Andrew's git / gitweb.git / diff-lib.c
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diff-lib.con commit diff: support reading a file from stdin via "-" (5332b2a)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "revision.h"
  10#include "cache-tree.h"
  11#include "path-list.h"
  12
  13/*
  14 * diff-files
  15 */
  16
  17static int read_directory(const char *path, struct path_list *list)
  18{
  19        DIR *dir;
  20        struct dirent *e;
  21
  22        if (!(dir = opendir(path)))
  23                return error("Could not open directory %s", path);
  24
  25        while ((e = readdir(dir)))
  26                if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
  27                        path_list_insert(xstrdup(e->d_name), list);
  28
  29        closedir(dir);
  30        return 0;
  31}
  32
  33static int queue_diff(struct diff_options *o,
  34                const char *name1, const char *name2)
  35{
  36        struct stat st;
  37        int mode1 = 0, mode2 = 0;
  38
  39        if (name1) {
  40                if (!strcmp(name1, "-"))
  41                        mode1 = 0644;
  42                else if (stat(name1, &st))
  43                        return error("Could not access '%s'", name1);
  44                else
  45                        mode1 = st.st_mode;
  46        }
  47        if (name2) {
  48                if (!strcmp(name2, "-"))
  49                        mode2 = 0644;
  50                else if (stat(name2, &st))
  51                        return error("Could not access '%s'", name2);
  52                else
  53                        mode2 = st.st_mode;
  54        }
  55
  56        if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
  57                return error("file/directory conflict: %s, %s", name1, name2);
  58
  59        if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
  60                char buffer1[PATH_MAX], buffer2[PATH_MAX];
  61                struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
  62                int len1 = 0, len2 = 0, i1, i2, ret = 0;
  63
  64                if (name1 && read_directory(name1, &p1))
  65                        return -1;
  66                if (name2 && read_directory(name2, &p2)) {
  67                        path_list_clear(&p1, 0);
  68                        return -1;
  69                }
  70
  71                if (name1) {
  72                        len1 = strlen(name1);
  73                        if (len1 > 0 && name1[len1 - 1] == '/')
  74                                len1--;
  75                        memcpy(buffer1, name1, len1);
  76                        buffer1[len1++] = '/';
  77                }
  78
  79                if (name2) {
  80                        len2 = strlen(name2);
  81                        if (len2 > 0 && name2[len2 - 1] == '/')
  82                                len2--;
  83                        memcpy(buffer2, name2, len2);
  84                        buffer2[len2++] = '/';
  85                }
  86
  87                for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
  88                        const char *n1, *n2;
  89                        int comp;
  90
  91                        if (i1 == p1.nr)
  92                                comp = 1;
  93                        else if (i2 == p2.nr)
  94                                comp = -1;
  95                        else
  96                                comp = strcmp(p1.items[i1].path,
  97                                        p2.items[i2].path);
  98
  99                        if (comp > 0)
 100                                n1 = NULL;
 101                        else {
 102                                n1 = buffer1;
 103                                strncpy(buffer1 + len1, p1.items[i1++].path,
 104                                                PATH_MAX - len1);
 105                        }
 106
 107                        if (comp < 0)
 108                                n2 = NULL;
 109                        else {
 110                                n2 = buffer2;
 111                                strncpy(buffer2 + len2, p2.items[i2++].path,
 112                                                PATH_MAX - len2);
 113                        }
 114
 115                        ret = queue_diff(o, n1, n2);
 116                }
 117                path_list_clear(&p1, 0);
 118                path_list_clear(&p2, 0);
 119
 120                return ret;
 121        } else {
 122                struct diff_filespec *d1, *d2;
 123
 124                if (o->reverse_diff) {
 125                        unsigned tmp;
 126                        const char *tmp_c;
 127                        tmp = mode1; mode1 = mode2; mode2 = tmp;
 128                        tmp_c = name1; name1 = name2; name2 = tmp_c;
 129                }
 130
 131                if (!name1)
 132                        name1 = "/dev/null";
 133                if (!name2)
 134                        name2 = "/dev/null";
 135                d1 = alloc_filespec(name1);
 136                d2 = alloc_filespec(name2);
 137                fill_filespec(d1, null_sha1, mode1);
 138                fill_filespec(d2, null_sha1, mode2);
 139
 140                diff_queue(&diff_queued_diff, d1, d2);
 141                return 0;
 142        }
 143}
 144
 145static int is_in_index(const char *path)
 146{
 147        int len = strlen(path);
 148        int pos = cache_name_pos(path, len);
 149        char c;
 150
 151        if (pos < 0)
 152                return 0;
 153        if (strncmp(active_cache[pos]->name, path, len))
 154                return 0;
 155        c = active_cache[pos]->name[len];
 156        return c == '\0' || c == '/';
 157}
 158
 159static int handle_diff_files_args(struct rev_info *revs,
 160                int argc, const char **argv, int *silent)
 161{
 162        *silent = 0;
 163
 164        /* revs->max_count == -2 means --no-index */
 165        while (1 < argc && argv[1][0] == '-') {
 166                if (!strcmp(argv[1], "--base"))
 167                        revs->max_count = 1;
 168                else if (!strcmp(argv[1], "--ours"))
 169                        revs->max_count = 2;
 170                else if (!strcmp(argv[1], "--theirs"))
 171                        revs->max_count = 3;
 172                else if (!strcmp(argv[1], "-n") ||
 173                                !strcmp(argv[1], "--no-index"))
 174                        revs->max_count = -2;
 175                else if (!strcmp(argv[1], "-q"))
 176                        *silent = 1;
 177                else
 178                        return error("invalid option: %s", argv[1]);
 179                argv++; argc--;
 180        }
 181
 182        if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
 183                /*
 184                 * If two files are specified, and at least one is untracked,
 185                 * default to no-index.
 186                 */
 187                read_cache();
 188                if (!is_in_index(revs->diffopt.paths[0]) ||
 189                                        !is_in_index(revs->diffopt.paths[1]))
 190                        revs->max_count = -2;
 191        }
 192
 193        /*
 194         * Make sure there are NO revision (i.e. pending object) parameter,
 195         * rev.max_count is reasonable (0 <= n <= 3),
 196         * there is no other revision filtering parameters.
 197         */
 198        if (revs->pending.nr || revs->max_count > 3 ||
 199            revs->min_age != -1 || revs->max_age != -1)
 200                return error("no revision allowed with diff-files");
 201
 202        if (revs->max_count == -1 &&
 203            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 204                revs->combine_merges = revs->dense_combined_merges = 1;
 205
 206        return 0;
 207}
 208
 209static int is_outside_repo(const char *path, int nongit, const char *prefix)
 210{
 211        int i;
 212        if (nongit || !strcmp(path, "-") || path[0] == '/')
 213                return 1;
 214        if (prefixcmp(path, "../"))
 215                return 0;
 216        if (!prefix)
 217                return 1;
 218        for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 219                while (i > 0 && prefix[i - 1] != '/')
 220                        i--;
 221                if (--i < 0)
 222                        return 1;
 223                path += 3;
 224        }
 225        return 0;
 226}
 227
 228int setup_diff_no_index(struct rev_info *revs,
 229                int argc, const char ** argv, int nongit, const char *prefix)
 230{
 231        int i;
 232        for (i = 1; i < argc; i++)
 233                if (argv[i][0] != '-' || argv[i][1] == '\0')
 234                        break;
 235                else if (!strcmp(argv[i], "--")) {
 236                        i++;
 237                        break;
 238                } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 239                        i = argc - 3;
 240                        break;
 241                }
 242        if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 243                                !is_outside_repo(argv[i], nongit, prefix)))
 244                return -1;
 245
 246        diff_setup(&revs->diffopt);
 247        for (i = 1; i < argc - 2; )
 248                if (!strcmp(argv[i], "--no-index"))
 249                        i++;
 250                else {
 251                        int j = diff_opt_parse(&revs->diffopt,
 252                                        argv + i, argc - i);
 253                        if (!j)
 254                                die("invalid diff option/value: %s", argv[i]);
 255                        i += j;
 256                }
 257
 258        if (prefix) {
 259                int len = strlen(prefix);
 260
 261                revs->diffopt.paths = xcalloc(2, sizeof(char*));
 262                for (i = 0; i < 2; i++) {
 263                        const char *p;
 264                        p = prefix_filename(prefix, len, argv[argc - 2 + i]);
 265                        revs->diffopt.paths[i] = xstrdup(p);
 266                }
 267        }
 268        else
 269                revs->diffopt.paths = argv + argc - 2;
 270        revs->diffopt.nr_paths = 2;
 271        revs->max_count = -2;
 272        return 0;
 273}
 274
 275int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 276{
 277        int silent_on_removed;
 278
 279        if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
 280                return -1;
 281
 282        if (revs->max_count == -2) {
 283                if (revs->diffopt.nr_paths != 2)
 284                        return error("need two files/directories with --no-index");
 285                if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 286                                revs->diffopt.paths[1]))
 287                        return -1;
 288                diffcore_std(&revs->diffopt);
 289                diff_flush(&revs->diffopt);
 290                /*
 291                 * The return code for --no-index imitates diff(1):
 292                 * 0 = no changes, 1 = changes, else error
 293                 */
 294                return revs->diffopt.found_changes;
 295        }
 296
 297        if (read_cache() < 0) {
 298                perror("read_cache");
 299                return -1;
 300        }
 301        return run_diff_files(revs, silent_on_removed);
 302}
 303
 304int run_diff_files(struct rev_info *revs, int silent_on_removed)
 305{
 306        int entries, i;
 307        int diff_unmerged_stage = revs->max_count;
 308
 309        if (diff_unmerged_stage < 0)
 310                diff_unmerged_stage = 2;
 311        entries = active_nr;
 312        for (i = 0; i < entries; i++) {
 313                struct stat st;
 314                unsigned int oldmode, newmode;
 315                struct cache_entry *ce = active_cache[i];
 316                int changed;
 317
 318                if (!ce_path_match(ce, revs->prune_data))
 319                        continue;
 320
 321                if (ce_stage(ce)) {
 322                        struct combine_diff_path *dpath;
 323                        int num_compare_stages = 0;
 324                        size_t path_len;
 325
 326                        path_len = ce_namelen(ce);
 327
 328                        dpath = xmalloc(combine_diff_path_size(5, path_len));
 329                        dpath->path = (char *) &(dpath->parent[5]);
 330
 331                        dpath->next = NULL;
 332                        dpath->len = path_len;
 333                        memcpy(dpath->path, ce->name, path_len);
 334                        dpath->path[path_len] = '\0';
 335                        hashclr(dpath->sha1);
 336                        memset(&(dpath->parent[0]), 0,
 337                               sizeof(struct combine_diff_parent)*5);
 338
 339                        if (lstat(ce->name, &st) < 0) {
 340                                if (errno != ENOENT && errno != ENOTDIR) {
 341                                        perror(ce->name);
 342                                        continue;
 343                                }
 344                                if (silent_on_removed)
 345                                        continue;
 346                        }
 347                        else
 348                                dpath->mode = canon_mode(st.st_mode);
 349
 350                        while (i < entries) {
 351                                struct cache_entry *nce = active_cache[i];
 352                                int stage;
 353
 354                                if (strcmp(ce->name, nce->name))
 355                                        break;
 356
 357                                /* Stage #2 (ours) is the first parent,
 358                                 * stage #3 (theirs) is the second.
 359                                 */
 360                                stage = ce_stage(nce);
 361                                if (2 <= stage) {
 362                                        int mode = ntohl(nce->ce_mode);
 363                                        num_compare_stages++;
 364                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 365                                        dpath->parent[stage-2].mode =
 366                                                canon_mode(mode);
 367                                        dpath->parent[stage-2].status =
 368                                                DIFF_STATUS_MODIFIED;
 369                                }
 370
 371                                /* diff against the proper unmerged stage */
 372                                if (stage == diff_unmerged_stage)
 373                                        ce = nce;
 374                                i++;
 375                        }
 376                        /*
 377                         * Compensate for loop update
 378                         */
 379                        i--;
 380
 381                        if (revs->combine_merges && num_compare_stages == 2) {
 382                                show_combined_diff(dpath, 2,
 383                                                   revs->dense_combined_merges,
 384                                                   revs);
 385                                free(dpath);
 386                                continue;
 387                        }
 388                        free(dpath);
 389                        dpath = NULL;
 390
 391                        /*
 392                         * Show the diff for the 'ce' if we found the one
 393                         * from the desired stage.
 394                         */
 395                        diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 396                        if (ce_stage(ce) != diff_unmerged_stage)
 397                                continue;
 398                }
 399
 400                if (lstat(ce->name, &st) < 0) {
 401                        if (errno != ENOENT && errno != ENOTDIR) {
 402                                perror(ce->name);
 403                                continue;
 404                        }
 405                        if (silent_on_removed)
 406                                continue;
 407                        diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 408                                       ce->sha1, ce->name, NULL);
 409                        continue;
 410                }
 411                changed = ce_match_stat(ce, &st, 0);
 412                if (!changed && !revs->diffopt.find_copies_harder)
 413                        continue;
 414                oldmode = ntohl(ce->ce_mode);
 415
 416                newmode = canon_mode(st.st_mode);
 417                if (!trust_executable_bit &&
 418                    S_ISREG(newmode) && S_ISREG(oldmode) &&
 419                    ((newmode ^ oldmode) == 0111))
 420                        newmode = oldmode;
 421                diff_change(&revs->diffopt, oldmode, newmode,
 422                            ce->sha1, (changed ? null_sha1 : ce->sha1),
 423                            ce->name, NULL);
 424
 425        }
 426        diffcore_std(&revs->diffopt);
 427        diff_flush(&revs->diffopt);
 428        return 0;
 429}
 430
 431/*
 432 * diff-index
 433 */
 434
 435/* A file entry went away or appeared */
 436static void diff_index_show_file(struct rev_info *revs,
 437                                 const char *prefix,
 438                                 struct cache_entry *ce,
 439                                 unsigned char *sha1, unsigned int mode)
 440{
 441        diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 442                       sha1, ce->name, NULL);
 443}
 444
 445static int get_stat_data(struct cache_entry *ce,
 446                         unsigned char **sha1p,
 447                         unsigned int *modep,
 448                         int cached, int match_missing)
 449{
 450        unsigned char *sha1 = ce->sha1;
 451        unsigned int mode = ce->ce_mode;
 452
 453        if (!cached) {
 454                static unsigned char no_sha1[20];
 455                int changed;
 456                struct stat st;
 457                if (lstat(ce->name, &st) < 0) {
 458                        if (errno == ENOENT && match_missing) {
 459                                *sha1p = sha1;
 460                                *modep = mode;
 461                                return 0;
 462                        }
 463                        return -1;
 464                }
 465                changed = ce_match_stat(ce, &st, 0);
 466                if (changed) {
 467                        mode = ce_mode_from_stat(ce, st.st_mode);
 468                        sha1 = no_sha1;
 469                }
 470        }
 471
 472        *sha1p = sha1;
 473        *modep = mode;
 474        return 0;
 475}
 476
 477static void show_new_file(struct rev_info *revs,
 478                          struct cache_entry *new,
 479                          int cached, int match_missing)
 480{
 481        unsigned char *sha1;
 482        unsigned int mode;
 483
 484        /* New file in the index: it might actually be different in
 485         * the working copy.
 486         */
 487        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 488                return;
 489
 490        diff_index_show_file(revs, "+", new, sha1, mode);
 491}
 492
 493static int show_modified(struct rev_info *revs,
 494                         struct cache_entry *old,
 495                         struct cache_entry *new,
 496                         int report_missing,
 497                         int cached, int match_missing)
 498{
 499        unsigned int mode, oldmode;
 500        unsigned char *sha1;
 501
 502        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 503                if (report_missing)
 504                        diff_index_show_file(revs, "-", old,
 505                                             old->sha1, old->ce_mode);
 506                return -1;
 507        }
 508
 509        if (revs->combine_merges && !cached &&
 510            (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 511                struct combine_diff_path *p;
 512                int pathlen = ce_namelen(new);
 513
 514                p = xmalloc(combine_diff_path_size(2, pathlen));
 515                p->path = (char *) &p->parent[2];
 516                p->next = NULL;
 517                p->len = pathlen;
 518                memcpy(p->path, new->name, pathlen);
 519                p->path[pathlen] = 0;
 520                p->mode = ntohl(mode);
 521                hashclr(p->sha1);
 522                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 523                p->parent[0].status = DIFF_STATUS_MODIFIED;
 524                p->parent[0].mode = ntohl(new->ce_mode);
 525                hashcpy(p->parent[0].sha1, new->sha1);
 526                p->parent[1].status = DIFF_STATUS_MODIFIED;
 527                p->parent[1].mode = ntohl(old->ce_mode);
 528                hashcpy(p->parent[1].sha1, old->sha1);
 529                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 530                free(p);
 531                return 0;
 532        }
 533
 534        oldmode = old->ce_mode;
 535        if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 536            !revs->diffopt.find_copies_harder)
 537                return 0;
 538
 539        mode = ntohl(mode);
 540        oldmode = ntohl(oldmode);
 541
 542        diff_change(&revs->diffopt, oldmode, mode,
 543                    old->sha1, sha1, old->name, NULL);
 544        return 0;
 545}
 546
 547static int diff_cache(struct rev_info *revs,
 548                      struct cache_entry **ac, int entries,
 549                      const char **pathspec,
 550                      int cached, int match_missing)
 551{
 552        while (entries) {
 553                struct cache_entry *ce = *ac;
 554                int same = (entries > 1) && ce_same_name(ce, ac[1]);
 555
 556                if (!ce_path_match(ce, pathspec))
 557                        goto skip_entry;
 558
 559                switch (ce_stage(ce)) {
 560                case 0:
 561                        /* No stage 1 entry? That means it's a new file */
 562                        if (!same) {
 563                                show_new_file(revs, ce, cached, match_missing);
 564                                break;
 565                        }
 566                        /* Show difference between old and new */
 567                        show_modified(revs, ac[1], ce, 1,
 568                                      cached, match_missing);
 569                        break;
 570                case 1:
 571                        /* No stage 3 (merge) entry?
 572                         * That means it's been deleted.
 573                         */
 574                        if (!same) {
 575                                diff_index_show_file(revs, "-", ce,
 576                                                     ce->sha1, ce->ce_mode);
 577                                break;
 578                        }
 579                        /* We come here with ce pointing at stage 1
 580                         * (original tree) and ac[1] pointing at stage
 581                         * 3 (unmerged).  show-modified with
 582                         * report-missing set to false does not say the
 583                         * file is deleted but reports true if work
 584                         * tree does not have it, in which case we
 585                         * fall through to report the unmerged state.
 586                         * Otherwise, we show the differences between
 587                         * the original tree and the work tree.
 588                         */
 589                        if (!cached &&
 590                            !show_modified(revs, ce, ac[1], 0,
 591                                           cached, match_missing))
 592                                break;
 593                        diff_unmerge(&revs->diffopt, ce->name,
 594                                     ntohl(ce->ce_mode), ce->sha1);
 595                        break;
 596                case 3:
 597                        diff_unmerge(&revs->diffopt, ce->name,
 598                                     0, null_sha1);
 599                        break;
 600
 601                default:
 602                        die("impossible cache entry stage");
 603                }
 604
 605skip_entry:
 606                /*
 607                 * Ignore all the different stages for this file,
 608                 * we've handled the relevant cases now.
 609                 */
 610                do {
 611                        ac++;
 612                        entries--;
 613                } while (entries && ce_same_name(ce, ac[0]));
 614        }
 615        return 0;
 616}
 617
 618/*
 619 * This turns all merge entries into "stage 3". That guarantees that
 620 * when we read in the new tree (into "stage 1"), we won't lose sight
 621 * of the fact that we had unmerged entries.
 622 */
 623static void mark_merge_entries(void)
 624{
 625        int i;
 626        for (i = 0; i < active_nr; i++) {
 627                struct cache_entry *ce = active_cache[i];
 628                if (!ce_stage(ce))
 629                        continue;
 630                ce->ce_flags |= htons(CE_STAGEMASK);
 631        }
 632}
 633
 634int run_diff_index(struct rev_info *revs, int cached)
 635{
 636        int ret;
 637        struct object *ent;
 638        struct tree *tree;
 639        const char *tree_name;
 640        int match_missing = 0;
 641
 642        /* 
 643         * Backward compatibility wart - "diff-index -m" does
 644         * not mean "do not ignore merges", but totally different.
 645         */
 646        if (!revs->ignore_merges)
 647                match_missing = 1;
 648
 649        mark_merge_entries();
 650
 651        ent = revs->pending.objects[0].item;
 652        tree_name = revs->pending.objects[0].name;
 653        tree = parse_tree_indirect(ent->sha1);
 654        if (!tree)
 655                return error("bad tree object %s", tree_name);
 656        if (read_tree(tree, 1, revs->prune_data))
 657                return error("unable to read tree object %s", tree_name);
 658        ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 659                         cached, match_missing);
 660        diffcore_std(&revs->diffopt);
 661        diff_flush(&revs->diffopt);
 662        return ret;
 663}
 664
 665int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 666{
 667        struct tree *tree;
 668        struct rev_info revs;
 669        int i;
 670        struct cache_entry **dst;
 671        struct cache_entry *last = NULL;
 672
 673        /*
 674         * This is used by git-blame to run diff-cache internally;
 675         * it potentially needs to repeatedly run this, so we will
 676         * start by removing the higher order entries the last round
 677         * left behind.
 678         */
 679        dst = active_cache;
 680        for (i = 0; i < active_nr; i++) {
 681                struct cache_entry *ce = active_cache[i];
 682                if (ce_stage(ce)) {
 683                        if (last && !strcmp(ce->name, last->name))
 684                                continue;
 685                        cache_tree_invalidate_path(active_cache_tree,
 686                                                   ce->name);
 687                        last = ce;
 688                        ce->ce_mode = 0;
 689                        ce->ce_flags &= ~htons(CE_STAGEMASK);
 690                }
 691                *dst++ = ce;
 692        }
 693        active_nr = dst - active_cache;
 694
 695        init_revisions(&revs, NULL);
 696        revs.prune_data = opt->paths;
 697        tree = parse_tree_indirect(tree_sha1);
 698        if (!tree)
 699                die("bad tree object %s", sha1_to_hex(tree_sha1));
 700        if (read_tree(tree, 1, opt->paths))
 701                return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 702        return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 703                          1, 0);
 704}