diff-cache.c

   1 #include "cache.h"
   2 #include "diff.h"
   3
   4 static int cached_only = 0;
   5 static int diff_output_format = DIFF_FORMAT_HUMAN;
   6 static int match_nonexisting = 0;
   7 static int detect_rename = 0;
   8 static int diff_setup_opt = 0;
   9 static int diff_score_opt = 0;
  10 static const char *pickaxe = NULL;
  11 static int pickaxe_opts = 0;
  12 static int diff_break_opt = -1;
  13
  14 /* A file entry went away or appeared */
  15 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  16 {
  17         diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  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
  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             detect_rename < DIFF_DETECT_COPY)
  77                 return 0;
  78
  79         mode = ntohl(mode);
  80         oldmode = ntohl(oldmode);
  81
  82         diff_change(oldmode, mode,
  83                     old->sha1, sha1, old->name, NULL);
  84         return 0;
  85 }
  86
  87 static int diff_cache(struct cache_entry **ac, int entries)
  88 {
  89         while (entries) {
  90                 struct cache_entry *ce = *ac;
  91                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  92
  93                 switch (ce_stage(ce)) {
  94                 case 0:
  95                         /* No stage 1 entry? That means it's a new file */
  96                         if (!same) {
  97                                 show_new_file(ce);
  98                                 break;
  99                         }
 100                         /* Show difference between old and new */
 101                         show_modified(ac[1], ce, 1);
 102                         break;
 103                 case 1:
 104                         /* No stage 3 (merge) entry? That means it's been deleted */
 105                         if (!same) {
 106                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 107                                 break;
 108                         }
 109                         /* We come here with ce pointing at stage 1
 110                          * (original tree) and ac[1] pointing at stage
 111                          * 3 (unmerged).  show-modified with
 112                          * report-mising set to false does not say the
 113                          * file is deleted but reports true if work
 114                          * tree does not have it, in which case we
 115                          * fall through to report the unmerged state.
 116                          * Otherwise, we show the differences between
 117                          * the original tree and the work tree.
 118                          */
 119                         if (!cached_only && !show_modified(ce, ac[1], 0))
 120                                 break;
 121                         /* fallthru */
 122                 case 3:
 123                         diff_unmerge(ce->name);
 124                         break;
 125
 126                 default:
 127                         die("impossible cache entry stage");
 128                 }
 129
 130                 /*
 131                  * Ignore all the different stages for this file,
 132                  * we've handled the relevant cases now.
 133                  */
 134                 do {
 135                         ac++;
 136                         entries--;
 137                 } while (entries && ce_same_name(ce, ac[0]));
 138         }
 139         return 0;
 140 }
 141
 142 /*
 143  * This turns all merge entries into "stage 3". That guarantees that
 144  * when we read in the new tree (into "stage 1"), we won't lose sight
 145  * of the fact that we had unmerged entries.
 146  */
 147 static void mark_merge_entries(void)
 148 {
 149         int i;
 150         for (i = 0; i < active_nr; i++) {
 151                 struct cache_entry *ce = active_cache[i];
 152                 if (!ce_stage(ce))
 153                         continue;
 154                 ce->ce_flags |= htons(CE_STAGEMASK);
 155         }
 156 }
 157
 158 static char *diff_cache_usage =
 159 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish> [<path>...]";
 160
 161 int main(int argc, const char **argv)
 162 {
 163         const char *tree_name = NULL;
 164         unsigned char sha1[20];
 165         const char **pathspec = NULL;
 166         void *tree;
 167         unsigned long size;
 168         int ret;
 169         int i;
 170
 171         read_cache();
 172         for (i = 1; i < argc; i++) {
 173                 const char *arg = argv[i];
 174
 175                 if (*arg != '-') {
 176                         if (tree_name) {
 177                                 pathspec = argv + i;
 178                                 break;
 179                         }
 180                         tree_name = arg;
 181                         continue;
 182                 }
 183
 184                 if (!strcmp(arg, "-r")) {
 185                         /* We accept the -r flag just to look like git-diff-tree */
 186                         continue;
 187                 }
 188                 if (!strcmp(arg, "-p")) {
 189                         diff_output_format = DIFF_FORMAT_PATCH;
 190                         continue;
 191                 }
 192                 if (!strncmp(arg, "-B", 2)) {
 193                         diff_break_opt = diff_scoreopt_parse(arg);
 194                         continue;
 195                 }
 196                 if (!strncmp(arg, "-M", 2)) {
 197                         detect_rename = DIFF_DETECT_RENAME;
 198                         diff_score_opt = diff_scoreopt_parse(arg);
 199                         continue;
 200                 }
 201                 if (!strncmp(arg, "-C", 2)) {
 202                         detect_rename = DIFF_DETECT_COPY;
 203                         diff_score_opt = diff_scoreopt_parse(arg);
 204                         continue;
 205                 }
 206                 if (!strcmp(arg, "-z")) {
 207                         diff_output_format = DIFF_FORMAT_MACHINE;
 208                         continue;
 209                 }
 210                 if (!strcmp(arg, "-R")) {
 211                         diff_setup_opt |= DIFF_SETUP_REVERSE;
 212                         continue;
 213                 }
 214                 if (!strncmp(arg, "-S", 2)) {
 215                         pickaxe = arg + 2;
 216                         continue;
 217                 }
 218                 if (!strcmp(arg, "--pickaxe-all")) {
 219                         pickaxe_opts = DIFF_PICKAXE_ALL;
 220                         continue;
 221                 }
 222                 if (!strcmp(arg, "-m")) {
 223                         match_nonexisting = 1;
 224                         continue;
 225                 }
 226                 if (!strcmp(arg, "--cached")) {
 227                         cached_only = 1;
 228                         continue;
 229                 }
 230                 usage(diff_cache_usage);
 231         }
 232
 233         if (!tree_name || get_sha1(tree_name, sha1))
 234                 usage(diff_cache_usage);
 235
 236         /* The rest is for paths restriction. */
 237         diff_setup(diff_setup_opt);
 238
 239         mark_merge_entries();
 240
 241         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 242         if (!tree)
 243                 die("bad tree object %s", tree_name);
 244         if (read_tree(tree, size, 1))
 245                 die("unable to read tree object %s", tree_name);
 246
 247         ret = diff_cache(active_cache, active_nr);
 248
 249         diffcore_std(pathspec ? : NULL,
 250                      detect_rename, diff_score_opt,
 251                      pickaxe, pickaxe_opts,
 252                      diff_break_opt);
 253         diff_flush(diff_output_format, 1);
 254         return ret;
 255 }