builtin-blame.con commit blame: drop blob data after passing blame to the parent (7c3c796)
   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                if (!file->ptr)
 102                        die("Cannot read blob %s for path %s",
 103                            sha1_to_hex(o->blob_sha1),
 104                            o->path);
 105                o->file = *file;
 106        }
 107        else
 108                *file = o->file;
 109        return file->ptr;
 110}
 111
 112/*
 113 * Origin is refcounted and usually we keep the blob contents to be
 114 * reused.
 115 */
 116static inline struct origin *origin_incref(struct origin *o)
 117{
 118        if (o)
 119                o->refcnt++;
 120        return o;
 121}
 122
 123static void origin_decref(struct origin *o)
 124{
 125        if (o && --o->refcnt <= 0) {
 126                if (o->file.ptr)
 127                        free(o->file.ptr);
 128                memset(o, 0, sizeof(*o));
 129                free(o);
 130        }
 131}
 132
 133static void drop_origin_blob(struct origin *o)
 134{
 135        if (o->file.ptr) {
 136                free(o->file.ptr);
 137                o->file.ptr = NULL;
 138        }
 139}
 140
 141/*
 142 * Each group of lines is described by a blame_entry; it can be split
 143 * as we pass blame to the parents.  They form a linked list in the
 144 * scoreboard structure, sorted by the target line number.
 145 */
 146struct blame_entry {
 147        struct blame_entry *prev;
 148        struct blame_entry *next;
 149
 150        /* the first line of this group in the final image;
 151         * internally all line numbers are 0 based.
 152         */
 153        int lno;
 154
 155        /* how many lines this group has */
 156        int num_lines;
 157
 158        /* the commit that introduced this group into the final image */
 159        struct origin *suspect;
 160
 161        /* true if the suspect is truly guilty; false while we have not
 162         * checked if the group came from one of its parents.
 163         */
 164        char guilty;
 165
 166        /* the line number of the first line of this group in the
 167         * suspect's file; internally all line numbers are 0 based.
 168         */
 169        int s_lno;
 170
 171        /* how significant this entry is -- cached to avoid
 172         * scanning the lines over and over.
 173         */
 174        unsigned score;
 175};
 176
 177/*
 178 * The current state of the blame assignment.
 179 */
 180struct scoreboard {
 181        /* the final commit (i.e. where we started digging from) */
 182        struct commit *final;
 183
 184        const char *path;
 185
 186        /*
 187         * The contents in the final image.
 188         * Used by many functions to obtain contents of the nth line,
 189         * indexed with scoreboard.lineno[blame_entry.lno].
 190         */
 191        const char *final_buf;
 192        unsigned long final_buf_size;
 193
 194        /* linked list of blames */
 195        struct blame_entry *ent;
 196
 197        /* look-up a line in the final buffer */
 198        int num_lines;
 199        int *lineno;
 200};
 201
 202static inline int same_suspect(struct origin *a, struct origin *b)
 203{
 204        if (a == b)
 205                return 1;
 206        if (a->commit != b->commit)
 207                return 0;
 208        return !strcmp(a->path, b->path);
 209}
 210
 211static void sanity_check_refcnt(struct scoreboard *);
 212
 213/*
 214 * If two blame entries that are next to each other came from
 215 * contiguous lines in the same origin (i.e. <commit, path> pair),
 216 * merge them together.
 217 */
 218static void coalesce(struct scoreboard *sb)
 219{
 220        struct blame_entry *ent, *next;
 221
 222        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 223                if (same_suspect(ent->suspect, next->suspect) &&
 224                    ent->guilty == next->guilty &&
 225                    ent->s_lno + ent->num_lines == next->s_lno) {
 226                        ent->num_lines += next->num_lines;
 227                        ent->next = next->next;
 228                        if (ent->next)
 229                                ent->next->prev = ent;
 230                        origin_decref(next->suspect);
 231                        free(next);
 232                        ent->score = 0;
 233                        next = ent; /* again */
 234                }
 235        }
 236
 237        if (DEBUG) /* sanity */
 238                sanity_check_refcnt(sb);
 239}
 240
 241/*
 242 * Given a commit and a path in it, create a new origin structure.
 243 * The callers that add blame to the scoreboard should use
 244 * get_origin() to obtain shared, refcounted copy instead of calling
 245 * this function directly.
 246 */
 247static struct origin *make_origin(struct commit *commit, const char *path)
 248{
 249        struct origin *o;
 250        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 251        o->commit = commit;
 252        o->refcnt = 1;
 253        strcpy(o->path, path);
 254        return o;
 255}
 256
 257/*
 258 * Locate an existing origin or create a new one.
 259 */
 260static struct origin *get_origin(struct scoreboard *sb,
 261                                 struct commit *commit,
 262                                 const char *path)
 263{
 264        struct blame_entry *e;
 265
 266        for (e = sb->ent; e; e = e->next) {
 267                if (e->suspect->commit == commit &&
 268                    !strcmp(e->suspect->path, path))
 269                        return origin_incref(e->suspect);
 270        }
 271        return make_origin(commit, path);
 272}
 273
 274/*
 275 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 276 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 277 * for an origin is also used to pass the blame for the entire file to
 278 * the parent to detect the case where a child's blob is identical to
 279 * that of its parent's.
 280 */
 281static int fill_blob_sha1(struct origin *origin)
 282{
 283        unsigned mode;
 284
 285        if (!is_null_sha1(origin->blob_sha1))
 286                return 0;
 287        if (get_tree_entry(origin->commit->object.sha1,
 288                           origin->path,
 289                           origin->blob_sha1, &mode))
 290                goto error_out;
 291        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 292                goto error_out;
 293        return 0;
 294 error_out:
 295        hashclr(origin->blob_sha1);
 296        return -1;
 297}
 298
 299/*
 300 * We have an origin -- check if the same path exists in the
 301 * parent and return an origin structure to represent it.
 302 */
 303static struct origin *find_origin(struct scoreboard *sb,
 304                                  struct commit *parent,
 305                                  struct origin *origin)
 306{
 307        struct origin *porigin = NULL;
 308        struct diff_options diff_opts;
 309        const char *paths[2];
 310
 311        if (parent->util) {
 312                /*
 313                 * Each commit object can cache one origin in that
 314                 * commit.  This is a freestanding copy of origin and
 315                 * not refcounted.
 316                 */
 317                struct origin *cached = parent->util;
 318                if (!strcmp(cached->path, origin->path)) {
 319                        /*
 320                         * The same path between origin and its parent
 321                         * without renaming -- the most common case.
 322                         */
 323                        porigin = get_origin(sb, parent, cached->path);
 324
 325                        /*
 326                         * If the origin was newly created (i.e. get_origin
 327                         * would call make_origin if none is found in the
 328                         * scoreboard), it does not know the blob_sha1,
 329                         * so copy it.  Otherwise porigin was in the
 330                         * scoreboard and already knows blob_sha1.
 331                         */
 332                        if (porigin->refcnt == 1)
 333                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 334                        return porigin;
 335                }
 336                /* otherwise it was not very useful; free it */
 337                free(parent->util);
 338                parent->util = NULL;
 339        }
 340
 341        /* See if the origin->path is different between parent
 342         * and origin first.  Most of the time they are the
 343         * same and diff-tree is fairly efficient about this.
 344         */
 345        diff_setup(&diff_opts);
 346        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 347        diff_opts.detect_rename = 0;
 348        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 349        paths[0] = origin->path;
 350        paths[1] = NULL;
 351
 352        diff_tree_setup_paths(paths, &diff_opts);
 353        if (diff_setup_done(&diff_opts) < 0)
 354                die("diff-setup");
 355
 356        if (is_null_sha1(origin->commit->object.sha1))
 357                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 358        else
 359                diff_tree_sha1(parent->tree->object.sha1,
 360                               origin->commit->tree->object.sha1,
 361                               "", &diff_opts);
 362        diffcore_std(&diff_opts);
 363
 364        /* It is either one entry that says "modified", or "created",
 365         * or nothing.
 366         */
 367        if (!diff_queued_diff.nr) {
 368                /* The path is the same as parent */
 369                porigin = get_origin(sb, parent, origin->path);
 370                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 371        }
 372        else if (diff_queued_diff.nr != 1)
 373                die("internal error in blame::find_origin");
 374        else {
 375                struct diff_filepair *p = diff_queued_diff.queue[0];
 376                switch (p->status) {
 377                default:
 378                        die("internal error in blame::find_origin (%c)",
 379                            p->status);
 380                case 'M':
 381                        porigin = get_origin(sb, parent, origin->path);
 382                        hashcpy(porigin->blob_sha1, p->one->sha1);
 383                        break;
 384                case 'A':
 385                case 'T':
 386                        /* Did not exist in parent, or type changed */
 387                        break;
 388                }
 389        }
 390        diff_flush(&diff_opts);
 391        if (porigin) {
 392                /*
 393                 * Create a freestanding copy that is not part of
 394                 * the refcounted origin found in the scoreboard, and
 395                 * cache it in the commit.
 396                 */
 397                struct origin *cached;
 398
 399                cached = make_origin(porigin->commit, porigin->path);
 400                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 401                parent->util = cached;
 402        }
 403        return porigin;
 404}
 405
 406/*
 407 * We have an origin -- find the path that corresponds to it in its
 408 * parent and return an origin structure to represent it.
 409 */
 410static struct origin *find_rename(struct scoreboard *sb,
 411                                  struct commit *parent,
 412                                  struct origin *origin)
 413{
 414        struct origin *porigin = NULL;
 415        struct diff_options diff_opts;
 416        int i;
 417        const char *paths[2];
 418
 419        diff_setup(&diff_opts);
 420        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 421        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 422        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 423        diff_opts.single_follow = origin->path;
 424        paths[0] = NULL;
 425        diff_tree_setup_paths(paths, &diff_opts);
 426        if (diff_setup_done(&diff_opts) < 0)
 427                die("diff-setup");
 428
 429        if (is_null_sha1(origin->commit->object.sha1))
 430                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 431        else
 432                diff_tree_sha1(parent->tree->object.sha1,
 433                               origin->commit->tree->object.sha1,
 434                               "", &diff_opts);
 435        diffcore_std(&diff_opts);
 436
 437        for (i = 0; i < diff_queued_diff.nr; i++) {
 438                struct diff_filepair *p = diff_queued_diff.queue[i];
 439                if ((p->status == 'R' || p->status == 'C') &&
 440                    !strcmp(p->two->path, origin->path)) {
 441                        porigin = get_origin(sb, parent, p->one->path);
 442                        hashcpy(porigin->blob_sha1, p->one->sha1);
 443                        break;
 444                }
 445        }
 446        diff_flush(&diff_opts);
 447        return porigin;
 448}
 449
 450/*
 451 * Parsing of patch chunks...
 452 */
 453struct chunk {
 454        /* line number in postimage; up to but not including this
 455         * line is the same as preimage
 456         */
 457        int same;
 458
 459        /* preimage line number after this chunk */
 460        int p_next;
 461
 462        /* postimage line number after this chunk */
 463        int t_next;
 464};
 465
 466struct patch {
 467        struct chunk *chunks;
 468        int num;
 469};
 470
 471struct blame_diff_state {
 472        struct xdiff_emit_state xm;
 473        struct patch *ret;
 474        unsigned hunk_post_context;
 475        unsigned hunk_in_pre_context : 1;
 476};
 477
 478static void process_u_diff(void *state_, char *line, unsigned long len)
 479{
 480        struct blame_diff_state *state = state_;
 481        struct chunk *chunk;
 482        int off1, off2, len1, len2, num;
 483
 484        num = state->ret->num;
 485        if (len < 4 || line[0] != '@' || line[1] != '@') {
 486                if (state->hunk_in_pre_context && line[0] == ' ')
 487                        state->ret->chunks[num - 1].same++;
 488                else {
 489                        state->hunk_in_pre_context = 0;
 490                        if (line[0] == ' ')
 491                                state->hunk_post_context++;
 492                        else
 493                                state->hunk_post_context = 0;
 494                }
 495                return;
 496        }
 497
 498        if (num && state->hunk_post_context) {
 499                chunk = &state->ret->chunks[num - 1];
 500                chunk->p_next -= state->hunk_post_context;
 501                chunk->t_next -= state->hunk_post_context;
 502        }
 503        state->ret->num = ++num;
 504        state->ret->chunks = xrealloc(state->ret->chunks,
 505                                      sizeof(struct chunk) * num);
 506        chunk = &state->ret->chunks[num - 1];
 507        if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
 508                state->ret->num--;
 509                return;
 510        }
 511
 512        /* Line numbers in patch output are one based. */
 513        off1--;
 514        off2--;
 515
 516        chunk->same = len2 ? off2 : (off2 + 1);
 517
 518        chunk->p_next = off1 + (len1 ? len1 : 1);
 519        chunk->t_next = chunk->same + len2;
 520        state->hunk_in_pre_context = 1;
 521        state->hunk_post_context = 0;
 522}
 523
 524static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
 525                                    int context)
 526{
 527        struct blame_diff_state state;
 528        xpparam_t xpp;
 529        xdemitconf_t xecfg;
 530        xdemitcb_t ecb;
 531
 532        xpp.flags = xdl_opts;
 533        memset(&xecfg, 0, sizeof(xecfg));
 534        xecfg.ctxlen = context;
 535        ecb.outf = xdiff_outf;
 536        ecb.priv = &state;
 537        memset(&state, 0, sizeof(state));
 538        state.xm.consume = process_u_diff;
 539        state.ret = xmalloc(sizeof(struct patch));
 540        state.ret->chunks = NULL;
 541        state.ret->num = 0;
 542
 543        xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
 544
 545        if (state.ret->num) {
 546                struct chunk *chunk;
 547                chunk = &state.ret->chunks[state.ret->num - 1];
 548                chunk->p_next -= state.hunk_post_context;
 549                chunk->t_next -= state.hunk_post_context;
 550        }
 551        return state.ret;
 552}
 553
 554/*
 555 * Run diff between two origins and grab the patch output, so that
 556 * we can pass blame for lines origin is currently suspected for
 557 * to its parent.
 558 */
 559static struct patch *get_patch(struct origin *parent, struct origin *origin)
 560{
 561        mmfile_t file_p, file_o;
 562        struct patch *patch;
 563
 564        fill_origin_blob(parent, &file_p);
 565        fill_origin_blob(origin, &file_o);
 566        if (!file_p.ptr || !file_o.ptr)
 567                return NULL;
 568        patch = compare_buffer(&file_p, &file_o, 0);
 569        num_get_patch++;
 570        return patch;
 571}
 572
 573static void free_patch(struct patch *p)
 574{
 575        free(p->chunks);
 576        free(p);
 577}
 578
 579/*
 580 * Link in a new blame entry to the scoreboard.  Entries that cover the
 581 * same line range have been removed from the scoreboard previously.
 582 */
 583static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 584{
 585        struct blame_entry *ent, *prev = NULL;
 586
 587        origin_incref(e->suspect);
 588
 589        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 590                prev = ent;
 591
 592        /* prev, if not NULL, is the last one that is below e */
 593        e->prev = prev;
 594        if (prev) {
 595                e->next = prev->next;
 596                prev->next = e;
 597        }
 598        else {
 599                e->next = sb->ent;
 600                sb->ent = e;
 601        }
 602        if (e->next)
 603                e->next->prev = e;
 604}
 605
 606/*
 607 * src typically is on-stack; we want to copy the information in it to
 608 * an malloced blame_entry that is already on the linked list of the
 609 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 610 * gains one.
 611 */
 612static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 613{
 614        struct blame_entry *p, *n;
 615
 616        p = dst->prev;
 617        n = dst->next;
 618        origin_incref(src->suspect);
 619        origin_decref(dst->suspect);
 620        memcpy(dst, src, sizeof(*src));
 621        dst->prev = p;
 622        dst->next = n;
 623        dst->score = 0;
 624}
 625
 626static const char *nth_line(struct scoreboard *sb, int lno)
 627{
 628        return sb->final_buf + sb->lineno[lno];
 629}
 630
 631/*
 632 * It is known that lines between tlno to same came from parent, and e
 633 * has an overlap with that range.  it also is known that parent's
 634 * line plno corresponds to e's line tlno.
 635 *
 636 *                <---- e ----->
 637 *                   <------>
 638 *                   <------------>
 639 *             <------------>
 640 *             <------------------>
 641 *
 642 * Split e into potentially three parts; before this chunk, the chunk
 643 * to be blamed for the parent, and after that portion.
 644 */
 645static void split_overlap(struct blame_entry *split,
 646                          struct blame_entry *e,
 647                          int tlno, int plno, int same,
 648                          struct origin *parent)
 649{
 650        int chunk_end_lno;
 651        memset(split, 0, sizeof(struct blame_entry [3]));
 652
 653        if (e->s_lno < tlno) {
 654                /* there is a pre-chunk part not blamed on parent */
 655                split[0].suspect = origin_incref(e->suspect);
 656                split[0].lno = e->lno;
 657                split[0].s_lno = e->s_lno;
 658                split[0].num_lines = tlno - e->s_lno;
 659                split[1].lno = e->lno + tlno - e->s_lno;
 660                split[1].s_lno = plno;
 661        }
 662        else {
 663                split[1].lno = e->lno;
 664                split[1].s_lno = plno + (e->s_lno - tlno);
 665        }
 666
 667        if (same < e->s_lno + e->num_lines) {
 668                /* there is a post-chunk part not blamed on parent */
 669                split[2].suspect = origin_incref(e->suspect);
 670                split[2].lno = e->lno + (same - e->s_lno);
 671                split[2].s_lno = e->s_lno + (same - e->s_lno);
 672                split[2].num_lines = e->s_lno + e->num_lines - same;
 673                chunk_end_lno = split[2].lno;
 674        }
 675        else
 676                chunk_end_lno = e->lno + e->num_lines;
 677        split[1].num_lines = chunk_end_lno - split[1].lno;
 678
 679        /*
 680         * if it turns out there is nothing to blame the parent for,
 681         * forget about the splitting.  !split[1].suspect signals this.
 682         */
 683        if (split[1].num_lines < 1)
 684                return;
 685        split[1].suspect = origin_incref(parent);
 686}
 687
 688/*
 689 * split_overlap() divided an existing blame e into up to three parts
 690 * in split.  Adjust the linked list of blames in the scoreboard to
 691 * reflect the split.
 692 */
 693static void split_blame(struct scoreboard *sb,
 694                        struct blame_entry *split,
 695                        struct blame_entry *e)
 696{
 697        struct blame_entry *new_entry;
 698
 699        if (split[0].suspect && split[2].suspect) {
 700                /* The first part (reuse storage for the existing entry e) */
 701                dup_entry(e, &split[0]);
 702
 703                /* The last part -- me */
 704                new_entry = xmalloc(sizeof(*new_entry));
 705                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 706                add_blame_entry(sb, new_entry);
 707
 708                /* ... and the middle part -- parent */
 709                new_entry = xmalloc(sizeof(*new_entry));
 710                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 711                add_blame_entry(sb, new_entry);
 712        }
 713        else if (!split[0].suspect && !split[2].suspect)
 714                /*
 715                 * The parent covers the entire area; reuse storage for
 716                 * e and replace it with the parent.
 717                 */
 718                dup_entry(e, &split[1]);
 719        else if (split[0].suspect) {
 720                /* me and then parent */
 721                dup_entry(e, &split[0]);
 722
 723                new_entry = xmalloc(sizeof(*new_entry));
 724                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 725                add_blame_entry(sb, new_entry);
 726        }
 727        else {
 728                /* parent and then me */
 729                dup_entry(e, &split[1]);
 730
 731                new_entry = xmalloc(sizeof(*new_entry));
 732                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 733                add_blame_entry(sb, new_entry);
 734        }
 735
 736        if (DEBUG) { /* sanity */
 737                struct blame_entry *ent;
 738                int lno = sb->ent->lno, corrupt = 0;
 739
 740                for (ent = sb->ent; ent; ent = ent->next) {
 741                        if (lno != ent->lno)
 742                                corrupt = 1;
 743                        if (ent->s_lno < 0)
 744                                corrupt = 1;
 745                        lno += ent->num_lines;
 746                }
 747                if (corrupt) {
 748                        lno = sb->ent->lno;
 749                        for (ent = sb->ent; ent; ent = ent->next) {
 750                                printf("L %8d l %8d n %8d\n",
 751                                       lno, ent->lno, ent->num_lines);
 752                                lno = ent->lno + ent->num_lines;
 753                        }
 754                        die("oops");
 755                }
 756        }
 757}
 758
 759/*
 760 * After splitting the blame, the origins used by the
 761 * on-stack blame_entry should lose one refcnt each.
 762 */
 763static void decref_split(struct blame_entry *split)
 764{
 765        int i;
 766
 767        for (i = 0; i < 3; i++)
 768                origin_decref(split[i].suspect);
 769}
 770
 771/*
 772 * Helper for blame_chunk().  blame_entry e is known to overlap with
 773 * the patch hunk; split it and pass blame to the parent.
 774 */
 775static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 776                          int tlno, int plno, int same,
 777                          struct origin *parent)
 778{
 779        struct blame_entry split[3];
 780
 781        split_overlap(split, e, tlno, plno, same, parent);
 782        if (split[1].suspect)
 783                split_blame(sb, split, e);
 784        decref_split(split);
 785}
 786
 787/*
 788 * Find the line number of the last line the target is suspected for.
 789 */
 790static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 791{
 792        struct blame_entry *e;
 793        int last_in_target = -1;
 794
 795        for (e = sb->ent; e; e = e->next) {
 796                if (e->guilty || !same_suspect(e->suspect, target))
 797                        continue;
 798                if (last_in_target < e->s_lno + e->num_lines)
 799                        last_in_target = e->s_lno + e->num_lines;
 800        }
 801        return last_in_target;
 802}
 803
 804/*
 805 * Process one hunk from the patch between the current suspect for
 806 * blame_entry e and its parent.  Find and split the overlap, and
 807 * pass blame to the overlapping part to the parent.
 808 */
 809static void blame_chunk(struct scoreboard *sb,
 810                        int tlno, int plno, int same,
 811                        struct origin *target, struct origin *parent)
 812{
 813        struct blame_entry *e;
 814
 815        for (e = sb->ent; e; e = e->next) {
 816                if (e->guilty || !same_suspect(e->suspect, target))
 817                        continue;
 818                if (same <= e->s_lno)
 819                        continue;
 820                if (tlno < e->s_lno + e->num_lines)
 821                        blame_overlap(sb, e, tlno, plno, same, parent);
 822        }
 823}
 824
 825/*
 826 * We are looking at the origin 'target' and aiming to pass blame
 827 * for the lines it is suspected to its parent.  Run diff to find
 828 * which lines came from parent and pass blame for them.
 829 */
 830static int pass_blame_to_parent(struct scoreboard *sb,
 831                                struct origin *target,
 832                                struct origin *parent)
 833{
 834        int i, last_in_target, plno, tlno;
 835        struct patch *patch;
 836
 837        last_in_target = find_last_in_target(sb, target);
 838        if (last_in_target < 0)
 839                return 1; /* nothing remains for this target */
 840
 841        patch = get_patch(parent, target);
 842        plno = tlno = 0;
 843        for (i = 0; i < patch->num; i++) {
 844                struct chunk *chunk = &patch->chunks[i];
 845
 846                blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 847                plno = chunk->p_next;
 848                tlno = chunk->t_next;
 849        }
 850        /* The rest (i.e. anything after tlno) are the same as the parent */
 851        blame_chunk(sb, tlno, plno, last_in_target, target, parent);
 852
 853        free_patch(patch);
 854        return 0;
 855}
 856
 857/*
 858 * The lines in blame_entry after splitting blames many times can become
 859 * very small and trivial, and at some point it becomes pointless to
 860 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 861 * ordinary C program, and it is not worth to say it was copied from
 862 * totally unrelated file in the parent.
 863 *
 864 * Compute how trivial the lines in the blame_entry are.
 865 */
 866static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 867{
 868        unsigned score;
 869        const char *cp, *ep;
 870
 871        if (e->score)
 872                return e->score;
 873
 874        score = 1;
 875        cp = nth_line(sb, e->lno);
 876        ep = nth_line(sb, e->lno + e->num_lines);
 877        while (cp < ep) {
 878                unsigned ch = *((unsigned char *)cp);
 879                if (isalnum(ch))
 880                        score++;
 881                cp++;
 882        }
 883        e->score = score;
 884        return score;
 885}
 886
 887/*
 888 * best_so_far[] and this[] are both a split of an existing blame_entry
 889 * that passes blame to the parent.  Maintain best_so_far the best split
 890 * so far, by comparing this and best_so_far and copying this into
 891 * bst_so_far as needed.
 892 */
 893static void copy_split_if_better(struct scoreboard *sb,
 894                                 struct blame_entry *best_so_far,
 895                                 struct blame_entry *this)
 896{
 897        int i;
 898
 899        if (!this[1].suspect)
 900                return;
 901        if (best_so_far[1].suspect) {
 902                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 903                        return;
 904        }
 905
 906        for (i = 0; i < 3; i++)
 907                origin_incref(this[i].suspect);
 908        decref_split(best_so_far);
 909        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 910}
 911
 912/*
 913 * We are looking at a part of the final image represented by
 914 * ent (tlno and same are offset by ent->s_lno).
 915 * tlno is where we are looking at in the final image.
 916 * up to (but not including) same match preimage.
 917 * plno is where we are looking at in the preimage.
 918 *
 919 * <-------------- final image ---------------------->
 920 *       <------ent------>
 921 *         ^tlno ^same
 922 *    <---------preimage----->
 923 *         ^plno
 924 *
 925 * All line numbers are 0-based.
 926 */
 927static void handle_split(struct scoreboard *sb,
 928                         struct blame_entry *ent,
 929                         int tlno, int plno, int same,
 930                         struct origin *parent,
 931                         struct blame_entry *split)
 932{
 933        if (ent->num_lines <= tlno)
 934                return;
 935        if (tlno < same) {
 936                struct blame_entry this[3];
 937                tlno += ent->s_lno;
 938                same += ent->s_lno;
 939                split_overlap(this, ent, tlno, plno, same, parent);
 940                copy_split_if_better(sb, split, this);
 941                decref_split(this);
 942        }
 943}
 944
 945/*
 946 * Find the lines from parent that are the same as ent so that
 947 * we can pass blames to it.  file_p has the blob contents for
 948 * the parent.
 949 */
 950static void find_copy_in_blob(struct scoreboard *sb,
 951                              struct blame_entry *ent,
 952                              struct origin *parent,
 953                              struct blame_entry *split,
 954                              mmfile_t *file_p)
 955{
 956        const char *cp;
 957        int cnt;
 958        mmfile_t file_o;
 959        struct patch *patch;
 960        int i, plno, tlno;
 961
 962        /*
 963         * Prepare mmfile that contains only the lines in ent.
 964         */
 965        cp = nth_line(sb, ent->lno);
 966        file_o.ptr = (char*) cp;
 967        cnt = ent->num_lines;
 968
 969        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 970                if (*cp++ == '\n')
 971                        cnt--;
 972        }
 973        file_o.size = cp - file_o.ptr;
 974
 975        patch = compare_buffer(file_p, &file_o, 1);
 976
 977        /*
 978         * file_o is a part of final image we are annotating.
 979         * file_p partially may match that image.
 980         */
 981        memset(split, 0, sizeof(struct blame_entry [3]));
 982        plno = tlno = 0;
 983        for (i = 0; i < patch->num; i++) {
 984                struct chunk *chunk = &patch->chunks[i];
 985
 986                handle_split(sb, ent, tlno, plno, chunk->same, parent, split);
 987                plno = chunk->p_next;
 988                tlno = chunk->t_next;
 989        }
 990        /* remainder, if any, all match the preimage */
 991        handle_split(sb, ent, tlno, plno, ent->num_lines, parent, split);
 992        free_patch(patch);
 993}
 994
 995/*
 996 * See if lines currently target is suspected for can be attributed to
 997 * parent.
 998 */
 999static int find_move_in_parent(struct scoreboard *sb,
1000                               struct origin *target,
1001                               struct origin *parent)
1002{
1003        int last_in_target, made_progress;
1004        struct blame_entry *e, split[3];
1005        mmfile_t file_p;
1006
1007        last_in_target = find_last_in_target(sb, target);
1008        if (last_in_target < 0)
1009                return 1; /* nothing remains for this target */
1010
1011        fill_origin_blob(parent, &file_p);
1012        if (!file_p.ptr)
1013                return 0;
1014
1015        made_progress = 1;
1016        while (made_progress) {
1017                made_progress = 0;
1018                for (e = sb->ent; e; e = e->next) {
1019                        if (e->guilty || !same_suspect(e->suspect, target))
1020                                continue;
1021                        find_copy_in_blob(sb, e, parent, split, &file_p);
1022                        if (split[1].suspect &&
1023                            blame_move_score < ent_score(sb, &split[1])) {
1024                                split_blame(sb, split, e);
1025                                made_progress = 1;
1026                        }
1027                        decref_split(split);
1028                }
1029        }
1030        return 0;
1031}
1032
1033struct blame_list {
1034        struct blame_entry *ent;
1035        struct blame_entry split[3];
1036};
1037
1038/*
1039 * Count the number of entries the target is suspected for,
1040 * and prepare a list of entry and the best split.
1041 */
1042static struct blame_list *setup_blame_list(struct scoreboard *sb,
1043                                           struct origin *target,
1044                                           int *num_ents_p)
1045{
1046        struct blame_entry *e;
1047        int num_ents, i;
1048        struct blame_list *blame_list = NULL;
1049
1050        for (e = sb->ent, num_ents = 0; e; e = e->next)
1051                if (!e->guilty && same_suspect(e->suspect, target))
1052                        num_ents++;
1053        if (num_ents) {
1054                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1055                for (e = sb->ent, i = 0; e; e = e->next)
1056                        if (!e->guilty && same_suspect(e->suspect, target))
1057                                blame_list[i++].ent = e;
1058        }
1059        *num_ents_p = num_ents;
1060        return blame_list;
1061}
1062
1063/*
1064 * For lines target is suspected for, see if we can find code movement
1065 * across file boundary from the parent commit.  porigin is the path
1066 * in the parent we already tried.
1067 */
1068static int find_copy_in_parent(struct scoreboard *sb,
1069                               struct origin *target,
1070                               struct commit *parent,
1071                               struct origin *porigin,
1072                               int opt)
1073{
1074        struct diff_options diff_opts;
1075        const char *paths[1];
1076        int i, j;
1077        int retval;
1078        struct blame_list *blame_list;
1079        int num_ents;
1080
1081        blame_list = setup_blame_list(sb, target, &num_ents);
1082        if (!blame_list)
1083                return 1; /* nothing remains for this target */
1084
1085        diff_setup(&diff_opts);
1086        DIFF_OPT_SET(&diff_opts, RECURSIVE);
1087        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1088
1089        paths[0] = NULL;
1090        diff_tree_setup_paths(paths, &diff_opts);
1091        if (diff_setup_done(&diff_opts) < 0)
1092                die("diff-setup");
1093
1094        /* Try "find copies harder" on new path if requested;
1095         * we do not want to use diffcore_rename() actually to
1096         * match things up; find_copies_harder is set only to
1097         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1098         * and this code needs to be after diff_setup_done(), which
1099         * usually makes find-copies-harder imply copy detection.
1100         */
1101        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1102            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1103                && (!porigin || strcmp(target->path, porigin->path))))
1104                DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
1105
1106        if (is_null_sha1(target->commit->object.sha1))
1107                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1108        else
1109                diff_tree_sha1(parent->tree->object.sha1,
1110                               target->commit->tree->object.sha1,
1111                               "", &diff_opts);
1112
1113        if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
1114                diffcore_std(&diff_opts);
1115
1116        retval = 0;
1117        while (1) {
1118                int made_progress = 0;
1119
1120                for (i = 0; i < diff_queued_diff.nr; i++) {
1121                        struct diff_filepair *p = diff_queued_diff.queue[i];
1122                        struct origin *norigin;
1123                        mmfile_t file_p;
1124                        struct blame_entry this[3];
1125
1126                        if (!DIFF_FILE_VALID(p->one))
1127                                continue; /* does not exist in parent */
1128                        if (porigin && !strcmp(p->one->path, porigin->path))
1129                                /* find_move already dealt with this path */
1130                                continue;
1131
1132                        norigin = get_origin(sb, parent, p->one->path);
1133                        hashcpy(norigin->blob_sha1, p->one->sha1);
1134                        fill_origin_blob(norigin, &file_p);
1135                        if (!file_p.ptr)
1136                                continue;
1137
1138                        for (j = 0; j < num_ents; j++) {
1139                                find_copy_in_blob(sb, blame_list[j].ent,
1140                                                  norigin, this, &file_p);
1141                                copy_split_if_better(sb, blame_list[j].split,
1142                                                     this);
1143                                decref_split(this);
1144                        }
1145                        origin_decref(norigin);
1146                }
1147
1148                for (j = 0; j < num_ents; j++) {
1149                        struct blame_entry *split = blame_list[j].split;
1150                        if (split[1].suspect &&
1151                            blame_copy_score < ent_score(sb, &split[1])) {
1152                                split_blame(sb, split, blame_list[j].ent);
1153                                made_progress = 1;
1154                        }
1155                        decref_split(split);
1156                }
1157                free(blame_list);
1158
1159                if (!made_progress)
1160                        break;
1161                blame_list = setup_blame_list(sb, target, &num_ents);
1162                if (!blame_list) {
1163                        retval = 1;
1164                        break;
1165                }
1166        }
1167        diff_flush(&diff_opts);
1168
1169        return retval;
1170}
1171
1172/*
1173 * The blobs of origin and porigin exactly match, so everything
1174 * origin is suspected for can be blamed on the parent.
1175 */
1176static void pass_whole_blame(struct scoreboard *sb,
1177                             struct origin *origin, struct origin *porigin)
1178{
1179        struct blame_entry *e;
1180
1181        if (!porigin->file.ptr && origin->file.ptr) {
1182                /* Steal its file */
1183                porigin->file = origin->file;
1184                origin->file.ptr = NULL;
1185        }
1186        for (e = sb->ent; e; e = e->next) {
1187                if (!same_suspect(e->suspect, origin))
1188                        continue;
1189                origin_incref(porigin);
1190                origin_decref(e->suspect);
1191                e->suspect = porigin;
1192        }
1193}
1194
1195#define MAXPARENT 16
1196
1197static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1198{
1199        int i, pass;
1200        struct commit *commit = origin->commit;
1201        struct commit_list *parent;
1202        struct origin *parent_origin[MAXPARENT], *porigin;
1203
1204        memset(parent_origin, 0, sizeof(parent_origin));
1205
1206        /* The first pass looks for unrenamed path to optimize for
1207         * common cases, then we look for renames in the second pass.
1208         */
1209        for (pass = 0; pass < 2; pass++) {
1210                struct origin *(*find)(struct scoreboard *,
1211                                       struct commit *, struct origin *);
1212                find = pass ? find_rename : find_origin;
1213
1214                for (i = 0, parent = commit->parents;
1215                     i < MAXPARENT && parent;
1216                     parent = parent->next, i++) {
1217                        struct commit *p = parent->item;
1218                        int j, same;
1219
1220                        if (parent_origin[i])
1221                                continue;
1222                        if (parse_commit(p))
1223                                continue;
1224                        porigin = find(sb, p, origin);
1225                        if (!porigin)
1226                                continue;
1227                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1228                                pass_whole_blame(sb, origin, porigin);
1229                                origin_decref(porigin);
1230                                goto finish;
1231                        }
1232                        for (j = same = 0; j < i; j++)
1233                                if (parent_origin[j] &&
1234                                    !hashcmp(parent_origin[j]->blob_sha1,
1235                                             porigin->blob_sha1)) {
1236                                        same = 1;
1237                                        break;
1238                                }
1239                        if (!same)
1240                                parent_origin[i] = porigin;
1241                        else
1242                                origin_decref(porigin);
1243                }
1244        }
1245
1246        num_commits++;
1247        for (i = 0, parent = commit->parents;
1248             i < MAXPARENT && parent;
1249             parent = parent->next, i++) {
1250                struct origin *porigin = parent_origin[i];
1251                if (!porigin)
1252                        continue;
1253                if (pass_blame_to_parent(sb, origin, porigin))
1254                        goto finish;
1255        }
1256
1257        /*
1258         * Optionally find moves in parents' files.
1259         */
1260        if (opt & PICKAXE_BLAME_MOVE)
1261                for (i = 0, parent = commit->parents;
1262                     i < MAXPARENT && parent;
1263                     parent = parent->next, i++) {
1264                        struct origin *porigin = parent_origin[i];
1265                        if (!porigin)
1266                                continue;
1267                        if (find_move_in_parent(sb, origin, porigin))
1268                                goto finish;
1269                }
1270
1271        /*
1272         * Optionally find copies from parents' files.
1273         */
1274        if (opt & PICKAXE_BLAME_COPY)
1275                for (i = 0, parent = commit->parents;
1276                     i < MAXPARENT && parent;
1277                     parent = parent->next, i++) {
1278                        struct origin *porigin = parent_origin[i];
1279                        if (find_copy_in_parent(sb, origin, parent->item,
1280                                                porigin, opt))
1281                                goto finish;
1282                }
1283
1284 finish:
1285        for (i = 0; i < MAXPARENT; i++) {
1286                if (parent_origin[i]) {
1287                        drop_origin_blob(parent_origin[i]);
1288                        origin_decref(parent_origin[i]);
1289                }
1290        }
1291        drop_origin_blob(origin);
1292}
1293
1294/*
1295 * Information on commits, used for output.
1296 */
1297struct commit_info
1298{
1299        const char *author;
1300        const char *author_mail;
1301        unsigned long author_time;
1302        const char *author_tz;
1303
1304        /* filled only when asked for details */
1305        const char *committer;
1306        const char *committer_mail;
1307        unsigned long committer_time;
1308        const char *committer_tz;
1309
1310        const char *summary;
1311};
1312
1313/*
1314 * Parse author/committer line in the commit object buffer
1315 */
1316static void get_ac_line(const char *inbuf, const char *what,
1317                        int bufsz, char *person, const char **mail,
1318                        unsigned long *time, const char **tz)
1319{
1320        int len, tzlen, maillen;
1321        char *tmp, *endp, *timepos;
1322
1323        tmp = strstr(inbuf, what);
1324        if (!tmp)
1325                goto error_out;
1326        tmp += strlen(what);
1327        endp = strchr(tmp, '\n');
1328        if (!endp)
1329                len = strlen(tmp);
1330        else
1331                len = endp - tmp;
1332        if (bufsz <= len) {
1333        error_out:
1334                /* Ugh */
1335                *mail = *tz = "(unknown)";
1336                *time = 0;
1337                return;
1338        }
1339        memcpy(person, tmp, len);
1340
1341        tmp = person;
1342        tmp += len;
1343        *tmp = 0;
1344        while (*tmp != ' ')
1345                tmp--;
1346        *tz = tmp+1;
1347        tzlen = (person+len)-(tmp+1);
1348
1349        *tmp = 0;
1350        while (*tmp != ' ')
1351                tmp--;
1352        *time = strtoul(tmp, NULL, 10);
1353        timepos = tmp;
1354
1355        *tmp = 0;
1356        while (*tmp != ' ')
1357                tmp--;
1358        *mail = tmp + 1;
1359        *tmp = 0;
1360        maillen = timepos - tmp;
1361
1362        if (!mailmap.nr)
1363                return;
1364
1365        /*
1366         * mailmap expansion may make the name longer.
1367         * make room by pushing stuff down.
1368         */
1369        tmp = person + bufsz - (tzlen + 1);
1370        memmove(tmp, *tz, tzlen);
1371        tmp[tzlen] = 0;
1372        *tz = tmp;
1373
1374        tmp = tmp - (maillen + 1);
1375        memmove(tmp, *mail, maillen);
1376        tmp[maillen] = 0;
1377        *mail = tmp;
1378
1379        /*
1380         * Now, convert e-mail using mailmap
1381         */
1382        map_email(&mailmap, tmp + 1, person, tmp-person-1);
1383}
1384
1385static void get_commit_info(struct commit *commit,
1386                            struct commit_info *ret,
1387                            int detailed)
1388{
1389        int len;
1390        char *tmp, *endp;
1391        static char author_buf[1024];
1392        static char committer_buf[1024];
1393        static char summary_buf[1024];
1394
1395        /*
1396         * We've operated without save_commit_buffer, so
1397         * we now need to populate them for output.
1398         */
1399        if (!commit->buffer) {
1400                enum object_type type;
1401                unsigned long size;
1402                commit->buffer =
1403                        read_sha1_file(commit->object.sha1, &type, &size);
1404                if (!commit->buffer)
1405                        die("Cannot read commit %s",
1406                            sha1_to_hex(commit->object.sha1));
1407        }
1408        ret->author = author_buf;
1409        get_ac_line(commit->buffer, "\nauthor ",
1410                    sizeof(author_buf), author_buf, &ret->author_mail,
1411                    &ret->author_time, &ret->author_tz);
1412
1413        if (!detailed)
1414                return;
1415
1416        ret->committer = committer_buf;
1417        get_ac_line(commit->buffer, "\ncommitter ",
1418                    sizeof(committer_buf), committer_buf, &ret->committer_mail,
1419                    &ret->committer_time, &ret->committer_tz);
1420
1421        ret->summary = summary_buf;
1422        tmp = strstr(commit->buffer, "\n\n");
1423        if (!tmp) {
1424        error_out:
1425                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1426                return;
1427        }
1428        tmp += 2;
1429        endp = strchr(tmp, '\n');
1430        if (!endp)
1431                endp = tmp + strlen(tmp);
1432        len = endp - tmp;
1433        if (len >= sizeof(summary_buf) || len == 0)
1434                goto error_out;
1435        memcpy(summary_buf, tmp, len);
1436        summary_buf[len] = 0;
1437}
1438
1439/*
1440 * To allow LF and other nonportable characters in pathnames,
1441 * they are c-style quoted as needed.
1442 */
1443static void write_filename_info(const char *path)
1444{
1445        printf("filename ");
1446        write_name_quoted(path, stdout, '\n');
1447}
1448
1449/*
1450 * The blame_entry is found to be guilty for the range.  Mark it
1451 * as such, and show it in incremental output.
1452 */
1453static void found_guilty_entry(struct blame_entry *ent)
1454{
1455        if (ent->guilty)
1456                return;
1457        ent->guilty = 1;
1458        if (incremental) {
1459                struct origin *suspect = ent->suspect;
1460
1461                printf("%s %d %d %d\n",
1462                       sha1_to_hex(suspect->commit->object.sha1),
1463                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1464                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1465                        struct commit_info ci;
1466                        suspect->commit->object.flags |= METAINFO_SHOWN;
1467                        get_commit_info(suspect->commit, &ci, 1);
1468                        printf("author %s\n", ci.author);
1469                        printf("author-mail %s\n", ci.author_mail);
1470                        printf("author-time %lu\n", ci.author_time);
1471                        printf("author-tz %s\n", ci.author_tz);
1472                        printf("committer %s\n", ci.committer);
1473                        printf("committer-mail %s\n", ci.committer_mail);
1474                        printf("committer-time %lu\n", ci.committer_time);
1475                        printf("committer-tz %s\n", ci.committer_tz);
1476                        printf("summary %s\n", ci.summary);
1477                        if (suspect->commit->object.flags & UNINTERESTING)
1478                                printf("boundary\n");
1479                }
1480                write_filename_info(suspect->path);
1481                maybe_flush_or_die(stdout, "stdout");
1482        }
1483}
1484
1485/*
1486 * The main loop -- while the scoreboard has lines whose true origin
1487 * is still unknown, pick one blame_entry, and allow its current
1488 * suspect to pass blames to its parents.
1489 */
1490static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1491{
1492        while (1) {
1493                struct blame_entry *ent;
1494                struct commit *commit;
1495                struct origin *suspect = NULL;
1496
1497                /* find one suspect to break down */
1498                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1499                        if (!ent->guilty)
1500                                suspect = ent->suspect;
1501                if (!suspect)
1502                        return; /* all done */
1503
1504                /*
1505                 * We will use this suspect later in the loop,
1506                 * so hold onto it in the meantime.
1507                 */
1508                origin_incref(suspect);
1509                commit = suspect->commit;
1510                if (!commit->object.parsed)
1511                        parse_commit(commit);
1512                if (!(commit->object.flags & UNINTERESTING) &&
1513                    !(revs->max_age != -1 && commit->date < revs->max_age))
1514                        pass_blame(sb, suspect, opt);
1515                else {
1516                        commit->object.flags |= UNINTERESTING;
1517                        if (commit->object.parsed)
1518                                mark_parents_uninteresting(commit);
1519                }
1520                /* treat root commit as boundary */
1521                if (!commit->parents && !show_root)
1522                        commit->object.flags |= UNINTERESTING;
1523
1524                /* Take responsibility for the remaining entries */
1525                for (ent = sb->ent; ent; ent = ent->next)
1526                        if (same_suspect(ent->suspect, suspect))
1527                                found_guilty_entry(ent);
1528                origin_decref(suspect);
1529
1530                if (DEBUG) /* sanity */
1531                        sanity_check_refcnt(sb);
1532        }
1533}
1534
1535static const char *format_time(unsigned long time, const char *tz_str,
1536                               int show_raw_time)
1537{
1538        static char time_buf[128];
1539        time_t t = time;
1540        int minutes, tz;
1541        struct tm *tm;
1542
1543        if (show_raw_time) {
1544                sprintf(time_buf, "%lu %s", time, tz_str);
1545                return time_buf;
1546        }
1547
1548        tz = atoi(tz_str);
1549        minutes = tz < 0 ? -tz : tz;
1550        minutes = (minutes / 100)*60 + (minutes % 100);
1551        minutes = tz < 0 ? -minutes : minutes;
1552        t = time + minutes * 60;
1553        tm = gmtime(&t);
1554
1555        strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1556        strcat(time_buf, tz_str);
1557        return time_buf;
1558}
1559
1560#define OUTPUT_ANNOTATE_COMPAT  001
1561#define OUTPUT_LONG_OBJECT_NAME 002
1562#define OUTPUT_RAW_TIMESTAMP    004
1563#define OUTPUT_PORCELAIN        010
1564#define OUTPUT_SHOW_NAME        020
1565#define OUTPUT_SHOW_NUMBER      040
1566#define OUTPUT_SHOW_SCORE      0100
1567#define OUTPUT_NO_AUTHOR       0200
1568
1569static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1570{
1571        int cnt;
1572        const char *cp;
1573        struct origin *suspect = ent->suspect;
1574        char hex[41];
1575
1576        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1577        printf("%s%c%d %d %d\n",
1578               hex,
1579               ent->guilty ? ' ' : '*', // purely for debugging
1580               ent->s_lno + 1,
1581               ent->lno + 1,
1582               ent->num_lines);
1583        if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1584                struct commit_info ci;
1585                suspect->commit->object.flags |= METAINFO_SHOWN;
1586                get_commit_info(suspect->commit, &ci, 1);
1587                printf("author %s\n", ci.author);
1588                printf("author-mail %s\n", ci.author_mail);
1589                printf("author-time %lu\n", ci.author_time);
1590                printf("author-tz %s\n", ci.author_tz);
1591                printf("committer %s\n", ci.committer);
1592                printf("committer-mail %s\n", ci.committer_mail);
1593                printf("committer-time %lu\n", ci.committer_time);
1594                printf("committer-tz %s\n", ci.committer_tz);
1595                write_filename_info(suspect->path);
1596                printf("summary %s\n", ci.summary);
1597                if (suspect->commit->object.flags & UNINTERESTING)
1598                        printf("boundary\n");
1599        }
1600        else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1601                write_filename_info(suspect->path);
1602
1603        cp = nth_line(sb, ent->lno);
1604        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1605                char ch;
1606                if (cnt)
1607                        printf("%s %d %d\n", hex,
1608                               ent->s_lno + 1 + cnt,
1609                               ent->lno + 1 + cnt);
1610                putchar('\t');
1611                do {
1612                        ch = *cp++;
1613                        putchar(ch);
1614                } while (ch != '\n' &&
1615                         cp < sb->final_buf + sb->final_buf_size);
1616        }
1617}
1618
1619static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1620{
1621        int cnt;
1622        const char *cp;
1623        struct origin *suspect = ent->suspect;
1624        struct commit_info ci;
1625        char hex[41];
1626        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1627
1628        get_commit_info(suspect->commit, &ci, 1);
1629        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1630
1631        cp = nth_line(sb, ent->lno);
1632        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1633                char ch;
1634                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1635
1636                if (suspect->commit->object.flags & UNINTERESTING) {
1637                        if (blank_boundary)
1638                                memset(hex, ' ', length);
1639                        else if (!cmd_is_annotate) {
1640                                length--;
1641                                putchar('^');
1642                        }
1643                }
1644
1645                printf("%.*s", length, hex);
1646                if (opt & OUTPUT_ANNOTATE_COMPAT)
1647                        printf("\t(%10s\t%10s\t%d)", ci.author,
1648                               format_time(ci.author_time, ci.author_tz,
1649                                           show_raw_time),
1650                               ent->lno + 1 + cnt);
1651                else {
1652                        if (opt & OUTPUT_SHOW_SCORE)
1653                                printf(" %*d %02d",
1654                                       max_score_digits, ent->score,
1655                                       ent->suspect->refcnt);
1656                        if (opt & OUTPUT_SHOW_NAME)
1657                                printf(" %-*.*s", longest_file, longest_file,
1658                                       suspect->path);
1659                        if (opt & OUTPUT_SHOW_NUMBER)
1660                                printf(" %*d", max_orig_digits,
1661                                       ent->s_lno + 1 + cnt);
1662
1663                        if (!(opt & OUTPUT_NO_AUTHOR))
1664                                printf(" (%-*.*s %10s",
1665                                       longest_author, longest_author,
1666                                       ci.author,
1667                                       format_time(ci.author_time,
1668                                                   ci.author_tz,
1669                                                   show_raw_time));
1670                        printf(" %*d) ",
1671                               max_digits, ent->lno + 1 + cnt);
1672                }
1673                do {
1674                        ch = *cp++;
1675                        putchar(ch);
1676                } while (ch != '\n' &&
1677                         cp < sb->final_buf + sb->final_buf_size);
1678        }
1679}
1680
1681static void output(struct scoreboard *sb, int option)
1682{
1683        struct blame_entry *ent;
1684
1685        if (option & OUTPUT_PORCELAIN) {
1686                for (ent = sb->ent; ent; ent = ent->next) {
1687                        struct blame_entry *oth;
1688                        struct origin *suspect = ent->suspect;
1689                        struct commit *commit = suspect->commit;
1690                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1691                                continue;
1692                        for (oth = ent->next; oth; oth = oth->next) {
1693                                if ((oth->suspect->commit != commit) ||
1694                                    !strcmp(oth->suspect->path, suspect->path))
1695                                        continue;
1696                                commit->object.flags |= MORE_THAN_ONE_PATH;
1697                                break;
1698                        }
1699                }
1700        }
1701
1702        for (ent = sb->ent; ent; ent = ent->next) {
1703                if (option & OUTPUT_PORCELAIN)
1704                        emit_porcelain(sb, ent);
1705                else {
1706                        emit_other(sb, ent, option);
1707                }
1708        }
1709}
1710
1711/*
1712 * To allow quick access to the contents of nth line in the
1713 * final image, prepare an index in the scoreboard.
1714 */
1715static int prepare_lines(struct scoreboard *sb)
1716{
1717        const char *buf = sb->final_buf;
1718        unsigned long len = sb->final_buf_size;
1719        int num = 0, incomplete = 0, bol = 1;
1720
1721        if (len && buf[len-1] != '\n')
1722                incomplete++; /* incomplete line at the end */
1723        while (len--) {
1724                if (bol) {
1725                        sb->lineno = xrealloc(sb->lineno,
1726                                              sizeof(int* ) * (num + 1));
1727                        sb->lineno[num] = buf - sb->final_buf;
1728                        bol = 0;
1729                }
1730                if (*buf++ == '\n') {
1731                        num++;
1732                        bol = 1;
1733                }
1734        }
1735        sb->lineno = xrealloc(sb->lineno,
1736                              sizeof(int* ) * (num + incomplete + 1));
1737        sb->lineno[num + incomplete] = buf - sb->final_buf;
1738        sb->num_lines = num + incomplete;
1739        return sb->num_lines;
1740}
1741
1742/*
1743 * Add phony grafts for use with -S; this is primarily to
1744 * support git-cvsserver that wants to give a linear history
1745 * to its clients.
1746 */
1747static int read_ancestry(const char *graft_file)
1748{
1749        FILE *fp = fopen(graft_file, "r");
1750        char buf[1024];
1751        if (!fp)
1752                return -1;
1753        while (fgets(buf, sizeof(buf), fp)) {
1754                /* The format is just "Commit Parent1 Parent2 ...\n" */
1755                int len = strlen(buf);
1756                struct commit_graft *graft = read_graft_line(buf, len);
1757                if (graft)
1758                        register_commit_graft(graft, 0);
1759        }
1760        fclose(fp);
1761        return 0;
1762}
1763
1764/*
1765 * How many columns do we need to show line numbers in decimal?
1766 */
1767static int lineno_width(int lines)
1768{
1769        int i, width;
1770
1771        for (width = 1, i = 10; i <= lines + 1; width++)
1772                i *= 10;
1773        return width;
1774}
1775
1776/*
1777 * How many columns do we need to show line numbers, authors,
1778 * and filenames?
1779 */
1780static void find_alignment(struct scoreboard *sb, int *option)
1781{
1782        int longest_src_lines = 0;
1783        int longest_dst_lines = 0;
1784        unsigned largest_score = 0;
1785        struct blame_entry *e;
1786
1787        for (e = sb->ent; e; e = e->next) {
1788                struct origin *suspect = e->suspect;
1789                struct commit_info ci;
1790                int num;
1791
1792                if (strcmp(suspect->path, sb->path))
1793                        *option |= OUTPUT_SHOW_NAME;
1794                num = strlen(suspect->path);
1795                if (longest_file < num)
1796                        longest_file = num;
1797                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1798                        suspect->commit->object.flags |= METAINFO_SHOWN;
1799                        get_commit_info(suspect->commit, &ci, 1);
1800                        num = strlen(ci.author);
1801                        if (longest_author < num)
1802                                longest_author = num;
1803                }
1804                num = e->s_lno + e->num_lines;
1805                if (longest_src_lines < num)
1806                        longest_src_lines = num;
1807                num = e->lno + e->num_lines;
1808                if (longest_dst_lines < num)
1809                        longest_dst_lines = num;
1810                if (largest_score < ent_score(sb, e))
1811                        largest_score = ent_score(sb, e);
1812        }
1813        max_orig_digits = lineno_width(longest_src_lines);
1814        max_digits = lineno_width(longest_dst_lines);
1815        max_score_digits = lineno_width(largest_score);
1816}
1817
1818/*
1819 * For debugging -- origin is refcounted, and this asserts that
1820 * we do not underflow.
1821 */
1822static void sanity_check_refcnt(struct scoreboard *sb)
1823{
1824        int baa = 0;
1825        struct blame_entry *ent;
1826
1827        for (ent = sb->ent; ent; ent = ent->next) {
1828                /* Nobody should have zero or negative refcnt */
1829                if (ent->suspect->refcnt <= 0) {
1830                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1831                                ent->suspect->path,
1832                                sha1_to_hex(ent->suspect->commit->object.sha1),
1833                                ent->suspect->refcnt);
1834                        baa = 1;
1835                }
1836        }
1837        for (ent = sb->ent; ent; ent = ent->next) {
1838                /* Mark the ones that haven't been checked */
1839                if (0 < ent->suspect->refcnt)
1840                        ent->suspect->refcnt = -ent->suspect->refcnt;
1841        }
1842        for (ent = sb->ent; ent; ent = ent->next) {
1843                /*
1844                 * ... then pick each and see if they have the the
1845                 * correct refcnt.
1846                 */
1847                int found;
1848                struct blame_entry *e;
1849                struct origin *suspect = ent->suspect;
1850
1851                if (0 < suspect->refcnt)
1852                        continue;
1853                suspect->refcnt = -suspect->refcnt; /* Unmark */
1854                for (found = 0, e = sb->ent; e; e = e->next) {
1855                        if (e->suspect != suspect)
1856                                continue;
1857                        found++;
1858                }
1859                if (suspect->refcnt != found) {
1860                        fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1861                                ent->suspect->path,
1862                                sha1_to_hex(ent->suspect->commit->object.sha1),
1863                                ent->suspect->refcnt, found);
1864                        baa = 2;
1865                }
1866        }
1867        if (baa) {
1868                int opt = 0160;
1869                find_alignment(sb, &opt);
1870                output(sb, opt);
1871                die("Baa %d!", baa);
1872        }
1873}
1874
1875/*
1876 * Used for the command line parsing; check if the path exists
1877 * in the working tree.
1878 */
1879static int has_path_in_work_tree(const char *path)
1880{
1881        struct stat st;
1882        return !lstat(path, &st);
1883}
1884
1885static unsigned parse_score(const char *arg)
1886{
1887        char *end;
1888        unsigned long score = strtoul(arg, &end, 10);
1889        if (*end)
1890                return 0;
1891        return score;
1892}
1893
1894static const char *add_prefix(const char *prefix, const char *path)
1895{
1896        if (!prefix || !prefix[0])
1897                return path;
1898        return prefix_path(prefix, strlen(prefix), path);
1899}
1900
1901/*
1902 * Parsing of (comma separated) one item in the -L option
1903 */
1904static const char *parse_loc(const char *spec,
1905                             struct scoreboard *sb, long lno,
1906                             long begin, long *ret)
1907{
1908        char *term;
1909        const char *line;
1910        long num;
1911        int reg_error;
1912        regex_t regexp;
1913        regmatch_t match[1];
1914
1915        /* Allow "-L <something>,+20" to mean starting at <something>
1916         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1917         * <something>.
1918         */
1919        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1920                num = strtol(spec + 1, &term, 10);
1921                if (term != spec + 1) {
1922                        if (spec[0] == '-')
1923                                num = 0 - num;
1924                        if (0 < num)
1925                                *ret = begin + num - 2;
1926                        else if (!num)
1927                                *ret = begin;
1928                        else
1929                                *ret = begin + num;
1930                        return term;
1931                }
1932                return spec;
1933        }
1934        num = strtol(spec, &term, 10);
1935        if (term != spec) {
1936                *ret = num;
1937                return term;
1938        }
1939        if (spec[0] != '/')
1940                return spec;
1941
1942        /* it could be a regexp of form /.../ */
1943        for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1944                if (*term == '\\')
1945                        term++;
1946        }
1947        if (*term != '/')
1948                return spec;
1949
1950        /* try [spec+1 .. term-1] as regexp */
1951        *term = 0;
1952        begin--; /* input is in human terms */
1953        line = nth_line(sb, begin);
1954
1955        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1956            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1957                const char *cp = line + match[0].rm_so;
1958                const char *nline;
1959
1960                while (begin++ < lno) {
1961                        nline = nth_line(sb, begin);
1962                        if (line <= cp && cp < nline)
1963                                break;
1964                        line = nline;
1965                }
1966                *ret = begin;
1967                regfree(&regexp);
1968                *term++ = '/';
1969                return term;
1970        }
1971        else {
1972                char errbuf[1024];
1973                regerror(reg_error, &regexp, errbuf, 1024);
1974                die("-L parameter '%s': %s", spec + 1, errbuf);
1975        }
1976}
1977
1978/*
1979 * Parsing of -L option
1980 */
1981static void prepare_blame_range(struct scoreboard *sb,
1982                                const char *bottomtop,
1983                                long lno,
1984                                long *bottom, long *top)
1985{
1986        const char *term;
1987
1988        term = parse_loc(bottomtop, sb, lno, 1, bottom);
1989        if (*term == ',') {
1990                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1991                if (*term)
1992                        usage(blame_usage);
1993        }
1994        if (*term)
1995                usage(blame_usage);
1996}
1997
1998static int git_blame_config(const char *var, const char *value)
1999{
2000        if (!strcmp(var, "blame.showroot")) {
2001                show_root = git_config_bool(var, value);
2002                return 0;
2003        }
2004        if (!strcmp(var, "blame.blankboundary")) {
2005                blank_boundary = git_config_bool(var, value);
2006                return 0;
2007        }
2008        return git_default_config(var, value);
2009}
2010
2011static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
2012{
2013        struct commit *commit;
2014        struct origin *origin;
2015        unsigned char head_sha1[20];
2016        struct strbuf buf;
2017        const char *ident;
2018        time_t now;
2019        int size, len;
2020        struct cache_entry *ce;
2021        unsigned mode;
2022
2023        if (get_sha1("HEAD", head_sha1))
2024                die("No such ref: HEAD");
2025
2026        time(&now);
2027        commit = xcalloc(1, sizeof(*commit));
2028        commit->parents = xcalloc(1, sizeof(*commit->parents));
2029        commit->parents->item = lookup_commit_reference(head_sha1);
2030        commit->object.parsed = 1;
2031        commit->date = now;
2032        commit->object.type = OBJ_COMMIT;
2033
2034        origin = make_origin(commit, path);
2035
2036        strbuf_init(&buf, 0);
2037        if (!contents_from || strcmp("-", contents_from)) {
2038                struct stat st;
2039                const char *read_from;
2040                unsigned long fin_size;
2041
2042                if (contents_from) {
2043                        if (stat(contents_from, &st) < 0)
2044                                die("Cannot stat %s", contents_from);
2045                        read_from = contents_from;
2046                }
2047                else {
2048                        if (lstat(path, &st) < 0)
2049                                die("Cannot lstat %s", path);
2050                        read_from = path;
2051                }
2052                fin_size = xsize_t(st.st_size);
2053                mode = canon_mode(st.st_mode);
2054                switch (st.st_mode & S_IFMT) {
2055                case S_IFREG:
2056                        if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
2057                                die("cannot open or read %s", read_from);
2058                        break;
2059                case S_IFLNK:
2060                        if (readlink(read_from, buf.buf, buf.alloc) != fin_size)
2061                                die("cannot readlink %s", read_from);
2062                        buf.len = fin_size;
2063                        break;
2064                default:
2065                        die("unsupported file type %s", read_from);
2066                }
2067        }
2068        else {
2069                /* Reading from stdin */
2070                contents_from = "standard input";
2071                mode = 0;
2072                if (strbuf_read(&buf, 0, 0) < 0)
2073                        die("read error %s from stdin", strerror(errno));
2074        }
2075        convert_to_git(path, buf.buf, buf.len, &buf);
2076        origin->file.ptr = buf.buf;
2077        origin->file.size = buf.len;
2078        pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
2079        commit->util = origin;
2080
2081        /*
2082         * Read the current index, replace the path entry with
2083         * origin->blob_sha1 without mucking with its mode or type
2084         * bits; we are not going to write this index out -- we just
2085         * want to run "diff-index --cached".
2086         */
2087        discard_cache();
2088        read_cache();
2089
2090        len = strlen(path);
2091        if (!mode) {
2092                int pos = cache_name_pos(path, len);
2093                if (0 <= pos)
2094                        mode = ntohl(active_cache[pos]->ce_mode);
2095                else
2096                        /* Let's not bother reading from HEAD tree */
2097                        mode = S_IFREG | 0644;
2098        }
2099        size = cache_entry_size(len);
2100        ce = xcalloc(1, size);
2101        hashcpy(ce->sha1, origin->blob_sha1);
2102        memcpy(ce->name, path, len);
2103        ce->ce_flags = create_ce_flags(len, 0);
2104        ce->ce_mode = create_ce_mode(mode);
2105        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2106
2107        /*
2108         * We are not going to write this out, so this does not matter
2109         * right now, but someday we might optimize diff-index --cached
2110         * with cache-tree information.
2111         */
2112        cache_tree_invalidate_path(active_cache_tree, path);
2113
2114        commit->buffer = xmalloc(400);
2115        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2116        snprintf(commit->buffer, 400,
2117                "tree 0000000000000000000000000000000000000000\n"
2118                "parent %s\n"
2119                "author %s\n"
2120                "committer %s\n\n"
2121                "Version of %s from %s\n",
2122                sha1_to_hex(head_sha1),
2123                ident, ident, path, contents_from ? contents_from : path);
2124        return commit;
2125}
2126
2127int cmd_blame(int argc, const char **argv, const char *prefix)
2128{
2129        struct rev_info revs;
2130        const char *path;
2131        struct scoreboard sb;
2132        struct origin *o;
2133        struct blame_entry *ent;
2134        int i, seen_dashdash, unk, opt;
2135        long bottom, top, lno;
2136        int output_option = 0;
2137        int show_stats = 0;
2138        const char *revs_file = NULL;
2139        const char *final_commit_name = NULL;
2140        enum object_type type;
2141        const char *bottomtop = NULL;
2142        const char *contents_from = NULL;
2143
2144        cmd_is_annotate = !strcmp(argv[0], "annotate");
2145
2146        git_config(git_blame_config);
2147        save_commit_buffer = 0;
2148
2149        opt = 0;
2150        seen_dashdash = 0;
2151        for (unk = i = 1; i < argc; i++) {
2152                const char *arg = argv[i];
2153                if (*arg != '-')
2154                        break;
2155                else if (!strcmp("-b", arg))
2156                        blank_boundary = 1;
2157                else if (!strcmp("--root", arg))
2158                        show_root = 1;
2159                else if (!strcmp(arg, "--show-stats"))
2160                        show_stats = 1;
2161                else if (!strcmp("-c", arg))
2162                        output_option |= OUTPUT_ANNOTATE_COMPAT;
2163                else if (!strcmp("-t", arg))
2164                        output_option |= OUTPUT_RAW_TIMESTAMP;
2165                else if (!strcmp("-l", arg))
2166                        output_option |= OUTPUT_LONG_OBJECT_NAME;
2167                else if (!strcmp("-s", arg))
2168                        output_option |= OUTPUT_NO_AUTHOR;
2169                else if (!strcmp("-w", arg))
2170                        xdl_opts |= XDF_IGNORE_WHITESPACE;
2171                else if (!strcmp("-S", arg) && ++i < argc)
2172                        revs_file = argv[i];
2173                else if (!prefixcmp(arg, "-M")) {
2174                        opt |= PICKAXE_BLAME_MOVE;
2175                        blame_move_score = parse_score(arg+2);
2176                }
2177                else if (!prefixcmp(arg, "-C")) {
2178                        /*
2179                         * -C enables copy from removed files;
2180                         * -C -C enables copy from existing files, but only
2181                         *       when blaming a new file;
2182                         * -C -C -C enables copy from existing files for
2183                         *          everybody
2184                         */
2185                        if (opt & PICKAXE_BLAME_COPY_HARDER)
2186                                opt |= PICKAXE_BLAME_COPY_HARDEST;
2187                        if (opt & PICKAXE_BLAME_COPY)
2188                                opt |= PICKAXE_BLAME_COPY_HARDER;
2189                        opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2190                        blame_copy_score = parse_score(arg+2);
2191                }
2192                else if (!prefixcmp(arg, "-L")) {
2193                        if (!arg[2]) {
2194                                if (++i >= argc)
2195                                        usage(blame_usage);
2196                                arg = argv[i];
2197                        }
2198                        else
2199                                arg += 2;
2200                        if (bottomtop)
2201                                die("More than one '-L n,m' option given");
2202                        bottomtop = arg;
2203                }
2204                else if (!strcmp("--contents", arg)) {
2205                        if (++i >= argc)
2206                                usage(blame_usage);
2207                        contents_from = argv[i];
2208                }
2209                else if (!strcmp("--incremental", arg))
2210                        incremental = 1;
2211                else if (!strcmp("--score-debug", arg))
2212                        output_option |= OUTPUT_SHOW_SCORE;
2213                else if (!strcmp("-f", arg) ||
2214                         !strcmp("--show-name", arg))
2215                        output_option |= OUTPUT_SHOW_NAME;
2216                else if (!strcmp("-n", arg) ||
2217                         !strcmp("--show-number", arg))
2218                        output_option |= OUTPUT_SHOW_NUMBER;
2219                else if (!strcmp("-p", arg) ||
2220                         !strcmp("--porcelain", arg))
2221                        output_option |= OUTPUT_PORCELAIN;
2222                else if (!strcmp("--", arg)) {
2223                        seen_dashdash = 1;
2224                        i++;
2225                        break;
2226                }
2227                else
2228                        argv[unk++] = arg;
2229        }
2230
2231        if (!blame_move_score)
2232                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2233        if (!blame_copy_score)
2234                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2235
2236        /*
2237         * We have collected options unknown to us in argv[1..unk]
2238         * which are to be passed to revision machinery if we are
2239         * going to do the "bottom" processing.
2240         *
2241         * The remaining are:
2242         *
2243         * (1) if seen_dashdash, its either
2244         *     "-options -- <path>" or
2245         *     "-options -- <path> <rev>".
2246         *     but the latter is allowed only if there is no
2247         *     options that we passed to revision machinery.
2248         *
2249         * (2) otherwise, we may have "--" somewhere later and
2250         *     might be looking at the first one of multiple 'rev'
2251         *     parameters (e.g. " master ^next ^maint -- path").
2252         *     See if there is a dashdash first, and give the
2253         *     arguments before that to revision machinery.
2254         *     After that there must be one 'path'.
2255         *
2256         * (3) otherwise, its one of the three:
2257         *     "-options <path> <rev>"
2258         *     "-options <rev> <path>"
2259         *     "-options <path>"
2260         *     but again the first one is allowed only if
2261         *     there is no options that we passed to revision
2262         *     machinery.
2263         */
2264
2265        if (seen_dashdash) {
2266                /* (1) */
2267                if (argc <= i)
2268                        usage(blame_usage);
2269                path = add_prefix(prefix, argv[i]);
2270                if (i + 1 == argc - 1) {
2271                        if (unk != 1)
2272                                usage(blame_usage);
2273                        argv[unk++] = argv[i + 1];
2274                }
2275                else if (i + 1 != argc)
2276                        /* garbage at end */
2277                        usage(blame_usage);
2278        }
2279        else {
2280                int j;
2281                for (j = i; !seen_dashdash && j < argc; j++)
2282                        if (!strcmp(argv[j], "--"))
2283                                seen_dashdash = j;
2284                if (seen_dashdash) {
2285                        /* (2) */
2286                        if (seen_dashdash + 1 != argc - 1)
2287                                usage(blame_usage);
2288                        path = add_prefix(prefix, argv[seen_dashdash + 1]);
2289                        for (j = i; j < seen_dashdash; j++)
2290                                argv[unk++] = argv[j];
2291                }
2292                else {
2293                        /* (3) */
2294                        if (argc <= i)
2295                                usage(blame_usage);
2296                        path = add_prefix(prefix, argv[i]);
2297                        if (i + 1 == argc - 1) {
2298                                final_commit_name = argv[i + 1];
2299
2300                                /* if (unk == 1) we could be getting
2301                                 * old-style
2302                                 */
2303                                if (unk == 1 && !has_path_in_work_tree(path)) {
2304                                        path = add_prefix(prefix, argv[i + 1]);
2305                                        final_commit_name = argv[i];
2306                                }
2307                        }
2308                        else if (i != argc - 1)
2309                                usage(blame_usage); /* garbage at end */
2310
2311                        setup_work_tree();
2312                        if (!has_path_in_work_tree(path))
2313                                die("cannot stat path %s: %s",
2314                                    path, strerror(errno));
2315                }
2316        }
2317
2318        if (final_commit_name)
2319                argv[unk++] = final_commit_name;
2320
2321        /*
2322         * Now we got rev and path.  We do not want the path pruning
2323         * but we may want "bottom" processing.
2324         */
2325        argv[unk++] = "--"; /* terminate the rev name */
2326        argv[unk] = NULL;
2327
2328        init_revisions(&revs, NULL);
2329        setup_revisions(unk, argv, &revs, NULL);
2330        memset(&sb, 0, sizeof(sb));
2331
2332        /*
2333         * There must be one and only one positive commit in the
2334         * revs->pending array.
2335         */
2336        for (i = 0; i < revs.pending.nr; i++) {
2337                struct object *obj = revs.pending.objects[i].item;
2338                if (obj->flags & UNINTERESTING)
2339                        continue;
2340                while (obj->type == OBJ_TAG)
2341                        obj = deref_tag(obj, NULL, 0);
2342                if (obj->type != OBJ_COMMIT)
2343                        die("Non commit %s?",
2344                            revs.pending.objects[i].name);
2345                if (sb.final)
2346                        die("More than one commit to dig from %s and %s?",
2347                            revs.pending.objects[i].name,
2348                            final_commit_name);
2349                sb.final = (struct commit *) obj;
2350                final_commit_name = revs.pending.objects[i].name;
2351        }
2352
2353        if (!sb.final) {
2354                /*
2355                 * "--not A B -- path" without anything positive;
2356                 * do not default to HEAD, but use the working tree
2357                 * or "--contents".
2358                 */
2359                setup_work_tree();
2360                sb.final = fake_working_tree_commit(path, contents_from);
2361                add_pending_object(&revs, &(sb.final->object), ":");
2362        }
2363        else if (contents_from)
2364                die("Cannot use --contents with final commit object name");
2365
2366        /*
2367         * If we have bottom, this will mark the ancestors of the
2368         * bottom commits we would reach while traversing as
2369         * uninteresting.
2370         */
2371        prepare_revision_walk(&revs);
2372
2373        if (is_null_sha1(sb.final->object.sha1)) {
2374                char *buf;
2375                o = sb.final->util;
2376                buf = xmalloc(o->file.size + 1);
2377                memcpy(buf, o->file.ptr, o->file.size + 1);
2378                sb.final_buf = buf;
2379                sb.final_buf_size = o->file.size;
2380        }
2381        else {
2382                o = get_origin(&sb, sb.final, path);
2383                if (fill_blob_sha1(o))
2384                        die("no such path %s in %s", path, final_commit_name);
2385
2386                sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2387                                              &sb.final_buf_size);
2388                if (!sb.final_buf)
2389                        die("Cannot read blob %s for path %s",
2390                            sha1_to_hex(o->blob_sha1),
2391                            path);
2392        }
2393        num_read_blob++;
2394        lno = prepare_lines(&sb);
2395
2396        bottom = top = 0;
2397        if (bottomtop)
2398                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2399        if (bottom && top && top < bottom) {
2400                long tmp;
2401                tmp = top; top = bottom; bottom = tmp;
2402        }
2403        if (bottom < 1)
2404                bottom = 1;
2405        if (top < 1)
2406                top = lno;
2407        bottom--;
2408        if (lno < top)
2409                die("file %s has only %lu lines", path, lno);
2410
2411        ent = xcalloc(1, sizeof(*ent));
2412        ent->lno = bottom;
2413        ent->num_lines = top - bottom;
2414        ent->suspect = o;
2415        ent->s_lno = bottom;
2416
2417        sb.ent = ent;
2418        sb.path = path;
2419
2420        if (revs_file && read_ancestry(revs_file))
2421                die("reading graft file %s failed: %s",
2422                    revs_file, strerror(errno));
2423
2424        read_mailmap(&mailmap, ".mailmap", NULL);
2425
2426        if (!incremental)
2427                setup_pager();
2428
2429        assign_blame(&sb, &revs, opt);
2430
2431        if (incremental)
2432                return 0;
2433
2434        coalesce(&sb);
2435
2436        if (!(output_option & OUTPUT_PORCELAIN))
2437                find_alignment(&sb, &output_option);
2438
2439        output(&sb, output_option);
2440        free((void *)sb.final_buf);
2441        for (ent = sb.ent; ent; ) {
2442                struct blame_entry *e = ent->next;
2443                free(ent);
2444                ent = e;
2445        }
2446
2447        if (show_stats) {
2448                printf("num read blob: %d\n", num_read_blob);
2449                printf("num get patch: %d\n", num_get_patch);
2450                printf("num commits: %d\n", num_commits);
2451        }
2452        return 0;
2453}