builtin-blame.con commit Merge branch 'jc/maint-1.6.0-keep-pack' into maint (c3067cb)
   1/*
   2 * Pickaxe
   3 *
   4 * Copyright (c) 2006, Junio C Hamano
   5 */
   6
   7#include "cache.h"
   8#include "builtin.h"
   9#include "blob.h"
  10#include "commit.h"
  11#include "tag.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "revision.h"
  16#include "quote.h"
  17#include "xdiff-interface.h"
  18#include "cache-tree.h"
  19#include "string-list.h"
  20#include "mailmap.h"
  21#include "parse-options.h"
  22#include "utf8.h"
  23
  24static char blame_usage[] = "git blame [options] [rev-opts] [rev] [--] file";
  25
  26static const char *blame_opt_usage[] = {
  27        blame_usage,
  28        "",
  29        "[rev-opts] are documented in git-rev-list(1)",
  30        NULL
  31};
  32
  33static int longest_file;
  34static int longest_author;
  35static int max_orig_digits;
  36static int max_digits;
  37static int max_score_digits;
  38static int show_root;
  39static int reverse;
  40static int blank_boundary;
  41static int incremental;
  42static int xdl_opts = XDF_NEED_MINIMAL;
  43static struct string_list mailmap;
  44
  45#ifndef DEBUG
  46#define DEBUG 0
  47#endif
  48
  49/* stats */
  50static int num_read_blob;
  51static int num_get_patch;
  52static int num_commits;
  53
  54#define PICKAXE_BLAME_MOVE              01
  55#define PICKAXE_BLAME_COPY              02
  56#define PICKAXE_BLAME_COPY_HARDER       04
  57#define PICKAXE_BLAME_COPY_HARDEST      010
  58
  59/*
  60 * blame for a blame_entry with score lower than these thresholds
  61 * is not passed to the parent using move/copy logic.
  62 */
  63static unsigned blame_move_score;
  64static unsigned blame_copy_score;
  65#define BLAME_DEFAULT_MOVE_SCORE        20
  66#define BLAME_DEFAULT_COPY_SCORE        40
  67
  68/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  69#define METAINFO_SHOWN          (1u<<12)
  70#define MORE_THAN_ONE_PATH      (1u<<13)
  71
  72/*
  73 * One blob in a commit that is being suspected
  74 */
  75struct origin {
  76        int refcnt;
  77        struct commit *commit;
  78        mmfile_t file;
  79        unsigned char blob_sha1[20];
  80        char path[FLEX_ARRAY];
  81};
  82
  83/*
  84 * Given an origin, prepare mmfile_t structure to be used by the
  85 * diff machinery
  86 */
  87static void fill_origin_blob(struct origin *o, mmfile_t *file)
  88{
  89        if (!o->file.ptr) {
  90                enum object_type type;
  91                num_read_blob++;
  92                file->ptr = read_sha1_file(o->blob_sha1, &type,
  93                                           (unsigned long *)(&(file->size)));
  94                if (!file->ptr)
  95                        die("Cannot read blob %s for path %s",
  96                            sha1_to_hex(o->blob_sha1),
  97                            o->path);
  98                o->file = *file;
  99        }
 100        else
 101                *file = o->file;
 102}
 103
 104/*
 105 * Origin is refcounted and usually we keep the blob contents to be
 106 * reused.
 107 */
 108static inline struct origin *origin_incref(struct origin *o)
 109{
 110        if (o)
 111                o->refcnt++;
 112        return o;
 113}
 114
 115static void origin_decref(struct origin *o)
 116{
 117        if (o && --o->refcnt <= 0) {
 118                free(o->file.ptr);
 119                free(o);
 120        }
 121}
 122
 123static void drop_origin_blob(struct origin *o)
 124{
 125        if (o->file.ptr) {
 126                free(o->file.ptr);
 127                o->file.ptr = NULL;
 128        }
 129}
 130
 131/*
 132 * Each group of lines is described by a blame_entry; it can be split
 133 * as we pass blame to the parents.  They form a linked list in the
 134 * scoreboard structure, sorted by the target line number.
 135 */
 136struct blame_entry {
 137        struct blame_entry *prev;
 138        struct blame_entry *next;
 139
 140        /* the first line of this group in the final image;
 141         * internally all line numbers are 0 based.
 142         */
 143        int lno;
 144
 145        /* how many lines this group has */
 146        int num_lines;
 147
 148        /* the commit that introduced this group into the final image */
 149        struct origin *suspect;
 150
 151        /* true if the suspect is truly guilty; false while we have not
 152         * checked if the group came from one of its parents.
 153         */
 154        char guilty;
 155
 156        /* true if the entry has been scanned for copies in the current parent
 157         */
 158        char scanned;
 159
 160        /* the line number of the first line of this group in the
 161         * suspect's file; internally all line numbers are 0 based.
 162         */
 163        int s_lno;
 164
 165        /* how significant this entry is -- cached to avoid
 166         * scanning the lines over and over.
 167         */
 168        unsigned score;
 169};
 170
 171/*
 172 * The current state of the blame assignment.
 173 */
 174struct scoreboard {
 175        /* the final commit (i.e. where we started digging from) */
 176        struct commit *final;
 177        struct rev_info *revs;
 178        const char *path;
 179
 180        /*
 181         * The contents in the final image.
 182         * Used by many functions to obtain contents of the nth line,
 183         * indexed with scoreboard.lineno[blame_entry.lno].
 184         */
 185        const char *final_buf;
 186        unsigned long final_buf_size;
 187
 188        /* linked list of blames */
 189        struct blame_entry *ent;
 190
 191        /* look-up a line in the final buffer */
 192        int num_lines;
 193        int *lineno;
 194};
 195
 196static inline int same_suspect(struct origin *a, struct origin *b)
 197{
 198        if (a == b)
 199                return 1;
 200        if (a->commit != b->commit)
 201                return 0;
 202        return !strcmp(a->path, b->path);
 203}
 204
 205static void sanity_check_refcnt(struct scoreboard *);
 206
 207/*
 208 * If two blame entries that are next to each other came from
 209 * contiguous lines in the same origin (i.e. <commit, path> pair),
 210 * merge them together.
 211 */
 212static void coalesce(struct scoreboard *sb)
 213{
 214        struct blame_entry *ent, *next;
 215
 216        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 217                if (same_suspect(ent->suspect, next->suspect) &&
 218                    ent->guilty == next->guilty &&
 219                    ent->s_lno + ent->num_lines == next->s_lno) {
 220                        ent->num_lines += next->num_lines;
 221                        ent->next = next->next;
 222                        if (ent->next)
 223                                ent->next->prev = ent;
 224                        origin_decref(next->suspect);
 225                        free(next);
 226                        ent->score = 0;
 227                        next = ent; /* again */
 228                }
 229        }
 230
 231        if (DEBUG) /* sanity */
 232                sanity_check_refcnt(sb);
 233}
 234
 235/*
 236 * Given a commit and a path in it, create a new origin structure.
 237 * The callers that add blame to the scoreboard should use
 238 * get_origin() to obtain shared, refcounted copy instead of calling
 239 * this function directly.
 240 */
 241static struct origin *make_origin(struct commit *commit, const char *path)
 242{
 243        struct origin *o;
 244        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 245        o->commit = commit;
 246        o->refcnt = 1;
 247        strcpy(o->path, path);
 248        return o;
 249}
 250
 251/*
 252 * Locate an existing origin or create a new one.
 253 */
 254static struct origin *get_origin(struct scoreboard *sb,
 255                                 struct commit *commit,
 256                                 const char *path)
 257{
 258        struct blame_entry *e;
 259
 260        for (e = sb->ent; e; e = e->next) {
 261                if (e->suspect->commit == commit &&
 262                    !strcmp(e->suspect->path, path))
 263                        return origin_incref(e->suspect);
 264        }
 265        return make_origin(commit, path);
 266}
 267
 268/*
 269 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 270 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 271 * for an origin is also used to pass the blame for the entire file to
 272 * the parent to detect the case where a child's blob is identical to
 273 * that of its parent's.
 274 */
 275static int fill_blob_sha1(struct origin *origin)
 276{
 277        unsigned mode;
 278
 279        if (!is_null_sha1(origin->blob_sha1))
 280                return 0;
 281        if (get_tree_entry(origin->commit->object.sha1,
 282                           origin->path,
 283                           origin->blob_sha1, &mode))
 284                goto error_out;
 285        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 286                goto error_out;
 287        return 0;
 288 error_out:
 289        hashclr(origin->blob_sha1);
 290        return -1;
 291}
 292
 293/*
 294 * We have an origin -- check if the same path exists in the
 295 * parent and return an origin structure to represent it.
 296 */
 297static struct origin *find_origin(struct scoreboard *sb,
 298                                  struct commit *parent,
 299                                  struct origin *origin)
 300{
 301        struct origin *porigin = NULL;
 302        struct diff_options diff_opts;
 303        const char *paths[2];
 304
 305        if (parent->util) {
 306                /*
 307                 * Each commit object can cache one origin in that
 308                 * commit.  This is a freestanding copy of origin and
 309                 * not refcounted.
 310                 */
 311                struct origin *cached = parent->util;
 312                if (!strcmp(cached->path, origin->path)) {
 313                        /*
 314                         * The same path between origin and its parent
 315                         * without renaming -- the most common case.
 316                         */
 317                        porigin = get_origin(sb, parent, cached->path);
 318
 319                        /*
 320                         * If the origin was newly created (i.e. get_origin
 321                         * would call make_origin if none is found in the
 322                         * scoreboard), it does not know the blob_sha1,
 323                         * so copy it.  Otherwise porigin was in the
 324                         * scoreboard and already knows blob_sha1.
 325                         */
 326                        if (porigin->refcnt == 1)
 327                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 328                        return porigin;
 329                }
 330                /* otherwise it was not very useful; free it */
 331                free(parent->util);
 332                parent->util = NULL;
 333        }
 334
 335        /* See if the origin->path is different between parent
 336         * and origin first.  Most of the time they are the
 337         * same and diff-tree is fairly efficient about this.
 338         */
 339        diff_setup(&diff_opts);
 340        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 341        diff_opts.detect_rename = 0;
 342        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 343        paths[0] = origin->path;
 344        paths[1] = NULL;
 345
 346        diff_tree_setup_paths(paths, &diff_opts);
 347        if (diff_setup_done(&diff_opts) < 0)
 348                die("diff-setup");
 349
 350        if (is_null_sha1(origin->commit->object.sha1))
 351                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 352        else
 353                diff_tree_sha1(parent->tree->object.sha1,
 354                               origin->commit->tree->object.sha1,
 355                               "", &diff_opts);
 356        diffcore_std(&diff_opts);
 357
 358        /* It is either one entry that says "modified", or "created",
 359         * or nothing.
 360         */
 361        if (!diff_queued_diff.nr) {
 362                /* The path is the same as parent */
 363                porigin = get_origin(sb, parent, origin->path);
 364                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 365        }
 366        else if (diff_queued_diff.nr != 1)
 367                die("internal error in blame::find_origin");
 368        else {
 369                struct diff_filepair *p = diff_queued_diff.queue[0];
 370                switch (p->status) {
 371                default:
 372                        die("internal error in blame::find_origin (%c)",
 373                            p->status);
 374                case 'M':
 375                        porigin = get_origin(sb, parent, origin->path);
 376                        hashcpy(porigin->blob_sha1, p->one->sha1);
 377                        break;
 378                case 'A':
 379                case 'T':
 380                        /* Did not exist in parent, or type changed */
 381                        break;
 382                }
 383        }
 384        diff_flush(&diff_opts);
 385        diff_tree_release_paths(&diff_opts);
 386        if (porigin) {
 387                /*
 388                 * Create a freestanding copy that is not part of
 389                 * the refcounted origin found in the scoreboard, and
 390                 * cache it in the commit.
 391                 */
 392                struct origin *cached;
 393
 394                cached = make_origin(porigin->commit, porigin->path);
 395                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 396                parent->util = cached;
 397        }
 398        return porigin;
 399}
 400
 401/*
 402 * We have an origin -- find the path that corresponds to it in its
 403 * parent and return an origin structure to represent it.
 404 */
 405static struct origin *find_rename(struct scoreboard *sb,
 406                                  struct commit *parent,
 407                                  struct origin *origin)
 408{
 409        struct origin *porigin = NULL;
 410        struct diff_options diff_opts;
 411        int i;
 412        const char *paths[2];
 413
 414        diff_setup(&diff_opts);
 415        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 416        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 417        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 418        diff_opts.single_follow = origin->path;
 419        paths[0] = NULL;
 420        diff_tree_setup_paths(paths, &diff_opts);
 421        if (diff_setup_done(&diff_opts) < 0)
 422                die("diff-setup");
 423
 424        if (is_null_sha1(origin->commit->object.sha1))
 425                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 426        else
 427                diff_tree_sha1(parent->tree->object.sha1,
 428                               origin->commit->tree->object.sha1,
 429                               "", &diff_opts);
 430        diffcore_std(&diff_opts);
 431
 432        for (i = 0; i < diff_queued_diff.nr; i++) {
 433                struct diff_filepair *p = diff_queued_diff.queue[i];
 434                if ((p->status == 'R' || p->status == 'C') &&
 435                    !strcmp(p->two->path, origin->path)) {
 436                        porigin = get_origin(sb, parent, p->one->path);
 437                        hashcpy(porigin->blob_sha1, p->one->sha1);
 438                        break;
 439                }
 440        }
 441        diff_flush(&diff_opts);
 442        diff_tree_release_paths(&diff_opts);
 443        return porigin;
 444}
 445
 446/*
 447 * Link in a new blame entry to the scoreboard.  Entries that cover the
 448 * same line range have been removed from the scoreboard previously.
 449 */
 450static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 451{
 452        struct blame_entry *ent, *prev = NULL;
 453
 454        origin_incref(e->suspect);
 455
 456        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 457                prev = ent;
 458
 459        /* prev, if not NULL, is the last one that is below e */
 460        e->prev = prev;
 461        if (prev) {
 462                e->next = prev->next;
 463                prev->next = e;
 464        }
 465        else {
 466                e->next = sb->ent;
 467                sb->ent = e;
 468        }
 469        if (e->next)
 470                e->next->prev = e;
 471}
 472
 473/*
 474 * src typically is on-stack; we want to copy the information in it to
 475 * a malloced blame_entry that is already on the linked list of the
 476 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 477 * gains one.
 478 */
 479static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 480{
 481        struct blame_entry *p, *n;
 482
 483        p = dst->prev;
 484        n = dst->next;
 485        origin_incref(src->suspect);
 486        origin_decref(dst->suspect);
 487        memcpy(dst, src, sizeof(*src));
 488        dst->prev = p;
 489        dst->next = n;
 490        dst->score = 0;
 491}
 492
 493static const char *nth_line(struct scoreboard *sb, int lno)
 494{
 495        return sb->final_buf + sb->lineno[lno];
 496}
 497
 498/*
 499 * It is known that lines between tlno to same came from parent, and e
 500 * has an overlap with that range.  it also is known that parent's
 501 * line plno corresponds to e's line tlno.
 502 *
 503 *                <---- e ----->
 504 *                   <------>
 505 *                   <------------>
 506 *             <------------>
 507 *             <------------------>
 508 *
 509 * Split e into potentially three parts; before this chunk, the chunk
 510 * to be blamed for the parent, and after that portion.
 511 */
 512static void split_overlap(struct blame_entry *split,
 513                          struct blame_entry *e,
 514                          int tlno, int plno, int same,
 515                          struct origin *parent)
 516{
 517        int chunk_end_lno;
 518        memset(split, 0, sizeof(struct blame_entry [3]));
 519
 520        if (e->s_lno < tlno) {
 521                /* there is a pre-chunk part not blamed on parent */
 522                split[0].suspect = origin_incref(e->suspect);
 523                split[0].lno = e->lno;
 524                split[0].s_lno = e->s_lno;
 525                split[0].num_lines = tlno - e->s_lno;
 526                split[1].lno = e->lno + tlno - e->s_lno;
 527                split[1].s_lno = plno;
 528        }
 529        else {
 530                split[1].lno = e->lno;
 531                split[1].s_lno = plno + (e->s_lno - tlno);
 532        }
 533
 534        if (same < e->s_lno + e->num_lines) {
 535                /* there is a post-chunk part not blamed on parent */
 536                split[2].suspect = origin_incref(e->suspect);
 537                split[2].lno = e->lno + (same - e->s_lno);
 538                split[2].s_lno = e->s_lno + (same - e->s_lno);
 539                split[2].num_lines = e->s_lno + e->num_lines - same;
 540                chunk_end_lno = split[2].lno;
 541        }
 542        else
 543                chunk_end_lno = e->lno + e->num_lines;
 544        split[1].num_lines = chunk_end_lno - split[1].lno;
 545
 546        /*
 547         * if it turns out there is nothing to blame the parent for,
 548         * forget about the splitting.  !split[1].suspect signals this.
 549         */
 550        if (split[1].num_lines < 1)
 551                return;
 552        split[1].suspect = origin_incref(parent);
 553}
 554
 555/*
 556 * split_overlap() divided an existing blame e into up to three parts
 557 * in split.  Adjust the linked list of blames in the scoreboard to
 558 * reflect the split.
 559 */
 560static void split_blame(struct scoreboard *sb,
 561                        struct blame_entry *split,
 562                        struct blame_entry *e)
 563{
 564        struct blame_entry *new_entry;
 565
 566        if (split[0].suspect && split[2].suspect) {
 567                /* The first part (reuse storage for the existing entry e) */
 568                dup_entry(e, &split[0]);
 569
 570                /* The last part -- me */
 571                new_entry = xmalloc(sizeof(*new_entry));
 572                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 573                add_blame_entry(sb, new_entry);
 574
 575                /* ... and the middle part -- parent */
 576                new_entry = xmalloc(sizeof(*new_entry));
 577                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 578                add_blame_entry(sb, new_entry);
 579        }
 580        else if (!split[0].suspect && !split[2].suspect)
 581                /*
 582                 * The parent covers the entire area; reuse storage for
 583                 * e and replace it with the parent.
 584                 */
 585                dup_entry(e, &split[1]);
 586        else if (split[0].suspect) {
 587                /* me and then parent */
 588                dup_entry(e, &split[0]);
 589
 590                new_entry = xmalloc(sizeof(*new_entry));
 591                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 592                add_blame_entry(sb, new_entry);
 593        }
 594        else {
 595                /* parent and then me */
 596                dup_entry(e, &split[1]);
 597
 598                new_entry = xmalloc(sizeof(*new_entry));
 599                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 600                add_blame_entry(sb, new_entry);
 601        }
 602
 603        if (DEBUG) { /* sanity */
 604                struct blame_entry *ent;
 605                int lno = sb->ent->lno, corrupt = 0;
 606
 607                for (ent = sb->ent; ent; ent = ent->next) {
 608                        if (lno != ent->lno)
 609                                corrupt = 1;
 610                        if (ent->s_lno < 0)
 611                                corrupt = 1;
 612                        lno += ent->num_lines;
 613                }
 614                if (corrupt) {
 615                        lno = sb->ent->lno;
 616                        for (ent = sb->ent; ent; ent = ent->next) {
 617                                printf("L %8d l %8d n %8d\n",
 618                                       lno, ent->lno, ent->num_lines);
 619                                lno = ent->lno + ent->num_lines;
 620                        }
 621                        die("oops");
 622                }
 623        }
 624}
 625
 626/*
 627 * After splitting the blame, the origins used by the
 628 * on-stack blame_entry should lose one refcnt each.
 629 */
 630static void decref_split(struct blame_entry *split)
 631{
 632        int i;
 633
 634        for (i = 0; i < 3; i++)
 635                origin_decref(split[i].suspect);
 636}
 637
 638/*
 639 * Helper for blame_chunk().  blame_entry e is known to overlap with
 640 * the patch hunk; split it and pass blame to the parent.
 641 */
 642static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 643                          int tlno, int plno, int same,
 644                          struct origin *parent)
 645{
 646        struct blame_entry split[3];
 647
 648        split_overlap(split, e, tlno, plno, same, parent);
 649        if (split[1].suspect)
 650                split_blame(sb, split, e);
 651        decref_split(split);
 652}
 653
 654/*
 655 * Find the line number of the last line the target is suspected for.
 656 */
 657static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 658{
 659        struct blame_entry *e;
 660        int last_in_target = -1;
 661
 662        for (e = sb->ent; e; e = e->next) {
 663                if (e->guilty || !same_suspect(e->suspect, target))
 664                        continue;
 665                if (last_in_target < e->s_lno + e->num_lines)
 666                        last_in_target = e->s_lno + e->num_lines;
 667        }
 668        return last_in_target;
 669}
 670
 671/*
 672 * Process one hunk from the patch between the current suspect for
 673 * blame_entry e and its parent.  Find and split the overlap, and
 674 * pass blame to the overlapping part to the parent.
 675 */
 676static void blame_chunk(struct scoreboard *sb,
 677                        int tlno, int plno, int same,
 678                        struct origin *target, struct origin *parent)
 679{
 680        struct blame_entry *e;
 681
 682        for (e = sb->ent; e; e = e->next) {
 683                if (e->guilty || !same_suspect(e->suspect, target))
 684                        continue;
 685                if (same <= e->s_lno)
 686                        continue;
 687                if (tlno < e->s_lno + e->num_lines)
 688                        blame_overlap(sb, e, tlno, plno, same, parent);
 689        }
 690}
 691
 692struct blame_chunk_cb_data {
 693        struct scoreboard *sb;
 694        struct origin *target;
 695        struct origin *parent;
 696        long plno;
 697        long tlno;
 698};
 699
 700static void blame_chunk_cb(void *data, long same, long p_next, long t_next)
 701{
 702        struct blame_chunk_cb_data *d = data;
 703        blame_chunk(d->sb, d->tlno, d->plno, same, d->target, d->parent);
 704        d->plno = p_next;
 705        d->tlno = t_next;
 706}
 707
 708/*
 709 * We are looking at the origin 'target' and aiming to pass blame
 710 * for the lines it is suspected to its parent.  Run diff to find
 711 * which lines came from parent and pass blame for them.
 712 */
 713static int pass_blame_to_parent(struct scoreboard *sb,
 714                                struct origin *target,
 715                                struct origin *parent)
 716{
 717        int last_in_target;
 718        mmfile_t file_p, file_o;
 719        struct blame_chunk_cb_data d = { sb, target, parent, 0, 0 };
 720        xpparam_t xpp;
 721        xdemitconf_t xecfg;
 722
 723        last_in_target = find_last_in_target(sb, target);
 724        if (last_in_target < 0)
 725                return 1; /* nothing remains for this target */
 726
 727        fill_origin_blob(parent, &file_p);
 728        fill_origin_blob(target, &file_o);
 729        num_get_patch++;
 730
 731        memset(&xpp, 0, sizeof(xpp));
 732        xpp.flags = xdl_opts;
 733        memset(&xecfg, 0, sizeof(xecfg));
 734        xecfg.ctxlen = 0;
 735        xdi_diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, &xpp, &xecfg);
 736        /* The rest (i.e. anything after tlno) are the same as the parent */
 737        blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
 738
 739        return 0;
 740}
 741
 742/*
 743 * The lines in blame_entry after splitting blames many times can become
 744 * very small and trivial, and at some point it becomes pointless to
 745 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 746 * ordinary C program, and it is not worth to say it was copied from
 747 * totally unrelated file in the parent.
 748 *
 749 * Compute how trivial the lines in the blame_entry are.
 750 */
 751static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 752{
 753        unsigned score;
 754        const char *cp, *ep;
 755
 756        if (e->score)
 757                return e->score;
 758
 759        score = 1;
 760        cp = nth_line(sb, e->lno);
 761        ep = nth_line(sb, e->lno + e->num_lines);
 762        while (cp < ep) {
 763                unsigned ch = *((unsigned char *)cp);
 764                if (isalnum(ch))
 765                        score++;
 766                cp++;
 767        }
 768        e->score = score;
 769        return score;
 770}
 771
 772/*
 773 * best_so_far[] and this[] are both a split of an existing blame_entry
 774 * that passes blame to the parent.  Maintain best_so_far the best split
 775 * so far, by comparing this and best_so_far and copying this into
 776 * bst_so_far as needed.
 777 */
 778static void copy_split_if_better(struct scoreboard *sb,
 779                                 struct blame_entry *best_so_far,
 780                                 struct blame_entry *this)
 781{
 782        int i;
 783
 784        if (!this[1].suspect)
 785                return;
 786        if (best_so_far[1].suspect) {
 787                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 788                        return;
 789        }
 790
 791        for (i = 0; i < 3; i++)
 792                origin_incref(this[i].suspect);
 793        decref_split(best_so_far);
 794        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 795}
 796
 797/*
 798 * We are looking at a part of the final image represented by
 799 * ent (tlno and same are offset by ent->s_lno).
 800 * tlno is where we are looking at in the final image.
 801 * up to (but not including) same match preimage.
 802 * plno is where we are looking at in the preimage.
 803 *
 804 * <-------------- final image ---------------------->
 805 *       <------ent------>
 806 *         ^tlno ^same
 807 *    <---------preimage----->
 808 *         ^plno
 809 *
 810 * All line numbers are 0-based.
 811 */
 812static void handle_split(struct scoreboard *sb,
 813                         struct blame_entry *ent,
 814                         int tlno, int plno, int same,
 815                         struct origin *parent,
 816                         struct blame_entry *split)
 817{
 818        if (ent->num_lines <= tlno)
 819                return;
 820        if (tlno < same) {
 821                struct blame_entry this[3];
 822                tlno += ent->s_lno;
 823                same += ent->s_lno;
 824                split_overlap(this, ent, tlno, plno, same, parent);
 825                copy_split_if_better(sb, split, this);
 826                decref_split(this);
 827        }
 828}
 829
 830struct handle_split_cb_data {
 831        struct scoreboard *sb;
 832        struct blame_entry *ent;
 833        struct origin *parent;
 834        struct blame_entry *split;
 835        long plno;
 836        long tlno;
 837};
 838
 839static void handle_split_cb(void *data, long same, long p_next, long t_next)
 840{
 841        struct handle_split_cb_data *d = data;
 842        handle_split(d->sb, d->ent, d->tlno, d->plno, same, d->parent, d->split);
 843        d->plno = p_next;
 844        d->tlno = t_next;
 845}
 846
 847/*
 848 * Find the lines from parent that are the same as ent so that
 849 * we can pass blames to it.  file_p has the blob contents for
 850 * the parent.
 851 */
 852static void find_copy_in_blob(struct scoreboard *sb,
 853                              struct blame_entry *ent,
 854                              struct origin *parent,
 855                              struct blame_entry *split,
 856                              mmfile_t *file_p)
 857{
 858        const char *cp;
 859        int cnt;
 860        mmfile_t file_o;
 861        struct handle_split_cb_data d = { sb, ent, parent, split, 0, 0 };
 862        xpparam_t xpp;
 863        xdemitconf_t xecfg;
 864
 865        /*
 866         * Prepare mmfile that contains only the lines in ent.
 867         */
 868        cp = nth_line(sb, ent->lno);
 869        file_o.ptr = (char*) cp;
 870        cnt = ent->num_lines;
 871
 872        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 873                if (*cp++ == '\n')
 874                        cnt--;
 875        }
 876        file_o.size = cp - file_o.ptr;
 877
 878        /*
 879         * file_o is a part of final image we are annotating.
 880         * file_p partially may match that image.
 881         */
 882        memset(&xpp, 0, sizeof(xpp));
 883        xpp.flags = xdl_opts;
 884        memset(&xecfg, 0, sizeof(xecfg));
 885        xecfg.ctxlen = 1;
 886        memset(split, 0, sizeof(struct blame_entry [3]));
 887        xdi_diff_hunks(file_p, &file_o, handle_split_cb, &d, &xpp, &xecfg);
 888        /* remainder, if any, all match the preimage */
 889        handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
 890}
 891
 892/*
 893 * See if lines currently target is suspected for can be attributed to
 894 * parent.
 895 */
 896static int find_move_in_parent(struct scoreboard *sb,
 897                               struct origin *target,
 898                               struct origin *parent)
 899{
 900        int last_in_target, made_progress;
 901        struct blame_entry *e, split[3];
 902        mmfile_t file_p;
 903
 904        last_in_target = find_last_in_target(sb, target);
 905        if (last_in_target < 0)
 906                return 1; /* nothing remains for this target */
 907
 908        fill_origin_blob(parent, &file_p);
 909        if (!file_p.ptr)
 910                return 0;
 911
 912        made_progress = 1;
 913        while (made_progress) {
 914                made_progress = 0;
 915                for (e = sb->ent; e; e = e->next) {
 916                        if (e->guilty || !same_suspect(e->suspect, target) ||
 917                            ent_score(sb, e) < blame_move_score)
 918                                continue;
 919                        find_copy_in_blob(sb, e, parent, split, &file_p);
 920                        if (split[1].suspect &&
 921                            blame_move_score < ent_score(sb, &split[1])) {
 922                                split_blame(sb, split, e);
 923                                made_progress = 1;
 924                        }
 925                        decref_split(split);
 926                }
 927        }
 928        return 0;
 929}
 930
 931struct blame_list {
 932        struct blame_entry *ent;
 933        struct blame_entry split[3];
 934};
 935
 936/*
 937 * Count the number of entries the target is suspected for,
 938 * and prepare a list of entry and the best split.
 939 */
 940static struct blame_list *setup_blame_list(struct scoreboard *sb,
 941                                           struct origin *target,
 942                                           int min_score,
 943                                           int *num_ents_p)
 944{
 945        struct blame_entry *e;
 946        int num_ents, i;
 947        struct blame_list *blame_list = NULL;
 948
 949        for (e = sb->ent, num_ents = 0; e; e = e->next)
 950                if (!e->scanned && !e->guilty &&
 951                    same_suspect(e->suspect, target) &&
 952                    min_score < ent_score(sb, e))
 953                        num_ents++;
 954        if (num_ents) {
 955                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
 956                for (e = sb->ent, i = 0; e; e = e->next)
 957                        if (!e->scanned && !e->guilty &&
 958                            same_suspect(e->suspect, target) &&
 959                            min_score < ent_score(sb, e))
 960                                blame_list[i++].ent = e;
 961        }
 962        *num_ents_p = num_ents;
 963        return blame_list;
 964}
 965
 966/*
 967 * Reset the scanned status on all entries.
 968 */
 969static void reset_scanned_flag(struct scoreboard *sb)
 970{
 971        struct blame_entry *e;
 972        for (e = sb->ent; e; e = e->next)
 973                e->scanned = 0;
 974}
 975
 976/*
 977 * For lines target is suspected for, see if we can find code movement
 978 * across file boundary from the parent commit.  porigin is the path
 979 * in the parent we already tried.
 980 */
 981static int find_copy_in_parent(struct scoreboard *sb,
 982                               struct origin *target,
 983                               struct commit *parent,
 984                               struct origin *porigin,
 985                               int opt)
 986{
 987        struct diff_options diff_opts;
 988        const char *paths[1];
 989        int i, j;
 990        int retval;
 991        struct blame_list *blame_list;
 992        int num_ents;
 993
 994        blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
 995        if (!blame_list)
 996                return 1; /* nothing remains for this target */
 997
 998        diff_setup(&diff_opts);
 999        DIFF_OPT_SET(&diff_opts, RECURSIVE);
1000        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1001
1002        paths[0] = NULL;
1003        diff_tree_setup_paths(paths, &diff_opts);
1004        if (diff_setup_done(&diff_opts) < 0)
1005                die("diff-setup");
1006
1007        /* Try "find copies harder" on new path if requested;
1008         * we do not want to use diffcore_rename() actually to
1009         * match things up; find_copies_harder is set only to
1010         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1011         * and this code needs to be after diff_setup_done(), which
1012         * usually makes find-copies-harder imply copy detection.
1013         */
1014        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1015            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1016                && (!porigin || strcmp(target->path, porigin->path))))
1017                DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
1018
1019        if (is_null_sha1(target->commit->object.sha1))
1020                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1021        else
1022                diff_tree_sha1(parent->tree->object.sha1,
1023                               target->commit->tree->object.sha1,
1024                               "", &diff_opts);
1025
1026        if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
1027                diffcore_std(&diff_opts);
1028
1029        retval = 0;
1030        while (1) {
1031                int made_progress = 0;
1032
1033                for (i = 0; i < diff_queued_diff.nr; i++) {
1034                        struct diff_filepair *p = diff_queued_diff.queue[i];
1035                        struct origin *norigin;
1036                        mmfile_t file_p;
1037                        struct blame_entry this[3];
1038
1039                        if (!DIFF_FILE_VALID(p->one))
1040                                continue; /* does not exist in parent */
1041                        if (S_ISGITLINK(p->one->mode))
1042                                continue; /* ignore git links */
1043                        if (porigin && !strcmp(p->one->path, porigin->path))
1044                                /* find_move already dealt with this path */
1045                                continue;
1046
1047                        norigin = get_origin(sb, parent, p->one->path);
1048                        hashcpy(norigin->blob_sha1, p->one->sha1);
1049                        fill_origin_blob(norigin, &file_p);
1050                        if (!file_p.ptr)
1051                                continue;
1052
1053                        for (j = 0; j < num_ents; j++) {
1054                                find_copy_in_blob(sb, blame_list[j].ent,
1055                                                  norigin, this, &file_p);
1056                                copy_split_if_better(sb, blame_list[j].split,
1057                                                     this);
1058                                decref_split(this);
1059                        }
1060                        origin_decref(norigin);
1061                }
1062
1063                for (j = 0; j < num_ents; j++) {
1064                        struct blame_entry *split = blame_list[j].split;
1065                        if (split[1].suspect &&
1066                            blame_copy_score < ent_score(sb, &split[1])) {
1067                                split_blame(sb, split, blame_list[j].ent);
1068                                made_progress = 1;
1069                        }
1070                        else
1071                                blame_list[j].ent->scanned = 1;
1072                        decref_split(split);
1073                }
1074                free(blame_list);
1075
1076                if (!made_progress)
1077                        break;
1078                blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
1079                if (!blame_list) {
1080                        retval = 1;
1081                        break;
1082                }
1083        }
1084        reset_scanned_flag(sb);
1085        diff_flush(&diff_opts);
1086        diff_tree_release_paths(&diff_opts);
1087        return retval;
1088}
1089
1090/*
1091 * The blobs of origin and porigin exactly match, so everything
1092 * origin is suspected for can be blamed on the parent.
1093 */
1094static void pass_whole_blame(struct scoreboard *sb,
1095                             struct origin *origin, struct origin *porigin)
1096{
1097        struct blame_entry *e;
1098
1099        if (!porigin->file.ptr && origin->file.ptr) {
1100                /* Steal its file */
1101                porigin->file = origin->file;
1102                origin->file.ptr = NULL;
1103        }
1104        for (e = sb->ent; e; e = e->next) {
1105                if (!same_suspect(e->suspect, origin))
1106                        continue;
1107                origin_incref(porigin);
1108                origin_decref(e->suspect);
1109                e->suspect = porigin;
1110        }
1111}
1112
1113/*
1114 * We pass blame from the current commit to its parents.  We keep saying
1115 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1116 * exonerate ourselves.
1117 */
1118static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
1119{
1120        if (!reverse)
1121                return commit->parents;
1122        return lookup_decoration(&revs->children, &commit->object);
1123}
1124
1125static int num_scapegoats(struct rev_info *revs, struct commit *commit)
1126{
1127        int cnt;
1128        struct commit_list *l = first_scapegoat(revs, commit);
1129        for (cnt = 0; l; l = l->next)
1130                cnt++;
1131        return cnt;
1132}
1133
1134#define MAXSG 16
1135
1136static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1137{
1138        struct rev_info *revs = sb->revs;
1139        int i, pass, num_sg;
1140        struct commit *commit = origin->commit;
1141        struct commit_list *sg;
1142        struct origin *sg_buf[MAXSG];
1143        struct origin *porigin, **sg_origin = sg_buf;
1144
1145        num_sg = num_scapegoats(revs, commit);
1146        if (!num_sg)
1147                goto finish;
1148        else if (num_sg < ARRAY_SIZE(sg_buf))
1149                memset(sg_buf, 0, sizeof(sg_buf));
1150        else
1151                sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1152
1153        /*
1154         * The first pass looks for unrenamed path to optimize for
1155         * common cases, then we look for renames in the second pass.
1156         */
1157        for (pass = 0; pass < 2; pass++) {
1158                struct origin *(*find)(struct scoreboard *,
1159                                       struct commit *, struct origin *);
1160                find = pass ? find_rename : find_origin;
1161
1162                for (i = 0, sg = first_scapegoat(revs, commit);
1163                     i < num_sg && sg;
1164                     sg = sg->next, i++) {
1165                        struct commit *p = sg->item;
1166                        int j, same;
1167
1168                        if (sg_origin[i])
1169                                continue;
1170                        if (parse_commit(p))
1171                                continue;
1172                        porigin = find(sb, p, origin);
1173                        if (!porigin)
1174                                continue;
1175                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1176                                pass_whole_blame(sb, origin, porigin);
1177                                origin_decref(porigin);
1178                                goto finish;
1179                        }
1180                        for (j = same = 0; j < i; j++)
1181                                if (sg_origin[j] &&
1182                                    !hashcmp(sg_origin[j]->blob_sha1,
1183                                             porigin->blob_sha1)) {
1184                                        same = 1;
1185                                        break;
1186                                }
1187                        if (!same)
1188                                sg_origin[i] = porigin;
1189                        else
1190                                origin_decref(porigin);
1191                }
1192        }
1193
1194        num_commits++;
1195        for (i = 0, sg = first_scapegoat(revs, commit);
1196             i < num_sg && sg;
1197             sg = sg->next, i++) {
1198                struct origin *porigin = sg_origin[i];
1199                if (!porigin)
1200                        continue;
1201                if (pass_blame_to_parent(sb, origin, porigin))
1202                        goto finish;
1203        }
1204
1205        /*
1206         * Optionally find moves in parents' files.
1207         */
1208        if (opt & PICKAXE_BLAME_MOVE)
1209                for (i = 0, sg = first_scapegoat(revs, commit);
1210                     i < num_sg && sg;
1211                     sg = sg->next, i++) {
1212                        struct origin *porigin = sg_origin[i];
1213                        if (!porigin)
1214                                continue;
1215                        if (find_move_in_parent(sb, origin, porigin))
1216                                goto finish;
1217                }
1218
1219        /*
1220         * Optionally find copies from parents' files.
1221         */
1222        if (opt & PICKAXE_BLAME_COPY)
1223                for (i = 0, sg = first_scapegoat(revs, commit);
1224                     i < num_sg && sg;
1225                     sg = sg->next, i++) {
1226                        struct origin *porigin = sg_origin[i];
1227                        if (find_copy_in_parent(sb, origin, sg->item,
1228                                                porigin, opt))
1229                                goto finish;
1230                }
1231
1232 finish:
1233        for (i = 0; i < num_sg; i++) {
1234                if (sg_origin[i]) {
1235                        drop_origin_blob(sg_origin[i]);
1236                        origin_decref(sg_origin[i]);
1237                }
1238        }
1239        drop_origin_blob(origin);
1240        if (sg_buf != sg_origin)
1241                free(sg_origin);
1242}
1243
1244/*
1245 * Information on commits, used for output.
1246 */
1247struct commit_info
1248{
1249        const char *author;
1250        const char *author_mail;
1251        unsigned long author_time;
1252        const char *author_tz;
1253
1254        /* filled only when asked for details */
1255        const char *committer;
1256        const char *committer_mail;
1257        unsigned long committer_time;
1258        const char *committer_tz;
1259
1260        const char *summary;
1261};
1262
1263/*
1264 * Parse author/committer line in the commit object buffer
1265 */
1266static void get_ac_line(const char *inbuf, const char *what,
1267                        int person_len, char *person,
1268                        int mail_len, char *mail,
1269                        unsigned long *time, const char **tz)
1270{
1271        int len, tzlen, maillen;
1272        char *tmp, *endp, *timepos, *mailpos;
1273
1274        tmp = strstr(inbuf, what);
1275        if (!tmp)
1276                goto error_out;
1277        tmp += strlen(what);
1278        endp = strchr(tmp, '\n');
1279        if (!endp)
1280                len = strlen(tmp);
1281        else
1282                len = endp - tmp;
1283        if (person_len <= len) {
1284        error_out:
1285                /* Ugh */
1286                *tz = "(unknown)";
1287                strcpy(mail, *tz);
1288                *time = 0;
1289                return;
1290        }
1291        memcpy(person, tmp, len);
1292
1293        tmp = person;
1294        tmp += len;
1295        *tmp = 0;
1296        while (*tmp != ' ')
1297                tmp--;
1298        *tz = tmp+1;
1299        tzlen = (person+len)-(tmp+1);
1300
1301        *tmp = 0;
1302        while (*tmp != ' ')
1303                tmp--;
1304        *time = strtoul(tmp, NULL, 10);
1305        timepos = tmp;
1306
1307        *tmp = 0;
1308        while (*tmp != ' ')
1309                tmp--;
1310        mailpos = tmp + 1;
1311        *tmp = 0;
1312        maillen = timepos - tmp;
1313        memcpy(mail, mailpos, maillen);
1314
1315        if (!mailmap.nr)
1316                return;
1317
1318        /*
1319         * mailmap expansion may make the name longer.
1320         * make room by pushing stuff down.
1321         */
1322        tmp = person + person_len - (tzlen + 1);
1323        memmove(tmp, *tz, tzlen);
1324        tmp[tzlen] = 0;
1325        *tz = tmp;
1326
1327        /*
1328         * Now, convert both name and e-mail using mailmap
1329         */
1330        if(map_user(&mailmap, mail+1, mail_len-1, person, tmp-person-1)) {
1331                /* Add a trailing '>' to email, since map_user returns plain emails
1332                   Note: It already has '<', since we replace from mail+1 */
1333                mailpos = memchr(mail, '\0', mail_len);
1334                if (mailpos && mailpos-mail < mail_len - 1) {
1335                        *mailpos = '>';
1336                        *(mailpos+1) = '\0';
1337                }
1338        }
1339}
1340
1341static void get_commit_info(struct commit *commit,
1342                            struct commit_info *ret,
1343                            int detailed)
1344{
1345        int len;
1346        char *tmp, *endp, *reencoded, *message;
1347        static char author_name[1024];
1348        static char author_mail[1024];
1349        static char committer_name[1024];
1350        static char committer_mail[1024];
1351        static char summary_buf[1024];
1352
1353        /*
1354         * We've operated without save_commit_buffer, so
1355         * we now need to populate them for output.
1356         */
1357        if (!commit->buffer) {
1358                enum object_type type;
1359                unsigned long size;
1360                commit->buffer =
1361                        read_sha1_file(commit->object.sha1, &type, &size);
1362                if (!commit->buffer)
1363                        die("Cannot read commit %s",
1364                            sha1_to_hex(commit->object.sha1));
1365        }
1366        reencoded = reencode_commit_message(commit, NULL);
1367        message   = reencoded ? reencoded : commit->buffer;
1368        ret->author = author_name;
1369        ret->author_mail = author_mail;
1370        get_ac_line(message, "\nauthor ",
1371                    sizeof(author_name), author_name,
1372                    sizeof(author_mail), author_mail,
1373                    &ret->author_time, &ret->author_tz);
1374
1375        if (!detailed) {
1376                free(reencoded);
1377                return;
1378        }
1379
1380        ret->committer = committer_name;
1381        ret->committer_mail = committer_mail;
1382        get_ac_line(message, "\ncommitter ",
1383                    sizeof(committer_name), committer_name,
1384                    sizeof(committer_mail), committer_mail,
1385                    &ret->committer_time, &ret->committer_tz);
1386
1387        ret->summary = summary_buf;
1388        tmp = strstr(message, "\n\n");
1389        if (!tmp) {
1390        error_out:
1391                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1392                free(reencoded);
1393                return;
1394        }
1395        tmp += 2;
1396        endp = strchr(tmp, '\n');
1397        if (!endp)
1398                endp = tmp + strlen(tmp);
1399        len = endp - tmp;
1400        if (len >= sizeof(summary_buf) || len == 0)
1401                goto error_out;
1402        memcpy(summary_buf, tmp, len);
1403        summary_buf[len] = 0;
1404        free(reencoded);
1405}
1406
1407/*
1408 * To allow LF and other nonportable characters in pathnames,
1409 * they are c-style quoted as needed.
1410 */
1411static void write_filename_info(const char *path)
1412{
1413        printf("filename ");
1414        write_name_quoted(path, stdout, '\n');
1415}
1416
1417/*
1418 * The blame_entry is found to be guilty for the range.  Mark it
1419 * as such, and show it in incremental output.
1420 */
1421static void found_guilty_entry(struct blame_entry *ent)
1422{
1423        if (ent->guilty)
1424                return;
1425        ent->guilty = 1;
1426        if (incremental) {
1427                struct origin *suspect = ent->suspect;
1428
1429                printf("%s %d %d %d\n",
1430                       sha1_to_hex(suspect->commit->object.sha1),
1431                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1432                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1433                        struct commit_info ci;
1434                        suspect->commit->object.flags |= METAINFO_SHOWN;
1435                        get_commit_info(suspect->commit, &ci, 1);
1436                        printf("author %s\n", ci.author);
1437                        printf("author-mail %s\n", ci.author_mail);
1438                        printf("author-time %lu\n", ci.author_time);
1439                        printf("author-tz %s\n", ci.author_tz);
1440                        printf("committer %s\n", ci.committer);
1441                        printf("committer-mail %s\n", ci.committer_mail);
1442                        printf("committer-time %lu\n", ci.committer_time);
1443                        printf("committer-tz %s\n", ci.committer_tz);
1444                        printf("summary %s\n", ci.summary);
1445                        if (suspect->commit->object.flags & UNINTERESTING)
1446                                printf("boundary\n");
1447                }
1448                write_filename_info(suspect->path);
1449                maybe_flush_or_die(stdout, "stdout");
1450        }
1451}
1452
1453/*
1454 * The main loop -- while the scoreboard has lines whose true origin
1455 * is still unknown, pick one blame_entry, and allow its current
1456 * suspect to pass blames to its parents.
1457 */
1458static void assign_blame(struct scoreboard *sb, int opt)
1459{
1460        struct rev_info *revs = sb->revs;
1461
1462        while (1) {
1463                struct blame_entry *ent;
1464                struct commit *commit;
1465                struct origin *suspect = NULL;
1466
1467                /* find one suspect to break down */
1468                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1469                        if (!ent->guilty)
1470                                suspect = ent->suspect;
1471                if (!suspect)
1472                        return; /* all done */
1473
1474                /*
1475                 * We will use this suspect later in the loop,
1476                 * so hold onto it in the meantime.
1477                 */
1478                origin_incref(suspect);
1479                commit = suspect->commit;
1480                if (!commit->object.parsed)
1481                        parse_commit(commit);
1482                if (reverse ||
1483                    (!(commit->object.flags & UNINTERESTING) &&
1484                     !(revs->max_age != -1 && commit->date < revs->max_age)))
1485                        pass_blame(sb, suspect, opt);
1486                else {
1487                        commit->object.flags |= UNINTERESTING;
1488                        if (commit->object.parsed)
1489                                mark_parents_uninteresting(commit);
1490                }
1491                /* treat root commit as boundary */
1492                if (!commit->parents && !show_root)
1493                        commit->object.flags |= UNINTERESTING;
1494
1495                /* Take responsibility for the remaining entries */
1496                for (ent = sb->ent; ent; ent = ent->next)
1497                        if (same_suspect(ent->suspect, suspect))
1498                                found_guilty_entry(ent);
1499                origin_decref(suspect);
1500
1501                if (DEBUG) /* sanity */
1502                        sanity_check_refcnt(sb);
1503        }
1504}
1505
1506static const char *format_time(unsigned long time, const char *tz_str,
1507                               int show_raw_time)
1508{
1509        static char time_buf[128];
1510        time_t t = time;
1511        int minutes, tz;
1512        struct tm *tm;
1513
1514        if (show_raw_time) {
1515                sprintf(time_buf, "%lu %s", time, tz_str);
1516                return time_buf;
1517        }
1518
1519        tz = atoi(tz_str);
1520        minutes = tz < 0 ? -tz : tz;
1521        minutes = (minutes / 100)*60 + (minutes % 100);
1522        minutes = tz < 0 ? -minutes : minutes;
1523        t = time + minutes * 60;
1524        tm = gmtime(&t);
1525
1526        strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1527        strcat(time_buf, tz_str);
1528        return time_buf;
1529}
1530
1531#define OUTPUT_ANNOTATE_COMPAT  001
1532#define OUTPUT_LONG_OBJECT_NAME 002
1533#define OUTPUT_RAW_TIMESTAMP    004
1534#define OUTPUT_PORCELAIN        010
1535#define OUTPUT_SHOW_NAME        020
1536#define OUTPUT_SHOW_NUMBER      040
1537#define OUTPUT_SHOW_SCORE      0100
1538#define OUTPUT_NO_AUTHOR       0200
1539
1540static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1541{
1542        int cnt;
1543        const char *cp;
1544        struct origin *suspect = ent->suspect;
1545        char hex[41];
1546
1547        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1548        printf("%s%c%d %d %d\n",
1549               hex,
1550               ent->guilty ? ' ' : '*', // purely for debugging
1551               ent->s_lno + 1,
1552               ent->lno + 1,
1553               ent->num_lines);
1554        if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1555                struct commit_info ci;
1556                suspect->commit->object.flags |= METAINFO_SHOWN;
1557                get_commit_info(suspect->commit, &ci, 1);
1558                printf("author %s\n", ci.author);
1559                printf("author-mail %s\n", ci.author_mail);
1560                printf("author-time %lu\n", ci.author_time);
1561                printf("author-tz %s\n", ci.author_tz);
1562                printf("committer %s\n", ci.committer);
1563                printf("committer-mail %s\n", ci.committer_mail);
1564                printf("committer-time %lu\n", ci.committer_time);
1565                printf("committer-tz %s\n", ci.committer_tz);
1566                write_filename_info(suspect->path);
1567                printf("summary %s\n", ci.summary);
1568                if (suspect->commit->object.flags & UNINTERESTING)
1569                        printf("boundary\n");
1570        }
1571        else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1572                write_filename_info(suspect->path);
1573
1574        cp = nth_line(sb, ent->lno);
1575        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1576                char ch;
1577                if (cnt)
1578                        printf("%s %d %d\n", hex,
1579                               ent->s_lno + 1 + cnt,
1580                               ent->lno + 1 + cnt);
1581                putchar('\t');
1582                do {
1583                        ch = *cp++;
1584                        putchar(ch);
1585                } while (ch != '\n' &&
1586                         cp < sb->final_buf + sb->final_buf_size);
1587        }
1588}
1589
1590static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1591{
1592        int cnt;
1593        const char *cp;
1594        struct origin *suspect = ent->suspect;
1595        struct commit_info ci;
1596        char hex[41];
1597        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1598
1599        get_commit_info(suspect->commit, &ci, 1);
1600        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1601
1602        cp = nth_line(sb, ent->lno);
1603        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1604                char ch;
1605                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1606
1607                if (suspect->commit->object.flags & UNINTERESTING) {
1608                        if (blank_boundary)
1609                                memset(hex, ' ', length);
1610                        else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
1611                                length--;
1612                                putchar('^');
1613                        }
1614                }
1615
1616                printf("%.*s", length, hex);
1617                if (opt & OUTPUT_ANNOTATE_COMPAT)
1618                        printf("\t(%10s\t%10s\t%d)", ci.author,
1619                               format_time(ci.author_time, ci.author_tz,
1620                                           show_raw_time),
1621                               ent->lno + 1 + cnt);
1622                else {
1623                        if (opt & OUTPUT_SHOW_SCORE)
1624                                printf(" %*d %02d",
1625                                       max_score_digits, ent->score,
1626                                       ent->suspect->refcnt);
1627                        if (opt & OUTPUT_SHOW_NAME)
1628                                printf(" %-*.*s", longest_file, longest_file,
1629                                       suspect->path);
1630                        if (opt & OUTPUT_SHOW_NUMBER)
1631                                printf(" %*d", max_orig_digits,
1632                                       ent->s_lno + 1 + cnt);
1633
1634                        if (!(opt & OUTPUT_NO_AUTHOR)) {
1635                                int pad = longest_author - utf8_strwidth(ci.author);
1636                                printf(" (%s%*s %10s",
1637                                       ci.author, pad, "",
1638                                       format_time(ci.author_time,
1639                                                   ci.author_tz,
1640                                                   show_raw_time));
1641                        }
1642                        printf(" %*d) ",
1643                               max_digits, ent->lno + 1 + cnt);
1644                }
1645                do {
1646                        ch = *cp++;
1647                        putchar(ch);
1648                } while (ch != '\n' &&
1649                         cp < sb->final_buf + sb->final_buf_size);
1650        }
1651}
1652
1653static void output(struct scoreboard *sb, int option)
1654{
1655        struct blame_entry *ent;
1656
1657        if (option & OUTPUT_PORCELAIN) {
1658                for (ent = sb->ent; ent; ent = ent->next) {
1659                        struct blame_entry *oth;
1660                        struct origin *suspect = ent->suspect;
1661                        struct commit *commit = suspect->commit;
1662                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1663                                continue;
1664                        for (oth = ent->next; oth; oth = oth->next) {
1665                                if ((oth->suspect->commit != commit) ||
1666                                    !strcmp(oth->suspect->path, suspect->path))
1667                                        continue;
1668                                commit->object.flags |= MORE_THAN_ONE_PATH;
1669                                break;
1670                        }
1671                }
1672        }
1673
1674        for (ent = sb->ent; ent; ent = ent->next) {
1675                if (option & OUTPUT_PORCELAIN)
1676                        emit_porcelain(sb, ent);
1677                else {
1678                        emit_other(sb, ent, option);
1679                }
1680        }
1681}
1682
1683/*
1684 * To allow quick access to the contents of nth line in the
1685 * final image, prepare an index in the scoreboard.
1686 */
1687static int prepare_lines(struct scoreboard *sb)
1688{
1689        const char *buf = sb->final_buf;
1690        unsigned long len = sb->final_buf_size;
1691        int num = 0, incomplete = 0, bol = 1;
1692
1693        if (len && buf[len-1] != '\n')
1694                incomplete++; /* incomplete line at the end */
1695        while (len--) {
1696                if (bol) {
1697                        sb->lineno = xrealloc(sb->lineno,
1698                                              sizeof(int* ) * (num + 1));
1699                        sb->lineno[num] = buf - sb->final_buf;
1700                        bol = 0;
1701                }
1702                if (*buf++ == '\n') {
1703                        num++;
1704                        bol = 1;
1705                }
1706        }
1707        sb->lineno = xrealloc(sb->lineno,
1708                              sizeof(int* ) * (num + incomplete + 1));
1709        sb->lineno[num + incomplete] = buf - sb->final_buf;
1710        sb->num_lines = num + incomplete;
1711        return sb->num_lines;
1712}
1713
1714/*
1715 * Add phony grafts for use with -S; this is primarily to
1716 * support git's cvsserver that wants to give a linear history
1717 * to its clients.
1718 */
1719static int read_ancestry(const char *graft_file)
1720{
1721        FILE *fp = fopen(graft_file, "r");
1722        char buf[1024];
1723        if (!fp)
1724                return -1;
1725        while (fgets(buf, sizeof(buf), fp)) {
1726                /* The format is just "Commit Parent1 Parent2 ...\n" */
1727                int len = strlen(buf);
1728                struct commit_graft *graft = read_graft_line(buf, len);
1729                if (graft)
1730                        register_commit_graft(graft, 0);
1731        }
1732        fclose(fp);
1733        return 0;
1734}
1735
1736/*
1737 * How many columns do we need to show line numbers in decimal?
1738 */
1739static int lineno_width(int lines)
1740{
1741        int i, width;
1742
1743        for (width = 1, i = 10; i <= lines + 1; width++)
1744                i *= 10;
1745        return width;
1746}
1747
1748/*
1749 * How many columns do we need to show line numbers, authors,
1750 * and filenames?
1751 */
1752static void find_alignment(struct scoreboard *sb, int *option)
1753{
1754        int longest_src_lines = 0;
1755        int longest_dst_lines = 0;
1756        unsigned largest_score = 0;
1757        struct blame_entry *e;
1758
1759        for (e = sb->ent; e; e = e->next) {
1760                struct origin *suspect = e->suspect;
1761                struct commit_info ci;
1762                int num;
1763
1764                if (strcmp(suspect->path, sb->path))
1765                        *option |= OUTPUT_SHOW_NAME;
1766                num = strlen(suspect->path);
1767                if (longest_file < num)
1768                        longest_file = num;
1769                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1770                        suspect->commit->object.flags |= METAINFO_SHOWN;
1771                        get_commit_info(suspect->commit, &ci, 1);
1772                        num = utf8_strwidth(ci.author);
1773                        if (longest_author < num)
1774                                longest_author = num;
1775                }
1776                num = e->s_lno + e->num_lines;
1777                if (longest_src_lines < num)
1778                        longest_src_lines = num;
1779                num = e->lno + e->num_lines;
1780                if (longest_dst_lines < num)
1781                        longest_dst_lines = num;
1782                if (largest_score < ent_score(sb, e))
1783                        largest_score = ent_score(sb, e);
1784        }
1785        max_orig_digits = lineno_width(longest_src_lines);
1786        max_digits = lineno_width(longest_dst_lines);
1787        max_score_digits = lineno_width(largest_score);
1788}
1789
1790/*
1791 * For debugging -- origin is refcounted, and this asserts that
1792 * we do not underflow.
1793 */
1794static void sanity_check_refcnt(struct scoreboard *sb)
1795{
1796        int baa = 0;
1797        struct blame_entry *ent;
1798
1799        for (ent = sb->ent; ent; ent = ent->next) {
1800                /* Nobody should have zero or negative refcnt */
1801                if (ent->suspect->refcnt <= 0) {
1802                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1803                                ent->suspect->path,
1804                                sha1_to_hex(ent->suspect->commit->object.sha1),
1805                                ent->suspect->refcnt);
1806                        baa = 1;
1807                }
1808        }
1809        for (ent = sb->ent; ent; ent = ent->next) {
1810                /* Mark the ones that haven't been checked */
1811                if (0 < ent->suspect->refcnt)
1812                        ent->suspect->refcnt = -ent->suspect->refcnt;
1813        }
1814        for (ent = sb->ent; ent; ent = ent->next) {
1815                /*
1816                 * ... then pick each and see if they have the the
1817                 * correct refcnt.
1818                 */
1819                int found;
1820                struct blame_entry *e;
1821                struct origin *suspect = ent->suspect;
1822
1823                if (0 < suspect->refcnt)
1824                        continue;
1825                suspect->refcnt = -suspect->refcnt; /* Unmark */
1826                for (found = 0, e = sb->ent; e; e = e->next) {
1827                        if (e->suspect != suspect)
1828                                continue;
1829                        found++;
1830                }
1831                if (suspect->refcnt != found) {
1832                        fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1833                                ent->suspect->path,
1834                                sha1_to_hex(ent->suspect->commit->object.sha1),
1835                                ent->suspect->refcnt, found);
1836                        baa = 2;
1837                }
1838        }
1839        if (baa) {
1840                int opt = 0160;
1841                find_alignment(sb, &opt);
1842                output(sb, opt);
1843                die("Baa %d!", baa);
1844        }
1845}
1846
1847/*
1848 * Used for the command line parsing; check if the path exists
1849 * in the working tree.
1850 */
1851static int has_string_in_work_tree(const char *path)
1852{
1853        struct stat st;
1854        return !lstat(path, &st);
1855}
1856
1857static unsigned parse_score(const char *arg)
1858{
1859        char *end;
1860        unsigned long score = strtoul(arg, &end, 10);
1861        if (*end)
1862                return 0;
1863        return score;
1864}
1865
1866static const char *add_prefix(const char *prefix, const char *path)
1867{
1868        return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
1869}
1870
1871/*
1872 * Parsing of (comma separated) one item in the -L option
1873 */
1874static const char *parse_loc(const char *spec,
1875                             struct scoreboard *sb, long lno,
1876                             long begin, long *ret)
1877{
1878        char *term;
1879        const char *line;
1880        long num;
1881        int reg_error;
1882        regex_t regexp;
1883        regmatch_t match[1];
1884
1885        /* Allow "-L <something>,+20" to mean starting at <something>
1886         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1887         * <something>.
1888         */
1889        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1890                num = strtol(spec + 1, &term, 10);
1891                if (term != spec + 1) {
1892                        if (spec[0] == '-')
1893                                num = 0 - num;
1894                        if (0 < num)
1895                                *ret = begin + num - 2;
1896                        else if (!num)
1897                                *ret = begin;
1898                        else
1899                                *ret = begin + num;
1900                        return term;
1901                }
1902                return spec;
1903        }
1904        num = strtol(spec, &term, 10);
1905        if (term != spec) {
1906                *ret = num;
1907                return term;
1908        }
1909        if (spec[0] != '/')
1910                return spec;
1911
1912        /* it could be a regexp of form /.../ */
1913        for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1914                if (*term == '\\')
1915                        term++;
1916        }
1917        if (*term != '/')
1918                return spec;
1919
1920        /* try [spec+1 .. term-1] as regexp */
1921        *term = 0;
1922        begin--; /* input is in human terms */
1923        line = nth_line(sb, begin);
1924
1925        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1926            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1927                const char *cp = line + match[0].rm_so;
1928                const char *nline;
1929
1930                while (begin++ < lno) {
1931                        nline = nth_line(sb, begin);
1932                        if (line <= cp && cp < nline)
1933                                break;
1934                        line = nline;
1935                }
1936                *ret = begin;
1937                regfree(&regexp);
1938                *term++ = '/';
1939                return term;
1940        }
1941        else {
1942                char errbuf[1024];
1943                regerror(reg_error, &regexp, errbuf, 1024);
1944                die("-L parameter '%s': %s", spec + 1, errbuf);
1945        }
1946}
1947
1948/*
1949 * Parsing of -L option
1950 */
1951static void prepare_blame_range(struct scoreboard *sb,
1952                                const char *bottomtop,
1953                                long lno,
1954                                long *bottom, long *top)
1955{
1956        const char *term;
1957
1958        term = parse_loc(bottomtop, sb, lno, 1, bottom);
1959        if (*term == ',') {
1960                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1961                if (*term)
1962                        usage(blame_usage);
1963        }
1964        if (*term)
1965                usage(blame_usage);
1966}
1967
1968static int git_blame_config(const char *var, const char *value, void *cb)
1969{
1970        if (!strcmp(var, "blame.showroot")) {
1971                show_root = git_config_bool(var, value);
1972                return 0;
1973        }
1974        if (!strcmp(var, "blame.blankboundary")) {
1975                blank_boundary = git_config_bool(var, value);
1976                return 0;
1977        }
1978        return git_default_config(var, value, cb);
1979}
1980
1981/*
1982 * Prepare a dummy commit that represents the work tree (or staged) item.
1983 * Note that annotating work tree item never works in the reverse.
1984 */
1985static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1986{
1987        struct commit *commit;
1988        struct origin *origin;
1989        unsigned char head_sha1[20];
1990        struct strbuf buf = STRBUF_INIT;
1991        const char *ident;
1992        time_t now;
1993        int size, len;
1994        struct cache_entry *ce;
1995        unsigned mode;
1996
1997        if (get_sha1("HEAD", head_sha1))
1998                die("No such ref: HEAD");
1999
2000        time(&now);
2001        commit = xcalloc(1, sizeof(*commit));
2002        commit->parents = xcalloc(1, sizeof(*commit->parents));
2003        commit->parents->item = lookup_commit_reference(head_sha1);
2004        commit->object.parsed = 1;
2005        commit->date = now;
2006        commit->object.type = OBJ_COMMIT;
2007
2008        origin = make_origin(commit, path);
2009
2010        if (!contents_from || strcmp("-", contents_from)) {
2011                struct stat st;
2012                const char *read_from;
2013
2014                if (contents_from) {
2015                        if (stat(contents_from, &st) < 0)
2016                                die("Cannot stat %s", contents_from);
2017                        read_from = contents_from;
2018                }
2019                else {
2020                        if (lstat(path, &st) < 0)
2021                                die("Cannot lstat %s", path);
2022                        read_from = path;
2023                }
2024                mode = canon_mode(st.st_mode);
2025                switch (st.st_mode & S_IFMT) {
2026                case S_IFREG:
2027                        if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
2028                                die("cannot open or read %s", read_from);
2029                        break;
2030                case S_IFLNK:
2031                        if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
2032                                die("cannot readlink %s", read_from);
2033                        break;
2034                default:
2035                        die("unsupported file type %s", read_from);
2036                }
2037        }
2038        else {
2039                /* Reading from stdin */
2040                contents_from = "standard input";
2041                mode = 0;
2042                if (strbuf_read(&buf, 0, 0) < 0)
2043                        die("read error %s from stdin", strerror(errno));
2044        }
2045        convert_to_git(path, buf.buf, buf.len, &buf, 0);
2046        origin->file.ptr = buf.buf;
2047        origin->file.size = buf.len;
2048        pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
2049        commit->util = origin;
2050
2051        /*
2052         * Read the current index, replace the path entry with
2053         * origin->blob_sha1 without mucking with its mode or type
2054         * bits; we are not going to write this index out -- we just
2055         * want to run "diff-index --cached".
2056         */
2057        discard_cache();
2058        read_cache();
2059
2060        len = strlen(path);
2061        if (!mode) {
2062                int pos = cache_name_pos(path, len);
2063                if (0 <= pos)
2064                        mode = active_cache[pos]->ce_mode;
2065                else
2066                        /* Let's not bother reading from HEAD tree */
2067                        mode = S_IFREG | 0644;
2068        }
2069        size = cache_entry_size(len);
2070        ce = xcalloc(1, size);
2071        hashcpy(ce->sha1, origin->blob_sha1);
2072        memcpy(ce->name, path, len);
2073        ce->ce_flags = create_ce_flags(len, 0);
2074        ce->ce_mode = create_ce_mode(mode);
2075        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2076
2077        /*
2078         * We are not going to write this out, so this does not matter
2079         * right now, but someday we might optimize diff-index --cached
2080         * with cache-tree information.
2081         */
2082        cache_tree_invalidate_path(active_cache_tree, path);
2083
2084        commit->buffer = xmalloc(400);
2085        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2086        snprintf(commit->buffer, 400,
2087                "tree 0000000000000000000000000000000000000000\n"
2088                "parent %s\n"
2089                "author %s\n"
2090                "committer %s\n\n"
2091                "Version of %s from %s\n",
2092                sha1_to_hex(head_sha1),
2093                ident, ident, path, contents_from ? contents_from : path);
2094        return commit;
2095}
2096
2097static const char *prepare_final(struct scoreboard *sb)
2098{
2099        int i;
2100        const char *final_commit_name = NULL;
2101        struct rev_info *revs = sb->revs;
2102
2103        /*
2104         * There must be one and only one positive commit in the
2105         * revs->pending array.
2106         */
2107        for (i = 0; i < revs->pending.nr; i++) {
2108                struct object *obj = revs->pending.objects[i].item;
2109                if (obj->flags & UNINTERESTING)
2110                        continue;
2111                while (obj->type == OBJ_TAG)
2112                        obj = deref_tag(obj, NULL, 0);
2113                if (obj->type != OBJ_COMMIT)
2114                        die("Non commit %s?", revs->pending.objects[i].name);
2115                if (sb->final)
2116                        die("More than one commit to dig from %s and %s?",
2117                            revs->pending.objects[i].name,
2118                            final_commit_name);
2119                sb->final = (struct commit *) obj;
2120                final_commit_name = revs->pending.objects[i].name;
2121        }
2122        return final_commit_name;
2123}
2124
2125static const char *prepare_initial(struct scoreboard *sb)
2126{
2127        int i;
2128        const char *final_commit_name = NULL;
2129        struct rev_info *revs = sb->revs;
2130
2131        /*
2132         * There must be one and only one negative commit, and it must be
2133         * the boundary.
2134         */
2135        for (i = 0; i < revs->pending.nr; i++) {
2136                struct object *obj = revs->pending.objects[i].item;
2137                if (!(obj->flags & UNINTERESTING))
2138                        continue;
2139                while (obj->type == OBJ_TAG)
2140                        obj = deref_tag(obj, NULL, 0);
2141                if (obj->type != OBJ_COMMIT)
2142                        die("Non commit %s?", revs->pending.objects[i].name);
2143                if (sb->final)
2144                        die("More than one commit to dig down to %s and %s?",
2145                            revs->pending.objects[i].name,
2146                            final_commit_name);
2147                sb->final = (struct commit *) obj;
2148                final_commit_name = revs->pending.objects[i].name;
2149        }
2150        if (!final_commit_name)
2151                die("No commit to dig down to?");
2152        return final_commit_name;
2153}
2154
2155static int blame_copy_callback(const struct option *option, const char *arg, int unset)
2156{
2157        int *opt = option->value;
2158
2159        /*
2160         * -C enables copy from removed files;
2161         * -C -C enables copy from existing files, but only
2162         *       when blaming a new file;
2163         * -C -C -C enables copy from existing files for
2164         *          everybody
2165         */
2166        if (*opt & PICKAXE_BLAME_COPY_HARDER)
2167                *opt |= PICKAXE_BLAME_COPY_HARDEST;
2168        if (*opt & PICKAXE_BLAME_COPY)
2169                *opt |= PICKAXE_BLAME_COPY_HARDER;
2170        *opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2171
2172        if (arg)
2173                blame_copy_score = parse_score(arg);
2174        return 0;
2175}
2176
2177static int blame_move_callback(const struct option *option, const char *arg, int unset)
2178{
2179        int *opt = option->value;
2180
2181        *opt |= PICKAXE_BLAME_MOVE;
2182
2183        if (arg)
2184                blame_move_score = parse_score(arg);
2185        return 0;
2186}
2187
2188static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset)
2189{
2190        const char **bottomtop = option->value;
2191        if (!arg)
2192                return -1;
2193        if (*bottomtop)
2194                die("More than one '-L n,m' option given");
2195        *bottomtop = arg;
2196        return 0;
2197}
2198
2199int cmd_blame(int argc, const char **argv, const char *prefix)
2200{
2201        struct rev_info revs;
2202        const char *path;
2203        struct scoreboard sb;
2204        struct origin *o;
2205        struct blame_entry *ent;
2206        long dashdash_pos, bottom, top, lno;
2207        const char *final_commit_name = NULL;
2208        enum object_type type;
2209
2210        static const char *bottomtop = NULL;
2211        static int output_option = 0, opt = 0;
2212        static int show_stats = 0;
2213        static const char *revs_file = NULL;
2214        static const char *contents_from = NULL;
2215        static const struct option options[] = {
2216                OPT_BOOLEAN(0, "incremental", &incremental, "Show blame entries as we find them, incrementally"),
2217                OPT_BOOLEAN('b', NULL, &blank_boundary, "Show blank SHA-1 for boundary commits (Default: off)"),
2218                OPT_BOOLEAN(0, "root", &show_root, "Do not treat root commits as boundaries (Default: off)"),
2219                OPT_BOOLEAN(0, "show-stats", &show_stats, "Show work cost statistics"),
2220                OPT_BIT(0, "score-debug", &output_option, "Show output score for blame entries", OUTPUT_SHOW_SCORE),
2221                OPT_BIT('f', "show-name", &output_option, "Show original filename (Default: auto)", OUTPUT_SHOW_NAME),
2222                OPT_BIT('n', "show-number", &output_option, "Show original linenumber (Default: off)", OUTPUT_SHOW_NUMBER),
2223                OPT_BIT('p', "porcelain", &output_option, "Show in a format designed for machine consumption", OUTPUT_PORCELAIN),
2224                OPT_BIT('c', NULL, &output_option, "Use the same output mode as git-annotate (Default: off)", OUTPUT_ANNOTATE_COMPAT),
2225                OPT_BIT('t', NULL, &output_option, "Show raw timestamp (Default: off)", OUTPUT_RAW_TIMESTAMP),
2226                OPT_BIT('l', NULL, &output_option, "Show long commit SHA1 (Default: off)", OUTPUT_LONG_OBJECT_NAME),
2227                OPT_BIT('s', NULL, &output_option, "Suppress author name and timestamp (Default: off)", OUTPUT_NO_AUTHOR),
2228                OPT_BIT('w', NULL, &xdl_opts, "Ignore whitespace differences", XDF_IGNORE_WHITESPACE),
2229                OPT_STRING('S', NULL, &revs_file, "file", "Use revisions from <file> instead of calling git-rev-list"),
2230                OPT_STRING(0, "contents", &contents_from, "file", "Use <file>'s contents as the final image"),
2231                { OPTION_CALLBACK, 'C', NULL, &opt, "score", "Find line copies within and across files", PARSE_OPT_OPTARG, blame_copy_callback },
2232                { OPTION_CALLBACK, 'M', NULL, &opt, "score", "Find line movements within and across files", PARSE_OPT_OPTARG, blame_move_callback },
2233                OPT_CALLBACK('L', NULL, &bottomtop, "n,m", "Process only line range n,m, counting from 1", blame_bottomtop_callback),
2234                OPT_END()
2235        };
2236
2237        struct parse_opt_ctx_t ctx;
2238        int cmd_is_annotate = !strcmp(argv[0], "annotate");
2239
2240        git_config(git_blame_config, NULL);
2241        init_revisions(&revs, NULL);
2242        save_commit_buffer = 0;
2243        dashdash_pos = 0;
2244
2245        parse_options_start(&ctx, argc, argv, PARSE_OPT_KEEP_DASHDASH |
2246                            PARSE_OPT_KEEP_ARGV0);
2247        for (;;) {
2248                switch (parse_options_step(&ctx, options, blame_opt_usage)) {
2249                case PARSE_OPT_HELP:
2250                        exit(129);
2251                case PARSE_OPT_DONE:
2252                        if (ctx.argv[0])
2253                                dashdash_pos = ctx.cpidx;
2254                        goto parse_done;
2255                }
2256
2257                if (!strcmp(ctx.argv[0], "--reverse")) {
2258                        ctx.argv[0] = "--children";
2259                        reverse = 1;
2260                }
2261                parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
2262        }
2263parse_done:
2264        argc = parse_options_end(&ctx);
2265
2266        if (revs_file && read_ancestry(revs_file))
2267                die("reading graft file %s failed: %s",
2268                    revs_file, strerror(errno));
2269
2270        if (cmd_is_annotate)
2271                output_option |= OUTPUT_ANNOTATE_COMPAT;
2272
2273        if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
2274                opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
2275                        PICKAXE_BLAME_COPY_HARDER);
2276
2277        if (!blame_move_score)
2278                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2279        if (!blame_copy_score)
2280                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2281
2282        /*
2283         * We have collected options unknown to us in argv[1..unk]
2284         * which are to be passed to revision machinery if we are
2285         * going to do the "bottom" processing.
2286         *
2287         * The remaining are:
2288         *
2289         * (1) if dashdash_pos != 0, its either
2290         *     "blame [revisions] -- <path>" or
2291         *     "blame -- <path> <rev>"
2292         *
2293         * (2) otherwise, its one of the two:
2294         *     "blame [revisions] <path>"
2295         *     "blame <path> <rev>"
2296         *
2297         * Note that we must strip out <path> from the arguments: we do not
2298         * want the path pruning but we may want "bottom" processing.
2299         */
2300        if (dashdash_pos) {
2301                switch (argc - dashdash_pos - 1) {
2302                case 2: /* (1b) */
2303                        if (argc != 4)
2304                                usage_with_options(blame_opt_usage, options);
2305                        /* reorder for the new way: <rev> -- <path> */
2306                        argv[1] = argv[3];
2307                        argv[3] = argv[2];
2308                        argv[2] = "--";
2309                        /* FALLTHROUGH */
2310                case 1: /* (1a) */
2311                        path = add_prefix(prefix, argv[--argc]);
2312                        argv[argc] = NULL;
2313                        break;
2314                default:
2315                        usage_with_options(blame_opt_usage, options);
2316                }
2317        } else {
2318                if (argc < 2)
2319                        usage_with_options(blame_opt_usage, options);
2320                path = add_prefix(prefix, argv[argc - 1]);
2321                if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
2322                        path = add_prefix(prefix, argv[1]);
2323                        argv[1] = argv[2];
2324                }
2325                argv[argc - 1] = "--";
2326
2327                setup_work_tree();
2328                if (!has_string_in_work_tree(path))
2329                        die("cannot stat path %s: %s", path, strerror(errno));
2330        }
2331
2332        setup_revisions(argc, argv, &revs, NULL);
2333        memset(&sb, 0, sizeof(sb));
2334
2335        sb.revs = &revs;
2336        if (!reverse)
2337                final_commit_name = prepare_final(&sb);
2338        else if (contents_from)
2339                die("--contents and --children do not blend well.");
2340        else
2341                final_commit_name = prepare_initial(&sb);
2342
2343        if (!sb.final) {
2344                /*
2345                 * "--not A B -- path" without anything positive;
2346                 * do not default to HEAD, but use the working tree
2347                 * or "--contents".
2348                 */
2349                setup_work_tree();
2350                sb.final = fake_working_tree_commit(path, contents_from);
2351                add_pending_object(&revs, &(sb.final->object), ":");
2352        }
2353        else if (contents_from)
2354                die("Cannot use --contents with final commit object name");
2355
2356        /*
2357         * If we have bottom, this will mark the ancestors of the
2358         * bottom commits we would reach while traversing as
2359         * uninteresting.
2360         */
2361        if (prepare_revision_walk(&revs))
2362                die("revision walk setup failed");
2363
2364        if (is_null_sha1(sb.final->object.sha1)) {
2365                char *buf;
2366                o = sb.final->util;
2367                buf = xmalloc(o->file.size + 1);
2368                memcpy(buf, o->file.ptr, o->file.size + 1);
2369                sb.final_buf = buf;
2370                sb.final_buf_size = o->file.size;
2371        }
2372        else {
2373                o = get_origin(&sb, sb.final, path);
2374                if (fill_blob_sha1(o))
2375                        die("no such path %s in %s", path, final_commit_name);
2376
2377                sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2378                                              &sb.final_buf_size);
2379                if (!sb.final_buf)
2380                        die("Cannot read blob %s for path %s",
2381                            sha1_to_hex(o->blob_sha1),
2382                            path);
2383        }
2384        num_read_blob++;
2385        lno = prepare_lines(&sb);
2386
2387        bottom = top = 0;
2388        if (bottomtop)
2389                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2390        if (bottom && top && top < bottom) {
2391                long tmp;
2392                tmp = top; top = bottom; bottom = tmp;
2393        }
2394        if (bottom < 1)
2395                bottom = 1;
2396        if (top < 1)
2397                top = lno;
2398        bottom--;
2399        if (lno < top)
2400                die("file %s has only %lu lines", path, lno);
2401
2402        ent = xcalloc(1, sizeof(*ent));
2403        ent->lno = bottom;
2404        ent->num_lines = top - bottom;
2405        ent->suspect = o;
2406        ent->s_lno = bottom;
2407
2408        sb.ent = ent;
2409        sb.path = path;
2410
2411        read_mailmap(&mailmap, NULL);
2412
2413        if (!incremental)
2414                setup_pager();
2415
2416        assign_blame(&sb, opt);
2417
2418        if (incremental)
2419                return 0;
2420
2421        coalesce(&sb);
2422
2423        if (!(output_option & OUTPUT_PORCELAIN))
2424                find_alignment(&sb, &output_option);
2425
2426        output(&sb, output_option);
2427        free((void *)sb.final_buf);
2428        for (ent = sb.ent; ent; ) {
2429                struct blame_entry *e = ent->next;
2430                free(ent);
2431                ent = e;
2432        }
2433
2434        if (show_stats) {
2435                printf("num read blob: %d\n", num_read_blob);
2436                printf("num get patch: %d\n", num_get_patch);
2437                printf("num commits: %d\n", num_commits);
2438        }
2439        return 0;
2440}