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