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
   9 /* A file entry went away or appeared */
  10 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  11 {
  12         if (generate_patch)
  13                 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  14         else
  15                 printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
  16                        sha1_to_hex(sha1), ce->name, line_termination);
  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 = cache_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, struct cache_entry *new)
  61 {
  62         unsigned int mode, oldmode;
  63         unsigned char *sha1;
  64         unsigned char old_sha1_hex[60];
  65
  66         if (get_stat_data(new, &sha1, &mode) < 0) {
  67                 show_file("-", old, old->sha1, old->ce_mode);
  68                 return -1;
  69         }
  70
  71         oldmode = old->ce_mode;
  72         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  73                 return 0;
  74
  75         mode = ntohl(mode);
  76         oldmode = ntohl(oldmode);
  77
  78         if (generate_patch)
  79                 diff_change(oldmode, mode,
  80                             old->sha1, sha1, old->name, NULL);
  81         else {
  82                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
  83                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
  84                        old_sha1_hex, sha1_to_hex(sha1),
  85                        old->name, line_termination);
  86         }
  87         return 0;
  88 }
  89
  90 static int diff_cache(struct cache_entry **ac, int entries)
  91 {
  92         while (entries) {
  93                 struct cache_entry *ce = *ac;
  94                 int same = (entries > 1) && same_name(ce, ac[1]);
  95
  96                 switch (ce_stage(ce)) {
  97                 case 0:
  98                         /* No stage 1 entry? That means it's a new file */
  99                         if (!same) {
 100                                 show_new_file(ce);
 101                                 break;
 102                         }
 103                         /* Show difference between old and new */
 104                         show_modified(ac[1], ce);
 105                         break;
 106                 case 1:
 107                         /* No stage 3 (merge) entry? That means it's been deleted */
 108                         if (!same) {
 109                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 110                                 break;
 111                         }
 112                         /* Otherwise we fall through to the "unmerged" case */
 113                 case 3:
 114                         if (generate_patch)
 115                                 diff_unmerge(ce->name);
 116                         else
 117                                 printf("U %s%c", ce->name, line_termination);
 118                         break;
 119
 120                 default:
 121                         die("impossible cache entry stage");
 122                 }
 123
 124                 /*
 125                  * Ignore all the different stages for this file,
 126                  * we've handled the relevant cases now.
 127                  */
 128                 do {
 129                         ac++;
 130                         entries--;
 131                 } while (entries && same_name(ce, ac[0]));
 132         }
 133         return 0;
 134 }
 135
 136 /*
 137  * This turns all merge entries into "stage 3". That guarantees that
 138  * when we read in the new tree (into "stage 1"), we won't lose sight
 139  * of the fact that we had unmerged entries.
 140  */
 141 static void mark_merge_entries(void)
 142 {
 143         int i;
 144         for (i = 0; i < active_nr; i++) {
 145                 struct cache_entry *ce = active_cache[i];
 146                 if (!ce_stage(ce))
 147                         continue;
 148                 ce->ce_flags |= htons(CE_STAGEMASK);
 149         }
 150 }
 151
 152 static char *diff_cache_usage =
 153 "diff-cache [-r] [-z] [-p] [-i] [--cached] <tree sha1>";
 154
 155 int main(int argc, char **argv)
 156 {
 157         unsigned char tree_sha1[20];
 158         void *tree;
 159         unsigned long size;
 160
 161         read_cache();
 162         while (argc > 2) {
 163                 char *arg = argv[1];
 164                 argv++;
 165                 argc--;
 166                 if (!strcmp(arg, "-r")) {
 167                         /* We accept the -r flag just to look like diff-tree */
 168                         continue;
 169                 }
 170                 if (!strcmp(arg, "-p")) {
 171                         generate_patch = 1;
 172                         continue;
 173                 }
 174                 if (!strcmp(arg, "-z")) {
 175                         line_termination = '\0';
 176                         continue;
 177                 }
 178                 if (!strcmp(arg, "-m")) {
 179                         match_nonexisting = 1;
 180                         continue;
 181                 }
 182                 if (!strcmp(arg, "--cached")) {
 183                         cached_only = 1;
 184                         continue;
 185                 }
 186                 usage(diff_cache_usage);
 187         }
 188
 189         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 190                 usage(diff_cache_usage);
 191
 192         mark_merge_entries();
 193
 194         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
 195         if (!tree)
 196                 die("bad tree object %s", argv[1]);
 197         if (read_tree(tree, size, 1))
 198                 die("unable to read tree object %s", argv[1]);
 199
 200         return diff_cache(active_cache, active_nr);
 201 }