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