combine-diff.con commit pickaxe: give diff_grep the same signature as has_changes (db99cb7)
   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 "log-tree.h"
   9#include "refs.h"
  10#include "userdiff.h"
  11
  12static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  13{
  14        struct diff_queue_struct *q = &diff_queued_diff;
  15        struct combine_diff_path *p;
  16        int i;
  17
  18        if (!n) {
  19                struct combine_diff_path *list = NULL, **tail = &list;
  20                for (i = 0; i < q->nr; i++) {
  21                        int len;
  22                        const char *path;
  23                        if (diff_unmodified_pair(q->queue[i]))
  24                                continue;
  25                        path = q->queue[i]->two->path;
  26                        len = strlen(path);
  27                        p = xmalloc(combine_diff_path_size(num_parent, len));
  28                        p->path = (char *) &(p->parent[num_parent]);
  29                        memcpy(p->path, path, len);
  30                        p->path[len] = 0;
  31                        p->len = len;
  32                        p->next = NULL;
  33                        memset(p->parent, 0,
  34                               sizeof(p->parent[0]) * num_parent);
  35
  36                        hashcpy(p->sha1, q->queue[i]->two->sha1);
  37                        p->mode = q->queue[i]->two->mode;
  38                        hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  39                        p->parent[n].mode = q->queue[i]->one->mode;
  40                        p->parent[n].status = q->queue[i]->status;
  41                        *tail = p;
  42                        tail = &p->next;
  43                }
  44                return list;
  45        }
  46
  47        for (p = curr; p; p = p->next) {
  48                int found = 0;
  49                if (!p->len)
  50                        continue;
  51                for (i = 0; i < q->nr; i++) {
  52                        const char *path;
  53                        int len;
  54
  55                        if (diff_unmodified_pair(q->queue[i]))
  56                                continue;
  57                        path = q->queue[i]->two->path;
  58                        len = strlen(path);
  59                        if (len == p->len && !memcmp(path, p->path, len)) {
  60                                found = 1;
  61                                hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  62                                p->parent[n].mode = q->queue[i]->one->mode;
  63                                p->parent[n].status = q->queue[i]->status;
  64                                break;
  65                        }
  66                }
  67                if (!found)
  68                        p->len = 0;
  69        }
  70        return curr;
  71}
  72
  73/* Lines lost from parent */
  74struct lline {
  75        struct lline *next;
  76        int len;
  77        unsigned long parent_map;
  78        char line[FLEX_ARRAY];
  79};
  80
  81/* Lines surviving in the merge result */
  82struct sline {
  83        struct lline *lost_head, **lost_tail;
  84        struct lline *next_lost;
  85        char *bol;
  86        int len;
  87        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  88         * we did not change it).
  89         * bit N is used for "interesting" lines, including context.
  90         * bit (N+1) is used for "do not show deletion before this".
  91         */
  92        unsigned long flag;
  93        unsigned long *p_lno;
  94};
  95
  96static char *grab_blob(const unsigned char *sha1, unsigned int mode,
  97                       unsigned long *size, struct userdiff_driver *textconv,
  98                       const char *path)
  99{
 100        char *blob;
 101        enum object_type type;
 102
 103        if (S_ISGITLINK(mode)) {
 104                blob = xmalloc(100);
 105                *size = snprintf(blob, 100,
 106                                 "Subproject commit %s\n", sha1_to_hex(sha1));
 107        } else if (is_null_sha1(sha1)) {
 108                /* deleted blob */
 109                *size = 0;
 110                return xcalloc(1, 1);
 111        } else if (textconv) {
 112                struct diff_filespec *df = alloc_filespec(path);
 113                fill_filespec(df, sha1, mode);
 114                *size = fill_textconv(textconv, df, &blob);
 115                free_filespec(df);
 116        } else {
 117                blob = read_sha1_file(sha1, &type, size);
 118                if (type != OBJ_BLOB)
 119                        die("object '%s' is not a blob!", sha1_to_hex(sha1));
 120        }
 121        return blob;
 122}
 123
 124static void append_lost(struct sline *sline, int n, const char *line, int len)
 125{
 126        struct lline *lline;
 127        unsigned long this_mask = (1UL<<n);
 128        if (line[len-1] == '\n')
 129                len--;
 130
 131        /* Check to see if we can squash things */
 132        if (sline->lost_head) {
 133                lline = sline->next_lost;
 134                while (lline) {
 135                        if (lline->len == len &&
 136                            !memcmp(lline->line, line, len)) {
 137                                lline->parent_map |= this_mask;
 138                                sline->next_lost = lline->next;
 139                                return;
 140                        }
 141                        lline = lline->next;
 142                }
 143        }
 144
 145        lline = xmalloc(sizeof(*lline) + len + 1);
 146        lline->len = len;
 147        lline->next = NULL;
 148        lline->parent_map = this_mask;
 149        memcpy(lline->line, line, len);
 150        lline->line[len] = 0;
 151        *sline->lost_tail = lline;
 152        sline->lost_tail = &lline->next;
 153        sline->next_lost = NULL;
 154}
 155
 156struct combine_diff_state {
 157        unsigned int lno;
 158        int ob, on, nb, nn;
 159        unsigned long nmask;
 160        int num_parent;
 161        int n;
 162        struct sline *sline;
 163        struct sline *lost_bucket;
 164};
 165
 166static void consume_line(void *state_, char *line, unsigned long len)
 167{
 168        struct combine_diff_state *state = state_;
 169        if (5 < len && !memcmp("@@ -", line, 4)) {
 170                if (parse_hunk_header(line, len,
 171                                      &state->ob, &state->on,
 172                                      &state->nb, &state->nn))
 173                        return;
 174                state->lno = state->nb;
 175                if (state->nn == 0) {
 176                        /* @@ -X,Y +N,0 @@ removed Y lines
 177                         * that would have come *after* line N
 178                         * in the result.  Our lost buckets hang
 179                         * to the line after the removed lines,
 180                         *
 181                         * Note that this is correct even when N == 0,
 182                         * in which case the hunk removes the first
 183                         * line in the file.
 184                         */
 185                        state->lost_bucket = &state->sline[state->nb];
 186                        if (!state->nb)
 187                                state->nb = 1;
 188                } else {
 189                        state->lost_bucket = &state->sline[state->nb-1];
 190                }
 191                if (!state->sline[state->nb-1].p_lno)
 192                        state->sline[state->nb-1].p_lno =
 193                                xcalloc(state->num_parent,
 194                                        sizeof(unsigned long));
 195                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 196                state->lost_bucket->next_lost = state->lost_bucket->lost_head;
 197                return;
 198        }
 199        if (!state->lost_bucket)
 200                return; /* not in any hunk yet */
 201        switch (line[0]) {
 202        case '-':
 203                append_lost(state->lost_bucket, state->n, line+1, len-1);
 204                break;
 205        case '+':
 206                state->sline[state->lno-1].flag |= state->nmask;
 207                state->lno++;
 208                break;
 209        }
 210}
 211
 212static void combine_diff(const unsigned char *parent, unsigned int mode,
 213                         mmfile_t *result_file,
 214                         struct sline *sline, unsigned int cnt, int n,
 215                         int num_parent, int result_deleted,
 216                         struct userdiff_driver *textconv,
 217                         const char *path)
 218{
 219        unsigned int p_lno, lno;
 220        unsigned long nmask = (1UL << n);
 221        xpparam_t xpp;
 222        xdemitconf_t xecfg;
 223        mmfile_t parent_file;
 224        struct combine_diff_state state;
 225        unsigned long sz;
 226
 227        if (result_deleted)
 228                return; /* result deleted */
 229
 230        parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
 231        parent_file.size = sz;
 232        memset(&xpp, 0, sizeof(xpp));
 233        xpp.flags = 0;
 234        memset(&xecfg, 0, sizeof(xecfg));
 235        memset(&state, 0, sizeof(state));
 236        state.nmask = nmask;
 237        state.sline = sline;
 238        state.lno = 1;
 239        state.num_parent = num_parent;
 240        state.n = n;
 241
 242        xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 243                      &xpp, &xecfg);
 244        free(parent_file.ptr);
 245
 246        /* Assign line numbers for this parent.
 247         *
 248         * sline[lno].p_lno[n] records the first line number
 249         * (counting from 1) for parent N if the final hunk display
 250         * started by showing sline[lno] (possibly showing the lost
 251         * lines attached to it first).
 252         */
 253        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 254                struct lline *ll;
 255                sline[lno].p_lno[n] = p_lno;
 256
 257                /* How many lines would this sline advance the p_lno? */
 258                ll = sline[lno].lost_head;
 259                while (ll) {
 260                        if (ll->parent_map & nmask)
 261                                p_lno++; /* '-' means parent had it */
 262                        ll = ll->next;
 263                }
 264                if (lno < cnt && !(sline[lno].flag & nmask))
 265                        p_lno++; /* no '+' means parent had it */
 266        }
 267        sline[lno].p_lno[n] = p_lno; /* trailer */
 268}
 269
 270static unsigned long context = 3;
 271static char combine_marker = '@';
 272
 273static int interesting(struct sline *sline, unsigned long all_mask)
 274{
 275        /* If some parents lost lines here, or if we have added to
 276         * some parent, it is interesting.
 277         */
 278        return ((sline->flag & all_mask) || sline->lost_head);
 279}
 280
 281static unsigned long adjust_hunk_tail(struct sline *sline,
 282                                      unsigned long all_mask,
 283                                      unsigned long hunk_begin,
 284                                      unsigned long i)
 285{
 286        /* i points at the first uninteresting line.  If the last line
 287         * of the hunk was interesting only because it has some
 288         * deletion, then it is not all that interesting for the
 289         * purpose of giving trailing context lines.  This is because
 290         * we output '-' line and then unmodified sline[i-1] itself in
 291         * that case which gives us one extra context line.
 292         */
 293        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 294                i--;
 295        return i;
 296}
 297
 298static unsigned long find_next(struct sline *sline,
 299                               unsigned long mark,
 300                               unsigned long i,
 301                               unsigned long cnt,
 302                               int look_for_uninteresting)
 303{
 304        /* We have examined up to i-1 and are about to look at i.
 305         * Find next interesting or uninteresting line.  Here,
 306         * "interesting" does not mean interesting(), but marked by
 307         * the give_context() function below (i.e. it includes context
 308         * lines that are not interesting to interesting() function
 309         * that are surrounded by interesting() ones.
 310         */
 311        while (i <= cnt)
 312                if (look_for_uninteresting
 313                    ? !(sline[i].flag & mark)
 314                    : (sline[i].flag & mark))
 315                        return i;
 316                else
 317                        i++;
 318        return i;
 319}
 320
 321static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 322{
 323        unsigned long all_mask = (1UL<<num_parent) - 1;
 324        unsigned long mark = (1UL<<num_parent);
 325        unsigned long no_pre_delete = (2UL<<num_parent);
 326        unsigned long i;
 327
 328        /* Two groups of interesting lines may have a short gap of
 329         * uninteresting lines.  Connect such groups to give them a
 330         * bit of context.
 331         *
 332         * We first start from what the interesting() function says,
 333         * and mark them with "mark", and paint context lines with the
 334         * mark.  So interesting() would still say false for such context
 335         * lines but they are treated as "interesting" in the end.
 336         */
 337        i = find_next(sline, mark, 0, cnt, 0);
 338        if (cnt < i)
 339                return 0;
 340
 341        while (i <= cnt) {
 342                unsigned long j = (context < i) ? (i - context) : 0;
 343                unsigned long k;
 344
 345                /* Paint a few lines before the first interesting line. */
 346                while (j < i)
 347                        sline[j++].flag |= mark | no_pre_delete;
 348
 349        again:
 350                /* we know up to i is to be included.  where does the
 351                 * next uninteresting one start?
 352                 */
 353                j = find_next(sline, mark, i, cnt, 1);
 354                if (cnt < j)
 355                        break; /* the rest are all interesting */
 356
 357                /* lookahead context lines */
 358                k = find_next(sline, mark, j, cnt, 0);
 359                j = adjust_hunk_tail(sline, all_mask, i, j);
 360
 361                if (k < j + context) {
 362                        /* k is interesting and [j,k) are not, but
 363                         * paint them interesting because the gap is small.
 364                         */
 365                        while (j < k)
 366                                sline[j++].flag |= mark;
 367                        i = k;
 368                        goto again;
 369                }
 370
 371                /* j is the first uninteresting line and there is
 372                 * no overlap beyond it within context lines.  Paint
 373                 * the trailing edge a bit.
 374                 */
 375                i = k;
 376                k = (j + context < cnt+1) ? j + context : cnt+1;
 377                while (j < k)
 378                        sline[j++].flag |= mark;
 379        }
 380        return 1;
 381}
 382
 383static int make_hunks(struct sline *sline, unsigned long cnt,
 384                       int num_parent, int dense)
 385{
 386        unsigned long all_mask = (1UL<<num_parent) - 1;
 387        unsigned long mark = (1UL<<num_parent);
 388        unsigned long i;
 389        int has_interesting = 0;
 390
 391        for (i = 0; i <= cnt; i++) {
 392                if (interesting(&sline[i], all_mask))
 393                        sline[i].flag |= mark;
 394                else
 395                        sline[i].flag &= ~mark;
 396        }
 397        if (!dense)
 398                return give_context(sline, cnt, num_parent);
 399
 400        /* Look at each hunk, and if we have changes from only one
 401         * parent, or the changes are the same from all but one
 402         * parent, mark that uninteresting.
 403         */
 404        i = 0;
 405        while (i <= cnt) {
 406                unsigned long j, hunk_begin, hunk_end;
 407                unsigned long same_diff;
 408                while (i <= cnt && !(sline[i].flag & mark))
 409                        i++;
 410                if (cnt < i)
 411                        break; /* No more interesting hunks */
 412                hunk_begin = i;
 413                for (j = i + 1; j <= cnt; j++) {
 414                        if (!(sline[j].flag & mark)) {
 415                                /* Look beyond the end to see if there
 416                                 * is an interesting line after this
 417                                 * hunk within context span.
 418                                 */
 419                                unsigned long la; /* lookahead */
 420                                int contin = 0;
 421                                la = adjust_hunk_tail(sline, all_mask,
 422                                                     hunk_begin, j);
 423                                la = (la + context < cnt + 1) ?
 424                                        (la + context) : cnt + 1;
 425                                while (j <= --la) {
 426                                        if (sline[la].flag & mark) {
 427                                                contin = 1;
 428                                                break;
 429                                        }
 430                                }
 431                                if (!contin)
 432                                        break;
 433                                j = la;
 434                        }
 435                }
 436                hunk_end = j;
 437
 438                /* [i..hunk_end) are interesting.  Now is it really
 439                 * interesting?  We check if there are only two versions
 440                 * and the result matches one of them.  That is, we look
 441                 * at:
 442                 *   (+) line, which records lines added to which parents;
 443                 *       this line appears in the result.
 444                 *   (-) line, which records from what parents the line
 445                 *       was removed; this line does not appear in the result.
 446                 * then check the set of parents the result has difference
 447                 * from, from all lines.  If there are lines that has
 448                 * different set of parents that the result has differences
 449                 * from, that means we have more than two versions.
 450                 *
 451                 * Even when we have only two versions, if the result does
 452                 * not match any of the parents, the it should be considered
 453                 * interesting.  In such a case, we would have all '+' line.
 454                 * After passing the above "two versions" test, that would
 455                 * appear as "the same set of parents" to be "all parents".
 456                 */
 457                same_diff = 0;
 458                has_interesting = 0;
 459                for (j = i; j < hunk_end && !has_interesting; j++) {
 460                        unsigned long this_diff = sline[j].flag & all_mask;
 461                        struct lline *ll = sline[j].lost_head;
 462                        if (this_diff) {
 463                                /* This has some changes.  Is it the
 464                                 * same as others?
 465                                 */
 466                                if (!same_diff)
 467                                        same_diff = this_diff;
 468                                else if (same_diff != this_diff) {
 469                                        has_interesting = 1;
 470                                        break;
 471                                }
 472                        }
 473                        while (ll && !has_interesting) {
 474                                /* Lost this line from these parents;
 475                                 * who are they?  Are they the same?
 476                                 */
 477                                this_diff = ll->parent_map;
 478                                if (!same_diff)
 479                                        same_diff = this_diff;
 480                                else if (same_diff != this_diff) {
 481                                        has_interesting = 1;
 482                                }
 483                                ll = ll->next;
 484                        }
 485                }
 486
 487                if (!has_interesting && same_diff != all_mask) {
 488                        /* This hunk is not that interesting after all */
 489                        for (j = hunk_begin; j < hunk_end; j++)
 490                                sline[j].flag &= ~mark;
 491                }
 492                i = hunk_end;
 493        }
 494
 495        has_interesting = give_context(sline, cnt, num_parent);
 496        return has_interesting;
 497}
 498
 499static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 500{
 501        l0 = sline[l0].p_lno[n];
 502        l1 = sline[l1].p_lno[n];
 503        printf(" -%lu,%lu", l0, l1-l0-null_context);
 504}
 505
 506static int hunk_comment_line(const char *bol)
 507{
 508        int ch;
 509
 510        if (!bol)
 511                return 0;
 512        ch = *bol & 0xff;
 513        return (isalpha(ch) || ch == '_' || ch == '$');
 514}
 515
 516static void show_line_to_eol(const char *line, int len, const char *reset)
 517{
 518        int saw_cr_at_eol = 0;
 519        if (len < 0)
 520                len = strlen(line);
 521        saw_cr_at_eol = (len && line[len-1] == '\r');
 522
 523        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 524               reset,
 525               saw_cr_at_eol ? "\r" : "");
 526}
 527
 528static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 529                       int use_color, int result_deleted)
 530{
 531        unsigned long mark = (1UL<<num_parent);
 532        unsigned long no_pre_delete = (2UL<<num_parent);
 533        int i;
 534        unsigned long lno = 0;
 535        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 536        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 537        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 538        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 539        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 540        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 541
 542        if (result_deleted)
 543                return; /* result deleted */
 544
 545        while (1) {
 546                unsigned long hunk_end;
 547                unsigned long rlines;
 548                const char *hunk_comment = NULL;
 549                unsigned long null_context = 0;
 550
 551                while (lno <= cnt && !(sline[lno].flag & mark)) {
 552                        if (hunk_comment_line(sline[lno].bol))
 553                                hunk_comment = sline[lno].bol;
 554                        lno++;
 555                }
 556                if (cnt < lno)
 557                        break;
 558                else {
 559                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 560                                if (!(sline[hunk_end].flag & mark))
 561                                        break;
 562                }
 563                rlines = hunk_end - lno;
 564                if (cnt < hunk_end)
 565                        rlines--; /* pointing at the last delete hunk */
 566
 567                if (!context) {
 568                        /*
 569                         * Even when running with --unified=0, all
 570                         * lines in the hunk needs to be processed in
 571                         * the loop below in order to show the
 572                         * deletion recorded in lost_head.  However,
 573                         * we do not want to show the resulting line
 574                         * with all blank context markers in such a
 575                         * case.  Compensate.
 576                         */
 577                        unsigned long j;
 578                        for (j = lno; j < hunk_end; j++)
 579                                if (!(sline[j].flag & (mark-1)))
 580                                        null_context++;
 581                        rlines -= null_context;
 582                }
 583
 584                fputs(c_frag, stdout);
 585                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 586                for (i = 0; i < num_parent; i++)
 587                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 588                printf(" +%lu,%lu ", lno+1, rlines);
 589                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 590
 591                if (hunk_comment) {
 592                        int comment_end = 0;
 593                        for (i = 0; i < 40; i++) {
 594                                int ch = hunk_comment[i] & 0xff;
 595                                if (!ch || ch == '\n')
 596                                        break;
 597                                if (!isspace(ch))
 598                                    comment_end = i;
 599                        }
 600                        if (comment_end)
 601                                printf("%s%s %s%s", c_reset,
 602                                                    c_plain, c_reset,
 603                                                    c_func);
 604                        for (i = 0; i < comment_end; i++)
 605                                putchar(hunk_comment[i]);
 606                }
 607
 608                printf("%s\n", c_reset);
 609                while (lno < hunk_end) {
 610                        struct lline *ll;
 611                        int j;
 612                        unsigned long p_mask;
 613                        struct sline *sl = &sline[lno++];
 614                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 615                        while (ll) {
 616                                fputs(c_old, stdout);
 617                                for (j = 0; j < num_parent; j++) {
 618                                        if (ll->parent_map & (1UL<<j))
 619                                                putchar('-');
 620                                        else
 621                                                putchar(' ');
 622                                }
 623                                show_line_to_eol(ll->line, -1, c_reset);
 624                                ll = ll->next;
 625                        }
 626                        if (cnt < lno)
 627                                break;
 628                        p_mask = 1;
 629                        if (!(sl->flag & (mark-1))) {
 630                                /*
 631                                 * This sline was here to hang the
 632                                 * lost lines in front of it.
 633                                 */
 634                                if (!context)
 635                                        continue;
 636                                fputs(c_plain, stdout);
 637                        }
 638                        else
 639                                fputs(c_new, stdout);
 640                        for (j = 0; j < num_parent; j++) {
 641                                if (p_mask & sl->flag)
 642                                        putchar('+');
 643                                else
 644                                        putchar(' ');
 645                                p_mask <<= 1;
 646                        }
 647                        show_line_to_eol(sl->bol, sl->len, c_reset);
 648                }
 649        }
 650}
 651
 652static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 653                               int i, int j)
 654{
 655        /* We have already examined parent j and we know parent i
 656         * and parent j are the same, so reuse the combined result
 657         * of parent j for parent i.
 658         */
 659        unsigned long lno, imask, jmask;
 660        imask = (1UL<<i);
 661        jmask = (1UL<<j);
 662
 663        for (lno = 0; lno <= cnt; lno++) {
 664                struct lline *ll = sline->lost_head;
 665                sline->p_lno[i] = sline->p_lno[j];
 666                while (ll) {
 667                        if (ll->parent_map & jmask)
 668                                ll->parent_map |= imask;
 669                        ll = ll->next;
 670                }
 671                if (sline->flag & jmask)
 672                        sline->flag |= imask;
 673                sline++;
 674        }
 675        /* the overall size of the file (sline[cnt]) */
 676        sline->p_lno[i] = sline->p_lno[j];
 677}
 678
 679static void dump_quoted_path(const char *head,
 680                             const char *prefix,
 681                             const char *path,
 682                             const char *c_meta, const char *c_reset)
 683{
 684        static struct strbuf buf = STRBUF_INIT;
 685
 686        strbuf_reset(&buf);
 687        strbuf_addstr(&buf, c_meta);
 688        strbuf_addstr(&buf, head);
 689        quote_two_c_style(&buf, prefix, path, 0);
 690        strbuf_addstr(&buf, c_reset);
 691        puts(buf.buf);
 692}
 693
 694static void show_combined_header(struct combine_diff_path *elem,
 695                                 int num_parent,
 696                                 int dense,
 697                                 struct rev_info *rev,
 698                                 int mode_differs,
 699                                 int show_file_header)
 700{
 701        struct diff_options *opt = &rev->diffopt;
 702        int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 703        const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 704        const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 705        const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 706        const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 707        const char *abb;
 708        int added = 0;
 709        int deleted = 0;
 710        int i;
 711
 712        if (rev->loginfo && !rev->no_commit_id)
 713                show_log(rev);
 714
 715        dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 716                         "", elem->path, c_meta, c_reset);
 717        printf("%sindex ", c_meta);
 718        for (i = 0; i < num_parent; i++) {
 719                abb = find_unique_abbrev(elem->parent[i].sha1,
 720                                         abbrev);
 721                printf("%s%s", i ? "," : "", abb);
 722        }
 723        abb = find_unique_abbrev(elem->sha1, abbrev);
 724        printf("..%s%s\n", abb, c_reset);
 725
 726        if (mode_differs) {
 727                deleted = !elem->mode;
 728
 729                /* We say it was added if nobody had it */
 730                added = !deleted;
 731                for (i = 0; added && i < num_parent; i++)
 732                        if (elem->parent[i].status !=
 733                            DIFF_STATUS_ADDED)
 734                                added = 0;
 735                if (added)
 736                        printf("%snew file mode %06o",
 737                               c_meta, elem->mode);
 738                else {
 739                        if (deleted)
 740                                printf("%sdeleted file ", c_meta);
 741                        printf("mode ");
 742                        for (i = 0; i < num_parent; i++) {
 743                                printf("%s%06o", i ? "," : "",
 744                                       elem->parent[i].mode);
 745                        }
 746                        if (elem->mode)
 747                                printf("..%06o", elem->mode);
 748                }
 749                printf("%s\n", c_reset);
 750        }
 751
 752        if (!show_file_header)
 753                return;
 754
 755        if (added)
 756                dump_quoted_path("--- ", "", "/dev/null",
 757                                 c_meta, c_reset);
 758        else
 759                dump_quoted_path("--- ", a_prefix, elem->path,
 760                                 c_meta, c_reset);
 761        if (deleted)
 762                dump_quoted_path("+++ ", "", "/dev/null",
 763                                 c_meta, c_reset);
 764        else
 765                dump_quoted_path("+++ ", b_prefix, elem->path,
 766                                 c_meta, c_reset);
 767}
 768
 769static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 770                            int dense, int working_tree_file,
 771                            struct rev_info *rev)
 772{
 773        struct diff_options *opt = &rev->diffopt;
 774        unsigned long result_size, cnt, lno;
 775        int result_deleted = 0;
 776        char *result, *cp;
 777        struct sline *sline; /* survived lines */
 778        int mode_differs = 0;
 779        int i, show_hunks;
 780        mmfile_t result_file;
 781        struct userdiff_driver *userdiff;
 782        struct userdiff_driver *textconv = NULL;
 783        int is_binary;
 784
 785        context = opt->context;
 786        userdiff = userdiff_find_by_path(elem->path);
 787        if (!userdiff)
 788                userdiff = userdiff_find_by_name("default");
 789        if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV))
 790                textconv = userdiff_get_textconv(userdiff);
 791
 792        /* Read the result of merge first */
 793        if (!working_tree_file)
 794                result = grab_blob(elem->sha1, elem->mode, &result_size,
 795                                   textconv, elem->path);
 796        else {
 797                /* Used by diff-tree to read from the working tree */
 798                struct stat st;
 799                int fd = -1;
 800
 801                if (lstat(elem->path, &st) < 0)
 802                        goto deleted_file;
 803
 804                if (S_ISLNK(st.st_mode)) {
 805                        struct strbuf buf = STRBUF_INIT;
 806
 807                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
 808                                error("readlink(%s): %s", elem->path,
 809                                      strerror(errno));
 810                                return;
 811                        }
 812                        result_size = buf.len;
 813                        result = strbuf_detach(&buf, NULL);
 814                        elem->mode = canon_mode(st.st_mode);
 815                } else if (S_ISDIR(st.st_mode)) {
 816                        unsigned char sha1[20];
 817                        if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
 818                                result = grab_blob(elem->sha1, elem->mode,
 819                                                   &result_size, NULL, NULL);
 820                        else
 821                                result = grab_blob(sha1, elem->mode,
 822                                                   &result_size, NULL, NULL);
 823                } else if (textconv) {
 824                        struct diff_filespec *df = alloc_filespec(elem->path);
 825                        fill_filespec(df, null_sha1, st.st_mode);
 826                        result_size = fill_textconv(textconv, df, &result);
 827                        free_filespec(df);
 828                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
 829                        size_t len = xsize_t(st.st_size);
 830                        ssize_t done;
 831                        int is_file, i;
 832
 833                        elem->mode = canon_mode(st.st_mode);
 834                        /* if symlinks don't work, assume symlink if all parents
 835                         * are symlinks
 836                         */
 837                        is_file = has_symlinks;
 838                        for (i = 0; !is_file && i < num_parent; i++)
 839                                is_file = !S_ISLNK(elem->parent[i].mode);
 840                        if (!is_file)
 841                                elem->mode = canon_mode(S_IFLNK);
 842
 843                        result_size = len;
 844                        result = xmalloc(len + 1);
 845
 846                        done = read_in_full(fd, result, len);
 847                        if (done < 0)
 848                                die_errno("read error '%s'", elem->path);
 849                        else if (done < len)
 850                                die("early EOF '%s'", elem->path);
 851
 852                        result[len] = 0;
 853
 854                        /* If not a fake symlink, apply filters, e.g. autocrlf */
 855                        if (is_file) {
 856                                struct strbuf buf = STRBUF_INIT;
 857
 858                                if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 859                                        free(result);
 860                                        result = strbuf_detach(&buf, &len);
 861                                        result_size = len;
 862                                }
 863                        }
 864                }
 865                else {
 866                deleted_file:
 867                        result_deleted = 1;
 868                        result_size = 0;
 869                        elem->mode = 0;
 870                        result = xcalloc(1, 1);
 871                }
 872
 873                if (0 <= fd)
 874                        close(fd);
 875        }
 876
 877        for (i = 0; i < num_parent; i++) {
 878                if (elem->parent[i].mode != elem->mode) {
 879                        mode_differs = 1;
 880                        break;
 881                }
 882        }
 883
 884        if (textconv)
 885                is_binary = 0;
 886        else if (userdiff->binary != -1)
 887                is_binary = userdiff->binary;
 888        else {
 889                is_binary = buffer_is_binary(result, result_size);
 890                for (i = 0; !is_binary && i < num_parent; i++) {
 891                        char *buf;
 892                        unsigned long size;
 893                        buf = grab_blob(elem->parent[i].sha1,
 894                                        elem->parent[i].mode,
 895                                        &size, NULL, NULL);
 896                        if (buffer_is_binary(buf, size))
 897                                is_binary = 1;
 898                        free(buf);
 899                }
 900        }
 901        if (is_binary) {
 902                show_combined_header(elem, num_parent, dense, rev,
 903                                     mode_differs, 0);
 904                printf("Binary files differ\n");
 905                free(result);
 906                return;
 907        }
 908
 909        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 910                if (*cp == '\n')
 911                        cnt++;
 912        }
 913        if (result_size && result[result_size-1] != '\n')
 914                cnt++; /* incomplete line */
 915
 916        sline = xcalloc(cnt+2, sizeof(*sline));
 917        sline[0].bol = result;
 918        for (lno = 0; lno <= cnt + 1; lno++) {
 919                sline[lno].lost_tail = &sline[lno].lost_head;
 920                sline[lno].flag = 0;
 921        }
 922        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 923                if (*cp == '\n') {
 924                        sline[lno].len = cp - sline[lno].bol;
 925                        lno++;
 926                        if (lno < cnt)
 927                                sline[lno].bol = cp + 1;
 928                }
 929        }
 930        if (result_size && result[result_size-1] != '\n')
 931                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 932
 933        result_file.ptr = result;
 934        result_file.size = result_size;
 935
 936        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 937         * for deletion hunk at the end.
 938         */
 939        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 940        for (lno = 0; lno <= cnt; lno++)
 941                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 942
 943        for (i = 0; i < num_parent; i++) {
 944                int j;
 945                for (j = 0; j < i; j++) {
 946                        if (!hashcmp(elem->parent[i].sha1,
 947                                     elem->parent[j].sha1)) {
 948                                reuse_combine_diff(sline, cnt, i, j);
 949                                break;
 950                        }
 951                }
 952                if (i <= j)
 953                        combine_diff(elem->parent[i].sha1,
 954                                     elem->parent[i].mode,
 955                                     &result_file, sline,
 956                                     cnt, i, num_parent, result_deleted,
 957                                     textconv, elem->path);
 958        }
 959
 960        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 961
 962        if (show_hunks || mode_differs || working_tree_file) {
 963                show_combined_header(elem, num_parent, dense, rev,
 964                                     mode_differs, 1);
 965                dump_sline(sline, cnt, num_parent,
 966                           opt->use_color, result_deleted);
 967        }
 968        free(result);
 969
 970        for (lno = 0; lno < cnt; lno++) {
 971                if (sline[lno].lost_head) {
 972                        struct lline *ll = sline[lno].lost_head;
 973                        while (ll) {
 974                                struct lline *tmp = ll;
 975                                ll = ll->next;
 976                                free(tmp);
 977                        }
 978                }
 979        }
 980        free(sline[0].p_lno);
 981        free(sline);
 982}
 983
 984#define COLONS "::::::::::::::::::::::::::::::::"
 985
 986static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 987{
 988        struct diff_options *opt = &rev->diffopt;
 989        int i, offset;
 990        const char *prefix;
 991        int line_termination, inter_name_termination;
 992
 993        line_termination = opt->line_termination;
 994        inter_name_termination = '\t';
 995        if (!line_termination)
 996                inter_name_termination = 0;
 997
 998        if (rev->loginfo && !rev->no_commit_id)
 999                show_log(rev);
1000
1001        if (opt->output_format & DIFF_FORMAT_RAW) {
1002                offset = strlen(COLONS) - num_parent;
1003                if (offset < 0)
1004                        offset = 0;
1005                prefix = COLONS + offset;
1006
1007                /* Show the modes */
1008                for (i = 0; i < num_parent; i++) {
1009                        printf("%s%06o", prefix, p->parent[i].mode);
1010                        prefix = " ";
1011                }
1012                printf("%s%06o", prefix, p->mode);
1013
1014                /* Show sha1's */
1015                for (i = 0; i < num_parent; i++)
1016                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
1017                                                         opt->abbrev));
1018                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
1019        }
1020
1021        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1022                for (i = 0; i < num_parent; i++)
1023                        putchar(p->parent[i].status);
1024                putchar(inter_name_termination);
1025        }
1026
1027        write_name_quoted(p->path, stdout, line_termination);
1028}
1029
1030/*
1031 * The result (p->elem) is from the working tree and their
1032 * parents are typically from multiple stages during a merge
1033 * (i.e. diff-files) or the state in HEAD and in the index
1034 * (i.e. diff-index).
1035 */
1036void show_combined_diff(struct combine_diff_path *p,
1037                       int num_parent,
1038                       int dense,
1039                       struct rev_info *rev)
1040{
1041        struct diff_options *opt = &rev->diffopt;
1042        if (!p->len)
1043                return;
1044        if (opt->output_format & (DIFF_FORMAT_RAW |
1045                                  DIFF_FORMAT_NAME |
1046                                  DIFF_FORMAT_NAME_STATUS))
1047                show_raw_diff(p, num_parent, rev);
1048        else if (opt->output_format & DIFF_FORMAT_PATCH)
1049                show_patch_diff(p, num_parent, dense, 1, rev);
1050}
1051
1052static void free_combined_pair(struct diff_filepair *pair)
1053{
1054        free(pair->two);
1055        free(pair);
1056}
1057
1058/*
1059 * A combine_diff_path expresses N parents on the LHS against 1 merge
1060 * result. Synthesize a diff_filepair that has N entries on the "one"
1061 * side and 1 entry on the "two" side.
1062 *
1063 * In the future, we might want to add more data to combine_diff_path
1064 * so that we can fill fields we are ignoring (most notably, size) here,
1065 * but currently nobody uses it, so this should suffice for now.
1066 */
1067static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1068                                           int num_parent)
1069{
1070        int i;
1071        struct diff_filepair *pair;
1072        struct diff_filespec *pool;
1073
1074        pair = xmalloc(sizeof(*pair));
1075        pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec));
1076        pair->one = pool + 1;
1077        pair->two = pool;
1078
1079        for (i = 0; i < num_parent; i++) {
1080                pair->one[i].path = p->path;
1081                pair->one[i].mode = p->parent[i].mode;
1082                hashcpy(pair->one[i].sha1, p->parent[i].sha1);
1083                pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
1084                pair->one[i].has_more_entries = 1;
1085        }
1086        pair->one[num_parent - 1].has_more_entries = 0;
1087
1088        pair->two->path = p->path;
1089        pair->two->mode = p->mode;
1090        hashcpy(pair->two->sha1, p->sha1);
1091        pair->two->sha1_valid = !is_null_sha1(p->sha1);
1092        return pair;
1093}
1094
1095static void handle_combined_callback(struct diff_options *opt,
1096                                     struct combine_diff_path *paths,
1097                                     int num_parent,
1098                                     int num_paths)
1099{
1100        struct combine_diff_path *p;
1101        struct diff_queue_struct q;
1102        int i;
1103
1104        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1105        q.alloc = num_paths;
1106        q.nr = num_paths;
1107        for (i = 0, p = paths; p; p = p->next) {
1108                if (!p->len)
1109                        continue;
1110                q.queue[i++] = combined_pair(p, num_parent);
1111        }
1112        opt->format_callback(&q, opt, opt->format_callback_data);
1113        for (i = 0; i < num_paths; i++)
1114                free_combined_pair(q.queue[i]);
1115        free(q.queue);
1116}
1117
1118void diff_tree_combined(const unsigned char *sha1,
1119                        const unsigned char parent[][20],
1120                        int num_parent,
1121                        int dense,
1122                        struct rev_info *rev)
1123{
1124        struct diff_options *opt = &rev->diffopt;
1125        struct diff_options diffopts;
1126        struct combine_diff_path *p, *paths = NULL;
1127        int i, num_paths, needsep, show_log_first;
1128
1129        diffopts = *opt;
1130        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1131        DIFF_OPT_SET(&diffopts, RECURSIVE);
1132        DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
1133
1134        show_log_first = !!rev->loginfo && !rev->no_commit_id;
1135        needsep = 0;
1136        /* find set of paths that everybody touches */
1137        for (i = 0; i < num_parent; i++) {
1138                /* show stat against the first parent even
1139                 * when doing combined diff.
1140                 */
1141                int stat_opt = (opt->output_format &
1142                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1143                if (i == 0 && stat_opt)
1144                        diffopts.output_format = stat_opt;
1145                else
1146                        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1147                diff_tree_sha1(parent[i], sha1, "", &diffopts);
1148                diffcore_std(&diffopts);
1149                paths = intersect_paths(paths, i, num_parent);
1150
1151                if (show_log_first && i == 0) {
1152                        show_log(rev);
1153                        if (rev->verbose_header && opt->output_format)
1154                                putchar(opt->line_termination);
1155                }
1156                diff_flush(&diffopts);
1157        }
1158
1159        /* find out surviving paths */
1160        for (num_paths = 0, p = paths; p; p = p->next) {
1161                if (p->len)
1162                        num_paths++;
1163        }
1164        if (num_paths) {
1165                if (opt->output_format & (DIFF_FORMAT_RAW |
1166                                          DIFF_FORMAT_NAME |
1167                                          DIFF_FORMAT_NAME_STATUS)) {
1168                        for (p = paths; p; p = p->next) {
1169                                if (p->len)
1170                                        show_raw_diff(p, num_parent, rev);
1171                        }
1172                        needsep = 1;
1173                }
1174                else if (opt->output_format &
1175                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1176                        needsep = 1;
1177                else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1178                        handle_combined_callback(opt, paths, num_parent, num_paths);
1179
1180                if (opt->output_format & DIFF_FORMAT_PATCH) {
1181                        if (needsep)
1182                                putchar(opt->line_termination);
1183                        for (p = paths; p; p = p->next) {
1184                                if (p->len)
1185                                        show_patch_diff(p, num_parent, dense,
1186                                                        0, rev);
1187                        }
1188                }
1189        }
1190
1191        /* Clean things up */
1192        while (paths) {
1193                struct combine_diff_path *tmp = paths;
1194                paths = paths->next;
1195                free(tmp);
1196        }
1197}
1198
1199void diff_tree_combined_merge(const unsigned char *sha1,
1200                             int dense, struct rev_info *rev)
1201{
1202        int num_parent;
1203        const unsigned char (*parent)[20];
1204        struct commit *commit = lookup_commit(sha1);
1205        struct commit_list *parents;
1206
1207        /* count parents */
1208        for (parents = commit->parents, num_parent = 0;
1209             parents;
1210             parents = parents->next, num_parent++)
1211                ; /* nothing */
1212
1213        parent = xmalloc(num_parent * sizeof(*parent));
1214        for (parents = commit->parents, num_parent = 0;
1215             parents;
1216             parents = parents->next, num_parent++)
1217                hashcpy((unsigned char *)(parent + num_parent),
1218                        parents->item->object.sha1);
1219        diff_tree_combined(sha1, parent, num_parent, dense, rev);
1220}