diff-lib.con commit Sync with 1.6.4.2 (f324cb5)
   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
  14/*
  15 * diff-files
  16 */
  17
  18/*
  19 * Has the work tree entity been removed?
  20 *
  21 * Return 1 if it was removed from the work tree, 0 if an entity to be
  22 * compared with the cache entry ce still exists (the latter includes
  23 * the case where a directory that is not a submodule repository
  24 * exists for ce that is a submodule -- it is a submodule that is not
  25 * checked out).  Return negative for an error.
  26 */
  27static int check_removed(const struct cache_entry *ce, struct stat *st)
  28{
  29        if (lstat(ce->name, st) < 0) {
  30                if (errno != ENOENT && errno != ENOTDIR)
  31                        return -1;
  32                return 1;
  33        }
  34        if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  35                return 1;
  36        if (S_ISDIR(st->st_mode)) {
  37                unsigned char sub[20];
  38
  39                /*
  40                 * If ce is already a gitlink, we can have a plain
  41                 * directory (i.e. the submodule is not checked out),
  42                 * or a checked out submodule.  Either case this is not
  43                 * a case where something was removed from the work tree,
  44                 * so we will return 0.
  45                 *
  46                 * Otherwise, if the directory is not a submodule
  47                 * repository, that means ce which was a blob turned into
  48                 * a directory --- the blob was removed!
  49                 */
  50                if (!S_ISGITLINK(ce->ce_mode) &&
  51                    resolve_gitlink_ref(ce->name, "HEAD", sub))
  52                        return 1;
  53        }
  54        return 0;
  55}
  56
  57int run_diff_files(struct rev_info *revs, unsigned int option)
  58{
  59        int entries, i;
  60        int diff_unmerged_stage = revs->max_count;
  61        int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
  62        unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  63                              ? CE_MATCH_RACY_IS_DIRTY : 0);
  64
  65        diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  66
  67        if (diff_unmerged_stage < 0)
  68                diff_unmerged_stage = 2;
  69        entries = active_nr;
  70        for (i = 0; i < entries; i++) {
  71                struct stat st;
  72                unsigned int oldmode, newmode;
  73                struct cache_entry *ce = active_cache[i];
  74                int changed;
  75
  76                if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
  77                        DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
  78                        break;
  79
  80                if (!ce_path_match(ce, revs->prune_data))
  81                        continue;
  82
  83                if (ce_stage(ce)) {
  84                        struct combine_diff_path *dpath;
  85                        int num_compare_stages = 0;
  86                        size_t path_len;
  87
  88                        path_len = ce_namelen(ce);
  89
  90                        dpath = xmalloc(combine_diff_path_size(5, path_len));
  91                        dpath->path = (char *) &(dpath->parent[5]);
  92
  93                        dpath->next = NULL;
  94                        dpath->len = path_len;
  95                        memcpy(dpath->path, ce->name, path_len);
  96                        dpath->path[path_len] = '\0';
  97                        hashclr(dpath->sha1);
  98                        memset(&(dpath->parent[0]), 0,
  99                               sizeof(struct combine_diff_parent)*5);
 100
 101                        changed = check_removed(ce, &st);
 102                        if (!changed)
 103                                dpath->mode = ce_mode_from_stat(ce, st.st_mode);
 104                        else {
 105                                if (changed < 0) {
 106                                        perror(ce->name);
 107                                        continue;
 108                                }
 109                                if (silent_on_removed)
 110                                        continue;
 111                        }
 112
 113                        while (i < entries) {
 114                                struct cache_entry *nce = active_cache[i];
 115                                int stage;
 116
 117                                if (strcmp(ce->name, nce->name))
 118                                        break;
 119
 120                                /* Stage #2 (ours) is the first parent,
 121                                 * stage #3 (theirs) is the second.
 122                                 */
 123                                stage = ce_stage(nce);
 124                                if (2 <= stage) {
 125                                        int mode = nce->ce_mode;
 126                                        num_compare_stages++;
 127                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 128                                        dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 129                                        dpath->parent[stage-2].status =
 130                                                DIFF_STATUS_MODIFIED;
 131                                }
 132
 133                                /* diff against the proper unmerged stage */
 134                                if (stage == diff_unmerged_stage)
 135                                        ce = nce;
 136                                i++;
 137                        }
 138                        /*
 139                         * Compensate for loop update
 140                         */
 141                        i--;
 142
 143                        if (revs->combine_merges && num_compare_stages == 2) {
 144                                show_combined_diff(dpath, 2,
 145                                                   revs->dense_combined_merges,
 146                                                   revs);
 147                                free(dpath);
 148                                continue;
 149                        }
 150                        free(dpath);
 151                        dpath = NULL;
 152
 153                        /*
 154                         * Show the diff for the 'ce' if we found the one
 155                         * from the desired stage.
 156                         */
 157                        diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 158                        if (ce_stage(ce) != diff_unmerged_stage)
 159                                continue;
 160                }
 161
 162                if (ce_uptodate(ce))
 163                        continue;
 164
 165                /* If CE_VALID is set, don't look at workdir for file removal */
 166                changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 167                if (changed) {
 168                        if (changed < 0) {
 169                                perror(ce->name);
 170                                continue;
 171                        }
 172                        if (silent_on_removed)
 173                                continue;
 174                        diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 175                                       ce->sha1, ce->name);
 176                        continue;
 177                }
 178                changed = ce_match_stat(ce, &st, ce_option);
 179                if (!changed) {
 180                        ce_mark_uptodate(ce);
 181                        if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 182                                continue;
 183                }
 184                oldmode = ce->ce_mode;
 185                newmode = ce_mode_from_stat(ce, st.st_mode);
 186                diff_change(&revs->diffopt, oldmode, newmode,
 187                            ce->sha1, (changed ? null_sha1 : ce->sha1),
 188                            ce->name);
 189
 190        }
 191        diffcore_std(&revs->diffopt);
 192        diff_flush(&revs->diffopt);
 193        return 0;
 194}
 195
 196/*
 197 * diff-index
 198 */
 199
 200/* A file entry went away or appeared */
 201static void diff_index_show_file(struct rev_info *revs,
 202                                 const char *prefix,
 203                                 struct cache_entry *ce,
 204                                 const unsigned char *sha1, unsigned int mode)
 205{
 206        diff_addremove(&revs->diffopt, prefix[0], mode,
 207                       sha1, ce->name);
 208}
 209
 210static int get_stat_data(struct cache_entry *ce,
 211                         const unsigned char **sha1p,
 212                         unsigned int *modep,
 213                         int cached, int match_missing)
 214{
 215        const unsigned char *sha1 = ce->sha1;
 216        unsigned int mode = ce->ce_mode;
 217
 218        if (!cached && !ce_uptodate(ce)) {
 219                int changed;
 220                struct stat st;
 221                changed = check_removed(ce, &st);
 222                if (changed < 0)
 223                        return -1;
 224                else if (changed) {
 225                        if (match_missing) {
 226                                *sha1p = sha1;
 227                                *modep = mode;
 228                                return 0;
 229                        }
 230                        return -1;
 231                }
 232                changed = ce_match_stat(ce, &st, 0);
 233                if (changed) {
 234                        mode = ce_mode_from_stat(ce, st.st_mode);
 235                        sha1 = null_sha1;
 236                }
 237        }
 238
 239        *sha1p = sha1;
 240        *modep = mode;
 241        return 0;
 242}
 243
 244static void show_new_file(struct rev_info *revs,
 245                          struct cache_entry *new,
 246                          int cached, int match_missing)
 247{
 248        const unsigned char *sha1;
 249        unsigned int mode;
 250
 251        /*
 252         * New file in the index: it might actually be different in
 253         * the working copy.
 254         */
 255        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 256                return;
 257
 258        diff_index_show_file(revs, "+", new, sha1, mode);
 259}
 260
 261static int show_modified(struct rev_info *revs,
 262                         struct cache_entry *old,
 263                         struct cache_entry *new,
 264                         int report_missing,
 265                         int cached, int match_missing)
 266{
 267        unsigned int mode, oldmode;
 268        const unsigned char *sha1;
 269
 270        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 271                if (report_missing)
 272                        diff_index_show_file(revs, "-", old,
 273                                             old->sha1, old->ce_mode);
 274                return -1;
 275        }
 276
 277        if (revs->combine_merges && !cached &&
 278            (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 279                struct combine_diff_path *p;
 280                int pathlen = ce_namelen(new);
 281
 282                p = xmalloc(combine_diff_path_size(2, pathlen));
 283                p->path = (char *) &p->parent[2];
 284                p->next = NULL;
 285                p->len = pathlen;
 286                memcpy(p->path, new->name, pathlen);
 287                p->path[pathlen] = 0;
 288                p->mode = mode;
 289                hashclr(p->sha1);
 290                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 291                p->parent[0].status = DIFF_STATUS_MODIFIED;
 292                p->parent[0].mode = new->ce_mode;
 293                hashcpy(p->parent[0].sha1, new->sha1);
 294                p->parent[1].status = DIFF_STATUS_MODIFIED;
 295                p->parent[1].mode = old->ce_mode;
 296                hashcpy(p->parent[1].sha1, old->sha1);
 297                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 298                free(p);
 299                return 0;
 300        }
 301
 302        oldmode = old->ce_mode;
 303        if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 304            !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 305                return 0;
 306
 307        diff_change(&revs->diffopt, oldmode, mode,
 308                    old->sha1, sha1, old->name);
 309        return 0;
 310}
 311
 312/*
 313 * This gets a mix of an existing index and a tree, one pathname entry
 314 * at a time. The index entry may be a single stage-0 one, but it could
 315 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 316 * give you the position and number of entries in the index).
 317 */
 318static void do_oneway_diff(struct unpack_trees_options *o,
 319        struct cache_entry *idx,
 320        struct cache_entry *tree)
 321{
 322        struct rev_info *revs = o->unpack_data;
 323        int match_missing, cached;
 324
 325        /* if the entry is not checked out, don't examine work tree */
 326        cached = o->index_only || (idx && (idx->ce_flags & CE_VALID));
 327        /*
 328         * Backward compatibility wart - "diff-index -m" does
 329         * not mean "do not ignore merges", but "match_missing".
 330         *
 331         * But with the revision flag parsing, that's found in
 332         * "!revs->ignore_merges".
 333         */
 334        match_missing = !revs->ignore_merges;
 335
 336        if (cached && idx && ce_stage(idx)) {
 337                diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
 338                             idx->sha1);
 339                return;
 340        }
 341
 342        /*
 343         * Something added to the tree?
 344         */
 345        if (!tree) {
 346                show_new_file(revs, idx, cached, match_missing);
 347                return;
 348        }
 349
 350        /*
 351         * Something removed from the tree?
 352         */
 353        if (!idx) {
 354                diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode);
 355                return;
 356        }
 357
 358        /* Show difference between old and new */
 359        show_modified(revs, tree, idx, 1, cached, match_missing);
 360}
 361
 362static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
 363{
 364        int len = ce_namelen(ce);
 365        const struct index_state *index = o->src_index;
 366
 367        while (o->pos < index->cache_nr) {
 368                struct cache_entry *next = index->cache[o->pos];
 369                if (len != ce_namelen(next))
 370                        break;
 371                if (memcmp(ce->name, next->name, len))
 372                        break;
 373                o->pos++;
 374        }
 375}
 376
 377/*
 378 * The unpack_trees() interface is designed for merging, so
 379 * the different source entries are designed primarily for
 380 * the source trees, with the old index being really mainly
 381 * used for being replaced by the result.
 382 *
 383 * For diffing, the index is more important, and we only have a
 384 * single tree.
 385 *
 386 * We're supposed to return how many index entries we want to skip.
 387 *
 388 * This wrapper makes it all more readable, and takes care of all
 389 * the fairly complex unpack_trees() semantic requirements, including
 390 * the skipping, the path matching, the type conflict cases etc.
 391 */
 392static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 393{
 394        struct cache_entry *idx = src[0];
 395        struct cache_entry *tree = src[1];
 396        struct rev_info *revs = o->unpack_data;
 397
 398        if (idx && ce_stage(idx))
 399                skip_same_name(idx, o);
 400
 401        /*
 402         * Unpack-trees generates a DF/conflict entry if
 403         * there was a directory in the index and a tree
 404         * in the tree. From a diff standpoint, that's a
 405         * delete of the tree and a create of the file.
 406         */
 407        if (tree == o->df_conflict_entry)
 408                tree = NULL;
 409
 410        if (ce_path_match(idx ? idx : tree, revs->prune_data))
 411                do_oneway_diff(o, idx, tree);
 412
 413        return 0;
 414}
 415
 416int run_diff_index(struct rev_info *revs, int cached)
 417{
 418        struct object *ent;
 419        struct tree *tree;
 420        const char *tree_name;
 421        struct unpack_trees_options opts;
 422        struct tree_desc t;
 423
 424        ent = revs->pending.objects[0].item;
 425        tree_name = revs->pending.objects[0].name;
 426        tree = parse_tree_indirect(ent->sha1);
 427        if (!tree)
 428                return error("bad tree object %s", tree_name);
 429
 430        memset(&opts, 0, sizeof(opts));
 431        opts.head_idx = 1;
 432        opts.index_only = cached;
 433        opts.diff_index_cached = (cached &&
 434                                  !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 435        opts.merge = 1;
 436        opts.fn = oneway_diff;
 437        opts.unpack_data = revs;
 438        opts.src_index = &the_index;
 439        opts.dst_index = NULL;
 440
 441        init_tree_desc(&t, tree->buffer, tree->size);
 442        if (unpack_trees(1, &t, &opts))
 443                exit(128);
 444
 445        diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 446        diffcore_std(&revs->diffopt);
 447        diff_flush(&revs->diffopt);
 448        return 0;
 449}
 450
 451int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 452{
 453        struct tree *tree;
 454        struct rev_info revs;
 455        int i;
 456        struct cache_entry **dst;
 457        struct cache_entry *last = NULL;
 458        struct unpack_trees_options opts;
 459        struct tree_desc t;
 460
 461        /*
 462         * This is used by git-blame to run diff-cache internally;
 463         * it potentially needs to repeatedly run this, so we will
 464         * start by removing the higher order entries the last round
 465         * left behind.
 466         */
 467        dst = active_cache;
 468        for (i = 0; i < active_nr; i++) {
 469                struct cache_entry *ce = active_cache[i];
 470                if (ce_stage(ce)) {
 471                        if (last && !strcmp(ce->name, last->name))
 472                                continue;
 473                        cache_tree_invalidate_path(active_cache_tree,
 474                                                   ce->name);
 475                        last = ce;
 476                        ce->ce_flags |= CE_REMOVE;
 477                }
 478                *dst++ = ce;
 479        }
 480        active_nr = dst - active_cache;
 481
 482        init_revisions(&revs, NULL);
 483        revs.prune_data = opt->paths;
 484        tree = parse_tree_indirect(tree_sha1);
 485        if (!tree)
 486                die("bad tree object %s", sha1_to_hex(tree_sha1));
 487
 488        memset(&opts, 0, sizeof(opts));
 489        opts.head_idx = 1;
 490        opts.index_only = 1;
 491        opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
 492        opts.merge = 1;
 493        opts.fn = oneway_diff;
 494        opts.unpack_data = &revs;
 495        opts.src_index = &the_index;
 496        opts.dst_index = &the_index;
 497
 498        init_tree_desc(&t, tree->buffer, tree->size);
 499        if (unpack_trees(1, &t, &opts))
 500                exit(128);
 501        return 0;
 502}
 503
 504int index_differs_from(const char *def, int diff_flags)
 505{
 506        struct rev_info rev;
 507
 508        init_revisions(&rev, NULL);
 509        setup_revisions(0, NULL, &rev, def);
 510        DIFF_OPT_SET(&rev.diffopt, QUIET);
 511        DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 512        rev.diffopt.flags |= diff_flags;
 513        run_diff_index(&rev, 1);
 514        if (rev.pending.alloc)
 515                free(rev.pending.objects);
 516        return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 517}