line-log.con commit Merge branch 'nd/split-index-null-base-fix' (0efa3d7)
   1#include "git-compat-util.h"
   2#include "line-range.h"
   3#include "cache.h"
   4#include "tag.h"
   5#include "blob.h"
   6#include "tree.h"
   7#include "diff.h"
   8#include "commit.h"
   9#include "decorate.h"
  10#include "revision.h"
  11#include "xdiff-interface.h"
  12#include "strbuf.h"
  13#include "log-tree.h"
  14#include "graph.h"
  15#include "userdiff.h"
  16#include "line-log.h"
  17#include "argv-array.h"
  18
  19static void range_set_grow(struct range_set *rs, size_t extra)
  20{
  21        ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
  22}
  23
  24/* Either initialization would be fine */
  25#define RANGE_SET_INIT {0}
  26
  27void range_set_init(struct range_set *rs, size_t prealloc)
  28{
  29        rs->alloc = rs->nr = 0;
  30        rs->ranges = NULL;
  31        if (prealloc)
  32                range_set_grow(rs, prealloc);
  33}
  34
  35void range_set_release(struct range_set *rs)
  36{
  37        FREE_AND_NULL(rs->ranges);
  38        rs->alloc = rs->nr = 0;
  39}
  40
  41/* dst must be uninitialized! */
  42static void range_set_copy(struct range_set *dst, struct range_set *src)
  43{
  44        range_set_init(dst, src->nr);
  45        COPY_ARRAY(dst->ranges, src->ranges, src->nr);
  46        dst->nr = src->nr;
  47}
  48
  49static void range_set_move(struct range_set *dst, struct range_set *src)
  50{
  51        range_set_release(dst);
  52        dst->ranges = src->ranges;
  53        dst->nr = src->nr;
  54        dst->alloc = src->alloc;
  55        src->ranges = NULL;
  56        src->alloc = src->nr = 0;
  57}
  58
  59/* tack on a _new_ range _at the end_ */
  60void range_set_append_unsafe(struct range_set *rs, long a, long b)
  61{
  62        assert(a <= b);
  63        range_set_grow(rs, 1);
  64        rs->ranges[rs->nr].start = a;
  65        rs->ranges[rs->nr].end = b;
  66        rs->nr++;
  67}
  68
  69void range_set_append(struct range_set *rs, long a, long b)
  70{
  71        assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
  72        range_set_append_unsafe(rs, a, b);
  73}
  74
  75static int range_cmp(const void *_r, const void *_s)
  76{
  77        const struct range *r = _r;
  78        const struct range *s = _s;
  79
  80        /* this could be simply 'return r.start-s.start', but for the types */
  81        if (r->start == s->start)
  82                return 0;
  83        if (r->start < s->start)
  84                return -1;
  85        return 1;
  86}
  87
  88/*
  89 * Check that the ranges are non-empty, sorted and non-overlapping
  90 */
  91static void range_set_check_invariants(struct range_set *rs)
  92{
  93        unsigned int i;
  94
  95        if (!rs)
  96                return;
  97
  98        if (rs->nr)
  99                assert(rs->ranges[0].start < rs->ranges[0].end);
 100
 101        for (i = 1; i < rs->nr; i++) {
 102                assert(rs->ranges[i-1].end < rs->ranges[i].start);
 103                assert(rs->ranges[i].start < rs->ranges[i].end);
 104        }
 105}
 106
 107/*
 108 * In-place pass of sorting and merging the ranges in the range set,
 109 * to establish the invariants when we get the ranges from the user
 110 */
 111void sort_and_merge_range_set(struct range_set *rs)
 112{
 113        unsigned int i;
 114        unsigned int o = 0; /* output cursor */
 115
 116        QSORT(rs->ranges, rs->nr, range_cmp);
 117
 118        for (i = 0; i < rs->nr; i++) {
 119                if (rs->ranges[i].start == rs->ranges[i].end)
 120                        continue;
 121                if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
 122                        if (rs->ranges[o-1].end < rs->ranges[i].end)
 123                                rs->ranges[o-1].end = rs->ranges[i].end;
 124                } else {
 125                        rs->ranges[o].start = rs->ranges[i].start;
 126                        rs->ranges[o].end = rs->ranges[i].end;
 127                        o++;
 128                }
 129        }
 130        assert(o <= rs->nr);
 131        rs->nr = o;
 132
 133        range_set_check_invariants(rs);
 134}
 135
 136/*
 137 * Union of range sets (i.e., sets of line numbers).  Used to merge
 138 * them when searches meet at a common ancestor.
 139 *
 140 * This is also where the ranges are consolidated into canonical form:
 141 * overlapping and adjacent ranges are merged, and empty ranges are
 142 * removed.
 143 */
 144static void range_set_union(struct range_set *out,
 145                             struct range_set *a, struct range_set *b)
 146{
 147        unsigned int i = 0, j = 0;
 148        struct range *ra = a->ranges;
 149        struct range *rb = b->ranges;
 150        /* cannot make an alias of out->ranges: it may change during grow */
 151
 152        assert(out->nr == 0);
 153        while (i < a->nr || j < b->nr) {
 154                struct range *new_range;
 155                if (i < a->nr && j < b->nr) {
 156                        if (ra[i].start < rb[j].start)
 157                                new_range = &ra[i++];
 158                        else if (ra[i].start > rb[j].start)
 159                                new_range = &rb[j++];
 160                        else if (ra[i].end < rb[j].end)
 161                                new_range = &ra[i++];
 162                        else
 163                                new_range = &rb[j++];
 164                } else if (i < a->nr)      /* b exhausted */
 165                        new_range = &ra[i++];
 166                else                       /* a exhausted */
 167                        new_range = &rb[j++];
 168                if (new_range->start == new_range->end)
 169                        ; /* empty range */
 170                else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
 171                        range_set_grow(out, 1);
 172                        out->ranges[out->nr].start = new_range->start;
 173                        out->ranges[out->nr].end = new_range->end;
 174                        out->nr++;
 175                } else if (out->ranges[out->nr-1].end < new_range->end) {
 176                        out->ranges[out->nr-1].end = new_range->end;
 177                }
 178        }
 179}
 180
 181/*
 182 * Difference of range sets (out = a \ b).  Pass the "interesting"
 183 * ranges as 'a' and the target side of the diff as 'b': it removes
 184 * the ranges for which the commit is responsible.
 185 */
 186static void range_set_difference(struct range_set *out,
 187                                  struct range_set *a, struct range_set *b)
 188{
 189        unsigned int i, j =  0;
 190        for (i = 0; i < a->nr; i++) {
 191                long start = a->ranges[i].start;
 192                long end = a->ranges[i].end;
 193                while (start < end) {
 194                        while (j < b->nr && start >= b->ranges[j].end)
 195                                /*
 196                                 * a:         |-------
 197                                 * b: ------|
 198                                 */
 199                                j++;
 200                        if (j >= b->nr || end < b->ranges[j].start) {
 201                                /*
 202                                 * b exhausted, or
 203                                 * a:  ----|
 204                                 * b:         |----
 205                                 */
 206                                range_set_append(out, start, end);
 207                                break;
 208                        }
 209                        if (start >= b->ranges[j].start) {
 210                                /*
 211                                 * a:     |--????
 212                                 * b: |------|
 213                                 */
 214                                start = b->ranges[j].end;
 215                        } else if (end > b->ranges[j].start) {
 216                                /*
 217                                 * a: |-----|
 218                                 * b:    |--?????
 219                                 */
 220                                if (start < b->ranges[j].start)
 221                                        range_set_append(out, start, b->ranges[j].start);
 222                                start = b->ranges[j].end;
 223                        }
 224                }
 225        }
 226}
 227
 228static void diff_ranges_init(struct diff_ranges *diff)
 229{
 230        range_set_init(&diff->parent, 0);
 231        range_set_init(&diff->target, 0);
 232}
 233
 234static void diff_ranges_release(struct diff_ranges *diff)
 235{
 236        range_set_release(&diff->parent);
 237        range_set_release(&diff->target);
 238}
 239
 240static void line_log_data_init(struct line_log_data *r)
 241{
 242        memset(r, 0, sizeof(struct line_log_data));
 243        range_set_init(&r->ranges, 0);
 244}
 245
 246static void line_log_data_clear(struct line_log_data *r)
 247{
 248        range_set_release(&r->ranges);
 249        if (r->pair)
 250                diff_free_filepair(r->pair);
 251}
 252
 253static void free_line_log_data(struct line_log_data *r)
 254{
 255        while (r) {
 256                struct line_log_data *next = r->next;
 257                line_log_data_clear(r);
 258                free(r);
 259                r = next;
 260        }
 261}
 262
 263static struct line_log_data *
 264search_line_log_data(struct line_log_data *list, const char *path,
 265                     struct line_log_data **insertion_point)
 266{
 267        struct line_log_data *p = list;
 268        if (insertion_point)
 269                *insertion_point = NULL;
 270        while (p) {
 271                int cmp = strcmp(p->path, path);
 272                if (!cmp)
 273                        return p;
 274                if (insertion_point && cmp < 0)
 275                        *insertion_point = p;
 276                p = p->next;
 277        }
 278        return NULL;
 279}
 280
 281/*
 282 * Note: takes ownership of 'path', which happens to be what the only
 283 * caller needs.
 284 */
 285static void line_log_data_insert(struct line_log_data **list,
 286                                 char *path,
 287                                 long begin, long end)
 288{
 289        struct line_log_data *ip;
 290        struct line_log_data *p = search_line_log_data(*list, path, &ip);
 291
 292        if (p) {
 293                range_set_append_unsafe(&p->ranges, begin, end);
 294                free(path);
 295                return;
 296        }
 297
 298        p = xcalloc(1, sizeof(struct line_log_data));
 299        p->path = path;
 300        range_set_append(&p->ranges, begin, end);
 301        if (ip) {
 302                p->next = ip->next;
 303                ip->next = p;
 304        } else {
 305                p->next = *list;
 306                *list = p;
 307        }
 308}
 309
 310struct collect_diff_cbdata {
 311        struct diff_ranges *diff;
 312};
 313
 314static int collect_diff_cb(long start_a, long count_a,
 315                           long start_b, long count_b,
 316                           void *data)
 317{
 318        struct collect_diff_cbdata *d = data;
 319
 320        if (count_a >= 0)
 321                range_set_append(&d->diff->parent, start_a, start_a + count_a);
 322        if (count_b >= 0)
 323                range_set_append(&d->diff->target, start_b, start_b + count_b);
 324
 325        return 0;
 326}
 327
 328static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
 329{
 330        struct collect_diff_cbdata cbdata = {NULL};
 331        xpparam_t xpp;
 332        xdemitconf_t xecfg;
 333        xdemitcb_t ecb;
 334
 335        memset(&xpp, 0, sizeof(xpp));
 336        memset(&xecfg, 0, sizeof(xecfg));
 337        xecfg.ctxlen = xecfg.interhunkctxlen = 0;
 338
 339        cbdata.diff = out;
 340        xecfg.hunk_func = collect_diff_cb;
 341        memset(&ecb, 0, sizeof(ecb));
 342        ecb.priv = &cbdata;
 343        return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
 344}
 345
 346/*
 347 * These are handy for debugging.  Removing them with #if 0 silences
 348 * the "unused function" warning.
 349 */
 350#if 0
 351static void dump_range_set(struct range_set *rs, const char *desc)
 352{
 353        int i;
 354        printf("range set %s (%d items):\n", desc, rs->nr);
 355        for (i = 0; i < rs->nr; i++)
 356                printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
 357}
 358
 359static void dump_line_log_data(struct line_log_data *r)
 360{
 361        char buf[4096];
 362        while (r) {
 363                snprintf(buf, 4096, "file %s\n", r->path);
 364                dump_range_set(&r->ranges, buf);
 365                r = r->next;
 366        }
 367}
 368
 369static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
 370{
 371        int i;
 372        assert(diff->parent.nr == diff->target.nr);
 373        printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
 374        printf("\tparent\ttarget\n");
 375        for (i = 0; i < diff->parent.nr; i++) {
 376                printf("\t[%ld,%ld]\t[%ld,%ld]\n",
 377                       diff->parent.ranges[i].start,
 378                       diff->parent.ranges[i].end,
 379                       diff->target.ranges[i].start,
 380                       diff->target.ranges[i].end);
 381        }
 382}
 383#endif
 384
 385
 386static int ranges_overlap(struct range *a, struct range *b)
 387{
 388        return !(a->end <= b->start || b->end <= a->start);
 389}
 390
 391/*
 392 * Given a diff and the set of interesting ranges, determine all hunks
 393 * of the diff which touch (overlap) at least one of the interesting
 394 * ranges in the target.
 395 */
 396static void diff_ranges_filter_touched(struct diff_ranges *out,
 397                                       struct diff_ranges *diff,
 398                                       struct range_set *rs)
 399{
 400        unsigned int i, j = 0;
 401
 402        assert(out->target.nr == 0);
 403
 404        for (i = 0; i < diff->target.nr; i++) {
 405                while (diff->target.ranges[i].start > rs->ranges[j].end) {
 406                        j++;
 407                        if (j == rs->nr)
 408                                return;
 409                }
 410                if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
 411                        range_set_append(&out->parent,
 412                                         diff->parent.ranges[i].start,
 413                                         diff->parent.ranges[i].end);
 414                        range_set_append(&out->target,
 415                                         diff->target.ranges[i].start,
 416                                         diff->target.ranges[i].end);
 417                }
 418        }
 419}
 420
 421/*
 422 * Adjust the line counts in 'rs' to account for the lines
 423 * added/removed in the diff.
 424 */
 425static void range_set_shift_diff(struct range_set *out,
 426                                 struct range_set *rs,
 427                                 struct diff_ranges *diff)
 428{
 429        unsigned int i, j = 0;
 430        long offset = 0;
 431        struct range *src = rs->ranges;
 432        struct range *target = diff->target.ranges;
 433        struct range *parent = diff->parent.ranges;
 434
 435        for (i = 0; i < rs->nr; i++) {
 436                while (j < diff->target.nr && src[i].start >= target[j].start) {
 437                        offset += (parent[j].end-parent[j].start)
 438                                - (target[j].end-target[j].start);
 439                        j++;
 440                }
 441                range_set_append(out, src[i].start+offset, src[i].end+offset);
 442        }
 443}
 444
 445/*
 446 * Given a diff and the set of interesting ranges, map the ranges
 447 * across the diff.  That is: observe that the target commit takes
 448 * blame for all the + (target-side) ranges.  So for every pair of
 449 * ranges in the diff that was touched, we remove the latter and add
 450 * its parent side.
 451 */
 452static void range_set_map_across_diff(struct range_set *out,
 453                                      struct range_set *rs,
 454                                      struct diff_ranges *diff,
 455                                      struct diff_ranges **touched_out)
 456{
 457        struct diff_ranges *touched = xmalloc(sizeof(*touched));
 458        struct range_set tmp1 = RANGE_SET_INIT;
 459        struct range_set tmp2 = RANGE_SET_INIT;
 460
 461        diff_ranges_init(touched);
 462        diff_ranges_filter_touched(touched, diff, rs);
 463        range_set_difference(&tmp1, rs, &touched->target);
 464        range_set_shift_diff(&tmp2, &tmp1, diff);
 465        range_set_union(out, &tmp2, &touched->parent);
 466        range_set_release(&tmp1);
 467        range_set_release(&tmp2);
 468
 469        *touched_out = touched;
 470}
 471
 472static struct commit *check_single_commit(struct rev_info *revs)
 473{
 474        struct object *commit = NULL;
 475        int found = -1;
 476        int i;
 477
 478        for (i = 0; i < revs->pending.nr; i++) {
 479                struct object *obj = revs->pending.objects[i].item;
 480                if (obj->flags & UNINTERESTING)
 481                        continue;
 482                obj = deref_tag(revs->repo, obj, NULL, 0);
 483                if (obj->type != OBJ_COMMIT)
 484                        die("Non commit %s?", revs->pending.objects[i].name);
 485                if (commit)
 486                        die("More than one commit to dig from: %s and %s?",
 487                            revs->pending.objects[i].name,
 488                            revs->pending.objects[found].name);
 489                commit = obj;
 490                found = i;
 491        }
 492
 493        if (!commit)
 494                die("No commit specified?");
 495
 496        return (struct commit *) commit;
 497}
 498
 499static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
 500{
 501        unsigned mode;
 502        struct object_id oid;
 503
 504        if (get_tree_entry(&commit->object.oid, spec->path, &oid, &mode))
 505                die("There is no path %s in the commit", spec->path);
 506        fill_filespec(spec, &oid, 1, mode);
 507
 508        return;
 509}
 510
 511static void fill_line_ends(struct repository *r,
 512                           struct diff_filespec *spec,
 513                           long *lines,
 514                           unsigned long **line_ends)
 515{
 516        int num = 0, size = 50;
 517        long cur = 0;
 518        unsigned long *ends = NULL;
 519        char *data = NULL;
 520
 521        if (diff_populate_filespec(r, spec, 0))
 522                die("Cannot read blob %s", oid_to_hex(&spec->oid));
 523
 524        ALLOC_ARRAY(ends, size);
 525        ends[cur++] = 0;
 526        data = spec->data;
 527        while (num < spec->size) {
 528                if (data[num] == '\n' || num == spec->size - 1) {
 529                        ALLOC_GROW(ends, (cur + 1), size);
 530                        ends[cur++] = num;
 531                }
 532                num++;
 533        }
 534
 535        /* shrink the array to fit the elements */
 536        REALLOC_ARRAY(ends, cur);
 537        *lines = cur-1;
 538        *line_ends = ends;
 539}
 540
 541struct nth_line_cb {
 542        struct diff_filespec *spec;
 543        long lines;
 544        unsigned long *line_ends;
 545};
 546
 547static const char *nth_line(void *data, long line)
 548{
 549        struct nth_line_cb *d = data;
 550        assert(d && line <= d->lines);
 551        assert(d->spec && d->spec->data);
 552
 553        if (line == 0)
 554                return (char *)d->spec->data;
 555        else
 556                return (char *)d->spec->data + d->line_ends[line] + 1;
 557}
 558
 559static struct line_log_data *
 560parse_lines(struct repository *r, struct commit *commit,
 561            const char *prefix, struct string_list *args)
 562{
 563        long lines = 0;
 564        unsigned long *ends = NULL;
 565        struct nth_line_cb cb_data;
 566        struct string_list_item *item;
 567        struct line_log_data *ranges = NULL;
 568        struct line_log_data *p;
 569
 570        for_each_string_list_item(item, args) {
 571                const char *name_part, *range_part;
 572                char *full_name;
 573                struct diff_filespec *spec;
 574                long begin = 0, end = 0;
 575                long anchor;
 576
 577                name_part = skip_range_arg(item->string, r->index);
 578                if (!name_part || *name_part != ':' || !name_part[1])
 579                        die("-L argument not 'start,end:file' or ':funcname:file': %s",
 580                            item->string);
 581                range_part = xstrndup(item->string, name_part - item->string);
 582                name_part++;
 583
 584                full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 585                                        name_part);
 586
 587                spec = alloc_filespec(full_name);
 588                fill_blob_sha1(commit, spec);
 589                fill_line_ends(r, spec, &lines, &ends);
 590                cb_data.spec = spec;
 591                cb_data.lines = lines;
 592                cb_data.line_ends = ends;
 593
 594                p = search_line_log_data(ranges, full_name, NULL);
 595                if (p && p->ranges.nr)
 596                        anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 597                else
 598                        anchor = 1;
 599
 600                if (parse_range_arg(range_part, nth_line, &cb_data,
 601                                    lines, anchor, &begin, &end,
 602                                    full_name, r->index))
 603                        die("malformed -L argument '%s'", range_part);
 604                if ((!lines && (begin || end)) || lines < begin)
 605                        die("file %s has only %lu lines", name_part, lines);
 606                if (begin < 1)
 607                        begin = 1;
 608                if (end < 1 || lines < end)
 609                        end = lines;
 610                begin--;
 611                line_log_data_insert(&ranges, full_name, begin, end);
 612
 613                free_filespec(spec);
 614                FREE_AND_NULL(ends);
 615        }
 616
 617        for (p = ranges; p; p = p->next)
 618                sort_and_merge_range_set(&p->ranges);
 619
 620        return ranges;
 621}
 622
 623static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 624{
 625        struct line_log_data *ret = xmalloc(sizeof(*ret));
 626
 627        assert(r);
 628        line_log_data_init(ret);
 629        range_set_copy(&ret->ranges, &r->ranges);
 630
 631        ret->path = xstrdup(r->path);
 632
 633        return ret;
 634}
 635
 636static struct line_log_data *
 637line_log_data_copy(struct line_log_data *r)
 638{
 639        struct line_log_data *ret = NULL;
 640        struct line_log_data *tmp = NULL, *prev = NULL;
 641
 642        assert(r);
 643        ret = tmp = prev = line_log_data_copy_one(r);
 644        r = r->next;
 645        while (r) {
 646                tmp = line_log_data_copy_one(r);
 647                prev->next = tmp;
 648                prev = tmp;
 649                r = r->next;
 650        }
 651
 652        return ret;
 653}
 654
 655/* merge two range sets across files */
 656static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 657                                                 struct line_log_data *b)
 658{
 659        struct line_log_data *head = NULL, **pp = &head;
 660
 661        while (a || b) {
 662                struct line_log_data *src;
 663                struct line_log_data *src2 = NULL;
 664                struct line_log_data *d;
 665                int cmp;
 666                if (!a)
 667                        cmp = 1;
 668                else if (!b)
 669                        cmp = -1;
 670                else
 671                        cmp = strcmp(a->path, b->path);
 672                if (cmp < 0) {
 673                        src = a;
 674                        a = a->next;
 675                } else if (cmp == 0) {
 676                        src = a;
 677                        a = a->next;
 678                        src2 = b;
 679                        b = b->next;
 680                } else {
 681                        src = b;
 682                        b = b->next;
 683                }
 684                d = xmalloc(sizeof(struct line_log_data));
 685                line_log_data_init(d);
 686                d->path = xstrdup(src->path);
 687                *pp = d;
 688                pp = &d->next;
 689                if (src2)
 690                        range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 691                else
 692                        range_set_copy(&d->ranges, &src->ranges);
 693        }
 694
 695        return head;
 696}
 697
 698static void add_line_range(struct rev_info *revs, struct commit *commit,
 699                           struct line_log_data *range)
 700{
 701        struct line_log_data *old_line = NULL;
 702        struct line_log_data *new_line = NULL;
 703
 704        old_line = lookup_decoration(&revs->line_log_data, &commit->object);
 705        if (old_line && range) {
 706                new_line = line_log_data_merge(old_line, range);
 707                free_line_log_data(old_line);
 708        } else if (range)
 709                new_line = line_log_data_copy(range);
 710
 711        if (new_line)
 712                add_decoration(&revs->line_log_data, &commit->object, new_line);
 713}
 714
 715static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 716{
 717        struct line_log_data *r;
 718        r = lookup_decoration(&revs->line_log_data, &commit->object);
 719        if (!r)
 720                return;
 721        free_line_log_data(r);
 722        add_decoration(&revs->line_log_data, &commit->object, NULL);
 723}
 724
 725static struct line_log_data *lookup_line_range(struct rev_info *revs,
 726                                               struct commit *commit)
 727{
 728        struct line_log_data *ret = NULL;
 729        struct line_log_data *d;
 730
 731        ret = lookup_decoration(&revs->line_log_data, &commit->object);
 732
 733        for (d = ret; d; d = d->next)
 734                range_set_check_invariants(&d->ranges);
 735
 736        return ret;
 737}
 738
 739void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 740{
 741        struct commit *commit = NULL;
 742        struct line_log_data *range;
 743
 744        commit = check_single_commit(rev);
 745        range = parse_lines(rev->diffopt.repo, commit, prefix, args);
 746        add_line_range(rev, commit, range);
 747
 748        if (!rev->diffopt.detect_rename) {
 749                struct line_log_data *r;
 750                struct argv_array array = ARGV_ARRAY_INIT;
 751                const char **paths;
 752
 753                for (r = range; r; r = r->next)
 754                        argv_array_push(&array, r->path);
 755                paths = argv_array_detach(&array);
 756
 757                parse_pathspec(&rev->diffopt.pathspec, 0,
 758                               PATHSPEC_PREFER_FULL, "", paths);
 759                /* strings are now owned by pathspec */
 760                free(paths);
 761        }
 762}
 763
 764static void move_diff_queue(struct diff_queue_struct *dst,
 765                            struct diff_queue_struct *src)
 766{
 767        assert(src != dst);
 768        memcpy(dst, src, sizeof(struct diff_queue_struct));
 769        DIFF_QUEUE_CLEAR(src);
 770}
 771
 772static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 773{
 774        int i;
 775        struct diff_queue_struct outq;
 776        DIFF_QUEUE_CLEAR(&outq);
 777
 778        for (i = 0; i < diff_queued_diff.nr; i++) {
 779                struct diff_filepair *p = diff_queued_diff.queue[i];
 780                struct line_log_data *rg = NULL;
 781
 782                if (!DIFF_FILE_VALID(p->two)) {
 783                        if (keep_deletions)
 784                                diff_q(&outq, p);
 785                        else
 786                                diff_free_filepair(p);
 787                        continue;
 788                }
 789                for (rg = range; rg; rg = rg->next) {
 790                        if (!strcmp(rg->path, p->two->path))
 791                                break;
 792                }
 793                if (rg)
 794                        diff_q(&outq, p);
 795                else
 796                        diff_free_filepair(p);
 797        }
 798        free(diff_queued_diff.queue);
 799        diff_queued_diff = outq;
 800}
 801
 802static inline int diff_might_be_rename(void)
 803{
 804        int i;
 805        for (i = 0; i < diff_queued_diff.nr; i++)
 806                if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 807                        /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 808                        /*      diff_queued_diff.queue[i]->two->path); */
 809                        return 1;
 810                }
 811        return 0;
 812}
 813
 814static void queue_diffs(struct line_log_data *range,
 815                        struct diff_options *opt,
 816                        struct diff_queue_struct *queue,
 817                        struct commit *commit, struct commit *parent)
 818{
 819        assert(commit);
 820
 821        DIFF_QUEUE_CLEAR(&diff_queued_diff);
 822        diff_tree_oid(parent ? get_commit_tree_oid(parent) : NULL,
 823                      get_commit_tree_oid(commit), "", opt);
 824        if (opt->detect_rename) {
 825                filter_diffs_for_paths(range, 1);
 826                if (diff_might_be_rename())
 827                        diffcore_std(opt);
 828                filter_diffs_for_paths(range, 0);
 829        }
 830        move_diff_queue(queue, &diff_queued_diff);
 831}
 832
 833static char *get_nth_line(long line, unsigned long *ends, void *data)
 834{
 835        if (line == 0)
 836                return (char *)data;
 837        else
 838                return (char *)data + ends[line] + 1;
 839}
 840
 841static void print_line(const char *prefix, char first,
 842                       long line, unsigned long *ends, void *data,
 843                       const char *color, const char *reset, FILE *file)
 844{
 845        char *begin = get_nth_line(line, ends, data);
 846        char *end = get_nth_line(line+1, ends, data);
 847        int had_nl = 0;
 848
 849        if (end > begin && end[-1] == '\n') {
 850                end--;
 851                had_nl = 1;
 852        }
 853
 854        fputs(prefix, file);
 855        fputs(color, file);
 856        putc(first, file);
 857        fwrite(begin, 1, end-begin, file);
 858        fputs(reset, file);
 859        putc('\n', file);
 860        if (!had_nl)
 861                fputs("\\ No newline at end of file\n", file);
 862}
 863
 864static char *output_prefix(struct diff_options *opt)
 865{
 866        char *prefix = "";
 867
 868        if (opt->output_prefix) {
 869                struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 870                prefix = sb->buf;
 871        }
 872
 873        return prefix;
 874}
 875
 876static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 877{
 878        unsigned int i, j = 0;
 879        long p_lines, t_lines;
 880        unsigned long *p_ends = NULL, *t_ends = NULL;
 881        struct diff_filepair *pair = range->pair;
 882        struct diff_ranges *diff = &range->diff;
 883
 884        struct diff_options *opt = &rev->diffopt;
 885        char *prefix = output_prefix(opt);
 886        const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 887        const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 888        const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 889        const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 890        const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 891        const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 892
 893        if (!pair || !diff)
 894                return;
 895
 896        if (pair->one->oid_valid)
 897                fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
 898        fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);
 899
 900        fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 901        fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 902               pair->one->oid_valid ? "a/" : "",
 903               pair->one->oid_valid ? pair->one->path : "/dev/null",
 904               c_reset);
 905        fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 906        for (i = 0; i < range->ranges.nr; i++) {
 907                long p_start, p_end;
 908                long t_start = range->ranges.ranges[i].start;
 909                long t_end = range->ranges.ranges[i].end;
 910                long t_cur = t_start;
 911                unsigned int j_last;
 912
 913                while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 914                        j++;
 915                if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 916                        continue;
 917
 918                /* Scan ahead to determine the last diff that falls in this range */
 919                j_last = j;
 920                while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 921                        j_last++;
 922                if (j_last > j)
 923                        j_last--;
 924
 925                /*
 926                 * Compute parent hunk headers: we know that the diff
 927                 * has the correct line numbers (but not all hunks).
 928                 * So it suffices to shift the start/end according to
 929                 * the line numbers of the first/last hunk(s) that
 930                 * fall in this range.
 931                 */
 932                if (t_start < diff->target.ranges[j].start)
 933                        p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 934                else
 935                        p_start = diff->parent.ranges[j].start;
 936                if (t_end > diff->target.ranges[j_last].end)
 937                        p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 938                else
 939                        p_end = diff->parent.ranges[j_last].end;
 940
 941                if (!p_start && !p_end) {
 942                        p_start = -1;
 943                        p_end = -1;
 944                }
 945
 946                /* Now output a diff hunk for this range */
 947                fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 948                       prefix, c_frag,
 949                       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 950                       c_reset);
 951                while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 952                        int k;
 953                        for (; t_cur < diff->target.ranges[j].start; t_cur++)
 954                                print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 955                                           c_context, c_reset, opt->file);
 956                        for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 957                                print_line(prefix, '-', k, p_ends, pair->one->data,
 958                                           c_old, c_reset, opt->file);
 959                        for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 960                                print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 961                                           c_new, c_reset, opt->file);
 962                        j++;
 963                }
 964                for (; t_cur < t_end; t_cur++)
 965                        print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 966                                   c_context, c_reset, opt->file);
 967        }
 968
 969        free(p_ends);
 970        free(t_ends);
 971}
 972
 973/*
 974 * NEEDSWORK: manually building a diff here is not the Right
 975 * Thing(tm).  log -L should be built into the diff pipeline.
 976 */
 977static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 978{
 979        fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
 980        while (range) {
 981                dump_diff_hacky_one(rev, range);
 982                range = range->next;
 983        }
 984}
 985
 986/*
 987 * Unlike most other functions, this destructively operates on
 988 * 'range'.
 989 */
 990static int process_diff_filepair(struct rev_info *rev,
 991                                 struct diff_filepair *pair,
 992                                 struct line_log_data *range,
 993                                 struct diff_ranges **diff_out)
 994{
 995        struct line_log_data *rg = range;
 996        struct range_set tmp;
 997        struct diff_ranges diff;
 998        mmfile_t file_parent, file_target;
 999
1000        assert(pair->two->path);
1001        while (rg) {
1002                assert(rg->path);
1003                if (!strcmp(rg->path, pair->two->path))
1004                        break;
1005                rg = rg->next;
1006        }
1007
1008        if (!rg)
1009                return 0;
1010        if (rg->ranges.nr == 0)
1011                return 0;
1012
1013        assert(pair->two->oid_valid);
1014        diff_populate_filespec(rev->diffopt.repo, pair->two, 0);
1015        file_target.ptr = pair->two->data;
1016        file_target.size = pair->two->size;
1017
1018        if (pair->one->oid_valid) {
1019                diff_populate_filespec(rev->diffopt.repo, pair->one, 0);
1020                file_parent.ptr = pair->one->data;
1021                file_parent.size = pair->one->size;
1022        } else {
1023                file_parent.ptr = "";
1024                file_parent.size = 0;
1025        }
1026
1027        diff_ranges_init(&diff);
1028        if (collect_diff(&file_parent, &file_target, &diff))
1029                die("unable to generate diff for %s", pair->one->path);
1030
1031        /* NEEDSWORK should apply some heuristics to prevent mismatches */
1032        free(rg->path);
1033        rg->path = xstrdup(pair->one->path);
1034
1035        range_set_init(&tmp, 0);
1036        range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1037        range_set_release(&rg->ranges);
1038        range_set_move(&rg->ranges, &tmp);
1039
1040        diff_ranges_release(&diff);
1041
1042        return ((*diff_out)->parent.nr > 0);
1043}
1044
1045static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1046{
1047        struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
1048        new_filepair->one = pair->one;
1049        new_filepair->two = pair->two;
1050        new_filepair->one->count++;
1051        new_filepair->two->count++;
1052        return new_filepair;
1053}
1054
1055static void free_diffqueues(int n, struct diff_queue_struct *dq)
1056{
1057        int i, j;
1058        for (i = 0; i < n; i++)
1059                for (j = 0; j < dq[i].nr; j++)
1060                        diff_free_filepair(dq[i].queue[j]);
1061        free(dq);
1062}
1063
1064static int process_all_files(struct line_log_data **range_out,
1065                             struct rev_info *rev,
1066                             struct diff_queue_struct *queue,
1067                             struct line_log_data *range)
1068{
1069        int i, changed = 0;
1070
1071        *range_out = line_log_data_copy(range);
1072
1073        for (i = 0; i < queue->nr; i++) {
1074                struct diff_ranges *pairdiff = NULL;
1075                struct diff_filepair *pair = queue->queue[i];
1076                if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1077                        /*
1078                         * Store away the diff for later output.  We
1079                         * tuck it in the ranges we got as _input_,
1080                         * since that's the commit that caused the
1081                         * diff.
1082                         *
1083                         * NEEDSWORK not enough when we get around to
1084                         * doing something interesting with merges;
1085                         * currently each invocation on a merge parent
1086                         * trashes the previous one's diff.
1087                         *
1088                         * NEEDSWORK tramples over data structures not owned here
1089                         */
1090                        struct line_log_data *rg = range;
1091                        changed++;
1092                        while (rg && strcmp(rg->path, pair->two->path))
1093                                rg = rg->next;
1094                        assert(rg);
1095                        rg->pair = diff_filepair_dup(queue->queue[i]);
1096                        memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1097                }
1098                free(pairdiff);
1099        }
1100
1101        return changed;
1102}
1103
1104int line_log_print(struct rev_info *rev, struct commit *commit)
1105{
1106        struct line_log_data *range = lookup_line_range(rev, commit);
1107
1108        show_log(rev);
1109        dump_diff_hacky(rev, range);
1110        return 1;
1111}
1112
1113static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1114                                          struct line_log_data *range)
1115{
1116        struct commit *parent = NULL;
1117        struct diff_queue_struct queue;
1118        struct line_log_data *parent_range;
1119        int changed;
1120
1121        if (commit->parents)
1122                parent = commit->parents->item;
1123
1124        queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1125        changed = process_all_files(&parent_range, rev, &queue, range);
1126        if (parent)
1127                add_line_range(rev, parent, parent_range);
1128        free_line_log_data(parent_range);
1129        return changed;
1130}
1131
1132static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1133                                       struct line_log_data *range)
1134{
1135        struct diff_queue_struct *diffqueues;
1136        struct line_log_data **cand;
1137        struct commit **parents;
1138        struct commit_list *p;
1139        int i;
1140        int nparents = commit_list_count(commit->parents);
1141
1142        if (nparents > 1 && rev->first_parent_only)
1143                nparents = 1;
1144
1145        ALLOC_ARRAY(diffqueues, nparents);
1146        ALLOC_ARRAY(cand, nparents);
1147        ALLOC_ARRAY(parents, nparents);
1148
1149        p = commit->parents;
1150        for (i = 0; i < nparents; i++) {
1151                parents[i] = p->item;
1152                p = p->next;
1153                queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1154        }
1155
1156        for (i = 0; i < nparents; i++) {
1157                int changed;
1158                cand[i] = NULL;
1159                changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1160                if (!changed) {
1161                        /*
1162                         * This parent can take all the blame, so we
1163                         * don't follow any other path in history
1164                         */
1165                        add_line_range(rev, parents[i], cand[i]);
1166                        clear_commit_line_range(rev, commit);
1167                        commit_list_append(parents[i], &commit->parents);
1168                        free(parents);
1169                        free(cand);
1170                        free_diffqueues(nparents, diffqueues);
1171                        /* NEEDSWORK leaking like a sieve */
1172                        return 0;
1173                }
1174        }
1175
1176        /*
1177         * No single parent took the blame.  We add the candidates
1178         * from the above loop to the parents.
1179         */
1180        for (i = 0; i < nparents; i++) {
1181                add_line_range(rev, parents[i], cand[i]);
1182        }
1183
1184        clear_commit_line_range(rev, commit);
1185        free(parents);
1186        free(cand);
1187        free_diffqueues(nparents, diffqueues);
1188        return 1;
1189
1190        /* NEEDSWORK evil merge detection stuff */
1191        /* NEEDSWORK leaking like a sieve */
1192}
1193
1194static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1195{
1196        struct line_log_data *range = lookup_line_range(rev, commit);
1197        int changed = 0;
1198
1199        if (range) {
1200                if (!commit->parents || !commit->parents->next)
1201                        changed = process_ranges_ordinary_commit(rev, commit, range);
1202                else
1203                        changed = process_ranges_merge_commit(rev, commit, range);
1204        }
1205
1206        if (!changed)
1207                commit->object.flags |= TREESAME;
1208
1209        return changed;
1210}
1211
1212static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1213{
1214        for (;;) {
1215                struct commit *p = *pp;
1216                if (p->parents && p->parents->next)
1217                        return rewrite_one_ok;
1218                if (p->object.flags & UNINTERESTING)
1219                        return rewrite_one_ok;
1220                if (!(p->object.flags & TREESAME))
1221                        return rewrite_one_ok;
1222                if (!p->parents)
1223                        return rewrite_one_noparents;
1224                *pp = p->parents->item;
1225        }
1226}
1227
1228int line_log_filter(struct rev_info *rev)
1229{
1230        struct commit *commit;
1231        struct commit_list *list = rev->commits;
1232        struct commit_list *out = NULL, **pp = &out;
1233
1234        while (list) {
1235                struct commit_list *to_free = NULL;
1236                commit = list->item;
1237                if (process_ranges_arbitrary_commit(rev, commit)) {
1238                        *pp = list;
1239                        pp = &list->next;
1240                } else
1241                        to_free = list;
1242                list = list->next;
1243                free(to_free);
1244        }
1245        *pp = NULL;
1246
1247        for (list = out; list; list = list->next)
1248                rewrite_parents(rev, list->item, line_log_rewrite_one);
1249
1250        rev->commits = out;
1251
1252        return 0;
1253}