combine-diff.c: remove implicit dependency on the_index
[git/git.git] / blame.c
CommitLineData
072bf432
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1#include "cache.h"
2#include "refs.h"
cbd53a21 3#include "object-store.h"
072bf432 4#include "cache-tree.h"
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5#include "mergesort.h"
6#include "diff.h"
7#include "diffcore.h"
09002f1b 8#include "tag.h"
f5dd754c 9#include "blame.h"
14ba97f8 10#include "alloc.h"
4e0df4e6
NTND
11#include "commit-slab.h"
12
13define_commit_slab(blame_suspects, struct blame_origin *);
14static struct blame_suspects blame_suspects;
15
16struct blame_origin *get_blame_suspects(struct commit *commit)
17{
18 struct blame_origin **result;
19
20 result = blame_suspects_peek(&blame_suspects, commit);
21
22 return result ? *result : NULL;
23}
24
25static void set_blame_suspects(struct commit *commit, struct blame_origin *origin)
26{
27 *blame_suspects_at(&blame_suspects, commit) = origin;
28}
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29
30void blame_origin_decref(struct blame_origin *o)
31{
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 */
4e0df4e6 38 for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) {
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39 if (p == o) {
40 if (l)
41 l->next = p->next;
42 else
4e0df4e6 43 set_blame_suspects(o->commit, p->next);
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44 free(o);
45 return;
46 }
47 }
48 die("internal error in blame_origin_decref");
49 }
50}
51
52/*
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.
57 */
072bf432 58static struct blame_origin *make_origin(struct commit *commit, const char *path)
f5dd754c
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59{
60 struct blame_origin *o;
61 FLEX_ALLOC_STR(o, path, path);
62 o->commit = commit;
63 o->refcnt = 1;
4e0df4e6
NTND
64 o->next = get_blame_suspects(commit);
65 set_blame_suspects(commit, o);
f5dd754c
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66 return o;
67}
68
69/*
70 * Locate an existing origin or create a new one.
71 * This moves the origin to front position in the commit util list.
72 */
09002f1b 73static struct blame_origin *get_origin(struct commit *commit, const char *path)
f5dd754c
JS
74{
75 struct blame_origin *o, *l;
76
4e0df4e6 77 for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) {
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78 if (!strcmp(o->path, path)) {
79 /* bump to front */
80 if (l) {
81 l->next = o->next;
4e0df4e6
NTND
82 o->next = get_blame_suspects(commit);
83 set_blame_suspects(commit, o);
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84 }
85 return blame_origin_incref(o);
86 }
87 }
88 return make_origin(commit, path);
89}
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90
91
92
ecbbc0a5
NTND
93static void verify_working_tree_path(struct repository *repo,
94 struct commit *work_tree, const char *path)
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95{
96 struct commit_list *parents;
97 int pos;
98
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;
103
916bc35b 104 if (!get_tree_entry(commit_oid, path, &blob_oid, &mode) &&
ecbbc0a5 105 oid_object_info(repo, &blob_oid, NULL) == OBJ_BLOB)
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106 return;
107 }
108
ecbbc0a5 109 pos = index_name_pos(repo->index, path, strlen(path));
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110 if (pos >= 0)
111 ; /* path is in the index */
ecbbc0a5
NTND
112 else if (-1 - pos < repo->index->cache_nr &&
113 !strcmp(repo->index->cache[-1 - pos]->name, path))
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114 ; /* path is in the index, unmerged */
115 else
116 die("no such path '%s' in HEAD", path);
117}
118
119static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
120{
121 struct commit *parent;
122
2122f675 123 parent = lookup_commit_reference(the_repository, oid);
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124 if (!parent)
125 die("no such commit %s", oid_to_hex(oid));
126 return &commit_list_insert(parent, tail)->next;
127}
128
129static void append_merge_parents(struct commit_list **tail)
130{
131 int merge_head;
132 struct strbuf line = STRBUF_INIT;
133
102de880 134 merge_head = open(git_path_merge_head(the_repository), O_RDONLY);
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135 if (merge_head < 0) {
136 if (errno == ENOENT)
137 return;
102de880
SB
138 die("cannot open '%s' for reading",
139 git_path_merge_head(the_repository));
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JS
140 }
141
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))
102de880
SB
145 die("unknown line in '%s': %s",
146 git_path_merge_head(the_repository), line.buf);
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147 tail = append_parent(tail, &oid);
148 }
149 close(merge_head);
150 strbuf_release(&line);
151}
152
153/*
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).
157 */
158static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb)
159{
160 size_t len;
161 void *buf = strbuf_detach(sb, &len);
5e0c6360 162 set_commit_buffer(the_repository, c, buf, len);
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163}
164
165/*
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.
168 */
ecbbc0a5
NTND
169static struct commit *fake_working_tree_commit(struct repository *repo,
170 struct diff_options *opt,
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JS
171 const char *path,
172 const char *contents_from)
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173{
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;
a849735b 181 int len;
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182 struct cache_entry *ce;
183 unsigned mode;
184 struct strbuf msg = STRBUF_INIT;
185
ecbbc0a5 186 read_index(repo->index);
072bf432 187 time(&now);
8ba0e5ec 188 commit = alloc_commit_node(the_repository);
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189 commit->object.parsed = 1;
190 commit->date = now;
191 parent_tail = &commit->parents;
192
49e61479 193 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
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194 die("no such ref: HEAD");
195
196 parent_tail = append_parent(parent_tail, &head_oid);
197 append_merge_parents(parent_tail);
ecbbc0a5 198 verify_working_tree_path(repo, commit, path);
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199
200 origin = make_origin(commit, path);
201
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);
215
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;
221
222 if (contents_from) {
223 if (stat(contents_from, &st) < 0)
224 die_errno("Cannot stat '%s'", contents_from);
225 read_from = contents_from;
226 }
227 else {
228 if (lstat(path, &st) < 0)
229 die_errno("Cannot lstat '%s'", path);
230 read_from = path;
231 }
232 mode = canon_mode(st.st_mode);
233
234 switch (st.st_mode & S_IFMT) {
235 case S_IFREG:
0d1e0e78 236 if (opt->flags.allow_textconv &&
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JS
237 textconv_object(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);
248 }
249 }
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");
255 }
ecbbc0a5 256 convert_to_git(repo->index, path, buf.buf, buf.len, &buf, 0);
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257 origin->file.ptr = buf.buf;
258 origin->file.size = buf.len;
829e5c3b 259 pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid);
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260
261 /*
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".
266 */
ecbbc0a5
NTND
267 discard_index(repo->index);
268 read_index(repo->index);
072bf432
JS
269
270 len = strlen(path);
271 if (!mode) {
ecbbc0a5 272 int pos = index_name_pos(repo->index, path, len);
072bf432 273 if (0 <= pos)
ecbbc0a5 274 mode = repo->index->cache[pos]->ce_mode;
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JS
275 else
276 /* Let's not bother reading from HEAD tree */
277 mode = S_IFREG | 0644;
278 }
ecbbc0a5 279 ce = make_empty_cache_entry(repo->index, len);
072bf432
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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);
ecbbc0a5
NTND
285 add_index_entry(repo->index, ce,
286 ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
072bf432 287
ecbbc0a5 288 cache_tree_invalidate_path(repo->index, path);
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289
290 return commit;
291}
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292
293
294
295static 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)
297{
298 xpparam_t xpp = {0};
299 xdemitconf_t xecfg = {0};
300 xdemitcb_t ecb = {NULL};
301
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);
306}
307
308/*
309 * Given an origin, prepare mmfile_t structure to be used by the
310 * diff machinery
311 */
312static void fill_origin_blob(struct diff_options *opt,
313 struct blame_origin *o, mmfile_t *file, int *num_read_blob)
314{
315 if (!o->file.ptr) {
316 enum object_type type;
317 unsigned long file_size;
318
319 (*num_read_blob)++;
0d1e0e78 320 if (opt->flags.allow_textconv &&
b543bb1c
JS
321 textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
322 ;
323 else
b4f5aca4 324 file->ptr = read_object_file(&o->blob_oid, &type,
325 &file_size);
b543bb1c
JS
326 file->size = file_size;
327
328 if (!file->ptr)
329 die("Cannot read blob %s for path %s",
330 oid_to_hex(&o->blob_oid),
331 o->path);
332 o->file = *file;
333 }
334 else
335 *file = o->file;
336}
337
338static void drop_origin_blob(struct blame_origin *o)
339{
ce528de0 340 FREE_AND_NULL(o->file.ptr);
b543bb1c
JS
341}
342
343/*
344 * Any merge of blames happens on lists of blames that arrived via
345 * different parents in a single suspect. In this case, we want to
346 * sort according to the suspect line numbers as opposed to the final
347 * image line numbers. The function body is somewhat longish because
348 * it avoids unnecessary writes.
349 */
350
351static struct blame_entry *blame_merge(struct blame_entry *list1,
352 struct blame_entry *list2)
353{
354 struct blame_entry *p1 = list1, *p2 = list2,
355 **tail = &list1;
356
357 if (!p1)
358 return p2;
359 if (!p2)
360 return p1;
361
362 if (p1->s_lno <= p2->s_lno) {
363 do {
364 tail = &p1->next;
365 if ((p1 = *tail) == NULL) {
366 *tail = p2;
367 return list1;
368 }
369 } while (p1->s_lno <= p2->s_lno);
370 }
371 for (;;) {
372 *tail = p2;
373 do {
374 tail = &p2->next;
375 if ((p2 = *tail) == NULL) {
376 *tail = p1;
377 return list1;
378 }
379 } while (p1->s_lno > p2->s_lno);
380 *tail = p1;
381 do {
382 tail = &p1->next;
383 if ((p1 = *tail) == NULL) {
384 *tail = p2;
385 return list1;
386 }
387 } while (p1->s_lno <= p2->s_lno);
388 }
389}
390
391static void *get_next_blame(const void *p)
392{
393 return ((struct blame_entry *)p)->next;
394}
395
396static void set_next_blame(void *p1, void *p2)
397{
398 ((struct blame_entry *)p1)->next = p2;
399}
400
401/*
402 * Final image line numbers are all different, so we don't need a
403 * three-way comparison here.
404 */
405
406static int compare_blame_final(const void *p1, const void *p2)
407{
408 return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
409 ? 1 : -1;
410}
411
412static int compare_blame_suspect(const void *p1, const void *p2)
413{
414 const struct blame_entry *s1 = p1, *s2 = p2;
415 /*
416 * to allow for collating suspects, we sort according to the
417 * respective pointer value as the primary sorting criterion.
418 * The actual relation is pretty unimportant as long as it
419 * establishes a total order. Comparing as integers gives us
420 * that.
421 */
422 if (s1->suspect != s2->suspect)
423 return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
424 if (s1->s_lno == s2->s_lno)
425 return 0;
426 return s1->s_lno > s2->s_lno ? 1 : -1;
427}
428
429void blame_sort_final(struct blame_scoreboard *sb)
430{
431 sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
432 compare_blame_final);
433}
434
09002f1b
JS
435static int compare_commits_by_reverse_commit_date(const void *a,
436 const void *b,
437 void *c)
438{
439 return -compare_commits_by_commit_date(a, b, c);
440}
441
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442/*
443 * For debugging -- origin is refcounted, and this asserts that
444 * we do not underflow.
445 */
446static void sanity_check_refcnt(struct blame_scoreboard *sb)
447{
448 int baa = 0;
449 struct blame_entry *ent;
450
451 for (ent = sb->ent; ent; ent = ent->next) {
452 /* Nobody should have zero or negative refcnt */
453 if (ent->suspect->refcnt <= 0) {
454 fprintf(stderr, "%s in %s has negative refcnt %d\n",
455 ent->suspect->path,
456 oid_to_hex(&ent->suspect->commit->object.oid),
457 ent->suspect->refcnt);
458 baa = 1;
459 }
460 }
461 if (baa)
462 sb->on_sanity_fail(sb, baa);
463}
464
465/*
466 * If two blame entries that are next to each other came from
467 * contiguous lines in the same origin (i.e. <commit, path> pair),
468 * merge them together.
469 */
470void blame_coalesce(struct blame_scoreboard *sb)
471{
472 struct blame_entry *ent, *next;
473
474 for (ent = sb->ent; ent && (next = ent->next); ent = next) {
475 if (ent->suspect == next->suspect &&
476 ent->s_lno + ent->num_lines == next->s_lno) {
477 ent->num_lines += next->num_lines;
478 ent->next = next->next;
479 blame_origin_decref(next->suspect);
480 free(next);
481 ent->score = 0;
482 next = ent; /* again */
483 }
484 }
485
486 if (sb->debug) /* sanity */
487 sanity_check_refcnt(sb);
488}
489
490/*
491 * Merge the given sorted list of blames into a preexisting origin.
492 * If there were no previous blames to that commit, it is entered into
493 * the commit priority queue of the score board.
494 */
495
496static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin,
497 struct blame_entry *sorted)
498{
499 if (porigin->suspects)
500 porigin->suspects = blame_merge(porigin->suspects, sorted);
501 else {
502 struct blame_origin *o;
4e0df4e6 503 for (o = get_blame_suspects(porigin->commit); o; o = o->next) {
b543bb1c
JS
504 if (o->suspects) {
505 porigin->suspects = sorted;
506 return;
507 }
508 }
509 porigin->suspects = sorted;
510 prio_queue_put(&sb->commits, porigin->commit);
511 }
512}
513
09002f1b
JS
514/*
515 * Fill the blob_sha1 field of an origin if it hasn't, so that later
516 * call to fill_origin_blob() can use it to locate the data. blob_sha1
517 * for an origin is also used to pass the blame for the entire file to
518 * the parent to detect the case where a child's blob is identical to
519 * that of its parent's.
520 *
521 * This also fills origin->mode for corresponding tree path.
522 */
ecbbc0a5
NTND
523static int fill_blob_sha1_and_mode(struct repository *repo,
524 struct blame_origin *origin)
09002f1b
JS
525{
526 if (!is_null_oid(&origin->blob_oid))
527 return 0;
916bc35b 528 if (get_tree_entry(&origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode))
09002f1b 529 goto error_out;
ecbbc0a5 530 if (oid_object_info(repo, &origin->blob_oid, NULL) != OBJ_BLOB)
09002f1b
JS
531 goto error_out;
532 return 0;
533 error_out:
534 oidclr(&origin->blob_oid);
535 origin->mode = S_IFINVALID;
536 return -1;
537}
538
b543bb1c
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539/*
540 * We have an origin -- check if the same path exists in the
541 * parent and return an origin structure to represent it.
542 */
543static struct blame_origin *find_origin(struct commit *parent,
544 struct blame_origin *origin)
545{
546 struct blame_origin *porigin;
547 struct diff_options diff_opts;
548 const char *paths[2];
549
550 /* First check any existing origins */
4e0df4e6 551 for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next)
b543bb1c
JS
552 if (!strcmp(porigin->path, origin->path)) {
553 /*
554 * The same path between origin and its parent
555 * without renaming -- the most common case.
556 */
557 return blame_origin_incref (porigin);
558 }
559
560 /* See if the origin->path is different between parent
561 * and origin first. Most of the time they are the
562 * same and diff-tree is fairly efficient about this.
563 */
564 diff_setup(&diff_opts);
0d1e0e78 565 diff_opts.flags.recursive = 1;
b543bb1c
JS
566 diff_opts.detect_rename = 0;
567 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
568 paths[0] = origin->path;
569 paths[1] = NULL;
570
571 parse_pathspec(&diff_opts.pathspec,
572 PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
573 PATHSPEC_LITERAL_PATH, "", paths);
574 diff_setup_done(&diff_opts);
575
576 if (is_null_oid(&origin->commit->object.oid))
2e27bd77 577 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
b543bb1c 578 else
2e27bd77
DS
579 diff_tree_oid(get_commit_tree_oid(parent),
580 get_commit_tree_oid(origin->commit),
a6f38c10 581 "", &diff_opts);
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582 diffcore_std(&diff_opts);
583
584 if (!diff_queued_diff.nr) {
585 /* The path is the same as parent */
586 porigin = get_origin(parent, origin->path);
587 oidcpy(&porigin->blob_oid, &origin->blob_oid);
588 porigin->mode = origin->mode;
589 } else {
590 /*
591 * Since origin->path is a pathspec, if the parent
592 * commit had it as a directory, we will see a whole
593 * bunch of deletion of files in the directory that we
594 * do not care about.
595 */
596 int i;
597 struct diff_filepair *p = NULL;
598 for (i = 0; i < diff_queued_diff.nr; i++) {
599 const char *name;
600 p = diff_queued_diff.queue[i];
601 name = p->one->path ? p->one->path : p->two->path;
602 if (!strcmp(name, origin->path))
603 break;
604 }
605 if (!p)
606 die("internal error in blame::find_origin");
607 switch (p->status) {
608 default:
609 die("internal error in blame::find_origin (%c)",
610 p->status);
611 case 'M':
612 porigin = get_origin(parent, origin->path);
613 oidcpy(&porigin->blob_oid, &p->one->oid);
614 porigin->mode = p->one->mode;
615 break;
616 case 'A':
617 case 'T':
618 /* Did not exist in parent, or type changed */
619 break;
620 }
621 }
622 diff_flush(&diff_opts);
623 clear_pathspec(&diff_opts.pathspec);
624 return porigin;
625}
626
627/*
628 * We have an origin -- find the path that corresponds to it in its
629 * parent and return an origin structure to represent it.
630 */
631static struct blame_origin *find_rename(struct commit *parent,
632 struct blame_origin *origin)
633{
634 struct blame_origin *porigin = NULL;
635 struct diff_options diff_opts;
636 int i;
637
638 diff_setup(&diff_opts);
0d1e0e78 639 diff_opts.flags.recursive = 1;
b543bb1c
JS
640 diff_opts.detect_rename = DIFF_DETECT_RENAME;
641 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
642 diff_opts.single_follow = origin->path;
643 diff_setup_done(&diff_opts);
644
645 if (is_null_oid(&origin->commit->object.oid))
2e27bd77 646 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
b543bb1c 647 else
2e27bd77
DS
648 diff_tree_oid(get_commit_tree_oid(parent),
649 get_commit_tree_oid(origin->commit),
a6f38c10 650 "", &diff_opts);
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651 diffcore_std(&diff_opts);
652
653 for (i = 0; i < diff_queued_diff.nr; i++) {
654 struct diff_filepair *p = diff_queued_diff.queue[i];
655 if ((p->status == 'R' || p->status == 'C') &&
656 !strcmp(p->two->path, origin->path)) {
657 porigin = get_origin(parent, p->one->path);
658 oidcpy(&porigin->blob_oid, &p->one->oid);
659 porigin->mode = p->one->mode;
660 break;
661 }
662 }
663 diff_flush(&diff_opts);
664 clear_pathspec(&diff_opts.pathspec);
665 return porigin;
666}
667
668/*
669 * Append a new blame entry to a given output queue.
670 */
671static void add_blame_entry(struct blame_entry ***queue,
672 const struct blame_entry *src)
673{
674 struct blame_entry *e = xmalloc(sizeof(*e));
675 memcpy(e, src, sizeof(*e));
676 blame_origin_incref(e->suspect);
677
678 e->next = **queue;
679 **queue = e;
680 *queue = &e->next;
681}
682
683/*
684 * src typically is on-stack; we want to copy the information in it to
685 * a malloced blame_entry that gets added to the given queue. The
686 * origin of dst loses a refcnt.
687 */
688static void dup_entry(struct blame_entry ***queue,
689 struct blame_entry *dst, struct blame_entry *src)
690{
691 blame_origin_incref(src->suspect);
692 blame_origin_decref(dst->suspect);
693 memcpy(dst, src, sizeof(*src));
694 dst->next = **queue;
695 **queue = dst;
696 *queue = &dst->next;
697}
698
699const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
700{
701 return sb->final_buf + sb->lineno[lno];
702}
703
704/*
705 * It is known that lines between tlno to same came from parent, and e
706 * has an overlap with that range. it also is known that parent's
707 * line plno corresponds to e's line tlno.
708 *
709 * <---- e ----->
710 * <------>
711 * <------------>
712 * <------------>
713 * <------------------>
714 *
715 * Split e into potentially three parts; before this chunk, the chunk
716 * to be blamed for the parent, and after that portion.
717 */
718static void split_overlap(struct blame_entry *split,
719 struct blame_entry *e,
720 int tlno, int plno, int same,
721 struct blame_origin *parent)
722{
723 int chunk_end_lno;
724 memset(split, 0, sizeof(struct blame_entry [3]));
725
726 if (e->s_lno < tlno) {
727 /* there is a pre-chunk part not blamed on parent */
728 split[0].suspect = blame_origin_incref(e->suspect);
729 split[0].lno = e->lno;
730 split[0].s_lno = e->s_lno;
731 split[0].num_lines = tlno - e->s_lno;
732 split[1].lno = e->lno + tlno - e->s_lno;
733 split[1].s_lno = plno;
734 }
735 else {
736 split[1].lno = e->lno;
737 split[1].s_lno = plno + (e->s_lno - tlno);
738 }
739
740 if (same < e->s_lno + e->num_lines) {
741 /* there is a post-chunk part not blamed on parent */
742 split[2].suspect = blame_origin_incref(e->suspect);
743 split[2].lno = e->lno + (same - e->s_lno);
744 split[2].s_lno = e->s_lno + (same - e->s_lno);
745 split[2].num_lines = e->s_lno + e->num_lines - same;
746 chunk_end_lno = split[2].lno;
747 }
748 else
749 chunk_end_lno = e->lno + e->num_lines;
750 split[1].num_lines = chunk_end_lno - split[1].lno;
751
752 /*
753 * if it turns out there is nothing to blame the parent for,
754 * forget about the splitting. !split[1].suspect signals this.
755 */
756 if (split[1].num_lines < 1)
757 return;
758 split[1].suspect = blame_origin_incref(parent);
759}
760
761/*
762 * split_overlap() divided an existing blame e into up to three parts
763 * in split. Any assigned blame is moved to queue to
764 * reflect the split.
765 */
766static void split_blame(struct blame_entry ***blamed,
767 struct blame_entry ***unblamed,
768 struct blame_entry *split,
769 struct blame_entry *e)
770{
771 if (split[0].suspect && split[2].suspect) {
772 /* The first part (reuse storage for the existing entry e) */
773 dup_entry(unblamed, e, &split[0]);
774
775 /* The last part -- me */
776 add_blame_entry(unblamed, &split[2]);
777
778 /* ... and the middle part -- parent */
779 add_blame_entry(blamed, &split[1]);
780 }
781 else if (!split[0].suspect && !split[2].suspect)
782 /*
783 * The parent covers the entire area; reuse storage for
784 * e and replace it with the parent.
785 */
786 dup_entry(blamed, e, &split[1]);
787 else if (split[0].suspect) {
788 /* me and then parent */
789 dup_entry(unblamed, e, &split[0]);
790 add_blame_entry(blamed, &split[1]);
791 }
792 else {
793 /* parent and then me */
794 dup_entry(blamed, e, &split[1]);
795 add_blame_entry(unblamed, &split[2]);
796 }
797}
798
799/*
800 * After splitting the blame, the origins used by the
801 * on-stack blame_entry should lose one refcnt each.
802 */
803static void decref_split(struct blame_entry *split)
804{
805 int i;
806
807 for (i = 0; i < 3; i++)
808 blame_origin_decref(split[i].suspect);
809}
810
811/*
812 * reverse_blame reverses the list given in head, appending tail.
813 * That allows us to build lists in reverse order, then reverse them
814 * afterwards. This can be faster than building the list in proper
815 * order right away. The reason is that building in proper order
816 * requires writing a link in the _previous_ element, while building
817 * in reverse order just requires placing the list head into the
818 * _current_ element.
819 */
820
821static struct blame_entry *reverse_blame(struct blame_entry *head,
822 struct blame_entry *tail)
823{
824 while (head) {
825 struct blame_entry *next = head->next;
826 head->next = tail;
827 tail = head;
828 head = next;
829 }
830 return tail;
831}
832
833/*
834 * Process one hunk from the patch between the current suspect for
835 * blame_entry e and its parent. This first blames any unfinished
836 * entries before the chunk (which is where target and parent start
837 * differing) on the parent, and then splits blame entries at the
838 * start and at the end of the difference region. Since use of -M and
839 * -C options may lead to overlapping/duplicate source line number
840 * ranges, all we can rely on from sorting/merging is the order of the
841 * first suspect line number.
842 */
843static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
844 int tlno, int offset, int same,
845 struct blame_origin *parent)
846{
847 struct blame_entry *e = **srcq;
848 struct blame_entry *samep = NULL, *diffp = NULL;
849
850 while (e && e->s_lno < tlno) {
851 struct blame_entry *next = e->next;
852 /*
853 * current record starts before differing portion. If
854 * it reaches into it, we need to split it up and
855 * examine the second part separately.
856 */
857 if (e->s_lno + e->num_lines > tlno) {
858 /* Move second half to a new record */
859 int len = tlno - e->s_lno;
860 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
861 n->suspect = e->suspect;
862 n->lno = e->lno + len;
863 n->s_lno = e->s_lno + len;
864 n->num_lines = e->num_lines - len;
865 e->num_lines = len;
866 e->score = 0;
867 /* Push new record to diffp */
868 n->next = diffp;
869 diffp = n;
870 } else
871 blame_origin_decref(e->suspect);
872 /* Pass blame for everything before the differing
873 * chunk to the parent */
874 e->suspect = blame_origin_incref(parent);
875 e->s_lno += offset;
876 e->next = samep;
877 samep = e;
878 e = next;
879 }
880 /*
881 * As we don't know how much of a common stretch after this
882 * diff will occur, the currently blamed parts are all that we
883 * can assign to the parent for now.
884 */
885
886 if (samep) {
887 **dstq = reverse_blame(samep, **dstq);
888 *dstq = &samep->next;
889 }
890 /*
891 * Prepend the split off portions: everything after e starts
892 * after the blameable portion.
893 */
894 e = reverse_blame(diffp, e);
895
896 /*
897 * Now retain records on the target while parts are different
898 * from the parent.
899 */
900 samep = NULL;
901 diffp = NULL;
902 while (e && e->s_lno < same) {
903 struct blame_entry *next = e->next;
904
905 /*
906 * If current record extends into sameness, need to split.
907 */
908 if (e->s_lno + e->num_lines > same) {
909 /*
910 * Move second half to a new record to be
911 * processed by later chunks
912 */
913 int len = same - e->s_lno;
914 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
915 n->suspect = blame_origin_incref(e->suspect);
916 n->lno = e->lno + len;
917 n->s_lno = e->s_lno + len;
918 n->num_lines = e->num_lines - len;
919 e->num_lines = len;
920 e->score = 0;
921 /* Push new record to samep */
922 n->next = samep;
923 samep = n;
924 }
925 e->next = diffp;
926 diffp = e;
927 e = next;
928 }
929 **srcq = reverse_blame(diffp, reverse_blame(samep, e));
930 /* Move across elements that are in the unblamable portion */
931 if (diffp)
932 *srcq = &diffp->next;
933}
934
935struct blame_chunk_cb_data {
936 struct blame_origin *parent;
937 long offset;
938 struct blame_entry **dstq;
939 struct blame_entry **srcq;
940};
941
942/* diff chunks are from parent to target */
943static int blame_chunk_cb(long start_a, long count_a,
944 long start_b, long count_b, void *data)
945{
946 struct blame_chunk_cb_data *d = data;
947 if (start_a - start_b != d->offset)
948 die("internal error in blame::blame_chunk_cb");
949 blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
950 start_b + count_b, d->parent);
951 d->offset = start_a + count_a - (start_b + count_b);
952 return 0;
953}
954
955/*
956 * We are looking at the origin 'target' and aiming to pass blame
957 * for the lines it is suspected to its parent. Run diff to find
958 * which lines came from parent and pass blame for them.
959 */
960static void pass_blame_to_parent(struct blame_scoreboard *sb,
961 struct blame_origin *target,
962 struct blame_origin *parent)
963{
964 mmfile_t file_p, file_o;
965 struct blame_chunk_cb_data d;
966 struct blame_entry *newdest = NULL;
967
968 if (!target->suspects)
969 return; /* nothing remains for this target */
970
971 d.parent = parent;
972 d.offset = 0;
973 d.dstq = &newdest; d.srcq = &target->suspects;
974
975 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
976 fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
977 sb->num_get_patch++;
978
979 if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
980 die("unable to generate diff (%s -> %s)",
981 oid_to_hex(&parent->commit->object.oid),
982 oid_to_hex(&target->commit->object.oid));
983 /* The rest are the same as the parent */
984 blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
985 *d.dstq = NULL;
986 queue_blames(sb, parent, newdest);
987
988 return;
989}
990
991/*
992 * The lines in blame_entry after splitting blames many times can become
993 * very small and trivial, and at some point it becomes pointless to
994 * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any
995 * ordinary C program, and it is not worth to say it was copied from
996 * totally unrelated file in the parent.
997 *
998 * Compute how trivial the lines in the blame_entry are.
999 */
1000unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
1001{
1002 unsigned score;
1003 const char *cp, *ep;
1004
1005 if (e->score)
1006 return e->score;
1007
1008 score = 1;
1009 cp = blame_nth_line(sb, e->lno);
1010 ep = blame_nth_line(sb, e->lno + e->num_lines);
1011 while (cp < ep) {
1012 unsigned ch = *((unsigned char *)cp);
1013 if (isalnum(ch))
1014 score++;
1015 cp++;
1016 }
1017 e->score = score;
1018 return score;
1019}
1020
1021/*
abeacb25
BW
1022 * best_so_far[] and potential[] are both a split of an existing blame_entry
1023 * that passes blame to the parent. Maintain best_so_far the best split so
1024 * far, by comparing potential and best_so_far and copying potential into
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1025 * bst_so_far as needed.
1026 */
1027static void copy_split_if_better(struct blame_scoreboard *sb,
1028 struct blame_entry *best_so_far,
abeacb25 1029 struct blame_entry *potential)
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1030{
1031 int i;
1032
abeacb25 1033 if (!potential[1].suspect)
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1034 return;
1035 if (best_so_far[1].suspect) {
abeacb25
BW
1036 if (blame_entry_score(sb, &potential[1]) <
1037 blame_entry_score(sb, &best_so_far[1]))
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1038 return;
1039 }
1040
1041 for (i = 0; i < 3; i++)
abeacb25 1042 blame_origin_incref(potential[i].suspect);
b543bb1c 1043 decref_split(best_so_far);
abeacb25 1044 memcpy(best_so_far, potential, sizeof(struct blame_entry[3]));
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JS
1045}
1046
1047/*
1048 * We are looking at a part of the final image represented by
1049 * ent (tlno and same are offset by ent->s_lno).
1050 * tlno is where we are looking at in the final image.
1051 * up to (but not including) same match preimage.
1052 * plno is where we are looking at in the preimage.
1053 *
1054 * <-------------- final image ---------------------->
1055 * <------ent------>
1056 * ^tlno ^same
1057 * <---------preimage----->
1058 * ^plno
1059 *
1060 * All line numbers are 0-based.
1061 */
1062static void handle_split(struct blame_scoreboard *sb,
1063 struct blame_entry *ent,
1064 int tlno, int plno, int same,
1065 struct blame_origin *parent,
1066 struct blame_entry *split)
1067{
1068 if (ent->num_lines <= tlno)
1069 return;
1070 if (tlno < same) {
abeacb25 1071 struct blame_entry potential[3];
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1072 tlno += ent->s_lno;
1073 same += ent->s_lno;
abeacb25
BW
1074 split_overlap(potential, ent, tlno, plno, same, parent);
1075 copy_split_if_better(sb, split, potential);
1076 decref_split(potential);
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JS
1077 }
1078}
1079
1080struct handle_split_cb_data {
1081 struct blame_scoreboard *sb;
1082 struct blame_entry *ent;
1083 struct blame_origin *parent;
1084 struct blame_entry *split;
1085 long plno;
1086 long tlno;
1087};
1088
1089static int handle_split_cb(long start_a, long count_a,
1090 long start_b, long count_b, void *data)
1091{
1092 struct handle_split_cb_data *d = data;
1093 handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
1094 d->split);
1095 d->plno = start_a + count_a;
1096 d->tlno = start_b + count_b;
1097 return 0;
1098}
1099
1100/*
1101 * Find the lines from parent that are the same as ent so that
1102 * we can pass blames to it. file_p has the blob contents for
1103 * the parent.
1104 */
1105static void find_copy_in_blob(struct blame_scoreboard *sb,
1106 struct blame_entry *ent,
1107 struct blame_origin *parent,
1108 struct blame_entry *split,
1109 mmfile_t *file_p)
1110{
1111 const char *cp;
1112 mmfile_t file_o;
1113 struct handle_split_cb_data d;
1114
1115 memset(&d, 0, sizeof(d));
1116 d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
1117 /*
1118 * Prepare mmfile that contains only the lines in ent.
1119 */
1120 cp = blame_nth_line(sb, ent->lno);
1121 file_o.ptr = (char *) cp;
1122 file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
1123
1124 /*
1125 * file_o is a part of final image we are annotating.
1126 * file_p partially may match that image.
1127 */
1128 memset(split, 0, sizeof(struct blame_entry [3]));
1129 if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
1130 die("unable to generate diff (%s)",
1131 oid_to_hex(&parent->commit->object.oid));
1132 /* remainder, if any, all match the preimage */
1133 handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
1134}
1135
1136/* Move all blame entries from list *source that have a score smaller
1137 * than score_min to the front of list *small.
1138 * Returns a pointer to the link pointing to the old head of the small list.
1139 */
1140
1141static struct blame_entry **filter_small(struct blame_scoreboard *sb,
1142 struct blame_entry **small,
1143 struct blame_entry **source,
1144 unsigned score_min)
1145{
1146 struct blame_entry *p = *source;
1147 struct blame_entry *oldsmall = *small;
1148 while (p) {
1149 if (blame_entry_score(sb, p) <= score_min) {
1150 *small = p;
1151 small = &p->next;
1152 p = *small;
1153 } else {
1154 *source = p;
1155 source = &p->next;
1156 p = *source;
1157 }
1158 }
1159 *small = oldsmall;
1160 *source = NULL;
1161 return small;
1162}
1163
1164/*
1165 * See if lines currently target is suspected for can be attributed to
1166 * parent.
1167 */
1168static void find_move_in_parent(struct blame_scoreboard *sb,
1169 struct blame_entry ***blamed,
1170 struct blame_entry **toosmall,
1171 struct blame_origin *target,
1172 struct blame_origin *parent)
1173{
1174 struct blame_entry *e, split[3];
1175 struct blame_entry *unblamed = target->suspects;
1176 struct blame_entry *leftover = NULL;
1177 mmfile_t file_p;
1178
1179 if (!unblamed)
1180 return; /* nothing remains for this target */
1181
1182 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
1183 if (!file_p.ptr)
1184 return;
1185
1186 /* At each iteration, unblamed has a NULL-terminated list of
1187 * entries that have not yet been tested for blame. leftover
1188 * contains the reversed list of entries that have been tested
1189 * without being assignable to the parent.
1190 */
1191 do {
1192 struct blame_entry **unblamedtail = &unblamed;
1193 struct blame_entry *next;
1194 for (e = unblamed; e; e = next) {
1195 next = e->next;
1196 find_copy_in_blob(sb, e, parent, split, &file_p);
1197 if (split[1].suspect &&
1198 sb->move_score < blame_entry_score(sb, &split[1])) {
1199 split_blame(blamed, &unblamedtail, split, e);
1200 } else {
1201 e->next = leftover;
1202 leftover = e;
1203 }
1204 decref_split(split);
1205 }
1206 *unblamedtail = NULL;
1207 toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);
1208 } while (unblamed);
1209 target->suspects = reverse_blame(leftover, NULL);
1210}
1211
1212struct blame_list {
1213 struct blame_entry *ent;
1214 struct blame_entry split[3];
1215};
1216
1217/*
1218 * Count the number of entries the target is suspected for,
1219 * and prepare a list of entry and the best split.
1220 */
1221static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
1222 int *num_ents_p)
1223{
1224 struct blame_entry *e;
1225 int num_ents, i;
1226 struct blame_list *blame_list = NULL;
1227
1228 for (e = unblamed, num_ents = 0; e; e = e->next)
1229 num_ents++;
1230 if (num_ents) {
1231 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1232 for (e = unblamed, i = 0; e; e = e->next)
1233 blame_list[i++].ent = e;
1234 }
1235 *num_ents_p = num_ents;
1236 return blame_list;
1237}
1238
1239/*
1240 * For lines target is suspected for, see if we can find code movement
1241 * across file boundary from the parent commit. porigin is the path
1242 * in the parent we already tried.
1243 */
1244static void find_copy_in_parent(struct blame_scoreboard *sb,
1245 struct blame_entry ***blamed,
1246 struct blame_entry **toosmall,
1247 struct blame_origin *target,
1248 struct commit *parent,
1249 struct blame_origin *porigin,
1250 int opt)
1251{
1252 struct diff_options diff_opts;
1253 int i, j;
1254 struct blame_list *blame_list;
1255 int num_ents;
1256 struct blame_entry *unblamed = target->suspects;
1257 struct blame_entry *leftover = NULL;
1258
1259 if (!unblamed)
1260 return; /* nothing remains for this target */
1261
1262 diff_setup(&diff_opts);
0d1e0e78 1263 diff_opts.flags.recursive = 1;
b543bb1c
JS
1264 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1265
1266 diff_setup_done(&diff_opts);
1267
1268 /* Try "find copies harder" on new path if requested;
1269 * we do not want to use diffcore_rename() actually to
1270 * match things up; find_copies_harder is set only to
a6f38c10 1271 * force diff_tree_oid() to feed all filepairs to diff_queue,
b543bb1c
JS
1272 * and this code needs to be after diff_setup_done(), which
1273 * usually makes find-copies-harder imply copy detection.
1274 */
1275 if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1276 || ((opt & PICKAXE_BLAME_COPY_HARDER)
1277 && (!porigin || strcmp(target->path, porigin->path))))
0d1e0e78 1278 diff_opts.flags.find_copies_harder = 1;
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JS
1279
1280 if (is_null_oid(&target->commit->object.oid))
2e27bd77 1281 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
b543bb1c 1282 else
2e27bd77
DS
1283 diff_tree_oid(get_commit_tree_oid(parent),
1284 get_commit_tree_oid(target->commit),
a6f38c10 1285 "", &diff_opts);
b543bb1c 1286
0d1e0e78 1287 if (!diff_opts.flags.find_copies_harder)
b543bb1c
JS
1288 diffcore_std(&diff_opts);
1289
1290 do {
1291 struct blame_entry **unblamedtail = &unblamed;
1292 blame_list = setup_blame_list(unblamed, &num_ents);
1293
1294 for (i = 0; i < diff_queued_diff.nr; i++) {
1295 struct diff_filepair *p = diff_queued_diff.queue[i];
1296 struct blame_origin *norigin;
1297 mmfile_t file_p;
abeacb25 1298 struct blame_entry potential[3];
b543bb1c
JS
1299
1300 if (!DIFF_FILE_VALID(p->one))
1301 continue; /* does not exist in parent */
1302 if (S_ISGITLINK(p->one->mode))
1303 continue; /* ignore git links */
1304 if (porigin && !strcmp(p->one->path, porigin->path))
1305 /* find_move already dealt with this path */
1306 continue;
1307
1308 norigin = get_origin(parent, p->one->path);
1309 oidcpy(&norigin->blob_oid, &p->one->oid);
1310 norigin->mode = p->one->mode;
1311 fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
1312 if (!file_p.ptr)
1313 continue;
1314
1315 for (j = 0; j < num_ents; j++) {
1316 find_copy_in_blob(sb, blame_list[j].ent,
abeacb25 1317 norigin, potential, &file_p);
b543bb1c 1318 copy_split_if_better(sb, blame_list[j].split,
abeacb25
BW
1319 potential);
1320 decref_split(potential);
b543bb1c
JS
1321 }
1322 blame_origin_decref(norigin);
1323 }
1324
1325 for (j = 0; j < num_ents; j++) {
1326 struct blame_entry *split = blame_list[j].split;
1327 if (split[1].suspect &&
1328 sb->copy_score < blame_entry_score(sb, &split[1])) {
1329 split_blame(blamed, &unblamedtail, split,
1330 blame_list[j].ent);
1331 } else {
1332 blame_list[j].ent->next = leftover;
1333 leftover = blame_list[j].ent;
1334 }
1335 decref_split(split);
1336 }
1337 free(blame_list);
1338 *unblamedtail = NULL;
1339 toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);
1340 } while (unblamed);
1341 target->suspects = reverse_blame(leftover, NULL);
1342 diff_flush(&diff_opts);
1343 clear_pathspec(&diff_opts.pathspec);
1344}
1345
1346/*
1347 * The blobs of origin and porigin exactly match, so everything
1348 * origin is suspected for can be blamed on the parent.
1349 */
1350static void pass_whole_blame(struct blame_scoreboard *sb,
1351 struct blame_origin *origin, struct blame_origin *porigin)
1352{
1353 struct blame_entry *e, *suspects;
1354
1355 if (!porigin->file.ptr && origin->file.ptr) {
1356 /* Steal its file */
1357 porigin->file = origin->file;
1358 origin->file.ptr = NULL;
1359 }
1360 suspects = origin->suspects;
1361 origin->suspects = NULL;
1362 for (e = suspects; e; e = e->next) {
1363 blame_origin_incref(porigin);
1364 blame_origin_decref(e->suspect);
1365 e->suspect = porigin;
1366 }
1367 queue_blames(sb, porigin, suspects);
1368}
1369
1370/*
1371 * We pass blame from the current commit to its parents. We keep saying
1372 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1373 * exonerate ourselves.
1374 */
1375static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,
1376 int reverse)
1377{
1378 if (!reverse) {
1379 if (revs->first_parent_only &&
1380 commit->parents &&
1381 commit->parents->next) {
1382 free_commit_list(commit->parents->next);
1383 commit->parents->next = NULL;
1384 }
1385 return commit->parents;
1386 }
1387 return lookup_decoration(&revs->children, &commit->object);
1388}
1389
1390static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)
1391{
1392 struct commit_list *l = first_scapegoat(revs, commit, reverse);
1393 return commit_list_count(l);
1394}
1395
1396/* Distribute collected unsorted blames to the respected sorted lists
1397 * in the various origins.
1398 */
1399static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)
1400{
1401 blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
1402 compare_blame_suspect);
1403 while (blamed)
1404 {
1405 struct blame_origin *porigin = blamed->suspect;
1406 struct blame_entry *suspects = NULL;
1407 do {
1408 struct blame_entry *next = blamed->next;
1409 blamed->next = suspects;
1410 suspects = blamed;
1411 blamed = next;
1412 } while (blamed && blamed->suspect == porigin);
1413 suspects = reverse_blame(suspects, NULL);
1414 queue_blames(sb, porigin, suspects);
1415 }
1416}
1417
1418#define MAXSG 16
1419
1420static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)
1421{
1422 struct rev_info *revs = sb->revs;
1423 int i, pass, num_sg;
1424 struct commit *commit = origin->commit;
1425 struct commit_list *sg;
1426 struct blame_origin *sg_buf[MAXSG];
1427 struct blame_origin *porigin, **sg_origin = sg_buf;
1428 struct blame_entry *toosmall = NULL;
1429 struct blame_entry *blames, **blametail = &blames;
1430
1431 num_sg = num_scapegoats(revs, commit, sb->reverse);
1432 if (!num_sg)
1433 goto finish;
1434 else if (num_sg < ARRAY_SIZE(sg_buf))
1435 memset(sg_buf, 0, sizeof(sg_buf));
1436 else
1437 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1438
1439 /*
1440 * The first pass looks for unrenamed path to optimize for
1441 * common cases, then we look for renames in the second pass.
1442 */
1443 for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
1444 struct blame_origin *(*find)(struct commit *, struct blame_origin *);
1445 find = pass ? find_rename : find_origin;
1446
1447 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1448 i < num_sg && sg;
1449 sg = sg->next, i++) {
1450 struct commit *p = sg->item;
1451 int j, same;
1452
1453 if (sg_origin[i])
1454 continue;
1455 if (parse_commit(p))
1456 continue;
1457 porigin = find(p, origin);
1458 if (!porigin)
1459 continue;
1460 if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
1461 pass_whole_blame(sb, origin, porigin);
1462 blame_origin_decref(porigin);
1463 goto finish;
1464 }
1465 for (j = same = 0; j < i; j++)
1466 if (sg_origin[j] &&
1467 !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
1468 same = 1;
1469 break;
1470 }
1471 if (!same)
1472 sg_origin[i] = porigin;
1473 else
1474 blame_origin_decref(porigin);
1475 }
1476 }
1477
1478 sb->num_commits++;
1479 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1480 i < num_sg && sg;
1481 sg = sg->next, i++) {
1482 struct blame_origin *porigin = sg_origin[i];
1483 if (!porigin)
1484 continue;
1485 if (!origin->previous) {
1486 blame_origin_incref(porigin);
1487 origin->previous = porigin;
1488 }
1489 pass_blame_to_parent(sb, origin, porigin);
1490 if (!origin->suspects)
1491 goto finish;
1492 }
1493
1494 /*
1495 * Optionally find moves in parents' files.
1496 */
1497 if (opt & PICKAXE_BLAME_MOVE) {
1498 filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
1499 if (origin->suspects) {
1500 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1501 i < num_sg && sg;
1502 sg = sg->next, i++) {
1503 struct blame_origin *porigin = sg_origin[i];
1504 if (!porigin)
1505 continue;
1506 find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
1507 if (!origin->suspects)
1508 break;
1509 }
1510 }
1511 }
1512
1513 /*
1514 * Optionally find copies from parents' files.
1515 */
1516 if (opt & PICKAXE_BLAME_COPY) {
1517 if (sb->copy_score > sb->move_score)
1518 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1519 else if (sb->copy_score < sb->move_score) {
1520 origin->suspects = blame_merge(origin->suspects, toosmall);
1521 toosmall = NULL;
1522 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
1523 }
1524 if (!origin->suspects)
1525 goto finish;
1526
1527 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
1528 i < num_sg && sg;
1529 sg = sg->next, i++) {
1530 struct blame_origin *porigin = sg_origin[i];
1531 find_copy_in_parent(sb, &blametail, &toosmall,
1532 origin, sg->item, porigin, opt);
1533 if (!origin->suspects)
1534 goto finish;
1535 }
1536 }
1537
1538finish:
1539 *blametail = NULL;
1540 distribute_blame(sb, blames);
1541 /*
1542 * prepend toosmall to origin->suspects
1543 *
1544 * There is no point in sorting: this ends up on a big
1545 * unsorted list in the caller anyway.
1546 */
1547 if (toosmall) {
1548 struct blame_entry **tail = &toosmall;
1549 while (*tail)
1550 tail = &(*tail)->next;
1551 *tail = origin->suspects;
1552 origin->suspects = toosmall;
1553 }
1554 for (i = 0; i < num_sg; i++) {
1555 if (sg_origin[i]) {
1556 drop_origin_blob(sg_origin[i]);
1557 blame_origin_decref(sg_origin[i]);
1558 }
1559 }
1560 drop_origin_blob(origin);
1561 if (sg_buf != sg_origin)
1562 free(sg_origin);
1563}
1564
1565/*
1566 * The main loop -- while we have blobs with lines whose true origin
1567 * is still unknown, pick one blob, and allow its lines to pass blames
1568 * to its parents. */
1569void assign_blame(struct blame_scoreboard *sb, int opt)
1570{
1571 struct rev_info *revs = sb->revs;
1572 struct commit *commit = prio_queue_get(&sb->commits);
1573
1574 while (commit) {
1575 struct blame_entry *ent;
4e0df4e6 1576 struct blame_origin *suspect = get_blame_suspects(commit);
b543bb1c
JS
1577
1578 /* find one suspect to break down */
1579 while (suspect && !suspect->suspects)
1580 suspect = suspect->next;
1581
1582 if (!suspect) {
1583 commit = prio_queue_get(&sb->commits);
1584 continue;
1585 }
1586
1587 assert(commit == suspect->commit);
1588
1589 /*
1590 * We will use this suspect later in the loop,
1591 * so hold onto it in the meantime.
1592 */
1593 blame_origin_incref(suspect);
1594 parse_commit(commit);
1595 if (sb->reverse ||
1596 (!(commit->object.flags & UNINTERESTING) &&
1597 !(revs->max_age != -1 && commit->date < revs->max_age)))
1598 pass_blame(sb, suspect, opt);
1599 else {
1600 commit->object.flags |= UNINTERESTING;
1601 if (commit->object.parsed)
1602 mark_parents_uninteresting(commit);
1603 }
1604 /* treat root commit as boundary */
1605 if (!commit->parents && !sb->show_root)
1606 commit->object.flags |= UNINTERESTING;
1607
1608 /* Take responsibility for the remaining entries */
1609 ent = suspect->suspects;
1610 if (ent) {
1611 suspect->guilty = 1;
1612 for (;;) {
1613 struct blame_entry *next = ent->next;
1614 if (sb->found_guilty_entry)
1615 sb->found_guilty_entry(ent, sb->found_guilty_entry_data);
1616 if (next) {
1617 ent = next;
1618 continue;
1619 }
1620 ent->next = sb->ent;
1621 sb->ent = suspect->suspects;
1622 suspect->suspects = NULL;
1623 break;
1624 }
1625 }
1626 blame_origin_decref(suspect);
1627
1628 if (sb->debug) /* sanity */
1629 sanity_check_refcnt(sb);
1630 }
1631}
09002f1b
JS
1632
1633static const char *get_next_line(const char *start, const char *end)
1634{
1635 const char *nl = memchr(start, '\n', end - start);
1636 return nl ? nl + 1 : end;
1637}
1638
1639/*
1640 * To allow quick access to the contents of nth line in the
1641 * final image, prepare an index in the scoreboard.
1642 */
1643static int prepare_lines(struct blame_scoreboard *sb)
1644{
1645 const char *buf = sb->final_buf;
1646 unsigned long len = sb->final_buf_size;
1647 const char *end = buf + len;
1648 const char *p;
1649 int *lineno;
1650 int num = 0;
1651
1652 for (p = buf; p < end; p = get_next_line(p, end))
1653 num++;
1654
1655 ALLOC_ARRAY(sb->lineno, num + 1);
1656 lineno = sb->lineno;
1657
1658 for (p = buf; p < end; p = get_next_line(p, end))
1659 *lineno++ = p - buf;
1660
1661 *lineno = len;
1662
1663 sb->num_lines = num;
1664 return sb->num_lines;
1665}
1666
1667static struct commit *find_single_final(struct rev_info *revs,
1668 const char **name_p)
1669{
1670 int i;
1671 struct commit *found = NULL;
1672 const char *name = NULL;
1673
1674 for (i = 0; i < revs->pending.nr; i++) {
1675 struct object *obj = revs->pending.objects[i].item;
1676 if (obj->flags & UNINTERESTING)
1677 continue;
a74093da 1678 obj = deref_tag(the_repository, obj, NULL, 0);
09002f1b
JS
1679 if (obj->type != OBJ_COMMIT)
1680 die("Non commit %s?", revs->pending.objects[i].name);
1681 if (found)
1682 die("More than one commit to dig from %s and %s?",
1683 revs->pending.objects[i].name, name);
1684 found = (struct commit *)obj;
1685 name = revs->pending.objects[i].name;
1686 }
1687 if (name_p)
9e7d8a9b 1688 *name_p = xstrdup_or_null(name);
09002f1b
JS
1689 return found;
1690}
1691
1692static struct commit *dwim_reverse_initial(struct rev_info *revs,
1693 const char **name_p)
1694{
1695 /*
1696 * DWIM "git blame --reverse ONE -- PATH" as
1697 * "git blame --reverse ONE..HEAD -- PATH" but only do so
1698 * when it makes sense.
1699 */
1700 struct object *obj;
1701 struct commit *head_commit;
583c6a22 1702 struct object_id head_oid;
09002f1b
JS
1703
1704 if (revs->pending.nr != 1)
1705 return NULL;
1706
1707 /* Is that sole rev a committish? */
1708 obj = revs->pending.objects[0].item;
a74093da 1709 obj = deref_tag(the_repository, obj, NULL, 0);
09002f1b
JS
1710 if (obj->type != OBJ_COMMIT)
1711 return NULL;
1712
1713 /* Do we have HEAD? */
49e61479 1714 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
09002f1b 1715 return NULL;
21e1ee8f
SB
1716 head_commit = lookup_commit_reference_gently(the_repository,
1717 &head_oid, 1);
09002f1b
JS
1718 if (!head_commit)
1719 return NULL;
1720
1721 /* Turn "ONE" into "ONE..HEAD" then */
1722 obj->flags |= UNINTERESTING;
1723 add_pending_object(revs, &head_commit->object, "HEAD");
1724
1725 if (name_p)
1726 *name_p = revs->pending.objects[0].name;
1727 return (struct commit *)obj;
1728}
1729
1730static struct commit *find_single_initial(struct rev_info *revs,
1731 const char **name_p)
1732{
1733 int i;
1734 struct commit *found = NULL;
1735 const char *name = NULL;
1736
1737 /*
1738 * There must be one and only one negative commit, and it must be
1739 * the boundary.
1740 */
1741 for (i = 0; i < revs->pending.nr; i++) {
1742 struct object *obj = revs->pending.objects[i].item;
1743 if (!(obj->flags & UNINTERESTING))
1744 continue;
a74093da 1745 obj = deref_tag(the_repository, obj, NULL, 0);
09002f1b
JS
1746 if (obj->type != OBJ_COMMIT)
1747 die("Non commit %s?", revs->pending.objects[i].name);
1748 if (found)
1749 die("More than one commit to dig up from, %s and %s?",
1750 revs->pending.objects[i].name, name);
1751 found = (struct commit *) obj;
1752 name = revs->pending.objects[i].name;
1753 }
1754
1755 if (!name)
1756 found = dwim_reverse_initial(revs, &name);
1757 if (!name)
1758 die("No commit to dig up from?");
1759
1760 if (name_p)
9e7d8a9b 1761 *name_p = xstrdup(name);
09002f1b
JS
1762 return found;
1763}
1764
1765void init_scoreboard(struct blame_scoreboard *sb)
1766{
1767 memset(sb, 0, sizeof(struct blame_scoreboard));
1768 sb->move_score = BLAME_DEFAULT_MOVE_SCORE;
1769 sb->copy_score = BLAME_DEFAULT_COPY_SCORE;
1770}
1771
ecbbc0a5
NTND
1772void setup_scoreboard(struct blame_scoreboard *sb,
1773 const char *path,
1774 struct blame_origin **orig)
09002f1b
JS
1775{
1776 const char *final_commit_name = NULL;
1777 struct blame_origin *o;
1778 struct commit *final_commit = NULL;
1779 enum object_type type;
1780
4e0df4e6
NTND
1781 init_blame_suspects(&blame_suspects);
1782
09002f1b
JS
1783 if (sb->reverse && sb->contents_from)
1784 die(_("--contents and --reverse do not blend well."));
1785
ecbbc0a5
NTND
1786 if (!sb->repo)
1787 BUG("repo is NULL");
1788
09002f1b
JS
1789 if (!sb->reverse) {
1790 sb->final = find_single_final(sb->revs, &final_commit_name);
1791 sb->commits.compare = compare_commits_by_commit_date;
1792 } else {
1793 sb->final = find_single_initial(sb->revs, &final_commit_name);
1794 sb->commits.compare = compare_commits_by_reverse_commit_date;
1795 }
1796
1797 if (sb->final && sb->contents_from)
1798 die(_("cannot use --contents with final commit object name"));
1799
1800 if (sb->reverse && sb->revs->first_parent_only)
1801 sb->revs->children.name = NULL;
1802
1803 if (!sb->final) {
1804 /*
1805 * "--not A B -- path" without anything positive;
1806 * do not default to HEAD, but use the working tree
1807 * or "--contents".
1808 */
1809 setup_work_tree();
ecbbc0a5
NTND
1810 sb->final = fake_working_tree_commit(sb->repo,
1811 &sb->revs->diffopt,
09002f1b
JS
1812 path, sb->contents_from);
1813 add_pending_object(sb->revs, &(sb->final->object), ":");
1814 }
1815
1816 if (sb->reverse && sb->revs->first_parent_only) {
1817 final_commit = find_single_final(sb->revs, NULL);
1818 if (!final_commit)
1819 die(_("--reverse and --first-parent together require specified latest commit"));
1820 }
1821
1822 /*
1823 * If we have bottom, this will mark the ancestors of the
1824 * bottom commits we would reach while traversing as
1825 * uninteresting.
1826 */
1827 if (prepare_revision_walk(sb->revs))
1828 die(_("revision walk setup failed"));
1829
1830 if (sb->reverse && sb->revs->first_parent_only) {
1831 struct commit *c = final_commit;
1832
1833 sb->revs->children.name = "children";
1834 while (c->parents &&
1835 oidcmp(&c->object.oid, &sb->final->object.oid)) {
1836 struct commit_list *l = xcalloc(1, sizeof(*l));
1837
1838 l->item = c;
1839 if (add_decoration(&sb->revs->children,
1840 &c->parents->item->object, l))
033abf97 1841 BUG("not unique item in first-parent chain");
09002f1b
JS
1842 c = c->parents->item;
1843 }
1844
1845 if (oidcmp(&c->object.oid, &sb->final->object.oid))
1846 die(_("--reverse --first-parent together require range along first-parent chain"));
1847 }
1848
1849 if (is_null_oid(&sb->final->object.oid)) {
4e0df4e6 1850 o = get_blame_suspects(sb->final);
09002f1b
JS
1851 sb->final_buf = xmemdupz(o->file.ptr, o->file.size);
1852 sb->final_buf_size = o->file.size;
1853 }
1854 else {
1855 o = get_origin(sb->final, path);
ecbbc0a5 1856 if (fill_blob_sha1_and_mode(sb->repo, o))
09002f1b
JS
1857 die(_("no such path %s in %s"), path, final_commit_name);
1858
0d1e0e78 1859 if (sb->revs->diffopt.flags.allow_textconv &&
09002f1b
JS
1860 textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
1861 &sb->final_buf_size))
1862 ;
1863 else
b4f5aca4 1864 sb->final_buf = read_object_file(&o->blob_oid, &type,
1865 &sb->final_buf_size);
09002f1b
JS
1866
1867 if (!sb->final_buf)
1868 die(_("cannot read blob %s for path %s"),
1869 oid_to_hex(&o->blob_oid),
1870 path);
1871 }
1872 sb->num_read_blob++;
1873 prepare_lines(sb);
1874
1875 if (orig)
1876 *orig = o;
9e7d8a9b
SG
1877
1878 free((char *)final_commit_name);
09002f1b 1879}
bd481de7
JS
1880
1881
1882
1883struct blame_entry *blame_entry_prepend(struct blame_entry *head,
1884 long start, long end,
1885 struct blame_origin *o)
1886{
1887 struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
1888 new_head->lno = start;
1889 new_head->num_lines = end - start;
1890 new_head->suspect = o;
1891 new_head->s_lno = start;
1892 new_head->next = head;
1893 blame_origin_incref(o);
1894 return new_head;
1895}