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         if (blob[0].mode == S_IFINVALID)
  78                 blob[0].mode = canon_mode(st.st_mode);
  79
  80         stuff_change(&revs->diffopt,
  81                      blob[0].mode, canon_mode(st.st_mode),
  82                      blob[0].sha1, null_sha1,
  83                      path, path);
  84         diffcore_std(&revs->diffopt);
  85         diff_flush(&revs->diffopt);
  86         return 0;
  87 }
  88
  89 static int builtin_diff_blobs(struct rev_info *revs,
  90                               int argc, const char **argv,
  91                               struct blobinfo *blob)
  92 {
  93         unsigned mode = canon_mode(S_IFREG | 0644);
  94
  95         if (argc > 1)
  96                 usage(builtin_diff_usage);
  97
  98         if (blob[0].mode == S_IFINVALID)
  99                 blob[0].mode = mode;
 100
 101         if (blob[1].mode == S_IFINVALID)
 102                 blob[1].mode = mode;
 103
 104         stuff_change(&revs->diffopt,
 105                      blob[0].mode, blob[1].mode,
 106                      blob[0].sha1, blob[1].sha1,
 107                      blob[0].name, blob[1].name);
 108         diffcore_std(&revs->diffopt);
 109         diff_flush(&revs->diffopt);
 110         return 0;
 111 }
 112
 113 static int builtin_diff_index(struct rev_info *revs,
 114                               int argc, const char **argv)
 115 {
 116         int cached = 0;
 117         while (1 < argc) {
 118                 const char *arg = argv[1];
 119                 if (!strcmp(arg, "--cached"))
 120                         cached = 1;
 121                 else
 122                         usage(builtin_diff_usage);
 123                 argv++; argc--;
 124         }
 125         if (!cached)
 126                 setup_work_tree();
 127         /*
 128          * Make sure there is one revision (i.e. pending object),
 129          * and there is no revision filtering parameters.
 130          */
 131         if (revs->pending.nr != 1 ||
 132             revs->max_count != -1 || revs->min_age != -1 ||
 133             revs->max_age != -1)
 134                 usage(builtin_diff_usage);
 135         if (read_cache() < 0) {
 136                 perror("read_cache");
 137                 return -1;
 138         }
 139         return run_diff_index(revs, cached);
 140 }
 141
 142 static int builtin_diff_tree(struct rev_info *revs,
 143                              int argc, const char **argv,
 144                              struct object_array_entry *ent)
 145 {
 146         const unsigned char *(sha1[2]);
 147         int swap = 0;
 148
 149         if (argc > 1)
 150                 usage(builtin_diff_usage);
 151
 152         /* We saw two trees, ent[0] and ent[1].
 153          * if ent[1] is uninteresting, they are swapped
 154          */
 155         if (ent[1].item->flags & UNINTERESTING)
 156                 swap = 1;
 157         sha1[swap] = ent[0].item->sha1;
 158         sha1[1-swap] = ent[1].item->sha1;
 159         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 160         log_tree_diff_flush(revs);
 161         return 0;
 162 }
 163
 164 static int builtin_diff_combined(struct rev_info *revs,
 165                                  int argc, const char **argv,
 166                                  struct object_array_entry *ent,
 167                                  int ents)
 168 {
 169         const unsigned char (*parent)[20];
 170         int i;
 171
 172         if (argc > 1)
 173                 usage(builtin_diff_usage);
 174
 175         if (!revs->dense_combined_merges && !revs->combine_merges)
 176                 revs->dense_combined_merges = revs->combine_merges = 1;
 177         parent = xmalloc(ents * sizeof(*parent));
 178         for (i = 0; i < ents; i++)
 179                 hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
 180         diff_tree_combined(parent[0], parent + 1, ents - 1,
 181                            revs->dense_combined_merges, revs);
 182         return 0;
 183 }
 184
 185 static void refresh_index_quietly(void)
 186 {
 187         struct lock_file *lock_file;
 188         int fd;
 189
 190         lock_file = xcalloc(1, sizeof(struct lock_file));
 191         fd = hold_locked_index(lock_file, 0);
 192         if (fd < 0)
 193                 return;
 194         discard_cache();
 195         read_cache();
 196         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 197
 198         if (active_cache_changed &&
 199             !write_cache(fd, active_cache, active_nr))
 200                 commit_locked_index(lock_file);
 201
 202         rollback_lock_file(lock_file);
 203 }
 204
 205 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 206 {
 207         int result;
 208         unsigned int options = 0;
 209
 210         while (1 < argc && argv[1][0] == '-') {
 211                 if (!strcmp(argv[1], "--base"))
 212                         revs->max_count = 1;
 213                 else if (!strcmp(argv[1], "--ours"))
 214                         revs->max_count = 2;
 215                 else if (!strcmp(argv[1], "--theirs"))
 216                         revs->max_count = 3;
 217                 else if (!strcmp(argv[1], "-q"))
 218                         options |= DIFF_SILENT_ON_REMOVED;
 219                 else
 220                         return error("invalid option: %s", argv[1]);
 221                 argv++; argc--;
 222         }
 223
 224         /*
 225          * "diff --base" should not combine merges because it was not
 226          * asked to.  "diff -c" should not densify (if the user wants
 227          * dense one, --cc can be explicitly asked for, or just rely
 228          * on the default).
 229          */
 230         if (revs->max_count == -1 && !revs->combine_merges &&
 231             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 232                 revs->combine_merges = revs->dense_combined_merges = 1;
 233
 234         setup_work_tree();
 235         if (read_cache() < 0) {
 236                 perror("read_cache");
 237                 return -1;
 238         }
 239         result = run_diff_files(revs, options);
 240         return diff_result_code(&revs->diffopt, result);
 241 }
 242
 243 int cmd_diff(int argc, const char **argv, const char *prefix)
 244 {
 245         int i;
 246         struct rev_info rev;
 247         struct object_array_entry ent[100];
 248         int ents = 0, blobs = 0, paths = 0;
 249         const char *path = NULL;
 250         struct blobinfo blob[2];
 251         int nongit;
 252         int result = 0;
 253
 254         /*
 255          * We could get N tree-ish in the rev.pending_objects list.
 256          * Also there could be M blobs there, and P pathspecs.
 257          *
 258          * N=0, M=0:
 259          *      cache vs files (diff-files)
 260          * N=0, M=2:
 261          *      compare two random blobs.  P must be zero.
 262          * N=0, M=1, P=1:
 263          *      compare a blob with a working tree file.
 264          *
 265          * N=1, M=0:
 266          *      tree vs cache (diff-index --cached)
 267          *
 268          * N=2, M=0:
 269          *      tree vs tree (diff-tree)
 270          *
 271          * N=0, M=0, P=2:
 272          *      compare two filesystem entities (aka --no-index).
 273          *
 274          * Other cases are errors.
 275          */
 276
 277         prefix = setup_git_directory_gently(&nongit);
 278         git_config(git_diff_ui_config, NULL);
 279
 280         if (diff_use_color_default == -1)
 281                 diff_use_color_default = git_use_color_default;
 282
 283         init_revisions(&rev, prefix);
 284
 285         /* If this is a no-index diff, just run it and exit there. */
 286         diff_no_index(&rev, argc, argv, nongit, prefix);
 287
 288         /* Otherwise, we are doing the usual "git" diff */
 289         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 290
 291         /* Default to let external be used */
 292         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 293
 294         if (nongit)
 295                 die("Not a git repository");
 296         argc = setup_revisions(argc, argv, &rev, NULL);
 297         if (!rev.diffopt.output_format) {
 298                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 299                 if (diff_setup_done(&rev.diffopt) < 0)
 300                         die("diff_setup_done failed");
 301         }
 302
 303         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 304
 305         /*
 306          * If the user asked for our exit code then don't start a
 307          * pager or we would end up reporting its exit code instead.
 308          */
 309         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
 310             check_pager_config("diff") != 0)
 311                 setup_pager();
 312
 313         /*
 314          * Do we have --cached and not have a pending object, then
 315          * default to HEAD by hand.  Eek.
 316          */
 317         if (!rev.pending.nr) {
 318                 int i;
 319                 for (i = 1; i < argc; i++) {
 320                         const char *arg = argv[i];
 321                         if (!strcmp(arg, "--"))
 322                                 break;
 323                         else if (!strcmp(arg, "--cached")) {
 324                                 add_head_to_pending(&rev);
 325                                 if (!rev.pending.nr)
 326                                         die("No HEAD commit to compare with (yet)");
 327                                 break;
 328                         }
 329                 }
 330         }
 331
 332         for (i = 0; i < rev.pending.nr; i++) {
 333                 struct object_array_entry *list = rev.pending.objects+i;
 334                 struct object *obj = list->item;
 335                 const char *name = list->name;
 336                 int flags = (obj->flags & UNINTERESTING);
 337                 if (!obj->parsed)
 338                         obj = parse_object(obj->sha1);
 339                 obj = deref_tag(obj, NULL, 0);
 340                 if (!obj)
 341                         die("invalid object '%s' given.", name);
 342                 if (obj->type == OBJ_COMMIT)
 343                         obj = &((struct commit *)obj)->tree->object;
 344                 if (obj->type == OBJ_TREE) {
 345                         if (ARRAY_SIZE(ent) <= ents)
 346                                 die("more than %d trees given: '%s'",
 347                                     (int) ARRAY_SIZE(ent), name);
 348                         obj->flags |= flags;
 349                         ent[ents].item = obj;
 350                         ent[ents].name = name;
 351                         ents++;
 352                         continue;
 353                 }
 354                 if (obj->type == OBJ_BLOB) {
 355                         if (2 <= blobs)
 356                                 die("more than two blobs given: '%s'", name);
 357                         hashcpy(blob[blobs].sha1, obj->sha1);
 358                         blob[blobs].name = name;
 359                         blob[blobs].mode = list->mode;
 360                         blobs++;
 361                         continue;
 362
 363                 }
 364                 die("unhandled object '%s' given.", name);
 365         }
 366         if (rev.prune_data) {
 367                 const char **pathspec = rev.prune_data;
 368                 while (*pathspec) {
 369                         if (!path)
 370                                 path = *pathspec;
 371                         paths++;
 372                         pathspec++;
 373                 }
 374         }
 375
 376         /*
 377          * Now, do the arguments look reasonable?
 378          */
 379         if (!ents) {
 380                 switch (blobs) {
 381                 case 0:
 382                         result = builtin_diff_files(&rev, argc, argv);
 383                         break;
 384                 case 1:
 385                         if (paths != 1)
 386                                 usage(builtin_diff_usage);
 387                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 388                         break;
 389                 case 2:
 390                         if (paths)
 391                                 usage(builtin_diff_usage);
 392                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 393                         break;
 394                 default:
 395                         usage(builtin_diff_usage);
 396                 }
 397         }
 398         else if (blobs)
 399                 usage(builtin_diff_usage);
 400         else if (ents == 1)
 401                 result = builtin_diff_index(&rev, argc, argv);
 402         else if (ents == 2)
 403                 result = builtin_diff_tree(&rev, argc, argv, ent);
 404         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 405                 /* diff A...B where there is one sane merge base between
 406                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 407                  * and ent[2] == B.  Show diff between the base and B.
 408                  */
 409                 ent[1] = ent[2];
 410                 result = builtin_diff_tree(&rev, argc, argv, ent);
 411         }
 412         else
 413                 result = builtin_diff_combined(&rev, argc, argv,
 414                                              ent, ents);
 415         result = diff_result_code(&rev.diffopt, result);
 416         if (1 < rev.diffopt.skip_stat_unmatch)
 417                 refresh_index_quietly();
 418         return result;
 419 }