Andrew's git - gitweb.git/blob - builtin/read-tree.c

   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6
   7#include "cache.h"
   8#include "lockfile.h"
   9#include "object.h"
  10#include "tree.h"
  11#include "tree-walk.h"
  12#include "cache-tree.h"
  13#include "unpack-trees.h"
  14#include "dir.h"
  15#include "builtin.h"
  16#include "parse-options.h"
  17#include "resolve-undo.h"
  18
  19static int nr_trees;
  20static int read_empty;
  21static struct tree *trees[MAX_UNPACK_TREES];
  22
  23static int list_tree(unsigned char *sha1)
  24{
  25        struct tree *tree;
  26
  27        if (nr_trees >= MAX_UNPACK_TREES)
  28                die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  29        tree = parse_tree_indirect(sha1);
  30        if (!tree)
  31                return -1;
  32        trees[nr_trees++] = tree;
  33        return 0;
  34}
  35
  36static const char * const read_tree_usage[] = {
  37        N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>) [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  38        NULL
  39};
  40
  41static int index_output_cb(const struct option *opt, const char *arg,
  42                                 int unset)
  43{
  44        set_alternate_index_output(arg);
  45        return 0;
  46}
  47
  48static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  49                                    int unset)
  50{
  51        struct dir_struct *dir;
  52        struct unpack_trees_options *opts;
  53
  54        opts = (struct unpack_trees_options *)opt->value;
  55
  56        if (opts->dir)
  57                die("more than one --exclude-per-directory given.");
  58
  59        dir = xcalloc(1, sizeof(*opts->dir));
  60        dir->flags |= DIR_SHOW_IGNORED;
  61        dir->exclude_per_dir = arg;
  62        opts->dir = dir;
  63        /* We do not need to nor want to do read-directory
  64         * here; we are merely interested in reusing the
  65         * per directory ignore stack mechanism.
  66         */
  67        return 0;
  68}
  69
  70static void debug_stage(const char *label, const struct cache_entry *ce,
  71                        struct unpack_trees_options *o)
  72{
  73        printf("%s ", label);
  74        if (!ce)
  75                printf("(missing)\n");
  76        else if (ce == o->df_conflict_entry)
  77                printf("(conflict)\n");
  78        else
  79                printf("%06o #%d %s %.8s\n",
  80                       ce->ce_mode, ce_stage(ce), ce->name,
  81                       sha1_to_hex(ce->sha1));
  82}
  83
  84static int debug_merge(const struct cache_entry * const *stages,
  85                       struct unpack_trees_options *o)
  86{
  87        int i;
  88
  89        printf("* %d-way merge\n", o->merge_size);
  90        debug_stage("index", stages[0], o);
  91        for (i = 1; i <= o->merge_size; i++) {
  92                char buf[24];
  93                xsnprintf(buf, sizeof(buf), "ent#%d", i);
  94                debug_stage(buf, stages[i], o);
  95        }
  96        return 0;
  97}
  98
  99static struct lock_file lock_file;
 100
 101int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 102{
 103        int i, stage = 0;
 104        unsigned char sha1[20];
 105        struct tree_desc t[MAX_UNPACK_TREES];
 106        struct unpack_trees_options opts;
 107        int prefix_set = 0;
 108        const struct option read_tree_options[] = {
 109                { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 110                  N_("write resulting index to <file>"),
 111                  PARSE_OPT_NONEG, index_output_cb },
 112                OPT_SET_INT(0, "empty", &read_empty,
 113                            N_("only empty the index"), 1),
 114                OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 115                OPT_GROUP(N_("Merging")),
 116                OPT_SET_INT('m', NULL, &opts.merge,
 117                            N_("perform a merge in addition to a read"), 1),
 118                OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
 119                            N_("3-way merge if no file level merging required"), 1),
 120                OPT_SET_INT(0, "aggressive", &opts.aggressive,
 121                            N_("3-way merge in presence of adds and removes"), 1),
 122                OPT_SET_INT(0, "reset", &opts.reset,
 123                            N_("same as -m, but discard unmerged entries"), 1),
 124                { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 125                  N_("read the tree into the index under <subdirectory>/"),
 126                  PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 127                OPT_SET_INT('u', NULL, &opts.update,
 128                            N_("update working tree with merge result"), 1),
 129                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 130                  N_("gitignore"),
 131                  N_("allow explicitly ignored files to be overwritten"),
 132                  PARSE_OPT_NONEG, exclude_per_directory_cb },
 133                OPT_SET_INT('i', NULL, &opts.index_only,
 134                            N_("don't check the working tree after merging"), 1),
 135                OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 136                OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 137                            N_("skip applying sparse checkout filter"), 1),
 138                OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
 139                            N_("debug unpack-trees"), 1),
 140                OPT_END()
 141        };
 142
 143        memset(&opts, 0, sizeof(opts));
 144        opts.head_idx = -1;
 145        opts.src_index = &the_index;
 146        opts.dst_index = &the_index;
 147
 148        git_config(git_default_config, NULL);
 149
 150        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 151                             read_tree_usage, 0);
 152
 153        hold_locked_index(&lock_file, 1);
 154
 155        prefix_set = opts.prefix ? 1 : 0;
 156        if (1 < opts.merge + opts.reset + prefix_set)
 157                die("Which one? -m, --reset, or --prefix?");
 158
 159        /*
 160         * NEEDSWORK
 161         *
 162         * The old index should be read anyway even if we're going to
 163         * destroy all index entries because we still need to preserve
 164         * certain information such as index version or split-index
 165         * mode.
 166         */
 167
 168        if (opts.reset || opts.merge || opts.prefix) {
 169                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 170                        die("You need to resolve your current index first");
 171                stage = opts.merge = 1;
 172        }
 173        resolve_undo_clear();
 174
 175        for (i = 0; i < argc; i++) {
 176                const char *arg = argv[i];
 177
 178                if (get_sha1(arg, sha1))
 179                        die("Not a valid object name %s", arg);
 180                if (list_tree(sha1) < 0)
 181                        die("failed to unpack tree object %s", arg);
 182                stage++;
 183        }
 184        if (nr_trees == 0 && !read_empty)
 185                warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 186        else if (nr_trees > 0 && read_empty)
 187                die("passing trees as arguments contradicts --empty");
 188
 189        if (1 < opts.index_only + opts.update)
 190                die("-u and -i at the same time makes no sense");
 191        if ((opts.update || opts.index_only) && !opts.merge)
 192                die("%s is meaningless without -m, --reset, or --prefix",
 193                    opts.update ? "-u" : "-i");
 194        if ((opts.dir && !opts.update))
 195                die("--exclude-per-directory is meaningless unless -u");
 196        if (opts.merge && !opts.index_only)
 197                setup_work_tree();
 198
 199        if (opts.merge) {
 200                if (stage < 2)
 201                        die("just how do you expect me to merge %d trees?", stage-1);
 202                switch (stage - 1) {
 203                case 1:
 204                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 205                        break;
 206                case 2:
 207                        opts.fn = twoway_merge;
 208                        opts.initial_checkout = is_cache_unborn();
 209                        break;
 210                case 3:
 211                default:
 212                        opts.fn = threeway_merge;
 213                        break;
 214                }
 215
 216                if (stage - 1 >= 3)
 217                        opts.head_idx = stage - 2;
 218                else
 219                        opts.head_idx = 1;
 220        }
 221
 222        if (opts.debug_unpack)
 223                opts.fn = debug_merge;
 224
 225        cache_tree_free(&active_cache_tree);
 226        for (i = 0; i < nr_trees; i++) {
 227                struct tree *tree = trees[i];
 228                parse_tree(tree);
 229                init_tree_desc(t+i, tree->buffer, tree->size);
 230        }
 231        if (unpack_trees(nr_trees, t, &opts))
 232                return 128;
 233
 234        if (opts.debug_unpack || opts.dry_run)
 235                return 0; /* do not write the index out */
 236
 237        /*
 238         * When reading only one tree (either the most basic form,
 239         * "-m ent" or "--reset ent" form), we can obtain a fully
 240         * valid cache-tree because the index must match exactly
 241         * what came from the tree.
 242         */
 243        if (nr_trees == 1 && !opts.prefix)
 244                prime_cache_tree(&the_index, trees[0]);
 245
 246        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 247                die("unable to write new index file");
 248        return 0;
 249}