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
  19 static 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
  27 void 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
  35 void 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! */
  42 static 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
  49 static 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_ */
  60 void 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
  69 void 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
  75 static 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  */
  91 static 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  */
 111 void 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  */
 144 static 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  */
 186 static 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
 228 static 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
 234 static void diff_ranges_release(struct diff_ranges *diff)
 235 {
 236         range_set_release(&diff->parent);
 237         range_set_release(&diff->target);
 238 }
 239
 240 static 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
 246 static 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
 253 static 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
 263 static struct line_log_data *
 264 search_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  */
 285 static 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
 310 struct collect_diff_cbdata {
 311         struct diff_ranges *diff;
 312 };
 313
 314 static 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
 328 static 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
 351 static 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
 359 static 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
 369 static 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
 386 static 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  */
 396 static 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  */
 425 static 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  */
 452 static 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
 472 static 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
 499 static 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
 511 static 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
 539 struct nth_line_cb {
 540         struct diff_filespec *spec;
 541         long lines;
 542         unsigned long *line_ends;
 543 };
 544
 545 static 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
 557 static struct line_log_data *
 558 parse_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
 620 static 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
 633 static struct line_log_data *
 634 line_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 */
 653 static 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
 695 static 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
 712 static 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
 722 static 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
 736 void 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
 761 static 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
 769 static 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
 799 static 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
 811 static 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
 830 static 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
 838 static 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
 861 static 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
 873 static 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  */
 974 static 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  */
 987 static 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
1042 static 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
1052 static 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
1061 static 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
1101 int 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
1110 static 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
1129 static 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
1191 static 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
1209 static 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
1225 int 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 }