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 diff_cache(struct cache_entry **ac, int entries)
  91 {
  92         while (entries) {
  93                 struct cache_entry *ce = *ac;
  94                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  95
  96                 switch (ce_stage(ce)) {
  97                 case 0:
  98                         /* No stage 1 entry? That means it's a new file */
  99                         if (!same) {
 100                                 show_new_file(ce);
 101                                 break;
 102                         }
 103                         /* Show difference between old and new */
 104                         show_modified(ac[1], ce, 1);
 105                         break;
 106                 case 1:
 107                         /* No stage 3 (merge) entry? That means it's been deleted */
 108                         if (!same) {
 109                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 110                                 break;
 111                         }
 112                         /* We come here with ce pointing at stage 1
 113                          * (original tree) and ac[1] pointing at stage
 114                          * 3 (unmerged).  show-modified with
 115                          * report-mising set to false does not say the
 116                          * file is deleted but reports true if work
 117                          * tree does not have it, in which case we
 118                          * fall through to report the unmerged state.
 119                          * Otherwise, we show the differences between
 120                          * the original tree and the work tree.
 121                          */
 122                         if (!cached_only && !show_modified(ce, ac[1], 0))
 123                                 break;
 124                         /* fallthru */
 125                 case 3:
 126                         diff_unmerge(ce->name);
 127                         break;
 128
 129                 default:
 130                         die("impossible cache entry stage");
 131                 }
 132
 133                 /*
 134                  * Ignore all the different stages for this file,
 135                  * we've handled the relevant cases now.
 136                  */
 137                 do {
 138                         ac++;
 139                         entries--;
 140                 } while (entries && ce_same_name(ce, ac[0]));
 141         }
 142         return 0;
 143 }
 144
 145 /*
 146  * This turns all merge entries into "stage 3". That guarantees that
 147  * when we read in the new tree (into "stage 1"), we won't lose sight
 148  * of the fact that we had unmerged entries.
 149  */
 150 static void mark_merge_entries(void)
 151 {
 152         int i;
 153         for (i = 0; i < active_nr; i++) {
 154                 struct cache_entry *ce = active_cache[i];
 155                 if (!ce_stage(ce))
 156                         continue;
 157                 ce->ce_flags |= htons(CE_STAGEMASK);
 158         }
 159 }
 160
 161 static char *diff_cache_usage =
 162 "git-diff-cache [-m] [--cached] "
 163 "[<common diff options>] <tree-ish> [<path>...]"
 164 COMMON_DIFF_OPTIONS_HELP;
 165
 166 int main(int argc, const char **argv)
 167 {
 168         const char *tree_name = NULL;
 169         unsigned char sha1[20];
 170         const char **pathspec = NULL;
 171         void *tree;
 172         unsigned long size;
 173         int ret;
 174         int allow_options = 1;
 175         int i;
 176
 177         read_cache();
 178         for (i = 1; i < argc; i++) {
 179                 const char *arg = argv[i];
 180
 181                 if (!allow_options || *arg != '-') {
 182                         if (tree_name) {
 183                                 pathspec = argv + i;
 184                                 break;
 185                         }
 186                         tree_name = arg;
 187                         continue;
 188                 }
 189
 190                 if (!strcmp(arg, "--")) {
 191                         allow_options = 0;
 192                         continue;
 193                 }
 194                 if (!strcmp(arg, "-r")) {
 195                         /* We accept the -r flag just to look like git-diff-tree */
 196                         continue;
 197                 }
 198                 /* We accept the -u flag as a synonym for "-p" */
 199                 if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
 200                         diff_output_format = DIFF_FORMAT_PATCH;
 201                         continue;
 202                 }
 203                 if (!strncmp(arg, "-B", 2)) {
 204                         if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
 205                                 usage(diff_cache_usage);
 206                         continue;
 207                 }
 208                 if (!strncmp(arg, "-M", 2)) {
 209                         detect_rename = DIFF_DETECT_RENAME;
 210                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 211                                 usage(diff_cache_usage);
 212                         continue;
 213                 }
 214                 if (!strncmp(arg, "-C", 2)) {
 215                         detect_rename = DIFF_DETECT_COPY;
 216                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 217                                 usage(diff_cache_usage);
 218                         continue;
 219                 }
 220                 if (!strcmp(arg, "--find-copies-harder")) {
 221                         find_copies_harder = 1;
 222                         continue;
 223                 }
 224                 if (!strcmp(arg, "-z")) {
 225                         diff_output_format = DIFF_FORMAT_MACHINE;
 226                         continue;
 227                 }
 228                 if (!strcmp(arg, "--name-only")) {
 229                         diff_output_format = DIFF_FORMAT_NAME;
 230                         continue;
 231                 }
 232                 if (!strcmp(arg, "--name-only-z")) {
 233                         diff_output_format = DIFF_FORMAT_NAME_Z;
 234                         continue;
 235                 }
 236                 if (!strcmp(arg, "-R")) {
 237                         diff_setup_opt |= DIFF_SETUP_REVERSE;
 238                         continue;
 239                 }
 240                 if (!strncmp(arg, "-S", 2)) {
 241                         pickaxe = arg + 2;
 242                         continue;
 243                 }
 244                 if (!strncmp(arg, "--diff-filter=", 14)) {
 245                         diff_filter = arg + 14;
 246                         continue;
 247                 }
 248                 if (!strncmp(arg, "-O", 2)) {
 249                         orderfile = arg + 2;
 250                         continue;
 251                 }
 252                 if (!strcmp(arg, "--pickaxe-all")) {
 253                         pickaxe_opts = DIFF_PICKAXE_ALL;
 254                         continue;
 255                 }
 256                 if (!strcmp(arg, "-m")) {
 257                         match_nonexisting = 1;
 258                         continue;
 259                 }
 260                 if (!strcmp(arg, "--cached")) {
 261                         cached_only = 1;
 262                         continue;
 263                 }
 264                 usage(diff_cache_usage);
 265         }
 266
 267         if (find_copies_harder && detect_rename != DIFF_DETECT_COPY)
 268                 usage(diff_cache_usage);
 269
 270         if (!tree_name || get_sha1(tree_name, sha1))
 271                 usage(diff_cache_usage);
 272
 273         /* The rest is for paths restriction. */
 274         diff_setup(diff_setup_opt);
 275
 276         mark_merge_entries();
 277
 278         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 279         if (!tree)
 280                 die("bad tree object %s", tree_name);
 281         if (read_tree(tree, size, 1))
 282                 die("unable to read tree object %s", tree_name);
 283
 284         ret = diff_cache(active_cache, active_nr);
 285
 286         diffcore_std(pathspec ? : NULL,
 287                      detect_rename, diff_score_opt,
 288                      pickaxe, pickaxe_opts,
 289                      diff_break_opt,
 290                      orderfile, diff_filter);
 291         diff_flush(diff_output_format);
 292         return ret;
 293 }