summaryrefslogtreecommitdiff
path: root/ws.c
blob: 5b67b426e7b41d92f9b11bd82fd7e9bd09c89d79 (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
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
/*
 * Whitespace rules
 *
 * Copyright (c) 2007 Junio C Hamano
 */

#include "cache.h"
#include "attr.h"

static struct whitespace_rule {
	const char *rule_name;
	unsigned rule_bits;
	unsigned loosens_error:1,
		exclude_default:1;
} whitespace_rule_names[] = {
	{ "trailing-space", WS_TRAILING_SPACE, 0 },
	{ "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
	{ "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
	{ "cr-at-eol", WS_CR_AT_EOL, 1 },
	{ "blank-at-eol", WS_BLANK_AT_EOL, 0 },
	{ "blank-at-eof", WS_BLANK_AT_EOF, 0 },
	{ "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
};

unsigned parse_whitespace_rule(const char *string)
{
	unsigned rule = WS_DEFAULT_RULE;

	while (string) {
		int i;
		size_t len;
		const char *ep;
		int negated = 0;

		string = string + strspn(string, ", \t\n\r");
		ep = strchrnul(string, ',');
		len = ep - string;

		if (*string == '-') {
			negated = 1;
			string++;
			len--;
		}
		if (!len)
			break;
		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
			if (strncmp(whitespace_rule_names[i].rule_name,
				    string, len))
				continue;
			if (negated)
				rule &= ~whitespace_rule_names[i].rule_bits;
			else
				rule |= whitespace_rule_names[i].rule_bits;
			break;
		}
		if (strncmp(string, "tabwidth=", 9) == 0) {
			unsigned tabwidth = atoi(string + 9);
			if (0 < tabwidth && tabwidth < 0100) {
				rule &= ~WS_TAB_WIDTH_MASK;
				rule |= tabwidth;
			}
			else
				warning("tabwidth %.*s out of range",
					(int)(len - 9), string + 9);
		}
		string = ep;
	}

	if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
		die("cannot enforce both tab-in-indent and indent-with-non-tab");
	return rule;
}

unsigned whitespace_rule(const char *pathname)
{
	static struct attr_check *attr_whitespace_rule;

	if (!attr_whitespace_rule)
		attr_whitespace_rule = attr_check_initl("whitespace", NULL);

	if (!git_check_attr(&the_index, pathname, attr_whitespace_rule)) {
		const char *value;

		value = attr_whitespace_rule->items[0].value;
		if (ATTR_TRUE(value)) {
			/* true (whitespace) */
			unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
			int i;
			for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
				if (!whitespace_rule_names[i].loosens_error &&
				    !whitespace_rule_names[i].exclude_default)
					all_rule |= whitespace_rule_names[i].rule_bits;
			return all_rule;
		} else if (ATTR_FALSE(value)) {
			/* false (-whitespace) */
			return ws_tab_width(whitespace_rule_cfg);
		} else if (ATTR_UNSET(value)) {
			/* reset to default (!whitespace) */
			return whitespace_rule_cfg;
		} else {
			/* string */
			return parse_whitespace_rule(value);
		}
	} else {
		return whitespace_rule_cfg;
	}
}

/* The returned string should be freed by the caller. */
char *whitespace_error_string(unsigned ws)
{
	struct strbuf err = STRBUF_INIT;
	if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
		strbuf_addstr(&err, "trailing whitespace");
	else {
		if (ws & WS_BLANK_AT_EOL)
			strbuf_addstr(&err, "trailing whitespace");
		if (ws & WS_BLANK_AT_EOF) {
			if (err.len)
				strbuf_addstr(&err, ", ");
			strbuf_addstr(&err, "new blank line at EOF");
		}
	}
	if (ws & WS_SPACE_BEFORE_TAB) {
		if (err.len)
			strbuf_addstr(&err, ", ");
		strbuf_addstr(&err, "space before tab in indent");
	}
	if (ws & WS_INDENT_WITH_NON_TAB) {
		if (err.len)
			strbuf_addstr(&err, ", ");
		strbuf_addstr(&err, "indent with spaces");
	}
	if (ws & WS_TAB_IN_INDENT) {
		if (err.len)
			strbuf_addstr(&err, ", ");
		strbuf_addstr(&err, "tab in indent");
	}
	return strbuf_detach(&err, NULL);
}

/* If stream is non-NULL, emits the line after checking. */
static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
				FILE *stream, const char *set,
				const char *reset, const char *ws)
{
	unsigned result = 0;
	int written = 0;
	int trailing_whitespace = -1;
	int trailing_newline = 0;
	int trailing_carriage_return = 0;
	int i;

	/* Logic is simpler if we temporarily ignore the trailing newline. */
	if (len > 0 && line[len - 1] == '\n') {
		trailing_newline = 1;
		len--;
	}
	if ((ws_rule & WS_CR_AT_EOL) &&
	    len > 0 && line[len - 1] == '\r') {
		trailing_carriage_return = 1;
		len--;
	}

	/* Check for trailing whitespace. */
	if (ws_rule & WS_BLANK_AT_EOL) {
		for (i = len - 1; i >= 0; i--) {
			if (isspace(line[i])) {
				trailing_whitespace = i;
				result |= WS_BLANK_AT_EOL;
			}
			else
				break;
		}
	}

	if (trailing_whitespace == -1)
		trailing_whitespace = len;

	/* Check indentation */
	for (i = 0; i < trailing_whitespace; i++) {
		if (line[i] == ' ')
			continue;
		if (line[i] != '\t')
			break;
		if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
			result |= WS_SPACE_BEFORE_TAB;
			if (stream) {
				fputs(ws, stream);
				fwrite(line + written, i - written, 1, stream);
				fputs(reset, stream);
				fwrite(line + i, 1, 1, stream);
			}
		} else if (ws_rule & WS_TAB_IN_INDENT) {
			result |= WS_TAB_IN_INDENT;
			if (stream) {
				fwrite(line + written, i - written, 1, stream);
				fputs(ws, stream);
				fwrite(line + i, 1, 1, stream);
				fputs(reset, stream);
			}
		} else if (stream) {
			fwrite(line + written, i - written + 1, 1, stream);
		}
		written = i + 1;
	}

	/* Check for indent using non-tab. */
	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
		result |= WS_INDENT_WITH_NON_TAB;
		if (stream) {
			fputs(ws, stream);
			fwrite(line + written, i - written, 1, stream);
			fputs(reset, stream);
		}
		written = i;
	}

	if (stream) {
		/*
		 * Now the rest of the line starts at "written".
		 * The non-highlighted part ends at "trailing_whitespace".
		 */

		/* Emit non-highlighted (middle) segment. */
		if (trailing_whitespace - written > 0) {
			fputs(set, stream);
			fwrite(line + written,
			    trailing_whitespace - written, 1, stream);
			fputs(reset, stream);
		}

		/* Highlight errors in trailing whitespace. */
		if (trailing_whitespace != len) {
			fputs(ws, stream);
			fwrite(line + trailing_whitespace,
			    len - trailing_whitespace, 1, stream);
			fputs(reset, stream);
		}
		if (trailing_carriage_return)
			fputc('\r', stream);
		if (trailing_newline)
			fputc('\n', stream);
	}
	return result;
}

void ws_check_emit(const char *line, int len, unsigned ws_rule,
		   FILE *stream, const char *set,
		   const char *reset, const char *ws)
{
	(void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
}

unsigned ws_check(const char *line, int len, unsigned ws_rule)
{
	return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
}

int ws_blank_line(const char *line, int len, unsigned ws_rule)
{
	/*
	 * We _might_ want to treat CR differently from other
	 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
	 * for now we just use this stupid definition.
	 */
	while (len-- > 0) {
		if (!isspace(*line))
			return 0;
		line++;
	}
	return 1;
}

/* Copy the line onto the end of the strbuf while fixing whitespaces */
void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
{
	/*
	 * len is number of bytes to be copied from src, starting
	 * at src.  Typically src[len-1] is '\n', unless this is
	 * the incomplete last line.
	 */
	int i;
	int add_nl_to_tail = 0;
	int add_cr_to_tail = 0;
	int fixed = 0;
	int last_tab_in_indent = -1;
	int last_space_in_indent = -1;
	int need_fix_leading_space = 0;

	/*
	 * Strip trailing whitespace
	 */
	if (ws_rule & WS_BLANK_AT_EOL) {
		if (0 < len && src[len - 1] == '\n') {
			add_nl_to_tail = 1;
			len--;
			if (0 < len && src[len - 1] == '\r') {
				add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
				len--;
			}
		}
		if (0 < len && isspace(src[len - 1])) {
			while (0 < len && isspace(src[len-1]))
				len--;
			fixed = 1;
		}
	}

	/*
	 * Check leading whitespaces (indent)
	 */
	for (i = 0; i < len; i++) {
		char ch = src[i];
		if (ch == '\t') {
			last_tab_in_indent = i;
			if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
			    0 <= last_space_in_indent)
			    need_fix_leading_space = 1;
		} else if (ch == ' ') {
			last_space_in_indent = i;
			if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
			    ws_tab_width(ws_rule) <= i - last_tab_in_indent)
				need_fix_leading_space = 1;
		} else
			break;
	}

	if (need_fix_leading_space) {
		/* Process indent ourselves */
		int consecutive_spaces = 0;
		int last = last_tab_in_indent + 1;

		if (ws_rule & WS_INDENT_WITH_NON_TAB) {
			/* have "last" point at one past the indent */
			if (last_tab_in_indent < last_space_in_indent)
				last = last_space_in_indent + 1;
			else
				last = last_tab_in_indent + 1;
		}

		/*
		 * between src[0..last-1], strip the funny spaces,
		 * updating them to tab as needed.
		 */
		for (i = 0; i < last; i++) {
			char ch = src[i];
			if (ch != ' ') {
				consecutive_spaces = 0;
				strbuf_addch(dst, ch);
			} else {
				consecutive_spaces++;
				if (consecutive_spaces == ws_tab_width(ws_rule)) {
					strbuf_addch(dst, '\t');
					consecutive_spaces = 0;
				}
			}
		}
		while (0 < consecutive_spaces--)
			strbuf_addch(dst, ' ');
		len -= last;
		src += last;
		fixed = 1;
	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
		/* Expand tabs into spaces */
		int start = dst->len;
		int last = last_tab_in_indent + 1;
		for (i = 0; i < last; i++) {
			if (src[i] == '\t')
				do {
					strbuf_addch(dst, ' ');
				} while ((dst->len - start) % ws_tab_width(ws_rule));
			else
				strbuf_addch(dst, src[i]);
		}
		len -= last;
		src += last;
		fixed = 1;
	}

	strbuf_add(dst, src, len);
	if (add_cr_to_tail)
		strbuf_addch(dst, '\r');
	if (add_nl_to_tail)
		strbuf_addch(dst, '\n');
	if (fixed && error_count)
		(*error_count)++;
}