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