diff-cache.c

   1 #include "cache.h"
   2 #include "diff.h"
   3
   4 static int cached_only = 0;
   5 static int generate_patch = 0;
   6 static int match_nonexisting = 0;
   7 static int line_termination = '\n';
   8 static int detect_rename = 0;
   9 static int reverse_diff = 0;
  10 static int diff_score_opt = 0;
  11
  12 /* A file entry went away or appeared */
  13 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  14 {
  15         diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  16 }
  17
  18 static int get_stat_data(struct cache_entry *ce, 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                 return 0;
  75
  76         mode = ntohl(mode);
  77         oldmode = ntohl(oldmode);
  78
  79         diff_change(oldmode, mode,
  80                     old->sha1, sha1, old->name, NULL);
  81         return 0;
  82 }
  83
  84 static int diff_cache(struct cache_entry **ac, int entries)
  85 {
  86         while (entries) {
  87                 struct cache_entry *ce = *ac;
  88                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  89
  90                 switch (ce_stage(ce)) {
  91                 case 0:
  92                         /* No stage 1 entry? That means it's a new file */
  93                         if (!same) {
  94                                 show_new_file(ce);
  95                                 break;
  96                         }
  97                         /* Show difference between old and new */
  98                         show_modified(ac[1], ce, 1);
  99                         break;
 100                 case 1:
 101                         /* No stage 3 (merge) entry? That means it's been deleted */
 102                         if (!same) {
 103                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 104                                 break;
 105                         }
 106                         /* We come here with ce pointing at stage 1
 107                          * (original tree) and ac[1] pointing at stage
 108                          * 3 (unmerged).  show-modified with
 109                          * report-mising set to false does not say the
 110                          * file is deleted but reports true if work
 111                          * tree does not have it, in which case we
 112                          * fall through to report the unmerged state.
 113                          * Otherwise, we show the differences between
 114                          * the original tree and the work tree.
 115                          */
 116                         if (!cached_only && !show_modified(ce, ac[1], 0))
 117                                 break;
 118                         /* fallthru */
 119                 case 3:
 120                         diff_unmerge(ce->name);
 121                         break;
 122
 123                 default:
 124                         die("impossible cache entry stage");
 125                 }
 126
 127                 /*
 128                  * Ignore all the different stages for this file,
 129                  * we've handled the relevant cases now.
 130                  */
 131                 do {
 132                         ac++;
 133                         entries--;
 134                 } while (entries && ce_same_name(ce, ac[0]));
 135         }
 136         return 0;
 137 }
 138
 139 /*
 140  * This turns all merge entries into "stage 3". That guarantees that
 141  * when we read in the new tree (into "stage 1"), we won't lose sight
 142  * of the fact that we had unmerged entries.
 143  */
 144 static void mark_merge_entries(void)
 145 {
 146         int i;
 147         for (i = 0; i < active_nr; i++) {
 148                 struct cache_entry *ce = active_cache[i];
 149                 if (!ce_stage(ce))
 150                         continue;
 151                 ce->ce_flags |= htons(CE_STAGEMASK);
 152         }
 153 }
 154
 155 static char *diff_cache_usage =
 156 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-R] [--cached] <tree-ish>";
 157
 158 int main(int argc, char **argv)
 159 {
 160         unsigned char tree_sha1[20];
 161         void *tree;
 162         unsigned long size;
 163         int ret;
 164
 165         read_cache();
 166         while (argc > 2) {
 167                 char *arg = argv[1];
 168                 argv++;
 169                 argc--;
 170                 if (!strcmp(arg, "-r")) {
 171                         /* We accept the -r flag just to look like git-diff-tree */
 172                         continue;
 173                 }
 174                 if (!strcmp(arg, "-p")) {
 175                         generate_patch = 1;
 176                         continue;
 177                 }
 178                 if (!strncmp(arg, "-M", 2)) {
 179                         generate_patch = detect_rename = 1;
 180                         diff_score_opt = diff_scoreopt_parse(arg);
 181                         continue;
 182                 }
 183                 if (!strcmp(arg, "-z")) {
 184                         line_termination = '\0';
 185                         continue;
 186                 }
 187                 if (!strcmp(arg, "-R")) {
 188                         reverse_diff = 1;
 189                         continue;
 190                 }
 191                 if (!strcmp(arg, "-m")) {
 192                         match_nonexisting = 1;
 193                         continue;
 194                 }
 195                 if (!strcmp(arg, "--cached")) {
 196                         cached_only = 1;
 197                         continue;
 198                 }
 199                 usage(diff_cache_usage);
 200         }
 201
 202         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 203                 usage(diff_cache_usage);
 204
 205         diff_setup(detect_rename, diff_score_opt, reverse_diff,
 206                    (generate_patch ? -1 : line_termination),
 207                    0, 0);
 208
 209         mark_merge_entries();
 210
 211         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
 212         if (!tree)
 213                 die("bad tree object %s", argv[1]);
 214         if (read_tree(tree, size, 1))
 215                 die("unable to read tree object %s", argv[1]);
 216
 217         ret = diff_cache(active_cache, active_nr);
 218         diff_flush();
 219         return ret;
 220 }