builtin / diff.con commit Merge branch 'jk/maint-null-in-trees' (3b75314)
   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        if (!cached)
 134                setup_work_tree();
 135        /*
 136         * Make sure there is one revision (i.e. pending object),
 137         * and there is no revision filtering parameters.
 138         */
 139        if (revs->pending.nr != 1 ||
 140            revs->max_count != -1 || revs->min_age != -1 ||
 141            revs->max_age != -1)
 142                usage(builtin_diff_usage);
 143        if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
 144                perror("read_cache_preload");
 145                return -1;
 146        }
 147        return run_diff_index(revs, cached);
 148}
 149
 150static int builtin_diff_tree(struct rev_info *revs,
 151                             int argc, const char **argv,
 152                             struct object_array_entry *ent)
 153{
 154        const unsigned char *(sha1[2]);
 155        int swap = 0;
 156
 157        if (argc > 1)
 158                usage(builtin_diff_usage);
 159
 160        /* We saw two trees, ent[0] and ent[1].
 161         * if ent[1] is uninteresting, they are swapped
 162         */
 163        if (ent[1].item->flags & UNINTERESTING)
 164                swap = 1;
 165        sha1[swap] = ent[0].item->sha1;
 166        sha1[1-swap] = ent[1].item->sha1;
 167        diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 168        log_tree_diff_flush(revs);
 169        return 0;
 170}
 171
 172static int builtin_diff_combined(struct rev_info *revs,
 173                                 int argc, const char **argv,
 174                                 struct object_array_entry *ent,
 175                                 int ents)
 176{
 177        struct sha1_array parents = SHA1_ARRAY_INIT;
 178        int i;
 179
 180        if (argc > 1)
 181                usage(builtin_diff_usage);
 182
 183        if (!revs->dense_combined_merges && !revs->combine_merges)
 184                revs->dense_combined_merges = revs->combine_merges = 1;
 185        for (i = 1; i < ents; i++)
 186                sha1_array_append(&parents, ent[i].item->sha1);
 187        diff_tree_combined(ent[0].item->sha1, &parents,
 188                           revs->dense_combined_merges, revs);
 189        sha1_array_clear(&parents);
 190        return 0;
 191}
 192
 193static void refresh_index_quietly(void)
 194{
 195        struct lock_file *lock_file;
 196        int fd;
 197
 198        lock_file = xcalloc(1, sizeof(struct lock_file));
 199        fd = hold_locked_index(lock_file, 0);
 200        if (fd < 0)
 201                return;
 202        discard_cache();
 203        read_cache();
 204        refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 205        update_index_if_able(&the_index, lock_file);
 206}
 207
 208static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 209{
 210        unsigned int options = 0;
 211
 212        while (1 < argc && argv[1][0] == '-') {
 213                if (!strcmp(argv[1], "--base"))
 214                        revs->max_count = 1;
 215                else if (!strcmp(argv[1], "--ours"))
 216                        revs->max_count = 2;
 217                else if (!strcmp(argv[1], "--theirs"))
 218                        revs->max_count = 3;
 219                else if (!strcmp(argv[1], "-q"))
 220                        options |= DIFF_SILENT_ON_REMOVED;
 221                else if (!strcmp(argv[1], "-h"))
 222                        usage(builtin_diff_usage);
 223                else
 224                        return error(_("invalid option: %s"), argv[1]);
 225                argv++; argc--;
 226        }
 227
 228        /*
 229         * "diff --base" should not combine merges because it was not
 230         * asked to.  "diff -c" should not densify (if the user wants
 231         * dense one, --cc can be explicitly asked for, or just rely
 232         * on the default).
 233         */
 234        if (revs->max_count == -1 && !revs->combine_merges &&
 235            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 236                revs->combine_merges = revs->dense_combined_merges = 1;
 237
 238        setup_work_tree();
 239        if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
 240                perror("read_cache_preload");
 241                return -1;
 242        }
 243        return run_diff_files(revs, options);
 244}
 245
 246int cmd_diff(int argc, const char **argv, const char *prefix)
 247{
 248        int i;
 249        struct rev_info rev;
 250        struct object_array_entry ent[100];
 251        int ents = 0, blobs = 0, paths = 0;
 252        const char *path = NULL;
 253        struct blobinfo blob[2];
 254        int nongit;
 255        int result = 0;
 256
 257        /*
 258         * We could get N tree-ish in the rev.pending_objects list.
 259         * Also there could be M blobs there, and P pathspecs.
 260         *
 261         * N=0, M=0:
 262         *      cache vs files (diff-files)
 263         * N=0, M=2:
 264         *      compare two random blobs.  P must be zero.
 265         * N=0, M=1, P=1:
 266         *      compare a blob with a working tree file.
 267         *
 268         * N=1, M=0:
 269         *      tree vs cache (diff-index --cached)
 270         *
 271         * N=2, M=0:
 272         *      tree vs tree (diff-tree)
 273         *
 274         * N=0, M=0, P=2:
 275         *      compare two filesystem entities (aka --no-index).
 276         *
 277         * Other cases are errors.
 278         */
 279
 280        prefix = setup_git_directory_gently(&nongit);
 281        gitmodules_config();
 282        git_config(git_diff_ui_config, NULL);
 283
 284        init_revisions(&rev, prefix);
 285
 286        /* If this is a no-index diff, just run it and exit there. */
 287        diff_no_index(&rev, argc, argv, nongit, prefix);
 288
 289        /* Otherwise, we are doing the usual "git" diff */
 290        rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 291
 292        /* Scale to real terminal size and respect statGraphWidth config */
 293        rev.diffopt.stat_width = -1;
 294        rev.diffopt.stat_graph_width = -1;
 295
 296        /* Default to let external and textconv be used */
 297        DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 298        DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 299
 300        if (nongit)
 301                die(_("Not a git repository"));
 302        argc = setup_revisions(argc, argv, &rev, NULL);
 303        if (!rev.diffopt.output_format) {
 304                rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 305                diff_setup_done(&rev.diffopt);
 306        }
 307
 308        DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 309
 310        setup_diff_pager(&rev.diffopt);
 311
 312        /*
 313         * Do we have --cached and not have a pending object, then
 314         * default to HEAD by hand.  Eek.
 315         */
 316        if (!rev.pending.nr) {
 317                int i;
 318                for (i = 1; i < argc; i++) {
 319                        const char *arg = argv[i];
 320                        if (!strcmp(arg, "--"))
 321                                break;
 322                        else if (!strcmp(arg, "--cached") ||
 323                                 !strcmp(arg, "--staged")) {
 324                                add_head_to_pending(&rev);
 325                                if (!rev.pending.nr) {
 326                                        struct tree *tree;
 327                                        tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 328                                        add_pending_object(&rev, &tree->object, "HEAD");
 329                                }
 330                                break;
 331                        }
 332                }
 333        }
 334
 335        for (i = 0; i < rev.pending.nr; i++) {
 336                struct object_array_entry *list = rev.pending.objects+i;
 337                struct object *obj = list->item;
 338                const char *name = list->name;
 339                int flags = (obj->flags & UNINTERESTING);
 340                if (!obj->parsed)
 341                        obj = parse_object(obj->sha1);
 342                obj = deref_tag(obj, NULL, 0);
 343                if (!obj)
 344                        die(_("invalid object '%s' given."), name);
 345                if (obj->type == OBJ_COMMIT)
 346                        obj = &((struct commit *)obj)->tree->object;
 347                if (obj->type == OBJ_TREE) {
 348                        if (ARRAY_SIZE(ent) <= ents)
 349                                die(_("more than %d trees given: '%s'"),
 350                                    (int) ARRAY_SIZE(ent), name);
 351                        obj->flags |= flags;
 352                        ent[ents].item = obj;
 353                        ent[ents].name = name;
 354                        ents++;
 355                        continue;
 356                }
 357                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 = list->mode;
 363                        blobs++;
 364                        continue;
 365
 366                }
 367                die(_("unhandled object '%s' given."), name);
 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 (!ents) {
 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 (ents == 1)
 400                result = builtin_diff_index(&rev, argc, argv);
 401        else if (ents == 2)
 402                result = builtin_diff_tree(&rev, argc, argv, ent);
 403        else if (ent[0].item->flags & UNINTERESTING) {
 404                /*
 405                 * diff A...B where there is at least one merge base
 406                 * between A and B.  We have ent[0] == merge-base,
 407                 * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
 408                 * between the base and B.  Note that we pick one
 409                 * merge base at random if there are more than one.
 410                 */
 411                ent[1] = ent[ents-1];
 412                result = builtin_diff_tree(&rev, argc, argv, ent);
 413        } else
 414                result = builtin_diff_combined(&rev, argc, argv,
 415                                               ent, ents);
 416        result = diff_result_code(&rev.diffopt, result);
 417        if (1 < rev.diffopt.skip_stat_unmatch)
 418                refresh_index_quietly();
 419        return result;
 420}
 421
 422void setup_diff_pager(struct diff_options *opt)
 423{
 424        /*
 425         * If the user asked for our exit code, then either they want --quiet
 426         * or --exit-code. We should definitely not bother with a pager in the
 427         * former case, as we will generate no output. Since we still properly
 428         * report our exit code even when a pager is run, we _could_ run a
 429         * pager with --exit-code. But since we have not done so historically,
 430         * and because it is easy to find people oneline advising "git diff
 431         * --exit-code" in hooks and other scripts, we do not do so.
 432         */
 433        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
 434            check_pager_config("diff") != 0)
 435                setup_pager();
 436}