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