builtin / diff.con commit Merge branch 'vd/doc-unpack-objects' into maint (5022b58)
   1/*
   2 * Builtin "git diff"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "color.h"
   8#include "commit.h"
   9#include "blob.h"
  10#include "tag.h"
  11#include "diff.h"
  12#include "diffcore.h"
  13#include "revision.h"
  14#include "log-tree.h"
  15#include "builtin.h"
  16#include "submodule.h"
  17#include "sha1-array.h"
  18
  19struct blobinfo {
  20        unsigned char sha1[20];
  21        const char *name;
  22        unsigned mode;
  23};
  24
  25static const char builtin_diff_usage[] =
  26"git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  27
  28static void stuff_change(struct diff_options *opt,
  29                         unsigned old_mode, unsigned new_mode,
  30                         const unsigned char *old_sha1,
  31                         const unsigned char *new_sha1,
  32                         int old_sha1_valid,
  33                         int new_sha1_valid,
  34                         const char *old_name,
  35                         const char *new_name)
  36{
  37        struct diff_filespec *one, *two;
  38
  39        if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  40            !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  41                return;
  42
  43        if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  44                unsigned tmp;
  45                const unsigned char *tmp_u;
  46                const char *tmp_c;
  47                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  48                tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  49                tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  50        }
  51
  52        if (opt->prefix &&
  53            (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  54             strncmp(new_name, opt->prefix, opt->prefix_length)))
  55                return;
  56
  57        one = alloc_filespec(old_name);
  58        two = alloc_filespec(new_name);
  59        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
  60        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
  61
  62        diff_queue(&diff_queued_diff, one, two);
  63}
  64
  65static int builtin_diff_b_f(struct rev_info *revs,
  66                            int argc, const char **argv,
  67                            struct blobinfo *blob,
  68                            const char *path)
  69{
  70        /* Blob vs file in the working tree*/
  71        struct stat st;
  72
  73        if (argc > 1)
  74                usage(builtin_diff_usage);
  75
  76        if (lstat(path, &st))
  77                die_errno(_("failed to stat '%s'"), path);
  78        if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  79                die(_("'%s': not a regular file or symlink"), path);
  80
  81        diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  82
  83        if (blob[0].mode == S_IFINVALID)
  84                blob[0].mode = canon_mode(st.st_mode);
  85
  86        stuff_change(&revs->diffopt,
  87                     blob[0].mode, canon_mode(st.st_mode),
  88                     blob[0].sha1, null_sha1,
  89                     1, 0,
  90                     path, path);
  91        diffcore_std(&revs->diffopt);
  92        diff_flush(&revs->diffopt);
  93        return 0;
  94}
  95
  96static int builtin_diff_blobs(struct rev_info *revs,
  97                              int argc, const char **argv,
  98                              struct blobinfo *blob)
  99{
 100        unsigned mode = canon_mode(S_IFREG | 0644);
 101
 102        if (argc > 1)
 103                usage(builtin_diff_usage);
 104
 105        if (blob[0].mode == S_IFINVALID)
 106                blob[0].mode = mode;
 107
 108        if (blob[1].mode == S_IFINVALID)
 109                blob[1].mode = mode;
 110
 111        stuff_change(&revs->diffopt,
 112                     blob[0].mode, blob[1].mode,
 113                     blob[0].sha1, blob[1].sha1,
 114                     1, 1,
 115                     blob[0].name, blob[1].name);
 116        diffcore_std(&revs->diffopt);
 117        diff_flush(&revs->diffopt);
 118        return 0;
 119}
 120
 121static int builtin_diff_index(struct rev_info *revs,
 122                              int argc, const char **argv)
 123{
 124        int cached = 0;
 125        while (1 < argc) {
 126                const char *arg = argv[1];
 127                if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 128                        cached = 1;
 129                else
 130                        usage(builtin_diff_usage);
 131                argv++; argc--;
 132        }
 133        /*
 134         * Make sure there is one revision (i.e. pending object),
 135         * and there is no revision filtering parameters.
 136         */
 137        if (revs->pending.nr != 1 ||
 138            revs->max_count != -1 || revs->min_age != -1 ||
 139            revs->max_age != -1)
 140                usage(builtin_diff_usage);
 141        if (!cached) {
 142                setup_work_tree();
 143                if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
 144                        perror("read_cache_preload");
 145                        return -1;
 146                }
 147        } else if (read_cache() < 0) {
 148                perror("read_cache");
 149                return -1;
 150        }
 151        return run_diff_index(revs, cached);
 152}
 153
 154static int builtin_diff_tree(struct rev_info *revs,
 155                             int argc, const char **argv,
 156                             struct object_array_entry *ent0,
 157                             struct object_array_entry *ent1)
 158{
 159        const unsigned char *(sha1[2]);
 160        int swap = 0;
 161
 162        if (argc > 1)
 163                usage(builtin_diff_usage);
 164
 165        /*
 166         * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 167         * swap them.
 168         */
 169        if (ent1->item->flags & UNINTERESTING)
 170                swap = 1;
 171        sha1[swap] = ent0->item->sha1;
 172        sha1[1-swap] = ent1->item->sha1;
 173        diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 174        log_tree_diff_flush(revs);
 175        return 0;
 176}
 177
 178static int builtin_diff_combined(struct rev_info *revs,
 179                                 int argc, const char **argv,
 180                                 struct object_array_entry *ent,
 181                                 int ents)
 182{
 183        struct sha1_array parents = SHA1_ARRAY_INIT;
 184        int i;
 185
 186        if (argc > 1)
 187                usage(builtin_diff_usage);
 188
 189        if (!revs->dense_combined_merges && !revs->combine_merges)
 190                revs->dense_combined_merges = revs->combine_merges = 1;
 191        for (i = 1; i < ents; i++)
 192                sha1_array_append(&parents, ent[i].item->sha1);
 193        diff_tree_combined(ent[0].item->sha1, &parents,
 194                           revs->dense_combined_merges, revs);
 195        sha1_array_clear(&parents);
 196        return 0;
 197}
 198
 199static void refresh_index_quietly(void)
 200{
 201        struct lock_file *lock_file;
 202        int fd;
 203
 204        lock_file = xcalloc(1, sizeof(struct lock_file));
 205        fd = hold_locked_index(lock_file, 0);
 206        if (fd < 0)
 207                return;
 208        discard_cache();
 209        read_cache();
 210        refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 211        update_index_if_able(&the_index, lock_file);
 212}
 213
 214static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 215{
 216        unsigned int options = 0;
 217
 218        while (1 < argc && argv[1][0] == '-') {
 219                if (!strcmp(argv[1], "--base"))
 220                        revs->max_count = 1;
 221                else if (!strcmp(argv[1], "--ours"))
 222                        revs->max_count = 2;
 223                else if (!strcmp(argv[1], "--theirs"))
 224                        revs->max_count = 3;
 225                else if (!strcmp(argv[1], "-q"))
 226                        options |= DIFF_SILENT_ON_REMOVED;
 227                else if (!strcmp(argv[1], "-h"))
 228                        usage(builtin_diff_usage);
 229                else
 230                        return error(_("invalid option: %s"), argv[1]);
 231                argv++; argc--;
 232        }
 233
 234        /*
 235         * "diff --base" should not combine merges because it was not
 236         * asked to.  "diff -c" should not densify (if the user wants
 237         * dense one, --cc can be explicitly asked for, or just rely
 238         * on the default).
 239         */
 240        if (revs->max_count == -1 && !revs->combine_merges &&
 241            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 242                revs->combine_merges = revs->dense_combined_merges = 1;
 243
 244        setup_work_tree();
 245        if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
 246                perror("read_cache_preload");
 247                return -1;
 248        }
 249        return run_diff_files(revs, options);
 250}
 251
 252int cmd_diff(int argc, const char **argv, const char *prefix)
 253{
 254        int i;
 255        struct rev_info rev;
 256        struct object_array ent = OBJECT_ARRAY_INIT;
 257        int blobs = 0, paths = 0;
 258        const char *path = NULL;
 259        struct blobinfo blob[2];
 260        int nongit;
 261        int result = 0;
 262
 263        /*
 264         * We could get N tree-ish in the rev.pending_objects list.
 265         * Also there could be M blobs there, and P pathspecs.
 266         *
 267         * N=0, M=0:
 268         *      cache vs files (diff-files)
 269         * N=0, M=2:
 270         *      compare two random blobs.  P must be zero.
 271         * N=0, M=1, P=1:
 272         *      compare a blob with a working tree file.
 273         *
 274         * N=1, M=0:
 275         *      tree vs cache (diff-index --cached)
 276         *
 277         * N=2, M=0:
 278         *      tree vs tree (diff-tree)
 279         *
 280         * N=0, M=0, P=2:
 281         *      compare two filesystem entities (aka --no-index).
 282         *
 283         * Other cases are errors.
 284         */
 285
 286        prefix = setup_git_directory_gently(&nongit);
 287        gitmodules_config();
 288        git_config(git_diff_ui_config, NULL);
 289
 290        init_revisions(&rev, prefix);
 291
 292        /* If this is a no-index diff, just run it and exit there. */
 293        diff_no_index(&rev, argc, argv, nongit, prefix);
 294
 295        /* Otherwise, we are doing the usual "git" diff */
 296        rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 297
 298        /* Scale to real terminal size and respect statGraphWidth config */
 299        rev.diffopt.stat_width = -1;
 300        rev.diffopt.stat_graph_width = -1;
 301
 302        /* Default to let external and textconv be used */
 303        DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 304        DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 305
 306        if (nongit)
 307                die(_("Not a git repository"));
 308        argc = setup_revisions(argc, argv, &rev, NULL);
 309        if (!rev.diffopt.output_format) {
 310                rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 311                diff_setup_done(&rev.diffopt);
 312        }
 313
 314        DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 315
 316        setup_diff_pager(&rev.diffopt);
 317
 318        /*
 319         * Do we have --cached and not have a pending object, then
 320         * default to HEAD by hand.  Eek.
 321         */
 322        if (!rev.pending.nr) {
 323                int i;
 324                for (i = 1; i < argc; i++) {
 325                        const char *arg = argv[i];
 326                        if (!strcmp(arg, "--"))
 327                                break;
 328                        else if (!strcmp(arg, "--cached") ||
 329                                 !strcmp(arg, "--staged")) {
 330                                add_head_to_pending(&rev);
 331                                if (!rev.pending.nr) {
 332                                        struct tree *tree;
 333                                        tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 334                                        add_pending_object(&rev, &tree->object, "HEAD");
 335                                }
 336                                break;
 337                        }
 338                }
 339        }
 340
 341        for (i = 0; i < rev.pending.nr; i++) {
 342                struct object_array_entry *entry = &rev.pending.objects[i];
 343                struct object *obj = entry->item;
 344                const char *name = entry->name;
 345                int flags = (obj->flags & UNINTERESTING);
 346                if (!obj->parsed)
 347                        obj = parse_object(obj->sha1);
 348                obj = deref_tag(obj, NULL, 0);
 349                if (!obj)
 350                        die(_("invalid object '%s' given."), name);
 351                if (obj->type == OBJ_COMMIT)
 352                        obj = &((struct commit *)obj)->tree->object;
 353
 354                if (obj->type == OBJ_TREE) {
 355                        obj->flags |= flags;
 356                        add_object_array(obj, name, &ent);
 357                } else if (obj->type == OBJ_BLOB) {
 358                        if (2 <= blobs)
 359                                die(_("more than two blobs given: '%s'"), name);
 360                        hashcpy(blob[blobs].sha1, obj->sha1);
 361                        blob[blobs].name = name;
 362                        blob[blobs].mode = entry->mode;
 363                        blobs++;
 364
 365                } else {
 366                        die(_("unhandled object '%s' given."), name);
 367                }
 368        }
 369        if (rev.prune_data.nr) {
 370                if (!path)
 371                        path = rev.prune_data.items[0].match;
 372                paths += rev.prune_data.nr;
 373        }
 374
 375        /*
 376         * Now, do the arguments look reasonable?
 377         */
 378        if (!ent.nr) {
 379                switch (blobs) {
 380                case 0:
 381                        result = builtin_diff_files(&rev, argc, argv);
 382                        break;
 383                case 1:
 384                        if (paths != 1)
 385                                usage(builtin_diff_usage);
 386                        result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 387                        break;
 388                case 2:
 389                        if (paths)
 390                                usage(builtin_diff_usage);
 391                        result = builtin_diff_blobs(&rev, argc, argv, blob);
 392                        break;
 393                default:
 394                        usage(builtin_diff_usage);
 395                }
 396        }
 397        else if (blobs)
 398                usage(builtin_diff_usage);
 399        else if (ent.nr == 1)
 400                result = builtin_diff_index(&rev, argc, argv);
 401        else if (ent.nr == 2)
 402                result = builtin_diff_tree(&rev, argc, argv,
 403                                           &ent.objects[0], &ent.objects[1]);
 404        else if (ent.objects[0].item->flags & UNINTERESTING) {
 405                /*
 406                 * diff A...B where there is at least one merge base
 407                 * between A and B.  We have ent.objects[0] ==
 408                 * merge-base, ent.objects[ents-2] == A, and
 409                 * ent.objects[ents-1] == B.  Show diff between the
 410                 * base and B.  Note that we pick one merge base at
 411                 * random if there are more than one.
 412                 */
 413                result = builtin_diff_tree(&rev, argc, argv,
 414                                           &ent.objects[0],
 415                                           &ent.objects[ent.nr-1]);
 416        } else
 417                result = builtin_diff_combined(&rev, argc, argv,
 418                                               ent.objects, ent.nr);
 419        result = diff_result_code(&rev.diffopt, result);
 420        if (1 < rev.diffopt.skip_stat_unmatch)
 421                refresh_index_quietly();
 422        return result;
 423}