1#include "cache.h" 2#include "refs.h" 3#include "object-store.h" 4#include "cache-tree.h" 5#include "mergesort.h" 6#include "diff.h" 7#include "diffcore.h" 8#include "tag.h" 9#include "blame.h" 10#include "alloc.h" 11#include "commit-slab.h" 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} 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 */ 38 for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) { 39 if (p == o) { 40 if (l) 41 l->next = p->next; 42 else 43 set_blame_suspects(o->commit, p->next); 44 free(o); 45 return; 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 */ 58static struct blame_origin *make_origin(struct commit *commit, const char *path) 59{ 60 struct blame_origin *o; 61 FLEX_ALLOC_STR(o, path, path); 62 o->commit = commit; 63 o->refcnt = 1; 64 o->next = get_blame_suspects(commit); 65 set_blame_suspects(commit, o); 66 return o; 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 */ 73static struct blame_origin *get_origin(struct commit *commit, const char *path) 74{ 75 struct blame_origin *o, *l; 76 77 for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) { 78 if (!strcmp(o->path, path)) { 79 /* bump to front */ 80 if (l) { 81 l->next = o->next; 82 o->next = get_blame_suspects(commit); 83 set_blame_suspects(commit, o); 84 } 85 return blame_origin_incref(o); 86 } 87 } 88 return make_origin(commit, path); 89} 90 91 92 93static void verify_working_tree_path(struct commit *work_tree, const char *path) 94{ 95 struct commit_list *parents; 96 int pos; 97 98 for (parents = work_tree->parents; parents; parents = parents->next) { 99 const struct object_id *commit_oid = &parents->item->object.oid; 100 struct object_id blob_oid; 101 unsigned mode; 102 103 if (!get_tree_entry(commit_oid, path, &blob_oid, &mode) && 104 oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB) 105 return; 106 } 107 108 pos = cache_name_pos(path, strlen(path)); 109 if (pos >= 0) 110 ; /* path is in the index */ 111 else if (-1 - pos < active_nr && 112 !strcmp(active_cache[-1 - pos]->name, path)) 113 ; /* path is in the index, unmerged */ 114 else 115 die("no such path '%s' in HEAD", path); 116} 117 118static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid) 119{ 120 struct commit *parent; 121 122 parent = lookup_commit_reference(the_repository, oid); 123 if (!parent) 124 die("no such commit %s", oid_to_hex(oid)); 125 return &commit_list_insert(parent, tail)->next; 126} 127 128static void append_merge_parents(struct commit_list **tail) 129{ 130 int merge_head; 131 struct strbuf line = STRBUF_INIT; 132 133 merge_head = open(git_path_merge_head(the_repository), O_RDONLY); 134 if (merge_head < 0) { 135 if (errno == ENOENT) 136 return; 137 die("cannot open '%s' for reading", 138 git_path_merge_head(the_repository)); 139 } 140 141 while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) { 142 struct object_id oid; 143 if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid)) 144 die("unknown line in '%s': %s", 145 git_path_merge_head(the_repository), line.buf); 146 tail = append_parent(tail, &oid); 147 } 148 close(merge_head); 149 strbuf_release(&line); 150} 151 152/* 153 * This isn't as simple as passing sb->buf and sb->len, because we 154 * want to transfer ownership of the buffer to the commit (so we 155 * must use detach). 156 */ 157static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb) 158{ 159 size_t len; 160 void *buf = strbuf_detach(sb, &len); 161 set_commit_buffer(the_repository, c, buf, len); 162} 163 164/* 165 * Prepare a dummy commit that represents the work tree (or staged) item. 166 * Note that annotating work tree item never works in the reverse. 167 */ 168static struct commit *fake_working_tree_commit(struct diff_options *opt, 169 const char *path, 170 const char *contents_from) 171{ 172 struct commit *commit; 173 struct blame_origin *origin; 174 struct commit_list **parent_tail, *parent; 175 struct object_id head_oid; 176 struct strbuf buf = STRBUF_INIT; 177 const char *ident; 178 time_t now; 179 int len; 180 struct cache_entry *ce; 181 unsigned mode; 182 struct strbuf msg = STRBUF_INIT; 183 184 read_cache(); 185 time(&now); 186 commit = alloc_commit_node(the_repository); 187 commit->object.parsed = 1; 188 commit->date = now; 189 parent_tail = &commit->parents; 190 191 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) 192 die("no such ref: HEAD"); 193 194 parent_tail = append_parent(parent_tail, &head_oid); 195 append_merge_parents(parent_tail); 196 verify_working_tree_path(commit, path); 197 198 origin = make_origin(commit, path); 199 200 ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0); 201 strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n"); 202 for (parent = commit->parents; parent; parent = parent->next) 203 strbuf_addf(&msg, "parent %s\n", 204 oid_to_hex(&parent->item->object.oid)); 205 strbuf_addf(&msg, 206 "author %s\n" 207 "committer %s\n\n" 208 "Version of %s from %s\n", 209 ident, ident, path, 210 (!contents_from ? path : 211 (!strcmp(contents_from, "-") ? "standard input" : contents_from))); 212 set_commit_buffer_from_strbuf(commit, &msg); 213 214 if (!contents_from || strcmp("-", contents_from)) { 215 struct stat st; 216 const char *read_from; 217 char *buf_ptr; 218 unsigned long buf_len; 219 220 if (contents_from) { 221 if (stat(contents_from, &st) < 0) 222 die_errno("Cannot stat '%s'", contents_from); 223 read_from = contents_from; 224 } 225 else { 226 if (lstat(path, &st) < 0) 227 die_errno("Cannot lstat '%s'", path); 228 read_from = path; 229 } 230 mode = canon_mode(st.st_mode); 231 232 switch (st.st_mode & S_IFMT) { 233 case S_IFREG: 234 if (opt->flags.allow_textconv && 235 textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len)) 236 strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1); 237 else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size) 238 die_errno("cannot open or read '%s'", read_from); 239 break; 240 case S_IFLNK: 241 if (strbuf_readlink(&buf, read_from, st.st_size) < 0) 242 die_errno("cannot readlink '%s'", read_from); 243 break; 244 default: 245 die("unsupported file type %s", read_from); 246 } 247 } 248 else { 249 /* Reading from stdin */ 250 mode = 0; 251 if (strbuf_read(&buf, 0, 0) < 0) 252 die_errno("failed to read from stdin"); 253 } 254 convert_to_git(&the_index, path, buf.buf, buf.len, &buf, 0); 255 origin->file.ptr = buf.buf; 256 origin->file.size = buf.len; 257 pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid); 258 259 /* 260 * Read the current index, replace the path entry with 261 * origin->blob_sha1 without mucking with its mode or type 262 * bits; we are not going to write this index out -- we just 263 * want to run "diff-index --cached". 264 */ 265 discard_cache(); 266 read_cache(); 267 268 len = strlen(path); 269 if (!mode) { 270 int pos = cache_name_pos(path, len); 271 if (0 <= pos) 272 mode = active_cache[pos]->ce_mode; 273 else 274 /* Let's not bother reading from HEAD tree */ 275 mode = S_IFREG | 0644; 276 } 277 ce = make_empty_cache_entry(&the_index, len); 278 oidcpy(&ce->oid, &origin->blob_oid); 279 memcpy(ce->name, path, len); 280 ce->ce_flags = create_ce_flags(0); 281 ce->ce_namelen = len; 282 ce->ce_mode = create_ce_mode(mode); 283 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); 284 285 cache_tree_invalidate_path(&the_index, path); 286 287 return commit; 288} 289 290 291 292static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, 293 xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts) 294{ 295 xpparam_t xpp = {0}; 296 xdemitconf_t xecfg = {0}; 297 xdemitcb_t ecb = {NULL}; 298 299 xpp.flags = xdl_opts; 300 xecfg.hunk_func = hunk_func; 301 ecb.priv = cb_data; 302 return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb); 303} 304 305/* 306 * Given an origin, prepare mmfile_t structure to be used by the 307 * diff machinery 308 */ 309static void fill_origin_blob(struct diff_options *opt, 310 struct blame_origin *o, mmfile_t *file, int *num_read_blob) 311{ 312 if (!o->file.ptr) { 313 enum object_type type; 314 unsigned long file_size; 315 316 (*num_read_blob)++; 317 if (opt->flags.allow_textconv && 318 textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size)) 319 ; 320 else 321 file->ptr = read_object_file(&o->blob_oid, &type, 322 &file_size); 323 file->size = file_size; 324 325 if (!file->ptr) 326 die("Cannot read blob %s for path %s", 327 oid_to_hex(&o->blob_oid), 328 o->path); 329 o->file = *file; 330 } 331 else 332 *file = o->file; 333} 334 335static void drop_origin_blob(struct blame_origin *o) 336{ 337 if (o->file.ptr) { 338 FREE_AND_NULL(o->file.ptr); 339 } 340} 341 342/* 343 * Any merge of blames happens on lists of blames that arrived via 344 * different parents in a single suspect. In this case, we want to 345 * sort according to the suspect line numbers as opposed to the final 346 * image line numbers. The function body is somewhat longish because 347 * it avoids unnecessary writes. 348 */ 349 350static struct blame_entry *blame_merge(struct blame_entry *list1, 351 struct blame_entry *list2) 352{ 353 struct blame_entry *p1 = list1, *p2 = list2, 354 **tail = &list1; 355 356 if (!p1) 357 return p2; 358 if (!p2) 359 return p1; 360 361 if (p1->s_lno <= p2->s_lno) { 362 do { 363 tail = &p1->next; 364 if ((p1 = *tail) == NULL) { 365 *tail = p2; 366 return list1; 367 } 368 } while (p1->s_lno <= p2->s_lno); 369 } 370 for (;;) { 371 *tail = p2; 372 do { 373 tail = &p2->next; 374 if ((p2 = *tail) == NULL) { 375 *tail = p1; 376 return list1; 377 } 378 } while (p1->s_lno > p2->s_lno); 379 *tail = p1; 380 do { 381 tail = &p1->next; 382 if ((p1 = *tail) == NULL) { 383 *tail = p2; 384 return list1; 385 } 386 } while (p1->s_lno <= p2->s_lno); 387 } 388} 389 390static void *get_next_blame(const void *p) 391{ 392 return ((struct blame_entry *)p)->next; 393} 394 395static void set_next_blame(void *p1, void *p2) 396{ 397 ((struct blame_entry *)p1)->next = p2; 398} 399 400/* 401 * Final image line numbers are all different, so we don't need a 402 * three-way comparison here. 403 */ 404 405static int compare_blame_final(const void *p1, const void *p2) 406{ 407 return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno 408 ? 1 : -1; 409} 410 411static int compare_blame_suspect(const void *p1, const void *p2) 412{ 413 const struct blame_entry *s1 = p1, *s2 = p2; 414 /* 415 * to allow for collating suspects, we sort according to the 416 * respective pointer value as the primary sorting criterion. 417 * The actual relation is pretty unimportant as long as it 418 * establishes a total order. Comparing as integers gives us 419 * that. 420 */ 421 if (s1->suspect != s2->suspect) 422 return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1; 423 if (s1->s_lno == s2->s_lno) 424 return 0; 425 return s1->s_lno > s2->s_lno ? 1 : -1; 426} 427 428void blame_sort_final(struct blame_scoreboard *sb) 429{ 430 sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame, 431 compare_blame_final); 432} 433 434static int compare_commits_by_reverse_commit_date(const void *a, 435 const void *b, 436 void *c) 437{ 438 return -compare_commits_by_commit_date(a, b, c); 439} 440 441/* 442 * For debugging -- origin is refcounted, and this asserts that 443 * we do not underflow. 444 */ 445static void sanity_check_refcnt(struct blame_scoreboard *sb) 446{ 447 int baa = 0; 448 struct blame_entry *ent; 449 450 for (ent = sb->ent; ent; ent = ent->next) { 451 /* Nobody should have zero or negative refcnt */ 452 if (ent->suspect->refcnt <= 0) { 453 fprintf(stderr, "%s in %s has negative refcnt %d\n", 454 ent->suspect->path, 455 oid_to_hex(&ent->suspect->commit->object.oid), 456 ent->suspect->refcnt); 457 baa = 1; 458 } 459 } 460 if (baa) 461 sb->on_sanity_fail(sb, baa); 462} 463 464/* 465 * If two blame entries that are next to each other came from 466 * contiguous lines in the same origin (i.e. <commit, path> pair), 467 * merge them together. 468 */ 469void blame_coalesce(struct blame_scoreboard *sb) 470{ 471 struct blame_entry *ent, *next; 472 473 for (ent = sb->ent; ent && (next = ent->next); ent = next) { 474 if (ent->suspect == next->suspect && 475 ent->s_lno + ent->num_lines == next->s_lno) { 476 ent->num_lines += next->num_lines; 477 ent->next = next->next; 478 blame_origin_decref(next->suspect); 479 free(next); 480 ent->score = 0; 481 next = ent; /* again */ 482 } 483 } 484 485 if (sb->debug) /* sanity */ 486 sanity_check_refcnt(sb); 487} 488 489/* 490 * Merge the given sorted list of blames into a preexisting origin. 491 * If there were no previous blames to that commit, it is entered into 492 * the commit priority queue of the score board. 493 */ 494 495static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin, 496 struct blame_entry *sorted) 497{ 498 if (porigin->suspects) 499 porigin->suspects = blame_merge(porigin->suspects, sorted); 500 else { 501 struct blame_origin *o; 502 for (o = get_blame_suspects(porigin->commit); o; o = o->next) { 503 if (o->suspects) { 504 porigin->suspects = sorted; 505 return; 506 } 507 } 508 porigin->suspects = sorted; 509 prio_queue_put(&sb->commits, porigin->commit); 510 } 511} 512 513/* 514 * Fill the blob_sha1 field of an origin if it hasn't, so that later 515 * call to fill_origin_blob() can use it to locate the data. blob_sha1 516 * for an origin is also used to pass the blame for the entire file to 517 * the parent to detect the case where a child's blob is identical to 518 * that of its parent's. 519 * 520 * This also fills origin->mode for corresponding tree path. 521 */ 522static int fill_blob_sha1_and_mode(struct blame_origin *origin) 523{ 524 if (!is_null_oid(&origin->blob_oid)) 525 return 0; 526 if (get_tree_entry(&origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode)) 527 goto error_out; 528 if (oid_object_info(the_repository, &origin->blob_oid, NULL) != OBJ_BLOB) 529 goto error_out; 530 return 0; 531 error_out: 532 oidclr(&origin->blob_oid); 533 origin->mode = S_IFINVALID; 534 return -1; 535} 536 537/* 538 * We have an origin -- check if the same path exists in the 539 * parent and return an origin structure to represent it. 540 */ 541static struct blame_origin *find_origin(struct commit *parent, 542 struct blame_origin *origin) 543{ 544 struct blame_origin *porigin; 545 struct diff_options diff_opts; 546 const char *paths[2]; 547 548 /* First check any existing origins */ 549 for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next) 550 if (!strcmp(porigin->path, origin->path)) { 551 /* 552 * The same path between origin and its parent 553 * without renaming -- the most common case. 554 */ 555 return blame_origin_incref (porigin); 556 } 557 558 /* See if the origin->path is different between parent 559 * and origin first. Most of the time they are the 560 * same and diff-tree is fairly efficient about this. 561 */ 562 diff_setup(&diff_opts); 563 diff_opts.flags.recursive = 1; 564 diff_opts.detect_rename = 0; 565 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; 566 paths[0] = origin->path; 567 paths[1] = NULL; 568 569 parse_pathspec(&diff_opts.pathspec, 570 PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL, 571 PATHSPEC_LITERAL_PATH, "", paths); 572 diff_setup_done(&diff_opts); 573 574 if (is_null_oid(&origin->commit->object.oid)) 575 do_diff_cache(get_commit_tree_oid(parent), &diff_opts); 576 else 577 diff_tree_oid(get_commit_tree_oid(parent), 578 get_commit_tree_oid(origin->commit), 579 "", &diff_opts); 580 diffcore_std(&diff_opts); 581 582 if (!diff_queued_diff.nr) { 583 /* The path is the same as parent */ 584 porigin = get_origin(parent, origin->path); 585 oidcpy(&porigin->blob_oid, &origin->blob_oid); 586 porigin->mode = origin->mode; 587 } else { 588 /* 589 * Since origin->path is a pathspec, if the parent 590 * commit had it as a directory, we will see a whole 591 * bunch of deletion of files in the directory that we 592 * do not care about. 593 */ 594 int i; 595 struct diff_filepair *p = NULL; 596 for (i = 0; i < diff_queued_diff.nr; i++) { 597 const char *name; 598 p = diff_queued_diff.queue[i]; 599 name = p->one->path ? p->one->path : p->two->path; 600 if (!strcmp(name, origin->path)) 601 break; 602 } 603 if (!p) 604 die("internal error in blame::find_origin"); 605 switch (p->status) { 606 default: 607 die("internal error in blame::find_origin (%c)", 608 p->status); 609 case 'M': 610 porigin = get_origin(parent, origin->path); 611 oidcpy(&porigin->blob_oid, &p->one->oid); 612 porigin->mode = p->one->mode; 613 break; 614 case 'A': 615 case 'T': 616 /* Did not exist in parent, or type changed */ 617 break; 618 } 619 } 620 diff_flush(&diff_opts); 621 clear_pathspec(&diff_opts.pathspec); 622 return porigin; 623} 624 625/* 626 * We have an origin -- find the path that corresponds to it in its 627 * parent and return an origin structure to represent it. 628 */ 629static struct blame_origin *find_rename(struct commit *parent, 630 struct blame_origin *origin) 631{ 632 struct blame_origin *porigin = NULL; 633 struct diff_options diff_opts; 634 int i; 635 636 diff_setup(&diff_opts); 637 diff_opts.flags.recursive = 1; 638 diff_opts.detect_rename = DIFF_DETECT_RENAME; 639 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; 640 diff_opts.single_follow = origin->path; 641 diff_setup_done(&diff_opts); 642 643 if (is_null_oid(&origin->commit->object.oid)) 644 do_diff_cache(get_commit_tree_oid(parent), &diff_opts); 645 else 646 diff_tree_oid(get_commit_tree_oid(parent), 647 get_commit_tree_oid(origin->commit), 648 "", &diff_opts); 649 diffcore_std(&diff_opts); 650 651 for (i = 0; i < diff_queued_diff.nr; i++) { 652 struct diff_filepair *p = diff_queued_diff.queue[i]; 653 if ((p->status == 'R' || p->status == 'C') && 654 !strcmp(p->two->path, origin->path)) { 655 porigin = get_origin(parent, p->one->path); 656 oidcpy(&porigin->blob_oid, &p->one->oid); 657 porigin->mode = p->one->mode; 658 break; 659 } 660 } 661 diff_flush(&diff_opts); 662 clear_pathspec(&diff_opts.pathspec); 663 return porigin; 664} 665 666/* 667 * Append a new blame entry to a given output queue. 668 */ 669static void add_blame_entry(struct blame_entry ***queue, 670 const struct blame_entry *src) 671{ 672 struct blame_entry *e = xmalloc(sizeof(*e)); 673 memcpy(e, src, sizeof(*e)); 674 blame_origin_incref(e->suspect); 675 676 e->next = **queue; 677 **queue = e; 678 *queue = &e->next; 679} 680 681/* 682 * src typically is on-stack; we want to copy the information in it to 683 * a malloced blame_entry that gets added to the given queue. The 684 * origin of dst loses a refcnt. 685 */ 686static void dup_entry(struct blame_entry ***queue, 687 struct blame_entry *dst, struct blame_entry *src) 688{ 689 blame_origin_incref(src->suspect); 690 blame_origin_decref(dst->suspect); 691 memcpy(dst, src, sizeof(*src)); 692 dst->next = **queue; 693 **queue = dst; 694 *queue = &dst->next; 695} 696 697const char *blame_nth_line(struct blame_scoreboard *sb, long lno) 698{ 699 return sb->final_buf + sb->lineno[lno]; 700} 701 702/* 703 * It is known that lines between tlno to same came from parent, and e 704 * has an overlap with that range. it also is known that parent's 705 * line plno corresponds to e's line tlno. 706 * 707 * <---- e -----> 708 * <------> 709 * <------------> 710 * <------------> 711 * <------------------> 712 * 713 * Split e into potentially three parts; before this chunk, the chunk 714 * to be blamed for the parent, and after that portion. 715 */ 716static void split_overlap(struct blame_entry *split, 717 struct blame_entry *e, 718 int tlno, int plno, int same, 719 struct blame_origin *parent) 720{ 721 int chunk_end_lno; 722 memset(split, 0, sizeof(struct blame_entry [3])); 723 724 if (e->s_lno < tlno) { 725 /* there is a pre-chunk part not blamed on parent */ 726 split[0].suspect = blame_origin_incref(e->suspect); 727 split[0].lno = e->lno; 728 split[0].s_lno = e->s_lno; 729 split[0].num_lines = tlno - e->s_lno; 730 split[1].lno = e->lno + tlno - e->s_lno; 731 split[1].s_lno = plno; 732 } 733 else { 734 split[1].lno = e->lno; 735 split[1].s_lno = plno + (e->s_lno - tlno); 736 } 737 738 if (same < e->s_lno + e->num_lines) { 739 /* there is a post-chunk part not blamed on parent */ 740 split[2].suspect = blame_origin_incref(e->suspect); 741 split[2].lno = e->lno + (same - e->s_lno); 742 split[2].s_lno = e->s_lno + (same - e->s_lno); 743 split[2].num_lines = e->s_lno + e->num_lines - same; 744 chunk_end_lno = split[2].lno; 745 } 746 else 747 chunk_end_lno = e->lno + e->num_lines; 748 split[1].num_lines = chunk_end_lno - split[1].lno; 749 750 /* 751 * if it turns out there is nothing to blame the parent for, 752 * forget about the splitting. !split[1].suspect signals this. 753 */ 754 if (split[1].num_lines < 1) 755 return; 756 split[1].suspect = blame_origin_incref(parent); 757} 758 759/* 760 * split_overlap() divided an existing blame e into up to three parts 761 * in split. Any assigned blame is moved to queue to 762 * reflect the split. 763 */ 764static void split_blame(struct blame_entry ***blamed, 765 struct blame_entry ***unblamed, 766 struct blame_entry *split, 767 struct blame_entry *e) 768{ 769 if (split[0].suspect && split[2].suspect) { 770 /* The first part (reuse storage for the existing entry e) */ 771 dup_entry(unblamed, e, &split[0]); 772 773 /* The last part -- me */ 774 add_blame_entry(unblamed, &split[2]); 775 776 /* ... and the middle part -- parent */ 777 add_blame_entry(blamed, &split[1]); 778 } 779 else if (!split[0].suspect && !split[2].suspect) 780 /* 781 * The parent covers the entire area; reuse storage for 782 * e and replace it with the parent. 783 */ 784 dup_entry(blamed, e, &split[1]); 785 else if (split[0].suspect) { 786 /* me and then parent */ 787 dup_entry(unblamed, e, &split[0]); 788 add_blame_entry(blamed, &split[1]); 789 } 790 else { 791 /* parent and then me */ 792 dup_entry(blamed, e, &split[1]); 793 add_blame_entry(unblamed, &split[2]); 794 } 795} 796 797/* 798 * After splitting the blame, the origins used by the 799 * on-stack blame_entry should lose one refcnt each. 800 */ 801static void decref_split(struct blame_entry *split) 802{ 803 int i; 804 805 for (i = 0; i < 3; i++) 806 blame_origin_decref(split[i].suspect); 807} 808 809/* 810 * reverse_blame reverses the list given in head, appending tail. 811 * That allows us to build lists in reverse order, then reverse them 812 * afterwards. This can be faster than building the list in proper 813 * order right away. The reason is that building in proper order 814 * requires writing a link in the _previous_ element, while building 815 * in reverse order just requires placing the list head into the 816 * _current_ element. 817 */ 818 819static struct blame_entry *reverse_blame(struct blame_entry *head, 820 struct blame_entry *tail) 821{ 822 while (head) { 823 struct blame_entry *next = head->next; 824 head->next = tail; 825 tail = head; 826 head = next; 827 } 828 return tail; 829} 830 831/* 832 * Process one hunk from the patch between the current suspect for 833 * blame_entry e and its parent. This first blames any unfinished 834 * entries before the chunk (which is where target and parent start 835 * differing) on the parent, and then splits blame entries at the 836 * start and at the end of the difference region. Since use of -M and 837 * -C options may lead to overlapping/duplicate source line number 838 * ranges, all we can rely on from sorting/merging is the order of the 839 * first suspect line number. 840 */ 841static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq, 842 int tlno, int offset, int same, 843 struct blame_origin *parent) 844{ 845 struct blame_entry *e = **srcq; 846 struct blame_entry *samep = NULL, *diffp = NULL; 847 848 while (e && e->s_lno < tlno) { 849 struct blame_entry *next = e->next; 850 /* 851 * current record starts before differing portion. If 852 * it reaches into it, we need to split it up and 853 * examine the second part separately. 854 */ 855 if (e->s_lno + e->num_lines > tlno) { 856 /* Move second half to a new record */ 857 int len = tlno - e->s_lno; 858 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry)); 859 n->suspect = e->suspect; 860 n->lno = e->lno + len; 861 n->s_lno = e->s_lno + len; 862 n->num_lines = e->num_lines - len; 863 e->num_lines = len; 864 e->score = 0; 865 /* Push new record to diffp */ 866 n->next = diffp; 867 diffp = n; 868 } else 869 blame_origin_decref(e->suspect); 870 /* Pass blame for everything before the differing 871 * chunk to the parent */ 872 e->suspect = blame_origin_incref(parent); 873 e->s_lno += offset; 874 e->next = samep; 875 samep = e; 876 e = next; 877 } 878 /* 879 * As we don't know how much of a common stretch after this 880 * diff will occur, the currently blamed parts are all that we 881 * can assign to the parent for now. 882 */ 883 884 if (samep) { 885 **dstq = reverse_blame(samep, **dstq); 886 *dstq = &samep->next; 887 } 888 /* 889 * Prepend the split off portions: everything after e starts 890 * after the blameable portion. 891 */ 892 e = reverse_blame(diffp, e); 893 894 /* 895 * Now retain records on the target while parts are different 896 * from the parent. 897 */ 898 samep = NULL; 899 diffp = NULL; 900 while (e && e->s_lno < same) { 901 struct blame_entry *next = e->next; 902 903 /* 904 * If current record extends into sameness, need to split. 905 */ 906 if (e->s_lno + e->num_lines > same) { 907 /* 908 * Move second half to a new record to be 909 * processed by later chunks 910 */ 911 int len = same - e->s_lno; 912 struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry)); 913 n->suspect = blame_origin_incref(e->suspect); 914 n->lno = e->lno + len; 915 n->s_lno = e->s_lno + len; 916 n->num_lines = e->num_lines - len; 917 e->num_lines = len; 918 e->score = 0; 919 /* Push new record to samep */ 920 n->next = samep; 921 samep = n; 922 } 923 e->next = diffp; 924 diffp = e; 925 e = next; 926 } 927 **srcq = reverse_blame(diffp, reverse_blame(samep, e)); 928 /* Move across elements that are in the unblamable portion */ 929 if (diffp) 930 *srcq = &diffp->next; 931} 932 933struct blame_chunk_cb_data { 934 struct blame_origin *parent; 935 long offset; 936 struct blame_entry **dstq; 937 struct blame_entry **srcq; 938}; 939 940/* diff chunks are from parent to target */ 941static int blame_chunk_cb(long start_a, long count_a, 942 long start_b, long count_b, void *data) 943{ 944 struct blame_chunk_cb_data *d = data; 945 if (start_a - start_b != d->offset) 946 die("internal error in blame::blame_chunk_cb"); 947 blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b, 948 start_b + count_b, d->parent); 949 d->offset = start_a + count_a - (start_b + count_b); 950 return 0; 951} 952 953/* 954 * We are looking at the origin 'target' and aiming to pass blame 955 * for the lines it is suspected to its parent. Run diff to find 956 * which lines came from parent and pass blame for them. 957 */ 958static void pass_blame_to_parent(struct blame_scoreboard *sb, 959 struct blame_origin *target, 960 struct blame_origin *parent) 961{ 962 mmfile_t file_p, file_o; 963 struct blame_chunk_cb_data d; 964 struct blame_entry *newdest = NULL; 965 966 if (!target->suspects) 967 return; /* nothing remains for this target */ 968 969 d.parent = parent; 970 d.offset = 0; 971 d.dstq = &newdest; d.srcq = &target->suspects; 972 973 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob); 974 fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob); 975 sb->num_get_patch++; 976 977 if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts)) 978 die("unable to generate diff (%s -> %s)", 979 oid_to_hex(&parent->commit->object.oid), 980 oid_to_hex(&target->commit->object.oid)); 981 /* The rest are the same as the parent */ 982 blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent); 983 *d.dstq = NULL; 984 queue_blames(sb, parent, newdest); 985 986 return; 987} 988 989/* 990 * The lines in blame_entry after splitting blames many times can become 991 * very small and trivial, and at some point it becomes pointless to 992 * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any 993 * ordinary C program, and it is not worth to say it was copied from 994 * totally unrelated file in the parent. 995 * 996 * Compute how trivial the lines in the blame_entry are. 997 */ 998unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e) 999{1000 unsigned score;1001 const char *cp, *ep;10021003 if (e->score)1004 return e->score;10051006 score = 1;1007 cp = blame_nth_line(sb, e->lno);1008 ep = blame_nth_line(sb, e->lno + e->num_lines);1009 while (cp < ep) {1010 unsigned ch = *((unsigned char *)cp);1011 if (isalnum(ch))1012 score++;1013 cp++;1014 }1015 e->score = score;1016 return score;1017}10181019/*1020 * best_so_far[] and potential[] are both a split of an existing blame_entry1021 * that passes blame to the parent. Maintain best_so_far the best split so1022 * far, by comparing potential and best_so_far and copying potential into1023 * bst_so_far as needed.1024 */1025static void copy_split_if_better(struct blame_scoreboard *sb,1026 struct blame_entry *best_so_far,1027 struct blame_entry *potential)1028{1029 int i;10301031 if (!potential[1].suspect)1032 return;1033 if (best_so_far[1].suspect) {1034 if (blame_entry_score(sb, &potential[1]) <1035 blame_entry_score(sb, &best_so_far[1]))1036 return;1037 }10381039 for (i = 0; i < 3; i++)1040 blame_origin_incref(potential[i].suspect);1041 decref_split(best_so_far);1042 memcpy(best_so_far, potential, sizeof(struct blame_entry[3]));1043}10441045/*1046 * We are looking at a part of the final image represented by1047 * ent (tlno and same are offset by ent->s_lno).1048 * tlno is where we are looking at in the final image.1049 * up to (but not including) same match preimage.1050 * plno is where we are looking at in the preimage.1051 *1052 * <-------------- final image ---------------------->1053 * <------ent------>1054 * ^tlno ^same1055 * <---------preimage----->1056 * ^plno1057 *1058 * All line numbers are 0-based.1059 */1060static void handle_split(struct blame_scoreboard *sb,1061 struct blame_entry *ent,1062 int tlno, int plno, int same,1063 struct blame_origin *parent,1064 struct blame_entry *split)1065{1066 if (ent->num_lines <= tlno)1067 return;1068 if (tlno < same) {1069 struct blame_entry potential[3];1070 tlno += ent->s_lno;1071 same += ent->s_lno;1072 split_overlap(potential, ent, tlno, plno, same, parent);1073 copy_split_if_better(sb, split, potential);1074 decref_split(potential);1075 }1076}10771078struct handle_split_cb_data {1079 struct blame_scoreboard *sb;1080 struct blame_entry *ent;1081 struct blame_origin *parent;1082 struct blame_entry *split;1083 long plno;1084 long tlno;1085};10861087static int handle_split_cb(long start_a, long count_a,1088 long start_b, long count_b, void *data)1089{1090 struct handle_split_cb_data *d = data;1091 handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,1092 d->split);1093 d->plno = start_a + count_a;1094 d->tlno = start_b + count_b;1095 return 0;1096}10971098/*1099 * Find the lines from parent that are the same as ent so that1100 * we can pass blames to it. file_p has the blob contents for1101 * the parent.1102 */1103static void find_copy_in_blob(struct blame_scoreboard *sb,1104 struct blame_entry *ent,1105 struct blame_origin *parent,1106 struct blame_entry *split,1107 mmfile_t *file_p)1108{1109 const char *cp;1110 mmfile_t file_o;1111 struct handle_split_cb_data d;11121113 memset(&d, 0, sizeof(d));1114 d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;1115 /*1116 * Prepare mmfile that contains only the lines in ent.1117 */1118 cp = blame_nth_line(sb, ent->lno);1119 file_o.ptr = (char *) cp;1120 file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;11211122 /*1123 * file_o is a part of final image we are annotating.1124 * file_p partially may match that image.1125 */1126 memset(split, 0, sizeof(struct blame_entry [3]));1127 if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))1128 die("unable to generate diff (%s)",1129 oid_to_hex(&parent->commit->object.oid));1130 /* remainder, if any, all match the preimage */1131 handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);1132}11331134/* Move all blame entries from list *source that have a score smaller1135 * than score_min to the front of list *small.1136 * Returns a pointer to the link pointing to the old head of the small list.1137 */11381139static struct blame_entry **filter_small(struct blame_scoreboard *sb,1140 struct blame_entry **small,1141 struct blame_entry **source,1142 unsigned score_min)1143{1144 struct blame_entry *p = *source;1145 struct blame_entry *oldsmall = *small;1146 while (p) {1147 if (blame_entry_score(sb, p) <= score_min) {1148 *small = p;1149 small = &p->next;1150 p = *small;1151 } else {1152 *source = p;1153 source = &p->next;1154 p = *source;1155 }1156 }1157 *small = oldsmall;1158 *source = NULL;1159 return small;1160}11611162/*1163 * See if lines currently target is suspected for can be attributed to1164 * parent.1165 */1166static void find_move_in_parent(struct blame_scoreboard *sb,1167 struct blame_entry ***blamed,1168 struct blame_entry **toosmall,1169 struct blame_origin *target,1170 struct blame_origin *parent)1171{1172 struct blame_entry *e, split[3];1173 struct blame_entry *unblamed = target->suspects;1174 struct blame_entry *leftover = NULL;1175 mmfile_t file_p;11761177 if (!unblamed)1178 return; /* nothing remains for this target */11791180 fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);1181 if (!file_p.ptr)1182 return;11831184 /* At each iteration, unblamed has a NULL-terminated list of1185 * entries that have not yet been tested for blame. leftover1186 * contains the reversed list of entries that have been tested1187 * without being assignable to the parent.1188 */1189 do {1190 struct blame_entry **unblamedtail = &unblamed;1191 struct blame_entry *next;1192 for (e = unblamed; e; e = next) {1193 next = e->next;1194 find_copy_in_blob(sb, e, parent, split, &file_p);1195 if (split[1].suspect &&1196 sb->move_score < blame_entry_score(sb, &split[1])) {1197 split_blame(blamed, &unblamedtail, split, e);1198 } else {1199 e->next = leftover;1200 leftover = e;1201 }1202 decref_split(split);1203 }1204 *unblamedtail = NULL;1205 toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);1206 } while (unblamed);1207 target->suspects = reverse_blame(leftover, NULL);1208}12091210struct blame_list {1211 struct blame_entry *ent;1212 struct blame_entry split[3];1213};12141215/*1216 * Count the number of entries the target is suspected for,1217 * and prepare a list of entry and the best split.1218 */1219static struct blame_list *setup_blame_list(struct blame_entry *unblamed,1220 int *num_ents_p)1221{1222 struct blame_entry *e;1223 int num_ents, i;1224 struct blame_list *blame_list = NULL;12251226 for (e = unblamed, num_ents = 0; e; e = e->next)1227 num_ents++;1228 if (num_ents) {1229 blame_list = xcalloc(num_ents, sizeof(struct blame_list));1230 for (e = unblamed, i = 0; e; e = e->next)1231 blame_list[i++].ent = e;1232 }1233 *num_ents_p = num_ents;1234 return blame_list;1235}12361237/*1238 * For lines target is suspected for, see if we can find code movement1239 * across file boundary from the parent commit. porigin is the path1240 * in the parent we already tried.1241 */1242static void find_copy_in_parent(struct blame_scoreboard *sb,1243 struct blame_entry ***blamed,1244 struct blame_entry **toosmall,1245 struct blame_origin *target,1246 struct commit *parent,1247 struct blame_origin *porigin,1248 int opt)1249{1250 struct diff_options diff_opts;1251 int i, j;1252 struct blame_list *blame_list;1253 int num_ents;1254 struct blame_entry *unblamed = target->suspects;1255 struct blame_entry *leftover = NULL;12561257 if (!unblamed)1258 return; /* nothing remains for this target */12591260 diff_setup(&diff_opts);1261 diff_opts.flags.recursive = 1;1262 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;12631264 diff_setup_done(&diff_opts);12651266 /* Try "find copies harder" on new path if requested;1267 * we do not want to use diffcore_rename() actually to1268 * match things up; find_copies_harder is set only to1269 * force diff_tree_oid() to feed all filepairs to diff_queue,1270 * and this code needs to be after diff_setup_done(), which1271 * usually makes find-copies-harder imply copy detection.1272 */1273 if ((opt & PICKAXE_BLAME_COPY_HARDEST)1274 || ((opt & PICKAXE_BLAME_COPY_HARDER)1275 && (!porigin || strcmp(target->path, porigin->path))))1276 diff_opts.flags.find_copies_harder = 1;12771278 if (is_null_oid(&target->commit->object.oid))1279 do_diff_cache(get_commit_tree_oid(parent), &diff_opts);1280 else1281 diff_tree_oid(get_commit_tree_oid(parent),1282 get_commit_tree_oid(target->commit),1283 "", &diff_opts);12841285 if (!diff_opts.flags.find_copies_harder)1286 diffcore_std(&diff_opts);12871288 do {1289 struct blame_entry **unblamedtail = &unblamed;1290 blame_list = setup_blame_list(unblamed, &num_ents);12911292 for (i = 0; i < diff_queued_diff.nr; i++) {1293 struct diff_filepair *p = diff_queued_diff.queue[i];1294 struct blame_origin *norigin;1295 mmfile_t file_p;1296 struct blame_entry potential[3];12971298 if (!DIFF_FILE_VALID(p->one))1299 continue; /* does not exist in parent */1300 if (S_ISGITLINK(p->one->mode))1301 continue; /* ignore git links */1302 if (porigin && !strcmp(p->one->path, porigin->path))1303 /* find_move already dealt with this path */1304 continue;13051306 norigin = get_origin(parent, p->one->path);1307 oidcpy(&norigin->blob_oid, &p->one->oid);1308 norigin->mode = p->one->mode;1309 fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);1310 if (!file_p.ptr)1311 continue;13121313 for (j = 0; j < num_ents; j++) {1314 find_copy_in_blob(sb, blame_list[j].ent,1315 norigin, potential, &file_p);1316 copy_split_if_better(sb, blame_list[j].split,1317 potential);1318 decref_split(potential);1319 }1320 blame_origin_decref(norigin);1321 }13221323 for (j = 0; j < num_ents; j++) {1324 struct blame_entry *split = blame_list[j].split;1325 if (split[1].suspect &&1326 sb->copy_score < blame_entry_score(sb, &split[1])) {1327 split_blame(blamed, &unblamedtail, split,1328 blame_list[j].ent);1329 } else {1330 blame_list[j].ent->next = leftover;1331 leftover = blame_list[j].ent;1332 }1333 decref_split(split);1334 }1335 free(blame_list);1336 *unblamedtail = NULL;1337 toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);1338 } while (unblamed);1339 target->suspects = reverse_blame(leftover, NULL);1340 diff_flush(&diff_opts);1341 clear_pathspec(&diff_opts.pathspec);1342}13431344/*1345 * The blobs of origin and porigin exactly match, so everything1346 * origin is suspected for can be blamed on the parent.1347 */1348static void pass_whole_blame(struct blame_scoreboard *sb,1349 struct blame_origin *origin, struct blame_origin *porigin)1350{1351 struct blame_entry *e, *suspects;13521353 if (!porigin->file.ptr && origin->file.ptr) {1354 /* Steal its file */1355 porigin->file = origin->file;1356 origin->file.ptr = NULL;1357 }1358 suspects = origin->suspects;1359 origin->suspects = NULL;1360 for (e = suspects; e; e = e->next) {1361 blame_origin_incref(porigin);1362 blame_origin_decref(e->suspect);1363 e->suspect = porigin;1364 }1365 queue_blames(sb, porigin, suspects);1366}13671368/*1369 * We pass blame from the current commit to its parents. We keep saying1370 * "parent" (and "porigin"), but what we mean is to find scapegoat to1371 * exonerate ourselves.1372 */1373static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,1374 int reverse)1375{1376 if (!reverse) {1377 if (revs->first_parent_only &&1378 commit->parents &&1379 commit->parents->next) {1380 free_commit_list(commit->parents->next);1381 commit->parents->next = NULL;1382 }1383 return commit->parents;1384 }1385 return lookup_decoration(&revs->children, &commit->object);1386}13871388static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)1389{1390 struct commit_list *l = first_scapegoat(revs, commit, reverse);1391 return commit_list_count(l);1392}13931394/* Distribute collected unsorted blames to the respected sorted lists1395 * in the various origins.1396 */1397static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)1398{1399 blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,1400 compare_blame_suspect);1401 while (blamed)1402 {1403 struct blame_origin *porigin = blamed->suspect;1404 struct blame_entry *suspects = NULL;1405 do {1406 struct blame_entry *next = blamed->next;1407 blamed->next = suspects;1408 suspects = blamed;1409 blamed = next;1410 } while (blamed && blamed->suspect == porigin);1411 suspects = reverse_blame(suspects, NULL);1412 queue_blames(sb, porigin, suspects);1413 }1414}14151416#define MAXSG 1614171418static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)1419{1420 struct rev_info *revs = sb->revs;1421 int i, pass, num_sg;1422 struct commit *commit = origin->commit;1423 struct commit_list *sg;1424 struct blame_origin *sg_buf[MAXSG];1425 struct blame_origin *porigin, **sg_origin = sg_buf;1426 struct blame_entry *toosmall = NULL;1427 struct blame_entry *blames, **blametail = &blames;14281429 num_sg = num_scapegoats(revs, commit, sb->reverse);1430 if (!num_sg)1431 goto finish;1432 else if (num_sg < ARRAY_SIZE(sg_buf))1433 memset(sg_buf, 0, sizeof(sg_buf));1434 else1435 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));14361437 /*1438 * The first pass looks for unrenamed path to optimize for1439 * common cases, then we look for renames in the second pass.1440 */1441 for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {1442 struct blame_origin *(*find)(struct commit *, struct blame_origin *);1443 find = pass ? find_rename : find_origin;14441445 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);1446 i < num_sg && sg;1447 sg = sg->next, i++) {1448 struct commit *p = sg->item;1449 int j, same;14501451 if (sg_origin[i])1452 continue;1453 if (parse_commit(p))1454 continue;1455 porigin = find(p, origin);1456 if (!porigin)1457 continue;1458 if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {1459 pass_whole_blame(sb, origin, porigin);1460 blame_origin_decref(porigin);1461 goto finish;1462 }1463 for (j = same = 0; j < i; j++)1464 if (sg_origin[j] &&1465 !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {1466 same = 1;1467 break;1468 }1469 if (!same)1470 sg_origin[i] = porigin;1471 else1472 blame_origin_decref(porigin);1473 }1474 }14751476 sb->num_commits++;1477 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);1478 i < num_sg && sg;1479 sg = sg->next, i++) {1480 struct blame_origin *porigin = sg_origin[i];1481 if (!porigin)1482 continue;1483 if (!origin->previous) {1484 blame_origin_incref(porigin);1485 origin->previous = porigin;1486 }1487 pass_blame_to_parent(sb, origin, porigin);1488 if (!origin->suspects)1489 goto finish;1490 }14911492 /*1493 * Optionally find moves in parents' files.1494 */1495 if (opt & PICKAXE_BLAME_MOVE) {1496 filter_small(sb, &toosmall, &origin->suspects, sb->move_score);1497 if (origin->suspects) {1498 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);1499 i < num_sg && sg;1500 sg = sg->next, i++) {1501 struct blame_origin *porigin = sg_origin[i];1502 if (!porigin)1503 continue;1504 find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);1505 if (!origin->suspects)1506 break;1507 }1508 }1509 }15101511 /*1512 * Optionally find copies from parents' files.1513 */1514 if (opt & PICKAXE_BLAME_COPY) {1515 if (sb->copy_score > sb->move_score)1516 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);1517 else if (sb->copy_score < sb->move_score) {1518 origin->suspects = blame_merge(origin->suspects, toosmall);1519 toosmall = NULL;1520 filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);1521 }1522 if (!origin->suspects)1523 goto finish;15241525 for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);1526 i < num_sg && sg;1527 sg = sg->next, i++) {1528 struct blame_origin *porigin = sg_origin[i];1529 find_copy_in_parent(sb, &blametail, &toosmall,1530 origin, sg->item, porigin, opt);1531 if (!origin->suspects)1532 goto finish;1533 }1534 }15351536finish:1537 *blametail = NULL;1538 distribute_blame(sb, blames);1539 /*1540 * prepend toosmall to origin->suspects1541 *1542 * There is no point in sorting: this ends up on a big1543 * unsorted list in the caller anyway.1544 */1545 if (toosmall) {1546 struct blame_entry **tail = &toosmall;1547 while (*tail)1548 tail = &(*tail)->next;1549 *tail = origin->suspects;1550 origin->suspects = toosmall;1551 }1552 for (i = 0; i < num_sg; i++) {1553 if (sg_origin[i]) {1554 drop_origin_blob(sg_origin[i]);1555 blame_origin_decref(sg_origin[i]);1556 }1557 }1558 drop_origin_blob(origin);1559 if (sg_buf != sg_origin)1560 free(sg_origin);1561}15621563/*1564 * The main loop -- while we have blobs with lines whose true origin1565 * is still unknown, pick one blob, and allow its lines to pass blames1566 * to its parents. */1567void assign_blame(struct blame_scoreboard *sb, int opt)1568{1569 struct rev_info *revs = sb->revs;1570 struct commit *commit = prio_queue_get(&sb->commits);15711572 while (commit) {1573 struct blame_entry *ent;1574 struct blame_origin *suspect = get_blame_suspects(commit);15751576 /* find one suspect to break down */1577 while (suspect && !suspect->suspects)1578 suspect = suspect->next;15791580 if (!suspect) {1581 commit = prio_queue_get(&sb->commits);1582 continue;1583 }15841585 assert(commit == suspect->commit);15861587 /*1588 * We will use this suspect later in the loop,1589 * so hold onto it in the meantime.1590 */1591 blame_origin_incref(suspect);1592 parse_commit(commit);1593 if (sb->reverse ||1594 (!(commit->object.flags & UNINTERESTING) &&1595 !(revs->max_age != -1 && commit->date < revs->max_age)))1596 pass_blame(sb, suspect, opt);1597 else {1598 commit->object.flags |= UNINTERESTING;1599 if (commit->object.parsed)1600 mark_parents_uninteresting(commit);1601 }1602 /* treat root commit as boundary */1603 if (!commit->parents && !sb->show_root)1604 commit->object.flags |= UNINTERESTING;16051606 /* Take responsibility for the remaining entries */1607 ent = suspect->suspects;1608 if (ent) {1609 suspect->guilty = 1;1610 for (;;) {1611 struct blame_entry *next = ent->next;1612 if (sb->found_guilty_entry)1613 sb->found_guilty_entry(ent, sb->found_guilty_entry_data);1614 if (next) {1615 ent = next;1616 continue;1617 }1618 ent->next = sb->ent;1619 sb->ent = suspect->suspects;1620 suspect->suspects = NULL;1621 break;1622 }1623 }1624 blame_origin_decref(suspect);16251626 if (sb->debug) /* sanity */1627 sanity_check_refcnt(sb);1628 }1629}16301631static const char *get_next_line(const char *start, const char *end)1632{1633 const char *nl = memchr(start, '\n', end - start);1634 return nl ? nl + 1 : end;1635}16361637/*1638 * To allow quick access to the contents of nth line in the1639 * final image, prepare an index in the scoreboard.1640 */1641static int prepare_lines(struct blame_scoreboard *sb)1642{1643 const char *buf = sb->final_buf;1644 unsigned long len = sb->final_buf_size;1645 const char *end = buf + len;1646 const char *p;1647 int *lineno;1648 int num = 0;16491650 for (p = buf; p < end; p = get_next_line(p, end))1651 num++;16521653 ALLOC_ARRAY(sb->lineno, num + 1);1654 lineno = sb->lineno;16551656 for (p = buf; p < end; p = get_next_line(p, end))1657 *lineno++ = p - buf;16581659 *lineno = len;16601661 sb->num_lines = num;1662 return sb->num_lines;1663}16641665static struct commit *find_single_final(struct rev_info *revs,1666 const char **name_p)1667{1668 int i;1669 struct commit *found = NULL;1670 const char *name = NULL;16711672 for (i = 0; i < revs->pending.nr; i++) {1673 struct object *obj = revs->pending.objects[i].item;1674 if (obj->flags & UNINTERESTING)1675 continue;1676 obj = deref_tag(the_repository, obj, NULL, 0);1677 if (obj->type != OBJ_COMMIT)1678 die("Non commit %s?", revs->pending.objects[i].name);1679 if (found)1680 die("More than one commit to dig from %s and %s?",1681 revs->pending.objects[i].name, name);1682 found = (struct commit *)obj;1683 name = revs->pending.objects[i].name;1684 }1685 if (name_p)1686 *name_p = xstrdup_or_null(name);1687 return found;1688}16891690static struct commit *dwim_reverse_initial(struct rev_info *revs,1691 const char **name_p)1692{1693 /*1694 * DWIM "git blame --reverse ONE -- PATH" as1695 * "git blame --reverse ONE..HEAD -- PATH" but only do so1696 * when it makes sense.1697 */1698 struct object *obj;1699 struct commit *head_commit;1700 struct object_id head_oid;17011702 if (revs->pending.nr != 1)1703 return NULL;17041705 /* Is that sole rev a committish? */1706 obj = revs->pending.objects[0].item;1707 obj = deref_tag(the_repository, obj, NULL, 0);1708 if (obj->type != OBJ_COMMIT)1709 return NULL;17101711 /* Do we have HEAD? */1712 if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))1713 return NULL;1714 head_commit = lookup_commit_reference_gently(the_repository,1715 &head_oid, 1);1716 if (!head_commit)1717 return NULL;17181719 /* Turn "ONE" into "ONE..HEAD" then */1720 obj->flags |= UNINTERESTING;1721 add_pending_object(revs, &head_commit->object, "HEAD");17221723 if (name_p)1724 *name_p = revs->pending.objects[0].name;1725 return (struct commit *)obj;1726}17271728static struct commit *find_single_initial(struct rev_info *revs,1729 const char **name_p)1730{1731 int i;1732 struct commit *found = NULL;1733 const char *name = NULL;17341735 /*1736 * There must be one and only one negative commit, and it must be1737 * the boundary.1738 */1739 for (i = 0; i < revs->pending.nr; i++) {1740 struct object *obj = revs->pending.objects[i].item;1741 if (!(obj->flags & UNINTERESTING))1742 continue;1743 obj = deref_tag(the_repository, obj, NULL, 0);1744 if (obj->type != OBJ_COMMIT)1745 die("Non commit %s?", revs->pending.objects[i].name);1746 if (found)1747 die("More than one commit to dig up from, %s and %s?",1748 revs->pending.objects[i].name, name);1749 found = (struct commit *) obj;1750 name = revs->pending.objects[i].name;1751 }17521753 if (!name)1754 found = dwim_reverse_initial(revs, &name);1755 if (!name)1756 die("No commit to dig up from?");17571758 if (name_p)1759 *name_p = xstrdup(name);1760 return found;1761}17621763void init_scoreboard(struct blame_scoreboard *sb)1764{1765 memset(sb, 0, sizeof(struct blame_scoreboard));1766 sb->move_score = BLAME_DEFAULT_MOVE_SCORE;1767 sb->copy_score = BLAME_DEFAULT_COPY_SCORE;1768}17691770void setup_scoreboard(struct blame_scoreboard *sb, const char *path, struct blame_origin **orig)1771{1772 const char *final_commit_name = NULL;1773 struct blame_origin *o;1774 struct commit *final_commit = NULL;1775 enum object_type type;17761777 init_blame_suspects(&blame_suspects);17781779 if (sb->reverse && sb->contents_from)1780 die(_("--contents and --reverse do not blend well."));17811782 if (!sb->reverse) {1783 sb->final = find_single_final(sb->revs, &final_commit_name);1784 sb->commits.compare = compare_commits_by_commit_date;1785 } else {1786 sb->final = find_single_initial(sb->revs, &final_commit_name);1787 sb->commits.compare = compare_commits_by_reverse_commit_date;1788 }17891790 if (sb->final && sb->contents_from)1791 die(_("cannot use --contents with final commit object name"));17921793 if (sb->reverse && sb->revs->first_parent_only)1794 sb->revs->children.name = NULL;17951796 if (!sb->final) {1797 /*1798 * "--not A B -- path" without anything positive;1799 * do not default to HEAD, but use the working tree1800 * or "--contents".1801 */1802 setup_work_tree();1803 sb->final = fake_working_tree_commit(&sb->revs->diffopt,1804 path, sb->contents_from);1805 add_pending_object(sb->revs, &(sb->final->object), ":");1806 }18071808 if (sb->reverse && sb->revs->first_parent_only) {1809 final_commit = find_single_final(sb->revs, NULL);1810 if (!final_commit)1811 die(_("--reverse and --first-parent together require specified latest commit"));1812 }18131814 /*1815 * If we have bottom, this will mark the ancestors of the1816 * bottom commits we would reach while traversing as1817 * uninteresting.1818 */1819 if (prepare_revision_walk(sb->revs))1820 die(_("revision walk setup failed"));18211822 if (sb->reverse && sb->revs->first_parent_only) {1823 struct commit *c = final_commit;18241825 sb->revs->children.name = "children";1826 while (c->parents &&1827 oidcmp(&c->object.oid, &sb->final->object.oid)) {1828 struct commit_list *l = xcalloc(1, sizeof(*l));18291830 l->item = c;1831 if (add_decoration(&sb->revs->children,1832 &c->parents->item->object, l))1833 BUG("not unique item in first-parent chain");1834 c = c->parents->item;1835 }18361837 if (oidcmp(&c->object.oid, &sb->final->object.oid))1838 die(_("--reverse --first-parent together require range along first-parent chain"));1839 }18401841 if (is_null_oid(&sb->final->object.oid)) {1842 o = get_blame_suspects(sb->final);1843 sb->final_buf = xmemdupz(o->file.ptr, o->file.size);1844 sb->final_buf_size = o->file.size;1845 }1846 else {1847 o = get_origin(sb->final, path);1848 if (fill_blob_sha1_and_mode(o))1849 die(_("no such path %s in %s"), path, final_commit_name);18501851 if (sb->revs->diffopt.flags.allow_textconv &&1852 textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,1853 &sb->final_buf_size))1854 ;1855 else1856 sb->final_buf = read_object_file(&o->blob_oid, &type,1857 &sb->final_buf_size);18581859 if (!sb->final_buf)1860 die(_("cannot read blob %s for path %s"),1861 oid_to_hex(&o->blob_oid),1862 path);1863 }1864 sb->num_read_blob++;1865 prepare_lines(sb);18661867 if (orig)1868 *orig = o;18691870 free((char *)final_commit_name);1871}1872187318741875struct blame_entry *blame_entry_prepend(struct blame_entry *head,1876 long start, long end,1877 struct blame_origin *o)1878{1879 struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));1880 new_head->lno = start;1881 new_head->num_lines = end - start;1882 new_head->suspect = o;1883 new_head->s_lno = start;1884 new_head->next = head;1885 blame_origin_incref(o);1886 return new_head;1887}