builtin-blame.con commit branch: fix segfault when resolving an invalid HEAD (078f838)
   1/*
   2 * Pickaxe
   3 *
   4 * Copyright (c) 2006, Junio C Hamano
   5 */
   6
   7#include "cache.h"
   8#include "builtin.h"
   9#include "blob.h"
  10#include "commit.h"
  11#include "tag.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "revision.h"
  16#include "quote.h"
  17#include "xdiff-interface.h"
  18#include "cache-tree.h"
  19
  20static char blame_usage[] =
  21"git-blame [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [--contents <filename>] [--incremental] [commit] [--] file\n"
  22"  -c                  Use the same output mode as git-annotate (Default: off)\n"
  23"  -b                  Show blank SHA-1 for boundary commits (Default: off)\n"
  24"  -l                  Show long commit SHA1 (Default: off)\n"
  25"  --root              Do not treat root commits as boundaries (Default: off)\n"
  26"  -t                  Show raw timestamp (Default: off)\n"
  27"  -f, --show-name     Show original filename (Default: auto)\n"
  28"  -n, --show-number   Show original linenumber (Default: off)\n"
  29"  -p, --porcelain     Show in a format designed for machine consumption\n"
  30"  -L n,m              Process only line range n,m, counting from 1\n"
  31"  -M, -C              Find line movements within and across files\n"
  32"  --incremental       Show blame entries as we find them, incrementally\n"
  33"  --contents file     Use <file>'s contents as the final image\n"
  34"  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
  35
  36static int longest_file;
  37static int longest_author;
  38static int max_orig_digits;
  39static int max_digits;
  40static int max_score_digits;
  41static int show_root;
  42static int blank_boundary;
  43static int incremental;
  44static int cmd_is_annotate;
  45
  46#ifndef DEBUG
  47#define DEBUG 0
  48#endif
  49
  50/* stats */
  51static int num_read_blob;
  52static int num_get_patch;
  53static int num_commits;
  54
  55#define PICKAXE_BLAME_MOVE              01
  56#define PICKAXE_BLAME_COPY              02
  57#define PICKAXE_BLAME_COPY_HARDER       04
  58#define PICKAXE_BLAME_COPY_HARDEST      010
  59
  60/*
  61 * blame for a blame_entry with score lower than these thresholds
  62 * is not passed to the parent using move/copy logic.
  63 */
  64static unsigned blame_move_score;
  65static unsigned blame_copy_score;
  66#define BLAME_DEFAULT_MOVE_SCORE        20
  67#define BLAME_DEFAULT_COPY_SCORE        40
  68
  69/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  70#define METAINFO_SHOWN          (1u<<12)
  71#define MORE_THAN_ONE_PATH      (1u<<13)
  72
  73/*
  74 * One blob in a commit that is being suspected
  75 */
  76struct origin {
  77        int refcnt;
  78        struct commit *commit;
  79        mmfile_t file;
  80        unsigned char blob_sha1[20];
  81        char path[FLEX_ARRAY];
  82};
  83
  84/*
  85 * Given an origin, prepare mmfile_t structure to be used by the
  86 * diff machinery
  87 */
  88static char *fill_origin_blob(struct origin *o, mmfile_t *file)
  89{
  90        if (!o->file.ptr) {
  91                enum object_type type;
  92                num_read_blob++;
  93                file->ptr = read_sha1_file(o->blob_sha1, &type,
  94                                           (unsigned long *)(&(file->size)));
  95                o->file = *file;
  96        }
  97        else
  98                *file = o->file;
  99        return file->ptr;
 100}
 101
 102/*
 103 * Origin is refcounted and usually we keep the blob contents to be
 104 * reused.
 105 */
 106static inline struct origin *origin_incref(struct origin *o)
 107{
 108        if (o)
 109                o->refcnt++;
 110        return o;
 111}
 112
 113static void origin_decref(struct origin *o)
 114{
 115        if (o && --o->refcnt <= 0) {
 116                if (o->file.ptr)
 117                        free(o->file.ptr);
 118                memset(o, 0, sizeof(*o));
 119                free(o);
 120        }
 121}
 122
 123/*
 124 * Each group of lines is described by a blame_entry; it can be split
 125 * as we pass blame to the parents.  They form a linked list in the
 126 * scoreboard structure, sorted by the target line number.
 127 */
 128struct blame_entry {
 129        struct blame_entry *prev;
 130        struct blame_entry *next;
 131
 132        /* the first line of this group in the final image;
 133         * internally all line numbers are 0 based.
 134         */
 135        int lno;
 136
 137        /* how many lines this group has */
 138        int num_lines;
 139
 140        /* the commit that introduced this group into the final image */
 141        struct origin *suspect;
 142
 143        /* true if the suspect is truly guilty; false while we have not
 144         * checked if the group came from one of its parents.
 145         */
 146        char guilty;
 147
 148        /* the line number of the first line of this group in the
 149         * suspect's file; internally all line numbers are 0 based.
 150         */
 151        int s_lno;
 152
 153        /* how significant this entry is -- cached to avoid
 154         * scanning the lines over and over.
 155         */
 156        unsigned score;
 157};
 158
 159/*
 160 * The current state of the blame assignment.
 161 */
 162struct scoreboard {
 163        /* the final commit (i.e. where we started digging from) */
 164        struct commit *final;
 165
 166        const char *path;
 167
 168        /*
 169         * The contents in the final image.
 170         * Used by many functions to obtain contents of the nth line,
 171         * indexed with scoreboard.lineno[blame_entry.lno].
 172         */
 173        const char *final_buf;
 174        unsigned long final_buf_size;
 175
 176        /* linked list of blames */
 177        struct blame_entry *ent;
 178
 179        /* look-up a line in the final buffer */
 180        int num_lines;
 181        int *lineno;
 182};
 183
 184static inline int same_suspect(struct origin *a, struct origin *b)
 185{
 186        if (a == b)
 187                return 1;
 188        if (a->commit != b->commit)
 189                return 0;
 190        return !strcmp(a->path, b->path);
 191}
 192
 193static void sanity_check_refcnt(struct scoreboard *);
 194
 195/*
 196 * If two blame entries that are next to each other came from
 197 * contiguous lines in the same origin (i.e. <commit, path> pair),
 198 * merge them together.
 199 */
 200static void coalesce(struct scoreboard *sb)
 201{
 202        struct blame_entry *ent, *next;
 203
 204        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 205                if (same_suspect(ent->suspect, next->suspect) &&
 206                    ent->guilty == next->guilty &&
 207                    ent->s_lno + ent->num_lines == next->s_lno) {
 208                        ent->num_lines += next->num_lines;
 209                        ent->next = next->next;
 210                        if (ent->next)
 211                                ent->next->prev = ent;
 212                        origin_decref(next->suspect);
 213                        free(next);
 214                        ent->score = 0;
 215                        next = ent; /* again */
 216                }
 217        }
 218
 219        if (DEBUG) /* sanity */
 220                sanity_check_refcnt(sb);
 221}
 222
 223/*
 224 * Given a commit and a path in it, create a new origin structure.
 225 * The callers that add blame to the scoreboard should use
 226 * get_origin() to obtain shared, refcounted copy instead of calling
 227 * this function directly.
 228 */
 229static struct origin *make_origin(struct commit *commit, const char *path)
 230{
 231        struct origin *o;
 232        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 233        o->commit = commit;
 234        o->refcnt = 1;
 235        strcpy(o->path, path);
 236        return o;
 237}
 238
 239/*
 240 * Locate an existing origin or create a new one.
 241 */
 242static struct origin *get_origin(struct scoreboard *sb,
 243                                 struct commit *commit,
 244                                 const char *path)
 245{
 246        struct blame_entry *e;
 247
 248        for (e = sb->ent; e; e = e->next) {
 249                if (e->suspect->commit == commit &&
 250                    !strcmp(e->suspect->path, path))
 251                        return origin_incref(e->suspect);
 252        }
 253        return make_origin(commit, path);
 254}
 255
 256/*
 257 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 258 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 259 * for an origin is also used to pass the blame for the entire file to
 260 * the parent to detect the case where a child's blob is identical to
 261 * that of its parent's.
 262 */
 263static int fill_blob_sha1(struct origin *origin)
 264{
 265        unsigned mode;
 266
 267        if (!is_null_sha1(origin->blob_sha1))
 268                return 0;
 269        if (get_tree_entry(origin->commit->object.sha1,
 270                           origin->path,
 271                           origin->blob_sha1, &mode))
 272                goto error_out;
 273        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 274                goto error_out;
 275        return 0;
 276 error_out:
 277        hashclr(origin->blob_sha1);
 278        return -1;
 279}
 280
 281/*
 282 * We have an origin -- check if the same path exists in the
 283 * parent and return an origin structure to represent it.
 284 */
 285static struct origin *find_origin(struct scoreboard *sb,
 286                                  struct commit *parent,
 287                                  struct origin *origin)
 288{
 289        struct origin *porigin = NULL;
 290        struct diff_options diff_opts;
 291        const char *paths[2];
 292
 293        if (parent->util) {
 294                /*
 295                 * Each commit object can cache one origin in that
 296                 * commit.  This is a freestanding copy of origin and
 297                 * not refcounted.
 298                 */
 299                struct origin *cached = parent->util;
 300                if (!strcmp(cached->path, origin->path)) {
 301                        /*
 302                         * The same path between origin and its parent
 303                         * without renaming -- the most common case.
 304                         */
 305                        porigin = get_origin(sb, parent, cached->path);
 306
 307                        /*
 308                         * If the origin was newly created (i.e. get_origin
 309                         * would call make_origin if none is found in the
 310                         * scoreboard), it does not know the blob_sha1,
 311                         * so copy it.  Otherwise porigin was in the
 312                         * scoreboard and already knows blob_sha1.
 313                         */
 314                        if (porigin->refcnt == 1)
 315                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 316                        return porigin;
 317                }
 318                /* otherwise it was not very useful; free it */
 319                free(parent->util);
 320                parent->util = NULL;
 321        }
 322
 323        /* See if the origin->path is different between parent
 324         * and origin first.  Most of the time they are the
 325         * same and diff-tree is fairly efficient about this.
 326         */
 327        diff_setup(&diff_opts);
 328        diff_opts.recursive = 1;
 329        diff_opts.detect_rename = 0;
 330        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 331        paths[0] = origin->path;
 332        paths[1] = NULL;
 333
 334        diff_tree_setup_paths(paths, &diff_opts);
 335        if (diff_setup_done(&diff_opts) < 0)
 336                die("diff-setup");
 337
 338        if (is_null_sha1(origin->commit->object.sha1))
 339                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 340        else
 341                diff_tree_sha1(parent->tree->object.sha1,
 342                               origin->commit->tree->object.sha1,
 343                               "", &diff_opts);
 344        diffcore_std(&diff_opts);
 345
 346        /* It is either one entry that says "modified", or "created",
 347         * or nothing.
 348         */
 349        if (!diff_queued_diff.nr) {
 350                /* The path is the same as parent */
 351                porigin = get_origin(sb, parent, origin->path);
 352                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 353        }
 354        else if (diff_queued_diff.nr != 1)
 355                die("internal error in blame::find_origin");
 356        else {
 357                struct diff_filepair *p = diff_queued_diff.queue[0];
 358                switch (p->status) {
 359                default:
 360                        die("internal error in blame::find_origin (%c)",
 361                            p->status);
 362                case 'M':
 363                        porigin = get_origin(sb, parent, origin->path);
 364                        hashcpy(porigin->blob_sha1, p->one->sha1);
 365                        break;
 366                case 'A':
 367                case 'T':
 368                        /* Did not exist in parent, or type changed */
 369                        break;
 370                }
 371        }
 372        diff_flush(&diff_opts);
 373        if (porigin) {
 374                /*
 375                 * Create a freestanding copy that is not part of
 376                 * the refcounted origin found in the scoreboard, and
 377                 * cache it in the commit.
 378                 */
 379                struct origin *cached;
 380
 381                cached = make_origin(porigin->commit, porigin->path);
 382                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 383                parent->util = cached;
 384        }
 385        return porigin;
 386}
 387
 388/*
 389 * We have an origin -- find the path that corresponds to it in its
 390 * parent and return an origin structure to represent it.
 391 */
 392static struct origin *find_rename(struct scoreboard *sb,
 393                                  struct commit *parent,
 394                                  struct origin *origin)
 395{
 396        struct origin *porigin = NULL;
 397        struct diff_options diff_opts;
 398        int i;
 399        const char *paths[2];
 400
 401        diff_setup(&diff_opts);
 402        diff_opts.recursive = 1;
 403        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 404        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 405        diff_opts.single_follow = origin->path;
 406        paths[0] = NULL;
 407        diff_tree_setup_paths(paths, &diff_opts);
 408        if (diff_setup_done(&diff_opts) < 0)
 409                die("diff-setup");
 410
 411        if (is_null_sha1(origin->commit->object.sha1))
 412                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 413        else
 414                diff_tree_sha1(parent->tree->object.sha1,
 415                               origin->commit->tree->object.sha1,
 416                               "", &diff_opts);
 417        diffcore_std(&diff_opts);
 418
 419        for (i = 0; i < diff_queued_diff.nr; i++) {
 420                struct diff_filepair *p = diff_queued_diff.queue[i];
 421                if ((p->status == 'R' || p->status == 'C') &&
 422                    !strcmp(p->two->path, origin->path)) {
 423                        porigin = get_origin(sb, parent, p->one->path);
 424                        hashcpy(porigin->blob_sha1, p->one->sha1);
 425                        break;
 426                }
 427        }
 428        diff_flush(&diff_opts);
 429        return porigin;
 430}
 431
 432/*
 433 * Parsing of patch chunks...
 434 */
 435struct chunk {
 436        /* line number in postimage; up to but not including this
 437         * line is the same as preimage
 438         */
 439        int same;
 440
 441        /* preimage line number after this chunk */
 442        int p_next;
 443
 444        /* postimage line number after this chunk */
 445        int t_next;
 446};
 447
 448struct patch {
 449        struct chunk *chunks;
 450        int num;
 451};
 452
 453struct blame_diff_state {
 454        struct xdiff_emit_state xm;
 455        struct patch *ret;
 456        unsigned hunk_post_context;
 457        unsigned hunk_in_pre_context : 1;
 458};
 459
 460static void process_u_diff(void *state_, char *line, unsigned long len)
 461{
 462        struct blame_diff_state *state = state_;
 463        struct chunk *chunk;
 464        int off1, off2, len1, len2, num;
 465
 466        num = state->ret->num;
 467        if (len < 4 || line[0] != '@' || line[1] != '@') {
 468                if (state->hunk_in_pre_context && line[0] == ' ')
 469                        state->ret->chunks[num - 1].same++;
 470                else {
 471                        state->hunk_in_pre_context = 0;
 472                        if (line[0] == ' ')
 473                                state->hunk_post_context++;
 474                        else
 475                                state->hunk_post_context = 0;
 476                }
 477                return;
 478        }
 479
 480        if (num && state->hunk_post_context) {
 481                chunk = &state->ret->chunks[num - 1];
 482                chunk->p_next -= state->hunk_post_context;
 483                chunk->t_next -= state->hunk_post_context;
 484        }
 485        state->ret->num = ++num;
 486        state->ret->chunks = xrealloc(state->ret->chunks,
 487                                      sizeof(struct chunk) * num);
 488        chunk = &state->ret->chunks[num - 1];
 489        if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
 490                state->ret->num--;
 491                return;
 492        }
 493
 494        /* Line numbers in patch output are one based. */
 495        off1--;
 496        off2--;
 497
 498        chunk->same = len2 ? off2 : (off2 + 1);
 499
 500        chunk->p_next = off1 + (len1 ? len1 : 1);
 501        chunk->t_next = chunk->same + len2;
 502        state->hunk_in_pre_context = 1;
 503        state->hunk_post_context = 0;
 504}
 505
 506static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
 507                                    int context)
 508{
 509        struct blame_diff_state state;
 510        xpparam_t xpp;
 511        xdemitconf_t xecfg;
 512        xdemitcb_t ecb;
 513
 514        xpp.flags = XDF_NEED_MINIMAL;
 515        xecfg.ctxlen = context;
 516        xecfg.flags = 0;
 517        ecb.outf = xdiff_outf;
 518        ecb.priv = &state;
 519        memset(&state, 0, sizeof(state));
 520        state.xm.consume = process_u_diff;
 521        state.ret = xmalloc(sizeof(struct patch));
 522        state.ret->chunks = NULL;
 523        state.ret->num = 0;
 524
 525        xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
 526
 527        if (state.ret->num) {
 528                struct chunk *chunk;
 529                chunk = &state.ret->chunks[state.ret->num - 1];
 530                chunk->p_next -= state.hunk_post_context;
 531                chunk->t_next -= state.hunk_post_context;
 532        }
 533        return state.ret;
 534}
 535
 536/*
 537 * Run diff between two origins and grab the patch output, so that
 538 * we can pass blame for lines origin is currently suspected for
 539 * to its parent.
 540 */
 541static struct patch *get_patch(struct origin *parent, struct origin *origin)
 542{
 543        mmfile_t file_p, file_o;
 544        struct patch *patch;
 545
 546        fill_origin_blob(parent, &file_p);
 547        fill_origin_blob(origin, &file_o);
 548        if (!file_p.ptr || !file_o.ptr)
 549                return NULL;
 550        patch = compare_buffer(&file_p, &file_o, 0);
 551        num_get_patch++;
 552        return patch;
 553}
 554
 555static void free_patch(struct patch *p)
 556{
 557        free(p->chunks);
 558        free(p);
 559}
 560
 561/*
 562 * Link in a new blame entry to the scoreboard.  Entries that cover the
 563 * same line range have been removed from the scoreboard previously.
 564 */
 565static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 566{
 567        struct blame_entry *ent, *prev = NULL;
 568
 569        origin_incref(e->suspect);
 570
 571        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 572                prev = ent;
 573
 574        /* prev, if not NULL, is the last one that is below e */
 575        e->prev = prev;
 576        if (prev) {
 577                e->next = prev->next;
 578                prev->next = e;
 579        }
 580        else {
 581                e->next = sb->ent;
 582                sb->ent = e;
 583        }
 584        if (e->next)
 585                e->next->prev = e;
 586}
 587
 588/*
 589 * src typically is on-stack; we want to copy the information in it to
 590 * an malloced blame_entry that is already on the linked list of the
 591 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 592 * gains one.
 593 */
 594static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 595{
 596        struct blame_entry *p, *n;
 597
 598        p = dst->prev;
 599        n = dst->next;
 600        origin_incref(src->suspect);
 601        origin_decref(dst->suspect);
 602        memcpy(dst, src, sizeof(*src));
 603        dst->prev = p;
 604        dst->next = n;
 605        dst->score = 0;
 606}
 607
 608static const char *nth_line(struct scoreboard *sb, int lno)
 609{
 610        return sb->final_buf + sb->lineno[lno];
 611}
 612
 613/*
 614 * It is known that lines between tlno to same came from parent, and e
 615 * has an overlap with that range.  it also is known that parent's
 616 * line plno corresponds to e's line tlno.
 617 *
 618 *                <---- e ----->
 619 *                   <------>
 620 *                   <------------>
 621 *             <------------>
 622 *             <------------------>
 623 *
 624 * Split e into potentially three parts; before this chunk, the chunk
 625 * to be blamed for the parent, and after that portion.
 626 */
 627static void split_overlap(struct blame_entry *split,
 628                          struct blame_entry *e,
 629                          int tlno, int plno, int same,
 630                          struct origin *parent)
 631{
 632        int chunk_end_lno;
 633        memset(split, 0, sizeof(struct blame_entry [3]));
 634
 635        if (e->s_lno < tlno) {
 636                /* there is a pre-chunk part not blamed on parent */
 637                split[0].suspect = origin_incref(e->suspect);
 638                split[0].lno = e->lno;
 639                split[0].s_lno = e->s_lno;
 640                split[0].num_lines = tlno - e->s_lno;
 641                split[1].lno = e->lno + tlno - e->s_lno;
 642                split[1].s_lno = plno;
 643        }
 644        else {
 645                split[1].lno = e->lno;
 646                split[1].s_lno = plno + (e->s_lno - tlno);
 647        }
 648
 649        if (same < e->s_lno + e->num_lines) {
 650                /* there is a post-chunk part not blamed on parent */
 651                split[2].suspect = origin_incref(e->suspect);
 652                split[2].lno = e->lno + (same - e->s_lno);
 653                split[2].s_lno = e->s_lno + (same - e->s_lno);
 654                split[2].num_lines = e->s_lno + e->num_lines - same;
 655                chunk_end_lno = split[2].lno;
 656        }
 657        else
 658                chunk_end_lno = e->lno + e->num_lines;
 659        split[1].num_lines = chunk_end_lno - split[1].lno;
 660
 661        /*
 662         * if it turns out there is nothing to blame the parent for,
 663         * forget about the splitting.  !split[1].suspect signals this.
 664         */
 665        if (split[1].num_lines < 1)
 666                return;
 667        split[1].suspect = origin_incref(parent);
 668}
 669
 670/*
 671 * split_overlap() divided an existing blame e into up to three parts
 672 * in split.  Adjust the linked list of blames in the scoreboard to
 673 * reflect the split.
 674 */
 675static void split_blame(struct scoreboard *sb,
 676                        struct blame_entry *split,
 677                        struct blame_entry *e)
 678{
 679        struct blame_entry *new_entry;
 680
 681        if (split[0].suspect && split[2].suspect) {
 682                /* The first part (reuse storage for the existing entry e) */
 683                dup_entry(e, &split[0]);
 684
 685                /* The last part -- me */
 686                new_entry = xmalloc(sizeof(*new_entry));
 687                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 688                add_blame_entry(sb, new_entry);
 689
 690                /* ... and the middle part -- parent */
 691                new_entry = xmalloc(sizeof(*new_entry));
 692                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 693                add_blame_entry(sb, new_entry);
 694        }
 695        else if (!split[0].suspect && !split[2].suspect)
 696                /*
 697                 * The parent covers the entire area; reuse storage for
 698                 * e and replace it with the parent.
 699                 */
 700                dup_entry(e, &split[1]);
 701        else if (split[0].suspect) {
 702                /* me and then parent */
 703                dup_entry(e, &split[0]);
 704
 705                new_entry = xmalloc(sizeof(*new_entry));
 706                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 707                add_blame_entry(sb, new_entry);
 708        }
 709        else {
 710                /* parent and then me */
 711                dup_entry(e, &split[1]);
 712
 713                new_entry = xmalloc(sizeof(*new_entry));
 714                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 715                add_blame_entry(sb, new_entry);
 716        }
 717
 718        if (DEBUG) { /* sanity */
 719                struct blame_entry *ent;
 720                int lno = sb->ent->lno, corrupt = 0;
 721
 722                for (ent = sb->ent; ent; ent = ent->next) {
 723                        if (lno != ent->lno)
 724                                corrupt = 1;
 725                        if (ent->s_lno < 0)
 726                                corrupt = 1;
 727                        lno += ent->num_lines;
 728                }
 729                if (corrupt) {
 730                        lno = sb->ent->lno;
 731                        for (ent = sb->ent; ent; ent = ent->next) {
 732                                printf("L %8d l %8d n %8d\n",
 733                                       lno, ent->lno, ent->num_lines);
 734                                lno = ent->lno + ent->num_lines;
 735                        }
 736                        die("oops");
 737                }
 738        }
 739}
 740
 741/*
 742 * After splitting the blame, the origins used by the
 743 * on-stack blame_entry should lose one refcnt each.
 744 */
 745static void decref_split(struct blame_entry *split)
 746{
 747        int i;
 748
 749        for (i = 0; i < 3; i++)
 750                origin_decref(split[i].suspect);
 751}
 752
 753/*
 754 * Helper for blame_chunk().  blame_entry e is known to overlap with
 755 * the patch hunk; split it and pass blame to the parent.
 756 */
 757static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 758                          int tlno, int plno, int same,
 759                          struct origin *parent)
 760{
 761        struct blame_entry split[3];
 762
 763        split_overlap(split, e, tlno, plno, same, parent);
 764        if (split[1].suspect)
 765                split_blame(sb, split, e);
 766        decref_split(split);
 767}
 768
 769/*
 770 * Find the line number of the last line the target is suspected for.
 771 */
 772static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 773{
 774        struct blame_entry *e;
 775        int last_in_target = -1;
 776
 777        for (e = sb->ent; e; e = e->next) {
 778                if (e->guilty || !same_suspect(e->suspect, target))
 779                        continue;
 780                if (last_in_target < e->s_lno + e->num_lines)
 781                        last_in_target = e->s_lno + e->num_lines;
 782        }
 783        return last_in_target;
 784}
 785
 786/*
 787 * Process one hunk from the patch between the current suspect for
 788 * blame_entry e and its parent.  Find and split the overlap, and
 789 * pass blame to the overlapping part to the parent.
 790 */
 791static void blame_chunk(struct scoreboard *sb,
 792                        int tlno, int plno, int same,
 793                        struct origin *target, struct origin *parent)
 794{
 795        struct blame_entry *e;
 796
 797        for (e = sb->ent; e; e = e->next) {
 798                if (e->guilty || !same_suspect(e->suspect, target))
 799                        continue;
 800                if (same <= e->s_lno)
 801                        continue;
 802                if (tlno < e->s_lno + e->num_lines)
 803                        blame_overlap(sb, e, tlno, plno, same, parent);
 804        }
 805}
 806
 807/*
 808 * We are looking at the origin 'target' and aiming to pass blame
 809 * for the lines it is suspected to its parent.  Run diff to find
 810 * which lines came from parent and pass blame for them.
 811 */
 812static int pass_blame_to_parent(struct scoreboard *sb,
 813                                struct origin *target,
 814                                struct origin *parent)
 815{
 816        int i, last_in_target, plno, tlno;
 817        struct patch *patch;
 818
 819        last_in_target = find_last_in_target(sb, target);
 820        if (last_in_target < 0)
 821                return 1; /* nothing remains for this target */
 822
 823        patch = get_patch(parent, target);
 824        plno = tlno = 0;
 825        for (i = 0; i < patch->num; i++) {
 826                struct chunk *chunk = &patch->chunks[i];
 827
 828                blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 829                plno = chunk->p_next;
 830                tlno = chunk->t_next;
 831        }
 832        /* The rest (i.e. anything after tlno) are the same as the parent */
 833        blame_chunk(sb, tlno, plno, last_in_target, target, parent);
 834
 835        free_patch(patch);
 836        return 0;
 837}
 838
 839/*
 840 * The lines in blame_entry after splitting blames many times can become
 841 * very small and trivial, and at some point it becomes pointless to
 842 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 843 * ordinary C program, and it is not worth to say it was copied from
 844 * totally unrelated file in the parent.
 845 *
 846 * Compute how trivial the lines in the blame_entry are.
 847 */
 848static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 849{
 850        unsigned score;
 851        const char *cp, *ep;
 852
 853        if (e->score)
 854                return e->score;
 855
 856        score = 1;
 857        cp = nth_line(sb, e->lno);
 858        ep = nth_line(sb, e->lno + e->num_lines);
 859        while (cp < ep) {
 860                unsigned ch = *((unsigned char *)cp);
 861                if (isalnum(ch))
 862                        score++;
 863                cp++;
 864        }
 865        e->score = score;
 866        return score;
 867}
 868
 869/*
 870 * best_so_far[] and this[] are both a split of an existing blame_entry
 871 * that passes blame to the parent.  Maintain best_so_far the best split
 872 * so far, by comparing this and best_so_far and copying this into
 873 * bst_so_far as needed.
 874 */
 875static void copy_split_if_better(struct scoreboard *sb,
 876                                 struct blame_entry *best_so_far,
 877                                 struct blame_entry *this)
 878{
 879        int i;
 880
 881        if (!this[1].suspect)
 882                return;
 883        if (best_so_far[1].suspect) {
 884                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 885                        return;
 886        }
 887
 888        for (i = 0; i < 3; i++)
 889                origin_incref(this[i].suspect);
 890        decref_split(best_so_far);
 891        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 892}
 893
 894/*
 895 * We are looking at a part of the final image represented by
 896 * ent (tlno and same are offset by ent->s_lno).
 897 * tlno is where we are looking at in the final image.
 898 * up to (but not including) same match preimage.
 899 * plno is where we are looking at in the preimage.
 900 *
 901 * <-------------- final image ---------------------->
 902 *       <------ent------>
 903 *         ^tlno ^same
 904 *    <---------preimage----->
 905 *         ^plno
 906 *
 907 * All line numbers are 0-based.
 908 */
 909static void handle_split(struct scoreboard *sb,
 910                         struct blame_entry *ent,
 911                         int tlno, int plno, int same,
 912                         struct origin *parent,
 913                         struct blame_entry *split)
 914{
 915        if (ent->num_lines <= tlno)
 916                return;
 917        if (tlno < same) {
 918                struct blame_entry this[3];
 919                tlno += ent->s_lno;
 920                same += ent->s_lno;
 921                split_overlap(this, ent, tlno, plno, same, parent);
 922                copy_split_if_better(sb, split, this);
 923                decref_split(this);
 924        }
 925}
 926
 927/*
 928 * Find the lines from parent that are the same as ent so that
 929 * we can pass blames to it.  file_p has the blob contents for
 930 * the parent.
 931 */
 932static void find_copy_in_blob(struct scoreboard *sb,
 933                              struct blame_entry *ent,
 934                              struct origin *parent,
 935                              struct blame_entry *split,
 936                              mmfile_t *file_p)
 937{
 938        const char *cp;
 939        int cnt;
 940        mmfile_t file_o;
 941        struct patch *patch;
 942        int i, plno, tlno;
 943
 944        /*
 945         * Prepare mmfile that contains only the lines in ent.
 946         */
 947        cp = nth_line(sb, ent->lno);
 948        file_o.ptr = (char*) cp;
 949        cnt = ent->num_lines;
 950
 951        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 952                if (*cp++ == '\n')
 953                        cnt--;
 954        }
 955        file_o.size = cp - file_o.ptr;
 956
 957        patch = compare_buffer(file_p, &file_o, 1);
 958
 959        /*
 960         * file_o is a part of final image we are annotating.
 961         * file_p partially may match that image.
 962         */
 963        memset(split, 0, sizeof(struct blame_entry [3]));
 964        plno = tlno = 0;
 965        for (i = 0; i < patch->num; i++) {
 966                struct chunk *chunk = &patch->chunks[i];
 967
 968                handle_split(sb, ent, tlno, plno, chunk->same, parent, split);
 969                plno = chunk->p_next;
 970                tlno = chunk->t_next;
 971        }
 972        /* remainder, if any, all match the preimage */
 973        handle_split(sb, ent, tlno, plno, ent->num_lines, parent, split);
 974        free_patch(patch);
 975}
 976
 977/*
 978 * See if lines currently target is suspected for can be attributed to
 979 * parent.
 980 */
 981static int find_move_in_parent(struct scoreboard *sb,
 982                               struct origin *target,
 983                               struct origin *parent)
 984{
 985        int last_in_target, made_progress;
 986        struct blame_entry *e, split[3];
 987        mmfile_t file_p;
 988
 989        last_in_target = find_last_in_target(sb, target);
 990        if (last_in_target < 0)
 991                return 1; /* nothing remains for this target */
 992
 993        fill_origin_blob(parent, &file_p);
 994        if (!file_p.ptr)
 995                return 0;
 996
 997        made_progress = 1;
 998        while (made_progress) {
 999                made_progress = 0;
1000                for (e = sb->ent; e; e = e->next) {
1001                        if (e->guilty || !same_suspect(e->suspect, target))
1002                                continue;
1003                        find_copy_in_blob(sb, e, parent, split, &file_p);
1004                        if (split[1].suspect &&
1005                            blame_move_score < ent_score(sb, &split[1])) {
1006                                split_blame(sb, split, e);
1007                                made_progress = 1;
1008                        }
1009                        decref_split(split);
1010                }
1011        }
1012        return 0;
1013}
1014
1015struct blame_list {
1016        struct blame_entry *ent;
1017        struct blame_entry split[3];
1018};
1019
1020/*
1021 * Count the number of entries the target is suspected for,
1022 * and prepare a list of entry and the best split.
1023 */
1024static struct blame_list *setup_blame_list(struct scoreboard *sb,
1025                                           struct origin *target,
1026                                           int *num_ents_p)
1027{
1028        struct blame_entry *e;
1029        int num_ents, i;
1030        struct blame_list *blame_list = NULL;
1031
1032        for (e = sb->ent, num_ents = 0; e; e = e->next)
1033                if (!e->guilty && same_suspect(e->suspect, target))
1034                        num_ents++;
1035        if (num_ents) {
1036                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1037                for (e = sb->ent, i = 0; e; e = e->next)
1038                        if (!e->guilty && same_suspect(e->suspect, target))
1039                                blame_list[i++].ent = e;
1040        }
1041        *num_ents_p = num_ents;
1042        return blame_list;
1043}
1044
1045/*
1046 * For lines target is suspected for, see if we can find code movement
1047 * across file boundary from the parent commit.  porigin is the path
1048 * in the parent we already tried.
1049 */
1050static int find_copy_in_parent(struct scoreboard *sb,
1051                               struct origin *target,
1052                               struct commit *parent,
1053                               struct origin *porigin,
1054                               int opt)
1055{
1056        struct diff_options diff_opts;
1057        const char *paths[1];
1058        int i, j;
1059        int retval;
1060        struct blame_list *blame_list;
1061        int num_ents;
1062
1063        blame_list = setup_blame_list(sb, target, &num_ents);
1064        if (!blame_list)
1065                return 1; /* nothing remains for this target */
1066
1067        diff_setup(&diff_opts);
1068        diff_opts.recursive = 1;
1069        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1070
1071        paths[0] = NULL;
1072        diff_tree_setup_paths(paths, &diff_opts);
1073        if (diff_setup_done(&diff_opts) < 0)
1074                die("diff-setup");
1075
1076        /* Try "find copies harder" on new path if requested;
1077         * we do not want to use diffcore_rename() actually to
1078         * match things up; find_copies_harder is set only to
1079         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1080         * and this code needs to be after diff_setup_done(), which
1081         * usually makes find-copies-harder imply copy detection.
1082         */
1083        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1084            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1085                && (!porigin || strcmp(target->path, porigin->path))))
1086                diff_opts.find_copies_harder = 1;
1087
1088        if (is_null_sha1(target->commit->object.sha1))
1089                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1090        else
1091                diff_tree_sha1(parent->tree->object.sha1,
1092                               target->commit->tree->object.sha1,
1093                               "", &diff_opts);
1094
1095        if (!diff_opts.find_copies_harder)
1096                diffcore_std(&diff_opts);
1097
1098        retval = 0;
1099        while (1) {
1100                int made_progress = 0;
1101
1102                for (i = 0; i < diff_queued_diff.nr; i++) {
1103                        struct diff_filepair *p = diff_queued_diff.queue[i];
1104                        struct origin *norigin;
1105                        mmfile_t file_p;
1106                        struct blame_entry this[3];
1107
1108                        if (!DIFF_FILE_VALID(p->one))
1109                                continue; /* does not exist in parent */
1110                        if (porigin && !strcmp(p->one->path, porigin->path))
1111                                /* find_move already dealt with this path */
1112                                continue;
1113
1114                        norigin = get_origin(sb, parent, p->one->path);
1115                        hashcpy(norigin->blob_sha1, p->one->sha1);
1116                        fill_origin_blob(norigin, &file_p);
1117                        if (!file_p.ptr)
1118                                continue;
1119
1120                        for (j = 0; j < num_ents; j++) {
1121                                find_copy_in_blob(sb, blame_list[j].ent,
1122                                                  norigin, this, &file_p);
1123                                copy_split_if_better(sb, blame_list[j].split,
1124                                                     this);
1125                                decref_split(this);
1126                        }
1127                        origin_decref(norigin);
1128                }
1129
1130                for (j = 0; j < num_ents; j++) {
1131                        struct blame_entry *split = blame_list[j].split;
1132                        if (split[1].suspect &&
1133                            blame_copy_score < ent_score(sb, &split[1])) {
1134                                split_blame(sb, split, blame_list[j].ent);
1135                                made_progress = 1;
1136                        }
1137                        decref_split(split);
1138                }
1139                free(blame_list);
1140
1141                if (!made_progress)
1142                        break;
1143                blame_list = setup_blame_list(sb, target, &num_ents);
1144                if (!blame_list) {
1145                        retval = 1;
1146                        break;
1147                }
1148        }
1149        diff_flush(&diff_opts);
1150
1151        return retval;
1152}
1153
1154/*
1155 * The blobs of origin and porigin exactly match, so everything
1156 * origin is suspected for can be blamed on the parent.
1157 */
1158static void pass_whole_blame(struct scoreboard *sb,
1159                             struct origin *origin, struct origin *porigin)
1160{
1161        struct blame_entry *e;
1162
1163        if (!porigin->file.ptr && origin->file.ptr) {
1164                /* Steal its file */
1165                porigin->file = origin->file;
1166                origin->file.ptr = NULL;
1167        }
1168        for (e = sb->ent; e; e = e->next) {
1169                if (!same_suspect(e->suspect, origin))
1170                        continue;
1171                origin_incref(porigin);
1172                origin_decref(e->suspect);
1173                e->suspect = porigin;
1174        }
1175}
1176
1177#define MAXPARENT 16
1178
1179static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1180{
1181        int i, pass;
1182        struct commit *commit = origin->commit;
1183        struct commit_list *parent;
1184        struct origin *parent_origin[MAXPARENT], *porigin;
1185
1186        memset(parent_origin, 0, sizeof(parent_origin));
1187
1188        /* The first pass looks for unrenamed path to optimize for
1189         * common cases, then we look for renames in the second pass.
1190         */
1191        for (pass = 0; pass < 2; pass++) {
1192                struct origin *(*find)(struct scoreboard *,
1193                                       struct commit *, struct origin *);
1194                find = pass ? find_rename : find_origin;
1195
1196                for (i = 0, parent = commit->parents;
1197                     i < MAXPARENT && parent;
1198                     parent = parent->next, i++) {
1199                        struct commit *p = parent->item;
1200                        int j, same;
1201
1202                        if (parent_origin[i])
1203                                continue;
1204                        if (parse_commit(p))
1205                                continue;
1206                        porigin = find(sb, p, origin);
1207                        if (!porigin)
1208                                continue;
1209                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1210                                pass_whole_blame(sb, origin, porigin);
1211                                origin_decref(porigin);
1212                                goto finish;
1213                        }
1214                        for (j = same = 0; j < i; j++)
1215                                if (parent_origin[j] &&
1216                                    !hashcmp(parent_origin[j]->blob_sha1,
1217                                             porigin->blob_sha1)) {
1218                                        same = 1;
1219                                        break;
1220                                }
1221                        if (!same)
1222                                parent_origin[i] = porigin;
1223                        else
1224                                origin_decref(porigin);
1225                }
1226        }
1227
1228        num_commits++;
1229        for (i = 0, parent = commit->parents;
1230             i < MAXPARENT && parent;
1231             parent = parent->next, i++) {
1232                struct origin *porigin = parent_origin[i];
1233                if (!porigin)
1234                        continue;
1235                if (pass_blame_to_parent(sb, origin, porigin))
1236                        goto finish;
1237        }
1238
1239        /*
1240         * Optionally find moves in parents' files.
1241         */
1242        if (opt & PICKAXE_BLAME_MOVE)
1243                for (i = 0, parent = commit->parents;
1244                     i < MAXPARENT && parent;
1245                     parent = parent->next, i++) {
1246                        struct origin *porigin = parent_origin[i];
1247                        if (!porigin)
1248                                continue;
1249                        if (find_move_in_parent(sb, origin, porigin))
1250                                goto finish;
1251                }
1252
1253        /*
1254         * Optionally find copies from parents' files.
1255         */
1256        if (opt & PICKAXE_BLAME_COPY)
1257                for (i = 0, parent = commit->parents;
1258                     i < MAXPARENT && parent;
1259                     parent = parent->next, i++) {
1260                        struct origin *porigin = parent_origin[i];
1261                        if (find_copy_in_parent(sb, origin, parent->item,
1262                                                porigin, opt))
1263                                goto finish;
1264                }
1265
1266 finish:
1267        for (i = 0; i < MAXPARENT; i++)
1268                origin_decref(parent_origin[i]);
1269}
1270
1271/*
1272 * Information on commits, used for output.
1273 */
1274struct commit_info
1275{
1276        const char *author;
1277        const char *author_mail;
1278        unsigned long author_time;
1279        const char *author_tz;
1280
1281        /* filled only when asked for details */
1282        const char *committer;
1283        const char *committer_mail;
1284        unsigned long committer_time;
1285        const char *committer_tz;
1286
1287        const char *summary;
1288};
1289
1290/*
1291 * Parse author/committer line in the commit object buffer
1292 */
1293static void get_ac_line(const char *inbuf, const char *what,
1294                        int bufsz, char *person, const char **mail,
1295                        unsigned long *time, const char **tz)
1296{
1297        int len;
1298        char *tmp, *endp;
1299
1300        tmp = strstr(inbuf, what);
1301        if (!tmp)
1302                goto error_out;
1303        tmp += strlen(what);
1304        endp = strchr(tmp, '\n');
1305        if (!endp)
1306                len = strlen(tmp);
1307        else
1308                len = endp - tmp;
1309        if (bufsz <= len) {
1310        error_out:
1311                /* Ugh */
1312                *mail = *tz = "(unknown)";
1313                *time = 0;
1314                return;
1315        }
1316        memcpy(person, tmp, len);
1317
1318        tmp = person;
1319        tmp += len;
1320        *tmp = 0;
1321        while (*tmp != ' ')
1322                tmp--;
1323        *tz = tmp+1;
1324
1325        *tmp = 0;
1326        while (*tmp != ' ')
1327                tmp--;
1328        *time = strtoul(tmp, NULL, 10);
1329
1330        *tmp = 0;
1331        while (*tmp != ' ')
1332                tmp--;
1333        *mail = tmp + 1;
1334        *tmp = 0;
1335}
1336
1337static void get_commit_info(struct commit *commit,
1338                            struct commit_info *ret,
1339                            int detailed)
1340{
1341        int len;
1342        char *tmp, *endp;
1343        static char author_buf[1024];
1344        static char committer_buf[1024];
1345        static char summary_buf[1024];
1346
1347        /*
1348         * We've operated without save_commit_buffer, so
1349         * we now need to populate them for output.
1350         */
1351        if (!commit->buffer) {
1352                enum object_type type;
1353                unsigned long size;
1354                commit->buffer =
1355                        read_sha1_file(commit->object.sha1, &type, &size);
1356        }
1357        ret->author = author_buf;
1358        get_ac_line(commit->buffer, "\nauthor ",
1359                    sizeof(author_buf), author_buf, &ret->author_mail,
1360                    &ret->author_time, &ret->author_tz);
1361
1362        if (!detailed)
1363                return;
1364
1365        ret->committer = committer_buf;
1366        get_ac_line(commit->buffer, "\ncommitter ",
1367                    sizeof(committer_buf), committer_buf, &ret->committer_mail,
1368                    &ret->committer_time, &ret->committer_tz);
1369
1370        ret->summary = summary_buf;
1371        tmp = strstr(commit->buffer, "\n\n");
1372        if (!tmp) {
1373        error_out:
1374                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1375                return;
1376        }
1377        tmp += 2;
1378        endp = strchr(tmp, '\n');
1379        if (!endp)
1380                endp = tmp + strlen(tmp);
1381        len = endp - tmp;
1382        if (len >= sizeof(summary_buf) || len == 0)
1383                goto error_out;
1384        memcpy(summary_buf, tmp, len);
1385        summary_buf[len] = 0;
1386}
1387
1388/*
1389 * To allow LF and other nonportable characters in pathnames,
1390 * they are c-style quoted as needed.
1391 */
1392static void write_filename_info(const char *path)
1393{
1394        printf("filename ");
1395        write_name_quoted(NULL, 0, path, 1, stdout);
1396        putchar('\n');
1397}
1398
1399/*
1400 * The blame_entry is found to be guilty for the range.  Mark it
1401 * as such, and show it in incremental output.
1402 */
1403static void found_guilty_entry(struct blame_entry *ent)
1404{
1405        if (ent->guilty)
1406                return;
1407        ent->guilty = 1;
1408        if (incremental) {
1409                struct origin *suspect = ent->suspect;
1410
1411                printf("%s %d %d %d\n",
1412                       sha1_to_hex(suspect->commit->object.sha1),
1413                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1414                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1415                        struct commit_info ci;
1416                        suspect->commit->object.flags |= METAINFO_SHOWN;
1417                        get_commit_info(suspect->commit, &ci, 1);
1418                        printf("author %s\n", ci.author);
1419                        printf("author-mail %s\n", ci.author_mail);
1420                        printf("author-time %lu\n", ci.author_time);
1421                        printf("author-tz %s\n", ci.author_tz);
1422                        printf("committer %s\n", ci.committer);
1423                        printf("committer-mail %s\n", ci.committer_mail);
1424                        printf("committer-time %lu\n", ci.committer_time);
1425                        printf("committer-tz %s\n", ci.committer_tz);
1426                        printf("summary %s\n", ci.summary);
1427                        if (suspect->commit->object.flags & UNINTERESTING)
1428                                printf("boundary\n");
1429                }
1430                write_filename_info(suspect->path);
1431        }
1432}
1433
1434/*
1435 * The main loop -- while the scoreboard has lines whose true origin
1436 * is still unknown, pick one blame_entry, and allow its current
1437 * suspect to pass blames to its parents.
1438 */
1439static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1440{
1441        while (1) {
1442                struct blame_entry *ent;
1443                struct commit *commit;
1444                struct origin *suspect = NULL;
1445
1446                /* find one suspect to break down */
1447                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1448                        if (!ent->guilty)
1449                                suspect = ent->suspect;
1450                if (!suspect)
1451                        return; /* all done */
1452
1453                /*
1454                 * We will use this suspect later in the loop,
1455                 * so hold onto it in the meantime.
1456                 */
1457                origin_incref(suspect);
1458                commit = suspect->commit;
1459                if (!commit->object.parsed)
1460                        parse_commit(commit);
1461                if (!(commit->object.flags & UNINTERESTING) &&
1462                    !(revs->max_age != -1 && commit->date < revs->max_age))
1463                        pass_blame(sb, suspect, opt);
1464                else {
1465                        commit->object.flags |= UNINTERESTING;
1466                        if (commit->object.parsed)
1467                                mark_parents_uninteresting(commit);
1468                }
1469                /* treat root commit as boundary */
1470                if (!commit->parents && !show_root)
1471                        commit->object.flags |= UNINTERESTING;
1472
1473                /* Take responsibility for the remaining entries */
1474                for (ent = sb->ent; ent; ent = ent->next)
1475                        if (same_suspect(ent->suspect, suspect))
1476                                found_guilty_entry(ent);
1477                origin_decref(suspect);
1478
1479                if (DEBUG) /* sanity */
1480                        sanity_check_refcnt(sb);
1481        }
1482}
1483
1484static const char *format_time(unsigned long time, const char *tz_str,
1485                               int show_raw_time)
1486{
1487        static char time_buf[128];
1488        time_t t = time;
1489        int minutes, tz;
1490        struct tm *tm;
1491
1492        if (show_raw_time) {
1493                sprintf(time_buf, "%lu %s", time, tz_str);
1494                return time_buf;
1495        }
1496
1497        tz = atoi(tz_str);
1498        minutes = tz < 0 ? -tz : tz;
1499        minutes = (minutes / 100)*60 + (minutes % 100);
1500        minutes = tz < 0 ? -minutes : minutes;
1501        t = time + minutes * 60;
1502        tm = gmtime(&t);
1503
1504        strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1505        strcat(time_buf, tz_str);
1506        return time_buf;
1507}
1508
1509#define OUTPUT_ANNOTATE_COMPAT  001
1510#define OUTPUT_LONG_OBJECT_NAME 002
1511#define OUTPUT_RAW_TIMESTAMP    004
1512#define OUTPUT_PORCELAIN        010
1513#define OUTPUT_SHOW_NAME        020
1514#define OUTPUT_SHOW_NUMBER      040
1515#define OUTPUT_SHOW_SCORE      0100
1516
1517static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1518{
1519        int cnt;
1520        const char *cp;
1521        struct origin *suspect = ent->suspect;
1522        char hex[41];
1523
1524        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1525        printf("%s%c%d %d %d\n",
1526               hex,
1527               ent->guilty ? ' ' : '*', // purely for debugging
1528               ent->s_lno + 1,
1529               ent->lno + 1,
1530               ent->num_lines);
1531        if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1532                struct commit_info ci;
1533                suspect->commit->object.flags |= METAINFO_SHOWN;
1534                get_commit_info(suspect->commit, &ci, 1);
1535                printf("author %s\n", ci.author);
1536                printf("author-mail %s\n", ci.author_mail);
1537                printf("author-time %lu\n", ci.author_time);
1538                printf("author-tz %s\n", ci.author_tz);
1539                printf("committer %s\n", ci.committer);
1540                printf("committer-mail %s\n", ci.committer_mail);
1541                printf("committer-time %lu\n", ci.committer_time);
1542                printf("committer-tz %s\n", ci.committer_tz);
1543                write_filename_info(suspect->path);
1544                printf("summary %s\n", ci.summary);
1545                if (suspect->commit->object.flags & UNINTERESTING)
1546                        printf("boundary\n");
1547        }
1548        else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1549                write_filename_info(suspect->path);
1550
1551        cp = nth_line(sb, ent->lno);
1552        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1553                char ch;
1554                if (cnt)
1555                        printf("%s %d %d\n", hex,
1556                               ent->s_lno + 1 + cnt,
1557                               ent->lno + 1 + cnt);
1558                putchar('\t');
1559                do {
1560                        ch = *cp++;
1561                        putchar(ch);
1562                } while (ch != '\n' &&
1563                         cp < sb->final_buf + sb->final_buf_size);
1564        }
1565}
1566
1567static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1568{
1569        int cnt;
1570        const char *cp;
1571        struct origin *suspect = ent->suspect;
1572        struct commit_info ci;
1573        char hex[41];
1574        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1575
1576        get_commit_info(suspect->commit, &ci, 1);
1577        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1578
1579        cp = nth_line(sb, ent->lno);
1580        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1581                char ch;
1582                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1583
1584                if (suspect->commit->object.flags & UNINTERESTING) {
1585                        if (blank_boundary)
1586                                memset(hex, ' ', length);
1587                        else if (!cmd_is_annotate) {
1588                                length--;
1589                                putchar('^');
1590                        }
1591                }
1592
1593                printf("%.*s", length, hex);
1594                if (opt & OUTPUT_ANNOTATE_COMPAT)
1595                        printf("\t(%10s\t%10s\t%d)", ci.author,
1596                               format_time(ci.author_time, ci.author_tz,
1597                                           show_raw_time),
1598                               ent->lno + 1 + cnt);
1599                else {
1600                        if (opt & OUTPUT_SHOW_SCORE)
1601                                printf(" %*d %02d",
1602                                       max_score_digits, ent->score,
1603                                       ent->suspect->refcnt);
1604                        if (opt & OUTPUT_SHOW_NAME)
1605                                printf(" %-*.*s", longest_file, longest_file,
1606                                       suspect->path);
1607                        if (opt & OUTPUT_SHOW_NUMBER)
1608                                printf(" %*d", max_orig_digits,
1609                                       ent->s_lno + 1 + cnt);
1610                        printf(" (%-*.*s %10s %*d) ",
1611                               longest_author, longest_author, ci.author,
1612                               format_time(ci.author_time, ci.author_tz,
1613                                           show_raw_time),
1614                               max_digits, ent->lno + 1 + cnt);
1615                }
1616                do {
1617                        ch = *cp++;
1618                        putchar(ch);
1619                } while (ch != '\n' &&
1620                         cp < sb->final_buf + sb->final_buf_size);
1621        }
1622}
1623
1624static void output(struct scoreboard *sb, int option)
1625{
1626        struct blame_entry *ent;
1627
1628        if (option & OUTPUT_PORCELAIN) {
1629                for (ent = sb->ent; ent; ent = ent->next) {
1630                        struct blame_entry *oth;
1631                        struct origin *suspect = ent->suspect;
1632                        struct commit *commit = suspect->commit;
1633                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1634                                continue;
1635                        for (oth = ent->next; oth; oth = oth->next) {
1636                                if ((oth->suspect->commit != commit) ||
1637                                    !strcmp(oth->suspect->path, suspect->path))
1638                                        continue;
1639                                commit->object.flags |= MORE_THAN_ONE_PATH;
1640                                break;
1641                        }
1642                }
1643        }
1644
1645        for (ent = sb->ent; ent; ent = ent->next) {
1646                if (option & OUTPUT_PORCELAIN)
1647                        emit_porcelain(sb, ent);
1648                else {
1649                        emit_other(sb, ent, option);
1650                }
1651        }
1652}
1653
1654/*
1655 * To allow quick access to the contents of nth line in the
1656 * final image, prepare an index in the scoreboard.
1657 */
1658static int prepare_lines(struct scoreboard *sb)
1659{
1660        const char *buf = sb->final_buf;
1661        unsigned long len = sb->final_buf_size;
1662        int num = 0, incomplete = 0, bol = 1;
1663
1664        if (len && buf[len-1] != '\n')
1665                incomplete++; /* incomplete line at the end */
1666        while (len--) {
1667                if (bol) {
1668                        sb->lineno = xrealloc(sb->lineno,
1669                                              sizeof(int* ) * (num + 1));
1670                        sb->lineno[num] = buf - sb->final_buf;
1671                        bol = 0;
1672                }
1673                if (*buf++ == '\n') {
1674                        num++;
1675                        bol = 1;
1676                }
1677        }
1678        sb->lineno = xrealloc(sb->lineno,
1679                              sizeof(int* ) * (num + incomplete + 1));
1680        sb->lineno[num + incomplete] = buf - sb->final_buf;
1681        sb->num_lines = num + incomplete;
1682        return sb->num_lines;
1683}
1684
1685/*
1686 * Add phony grafts for use with -S; this is primarily to
1687 * support git-cvsserver that wants to give a linear history
1688 * to its clients.
1689 */
1690static int read_ancestry(const char *graft_file)
1691{
1692        FILE *fp = fopen(graft_file, "r");
1693        char buf[1024];
1694        if (!fp)
1695                return -1;
1696        while (fgets(buf, sizeof(buf), fp)) {
1697                /* The format is just "Commit Parent1 Parent2 ...\n" */
1698                int len = strlen(buf);
1699                struct commit_graft *graft = read_graft_line(buf, len);
1700                if (graft)
1701                        register_commit_graft(graft, 0);
1702        }
1703        fclose(fp);
1704        return 0;
1705}
1706
1707/*
1708 * How many columns do we need to show line numbers in decimal?
1709 */
1710static int lineno_width(int lines)
1711{
1712        int i, width;
1713
1714        for (width = 1, i = 10; i <= lines + 1; width++)
1715                i *= 10;
1716        return width;
1717}
1718
1719/*
1720 * How many columns do we need to show line numbers, authors,
1721 * and filenames?
1722 */
1723static void find_alignment(struct scoreboard *sb, int *option)
1724{
1725        int longest_src_lines = 0;
1726        int longest_dst_lines = 0;
1727        unsigned largest_score = 0;
1728        struct blame_entry *e;
1729
1730        for (e = sb->ent; e; e = e->next) {
1731                struct origin *suspect = e->suspect;
1732                struct commit_info ci;
1733                int num;
1734
1735                if (strcmp(suspect->path, sb->path))
1736                        *option |= OUTPUT_SHOW_NAME;
1737                num = strlen(suspect->path);
1738                if (longest_file < num)
1739                        longest_file = num;
1740                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1741                        suspect->commit->object.flags |= METAINFO_SHOWN;
1742                        get_commit_info(suspect->commit, &ci, 1);
1743                        num = strlen(ci.author);
1744                        if (longest_author < num)
1745                                longest_author = num;
1746                }
1747                num = e->s_lno + e->num_lines;
1748                if (longest_src_lines < num)
1749                        longest_src_lines = num;
1750                num = e->lno + e->num_lines;
1751                if (longest_dst_lines < num)
1752                        longest_dst_lines = num;
1753                if (largest_score < ent_score(sb, e))
1754                        largest_score = ent_score(sb, e);
1755        }
1756        max_orig_digits = lineno_width(longest_src_lines);
1757        max_digits = lineno_width(longest_dst_lines);
1758        max_score_digits = lineno_width(largest_score);
1759}
1760
1761/*
1762 * For debugging -- origin is refcounted, and this asserts that
1763 * we do not underflow.
1764 */
1765static void sanity_check_refcnt(struct scoreboard *sb)
1766{
1767        int baa = 0;
1768        struct blame_entry *ent;
1769
1770        for (ent = sb->ent; ent; ent = ent->next) {
1771                /* Nobody should have zero or negative refcnt */
1772                if (ent->suspect->refcnt <= 0) {
1773                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1774                                ent->suspect->path,
1775                                sha1_to_hex(ent->suspect->commit->object.sha1),
1776                                ent->suspect->refcnt);
1777                        baa = 1;
1778                }
1779        }
1780        for (ent = sb->ent; ent; ent = ent->next) {
1781                /* Mark the ones that haven't been checked */
1782                if (0 < ent->suspect->refcnt)
1783                        ent->suspect->refcnt = -ent->suspect->refcnt;
1784        }
1785        for (ent = sb->ent; ent; ent = ent->next) {
1786                /*
1787                 * ... then pick each and see if they have the the
1788                 * correct refcnt.
1789                 */
1790                int found;
1791                struct blame_entry *e;
1792                struct origin *suspect = ent->suspect;
1793
1794                if (0 < suspect->refcnt)
1795                        continue;
1796                suspect->refcnt = -suspect->refcnt; /* Unmark */
1797                for (found = 0, e = sb->ent; e; e = e->next) {
1798                        if (e->suspect != suspect)
1799                                continue;
1800                        found++;
1801                }
1802                if (suspect->refcnt != found) {
1803                        fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1804                                ent->suspect->path,
1805                                sha1_to_hex(ent->suspect->commit->object.sha1),
1806                                ent->suspect->refcnt, found);
1807                        baa = 2;
1808                }
1809        }
1810        if (baa) {
1811                int opt = 0160;
1812                find_alignment(sb, &opt);
1813                output(sb, opt);
1814                die("Baa %d!", baa);
1815        }
1816}
1817
1818/*
1819 * Used for the command line parsing; check if the path exists
1820 * in the working tree.
1821 */
1822static int has_path_in_work_tree(const char *path)
1823{
1824        struct stat st;
1825        return !lstat(path, &st);
1826}
1827
1828static unsigned parse_score(const char *arg)
1829{
1830        char *end;
1831        unsigned long score = strtoul(arg, &end, 10);
1832        if (*end)
1833                return 0;
1834        return score;
1835}
1836
1837static const char *add_prefix(const char *prefix, const char *path)
1838{
1839        if (!prefix || !prefix[0])
1840                return path;
1841        return prefix_path(prefix, strlen(prefix), path);
1842}
1843
1844/*
1845 * Parsing of (comma separated) one item in the -L option
1846 */
1847static const char *parse_loc(const char *spec,
1848                             struct scoreboard *sb, long lno,
1849                             long begin, long *ret)
1850{
1851        char *term;
1852        const char *line;
1853        long num;
1854        int reg_error;
1855        regex_t regexp;
1856        regmatch_t match[1];
1857
1858        /* Allow "-L <something>,+20" to mean starting at <something>
1859         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1860         * <something>.
1861         */
1862        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1863                num = strtol(spec + 1, &term, 10);
1864                if (term != spec + 1) {
1865                        if (spec[0] == '-')
1866                                num = 0 - num;
1867                        if (0 < num)
1868                                *ret = begin + num - 2;
1869                        else if (!num)
1870                                *ret = begin;
1871                        else
1872                                *ret = begin + num;
1873                        return term;
1874                }
1875                return spec;
1876        }
1877        num = strtol(spec, &term, 10);
1878        if (term != spec) {
1879                *ret = num;
1880                return term;
1881        }
1882        if (spec[0] != '/')
1883                return spec;
1884
1885        /* it could be a regexp of form /.../ */
1886        for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1887                if (*term == '\\')
1888                        term++;
1889        }
1890        if (*term != '/')
1891                return spec;
1892
1893        /* try [spec+1 .. term-1] as regexp */
1894        *term = 0;
1895        begin--; /* input is in human terms */
1896        line = nth_line(sb, begin);
1897
1898        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1899            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1900                const char *cp = line + match[0].rm_so;
1901                const char *nline;
1902
1903                while (begin++ < lno) {
1904                        nline = nth_line(sb, begin);
1905                        if (line <= cp && cp < nline)
1906                                break;
1907                        line = nline;
1908                }
1909                *ret = begin;
1910                regfree(&regexp);
1911                *term++ = '/';
1912                return term;
1913        }
1914        else {
1915                char errbuf[1024];
1916                regerror(reg_error, &regexp, errbuf, 1024);
1917                die("-L parameter '%s': %s", spec + 1, errbuf);
1918        }
1919}
1920
1921/*
1922 * Parsing of -L option
1923 */
1924static void prepare_blame_range(struct scoreboard *sb,
1925                                const char *bottomtop,
1926                                long lno,
1927                                long *bottom, long *top)
1928{
1929        const char *term;
1930
1931        term = parse_loc(bottomtop, sb, lno, 1, bottom);
1932        if (*term == ',') {
1933                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1934                if (*term)
1935                        usage(blame_usage);
1936        }
1937        if (*term)
1938                usage(blame_usage);
1939}
1940
1941static int git_blame_config(const char *var, const char *value)
1942{
1943        if (!strcmp(var, "blame.showroot")) {
1944                show_root = git_config_bool(var, value);
1945                return 0;
1946        }
1947        if (!strcmp(var, "blame.blankboundary")) {
1948                blank_boundary = git_config_bool(var, value);
1949                return 0;
1950        }
1951        return git_default_config(var, value);
1952}
1953
1954static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1955{
1956        struct commit *commit;
1957        struct origin *origin;
1958        unsigned char head_sha1[20];
1959        char *buf;
1960        const char *ident;
1961        int fd;
1962        time_t now;
1963        unsigned long fin_size;
1964        int size, len;
1965        struct cache_entry *ce;
1966        unsigned mode;
1967
1968        if (get_sha1("HEAD", head_sha1))
1969                die("No such ref: HEAD");
1970
1971        time(&now);
1972        commit = xcalloc(1, sizeof(*commit));
1973        commit->parents = xcalloc(1, sizeof(*commit->parents));
1974        commit->parents->item = lookup_commit_reference(head_sha1);
1975        commit->object.parsed = 1;
1976        commit->date = now;
1977        commit->object.type = OBJ_COMMIT;
1978
1979        origin = make_origin(commit, path);
1980
1981        if (!contents_from || strcmp("-", contents_from)) {
1982                struct stat st;
1983                const char *read_from;
1984
1985                if (contents_from) {
1986                        if (stat(contents_from, &st) < 0)
1987                                die("Cannot stat %s", contents_from);
1988                        read_from = contents_from;
1989                }
1990                else {
1991                        if (lstat(path, &st) < 0)
1992                                die("Cannot lstat %s", path);
1993                        read_from = path;
1994                }
1995                fin_size = xsize_t(st.st_size);
1996                buf = xmalloc(fin_size+1);
1997                mode = canon_mode(st.st_mode);
1998                switch (st.st_mode & S_IFMT) {
1999                case S_IFREG:
2000                        fd = open(read_from, O_RDONLY);
2001                        if (fd < 0)
2002                                die("cannot open %s", read_from);
2003                        if (read_in_full(fd, buf, fin_size) != fin_size)
2004                                die("cannot read %s", read_from);
2005                        break;
2006                case S_IFLNK:
2007                        if (readlink(read_from, buf, fin_size+1) != fin_size)
2008                                die("cannot readlink %s", read_from);
2009                        break;
2010                default:
2011                        die("unsupported file type %s", read_from);
2012                }
2013        }
2014        else {
2015                /* Reading from stdin */
2016                contents_from = "standard input";
2017                buf = NULL;
2018                fin_size = 0;
2019                mode = 0;
2020                while (1) {
2021                        ssize_t cnt = 8192;
2022                        buf = xrealloc(buf, fin_size + cnt);
2023                        cnt = xread(0, buf + fin_size, cnt);
2024                        if (cnt < 0)
2025                                die("read error %s from stdin",
2026                                    strerror(errno));
2027                        if (!cnt)
2028                                break;
2029                        fin_size += cnt;
2030                }
2031                buf = xrealloc(buf, fin_size + 1);
2032        }
2033        buf[fin_size] = 0;
2034        origin->file.ptr = buf;
2035        origin->file.size = fin_size;
2036        pretend_sha1_file(buf, fin_size, OBJ_BLOB, origin->blob_sha1);
2037        commit->util = origin;
2038
2039        /*
2040         * Read the current index, replace the path entry with
2041         * origin->blob_sha1 without mucking with its mode or type
2042         * bits; we are not going to write this index out -- we just
2043         * want to run "diff-index --cached".
2044         */
2045        discard_cache();
2046        read_cache();
2047
2048        len = strlen(path);
2049        if (!mode) {
2050                int pos = cache_name_pos(path, len);
2051                if (0 <= pos)
2052                        mode = ntohl(active_cache[pos]->ce_mode);
2053                else
2054                        /* Let's not bother reading from HEAD tree */
2055                        mode = S_IFREG | 0644;
2056        }
2057        size = cache_entry_size(len);
2058        ce = xcalloc(1, size);
2059        hashcpy(ce->sha1, origin->blob_sha1);
2060        memcpy(ce->name, path, len);
2061        ce->ce_flags = create_ce_flags(len, 0);
2062        ce->ce_mode = create_ce_mode(mode);
2063        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2064
2065        /*
2066         * We are not going to write this out, so this does not matter
2067         * right now, but someday we might optimize diff-index --cached
2068         * with cache-tree information.
2069         */
2070        cache_tree_invalidate_path(active_cache_tree, path);
2071
2072        commit->buffer = xmalloc(400);
2073        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2074        snprintf(commit->buffer, 400,
2075                "tree 0000000000000000000000000000000000000000\n"
2076                "parent %s\n"
2077                "author %s\n"
2078                "committer %s\n\n"
2079                "Version of %s from %s\n",
2080                sha1_to_hex(head_sha1),
2081                ident, ident, path, contents_from ? contents_from : path);
2082        return commit;
2083}
2084
2085int cmd_blame(int argc, const char **argv, const char *prefix)
2086{
2087        struct rev_info revs;
2088        const char *path;
2089        struct scoreboard sb;
2090        struct origin *o;
2091        struct blame_entry *ent;
2092        int i, seen_dashdash, unk, opt;
2093        long bottom, top, lno;
2094        int output_option = 0;
2095        int show_stats = 0;
2096        const char *revs_file = NULL;
2097        const char *final_commit_name = NULL;
2098        enum object_type type;
2099        const char *bottomtop = NULL;
2100        const char *contents_from = NULL;
2101
2102        cmd_is_annotate = !strcmp(argv[0], "annotate");
2103
2104        git_config(git_blame_config);
2105        save_commit_buffer = 0;
2106
2107        opt = 0;
2108        seen_dashdash = 0;
2109        for (unk = i = 1; i < argc; i++) {
2110                const char *arg = argv[i];
2111                if (*arg != '-')
2112                        break;
2113                else if (!strcmp("-b", arg))
2114                        blank_boundary = 1;
2115                else if (!strcmp("--root", arg))
2116                        show_root = 1;
2117                else if (!strcmp(arg, "--show-stats"))
2118                        show_stats = 1;
2119                else if (!strcmp("-c", arg))
2120                        output_option |= OUTPUT_ANNOTATE_COMPAT;
2121                else if (!strcmp("-t", arg))
2122                        output_option |= OUTPUT_RAW_TIMESTAMP;
2123                else if (!strcmp("-l", arg))
2124                        output_option |= OUTPUT_LONG_OBJECT_NAME;
2125                else if (!strcmp("-S", arg) && ++i < argc)
2126                        revs_file = argv[i];
2127                else if (!prefixcmp(arg, "-M")) {
2128                        opt |= PICKAXE_BLAME_MOVE;
2129                        blame_move_score = parse_score(arg+2);
2130                }
2131                else if (!prefixcmp(arg, "-C")) {
2132                        /*
2133                         * -C enables copy from removed files;
2134                         * -C -C enables copy from existing files, but only
2135                         *       when blaming a new file;
2136                         * -C -C -C enables copy from existing files for
2137                         *          everybody
2138                         */
2139                        if (opt & PICKAXE_BLAME_COPY_HARDER)
2140                                opt |= PICKAXE_BLAME_COPY_HARDEST;
2141                        if (opt & PICKAXE_BLAME_COPY)
2142                                opt |= PICKAXE_BLAME_COPY_HARDER;
2143                        opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2144                        blame_copy_score = parse_score(arg+2);
2145                }
2146                else if (!prefixcmp(arg, "-L")) {
2147                        if (!arg[2]) {
2148                                if (++i >= argc)
2149                                        usage(blame_usage);
2150                                arg = argv[i];
2151                        }
2152                        else
2153                                arg += 2;
2154                        if (bottomtop)
2155                                die("More than one '-L n,m' option given");
2156                        bottomtop = arg;
2157                }
2158                else if (!strcmp("--contents", arg)) {
2159                        if (++i >= argc)
2160                                usage(blame_usage);
2161                        contents_from = argv[i];
2162                }
2163                else if (!strcmp("--incremental", arg))
2164                        incremental = 1;
2165                else if (!strcmp("--score-debug", arg))
2166                        output_option |= OUTPUT_SHOW_SCORE;
2167                else if (!strcmp("-f", arg) ||
2168                         !strcmp("--show-name", arg))
2169                        output_option |= OUTPUT_SHOW_NAME;
2170                else if (!strcmp("-n", arg) ||
2171                         !strcmp("--show-number", arg))
2172                        output_option |= OUTPUT_SHOW_NUMBER;
2173                else if (!strcmp("-p", arg) ||
2174                         !strcmp("--porcelain", arg))
2175                        output_option |= OUTPUT_PORCELAIN;
2176                else if (!strcmp("--", arg)) {
2177                        seen_dashdash = 1;
2178                        i++;
2179                        break;
2180                }
2181                else
2182                        argv[unk++] = arg;
2183        }
2184
2185        if (!incremental)
2186                setup_pager();
2187
2188        if (!blame_move_score)
2189                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2190        if (!blame_copy_score)
2191                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2192
2193        /*
2194         * We have collected options unknown to us in argv[1..unk]
2195         * which are to be passed to revision machinery if we are
2196         * going to do the "bottom" processing.
2197         *
2198         * The remaining are:
2199         *
2200         * (1) if seen_dashdash, its either
2201         *     "-options -- <path>" or
2202         *     "-options -- <path> <rev>".
2203         *     but the latter is allowed only if there is no
2204         *     options that we passed to revision machinery.
2205         *
2206         * (2) otherwise, we may have "--" somewhere later and
2207         *     might be looking at the first one of multiple 'rev'
2208         *     parameters (e.g. " master ^next ^maint -- path").
2209         *     See if there is a dashdash first, and give the
2210         *     arguments before that to revision machinery.
2211         *     After that there must be one 'path'.
2212         *
2213         * (3) otherwise, its one of the three:
2214         *     "-options <path> <rev>"
2215         *     "-options <rev> <path>"
2216         *     "-options <path>"
2217         *     but again the first one is allowed only if
2218         *     there is no options that we passed to revision
2219         *     machinery.
2220         */
2221
2222        if (seen_dashdash) {
2223                /* (1) */
2224                if (argc <= i)
2225                        usage(blame_usage);
2226                path = add_prefix(prefix, argv[i]);
2227                if (i + 1 == argc - 1) {
2228                        if (unk != 1)
2229                                usage(blame_usage);
2230                        argv[unk++] = argv[i + 1];
2231                }
2232                else if (i + 1 != argc)
2233                        /* garbage at end */
2234                        usage(blame_usage);
2235        }
2236        else {
2237                int j;
2238                for (j = i; !seen_dashdash && j < argc; j++)
2239                        if (!strcmp(argv[j], "--"))
2240                                seen_dashdash = j;
2241                if (seen_dashdash) {
2242                        /* (2) */
2243                        if (seen_dashdash + 1 != argc - 1)
2244                                usage(blame_usage);
2245                        path = add_prefix(prefix, argv[seen_dashdash + 1]);
2246                        for (j = i; j < seen_dashdash; j++)
2247                                argv[unk++] = argv[j];
2248                }
2249                else {
2250                        /* (3) */
2251                        if (argc <= i)
2252                                usage(blame_usage);
2253                        path = add_prefix(prefix, argv[i]);
2254                        if (i + 1 == argc - 1) {
2255                                final_commit_name = argv[i + 1];
2256
2257                                /* if (unk == 1) we could be getting
2258                                 * old-style
2259                                 */
2260                                if (unk == 1 && !has_path_in_work_tree(path)) {
2261                                        path = add_prefix(prefix, argv[i + 1]);
2262                                        final_commit_name = argv[i];
2263                                }
2264                        }
2265                        else if (i != argc - 1)
2266                                usage(blame_usage); /* garbage at end */
2267
2268                        if (!has_path_in_work_tree(path))
2269                                die("cannot stat path %s: %s",
2270                                    path, strerror(errno));
2271                }
2272        }
2273
2274        if (final_commit_name)
2275                argv[unk++] = final_commit_name;
2276
2277        /*
2278         * Now we got rev and path.  We do not want the path pruning
2279         * but we may want "bottom" processing.
2280         */
2281        argv[unk++] = "--"; /* terminate the rev name */
2282        argv[unk] = NULL;
2283
2284        init_revisions(&revs, NULL);
2285        setup_revisions(unk, argv, &revs, NULL);
2286        memset(&sb, 0, sizeof(sb));
2287
2288        /*
2289         * There must be one and only one positive commit in the
2290         * revs->pending array.
2291         */
2292        for (i = 0; i < revs.pending.nr; i++) {
2293                struct object *obj = revs.pending.objects[i].item;
2294                if (obj->flags & UNINTERESTING)
2295                        continue;
2296                while (obj->type == OBJ_TAG)
2297                        obj = deref_tag(obj, NULL, 0);
2298                if (obj->type != OBJ_COMMIT)
2299                        die("Non commit %s?",
2300                            revs.pending.objects[i].name);
2301                if (sb.final)
2302                        die("More than one commit to dig from %s and %s?",
2303                            revs.pending.objects[i].name,
2304                            final_commit_name);
2305                sb.final = (struct commit *) obj;
2306                final_commit_name = revs.pending.objects[i].name;
2307        }
2308
2309        if (!sb.final) {
2310                /*
2311                 * "--not A B -- path" without anything positive;
2312                 * do not default to HEAD, but use the working tree
2313                 * or "--contents".
2314                 */
2315                sb.final = fake_working_tree_commit(path, contents_from);
2316                add_pending_object(&revs, &(sb.final->object), ":");
2317        }
2318        else if (contents_from)
2319                die("Cannot use --contents with final commit object name");
2320
2321        /*
2322         * If we have bottom, this will mark the ancestors of the
2323         * bottom commits we would reach while traversing as
2324         * uninteresting.
2325         */
2326        prepare_revision_walk(&revs);
2327
2328        if (is_null_sha1(sb.final->object.sha1)) {
2329                char *buf;
2330                o = sb.final->util;
2331                buf = xmalloc(o->file.size + 1);
2332                memcpy(buf, o->file.ptr, o->file.size + 1);
2333                sb.final_buf = buf;
2334                sb.final_buf_size = o->file.size;
2335        }
2336        else {
2337                o = get_origin(&sb, sb.final, path);
2338                if (fill_blob_sha1(o))
2339                        die("no such path %s in %s", path, final_commit_name);
2340
2341                sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2342                                              &sb.final_buf_size);
2343        }
2344        num_read_blob++;
2345        lno = prepare_lines(&sb);
2346
2347        bottom = top = 0;
2348        if (bottomtop)
2349                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2350        if (bottom && top && top < bottom) {
2351                long tmp;
2352                tmp = top; top = bottom; bottom = tmp;
2353        }
2354        if (bottom < 1)
2355                bottom = 1;
2356        if (top < 1)
2357                top = lno;
2358        bottom--;
2359        if (lno < top)
2360                die("file %s has only %lu lines", path, lno);
2361
2362        ent = xcalloc(1, sizeof(*ent));
2363        ent->lno = bottom;
2364        ent->num_lines = top - bottom;
2365        ent->suspect = o;
2366        ent->s_lno = bottom;
2367
2368        sb.ent = ent;
2369        sb.path = path;
2370
2371        if (revs_file && read_ancestry(revs_file))
2372                die("reading graft file %s failed: %s",
2373                    revs_file, strerror(errno));
2374
2375        assign_blame(&sb, &revs, opt);
2376
2377        if (incremental)
2378                return 0;
2379
2380        coalesce(&sb);
2381
2382        if (!(output_option & OUTPUT_PORCELAIN))
2383                find_alignment(&sb, &output_option);
2384
2385        output(&sb, output_option);
2386        free((void *)sb.final_buf);
2387        for (ent = sb.ent; ent; ) {
2388                struct blame_entry *e = ent->next;
2389                free(ent);
2390                ent = e;
2391        }
2392
2393        if (show_stats) {
2394                printf("num read blob: %d\n", num_read_blob);
2395                printf("num get patch: %d\n", num_get_patch);
2396                printf("num commits: %d\n", num_commits);
2397        }
2398        return 0;
2399}