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         one = alloc_filespec(old_name);
  48         two = alloc_filespec(new_name);
  49         fill_filespec(one, old_sha1, old_mode);
  50         fill_filespec(two, new_sha1, new_mode);
  51
  52         /* NEEDSWORK: shouldn't this part of diffopt??? */
  53         diff_queue(&diff_queued_diff, one, two);
  54 }
  55
  56 static int builtin_diff_b_f(struct rev_info *revs,
  57                             int argc, const char **argv,
  58                             struct blobinfo *blob,
  59                             const char *path)
  60 {
  61         /* Blob vs file in the working tree*/
  62         struct stat st;
  63
  64         if (argc > 1)
  65                 usage(builtin_diff_usage);
  66
  67         if (lstat(path, &st))
  68                 die("'%s': %s", path, strerror(errno));
  69         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  70                 die("'%s': not a regular file or symlink", path);
  71
  72         if (blob[0].mode == S_IFINVALID)
  73                 blob[0].mode = canon_mode(st.st_mode);
  74
  75         stuff_change(&revs->diffopt,
  76                      blob[0].mode, canon_mode(st.st_mode),
  77                      blob[0].sha1, null_sha1,
  78                      path, path);
  79         diffcore_std(&revs->diffopt);
  80         diff_flush(&revs->diffopt);
  81         return 0;
  82 }
  83
  84 static int builtin_diff_blobs(struct rev_info *revs,
  85                               int argc, const char **argv,
  86                               struct blobinfo *blob)
  87 {
  88         unsigned mode = canon_mode(S_IFREG | 0644);
  89
  90         if (argc > 1)
  91                 usage(builtin_diff_usage);
  92
  93         if (blob[0].mode == S_IFINVALID)
  94                 blob[0].mode = mode;
  95
  96         if (blob[1].mode == S_IFINVALID)
  97                 blob[1].mode = mode;
  98
  99         stuff_change(&revs->diffopt,
 100                      blob[0].mode, blob[1].mode,
 101                      blob[0].sha1, blob[1].sha1,
 102                      blob[0].name, blob[1].name);
 103         diffcore_std(&revs->diffopt);
 104         diff_flush(&revs->diffopt);
 105         return 0;
 106 }
 107
 108 static int builtin_diff_index(struct rev_info *revs,
 109                               int argc, const char **argv)
 110 {
 111         int cached = 0;
 112         while (1 < argc) {
 113                 const char *arg = argv[1];
 114                 if (!strcmp(arg, "--cached"))
 115                         cached = 1;
 116                 else
 117                         usage(builtin_diff_usage);
 118                 argv++; argc--;
 119         }
 120         /*
 121          * Make sure there is one revision (i.e. pending object),
 122          * and there is no revision filtering parameters.
 123          */
 124         if (revs->pending.nr != 1 ||
 125             revs->max_count != -1 || revs->min_age != -1 ||
 126             revs->max_age != -1)
 127                 usage(builtin_diff_usage);
 128         if (read_cache() < 0) {
 129                 perror("read_cache");
 130                 return -1;
 131         }
 132         return run_diff_index(revs, cached);
 133 }
 134
 135 static int builtin_diff_tree(struct rev_info *revs,
 136                              int argc, const char **argv,
 137                              struct object_array_entry *ent)
 138 {
 139         const unsigned char *(sha1[2]);
 140         int swap = 0;
 141
 142         if (argc > 1)
 143                 usage(builtin_diff_usage);
 144
 145         /* We saw two trees, ent[0] and ent[1].
 146          * if ent[1] is uninteresting, they are swapped
 147          */
 148         if (ent[1].item->flags & UNINTERESTING)
 149                 swap = 1;
 150         sha1[swap] = ent[0].item->sha1;
 151         sha1[1-swap] = ent[1].item->sha1;
 152         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 153         log_tree_diff_flush(revs);
 154         return 0;
 155 }
 156
 157 static int builtin_diff_combined(struct rev_info *revs,
 158                                  int argc, const char **argv,
 159                                  struct object_array_entry *ent,
 160                                  int ents)
 161 {
 162         const unsigned char (*parent)[20];
 163         int i;
 164
 165         if (argc > 1)
 166                 usage(builtin_diff_usage);
 167
 168         if (!revs->dense_combined_merges && !revs->combine_merges)
 169                 revs->dense_combined_merges = revs->combine_merges = 1;
 170         parent = xmalloc(ents * sizeof(*parent));
 171         /* Again, the revs are all reverse */
 172         for (i = 0; i < ents; i++)
 173                 hashcpy((unsigned char *)(parent + i),
 174                         ent[ents - 1 - i].item->sha1);
 175         diff_tree_combined(parent[0], parent + 1, ents - 1,
 176                            revs->dense_combined_merges, revs);
 177         return 0;
 178 }
 179
 180 static void refresh_index_quietly(void)
 181 {
 182         struct lock_file *lock_file;
 183         int fd;
 184
 185         lock_file = xcalloc(1, sizeof(struct lock_file));
 186         fd = hold_locked_index(lock_file, 0);
 187         if (fd < 0)
 188                 return;
 189         discard_cache();
 190         read_cache();
 191         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 192
 193         if (active_cache_changed &&
 194             !write_cache(fd, active_cache, active_nr))
 195                 commit_locked_index(lock_file);
 196
 197         rollback_lock_file(lock_file);
 198 }
 199
 200 int cmd_diff(int argc, const char **argv, const char *prefix)
 201 {
 202         int i;
 203         struct rev_info rev;
 204         struct object_array_entry ent[100];
 205         int ents = 0, blobs = 0, paths = 0;
 206         const char *path = NULL;
 207         struct blobinfo blob[2];
 208         int nongit = 0;
 209         int result = 0;
 210
 211         /*
 212          * We could get N tree-ish in the rev.pending_objects list.
 213          * Also there could be M blobs there, and P pathspecs.
 214          *
 215          * N=0, M=0:
 216          *      cache vs files (diff-files)
 217          * N=0, M=2:
 218          *      compare two random blobs.  P must be zero.
 219          * N=0, M=1, P=1:
 220          *      compare a blob with a working tree file.
 221          *
 222          * N=1, M=0:
 223          *      tree vs cache (diff-index --cached)
 224          *
 225          * N=2, M=0:
 226          *      tree vs tree (diff-tree)
 227          *
 228          * Other cases are errors.
 229          */
 230
 231         prefix = setup_git_directory_gently(&nongit);
 232         git_config(git_diff_ui_config);
 233
 234         if (diff_use_color_default == -1)
 235                 diff_use_color_default = git_use_color_default;
 236
 237         init_revisions(&rev, prefix);
 238         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 239
 240         if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
 241                 argc = 0;
 242         else
 243                 argc = setup_revisions(argc, argv, &rev, NULL);
 244         if (!rev.diffopt.output_format) {
 245                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 246                 if (diff_setup_done(&rev.diffopt) < 0)
 247                         die("diff_setup_done failed");
 248         }
 249         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 250         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 251
 252         /*
 253          * If the user asked for our exit code then don't start a
 254          * pager or we would end up reporting its exit code instead.
 255          */
 256         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
 257                 setup_pager();
 258
 259         /* Do we have --cached and not have a pending object, then
 260          * default to HEAD by hand.  Eek.
 261          */
 262         if (!rev.pending.nr) {
 263                 int i;
 264                 for (i = 1; i < argc; i++) {
 265                         const char *arg = argv[i];
 266                         if (!strcmp(arg, "--"))
 267                                 break;
 268                         else if (!strcmp(arg, "--cached")) {
 269                                 add_head_to_pending(&rev);
 270                                 if (!rev.pending.nr)
 271                                         die("No HEAD commit to compare with (yet)");
 272                                 break;
 273                         }
 274                 }
 275         }
 276
 277         for (i = 0; i < rev.pending.nr; i++) {
 278                 struct object_array_entry *list = rev.pending.objects+i;
 279                 struct object *obj = list->item;
 280                 const char *name = list->name;
 281                 int flags = (obj->flags & UNINTERESTING);
 282                 if (!obj->parsed)
 283                         obj = parse_object(obj->sha1);
 284                 obj = deref_tag(obj, NULL, 0);
 285                 if (!obj)
 286                         die("invalid object '%s' given.", name);
 287                 if (obj->type == OBJ_COMMIT)
 288                         obj = &((struct commit *)obj)->tree->object;
 289                 if (obj->type == OBJ_TREE) {
 290                         if (ARRAY_SIZE(ent) <= ents)
 291                                 die("more than %d trees given: '%s'",
 292                                     (int) ARRAY_SIZE(ent), name);
 293                         obj->flags |= flags;
 294                         ent[ents].item = obj;
 295                         ent[ents].name = name;
 296                         ents++;
 297                         continue;
 298                 }
 299                 if (obj->type == OBJ_BLOB) {
 300                         if (2 <= blobs)
 301                                 die("more than two blobs given: '%s'", name);
 302                         hashcpy(blob[blobs].sha1, obj->sha1);
 303                         blob[blobs].name = name;
 304                         blob[blobs].mode = list->mode;
 305                         blobs++;
 306                         continue;
 307
 308                 }
 309                 die("unhandled object '%s' given.", name);
 310         }
 311         if (rev.prune_data) {
 312                 const char **pathspec = rev.prune_data;
 313                 while (*pathspec) {
 314                         if (!path)
 315                                 path = *pathspec;
 316                         paths++;
 317                         pathspec++;
 318                 }
 319         }
 320
 321         /*
 322          * Now, do the arguments look reasonable?
 323          */
 324         if (!ents) {
 325                 switch (blobs) {
 326                 case 0:
 327                         result = run_diff_files_cmd(&rev, argc, argv);
 328                         break;
 329                 case 1:
 330                         if (paths != 1)
 331                                 usage(builtin_diff_usage);
 332                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 333                         break;
 334                 case 2:
 335                         if (paths)
 336                                 usage(builtin_diff_usage);
 337                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 338                         break;
 339                 default:
 340                         usage(builtin_diff_usage);
 341                 }
 342         }
 343         else if (blobs)
 344                 usage(builtin_diff_usage);
 345         else if (ents == 1)
 346                 result = builtin_diff_index(&rev, argc, argv);
 347         else if (ents == 2)
 348                 result = builtin_diff_tree(&rev, argc, argv, ent);
 349         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 350                 /* diff A...B where there is one sane merge base between
 351                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 352                  * and ent[2] == B.  Show diff between the base and B.
 353                  */
 354                 ent[1] = ent[2];
 355                 result = builtin_diff_tree(&rev, argc, argv, ent);
 356         }
 357         else
 358                 result = builtin_diff_combined(&rev, argc, argv,
 359                                              ent, ents);
 360         result = diff_result_code(&rev.diffopt, result);
 361         if (1 < rev.diffopt.skip_stat_unmatch)
 362                 refresh_index_quietly();
 363         return result;
 364 }