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,
  61                          struct cache_entry *new,
  62                          int report_missing)
  63 {
  64         unsigned int mode, oldmode;
  65         unsigned char *sha1;
  66         unsigned char old_sha1_hex[60];
  67
  68         if (get_stat_data(new, &sha1, &mode) < 0) {
  69                 if (report_missing)
  70                         show_file("-", old, old->sha1, old->ce_mode);
  71                 return -1;
  72         }
  73
  74         oldmode = old->ce_mode;
  75         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  76                 return 0;
  77
  78         mode = ntohl(mode);
  79         oldmode = ntohl(oldmode);
  80
  81         if (generate_patch)
  82                 diff_change(oldmode, mode,
  83                             old->sha1, sha1, old->name, NULL);
  84         else {
  85                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
  86                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
  87                        old_sha1_hex, sha1_to_hex(sha1),
  88                        old->name, line_termination);
  89         }
  90         return 0;
  91 }
  92
  93 static int diff_cache(struct cache_entry **ac, int entries)
  94 {
  95         while (entries) {
  96                 struct cache_entry *ce = *ac;
  97                 int same = (entries > 1) && same_name(ce, ac[1]);
  98
  99                 switch (ce_stage(ce)) {
 100                 case 0:
 101                         /* No stage 1 entry? That means it's a new file */
 102                         if (!same) {
 103                                 show_new_file(ce);
 104                                 break;
 105                         }
 106                         /* Show difference between old and new */
 107                         show_modified(ac[1], ce, 1);
 108                         break;
 109                 case 1:
 110                         /* No stage 3 (merge) entry? That means it's been deleted */
 111                         if (!same) {
 112                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 113                                 break;
 114                         }
 115                         /* We come here with ce pointing at stage 1
 116                          * (original tree) and ac[1] pointing at stage
 117                          * 3 (unmerged).  show-modified with
 118                          * report-mising set to false does not say the
 119                          * file is deleted but reports true if work
 120                          * tree does not have it, in which case we
 121                          * fall through to report the unmerged state.
 122                          * Otherwise, we show the differences between
 123                          * the original tree and the work tree.
 124                          */
 125                         if (!cached_only && !show_modified(ce, ac[1], 0))
 126                                 break;
 127                         /* fallthru */
 128                 case 3:
 129                         if (generate_patch)
 130                                 diff_unmerge(ce->name);
 131                         else
 132                                 printf("U %s%c", ce->name, line_termination);
 133                         break;
 134
 135                 default:
 136                         die("impossible cache entry stage");
 137                 }
 138
 139                 /*
 140                  * Ignore all the different stages for this file,
 141                  * we've handled the relevant cases now.
 142                  */
 143                 do {
 144                         ac++;
 145                         entries--;
 146                 } while (entries && same_name(ce, ac[0]));
 147         }
 148         return 0;
 149 }
 150
 151 /*
 152  * This turns all merge entries into "stage 3". That guarantees that
 153  * when we read in the new tree (into "stage 1"), we won't lose sight
 154  * of the fact that we had unmerged entries.
 155  */
 156 static void mark_merge_entries(void)
 157 {
 158         int i;
 159         for (i = 0; i < active_nr; i++) {
 160                 struct cache_entry *ce = active_cache[i];
 161                 if (!ce_stage(ce))
 162                         continue;
 163                 ce->ce_flags |= htons(CE_STAGEMASK);
 164         }
 165 }
 166
 167 static char *diff_cache_usage =
 168 "diff-cache [-r] [-z] [-p] [-i] [--cached] <tree sha1>";
 169
 170 int main(int argc, char **argv)
 171 {
 172         unsigned char tree_sha1[20];
 173         void *tree;
 174         unsigned long size;
 175
 176         read_cache();
 177         while (argc > 2) {
 178                 char *arg = argv[1];
 179                 argv++;
 180                 argc--;
 181                 if (!strcmp(arg, "-r")) {
 182                         /* We accept the -r flag just to look like diff-tree */
 183                         continue;
 184                 }
 185                 if (!strcmp(arg, "-p")) {
 186                         generate_patch = 1;
 187                         continue;
 188                 }
 189                 if (!strcmp(arg, "-z")) {
 190                         line_termination = '\0';
 191                         continue;
 192                 }
 193                 if (!strcmp(arg, "-m")) {
 194                         match_nonexisting = 1;
 195                         continue;
 196                 }
 197                 if (!strcmp(arg, "--cached")) {
 198                         cached_only = 1;
 199                         continue;
 200                 }
 201                 usage(diff_cache_usage);
 202         }
 203
 204         if (argc != 2 || get_sha1(argv[1], tree_sha1))
 205                 usage(diff_cache_usage);
 206
 207         mark_merge_entries();
 208
 209         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
 210         if (!tree)
 211                 die("bad tree object %s", argv[1]);
 212         if (read_tree(tree, size, 1))
 213                 die("unable to read tree object %s", argv[1]);
 214
 215         return diff_cache(active_cache, active_nr);
 216 }