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