builtin-blame.con commit Merge branch 'maint' (e881192)
   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
  20static char blame_usage[] =
  21"git-blame [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [--contents <filename>] [--incremental] [commit] [--] file\n"
  22"  -c, --compatibility Use the same output mode as git-annotate (Default: off)\n"
  23"  -b                  Show blank SHA-1 for boundary commits (Default: off)\n"
  24"  -l, --long          Show long commit SHA1 (Default: off)\n"
  25"  --root              Do not treat root commits as boundaries (Default: off)\n"
  26"  -t, --time          Show raw timestamp (Default: off)\n"
  27"  -f, --show-name     Show original filename (Default: auto)\n"
  28"  -n, --show-number   Show original linenumber (Default: off)\n"
  29"  -p, --porcelain     Show in a format designed for machine consumption\n"
  30"  -L n,m              Process only line range n,m, counting from 1\n"
  31"  -M, -C              Find line movements within and across files\n"
  32"  --incremental       Show blame entries as we find them, incrementally\n"
  33"  --contents file     Use <file>'s contents as the final image\n"
  34"  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
  35
  36static int longest_file;
  37static int longest_author;
  38static int max_orig_digits;
  39static int max_digits;
  40static int max_score_digits;
  41static int show_root;
  42static int blank_boundary;
  43static int incremental;
  44static int cmd_is_annotate;
  45
  46#ifndef DEBUG
  47#define DEBUG 0
  48#endif
  49
  50/* stats */
  51static int num_read_blob;
  52static int num_get_patch;
  53static int num_commits;
  54
  55#define PICKAXE_BLAME_MOVE              01
  56#define PICKAXE_BLAME_COPY              02
  57#define PICKAXE_BLAME_COPY_HARDER       04
  58
  59/*
  60 * blame for a blame_entry with score lower than these thresholds
  61 * is not passed to the parent using move/copy logic.
  62 */
  63static unsigned blame_move_score;
  64static unsigned blame_copy_score;
  65#define BLAME_DEFAULT_MOVE_SCORE        20
  66#define BLAME_DEFAULT_COPY_SCORE        40
  67
  68/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  69#define METAINFO_SHOWN          (1u<<12)
  70#define MORE_THAN_ONE_PATH      (1u<<13)
  71
  72/*
  73 * One blob in a commit that is being suspected
  74 */
  75struct origin {
  76        int refcnt;
  77        struct commit *commit;
  78        mmfile_t file;
  79        unsigned char blob_sha1[20];
  80        char path[FLEX_ARRAY];
  81};
  82
  83/*
  84 * Given an origin, prepare mmfile_t structure to be used by the
  85 * diff machinery
  86 */
  87static char *fill_origin_blob(struct origin *o, mmfile_t *file)
  88{
  89        if (!o->file.ptr) {
  90                enum object_type type;
  91                num_read_blob++;
  92                file->ptr = read_sha1_file(o->blob_sha1, &type,
  93                                           (unsigned long *)(&(file->size)));
  94                o->file = *file;
  95        }
  96        else
  97                *file = o->file;
  98        return file->ptr;
  99}
 100
 101/*
 102 * Origin is refcounted and usually we keep the blob contents to be
 103 * reused.
 104 */
 105static inline struct origin *origin_incref(struct origin *o)
 106{
 107        if (o)
 108                o->refcnt++;
 109        return o;
 110}
 111
 112static void origin_decref(struct origin *o)
 113{
 114        if (o && --o->refcnt <= 0) {
 115                if (o->file.ptr)
 116                        free(o->file.ptr);
 117                memset(o, 0, sizeof(*o));
 118                free(o);
 119        }
 120}
 121
 122/*
 123 * Each group of lines is described by a blame_entry; it can be split
 124 * as we pass blame to the parents.  They form a linked list in the
 125 * scoreboard structure, sorted by the target line number.
 126 */
 127struct blame_entry {
 128        struct blame_entry *prev;
 129        struct blame_entry *next;
 130
 131        /* the first line of this group in the final image;
 132         * internally all line numbers are 0 based.
 133         */
 134        int lno;
 135
 136        /* how many lines this group has */
 137        int num_lines;
 138
 139        /* the commit that introduced this group into the final image */
 140        struct origin *suspect;
 141
 142        /* true if the suspect is truly guilty; false while we have not
 143         * checked if the group came from one of its parents.
 144         */
 145        char guilty;
 146
 147        /* the line number of the first line of this group in the
 148         * suspect's file; internally all line numbers are 0 based.
 149         */
 150        int s_lno;
 151
 152        /* how significant this entry is -- cached to avoid
 153         * scanning the lines over and over.
 154         */
 155        unsigned score;
 156};
 157
 158/*
 159 * The current state of the blame assignment.
 160 */
 161struct scoreboard {
 162        /* the final commit (i.e. where we started digging from) */
 163        struct commit *final;
 164
 165        const char *path;
 166
 167        /*
 168         * The contents in the final image.
 169         * Used by many functions to obtain contents of the nth line,
 170         * indexed with scoreboard.lineno[blame_entry.lno].
 171         */
 172        const char *final_buf;
 173        unsigned long final_buf_size;
 174
 175        /* linked list of blames */
 176        struct blame_entry *ent;
 177
 178        /* look-up a line in the final buffer */
 179        int num_lines;
 180        int *lineno;
 181};
 182
 183static inline int same_suspect(struct origin *a, struct origin *b)
 184{
 185        if (a == b)
 186                return 1;
 187        if (a->commit != b->commit)
 188                return 0;
 189        return !strcmp(a->path, b->path);
 190}
 191
 192static void sanity_check_refcnt(struct scoreboard *);
 193
 194/*
 195 * If two blame entries that are next to each other came from
 196 * contiguous lines in the same origin (i.e. <commit, path> pair),
 197 * merge them together.
 198 */
 199static void coalesce(struct scoreboard *sb)
 200{
 201        struct blame_entry *ent, *next;
 202
 203        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 204                if (same_suspect(ent->suspect, next->suspect) &&
 205                    ent->guilty == next->guilty &&
 206                    ent->s_lno + ent->num_lines == next->s_lno) {
 207                        ent->num_lines += next->num_lines;
 208                        ent->next = next->next;
 209                        if (ent->next)
 210                                ent->next->prev = ent;
 211                        origin_decref(next->suspect);
 212                        free(next);
 213                        ent->score = 0;
 214                        next = ent; /* again */
 215                }
 216        }
 217
 218        if (DEBUG) /* sanity */
 219                sanity_check_refcnt(sb);
 220}
 221
 222/*
 223 * Given a commit and a path in it, create a new origin structure.
 224 * The callers that add blame to the scoreboard should use
 225 * get_origin() to obtain shared, refcounted copy instead of calling
 226 * this function directly.
 227 */
 228static struct origin *make_origin(struct commit *commit, const char *path)
 229{
 230        struct origin *o;
 231        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 232        o->commit = commit;
 233        o->refcnt = 1;
 234        strcpy(o->path, path);
 235        return o;
 236}
 237
 238/*
 239 * Locate an existing origin or create a new one.
 240 */
 241static struct origin *get_origin(struct scoreboard *sb,
 242                                 struct commit *commit,
 243                                 const char *path)
 244{
 245        struct blame_entry *e;
 246
 247        for (e = sb->ent; e; e = e->next) {
 248                if (e->suspect->commit == commit &&
 249                    !strcmp(e->suspect->path, path))
 250                        return origin_incref(e->suspect);
 251        }
 252        return make_origin(commit, path);
 253}
 254
 255/*
 256 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 257 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 258 * for an origin is also used to pass the blame for the entire file to
 259 * the parent to detect the case where a child's blob is identical to
 260 * that of its parent's.
 261 */
 262static int fill_blob_sha1(struct origin *origin)
 263{
 264        unsigned mode;
 265
 266        if (!is_null_sha1(origin->blob_sha1))
 267                return 0;
 268        if (get_tree_entry(origin->commit->object.sha1,
 269                           origin->path,
 270                           origin->blob_sha1, &mode))
 271                goto error_out;
 272        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 273                goto error_out;
 274        return 0;
 275 error_out:
 276        hashclr(origin->blob_sha1);
 277        return -1;
 278}
 279
 280/*
 281 * We have an origin -- check if the same path exists in the
 282 * parent and return an origin structure to represent it.
 283 */
 284static struct origin *find_origin(struct scoreboard *sb,
 285                                  struct commit *parent,
 286                                  struct origin *origin)
 287{
 288        struct origin *porigin = NULL;
 289        struct diff_options diff_opts;
 290        const char *paths[2];
 291
 292        if (parent->util) {
 293                /*
 294                 * Each commit object can cache one origin in that
 295                 * commit.  This is a freestanding copy of origin and
 296                 * not refcounted.
 297                 */
 298                struct origin *cached = parent->util;
 299                if (!strcmp(cached->path, origin->path)) {
 300                        /*
 301                         * The same path between origin and its parent
 302                         * without renaming -- the most common case.
 303                         */
 304                        porigin = get_origin(sb, parent, cached->path);
 305
 306                        /*
 307                         * If the origin was newly created (i.e. get_origin
 308                         * would call make_origin if none is found in the
 309                         * scoreboard), it does not know the blob_sha1,
 310                         * so copy it.  Otherwise porigin was in the
 311                         * scoreboard and already knows blob_sha1.
 312                         */
 313                        if (porigin->refcnt == 1)
 314                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 315                        return porigin;
 316                }
 317                /* otherwise it was not very useful; free it */
 318                free(parent->util);
 319                parent->util = NULL;
 320        }
 321
 322        /* See if the origin->path is different between parent
 323         * and origin first.  Most of the time they are the
 324         * same and diff-tree is fairly efficient about this.
 325         */
 326        diff_setup(&diff_opts);
 327        diff_opts.recursive = 1;
 328        diff_opts.detect_rename = 0;
 329        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 330        paths[0] = origin->path;
 331        paths[1] = NULL;
 332
 333        diff_tree_setup_paths(paths, &diff_opts);
 334        if (diff_setup_done(&diff_opts) < 0)
 335                die("diff-setup");
 336
 337        if (is_null_sha1(origin->commit->object.sha1))
 338                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 339        else
 340                diff_tree_sha1(parent->tree->object.sha1,
 341                               origin->commit->tree->object.sha1,
 342                               "", &diff_opts);
 343        diffcore_std(&diff_opts);
 344
 345        /* It is either one entry that says "modified", or "created",
 346         * or nothing.
 347         */
 348        if (!diff_queued_diff.nr) {
 349                /* The path is the same as parent */
 350                porigin = get_origin(sb, parent, origin->path);
 351                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 352        }
 353        else if (diff_queued_diff.nr != 1)
 354                die("internal error in blame::find_origin");
 355        else {
 356                struct diff_filepair *p = diff_queued_diff.queue[0];
 357                switch (p->status) {
 358                default:
 359                        die("internal error in blame::find_origin (%c)",
 360                            p->status);
 361                case 'M':
 362                        porigin = get_origin(sb, parent, origin->path);
 363                        hashcpy(porigin->blob_sha1, p->one->sha1);
 364                        break;
 365                case 'A':
 366                case 'T':
 367                        /* Did not exist in parent, or type changed */
 368                        break;
 369                }
 370        }
 371        diff_flush(&diff_opts);
 372        if (porigin) {
 373                /*
 374                 * Create a freestanding copy that is not part of
 375                 * the refcounted origin found in the scoreboard, and
 376                 * cache it in the commit.
 377                 */
 378                struct origin *cached;
 379
 380                cached = make_origin(porigin->commit, porigin->path);
 381                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 382                parent->util = cached;
 383        }
 384        return porigin;
 385}
 386
 387/*
 388 * We have an origin -- find the path that corresponds to it in its
 389 * parent and return an origin structure to represent it.
 390 */
 391static struct origin *find_rename(struct scoreboard *sb,
 392                                  struct commit *parent,
 393                                  struct origin *origin)
 394{
 395        struct origin *porigin = NULL;
 396        struct diff_options diff_opts;
 397        int i;
 398        const char *paths[2];
 399
 400        diff_setup(&diff_opts);
 401        diff_opts.recursive = 1;
 402        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 403        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 404        diff_opts.single_follow = origin->path;
 405        paths[0] = NULL;
 406        diff_tree_setup_paths(paths, &diff_opts);
 407        if (diff_setup_done(&diff_opts) < 0)
 408                die("diff-setup");
 409
 410        if (is_null_sha1(origin->commit->object.sha1))
 411                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 412        else
 413                diff_tree_sha1(parent->tree->object.sha1,
 414                               origin->commit->tree->object.sha1,
 415                               "", &diff_opts);
 416        diffcore_std(&diff_opts);
 417
 418        for (i = 0; i < diff_queued_diff.nr; i++) {
 419                struct diff_filepair *p = diff_queued_diff.queue[i];
 420                if ((p->status == 'R' || p->status == 'C') &&
 421                    !strcmp(p->two->path, origin->path)) {
 422                        porigin = get_origin(sb, parent, p->one->path);
 423                        hashcpy(porigin->blob_sha1, p->one->sha1);
 424                        break;
 425                }
 426        }
 427        diff_flush(&diff_opts);
 428        return porigin;
 429}
 430
 431/*
 432 * Parsing of patch chunks...
 433 */
 434struct chunk {
 435        /* line number in postimage; up to but not including this
 436         * line is the same as preimage
 437         */
 438        int same;
 439
 440        /* preimage line number after this chunk */
 441        int p_next;
 442
 443        /* postimage line number after this chunk */
 444        int t_next;
 445};
 446
 447struct patch {
 448        struct chunk *chunks;
 449        int num;
 450};
 451
 452struct blame_diff_state {
 453        struct xdiff_emit_state xm;
 454        struct patch *ret;
 455        unsigned hunk_post_context;
 456        unsigned hunk_in_pre_context : 1;
 457};
 458
 459static void process_u_diff(void *state_, char *line, unsigned long len)
 460{
 461        struct blame_diff_state *state = state_;
 462        struct chunk *chunk;
 463        int off1, off2, len1, len2, num;
 464
 465        num = state->ret->num;
 466        if (len < 4 || line[0] != '@' || line[1] != '@') {
 467                if (state->hunk_in_pre_context && line[0] == ' ')
 468                        state->ret->chunks[num - 1].same++;
 469                else {
 470                        state->hunk_in_pre_context = 0;
 471                        if (line[0] == ' ')
 472                                state->hunk_post_context++;
 473                        else
 474                                state->hunk_post_context = 0;
 475                }
 476                return;
 477        }
 478
 479        if (num && state->hunk_post_context) {
 480                chunk = &state->ret->chunks[num - 1];
 481                chunk->p_next -= state->hunk_post_context;
 482                chunk->t_next -= state->hunk_post_context;
 483        }
 484        state->ret->num = ++num;
 485        state->ret->chunks = xrealloc(state->ret->chunks,
 486                                      sizeof(struct chunk) * num);
 487        chunk = &state->ret->chunks[num - 1];
 488        if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
 489                state->ret->num--;
 490                return;
 491        }
 492
 493        /* Line numbers in patch output are one based. */
 494        off1--;
 495        off2--;
 496
 497        chunk->same = len2 ? off2 : (off2 + 1);
 498
 499        chunk->p_next = off1 + (len1 ? len1 : 1);
 500        chunk->t_next = chunk->same + len2;
 501        state->hunk_in_pre_context = 1;
 502        state->hunk_post_context = 0;
 503}
 504
 505static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
 506                                    int context)
 507{
 508        struct blame_diff_state state;
 509        xpparam_t xpp;
 510        xdemitconf_t xecfg;
 511        xdemitcb_t ecb;
 512
 513        xpp.flags = XDF_NEED_MINIMAL;
 514        xecfg.ctxlen = context;
 515        xecfg.flags = 0;
 516        ecb.outf = xdiff_outf;
 517        ecb.priv = &state;
 518        memset(&state, 0, sizeof(state));
 519        state.xm.consume = process_u_diff;
 520        state.ret = xmalloc(sizeof(struct patch));
 521        state.ret->chunks = NULL;
 522        state.ret->num = 0;
 523
 524        xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
 525
 526        if (state.ret->num) {
 527                struct chunk *chunk;
 528                chunk = &state.ret->chunks[state.ret->num - 1];
 529                chunk->p_next -= state.hunk_post_context;
 530                chunk->t_next -= state.hunk_post_context;
 531        }
 532        return state.ret;
 533}
 534
 535/*
 536 * Run diff between two origins and grab the patch output, so that
 537 * we can pass blame for lines origin is currently suspected for
 538 * to its parent.
 539 */
 540static struct patch *get_patch(struct origin *parent, struct origin *origin)
 541{
 542        mmfile_t file_p, file_o;
 543        struct patch *patch;
 544
 545        fill_origin_blob(parent, &file_p);
 546        fill_origin_blob(origin, &file_o);
 547        if (!file_p.ptr || !file_o.ptr)
 548                return NULL;
 549        patch = compare_buffer(&file_p, &file_o, 0);
 550        num_get_patch++;
 551        return patch;
 552}
 553
 554static void free_patch(struct patch *p)
 555{
 556        free(p->chunks);
 557        free(p);
 558}
 559
 560/*
 561 * Link in a new blame entry to the scoreboard.  Entries that cover the
 562 * same line range have been removed from the scoreboard previously.
 563 */
 564static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 565{
 566        struct blame_entry *ent, *prev = NULL;
 567
 568        origin_incref(e->suspect);
 569
 570        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 571                prev = ent;
 572
 573        /* prev, if not NULL, is the last one that is below e */
 574        e->prev = prev;
 575        if (prev) {
 576                e->next = prev->next;
 577                prev->next = e;
 578        }
 579        else {
 580                e->next = sb->ent;
 581                sb->ent = e;
 582        }
 583        if (e->next)
 584                e->next->prev = e;
 585}
 586
 587/*
 588 * src typically is on-stack; we want to copy the information in it to
 589 * an malloced blame_entry that is already on the linked list of the
 590 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 591 * gains one.
 592 */
 593static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 594{
 595        struct blame_entry *p, *n;
 596
 597        p = dst->prev;
 598        n = dst->next;
 599        origin_incref(src->suspect);
 600        origin_decref(dst->suspect);
 601        memcpy(dst, src, sizeof(*src));
 602        dst->prev = p;
 603        dst->next = n;
 604        dst->score = 0;
 605}
 606
 607static const char *nth_line(struct scoreboard *sb, int lno)
 608{
 609        return sb->final_buf + sb->lineno[lno];
 610}
 611
 612/*
 613 * It is known that lines between tlno to same came from parent, and e
 614 * has an overlap with that range.  it also is known that parent's
 615 * line plno corresponds to e's line tlno.
 616 *
 617 *                <---- e ----->
 618 *                   <------>
 619 *                   <------------>
 620 *             <------------>
 621 *             <------------------>
 622 *
 623 * Split e into potentially three parts; before this chunk, the chunk
 624 * to be blamed for the parent, and after that portion.
 625 */
 626static void split_overlap(struct blame_entry *split,
 627                          struct blame_entry *e,
 628                          int tlno, int plno, int same,
 629                          struct origin *parent)
 630{
 631        int chunk_end_lno;
 632        memset(split, 0, sizeof(struct blame_entry [3]));
 633
 634        if (e->s_lno < tlno) {
 635                /* there is a pre-chunk part not blamed on parent */
 636                split[0].suspect = origin_incref(e->suspect);
 637                split[0].lno = e->lno;
 638                split[0].s_lno = e->s_lno;
 639                split[0].num_lines = tlno - e->s_lno;
 640                split[1].lno = e->lno + tlno - e->s_lno;
 641                split[1].s_lno = plno;
 642        }
 643        else {
 644                split[1].lno = e->lno;
 645                split[1].s_lno = plno + (e->s_lno - tlno);
 646        }
 647
 648        if (same < e->s_lno + e->num_lines) {
 649                /* there is a post-chunk part not blamed on parent */
 650                split[2].suspect = origin_incref(e->suspect);
 651                split[2].lno = e->lno + (same - e->s_lno);
 652                split[2].s_lno = e->s_lno + (same - e->s_lno);
 653                split[2].num_lines = e->s_lno + e->num_lines - same;
 654                chunk_end_lno = split[2].lno;
 655        }
 656        else
 657                chunk_end_lno = e->lno + e->num_lines;
 658        split[1].num_lines = chunk_end_lno - split[1].lno;
 659
 660        /*
 661         * if it turns out there is nothing to blame the parent for,
 662         * forget about the splitting.  !split[1].suspect signals this.
 663         */
 664        if (split[1].num_lines < 1)
 665                return;
 666        split[1].suspect = origin_incref(parent);
 667}
 668
 669/*
 670 * split_overlap() divided an existing blame e into up to three parts
 671 * in split.  Adjust the linked list of blames in the scoreboard to
 672 * reflect the split.
 673 */
 674static void split_blame(struct scoreboard *sb,
 675                        struct blame_entry *split,
 676                        struct blame_entry *e)
 677{
 678        struct blame_entry *new_entry;
 679
 680        if (split[0].suspect && split[2].suspect) {
 681                /* The first part (reuse storage for the existing entry e) */
 682                dup_entry(e, &split[0]);
 683
 684                /* The last part -- me */
 685                new_entry = xmalloc(sizeof(*new_entry));
 686                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 687                add_blame_entry(sb, new_entry);
 688
 689                /* ... and the middle part -- parent */
 690                new_entry = xmalloc(sizeof(*new_entry));
 691                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 692                add_blame_entry(sb, new_entry);
 693        }
 694        else if (!split[0].suspect && !split[2].suspect)
 695                /*
 696                 * The parent covers the entire area; reuse storage for
 697                 * e and replace it with the parent.
 698                 */
 699                dup_entry(e, &split[1]);
 700        else if (split[0].suspect) {
 701                /* me and then parent */
 702                dup_entry(e, &split[0]);
 703
 704                new_entry = xmalloc(sizeof(*new_entry));
 705                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 706                add_blame_entry(sb, new_entry);
 707        }
 708        else {
 709                /* parent and then me */
 710                dup_entry(e, &split[1]);
 711
 712                new_entry = xmalloc(sizeof(*new_entry));
 713                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 714                add_blame_entry(sb, new_entry);
 715        }
 716
 717        if (DEBUG) { /* sanity */
 718                struct blame_entry *ent;
 719                int lno = sb->ent->lno, corrupt = 0;
 720
 721                for (ent = sb->ent; ent; ent = ent->next) {
 722                        if (lno != ent->lno)
 723                                corrupt = 1;
 724                        if (ent->s_lno < 0)
 725                                corrupt = 1;
 726                        lno += ent->num_lines;
 727                }
 728                if (corrupt) {
 729                        lno = sb->ent->lno;
 730                        for (ent = sb->ent; ent; ent = ent->next) {
 731                                printf("L %8d l %8d n %8d\n",
 732                                       lno, ent->lno, ent->num_lines);
 733                                lno = ent->lno + ent->num_lines;
 734                        }
 735                        die("oops");
 736                }
 737        }
 738}
 739
 740/*
 741 * After splitting the blame, the origins used by the
 742 * on-stack blame_entry should lose one refcnt each.
 743 */
 744static void decref_split(struct blame_entry *split)
 745{
 746        int i;
 747
 748        for (i = 0; i < 3; i++)
 749                origin_decref(split[i].suspect);
 750}
 751
 752/*
 753 * Helper for blame_chunk().  blame_entry e is known to overlap with
 754 * the patch hunk; split it and pass blame to the parent.
 755 */
 756static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 757                          int tlno, int plno, int same,
 758                          struct origin *parent)
 759{
 760        struct blame_entry split[3];
 761
 762        split_overlap(split, e, tlno, plno, same, parent);
 763        if (split[1].suspect)
 764                split_blame(sb, split, e);
 765        decref_split(split);
 766}
 767
 768/*
 769 * Find the line number of the last line the target is suspected for.
 770 */
 771static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 772{
 773        struct blame_entry *e;
 774        int last_in_target = -1;
 775
 776        for (e = sb->ent; e; e = e->next) {
 777                if (e->guilty || !same_suspect(e->suspect, target))
 778                        continue;
 779                if (last_in_target < e->s_lno + e->num_lines)
 780                        last_in_target = e->s_lno + e->num_lines;
 781        }
 782        return last_in_target;
 783}
 784
 785/*
 786 * Process one hunk from the patch between the current suspect for
 787 * blame_entry e and its parent.  Find and split the overlap, and
 788 * pass blame to the overlapping part to the parent.
 789 */
 790static void blame_chunk(struct scoreboard *sb,
 791                        int tlno, int plno, int same,
 792                        struct origin *target, struct origin *parent)
 793{
 794        struct blame_entry *e;
 795
 796        for (e = sb->ent; e; e = e->next) {
 797                if (e->guilty || !same_suspect(e->suspect, target))
 798                        continue;
 799                if (same <= e->s_lno)
 800                        continue;
 801                if (tlno < e->s_lno + e->num_lines)
 802                        blame_overlap(sb, e, tlno, plno, same, parent);
 803        }
 804}
 805
 806/*
 807 * We are looking at the origin 'target' and aiming to pass blame
 808 * for the lines it is suspected to its parent.  Run diff to find
 809 * which lines came from parent and pass blame for them.
 810 */
 811static int pass_blame_to_parent(struct scoreboard *sb,
 812                                struct origin *target,
 813                                struct origin *parent)
 814{
 815        int i, last_in_target, plno, tlno;
 816        struct patch *patch;
 817
 818        last_in_target = find_last_in_target(sb, target);
 819        if (last_in_target < 0)
 820                return 1; /* nothing remains for this target */
 821
 822        patch = get_patch(parent, target);
 823        plno = tlno = 0;
 824        for (i = 0; i < patch->num; i++) {
 825                struct chunk *chunk = &patch->chunks[i];
 826
 827                blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 828                plno = chunk->p_next;
 829                tlno = chunk->t_next;
 830        }
 831        /* The rest (i.e. anything after tlno) are the same as the parent */
 832        blame_chunk(sb, tlno, plno, last_in_target, target, parent);
 833
 834        free_patch(patch);
 835        return 0;
 836}
 837
 838/*
 839 * The lines in blame_entry after splitting blames many times can become
 840 * very small and trivial, and at some point it becomes pointless to
 841 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 842 * ordinary C program, and it is not worth to say it was copied from
 843 * totally unrelated file in the parent.
 844 *
 845 * Compute how trivial the lines in the blame_entry are.
 846 */
 847static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 848{
 849        unsigned score;
 850        const char *cp, *ep;
 851
 852        if (e->score)
 853                return e->score;
 854
 855        score = 1;
 856        cp = nth_line(sb, e->lno);
 857        ep = nth_line(sb, e->lno + e->num_lines);
 858        while (cp < ep) {
 859                unsigned ch = *((unsigned char *)cp);
 860                if (isalnum(ch))
 861                        score++;
 862                cp++;
 863        }
 864        e->score = score;
 865        return score;
 866}
 867
 868/*
 869 * best_so_far[] and this[] are both a split of an existing blame_entry
 870 * that passes blame to the parent.  Maintain best_so_far the best split
 871 * so far, by comparing this and best_so_far and copying this into
 872 * bst_so_far as needed.
 873 */
 874static void copy_split_if_better(struct scoreboard *sb,
 875                                 struct blame_entry *best_so_far,
 876                                 struct blame_entry *this)
 877{
 878        int i;
 879
 880        if (!this[1].suspect)
 881                return;
 882        if (best_so_far[1].suspect) {
 883                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 884                        return;
 885        }
 886
 887        for (i = 0; i < 3; i++)
 888                origin_incref(this[i].suspect);
 889        decref_split(best_so_far);
 890        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 891}
 892
 893/*
 894 * Find the lines from parent that are the same as ent so that
 895 * we can pass blames to it.  file_p has the blob contents for
 896 * the parent.
 897 */
 898static void find_copy_in_blob(struct scoreboard *sb,
 899                              struct blame_entry *ent,
 900                              struct origin *parent,
 901                              struct blame_entry *split,
 902                              mmfile_t *file_p)
 903{
 904        const char *cp;
 905        int cnt;
 906        mmfile_t file_o;
 907        struct patch *patch;
 908        int i, plno, tlno;
 909
 910        /*
 911         * Prepare mmfile that contains only the lines in ent.
 912         */
 913        cp = nth_line(sb, ent->lno);
 914        file_o.ptr = (char*) cp;
 915        cnt = ent->num_lines;
 916
 917        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 918                if (*cp++ == '\n')
 919                        cnt--;
 920        }
 921        file_o.size = cp - file_o.ptr;
 922
 923        patch = compare_buffer(file_p, &file_o, 1);
 924
 925        memset(split, 0, sizeof(struct blame_entry [3]));
 926        plno = tlno = 0;
 927        for (i = 0; i < patch->num; i++) {
 928                struct chunk *chunk = &patch->chunks[i];
 929
 930                /* tlno to chunk->same are the same as ent */
 931                if (ent->num_lines <= tlno)
 932                        break;
 933                if (tlno < chunk->same) {
 934                        struct blame_entry this[3];
 935                        split_overlap(this, ent,
 936                                      tlno + ent->s_lno, plno,
 937                                      chunk->same + ent->s_lno,
 938                                      parent);
 939                        copy_split_if_better(sb, split, this);
 940                        decref_split(this);
 941                }
 942                plno = chunk->p_next;
 943                tlno = chunk->t_next;
 944        }
 945        free_patch(patch);
 946}
 947
 948/*
 949 * See if lines currently target is suspected for can be attributed to
 950 * parent.
 951 */
 952static int find_move_in_parent(struct scoreboard *sb,
 953                               struct origin *target,
 954                               struct origin *parent)
 955{
 956        int last_in_target, made_progress;
 957        struct blame_entry *e, split[3];
 958        mmfile_t file_p;
 959
 960        last_in_target = find_last_in_target(sb, target);
 961        if (last_in_target < 0)
 962                return 1; /* nothing remains for this target */
 963
 964        fill_origin_blob(parent, &file_p);
 965        if (!file_p.ptr)
 966                return 0;
 967
 968        made_progress = 1;
 969        while (made_progress) {
 970                made_progress = 0;
 971                for (e = sb->ent; e; e = e->next) {
 972                        if (e->guilty || !same_suspect(e->suspect, target))
 973                                continue;
 974                        find_copy_in_blob(sb, e, parent, split, &file_p);
 975                        if (split[1].suspect &&
 976                            blame_move_score < ent_score(sb, &split[1])) {
 977                                split_blame(sb, split, e);
 978                                made_progress = 1;
 979                        }
 980                        decref_split(split);
 981                }
 982        }
 983        return 0;
 984}
 985
 986struct blame_list {
 987        struct blame_entry *ent;
 988        struct blame_entry split[3];
 989};
 990
 991/*
 992 * Count the number of entries the target is suspected for,
 993 * and prepare a list of entry and the best split.
 994 */
 995static struct blame_list *setup_blame_list(struct scoreboard *sb,
 996                                           struct origin *target,
 997                                           int *num_ents_p)
 998{
 999        struct blame_entry *e;
1000        int num_ents, i;
1001        struct blame_list *blame_list = NULL;
1002
1003        for (e = sb->ent, num_ents = 0; e; e = e->next)
1004                if (!e->guilty && same_suspect(e->suspect, target))
1005                        num_ents++;
1006        if (num_ents) {
1007                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1008                for (e = sb->ent, i = 0; e; e = e->next)
1009                        if (!e->guilty && same_suspect(e->suspect, target))
1010                                blame_list[i++].ent = e;
1011        }
1012        *num_ents_p = num_ents;
1013        return blame_list;
1014}
1015
1016/*
1017 * For lines target is suspected for, see if we can find code movement
1018 * across file boundary from the parent commit.  porigin is the path
1019 * in the parent we already tried.
1020 */
1021static int find_copy_in_parent(struct scoreboard *sb,
1022                               struct origin *target,
1023                               struct commit *parent,
1024                               struct origin *porigin,
1025                               int opt)
1026{
1027        struct diff_options diff_opts;
1028        const char *paths[1];
1029        int i, j;
1030        int retval;
1031        struct blame_list *blame_list;
1032        int num_ents;
1033
1034        blame_list = setup_blame_list(sb, target, &num_ents);
1035        if (!blame_list)
1036                return 1; /* nothing remains for this target */
1037
1038        diff_setup(&diff_opts);
1039        diff_opts.recursive = 1;
1040        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1041
1042        paths[0] = NULL;
1043        diff_tree_setup_paths(paths, &diff_opts);
1044        if (diff_setup_done(&diff_opts) < 0)
1045                die("diff-setup");
1046
1047        /* Try "find copies harder" on new path if requested;
1048         * we do not want to use diffcore_rename() actually to
1049         * match things up; find_copies_harder is set only to
1050         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1051         * and this code needs to be after diff_setup_done(), which
1052         * usually makes find-copies-harder imply copy detection.
1053         */
1054        if ((opt & PICKAXE_BLAME_COPY_HARDER) &&
1055            (!porigin || strcmp(target->path, porigin->path)))
1056                diff_opts.find_copies_harder = 1;
1057
1058        if (is_null_sha1(target->commit->object.sha1))
1059                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1060        else
1061                diff_tree_sha1(parent->tree->object.sha1,
1062                               target->commit->tree->object.sha1,
1063                               "", &diff_opts);
1064
1065        if (!diff_opts.find_copies_harder)
1066                diffcore_std(&diff_opts);
1067
1068        retval = 0;
1069        while (1) {
1070                int made_progress = 0;
1071
1072                for (i = 0; i < diff_queued_diff.nr; i++) {
1073                        struct diff_filepair *p = diff_queued_diff.queue[i];
1074                        struct origin *norigin;
1075                        mmfile_t file_p;
1076                        struct blame_entry this[3];
1077
1078                        if (!DIFF_FILE_VALID(p->one))
1079                                continue; /* does not exist in parent */
1080                        if (porigin && !strcmp(p->one->path, porigin->path))
1081                                /* find_move already dealt with this path */
1082                                continue;
1083
1084                        norigin = get_origin(sb, parent, p->one->path);
1085                        hashcpy(norigin->blob_sha1, p->one->sha1);
1086                        fill_origin_blob(norigin, &file_p);
1087                        if (!file_p.ptr)
1088                                continue;
1089
1090                        for (j = 0; j < num_ents; j++) {
1091                                find_copy_in_blob(sb, blame_list[j].ent,
1092                                                  norigin, this, &file_p);
1093                                copy_split_if_better(sb, blame_list[j].split,
1094                                                     this);
1095                                decref_split(this);
1096                        }
1097                        origin_decref(norigin);
1098                }
1099
1100                for (j = 0; j < num_ents; j++) {
1101                        struct blame_entry *split = blame_list[j].split;
1102                        if (split[1].suspect &&
1103                            blame_copy_score < ent_score(sb, &split[1])) {
1104                                split_blame(sb, split, blame_list[j].ent);
1105                                made_progress = 1;
1106                        }
1107                        decref_split(split);
1108                }
1109                free(blame_list);
1110
1111                if (!made_progress)
1112                        break;
1113                blame_list = setup_blame_list(sb, target, &num_ents);
1114                if (!blame_list) {
1115                        retval = 1;
1116                        break;
1117                }
1118        }
1119        diff_flush(&diff_opts);
1120
1121        return retval;
1122}
1123
1124/*
1125 * The blobs of origin and porigin exactly match, so everything
1126 * origin is suspected for can be blamed on the parent.
1127 */
1128static void pass_whole_blame(struct scoreboard *sb,
1129                             struct origin *origin, struct origin *porigin)
1130{
1131        struct blame_entry *e;
1132
1133        if (!porigin->file.ptr && origin->file.ptr) {
1134                /* Steal its file */
1135                porigin->file = origin->file;
1136                origin->file.ptr = NULL;
1137        }
1138        for (e = sb->ent; e; e = e->next) {
1139                if (!same_suspect(e->suspect, origin))
1140                        continue;
1141                origin_incref(porigin);
1142                origin_decref(e->suspect);
1143                e->suspect = porigin;
1144        }
1145}
1146
1147#define MAXPARENT 16
1148
1149static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1150{
1151        int i, pass;
1152        struct commit *commit = origin->commit;
1153        struct commit_list *parent;
1154        struct origin *parent_origin[MAXPARENT], *porigin;
1155
1156        memset(parent_origin, 0, sizeof(parent_origin));
1157
1158        /* The first pass looks for unrenamed path to optimize for
1159         * common cases, then we look for renames in the second pass.
1160         */
1161        for (pass = 0; pass < 2; pass++) {
1162                struct origin *(*find)(struct scoreboard *,
1163                                       struct commit *, struct origin *);
1164                find = pass ? find_rename : find_origin;
1165
1166                for (i = 0, parent = commit->parents;
1167                     i < MAXPARENT && parent;
1168                     parent = parent->next, i++) {
1169                        struct commit *p = parent->item;
1170                        int j, same;
1171
1172                        if (parent_origin[i])
1173                                continue;
1174                        if (parse_commit(p))
1175                                continue;
1176                        porigin = find(sb, p, origin);
1177                        if (!porigin)
1178                                continue;
1179                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1180                                pass_whole_blame(sb, origin, porigin);
1181                                origin_decref(porigin);
1182                                goto finish;
1183                        }
1184                        for (j = same = 0; j < i; j++)
1185                                if (parent_origin[j] &&
1186                                    !hashcmp(parent_origin[j]->blob_sha1,
1187                                             porigin->blob_sha1)) {
1188                                        same = 1;
1189                                        break;
1190                                }
1191                        if (!same)
1192                                parent_origin[i] = porigin;
1193                        else
1194                                origin_decref(porigin);
1195                }
1196        }
1197
1198        num_commits++;
1199        for (i = 0, parent = commit->parents;
1200             i < MAXPARENT && parent;
1201             parent = parent->next, i++) {
1202                struct origin *porigin = parent_origin[i];
1203                if (!porigin)
1204                        continue;
1205                if (pass_blame_to_parent(sb, origin, porigin))
1206                        goto finish;
1207        }
1208
1209        /*
1210         * Optionally find moves in parents' files.
1211         */
1212        if (opt & PICKAXE_BLAME_MOVE)
1213                for (i = 0, parent = commit->parents;
1214                     i < MAXPARENT && parent;
1215                     parent = parent->next, i++) {
1216                        struct origin *porigin = parent_origin[i];
1217                        if (!porigin)
1218                                continue;
1219                        if (find_move_in_parent(sb, origin, porigin))
1220                                goto finish;
1221                }
1222
1223        /*
1224         * Optionally find copies from parents' files.
1225         */
1226        if (opt & PICKAXE_BLAME_COPY)
1227                for (i = 0, parent = commit->parents;
1228                     i < MAXPARENT && parent;
1229                     parent = parent->next, i++) {
1230                        struct origin *porigin = parent_origin[i];
1231                        if (find_copy_in_parent(sb, origin, parent->item,
1232                                                porigin, opt))
1233                                goto finish;
1234                }
1235
1236 finish:
1237        for (i = 0; i < MAXPARENT; i++)
1238                origin_decref(parent_origin[i]);
1239}
1240
1241/*
1242 * Information on commits, used for output.
1243 */
1244struct commit_info
1245{
1246        const char *author;
1247        const char *author_mail;
1248        unsigned long author_time;
1249        const char *author_tz;
1250
1251        /* filled only when asked for details */
1252        const char *committer;
1253        const char *committer_mail;
1254        unsigned long committer_time;
1255        const char *committer_tz;
1256
1257        const char *summary;
1258};
1259
1260/*
1261 * Parse author/committer line in the commit object buffer
1262 */
1263static void get_ac_line(const char *inbuf, const char *what,
1264                        int bufsz, char *person, const char **mail,
1265                        unsigned long *time, const char **tz)
1266{
1267        int len;
1268        char *tmp, *endp;
1269
1270        tmp = strstr(inbuf, what);
1271        if (!tmp)
1272                goto error_out;
1273        tmp += strlen(what);
1274        endp = strchr(tmp, '\n');
1275        if (!endp)
1276                len = strlen(tmp);
1277        else
1278                len = endp - tmp;
1279        if (bufsz <= len) {
1280        error_out:
1281                /* Ugh */
1282                *mail = *tz = "(unknown)";
1283                *time = 0;
1284                return;
1285        }
1286        memcpy(person, tmp, len);
1287
1288        tmp = person;
1289        tmp += len;
1290        *tmp = 0;
1291        while (*tmp != ' ')
1292                tmp--;
1293        *tz = tmp+1;
1294
1295        *tmp = 0;
1296        while (*tmp != ' ')
1297                tmp--;
1298        *time = strtoul(tmp, NULL, 10);
1299
1300        *tmp = 0;
1301        while (*tmp != ' ')
1302                tmp--;
1303        *mail = tmp + 1;
1304        *tmp = 0;
1305}
1306
1307static void get_commit_info(struct commit *commit,
1308                            struct commit_info *ret,
1309                            int detailed)
1310{
1311        int len;
1312        char *tmp, *endp;
1313        static char author_buf[1024];
1314        static char committer_buf[1024];
1315        static char summary_buf[1024];
1316
1317        /*
1318         * We've operated without save_commit_buffer, so
1319         * we now need to populate them for output.
1320         */
1321        if (!commit->buffer) {
1322                enum object_type type;
1323                unsigned long size;
1324                commit->buffer =
1325                        read_sha1_file(commit->object.sha1, &type, &size);
1326        }
1327        ret->author = author_buf;
1328        get_ac_line(commit->buffer, "\nauthor ",
1329                    sizeof(author_buf), author_buf, &ret->author_mail,
1330                    &ret->author_time, &ret->author_tz);
1331
1332        if (!detailed)
1333                return;
1334
1335        ret->committer = committer_buf;
1336        get_ac_line(commit->buffer, "\ncommitter ",
1337                    sizeof(committer_buf), committer_buf, &ret->committer_mail,
1338                    &ret->committer_time, &ret->committer_tz);
1339
1340        ret->summary = summary_buf;
1341        tmp = strstr(commit->buffer, "\n\n");
1342        if (!tmp) {
1343        error_out:
1344                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1345                return;
1346        }
1347        tmp += 2;
1348        endp = strchr(tmp, '\n');
1349        if (!endp)
1350                endp = tmp + strlen(tmp);
1351        len = endp - tmp;
1352        if (len >= sizeof(summary_buf) || len == 0)
1353                goto error_out;
1354        memcpy(summary_buf, tmp, len);
1355        summary_buf[len] = 0;
1356}
1357
1358/*
1359 * To allow LF and other nonportable characters in pathnames,
1360 * they are c-style quoted as needed.
1361 */
1362static void write_filename_info(const char *path)
1363{
1364        printf("filename ");
1365        write_name_quoted(NULL, 0, path, 1, stdout);
1366        putchar('\n');
1367}
1368
1369/*
1370 * The blame_entry is found to be guilty for the range.  Mark it
1371 * as such, and show it in incremental output.
1372 */
1373static void found_guilty_entry(struct blame_entry *ent)
1374{
1375        if (ent->guilty)
1376                return;
1377        ent->guilty = 1;
1378        if (incremental) {
1379                struct origin *suspect = ent->suspect;
1380
1381                printf("%s %d %d %d\n",
1382                       sha1_to_hex(suspect->commit->object.sha1),
1383                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1384                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1385                        struct commit_info ci;
1386                        suspect->commit->object.flags |= METAINFO_SHOWN;
1387                        get_commit_info(suspect->commit, &ci, 1);
1388                        printf("author %s\n", ci.author);
1389                        printf("author-mail %s\n", ci.author_mail);
1390                        printf("author-time %lu\n", ci.author_time);
1391                        printf("author-tz %s\n", ci.author_tz);
1392                        printf("committer %s\n", ci.committer);
1393                        printf("committer-mail %s\n", ci.committer_mail);
1394                        printf("committer-time %lu\n", ci.committer_time);
1395                        printf("committer-tz %s\n", ci.committer_tz);
1396                        printf("summary %s\n", ci.summary);
1397                        if (suspect->commit->object.flags & UNINTERESTING)
1398                                printf("boundary\n");
1399                }
1400                write_filename_info(suspect->path);
1401        }
1402}
1403
1404/*
1405 * The main loop -- while the scoreboard has lines whose true origin
1406 * is still unknown, pick one blame_entry, and allow its current
1407 * suspect to pass blames to its parents.
1408 */
1409static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1410{
1411        while (1) {
1412                struct blame_entry *ent;
1413                struct commit *commit;
1414                struct origin *suspect = NULL;
1415
1416                /* find one suspect to break down */
1417                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1418                        if (!ent->guilty)
1419                                suspect = ent->suspect;
1420                if (!suspect)
1421                        return; /* all done */
1422
1423                /*
1424                 * We will use this suspect later in the loop,
1425                 * so hold onto it in the meantime.
1426                 */
1427                origin_incref(suspect);
1428                commit = suspect->commit;
1429                if (!commit->object.parsed)
1430                        parse_commit(commit);
1431                if (!(commit->object.flags & UNINTERESTING) &&
1432                    !(revs->max_age != -1 && commit->date < revs->max_age))
1433                        pass_blame(sb, suspect, opt);
1434                else {
1435                        commit->object.flags |= UNINTERESTING;
1436                        if (commit->object.parsed)
1437                                mark_parents_uninteresting(commit);
1438                }
1439                /* treat root commit as boundary */
1440                if (!commit->parents && !show_root)
1441                        commit->object.flags |= UNINTERESTING;
1442
1443                /* Take responsibility for the remaining entries */
1444                for (ent = sb->ent; ent; ent = ent->next)
1445                        if (same_suspect(ent->suspect, suspect))
1446                                found_guilty_entry(ent);
1447                origin_decref(suspect);
1448
1449                if (DEBUG) /* sanity */
1450                        sanity_check_refcnt(sb);
1451        }
1452}
1453
1454static const char *format_time(unsigned long time, const char *tz_str,
1455                               int show_raw_time)
1456{
1457        static char time_buf[128];
1458        time_t t = time;
1459        int minutes, tz;
1460        struct tm *tm;
1461
1462        if (show_raw_time) {
1463                sprintf(time_buf, "%lu %s", time, tz_str);
1464                return time_buf;
1465        }
1466
1467        tz = atoi(tz_str);
1468        minutes = tz < 0 ? -tz : tz;
1469        minutes = (minutes / 100)*60 + (minutes % 100);
1470        minutes = tz < 0 ? -minutes : minutes;
1471        t = time + minutes * 60;
1472        tm = gmtime(&t);
1473
1474        strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1475        strcat(time_buf, tz_str);
1476        return time_buf;
1477}
1478
1479#define OUTPUT_ANNOTATE_COMPAT  001
1480#define OUTPUT_LONG_OBJECT_NAME 002
1481#define OUTPUT_RAW_TIMESTAMP    004
1482#define OUTPUT_PORCELAIN        010
1483#define OUTPUT_SHOW_NAME        020
1484#define OUTPUT_SHOW_NUMBER      040
1485#define OUTPUT_SHOW_SCORE      0100
1486
1487static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1488{
1489        int cnt;
1490        const char *cp;
1491        struct origin *suspect = ent->suspect;
1492        char hex[41];
1493
1494        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1495        printf("%s%c%d %d %d\n",
1496               hex,
1497               ent->guilty ? ' ' : '*', // purely for debugging
1498               ent->s_lno + 1,
1499               ent->lno + 1,
1500               ent->num_lines);
1501        if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1502                struct commit_info ci;
1503                suspect->commit->object.flags |= METAINFO_SHOWN;
1504                get_commit_info(suspect->commit, &ci, 1);
1505                printf("author %s\n", ci.author);
1506                printf("author-mail %s\n", ci.author_mail);
1507                printf("author-time %lu\n", ci.author_time);
1508                printf("author-tz %s\n", ci.author_tz);
1509                printf("committer %s\n", ci.committer);
1510                printf("committer-mail %s\n", ci.committer_mail);
1511                printf("committer-time %lu\n", ci.committer_time);
1512                printf("committer-tz %s\n", ci.committer_tz);
1513                write_filename_info(suspect->path);
1514                printf("summary %s\n", ci.summary);
1515                if (suspect->commit->object.flags & UNINTERESTING)
1516                        printf("boundary\n");
1517        }
1518        else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1519                write_filename_info(suspect->path);
1520
1521        cp = nth_line(sb, ent->lno);
1522        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1523                char ch;
1524                if (cnt)
1525                        printf("%s %d %d\n", hex,
1526                               ent->s_lno + 1 + cnt,
1527                               ent->lno + 1 + cnt);
1528                putchar('\t');
1529                do {
1530                        ch = *cp++;
1531                        putchar(ch);
1532                } while (ch != '\n' &&
1533                         cp < sb->final_buf + sb->final_buf_size);
1534        }
1535}
1536
1537static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1538{
1539        int cnt;
1540        const char *cp;
1541        struct origin *suspect = ent->suspect;
1542        struct commit_info ci;
1543        char hex[41];
1544        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1545
1546        get_commit_info(suspect->commit, &ci, 1);
1547        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1548
1549        cp = nth_line(sb, ent->lno);
1550        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1551                char ch;
1552                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1553
1554                if (suspect->commit->object.flags & UNINTERESTING) {
1555                        if (blank_boundary)
1556                                memset(hex, ' ', length);
1557                        else if (!cmd_is_annotate) {
1558                                length--;
1559                                putchar('^');
1560                        }
1561                }
1562
1563                printf("%.*s", length, hex);
1564                if (opt & OUTPUT_ANNOTATE_COMPAT)
1565                        printf("\t(%10s\t%10s\t%d)", ci.author,
1566                               format_time(ci.author_time, ci.author_tz,
1567                                           show_raw_time),
1568                               ent->lno + 1 + cnt);
1569                else {
1570                        if (opt & OUTPUT_SHOW_SCORE)
1571                                printf(" %*d %02d",
1572                                       max_score_digits, ent->score,
1573                                       ent->suspect->refcnt);
1574                        if (opt & OUTPUT_SHOW_NAME)
1575                                printf(" %-*.*s", longest_file, longest_file,
1576                                       suspect->path);
1577                        if (opt & OUTPUT_SHOW_NUMBER)
1578                                printf(" %*d", max_orig_digits,
1579                                       ent->s_lno + 1 + cnt);
1580                        printf(" (%-*.*s %10s %*d) ",
1581                               longest_author, longest_author, ci.author,
1582                               format_time(ci.author_time, ci.author_tz,
1583                                           show_raw_time),
1584                               max_digits, ent->lno + 1 + cnt);
1585                }
1586                do {
1587                        ch = *cp++;
1588                        putchar(ch);
1589                } while (ch != '\n' &&
1590                         cp < sb->final_buf + sb->final_buf_size);
1591        }
1592}
1593
1594static void output(struct scoreboard *sb, int option)
1595{
1596        struct blame_entry *ent;
1597
1598        if (option & OUTPUT_PORCELAIN) {
1599                for (ent = sb->ent; ent; ent = ent->next) {
1600                        struct blame_entry *oth;
1601                        struct origin *suspect = ent->suspect;
1602                        struct commit *commit = suspect->commit;
1603                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1604                                continue;
1605                        for (oth = ent->next; oth; oth = oth->next) {
1606                                if ((oth->suspect->commit != commit) ||
1607                                    !strcmp(oth->suspect->path, suspect->path))
1608                                        continue;
1609                                commit->object.flags |= MORE_THAN_ONE_PATH;
1610                                break;
1611                        }
1612                }
1613        }
1614
1615        for (ent = sb->ent; ent; ent = ent->next) {
1616                if (option & OUTPUT_PORCELAIN)
1617                        emit_porcelain(sb, ent);
1618                else {
1619                        emit_other(sb, ent, option);
1620                }
1621        }
1622}
1623
1624/*
1625 * To allow quick access to the contents of nth line in the
1626 * final image, prepare an index in the scoreboard.
1627 */
1628static int prepare_lines(struct scoreboard *sb)
1629{
1630        const char *buf = sb->final_buf;
1631        unsigned long len = sb->final_buf_size;
1632        int num = 0, incomplete = 0, bol = 1;
1633
1634        if (len && buf[len-1] != '\n')
1635                incomplete++; /* incomplete line at the end */
1636        while (len--) {
1637                if (bol) {
1638                        sb->lineno = xrealloc(sb->lineno,
1639                                              sizeof(int* ) * (num + 1));
1640                        sb->lineno[num] = buf - sb->final_buf;
1641                        bol = 0;
1642                }
1643                if (*buf++ == '\n') {
1644                        num++;
1645                        bol = 1;
1646                }
1647        }
1648        sb->lineno = xrealloc(sb->lineno,
1649                              sizeof(int* ) * (num + incomplete + 1));
1650        sb->lineno[num + incomplete] = buf - sb->final_buf;
1651        sb->num_lines = num + incomplete;
1652        return sb->num_lines;
1653}
1654
1655/*
1656 * Add phony grafts for use with -S; this is primarily to
1657 * support git-cvsserver that wants to give a linear history
1658 * to its clients.
1659 */
1660static int read_ancestry(const char *graft_file)
1661{
1662        FILE *fp = fopen(graft_file, "r");
1663        char buf[1024];
1664        if (!fp)
1665                return -1;
1666        while (fgets(buf, sizeof(buf), fp)) {
1667                /* The format is just "Commit Parent1 Parent2 ...\n" */
1668                int len = strlen(buf);
1669                struct commit_graft *graft = read_graft_line(buf, len);
1670                if (graft)
1671                        register_commit_graft(graft, 0);
1672        }
1673        fclose(fp);
1674        return 0;
1675}
1676
1677/*
1678 * How many columns do we need to show line numbers in decimal?
1679 */
1680static int lineno_width(int lines)
1681{
1682        int i, width;
1683
1684        for (width = 1, i = 10; i <= lines + 1; width++)
1685                i *= 10;
1686        return width;
1687}
1688
1689/*
1690 * How many columns do we need to show line numbers, authors,
1691 * and filenames?
1692 */
1693static void find_alignment(struct scoreboard *sb, int *option)
1694{
1695        int longest_src_lines = 0;
1696        int longest_dst_lines = 0;
1697        unsigned largest_score = 0;
1698        struct blame_entry *e;
1699
1700        for (e = sb->ent; e; e = e->next) {
1701                struct origin *suspect = e->suspect;
1702                struct commit_info ci;
1703                int num;
1704
1705                if (strcmp(suspect->path, sb->path))
1706                        *option |= OUTPUT_SHOW_NAME;
1707                num = strlen(suspect->path);
1708                if (longest_file < num)
1709                        longest_file = num;
1710                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1711                        suspect->commit->object.flags |= METAINFO_SHOWN;
1712                        get_commit_info(suspect->commit, &ci, 1);
1713                        num = strlen(ci.author);
1714                        if (longest_author < num)
1715                                longest_author = num;
1716                }
1717                num = e->s_lno + e->num_lines;
1718                if (longest_src_lines < num)
1719                        longest_src_lines = num;
1720                num = e->lno + e->num_lines;
1721                if (longest_dst_lines < num)
1722                        longest_dst_lines = num;
1723                if (largest_score < ent_score(sb, e))
1724                        largest_score = ent_score(sb, e);
1725        }
1726        max_orig_digits = lineno_width(longest_src_lines);
1727        max_digits = lineno_width(longest_dst_lines);
1728        max_score_digits = lineno_width(largest_score);
1729}
1730
1731/*
1732 * For debugging -- origin is refcounted, and this asserts that
1733 * we do not underflow.
1734 */
1735static void sanity_check_refcnt(struct scoreboard *sb)
1736{
1737        int baa = 0;
1738        struct blame_entry *ent;
1739
1740        for (ent = sb->ent; ent; ent = ent->next) {
1741                /* Nobody should have zero or negative refcnt */
1742                if (ent->suspect->refcnt <= 0) {
1743                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1744                                ent->suspect->path,
1745                                sha1_to_hex(ent->suspect->commit->object.sha1),
1746                                ent->suspect->refcnt);
1747                        baa = 1;
1748                }
1749        }
1750        for (ent = sb->ent; ent; ent = ent->next) {
1751                /* Mark the ones that haven't been checked */
1752                if (0 < ent->suspect->refcnt)
1753                        ent->suspect->refcnt = -ent->suspect->refcnt;
1754        }
1755        for (ent = sb->ent; ent; ent = ent->next) {
1756                /*
1757                 * ... then pick each and see if they have the the
1758                 * correct refcnt.
1759                 */
1760                int found;
1761                struct blame_entry *e;
1762                struct origin *suspect = ent->suspect;
1763
1764                if (0 < suspect->refcnt)
1765                        continue;
1766                suspect->refcnt = -suspect->refcnt; /* Unmark */
1767                for (found = 0, e = sb->ent; e; e = e->next) {
1768                        if (e->suspect != suspect)
1769                                continue;
1770                        found++;
1771                }
1772                if (suspect->refcnt != found) {
1773                        fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1774                                ent->suspect->path,
1775                                sha1_to_hex(ent->suspect->commit->object.sha1),
1776                                ent->suspect->refcnt, found);
1777                        baa = 2;
1778                }
1779        }
1780        if (baa) {
1781                int opt = 0160;
1782                find_alignment(sb, &opt);
1783                output(sb, opt);
1784                die("Baa %d!", baa);
1785        }
1786}
1787
1788/*
1789 * Used for the command line parsing; check if the path exists
1790 * in the working tree.
1791 */
1792static int has_path_in_work_tree(const char *path)
1793{
1794        struct stat st;
1795        return !lstat(path, &st);
1796}
1797
1798static unsigned parse_score(const char *arg)
1799{
1800        char *end;
1801        unsigned long score = strtoul(arg, &end, 10);
1802        if (*end)
1803                return 0;
1804        return score;
1805}
1806
1807static const char *add_prefix(const char *prefix, const char *path)
1808{
1809        if (!prefix || !prefix[0])
1810                return path;
1811        return prefix_path(prefix, strlen(prefix), path);
1812}
1813
1814/*
1815 * Parsing of (comma separated) one item in the -L option
1816 */
1817static const char *parse_loc(const char *spec,
1818                             struct scoreboard *sb, long lno,
1819                             long begin, long *ret)
1820{
1821        char *term;
1822        const char *line;
1823        long num;
1824        int reg_error;
1825        regex_t regexp;
1826        regmatch_t match[1];
1827
1828        /* Allow "-L <something>,+20" to mean starting at <something>
1829         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1830         * <something>.
1831         */
1832        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1833                num = strtol(spec + 1, &term, 10);
1834                if (term != spec + 1) {
1835                        if (spec[0] == '-')
1836                                num = 0 - num;
1837                        if (0 < num)
1838                                *ret = begin + num - 2;
1839                        else if (!num)
1840                                *ret = begin;
1841                        else
1842                                *ret = begin + num;
1843                        return term;
1844                }
1845                return spec;
1846        }
1847        num = strtol(spec, &term, 10);
1848        if (term != spec) {
1849                *ret = num;
1850                return term;
1851        }
1852        if (spec[0] != '/')
1853                return spec;
1854
1855        /* it could be a regexp of form /.../ */
1856        for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1857                if (*term == '\\')
1858                        term++;
1859        }
1860        if (*term != '/')
1861                return spec;
1862
1863        /* try [spec+1 .. term-1] as regexp */
1864        *term = 0;
1865        begin--; /* input is in human terms */
1866        line = nth_line(sb, begin);
1867
1868        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1869            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1870                const char *cp = line + match[0].rm_so;
1871                const char *nline;
1872
1873                while (begin++ < lno) {
1874                        nline = nth_line(sb, begin);
1875                        if (line <= cp && cp < nline)
1876                                break;
1877                        line = nline;
1878                }
1879                *ret = begin;
1880                regfree(&regexp);
1881                *term++ = '/';
1882                return term;
1883        }
1884        else {
1885                char errbuf[1024];
1886                regerror(reg_error, &regexp, errbuf, 1024);
1887                die("-L parameter '%s': %s", spec + 1, errbuf);
1888        }
1889}
1890
1891/*
1892 * Parsing of -L option
1893 */
1894static void prepare_blame_range(struct scoreboard *sb,
1895                                const char *bottomtop,
1896                                long lno,
1897                                long *bottom, long *top)
1898{
1899        const char *term;
1900
1901        term = parse_loc(bottomtop, sb, lno, 1, bottom);
1902        if (*term == ',') {
1903                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1904                if (*term)
1905                        usage(blame_usage);
1906        }
1907        if (*term)
1908                usage(blame_usage);
1909}
1910
1911static int git_blame_config(const char *var, const char *value)
1912{
1913        if (!strcmp(var, "blame.showroot")) {
1914                show_root = git_config_bool(var, value);
1915                return 0;
1916        }
1917        if (!strcmp(var, "blame.blankboundary")) {
1918                blank_boundary = git_config_bool(var, value);
1919                return 0;
1920        }
1921        return git_default_config(var, value);
1922}
1923
1924static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1925{
1926        struct commit *commit;
1927        struct origin *origin;
1928        unsigned char head_sha1[20];
1929        char *buf;
1930        const char *ident;
1931        int fd;
1932        time_t now;
1933        unsigned long fin_size;
1934        int size, len;
1935        struct cache_entry *ce;
1936        unsigned mode;
1937
1938        if (get_sha1("HEAD", head_sha1))
1939                die("No such ref: HEAD");
1940
1941        time(&now);
1942        commit = xcalloc(1, sizeof(*commit));
1943        commit->parents = xcalloc(1, sizeof(*commit->parents));
1944        commit->parents->item = lookup_commit_reference(head_sha1);
1945        commit->object.parsed = 1;
1946        commit->date = now;
1947        commit->object.type = OBJ_COMMIT;
1948
1949        origin = make_origin(commit, path);
1950
1951        if (!contents_from || strcmp("-", contents_from)) {
1952                struct stat st;
1953                const char *read_from;
1954
1955                if (contents_from) {
1956                        if (stat(contents_from, &st) < 0)
1957                                die("Cannot stat %s", contents_from);
1958                        read_from = contents_from;
1959                }
1960                else {
1961                        if (lstat(path, &st) < 0)
1962                                die("Cannot lstat %s", path);
1963                        read_from = path;
1964                }
1965                fin_size = xsize_t(st.st_size);
1966                buf = xmalloc(fin_size+1);
1967                mode = canon_mode(st.st_mode);
1968                switch (st.st_mode & S_IFMT) {
1969                case S_IFREG:
1970                        fd = open(read_from, O_RDONLY);
1971                        if (fd < 0)
1972                                die("cannot open %s", read_from);
1973                        if (read_in_full(fd, buf, fin_size) != fin_size)
1974                                die("cannot read %s", read_from);
1975                        break;
1976                case S_IFLNK:
1977                        if (readlink(read_from, buf, fin_size+1) != fin_size)
1978                                die("cannot readlink %s", read_from);
1979                        break;
1980                default:
1981                        die("unsupported file type %s", read_from);
1982                }
1983        }
1984        else {
1985                /* Reading from stdin */
1986                contents_from = "standard input";
1987                buf = NULL;
1988                fin_size = 0;
1989                mode = 0;
1990                while (1) {
1991                        ssize_t cnt = 8192;
1992                        buf = xrealloc(buf, fin_size + cnt);
1993                        cnt = xread(0, buf + fin_size, cnt);
1994                        if (cnt < 0)
1995                                die("read error %s from stdin",
1996                                    strerror(errno));
1997                        if (!cnt)
1998                                break;
1999                        fin_size += cnt;
2000                }
2001                buf = xrealloc(buf, fin_size + 1);
2002        }
2003        buf[fin_size] = 0;
2004        origin->file.ptr = buf;
2005        origin->file.size = fin_size;
2006        pretend_sha1_file(buf, fin_size, OBJ_BLOB, origin->blob_sha1);
2007        commit->util = origin;
2008
2009        /*
2010         * Read the current index, replace the path entry with
2011         * origin->blob_sha1 without mucking with its mode or type
2012         * bits; we are not going to write this index out -- we just
2013         * want to run "diff-index --cached".
2014         */
2015        discard_cache();
2016        read_cache();
2017
2018        len = strlen(path);
2019        if (!mode) {
2020                int pos = cache_name_pos(path, len);
2021                if (0 <= pos)
2022                        mode = ntohl(active_cache[pos]->ce_mode);
2023                else
2024                        /* Let's not bother reading from HEAD tree */
2025                        mode = S_IFREG | 0644;
2026        }
2027        size = cache_entry_size(len);
2028        ce = xcalloc(1, size);
2029        hashcpy(ce->sha1, origin->blob_sha1);
2030        memcpy(ce->name, path, len);
2031        ce->ce_flags = create_ce_flags(len, 0);
2032        ce->ce_mode = create_ce_mode(mode);
2033        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2034
2035        /*
2036         * We are not going to write this out, so this does not matter
2037         * right now, but someday we might optimize diff-index --cached
2038         * with cache-tree information.
2039         */
2040        cache_tree_invalidate_path(active_cache_tree, path);
2041
2042        commit->buffer = xmalloc(400);
2043        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2044        sprintf(commit->buffer,
2045                "tree 0000000000000000000000000000000000000000\n"
2046                "parent %s\n"
2047                "author %s\n"
2048                "committer %s\n\n"
2049                "Version of %s from %s\n",
2050                sha1_to_hex(head_sha1),
2051                ident, ident, path, contents_from ? contents_from : path);
2052        return commit;
2053}
2054
2055int cmd_blame(int argc, const char **argv, const char *prefix)
2056{
2057        struct rev_info revs;
2058        const char *path;
2059        struct scoreboard sb;
2060        struct origin *o;
2061        struct blame_entry *ent;
2062        int i, seen_dashdash, unk, opt;
2063        long bottom, top, lno;
2064        int output_option = 0;
2065        int show_stats = 0;
2066        const char *revs_file = NULL;
2067        const char *final_commit_name = NULL;
2068        enum object_type type;
2069        const char *bottomtop = NULL;
2070        const char *contents_from = NULL;
2071
2072        cmd_is_annotate = !strcmp(argv[0], "annotate");
2073
2074        git_config(git_blame_config);
2075        save_commit_buffer = 0;
2076
2077        opt = 0;
2078        seen_dashdash = 0;
2079        for (unk = i = 1; i < argc; i++) {
2080                const char *arg = argv[i];
2081                if (*arg != '-')
2082                        break;
2083                else if (!strcmp("-b", arg))
2084                        blank_boundary = 1;
2085                else if (!strcmp("--root", arg))
2086                        show_root = 1;
2087                else if (!strcmp(arg, "--show-stats"))
2088                        show_stats = 1;
2089                else if (!strcmp("-c", arg))
2090                        output_option |= OUTPUT_ANNOTATE_COMPAT;
2091                else if (!strcmp("-t", arg))
2092                        output_option |= OUTPUT_RAW_TIMESTAMP;
2093                else if (!strcmp("-l", arg))
2094                        output_option |= OUTPUT_LONG_OBJECT_NAME;
2095                else if (!strcmp("-S", arg) && ++i < argc)
2096                        revs_file = argv[i];
2097                else if (!prefixcmp(arg, "-M")) {
2098                        opt |= PICKAXE_BLAME_MOVE;
2099                        blame_move_score = parse_score(arg+2);
2100                }
2101                else if (!prefixcmp(arg, "-C")) {
2102                        if (opt & PICKAXE_BLAME_COPY)
2103                                opt |= PICKAXE_BLAME_COPY_HARDER;
2104                        opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2105                        blame_copy_score = parse_score(arg+2);
2106                }
2107                else if (!prefixcmp(arg, "-L")) {
2108                        if (!arg[2]) {
2109                                if (++i >= argc)
2110                                        usage(blame_usage);
2111                                arg = argv[i];
2112                        }
2113                        else
2114                                arg += 2;
2115                        if (bottomtop)
2116                                die("More than one '-L n,m' option given");
2117                        bottomtop = arg;
2118                }
2119                else if (!strcmp("--contents", arg)) {
2120                        if (++i >= argc)
2121                                usage(blame_usage);
2122                        contents_from = argv[i];
2123                }
2124                else if (!strcmp("--incremental", arg))
2125                        incremental = 1;
2126                else if (!strcmp("--score-debug", arg))
2127                        output_option |= OUTPUT_SHOW_SCORE;
2128                else if (!strcmp("-f", arg) ||
2129                         !strcmp("--show-name", arg))
2130                        output_option |= OUTPUT_SHOW_NAME;
2131                else if (!strcmp("-n", arg) ||
2132                         !strcmp("--show-number", arg))
2133                        output_option |= OUTPUT_SHOW_NUMBER;
2134                else if (!strcmp("-p", arg) ||
2135                         !strcmp("--porcelain", arg))
2136                        output_option |= OUTPUT_PORCELAIN;
2137                else if (!strcmp("--", arg)) {
2138                        seen_dashdash = 1;
2139                        i++;
2140                        break;
2141                }
2142                else
2143                        argv[unk++] = arg;
2144        }
2145
2146        if (!incremental)
2147                setup_pager();
2148
2149        if (!blame_move_score)
2150                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2151        if (!blame_copy_score)
2152                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2153
2154        /*
2155         * We have collected options unknown to us in argv[1..unk]
2156         * which are to be passed to revision machinery if we are
2157         * going to do the "bottom" processing.
2158         *
2159         * The remaining are:
2160         *
2161         * (1) if seen_dashdash, its either
2162         *     "-options -- <path>" or
2163         *     "-options -- <path> <rev>".
2164         *     but the latter is allowed only if there is no
2165         *     options that we passed to revision machinery.
2166         *
2167         * (2) otherwise, we may have "--" somewhere later and
2168         *     might be looking at the first one of multiple 'rev'
2169         *     parameters (e.g. " master ^next ^maint -- path").
2170         *     See if there is a dashdash first, and give the
2171         *     arguments before that to revision machinery.
2172         *     After that there must be one 'path'.
2173         *
2174         * (3) otherwise, its one of the three:
2175         *     "-options <path> <rev>"
2176         *     "-options <rev> <path>"
2177         *     "-options <path>"
2178         *     but again the first one is allowed only if
2179         *     there is no options that we passed to revision
2180         *     machinery.
2181         */
2182
2183        if (seen_dashdash) {
2184                /* (1) */
2185                if (argc <= i)
2186                        usage(blame_usage);
2187                path = add_prefix(prefix, argv[i]);
2188                if (i + 1 == argc - 1) {
2189                        if (unk != 1)
2190                                usage(blame_usage);
2191                        argv[unk++] = argv[i + 1];
2192                }
2193                else if (i + 1 != argc)
2194                        /* garbage at end */
2195                        usage(blame_usage);
2196        }
2197        else {
2198                int j;
2199                for (j = i; !seen_dashdash && j < argc; j++)
2200                        if (!strcmp(argv[j], "--"))
2201                                seen_dashdash = j;
2202                if (seen_dashdash) {
2203                        /* (2) */
2204                        if (seen_dashdash + 1 != argc - 1)
2205                                usage(blame_usage);
2206                        path = add_prefix(prefix, argv[seen_dashdash + 1]);
2207                        for (j = i; j < seen_dashdash; j++)
2208                                argv[unk++] = argv[j];
2209                }
2210                else {
2211                        /* (3) */
2212                        if (argc <= i)
2213                                usage(blame_usage);
2214                        path = add_prefix(prefix, argv[i]);
2215                        if (i + 1 == argc - 1) {
2216                                final_commit_name = argv[i + 1];
2217
2218                                /* if (unk == 1) we could be getting
2219                                 * old-style
2220                                 */
2221                                if (unk == 1 && !has_path_in_work_tree(path)) {
2222                                        path = add_prefix(prefix, argv[i + 1]);
2223                                        final_commit_name = argv[i];
2224                                }
2225                        }
2226                        else if (i != argc - 1)
2227                                usage(blame_usage); /* garbage at end */
2228
2229                        if (!has_path_in_work_tree(path))
2230                                die("cannot stat path %s: %s",
2231                                    path, strerror(errno));
2232                }
2233        }
2234
2235        if (final_commit_name)
2236                argv[unk++] = final_commit_name;
2237
2238        /*
2239         * Now we got rev and path.  We do not want the path pruning
2240         * but we may want "bottom" processing.
2241         */
2242        argv[unk++] = "--"; /* terminate the rev name */
2243        argv[unk] = NULL;
2244
2245        init_revisions(&revs, NULL);
2246        setup_revisions(unk, argv, &revs, NULL);
2247        memset(&sb, 0, sizeof(sb));
2248
2249        /*
2250         * There must be one and only one positive commit in the
2251         * revs->pending array.
2252         */
2253        for (i = 0; i < revs.pending.nr; i++) {
2254                struct object *obj = revs.pending.objects[i].item;
2255                if (obj->flags & UNINTERESTING)
2256                        continue;
2257                while (obj->type == OBJ_TAG)
2258                        obj = deref_tag(obj, NULL, 0);
2259                if (obj->type != OBJ_COMMIT)
2260                        die("Non commit %s?",
2261                            revs.pending.objects[i].name);
2262                if (sb.final)
2263                        die("More than one commit to dig from %s and %s?",
2264                            revs.pending.objects[i].name,
2265                            final_commit_name);
2266                sb.final = (struct commit *) obj;
2267                final_commit_name = revs.pending.objects[i].name;
2268        }
2269
2270        if (!sb.final) {
2271                /*
2272                 * "--not A B -- path" without anything positive;
2273                 * do not default to HEAD, but use the working tree
2274                 * or "--contents".
2275                 */
2276                sb.final = fake_working_tree_commit(path, contents_from);
2277                add_pending_object(&revs, &(sb.final->object), ":");
2278        }
2279        else if (contents_from)
2280                die("Cannot use --contents with final commit object name");
2281
2282        /*
2283         * If we have bottom, this will mark the ancestors of the
2284         * bottom commits we would reach while traversing as
2285         * uninteresting.
2286         */
2287        prepare_revision_walk(&revs);
2288
2289        if (is_null_sha1(sb.final->object.sha1)) {
2290                char *buf;
2291                o = sb.final->util;
2292                buf = xmalloc(o->file.size + 1);
2293                memcpy(buf, o->file.ptr, o->file.size + 1);
2294                sb.final_buf = buf;
2295                sb.final_buf_size = o->file.size;
2296        }
2297        else {
2298                o = get_origin(&sb, sb.final, path);
2299                if (fill_blob_sha1(o))
2300                        die("no such path %s in %s", path, final_commit_name);
2301
2302                sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2303                                              &sb.final_buf_size);
2304        }
2305        num_read_blob++;
2306        lno = prepare_lines(&sb);
2307
2308        bottom = top = 0;
2309        if (bottomtop)
2310                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2311        if (bottom && top && top < bottom) {
2312                long tmp;
2313                tmp = top; top = bottom; bottom = tmp;
2314        }
2315        if (bottom < 1)
2316                bottom = 1;
2317        if (top < 1)
2318                top = lno;
2319        bottom--;
2320        if (lno < top)
2321                die("file %s has only %lu lines", path, lno);
2322
2323        ent = xcalloc(1, sizeof(*ent));
2324        ent->lno = bottom;
2325        ent->num_lines = top - bottom;
2326        ent->suspect = o;
2327        ent->s_lno = bottom;
2328
2329        sb.ent = ent;
2330        sb.path = path;
2331
2332        if (revs_file && read_ancestry(revs_file))
2333                die("reading graft file %s failed: %s",
2334                    revs_file, strerror(errno));
2335
2336        assign_blame(&sb, &revs, opt);
2337
2338        if (incremental)
2339                return 0;
2340
2341        coalesce(&sb);
2342
2343        if (!(output_option & OUTPUT_PORCELAIN))
2344                find_alignment(&sb, &output_option);
2345
2346        output(&sb, output_option);
2347        free((void *)sb.final_buf);
2348        for (ent = sb.ent; ent; ) {
2349                struct blame_entry *e = ent->next;
2350                free(ent);
2351                ent = e;
2352        }
2353
2354        if (show_stats) {
2355                printf("num read blob: %d\n", num_read_blob);
2356                printf("num get patch: %d\n", num_get_patch);
2357                printf("num commits: %d\n", num_commits);
2358        }
2359        return 0;
2360}