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 #include "submodule.h"
  17 #include "sha1-array.h"
  18
  19 struct blobinfo {
  20         unsigned char sha1[20];
  21         const char *name;
  22         unsigned mode;
  23 };
  24
  25 static const char builtin_diff_usage[] =
  26 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  27
  28 static void stuff_change(struct diff_options *opt,
  29                          unsigned old_mode, unsigned new_mode,
  30                          const unsigned char *old_sha1,
  31                          const unsigned char *new_sha1,
  32                          int old_sha1_valid,
  33                          int new_sha1_valid,
  34                          const char *old_name,
  35                          const char *new_name)
  36 {
  37         struct diff_filespec *one, *two;
  38
  39         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  40             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  41                 return;
  42
  43         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  44                 unsigned tmp;
  45                 const unsigned char *tmp_u;
  46                 const char *tmp_c;
  47                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  48                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  49                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  50         }
  51
  52         if (opt->prefix &&
  53             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  54              strncmp(new_name, opt->prefix, opt->prefix_length)))
  55                 return;
  56
  57         one = alloc_filespec(old_name);
  58         two = alloc_filespec(new_name);
  59         fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
  60         fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
  61
  62         diff_queue(&diff_queued_diff, one, two);
  63 }
  64
  65 static int builtin_diff_b_f(struct rev_info *revs,
  66                             int argc, const char **argv,
  67                             struct blobinfo *blob)
  68 {
  69         /* Blob vs file in the working tree*/
  70         struct stat st;
  71         const char *path;
  72
  73         if (argc > 1)
  74                 usage(builtin_diff_usage);
  75
  76         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
  77         path = revs->prune_data.items[0].match;
  78
  79         if (lstat(path, &st))
  80                 die_errno(_("failed to stat '%s'"), path);
  81         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  82                 die(_("'%s': not a regular file or symlink"), path);
  83
  84         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  85
  86         if (blob[0].mode == S_IFINVALID)
  87                 blob[0].mode = canon_mode(st.st_mode);
  88
  89         stuff_change(&revs->diffopt,
  90                      blob[0].mode, canon_mode(st.st_mode),
  91                      blob[0].sha1, null_sha1,
  92                      1, 0,
  93                      path, path);
  94         diffcore_std(&revs->diffopt);
  95         diff_flush(&revs->diffopt);
  96         return 0;
  97 }
  98
  99 static int builtin_diff_blobs(struct rev_info *revs,
 100                               int argc, const char **argv,
 101                               struct blobinfo *blob)
 102 {
 103         unsigned mode = canon_mode(S_IFREG | 0644);
 104
 105         if (argc > 1)
 106                 usage(builtin_diff_usage);
 107
 108         if (blob[0].mode == S_IFINVALID)
 109                 blob[0].mode = mode;
 110
 111         if (blob[1].mode == S_IFINVALID)
 112                 blob[1].mode = mode;
 113
 114         stuff_change(&revs->diffopt,
 115                      blob[0].mode, blob[1].mode,
 116                      blob[0].sha1, blob[1].sha1,
 117                      1, 1,
 118                      blob[0].name, blob[1].name);
 119         diffcore_std(&revs->diffopt);
 120         diff_flush(&revs->diffopt);
 121         return 0;
 122 }
 123
 124 static int builtin_diff_index(struct rev_info *revs,
 125                               int argc, const char **argv)
 126 {
 127         int cached = 0;
 128         while (1 < argc) {
 129                 const char *arg = argv[1];
 130                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 131                         cached = 1;
 132                 else
 133                         usage(builtin_diff_usage);
 134                 argv++; argc--;
 135         }
 136         /*
 137          * Make sure there is one revision (i.e. pending object),
 138          * and there is no revision filtering parameters.
 139          */
 140         if (revs->pending.nr != 1 ||
 141             revs->max_count != -1 || revs->min_age != -1 ||
 142             revs->max_age != -1)
 143                 usage(builtin_diff_usage);
 144         if (!cached) {
 145                 setup_work_tree();
 146                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 147                         perror("read_cache_preload");
 148                         return -1;
 149                 }
 150         } else if (read_cache() < 0) {
 151                 perror("read_cache");
 152                 return -1;
 153         }
 154         return run_diff_index(revs, cached);
 155 }
 156
 157 static int builtin_diff_tree(struct rev_info *revs,
 158                              int argc, const char **argv,
 159                              struct object_array_entry *ent0,
 160                              struct object_array_entry *ent1)
 161 {
 162         const unsigned char *(sha1[2]);
 163         int swap = 0;
 164
 165         if (argc > 1)
 166                 usage(builtin_diff_usage);
 167
 168         /*
 169          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 170          * swap them.
 171          */
 172         if (ent1->item->flags & UNINTERESTING)
 173                 swap = 1;
 174         sha1[swap] = ent0->item->sha1;
 175         sha1[1 - swap] = ent1->item->sha1;
 176         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 177         log_tree_diff_flush(revs);
 178         return 0;
 179 }
 180
 181 static int builtin_diff_combined(struct rev_info *revs,
 182                                  int argc, const char **argv,
 183                                  struct object_array_entry *ent,
 184                                  int ents)
 185 {
 186         struct sha1_array parents = SHA1_ARRAY_INIT;
 187         int i;
 188
 189         if (argc > 1)
 190                 usage(builtin_diff_usage);
 191
 192         if (!revs->dense_combined_merges && !revs->combine_merges)
 193                 revs->dense_combined_merges = revs->combine_merges = 1;
 194         for (i = 1; i < ents; i++)
 195                 sha1_array_append(&parents, ent[i].item->sha1);
 196         diff_tree_combined(ent[0].item->sha1, &parents,
 197                            revs->dense_combined_merges, revs);
 198         sha1_array_clear(&parents);
 199         return 0;
 200 }
 201
 202 static void refresh_index_quietly(void)
 203 {
 204         struct lock_file *lock_file;
 205         int fd;
 206
 207         lock_file = xcalloc(1, sizeof(struct lock_file));
 208         fd = hold_locked_index(lock_file, 0);
 209         if (fd < 0)
 210                 return;
 211         discard_cache();
 212         read_cache();
 213         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 214         update_index_if_able(&the_index, lock_file);
 215 }
 216
 217 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 218 {
 219         unsigned int options = 0;
 220
 221         while (1 < argc && argv[1][0] == '-') {
 222                 if (!strcmp(argv[1], "--base"))
 223                         revs->max_count = 1;
 224                 else if (!strcmp(argv[1], "--ours"))
 225                         revs->max_count = 2;
 226                 else if (!strcmp(argv[1], "--theirs"))
 227                         revs->max_count = 3;
 228                 else if (!strcmp(argv[1], "-q"))
 229                         options |= DIFF_SILENT_ON_REMOVED;
 230                 else if (!strcmp(argv[1], "-h"))
 231                         usage(builtin_diff_usage);
 232                 else
 233                         return error(_("invalid option: %s"), argv[1]);
 234                 argv++; argc--;
 235         }
 236
 237         /*
 238          * "diff --base" should not combine merges because it was not
 239          * asked to.  "diff -c" should not densify (if the user wants
 240          * dense one, --cc can be explicitly asked for, or just rely
 241          * on the default).
 242          */
 243         if (revs->max_count == -1 && !revs->combine_merges &&
 244             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 245                 revs->combine_merges = revs->dense_combined_merges = 1;
 246
 247         setup_work_tree();
 248         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 249                 perror("read_cache_preload");
 250                 return -1;
 251         }
 252         return run_diff_files(revs, options);
 253 }
 254
 255 int cmd_diff(int argc, const char **argv, const char *prefix)
 256 {
 257         int i;
 258         struct rev_info rev;
 259         struct object_array ent = OBJECT_ARRAY_INIT;
 260         int blobs = 0, paths = 0;
 261         struct blobinfo blob[2];
 262         int nongit;
 263         int result = 0;
 264
 265         /*
 266          * We could get N tree-ish in the rev.pending_objects list.
 267          * Also there could be M blobs there, and P pathspecs.
 268          *
 269          * N=0, M=0:
 270          *      cache vs files (diff-files)
 271          * N=0, M=2:
 272          *      compare two random blobs.  P must be zero.
 273          * N=0, M=1, P=1:
 274          *      compare a blob with a working tree file.
 275          *
 276          * N=1, M=0:
 277          *      tree vs cache (diff-index --cached)
 278          *
 279          * N=2, M=0:
 280          *      tree vs tree (diff-tree)
 281          *
 282          * N=0, M=0, P=2:
 283          *      compare two filesystem entities (aka --no-index).
 284          *
 285          * Other cases are errors.
 286          */
 287
 288         prefix = setup_git_directory_gently(&nongit);
 289         gitmodules_config();
 290         git_config(git_diff_ui_config, NULL);
 291
 292         init_revisions(&rev, prefix);
 293
 294         /* If this is a no-index diff, just run it and exit there. */
 295         diff_no_index(&rev, argc, argv, nongit, prefix);
 296
 297         /* Otherwise, we are doing the usual "git" diff */
 298         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 299
 300         /* Scale to real terminal size and respect statGraphWidth config */
 301         rev.diffopt.stat_width = -1;
 302         rev.diffopt.stat_graph_width = -1;
 303
 304         /* Default to let external and textconv be used */
 305         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 306         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 307
 308         if (nongit)
 309                 die(_("Not a git repository"));
 310         argc = setup_revisions(argc, argv, &rev, NULL);
 311         if (!rev.diffopt.output_format) {
 312                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 313                 diff_setup_done(&rev.diffopt);
 314         }
 315
 316         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 317
 318         setup_diff_pager(&rev.diffopt);
 319
 320         /*
 321          * Do we have --cached and not have a pending object, then
 322          * default to HEAD by hand.  Eek.
 323          */
 324         if (!rev.pending.nr) {
 325                 int i;
 326                 for (i = 1; i < argc; i++) {
 327                         const char *arg = argv[i];
 328                         if (!strcmp(arg, "--"))
 329                                 break;
 330                         else if (!strcmp(arg, "--cached") ||
 331                                  !strcmp(arg, "--staged")) {
 332                                 add_head_to_pending(&rev);
 333                                 if (!rev.pending.nr) {
 334                                         struct tree *tree;
 335                                         tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 336                                         add_pending_object(&rev, &tree->object, "HEAD");
 337                                 }
 338                                 break;
 339                         }
 340                 }
 341         }
 342
 343         for (i = 0; i < rev.pending.nr; i++) {
 344                 struct object_array_entry *entry = &rev.pending.objects[i];
 345                 struct object *obj = entry->item;
 346                 const char *name = entry->name;
 347                 int flags = (obj->flags & UNINTERESTING);
 348                 if (!obj->parsed)
 349                         obj = parse_object(obj->sha1);
 350                 obj = deref_tag(obj, NULL, 0);
 351                 if (!obj)
 352                         die(_("invalid object '%s' given."), name);
 353                 if (obj->type == OBJ_COMMIT)
 354                         obj = &((struct commit *)obj)->tree->object;
 355
 356                 if (obj->type == OBJ_TREE) {
 357                         obj->flags |= flags;
 358                         add_object_array(obj, name, &ent);
 359                 } else if (obj->type == OBJ_BLOB) {
 360                         if (2 <= blobs)
 361                                 die(_("more than two blobs given: '%s'"), name);
 362                         hashcpy(blob[blobs].sha1, obj->sha1);
 363                         blob[blobs].name = name;
 364                         blob[blobs].mode = entry->mode;
 365                         blobs++;
 366
 367                 } else {
 368                         die(_("unhandled object '%s' given."), name);
 369                 }
 370         }
 371         if (rev.prune_data.nr)
 372                 paths += rev.prune_data.nr;
 373
 374         /*
 375          * Now, do the arguments look reasonable?
 376          */
 377         if (!ent.nr) {
 378                 switch (blobs) {
 379                 case 0:
 380                         result = builtin_diff_files(&rev, argc, argv);
 381                         break;
 382                 case 1:
 383                         if (paths != 1)
 384                                 usage(builtin_diff_usage);
 385                         result = builtin_diff_b_f(&rev, argc, argv, blob);
 386                         break;
 387                 case 2:
 388                         if (paths)
 389                                 usage(builtin_diff_usage);
 390                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 391                         break;
 392                 default:
 393                         usage(builtin_diff_usage);
 394                 }
 395         }
 396         else if (blobs)
 397                 usage(builtin_diff_usage);
 398         else if (ent.nr == 1)
 399                 result = builtin_diff_index(&rev, argc, argv);
 400         else if (ent.nr == 2)
 401                 result = builtin_diff_tree(&rev, argc, argv,
 402                                            &ent.objects[0], &ent.objects[1]);
 403         else if (ent.objects[0].item->flags & UNINTERESTING) {
 404                 /*
 405                  * diff A...B where there is at least one merge base
 406                  * between A and B.  We have ent.objects[0] ==
 407                  * merge-base, ent.objects[ents-2] == A, and
 408                  * ent.objects[ents-1] == B.  Show diff between the
 409                  * base and B.  Note that we pick one merge base at
 410                  * random if there are more than one.
 411                  */
 412                 result = builtin_diff_tree(&rev, argc, argv,
 413                                            &ent.objects[0],
 414                                            &ent.objects[ent.nr-1]);
 415         } else
 416                 result = builtin_diff_combined(&rev, argc, argv,
 417                                                ent.objects, ent.nr);
 418         result = diff_result_code(&rev.diffopt, result);
 419         if (1 < rev.diffopt.skip_stat_unmatch)
 420                 refresh_index_quietly();
 421         return result;
 422 }