Merge branch 'mk/maint-graph-infinity-loop' into maint
[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 "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 int read_empty;
20 static struct tree *trees[MAX_UNPACK_TREES];
21
22 static 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
35 static const char * const read_tree_usage[] = {
36         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>]])"),
37         NULL
38 };
39
40 static 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
47 static 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
69 static 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
83 static 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
97 static struct lock_file lock_file;
98
99 int 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, N_("file"),
108                   N_("write resulting index to <file>"),
109                   PARSE_OPT_NONEG, index_output_cb },
110                 OPT_SET_INT(0, "empty", &read_empty,
111                             N_("only empty the index"), 1),
112                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
113                 OPT_GROUP(N_("Merging")),
114                 OPT_SET_INT('m', NULL, &opts.merge,
115                             N_("perform a merge in addition to a read"), 1),
116                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
117                             N_("3-way merge if no file level merging required"), 1),
118                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
119                             N_("3-way merge in presence of adds and removes"), 1),
120                 OPT_SET_INT(0, "reset", &opts.reset,
121                             N_("same as -m, but discard unmerged entries"), 1),
122                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
123                   N_("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                             N_("update working tree with merge result"), 1),
127                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
128                   N_("gitignore"),
129                   N_("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                             N_("don't check the working tree after merging"), 1),
133                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
134                 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
135                             N_("skip applying sparse checkout filter"), 1),
136                 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
137                             N_("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 }