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