builtin / blame.con commit Merge branch 'ab/aix-needs-compat-regex' (5cea6ff)
   1/*
   2 * Blame
   3 *
   4 * Copyright (c) 2006, 2014 by its authors
   5 * See COPYING for licensing conditions
   6 */
   7
   8#include "cache.h"
   9#include "refs.h"
  10#include "builtin.h"
  11#include "blob.h"
  12#include "commit.h"
  13#include "tag.h"
  14#include "tree-walk.h"
  15#include "diff.h"
  16#include "diffcore.h"
  17#include "revision.h"
  18#include "quote.h"
  19#include "xdiff-interface.h"
  20#include "cache-tree.h"
  21#include "string-list.h"
  22#include "mailmap.h"
  23#include "mergesort.h"
  24#include "parse-options.h"
  25#include "prio-queue.h"
  26#include "utf8.h"
  27#include "userdiff.h"
  28#include "line-range.h"
  29#include "line-log.h"
  30#include "dir.h"
  31#include "progress.h"
  32
  33static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");
  34
  35static const char *blame_opt_usage[] = {
  36        blame_usage,
  37        "",
  38        N_("<rev-opts> are documented in git-rev-list(1)"),
  39        NULL
  40};
  41
  42static int longest_file;
  43static int longest_author;
  44static int max_orig_digits;
  45static int max_digits;
  46static int max_score_digits;
  47static int show_root;
  48static int reverse;
  49static int blank_boundary;
  50static int incremental;
  51static int xdl_opts;
  52static int abbrev = -1;
  53static int no_whole_file_rename;
  54static int show_progress;
  55
  56static struct date_mode blame_date_mode = { DATE_ISO8601 };
  57static size_t blame_date_width;
  58
  59static struct string_list mailmap = STRING_LIST_INIT_NODUP;
  60
  61#ifndef DEBUG
  62#define DEBUG 0
  63#endif
  64
  65/* stats */
  66static int num_read_blob;
  67static int num_get_patch;
  68static int num_commits;
  69
  70#define PICKAXE_BLAME_MOVE              01
  71#define PICKAXE_BLAME_COPY              02
  72#define PICKAXE_BLAME_COPY_HARDER       04
  73#define PICKAXE_BLAME_COPY_HARDEST      010
  74
  75/*
  76 * blame for a blame_entry with score lower than these thresholds
  77 * is not passed to the parent using move/copy logic.
  78 */
  79static unsigned blame_move_score;
  80static unsigned blame_copy_score;
  81#define BLAME_DEFAULT_MOVE_SCORE        20
  82#define BLAME_DEFAULT_COPY_SCORE        40
  83
  84/* Remember to update object flag allocation in object.h */
  85#define METAINFO_SHOWN          (1u<<12)
  86#define MORE_THAN_ONE_PATH      (1u<<13)
  87
  88/*
  89 * One blob in a commit that is being suspected
  90 */
  91struct origin {
  92        int refcnt;
  93        /* Record preceding blame record for this blob */
  94        struct origin *previous;
  95        /* origins are put in a list linked via `next' hanging off the
  96         * corresponding commit's util field in order to make finding
  97         * them fast.  The presence in this chain does not count
  98         * towards the origin's reference count.  It is tempting to
  99         * let it count as long as the commit is pending examination,
 100         * but even under circumstances where the commit will be
 101         * present multiple times in the priority queue of unexamined
 102         * commits, processing the first instance will not leave any
 103         * work requiring the origin data for the second instance.  An
 104         * interspersed commit changing that would have to be
 105         * preexisting with a different ancestry and with the same
 106         * commit date in order to wedge itself between two instances
 107         * of the same commit in the priority queue _and_ produce
 108         * blame entries relevant for it.  While we don't want to let
 109         * us get tripped up by this case, it certainly does not seem
 110         * worth optimizing for.
 111         */
 112        struct origin *next;
 113        struct commit *commit;
 114        /* `suspects' contains blame entries that may be attributed to
 115         * this origin's commit or to parent commits.  When a commit
 116         * is being processed, all suspects will be moved, either by
 117         * assigning them to an origin in a different commit, or by
 118         * shipping them to the scoreboard's ent list because they
 119         * cannot be attributed to a different commit.
 120         */
 121        struct blame_entry *suspects;
 122        mmfile_t file;
 123        struct object_id blob_oid;
 124        unsigned mode;
 125        /* guilty gets set when shipping any suspects to the final
 126         * blame list instead of other commits
 127         */
 128        char guilty;
 129        char path[FLEX_ARRAY];
 130};
 131
 132struct progress_info {
 133        struct progress *progress;
 134        int blamed_lines;
 135};
 136
 137static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
 138                      xdl_emit_hunk_consume_func_t hunk_func, void *cb_data)
 139{
 140        xpparam_t xpp = {0};
 141        xdemitconf_t xecfg = {0};
 142        xdemitcb_t ecb = {NULL};
 143
 144        xpp.flags = xdl_opts;
 145        xecfg.hunk_func = hunk_func;
 146        ecb.priv = cb_data;
 147        return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
 148}
 149
 150/*
 151 * Prepare diff_filespec and convert it using diff textconv API
 152 * if the textconv driver exists.
 153 * Return 1 if the conversion succeeds, 0 otherwise.
 154 */
 155int textconv_object(const char *path,
 156                    unsigned mode,
 157                    const struct object_id *oid,
 158                    int oid_valid,
 159                    char **buf,
 160                    unsigned long *buf_size)
 161{
 162        struct diff_filespec *df;
 163        struct userdiff_driver *textconv;
 164
 165        df = alloc_filespec(path);
 166        fill_filespec(df, oid->hash, oid_valid, mode);
 167        textconv = get_textconv(df);
 168        if (!textconv) {
 169                free_filespec(df);
 170                return 0;
 171        }
 172
 173        *buf_size = fill_textconv(textconv, df, buf);
 174        free_filespec(df);
 175        return 1;
 176}
 177
 178/*
 179 * Given an origin, prepare mmfile_t structure to be used by the
 180 * diff machinery
 181 */
 182static void fill_origin_blob(struct diff_options *opt,
 183                             struct origin *o, mmfile_t *file)
 184{
 185        if (!o->file.ptr) {
 186                enum object_type type;
 187                unsigned long file_size;
 188
 189                num_read_blob++;
 190                if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
 191                    textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
 192                        ;
 193                else
 194                        file->ptr = read_sha1_file(o->blob_oid.hash, &type,
 195                                                   &file_size);
 196                file->size = file_size;
 197
 198                if (!file->ptr)
 199                        die("Cannot read blob %s for path %s",
 200                            oid_to_hex(&o->blob_oid),
 201                            o->path);
 202                o->file = *file;
 203        }
 204        else
 205                *file = o->file;
 206}
 207
 208/*
 209 * Origin is refcounted and usually we keep the blob contents to be
 210 * reused.
 211 */
 212static inline struct origin *origin_incref(struct origin *o)
 213{
 214        if (o)
 215                o->refcnt++;
 216        return o;
 217}
 218
 219static void origin_decref(struct origin *o)
 220{
 221        if (o && --o->refcnt <= 0) {
 222                struct origin *p, *l = NULL;
 223                if (o->previous)
 224                        origin_decref(o->previous);
 225                free(o->file.ptr);
 226                /* Should be present exactly once in commit chain */
 227                for (p = o->commit->util; p; l = p, p = p->next) {
 228                        if (p == o) {
 229                                if (l)
 230                                        l->next = p->next;
 231                                else
 232                                        o->commit->util = p->next;
 233                                free(o);
 234                                return;
 235                        }
 236                }
 237                die("internal error in blame::origin_decref");
 238        }
 239}
 240
 241static void drop_origin_blob(struct origin *o)
 242{
 243        if (o->file.ptr) {
 244                free(o->file.ptr);
 245                o->file.ptr = NULL;
 246        }
 247}
 248
 249/*
 250 * Each group of lines is described by a blame_entry; it can be split
 251 * as we pass blame to the parents.  They are arranged in linked lists
 252 * kept as `suspects' of some unprocessed origin, or entered (when the
 253 * blame origin has been finalized) into the scoreboard structure.
 254 * While the scoreboard structure is only sorted at the end of
 255 * processing (according to final image line number), the lists
 256 * attached to an origin are sorted by the target line number.
 257 */
 258struct blame_entry {
 259        struct blame_entry *next;
 260
 261        /* the first line of this group in the final image;
 262         * internally all line numbers are 0 based.
 263         */
 264        int lno;
 265
 266        /* how many lines this group has */
 267        int num_lines;
 268
 269        /* the commit that introduced this group into the final image */
 270        struct origin *suspect;
 271
 272        /* the line number of the first line of this group in the
 273         * suspect's file; internally all line numbers are 0 based.
 274         */
 275        int s_lno;
 276
 277        /* how significant this entry is -- cached to avoid
 278         * scanning the lines over and over.
 279         */
 280        unsigned score;
 281};
 282
 283/*
 284 * Any merge of blames happens on lists of blames that arrived via
 285 * different parents in a single suspect.  In this case, we want to
 286 * sort according to the suspect line numbers as opposed to the final
 287 * image line numbers.  The function body is somewhat longish because
 288 * it avoids unnecessary writes.
 289 */
 290
 291static struct blame_entry *blame_merge(struct blame_entry *list1,
 292                                       struct blame_entry *list2)
 293{
 294        struct blame_entry *p1 = list1, *p2 = list2,
 295                **tail = &list1;
 296
 297        if (!p1)
 298                return p2;
 299        if (!p2)
 300                return p1;
 301
 302        if (p1->s_lno <= p2->s_lno) {
 303                do {
 304                        tail = &p1->next;
 305                        if ((p1 = *tail) == NULL) {
 306                                *tail = p2;
 307                                return list1;
 308                        }
 309                } while (p1->s_lno <= p2->s_lno);
 310        }
 311        for (;;) {
 312                *tail = p2;
 313                do {
 314                        tail = &p2->next;
 315                        if ((p2 = *tail) == NULL)  {
 316                                *tail = p1;
 317                                return list1;
 318                        }
 319                } while (p1->s_lno > p2->s_lno);
 320                *tail = p1;
 321                do {
 322                        tail = &p1->next;
 323                        if ((p1 = *tail) == NULL) {
 324                                *tail = p2;
 325                                return list1;
 326                        }
 327                } while (p1->s_lno <= p2->s_lno);
 328        }
 329}
 330
 331static void *get_next_blame(const void *p)
 332{
 333        return ((struct blame_entry *)p)->next;
 334}
 335
 336static void set_next_blame(void *p1, void *p2)
 337{
 338        ((struct blame_entry *)p1)->next = p2;
 339}
 340
 341/*
 342 * Final image line numbers are all different, so we don't need a
 343 * three-way comparison here.
 344 */
 345
 346static int compare_blame_final(const void *p1, const void *p2)
 347{
 348        return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
 349                ? 1 : -1;
 350}
 351
 352static int compare_blame_suspect(const void *p1, const void *p2)
 353{
 354        const struct blame_entry *s1 = p1, *s2 = p2;
 355        /*
 356         * to allow for collating suspects, we sort according to the
 357         * respective pointer value as the primary sorting criterion.
 358         * The actual relation is pretty unimportant as long as it
 359         * establishes a total order.  Comparing as integers gives us
 360         * that.
 361         */
 362        if (s1->suspect != s2->suspect)
 363                return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
 364        if (s1->s_lno == s2->s_lno)
 365                return 0;
 366        return s1->s_lno > s2->s_lno ? 1 : -1;
 367}
 368
 369static struct blame_entry *blame_sort(struct blame_entry *head,
 370                                      int (*compare_fn)(const void *, const void *))
 371{
 372        return llist_mergesort (head, get_next_blame, set_next_blame, compare_fn);
 373}
 374
 375static int compare_commits_by_reverse_commit_date(const void *a,
 376                                                  const void *b,
 377                                                  void *c)
 378{
 379        return -compare_commits_by_commit_date(a, b, c);
 380}
 381
 382/*
 383 * The current state of the blame assignment.
 384 */
 385struct scoreboard {
 386        /* the final commit (i.e. where we started digging from) */
 387        struct commit *final;
 388        /* Priority queue for commits with unassigned blame records */
 389        struct prio_queue commits;
 390        struct rev_info *revs;
 391        const char *path;
 392
 393        /*
 394         * The contents in the final image.
 395         * Used by many functions to obtain contents of the nth line,
 396         * indexed with scoreboard.lineno[blame_entry.lno].
 397         */
 398        const char *final_buf;
 399        unsigned long final_buf_size;
 400
 401        /* linked list of blames */
 402        struct blame_entry *ent;
 403
 404        /* look-up a line in the final buffer */
 405        int num_lines;
 406        int *lineno;
 407};
 408
 409static void sanity_check_refcnt(struct scoreboard *);
 410
 411/*
 412 * If two blame entries that are next to each other came from
 413 * contiguous lines in the same origin (i.e. <commit, path> pair),
 414 * merge them together.
 415 */
 416static void coalesce(struct scoreboard *sb)
 417{
 418        struct blame_entry *ent, *next;
 419
 420        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 421                if (ent->suspect == next->suspect &&
 422                    ent->s_lno + ent->num_lines == next->s_lno) {
 423                        ent->num_lines += next->num_lines;
 424                        ent->next = next->next;
 425                        origin_decref(next->suspect);
 426                        free(next);
 427                        ent->score = 0;
 428                        next = ent; /* again */
 429                }
 430        }
 431
 432        if (DEBUG) /* sanity */
 433                sanity_check_refcnt(sb);
 434}
 435
 436/*
 437 * Merge the given sorted list of blames into a preexisting origin.
 438 * If there were no previous blames to that commit, it is entered into
 439 * the commit priority queue of the score board.
 440 */
 441
 442static void queue_blames(struct scoreboard *sb, struct origin *porigin,
 443                         struct blame_entry *sorted)
 444{
 445        if (porigin->suspects)
 446                porigin->suspects = blame_merge(porigin->suspects, sorted);
 447        else {
 448                struct origin *o;
 449                for (o = porigin->commit->util; o; o = o->next) {
 450                        if (o->suspects) {
 451                                porigin->suspects = sorted;
 452                                return;
 453                        }
 454                }
 455                porigin->suspects = sorted;
 456                prio_queue_put(&sb->commits, porigin->commit);
 457        }
 458}
 459
 460/*
 461 * Given a commit and a path in it, create a new origin structure.
 462 * The callers that add blame to the scoreboard should use
 463 * get_origin() to obtain shared, refcounted copy instead of calling
 464 * this function directly.
 465 */
 466static struct origin *make_origin(struct commit *commit, const char *path)
 467{
 468        struct origin *o;
 469        FLEX_ALLOC_STR(o, path, path);
 470        o->commit = commit;
 471        o->refcnt = 1;
 472        o->next = commit->util;
 473        commit->util = o;
 474        return o;
 475}
 476
 477/*
 478 * Locate an existing origin or create a new one.
 479 * This moves the origin to front position in the commit util list.
 480 */
 481static struct origin *get_origin(struct scoreboard *sb,
 482                                 struct commit *commit,
 483                                 const char *path)
 484{
 485        struct origin *o, *l;
 486
 487        for (o = commit->util, l = NULL; o; l = o, o = o->next) {
 488                if (!strcmp(o->path, path)) {
 489                        /* bump to front */
 490                        if (l) {
 491                                l->next = o->next;
 492                                o->next = commit->util;
 493                                commit->util = o;
 494                        }
 495                        return origin_incref(o);
 496                }
 497        }
 498        return make_origin(commit, path);
 499}
 500
 501/*
 502 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 503 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 504 * for an origin is also used to pass the blame for the entire file to
 505 * the parent to detect the case where a child's blob is identical to
 506 * that of its parent's.
 507 *
 508 * This also fills origin->mode for corresponding tree path.
 509 */
 510static int fill_blob_sha1_and_mode(struct origin *origin)
 511{
 512        if (!is_null_oid(&origin->blob_oid))
 513                return 0;
 514        if (get_tree_entry(origin->commit->object.oid.hash,
 515                           origin->path,
 516                           origin->blob_oid.hash, &origin->mode))
 517                goto error_out;
 518        if (sha1_object_info(origin->blob_oid.hash, NULL) != OBJ_BLOB)
 519                goto error_out;
 520        return 0;
 521 error_out:
 522        oidclr(&origin->blob_oid);
 523        origin->mode = S_IFINVALID;
 524        return -1;
 525}
 526
 527/*
 528 * We have an origin -- check if the same path exists in the
 529 * parent and return an origin structure to represent it.
 530 */
 531static struct origin *find_origin(struct scoreboard *sb,
 532                                  struct commit *parent,
 533                                  struct origin *origin)
 534{
 535        struct origin *porigin;
 536        struct diff_options diff_opts;
 537        const char *paths[2];
 538
 539        /* First check any existing origins */
 540        for (porigin = parent->util; porigin; porigin = porigin->next)
 541                if (!strcmp(porigin->path, origin->path)) {
 542                        /*
 543                         * The same path between origin and its parent
 544                         * without renaming -- the most common case.
 545                         */
 546                        return origin_incref (porigin);
 547                }
 548
 549        /* See if the origin->path is different between parent
 550         * and origin first.  Most of the time they are the
 551         * same and diff-tree is fairly efficient about this.
 552         */
 553        diff_setup(&diff_opts);
 554        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 555        diff_opts.detect_rename = 0;
 556        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 557        paths[0] = origin->path;
 558        paths[1] = NULL;
 559
 560        parse_pathspec(&diff_opts.pathspec,
 561                       PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
 562                       PATHSPEC_LITERAL_PATH, "", paths);
 563        diff_setup_done(&diff_opts);
 564
 565        if (is_null_oid(&origin->commit->object.oid))
 566                do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
 567        else
 568                diff_tree_sha1(parent->tree->object.oid.hash,
 569                               origin->commit->tree->object.oid.hash,
 570                               "", &diff_opts);
 571        diffcore_std(&diff_opts);
 572
 573        if (!diff_queued_diff.nr) {
 574                /* The path is the same as parent */
 575                porigin = get_origin(sb, parent, origin->path);
 576                oidcpy(&porigin->blob_oid, &origin->blob_oid);
 577                porigin->mode = origin->mode;
 578        } else {
 579                /*
 580                 * Since origin->path is a pathspec, if the parent
 581                 * commit had it as a directory, we will see a whole
 582                 * bunch of deletion of files in the directory that we
 583                 * do not care about.
 584                 */
 585                int i;
 586                struct diff_filepair *p = NULL;
 587                for (i = 0; i < diff_queued_diff.nr; i++) {
 588                        const char *name;
 589                        p = diff_queued_diff.queue[i];
 590                        name = p->one->path ? p->one->path : p->two->path;
 591                        if (!strcmp(name, origin->path))
 592                                break;
 593                }
 594                if (!p)
 595                        die("internal error in blame::find_origin");
 596                switch (p->status) {
 597                default:
 598                        die("internal error in blame::find_origin (%c)",
 599                            p->status);
 600                case 'M':
 601                        porigin = get_origin(sb, parent, origin->path);
 602                        oidcpy(&porigin->blob_oid, &p->one->oid);
 603                        porigin->mode = p->one->mode;
 604                        break;
 605                case 'A':
 606                case 'T':
 607                        /* Did not exist in parent, or type changed */
 608                        break;
 609                }
 610        }
 611        diff_flush(&diff_opts);
 612        clear_pathspec(&diff_opts.pathspec);
 613        return porigin;
 614}
 615
 616/*
 617 * We have an origin -- find the path that corresponds to it in its
 618 * parent and return an origin structure to represent it.
 619 */
 620static struct origin *find_rename(struct scoreboard *sb,
 621                                  struct commit *parent,
 622                                  struct origin *origin)
 623{
 624        struct origin *porigin = NULL;
 625        struct diff_options diff_opts;
 626        int i;
 627
 628        diff_setup(&diff_opts);
 629        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 630        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 631        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 632        diff_opts.single_follow = origin->path;
 633        diff_setup_done(&diff_opts);
 634
 635        if (is_null_oid(&origin->commit->object.oid))
 636                do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
 637        else
 638                diff_tree_sha1(parent->tree->object.oid.hash,
 639                               origin->commit->tree->object.oid.hash,
 640                               "", &diff_opts);
 641        diffcore_std(&diff_opts);
 642
 643        for (i = 0; i < diff_queued_diff.nr; i++) {
 644                struct diff_filepair *p = diff_queued_diff.queue[i];
 645                if ((p->status == 'R' || p->status == 'C') &&
 646                    !strcmp(p->two->path, origin->path)) {
 647                        porigin = get_origin(sb, parent, p->one->path);
 648                        oidcpy(&porigin->blob_oid, &p->one->oid);
 649                        porigin->mode = p->one->mode;
 650                        break;
 651                }
 652        }
 653        diff_flush(&diff_opts);
 654        clear_pathspec(&diff_opts.pathspec);
 655        return porigin;
 656}
 657
 658/*
 659 * Append a new blame entry to a given output queue.
 660 */
 661static void add_blame_entry(struct blame_entry ***queue,
 662                            const struct blame_entry *src)
 663{
 664        struct blame_entry *e = xmalloc(sizeof(*e));
 665        memcpy(e, src, sizeof(*e));
 666        origin_incref(e->suspect);
 667
 668        e->next = **queue;
 669        **queue = e;
 670        *queue = &e->next;
 671}
 672
 673/*
 674 * src typically is on-stack; we want to copy the information in it to
 675 * a malloced blame_entry that gets added to the given queue.  The
 676 * origin of dst loses a refcnt.
 677 */
 678static void dup_entry(struct blame_entry ***queue,
 679                      struct blame_entry *dst, struct blame_entry *src)
 680{
 681        origin_incref(src->suspect);
 682        origin_decref(dst->suspect);
 683        memcpy(dst, src, sizeof(*src));
 684        dst->next = **queue;
 685        **queue = dst;
 686        *queue = &dst->next;
 687}
 688
 689static const char *nth_line(struct scoreboard *sb, long lno)
 690{
 691        return sb->final_buf + sb->lineno[lno];
 692}
 693
 694static const char *nth_line_cb(void *data, long lno)
 695{
 696        return nth_line((struct scoreboard *)data, lno);
 697}
 698
 699/*
 700 * It is known that lines between tlno to same came from parent, and e
 701 * has an overlap with that range.  it also is known that parent's
 702 * line plno corresponds to e's line tlno.
 703 *
 704 *                <---- e ----->
 705 *                   <------>
 706 *                   <------------>
 707 *             <------------>
 708 *             <------------------>
 709 *
 710 * Split e into potentially three parts; before this chunk, the chunk
 711 * to be blamed for the parent, and after that portion.
 712 */
 713static void split_overlap(struct blame_entry *split,
 714                          struct blame_entry *e,
 715                          int tlno, int plno, int same,
 716                          struct origin *parent)
 717{
 718        int chunk_end_lno;
 719        memset(split, 0, sizeof(struct blame_entry [3]));
 720
 721        if (e->s_lno < tlno) {
 722                /* there is a pre-chunk part not blamed on parent */
 723                split[0].suspect = origin_incref(e->suspect);
 724                split[0].lno = e->lno;
 725                split[0].s_lno = e->s_lno;
 726                split[0].num_lines = tlno - e->s_lno;
 727                split[1].lno = e->lno + tlno - e->s_lno;
 728                split[1].s_lno = plno;
 729        }
 730        else {
 731                split[1].lno = e->lno;
 732                split[1].s_lno = plno + (e->s_lno - tlno);
 733        }
 734
 735        if (same < e->s_lno + e->num_lines) {
 736                /* there is a post-chunk part not blamed on parent */
 737                split[2].suspect = origin_incref(e->suspect);
 738                split[2].lno = e->lno + (same - e->s_lno);
 739                split[2].s_lno = e->s_lno + (same - e->s_lno);
 740                split[2].num_lines = e->s_lno + e->num_lines - same;
 741                chunk_end_lno = split[2].lno;
 742        }
 743        else
 744                chunk_end_lno = e->lno + e->num_lines;
 745        split[1].num_lines = chunk_end_lno - split[1].lno;
 746
 747        /*
 748         * if it turns out there is nothing to blame the parent for,
 749         * forget about the splitting.  !split[1].suspect signals this.
 750         */
 751        if (split[1].num_lines < 1)
 752                return;
 753        split[1].suspect = origin_incref(parent);
 754}
 755
 756/*
 757 * split_overlap() divided an existing blame e into up to three parts
 758 * in split.  Any assigned blame is moved to queue to
 759 * reflect the split.
 760 */
 761static void split_blame(struct blame_entry ***blamed,
 762                        struct blame_entry ***unblamed,
 763                        struct blame_entry *split,
 764                        struct blame_entry *e)
 765{
 766        if (split[0].suspect && split[2].suspect) {
 767                /* The first part (reuse storage for the existing entry e) */
 768                dup_entry(unblamed, e, &split[0]);
 769
 770                /* The last part -- me */
 771                add_blame_entry(unblamed, &split[2]);
 772
 773                /* ... and the middle part -- parent */
 774                add_blame_entry(blamed, &split[1]);
 775        }
 776        else if (!split[0].suspect && !split[2].suspect)
 777                /*
 778                 * The parent covers the entire area; reuse storage for
 779                 * e and replace it with the parent.
 780                 */
 781                dup_entry(blamed, e, &split[1]);
 782        else if (split[0].suspect) {
 783                /* me and then parent */
 784                dup_entry(unblamed, e, &split[0]);
 785                add_blame_entry(blamed, &split[1]);
 786        }
 787        else {
 788                /* parent and then me */
 789                dup_entry(blamed, e, &split[1]);
 790                add_blame_entry(unblamed, &split[2]);
 791        }
 792}
 793
 794/*
 795 * After splitting the blame, the origins used by the
 796 * on-stack blame_entry should lose one refcnt each.
 797 */
 798static void decref_split(struct blame_entry *split)
 799{
 800        int i;
 801
 802        for (i = 0; i < 3; i++)
 803                origin_decref(split[i].suspect);
 804}
 805
 806/*
 807 * reverse_blame reverses the list given in head, appending tail.
 808 * That allows us to build lists in reverse order, then reverse them
 809 * afterwards.  This can be faster than building the list in proper
 810 * order right away.  The reason is that building in proper order
 811 * requires writing a link in the _previous_ element, while building
 812 * in reverse order just requires placing the list head into the
 813 * _current_ element.
 814 */
 815
 816static struct blame_entry *reverse_blame(struct blame_entry *head,
 817                                         struct blame_entry *tail)
 818{
 819        while (head) {
 820                struct blame_entry *next = head->next;
 821                head->next = tail;
 822                tail = head;
 823                head = next;
 824        }
 825        return tail;
 826}
 827
 828/*
 829 * Process one hunk from the patch between the current suspect for
 830 * blame_entry e and its parent.  This first blames any unfinished
 831 * entries before the chunk (which is where target and parent start
 832 * differing) on the parent, and then splits blame entries at the
 833 * start and at the end of the difference region.  Since use of -M and
 834 * -C options may lead to overlapping/duplicate source line number
 835 * ranges, all we can rely on from sorting/merging is the order of the
 836 * first suspect line number.
 837 */
 838static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
 839                        int tlno, int offset, int same,
 840                        struct origin *parent)
 841{
 842        struct blame_entry *e = **srcq;
 843        struct blame_entry *samep = NULL, *diffp = NULL;
 844
 845        while (e && e->s_lno < tlno) {
 846                struct blame_entry *next = e->next;
 847                /*
 848                 * current record starts before differing portion.  If
 849                 * it reaches into it, we need to split it up and
 850                 * examine the second part separately.
 851                 */
 852                if (e->s_lno + e->num_lines > tlno) {
 853                        /* Move second half to a new record */
 854                        int len = tlno - e->s_lno;
 855                        struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
 856                        n->suspect = e->suspect;
 857                        n->lno = e->lno + len;
 858                        n->s_lno = e->s_lno + len;
 859                        n->num_lines = e->num_lines - len;
 860                        e->num_lines = len;
 861                        e->score = 0;
 862                        /* Push new record to diffp */
 863                        n->next = diffp;
 864                        diffp = n;
 865                } else
 866                        origin_decref(e->suspect);
 867                /* Pass blame for everything before the differing
 868                 * chunk to the parent */
 869                e->suspect = origin_incref(parent);
 870                e->s_lno += offset;
 871                e->next = samep;
 872                samep = e;
 873                e = next;
 874        }
 875        /*
 876         * As we don't know how much of a common stretch after this
 877         * diff will occur, the currently blamed parts are all that we
 878         * can assign to the parent for now.
 879         */
 880
 881        if (samep) {
 882                **dstq = reverse_blame(samep, **dstq);
 883                *dstq = &samep->next;
 884        }
 885        /*
 886         * Prepend the split off portions: everything after e starts
 887         * after the blameable portion.
 888         */
 889        e = reverse_blame(diffp, e);
 890
 891        /*
 892         * Now retain records on the target while parts are different
 893         * from the parent.
 894         */
 895        samep = NULL;
 896        diffp = NULL;
 897        while (e && e->s_lno < same) {
 898                struct blame_entry *next = e->next;
 899
 900                /*
 901                 * If current record extends into sameness, need to split.
 902                 */
 903                if (e->s_lno + e->num_lines > same) {
 904                        /*
 905                         * Move second half to a new record to be
 906                         * processed by later chunks
 907                         */
 908                        int len = same - e->s_lno;
 909                        struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
 910                        n->suspect = origin_incref(e->suspect);
 911                        n->lno = e->lno + len;
 912                        n->s_lno = e->s_lno + len;
 913                        n->num_lines = e->num_lines - len;
 914                        e->num_lines = len;
 915                        e->score = 0;
 916                        /* Push new record to samep */
 917                        n->next = samep;
 918                        samep = n;
 919                }
 920                e->next = diffp;
 921                diffp = e;
 922                e = next;
 923        }
 924        **srcq = reverse_blame(diffp, reverse_blame(samep, e));
 925        /* Move across elements that are in the unblamable portion */
 926        if (diffp)
 927                *srcq = &diffp->next;
 928}
 929
 930struct blame_chunk_cb_data {
 931        struct origin *parent;
 932        long offset;
 933        struct blame_entry **dstq;
 934        struct blame_entry **srcq;
 935};
 936
 937/* diff chunks are from parent to target */
 938static int blame_chunk_cb(long start_a, long count_a,
 939                          long start_b, long count_b, void *data)
 940{
 941        struct blame_chunk_cb_data *d = data;
 942        if (start_a - start_b != d->offset)
 943                die("internal error in blame::blame_chunk_cb");
 944        blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
 945                    start_b + count_b, d->parent);
 946        d->offset = start_a + count_a - (start_b + count_b);
 947        return 0;
 948}
 949
 950/*
 951 * We are looking at the origin 'target' and aiming to pass blame
 952 * for the lines it is suspected to its parent.  Run diff to find
 953 * which lines came from parent and pass blame for them.
 954 */
 955static void pass_blame_to_parent(struct scoreboard *sb,
 956                                 struct origin *target,
 957                                 struct origin *parent)
 958{
 959        mmfile_t file_p, file_o;
 960        struct blame_chunk_cb_data d;
 961        struct blame_entry *newdest = NULL;
 962
 963        if (!target->suspects)
 964                return; /* nothing remains for this target */
 965
 966        d.parent = parent;
 967        d.offset = 0;
 968        d.dstq = &newdest; d.srcq = &target->suspects;
 969
 970        fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
 971        fill_origin_blob(&sb->revs->diffopt, target, &file_o);
 972        num_get_patch++;
 973
 974        if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d))
 975                die("unable to generate diff (%s -> %s)",
 976                    oid_to_hex(&parent->commit->object.oid),
 977                    oid_to_hex(&target->commit->object.oid));
 978        /* The rest are the same as the parent */
 979        blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
 980        *d.dstq = NULL;
 981        queue_blames(sb, parent, newdest);
 982
 983        return;
 984}
 985
 986/*
 987 * The lines in blame_entry after splitting blames many times can become
 988 * very small and trivial, and at some point it becomes pointless to
 989 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 990 * ordinary C program, and it is not worth to say it was copied from
 991 * totally unrelated file in the parent.
 992 *
 993 * Compute how trivial the lines in the blame_entry are.
 994 */
 995static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 996{
 997        unsigned score;
 998        const char *cp, *ep;
 999
1000        if (e->score)
1001                return e->score;
1002
1003        score = 1;
1004        cp = nth_line(sb, e->lno);
1005        ep = nth_line(sb, e->lno + e->num_lines);
1006        while (cp < ep) {
1007                unsigned ch = *((unsigned char *)cp);
1008                if (isalnum(ch))
1009                        score++;
1010                cp++;
1011        }
1012        e->score = score;
1013        return score;
1014}
1015
1016/*
1017 * best_so_far[] and this[] are both a split of an existing blame_entry
1018 * that passes blame to the parent.  Maintain best_so_far the best split
1019 * so far, by comparing this and best_so_far and copying this into
1020 * bst_so_far as needed.
1021 */
1022static void copy_split_if_better(struct scoreboard *sb,
1023                                 struct blame_entry *best_so_far,
1024                                 struct blame_entry *this)
1025{
1026        int i;
1027
1028        if (!this[1].suspect)
1029                return;
1030        if (best_so_far[1].suspect) {
1031                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
1032                        return;
1033        }
1034
1035        for (i = 0; i < 3; i++)
1036                origin_incref(this[i].suspect);
1037        decref_split(best_so_far);
1038        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
1039}
1040
1041/*
1042 * We are looking at a part of the final image represented by
1043 * ent (tlno and same are offset by ent->s_lno).
1044 * tlno is where we are looking at in the final image.
1045 * up to (but not including) same match preimage.
1046 * plno is where we are looking at in the preimage.
1047 *
1048 * <-------------- final image ---------------------->
1049 *       <------ent------>
1050 *         ^tlno ^same
1051 *    <---------preimage----->
1052 *         ^plno
1053 *
1054 * All line numbers are 0-based.
1055 */
1056static void handle_split(struct scoreboard *sb,
1057                         struct blame_entry *ent,
1058                         int tlno, int plno, int same,
1059                         struct origin *parent,
1060                         struct blame_entry *split)
1061{
1062        if (ent->num_lines <= tlno)
1063                return;
1064        if (tlno < same) {
1065                struct blame_entry this[3];
1066                tlno += ent->s_lno;
1067                same += ent->s_lno;
1068                split_overlap(this, ent, tlno, plno, same, parent);
1069                copy_split_if_better(sb, split, this);
1070                decref_split(this);
1071        }
1072}
1073
1074struct handle_split_cb_data {
1075        struct scoreboard *sb;
1076        struct blame_entry *ent;
1077        struct origin *parent;
1078        struct blame_entry *split;
1079        long plno;
1080        long tlno;
1081};
1082
1083static int handle_split_cb(long start_a, long count_a,
1084                           long start_b, long count_b, void *data)
1085{
1086        struct handle_split_cb_data *d = data;
1087        handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
1088                     d->split);
1089        d->plno = start_a + count_a;
1090        d->tlno = start_b + count_b;
1091        return 0;
1092}
1093
1094/*
1095 * Find the lines from parent that are the same as ent so that
1096 * we can pass blames to it.  file_p has the blob contents for
1097 * the parent.
1098 */
1099static void find_copy_in_blob(struct scoreboard *sb,
1100                              struct blame_entry *ent,
1101                              struct origin *parent,
1102                              struct blame_entry *split,
1103                              mmfile_t *file_p)
1104{
1105        const char *cp;
1106        mmfile_t file_o;
1107        struct handle_split_cb_data d;
1108
1109        memset(&d, 0, sizeof(d));
1110        d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
1111        /*
1112         * Prepare mmfile that contains only the lines in ent.
1113         */
1114        cp = nth_line(sb, ent->lno);
1115        file_o.ptr = (char *) cp;
1116        file_o.size = nth_line(sb, ent->lno + ent->num_lines) - cp;
1117
1118        /*
1119         * file_o is a part of final image we are annotating.
1120         * file_p partially may match that image.
1121         */
1122        memset(split, 0, sizeof(struct blame_entry [3]));
1123        if (diff_hunks(file_p, &file_o, handle_split_cb, &d))
1124                die("unable to generate diff (%s)",
1125                    oid_to_hex(&parent->commit->object.oid));
1126        /* remainder, if any, all match the preimage */
1127        handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
1128}
1129
1130/* Move all blame entries from list *source that have a score smaller
1131 * than score_min to the front of list *small.
1132 * Returns a pointer to the link pointing to the old head of the small list.
1133 */
1134
1135static struct blame_entry **filter_small(struct scoreboard *sb,
1136                                         struct blame_entry **small,
1137                                         struct blame_entry **source,
1138                                         unsigned score_min)
1139{
1140        struct blame_entry *p = *source;
1141        struct blame_entry *oldsmall = *small;
1142        while (p) {
1143                if (ent_score(sb, p) <= score_min) {
1144                        *small = p;
1145                        small = &p->next;
1146                        p = *small;
1147                } else {
1148                        *source = p;
1149                        source = &p->next;
1150                        p = *source;
1151                }
1152        }
1153        *small = oldsmall;
1154        *source = NULL;
1155        return small;
1156}
1157
1158/*
1159 * See if lines currently target is suspected for can be attributed to
1160 * parent.
1161 */
1162static void find_move_in_parent(struct scoreboard *sb,
1163                                struct blame_entry ***blamed,
1164                                struct blame_entry **toosmall,
1165                                struct origin *target,
1166                                struct origin *parent)
1167{
1168        struct blame_entry *e, split[3];
1169        struct blame_entry *unblamed = target->suspects;
1170        struct blame_entry *leftover = NULL;
1171        mmfile_t file_p;
1172
1173        if (!unblamed)
1174                return; /* nothing remains for this target */
1175
1176        fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
1177        if (!file_p.ptr)
1178                return;
1179
1180        /* At each iteration, unblamed has a NULL-terminated list of
1181         * entries that have not yet been tested for blame.  leftover
1182         * contains the reversed list of entries that have been tested
1183         * without being assignable to the parent.
1184         */
1185        do {
1186                struct blame_entry **unblamedtail = &unblamed;
1187                struct blame_entry *next;
1188                for (e = unblamed; e; e = next) {
1189                        next = e->next;
1190                        find_copy_in_blob(sb, e, parent, split, &file_p);
1191                        if (split[1].suspect &&
1192                            blame_move_score < ent_score(sb, &split[1])) {
1193                                split_blame(blamed, &unblamedtail, split, e);
1194                        } else {
1195                                e->next = leftover;
1196                                leftover = e;
1197                        }
1198                        decref_split(split);
1199                }
1200                *unblamedtail = NULL;
1201                toosmall = filter_small(sb, toosmall, &unblamed, blame_move_score);
1202        } while (unblamed);
1203        target->suspects = reverse_blame(leftover, NULL);
1204}
1205
1206struct blame_list {
1207        struct blame_entry *ent;
1208        struct blame_entry split[3];
1209};
1210
1211/*
1212 * Count the number of entries the target is suspected for,
1213 * and prepare a list of entry and the best split.
1214 */
1215static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
1216                                           int *num_ents_p)
1217{
1218        struct blame_entry *e;
1219        int num_ents, i;
1220        struct blame_list *blame_list = NULL;
1221
1222        for (e = unblamed, num_ents = 0; e; e = e->next)
1223                num_ents++;
1224        if (num_ents) {
1225                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1226                for (e = unblamed, i = 0; e; e = e->next)
1227                        blame_list[i++].ent = e;
1228        }
1229        *num_ents_p = num_ents;
1230        return blame_list;
1231}
1232
1233/*
1234 * For lines target is suspected for, see if we can find code movement
1235 * across file boundary from the parent commit.  porigin is the path
1236 * in the parent we already tried.
1237 */
1238static void find_copy_in_parent(struct scoreboard *sb,
1239                                struct blame_entry ***blamed,
1240                                struct blame_entry **toosmall,
1241                                struct origin *target,
1242                                struct commit *parent,
1243                                struct origin *porigin,
1244                                int opt)
1245{
1246        struct diff_options diff_opts;
1247        int i, j;
1248        struct blame_list *blame_list;
1249        int num_ents;
1250        struct blame_entry *unblamed = target->suspects;
1251        struct blame_entry *leftover = NULL;
1252
1253        if (!unblamed)
1254                return; /* nothing remains for this target */
1255
1256        diff_setup(&diff_opts);
1257        DIFF_OPT_SET(&diff_opts, RECURSIVE);
1258        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1259
1260        diff_setup_done(&diff_opts);
1261
1262        /* Try "find copies harder" on new path if requested;
1263         * we do not want to use diffcore_rename() actually to
1264         * match things up; find_copies_harder is set only to
1265         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1266         * and this code needs to be after diff_setup_done(), which
1267         * usually makes find-copies-harder imply copy detection.
1268         */
1269        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1270            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1271                && (!porigin || strcmp(target->path, porigin->path))))
1272                DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
1273
1274        if (is_null_oid(&target->commit->object.oid))
1275                do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
1276        else
1277                diff_tree_sha1(parent->tree->object.oid.hash,
1278                               target->commit->tree->object.oid.hash,
1279                               "", &diff_opts);
1280
1281        if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
1282                diffcore_std(&diff_opts);
1283
1284        do {
1285                struct blame_entry **unblamedtail = &unblamed;
1286                blame_list = setup_blame_list(unblamed, &num_ents);
1287
1288                for (i = 0; i < diff_queued_diff.nr; i++) {
1289                        struct diff_filepair *p = diff_queued_diff.queue[i];
1290                        struct origin *norigin;
1291                        mmfile_t file_p;
1292                        struct blame_entry this[3];
1293
1294                        if (!DIFF_FILE_VALID(p->one))
1295                                continue; /* does not exist in parent */
1296                        if (S_ISGITLINK(p->one->mode))
1297                                continue; /* ignore git links */
1298                        if (porigin && !strcmp(p->one->path, porigin->path))
1299                                /* find_move already dealt with this path */
1300                                continue;
1301
1302                        norigin = get_origin(sb, parent, p->one->path);
1303                        oidcpy(&norigin->blob_oid, &p->one->oid);
1304                        norigin->mode = p->one->mode;
1305                        fill_origin_blob(&sb->revs->diffopt, norigin, &file_p);
1306                        if (!file_p.ptr)
1307                                continue;
1308
1309                        for (j = 0; j < num_ents; j++) {
1310                                find_copy_in_blob(sb, blame_list[j].ent,
1311                                                  norigin, this, &file_p);
1312                                copy_split_if_better(sb, blame_list[j].split,
1313                                                     this);
1314                                decref_split(this);
1315                        }
1316                        origin_decref(norigin);
1317                }
1318
1319                for (j = 0; j < num_ents; j++) {
1320                        struct blame_entry *split = blame_list[j].split;
1321                        if (split[1].suspect &&
1322                            blame_copy_score < ent_score(sb, &split[1])) {
1323                                split_blame(blamed, &unblamedtail, split,
1324                                            blame_list[j].ent);
1325                        } else {
1326                                blame_list[j].ent->next = leftover;
1327                                leftover = blame_list[j].ent;
1328                        }
1329                        decref_split(split);
1330                }
1331                free(blame_list);
1332                *unblamedtail = NULL;
1333                toosmall = filter_small(sb, toosmall, &unblamed, blame_copy_score);
1334        } while (unblamed);
1335        target->suspects = reverse_blame(leftover, NULL);
1336        diff_flush(&diff_opts);
1337        clear_pathspec(&diff_opts.pathspec);
1338}
1339
1340/*
1341 * The blobs of origin and porigin exactly match, so everything
1342 * origin is suspected for can be blamed on the parent.
1343 */
1344static void pass_whole_blame(struct scoreboard *sb,
1345                             struct origin *origin, struct origin *porigin)
1346{
1347        struct blame_entry *e, *suspects;
1348
1349        if (!porigin->file.ptr && origin->file.ptr) {
1350                /* Steal its file */
1351                porigin->file = origin->file;
1352                origin->file.ptr = NULL;
1353        }
1354        suspects = origin->suspects;
1355        origin->suspects = NULL;
1356        for (e = suspects; e; e = e->next) {
1357                origin_incref(porigin);
1358                origin_decref(e->suspect);
1359                e->suspect = porigin;
1360        }
1361        queue_blames(sb, porigin, suspects);
1362}
1363
1364/*
1365 * We pass blame from the current commit to its parents.  We keep saying
1366 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1367 * exonerate ourselves.
1368 */
1369static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
1370{
1371        if (!reverse) {
1372                if (revs->first_parent_only &&
1373                    commit->parents &&
1374                    commit->parents->next) {
1375                        free_commit_list(commit->parents->next);
1376                        commit->parents->next = NULL;
1377                }
1378                return commit->parents;
1379        }
1380        return lookup_decoration(&revs->children, &commit->object);
1381}
1382
1383static int num_scapegoats(struct rev_info *revs, struct commit *commit)
1384{
1385        struct commit_list *l = first_scapegoat(revs, commit);
1386        return commit_list_count(l);
1387}
1388
1389/* Distribute collected unsorted blames to the respected sorted lists
1390 * in the various origins.
1391 */
1392static void distribute_blame(struct scoreboard *sb, struct blame_entry *blamed)
1393{
1394        blamed = blame_sort(blamed, compare_blame_suspect);
1395        while (blamed)
1396        {
1397                struct origin *porigin = blamed->suspect;
1398                struct blame_entry *suspects = NULL;
1399                do {
1400                        struct blame_entry *next = blamed->next;
1401                        blamed->next = suspects;
1402                        suspects = blamed;
1403                        blamed = next;
1404                } while (blamed && blamed->suspect == porigin);
1405                suspects = reverse_blame(suspects, NULL);
1406                queue_blames(sb, porigin, suspects);
1407        }
1408}
1409
1410#define MAXSG 16
1411
1412static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1413{
1414        struct rev_info *revs = sb->revs;
1415        int i, pass, num_sg;
1416        struct commit *commit = origin->commit;
1417        struct commit_list *sg;
1418        struct origin *sg_buf[MAXSG];
1419        struct origin *porigin, **sg_origin = sg_buf;
1420        struct blame_entry *toosmall = NULL;
1421        struct blame_entry *blames, **blametail = &blames;
1422
1423        num_sg = num_scapegoats(revs, commit);
1424        if (!num_sg)
1425                goto finish;
1426        else if (num_sg < ARRAY_SIZE(sg_buf))
1427                memset(sg_buf, 0, sizeof(sg_buf));
1428        else
1429                sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1430
1431        /*
1432         * The first pass looks for unrenamed path to optimize for
1433         * common cases, then we look for renames in the second pass.
1434         */
1435        for (pass = 0; pass < 2 - no_whole_file_rename; pass++) {
1436                struct origin *(*find)(struct scoreboard *,
1437                                       struct commit *, struct origin *);
1438                find = pass ? find_rename : find_origin;
1439
1440                for (i = 0, sg = first_scapegoat(revs, commit);
1441                     i < num_sg && sg;
1442                     sg = sg->next, i++) {
1443                        struct commit *p = sg->item;
1444                        int j, same;
1445
1446                        if (sg_origin[i])
1447                                continue;
1448                        if (parse_commit(p))
1449                                continue;
1450                        porigin = find(sb, p, origin);
1451                        if (!porigin)
1452                                continue;
1453                        if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
1454                                pass_whole_blame(sb, origin, porigin);
1455                                origin_decref(porigin);
1456                                goto finish;
1457                        }
1458                        for (j = same = 0; j < i; j++)
1459                                if (sg_origin[j] &&
1460                                    !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
1461                                        same = 1;
1462                                        break;
1463                                }
1464                        if (!same)
1465                                sg_origin[i] = porigin;
1466                        else
1467                                origin_decref(porigin);
1468                }
1469        }
1470
1471        num_commits++;
1472        for (i = 0, sg = first_scapegoat(revs, commit);
1473             i < num_sg && sg;
1474             sg = sg->next, i++) {
1475                struct origin *porigin = sg_origin[i];
1476                if (!porigin)
1477                        continue;
1478                if (!origin->previous) {
1479                        origin_incref(porigin);
1480                        origin->previous = porigin;
1481                }
1482                pass_blame_to_parent(sb, origin, porigin);
1483                if (!origin->suspects)
1484                        goto finish;
1485        }
1486
1487        /*
1488         * Optionally find moves in parents' files.
1489         */
1490        if (opt & PICKAXE_BLAME_MOVE) {
1491                filter_small(sb, &toosmall, &origin->suspects, blame_move_score);
1492                if (origin->suspects) {
1493                        for (i = 0, sg = first_scapegoat(revs, commit);
1494                             i < num_sg && sg;
1495                             sg = sg->next, i++) {
1496                                struct origin *porigin = sg_origin[i];
1497                                if (!porigin)
1498                                        continue;
1499                                find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
1500                                if (!origin->suspects)
1501                                        break;
1502                        }
1503                }
1504        }
1505
1506        /*
1507         * Optionally find copies from parents' files.
1508         */
1509        if (opt & PICKAXE_BLAME_COPY) {
1510                if (blame_copy_score > blame_move_score)
1511                        filter_small(sb, &toosmall, &origin->suspects, blame_copy_score);
1512                else if (blame_copy_score < blame_move_score) {
1513                        origin->suspects = blame_merge(origin->suspects, toosmall);
1514                        toosmall = NULL;
1515                        filter_small(sb, &toosmall, &origin->suspects, blame_copy_score);
1516                }
1517                if (!origin->suspects)
1518                        goto finish;
1519
1520                for (i = 0, sg = first_scapegoat(revs, commit);
1521                     i < num_sg && sg;
1522                     sg = sg->next, i++) {
1523                        struct origin *porigin = sg_origin[i];
1524                        find_copy_in_parent(sb, &blametail, &toosmall,
1525                                            origin, sg->item, porigin, opt);
1526                        if (!origin->suspects)
1527                                goto finish;
1528                }
1529        }
1530
1531finish:
1532        *blametail = NULL;
1533        distribute_blame(sb, blames);
1534        /*
1535         * prepend toosmall to origin->suspects
1536         *
1537         * There is no point in sorting: this ends up on a big
1538         * unsorted list in the caller anyway.
1539         */
1540        if (toosmall) {
1541                struct blame_entry **tail = &toosmall;
1542                while (*tail)
1543                        tail = &(*tail)->next;
1544                *tail = origin->suspects;
1545                origin->suspects = toosmall;
1546        }
1547        for (i = 0; i < num_sg; i++) {
1548                if (sg_origin[i]) {
1549                        drop_origin_blob(sg_origin[i]);
1550                        origin_decref(sg_origin[i]);
1551                }
1552        }
1553        drop_origin_blob(origin);
1554        if (sg_buf != sg_origin)
1555                free(sg_origin);
1556}
1557
1558/*
1559 * Information on commits, used for output.
1560 */
1561struct commit_info {
1562        struct strbuf author;
1563        struct strbuf author_mail;
1564        unsigned long author_time;
1565        struct strbuf author_tz;
1566
1567        /* filled only when asked for details */
1568        struct strbuf committer;
1569        struct strbuf committer_mail;
1570        unsigned long committer_time;
1571        struct strbuf committer_tz;
1572
1573        struct strbuf summary;
1574};
1575
1576/*
1577 * Parse author/committer line in the commit object buffer
1578 */
1579static void get_ac_line(const char *inbuf, const char *what,
1580        struct strbuf *name, struct strbuf *mail,
1581        unsigned long *time, struct strbuf *tz)
1582{
1583        struct ident_split ident;
1584        size_t len, maillen, namelen;
1585        char *tmp, *endp;
1586        const char *namebuf, *mailbuf;
1587
1588        tmp = strstr(inbuf, what);
1589        if (!tmp)
1590                goto error_out;
1591        tmp += strlen(what);
1592        endp = strchr(tmp, '\n');
1593        if (!endp)
1594                len = strlen(tmp);
1595        else
1596                len = endp - tmp;
1597
1598        if (split_ident_line(&ident, tmp, len)) {
1599        error_out:
1600                /* Ugh */
1601                tmp = "(unknown)";
1602                strbuf_addstr(name, tmp);
1603                strbuf_addstr(mail, tmp);
1604                strbuf_addstr(tz, tmp);
1605                *time = 0;
1606                return;
1607        }
1608
1609        namelen = ident.name_end - ident.name_begin;
1610        namebuf = ident.name_begin;
1611
1612        maillen = ident.mail_end - ident.mail_begin;
1613        mailbuf = ident.mail_begin;
1614
1615        if (ident.date_begin && ident.date_end)
1616                *time = strtoul(ident.date_begin, NULL, 10);
1617        else
1618                *time = 0;
1619
1620        if (ident.tz_begin && ident.tz_end)
1621                strbuf_add(tz, ident.tz_begin, ident.tz_end - ident.tz_begin);
1622        else
1623                strbuf_addstr(tz, "(unknown)");
1624
1625        /*
1626         * Now, convert both name and e-mail using mailmap
1627         */
1628        map_user(&mailmap, &mailbuf, &maillen,
1629                 &namebuf, &namelen);
1630
1631        strbuf_addf(mail, "<%.*s>", (int)maillen, mailbuf);
1632        strbuf_add(name, namebuf, namelen);
1633}
1634
1635static void commit_info_init(struct commit_info *ci)
1636{
1637
1638        strbuf_init(&ci->author, 0);
1639        strbuf_init(&ci->author_mail, 0);
1640        strbuf_init(&ci->author_tz, 0);
1641        strbuf_init(&ci->committer, 0);
1642        strbuf_init(&ci->committer_mail, 0);
1643        strbuf_init(&ci->committer_tz, 0);
1644        strbuf_init(&ci->summary, 0);
1645}
1646
1647static void commit_info_destroy(struct commit_info *ci)
1648{
1649
1650        strbuf_release(&ci->author);
1651        strbuf_release(&ci->author_mail);
1652        strbuf_release(&ci->author_tz);
1653        strbuf_release(&ci->committer);
1654        strbuf_release(&ci->committer_mail);
1655        strbuf_release(&ci->committer_tz);
1656        strbuf_release(&ci->summary);
1657}
1658
1659static void get_commit_info(struct commit *commit,
1660                            struct commit_info *ret,
1661                            int detailed)
1662{
1663        int len;
1664        const char *subject, *encoding;
1665        const char *message;
1666
1667        commit_info_init(ret);
1668
1669        encoding = get_log_output_encoding();
1670        message = logmsg_reencode(commit, NULL, encoding);
1671        get_ac_line(message, "\nauthor ",
1672                    &ret->author, &ret->author_mail,
1673                    &ret->author_time, &ret->author_tz);
1674
1675        if (!detailed) {
1676                unuse_commit_buffer(commit, message);
1677                return;
1678        }
1679
1680        get_ac_line(message, "\ncommitter ",
1681                    &ret->committer, &ret->committer_mail,
1682                    &ret->committer_time, &ret->committer_tz);
1683
1684        len = find_commit_subject(message, &subject);
1685        if (len)
1686                strbuf_add(&ret->summary, subject, len);
1687        else
1688                strbuf_addf(&ret->summary, "(%s)", oid_to_hex(&commit->object.oid));
1689
1690        unuse_commit_buffer(commit, message);
1691}
1692
1693/*
1694 * Write out any suspect information which depends on the path. This must be
1695 * handled separately from emit_one_suspect_detail(), because a given commit
1696 * may have changes in multiple paths. So this needs to appear each time
1697 * we mention a new group.
1698 *
1699 * To allow LF and other nonportable characters in pathnames,
1700 * they are c-style quoted as needed.
1701 */
1702static void write_filename_info(struct origin *suspect)
1703{
1704        if (suspect->previous) {
1705                struct origin *prev = suspect->previous;
1706                printf("previous %s ", oid_to_hex(&prev->commit->object.oid));
1707                write_name_quoted(prev->path, stdout, '\n');
1708        }
1709        printf("filename ");
1710        write_name_quoted(suspect->path, stdout, '\n');
1711}
1712
1713/*
1714 * Porcelain/Incremental format wants to show a lot of details per
1715 * commit.  Instead of repeating this every line, emit it only once,
1716 * the first time each commit appears in the output (unless the
1717 * user has specifically asked for us to repeat).
1718 */
1719static int emit_one_suspect_detail(struct origin *suspect, int repeat)
1720{
1721        struct commit_info ci;
1722
1723        if (!repeat && (suspect->commit->object.flags & METAINFO_SHOWN))
1724                return 0;
1725
1726        suspect->commit->object.flags |= METAINFO_SHOWN;
1727        get_commit_info(suspect->commit, &ci, 1);
1728        printf("author %s\n", ci.author.buf);
1729        printf("author-mail %s\n", ci.author_mail.buf);
1730        printf("author-time %lu\n", ci.author_time);
1731        printf("author-tz %s\n", ci.author_tz.buf);
1732        printf("committer %s\n", ci.committer.buf);
1733        printf("committer-mail %s\n", ci.committer_mail.buf);
1734        printf("committer-time %lu\n", ci.committer_time);
1735        printf("committer-tz %s\n", ci.committer_tz.buf);
1736        printf("summary %s\n", ci.summary.buf);
1737        if (suspect->commit->object.flags & UNINTERESTING)
1738                printf("boundary\n");
1739
1740        commit_info_destroy(&ci);
1741
1742        return 1;
1743}
1744
1745/*
1746 * The blame_entry is found to be guilty for the range.
1747 * Show it in incremental output.
1748 */
1749static void found_guilty_entry(struct blame_entry *ent,
1750                           struct progress_info *pi)
1751{
1752        if (incremental) {
1753                struct origin *suspect = ent->suspect;
1754
1755                printf("%s %d %d %d\n",
1756                       oid_to_hex(&suspect->commit->object.oid),
1757                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1758                emit_one_suspect_detail(suspect, 0);
1759                write_filename_info(suspect);
1760                maybe_flush_or_die(stdout, "stdout");
1761        }
1762        pi->blamed_lines += ent->num_lines;
1763        display_progress(pi->progress, pi->blamed_lines);
1764}
1765
1766/*
1767 * The main loop -- while we have blobs with lines whose true origin
1768 * is still unknown, pick one blob, and allow its lines to pass blames
1769 * to its parents. */
1770static void assign_blame(struct scoreboard *sb, int opt)
1771{
1772        struct rev_info *revs = sb->revs;
1773        struct commit *commit = prio_queue_get(&sb->commits);
1774        struct progress_info pi = { NULL, 0 };
1775
1776        if (show_progress)
1777                pi.progress = start_progress_delay(_("Blaming lines"),
1778                                                   sb->num_lines, 50, 1);
1779
1780        while (commit) {
1781                struct blame_entry *ent;
1782                struct origin *suspect = commit->util;
1783
1784                /* find one suspect to break down */
1785                while (suspect && !suspect->suspects)
1786                        suspect = suspect->next;
1787
1788                if (!suspect) {
1789                        commit = prio_queue_get(&sb->commits);
1790                        continue;
1791                }
1792
1793                assert(commit == suspect->commit);
1794
1795                /*
1796                 * We will use this suspect later in the loop,
1797                 * so hold onto it in the meantime.
1798                 */
1799                origin_incref(suspect);
1800                parse_commit(commit);
1801                if (reverse ||
1802                    (!(commit->object.flags & UNINTERESTING) &&
1803                     !(revs->max_age != -1 && commit->date < revs->max_age)))
1804                        pass_blame(sb, suspect, opt);
1805                else {
1806                        commit->object.flags |= UNINTERESTING;
1807                        if (commit->object.parsed)
1808                                mark_parents_uninteresting(commit);
1809                }
1810                /* treat root commit as boundary */
1811                if (!commit->parents && !show_root)
1812                        commit->object.flags |= UNINTERESTING;
1813
1814                /* Take responsibility for the remaining entries */
1815                ent = suspect->suspects;
1816                if (ent) {
1817                        suspect->guilty = 1;
1818                        for (;;) {
1819                                struct blame_entry *next = ent->next;
1820                                found_guilty_entry(ent, &pi);
1821                                if (next) {
1822                                        ent = next;
1823                                        continue;
1824                                }
1825                                ent->next = sb->ent;
1826                                sb->ent = suspect->suspects;
1827                                suspect->suspects = NULL;
1828                                break;
1829                        }
1830                }
1831                origin_decref(suspect);
1832
1833                if (DEBUG) /* sanity */
1834                        sanity_check_refcnt(sb);
1835        }
1836
1837        stop_progress(&pi.progress);
1838}
1839
1840static const char *format_time(unsigned long time, const char *tz_str,
1841                               int show_raw_time)
1842{
1843        static struct strbuf time_buf = STRBUF_INIT;
1844
1845        strbuf_reset(&time_buf);
1846        if (show_raw_time) {
1847                strbuf_addf(&time_buf, "%lu %s", time, tz_str);
1848        }
1849        else {
1850                const char *time_str;
1851                size_t time_width;
1852                int tz;
1853                tz = atoi(tz_str);
1854                time_str = show_date(time, tz, &blame_date_mode);
1855                strbuf_addstr(&time_buf, time_str);
1856                /*
1857                 * Add space paddings to time_buf to display a fixed width
1858                 * string, and use time_width for display width calibration.
1859                 */
1860                for (time_width = utf8_strwidth(time_str);
1861                     time_width < blame_date_width;
1862                     time_width++)
1863                        strbuf_addch(&time_buf, ' ');
1864        }
1865        return time_buf.buf;
1866}
1867
1868#define OUTPUT_ANNOTATE_COMPAT  001
1869#define OUTPUT_LONG_OBJECT_NAME 002
1870#define OUTPUT_RAW_TIMESTAMP    004
1871#define OUTPUT_PORCELAIN        010
1872#define OUTPUT_SHOW_NAME        020
1873#define OUTPUT_SHOW_NUMBER      040
1874#define OUTPUT_SHOW_SCORE      0100
1875#define OUTPUT_NO_AUTHOR       0200
1876#define OUTPUT_SHOW_EMAIL       0400
1877#define OUTPUT_LINE_PORCELAIN 01000
1878
1879static void emit_porcelain_details(struct origin *suspect, int repeat)
1880{
1881        if (emit_one_suspect_detail(suspect, repeat) ||
1882            (suspect->commit->object.flags & MORE_THAN_ONE_PATH))
1883                write_filename_info(suspect);
1884}
1885
1886static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent,
1887                           int opt)
1888{
1889        int repeat = opt & OUTPUT_LINE_PORCELAIN;
1890        int cnt;
1891        const char *cp;
1892        struct origin *suspect = ent->suspect;
1893        char hex[GIT_MAX_HEXSZ + 1];
1894
1895        oid_to_hex_r(hex, &suspect->commit->object.oid);
1896        printf("%s %d %d %d\n",
1897               hex,
1898               ent->s_lno + 1,
1899               ent->lno + 1,
1900               ent->num_lines);
1901        emit_porcelain_details(suspect, repeat);
1902
1903        cp = nth_line(sb, ent->lno);
1904        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1905                char ch;
1906                if (cnt) {
1907                        printf("%s %d %d\n", hex,
1908                               ent->s_lno + 1 + cnt,
1909                               ent->lno + 1 + cnt);
1910                        if (repeat)
1911                                emit_porcelain_details(suspect, 1);
1912                }
1913                putchar('\t');
1914                do {
1915                        ch = *cp++;
1916                        putchar(ch);
1917                } while (ch != '\n' &&
1918                         cp < sb->final_buf + sb->final_buf_size);
1919        }
1920
1921        if (sb->final_buf_size && cp[-1] != '\n')
1922                putchar('\n');
1923}
1924
1925static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1926{
1927        int cnt;
1928        const char *cp;
1929        struct origin *suspect = ent->suspect;
1930        struct commit_info ci;
1931        char hex[GIT_MAX_HEXSZ + 1];
1932        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1933
1934        get_commit_info(suspect->commit, &ci, 1);
1935        oid_to_hex_r(hex, &suspect->commit->object.oid);
1936
1937        cp = nth_line(sb, ent->lno);
1938        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1939                char ch;
1940                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? GIT_SHA1_HEXSZ : abbrev;
1941
1942                if (suspect->commit->object.flags & UNINTERESTING) {
1943                        if (blank_boundary)
1944                                memset(hex, ' ', length);
1945                        else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
1946                                length--;
1947                                putchar('^');
1948                        }
1949                }
1950
1951                printf("%.*s", length, hex);
1952                if (opt & OUTPUT_ANNOTATE_COMPAT) {
1953                        const char *name;
1954                        if (opt & OUTPUT_SHOW_EMAIL)
1955                                name = ci.author_mail.buf;
1956                        else
1957                                name = ci.author.buf;
1958                        printf("\t(%10s\t%10s\t%d)", name,
1959                               format_time(ci.author_time, ci.author_tz.buf,
1960                                           show_raw_time),
1961                               ent->lno + 1 + cnt);
1962                } else {
1963                        if (opt & OUTPUT_SHOW_SCORE)
1964                                printf(" %*d %02d",
1965                                       max_score_digits, ent->score,
1966                                       ent->suspect->refcnt);
1967                        if (opt & OUTPUT_SHOW_NAME)
1968                                printf(" %-*.*s", longest_file, longest_file,
1969                                       suspect->path);
1970                        if (opt & OUTPUT_SHOW_NUMBER)
1971                                printf(" %*d", max_orig_digits,
1972                                       ent->s_lno + 1 + cnt);
1973
1974                        if (!(opt & OUTPUT_NO_AUTHOR)) {
1975                                const char *name;
1976                                int pad;
1977                                if (opt & OUTPUT_SHOW_EMAIL)
1978                                        name = ci.author_mail.buf;
1979                                else
1980                                        name = ci.author.buf;
1981                                pad = longest_author - utf8_strwidth(name);
1982                                printf(" (%s%*s %10s",
1983                                       name, pad, "",
1984                                       format_time(ci.author_time,
1985                                                   ci.author_tz.buf,
1986                                                   show_raw_time));
1987                        }
1988                        printf(" %*d) ",
1989                               max_digits, ent->lno + 1 + cnt);
1990                }
1991                do {
1992                        ch = *cp++;
1993                        putchar(ch);
1994                } while (ch != '\n' &&
1995                         cp < sb->final_buf + sb->final_buf_size);
1996        }
1997
1998        if (sb->final_buf_size && cp[-1] != '\n')
1999                putchar('\n');
2000
2001        commit_info_destroy(&ci);
2002}
2003
2004static void output(struct scoreboard *sb, int option)
2005{
2006        struct blame_entry *ent;
2007
2008        if (option & OUTPUT_PORCELAIN) {
2009                for (ent = sb->ent; ent; ent = ent->next) {
2010                        int count = 0;
2011                        struct origin *suspect;
2012                        struct commit *commit = ent->suspect->commit;
2013                        if (commit->object.flags & MORE_THAN_ONE_PATH)
2014                                continue;
2015                        for (suspect = commit->util; suspect; suspect = suspect->next) {
2016                                if (suspect->guilty && count++) {
2017                                        commit->object.flags |= MORE_THAN_ONE_PATH;
2018                                        break;
2019                                }
2020                        }
2021                }
2022        }
2023
2024        for (ent = sb->ent; ent; ent = ent->next) {
2025                if (option & OUTPUT_PORCELAIN)
2026                        emit_porcelain(sb, ent, option);
2027                else {
2028                        emit_other(sb, ent, option);
2029                }
2030        }
2031}
2032
2033static const char *get_next_line(const char *start, const char *end)
2034{
2035        const char *nl = memchr(start, '\n', end - start);
2036        return nl ? nl + 1 : end;
2037}
2038
2039/*
2040 * To allow quick access to the contents of nth line in the
2041 * final image, prepare an index in the scoreboard.
2042 */
2043static int prepare_lines(struct scoreboard *sb)
2044{
2045        const char *buf = sb->final_buf;
2046        unsigned long len = sb->final_buf_size;
2047        const char *end = buf + len;
2048        const char *p;
2049        int *lineno;
2050        int num = 0;
2051
2052        for (p = buf; p < end; p = get_next_line(p, end))
2053                num++;
2054
2055        ALLOC_ARRAY(sb->lineno, num + 1);
2056        lineno = sb->lineno;
2057
2058        for (p = buf; p < end; p = get_next_line(p, end))
2059                *lineno++ = p - buf;
2060
2061        *lineno = len;
2062
2063        sb->num_lines = num;
2064        return sb->num_lines;
2065}
2066
2067/*
2068 * Add phony grafts for use with -S; this is primarily to
2069 * support git's cvsserver that wants to give a linear history
2070 * to its clients.
2071 */
2072static int read_ancestry(const char *graft_file)
2073{
2074        FILE *fp = fopen(graft_file, "r");
2075        struct strbuf buf = STRBUF_INIT;
2076        if (!fp)
2077                return -1;
2078        while (!strbuf_getwholeline(&buf, fp, '\n')) {
2079                /* The format is just "Commit Parent1 Parent2 ...\n" */
2080                struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
2081                if (graft)
2082                        register_commit_graft(graft, 0);
2083        }
2084        fclose(fp);
2085        strbuf_release(&buf);
2086        return 0;
2087}
2088
2089static int update_auto_abbrev(int auto_abbrev, struct origin *suspect)
2090{
2091        const char *uniq = find_unique_abbrev(suspect->commit->object.oid.hash,
2092                                              auto_abbrev);
2093        int len = strlen(uniq);
2094        if (auto_abbrev < len)
2095                return len;
2096        return auto_abbrev;
2097}
2098
2099/*
2100 * How many columns do we need to show line numbers, authors,
2101 * and filenames?
2102 */
2103static void find_alignment(struct scoreboard *sb, int *option)
2104{
2105        int longest_src_lines = 0;
2106        int longest_dst_lines = 0;
2107        unsigned largest_score = 0;
2108        struct blame_entry *e;
2109        int compute_auto_abbrev = (abbrev < 0);
2110        int auto_abbrev = DEFAULT_ABBREV;
2111
2112        for (e = sb->ent; e; e = e->next) {
2113                struct origin *suspect = e->suspect;
2114                int num;
2115
2116                if (compute_auto_abbrev)
2117                        auto_abbrev = update_auto_abbrev(auto_abbrev, suspect);
2118                if (strcmp(suspect->path, sb->path))
2119                        *option |= OUTPUT_SHOW_NAME;
2120                num = strlen(suspect->path);
2121                if (longest_file < num)
2122                        longest_file = num;
2123                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
2124                        struct commit_info ci;
2125                        suspect->commit->object.flags |= METAINFO_SHOWN;
2126                        get_commit_info(suspect->commit, &ci, 1);
2127                        if (*option & OUTPUT_SHOW_EMAIL)
2128                                num = utf8_strwidth(ci.author_mail.buf);
2129                        else
2130                                num = utf8_strwidth(ci.author.buf);
2131                        if (longest_author < num)
2132                                longest_author = num;
2133                        commit_info_destroy(&ci);
2134                }
2135                num = e->s_lno + e->num_lines;
2136                if (longest_src_lines < num)
2137                        longest_src_lines = num;
2138                num = e->lno + e->num_lines;
2139                if (longest_dst_lines < num)
2140                        longest_dst_lines = num;
2141                if (largest_score < ent_score(sb, e))
2142                        largest_score = ent_score(sb, e);
2143        }
2144        max_orig_digits = decimal_width(longest_src_lines);
2145        max_digits = decimal_width(longest_dst_lines);
2146        max_score_digits = decimal_width(largest_score);
2147
2148        if (compute_auto_abbrev)
2149                /* one more abbrev length is needed for the boundary commit */
2150                abbrev = auto_abbrev + 1;
2151}
2152
2153/*
2154 * For debugging -- origin is refcounted, and this asserts that
2155 * we do not underflow.
2156 */
2157static void sanity_check_refcnt(struct scoreboard *sb)
2158{
2159        int baa = 0;
2160        struct blame_entry *ent;
2161
2162        for (ent = sb->ent; ent; ent = ent->next) {
2163                /* Nobody should have zero or negative refcnt */
2164                if (ent->suspect->refcnt <= 0) {
2165                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
2166                                ent->suspect->path,
2167                                oid_to_hex(&ent->suspect->commit->object.oid),
2168                                ent->suspect->refcnt);
2169                        baa = 1;
2170                }
2171        }
2172        if (baa) {
2173                int opt = 0160;
2174                find_alignment(sb, &opt);
2175                output(sb, opt);
2176                die("Baa %d!", baa);
2177        }
2178}
2179
2180static unsigned parse_score(const char *arg)
2181{
2182        char *end;
2183        unsigned long score = strtoul(arg, &end, 10);
2184        if (*end)
2185                return 0;
2186        return score;
2187}
2188
2189static const char *add_prefix(const char *prefix, const char *path)
2190{
2191        return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
2192}
2193
2194static int git_blame_config(const char *var, const char *value, void *cb)
2195{
2196        if (!strcmp(var, "blame.showroot")) {
2197                show_root = git_config_bool(var, value);
2198                return 0;
2199        }
2200        if (!strcmp(var, "blame.blankboundary")) {
2201                blank_boundary = git_config_bool(var, value);
2202                return 0;
2203        }
2204        if (!strcmp(var, "blame.showemail")) {
2205                int *output_option = cb;
2206                if (git_config_bool(var, value))
2207                        *output_option |= OUTPUT_SHOW_EMAIL;
2208                else
2209                        *output_option &= ~OUTPUT_SHOW_EMAIL;
2210                return 0;
2211        }
2212        if (!strcmp(var, "blame.date")) {
2213                if (!value)
2214                        return config_error_nonbool(var);
2215                parse_date_format(value, &blame_date_mode);
2216                return 0;
2217        }
2218
2219        if (git_diff_heuristic_config(var, value, cb) < 0)
2220                return -1;
2221        if (userdiff_config(var, value) < 0)
2222                return -1;
2223
2224        return git_default_config(var, value, cb);
2225}
2226
2227static void verify_working_tree_path(struct commit *work_tree, const char *path)
2228{
2229        struct commit_list *parents;
2230        int pos;
2231
2232        for (parents = work_tree->parents; parents; parents = parents->next) {
2233                const struct object_id *commit_oid = &parents->item->object.oid;
2234                struct object_id blob_oid;
2235                unsigned mode;
2236
2237                if (!get_tree_entry(commit_oid->hash, path, blob_oid.hash, &mode) &&
2238                    sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
2239                        return;
2240        }
2241
2242        pos = cache_name_pos(path, strlen(path));
2243        if (pos >= 0)
2244                ; /* path is in the index */
2245        else if (-1 - pos < active_nr &&
2246                 !strcmp(active_cache[-1 - pos]->name, path))
2247                ; /* path is in the index, unmerged */
2248        else
2249                die("no such path '%s' in HEAD", path);
2250}
2251
2252static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
2253{
2254        struct commit *parent;
2255
2256        parent = lookup_commit_reference(oid->hash);
2257        if (!parent)
2258                die("no such commit %s", oid_to_hex(oid));
2259        return &commit_list_insert(parent, tail)->next;
2260}
2261
2262static void append_merge_parents(struct commit_list **tail)
2263{
2264        int merge_head;
2265        struct strbuf line = STRBUF_INIT;
2266
2267        merge_head = open(git_path_merge_head(), O_RDONLY);
2268        if (merge_head < 0) {
2269                if (errno == ENOENT)
2270                        return;
2271                die("cannot open '%s' for reading", git_path_merge_head());
2272        }
2273
2274        while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
2275                struct object_id oid;
2276                if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
2277                        die("unknown line in '%s': %s", git_path_merge_head(), line.buf);
2278                tail = append_parent(tail, &oid);
2279        }
2280        close(merge_head);
2281        strbuf_release(&line);
2282}
2283
2284/*
2285 * This isn't as simple as passing sb->buf and sb->len, because we
2286 * want to transfer ownership of the buffer to the commit (so we
2287 * must use detach).
2288 */
2289static void set_commit_buffer_from_strbuf(struct commit *c, struct strbuf *sb)
2290{
2291        size_t len;
2292        void *buf = strbuf_detach(sb, &len);
2293        set_commit_buffer(c, buf, len);
2294}
2295
2296/*
2297 * Prepare a dummy commit that represents the work tree (or staged) item.
2298 * Note that annotating work tree item never works in the reverse.
2299 */
2300static struct commit *fake_working_tree_commit(struct diff_options *opt,
2301                                               const char *path,
2302                                               const char *contents_from)
2303{
2304        struct commit *commit;
2305        struct origin *origin;
2306        struct commit_list **parent_tail, *parent;
2307        struct object_id head_oid;
2308        struct strbuf buf = STRBUF_INIT;
2309        const char *ident;
2310        time_t now;
2311        int size, len;
2312        struct cache_entry *ce;
2313        unsigned mode;
2314        struct strbuf msg = STRBUF_INIT;
2315
2316        read_cache();
2317        time(&now);
2318        commit = alloc_commit_node();
2319        commit->object.parsed = 1;
2320        commit->date = now;
2321        parent_tail = &commit->parents;
2322
2323        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
2324                die("no such ref: HEAD");
2325
2326        parent_tail = append_parent(parent_tail, &head_oid);
2327        append_merge_parents(parent_tail);
2328        verify_working_tree_path(commit, path);
2329
2330        origin = make_origin(commit, path);
2331
2332        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2333        strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
2334        for (parent = commit->parents; parent; parent = parent->next)
2335                strbuf_addf(&msg, "parent %s\n",
2336                            oid_to_hex(&parent->item->object.oid));
2337        strbuf_addf(&msg,
2338                    "author %s\n"
2339                    "committer %s\n\n"
2340                    "Version of %s from %s\n",
2341                    ident, ident, path,
2342                    (!contents_from ? path :
2343                     (!strcmp(contents_from, "-") ? "standard input" : contents_from)));
2344        set_commit_buffer_from_strbuf(commit, &msg);
2345
2346        if (!contents_from || strcmp("-", contents_from)) {
2347                struct stat st;
2348                const char *read_from;
2349                char *buf_ptr;
2350                unsigned long buf_len;
2351
2352                if (contents_from) {
2353                        if (stat(contents_from, &st) < 0)
2354                                die_errno("Cannot stat '%s'", contents_from);
2355                        read_from = contents_from;
2356                }
2357                else {
2358                        if (lstat(path, &st) < 0)
2359                                die_errno("Cannot lstat '%s'", path);
2360                        read_from = path;
2361                }
2362                mode = canon_mode(st.st_mode);
2363
2364                switch (st.st_mode & S_IFMT) {
2365                case S_IFREG:
2366                        if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
2367                            textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
2368                                strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
2369                        else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
2370                                die_errno("cannot open or read '%s'", read_from);
2371                        break;
2372                case S_IFLNK:
2373                        if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
2374                                die_errno("cannot readlink '%s'", read_from);
2375                        break;
2376                default:
2377                        die("unsupported file type %s", read_from);
2378                }
2379        }
2380        else {
2381                /* Reading from stdin */
2382                mode = 0;
2383                if (strbuf_read(&buf, 0, 0) < 0)
2384                        die_errno("failed to read from stdin");
2385        }
2386        convert_to_git(path, buf.buf, buf.len, &buf, 0);
2387        origin->file.ptr = buf.buf;
2388        origin->file.size = buf.len;
2389        pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_oid.hash);
2390
2391        /*
2392         * Read the current index, replace the path entry with
2393         * origin->blob_sha1 without mucking with its mode or type
2394         * bits; we are not going to write this index out -- we just
2395         * want to run "diff-index --cached".
2396         */
2397        discard_cache();
2398        read_cache();
2399
2400        len = strlen(path);
2401        if (!mode) {
2402                int pos = cache_name_pos(path, len);
2403                if (0 <= pos)
2404                        mode = active_cache[pos]->ce_mode;
2405                else
2406                        /* Let's not bother reading from HEAD tree */
2407                        mode = S_IFREG | 0644;
2408        }
2409        size = cache_entry_size(len);
2410        ce = xcalloc(1, size);
2411        oidcpy(&ce->oid, &origin->blob_oid);
2412        memcpy(ce->name, path, len);
2413        ce->ce_flags = create_ce_flags(0);
2414        ce->ce_namelen = len;
2415        ce->ce_mode = create_ce_mode(mode);
2416        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2417
2418        cache_tree_invalidate_path(&the_index, path);
2419
2420        return commit;
2421}
2422
2423static struct commit *find_single_final(struct rev_info *revs,
2424                                        const char **name_p)
2425{
2426        int i;
2427        struct commit *found = NULL;
2428        const char *name = NULL;
2429
2430        for (i = 0; i < revs->pending.nr; i++) {
2431                struct object *obj = revs->pending.objects[i].item;
2432                if (obj->flags & UNINTERESTING)
2433                        continue;
2434                obj = deref_tag(obj, NULL, 0);
2435                if (obj->type != OBJ_COMMIT)
2436                        die("Non commit %s?", revs->pending.objects[i].name);
2437                if (found)
2438                        die("More than one commit to dig from %s and %s?",
2439                            revs->pending.objects[i].name, name);
2440                found = (struct commit *)obj;
2441                name = revs->pending.objects[i].name;
2442        }
2443        if (name_p)
2444                *name_p = name;
2445        return found;
2446}
2447
2448static char *prepare_final(struct scoreboard *sb)
2449{
2450        const char *name;
2451        sb->final = find_single_final(sb->revs, &name);
2452        return xstrdup_or_null(name);
2453}
2454
2455static const char *dwim_reverse_initial(struct scoreboard *sb)
2456{
2457        /*
2458         * DWIM "git blame --reverse ONE -- PATH" as
2459         * "git blame --reverse ONE..HEAD -- PATH" but only do so
2460         * when it makes sense.
2461         */
2462        struct object *obj;
2463        struct commit *head_commit;
2464        unsigned char head_sha1[20];
2465
2466        if (sb->revs->pending.nr != 1)
2467                return NULL;
2468
2469        /* Is that sole rev a committish? */
2470        obj = sb->revs->pending.objects[0].item;
2471        obj = deref_tag(obj, NULL, 0);
2472        if (obj->type != OBJ_COMMIT)
2473                return NULL;
2474
2475        /* Do we have HEAD? */
2476        if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
2477                return NULL;
2478        head_commit = lookup_commit_reference_gently(head_sha1, 1);
2479        if (!head_commit)
2480                return NULL;
2481
2482        /* Turn "ONE" into "ONE..HEAD" then */
2483        obj->flags |= UNINTERESTING;
2484        add_pending_object(sb->revs, &head_commit->object, "HEAD");
2485
2486        sb->final = (struct commit *)obj;
2487        return sb->revs->pending.objects[0].name;
2488}
2489
2490static char *prepare_initial(struct scoreboard *sb)
2491{
2492        int i;
2493        const char *final_commit_name = NULL;
2494        struct rev_info *revs = sb->revs;
2495
2496        /*
2497         * There must be one and only one negative commit, and it must be
2498         * the boundary.
2499         */
2500        for (i = 0; i < revs->pending.nr; i++) {
2501                struct object *obj = revs->pending.objects[i].item;
2502                if (!(obj->flags & UNINTERESTING))
2503                        continue;
2504                obj = deref_tag(obj, NULL, 0);
2505                if (obj->type != OBJ_COMMIT)
2506                        die("Non commit %s?", revs->pending.objects[i].name);
2507                if (sb->final)
2508                        die("More than one commit to dig up from, %s and %s?",
2509                            revs->pending.objects[i].name,
2510                            final_commit_name);
2511                sb->final = (struct commit *) obj;
2512                final_commit_name = revs->pending.objects[i].name;
2513        }
2514
2515        if (!final_commit_name)
2516                final_commit_name = dwim_reverse_initial(sb);
2517        if (!final_commit_name)
2518                die("No commit to dig up from?");
2519        return xstrdup(final_commit_name);
2520}
2521
2522static int blame_copy_callback(const struct option *option, const char *arg, int unset)
2523{
2524        int *opt = option->value;
2525
2526        /*
2527         * -C enables copy from removed files;
2528         * -C -C enables copy from existing files, but only
2529         *       when blaming a new file;
2530         * -C -C -C enables copy from existing files for
2531         *          everybody
2532         */
2533        if (*opt & PICKAXE_BLAME_COPY_HARDER)
2534                *opt |= PICKAXE_BLAME_COPY_HARDEST;
2535        if (*opt & PICKAXE_BLAME_COPY)
2536                *opt |= PICKAXE_BLAME_COPY_HARDER;
2537        *opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2538
2539        if (arg)
2540                blame_copy_score = parse_score(arg);
2541        return 0;
2542}
2543
2544static int blame_move_callback(const struct option *option, const char *arg, int unset)
2545{
2546        int *opt = option->value;
2547
2548        *opt |= PICKAXE_BLAME_MOVE;
2549
2550        if (arg)
2551                blame_move_score = parse_score(arg);
2552        return 0;
2553}
2554
2555int cmd_blame(int argc, const char **argv, const char *prefix)
2556{
2557        struct rev_info revs;
2558        const char *path;
2559        struct scoreboard sb;
2560        struct origin *o;
2561        struct blame_entry *ent = NULL;
2562        long dashdash_pos, lno;
2563        char *final_commit_name = NULL;
2564        enum object_type type;
2565        struct commit *final_commit = NULL;
2566
2567        struct string_list range_list = STRING_LIST_INIT_NODUP;
2568        int output_option = 0, opt = 0;
2569        int show_stats = 0;
2570        const char *revs_file = NULL;
2571        const char *contents_from = NULL;
2572        const struct option options[] = {
2573                OPT_BOOL(0, "incremental", &incremental, N_("Show blame entries as we find them, incrementally")),
2574                OPT_BOOL('b', NULL, &blank_boundary, N_("Show blank SHA-1 for boundary commits (Default: off)")),
2575                OPT_BOOL(0, "root", &show_root, N_("Do not treat root commits as boundaries (Default: off)")),
2576                OPT_BOOL(0, "show-stats", &show_stats, N_("Show work cost statistics")),
2577                OPT_BOOL(0, "progress", &show_progress, N_("Force progress reporting")),
2578                OPT_BIT(0, "score-debug", &output_option, N_("Show output score for blame entries"), OUTPUT_SHOW_SCORE),
2579                OPT_BIT('f', "show-name", &output_option, N_("Show original filename (Default: auto)"), OUTPUT_SHOW_NAME),
2580                OPT_BIT('n', "show-number", &output_option, N_("Show original linenumber (Default: off)"), OUTPUT_SHOW_NUMBER),
2581                OPT_BIT('p', "porcelain", &output_option, N_("Show in a format designed for machine consumption"), OUTPUT_PORCELAIN),
2582                OPT_BIT(0, "line-porcelain", &output_option, N_("Show porcelain format with per-line commit information"), OUTPUT_PORCELAIN|OUTPUT_LINE_PORCELAIN),
2583                OPT_BIT('c', NULL, &output_option, N_("Use the same output mode as git-annotate (Default: off)"), OUTPUT_ANNOTATE_COMPAT),
2584                OPT_BIT('t', NULL, &output_option, N_("Show raw timestamp (Default: off)"), OUTPUT_RAW_TIMESTAMP),
2585                OPT_BIT('l', NULL, &output_option, N_("Show long commit SHA1 (Default: off)"), OUTPUT_LONG_OBJECT_NAME),
2586                OPT_BIT('s', NULL, &output_option, N_("Suppress author name and timestamp (Default: off)"), OUTPUT_NO_AUTHOR),
2587                OPT_BIT('e', "show-email", &output_option, N_("Show author email instead of name (Default: off)"), OUTPUT_SHOW_EMAIL),
2588                OPT_BIT('w', NULL, &xdl_opts, N_("Ignore whitespace differences"), XDF_IGNORE_WHITESPACE),
2589
2590                /*
2591                 * The following two options are parsed by parse_revision_opt()
2592                 * and are only included here to get included in the "-h"
2593                 * output:
2594                 */
2595                { OPTION_LOWLEVEL_CALLBACK, 0, "indent-heuristic", NULL, NULL, N_("Use an experimental heuristic to improve diffs"), PARSE_OPT_NOARG, parse_opt_unknown_cb },
2596
2597                OPT_BIT(0, "minimal", &xdl_opts, N_("Spend extra cycles to find better match"), XDF_NEED_MINIMAL),
2598                OPT_STRING('S', NULL, &revs_file, N_("file"), N_("Use revisions from <file> instead of calling git-rev-list")),
2599                OPT_STRING(0, "contents", &contents_from, N_("file"), N_("Use <file>'s contents as the final image")),
2600                { OPTION_CALLBACK, 'C', NULL, &opt, N_("score"), N_("Find line copies within and across files"), PARSE_OPT_OPTARG, blame_copy_callback },
2601                { OPTION_CALLBACK, 'M', NULL, &opt, N_("score"), N_("Find line movements within and across files"), PARSE_OPT_OPTARG, blame_move_callback },
2602                OPT_STRING_LIST('L', NULL, &range_list, N_("n,m"), N_("Process only line range n,m, counting from 1")),
2603                OPT__ABBREV(&abbrev),
2604                OPT_END()
2605        };
2606
2607        struct parse_opt_ctx_t ctx;
2608        int cmd_is_annotate = !strcmp(argv[0], "annotate");
2609        struct range_set ranges;
2610        unsigned int range_i;
2611        long anchor;
2612
2613        git_config(git_blame_config, &output_option);
2614        init_revisions(&revs, NULL);
2615        revs.date_mode = blame_date_mode;
2616        DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
2617        DIFF_OPT_SET(&revs.diffopt, FOLLOW_RENAMES);
2618
2619        save_commit_buffer = 0;
2620        dashdash_pos = 0;
2621        show_progress = -1;
2622
2623        parse_options_start(&ctx, argc, argv, prefix, options,
2624                            PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);
2625        for (;;) {
2626                switch (parse_options_step(&ctx, options, blame_opt_usage)) {
2627                case PARSE_OPT_HELP:
2628                        exit(129);
2629                case PARSE_OPT_DONE:
2630                        if (ctx.argv[0])
2631                                dashdash_pos = ctx.cpidx;
2632                        goto parse_done;
2633                }
2634
2635                if (!strcmp(ctx.argv[0], "--reverse")) {
2636                        ctx.argv[0] = "--children";
2637                        reverse = 1;
2638                }
2639                parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
2640        }
2641parse_done:
2642        no_whole_file_rename = !DIFF_OPT_TST(&revs.diffopt, FOLLOW_RENAMES);
2643        xdl_opts |= revs.diffopt.xdl_opts & XDF_INDENT_HEURISTIC;
2644        DIFF_OPT_CLR(&revs.diffopt, FOLLOW_RENAMES);
2645        argc = parse_options_end(&ctx);
2646
2647        if (incremental || (output_option & OUTPUT_PORCELAIN)) {
2648                if (show_progress > 0)
2649                        die(_("--progress can't be used with --incremental or porcelain formats"));
2650                show_progress = 0;
2651        } else if (show_progress < 0)
2652                show_progress = isatty(2);
2653
2654        if (0 < abbrev && abbrev < GIT_SHA1_HEXSZ)
2655                /* one more abbrev length is needed for the boundary commit */
2656                abbrev++;
2657        else if (!abbrev)
2658                abbrev = GIT_SHA1_HEXSZ;
2659
2660        if (revs_file && read_ancestry(revs_file))
2661                die_errno("reading graft file '%s' failed", revs_file);
2662
2663        if (cmd_is_annotate) {
2664                output_option |= OUTPUT_ANNOTATE_COMPAT;
2665                blame_date_mode.type = DATE_ISO8601;
2666        } else {
2667                blame_date_mode = revs.date_mode;
2668        }
2669
2670        /* The maximum width used to show the dates */
2671        switch (blame_date_mode.type) {
2672        case DATE_RFC2822:
2673                blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
2674                break;
2675        case DATE_ISO8601_STRICT:
2676                blame_date_width = sizeof("2006-10-19T16:00:04-07:00");
2677                break;
2678        case DATE_ISO8601:
2679                blame_date_width = sizeof("2006-10-19 16:00:04 -0700");
2680                break;
2681        case DATE_RAW:
2682                blame_date_width = sizeof("1161298804 -0700");
2683                break;
2684        case DATE_UNIX:
2685                blame_date_width = sizeof("1161298804");
2686                break;
2687        case DATE_SHORT:
2688                blame_date_width = sizeof("2006-10-19");
2689                break;
2690        case DATE_RELATIVE:
2691                /* TRANSLATORS: This string is used to tell us the maximum
2692                   display width for a relative timestamp in "git blame"
2693                   output.  For C locale, "4 years, 11 months ago", which
2694                   takes 22 places, is the longest among various forms of
2695                   relative timestamps, but your language may need more or
2696                   fewer display columns. */
2697                blame_date_width = utf8_strwidth(_("4 years, 11 months ago")) + 1; /* add the null */
2698                break;
2699        case DATE_NORMAL:
2700                blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
2701                break;
2702        case DATE_STRFTIME:
2703                blame_date_width = strlen(show_date(0, 0, &blame_date_mode)) + 1; /* add the null */
2704                break;
2705        }
2706        blame_date_width -= 1; /* strip the null */
2707
2708        if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
2709                opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
2710                        PICKAXE_BLAME_COPY_HARDER);
2711
2712        if (!blame_move_score)
2713                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2714        if (!blame_copy_score)
2715                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2716
2717        /*
2718         * We have collected options unknown to us in argv[1..unk]
2719         * which are to be passed to revision machinery if we are
2720         * going to do the "bottom" processing.
2721         *
2722         * The remaining are:
2723         *
2724         * (1) if dashdash_pos != 0, it is either
2725         *     "blame [revisions] -- <path>" or
2726         *     "blame -- <path> <rev>"
2727         *
2728         * (2) otherwise, it is one of the two:
2729         *     "blame [revisions] <path>"
2730         *     "blame <path> <rev>"
2731         *
2732         * Note that we must strip out <path> from the arguments: we do not
2733         * want the path pruning but we may want "bottom" processing.
2734         */
2735        if (dashdash_pos) {
2736                switch (argc - dashdash_pos - 1) {
2737                case 2: /* (1b) */
2738                        if (argc != 4)
2739                                usage_with_options(blame_opt_usage, options);
2740                        /* reorder for the new way: <rev> -- <path> */
2741                        argv[1] = argv[3];
2742                        argv[3] = argv[2];
2743                        argv[2] = "--";
2744                        /* FALLTHROUGH */
2745                case 1: /* (1a) */
2746                        path = add_prefix(prefix, argv[--argc]);
2747                        argv[argc] = NULL;
2748                        break;
2749                default:
2750                        usage_with_options(blame_opt_usage, options);
2751                }
2752        } else {
2753                if (argc < 2)
2754                        usage_with_options(blame_opt_usage, options);
2755                path = add_prefix(prefix, argv[argc - 1]);
2756                if (argc == 3 && !file_exists(path)) { /* (2b) */
2757                        path = add_prefix(prefix, argv[1]);
2758                        argv[1] = argv[2];
2759                }
2760                argv[argc - 1] = "--";
2761
2762                setup_work_tree();
2763                if (!file_exists(path))
2764                        die_errno("cannot stat path '%s'", path);
2765        }
2766
2767        revs.disable_stdin = 1;
2768        setup_revisions(argc, argv, &revs, NULL);
2769        memset(&sb, 0, sizeof(sb));
2770
2771        sb.revs = &revs;
2772        if (!reverse) {
2773                final_commit_name = prepare_final(&sb);
2774                sb.commits.compare = compare_commits_by_commit_date;
2775        }
2776        else if (contents_from)
2777                die(_("--contents and --reverse do not blend well."));
2778        else {
2779                final_commit_name = prepare_initial(&sb);
2780                sb.commits.compare = compare_commits_by_reverse_commit_date;
2781                if (revs.first_parent_only)
2782                        revs.children.name = NULL;
2783        }
2784
2785        if (!sb.final) {
2786                /*
2787                 * "--not A B -- path" without anything positive;
2788                 * do not default to HEAD, but use the working tree
2789                 * or "--contents".
2790                 */
2791                setup_work_tree();
2792                sb.final = fake_working_tree_commit(&sb.revs->diffopt,
2793                                                    path, contents_from);
2794                add_pending_object(&revs, &(sb.final->object), ":");
2795        }
2796        else if (contents_from)
2797                die(_("cannot use --contents with final commit object name"));
2798
2799        if (reverse && revs.first_parent_only) {
2800                final_commit = find_single_final(sb.revs, NULL);
2801                if (!final_commit)
2802                        die(_("--reverse and --first-parent together require specified latest commit"));
2803        }
2804
2805        /*
2806         * If we have bottom, this will mark the ancestors of the
2807         * bottom commits we would reach while traversing as
2808         * uninteresting.
2809         */
2810        if (prepare_revision_walk(&revs))
2811                die(_("revision walk setup failed"));
2812
2813        if (reverse && revs.first_parent_only) {
2814                struct commit *c = final_commit;
2815
2816                sb.revs->children.name = "children";
2817                while (c->parents &&
2818                       oidcmp(&c->object.oid, &sb.final->object.oid)) {
2819                        struct commit_list *l = xcalloc(1, sizeof(*l));
2820
2821                        l->item = c;
2822                        if (add_decoration(&sb.revs->children,
2823                                           &c->parents->item->object, l))
2824                                die("BUG: not unique item in first-parent chain");
2825                        c = c->parents->item;
2826                }
2827
2828                if (oidcmp(&c->object.oid, &sb.final->object.oid))
2829                        die(_("--reverse --first-parent together require range along first-parent chain"));
2830        }
2831
2832        if (is_null_oid(&sb.final->object.oid)) {
2833                o = sb.final->util;
2834                sb.final_buf = xmemdupz(o->file.ptr, o->file.size);
2835                sb.final_buf_size = o->file.size;
2836        }
2837        else {
2838                o = get_origin(&sb, sb.final, path);
2839                if (fill_blob_sha1_and_mode(o))
2840                        die(_("no such path %s in %s"), path, final_commit_name);
2841
2842                if (DIFF_OPT_TST(&sb.revs->diffopt, ALLOW_TEXTCONV) &&
2843                    textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb.final_buf,
2844                                    &sb.final_buf_size))
2845                        ;
2846                else
2847                        sb.final_buf = read_sha1_file(o->blob_oid.hash, &type,
2848                                                      &sb.final_buf_size);
2849
2850                if (!sb.final_buf)
2851                        die(_("cannot read blob %s for path %s"),
2852                            oid_to_hex(&o->blob_oid),
2853                            path);
2854        }
2855        num_read_blob++;
2856        lno = prepare_lines(&sb);
2857
2858        if (lno && !range_list.nr)
2859                string_list_append(&range_list, "1");
2860
2861        anchor = 1;
2862        range_set_init(&ranges, range_list.nr);
2863        for (range_i = 0; range_i < range_list.nr; ++range_i) {
2864                long bottom, top;
2865                if (parse_range_arg(range_list.items[range_i].string,
2866                                    nth_line_cb, &sb, lno, anchor,
2867                                    &bottom, &top, sb.path))
2868                        usage(blame_usage);
2869                if (lno < top || ((lno || bottom) && lno < bottom))
2870                        die(Q_("file %s has only %lu line",
2871                               "file %s has only %lu lines",
2872                               lno), path, lno);
2873                if (bottom < 1)
2874                        bottom = 1;
2875                if (top < 1)
2876                        top = lno;
2877                bottom--;
2878                range_set_append_unsafe(&ranges, bottom, top);
2879                anchor = top + 1;
2880        }
2881        sort_and_merge_range_set(&ranges);
2882
2883        for (range_i = ranges.nr; range_i > 0; --range_i) {
2884                const struct range *r = &ranges.ranges[range_i - 1];
2885                long bottom = r->start;
2886                long top = r->end;
2887                struct blame_entry *next = ent;
2888                ent = xcalloc(1, sizeof(*ent));
2889                ent->lno = bottom;
2890                ent->num_lines = top - bottom;
2891                ent->suspect = o;
2892                ent->s_lno = bottom;
2893                ent->next = next;
2894                origin_incref(o);
2895        }
2896
2897        o->suspects = ent;
2898        prio_queue_put(&sb.commits, o->commit);
2899
2900        origin_decref(o);
2901
2902        range_set_release(&ranges);
2903        string_list_clear(&range_list, 0);
2904
2905        sb.ent = NULL;
2906        sb.path = path;
2907
2908        read_mailmap(&mailmap, NULL);
2909
2910        assign_blame(&sb, opt);
2911
2912        if (!incremental)
2913                setup_pager();
2914
2915        free(final_commit_name);
2916
2917        if (incremental)
2918                return 0;
2919
2920        sb.ent = blame_sort(sb.ent, compare_blame_final);
2921
2922        coalesce(&sb);
2923
2924        if (!(output_option & OUTPUT_PORCELAIN))
2925                find_alignment(&sb, &output_option);
2926
2927        output(&sb, output_option);
2928        free((void *)sb.final_buf);
2929        for (ent = sb.ent; ent; ) {
2930                struct blame_entry *e = ent->next;
2931                free(ent);
2932                ent = e;
2933        }
2934
2935        if (show_stats) {
2936                printf("num read blob: %d\n", num_read_blob);
2937                printf("num get patch: %d\n", num_get_patch);
2938                printf("num commits: %d\n", num_commits);
2939        }
2940        return 0;
2941}