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                         memset(dpath->sha1, 0, 20);
  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                                         memcpy(dpath->parent[stage-2].sha1,
  70                                                nce->sha1, 20);
  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);
 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         oldmode = old->ce_mode;
 218         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 219             !revs->diffopt.find_copies_harder)
 220                 return 0;
 221
 222         mode = ntohl(mode);
 223         oldmode = ntohl(oldmode);
 224
 225         diff_change(&revs->diffopt, oldmode, mode,
 226                     old->sha1, sha1, old->name, NULL);
 227         return 0;
 228 }
 229
 230 static int diff_cache(struct rev_info *revs,
 231                       struct cache_entry **ac, int entries,
 232                       const char **pathspec,
 233                       int cached, int match_missing)
 234 {
 235         while (entries) {
 236                 struct cache_entry *ce = *ac;
 237                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 238
 239                 if (!ce_path_match(ce, pathspec))
 240                         goto skip_entry;
 241
 242                 switch (ce_stage(ce)) {
 243                 case 0:
 244                         /* No stage 1 entry? That means it's a new file */
 245                         if (!same) {
 246                                 show_new_file(revs, ce, cached, match_missing);
 247                                 break;
 248                         }
 249                         /* Show difference between old and new */
 250                         show_modified(revs,ac[1], ce, 1,
 251                                       cached, match_missing);
 252                         break;
 253                 case 1:
 254                         /* No stage 3 (merge) entry?
 255                          * That means it's been deleted.
 256                          */
 257                         if (!same) {
 258                                 diff_index_show_file(revs, "-", ce,
 259                                                      ce->sha1, ce->ce_mode);
 260                                 break;
 261                         }
 262                         /* We come here with ce pointing at stage 1
 263                          * (original tree) and ac[1] pointing at stage
 264                          * 3 (unmerged).  show-modified with
 265                          * report-missing set to false does not say the
 266                          * file is deleted but reports true if work
 267                          * tree does not have it, in which case we
 268                          * fall through to report the unmerged state.
 269                          * Otherwise, we show the differences between
 270                          * the original tree and the work tree.
 271                          */
 272                         if (!cached &&
 273                             !show_modified(revs, ce, ac[1], 0,
 274                                            cached, match_missing))
 275                                 break;
 276                         /* fallthru */
 277                 case 3:
 278                         diff_unmerge(&revs->diffopt, ce->name);
 279                         break;
 280
 281                 default:
 282                         die("impossible cache entry stage");
 283                 }
 284
 285 skip_entry:
 286                 /*
 287                  * Ignore all the different stages for this file,
 288                  * we've handled the relevant cases now.
 289                  */
 290                 do {
 291                         ac++;
 292                         entries--;
 293                 } while (entries && ce_same_name(ce, ac[0]));
 294         }
 295         return 0;
 296 }
 297
 298 /*
 299  * This turns all merge entries into "stage 3". That guarantees that
 300  * when we read in the new tree (into "stage 1"), we won't lose sight
 301  * of the fact that we had unmerged entries.
 302  */
 303 static void mark_merge_entries(void)
 304 {
 305         int i;
 306         for (i = 0; i < active_nr; i++) {
 307                 struct cache_entry *ce = active_cache[i];
 308                 if (!ce_stage(ce))
 309                         continue;
 310                 ce->ce_flags |= htons(CE_STAGEMASK);
 311         }
 312 }
 313
 314 int run_diff_index(struct rev_info *revs, int cached)
 315 {
 316         int ret;
 317         struct object *ent;
 318         struct tree *tree;
 319         const char *tree_name;
 320         int match_missing = 0;
 321
 322         /*
 323          * Backward compatibility wart - "diff-index -m" does
 324          * not mean "do not ignore merges", but totally different.
 325          */
 326         if (!revs->ignore_merges)
 327                 match_missing = 1;
 328
 329         if (read_cache() < 0) {
 330                 perror("read_cache");
 331                 return -1;
 332         }
 333         mark_merge_entries();
 334
 335         ent = revs->pending.objects[0].item;
 336         tree_name = revs->pending.objects[0].name;
 337         tree = parse_tree_indirect(ent->sha1);
 338         if (!tree)
 339                 return error("bad tree object %s", tree_name);
 340         if (read_tree(tree, 1, revs->prune_data))
 341                 return error("unable to read tree object %s", tree_name);
 342         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 343                          cached, match_missing);
 344         diffcore_std(&revs->diffopt);
 345         diff_flush(&revs->diffopt);
 346         return ret;
 347 }