diff-cache.c

   1 #include "cache.h"
   2 #include "diff.h"
   3
   4 static int cached_only = 0;
   5 static int diff_output_format = DIFF_FORMAT_HUMAN;
   6 static int match_nonexisting = 0;
   7 static int detect_rename = 0;
   8 static int find_copies_harder = 0;
   9 static int diff_setup_opt = 0;
  10 static int diff_score_opt = 0;
  11 static const char *pickaxe = NULL;
  12 static int pickaxe_opts = 0;
  13 static int diff_break_opt = -1;
  14 static const char *orderfile = NULL;
  15 static const char *diff_filter = NULL;
  16
  17 /* A file entry went away or appeared */
  18 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  19 {
  20         diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  21 }
  22
  23 static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
  24 {
  25         unsigned char *sha1 = ce->sha1;
  26         unsigned int mode = ce->ce_mode;
  27
  28         if (!cached_only) {
  29                 static unsigned char no_sha1[20];
  30                 int changed;
  31                 struct stat st;
  32                 if (lstat(ce->name, &st) < 0) {
  33                         if (errno == ENOENT && match_nonexisting) {
  34                                 *sha1p = sha1;
  35                                 *modep = mode;
  36                                 return 0;
  37                         }
  38                         return -1;
  39                 }
  40                 changed = ce_match_stat(ce, &st);
  41                 if (changed) {
  42                         mode = create_ce_mode(st.st_mode);
  43                         sha1 = no_sha1;
  44                 }
  45         }
  46
  47         *sha1p = sha1;
  48         *modep = mode;
  49         return 0;
  50 }
  51
  52 static void show_new_file(struct cache_entry *new)
  53 {
  54         unsigned char *sha1;
  55         unsigned int mode;
  56
  57         /* New file in the index: it might actually be different in the working copy */
  58         if (get_stat_data(new, &sha1, &mode) < 0)
  59                 return;
  60
  61         show_file("+", new, sha1, mode);
  62 }
  63
  64 static int show_modified(struct cache_entry *old,
  65                          struct cache_entry *new,
  66                          int report_missing)
  67 {
  68         unsigned int mode, oldmode;
  69         unsigned char *sha1;
  70
  71         if (get_stat_data(new, &sha1, &mode) < 0) {
  72                 if (report_missing)
  73                         show_file("-", old, old->sha1, old->ce_mode);
  74                 return -1;
  75         }
  76
  77         oldmode = old->ce_mode;
  78         if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  79             !find_copies_harder)
  80                 return 0;
  81
  82         mode = ntohl(mode);
  83         oldmode = ntohl(oldmode);
  84
  85         diff_change(oldmode, mode,
  86                     old->sha1, sha1, old->name, NULL);
  87         return 0;
  88 }
  89
  90 static int ce_path_match(const struct cache_entry *ce, const char **pathspec)
  91 {
  92         const char *match, *name;
  93         int len;
  94
  95         if (!pathspec)
  96                 return 1;
  97
  98         len = ce_namelen(ce);
  99         name = ce->name;
 100         while ((match = *pathspec++) != NULL) {
 101                 int matchlen = strlen(match);
 102                 if (matchlen > len)
 103                         continue;
 104                 if (memcmp(name, match, matchlen))
 105                         continue;
 106                 if (name[matchlen] == '/' || !name[matchlen])
 107                         return 1;
 108         }
 109         return 0;
 110 }
 111
 112 static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
 113 {
 114         while (entries) {
 115                 struct cache_entry *ce = *ac;
 116                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 117
 118                 if (!ce_path_match(ce, pathspec))
 119                         goto skip_entry;
 120
 121                 switch (ce_stage(ce)) {
 122                 case 0:
 123                         /* No stage 1 entry? That means it's a new file */
 124                         if (!same) {
 125                                 show_new_file(ce);
 126                                 break;
 127                         }
 128                         /* Show difference between old and new */
 129                         show_modified(ac[1], ce, 1);
 130                         break;
 131                 case 1:
 132                         /* No stage 3 (merge) entry? That means it's been deleted */
 133                         if (!same) {
 134                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 135                                 break;
 136                         }
 137                         /* We come here with ce pointing at stage 1
 138                          * (original tree) and ac[1] pointing at stage
 139                          * 3 (unmerged).  show-modified with
 140                          * report-mising set to false does not say the
 141                          * file is deleted but reports true if work
 142                          * tree does not have it, in which case we
 143                          * fall through to report the unmerged state.
 144                          * Otherwise, we show the differences between
 145                          * the original tree and the work tree.
 146                          */
 147                         if (!cached_only && !show_modified(ce, ac[1], 0))
 148                                 break;
 149                         /* fallthru */
 150                 case 3:
 151                         diff_unmerge(ce->name);
 152                         break;
 153
 154                 default:
 155                         die("impossible cache entry stage");
 156                 }
 157
 158 skip_entry:
 159                 /*
 160                  * Ignore all the different stages for this file,
 161                  * we've handled the relevant cases now.
 162                  */
 163                 do {
 164                         ac++;
 165                         entries--;
 166                 } while (entries && ce_same_name(ce, ac[0]));
 167         }
 168         return 0;
 169 }
 170
 171 /*
 172  * This turns all merge entries into "stage 3". That guarantees that
 173  * when we read in the new tree (into "stage 1"), we won't lose sight
 174  * of the fact that we had unmerged entries.
 175  */
 176 static void mark_merge_entries(void)
 177 {
 178         int i;
 179         for (i = 0; i < active_nr; i++) {
 180                 struct cache_entry *ce = active_cache[i];
 181                 if (!ce_stage(ce))
 182                         continue;
 183                 ce->ce_flags |= htons(CE_STAGEMASK);
 184         }
 185 }
 186
 187 static char *diff_cache_usage =
 188 "git-diff-cache [-m] [--cached] "
 189 "[<common diff options>] <tree-ish> [<path>...]"
 190 COMMON_DIFF_OPTIONS_HELP;
 191
 192 int main(int argc, const char **argv)
 193 {
 194         const char *tree_name = NULL;
 195         unsigned char sha1[20];
 196         const char **pathspec = NULL;
 197         void *tree;
 198         unsigned long size;
 199         int ret;
 200         int allow_options = 1;
 201         int i;
 202
 203         read_cache();
 204         for (i = 1; i < argc; i++) {
 205                 const char *arg = argv[i];
 206
 207                 if (!allow_options || *arg != '-') {
 208                         if (tree_name) {
 209                                 pathspec = argv + i;
 210                                 break;
 211                         }
 212                         tree_name = arg;
 213                         continue;
 214                 }
 215
 216                 if (!strcmp(arg, "--")) {
 217                         allow_options = 0;
 218                         continue;
 219                 }
 220                 if (!strcmp(arg, "-r")) {
 221                         /* We accept the -r flag just to look like git-diff-tree */
 222                         continue;
 223                 }
 224                 /* We accept the -u flag as a synonym for "-p" */
 225                 if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
 226                         diff_output_format = DIFF_FORMAT_PATCH;
 227                         continue;
 228                 }
 229                 if (!strncmp(arg, "-B", 2)) {
 230                         if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
 231                                 usage(diff_cache_usage);
 232                         continue;
 233                 }
 234                 if (!strncmp(arg, "-M", 2)) {
 235                         detect_rename = DIFF_DETECT_RENAME;
 236                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 237                                 usage(diff_cache_usage);
 238                         continue;
 239                 }
 240                 if (!strncmp(arg, "-C", 2)) {
 241                         detect_rename = DIFF_DETECT_COPY;
 242                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 243                                 usage(diff_cache_usage);
 244                         continue;
 245                 }
 246                 if (!strcmp(arg, "--find-copies-harder")) {
 247                         find_copies_harder = 1;
 248                         continue;
 249                 }
 250                 if (!strcmp(arg, "-z")) {
 251                         diff_output_format = DIFF_FORMAT_MACHINE;
 252                         continue;
 253                 }
 254                 if (!strcmp(arg, "--name-only")) {
 255                         diff_output_format = DIFF_FORMAT_NAME;
 256                         continue;
 257                 }
 258                 if (!strcmp(arg, "--name-only-z")) {
 259                         diff_output_format = DIFF_FORMAT_NAME_Z;
 260                         continue;
 261                 }
 262                 if (!strcmp(arg, "-R")) {
 263                         diff_setup_opt |= DIFF_SETUP_REVERSE;
 264                         continue;
 265                 }
 266                 if (!strncmp(arg, "-S", 2)) {
 267                         pickaxe = arg + 2;
 268                         continue;
 269                 }
 270                 if (!strncmp(arg, "--diff-filter=", 14)) {
 271                         diff_filter = arg + 14;
 272                         continue;
 273                 }
 274                 if (!strncmp(arg, "-O", 2)) {
 275                         orderfile = arg + 2;
 276                         continue;
 277                 }
 278                 if (!strcmp(arg, "--pickaxe-all")) {
 279                         pickaxe_opts = DIFF_PICKAXE_ALL;
 280                         continue;
 281                 }
 282                 if (!strcmp(arg, "-m")) {
 283                         match_nonexisting = 1;
 284                         continue;
 285                 }
 286                 if (!strcmp(arg, "--cached")) {
 287                         cached_only = 1;
 288                         continue;
 289                 }
 290                 usage(diff_cache_usage);
 291         }
 292
 293         if (find_copies_harder && detect_rename != DIFF_DETECT_COPY)
 294                 usage(diff_cache_usage);
 295
 296         if (!tree_name || get_sha1(tree_name, sha1))
 297                 usage(diff_cache_usage);
 298
 299         /* The rest is for paths restriction. */
 300         diff_setup(diff_setup_opt);
 301
 302         mark_merge_entries();
 303
 304         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 305         if (!tree)
 306                 die("bad tree object %s", tree_name);
 307         if (read_tree(tree, size, 1, pathspec))
 308                 die("unable to read tree object %s", tree_name);
 309
 310         ret = diff_cache(active_cache, active_nr, pathspec);
 311
 312         diffcore_std(pathspec,
 313                      detect_rename, diff_score_opt,
 314                      pickaxe, pickaxe_opts,
 315                      diff_break_opt,
 316                      orderfile, diff_filter);
 317         diff_flush(diff_output_format);
 318         return ret;
 319 }