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
  17 struct blobinfo {
  18         unsigned char sha1[20];
  19         const char *name;
  20         unsigned mode;
  21 };
  22
  23 static const char builtin_diff_usage[] =
  24 "git diff <options> <rev>{0,2} -- <path>*";
  25
  26 static void stuff_change(struct diff_options *opt,
  27                          unsigned old_mode, unsigned new_mode,
  28                          const unsigned char *old_sha1,
  29                          const unsigned char *new_sha1,
  30                          const char *old_name,
  31                          const char *new_name)
  32 {
  33         struct diff_filespec *one, *two;
  34
  35         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  36             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  37                 return;
  38
  39         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  40                 unsigned tmp;
  41                 const unsigned char *tmp_u;
  42                 const char *tmp_c;
  43                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  44                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  45                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  46         }
  47
  48         if (opt->prefix &&
  49             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  50              strncmp(new_name, opt->prefix, opt->prefix_length)))
  51                 return;
  52
  53         one = alloc_filespec(old_name);
  54         two = alloc_filespec(new_name);
  55         fill_filespec(one, old_sha1, old_mode);
  56         fill_filespec(two, new_sha1, new_mode);
  57
  58         diff_queue(&diff_queued_diff, one, two);
  59 }
  60
  61 static int builtin_diff_b_f(struct rev_info *revs,
  62                             int argc, const char **argv,
  63                             struct blobinfo *blob,
  64                             const char *path)
  65 {
  66         /* Blob vs file in the working tree*/
  67         struct stat st;
  68
  69         if (argc > 1)
  70                 usage(builtin_diff_usage);
  71
  72         if (lstat(path, &st))
  73                 die("'%s': %s", path, strerror(errno));
  74         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  75                 die("'%s': not a regular file or symlink", path);
  76
  77         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  78
  79         if (blob[0].mode == S_IFINVALID)
  80                 blob[0].mode = canon_mode(st.st_mode);
  81
  82         stuff_change(&revs->diffopt,
  83                      blob[0].mode, canon_mode(st.st_mode),
  84                      blob[0].sha1, null_sha1,
  85                      path, path);
  86         diffcore_std(&revs->diffopt);
  87         diff_flush(&revs->diffopt);
  88         return 0;
  89 }
  90
  91 static int builtin_diff_blobs(struct rev_info *revs,
  92                               int argc, const char **argv,
  93                               struct blobinfo *blob)
  94 {
  95         unsigned mode = canon_mode(S_IFREG | 0644);
  96
  97         if (argc > 1)
  98                 usage(builtin_diff_usage);
  99
 100         if (blob[0].mode == S_IFINVALID)
 101                 blob[0].mode = mode;
 102
 103         if (blob[1].mode == S_IFINVALID)
 104                 blob[1].mode = mode;
 105
 106         stuff_change(&revs->diffopt,
 107                      blob[0].mode, blob[1].mode,
 108                      blob[0].sha1, blob[1].sha1,
 109                      blob[0].name, blob[1].name);
 110         diffcore_std(&revs->diffopt);
 111         diff_flush(&revs->diffopt);
 112         return 0;
 113 }
 114
 115 static int builtin_diff_index(struct rev_info *revs,
 116                               int argc, const char **argv)
 117 {
 118         int cached = 0;
 119         while (1 < argc) {
 120                 const char *arg = argv[1];
 121                 if (!strcmp(arg, "--cached"))
 122                         cached = 1;
 123                 else
 124                         usage(builtin_diff_usage);
 125                 argv++; argc--;
 126         }
 127         if (!cached)
 128                 setup_work_tree();
 129         /*
 130          * Make sure there is one revision (i.e. pending object),
 131          * and there is no revision filtering parameters.
 132          */
 133         if (revs->pending.nr != 1 ||
 134             revs->max_count != -1 || revs->min_age != -1 ||
 135             revs->max_age != -1)
 136                 usage(builtin_diff_usage);
 137         if (read_cache() < 0) {
 138                 perror("read_cache");
 139                 return -1;
 140         }
 141         return run_diff_index(revs, cached);
 142 }
 143
 144 static int builtin_diff_tree(struct rev_info *revs,
 145                              int argc, const char **argv,
 146                              struct object_array_entry *ent)
 147 {
 148         const unsigned char *(sha1[2]);
 149         int swap = 0;
 150
 151         if (argc > 1)
 152                 usage(builtin_diff_usage);
 153
 154         /* We saw two trees, ent[0] and ent[1].
 155          * if ent[1] is uninteresting, they are swapped
 156          */
 157         if (ent[1].item->flags & UNINTERESTING)
 158                 swap = 1;
 159         sha1[swap] = ent[0].item->sha1;
 160         sha1[1-swap] = ent[1].item->sha1;
 161         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 162         log_tree_diff_flush(revs);
 163         return 0;
 164 }
 165
 166 static int builtin_diff_combined(struct rev_info *revs,
 167                                  int argc, const char **argv,
 168                                  struct object_array_entry *ent,
 169                                  int ents)
 170 {
 171         const unsigned char (*parent)[20];
 172         int i;
 173
 174         if (argc > 1)
 175                 usage(builtin_diff_usage);
 176
 177         if (!revs->dense_combined_merges && !revs->combine_merges)
 178                 revs->dense_combined_merges = revs->combine_merges = 1;
 179         parent = xmalloc(ents * sizeof(*parent));
 180         /* Again, the revs are all reverse */
 181         for (i = 0; i < ents; i++)
 182                 hashcpy((unsigned char *)(parent + i),
 183                         ent[ents - 1 - i].item->sha1);
 184         diff_tree_combined(parent[0], parent + 1, ents - 1,
 185                            revs->dense_combined_merges, revs);
 186         return 0;
 187 }
 188
 189 static void refresh_index_quietly(void)
 190 {
 191         struct lock_file *lock_file;
 192         int fd;
 193
 194         lock_file = xcalloc(1, sizeof(struct lock_file));
 195         fd = hold_locked_index(lock_file, 0);
 196         if (fd < 0)
 197                 return;
 198         discard_cache();
 199         read_cache();
 200         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 201
 202         if (active_cache_changed &&
 203             !write_cache(fd, active_cache, active_nr))
 204                 commit_locked_index(lock_file);
 205
 206         rollback_lock_file(lock_file);
 207 }
 208
 209 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 210 {
 211         int result;
 212         unsigned int options = 0;
 213
 214         while (1 < argc && argv[1][0] == '-') {
 215                 if (!strcmp(argv[1], "--base"))
 216                         revs->max_count = 1;
 217                 else if (!strcmp(argv[1], "--ours"))
 218                         revs->max_count = 2;
 219                 else if (!strcmp(argv[1], "--theirs"))
 220                         revs->max_count = 3;
 221                 else if (!strcmp(argv[1], "-q"))
 222                         options |= DIFF_SILENT_ON_REMOVED;
 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() < 0) {
 240                 perror("read_cache");
 241                 return -1;
 242         }
 243         result = run_diff_files(revs, options);
 244         return diff_result_code(&revs->diffopt, result);
 245 }
 246
 247 int cmd_diff(int argc, const char **argv, const char *prefix)
 248 {
 249         int i;
 250         struct rev_info rev;
 251         struct object_array_entry ent[100];
 252         int ents = 0, blobs = 0, paths = 0;
 253         const char *path = NULL;
 254         struct blobinfo blob[2];
 255         int nongit;
 256         int result = 0;
 257
 258         /*
 259          * We could get N tree-ish in the rev.pending_objects list.
 260          * Also there could be M blobs there, and P pathspecs.
 261          *
 262          * N=0, M=0:
 263          *      cache vs files (diff-files)
 264          * N=0, M=2:
 265          *      compare two random blobs.  P must be zero.
 266          * N=0, M=1, P=1:
 267          *      compare a blob with a working tree file.
 268          *
 269          * N=1, M=0:
 270          *      tree vs cache (diff-index --cached)
 271          *
 272          * N=2, M=0:
 273          *      tree vs tree (diff-tree)
 274          *
 275          * N=0, M=0, P=2:
 276          *      compare two filesystem entities (aka --no-index).
 277          *
 278          * Other cases are errors.
 279          */
 280
 281         prefix = setup_git_directory_gently(&nongit);
 282         git_config(git_diff_ui_config, NULL);
 283
 284         if (diff_use_color_default == -1)
 285                 diff_use_color_default = git_use_color_default;
 286
 287         init_revisions(&rev, prefix);
 288
 289         /* If this is a no-index diff, just run it and exit there. */
 290         diff_no_index(&rev, argc, argv, nongit, prefix);
 291
 292         /* Otherwise, we are doing the usual "git" diff */
 293         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 294
 295         if (nongit)
 296                 die("Not a git repository");
 297         argc = setup_revisions(argc, argv, &rev, NULL);
 298         if (!rev.diffopt.output_format) {
 299                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 300                 if (diff_setup_done(&rev.diffopt) < 0)
 301                         die("diff_setup_done failed");
 302         }
 303         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 304         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 305
 306         /*
 307          * If the user asked for our exit code then don't start a
 308          * pager or we would end up reporting its exit code instead.
 309          */
 310         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
 311             check_pager_config("diff") != 0)
 312                 setup_pager();
 313
 314         /*
 315          * Do we have --cached and not have a pending object, then
 316          * default to HEAD by hand.  Eek.
 317          */
 318         if (!rev.pending.nr) {
 319                 int i;
 320                 for (i = 1; i < argc; i++) {
 321                         const char *arg = argv[i];
 322                         if (!strcmp(arg, "--"))
 323                                 break;
 324                         else if (!strcmp(arg, "--cached")) {
 325                                 add_head_to_pending(&rev);
 326                                 if (!rev.pending.nr)
 327                                         die("No HEAD commit to compare with (yet)");
 328                                 break;
 329                         }
 330                 }
 331         }
 332
 333         for (i = 0; i < rev.pending.nr; i++) {
 334                 struct object_array_entry *list = rev.pending.objects+i;
 335                 struct object *obj = list->item;
 336                 const char *name = list->name;
 337                 int flags = (obj->flags & UNINTERESTING);
 338                 if (!obj->parsed)
 339                         obj = parse_object(obj->sha1);
 340                 obj = deref_tag(obj, NULL, 0);
 341                 if (!obj)
 342                         die("invalid object '%s' given.", name);
 343                 if (obj->type == OBJ_COMMIT)
 344                         obj = &((struct commit *)obj)->tree->object;
 345                 if (obj->type == OBJ_TREE) {
 346                         if (ARRAY_SIZE(ent) <= ents)
 347                                 die("more than %d trees given: '%s'",
 348                                     (int) ARRAY_SIZE(ent), name);
 349                         obj->flags |= flags;
 350                         ent[ents].item = obj;
 351                         ent[ents].name = name;
 352                         ents++;
 353                         continue;
 354                 }
 355                 if (obj->type == OBJ_BLOB) {
 356                         if (2 <= blobs)
 357                                 die("more than two blobs given: '%s'", name);
 358                         hashcpy(blob[blobs].sha1, obj->sha1);
 359                         blob[blobs].name = name;
 360                         blob[blobs].mode = list->mode;
 361                         blobs++;
 362                         continue;
 363
 364                 }
 365                 die("unhandled object '%s' given.", name);
 366         }
 367         if (rev.prune_data) {
 368                 const char **pathspec = rev.prune_data;
 369                 while (*pathspec) {
 370                         if (!path)
 371                                 path = *pathspec;
 372                         paths++;
 373                         pathspec++;
 374                 }
 375         }
 376
 377         /*
 378          * Now, do the arguments look reasonable?
 379          */
 380         if (!ents) {
 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 (ents == 1)
 402                 result = builtin_diff_index(&rev, argc, argv);
 403         else if (ents == 2)
 404                 result = builtin_diff_tree(&rev, argc, argv, ent);
 405         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 406                 /* diff A...B where there is one sane merge base between
 407                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 408                  * and ent[2] == B.  Show diff between the base and B.
 409                  */
 410                 ent[1] = ent[2];
 411                 result = builtin_diff_tree(&rev, argc, argv, ent);
 412         }
 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 }