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 static const char *orderfile = NULL;
  14
  15 /* A file entry went away or appeared */
  16 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  17 {
  18         diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  19 }
  20
  21 static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
  22 {
  23         unsigned char *sha1 = ce->sha1;
  24         unsigned int mode = ce->ce_mode;
  25
  26         if (!cached_only) {
  27                 static unsigned char no_sha1[20];
  28                 int changed;
  29                 struct stat st;
  30                 if (lstat(ce->name, &st) < 0) {
  31                         if (errno == ENOENT && match_nonexisting) {
  32                                 *sha1p = sha1;
  33                                 *modep = mode;
  34                                 return 0;
  35                         }
  36                         return -1;
  37                 }
  38                 changed = ce_match_stat(ce, &st);
  39                 if (changed) {
  40                         mode = create_ce_mode(st.st_mode);
  41                         sha1 = no_sha1;
  42                 }
  43         }
  44
  45         *sha1p = sha1;
  46         *modep = mode;
  47         return 0;
  48 }
  49
  50 static void show_new_file(struct cache_entry *new)
  51 {
  52         unsigned char *sha1;
  53         unsigned int mode;
  54
  55         /* New file in the index: it might actually be different in the working copy */
  56         if (get_stat_data(new, &sha1, &mode) < 0)
  57                 return;
  58
  59         show_file("+", new, sha1, mode);
  60 }
  61
  62 static int show_modified(struct cache_entry *old,
  63                          struct cache_entry *new,
  64                          int report_missing)
  65 {
  66         unsigned int mode, oldmode;
  67         unsigned char *sha1;
  68
  69         if (get_stat_data(new, &sha1, &mode) < 0) {
  70                 if (report_missing)
  71                         show_file("-", old, old->sha1, old->ce_mode);
  72                 return -1;
  73         }
  74
  75         oldmode = old->ce_mode;
  76         if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  77             detect_rename < DIFF_DETECT_COPY)
  78                 return 0;
  79
  80         mode = ntohl(mode);
  81         oldmode = ntohl(oldmode);
  82
  83         diff_change(oldmode, mode,
  84                     old->sha1, sha1, old->name, NULL);
  85         return 0;
  86 }
  87
  88 static int diff_cache(struct cache_entry **ac, int entries)
  89 {
  90         while (entries) {
  91                 struct cache_entry *ce = *ac;
  92                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
  93
  94                 switch (ce_stage(ce)) {
  95                 case 0:
  96                         /* No stage 1 entry? That means it's a new file */
  97                         if (!same) {
  98                                 show_new_file(ce);
  99                                 break;
 100                         }
 101                         /* Show difference between old and new */
 102                         show_modified(ac[1], ce, 1);
 103                         break;
 104                 case 1:
 105                         /* No stage 3 (merge) entry? That means it's been deleted */
 106                         if (!same) {
 107                                 show_file("-", ce, ce->sha1, ce->ce_mode);
 108                                 break;
 109                         }
 110                         /* We come here with ce pointing at stage 1
 111                          * (original tree) and ac[1] pointing at stage
 112                          * 3 (unmerged).  show-modified with
 113                          * report-mising set to false does not say the
 114                          * file is deleted but reports true if work
 115                          * tree does not have it, in which case we
 116                          * fall through to report the unmerged state.
 117                          * Otherwise, we show the differences between
 118                          * the original tree and the work tree.
 119                          */
 120                         if (!cached_only && !show_modified(ce, ac[1], 0))
 121                                 break;
 122                         /* fallthru */
 123                 case 3:
 124                         diff_unmerge(ce->name);
 125                         break;
 126
 127                 default:
 128                         die("impossible cache entry stage");
 129                 }
 130
 131                 /*
 132                  * Ignore all the different stages for this file,
 133                  * we've handled the relevant cases now.
 134                  */
 135                 do {
 136                         ac++;
 137                         entries--;
 138                 } while (entries && ce_same_name(ce, ac[0]));
 139         }
 140         return 0;
 141 }
 142
 143 /*
 144  * This turns all merge entries into "stage 3". That guarantees that
 145  * when we read in the new tree (into "stage 1"), we won't lose sight
 146  * of the fact that we had unmerged entries.
 147  */
 148 static void mark_merge_entries(void)
 149 {
 150         int i;
 151         for (i = 0; i < active_nr; i++) {
 152                 struct cache_entry *ce = active_cache[i];
 153                 if (!ce_stage(ce))
 154                         continue;
 155                 ce->ce_flags |= htons(CE_STAGEMASK);
 156         }
 157 }
 158
 159 static char *diff_cache_usage =
 160 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [-O<orderfile>] [--cached] <tree-ish> [<path>...]";
 161
 162 int main(int argc, const char **argv)
 163 {
 164         const char *tree_name = NULL;
 165         unsigned char sha1[20];
 166         const char **pathspec = NULL;
 167         void *tree;
 168         unsigned long size;
 169         int ret;
 170         int allow_options = 1;
 171         int i;
 172
 173         read_cache();
 174         for (i = 1; i < argc; i++) {
 175                 const char *arg = argv[i];
 176
 177                 if (!allow_options || *arg != '-') {
 178                         if (tree_name) {
 179                                 pathspec = argv + i;
 180                                 break;
 181                         }
 182                         tree_name = arg;
 183                         continue;
 184                 }
 185
 186                 if (!strcmp(arg, "--")) {
 187                         allow_options = 0;
 188                         continue;
 189                 }
 190                 if (!strcmp(arg, "-r")) {
 191                         /* We accept the -r flag just to look like git-diff-tree */
 192                         continue;
 193                 }
 194                 if (!strcmp(arg, "-p")) {
 195                         diff_output_format = DIFF_FORMAT_PATCH;
 196                         continue;
 197                 }
 198                 if (!strncmp(arg, "-B", 2)) {
 199                         if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
 200                                 usage(diff_cache_usage);
 201                         continue;
 202                 }
 203                 if (!strncmp(arg, "-M", 2)) {
 204                         detect_rename = DIFF_DETECT_RENAME;
 205                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 206                                 usage(diff_cache_usage);
 207                         continue;
 208                 }
 209                 if (!strncmp(arg, "-C", 2)) {
 210                         detect_rename = DIFF_DETECT_COPY;
 211                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 212                                 usage(diff_cache_usage);
 213                         continue;
 214                 }
 215                 if (!strcmp(arg, "-z")) {
 216                         diff_output_format = DIFF_FORMAT_MACHINE;
 217                         continue;
 218                 }
 219                 if (!strcmp(arg, "-R")) {
 220                         diff_setup_opt |= DIFF_SETUP_REVERSE;
 221                         continue;
 222                 }
 223                 if (!strncmp(arg, "-S", 2)) {
 224                         pickaxe = arg + 2;
 225                         continue;
 226                 }
 227                 if (!strncmp(arg, "-O", 2)) {
 228                         orderfile = arg + 2;
 229                         continue;
 230                 }
 231                 if (!strcmp(arg, "--pickaxe-all")) {
 232                         pickaxe_opts = DIFF_PICKAXE_ALL;
 233                         continue;
 234                 }
 235                 if (!strcmp(arg, "-m")) {
 236                         match_nonexisting = 1;
 237                         continue;
 238                 }
 239                 if (!strcmp(arg, "--cached")) {
 240                         cached_only = 1;
 241                         continue;
 242                 }
 243                 usage(diff_cache_usage);
 244         }
 245
 246         if (!tree_name || get_sha1(tree_name, sha1))
 247                 usage(diff_cache_usage);
 248
 249         /* The rest is for paths restriction. */
 250         diff_setup(diff_setup_opt);
 251
 252         mark_merge_entries();
 253
 254         tree = read_object_with_reference(sha1, "tree", &size, NULL);
 255         if (!tree)
 256                 die("bad tree object %s", tree_name);
 257         if (read_tree(tree, size, 1))
 258                 die("unable to read tree object %s", tree_name);
 259
 260         ret = diff_cache(active_cache, active_nr);
 261
 262         diffcore_std(pathspec ? : NULL,
 263                      detect_rename, diff_score_opt,
 264                      pickaxe, pickaxe_opts,
 265                      diff_break_opt,
 266                      orderfile);
 267         diff_flush(diff_output_format, 1);
 268         return ret;
 269 }