t/t4202-log.sh: add newline at end of file
[git] / ws.c
1 /*
2  * Whitespace rules
3  *
4  * Copyright (c) 2007 Junio C Hamano
5  */
6
7 #include "cache.h"
8 #include "attr.h"
9
10 static 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
20 unsigned 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
59 static 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
68 unsigned 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. */
100 char *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. */
120 unsigned check_and_emit_line(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
216 /* Copy the line to the buffer while fixing whitespaces */
217 int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *error_count)
218 {
219         /*
220          * len is number of bytes to be copied from src, starting
221          * at src.  Typically src[len-1] is '\n', unless this is
222          * the incomplete last line.
223          */
224         int i;
225         int add_nl_to_tail = 0;
226         int add_cr_to_tail = 0;
227         int fixed = 0;
228         int last_tab_in_indent = -1;
229         int last_space_in_indent = -1;
230         int need_fix_leading_space = 0;
231         char *buf;
232
233         /*
234          * Strip trailing whitespace
235          */
236         if ((ws_rule & WS_TRAILING_SPACE) &&
237             (2 <= len && isspace(src[len-2]))) {
238                 if (src[len - 1] == '\n') {
239                         add_nl_to_tail = 1;
240                         len--;
241                         if (1 < len && src[len - 1] == '\r') {
242                                 add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
243                                 len--;
244                         }
245                 }
246                 if (0 < len && isspace(src[len - 1])) {
247                         while (0 < len && isspace(src[len-1]))
248                                 len--;
249                         fixed = 1;
250                 }
251         }
252
253         /*
254          * Check leading whitespaces (indent)
255          */
256         for (i = 0; i < len; i++) {
257                 char ch = src[i];
258                 if (ch == '\t') {
259                         last_tab_in_indent = i;
260                         if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
261                             0 <= last_space_in_indent)
262                             need_fix_leading_space = 1;
263                 } else if (ch == ' ') {
264                         last_space_in_indent = i;
265                         if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
266                             8 <= i - last_tab_in_indent)
267                                 need_fix_leading_space = 1;
268                 } else
269                         break;
270         }
271
272         buf = dst;
273         if (need_fix_leading_space) {
274                 /* Process indent ourselves */
275                 int consecutive_spaces = 0;
276                 int last = last_tab_in_indent + 1;
277
278                 if (ws_rule & WS_INDENT_WITH_NON_TAB) {
279                         /* have "last" point at one past the indent */
280                         if (last_tab_in_indent < last_space_in_indent)
281                                 last = last_space_in_indent + 1;
282                         else
283                                 last = last_tab_in_indent + 1;
284                 }
285
286                 /*
287                  * between src[0..last-1], strip the funny spaces,
288                  * updating them to tab as needed.
289                  */
290                 for (i = 0; i < last; i++) {
291                         char ch = src[i];
292                         if (ch != ' ') {
293                                 consecutive_spaces = 0;
294                                 *dst++ = ch;
295                         } else {
296                                 consecutive_spaces++;
297                                 if (consecutive_spaces == 8) {
298                                         *dst++ = '\t';
299                                         consecutive_spaces = 0;
300                                 }
301                         }
302                 }
303                 while (0 < consecutive_spaces--)
304                         *dst++ = ' ';
305                 len -= last;
306                 src += last;
307                 fixed = 1;
308         }
309
310         memcpy(dst, src, len);
311         if (add_cr_to_tail)
312                 dst[len++] = '\r';
313         if (add_nl_to_tail)
314                 dst[len++] = '\n';
315         if (fixed && error_count)
316                 (*error_count)++;
317         return dst + len - buf;
318 }