1/*
2 * Whitespace rules
3 *
4 * Copyright (c) 2007 Junio C Hamano
5 */
6
7#include "cache.h"
8#include "attr.h"
9
10static struct whitespace_rule {
11 const char *rule_name;
12 unsigned rule_bits;
13 unsigned loosens_error:1,
14 exclude_default:1;
15} whitespace_rule_names[] = {
16 { "trailing-space", WS_TRAILING_SPACE, 0 },
17 { "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
18 { "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
19 { "cr-at-eol", WS_CR_AT_EOL, 1 },
20 { "blank-at-eol", WS_BLANK_AT_EOL, 0 },
21 { "blank-at-eof", WS_BLANK_AT_EOF, 0 },
22 { "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
23};
24
25unsigned parse_whitespace_rule(const char *string)
26{
27 unsigned rule = WS_DEFAULT_RULE;
28
29 while (string) {
30 int i;
31 size_t len;
32 const char *ep;
33 int negated = 0;
34
35 string = string + strspn(string, ", \t\n\r");
36 ep = strchr(string, ',');
37 if (!ep)
38 len = strlen(string);
39 else
40 len = ep - string;
41
42 if (*string == '-') {
43 negated = 1;
44 string++;
45 len--;
46 }
47 if (!len)
48 break;
49 for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
50 if (strncmp(whitespace_rule_names[i].rule_name,
51 string, len))
52 continue;
53 if (negated)
54 rule &= ~whitespace_rule_names[i].rule_bits;
55 else
56 rule |= whitespace_rule_names[i].rule_bits;
57 break;
58 }
59 string = ep;
60 }
61
62 if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
63 die("cannot enforce both tab-in-indent and indent-with-non-tab");
64 return rule;
65}
66
67static void setup_whitespace_attr_check(struct git_attr_check *check)
68{
69 static struct git_attr *attr_whitespace;
70
71 if (!attr_whitespace)
72 attr_whitespace = git_attr("whitespace");
73 check[0].attr = attr_whitespace;
74}
75
76unsigned whitespace_rule(const char *pathname)
77{
78 struct git_attr_check attr_whitespace_rule;
79
80 setup_whitespace_attr_check(&attr_whitespace_rule);
81 if (!git_checkattr(pathname, 1, &attr_whitespace_rule)) {
82 const char *value;
83
84 value = attr_whitespace_rule.value;
85 if (ATTR_TRUE(value)) {
86 /* true (whitespace) */
87 unsigned all_rule = 0;
88 int i;
89 for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
90 if (!whitespace_rule_names[i].loosens_error &&
91 !whitespace_rule_names[i].exclude_default)
92 all_rule |= whitespace_rule_names[i].rule_bits;
93 return all_rule;
94 } else if (ATTR_FALSE(value)) {
95 /* false (-whitespace) */
96 return 0;
97 } else if (ATTR_UNSET(value)) {
98 /* reset to default (!whitespace) */
99 return whitespace_rule_cfg;
100 } else {
101 /* string */
102 return parse_whitespace_rule(value);
103 }
104 } else {
105 return whitespace_rule_cfg;
106 }
107}
108
109/* The returned string should be freed by the caller. */
110char *whitespace_error_string(unsigned ws)
111{
112 struct strbuf err = STRBUF_INIT;
113 if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
114 strbuf_addstr(&err, "trailing whitespace");
115 else {
116 if (ws & WS_BLANK_AT_EOL)
117 strbuf_addstr(&err, "trailing whitespace");
118 if (ws & WS_BLANK_AT_EOF) {
119 if (err.len)
120 strbuf_addstr(&err, ", ");
121 strbuf_addstr(&err, "new blank line at EOF");
122 }
123 }
124 if (ws & WS_SPACE_BEFORE_TAB) {
125 if (err.len)
126 strbuf_addstr(&err, ", ");
127 strbuf_addstr(&err, "space before tab in indent");
128 }
129 if (ws & WS_INDENT_WITH_NON_TAB) {
130 if (err.len)
131 strbuf_addstr(&err, ", ");
132 strbuf_addstr(&err, "indent with spaces");
133 }
134 if (ws & WS_TAB_IN_INDENT) {
135 if (err.len)
136 strbuf_addstr(&err, ", ");
137 strbuf_addstr(&err, "tab in indent");
138 }
139 return strbuf_detach(&err, NULL);
140}
141
142/* If stream is non-NULL, emits the line after checking. */
143static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
144 FILE *stream, const char *set,
145 const char *reset, const char *ws)
146{
147 unsigned result = 0;
148 int written = 0;
149 int trailing_whitespace = -1;
150 int trailing_newline = 0;
151 int trailing_carriage_return = 0;
152 int i;
153
154 /* Logic is simpler if we temporarily ignore the trailing newline. */
155 if (len > 0 && line[len - 1] == '\n') {
156 trailing_newline = 1;
157 len--;
158 }
159 if ((ws_rule & WS_CR_AT_EOL) &&
160 len > 0 && line[len - 1] == '\r') {
161 trailing_carriage_return = 1;
162 len--;
163 }
164
165 /* Check for trailing whitespace. */
166 if (ws_rule & WS_BLANK_AT_EOL) {
167 for (i = len - 1; i >= 0; i--) {
168 if (isspace(line[i])) {
169 trailing_whitespace = i;
170 result |= WS_BLANK_AT_EOL;
171 }
172 else
173 break;
174 }
175 }
176
177 if (trailing_whitespace == -1)
178 trailing_whitespace = len;
179
180 /* Check indentation */
181 for (i = 0; i < trailing_whitespace; i++) {
182 if (line[i] == ' ')
183 continue;
184 if (line[i] != '\t')
185 break;
186 if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
187 result |= WS_SPACE_BEFORE_TAB;
188 if (stream) {
189 fputs(ws, stream);
190 fwrite(line + written, i - written, 1, stream);
191 fputs(reset, stream);
192 fwrite(line + i, 1, 1, stream);
193 }
194 } else if (ws_rule & WS_TAB_IN_INDENT) {
195 result |= WS_TAB_IN_INDENT;
196 if (stream) {
197 fwrite(line + written, i - written, 1, stream);
198 fputs(ws, stream);
199 fwrite(line + i, 1, 1, stream);
200 fputs(reset, stream);
201 }
202 } else if (stream) {
203 fwrite(line + written, i - written + 1, 1, stream);
204 }
205 written = i + 1;
206 }
207
208 /* Check for indent using non-tab. */
209 if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= 8) {
210 result |= WS_INDENT_WITH_NON_TAB;
211 if (stream) {
212 fputs(ws, stream);
213 fwrite(line + written, i - written, 1, stream);
214 fputs(reset, stream);
215 }
216 written = i;
217 }
218
219 if (stream) {
220 /*
221 * Now the rest of the line starts at "written".
222 * The non-highlighted part ends at "trailing_whitespace".
223 */
224
225 /* Emit non-highlighted (middle) segment. */
226 if (trailing_whitespace - written > 0) {
227 fputs(set, stream);
228 fwrite(line + written,
229 trailing_whitespace - written, 1, stream);
230 fputs(reset, stream);
231 }
232
233 /* Highlight errors in trailing whitespace. */
234 if (trailing_whitespace != len) {
235 fputs(ws, stream);
236 fwrite(line + trailing_whitespace,
237 len - trailing_whitespace, 1, stream);
238 fputs(reset, stream);
239 }
240 if (trailing_carriage_return)
241 fputc('\r', stream);
242 if (trailing_newline)
243 fputc('\n', stream);
244 }
245 return result;
246}
247
248void ws_check_emit(const char *line, int len, unsigned ws_rule,
249 FILE *stream, const char *set,
250 const char *reset, const char *ws)
251{
252 (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
253}
254
255unsigned ws_check(const char *line, int len, unsigned ws_rule)
256{
257 return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
258}
259
260int ws_blank_line(const char *line, int len, unsigned ws_rule)
261{
262 /*
263 * We _might_ want to treat CR differently from other
264 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
265 * for now we just use this stupid definition.
266 */
267 while (len-- > 0) {
268 if (!isspace(*line))
269 return 0;
270 line++;
271 }
272 return 1;
273}
274
275/* Copy the line onto the end of the strbuf while fixing whitespaces */
276void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
277{
278 /*
279 * len is number of bytes to be copied from src, starting
280 * at src. Typically src[len-1] is '\n', unless this is
281 * the incomplete last line.
282 */
283 int i;
284 int add_nl_to_tail = 0;
285 int add_cr_to_tail = 0;
286 int fixed = 0;
287 int last_tab_in_indent = -1;
288 int last_space_in_indent = -1;
289 int need_fix_leading_space = 0;
290
291 /*
292 * Strip trailing whitespace
293 */
294 if (ws_rule & WS_BLANK_AT_EOL) {
295 if (0 < len && src[len - 1] == '\n') {
296 add_nl_to_tail = 1;
297 len--;
298 if (0 < len && src[len - 1] == '\r') {
299 add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
300 len--;
301 }
302 }
303 if (0 < len && isspace(src[len - 1])) {
304 while (0 < len && isspace(src[len-1]))
305 len--;
306 fixed = 1;
307 }
308 }
309
310 /*
311 * Check leading whitespaces (indent)
312 */
313 for (i = 0; i < len; i++) {
314 char ch = src[i];
315 if (ch == '\t') {
316 last_tab_in_indent = i;
317 if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
318 0 <= last_space_in_indent)
319 need_fix_leading_space = 1;
320 } else if (ch == ' ') {
321 last_space_in_indent = i;
322 if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
323 8 <= i - last_tab_in_indent)
324 need_fix_leading_space = 1;
325 } else
326 break;
327 }
328
329 if (need_fix_leading_space) {
330 /* Process indent ourselves */
331 int consecutive_spaces = 0;
332 int last = last_tab_in_indent + 1;
333
334 if (ws_rule & WS_INDENT_WITH_NON_TAB) {
335 /* have "last" point at one past the indent */
336 if (last_tab_in_indent < last_space_in_indent)
337 last = last_space_in_indent + 1;
338 else
339 last = last_tab_in_indent + 1;
340 }
341
342 /*
343 * between src[0..last-1], strip the funny spaces,
344 * updating them to tab as needed.
345 */
346 for (i = 0; i < last; i++) {
347 char ch = src[i];
348 if (ch != ' ') {
349 consecutive_spaces = 0;
350 strbuf_addch(dst, ch);
351 } else {
352 consecutive_spaces++;
353 if (consecutive_spaces == 8) {
354 strbuf_addch(dst, '\t');
355 consecutive_spaces = 0;
356 }
357 }
358 }
359 while (0 < consecutive_spaces--)
360 strbuf_addch(dst, ' ');
361 len -= last;
362 src += last;
363 fixed = 1;
364 } else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
365 /* Expand tabs into spaces */
366 int last = last_tab_in_indent + 1;
367 for (i = 0; i < last; i++) {
368 if (src[i] == '\t')
369 do {
370 strbuf_addch(dst, ' ');
371 } while (dst->len % 8);
372 else
373 strbuf_addch(dst, src[i]);
374 }
375 len -= last;
376 src += last;
377 fixed = 1;
378 }
379
380 strbuf_add(dst, src, len);
381 if (add_cr_to_tail)
382 strbuf_addch(dst, '\r');
383 if (add_nl_to_tail)
384 strbuf_addch(dst, '\n');
385 if (fixed && error_count)
386 (*error_count)++;
387}