GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libc/string/memcpy.c Lines: 15 21 71.4 %
Date: 2017-11-13 Branches: 23 26 88.5 %

Line Branch Exec Source
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/*	$OpenBSD: memcpy.c,v 1.3 2017/08/14 17:10:02 guenther Exp $ */
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/*-
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 * Copyright (c) 1990 The Regents of the University of California.
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 * 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 <string.h>
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#include <stdlib.h>
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#include <syslog.h>
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/*
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 * sizeof(word) MUST BE A POWER OF TWO
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 * SO THAT wmask BELOW IS ALL ONES
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 */
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typedef	long word;		/* "word" used for optimal copy speed */
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#define	wsize	sizeof(word)
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#define	wmask	(wsize - 1)
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static const char backwards_msg[] = ": backwards memcpy";
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/*
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 * Copy a block of memory, not handling overlap.
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 */
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void *
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memcpy(void *dst0, const void *src0, size_t length)
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{
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	char *dst = dst0;
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	const char *src = src0;
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	size_t t;
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13814457
	if (length == 0 || dst == src)		/* nothing to do */
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		goto done;
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9209189
	if ((dst < src && dst + length > src) ||
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4767831
	    (src < dst && src + length > dst)) {
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		char buf[1024];
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		/* <10> is LOG_CRIT */
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		strlcpy(buf, "<10>", sizeof buf);
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		/* Make sure progname does not fill the whole buffer */
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		strlcat(buf, __progname, sizeof(buf) - sizeof backwards_msg);
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		strlcat(buf, backwards_msg, sizeof buf);
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		sendsyslog(buf, strlen(buf), LOG_CONS);
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		abort();
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	}
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	/*
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	 * Macros: loop-t-times; and loop-t-times, t>0
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	 */
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#define	TLOOP(s) if (t) TLOOP1(s)
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#define	TLOOP1(s) do { s; } while (--t)
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	/*
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	 * Copy forward.
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	 */
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4604707
	t = (long)src;	/* only need low bits */
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4604707
	if ((t | (long)dst) & wmask) {
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		/*
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		 * Try to align operands.  This cannot be done
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		 * unless the low bits match.
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		 */
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4324073
		if ((t ^ (long)dst) & wmask || length < wsize)
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4322755
			t = length;
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		else
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1318
			t = wsize - (t & wmask);
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4324073
		length -= t;
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15084095
		TLOOP1(*dst++ = *src++);
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	}
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	/*
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	 * Copy whole words, then mop up any trailing bytes.
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	 */
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4604827
	t = length / wsize;
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5758467
	TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
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4604917
	t = length & wmask;
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5142806
	TLOOP(*dst++ = *src++);
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done:
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4605415
	return (dst0);
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}
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DEF_STRONG(memcpy);