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 line_termination = '\n';
   7
   8 /* A file entry went away or appeared */
   9 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  10 {
  11         if (generate_patch)
  12                 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  13         else
  14                 printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
  15                        sha1_to_hex(sha1), ce->name, line_termination);
  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 (stat(ce->name, &st) < 0)
  28                         return -1;
  29                 changed = cache_match_stat(ce, &st);
  30                 if (changed) {
  31                         mode = create_ce_mode(st.st_mode);
  32                         sha1 = no_sha1;
  33                 }
  34         }
  35
  36         *sha1p = sha1;
  37         *modep = mode;
  38         return 0;
  39 }
  40
  41 static void show_new_file(struct cache_entry *new)
  42 {
  43         unsigned char *sha1;
  44         unsigned int mode;
  45
  46         /* New file in the index: it might actually be different in the working copy */
  47         if (get_stat_data(new, &sha1, &mode) < 0)
  48                 return;
  49
  50         show_file("+", new, sha1, mode);
  51 }
  52
  53 static int show_modified(struct cache_entry *old, struct cache_entry *new)
  54 {
  55         unsigned int mode, oldmode;
  56         unsigned char *sha1;
  57         unsigned char old_sha1_hex[60];
  58
  59         if (get_stat_data(new, &sha1, &mode) < 0) {
  60                 show_file("-", old, old->sha1, old->ce_mode);
  61                 return -1;
  62         }
  63
  64         oldmode = old->ce_mode;
  65         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  66                 return 0;
  67
  68         mode = ntohl(mode);
  69         oldmode = ntohl(oldmode);
  70
  71         if (generate_patch)
  72                 diff_change(oldmode, mode,
  73                             old->sha1, sha1, old->name, NULL);
  74         else {
  75                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
  76                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
  77                        old_sha1_hex, sha1_to_hex(sha1),
  78                        old->name, line_termination);
  79         }
  80         return 0;
  81 }
  82
  83 static int diff_cache(struct cache_entry **ac, int entries)
  84 {
  85         while (entries) {
  86                 struct cache_entry *ce = *ac;
  87                 int same = (entries > 1) && same_name(ce, ac[1]);
  88
  89                 switch (ce_stage(ce)) {
  90                 case 0:
  91                         /* No stage 1 entry? That means it's a new file */
  92                         if (!same) {
  93                                 show_new_file(ce);
  94                                 break;
  95                         }
  96                         /* Show difference between old and new */
  97                         show_modified(ac[1], ce);
  98                         break;
  99                 case 1:
 100                         /* No stage 3 (merge) entry? That means it's been deleted */
 101                         if (!same) {
 102                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 103                                 break;
 104                         }
 105                         /* Otherwise we fall through to the "unmerged" case */
 106                 case 3:
 107                         if (generate_patch)
 108                                 diff_unmerge(ce->name);
 109                         else
 110                                 printf("U %s%c", ce->name, line_termination);
 111                         break;
 112
 113                 default:
 114                         die("impossible cache entry stage");
 115                 }
 116
 117                 /*
 118                  * Ignore all the different stages for this file,
 119                  * we've handled the relevant cases now.
 120                  */
 121                 do {
 122                         ac++;
 123                         entries--;
 124                 } while (entries && same_name(ce, ac[0]));
 125         }
 126         return 0;
 127 }
 128
 129 /*
 130  * This turns all merge entries into "stage 3". That guarantees that
 131  * when we read in the new tree (into "stage 1"), we won't lose sight
 132  * of the fact that we had unmerged entries.
 133  */
 134 static void mark_merge_entries(void)
 135 {
 136         int i;
 137         for (i = 0; i < active_nr; i++) {
 138                 struct cache_entry *ce = active_cache[i];
 139                 if (!ce_stage(ce))
 140                         continue;
 141                 ce->ce_flags |= htons(CE_STAGEMASK);
 142         }
 143 }
 144
 145 static char *diff_cache_usage =
 146 "diff-cache [-r] [-z] [-p] [--cached] <tree sha1>";
 147
 148 int main(int argc, char **argv)
 149 {
 150         unsigned char tree_sha1[20];
 151         void *tree;
 152         unsigned long size;
 153
 154         read_cache();
 155         while (argc > 2) {
 156                 char *arg = argv[1];
 157                 argv++;
 158                 argc--;
 159                 if (!strcmp(arg, "-r")) {
 160                         /* We accept the -r flag just to look like diff-tree */
 161                         continue;
 162                 }
 163                 if (!strcmp(arg, "-p")) {
 164                         generate_patch = 1;
 165                         continue;
 166                 }
 167                 if (!strcmp(arg, "-z")) {
 168                         line_termination = '\0';
 169                         continue;
 170                 }
 171                 if (!strcmp(arg, "--cached")) {
 172                         cached_only = 1;
 173                         continue;
 174                 }
 175                 usage(diff_cache_usage);
 176         }
 177
 178         if (argc != 2 || get_sha1_hex(argv[1], tree_sha1))
 179                 usage(diff_cache_usage);
 180
 181         mark_merge_entries();
 182
 183         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
 184         if (!tree)
 185                 die("bad tree object %s", argv[1]);
 186         if (read_tree(tree, size, 1))
 187                 die("unable to read tree object %s", argv[1]);
 188
 189         return diff_cache(active_cache, active_nr);
 190 }