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
  17 static int nr_trees;
  18 static struct tree *trees[MAX_UNPACK_TREES];
  19
  20 static 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
  33 static 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
  38 static 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
  45 static 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
  67 static void debug_stage(const char *label, struct cache_entry *ce,
  68                         struct unpack_trees_options *o)
  69 {
  70         printf("%s ", label);
  71         if (!ce)
  72                 printf("(missing)\n");
  73         else if (ce == o->df_conflict_entry)
  74                 printf("(conflict)\n");
  75         else
  76                 printf("%06o #%d %s %.8s\n",
  77                        ce->ce_mode, ce_stage(ce), ce->name,
  78                        sha1_to_hex(ce->sha1));
  79 }
  80
  81 static int debug_merge(struct cache_entry **stages, struct unpack_trees_options *o)
  82 {
  83         int i;
  84
  85         printf("* %d-way merge\n", o->merge_size);
  86         debug_stage("index", stages[0], o);
  87         for (i = 1; i <= o->merge_size; i++) {
  88                 char buf[24];
  89                 sprintf(buf, "ent#%d", i);
  90                 debug_stage(buf, stages[i], o);
  91         }
  92         return 0;
  93 }
  94
  95 static struct lock_file lock_file;
  96
  97 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  98 {
  99         int i, newfd, stage = 0;
 100         unsigned char sha1[20];
 101         struct tree_desc t[MAX_UNPACK_TREES];
 102         struct unpack_trees_options opts;
 103         int prefix_set = 0;
 104         const struct option read_tree_options[] = {
 105                 { OPTION_CALLBACK, 0, "index-output", NULL, "FILE",
 106                   "write resulting index to <FILE>",
 107                   PARSE_OPT_NONEG, index_output_cb },
 108                 OPT__VERBOSE(&opts.verbose_update),
 109                 OPT_GROUP("Merging"),
 110                 OPT_SET_INT('m', NULL, &opts.merge,
 111                             "perform a merge in addition to a read", 1),
 112                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
 113                             "3-way merge if no file level merging required", 1),
 114                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
 115                             "3-way merge in presence of adds and removes", 1),
 116                 OPT_SET_INT(0, "reset", &opts.reset,
 117                             "same as -m, but discard unmerged entries", 1),
 118                 { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
 119                   "read the tree into the index under <subdirectory>/",
 120                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 121                 OPT_SET_INT('u', NULL, &opts.update,
 122                             "update working tree with merge result", 1),
 123                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 124                   "gitignore",
 125                   "allow explicitly ignored files to be overwritten",
 126                   PARSE_OPT_NONEG, exclude_per_directory_cb },
 127                 OPT_SET_INT('i', NULL, &opts.index_only,
 128                             "don't check the working tree after merging", 1),
 129                 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
 130                             "debug unpack-trees", 1),
 131                 OPT_END()
 132         };
 133
 134         memset(&opts, 0, sizeof(opts));
 135         opts.head_idx = -1;
 136         opts.src_index = &the_index;
 137         opts.dst_index = &the_index;
 138
 139         git_config(git_default_config, NULL);
 140
 141         newfd = hold_locked_index(&lock_file, 1);
 142
 143         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 144                              read_tree_usage, 0);
 145
 146         prefix_set = opts.prefix ? 1 : 0;
 147         if (1 < opts.merge + opts.reset + prefix_set)
 148                 die("Which one? -m, --reset, or --prefix?");
 149
 150         if (opts.reset || opts.merge || opts.prefix) {
 151                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
 152                         die("You need to resolve your current index first");
 153                 stage = opts.merge = 1;
 154         }
 155
 156         for (i = 0; i < argc; i++) {
 157                 const char *arg = argv[i];
 158
 159                 if (get_sha1(arg, sha1))
 160                         die("Not a valid object name %s", arg);
 161                 if (list_tree(sha1) < 0)
 162                         die("failed to unpack tree object %s", arg);
 163                 stage++;
 164         }
 165         if (1 < opts.index_only + opts.update)
 166                 die("-u and -i at the same time makes no sense");
 167         if ((opts.update||opts.index_only) && !opts.merge)
 168                 die("%s is meaningless without -m, --reset, or --prefix",
 169                     opts.update ? "-u" : "-i");
 170         if ((opts.dir && !opts.update))
 171                 die("--exclude-per-directory is meaningless unless -u");
 172         if (opts.merge && !opts.index_only)
 173                 setup_work_tree();
 174
 175         if (opts.merge) {
 176                 if (stage < 2)
 177                         die("just how do you expect me to merge %d trees?", stage-1);
 178                 switch (stage - 1) {
 179                 case 1:
 180                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 181                         break;
 182                 case 2:
 183                         opts.fn = twoway_merge;
 184                         opts.initial_checkout = is_cache_unborn();
 185                         break;
 186                 case 3:
 187                 default:
 188                         opts.fn = threeway_merge;
 189                         break;
 190                 }
 191
 192                 if (stage - 1 >= 3)
 193                         opts.head_idx = stage - 2;
 194                 else
 195                         opts.head_idx = 1;
 196         }
 197
 198         if (opts.debug_unpack)
 199                 opts.fn = debug_merge;
 200
 201         cache_tree_free(&active_cache_tree);
 202         for (i = 0; i < nr_trees; i++) {
 203                 struct tree *tree = trees[i];
 204                 parse_tree(tree);
 205                 init_tree_desc(t+i, tree->buffer, tree->size);
 206         }
 207         if (unpack_trees(nr_trees, t, &opts))
 208                 return 128;
 209
 210         if (opts.debug_unpack)
 211                 return 0; /* do not write the index out */
 212
 213         /*
 214          * When reading only one tree (either the most basic form,
 215          * "-m ent" or "--reset ent" form), we can obtain a fully
 216          * valid cache-tree because the index must match exactly
 217          * what came from the tree.
 218          *
 219          * The same holds true if we are switching between two trees
 220          * using read-tree -m A B.  The index must match B after that.
 221          */
 222         if (nr_trees == 1 && !opts.prefix)
 223                 prime_cache_tree(&active_cache_tree, trees[0]);
 224         else if (nr_trees == 2 && opts.merge)
 225                 prime_cache_tree(&active_cache_tree, trees[1]);
 226
 227         if (write_cache(newfd, active_cache, active_nr) ||
 228             commit_locked_index(&lock_file))
 229                 die("unable to write new index file");
 230         return 0;
 231 }