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
  10 /* A file entry went away or appeared */
  11 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  12 {
  13         if (generate_patch)
  14                 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  15         else
  16                 printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
  17                        sha1_to_hex(sha1), ce->name, line_termination);
  18 }
  19
  20 static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
  21 {
  22         unsigned char *sha1 = ce->sha1;
  23         unsigned int mode = ce->ce_mode;
  24
  25         if (!cached_only) {
  26                 static unsigned char no_sha1[20];
  27                 int changed;
  28                 struct stat st;
  29                 if (lstat(ce->name, &st) < 0) {
  30                         if (errno == ENOENT && match_nonexisting) {
  31                                 *sha1p = sha1;
  32                                 *modep = mode;
  33                                 return 0;
  34                         }
  35                         return -1;
  36                 }
  37                 changed = ce_match_stat(ce, &st);
  38                 if (changed) {
  39                         mode = create_ce_mode(st.st_mode);
  40                         sha1 = no_sha1;
  41                 }
  42         }
  43
  44         *sha1p = sha1;
  45         *modep = mode;
  46         return 0;
  47 }
  48
  49 static void show_new_file(struct cache_entry *new)
  50 {
  51         unsigned char *sha1;
  52         unsigned int mode;
  53
  54         /* New file in the index: it might actually be different in the working copy */
  55         if (get_stat_data(new, &sha1, &mode) < 0)
  56                 return;
  57
  58         show_file("+", new, sha1, mode);
  59 }
  60
  61 static int show_modified(struct cache_entry *old,
  62                          struct cache_entry *new,
  63                          int report_missing)
  64 {
  65         unsigned int mode, oldmode;
  66         unsigned char *sha1;
  67         char old_sha1_hex[60];
  68
  69         if (get_stat_data(new, &sha1, &mode) < 0) {
  70                 if (report_missing)
  71                         show_file("-", old, old->sha1, old->ce_mode);
  72                 return -1;
  73         }
  74
  75         oldmode = old->ce_mode;
  76         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  77                 return 0;
  78
  79         mode = ntohl(mode);
  80         oldmode = ntohl(oldmode);
  81
  82         if (generate_patch)
  83                 diff_change(oldmode, mode,
  84                             old->sha1, sha1, old->name, NULL);
  85         else {
  86                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
  87                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
  88                        old_sha1_hex, sha1_to_hex(sha1),
  89                        old->name, line_termination);
  90         }
  91         return 0;
  92 }
  93
  94 static int diff_cache(struct cache_entry **ac, int entries)
  95 {
  96         while (entries) {
  97                 struct cache_entry *ce = *ac;
  98                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  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-mising 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                         if (generate_patch)
 131                                 diff_unmerge(ce->name);
 132                         else
 133                                 printf("U %s%c", ce->name, line_termination);
 134                         break;
 135
 136                 default:
 137                         die("impossible cache entry stage");
 138                 }
 139
 140                 /*
 141                  * Ignore all the different stages for this file,
 142                  * we've handled the relevant cases now.
 143                  */
 144                 do {
 145                         ac++;
 146                         entries--;
 147                 } while (entries && ce_same_name(ce, ac[0]));
 148         }
 149         return 0;
 150 }
 151
 152 /*
 153  * This turns all merge entries into "stage 3". That guarantees that
 154  * when we read in the new tree (into "stage 1"), we won't lose sight
 155  * of the fact that we had unmerged entries.
 156  */
 157 static void mark_merge_entries(void)
 158 {
 159         int i;
 160         for (i = 0; i < active_nr; i++) {
 161                 struct cache_entry *ce = active_cache[i];
 162                 if (!ce_stage(ce))
 163                         continue;
 164                 ce->ce_flags |= htons(CE_STAGEMASK);
 165         }
 166 }
 167
 168 static char *diff_cache_usage =
 169 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>";
 170
 171 int main(int argc, char **argv)
 172 {
 173         unsigned char tree_sha1[20];
 174         void *tree;
 175         unsigned long size;
 176         int ret;
 177
 178         read_cache();
 179         while (argc > 2) {
 180                 char *arg = argv[1];
 181                 argv++;
 182                 argc--;
 183                 if (!strcmp(arg, "-r")) {
 184                         /* We accept the -r flag just to look like diff-tree */
 185                         continue;
 186                 }
 187                 if (!strcmp(arg, "-p")) {
 188                         generate_patch = 1;
 189                         continue;
 190                 }
 191                 if (!strcmp(arg, "-M")) {
 192                         generate_patch = detect_rename = 1;
 193                         continue;
 194                 }
 195                 if (!strcmp(arg, "-z")) {
 196                         line_termination = '\0';
 197                         continue;
 198                 }
 199                 if (!strcmp(arg, "-m")) {
 200                         match_nonexisting = 1;
 201                         continue;
 202                 }
 203                 if (!strcmp(arg, "--cached")) {
 204                         cached_only = 1;
 205                         continue;
 206                 }
 207                 usage(diff_cache_usage);
 208         }
 209
 210         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 211                 usage(diff_cache_usage);
 212
 213         if (generate_patch)
 214                 diff_setup(detect_rename, 0, 0, 0, 0);
 215
 216         mark_merge_entries();
 217
 218         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
 219         if (!tree)
 220                 die("bad tree object %s", argv[1]);
 221         if (read_tree(tree, size, 1))
 222                 die("unable to read tree object %s", argv[1]);
 223
 224         ret = diff_cache(active_cache, active_nr);
 225         if (generate_patch)
 226                 diff_flush();
 227         return ret;
 228 }