combine-diff.con commit Merge branch 'sm/mv-dry-run-update' into maint (c9bc2c5)
   1#include "cache.h"
   2#include "commit.h"
   3#include "blob.h"
   4#include "diff.h"
   5#include "diffcore.h"
   6#include "quote.h"
   7#include "xdiff-interface.h"
   8#include "xdiff/xmacros.h"
   9#include "log-tree.h"
  10#include "refs.h"
  11#include "userdiff.h"
  12#include "sha1-array.h"
  13#include "revision.h"
  14
  15static int compare_paths(const struct combine_diff_path *one,
  16                          const struct diff_filespec *two)
  17{
  18        if (!S_ISDIR(one->mode) && !S_ISDIR(two->mode))
  19                return strcmp(one->path, two->path);
  20
  21        return base_name_compare(one->path, strlen(one->path), one->mode,
  22                                 two->path, strlen(two->path), two->mode);
  23}
  24
  25static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  26{
  27        struct diff_queue_struct *q = &diff_queued_diff;
  28        struct combine_diff_path *p, **tail = &curr;
  29        int i, cmp;
  30
  31        if (!n) {
  32                for (i = 0; i < q->nr; i++) {
  33                        int len;
  34                        const char *path;
  35                        if (diff_unmodified_pair(q->queue[i]))
  36                                continue;
  37                        path = q->queue[i]->two->path;
  38                        len = strlen(path);
  39                        p = xmalloc(combine_diff_path_size(num_parent, len));
  40                        p->path = (char *) &(p->parent[num_parent]);
  41                        memcpy(p->path, path, len);
  42                        p->path[len] = 0;
  43                        p->next = NULL;
  44                        memset(p->parent, 0,
  45                               sizeof(p->parent[0]) * num_parent);
  46
  47                        oidcpy(&p->oid, &q->queue[i]->two->oid);
  48                        p->mode = q->queue[i]->two->mode;
  49                        oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
  50                        p->parent[n].mode = q->queue[i]->one->mode;
  51                        p->parent[n].status = q->queue[i]->status;
  52                        *tail = p;
  53                        tail = &p->next;
  54                }
  55                return curr;
  56        }
  57
  58        /*
  59         * paths in curr (linked list) and q->queue[] (array) are
  60         * both sorted in the tree order.
  61         */
  62        i = 0;
  63        while ((p = *tail) != NULL) {
  64                cmp = ((i >= q->nr)
  65                       ? -1 : compare_paths(p, q->queue[i]->two));
  66
  67                if (cmp < 0) {
  68                        /* p->path not in q->queue[]; drop it */
  69                        *tail = p->next;
  70                        free(p);
  71                        continue;
  72                }
  73
  74                if (cmp > 0) {
  75                        /* q->queue[i] not in p->path; skip it */
  76                        i++;
  77                        continue;
  78                }
  79
  80                oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
  81                p->parent[n].mode = q->queue[i]->one->mode;
  82                p->parent[n].status = q->queue[i]->status;
  83
  84                tail = &p->next;
  85                i++;
  86        }
  87        return curr;
  88}
  89
  90/* Lines lost from parent */
  91struct lline {
  92        struct lline *next, *prev;
  93        int len;
  94        unsigned long parent_map;
  95        char line[FLEX_ARRAY];
  96};
  97
  98/* Lines lost from current parent (before coalescing) */
  99struct plost {
 100        struct lline *lost_head, *lost_tail;
 101        int len;
 102};
 103
 104/* Lines surviving in the merge result */
 105struct sline {
 106        /* Accumulated and coalesced lost lines */
 107        struct lline *lost;
 108        int lenlost;
 109        struct plost plost;
 110        char *bol;
 111        int len;
 112        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
 113         * we did not change it).
 114         * bit N is used for "interesting" lines, including context.
 115         * bit (N+1) is used for "do not show deletion before this".
 116         */
 117        unsigned long flag;
 118        unsigned long *p_lno;
 119};
 120
 121static int match_string_spaces(const char *line1, int len1,
 122                               const char *line2, int len2,
 123                               long flags)
 124{
 125        if (flags & XDF_WHITESPACE_FLAGS) {
 126                for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 127                for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 128        }
 129
 130        if (!(flags & (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)))
 131                return (len1 == len2 && !memcmp(line1, line2, len1));
 132
 133        while (len1 > 0 && len2 > 0) {
 134                len1--;
 135                len2--;
 136                if (XDL_ISSPACE(line1[len1]) || XDL_ISSPACE(line2[len2])) {
 137                        if ((flags & XDF_IGNORE_WHITESPACE_CHANGE) &&
 138                            (!XDL_ISSPACE(line1[len1]) || !XDL_ISSPACE(line2[len2])))
 139                                return 0;
 140
 141                        for (; len1 > 0 && XDL_ISSPACE(line1[len1]); len1--);
 142                        for (; len2 > 0 && XDL_ISSPACE(line2[len2]); len2--);
 143                }
 144                if (line1[len1] != line2[len2])
 145                        return 0;
 146        }
 147
 148        if (flags & XDF_IGNORE_WHITESPACE) {
 149                /* Consume remaining spaces */
 150                for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 151                for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 152        }
 153
 154        /* We matched full line1 and line2 */
 155        if (!len1 && !len2)
 156                return 1;
 157
 158        return 0;
 159}
 160
 161enum coalesce_direction { MATCH, BASE, NEW };
 162
 163/* Coalesce new lines into base by finding LCS */
 164static struct lline *coalesce_lines(struct lline *base, int *lenbase,
 165                                    struct lline *new, int lennew,
 166                                    unsigned long parent, long flags)
 167{
 168        int **lcs;
 169        enum coalesce_direction **directions;
 170        struct lline *baseend, *newend = NULL;
 171        int i, j, origbaselen = *lenbase;
 172
 173        if (new == NULL)
 174                return base;
 175
 176        if (base == NULL) {
 177                *lenbase = lennew;
 178                return new;
 179        }
 180
 181        /*
 182         * Coalesce new lines into base by finding the LCS
 183         * - Create the table to run dynamic programming
 184         * - Compute the LCS
 185         * - Then reverse read the direction structure:
 186         *   - If we have MATCH, assign parent to base flag, and consume
 187         *   both baseend and newend
 188         *   - Else if we have BASE, consume baseend
 189         *   - Else if we have NEW, insert newend lline into base and
 190         *   consume newend
 191         */
 192        lcs = xcalloc(st_add(origbaselen, 1), sizeof(int*));
 193        directions = xcalloc(st_add(origbaselen, 1), sizeof(enum coalesce_direction*));
 194        for (i = 0; i < origbaselen + 1; i++) {
 195                lcs[i] = xcalloc(st_add(lennew, 1), sizeof(int));
 196                directions[i] = xcalloc(st_add(lennew, 1), sizeof(enum coalesce_direction));
 197                directions[i][0] = BASE;
 198        }
 199        for (j = 1; j < lennew + 1; j++)
 200                directions[0][j] = NEW;
 201
 202        for (i = 1, baseend = base; i < origbaselen + 1; i++) {
 203                for (j = 1, newend = new; j < lennew + 1; j++) {
 204                        if (match_string_spaces(baseend->line, baseend->len,
 205                                                newend->line, newend->len, flags)) {
 206                                lcs[i][j] = lcs[i - 1][j - 1] + 1;
 207                                directions[i][j] = MATCH;
 208                        } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
 209                                lcs[i][j] = lcs[i][j - 1];
 210                                directions[i][j] = NEW;
 211                        } else {
 212                                lcs[i][j] = lcs[i - 1][j];
 213                                directions[i][j] = BASE;
 214                        }
 215                        if (newend->next)
 216                                newend = newend->next;
 217                }
 218                if (baseend->next)
 219                        baseend = baseend->next;
 220        }
 221
 222        for (i = 0; i < origbaselen + 1; i++)
 223                free(lcs[i]);
 224        free(lcs);
 225
 226        /* At this point, baseend and newend point to the end of each lists */
 227        i--;
 228        j--;
 229        while (i != 0 || j != 0) {
 230                if (directions[i][j] == MATCH) {
 231                        baseend->parent_map |= 1<<parent;
 232                        baseend = baseend->prev;
 233                        newend = newend->prev;
 234                        i--;
 235                        j--;
 236                } else if (directions[i][j] == NEW) {
 237                        struct lline *lline;
 238
 239                        lline = newend;
 240                        /* Remove lline from new list and update newend */
 241                        if (lline->prev)
 242                                lline->prev->next = lline->next;
 243                        else
 244                                new = lline->next;
 245                        if (lline->next)
 246                                lline->next->prev = lline->prev;
 247
 248                        newend = lline->prev;
 249                        j--;
 250
 251                        /* Add lline to base list */
 252                        if (baseend) {
 253                                lline->next = baseend->next;
 254                                lline->prev = baseend;
 255                                if (lline->prev)
 256                                        lline->prev->next = lline;
 257                        }
 258                        else {
 259                                lline->next = base;
 260                                base = lline;
 261                        }
 262                        (*lenbase)++;
 263
 264                        if (lline->next)
 265                                lline->next->prev = lline;
 266
 267                } else {
 268                        baseend = baseend->prev;
 269                        i--;
 270                }
 271        }
 272
 273        newend = new;
 274        while (newend) {
 275                struct lline *lline = newend;
 276                newend = newend->next;
 277                free(lline);
 278        }
 279
 280        for (i = 0; i < origbaselen + 1; i++)
 281                free(directions[i]);
 282        free(directions);
 283
 284        return base;
 285}
 286
 287static char *grab_blob(const struct object_id *oid, unsigned int mode,
 288                       unsigned long *size, struct userdiff_driver *textconv,
 289                       const char *path)
 290{
 291        char *blob;
 292        enum object_type type;
 293
 294        if (S_ISGITLINK(mode)) {
 295                struct strbuf buf = STRBUF_INIT;
 296                strbuf_addf(&buf, "Subproject commit %s\n", oid_to_hex(oid));
 297                *size = buf.len;
 298                blob = strbuf_detach(&buf, NULL);
 299        } else if (is_null_oid(oid)) {
 300                /* deleted blob */
 301                *size = 0;
 302                return xcalloc(1, 1);
 303        } else if (textconv) {
 304                struct diff_filespec *df = alloc_filespec(path);
 305                fill_filespec(df, oid, 1, mode);
 306                *size = fill_textconv(textconv, df, &blob);
 307                free_filespec(df);
 308        } else {
 309                blob = read_sha1_file(oid->hash, &type, size);
 310                if (type != OBJ_BLOB)
 311                        die("object '%s' is not a blob!", oid_to_hex(oid));
 312        }
 313        return blob;
 314}
 315
 316static void append_lost(struct sline *sline, int n, const char *line, int len)
 317{
 318        struct lline *lline;
 319        unsigned long this_mask = (1UL<<n);
 320        if (line[len-1] == '\n')
 321                len--;
 322
 323        FLEX_ALLOC_MEM(lline, line, line, len);
 324        lline->len = len;
 325        lline->next = NULL;
 326        lline->prev = sline->plost.lost_tail;
 327        if (lline->prev)
 328                lline->prev->next = lline;
 329        else
 330                sline->plost.lost_head = lline;
 331        sline->plost.lost_tail = lline;
 332        sline->plost.len++;
 333        lline->parent_map = this_mask;
 334}
 335
 336struct combine_diff_state {
 337        unsigned int lno;
 338        int ob, on, nb, nn;
 339        unsigned long nmask;
 340        int num_parent;
 341        int n;
 342        struct sline *sline;
 343        struct sline *lost_bucket;
 344};
 345
 346static void consume_line(void *state_, char *line, unsigned long len)
 347{
 348        struct combine_diff_state *state = state_;
 349        if (5 < len && !memcmp("@@ -", line, 4)) {
 350                if (parse_hunk_header(line, len,
 351                                      &state->ob, &state->on,
 352                                      &state->nb, &state->nn))
 353                        return;
 354                state->lno = state->nb;
 355                if (state->nn == 0) {
 356                        /* @@ -X,Y +N,0 @@ removed Y lines
 357                         * that would have come *after* line N
 358                         * in the result.  Our lost buckets hang
 359                         * to the line after the removed lines,
 360                         *
 361                         * Note that this is correct even when N == 0,
 362                         * in which case the hunk removes the first
 363                         * line in the file.
 364                         */
 365                        state->lost_bucket = &state->sline[state->nb];
 366                        if (!state->nb)
 367                                state->nb = 1;
 368                } else {
 369                        state->lost_bucket = &state->sline[state->nb-1];
 370                }
 371                if (!state->sline[state->nb-1].p_lno)
 372                        state->sline[state->nb-1].p_lno =
 373                                xcalloc(state->num_parent,
 374                                        sizeof(unsigned long));
 375                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 376                return;
 377        }
 378        if (!state->lost_bucket)
 379                return; /* not in any hunk yet */
 380        switch (line[0]) {
 381        case '-':
 382                append_lost(state->lost_bucket, state->n, line+1, len-1);
 383                break;
 384        case '+':
 385                state->sline[state->lno-1].flag |= state->nmask;
 386                state->lno++;
 387                break;
 388        }
 389}
 390
 391static void combine_diff(const struct object_id *parent, unsigned int mode,
 392                         mmfile_t *result_file,
 393                         struct sline *sline, unsigned int cnt, int n,
 394                         int num_parent, int result_deleted,
 395                         struct userdiff_driver *textconv,
 396                         const char *path, long flags)
 397{
 398        unsigned int p_lno, lno;
 399        unsigned long nmask = (1UL << n);
 400        xpparam_t xpp;
 401        xdemitconf_t xecfg;
 402        mmfile_t parent_file;
 403        struct combine_diff_state state;
 404        unsigned long sz;
 405
 406        if (result_deleted)
 407                return; /* result deleted */
 408
 409        parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
 410        parent_file.size = sz;
 411        memset(&xpp, 0, sizeof(xpp));
 412        xpp.flags = flags;
 413        memset(&xecfg, 0, sizeof(xecfg));
 414        memset(&state, 0, sizeof(state));
 415        state.nmask = nmask;
 416        state.sline = sline;
 417        state.lno = 1;
 418        state.num_parent = num_parent;
 419        state.n = n;
 420
 421        if (xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 422                          &xpp, &xecfg))
 423                die("unable to generate combined diff for %s",
 424                    oid_to_hex(parent));
 425        free(parent_file.ptr);
 426
 427        /* Assign line numbers for this parent.
 428         *
 429         * sline[lno].p_lno[n] records the first line number
 430         * (counting from 1) for parent N if the final hunk display
 431         * started by showing sline[lno] (possibly showing the lost
 432         * lines attached to it first).
 433         */
 434        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 435                struct lline *ll;
 436                sline[lno].p_lno[n] = p_lno;
 437
 438                /* Coalesce new lines */
 439                if (sline[lno].plost.lost_head) {
 440                        struct sline *sl = &sline[lno];
 441                        sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
 442                                                  sl->plost.lost_head,
 443                                                  sl->plost.len, n, flags);
 444                        sl->plost.lost_head = sl->plost.lost_tail = NULL;
 445                        sl->plost.len = 0;
 446                }
 447
 448                /* How many lines would this sline advance the p_lno? */
 449                ll = sline[lno].lost;
 450                while (ll) {
 451                        if (ll->parent_map & nmask)
 452                                p_lno++; /* '-' means parent had it */
 453                        ll = ll->next;
 454                }
 455                if (lno < cnt && !(sline[lno].flag & nmask))
 456                        p_lno++; /* no '+' means parent had it */
 457        }
 458        sline[lno].p_lno[n] = p_lno; /* trailer */
 459}
 460
 461static unsigned long context = 3;
 462static char combine_marker = '@';
 463
 464static int interesting(struct sline *sline, unsigned long all_mask)
 465{
 466        /* If some parents lost lines here, or if we have added to
 467         * some parent, it is interesting.
 468         */
 469        return ((sline->flag & all_mask) || sline->lost);
 470}
 471
 472static unsigned long adjust_hunk_tail(struct sline *sline,
 473                                      unsigned long all_mask,
 474                                      unsigned long hunk_begin,
 475                                      unsigned long i)
 476{
 477        /* i points at the first uninteresting line.  If the last line
 478         * of the hunk was interesting only because it has some
 479         * deletion, then it is not all that interesting for the
 480         * purpose of giving trailing context lines.  This is because
 481         * we output '-' line and then unmodified sline[i-1] itself in
 482         * that case which gives us one extra context line.
 483         */
 484        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 485                i--;
 486        return i;
 487}
 488
 489static unsigned long find_next(struct sline *sline,
 490                               unsigned long mark,
 491                               unsigned long i,
 492                               unsigned long cnt,
 493                               int look_for_uninteresting)
 494{
 495        /* We have examined up to i-1 and are about to look at i.
 496         * Find next interesting or uninteresting line.  Here,
 497         * "interesting" does not mean interesting(), but marked by
 498         * the give_context() function below (i.e. it includes context
 499         * lines that are not interesting to interesting() function
 500         * that are surrounded by interesting() ones.
 501         */
 502        while (i <= cnt)
 503                if (look_for_uninteresting
 504                    ? !(sline[i].flag & mark)
 505                    : (sline[i].flag & mark))
 506                        return i;
 507                else
 508                        i++;
 509        return i;
 510}
 511
 512static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 513{
 514        unsigned long all_mask = (1UL<<num_parent) - 1;
 515        unsigned long mark = (1UL<<num_parent);
 516        unsigned long no_pre_delete = (2UL<<num_parent);
 517        unsigned long i;
 518
 519        /* Two groups of interesting lines may have a short gap of
 520         * uninteresting lines.  Connect such groups to give them a
 521         * bit of context.
 522         *
 523         * We first start from what the interesting() function says,
 524         * and mark them with "mark", and paint context lines with the
 525         * mark.  So interesting() would still say false for such context
 526         * lines but they are treated as "interesting" in the end.
 527         */
 528        i = find_next(sline, mark, 0, cnt, 0);
 529        if (cnt < i)
 530                return 0;
 531
 532        while (i <= cnt) {
 533                unsigned long j = (context < i) ? (i - context) : 0;
 534                unsigned long k;
 535
 536                /* Paint a few lines before the first interesting line. */
 537                while (j < i) {
 538                        if (!(sline[j].flag & mark))
 539                                sline[j].flag |= no_pre_delete;
 540                        sline[j++].flag |= mark;
 541                }
 542
 543        again:
 544                /* we know up to i is to be included.  where does the
 545                 * next uninteresting one start?
 546                 */
 547                j = find_next(sline, mark, i, cnt, 1);
 548                if (cnt < j)
 549                        break; /* the rest are all interesting */
 550
 551                /* lookahead context lines */
 552                k = find_next(sline, mark, j, cnt, 0);
 553                j = adjust_hunk_tail(sline, all_mask, i, j);
 554
 555                if (k < j + context) {
 556                        /* k is interesting and [j,k) are not, but
 557                         * paint them interesting because the gap is small.
 558                         */
 559                        while (j < k)
 560                                sline[j++].flag |= mark;
 561                        i = k;
 562                        goto again;
 563                }
 564
 565                /* j is the first uninteresting line and there is
 566                 * no overlap beyond it within context lines.  Paint
 567                 * the trailing edge a bit.
 568                 */
 569                i = k;
 570                k = (j + context < cnt+1) ? j + context : cnt+1;
 571                while (j < k)
 572                        sline[j++].flag |= mark;
 573        }
 574        return 1;
 575}
 576
 577static int make_hunks(struct sline *sline, unsigned long cnt,
 578                       int num_parent, int dense)
 579{
 580        unsigned long all_mask = (1UL<<num_parent) - 1;
 581        unsigned long mark = (1UL<<num_parent);
 582        unsigned long i;
 583        int has_interesting = 0;
 584
 585        for (i = 0; i <= cnt; i++) {
 586                if (interesting(&sline[i], all_mask))
 587                        sline[i].flag |= mark;
 588                else
 589                        sline[i].flag &= ~mark;
 590        }
 591        if (!dense)
 592                return give_context(sline, cnt, num_parent);
 593
 594        /* Look at each hunk, and if we have changes from only one
 595         * parent, or the changes are the same from all but one
 596         * parent, mark that uninteresting.
 597         */
 598        i = 0;
 599        while (i <= cnt) {
 600                unsigned long j, hunk_begin, hunk_end;
 601                unsigned long same_diff;
 602                while (i <= cnt && !(sline[i].flag & mark))
 603                        i++;
 604                if (cnt < i)
 605                        break; /* No more interesting hunks */
 606                hunk_begin = i;
 607                for (j = i + 1; j <= cnt; j++) {
 608                        if (!(sline[j].flag & mark)) {
 609                                /* Look beyond the end to see if there
 610                                 * is an interesting line after this
 611                                 * hunk within context span.
 612                                 */
 613                                unsigned long la; /* lookahead */
 614                                int contin = 0;
 615                                la = adjust_hunk_tail(sline, all_mask,
 616                                                     hunk_begin, j);
 617                                la = (la + context < cnt + 1) ?
 618                                        (la + context) : cnt + 1;
 619                                while (la && j <= --la) {
 620                                        if (sline[la].flag & mark) {
 621                                                contin = 1;
 622                                                break;
 623                                        }
 624                                }
 625                                if (!contin)
 626                                        break;
 627                                j = la;
 628                        }
 629                }
 630                hunk_end = j;
 631
 632                /* [i..hunk_end) are interesting.  Now is it really
 633                 * interesting?  We check if there are only two versions
 634                 * and the result matches one of them.  That is, we look
 635                 * at:
 636                 *   (+) line, which records lines added to which parents;
 637                 *       this line appears in the result.
 638                 *   (-) line, which records from what parents the line
 639                 *       was removed; this line does not appear in the result.
 640                 * then check the set of parents the result has difference
 641                 * from, from all lines.  If there are lines that has
 642                 * different set of parents that the result has differences
 643                 * from, that means we have more than two versions.
 644                 *
 645                 * Even when we have only two versions, if the result does
 646                 * not match any of the parents, the it should be considered
 647                 * interesting.  In such a case, we would have all '+' line.
 648                 * After passing the above "two versions" test, that would
 649                 * appear as "the same set of parents" to be "all parents".
 650                 */
 651                same_diff = 0;
 652                has_interesting = 0;
 653                for (j = i; j < hunk_end && !has_interesting; j++) {
 654                        unsigned long this_diff = sline[j].flag & all_mask;
 655                        struct lline *ll = sline[j].lost;
 656                        if (this_diff) {
 657                                /* This has some changes.  Is it the
 658                                 * same as others?
 659                                 */
 660                                if (!same_diff)
 661                                        same_diff = this_diff;
 662                                else if (same_diff != this_diff) {
 663                                        has_interesting = 1;
 664                                        break;
 665                                }
 666                        }
 667                        while (ll && !has_interesting) {
 668                                /* Lost this line from these parents;
 669                                 * who are they?  Are they the same?
 670                                 */
 671                                this_diff = ll->parent_map;
 672                                if (!same_diff)
 673                                        same_diff = this_diff;
 674                                else if (same_diff != this_diff) {
 675                                        has_interesting = 1;
 676                                }
 677                                ll = ll->next;
 678                        }
 679                }
 680
 681                if (!has_interesting && same_diff != all_mask) {
 682                        /* This hunk is not that interesting after all */
 683                        for (j = hunk_begin; j < hunk_end; j++)
 684                                sline[j].flag &= ~mark;
 685                }
 686                i = hunk_end;
 687        }
 688
 689        has_interesting = give_context(sline, cnt, num_parent);
 690        return has_interesting;
 691}
 692
 693static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 694{
 695        l0 = sline[l0].p_lno[n];
 696        l1 = sline[l1].p_lno[n];
 697        printf(" -%lu,%lu", l0, l1-l0-null_context);
 698}
 699
 700static int hunk_comment_line(const char *bol)
 701{
 702        int ch;
 703
 704        if (!bol)
 705                return 0;
 706        ch = *bol & 0xff;
 707        return (isalpha(ch) || ch == '_' || ch == '$');
 708}
 709
 710static void show_line_to_eol(const char *line, int len, const char *reset)
 711{
 712        int saw_cr_at_eol = 0;
 713        if (len < 0)
 714                len = strlen(line);
 715        saw_cr_at_eol = (len && line[len-1] == '\r');
 716
 717        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 718               reset,
 719               saw_cr_at_eol ? "\r" : "");
 720}
 721
 722static void dump_sline(struct sline *sline, const char *line_prefix,
 723                       unsigned long cnt, int num_parent,
 724                       int use_color, int result_deleted)
 725{
 726        unsigned long mark = (1UL<<num_parent);
 727        unsigned long no_pre_delete = (2UL<<num_parent);
 728        int i;
 729        unsigned long lno = 0;
 730        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 731        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 732        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 733        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 734        const char *c_context = diff_get_color(use_color, DIFF_CONTEXT);
 735        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 736
 737        if (result_deleted)
 738                return; /* result deleted */
 739
 740        while (1) {
 741                unsigned long hunk_end;
 742                unsigned long rlines;
 743                const char *hunk_comment = NULL;
 744                unsigned long null_context = 0;
 745
 746                while (lno <= cnt && !(sline[lno].flag & mark)) {
 747                        if (hunk_comment_line(sline[lno].bol))
 748                                hunk_comment = sline[lno].bol;
 749                        lno++;
 750                }
 751                if (cnt < lno)
 752                        break;
 753                else {
 754                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 755                                if (!(sline[hunk_end].flag & mark))
 756                                        break;
 757                }
 758                rlines = hunk_end - lno;
 759                if (cnt < hunk_end)
 760                        rlines--; /* pointing at the last delete hunk */
 761
 762                if (!context) {
 763                        /*
 764                         * Even when running with --unified=0, all
 765                         * lines in the hunk needs to be processed in
 766                         * the loop below in order to show the
 767                         * deletion recorded in lost_head.  However,
 768                         * we do not want to show the resulting line
 769                         * with all blank context markers in such a
 770                         * case.  Compensate.
 771                         */
 772                        unsigned long j;
 773                        for (j = lno; j < hunk_end; j++)
 774                                if (!(sline[j].flag & (mark-1)))
 775                                        null_context++;
 776                        rlines -= null_context;
 777                }
 778
 779                printf("%s%s", line_prefix, c_frag);
 780                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 781                for (i = 0; i < num_parent; i++)
 782                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 783                printf(" +%lu,%lu ", lno+1, rlines);
 784                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 785
 786                if (hunk_comment) {
 787                        int comment_end = 0;
 788                        for (i = 0; i < 40; i++) {
 789                                int ch = hunk_comment[i] & 0xff;
 790                                if (!ch || ch == '\n')
 791                                        break;
 792                                if (!isspace(ch))
 793                                    comment_end = i;
 794                        }
 795                        if (comment_end)
 796                                printf("%s%s %s%s", c_reset,
 797                                                    c_context, c_reset,
 798                                                    c_func);
 799                        for (i = 0; i < comment_end; i++)
 800                                putchar(hunk_comment[i]);
 801                }
 802
 803                printf("%s\n", c_reset);
 804                while (lno < hunk_end) {
 805                        struct lline *ll;
 806                        int j;
 807                        unsigned long p_mask;
 808                        struct sline *sl = &sline[lno++];
 809                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
 810                        while (ll) {
 811                                printf("%s%s", line_prefix, c_old);
 812                                for (j = 0; j < num_parent; j++) {
 813                                        if (ll->parent_map & (1UL<<j))
 814                                                putchar('-');
 815                                        else
 816                                                putchar(' ');
 817                                }
 818                                show_line_to_eol(ll->line, -1, c_reset);
 819                                ll = ll->next;
 820                        }
 821                        if (cnt < lno)
 822                                break;
 823                        p_mask = 1;
 824                        fputs(line_prefix, stdout);
 825                        if (!(sl->flag & (mark-1))) {
 826                                /*
 827                                 * This sline was here to hang the
 828                                 * lost lines in front of it.
 829                                 */
 830                                if (!context)
 831                                        continue;
 832                                fputs(c_context, stdout);
 833                        }
 834                        else
 835                                fputs(c_new, stdout);
 836                        for (j = 0; j < num_parent; j++) {
 837                                if (p_mask & sl->flag)
 838                                        putchar('+');
 839                                else
 840                                        putchar(' ');
 841                                p_mask <<= 1;
 842                        }
 843                        show_line_to_eol(sl->bol, sl->len, c_reset);
 844                }
 845        }
 846}
 847
 848static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 849                               int i, int j)
 850{
 851        /* We have already examined parent j and we know parent i
 852         * and parent j are the same, so reuse the combined result
 853         * of parent j for parent i.
 854         */
 855        unsigned long lno, imask, jmask;
 856        imask = (1UL<<i);
 857        jmask = (1UL<<j);
 858
 859        for (lno = 0; lno <= cnt; lno++) {
 860                struct lline *ll = sline->lost;
 861                sline->p_lno[i] = sline->p_lno[j];
 862                while (ll) {
 863                        if (ll->parent_map & jmask)
 864                                ll->parent_map |= imask;
 865                        ll = ll->next;
 866                }
 867                if (sline->flag & jmask)
 868                        sline->flag |= imask;
 869                sline++;
 870        }
 871        /* the overall size of the file (sline[cnt]) */
 872        sline->p_lno[i] = sline->p_lno[j];
 873}
 874
 875static void dump_quoted_path(const char *head,
 876                             const char *prefix,
 877                             const char *path,
 878                             const char *line_prefix,
 879                             const char *c_meta, const char *c_reset)
 880{
 881        static struct strbuf buf = STRBUF_INIT;
 882
 883        strbuf_reset(&buf);
 884        strbuf_addstr(&buf, line_prefix);
 885        strbuf_addstr(&buf, c_meta);
 886        strbuf_addstr(&buf, head);
 887        quote_two_c_style(&buf, prefix, path, 0);
 888        strbuf_addstr(&buf, c_reset);
 889        puts(buf.buf);
 890}
 891
 892static void show_combined_header(struct combine_diff_path *elem,
 893                                 int num_parent,
 894                                 int dense,
 895                                 struct rev_info *rev,
 896                                 const char *line_prefix,
 897                                 int mode_differs,
 898                                 int show_file_header)
 899{
 900        struct diff_options *opt = &rev->diffopt;
 901        int abbrev = opt->flags.full_index ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
 902        const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 903        const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 904        const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 905        const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 906        const char *abb;
 907        int added = 0;
 908        int deleted = 0;
 909        int i;
 910
 911        if (rev->loginfo && !rev->no_commit_id)
 912                show_log(rev);
 913
 914        dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 915                         "", elem->path, line_prefix, c_meta, c_reset);
 916        printf("%s%sindex ", line_prefix, c_meta);
 917        for (i = 0; i < num_parent; i++) {
 918                abb = find_unique_abbrev(elem->parent[i].oid.hash,
 919                                         abbrev);
 920                printf("%s%s", i ? "," : "", abb);
 921        }
 922        abb = find_unique_abbrev(elem->oid.hash, abbrev);
 923        printf("..%s%s\n", abb, c_reset);
 924
 925        if (mode_differs) {
 926                deleted = !elem->mode;
 927
 928                /* We say it was added if nobody had it */
 929                added = !deleted;
 930                for (i = 0; added && i < num_parent; i++)
 931                        if (elem->parent[i].status !=
 932                            DIFF_STATUS_ADDED)
 933                                added = 0;
 934                if (added)
 935                        printf("%s%snew file mode %06o",
 936                               line_prefix, c_meta, elem->mode);
 937                else {
 938                        if (deleted)
 939                                printf("%s%sdeleted file ",
 940                                       line_prefix, c_meta);
 941                        printf("mode ");
 942                        for (i = 0; i < num_parent; i++) {
 943                                printf("%s%06o", i ? "," : "",
 944                                       elem->parent[i].mode);
 945                        }
 946                        if (elem->mode)
 947                                printf("..%06o", elem->mode);
 948                }
 949                printf("%s\n", c_reset);
 950        }
 951
 952        if (!show_file_header)
 953                return;
 954
 955        if (added)
 956                dump_quoted_path("--- ", "", "/dev/null",
 957                                 line_prefix, c_meta, c_reset);
 958        else
 959                dump_quoted_path("--- ", a_prefix, elem->path,
 960                                 line_prefix, c_meta, c_reset);
 961        if (deleted)
 962                dump_quoted_path("+++ ", "", "/dev/null",
 963                                 line_prefix, c_meta, c_reset);
 964        else
 965                dump_quoted_path("+++ ", b_prefix, elem->path,
 966                                 line_prefix, c_meta, c_reset);
 967}
 968
 969static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 970                            int dense, int working_tree_file,
 971                            struct rev_info *rev)
 972{
 973        struct diff_options *opt = &rev->diffopt;
 974        unsigned long result_size, cnt, lno;
 975        int result_deleted = 0;
 976        char *result, *cp;
 977        struct sline *sline; /* survived lines */
 978        int mode_differs = 0;
 979        int i, show_hunks;
 980        mmfile_t result_file;
 981        struct userdiff_driver *userdiff;
 982        struct userdiff_driver *textconv = NULL;
 983        int is_binary;
 984        const char *line_prefix = diff_line_prefix(opt);
 985
 986        context = opt->context;
 987        userdiff = userdiff_find_by_path(elem->path);
 988        if (!userdiff)
 989                userdiff = userdiff_find_by_name("default");
 990        if (opt->flags.allow_textconv)
 991                textconv = userdiff_get_textconv(userdiff);
 992
 993        /* Read the result of merge first */
 994        if (!working_tree_file)
 995                result = grab_blob(&elem->oid, elem->mode, &result_size,
 996                                   textconv, elem->path);
 997        else {
 998                /* Used by diff-tree to read from the working tree */
 999                struct stat st;
1000                int fd = -1;
1001
1002                if (lstat(elem->path, &st) < 0)
1003                        goto deleted_file;
1004
1005                if (S_ISLNK(st.st_mode)) {
1006                        struct strbuf buf = STRBUF_INIT;
1007
1008                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
1009                                error_errno("readlink(%s)", elem->path);
1010                                return;
1011                        }
1012                        result_size = buf.len;
1013                        result = strbuf_detach(&buf, NULL);
1014                        elem->mode = canon_mode(st.st_mode);
1015                } else if (S_ISDIR(st.st_mode)) {
1016                        struct object_id oid;
1017                        if (resolve_gitlink_ref(elem->path, "HEAD", &oid) < 0)
1018                                result = grab_blob(&elem->oid, elem->mode,
1019                                                   &result_size, NULL, NULL);
1020                        else
1021                                result = grab_blob(&oid, elem->mode,
1022                                                   &result_size, NULL, NULL);
1023                } else if (textconv) {
1024                        struct diff_filespec *df = alloc_filespec(elem->path);
1025                        fill_filespec(df, &null_oid, 0, st.st_mode);
1026                        result_size = fill_textconv(textconv, df, &result);
1027                        free_filespec(df);
1028                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
1029                        size_t len = xsize_t(st.st_size);
1030                        ssize_t done;
1031                        int is_file, i;
1032
1033                        elem->mode = canon_mode(st.st_mode);
1034                        /* if symlinks don't work, assume symlink if all parents
1035                         * are symlinks
1036                         */
1037                        is_file = has_symlinks;
1038                        for (i = 0; !is_file && i < num_parent; i++)
1039                                is_file = !S_ISLNK(elem->parent[i].mode);
1040                        if (!is_file)
1041                                elem->mode = canon_mode(S_IFLNK);
1042
1043                        result_size = len;
1044                        result = xmallocz(len);
1045
1046                        done = read_in_full(fd, result, len);
1047                        if (done < 0)
1048                                die_errno("read error '%s'", elem->path);
1049                        else if (done < len)
1050                                die("early EOF '%s'", elem->path);
1051
1052                        /* If not a fake symlink, apply filters, e.g. autocrlf */
1053                        if (is_file) {
1054                                struct strbuf buf = STRBUF_INIT;
1055
1056                                if (convert_to_git(&the_index, elem->path, result, len, &buf, safe_crlf)) {
1057                                        free(result);
1058                                        result = strbuf_detach(&buf, &len);
1059                                        result_size = len;
1060                                }
1061                        }
1062                }
1063                else {
1064                deleted_file:
1065                        result_deleted = 1;
1066                        result_size = 0;
1067                        elem->mode = 0;
1068                        result = xcalloc(1, 1);
1069                }
1070
1071                if (0 <= fd)
1072                        close(fd);
1073        }
1074
1075        for (i = 0; i < num_parent; i++) {
1076                if (elem->parent[i].mode != elem->mode) {
1077                        mode_differs = 1;
1078                        break;
1079                }
1080        }
1081
1082        if (textconv)
1083                is_binary = 0;
1084        else if (userdiff->binary != -1)
1085                is_binary = userdiff->binary;
1086        else {
1087                is_binary = buffer_is_binary(result, result_size);
1088                for (i = 0; !is_binary && i < num_parent; i++) {
1089                        char *buf;
1090                        unsigned long size;
1091                        buf = grab_blob(&elem->parent[i].oid,
1092                                        elem->parent[i].mode,
1093                                        &size, NULL, NULL);
1094                        if (buffer_is_binary(buf, size))
1095                                is_binary = 1;
1096                        free(buf);
1097                }
1098        }
1099        if (is_binary) {
1100                show_combined_header(elem, num_parent, dense, rev,
1101                                     line_prefix, mode_differs, 0);
1102                printf("Binary files differ\n");
1103                free(result);
1104                return;
1105        }
1106
1107        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
1108                if (*cp == '\n')
1109                        cnt++;
1110        }
1111        if (result_size && result[result_size-1] != '\n')
1112                cnt++; /* incomplete line */
1113
1114        sline = xcalloc(st_add(cnt, 2), sizeof(*sline));
1115        sline[0].bol = result;
1116        for (lno = 0, cp = result; cp < result + result_size; cp++) {
1117                if (*cp == '\n') {
1118                        sline[lno].len = cp - sline[lno].bol;
1119                        lno++;
1120                        if (lno < cnt)
1121                                sline[lno].bol = cp + 1;
1122                }
1123        }
1124        if (result_size && result[result_size-1] != '\n')
1125                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
1126
1127        result_file.ptr = result;
1128        result_file.size = result_size;
1129
1130        /* Even p_lno[cnt+1] is valid -- that is for the end line number
1131         * for deletion hunk at the end.
1132         */
1133        sline[0].p_lno = xcalloc(st_mult(st_add(cnt, 2), num_parent), sizeof(unsigned long));
1134        for (lno = 0; lno <= cnt; lno++)
1135                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
1136
1137        for (i = 0; i < num_parent; i++) {
1138                int j;
1139                for (j = 0; j < i; j++) {
1140                        if (!oidcmp(&elem->parent[i].oid,
1141                                     &elem->parent[j].oid)) {
1142                                reuse_combine_diff(sline, cnt, i, j);
1143                                break;
1144                        }
1145                }
1146                if (i <= j)
1147                        combine_diff(&elem->parent[i].oid,
1148                                     elem->parent[i].mode,
1149                                     &result_file, sline,
1150                                     cnt, i, num_parent, result_deleted,
1151                                     textconv, elem->path, opt->xdl_opts);
1152        }
1153
1154        show_hunks = make_hunks(sline, cnt, num_parent, dense);
1155
1156        if (show_hunks || mode_differs || working_tree_file) {
1157                show_combined_header(elem, num_parent, dense, rev,
1158                                     line_prefix, mode_differs, 1);
1159                dump_sline(sline, line_prefix, cnt, num_parent,
1160                           opt->use_color, result_deleted);
1161        }
1162        free(result);
1163
1164        for (lno = 0; lno < cnt; lno++) {
1165                if (sline[lno].lost) {
1166                        struct lline *ll = sline[lno].lost;
1167                        while (ll) {
1168                                struct lline *tmp = ll;
1169                                ll = ll->next;
1170                                free(tmp);
1171                        }
1172                }
1173        }
1174        free(sline[0].p_lno);
1175        free(sline);
1176}
1177
1178static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
1179{
1180        struct diff_options *opt = &rev->diffopt;
1181        int line_termination, inter_name_termination, i;
1182        const char *line_prefix = diff_line_prefix(opt);
1183
1184        line_termination = opt->line_termination;
1185        inter_name_termination = '\t';
1186        if (!line_termination)
1187                inter_name_termination = 0;
1188
1189        if (rev->loginfo && !rev->no_commit_id)
1190                show_log(rev);
1191
1192
1193        if (opt->output_format & DIFF_FORMAT_RAW) {
1194                printf("%s", line_prefix);
1195
1196                /* As many colons as there are parents */
1197                for (i = 0; i < num_parent; i++)
1198                        putchar(':');
1199
1200                /* Show the modes */
1201                for (i = 0; i < num_parent; i++)
1202                        printf("%06o ", p->parent[i].mode);
1203                printf("%06o", p->mode);
1204
1205                /* Show sha1's */
1206                for (i = 0; i < num_parent; i++)
1207                        printf(" %s", diff_aligned_abbrev(&p->parent[i].oid,
1208                                                          opt->abbrev));
1209                printf(" %s ", diff_aligned_abbrev(&p->oid, opt->abbrev));
1210        }
1211
1212        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1213                for (i = 0; i < num_parent; i++)
1214                        putchar(p->parent[i].status);
1215                putchar(inter_name_termination);
1216        }
1217
1218        write_name_quoted(p->path, stdout, line_termination);
1219}
1220
1221/*
1222 * The result (p->elem) is from the working tree and their
1223 * parents are typically from multiple stages during a merge
1224 * (i.e. diff-files) or the state in HEAD and in the index
1225 * (i.e. diff-index).
1226 */
1227void show_combined_diff(struct combine_diff_path *p,
1228                       int num_parent,
1229                       int dense,
1230                       struct rev_info *rev)
1231{
1232        struct diff_options *opt = &rev->diffopt;
1233
1234        if (opt->output_format & (DIFF_FORMAT_RAW |
1235                                  DIFF_FORMAT_NAME |
1236                                  DIFF_FORMAT_NAME_STATUS))
1237                show_raw_diff(p, num_parent, rev);
1238        else if (opt->output_format & DIFF_FORMAT_PATCH)
1239                show_patch_diff(p, num_parent, dense, 1, rev);
1240}
1241
1242static void free_combined_pair(struct diff_filepair *pair)
1243{
1244        free(pair->two);
1245        free(pair);
1246}
1247
1248/*
1249 * A combine_diff_path expresses N parents on the LHS against 1 merge
1250 * result. Synthesize a diff_filepair that has N entries on the "one"
1251 * side and 1 entry on the "two" side.
1252 *
1253 * In the future, we might want to add more data to combine_diff_path
1254 * so that we can fill fields we are ignoring (most notably, size) here,
1255 * but currently nobody uses it, so this should suffice for now.
1256 */
1257static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1258                                           int num_parent)
1259{
1260        int i;
1261        struct diff_filepair *pair;
1262        struct diff_filespec *pool;
1263
1264        pair = xmalloc(sizeof(*pair));
1265        pool = xcalloc(st_add(num_parent, 1), sizeof(struct diff_filespec));
1266        pair->one = pool + 1;
1267        pair->two = pool;
1268
1269        for (i = 0; i < num_parent; i++) {
1270                pair->one[i].path = p->path;
1271                pair->one[i].mode = p->parent[i].mode;
1272                oidcpy(&pair->one[i].oid, &p->parent[i].oid);
1273                pair->one[i].oid_valid = !is_null_oid(&p->parent[i].oid);
1274                pair->one[i].has_more_entries = 1;
1275        }
1276        pair->one[num_parent - 1].has_more_entries = 0;
1277
1278        pair->two->path = p->path;
1279        pair->two->mode = p->mode;
1280        oidcpy(&pair->two->oid, &p->oid);
1281        pair->two->oid_valid = !is_null_oid(&p->oid);
1282        return pair;
1283}
1284
1285static void handle_combined_callback(struct diff_options *opt,
1286                                     struct combine_diff_path *paths,
1287                                     int num_parent,
1288                                     int num_paths)
1289{
1290        struct combine_diff_path *p;
1291        struct diff_queue_struct q;
1292        int i;
1293
1294        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1295        q.alloc = num_paths;
1296        q.nr = num_paths;
1297        for (i = 0, p = paths; p; p = p->next)
1298                q.queue[i++] = combined_pair(p, num_parent);
1299        opt->format_callback(&q, opt, opt->format_callback_data);
1300        for (i = 0; i < num_paths; i++)
1301                free_combined_pair(q.queue[i]);
1302        free(q.queue);
1303}
1304
1305static const char *path_path(void *obj)
1306{
1307        struct combine_diff_path *path = (struct combine_diff_path *)obj;
1308
1309        return path->path;
1310}
1311
1312
1313/* find set of paths that every parent touches */
1314static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
1315        const struct oid_array *parents, struct diff_options *opt)
1316{
1317        struct combine_diff_path *paths = NULL;
1318        int i, num_parent = parents->nr;
1319
1320        int output_format = opt->output_format;
1321        const char *orderfile = opt->orderfile;
1322
1323        opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1324        /* tell diff_tree to emit paths in sorted (=tree) order */
1325        opt->orderfile = NULL;
1326
1327        /* D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn)  (wrt paths) */
1328        for (i = 0; i < num_parent; i++) {
1329                /*
1330                 * show stat against the first parent even when doing
1331                 * combined diff.
1332                 */
1333                int stat_opt = (output_format &
1334                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1335                if (i == 0 && stat_opt)
1336                        opt->output_format = stat_opt;
1337                else
1338                        opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1339                diff_tree_oid(&parents->oid[i], oid, "", opt);
1340                diffcore_std(opt);
1341                paths = intersect_paths(paths, i, num_parent);
1342
1343                /* if showing diff, show it in requested order */
1344                if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1345                    orderfile) {
1346                        diffcore_order(orderfile);
1347                }
1348
1349                diff_flush(opt);
1350        }
1351
1352        opt->output_format = output_format;
1353        opt->orderfile = orderfile;
1354        return paths;
1355}
1356
1357
1358/*
1359 * find set of paths that everybody touches, assuming diff is run without
1360 * rename/copy detection, etc, comparing all trees simultaneously (= faster).
1361 */
1362static struct combine_diff_path *find_paths_multitree(
1363        const struct object_id *oid, const struct oid_array *parents,
1364        struct diff_options *opt)
1365{
1366        int i, nparent = parents->nr;
1367        const struct object_id **parents_oid;
1368        struct combine_diff_path paths_head;
1369        struct strbuf base;
1370
1371        ALLOC_ARRAY(parents_oid, nparent);
1372        for (i = 0; i < nparent; i++)
1373                parents_oid[i] = &parents->oid[i];
1374
1375        /* fake list head, so worker can assume it is non-NULL */
1376        paths_head.next = NULL;
1377
1378        strbuf_init(&base, PATH_MAX);
1379        diff_tree_paths(&paths_head, oid, parents_oid, nparent, &base, opt);
1380
1381        strbuf_release(&base);
1382        free(parents_oid);
1383        return paths_head.next;
1384}
1385
1386
1387void diff_tree_combined(const struct object_id *oid,
1388                        const struct oid_array *parents,
1389                        int dense,
1390                        struct rev_info *rev)
1391{
1392        struct diff_options *opt = &rev->diffopt;
1393        struct diff_options diffopts;
1394        struct combine_diff_path *p, *paths;
1395        int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
1396        int need_generic_pathscan;
1397
1398        /* nothing to do, if no parents */
1399        if (!num_parent)
1400                return;
1401
1402        show_log_first = !!rev->loginfo && !rev->no_commit_id;
1403        needsep = 0;
1404        if (show_log_first) {
1405                show_log(rev);
1406
1407                if (rev->verbose_header && opt->output_format &&
1408                    opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1409                    !commit_format_is_empty(rev->commit_format))
1410                        printf("%s%c", diff_line_prefix(opt),
1411                               opt->line_termination);
1412        }
1413
1414        diffopts = *opt;
1415        copy_pathspec(&diffopts.pathspec, &opt->pathspec);
1416        diffopts.flags.recursive = 1;
1417        diffopts.flags.allow_external = 0;
1418
1419        /* find set of paths that everybody touches
1420         *
1421         * NOTE
1422         *
1423         * Diffcore transformations are bound to diff_filespec and logic
1424         * comparing two entries - i.e. they do not apply directly to combine
1425         * diff.
1426         *
1427         * If some of such transformations is requested - we launch generic
1428         * path scanning, which works significantly slower compared to
1429         * simultaneous all-trees-in-one-go scan in find_paths_multitree().
1430         *
1431         * TODO some of the filters could be ported to work on
1432         * combine_diff_paths - i.e. all functionality that skips paths, so in
1433         * theory, we could end up having only multitree path scanning.
1434         *
1435         * NOTE please keep this semantically in sync with diffcore_std()
1436         */
1437        need_generic_pathscan = opt->skip_stat_unmatch  ||
1438                        opt->flags.follow_renames       ||
1439                        opt->break_opt != -1    ||
1440                        opt->detect_rename      ||
1441                        opt->pickaxe            ||
1442                        opt->filter;
1443
1444
1445        if (need_generic_pathscan) {
1446                /*
1447                 * NOTE generic case also handles --stat, as it computes
1448                 * diff(sha1,parent_i) for all i to do the job, specifically
1449                 * for parent0.
1450                 */
1451                paths = find_paths_generic(oid, parents, &diffopts);
1452        }
1453        else {
1454                int stat_opt;
1455                paths = find_paths_multitree(oid, parents, &diffopts);
1456
1457                /*
1458                 * show stat against the first parent even
1459                 * when doing combined diff.
1460                 */
1461                stat_opt = (opt->output_format &
1462                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1463                if (stat_opt) {
1464                        diffopts.output_format = stat_opt;
1465
1466                        diff_tree_oid(&parents->oid[0], oid, "", &diffopts);
1467                        diffcore_std(&diffopts);
1468                        if (opt->orderfile)
1469                                diffcore_order(opt->orderfile);
1470                        diff_flush(&diffopts);
1471                }
1472        }
1473
1474        /* find out number of surviving paths */
1475        for (num_paths = 0, p = paths; p; p = p->next)
1476                num_paths++;
1477
1478        /* order paths according to diffcore_order */
1479        if (opt->orderfile && num_paths) {
1480                struct obj_order *o;
1481
1482                ALLOC_ARRAY(o, num_paths);
1483                for (i = 0, p = paths; p; p = p->next, i++)
1484                        o[i].obj = p;
1485                order_objects(opt->orderfile, path_path, o, num_paths);
1486                for (i = 0; i < num_paths - 1; i++) {
1487                        p = o[i].obj;
1488                        p->next = o[i+1].obj;
1489                }
1490
1491                p = o[num_paths-1].obj;
1492                p->next = NULL;
1493                paths = o[0].obj;
1494                free(o);
1495        }
1496
1497
1498        if (num_paths) {
1499                if (opt->output_format & (DIFF_FORMAT_RAW |
1500                                          DIFF_FORMAT_NAME |
1501                                          DIFF_FORMAT_NAME_STATUS)) {
1502                        for (p = paths; p; p = p->next)
1503                                show_raw_diff(p, num_parent, rev);
1504                        needsep = 1;
1505                }
1506                else if (opt->output_format &
1507                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1508                        needsep = 1;
1509                else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1510                        handle_combined_callback(opt, paths, num_parent, num_paths);
1511
1512                if (opt->output_format & DIFF_FORMAT_PATCH) {
1513                        if (needsep)
1514                                printf("%s%c", diff_line_prefix(opt),
1515                                       opt->line_termination);
1516                        for (p = paths; p; p = p->next)
1517                                show_patch_diff(p, num_parent, dense,
1518                                                0, rev);
1519                }
1520        }
1521
1522        /* Clean things up */
1523        while (paths) {
1524                struct combine_diff_path *tmp = paths;
1525                paths = paths->next;
1526                free(tmp);
1527        }
1528
1529        clear_pathspec(&diffopts.pathspec);
1530}
1531
1532void diff_tree_combined_merge(const struct commit *commit, int dense,
1533                              struct rev_info *rev)
1534{
1535        struct commit_list *parent = get_saved_parents(rev, commit);
1536        struct oid_array parents = OID_ARRAY_INIT;
1537
1538        while (parent) {
1539                oid_array_append(&parents, &parent->item->object.oid);
1540                parent = parent->next;
1541        }
1542        diff_tree_combined(&commit->object.oid, &parents, dense, rev);
1543        oid_array_clear(&parents);
1544}