git.oblomov.eu Git - git/blob - line-log.c

   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 #include "bloom.h"
  19
  20 static void range_set_grow(struct range_set *rs, size_t extra)
  21 {
  22         ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
  23 }
  24
  25 /* Either initialization would be fine */
  26 #define RANGE_SET_INIT {0}
  27
  28 void range_set_init(struct range_set *rs, size_t prealloc)
  29 {
  30         rs->alloc = rs->nr = 0;
  31         rs->ranges = NULL;
  32         if (prealloc)
  33                 range_set_grow(rs, prealloc);
  34 }
  35
  36 void range_set_release(struct range_set *rs)
  37 {
  38         FREE_AND_NULL(rs->ranges);
  39         rs->alloc = rs->nr = 0;
  40 }
  41
  42 /* dst must be uninitialized! */
  43 static void range_set_copy(struct range_set *dst, struct range_set *src)
  44 {
  45         range_set_init(dst, src->nr);
  46         COPY_ARRAY(dst->ranges, src->ranges, src->nr);
  47         dst->nr = src->nr;
  48 }
  49
  50 static void range_set_move(struct range_set *dst, struct range_set *src)
  51 {
  52         range_set_release(dst);
  53         dst->ranges = src->ranges;
  54         dst->nr = src->nr;
  55         dst->alloc = src->alloc;
  56         src->ranges = NULL;
  57         src->alloc = src->nr = 0;
  58 }
  59
  60 /* tack on a _new_ range _at the end_ */
  61 void range_set_append_unsafe(struct range_set *rs, long a, long b)
  62 {
  63         assert(a <= b);
  64         range_set_grow(rs, 1);
  65         rs->ranges[rs->nr].start = a;
  66         rs->ranges[rs->nr].end = b;
  67         rs->nr++;
  68 }
  69
  70 void range_set_append(struct range_set *rs, long a, long b)
  71 {
  72         assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
  73         range_set_append_unsafe(rs, a, b);
  74 }
  75
  76 static int range_cmp(const void *_r, const void *_s)
  77 {
  78         const struct range *r = _r;
  79         const struct range *s = _s;
  80
  81         /* this could be simply 'return r.start-s.start', but for the types */
  82         if (r->start == s->start)
  83                 return 0;
  84         if (r->start < s->start)
  85                 return -1;
  86         return 1;
  87 }
  88
  89 /*
  90  * Check that the ranges are non-empty, sorted and non-overlapping
  91  */
  92 static void range_set_check_invariants(struct range_set *rs)
  93 {
  94         unsigned int i;
  95
  96         if (!rs)
  97                 return;
  98
  99         if (rs->nr)
 100                 assert(rs->ranges[0].start < rs->ranges[0].end);
 101
 102         for (i = 1; i < rs->nr; i++) {
 103                 assert(rs->ranges[i-1].end < rs->ranges[i].start);
 104                 assert(rs->ranges[i].start < rs->ranges[i].end);
 105         }
 106 }
 107
 108 /*
 109  * In-place pass of sorting and merging the ranges in the range set,
 110  * to establish the invariants when we get the ranges from the user
 111  */
 112 void sort_and_merge_range_set(struct range_set *rs)
 113 {
 114         unsigned int i;
 115         unsigned int o = 0; /* output cursor */
 116
 117         QSORT(rs->ranges, rs->nr, range_cmp);
 118
 119         for (i = 0; i < rs->nr; i++) {
 120                 if (rs->ranges[i].start == rs->ranges[i].end)
 121                         continue;
 122                 if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
 123                         if (rs->ranges[o-1].end < rs->ranges[i].end)
 124                                 rs->ranges[o-1].end = rs->ranges[i].end;
 125                 } else {
 126                         rs->ranges[o].start = rs->ranges[i].start;
 127                         rs->ranges[o].end = rs->ranges[i].end;
 128                         o++;
 129                 }
 130         }
 131         assert(o <= rs->nr);
 132         rs->nr = o;
 133
 134         range_set_check_invariants(rs);
 135 }
 136
 137 /*
 138  * Union of range sets (i.e., sets of line numbers).  Used to merge
 139  * them when searches meet at a common ancestor.
 140  *
 141  * This is also where the ranges are consolidated into canonical form:
 142  * overlapping and adjacent ranges are merged, and empty ranges are
 143  * removed.
 144  */
 145 static void range_set_union(struct range_set *out,
 146                              struct range_set *a, struct range_set *b)
 147 {
 148         unsigned int i = 0, j = 0;
 149         struct range *ra = a->ranges;
 150         struct range *rb = b->ranges;
 151         /* cannot make an alias of out->ranges: it may change during grow */
 152
 153         assert(out->nr == 0);
 154         while (i < a->nr || j < b->nr) {
 155                 struct range *new_range;
 156                 if (i < a->nr && j < b->nr) {
 157                         if (ra[i].start < rb[j].start)
 158                                 new_range = &ra[i++];
 159                         else if (ra[i].start > rb[j].start)
 160                                 new_range = &rb[j++];
 161                         else if (ra[i].end < rb[j].end)
 162                                 new_range = &ra[i++];
 163                         else
 164                                 new_range = &rb[j++];
 165                 } else if (i < a->nr)      /* b exhausted */
 166                         new_range = &ra[i++];
 167                 else                       /* a exhausted */
 168                         new_range = &rb[j++];
 169                 if (new_range->start == new_range->end)
 170                         ; /* empty range */
 171                 else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
 172                         range_set_grow(out, 1);
 173                         out->ranges[out->nr].start = new_range->start;
 174                         out->ranges[out->nr].end = new_range->end;
 175                         out->nr++;
 176                 } else if (out->ranges[out->nr-1].end < new_range->end) {
 177                         out->ranges[out->nr-1].end = new_range->end;
 178                 }
 179         }
 180 }
 181
 182 /*
 183  * Difference of range sets (out = a \ b).  Pass the "interesting"
 184  * ranges as 'a' and the target side of the diff as 'b': it removes
 185  * the ranges for which the commit is responsible.
 186  */
 187 static void range_set_difference(struct range_set *out,
 188                                   struct range_set *a, struct range_set *b)
 189 {
 190         unsigned int i, j =  0;
 191         for (i = 0; i < a->nr; i++) {
 192                 long start = a->ranges[i].start;
 193                 long end = a->ranges[i].end;
 194                 while (start < end) {
 195                         while (j < b->nr && start >= b->ranges[j].end)
 196                                 /*
 197                                  * a:         |-------
 198                                  * b: ------|
 199                                  */
 200                                 j++;
 201                         if (j >= b->nr || end < b->ranges[j].start) {
 202                                 /*
 203                                  * b exhausted, or
 204                                  * a:  ----|
 205                                  * b:         |----
 206                                  */
 207                                 range_set_append(out, start, end);
 208                                 break;
 209                         }
 210                         if (start >= b->ranges[j].start) {
 211                                 /*
 212                                  * a:     |--????
 213                                  * b: |------|
 214                                  */
 215                                 start = b->ranges[j].end;
 216                         } else if (end > b->ranges[j].start) {
 217                                 /*
 218                                  * a: |-----|
 219                                  * b:    |--?????
 220                                  */
 221                                 if (start < b->ranges[j].start)
 222                                         range_set_append(out, start, b->ranges[j].start);
 223                                 start = b->ranges[j].end;
 224                         }
 225                 }
 226         }
 227 }
 228
 229 static void diff_ranges_init(struct diff_ranges *diff)
 230 {
 231         range_set_init(&diff->parent, 0);
 232         range_set_init(&diff->target, 0);
 233 }
 234
 235 static void diff_ranges_release(struct diff_ranges *diff)
 236 {
 237         range_set_release(&diff->parent);
 238         range_set_release(&diff->target);
 239 }
 240
 241 static void line_log_data_init(struct line_log_data *r)
 242 {
 243         memset(r, 0, sizeof(struct line_log_data));
 244         range_set_init(&r->ranges, 0);
 245 }
 246
 247 static void line_log_data_clear(struct line_log_data *r)
 248 {
 249         range_set_release(&r->ranges);
 250         if (r->pair)
 251                 diff_free_filepair(r->pair);
 252 }
 253
 254 static void free_line_log_data(struct line_log_data *r)
 255 {
 256         while (r) {
 257                 struct line_log_data *next = r->next;
 258                 line_log_data_clear(r);
 259                 free(r);
 260                 r = next;
 261         }
 262 }
 263
 264 static struct line_log_data *
 265 search_line_log_data(struct line_log_data *list, const char *path,
 266                      struct line_log_data **insertion_point)
 267 {
 268         struct line_log_data *p = list;
 269         if (insertion_point)
 270                 *insertion_point = NULL;
 271         while (p) {
 272                 int cmp = strcmp(p->path, path);
 273                 if (!cmp)
 274                         return p;
 275                 if (insertion_point && cmp < 0)
 276                         *insertion_point = p;
 277                 p = p->next;
 278         }
 279         return NULL;
 280 }
 281
 282 /*
 283  * Note: takes ownership of 'path', which happens to be what the only
 284  * caller needs.
 285  */
 286 static void line_log_data_insert(struct line_log_data **list,
 287                                  char *path,
 288                                  long begin, long end)
 289 {
 290         struct line_log_data *ip;
 291         struct line_log_data *p = search_line_log_data(*list, path, &ip);
 292
 293         if (p) {
 294                 range_set_append_unsafe(&p->ranges, begin, end);
 295                 free(path);
 296                 return;
 297         }
 298
 299         p = xcalloc(1, sizeof(struct line_log_data));
 300         p->path = path;
 301         range_set_append(&p->ranges, begin, end);
 302         if (ip) {
 303                 p->next = ip->next;
 304                 ip->next = p;
 305         } else {
 306                 p->next = *list;
 307                 *list = p;
 308         }
 309 }
 310
 311 struct collect_diff_cbdata {
 312         struct diff_ranges *diff;
 313 };
 314
 315 static int collect_diff_cb(long start_a, long count_a,
 316                            long start_b, long count_b,
 317                            void *data)
 318 {
 319         struct collect_diff_cbdata *d = data;
 320
 321         if (count_a >= 0)
 322                 range_set_append(&d->diff->parent, start_a, start_a + count_a);
 323         if (count_b >= 0)
 324                 range_set_append(&d->diff->target, start_b, start_b + count_b);
 325
 326         return 0;
 327 }
 328
 329 static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
 330 {
 331         struct collect_diff_cbdata cbdata = {NULL};
 332         xpparam_t xpp;
 333         xdemitconf_t xecfg;
 334         xdemitcb_t ecb;
 335
 336         memset(&xpp, 0, sizeof(xpp));
 337         memset(&xecfg, 0, sizeof(xecfg));
 338         xecfg.ctxlen = xecfg.interhunkctxlen = 0;
 339
 340         cbdata.diff = out;
 341         xecfg.hunk_func = collect_diff_cb;
 342         memset(&ecb, 0, sizeof(ecb));
 343         ecb.priv = &cbdata;
 344         return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
 345 }
 346
 347 /*
 348  * These are handy for debugging.  Removing them with #if 0 silences
 349  * the "unused function" warning.
 350  */
 351 #if 0
 352 static void dump_range_set(struct range_set *rs, const char *desc)
 353 {
 354         int i;
 355         printf("range set %s (%d items):\n", desc, rs->nr);
 356         for (i = 0; i < rs->nr; i++)
 357                 printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
 358 }
 359
 360 static void dump_line_log_data(struct line_log_data *r)
 361 {
 362         char buf[4096];
 363         while (r) {
 364                 snprintf(buf, 4096, "file %s\n", r->path);
 365                 dump_range_set(&r->ranges, buf);
 366                 r = r->next;
 367         }
 368 }
 369
 370 static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
 371 {
 372         int i;
 373         assert(diff->parent.nr == diff->target.nr);
 374         printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
 375         printf("\tparent\ttarget\n");
 376         for (i = 0; i < diff->parent.nr; i++) {
 377                 printf("\t[%ld,%ld]\t[%ld,%ld]\n",
 378                        diff->parent.ranges[i].start,
 379                        diff->parent.ranges[i].end,
 380                        diff->target.ranges[i].start,
 381                        diff->target.ranges[i].end);
 382         }
 383 }
 384 #endif
 385
 386
 387 static int ranges_overlap(struct range *a, struct range *b)
 388 {
 389         return !(a->end <= b->start || b->end <= a->start);
 390 }
 391
 392 /*
 393  * Given a diff and the set of interesting ranges, determine all hunks
 394  * of the diff which touch (overlap) at least one of the interesting
 395  * ranges in the target.
 396  */
 397 static void diff_ranges_filter_touched(struct diff_ranges *out,
 398                                        struct diff_ranges *diff,
 399                                        struct range_set *rs)
 400 {
 401         unsigned int i, j = 0;
 402
 403         assert(out->target.nr == 0);
 404
 405         for (i = 0; i < diff->target.nr; i++) {
 406                 while (diff->target.ranges[i].start > rs->ranges[j].end) {
 407                         j++;
 408                         if (j == rs->nr)
 409                                 return;
 410                 }
 411                 if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
 412                         range_set_append(&out->parent,
 413                                          diff->parent.ranges[i].start,
 414                                          diff->parent.ranges[i].end);
 415                         range_set_append(&out->target,
 416                                          diff->target.ranges[i].start,
 417                                          diff->target.ranges[i].end);
 418                 }
 419         }
 420 }
 421
 422 /*
 423  * Adjust the line counts in 'rs' to account for the lines
 424  * added/removed in the diff.
 425  */
 426 static void range_set_shift_diff(struct range_set *out,
 427                                  struct range_set *rs,
 428                                  struct diff_ranges *diff)
 429 {
 430         unsigned int i, j = 0;
 431         long offset = 0;
 432         struct range *src = rs->ranges;
 433         struct range *target = diff->target.ranges;
 434         struct range *parent = diff->parent.ranges;
 435
 436         for (i = 0; i < rs->nr; i++) {
 437                 while (j < diff->target.nr && src[i].start >= target[j].start) {
 438                         offset += (parent[j].end-parent[j].start)
 439                                 - (target[j].end-target[j].start);
 440                         j++;
 441                 }
 442                 range_set_append(out, src[i].start+offset, src[i].end+offset);
 443         }
 444 }
 445
 446 /*
 447  * Given a diff and the set of interesting ranges, map the ranges
 448  * across the diff.  That is: observe that the target commit takes
 449  * blame for all the + (target-side) ranges.  So for every pair of
 450  * ranges in the diff that was touched, we remove the latter and add
 451  * its parent side.
 452  */
 453 static void range_set_map_across_diff(struct range_set *out,
 454                                       struct range_set *rs,
 455                                       struct diff_ranges *diff,
 456                                       struct diff_ranges **touched_out)
 457 {
 458         struct diff_ranges *touched = xmalloc(sizeof(*touched));
 459         struct range_set tmp1 = RANGE_SET_INIT;
 460         struct range_set tmp2 = RANGE_SET_INIT;
 461
 462         diff_ranges_init(touched);
 463         diff_ranges_filter_touched(touched, diff, rs);
 464         range_set_difference(&tmp1, rs, &touched->target);
 465         range_set_shift_diff(&tmp2, &tmp1, diff);
 466         range_set_union(out, &tmp2, &touched->parent);
 467         range_set_release(&tmp1);
 468         range_set_release(&tmp2);
 469
 470         *touched_out = touched;
 471 }
 472
 473 static struct commit *check_single_commit(struct rev_info *revs)
 474 {
 475         struct object *commit = NULL;
 476         int found = -1;
 477         int i;
 478
 479         for (i = 0; i < revs->pending.nr; i++) {
 480                 struct object *obj = revs->pending.objects[i].item;
 481                 if (obj->flags & UNINTERESTING)
 482                         continue;
 483                 obj = deref_tag(revs->repo, 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
 500 static void fill_blob_sha1(struct repository *r, struct commit *commit,
 501                            struct diff_filespec *spec)
 502 {
 503         unsigned short mode;
 504         struct object_id oid;
 505
 506         if (get_tree_entry(r, &commit->object.oid, spec->path, &oid, &mode))
 507                 die("There is no path %s in the commit", spec->path);
 508         fill_filespec(spec, &oid, 1, mode);
 509
 510         return;
 511 }
 512
 513 static void fill_line_ends(struct repository *r,
 514                            struct diff_filespec *spec,
 515                            long *lines,
 516                            unsigned long **line_ends)
 517 {
 518         int num = 0, size = 50;
 519         long cur = 0;
 520         unsigned long *ends = NULL;
 521         char *data = NULL;
 522
 523         if (diff_populate_filespec(r, spec, NULL))
 524                 die("Cannot read blob %s", oid_to_hex(&spec->oid));
 525
 526         ALLOC_ARRAY(ends, size);
 527         ends[cur++] = 0;
 528         data = spec->data;
 529         while (num < spec->size) {
 530                 if (data[num] == '\n' || num == spec->size - 1) {
 531                         ALLOC_GROW(ends, (cur + 1), size);
 532                         ends[cur++] = num;
 533                 }
 534                 num++;
 535         }
 536
 537         /* shrink the array to fit the elements */
 538         REALLOC_ARRAY(ends, cur);
 539         *lines = cur-1;
 540         *line_ends = ends;
 541 }
 542
 543 struct nth_line_cb {
 544         struct diff_filespec *spec;
 545         long lines;
 546         unsigned long *line_ends;
 547 };
 548
 549 static const char *nth_line(void *data, long line)
 550 {
 551         struct nth_line_cb *d = data;
 552         assert(d && line <= d->lines);
 553         assert(d->spec && d->spec->data);
 554
 555         if (line == 0)
 556                 return (char *)d->spec->data;
 557         else
 558                 return (char *)d->spec->data + d->line_ends[line] + 1;
 559 }
 560
 561 static struct line_log_data *
 562 parse_lines(struct repository *r, struct commit *commit,
 563             const char *prefix, struct string_list *args)
 564 {
 565         long lines = 0;
 566         unsigned long *ends = NULL;
 567         struct nth_line_cb cb_data;
 568         struct string_list_item *item;
 569         struct line_log_data *ranges = NULL;
 570         struct line_log_data *p;
 571
 572         for_each_string_list_item(item, args) {
 573                 const char *name_part, *range_part;
 574                 char *full_name;
 575                 struct diff_filespec *spec;
 576                 long begin = 0, end = 0;
 577                 long anchor;
 578
 579                 name_part = skip_range_arg(item->string, r->index);
 580                 if (!name_part || *name_part != ':' || !name_part[1])
 581                         die("-L argument not 'start,end:file' or ':funcname:file': %s",
 582                             item->string);
 583                 range_part = xstrndup(item->string, name_part - item->string);
 584                 name_part++;
 585
 586                 full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 587                                         name_part);
 588
 589                 spec = alloc_filespec(full_name);
 590                 fill_blob_sha1(r, commit, spec);
 591                 fill_line_ends(r, spec, &lines, &ends);
 592                 cb_data.spec = spec;
 593                 cb_data.lines = lines;
 594                 cb_data.line_ends = ends;
 595
 596                 p = search_line_log_data(ranges, full_name, NULL);
 597                 if (p && p->ranges.nr)
 598                         anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 599                 else
 600                         anchor = 1;
 601
 602                 if (parse_range_arg(range_part, nth_line, &cb_data,
 603                                     lines, anchor, &begin, &end,
 604                                     full_name, r->index))
 605                         die("malformed -L argument '%s'", range_part);
 606                 if ((!lines && (begin || end)) || lines < begin)
 607                         die("file %s has only %lu lines", name_part, lines);
 608                 if (begin < 1)
 609                         begin = 1;
 610                 if (end < 1 || lines < end)
 611                         end = lines;
 612                 begin--;
 613                 line_log_data_insert(&ranges, full_name, begin, end);
 614
 615                 free_filespec(spec);
 616                 FREE_AND_NULL(ends);
 617         }
 618
 619         for (p = ranges; p; p = p->next)
 620                 sort_and_merge_range_set(&p->ranges);
 621
 622         return ranges;
 623 }
 624
 625 static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 626 {
 627         struct line_log_data *ret = xmalloc(sizeof(*ret));
 628
 629         assert(r);
 630         line_log_data_init(ret);
 631         range_set_copy(&ret->ranges, &r->ranges);
 632
 633         ret->path = xstrdup(r->path);
 634
 635         return ret;
 636 }
 637
 638 static struct line_log_data *
 639 line_log_data_copy(struct line_log_data *r)
 640 {
 641         struct line_log_data *ret = NULL;
 642         struct line_log_data *tmp = NULL, *prev = NULL;
 643
 644         assert(r);
 645         ret = tmp = prev = line_log_data_copy_one(r);
 646         r = r->next;
 647         while (r) {
 648                 tmp = line_log_data_copy_one(r);
 649                 prev->next = tmp;
 650                 prev = tmp;
 651                 r = r->next;
 652         }
 653
 654         return ret;
 655 }
 656
 657 /* merge two range sets across files */
 658 static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 659                                                  struct line_log_data *b)
 660 {
 661         struct line_log_data *head = NULL, **pp = &head;
 662
 663         while (a || b) {
 664                 struct line_log_data *src;
 665                 struct line_log_data *src2 = NULL;
 666                 struct line_log_data *d;
 667                 int cmp;
 668                 if (!a)
 669                         cmp = 1;
 670                 else if (!b)
 671                         cmp = -1;
 672                 else
 673                         cmp = strcmp(a->path, b->path);
 674                 if (cmp < 0) {
 675                         src = a;
 676                         a = a->next;
 677                 } else if (cmp == 0) {
 678                         src = a;
 679                         a = a->next;
 680                         src2 = b;
 681                         b = b->next;
 682                 } else {
 683                         src = b;
 684                         b = b->next;
 685                 }
 686                 d = xmalloc(sizeof(struct line_log_data));
 687                 line_log_data_init(d);
 688                 d->path = xstrdup(src->path);
 689                 *pp = d;
 690                 pp = &d->next;
 691                 if (src2)
 692                         range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 693                 else
 694                         range_set_copy(&d->ranges, &src->ranges);
 695         }
 696
 697         return head;
 698 }
 699
 700 static void add_line_range(struct rev_info *revs, struct commit *commit,
 701                            struct line_log_data *range)
 702 {
 703         struct line_log_data *old_line = NULL;
 704         struct line_log_data *new_line = NULL;
 705
 706         old_line = lookup_decoration(&revs->line_log_data, &commit->object);
 707         if (old_line && range) {
 708                 new_line = line_log_data_merge(old_line, range);
 709                 free_line_log_data(old_line);
 710         } else if (range)
 711                 new_line = line_log_data_copy(range);
 712
 713         if (new_line)
 714                 add_decoration(&revs->line_log_data, &commit->object, new_line);
 715 }
 716
 717 static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 718 {
 719         struct line_log_data *r;
 720         r = lookup_decoration(&revs->line_log_data, &commit->object);
 721         if (!r)
 722                 return;
 723         free_line_log_data(r);
 724         add_decoration(&revs->line_log_data, &commit->object, NULL);
 725 }
 726
 727 static struct line_log_data *lookup_line_range(struct rev_info *revs,
 728                                                struct commit *commit)
 729 {
 730         struct line_log_data *ret = NULL;
 731         struct line_log_data *d;
 732
 733         ret = lookup_decoration(&revs->line_log_data, &commit->object);
 734
 735         for (d = ret; d; d = d->next)
 736                 range_set_check_invariants(&d->ranges);
 737
 738         return ret;
 739 }
 740
 741 static int same_paths_in_pathspec_and_range(struct pathspec *pathspec,
 742                                             struct line_log_data *range)
 743 {
 744         int i;
 745         struct line_log_data *r;
 746
 747         for (i = 0, r = range; i < pathspec->nr && r; i++, r = r->next)
 748                 if (strcmp(pathspec->items[i].match, r->path))
 749                         return 0;
 750         if (i < pathspec->nr || r)
 751                 /* different number of pathspec items and ranges */
 752                 return 0;
 753
 754         return 1;
 755 }
 756
 757 static void parse_pathspec_from_ranges(struct pathspec *pathspec,
 758                                        struct line_log_data *range)
 759 {
 760         struct line_log_data *r;
 761         struct argv_array array = ARGV_ARRAY_INIT;
 762         const char **paths;
 763
 764         for (r = range; r; r = r->next)
 765                 argv_array_push(&array, r->path);
 766         paths = argv_array_detach(&array);
 767
 768         parse_pathspec(pathspec, 0, PATHSPEC_PREFER_FULL, "", paths);
 769         /* strings are now owned by pathspec */
 770         free(paths);
 771 }
 772
 773 void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 774 {
 775         struct commit *commit = NULL;
 776         struct line_log_data *range;
 777
 778         commit = check_single_commit(rev);
 779         range = parse_lines(rev->diffopt.repo, commit, prefix, args);
 780         add_line_range(rev, commit, range);
 781
 782         parse_pathspec_from_ranges(&rev->diffopt.pathspec, range);
 783 }
 784
 785 static void move_diff_queue(struct diff_queue_struct *dst,
 786                             struct diff_queue_struct *src)
 787 {
 788         assert(src != dst);
 789         memcpy(dst, src, sizeof(struct diff_queue_struct));
 790         DIFF_QUEUE_CLEAR(src);
 791 }
 792
 793 static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 794 {
 795         int i;
 796         struct diff_queue_struct outq;
 797         DIFF_QUEUE_CLEAR(&outq);
 798
 799         for (i = 0; i < diff_queued_diff.nr; i++) {
 800                 struct diff_filepair *p = diff_queued_diff.queue[i];
 801                 struct line_log_data *rg = NULL;
 802
 803                 if (!DIFF_FILE_VALID(p->two)) {
 804                         if (keep_deletions)
 805                                 diff_q(&outq, p);
 806                         else
 807                                 diff_free_filepair(p);
 808                         continue;
 809                 }
 810                 for (rg = range; rg; rg = rg->next) {
 811                         if (!strcmp(rg->path, p->two->path))
 812                                 break;
 813                 }
 814                 if (rg)
 815                         diff_q(&outq, p);
 816                 else
 817                         diff_free_filepair(p);
 818         }
 819         free(diff_queued_diff.queue);
 820         diff_queued_diff = outq;
 821 }
 822
 823 static inline int diff_might_be_rename(void)
 824 {
 825         int i;
 826         for (i = 0; i < diff_queued_diff.nr; i++)
 827                 if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 828                         /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 829                         /*      diff_queued_diff.queue[i]->two->path); */
 830                         return 1;
 831                 }
 832         return 0;
 833 }
 834
 835 static void queue_diffs(struct line_log_data *range,
 836                         struct diff_options *opt,
 837                         struct diff_queue_struct *queue,
 838                         struct commit *commit, struct commit *parent)
 839 {
 840         struct object_id *tree_oid, *parent_tree_oid;
 841
 842         assert(commit);
 843
 844         tree_oid = get_commit_tree_oid(commit);
 845         parent_tree_oid = parent ? get_commit_tree_oid(parent) : NULL;
 846
 847         if (opt->detect_rename &&
 848             !same_paths_in_pathspec_and_range(&opt->pathspec, range)) {
 849                 clear_pathspec(&opt->pathspec);
 850                 parse_pathspec_from_ranges(&opt->pathspec, range);
 851         }
 852         DIFF_QUEUE_CLEAR(&diff_queued_diff);
 853         diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
 854         if (opt->detect_rename && diff_might_be_rename()) {
 855                 /* must look at the full tree diff to detect renames */
 856                 clear_pathspec(&opt->pathspec);
 857                 DIFF_QUEUE_CLEAR(&diff_queued_diff);
 858
 859                 diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
 860
 861                 filter_diffs_for_paths(range, 1);
 862                 diffcore_std(opt);
 863                 filter_diffs_for_paths(range, 0);
 864         }
 865         move_diff_queue(queue, &diff_queued_diff);
 866 }
 867
 868 static char *get_nth_line(long line, unsigned long *ends, void *data)
 869 {
 870         if (line == 0)
 871                 return (char *)data;
 872         else
 873                 return (char *)data + ends[line] + 1;
 874 }
 875
 876 static void print_line(const char *prefix, char first,
 877                        long line, unsigned long *ends, void *data,
 878                        const char *color, const char *reset, FILE *file)
 879 {
 880         char *begin = get_nth_line(line, ends, data);
 881         char *end = get_nth_line(line+1, ends, data);
 882         int had_nl = 0;
 883
 884         if (end > begin && end[-1] == '\n') {
 885                 end--;
 886                 had_nl = 1;
 887         }
 888
 889         fputs(prefix, file);
 890         fputs(color, file);
 891         putc(first, file);
 892         fwrite(begin, 1, end-begin, file);
 893         fputs(reset, file);
 894         putc('\n', file);
 895         if (!had_nl)
 896                 fputs("\\ No newline at end of file\n", file);
 897 }
 898
 899 static char *output_prefix(struct diff_options *opt)
 900 {
 901         char *prefix = "";
 902
 903         if (opt->output_prefix) {
 904                 struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 905                 prefix = sb->buf;
 906         }
 907
 908         return prefix;
 909 }
 910
 911 static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 912 {
 913         unsigned int i, j = 0;
 914         long p_lines, t_lines;
 915         unsigned long *p_ends = NULL, *t_ends = NULL;
 916         struct diff_filepair *pair = range->pair;
 917         struct diff_ranges *diff = &range->diff;
 918
 919         struct diff_options *opt = &rev->diffopt;
 920         char *prefix = output_prefix(opt);
 921         const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 922         const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 923         const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 924         const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 925         const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 926         const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 927
 928         if (!pair || !diff)
 929                 return;
 930
 931         if (pair->one->oid_valid)
 932                 fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
 933         fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);
 934
 935         fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 936         fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 937                pair->one->oid_valid ? "a/" : "",
 938                pair->one->oid_valid ? pair->one->path : "/dev/null",
 939                c_reset);
 940         fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 941         for (i = 0; i < range->ranges.nr; i++) {
 942                 long p_start, p_end;
 943                 long t_start = range->ranges.ranges[i].start;
 944                 long t_end = range->ranges.ranges[i].end;
 945                 long t_cur = t_start;
 946                 unsigned int j_last;
 947
 948                 while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 949                         j++;
 950                 if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 951                         continue;
 952
 953                 /* Scan ahead to determine the last diff that falls in this range */
 954                 j_last = j;
 955                 while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 956                         j_last++;
 957                 if (j_last > j)
 958                         j_last--;
 959
 960                 /*
 961                  * Compute parent hunk headers: we know that the diff
 962                  * has the correct line numbers (but not all hunks).
 963                  * So it suffices to shift the start/end according to
 964                  * the line numbers of the first/last hunk(s) that
 965                  * fall in this range.
 966                  */
 967                 if (t_start < diff->target.ranges[j].start)
 968                         p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 969                 else
 970                         p_start = diff->parent.ranges[j].start;
 971                 if (t_end > diff->target.ranges[j_last].end)
 972                         p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 973                 else
 974                         p_end = diff->parent.ranges[j_last].end;
 975
 976                 if (!p_start && !p_end) {
 977                         p_start = -1;
 978                         p_end = -1;
 979                 }
 980
 981                 /* Now output a diff hunk for this range */
 982                 fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 983                        prefix, c_frag,
 984                        p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 985                        c_reset);
 986                 while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 987                         int k;
 988                         for (; t_cur < diff->target.ranges[j].start; t_cur++)
 989                                 print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 990                                            c_context, c_reset, opt->file);
 991                         for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 992                                 print_line(prefix, '-', k, p_ends, pair->one->data,
 993                                            c_old, c_reset, opt->file);
 994                         for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 995                                 print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 996                                            c_new, c_reset, opt->file);
 997                         j++;
 998                 }
 999                 for (; t_cur < t_end; t_cur++)
1000                         print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
1001                                    c_context, c_reset, opt->file);
1002         }
1003
1004         free(p_ends);
1005         free(t_ends);
1006 }
1007
1008 /*
1009  * NEEDSWORK: manually building a diff here is not the Right
1010  * Thing(tm).  log -L should be built into the diff pipeline.
1011  */
1012 static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
1013 {
1014         fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
1015         while (range) {
1016                 dump_diff_hacky_one(rev, range);
1017                 range = range->next;
1018         }
1019 }
1020
1021 /*
1022  * Unlike most other functions, this destructively operates on
1023  * 'range'.
1024  */
1025 static int process_diff_filepair(struct rev_info *rev,
1026                                  struct diff_filepair *pair,
1027                                  struct line_log_data *range,
1028                                  struct diff_ranges **diff_out)
1029 {
1030         struct line_log_data *rg = range;
1031         struct range_set tmp;
1032         struct diff_ranges diff;
1033         mmfile_t file_parent, file_target;
1034
1035         assert(pair->two->path);
1036         while (rg) {
1037                 assert(rg->path);
1038                 if (!strcmp(rg->path, pair->two->path))
1039                         break;
1040                 rg = rg->next;
1041         }
1042
1043         if (!rg)
1044                 return 0;
1045         if (rg->ranges.nr == 0)
1046                 return 0;
1047
1048         assert(pair->two->oid_valid);
1049         diff_populate_filespec(rev->diffopt.repo, pair->two, NULL);
1050         file_target.ptr = pair->two->data;
1051         file_target.size = pair->two->size;
1052
1053         if (pair->one->oid_valid) {
1054                 diff_populate_filespec(rev->diffopt.repo, pair->one, NULL);
1055                 file_parent.ptr = pair->one->data;
1056                 file_parent.size = pair->one->size;
1057         } else {
1058                 file_parent.ptr = "";
1059                 file_parent.size = 0;
1060         }
1061
1062         diff_ranges_init(&diff);
1063         if (collect_diff(&file_parent, &file_target, &diff))
1064                 die("unable to generate diff for %s", pair->one->path);
1065
1066         /* NEEDSWORK should apply some heuristics to prevent mismatches */
1067         free(rg->path);
1068         rg->path = xstrdup(pair->one->path);
1069
1070         range_set_init(&tmp, 0);
1071         range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1072         range_set_release(&rg->ranges);
1073         range_set_move(&rg->ranges, &tmp);
1074
1075         diff_ranges_release(&diff);
1076
1077         return ((*diff_out)->parent.nr > 0);
1078 }
1079
1080 static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1081 {
1082         struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
1083         new_filepair->one = pair->one;
1084         new_filepair->two = pair->two;
1085         new_filepair->one->count++;
1086         new_filepair->two->count++;
1087         return new_filepair;
1088 }
1089
1090 static void free_diffqueues(int n, struct diff_queue_struct *dq)
1091 {
1092         int i, j;
1093         for (i = 0; i < n; i++)
1094                 for (j = 0; j < dq[i].nr; j++)
1095                         diff_free_filepair(dq[i].queue[j]);
1096         free(dq);
1097 }
1098
1099 static int process_all_files(struct line_log_data **range_out,
1100                              struct rev_info *rev,
1101                              struct diff_queue_struct *queue,
1102                              struct line_log_data *range)
1103 {
1104         int i, changed = 0;
1105
1106         *range_out = line_log_data_copy(range);
1107
1108         for (i = 0; i < queue->nr; i++) {
1109                 struct diff_ranges *pairdiff = NULL;
1110                 struct diff_filepair *pair = queue->queue[i];
1111                 if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1112                         /*
1113                          * Store away the diff for later output.  We
1114                          * tuck it in the ranges we got as _input_,
1115                          * since that's the commit that caused the
1116                          * diff.
1117                          *
1118                          * NEEDSWORK not enough when we get around to
1119                          * doing something interesting with merges;
1120                          * currently each invocation on a merge parent
1121                          * trashes the previous one's diff.
1122                          *
1123                          * NEEDSWORK tramples over data structures not owned here
1124                          */
1125                         struct line_log_data *rg = range;
1126                         changed++;
1127                         while (rg && strcmp(rg->path, pair->two->path))
1128                                 rg = rg->next;
1129                         assert(rg);
1130                         rg->pair = diff_filepair_dup(queue->queue[i]);
1131                         memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1132                 }
1133                 free(pairdiff);
1134         }
1135
1136         return changed;
1137 }
1138
1139 int line_log_print(struct rev_info *rev, struct commit *commit)
1140 {
1141
1142         show_log(rev);
1143         if (!(rev->diffopt.output_format & DIFF_FORMAT_NO_OUTPUT)) {
1144                 struct line_log_data *range = lookup_line_range(rev, commit);
1145                 dump_diff_hacky(rev, range);
1146         }
1147         return 1;
1148 }
1149
1150 static int bloom_filter_check(struct rev_info *rev,
1151                               struct commit *commit,
1152                               struct line_log_data *range)
1153 {
1154         struct bloom_filter *filter;
1155         struct bloom_key key;
1156         int result = 0;
1157
1158         if (!commit->parents)
1159                 return 1;
1160
1161         if (!rev->bloom_filter_settings ||
1162             !(filter = get_bloom_filter(rev->repo, commit, 0)))
1163                 return 1;
1164
1165         if (!range)
1166                 return 0;
1167
1168         while (!result && range) {
1169                 fill_bloom_key(range->path, strlen(range->path), &key, rev->bloom_filter_settings);
1170
1171                 if (bloom_filter_contains(filter, &key, rev->bloom_filter_settings))
1172                         result = 1;
1173
1174                 clear_bloom_key(&key);
1175                 range = range->next;
1176         }
1177
1178         return result;
1179 }
1180
1181 static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1182                                           struct line_log_data *range)
1183 {
1184         struct commit *parent = NULL;
1185         struct diff_queue_struct queue;
1186         struct line_log_data *parent_range;
1187         int changed;
1188
1189         if (commit->parents)
1190                 parent = commit->parents->item;
1191
1192         queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1193         changed = process_all_files(&parent_range, rev, &queue, range);
1194
1195         if (parent)
1196                 add_line_range(rev, parent, parent_range);
1197         free_line_log_data(parent_range);
1198         return changed;
1199 }
1200
1201 static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1202                                        struct line_log_data *range)
1203 {
1204         struct diff_queue_struct *diffqueues;
1205         struct line_log_data **cand;
1206         struct commit **parents;
1207         struct commit_list *p;
1208         int i;
1209         int nparents = commit_list_count(commit->parents);
1210
1211         if (nparents > 1 && rev->first_parent_only)
1212                 nparents = 1;
1213
1214         ALLOC_ARRAY(diffqueues, nparents);
1215         ALLOC_ARRAY(cand, nparents);
1216         ALLOC_ARRAY(parents, nparents);
1217
1218         p = commit->parents;
1219         for (i = 0; i < nparents; i++) {
1220                 parents[i] = p->item;
1221                 p = p->next;
1222                 queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1223         }
1224
1225         for (i = 0; i < nparents; i++) {
1226                 int changed;
1227                 cand[i] = NULL;
1228                 changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1229                 if (!changed) {
1230                         /*
1231                          * This parent can take all the blame, so we
1232                          * don't follow any other path in history
1233                          */
1234                         add_line_range(rev, parents[i], cand[i]);
1235                         clear_commit_line_range(rev, commit);
1236                         commit_list_append(parents[i], &commit->parents);
1237                         free(parents);
1238                         free(cand);
1239                         free_diffqueues(nparents, diffqueues);
1240                         /* NEEDSWORK leaking like a sieve */
1241                         return 0;
1242                 }
1243         }
1244
1245         /*
1246          * No single parent took the blame.  We add the candidates
1247          * from the above loop to the parents.
1248          */
1249         for (i = 0; i < nparents; i++) {
1250                 add_line_range(rev, parents[i], cand[i]);
1251         }
1252
1253         clear_commit_line_range(rev, commit);
1254         free(parents);
1255         free(cand);
1256         free_diffqueues(nparents, diffqueues);
1257         return 1;
1258
1259         /* NEEDSWORK evil merge detection stuff */
1260         /* NEEDSWORK leaking like a sieve */
1261 }
1262
1263 int line_log_process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1264 {
1265         struct line_log_data *range = lookup_line_range(rev, commit);
1266         int changed = 0;
1267
1268         if (range) {
1269                 if (commit->parents && !bloom_filter_check(rev, commit, range)) {
1270                         struct line_log_data *prange = line_log_data_copy(range);
1271                         add_line_range(rev, commit->parents->item, prange);
1272                         clear_commit_line_range(rev, commit);
1273                 } else if (!commit->parents || !commit->parents->next)
1274                         changed = process_ranges_ordinary_commit(rev, commit, range);
1275                 else
1276                         changed = process_ranges_merge_commit(rev, commit, range);
1277         }
1278
1279         if (!changed)
1280                 commit->object.flags |= TREESAME;
1281
1282         return changed;
1283 }
1284
1285 static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1286 {
1287         for (;;) {
1288                 struct commit *p = *pp;
1289                 if (p->parents && p->parents->next)
1290                         return rewrite_one_ok;
1291                 if (p->object.flags & UNINTERESTING)
1292                         return rewrite_one_ok;
1293                 if (!(p->object.flags & TREESAME))
1294                         return rewrite_one_ok;
1295                 if (!p->parents)
1296                         return rewrite_one_noparents;
1297                 *pp = p->parents->item;
1298         }
1299 }
1300
1301 int line_log_filter(struct rev_info *rev)
1302 {
1303         struct commit *commit;
1304         struct commit_list *list = rev->commits;
1305         struct commit_list *out = NULL, **pp = &out;
1306
1307         while (list) {
1308                 struct commit_list *to_free = NULL;
1309                 commit = list->item;
1310                 if (line_log_process_ranges_arbitrary_commit(rev, commit)) {
1311                         *pp = list;
1312                         pp = &list->next;
1313                 } else
1314                         to_free = list;
1315                 list = list->next;
1316                 free(to_free);
1317         }
1318         *pp = NULL;
1319
1320         for (list = out; list; list = list->next)
1321                 rewrite_parents(rev, list->item, line_log_rewrite_one);
1322
1323         rev->commits = out;
1324
1325         return 0;
1326 }