diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "quote.h"
   6 #include "commit.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "revision.h"
  10 #include "cache-tree.h"
  11
  12 /*
  13  * diff-files
  14  */
  15
  16 int run_diff_files(struct rev_info *revs, int silent_on_removed)
  17 {
  18         int entries, i;
  19         int diff_unmerged_stage = revs->max_count;
  20
  21         if (diff_unmerged_stage < 0)
  22                 diff_unmerged_stage = 2;
  23         entries = read_cache();
  24         if (entries < 0) {
  25                 perror("read_cache");
  26                 return -1;
  27         }
  28         for (i = 0; i < entries; i++) {
  29                 struct stat st;
  30                 unsigned int oldmode, newmode;
  31                 struct cache_entry *ce = active_cache[i];
  32                 int changed;
  33
  34                 if (!ce_path_match(ce, revs->prune_data))
  35                         continue;
  36
  37                 if (ce_stage(ce)) {
  38                         struct combine_diff_path *dpath;
  39                         int num_compare_stages = 0;
  40                         size_t path_len;
  41
  42                         path_len = ce_namelen(ce);
  43
  44                         dpath = xmalloc(combine_diff_path_size(5, path_len));
  45                         dpath->path = (char *) &(dpath->parent[5]);
  46
  47                         dpath->next = NULL;
  48                         dpath->len = path_len;
  49                         memcpy(dpath->path, ce->name, path_len);
  50                         dpath->path[path_len] = '\0';
  51                         hashclr(dpath->sha1);
  52                         memset(&(dpath->parent[0]), 0,
  53                                sizeof(struct combine_diff_parent)*5);
  54
  55                         if (lstat(ce->name, &st) < 0) {
  56                                 if (errno != ENOENT && errno != ENOTDIR) {
  57                                         perror(ce->name);
  58                                         continue;
  59                                 }
  60                                 if (silent_on_removed)
  61                                         continue;
  62                         }
  63                         else
  64                                 dpath->mode = canon_mode(st.st_mode);
  65
  66                         while (i < entries) {
  67                                 struct cache_entry *nce = active_cache[i];
  68                                 int stage;
  69
  70                                 if (strcmp(ce->name, nce->name))
  71                                         break;
  72
  73                                 /* Stage #2 (ours) is the first parent,
  74                                  * stage #3 (theirs) is the second.
  75                                  */
  76                                 stage = ce_stage(nce);
  77                                 if (2 <= stage) {
  78                                         int mode = ntohl(nce->ce_mode);
  79                                         num_compare_stages++;
  80                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
  81                                         dpath->parent[stage-2].mode =
  82                                                 canon_mode(mode);
  83                                         dpath->parent[stage-2].status =
  84                                                 DIFF_STATUS_MODIFIED;
  85                                 }
  86
  87                                 /* diff against the proper unmerged stage */
  88                                 if (stage == diff_unmerged_stage)
  89                                         ce = nce;
  90                                 i++;
  91                         }
  92                         /*
  93                          * Compensate for loop update
  94                          */
  95                         i--;
  96
  97                         if (revs->combine_merges && num_compare_stages == 2) {
  98                                 show_combined_diff(dpath, 2,
  99                                                    revs->dense_combined_merges,
 100                                                    revs);
 101                                 free(dpath);
 102                                 continue;
 103                         }
 104                         free(dpath);
 105                         dpath = NULL;
 106
 107                         /*
 108                          * Show the diff for the 'ce' if we found the one
 109                          * from the desired stage.
 110                          */
 111                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 112                         if (ce_stage(ce) != diff_unmerged_stage)
 113                                 continue;
 114                 }
 115
 116                 if (lstat(ce->name, &st) < 0) {
 117                         if (errno != ENOENT && errno != ENOTDIR) {
 118                                 perror(ce->name);
 119                                 continue;
 120                         }
 121                         if (silent_on_removed)
 122                                 continue;
 123                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 124                                        ce->sha1, ce->name, NULL);
 125                         continue;
 126                 }
 127                 changed = ce_match_stat(ce, &st, 0);
 128                 if (!changed && !revs->diffopt.find_copies_harder)
 129                         continue;
 130                 oldmode = ntohl(ce->ce_mode);
 131
 132                 newmode = canon_mode(st.st_mode);
 133                 if (!trust_executable_bit &&
 134                     S_ISREG(newmode) && S_ISREG(oldmode) &&
 135                     ((newmode ^ oldmode) == 0111))
 136                         newmode = oldmode;
 137                 diff_change(&revs->diffopt, oldmode, newmode,
 138                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 139                             ce->name, NULL);
 140
 141         }
 142         diffcore_std(&revs->diffopt);
 143         diff_flush(&revs->diffopt);
 144         return 0;
 145 }
 146
 147 /*
 148  * diff-index
 149  */
 150
 151 /* A file entry went away or appeared */
 152 static void diff_index_show_file(struct rev_info *revs,
 153                                  const char *prefix,
 154                                  struct cache_entry *ce,
 155                                  unsigned char *sha1, unsigned int mode)
 156 {
 157         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 158                        sha1, ce->name, NULL);
 159 }
 160
 161 static int get_stat_data(struct cache_entry *ce,
 162                          unsigned char **sha1p,
 163                          unsigned int *modep,
 164                          int cached, int match_missing)
 165 {
 166         unsigned char *sha1 = ce->sha1;
 167         unsigned int mode = ce->ce_mode;
 168
 169         if (!cached) {
 170                 static unsigned char no_sha1[20];
 171                 int changed;
 172                 struct stat st;
 173                 if (lstat(ce->name, &st) < 0) {
 174                         if (errno == ENOENT && match_missing) {
 175                                 *sha1p = sha1;
 176                                 *modep = mode;
 177                                 return 0;
 178                         }
 179                         return -1;
 180                 }
 181                 changed = ce_match_stat(ce, &st, 0);
 182                 if (changed) {
 183                         mode = ce_mode_from_stat(ce, st.st_mode);
 184                         sha1 = no_sha1;
 185                 }
 186         }
 187
 188         *sha1p = sha1;
 189         *modep = mode;
 190         return 0;
 191 }
 192
 193 static void show_new_file(struct rev_info *revs,
 194                           struct cache_entry *new,
 195                           int cached, int match_missing)
 196 {
 197         unsigned char *sha1;
 198         unsigned int mode;
 199
 200         /* New file in the index: it might actually be different in
 201          * the working copy.
 202          */
 203         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 204                 return;
 205
 206         diff_index_show_file(revs, "+", new, sha1, mode);
 207 }
 208
 209 static int show_modified(struct rev_info *revs,
 210                          struct cache_entry *old,
 211                          struct cache_entry *new,
 212                          int report_missing,
 213                          int cached, int match_missing)
 214 {
 215         unsigned int mode, oldmode;
 216         unsigned char *sha1;
 217
 218         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 219                 if (report_missing)
 220                         diff_index_show_file(revs, "-", old,
 221                                              old->sha1, old->ce_mode);
 222                 return -1;
 223         }
 224
 225         if (revs->combine_merges && !cached &&
 226             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 227                 struct combine_diff_path *p;
 228                 int pathlen = ce_namelen(new);
 229
 230                 p = xmalloc(combine_diff_path_size(2, pathlen));
 231                 p->path = (char *) &p->parent[2];
 232                 p->next = NULL;
 233                 p->len = pathlen;
 234                 memcpy(p->path, new->name, pathlen);
 235                 p->path[pathlen] = 0;
 236                 p->mode = ntohl(mode);
 237                 hashclr(p->sha1);
 238                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 239                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 240                 p->parent[0].mode = ntohl(new->ce_mode);
 241                 hashcpy(p->parent[0].sha1, new->sha1);
 242                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 243                 p->parent[1].mode = ntohl(old->ce_mode);
 244                 hashcpy(p->parent[1].sha1, old->sha1);
 245                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 246                 free(p);
 247                 return 0;
 248         }
 249
 250         oldmode = old->ce_mode;
 251         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 252             !revs->diffopt.find_copies_harder)
 253                 return 0;
 254
 255         mode = ntohl(mode);
 256         oldmode = ntohl(oldmode);
 257
 258         diff_change(&revs->diffopt, oldmode, mode,
 259                     old->sha1, sha1, old->name, NULL);
 260         return 0;
 261 }
 262
 263 static int diff_cache(struct rev_info *revs,
 264                       struct cache_entry **ac, int entries,
 265                       const char **pathspec,
 266                       int cached, int match_missing)
 267 {
 268         while (entries) {
 269                 struct cache_entry *ce = *ac;
 270                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 271
 272                 if (!ce_path_match(ce, pathspec))
 273                         goto skip_entry;
 274
 275                 switch (ce_stage(ce)) {
 276                 case 0:
 277                         /* No stage 1 entry? That means it's a new file */
 278                         if (!same) {
 279                                 show_new_file(revs, ce, cached, match_missing);
 280                                 break;
 281                         }
 282                         /* Show difference between old and new */
 283                         show_modified(revs, ac[1], ce, 1,
 284                                       cached, match_missing);
 285                         break;
 286                 case 1:
 287                         /* No stage 3 (merge) entry?
 288                          * That means it's been deleted.
 289                          */
 290                         if (!same) {
 291                                 diff_index_show_file(revs, "-", ce,
 292                                                      ce->sha1, ce->ce_mode);
 293                                 break;
 294                         }
 295                         /* We come here with ce pointing at stage 1
 296                          * (original tree) and ac[1] pointing at stage
 297                          * 3 (unmerged).  show-modified with
 298                          * report-missing set to false does not say the
 299                          * file is deleted but reports true if work
 300                          * tree does not have it, in which case we
 301                          * fall through to report the unmerged state.
 302                          * Otherwise, we show the differences between
 303                          * the original tree and the work tree.
 304                          */
 305                         if (!cached &&
 306                             !show_modified(revs, ce, ac[1], 0,
 307                                            cached, match_missing))
 308                                 break;
 309                         diff_unmerge(&revs->diffopt, ce->name,
 310                                      ntohl(ce->ce_mode), ce->sha1);
 311                         break;
 312                 case 3:
 313                         diff_unmerge(&revs->diffopt, ce->name,
 314                                      0, null_sha1);
 315                         break;
 316
 317                 default:
 318                         die("impossible cache entry stage");
 319                 }
 320
 321 skip_entry:
 322                 /*
 323                  * Ignore all the different stages for this file,
 324                  * we've handled the relevant cases now.
 325                  */
 326                 do {
 327                         ac++;
 328                         entries--;
 329                 } while (entries && ce_same_name(ce, ac[0]));
 330         }
 331         return 0;
 332 }
 333
 334 /*
 335  * This turns all merge entries into "stage 3". That guarantees that
 336  * when we read in the new tree (into "stage 1"), we won't lose sight
 337  * of the fact that we had unmerged entries.
 338  */
 339 static void mark_merge_entries(void)
 340 {
 341         int i;
 342         for (i = 0; i < active_nr; i++) {
 343                 struct cache_entry *ce = active_cache[i];
 344                 if (!ce_stage(ce))
 345                         continue;
 346                 ce->ce_flags |= htons(CE_STAGEMASK);
 347         }
 348 }
 349
 350 int run_diff_index(struct rev_info *revs, int cached)
 351 {
 352         int ret;
 353         struct object *ent;
 354         struct tree *tree;
 355         const char *tree_name;
 356         int match_missing = 0;
 357
 358         /*
 359          * Backward compatibility wart - "diff-index -m" does
 360          * not mean "do not ignore merges", but totally different.
 361          */
 362         if (!revs->ignore_merges)
 363                 match_missing = 1;
 364
 365         if (read_cache() < 0) {
 366                 perror("read_cache");
 367                 return -1;
 368         }
 369         mark_merge_entries();
 370
 371         ent = revs->pending.objects[0].item;
 372         tree_name = revs->pending.objects[0].name;
 373         tree = parse_tree_indirect(ent->sha1);
 374         if (!tree)
 375                 return error("bad tree object %s", tree_name);
 376         if (read_tree(tree, 1, revs->prune_data))
 377                 return error("unable to read tree object %s", tree_name);
 378         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 379                          cached, match_missing);
 380         diffcore_std(&revs->diffopt);
 381         diff_flush(&revs->diffopt);
 382         return ret;
 383 }
 384
 385 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 386 {
 387         struct tree *tree;
 388         struct rev_info revs;
 389         int i;
 390         struct cache_entry **dst;
 391         struct cache_entry *last = NULL;
 392
 393         /*
 394          * This is used by git-blame to run diff-cache internally;
 395          * it potentially needs to repeatedly run this, so we will
 396          * start by removing the higher order entries the last round
 397          * left behind.
 398          */
 399         dst = active_cache;
 400         for (i = 0; i < active_nr; i++) {
 401                 struct cache_entry *ce = active_cache[i];
 402                 if (ce_stage(ce)) {
 403                         if (last && !strcmp(ce->name, last->name))
 404                                 continue;
 405                         cache_tree_invalidate_path(active_cache_tree,
 406                                                    ce->name);
 407                         last = ce;
 408                         ce->ce_mode = 0;
 409                         ce->ce_flags &= ~htons(CE_STAGEMASK);
 410                 }
 411                 *dst++ = ce;
 412         }
 413         active_nr = dst - active_cache;
 414
 415         init_revisions(&revs, NULL);
 416         revs.prune_data = opt->paths;
 417         tree = parse_tree_indirect(tree_sha1);
 418         if (!tree)
 419                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 420         if (read_tree(tree, 1, opt->paths))
 421                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 422         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 423                           1, 0);
 424 }