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