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         oldmode = old->ce_mode;
 217         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 218             !revs->diffopt.find_copies_harder)
 219                 return 0;
 220
 221         mode = ntohl(mode);
 222         oldmode = ntohl(oldmode);
 223
 224         diff_change(&revs->diffopt, oldmode, mode,
 225                     old->sha1, sha1, old->name, NULL);
 226         return 0;
 227 }
 228
 229 static int diff_cache(struct rev_info *revs,
 230                       struct cache_entry **ac, int entries,
 231                       const char **pathspec,
 232                       int cached, int match_missing)
 233 {
 234         while (entries) {
 235                 struct cache_entry *ce = *ac;
 236                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 237
 238                 if (!ce_path_match(ce, pathspec))
 239                         goto skip_entry;
 240
 241                 switch (ce_stage(ce)) {
 242                 case 0:
 243                         /* No stage 1 entry? That means it's a new file */
 244                         if (!same) {
 245                                 show_new_file(revs, ce, cached, match_missing);
 246                                 break;
 247                         }
 248                         /* Show difference between old and new */
 249                         show_modified(revs,ac[1], ce, 1,
 250                                       cached, match_missing);
 251                         break;
 252                 case 1:
 253                         /* No stage 3 (merge) entry?
 254                          * That means it's been deleted.
 255                          */
 256                         if (!same) {
 257                                 diff_index_show_file(revs, "-", ce,
 258                                                      ce->sha1, ce->ce_mode);
 259                                 break;
 260                         }
 261                         /* We come here with ce pointing at stage 1
 262                          * (original tree) and ac[1] pointing at stage
 263                          * 3 (unmerged).  show-modified with
 264                          * report-missing set to false does not say the
 265                          * file is deleted but reports true if work
 266                          * tree does not have it, in which case we
 267                          * fall through to report the unmerged state.
 268                          * Otherwise, we show the differences between
 269                          * the original tree and the work tree.
 270                          */
 271                         if (!cached &&
 272                             !show_modified(revs, ce, ac[1], 0,
 273                                            cached, match_missing))
 274                                 break;
 275                         /* fallthru */
 276                 case 3:
 277                         diff_unmerge(&revs->diffopt, ce->name);
 278                         break;
 279
 280                 default:
 281                         die("impossible cache entry stage");
 282                 }
 283
 284 skip_entry:
 285                 /*
 286                  * Ignore all the different stages for this file,
 287                  * we've handled the relevant cases now.
 288                  */
 289                 do {
 290                         ac++;
 291                         entries--;
 292                 } while (entries && ce_same_name(ce, ac[0]));
 293         }
 294         return 0;
 295 }
 296
 297 /*
 298  * This turns all merge entries into "stage 3". That guarantees that
 299  * when we read in the new tree (into "stage 1"), we won't lose sight
 300  * of the fact that we had unmerged entries.
 301  */
 302 static void mark_merge_entries(void)
 303 {
 304         int i;
 305         for (i = 0; i < active_nr; i++) {
 306                 struct cache_entry *ce = active_cache[i];
 307                 if (!ce_stage(ce))
 308                         continue;
 309                 ce->ce_flags |= htons(CE_STAGEMASK);
 310         }
 311 }
 312
 313 int run_diff_index(struct rev_info *revs, int cached)
 314 {
 315         int ret;
 316         struct object *ent;
 317         struct tree *tree;
 318         const char *tree_name;
 319         int match_missing = 0;
 320
 321         /*
 322          * Backward compatibility wart - "diff-index -m" does
 323          * not mean "do not ignore merges", but totally different.
 324          */
 325         if (!revs->ignore_merges)
 326                 match_missing = 1;
 327
 328         if (read_cache() < 0) {
 329                 perror("read_cache");
 330                 return -1;
 331         }
 332         mark_merge_entries();
 333
 334         ent = revs->pending.objects[0].item;
 335         tree_name = revs->pending.objects[0].name;
 336         tree = parse_tree_indirect(ent->sha1);
 337         if (!tree)
 338                 return error("bad tree object %s", tree_name);
 339         if (read_tree(tree, 1, revs->prune_data))
 340                 return error("unable to read tree object %s", tree_name);
 341         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 342                          cached, match_missing);
 343         diffcore_std(&revs->diffopt);
 344         diff_flush(&revs->diffopt);
 345         return ret;
 346 }