GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libc/stdio/setvbuf.c Lines: 0 49 0.0 %
Date: 2017-11-07 Branches: 0 44 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: setvbuf.c,v 1.14 2016/09/21 04:38:56 guenther Exp $ */
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/*-
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 * Copyright (c) 1990, 1993
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 *	The Regents of the University of California.  All rights reserved.
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 *
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 * This code is derived from software contributed to Berkeley by
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 * Chris Torek.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include "local.h"
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/*
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 * Set one of the three kinds of buffering, optionally including
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 * a buffer.
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 */
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int
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setvbuf(FILE *fp, char *buf, int mode, size_t size)
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{
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	int ret, flags;
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	size_t iosize;
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	int ttyflag;
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	/*
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	 * Verify arguments.  The `int' limit on `size' is due to this
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	 * particular implementation.  Note, buf and size are ignored
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	 * when setting _IONBF.
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	 */
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	if (mode != _IONBF)
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		if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0)
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			return (EOF);
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	/*
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	 * Write current buffer, if any.  Discard unread input (including
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	 * ungetc data), cancel line buffering, and free old buffer if
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	 * malloc()ed.  We also clear any eof condition, as if this were
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	 * a seek.
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	 */
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	FLOCKFILE(fp);
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	ret = 0;
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	(void)__sflush(fp);
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	if (HASUB(fp))
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		FREEUB(fp);
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	WCIO_FREE(fp);
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	fp->_r = fp->_lbfsize = 0;
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	flags = fp->_flags;
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	if (flags & __SMBF)
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		free(fp->_bf._base);
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	flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SNPT | __SEOF);
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	/* If setting unbuffered mode, skip all the hard work. */
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	if (mode == _IONBF)
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		goto nbf;
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	/*
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	 * Find optimal I/O size for seek optimization.  This also returns
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	 * a `tty flag' to suggest that we check isatty(fd), but we do not
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	 * care since our caller told us how to buffer.
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	 */
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	flags |= __swhatbuf(fp, &iosize, &ttyflag);
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	if (size == 0) {
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		buf = NULL;	/* force local allocation */
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		size = iosize;
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	}
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	/* Allocate buffer if needed. */
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	if (buf == NULL) {
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		if ((buf = malloc(size)) == NULL) {
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			/*
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			 * Unable to honor user's request.  We will return
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			 * failure, but try again with file system size.
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			 */
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			ret = EOF;
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			if (size != iosize) {
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				size = iosize;
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				buf = malloc(size);
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			}
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		}
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		if (buf == NULL) {
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			/* No luck; switch to unbuffered I/O. */
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nbf:
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			fp->_flags = flags | __SNBF;
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			fp->_w = 0;
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			fp->_bf._base = fp->_p = fp->_nbuf;
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			fp->_bf._size = 1;
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			FUNLOCKFILE(fp);
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			return (ret);
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		}
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		flags |= __SMBF;
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	}
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	/*
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	 * We're committed to buffering from here, so make sure we've
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	 * registered to flush buffers on exit.
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	 */
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	if (!__sdidinit)
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		__sinit();
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	/*
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	 * Kill any seek optimization if the buffer is not the
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	 * right size.
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	 *
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	 * SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)?
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	 */
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	if (size != iosize)
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		flags |= __SNPT;
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	/*
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	 * Fix up the FILE fields, and set __cleanup for output flush on
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	 * exit (since we are buffered in some way).
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	 */
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	if (mode == _IOLBF)
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		flags |= __SLBF;
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	fp->_flags = flags;
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	fp->_bf._base = fp->_p = (unsigned char *)buf;
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	fp->_bf._size = size;
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	/* fp->_lbfsize is still 0 */
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	if (flags & __SWR) {
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		/*
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		 * Begin or continue writing: see __swsetup().  Note
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		 * that __SNBF is impossible (it was handled earlier).
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		 */
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		if (flags & __SLBF) {
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			fp->_w = 0;
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			fp->_lbfsize = -fp->_bf._size;
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		} else
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			fp->_w = size;
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	} else {
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		/* begin/continue reading, or stay in intermediate state */
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		fp->_w = 0;
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	}
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	FUNLOCKFILE(fp);
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	return (ret);
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}
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DEF_STRONG(setvbuf);