062ed8a7bfda9e84a91597232e61f7c62d877459
1#include "cache.h"
2#include "commit.h"
3#include "diff.h"
4#include "diffcore.h"
5#include "quote.h"
6struct path_list {
8 struct path_list *next;
9 int len;
10 char *path;
11 unsigned char sha1[20];
12 unsigned char parent_sha1[FLEX_ARRAY][20];
13};
14static int uninteresting(struct diff_filepair *p)
16{
17 if (diff_unmodified_pair(p))
18 return 1;
19 if (!S_ISREG(p->one->mode) || !S_ISREG(p->two->mode))
20 return 1;
21 return 0;
22}
23static struct path_list *intersect_paths(struct path_list *curr,
25 int n, int num_parent)
26{
27 struct diff_queue_struct *q = &diff_queued_diff;
28 struct path_list *p;
29 int i;
30 if (!n) {
32 struct path_list *list = NULL, *tail = NULL;
33 for (i = 0; i < q->nr; i++) {
34 int len;
35 const char *path;
36 if (uninteresting(q->queue[i]))
37 continue;
38 path = q->queue[i]->two->path;
39 len = strlen(path);
40 p = xmalloc(sizeof(*p) + len + 1 + num_parent * 20);
42 p->path = (char*) &(p->parent_sha1[num_parent][0]);
43 memcpy(p->path, path, len);
44 p->path[len] = 0;
45 p->len = len;
46 p->next = NULL;
47 memcpy(p->sha1, q->queue[i]->two->sha1, 20);
48 memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
49 if (!tail)
50 list = tail = p;
51 else {
52 tail->next = p;
53 p = tail;
54 }
55 }
56 return list;
57 }
58 for (p = curr; p; p = p->next) {
60 int found = 0;
61 if (!p->len)
62 continue;
63 for (i = 0; i < q->nr; i++) {
64 const char *path;
65 int len;
66 if (uninteresting(q->queue[i]))
68 continue;
69 path = q->queue[i]->two->path;
70 len = strlen(path);
71 if (len == p->len && !memcmp(path, p->path, len)) {
72 found = 1;
73 memcpy(p->parent_sha1[n],
74 q->queue[i]->one->sha1, 20);
75 break;
76 }
77 }
78 if (!found)
79 p->len = 0;
80 }
81 return curr;
82}
83struct lline {
85 struct lline *next;
86 int len;
87 unsigned long parent_map;
88 char line[FLEX_ARRAY];
89};
90struct sline {
92 struct lline *lost_head, **lost_tail;
93 char *bol;
94 int len;
95 unsigned long flag;
96};
97static char *grab_blob(const unsigned char *sha1, unsigned long *size)
99{
100 char *blob;
101 char type[20];
102 if (!memcmp(sha1, null_sha1, 20)) {
103 /* deleted blob */
104 *size = 0;
105 return xcalloc(1, 1);
106 }
107 blob = read_sha1_file(sha1, type, size);
108 if (strcmp(type, "blob"))
109 die("object '%s' is not a blob!", sha1_to_hex(sha1));
110 return blob;
111}
112#define TMPPATHLEN 50
114#define MAXLINELEN 10240
115static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
117{
118 int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
119 if (fd < 0)
120 die("unable to create temp-file");
121 if (write(fd, blob, size) != size)
122 die("unable to write temp-file");
123 close(fd);
124}
125static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
127{
128 unsigned long size;
129 void *blob;
130 blob = grab_blob(sha1, &size);
131 write_to_temp_file(tmpfile, blob, size);
132 free(blob);
133}
134static int parse_num(char **cp_p, unsigned int *num_p)
136{
137 char *cp = *cp_p;
138 unsigned int num = 0;
139 int read_some;
140 while ('0' <= *cp && *cp <= '9')
142 num = num * 10 + *cp++ - '0';
143 if (!(read_some = cp - *cp_p))
144 return -1;
145 *cp_p = cp;
146 *num_p = num;
147 return 0;
148}
149static int parse_hunk_header(char *line, int len,
151 unsigned int *ob, unsigned int *on,
152 unsigned int *nb, unsigned int *nn)
153{
154 char *cp;
155 cp = line + 4;
156 if (parse_num(&cp, ob)) {
157 bad_line:
158 return error("malformed diff output: %s", line);
159 }
160 if (*cp == ',') {
161 cp++;
162 if (parse_num(&cp, on))
163 goto bad_line;
164 }
165 else
166 *on = 1;
167 if (*cp++ != ' ' || *cp++ != '+')
168 goto bad_line;
169 if (parse_num(&cp, nb))
170 goto bad_line;
171 if (*cp == ',') {
172 cp++;
173 if (parse_num(&cp, nn))
174 goto bad_line;
175 }
176 else
177 *nn = 1;
178 return -!!memcmp(cp, " @@", 3);
179}
180static void append_lost(struct sline *sline, int n, const char *line)
182{
183 struct lline *lline;
184 int len = strlen(line);
185 unsigned long this_mask = (1UL<<n);
186 if (line[len-1] == '\n')
187 len--;
188 /* Check to see if we can squash things */
190 if (sline->lost_head) {
191 struct lline *last_one = NULL;
192 /* We cannot squash it with earlier one */
193 for (lline = sline->lost_head;
194 lline;
195 lline = lline->next)
196 if (lline->parent_map & this_mask)
197 last_one = lline;
198 lline = last_one ? last_one->next : sline->lost_head;
199 while (lline) {
200 if (lline->len == len &&
201 !memcmp(lline->line, line, len)) {
202 lline->parent_map |= this_mask;
203 return;
204 }
205 lline = lline->next;
206 }
207 }
208 lline = xmalloc(sizeof(*lline) + len + 1);
210 lline->len = len;
211 lline->next = NULL;
212 lline->parent_map = this_mask;
213 memcpy(lline->line, line, len);
214 lline->line[len] = 0;
215 if (sline->lost_head)
216 *(sline->lost_tail) = lline;
217 else
218 sline->lost_head = lline;
219 sline->lost_tail = &lline->next;
220}
221static void combine_diff(const unsigned char *parent, const char *ourtmp,
223 struct sline *sline, int cnt, int n)
224{
225 FILE *in;
226 char parent_tmp[TMPPATHLEN];
227 char cmd[TMPPATHLEN * 2 + 1024];
228 char line[MAXLINELEN];
229 unsigned int lno, ob, on, nb, nn;
230 unsigned long pmask = ~(1UL << n);
231 struct sline *lost_bucket = NULL;
232 write_temp_blob(parent_tmp, parent);
234 sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
235 parent_tmp, ourtmp);
236 in = popen(cmd, "r");
237 if (!in)
238 return;
239 lno = 1;
241 while (fgets(line, sizeof(line), in) != NULL) {
242 int len = strlen(line);
243 if (5 < len && !memcmp("@@ -", line, 4)) {
244 if (parse_hunk_header(line, len,
245 &ob, &on, &nb, &nn))
246 break;
247 lno = nb;
248 if (!nb) {
249 /* @@ -1,2 +0,0 @@ to remove the
250 * first two lines...
251 */
252 nb = 1;
253 }
254 lost_bucket = &sline[nb-1]; /* sline is 0 based */
255 continue;
256 }
257 if (!lost_bucket)
258 continue;
259 switch (line[0]) {
260 case '-':
261 append_lost(lost_bucket, n, line+1);
262 break;
263 case '+':
264 sline[lno-1].flag &= pmask;
265 lno++;
266 break;
267 }
268 }
269 fclose(in);
270 unlink(parent_tmp);
271}
272static unsigned long context = 3;
274static char combine_marker = '@';
275static int interesting(struct sline *sline, unsigned long all_mask)
277{
278 return ((sline->flag & all_mask) != all_mask || sline->lost_head);
279}
280static unsigned long line_diff_parents(struct sline *sline, unsigned long all_mask)
282{
283 /*
284 * Look at the line and see from which parents we have difference.
285 * Lower bits of sline->flag records if the parent had this line,
286 * so XOR with all_mask gives us on-bits for parents we have
287 * differences with.
288 */
289 unsigned long parents = (sline->flag ^ all_mask);
290 if (sline->lost_head) {
291 struct lline *ll;
292 for (ll = sline->lost_head; ll; ll = ll->next)
293 parents |= ll->parent_map;
294 }
295 return parents & all_mask;
296}
297static void make_hunks(struct sline *sline, unsigned long cnt,
299 int num_parent, int dense)
300{
301 unsigned long all_mask = (1UL<<num_parent) - 1;
302 unsigned long mark = (1UL<<num_parent);
303 unsigned long i;
304 i = 0;
306 while (i < cnt) {
307 if (interesting(&sline[i], all_mask)) {
308 unsigned long j = (context < i) ? i - context : 0;
309 while (j <= i)
310 sline[j++].flag |= mark;
311 while (++i < cnt) {
312 if (!interesting(&sline[i], all_mask))
313 break;
314 sline[i].flag |= mark;
315 }
316 j = (i + context < cnt) ? i + context : cnt;
317 while (i < j)
318 sline[i++].flag |= mark;
319 continue;
320 }
321 i++;
322 }
323 if (!dense)
324 return;
325 /* Look at each hunk, and if it contains changes from only
327 * one parent, mark that uninteresting.
328 */
329 i = 0;
330 while (i < cnt) {
331 int j, hunk_end, diffs;
332 unsigned long parents;
333 while (i < cnt && !(sline[i].flag & mark))
334 i++;
335 if (cnt <= i)
336 break; /* No more interesting hunks */
337 for (hunk_end = i + 1; hunk_end < cnt; hunk_end++)
338 if (!(sline[hunk_end].flag & mark))
339 break;
340 /* [i..hunk_end) are interesting. Now is it from
341 * only one parent?
342 * If lost lines are only from one parent and
343 * remaining lines existed in parents other than
344 * that parent, then the hunk is not that interesting.
345 */
346 parents = 0;
347 diffs = 0;
348 for (j = i; j < hunk_end; j++)
349 parents |= line_diff_parents(sline + j, all_mask);
350 /* Now, how many bits from [0..num_parent) are on? */
351 for (j = 0; j < num_parent; j++) {
352 if (parents & (1UL<<j))
353 diffs++;
354 }
355 if (diffs < 2) {
356 /* This hunk is not that interesting after all */
357 for (j = i; j < hunk_end; j++)
358 sline[j].flag &= ~mark;
359 }
360 i = hunk_end;
361 }
362}
363static void dump_sline(struct sline *sline, int cnt, int num_parent)
365{
366 unsigned long mark = (1UL<<num_parent);
367 int i;
368 int lno = 0;
369 while (1) {
371 struct sline *sl = &sline[lno];
372 int hunk_end;
373 while (lno < cnt && !(sline[lno].flag & mark))
374 lno++;
375 if (cnt <= lno)
376 break;
377 for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
378 if (!(sline[hunk_end].flag & mark))
379 break;
380 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
381 printf(" +%d,%d ", lno+1, hunk_end-lno);
382 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
383 putchar('\n');
384 while (lno < hunk_end) {
385 struct lline *ll;
386 int j;
387 sl = &sline[lno++];
388 ll = sl->lost_head;
389 while (ll) {
390 for (j = 0; j < num_parent; j++) {
391 if (ll->parent_map & (1UL<<j))
392 putchar('-');
393 else
394 putchar(' ');
395 }
396 putchar(' ');
397 puts(ll->line);
398 ll = ll->next;
399 }
400 for (j = 0; j < num_parent; j++) {
401 if ((1UL<<j) & sl->flag)
402 putchar(' ');
403 else
404 putchar('+');
405 }
406 printf(" %.*s\n", sl->len, sl->bol);
407 }
408 }
409}
410static void show_combined_diff(struct path_list *elem, int num_parent,
412 int dense)
413{
414 unsigned long size, cnt, lno;
415 char *result, *cp, *ep;
416 struct sline *sline; /* survived lines */
417 int i;
418 char ourtmp[TMPPATHLEN];
419 /* Read the result of merge first */
421 result = grab_blob(elem->sha1, &size);
422 write_to_temp_file(ourtmp, result, size);
423 for (cnt = 0, cp = result; cp - result < size; cp++) {
425 if (*cp == '\n')
426 cnt++;
427 }
428 if (result[size-1] != '\n')
429 cnt++; /* incomplete line */
430 sline = xcalloc(cnt, sizeof(*sline));
432 ep = result;
433 sline[0].bol = result;
434 for (lno = 0, cp = result; cp - result < size; cp++) {
435 if (*cp == '\n') {
436 sline[lno].len = cp - sline[lno].bol;
437 sline[lno].flag = (1UL<<num_parent) - 1;
438 lno++;
439 if (lno < cnt)
440 sline[lno].bol = cp + 1;
441 }
442 }
443 if (result[size-1] != '\n') {
444 sline[cnt-1].len = size - (sline[cnt-1].bol - result);
445 sline[cnt-1].flag = (1UL<<num_parent) - 1;
446 }
447 for (i = 0; i < num_parent; i++)
449 combine_diff(elem->parent_sha1[i], ourtmp, sline, cnt, i);
450 make_hunks(sline, cnt, num_parent, dense);
452 dump_sline(sline, cnt, num_parent);
454 unlink(ourtmp);
455 free(result);
456 for (i = 0; i < cnt; i++) {
458 if (sline[i].lost_head) {
459 struct lline *ll = sline[i].lost_head;
460 while (ll) {
461 struct lline *tmp = ll;
462 ll = ll->next;
463 free(tmp);
464 }
465 }
466 }
467 free(sline);
468}
469int diff_tree_combined_merge(const unsigned char *sha1,
471 const char *header,
472 int show_empty_merge, int dense)
473{
474 struct commit *commit = lookup_commit(sha1);
475 struct diff_options diffopts;
476 struct commit_list *parents;
477 struct path_list *p, *paths = NULL;
478 int num_parent, i, num_paths;
479 diff_setup(&diffopts);
481 diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
482 diffopts.recursive = 1;
483 /* count parents */
485 for (parents = commit->parents, num_parent = 0;
486 parents;
487 parents = parents->next, num_parent++)
488 ; /* nothing */
489 /* find set of paths that everybody touches */
491 for (parents = commit->parents, i = 0;
492 parents;
493 parents = parents->next, i++) {
494 struct commit *parent = parents->item;
495 diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
496 &diffopts);
497 paths = intersect_paths(paths, i, num_parent);
498 diff_flush(&diffopts);
499 }
500 /* find out surviving paths */
502 for (num_paths = 0, p = paths; p; p = p->next) {
503 if (p->len)
504 num_paths++;
505 }
506 if (num_paths || show_empty_merge) {
507 puts(header);
508 for (p = paths; p; p = p->next) {
509 if (!p->len)
510 continue;
511 printf("diff --combined ");
512 if (quote_c_style(p->path, NULL, NULL, 0))
513 quote_c_style(p->path, NULL, stdout, 0);
514 else
515 printf("%s", p->path);
516 putchar('\n');
517 show_combined_diff(p, num_parent, dense);
518 }
519 }
520 /* Clean things up */
522 while (paths) {
523 struct path_list *tmp = paths;
524 paths = paths->next;
525 free(tmp);
526 }
527 return 0;
528}