line-log.con commit Merge branch 'nd/multiple-work-trees' (7783eb2)
   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
  18static void range_set_grow(struct range_set *rs, size_t extra)
  19{
  20        ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
  21}
  22
  23/* Either initialization would be fine */
  24#define RANGE_SET_INIT {0}
  25
  26void range_set_init(struct range_set *rs, size_t prealloc)
  27{
  28        rs->alloc = rs->nr = 0;
  29        rs->ranges = NULL;
  30        if (prealloc)
  31                range_set_grow(rs, prealloc);
  32}
  33
  34void range_set_release(struct range_set *rs)
  35{
  36        free(rs->ranges);
  37        rs->alloc = rs->nr = 0;
  38        rs->ranges = NULL;
  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        memcpy(dst->ranges, src->ranges, src->nr*sizeof(struct range_set));
  46        dst->nr = src->nr;
  47}
  48static void range_set_move(struct range_set *dst, struct range_set *src)
  49{
  50        range_set_release(dst);
  51        dst->ranges = src->ranges;
  52        dst->nr = src->nr;
  53        dst->alloc = src->alloc;
  54        src->ranges = NULL;
  55        src->alloc = src->nr = 0;
  56}
  57
  58/* tack on a _new_ range _at the end_ */
  59void range_set_append_unsafe(struct range_set *rs, long a, long b)
  60{
  61        assert(a <= b);
  62        range_set_grow(rs, 1);
  63        rs->ranges[rs->nr].start = a;
  64        rs->ranges[rs->nr].end = b;
  65        rs->nr++;
  66}
  67
  68void range_set_append(struct range_set *rs, long a, long b)
  69{
  70        assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
  71        range_set_append_unsafe(rs, a, b);
  72}
  73
  74static int range_cmp(const void *_r, const void *_s)
  75{
  76        const struct range *r = _r;
  77        const struct range *s = _s;
  78
  79        /* this could be simply 'return r.start-s.start', but for the types */
  80        if (r->start == s->start)
  81                return 0;
  82        if (r->start < s->start)
  83                return -1;
  84        return 1;
  85}
  86
  87/*
  88 * Check that the ranges are non-empty, sorted and non-overlapping
  89 */
  90static void range_set_check_invariants(struct range_set *rs)
  91{
  92        int i;
  93
  94        if (!rs)
  95                return;
  96
  97        if (rs->nr)
  98                assert(rs->ranges[0].start < rs->ranges[0].end);
  99
 100        for (i = 1; i < rs->nr; i++) {
 101                assert(rs->ranges[i-1].end < rs->ranges[i].start);
 102                assert(rs->ranges[i].start < rs->ranges[i].end);
 103        }
 104}
 105
 106/*
 107 * In-place pass of sorting and merging the ranges in the range set,
 108 * to establish the invariants when we get the ranges from the user
 109 */
 110void sort_and_merge_range_set(struct range_set *rs)
 111{
 112        int i;
 113        int o = 0; /* output cursor */
 114
 115        qsort(rs->ranges, rs->nr, sizeof(struct range), range_cmp);
 116
 117        for (i = 0; i < rs->nr; i++) {
 118                if (rs->ranges[i].start == rs->ranges[i].end)
 119                        continue;
 120                if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
 121                        if (rs->ranges[o-1].end < rs->ranges[i].end)
 122                                rs->ranges[o-1].end = rs->ranges[i].end;
 123                } else {
 124                        rs->ranges[o].start = rs->ranges[i].start;
 125                        rs->ranges[o].end = rs->ranges[i].end;
 126                        o++;
 127                }
 128        }
 129        assert(o <= rs->nr);
 130        rs->nr = o;
 131
 132        range_set_check_invariants(rs);
 133}
 134
 135/*
 136 * Union of range sets (i.e., sets of line numbers).  Used to merge
 137 * them when searches meet at a common ancestor.
 138 *
 139 * This is also where the ranges are consolidated into canonical form:
 140 * overlapping and adjacent ranges are merged, and empty ranges are
 141 * removed.
 142 */
 143static void range_set_union(struct range_set *out,
 144                             struct range_set *a, struct range_set *b)
 145{
 146        int i = 0, j = 0, o = 0;
 147        struct range *ra = a->ranges;
 148        struct range *rb = b->ranges;
 149        /* cannot make an alias of out->ranges: it may change during grow */
 150
 151        assert(out->nr == 0);
 152        while (i < a->nr || j < b->nr) {
 153                struct range *new;
 154                if (i < a->nr && j < b->nr) {
 155                        if (ra[i].start < rb[j].start)
 156                                new = &ra[i++];
 157                        else if (ra[i].start > rb[j].start)
 158                                new = &rb[j++];
 159                        else if (ra[i].end < rb[j].end)
 160                                new = &ra[i++];
 161                        else
 162                                new = &rb[j++];
 163                } else if (i < a->nr)      /* b exhausted */
 164                        new = &ra[i++];
 165                else                       /* a exhausted */
 166                        new = &rb[j++];
 167                if (new->start == new->end)
 168                        ; /* empty range */
 169                else if (!o || out->ranges[o-1].end < new->start) {
 170                        range_set_grow(out, 1);
 171                        out->ranges[o].start = new->start;
 172                        out->ranges[o].end = new->end;
 173                        o++;
 174                } else if (out->ranges[o-1].end < new->end) {
 175                        out->ranges[o-1].end = new->end;
 176                }
 177        }
 178        out->nr = o;
 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        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 void 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        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        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        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                while (obj->type == OBJ_TAG)
 483                        obj = deref_tag(obj, NULL, 0);
 484                if (obj->type != OBJ_COMMIT)
 485                        die("Non commit %s?", revs->pending.objects[i].name);
 486                if (commit)
 487                        die("More than one commit to dig from: %s and %s?",
 488                            revs->pending.objects[i].name,
 489                            revs->pending.objects[found].name);
 490                commit = obj;
 491                found = i;
 492        }
 493
 494        if (!commit)
 495                die("No commit specified?");
 496
 497        return (struct commit *) commit;
 498}
 499
 500static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
 501{
 502        unsigned mode;
 503        unsigned char sha1[20];
 504
 505        if (get_tree_entry(commit->object.sha1, spec->path,
 506                           sha1, &mode))
 507                die("There is no path %s in the commit", spec->path);
 508        fill_filespec(spec, sha1, 1, mode);
 509
 510        return;
 511}
 512
 513static void fill_line_ends(struct diff_filespec *spec, 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(spec, 0))
 522                die("Cannot read blob %s", sha1_to_hex(spec->sha1));
 523
 524        ends = xmalloc(size * sizeof(*ends));
 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 commit *commit, const char *prefix, struct string_list *args)
 561{
 562        long lines = 0;
 563        unsigned long *ends = NULL;
 564        struct nth_line_cb cb_data;
 565        struct string_list_item *item;
 566        struct line_log_data *ranges = NULL;
 567        struct line_log_data *p;
 568
 569        for_each_string_list_item(item, args) {
 570                const char *name_part, *range_part;
 571                char *full_name;
 572                struct diff_filespec *spec;
 573                long begin = 0, end = 0;
 574                long anchor;
 575
 576                name_part = skip_range_arg(item->string);
 577                if (!name_part || *name_part != ':' || !name_part[1])
 578                        die("-L argument not 'start,end:file' or ':funcname:file': %s",
 579                            item->string);
 580                range_part = xstrndup(item->string, name_part - item->string);
 581                name_part++;
 582
 583                full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 584                                        name_part);
 585
 586                spec = alloc_filespec(full_name);
 587                fill_blob_sha1(commit, spec);
 588                fill_line_ends(spec, &lines, &ends);
 589                cb_data.spec = spec;
 590                cb_data.lines = lines;
 591                cb_data.line_ends = ends;
 592
 593                p = search_line_log_data(ranges, full_name, NULL);
 594                if (p && p->ranges.nr)
 595                        anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 596                else
 597                        anchor = 1;
 598
 599                if (parse_range_arg(range_part, nth_line, &cb_data,
 600                                    lines, anchor, &begin, &end,
 601                                    full_name))
 602                        die("malformed -L argument '%s'", range_part);
 603                if (lines < end || ((lines || begin) && lines < begin))
 604                        die("file %s has only %lu lines", name_part, lines);
 605                if (begin < 1)
 606                        begin = 1;
 607                if (end < 1)
 608                        end = lines;
 609                begin--;
 610                line_log_data_insert(&ranges, full_name, begin, end);
 611
 612                free_filespec(spec);
 613                free(ends);
 614                ends = NULL;
 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 = NULL;
 702        struct line_log_data *new = NULL;
 703
 704        old = lookup_decoration(&revs->line_log_data, &commit->object);
 705        if (old && range) {
 706                new = line_log_data_merge(old, range);
 707                free_line_log_data(old);
 708        } else if (range)
 709                new = line_log_data_copy(range);
 710
 711        if (new)
 712                add_decoration(&revs->line_log_data, &commit->object, new);
 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(commit, prefix, args);
 746        add_line_range(rev, commit, range);
 747
 748        if (!rev->diffopt.detect_rename) {
 749                int i, count = 0;
 750                struct line_log_data *r = range;
 751                const char **paths;
 752                while (r) {
 753                        count++;
 754                        r = r->next;
 755                }
 756                paths = xmalloc((count+1)*sizeof(char *));
 757                r = range;
 758                for (i = 0; i < count; i++) {
 759                        paths[i] = xstrdup(r->path);
 760                        r = r->next;
 761                }
 762                paths[count] = NULL;
 763                parse_pathspec(&rev->diffopt.pathspec, 0,
 764                               PATHSPEC_PREFER_FULL, "", paths);
 765                free(paths);
 766        }
 767}
 768
 769static void move_diff_queue(struct diff_queue_struct *dst,
 770                            struct diff_queue_struct *src)
 771{
 772        assert(src != dst);
 773        memcpy(dst, src, sizeof(struct diff_queue_struct));
 774        DIFF_QUEUE_CLEAR(src);
 775}
 776
 777static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 778{
 779        int i;
 780        struct diff_queue_struct outq;
 781        DIFF_QUEUE_CLEAR(&outq);
 782
 783        for (i = 0; i < diff_queued_diff.nr; i++) {
 784                struct diff_filepair *p = diff_queued_diff.queue[i];
 785                struct line_log_data *rg = NULL;
 786
 787                if (!DIFF_FILE_VALID(p->two)) {
 788                        if (keep_deletions)
 789                                diff_q(&outq, p);
 790                        else
 791                                diff_free_filepair(p);
 792                        continue;
 793                }
 794                for (rg = range; rg; rg = rg->next) {
 795                        if (!strcmp(rg->path, p->two->path))
 796                                break;
 797                }
 798                if (rg)
 799                        diff_q(&outq, p);
 800                else
 801                        diff_free_filepair(p);
 802        }
 803        free(diff_queued_diff.queue);
 804        diff_queued_diff = outq;
 805}
 806
 807static inline int diff_might_be_rename(void)
 808{
 809        int i;
 810        for (i = 0; i < diff_queued_diff.nr; i++)
 811                if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 812                        /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 813                        /*      diff_queued_diff.queue[i]->two->path); */
 814                        return 1;
 815                }
 816        return 0;
 817}
 818
 819static void queue_diffs(struct line_log_data *range,
 820                        struct diff_options *opt,
 821                        struct diff_queue_struct *queue,
 822                        struct commit *commit, struct commit *parent)
 823{
 824        assert(commit);
 825
 826        DIFF_QUEUE_CLEAR(&diff_queued_diff);
 827        diff_tree_sha1(parent ? parent->tree->object.sha1 : NULL,
 828                        commit->tree->object.sha1, "", opt);
 829        if (opt->detect_rename) {
 830                filter_diffs_for_paths(range, 1);
 831                if (diff_might_be_rename())
 832                        diffcore_std(opt);
 833                filter_diffs_for_paths(range, 0);
 834        }
 835        move_diff_queue(queue, &diff_queued_diff);
 836}
 837
 838static char *get_nth_line(long line, unsigned long *ends, void *data)
 839{
 840        if (line == 0)
 841                return (char *)data;
 842        else
 843                return (char *)data + ends[line] + 1;
 844}
 845
 846static void print_line(const char *prefix, char first,
 847                       long line, unsigned long *ends, void *data,
 848                       const char *color, const char *reset)
 849{
 850        char *begin = get_nth_line(line, ends, data);
 851        char *end = get_nth_line(line+1, ends, data);
 852        int had_nl = 0;
 853
 854        if (end > begin && end[-1] == '\n') {
 855                end--;
 856                had_nl = 1;
 857        }
 858
 859        fputs(prefix, stdout);
 860        fputs(color, stdout);
 861        putchar(first);
 862        fwrite(begin, 1, end-begin, stdout);
 863        fputs(reset, stdout);
 864        putchar('\n');
 865        if (!had_nl)
 866                fputs("\\ No newline at end of file\n", stdout);
 867}
 868
 869static char *output_prefix(struct diff_options *opt)
 870{
 871        char *prefix = "";
 872
 873        if (opt->output_prefix) {
 874                struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 875                prefix = sb->buf;
 876        }
 877
 878        return prefix;
 879}
 880
 881static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 882{
 883        int i, j = 0;
 884        long p_lines, t_lines;
 885        unsigned long *p_ends = NULL, *t_ends = NULL;
 886        struct diff_filepair *pair = range->pair;
 887        struct diff_ranges *diff = &range->diff;
 888
 889        struct diff_options *opt = &rev->diffopt;
 890        char *prefix = output_prefix(opt);
 891        const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 892        const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 893        const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 894        const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 895        const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 896        const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 897
 898        if (!pair || !diff)
 899                return;
 900
 901        if (pair->one->sha1_valid)
 902                fill_line_ends(pair->one, &p_lines, &p_ends);
 903        fill_line_ends(pair->two, &t_lines, &t_ends);
 904
 905        printf("%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 906        printf("%s%s--- %s%s%s\n", prefix, c_meta,
 907               pair->one->sha1_valid ? "a/" : "",
 908               pair->one->sha1_valid ? pair->one->path : "/dev/null",
 909               c_reset);
 910        printf("%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 911        for (i = 0; i < range->ranges.nr; i++) {
 912                long p_start, p_end;
 913                long t_start = range->ranges.ranges[i].start;
 914                long t_end = range->ranges.ranges[i].end;
 915                long t_cur = t_start;
 916                int j_last;
 917
 918                while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 919                        j++;
 920                if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 921                        continue;
 922
 923                /* Scan ahead to determine the last diff that falls in this range */
 924                j_last = j;
 925                while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 926                        j_last++;
 927                if (j_last > j)
 928                        j_last--;
 929
 930                /*
 931                 * Compute parent hunk headers: we know that the diff
 932                 * has the correct line numbers (but not all hunks).
 933                 * So it suffices to shift the start/end according to
 934                 * the line numbers of the first/last hunk(s) that
 935                 * fall in this range.
 936                 */
 937                if (t_start < diff->target.ranges[j].start)
 938                        p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 939                else
 940                        p_start = diff->parent.ranges[j].start;
 941                if (t_end > diff->target.ranges[j_last].end)
 942                        p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 943                else
 944                        p_end = diff->parent.ranges[j_last].end;
 945
 946                if (!p_start && !p_end) {
 947                        p_start = -1;
 948                        p_end = -1;
 949                }
 950
 951                /* Now output a diff hunk for this range */
 952                printf("%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 953                       prefix, c_frag,
 954                       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 955                       c_reset);
 956                while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 957                        int k;
 958                        for (; t_cur < diff->target.ranges[j].start; t_cur++)
 959                                print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 960                                           c_context, c_reset);
 961                        for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 962                                print_line(prefix, '-', k, p_ends, pair->one->data,
 963                                           c_old, c_reset);
 964                        for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 965                                print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 966                                           c_new, c_reset);
 967                        j++;
 968                }
 969                for (; t_cur < t_end; t_cur++)
 970                        print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 971                                   c_context, c_reset);
 972        }
 973
 974        free(p_ends);
 975        free(t_ends);
 976}
 977
 978/*
 979 * NEEDSWORK: manually building a diff here is not the Right
 980 * Thing(tm).  log -L should be built into the diff pipeline.
 981 */
 982static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 983{
 984        puts(output_prefix(&rev->diffopt));
 985        while (range) {
 986                dump_diff_hacky_one(rev, range);
 987                range = range->next;
 988        }
 989}
 990
 991/*
 992 * Unlike most other functions, this destructively operates on
 993 * 'range'.
 994 */
 995static int process_diff_filepair(struct rev_info *rev,
 996                                 struct diff_filepair *pair,
 997                                 struct line_log_data *range,
 998                                 struct diff_ranges **diff_out)
 999{
1000        struct line_log_data *rg = range;
1001        struct range_set tmp;
1002        struct diff_ranges diff;
1003        mmfile_t file_parent, file_target;
1004
1005        assert(pair->two->path);
1006        while (rg) {
1007                assert(rg->path);
1008                if (!strcmp(rg->path, pair->two->path))
1009                        break;
1010                rg = rg->next;
1011        }
1012
1013        if (!rg)
1014                return 0;
1015        if (rg->ranges.nr == 0)
1016                return 0;
1017
1018        assert(pair->two->sha1_valid);
1019        diff_populate_filespec(pair->two, 0);
1020        file_target.ptr = pair->two->data;
1021        file_target.size = pair->two->size;
1022
1023        if (pair->one->sha1_valid) {
1024                diff_populate_filespec(pair->one, 0);
1025                file_parent.ptr = pair->one->data;
1026                file_parent.size = pair->one->size;
1027        } else {
1028                file_parent.ptr = "";
1029                file_parent.size = 0;
1030        }
1031
1032        diff_ranges_init(&diff);
1033        collect_diff(&file_parent, &file_target, &diff);
1034
1035        /* NEEDSWORK should apply some heuristics to prevent mismatches */
1036        free(rg->path);
1037        rg->path = xstrdup(pair->one->path);
1038
1039        range_set_init(&tmp, 0);
1040        range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1041        range_set_release(&rg->ranges);
1042        range_set_move(&rg->ranges, &tmp);
1043
1044        diff_ranges_release(&diff);
1045
1046        return ((*diff_out)->parent.nr > 0);
1047}
1048
1049static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1050{
1051        struct diff_filepair *new = xmalloc(sizeof(struct diff_filepair));
1052        new->one = pair->one;
1053        new->two = pair->two;
1054        new->one->count++;
1055        new->two->count++;
1056        return new;
1057}
1058
1059static void free_diffqueues(int n, struct diff_queue_struct *dq)
1060{
1061        int i, j;
1062        for (i = 0; i < n; i++)
1063                for (j = 0; j < dq[i].nr; j++)
1064                        diff_free_filepair(dq[i].queue[j]);
1065        free(dq);
1066}
1067
1068static int process_all_files(struct line_log_data **range_out,
1069                             struct rev_info *rev,
1070                             struct diff_queue_struct *queue,
1071                             struct line_log_data *range)
1072{
1073        int i, changed = 0;
1074
1075        *range_out = line_log_data_copy(range);
1076
1077        for (i = 0; i < queue->nr; i++) {
1078                struct diff_ranges *pairdiff = NULL;
1079                struct diff_filepair *pair = queue->queue[i];
1080                if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1081                        /*
1082                         * Store away the diff for later output.  We
1083                         * tuck it in the ranges we got as _input_,
1084                         * since that's the commit that caused the
1085                         * diff.
1086                         *
1087                         * NEEDSWORK not enough when we get around to
1088                         * doing something interesting with merges;
1089                         * currently each invocation on a merge parent
1090                         * trashes the previous one's diff.
1091                         *
1092                         * NEEDSWORK tramples over data structures not owned here
1093                         */
1094                        struct line_log_data *rg = range;
1095                        changed++;
1096                        while (rg && strcmp(rg->path, pair->two->path))
1097                                rg = rg->next;
1098                        assert(rg);
1099                        rg->pair = diff_filepair_dup(queue->queue[i]);
1100                        memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1101                }
1102                free(pairdiff);
1103        }
1104
1105        return changed;
1106}
1107
1108int line_log_print(struct rev_info *rev, struct commit *commit)
1109{
1110        struct line_log_data *range = lookup_line_range(rev, commit);
1111
1112        show_log(rev);
1113        dump_diff_hacky(rev, range);
1114        return 1;
1115}
1116
1117static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1118                                          struct line_log_data *range)
1119{
1120        struct commit *parent = NULL;
1121        struct diff_queue_struct queue;
1122        struct line_log_data *parent_range;
1123        int changed;
1124
1125        if (commit->parents)
1126                parent = commit->parents->item;
1127
1128        queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1129        changed = process_all_files(&parent_range, rev, &queue, range);
1130        if (parent)
1131                add_line_range(rev, parent, parent_range);
1132        return changed;
1133}
1134
1135static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1136                                       struct line_log_data *range)
1137{
1138        struct diff_queue_struct *diffqueues;
1139        struct line_log_data **cand;
1140        struct commit **parents;
1141        struct commit_list *p;
1142        int i;
1143        int nparents = commit_list_count(commit->parents);
1144
1145        if (nparents > 1 && rev->first_parent_only)
1146                nparents = 1;
1147
1148        diffqueues = xmalloc(nparents * sizeof(*diffqueues));
1149        cand = xmalloc(nparents * sizeof(*cand));
1150        parents = xmalloc(nparents * sizeof(*parents));
1151
1152        p = commit->parents;
1153        for (i = 0; i < nparents; i++) {
1154                parents[i] = p->item;
1155                p = p->next;
1156                queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1157        }
1158
1159        for (i = 0; i < nparents; i++) {
1160                int changed;
1161                cand[i] = NULL;
1162                changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1163                if (!changed) {
1164                        /*
1165                         * This parent can take all the blame, so we
1166                         * don't follow any other path in history
1167                         */
1168                        add_line_range(rev, parents[i], cand[i]);
1169                        clear_commit_line_range(rev, commit);
1170                        commit_list_append(parents[i], &commit->parents);
1171                        free(parents);
1172                        free(cand);
1173                        free_diffqueues(nparents, diffqueues);
1174                        /* NEEDSWORK leaking like a sieve */
1175                        return 0;
1176                }
1177        }
1178
1179        /*
1180         * No single parent took the blame.  We add the candidates
1181         * from the above loop to the parents.
1182         */
1183        for (i = 0; i < nparents; i++) {
1184                add_line_range(rev, parents[i], cand[i]);
1185        }
1186
1187        clear_commit_line_range(rev, commit);
1188        free(parents);
1189        free(cand);
1190        free_diffqueues(nparents, diffqueues);
1191        return 1;
1192
1193        /* NEEDSWORK evil merge detection stuff */
1194        /* NEEDSWORK leaking like a sieve */
1195}
1196
1197static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1198{
1199        struct line_log_data *range = lookup_line_range(rev, commit);
1200        int changed = 0;
1201
1202        if (range) {
1203                if (!commit->parents || !commit->parents->next)
1204                        changed = process_ranges_ordinary_commit(rev, commit, range);
1205                else
1206                        changed = process_ranges_merge_commit(rev, commit, range);
1207        }
1208
1209        if (!changed)
1210                commit->object.flags |= TREESAME;
1211
1212        return changed;
1213}
1214
1215static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1216{
1217        for (;;) {
1218                struct commit *p = *pp;
1219                if (p->parents && p->parents->next)
1220                        return rewrite_one_ok;
1221                if (p->object.flags & UNINTERESTING)
1222                        return rewrite_one_ok;
1223                if (!(p->object.flags & TREESAME))
1224                        return rewrite_one_ok;
1225                if (!p->parents)
1226                        return rewrite_one_noparents;
1227                *pp = p->parents->item;
1228        }
1229}
1230
1231int line_log_filter(struct rev_info *rev)
1232{
1233        struct commit *commit;
1234        struct commit_list *list = rev->commits;
1235        struct commit_list *out = NULL, **pp = &out;
1236
1237        while (list) {
1238                struct commit_list *to_free = NULL;
1239                commit = list->item;
1240                if (process_ranges_arbitrary_commit(rev, commit)) {
1241                        *pp = list;
1242                        pp = &list->next;
1243                } else
1244                        to_free = list;
1245                list = list->next;
1246                free(to_free);
1247        }
1248        *pp = NULL;
1249
1250        for (list = out; list; list = list->next)
1251                rewrite_parents(rev, list->item, line_log_rewrite_one);
1252
1253        rev->commits = out;
1254
1255        return 0;
1256}