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
  17static int nr_trees;
  18static struct tree *trees[MAX_UNPACK_TREES];
  19
  20static int list_tree(unsigned char *sha1)
  21{
  22        struct tree *tree;
  23
  24        if (nr_trees >= MAX_UNPACK_TREES)
  25                die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  26        tree = parse_tree_indirect(sha1);
  27        if (!tree)
  28                return -1;
  29        trees[nr_trees++] = tree;
  30        return 0;
  31}
  32
  33static const char * const read_tree_usage[] = {
  34        "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]]  [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]]",
  35        NULL
  36};
  37
  38static int index_output_cb(const struct option *opt, const char *arg,
  39                                 int unset)
  40{
  41        set_alternate_index_output(arg);
  42        return 0;
  43}
  44
  45static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  46                                    int unset)
  47{
  48        struct dir_struct *dir;
  49        struct unpack_trees_options *opts;
  50
  51        opts = (struct unpack_trees_options *)opt->value;
  52
  53        if (opts->dir)
  54                die("more than one --exclude-per-directory given.");
  55
  56        dir = xcalloc(1, sizeof(*opts->dir));
  57        dir->flags |= DIR_SHOW_IGNORED;
  58        dir->exclude_per_dir = arg;
  59        opts->dir = dir;
  60        /* We do not need to nor want to do read-directory
  61         * here; we are merely interested in reusing the
  62         * per directory ignore stack mechanism.
  63         */
  64        return 0;
  65}
  66
  67static struct lock_file lock_file;
  68
  69int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  70{
  71        int i, newfd, stage = 0;
  72        unsigned char sha1[20];
  73        struct tree_desc t[MAX_UNPACK_TREES];
  74        struct unpack_trees_options opts;
  75        int prefix_set = 0;
  76        const struct option read_tree_options[] = {
  77                { OPTION_CALLBACK, 0, "index-output", NULL, "FILE",
  78                  "write resulting index to <FILE>",
  79                  PARSE_OPT_NONEG, index_output_cb },
  80                OPT__VERBOSE(&opts.verbose_update),
  81                OPT_GROUP("Merging"),
  82                OPT_SET_INT('m', NULL, &opts.merge,
  83                            "perform a merge in addition to a read", 1),
  84                OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
  85                            "3-way merge if no file level merging required", 1),
  86                OPT_SET_INT(0, "aggressive", &opts.aggressive,
  87                            "3-way merge in presence of adds and removes", 1),
  88                OPT_SET_INT(0, "reset", &opts.reset,
  89                            "same as -m, but discard unmerged entries", 1),
  90                { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
  91                  "read the tree into the index under <subdirectory>/",
  92                  PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
  93                OPT_SET_INT('u', NULL, &opts.update,
  94                            "update working tree with merge result", 1),
  95                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
  96                  "gitignore",
  97                  "allow explicitly ignored files to be overwritten",
  98                  PARSE_OPT_NONEG, exclude_per_directory_cb },
  99                OPT_SET_INT('i', NULL, &opts.index_only,
 100                            "don't check the working tree after merging", 1),
 101                OPT_END()
 102        };
 103
 104        memset(&opts, 0, sizeof(opts));
 105        opts.head_idx = -1;
 106        opts.src_index = &the_index;
 107        opts.dst_index = &the_index;
 108
 109        git_config(git_default_config, NULL);
 110
 111        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 112                             read_tree_usage, 0);
 113
 114        newfd = hold_locked_index(&lock_file, 1);
 115
 116        prefix_set = opts.prefix ? 1 : 0;
 117        if (1 < opts.merge + opts.reset + prefix_set)
 118                die("Which one? -m, --reset, or --prefix?");
 119
 120        if (opts.reset || opts.merge || opts.prefix) {
 121                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 122                        die("You need to resolve your current index first");
 123                stage = opts.merge = 1;
 124        }
 125
 126        for (i = 0; i < argc; i++) {
 127                const char *arg = argv[i];
 128
 129                if (get_sha1(arg, sha1))
 130                        die("Not a valid object name %s", arg);
 131                if (list_tree(sha1) < 0)
 132                        die("failed to unpack tree object %s", arg);
 133                stage++;
 134        }
 135        if (1 < opts.index_only + opts.update)
 136                die("-u and -i at the same time makes no sense");
 137        if ((opts.update||opts.index_only) && !opts.merge)
 138                die("%s is meaningless without -m, --reset, or --prefix",
 139                    opts.update ? "-u" : "-i");
 140        if ((opts.dir && !opts.update))
 141                die("--exclude-per-directory is meaningless unless -u");
 142        if (opts.merge && !opts.index_only)
 143                setup_work_tree();
 144
 145        if (opts.merge) {
 146                if (stage < 2)
 147                        die("just how do you expect me to merge %d trees?", stage-1);
 148                switch (stage - 1) {
 149                case 1:
 150                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 151                        break;
 152                case 2:
 153                        opts.fn = twoway_merge;
 154                        opts.initial_checkout = is_cache_unborn();
 155                        break;
 156                case 3:
 157                default:
 158                        opts.fn = threeway_merge;
 159                        break;
 160                }
 161
 162                if (stage - 1 >= 3)
 163                        opts.head_idx = stage - 2;
 164                else
 165                        opts.head_idx = 1;
 166        }
 167
 168        cache_tree_free(&active_cache_tree);
 169        for (i = 0; i < nr_trees; i++) {
 170                struct tree *tree = trees[i];
 171                parse_tree(tree);
 172                init_tree_desc(t+i, tree->buffer, tree->size);
 173        }
 174        if (unpack_trees(nr_trees, t, &opts))
 175                return 128;
 176
 177        /*
 178         * When reading only one tree (either the most basic form,
 179         * "-m ent" or "--reset ent" form), we can obtain a fully
 180         * valid cache-tree because the index must match exactly
 181         * what came from the tree.
 182         *
 183         * The same holds true if we are switching between two trees
 184         * using read-tree -m A B.  The index must match B after that.
 185         */
 186        if (nr_trees == 1 && !opts.prefix)
 187                prime_cache_tree(&active_cache_tree, trees[0]);
 188        else if (nr_trees == 2 && opts.merge)
 189                prime_cache_tree(&active_cache_tree, trees[1]);
 190
 191        if (write_cache(newfd, active_cache, active_nr) ||
 192            commit_locked_index(&lock_file))
 193                die("unable to write new index file");
 194        return 0;
 195}