Merge branch 'jk/make-coccicheck-detect-errors'
[git] / 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 "lockfile.h"
9 #include "object.h"
10 #include "tree.h"
11 #include "tree-walk.h"
12 #include "cache-tree.h"
13 #include "unpack-trees.h"
14 #include "dir.h"
15 #include "builtin.h"
16 #include "parse-options.h"
17 #include "resolve-undo.h"
18 #include "submodule.h"
19 #include "submodule-config.h"
20
21 static int nr_trees;
22 static int read_empty;
23 static struct tree *trees[MAX_UNPACK_TREES];
24 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
25
26 static int list_tree(unsigned char *sha1)
27 {
28         struct tree *tree;
29
30         if (nr_trees >= MAX_UNPACK_TREES)
31                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
32         tree = parse_tree_indirect(sha1);
33         if (!tree)
34                 return -1;
35         trees[nr_trees++] = tree;
36         return 0;
37 }
38
39 static const char * const read_tree_usage[] = {
40         N_("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>]])"),
41         NULL
42 };
43
44 static int index_output_cb(const struct option *opt, const char *arg,
45                                  int unset)
46 {
47         set_alternate_index_output(arg);
48         return 0;
49 }
50
51 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
52                                     int unset)
53 {
54         struct dir_struct *dir;
55         struct unpack_trees_options *opts;
56
57         opts = (struct unpack_trees_options *)opt->value;
58
59         if (opts->dir)
60                 die("more than one --exclude-per-directory given.");
61
62         dir = xcalloc(1, sizeof(*opts->dir));
63         dir->flags |= DIR_SHOW_IGNORED;
64         dir->exclude_per_dir = arg;
65         opts->dir = dir;
66         /* We do not need to nor want to do read-directory
67          * here; we are merely interested in reusing the
68          * per directory ignore stack mechanism.
69          */
70         return 0;
71 }
72
73 static void debug_stage(const char *label, const struct cache_entry *ce,
74                         struct unpack_trees_options *o)
75 {
76         printf("%s ", label);
77         if (!ce)
78                 printf("(missing)\n");
79         else if (ce == o->df_conflict_entry)
80                 printf("(conflict)\n");
81         else
82                 printf("%06o #%d %s %.8s\n",
83                        ce->ce_mode, ce_stage(ce), ce->name,
84                        oid_to_hex(&ce->oid));
85 }
86
87 static int debug_merge(const struct cache_entry * const *stages,
88                        struct unpack_trees_options *o)
89 {
90         int i;
91
92         printf("* %d-way merge\n", o->merge_size);
93         debug_stage("index", stages[0], o);
94         for (i = 1; i <= o->merge_size; i++) {
95                 char buf[24];
96                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
97                 debug_stage(buf, stages[i], o);
98         }
99         return 0;
100 }
101
102 static int option_parse_recurse_submodules(const struct option *opt,
103                                            const char *arg, int unset)
104 {
105         if (unset) {
106                 recurse_submodules = RECURSE_SUBMODULES_OFF;
107                 return 0;
108         }
109         if (arg)
110                 recurse_submodules =
111                         parse_update_recurse_submodules_arg(opt->long_name,
112                                                             arg);
113         else
114                 recurse_submodules = RECURSE_SUBMODULES_ON;
115
116         return 0;
117 }
118
119 static struct lock_file lock_file;
120
121 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
122 {
123         int i, stage = 0;
124         unsigned char sha1[20];
125         struct tree_desc t[MAX_UNPACK_TREES];
126         struct unpack_trees_options opts;
127         int prefix_set = 0;
128         const struct option read_tree_options[] = {
129                 { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
130                   N_("write resulting index to <file>"),
131                   PARSE_OPT_NONEG, index_output_cb },
132                 OPT_BOOL(0, "empty", &read_empty,
133                             N_("only empty the index")),
134                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
135                 OPT_GROUP(N_("Merging")),
136                 OPT_BOOL('m', NULL, &opts.merge,
137                          N_("perform a merge in addition to a read")),
138                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
139                          N_("3-way merge if no file level merging required")),
140                 OPT_BOOL(0, "aggressive", &opts.aggressive,
141                          N_("3-way merge in presence of adds and removes")),
142                 OPT_BOOL(0, "reset", &opts.reset,
143                          N_("same as -m, but discard unmerged entries")),
144                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
145                   N_("read the tree into the index under <subdirectory>/"),
146                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
147                 OPT_BOOL('u', NULL, &opts.update,
148                          N_("update working tree with merge result")),
149                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
150                   N_("gitignore"),
151                   N_("allow explicitly ignored files to be overwritten"),
152                   PARSE_OPT_NONEG, exclude_per_directory_cb },
153                 OPT_BOOL('i', NULL, &opts.index_only,
154                          N_("don't check the working tree after merging")),
155                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
156                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
157                          N_("skip applying sparse checkout filter")),
158                 OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
159                          N_("debug unpack-trees")),
160                 { OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
161                             "checkout", "control recursive updating of submodules",
162                             PARSE_OPT_OPTARG, option_parse_recurse_submodules },
163                 OPT_END()
164         };
165
166         memset(&opts, 0, sizeof(opts));
167         opts.head_idx = -1;
168         opts.src_index = &the_index;
169         opts.dst_index = &the_index;
170
171         git_config(git_default_config, NULL);
172
173         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
174                              read_tree_usage, 0);
175
176         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
177
178         if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
179                 gitmodules_config();
180                 git_config(submodule_config, NULL);
181                 set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
182         }
183
184         prefix_set = opts.prefix ? 1 : 0;
185         if (1 < opts.merge + opts.reset + prefix_set)
186                 die("Which one? -m, --reset, or --prefix?");
187
188         /*
189          * NEEDSWORK
190          *
191          * The old index should be read anyway even if we're going to
192          * destroy all index entries because we still need to preserve
193          * certain information such as index version or split-index
194          * mode.
195          */
196
197         if (opts.reset || opts.merge || opts.prefix) {
198                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
199                         die("You need to resolve your current index first");
200                 stage = opts.merge = 1;
201         }
202         resolve_undo_clear();
203
204         for (i = 0; i < argc; i++) {
205                 const char *arg = argv[i];
206
207                 if (get_sha1(arg, sha1))
208                         die("Not a valid object name %s", arg);
209                 if (list_tree(sha1) < 0)
210                         die("failed to unpack tree object %s", arg);
211                 stage++;
212         }
213         if (nr_trees == 0 && !read_empty)
214                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
215         else if (nr_trees > 0 && read_empty)
216                 die("passing trees as arguments contradicts --empty");
217
218         if (1 < opts.index_only + opts.update)
219                 die("-u and -i at the same time makes no sense");
220         if ((opts.update || opts.index_only) && !opts.merge)
221                 die("%s is meaningless without -m, --reset, or --prefix",
222                     opts.update ? "-u" : "-i");
223         if ((opts.dir && !opts.update))
224                 die("--exclude-per-directory is meaningless unless -u");
225         if (opts.merge && !opts.index_only)
226                 setup_work_tree();
227
228         if (opts.merge) {
229                 if (stage < 2)
230                         die("just how do you expect me to merge %d trees?", stage-1);
231                 switch (stage - 1) {
232                 case 1:
233                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
234                         break;
235                 case 2:
236                         opts.fn = twoway_merge;
237                         opts.initial_checkout = is_cache_unborn();
238                         break;
239                 case 3:
240                 default:
241                         opts.fn = threeway_merge;
242                         break;
243                 }
244
245                 if (stage - 1 >= 3)
246                         opts.head_idx = stage - 2;
247                 else
248                         opts.head_idx = 1;
249         }
250
251         if (opts.debug_unpack)
252                 opts.fn = debug_merge;
253
254         cache_tree_free(&active_cache_tree);
255         for (i = 0; i < nr_trees; i++) {
256                 struct tree *tree = trees[i];
257                 parse_tree(tree);
258                 init_tree_desc(t+i, tree->buffer, tree->size);
259         }
260         if (unpack_trees(nr_trees, t, &opts))
261                 return 128;
262
263         if (opts.debug_unpack || opts.dry_run)
264                 return 0; /* do not write the index out */
265
266         /*
267          * When reading only one tree (either the most basic form,
268          * "-m ent" or "--reset ent" form), we can obtain a fully
269          * valid cache-tree because the index must match exactly
270          * what came from the tree.
271          */
272         if (nr_trees == 1 && !opts.prefix)
273                 prime_cache_tree(&the_index, trees[0]);
274
275         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
276                 die("unable to write new index file");
277         return 0;
278 }