Merge branch 'jt/http-redact-cookies' into maint
[git.git] / blame.c
blob2893f3c1030aab91a42ff9e0daf8a54ba8c3ef3c
1 #include "cache.h"
2 #include "refs.h"
3 #include "cache-tree.h"
4 #include "mergesort.h"
5 #include "diff.h"
6 #include "diffcore.h"
7 #include "tag.h"
8 #include "blame.h"
10 void blame_origin_decref(struct blame_origin *o)
12 if (o && --o->refcnt <= 0) {
13 struct blame_origin *p, *l = NULL;
14 if (o->previous)
15 blame_origin_decref(o->previous);
16 free(o->file.ptr);
17 /* Should be present exactly once in commit chain */
18 for (p = o->commit->util; p; l = p, p = p->next) {
19 if (p == o) {
20 if (l)
21 l->next = p->next;
22 else
23 o->commit->util = p->next;
24 free(o);
25 return;
28 die("internal error in blame_origin_decref");
33 * Given a commit and a path in it, create a new origin structure.
34 * The callers that add blame to the scoreboard should use
35 * get_origin() to obtain shared, refcounted copy instead of calling
36 * this function directly.
38 static struct blame_origin *make_origin(struct commit *commit, const char *path)
40 struct blame_origin *o;
41 FLEX_ALLOC_STR(o, path, path);
42 o->commit = commit;
43 o->refcnt = 1;
44 o->next = commit->util;
45 commit->util = o;
46 return o;
50 * Locate an existing origin or create a new one.
51 * This moves the origin to front position in the commit util list.
53 static struct blame_origin *get_origin(struct commit *commit, const char *path)
55 struct blame_origin *o, *l;
57 for (o = commit->util, l = NULL; o; l = o, o = o->next) {
58 if (!strcmp(o->path, path)) {
59 /* bump to front */
60 if (l) {
61 l->next = o->next;
62 o->next = commit->util;
63 commit->util = o;
65 return blame_origin_incref(o);
68 return make_origin(commit, path);
73 static void verify_working_tree_path(struct commit *work_tree, const char *path)
75 struct commit_list *parents;
76 int pos;
78 for (parents = work_tree->parents; parents; parents = parents->next) {
79 const struct object_id *commit_oid = &parents->item->object.oid;
80 struct object_id blob_oid;
81 unsigned mode;
83 if (!get_tree_entry(commit_oid->hash, path, blob_oid.hash, &mode) &&
84 sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
85 return;
88 pos = cache_name_pos(path, strlen(path));
89 if (pos >= 0)
90 ; /* path is in the index */
91 else if (-1 - pos < active_nr &&
92 !strcmp(active_cache[-1 - pos]->name, path))
93 ; /* path is in the index, unmerged */
94 else
95 die("no such path '%s' in HEAD", path);
98 static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
100 struct commit *parent;
102 parent = lookup_commit_reference(oid);
103 if (!parent)
104 die("no such commit %s", oid_to_hex(oid));
105 return &commit_list_insert(parent, tail)->next;
108 static void append_merge_parents(struct commit_list **tail)
110 int merge_head;
111 struct strbuf line = STRBUF_INIT;
113 merge_head = open(git_path_merge_head(), O_RDONLY);
114 if (merge_head < 0) {
115 if (errno == ENOENT)
116 return;
117 die("cannot open '%s' for reading", git_path_merge_head());
120 while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
121 struct object_id oid;
122 if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
123 die("unknown line in '%s': %s", git_path_merge_head(), line.buf);
124 tail = append_parent(tail, &oid);
126 close(merge_head);
127 strbuf_release(&line);
131 * This isn't as simple as passing sb->buf and sb->len, because we
132 * want to transfer ownership of the buffer to the commit (so we
133 * must use detach).
135 static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb)
137 size_t len;
138 void *buf = strbuf_detach(sb, &len);
139 set_commit_buffer(c, buf, len);
143 * Prepare a dummy commit that represents the work tree (or staged) item.
144 * Note that annotating work tree item never works in the reverse.
146 static struct commit *fake_working_tree_commit(struct diff_options *opt,
147 const char *path,
148 const char *contents_from)
150 struct commit *commit;
151 struct blame_origin *origin;
152 struct commit_list **parent_tail, *parent;
153 struct object_id head_oid;
154 struct strbuf buf = STRBUF_INIT;
155 const char *ident;
156 time_t now;
157 int size, len;
158 struct cache_entry *ce;
159 unsigned mode;
160 struct strbuf msg = STRBUF_INIT;
162 read_cache();
163 time(&now);
164 commit = alloc_commit_node();
165 commit->object.parsed = 1;
166 commit->date = now;
167 parent_tail = &commit->parents;
169 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
170 die("no such ref: HEAD");
172 parent_tail = append_parent(parent_tail, &head_oid);
173 append_merge_parents(parent_tail);
174 verify_working_tree_path(commit, path);
176 origin = make_origin(commit, path);
178 ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
179 strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
180 for (parent = commit->parents; parent; parent = parent->next)
181 strbuf_addf(&msg, "parent %s\n",
182 oid_to_hex(&parent->item->object.oid));
183 strbuf_addf(&msg,
184 "author %s\n"
185 "committer %s\n\n"
186 "Version of %s from %s\n",
187 ident, ident, path,
188 (!contents_from ? path :
189 (!strcmp(contents_from, "-") ? "standard input" : contents_from)));
190 set_commit_buffer_from_strbuf(commit, &msg);
192 if (!contents_from || strcmp("-", contents_from)) {
193 struct stat st;
194 const char *read_from;
195 char *buf_ptr;
196 unsigned long buf_len;
198 if (contents_from) {
199 if (stat(contents_from, &st) < 0)
200 die_errno("Cannot stat '%s'", contents_from);
201 read_from = contents_from;
203 else {
204 if (lstat(path, &st) < 0)
205 die_errno("Cannot lstat '%s'", path);
206 read_from = path;
208 mode = canon_mode(st.st_mode);
210 switch (st.st_mode & S_IFMT) {
211 case S_IFREG:
212 if (opt->flags.allow_textconv &&
213 textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
214 strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
215 else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
216 die_errno("cannot open or read '%s'", read_from);
217 break;
218 case S_IFLNK:
219 if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
220 die_errno("cannot readlink '%s'", read_from);
221 break;
222 default:
223 die("unsupported file type %s", read_from);
226 else {
227 /* Reading from stdin */
228 mode = 0;
229 if (strbuf_read(&buf, 0, 0) < 0)
230 die_errno("failed to read from stdin");
232 convert_to_git(&the_index, path, buf.buf, buf.len, &buf, 0);
233 origin->file.ptr = buf.buf;
234 origin->file.size = buf.len;
235 pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_oid.hash);
238 * Read the current index, replace the path entry with
239 * origin->blob_sha1 without mucking with its mode or type
240 * bits; we are not going to write this index out -- we just
241 * want to run "diff-index --cached".
243 discard_cache();
244 read_cache();
246 len = strlen(path);
247 if (!mode) {
248 int pos = cache_name_pos(path, len);
249 if (0 <= pos)
250 mode = active_cache[pos]->ce_mode;
251 else
252 /* Let's not bother reading from HEAD tree */
253 mode = S_IFREG | 0644;
255 size = cache_entry_size(len);
256 ce = xcalloc(1, size);
257 oidcpy(&ce->oid, &origin->blob_oid);
258 memcpy(ce->name, path, len);
259 ce->ce_flags = create_ce_flags(0);
260 ce->ce_namelen = len;
261 ce->ce_mode = create_ce_mode(mode);
262 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
264 cache_tree_invalidate_path(&the_index, path);
266 return commit;
271 static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
272 xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts)
274 xpparam_t xpp = {0};
275 xdemitconf_t xecfg = {0};
276 xdemitcb_t ecb = {NULL};
278 xpp.flags = xdl_opts;
279 xecfg.hunk_func = hunk_func;
280 ecb.priv = cb_data;
281 return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
285 * Given an origin, prepare mmfile_t structure to be used by the
286 * diff machinery
288 static void fill_origin_blob(struct diff_options *opt,
289 struct blame_origin *o, mmfile_t *file, int *num_read_blob)
291 if (!o->file.ptr) {
292 enum object_type type;
293 unsigned long file_size;
295 (*num_read_blob)++;
296 if (opt->flags.allow_textconv &&
297 textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
299 else
300 file->ptr = read_sha1_file(o->blob_oid.hash, &type,
301 &file_size);
302 file->size = file_size;
304 if (!file->ptr)
305 die("Cannot read blob %s for path %s",
306 oid_to_hex(&o->blob_oid),
307 o->path);
308 o->file = *file;
310 else
311 *file = o->file;
314 static void drop_origin_blob(struct blame_origin *o)
316 if (o->file.ptr) {
317 FREE_AND_NULL(o->file.ptr);
322 * Any merge of blames happens on lists of blames that arrived via
323 * different parents in a single suspect. In this case, we want to
324 * sort according to the suspect line numbers as opposed to the final
325 * image line numbers. The function body is somewhat longish because
326 * it avoids unnecessary writes.
329 static struct blame_entry *blame_merge(struct blame_entry *list1,
330 struct blame_entry *list2)
332 struct blame_entry *p1 = list1, *p2 = list2,
333 **tail = &list1;
335 if (!p1)
336 return p2;
337 if (!p2)
338 return p1;
340 if (p1->s_lno <= p2->s_lno) {
341 do {
342 tail = &p1->next;
343 if ((p1 = *tail) == NULL) {
344 *tail = p2;
345 return list1;
347 } while (p1->s_lno <= p2->s_lno);
349 for (;;) {
350 *tail = p2;
351 do {
352 tail = &p2->next;
353 if ((p2 = *tail) == NULL) {
354 *tail = p1;
355 return list1;
357 } while (p1->s_lno > p2->s_lno);
358 *tail = p1;
359 do {
360 tail = &p1->next;
361 if ((p1 = *tail) == NULL) {
362 *tail = p2;
363 return list1;
365 } while (p1->s_lno <= p2->s_lno);
369 static void *get_next_blame(const void *p)
371 return ((struct blame_entry *)p)->next;
374 static void set_next_blame(void *p1, void *p2)
376 ((struct blame_entry *)p1)->next = p2;
380 * Final image line numbers are all different, so we don't need a
381 * three-way comparison here.
384 static int compare_blame_final(const void *p1, const void *p2)
386 return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
387 ? 1 : -1;
390 static int compare_blame_suspect(const void *p1, const void *p2)
392 const struct blame_entry *s1 = p1, *s2 = p2;
394 * to allow for collating suspects, we sort according to the
395 * respective pointer value as the primary sorting criterion.
396 * The actual relation is pretty unimportant as long as it
397 * establishes a total order. Comparing as integers gives us
398 * that.
400 if (s1->suspect != s2->suspect)
401 return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
402 if (s1->s_lno == s2->s_lno)
403 return 0;
404 return s1->s_lno > s2->s_lno ? 1 : -1;
407 void blame_sort_final(struct blame_scoreboard *sb)
409 sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
410 compare_blame_final);
413 static int compare_commits_by_reverse_commit_date(const void *a,
414 const void *b,
415 void *c)
417 return -compare_commits_by_commit_date(a, b, c);
421 * For debugging -- origin is refcounted, and this asserts that
422 * we do not underflow.
424 static void sanity_check_refcnt(struct blame_scoreboard *sb)
426 int baa = 0;
427 struct blame_entry *ent;
429 for (ent = sb->ent; ent; ent = ent->next) {
430 /* Nobody should have zero or negative refcnt */
431 if (ent->suspect->refcnt <= 0) {
432 fprintf(stderr, "%s in %s has negative refcnt %d\n",
433 ent->suspect->path,
434 oid_to_hex(&ent->suspect->commit->object.oid),
435 ent->suspect->refcnt);
436 baa = 1;
439 if (baa)
440 sb->on_sanity_fail(sb, baa);
444 * If two blame entries that are next to each other came from
445 * contiguous lines in the same origin (i.e. <commit, path> pair),
446 * merge them together.
448 void blame_coalesce(struct blame_scoreboard *sb)
450 struct blame_entry *ent, *next;
452 for (ent = sb->ent; ent && (next = ent->next); ent = next) {
453 if (ent->suspect == next->suspect &&
454 ent->s_lno + ent->num_lines == next->s_lno) {
455 ent->num_lines += next->num_lines;
456 ent->next = next->next;
457 blame_origin_decref(next->suspect);
458 free(next);
459 ent->score = 0;
460 next = ent; /* again */
464 if (sb->debug) /* sanity */
465 sanity_check_refcnt(sb);
469 * Merge the given sorted list of blames into a preexisting origin.
470 * If there were no previous blames to that commit, it is entered into
471 * the commit priority queue of the score board.
474 static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin,
475 struct blame_entry *sorted)
477 if (porigin->suspects)
478 porigin->suspects = blame_merge(porigin->suspects, sorted);
479 else {
480 struct blame_origin *o;
481 for (o = porigin->commit->util; o; o = o->next) {
482 if (o->suspects) {
483 porigin->suspects = sorted;
484 return;
487 porigin->suspects = sorted;
488 prio_queue_put(&sb->commits, porigin->commit);
493 * Fill the blob_sha1 field of an origin if it hasn't, so that later
494 * call to fill_origin_blob() can use it to locate the data. blob_sha1
495 * for an origin is also used to pass the blame for the entire file to
496 * the parent to detect the case where a child's blob is identical to
497 * that of its parent's.
499 * This also fills origin->mode for corresponding tree path.
501 static int fill_blob_sha1_and_mode(struct blame_origin *origin)
503 if (!is_null_oid(&origin->blob_oid))
504 return 0;
505 if (get_tree_entry(origin->commit->object.oid.hash,
506 origin->path,
507 origin->blob_oid.hash, &origin->mode))
508 goto error_out;
509 if (sha1_object_info(origin->blob_oid.hash, NULL) != OBJ_BLOB)
510 goto error_out;
511 return 0;
512 error_out:
513 oidclr(&origin->blob_oid);
514 origin->mode = S_IFINVALID;
515 return -1;
519 * We have an origin -- check if the same path exists in the
520 * parent and return an origin structure to represent it.
522 static struct blame_origin *find_origin(struct commit *parent,
523 struct blame_origin *origin)
525 struct blame_origin *porigin;
526 struct diff_options diff_opts;
527 const char *paths[2];
529 /* First check any existing origins */
530 for (porigin = parent->util; porigin; porigin = porigin->next)
531 if (!strcmp(porigin->path, origin->path)) {
533 * The same path between origin and its parent
534 * without renaming -- the most common case.
536 return blame_origin_incref (porigin);
539 /* See if the origin->path is different between parent
540 * and origin first. Most of the time they are the
541 * same and diff-tree is fairly efficient about this.
543 diff_setup(&diff_opts);
544 diff_opts.flags.recursive = 1;
545 diff_opts.detect_rename = 0;
546 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
547 paths[0] = origin->path;
548 paths[1] = NULL;
550 parse_pathspec(&diff_opts.pathspec,
551 PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
552 PATHSPEC_LITERAL_PATH, "", paths);
553 diff_setup_done(&diff_opts);
555 if (is_null_oid(&origin->commit->object.oid))
556 do_diff_cache(&parent->tree->object.oid, &diff_opts);
557 else
558 diff_tree_oid(&parent->tree->object.oid,
559 &origin->commit->tree->object.oid,
560 "", &diff_opts);
561 diffcore_std(&diff_opts);
563 if (!diff_queued_diff.nr) {
564 /* The path is the same as parent */
565 porigin = get_origin(parent, origin->path);
566 oidcpy(&porigin->blob_oid, &origin->blob_oid);
567 porigin->mode = origin->mode;
568 } else {
570 * Since origin->path is a pathspec, if the parent
571 * commit had it as a directory, we will see a whole
572 * bunch of deletion of files in the directory that we
573 * do not care about.
575 int i;
576 struct diff_filepair *p = NULL;
577 for (i = 0; i < diff_queued_diff.nr; i++) {
578 const char *name;
579 p = diff_queued_diff.queue[i];
580 name = p->one->path ? p->one->path : p->two->path;
581 if (!strcmp(name, origin->path))
582 break;
584 if (!p)
585 die("internal error in blame::find_origin");
586 switch (p->status) {
587 default:
588 die("internal error in blame::find_origin (%c)",
589 p->status);
590 case 'M':
591 porigin = get_origin(parent, origin->path);
592 oidcpy(&porigin->blob_oid, &p->one->oid);
593 porigin->mode = p->one->mode;
594 break;
595 case 'A':
596 case 'T':
597 /* Did not exist in parent, or type changed */
598 break;
601 diff_flush(&diff_opts);
602 clear_pathspec(&diff_opts.pathspec);
603 return porigin;
607 * We have an origin -- find the path that corresponds to it in its
608 * parent and return an origin structure to represent it.
610 static struct blame_origin *find_rename(struct commit *parent,
611 struct blame_origin *origin)
613 struct blame_origin *porigin = NULL;
614 struct diff_options diff_opts;
615 int i;
617 diff_setup(&diff_opts);
618 diff_opts.flags.recursive = 1;
619 diff_opts.detect_rename = DIFF_DETECT_RENAME;
620 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
621 diff_opts.single_follow = origin->path;
622 diff_setup_done(&diff_opts);
624 if (is_null_oid(&origin->commit->object.oid))
625 do_diff_cache(&parent->tree->object.oid, &diff_opts);
626 else
627 diff_tree_oid(&parent->tree->object.oid,
628 &origin->commit->tree->object.oid,
629 "", &diff_opts);
630 diffcore_std(&diff_opts);
632 for (i = 0; i < diff_queued_diff.nr; i++) {
633 struct diff_filepair *p = diff_queued_diff.queue[i];
634 if ((p->status == 'R' || p->status == 'C') &&
635 !strcmp(p->two->path, origin->path)) {
636 porigin = get_origin(parent, p->one->path);
637 oidcpy(&porigin->blob_oid, &p->one->oid);
638 porigin->mode = p->one->mode;
639 break;
642 diff_flush(&diff_opts);
643 clear_pathspec(&diff_opts.pathspec);
644 return porigin;
648 * Append a new blame entry to a given output queue.
650 static void add_blame_entry(struct blame_entry ***queue,
651 const struct blame_entry *src)
653 struct blame_entry *e = xmalloc(sizeof(*e));
654 memcpy(e, src, sizeof(*e));
655 blame_origin_incref(e->suspect);
657 e->next = **queue;
658 **queue = e;
659 *queue = &e->next;
663 * src typically is on-stack; we want to copy the information in it to
664 * a malloced blame_entry that gets added to the given queue. The
665 * origin of dst loses a refcnt.
667 static void dup_entry(struct blame_entry ***queue,
668 struct blame_entry *dst, struct blame_entry *src)
670 blame_origin_incref(src->suspect);
671 blame_origin_decref(dst->suspect);
672 memcpy(dst, src, sizeof(*src));
673 dst->next = **queue;
674 **queue = dst;
675 *queue = &dst->next;
678 const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
680 return sb->final_buf + sb->lineno[lno];
684 * It is known that lines between tlno to same came from parent, and e
685 * has an overlap with that range. it also is known that parent's
686 * line plno corresponds to e's line tlno.
688 * <---- e ----->
689 * <------>
690 * <------------>
691 * <------------>
692 * <------------------>
694 * Split e into potentially three parts; before this chunk, the chunk
695 * to be blamed for the parent, and after that portion.
697 static void split_overlap(struct blame_entry *split,
698 struct blame_entry *e,
699 int tlno, int plno, int same,
700 struct blame_origin *parent)
702 int chunk_end_lno;
703 memset(split, 0, sizeof(struct blame_entry [3]));
705 if (e->s_lno < tlno) {
706 /* there is a pre-chunk part not blamed on parent */
707 split[0].suspect = blame_origin_incref(e->suspect);
708 split[0].lno = e->lno;
709 split[0].s_lno = e->s_lno;
710 split[0].num_lines = tlno - e->s_lno;
711 split[1].lno = e->lno + tlno - e->s_lno;
712 split[1].s_lno = plno;
714 else {
715 split[1].lno = e->lno;
716 split[1].s_lno = plno + (e->s_lno - tlno);
719 if (same < e->s_lno + e->num_lines) {
720 /* there is a post-chunk part not blamed on parent */
721 split[2].suspect = blame_origin_incref(e->suspect);
722 split[2].lno = e->lno + (same - e->s_lno);
723 split[2].s_lno = e->s_lno + (same - e->s_lno);
724 split[2].num_lines = e->s_lno + e->num_lines - same;
725 chunk_end_lno = split[2].lno;
727 else
728 chunk_end_lno = e->lno + e->num_lines;
729 split[1].num_lines = chunk_end_lno - split[1].lno;
732 * if it turns out there is nothing to blame the parent for,
733 * forget about the splitting. !split[1].suspect signals this.
735 if (split[1].num_lines < 1)
736 return;
737 split[1].suspect = blame_origin_incref(parent);
741 * split_overlap() divided an existing blame e into up to three parts
742 * in split. Any assigned blame is moved to queue to
743 * reflect the split.
745 static void split_blame(struct blame_entry ***blamed,
746 struct blame_entry ***unblamed,
747 struct blame_entry *split,
748 struct blame_entry *e)
750 if (split[0].suspect && split[2].suspect) {
751 /* The first part (reuse storage for the existing entry e) */
752 dup_entry(unblamed, e, &split[0]);
754 /* The last part -- me */
755 add_blame_entry(unblamed, &split[2]);
757 /* ... and the middle part -- parent */
758 add_blame_entry(blamed, &split[1]);
760 else if (!split[0].suspect && !split[2].suspect)
762 * The parent covers the entire area; reuse storage for
763 * e and replace it with the parent.
765 dup_entry(blamed, e, &split[1]);
766 else if (split[0].suspect) {
767 /* me and then parent */
768 dup_entry(unblamed, e, &split[0]);
769 add_blame_entry(blamed, &split[1]);
771 else {
772 /* parent and then me */
773 dup_entry(blamed, e, &split[1]);
774 add_blame_entry(unblamed, &split[2]);
779 * After splitting the blame, the origins used by the
780 * on-stack blame_entry should lose one refcnt each.
782 static void decref_split(struct blame_entry *split)
784 int i;
786 for (i = 0; i < 3; i++)
787 blame_origin_decref(split[i].suspect);
791 * reverse_blame reverses the list given in head, appending tail.
792 * That allows us to build lists in reverse order, then reverse them
793 * afterwards. This can be faster than building the list in proper
794 * order right away. The reason is that building in proper order
795 * requires writing a link in the _previous_ element, while building
796 * in reverse order just requires placing the list head into the
797 * _current_ element.
800 static struct blame_entry *reverse_blame(struct blame_entry *head,
801 struct blame_entry *tail)
803 while (head) {
804 struct blame_entry *next = head->next;
805 head->next = tail;
806 tail = head;
807 head = next;
809 return tail;
813 * Process one hunk from the patch between the current suspect for
814 * blame_entry e and its parent. This first blames any unfinished
815 * entries before the chunk (which is where target and parent start
816 * differing) on the parent, and then splits blame entries at the
817 * start and at the end of the difference region. Since use of -M and
818 * -C options may lead to overlapping/duplicate source line number
819 * ranges, all we can rely on from sorting/merging is the order of the
820 * first suspect line number.
822 static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
823 int tlno, int offset, int same,
824 struct blame_origin *parent)
826 struct blame_entry *e = **srcq;
827 struct blame_entry *samep = NULL, *diffp = NULL;
829 while (e && e->s_lno < tlno) {
830 struct blame_entry *next = e->next;
832 * current record starts before differing portion. If
833 * it reaches into it, we need to split it up and
834 * examine the second part separately.
836 if (e->s_lno + e->num_lines > tlno) {
837 /* Move second half to a new record */
838 int len = tlno - e->s_lno;
839 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
840 n->suspect = e->suspect;
841 n->lno = e->lno + len;
842 n->s_lno = e->s_lno + len;
843 n->num_lines = e->num_lines - len;
844 e->num_lines = len;
845 e->score = 0;
846 /* Push new record to diffp */
847 n->next = diffp;
848 diffp = n;
849 } else
850 blame_origin_decref(e->suspect);
851 /* Pass blame for everything before the differing
852 * chunk to the parent */
853 e->suspect = blame_origin_incref(parent);
854 e->s_lno += offset;
855 e->next = samep;
856 samep = e;
857 e = next;
860 * As we don't know how much of a common stretch after this
861 * diff will occur, the currently blamed parts are all that we
862 * can assign to the parent for now.
865 if (samep) {
866 **dstq = reverse_blame(samep, **dstq);
867 *dstq = &samep->next;
870 * Prepend the split off portions: everything after e starts
871 * after the blameable portion.
873 e = reverse_blame(diffp, e);
876 * Now retain records on the target while parts are different
877 * from the parent.
879 samep = NULL;
880 diffp = NULL;
881 while (e && e->s_lno < same) {
882 struct blame_entry *next = e->next;
885 * If current record extends into sameness, need to split.
887 if (e->s_lno + e->num_lines > same) {
889 * Move second half to a new record to be
890 * processed by later chunks
892 int len = same - e->s_lno;
893 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
894 n->suspect = blame_origin_incref(e->suspect);
895 n->lno = e->lno + len;
896 n->s_lno = e->s_lno + len;
897 n->num_lines = e->num_lines - len;
898 e->num_lines = len;
899 e->score = 0;
900 /* Push new record to samep */
901 n->next = samep;
902 samep = n;
904 e->next = diffp;
905 diffp = e;
906 e = next;
908 **srcq = reverse_blame(diffp, reverse_blame(samep, e));
909 /* Move across elements that are in the unblamable portion */
910 if (diffp)
911 *srcq = &diffp->next;
914 struct blame_chunk_cb_data {
915 struct blame_origin *parent;
916 long offset;
917 struct blame_entry **dstq;
918 struct blame_entry **srcq;
921 /* diff chunks are from parent to target */
922 static int blame_chunk_cb(long start_a, long count_a,
923 long start_b, long count_b, void *data)
925 struct blame_chunk_cb_data *d = data;
926 if (start_a - start_b != d->offset)
927 die("internal error in blame::blame_chunk_cb");
928 blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
929 start_b + count_b, d->parent);
930 d->offset = start_a + count_a - (start_b + count_b);
931 return 0;
935 * We are looking at the origin 'target' and aiming to pass blame
936 * for the lines it is suspected to its parent. Run diff to find
937 * which lines came from parent and pass blame for them.
939 static void pass_blame_to_parent(struct blame_scoreboard *sb,
940 struct blame_origin *target,
941 struct blame_origin *parent)
943 mmfile_t file_p, file_o;
944 struct blame_chunk_cb_data d;
945 struct blame_entry *newdest = NULL;
947 if (!target->suspects)
948 return; /* nothing remains for this target */
950 d.parent = parent;
951 d.offset = 0;
952 d.dstq = &newdest; d.srcq = &target->suspects;
954 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
955 fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
956 sb->num_get_patch++;
958 if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
959 die("unable to generate diff (%s -> %s)",
960 oid_to_hex(&parent->commit->object.oid),
961 oid_to_hex(&target->commit->object.oid));
962 /* The rest are the same as the parent */
963 blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
964 *d.dstq = NULL;
965 queue_blames(sb, parent, newdest);
967 return;
971 * The lines in blame_entry after splitting blames many times can become
972 * very small and trivial, and at some point it becomes pointless to
973 * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any
974 * ordinary C program, and it is not worth to say it was copied from
975 * totally unrelated file in the parent.
977 * Compute how trivial the lines in the blame_entry are.
979 unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
981 unsigned score;
982 const char *cp, *ep;
984 if (e->score)
985 return e->score;
987 score = 1;
988 cp = blame_nth_line(sb, e->lno);
989 ep = blame_nth_line(sb, e->lno + e->num_lines);
990 while (cp < ep) {
991 unsigned ch = *((unsigned char *)cp);
992 if (isalnum(ch))
993 score++;
994 cp++;
996 e->score = score;
997 return score;
1001 * best_so_far[] and this[] are both a split of an existing blame_entry
1002 * that passes blame to the parent. Maintain best_so_far the best split
1003 * so far, by comparing this and best_so_far and copying this into
1004 * bst_so_far as needed.
1006 static void copy_split_if_better(struct blame_scoreboard *sb,
1007 struct blame_entry *best_so_far,
1008 struct blame_entry *this)
1010 int i;
1012 if (!this[1].suspect)
1013 return;
1014 if (best_so_far[1].suspect) {
1015 if (blame_entry_score(sb, &this[1]) < blame_entry_score(sb, &best_so_far[1]))
1016 return;
1019 for (i = 0; i < 3; i++)
1020 blame_origin_incref(this[i].suspect);
1021 decref_split(best_so_far);
1022 memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
1026 * We are looking at a part of the final image represented by
1027 * ent (tlno and same are offset by ent->s_lno).
1028 * tlno is where we are looking at in the final image.
1029 * up to (but not including) same match preimage.
1030 * plno is where we are looking at in the preimage.
1032 * <-------------- final image ---------------------->
1033 * <------ent------>
1034 * ^tlno ^same
1035 * <---------preimage----->
1036 * ^plno
1038 * All line numbers are 0-based.
1040 static void handle_split(struct blame_scoreboard *sb,
1041 struct blame_entry *ent,
1042 int tlno, int plno, int same,
1043 struct blame_origin *parent,
1044 struct blame_entry *split)
1046 if (ent->num_lines <= tlno)
1047 return;
1048 if (tlno < same) {
1049 struct blame_entry this[3];
1050 tlno += ent->s_lno;
1051 same += ent->s_lno;
1052 split_overlap(this, ent, tlno, plno, same, parent);
1053 copy_split_if_better(sb, split, this);
1054 decref_split(this);
1058 struct handle_split_cb_data {
1059 struct blame_scoreboard *sb;
1060 struct blame_entry *ent;
1061 struct blame_origin *parent;
1062 struct blame_entry *split;
1063 long plno;
1064 long tlno;
1067 static int handle_split_cb(long start_a, long count_a,
1068 long start_b, long count_b, void *data)
1070 struct handle_split_cb_data *d = data;
1071 handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
1072 d->split);
1073 d->plno = start_a + count_a;
1074 d->tlno = start_b + count_b;
1075 return 0;
1079 * Find the lines from parent that are the same as ent so that
1080 * we can pass blames to it. file_p has the blob contents for
1081 * the parent.
1083 static void find_copy_in_blob(struct blame_scoreboard *sb,
1084 struct blame_entry *ent,
1085 struct blame_origin *parent,
1086 struct blame_entry *split,
1087 mmfile_t *file_p)
1089 const char *cp;
1090 mmfile_t file_o;
1091 struct handle_split_cb_data d;
1093 memset(&d, 0, sizeof(d));
1094 d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
1096 * Prepare mmfile that contains only the lines in ent.
1098 cp = blame_nth_line(sb, ent->lno);
1099 file_o.ptr = (char *) cp;
1100 file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
1103 * file_o is a part of final image we are annotating.
1104 * file_p partially may match that image.
1106 memset(split, 0, sizeof(struct blame_entry [3]));
1107 if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
1108 die("unable to generate diff (%s)",
1109 oid_to_hex(&parent->commit->object.oid));
1110 /* remainder, if any, all match the preimage */
1111 handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
1114 /* Move all blame entries from list *source that have a score smaller
1115 * than score_min to the front of list *small.
1116 * Returns a pointer to the link pointing to the old head of the small list.
1119 static struct blame_entry **filter_small(struct blame_scoreboard *sb,
1120 struct blame_entry **small,
1121 struct blame_entry **source,
1122 unsigned score_min)
1124 struct blame_entry *p = *source;
1125 struct blame_entry *oldsmall = *small;
1126 while (p) {
1127 if (blame_entry_score(sb, p) <= score_min) {
1128 *small = p;
1129 small = &p->next;
1130 p = *small;
1131 } else {
1132 *source = p;
1133 source = &p->next;
1134 p = *source;
1137 *small = oldsmall;
1138 *source = NULL;
1139 return small;
1143 * See if lines currently target is suspected for can be attributed to
1144 * parent.
1146 static void find_move_in_parent(struct blame_scoreboard *sb,
1147 struct blame_entry ***blamed,
1148 struct blame_entry **toosmall,
1149 struct blame_origin *target,
1150 struct blame_origin *parent)
1152 struct blame_entry *e, split[3];
1153 struct blame_entry *unblamed = target->suspects;
1154 struct blame_entry *leftover = NULL;
1155 mmfile_t file_p;
1157 if (!unblamed)
1158 return; /* nothing remains for this target */
1160 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
1161 if (!file_p.ptr)
1162 return;
1164 /* At each iteration, unblamed has a NULL-terminated list of
1165 * entries that have not yet been tested for blame. leftover
1166 * contains the reversed list of entries that have been tested
1167 * without being assignable to the parent.
1169 do {
1170 struct blame_entry **unblamedtail = &unblamed;
1171 struct blame_entry *next;
1172 for (e = unblamed; e; e = next) {
1173 next = e->next;
1174 find_copy_in_blob(sb, e, parent, split, &file_p);
1175 if (split[1].suspect &&
1176 sb->move_score < blame_entry_score(sb, &split[1])) {
1177 split_blame(blamed, &unblamedtail, split, e);
1178 } else {
1179 e->next = leftover;
1180 leftover = e;
1182 decref_split(split);
1184 *unblamedtail = NULL;
1185 toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);
1186 } while (unblamed);
1187 target->suspects = reverse_blame(leftover, NULL);
1190 struct blame_list {
1191 struct blame_entry *ent;
1192 struct blame_entry split[3];
1196 * Count the number of entries the target is suspected for,
1197 * and prepare a list of entry and the best split.
1199 static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
1200 int *num_ents_p)
1202 struct blame_entry *e;
1203 int num_ents, i;
1204 struct blame_list *blame_list = NULL;
1206 for (e = unblamed, num_ents = 0; e; e = e->next)
1207 num_ents++;
1208 if (num_ents) {
1209 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1210 for (e = unblamed, i = 0; e; e = e->next)
1211 blame_list[i++].ent = e;
1213 *num_ents_p = num_ents;
1214 return blame_list;
1218 * For lines target is suspected for, see if we can find code movement
1219 * across file boundary from the parent commit. porigin is the path
1220 * in the parent we already tried.
1222 static void find_copy_in_parent(struct blame_scoreboard *sb,
1223 struct blame_entry ***blamed,
1224 struct blame_entry **toosmall,
1225 struct blame_origin *target,
1226 struct commit *parent,
1227 struct blame_origin *porigin,
1228 int opt)
1230 struct diff_options diff_opts;
1231 int i, j;
1232 struct blame_list *blame_list;
1233 int num_ents;
1234 struct blame_entry *unblamed = target->suspects;
1235 struct blame_entry *leftover = NULL;
1237 if (!unblamed)
1238 return; /* nothing remains for this target */
1240 diff_setup(&diff_opts);
1241 diff_opts.flags.recursive = 1;
1242 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1244 diff_setup_done(&diff_opts);
1246 /* Try "find copies harder" on new path if requested;
1247 * we do not want to use diffcore_rename() actually to
1248 * match things up; find_copies_harder is set only to
1249 * force diff_tree_oid() to feed all filepairs to diff_queue,
1250 * and this code needs to be after diff_setup_done(), which
1251 * usually makes find-copies-harder imply copy detection.
1253 if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1254 || ((opt & PICKAXE_BLAME_COPY_HARDER)
1255 && (!porigin || strcmp(target->path, porigin->path))))
1256 diff_opts.flags.find_copies_harder = 1;
1258 if (is_null_oid(&target->commit->object.oid))
1259 do_diff_cache(&parent->tree->object.oid, &diff_opts);
1260 else
1261 diff_tree_oid(&parent->tree->object.oid,
1262 &target->commit->tree->object.oid,
1263 "", &diff_opts);
1265 if (!diff_opts.flags.find_copies_harder)
1266 diffcore_std(&diff_opts);
1268 do {
1269 struct blame_entry **unblamedtail = &unblamed;
1270 blame_list = setup_blame_list(unblamed, &num_ents);
1272 for (i = 0; i < diff_queued_diff.nr; i++) {
1273 struct diff_filepair *p = diff_queued_diff.queue[i];
1274 struct blame_origin *norigin;
1275 mmfile_t file_p;
1276 struct blame_entry this[3];
1278 if (!DIFF_FILE_VALID(p->one))
1279 continue; /* does not exist in parent */
1280 if (S_ISGITLINK(p->one->mode))
1281 continue; /* ignore git links */
1282 if (porigin && !strcmp(p->one->path, porigin->path))
1283 /* find_move already dealt with this path */
1284 continue;
1286 norigin = get_origin(parent, p->one->path);
1287 oidcpy(&norigin->blob_oid, &p->one->oid);
1288 norigin->mode = p->one->mode;
1289 fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
1290 if (!file_p.ptr)
1291 continue;
1293 for (j = 0; j < num_ents; j++) {
1294 find_copy_in_blob(sb, blame_list[j].ent,
1295 norigin, this, &file_p);
1296 copy_split_if_better(sb, blame_list[j].split,
1297 this);
1298 decref_split(this);
1300 blame_origin_decref(norigin);
1303 for (j = 0; j < num_ents; j++) {
1304 struct blame_entry *split = blame_list[j].split;
1305 if (split[1].suspect &&
1306 sb->copy_score < blame_entry_score(sb, &split[1])) {
1307 split_blame(blamed, &unblamedtail, split,
1308 blame_list[j].ent);
1309 } else {
1310 blame_list[j].ent->next = leftover;
1311 leftover = blame_list[j].ent;
1313 decref_split(split);
1315 free(blame_list);
1316 *unblamedtail = NULL;
1317 toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);
1318 } while (unblamed);
1319 target->suspects = reverse_blame(leftover, NULL);
1320 diff_flush(&diff_opts);
1321 clear_pathspec(&diff_opts.pathspec);
1325 * The blobs of origin and porigin exactly match, so everything
1326 * origin is suspected for can be blamed on the parent.
1328 static void pass_whole_blame(struct blame_scoreboard *sb,
1329 struct blame_origin *origin, struct blame_origin *porigin)
1331 struct blame_entry *e, *suspects;
1333 if (!porigin->file.ptr && origin->file.ptr) {
1334 /* Steal its file */
1335 porigin->file = origin->file;
1336 origin->file.ptr = NULL;
1338 suspects = origin->suspects;
1339 origin->suspects = NULL;
1340 for (e = suspects; e; e = e->next) {
1341 blame_origin_incref(porigin);
1342 blame_origin_decref(e->suspect);
1343 e->suspect = porigin;
1345 queue_blames(sb, porigin, suspects);
1349 * We pass blame from the current commit to its parents. We keep saying
1350 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1351 * exonerate ourselves.
1353 static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,
1354 int reverse)
1356 if (!reverse) {
1357 if (revs->first_parent_only &&
1358 commit->parents &&
1359 commit->parents->next) {
1360 free_commit_list(commit->parents->next);
1361 commit->parents->next = NULL;
1363 return commit->parents;
1365 return lookup_decoration(&revs->children, &commit->object);
1368 static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)
1370 struct commit_list *l = first_scapegoat(revs, commit, reverse);
1371 return commit_list_count(l);
1374 /* Distribute collected unsorted blames to the respected sorted lists
1375 * in the various origins.
1377 static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)
1379 blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
1380 compare_blame_suspect);
1381 while (blamed)
1383 struct blame_origin *porigin = blamed->suspect;
1384 struct blame_entry *suspects = NULL;
1385 do {
1386 struct blame_entry *next = blamed->next;
1387 blamed->next = suspects;
1388 suspects = blamed;
1389 blamed = next;
1390 } while (blamed && blamed->suspect == porigin);
1391 suspects = reverse_blame(suspects, NULL);
1392 queue_blames(sb, porigin, suspects);
1396 #define MAXSG 16
1398 static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)
1400 struct rev_info *revs = sb->revs;
1401 int i, pass, num_sg;
1402 struct commit *commit = origin->commit;
1403 struct commit_list *sg;
1404 struct blame_origin *sg_buf[MAXSG];
1405 struct blame_origin *porigin, **sg_origin = sg_buf;
1406 struct blame_entry *toosmall = NULL;
1407 struct blame_entry *blames, **blametail = &blames;
1409 num_sg = num_scapegoats(revs, commit, sb->reverse);
1410 if (!num_sg)
1411 goto finish;
1412 else if (num_sg < ARRAY_SIZE(sg_buf))
1413 memset(sg_buf, 0, sizeof(sg_buf));
1414 else
1415 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1418 * The first pass looks for unrenamed path to optimize for
1419 * common cases, then we look for renames in the second pass.
1421 for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
1422 struct blame_origin *(*find)(struct commit *, struct blame_origin *);
1423 find = pass ? find_rename : find_origin;
1425 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1426 i < num_sg && sg;
1427 sg = sg->next, i++) {
1428 struct commit *p = sg->item;
1429 int j, same;
1431 if (sg_origin[i])
1432 continue;
1433 if (parse_commit(p))
1434 continue;
1435 porigin = find(p, origin);
1436 if (!porigin)
1437 continue;
1438 if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
1439 pass_whole_blame(sb, origin, porigin);
1440 blame_origin_decref(porigin);
1441 goto finish;
1443 for (j = same = 0; j < i; j++)
1444 if (sg_origin[j] &&
1445 !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
1446 same = 1;
1447 break;
1449 if (!same)
1450 sg_origin[i] = porigin;
1451 else
1452 blame_origin_decref(porigin);
1456 sb->num_commits++;
1457 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1458 i < num_sg && sg;
1459 sg = sg->next, i++) {
1460 struct blame_origin *porigin = sg_origin[i];
1461 if (!porigin)
1462 continue;
1463 if (!origin->previous) {
1464 blame_origin_incref(porigin);
1465 origin->previous = porigin;
1467 pass_blame_to_parent(sb, origin, porigin);
1468 if (!origin->suspects)
1469 goto finish;
1473 * Optionally find moves in parents' files.
1475 if (opt & PICKAXE_BLAME_MOVE) {
1476 filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
1477 if (origin->suspects) {
1478 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1479 i < num_sg && sg;
1480 sg = sg->next, i++) {
1481 struct blame_origin *porigin = sg_origin[i];
1482 if (!porigin)
1483 continue;
1484 find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
1485 if (!origin->suspects)
1486 break;
1492 * Optionally find copies from parents' files.
1494 if (opt & PICKAXE_BLAME_COPY) {
1495 if (sb->copy_score > sb->move_score)
1496 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1497 else if (sb->copy_score < sb->move_score) {
1498 origin->suspects = blame_merge(origin->suspects, toosmall);
1499 toosmall = NULL;
1500 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1502 if (!origin->suspects)
1503 goto finish;
1505 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1506 i < num_sg && sg;
1507 sg = sg->next, i++) {
1508 struct blame_origin *porigin = sg_origin[i];
1509 find_copy_in_parent(sb, &blametail, &toosmall,
1510 origin, sg->item, porigin, opt);
1511 if (!origin->suspects)
1512 goto finish;
1516 finish:
1517 *blametail = NULL;
1518 distribute_blame(sb, blames);
1520 * prepend toosmall to origin->suspects
1522 * There is no point in sorting: this ends up on a big
1523 * unsorted list in the caller anyway.
1525 if (toosmall) {
1526 struct blame_entry **tail = &toosmall;
1527 while (*tail)
1528 tail = &(*tail)->next;
1529 *tail = origin->suspects;
1530 origin->suspects = toosmall;
1532 for (i = 0; i < num_sg; i++) {
1533 if (sg_origin[i]) {
1534 drop_origin_blob(sg_origin[i]);
1535 blame_origin_decref(sg_origin[i]);
1538 drop_origin_blob(origin);
1539 if (sg_buf != sg_origin)
1540 free(sg_origin);
1544 * The main loop -- while we have blobs with lines whose true origin
1545 * is still unknown, pick one blob, and allow its lines to pass blames
1546 * to its parents. */
1547 void assign_blame(struct blame_scoreboard *sb, int opt)
1549 struct rev_info *revs = sb->revs;
1550 struct commit *commit = prio_queue_get(&sb->commits);
1552 while (commit) {
1553 struct blame_entry *ent;
1554 struct blame_origin *suspect = commit->util;
1556 /* find one suspect to break down */
1557 while (suspect && !suspect->suspects)
1558 suspect = suspect->next;
1560 if (!suspect) {
1561 commit = prio_queue_get(&sb->commits);
1562 continue;
1565 assert(commit == suspect->commit);
1568 * We will use this suspect later in the loop,
1569 * so hold onto it in the meantime.
1571 blame_origin_incref(suspect);
1572 parse_commit(commit);
1573 if (sb->reverse ||
1574 (!(commit->object.flags & UNINTERESTING) &&
1575 !(revs->max_age != -1 && commit->date < revs->max_age)))
1576 pass_blame(sb, suspect, opt);
1577 else {
1578 commit->object.flags |= UNINTERESTING;
1579 if (commit->object.parsed)
1580 mark_parents_uninteresting(commit);
1582 /* treat root commit as boundary */
1583 if (!commit->parents && !sb->show_root)
1584 commit->object.flags |= UNINTERESTING;
1586 /* Take responsibility for the remaining entries */
1587 ent = suspect->suspects;
1588 if (ent) {
1589 suspect->guilty = 1;
1590 for (;;) {
1591 struct blame_entry *next = ent->next;
1592 if (sb->found_guilty_entry)
1593 sb->found_guilty_entry(ent, sb->found_guilty_entry_data);
1594 if (next) {
1595 ent = next;
1596 continue;
1598 ent->next = sb->ent;
1599 sb->ent = suspect->suspects;
1600 suspect->suspects = NULL;
1601 break;
1604 blame_origin_decref(suspect);
1606 if (sb->debug) /* sanity */
1607 sanity_check_refcnt(sb);
1611 static const char *get_next_line(const char *start, const char *end)
1613 const char *nl = memchr(start, '\n', end - start);
1614 return nl ? nl + 1 : end;
1618 * To allow quick access to the contents of nth line in the
1619 * final image, prepare an index in the scoreboard.
1621 static int prepare_lines(struct blame_scoreboard *sb)
1623 const char *buf = sb->final_buf;
1624 unsigned long len = sb->final_buf_size;
1625 const char *end = buf + len;
1626 const char *p;
1627 int *lineno;
1628 int num = 0;
1630 for (p = buf; p < end; p = get_next_line(p, end))
1631 num++;
1633 ALLOC_ARRAY(sb->lineno, num + 1);
1634 lineno = sb->lineno;
1636 for (p = buf; p < end; p = get_next_line(p, end))
1637 *lineno++ = p - buf;
1639 *lineno = len;
1641 sb->num_lines = num;
1642 return sb->num_lines;
1645 static struct commit *find_single_final(struct rev_info *revs,
1646 const char **name_p)
1648 int i;
1649 struct commit *found = NULL;
1650 const char *name = NULL;
1652 for (i = 0; i < revs->pending.nr; i++) {
1653 struct object *obj = revs->pending.objects[i].item;
1654 if (obj->flags & UNINTERESTING)
1655 continue;
1656 obj = deref_tag(obj, NULL, 0);
1657 if (obj->type != OBJ_COMMIT)
1658 die("Non commit %s?", revs->pending.objects[i].name);
1659 if (found)
1660 die("More than one commit to dig from %s and %s?",
1661 revs->pending.objects[i].name, name);
1662 found = (struct commit *)obj;
1663 name = revs->pending.objects[i].name;
1665 if (name_p)
1666 *name_p = xstrdup_or_null(name);
1667 return found;
1670 static struct commit *dwim_reverse_initial(struct rev_info *revs,
1671 const char **name_p)
1674 * DWIM "git blame --reverse ONE -- PATH" as
1675 * "git blame --reverse ONE..HEAD -- PATH" but only do so
1676 * when it makes sense.
1678 struct object *obj;
1679 struct commit *head_commit;
1680 struct object_id head_oid;
1682 if (revs->pending.nr != 1)
1683 return NULL;
1685 /* Is that sole rev a committish? */
1686 obj = revs->pending.objects[0].item;
1687 obj = deref_tag(obj, NULL, 0);
1688 if (obj->type != OBJ_COMMIT)
1689 return NULL;
1691 /* Do we have HEAD? */
1692 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
1693 return NULL;
1694 head_commit = lookup_commit_reference_gently(&head_oid, 1);
1695 if (!head_commit)
1696 return NULL;
1698 /* Turn "ONE" into "ONE..HEAD" then */
1699 obj->flags |= UNINTERESTING;
1700 add_pending_object(revs, &head_commit->object, "HEAD");
1702 if (name_p)
1703 *name_p = revs->pending.objects[0].name;
1704 return (struct commit *)obj;
1707 static struct commit *find_single_initial(struct rev_info *revs,
1708 const char **name_p)
1710 int i;
1711 struct commit *found = NULL;
1712 const char *name = NULL;
1715 * There must be one and only one negative commit, and it must be
1716 * the boundary.
1718 for (i = 0; i < revs->pending.nr; i++) {
1719 struct object *obj = revs->pending.objects[i].item;
1720 if (!(obj->flags & UNINTERESTING))
1721 continue;
1722 obj = deref_tag(obj, NULL, 0);
1723 if (obj->type != OBJ_COMMIT)
1724 die("Non commit %s?", revs->pending.objects[i].name);
1725 if (found)
1726 die("More than one commit to dig up from, %s and %s?",
1727 revs->pending.objects[i].name, name);
1728 found = (struct commit *) obj;
1729 name = revs->pending.objects[i].name;
1732 if (!name)
1733 found = dwim_reverse_initial(revs, &name);
1734 if (!name)
1735 die("No commit to dig up from?");
1737 if (name_p)
1738 *name_p = xstrdup(name);
1739 return found;
1742 void init_scoreboard(struct blame_scoreboard *sb)
1744 memset(sb, 0, sizeof(struct blame_scoreboard));
1745 sb->move_score = BLAME_DEFAULT_MOVE_SCORE;
1746 sb->copy_score = BLAME_DEFAULT_COPY_SCORE;
1749 void setup_scoreboard(struct blame_scoreboard *sb, const char *path, struct blame_origin **orig)
1751 const char *final_commit_name = NULL;
1752 struct blame_origin *o;
1753 struct commit *final_commit = NULL;
1754 enum object_type type;
1756 if (sb->reverse && sb->contents_from)
1757 die(_("--contents and --reverse do not blend well."));
1759 if (!sb->reverse) {
1760 sb->final = find_single_final(sb->revs, &final_commit_name);
1761 sb->commits.compare = compare_commits_by_commit_date;
1762 } else {
1763 sb->final = find_single_initial(sb->revs, &final_commit_name);
1764 sb->commits.compare = compare_commits_by_reverse_commit_date;
1767 if (sb->final && sb->contents_from)
1768 die(_("cannot use --contents with final commit object name"));
1770 if (sb->reverse && sb->revs->first_parent_only)
1771 sb->revs->children.name = NULL;
1773 if (!sb->final) {
1775 * "--not A B -- path" without anything positive;
1776 * do not default to HEAD, but use the working tree
1777 * or "--contents".
1779 setup_work_tree();
1780 sb->final = fake_working_tree_commit(&sb->revs->diffopt,
1781 path, sb->contents_from);
1782 add_pending_object(sb->revs, &(sb->final->object), ":");
1785 if (sb->reverse && sb->revs->first_parent_only) {
1786 final_commit = find_single_final(sb->revs, NULL);
1787 if (!final_commit)
1788 die(_("--reverse and --first-parent together require specified latest commit"));
1792 * If we have bottom, this will mark the ancestors of the
1793 * bottom commits we would reach while traversing as
1794 * uninteresting.
1796 if (prepare_revision_walk(sb->revs))
1797 die(_("revision walk setup failed"));
1799 if (sb->reverse && sb->revs->first_parent_only) {
1800 struct commit *c = final_commit;
1802 sb->revs->children.name = "children";
1803 while (c->parents &&
1804 oidcmp(&c->object.oid, &sb->final->object.oid)) {
1805 struct commit_list *l = xcalloc(1, sizeof(*l));
1807 l->item = c;
1808 if (add_decoration(&sb->revs->children,
1809 &c->parents->item->object, l))
1810 die("BUG: not unique item in first-parent chain");
1811 c = c->parents->item;
1814 if (oidcmp(&c->object.oid, &sb->final->object.oid))
1815 die(_("--reverse --first-parent together require range along first-parent chain"));
1818 if (is_null_oid(&sb->final->object.oid)) {
1819 o = sb->final->util;
1820 sb->final_buf = xmemdupz(o->file.ptr, o->file.size);
1821 sb->final_buf_size = o->file.size;
1823 else {
1824 o = get_origin(sb->final, path);
1825 if (fill_blob_sha1_and_mode(o))
1826 die(_("no such path %s in %s"), path, final_commit_name);
1828 if (sb->revs->diffopt.flags.allow_textconv &&
1829 textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
1830 &sb->final_buf_size))
1832 else
1833 sb->final_buf = read_sha1_file(o->blob_oid.hash, &type,
1834 &sb->final_buf_size);
1836 if (!sb->final_buf)
1837 die(_("cannot read blob %s for path %s"),
1838 oid_to_hex(&o->blob_oid),
1839 path);
1841 sb->num_read_blob++;
1842 prepare_lines(sb);
1844 if (orig)
1845 *orig = o;
1847 free((char *)final_commit_name);
1852 struct blame_entry *blame_entry_prepend(struct blame_entry *head,
1853 long start, long end,
1854 struct blame_origin *o)
1856 struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
1857 new_head->lno = start;
1858 new_head->num_lines = end - start;
1859 new_head->suspect = o;
1860 new_head->s_lno = start;
1861 new_head->next = head;
1862 blame_origin_incref(o);
1863 return new_head;