62b36cc8ee2bad8e4c37c4c7e2a99d6d4abc2f88
   1#include "cache.h"
   2#include "diff.h"
   3
   4static int cached_only = 0;
   5static int match_nonexisting = 0;
   6static struct diff_options diff_options;
   7
   8/* A file entry went away or appeared */
   9static void show_file(const char *prefix,
  10                      struct cache_entry *ce,
  11                      unsigned char *sha1, unsigned int mode)
  12{
  13        diff_addremove(&diff_options, prefix[0], ntohl(mode),
  14                       sha1, ce->name, NULL);
  15}
  16
  17static int get_stat_data(struct cache_entry *ce,
  18                         unsigned char **sha1p, unsigned int *modep)
  19{
  20        unsigned char *sha1 = ce->sha1;
  21        unsigned int mode = ce->ce_mode;
  22
  23        if (!cached_only) {
  24                static unsigned char no_sha1[20];
  25                int changed;
  26                struct stat st;
  27                if (lstat(ce->name, &st) < 0) {
  28                        if (errno == ENOENT && match_nonexisting) {
  29                                *sha1p = sha1;
  30                                *modep = mode;
  31                                return 0;
  32                        }
  33                        return -1;
  34                }
  35                changed = ce_match_stat(ce, &st);
  36                if (changed) {
  37                        mode = create_ce_mode(st.st_mode);
  38                        sha1 = no_sha1;
  39                }
  40        }
  41
  42        *sha1p = sha1;
  43        *modep = mode;
  44        return 0;
  45}
  46
  47static void show_new_file(struct cache_entry *new)
  48{
  49        unsigned char *sha1;
  50        unsigned int mode;
  51
  52        /* New file in the index: it might actually be different in the working copy */
  53        if (get_stat_data(new, &sha1, &mode) < 0)
  54                return;
  55
  56        show_file("+", new, sha1, mode);
  57}
  58
  59static int show_modified(struct cache_entry *old,
  60                         struct cache_entry *new,
  61                         int report_missing)
  62{
  63        unsigned int mode, oldmode;
  64        unsigned char *sha1;
  65
  66        if (get_stat_data(new, &sha1, &mode) < 0) {
  67                if (report_missing)
  68                        show_file("-", old, old->sha1, old->ce_mode);
  69                return -1;
  70        }
  71
  72        oldmode = old->ce_mode;
  73        if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  74            !diff_options.find_copies_harder)
  75                return 0;
  76
  77        mode = ntohl(mode);
  78        oldmode = ntohl(oldmode);
  79
  80        diff_change(&diff_options, oldmode, mode,
  81                    old->sha1, sha1, old->name, NULL);
  82        return 0;
  83}
  84
  85static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
  86{
  87        while (entries) {
  88                struct cache_entry *ce = *ac;
  89                int same = (entries > 1) && ce_same_name(ce, ac[1]);
  90
  91                if (!ce_path_match(ce, pathspec))
  92                        goto skip_entry;
  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(&diff_options, ce->name);
 125                        break;
 126
 127                default:
 128                        die("impossible cache entry stage");
 129                }
 130
 131skip_entry:
 132                /*
 133                 * Ignore all the different stages for this file,
 134                 * we've handled the relevant cases now.
 135                 */
 136                do {
 137                        ac++;
 138                        entries--;
 139                } while (entries && ce_same_name(ce, ac[0]));
 140        }
 141        return 0;
 142}
 143
 144/*
 145 * This turns all merge entries into "stage 3". That guarantees that
 146 * when we read in the new tree (into "stage 1"), we won't lose sight
 147 * of the fact that we had unmerged entries.
 148 */
 149static void mark_merge_entries(void)
 150{
 151        int i;
 152        for (i = 0; i < active_nr; i++) {
 153                struct cache_entry *ce = active_cache[i];
 154                if (!ce_stage(ce))
 155                        continue;
 156                ce->ce_flags |= htons(CE_STAGEMASK);
 157        }
 158}
 159
 160static const char diff_cache_usage[] =
 161"git-diff-index [-m] [--cached] "
 162"[<common diff options>] <tree-ish> [<path>...]"
 163COMMON_DIFF_OPTIONS_HELP;
 164
 165int main(int argc, const char **argv)
 166{
 167        const char *tree_name = NULL;
 168        unsigned char sha1[20];
 169        const char *prefix = setup_git_directory();
 170        const char **pathspec = NULL;
 171        void *tree;
 172        unsigned long size;
 173        int ret;
 174        int allow_options = 1;
 175        int i;
 176
 177        diff_setup(&diff_options);
 178        for (i = 1; i < argc; i++) {
 179                const char *arg = argv[i];
 180                int diff_opt_cnt;
 181
 182                if (!allow_options || *arg != '-') {
 183                        if (tree_name)
 184                                break;
 185                        tree_name = arg;
 186                        continue;
 187                }
 188                        
 189                if (!strcmp(arg, "--")) {
 190                        allow_options = 0;
 191                        continue;
 192                }
 193                if (!strcmp(arg, "-r")) {
 194                        /* We accept the -r flag just to look like git-diff-tree */
 195                        continue;
 196                }
 197                diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
 198                                              argc - i);
 199                if (diff_opt_cnt < 0)
 200                        usage(diff_cache_usage);
 201                else if (diff_opt_cnt) {
 202                        i += diff_opt_cnt - 1;
 203                        continue;
 204                }
 205
 206                if (!strcmp(arg, "-m")) {
 207                        match_nonexisting = 1;
 208                        continue;
 209                }
 210                if (!strcmp(arg, "--cached")) {
 211                        cached_only = 1;
 212                        continue;
 213                }
 214                usage(diff_cache_usage);
 215        }
 216
 217        pathspec = get_pathspec(prefix, argv + i);
 218
 219        if (diff_setup_done(&diff_options) < 0)
 220                usage(diff_cache_usage);
 221
 222        if (!tree_name || get_sha1(tree_name, sha1))
 223                usage(diff_cache_usage);
 224
 225        read_cache();
 226
 227        mark_merge_entries();
 228
 229        tree = read_object_with_reference(sha1, "tree", &size, NULL);
 230        if (!tree)
 231                die("bad tree object %s", tree_name);
 232        if (read_tree(tree, size, 1, pathspec))
 233                die("unable to read tree object %s", tree_name);
 234
 235        ret = diff_cache(active_cache, active_nr, pathspec);
 236
 237        diffcore_std(&diff_options);
 238        diff_flush(&diff_options);
 239        return ret;
 240}