diff-lib.con commit Merge branch 'jc/maint-add-p-overlapping-hunks' (f3b173d)
   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
  15/*
  16 * diff-files
  17 */
  18
  19/*
  20 * Has the work tree entity been removed?
  21 *
  22 * Return 1 if it was removed from the work tree, 0 if an entity to be
  23 * compared with the cache entry ce still exists (the latter includes
  24 * the case where a directory that is not a submodule repository
  25 * exists for ce that is a submodule -- it is a submodule that is not
  26 * checked out).  Return negative for an error.
  27 */
  28static int check_removed(const struct cache_entry *ce, struct stat *st)
  29{
  30        if (lstat(ce->name, st) < 0) {
  31                if (errno != ENOENT && errno != ENOTDIR)
  32                        return -1;
  33                return 1;
  34        }
  35        if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  36                return 1;
  37        if (S_ISDIR(st->st_mode)) {
  38                unsigned char sub[20];
  39
  40                /*
  41                 * If ce is already a gitlink, we can have a plain
  42                 * directory (i.e. the submodule is not checked out),
  43                 * or a checked out submodule.  Either case this is not
  44                 * a case where something was removed from the work tree,
  45                 * so we will return 0.
  46                 *
  47                 * Otherwise, if the directory is not a submodule
  48                 * repository, that means ce which was a blob turned into
  49                 * a directory --- the blob was removed!
  50                 */
  51                if (!S_ISGITLINK(ce->ce_mode) &&
  52                    resolve_gitlink_ref(ce->name, "HEAD", sub))
  53                        return 1;
  54        }
  55        return 0;
  56}
  57
  58/*
  59 * Has a file changed or has a submodule new commits or a dirty work tree?
  60 *
  61 * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  62 * option is set, the caller does not only want to know if a submodule is
  63 * modified at all but wants to know all the conditions that are met (new
  64 * commits, untracked content and/or modified content).
  65 */
  66static int match_stat_with_submodule(struct diff_options *diffopt,
  67                                      struct cache_entry *ce, struct stat *st,
  68                                      unsigned ce_option, unsigned *dirty_submodule)
  69{
  70        int changed = ce_match_stat(ce, st, ce_option);
  71        if (S_ISGITLINK(ce->ce_mode)) {
  72                unsigned orig_flags = diffopt->flags;
  73                if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
  74                        set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  75                if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
  76                        changed = 0;
  77                else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
  78                    && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
  79                        *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
  80                diffopt->flags = orig_flags;
  81        }
  82        return changed;
  83}
  84
  85int run_diff_files(struct rev_info *revs, unsigned int option)
  86{
  87        int entries, i;
  88        int diff_unmerged_stage = revs->max_count;
  89        int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
  90        unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  91                              ? CE_MATCH_RACY_IS_DIRTY : 0);
  92
  93        diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  94
  95        if (diff_unmerged_stage < 0)
  96                diff_unmerged_stage = 2;
  97        entries = active_nr;
  98        for (i = 0; i < entries; i++) {
  99                struct stat st;
 100                unsigned int oldmode, newmode;
 101                struct cache_entry *ce = active_cache[i];
 102                int changed;
 103                unsigned dirty_submodule = 0;
 104
 105                if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
 106                    !revs->diffopt.filter &&
 107                    DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
 108                        break;
 109
 110                if (!ce_path_match(ce, &revs->prune_data))
 111                        continue;
 112
 113                if (ce_stage(ce)) {
 114                        struct combine_diff_path *dpath;
 115                        struct diff_filepair *pair;
 116                        unsigned int wt_mode = 0;
 117                        int num_compare_stages = 0;
 118                        size_t path_len;
 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                        dpath->len = path_len;
 127                        memcpy(dpath->path, ce->name, path_len);
 128                        dpath->path[path_len] = '\0';
 129                        hashclr(dpath->sha1);
 130                        memset(&(dpath->parent[0]), 0,
 131                               sizeof(struct combine_diff_parent)*5);
 132
 133                        changed = check_removed(ce, &st);
 134                        if (!changed)
 135                                wt_mode = ce_mode_from_stat(ce, st.st_mode);
 136                        else {
 137                                if (changed < 0) {
 138                                        perror(ce->name);
 139                                        continue;
 140                                }
 141                                if (silent_on_removed)
 142                                        continue;
 143                                wt_mode = 0;
 144                        }
 145                        dpath->mode = wt_mode;
 146
 147                        while (i < entries) {
 148                                struct cache_entry *nce = active_cache[i];
 149                                int stage;
 150
 151                                if (strcmp(ce->name, nce->name))
 152                                        break;
 153
 154                                /* Stage #2 (ours) is the first parent,
 155                                 * stage #3 (theirs) is the second.
 156                                 */
 157                                stage = ce_stage(nce);
 158                                if (2 <= stage) {
 159                                        int mode = nce->ce_mode;
 160                                        num_compare_stages++;
 161                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 162                                        dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 163                                        dpath->parent[stage-2].status =
 164                                                DIFF_STATUS_MODIFIED;
 165                                }
 166
 167                                /* diff against the proper unmerged stage */
 168                                if (stage == diff_unmerged_stage)
 169                                        ce = nce;
 170                                i++;
 171                        }
 172                        /*
 173                         * Compensate for loop update
 174                         */
 175                        i--;
 176
 177                        if (revs->combine_merges && num_compare_stages == 2) {
 178                                show_combined_diff(dpath, 2,
 179                                                   revs->dense_combined_merges,
 180                                                   revs);
 181                                free(dpath);
 182                                continue;
 183                        }
 184                        free(dpath);
 185                        dpath = NULL;
 186
 187                        /*
 188                         * Show the diff for the 'ce' if we found the one
 189                         * from the desired stage.
 190                         */
 191                        pair = diff_unmerge(&revs->diffopt, ce->name);
 192                        if (wt_mode)
 193                                pair->two->mode = wt_mode;
 194                        if (ce_stage(ce) != diff_unmerged_stage)
 195                                continue;
 196                }
 197
 198                if (ce_uptodate(ce) || ce_skip_worktree(ce))
 199                        continue;
 200
 201                /* If CE_VALID is set, don't look at workdir for file removal */
 202                changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 203                if (changed) {
 204                        if (changed < 0) {
 205                                perror(ce->name);
 206                                continue;
 207                        }
 208                        if (silent_on_removed)
 209                                continue;
 210                        diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 211                                       ce->sha1, ce->name, 0);
 212                        continue;
 213                }
 214                changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 215                                                    ce_option, &dirty_submodule);
 216                if (!changed && !dirty_submodule) {
 217                        ce_mark_uptodate(ce);
 218                        if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 219                                continue;
 220                }
 221                oldmode = ce->ce_mode;
 222                newmode = ce_mode_from_stat(ce, st.st_mode);
 223                diff_change(&revs->diffopt, oldmode, newmode,
 224                            ce->sha1, (changed ? null_sha1 : ce->sha1),
 225                            ce->name, 0, dirty_submodule);
 226
 227        }
 228        diffcore_std(&revs->diffopt);
 229        diff_flush(&revs->diffopt);
 230        return 0;
 231}
 232
 233/*
 234 * diff-index
 235 */
 236
 237/* A file entry went away or appeared */
 238static void diff_index_show_file(struct rev_info *revs,
 239                                 const char *prefix,
 240                                 struct cache_entry *ce,
 241                                 const unsigned char *sha1, unsigned int mode,
 242                                 unsigned dirty_submodule)
 243{
 244        diff_addremove(&revs->diffopt, prefix[0], mode,
 245                       sha1, ce->name, dirty_submodule);
 246}
 247
 248static int get_stat_data(struct cache_entry *ce,
 249                         const unsigned char **sha1p,
 250                         unsigned int *modep,
 251                         int cached, int match_missing,
 252                         unsigned *dirty_submodule, struct diff_options *diffopt)
 253{
 254        const unsigned char *sha1 = ce->sha1;
 255        unsigned int mode = ce->ce_mode;
 256
 257        if (!cached && !ce_uptodate(ce)) {
 258                int changed;
 259                struct stat st;
 260                changed = check_removed(ce, &st);
 261                if (changed < 0)
 262                        return -1;
 263                else if (changed) {
 264                        if (match_missing) {
 265                                *sha1p = sha1;
 266                                *modep = mode;
 267                                return 0;
 268                        }
 269                        return -1;
 270                }
 271                changed = match_stat_with_submodule(diffopt, ce, &st,
 272                                                    0, dirty_submodule);
 273                if (changed) {
 274                        mode = ce_mode_from_stat(ce, st.st_mode);
 275                        sha1 = null_sha1;
 276                }
 277        }
 278
 279        *sha1p = sha1;
 280        *modep = mode;
 281        return 0;
 282}
 283
 284static void show_new_file(struct rev_info *revs,
 285                          struct cache_entry *new,
 286                          int cached, int match_missing)
 287{
 288        const unsigned char *sha1;
 289        unsigned int mode;
 290        unsigned dirty_submodule = 0;
 291
 292        /*
 293         * New file in the index: it might actually be different in
 294         * the working copy.
 295         */
 296        if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 297            &dirty_submodule, &revs->diffopt) < 0)
 298                return;
 299
 300        diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
 301}
 302
 303static int show_modified(struct rev_info *revs,
 304                         struct cache_entry *old,
 305                         struct cache_entry *new,
 306                         int report_missing,
 307                         int cached, int match_missing)
 308{
 309        unsigned int mode, oldmode;
 310        const unsigned char *sha1;
 311        unsigned dirty_submodule = 0;
 312
 313        if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 314                          &dirty_submodule, &revs->diffopt) < 0) {
 315                if (report_missing)
 316                        diff_index_show_file(revs, "-", old,
 317                                             old->sha1, old->ce_mode, 0);
 318                return -1;
 319        }
 320
 321        if (revs->combine_merges && !cached &&
 322            (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 323                struct combine_diff_path *p;
 324                int pathlen = ce_namelen(new);
 325
 326                p = xmalloc(combine_diff_path_size(2, pathlen));
 327                p->path = (char *) &p->parent[2];
 328                p->next = NULL;
 329                p->len = pathlen;
 330                memcpy(p->path, new->name, pathlen);
 331                p->path[pathlen] = 0;
 332                p->mode = mode;
 333                hashclr(p->sha1);
 334                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 335                p->parent[0].status = DIFF_STATUS_MODIFIED;
 336                p->parent[0].mode = new->ce_mode;
 337                hashcpy(p->parent[0].sha1, new->sha1);
 338                p->parent[1].status = DIFF_STATUS_MODIFIED;
 339                p->parent[1].mode = old->ce_mode;
 340                hashcpy(p->parent[1].sha1, old->sha1);
 341                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 342                free(p);
 343                return 0;
 344        }
 345
 346        oldmode = old->ce_mode;
 347        if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 348            !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 349                return 0;
 350
 351        diff_change(&revs->diffopt, oldmode, mode,
 352                    old->sha1, sha1, old->name, 0, dirty_submodule);
 353        return 0;
 354}
 355
 356/*
 357 * This gets a mix of an existing index and a tree, one pathname entry
 358 * at a time. The index entry may be a single stage-0 one, but it could
 359 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 360 * give you the position and number of entries in the index).
 361 */
 362static void do_oneway_diff(struct unpack_trees_options *o,
 363        struct cache_entry *idx,
 364        struct cache_entry *tree)
 365{
 366        struct rev_info *revs = o->unpack_data;
 367        int match_missing, cached;
 368
 369        /* if the entry is not checked out, don't examine work tree */
 370        cached = o->index_only ||
 371                (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 372        /*
 373         * Backward compatibility wart - "diff-index -m" does
 374         * not mean "do not ignore merges", but "match_missing".
 375         *
 376         * But with the revision flag parsing, that's found in
 377         * "!revs->ignore_merges".
 378         */
 379        match_missing = !revs->ignore_merges;
 380
 381        if (cached && idx && ce_stage(idx)) {
 382                struct diff_filepair *pair;
 383                pair = diff_unmerge(&revs->diffopt, idx->name);
 384                fill_filespec(pair->one, idx->sha1, idx->ce_mode);
 385                return;
 386        }
 387
 388        /*
 389         * Something added to the tree?
 390         */
 391        if (!tree) {
 392                show_new_file(revs, idx, cached, match_missing);
 393                return;
 394        }
 395
 396        /*
 397         * Something removed from the tree?
 398         */
 399        if (!idx) {
 400                diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
 401                return;
 402        }
 403
 404        /* Show difference between old and new */
 405        show_modified(revs, tree, idx, 1, cached, match_missing);
 406}
 407
 408/*
 409 * The unpack_trees() interface is designed for merging, so
 410 * the different source entries are designed primarily for
 411 * the source trees, with the old index being really mainly
 412 * used for being replaced by the result.
 413 *
 414 * For diffing, the index is more important, and we only have a
 415 * single tree.
 416 *
 417 * We're supposed to advance o->pos to skip what we have already processed.
 418 *
 419 * This wrapper makes it all more readable, and takes care of all
 420 * the fairly complex unpack_trees() semantic requirements, including
 421 * the skipping, the path matching, the type conflict cases etc.
 422 */
 423static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 424{
 425        struct cache_entry *idx = src[0];
 426        struct cache_entry *tree = src[1];
 427        struct rev_info *revs = o->unpack_data;
 428
 429        /*
 430         * Unpack-trees generates a DF/conflict entry if
 431         * there was a directory in the index and a tree
 432         * in the tree. From a diff standpoint, that's a
 433         * delete of the tree and a create of the file.
 434         */
 435        if (tree == o->df_conflict_entry)
 436                tree = NULL;
 437
 438        if (ce_path_match(idx ? idx : tree, &revs->prune_data))
 439                do_oneway_diff(o, idx, tree);
 440
 441        return 0;
 442}
 443
 444int run_diff_index(struct rev_info *revs, int cached)
 445{
 446        struct object *ent;
 447        struct tree *tree;
 448        const char *tree_name;
 449        struct unpack_trees_options opts;
 450        struct tree_desc t;
 451
 452        ent = revs->pending.objects[0].item;
 453        tree_name = revs->pending.objects[0].name;
 454        tree = parse_tree_indirect(ent->sha1);
 455        if (!tree)
 456                return error("bad tree object %s", tree_name);
 457
 458        memset(&opts, 0, sizeof(opts));
 459        opts.head_idx = 1;
 460        opts.index_only = cached;
 461        opts.diff_index_cached = (cached &&
 462                                  !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 463        opts.merge = 1;
 464        opts.fn = oneway_diff;
 465        opts.unpack_data = revs;
 466        opts.src_index = &the_index;
 467        opts.dst_index = NULL;
 468
 469        init_tree_desc(&t, tree->buffer, tree->size);
 470        if (unpack_trees(1, &t, &opts))
 471                exit(128);
 472
 473        diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 474        diffcore_fix_diff_index(&revs->diffopt);
 475        diffcore_std(&revs->diffopt);
 476        diff_flush(&revs->diffopt);
 477        return 0;
 478}
 479
 480int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 481{
 482        struct tree *tree;
 483        struct rev_info revs;
 484        int i;
 485        struct cache_entry **dst;
 486        struct cache_entry *last = NULL;
 487        struct unpack_trees_options opts;
 488        struct tree_desc t;
 489
 490        /*
 491         * This is used by git-blame to run diff-cache internally;
 492         * it potentially needs to repeatedly run this, so we will
 493         * start by removing the higher order entries the last round
 494         * left behind.
 495         */
 496        dst = active_cache;
 497        for (i = 0; i < active_nr; i++) {
 498                struct cache_entry *ce = active_cache[i];
 499                if (ce_stage(ce)) {
 500                        if (last && !strcmp(ce->name, last->name))
 501                                continue;
 502                        cache_tree_invalidate_path(active_cache_tree,
 503                                                   ce->name);
 504                        last = ce;
 505                        ce->ce_flags |= CE_REMOVE;
 506                }
 507                *dst++ = ce;
 508        }
 509        active_nr = dst - active_cache;
 510
 511        init_revisions(&revs, NULL);
 512        init_pathspec(&revs.prune_data, opt->pathspec.raw);
 513        tree = parse_tree_indirect(tree_sha1);
 514        if (!tree)
 515                die("bad tree object %s", sha1_to_hex(tree_sha1));
 516
 517        memset(&opts, 0, sizeof(opts));
 518        opts.head_idx = 1;
 519        opts.index_only = 1;
 520        opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
 521        opts.merge = 1;
 522        opts.fn = oneway_diff;
 523        opts.unpack_data = &revs;
 524        opts.src_index = &the_index;
 525        opts.dst_index = &the_index;
 526
 527        init_tree_desc(&t, tree->buffer, tree->size);
 528        if (unpack_trees(1, &t, &opts))
 529                exit(128);
 530        return 0;
 531}
 532
 533int index_differs_from(const char *def, int diff_flags)
 534{
 535        struct rev_info rev;
 536        struct setup_revision_opt opt;
 537
 538        init_revisions(&rev, NULL);
 539        memset(&opt, 0, sizeof(opt));
 540        opt.def = def;
 541        setup_revisions(0, NULL, &rev, &opt);
 542        DIFF_OPT_SET(&rev.diffopt, QUICK);
 543        DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 544        rev.diffopt.flags |= diff_flags;
 545        run_diff_index(&rev, 1);
 546        if (rev.pending.alloc)
 547                free(rev.pending.objects);
 548        return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 549}