diff-lib.con commit Merge branch 'mh/avoid-rewriting-packed-refs' into maint (02abc6b)
   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 "unpack-trees.h"
  12#include "refs.h"
  13#include "submodule.h"
  14#include "dir.h"
  15
  16/*
  17 * diff-files
  18 */
  19
  20/*
  21 * Has the work tree entity been removed?
  22 *
  23 * Return 1 if it was removed from the work tree, 0 if an entity to be
  24 * compared with the cache entry ce still exists (the latter includes
  25 * the case where a directory that is not a submodule repository
  26 * exists for ce that is a submodule -- it is a submodule that is not
  27 * checked out).  Return negative for an error.
  28 */
  29static int check_removed(const struct cache_entry *ce, struct stat *st)
  30{
  31        if (lstat(ce->name, st) < 0) {
  32                if (!is_missing_file_error(errno))
  33                        return -1;
  34                return 1;
  35        }
  36        if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  37                return 1;
  38        if (S_ISDIR(st->st_mode)) {
  39                unsigned char sub[20];
  40
  41                /*
  42                 * If ce is already a gitlink, we can have a plain
  43                 * directory (i.e. the submodule is not checked out),
  44                 * or a checked out submodule.  Either case this is not
  45                 * a case where something was removed from the work tree,
  46                 * so we will return 0.
  47                 *
  48                 * Otherwise, if the directory is not a submodule
  49                 * repository, that means ce which was a blob turned into
  50                 * a directory --- the blob was removed!
  51                 */
  52                if (!S_ISGITLINK(ce->ce_mode) &&
  53                    resolve_gitlink_ref(ce->name, "HEAD", sub))
  54                        return 1;
  55        }
  56        return 0;
  57}
  58
  59/*
  60 * Has a file changed or has a submodule new commits or a dirty work tree?
  61 *
  62 * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  63 * option is set, the caller does not only want to know if a submodule is
  64 * modified at all but wants to know all the conditions that are met (new
  65 * commits, untracked content and/or modified content).
  66 */
  67static int match_stat_with_submodule(struct diff_options *diffopt,
  68                                     const struct cache_entry *ce,
  69                                     struct stat *st, unsigned ce_option,
  70                                     unsigned *dirty_submodule)
  71{
  72        int changed = ce_match_stat(ce, st, ce_option);
  73        if (S_ISGITLINK(ce->ce_mode)) {
  74                unsigned orig_flags = diffopt->flags;
  75                if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
  76                        set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  77                if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
  78                        changed = 0;
  79                else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
  80                    && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
  81                        *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
  82                diffopt->flags = orig_flags;
  83        }
  84        return changed;
  85}
  86
  87int run_diff_files(struct rev_info *revs, unsigned int option)
  88{
  89        int entries, i;
  90        int diff_unmerged_stage = revs->max_count;
  91        unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  92                              ? CE_MATCH_RACY_IS_DIRTY : 0);
  93
  94        diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  95
  96        if (diff_unmerged_stage < 0)
  97                diff_unmerged_stage = 2;
  98        entries = active_nr;
  99        for (i = 0; i < entries; i++) {
 100                unsigned int oldmode, newmode;
 101                struct cache_entry *ce = active_cache[i];
 102                int changed;
 103                unsigned dirty_submodule = 0;
 104                const struct object_id *old_oid, *new_oid;
 105
 106                if (diff_can_quit_early(&revs->diffopt))
 107                        break;
 108
 109                if (!ce_path_match(ce, &revs->prune_data, NULL))
 110                        continue;
 111
 112                if (ce_stage(ce)) {
 113                        struct combine_diff_path *dpath;
 114                        struct diff_filepair *pair;
 115                        unsigned int wt_mode = 0;
 116                        int num_compare_stages = 0;
 117                        size_t path_len;
 118                        struct stat st;
 119
 120                        path_len = ce_namelen(ce);
 121
 122                        dpath = xmalloc(combine_diff_path_size(5, path_len));
 123                        dpath->path = (char *) &(dpath->parent[5]);
 124
 125                        dpath->next = NULL;
 126                        memcpy(dpath->path, ce->name, path_len);
 127                        dpath->path[path_len] = '\0';
 128                        oidclr(&dpath->oid);
 129                        memset(&(dpath->parent[0]), 0,
 130                               sizeof(struct combine_diff_parent)*5);
 131
 132                        changed = check_removed(ce, &st);
 133                        if (!changed)
 134                                wt_mode = ce_mode_from_stat(ce, st.st_mode);
 135                        else {
 136                                if (changed < 0) {
 137                                        perror(ce->name);
 138                                        continue;
 139                                }
 140                                wt_mode = 0;
 141                        }
 142                        dpath->mode = wt_mode;
 143
 144                        while (i < entries) {
 145                                struct cache_entry *nce = active_cache[i];
 146                                int stage;
 147
 148                                if (strcmp(ce->name, nce->name))
 149                                        break;
 150
 151                                /* Stage #2 (ours) is the first parent,
 152                                 * stage #3 (theirs) is the second.
 153                                 */
 154                                stage = ce_stage(nce);
 155                                if (2 <= stage) {
 156                                        int mode = nce->ce_mode;
 157                                        num_compare_stages++;
 158                                        oidcpy(&dpath->parent[stage - 2].oid,
 159                                               &nce->oid);
 160                                        dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 161                                        dpath->parent[stage-2].status =
 162                                                DIFF_STATUS_MODIFIED;
 163                                }
 164
 165                                /* diff against the proper unmerged stage */
 166                                if (stage == diff_unmerged_stage)
 167                                        ce = nce;
 168                                i++;
 169                        }
 170                        /*
 171                         * Compensate for loop update
 172                         */
 173                        i--;
 174
 175                        if (revs->combine_merges && num_compare_stages == 2) {
 176                                show_combined_diff(dpath, 2,
 177                                                   revs->dense_combined_merges,
 178                                                   revs);
 179                                free(dpath);
 180                                continue;
 181                        }
 182                        FREE_AND_NULL(dpath);
 183
 184                        /*
 185                         * Show the diff for the 'ce' if we found the one
 186                         * from the desired stage.
 187                         */
 188                        pair = diff_unmerge(&revs->diffopt, ce->name);
 189                        if (wt_mode)
 190                                pair->two->mode = wt_mode;
 191                        if (ce_stage(ce) != diff_unmerged_stage)
 192                                continue;
 193                }
 194
 195                if (ce_uptodate(ce) || ce_skip_worktree(ce))
 196                        continue;
 197
 198                /* If CE_VALID is set, don't look at workdir for file removal */
 199                if (ce->ce_flags & CE_VALID) {
 200                        changed = 0;
 201                        newmode = ce->ce_mode;
 202                } else {
 203                        struct stat st;
 204
 205                        changed = check_removed(ce, &st);
 206                        if (changed) {
 207                                if (changed < 0) {
 208                                        perror(ce->name);
 209                                        continue;
 210                                }
 211                                diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 212                                               &ce->oid,
 213                                               !is_null_oid(&ce->oid),
 214                                               ce->name, 0);
 215                                continue;
 216                        } else if (revs->diffopt.ita_invisible_in_index &&
 217                                   ce_intent_to_add(ce)) {
 218                                diff_addremove(&revs->diffopt, '+', ce->ce_mode,
 219                                               &empty_tree_oid, 0,
 220                                               ce->name, 0);
 221                                continue;
 222                        }
 223
 224                        changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 225                                                            ce_option, &dirty_submodule);
 226                        newmode = ce_mode_from_stat(ce, st.st_mode);
 227                }
 228
 229                if (!changed && !dirty_submodule) {
 230                        ce_mark_uptodate(ce);
 231                        if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 232                                continue;
 233                }
 234                oldmode = ce->ce_mode;
 235                old_oid = &ce->oid;
 236                new_oid = changed ? &null_oid : &ce->oid;
 237                diff_change(&revs->diffopt, oldmode, newmode,
 238                            old_oid, new_oid,
 239                            !is_null_oid(old_oid),
 240                            !is_null_oid(new_oid),
 241                            ce->name, 0, dirty_submodule);
 242
 243        }
 244        diffcore_std(&revs->diffopt);
 245        diff_flush(&revs->diffopt);
 246        return 0;
 247}
 248
 249/*
 250 * diff-index
 251 */
 252
 253/* A file entry went away or appeared */
 254static void diff_index_show_file(struct rev_info *revs,
 255                                 const char *prefix,
 256                                 const struct cache_entry *ce,
 257                                 const struct object_id *oid, int oid_valid,
 258                                 unsigned int mode,
 259                                 unsigned dirty_submodule)
 260{
 261        diff_addremove(&revs->diffopt, prefix[0], mode,
 262                       oid, oid_valid, ce->name, dirty_submodule);
 263}
 264
 265static int get_stat_data(const struct cache_entry *ce,
 266                         const struct object_id **oidp,
 267                         unsigned int *modep,
 268                         int cached, int match_missing,
 269                         unsigned *dirty_submodule, struct diff_options *diffopt)
 270{
 271        const struct object_id *oid = &ce->oid;
 272        unsigned int mode = ce->ce_mode;
 273
 274        if (!cached && !ce_uptodate(ce)) {
 275                int changed;
 276                struct stat st;
 277                changed = check_removed(ce, &st);
 278                if (changed < 0)
 279                        return -1;
 280                else if (changed) {
 281                        if (match_missing) {
 282                                *oidp = oid;
 283                                *modep = mode;
 284                                return 0;
 285                        }
 286                        return -1;
 287                }
 288                changed = match_stat_with_submodule(diffopt, ce, &st,
 289                                                    0, dirty_submodule);
 290                if (changed) {
 291                        mode = ce_mode_from_stat(ce, st.st_mode);
 292                        oid = &null_oid;
 293                }
 294        }
 295
 296        *oidp = oid;
 297        *modep = mode;
 298        return 0;
 299}
 300
 301static void show_new_file(struct rev_info *revs,
 302                          const struct cache_entry *new,
 303                          int cached, int match_missing)
 304{
 305        const struct object_id *oid;
 306        unsigned int mode;
 307        unsigned dirty_submodule = 0;
 308
 309        /*
 310         * New file in the index: it might actually be different in
 311         * the working tree.
 312         */
 313        if (get_stat_data(new, &oid, &mode, cached, match_missing,
 314            &dirty_submodule, &revs->diffopt) < 0)
 315                return;
 316
 317        diff_index_show_file(revs, "+", new, oid, !is_null_oid(oid), mode, dirty_submodule);
 318}
 319
 320static int show_modified(struct rev_info *revs,
 321                         const struct cache_entry *old,
 322                         const struct cache_entry *new,
 323                         int report_missing,
 324                         int cached, int match_missing)
 325{
 326        unsigned int mode, oldmode;
 327        const struct object_id *oid;
 328        unsigned dirty_submodule = 0;
 329
 330        if (get_stat_data(new, &oid, &mode, cached, match_missing,
 331                          &dirty_submodule, &revs->diffopt) < 0) {
 332                if (report_missing)
 333                        diff_index_show_file(revs, "-", old,
 334                                             &old->oid, 1, old->ce_mode,
 335                                             0);
 336                return -1;
 337        }
 338
 339        if (revs->combine_merges && !cached &&
 340            (oidcmp(oid, &old->oid) || oidcmp(&old->oid, &new->oid))) {
 341                struct combine_diff_path *p;
 342                int pathlen = ce_namelen(new);
 343
 344                p = xmalloc(combine_diff_path_size(2, pathlen));
 345                p->path = (char *) &p->parent[2];
 346                p->next = NULL;
 347                memcpy(p->path, new->name, pathlen);
 348                p->path[pathlen] = 0;
 349                p->mode = mode;
 350                oidclr(&p->oid);
 351                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 352                p->parent[0].status = DIFF_STATUS_MODIFIED;
 353                p->parent[0].mode = new->ce_mode;
 354                oidcpy(&p->parent[0].oid, &new->oid);
 355                p->parent[1].status = DIFF_STATUS_MODIFIED;
 356                p->parent[1].mode = old->ce_mode;
 357                oidcpy(&p->parent[1].oid, &old->oid);
 358                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 359                free(p);
 360                return 0;
 361        }
 362
 363        oldmode = old->ce_mode;
 364        if (mode == oldmode && !oidcmp(oid, &old->oid) && !dirty_submodule &&
 365            !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 366                return 0;
 367
 368        diff_change(&revs->diffopt, oldmode, mode,
 369                    &old->oid, oid, 1, !is_null_oid(oid),
 370                    old->name, 0, dirty_submodule);
 371        return 0;
 372}
 373
 374/*
 375 * This gets a mix of an existing index and a tree, one pathname entry
 376 * at a time. The index entry may be a single stage-0 one, but it could
 377 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 378 * give you the position and number of entries in the index).
 379 */
 380static void do_oneway_diff(struct unpack_trees_options *o,
 381                           const struct cache_entry *idx,
 382                           const struct cache_entry *tree)
 383{
 384        struct rev_info *revs = o->unpack_data;
 385        int match_missing, cached;
 386
 387        /* i-t-a entries do not actually exist in the index */
 388        if (revs->diffopt.ita_invisible_in_index &&
 389            idx && ce_intent_to_add(idx)) {
 390                idx = NULL;
 391                if (!tree)
 392                        return; /* nothing to diff.. */
 393        }
 394
 395        /* if the entry is not checked out, don't examine work tree */
 396        cached = o->index_only ||
 397                (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 398        /*
 399         * Backward compatibility wart - "diff-index -m" does
 400         * not mean "do not ignore merges", but "match_missing".
 401         *
 402         * But with the revision flag parsing, that's found in
 403         * "!revs->ignore_merges".
 404         */
 405        match_missing = !revs->ignore_merges;
 406
 407        if (cached && idx && ce_stage(idx)) {
 408                struct diff_filepair *pair;
 409                pair = diff_unmerge(&revs->diffopt, idx->name);
 410                if (tree)
 411                        fill_filespec(pair->one, &tree->oid, 1,
 412                                      tree->ce_mode);
 413                return;
 414        }
 415
 416        /*
 417         * Something added to the tree?
 418         */
 419        if (!tree) {
 420                show_new_file(revs, idx, cached, match_missing);
 421                return;
 422        }
 423
 424        /*
 425         * Something removed from the tree?
 426         */
 427        if (!idx) {
 428                diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 429                                     tree->ce_mode, 0);
 430                return;
 431        }
 432
 433        /* Show difference between old and new */
 434        show_modified(revs, tree, idx, 1, cached, match_missing);
 435}
 436
 437/*
 438 * The unpack_trees() interface is designed for merging, so
 439 * the different source entries are designed primarily for
 440 * the source trees, with the old index being really mainly
 441 * used for being replaced by the result.
 442 *
 443 * For diffing, the index is more important, and we only have a
 444 * single tree.
 445 *
 446 * We're supposed to advance o->pos to skip what we have already processed.
 447 *
 448 * This wrapper makes it all more readable, and takes care of all
 449 * the fairly complex unpack_trees() semantic requirements, including
 450 * the skipping, the path matching, the type conflict cases etc.
 451 */
 452static int oneway_diff(const struct cache_entry * const *src,
 453                       struct unpack_trees_options *o)
 454{
 455        const struct cache_entry *idx = src[0];
 456        const struct cache_entry *tree = src[1];
 457        struct rev_info *revs = o->unpack_data;
 458
 459        /*
 460         * Unpack-trees generates a DF/conflict entry if
 461         * there was a directory in the index and a tree
 462         * in the tree. From a diff standpoint, that's a
 463         * delete of the tree and a create of the file.
 464         */
 465        if (tree == o->df_conflict_entry)
 466                tree = NULL;
 467
 468        if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
 469                do_oneway_diff(o, idx, tree);
 470                if (diff_can_quit_early(&revs->diffopt)) {
 471                        o->exiting_early = 1;
 472                        return -1;
 473                }
 474        }
 475
 476        return 0;
 477}
 478
 479static int diff_cache(struct rev_info *revs,
 480                      const struct object_id *tree_oid,
 481                      const char *tree_name,
 482                      int cached)
 483{
 484        struct tree *tree;
 485        struct tree_desc t;
 486        struct unpack_trees_options opts;
 487
 488        tree = parse_tree_indirect(tree_oid);
 489        if (!tree)
 490                return error("bad tree object %s",
 491                             tree_name ? tree_name : oid_to_hex(tree_oid));
 492        memset(&opts, 0, sizeof(opts));
 493        opts.head_idx = 1;
 494        opts.index_only = cached;
 495        opts.diff_index_cached = (cached &&
 496                                  !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 497        opts.merge = 1;
 498        opts.fn = oneway_diff;
 499        opts.unpack_data = revs;
 500        opts.src_index = &the_index;
 501        opts.dst_index = NULL;
 502        opts.pathspec = &revs->diffopt.pathspec;
 503        opts.pathspec->recursive = 1;
 504
 505        init_tree_desc(&t, tree->buffer, tree->size);
 506        return unpack_trees(1, &t, &opts);
 507}
 508
 509int run_diff_index(struct rev_info *revs, int cached)
 510{
 511        struct object_array_entry *ent;
 512
 513        ent = revs->pending.objects;
 514        if (diff_cache(revs, &ent->item->oid, ent->name, cached))
 515                exit(128);
 516
 517        diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 518        diffcore_fix_diff_index(&revs->diffopt);
 519        diffcore_std(&revs->diffopt);
 520        diff_flush(&revs->diffopt);
 521        return 0;
 522}
 523
 524int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 525{
 526        struct rev_info revs;
 527
 528        init_revisions(&revs, NULL);
 529        copy_pathspec(&revs.prune_data, &opt->pathspec);
 530        revs.diffopt = *opt;
 531
 532        if (diff_cache(&revs, tree_oid, NULL, 1))
 533                exit(128);
 534        return 0;
 535}
 536
 537int index_differs_from(const char *def, int diff_flags,
 538                       int ita_invisible_in_index)
 539{
 540        struct rev_info rev;
 541        struct setup_revision_opt opt;
 542
 543        init_revisions(&rev, NULL);
 544        memset(&opt, 0, sizeof(opt));
 545        opt.def = def;
 546        setup_revisions(0, NULL, &rev, &opt);
 547        DIFF_OPT_SET(&rev.diffopt, QUICK);
 548        DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 549        rev.diffopt.flags |= diff_flags;
 550        rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 551        run_diff_index(&rev, 1);
 552        object_array_clear(&rev.pending);
 553        return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 554}