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 (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 void add_head(struct rev_info *revs)
 180 {
 181         unsigned char sha1[20];
 182         struct object *obj;
 183         if (get_sha1("HEAD", sha1))
 184                 return;
 185         obj = parse_object(sha1);
 186         if (!obj)
 187                 return;
 188         add_pending_object(revs, obj, "HEAD");
 189 }
 190
 191 static void refresh_index_quietly(void)
 192 {
 193         struct lock_file *lock_file;
 194         int fd;
 195
 196         lock_file = xcalloc(1, sizeof(struct lock_file));
 197         fd = hold_locked_index(lock_file, 0);
 198         if (fd < 0)
 199                 return;
 200         discard_cache();
 201         read_cache();
 202         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 203
 204         if (active_cache_changed &&
 205             !write_cache(fd, active_cache, active_nr) && !close(fd))
 206                 commit_locked_index(lock_file);
 207
 208         rollback_lock_file(lock_file);
 209 }
 210
 211 int cmd_diff(int argc, const char **argv, const char *prefix)
 212 {
 213         int i;
 214         struct rev_info rev;
 215         struct object_array_entry ent[100];
 216         int ents = 0, blobs = 0, paths = 0;
 217         const char *path = NULL;
 218         struct blobinfo blob[2];
 219         int nongit = 0;
 220         int result = 0;
 221
 222         /*
 223          * We could get N tree-ish in the rev.pending_objects list.
 224          * Also there could be M blobs there, and P pathspecs.
 225          *
 226          * N=0, M=0:
 227          *      cache vs files (diff-files)
 228          * N=0, M=2:
 229          *      compare two random blobs.  P must be zero.
 230          * N=0, M=1, P=1:
 231          *      compare a blob with a working tree file.
 232          *
 233          * N=1, M=0:
 234          *      tree vs cache (diff-index --cached)
 235          *
 236          * N=2, M=0:
 237          *      tree vs tree (diff-tree)
 238          *
 239          * Other cases are errors.
 240          */
 241
 242         prefix = setup_git_directory_gently(&nongit);
 243         git_config(git_diff_ui_config);
 244         init_revisions(&rev, prefix);
 245         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 246
 247         if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
 248                 argc = 0;
 249         else
 250                 argc = setup_revisions(argc, argv, &rev, NULL);
 251         if (!rev.diffopt.output_format) {
 252                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 253                 if (diff_setup_done(&rev.diffopt) < 0)
 254                         die("diff_setup_done failed");
 255         }
 256         rev.diffopt.allow_external = 1;
 257         rev.diffopt.recursive = 1;
 258
 259         /* If the user asked for our exit code then don't start a
 260          * pager or we would end up reporting its exit code instead.
 261          */
 262         if (!rev.diffopt.exit_with_status)
 263                 setup_pager();
 264
 265         /* Do we have --cached and not have a pending object, then
 266          * default to HEAD by hand.  Eek.
 267          */
 268         if (!rev.pending.nr) {
 269                 int i;
 270                 for (i = 1; i < argc; i++) {
 271                         const char *arg = argv[i];
 272                         if (!strcmp(arg, "--"))
 273                                 break;
 274                         else if (!strcmp(arg, "--cached")) {
 275                                 add_head(&rev);
 276                                 if (!rev.pending.nr)
 277                                         die("No HEAD commit to compare with (yet)");
 278                                 break;
 279                         }
 280                 }
 281         }
 282
 283         for (i = 0; i < rev.pending.nr; i++) {
 284                 struct object_array_entry *list = rev.pending.objects+i;
 285                 struct object *obj = list->item;
 286                 const char *name = list->name;
 287                 int flags = (obj->flags & UNINTERESTING);
 288                 if (!obj->parsed)
 289                         obj = parse_object(obj->sha1);
 290                 obj = deref_tag(obj, NULL, 0);
 291                 if (!obj)
 292                         die("invalid object '%s' given.", name);
 293                 if (obj->type == OBJ_COMMIT)
 294                         obj = &((struct commit *)obj)->tree->object;
 295                 if (obj->type == OBJ_TREE) {
 296                         if (ARRAY_SIZE(ent) <= ents)
 297                                 die("more than %d trees given: '%s'",
 298                                     (int) ARRAY_SIZE(ent), name);
 299                         obj->flags |= flags;
 300                         ent[ents].item = obj;
 301                         ent[ents].name = name;
 302                         ents++;
 303                         continue;
 304                 }
 305                 if (obj->type == OBJ_BLOB) {
 306                         if (2 <= blobs)
 307                                 die("more than two blobs given: '%s'", name);
 308                         hashcpy(blob[blobs].sha1, obj->sha1);
 309                         blob[blobs].name = name;
 310                         blob[blobs].mode = list->mode;
 311                         blobs++;
 312                         continue;
 313
 314                 }
 315                 die("unhandled object '%s' given.", name);
 316         }
 317         if (rev.prune_data) {
 318                 const char **pathspec = rev.prune_data;
 319                 while (*pathspec) {
 320                         if (!path)
 321                                 path = *pathspec;
 322                         paths++;
 323                         pathspec++;
 324                 }
 325         }
 326
 327         /*
 328          * Now, do the arguments look reasonable?
 329          */
 330         if (!ents) {
 331                 switch (blobs) {
 332                 case 0:
 333                         result = run_diff_files_cmd(&rev, argc, argv);
 334                         break;
 335                 case 1:
 336                         if (paths != 1)
 337                                 usage(builtin_diff_usage);
 338                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 339                         break;
 340                 case 2:
 341                         if (paths)
 342                                 usage(builtin_diff_usage);
 343                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 344                         break;
 345                 default:
 346                         usage(builtin_diff_usage);
 347                 }
 348         }
 349         else if (blobs)
 350                 usage(builtin_diff_usage);
 351         else if (ents == 1)
 352                 result = builtin_diff_index(&rev, argc, argv);
 353         else if (ents == 2)
 354                 result = builtin_diff_tree(&rev, argc, argv, ent);
 355         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 356                 /* diff A...B where there is one sane merge base between
 357                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 358                  * and ent[2] == B.  Show diff between the base and B.
 359                  */
 360                 ent[1] = ent[2];
 361                 result = builtin_diff_tree(&rev, argc, argv, ent);
 362         }
 363         else
 364                 result = builtin_diff_combined(&rev, argc, argv,
 365                                              ent, ents);
 366         if (rev.diffopt.exit_with_status)
 367                 result = rev.diffopt.has_changes;
 368
 369         if (1 < rev.diffopt.skip_stat_unmatch)
 370                 refresh_index_quietly();
 371         return result;
 372 }