be9222288fb6a6ecfdd4c91f6e386e9baf1c8f60
   1#include "cache.h"
   2#include "diff.h"
   3
   4static int cached_only = 0;
   5static int diff_output_format = DIFF_FORMAT_HUMAN;
   6static int match_nonexisting = 0;
   7static int detect_rename = 0;
   8static int find_copies_harder = 0;
   9static int diff_setup_opt = 0;
  10static int diff_score_opt = 0;
  11static const char *pickaxe = NULL;
  12static int pickaxe_opts = 0;
  13static int diff_break_opt = -1;
  14static const char *orderfile = NULL;
  15static const char *diff_filter = NULL;
  16
  17/* A file entry went away or appeared */
  18static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
  19{
  20        diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
  21}
  22
  23static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
  24{
  25        unsigned char *sha1 = ce->sha1;
  26        unsigned int mode = ce->ce_mode;
  27
  28        if (!cached_only) {
  29                static unsigned char no_sha1[20];
  30                int changed;
  31                struct stat st;
  32                if (lstat(ce->name, &st) < 0) {
  33                        if (errno == ENOENT && match_nonexisting) {
  34                                *sha1p = sha1;
  35                                *modep = mode;
  36                                return 0;
  37                        }
  38                        return -1;
  39                }
  40                changed = ce_match_stat(ce, &st);
  41                if (changed) {
  42                        mode = create_ce_mode(st.st_mode);
  43                        sha1 = no_sha1;
  44                }
  45        }
  46
  47        *sha1p = sha1;
  48        *modep = mode;
  49        return 0;
  50}
  51
  52static void show_new_file(struct cache_entry *new)
  53{
  54        unsigned char *sha1;
  55        unsigned int mode;
  56
  57        /* New file in the index: it might actually be different in the working copy */
  58        if (get_stat_data(new, &sha1, &mode) < 0)
  59                return;
  60
  61        show_file("+", new, sha1, mode);
  62}
  63
  64static int show_modified(struct cache_entry *old,
  65                         struct cache_entry *new,
  66                         int report_missing)
  67{
  68        unsigned int mode, oldmode;
  69        unsigned char *sha1;
  70
  71        if (get_stat_data(new, &sha1, &mode) < 0) {
  72                if (report_missing)
  73                        show_file("-", old, old->sha1, old->ce_mode);
  74                return -1;
  75        }
  76
  77        oldmode = old->ce_mode;
  78        if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
  79            !find_copies_harder)
  80                return 0;
  81
  82        mode = ntohl(mode);
  83        oldmode = ntohl(oldmode);
  84
  85        diff_change(oldmode, mode,
  86                    old->sha1, sha1, old->name, NULL);
  87        return 0;
  88}
  89
  90static int diff_cache(struct cache_entry **ac, int entries)
  91{
  92        while (entries) {
  93                struct cache_entry *ce = *ac;
  94                int same = (entries > 1) && ce_same_name(ce, ac[1]);
  95
  96                switch (ce_stage(ce)) {
  97                case 0:
  98                        /* No stage 1 entry? That means it's a new file */
  99                        if (!same) {
 100                                show_new_file(ce);
 101                                break;
 102                        }
 103                        /* Show difference between old and new */
 104                        show_modified(ac[1], ce, 1);
 105                        break;
 106                case 1:
 107                        /* No stage 3 (merge) entry? That means it's been deleted */
 108                        if (!same) {
 109                                show_file("-", ce, ce->sha1, ce->ce_mode);
 110                                break;
 111                        }
 112                        /* We come here with ce pointing at stage 1
 113                         * (original tree) and ac[1] pointing at stage
 114                         * 3 (unmerged).  show-modified with
 115                         * report-mising set to false does not say the
 116                         * file is deleted but reports true if work
 117                         * tree does not have it, in which case we
 118                         * fall through to report the unmerged state.
 119                         * Otherwise, we show the differences between
 120                         * the original tree and the work tree.
 121                         */
 122                        if (!cached_only && !show_modified(ce, ac[1], 0))
 123                                break;
 124                        /* fallthru */
 125                case 3:
 126                        diff_unmerge(ce->name);
 127                        break;
 128
 129                default:
 130                        die("impossible cache entry stage");
 131                }
 132
 133                /*
 134                 * Ignore all the different stages for this file,
 135                 * we've handled the relevant cases now.
 136                 */
 137                do {
 138                        ac++;
 139                        entries--;
 140                } while (entries && ce_same_name(ce, ac[0]));
 141        }
 142        return 0;
 143}
 144
 145/*
 146 * This turns all merge entries into "stage 3". That guarantees that
 147 * when we read in the new tree (into "stage 1"), we won't lose sight
 148 * of the fact that we had unmerged entries.
 149 */
 150static void mark_merge_entries(void)
 151{
 152        int i;
 153        for (i = 0; i < active_nr; i++) {
 154                struct cache_entry *ce = active_cache[i];
 155                if (!ce_stage(ce))
 156                        continue;
 157                ce->ce_flags |= htons(CE_STAGEMASK);
 158        }
 159}
 160
 161static char *diff_cache_usage =
 162"git-diff-cache [-m] [--cached] "
 163"[<common diff options>] <tree-ish> [<path>...]"
 164COMMON_DIFF_OPTIONS_HELP;
 165
 166int main(int argc, const char **argv)
 167{
 168        const char *tree_name = NULL;
 169        unsigned char sha1[20];
 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        read_cache();
 178        for (i = 1; i < argc; i++) {
 179                const char *arg = argv[i];
 180
 181                if (!allow_options || *arg != '-') {
 182                        if (tree_name) {
 183                                pathspec = argv + i;
 184                                break;
 185                        }
 186                        tree_name = arg;
 187                        continue;
 188                }
 189                        
 190                if (!strcmp(arg, "--")) {
 191                        allow_options = 0;
 192                        continue;
 193                }
 194                if (!strcmp(arg, "-r")) {
 195                        /* We accept the -r flag just to look like git-diff-tree */
 196                        continue;
 197                }
 198                /* We accept the -u flag as a synonym for "-p" */
 199                if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
 200                        diff_output_format = DIFF_FORMAT_PATCH;
 201                        continue;
 202                }
 203                if (!strncmp(arg, "-B", 2)) {
 204                        if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
 205                                usage(diff_cache_usage);
 206                        continue;
 207                }
 208                if (!strncmp(arg, "-M", 2)) {
 209                        detect_rename = DIFF_DETECT_RENAME;
 210                        if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 211                                usage(diff_cache_usage);
 212                        continue;
 213                }
 214                if (!strncmp(arg, "-C", 2)) {
 215                        detect_rename = DIFF_DETECT_COPY;
 216                        if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
 217                                usage(diff_cache_usage);
 218                        continue;
 219                }
 220                if (!strcmp(arg, "--find-copies-harder")) {
 221                        find_copies_harder = 1;
 222                        continue;
 223                }
 224                if (!strcmp(arg, "-z")) {
 225                        diff_output_format = DIFF_FORMAT_MACHINE;
 226                        continue;
 227                }
 228                if (!strcmp(arg, "--name-only")) {
 229                        diff_output_format = DIFF_FORMAT_NAME;
 230                        continue;
 231                }
 232                if (!strcmp(arg, "--name-only-z")) {
 233                        diff_output_format = DIFF_FORMAT_NAME_Z;
 234                        continue;
 235                }
 236                if (!strcmp(arg, "-R")) {
 237                        diff_setup_opt |= DIFF_SETUP_REVERSE;
 238                        continue;
 239                }
 240                if (!strncmp(arg, "-S", 2)) {
 241                        pickaxe = arg + 2;
 242                        continue;
 243                }
 244                if (!strncmp(arg, "--diff-filter=", 14)) {
 245                        diff_filter = arg + 14;
 246                        continue;
 247                }
 248                if (!strncmp(arg, "-O", 2)) {
 249                        orderfile = arg + 2;
 250                        continue;
 251                }
 252                if (!strcmp(arg, "--pickaxe-all")) {
 253                        pickaxe_opts = DIFF_PICKAXE_ALL;
 254                        continue;
 255                }
 256                if (!strcmp(arg, "-m")) {
 257                        match_nonexisting = 1;
 258                        continue;
 259                }
 260                if (!strcmp(arg, "--cached")) {
 261                        cached_only = 1;
 262                        continue;
 263                }
 264                usage(diff_cache_usage);
 265        }
 266
 267        if (find_copies_harder && detect_rename != DIFF_DETECT_COPY)
 268                usage(diff_cache_usage);
 269
 270        if (!tree_name || get_sha1(tree_name, sha1))
 271                usage(diff_cache_usage);
 272
 273        /* The rest is for paths restriction. */
 274        diff_setup(diff_setup_opt);
 275
 276        mark_merge_entries();
 277
 278        tree = read_object_with_reference(sha1, "tree", &size, NULL);
 279        if (!tree)
 280                die("bad tree object %s", tree_name);
 281        if (read_tree(tree, size, 1, pathspec))
 282                die("unable to read tree object %s", tree_name);
 283
 284        ret = diff_cache(active_cache, active_nr);
 285
 286        diffcore_std(pathspec,
 287                     detect_rename, diff_score_opt,
 288                     pickaxe, pickaxe_opts,
 289                     diff_break_opt,
 290                     orderfile, diff_filter);
 291        diff_flush(diff_output_format);
 292        return ret;
 293}