aboutsummaryrefslogtreecommitdiff
path: root/utf8.c
blob: 1eedd8b61aeed9867366df0b70ac849cdef985b9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
#include "git-compat-util.h"
#include "utf8.h"

/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */

struct interval {
  int first;
  int last;
};

/* auxiliary function for binary search in interval table */
static int bisearch(wchar_t ucs, const struct interval *table, int max) {
	int min = 0;
	int mid;

	if (ucs < table[0].first || ucs > table[max].last)
		return 0;
	while (max >= min) {
		mid = (min + max) / 2;
		if (ucs > table[mid].last)
			min = mid + 1;
		else if (ucs < table[mid].first)
			max = mid - 1;
		else
			return 1;
	}

	return 0;
}

/* The following two functions define the column width of an ISO 10646
 * character as follows:
 *
 *    - The null character (U+0000) has a column width of 0.
 *
 *    - Other C0/C1 control characters and DEL will lead to a return
 *      value of -1.
 *
 *    - Non-spacing and enclosing combining characters (general
 *      category code Mn or Me in the Unicode database) have a
 *      column width of 0.
 *
 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
 *
 *    - Other format characters (general category code Cf in the Unicode
 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
 *
 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
 *      have a column width of 0.
 *
 *    - Spacing characters in the East Asian Wide (W) or East Asian
 *      Full-width (F) category as defined in Unicode Technical
 *      Report #11 have a column width of 2.
 *
 *    - All remaining characters (including all printable
 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
 *      etc.) have a column width of 1.
 *
 * This implementation assumes that wchar_t characters are encoded
 * in ISO 10646.
 */

static int wcwidth(wchar_t ch)
{
	/*
	 * Sorted list of non-overlapping intervals of non-spacing characters,
	 * generated by
	 *   "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
	 */
	static const struct interval combining[] = {
		{ 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
		{ 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
		{ 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
		{ 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
		{ 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
		{ 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
		{ 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
		{ 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
		{ 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
		{ 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
		{ 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
		{ 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
		{ 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
		{ 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
		{ 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
		{ 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
		{ 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
		{ 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
		{ 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
		{ 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
		{ 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
		{ 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
		{ 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
		{ 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
		{ 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
		{ 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
		{ 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
		{ 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
		{ 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
		{ 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
		{ 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
		{ 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
		{ 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
		{ 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
		{ 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
		{ 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
		{ 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
		{ 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
		{ 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
		{ 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
		{ 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
		{ 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
	};

	/* test for 8-bit control characters */
	if (ch == 0)
		return 0;
	if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
		return -1;

	/* binary search in table of non-spacing characters */
	if (bisearch(ch, combining, sizeof(combining)
				/ sizeof(struct interval) - 1))
		return 0;

	/*
	 * If we arrive here, ch is neither a combining nor a C0/C1
	 * control character.
	 */

	return 1 +
		(ch >= 0x1100 &&
                    /* Hangul Jamo init. consonants */
		 (ch <= 0x115f ||
		  ch == 0x2329 || ch == 0x232a ||
                  /* CJK ... Yi */
		  (ch >= 0x2e80 && ch <= 0xa4cf &&
		   ch != 0x303f) ||
		  /* Hangul Syllables */
		  (ch >= 0xac00 && ch <= 0xd7a3) ||
		  /* CJK Compatibility Ideographs */
		  (ch >= 0xf900 && ch <= 0xfaff) ||
		  /* CJK Compatibility Forms */
		  (ch >= 0xfe30 && ch <= 0xfe6f) ||
		  /* Fullwidth Forms */
		  (ch >= 0xff00 && ch <= 0xff60) ||
		  (ch >= 0xffe0 && ch <= 0xffe6) ||
		  (ch >= 0x20000 && ch <= 0x2fffd) ||
		  (ch >= 0x30000 && ch <= 0x3fffd)));
}

/*
 * This function returns the number of columns occupied by the character
 * pointed to by the variable start. The pointer is updated to point at
 * the next character. If it was not valid UTF-8, the pointer is set to NULL.
 */
int utf8_width(const char **start)
{
	unsigned char *s = (unsigned char *)*start;
	wchar_t ch;

	if (*s < 0x80) {
		/* 0xxxxxxx */
		ch = *s;
		*start += 1;
	} else if ((s[0] & 0xe0) == 0xc0) {
		/* 110XXXXx 10xxxxxx */
		if ((s[1] & 0xc0) != 0x80 ||
				/* overlong? */
				(s[0] & 0xfe) == 0xc0)
			goto invalid;
		ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
		*start += 2;
	} else if ((s[0] & 0xf0) == 0xe0) {
		/* 1110XXXX 10Xxxxxx 10xxxxxx */
		if ((s[1] & 0xc0) != 0x80 ||
				(s[2] & 0xc0) != 0x80 ||
				/* overlong? */
				(s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
				/* surrogate? */
				(s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
				/* U+FFFE or U+FFFF? */
				(s[0] == 0xef && s[1] == 0xbf &&
				 (s[2] & 0xfe) == 0xbe))
			goto invalid;
		ch = ((s[0] & 0x0f) << 12) |
			((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
		*start += 3;
	} else if ((s[0] & 0xf8) == 0xf0) {
		/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
		if ((s[1] & 0xc0) != 0x80 ||
				(s[2] & 0xc0) != 0x80 ||
				(s[3] & 0xc0) != 0x80 ||
				/* overlong? */
				(s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
				/* > U+10FFFF? */
				(s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
			goto invalid;
		ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
			((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
		*start += 4;
	} else {
invalid:
		*start = NULL;
		return 0;
	}

	return wcwidth(ch);
}

int is_utf8(const char *text)
{
	while (*text) {
		if (*text == '\n' || *text == '\t' || *text == '\r') {
			text++;
			continue;
		}
		utf8_width(&text);
		if (!text)
			return 0;
	}
	return 1;
}

static void print_spaces(int count)
{
	static const char s[] = "                    ";
	while (count >= sizeof(s)) {
		fwrite(s, sizeof(s) - 1, 1, stdout);
		count -= sizeof(s) - 1;
	}
	fwrite(s, count, 1, stdout);
}

/*
 * Wrap the text, if necessary. The variable indent is the indent for the
 * first line, indent2 is the indent for all other lines.
 */
void print_wrapped_text(const char *text, int indent, int indent2, int width)
{
	int w = indent, assume_utf8 = is_utf8(text);
	const char *bol = text, *space = NULL;

	for (;;) {
		char c = *text;
		if (!c || isspace(c)) {
			if (w < width || !space) {
				const char *start = bol;
				if (space)
					start = space;
				else
					print_spaces(indent);
				fwrite(start, text - start, 1, stdout);
				if (!c) {
					putchar('\n');
					return;
				} else if (c == '\t')
					w |= 0x07;
				space = text;
				w++;
				text++;
			}
			else {
				putchar('\n');
				text = bol = space + 1;
				space = NULL;
				w = indent = indent2;
			}
			continue;
		}
		if (assume_utf8)
			w += utf8_width(&text);
		else {
			w++;
			text++;
		}
	}
}

/*
 * Given a buffer and its encoding, return it re-encoded
 * with iconv.  If the conversion fails, returns NULL.
 */
#ifndef NO_ICONV
char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
{
	iconv_t conv;
	size_t insz, outsz, outalloc;
	char *out, *outpos, *cp;

	if (!in_encoding)
		return NULL;
	conv = iconv_open(out_encoding, in_encoding);
	if (conv == (iconv_t) -1)
		return NULL;
	insz = strlen(in);
	outsz = insz;
	outalloc = outsz + 1; /* for terminating NUL */
	out = xmalloc(outalloc);
	outpos = out;
	cp = (char *)in;

	while (1) {
		size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);

		if (cnt == -1) {
			size_t sofar;
			if (errno != E2BIG) {
				free(out);
				iconv_close(conv);
				return NULL;
			}
			/* insz has remaining number of bytes.
			 * since we started outsz the same as insz,
			 * it is likely that insz is not enough for
			 * converting the rest.
			 */
			sofar = outpos - out;
			outalloc = sofar + insz * 2 + 32;
			out = xrealloc(out, outalloc);
			outpos = out + sofar;
			outsz = outalloc - sofar - 1;
		}
		else {
			*outpos = '\0';
			break;
		}
	}
	iconv_close(conv);
	return out;
}
#endif