combine-diff.con commit Merge branch 'pw/p4-use-client-spec-branch-detection' (7c88ec0)
   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#include "sha1-array.h"
  12
  13static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  14{
  15        struct diff_queue_struct *q = &diff_queued_diff;
  16        struct combine_diff_path *p;
  17        int i;
  18
  19        if (!n) {
  20                struct combine_diff_path *list = NULL, **tail = &list;
  21                for (i = 0; i < q->nr; i++) {
  22                        int len;
  23                        const char *path;
  24                        if (diff_unmodified_pair(q->queue[i]))
  25                                continue;
  26                        path = q->queue[i]->two->path;
  27                        len = strlen(path);
  28                        p = xmalloc(combine_diff_path_size(num_parent, len));
  29                        p->path = (char *) &(p->parent[num_parent]);
  30                        memcpy(p->path, path, len);
  31                        p->path[len] = 0;
  32                        p->len = len;
  33                        p->next = NULL;
  34                        memset(p->parent, 0,
  35                               sizeof(p->parent[0]) * num_parent);
  36
  37                        hashcpy(p->sha1, q->queue[i]->two->sha1);
  38                        p->mode = q->queue[i]->two->mode;
  39                        hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  40                        p->parent[n].mode = q->queue[i]->one->mode;
  41                        p->parent[n].status = q->queue[i]->status;
  42                        *tail = p;
  43                        tail = &p->next;
  44                }
  45                return list;
  46        }
  47
  48        for (p = curr; p; p = p->next) {
  49                int found = 0;
  50                if (!p->len)
  51                        continue;
  52                for (i = 0; i < q->nr; i++) {
  53                        const char *path;
  54                        int len;
  55
  56                        if (diff_unmodified_pair(q->queue[i]))
  57                                continue;
  58                        path = q->queue[i]->two->path;
  59                        len = strlen(path);
  60                        if (len == p->len && !memcmp(path, p->path, len)) {
  61                                found = 1;
  62                                hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  63                                p->parent[n].mode = q->queue[i]->one->mode;
  64                                p->parent[n].status = q->queue[i]->status;
  65                                break;
  66                        }
  67                }
  68                if (!found)
  69                        p->len = 0;
  70        }
  71        return curr;
  72}
  73
  74/* Lines lost from parent */
  75struct lline {
  76        struct lline *next;
  77        int len;
  78        unsigned long parent_map;
  79        char line[FLEX_ARRAY];
  80};
  81
  82/* Lines surviving in the merge result */
  83struct sline {
  84        struct lline *lost_head, **lost_tail;
  85        struct lline *next_lost;
  86        char *bol;
  87        int len;
  88        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  89         * we did not change it).
  90         * bit N is used for "interesting" lines, including context.
  91         * bit (N+1) is used for "do not show deletion before this".
  92         */
  93        unsigned long flag;
  94        unsigned long *p_lno;
  95};
  96
  97static char *grab_blob(const unsigned char *sha1, unsigned int mode,
  98                       unsigned long *size, struct userdiff_driver *textconv,
  99                       const char *path)
 100{
 101        char *blob;
 102        enum object_type type;
 103
 104        if (S_ISGITLINK(mode)) {
 105                blob = xmalloc(100);
 106                *size = snprintf(blob, 100,
 107                                 "Subproject commit %s\n", sha1_to_hex(sha1));
 108        } else if (is_null_sha1(sha1)) {
 109                /* deleted blob */
 110                *size = 0;
 111                return xcalloc(1, 1);
 112        } else if (textconv) {
 113                struct diff_filespec *df = alloc_filespec(path);
 114                fill_filespec(df, sha1, 1, mode);
 115                *size = fill_textconv(textconv, df, &blob);
 116                free_filespec(df);
 117        } else {
 118                blob = read_sha1_file(sha1, &type, size);
 119                if (type != OBJ_BLOB)
 120                        die("object '%s' is not a blob!", sha1_to_hex(sha1));
 121        }
 122        return blob;
 123}
 124
 125static void append_lost(struct sline *sline, int n, const char *line, int len)
 126{
 127        struct lline *lline;
 128        unsigned long this_mask = (1UL<<n);
 129        if (line[len-1] == '\n')
 130                len--;
 131
 132        /* Check to see if we can squash things */
 133        if (sline->lost_head) {
 134                lline = sline->next_lost;
 135                while (lline) {
 136                        if (lline->len == len &&
 137                            !memcmp(lline->line, line, len)) {
 138                                lline->parent_map |= this_mask;
 139                                sline->next_lost = lline->next;
 140                                return;
 141                        }
 142                        lline = lline->next;
 143                }
 144        }
 145
 146        lline = xmalloc(sizeof(*lline) + len + 1);
 147        lline->len = len;
 148        lline->next = NULL;
 149        lline->parent_map = this_mask;
 150        memcpy(lline->line, line, len);
 151        lline->line[len] = 0;
 152        *sline->lost_tail = lline;
 153        sline->lost_tail = &lline->next;
 154        sline->next_lost = NULL;
 155}
 156
 157struct combine_diff_state {
 158        unsigned int lno;
 159        int ob, on, nb, nn;
 160        unsigned long nmask;
 161        int num_parent;
 162        int n;
 163        struct sline *sline;
 164        struct sline *lost_bucket;
 165};
 166
 167static void consume_line(void *state_, char *line, unsigned long len)
 168{
 169        struct combine_diff_state *state = state_;
 170        if (5 < len && !memcmp("@@ -", line, 4)) {
 171                if (parse_hunk_header(line, len,
 172                                      &state->ob, &state->on,
 173                                      &state->nb, &state->nn))
 174                        return;
 175                state->lno = state->nb;
 176                if (state->nn == 0) {
 177                        /* @@ -X,Y +N,0 @@ removed Y lines
 178                         * that would have come *after* line N
 179                         * in the result.  Our lost buckets hang
 180                         * to the line after the removed lines,
 181                         *
 182                         * Note that this is correct even when N == 0,
 183                         * in which case the hunk removes the first
 184                         * line in the file.
 185                         */
 186                        state->lost_bucket = &state->sline[state->nb];
 187                        if (!state->nb)
 188                                state->nb = 1;
 189                } else {
 190                        state->lost_bucket = &state->sline[state->nb-1];
 191                }
 192                if (!state->sline[state->nb-1].p_lno)
 193                        state->sline[state->nb-1].p_lno =
 194                                xcalloc(state->num_parent,
 195                                        sizeof(unsigned long));
 196                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 197                state->lost_bucket->next_lost = state->lost_bucket->lost_head;
 198                return;
 199        }
 200        if (!state->lost_bucket)
 201                return; /* not in any hunk yet */
 202        switch (line[0]) {
 203        case '-':
 204                append_lost(state->lost_bucket, state->n, line+1, len-1);
 205                break;
 206        case '+':
 207                state->sline[state->lno-1].flag |= state->nmask;
 208                state->lno++;
 209                break;
 210        }
 211}
 212
 213static void combine_diff(const unsigned char *parent, unsigned int mode,
 214                         mmfile_t *result_file,
 215                         struct sline *sline, unsigned int cnt, int n,
 216                         int num_parent, int result_deleted,
 217                         struct userdiff_driver *textconv,
 218                         const char *path)
 219{
 220        unsigned int p_lno, lno;
 221        unsigned long nmask = (1UL << n);
 222        xpparam_t xpp;
 223        xdemitconf_t xecfg;
 224        mmfile_t parent_file;
 225        struct combine_diff_state state;
 226        unsigned long sz;
 227
 228        if (result_deleted)
 229                return; /* result deleted */
 230
 231        parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
 232        parent_file.size = sz;
 233        memset(&xpp, 0, sizeof(xpp));
 234        xpp.flags = 0;
 235        memset(&xecfg, 0, sizeof(xecfg));
 236        memset(&state, 0, sizeof(state));
 237        state.nmask = nmask;
 238        state.sline = sline;
 239        state.lno = 1;
 240        state.num_parent = num_parent;
 241        state.n = n;
 242
 243        xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 244                      &xpp, &xecfg);
 245        free(parent_file.ptr);
 246
 247        /* Assign line numbers for this parent.
 248         *
 249         * sline[lno].p_lno[n] records the first line number
 250         * (counting from 1) for parent N if the final hunk display
 251         * started by showing sline[lno] (possibly showing the lost
 252         * lines attached to it first).
 253         */
 254        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 255                struct lline *ll;
 256                sline[lno].p_lno[n] = p_lno;
 257
 258                /* How many lines would this sline advance the p_lno? */
 259                ll = sline[lno].lost_head;
 260                while (ll) {
 261                        if (ll->parent_map & nmask)
 262                                p_lno++; /* '-' means parent had it */
 263                        ll = ll->next;
 264                }
 265                if (lno < cnt && !(sline[lno].flag & nmask))
 266                        p_lno++; /* no '+' means parent had it */
 267        }
 268        sline[lno].p_lno[n] = p_lno; /* trailer */
 269}
 270
 271static unsigned long context = 3;
 272static char combine_marker = '@';
 273
 274static int interesting(struct sline *sline, unsigned long all_mask)
 275{
 276        /* If some parents lost lines here, or if we have added to
 277         * some parent, it is interesting.
 278         */
 279        return ((sline->flag & all_mask) || sline->lost_head);
 280}
 281
 282static unsigned long adjust_hunk_tail(struct sline *sline,
 283                                      unsigned long all_mask,
 284                                      unsigned long hunk_begin,
 285                                      unsigned long i)
 286{
 287        /* i points at the first uninteresting line.  If the last line
 288         * of the hunk was interesting only because it has some
 289         * deletion, then it is not all that interesting for the
 290         * purpose of giving trailing context lines.  This is because
 291         * we output '-' line and then unmodified sline[i-1] itself in
 292         * that case which gives us one extra context line.
 293         */
 294        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 295                i--;
 296        return i;
 297}
 298
 299static unsigned long find_next(struct sline *sline,
 300                               unsigned long mark,
 301                               unsigned long i,
 302                               unsigned long cnt,
 303                               int look_for_uninteresting)
 304{
 305        /* We have examined up to i-1 and are about to look at i.
 306         * Find next interesting or uninteresting line.  Here,
 307         * "interesting" does not mean interesting(), but marked by
 308         * the give_context() function below (i.e. it includes context
 309         * lines that are not interesting to interesting() function
 310         * that are surrounded by interesting() ones.
 311         */
 312        while (i <= cnt)
 313                if (look_for_uninteresting
 314                    ? !(sline[i].flag & mark)
 315                    : (sline[i].flag & mark))
 316                        return i;
 317                else
 318                        i++;
 319        return i;
 320}
 321
 322static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 323{
 324        unsigned long all_mask = (1UL<<num_parent) - 1;
 325        unsigned long mark = (1UL<<num_parent);
 326        unsigned long no_pre_delete = (2UL<<num_parent);
 327        unsigned long i;
 328
 329        /* Two groups of interesting lines may have a short gap of
 330         * uninteresting lines.  Connect such groups to give them a
 331         * bit of context.
 332         *
 333         * We first start from what the interesting() function says,
 334         * and mark them with "mark", and paint context lines with the
 335         * mark.  So interesting() would still say false for such context
 336         * lines but they are treated as "interesting" in the end.
 337         */
 338        i = find_next(sline, mark, 0, cnt, 0);
 339        if (cnt < i)
 340                return 0;
 341
 342        while (i <= cnt) {
 343                unsigned long j = (context < i) ? (i - context) : 0;
 344                unsigned long k;
 345
 346                /* Paint a few lines before the first interesting line. */
 347                while (j < i)
 348                        sline[j++].flag |= mark | no_pre_delete;
 349
 350        again:
 351                /* we know up to i is to be included.  where does the
 352                 * next uninteresting one start?
 353                 */
 354                j = find_next(sline, mark, i, cnt, 1);
 355                if (cnt < j)
 356                        break; /* the rest are all interesting */
 357
 358                /* lookahead context lines */
 359                k = find_next(sline, mark, j, cnt, 0);
 360                j = adjust_hunk_tail(sline, all_mask, i, j);
 361
 362                if (k < j + context) {
 363                        /* k is interesting and [j,k) are not, but
 364                         * paint them interesting because the gap is small.
 365                         */
 366                        while (j < k)
 367                                sline[j++].flag |= mark;
 368                        i = k;
 369                        goto again;
 370                }
 371
 372                /* j is the first uninteresting line and there is
 373                 * no overlap beyond it within context lines.  Paint
 374                 * the trailing edge a bit.
 375                 */
 376                i = k;
 377                k = (j + context < cnt+1) ? j + context : cnt+1;
 378                while (j < k)
 379                        sline[j++].flag |= mark;
 380        }
 381        return 1;
 382}
 383
 384static int make_hunks(struct sline *sline, unsigned long cnt,
 385                       int num_parent, int dense)
 386{
 387        unsigned long all_mask = (1UL<<num_parent) - 1;
 388        unsigned long mark = (1UL<<num_parent);
 389        unsigned long i;
 390        int has_interesting = 0;
 391
 392        for (i = 0; i <= cnt; i++) {
 393                if (interesting(&sline[i], all_mask))
 394                        sline[i].flag |= mark;
 395                else
 396                        sline[i].flag &= ~mark;
 397        }
 398        if (!dense)
 399                return give_context(sline, cnt, num_parent);
 400
 401        /* Look at each hunk, and if we have changes from only one
 402         * parent, or the changes are the same from all but one
 403         * parent, mark that uninteresting.
 404         */
 405        i = 0;
 406        while (i <= cnt) {
 407                unsigned long j, hunk_begin, hunk_end;
 408                unsigned long same_diff;
 409                while (i <= cnt && !(sline[i].flag & mark))
 410                        i++;
 411                if (cnt < i)
 412                        break; /* No more interesting hunks */
 413                hunk_begin = i;
 414                for (j = i + 1; j <= cnt; j++) {
 415                        if (!(sline[j].flag & mark)) {
 416                                /* Look beyond the end to see if there
 417                                 * is an interesting line after this
 418                                 * hunk within context span.
 419                                 */
 420                                unsigned long la; /* lookahead */
 421                                int contin = 0;
 422                                la = adjust_hunk_tail(sline, all_mask,
 423                                                     hunk_begin, j);
 424                                la = (la + context < cnt + 1) ?
 425                                        (la + context) : cnt + 1;
 426                                while (la && j <= --la) {
 427                                        if (sline[la].flag & mark) {
 428                                                contin = 1;
 429                                                break;
 430                                        }
 431                                }
 432                                if (!contin)
 433                                        break;
 434                                j = la;
 435                        }
 436                }
 437                hunk_end = j;
 438
 439                /* [i..hunk_end) are interesting.  Now is it really
 440                 * interesting?  We check if there are only two versions
 441                 * and the result matches one of them.  That is, we look
 442                 * at:
 443                 *   (+) line, which records lines added to which parents;
 444                 *       this line appears in the result.
 445                 *   (-) line, which records from what parents the line
 446                 *       was removed; this line does not appear in the result.
 447                 * then check the set of parents the result has difference
 448                 * from, from all lines.  If there are lines that has
 449                 * different set of parents that the result has differences
 450                 * from, that means we have more than two versions.
 451                 *
 452                 * Even when we have only two versions, if the result does
 453                 * not match any of the parents, the it should be considered
 454                 * interesting.  In such a case, we would have all '+' line.
 455                 * After passing the above "two versions" test, that would
 456                 * appear as "the same set of parents" to be "all parents".
 457                 */
 458                same_diff = 0;
 459                has_interesting = 0;
 460                for (j = i; j < hunk_end && !has_interesting; j++) {
 461                        unsigned long this_diff = sline[j].flag & all_mask;
 462                        struct lline *ll = sline[j].lost_head;
 463                        if (this_diff) {
 464                                /* This has some changes.  Is it the
 465                                 * same as others?
 466                                 */
 467                                if (!same_diff)
 468                                        same_diff = this_diff;
 469                                else if (same_diff != this_diff) {
 470                                        has_interesting = 1;
 471                                        break;
 472                                }
 473                        }
 474                        while (ll && !has_interesting) {
 475                                /* Lost this line from these parents;
 476                                 * who are they?  Are they the same?
 477                                 */
 478                                this_diff = ll->parent_map;
 479                                if (!same_diff)
 480                                        same_diff = this_diff;
 481                                else if (same_diff != this_diff) {
 482                                        has_interesting = 1;
 483                                }
 484                                ll = ll->next;
 485                        }
 486                }
 487
 488                if (!has_interesting && same_diff != all_mask) {
 489                        /* This hunk is not that interesting after all */
 490                        for (j = hunk_begin; j < hunk_end; j++)
 491                                sline[j].flag &= ~mark;
 492                }
 493                i = hunk_end;
 494        }
 495
 496        has_interesting = give_context(sline, cnt, num_parent);
 497        return has_interesting;
 498}
 499
 500static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 501{
 502        l0 = sline[l0].p_lno[n];
 503        l1 = sline[l1].p_lno[n];
 504        printf(" -%lu,%lu", l0, l1-l0-null_context);
 505}
 506
 507static int hunk_comment_line(const char *bol)
 508{
 509        int ch;
 510
 511        if (!bol)
 512                return 0;
 513        ch = *bol & 0xff;
 514        return (isalpha(ch) || ch == '_' || ch == '$');
 515}
 516
 517static void show_line_to_eol(const char *line, int len, const char *reset)
 518{
 519        int saw_cr_at_eol = 0;
 520        if (len < 0)
 521                len = strlen(line);
 522        saw_cr_at_eol = (len && line[len-1] == '\r');
 523
 524        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 525               reset,
 526               saw_cr_at_eol ? "\r" : "");
 527}
 528
 529static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 530                       int use_color, int result_deleted)
 531{
 532        unsigned long mark = (1UL<<num_parent);
 533        unsigned long no_pre_delete = (2UL<<num_parent);
 534        int i;
 535        unsigned long lno = 0;
 536        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 537        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 538        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 539        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 540        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 541        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 542
 543        if (result_deleted)
 544                return; /* result deleted */
 545
 546        while (1) {
 547                unsigned long hunk_end;
 548                unsigned long rlines;
 549                const char *hunk_comment = NULL;
 550                unsigned long null_context = 0;
 551
 552                while (lno <= cnt && !(sline[lno].flag & mark)) {
 553                        if (hunk_comment_line(sline[lno].bol))
 554                                hunk_comment = sline[lno].bol;
 555                        lno++;
 556                }
 557                if (cnt < lno)
 558                        break;
 559                else {
 560                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 561                                if (!(sline[hunk_end].flag & mark))
 562                                        break;
 563                }
 564                rlines = hunk_end - lno;
 565                if (cnt < hunk_end)
 566                        rlines--; /* pointing at the last delete hunk */
 567
 568                if (!context) {
 569                        /*
 570                         * Even when running with --unified=0, all
 571                         * lines in the hunk needs to be processed in
 572                         * the loop below in order to show the
 573                         * deletion recorded in lost_head.  However,
 574                         * we do not want to show the resulting line
 575                         * with all blank context markers in such a
 576                         * case.  Compensate.
 577                         */
 578                        unsigned long j;
 579                        for (j = lno; j < hunk_end; j++)
 580                                if (!(sline[j].flag & (mark-1)))
 581                                        null_context++;
 582                        rlines -= null_context;
 583                }
 584
 585                fputs(c_frag, stdout);
 586                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 587                for (i = 0; i < num_parent; i++)
 588                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 589                printf(" +%lu,%lu ", lno+1, rlines);
 590                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 591
 592                if (hunk_comment) {
 593                        int comment_end = 0;
 594                        for (i = 0; i < 40; i++) {
 595                                int ch = hunk_comment[i] & 0xff;
 596                                if (!ch || ch == '\n')
 597                                        break;
 598                                if (!isspace(ch))
 599                                    comment_end = i;
 600                        }
 601                        if (comment_end)
 602                                printf("%s%s %s%s", c_reset,
 603                                                    c_plain, c_reset,
 604                                                    c_func);
 605                        for (i = 0; i < comment_end; i++)
 606                                putchar(hunk_comment[i]);
 607                }
 608
 609                printf("%s\n", c_reset);
 610                while (lno < hunk_end) {
 611                        struct lline *ll;
 612                        int j;
 613                        unsigned long p_mask;
 614                        struct sline *sl = &sline[lno++];
 615                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 616                        while (ll) {
 617                                fputs(c_old, stdout);
 618                                for (j = 0; j < num_parent; j++) {
 619                                        if (ll->parent_map & (1UL<<j))
 620                                                putchar('-');
 621                                        else
 622                                                putchar(' ');
 623                                }
 624                                show_line_to_eol(ll->line, -1, c_reset);
 625                                ll = ll->next;
 626                        }
 627                        if (cnt < lno)
 628                                break;
 629                        p_mask = 1;
 630                        if (!(sl->flag & (mark-1))) {
 631                                /*
 632                                 * This sline was here to hang the
 633                                 * lost lines in front of it.
 634                                 */
 635                                if (!context)
 636                                        continue;
 637                                fputs(c_plain, stdout);
 638                        }
 639                        else
 640                                fputs(c_new, stdout);
 641                        for (j = 0; j < num_parent; j++) {
 642                                if (p_mask & sl->flag)
 643                                        putchar('+');
 644                                else
 645                                        putchar(' ');
 646                                p_mask <<= 1;
 647                        }
 648                        show_line_to_eol(sl->bol, sl->len, c_reset);
 649                }
 650        }
 651}
 652
 653static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 654                               int i, int j)
 655{
 656        /* We have already examined parent j and we know parent i
 657         * and parent j are the same, so reuse the combined result
 658         * of parent j for parent i.
 659         */
 660        unsigned long lno, imask, jmask;
 661        imask = (1UL<<i);
 662        jmask = (1UL<<j);
 663
 664        for (lno = 0; lno <= cnt; lno++) {
 665                struct lline *ll = sline->lost_head;
 666                sline->p_lno[i] = sline->p_lno[j];
 667                while (ll) {
 668                        if (ll->parent_map & jmask)
 669                                ll->parent_map |= imask;
 670                        ll = ll->next;
 671                }
 672                if (sline->flag & jmask)
 673                        sline->flag |= imask;
 674                sline++;
 675        }
 676        /* the overall size of the file (sline[cnt]) */
 677        sline->p_lno[i] = sline->p_lno[j];
 678}
 679
 680static void dump_quoted_path(const char *head,
 681                             const char *prefix,
 682                             const char *path,
 683                             const char *c_meta, const char *c_reset)
 684{
 685        static struct strbuf buf = STRBUF_INIT;
 686
 687        strbuf_reset(&buf);
 688        strbuf_addstr(&buf, c_meta);
 689        strbuf_addstr(&buf, head);
 690        quote_two_c_style(&buf, prefix, path, 0);
 691        strbuf_addstr(&buf, c_reset);
 692        puts(buf.buf);
 693}
 694
 695static void show_combined_header(struct combine_diff_path *elem,
 696                                 int num_parent,
 697                                 int dense,
 698                                 struct rev_info *rev,
 699                                 int mode_differs,
 700                                 int show_file_header)
 701{
 702        struct diff_options *opt = &rev->diffopt;
 703        int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 704        const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 705        const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 706        const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 707        const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 708        const char *abb;
 709        int added = 0;
 710        int deleted = 0;
 711        int i;
 712
 713        if (rev->loginfo && !rev->no_commit_id)
 714                show_log(rev);
 715
 716        dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 717                         "", elem->path, c_meta, c_reset);
 718        printf("%sindex ", c_meta);
 719        for (i = 0; i < num_parent; i++) {
 720                abb = find_unique_abbrev(elem->parent[i].sha1,
 721                                         abbrev);
 722                printf("%s%s", i ? "," : "", abb);
 723        }
 724        abb = find_unique_abbrev(elem->sha1, abbrev);
 725        printf("..%s%s\n", abb, c_reset);
 726
 727        if (mode_differs) {
 728                deleted = !elem->mode;
 729
 730                /* We say it was added if nobody had it */
 731                added = !deleted;
 732                for (i = 0; added && i < num_parent; i++)
 733                        if (elem->parent[i].status !=
 734                            DIFF_STATUS_ADDED)
 735                                added = 0;
 736                if (added)
 737                        printf("%snew file mode %06o",
 738                               c_meta, elem->mode);
 739                else {
 740                        if (deleted)
 741                                printf("%sdeleted file ", c_meta);
 742                        printf("mode ");
 743                        for (i = 0; i < num_parent; i++) {
 744                                printf("%s%06o", i ? "," : "",
 745                                       elem->parent[i].mode);
 746                        }
 747                        if (elem->mode)
 748                                printf("..%06o", elem->mode);
 749                }
 750                printf("%s\n", c_reset);
 751        }
 752
 753        if (!show_file_header)
 754                return;
 755
 756        if (added)
 757                dump_quoted_path("--- ", "", "/dev/null",
 758                                 c_meta, c_reset);
 759        else
 760                dump_quoted_path("--- ", a_prefix, elem->path,
 761                                 c_meta, c_reset);
 762        if (deleted)
 763                dump_quoted_path("+++ ", "", "/dev/null",
 764                                 c_meta, c_reset);
 765        else
 766                dump_quoted_path("+++ ", b_prefix, elem->path,
 767                                 c_meta, c_reset);
 768}
 769
 770static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 771                            int dense, int working_tree_file,
 772                            struct rev_info *rev)
 773{
 774        struct diff_options *opt = &rev->diffopt;
 775        unsigned long result_size, cnt, lno;
 776        int result_deleted = 0;
 777        char *result, *cp;
 778        struct sline *sline; /* survived lines */
 779        int mode_differs = 0;
 780        int i, show_hunks;
 781        mmfile_t result_file;
 782        struct userdiff_driver *userdiff;
 783        struct userdiff_driver *textconv = NULL;
 784        int is_binary;
 785
 786        context = opt->context;
 787        userdiff = userdiff_find_by_path(elem->path);
 788        if (!userdiff)
 789                userdiff = userdiff_find_by_name("default");
 790        if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV))
 791                textconv = userdiff_get_textconv(userdiff);
 792
 793        /* Read the result of merge first */
 794        if (!working_tree_file)
 795                result = grab_blob(elem->sha1, elem->mode, &result_size,
 796                                   textconv, elem->path);
 797        else {
 798                /* Used by diff-tree to read from the working tree */
 799                struct stat st;
 800                int fd = -1;
 801
 802                if (lstat(elem->path, &st) < 0)
 803                        goto deleted_file;
 804
 805                if (S_ISLNK(st.st_mode)) {
 806                        struct strbuf buf = STRBUF_INIT;
 807
 808                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
 809                                error("readlink(%s): %s", elem->path,
 810                                      strerror(errno));
 811                                return;
 812                        }
 813                        result_size = buf.len;
 814                        result = strbuf_detach(&buf, NULL);
 815                        elem->mode = canon_mode(st.st_mode);
 816                } else if (S_ISDIR(st.st_mode)) {
 817                        unsigned char sha1[20];
 818                        if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
 819                                result = grab_blob(elem->sha1, elem->mode,
 820                                                   &result_size, NULL, NULL);
 821                        else
 822                                result = grab_blob(sha1, elem->mode,
 823                                                   &result_size, NULL, NULL);
 824                } else if (textconv) {
 825                        struct diff_filespec *df = alloc_filespec(elem->path);
 826                        fill_filespec(df, null_sha1, 0, st.st_mode);
 827                        result_size = fill_textconv(textconv, df, &result);
 828                        free_filespec(df);
 829                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
 830                        size_t len = xsize_t(st.st_size);
 831                        ssize_t done;
 832                        int is_file, i;
 833
 834                        elem->mode = canon_mode(st.st_mode);
 835                        /* if symlinks don't work, assume symlink if all parents
 836                         * are symlinks
 837                         */
 838                        is_file = has_symlinks;
 839                        for (i = 0; !is_file && i < num_parent; i++)
 840                                is_file = !S_ISLNK(elem->parent[i].mode);
 841                        if (!is_file)
 842                                elem->mode = canon_mode(S_IFLNK);
 843
 844                        result_size = len;
 845                        result = xmalloc(len + 1);
 846
 847                        done = read_in_full(fd, result, len);
 848                        if (done < 0)
 849                                die_errno("read error '%s'", elem->path);
 850                        else if (done < len)
 851                                die("early EOF '%s'", elem->path);
 852
 853                        result[len] = 0;
 854
 855                        /* If not a fake symlink, apply filters, e.g. autocrlf */
 856                        if (is_file) {
 857                                struct strbuf buf = STRBUF_INIT;
 858
 859                                if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 860                                        free(result);
 861                                        result = strbuf_detach(&buf, &len);
 862                                        result_size = len;
 863                                }
 864                        }
 865                }
 866                else {
 867                deleted_file:
 868                        result_deleted = 1;
 869                        result_size = 0;
 870                        elem->mode = 0;
 871                        result = xcalloc(1, 1);
 872                }
 873
 874                if (0 <= fd)
 875                        close(fd);
 876        }
 877
 878        for (i = 0; i < num_parent; i++) {
 879                if (elem->parent[i].mode != elem->mode) {
 880                        mode_differs = 1;
 881                        break;
 882                }
 883        }
 884
 885        if (textconv)
 886                is_binary = 0;
 887        else if (userdiff->binary != -1)
 888                is_binary = userdiff->binary;
 889        else {
 890                is_binary = buffer_is_binary(result, result_size);
 891                for (i = 0; !is_binary && i < num_parent; i++) {
 892                        char *buf;
 893                        unsigned long size;
 894                        buf = grab_blob(elem->parent[i].sha1,
 895                                        elem->parent[i].mode,
 896                                        &size, NULL, NULL);
 897                        if (buffer_is_binary(buf, size))
 898                                is_binary = 1;
 899                        free(buf);
 900                }
 901        }
 902        if (is_binary) {
 903                show_combined_header(elem, num_parent, dense, rev,
 904                                     mode_differs, 0);
 905                printf("Binary files differ\n");
 906                free(result);
 907                return;
 908        }
 909
 910        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 911                if (*cp == '\n')
 912                        cnt++;
 913        }
 914        if (result_size && result[result_size-1] != '\n')
 915                cnt++; /* incomplete line */
 916
 917        sline = xcalloc(cnt+2, sizeof(*sline));
 918        sline[0].bol = result;
 919        for (lno = 0; lno <= cnt + 1; lno++) {
 920                sline[lno].lost_tail = &sline[lno].lost_head;
 921                sline[lno].flag = 0;
 922        }
 923        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 924                if (*cp == '\n') {
 925                        sline[lno].len = cp - sline[lno].bol;
 926                        lno++;
 927                        if (lno < cnt)
 928                                sline[lno].bol = cp + 1;
 929                }
 930        }
 931        if (result_size && result[result_size-1] != '\n')
 932                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 933
 934        result_file.ptr = result;
 935        result_file.size = result_size;
 936
 937        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 938         * for deletion hunk at the end.
 939         */
 940        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 941        for (lno = 0; lno <= cnt; lno++)
 942                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 943
 944        for (i = 0; i < num_parent; i++) {
 945                int j;
 946                for (j = 0; j < i; j++) {
 947                        if (!hashcmp(elem->parent[i].sha1,
 948                                     elem->parent[j].sha1)) {
 949                                reuse_combine_diff(sline, cnt, i, j);
 950                                break;
 951                        }
 952                }
 953                if (i <= j)
 954                        combine_diff(elem->parent[i].sha1,
 955                                     elem->parent[i].mode,
 956                                     &result_file, sline,
 957                                     cnt, i, num_parent, result_deleted,
 958                                     textconv, elem->path);
 959        }
 960
 961        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 962
 963        if (show_hunks || mode_differs || working_tree_file) {
 964                show_combined_header(elem, num_parent, dense, rev,
 965                                     mode_differs, 1);
 966                dump_sline(sline, cnt, num_parent,
 967                           opt->use_color, result_deleted);
 968        }
 969        free(result);
 970
 971        for (lno = 0; lno < cnt; lno++) {
 972                if (sline[lno].lost_head) {
 973                        struct lline *ll = sline[lno].lost_head;
 974                        while (ll) {
 975                                struct lline *tmp = ll;
 976                                ll = ll->next;
 977                                free(tmp);
 978                        }
 979                }
 980        }
 981        free(sline[0].p_lno);
 982        free(sline);
 983}
 984
 985#define COLONS "::::::::::::::::::::::::::::::::"
 986
 987static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 988{
 989        struct diff_options *opt = &rev->diffopt;
 990        int i, offset;
 991        const char *prefix;
 992        int line_termination, inter_name_termination;
 993
 994        line_termination = opt->line_termination;
 995        inter_name_termination = '\t';
 996        if (!line_termination)
 997                inter_name_termination = 0;
 998
 999        if (rev->loginfo && !rev->no_commit_id)
1000                show_log(rev);
1001
1002        if (opt->output_format & DIFF_FORMAT_RAW) {
1003                offset = strlen(COLONS) - num_parent;
1004                if (offset < 0)
1005                        offset = 0;
1006                prefix = COLONS + offset;
1007
1008                /* Show the modes */
1009                for (i = 0; i < num_parent; i++) {
1010                        printf("%s%06o", prefix, p->parent[i].mode);
1011                        prefix = " ";
1012                }
1013                printf("%s%06o", prefix, p->mode);
1014
1015                /* Show sha1's */
1016                for (i = 0; i < num_parent; i++)
1017                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
1018                                                         opt->abbrev));
1019                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
1020        }
1021
1022        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1023                for (i = 0; i < num_parent; i++)
1024                        putchar(p->parent[i].status);
1025                putchar(inter_name_termination);
1026        }
1027
1028        write_name_quoted(p->path, stdout, line_termination);
1029}
1030
1031/*
1032 * The result (p->elem) is from the working tree and their
1033 * parents are typically from multiple stages during a merge
1034 * (i.e. diff-files) or the state in HEAD and in the index
1035 * (i.e. diff-index).
1036 */
1037void show_combined_diff(struct combine_diff_path *p,
1038                       int num_parent,
1039                       int dense,
1040                       struct rev_info *rev)
1041{
1042        struct diff_options *opt = &rev->diffopt;
1043        if (!p->len)
1044                return;
1045        if (opt->output_format & (DIFF_FORMAT_RAW |
1046                                  DIFF_FORMAT_NAME |
1047                                  DIFF_FORMAT_NAME_STATUS))
1048                show_raw_diff(p, num_parent, rev);
1049        else if (opt->output_format & DIFF_FORMAT_PATCH)
1050                show_patch_diff(p, num_parent, dense, 1, rev);
1051}
1052
1053static void free_combined_pair(struct diff_filepair *pair)
1054{
1055        free(pair->two);
1056        free(pair);
1057}
1058
1059/*
1060 * A combine_diff_path expresses N parents on the LHS against 1 merge
1061 * result. Synthesize a diff_filepair that has N entries on the "one"
1062 * side and 1 entry on the "two" side.
1063 *
1064 * In the future, we might want to add more data to combine_diff_path
1065 * so that we can fill fields we are ignoring (most notably, size) here,
1066 * but currently nobody uses it, so this should suffice for now.
1067 */
1068static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1069                                           int num_parent)
1070{
1071        int i;
1072        struct diff_filepair *pair;
1073        struct diff_filespec *pool;
1074
1075        pair = xmalloc(sizeof(*pair));
1076        pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec));
1077        pair->one = pool + 1;
1078        pair->two = pool;
1079
1080        for (i = 0; i < num_parent; i++) {
1081                pair->one[i].path = p->path;
1082                pair->one[i].mode = p->parent[i].mode;
1083                hashcpy(pair->one[i].sha1, p->parent[i].sha1);
1084                pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
1085                pair->one[i].has_more_entries = 1;
1086        }
1087        pair->one[num_parent - 1].has_more_entries = 0;
1088
1089        pair->two->path = p->path;
1090        pair->two->mode = p->mode;
1091        hashcpy(pair->two->sha1, p->sha1);
1092        pair->two->sha1_valid = !is_null_sha1(p->sha1);
1093        return pair;
1094}
1095
1096static void handle_combined_callback(struct diff_options *opt,
1097                                     struct combine_diff_path *paths,
1098                                     int num_parent,
1099                                     int num_paths)
1100{
1101        struct combine_diff_path *p;
1102        struct diff_queue_struct q;
1103        int i;
1104
1105        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1106        q.alloc = num_paths;
1107        q.nr = num_paths;
1108        for (i = 0, p = paths; p; p = p->next) {
1109                if (!p->len)
1110                        continue;
1111                q.queue[i++] = combined_pair(p, num_parent);
1112        }
1113        opt->format_callback(&q, opt, opt->format_callback_data);
1114        for (i = 0; i < num_paths; i++)
1115                free_combined_pair(q.queue[i]);
1116        free(q.queue);
1117}
1118
1119void diff_tree_combined(const unsigned char *sha1,
1120                        const struct sha1_array *parents,
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, num_parent = parents->nr;
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(parents->sha1[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 struct commit *commit, int dense,
1200                              struct rev_info *rev)
1201{
1202        struct commit_list *parent = commit->parents;
1203        struct sha1_array parents = SHA1_ARRAY_INIT;
1204
1205        while (parent) {
1206                sha1_array_append(&parents, parent->item->object.sha1);
1207                parent = parent->next;
1208        }
1209        diff_tree_combined(commit->object.sha1, &parents, dense, rev);
1210        sha1_array_clear(&parents);
1211}