builtin / diff.con commit Merge branch 'jk/rev-list-count-with-bitmap' (6d8c545)
   1/*
   2 * Builtin "git diff"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "lockfile.h"
   8#include "color.h"
   9#include "commit.h"
  10#include "blob.h"
  11#include "tag.h"
  12#include "diff.h"
  13#include "diffcore.h"
  14#include "revision.h"
  15#include "log-tree.h"
  16#include "builtin.h"
  17#include "submodule.h"
  18#include "sha1-array.h"
  19
  20#define DIFF_NO_INDEX_EXPLICIT 1
  21#define DIFF_NO_INDEX_IMPLICIT 2
  22
  23struct blobinfo {
  24        unsigned char sha1[20];
  25        const char *name;
  26        unsigned mode;
  27};
  28
  29static const char builtin_diff_usage[] =
  30"git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  31
  32static void stuff_change(struct diff_options *opt,
  33                         unsigned old_mode, unsigned new_mode,
  34                         const unsigned char *old_sha1,
  35                         const unsigned char *new_sha1,
  36                         int old_sha1_valid,
  37                         int new_sha1_valid,
  38                         const char *old_name,
  39                         const char *new_name)
  40{
  41        struct diff_filespec *one, *two;
  42
  43        if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  44            !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  45                return;
  46
  47        if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  48                unsigned tmp;
  49                const unsigned char *tmp_u;
  50                const char *tmp_c;
  51                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  52                tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  53                tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  54        }
  55
  56        if (opt->prefix &&
  57            (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  58             strncmp(new_name, opt->prefix, opt->prefix_length)))
  59                return;
  60
  61        one = alloc_filespec(old_name);
  62        two = alloc_filespec(new_name);
  63        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
  64        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
  65
  66        diff_queue(&diff_queued_diff, one, two);
  67}
  68
  69static int builtin_diff_b_f(struct rev_info *revs,
  70                            int argc, const char **argv,
  71                            struct blobinfo *blob)
  72{
  73        /* Blob vs file in the working tree*/
  74        struct stat st;
  75        const char *path;
  76
  77        if (argc > 1)
  78                usage(builtin_diff_usage);
  79
  80        GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
  81        path = revs->prune_data.items[0].match;
  82
  83        if (lstat(path, &st))
  84                die_errno(_("failed to stat '%s'"), path);
  85        if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  86                die(_("'%s': not a regular file or symlink"), path);
  87
  88        diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  89
  90        if (blob[0].mode == S_IFINVALID)
  91                blob[0].mode = canon_mode(st.st_mode);
  92
  93        stuff_change(&revs->diffopt,
  94                     blob[0].mode, canon_mode(st.st_mode),
  95                     blob[0].sha1, null_sha1,
  96                     1, 0,
  97                     path, path);
  98        diffcore_std(&revs->diffopt);
  99        diff_flush(&revs->diffopt);
 100        return 0;
 101}
 102
 103static int builtin_diff_blobs(struct rev_info *revs,
 104                              int argc, const char **argv,
 105                              struct blobinfo *blob)
 106{
 107        unsigned mode = canon_mode(S_IFREG | 0644);
 108
 109        if (argc > 1)
 110                usage(builtin_diff_usage);
 111
 112        if (blob[0].mode == S_IFINVALID)
 113                blob[0].mode = mode;
 114
 115        if (blob[1].mode == S_IFINVALID)
 116                blob[1].mode = mode;
 117
 118        stuff_change(&revs->diffopt,
 119                     blob[0].mode, blob[1].mode,
 120                     blob[0].sha1, blob[1].sha1,
 121                     1, 1,
 122                     blob[0].name, blob[1].name);
 123        diffcore_std(&revs->diffopt);
 124        diff_flush(&revs->diffopt);
 125        return 0;
 126}
 127
 128static int builtin_diff_index(struct rev_info *revs,
 129                              int argc, const char **argv)
 130{
 131        int cached = 0;
 132        while (1 < argc) {
 133                const char *arg = argv[1];
 134                if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 135                        cached = 1;
 136                else
 137                        usage(builtin_diff_usage);
 138                argv++; argc--;
 139        }
 140        /*
 141         * Make sure there is one revision (i.e. pending object),
 142         * and there is no revision filtering parameters.
 143         */
 144        if (revs->pending.nr != 1 ||
 145            revs->max_count != -1 || revs->min_age != -1 ||
 146            revs->max_age != -1)
 147                usage(builtin_diff_usage);
 148        if (!cached) {
 149                setup_work_tree();
 150                if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 151                        perror("read_cache_preload");
 152                        return -1;
 153                }
 154        } else if (read_cache() < 0) {
 155                perror("read_cache");
 156                return -1;
 157        }
 158        return run_diff_index(revs, cached);
 159}
 160
 161static int builtin_diff_tree(struct rev_info *revs,
 162                             int argc, const char **argv,
 163                             struct object_array_entry *ent0,
 164                             struct object_array_entry *ent1)
 165{
 166        const unsigned char *(sha1[2]);
 167        int swap = 0;
 168
 169        if (argc > 1)
 170                usage(builtin_diff_usage);
 171
 172        /*
 173         * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 174         * swap them.
 175         */
 176        if (ent1->item->flags & UNINTERESTING)
 177                swap = 1;
 178        sha1[swap] = ent0->item->oid.hash;
 179        sha1[1 - swap] = ent1->item->oid.hash;
 180        diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 181        log_tree_diff_flush(revs);
 182        return 0;
 183}
 184
 185static int builtin_diff_combined(struct rev_info *revs,
 186                                 int argc, const char **argv,
 187                                 struct object_array_entry *ent,
 188                                 int ents)
 189{
 190        struct sha1_array parents = SHA1_ARRAY_INIT;
 191        int i;
 192
 193        if (argc > 1)
 194                usage(builtin_diff_usage);
 195
 196        if (!revs->dense_combined_merges && !revs->combine_merges)
 197                revs->dense_combined_merges = revs->combine_merges = 1;
 198        for (i = 1; i < ents; i++)
 199                sha1_array_append(&parents, ent[i].item->oid.hash);
 200        diff_tree_combined(ent[0].item->oid.hash, &parents,
 201                           revs->dense_combined_merges, revs);
 202        sha1_array_clear(&parents);
 203        return 0;
 204}
 205
 206static void refresh_index_quietly(void)
 207{
 208        struct lock_file *lock_file;
 209        int fd;
 210
 211        lock_file = xcalloc(1, sizeof(struct lock_file));
 212        fd = hold_locked_index(lock_file, 0);
 213        if (fd < 0)
 214                return;
 215        discard_cache();
 216        read_cache();
 217        refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 218        update_index_if_able(&the_index, lock_file);
 219}
 220
 221static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 222{
 223        unsigned int options = 0;
 224
 225        while (1 < argc && argv[1][0] == '-') {
 226                if (!strcmp(argv[1], "--base"))
 227                        revs->max_count = 1;
 228                else if (!strcmp(argv[1], "--ours"))
 229                        revs->max_count = 2;
 230                else if (!strcmp(argv[1], "--theirs"))
 231                        revs->max_count = 3;
 232                else if (!strcmp(argv[1], "-q"))
 233                        options |= DIFF_SILENT_ON_REMOVED;
 234                else if (!strcmp(argv[1], "-h"))
 235                        usage(builtin_diff_usage);
 236                else
 237                        return error(_("invalid option: %s"), argv[1]);
 238                argv++; argc--;
 239        }
 240
 241        /*
 242         * "diff --base" should not combine merges because it was not
 243         * asked to.  "diff -c" should not densify (if the user wants
 244         * dense one, --cc can be explicitly asked for, or just rely
 245         * on the default).
 246         */
 247        if (revs->max_count == -1 && !revs->combine_merges &&
 248            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 249                revs->combine_merges = revs->dense_combined_merges = 1;
 250
 251        setup_work_tree();
 252        if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 253                perror("read_cache_preload");
 254                return -1;
 255        }
 256        return run_diff_files(revs, options);
 257}
 258
 259int cmd_diff(int argc, const char **argv, const char *prefix)
 260{
 261        int i;
 262        struct rev_info rev;
 263        struct object_array ent = OBJECT_ARRAY_INIT;
 264        int blobs = 0, paths = 0;
 265        struct blobinfo blob[2];
 266        int nongit = 0, no_index = 0;
 267        int result = 0;
 268
 269        /*
 270         * We could get N tree-ish in the rev.pending_objects list.
 271         * Also there could be M blobs there, and P pathspecs.
 272         *
 273         * N=0, M=0:
 274         *      cache vs files (diff-files)
 275         * N=0, M=2:
 276         *      compare two random blobs.  P must be zero.
 277         * N=0, M=1, P=1:
 278         *      compare a blob with a working tree file.
 279         *
 280         * N=1, M=0:
 281         *      tree vs cache (diff-index --cached)
 282         *
 283         * N=2, M=0:
 284         *      tree vs tree (diff-tree)
 285         *
 286         * N=0, M=0, P=2:
 287         *      compare two filesystem entities (aka --no-index).
 288         *
 289         * Other cases are errors.
 290         */
 291
 292        /* Were we asked to do --no-index explicitly? */
 293        for (i = 1; i < argc; i++) {
 294                if (!strcmp(argv[i], "--")) {
 295                        i++;
 296                        break;
 297                }
 298                if (!strcmp(argv[i], "--no-index"))
 299                        no_index = DIFF_NO_INDEX_EXPLICIT;
 300                if (argv[i][0] != '-')
 301                        break;
 302        }
 303
 304        if (!no_index)
 305                prefix = setup_git_directory_gently(&nongit);
 306
 307        /*
 308         * Treat git diff with at least one path outside of the
 309         * repo the same as if the command would have been executed
 310         * outside of a git repository.  In this case it behaves
 311         * the same way as "git diff --no-index <a> <b>", which acts
 312         * as a colourful "diff" replacement.
 313         */
 314        if (nongit || ((argc == i + 2) &&
 315                       (!path_inside_repo(prefix, argv[i]) ||
 316                        !path_inside_repo(prefix, argv[i + 1]))))
 317                no_index = DIFF_NO_INDEX_IMPLICIT;
 318
 319        if (!no_index)
 320                gitmodules_config();
 321        init_diff_ui_defaults();
 322        git_config(git_diff_ui_config, NULL);
 323        precompose_argv(argc, argv);
 324
 325        init_revisions(&rev, prefix);
 326
 327        if (no_index && argc != i + 2) {
 328                if (no_index == DIFF_NO_INDEX_IMPLICIT) {
 329                        /*
 330                         * There was no --no-index and there were not two
 331                         * paths. It is possible that the user intended
 332                         * to do an inside-repository operation.
 333                         */
 334                        fprintf(stderr, "Not a git repository\n");
 335                        fprintf(stderr,
 336                                "To compare two paths outside a working tree:\n");
 337                }
 338                /* Give the usage message for non-repository usage and exit. */
 339                usagef("git diff %s <path> <path>",
 340                       no_index == DIFF_NO_INDEX_EXPLICIT ?
 341                       "--no-index" : "[--no-index]");
 342
 343        }
 344        if (no_index)
 345                /* If this is a no-index diff, just run it and exit there. */
 346                diff_no_index(&rev, argc, argv);
 347
 348        /* Otherwise, we are doing the usual "git" diff */
 349        rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 350
 351        /* Scale to real terminal size and respect statGraphWidth config */
 352        rev.diffopt.stat_width = -1;
 353        rev.diffopt.stat_graph_width = -1;
 354
 355        /* Default to let external and textconv be used */
 356        DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 357        DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 358
 359        if (nongit)
 360                die(_("Not a git repository"));
 361        argc = setup_revisions(argc, argv, &rev, NULL);
 362        if (!rev.diffopt.output_format) {
 363                rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 364                diff_setup_done(&rev.diffopt);
 365        }
 366
 367        DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 368
 369        setup_diff_pager(&rev.diffopt);
 370
 371        /*
 372         * Do we have --cached and not have a pending object, then
 373         * default to HEAD by hand.  Eek.
 374         */
 375        if (!rev.pending.nr) {
 376                int i;
 377                for (i = 1; i < argc; i++) {
 378                        const char *arg = argv[i];
 379                        if (!strcmp(arg, "--"))
 380                                break;
 381                        else if (!strcmp(arg, "--cached") ||
 382                                 !strcmp(arg, "--staged")) {
 383                                add_head_to_pending(&rev);
 384                                if (!rev.pending.nr) {
 385                                        struct tree *tree;
 386                                        tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 387                                        add_pending_object(&rev, &tree->object, "HEAD");
 388                                }
 389                                break;
 390                        }
 391                }
 392        }
 393
 394        for (i = 0; i < rev.pending.nr; i++) {
 395                struct object_array_entry *entry = &rev.pending.objects[i];
 396                struct object *obj = entry->item;
 397                const char *name = entry->name;
 398                int flags = (obj->flags & UNINTERESTING);
 399                if (!obj->parsed)
 400                        obj = parse_object(obj->oid.hash);
 401                obj = deref_tag(obj, NULL, 0);
 402                if (!obj)
 403                        die(_("invalid object '%s' given."), name);
 404                if (obj->type == OBJ_COMMIT)
 405                        obj = &((struct commit *)obj)->tree->object;
 406
 407                if (obj->type == OBJ_TREE) {
 408                        obj->flags |= flags;
 409                        add_object_array(obj, name, &ent);
 410                } else if (obj->type == OBJ_BLOB) {
 411                        if (2 <= blobs)
 412                                die(_("more than two blobs given: '%s'"), name);
 413                        hashcpy(blob[blobs].sha1, obj->oid.hash);
 414                        blob[blobs].name = name;
 415                        blob[blobs].mode = entry->mode;
 416                        blobs++;
 417
 418                } else {
 419                        die(_("unhandled object '%s' given."), name);
 420                }
 421        }
 422        if (rev.prune_data.nr)
 423                paths += rev.prune_data.nr;
 424
 425        /*
 426         * Now, do the arguments look reasonable?
 427         */
 428        if (!ent.nr) {
 429                switch (blobs) {
 430                case 0:
 431                        result = builtin_diff_files(&rev, argc, argv);
 432                        break;
 433                case 1:
 434                        if (paths != 1)
 435                                usage(builtin_diff_usage);
 436                        result = builtin_diff_b_f(&rev, argc, argv, blob);
 437                        break;
 438                case 2:
 439                        if (paths)
 440                                usage(builtin_diff_usage);
 441                        result = builtin_diff_blobs(&rev, argc, argv, blob);
 442                        break;
 443                default:
 444                        usage(builtin_diff_usage);
 445                }
 446        }
 447        else if (blobs)
 448                usage(builtin_diff_usage);
 449        else if (ent.nr == 1)
 450                result = builtin_diff_index(&rev, argc, argv);
 451        else if (ent.nr == 2)
 452                result = builtin_diff_tree(&rev, argc, argv,
 453                                           &ent.objects[0], &ent.objects[1]);
 454        else if (ent.objects[0].item->flags & UNINTERESTING) {
 455                /*
 456                 * diff A...B where there is at least one merge base
 457                 * between A and B.  We have ent.objects[0] ==
 458                 * merge-base, ent.objects[ents-2] == A, and
 459                 * ent.objects[ents-1] == B.  Show diff between the
 460                 * base and B.  Note that we pick one merge base at
 461                 * random if there are more than one.
 462                 */
 463                result = builtin_diff_tree(&rev, argc, argv,
 464                                           &ent.objects[0],
 465                                           &ent.objects[ent.nr-1]);
 466        } else
 467                result = builtin_diff_combined(&rev, argc, argv,
 468                                               ent.objects, ent.nr);
 469        result = diff_result_code(&rev.diffopt, result);
 470        if (1 < rev.diffopt.skip_stat_unmatch)
 471                refresh_index_quietly();
 472        return result;
 473}