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 = strchrnul(string, ',');
37 len = ep - string;
38
39 if (*string == '-') {
40 negated = 1;
41 string++;
42 len--;
43 }
44 if (!len)
45 break;
46 for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
47 if (strncmp(whitespace_rule_names[i].rule_name,
48 string, len))
49 continue;
50 if (negated)
51 rule &= ~whitespace_rule_names[i].rule_bits;
52 else
53 rule |= whitespace_rule_names[i].rule_bits;
54 break;
55 }
56 if (strncmp(string, "tabwidth=", 9) == 0) {
57 unsigned tabwidth = atoi(string + 9);
58 if (0 < tabwidth && tabwidth < 0100) {
59 rule &= ~WS_TAB_WIDTH_MASK;
60 rule |= tabwidth;
61 }
62 else
63 warning("tabwidth %.*s out of range",
64 (int)(len - 9), string + 9);
65 }
66 string = ep;
67 }
68
69 if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
70 die("cannot enforce both tab-in-indent and indent-with-non-tab");
71 return rule;
72}
73
74unsigned whitespace_rule(const char *pathname)
75{
76 static struct attr_check *attr_whitespace_rule;
77 const char *value;
78
79 if (!attr_whitespace_rule)
80 attr_whitespace_rule = attr_check_initl("whitespace", NULL);
81
82 git_check_attr(&the_index, pathname, attr_whitespace_rule);
83 value = attr_whitespace_rule->items[0].value;
84 if (ATTR_TRUE(value)) {
85 /* true (whitespace) */
86 unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
87 int i;
88 for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
89 if (!whitespace_rule_names[i].loosens_error &&
90 !whitespace_rule_names[i].exclude_default)
91 all_rule |= whitespace_rule_names[i].rule_bits;
92 return all_rule;
93 } else if (ATTR_FALSE(value)) {
94 /* false (-whitespace) */
95 return ws_tab_width(whitespace_rule_cfg);
96 } else if (ATTR_UNSET(value)) {
97 /* reset to default (!whitespace) */
98 return whitespace_rule_cfg;
99 } else {
100 /* string */
101 return parse_whitespace_rule(value);
102 }
103}
104
105/* The returned string should be freed by the caller. */
106char *whitespace_error_string(unsigned ws)
107{
108 struct strbuf err = STRBUF_INIT;
109 if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
110 strbuf_addstr(&err, "trailing whitespace");
111 else {
112 if (ws & WS_BLANK_AT_EOL)
113 strbuf_addstr(&err, "trailing whitespace");
114 if (ws & WS_BLANK_AT_EOF) {
115 if (err.len)
116 strbuf_addstr(&err, ", ");
117 strbuf_addstr(&err, "new blank line at EOF");
118 }
119 }
120 if (ws & WS_SPACE_BEFORE_TAB) {
121 if (err.len)
122 strbuf_addstr(&err, ", ");
123 strbuf_addstr(&err, "space before tab in indent");
124 }
125 if (ws & WS_INDENT_WITH_NON_TAB) {
126 if (err.len)
127 strbuf_addstr(&err, ", ");
128 strbuf_addstr(&err, "indent with spaces");
129 }
130 if (ws & WS_TAB_IN_INDENT) {
131 if (err.len)
132 strbuf_addstr(&err, ", ");
133 strbuf_addstr(&err, "tab in indent");
134 }
135 return strbuf_detach(&err, NULL);
136}
137
138/* If stream is non-NULL, emits the line after checking. */
139static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
140 FILE *stream, const char *set,
141 const char *reset, const char *ws)
142{
143 unsigned result = 0;
144 int written = 0;
145 int trailing_whitespace = -1;
146 int trailing_newline = 0;
147 int trailing_carriage_return = 0;
148 int i;
149
150 /* Logic is simpler if we temporarily ignore the trailing newline. */
151 if (len > 0 && line[len - 1] == '\n') {
152 trailing_newline = 1;
153 len--;
154 }
155 if ((ws_rule & WS_CR_AT_EOL) &&
156 len > 0 && line[len - 1] == '\r') {
157 trailing_carriage_return = 1;
158 len--;
159 }
160
161 /* Check for trailing whitespace. */
162 if (ws_rule & WS_BLANK_AT_EOL) {
163 for (i = len - 1; i >= 0; i--) {
164 if (isspace(line[i])) {
165 trailing_whitespace = i;
166 result |= WS_BLANK_AT_EOL;
167 }
168 else
169 break;
170 }
171 }
172
173 if (trailing_whitespace == -1)
174 trailing_whitespace = len;
175
176 /* Check indentation */
177 for (i = 0; i < trailing_whitespace; i++) {
178 if (line[i] == ' ')
179 continue;
180 if (line[i] != '\t')
181 break;
182 if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
183 result |= WS_SPACE_BEFORE_TAB;
184 if (stream) {
185 fputs(ws, stream);
186 fwrite(line + written, i - written, 1, stream);
187 fputs(reset, stream);
188 fwrite(line + i, 1, 1, stream);
189 }
190 } else if (ws_rule & WS_TAB_IN_INDENT) {
191 result |= WS_TAB_IN_INDENT;
192 if (stream) {
193 fwrite(line + written, i - written, 1, stream);
194 fputs(ws, stream);
195 fwrite(line + i, 1, 1, stream);
196 fputs(reset, stream);
197 }
198 } else if (stream) {
199 fwrite(line + written, i - written + 1, 1, stream);
200 }
201 written = i + 1;
202 }
203
204 /* Check for indent using non-tab. */
205 if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
206 result |= WS_INDENT_WITH_NON_TAB;
207 if (stream) {
208 fputs(ws, stream);
209 fwrite(line + written, i - written, 1, stream);
210 fputs(reset, stream);
211 }
212 written = i;
213 }
214
215 if (stream) {
216 /*
217 * Now the rest of the line starts at "written".
218 * The non-highlighted part ends at "trailing_whitespace".
219 */
220
221 /* Emit non-highlighted (middle) segment. */
222 if (trailing_whitespace - written > 0) {
223 fputs(set, stream);
224 fwrite(line + written,
225 trailing_whitespace - written, 1, stream);
226 fputs(reset, stream);
227 }
228
229 /* Highlight errors in trailing whitespace. */
230 if (trailing_whitespace != len) {
231 fputs(ws, stream);
232 fwrite(line + trailing_whitespace,
233 len - trailing_whitespace, 1, stream);
234 fputs(reset, stream);
235 }
236 if (trailing_carriage_return)
237 fputc('\r', stream);
238 if (trailing_newline)
239 fputc('\n', stream);
240 }
241 return result;
242}
243
244void ws_check_emit(const char *line, int len, unsigned ws_rule,
245 FILE *stream, const char *set,
246 const char *reset, const char *ws)
247{
248 (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
249}
250
251unsigned ws_check(const char *line, int len, unsigned ws_rule)
252{
253 return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
254}
255
256int ws_blank_line(const char *line, int len, unsigned ws_rule)
257{
258 /*
259 * We _might_ want to treat CR differently from other
260 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
261 * for now we just use this stupid definition.
262 */
263 while (len-- > 0) {
264 if (!isspace(*line))
265 return 0;
266 line++;
267 }
268 return 1;
269}
270
271/* Copy the line onto the end of the strbuf while fixing whitespaces */
272void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
273{
274 /*
275 * len is number of bytes to be copied from src, starting
276 * at src. Typically src[len-1] is '\n', unless this is
277 * the incomplete last line.
278 */
279 int i;
280 int add_nl_to_tail = 0;
281 int add_cr_to_tail = 0;
282 int fixed = 0;
283 int last_tab_in_indent = -1;
284 int last_space_in_indent = -1;
285 int need_fix_leading_space = 0;
286
287 /*
288 * Strip trailing whitespace
289 */
290 if (ws_rule & WS_BLANK_AT_EOL) {
291 if (0 < len && src[len - 1] == '\n') {
292 add_nl_to_tail = 1;
293 len--;
294 if (0 < len && src[len - 1] == '\r') {
295 add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
296 len--;
297 }
298 }
299 if (0 < len && isspace(src[len - 1])) {
300 while (0 < len && isspace(src[len-1]))
301 len--;
302 fixed = 1;
303 }
304 }
305
306 /*
307 * Check leading whitespaces (indent)
308 */
309 for (i = 0; i < len; i++) {
310 char ch = src[i];
311 if (ch == '\t') {
312 last_tab_in_indent = i;
313 if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
314 0 <= last_space_in_indent)
315 need_fix_leading_space = 1;
316 } else if (ch == ' ') {
317 last_space_in_indent = i;
318 if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
319 ws_tab_width(ws_rule) <= i - last_tab_in_indent)
320 need_fix_leading_space = 1;
321 } else
322 break;
323 }
324
325 if (need_fix_leading_space) {
326 /* Process indent ourselves */
327 int consecutive_spaces = 0;
328 int last = last_tab_in_indent + 1;
329
330 if (ws_rule & WS_INDENT_WITH_NON_TAB) {
331 /* have "last" point at one past the indent */
332 if (last_tab_in_indent < last_space_in_indent)
333 last = last_space_in_indent + 1;
334 else
335 last = last_tab_in_indent + 1;
336 }
337
338 /*
339 * between src[0..last-1], strip the funny spaces,
340 * updating them to tab as needed.
341 */
342 for (i = 0; i < last; i++) {
343 char ch = src[i];
344 if (ch != ' ') {
345 consecutive_spaces = 0;
346 strbuf_addch(dst, ch);
347 } else {
348 consecutive_spaces++;
349 if (consecutive_spaces == ws_tab_width(ws_rule)) {
350 strbuf_addch(dst, '\t');
351 consecutive_spaces = 0;
352 }
353 }
354 }
355 while (0 < consecutive_spaces--)
356 strbuf_addch(dst, ' ');
357 len -= last;
358 src += last;
359 fixed = 1;
360 } else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
361 /* Expand tabs into spaces */
362 int start = dst->len;
363 int last = last_tab_in_indent + 1;
364 for (i = 0; i < last; i++) {
365 if (src[i] == '\t')
366 do {
367 strbuf_addch(dst, ' ');
368 } while ((dst->len - start) % ws_tab_width(ws_rule));
369 else
370 strbuf_addch(dst, src[i]);
371 }
372 len -= last;
373 src += last;
374 fixed = 1;
375 }
376
377 strbuf_add(dst, src, len);
378 if (add_cr_to_tail)
379 strbuf_addch(dst, '\r');
380 if (add_nl_to_tail)
381 strbuf_addch(dst, '\n');
382 if (fixed && error_count)
383 (*error_count)++;
384}