diff-index.c

   1 #include "cache.h"
   2 #include "diff.h"
   3
   4 static int cached_only = 0;
   5 static int match_nonexisting = 0;
   6 static struct diff_options diff_options;
   7
   8 /* A file entry went away or appeared */
   9 static void show_file(const char *prefix,
  10                       struct cache_entry *ce,
  11                       unsigned char *sha1, unsigned int mode)
  12 {
  13         diff_addremove(&diff_options, prefix[0], ntohl(mode),
  14                        sha1, ce->name, NULL);
  15 }
  16
  17 static int get_stat_data(struct cache_entry *ce,
  18                          unsigned char **sha1p, unsigned int *modep)
  19 {
  20         unsigned char *sha1 = ce->sha1;
  21         unsigned int mode = ce->ce_mode;
  22
  23         if (!cached_only) {
  24                 static unsigned char no_sha1[20];
  25                 int changed;
  26                 struct stat st;
  27                 if (lstat(ce->name, &st) < 0) {
  28                         if (errno == ENOENT && match_nonexisting) {
  29                                 *sha1p = sha1;
  30                                 *modep = mode;
  31                                 return 0;
  32                         }
  33                         return -1;
  34                 }
  35                 changed = ce_match_stat(ce, &st);
  36                 if (changed) {
  37                         mode = create_ce_mode(st.st_mode);
  38                         sha1 = no_sha1;
  39                 }
  40         }
  41
  42         *sha1p = sha1;
  43         *modep = mode;
  44         return 0;
  45 }
  46
  47 static void show_new_file(struct cache_entry *new)
  48 {
  49         unsigned char *sha1;
  50         unsigned int mode;
  51
  52         /* New file in the index: it might actually be different in the working copy */
  53         if (get_stat_data(new, &sha1, &mode) < 0)
  54                 return;
  55
  56         show_file("+", new, sha1, mode);
  57 }
  58
  59 static int show_modified(struct cache_entry *old,
  60                          struct cache_entry *new,
  61                          int report_missing)
  62 {
  63         unsigned int mode, oldmode;
  64         unsigned char *sha1;
  65
  66         if (get_stat_data(new, &sha1, &mode) < 0) {
  67                 if (report_missing)
  68                         show_file("-", old, old->sha1, old->ce_mode);
  69                 return -1;
  70         }
  71
  72         oldmode = old->ce_mode;
  73         if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  74             !diff_options.find_copies_harder)
  75                 return 0;
  76
  77         mode = ntohl(mode);
  78         oldmode = ntohl(oldmode);
  79
  80         diff_change(&diff_options, oldmode, mode,
  81                     old->sha1, sha1, old->name, NULL);
  82         return 0;
  83 }
  84
  85 static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
  86 {
  87         while (entries) {
  88                 struct cache_entry *ce = *ac;
  89                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  90
  91                 if (!ce_path_match(ce, pathspec))
  92                         goto skip_entry;
  93
  94                 switch (ce_stage(ce)) {
  95                 case 0:
  96                         /* No stage 1 entry? That means it's a new file */
  97                         if (!same) {
  98                                 show_new_file(ce);
  99                                 break;
 100                         }
 101                         /* Show difference between old and new */
 102                         show_modified(ac[1], ce, 1);
 103                         break;
 104                 case 1:
 105                         /* No stage 3 (merge) entry? That means it's been deleted */
 106                         if (!same) {
 107                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 108                                 break;
 109                         }
 110                         /* We come here with ce pointing at stage 1
 111                          * (original tree) and ac[1] pointing at stage
 112                          * 3 (unmerged).  show-modified with
 113                          * report-mising set to false does not say the
 114                          * file is deleted but reports true if work
 115                          * tree does not have it, in which case we
 116                          * fall through to report the unmerged state.
 117                          * Otherwise, we show the differences between
 118                          * the original tree and the work tree.
 119                          */
 120                         if (!cached_only && !show_modified(ce, ac[1], 0))
 121                                 break;
 122                         /* fallthru */
 123                 case 3:
 124                         diff_unmerge(&diff_options, ce->name);
 125                         break;
 126
 127                 default:
 128                         die("impossible cache entry stage");
 129                 }
 130
 131 skip_entry:
 132                 /*
 133                  * Ignore all the different stages for this file,
 134                  * we've handled the relevant cases now.
 135                  */
 136                 do {
 137                         ac++;
 138                         entries--;
 139                 } while (entries && ce_same_name(ce, ac[0]));
 140         }
 141         return 0;
 142 }
 143
 144 /*
 145  * This turns all merge entries into "stage 3". That guarantees that
 146  * when we read in the new tree (into "stage 1"), we won't lose sight
 147  * of the fact that we had unmerged entries.
 148  */
 149 static void mark_merge_entries(void)
 150 {
 151         int i;
 152         for (i = 0; i < active_nr; i++) {
 153                 struct cache_entry *ce = active_cache[i];
 154                 if (!ce_stage(ce))
 155                         continue;
 156                 ce->ce_flags |= htons(CE_STAGEMASK);
 157         }
 158 }
 159
 160 static const char diff_cache_usage[] =
 161 "git-diff-index [-m] [--cached] "
 162 "[<common diff options>] <tree-ish> [<path>...]"
 163 COMMON_DIFF_OPTIONS_HELP;
 164
 165 int main(int argc, const char **argv)
 166 {
 167         const char *tree_name = NULL;
 168         unsigned char sha1[20];
 169         const char *prefix = setup_git_directory();
 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         diff_setup(&diff_options);
 178         for (i = 1; i < argc; i++) {
 179                 const char *arg = argv[i];
 180                 int diff_opt_cnt;
 181
 182                 if (!allow_options || *arg != '-') {
 183                         if (tree_name)
 184                                 break;
 185                         tree_name = arg;
 186                         continue;
 187                 }
 188
 189                 if (!strcmp(arg, "--")) {
 190                         allow_options = 0;
 191                         continue;
 192                 }
 193                 if (!strcmp(arg, "-r")) {
 194                         /* We accept the -r flag just to look like git-diff-tree */
 195                         continue;
 196                 }
 197                 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
 198                                               argc - i);
 199                 if (diff_opt_cnt < 0)
 200                         usage(diff_cache_usage);
 201                 else if (diff_opt_cnt) {
 202                         i += diff_opt_cnt - 1;
 203                         continue;
 204                 }
 205
 206                 if (!strcmp(arg, "-m")) {
 207                         match_nonexisting = 1;
 208                         continue;
 209                 }
 210                 if (!strcmp(arg, "--cached")) {
 211                         cached_only = 1;
 212                         continue;
 213                 }
 214                 usage(diff_cache_usage);
 215         }
 216
 217         pathspec = get_pathspec(prefix, argv + i);
 218
 219         if (diff_setup_done(&diff_options) < 0)
 220                 usage(diff_cache_usage);
 221
 222         if (!tree_name || get_sha1(tree_name, sha1))
 223                 usage(diff_cache_usage);
 224
 225         read_cache();
 226
 227         mark_merge_entries();
 228
 229         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 230         if (!tree)
 231                 die("bad tree object %s", tree_name);
 232         if (read_tree(tree, size, 1, pathspec))
 233                 die("unable to read tree object %s", tree_name);
 234
 235         ret = diff_cache(active_cache, active_nr, pathspec);
 236
 237         diffcore_std(&diff_options);
 238         diff_flush(&diff_options);
 239         return ret;
 240 }