BUFSIZ;
-#if 0
-      /* do not try to optimise fseek() */
-      fp->_flags |= __SNPT;
-#endif
-    }
-  else
-    {
-      couldbetty = S_ISCHR (st.st_mode);
-#if _IO_HAVE_ST_BLKSIZE
-      size = st.st_blksize <= 0 ? _IO_BUFSIZ : st.st_blksize;
-#else
-      size = _IO_BUFSIZ;
-#endif
-    }
+  /* If narrow buffer is user allocated (set by setvbuf etc.),
+     use that size as the size of the wide buffer, when it is
+     allocated by _IO_file_doallocate, multiply that by size
+     of the wide character.  */
+  size = fp->_IO_buf_end - fp->_IO_buf_base;
+  if ((fp->_flags & _IO_USER_BUF))
+    size = (size + sizeof (wchar_t) - 1) / sizeof (wchar_t);
   ALLOC_WBUF (p, size * sizeof (wchar_t), EOF);
   INTUSE(_IO_wsetb) (fp, p, p + size, 1);
-  if (couldbetty && isatty (fp->_fileno))
-    fp->_flags |= _IO_LINE_BUF;
   return 1;
 }
--- libc/libio/wgenops.c	12 Feb 2006 21:20:57 -0000	1.14
+++ libc/libio/wgenops.c	5 Dec 2006 15:39:22 -0000
@@ -115,14 +115,14 @@ _IO_wsetb (f, b, eb, a)
      wchar_t *eb;
      int a;
 {
-  if (f->_wide_data->_IO_buf_base && !(f->_flags & _IO_USER_BUF))
+  if (f->_wide_data->_IO_buf_base && !(f->_flags2 & _IO_FLAGS2_USER_WBUF))
     FREE_BUF (f->_wide_data->_IO_buf_base, _IO_wblen (f) * sizeof (wchar_t));
   f->_wide_data->_IO_buf_base = b;
   f->_wide_data->_IO_buf_end = eb;
   if (a)
-    f->_flags &= ~_IO_USER_BUF;
+    f->_flags2 &= ~_IO_FLAGS2_USER_WBUF;
   else
-    f->_flags |= _IO_USER_BUF;
+    f->_flags2 |= _IO_FLAGS2_USER_WBUF;
 }
 INTDEF(_IO_wsetb)
 
@@ -198,7 +198,7 @@ _IO_wdefault_finish (fp, dummy)
      int dummy;
 {
   struct _IO_marker *mark;
-  if (fp->_wide_data->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
+  if (fp->_wide_data->_IO_buf_base && !(fp->_flags2 & _IO_FLAGS2_USER_WBUF))
     {
       FREE_BUF (fp->_wide_data->_IO_buf_base,
 		_IO_wblen (fp) * sizeof (wchar_t));
--- libc/libio/wmemstream.c	30 Sep 2006 00:06:33 -0000	1.3
+++ libc/libio/wmemstream.c	5 Dec 2006 15:39:22 -0000
@@ -92,7 +92,7 @@ open_wmemstream (bufloc, sizeloc)
   _IO_fwide (&new_f->fp._sf._sbf._f, 1);
   _IO_wstr_init_static (&new_f->fp._sf._sbf._f, buf,
 			_IO_BUFSIZ / sizeof (wchar_t), buf);
-  new_f->fp._sf._sbf._f._flags &= ~_IO_USER_BUF;
+  new_f->fp._sf._sbf._f._flags2 &= ~_IO_FLAGS2_USER_WBUF;
   new_f->fp._sf._s._allocate_buffer = (_IO_alloc_type) malloc;
   new_f->fp._sf._s._free_buffer = (_IO_free_type) free;
 
--- libc/libio/wstrops.c	14 Aug 2006 22:14:53 -0000	1.11
+++ libc/libio/wstrops.c	5 Dec 2006 15:39:22 -0000
@@ -88,7 +88,7 @@ _IO_wstr_overflow (fp, c)
   pos = fp->_wide_data->_IO_write_ptr - fp->_wide_data->_IO_write_base;
   if (pos >= (_IO_size_t) (_IO_wblen (fp) + flush_only))
     {
-      if (fp->_flags & _IO_USER_BUF) /* not allowed to enlarge */
+      if (fp->_flags2 & _IO_FLAGS2_USER_WBUF) /* not allowed to enlarge */
 	return WEOF;
       else
 	{
@@ -182,7 +182,7 @@ enlarge_userbuf (_IO_FILE *fp, _IO_off64
   _IO_ssize_t oldend = wd->_IO_write_end - wd->_IO_write_base;
 
   /* Try to enlarge the buffer.  */
-  if (fp->_flags & _IO_USER_BUF)
+  if (fp->_flags2 & _IO_FLAGS2_USER_WBUF)
     /* User-provided buffer.  */
     return 1;
 
@@ -335,7 +335,7 @@ _IO_wstr_finish (fp, dummy)
      _IO_FILE *fp;
      int dummy;
 {
-  if (fp->_wide_data->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
+  if (fp->_wide_data->_IO_buf_base && !(fp->_flags2 & _IO_FLAGS2_USER_WBUF))
     (((_IO_strfile *) fp)->_s._free_buffer) (fp->_wide_data->_IO_buf_base);
   fp->_wide_data->_IO_buf_base = NULL;
 


	Jakub