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