builtin-blame.con commit filter-branch: a few more touch ups to the man page (73616fd)
   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 "path-list.h"
  20#include "mailmap.h"
  21
  22static char blame_usage[] =
  23"git-blame [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-p] [-w] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [--contents <filename>] [--incremental] [commit] [--] file\n"
  24"  -c                  Use the same output mode as git-annotate (Default: off)\n"
  25"  -b                  Show blank SHA-1 for boundary commits (Default: off)\n"
  26"  -l                  Show long commit SHA1 (Default: off)\n"
  27"  --root              Do not treat root commits as boundaries (Default: off)\n"
  28"  -t                  Show raw timestamp (Default: off)\n"
  29"  -f, --show-name     Show original filename (Default: auto)\n"
  30"  -n, --show-number   Show original linenumber (Default: off)\n"
  31"  -s                  Suppress author name and timestamp (Default: off)\n"
  32"  -p, --porcelain     Show in a format designed for machine consumption\n"
  33"  -w                  Ignore whitespace differences\n"
  34"  -L n,m              Process only line range n,m, counting from 1\n"
  35"  -M, -C              Find line movements within and across files\n"
  36"  --incremental       Show blame entries as we find them, incrementally\n"
  37"  --contents file     Use <file>'s contents as the final image\n"
  38"  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
  39
  40static int longest_file;
  41static int longest_author;
  42static int max_orig_digits;
  43static int max_digits;
  44static int max_score_digits;
  45static int show_root;
  46static int blank_boundary;
  47static int incremental;
  48static int cmd_is_annotate;
  49static int xdl_opts = XDF_NEED_MINIMAL;
  50static struct path_list mailmap;
  51
  52#ifndef DEBUG
  53#define DEBUG 0
  54#endif
  55
  56/* stats */
  57static int num_read_blob;
  58static int num_get_patch;
  59static int num_commits;
  60
  61#define PICKAXE_BLAME_MOVE              01
  62#define PICKAXE_BLAME_COPY              02
  63#define PICKAXE_BLAME_COPY_HARDER       04
  64#define PICKAXE_BLAME_COPY_HARDEST      010
  65
  66/*
  67 * blame for a blame_entry with score lower than these thresholds
  68 * is not passed to the parent using move/copy logic.
  69 */
  70static unsigned blame_move_score;
  71static unsigned blame_copy_score;
  72#define BLAME_DEFAULT_MOVE_SCORE        20
  73#define BLAME_DEFAULT_COPY_SCORE        40
  74
  75/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  76#define METAINFO_SHOWN          (1u<<12)
  77#define MORE_THAN_ONE_PATH      (1u<<13)
  78
  79/*
  80 * One blob in a commit that is being suspected
  81 */
  82struct origin {
  83        int refcnt;
  84        struct commit *commit;
  85        mmfile_t file;
  86        unsigned char blob_sha1[20];
  87        char path[FLEX_ARRAY];
  88};
  89
  90/*
  91 * Given an origin, prepare mmfile_t structure to be used by the
  92 * diff machinery
  93 */
  94static char *fill_origin_blob(struct origin *o, mmfile_t *file)
  95{
  96        if (!o->file.ptr) {
  97                enum object_type type;
  98                num_read_blob++;
  99                file->ptr = read_sha1_file(o->blob_sha1, &type,
 100                                           (unsigned long *)(&(file->size)));
 101                o->file = *file;
 102        }
 103        else
 104                *file = o->file;
 105        return file->ptr;
 106}
 107
 108/*
 109 * Origin is refcounted and usually we keep the blob contents to be
 110 * reused.
 111 */
 112static inline struct origin *origin_incref(struct origin *o)
 113{
 114        if (o)
 115                o->refcnt++;
 116        return o;
 117}
 118
 119static void origin_decref(struct origin *o)
 120{
 121        if (o && --o->refcnt <= 0) {
 122                if (o->file.ptr)
 123                        free(o->file.ptr);
 124                memset(o, 0, sizeof(*o));
 125                free(o);
 126        }
 127}
 128
 129/*
 130 * Each group of lines is described by a blame_entry; it can be split
 131 * as we pass blame to the parents.  They form a linked list in the
 132 * scoreboard structure, sorted by the target line number.
 133 */
 134struct blame_entry {
 135        struct blame_entry *prev;
 136        struct blame_entry *next;
 137
 138        /* the first line of this group in the final image;
 139         * internally all line numbers are 0 based.
 140         */
 141        int lno;
 142
 143        /* how many lines this group has */
 144        int num_lines;
 145
 146        /* the commit that introduced this group into the final image */
 147        struct origin *suspect;
 148
 149        /* true if the suspect is truly guilty; false while we have not
 150         * checked if the group came from one of its parents.
 151         */
 152        char guilty;
 153
 154        /* the line number of the first line of this group in the
 155         * suspect's file; internally all line numbers are 0 based.
 156         */
 157        int s_lno;
 158
 159        /* how significant this entry is -- cached to avoid
 160         * scanning the lines over and over.
 161         */
 162        unsigned score;
 163};
 164
 165/*
 166 * The current state of the blame assignment.
 167 */
 168struct scoreboard {
 169        /* the final commit (i.e. where we started digging from) */
 170        struct commit *final;
 171
 172        const char *path;
 173
 174        /*
 175         * The contents in the final image.
 176         * Used by many functions to obtain contents of the nth line,
 177         * indexed with scoreboard.lineno[blame_entry.lno].
 178         */
 179        const char *final_buf;
 180        unsigned long final_buf_size;
 181
 182        /* linked list of blames */
 183        struct blame_entry *ent;
 184
 185        /* look-up a line in the final buffer */
 186        int num_lines;
 187        int *lineno;
 188};
 189
 190static inline int same_suspect(struct origin *a, struct origin *b)
 191{
 192        if (a == b)
 193                return 1;
 194        if (a->commit != b->commit)
 195                return 0;
 196        return !strcmp(a->path, b->path);
 197}
 198
 199static void sanity_check_refcnt(struct scoreboard *);
 200
 201/*
 202 * If two blame entries that are next to each other came from
 203 * contiguous lines in the same origin (i.e. <commit, path> pair),
 204 * merge them together.
 205 */
 206static void coalesce(struct scoreboard *sb)
 207{
 208        struct blame_entry *ent, *next;
 209
 210        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 211                if (same_suspect(ent->suspect, next->suspect) &&
 212                    ent->guilty == next->guilty &&
 213                    ent->s_lno + ent->num_lines == next->s_lno) {
 214                        ent->num_lines += next->num_lines;
 215                        ent->next = next->next;
 216                        if (ent->next)
 217                                ent->next->prev = ent;
 218                        origin_decref(next->suspect);
 219                        free(next);
 220                        ent->score = 0;
 221                        next = ent; /* again */
 222                }
 223        }
 224
 225        if (DEBUG) /* sanity */
 226                sanity_check_refcnt(sb);
 227}
 228
 229/*
 230 * Given a commit and a path in it, create a new origin structure.
 231 * The callers that add blame to the scoreboard should use
 232 * get_origin() to obtain shared, refcounted copy instead of calling
 233 * this function directly.
 234 */
 235static struct origin *make_origin(struct commit *commit, const char *path)
 236{
 237        struct origin *o;
 238        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 239        o->commit = commit;
 240        o->refcnt = 1;
 241        strcpy(o->path, path);
 242        return o;
 243}
 244
 245/*
 246 * Locate an existing origin or create a new one.
 247 */
 248static struct origin *get_origin(struct scoreboard *sb,
 249                                 struct commit *commit,
 250                                 const char *path)
 251{
 252        struct blame_entry *e;
 253
 254        for (e = sb->ent; e; e = e->next) {
 255                if (e->suspect->commit == commit &&
 256                    !strcmp(e->suspect->path, path))
 257                        return origin_incref(e->suspect);
 258        }
 259        return make_origin(commit, path);
 260}
 261
 262/*
 263 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 264 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 265 * for an origin is also used to pass the blame for the entire file to
 266 * the parent to detect the case where a child's blob is identical to
 267 * that of its parent's.
 268 */
 269static int fill_blob_sha1(struct origin *origin)
 270{
 271        unsigned mode;
 272
 273        if (!is_null_sha1(origin->blob_sha1))
 274                return 0;
 275        if (get_tree_entry(origin->commit->object.sha1,
 276                           origin->path,
 277                           origin->blob_sha1, &mode))
 278                goto error_out;
 279        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 280                goto error_out;
 281        return 0;
 282 error_out:
 283        hashclr(origin->blob_sha1);
 284        return -1;
 285}
 286
 287/*
 288 * We have an origin -- check if the same path exists in the
 289 * parent and return an origin structure to represent it.
 290 */
 291static struct origin *find_origin(struct scoreboard *sb,
 292                                  struct commit *parent,
 293                                  struct origin *origin)
 294{
 295        struct origin *porigin = NULL;
 296        struct diff_options diff_opts;
 297        const char *paths[2];
 298
 299        if (parent->util) {
 300                /*
 301                 * Each commit object can cache one origin in that
 302                 * commit.  This is a freestanding copy of origin and
 303                 * not refcounted.
 304                 */
 305                struct origin *cached = parent->util;
 306                if (!strcmp(cached->path, origin->path)) {
 307                        /*
 308                         * The same path between origin and its parent
 309                         * without renaming -- the most common case.
 310                         */
 311                        porigin = get_origin(sb, parent, cached->path);
 312
 313                        /*
 314                         * If the origin was newly created (i.e. get_origin
 315                         * would call make_origin if none is found in the
 316                         * scoreboard), it does not know the blob_sha1,
 317                         * so copy it.  Otherwise porigin was in the
 318                         * scoreboard and already knows blob_sha1.
 319                         */
 320                        if (porigin->refcnt == 1)
 321                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 322                        return porigin;
 323                }
 324                /* otherwise it was not very useful; free it */
 325                free(parent->util);
 326                parent->util = NULL;
 327        }
 328
 329        /* See if the origin->path is different between parent
 330         * and origin first.  Most of the time they are the
 331         * same and diff-tree is fairly efficient about this.
 332         */
 333        diff_setup(&diff_opts);
 334        diff_opts.recursive = 1;
 335        diff_opts.detect_rename = 0;
 336        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 337        paths[0] = origin->path;
 338        paths[1] = NULL;
 339
 340        diff_tree_setup_paths(paths, &diff_opts);
 341        if (diff_setup_done(&diff_opts) < 0)
 342                die("diff-setup");
 343
 344        if (is_null_sha1(origin->commit->object.sha1))
 345                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 346        else
 347                diff_tree_sha1(parent->tree->object.sha1,
 348                               origin->commit->tree->object.sha1,
 349                               "", &diff_opts);
 350        diffcore_std(&diff_opts);
 351
 352        /* It is either one entry that says "modified", or "created",
 353         * or nothing.
 354         */
 355        if (!diff_queued_diff.nr) {
 356                /* The path is the same as parent */
 357                porigin = get_origin(sb, parent, origin->path);
 358                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 359        }
 360        else if (diff_queued_diff.nr != 1)
 361                die("internal error in blame::find_origin");
 362        else {
 363                struct diff_filepair *p = diff_queued_diff.queue[0];
 364                switch (p->status) {
 365                default:
 366                        die("internal error in blame::find_origin (%c)",
 367                            p->status);
 368                case 'M':
 369                        porigin = get_origin(sb, parent, origin->path);
 370                        hashcpy(porigin->blob_sha1, p->one->sha1);
 371                        break;
 372                case 'A':
 373                case 'T':
 374                        /* Did not exist in parent, or type changed */
 375                        break;
 376                }
 377        }
 378        diff_flush(&diff_opts);
 379        if (porigin) {
 380                /*
 381                 * Create a freestanding copy that is not part of
 382                 * the refcounted origin found in the scoreboard, and
 383                 * cache it in the commit.
 384                 */
 385                struct origin *cached;
 386
 387                cached = make_origin(porigin->commit, porigin->path);
 388                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 389                parent->util = cached;
 390        }
 391        return porigin;
 392}
 393
 394/*
 395 * We have an origin -- find the path that corresponds to it in its
 396 * parent and return an origin structure to represent it.
 397 */
 398static struct origin *find_rename(struct scoreboard *sb,
 399                                  struct commit *parent,
 400                                  struct origin *origin)
 401{
 402        struct origin *porigin = NULL;
 403        struct diff_options diff_opts;
 404        int i;
 405        const char *paths[2];
 406
 407        diff_setup(&diff_opts);
 408        diff_opts.recursive = 1;
 409        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 410        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 411        diff_opts.single_follow = origin->path;
 412        paths[0] = NULL;
 413        diff_tree_setup_paths(paths, &diff_opts);
 414        if (diff_setup_done(&diff_opts) < 0)
 415                die("diff-setup");
 416
 417        if (is_null_sha1(origin->commit->object.sha1))
 418                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 419        else
 420                diff_tree_sha1(parent->tree->object.sha1,
 421                               origin->commit->tree->object.sha1,
 422                               "", &diff_opts);
 423        diffcore_std(&diff_opts);
 424
 425        for (i = 0; i < diff_queued_diff.nr; i++) {
 426                struct diff_filepair *p = diff_queued_diff.queue[i];
 427                if ((p->status == 'R' || p->status == 'C') &&
 428                    !strcmp(p->two->path, origin->path)) {
 429                        porigin = get_origin(sb, parent, p->one->path);
 430                        hashcpy(porigin->blob_sha1, p->one->sha1);
 431                        break;
 432                }
 433        }
 434        diff_flush(&diff_opts);
 435        return porigin;
 436}
 437
 438/*
 439 * Parsing of patch chunks...
 440 */
 441struct chunk {
 442        /* line number in postimage; up to but not including this
 443         * line is the same as preimage
 444         */
 445        int same;
 446
 447        /* preimage line number after this chunk */
 448        int p_next;
 449
 450        /* postimage line number after this chunk */
 451        int t_next;
 452};
 453
 454struct patch {
 455        struct chunk *chunks;
 456        int num;
 457};
 458
 459struct blame_diff_state {
 460        struct xdiff_emit_state xm;
 461        struct patch *ret;
 462        unsigned hunk_post_context;
 463        unsigned hunk_in_pre_context : 1;
 464};
 465
 466static void process_u_diff(void *state_, char *line, unsigned long len)
 467{
 468        struct blame_diff_state *state = state_;
 469        struct chunk *chunk;
 470        int off1, off2, len1, len2, num;
 471
 472        num = state->ret->num;
 473        if (len < 4 || line[0] != '@' || line[1] != '@') {
 474                if (state->hunk_in_pre_context && line[0] == ' ')
 475                        state->ret->chunks[num - 1].same++;
 476                else {
 477                        state->hunk_in_pre_context = 0;
 478                        if (line[0] == ' ')
 479                                state->hunk_post_context++;
 480                        else
 481                                state->hunk_post_context = 0;
 482                }
 483                return;
 484        }
 485
 486        if (num && state->hunk_post_context) {
 487                chunk = &state->ret->chunks[num - 1];
 488                chunk->p_next -= state->hunk_post_context;
 489                chunk->t_next -= state->hunk_post_context;
 490        }
 491        state->ret->num = ++num;
 492        state->ret->chunks = xrealloc(state->ret->chunks,
 493                                      sizeof(struct chunk) * num);
 494        chunk = &state->ret->chunks[num - 1];
 495        if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
 496                state->ret->num--;
 497                return;
 498        }
 499
 500        /* Line numbers in patch output are one based. */
 501        off1--;
 502        off2--;
 503
 504        chunk->same = len2 ? off2 : (off2 + 1);
 505
 506        chunk->p_next = off1 + (len1 ? len1 : 1);
 507        chunk->t_next = chunk->same + len2;
 508        state->hunk_in_pre_context = 1;
 509        state->hunk_post_context = 0;
 510}
 511
 512static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
 513                                    int context)
 514{
 515        struct blame_diff_state state;
 516        xpparam_t xpp;
 517        xdemitconf_t xecfg;
 518        xdemitcb_t ecb;
 519
 520        xpp.flags = xdl_opts;
 521        xecfg.ctxlen = context;
 522        xecfg.flags = 0;
 523        ecb.outf = xdiff_outf;
 524        ecb.priv = &state;
 525        memset(&state, 0, sizeof(state));
 526        state.xm.consume = process_u_diff;
 527        state.ret = xmalloc(sizeof(struct patch));
 528        state.ret->chunks = NULL;
 529        state.ret->num = 0;
 530
 531        xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
 532
 533        if (state.ret->num) {
 534                struct chunk *chunk;
 535                chunk = &state.ret->chunks[state.ret->num - 1];
 536                chunk->p_next -= state.hunk_post_context;
 537                chunk->t_next -= state.hunk_post_context;
 538        }
 539        return state.ret;
 540}
 541
 542/*
 543 * Run diff between two origins and grab the patch output, so that
 544 * we can pass blame for lines origin is currently suspected for
 545 * to its parent.
 546 */
 547static struct patch *get_patch(struct origin *parent, struct origin *origin)
 548{
 549        mmfile_t file_p, file_o;
 550        struct patch *patch;
 551
 552        fill_origin_blob(parent, &file_p);
 553        fill_origin_blob(origin, &file_o);
 554        if (!file_p.ptr || !file_o.ptr)
 555                return NULL;
 556        patch = compare_buffer(&file_p, &file_o, 0);
 557        num_get_patch++;
 558        return patch;
 559}
 560
 561static void free_patch(struct patch *p)
 562{
 563        free(p->chunks);
 564        free(p);
 565}
 566
 567/*
 568 * Link in a new blame entry to the scoreboard.  Entries that cover the
 569 * same line range have been removed from the scoreboard previously.
 570 */
 571static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 572{
 573        struct blame_entry *ent, *prev = NULL;
 574
 575        origin_incref(e->suspect);
 576
 577        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 578                prev = ent;
 579
 580        /* prev, if not NULL, is the last one that is below e */
 581        e->prev = prev;
 582        if (prev) {
 583                e->next = prev->next;
 584                prev->next = e;
 585        }
 586        else {
 587                e->next = sb->ent;
 588                sb->ent = e;
 589        }
 590        if (e->next)
 591                e->next->prev = e;
 592}
 593
 594/*
 595 * src typically is on-stack; we want to copy the information in it to
 596 * an malloced blame_entry that is already on the linked list of the
 597 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 598 * gains one.
 599 */
 600static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 601{
 602        struct blame_entry *p, *n;
 603
 604        p = dst->prev;
 605        n = dst->next;
 606        origin_incref(src->suspect);
 607        origin_decref(dst->suspect);
 608        memcpy(dst, src, sizeof(*src));
 609        dst->prev = p;
 610        dst->next = n;
 611        dst->score = 0;
 612}
 613
 614static const char *nth_line(struct scoreboard *sb, int lno)
 615{
 616        return sb->final_buf + sb->lineno[lno];
 617}
 618
 619/*
 620 * It is known that lines between tlno to same came from parent, and e
 621 * has an overlap with that range.  it also is known that parent's
 622 * line plno corresponds to e's line tlno.
 623 *
 624 *                <---- e ----->
 625 *                   <------>
 626 *                   <------------>
 627 *             <------------>
 628 *             <------------------>
 629 *
 630 * Split e into potentially three parts; before this chunk, the chunk
 631 * to be blamed for the parent, and after that portion.
 632 */
 633static void split_overlap(struct blame_entry *split,
 634                          struct blame_entry *e,
 635                          int tlno, int plno, int same,
 636                          struct origin *parent)
 637{
 638        int chunk_end_lno;
 639        memset(split, 0, sizeof(struct blame_entry [3]));
 640
 641        if (e->s_lno < tlno) {
 642                /* there is a pre-chunk part not blamed on parent */
 643                split[0].suspect = origin_incref(e->suspect);
 644                split[0].lno = e->lno;
 645                split[0].s_lno = e->s_lno;
 646                split[0].num_lines = tlno - e->s_lno;
 647                split[1].lno = e->lno + tlno - e->s_lno;
 648                split[1].s_lno = plno;
 649        }
 650        else {
 651                split[1].lno = e->lno;
 652                split[1].s_lno = plno + (e->s_lno - tlno);
 653        }
 654
 655        if (same < e->s_lno + e->num_lines) {
 656                /* there is a post-chunk part not blamed on parent */
 657                split[2].suspect = origin_incref(e->suspect);
 658                split[2].lno = e->lno + (same - e->s_lno);
 659                split[2].s_lno = e->s_lno + (same - e->s_lno);
 660                split[2].num_lines = e->s_lno + e->num_lines - same;
 661                chunk_end_lno = split[2].lno;
 662        }
 663        else
 664                chunk_end_lno = e->lno + e->num_lines;
 665        split[1].num_lines = chunk_end_lno - split[1].lno;
 666
 667        /*
 668         * if it turns out there is nothing to blame the parent for,
 669         * forget about the splitting.  !split[1].suspect signals this.
 670         */
 671        if (split[1].num_lines < 1)
 672                return;
 673        split[1].suspect = origin_incref(parent);
 674}
 675
 676/*
 677 * split_overlap() divided an existing blame e into up to three parts
 678 * in split.  Adjust the linked list of blames in the scoreboard to
 679 * reflect the split.
 680 */
 681static void split_blame(struct scoreboard *sb,
 682                        struct blame_entry *split,
 683                        struct blame_entry *e)
 684{
 685        struct blame_entry *new_entry;
 686
 687        if (split[0].suspect && split[2].suspect) {
 688                /* The first part (reuse storage for the existing entry e) */
 689                dup_entry(e, &split[0]);
 690
 691                /* The last part -- me */
 692                new_entry = xmalloc(sizeof(*new_entry));
 693                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 694                add_blame_entry(sb, new_entry);
 695
 696                /* ... and the middle part -- parent */
 697                new_entry = xmalloc(sizeof(*new_entry));
 698                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 699                add_blame_entry(sb, new_entry);
 700        }
 701        else if (!split[0].suspect && !split[2].suspect)
 702                /*
 703                 * The parent covers the entire area; reuse storage for
 704                 * e and replace it with the parent.
 705                 */
 706                dup_entry(e, &split[1]);
 707        else if (split[0].suspect) {
 708                /* me and then parent */
 709                dup_entry(e, &split[0]);
 710
 711                new_entry = xmalloc(sizeof(*new_entry));
 712                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 713                add_blame_entry(sb, new_entry);
 714        }
 715        else {
 716                /* parent and then me */
 717                dup_entry(e, &split[1]);
 718
 719                new_entry = xmalloc(sizeof(*new_entry));
 720                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 721                add_blame_entry(sb, new_entry);
 722        }
 723
 724        if (DEBUG) { /* sanity */
 725                struct blame_entry *ent;
 726                int lno = sb->ent->lno, corrupt = 0;
 727
 728                for (ent = sb->ent; ent; ent = ent->next) {
 729                        if (lno != ent->lno)
 730                                corrupt = 1;
 731                        if (ent->s_lno < 0)
 732                                corrupt = 1;
 733                        lno += ent->num_lines;
 734                }
 735                if (corrupt) {
 736                        lno = sb->ent->lno;
 737                        for (ent = sb->ent; ent; ent = ent->next) {
 738                                printf("L %8d l %8d n %8d\n",
 739                                       lno, ent->lno, ent->num_lines);
 740                                lno = ent->lno + ent->num_lines;
 741                        }
 742                        die("oops");
 743                }
 744        }
 745}
 746
 747/*
 748 * After splitting the blame, the origins used by the
 749 * on-stack blame_entry should lose one refcnt each.
 750 */
 751static void decref_split(struct blame_entry *split)
 752{
 753        int i;
 754
 755        for (i = 0; i < 3; i++)
 756                origin_decref(split[i].suspect);
 757}
 758
 759/*
 760 * Helper for blame_chunk().  blame_entry e is known to overlap with
 761 * the patch hunk; split it and pass blame to the parent.
 762 */
 763static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 764                          int tlno, int plno, int same,
 765                          struct origin *parent)
 766{
 767        struct blame_entry split[3];
 768
 769        split_overlap(split, e, tlno, plno, same, parent);
 770        if (split[1].suspect)
 771                split_blame(sb, split, e);
 772        decref_split(split);
 773}
 774
 775/*
 776 * Find the line number of the last line the target is suspected for.
 777 */
 778static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 779{
 780        struct blame_entry *e;
 781        int last_in_target = -1;
 782
 783        for (e = sb->ent; e; e = e->next) {
 784                if (e->guilty || !same_suspect(e->suspect, target))
 785                        continue;
 786                if (last_in_target < e->s_lno + e->num_lines)
 787                        last_in_target = e->s_lno + e->num_lines;
 788        }
 789        return last_in_target;
 790}
 791
 792/*
 793 * Process one hunk from the patch between the current suspect for
 794 * blame_entry e and its parent.  Find and split the overlap, and
 795 * pass blame to the overlapping part to the parent.
 796 */
 797static void blame_chunk(struct scoreboard *sb,
 798                        int tlno, int plno, int same,
 799                        struct origin *target, struct origin *parent)
 800{
 801        struct blame_entry *e;
 802
 803        for (e = sb->ent; e; e = e->next) {
 804                if (e->guilty || !same_suspect(e->suspect, target))
 805                        continue;
 806                if (same <= e->s_lno)
 807                        continue;
 808                if (tlno < e->s_lno + e->num_lines)
 809                        blame_overlap(sb, e, tlno, plno, same, parent);
 810        }
 811}
 812
 813/*
 814 * We are looking at the origin 'target' and aiming to pass blame
 815 * for the lines it is suspected to its parent.  Run diff to find
 816 * which lines came from parent and pass blame for them.
 817 */
 818static int pass_blame_to_parent(struct scoreboard *sb,
 819                                struct origin *target,
 820                                struct origin *parent)
 821{
 822        int i, last_in_target, plno, tlno;
 823        struct patch *patch;
 824
 825        last_in_target = find_last_in_target(sb, target);
 826        if (last_in_target < 0)
 827                return 1; /* nothing remains for this target */
 828
 829        patch = get_patch(parent, target);
 830        plno = tlno = 0;
 831        for (i = 0; i < patch->num; i++) {
 832                struct chunk *chunk = &patch->chunks[i];
 833
 834                blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 835                plno = chunk->p_next;
 836                tlno = chunk->t_next;
 837        }
 838        /* The rest (i.e. anything after tlno) are the same as the parent */
 839        blame_chunk(sb, tlno, plno, last_in_target, target, parent);
 840
 841        free_patch(patch);
 842        return 0;
 843}
 844
 845/*
 846 * The lines in blame_entry after splitting blames many times can become
 847 * very small and trivial, and at some point it becomes pointless to
 848 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 849 * ordinary C program, and it is not worth to say it was copied from
 850 * totally unrelated file in the parent.
 851 *
 852 * Compute how trivial the lines in the blame_entry are.
 853 */
 854static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 855{
 856        unsigned score;
 857        const char *cp, *ep;
 858
 859        if (e->score)
 860                return e->score;
 861
 862        score = 1;
 863        cp = nth_line(sb, e->lno);
 864        ep = nth_line(sb, e->lno + e->num_lines);
 865        while (cp < ep) {
 866                unsigned ch = *((unsigned char *)cp);
 867                if (isalnum(ch))
 868                        score++;
 869                cp++;
 870        }
 871        e->score = score;
 872        return score;
 873}
 874
 875/*
 876 * best_so_far[] and this[] are both a split of an existing blame_entry
 877 * that passes blame to the parent.  Maintain best_so_far the best split
 878 * so far, by comparing this and best_so_far and copying this into
 879 * bst_so_far as needed.
 880 */
 881static void copy_split_if_better(struct scoreboard *sb,
 882                                 struct blame_entry *best_so_far,
 883                                 struct blame_entry *this)
 884{
 885        int i;
 886
 887        if (!this[1].suspect)
 888                return;
 889        if (best_so_far[1].suspect) {
 890                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 891                        return;
 892        }
 893
 894        for (i = 0; i < 3; i++)
 895                origin_incref(this[i].suspect);
 896        decref_split(best_so_far);
 897        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 898}
 899
 900/*
 901 * We are looking at a part of the final image represented by
 902 * ent (tlno and same are offset by ent->s_lno).
 903 * tlno is where we are looking at in the final image.
 904 * up to (but not including) same match preimage.
 905 * plno is where we are looking at in the preimage.
 906 *
 907 * <-------------- final image ---------------------->
 908 *       <------ent------>
 909 *         ^tlno ^same
 910 *    <---------preimage----->
 911 *         ^plno
 912 *
 913 * All line numbers are 0-based.
 914 */
 915static void handle_split(struct scoreboard *sb,
 916                         struct blame_entry *ent,
 917                         int tlno, int plno, int same,
 918                         struct origin *parent,
 919                         struct blame_entry *split)
 920{
 921        if (ent->num_lines <= tlno)
 922                return;
 923        if (tlno < same) {
 924                struct blame_entry this[3];
 925                tlno += ent->s_lno;
 926                same += ent->s_lno;
 927                split_overlap(this, ent, tlno, plno, same, parent);
 928                copy_split_if_better(sb, split, this);
 929                decref_split(this);
 930        }
 931}
 932
 933/*
 934 * Find the lines from parent that are the same as ent so that
 935 * we can pass blames to it.  file_p has the blob contents for
 936 * the parent.
 937 */
 938static void find_copy_in_blob(struct scoreboard *sb,
 939                              struct blame_entry *ent,
 940                              struct origin *parent,
 941                              struct blame_entry *split,
 942                              mmfile_t *file_p)
 943{
 944        const char *cp;
 945        int cnt;
 946        mmfile_t file_o;
 947        struct patch *patch;
 948        int i, plno, tlno;
 949
 950        /*
 951         * Prepare mmfile that contains only the lines in ent.
 952         */
 953        cp = nth_line(sb, ent->lno);
 954        file_o.ptr = (char*) cp;
 955        cnt = ent->num_lines;
 956
 957        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 958                if (*cp++ == '\n')
 959                        cnt--;
 960        }
 961        file_o.size = cp - file_o.ptr;
 962
 963        patch = compare_buffer(file_p, &file_o, 1);
 964
 965        /*
 966         * file_o is a part of final image we are annotating.
 967         * file_p partially may match that image.
 968         */
 969        memset(split, 0, sizeof(struct blame_entry [3]));
 970        plno = tlno = 0;
 971        for (i = 0; i < patch->num; i++) {
 972                struct chunk *chunk = &patch->chunks[i];
 973
 974                handle_split(sb, ent, tlno, plno, chunk->same, parent, split);
 975                plno = chunk->p_next;
 976                tlno = chunk->t_next;
 977        }
 978        /* remainder, if any, all match the preimage */
 979        handle_split(sb, ent, tlno, plno, ent->num_lines, parent, split);
 980        free_patch(patch);
 981}
 982
 983/*
 984 * See if lines currently target is suspected for can be attributed to
 985 * parent.
 986 */
 987static int find_move_in_parent(struct scoreboard *sb,
 988                               struct origin *target,
 989                               struct origin *parent)
 990{
 991        int last_in_target, made_progress;
 992        struct blame_entry *e, split[3];
 993        mmfile_t file_p;
 994
 995        last_in_target = find_last_in_target(sb, target);
 996        if (last_in_target < 0)
 997                return 1; /* nothing remains for this target */
 998
 999        fill_origin_blob(parent, &file_p);
1000        if (!file_p.ptr)
1001                return 0;
1002
1003        made_progress = 1;
1004        while (made_progress) {
1005                made_progress = 0;
1006                for (e = sb->ent; e; e = e->next) {
1007                        if (e->guilty || !same_suspect(e->suspect, target))
1008                                continue;
1009                        find_copy_in_blob(sb, e, parent, split, &file_p);
1010                        if (split[1].suspect &&
1011                            blame_move_score < ent_score(sb, &split[1])) {
1012                                split_blame(sb, split, e);
1013                                made_progress = 1;
1014                        }
1015                        decref_split(split);
1016                }
1017        }
1018        return 0;
1019}
1020
1021struct blame_list {
1022        struct blame_entry *ent;
1023        struct blame_entry split[3];
1024};
1025
1026/*
1027 * Count the number of entries the target is suspected for,
1028 * and prepare a list of entry and the best split.
1029 */
1030static struct blame_list *setup_blame_list(struct scoreboard *sb,
1031                                           struct origin *target,
1032                                           int *num_ents_p)
1033{
1034        struct blame_entry *e;
1035        int num_ents, i;
1036        struct blame_list *blame_list = NULL;
1037
1038        for (e = sb->ent, num_ents = 0; e; e = e->next)
1039                if (!e->guilty && same_suspect(e->suspect, target))
1040                        num_ents++;
1041        if (num_ents) {
1042                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1043                for (e = sb->ent, i = 0; e; e = e->next)
1044                        if (!e->guilty && same_suspect(e->suspect, target))
1045                                blame_list[i++].ent = e;
1046        }
1047        *num_ents_p = num_ents;
1048        return blame_list;
1049}
1050
1051/*
1052 * For lines target is suspected for, see if we can find code movement
1053 * across file boundary from the parent commit.  porigin is the path
1054 * in the parent we already tried.
1055 */
1056static int find_copy_in_parent(struct scoreboard *sb,
1057                               struct origin *target,
1058                               struct commit *parent,
1059                               struct origin *porigin,
1060                               int opt)
1061{
1062        struct diff_options diff_opts;
1063        const char *paths[1];
1064        int i, j;
1065        int retval;
1066        struct blame_list *blame_list;
1067        int num_ents;
1068
1069        blame_list = setup_blame_list(sb, target, &num_ents);
1070        if (!blame_list)
1071                return 1; /* nothing remains for this target */
1072
1073        diff_setup(&diff_opts);
1074        diff_opts.recursive = 1;
1075        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1076
1077        paths[0] = NULL;
1078        diff_tree_setup_paths(paths, &diff_opts);
1079        if (diff_setup_done(&diff_opts) < 0)
1080                die("diff-setup");
1081
1082        /* Try "find copies harder" on new path if requested;
1083         * we do not want to use diffcore_rename() actually to
1084         * match things up; find_copies_harder is set only to
1085         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1086         * and this code needs to be after diff_setup_done(), which
1087         * usually makes find-copies-harder imply copy detection.
1088         */
1089        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1090            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1091                && (!porigin || strcmp(target->path, porigin->path))))
1092                diff_opts.find_copies_harder = 1;
1093
1094        if (is_null_sha1(target->commit->object.sha1))
1095                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1096        else
1097                diff_tree_sha1(parent->tree->object.sha1,
1098                               target->commit->tree->object.sha1,
1099                               "", &diff_opts);
1100
1101        if (!diff_opts.find_copies_harder)
1102                diffcore_std(&diff_opts);
1103
1104        retval = 0;
1105        while (1) {
1106                int made_progress = 0;
1107
1108                for (i = 0; i < diff_queued_diff.nr; i++) {
1109                        struct diff_filepair *p = diff_queued_diff.queue[i];
1110                        struct origin *norigin;
1111                        mmfile_t file_p;
1112                        struct blame_entry this[3];
1113
1114                        if (!DIFF_FILE_VALID(p->one))
1115                                continue; /* does not exist in parent */
1116                        if (porigin && !strcmp(p->one->path, porigin->path))
1117                                /* find_move already dealt with this path */
1118                                continue;
1119
1120                        norigin = get_origin(sb, parent, p->one->path);
1121                        hashcpy(norigin->blob_sha1, p->one->sha1);
1122                        fill_origin_blob(norigin, &file_p);
1123                        if (!file_p.ptr)
1124                                continue;
1125
1126                        for (j = 0; j < num_ents; j++) {
1127                                find_copy_in_blob(sb, blame_list[j].ent,
1128                                                  norigin, this, &file_p);
1129                                copy_split_if_better(sb, blame_list[j].split,
1130                                                     this);
1131                                decref_split(this);
1132                        }
1133                        origin_decref(norigin);
1134                }
1135
1136                for (j = 0; j < num_ents; j++) {
1137                        struct blame_entry *split = blame_list[j].split;
1138                        if (split[1].suspect &&
1139                            blame_copy_score < ent_score(sb, &split[1])) {
1140                                split_blame(sb, split, blame_list[j].ent);
1141                                made_progress = 1;
1142                        }
1143                        decref_split(split);
1144                }
1145                free(blame_list);
1146
1147                if (!made_progress)
1148                        break;
1149                blame_list = setup_blame_list(sb, target, &num_ents);
1150                if (!blame_list) {
1151                        retval = 1;
1152                        break;
1153                }
1154        }
1155        diff_flush(&diff_opts);
1156
1157        return retval;
1158}
1159
1160/*
1161 * The blobs of origin and porigin exactly match, so everything
1162 * origin is suspected for can be blamed on the parent.
1163 */
1164static void pass_whole_blame(struct scoreboard *sb,
1165                             struct origin *origin, struct origin *porigin)
1166{
1167        struct blame_entry *e;
1168
1169        if (!porigin->file.ptr && origin->file.ptr) {
1170                /* Steal its file */
1171                porigin->file = origin->file;
1172                origin->file.ptr = NULL;
1173        }
1174        for (e = sb->ent; e; e = e->next) {
1175                if (!same_suspect(e->suspect, origin))
1176                        continue;
1177                origin_incref(porigin);
1178                origin_decref(e->suspect);
1179                e->suspect = porigin;
1180        }
1181}
1182
1183#define MAXPARENT 16
1184
1185static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1186{
1187        int i, pass;
1188        struct commit *commit = origin->commit;
1189        struct commit_list *parent;
1190        struct origin *parent_origin[MAXPARENT], *porigin;
1191
1192        memset(parent_origin, 0, sizeof(parent_origin));
1193
1194        /* The first pass looks for unrenamed path to optimize for
1195         * common cases, then we look for renames in the second pass.
1196         */
1197        for (pass = 0; pass < 2; pass++) {
1198                struct origin *(*find)(struct scoreboard *,
1199                                       struct commit *, struct origin *);
1200                find = pass ? find_rename : find_origin;
1201
1202                for (i = 0, parent = commit->parents;
1203                     i < MAXPARENT && parent;
1204                     parent = parent->next, i++) {
1205                        struct commit *p = parent->item;
1206                        int j, same;
1207
1208                        if (parent_origin[i])
1209                                continue;
1210                        if (parse_commit(p))
1211                                continue;
1212                        porigin = find(sb, p, origin);
1213                        if (!porigin)
1214                                continue;
1215                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1216                                pass_whole_blame(sb, origin, porigin);
1217                                origin_decref(porigin);
1218                                goto finish;
1219                        }
1220                        for (j = same = 0; j < i; j++)
1221                                if (parent_origin[j] &&
1222                                    !hashcmp(parent_origin[j]->blob_sha1,
1223                                             porigin->blob_sha1)) {
1224                                        same = 1;
1225                                        break;
1226                                }
1227                        if (!same)
1228                                parent_origin[i] = porigin;
1229                        else
1230                                origin_decref(porigin);
1231                }
1232        }
1233
1234        num_commits++;
1235        for (i = 0, parent = commit->parents;
1236             i < MAXPARENT && parent;
1237             parent = parent->next, i++) {
1238                struct origin *porigin = parent_origin[i];
1239                if (!porigin)
1240                        continue;
1241                if (pass_blame_to_parent(sb, origin, porigin))
1242                        goto finish;
1243        }
1244
1245        /*
1246         * Optionally find moves in parents' files.
1247         */
1248        if (opt & PICKAXE_BLAME_MOVE)
1249                for (i = 0, parent = commit->parents;
1250                     i < MAXPARENT && parent;
1251                     parent = parent->next, i++) {
1252                        struct origin *porigin = parent_origin[i];
1253                        if (!porigin)
1254                                continue;
1255                        if (find_move_in_parent(sb, origin, porigin))
1256                                goto finish;
1257                }
1258
1259        /*
1260         * Optionally find copies from parents' files.
1261         */
1262        if (opt & PICKAXE_BLAME_COPY)
1263                for (i = 0, parent = commit->parents;
1264                     i < MAXPARENT && parent;
1265                     parent = parent->next, i++) {
1266                        struct origin *porigin = parent_origin[i];
1267                        if (find_copy_in_parent(sb, origin, parent->item,
1268                                                porigin, opt))
1269                                goto finish;
1270                }
1271
1272 finish:
1273        for (i = 0; i < MAXPARENT; i++)
1274                origin_decref(parent_origin[i]);
1275}
1276
1277/*
1278 * Information on commits, used for output.
1279 */
1280struct commit_info
1281{
1282        const char *author;
1283        const char *author_mail;
1284        unsigned long author_time;
1285        const char *author_tz;
1286
1287        /* filled only when asked for details */
1288        const char *committer;
1289        const char *committer_mail;
1290        unsigned long committer_time;
1291        const char *committer_tz;
1292
1293        const char *summary;
1294};
1295
1296/*
1297 * Parse author/committer line in the commit object buffer
1298 */
1299static void get_ac_line(const char *inbuf, const char *what,
1300                        int bufsz, char *person, const char **mail,
1301                        unsigned long *time, const char **tz)
1302{
1303        int len, tzlen, maillen;
1304        char *tmp, *endp, *timepos;
1305
1306        tmp = strstr(inbuf, what);
1307        if (!tmp)
1308                goto error_out;
1309        tmp += strlen(what);
1310        endp = strchr(tmp, '\n');
1311        if (!endp)
1312                len = strlen(tmp);
1313        else
1314                len = endp - tmp;
1315        if (bufsz <= len) {
1316        error_out:
1317                /* Ugh */
1318                *mail = *tz = "(unknown)";
1319                *time = 0;
1320                return;
1321        }
1322        memcpy(person, tmp, len);
1323
1324        tmp = person;
1325        tmp += len;
1326        *tmp = 0;
1327        while (*tmp != ' ')
1328                tmp--;
1329        *tz = tmp+1;
1330        tzlen = (person+len)-(tmp+1);
1331
1332        *tmp = 0;
1333        while (*tmp != ' ')
1334                tmp--;
1335        *time = strtoul(tmp, NULL, 10);
1336        timepos = tmp;
1337
1338        *tmp = 0;
1339        while (*tmp != ' ')
1340                tmp--;
1341        *mail = tmp + 1;
1342        *tmp = 0;
1343        maillen = timepos - tmp;
1344
1345        if (!mailmap.nr)
1346                return;
1347
1348        /*
1349         * mailmap expansion may make the name longer.
1350         * make room by pushing stuff down.
1351         */
1352        tmp = person + bufsz - (tzlen + 1);
1353        memmove(tmp, *tz, tzlen);
1354        tmp[tzlen] = 0;
1355        *tz = tmp;
1356
1357        tmp = tmp - (maillen + 1);
1358        memmove(tmp, *mail, maillen);
1359        tmp[maillen] = 0;
1360        *mail = tmp;
1361
1362        /*
1363         * Now, convert e-mail using mailmap
1364         */
1365        map_email(&mailmap, tmp + 1, person, tmp-person-1);
1366}
1367
1368static void get_commit_info(struct commit *commit,
1369                            struct commit_info *ret,
1370                            int detailed)
1371{
1372        int len;
1373        char *tmp, *endp;
1374        static char author_buf[1024];
1375        static char committer_buf[1024];
1376        static char summary_buf[1024];
1377
1378        /*
1379         * We've operated without save_commit_buffer, so
1380         * we now need to populate them for output.
1381         */
1382        if (!commit->buffer) {
1383                enum object_type type;
1384                unsigned long size;
1385                commit->buffer =
1386                        read_sha1_file(commit->object.sha1, &type, &size);
1387        }
1388        ret->author = author_buf;
1389        get_ac_line(commit->buffer, "\nauthor ",
1390                    sizeof(author_buf), author_buf, &ret->author_mail,
1391                    &ret->author_time, &ret->author_tz);
1392
1393        if (!detailed)
1394                return;
1395
1396        ret->committer = committer_buf;
1397        get_ac_line(commit->buffer, "\ncommitter ",
1398                    sizeof(committer_buf), committer_buf, &ret->committer_mail,
1399                    &ret->committer_time, &ret->committer_tz);
1400
1401        ret->summary = summary_buf;
1402        tmp = strstr(commit->buffer, "\n\n");
1403        if (!tmp) {
1404        error_out:
1405                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1406                return;
1407        }
1408        tmp += 2;
1409        endp = strchr(tmp, '\n');
1410        if (!endp)
1411                endp = tmp + strlen(tmp);
1412        len = endp - tmp;
1413        if (len >= sizeof(summary_buf) || len == 0)
1414                goto error_out;
1415        memcpy(summary_buf, tmp, len);
1416        summary_buf[len] = 0;
1417}
1418
1419/*
1420 * To allow LF and other nonportable characters in pathnames,
1421 * they are c-style quoted as needed.
1422 */
1423static void write_filename_info(const char *path)
1424{
1425        printf("filename ");
1426        write_name_quoted(NULL, 0, path, 1, stdout);
1427        putchar('\n');
1428}
1429
1430/*
1431 * The blame_entry is found to be guilty for the range.  Mark it
1432 * as such, and show it in incremental output.
1433 */
1434static void found_guilty_entry(struct blame_entry *ent)
1435{
1436        if (ent->guilty)
1437                return;
1438        ent->guilty = 1;
1439        if (incremental) {
1440                struct origin *suspect = ent->suspect;
1441
1442                printf("%s %d %d %d\n",
1443                       sha1_to_hex(suspect->commit->object.sha1),
1444                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1445                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1446                        struct commit_info ci;
1447                        suspect->commit->object.flags |= METAINFO_SHOWN;
1448                        get_commit_info(suspect->commit, &ci, 1);
1449                        printf("author %s\n", ci.author);
1450                        printf("author-mail %s\n", ci.author_mail);
1451                        printf("author-time %lu\n", ci.author_time);
1452                        printf("author-tz %s\n", ci.author_tz);
1453                        printf("committer %s\n", ci.committer);
1454                        printf("committer-mail %s\n", ci.committer_mail);
1455                        printf("committer-time %lu\n", ci.committer_time);
1456                        printf("committer-tz %s\n", ci.committer_tz);
1457                        printf("summary %s\n", ci.summary);
1458                        if (suspect->commit->object.flags & UNINTERESTING)
1459                                printf("boundary\n");
1460                }
1461                write_filename_info(suspect->path);
1462                maybe_flush_or_die(stdout, "stdout");
1463        }
1464}
1465
1466/*
1467 * The main loop -- while the scoreboard has lines whose true origin
1468 * is still unknown, pick one blame_entry, and allow its current
1469 * suspect to pass blames to its parents.
1470 */
1471static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1472{
1473        while (1) {
1474                struct blame_entry *ent;
1475                struct commit *commit;
1476                struct origin *suspect = NULL;
1477
1478                /* find one suspect to break down */
1479                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1480                        if (!ent->guilty)
1481                                suspect = ent->suspect;
1482                if (!suspect)
1483                        return; /* all done */
1484
1485                /*
1486                 * We will use this suspect later in the loop,
1487                 * so hold onto it in the meantime.
1488                 */
1489                origin_incref(suspect);
1490                commit = suspect->commit;
1491                if (!commit->object.parsed)
1492                        parse_commit(commit);
1493                if (!(commit->object.flags & UNINTERESTING) &&
1494                    !(revs->max_age != -1 && commit->date < revs->max_age))
1495                        pass_blame(sb, suspect, opt);
1496                else {
1497                        commit->object.flags |= UNINTERESTING;
1498                        if (commit->object.parsed)
1499                                mark_parents_uninteresting(commit);
1500                }
1501                /* treat root commit as boundary */
1502                if (!commit->parents && !show_root)
1503                        commit->object.flags |= UNINTERESTING;
1504
1505                /* Take responsibility for the remaining entries */
1506                for (ent = sb->ent; ent; ent = ent->next)
1507                        if (same_suspect(ent->suspect, suspect))
1508                                found_guilty_entry(ent);
1509                origin_decref(suspect);
1510
1511                if (DEBUG) /* sanity */
1512                        sanity_check_refcnt(sb);
1513        }
1514}
1515
1516static const char *format_time(unsigned long time, const char *tz_str,
1517                               int show_raw_time)
1518{
1519        static char time_buf[128];
1520        time_t t = time;
1521        int minutes, tz;
1522        struct tm *tm;
1523
1524        if (show_raw_time) {
1525                sprintf(time_buf, "%lu %s", time, tz_str);
1526                return time_buf;
1527        }
1528
1529        tz = atoi(tz_str);
1530        minutes = tz < 0 ? -tz : tz;
1531        minutes = (minutes / 100)*60 + (minutes % 100);
1532        minutes = tz < 0 ? -minutes : minutes;
1533        t = time + minutes * 60;
1534        tm = gmtime(&t);
1535
1536        strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1537        strcat(time_buf, tz_str);
1538        return time_buf;
1539}
1540
1541#define OUTPUT_ANNOTATE_COMPAT  001
1542#define OUTPUT_LONG_OBJECT_NAME 002
1543#define OUTPUT_RAW_TIMESTAMP    004
1544#define OUTPUT_PORCELAIN        010
1545#define OUTPUT_SHOW_NAME        020
1546#define OUTPUT_SHOW_NUMBER      040
1547#define OUTPUT_SHOW_SCORE      0100
1548#define OUTPUT_NO_AUTHOR       0200
1549
1550static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1551{
1552        int cnt;
1553        const char *cp;
1554        struct origin *suspect = ent->suspect;
1555        char hex[41];
1556
1557        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1558        printf("%s%c%d %d %d\n",
1559               hex,
1560               ent->guilty ? ' ' : '*', // purely for debugging
1561               ent->s_lno + 1,
1562               ent->lno + 1,
1563               ent->num_lines);
1564        if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1565                struct commit_info ci;
1566                suspect->commit->object.flags |= METAINFO_SHOWN;
1567                get_commit_info(suspect->commit, &ci, 1);
1568                printf("author %s\n", ci.author);
1569                printf("author-mail %s\n", ci.author_mail);
1570                printf("author-time %lu\n", ci.author_time);
1571                printf("author-tz %s\n", ci.author_tz);
1572                printf("committer %s\n", ci.committer);
1573                printf("committer-mail %s\n", ci.committer_mail);
1574                printf("committer-time %lu\n", ci.committer_time);
1575                printf("committer-tz %s\n", ci.committer_tz);
1576                write_filename_info(suspect->path);
1577                printf("summary %s\n", ci.summary);
1578                if (suspect->commit->object.flags & UNINTERESTING)
1579                        printf("boundary\n");
1580        }
1581        else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1582                write_filename_info(suspect->path);
1583
1584        cp = nth_line(sb, ent->lno);
1585        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1586                char ch;
1587                if (cnt)
1588                        printf("%s %d %d\n", hex,
1589                               ent->s_lno + 1 + cnt,
1590                               ent->lno + 1 + cnt);
1591                putchar('\t');
1592                do {
1593                        ch = *cp++;
1594                        putchar(ch);
1595                } while (ch != '\n' &&
1596                         cp < sb->final_buf + sb->final_buf_size);
1597        }
1598}
1599
1600static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1601{
1602        int cnt;
1603        const char *cp;
1604        struct origin *suspect = ent->suspect;
1605        struct commit_info ci;
1606        char hex[41];
1607        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1608
1609        get_commit_info(suspect->commit, &ci, 1);
1610        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1611
1612        cp = nth_line(sb, ent->lno);
1613        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1614                char ch;
1615                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1616
1617                if (suspect->commit->object.flags & UNINTERESTING) {
1618                        if (blank_boundary)
1619                                memset(hex, ' ', length);
1620                        else if (!cmd_is_annotate) {
1621                                length--;
1622                                putchar('^');
1623                        }
1624                }
1625
1626                printf("%.*s", length, hex);
1627                if (opt & OUTPUT_ANNOTATE_COMPAT)
1628                        printf("\t(%10s\t%10s\t%d)", ci.author,
1629                               format_time(ci.author_time, ci.author_tz,
1630                                           show_raw_time),
1631                               ent->lno + 1 + cnt);
1632                else {
1633                        if (opt & OUTPUT_SHOW_SCORE)
1634                                printf(" %*d %02d",
1635                                       max_score_digits, ent->score,
1636                                       ent->suspect->refcnt);
1637                        if (opt & OUTPUT_SHOW_NAME)
1638                                printf(" %-*.*s", longest_file, longest_file,
1639                                       suspect->path);
1640                        if (opt & OUTPUT_SHOW_NUMBER)
1641                                printf(" %*d", max_orig_digits,
1642                                       ent->s_lno + 1 + cnt);
1643
1644                        if (!(opt & OUTPUT_NO_AUTHOR))
1645                                printf(" (%-*.*s %10s",
1646                                       longest_author, longest_author,
1647                                       ci.author,
1648                                       format_time(ci.author_time,
1649                                                   ci.author_tz,
1650                                                   show_raw_time));
1651                        printf(" %*d) ",
1652                               max_digits, ent->lno + 1 + cnt);
1653                }
1654                do {
1655                        ch = *cp++;
1656                        putchar(ch);
1657                } while (ch != '\n' &&
1658                         cp < sb->final_buf + sb->final_buf_size);
1659        }
1660}
1661
1662static void output(struct scoreboard *sb, int option)
1663{
1664        struct blame_entry *ent;
1665
1666        if (option & OUTPUT_PORCELAIN) {
1667                for (ent = sb->ent; ent; ent = ent->next) {
1668                        struct blame_entry *oth;
1669                        struct origin *suspect = ent->suspect;
1670                        struct commit *commit = suspect->commit;
1671                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1672                                continue;
1673                        for (oth = ent->next; oth; oth = oth->next) {
1674                                if ((oth->suspect->commit != commit) ||
1675                                    !strcmp(oth->suspect->path, suspect->path))
1676                                        continue;
1677                                commit->object.flags |= MORE_THAN_ONE_PATH;
1678                                break;
1679                        }
1680                }
1681        }
1682
1683        for (ent = sb->ent; ent; ent = ent->next) {
1684                if (option & OUTPUT_PORCELAIN)
1685                        emit_porcelain(sb, ent);
1686                else {
1687                        emit_other(sb, ent, option);
1688                }
1689        }
1690}
1691
1692/*
1693 * To allow quick access to the contents of nth line in the
1694 * final image, prepare an index in the scoreboard.
1695 */
1696static int prepare_lines(struct scoreboard *sb)
1697{
1698        const char *buf = sb->final_buf;
1699        unsigned long len = sb->final_buf_size;
1700        int num = 0, incomplete = 0, bol = 1;
1701
1702        if (len && buf[len-1] != '\n')
1703                incomplete++; /* incomplete line at the end */
1704        while (len--) {
1705                if (bol) {
1706                        sb->lineno = xrealloc(sb->lineno,
1707                                              sizeof(int* ) * (num + 1));
1708                        sb->lineno[num] = buf - sb->final_buf;
1709                        bol = 0;
1710                }
1711                if (*buf++ == '\n') {
1712                        num++;
1713                        bol = 1;
1714                }
1715        }
1716        sb->lineno = xrealloc(sb->lineno,
1717                              sizeof(int* ) * (num + incomplete + 1));
1718        sb->lineno[num + incomplete] = buf - sb->final_buf;
1719        sb->num_lines = num + incomplete;
1720        return sb->num_lines;
1721}
1722
1723/*
1724 * Add phony grafts for use with -S; this is primarily to
1725 * support git-cvsserver that wants to give a linear history
1726 * to its clients.
1727 */
1728static int read_ancestry(const char *graft_file)
1729{
1730        FILE *fp = fopen(graft_file, "r");
1731        char buf[1024];
1732        if (!fp)
1733                return -1;
1734        while (fgets(buf, sizeof(buf), fp)) {
1735                /* The format is just "Commit Parent1 Parent2 ...\n" */
1736                int len = strlen(buf);
1737                struct commit_graft *graft = read_graft_line(buf, len);
1738                if (graft)
1739                        register_commit_graft(graft, 0);
1740        }
1741        fclose(fp);
1742        return 0;
1743}
1744
1745/*
1746 * How many columns do we need to show line numbers in decimal?
1747 */
1748static int lineno_width(int lines)
1749{
1750        int i, width;
1751
1752        for (width = 1, i = 10; i <= lines + 1; width++)
1753                i *= 10;
1754        return width;
1755}
1756
1757/*
1758 * How many columns do we need to show line numbers, authors,
1759 * and filenames?
1760 */
1761static void find_alignment(struct scoreboard *sb, int *option)
1762{
1763        int longest_src_lines = 0;
1764        int longest_dst_lines = 0;
1765        unsigned largest_score = 0;
1766        struct blame_entry *e;
1767
1768        for (e = sb->ent; e; e = e->next) {
1769                struct origin *suspect = e->suspect;
1770                struct commit_info ci;
1771                int num;
1772
1773                if (strcmp(suspect->path, sb->path))
1774                        *option |= OUTPUT_SHOW_NAME;
1775                num = strlen(suspect->path);
1776                if (longest_file < num)
1777                        longest_file = num;
1778                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1779                        suspect->commit->object.flags |= METAINFO_SHOWN;
1780                        get_commit_info(suspect->commit, &ci, 1);
1781                        num = strlen(ci.author);
1782                        if (longest_author < num)
1783                                longest_author = num;
1784                }
1785                num = e->s_lno + e->num_lines;
1786                if (longest_src_lines < num)
1787                        longest_src_lines = num;
1788                num = e->lno + e->num_lines;
1789                if (longest_dst_lines < num)
1790                        longest_dst_lines = num;
1791                if (largest_score < ent_score(sb, e))
1792                        largest_score = ent_score(sb, e);
1793        }
1794        max_orig_digits = lineno_width(longest_src_lines);
1795        max_digits = lineno_width(longest_dst_lines);
1796        max_score_digits = lineno_width(largest_score);
1797}
1798
1799/*
1800 * For debugging -- origin is refcounted, and this asserts that
1801 * we do not underflow.
1802 */
1803static void sanity_check_refcnt(struct scoreboard *sb)
1804{
1805        int baa = 0;
1806        struct blame_entry *ent;
1807
1808        for (ent = sb->ent; ent; ent = ent->next) {
1809                /* Nobody should have zero or negative refcnt */
1810                if (ent->suspect->refcnt <= 0) {
1811                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1812                                ent->suspect->path,
1813                                sha1_to_hex(ent->suspect->commit->object.sha1),
1814                                ent->suspect->refcnt);
1815                        baa = 1;
1816                }
1817        }
1818        for (ent = sb->ent; ent; ent = ent->next) {
1819                /* Mark the ones that haven't been checked */
1820                if (0 < ent->suspect->refcnt)
1821                        ent->suspect->refcnt = -ent->suspect->refcnt;
1822        }
1823        for (ent = sb->ent; ent; ent = ent->next) {
1824                /*
1825                 * ... then pick each and see if they have the the
1826                 * correct refcnt.
1827                 */
1828                int found;
1829                struct blame_entry *e;
1830                struct origin *suspect = ent->suspect;
1831
1832                if (0 < suspect->refcnt)
1833                        continue;
1834                suspect->refcnt = -suspect->refcnt; /* Unmark */
1835                for (found = 0, e = sb->ent; e; e = e->next) {
1836                        if (e->suspect != suspect)
1837                                continue;
1838                        found++;
1839                }
1840                if (suspect->refcnt != found) {
1841                        fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1842                                ent->suspect->path,
1843                                sha1_to_hex(ent->suspect->commit->object.sha1),
1844                                ent->suspect->refcnt, found);
1845                        baa = 2;
1846                }
1847        }
1848        if (baa) {
1849                int opt = 0160;
1850                find_alignment(sb, &opt);
1851                output(sb, opt);
1852                die("Baa %d!", baa);
1853        }
1854}
1855
1856/*
1857 * Used for the command line parsing; check if the path exists
1858 * in the working tree.
1859 */
1860static int has_path_in_work_tree(const char *path)
1861{
1862        struct stat st;
1863        return !lstat(path, &st);
1864}
1865
1866static unsigned parse_score(const char *arg)
1867{
1868        char *end;
1869        unsigned long score = strtoul(arg, &end, 10);
1870        if (*end)
1871                return 0;
1872        return score;
1873}
1874
1875static const char *add_prefix(const char *prefix, const char *path)
1876{
1877        if (!prefix || !prefix[0])
1878                return path;
1879        return prefix_path(prefix, strlen(prefix), path);
1880}
1881
1882/*
1883 * Parsing of (comma separated) one item in the -L option
1884 */
1885static const char *parse_loc(const char *spec,
1886                             struct scoreboard *sb, long lno,
1887                             long begin, long *ret)
1888{
1889        char *term;
1890        const char *line;
1891        long num;
1892        int reg_error;
1893        regex_t regexp;
1894        regmatch_t match[1];
1895
1896        /* Allow "-L <something>,+20" to mean starting at <something>
1897         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1898         * <something>.
1899         */
1900        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1901                num = strtol(spec + 1, &term, 10);
1902                if (term != spec + 1) {
1903                        if (spec[0] == '-')
1904                                num = 0 - num;
1905                        if (0 < num)
1906                                *ret = begin + num - 2;
1907                        else if (!num)
1908                                *ret = begin;
1909                        else
1910                                *ret = begin + num;
1911                        return term;
1912                }
1913                return spec;
1914        }
1915        num = strtol(spec, &term, 10);
1916        if (term != spec) {
1917                *ret = num;
1918                return term;
1919        }
1920        if (spec[0] != '/')
1921                return spec;
1922
1923        /* it could be a regexp of form /.../ */
1924        for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1925                if (*term == '\\')
1926                        term++;
1927        }
1928        if (*term != '/')
1929                return spec;
1930
1931        /* try [spec+1 .. term-1] as regexp */
1932        *term = 0;
1933        begin--; /* input is in human terms */
1934        line = nth_line(sb, begin);
1935
1936        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1937            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1938                const char *cp = line + match[0].rm_so;
1939                const char *nline;
1940
1941                while (begin++ < lno) {
1942                        nline = nth_line(sb, begin);
1943                        if (line <= cp && cp < nline)
1944                                break;
1945                        line = nline;
1946                }
1947                *ret = begin;
1948                regfree(&regexp);
1949                *term++ = '/';
1950                return term;
1951        }
1952        else {
1953                char errbuf[1024];
1954                regerror(reg_error, &regexp, errbuf, 1024);
1955                die("-L parameter '%s': %s", spec + 1, errbuf);
1956        }
1957}
1958
1959/*
1960 * Parsing of -L option
1961 */
1962static void prepare_blame_range(struct scoreboard *sb,
1963                                const char *bottomtop,
1964                                long lno,
1965                                long *bottom, long *top)
1966{
1967        const char *term;
1968
1969        term = parse_loc(bottomtop, sb, lno, 1, bottom);
1970        if (*term == ',') {
1971                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1972                if (*term)
1973                        usage(blame_usage);
1974        }
1975        if (*term)
1976                usage(blame_usage);
1977}
1978
1979static int git_blame_config(const char *var, const char *value)
1980{
1981        if (!strcmp(var, "blame.showroot")) {
1982                show_root = git_config_bool(var, value);
1983                return 0;
1984        }
1985        if (!strcmp(var, "blame.blankboundary")) {
1986                blank_boundary = git_config_bool(var, value);
1987                return 0;
1988        }
1989        return git_default_config(var, value);
1990}
1991
1992static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1993{
1994        struct commit *commit;
1995        struct origin *origin;
1996        unsigned char head_sha1[20];
1997        char *buf;
1998        const char *ident;
1999        int fd;
2000        time_t now;
2001        unsigned long fin_size;
2002        int size, len;
2003        struct cache_entry *ce;
2004        unsigned mode;
2005
2006        if (get_sha1("HEAD", head_sha1))
2007                die("No such ref: HEAD");
2008
2009        time(&now);
2010        commit = xcalloc(1, sizeof(*commit));
2011        commit->parents = xcalloc(1, sizeof(*commit->parents));
2012        commit->parents->item = lookup_commit_reference(head_sha1);
2013        commit->object.parsed = 1;
2014        commit->date = now;
2015        commit->object.type = OBJ_COMMIT;
2016
2017        origin = make_origin(commit, path);
2018
2019        if (!contents_from || strcmp("-", contents_from)) {
2020                struct stat st;
2021                const char *read_from;
2022
2023                if (contents_from) {
2024                        if (stat(contents_from, &st) < 0)
2025                                die("Cannot stat %s", contents_from);
2026                        read_from = contents_from;
2027                }
2028                else {
2029                        if (lstat(path, &st) < 0)
2030                                die("Cannot lstat %s", path);
2031                        read_from = path;
2032                }
2033                fin_size = xsize_t(st.st_size);
2034                buf = xmalloc(fin_size+1);
2035                mode = canon_mode(st.st_mode);
2036                switch (st.st_mode & S_IFMT) {
2037                case S_IFREG:
2038                        fd = open(read_from, O_RDONLY);
2039                        if (fd < 0)
2040                                die("cannot open %s", read_from);
2041                        if (read_in_full(fd, buf, fin_size) != fin_size)
2042                                die("cannot read %s", read_from);
2043                        break;
2044                case S_IFLNK:
2045                        if (readlink(read_from, buf, fin_size+1) != fin_size)
2046                                die("cannot readlink %s", read_from);
2047                        break;
2048                default:
2049                        die("unsupported file type %s", read_from);
2050                }
2051        }
2052        else {
2053                /* Reading from stdin */
2054                contents_from = "standard input";
2055                buf = NULL;
2056                fin_size = 0;
2057                mode = 0;
2058                while (1) {
2059                        ssize_t cnt = 8192;
2060                        buf = xrealloc(buf, fin_size + cnt);
2061                        cnt = xread(0, buf + fin_size, cnt);
2062                        if (cnt < 0)
2063                                die("read error %s from stdin",
2064                                    strerror(errno));
2065                        if (!cnt)
2066                                break;
2067                        fin_size += cnt;
2068                }
2069                buf = xrealloc(buf, fin_size + 1);
2070        }
2071        buf[fin_size] = 0;
2072        origin->file.ptr = buf;
2073        origin->file.size = fin_size;
2074        pretend_sha1_file(buf, fin_size, OBJ_BLOB, origin->blob_sha1);
2075        commit->util = origin;
2076
2077        /*
2078         * Read the current index, replace the path entry with
2079         * origin->blob_sha1 without mucking with its mode or type
2080         * bits; we are not going to write this index out -- we just
2081         * want to run "diff-index --cached".
2082         */
2083        discard_cache();
2084        read_cache();
2085
2086        len = strlen(path);
2087        if (!mode) {
2088                int pos = cache_name_pos(path, len);
2089                if (0 <= pos)
2090                        mode = ntohl(active_cache[pos]->ce_mode);
2091                else
2092                        /* Let's not bother reading from HEAD tree */
2093                        mode = S_IFREG | 0644;
2094        }
2095        size = cache_entry_size(len);
2096        ce = xcalloc(1, size);
2097        hashcpy(ce->sha1, origin->blob_sha1);
2098        memcpy(ce->name, path, len);
2099        ce->ce_flags = create_ce_flags(len, 0);
2100        ce->ce_mode = create_ce_mode(mode);
2101        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2102
2103        /*
2104         * We are not going to write this out, so this does not matter
2105         * right now, but someday we might optimize diff-index --cached
2106         * with cache-tree information.
2107         */
2108        cache_tree_invalidate_path(active_cache_tree, path);
2109
2110        commit->buffer = xmalloc(400);
2111        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2112        snprintf(commit->buffer, 400,
2113                "tree 0000000000000000000000000000000000000000\n"
2114                "parent %s\n"
2115                "author %s\n"
2116                "committer %s\n\n"
2117                "Version of %s from %s\n",
2118                sha1_to_hex(head_sha1),
2119                ident, ident, path, contents_from ? contents_from : path);
2120        return commit;
2121}
2122
2123int cmd_blame(int argc, const char **argv, const char *prefix)
2124{
2125        struct rev_info revs;
2126        const char *path;
2127        struct scoreboard sb;
2128        struct origin *o;
2129        struct blame_entry *ent;
2130        int i, seen_dashdash, unk, opt;
2131        long bottom, top, lno;
2132        int output_option = 0;
2133        int show_stats = 0;
2134        const char *revs_file = NULL;
2135        const char *final_commit_name = NULL;
2136        enum object_type type;
2137        const char *bottomtop = NULL;
2138        const char *contents_from = NULL;
2139
2140        cmd_is_annotate = !strcmp(argv[0], "annotate");
2141
2142        git_config(git_blame_config);
2143        save_commit_buffer = 0;
2144
2145        opt = 0;
2146        seen_dashdash = 0;
2147        for (unk = i = 1; i < argc; i++) {
2148                const char *arg = argv[i];
2149                if (*arg != '-')
2150                        break;
2151                else if (!strcmp("-b", arg))
2152                        blank_boundary = 1;
2153                else if (!strcmp("--root", arg))
2154                        show_root = 1;
2155                else if (!strcmp(arg, "--show-stats"))
2156                        show_stats = 1;
2157                else if (!strcmp("-c", arg))
2158                        output_option |= OUTPUT_ANNOTATE_COMPAT;
2159                else if (!strcmp("-t", arg))
2160                        output_option |= OUTPUT_RAW_TIMESTAMP;
2161                else if (!strcmp("-l", arg))
2162                        output_option |= OUTPUT_LONG_OBJECT_NAME;
2163                else if (!strcmp("-s", arg))
2164                        output_option |= OUTPUT_NO_AUTHOR;
2165                else if (!strcmp("-w", arg))
2166                        xdl_opts |= XDF_IGNORE_WHITESPACE;
2167                else if (!strcmp("-S", arg) && ++i < argc)
2168                        revs_file = argv[i];
2169                else if (!prefixcmp(arg, "-M")) {
2170                        opt |= PICKAXE_BLAME_MOVE;
2171                        blame_move_score = parse_score(arg+2);
2172                }
2173                else if (!prefixcmp(arg, "-C")) {
2174                        /*
2175                         * -C enables copy from removed files;
2176                         * -C -C enables copy from existing files, but only
2177                         *       when blaming a new file;
2178                         * -C -C -C enables copy from existing files for
2179                         *          everybody
2180                         */
2181                        if (opt & PICKAXE_BLAME_COPY_HARDER)
2182                                opt |= PICKAXE_BLAME_COPY_HARDEST;
2183                        if (opt & PICKAXE_BLAME_COPY)
2184                                opt |= PICKAXE_BLAME_COPY_HARDER;
2185                        opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2186                        blame_copy_score = parse_score(arg+2);
2187                }
2188                else if (!prefixcmp(arg, "-L")) {
2189                        if (!arg[2]) {
2190                                if (++i >= argc)
2191                                        usage(blame_usage);
2192                                arg = argv[i];
2193                        }
2194                        else
2195                                arg += 2;
2196                        if (bottomtop)
2197                                die("More than one '-L n,m' option given");
2198                        bottomtop = arg;
2199                }
2200                else if (!strcmp("--contents", arg)) {
2201                        if (++i >= argc)
2202                                usage(blame_usage);
2203                        contents_from = argv[i];
2204                }
2205                else if (!strcmp("--incremental", arg))
2206                        incremental = 1;
2207                else if (!strcmp("--score-debug", arg))
2208                        output_option |= OUTPUT_SHOW_SCORE;
2209                else if (!strcmp("-f", arg) ||
2210                         !strcmp("--show-name", arg))
2211                        output_option |= OUTPUT_SHOW_NAME;
2212                else if (!strcmp("-n", arg) ||
2213                         !strcmp("--show-number", arg))
2214                        output_option |= OUTPUT_SHOW_NUMBER;
2215                else if (!strcmp("-p", arg) ||
2216                         !strcmp("--porcelain", arg))
2217                        output_option |= OUTPUT_PORCELAIN;
2218                else if (!strcmp("--", arg)) {
2219                        seen_dashdash = 1;
2220                        i++;
2221                        break;
2222                }
2223                else
2224                        argv[unk++] = arg;
2225        }
2226
2227        if (!incremental)
2228                setup_pager();
2229
2230        if (!blame_move_score)
2231                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2232        if (!blame_copy_score)
2233                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2234
2235        /*
2236         * We have collected options unknown to us in argv[1..unk]
2237         * which are to be passed to revision machinery if we are
2238         * going to do the "bottom" processing.
2239         *
2240         * The remaining are:
2241         *
2242         * (1) if seen_dashdash, its either
2243         *     "-options -- <path>" or
2244         *     "-options -- <path> <rev>".
2245         *     but the latter is allowed only if there is no
2246         *     options that we passed to revision machinery.
2247         *
2248         * (2) otherwise, we may have "--" somewhere later and
2249         *     might be looking at the first one of multiple 'rev'
2250         *     parameters (e.g. " master ^next ^maint -- path").
2251         *     See if there is a dashdash first, and give the
2252         *     arguments before that to revision machinery.
2253         *     After that there must be one 'path'.
2254         *
2255         * (3) otherwise, its one of the three:
2256         *     "-options <path> <rev>"
2257         *     "-options <rev> <path>"
2258         *     "-options <path>"
2259         *     but again the first one is allowed only if
2260         *     there is no options that we passed to revision
2261         *     machinery.
2262         */
2263
2264        if (seen_dashdash) {
2265                /* (1) */
2266                if (argc <= i)
2267                        usage(blame_usage);
2268                path = add_prefix(prefix, argv[i]);
2269                if (i + 1 == argc - 1) {
2270                        if (unk != 1)
2271                                usage(blame_usage);
2272                        argv[unk++] = argv[i + 1];
2273                }
2274                else if (i + 1 != argc)
2275                        /* garbage at end */
2276                        usage(blame_usage);
2277        }
2278        else {
2279                int j;
2280                for (j = i; !seen_dashdash && j < argc; j++)
2281                        if (!strcmp(argv[j], "--"))
2282                                seen_dashdash = j;
2283                if (seen_dashdash) {
2284                        /* (2) */
2285                        if (seen_dashdash + 1 != argc - 1)
2286                                usage(blame_usage);
2287                        path = add_prefix(prefix, argv[seen_dashdash + 1]);
2288                        for (j = i; j < seen_dashdash; j++)
2289                                argv[unk++] = argv[j];
2290                }
2291                else {
2292                        /* (3) */
2293                        if (argc <= i)
2294                                usage(blame_usage);
2295                        path = add_prefix(prefix, argv[i]);
2296                        if (i + 1 == argc - 1) {
2297                                final_commit_name = argv[i + 1];
2298
2299                                /* if (unk == 1) we could be getting
2300                                 * old-style
2301                                 */
2302                                if (unk == 1 && !has_path_in_work_tree(path)) {
2303                                        path = add_prefix(prefix, argv[i + 1]);
2304                                        final_commit_name = argv[i];
2305                                }
2306                        }
2307                        else if (i != argc - 1)
2308                                usage(blame_usage); /* garbage at end */
2309
2310                        if (!has_path_in_work_tree(path))
2311                                die("cannot stat path %s: %s",
2312                                    path, strerror(errno));
2313                }
2314        }
2315
2316        if (final_commit_name)
2317                argv[unk++] = final_commit_name;
2318
2319        /*
2320         * Now we got rev and path.  We do not want the path pruning
2321         * but we may want "bottom" processing.
2322         */
2323        argv[unk++] = "--"; /* terminate the rev name */
2324        argv[unk] = NULL;
2325
2326        init_revisions(&revs, NULL);
2327        setup_revisions(unk, argv, &revs, NULL);
2328        memset(&sb, 0, sizeof(sb));
2329
2330        /*
2331         * There must be one and only one positive commit in the
2332         * revs->pending array.
2333         */
2334        for (i = 0; i < revs.pending.nr; i++) {
2335                struct object *obj = revs.pending.objects[i].item;
2336                if (obj->flags & UNINTERESTING)
2337                        continue;
2338                while (obj->type == OBJ_TAG)
2339                        obj = deref_tag(obj, NULL, 0);
2340                if (obj->type != OBJ_COMMIT)
2341                        die("Non commit %s?",
2342                            revs.pending.objects[i].name);
2343                if (sb.final)
2344                        die("More than one commit to dig from %s and %s?",
2345                            revs.pending.objects[i].name,
2346                            final_commit_name);
2347                sb.final = (struct commit *) obj;
2348                final_commit_name = revs.pending.objects[i].name;
2349        }
2350
2351        if (!sb.final) {
2352                /*
2353                 * "--not A B -- path" without anything positive;
2354                 * do not default to HEAD, but use the working tree
2355                 * or "--contents".
2356                 */
2357                sb.final = fake_working_tree_commit(path, contents_from);
2358                add_pending_object(&revs, &(sb.final->object), ":");
2359        }
2360        else if (contents_from)
2361                die("Cannot use --contents with final commit object name");
2362
2363        /*
2364         * If we have bottom, this will mark the ancestors of the
2365         * bottom commits we would reach while traversing as
2366         * uninteresting.
2367         */
2368        prepare_revision_walk(&revs);
2369
2370        if (is_null_sha1(sb.final->object.sha1)) {
2371                char *buf;
2372                o = sb.final->util;
2373                buf = xmalloc(o->file.size + 1);
2374                memcpy(buf, o->file.ptr, o->file.size + 1);
2375                sb.final_buf = buf;
2376                sb.final_buf_size = o->file.size;
2377        }
2378        else {
2379                o = get_origin(&sb, sb.final, path);
2380                if (fill_blob_sha1(o))
2381                        die("no such path %s in %s", path, final_commit_name);
2382
2383                sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2384                                              &sb.final_buf_size);
2385        }
2386        num_read_blob++;
2387        lno = prepare_lines(&sb);
2388
2389        bottom = top = 0;
2390        if (bottomtop)
2391                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2392        if (bottom && top && top < bottom) {
2393                long tmp;
2394                tmp = top; top = bottom; bottom = tmp;
2395        }
2396        if (bottom < 1)
2397                bottom = 1;
2398        if (top < 1)
2399                top = lno;
2400        bottom--;
2401        if (lno < top)
2402                die("file %s has only %lu lines", path, lno);
2403
2404        ent = xcalloc(1, sizeof(*ent));
2405        ent->lno = bottom;
2406        ent->num_lines = top - bottom;
2407        ent->suspect = o;
2408        ent->s_lno = bottom;
2409
2410        sb.ent = ent;
2411        sb.path = path;
2412
2413        if (revs_file && read_ancestry(revs_file))
2414                die("reading graft file %s failed: %s",
2415                    revs_file, strerror(errno));
2416
2417        read_mailmap(&mailmap, ".mailmap", NULL);
2418
2419        assign_blame(&sb, &revs, opt);
2420
2421        if (incremental)
2422                return 0;
2423
2424        coalesce(&sb);
2425
2426        if (!(output_option & OUTPUT_PORCELAIN))
2427                find_alignment(&sb, &output_option);
2428
2429        output(&sb, output_option);
2430        free((void *)sb.final_buf);
2431        for (ent = sb.ent; ent; ) {
2432                struct blame_entry *e = ent->next;
2433                free(ent);
2434                ent = e;
2435        }
2436
2437        if (show_stats) {
2438                printf("num read blob: %d\n", num_read_blob);
2439                printf("num get patch: %d\n", num_get_patch);
2440                printf("num commits: %d\n", num_commits);
2441        }
2442        return 0;
2443}