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        "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, 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(struct cache_entry **stages, struct unpack_trees_options *o)
  84{
  85        int i;
  86
  87        printf("* %d-way merge\n", o->merge_size);
  88        debug_stage("index", stages[0], o);
  89        for (i = 1; i <= o->merge_size; i++) {
  90                char buf[24];
  91                sprintf(buf, "ent#%d", i);
  92                debug_stage(buf, stages[i], o);
  93        }
  94        return 0;
  95}
  96
  97static struct lock_file lock_file;
  98
  99int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 100{
 101        int i, newfd, stage = 0;
 102        unsigned char sha1[20];
 103        struct tree_desc t[MAX_UNPACK_TREES];
 104        struct unpack_trees_options opts;
 105        int prefix_set = 0;
 106        const struct option read_tree_options[] = {
 107                { OPTION_CALLBACK, 0, "index-output", NULL, "file",
 108                  "write resulting index to <file>",
 109                  PARSE_OPT_NONEG, index_output_cb },
 110                OPT_SET_INT(0, "empty", &read_empty,
 111                            "only empty the index", 1),
 112                OPT__VERBOSE(&opts.verbose_update, "be verbose"),
 113                OPT_GROUP("Merging"),
 114                OPT_SET_INT('m', NULL, &opts.merge,
 115                            "perform a merge in addition to a read", 1),
 116                OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
 117                            "3-way merge if no file level merging required", 1),
 118                OPT_SET_INT(0, "aggressive", &opts.aggressive,
 119                            "3-way merge in presence of adds and removes", 1),
 120                OPT_SET_INT(0, "reset", &opts.reset,
 121                            "same as -m, but discard unmerged entries", 1),
 122                { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
 123                  "read the tree into the index under <subdirectory>/",
 124                  PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 125                OPT_SET_INT('u', NULL, &opts.update,
 126                            "update working tree with merge result", 1),
 127                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 128                  "gitignore",
 129                  "allow explicitly ignored files to be overwritten",
 130                  PARSE_OPT_NONEG, exclude_per_directory_cb },
 131                OPT_SET_INT('i', NULL, &opts.index_only,
 132                            "don't check the working tree after merging", 1),
 133                OPT__DRY_RUN(&opts.dry_run, "don't update the index or the work tree"),
 134                OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 135                            "skip applying sparse checkout filter", 1),
 136                OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
 137                            "debug unpack-trees", 1),
 138                OPT_END()
 139        };
 140
 141        memset(&opts, 0, sizeof(opts));
 142        opts.head_idx = -1;
 143        opts.src_index = &the_index;
 144        opts.dst_index = &the_index;
 145
 146        git_config(git_default_config, NULL);
 147
 148        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 149                             read_tree_usage, 0);
 150
 151        newfd = hold_locked_index(&lock_file, 1);
 152
 153        prefix_set = opts.prefix ? 1 : 0;
 154        if (1 < opts.merge + opts.reset + prefix_set)
 155                die("Which one? -m, --reset, or --prefix?");
 156
 157        if (opts.reset || opts.merge || opts.prefix) {
 158                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 159                        die("You need to resolve your current index first");
 160                stage = opts.merge = 1;
 161        }
 162        resolve_undo_clear();
 163
 164        for (i = 0; i < argc; i++) {
 165                const char *arg = argv[i];
 166
 167                if (get_sha1(arg, sha1))
 168                        die("Not a valid object name %s", arg);
 169                if (list_tree(sha1) < 0)
 170                        die("failed to unpack tree object %s", arg);
 171                stage++;
 172        }
 173        if (nr_trees == 0 && !read_empty)
 174                warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 175        else if (nr_trees > 0 && read_empty)
 176                die("passing trees as arguments contradicts --empty");
 177
 178        if (1 < opts.index_only + opts.update)
 179                die("-u and -i at the same time makes no sense");
 180        if ((opts.update||opts.index_only) && !opts.merge)
 181                die("%s is meaningless without -m, --reset, or --prefix",
 182                    opts.update ? "-u" : "-i");
 183        if ((opts.dir && !opts.update))
 184                die("--exclude-per-directory is meaningless unless -u");
 185        if (opts.merge && !opts.index_only)
 186                setup_work_tree();
 187
 188        if (opts.merge) {
 189                if (stage < 2)
 190                        die("just how do you expect me to merge %d trees?", stage-1);
 191                switch (stage - 1) {
 192                case 1:
 193                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 194                        break;
 195                case 2:
 196                        opts.fn = twoway_merge;
 197                        opts.initial_checkout = is_cache_unborn();
 198                        break;
 199                case 3:
 200                default:
 201                        opts.fn = threeway_merge;
 202                        break;
 203                }
 204
 205                if (stage - 1 >= 3)
 206                        opts.head_idx = stage - 2;
 207                else
 208                        opts.head_idx = 1;
 209        }
 210
 211        if (opts.debug_unpack)
 212                opts.fn = debug_merge;
 213
 214        cache_tree_free(&active_cache_tree);
 215        for (i = 0; i < nr_trees; i++) {
 216                struct tree *tree = trees[i];
 217                parse_tree(tree);
 218                init_tree_desc(t+i, tree->buffer, tree->size);
 219        }
 220        if (unpack_trees(nr_trees, t, &opts))
 221                return 128;
 222
 223        if (opts.debug_unpack || opts.dry_run)
 224                return 0; /* do not write the index out */
 225
 226        /*
 227         * When reading only one tree (either the most basic form,
 228         * "-m ent" or "--reset ent" form), we can obtain a fully
 229         * valid cache-tree because the index must match exactly
 230         * what came from the tree.
 231         */
 232        if (nr_trees == 1 && !opts.prefix)
 233                prime_cache_tree(&active_cache_tree, trees[0]);
 234
 235        if (write_cache(newfd, active_cache, active_nr) ||
 236            commit_locked_index(&lock_file))
 237                die("unable to write new index file");
 238        return 0;
 239}