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 static char *pickaxe = 0;
  12
  13 /* A file entry went away or appeared */
  14 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  15 {
  16         diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  17 }
  18
  19 static int get_stat_data(struct cache_entry *ce, 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);
  37                 if (changed) {
  38                         mode = create_ce_mode(st.st_mode);
  39                         sha1 = no_sha1;
  40                 }
  41         }
  42
  43         *sha1p = sha1;
  44         *modep = mode;
  45         return 0;
  46 }
  47
  48 static void show_new_file(struct cache_entry *new)
  49 {
  50         unsigned char *sha1;
  51         unsigned int mode;
  52
  53         /* New file in the index: it might actually be different in the working copy */
  54         if (get_stat_data(new, &sha1, &mode) < 0)
  55                 return;
  56
  57         show_file("+", new, sha1, mode);
  58 }
  59
  60 static int show_modified(struct cache_entry *old,
  61                          struct cache_entry *new,
  62                          int report_missing)
  63 {
  64         unsigned int mode, oldmode;
  65         unsigned char *sha1;
  66
  67         if (get_stat_data(new, &sha1, &mode) < 0) {
  68                 if (report_missing)
  69                         show_file("-", old, old->sha1, old->ce_mode);
  70                 return -1;
  71         }
  72
  73         oldmode = old->ce_mode;
  74         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  75                 return 0;
  76
  77         mode = ntohl(mode);
  78         oldmode = ntohl(oldmode);
  79
  80         diff_change(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)
  86 {
  87         while (entries) {
  88                 struct cache_entry *ce = *ac;
  89                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  90
  91                 switch (ce_stage(ce)) {
  92                 case 0:
  93                         /* No stage 1 entry? That means it's a new file */
  94                         if (!same) {
  95                                 show_new_file(ce);
  96                                 break;
  97                         }
  98                         /* Show difference between old and new */
  99                         show_modified(ac[1], ce, 1);
 100                         break;
 101                 case 1:
 102                         /* No stage 3 (merge) entry? That means it's been deleted */
 103                         if (!same) {
 104                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 105                                 break;
 106                         }
 107                         /* We come here with ce pointing at stage 1
 108                          * (original tree) and ac[1] pointing at stage
 109                          * 3 (unmerged).  show-modified with
 110                          * report-mising set to false does not say the
 111                          * file is deleted but reports true if work
 112                          * tree does not have it, in which case we
 113                          * fall through to report the unmerged state.
 114                          * Otherwise, we show the differences between
 115                          * the original tree and the work tree.
 116                          */
 117                         if (!cached_only && !show_modified(ce, ac[1], 0))
 118                                 break;
 119                         /* fallthru */
 120                 case 3:
 121                         diff_unmerge(ce->name);
 122                         break;
 123
 124                 default:
 125                         die("impossible cache entry stage");
 126                 }
 127
 128                 /*
 129                  * Ignore all the different stages for this file,
 130                  * we've handled the relevant cases now.
 131                  */
 132                 do {
 133                         ac++;
 134                         entries--;
 135                 } while (entries && ce_same_name(ce, ac[0]));
 136         }
 137         return 0;
 138 }
 139
 140 /*
 141  * This turns all merge entries into "stage 3". That guarantees that
 142  * when we read in the new tree (into "stage 1"), we won't lose sight
 143  * of the fact that we had unmerged entries.
 144  */
 145 static void mark_merge_entries(void)
 146 {
 147         int i;
 148         for (i = 0; i < active_nr; i++) {
 149                 struct cache_entry *ce = active_cache[i];
 150                 if (!ce_stage(ce))
 151                         continue;
 152                 ce->ce_flags |= htons(CE_STAGEMASK);
 153         }
 154 }
 155
 156 static char *diff_cache_usage =
 157 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish>";
 158
 159 int main(int argc, char **argv)
 160 {
 161         unsigned char tree_sha1[20];
 162         void *tree;
 163         unsigned long size;
 164         int ret;
 165
 166         read_cache();
 167         while (argc > 2) {
 168                 char *arg = argv[1];
 169                 argv++;
 170                 argc--;
 171                 if (!strcmp(arg, "-r")) {
 172                         /* We accept the -r flag just to look like git-diff-tree */
 173                         continue;
 174                 }
 175                 if (!strcmp(arg, "-p")) {
 176                         generate_patch = 1;
 177                         continue;
 178                 }
 179                 if (!strncmp(arg, "-M", 2)) {
 180                         generate_patch = detect_rename = 1;
 181                         diff_score_opt = diff_scoreopt_parse(arg);
 182                         continue;
 183                 }
 184                 if (!strncmp(arg, "-C", 2)) {
 185                         generate_patch = 1;
 186                         detect_rename = 2;
 187                         diff_score_opt = diff_scoreopt_parse(arg);
 188                         continue;
 189                 }
 190                 if (!strcmp(arg, "-z")) {
 191                         line_termination = '\0';
 192                         continue;
 193                 }
 194                 if (!strcmp(arg, "-R")) {
 195                         reverse_diff = 1;
 196                         continue;
 197                 }
 198                 if (!strcmp(arg, "-S")) {
 199                         pickaxe = arg + 2;
 200                         continue;
 201                 }
 202                 if (!strcmp(arg, "-m")) {
 203                         match_nonexisting = 1;
 204                         continue;
 205                 }
 206                 if (!strcmp(arg, "--cached")) {
 207                         cached_only = 1;
 208                         continue;
 209                 }
 210                 usage(diff_cache_usage);
 211         }
 212
 213         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 214                 usage(diff_cache_usage);
 215
 216         diff_setup(detect_rename, diff_score_opt, pickaxe,
 217                    reverse_diff, (generate_patch ? -1 : line_termination),
 218                    NULL, 0);
 219
 220         mark_merge_entries();
 221
 222         tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
 223         if (!tree)
 224                 die("bad tree object %s", argv[1]);
 225         if (read_tree(tree, size, 1))
 226                 die("unable to read tree object %s", argv[1]);
 227
 228         ret = diff_cache(active_cache, active_nr);
 229         diff_flush();
 230         return ret;
 231 }