xref: /illumos-gate/usr/src/cmd/mandoc/preconv.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*	$Id: preconv.c,v 1.17 2018/12/13 11:55:47 schwarze Exp $ */
2 /*
3  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4  * Copyright (c) 2014 Ingo Schwarze <schwarze@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 #include "config.h"
19 
20 #include <sys/types.h>
21 
22 #include <assert.h>
23 #include <stdio.h>
24 #include <string.h>
25 
26 #include "mandoc.h"
27 #include "roff.h"
28 #include "mandoc_parse.h"
29 #include "libmandoc.h"
30 
31 int
32 preconv_encode(const struct buf *ib, size_t *ii, struct buf *ob, size_t *oi,
33     int *filenc)
34 {
35 	const unsigned char	*cu;
36 	int			 nby;
37 	unsigned int		 accum;
38 
39 	cu = (const unsigned char *)ib->buf + *ii;
40 	assert(*cu & 0x80);
41 
42 	if ( ! (*filenc & MPARSE_UTF8))
43 		goto latin;
44 
45 	nby = 1;
46 	while (nby < 5 && *cu & (1 << (7 - nby)))
47 		nby++;
48 
49 	switch (nby) {
50 	case 2:
51 		accum = *cu & 0x1f;
52 		if (accum < 0x02)  /* Obfuscated ASCII. */
53 			goto latin;
54 		break;
55 	case 3:
56 		accum = *cu & 0x0f;
57 		break;
58 	case 4:
59 		accum = *cu & 0x07;
60 		if (accum > 0x04) /* Beyond Unicode. */
61 			goto latin;
62 		break;
63 	default:  /* Bad sequence header. */
64 		goto latin;
65 	}
66 
67 	cu++;
68 	switch (nby) {
69 	case 3:
70 		if ((accum == 0x00 && ! (*cu & 0x20)) ||  /* Use 2-byte. */
71 		    (accum == 0x0d && *cu & 0x20))  /* Surrogates. */
72 			goto latin;
73 		break;
74 	case 4:
75 		if ((accum == 0x00 && ! (*cu & 0x30)) ||  /* Use 3-byte. */
76 		    (accum == 0x04 && *cu & 0x30))  /* Beyond Unicode. */
77 			goto latin;
78 		break;
79 	default:
80 		break;
81 	}
82 
83 	while (--nby) {
84 		if ((*cu & 0xc0) != 0x80)  /* Invalid continuation. */
85 			goto latin;
86 		accum <<= 6;
87 		accum += *cu & 0x3f;
88 		cu++;
89 	}
90 
91 	assert(accum > 0x7f);
92 	assert(accum < 0x110000);
93 	assert(accum < 0xd800 || accum > 0xdfff);
94 
95 	*oi += snprintf(ob->buf + *oi, 11, "\\[u%.4X]", accum);
96 	*ii = (const char *)cu - ib->buf;
97 	*filenc &= ~MPARSE_LATIN1;
98 	return 1;
99 
100 latin:
101 	if ( ! (*filenc & MPARSE_LATIN1))
102 		return 0;
103 
104 	*oi += snprintf(ob->buf + *oi, 11,
105 	    "\\[u%.4X]", (unsigned char)ib->buf[(*ii)++]);
106 
107 	*filenc &= ~MPARSE_UTF8;
108 	return 1;
109 }
110 
111 int
112 preconv_cue(const struct buf *b, size_t offset)
113 {
114 	const char	*ln, *eoln, *eoph;
115 	size_t		 sz, phsz;
116 
117 	ln = b->buf + offset;
118 	sz = b->sz - offset;
119 
120 	/* Look for the end-of-line. */
121 
122 	if (NULL == (eoln = memchr(ln, '\n', sz)))
123 		eoln = ln + sz;
124 
125 	/* Check if we have the correct header/trailer. */
126 
127 	if ((sz = (size_t)(eoln - ln)) < 10 ||
128 	    memcmp(ln, ".\\\" -*-", 7) || memcmp(eoln - 3, "-*-", 3))
129 		return MPARSE_UTF8 | MPARSE_LATIN1;
130 
131 	/* Move after the header and adjust for the trailer. */
132 
133 	ln += 7;
134 	sz -= 10;
135 
136 	while (sz > 0) {
137 		while (sz > 0 && ' ' == *ln) {
138 			ln++;
139 			sz--;
140 		}
141 		if (0 == sz)
142 			break;
143 
144 		/* Find the end-of-phrase marker (or eoln). */
145 
146 		if (NULL == (eoph = memchr(ln, ';', sz)))
147 			eoph = eoln - 3;
148 		else
149 			eoph++;
150 
151 		/* Only account for the "coding" phrase. */
152 
153 		if ((phsz = eoph - ln) < 7 ||
154 		    strncasecmp(ln, "coding:", 7)) {
155 			sz -= phsz;
156 			ln += phsz;
157 			continue;
158 		}
159 
160 		sz -= 7;
161 		ln += 7;
162 
163 		while (sz > 0 && ' ' == *ln) {
164 			ln++;
165 			sz--;
166 		}
167 		if (0 == sz)
168 			return 0;
169 
170 		/* Check us against known encodings. */
171 
172 		if (phsz > 4 && !strncasecmp(ln, "utf-8", 5))
173 			return MPARSE_UTF8;
174 		if (phsz > 10 && !strncasecmp(ln, "iso-latin-1", 11))
175 			return MPARSE_LATIN1;
176 		return 0;
177 	}
178 	return MPARSE_UTF8 | MPARSE_LATIN1;
179 }
180