Merge branch 'jk/ui-color-always-to-auto'
[git/debian.git] / blame.c
blob58a7036847d9be574bbc3863d7ba4deb548628b7
1 #include "cache.h"
2 #include "refs.h"
3 #include "object-store.h"
4 #include "cache-tree.h"
5 #include "mergesort.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "tag.h"
9 #include "blame.h"
10 #include "alloc.h"
11 #include "commit-slab.h"
13 define_commit_slab(blame_suspects, struct blame_origin *);
14 static struct blame_suspects blame_suspects;
16 struct blame_origin *get_blame_suspects(struct commit *commit)
18 struct blame_origin **result;
20 result = blame_suspects_peek(&blame_suspects, commit);
22 return result ? *result : NULL;
25 static void set_blame_suspects(struct commit *commit, struct blame_origin *origin)
27 *blame_suspects_at(&blame_suspects, commit) = origin;
30 void blame_origin_decref(struct blame_origin *o)
32 if (o && --o->refcnt <= 0) {
33 struct blame_origin *p, *l = NULL;
34 if (o->previous)
35 blame_origin_decref(o->previous);
36 free(o->file.ptr);
37 /* Should be present exactly once in commit chain */
38 for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) {
39 if (p == o) {
40 if (l)
41 l->next = p->next;
42 else
43 set_blame_suspects(o->commit, p->next);
44 free(o);
45 return;
48 die("internal error in blame_origin_decref");
53 * Given a commit and a path in it, create a new origin structure.
54 * The callers that add blame to the scoreboard should use
55 * get_origin() to obtain shared, refcounted copy instead of calling
56 * this function directly.
58 static struct blame_origin *make_origin(struct commit *commit, const char *path)
60 struct blame_origin *o;
61 FLEX_ALLOC_STR(o, path, path);
62 o->commit = commit;
63 o->refcnt = 1;
64 o->next = get_blame_suspects(commit);
65 set_blame_suspects(commit, o);
66 return o;
70 * Locate an existing origin or create a new one.
71 * This moves the origin to front position in the commit util list.
73 static struct blame_origin *get_origin(struct commit *commit, const char *path)
75 struct blame_origin *o, *l;
77 for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) {
78 if (!strcmp(o->path, path)) {
79 /* bump to front */
80 if (l) {
81 l->next = o->next;
82 o->next = get_blame_suspects(commit);
83 set_blame_suspects(commit, o);
85 return blame_origin_incref(o);
88 return make_origin(commit, path);
93 static void verify_working_tree_path(struct commit *work_tree, const char *path)
95 struct commit_list *parents;
96 int pos;
98 for (parents = work_tree->parents; parents; parents = parents->next) {
99 const struct object_id *commit_oid = &parents->item->object.oid;
100 struct object_id blob_oid;
101 unsigned mode;
103 if (!get_tree_entry(commit_oid, path, &blob_oid, &mode) &&
104 oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
105 return;
108 pos = cache_name_pos(path, strlen(path));
109 if (pos >= 0)
110 ; /* path is in the index */
111 else if (-1 - pos < active_nr &&
112 !strcmp(active_cache[-1 - pos]->name, path))
113 ; /* path is in the index, unmerged */
114 else
115 die("no such path '%s' in HEAD", path);
118 static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
120 struct commit *parent;
122 parent = lookup_commit_reference(the_repository, oid);
123 if (!parent)
124 die("no such commit %s", oid_to_hex(oid));
125 return &commit_list_insert(parent, tail)->next;
128 static void append_merge_parents(struct commit_list **tail)
130 int merge_head;
131 struct strbuf line = STRBUF_INIT;
133 merge_head = open(git_path_merge_head(the_repository), O_RDONLY);
134 if (merge_head < 0) {
135 if (errno == ENOENT)
136 return;
137 die("cannot open '%s' for reading",
138 git_path_merge_head(the_repository));
141 while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
142 struct object_id oid;
143 if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
144 die("unknown line in '%s': %s",
145 git_path_merge_head(the_repository), line.buf);
146 tail = append_parent(tail, &oid);
148 close(merge_head);
149 strbuf_release(&line);
153 * This isn't as simple as passing sb->buf and sb->len, because we
154 * want to transfer ownership of the buffer to the commit (so we
155 * must use detach).
157 static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb)
159 size_t len;
160 void *buf = strbuf_detach(sb, &len);
161 set_commit_buffer(the_repository, c, buf, len);
165 * Prepare a dummy commit that represents the work tree (or staged) item.
166 * Note that annotating work tree item never works in the reverse.
168 static struct commit *fake_working_tree_commit(struct diff_options *opt,
169 const char *path,
170 const char *contents_from)
172 struct commit *commit;
173 struct blame_origin *origin;
174 struct commit_list **parent_tail, *parent;
175 struct object_id head_oid;
176 struct strbuf buf = STRBUF_INIT;
177 const char *ident;
178 time_t now;
179 int len;
180 struct cache_entry *ce;
181 unsigned mode;
182 struct strbuf msg = STRBUF_INIT;
184 read_cache();
185 time(&now);
186 commit = alloc_commit_node(the_repository);
187 commit->object.parsed = 1;
188 commit->date = now;
189 parent_tail = &commit->parents;
191 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
192 die("no such ref: HEAD");
194 parent_tail = append_parent(parent_tail, &head_oid);
195 append_merge_parents(parent_tail);
196 verify_working_tree_path(commit, path);
198 origin = make_origin(commit, path);
200 ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
201 strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
202 for (parent = commit->parents; parent; parent = parent->next)
203 strbuf_addf(&msg, "parent %s\n",
204 oid_to_hex(&parent->item->object.oid));
205 strbuf_addf(&msg,
206 "author %s\n"
207 "committer %s\n\n"
208 "Version of %s from %s\n",
209 ident, ident, path,
210 (!contents_from ? path :
211 (!strcmp(contents_from, "-") ? "standard input" : contents_from)));
212 set_commit_buffer_from_strbuf(commit, &msg);
214 if (!contents_from || strcmp("-", contents_from)) {
215 struct stat st;
216 const char *read_from;
217 char *buf_ptr;
218 unsigned long buf_len;
220 if (contents_from) {
221 if (stat(contents_from, &st) < 0)
222 die_errno("Cannot stat '%s'", contents_from);
223 read_from = contents_from;
225 else {
226 if (lstat(path, &st) < 0)
227 die_errno("Cannot lstat '%s'", path);
228 read_from = path;
230 mode = canon_mode(st.st_mode);
232 switch (st.st_mode & S_IFMT) {
233 case S_IFREG:
234 if (opt->flags.allow_textconv &&
235 textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
236 strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
237 else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
238 die_errno("cannot open or read '%s'", read_from);
239 break;
240 case S_IFLNK:
241 if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
242 die_errno("cannot readlink '%s'", read_from);
243 break;
244 default:
245 die("unsupported file type %s", read_from);
248 else {
249 /* Reading from stdin */
250 mode = 0;
251 if (strbuf_read(&buf, 0, 0) < 0)
252 die_errno("failed to read from stdin");
254 convert_to_git(&the_index, path, buf.buf, buf.len, &buf, 0);
255 origin->file.ptr = buf.buf;
256 origin->file.size = buf.len;
257 pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid);
260 * Read the current index, replace the path entry with
261 * origin->blob_sha1 without mucking with its mode or type
262 * bits; we are not going to write this index out -- we just
263 * want to run "diff-index --cached".
265 discard_cache();
266 read_cache();
268 len = strlen(path);
269 if (!mode) {
270 int pos = cache_name_pos(path, len);
271 if (0 <= pos)
272 mode = active_cache[pos]->ce_mode;
273 else
274 /* Let's not bother reading from HEAD tree */
275 mode = S_IFREG | 0644;
277 ce = make_empty_cache_entry(&the_index, len);
278 oidcpy(&ce->oid, &origin->blob_oid);
279 memcpy(ce->name, path, len);
280 ce->ce_flags = create_ce_flags(0);
281 ce->ce_namelen = len;
282 ce->ce_mode = create_ce_mode(mode);
283 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
285 cache_tree_invalidate_path(&the_index, path);
287 return commit;
292 static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
293 xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts)
295 xpparam_t xpp = {0};
296 xdemitconf_t xecfg = {0};
297 xdemitcb_t ecb = {NULL};
299 xpp.flags = xdl_opts;
300 xecfg.hunk_func = hunk_func;
301 ecb.priv = cb_data;
302 return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
306 * Given an origin, prepare mmfile_t structure to be used by the
307 * diff machinery
309 static void fill_origin_blob(struct diff_options *opt,
310 struct blame_origin *o, mmfile_t *file, int *num_read_blob)
312 if (!o->file.ptr) {
313 enum object_type type;
314 unsigned long file_size;
316 (*num_read_blob)++;
317 if (opt->flags.allow_textconv &&
318 textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
320 else
321 file->ptr = read_object_file(&o->blob_oid, &type,
322 &file_size);
323 file->size = file_size;
325 if (!file->ptr)
326 die("Cannot read blob %s for path %s",
327 oid_to_hex(&o->blob_oid),
328 o->path);
329 o->file = *file;
331 else
332 *file = o->file;
335 static void drop_origin_blob(struct blame_origin *o)
337 if (o->file.ptr) {
338 FREE_AND_NULL(o->file.ptr);
343 * Any merge of blames happens on lists of blames that arrived via
344 * different parents in a single suspect. In this case, we want to
345 * sort according to the suspect line numbers as opposed to the final
346 * image line numbers. The function body is somewhat longish because
347 * it avoids unnecessary writes.
350 static struct blame_entry *blame_merge(struct blame_entry *list1,
351 struct blame_entry *list2)
353 struct blame_entry *p1 = list1, *p2 = list2,
354 **tail = &list1;
356 if (!p1)
357 return p2;
358 if (!p2)
359 return p1;
361 if (p1->s_lno <= p2->s_lno) {
362 do {
363 tail = &p1->next;
364 if ((p1 = *tail) == NULL) {
365 *tail = p2;
366 return list1;
368 } while (p1->s_lno <= p2->s_lno);
370 for (;;) {
371 *tail = p2;
372 do {
373 tail = &p2->next;
374 if ((p2 = *tail) == NULL) {
375 *tail = p1;
376 return list1;
378 } while (p1->s_lno > p2->s_lno);
379 *tail = p1;
380 do {
381 tail = &p1->next;
382 if ((p1 = *tail) == NULL) {
383 *tail = p2;
384 return list1;
386 } while (p1->s_lno <= p2->s_lno);
390 static void *get_next_blame(const void *p)
392 return ((struct blame_entry *)p)->next;
395 static void set_next_blame(void *p1, void *p2)
397 ((struct blame_entry *)p1)->next = p2;
401 * Final image line numbers are all different, so we don't need a
402 * three-way comparison here.
405 static int compare_blame_final(const void *p1, const void *p2)
407 return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
408 ? 1 : -1;
411 static int compare_blame_suspect(const void *p1, const void *p2)
413 const struct blame_entry *s1 = p1, *s2 = p2;
415 * to allow for collating suspects, we sort according to the
416 * respective pointer value as the primary sorting criterion.
417 * The actual relation is pretty unimportant as long as it
418 * establishes a total order. Comparing as integers gives us
419 * that.
421 if (s1->suspect != s2->suspect)
422 return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
423 if (s1->s_lno == s2->s_lno)
424 return 0;
425 return s1->s_lno > s2->s_lno ? 1 : -1;
428 void blame_sort_final(struct blame_scoreboard *sb)
430 sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
431 compare_blame_final);
434 static int compare_commits_by_reverse_commit_date(const void *a,
435 const void *b,
436 void *c)
438 return -compare_commits_by_commit_date(a, b, c);
442 * For debugging -- origin is refcounted, and this asserts that
443 * we do not underflow.
445 static void sanity_check_refcnt(struct blame_scoreboard *sb)
447 int baa = 0;
448 struct blame_entry *ent;
450 for (ent = sb->ent; ent; ent = ent->next) {
451 /* Nobody should have zero or negative refcnt */
452 if (ent->suspect->refcnt <= 0) {
453 fprintf(stderr, "%s in %s has negative refcnt %d\n",
454 ent->suspect->path,
455 oid_to_hex(&ent->suspect->commit->object.oid),
456 ent->suspect->refcnt);
457 baa = 1;
460 if (baa)
461 sb->on_sanity_fail(sb, baa);
465 * If two blame entries that are next to each other came from
466 * contiguous lines in the same origin (i.e. <commit, path> pair),
467 * merge them together.
469 void blame_coalesce(struct blame_scoreboard *sb)
471 struct blame_entry *ent, *next;
473 for (ent = sb->ent; ent && (next = ent->next); ent = next) {
474 if (ent->suspect == next->suspect &&
475 ent->s_lno + ent->num_lines == next->s_lno) {
476 ent->num_lines += next->num_lines;
477 ent->next = next->next;
478 blame_origin_decref(next->suspect);
479 free(next);
480 ent->score = 0;
481 next = ent; /* again */
485 if (sb->debug) /* sanity */
486 sanity_check_refcnt(sb);
490 * Merge the given sorted list of blames into a preexisting origin.
491 * If there were no previous blames to that commit, it is entered into
492 * the commit priority queue of the score board.
495 static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin,
496 struct blame_entry *sorted)
498 if (porigin->suspects)
499 porigin->suspects = blame_merge(porigin->suspects, sorted);
500 else {
501 struct blame_origin *o;
502 for (o = get_blame_suspects(porigin->commit); o; o = o->next) {
503 if (o->suspects) {
504 porigin->suspects = sorted;
505 return;
508 porigin->suspects = sorted;
509 prio_queue_put(&sb->commits, porigin->commit);
514 * Fill the blob_sha1 field of an origin if it hasn't, so that later
515 * call to fill_origin_blob() can use it to locate the data. blob_sha1
516 * for an origin is also used to pass the blame for the entire file to
517 * the parent to detect the case where a child's blob is identical to
518 * that of its parent's.
520 * This also fills origin->mode for corresponding tree path.
522 static int fill_blob_sha1_and_mode(struct blame_origin *origin)
524 if (!is_null_oid(&origin->blob_oid))
525 return 0;
526 if (get_tree_entry(&origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode))
527 goto error_out;
528 if (oid_object_info(the_repository, &origin->blob_oid, NULL) != OBJ_BLOB)
529 goto error_out;
530 return 0;
531 error_out:
532 oidclr(&origin->blob_oid);
533 origin->mode = S_IFINVALID;
534 return -1;
538 * We have an origin -- check if the same path exists in the
539 * parent and return an origin structure to represent it.
541 static struct blame_origin *find_origin(struct commit *parent,
542 struct blame_origin *origin)
544 struct blame_origin *porigin;
545 struct diff_options diff_opts;
546 const char *paths[2];
548 /* First check any existing origins */
549 for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next)
550 if (!strcmp(porigin->path, origin->path)) {
552 * The same path between origin and its parent
553 * without renaming -- the most common case.
555 return blame_origin_incref (porigin);
558 /* See if the origin->path is different between parent
559 * and origin first. Most of the time they are the
560 * same and diff-tree is fairly efficient about this.
562 diff_setup(&diff_opts);
563 diff_opts.flags.recursive = 1;
564 diff_opts.detect_rename = 0;
565 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
566 paths[0] = origin->path;
567 paths[1] = NULL;
569 parse_pathspec(&diff_opts.pathspec,
570 PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
571 PATHSPEC_LITERAL_PATH, "", paths);
572 diff_setup_done(&diff_opts);
574 if (is_null_oid(&origin->commit->object.oid))
575 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
576 else
577 diff_tree_oid(get_commit_tree_oid(parent),
578 get_commit_tree_oid(origin->commit),
579 "", &diff_opts);
580 diffcore_std(&diff_opts);
582 if (!diff_queued_diff.nr) {
583 /* The path is the same as parent */
584 porigin = get_origin(parent, origin->path);
585 oidcpy(&porigin->blob_oid, &origin->blob_oid);
586 porigin->mode = origin->mode;
587 } else {
589 * Since origin->path is a pathspec, if the parent
590 * commit had it as a directory, we will see a whole
591 * bunch of deletion of files in the directory that we
592 * do not care about.
594 int i;
595 struct diff_filepair *p = NULL;
596 for (i = 0; i < diff_queued_diff.nr; i++) {
597 const char *name;
598 p = diff_queued_diff.queue[i];
599 name = p->one->path ? p->one->path : p->two->path;
600 if (!strcmp(name, origin->path))
601 break;
603 if (!p)
604 die("internal error in blame::find_origin");
605 switch (p->status) {
606 default:
607 die("internal error in blame::find_origin (%c)",
608 p->status);
609 case 'M':
610 porigin = get_origin(parent, origin->path);
611 oidcpy(&porigin->blob_oid, &p->one->oid);
612 porigin->mode = p->one->mode;
613 break;
614 case 'A':
615 case 'T':
616 /* Did not exist in parent, or type changed */
617 break;
620 diff_flush(&diff_opts);
621 clear_pathspec(&diff_opts.pathspec);
622 return porigin;
626 * We have an origin -- find the path that corresponds to it in its
627 * parent and return an origin structure to represent it.
629 static struct blame_origin *find_rename(struct commit *parent,
630 struct blame_origin *origin)
632 struct blame_origin *porigin = NULL;
633 struct diff_options diff_opts;
634 int i;
636 diff_setup(&diff_opts);
637 diff_opts.flags.recursive = 1;
638 diff_opts.detect_rename = DIFF_DETECT_RENAME;
639 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
640 diff_opts.single_follow = origin->path;
641 diff_setup_done(&diff_opts);
643 if (is_null_oid(&origin->commit->object.oid))
644 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
645 else
646 diff_tree_oid(get_commit_tree_oid(parent),
647 get_commit_tree_oid(origin->commit),
648 "", &diff_opts);
649 diffcore_std(&diff_opts);
651 for (i = 0; i < diff_queued_diff.nr; i++) {
652 struct diff_filepair *p = diff_queued_diff.queue[i];
653 if ((p->status == 'R' || p->status == 'C') &&
654 !strcmp(p->two->path, origin->path)) {
655 porigin = get_origin(parent, p->one->path);
656 oidcpy(&porigin->blob_oid, &p->one->oid);
657 porigin->mode = p->one->mode;
658 break;
661 diff_flush(&diff_opts);
662 clear_pathspec(&diff_opts.pathspec);
663 return porigin;
667 * Append a new blame entry to a given output queue.
669 static void add_blame_entry(struct blame_entry ***queue,
670 const struct blame_entry *src)
672 struct blame_entry *e = xmalloc(sizeof(*e));
673 memcpy(e, src, sizeof(*e));
674 blame_origin_incref(e->suspect);
676 e->next = **queue;
677 **queue = e;
678 *queue = &e->next;
682 * src typically is on-stack; we want to copy the information in it to
683 * a malloced blame_entry that gets added to the given queue. The
684 * origin of dst loses a refcnt.
686 static void dup_entry(struct blame_entry ***queue,
687 struct blame_entry *dst, struct blame_entry *src)
689 blame_origin_incref(src->suspect);
690 blame_origin_decref(dst->suspect);
691 memcpy(dst, src, sizeof(*src));
692 dst->next = **queue;
693 **queue = dst;
694 *queue = &dst->next;
697 const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
699 return sb->final_buf + sb->lineno[lno];
703 * It is known that lines between tlno to same came from parent, and e
704 * has an overlap with that range. it also is known that parent's
705 * line plno corresponds to e's line tlno.
707 * <---- e ----->
708 * <------>
709 * <------------>
710 * <------------>
711 * <------------------>
713 * Split e into potentially three parts; before this chunk, the chunk
714 * to be blamed for the parent, and after that portion.
716 static void split_overlap(struct blame_entry *split,
717 struct blame_entry *e,
718 int tlno, int plno, int same,
719 struct blame_origin *parent)
721 int chunk_end_lno;
722 memset(split, 0, sizeof(struct blame_entry [3]));
724 if (e->s_lno < tlno) {
725 /* there is a pre-chunk part not blamed on parent */
726 split[0].suspect = blame_origin_incref(e->suspect);
727 split[0].lno = e->lno;
728 split[0].s_lno = e->s_lno;
729 split[0].num_lines = tlno - e->s_lno;
730 split[1].lno = e->lno + tlno - e->s_lno;
731 split[1].s_lno = plno;
733 else {
734 split[1].lno = e->lno;
735 split[1].s_lno = plno + (e->s_lno - tlno);
738 if (same < e->s_lno + e->num_lines) {
739 /* there is a post-chunk part not blamed on parent */
740 split[2].suspect = blame_origin_incref(e->suspect);
741 split[2].lno = e->lno + (same - e->s_lno);
742 split[2].s_lno = e->s_lno + (same - e->s_lno);
743 split[2].num_lines = e->s_lno + e->num_lines - same;
744 chunk_end_lno = split[2].lno;
746 else
747 chunk_end_lno = e->lno + e->num_lines;
748 split[1].num_lines = chunk_end_lno - split[1].lno;
751 * if it turns out there is nothing to blame the parent for,
752 * forget about the splitting. !split[1].suspect signals this.
754 if (split[1].num_lines < 1)
755 return;
756 split[1].suspect = blame_origin_incref(parent);
760 * split_overlap() divided an existing blame e into up to three parts
761 * in split. Any assigned blame is moved to queue to
762 * reflect the split.
764 static void split_blame(struct blame_entry ***blamed,
765 struct blame_entry ***unblamed,
766 struct blame_entry *split,
767 struct blame_entry *e)
769 if (split[0].suspect && split[2].suspect) {
770 /* The first part (reuse storage for the existing entry e) */
771 dup_entry(unblamed, e, &split[0]);
773 /* The last part -- me */
774 add_blame_entry(unblamed, &split[2]);
776 /* ... and the middle part -- parent */
777 add_blame_entry(blamed, &split[1]);
779 else if (!split[0].suspect && !split[2].suspect)
781 * The parent covers the entire area; reuse storage for
782 * e and replace it with the parent.
784 dup_entry(blamed, e, &split[1]);
785 else if (split[0].suspect) {
786 /* me and then parent */
787 dup_entry(unblamed, e, &split[0]);
788 add_blame_entry(blamed, &split[1]);
790 else {
791 /* parent and then me */
792 dup_entry(blamed, e, &split[1]);
793 add_blame_entry(unblamed, &split[2]);
798 * After splitting the blame, the origins used by the
799 * on-stack blame_entry should lose one refcnt each.
801 static void decref_split(struct blame_entry *split)
803 int i;
805 for (i = 0; i < 3; i++)
806 blame_origin_decref(split[i].suspect);
810 * reverse_blame reverses the list given in head, appending tail.
811 * That allows us to build lists in reverse order, then reverse them
812 * afterwards. This can be faster than building the list in proper
813 * order right away. The reason is that building in proper order
814 * requires writing a link in the _previous_ element, while building
815 * in reverse order just requires placing the list head into the
816 * _current_ element.
819 static struct blame_entry *reverse_blame(struct blame_entry *head,
820 struct blame_entry *tail)
822 while (head) {
823 struct blame_entry *next = head->next;
824 head->next = tail;
825 tail = head;
826 head = next;
828 return tail;
832 * Process one hunk from the patch between the current suspect for
833 * blame_entry e and its parent. This first blames any unfinished
834 * entries before the chunk (which is where target and parent start
835 * differing) on the parent, and then splits blame entries at the
836 * start and at the end of the difference region. Since use of -M and
837 * -C options may lead to overlapping/duplicate source line number
838 * ranges, all we can rely on from sorting/merging is the order of the
839 * first suspect line number.
841 static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
842 int tlno, int offset, int same,
843 struct blame_origin *parent)
845 struct blame_entry *e = **srcq;
846 struct blame_entry *samep = NULL, *diffp = NULL;
848 while (e && e->s_lno < tlno) {
849 struct blame_entry *next = e->next;
851 * current record starts before differing portion. If
852 * it reaches into it, we need to split it up and
853 * examine the second part separately.
855 if (e->s_lno + e->num_lines > tlno) {
856 /* Move second half to a new record */
857 int len = tlno - e->s_lno;
858 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
859 n->suspect = e->suspect;
860 n->lno = e->lno + len;
861 n->s_lno = e->s_lno + len;
862 n->num_lines = e->num_lines - len;
863 e->num_lines = len;
864 e->score = 0;
865 /* Push new record to diffp */
866 n->next = diffp;
867 diffp = n;
868 } else
869 blame_origin_decref(e->suspect);
870 /* Pass blame for everything before the differing
871 * chunk to the parent */
872 e->suspect = blame_origin_incref(parent);
873 e->s_lno += offset;
874 e->next = samep;
875 samep = e;
876 e = next;
879 * As we don't know how much of a common stretch after this
880 * diff will occur, the currently blamed parts are all that we
881 * can assign to the parent for now.
884 if (samep) {
885 **dstq = reverse_blame(samep, **dstq);
886 *dstq = &samep->next;
889 * Prepend the split off portions: everything after e starts
890 * after the blameable portion.
892 e = reverse_blame(diffp, e);
895 * Now retain records on the target while parts are different
896 * from the parent.
898 samep = NULL;
899 diffp = NULL;
900 while (e && e->s_lno < same) {
901 struct blame_entry *next = e->next;
904 * If current record extends into sameness, need to split.
906 if (e->s_lno + e->num_lines > same) {
908 * Move second half to a new record to be
909 * processed by later chunks
911 int len = same - e->s_lno;
912 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
913 n->suspect = blame_origin_incref(e->suspect);
914 n->lno = e->lno + len;
915 n->s_lno = e->s_lno + len;
916 n->num_lines = e->num_lines - len;
917 e->num_lines = len;
918 e->score = 0;
919 /* Push new record to samep */
920 n->next = samep;
921 samep = n;
923 e->next = diffp;
924 diffp = e;
925 e = next;
927 **srcq = reverse_blame(diffp, reverse_blame(samep, e));
928 /* Move across elements that are in the unblamable portion */
929 if (diffp)
930 *srcq = &diffp->next;
933 struct blame_chunk_cb_data {
934 struct blame_origin *parent;
935 long offset;
936 struct blame_entry **dstq;
937 struct blame_entry **srcq;
940 /* diff chunks are from parent to target */
941 static int blame_chunk_cb(long start_a, long count_a,
942 long start_b, long count_b, void *data)
944 struct blame_chunk_cb_data *d = data;
945 if (start_a - start_b != d->offset)
946 die("internal error in blame::blame_chunk_cb");
947 blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
948 start_b + count_b, d->parent);
949 d->offset = start_a + count_a - (start_b + count_b);
950 return 0;
954 * We are looking at the origin 'target' and aiming to pass blame
955 * for the lines it is suspected to its parent. Run diff to find
956 * which lines came from parent and pass blame for them.
958 static void pass_blame_to_parent(struct blame_scoreboard *sb,
959 struct blame_origin *target,
960 struct blame_origin *parent)
962 mmfile_t file_p, file_o;
963 struct blame_chunk_cb_data d;
964 struct blame_entry *newdest = NULL;
966 if (!target->suspects)
967 return; /* nothing remains for this target */
969 d.parent = parent;
970 d.offset = 0;
971 d.dstq = &newdest; d.srcq = &target->suspects;
973 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
974 fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
975 sb->num_get_patch++;
977 if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
978 die("unable to generate diff (%s -> %s)",
979 oid_to_hex(&parent->commit->object.oid),
980 oid_to_hex(&target->commit->object.oid));
981 /* The rest are the same as the parent */
982 blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
983 *d.dstq = NULL;
984 queue_blames(sb, parent, newdest);
986 return;
990 * The lines in blame_entry after splitting blames many times can become
991 * very small and trivial, and at some point it becomes pointless to
992 * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any
993 * ordinary C program, and it is not worth to say it was copied from
994 * totally unrelated file in the parent.
996 * Compute how trivial the lines in the blame_entry are.
998 unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
1000 unsigned score;
1001 const char *cp, *ep;
1003 if (e->score)
1004 return e->score;
1006 score = 1;
1007 cp = blame_nth_line(sb, e->lno);
1008 ep = blame_nth_line(sb, e->lno + e->num_lines);
1009 while (cp < ep) {
1010 unsigned ch = *((unsigned char *)cp);
1011 if (isalnum(ch))
1012 score++;
1013 cp++;
1015 e->score = score;
1016 return score;
1020 * best_so_far[] and potential[] are both a split of an existing blame_entry
1021 * that passes blame to the parent. Maintain best_so_far the best split so
1022 * far, by comparing potential and best_so_far and copying potential into
1023 * bst_so_far as needed.
1025 static void copy_split_if_better(struct blame_scoreboard *sb,
1026 struct blame_entry *best_so_far,
1027 struct blame_entry *potential)
1029 int i;
1031 if (!potential[1].suspect)
1032 return;
1033 if (best_so_far[1].suspect) {
1034 if (blame_entry_score(sb, &potential[1]) <
1035 blame_entry_score(sb, &best_so_far[1]))
1036 return;
1039 for (i = 0; i < 3; i++)
1040 blame_origin_incref(potential[i].suspect);
1041 decref_split(best_so_far);
1042 memcpy(best_so_far, potential, sizeof(struct blame_entry[3]));
1046 * We are looking at a part of the final image represented by
1047 * ent (tlno and same are offset by ent->s_lno).
1048 * tlno is where we are looking at in the final image.
1049 * up to (but not including) same match preimage.
1050 * plno is where we are looking at in the preimage.
1052 * <-------------- final image ---------------------->
1053 * <------ent------>
1054 * ^tlno ^same
1055 * <---------preimage----->
1056 * ^plno
1058 * All line numbers are 0-based.
1060 static void handle_split(struct blame_scoreboard *sb,
1061 struct blame_entry *ent,
1062 int tlno, int plno, int same,
1063 struct blame_origin *parent,
1064 struct blame_entry *split)
1066 if (ent->num_lines <= tlno)
1067 return;
1068 if (tlno < same) {
1069 struct blame_entry potential[3];
1070 tlno += ent->s_lno;
1071 same += ent->s_lno;
1072 split_overlap(potential, ent, tlno, plno, same, parent);
1073 copy_split_if_better(sb, split, potential);
1074 decref_split(potential);
1078 struct handle_split_cb_data {
1079 struct blame_scoreboard *sb;
1080 struct blame_entry *ent;
1081 struct blame_origin *parent;
1082 struct blame_entry *split;
1083 long plno;
1084 long tlno;
1087 static int handle_split_cb(long start_a, long count_a,
1088 long start_b, long count_b, void *data)
1090 struct handle_split_cb_data *d = data;
1091 handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
1092 d->split);
1093 d->plno = start_a + count_a;
1094 d->tlno = start_b + count_b;
1095 return 0;
1099 * Find the lines from parent that are the same as ent so that
1100 * we can pass blames to it. file_p has the blob contents for
1101 * the parent.
1103 static void find_copy_in_blob(struct blame_scoreboard *sb,
1104 struct blame_entry *ent,
1105 struct blame_origin *parent,
1106 struct blame_entry *split,
1107 mmfile_t *file_p)
1109 const char *cp;
1110 mmfile_t file_o;
1111 struct handle_split_cb_data d;
1113 memset(&d, 0, sizeof(d));
1114 d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
1116 * Prepare mmfile that contains only the lines in ent.
1118 cp = blame_nth_line(sb, ent->lno);
1119 file_o.ptr = (char *) cp;
1120 file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
1123 * file_o is a part of final image we are annotating.
1124 * file_p partially may match that image.
1126 memset(split, 0, sizeof(struct blame_entry [3]));
1127 if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
1128 die("unable to generate diff (%s)",
1129 oid_to_hex(&parent->commit->object.oid));
1130 /* remainder, if any, all match the preimage */
1131 handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
1134 /* Move all blame entries from list *source that have a score smaller
1135 * than score_min to the front of list *small.
1136 * Returns a pointer to the link pointing to the old head of the small list.
1139 static struct blame_entry **filter_small(struct blame_scoreboard *sb,
1140 struct blame_entry **small,
1141 struct blame_entry **source,
1142 unsigned score_min)
1144 struct blame_entry *p = *source;
1145 struct blame_entry *oldsmall = *small;
1146 while (p) {
1147 if (blame_entry_score(sb, p) <= score_min) {
1148 *small = p;
1149 small = &p->next;
1150 p = *small;
1151 } else {
1152 *source = p;
1153 source = &p->next;
1154 p = *source;
1157 *small = oldsmall;
1158 *source = NULL;
1159 return small;
1163 * See if lines currently target is suspected for can be attributed to
1164 * parent.
1166 static void find_move_in_parent(struct blame_scoreboard *sb,
1167 struct blame_entry ***blamed,
1168 struct blame_entry **toosmall,
1169 struct blame_origin *target,
1170 struct blame_origin *parent)
1172 struct blame_entry *e, split[3];
1173 struct blame_entry *unblamed = target->suspects;
1174 struct blame_entry *leftover = NULL;
1175 mmfile_t file_p;
1177 if (!unblamed)
1178 return; /* nothing remains for this target */
1180 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
1181 if (!file_p.ptr)
1182 return;
1184 /* At each iteration, unblamed has a NULL-terminated list of
1185 * entries that have not yet been tested for blame. leftover
1186 * contains the reversed list of entries that have been tested
1187 * without being assignable to the parent.
1189 do {
1190 struct blame_entry **unblamedtail = &unblamed;
1191 struct blame_entry *next;
1192 for (e = unblamed; e; e = next) {
1193 next = e->next;
1194 find_copy_in_blob(sb, e, parent, split, &file_p);
1195 if (split[1].suspect &&
1196 sb->move_score < blame_entry_score(sb, &split[1])) {
1197 split_blame(blamed, &unblamedtail, split, e);
1198 } else {
1199 e->next = leftover;
1200 leftover = e;
1202 decref_split(split);
1204 *unblamedtail = NULL;
1205 toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);
1206 } while (unblamed);
1207 target->suspects = reverse_blame(leftover, NULL);
1210 struct blame_list {
1211 struct blame_entry *ent;
1212 struct blame_entry split[3];
1216 * Count the number of entries the target is suspected for,
1217 * and prepare a list of entry and the best split.
1219 static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
1220 int *num_ents_p)
1222 struct blame_entry *e;
1223 int num_ents, i;
1224 struct blame_list *blame_list = NULL;
1226 for (e = unblamed, num_ents = 0; e; e = e->next)
1227 num_ents++;
1228 if (num_ents) {
1229 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1230 for (e = unblamed, i = 0; e; e = e->next)
1231 blame_list[i++].ent = e;
1233 *num_ents_p = num_ents;
1234 return blame_list;
1238 * For lines target is suspected for, see if we can find code movement
1239 * across file boundary from the parent commit. porigin is the path
1240 * in the parent we already tried.
1242 static void find_copy_in_parent(struct blame_scoreboard *sb,
1243 struct blame_entry ***blamed,
1244 struct blame_entry **toosmall,
1245 struct blame_origin *target,
1246 struct commit *parent,
1247 struct blame_origin *porigin,
1248 int opt)
1250 struct diff_options diff_opts;
1251 int i, j;
1252 struct blame_list *blame_list;
1253 int num_ents;
1254 struct blame_entry *unblamed = target->suspects;
1255 struct blame_entry *leftover = NULL;
1257 if (!unblamed)
1258 return; /* nothing remains for this target */
1260 diff_setup(&diff_opts);
1261 diff_opts.flags.recursive = 1;
1262 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1264 diff_setup_done(&diff_opts);
1266 /* Try "find copies harder" on new path if requested;
1267 * we do not want to use diffcore_rename() actually to
1268 * match things up; find_copies_harder is set only to
1269 * force diff_tree_oid() to feed all filepairs to diff_queue,
1270 * and this code needs to be after diff_setup_done(), which
1271 * usually makes find-copies-harder imply copy detection.
1273 if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1274 || ((opt & PICKAXE_BLAME_COPY_HARDER)
1275 && (!porigin || strcmp(target->path, porigin->path))))
1276 diff_opts.flags.find_copies_harder = 1;
1278 if (is_null_oid(&target->commit->object.oid))
1279 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
1280 else
1281 diff_tree_oid(get_commit_tree_oid(parent),
1282 get_commit_tree_oid(target->commit),
1283 "", &diff_opts);
1285 if (!diff_opts.flags.find_copies_harder)
1286 diffcore_std(&diff_opts);
1288 do {
1289 struct blame_entry **unblamedtail = &unblamed;
1290 blame_list = setup_blame_list(unblamed, &num_ents);
1292 for (i = 0; i < diff_queued_diff.nr; i++) {
1293 struct diff_filepair *p = diff_queued_diff.queue[i];
1294 struct blame_origin *norigin;
1295 mmfile_t file_p;
1296 struct blame_entry potential[3];
1298 if (!DIFF_FILE_VALID(p->one))
1299 continue; /* does not exist in parent */
1300 if (S_ISGITLINK(p->one->mode))
1301 continue; /* ignore git links */
1302 if (porigin && !strcmp(p->one->path, porigin->path))
1303 /* find_move already dealt with this path */
1304 continue;
1306 norigin = get_origin(parent, p->one->path);
1307 oidcpy(&norigin->blob_oid, &p->one->oid);
1308 norigin->mode = p->one->mode;
1309 fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
1310 if (!file_p.ptr)
1311 continue;
1313 for (j = 0; j < num_ents; j++) {
1314 find_copy_in_blob(sb, blame_list[j].ent,
1315 norigin, potential, &file_p);
1316 copy_split_if_better(sb, blame_list[j].split,
1317 potential);
1318 decref_split(potential);
1320 blame_origin_decref(norigin);
1323 for (j = 0; j < num_ents; j++) {
1324 struct blame_entry *split = blame_list[j].split;
1325 if (split[1].suspect &&
1326 sb->copy_score < blame_entry_score(sb, &split[1])) {
1327 split_blame(blamed, &unblamedtail, split,
1328 blame_list[j].ent);
1329 } else {
1330 blame_list[j].ent->next = leftover;
1331 leftover = blame_list[j].ent;
1333 decref_split(split);
1335 free(blame_list);
1336 *unblamedtail = NULL;
1337 toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);
1338 } while (unblamed);
1339 target->suspects = reverse_blame(leftover, NULL);
1340 diff_flush(&diff_opts);
1341 clear_pathspec(&diff_opts.pathspec);
1345 * The blobs of origin and porigin exactly match, so everything
1346 * origin is suspected for can be blamed on the parent.
1348 static void pass_whole_blame(struct blame_scoreboard *sb,
1349 struct blame_origin *origin, struct blame_origin *porigin)
1351 struct blame_entry *e, *suspects;
1353 if (!porigin->file.ptr && origin->file.ptr) {
1354 /* Steal its file */
1355 porigin->file = origin->file;
1356 origin->file.ptr = NULL;
1358 suspects = origin->suspects;
1359 origin->suspects = NULL;
1360 for (e = suspects; e; e = e->next) {
1361 blame_origin_incref(porigin);
1362 blame_origin_decref(e->suspect);
1363 e->suspect = porigin;
1365 queue_blames(sb, porigin, suspects);
1369 * We pass blame from the current commit to its parents. We keep saying
1370 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1371 * exonerate ourselves.
1373 static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,
1374 int reverse)
1376 if (!reverse) {
1377 if (revs->first_parent_only &&
1378 commit->parents &&
1379 commit->parents->next) {
1380 free_commit_list(commit->parents->next);
1381 commit->parents->next = NULL;
1383 return commit->parents;
1385 return lookup_decoration(&revs->children, &commit->object);
1388 static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)
1390 struct commit_list *l = first_scapegoat(revs, commit, reverse);
1391 return commit_list_count(l);
1394 /* Distribute collected unsorted blames to the respected sorted lists
1395 * in the various origins.
1397 static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)
1399 blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
1400 compare_blame_suspect);
1401 while (blamed)
1403 struct blame_origin *porigin = blamed->suspect;
1404 struct blame_entry *suspects = NULL;
1405 do {
1406 struct blame_entry *next = blamed->next;
1407 blamed->next = suspects;
1408 suspects = blamed;
1409 blamed = next;
1410 } while (blamed && blamed->suspect == porigin);
1411 suspects = reverse_blame(suspects, NULL);
1412 queue_blames(sb, porigin, suspects);
1416 #define MAXSG 16
1418 static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)
1420 struct rev_info *revs = sb->revs;
1421 int i, pass, num_sg;
1422 struct commit *commit = origin->commit;
1423 struct commit_list *sg;
1424 struct blame_origin *sg_buf[MAXSG];
1425 struct blame_origin *porigin, **sg_origin = sg_buf;
1426 struct blame_entry *toosmall = NULL;
1427 struct blame_entry *blames, **blametail = &blames;
1429 num_sg = num_scapegoats(revs, commit, sb->reverse);
1430 if (!num_sg)
1431 goto finish;
1432 else if (num_sg < ARRAY_SIZE(sg_buf))
1433 memset(sg_buf, 0, sizeof(sg_buf));
1434 else
1435 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1438 * The first pass looks for unrenamed path to optimize for
1439 * common cases, then we look for renames in the second pass.
1441 for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
1442 struct blame_origin *(*find)(struct commit *, struct blame_origin *);
1443 find = pass ? find_rename : find_origin;
1445 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1446 i < num_sg && sg;
1447 sg = sg->next, i++) {
1448 struct commit *p = sg->item;
1449 int j, same;
1451 if (sg_origin[i])
1452 continue;
1453 if (parse_commit(p))
1454 continue;
1455 porigin = find(p, origin);
1456 if (!porigin)
1457 continue;
1458 if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
1459 pass_whole_blame(sb, origin, porigin);
1460 blame_origin_decref(porigin);
1461 goto finish;
1463 for (j = same = 0; j < i; j++)
1464 if (sg_origin[j] &&
1465 !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
1466 same = 1;
1467 break;
1469 if (!same)
1470 sg_origin[i] = porigin;
1471 else
1472 blame_origin_decref(porigin);
1476 sb->num_commits++;
1477 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1478 i < num_sg && sg;
1479 sg = sg->next, i++) {
1480 struct blame_origin *porigin = sg_origin[i];
1481 if (!porigin)
1482 continue;
1483 if (!origin->previous) {
1484 blame_origin_incref(porigin);
1485 origin->previous = porigin;
1487 pass_blame_to_parent(sb, origin, porigin);
1488 if (!origin->suspects)
1489 goto finish;
1493 * Optionally find moves in parents' files.
1495 if (opt & PICKAXE_BLAME_MOVE) {
1496 filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
1497 if (origin->suspects) {
1498 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1499 i < num_sg && sg;
1500 sg = sg->next, i++) {
1501 struct blame_origin *porigin = sg_origin[i];
1502 if (!porigin)
1503 continue;
1504 find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
1505 if (!origin->suspects)
1506 break;
1512 * Optionally find copies from parents' files.
1514 if (opt & PICKAXE_BLAME_COPY) {
1515 if (sb->copy_score > sb->move_score)
1516 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1517 else if (sb->copy_score < sb->move_score) {
1518 origin->suspects = blame_merge(origin->suspects, toosmall);
1519 toosmall = NULL;
1520 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1522 if (!origin->suspects)
1523 goto finish;
1525 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1526 i < num_sg && sg;
1527 sg = sg->next, i++) {
1528 struct blame_origin *porigin = sg_origin[i];
1529 find_copy_in_parent(sb, &blametail, &toosmall,
1530 origin, sg->item, porigin, opt);
1531 if (!origin->suspects)
1532 goto finish;
1536 finish:
1537 *blametail = NULL;
1538 distribute_blame(sb, blames);
1540 * prepend toosmall to origin->suspects
1542 * There is no point in sorting: this ends up on a big
1543 * unsorted list in the caller anyway.
1545 if (toosmall) {
1546 struct blame_entry **tail = &toosmall;
1547 while (*tail)
1548 tail = &(*tail)->next;
1549 *tail = origin->suspects;
1550 origin->suspects = toosmall;
1552 for (i = 0; i < num_sg; i++) {
1553 if (sg_origin[i]) {
1554 drop_origin_blob(sg_origin[i]);
1555 blame_origin_decref(sg_origin[i]);
1558 drop_origin_blob(origin);
1559 if (sg_buf != sg_origin)
1560 free(sg_origin);
1564 * The main loop -- while we have blobs with lines whose true origin
1565 * is still unknown, pick one blob, and allow its lines to pass blames
1566 * to its parents. */
1567 void assign_blame(struct blame_scoreboard *sb, int opt)
1569 struct rev_info *revs = sb->revs;
1570 struct commit *commit = prio_queue_get(&sb->commits);
1572 while (commit) {
1573 struct blame_entry *ent;
1574 struct blame_origin *suspect = get_blame_suspects(commit);
1576 /* find one suspect to break down */
1577 while (suspect && !suspect->suspects)
1578 suspect = suspect->next;
1580 if (!suspect) {
1581 commit = prio_queue_get(&sb->commits);
1582 continue;
1585 assert(commit == suspect->commit);
1588 * We will use this suspect later in the loop,
1589 * so hold onto it in the meantime.
1591 blame_origin_incref(suspect);
1592 parse_commit(commit);
1593 if (sb->reverse ||
1594 (!(commit->object.flags & UNINTERESTING) &&
1595 !(revs->max_age != -1 && commit->date < revs->max_age)))
1596 pass_blame(sb, suspect, opt);
1597 else {
1598 commit->object.flags |= UNINTERESTING;
1599 if (commit->object.parsed)
1600 mark_parents_uninteresting(commit);
1602 /* treat root commit as boundary */
1603 if (!commit->parents && !sb->show_root)
1604 commit->object.flags |= UNINTERESTING;
1606 /* Take responsibility for the remaining entries */
1607 ent = suspect->suspects;
1608 if (ent) {
1609 suspect->guilty = 1;
1610 for (;;) {
1611 struct blame_entry *next = ent->next;
1612 if (sb->found_guilty_entry)
1613 sb->found_guilty_entry(ent, sb->found_guilty_entry_data);
1614 if (next) {
1615 ent = next;
1616 continue;
1618 ent->next = sb->ent;
1619 sb->ent = suspect->suspects;
1620 suspect->suspects = NULL;
1621 break;
1624 blame_origin_decref(suspect);
1626 if (sb->debug) /* sanity */
1627 sanity_check_refcnt(sb);
1631 static const char *get_next_line(const char *start, const char *end)
1633 const char *nl = memchr(start, '\n', end - start);
1634 return nl ? nl + 1 : end;
1638 * To allow quick access to the contents of nth line in the
1639 * final image, prepare an index in the scoreboard.
1641 static int prepare_lines(struct blame_scoreboard *sb)
1643 const char *buf = sb->final_buf;
1644 unsigned long len = sb->final_buf_size;
1645 const char *end = buf + len;
1646 const char *p;
1647 int *lineno;
1648 int num = 0;
1650 for (p = buf; p < end; p = get_next_line(p, end))
1651 num++;
1653 ALLOC_ARRAY(sb->lineno, num + 1);
1654 lineno = sb->lineno;
1656 for (p = buf; p < end; p = get_next_line(p, end))
1657 *lineno++ = p - buf;
1659 *lineno = len;
1661 sb->num_lines = num;
1662 return sb->num_lines;
1665 static struct commit *find_single_final(struct rev_info *revs,
1666 const char **name_p)
1668 int i;
1669 struct commit *found = NULL;
1670 const char *name = NULL;
1672 for (i = 0; i < revs->pending.nr; i++) {
1673 struct object *obj = revs->pending.objects[i].item;
1674 if (obj->flags & UNINTERESTING)
1675 continue;
1676 obj = deref_tag(the_repository, obj, NULL, 0);
1677 if (obj->type != OBJ_COMMIT)
1678 die("Non commit %s?", revs->pending.objects[i].name);
1679 if (found)
1680 die("More than one commit to dig from %s and %s?",
1681 revs->pending.objects[i].name, name);
1682 found = (struct commit *)obj;
1683 name = revs->pending.objects[i].name;
1685 if (name_p)
1686 *name_p = xstrdup_or_null(name);
1687 return found;
1690 static struct commit *dwim_reverse_initial(struct rev_info *revs,
1691 const char **name_p)
1694 * DWIM "git blame --reverse ONE -- PATH" as
1695 * "git blame --reverse ONE..HEAD -- PATH" but only do so
1696 * when it makes sense.
1698 struct object *obj;
1699 struct commit *head_commit;
1700 struct object_id head_oid;
1702 if (revs->pending.nr != 1)
1703 return NULL;
1705 /* Is that sole rev a committish? */
1706 obj = revs->pending.objects[0].item;
1707 obj = deref_tag(the_repository, obj, NULL, 0);
1708 if (obj->type != OBJ_COMMIT)
1709 return NULL;
1711 /* Do we have HEAD? */
1712 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
1713 return NULL;
1714 head_commit = lookup_commit_reference_gently(the_repository,
1715 &head_oid, 1);
1716 if (!head_commit)
1717 return NULL;
1719 /* Turn "ONE" into "ONE..HEAD" then */
1720 obj->flags |= UNINTERESTING;
1721 add_pending_object(revs, &head_commit->object, "HEAD");
1723 if (name_p)
1724 *name_p = revs->pending.objects[0].name;
1725 return (struct commit *)obj;
1728 static struct commit *find_single_initial(struct rev_info *revs,
1729 const char **name_p)
1731 int i;
1732 struct commit *found = NULL;
1733 const char *name = NULL;
1736 * There must be one and only one negative commit, and it must be
1737 * the boundary.
1739 for (i = 0; i < revs->pending.nr; i++) {
1740 struct object *obj = revs->pending.objects[i].item;
1741 if (!(obj->flags & UNINTERESTING))
1742 continue;
1743 obj = deref_tag(the_repository, obj, NULL, 0);
1744 if (obj->type != OBJ_COMMIT)
1745 die("Non commit %s?", revs->pending.objects[i].name);
1746 if (found)
1747 die("More than one commit to dig up from, %s and %s?",
1748 revs->pending.objects[i].name, name);
1749 found = (struct commit *) obj;
1750 name = revs->pending.objects[i].name;
1753 if (!name)
1754 found = dwim_reverse_initial(revs, &name);
1755 if (!name)
1756 die("No commit to dig up from?");
1758 if (name_p)
1759 *name_p = xstrdup(name);
1760 return found;
1763 void init_scoreboard(struct blame_scoreboard *sb)
1765 memset(sb, 0, sizeof(struct blame_scoreboard));
1766 sb->move_score = BLAME_DEFAULT_MOVE_SCORE;
1767 sb->copy_score = BLAME_DEFAULT_COPY_SCORE;
1770 void setup_scoreboard(struct blame_scoreboard *sb, const char *path, struct blame_origin **orig)
1772 const char *final_commit_name = NULL;
1773 struct blame_origin *o;
1774 struct commit *final_commit = NULL;
1775 enum object_type type;
1777 init_blame_suspects(&blame_suspects);
1779 if (sb->reverse && sb->contents_from)
1780 die(_("--contents and --reverse do not blend well."));
1782 if (!sb->reverse) {
1783 sb->final = find_single_final(sb->revs, &final_commit_name);
1784 sb->commits.compare = compare_commits_by_commit_date;
1785 } else {
1786 sb->final = find_single_initial(sb->revs, &final_commit_name);
1787 sb->commits.compare = compare_commits_by_reverse_commit_date;
1790 if (sb->final && sb->contents_from)
1791 die(_("cannot use --contents with final commit object name"));
1793 if (sb->reverse && sb->revs->first_parent_only)
1794 sb->revs->children.name = NULL;
1796 if (!sb->final) {
1798 * "--not A B -- path" without anything positive;
1799 * do not default to HEAD, but use the working tree
1800 * or "--contents".
1802 setup_work_tree();
1803 sb->final = fake_working_tree_commit(&sb->revs->diffopt,
1804 path, sb->contents_from);
1805 add_pending_object(sb->revs, &(sb->final->object), ":");
1808 if (sb->reverse && sb->revs->first_parent_only) {
1809 final_commit = find_single_final(sb->revs, NULL);
1810 if (!final_commit)
1811 die(_("--reverse and --first-parent together require specified latest commit"));
1815 * If we have bottom, this will mark the ancestors of the
1816 * bottom commits we would reach while traversing as
1817 * uninteresting.
1819 if (prepare_revision_walk(sb->revs))
1820 die(_("revision walk setup failed"));
1822 if (sb->reverse && sb->revs->first_parent_only) {
1823 struct commit *c = final_commit;
1825 sb->revs->children.name = "children";
1826 while (c->parents &&
1827 oidcmp(&c->object.oid, &sb->final->object.oid)) {
1828 struct commit_list *l = xcalloc(1, sizeof(*l));
1830 l->item = c;
1831 if (add_decoration(&sb->revs->children,
1832 &c->parents->item->object, l))
1833 BUG("not unique item in first-parent chain");
1834 c = c->parents->item;
1837 if (oidcmp(&c->object.oid, &sb->final->object.oid))
1838 die(_("--reverse --first-parent together require range along first-parent chain"));
1841 if (is_null_oid(&sb->final->object.oid)) {
1842 o = get_blame_suspects(sb->final);
1843 sb->final_buf = xmemdupz(o->file.ptr, o->file.size);
1844 sb->final_buf_size = o->file.size;
1846 else {
1847 o = get_origin(sb->final, path);
1848 if (fill_blob_sha1_and_mode(o))
1849 die(_("no such path %s in %s"), path, final_commit_name);
1851 if (sb->revs->diffopt.flags.allow_textconv &&
1852 textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
1853 &sb->final_buf_size))
1855 else
1856 sb->final_buf = read_object_file(&o->blob_oid, &type,
1857 &sb->final_buf_size);
1859 if (!sb->final_buf)
1860 die(_("cannot read blob %s for path %s"),
1861 oid_to_hex(&o->blob_oid),
1862 path);
1864 sb->num_read_blob++;
1865 prepare_lines(sb);
1867 if (orig)
1868 *orig = o;
1870 free((char *)final_commit_name);
1875 struct blame_entry *blame_entry_prepend(struct blame_entry *head,
1876 long start, long end,
1877 struct blame_origin *o)
1879 struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
1880 new_head->lno = start;
1881 new_head->num_lines = end - start;
1882 new_head->suspect = o;
1883 new_head->s_lno = start;
1884 new_head->next = head;
1885 blame_origin_incref(o);
1886 return new_head;