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)
  10 {
  11         if (generate_patch)
  12                 diff_addremove(prefix[0], ntohl(ce->ce_mode),
  13                                ce->sha1, ce->name, NULL);
  14         else
  15                 printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(ce->ce_mode),
  16                        sha1_to_hex(ce->sha1), ce->name,
  17                        line_termination);
  18 }
  19
  20 static int show_modified(struct cache_entry *old, struct cache_entry *new)
  21 {
  22         unsigned int mode = ntohl(new->ce_mode), oldmode;
  23         unsigned char *sha1 = new->sha1;
  24         unsigned char old_sha1_hex[60];
  25
  26         if (!cached_only) {
  27                 static unsigned char no_sha1[20];
  28                 int changed;
  29                 struct stat st;
  30                 if (stat(new->name, &st) < 0) {
  31                         show_file("-", old);
  32                         return -1;
  33                 }
  34                 changed = cache_match_stat(new, &st);
  35                 if (changed) {
  36                         mode = st.st_mode;
  37                         sha1 = no_sha1;
  38                 }
  39         }
  40
  41         oldmode = ntohl(old->ce_mode);
  42         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
  43                 return 0;
  44
  45         if (generate_patch)
  46                 diff_change(oldmode, mode,
  47                             old->sha1, sha1, old->name, NULL);
  48         else {
  49                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
  50                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
  51                        old_sha1_hex, sha1_to_hex(sha1),
  52                        old->name, line_termination);
  53         }
  54         return 0;
  55 }
  56
  57 static int diff_cache(struct cache_entry **ac, int entries)
  58 {
  59         while (entries) {
  60                 struct cache_entry *ce = *ac;
  61                 int same = (entries > 1) && same_name(ce, ac[1]);
  62
  63                 switch (ce_stage(ce)) {
  64                 case 0:
  65                         /* No stage 1 entry? That means it's a new file */
  66                         if (!same) {
  67                                 show_file("+", ce);
  68                                 break;
  69                         }
  70                         /* Show difference between old and new */
  71                         show_modified(ac[1], ce);
  72                         break;
  73                 case 1:
  74                         /* No stage 3 (merge) entry? That means it's been deleted */
  75                         if (!same) {
  76                                 show_file("-", ce);
  77                                 break;
  78                         }
  79                         /* Otherwise we fall through to the "unmerged" case */
  80                 case 3:
  81                         if (generate_patch)
  82                                 diff_unmerge(ce->name);
  83                         else
  84                                 printf("U %s%c", ce->name, line_termination);
  85                         break;
  86
  87                 default:
  88                         die("impossible cache entry stage");
  89                 }
  90
  91                 /*
  92                  * Ignore all the different stages for this file,
  93                  * we've handled the relevant cases now.
  94                  */
  95                 do {
  96                         ac++;
  97                         entries--;
  98                 } while (entries && same_name(ce, ac[0]));
  99         }
 100         return 0;
 101 }
 102
 103 /*
 104  * This turns all merge entries into "stage 3". That guarantees that
 105  * when we read in the new tree (into "stage 1"), we won't lose sight
 106  * of the fact that we had unmerged entries.
 107  */
 108 static void mark_merge_entries(void)
 109 {
 110         int i;
 111         for (i = 0; i < active_nr; i++) {
 112                 struct cache_entry *ce = active_cache[i];
 113                 if (!ce_stage(ce))
 114                         continue;
 115                 ce->ce_flags |= htons(CE_STAGEMASK);
 116         }
 117 }
 118
 119 static char *diff_cache_usage =
 120 "diff-cache [-r] [-z] [-p] [--cached] <tree sha1>";
 121
 122 int main(int argc, char **argv)
 123 {
 124         unsigned char tree_sha1[20];
 125         void *tree;
 126         unsigned long size;
 127
 128         read_cache();
 129         while (argc > 2) {
 130                 char *arg = argv[1];
 131                 argv++;
 132                 argc--;
 133                 if (!strcmp(arg, "-r")) {
 134                         /* We accept the -r flag just to look like diff-tree */
 135                         continue;
 136                 }
 137                 if (!strcmp(arg, "-p")) {
 138                         generate_patch = 1;
 139                         continue;
 140                 }
 141                 if (!strcmp(arg, "-z")) {
 142                         line_termination = '\0';
 143                         continue;
 144                 }
 145                 if (!strcmp(arg, "--cached")) {
 146                         cached_only = 1;
 147                         continue;
 148                 }
 149                 usage(diff_cache_usage);
 150         }
 151
 152         if (argc != 2 || get_sha1_hex(argv[1], tree_sha1))
 153                 usage(diff_cache_usage);
 154
 155         mark_merge_entries();
 156
 157         tree = read_tree_with_tree_or_commit_sha1(tree_sha1, &size, 0);
 158         if (!tree)
 159                 die("bad tree object %s", argv[1]);
 160         if (read_tree(tree, size, 1))
 161                 die("unable to read tree object %s", argv[1]);
 162
 163         return diff_cache(active_cache, active_nr);
 164 }