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(rs->ranges);
  38         rs->alloc = rs->nr = 0;
  39         rs->ranges = NULL;
  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         memcpy(dst->ranges, src->ranges, src->nr*sizeof(struct range_set));
  47         dst->nr = src->nr;
  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         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         int i;
 114         int o = 0; /* output cursor */
 115
 116         qsort(rs->ranges, rs->nr, sizeof(struct range), 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         int i = 0, j = 0, o = 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;
 155                 if (i < a->nr && j < b->nr) {
 156                         if (ra[i].start < rb[j].start)
 157                                 new = &ra[i++];
 158                         else if (ra[i].start > rb[j].start)
 159                                 new = &rb[j++];
 160                         else if (ra[i].end < rb[j].end)
 161                                 new = &ra[i++];
 162                         else
 163                                 new = &rb[j++];
 164                 } else if (i < a->nr)      /* b exhausted */
 165                         new = &ra[i++];
 166                 else                       /* a exhausted */
 167                         new = &rb[j++];
 168                 if (new->start == new->end)
 169                         ; /* empty range */
 170                 else if (!o || out->ranges[o-1].end < new->start) {
 171                         range_set_grow(out, 1);
 172                         out->ranges[o].start = new->start;
 173                         out->ranges[o].end = new->end;
 174                         o++;
 175                 } else if (out->ranges[o-1].end < new->end) {
 176                         out->ranges[o-1].end = new->end;
 177                 }
 178         }
 179         out->nr = o;
 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         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         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         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                 while (obj->type == OBJ_TAG)
 484                         obj = deref_tag(obj, NULL, 0);
 485                 if (obj->type != OBJ_COMMIT)
 486                         die("Non commit %s?", revs->pending.objects[i].name);
 487                 if (commit)
 488                         die("More than one commit to dig from: %s and %s?",
 489                             revs->pending.objects[i].name,
 490                             revs->pending.objects[found].name);
 491                 commit = obj;
 492                 found = i;
 493         }
 494
 495         if (!commit)
 496                 die("No commit specified?");
 497
 498         return (struct commit *) commit;
 499 }
 500
 501 static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
 502 {
 503         unsigned mode;
 504         unsigned char sha1[20];
 505
 506         if (get_tree_entry(commit->object.oid.hash, spec->path,
 507                            sha1, &mode))
 508                 die("There is no path %s in the commit", spec->path);
 509         fill_filespec(spec, sha1, 1, mode);
 510
 511         return;
 512 }
 513
 514 static void fill_line_ends(struct diff_filespec *spec, long *lines,
 515                            unsigned long **line_ends)
 516 {
 517         int num = 0, size = 50;
 518         long cur = 0;
 519         unsigned long *ends = NULL;
 520         char *data = NULL;
 521
 522         if (diff_populate_filespec(spec, 0))
 523                 die("Cannot read blob %s", sha1_to_hex(spec->sha1));
 524
 525         ALLOC_ARRAY(ends, size);
 526         ends[cur++] = 0;
 527         data = spec->data;
 528         while (num < spec->size) {
 529                 if (data[num] == '\n' || num == spec->size - 1) {
 530                         ALLOC_GROW(ends, (cur + 1), size);
 531                         ends[cur++] = num;
 532                 }
 533                 num++;
 534         }
 535
 536         /* shrink the array to fit the elements */
 537         REALLOC_ARRAY(ends, cur);
 538         *lines = cur-1;
 539         *line_ends = ends;
 540 }
 541
 542 struct nth_line_cb {
 543         struct diff_filespec *spec;
 544         long lines;
 545         unsigned long *line_ends;
 546 };
 547
 548 static const char *nth_line(void *data, long line)
 549 {
 550         struct nth_line_cb *d = data;
 551         assert(d && line <= d->lines);
 552         assert(d->spec && d->spec->data);
 553
 554         if (line == 0)
 555                 return (char *)d->spec->data;
 556         else
 557                 return (char *)d->spec->data + d->line_ends[line] + 1;
 558 }
 559
 560 static struct line_log_data *
 561 parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 562 {
 563         long lines = 0;
 564         unsigned long *ends = NULL;
 565         struct nth_line_cb cb_data;
 566         struct string_list_item *item;
 567         struct line_log_data *ranges = NULL;
 568         struct line_log_data *p;
 569
 570         for_each_string_list_item(item, args) {
 571                 const char *name_part, *range_part;
 572                 char *full_name;
 573                 struct diff_filespec *spec;
 574                 long begin = 0, end = 0;
 575                 long anchor;
 576
 577                 name_part = skip_range_arg(item->string);
 578                 if (!name_part || *name_part != ':' || !name_part[1])
 579                         die("-L argument not 'start,end:file' or ':funcname:file': %s",
 580                             item->string);
 581                 range_part = xstrndup(item->string, name_part - item->string);
 582                 name_part++;
 583
 584                 full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 585                                         name_part);
 586
 587                 spec = alloc_filespec(full_name);
 588                 fill_blob_sha1(commit, spec);
 589                 fill_line_ends(spec, &lines, &ends);
 590                 cb_data.spec = spec;
 591                 cb_data.lines = lines;
 592                 cb_data.line_ends = ends;
 593
 594                 p = search_line_log_data(ranges, full_name, NULL);
 595                 if (p && p->ranges.nr)
 596                         anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 597                 else
 598                         anchor = 1;
 599
 600                 if (parse_range_arg(range_part, nth_line, &cb_data,
 601                                     lines, anchor, &begin, &end,
 602                                     full_name))
 603                         die("malformed -L argument '%s'", range_part);
 604                 if (lines < end || ((lines || begin) && lines < begin))
 605                         die("file %s has only %lu lines", name_part, lines);
 606                 if (begin < 1)
 607                         begin = 1;
 608                 if (end < 1)
 609                         end = lines;
 610                 begin--;
 611                 line_log_data_insert(&ranges, full_name, begin, end);
 612
 613                 free_filespec(spec);
 614                 free(ends);
 615                 ends = NULL;
 616         }
 617
 618         for (p = ranges; p; p = p->next)
 619                 sort_and_merge_range_set(&p->ranges);
 620
 621         return ranges;
 622 }
 623
 624 static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 625 {
 626         struct line_log_data *ret = xmalloc(sizeof(*ret));
 627
 628         assert(r);
 629         line_log_data_init(ret);
 630         range_set_copy(&ret->ranges, &r->ranges);
 631
 632         ret->path = xstrdup(r->path);
 633
 634         return ret;
 635 }
 636
 637 static struct line_log_data *
 638 line_log_data_copy(struct line_log_data *r)
 639 {
 640         struct line_log_data *ret = NULL;
 641         struct line_log_data *tmp = NULL, *prev = NULL;
 642
 643         assert(r);
 644         ret = tmp = prev = line_log_data_copy_one(r);
 645         r = r->next;
 646         while (r) {
 647                 tmp = line_log_data_copy_one(r);
 648                 prev->next = tmp;
 649                 prev = tmp;
 650                 r = r->next;
 651         }
 652
 653         return ret;
 654 }
 655
 656 /* merge two range sets across files */
 657 static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 658                                                  struct line_log_data *b)
 659 {
 660         struct line_log_data *head = NULL, **pp = &head;
 661
 662         while (a || b) {
 663                 struct line_log_data *src;
 664                 struct line_log_data *src2 = NULL;
 665                 struct line_log_data *d;
 666                 int cmp;
 667                 if (!a)
 668                         cmp = 1;
 669                 else if (!b)
 670                         cmp = -1;
 671                 else
 672                         cmp = strcmp(a->path, b->path);
 673                 if (cmp < 0) {
 674                         src = a;
 675                         a = a->next;
 676                 } else if (cmp == 0) {
 677                         src = a;
 678                         a = a->next;
 679                         src2 = b;
 680                         b = b->next;
 681                 } else {
 682                         src = b;
 683                         b = b->next;
 684                 }
 685                 d = xmalloc(sizeof(struct line_log_data));
 686                 line_log_data_init(d);
 687                 d->path = xstrdup(src->path);
 688                 *pp = d;
 689                 pp = &d->next;
 690                 if (src2)
 691                         range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 692                 else
 693                         range_set_copy(&d->ranges, &src->ranges);
 694         }
 695
 696         return head;
 697 }
 698
 699 static void add_line_range(struct rev_info *revs, struct commit *commit,
 700                            struct line_log_data *range)
 701 {
 702         struct line_log_data *old = NULL;
 703         struct line_log_data *new = NULL;
 704
 705         old = lookup_decoration(&revs->line_log_data, &commit->object);
 706         if (old && range) {
 707                 new = line_log_data_merge(old, range);
 708                 free_line_log_data(old);
 709         } else if (range)
 710                 new = line_log_data_copy(range);
 711
 712         if (new)
 713                 add_decoration(&revs->line_log_data, &commit->object, new);
 714 }
 715
 716 static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 717 {
 718         struct line_log_data *r;
 719         r = lookup_decoration(&revs->line_log_data, &commit->object);
 720         if (!r)
 721                 return;
 722         free_line_log_data(r);
 723         add_decoration(&revs->line_log_data, &commit->object, NULL);
 724 }
 725
 726 static struct line_log_data *lookup_line_range(struct rev_info *revs,
 727                                                struct commit *commit)
 728 {
 729         struct line_log_data *ret = NULL;
 730         struct line_log_data *d;
 731
 732         ret = lookup_decoration(&revs->line_log_data, &commit->object);
 733
 734         for (d = ret; d; d = d->next)
 735                 range_set_check_invariants(&d->ranges);
 736
 737         return ret;
 738 }
 739
 740 void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 741 {
 742         struct commit *commit = NULL;
 743         struct line_log_data *range;
 744
 745         commit = check_single_commit(rev);
 746         range = parse_lines(commit, prefix, args);
 747         add_line_range(rev, commit, range);
 748
 749         if (!rev->diffopt.detect_rename) {
 750                 struct line_log_data *r;
 751                 struct argv_array array = ARGV_ARRAY_INIT;
 752                 const char **paths;
 753
 754                 for (r = range; r; r = r->next)
 755                         argv_array_push(&array, r->path);
 756                 paths = argv_array_detach(&array);
 757
 758                 parse_pathspec(&rev->diffopt.pathspec, 0,
 759                                PATHSPEC_PREFER_FULL, "", paths);
 760                 /* strings are now owned by pathspec */
 761                 free(paths);
 762         }
 763 }
 764
 765 static void move_diff_queue(struct diff_queue_struct *dst,
 766                             struct diff_queue_struct *src)
 767 {
 768         assert(src != dst);
 769         memcpy(dst, src, sizeof(struct diff_queue_struct));
 770         DIFF_QUEUE_CLEAR(src);
 771 }
 772
 773 static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 774 {
 775         int i;
 776         struct diff_queue_struct outq;
 777         DIFF_QUEUE_CLEAR(&outq);
 778
 779         for (i = 0; i < diff_queued_diff.nr; i++) {
 780                 struct diff_filepair *p = diff_queued_diff.queue[i];
 781                 struct line_log_data *rg = NULL;
 782
 783                 if (!DIFF_FILE_VALID(p->two)) {
 784                         if (keep_deletions)
 785                                 diff_q(&outq, p);
 786                         else
 787                                 diff_free_filepair(p);
 788                         continue;
 789                 }
 790                 for (rg = range; rg; rg = rg->next) {
 791                         if (!strcmp(rg->path, p->two->path))
 792                                 break;
 793                 }
 794                 if (rg)
 795                         diff_q(&outq, p);
 796                 else
 797                         diff_free_filepair(p);
 798         }
 799         free(diff_queued_diff.queue);
 800         diff_queued_diff = outq;
 801 }
 802
 803 static inline int diff_might_be_rename(void)
 804 {
 805         int i;
 806         for (i = 0; i < diff_queued_diff.nr; i++)
 807                 if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 808                         /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 809                         /*      diff_queued_diff.queue[i]->two->path); */
 810                         return 1;
 811                 }
 812         return 0;
 813 }
 814
 815 static void queue_diffs(struct line_log_data *range,
 816                         struct diff_options *opt,
 817                         struct diff_queue_struct *queue,
 818                         struct commit *commit, struct commit *parent)
 819 {
 820         assert(commit);
 821
 822         DIFF_QUEUE_CLEAR(&diff_queued_diff);
 823         diff_tree_sha1(parent ? parent->tree->object.oid.hash : NULL,
 824                         commit->tree->object.oid.hash, "", opt);
 825         if (opt->detect_rename) {
 826                 filter_diffs_for_paths(range, 1);
 827                 if (diff_might_be_rename())
 828                         diffcore_std(opt);
 829                 filter_diffs_for_paths(range, 0);
 830         }
 831         move_diff_queue(queue, &diff_queued_diff);
 832 }
 833
 834 static char *get_nth_line(long line, unsigned long *ends, void *data)
 835 {
 836         if (line == 0)
 837                 return (char *)data;
 838         else
 839                 return (char *)data + ends[line] + 1;
 840 }
 841
 842 static void print_line(const char *prefix, char first,
 843                        long line, unsigned long *ends, void *data,
 844                        const char *color, const char *reset)
 845 {
 846         char *begin = get_nth_line(line, ends, data);
 847         char *end = get_nth_line(line+1, ends, data);
 848         int had_nl = 0;
 849
 850         if (end > begin && end[-1] == '\n') {
 851                 end--;
 852                 had_nl = 1;
 853         }
 854
 855         fputs(prefix, stdout);
 856         fputs(color, stdout);
 857         putchar(first);
 858         fwrite(begin, 1, end-begin, stdout);
 859         fputs(reset, stdout);
 860         putchar('\n');
 861         if (!had_nl)
 862                 fputs("\\ No newline at end of file\n", stdout);
 863 }
 864
 865 static char *output_prefix(struct diff_options *opt)
 866 {
 867         char *prefix = "";
 868
 869         if (opt->output_prefix) {
 870                 struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 871                 prefix = sb->buf;
 872         }
 873
 874         return prefix;
 875 }
 876
 877 static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 878 {
 879         int i, j = 0;
 880         long p_lines, t_lines;
 881         unsigned long *p_ends = NULL, *t_ends = NULL;
 882         struct diff_filepair *pair = range->pair;
 883         struct diff_ranges *diff = &range->diff;
 884
 885         struct diff_options *opt = &rev->diffopt;
 886         char *prefix = output_prefix(opt);
 887         const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 888         const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 889         const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 890         const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 891         const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 892         const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 893
 894         if (!pair || !diff)
 895                 return;
 896
 897         if (pair->one->sha1_valid)
 898                 fill_line_ends(pair->one, &p_lines, &p_ends);
 899         fill_line_ends(pair->two, &t_lines, &t_ends);
 900
 901         printf("%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 902         printf("%s%s--- %s%s%s\n", prefix, c_meta,
 903                pair->one->sha1_valid ? "a/" : "",
 904                pair->one->sha1_valid ? pair->one->path : "/dev/null",
 905                c_reset);
 906         printf("%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 907         for (i = 0; i < range->ranges.nr; i++) {
 908                 long p_start, p_end;
 909                 long t_start = range->ranges.ranges[i].start;
 910                 long t_end = range->ranges.ranges[i].end;
 911                 long t_cur = t_start;
 912                 int j_last;
 913
 914                 while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 915                         j++;
 916                 if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 917                         continue;
 918
 919                 /* Scan ahead to determine the last diff that falls in this range */
 920                 j_last = j;
 921                 while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 922                         j_last++;
 923                 if (j_last > j)
 924                         j_last--;
 925
 926                 /*
 927                  * Compute parent hunk headers: we know that the diff
 928                  * has the correct line numbers (but not all hunks).
 929                  * So it suffices to shift the start/end according to
 930                  * the line numbers of the first/last hunk(s) that
 931                  * fall in this range.
 932                  */
 933                 if (t_start < diff->target.ranges[j].start)
 934                         p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 935                 else
 936                         p_start = diff->parent.ranges[j].start;
 937                 if (t_end > diff->target.ranges[j_last].end)
 938                         p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 939                 else
 940                         p_end = diff->parent.ranges[j_last].end;
 941
 942                 if (!p_start && !p_end) {
 943                         p_start = -1;
 944                         p_end = -1;
 945                 }
 946
 947                 /* Now output a diff hunk for this range */
 948                 printf("%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 949                        prefix, c_frag,
 950                        p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 951                        c_reset);
 952                 while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 953                         int k;
 954                         for (; t_cur < diff->target.ranges[j].start; t_cur++)
 955                                 print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 956                                            c_context, c_reset);
 957                         for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 958                                 print_line(prefix, '-', k, p_ends, pair->one->data,
 959                                            c_old, c_reset);
 960                         for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 961                                 print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 962                                            c_new, c_reset);
 963                         j++;
 964                 }
 965                 for (; t_cur < t_end; t_cur++)
 966                         print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 967                                    c_context, c_reset);
 968         }
 969
 970         free(p_ends);
 971         free(t_ends);
 972 }
 973
 974 /*
 975  * NEEDSWORK: manually building a diff here is not the Right
 976  * Thing(tm).  log -L should be built into the diff pipeline.
 977  */
 978 static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 979 {
 980         puts(output_prefix(&rev->diffopt));
 981         while (range) {
 982                 dump_diff_hacky_one(rev, range);
 983                 range = range->next;
 984         }
 985 }
 986
 987 /*
 988  * Unlike most other functions, this destructively operates on
 989  * 'range'.
 990  */
 991 static int process_diff_filepair(struct rev_info *rev,
 992                                  struct diff_filepair *pair,
 993                                  struct line_log_data *range,
 994                                  struct diff_ranges **diff_out)
 995 {
 996         struct line_log_data *rg = range;
 997         struct range_set tmp;
 998         struct diff_ranges diff;
 999         mmfile_t file_parent, file_target;
1000
1001         assert(pair->two->path);
1002         while (rg) {
1003                 assert(rg->path);
1004                 if (!strcmp(rg->path, pair->two->path))
1005                         break;
1006                 rg = rg->next;
1007         }
1008
1009         if (!rg)
1010                 return 0;
1011         if (rg->ranges.nr == 0)
1012                 return 0;
1013
1014         assert(pair->two->sha1_valid);
1015         diff_populate_filespec(pair->two, 0);
1016         file_target.ptr = pair->two->data;
1017         file_target.size = pair->two->size;
1018
1019         if (pair->one->sha1_valid) {
1020                 diff_populate_filespec(pair->one, 0);
1021                 file_parent.ptr = pair->one->data;
1022                 file_parent.size = pair->one->size;
1023         } else {
1024                 file_parent.ptr = "";
1025                 file_parent.size = 0;
1026         }
1027
1028         diff_ranges_init(&diff);
1029         if (collect_diff(&file_parent, &file_target, &diff))
1030                 die("unable to generate diff for %s", pair->one->path);
1031
1032         /* NEEDSWORK should apply some heuristics to prevent mismatches */
1033         free(rg->path);
1034         rg->path = xstrdup(pair->one->path);
1035
1036         range_set_init(&tmp, 0);
1037         range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1038         range_set_release(&rg->ranges);
1039         range_set_move(&rg->ranges, &tmp);
1040
1041         diff_ranges_release(&diff);
1042
1043         return ((*diff_out)->parent.nr > 0);
1044 }
1045
1046 static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1047 {
1048         struct diff_filepair *new = xmalloc(sizeof(struct diff_filepair));
1049         new->one = pair->one;
1050         new->two = pair->two;
1051         new->one->count++;
1052         new->two->count++;
1053         return new;
1054 }
1055
1056 static void free_diffqueues(int n, struct diff_queue_struct *dq)
1057 {
1058         int i, j;
1059         for (i = 0; i < n; i++)
1060                 for (j = 0; j < dq[i].nr; j++)
1061                         diff_free_filepair(dq[i].queue[j]);
1062         free(dq);
1063 }
1064
1065 static int process_all_files(struct line_log_data **range_out,
1066                              struct rev_info *rev,
1067                              struct diff_queue_struct *queue,
1068                              struct line_log_data *range)
1069 {
1070         int i, changed = 0;
1071
1072         *range_out = line_log_data_copy(range);
1073
1074         for (i = 0; i < queue->nr; i++) {
1075                 struct diff_ranges *pairdiff = NULL;
1076                 struct diff_filepair *pair = queue->queue[i];
1077                 if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1078                         /*
1079                          * Store away the diff for later output.  We
1080                          * tuck it in the ranges we got as _input_,
1081                          * since that's the commit that caused the
1082                          * diff.
1083                          *
1084                          * NEEDSWORK not enough when we get around to
1085                          * doing something interesting with merges;
1086                          * currently each invocation on a merge parent
1087                          * trashes the previous one's diff.
1088                          *
1089                          * NEEDSWORK tramples over data structures not owned here
1090                          */
1091                         struct line_log_data *rg = range;
1092                         changed++;
1093                         while (rg && strcmp(rg->path, pair->two->path))
1094                                 rg = rg->next;
1095                         assert(rg);
1096                         rg->pair = diff_filepair_dup(queue->queue[i]);
1097                         memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1098                 }
1099                 free(pairdiff);
1100         }
1101
1102         return changed;
1103 }
1104
1105 int line_log_print(struct rev_info *rev, struct commit *commit)
1106 {
1107         struct line_log_data *range = lookup_line_range(rev, commit);
1108
1109         show_log(rev);
1110         dump_diff_hacky(rev, range);
1111         return 1;
1112 }
1113
1114 static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1115                                           struct line_log_data *range)
1116 {
1117         struct commit *parent = NULL;
1118         struct diff_queue_struct queue;
1119         struct line_log_data *parent_range;
1120         int changed;
1121
1122         if (commit->parents)
1123                 parent = commit->parents->item;
1124
1125         queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1126         changed = process_all_files(&parent_range, rev, &queue, range);
1127         if (parent)
1128                 add_line_range(rev, parent, parent_range);
1129         return changed;
1130 }
1131
1132 static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1133                                        struct line_log_data *range)
1134 {
1135         struct diff_queue_struct *diffqueues;
1136         struct line_log_data **cand;
1137         struct commit **parents;
1138         struct commit_list *p;
1139         int i;
1140         int nparents = commit_list_count(commit->parents);
1141
1142         if (nparents > 1 && rev->first_parent_only)
1143                 nparents = 1;
1144
1145         ALLOC_ARRAY(diffqueues, nparents);
1146         ALLOC_ARRAY(cand, nparents);
1147         ALLOC_ARRAY(parents, nparents);
1148
1149         p = commit->parents;
1150         for (i = 0; i < nparents; i++) {
1151                 parents[i] = p->item;
1152                 p = p->next;
1153                 queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1154         }
1155
1156         for (i = 0; i < nparents; i++) {
1157                 int changed;
1158                 cand[i] = NULL;
1159                 changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1160                 if (!changed) {
1161                         /*
1162                          * This parent can take all the blame, so we
1163                          * don't follow any other path in history
1164                          */
1165                         add_line_range(rev, parents[i], cand[i]);
1166                         clear_commit_line_range(rev, commit);
1167                         commit_list_append(parents[i], &commit->parents);
1168                         free(parents);
1169                         free(cand);
1170                         free_diffqueues(nparents, diffqueues);
1171                         /* NEEDSWORK leaking like a sieve */
1172                         return 0;
1173                 }
1174         }
1175
1176         /*
1177          * No single parent took the blame.  We add the candidates
1178          * from the above loop to the parents.
1179          */
1180         for (i = 0; i < nparents; i++) {
1181                 add_line_range(rev, parents[i], cand[i]);
1182         }
1183
1184         clear_commit_line_range(rev, commit);
1185         free(parents);
1186         free(cand);
1187         free_diffqueues(nparents, diffqueues);
1188         return 1;
1189
1190         /* NEEDSWORK evil merge detection stuff */
1191         /* NEEDSWORK leaking like a sieve */
1192 }
1193
1194 static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1195 {
1196         struct line_log_data *range = lookup_line_range(rev, commit);
1197         int changed = 0;
1198
1199         if (range) {
1200                 if (!commit->parents || !commit->parents->next)
1201                         changed = process_ranges_ordinary_commit(rev, commit, range);
1202                 else
1203                         changed = process_ranges_merge_commit(rev, commit, range);
1204         }
1205
1206         if (!changed)
1207                 commit->object.flags |= TREESAME;
1208
1209         return changed;
1210 }
1211
1212 static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1213 {
1214         for (;;) {
1215                 struct commit *p = *pp;
1216                 if (p->parents && p->parents->next)
1217                         return rewrite_one_ok;
1218                 if (p->object.flags & UNINTERESTING)
1219                         return rewrite_one_ok;
1220                 if (!(p->object.flags & TREESAME))
1221                         return rewrite_one_ok;
1222                 if (!p->parents)
1223                         return rewrite_one_noparents;
1224                 *pp = p->parents->item;
1225         }
1226 }
1227
1228 int line_log_filter(struct rev_info *rev)
1229 {
1230         struct commit *commit;
1231         struct commit_list *list = rev->commits;
1232         struct commit_list *out = NULL, **pp = &out;
1233
1234         while (list) {
1235                 struct commit_list *to_free = NULL;
1236                 commit = list->item;
1237                 if (process_ranges_arbitrary_commit(rev, commit)) {
1238                         *pp = list;
1239                         pp = &list->next;
1240                 } else
1241                         to_free = list;
1242                 list = list->next;
1243                 free(to_free);
1244         }
1245         *pp = NULL;
1246
1247         for (list = out; list; list = list->next)
1248                 rewrite_parents(rev, list->item, line_log_rewrite_one);
1249
1250         rev->commits = out;
1251
1252         return 0;
1253 }