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
  18 static int nr_trees;
  19 static struct tree *trees[MAX_UNPACK_TREES];
  20
  21 static 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
  34 static 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
  39 static 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
  46 static 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
  68 static 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
  82 static 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
  96 static struct lock_file lock_file;
  97
  98 int 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 }