StdLib/LibC/Stdio/wsetup.c

   1 /*
   2     Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
   3     This program and the accompanying materials are licensed and made available
   4     under the terms and conditions of the BSD License that accompanies this
   5     distribution.  The full text of the license may be found at
   6     http://opensource.org/licenses/bsd-license.
   7
   8     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   9     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  10
  11  * Copyright (c) 1990, 1993
  12  *  The Regents of the University of California.  All rights reserved.
  13  *
  14  * This code is derived from software contributed to Berkeley by
  15  * Chris Torek.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  * 3. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40
  41     NetBSD: wsetup.c,v 1.11 2003/08/07 16:43:35 agc Exp
  42     wsetup.c  8.1 (Berkeley) 6/4/93
  43 */
  44 #include  <LibConfig.h>
  45 #include <sys/EfiCdefs.h>
  46
  47 #include <assert.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include "reentrant.h"
  52 #include "local.h"
  53
  54 /*
  55  * Various output routines call wsetup to be sure it is safe to write,
  56  * because either _flags does not include __SWR, or _buf is NULL.
  57  * _wsetup returns 0 if OK to write, nonzero otherwise.
  58  */
  59 int
  60 __swsetup(FILE *fp)
  61 {
  62
  63   _DIAGASSERT(fp != NULL);
  64   if(fp == NULL) {
  65     errno = EINVAL;
  66     return (-1);
  67   }
  68
  69   /* make sure stdio is set up */
  70   if (!__sdidinit)
  71     __sinit();
  72
  73   /*
  74    * If we are not writing, we had better be reading and writing.
  75    */
  76   if ((fp->_flags & __SWR) == 0) {
  77     if ((fp->_flags & __SRW) == 0)
  78       return (EOF);
  79     if (fp->_flags & __SRD) {
  80       /* clobber any ungetc data */
  81       if (HASUB(fp))
  82         FREEUB(fp);
  83       fp->_flags &= ~(__SRD|__SEOF);
  84       fp->_r = 0;
  85       fp->_p = fp->_bf._base;
  86     }
  87     fp->_flags |= __SWR;
  88   }
  89
  90   /*
  91    * Make a buffer if necessary, then set _w.
  92    */
  93   if (fp->_bf._base == NULL)
  94     __smakebuf(fp);
  95   if (fp->_flags & __SLBF) {
  96     /*
  97      * It is line buffered, so make _lbfsize be -_bufsize
  98      * for the putc() macro.  We will change _lbfsize back
  99      * to 0 whenever we turn off __SWR.
 100      */
 101     fp->_w = 0;
 102     fp->_lbfsize = -fp->_bf._size;
 103   } else
 104     fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;
 105   return (0);
 106 }