builtin-diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "commit.h"
   8 #include "blob.h"
   9 #include "tag.h"
  10 #include "diff.h"
  11 #include "diffcore.h"
  12 #include "revision.h"
  13 #include "log-tree.h"
  14 #include "builtin.h"
  15
  16 struct blobinfo {
  17         unsigned char sha1[20];
  18         const char *name;
  19         unsigned mode;
  20 };
  21
  22 static const char builtin_diff_usage[] =
  23 "git-diff <options> <rev>{0,2} -- <path>*";
  24
  25 static void stuff_change(struct diff_options *opt,
  26                          unsigned old_mode, unsigned new_mode,
  27                          const unsigned char *old_sha1,
  28                          const unsigned char *new_sha1,
  29                          const char *old_name,
  30                          const char *new_name)
  31 {
  32         struct diff_filespec *one, *two;
  33
  34         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  35             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  36                 return;
  37
  38         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  39                 unsigned tmp;
  40                 const unsigned char *tmp_u;
  41                 const char *tmp_c;
  42                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  43                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  44                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  45         }
  46         one = alloc_filespec(old_name);
  47         two = alloc_filespec(new_name);
  48         fill_filespec(one, old_sha1, old_mode);
  49         fill_filespec(two, new_sha1, new_mode);
  50
  51         /* NEEDSWORK: shouldn't this part of diffopt??? */
  52         diff_queue(&diff_queued_diff, one, two);
  53 }
  54
  55 static int builtin_diff_b_f(struct rev_info *revs,
  56                             int argc, const char **argv,
  57                             struct blobinfo *blob,
  58                             const char *path)
  59 {
  60         /* Blob vs file in the working tree*/
  61         struct stat st;
  62
  63         if (argc > 1)
  64                 usage(builtin_diff_usage);
  65
  66         if (lstat(path, &st))
  67                 die("'%s': %s", path, strerror(errno));
  68         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  69                 die("'%s': not a regular file or symlink", path);
  70
  71         if (blob[0].mode == S_IFINVALID)
  72                 blob[0].mode = canon_mode(st.st_mode);
  73
  74         stuff_change(&revs->diffopt,
  75                      blob[0].mode, canon_mode(st.st_mode),
  76                      blob[0].sha1, null_sha1,
  77                      path, path);
  78         diffcore_std(&revs->diffopt);
  79         diff_flush(&revs->diffopt);
  80         return 0;
  81 }
  82
  83 static int builtin_diff_blobs(struct rev_info *revs,
  84                               int argc, const char **argv,
  85                               struct blobinfo *blob)
  86 {
  87         unsigned mode = canon_mode(S_IFREG | 0644);
  88
  89         if (argc > 1)
  90                 usage(builtin_diff_usage);
  91
  92         if (blob[0].mode == S_IFINVALID)
  93                 blob[0].mode = mode;
  94
  95         if (blob[1].mode == S_IFINVALID)
  96                 blob[1].mode = mode;
  97
  98         stuff_change(&revs->diffopt,
  99                      blob[0].mode, blob[1].mode,
 100                      blob[0].sha1, blob[1].sha1,
 101                      blob[0].name, blob[1].name);
 102         diffcore_std(&revs->diffopt);
 103         diff_flush(&revs->diffopt);
 104         return 0;
 105 }
 106
 107 static int builtin_diff_index(struct rev_info *revs,
 108                               int argc, const char **argv)
 109 {
 110         int cached = 0;
 111         while (1 < argc) {
 112                 const char *arg = argv[1];
 113                 if (!strcmp(arg, "--cached"))
 114                         cached = 1;
 115                 else
 116                         usage(builtin_diff_usage);
 117                 argv++; argc--;
 118         }
 119         /*
 120          * Make sure there is one revision (i.e. pending object),
 121          * and there is no revision filtering parameters.
 122          */
 123         if (revs->pending.nr != 1 ||
 124             revs->max_count != -1 || revs->min_age != -1 ||
 125             revs->max_age != -1)
 126                 usage(builtin_diff_usage);
 127         if (read_cache() < 0) {
 128                 perror("read_cache");
 129                 return -1;
 130         }
 131         return run_diff_index(revs, cached);
 132 }
 133
 134 static int builtin_diff_tree(struct rev_info *revs,
 135                              int argc, const char **argv,
 136                              struct object_array_entry *ent)
 137 {
 138         const unsigned char *(sha1[2]);
 139         int swap = 0;
 140
 141         if (argc > 1)
 142                 usage(builtin_diff_usage);
 143
 144         /* We saw two trees, ent[0] and ent[1].
 145          * if ent[1] is uninteresting, they are swapped
 146          */
 147         if (ent[1].item->flags & UNINTERESTING)
 148                 swap = 1;
 149         sha1[swap] = ent[0].item->sha1;
 150         sha1[1-swap] = ent[1].item->sha1;
 151         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 152         log_tree_diff_flush(revs);
 153         return 0;
 154 }
 155
 156 static int builtin_diff_combined(struct rev_info *revs,
 157                                  int argc, const char **argv,
 158                                  struct object_array_entry *ent,
 159                                  int ents)
 160 {
 161         const unsigned char (*parent)[20];
 162         int i;
 163
 164         if (argc > 1)
 165                 usage(builtin_diff_usage);
 166
 167         if (!revs->dense_combined_merges && !revs->combine_merges)
 168                 revs->dense_combined_merges = revs->combine_merges = 1;
 169         parent = xmalloc(ents * sizeof(*parent));
 170         /* Again, the revs are all reverse */
 171         for (i = 0; i < ents; i++)
 172                 hashcpy((unsigned char *)(parent + i),
 173                         ent[ents - 1 - i].item->sha1);
 174         diff_tree_combined(parent[0], parent + 1, ents - 1,
 175                            revs->dense_combined_merges, revs);
 176         return 0;
 177 }
 178
 179 static void refresh_index_quietly(void)
 180 {
 181         struct lock_file *lock_file;
 182         int fd;
 183
 184         lock_file = xcalloc(1, sizeof(struct lock_file));
 185         fd = hold_locked_index(lock_file, 0);
 186         if (fd < 0)
 187                 return;
 188         discard_cache();
 189         read_cache();
 190         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 191
 192         if (active_cache_changed &&
 193             !write_cache(fd, active_cache, active_nr) && !close(fd))
 194                 commit_locked_index(lock_file);
 195
 196         rollback_lock_file(lock_file);
 197 }
 198
 199 int cmd_diff(int argc, const char **argv, const char *prefix)
 200 {
 201         int i;
 202         struct rev_info rev;
 203         struct object_array_entry ent[100];
 204         int ents = 0, blobs = 0, paths = 0;
 205         const char *path = NULL;
 206         struct blobinfo blob[2];
 207         int nongit = 0;
 208         int result = 0;
 209
 210         /*
 211          * We could get N tree-ish in the rev.pending_objects list.
 212          * Also there could be M blobs there, and P pathspecs.
 213          *
 214          * N=0, M=0:
 215          *      cache vs files (diff-files)
 216          * N=0, M=2:
 217          *      compare two random blobs.  P must be zero.
 218          * N=0, M=1, P=1:
 219          *      compare a blob with a working tree file.
 220          *
 221          * N=1, M=0:
 222          *      tree vs cache (diff-index --cached)
 223          *
 224          * N=2, M=0:
 225          *      tree vs tree (diff-tree)
 226          *
 227          * Other cases are errors.
 228          */
 229
 230         prefix = setup_git_directory_gently(&nongit);
 231         git_config(git_diff_ui_config);
 232         init_revisions(&rev, prefix);
 233         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 234
 235         if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
 236                 argc = 0;
 237         else
 238                 argc = setup_revisions(argc, argv, &rev, NULL);
 239         if (!rev.diffopt.output_format) {
 240                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 241                 if (diff_setup_done(&rev.diffopt) < 0)
 242                         die("diff_setup_done failed");
 243         }
 244         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 245         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 246
 247         /* If the user asked for our exit code then don't start a
 248          * pager or we would end up reporting its exit code instead.
 249          */
 250         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
 251                 setup_pager();
 252
 253         /* Do we have --cached and not have a pending object, then
 254          * default to HEAD by hand.  Eek.
 255          */
 256         if (!rev.pending.nr) {
 257                 int i;
 258                 for (i = 1; i < argc; i++) {
 259                         const char *arg = argv[i];
 260                         if (!strcmp(arg, "--"))
 261                                 break;
 262                         else if (!strcmp(arg, "--cached")) {
 263                                 add_head_to_pending(&rev);
 264                                 if (!rev.pending.nr)
 265                                         die("No HEAD commit to compare with (yet)");
 266                                 break;
 267                         }
 268                 }
 269         }
 270
 271         for (i = 0; i < rev.pending.nr; i++) {
 272                 struct object_array_entry *list = rev.pending.objects+i;
 273                 struct object *obj = list->item;
 274                 const char *name = list->name;
 275                 int flags = (obj->flags & UNINTERESTING);
 276                 if (!obj->parsed)
 277                         obj = parse_object(obj->sha1);
 278                 obj = deref_tag(obj, NULL, 0);
 279                 if (!obj)
 280                         die("invalid object '%s' given.", name);
 281                 if (obj->type == OBJ_COMMIT)
 282                         obj = &((struct commit *)obj)->tree->object;
 283                 if (obj->type == OBJ_TREE) {
 284                         if (ARRAY_SIZE(ent) <= ents)
 285                                 die("more than %d trees given: '%s'",
 286                                     (int) ARRAY_SIZE(ent), name);
 287                         obj->flags |= flags;
 288                         ent[ents].item = obj;
 289                         ent[ents].name = name;
 290                         ents++;
 291                         continue;
 292                 }
 293                 if (obj->type == OBJ_BLOB) {
 294                         if (2 <= blobs)
 295                                 die("more than two blobs given: '%s'", name);
 296                         hashcpy(blob[blobs].sha1, obj->sha1);
 297                         blob[blobs].name = name;
 298                         blob[blobs].mode = list->mode;
 299                         blobs++;
 300                         continue;
 301
 302                 }
 303                 die("unhandled object '%s' given.", name);
 304         }
 305         if (rev.prune_data) {
 306                 const char **pathspec = rev.prune_data;
 307                 while (*pathspec) {
 308                         if (!path)
 309                                 path = *pathspec;
 310                         paths++;
 311                         pathspec++;
 312                 }
 313         }
 314
 315         /*
 316          * Now, do the arguments look reasonable?
 317          */
 318         if (!ents) {
 319                 switch (blobs) {
 320                 case 0:
 321                         result = run_diff_files_cmd(&rev, argc, argv);
 322                         break;
 323                 case 1:
 324                         if (paths != 1)
 325                                 usage(builtin_diff_usage);
 326                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 327                         break;
 328                 case 2:
 329                         if (paths)
 330                                 usage(builtin_diff_usage);
 331                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 332                         break;
 333                 default:
 334                         usage(builtin_diff_usage);
 335                 }
 336         }
 337         else if (blobs)
 338                 usage(builtin_diff_usage);
 339         else if (ents == 1)
 340                 result = builtin_diff_index(&rev, argc, argv);
 341         else if (ents == 2)
 342                 result = builtin_diff_tree(&rev, argc, argv, ent);
 343         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 344                 /* diff A...B where there is one sane merge base between
 345                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 346                  * and ent[2] == B.  Show diff between the base and B.
 347                  */
 348                 ent[1] = ent[2];
 349                 result = builtin_diff_tree(&rev, argc, argv, ent);
 350         }
 351         else
 352                 result = builtin_diff_combined(&rev, argc, argv,
 353                                              ent, ents);
 354         if (DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
 355                 result = DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0;
 356
 357         if (1 < rev.diffopt.skip_stat_unmatch)
 358                 refresh_index_quietly();
 359         return result;
 360 }