Merge branch 'sg/test-bash-version-fix'
[git.git] / blame.c
blobd84c937780801f51b8eb98b7e367c8017701ba5c
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 repository *r,
94 struct commit *work_tree, const char *path)
96 struct commit_list *parents;
97 int pos;
99 for (parents = work_tree->parents; parents; parents = parents->next) {
100 const struct object_id *commit_oid = &parents->item->object.oid;
101 struct object_id blob_oid;
102 unsigned mode;
104 if (!get_tree_entry(commit_oid, path, &blob_oid, &mode) &&
105 oid_object_info(r, &blob_oid, NULL) == OBJ_BLOB)
106 return;
109 pos = index_name_pos(r->index, path, strlen(path));
110 if (pos >= 0)
111 ; /* path is in the index */
112 else if (-1 - pos < r->index->cache_nr &&
113 !strcmp(r->index->cache[-1 - pos]->name, path))
114 ; /* path is in the index, unmerged */
115 else
116 die("no such path '%s' in HEAD", path);
119 static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
121 struct commit *parent;
123 parent = lookup_commit_reference(the_repository, oid);
124 if (!parent)
125 die("no such commit %s", oid_to_hex(oid));
126 return &commit_list_insert(parent, tail)->next;
129 static void append_merge_parents(struct commit_list **tail)
131 int merge_head;
132 struct strbuf line = STRBUF_INIT;
134 merge_head = open(git_path_merge_head(the_repository), O_RDONLY);
135 if (merge_head < 0) {
136 if (errno == ENOENT)
137 return;
138 die("cannot open '%s' for reading",
139 git_path_merge_head(the_repository));
142 while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
143 struct object_id oid;
144 if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
145 die("unknown line in '%s': %s",
146 git_path_merge_head(the_repository), line.buf);
147 tail = append_parent(tail, &oid);
149 close(merge_head);
150 strbuf_release(&line);
154 * This isn't as simple as passing sb->buf and sb->len, because we
155 * want to transfer ownership of the buffer to the commit (so we
156 * must use detach).
158 static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb)
160 size_t len;
161 void *buf = strbuf_detach(sb, &len);
162 set_commit_buffer(the_repository, c, buf, len);
166 * Prepare a dummy commit that represents the work tree (or staged) item.
167 * Note that annotating work tree item never works in the reverse.
169 static struct commit *fake_working_tree_commit(struct repository *r,
170 struct diff_options *opt,
171 const char *path,
172 const char *contents_from)
174 struct commit *commit;
175 struct blame_origin *origin;
176 struct commit_list **parent_tail, *parent;
177 struct object_id head_oid;
178 struct strbuf buf = STRBUF_INIT;
179 const char *ident;
180 time_t now;
181 int len;
182 struct cache_entry *ce;
183 unsigned mode;
184 struct strbuf msg = STRBUF_INIT;
186 read_index(r->index);
187 time(&now);
188 commit = alloc_commit_node(the_repository);
189 commit->object.parsed = 1;
190 commit->date = now;
191 parent_tail = &commit->parents;
193 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
194 die("no such ref: HEAD");
196 parent_tail = append_parent(parent_tail, &head_oid);
197 append_merge_parents(parent_tail);
198 verify_working_tree_path(r, commit, path);
200 origin = make_origin(commit, path);
202 ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
203 strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
204 for (parent = commit->parents; parent; parent = parent->next)
205 strbuf_addf(&msg, "parent %s\n",
206 oid_to_hex(&parent->item->object.oid));
207 strbuf_addf(&msg,
208 "author %s\n"
209 "committer %s\n\n"
210 "Version of %s from %s\n",
211 ident, ident, path,
212 (!contents_from ? path :
213 (!strcmp(contents_from, "-") ? "standard input" : contents_from)));
214 set_commit_buffer_from_strbuf(commit, &msg);
216 if (!contents_from || strcmp("-", contents_from)) {
217 struct stat st;
218 const char *read_from;
219 char *buf_ptr;
220 unsigned long buf_len;
222 if (contents_from) {
223 if (stat(contents_from, &st) < 0)
224 die_errno("Cannot stat '%s'", contents_from);
225 read_from = contents_from;
227 else {
228 if (lstat(path, &st) < 0)
229 die_errno("Cannot lstat '%s'", path);
230 read_from = path;
232 mode = canon_mode(st.st_mode);
234 switch (st.st_mode & S_IFMT) {
235 case S_IFREG:
236 if (opt->flags.allow_textconv &&
237 textconv_object(r, read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
238 strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
239 else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
240 die_errno("cannot open or read '%s'", read_from);
241 break;
242 case S_IFLNK:
243 if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
244 die_errno("cannot readlink '%s'", read_from);
245 break;
246 default:
247 die("unsupported file type %s", read_from);
250 else {
251 /* Reading from stdin */
252 mode = 0;
253 if (strbuf_read(&buf, 0, 0) < 0)
254 die_errno("failed to read from stdin");
256 convert_to_git(r->index, path, buf.buf, buf.len, &buf, 0);
257 origin->file.ptr = buf.buf;
258 origin->file.size = buf.len;
259 pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid);
262 * Read the current index, replace the path entry with
263 * origin->blob_sha1 without mucking with its mode or type
264 * bits; we are not going to write this index out -- we just
265 * want to run "diff-index --cached".
267 discard_index(r->index);
268 read_index(r->index);
270 len = strlen(path);
271 if (!mode) {
272 int pos = index_name_pos(r->index, path, len);
273 if (0 <= pos)
274 mode = r->index->cache[pos]->ce_mode;
275 else
276 /* Let's not bother reading from HEAD tree */
277 mode = S_IFREG | 0644;
279 ce = make_empty_cache_entry(r->index, len);
280 oidcpy(&ce->oid, &origin->blob_oid);
281 memcpy(ce->name, path, len);
282 ce->ce_flags = create_ce_flags(0);
283 ce->ce_namelen = len;
284 ce->ce_mode = create_ce_mode(mode);
285 add_index_entry(r->index, ce,
286 ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
288 cache_tree_invalidate_path(r->index, path);
290 return commit;
295 static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
296 xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts)
298 xpparam_t xpp = {0};
299 xdemitconf_t xecfg = {0};
300 xdemitcb_t ecb = {NULL};
302 xpp.flags = xdl_opts;
303 xecfg.hunk_func = hunk_func;
304 ecb.priv = cb_data;
305 return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
309 * Given an origin, prepare mmfile_t structure to be used by the
310 * diff machinery
312 static void fill_origin_blob(struct diff_options *opt,
313 struct blame_origin *o, mmfile_t *file, int *num_read_blob)
315 if (!o->file.ptr) {
316 enum object_type type;
317 unsigned long file_size;
319 (*num_read_blob)++;
320 if (opt->flags.allow_textconv &&
321 textconv_object(opt->repo, o->path, o->mode,
322 &o->blob_oid, 1, &file->ptr, &file_size))
324 else
325 file->ptr = read_object_file(&o->blob_oid, &type,
326 &file_size);
327 file->size = file_size;
329 if (!file->ptr)
330 die("Cannot read blob %s for path %s",
331 oid_to_hex(&o->blob_oid),
332 o->path);
333 o->file = *file;
335 else
336 *file = o->file;
339 static void drop_origin_blob(struct blame_origin *o)
341 FREE_AND_NULL(o->file.ptr);
345 * Any merge of blames happens on lists of blames that arrived via
346 * different parents in a single suspect. In this case, we want to
347 * sort according to the suspect line numbers as opposed to the final
348 * image line numbers. The function body is somewhat longish because
349 * it avoids unnecessary writes.
352 static struct blame_entry *blame_merge(struct blame_entry *list1,
353 struct blame_entry *list2)
355 struct blame_entry *p1 = list1, *p2 = list2,
356 **tail = &list1;
358 if (!p1)
359 return p2;
360 if (!p2)
361 return p1;
363 if (p1->s_lno <= p2->s_lno) {
364 do {
365 tail = &p1->next;
366 if ((p1 = *tail) == NULL) {
367 *tail = p2;
368 return list1;
370 } while (p1->s_lno <= p2->s_lno);
372 for (;;) {
373 *tail = p2;
374 do {
375 tail = &p2->next;
376 if ((p2 = *tail) == NULL) {
377 *tail = p1;
378 return list1;
380 } while (p1->s_lno > p2->s_lno);
381 *tail = p1;
382 do {
383 tail = &p1->next;
384 if ((p1 = *tail) == NULL) {
385 *tail = p2;
386 return list1;
388 } while (p1->s_lno <= p2->s_lno);
392 static void *get_next_blame(const void *p)
394 return ((struct blame_entry *)p)->next;
397 static void set_next_blame(void *p1, void *p2)
399 ((struct blame_entry *)p1)->next = p2;
403 * Final image line numbers are all different, so we don't need a
404 * three-way comparison here.
407 static int compare_blame_final(const void *p1, const void *p2)
409 return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
410 ? 1 : -1;
413 static int compare_blame_suspect(const void *p1, const void *p2)
415 const struct blame_entry *s1 = p1, *s2 = p2;
417 * to allow for collating suspects, we sort according to the
418 * respective pointer value as the primary sorting criterion.
419 * The actual relation is pretty unimportant as long as it
420 * establishes a total order. Comparing as integers gives us
421 * that.
423 if (s1->suspect != s2->suspect)
424 return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
425 if (s1->s_lno == s2->s_lno)
426 return 0;
427 return s1->s_lno > s2->s_lno ? 1 : -1;
430 void blame_sort_final(struct blame_scoreboard *sb)
432 sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
433 compare_blame_final);
436 static int compare_commits_by_reverse_commit_date(const void *a,
437 const void *b,
438 void *c)
440 return -compare_commits_by_commit_date(a, b, c);
444 * For debugging -- origin is refcounted, and this asserts that
445 * we do not underflow.
447 static void sanity_check_refcnt(struct blame_scoreboard *sb)
449 int baa = 0;
450 struct blame_entry *ent;
452 for (ent = sb->ent; ent; ent = ent->next) {
453 /* Nobody should have zero or negative refcnt */
454 if (ent->suspect->refcnt <= 0) {
455 fprintf(stderr, "%s in %s has negative refcnt %d\n",
456 ent->suspect->path,
457 oid_to_hex(&ent->suspect->commit->object.oid),
458 ent->suspect->refcnt);
459 baa = 1;
462 if (baa)
463 sb->on_sanity_fail(sb, baa);
467 * If two blame entries that are next to each other came from
468 * contiguous lines in the same origin (i.e. <commit, path> pair),
469 * merge them together.
471 void blame_coalesce(struct blame_scoreboard *sb)
473 struct blame_entry *ent, *next;
475 for (ent = sb->ent; ent && (next = ent->next); ent = next) {
476 if (ent->suspect == next->suspect &&
477 ent->s_lno + ent->num_lines == next->s_lno) {
478 ent->num_lines += next->num_lines;
479 ent->next = next->next;
480 blame_origin_decref(next->suspect);
481 free(next);
482 ent->score = 0;
483 next = ent; /* again */
487 if (sb->debug) /* sanity */
488 sanity_check_refcnt(sb);
492 * Merge the given sorted list of blames into a preexisting origin.
493 * If there were no previous blames to that commit, it is entered into
494 * the commit priority queue of the score board.
497 static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin,
498 struct blame_entry *sorted)
500 if (porigin->suspects)
501 porigin->suspects = blame_merge(porigin->suspects, sorted);
502 else {
503 struct blame_origin *o;
504 for (o = get_blame_suspects(porigin->commit); o; o = o->next) {
505 if (o->suspects) {
506 porigin->suspects = sorted;
507 return;
510 porigin->suspects = sorted;
511 prio_queue_put(&sb->commits, porigin->commit);
516 * Fill the blob_sha1 field of an origin if it hasn't, so that later
517 * call to fill_origin_blob() can use it to locate the data. blob_sha1
518 * for an origin is also used to pass the blame for the entire file to
519 * the parent to detect the case where a child's blob is identical to
520 * that of its parent's.
522 * This also fills origin->mode for corresponding tree path.
524 static int fill_blob_sha1_and_mode(struct repository *r,
525 struct blame_origin *origin)
527 if (!is_null_oid(&origin->blob_oid))
528 return 0;
529 if (get_tree_entry(&origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode))
530 goto error_out;
531 if (oid_object_info(r, &origin->blob_oid, NULL) != OBJ_BLOB)
532 goto error_out;
533 return 0;
534 error_out:
535 oidclr(&origin->blob_oid);
536 origin->mode = S_IFINVALID;
537 return -1;
541 * We have an origin -- check if the same path exists in the
542 * parent and return an origin structure to represent it.
544 static struct blame_origin *find_origin(struct repository *r,
545 struct commit *parent,
546 struct blame_origin *origin)
548 struct blame_origin *porigin;
549 struct diff_options diff_opts;
550 const char *paths[2];
552 /* First check any existing origins */
553 for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next)
554 if (!strcmp(porigin->path, origin->path)) {
556 * The same path between origin and its parent
557 * without renaming -- the most common case.
559 return blame_origin_incref (porigin);
562 /* See if the origin->path is different between parent
563 * and origin first. Most of the time they are the
564 * same and diff-tree is fairly efficient about this.
566 repo_diff_setup(r, &diff_opts);
567 diff_opts.flags.recursive = 1;
568 diff_opts.detect_rename = 0;
569 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
570 paths[0] = origin->path;
571 paths[1] = NULL;
573 parse_pathspec(&diff_opts.pathspec,
574 PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
575 PATHSPEC_LITERAL_PATH, "", paths);
576 diff_setup_done(&diff_opts);
578 if (is_null_oid(&origin->commit->object.oid))
579 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
580 else
581 diff_tree_oid(get_commit_tree_oid(parent),
582 get_commit_tree_oid(origin->commit),
583 "", &diff_opts);
584 diffcore_std(&diff_opts);
586 if (!diff_queued_diff.nr) {
587 /* The path is the same as parent */
588 porigin = get_origin(parent, origin->path);
589 oidcpy(&porigin->blob_oid, &origin->blob_oid);
590 porigin->mode = origin->mode;
591 } else {
593 * Since origin->path is a pathspec, if the parent
594 * commit had it as a directory, we will see a whole
595 * bunch of deletion of files in the directory that we
596 * do not care about.
598 int i;
599 struct diff_filepair *p = NULL;
600 for (i = 0; i < diff_queued_diff.nr; i++) {
601 const char *name;
602 p = diff_queued_diff.queue[i];
603 name = p->one->path ? p->one->path : p->two->path;
604 if (!strcmp(name, origin->path))
605 break;
607 if (!p)
608 die("internal error in blame::find_origin");
609 switch (p->status) {
610 default:
611 die("internal error in blame::find_origin (%c)",
612 p->status);
613 case 'M':
614 porigin = get_origin(parent, origin->path);
615 oidcpy(&porigin->blob_oid, &p->one->oid);
616 porigin->mode = p->one->mode;
617 break;
618 case 'A':
619 case 'T':
620 /* Did not exist in parent, or type changed */
621 break;
624 diff_flush(&diff_opts);
625 clear_pathspec(&diff_opts.pathspec);
626 return porigin;
630 * We have an origin -- find the path that corresponds to it in its
631 * parent and return an origin structure to represent it.
633 static struct blame_origin *find_rename(struct repository *r,
634 struct commit *parent,
635 struct blame_origin *origin)
637 struct blame_origin *porigin = NULL;
638 struct diff_options diff_opts;
639 int i;
641 repo_diff_setup(r, &diff_opts);
642 diff_opts.flags.recursive = 1;
643 diff_opts.detect_rename = DIFF_DETECT_RENAME;
644 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
645 diff_opts.single_follow = origin->path;
646 diff_setup_done(&diff_opts);
648 if (is_null_oid(&origin->commit->object.oid))
649 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
650 else
651 diff_tree_oid(get_commit_tree_oid(parent),
652 get_commit_tree_oid(origin->commit),
653 "", &diff_opts);
654 diffcore_std(&diff_opts);
656 for (i = 0; i < diff_queued_diff.nr; i++) {
657 struct diff_filepair *p = diff_queued_diff.queue[i];
658 if ((p->status == 'R' || p->status == 'C') &&
659 !strcmp(p->two->path, origin->path)) {
660 porigin = get_origin(parent, p->one->path);
661 oidcpy(&porigin->blob_oid, &p->one->oid);
662 porigin->mode = p->one->mode;
663 break;
666 diff_flush(&diff_opts);
667 clear_pathspec(&diff_opts.pathspec);
668 return porigin;
672 * Append a new blame entry to a given output queue.
674 static void add_blame_entry(struct blame_entry ***queue,
675 const struct blame_entry *src)
677 struct blame_entry *e = xmalloc(sizeof(*e));
678 memcpy(e, src, sizeof(*e));
679 blame_origin_incref(e->suspect);
681 e->next = **queue;
682 **queue = e;
683 *queue = &e->next;
687 * src typically is on-stack; we want to copy the information in it to
688 * a malloced blame_entry that gets added to the given queue. The
689 * origin of dst loses a refcnt.
691 static void dup_entry(struct blame_entry ***queue,
692 struct blame_entry *dst, struct blame_entry *src)
694 blame_origin_incref(src->suspect);
695 blame_origin_decref(dst->suspect);
696 memcpy(dst, src, sizeof(*src));
697 dst->next = **queue;
698 **queue = dst;
699 *queue = &dst->next;
702 const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
704 return sb->final_buf + sb->lineno[lno];
708 * It is known that lines between tlno to same came from parent, and e
709 * has an overlap with that range. it also is known that parent's
710 * line plno corresponds to e's line tlno.
712 * <---- e ----->
713 * <------>
714 * <------------>
715 * <------------>
716 * <------------------>
718 * Split e into potentially three parts; before this chunk, the chunk
719 * to be blamed for the parent, and after that portion.
721 static void split_overlap(struct blame_entry *split,
722 struct blame_entry *e,
723 int tlno, int plno, int same,
724 struct blame_origin *parent)
726 int chunk_end_lno;
727 memset(split, 0, sizeof(struct blame_entry [3]));
729 if (e->s_lno < tlno) {
730 /* there is a pre-chunk part not blamed on parent */
731 split[0].suspect = blame_origin_incref(e->suspect);
732 split[0].lno = e->lno;
733 split[0].s_lno = e->s_lno;
734 split[0].num_lines = tlno - e->s_lno;
735 split[1].lno = e->lno + tlno - e->s_lno;
736 split[1].s_lno = plno;
738 else {
739 split[1].lno = e->lno;
740 split[1].s_lno = plno + (e->s_lno - tlno);
743 if (same < e->s_lno + e->num_lines) {
744 /* there is a post-chunk part not blamed on parent */
745 split[2].suspect = blame_origin_incref(e->suspect);
746 split[2].lno = e->lno + (same - e->s_lno);
747 split[2].s_lno = e->s_lno + (same - e->s_lno);
748 split[2].num_lines = e->s_lno + e->num_lines - same;
749 chunk_end_lno = split[2].lno;
751 else
752 chunk_end_lno = e->lno + e->num_lines;
753 split[1].num_lines = chunk_end_lno - split[1].lno;
756 * if it turns out there is nothing to blame the parent for,
757 * forget about the splitting. !split[1].suspect signals this.
759 if (split[1].num_lines < 1)
760 return;
761 split[1].suspect = blame_origin_incref(parent);
765 * split_overlap() divided an existing blame e into up to three parts
766 * in split. Any assigned blame is moved to queue to
767 * reflect the split.
769 static void split_blame(struct blame_entry ***blamed,
770 struct blame_entry ***unblamed,
771 struct blame_entry *split,
772 struct blame_entry *e)
774 if (split[0].suspect && split[2].suspect) {
775 /* The first part (reuse storage for the existing entry e) */
776 dup_entry(unblamed, e, &split[0]);
778 /* The last part -- me */
779 add_blame_entry(unblamed, &split[2]);
781 /* ... and the middle part -- parent */
782 add_blame_entry(blamed, &split[1]);
784 else if (!split[0].suspect && !split[2].suspect)
786 * The parent covers the entire area; reuse storage for
787 * e and replace it with the parent.
789 dup_entry(blamed, e, &split[1]);
790 else if (split[0].suspect) {
791 /* me and then parent */
792 dup_entry(unblamed, e, &split[0]);
793 add_blame_entry(blamed, &split[1]);
795 else {
796 /* parent and then me */
797 dup_entry(blamed, e, &split[1]);
798 add_blame_entry(unblamed, &split[2]);
803 * After splitting the blame, the origins used by the
804 * on-stack blame_entry should lose one refcnt each.
806 static void decref_split(struct blame_entry *split)
808 int i;
810 for (i = 0; i < 3; i++)
811 blame_origin_decref(split[i].suspect);
815 * reverse_blame reverses the list given in head, appending tail.
816 * That allows us to build lists in reverse order, then reverse them
817 * afterwards. This can be faster than building the list in proper
818 * order right away. The reason is that building in proper order
819 * requires writing a link in the _previous_ element, while building
820 * in reverse order just requires placing the list head into the
821 * _current_ element.
824 static struct blame_entry *reverse_blame(struct blame_entry *head,
825 struct blame_entry *tail)
827 while (head) {
828 struct blame_entry *next = head->next;
829 head->next = tail;
830 tail = head;
831 head = next;
833 return tail;
837 * Process one hunk from the patch between the current suspect for
838 * blame_entry e and its parent. This first blames any unfinished
839 * entries before the chunk (which is where target and parent start
840 * differing) on the parent, and then splits blame entries at the
841 * start and at the end of the difference region. Since use of -M and
842 * -C options may lead to overlapping/duplicate source line number
843 * ranges, all we can rely on from sorting/merging is the order of the
844 * first suspect line number.
846 static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
847 int tlno, int offset, int same,
848 struct blame_origin *parent)
850 struct blame_entry *e = **srcq;
851 struct blame_entry *samep = NULL, *diffp = NULL;
853 while (e && e->s_lno < tlno) {
854 struct blame_entry *next = e->next;
856 * current record starts before differing portion. If
857 * it reaches into it, we need to split it up and
858 * examine the second part separately.
860 if (e->s_lno + e->num_lines > tlno) {
861 /* Move second half to a new record */
862 int len = tlno - e->s_lno;
863 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
864 n->suspect = e->suspect;
865 n->lno = e->lno + len;
866 n->s_lno = e->s_lno + len;
867 n->num_lines = e->num_lines - len;
868 e->num_lines = len;
869 e->score = 0;
870 /* Push new record to diffp */
871 n->next = diffp;
872 diffp = n;
873 } else
874 blame_origin_decref(e->suspect);
875 /* Pass blame for everything before the differing
876 * chunk to the parent */
877 e->suspect = blame_origin_incref(parent);
878 e->s_lno += offset;
879 e->next = samep;
880 samep = e;
881 e = next;
884 * As we don't know how much of a common stretch after this
885 * diff will occur, the currently blamed parts are all that we
886 * can assign to the parent for now.
889 if (samep) {
890 **dstq = reverse_blame(samep, **dstq);
891 *dstq = &samep->next;
894 * Prepend the split off portions: everything after e starts
895 * after the blameable portion.
897 e = reverse_blame(diffp, e);
900 * Now retain records on the target while parts are different
901 * from the parent.
903 samep = NULL;
904 diffp = NULL;
905 while (e && e->s_lno < same) {
906 struct blame_entry *next = e->next;
909 * If current record extends into sameness, need to split.
911 if (e->s_lno + e->num_lines > same) {
913 * Move second half to a new record to be
914 * processed by later chunks
916 int len = same - e->s_lno;
917 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
918 n->suspect = blame_origin_incref(e->suspect);
919 n->lno = e->lno + len;
920 n->s_lno = e->s_lno + len;
921 n->num_lines = e->num_lines - len;
922 e->num_lines = len;
923 e->score = 0;
924 /* Push new record to samep */
925 n->next = samep;
926 samep = n;
928 e->next = diffp;
929 diffp = e;
930 e = next;
932 **srcq = reverse_blame(diffp, reverse_blame(samep, e));
933 /* Move across elements that are in the unblamable portion */
934 if (diffp)
935 *srcq = &diffp->next;
938 struct blame_chunk_cb_data {
939 struct blame_origin *parent;
940 long offset;
941 struct blame_entry **dstq;
942 struct blame_entry **srcq;
945 /* diff chunks are from parent to target */
946 static int blame_chunk_cb(long start_a, long count_a,
947 long start_b, long count_b, void *data)
949 struct blame_chunk_cb_data *d = data;
950 if (start_a - start_b != d->offset)
951 die("internal error in blame::blame_chunk_cb");
952 blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
953 start_b + count_b, d->parent);
954 d->offset = start_a + count_a - (start_b + count_b);
955 return 0;
959 * We are looking at the origin 'target' and aiming to pass blame
960 * for the lines it is suspected to its parent. Run diff to find
961 * which lines came from parent and pass blame for them.
963 static void pass_blame_to_parent(struct blame_scoreboard *sb,
964 struct blame_origin *target,
965 struct blame_origin *parent)
967 mmfile_t file_p, file_o;
968 struct blame_chunk_cb_data d;
969 struct blame_entry *newdest = NULL;
971 if (!target->suspects)
972 return; /* nothing remains for this target */
974 d.parent = parent;
975 d.offset = 0;
976 d.dstq = &newdest; d.srcq = &target->suspects;
978 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
979 fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
980 sb->num_get_patch++;
982 if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
983 die("unable to generate diff (%s -> %s)",
984 oid_to_hex(&parent->commit->object.oid),
985 oid_to_hex(&target->commit->object.oid));
986 /* The rest are the same as the parent */
987 blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
988 *d.dstq = NULL;
989 queue_blames(sb, parent, newdest);
991 return;
995 * The lines in blame_entry after splitting blames many times can become
996 * very small and trivial, and at some point it becomes pointless to
997 * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any
998 * ordinary C program, and it is not worth to say it was copied from
999 * totally unrelated file in the parent.
1001 * Compute how trivial the lines in the blame_entry are.
1003 unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
1005 unsigned score;
1006 const char *cp, *ep;
1008 if (e->score)
1009 return e->score;
1011 score = 1;
1012 cp = blame_nth_line(sb, e->lno);
1013 ep = blame_nth_line(sb, e->lno + e->num_lines);
1014 while (cp < ep) {
1015 unsigned ch = *((unsigned char *)cp);
1016 if (isalnum(ch))
1017 score++;
1018 cp++;
1020 e->score = score;
1021 return score;
1025 * best_so_far[] and potential[] are both a split of an existing blame_entry
1026 * that passes blame to the parent. Maintain best_so_far the best split so
1027 * far, by comparing potential and best_so_far and copying potential into
1028 * bst_so_far as needed.
1030 static void copy_split_if_better(struct blame_scoreboard *sb,
1031 struct blame_entry *best_so_far,
1032 struct blame_entry *potential)
1034 int i;
1036 if (!potential[1].suspect)
1037 return;
1038 if (best_so_far[1].suspect) {
1039 if (blame_entry_score(sb, &potential[1]) <
1040 blame_entry_score(sb, &best_so_far[1]))
1041 return;
1044 for (i = 0; i < 3; i++)
1045 blame_origin_incref(potential[i].suspect);
1046 decref_split(best_so_far);
1047 memcpy(best_so_far, potential, sizeof(struct blame_entry[3]));
1051 * We are looking at a part of the final image represented by
1052 * ent (tlno and same are offset by ent->s_lno).
1053 * tlno is where we are looking at in the final image.
1054 * up to (but not including) same match preimage.
1055 * plno is where we are looking at in the preimage.
1057 * <-------------- final image ---------------------->
1058 * <------ent------>
1059 * ^tlno ^same
1060 * <---------preimage----->
1061 * ^plno
1063 * All line numbers are 0-based.
1065 static void handle_split(struct blame_scoreboard *sb,
1066 struct blame_entry *ent,
1067 int tlno, int plno, int same,
1068 struct blame_origin *parent,
1069 struct blame_entry *split)
1071 if (ent->num_lines <= tlno)
1072 return;
1073 if (tlno < same) {
1074 struct blame_entry potential[3];
1075 tlno += ent->s_lno;
1076 same += ent->s_lno;
1077 split_overlap(potential, ent, tlno, plno, same, parent);
1078 copy_split_if_better(sb, split, potential);
1079 decref_split(potential);
1083 struct handle_split_cb_data {
1084 struct blame_scoreboard *sb;
1085 struct blame_entry *ent;
1086 struct blame_origin *parent;
1087 struct blame_entry *split;
1088 long plno;
1089 long tlno;
1092 static int handle_split_cb(long start_a, long count_a,
1093 long start_b, long count_b, void *data)
1095 struct handle_split_cb_data *d = data;
1096 handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
1097 d->split);
1098 d->plno = start_a + count_a;
1099 d->tlno = start_b + count_b;
1100 return 0;
1104 * Find the lines from parent that are the same as ent so that
1105 * we can pass blames to it. file_p has the blob contents for
1106 * the parent.
1108 static void find_copy_in_blob(struct blame_scoreboard *sb,
1109 struct blame_entry *ent,
1110 struct blame_origin *parent,
1111 struct blame_entry *split,
1112 mmfile_t *file_p)
1114 const char *cp;
1115 mmfile_t file_o;
1116 struct handle_split_cb_data d;
1118 memset(&d, 0, sizeof(d));
1119 d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
1121 * Prepare mmfile that contains only the lines in ent.
1123 cp = blame_nth_line(sb, ent->lno);
1124 file_o.ptr = (char *) cp;
1125 file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
1128 * file_o is a part of final image we are annotating.
1129 * file_p partially may match that image.
1131 memset(split, 0, sizeof(struct blame_entry [3]));
1132 if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
1133 die("unable to generate diff (%s)",
1134 oid_to_hex(&parent->commit->object.oid));
1135 /* remainder, if any, all match the preimage */
1136 handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
1139 /* Move all blame entries from list *source that have a score smaller
1140 * than score_min to the front of list *small.
1141 * Returns a pointer to the link pointing to the old head of the small list.
1144 static struct blame_entry **filter_small(struct blame_scoreboard *sb,
1145 struct blame_entry **small,
1146 struct blame_entry **source,
1147 unsigned score_min)
1149 struct blame_entry *p = *source;
1150 struct blame_entry *oldsmall = *small;
1151 while (p) {
1152 if (blame_entry_score(sb, p) <= score_min) {
1153 *small = p;
1154 small = &p->next;
1155 p = *small;
1156 } else {
1157 *source = p;
1158 source = &p->next;
1159 p = *source;
1162 *small = oldsmall;
1163 *source = NULL;
1164 return small;
1168 * See if lines currently target is suspected for can be attributed to
1169 * parent.
1171 static void find_move_in_parent(struct blame_scoreboard *sb,
1172 struct blame_entry ***blamed,
1173 struct blame_entry **toosmall,
1174 struct blame_origin *target,
1175 struct blame_origin *parent)
1177 struct blame_entry *e, split[3];
1178 struct blame_entry *unblamed = target->suspects;
1179 struct blame_entry *leftover = NULL;
1180 mmfile_t file_p;
1182 if (!unblamed)
1183 return; /* nothing remains for this target */
1185 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
1186 if (!file_p.ptr)
1187 return;
1189 /* At each iteration, unblamed has a NULL-terminated list of
1190 * entries that have not yet been tested for blame. leftover
1191 * contains the reversed list of entries that have been tested
1192 * without being assignable to the parent.
1194 do {
1195 struct blame_entry **unblamedtail = &unblamed;
1196 struct blame_entry *next;
1197 for (e = unblamed; e; e = next) {
1198 next = e->next;
1199 find_copy_in_blob(sb, e, parent, split, &file_p);
1200 if (split[1].suspect &&
1201 sb->move_score < blame_entry_score(sb, &split[1])) {
1202 split_blame(blamed, &unblamedtail, split, e);
1203 } else {
1204 e->next = leftover;
1205 leftover = e;
1207 decref_split(split);
1209 *unblamedtail = NULL;
1210 toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);
1211 } while (unblamed);
1212 target->suspects = reverse_blame(leftover, NULL);
1215 struct blame_list {
1216 struct blame_entry *ent;
1217 struct blame_entry split[3];
1221 * Count the number of entries the target is suspected for,
1222 * and prepare a list of entry and the best split.
1224 static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
1225 int *num_ents_p)
1227 struct blame_entry *e;
1228 int num_ents, i;
1229 struct blame_list *blame_list = NULL;
1231 for (e = unblamed, num_ents = 0; e; e = e->next)
1232 num_ents++;
1233 if (num_ents) {
1234 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1235 for (e = unblamed, i = 0; e; e = e->next)
1236 blame_list[i++].ent = e;
1238 *num_ents_p = num_ents;
1239 return blame_list;
1243 * For lines target is suspected for, see if we can find code movement
1244 * across file boundary from the parent commit. porigin is the path
1245 * in the parent we already tried.
1247 static void find_copy_in_parent(struct blame_scoreboard *sb,
1248 struct blame_entry ***blamed,
1249 struct blame_entry **toosmall,
1250 struct blame_origin *target,
1251 struct commit *parent,
1252 struct blame_origin *porigin,
1253 int opt)
1255 struct diff_options diff_opts;
1256 int i, j;
1257 struct blame_list *blame_list;
1258 int num_ents;
1259 struct blame_entry *unblamed = target->suspects;
1260 struct blame_entry *leftover = NULL;
1262 if (!unblamed)
1263 return; /* nothing remains for this target */
1265 repo_diff_setup(sb->repo, &diff_opts);
1266 diff_opts.flags.recursive = 1;
1267 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1269 diff_setup_done(&diff_opts);
1271 /* Try "find copies harder" on new path if requested;
1272 * we do not want to use diffcore_rename() actually to
1273 * match things up; find_copies_harder is set only to
1274 * force diff_tree_oid() to feed all filepairs to diff_queue,
1275 * and this code needs to be after diff_setup_done(), which
1276 * usually makes find-copies-harder imply copy detection.
1278 if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1279 || ((opt & PICKAXE_BLAME_COPY_HARDER)
1280 && (!porigin || strcmp(target->path, porigin->path))))
1281 diff_opts.flags.find_copies_harder = 1;
1283 if (is_null_oid(&target->commit->object.oid))
1284 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
1285 else
1286 diff_tree_oid(get_commit_tree_oid(parent),
1287 get_commit_tree_oid(target->commit),
1288 "", &diff_opts);
1290 if (!diff_opts.flags.find_copies_harder)
1291 diffcore_std(&diff_opts);
1293 do {
1294 struct blame_entry **unblamedtail = &unblamed;
1295 blame_list = setup_blame_list(unblamed, &num_ents);
1297 for (i = 0; i < diff_queued_diff.nr; i++) {
1298 struct diff_filepair *p = diff_queued_diff.queue[i];
1299 struct blame_origin *norigin;
1300 mmfile_t file_p;
1301 struct blame_entry potential[3];
1303 if (!DIFF_FILE_VALID(p->one))
1304 continue; /* does not exist in parent */
1305 if (S_ISGITLINK(p->one->mode))
1306 continue; /* ignore git links */
1307 if (porigin && !strcmp(p->one->path, porigin->path))
1308 /* find_move already dealt with this path */
1309 continue;
1311 norigin = get_origin(parent, p->one->path);
1312 oidcpy(&norigin->blob_oid, &p->one->oid);
1313 norigin->mode = p->one->mode;
1314 fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
1315 if (!file_p.ptr)
1316 continue;
1318 for (j = 0; j < num_ents; j++) {
1319 find_copy_in_blob(sb, blame_list[j].ent,
1320 norigin, potential, &file_p);
1321 copy_split_if_better(sb, blame_list[j].split,
1322 potential);
1323 decref_split(potential);
1325 blame_origin_decref(norigin);
1328 for (j = 0; j < num_ents; j++) {
1329 struct blame_entry *split = blame_list[j].split;
1330 if (split[1].suspect &&
1331 sb->copy_score < blame_entry_score(sb, &split[1])) {
1332 split_blame(blamed, &unblamedtail, split,
1333 blame_list[j].ent);
1334 } else {
1335 blame_list[j].ent->next = leftover;
1336 leftover = blame_list[j].ent;
1338 decref_split(split);
1340 free(blame_list);
1341 *unblamedtail = NULL;
1342 toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);
1343 } while (unblamed);
1344 target->suspects = reverse_blame(leftover, NULL);
1345 diff_flush(&diff_opts);
1346 clear_pathspec(&diff_opts.pathspec);
1350 * The blobs of origin and porigin exactly match, so everything
1351 * origin is suspected for can be blamed on the parent.
1353 static void pass_whole_blame(struct blame_scoreboard *sb,
1354 struct blame_origin *origin, struct blame_origin *porigin)
1356 struct blame_entry *e, *suspects;
1358 if (!porigin->file.ptr && origin->file.ptr) {
1359 /* Steal its file */
1360 porigin->file = origin->file;
1361 origin->file.ptr = NULL;
1363 suspects = origin->suspects;
1364 origin->suspects = NULL;
1365 for (e = suspects; e; e = e->next) {
1366 blame_origin_incref(porigin);
1367 blame_origin_decref(e->suspect);
1368 e->suspect = porigin;
1370 queue_blames(sb, porigin, suspects);
1374 * We pass blame from the current commit to its parents. We keep saying
1375 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1376 * exonerate ourselves.
1378 static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,
1379 int reverse)
1381 if (!reverse) {
1382 if (revs->first_parent_only &&
1383 commit->parents &&
1384 commit->parents->next) {
1385 free_commit_list(commit->parents->next);
1386 commit->parents->next = NULL;
1388 return commit->parents;
1390 return lookup_decoration(&revs->children, &commit->object);
1393 static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)
1395 struct commit_list *l = first_scapegoat(revs, commit, reverse);
1396 return commit_list_count(l);
1399 /* Distribute collected unsorted blames to the respected sorted lists
1400 * in the various origins.
1402 static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)
1404 blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
1405 compare_blame_suspect);
1406 while (blamed)
1408 struct blame_origin *porigin = blamed->suspect;
1409 struct blame_entry *suspects = NULL;
1410 do {
1411 struct blame_entry *next = blamed->next;
1412 blamed->next = suspects;
1413 suspects = blamed;
1414 blamed = next;
1415 } while (blamed && blamed->suspect == porigin);
1416 suspects = reverse_blame(suspects, NULL);
1417 queue_blames(sb, porigin, suspects);
1421 #define MAXSG 16
1423 static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)
1425 struct rev_info *revs = sb->revs;
1426 int i, pass, num_sg;
1427 struct commit *commit = origin->commit;
1428 struct commit_list *sg;
1429 struct blame_origin *sg_buf[MAXSG];
1430 struct blame_origin *porigin, **sg_origin = sg_buf;
1431 struct blame_entry *toosmall = NULL;
1432 struct blame_entry *blames, **blametail = &blames;
1434 num_sg = num_scapegoats(revs, commit, sb->reverse);
1435 if (!num_sg)
1436 goto finish;
1437 else if (num_sg < ARRAY_SIZE(sg_buf))
1438 memset(sg_buf, 0, sizeof(sg_buf));
1439 else
1440 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1443 * The first pass looks for unrenamed path to optimize for
1444 * common cases, then we look for renames in the second pass.
1446 for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
1447 struct blame_origin *(*find)(struct repository *, struct commit *, struct blame_origin *);
1448 find = pass ? find_rename : find_origin;
1450 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1451 i < num_sg && sg;
1452 sg = sg->next, i++) {
1453 struct commit *p = sg->item;
1454 int j, same;
1456 if (sg_origin[i])
1457 continue;
1458 if (parse_commit(p))
1459 continue;
1460 porigin = find(sb->repo, p, origin);
1461 if (!porigin)
1462 continue;
1463 if (oideq(&porigin->blob_oid, &origin->blob_oid)) {
1464 pass_whole_blame(sb, origin, porigin);
1465 blame_origin_decref(porigin);
1466 goto finish;
1468 for (j = same = 0; j < i; j++)
1469 if (sg_origin[j] &&
1470 oideq(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
1471 same = 1;
1472 break;
1474 if (!same)
1475 sg_origin[i] = porigin;
1476 else
1477 blame_origin_decref(porigin);
1481 sb->num_commits++;
1482 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1483 i < num_sg && sg;
1484 sg = sg->next, i++) {
1485 struct blame_origin *porigin = sg_origin[i];
1486 if (!porigin)
1487 continue;
1488 if (!origin->previous) {
1489 blame_origin_incref(porigin);
1490 origin->previous = porigin;
1492 pass_blame_to_parent(sb, origin, porigin);
1493 if (!origin->suspects)
1494 goto finish;
1498 * Optionally find moves in parents' files.
1500 if (opt & PICKAXE_BLAME_MOVE) {
1501 filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
1502 if (origin->suspects) {
1503 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1504 i < num_sg && sg;
1505 sg = sg->next, i++) {
1506 struct blame_origin *porigin = sg_origin[i];
1507 if (!porigin)
1508 continue;
1509 find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
1510 if (!origin->suspects)
1511 break;
1517 * Optionally find copies from parents' files.
1519 if (opt & PICKAXE_BLAME_COPY) {
1520 if (sb->copy_score > sb->move_score)
1521 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1522 else if (sb->copy_score < sb->move_score) {
1523 origin->suspects = blame_merge(origin->suspects, toosmall);
1524 toosmall = NULL;
1525 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1527 if (!origin->suspects)
1528 goto finish;
1530 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1531 i < num_sg && sg;
1532 sg = sg->next, i++) {
1533 struct blame_origin *porigin = sg_origin[i];
1534 find_copy_in_parent(sb, &blametail, &toosmall,
1535 origin, sg->item, porigin, opt);
1536 if (!origin->suspects)
1537 goto finish;
1541 finish:
1542 *blametail = NULL;
1543 distribute_blame(sb, blames);
1545 * prepend toosmall to origin->suspects
1547 * There is no point in sorting: this ends up on a big
1548 * unsorted list in the caller anyway.
1550 if (toosmall) {
1551 struct blame_entry **tail = &toosmall;
1552 while (*tail)
1553 tail = &(*tail)->next;
1554 *tail = origin->suspects;
1555 origin->suspects = toosmall;
1557 for (i = 0; i < num_sg; i++) {
1558 if (sg_origin[i]) {
1559 drop_origin_blob(sg_origin[i]);
1560 blame_origin_decref(sg_origin[i]);
1563 drop_origin_blob(origin);
1564 if (sg_buf != sg_origin)
1565 free(sg_origin);
1569 * The main loop -- while we have blobs with lines whose true origin
1570 * is still unknown, pick one blob, and allow its lines to pass blames
1571 * to its parents. */
1572 void assign_blame(struct blame_scoreboard *sb, int opt)
1574 struct rev_info *revs = sb->revs;
1575 struct commit *commit = prio_queue_get(&sb->commits);
1577 while (commit) {
1578 struct blame_entry *ent;
1579 struct blame_origin *suspect = get_blame_suspects(commit);
1581 /* find one suspect to break down */
1582 while (suspect && !suspect->suspects)
1583 suspect = suspect->next;
1585 if (!suspect) {
1586 commit = prio_queue_get(&sb->commits);
1587 continue;
1590 assert(commit == suspect->commit);
1593 * We will use this suspect later in the loop,
1594 * so hold onto it in the meantime.
1596 blame_origin_incref(suspect);
1597 parse_commit(commit);
1598 if (sb->reverse ||
1599 (!(commit->object.flags & UNINTERESTING) &&
1600 !(revs->max_age != -1 && commit->date < revs->max_age)))
1601 pass_blame(sb, suspect, opt);
1602 else {
1603 commit->object.flags |= UNINTERESTING;
1604 if (commit->object.parsed)
1605 mark_parents_uninteresting(commit);
1607 /* treat root commit as boundary */
1608 if (!commit->parents && !sb->show_root)
1609 commit->object.flags |= UNINTERESTING;
1611 /* Take responsibility for the remaining entries */
1612 ent = suspect->suspects;
1613 if (ent) {
1614 suspect->guilty = 1;
1615 for (;;) {
1616 struct blame_entry *next = ent->next;
1617 if (sb->found_guilty_entry)
1618 sb->found_guilty_entry(ent, sb->found_guilty_entry_data);
1619 if (next) {
1620 ent = next;
1621 continue;
1623 ent->next = sb->ent;
1624 sb->ent = suspect->suspects;
1625 suspect->suspects = NULL;
1626 break;
1629 blame_origin_decref(suspect);
1631 if (sb->debug) /* sanity */
1632 sanity_check_refcnt(sb);
1636 static const char *get_next_line(const char *start, const char *end)
1638 const char *nl = memchr(start, '\n', end - start);
1639 return nl ? nl + 1 : end;
1643 * To allow quick access to the contents of nth line in the
1644 * final image, prepare an index in the scoreboard.
1646 static int prepare_lines(struct blame_scoreboard *sb)
1648 const char *buf = sb->final_buf;
1649 unsigned long len = sb->final_buf_size;
1650 const char *end = buf + len;
1651 const char *p;
1652 int *lineno;
1653 int num = 0;
1655 for (p = buf; p < end; p = get_next_line(p, end))
1656 num++;
1658 ALLOC_ARRAY(sb->lineno, num + 1);
1659 lineno = sb->lineno;
1661 for (p = buf; p < end; p = get_next_line(p, end))
1662 *lineno++ = p - buf;
1664 *lineno = len;
1666 sb->num_lines = num;
1667 return sb->num_lines;
1670 static struct commit *find_single_final(struct rev_info *revs,
1671 const char **name_p)
1673 int i;
1674 struct commit *found = NULL;
1675 const char *name = NULL;
1677 for (i = 0; i < revs->pending.nr; i++) {
1678 struct object *obj = revs->pending.objects[i].item;
1679 if (obj->flags & UNINTERESTING)
1680 continue;
1681 obj = deref_tag(the_repository, obj, NULL, 0);
1682 if (obj->type != OBJ_COMMIT)
1683 die("Non commit %s?", revs->pending.objects[i].name);
1684 if (found)
1685 die("More than one commit to dig from %s and %s?",
1686 revs->pending.objects[i].name, name);
1687 found = (struct commit *)obj;
1688 name = revs->pending.objects[i].name;
1690 if (name_p)
1691 *name_p = xstrdup_or_null(name);
1692 return found;
1695 static struct commit *dwim_reverse_initial(struct rev_info *revs,
1696 const char **name_p)
1699 * DWIM "git blame --reverse ONE -- PATH" as
1700 * "git blame --reverse ONE..HEAD -- PATH" but only do so
1701 * when it makes sense.
1703 struct object *obj;
1704 struct commit *head_commit;
1705 struct object_id head_oid;
1707 if (revs->pending.nr != 1)
1708 return NULL;
1710 /* Is that sole rev a committish? */
1711 obj = revs->pending.objects[0].item;
1712 obj = deref_tag(the_repository, obj, NULL, 0);
1713 if (obj->type != OBJ_COMMIT)
1714 return NULL;
1716 /* Do we have HEAD? */
1717 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
1718 return NULL;
1719 head_commit = lookup_commit_reference_gently(the_repository,
1720 &head_oid, 1);
1721 if (!head_commit)
1722 return NULL;
1724 /* Turn "ONE" into "ONE..HEAD" then */
1725 obj->flags |= UNINTERESTING;
1726 add_pending_object(revs, &head_commit->object, "HEAD");
1728 if (name_p)
1729 *name_p = revs->pending.objects[0].name;
1730 return (struct commit *)obj;
1733 static struct commit *find_single_initial(struct rev_info *revs,
1734 const char **name_p)
1736 int i;
1737 struct commit *found = NULL;
1738 const char *name = NULL;
1741 * There must be one and only one negative commit, and it must be
1742 * the boundary.
1744 for (i = 0; i < revs->pending.nr; i++) {
1745 struct object *obj = revs->pending.objects[i].item;
1746 if (!(obj->flags & UNINTERESTING))
1747 continue;
1748 obj = deref_tag(the_repository, obj, NULL, 0);
1749 if (obj->type != OBJ_COMMIT)
1750 die("Non commit %s?", revs->pending.objects[i].name);
1751 if (found)
1752 die("More than one commit to dig up from, %s and %s?",
1753 revs->pending.objects[i].name, name);
1754 found = (struct commit *) obj;
1755 name = revs->pending.objects[i].name;
1758 if (!name)
1759 found = dwim_reverse_initial(revs, &name);
1760 if (!name)
1761 die("No commit to dig up from?");
1763 if (name_p)
1764 *name_p = xstrdup(name);
1765 return found;
1768 void init_scoreboard(struct blame_scoreboard *sb)
1770 memset(sb, 0, sizeof(struct blame_scoreboard));
1771 sb->move_score = BLAME_DEFAULT_MOVE_SCORE;
1772 sb->copy_score = BLAME_DEFAULT_COPY_SCORE;
1775 void setup_scoreboard(struct blame_scoreboard *sb,
1776 const char *path,
1777 struct blame_origin **orig)
1779 const char *final_commit_name = NULL;
1780 struct blame_origin *o;
1781 struct commit *final_commit = NULL;
1782 enum object_type type;
1784 init_blame_suspects(&blame_suspects);
1786 if (sb->reverse && sb->contents_from)
1787 die(_("--contents and --reverse do not blend well."));
1789 if (!sb->repo)
1790 BUG("repo is NULL");
1792 if (!sb->reverse) {
1793 sb->final = find_single_final(sb->revs, &final_commit_name);
1794 sb->commits.compare = compare_commits_by_commit_date;
1795 } else {
1796 sb->final = find_single_initial(sb->revs, &final_commit_name);
1797 sb->commits.compare = compare_commits_by_reverse_commit_date;
1800 if (sb->final && sb->contents_from)
1801 die(_("cannot use --contents with final commit object name"));
1803 if (sb->reverse && sb->revs->first_parent_only)
1804 sb->revs->children.name = NULL;
1806 if (!sb->final) {
1808 * "--not A B -- path" without anything positive;
1809 * do not default to HEAD, but use the working tree
1810 * or "--contents".
1812 setup_work_tree();
1813 sb->final = fake_working_tree_commit(sb->repo,
1814 &sb->revs->diffopt,
1815 path, sb->contents_from);
1816 add_pending_object(sb->revs, &(sb->final->object), ":");
1819 if (sb->reverse && sb->revs->first_parent_only) {
1820 final_commit = find_single_final(sb->revs, NULL);
1821 if (!final_commit)
1822 die(_("--reverse and --first-parent together require specified latest commit"));
1826 * If we have bottom, this will mark the ancestors of the
1827 * bottom commits we would reach while traversing as
1828 * uninteresting.
1830 if (prepare_revision_walk(sb->revs))
1831 die(_("revision walk setup failed"));
1833 if (sb->reverse && sb->revs->first_parent_only) {
1834 struct commit *c = final_commit;
1836 sb->revs->children.name = "children";
1837 while (c->parents &&
1838 !oideq(&c->object.oid, &sb->final->object.oid)) {
1839 struct commit_list *l = xcalloc(1, sizeof(*l));
1841 l->item = c;
1842 if (add_decoration(&sb->revs->children,
1843 &c->parents->item->object, l))
1844 BUG("not unique item in first-parent chain");
1845 c = c->parents->item;
1848 if (!oideq(&c->object.oid, &sb->final->object.oid))
1849 die(_("--reverse --first-parent together require range along first-parent chain"));
1852 if (is_null_oid(&sb->final->object.oid)) {
1853 o = get_blame_suspects(sb->final);
1854 sb->final_buf = xmemdupz(o->file.ptr, o->file.size);
1855 sb->final_buf_size = o->file.size;
1857 else {
1858 o = get_origin(sb->final, path);
1859 if (fill_blob_sha1_and_mode(sb->repo, o))
1860 die(_("no such path %s in %s"), path, final_commit_name);
1862 if (sb->revs->diffopt.flags.allow_textconv &&
1863 textconv_object(sb->repo, path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
1864 &sb->final_buf_size))
1866 else
1867 sb->final_buf = read_object_file(&o->blob_oid, &type,
1868 &sb->final_buf_size);
1870 if (!sb->final_buf)
1871 die(_("cannot read blob %s for path %s"),
1872 oid_to_hex(&o->blob_oid),
1873 path);
1875 sb->num_read_blob++;
1876 prepare_lines(sb);
1878 if (orig)
1879 *orig = o;
1881 free((char *)final_commit_name);
1886 struct blame_entry *blame_entry_prepend(struct blame_entry *head,
1887 long start, long end,
1888 struct blame_origin *o)
1890 struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
1891 new_head->lno = start;
1892 new_head->num_lines = end - start;
1893 new_head->suspect = o;
1894 new_head->s_lno = start;
1895 new_head->next = head;
1896 blame_origin_incref(o);
1897 return new_head;