diff-index.c

   1 #include "cache.h"
   2 #include "tree.h"
   3 #include "diff.h"
   4
   5 static int cached_only = 0;
   6 static int match_nonexisting = 0;
   7 static struct diff_options diff_options;
   8
   9 /* A file entry went away or appeared */
  10 static void show_file(const char *prefix,
  11                       struct cache_entry *ce,
  12                       unsigned char *sha1, unsigned int mode)
  13 {
  14         diff_addremove(&diff_options, prefix[0], ntohl(mode),
  15                        sha1, ce->name, NULL);
  16 }
  17
  18 static int get_stat_data(struct cache_entry *ce,
  19                          unsigned char ** sha1p, unsigned int *modep)
  20 {
  21         unsigned char *sha1 = ce->sha1;
  22         unsigned int mode = ce->ce_mode;
  23
  24         if (!cached_only) {
  25                 static unsigned char no_sha1[20];
  26                 int changed;
  27                 struct stat st;
  28                 if (lstat(ce->name, &st) < 0) {
  29                         if (errno == ENOENT && match_nonexisting) {
  30                                 *sha1p = sha1;
  31                                 *modep = mode;
  32                                 return 0;
  33                         }
  34                         return -1;
  35                 }
  36                 changed = ce_match_stat(ce, &st, 0);
  37                 if (changed) {
  38                         mode = create_ce_mode(st.st_mode);
  39                         if (!trust_executable_bit &&
  40                             S_ISREG(mode) && S_ISREG(ce->ce_mode) &&
  41                             ((mode ^ ce->ce_mode) == 0111))
  42                                 mode = ce->ce_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
  58          * the working copy.
  59          */
  60         if (get_stat_data(new, &sha1, &mode) < 0)
  61                 return;
  62
  63         show_file("+", new, sha1, mode);
  64 }
  65
  66 static int show_modified(struct cache_entry *old,
  67                          struct cache_entry *new,
  68                          int report_missing)
  69 {
  70         unsigned int mode, oldmode;
  71         unsigned char *sha1;
  72
  73         if (get_stat_data(new, &sha1, &mode) < 0) {
  74                 if (report_missing)
  75                         show_file("-", old, old->sha1, old->ce_mode);
  76                 return -1;
  77         }
  78
  79         oldmode = old->ce_mode;
  80         if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  81             !diff_options.find_copies_harder)
  82                 return 0;
  83
  84         mode = ntohl(mode);
  85         oldmode = ntohl(oldmode);
  86
  87         diff_change(&diff_options, oldmode, mode,
  88                     old->sha1, sha1, old->name, NULL);
  89         return 0;
  90 }
  91
  92 static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
  93 {
  94         while (entries) {
  95                 struct cache_entry *ce = *ac;
  96                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  97
  98                 if (!ce_path_match(ce, pathspec))
  99                         goto skip_entry;
 100
 101                 switch (ce_stage(ce)) {
 102                 case 0:
 103                         /* No stage 1 entry? That means it's a new file */
 104                         if (!same) {
 105                                 show_new_file(ce);
 106                                 break;
 107                         }
 108                         /* Show difference between old and new */
 109                         show_modified(ac[1], ce, 1);
 110                         break;
 111                 case 1:
 112                         /* No stage 3 (merge) entry? That means it's been deleted */
 113                         if (!same) {
 114                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 115                                 break;
 116                         }
 117                         /* We come here with ce pointing at stage 1
 118                          * (original tree) and ac[1] pointing at stage
 119                          * 3 (unmerged).  show-modified with
 120                          * report-missing set to false does not say the
 121                          * file is deleted but reports true if work
 122                          * tree does not have it, in which case we
 123                          * fall through to report the unmerged state.
 124                          * Otherwise, we show the differences between
 125                          * the original tree and the work tree.
 126                          */
 127                         if (!cached_only && !show_modified(ce, ac[1], 0))
 128                                 break;
 129                         /* fallthru */
 130                 case 3:
 131                         diff_unmerge(&diff_options, ce->name);
 132                         break;
 133
 134                 default:
 135                         die("impossible cache entry stage");
 136                 }
 137
 138 skip_entry:
 139                 /*
 140                  * Ignore all the different stages for this file,
 141                  * we've handled the relevant cases now.
 142                  */
 143                 do {
 144                         ac++;
 145                         entries--;
 146                 } while (entries && ce_same_name(ce, ac[0]));
 147         }
 148         return 0;
 149 }
 150
 151 /*
 152  * This turns all merge entries into "stage 3". That guarantees that
 153  * when we read in the new tree (into "stage 1"), we won't lose sight
 154  * of the fact that we had unmerged entries.
 155  */
 156 static void mark_merge_entries(void)
 157 {
 158         int i;
 159         for (i = 0; i < active_nr; i++) {
 160                 struct cache_entry *ce = active_cache[i];
 161                 if (!ce_stage(ce))
 162                         continue;
 163                 ce->ce_flags |= htons(CE_STAGEMASK);
 164         }
 165 }
 166
 167 static const char diff_cache_usage[] =
 168 "git-diff-index [-m] [--cached] "
 169 "[<common diff options>] <tree-ish> [<path>...]"
 170 COMMON_DIFF_OPTIONS_HELP;
 171
 172 int main(int argc, const char **argv)
 173 {
 174         const char *tree_name = NULL;
 175         unsigned char sha1[20];
 176         const char *prefix = setup_git_directory();
 177         const char **pathspec = NULL;
 178         struct tree *tree;
 179         int ret;
 180         int allow_options = 1;
 181         int i;
 182
 183         git_config(git_diff_config);
 184         diff_setup(&diff_options);
 185         for (i = 1; i < argc; i++) {
 186                 const char *arg = argv[i];
 187                 int diff_opt_cnt;
 188
 189                 if (!allow_options || *arg != '-') {
 190                         if (tree_name)
 191                                 break;
 192                         tree_name = arg;
 193                         continue;
 194                 }
 195
 196                 if (!strcmp(arg, "--")) {
 197                         allow_options = 0;
 198                         continue;
 199                 }
 200                 if (!strcmp(arg, "-r")) {
 201                         /* We accept the -r flag just to look like git-diff-tree */
 202                         continue;
 203                 }
 204                 if (!strcmp(arg, "--cc"))
 205                         /*
 206                          * I _think_ "diff-index --cached HEAD" with an
 207                          * unmerged index could show something else
 208                          * later, but pretend --cc is the same as -p for
 209                          * now.  "git diff" uses --cc by default.
 210                          */
 211                         argv[i] = arg = "-p";
 212                 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
 213                                               argc - i);
 214                 if (diff_opt_cnt < 0)
 215                         usage(diff_cache_usage);
 216                 else if (diff_opt_cnt) {
 217                         i += diff_opt_cnt - 1;
 218                         continue;
 219                 }
 220
 221                 if (!strcmp(arg, "-m")) {
 222                         match_nonexisting = 1;
 223                         continue;
 224                 }
 225                 if (!strcmp(arg, "--cached")) {
 226                         cached_only = 1;
 227                         continue;
 228                 }
 229                 usage(diff_cache_usage);
 230         }
 231
 232         pathspec = get_pathspec(prefix, argv + i);
 233
 234         if (diff_setup_done(&diff_options) < 0)
 235                 usage(diff_cache_usage);
 236
 237         if (!tree_name || get_sha1(tree_name, sha1))
 238                 usage(diff_cache_usage);
 239
 240         read_cache();
 241
 242         mark_merge_entries();
 243
 244         tree = parse_tree_indirect(sha1);
 245         if (!tree)
 246                 die("bad tree object %s", tree_name);
 247         if (read_tree(tree, 1, pathspec))
 248                 die("unable to read tree object %s", tree_name);
 249
 250         ret = diff_cache(active_cache, active_nr, pathspec);
 251
 252         diffcore_std(&diff_options);
 253         diff_flush(&diff_options);
 254         return ret;
 255 }