line-log.con commit Merge branch 'ab/pcre-v2' (2f4af84)
   1#include "git-compat-util.h"
   2#include "line-range.h"
   3#include "cache.h"
   4#include "tag.h"
   5#include "blob.h"
   6#include "tree.h"
   7#include "diff.h"
   8#include "commit.h"
   9#include "decorate.h"
  10#include "revision.h"
  11#include "xdiff-interface.h"
  12#include "strbuf.h"
  13#include "log-tree.h"
  14#include "graph.h"
  15#include "userdiff.h"
  16#include "line-log.h"
  17#include "argv-array.h"
  18
  19static void range_set_grow(struct range_set *rs, size_t extra)
  20{
  21        ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
  22}
  23
  24/* Either initialization would be fine */
  25#define RANGE_SET_INIT {0}
  26
  27void range_set_init(struct range_set *rs, size_t prealloc)
  28{
  29        rs->alloc = rs->nr = 0;
  30        rs->ranges = NULL;
  31        if (prealloc)
  32                range_set_grow(rs, prealloc);
  33}
  34
  35void range_set_release(struct range_set *rs)
  36{
  37        free(rs->ranges);
  38        rs->alloc = rs->nr = 0;
  39        rs->ranges = NULL;
  40}
  41
  42/* dst must be uninitialized! */
  43static 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
  50static 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_ */
  61void 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
  70void 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
  76static 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 */
  92static 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 */
 112void 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 */
 145static 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 */
 187static 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
 229static 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
 235static void diff_ranges_release(struct diff_ranges *diff)
 236{
 237        range_set_release(&diff->parent);
 238        range_set_release(&diff->target);
 239}
 240
 241static 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
 247static 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
 254static 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
 264static struct line_log_data *
 265search_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 */
 286static 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
 311struct collect_diff_cbdata {
 312        struct diff_ranges *diff;
 313};
 314
 315static 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
 329static 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
 352static 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
 360static 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
 370static 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
 387static 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 */
 397static 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 */
 426static 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 */
 453static 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
 473static 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
 500static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
 501{
 502        unsigned mode;
 503        struct object_id oid;
 504
 505        if (get_tree_entry(commit->object.oid.hash, spec->path,
 506                           oid.hash, &mode))
 507                die("There is no path %s in the commit", spec->path);
 508        fill_filespec(spec, &oid, 1, mode);
 509
 510        return;
 511}
 512
 513static 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
 541struct nth_line_cb {
 542        struct diff_filespec *spec;
 543        long lines;
 544        unsigned long *line_ends;
 545};
 546
 547static 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
 559static struct line_log_data *
 560parse_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(ends);
 614                ends = NULL;
 615        }
 616
 617        for (p = ranges; p; p = p->next)
 618                sort_and_merge_range_set(&p->ranges);
 619
 620        return ranges;
 621}
 622
 623static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
 624{
 625        struct line_log_data *ret = xmalloc(sizeof(*ret));
 626
 627        assert(r);
 628        line_log_data_init(ret);
 629        range_set_copy(&ret->ranges, &r->ranges);
 630
 631        ret->path = xstrdup(r->path);
 632
 633        return ret;
 634}
 635
 636static struct line_log_data *
 637line_log_data_copy(struct line_log_data *r)
 638{
 639        struct line_log_data *ret = NULL;
 640        struct line_log_data *tmp = NULL, *prev = NULL;
 641
 642        assert(r);
 643        ret = tmp = prev = line_log_data_copy_one(r);
 644        r = r->next;
 645        while (r) {
 646                tmp = line_log_data_copy_one(r);
 647                prev->next = tmp;
 648                prev = tmp;
 649                r = r->next;
 650        }
 651
 652        return ret;
 653}
 654
 655/* merge two range sets across files */
 656static struct line_log_data *line_log_data_merge(struct line_log_data *a,
 657                                                 struct line_log_data *b)
 658{
 659        struct line_log_data *head = NULL, **pp = &head;
 660
 661        while (a || b) {
 662                struct line_log_data *src;
 663                struct line_log_data *src2 = NULL;
 664                struct line_log_data *d;
 665                int cmp;
 666                if (!a)
 667                        cmp = 1;
 668                else if (!b)
 669                        cmp = -1;
 670                else
 671                        cmp = strcmp(a->path, b->path);
 672                if (cmp < 0) {
 673                        src = a;
 674                        a = a->next;
 675                } else if (cmp == 0) {
 676                        src = a;
 677                        a = a->next;
 678                        src2 = b;
 679                        b = b->next;
 680                } else {
 681                        src = b;
 682                        b = b->next;
 683                }
 684                d = xmalloc(sizeof(struct line_log_data));
 685                line_log_data_init(d);
 686                d->path = xstrdup(src->path);
 687                *pp = d;
 688                pp = &d->next;
 689                if (src2)
 690                        range_set_union(&d->ranges, &src->ranges, &src2->ranges);
 691                else
 692                        range_set_copy(&d->ranges, &src->ranges);
 693        }
 694
 695        return head;
 696}
 697
 698static void add_line_range(struct rev_info *revs, struct commit *commit,
 699                           struct line_log_data *range)
 700{
 701        struct line_log_data *old = NULL;
 702        struct line_log_data *new = NULL;
 703
 704        old = lookup_decoration(&revs->line_log_data, &commit->object);
 705        if (old && range) {
 706                new = line_log_data_merge(old, range);
 707                free_line_log_data(old);
 708        } else if (range)
 709                new = line_log_data_copy(range);
 710
 711        if (new)
 712                add_decoration(&revs->line_log_data, &commit->object, new);
 713}
 714
 715static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
 716{
 717        struct line_log_data *r;
 718        r = lookup_decoration(&revs->line_log_data, &commit->object);
 719        if (!r)
 720                return;
 721        free_line_log_data(r);
 722        add_decoration(&revs->line_log_data, &commit->object, NULL);
 723}
 724
 725static struct line_log_data *lookup_line_range(struct rev_info *revs,
 726                                               struct commit *commit)
 727{
 728        struct line_log_data *ret = NULL;
 729        struct line_log_data *d;
 730
 731        ret = lookup_decoration(&revs->line_log_data, &commit->object);
 732
 733        for (d = ret; d; d = d->next)
 734                range_set_check_invariants(&d->ranges);
 735
 736        return ret;
 737}
 738
 739void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
 740{
 741        struct commit *commit = NULL;
 742        struct line_log_data *range;
 743
 744        commit = check_single_commit(rev);
 745        range = parse_lines(commit, prefix, args);
 746        add_line_range(rev, commit, range);
 747
 748        if (!rev->diffopt.detect_rename) {
 749                struct line_log_data *r;
 750                struct argv_array array = ARGV_ARRAY_INIT;
 751                const char **paths;
 752
 753                for (r = range; r; r = r->next)
 754                        argv_array_push(&array, r->path);
 755                paths = argv_array_detach(&array);
 756
 757                parse_pathspec(&rev->diffopt.pathspec, 0,
 758                               PATHSPEC_PREFER_FULL, "", paths);
 759                /* strings are now owned by pathspec */
 760                free(paths);
 761        }
 762}
 763
 764static void move_diff_queue(struct diff_queue_struct *dst,
 765                            struct diff_queue_struct *src)
 766{
 767        assert(src != dst);
 768        memcpy(dst, src, sizeof(struct diff_queue_struct));
 769        DIFF_QUEUE_CLEAR(src);
 770}
 771
 772static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
 773{
 774        int i;
 775        struct diff_queue_struct outq;
 776        DIFF_QUEUE_CLEAR(&outq);
 777
 778        for (i = 0; i < diff_queued_diff.nr; i++) {
 779                struct diff_filepair *p = diff_queued_diff.queue[i];
 780                struct line_log_data *rg = NULL;
 781
 782                if (!DIFF_FILE_VALID(p->two)) {
 783                        if (keep_deletions)
 784                                diff_q(&outq, p);
 785                        else
 786                                diff_free_filepair(p);
 787                        continue;
 788                }
 789                for (rg = range; rg; rg = rg->next) {
 790                        if (!strcmp(rg->path, p->two->path))
 791                                break;
 792                }
 793                if (rg)
 794                        diff_q(&outq, p);
 795                else
 796                        diff_free_filepair(p);
 797        }
 798        free(diff_queued_diff.queue);
 799        diff_queued_diff = outq;
 800}
 801
 802static inline int diff_might_be_rename(void)
 803{
 804        int i;
 805        for (i = 0; i < diff_queued_diff.nr; i++)
 806                if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
 807                        /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
 808                        /*      diff_queued_diff.queue[i]->two->path); */
 809                        return 1;
 810                }
 811        return 0;
 812}
 813
 814static void queue_diffs(struct line_log_data *range,
 815                        struct diff_options *opt,
 816                        struct diff_queue_struct *queue,
 817                        struct commit *commit, struct commit *parent)
 818{
 819        assert(commit);
 820
 821        DIFF_QUEUE_CLEAR(&diff_queued_diff);
 822        diff_tree_oid(parent ? &parent->tree->object.oid : NULL,
 823                      &commit->tree->object.oid, "", opt);
 824        if (opt->detect_rename) {
 825                filter_diffs_for_paths(range, 1);
 826                if (diff_might_be_rename())
 827                        diffcore_std(opt);
 828                filter_diffs_for_paths(range, 0);
 829        }
 830        move_diff_queue(queue, &diff_queued_diff);
 831}
 832
 833static char *get_nth_line(long line, unsigned long *ends, void *data)
 834{
 835        if (line == 0)
 836                return (char *)data;
 837        else
 838                return (char *)data + ends[line] + 1;
 839}
 840
 841static void print_line(const char *prefix, char first,
 842                       long line, unsigned long *ends, void *data,
 843                       const char *color, const char *reset, FILE *file)
 844{
 845        char *begin = get_nth_line(line, ends, data);
 846        char *end = get_nth_line(line+1, ends, data);
 847        int had_nl = 0;
 848
 849        if (end > begin && end[-1] == '\n') {
 850                end--;
 851                had_nl = 1;
 852        }
 853
 854        fputs(prefix, file);
 855        fputs(color, file);
 856        putc(first, file);
 857        fwrite(begin, 1, end-begin, file);
 858        fputs(reset, file);
 859        putc('\n', file);
 860        if (!had_nl)
 861                fputs("\\ No newline at end of file\n", file);
 862}
 863
 864static char *output_prefix(struct diff_options *opt)
 865{
 866        char *prefix = "";
 867
 868        if (opt->output_prefix) {
 869                struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
 870                prefix = sb->buf;
 871        }
 872
 873        return prefix;
 874}
 875
 876static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
 877{
 878        int i, j = 0;
 879        long p_lines, t_lines;
 880        unsigned long *p_ends = NULL, *t_ends = NULL;
 881        struct diff_filepair *pair = range->pair;
 882        struct diff_ranges *diff = &range->diff;
 883
 884        struct diff_options *opt = &rev->diffopt;
 885        char *prefix = output_prefix(opt);
 886        const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
 887        const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
 888        const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
 889        const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
 890        const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
 891        const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 892
 893        if (!pair || !diff)
 894                return;
 895
 896        if (pair->one->oid_valid)
 897                fill_line_ends(pair->one, &p_lines, &p_ends);
 898        fill_line_ends(pair->two, &t_lines, &t_ends);
 899
 900        fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
 901        fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 902               pair->one->oid_valid ? "a/" : "",
 903               pair->one->oid_valid ? pair->one->path : "/dev/null",
 904               c_reset);
 905        fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 906        for (i = 0; i < range->ranges.nr; i++) {
 907                long p_start, p_end;
 908                long t_start = range->ranges.ranges[i].start;
 909                long t_end = range->ranges.ranges[i].end;
 910                long t_cur = t_start;
 911                int j_last;
 912
 913                while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
 914                        j++;
 915                if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
 916                        continue;
 917
 918                /* Scan ahead to determine the last diff that falls in this range */
 919                j_last = j;
 920                while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
 921                        j_last++;
 922                if (j_last > j)
 923                        j_last--;
 924
 925                /*
 926                 * Compute parent hunk headers: we know that the diff
 927                 * has the correct line numbers (but not all hunks).
 928                 * So it suffices to shift the start/end according to
 929                 * the line numbers of the first/last hunk(s) that
 930                 * fall in this range.
 931                 */
 932                if (t_start < diff->target.ranges[j].start)
 933                        p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
 934                else
 935                        p_start = diff->parent.ranges[j].start;
 936                if (t_end > diff->target.ranges[j_last].end)
 937                        p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
 938                else
 939                        p_end = diff->parent.ranges[j_last].end;
 940
 941                if (!p_start && !p_end) {
 942                        p_start = -1;
 943                        p_end = -1;
 944                }
 945
 946                /* Now output a diff hunk for this range */
 947                fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 948                       prefix, c_frag,
 949                       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 950                       c_reset);
 951                while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
 952                        int k;
 953                        for (; t_cur < diff->target.ranges[j].start; t_cur++)
 954                                print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 955                                           c_context, c_reset, opt->file);
 956                        for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 957                                print_line(prefix, '-', k, p_ends, pair->one->data,
 958                                           c_old, c_reset, opt->file);
 959                        for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 960                                print_line(prefix, '+', t_cur, t_ends, pair->two->data,
 961                                           c_new, c_reset, opt->file);
 962                        j++;
 963                }
 964                for (; t_cur < t_end; t_cur++)
 965                        print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
 966                                   c_context, c_reset, opt->file);
 967        }
 968
 969        free(p_ends);
 970        free(t_ends);
 971}
 972
 973/*
 974 * NEEDSWORK: manually building a diff here is not the Right
 975 * Thing(tm).  log -L should be built into the diff pipeline.
 976 */
 977static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 978{
 979        fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
 980        while (range) {
 981                dump_diff_hacky_one(rev, range);
 982                range = range->next;
 983        }
 984}
 985
 986/*
 987 * Unlike most other functions, this destructively operates on
 988 * 'range'.
 989 */
 990static int process_diff_filepair(struct rev_info *rev,
 991                                 struct diff_filepair *pair,
 992                                 struct line_log_data *range,
 993                                 struct diff_ranges **diff_out)
 994{
 995        struct line_log_data *rg = range;
 996        struct range_set tmp;
 997        struct diff_ranges diff;
 998        mmfile_t file_parent, file_target;
 999
1000        assert(pair->two->path);
1001        while (rg) {
1002                assert(rg->path);
1003                if (!strcmp(rg->path, pair->two->path))
1004                        break;
1005                rg = rg->next;
1006        }
1007
1008        if (!rg)
1009                return 0;
1010        if (rg->ranges.nr == 0)
1011                return 0;
1012
1013        assert(pair->two->oid_valid);
1014        diff_populate_filespec(pair->two, 0);
1015        file_target.ptr = pair->two->data;
1016        file_target.size = pair->two->size;
1017
1018        if (pair->one->oid_valid) {
1019                diff_populate_filespec(pair->one, 0);
1020                file_parent.ptr = pair->one->data;
1021                file_parent.size = pair->one->size;
1022        } else {
1023                file_parent.ptr = "";
1024                file_parent.size = 0;
1025        }
1026
1027        diff_ranges_init(&diff);
1028        if (collect_diff(&file_parent, &file_target, &diff))
1029                die("unable to generate diff for %s", pair->one->path);
1030
1031        /* NEEDSWORK should apply some heuristics to prevent mismatches */
1032        free(rg->path);
1033        rg->path = xstrdup(pair->one->path);
1034
1035        range_set_init(&tmp, 0);
1036        range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1037        range_set_release(&rg->ranges);
1038        range_set_move(&rg->ranges, &tmp);
1039
1040        diff_ranges_release(&diff);
1041
1042        return ((*diff_out)->parent.nr > 0);
1043}
1044
1045static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1046{
1047        struct diff_filepair *new = xmalloc(sizeof(struct diff_filepair));
1048        new->one = pair->one;
1049        new->two = pair->two;
1050        new->one->count++;
1051        new->two->count++;
1052        return new;
1053}
1054
1055static void free_diffqueues(int n, struct diff_queue_struct *dq)
1056{
1057        int i, j;
1058        for (i = 0; i < n; i++)
1059                for (j = 0; j < dq[i].nr; j++)
1060                        diff_free_filepair(dq[i].queue[j]);
1061        free(dq);
1062}
1063
1064static int process_all_files(struct line_log_data **range_out,
1065                             struct rev_info *rev,
1066                             struct diff_queue_struct *queue,
1067                             struct line_log_data *range)
1068{
1069        int i, changed = 0;
1070
1071        *range_out = line_log_data_copy(range);
1072
1073        for (i = 0; i < queue->nr; i++) {
1074                struct diff_ranges *pairdiff = NULL;
1075                struct diff_filepair *pair = queue->queue[i];
1076                if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1077                        /*
1078                         * Store away the diff for later output.  We
1079                         * tuck it in the ranges we got as _input_,
1080                         * since that's the commit that caused the
1081                         * diff.
1082                         *
1083                         * NEEDSWORK not enough when we get around to
1084                         * doing something interesting with merges;
1085                         * currently each invocation on a merge parent
1086                         * trashes the previous one's diff.
1087                         *
1088                         * NEEDSWORK tramples over data structures not owned here
1089                         */
1090                        struct line_log_data *rg = range;
1091                        changed++;
1092                        while (rg && strcmp(rg->path, pair->two->path))
1093                                rg = rg->next;
1094                        assert(rg);
1095                        rg->pair = diff_filepair_dup(queue->queue[i]);
1096                        memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1097                }
1098                free(pairdiff);
1099        }
1100
1101        return changed;
1102}
1103
1104int line_log_print(struct rev_info *rev, struct commit *commit)
1105{
1106        struct line_log_data *range = lookup_line_range(rev, commit);
1107
1108        show_log(rev);
1109        dump_diff_hacky(rev, range);
1110        return 1;
1111}
1112
1113static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1114                                          struct line_log_data *range)
1115{
1116        struct commit *parent = NULL;
1117        struct diff_queue_struct queue;
1118        struct line_log_data *parent_range;
1119        int changed;
1120
1121        if (commit->parents)
1122                parent = commit->parents->item;
1123
1124        queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1125        changed = process_all_files(&parent_range, rev, &queue, range);
1126        if (parent)
1127                add_line_range(rev, parent, parent_range);
1128        free_line_log_data(parent_range);
1129        return changed;
1130}
1131
1132static 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
1194static 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
1212static 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
1228int 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}