Merge branch 'cb/compat-mmap-is-private-read-only'
[git] / builtin / reset.c
1 /*
2  * "git reset" builtin command
3  *
4  * Copyright (c) 2007 Carlos Rica
5  *
6  * Based on git-reset.sh, which is
7  *
8  * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
9  */
10 #include "builtin.h"
11 #include "config.h"
12 #include "lockfile.h"
13 #include "tag.h"
14 #include "object.h"
15 #include "pretty.h"
16 #include "run-command.h"
17 #include "refs.h"
18 #include "diff.h"
19 #include "diffcore.h"
20 #include "tree.h"
21 #include "branch.h"
22 #include "parse-options.h"
23 #include "unpack-trees.h"
24 #include "cache-tree.h"
25 #include "submodule.h"
26 #include "submodule-config.h"
27
28 static const char * const git_reset_usage[] = {
29         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
30         N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
31         N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
32         NULL
33 };
34
35 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
36 static const char *reset_type_names[] = {
37         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
38 };
39
40 static inline int is_merge(void)
41 {
42         return !access(git_path_merge_head(the_repository), F_OK);
43 }
44
45 static int reset_index(const struct object_id *oid, int reset_type, int quiet)
46 {
47         int i, nr = 0;
48         struct tree_desc desc[2];
49         struct tree *tree;
50         struct unpack_trees_options opts;
51         int ret = -1;
52
53         memset(&opts, 0, sizeof(opts));
54         opts.head_idx = 1;
55         opts.src_index = &the_index;
56         opts.dst_index = &the_index;
57         opts.fn = oneway_merge;
58         opts.merge = 1;
59         if (!quiet)
60                 opts.verbose_update = 1;
61         switch (reset_type) {
62         case KEEP:
63         case MERGE:
64                 opts.update = 1;
65                 break;
66         case HARD:
67                 opts.update = 1;
68                 /* fallthrough */
69         default:
70                 opts.reset = 1;
71         }
72
73         read_cache_unmerged();
74
75         if (reset_type == KEEP) {
76                 struct object_id head_oid;
77                 if (get_oid("HEAD", &head_oid))
78                         return error(_("You do not have a valid HEAD."));
79                 if (!fill_tree_descriptor(desc + nr, &head_oid))
80                         return error(_("Failed to find tree of HEAD."));
81                 nr++;
82                 opts.fn = twoway_merge;
83         }
84
85         if (!fill_tree_descriptor(desc + nr, oid)) {
86                 error(_("Failed to find tree of %s."), oid_to_hex(oid));
87                 goto out;
88         }
89         nr++;
90
91         if (unpack_trees(nr, desc, &opts))
92                 goto out;
93
94         if (reset_type == MIXED || reset_type == HARD) {
95                 tree = parse_tree_indirect(oid);
96                 prime_cache_tree(&the_index, tree);
97         }
98
99         ret = 0;
100
101 out:
102         for (i = 0; i < nr; i++)
103                 free((void *)desc[i].buffer);
104         return ret;
105 }
106
107 static void print_new_head_line(struct commit *commit)
108 {
109         struct strbuf buf = STRBUF_INIT;
110
111         printf(_("HEAD is now at %s"),
112                 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
113
114         pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
115         if (buf.len > 0)
116                 printf(" %s", buf.buf);
117         putchar('\n');
118         strbuf_release(&buf);
119 }
120
121 static void update_index_from_diff(struct diff_queue_struct *q,
122                 struct diff_options *opt, void *data)
123 {
124         int i;
125         int intent_to_add = *(int *)data;
126
127         for (i = 0; i < q->nr; i++) {
128                 struct diff_filespec *one = q->queue[i]->one;
129                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
130                 struct cache_entry *ce;
131
132                 if (is_missing && !intent_to_add) {
133                         remove_file_from_cache(one->path);
134                         continue;
135                 }
136
137                 ce = make_cache_entry(&the_index, one->mode, &one->oid, one->path,
138                                       0, 0);
139                 if (!ce)
140                         die(_("make_cache_entry failed for path '%s'"),
141                             one->path);
142                 if (is_missing) {
143                         ce->ce_flags |= CE_INTENT_TO_ADD;
144                         set_object_name_for_intent_to_add_entry(ce);
145                 }
146                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
147         }
148 }
149
150 static int read_from_tree(const struct pathspec *pathspec,
151                           struct object_id *tree_oid,
152                           int intent_to_add)
153 {
154         struct diff_options opt;
155
156         memset(&opt, 0, sizeof(opt));
157         copy_pathspec(&opt.pathspec, pathspec);
158         opt.output_format = DIFF_FORMAT_CALLBACK;
159         opt.format_callback = update_index_from_diff;
160         opt.format_callback_data = &intent_to_add;
161         opt.flags.override_submodule_config = 1;
162         opt.repo = the_repository;
163
164         if (do_diff_cache(tree_oid, &opt))
165                 return 1;
166         diffcore_std(&opt);
167         diff_flush(&opt);
168         clear_pathspec(&opt.pathspec);
169
170         return 0;
171 }
172
173 static void set_reflog_message(struct strbuf *sb, const char *action,
174                                const char *rev)
175 {
176         const char *rla = getenv("GIT_REFLOG_ACTION");
177
178         strbuf_reset(sb);
179         if (rla)
180                 strbuf_addf(sb, "%s: %s", rla, action);
181         else if (rev)
182                 strbuf_addf(sb, "reset: moving to %s", rev);
183         else
184                 strbuf_addf(sb, "reset: %s", action);
185 }
186
187 static void die_if_unmerged_cache(int reset_type)
188 {
189         if (is_merge() || unmerged_cache())
190                 die(_("Cannot do a %s reset in the middle of a merge."),
191                     _(reset_type_names[reset_type]));
192
193 }
194
195 static void parse_args(struct pathspec *pathspec,
196                        const char **argv, const char *prefix,
197                        int patch_mode,
198                        const char **rev_ret)
199 {
200         const char *rev = "HEAD";
201         struct object_id unused;
202         /*
203          * Possible arguments are:
204          *
205          * git reset [-opts] [<rev>]
206          * git reset [-opts] <tree> [<paths>...]
207          * git reset [-opts] <tree> -- [<paths>...]
208          * git reset [-opts] -- [<paths>...]
209          * git reset [-opts] <paths>...
210          *
211          * At this point, argv points immediately after [-opts].
212          */
213
214         if (argv[0]) {
215                 if (!strcmp(argv[0], "--")) {
216                         argv++; /* reset to HEAD, possibly with paths */
217                 } else if (argv[1] && !strcmp(argv[1], "--")) {
218                         rev = argv[0];
219                         argv += 2;
220                 }
221                 /*
222                  * Otherwise, argv[0] could be either <rev> or <paths> and
223                  * has to be unambiguous. If there is a single argument, it
224                  * can not be a tree
225                  */
226                 else if ((!argv[1] && !get_oid_committish(argv[0], &unused)) ||
227                          (argv[1] && !get_oid_treeish(argv[0], &unused))) {
228                         /*
229                          * Ok, argv[0] looks like a commit/tree; it should not
230                          * be a filename.
231                          */
232                         verify_non_filename(prefix, argv[0]);
233                         rev = *argv++;
234                 } else {
235                         /* Otherwise we treat this as a filename */
236                         verify_filename(prefix, argv[0], 1);
237                 }
238         }
239         *rev_ret = rev;
240
241         if (read_cache() < 0)
242                 die(_("index file corrupt"));
243
244         parse_pathspec(pathspec, 0,
245                        PATHSPEC_PREFER_FULL |
246                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
247                        prefix, argv);
248 }
249
250 static int reset_refs(const char *rev, const struct object_id *oid)
251 {
252         int update_ref_status;
253         struct strbuf msg = STRBUF_INIT;
254         struct object_id *orig = NULL, oid_orig,
255                 *old_orig = NULL, oid_old_orig;
256
257         if (!get_oid("ORIG_HEAD", &oid_old_orig))
258                 old_orig = &oid_old_orig;
259         if (!get_oid("HEAD", &oid_orig)) {
260                 orig = &oid_orig;
261                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
262                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
263                            UPDATE_REFS_MSG_ON_ERR);
264         } else if (old_orig)
265                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
266         set_reflog_message(&msg, "updating HEAD", rev);
267         update_ref_status = update_ref(msg.buf, "HEAD", oid, orig, 0,
268                                        UPDATE_REFS_MSG_ON_ERR);
269         strbuf_release(&msg);
270         return update_ref_status;
271 }
272
273 static int git_reset_config(const char *var, const char *value, void *cb)
274 {
275         if (!strcmp(var, "submodule.recurse"))
276                 return git_default_submodule_config(var, value, cb);
277
278         return git_default_config(var, value, cb);
279 }
280
281 int cmd_reset(int argc, const char **argv, const char *prefix)
282 {
283         int reset_type = NONE, update_ref_status = 0, quiet = 0;
284         int patch_mode = 0, unborn;
285         const char *rev;
286         struct object_id oid;
287         struct pathspec pathspec;
288         int intent_to_add = 0;
289         const struct option options[] = {
290                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
291                 OPT_SET_INT(0, "mixed", &reset_type,
292                                                 N_("reset HEAD and index"), MIXED),
293                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
294                 OPT_SET_INT(0, "hard", &reset_type,
295                                 N_("reset HEAD, index and working tree"), HARD),
296                 OPT_SET_INT(0, "merge", &reset_type,
297                                 N_("reset HEAD, index and working tree"), MERGE),
298                 OPT_SET_INT(0, "keep", &reset_type,
299                                 N_("reset HEAD but keep local changes"), KEEP),
300                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
301                             "reset", "control recursive updating of submodules",
302                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
303                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
304                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
305                                 N_("record only the fact that removed paths will be added later")),
306                 OPT_END()
307         };
308
309         git_config(git_reset_config, NULL);
310
311         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
312                                                 PARSE_OPT_KEEP_DASHDASH);
313         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
314
315         unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
316         if (unborn) {
317                 /* reset on unborn branch: treat as reset to empty tree */
318                 oidcpy(&oid, the_hash_algo->empty_tree);
319         } else if (!pathspec.nr) {
320                 struct commit *commit;
321                 if (get_oid_committish(rev, &oid))
322                         die(_("Failed to resolve '%s' as a valid revision."), rev);
323                 commit = lookup_commit_reference(the_repository, &oid);
324                 if (!commit)
325                         die(_("Could not parse object '%s'."), rev);
326                 oidcpy(&oid, &commit->object.oid);
327         } else {
328                 struct tree *tree;
329                 if (get_oid_treeish(rev, &oid))
330                         die(_("Failed to resolve '%s' as a valid tree."), rev);
331                 tree = parse_tree_indirect(&oid);
332                 if (!tree)
333                         die(_("Could not parse object '%s'."), rev);
334                 oidcpy(&oid, &tree->object.oid);
335         }
336
337         if (patch_mode) {
338                 if (reset_type != NONE)
339                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
340                 return run_add_interactive(rev, "--patch=reset", &pathspec);
341         }
342
343         /* git reset tree [--] paths... can be used to
344          * load chosen paths from the tree into the index without
345          * affecting the working tree nor HEAD. */
346         if (pathspec.nr) {
347                 if (reset_type == MIXED)
348                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
349                 else if (reset_type != NONE)
350                         die(_("Cannot do %s reset with paths."),
351                                         _(reset_type_names[reset_type]));
352         }
353         if (reset_type == NONE)
354                 reset_type = MIXED; /* by default */
355
356         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
357                 setup_work_tree();
358
359         if (reset_type == MIXED && is_bare_repository())
360                 die(_("%s reset is not allowed in a bare repository"),
361                     _(reset_type_names[reset_type]));
362
363         if (intent_to_add && reset_type != MIXED)
364                 die(_("-N can only be used with --mixed"));
365
366         /* Soft reset does not touch the index file nor the working tree
367          * at all, but requires them in a good order.  Other resets reset
368          * the index file to the tree object we are switching to. */
369         if (reset_type == SOFT || reset_type == KEEP)
370                 die_if_unmerged_cache(reset_type);
371
372         if (reset_type != SOFT) {
373                 struct lock_file lock = LOCK_INIT;
374                 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
375                 if (reset_type == MIXED) {
376                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
377                         if (read_from_tree(&pathspec, &oid, intent_to_add))
378                                 return 1;
379                         if (get_git_work_tree())
380                                 refresh_index(&the_index, flags, NULL, NULL,
381                                               _("Unstaged changes after reset:"));
382                 } else {
383                         int err = reset_index(&oid, reset_type, quiet);
384                         if (reset_type == KEEP && !err)
385                                 err = reset_index(&oid, MIXED, quiet);
386                         if (err)
387                                 die(_("Could not reset index file to revision '%s'."), rev);
388                 }
389
390                 if (write_locked_index(&the_index, &lock, COMMIT_LOCK))
391                         die(_("Could not write new index file."));
392         }
393
394         if (!pathspec.nr && !unborn) {
395                 /* Any resets without paths update HEAD to the head being
396                  * switched to, saving the previous head in ORIG_HEAD before. */
397                 update_ref_status = reset_refs(rev, &oid);
398
399                 if (reset_type == HARD && !update_ref_status && !quiet)
400                         print_new_head_line(lookup_commit_reference(the_repository, &oid));
401         }
402         if (!pathspec.nr)
403                 remove_branch_state();
404
405         return update_ref_status;
406 }