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 const char *pickaxe = NULL;
  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             detect_rename < 2)
  76                 return 0;
  77
  78         mode = ntohl(mode);
  79         oldmode = ntohl(oldmode);
  80
  81         diff_change(oldmode, mode,
  82                     old->sha1, sha1, old->name, NULL);
  83         return 0;
  84 }
  85
  86 static int diff_cache(struct cache_entry **ac, int entries)
  87 {
  88         while (entries) {
  89                 struct cache_entry *ce = *ac;
  90                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  91
  92                 switch (ce_stage(ce)) {
  93                 case 0:
  94                         /* No stage 1 entry? That means it's a new file */
  95                         if (!same) {
  96                                 show_new_file(ce);
  97                                 break;
  98                         }
  99                         /* Show difference between old and new */
 100                         show_modified(ac[1], ce, 1);
 101                         break;
 102                 case 1:
 103                         /* No stage 3 (merge) entry? That means it's been deleted */
 104                         if (!same) {
 105                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 106                                 break;
 107                         }
 108                         /* We come here with ce pointing at stage 1
 109                          * (original tree) and ac[1] pointing at stage
 110                          * 3 (unmerged).  show-modified with
 111                          * report-mising set to false does not say the
 112                          * file is deleted but reports true if work
 113                          * tree does not have it, in which case we
 114                          * fall through to report the unmerged state.
 115                          * Otherwise, we show the differences between
 116                          * the original tree and the work tree.
 117                          */
 118                         if (!cached_only && !show_modified(ce, ac[1], 0))
 119                                 break;
 120                         /* fallthru */
 121                 case 3:
 122                         diff_unmerge(ce->name);
 123                         break;
 124
 125                 default:
 126                         die("impossible cache entry stage");
 127                 }
 128
 129                 /*
 130                  * Ignore all the different stages for this file,
 131                  * we've handled the relevant cases now.
 132                  */
 133                 do {
 134                         ac++;
 135                         entries--;
 136                 } while (entries && ce_same_name(ce, ac[0]));
 137         }
 138         return 0;
 139 }
 140
 141 /*
 142  * This turns all merge entries into "stage 3". That guarantees that
 143  * when we read in the new tree (into "stage 1"), we won't lose sight
 144  * of the fact that we had unmerged entries.
 145  */
 146 static void mark_merge_entries(void)
 147 {
 148         int i;
 149         for (i = 0; i < active_nr; i++) {
 150                 struct cache_entry *ce = active_cache[i];
 151                 if (!ce_stage(ce))
 152                         continue;
 153                 ce->ce_flags |= htons(CE_STAGEMASK);
 154         }
 155 }
 156
 157 static char *diff_cache_usage =
 158 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish>";
 159
 160 int main(int argc, char **argv)
 161 {
 162         unsigned char tree_sha1[20];
 163         void *tree;
 164         unsigned long size;
 165         int ret;
 166
 167         read_cache();
 168         while (argc > 2) {
 169                 char *arg = argv[1];
 170                 argv++;
 171                 argc--;
 172                 if (!strcmp(arg, "-r")) {
 173                         /* We accept the -r flag just to look like git-diff-tree */
 174                         continue;
 175                 }
 176                 if (!strcmp(arg, "-p")) {
 177                         generate_patch = 1;
 178                         continue;
 179                 }
 180                 if (!strncmp(arg, "-M", 2)) {
 181                         generate_patch = detect_rename = 1;
 182                         diff_score_opt = diff_scoreopt_parse(arg);
 183                         continue;
 184                 }
 185                 if (!strncmp(arg, "-C", 2)) {
 186                         generate_patch = 1;
 187                         detect_rename = 2;
 188                         diff_score_opt = diff_scoreopt_parse(arg);
 189                         continue;
 190                 }
 191                 if (!strcmp(arg, "-z")) {
 192                         line_termination = '\0';
 193                         continue;
 194                 }
 195                 if (!strcmp(arg, "-R")) {
 196                         reverse_diff = 1;
 197                         continue;
 198                 }
 199                 if (!strcmp(arg, "-S")) {
 200                         pickaxe = arg + 2;
 201                         continue;
 202                 }
 203                 if (!strcmp(arg, "-m")) {
 204                         match_nonexisting = 1;
 205                         continue;
 206                 }
 207                 if (!strcmp(arg, "--cached")) {
 208                         cached_only = 1;
 209                         continue;
 210                 }
 211                 usage(diff_cache_usage);
 212         }
 213
 214         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 215                 usage(diff_cache_usage);
 216
 217         diff_setup(detect_rename, diff_score_opt, pickaxe,
 218                    reverse_diff, (generate_patch ? -1 : line_termination),
 219                    NULL, 0);
 220
 221         mark_merge_entries();
 222
 223         tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
 224         if (!tree)
 225                 die("bad tree object %s", argv[1]);
 226         if (read_tree(tree, size, 1))
 227                 die("unable to read tree object %s", argv[1]);
 228
 229         ret = diff_cache(active_cache, active_nr);
 230         diff_flush();
 231         return ret;
 232 }