line-log.con commit Merge branch 'bw/protocol-v2' into jt/partial-clone-proto-v2 (ea44c0a)
   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(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 diff_filespec *spec, long *lines,
 512                           unsigned long **line_ends)
 513{
 514        int num = 0, size = 50;
 515        long cur = 0;
 516        unsigned long *ends = NULL;
 517        char *data = NULL;
 518
 519        if (diff_populate_filespec(spec, 0))
 520                die("Cannot read blob %s", oid_to_hex(&spec->oid));
 521
 522        ALLOC_ARRAY(ends, size);
 523        ends[cur++] = 0;
 524        data = spec->data;
 525        while (num < spec->size) {
 526                if (data[num] == '\n' || num == spec->size - 1) {
 527                        ALLOC_GROW(ends, (cur + 1), size);
 528                        ends[cur++] = num;
 529                }
 530                num++;
 531        }
 532
 533        /* shrink the array to fit the elements */
 534        REALLOC_ARRAY(ends, cur);
 535        *lines = cur-1;
 536        *line_ends = ends;
 537}
 538
 539struct nth_line_cb {
 540        struct diff_filespec *spec;
 541        long lines;
 542        unsigned long *line_ends;
 543};
 544
 545static const char *nth_line(void *data, long line)
 546{
 547        struct nth_line_cb *d = data;
 548        assert(d && line <= d->lines);
 549        assert(d->spec && d->spec->data);
 550
 551        if (line == 0)
 552                return (char *)d->spec->data;
 553        else
 554                return (char *)d->spec->data + d->line_ends[line] + 1;
 555}
 556
 557static struct line_log_data *
 558parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 559{
 560        long lines = 0;
 561        unsigned long *ends = NULL;
 562        struct nth_line_cb cb_data;
 563        struct string_list_item *item;
 564        struct line_log_data *ranges = NULL;
 565        struct line_log_data *p;
 566
 567        for_each_string_list_item(item, args) {
 568                const char *name_part, *range_part;
 569                char *full_name;
 570                struct diff_filespec *spec;
 571                long begin = 0, end = 0;
 572                long anchor;
 573
 574                name_part = skip_range_arg(item->string);
 575                if (!name_part || *name_part != ':' || !name_part[1])
 576                        die("-L argument not 'start,end:file' or ':funcname:file': %s",
 577                            item->string);
 578                range_part = xstrndup(item->string, name_part - item->string);
 579                name_part++;
 580
 581                full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 582                                        name_part);
 583
 584                spec = alloc_filespec(full_name);
 585                fill_blob_sha1(commit, spec);
 586                fill_line_ends(spec, &lines, &ends);
 587                cb_data.spec = spec;
 588                cb_data.lines = lines;
 589                cb_data.line_ends = ends;
 590
 591                p = search_line_log_data(ranges, full_name, NULL);
 592                if (p && p->ranges.nr)
 593                        anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 594                else
 595                        anchor = 1;
 596
 597                if (parse_range_arg(range_part, nth_line, &cb_data,
 598                                    lines, anchor, &begin, &end,
 599                                    full_name))
 600                        die("malformed -L argument '%s'", range_part);
 601                if (lines < end || ((lines || begin) && lines < begin))
 602                        die("file %s has only %lu lines", name_part, lines);
 603                if (begin < 1)
 604                        begin = 1;
 605                if (end < 1)
 606                        end = lines;
 607                begin--;
 608                line_log_data_insert(&ranges, full_name, begin, end);
 609
 610                free_filespec(spec);
 611                FREE_AND_NULL(ends);
 612        }
 613
 614        for (p = ranges; p; p = p->next)
 615                sort_and_merge_range_set(&p->ranges);
 616
 617        return ranges;
 618}
 619
 620static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 621{
 622        struct line_log_data *ret = xmalloc(sizeof(*ret));
 623
 624        assert(r);
 625        line_log_data_init(ret);
 626        range_set_copy(&ret->ranges, &r->ranges);
 627
 628        ret->path = xstrdup(r->path);
 629
 630        return ret;
 631}
 632
 633static struct line_log_data *
 634line_log_data_copy(struct line_log_data *r)
 635{
 636        struct line_log_data *ret = NULL;
 637        struct line_log_data *tmp = NULL, *prev = NULL;
 638
 639        assert(r);
 640        ret = tmp = prev = line_log_data_copy_one(r);
 641        r = r->next;
 642        while (r) {
 643                tmp = line_log_data_copy_one(r);
 644                prev->next = tmp;
 645                prev = tmp;
 646                r = r->next;
 647        }
 648
 649        return ret;
 650}
 651
 652/* merge two range sets across files */
 653static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 654                                                 struct line_log_data *b)
 655{
 656        struct line_log_data *head = NULL, **pp = &head;
 657
 658        while (a || b) {
 659                struct line_log_data *src;
 660                struct line_log_data *src2 = NULL;
 661                struct line_log_data *d;
 662                int cmp;
 663                if (!a)
 664                        cmp = 1;
 665                else if (!b)
 666                        cmp = -1;
 667                else
 668                        cmp = strcmp(a->path, b->path);
 669                if (cmp < 0) {
 670                        src = a;
 671                        a = a->next;
 672                } else if (cmp == 0) {
 673                        src = a;
 674                        a = a->next;
 675                        src2 = b;
 676                        b = b->next;
 677                } else {
 678                        src = b;
 679                        b = b->next;
 680                }
 681                d = xmalloc(sizeof(struct line_log_data));
 682                line_log_data_init(d);
 683                d->path = xstrdup(src->path);
 684                *pp = d;
 685                pp = &d->next;
 686                if (src2)
 687                        range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 688                else
 689                        range_set_copy(&d->ranges, &src->ranges);
 690        }
 691
 692        return head;
 693}
 694
 695static void add_line_range(struct rev_info *revs, struct commit *commit,
 696                           struct line_log_data *range)
 697{
 698        struct line_log_data *old_line = NULL;
 699        struct line_log_data *new_line = NULL;
 700
 701        old_line = lookup_decoration(&revs->line_log_data, &commit->object);
 702        if (old_line && range) {
 703                new_line = line_log_data_merge(old_line, range);
 704                free_line_log_data(old_line);
 705        } else if (range)
 706                new_line = line_log_data_copy(range);
 707
 708        if (new_line)
 709                add_decoration(&revs->line_log_data, &commit->object, new_line);
 710}
 711
 712static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 713{
 714        struct line_log_data *r;
 715        r = lookup_decoration(&revs->line_log_data, &commit->object);
 716        if (!r)
 717                return;
 718        free_line_log_data(r);
 719        add_decoration(&revs->line_log_data, &commit->object, NULL);
 720}
 721
 722static struct line_log_data *lookup_line_range(struct rev_info *revs,
 723                                               struct commit *commit)
 724{
 725        struct line_log_data *ret = NULL;
 726        struct line_log_data *d;
 727
 728        ret = lookup_decoration(&revs->line_log_data, &commit->object);
 729
 730        for (d = ret; d; d = d->next)
 731                range_set_check_invariants(&d->ranges);
 732
 733        return ret;
 734}
 735
 736void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 737{
 738        struct commit *commit = NULL;
 739        struct line_log_data *range;
 740
 741        commit = check_single_commit(rev);
 742        range = parse_lines(commit, prefix, args);
 743        add_line_range(rev, commit, range);
 744
 745        if (!rev->diffopt.detect_rename) {
 746                struct line_log_data *r;
 747                struct argv_array array = ARGV_ARRAY_INIT;
 748                const char **paths;
 749
 750                for (r = range; r; r = r->next)
 751                        argv_array_push(&array, r->path);
 752                paths = argv_array_detach(&array);
 753
 754                parse_pathspec(&rev->diffopt.pathspec, 0,
 755                               PATHSPEC_PREFER_FULL, "", paths);
 756                /* strings are now owned by pathspec */
 757                free(paths);
 758        }
 759}
 760
 761static void move_diff_queue(struct diff_queue_struct *dst,
 762                            struct diff_queue_struct *src)
 763{
 764        assert(src != dst);
 765        memcpy(dst, src, sizeof(struct diff_queue_struct));
 766        DIFF_QUEUE_CLEAR(src);
 767}
 768
 769static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 770{
 771        int i;
 772        struct diff_queue_struct outq;
 773        DIFF_QUEUE_CLEAR(&outq);
 774
 775        for (i = 0; i < diff_queued_diff.nr; i++) {
 776                struct diff_filepair *p = diff_queued_diff.queue[i];
 777                struct line_log_data *rg = NULL;
 778
 779                if (!DIFF_FILE_VALID(p->two)) {
 780                        if (keep_deletions)
 781                                diff_q(&outq, p);
 782                        else
 783                                diff_free_filepair(p);
 784                        continue;
 785                }
 786                for (rg = range; rg; rg = rg->next) {
 787                        if (!strcmp(rg->path, p->two->path))
 788                                break;
 789                }
 790                if (rg)
 791                        diff_q(&outq, p);
 792                else
 793                        diff_free_filepair(p);
 794        }
 795        free(diff_queued_diff.queue);
 796        diff_queued_diff = outq;
 797}
 798
 799static inline int diff_might_be_rename(void)
 800{
 801        int i;
 802        for (i = 0; i < diff_queued_diff.nr; i++)
 803                if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 804                        /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 805                        /*      diff_queued_diff.queue[i]->two->path); */
 806                        return 1;
 807                }
 808        return 0;
 809}
 810
 811static void queue_diffs(struct line_log_data *range,
 812                        struct diff_options *opt,
 813                        struct diff_queue_struct *queue,
 814                        struct commit *commit, struct commit *parent)
 815{
 816        assert(commit);
 817
 818        DIFF_QUEUE_CLEAR(&diff_queued_diff);
 819        diff_tree_oid(parent ? &parent->tree->object.oid : NULL,
 820                      &commit->tree->object.oid, "", opt);
 821        if (opt->detect_rename) {
 822                filter_diffs_for_paths(range, 1);
 823                if (diff_might_be_rename())
 824                        diffcore_std(opt);
 825                filter_diffs_for_paths(range, 0);
 826        }
 827        move_diff_queue(queue, &diff_queued_diff);
 828}
 829
 830static char *get_nth_line(long line, unsigned long *ends, void *data)
 831{
 832        if (line == 0)
 833                return (char *)data;
 834        else
 835                return (char *)data + ends[line] + 1;
 836}
 837
 838static void print_line(const char *prefix, char first,
 839                       long line, unsigned long *ends, void *data,
 840                       const char *color, const char *reset, FILE *file)
 841{
 842        char *begin = get_nth_line(line, ends, data);
 843        char *end = get_nth_line(line+1, ends, data);
 844        int had_nl = 0;
 845
 846        if (end > begin && end[-1] == '\n') {
 847                end--;
 848                had_nl = 1;
 849        }
 850
 851        fputs(prefix, file);
 852        fputs(color, file);
 853        putc(first, file);
 854        fwrite(begin, 1, end-begin, file);
 855        fputs(reset, file);
 856        putc('\n', file);
 857        if (!had_nl)
 858                fputs("\\ No newline at end of file\n", file);
 859}
 860
 861static char *output_prefix(struct diff_options *opt)
 862{
 863        char *prefix = "";
 864
 865        if (opt->output_prefix) {
 866                struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 867                prefix = sb->buf;
 868        }
 869
 870        return prefix;
 871}
 872
 873static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 874{
 875        unsigned int i, j = 0;
 876        long p_lines, t_lines;
 877        unsigned long *p_ends = NULL, *t_ends = NULL;
 878        struct diff_filepair *pair = range->pair;
 879        struct diff_ranges *diff = &range->diff;
 880
 881        struct diff_options *opt = &rev->diffopt;
 882        char *prefix = output_prefix(opt);
 883        const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 884        const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 885        const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 886        const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 887        const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 888        const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 889
 890        if (!pair || !diff)
 891                return;
 892
 893        if (pair->one->oid_valid)
 894                fill_line_ends(pair->one, &p_lines, &p_ends);
 895        fill_line_ends(pair->two, &t_lines, &t_ends);
 896
 897        fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 898        fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 899               pair->one->oid_valid ? "a/" : "",
 900               pair->one->oid_valid ? pair->one->path : "/dev/null",
 901               c_reset);
 902        fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 903        for (i = 0; i < range->ranges.nr; i++) {
 904                long p_start, p_end;
 905                long t_start = range->ranges.ranges[i].start;
 906                long t_end = range->ranges.ranges[i].end;
 907                long t_cur = t_start;
 908                unsigned int j_last;
 909
 910                while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 911                        j++;
 912                if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 913                        continue;
 914
 915                /* Scan ahead to determine the last diff that falls in this range */
 916                j_last = j;
 917                while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 918                        j_last++;
 919                if (j_last > j)
 920                        j_last--;
 921
 922                /*
 923                 * Compute parent hunk headers: we know that the diff
 924                 * has the correct line numbers (but not all hunks).
 925                 * So it suffices to shift the start/end according to
 926                 * the line numbers of the first/last hunk(s) that
 927                 * fall in this range.
 928                 */
 929                if (t_start < diff->target.ranges[j].start)
 930                        p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 931                else
 932                        p_start = diff->parent.ranges[j].start;
 933                if (t_end > diff->target.ranges[j_last].end)
 934                        p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 935                else
 936                        p_end = diff->parent.ranges[j_last].end;
 937
 938                if (!p_start && !p_end) {
 939                        p_start = -1;
 940                        p_end = -1;
 941                }
 942
 943                /* Now output a diff hunk for this range */
 944                fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 945                       prefix, c_frag,
 946                       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 947                       c_reset);
 948                while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 949                        int k;
 950                        for (; t_cur < diff->target.ranges[j].start; t_cur++)
 951                                print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 952                                           c_context, c_reset, opt->file);
 953                        for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 954                                print_line(prefix, '-', k, p_ends, pair->one->data,
 955                                           c_old, c_reset, opt->file);
 956                        for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 957                                print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 958                                           c_new, c_reset, opt->file);
 959                        j++;
 960                }
 961                for (; t_cur < t_end; t_cur++)
 962                        print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 963                                   c_context, c_reset, opt->file);
 964        }
 965
 966        free(p_ends);
 967        free(t_ends);
 968}
 969
 970/*
 971 * NEEDSWORK: manually building a diff here is not the Right
 972 * Thing(tm).  log -L should be built into the diff pipeline.
 973 */
 974static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 975{
 976        fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
 977        while (range) {
 978                dump_diff_hacky_one(rev, range);
 979                range = range->next;
 980        }
 981}
 982
 983/*
 984 * Unlike most other functions, this destructively operates on
 985 * 'range'.
 986 */
 987static int process_diff_filepair(struct rev_info *rev,
 988                                 struct diff_filepair *pair,
 989                                 struct line_log_data *range,
 990                                 struct diff_ranges **diff_out)
 991{
 992        struct line_log_data *rg = range;
 993        struct range_set tmp;
 994        struct diff_ranges diff;
 995        mmfile_t file_parent, file_target;
 996
 997        assert(pair->two->path);
 998        while (rg) {
 999                assert(rg->path);
1000                if (!strcmp(rg->path, pair->two->path))
1001                        break;
1002                rg = rg->next;
1003        }
1004
1005        if (!rg)
1006                return 0;
1007        if (rg->ranges.nr == 0)
1008                return 0;
1009
1010        assert(pair->two->oid_valid);
1011        diff_populate_filespec(pair->two, 0);
1012        file_target.ptr = pair->two->data;
1013        file_target.size = pair->two->size;
1014
1015        if (pair->one->oid_valid) {
1016                diff_populate_filespec(pair->one, 0);
1017                file_parent.ptr = pair->one->data;
1018                file_parent.size = pair->one->size;
1019        } else {
1020                file_parent.ptr = "";
1021                file_parent.size = 0;
1022        }
1023
1024        diff_ranges_init(&diff);
1025        if (collect_diff(&file_parent, &file_target, &diff))
1026                die("unable to generate diff for %s", pair->one->path);
1027
1028        /* NEEDSWORK should apply some heuristics to prevent mismatches */
1029        free(rg->path);
1030        rg->path = xstrdup(pair->one->path);
1031
1032        range_set_init(&tmp, 0);
1033        range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1034        range_set_release(&rg->ranges);
1035        range_set_move(&rg->ranges, &tmp);
1036
1037        diff_ranges_release(&diff);
1038
1039        return ((*diff_out)->parent.nr > 0);
1040}
1041
1042static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1043{
1044        struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
1045        new_filepair->one = pair->one;
1046        new_filepair->two = pair->two;
1047        new_filepair->one->count++;
1048        new_filepair->two->count++;
1049        return new_filepair;
1050}
1051
1052static void free_diffqueues(int n, struct diff_queue_struct *dq)
1053{
1054        int i, j;
1055        for (i = 0; i < n; i++)
1056                for (j = 0; j < dq[i].nr; j++)
1057                        diff_free_filepair(dq[i].queue[j]);
1058        free(dq);
1059}
1060
1061static int process_all_files(struct line_log_data **range_out,
1062                             struct rev_info *rev,
1063                             struct diff_queue_struct *queue,
1064                             struct line_log_data *range)
1065{
1066        int i, changed = 0;
1067
1068        *range_out = line_log_data_copy(range);
1069
1070        for (i = 0; i < queue->nr; i++) {
1071                struct diff_ranges *pairdiff = NULL;
1072                struct diff_filepair *pair = queue->queue[i];
1073                if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1074                        /*
1075                         * Store away the diff for later output.  We
1076                         * tuck it in the ranges we got as _input_,
1077                         * since that's the commit that caused the
1078                         * diff.
1079                         *
1080                         * NEEDSWORK not enough when we get around to
1081                         * doing something interesting with merges;
1082                         * currently each invocation on a merge parent
1083                         * trashes the previous one's diff.
1084                         *
1085                         * NEEDSWORK tramples over data structures not owned here
1086                         */
1087                        struct line_log_data *rg = range;
1088                        changed++;
1089                        while (rg && strcmp(rg->path, pair->two->path))
1090                                rg = rg->next;
1091                        assert(rg);
1092                        rg->pair = diff_filepair_dup(queue->queue[i]);
1093                        memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1094                }
1095                free(pairdiff);
1096        }
1097
1098        return changed;
1099}
1100
1101int line_log_print(struct rev_info *rev, struct commit *commit)
1102{
1103        struct line_log_data *range = lookup_line_range(rev, commit);
1104
1105        show_log(rev);
1106        dump_diff_hacky(rev, range);
1107        return 1;
1108}
1109
1110static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1111                                          struct line_log_data *range)
1112{
1113        struct commit *parent = NULL;
1114        struct diff_queue_struct queue;
1115        struct line_log_data *parent_range;
1116        int changed;
1117
1118        if (commit->parents)
1119                parent = commit->parents->item;
1120
1121        queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1122        changed = process_all_files(&parent_range, rev, &queue, range);
1123        if (parent)
1124                add_line_range(rev, parent, parent_range);
1125        free_line_log_data(parent_range);
1126        return changed;
1127}
1128
1129static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1130                                       struct line_log_data *range)
1131{
1132        struct diff_queue_struct *diffqueues;
1133        struct line_log_data **cand;
1134        struct commit **parents;
1135        struct commit_list *p;
1136        int i;
1137        int nparents = commit_list_count(commit->parents);
1138
1139        if (nparents > 1 && rev->first_parent_only)
1140                nparents = 1;
1141
1142        ALLOC_ARRAY(diffqueues, nparents);
1143        ALLOC_ARRAY(cand, nparents);
1144        ALLOC_ARRAY(parents, nparents);
1145
1146        p = commit->parents;
1147        for (i = 0; i < nparents; i++) {
1148                parents[i] = p->item;
1149                p = p->next;
1150                queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1151        }
1152
1153        for (i = 0; i < nparents; i++) {
1154                int changed;
1155                cand[i] = NULL;
1156                changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1157                if (!changed) {
1158                        /*
1159                         * This parent can take all the blame, so we
1160                         * don't follow any other path in history
1161                         */
1162                        add_line_range(rev, parents[i], cand[i]);
1163                        clear_commit_line_range(rev, commit);
1164                        commit_list_append(parents[i], &commit->parents);
1165                        free(parents);
1166                        free(cand);
1167                        free_diffqueues(nparents, diffqueues);
1168                        /* NEEDSWORK leaking like a sieve */
1169                        return 0;
1170                }
1171        }
1172
1173        /*
1174         * No single parent took the blame.  We add the candidates
1175         * from the above loop to the parents.
1176         */
1177        for (i = 0; i < nparents; i++) {
1178                add_line_range(rev, parents[i], cand[i]);
1179        }
1180
1181        clear_commit_line_range(rev, commit);
1182        free(parents);
1183        free(cand);
1184        free_diffqueues(nparents, diffqueues);
1185        return 1;
1186
1187        /* NEEDSWORK evil merge detection stuff */
1188        /* NEEDSWORK leaking like a sieve */
1189}
1190
1191static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1192{
1193        struct line_log_data *range = lookup_line_range(rev, commit);
1194        int changed = 0;
1195
1196        if (range) {
1197                if (!commit->parents || !commit->parents->next)
1198                        changed = process_ranges_ordinary_commit(rev, commit, range);
1199                else
1200                        changed = process_ranges_merge_commit(rev, commit, range);
1201        }
1202
1203        if (!changed)
1204                commit->object.flags |= TREESAME;
1205
1206        return changed;
1207}
1208
1209static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1210{
1211        for (;;) {
1212                struct commit *p = *pp;
1213                if (p->parents && p->parents->next)
1214                        return rewrite_one_ok;
1215                if (p->object.flags & UNINTERESTING)
1216                        return rewrite_one_ok;
1217                if (!(p->object.flags & TREESAME))
1218                        return rewrite_one_ok;
1219                if (!p->parents)
1220                        return rewrite_one_noparents;
1221                *pp = p->parents->item;
1222        }
1223}
1224
1225int line_log_filter(struct rev_info *rev)
1226{
1227        struct commit *commit;
1228        struct commit_list *list = rev->commits;
1229        struct commit_list *out = NULL, **pp = &out;
1230
1231        while (list) {
1232                struct commit_list *to_free = NULL;
1233                commit = list->item;
1234                if (process_ranges_arbitrary_commit(rev, commit)) {
1235                        *pp = list;
1236                        pp = &list->next;
1237                } else
1238                        to_free = list;
1239                list = list->next;
1240                free(to_free);
1241        }
1242        *pp = NULL;
1243
1244        for (list = out; list; list = list->next)
1245                rewrite_parents(rev, list->item, line_log_rewrite_one);
1246
1247        rev->commits = out;
1248
1249        return 0;
1250}