git.oblomov.eu Git - git/blob - builtin-blame.c

   1 /*
   2  * Pickaxe
   3  *
   4  * Copyright (c) 2006, Junio C Hamano
   5  */
   6
   7 #include "cache.h"
   8 #include "builtin.h"
   9 #include "blob.h"
  10 #include "commit.h"
  11 #include "tag.h"
  12 #include "tree-walk.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "revision.h"
  16 #include "xdiff-interface.h"
  17
  18 #include <time.h>
  19 #include <sys/time.h>
  20 #include <regex.h>
  21
  22 static char blame_usage[] =
  23 "git-blame [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [commit] [--] file\n"
  24 "  -c, --compatibility Use the same output mode as git-annotate (Default: off)\n"
  25 "  -l, --long          Show long commit SHA1 (Default: off)\n"
  26 "  -t, --time          Show raw timestamp (Default: off)\n"
  27 "  -f, --show-name     Show original filename (Default: auto)\n"
  28 "  -n, --show-number   Show original linenumber (Default: off)\n"
  29 "  -p, --porcelain     Show in a format designed for machine consumption\n"
  30 "  -L n,m              Process only line range n,m, counting from 1\n"
  31 "  -M, -C              Find line movements within and across files\n"
  32 "  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
  33
  34 static int longest_file;
  35 static int longest_author;
  36 static int max_orig_digits;
  37 static int max_digits;
  38 static int max_score_digits;
  39
  40 #ifndef DEBUG
  41 #define DEBUG 0
  42 #endif
  43
  44 /* stats */
  45 static int num_read_blob;
  46 static int num_get_patch;
  47 static int num_commits;
  48
  49 #define PICKAXE_BLAME_MOVE              01
  50 #define PICKAXE_BLAME_COPY              02
  51 #define PICKAXE_BLAME_COPY_HARDER       04
  52
  53 /*
  54  * blame for a blame_entry with score lower than these thresholds
  55  * is not passed to the parent using move/copy logic.
  56  */
  57 static unsigned blame_move_score;
  58 static unsigned blame_copy_score;
  59 #define BLAME_DEFAULT_MOVE_SCORE        20
  60 #define BLAME_DEFAULT_COPY_SCORE        40
  61
  62 /* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  63 #define METAINFO_SHOWN          (1u<<12)
  64 #define MORE_THAN_ONE_PATH      (1u<<13)
  65
  66 /*
  67  * One blob in a commit that is being suspected
  68  */
  69 struct origin {
  70         int refcnt;
  71         struct commit *commit;
  72         mmfile_t file;
  73         unsigned char blob_sha1[20];
  74         char path[FLEX_ARRAY];
  75 };
  76
  77 static char *fill_origin_blob(struct origin *o, mmfile_t *file)
  78 {
  79         if (!o->file.ptr) {
  80                 char type[10];
  81                 num_read_blob++;
  82                 file->ptr = read_sha1_file(o->blob_sha1, type,
  83                                            (unsigned long *)(&(file->size)));
  84                 o->file = *file;
  85         }
  86         else
  87                 *file = o->file;
  88         return file->ptr;
  89 }
  90
  91 static inline struct origin *origin_incref(struct origin *o)
  92 {
  93         if (o)
  94                 o->refcnt++;
  95         return o;
  96 }
  97
  98 static void origin_decref(struct origin *o)
  99 {
 100         if (o && --o->refcnt <= 0) {
 101                 if (o->file.ptr)
 102                         free(o->file.ptr);
 103                 memset(o, 0, sizeof(*o));
 104                 free(o);
 105         }
 106 }
 107
 108 struct blame_entry {
 109         struct blame_entry *prev;
 110         struct blame_entry *next;
 111
 112         /* the first line of this group in the final image;
 113          * internally all line numbers are 0 based.
 114          */
 115         int lno;
 116
 117         /* how many lines this group has */
 118         int num_lines;
 119
 120         /* the commit that introduced this group into the final image */
 121         struct origin *suspect;
 122
 123         /* true if the suspect is truly guilty; false while we have not
 124          * checked if the group came from one of its parents.
 125          */
 126         char guilty;
 127
 128         /* the line number of the first line of this group in the
 129          * suspect's file; internally all line numbers are 0 based.
 130          */
 131         int s_lno;
 132
 133         /* how significant this entry is -- cached to avoid
 134          * scanning the lines over and over
 135          */
 136         unsigned score;
 137 };
 138
 139 struct scoreboard {
 140         /* the final commit (i.e. where we started digging from) */
 141         struct commit *final;
 142
 143         const char *path;
 144
 145         /* the contents in the final; pointed into by buf pointers of
 146          * blame_entries
 147          */
 148         const char *final_buf;
 149         unsigned long final_buf_size;
 150
 151         /* linked list of blames */
 152         struct blame_entry *ent;
 153
 154         /* look-up a line in the final buffer */
 155         int num_lines;
 156         int *lineno;
 157 };
 158
 159 static int cmp_suspect(struct origin *a, struct origin *b)
 160 {
 161         int cmp = hashcmp(a->commit->object.sha1, b->commit->object.sha1);
 162         if (cmp)
 163                 return cmp;
 164         return strcmp(a->path, b->path);
 165 }
 166
 167 #define cmp_suspect(a, b) ( ((a)==(b)) ? 0 : cmp_suspect(a,b) )
 168
 169 static void sanity_check_refcnt(struct scoreboard *);
 170
 171 static void coalesce(struct scoreboard *sb)
 172 {
 173         struct blame_entry *ent, *next;
 174
 175         for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 176                 if (!cmp_suspect(ent->suspect, next->suspect) &&
 177                     ent->guilty == next->guilty &&
 178                     ent->s_lno + ent->num_lines == next->s_lno) {
 179                         ent->num_lines += next->num_lines;
 180                         ent->next = next->next;
 181                         if (ent->next)
 182                                 ent->next->prev = ent;
 183                         origin_decref(next->suspect);
 184                         free(next);
 185                         ent->score = 0;
 186                         next = ent; /* again */
 187                 }
 188         }
 189
 190         if (DEBUG) /* sanity */
 191                 sanity_check_refcnt(sb);
 192 }
 193
 194 static struct origin *make_origin(struct commit *commit, const char *path)
 195 {
 196         struct origin *o;
 197         o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 198         o->commit = commit;
 199         o->refcnt = 1;
 200         strcpy(o->path, path);
 201         return o;
 202 }
 203
 204 static struct origin *get_origin(struct scoreboard *sb,
 205                                  struct commit *commit,
 206                                  const char *path)
 207 {
 208         struct blame_entry *e;
 209
 210         for (e = sb->ent; e; e = e->next) {
 211                 if (e->suspect->commit == commit &&
 212                     !strcmp(e->suspect->path, path))
 213                         return origin_incref(e->suspect);
 214         }
 215         return make_origin(commit, path);
 216 }
 217
 218 static int fill_blob_sha1(struct origin *origin)
 219 {
 220         unsigned mode;
 221         char type[10];
 222
 223         if (!is_null_sha1(origin->blob_sha1))
 224                 return 0;
 225         if (get_tree_entry(origin->commit->object.sha1,
 226                            origin->path,
 227                            origin->blob_sha1, &mode))
 228                 goto error_out;
 229         if (sha1_object_info(origin->blob_sha1, type, NULL) ||
 230             strcmp(type, blob_type))
 231                 goto error_out;
 232         return 0;
 233  error_out:
 234         hashclr(origin->blob_sha1);
 235         return -1;
 236 }
 237
 238 static struct origin *find_origin(struct scoreboard *sb,
 239                                   struct commit *parent,
 240                                   struct origin *origin)
 241 {
 242         struct origin *porigin = NULL;
 243         struct diff_options diff_opts;
 244         const char *paths[2];
 245
 246         if (parent->util) {
 247                 /* This is a freestanding copy of origin and not
 248                  * refcounted.
 249                  */
 250                 struct origin *cached = parent->util;
 251                 if (!strcmp(cached->path, origin->path)) {
 252                         porigin = get_origin(sb, parent, cached->path);
 253                         if (porigin->refcnt == 1)
 254                                 hashcpy(porigin->blob_sha1, cached->blob_sha1);
 255                         return porigin;
 256                 }
 257                 /* otherwise it was not very useful; free it */
 258                 free(parent->util);
 259                 parent->util = NULL;
 260         }
 261
 262         /* See if the origin->path is different between parent
 263          * and origin first.  Most of the time they are the
 264          * same and diff-tree is fairly efficient about this.
 265          */
 266         diff_setup(&diff_opts);
 267         diff_opts.recursive = 1;
 268         diff_opts.detect_rename = 0;
 269         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 270         paths[0] = origin->path;
 271         paths[1] = NULL;
 272
 273         diff_tree_setup_paths(paths, &diff_opts);
 274         if (diff_setup_done(&diff_opts) < 0)
 275                 die("diff-setup");
 276         diff_tree_sha1(parent->tree->object.sha1,
 277                        origin->commit->tree->object.sha1,
 278                        "", &diff_opts);
 279         diffcore_std(&diff_opts);
 280
 281         /* It is either one entry that says "modified", or "created",
 282          * or nothing.
 283          */
 284         if (!diff_queued_diff.nr) {
 285                 /* The path is the same as parent */
 286                 porigin = get_origin(sb, parent, origin->path);
 287                 hashcpy(porigin->blob_sha1, origin->blob_sha1);
 288         }
 289         else if (diff_queued_diff.nr != 1)
 290                 die("internal error in blame::find_origin");
 291         else {
 292                 struct diff_filepair *p = diff_queued_diff.queue[0];
 293                 switch (p->status) {
 294                 default:
 295                         die("internal error in blame::find_origin (%c)",
 296                             p->status);
 297                 case 'M':
 298                         porigin = get_origin(sb, parent, origin->path);
 299                         hashcpy(porigin->blob_sha1, p->one->sha1);
 300                         break;
 301                 case 'A':
 302                 case 'T':
 303                         /* Did not exist in parent, or type changed */
 304                         break;
 305                 }
 306         }
 307         diff_flush(&diff_opts);
 308         if (porigin) {
 309                 struct origin *cached;
 310                 cached = make_origin(porigin->commit, porigin->path);
 311                 hashcpy(cached->blob_sha1, porigin->blob_sha1);
 312                 parent->util = cached;
 313         }
 314         return porigin;
 315 }
 316
 317 static struct origin *find_rename(struct scoreboard *sb,
 318                                   struct commit *parent,
 319                                   struct origin *origin)
 320 {
 321         struct origin *porigin = NULL;
 322         struct diff_options diff_opts;
 323         int i;
 324         const char *paths[2];
 325
 326         diff_setup(&diff_opts);
 327         diff_opts.recursive = 1;
 328         diff_opts.detect_rename = DIFF_DETECT_RENAME;
 329         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 330         diff_opts.single_follow = origin->path;
 331         paths[0] = NULL;
 332         diff_tree_setup_paths(paths, &diff_opts);
 333         if (diff_setup_done(&diff_opts) < 0)
 334                 die("diff-setup");
 335         diff_tree_sha1(parent->tree->object.sha1,
 336                        origin->commit->tree->object.sha1,
 337                        "", &diff_opts);
 338         diffcore_std(&diff_opts);
 339
 340         for (i = 0; i < diff_queued_diff.nr; i++) {
 341                 struct diff_filepair *p = diff_queued_diff.queue[i];
 342                 if ((p->status == 'R' || p->status == 'C') &&
 343                     !strcmp(p->two->path, origin->path)) {
 344                         porigin = get_origin(sb, parent, p->one->path);
 345                         hashcpy(porigin->blob_sha1, p->one->sha1);
 346                         break;
 347                 }
 348         }
 349         diff_flush(&diff_opts);
 350         return porigin;
 351 }
 352
 353 struct chunk {
 354         /* line number in postimage; up to but not including this
 355          * line is the same as preimage
 356          */
 357         int same;
 358
 359         /* preimage line number after this chunk */
 360         int p_next;
 361
 362         /* postimage line number after this chunk */
 363         int t_next;
 364 };
 365
 366 struct patch {
 367         struct chunk *chunks;
 368         int num;
 369 };
 370
 371 struct blame_diff_state {
 372         struct xdiff_emit_state xm;
 373         struct patch *ret;
 374         unsigned hunk_post_context;
 375         unsigned hunk_in_pre_context : 1;
 376 };
 377
 378 static void process_u_diff(void *state_, char *line, unsigned long len)
 379 {
 380         struct blame_diff_state *state = state_;
 381         struct chunk *chunk;
 382         int off1, off2, len1, len2, num;
 383
 384         num = state->ret->num;
 385         if (len < 4 || line[0] != '@' || line[1] != '@') {
 386                 if (state->hunk_in_pre_context && line[0] == ' ')
 387                         state->ret->chunks[num - 1].same++;
 388                 else {
 389                         state->hunk_in_pre_context = 0;
 390                         if (line[0] == ' ')
 391                                 state->hunk_post_context++;
 392                         else
 393                                 state->hunk_post_context = 0;
 394                 }
 395                 return;
 396         }
 397
 398         if (num && state->hunk_post_context) {
 399                 chunk = &state->ret->chunks[num - 1];
 400                 chunk->p_next -= state->hunk_post_context;
 401                 chunk->t_next -= state->hunk_post_context;
 402         }
 403         state->ret->num = ++num;
 404         state->ret->chunks = xrealloc(state->ret->chunks,
 405                                       sizeof(struct chunk) * num);
 406         chunk = &state->ret->chunks[num - 1];
 407         if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
 408                 state->ret->num--;
 409                 return;
 410         }
 411
 412         /* Line numbers in patch output are one based. */
 413         off1--;
 414         off2--;
 415
 416         chunk->same = len2 ? off2 : (off2 + 1);
 417
 418         chunk->p_next = off1 + (len1 ? len1 : 1);
 419         chunk->t_next = chunk->same + len2;
 420         state->hunk_in_pre_context = 1;
 421         state->hunk_post_context = 0;
 422 }
 423
 424 static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
 425                                     int context)
 426 {
 427         struct blame_diff_state state;
 428         xpparam_t xpp;
 429         xdemitconf_t xecfg;
 430         xdemitcb_t ecb;
 431
 432         xpp.flags = XDF_NEED_MINIMAL;
 433         xecfg.ctxlen = context;
 434         xecfg.flags = 0;
 435         ecb.outf = xdiff_outf;
 436         ecb.priv = &state;
 437         memset(&state, 0, sizeof(state));
 438         state.xm.consume = process_u_diff;
 439         state.ret = xmalloc(sizeof(struct patch));
 440         state.ret->chunks = NULL;
 441         state.ret->num = 0;
 442
 443         xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
 444
 445         if (state.ret->num) {
 446                 struct chunk *chunk;
 447                 chunk = &state.ret->chunks[state.ret->num - 1];
 448                 chunk->p_next -= state.hunk_post_context;
 449                 chunk->t_next -= state.hunk_post_context;
 450         }
 451         return state.ret;
 452 }
 453
 454 static struct patch *get_patch(struct origin *parent, struct origin *origin)
 455 {
 456         mmfile_t file_p, file_o;
 457         struct patch *patch;
 458
 459         fill_origin_blob(parent, &file_p);
 460         fill_origin_blob(origin, &file_o);
 461         if (!file_p.ptr || !file_o.ptr)
 462                 return NULL;
 463         patch = compare_buffer(&file_p, &file_o, 0);
 464         num_get_patch++;
 465         return patch;
 466 }
 467
 468 static void free_patch(struct patch *p)
 469 {
 470         free(p->chunks);
 471         free(p);
 472 }
 473
 474 static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 475 {
 476         struct blame_entry *ent, *prev = NULL;
 477
 478         origin_incref(e->suspect);
 479
 480         for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 481                 prev = ent;
 482
 483         /* prev, if not NULL, is the last one that is below e */
 484         e->prev = prev;
 485         if (prev) {
 486                 e->next = prev->next;
 487                 prev->next = e;
 488         }
 489         else {
 490                 e->next = sb->ent;
 491                 sb->ent = e;
 492         }
 493         if (e->next)
 494                 e->next->prev = e;
 495 }
 496
 497 static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 498 {
 499         struct blame_entry *p, *n;
 500
 501         p = dst->prev;
 502         n = dst->next;
 503         origin_incref(src->suspect);
 504         origin_decref(dst->suspect);
 505         memcpy(dst, src, sizeof(*src));
 506         dst->prev = p;
 507         dst->next = n;
 508         dst->score = 0;
 509 }
 510
 511 static const char *nth_line(struct scoreboard *sb, int lno)
 512 {
 513         return sb->final_buf + sb->lineno[lno];
 514 }
 515
 516 static void split_overlap(struct blame_entry *split,
 517                           struct blame_entry *e,
 518                           int tlno, int plno, int same,
 519                           struct origin *parent)
 520 {
 521         /* it is known that lines between tlno to same came from
 522          * parent, and e has an overlap with that range.  it also is
 523          * known that parent's line plno corresponds to e's line tlno.
 524          *
 525          *                <---- e ----->
 526          *                   <------>
 527          *                   <------------>
 528          *             <------------>
 529          *             <------------------>
 530          *
 531          * Potentially we need to split e into three parts; before
 532          * this chunk, the chunk to be blamed for parent, and after
 533          * that portion.
 534          */
 535         int chunk_end_lno;
 536         memset(split, 0, sizeof(struct blame_entry [3]));
 537
 538         if (e->s_lno < tlno) {
 539                 /* there is a pre-chunk part not blamed on parent */
 540                 split[0].suspect = origin_incref(e->suspect);
 541                 split[0].lno = e->lno;
 542                 split[0].s_lno = e->s_lno;
 543                 split[0].num_lines = tlno - e->s_lno;
 544                 split[1].lno = e->lno + tlno - e->s_lno;
 545                 split[1].s_lno = plno;
 546         }
 547         else {
 548                 split[1].lno = e->lno;
 549                 split[1].s_lno = plno + (e->s_lno - tlno);
 550         }
 551
 552         if (same < e->s_lno + e->num_lines) {
 553                 /* there is a post-chunk part not blamed on parent */
 554                 split[2].suspect = origin_incref(e->suspect);
 555                 split[2].lno = e->lno + (same - e->s_lno);
 556                 split[2].s_lno = e->s_lno + (same - e->s_lno);
 557                 split[2].num_lines = e->s_lno + e->num_lines - same;
 558                 chunk_end_lno = split[2].lno;
 559         }
 560         else
 561                 chunk_end_lno = e->lno + e->num_lines;
 562         split[1].num_lines = chunk_end_lno - split[1].lno;
 563
 564         if (split[1].num_lines < 1)
 565                 return;
 566         split[1].suspect = origin_incref(parent);
 567 }
 568
 569 static void split_blame(struct scoreboard *sb,
 570                         struct blame_entry *split,
 571                         struct blame_entry *e)
 572 {
 573         struct blame_entry *new_entry;
 574
 575         if (split[0].suspect && split[2].suspect) {
 576                 /* we need to split e into two and add another for parent */
 577                 dup_entry(e, &split[0]);
 578
 579                 new_entry = xmalloc(sizeof(*new_entry));
 580                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 581                 add_blame_entry(sb, new_entry);
 582
 583                 new_entry = xmalloc(sizeof(*new_entry));
 584                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 585                 add_blame_entry(sb, new_entry);
 586         }
 587         else if (!split[0].suspect && !split[2].suspect)
 588                 /* parent covers the entire area */
 589                 dup_entry(e, &split[1]);
 590         else if (split[0].suspect) {
 591                 dup_entry(e, &split[0]);
 592
 593                 new_entry = xmalloc(sizeof(*new_entry));
 594                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 595                 add_blame_entry(sb, new_entry);
 596         }
 597         else {
 598                 dup_entry(e, &split[1]);
 599
 600                 new_entry = xmalloc(sizeof(*new_entry));
 601                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 602                 add_blame_entry(sb, new_entry);
 603         }
 604
 605         if (DEBUG) { /* sanity */
 606                 struct blame_entry *ent;
 607                 int lno = sb->ent->lno, corrupt = 0;
 608
 609                 for (ent = sb->ent; ent; ent = ent->next) {
 610                         if (lno != ent->lno)
 611                                 corrupt = 1;
 612                         if (ent->s_lno < 0)
 613                                 corrupt = 1;
 614                         lno += ent->num_lines;
 615                 }
 616                 if (corrupt) {
 617                         lno = sb->ent->lno;
 618                         for (ent = sb->ent; ent; ent = ent->next) {
 619                                 printf("L %8d l %8d n %8d\n",
 620                                        lno, ent->lno, ent->num_lines);
 621                                 lno = ent->lno + ent->num_lines;
 622                         }
 623                         die("oops");
 624                 }
 625         }
 626 }
 627
 628 static void decref_split(struct blame_entry *split)
 629 {
 630         int i;
 631
 632         for (i = 0; i < 3; i++)
 633                 origin_decref(split[i].suspect);
 634 }
 635
 636 static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 637                           int tlno, int plno, int same,
 638                           struct origin *parent)
 639 {
 640         struct blame_entry split[3];
 641
 642         split_overlap(split, e, tlno, plno, same, parent);
 643         if (split[1].suspect)
 644                 split_blame(sb, split, e);
 645         decref_split(split);
 646 }
 647
 648 static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 649 {
 650         struct blame_entry *e;
 651         int last_in_target = -1;
 652
 653         for (e = sb->ent; e; e = e->next) {
 654                 if (e->guilty || cmp_suspect(e->suspect, target))
 655                         continue;
 656                 if (last_in_target < e->s_lno + e->num_lines)
 657                         last_in_target = e->s_lno + e->num_lines;
 658         }
 659         return last_in_target;
 660 }
 661
 662 static void blame_chunk(struct scoreboard *sb,
 663                         int tlno, int plno, int same,
 664                         struct origin *target, struct origin *parent)
 665 {
 666         struct blame_entry *e;
 667
 668         for (e = sb->ent; e; e = e->next) {
 669                 if (e->guilty || cmp_suspect(e->suspect, target))
 670                         continue;
 671                 if (same <= e->s_lno)
 672                         continue;
 673                 if (tlno < e->s_lno + e->num_lines)
 674                         blame_overlap(sb, e, tlno, plno, same, parent);
 675         }
 676 }
 677
 678 static int pass_blame_to_parent(struct scoreboard *sb,
 679                                 struct origin *target,
 680                                 struct origin *parent)
 681 {
 682         int i, last_in_target, plno, tlno;
 683         struct patch *patch;
 684
 685         last_in_target = find_last_in_target(sb, target);
 686         if (last_in_target < 0)
 687                 return 1; /* nothing remains for this target */
 688
 689         patch = get_patch(parent, target);
 690         plno = tlno = 0;
 691         for (i = 0; i < patch->num; i++) {
 692                 struct chunk *chunk = &patch->chunks[i];
 693
 694                 blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 695                 plno = chunk->p_next;
 696                 tlno = chunk->t_next;
 697         }
 698         /* rest (i.e. anything above tlno) are the same as parent */
 699         blame_chunk(sb, tlno, plno, last_in_target, target, parent);
 700
 701         free_patch(patch);
 702         return 0;
 703 }
 704
 705 static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 706 {
 707         unsigned score;
 708         const char *cp, *ep;
 709
 710         if (e->score)
 711                 return e->score;
 712
 713         score = 1;
 714         cp = nth_line(sb, e->lno);
 715         ep = nth_line(sb, e->lno + e->num_lines);
 716         while (cp < ep) {
 717                 unsigned ch = *((unsigned char *)cp);
 718                 if (isalnum(ch))
 719                         score++;
 720                 cp++;
 721         }
 722         e->score = score;
 723         return score;
 724 }
 725
 726 static void copy_split_if_better(struct scoreboard *sb,
 727                                  struct blame_entry *best_so_far,
 728                                  struct blame_entry *this)
 729 {
 730         int i;
 731
 732         if (!this[1].suspect)
 733                 return;
 734         if (best_so_far[1].suspect) {
 735                 if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 736                         return;
 737         }
 738
 739         for (i = 0; i < 3; i++)
 740                 origin_incref(this[i].suspect);
 741         decref_split(best_so_far);
 742         memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 743 }
 744
 745 static void find_copy_in_blob(struct scoreboard *sb,
 746                               struct blame_entry *ent,
 747                               struct origin *parent,
 748                               struct blame_entry *split,
 749                               mmfile_t *file_p)
 750 {
 751         const char *cp;
 752         int cnt;
 753         mmfile_t file_o;
 754         struct patch *patch;
 755         int i, plno, tlno;
 756
 757         cp = nth_line(sb, ent->lno);
 758         file_o.ptr = (char*) cp;
 759         cnt = ent->num_lines;
 760
 761         while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 762                 if (*cp++ == '\n')
 763                         cnt--;
 764         }
 765         file_o.size = cp - file_o.ptr;
 766
 767         patch = compare_buffer(file_p, &file_o, 1);
 768
 769         memset(split, 0, sizeof(struct blame_entry [3]));
 770         plno = tlno = 0;
 771         for (i = 0; i < patch->num; i++) {
 772                 struct chunk *chunk = &patch->chunks[i];
 773
 774                 /* tlno to chunk->same are the same as ent */
 775                 if (ent->num_lines <= tlno)
 776                         break;
 777                 if (tlno < chunk->same) {
 778                         struct blame_entry this[3];
 779                         split_overlap(this, ent,
 780                                       tlno + ent->s_lno, plno,
 781                                       chunk->same + ent->s_lno,
 782                                       parent);
 783                         copy_split_if_better(sb, split, this);
 784                         decref_split(this);
 785                 }
 786                 plno = chunk->p_next;
 787                 tlno = chunk->t_next;
 788         }
 789         free_patch(patch);
 790 }
 791
 792 static int find_move_in_parent(struct scoreboard *sb,
 793                                struct origin *target,
 794                                struct origin *parent)
 795 {
 796         int last_in_target, made_progress;
 797         struct blame_entry *e, split[3];
 798         mmfile_t file_p;
 799
 800         last_in_target = find_last_in_target(sb, target);
 801         if (last_in_target < 0)
 802                 return 1; /* nothing remains for this target */
 803
 804         fill_origin_blob(parent, &file_p);
 805         if (!file_p.ptr)
 806                 return 0;
 807
 808         made_progress = 1;
 809         while (made_progress) {
 810                 made_progress = 0;
 811                 for (e = sb->ent; e; e = e->next) {
 812                         if (e->guilty || cmp_suspect(e->suspect, target))
 813                                 continue;
 814                         find_copy_in_blob(sb, e, parent, split, &file_p);
 815                         if (split[1].suspect &&
 816                             blame_move_score < ent_score(sb, &split[1])) {
 817                                 split_blame(sb, split, e);
 818                                 made_progress = 1;
 819                         }
 820                         decref_split(split);
 821                 }
 822         }
 823         return 0;
 824 }
 825
 826
 827 struct blame_list {
 828         struct blame_entry *ent;
 829         struct blame_entry split[3];
 830 };
 831
 832 static struct blame_list *setup_blame_list(struct scoreboard *sb,
 833                                            struct origin *target,
 834                                            int *num_ents_p)
 835 {
 836         struct blame_entry *e;
 837         int num_ents, i;
 838         struct blame_list *blame_list = NULL;
 839
 840         /* Count the number of entries the target is suspected for,
 841          * and prepare a list of entry and the best split.
 842          */
 843         for (e = sb->ent, num_ents = 0; e; e = e->next)
 844                 if (!e->guilty && !cmp_suspect(e->suspect, target))
 845                         num_ents++;
 846         if (num_ents) {
 847                 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
 848                 for (e = sb->ent, i = 0; e; e = e->next)
 849                         if (!e->guilty && !cmp_suspect(e->suspect, target))
 850                                 blame_list[i++].ent = e;
 851         }
 852         *num_ents_p = num_ents;
 853         return blame_list;
 854 }
 855
 856 static int find_copy_in_parent(struct scoreboard *sb,
 857                                struct origin *target,
 858                                struct commit *parent,
 859                                struct origin *porigin,
 860                                int opt)
 861 {
 862         struct diff_options diff_opts;
 863         const char *paths[1];
 864         int i, j;
 865         int retval;
 866         struct blame_list *blame_list;
 867         int num_ents;
 868
 869         blame_list = setup_blame_list(sb, target, &num_ents);
 870         if (!blame_list)
 871                 return 1; /* nothing remains for this target */
 872
 873         diff_setup(&diff_opts);
 874         diff_opts.recursive = 1;
 875         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 876
 877         paths[0] = NULL;
 878         diff_tree_setup_paths(paths, &diff_opts);
 879         if (diff_setup_done(&diff_opts) < 0)
 880                 die("diff-setup");
 881
 882         /* Try "find copies harder" on new path if requested;
 883          * we do not want to use diffcore_rename() actually to
 884          * match things up; find_copies_harder is set only to
 885          * force diff_tree_sha1() to feed all filepairs to diff_queue,
 886          * and this code needs to be after diff_setup_done(), which
 887          * usually makes find-copies-harder imply copy detection.
 888          */
 889         if ((opt & PICKAXE_BLAME_COPY_HARDER) &&
 890             (!porigin || strcmp(target->path, porigin->path)))
 891                 diff_opts.find_copies_harder = 1;
 892
 893         diff_tree_sha1(parent->tree->object.sha1,
 894                        target->commit->tree->object.sha1,
 895                        "", &diff_opts);
 896
 897         if (!diff_opts.find_copies_harder)
 898                 diffcore_std(&diff_opts);
 899
 900         retval = 0;
 901         while (1) {
 902                 int made_progress = 0;
 903
 904                 for (i = 0; i < diff_queued_diff.nr; i++) {
 905                         struct diff_filepair *p = diff_queued_diff.queue[i];
 906                         struct origin *norigin;
 907                         mmfile_t file_p;
 908                         struct blame_entry this[3];
 909
 910                         if (!DIFF_FILE_VALID(p->one))
 911                                 continue; /* does not exist in parent */
 912                         if (porigin && !strcmp(p->one->path, porigin->path))
 913                                 /* find_move already dealt with this path */
 914                                 continue;
 915
 916                         norigin = get_origin(sb, parent, p->one->path);
 917                         hashcpy(norigin->blob_sha1, p->one->sha1);
 918                         fill_origin_blob(norigin, &file_p);
 919                         if (!file_p.ptr)
 920                                 continue;
 921
 922                         for (j = 0; j < num_ents; j++) {
 923                                 find_copy_in_blob(sb, blame_list[j].ent,
 924                                                   norigin, this, &file_p);
 925                                 copy_split_if_better(sb, blame_list[j].split,
 926                                                      this);
 927                                 decref_split(this);
 928                         }
 929                         origin_decref(norigin);
 930                 }
 931
 932                 for (j = 0; j < num_ents; j++) {
 933                         struct blame_entry *split = blame_list[j].split;
 934                         if (split[1].suspect &&
 935                             blame_copy_score < ent_score(sb, &split[1])) {
 936                                 split_blame(sb, split, blame_list[j].ent);
 937                                 made_progress = 1;
 938                         }
 939                         decref_split(split);
 940                 }
 941                 free(blame_list);
 942
 943                 if (!made_progress)
 944                         break;
 945                 blame_list = setup_blame_list(sb, target, &num_ents);
 946                 if (!blame_list) {
 947                         retval = 1;
 948                         break;
 949                 }
 950         }
 951         diff_flush(&diff_opts);
 952
 953         return retval;
 954 }
 955
 956 /* The blobs of origin and porigin exactly match, so everything
 957  * origin is suspected for can be blamed on the parent.
 958  */
 959 static void pass_whole_blame(struct scoreboard *sb,
 960                              struct origin *origin, struct origin *porigin)
 961 {
 962         struct blame_entry *e;
 963
 964         if (!porigin->file.ptr && origin->file.ptr) {
 965                 /* Steal its file */
 966                 porigin->file = origin->file;
 967                 origin->file.ptr = NULL;
 968         }
 969         for (e = sb->ent; e; e = e->next) {
 970                 if (cmp_suspect(e->suspect, origin))
 971                         continue;
 972                 origin_incref(porigin);
 973                 origin_decref(e->suspect);
 974                 e->suspect = porigin;
 975         }
 976 }
 977
 978 #define MAXPARENT 16
 979
 980 static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 981 {
 982         int i, pass;
 983         struct commit *commit = origin->commit;
 984         struct commit_list *parent;
 985         struct origin *parent_origin[MAXPARENT], *porigin;
 986
 987         memset(parent_origin, 0, sizeof(parent_origin));
 988
 989         /* The first pass looks for unrenamed path to optimize for
 990          * common cases, then we look for renames in the second pass.
 991          */
 992         for (pass = 0; pass < 2; pass++) {
 993                 struct origin *(*find)(struct scoreboard *,
 994                                        struct commit *, struct origin *);
 995                 find = pass ? find_rename : find_origin;
 996
 997                 for (i = 0, parent = commit->parents;
 998                      i < MAXPARENT && parent;
 999                      parent = parent->next, i++) {
1000                         struct commit *p = parent->item;
1001                         int j, same;
1002
1003                         if (parent_origin[i])
1004                                 continue;
1005                         if (parse_commit(p))
1006                                 continue;
1007                         porigin = find(sb, p, origin);
1008                         if (!porigin)
1009                                 continue;
1010                         if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1011                                 pass_whole_blame(sb, origin, porigin);
1012                                 origin_decref(porigin);
1013                                 goto finish;
1014                         }
1015                         for (j = same = 0; j < i; j++)
1016                                 if (parent_origin[j] &&
1017                                     !hashcmp(parent_origin[j]->blob_sha1,
1018                                              porigin->blob_sha1)) {
1019                                         same = 1;
1020                                         break;
1021                                 }
1022                         if (!same)
1023                                 parent_origin[i] = porigin;
1024                         else
1025                                 origin_decref(porigin);
1026                 }
1027         }
1028
1029         num_commits++;
1030         for (i = 0, parent = commit->parents;
1031              i < MAXPARENT && parent;
1032              parent = parent->next, i++) {
1033                 struct origin *porigin = parent_origin[i];
1034                 if (!porigin)
1035                         continue;
1036                 if (pass_blame_to_parent(sb, origin, porigin))
1037                         goto finish;
1038         }
1039
1040         /*
1041          * Optionally run "miff" to find moves in parents' files here.
1042          */
1043         if (opt & PICKAXE_BLAME_MOVE)
1044                 for (i = 0, parent = commit->parents;
1045                      i < MAXPARENT && parent;
1046                      parent = parent->next, i++) {
1047                         struct origin *porigin = parent_origin[i];
1048                         if (!porigin)
1049                                 continue;
1050                         if (find_move_in_parent(sb, origin, porigin))
1051                                 goto finish;
1052                 }
1053
1054         /*
1055          * Optionally run "ciff" to find copies from parents' files here.
1056          */
1057         if (opt & PICKAXE_BLAME_COPY)
1058                 for (i = 0, parent = commit->parents;
1059                      i < MAXPARENT && parent;
1060                      parent = parent->next, i++) {
1061                         struct origin *porigin = parent_origin[i];
1062                         if (find_copy_in_parent(sb, origin, parent->item,
1063                                                 porigin, opt))
1064                                 goto finish;
1065                 }
1066
1067  finish:
1068         for (i = 0; i < MAXPARENT; i++)
1069                 origin_decref(parent_origin[i]);
1070 }
1071
1072 static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1073 {
1074         while (1) {
1075                 struct blame_entry *ent;
1076                 struct commit *commit;
1077                 struct origin *suspect = NULL;
1078
1079                 /* find one suspect to break down */
1080                 for (ent = sb->ent; !suspect && ent; ent = ent->next)
1081                         if (!ent->guilty)
1082                                 suspect = ent->suspect;
1083                 if (!suspect)
1084                         return; /* all done */
1085
1086                 origin_incref(suspect);
1087                 commit = suspect->commit;
1088                 if (!commit->object.parsed)
1089                         parse_commit(commit);
1090                 if (!(commit->object.flags & UNINTERESTING) &&
1091                     !(revs->max_age != -1 && commit->date  < revs->max_age))
1092                         pass_blame(sb, suspect, opt);
1093
1094                 /* Take responsibility for the remaining entries */
1095                 for (ent = sb->ent; ent; ent = ent->next)
1096                         if (!cmp_suspect(ent->suspect, suspect))
1097                                 ent->guilty = 1;
1098                 origin_decref(suspect);
1099
1100                 if (DEBUG) /* sanity */
1101                         sanity_check_refcnt(sb);
1102         }
1103 }
1104
1105 static const char *format_time(unsigned long time, const char *tz_str,
1106                                int show_raw_time)
1107 {
1108         static char time_buf[128];
1109         time_t t = time;
1110         int minutes, tz;
1111         struct tm *tm;
1112
1113         if (show_raw_time) {
1114                 sprintf(time_buf, "%lu %s", time, tz_str);
1115                 return time_buf;
1116         }
1117
1118         tz = atoi(tz_str);
1119         minutes = tz < 0 ? -tz : tz;
1120         minutes = (minutes / 100)*60 + (minutes % 100);
1121         minutes = tz < 0 ? -minutes : minutes;
1122         t = time + minutes * 60;
1123         tm = gmtime(&t);
1124
1125         strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1126         strcat(time_buf, tz_str);
1127         return time_buf;
1128 }
1129
1130 struct commit_info
1131 {
1132         char *author;
1133         char *author_mail;
1134         unsigned long author_time;
1135         char *author_tz;
1136
1137         /* filled only when asked for details */
1138         char *committer;
1139         char *committer_mail;
1140         unsigned long committer_time;
1141         char *committer_tz;
1142
1143         char *summary;
1144 };
1145
1146 static void get_ac_line(const char *inbuf, const char *what,
1147                         int bufsz, char *person, char **mail,
1148                         unsigned long *time, char **tz)
1149 {
1150         int len;
1151         char *tmp, *endp;
1152
1153         tmp = strstr(inbuf, what);
1154         if (!tmp)
1155                 goto error_out;
1156         tmp += strlen(what);
1157         endp = strchr(tmp, '\n');
1158         if (!endp)
1159                 len = strlen(tmp);
1160         else
1161                 len = endp - tmp;
1162         if (bufsz <= len) {
1163         error_out:
1164                 /* Ugh */
1165                 person = *mail = *tz = "(unknown)";
1166                 *time = 0;
1167                 return;
1168         }
1169         memcpy(person, tmp, len);
1170
1171         tmp = person;
1172         tmp += len;
1173         *tmp = 0;
1174         while (*tmp != ' ')
1175                 tmp--;
1176         *tz = tmp+1;
1177
1178         *tmp = 0;
1179         while (*tmp != ' ')
1180                 tmp--;
1181         *time = strtoul(tmp, NULL, 10);
1182
1183         *tmp = 0;
1184         while (*tmp != ' ')
1185                 tmp--;
1186         *mail = tmp + 1;
1187         *tmp = 0;
1188 }
1189
1190 static void get_commit_info(struct commit *commit,
1191                             struct commit_info *ret,
1192                             int detailed)
1193 {
1194         int len;
1195         char *tmp, *endp;
1196         static char author_buf[1024];
1197         static char committer_buf[1024];
1198         static char summary_buf[1024];
1199
1200         /* We've operated without save_commit_buffer, so
1201          * we now need to populate them for output.
1202          */
1203         if (!commit->buffer) {
1204                 char type[20];
1205                 unsigned long size;
1206                 commit->buffer =
1207                         read_sha1_file(commit->object.sha1, type, &size);
1208         }
1209         ret->author = author_buf;
1210         get_ac_line(commit->buffer, "\nauthor ",
1211                     sizeof(author_buf), author_buf, &ret->author_mail,
1212                     &ret->author_time, &ret->author_tz);
1213
1214         if (!detailed)
1215                 return;
1216
1217         ret->committer = committer_buf;
1218         get_ac_line(commit->buffer, "\ncommitter ",
1219                     sizeof(committer_buf), committer_buf, &ret->committer_mail,
1220                     &ret->committer_time, &ret->committer_tz);
1221
1222         ret->summary = summary_buf;
1223         tmp = strstr(commit->buffer, "\n\n");
1224         if (!tmp) {
1225         error_out:
1226                 sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1227                 return;
1228         }
1229         tmp += 2;
1230         endp = strchr(tmp, '\n');
1231         if (!endp)
1232                 goto error_out;
1233         len = endp - tmp;
1234         if (len >= sizeof(summary_buf))
1235                 goto error_out;
1236         memcpy(summary_buf, tmp, len);
1237         summary_buf[len] = 0;
1238 }
1239
1240 #define OUTPUT_ANNOTATE_COMPAT  001
1241 #define OUTPUT_LONG_OBJECT_NAME 002
1242 #define OUTPUT_RAW_TIMESTAMP    004
1243 #define OUTPUT_PORCELAIN        010
1244 #define OUTPUT_SHOW_NAME        020
1245 #define OUTPUT_SHOW_NUMBER      040
1246 #define OUTPUT_SHOW_SCORE      0100
1247
1248 static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1249 {
1250         int cnt;
1251         const char *cp;
1252         struct origin *suspect = ent->suspect;
1253         char hex[41];
1254
1255         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1256         printf("%s%c%d %d %d\n",
1257                hex,
1258                ent->guilty ? ' ' : '*', // purely for debugging
1259                ent->s_lno + 1,
1260                ent->lno + 1,
1261                ent->num_lines);
1262         if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1263                 struct commit_info ci;
1264                 suspect->commit->object.flags |= METAINFO_SHOWN;
1265                 get_commit_info(suspect->commit, &ci, 1);
1266                 printf("author %s\n", ci.author);
1267                 printf("author-mail %s\n", ci.author_mail);
1268                 printf("author-time %lu\n", ci.author_time);
1269                 printf("author-tz %s\n", ci.author_tz);
1270                 printf("committer %s\n", ci.committer);
1271                 printf("committer-mail %s\n", ci.committer_mail);
1272                 printf("committer-time %lu\n", ci.committer_time);
1273                 printf("committer-tz %s\n", ci.committer_tz);
1274                 printf("filename %s\n", suspect->path);
1275                 printf("summary %s\n", ci.summary);
1276         }
1277         else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1278                 printf("filename %s\n", suspect->path);
1279
1280         cp = nth_line(sb, ent->lno);
1281         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1282                 char ch;
1283                 if (cnt)
1284                         printf("%s %d %d\n", hex,
1285                                ent->s_lno + 1 + cnt,
1286                                ent->lno + 1 + cnt);
1287                 putchar('\t');
1288                 do {
1289                         ch = *cp++;
1290                         putchar(ch);
1291                 } while (ch != '\n' &&
1292                          cp < sb->final_buf + sb->final_buf_size);
1293         }
1294 }
1295
1296 static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1297 {
1298         int cnt;
1299         const char *cp;
1300         struct origin *suspect = ent->suspect;
1301         struct commit_info ci;
1302         char hex[41];
1303         int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1304
1305         get_commit_info(suspect->commit, &ci, 1);
1306         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1307
1308         cp = nth_line(sb, ent->lno);
1309         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1310                 char ch;
1311
1312                 printf("%.*s", (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8, hex);
1313                 if (opt & OUTPUT_ANNOTATE_COMPAT)
1314                         printf("\t(%10s\t%10s\t%d)", ci.author,
1315                                format_time(ci.author_time, ci.author_tz,
1316                                            show_raw_time),
1317                                ent->lno + 1 + cnt);
1318                 else {
1319                         if (opt & OUTPUT_SHOW_SCORE)
1320                                 printf(" %*d %02d",
1321                                        max_score_digits, ent->score,
1322                                        ent->suspect->refcnt);
1323                         if (opt & OUTPUT_SHOW_NAME)
1324                                 printf(" %-*.*s", longest_file, longest_file,
1325                                        suspect->path);
1326                         if (opt & OUTPUT_SHOW_NUMBER)
1327                                 printf(" %*d", max_orig_digits,
1328                                        ent->s_lno + 1 + cnt);
1329                         printf(" (%-*.*s %10s %*d) ",
1330                                longest_author, longest_author, ci.author,
1331                                format_time(ci.author_time, ci.author_tz,
1332                                            show_raw_time),
1333                                max_digits, ent->lno + 1 + cnt);
1334                 }
1335                 do {
1336                         ch = *cp++;
1337                         putchar(ch);
1338                 } while (ch != '\n' &&
1339                          cp < sb->final_buf + sb->final_buf_size);
1340         }
1341 }
1342
1343 static void output(struct scoreboard *sb, int option)
1344 {
1345         struct blame_entry *ent;
1346
1347         if (option & OUTPUT_PORCELAIN) {
1348                 for (ent = sb->ent; ent; ent = ent->next) {
1349                         struct blame_entry *oth;
1350                         struct origin *suspect = ent->suspect;
1351                         struct commit *commit = suspect->commit;
1352                         if (commit->object.flags & MORE_THAN_ONE_PATH)
1353                                 continue;
1354                         for (oth = ent->next; oth; oth = oth->next) {
1355                                 if ((oth->suspect->commit != commit) ||
1356                                     !strcmp(oth->suspect->path, suspect->path))
1357                                         continue;
1358                                 commit->object.flags |= MORE_THAN_ONE_PATH;
1359                                 break;
1360                         }
1361                 }
1362         }
1363
1364         for (ent = sb->ent; ent; ent = ent->next) {
1365                 if (option & OUTPUT_PORCELAIN)
1366                         emit_porcelain(sb, ent);
1367                 else {
1368                         emit_other(sb, ent, option);
1369                 }
1370         }
1371 }
1372
1373 static int prepare_lines(struct scoreboard *sb)
1374 {
1375         const char *buf = sb->final_buf;
1376         unsigned long len = sb->final_buf_size;
1377         int num = 0, incomplete = 0, bol = 1;
1378
1379         if (len && buf[len-1] != '\n')
1380                 incomplete++; /* incomplete line at the end */
1381         while (len--) {
1382                 if (bol) {
1383                         sb->lineno = xrealloc(sb->lineno,
1384                                               sizeof(int* ) * (num + 1));
1385                         sb->lineno[num] = buf - sb->final_buf;
1386                         bol = 0;
1387                 }
1388                 if (*buf++ == '\n') {
1389                         num++;
1390                         bol = 1;
1391                 }
1392         }
1393         sb->lineno = xrealloc(sb->lineno,
1394                               sizeof(int* ) * (num + incomplete + 1));
1395         sb->lineno[num + incomplete] = buf - sb->final_buf;
1396         sb->num_lines = num + incomplete;
1397         return sb->num_lines;
1398 }
1399
1400 static int read_ancestry(const char *graft_file)
1401 {
1402         FILE *fp = fopen(graft_file, "r");
1403         char buf[1024];
1404         if (!fp)
1405                 return -1;
1406         while (fgets(buf, sizeof(buf), fp)) {
1407                 /* The format is just "Commit Parent1 Parent2 ...\n" */
1408                 int len = strlen(buf);
1409                 struct commit_graft *graft = read_graft_line(buf, len);
1410                 if (graft)
1411                         register_commit_graft(graft, 0);
1412         }
1413         fclose(fp);
1414         return 0;
1415 }
1416
1417 static int lineno_width(int lines)
1418 {
1419         int i, width;
1420
1421         for (width = 1, i = 10; i <= lines + 1; width++)
1422                 i *= 10;
1423         return width;
1424 }
1425
1426 static void find_alignment(struct scoreboard *sb, int *option)
1427 {
1428         int longest_src_lines = 0;
1429         int longest_dst_lines = 0;
1430         unsigned largest_score = 0;
1431         struct blame_entry *e;
1432
1433         for (e = sb->ent; e; e = e->next) {
1434                 struct origin *suspect = e->suspect;
1435                 struct commit_info ci;
1436                 int num;
1437
1438                 if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1439                         suspect->commit->object.flags |= METAINFO_SHOWN;
1440                         get_commit_info(suspect->commit, &ci, 1);
1441                         if (strcmp(suspect->path, sb->path))
1442                                 *option |= OUTPUT_SHOW_NAME;
1443                         num = strlen(suspect->path);
1444                         if (longest_file < num)
1445                                 longest_file = num;
1446                         num = strlen(ci.author);
1447                         if (longest_author < num)
1448                                 longest_author = num;
1449                 }
1450                 num = e->s_lno + e->num_lines;
1451                 if (longest_src_lines < num)
1452                         longest_src_lines = num;
1453                 num = e->lno + e->num_lines;
1454                 if (longest_dst_lines < num)
1455                         longest_dst_lines = num;
1456                 if (largest_score < ent_score(sb, e))
1457                         largest_score = ent_score(sb, e);
1458         }
1459         max_orig_digits = lineno_width(longest_src_lines);
1460         max_digits = lineno_width(longest_dst_lines);
1461         max_score_digits = lineno_width(largest_score);
1462 }
1463
1464 static void sanity_check_refcnt(struct scoreboard *sb)
1465 {
1466         int baa = 0;
1467         struct blame_entry *ent;
1468
1469         for (ent = sb->ent; ent; ent = ent->next) {
1470                 /* Nobody should have zero or negative refcnt */
1471                 if (ent->suspect->refcnt <= 0) {
1472                         fprintf(stderr, "%s in %s has negative refcnt %d\n",
1473                                 ent->suspect->path,
1474                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1475                                 ent->suspect->refcnt);
1476                         baa = 1;
1477                 }
1478         }
1479         for (ent = sb->ent; ent; ent = ent->next) {
1480                 /* Mark the ones that haven't been checked */
1481                 if (0 < ent->suspect->refcnt)
1482                         ent->suspect->refcnt = -ent->suspect->refcnt;
1483         }
1484         for (ent = sb->ent; ent; ent = ent->next) {
1485                 /* then pick each and see if they have the the correct
1486                  * refcnt.
1487                  */
1488                 int found;
1489                 struct blame_entry *e;
1490                 struct origin *suspect = ent->suspect;
1491
1492                 if (0 < suspect->refcnt)
1493                         continue;
1494                 suspect->refcnt = -suspect->refcnt; /* Unmark */
1495                 for (found = 0, e = sb->ent; e; e = e->next) {
1496                         if (e->suspect != suspect)
1497                                 continue;
1498                         found++;
1499                 }
1500                 if (suspect->refcnt != found) {
1501                         fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1502                                 ent->suspect->path,
1503                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1504                                 ent->suspect->refcnt, found);
1505                         baa = 2;
1506                 }
1507         }
1508         if (baa) {
1509                 int opt = 0160;
1510                 find_alignment(sb, &opt);
1511                 output(sb, opt);
1512                 die("Baa %d!", baa);
1513         }
1514 }
1515
1516 static int has_path_in_work_tree(const char *path)
1517 {
1518         struct stat st;
1519         return !lstat(path, &st);
1520 }
1521
1522 static unsigned parse_score(const char *arg)
1523 {
1524         char *end;
1525         unsigned long score = strtoul(arg, &end, 10);
1526         if (*end)
1527                 return 0;
1528         return score;
1529 }
1530
1531 static const char *add_prefix(const char *prefix, const char *path)
1532 {
1533         if (!prefix || !prefix[0])
1534                 return path;
1535         return prefix_path(prefix, strlen(prefix), path);
1536 }
1537
1538 static const char *parse_loc(const char *spec,
1539                              struct scoreboard *sb, long lno,
1540                              long begin, long *ret)
1541 {
1542         char *term;
1543         const char *line;
1544         long num;
1545         int reg_error;
1546         regex_t regexp;
1547         regmatch_t match[1];
1548
1549         /* Allow "-L <something>,+20" to mean starting at <something>
1550          * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1551          * <something>.
1552          */
1553         if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1554                 num = strtol(spec + 1, &term, 10);
1555                 if (term != spec + 1) {
1556                         if (spec[0] == '-')
1557                                 num = 0 - num;
1558                         if (0 < num)
1559                                 *ret = begin + num - 2;
1560                         else if (!num)
1561                                 *ret = begin;
1562                         else
1563                                 *ret = begin + num;
1564                         return term;
1565                 }
1566                 return spec;
1567         }
1568         num = strtol(spec, &term, 10);
1569         if (term != spec) {
1570                 *ret = num;
1571                 return term;
1572         }
1573         if (spec[0] != '/')
1574                 return spec;
1575
1576         /* it could be a regexp of form /.../ */
1577         for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1578                 if (*term == '\\')
1579                         term++;
1580         }
1581         if (*term != '/')
1582                 return spec;
1583
1584         /* try [spec+1 .. term-1] as regexp */
1585         *term = 0;
1586         begin--; /* input is in human terms */
1587         line = nth_line(sb, begin);
1588
1589         if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1590             !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1591                 const char *cp = line + match[0].rm_so;
1592                 const char *nline;
1593
1594                 while (begin++ < lno) {
1595                         nline = nth_line(sb, begin);
1596                         if (line <= cp && cp < nline)
1597                                 break;
1598                         line = nline;
1599                 }
1600                 *ret = begin;
1601                 regfree(&regexp);
1602                 *term++ = '/';
1603                 return term;
1604         }
1605         else {
1606                 char errbuf[1024];
1607                 regerror(reg_error, &regexp, errbuf, 1024);
1608                 die("-L parameter '%s': %s", spec + 1, errbuf);
1609         }
1610 }
1611
1612 static void prepare_blame_range(struct scoreboard *sb,
1613                                 const char *bottomtop,
1614                                 long lno,
1615                                 long *bottom, long *top)
1616 {
1617         const char *term;
1618
1619         term = parse_loc(bottomtop, sb, lno, 1, bottom);
1620         if (*term == ',') {
1621                 term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1622                 if (*term)
1623                         usage(blame_usage);
1624         }
1625         if (*term)
1626                 usage(blame_usage);
1627 }
1628
1629 int cmd_blame(int argc, const char **argv, const char *prefix)
1630 {
1631         struct rev_info revs;
1632         const char *path;
1633         struct scoreboard sb;
1634         struct origin *o;
1635         struct blame_entry *ent;
1636         int i, seen_dashdash, unk, opt;
1637         long bottom, top, lno;
1638         int output_option = 0;
1639         const char *revs_file = NULL;
1640         const char *final_commit_name = NULL;
1641         char type[10];
1642         const char *bottomtop = NULL;
1643
1644         save_commit_buffer = 0;
1645
1646         opt = 0;
1647         seen_dashdash = 0;
1648         for (unk = i = 1; i < argc; i++) {
1649                 const char *arg = argv[i];
1650                 if (*arg != '-')
1651                         break;
1652                 else if (!strcmp("-c", arg))
1653                         output_option |= OUTPUT_ANNOTATE_COMPAT;
1654                 else if (!strcmp("-t", arg))
1655                         output_option |= OUTPUT_RAW_TIMESTAMP;
1656                 else if (!strcmp("-l", arg))
1657                         output_option |= OUTPUT_LONG_OBJECT_NAME;
1658                 else if (!strcmp("-S", arg) && ++i < argc)
1659                         revs_file = argv[i];
1660                 else if (!strncmp("-M", arg, 2)) {
1661                         opt |= PICKAXE_BLAME_MOVE;
1662                         blame_move_score = parse_score(arg+2);
1663                 }
1664                 else if (!strncmp("-C", arg, 2)) {
1665                         if (opt & PICKAXE_BLAME_COPY)
1666                                 opt |= PICKAXE_BLAME_COPY_HARDER;
1667                         opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
1668                         blame_copy_score = parse_score(arg+2);
1669                 }
1670                 else if (!strncmp("-L", arg, 2)) {
1671                         if (!arg[2]) {
1672                                 if (++i >= argc)
1673                                         usage(blame_usage);
1674                                 arg = argv[i];
1675                         }
1676                         else
1677                                 arg += 2;
1678                         if (bottomtop)
1679                                 die("More than one '-L n,m' option given");
1680                         bottomtop = arg;
1681                 }
1682                 else if (!strcmp("--score-debug", arg))
1683                         output_option |= OUTPUT_SHOW_SCORE;
1684                 else if (!strcmp("-f", arg) ||
1685                          !strcmp("--show-name", arg))
1686                         output_option |= OUTPUT_SHOW_NAME;
1687                 else if (!strcmp("-n", arg) ||
1688                          !strcmp("--show-number", arg))
1689                         output_option |= OUTPUT_SHOW_NUMBER;
1690                 else if (!strcmp("-p", arg) ||
1691                          !strcmp("--porcelain", arg))
1692                         output_option |= OUTPUT_PORCELAIN;
1693                 else if (!strcmp("--", arg)) {
1694                         seen_dashdash = 1;
1695                         i++;
1696                         break;
1697                 }
1698                 else
1699                         argv[unk++] = arg;
1700         }
1701
1702         if (!blame_move_score)
1703                 blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
1704         if (!blame_copy_score)
1705                 blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
1706
1707         /* We have collected options unknown to us in argv[1..unk]
1708          * which are to be passed to revision machinery if we are
1709          * going to do the "bottom" procesing.
1710          *
1711          * The remaining are:
1712          *
1713          * (1) if seen_dashdash, its either
1714          *     "-options -- <path>" or
1715          *     "-options -- <path> <rev>".
1716          *     but the latter is allowed only if there is no
1717          *     options that we passed to revision machinery.
1718          *
1719          * (2) otherwise, we may have "--" somewhere later and
1720          *     might be looking at the first one of multiple 'rev'
1721          *     parameters (e.g. " master ^next ^maint -- path").
1722          *     See if there is a dashdash first, and give the
1723          *     arguments before that to revision machinery.
1724          *     After that there must be one 'path'.
1725          *
1726          * (3) otherwise, its one of the three:
1727          *     "-options <path> <rev>"
1728          *     "-options <rev> <path>"
1729          *     "-options <path>"
1730          *     but again the first one is allowed only if
1731          *     there is no options that we passed to revision
1732          *     machinery.
1733          */
1734
1735         if (seen_dashdash) {
1736                 /* (1) */
1737                 if (argc <= i)
1738                         usage(blame_usage);
1739                 path = add_prefix(prefix, argv[i]);
1740                 if (i + 1 == argc - 1) {
1741                         if (unk != 1)
1742                                 usage(blame_usage);
1743                         argv[unk++] = argv[i + 1];
1744                 }
1745                 else if (i + 1 != argc)
1746                         /* garbage at end */
1747                         usage(blame_usage);
1748         }
1749         else {
1750                 int j;
1751                 for (j = i; !seen_dashdash && j < argc; j++)
1752                         if (!strcmp(argv[j], "--"))
1753                                 seen_dashdash = j;
1754                 if (seen_dashdash) {
1755                         if (seen_dashdash + 1 != argc - 1)
1756                                 usage(blame_usage);
1757                         path = add_prefix(prefix, argv[seen_dashdash + 1]);
1758                         for (j = i; j < seen_dashdash; j++)
1759                                 argv[unk++] = argv[j];
1760                 }
1761                 else {
1762                         /* (3) */
1763                         path = add_prefix(prefix, argv[i]);
1764                         if (i + 1 == argc - 1) {
1765                                 final_commit_name = argv[i + 1];
1766
1767                                 /* if (unk == 1) we could be getting
1768                                  * old-style
1769                                  */
1770                                 if (unk == 1 && !has_path_in_work_tree(path)) {
1771                                         path = add_prefix(prefix, argv[i + 1]);
1772                                         final_commit_name = argv[i];
1773                                 }
1774                         }
1775                         else if (i != argc - 1)
1776                                 usage(blame_usage); /* garbage at end */
1777
1778                         if (!has_path_in_work_tree(path))
1779                                 die("cannot stat path %s: %s",
1780                                     path, strerror(errno));
1781                 }
1782         }
1783
1784         if (final_commit_name)
1785                 argv[unk++] = final_commit_name;
1786
1787         /* Now we got rev and path.  We do not want the path pruning
1788          * but we may want "bottom" processing.
1789          */
1790         argv[unk] = NULL;
1791
1792         init_revisions(&revs, NULL);
1793         setup_revisions(unk, argv, &revs, "HEAD");
1794         memset(&sb, 0, sizeof(sb));
1795
1796         /* There must be one and only one positive commit in the
1797          * revs->pending array.
1798          */
1799         for (i = 0; i < revs.pending.nr; i++) {
1800                 struct object *obj = revs.pending.objects[i].item;
1801                 if (obj->flags & UNINTERESTING)
1802                         continue;
1803                 while (obj->type == OBJ_TAG)
1804                         obj = deref_tag(obj, NULL, 0);
1805                 if (obj->type != OBJ_COMMIT)
1806                         die("Non commit %s?",
1807                             revs.pending.objects[i].name);
1808                 if (sb.final)
1809                         die("More than one commit to dig from %s and %s?",
1810                             revs.pending.objects[i].name,
1811                             final_commit_name);
1812                 sb.final = (struct commit *) obj;
1813                 final_commit_name = revs.pending.objects[i].name;
1814         }
1815
1816         if (!sb.final) {
1817                 /* "--not A B -- path" without anything positive */
1818                 unsigned char head_sha1[20];
1819
1820                 final_commit_name = "HEAD";
1821                 if (get_sha1(final_commit_name, head_sha1))
1822                         die("No such ref: HEAD");
1823                 sb.final = lookup_commit_reference(head_sha1);
1824                 add_pending_object(&revs, &(sb.final->object), "HEAD");
1825         }
1826
1827         /* If we have bottom, this will mark the ancestors of the
1828          * bottom commits we would reach while traversing as
1829          * uninteresting.
1830          */
1831         prepare_revision_walk(&revs);
1832
1833         o = get_origin(&sb, sb.final, path);
1834         if (fill_blob_sha1(o))
1835                 die("no such path %s in %s", path, final_commit_name);
1836
1837         sb.final_buf = read_sha1_file(o->blob_sha1, type, &sb.final_buf_size);
1838         num_read_blob++;
1839         lno = prepare_lines(&sb);
1840
1841         bottom = top = 0;
1842         if (bottomtop)
1843                 prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
1844         if (bottom && top && top < bottom) {
1845                 long tmp;
1846                 tmp = top; top = bottom; bottom = tmp;
1847         }
1848         if (bottom < 1)
1849                 bottom = 1;
1850         if (top < 1)
1851                 top = lno;
1852         bottom--;
1853         if (lno < top)
1854                 die("file %s has only %lu lines", path, lno);
1855
1856         ent = xcalloc(1, sizeof(*ent));
1857         ent->lno = bottom;
1858         ent->num_lines = top - bottom;
1859         ent->suspect = o;
1860         ent->s_lno = bottom;
1861
1862         sb.ent = ent;
1863         sb.path = path;
1864
1865         if (revs_file && read_ancestry(revs_file))
1866                 die("reading graft file %s failed: %s",
1867                     revs_file, strerror(errno));
1868
1869         assign_blame(&sb, &revs, opt);
1870
1871         coalesce(&sb);
1872
1873         if (!(output_option & OUTPUT_PORCELAIN))
1874                 find_alignment(&sb, &output_option);
1875
1876         output(&sb, output_option);
1877         free((void *)sb.final_buf);
1878         for (ent = sb.ent; ent; ) {
1879                 struct blame_entry *e = ent->next;
1880                 free(ent);
1881                 ent = e;
1882         }
1883
1884         if (DEBUG) {
1885                 printf("num read blob: %d\n", num_read_blob);
1886                 printf("num get patch: %d\n", num_get_patch);
1887                 printf("num commits: %d\n", num_commits);
1888         }
1889         return 0;
1890 }