c097826719e4007122276a569db9f3732ee64f07
   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 diff_setup_opt = 0;
   9static int diff_score_opt = 0;
  10static const char *pickaxe = NULL;
  11static int pickaxe_opts = 0;
  12
  13/* A file entry went away or appeared */
  14static 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
  19static 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
  48static 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
  60static 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
  86static 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 */
 146static 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
 157static char *diff_cache_usage =
 158"git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish> [<path>...]";
 159
 160int 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}