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