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         COPY_ARRAY(dst->ranges, src->ranges, src->nr);
  47         dst->nr = src->nr;
  48 }
  49
  50 static void range_set_move(struct range_set *dst, struct range_set *src)
  51 {
  52         range_set_release(dst);
  53         dst->ranges = src->ranges;
  54         dst->nr = src->nr;
  55         dst->alloc = src->alloc;
  56         src->ranges = NULL;
  57         src->alloc = src->nr = 0;
  58 }
  59
  60 /* tack on a _new_ range _at the end_ */
  61 void range_set_append_unsafe(struct range_set *rs, long a, long b)
  62 {
  63         assert(a <= b);
  64         range_set_grow(rs, 1);
  65         rs->ranges[rs->nr].start = a;
  66         rs->ranges[rs->nr].end = b;
  67         rs->nr++;
  68 }
  69
  70 void range_set_append(struct range_set *rs, long a, long b)
  71 {
  72         assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
  73         range_set_append_unsafe(rs, a, b);
  74 }
  75
  76 static int range_cmp(const void *_r, const void *_s)
  77 {
  78         const struct range *r = _r;
  79         const struct range *s = _s;
  80
  81         /* this could be simply 'return r.start-s.start', but for the types */
  82         if (r->start == s->start)
  83                 return 0;
  84         if (r->start < s->start)
  85                 return -1;
  86         return 1;
  87 }
  88
  89 /*
  90  * Check that the ranges are non-empty, sorted and non-overlapping
  91  */
  92 static void range_set_check_invariants(struct range_set *rs)
  93 {
  94         int i;
  95
  96         if (!rs)
  97                 return;
  98
  99         if (rs->nr)
 100                 assert(rs->ranges[0].start < rs->ranges[0].end);
 101
 102         for (i = 1; i < rs->nr; i++) {
 103                 assert(rs->ranges[i-1].end < rs->ranges[i].start);
 104                 assert(rs->ranges[i].start < rs->ranges[i].end);
 105         }
 106 }
 107
 108 /*
 109  * In-place pass of sorting and merging the ranges in the range set,
 110  * to establish the invariants when we get the ranges from the user
 111  */
 112 void sort_and_merge_range_set(struct range_set *rs)
 113 {
 114         int i;
 115         int o = 0; /* output cursor */
 116
 117         QSORT(rs->ranges, rs->nr, range_cmp);
 118
 119         for (i = 0; i < rs->nr; i++) {
 120                 if (rs->ranges[i].start == rs->ranges[i].end)
 121                         continue;
 122                 if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
 123                         if (rs->ranges[o-1].end < rs->ranges[i].end)
 124                                 rs->ranges[o-1].end = rs->ranges[i].end;
 125                 } else {
 126                         rs->ranges[o].start = rs->ranges[i].start;
 127                         rs->ranges[o].end = rs->ranges[i].end;
 128                         o++;
 129                 }
 130         }
 131         assert(o <= rs->nr);
 132         rs->nr = o;
 133
 134         range_set_check_invariants(rs);
 135 }
 136
 137 /*
 138  * Union of range sets (i.e., sets of line numbers).  Used to merge
 139  * them when searches meet at a common ancestor.
 140  *
 141  * This is also where the ranges are consolidated into canonical form:
 142  * overlapping and adjacent ranges are merged, and empty ranges are
 143  * removed.
 144  */
 145 static void range_set_union(struct range_set *out,
 146                              struct range_set *a, struct range_set *b)
 147 {
 148         int i = 0, j = 0;
 149         struct range *ra = a->ranges;
 150         struct range *rb = b->ranges;
 151         /* cannot make an alias of out->ranges: it may change during grow */
 152
 153         assert(out->nr == 0);
 154         while (i < a->nr || j < b->nr) {
 155                 struct range *new;
 156                 if (i < a->nr && j < b->nr) {
 157                         if (ra[i].start < rb[j].start)
 158                                 new = &ra[i++];
 159                         else if (ra[i].start > rb[j].start)
 160                                 new = &rb[j++];
 161                         else if (ra[i].end < rb[j].end)
 162                                 new = &ra[i++];
 163                         else
 164                                 new = &rb[j++];
 165                 } else if (i < a->nr)      /* b exhausted */
 166                         new = &ra[i++];
 167                 else                       /* a exhausted */
 168                         new = &rb[j++];
 169                 if (new->start == new->end)
 170                         ; /* empty range */
 171                 else if (!out->nr || out->ranges[out->nr-1].end < new->start) {
 172                         range_set_grow(out, 1);
 173                         out->ranges[out->nr].start = new->start;
 174                         out->ranges[out->nr].end = new->end;
 175                         out->nr++;
 176                 } else if (out->ranges[out->nr-1].end < new->end) {
 177                         out->ranges[out->nr-1].end = new->end;
 178                 }
 179         }
 180 }
 181
 182 /*
 183  * Difference of range sets (out = a \ b).  Pass the "interesting"
 184  * ranges as 'a' and the target side of the diff as 'b': it removes
 185  * the ranges for which the commit is responsible.
 186  */
 187 static void range_set_difference(struct range_set *out,
 188                                   struct range_set *a, struct range_set *b)
 189 {
 190         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                 obj = deref_tag(obj, NULL, 0);
 484                 if (obj->type != OBJ_COMMIT)
 485                         die("Non commit %s?", revs->pending.objects[i].name);
 486                 if (commit)
 487                         die("More than one commit to dig from: %s and %s?",
 488                             revs->pending.objects[i].name,
 489                             revs->pending.objects[found].name);
 490                 commit = obj;
 491                 found = i;
 492         }
 493
 494         if (!commit)
 495                 die("No commit specified?");
 496
 497         return (struct commit *) commit;
 498 }
 499
 500 static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
 501 {
 502         unsigned mode;
 503         unsigned char sha1[20];
 504
 505         if (get_tree_entry(commit->object.oid.hash, spec->path,
 506                            sha1, &mode))
 507                 die("There is no path %s in the commit", spec->path);
 508         fill_filespec(spec, sha1, 1, mode);
 509
 510         return;
 511 }
 512
 513 static void fill_line_ends(struct diff_filespec *spec, long *lines,
 514                            unsigned long **line_ends)
 515 {
 516         int num = 0, size = 50;
 517         long cur = 0;
 518         unsigned long *ends = NULL;
 519         char *data = NULL;
 520
 521         if (diff_populate_filespec(spec, 0))
 522                 die("Cannot read blob %s", oid_to_hex(&spec->oid));
 523
 524         ALLOC_ARRAY(ends, size);
 525         ends[cur++] = 0;
 526         data = spec->data;
 527         while (num < spec->size) {
 528                 if (data[num] == '\n' || num == spec->size - 1) {
 529                         ALLOC_GROW(ends, (cur + 1), size);
 530                         ends[cur++] = num;
 531                 }
 532                 num++;
 533         }
 534
 535         /* shrink the array to fit the elements */
 536         REALLOC_ARRAY(ends, cur);
 537         *lines = cur-1;
 538         *line_ends = ends;
 539 }
 540
 541 struct nth_line_cb {
 542         struct diff_filespec *spec;
 543         long lines;
 544         unsigned long *line_ends;
 545 };
 546
 547 static const char *nth_line(void *data, long line)
 548 {
 549         struct nth_line_cb *d = data;
 550         assert(d && line <= d->lines);
 551         assert(d->spec && d->spec->data);
 552
 553         if (line == 0)
 554                 return (char *)d->spec->data;
 555         else
 556                 return (char *)d->spec->data + d->line_ends[line] + 1;
 557 }
 558
 559 static struct line_log_data *
 560 parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 561 {
 562         long lines = 0;
 563         unsigned long *ends = NULL;
 564         struct nth_line_cb cb_data;
 565         struct string_list_item *item;
 566         struct line_log_data *ranges = NULL;
 567         struct line_log_data *p;
 568
 569         for_each_string_list_item(item, args) {
 570                 const char *name_part, *range_part;
 571                 char *full_name;
 572                 struct diff_filespec *spec;
 573                 long begin = 0, end = 0;
 574                 long anchor;
 575
 576                 name_part = skip_range_arg(item->string);
 577                 if (!name_part || *name_part != ':' || !name_part[1])
 578                         die("-L argument not 'start,end:file' or ':funcname:file': %s",
 579                             item->string);
 580                 range_part = xstrndup(item->string, name_part - item->string);
 581                 name_part++;
 582
 583                 full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
 584                                         name_part);
 585
 586                 spec = alloc_filespec(full_name);
 587                 fill_blob_sha1(commit, spec);
 588                 fill_line_ends(spec, &lines, &ends);
 589                 cb_data.spec = spec;
 590                 cb_data.lines = lines;
 591                 cb_data.line_ends = ends;
 592
 593                 p = search_line_log_data(ranges, full_name, NULL);
 594                 if (p && p->ranges.nr)
 595                         anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
 596                 else
 597                         anchor = 1;
 598
 599                 if (parse_range_arg(range_part, nth_line, &cb_data,
 600                                     lines, anchor, &begin, &end,
 601                                     full_name))
 602                         die("malformed -L argument '%s'", range_part);
 603                 if (lines < end || ((lines || begin) && lines < begin))
 604                         die("file %s has only %lu lines", name_part, lines);
 605                 if (begin < 1)
 606                         begin = 1;
 607                 if (end < 1)
 608                         end = lines;
 609                 begin--;
 610                 line_log_data_insert(&ranges, full_name, begin, end);
 611
 612                 free_filespec(spec);
 613                 FREE_AND_NULL(ends);
 614         }
 615
 616         for (p = ranges; p; p = p->next)
 617                 sort_and_merge_range_set(&p->ranges);
 618
 619         return ranges;
 620 }
 621
 622 static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 623 {
 624         struct line_log_data *ret = xmalloc(sizeof(*ret));
 625
 626         assert(r);
 627         line_log_data_init(ret);
 628         range_set_copy(&ret->ranges, &r->ranges);
 629
 630         ret->path = xstrdup(r->path);
 631
 632         return ret;
 633 }
 634
 635 static struct line_log_data *
 636 line_log_data_copy(struct line_log_data *r)
 637 {
 638         struct line_log_data *ret = NULL;
 639         struct line_log_data *tmp = NULL, *prev = NULL;
 640
 641         assert(r);
 642         ret = tmp = prev = line_log_data_copy_one(r);
 643         r = r->next;
 644         while (r) {
 645                 tmp = line_log_data_copy_one(r);
 646                 prev->next = tmp;
 647                 prev = tmp;
 648                 r = r->next;
 649         }
 650
 651         return ret;
 652 }
 653
 654 /* merge two range sets across files */
 655 static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 656                                                  struct line_log_data *b)
 657 {
 658         struct line_log_data *head = NULL, **pp = &head;
 659
 660         while (a || b) {
 661                 struct line_log_data *src;
 662                 struct line_log_data *src2 = NULL;
 663                 struct line_log_data *d;
 664                 int cmp;
 665                 if (!a)
 666                         cmp = 1;
 667                 else if (!b)
 668                         cmp = -1;
 669                 else
 670                         cmp = strcmp(a->path, b->path);
 671                 if (cmp < 0) {
 672                         src = a;
 673                         a = a->next;
 674                 } else if (cmp == 0) {
 675                         src = a;
 676                         a = a->next;
 677                         src2 = b;
 678                         b = b->next;
 679                 } else {
 680                         src = b;
 681                         b = b->next;
 682                 }
 683                 d = xmalloc(sizeof(struct line_log_data));
 684                 line_log_data_init(d);
 685                 d->path = xstrdup(src->path);
 686                 *pp = d;
 687                 pp = &d->next;
 688                 if (src2)
 689                         range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 690                 else
 691                         range_set_copy(&d->ranges, &src->ranges);
 692         }
 693
 694         return head;
 695 }
 696
 697 static void add_line_range(struct rev_info *revs, struct commit *commit,
 698                            struct line_log_data *range)
 699 {
 700         struct line_log_data *old = NULL;
 701         struct line_log_data *new = NULL;
 702
 703         old = lookup_decoration(&revs->line_log_data, &commit->object);
 704         if (old && range) {
 705                 new = line_log_data_merge(old, range);
 706                 free_line_log_data(old);
 707         } else if (range)
 708                 new = line_log_data_copy(range);
 709
 710         if (new)
 711                 add_decoration(&revs->line_log_data, &commit->object, new);
 712 }
 713
 714 static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 715 {
 716         struct line_log_data *r;
 717         r = lookup_decoration(&revs->line_log_data, &commit->object);
 718         if (!r)
 719                 return;
 720         free_line_log_data(r);
 721         add_decoration(&revs->line_log_data, &commit->object, NULL);
 722 }
 723
 724 static struct line_log_data *lookup_line_range(struct rev_info *revs,
 725                                                struct commit *commit)
 726 {
 727         struct line_log_data *ret = NULL;
 728         struct line_log_data *d;
 729
 730         ret = lookup_decoration(&revs->line_log_data, &commit->object);
 731
 732         for (d = ret; d; d = d->next)
 733                 range_set_check_invariants(&d->ranges);
 734
 735         return ret;
 736 }
 737
 738 void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 739 {
 740         struct commit *commit = NULL;
 741         struct line_log_data *range;
 742
 743         commit = check_single_commit(rev);
 744         range = parse_lines(commit, prefix, args);
 745         add_line_range(rev, commit, range);
 746
 747         if (!rev->diffopt.detect_rename) {
 748                 struct line_log_data *r;
 749                 struct argv_array array = ARGV_ARRAY_INIT;
 750                 const char **paths;
 751
 752                 for (r = range; r; r = r->next)
 753                         argv_array_push(&array, r->path);
 754                 paths = argv_array_detach(&array);
 755
 756                 parse_pathspec(&rev->diffopt.pathspec, 0,
 757                                PATHSPEC_PREFER_FULL, "", paths);
 758                 /* strings are now owned by pathspec */
 759                 free(paths);
 760         }
 761 }
 762
 763 static void move_diff_queue(struct diff_queue_struct *dst,
 764                             struct diff_queue_struct *src)
 765 {
 766         assert(src != dst);
 767         memcpy(dst, src, sizeof(struct diff_queue_struct));
 768         DIFF_QUEUE_CLEAR(src);
 769 }
 770
 771 static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 772 {
 773         int i;
 774         struct diff_queue_struct outq;
 775         DIFF_QUEUE_CLEAR(&outq);
 776
 777         for (i = 0; i < diff_queued_diff.nr; i++) {
 778                 struct diff_filepair *p = diff_queued_diff.queue[i];
 779                 struct line_log_data *rg = NULL;
 780
 781                 if (!DIFF_FILE_VALID(p->two)) {
 782                         if (keep_deletions)
 783                                 diff_q(&outq, p);
 784                         else
 785                                 diff_free_filepair(p);
 786                         continue;
 787                 }
 788                 for (rg = range; rg; rg = rg->next) {
 789                         if (!strcmp(rg->path, p->two->path))
 790                                 break;
 791                 }
 792                 if (rg)
 793                         diff_q(&outq, p);
 794                 else
 795                         diff_free_filepair(p);
 796         }
 797         free(diff_queued_diff.queue);
 798         diff_queued_diff = outq;
 799 }
 800
 801 static inline int diff_might_be_rename(void)
 802 {
 803         int i;
 804         for (i = 0; i < diff_queued_diff.nr; i++)
 805                 if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 806                         /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 807                         /*      diff_queued_diff.queue[i]->two->path); */
 808                         return 1;
 809                 }
 810         return 0;
 811 }
 812
 813 static void queue_diffs(struct line_log_data *range,
 814                         struct diff_options *opt,
 815                         struct diff_queue_struct *queue,
 816                         struct commit *commit, struct commit *parent)
 817 {
 818         assert(commit);
 819
 820         DIFF_QUEUE_CLEAR(&diff_queued_diff);
 821         diff_tree_sha1(parent ? parent->tree->object.oid.hash : NULL,
 822                         commit->tree->object.oid.hash, "", opt);
 823         if (opt->detect_rename) {
 824                 filter_diffs_for_paths(range, 1);
 825                 if (diff_might_be_rename())
 826                         diffcore_std(opt);
 827                 filter_diffs_for_paths(range, 0);
 828         }
 829         move_diff_queue(queue, &diff_queued_diff);
 830 }
 831
 832 static char *get_nth_line(long line, unsigned long *ends, void *data)
 833 {
 834         if (line == 0)
 835                 return (char *)data;
 836         else
 837                 return (char *)data + ends[line] + 1;
 838 }
 839
 840 static void print_line(const char *prefix, char first,
 841                        long line, unsigned long *ends, void *data,
 842                        const char *color, const char *reset, FILE *file)
 843 {
 844         char *begin = get_nth_line(line, ends, data);
 845         char *end = get_nth_line(line+1, ends, data);
 846         int had_nl = 0;
 847
 848         if (end > begin && end[-1] == '\n') {
 849                 end--;
 850                 had_nl = 1;
 851         }
 852
 853         fputs(prefix, file);
 854         fputs(color, file);
 855         putc(first, file);
 856         fwrite(begin, 1, end-begin, file);
 857         fputs(reset, file);
 858         putc('\n', file);
 859         if (!had_nl)
 860                 fputs("\\ No newline at end of file\n", file);
 861 }
 862
 863 static char *output_prefix(struct diff_options *opt)
 864 {
 865         char *prefix = "";
 866
 867         if (opt->output_prefix) {
 868                 struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 869                 prefix = sb->buf;
 870         }
 871
 872         return prefix;
 873 }
 874
 875 static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 876 {
 877         int i, j = 0;
 878         long p_lines, t_lines;
 879         unsigned long *p_ends = NULL, *t_ends = NULL;
 880         struct diff_filepair *pair = range->pair;
 881         struct diff_ranges *diff = &range->diff;
 882
 883         struct diff_options *opt = &rev->diffopt;
 884         char *prefix = output_prefix(opt);
 885         const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 886         const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 887         const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 888         const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 889         const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 890         const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 891
 892         if (!pair || !diff)
 893                 return;
 894
 895         if (pair->one->oid_valid)
 896                 fill_line_ends(pair->one, &p_lines, &p_ends);
 897         fill_line_ends(pair->two, &t_lines, &t_ends);
 898
 899         fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 900         fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 901                pair->one->oid_valid ? "a/" : "",
 902                pair->one->oid_valid ? pair->one->path : "/dev/null",
 903                c_reset);
 904         fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 905         for (i = 0; i < range->ranges.nr; i++) {
 906                 long p_start, p_end;
 907                 long t_start = range->ranges.ranges[i].start;
 908                 long t_end = range->ranges.ranges[i].end;
 909                 long t_cur = t_start;
 910                 int j_last;
 911
 912                 while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 913                         j++;
 914                 if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 915                         continue;
 916
 917                 /* Scan ahead to determine the last diff that falls in this range */
 918                 j_last = j;
 919                 while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 920                         j_last++;
 921                 if (j_last > j)
 922                         j_last--;
 923
 924                 /*
 925                  * Compute parent hunk headers: we know that the diff
 926                  * has the correct line numbers (but not all hunks).
 927                  * So it suffices to shift the start/end according to
 928                  * the line numbers of the first/last hunk(s) that
 929                  * fall in this range.
 930                  */
 931                 if (t_start < diff->target.ranges[j].start)
 932                         p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 933                 else
 934                         p_start = diff->parent.ranges[j].start;
 935                 if (t_end > diff->target.ranges[j_last].end)
 936                         p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 937                 else
 938                         p_end = diff->parent.ranges[j_last].end;
 939
 940                 if (!p_start && !p_end) {
 941                         p_start = -1;
 942                         p_end = -1;
 943                 }
 944
 945                 /* Now output a diff hunk for this range */
 946                 fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 947                        prefix, c_frag,
 948                        p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 949                        c_reset);
 950                 while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 951                         int k;
 952                         for (; t_cur < diff->target.ranges[j].start; t_cur++)
 953                                 print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 954                                            c_context, c_reset, opt->file);
 955                         for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 956                                 print_line(prefix, '-', k, p_ends, pair->one->data,
 957                                            c_old, c_reset, opt->file);
 958                         for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 959                                 print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 960                                            c_new, c_reset, opt->file);
 961                         j++;
 962                 }
 963                 for (; t_cur < t_end; t_cur++)
 964                         print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 965                                    c_context, c_reset, opt->file);
 966         }
 967
 968         free(p_ends);
 969         free(t_ends);
 970 }
 971
 972 /*
 973  * NEEDSWORK: manually building a diff here is not the Right
 974  * Thing(tm).  log -L should be built into the diff pipeline.
 975  */
 976 static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 977 {
 978         fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
 979         while (range) {
 980                 dump_diff_hacky_one(rev, range);
 981                 range = range->next;
 982         }
 983 }
 984
 985 /*
 986  * Unlike most other functions, this destructively operates on
 987  * 'range'.
 988  */
 989 static int process_diff_filepair(struct rev_info *rev,
 990                                  struct diff_filepair *pair,
 991                                  struct line_log_data *range,
 992                                  struct diff_ranges **diff_out)
 993 {
 994         struct line_log_data *rg = range;
 995         struct range_set tmp;
 996         struct diff_ranges diff;
 997         mmfile_t file_parent, file_target;
 998
 999         assert(pair->two->path);
1000         while (rg) {
1001                 assert(rg->path);
1002                 if (!strcmp(rg->path, pair->two->path))
1003                         break;
1004                 rg = rg->next;
1005         }
1006
1007         if (!rg)
1008                 return 0;
1009         if (rg->ranges.nr == 0)
1010                 return 0;
1011
1012         assert(pair->two->oid_valid);
1013         diff_populate_filespec(pair->two, 0);
1014         file_target.ptr = pair->two->data;
1015         file_target.size = pair->two->size;
1016
1017         if (pair->one->oid_valid) {
1018                 diff_populate_filespec(pair->one, 0);
1019                 file_parent.ptr = pair->one->data;
1020                 file_parent.size = pair->one->size;
1021         } else {
1022                 file_parent.ptr = "";
1023                 file_parent.size = 0;
1024         }
1025
1026         diff_ranges_init(&diff);
1027         if (collect_diff(&file_parent, &file_target, &diff))
1028                 die("unable to generate diff for %s", pair->one->path);
1029
1030         /* NEEDSWORK should apply some heuristics to prevent mismatches */
1031         free(rg->path);
1032         rg->path = xstrdup(pair->one->path);
1033
1034         range_set_init(&tmp, 0);
1035         range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1036         range_set_release(&rg->ranges);
1037         range_set_move(&rg->ranges, &tmp);
1038
1039         diff_ranges_release(&diff);
1040
1041         return ((*diff_out)->parent.nr > 0);
1042 }
1043
1044 static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1045 {
1046         struct diff_filepair *new = xmalloc(sizeof(struct diff_filepair));
1047         new->one = pair->one;
1048         new->two = pair->two;
1049         new->one->count++;
1050         new->two->count++;
1051         return new;
1052 }
1053
1054 static void free_diffqueues(int n, struct diff_queue_struct *dq)
1055 {
1056         int i, j;
1057         for (i = 0; i < n; i++)
1058                 for (j = 0; j < dq[i].nr; j++)
1059                         diff_free_filepair(dq[i].queue[j]);
1060         free(dq);
1061 }
1062
1063 static int process_all_files(struct line_log_data **range_out,
1064                              struct rev_info *rev,
1065                              struct diff_queue_struct *queue,
1066                              struct line_log_data *range)
1067 {
1068         int i, changed = 0;
1069
1070         *range_out = line_log_data_copy(range);
1071
1072         for (i = 0; i < queue->nr; i++) {
1073                 struct diff_ranges *pairdiff = NULL;
1074                 struct diff_filepair *pair = queue->queue[i];
1075                 if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1076                         /*
1077                          * Store away the diff for later output.  We
1078                          * tuck it in the ranges we got as _input_,
1079                          * since that's the commit that caused the
1080                          * diff.
1081                          *
1082                          * NEEDSWORK not enough when we get around to
1083                          * doing something interesting with merges;
1084                          * currently each invocation on a merge parent
1085                          * trashes the previous one's diff.
1086                          *
1087                          * NEEDSWORK tramples over data structures not owned here
1088                          */
1089                         struct line_log_data *rg = range;
1090                         changed++;
1091                         while (rg && strcmp(rg->path, pair->two->path))
1092                                 rg = rg->next;
1093                         assert(rg);
1094                         rg->pair = diff_filepair_dup(queue->queue[i]);
1095                         memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1096                 }
1097                 free(pairdiff);
1098         }
1099
1100         return changed;
1101 }
1102
1103 int line_log_print(struct rev_info *rev, struct commit *commit)
1104 {
1105         struct line_log_data *range = lookup_line_range(rev, commit);
1106
1107         show_log(rev);
1108         dump_diff_hacky(rev, range);
1109         return 1;
1110 }
1111
1112 static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1113                                           struct line_log_data *range)
1114 {
1115         struct commit *parent = NULL;
1116         struct diff_queue_struct queue;
1117         struct line_log_data *parent_range;
1118         int changed;
1119
1120         if (commit->parents)
1121                 parent = commit->parents->item;
1122
1123         queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1124         changed = process_all_files(&parent_range, rev, &queue, range);
1125         if (parent)
1126                 add_line_range(rev, parent, parent_range);
1127         free_line_log_data(parent_range);
1128         return changed;
1129 }
1130
1131 static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1132                                        struct line_log_data *range)
1133 {
1134         struct diff_queue_struct *diffqueues;
1135         struct line_log_data **cand;
1136         struct commit **parents;
1137         struct commit_list *p;
1138         int i;
1139         int nparents = commit_list_count(commit->parents);
1140
1141         if (nparents > 1 && rev->first_parent_only)
1142                 nparents = 1;
1143
1144         ALLOC_ARRAY(diffqueues, nparents);
1145         ALLOC_ARRAY(cand, nparents);
1146         ALLOC_ARRAY(parents, nparents);
1147
1148         p = commit->parents;
1149         for (i = 0; i < nparents; i++) {
1150                 parents[i] = p->item;
1151                 p = p->next;
1152                 queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1153         }
1154
1155         for (i = 0; i < nparents; i++) {
1156                 int changed;
1157                 cand[i] = NULL;
1158                 changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1159                 if (!changed) {
1160                         /*
1161                          * This parent can take all the blame, so we
1162                          * don't follow any other path in history
1163                          */
1164                         add_line_range(rev, parents[i], cand[i]);
1165                         clear_commit_line_range(rev, commit);
1166                         commit_list_append(parents[i], &commit->parents);
1167                         free(parents);
1168                         free(cand);
1169                         free_diffqueues(nparents, diffqueues);
1170                         /* NEEDSWORK leaking like a sieve */
1171                         return 0;
1172                 }
1173         }
1174
1175         /*
1176          * No single parent took the blame.  We add the candidates
1177          * from the above loop to the parents.
1178          */
1179         for (i = 0; i < nparents; i++) {
1180                 add_line_range(rev, parents[i], cand[i]);
1181         }
1182
1183         clear_commit_line_range(rev, commit);
1184         free(parents);
1185         free(cand);
1186         free_diffqueues(nparents, diffqueues);
1187         return 1;
1188
1189         /* NEEDSWORK evil merge detection stuff */
1190         /* NEEDSWORK leaking like a sieve */
1191 }
1192
1193 static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1194 {
1195         struct line_log_data *range = lookup_line_range(rev, commit);
1196         int changed = 0;
1197
1198         if (range) {
1199                 if (!commit->parents || !commit->parents->next)
1200                         changed = process_ranges_ordinary_commit(rev, commit, range);
1201                 else
1202                         changed = process_ranges_merge_commit(rev, commit, range);
1203         }
1204
1205         if (!changed)
1206                 commit->object.flags |= TREESAME;
1207
1208         return changed;
1209 }
1210
1211 static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1212 {
1213         for (;;) {
1214                 struct commit *p = *pp;
1215                 if (p->parents && p->parents->next)
1216                         return rewrite_one_ok;
1217                 if (p->object.flags & UNINTERESTING)
1218                         return rewrite_one_ok;
1219                 if (!(p->object.flags & TREESAME))
1220                         return rewrite_one_ok;
1221                 if (!p->parents)
1222                         return rewrite_one_noparents;
1223                 *pp = p->parents->item;
1224         }
1225 }
1226
1227 int line_log_filter(struct rev_info *rev)
1228 {
1229         struct commit *commit;
1230         struct commit_list *list = rev->commits;
1231         struct commit_list *out = NULL, **pp = &out;
1232
1233         while (list) {
1234                 struct commit_list *to_free = NULL;
1235                 commit = list->item;
1236                 if (process_ranges_arbitrary_commit(rev, commit)) {
1237                         *pp = list;
1238                         pp = &list->next;
1239                 } else
1240                         to_free = list;
1241                 list = list->next;
1242                 free(to_free);
1243         }
1244         *pp = NULL;
1245
1246         for (list = out; list; list = list->next)
1247                 rewrite_parents(rev, list->item, line_log_rewrite_one);
1248
1249         rev->commits = out;
1250
1251         return 0;
1252 }