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                         if (!trust_executable_bit &&
  39                             S_ISREG(mode) && S_ISREG(ce->ce_mode) &&
  40                             ((mode ^ ce->ce_mode) == 0111))
  41                                 mode = ce->ce_mode;
  42                         sha1 = no_sha1;
  43                 }
  44         }
  45
  46         *sha1p = sha1;
  47         *modep = mode;
  48         return 0;
  49 }
  50
  51 static void show_new_file(struct cache_entry *new)
  52 {
  53         unsigned char *sha1;
  54         unsigned int mode;
  55
  56         /* New file in the index: it might actually be different in
  57          * the working copy.
  58          */
  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             !diff_options.find_copies_harder)
  81                 return 0;
  82
  83         mode = ntohl(mode);
  84         oldmode = ntohl(oldmode);
  85
  86         diff_change(&diff_options, 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-missing 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(&diff_options, 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-index [-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 *prefix = setup_git_directory();
 176         const char **pathspec = NULL;
 177         void *tree;
 178         unsigned long size;
 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                 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
 205                                               argc - i);
 206                 if (diff_opt_cnt < 0)
 207                         usage(diff_cache_usage);
 208                 else if (diff_opt_cnt) {
 209                         i += diff_opt_cnt - 1;
 210                         continue;
 211                 }
 212
 213                 if (!strcmp(arg, "-m")) {
 214                         match_nonexisting = 1;
 215                         continue;
 216                 }
 217                 if (!strcmp(arg, "--cached")) {
 218                         cached_only = 1;
 219                         continue;
 220                 }
 221                 usage(diff_cache_usage);
 222         }
 223
 224         pathspec = get_pathspec(prefix, argv + i);
 225
 226         if (diff_setup_done(&diff_options) < 0)
 227                 usage(diff_cache_usage);
 228
 229         if (!tree_name || get_sha1(tree_name, sha1))
 230                 usage(diff_cache_usage);
 231
 232         read_cache();
 233
 234         mark_merge_entries();
 235
 236         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 237         if (!tree)
 238                 die("bad tree object %s", tree_name);
 239         if (read_tree(tree, size, 1, pathspec))
 240                 die("unable to read tree object %s", tree_name);
 241
 242         ret = diff_cache(active_cache, active_nr, pathspec);
 243
 244         diffcore_std(&diff_options);
 245         diff_flush(&diff_options);
 246         return ret;
 247 }