xref: /openbsd-src/usr.bin/make/buf.c (revision d13be5d47e4149db2549a9828e244d59dbc43f15)
1 /*	$OpenBSD: buf.c,v 1.23 2010/07/19 19:46:43 espie Exp $	*/
2 /*	$NetBSD: buf.c,v 1.9 1996/12/31 17:53:21 christos Exp $ */
3 
4 /*
5  * Copyright (c) 1999 Marc Espie.
6  *
7  * Extensive code changes for the OpenBSD project.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
22  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 /*
31  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
32  * Copyright (c) 1988, 1989 by Adam de Boor
33  * Copyright (c) 1989 by Berkeley Softworks
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Adam de Boor.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  */
63 
64 /*-
65  * buf.c --
66  *	Functions for automatically expanded buffers.
67  */
68 
69 #include <ctype.h>
70 #include <stddef.h>
71 #include <string.h>
72 #include "config.h"
73 #include "defines.h"
74 #include "buf.h"
75 #include "stats.h"
76 #include "memory.h"
77 
78 #ifdef STATS_BUF
79 #define DO_STAT_BUF(bp, nb)					\
80 	STAT_BUFS_EXPANSION++;			\
81 	if ((bp)->endPtr - (bp)->buffer == 1)			\
82 		STAT_WEIRD_INEFFICIENT++;
83 #else
84 #define DO_STAT_BUF(a, b)
85 #endif
86 
87 /* BufExpand(bp, nb)
88  *	Expand buffer bp to hold upto nb additional
89  *	chars.	Makes sure there's room for an extra '\0' char at
90  *	the end of the buffer to terminate the string.	*/
91 #define BufExpand(bp,nb)				\
92 do {							\
93 	size_t   occupied = (bp)->inPtr - (bp)->buffer;	\
94 	size_t   size = (bp)->endPtr - (bp)->buffer;	\
95 	DO_STAT_BUF(bp, nb);				\
96 							\
97 	do {						\
98 		size *= 2 ;				\
99 	} while (size - occupied < (nb)+1+BUF_MARGIN);	\
100 	(bp)->buffer = (bp)->inPtr = (bp)->endPtr = 	\
101 		erealloc((bp)->buffer, size);		\
102 	(bp)->inPtr += occupied;			\
103 	(bp)->endPtr += size;				\
104 } while (0);
105 
106 #define BUF_DEF_SIZE	256	/* Default buffer size */
107 #define BUF_MARGIN	256	/* Make sure we are comfortable */
108 
109 /* the hard case for Buf_AddChar: buffer must be expanded to accommodate
110  * one more char.  */
111 void
112 BufOverflow(Buffer bp)
113 {
114 	BufExpand(bp, 1);
115 }
116 
117 
118 void
119 Buf_AddChars(Buffer bp, size_t numBytes, const char *bytesPtr)
120 {
121 
122 	if ((size_t)(bp->endPtr - bp->inPtr) < numBytes+1)
123 		BufExpand(bp, numBytes);
124 
125 	memcpy(bp->inPtr, bytesPtr, numBytes);
126 	bp->inPtr += numBytes;
127 }
128 
129 
130 void
131 Buf_Init(Buffer bp, size_t size)
132 {
133 #ifdef STATS_BUF
134 	STAT_TOTAL_BUFS++;
135 	if (size == 0)
136 		STAT_DEFAULT_BUFS++;
137 	if (size == 1)
138 		STAT_WEIRD_BUFS++;
139 #endif
140 	if (size == 0)
141 		size = BUF_DEF_SIZE;
142 	bp->inPtr = bp->endPtr = bp->buffer = emalloc(size);
143 	bp->endPtr += size;
144 }
145 
146 void
147 Buf_KillTrailingSpaces(Buffer bp)
148 {
149 	while (bp->inPtr > bp->buffer + 1 && isspace(bp->inPtr[-1])) {
150 		if (bp->inPtr[-2] == '\\')
151 		    break;
152 		bp->inPtr--;
153 	}
154 }
155