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 && S_ISREG(st.st_mode))
  40                                 mode = ce->ce_mode;
  41                         sha1 = no_sha1;
  42                 }
  43         }
  44
  45         *sha1p = sha1;
  46         *modep = mode;
  47         return 0;
  48 }
  49
  50 static void show_new_file(struct cache_entry *new)
  51 {
  52         unsigned char *sha1;
  53         unsigned int mode;
  54
  55         /* New file in the index: it might actually be different in
  56          * the working copy.
  57          */
  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             !diff_options.find_copies_harder)
  80                 return 0;
  81
  82         mode = ntohl(mode);
  83         oldmode = ntohl(oldmode);
  84
  85         diff_change(&diff_options, 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, const char **pathspec)
  91 {
  92         while (entries) {
  93                 struct cache_entry *ce = *ac;
  94                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  95
  96                 if (!ce_path_match(ce, pathspec))
  97                         goto skip_entry;
  98
  99                 switch (ce_stage(ce)) {
 100                 case 0:
 101                         /* No stage 1 entry? That means it's a new file */
 102                         if (!same) {
 103                                 show_new_file(ce);
 104                                 break;
 105                         }
 106                         /* Show difference between old and new */
 107                         show_modified(ac[1], ce, 1);
 108                         break;
 109                 case 1:
 110                         /* No stage 3 (merge) entry? That means it's been deleted */
 111                         if (!same) {
 112                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 113                                 break;
 114                         }
 115                         /* We come here with ce pointing at stage 1
 116                          * (original tree) and ac[1] pointing at stage
 117                          * 3 (unmerged).  show-modified with
 118                          * report-missing set to false does not say the
 119                          * file is deleted but reports true if work
 120                          * tree does not have it, in which case we
 121                          * fall through to report the unmerged state.
 122                          * Otherwise, we show the differences between
 123                          * the original tree and the work tree.
 124                          */
 125                         if (!cached_only && !show_modified(ce, ac[1], 0))
 126                                 break;
 127                         /* fallthru */
 128                 case 3:
 129                         diff_unmerge(&diff_options, ce->name);
 130                         break;
 131
 132                 default:
 133                         die("impossible cache entry stage");
 134                 }
 135
 136 skip_entry:
 137                 /*
 138                  * Ignore all the different stages for this file,
 139                  * we've handled the relevant cases now.
 140                  */
 141                 do {
 142                         ac++;
 143                         entries--;
 144                 } while (entries && ce_same_name(ce, ac[0]));
 145         }
 146         return 0;
 147 }
 148
 149 /*
 150  * This turns all merge entries into "stage 3". That guarantees that
 151  * when we read in the new tree (into "stage 1"), we won't lose sight
 152  * of the fact that we had unmerged entries.
 153  */
 154 static void mark_merge_entries(void)
 155 {
 156         int i;
 157         for (i = 0; i < active_nr; i++) {
 158                 struct cache_entry *ce = active_cache[i];
 159                 if (!ce_stage(ce))
 160                         continue;
 161                 ce->ce_flags |= htons(CE_STAGEMASK);
 162         }
 163 }
 164
 165 static const char diff_cache_usage[] =
 166 "git-diff-index [-m] [--cached] "
 167 "[<common diff options>] <tree-ish> [<path>...]"
 168 COMMON_DIFF_OPTIONS_HELP;
 169
 170 int main(int argc, const char **argv)
 171 {
 172         const char *tree_name = NULL;
 173         unsigned char sha1[20];
 174         const char *prefix = setup_git_directory();
 175         const char **pathspec = NULL;
 176         struct tree *tree;
 177         int ret;
 178         int allow_options = 1;
 179         int i;
 180
 181         git_config(git_diff_config);
 182         diff_setup(&diff_options);
 183         for (i = 1; i < argc; i++) {
 184                 const char *arg = argv[i];
 185                 int diff_opt_cnt;
 186
 187                 if (!allow_options || *arg != '-') {
 188                         if (tree_name)
 189                                 break;
 190                         tree_name = arg;
 191                         continue;
 192                 }
 193
 194                 if (!strcmp(arg, "--")) {
 195                         allow_options = 0;
 196                         continue;
 197                 }
 198                 if (!strcmp(arg, "-r")) {
 199                         /* We accept the -r flag just to look like git-diff-tree */
 200                         continue;
 201                 }
 202                 if (!strcmp(arg, "--cc"))
 203                         /*
 204                          * I _think_ "diff-index --cached HEAD" with an
 205                          * unmerged index could show something else
 206                          * later, but pretend --cc is the same as -p for
 207                          * now.  "git diff" uses --cc by default.
 208                          */
 209                         argv[i] = arg = "-p";
 210                 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
 211                                               argc - i);
 212                 if (diff_opt_cnt < 0)
 213                         usage(diff_cache_usage);
 214                 else if (diff_opt_cnt) {
 215                         i += diff_opt_cnt - 1;
 216                         continue;
 217                 }
 218
 219                 if (!strcmp(arg, "-m")) {
 220                         match_nonexisting = 1;
 221                         continue;
 222                 }
 223                 if (!strcmp(arg, "--cached")) {
 224                         cached_only = 1;
 225                         continue;
 226                 }
 227                 usage(diff_cache_usage);
 228         }
 229
 230         pathspec = get_pathspec(prefix, argv + i);
 231
 232         if (diff_setup_done(&diff_options) < 0)
 233                 usage(diff_cache_usage);
 234
 235         if (!tree_name || get_sha1(tree_name, sha1))
 236                 usage(diff_cache_usage);
 237
 238         read_cache();
 239
 240         mark_merge_entries();
 241
 242         tree = parse_tree_indirect(sha1);
 243         if (!tree)
 244                 die("bad tree object %s", tree_name);
 245         if (read_tree(tree, 1, pathspec))
 246                 die("unable to read tree object %s", tree_name);
 247
 248         ret = diff_cache(active_cache, active_nr, pathspec);
 249
 250         diffcore_std(&diff_options);
 251         diff_flush(&diff_options);
 252         return ret;
 253 }