builtin/diff.c

   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
  19 struct blobinfo {
  20         unsigned char sha1[20];
  21         const char *name;
  22         unsigned mode;
  23 };
  24
  25 static const char builtin_diff_usage[] =
  26 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  27
  28 static 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
  65 static 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
  96 static 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
 121 static 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) < 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
 154 static 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
 178 static 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
 199 static 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
 214 static 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) < 0) {
 246                 perror("read_cache_preload");
 247                 return -1;
 248         }
 249         return run_diff_files(revs, options);
 250 }
 251
 252 int 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                 /* builtin_diff_b_f() */
 371                 GUARD_PATHSPEC(&rev.prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
 372                 if (!path)
 373                         path = rev.prune_data.items[0].match;
 374                 paths += rev.prune_data.nr;
 375         }
 376
 377         /*
 378          * Now, do the arguments look reasonable?
 379          */
 380         if (!ent.nr) {
 381                 switch (blobs) {
 382                 case 0:
 383                         result = builtin_diff_files(&rev, argc, argv);
 384                         break;
 385                 case 1:
 386                         if (paths != 1)
 387                                 usage(builtin_diff_usage);
 388                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 389                         break;
 390                 case 2:
 391                         if (paths)
 392                                 usage(builtin_diff_usage);
 393                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 394                         break;
 395                 default:
 396                         usage(builtin_diff_usage);
 397                 }
 398         }
 399         else if (blobs)
 400                 usage(builtin_diff_usage);
 401         else if (ent.nr == 1)
 402                 result = builtin_diff_index(&rev, argc, argv);
 403         else if (ent.nr == 2)
 404                 result = builtin_diff_tree(&rev, argc, argv,
 405                                            &ent.objects[0], &ent.objects[1]);
 406         else if (ent.objects[0].item->flags & UNINTERESTING) {
 407                 /*
 408                  * diff A...B where there is at least one merge base
 409                  * between A and B.  We have ent.objects[0] ==
 410                  * merge-base, ent.objects[ents-2] == A, and
 411                  * ent.objects[ents-1] == B.  Show diff between the
 412                  * base and B.  Note that we pick one merge base at
 413                  * random if there are more than one.
 414                  */
 415                 result = builtin_diff_tree(&rev, argc, argv,
 416                                            &ent.objects[0],
 417                                            &ent.objects[ent.nr-1]);
 418         } else
 419                 result = builtin_diff_combined(&rev, argc, argv,
 420                                                ent.objects, ent.nr);
 421         result = diff_result_code(&rev.diffopt, result);
 422         if (1 < rev.diffopt.skip_stat_unmatch)
 423                 refresh_index_quietly();
 424         return result;
 425 }