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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/spell/look.c	Lines:	0	30	0.0 %
Date:	2017-11-13	Branches:	0	36	0.0 %


/*	$OpenBSD: look.c,v 1.7 2016/09/13 15:29:25 millert Exp $	*/

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * David Hitz of Auspex Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>

u_char	*binary_search(u_char *, u_char *, u_char *);
u_char	*linear_search(u_char *, u_char *, u_char *);
int	 compare(u_char *, u_char *, u_char *);
int	 look(u_char *, u_char *, u_char *);

int
look(u_char *string, u_char *front, u_char *back)
{
	u_char *s;

	/* Convert string to lower case before searching. */
	for (s = string; *s; s++) {
		if (isupper(*s))
			*s = tolower(*s);
	}

	front = binary_search(string, front, back);
	front = linear_search(string, front, back);

	return (front != NULL);
}

/*
 * Binary search for "string" in memory between "front" and "back".
 *
 * This routine is expected to return a pointer to the start of a line at
 * *or before* the first word matching "string".  Relaxing the constraint
 * this way simplifies the algorithm.
 *
 * Invariants:
 * 	front points to the beginning of a line at or before the first
 *	matching string.
 *
 * 	back points to the beginning of a line at or after the first
 *	matching line.
 *
 * Base of the Invariants.
 * 	front = NULL;
 *	back = EOF;
 *
 * Advancing the Invariants:
 *
 * 	p = first newline after halfway point from front to back.
 *
 * 	If the string at "p" is not greater than the string to match,
 *	p is the new front.  Otherwise it is the new back.
 *
 * Termination:
 *
 * 	The definition of the routine allows it return at any point,
 *	since front is always at or before the line to print.
 *
 * 	In fact, it returns when the chosen "p" equals "back".  This
 *	implies that there exists a string is least half as long as
 *	(back - front), which in turn implies that a linear search will
 *	be no more expensive than the cost of simply printing a string or two.
 *
 * 	Trying to continue with binary search at this point would be
 *	more trouble than it's worth.
 */
#define	SKIP_PAST_NEWLINE(p, back) \
	while (p < back && *p++ != '\n');

u_char *
binary_search(u_char *string, u_char *front, u_char *back)
{
	u_char *p;

	p = front + (back - front) / 2;
	SKIP_PAST_NEWLINE(p, back);

	/*
	 * If the file changes underneath us, make sure we don't
	 * infinitely loop.
	 */
	while (p < back && back > front) {
		if (compare(string, p, back) > 0)
			front = p;
		else
			back = p;
		p = front + (back - front) / 2;
		SKIP_PAST_NEWLINE(p, back);
	}
	return (front);
}

/*
 * Find the first line that matches string, linearly searching from front
 * to back.
 *
 * Return NULL for no such line.
 *
 * This routine assumes:
 *
 * 	o front points at the first character in a line.
 *	o front is before or at the first line to be printed.
 */
u_char *
linear_search(u_char *string, u_char *front, u_char *back)
{
	int result;

	while (front < back) {
		result = compare(string, front, back);
		if (result == 0)
			return (front);	/* found it */
		if (result < 0)
			return (NULL);	/* not there */

		SKIP_PAST_NEWLINE(front, back);
	}
	return (NULL);
}

int
compare(u_char *s1, u_char *s2, u_char *back)
{
	int ch;

	/* Note that s1 is already upper case. */
	for (;; ++s1, ++s2) {
		if (*s2 == '\n' || s2 == back)
			ch = '\0';
		else
			ch = tolower(*s2);
		if (*s1 != ch)
			return (*s1 - ch);
		if (ch == '\0')
			return (0);
	}
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: look.c,v 1.7 2016/09/13 15:29:25 millert Exp $ */
2
3			/*-
4			* Copyright (c) 1991, 1993
5			* The Regents of the University of California. All rights reserved.
6			*
7			* This code is derived from software contributed to Berkeley by
8			* David Hitz of Auspex Systems, Inc.
9			*
10			* Redistribution and use in source and binary forms, with or without
11			* modification, are permitted provided that the following conditions
12			* are met:
13			* 1. Redistributions of source code must retain the above copyright
14			* notice, this list of conditions and the following disclaimer.
15			* 2. Redistributions in binary form must reproduce the above copyright
16			* notice, this list of conditions and the following disclaimer in the
17			* documentation and/or other materials provided with the distribution.
18			* 3. Neither the name of the University nor the names of its contributors
19			* may be used to endorse or promote products derived from this software
20			* without specific prior written permission.
21			*
22			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32			* SUCH DAMAGE.
33			*/
34
35			#include <sys/types.h>
36			#include <ctype.h>
37			#include <stdio.h>
38			#include <stdlib.h>
39			#include <string.h>
40			#include <err.h>
41
42			u_char binary_search(u_char , u_char , u_char );
43			u_char linear_search(u_char , u_char , u_char );
44			int compare(u_char , u_char , u_char *);
45			int look(u_char , u_char , u_char *);
46
47			int
48			look(u_char string, u_char front, u_char *back)
49			{
50			u_char *s;
51
52			/* Convert string to lower case before searching. */
53			for (s = string; *s; s++) {
54			if (isupper(*s))
55			s = tolower(s);
56			}
57
58			front = binary_search(string, front, back);
59			front = linear_search(string, front, back);
60
61			return (front != NULL);
62			}
63
64			/*
65			* Binary search for "string" in memory between "front" and "back".
66			*
67			* This routine is expected to return a pointer to the start of a line at
68			* or before the first word matching "string". Relaxing the constraint
69			* this way simplifies the algorithm.
70			*
71			* Invariants:
72			* front points to the beginning of a line at or before the first
73			* matching string.
74			*
75			* back points to the beginning of a line at or after the first
76			* matching line.
77			*
78			* Base of the Invariants.
79			* front = NULL;
80			* back = EOF;
81			*
82			* Advancing the Invariants:
83			*
84			* p = first newline after halfway point from front to back.
85			*
86			* If the string at "p" is not greater than the string to match,
87			* p is the new front. Otherwise it is the new back.
88			*
89			* Termination:
90			*
91			* The definition of the routine allows it return at any point,
92			* since front is always at or before the line to print.
93			*
94			* In fact, it returns when the chosen "p" equals "back". This
95			* implies that there exists a string is least half as long as
96			* (back - front), which in turn implies that a linear search will
97			* be no more expensive than the cost of simply printing a string or two.
98			*
99			* Trying to continue with binary search at this point would be
100			* more trouble than it's worth.
101			*/
102			#define SKIP_PAST_NEWLINE(p, back) \
103			while (p < back && *p++ != '\n');
104
105			u_char *
106			binary_search(u_char string, u_char front, u_char *back)
107			{
108			u_char *p;
109
110			p = front + (back - front) / 2;
111			SKIP_PAST_NEWLINE(p, back);
112
113			/*
114			* If the file changes underneath us, make sure we don't
115			* infinitely loop.
116			*/
117			while (p < back && back > front) {
118			if (compare(string, p, back) > 0)
119			front = p;
120			else
121			back = p;
122			p = front + (back - front) / 2;
123			SKIP_PAST_NEWLINE(p, back);
124			}
125			return (front);
126			}
127
128			/*
129			* Find the first line that matches string, linearly searching from front
130			* to back.
131			*
132			* Return NULL for no such line.
133			*
134			* This routine assumes:
135			*
136			* o front points at the first character in a line.
137			* o front is before or at the first line to be printed.
138			*/
139			u_char *
140			linear_search(u_char string, u_char front, u_char *back)
141			{
142			int result;
143
144			while (front < back) {
145			result = compare(string, front, back);
146			if (result == 0)
147			return (front); /* found it */
148			if (result < 0)
149			return (NULL); /* not there */
150
151			SKIP_PAST_NEWLINE(front, back);
152			}
153			return (NULL);
154			}
155
156			int
157			compare(u_char s1, u_char s2, u_char *back)
158			{
159			int ch;
160
161			/* Note that s1 is already upper case. */
162			for (;; ++s1, ++s2) {
163			if (*s2 == '\n' \|\| s2 == back)
164			ch = '\0';
165			else
166			ch = tolower(*s2);
167			if (*s1 != ch)
168			return (*s1 - ch);
169			if (ch == '\0')
170			return (0);
171			}
172			}