Windows: boost startup by avoiding a static dependency on shell32.dll
[git/dscho.git] / builtin-read-tree.c
blob50413ca17df294a8b10dd406db55a24cf601bb55
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
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"
17 static int nr_trees;
18 static struct tree *trees[MAX_UNPACK_TREES];
20 static int list_tree(unsigned char *sha1)
22         struct tree *tree;
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;
33 static const char * const read_tree_usage[] = {
34         "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>]]",
35         NULL
38 static int index_output_cb(const struct option *opt, const char *arg,
39                                  int unset)
41         set_alternate_index_output(arg);
42         return 0;
45 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
46                                     int unset)
48         struct dir_struct *dir;
49         struct unpack_trees_options *opts;
51         opts = (struct unpack_trees_options *)opt->value;
53         if (opts->dir)
54                 die("more than one --exclude-per-directory given.");
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;
67 static struct lock_file lock_file;
69 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
71         int i, newfd, stage = 0;
72         unsigned char sha1[20];
73         struct tree_desc t[MAX_UNPACK_TREES];
74         struct unpack_trees_options opts;
75         int prefix_set = 0;
76         const struct option read_tree_options[] = {
77                 { OPTION_CALLBACK, 0, "index-output", NULL, "FILE",
78                   "write resulting index to <FILE>",
79                   PARSE_OPT_NONEG, index_output_cb },
80                 OPT__VERBOSE(&opts.verbose_update),
81                 OPT_GROUP("Merging"),
82                 OPT_SET_INT('m', NULL, &opts.merge,
83                             "perform a merge in addition to a read", 1),
84                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
85                             "3-way merge if no file level merging required", 1),
86                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
87                             "3-way merge in presence of adds and removes", 1),
88                 OPT_SET_INT(0, "reset", &opts.reset,
89                             "same as -m, but discard unmerged entries", 1),
90                 { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
91                   "read the tree into the index under <subdirectory>/",
92                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
93                 OPT_SET_INT('u', NULL, &opts.update,
94                             "update working tree with merge result", 1),
95                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
96                   "gitignore",
97                   "allow explicitly ignored files to be overwritten",
98                   PARSE_OPT_NONEG, exclude_per_directory_cb },
99                 OPT_SET_INT('i', NULL, &opts.index_only,
100                             "don't check the working tree after merging", 1),
101                 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
102                             "skip applying sparse checkout filter", 1),
103                 OPT_END()
104         };
106         memset(&opts, 0, sizeof(opts));
107         opts.head_idx = -1;
108         opts.src_index = &the_index;
109         opts.dst_index = &the_index;
111         git_config(git_default_config, NULL);
113         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
114                              read_tree_usage, 0);
116         newfd = hold_locked_index(&lock_file, 1);
118         prefix_set = opts.prefix ? 1 : 0;
119         if (1 < opts.merge + opts.reset + prefix_set)
120                 die("Which one? -m, --reset, or --prefix?");
122         if (opts.reset || opts.merge || opts.prefix) {
123                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
124                         die("You need to resolve your current index first");
125                 stage = opts.merge = 1;
126         }
128         for (i = 0; i < argc; i++) {
129                 const char *arg = argv[i];
131                 if (get_sha1(arg, sha1))
132                         die("Not a valid object name %s", arg);
133                 if (list_tree(sha1) < 0)
134                         die("failed to unpack tree object %s", arg);
135                 stage++;
136         }
137         if (1 < opts.index_only + opts.update)
138                 die("-u and -i at the same time makes no sense");
139         if ((opts.update||opts.index_only) && !opts.merge)
140                 die("%s is meaningless without -m, --reset, or --prefix",
141                     opts.update ? "-u" : "-i");
142         if ((opts.dir && !opts.update))
143                 die("--exclude-per-directory is meaningless unless -u");
144         if (opts.merge && !opts.index_only)
145                 setup_work_tree();
147         if (opts.merge) {
148                 if (stage < 2)
149                         die("just how do you expect me to merge %d trees?", stage-1);
150                 switch (stage - 1) {
151                 case 1:
152                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
153                         break;
154                 case 2:
155                         opts.fn = twoway_merge;
156                         opts.initial_checkout = is_cache_unborn();
157                         break;
158                 case 3:
159                 default:
160                         opts.fn = threeway_merge;
161                         break;
162                 }
164                 if (stage - 1 >= 3)
165                         opts.head_idx = stage - 2;
166                 else
167                         opts.head_idx = 1;
168         }
170         cache_tree_free(&active_cache_tree);
171         for (i = 0; i < nr_trees; i++) {
172                 struct tree *tree = trees[i];
173                 parse_tree(tree);
174                 init_tree_desc(t+i, tree->buffer, tree->size);
175         }
176         if (unpack_trees(nr_trees, t, &opts))
177                 return 128;
179         /*
180          * When reading only one tree (either the most basic form,
181          * "-m ent" or "--reset ent" form), we can obtain a fully
182          * valid cache-tree because the index must match exactly
183          * what came from the tree.
184          *
185          * The same holds true if we are switching between two trees
186          * using read-tree -m A B.  The index must match B after that.
187          */
188         if (nr_trees == 1 && !opts.prefix)
189                 prime_cache_tree(&active_cache_tree, trees[0]);
190         else if (nr_trees == 2 && opts.merge)
191                 prime_cache_tree(&active_cache_tree, trees[1]);
193         if (write_cache(newfd, active_cache, active_nr) ||
194             commit_locked_index(&lock_file))
195                 die("unable to write new index file");
196         return 0;