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
  47         if (opt->prefix &&
  48             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  49              strncmp(new_name, opt->prefix, opt->prefix_length)))
  50                 return;
  51
  52         one = alloc_filespec(old_name);
  53         two = alloc_filespec(new_name);
  54         fill_filespec(one, old_sha1, old_mode);
  55         fill_filespec(two, new_sha1, new_mode);
  56
  57         diff_queue(&diff_queued_diff, one, two);
  58 }
  59
  60 static int builtin_diff_b_f(struct rev_info *revs,
  61                             int argc, const char **argv,
  62                             struct blobinfo *blob,
  63                             const char *path)
  64 {
  65         /* Blob vs file in the working tree*/
  66         struct stat st;
  67
  68         if (argc > 1)
  69                 usage(builtin_diff_usage);
  70
  71         if (lstat(path, &st))
  72                 die("'%s': %s", path, strerror(errno));
  73         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  74                 die("'%s': not a regular file or symlink", path);
  75
  76         if (blob[0].mode == S_IFINVALID)
  77                 blob[0].mode = canon_mode(st.st_mode);
  78
  79         stuff_change(&revs->diffopt,
  80                      blob[0].mode, canon_mode(st.st_mode),
  81                      blob[0].sha1, null_sha1,
  82                      path, path);
  83         diffcore_std(&revs->diffopt);
  84         diff_flush(&revs->diffopt);
  85         return 0;
  86 }
  87
  88 static int builtin_diff_blobs(struct rev_info *revs,
  89                               int argc, const char **argv,
  90                               struct blobinfo *blob)
  91 {
  92         unsigned mode = canon_mode(S_IFREG | 0644);
  93
  94         if (argc > 1)
  95                 usage(builtin_diff_usage);
  96
  97         if (blob[0].mode == S_IFINVALID)
  98                 blob[0].mode = mode;
  99
 100         if (blob[1].mode == S_IFINVALID)
 101                 blob[1].mode = mode;
 102
 103         stuff_change(&revs->diffopt,
 104                      blob[0].mode, blob[1].mode,
 105                      blob[0].sha1, blob[1].sha1,
 106                      blob[0].name, blob[1].name);
 107         diffcore_std(&revs->diffopt);
 108         diff_flush(&revs->diffopt);
 109         return 0;
 110 }
 111
 112 static int builtin_diff_index(struct rev_info *revs,
 113                               int argc, const char **argv)
 114 {
 115         int cached = 0;
 116         while (1 < argc) {
 117                 const char *arg = argv[1];
 118                 if (!strcmp(arg, "--cached"))
 119                         cached = 1;
 120                 else
 121                         usage(builtin_diff_usage);
 122                 argv++; argc--;
 123         }
 124         /*
 125          * Make sure there is one revision (i.e. pending object),
 126          * and there is no revision filtering parameters.
 127          */
 128         if (revs->pending.nr != 1 ||
 129             revs->max_count != -1 || revs->min_age != -1 ||
 130             revs->max_age != -1)
 131                 usage(builtin_diff_usage);
 132         if (read_cache() < 0) {
 133                 perror("read_cache");
 134                 return -1;
 135         }
 136         return run_diff_index(revs, cached);
 137 }
 138
 139 static int builtin_diff_tree(struct rev_info *revs,
 140                              int argc, const char **argv,
 141                              struct object_array_entry *ent)
 142 {
 143         const unsigned char *(sha1[2]);
 144         int swap = 0;
 145
 146         if (argc > 1)
 147                 usage(builtin_diff_usage);
 148
 149         /* We saw two trees, ent[0] and ent[1].
 150          * if ent[1] is uninteresting, they are swapped
 151          */
 152         if (ent[1].item->flags & UNINTERESTING)
 153                 swap = 1;
 154         sha1[swap] = ent[0].item->sha1;
 155         sha1[1-swap] = ent[1].item->sha1;
 156         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 157         log_tree_diff_flush(revs);
 158         return 0;
 159 }
 160
 161 static int builtin_diff_combined(struct rev_info *revs,
 162                                  int argc, const char **argv,
 163                                  struct object_array_entry *ent,
 164                                  int ents)
 165 {
 166         const unsigned char (*parent)[20];
 167         int i;
 168
 169         if (argc > 1)
 170                 usage(builtin_diff_usage);
 171
 172         if (!revs->dense_combined_merges && !revs->combine_merges)
 173                 revs->dense_combined_merges = revs->combine_merges = 1;
 174         parent = xmalloc(ents * sizeof(*parent));
 175         /* Again, the revs are all reverse */
 176         for (i = 0; i < ents; i++)
 177                 hashcpy((unsigned char *)(parent + i),
 178                         ent[ents - 1 - i].item->sha1);
 179         diff_tree_combined(parent[0], parent + 1, ents - 1,
 180                            revs->dense_combined_merges, revs);
 181         return 0;
 182 }
 183
 184 static void refresh_index_quietly(void)
 185 {
 186         struct lock_file *lock_file;
 187         int fd;
 188
 189         lock_file = xcalloc(1, sizeof(struct lock_file));
 190         fd = hold_locked_index(lock_file, 0);
 191         if (fd < 0)
 192                 return;
 193         discard_cache();
 194         read_cache();
 195         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 196
 197         if (active_cache_changed &&
 198             !write_cache(fd, active_cache, active_nr))
 199                 commit_locked_index(lock_file);
 200
 201         rollback_lock_file(lock_file);
 202 }
 203
 204 int cmd_diff(int argc, const char **argv, const char *prefix)
 205 {
 206         int i;
 207         struct rev_info rev;
 208         struct object_array_entry ent[100];
 209         int ents = 0, blobs = 0, paths = 0;
 210         const char *path = NULL;
 211         struct blobinfo blob[2];
 212         int nongit = 0;
 213         int result = 0;
 214
 215         /*
 216          * We could get N tree-ish in the rev.pending_objects list.
 217          * Also there could be M blobs there, and P pathspecs.
 218          *
 219          * N=0, M=0:
 220          *      cache vs files (diff-files)
 221          * N=0, M=2:
 222          *      compare two random blobs.  P must be zero.
 223          * N=0, M=1, P=1:
 224          *      compare a blob with a working tree file.
 225          *
 226          * N=1, M=0:
 227          *      tree vs cache (diff-index --cached)
 228          *
 229          * N=2, M=0:
 230          *      tree vs tree (diff-tree)
 231          *
 232          * Other cases are errors.
 233          */
 234
 235         prefix = setup_git_directory_gently(&nongit);
 236         git_config(git_diff_ui_config);
 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         if (rev.diffopt.prefix && nongit) {
 250                 rev.diffopt.prefix = NULL;
 251                 rev.diffopt.prefix_length = 0;
 252         }
 253         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 254         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 255
 256         /*
 257          * If the user asked for our exit code then don't start a
 258          * pager or we would end up reporting its exit code instead.
 259          */
 260         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
 261                 setup_pager();
 262
 263         /* Do we have --cached and not have a pending object, then
 264          * default to HEAD by hand.  Eek.
 265          */
 266         if (!rev.pending.nr) {
 267                 int i;
 268                 for (i = 1; i < argc; i++) {
 269                         const char *arg = argv[i];
 270                         if (!strcmp(arg, "--"))
 271                                 break;
 272                         else if (!strcmp(arg, "--cached")) {
 273                                 add_head_to_pending(&rev);
 274                                 if (!rev.pending.nr)
 275                                         die("No HEAD commit to compare with (yet)");
 276                                 break;
 277                         }
 278                 }
 279         }
 280
 281         for (i = 0; i < rev.pending.nr; i++) {
 282                 struct object_array_entry *list = rev.pending.objects+i;
 283                 struct object *obj = list->item;
 284                 const char *name = list->name;
 285                 int flags = (obj->flags & UNINTERESTING);
 286                 if (!obj->parsed)
 287                         obj = parse_object(obj->sha1);
 288                 obj = deref_tag(obj, NULL, 0);
 289                 if (!obj)
 290                         die("invalid object '%s' given.", name);
 291                 if (obj->type == OBJ_COMMIT)
 292                         obj = &((struct commit *)obj)->tree->object;
 293                 if (obj->type == OBJ_TREE) {
 294                         if (ARRAY_SIZE(ent) <= ents)
 295                                 die("more than %d trees given: '%s'",
 296                                     (int) ARRAY_SIZE(ent), name);
 297                         obj->flags |= flags;
 298                         ent[ents].item = obj;
 299                         ent[ents].name = name;
 300                         ents++;
 301                         continue;
 302                 }
 303                 if (obj->type == OBJ_BLOB) {
 304                         if (2 <= blobs)
 305                                 die("more than two blobs given: '%s'", name);
 306                         hashcpy(blob[blobs].sha1, obj->sha1);
 307                         blob[blobs].name = name;
 308                         blob[blobs].mode = list->mode;
 309                         blobs++;
 310                         continue;
 311
 312                 }
 313                 die("unhandled object '%s' given.", name);
 314         }
 315         if (rev.prune_data) {
 316                 const char **pathspec = rev.prune_data;
 317                 while (*pathspec) {
 318                         if (!path)
 319                                 path = *pathspec;
 320                         paths++;
 321                         pathspec++;
 322                 }
 323         }
 324
 325         /*
 326          * Now, do the arguments look reasonable?
 327          */
 328         if (!ents) {
 329                 switch (blobs) {
 330                 case 0:
 331                         result = run_diff_files_cmd(&rev, argc, argv);
 332                         break;
 333                 case 1:
 334                         if (paths != 1)
 335                                 usage(builtin_diff_usage);
 336                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 337                         break;
 338                 case 2:
 339                         if (paths)
 340                                 usage(builtin_diff_usage);
 341                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 342                         break;
 343                 default:
 344                         usage(builtin_diff_usage);
 345                 }
 346         }
 347         else if (blobs)
 348                 usage(builtin_diff_usage);
 349         else if (ents == 1)
 350                 result = builtin_diff_index(&rev, argc, argv);
 351         else if (ents == 2)
 352                 result = builtin_diff_tree(&rev, argc, argv, ent);
 353         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 354                 /* diff A...B where there is one sane merge base between
 355                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
 356                  * and ent[2] == B.  Show diff between the base and B.
 357                  */
 358                 ent[1] = ent[2];
 359                 result = builtin_diff_tree(&rev, argc, argv, ent);
 360         }
 361         else
 362                 result = builtin_diff_combined(&rev, argc, argv,
 363                                              ent, ents);
 364         result = diff_result_code(&rev.diffopt, result);
 365         if (1 < rev.diffopt.skip_stat_unmatch)
 366                 refresh_index_quietly();
 367         return result;
 368 }