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 = create_ce_mode(st.st_mode);
 174                         if (!trust_executable_bit && S_ISREG(st.st_mode))
 175                                 mode = ce->ce_mode;
 176                         sha1 = no_sha1;
 177                 }
 178         }
 179
 180         *sha1p = sha1;
 181         *modep = mode;
 182         return 0;
 183 }
 184
 185 static void show_new_file(struct rev_info *revs,
 186                           struct cache_entry *new,
 187                           int cached, int match_missing)
 188 {
 189         unsigned char *sha1;
 190         unsigned int mode;
 191
 192         /* New file in the index: it might actually be different in
 193          * the working copy.
 194          */
 195         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 196                 return;
 197
 198         diff_index_show_file(revs, "+", new, sha1, mode);
 199 }
 200
 201 static int show_modified(struct rev_info *revs,
 202                          struct cache_entry *old,
 203                          struct cache_entry *new,
 204                          int report_missing,
 205                          int cached, int match_missing)
 206 {
 207         unsigned int mode, oldmode;
 208         unsigned char *sha1;
 209
 210         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 211                 if (report_missing)
 212                         diff_index_show_file(revs, "-", old,
 213                                              old->sha1, old->ce_mode);
 214                 return -1;
 215         }
 216
 217         if (revs->combine_merges && !cached &&
 218             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 219                 struct combine_diff_path *p;
 220                 int pathlen = ce_namelen(new);
 221
 222                 p = xmalloc(combine_diff_path_size(2, pathlen));
 223                 p->path = (char *) &p->parent[2];
 224                 p->next = NULL;
 225                 p->len = pathlen;
 226                 memcpy(p->path, new->name, pathlen);
 227                 p->path[pathlen] = 0;
 228                 p->mode = ntohl(mode);
 229                 hashclr(p->sha1);
 230                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 231                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 232                 p->parent[0].mode = ntohl(new->ce_mode);
 233                 hashcpy(p->parent[0].sha1, new->sha1);
 234                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 235                 p->parent[1].mode = ntohl(old->ce_mode);
 236                 hashcpy(p->parent[1].sha1, old->sha1);
 237                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 238                 free(p);
 239                 return 0;
 240         }
 241
 242         oldmode = old->ce_mode;
 243         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 244             !revs->diffopt.find_copies_harder)
 245                 return 0;
 246
 247         mode = ntohl(mode);
 248         oldmode = ntohl(oldmode);
 249
 250         diff_change(&revs->diffopt, oldmode, mode,
 251                     old->sha1, sha1, old->name, NULL);
 252         return 0;
 253 }
 254
 255 static int diff_cache(struct rev_info *revs,
 256                       struct cache_entry **ac, int entries,
 257                       const char **pathspec,
 258                       int cached, int match_missing)
 259 {
 260         while (entries) {
 261                 struct cache_entry *ce = *ac;
 262                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 263
 264                 if (!ce_path_match(ce, pathspec))
 265                         goto skip_entry;
 266
 267                 switch (ce_stage(ce)) {
 268                 case 0:
 269                         /* No stage 1 entry? That means it's a new file */
 270                         if (!same) {
 271                                 show_new_file(revs, ce, cached, match_missing);
 272                                 break;
 273                         }
 274                         /* Show difference between old and new */
 275                         show_modified(revs, ac[1], ce, 1,
 276                                       cached, match_missing);
 277                         break;
 278                 case 1:
 279                         /* No stage 3 (merge) entry?
 280                          * That means it's been deleted.
 281                          */
 282                         if (!same) {
 283                                 diff_index_show_file(revs, "-", ce,
 284                                                      ce->sha1, ce->ce_mode);
 285                                 break;
 286                         }
 287                         /* We come here with ce pointing at stage 1
 288                          * (original tree) and ac[1] pointing at stage
 289                          * 3 (unmerged).  show-modified with
 290                          * report-missing set to false does not say the
 291                          * file is deleted but reports true if work
 292                          * tree does not have it, in which case we
 293                          * fall through to report the unmerged state.
 294                          * Otherwise, we show the differences between
 295                          * the original tree and the work tree.
 296                          */
 297                         if (!cached &&
 298                             !show_modified(revs, ce, ac[1], 0,
 299                                            cached, match_missing))
 300                                 break;
 301                         diff_unmerge(&revs->diffopt, ce->name,
 302                                      ntohl(ce->ce_mode), ce->sha1);
 303                         break;
 304                 case 3:
 305                         diff_unmerge(&revs->diffopt, ce->name,
 306                                      0, null_sha1);
 307                         break;
 308
 309                 default:
 310                         die("impossible cache entry stage");
 311                 }
 312
 313 skip_entry:
 314                 /*
 315                  * Ignore all the different stages for this file,
 316                  * we've handled the relevant cases now.
 317                  */
 318                 do {
 319                         ac++;
 320                         entries--;
 321                 } while (entries && ce_same_name(ce, ac[0]));
 322         }
 323         return 0;
 324 }
 325
 326 /*
 327  * This turns all merge entries into "stage 3". That guarantees that
 328  * when we read in the new tree (into "stage 1"), we won't lose sight
 329  * of the fact that we had unmerged entries.
 330  */
 331 static void mark_merge_entries(void)
 332 {
 333         int i;
 334         for (i = 0; i < active_nr; i++) {
 335                 struct cache_entry *ce = active_cache[i];
 336                 if (!ce_stage(ce))
 337                         continue;
 338                 ce->ce_flags |= htons(CE_STAGEMASK);
 339         }
 340 }
 341
 342 int run_diff_index(struct rev_info *revs, int cached)
 343 {
 344         int ret;
 345         struct object *ent;
 346         struct tree *tree;
 347         const char *tree_name;
 348         int match_missing = 0;
 349
 350         /*
 351          * Backward compatibility wart - "diff-index -m" does
 352          * not mean "do not ignore merges", but totally different.
 353          */
 354         if (!revs->ignore_merges)
 355                 match_missing = 1;
 356
 357         if (read_cache() < 0) {
 358                 perror("read_cache");
 359                 return -1;
 360         }
 361         mark_merge_entries();
 362
 363         ent = revs->pending.objects[0].item;
 364         tree_name = revs->pending.objects[0].name;
 365         tree = parse_tree_indirect(ent->sha1);
 366         if (!tree)
 367                 return error("bad tree object %s", tree_name);
 368         if (read_tree(tree, 1, revs->prune_data))
 369                 return error("unable to read tree object %s", tree_name);
 370         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 371                          cached, match_missing);
 372         diffcore_std(&revs->diffopt);
 373         diff_flush(&revs->diffopt);
 374         return ret;
 375 }
 376
 377 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 378 {
 379         struct tree *tree;
 380         struct rev_info revs;
 381         int i;
 382         struct cache_entry **dst;
 383         struct cache_entry *last = NULL;
 384
 385         /*
 386          * This is used by git-blame to run diff-cache internally;
 387          * it potentially needs to repeatedly run this, so we will
 388          * start by removing the higher order entries the last round
 389          * left behind.
 390          */
 391         dst = active_cache;
 392         for (i = 0; i < active_nr; i++) {
 393                 struct cache_entry *ce = active_cache[i];
 394                 if (ce_stage(ce)) {
 395                         if (last && !strcmp(ce->name, last->name))
 396                                 continue;
 397                         cache_tree_invalidate_path(active_cache_tree,
 398                                                    ce->name);
 399                         last = ce;
 400                         ce->ce_mode = 0;
 401                         ce->ce_flags &= ~htons(CE_STAGEMASK);
 402                 }
 403                 *dst++ = ce;
 404         }
 405         active_nr = dst - active_cache;
 406
 407         init_revisions(&revs, NULL);
 408         revs.prune_data = opt->paths;
 409         tree = parse_tree_indirect(tree_sha1);
 410         if (!tree)
 411                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 412         if (read_tree(tree, 1, opt->paths))
 413                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 414         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 415                           1, 0);
 416 }