7 static int uninteresting(struct diff_filepair *p)
9 if (diff_unmodified_pair(p))
11 if (!S_ISREG(p->one->mode) || !S_ISREG(p->two->mode))
16 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
18 struct diff_queue_struct *q = &diff_queued_diff;
19 struct combine_diff_path *p;
23 struct combine_diff_path *list = NULL, **tail = &list;
24 for (i = 0; i < q->nr; i++) {
27 if (uninteresting(q->queue[i]))
29 path = q->queue[i]->two->path;
32 p = xmalloc(sizeof(*p) + len + 1 + num_parent * 20);
33 p->path = (char*) &(p->parent_sha1[num_parent][0]);
34 memcpy(p->path, path, len);
38 memcpy(p->sha1, q->queue[i]->two->sha1, 20);
39 memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
46 for (p = curr; p; p = p->next) {
50 for (i = 0; i < q->nr; i++) {
54 if (uninteresting(q->queue[i]))
56 path = q->queue[i]->two->path;
58 if (len == p->len && !memcmp(path, p->path, len)) {
60 memcpy(p->parent_sha1[n],
61 q->queue[i]->one->sha1, 20);
74 unsigned long parent_map;
75 char line[FLEX_ARRAY];
79 struct lline *lost_head, **lost_tail;
85 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
89 if (!memcmp(sha1, null_sha1, 20)) {
94 blob = read_sha1_file(sha1, type, size);
95 if (strcmp(type, "blob"))
96 die("object '%s' is not a blob!", sha1_to_hex(sha1));
100 #define TMPPATHLEN 50
101 #define MAXLINELEN 10240
103 static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
105 int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
107 die("unable to create temp-file");
108 if (write(fd, blob, size) != size)
109 die("unable to write temp-file");
113 static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
117 blob = grab_blob(sha1, &size);
118 write_to_temp_file(tmpfile, blob, size);
122 static int parse_num(char **cp_p, unsigned int *num_p)
125 unsigned int num = 0;
128 while ('0' <= *cp && *cp <= '9')
129 num = num * 10 + *cp++ - '0';
130 if (!(read_some = cp - *cp_p))
137 static int parse_hunk_header(char *line, int len,
138 unsigned int *ob, unsigned int *on,
139 unsigned int *nb, unsigned int *nn)
143 if (parse_num(&cp, ob)) {
145 return error("malformed diff output: %s", line);
149 if (parse_num(&cp, on))
154 if (*cp++ != ' ' || *cp++ != '+')
156 if (parse_num(&cp, nb))
160 if (parse_num(&cp, nn))
165 return -!!memcmp(cp, " @@", 3);
168 static void append_lost(struct sline *sline, int n, const char *line)
171 int len = strlen(line);
172 unsigned long this_mask = (1UL<<n);
173 if (line[len-1] == '\n')
176 /* Check to see if we can squash things */
177 if (sline->lost_head) {
178 struct lline *last_one = NULL;
179 /* We cannot squash it with earlier one */
180 for (lline = sline->lost_head;
183 if (lline->parent_map & this_mask)
185 lline = last_one ? last_one->next : sline->lost_head;
187 if (lline->len == len &&
188 !memcmp(lline->line, line, len)) {
189 lline->parent_map |= this_mask;
196 lline = xmalloc(sizeof(*lline) + len + 1);
199 lline->parent_map = this_mask;
200 memcpy(lline->line, line, len);
201 lline->line[len] = 0;
202 *sline->lost_tail = lline;
203 sline->lost_tail = &lline->next;
206 static void combine_diff(const unsigned char *parent, const char *ourtmp,
207 struct sline *sline, int cnt, int n)
210 char parent_tmp[TMPPATHLEN];
211 char cmd[TMPPATHLEN * 2 + 1024];
212 char line[MAXLINELEN];
213 unsigned int lno, ob, on, nb, nn;
214 unsigned long pmask = ~(1UL << n);
215 struct sline *lost_bucket = NULL;
217 write_temp_blob(parent_tmp, parent);
218 sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
220 in = popen(cmd, "r");
225 while (fgets(line, sizeof(line), in) != NULL) {
226 int len = strlen(line);
227 if (5 < len && !memcmp("@@ -", line, 4)) {
228 if (parse_hunk_header(line, len,
233 /* @@ -1,2 +0,0 @@ to remove the
239 lost_bucket = &sline[nb];
241 lost_bucket = &sline[nb-1];
248 append_lost(lost_bucket, n, line+1);
251 sline[lno-1].flag &= pmask;
260 static unsigned long context = 3;
261 static char combine_marker = '@';
263 static int interesting(struct sline *sline, unsigned long all_mask)
265 return ((sline->flag & all_mask) != all_mask || sline->lost_head);
268 static unsigned long adjust_hunk_tail(struct sline *sline,
269 unsigned long all_mask,
270 unsigned long hunk_begin,
273 /* i points at the first uninteresting line.
274 * If the last line of the hunk was interesting
275 * only because it has some deletion, then
276 * it is not all that interesting for the
277 * purpose of giving trailing context lines.
279 if ((hunk_begin + 1 <= i) &&
280 ((sline[i-1].flag & all_mask) == all_mask))
285 static unsigned long next_interesting(struct sline *sline,
293 !(sline[i].flag & mark) :
294 (sline[i].flag & mark))
301 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
303 unsigned long all_mask = (1UL<<num_parent) - 1;
304 unsigned long mark = (1UL<<num_parent);
307 i = next_interesting(sline, mark, 0, cnt, 0);
312 unsigned long j = (context < i) ? (i - context) : 0;
315 sline[j++].flag |= mark;
318 j = next_interesting(sline, mark, i, cnt, 1);
320 break; /* the rest are all interesting */
322 /* lookahead context lines */
323 k = next_interesting(sline, mark, j, cnt, 0);
324 j = adjust_hunk_tail(sline, all_mask, i, j);
326 if (k < j + context) {
327 /* k is interesting and [j,k) are not, but
328 * paint them interesting because the gap is small.
331 sline[j++].flag |= mark;
336 /* j is the first uninteresting line and there is
337 * no overlap beyond it within context lines.
340 k = (j + context < cnt) ? j + context : cnt;
342 sline[j++].flag |= mark;
347 static int make_hunks(struct sline *sline, unsigned long cnt,
348 int num_parent, int dense)
350 unsigned long all_mask = (1UL<<num_parent) - 1;
351 unsigned long mark = (1UL<<num_parent);
353 int has_interesting = 0;
355 for (i = 0; i < cnt; i++) {
356 if (interesting(&sline[i], all_mask))
357 sline[i].flag |= mark;
359 sline[i].flag &= ~mark;
362 return give_context(sline, cnt, num_parent);
364 /* Look at each hunk, and if we have changes from only one
365 * parent, or the changes are the same from all but one
366 * parent, mark that uninteresting.
370 unsigned long j, hunk_begin, hunk_end;
371 unsigned long same_diff;
372 while (i < cnt && !(sline[i].flag & mark))
375 break; /* No more interesting hunks */
377 for (j = i + 1; j < cnt; j++) {
378 if (!(sline[j].flag & mark)) {
379 /* Look beyond the end to see if there
380 * is an interesting line after this
381 * hunk within context span.
383 unsigned long la; /* lookahead */
385 la = adjust_hunk_tail(sline, all_mask,
387 la = (la + context < cnt) ?
388 (la + context) : cnt;
390 if (sline[la].flag & mark) {
402 /* [i..hunk_end) are interesting. Now is it really
403 * interesting? We check if there are only two versions
404 * and the result matches one of them. That is, we look
406 * (+) line, which records lines added to which parents;
407 * this line appears in the result.
408 * (-) line, which records from what parents the line
409 * was removed; this line does not appear in the result.
410 * then check the set of parents the result has difference
411 * from, from all lines. If there are lines that has
412 * different set of parents that the result has differences
413 * from, that means we have more than two versions.
415 * Even when we have only two versions, if the result does
416 * not match any of the parents, the it should be considered
417 * interesting. In such a case, we would have all '+' line.
418 * After passing the above "two versions" test, that would
419 * appear as "the same set of parents" to be "all parents".
423 for (j = i; j < hunk_end && !has_interesting; j++) {
424 unsigned long this_diff = ~sline[j].flag & all_mask;
425 struct lline *ll = sline[j].lost_head;
427 /* This has some changes. Is it the
431 same_diff = this_diff;
432 else if (same_diff != this_diff) {
437 while (ll && !has_interesting) {
438 /* Lost this line from these parents;
439 * who are they? Are they the same?
441 this_diff = ll->parent_map;
443 same_diff = this_diff;
444 else if (same_diff != this_diff) {
451 if (!has_interesting && same_diff != all_mask) {
452 /* This hunk is not that interesting after all */
453 for (j = hunk_begin; j < hunk_end; j++)
454 sline[j].flag &= ~mark;
459 has_interesting = give_context(sline, cnt, num_parent);
460 return has_interesting;
463 static void dump_sline(struct sline *sline, int cnt, int num_parent)
465 unsigned long mark = (1UL<<num_parent);
470 struct sline *sl = &sline[lno];
472 while (lno < cnt && !(sline[lno].flag & mark))
476 for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
477 if (!(sline[hunk_end].flag & mark))
479 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
480 printf(" +%d,%d ", lno+1, hunk_end-lno);
481 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
483 while (lno < hunk_end) {
489 for (j = 0; j < num_parent; j++) {
490 if (ll->parent_map & (1UL<<j))
498 for (j = 0; j < num_parent; j++) {
499 if ((1UL<<j) & sl->flag)
504 printf("%.*s\n", sl->len, sl->bol);
509 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
512 /* We have already examined parent j and we know parent i
513 * and parent j are the same, so reuse the combined result
514 * of parent j for parent i.
516 unsigned long lno, imask, jmask;
520 for (lno = 0; lno < cnt; lno++) {
521 struct lline *ll = sline->lost_head;
523 if (ll->parent_map & jmask)
524 ll->parent_map |= imask;
527 if (!(sline->flag & jmask))
528 sline->flag &= ~imask;
533 int show_combined_diff(struct combine_diff_path *elem, int num_parent,
534 int dense, const char *header, int show_empty)
536 unsigned long size, cnt, lno;
537 char *result, *cp, *ep;
538 struct sline *sline; /* survived lines */
539 int i, show_hunks, shown_header = 0;
540 char ourtmp_buf[TMPPATHLEN];
541 char *ourtmp = ourtmp_buf;
543 /* Read the result of merge first */
544 if (memcmp(elem->sha1, null_sha1, 20)) {
545 result = grab_blob(elem->sha1, &size);
546 write_to_temp_file(ourtmp, result, size);
552 if (0 <= (fd = open(ourtmp, O_RDONLY)) &&
554 int len = st.st_size;
558 result = xmalloc(len + 1);
560 int done = xread(fd, result+cnt, len-cnt);
564 die("read error '%s'", ourtmp);
574 ourtmp = "/dev/null";
580 for (cnt = 0, cp = result; cp - result < size; cp++) {
584 if (result[size-1] != '\n')
585 cnt++; /* incomplete line */
587 sline = xcalloc(cnt, sizeof(*sline));
589 sline[0].bol = result;
590 for (lno = 0, cp = result; cp - result < size; cp++) {
592 sline[lno].lost_tail = &sline[lno].lost_head;
593 sline[lno].len = cp - sline[lno].bol;
594 sline[lno].flag = (1UL<<num_parent) - 1;
597 sline[lno].bol = cp + 1;
600 if (result[size-1] != '\n') {
601 sline[cnt-1].lost_tail = &sline[cnt-1].lost_head;
602 sline[cnt-1].len = size - (sline[cnt-1].bol - result);
603 sline[cnt-1].flag = (1UL<<num_parent) - 1;
606 for (i = 0; i < num_parent; i++) {
608 for (j = 0; j < i; j++) {
609 if (!memcmp(elem->parent_sha1[i],
610 elem->parent_sha1[j], 20)) {
611 reuse_combine_diff(sline, cnt, i, j);
616 combine_diff(elem->parent_sha1[i], ourtmp, sline,
620 show_hunks = make_hunks(sline, cnt, num_parent, dense);
622 if (header && (show_hunks || show_empty)) {
627 printf("diff --%s ", dense ? "cc" : "combined");
628 if (quote_c_style(elem->path, NULL, NULL, 0))
629 quote_c_style(elem->path, NULL, stdout, 0);
631 printf("%s", elem->path);
634 for (i = 0; i < num_parent; i++) {
637 find_unique_abbrev(elem->parent_sha1[i],
641 find_unique_abbrev(elem->sha1, DEFAULT_ABBREV));
642 dump_sline(sline, cnt, num_parent);
644 if (ourtmp == ourtmp_buf)
648 for (i = 0; i < cnt; i++) {
649 if (sline[i].lost_head) {
650 struct lline *ll = sline[i].lost_head;
652 struct lline *tmp = ll;
662 int diff_tree_combined_merge(const unsigned char *sha1,
664 int show_empty_merge, int dense)
666 struct commit *commit = lookup_commit(sha1);
667 struct diff_options diffopts;
668 struct commit_list *parents;
669 struct combine_diff_path *p, *paths = NULL;
670 int num_parent, i, num_paths;
672 diff_setup(&diffopts);
673 diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
674 diffopts.recursive = 1;
677 for (parents = commit->parents, num_parent = 0;
679 parents = parents->next, num_parent++)
682 /* find set of paths that everybody touches */
683 for (parents = commit->parents, i = 0;
685 parents = parents->next, i++) {
686 struct commit *parent = parents->item;
687 diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
689 paths = intersect_paths(paths, i, num_parent);
690 diff_flush(&diffopts);
693 /* find out surviving paths */
694 for (num_paths = 0, p = paths; p; p = p->next) {
698 if (num_paths || show_empty_merge) {
699 for (p = paths; p; p = p->next) {
702 if (show_combined_diff(p, num_parent, dense, header,
708 /* Clean things up */
710 struct combine_diff_path *tmp = paths;