msysGit-based Git for Windows 1.x was superseded by Git for Windows 2.x
[git/mingw/4msysgit.git] / builtin / replace.c
blob294b61b97e20ac9b5684bd6a180da37ebef43db9
1 /*
2 * Builtin "git replace"
4 * Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
6 * Based on builtin/tag.c by Kristian Høgsberg <krh@redhat.com>
7 * and Carlos Rica <jasampler@gmail.com> that was itself based on
8 * git-tag.sh and mktag.c by Linus Torvalds.
9 */
11 #include "cache.h"
12 #include "builtin.h"
13 #include "refs.h"
14 #include "parse-options.h"
15 #include "run-command.h"
16 #include "tag.h"
18 static const char * const git_replace_usage[] = {
19 N_("git replace [-f] <object> <replacement>"),
20 N_("git replace [-f] --edit <object>"),
21 N_("git replace [-f] --graft <commit> [<parent>...]"),
22 N_("git replace -d <object>..."),
23 N_("git replace [--format=<format>] [-l [<pattern>]]"),
24 NULL
27 enum replace_format {
28 REPLACE_FORMAT_SHORT,
29 REPLACE_FORMAT_MEDIUM,
30 REPLACE_FORMAT_LONG
33 struct show_data {
34 const char *pattern;
35 enum replace_format format;
38 static int show_reference(const char *refname, const unsigned char *sha1,
39 int flag, void *cb_data)
41 struct show_data *data = cb_data;
43 if (!wildmatch(data->pattern, refname, 0, NULL)) {
44 if (data->format == REPLACE_FORMAT_SHORT)
45 printf("%s\n", refname);
46 else if (data->format == REPLACE_FORMAT_MEDIUM)
47 printf("%s -> %s\n", refname, sha1_to_hex(sha1));
48 else { /* data->format == REPLACE_FORMAT_LONG */
49 unsigned char object[20];
50 enum object_type obj_type, repl_type;
52 if (get_sha1(refname, object))
53 return error("Failed to resolve '%s' as a valid ref.", refname);
55 obj_type = sha1_object_info(object, NULL);
56 repl_type = sha1_object_info(sha1, NULL);
58 printf("%s (%s) -> %s (%s)\n", refname, typename(obj_type),
59 sha1_to_hex(sha1), typename(repl_type));
63 return 0;
66 static int list_replace_refs(const char *pattern, const char *format)
68 struct show_data data;
70 if (pattern == NULL)
71 pattern = "*";
72 data.pattern = pattern;
74 if (format == NULL || *format == '\0' || !strcmp(format, "short"))
75 data.format = REPLACE_FORMAT_SHORT;
76 else if (!strcmp(format, "medium"))
77 data.format = REPLACE_FORMAT_MEDIUM;
78 else if (!strcmp(format, "long"))
79 data.format = REPLACE_FORMAT_LONG;
80 else
81 die("invalid replace format '%s'\n"
82 "valid formats are 'short', 'medium' and 'long'\n",
83 format);
85 for_each_replace_ref(show_reference, (void *) &data);
87 return 0;
90 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
91 const unsigned char *sha1);
93 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
95 const char **p, *full_hex;
96 char ref[PATH_MAX];
97 int had_error = 0;
98 unsigned char sha1[20];
100 for (p = argv; *p; p++) {
101 if (get_sha1(*p, sha1)) {
102 error("Failed to resolve '%s' as a valid ref.", *p);
103 had_error = 1;
104 continue;
106 full_hex = sha1_to_hex(sha1);
107 snprintf(ref, sizeof(ref), "refs/replace/%s", full_hex);
108 /* read_ref() may reuse the buffer */
109 full_hex = ref + strlen("refs/replace/");
110 if (read_ref(ref, sha1)) {
111 error("replace ref '%s' not found.", full_hex);
112 had_error = 1;
113 continue;
115 if (fn(full_hex, ref, sha1))
116 had_error = 1;
118 return had_error;
121 static int delete_replace_ref(const char *name, const char *ref,
122 const unsigned char *sha1)
124 if (delete_ref(ref, sha1, 0))
125 return 1;
126 printf("Deleted replace ref '%s'\n", name);
127 return 0;
130 static void check_ref_valid(unsigned char object[20],
131 unsigned char prev[20],
132 char *ref,
133 int ref_size,
134 int force)
136 if (snprintf(ref, ref_size,
137 "refs/replace/%s",
138 sha1_to_hex(object)) > ref_size - 1)
139 die("replace ref name too long: %.*s...", 50, ref);
140 if (check_refname_format(ref, 0))
141 die("'%s' is not a valid ref name.", ref);
143 if (read_ref(ref, prev))
144 hashclr(prev);
145 else if (!force)
146 die("replace ref '%s' already exists", ref);
149 static int replace_object_sha1(const char *object_ref,
150 unsigned char object[20],
151 const char *replace_ref,
152 unsigned char repl[20],
153 int force)
155 unsigned char prev[20];
156 enum object_type obj_type, repl_type;
157 char ref[PATH_MAX];
158 struct ref_lock *lock;
160 obj_type = sha1_object_info(object, NULL);
161 repl_type = sha1_object_info(repl, NULL);
162 if (!force && obj_type != repl_type)
163 die("Objects must be of the same type.\n"
164 "'%s' points to a replaced object of type '%s'\n"
165 "while '%s' points to a replacement object of type '%s'.",
166 object_ref, typename(obj_type),
167 replace_ref, typename(repl_type));
169 check_ref_valid(object, prev, ref, sizeof(ref), force);
171 lock = lock_any_ref_for_update(ref, prev, 0, NULL);
172 if (!lock)
173 die("%s: cannot lock the ref", ref);
174 if (write_ref_sha1(lock, repl, NULL) < 0)
175 die("%s: cannot update the ref", ref);
177 return 0;
180 static int replace_object(const char *object_ref, const char *replace_ref, int force)
182 unsigned char object[20], repl[20];
184 if (get_sha1(object_ref, object))
185 die("Failed to resolve '%s' as a valid ref.", object_ref);
186 if (get_sha1(replace_ref, repl))
187 die("Failed to resolve '%s' as a valid ref.", replace_ref);
189 return replace_object_sha1(object_ref, object, replace_ref, repl, force);
193 * Write the contents of the object named by "sha1" to the file "filename".
194 * If "raw" is true, then the object's raw contents are printed according to
195 * "type". Otherwise, we pretty-print the contents for human editing.
197 static void export_object(const unsigned char *sha1, enum object_type type,
198 int raw, const char *filename)
200 struct child_process cmd = { NULL };
201 int fd;
203 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
204 if (fd < 0)
205 die_errno("unable to open %s for writing", filename);
207 argv_array_push(&cmd.args, "--no-replace-objects");
208 argv_array_push(&cmd.args, "cat-file");
209 if (raw)
210 argv_array_push(&cmd.args, typename(type));
211 else
212 argv_array_push(&cmd.args, "-p");
213 argv_array_push(&cmd.args, sha1_to_hex(sha1));
214 cmd.git_cmd = 1;
215 cmd.out = fd;
217 if (run_command(&cmd))
218 die("cat-file reported failure");
222 * Read a previously-exported (and possibly edited) object back from "filename",
223 * interpreting it as "type", and writing the result to the object database.
224 * The sha1 of the written object is returned via sha1.
226 static void import_object(unsigned char *sha1, enum object_type type,
227 int raw, const char *filename)
229 int fd;
231 fd = open(filename, O_RDONLY);
232 if (fd < 0)
233 die_errno("unable to open %s for reading", filename);
235 if (!raw && type == OBJ_TREE) {
236 const char *argv[] = { "mktree", NULL };
237 struct child_process cmd = { argv };
238 struct strbuf result = STRBUF_INIT;
240 cmd.argv = argv;
241 cmd.git_cmd = 1;
242 cmd.in = fd;
243 cmd.out = -1;
245 if (start_command(&cmd))
246 die("unable to spawn mktree");
248 if (strbuf_read(&result, cmd.out, 41) < 0)
249 die_errno("unable to read from mktree");
250 close(cmd.out);
252 if (finish_command(&cmd))
253 die("mktree reported failure");
254 if (get_sha1_hex(result.buf, sha1) < 0)
255 die("mktree did not return an object name");
257 strbuf_release(&result);
258 } else {
259 struct stat st;
260 int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
262 if (fstat(fd, &st) < 0)
263 die_errno("unable to fstat %s", filename);
264 if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
265 die("unable to write object to database");
266 /* index_fd close()s fd for us */
270 * No need to close(fd) here; both run-command and index-fd
271 * will have done it for us.
275 static int edit_and_replace(const char *object_ref, int force, int raw)
277 char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
278 enum object_type type;
279 unsigned char old[20], new[20], prev[20];
280 char ref[PATH_MAX];
282 if (get_sha1(object_ref, old) < 0)
283 die("Not a valid object name: '%s'", object_ref);
285 type = sha1_object_info(old, NULL);
286 if (type < 0)
287 die("unable to get object type for %s", sha1_to_hex(old));
289 check_ref_valid(old, prev, ref, sizeof(ref), force);
291 export_object(old, type, raw, tmpfile);
292 if (launch_editor(tmpfile, NULL, NULL) < 0)
293 die("editing object file failed");
294 import_object(new, type, raw, tmpfile);
296 free(tmpfile);
298 if (!hashcmp(old, new))
299 return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
301 return replace_object_sha1(object_ref, old, "replacement", new, force);
304 static void replace_parents(struct strbuf *buf, int argc, const char **argv)
306 struct strbuf new_parents = STRBUF_INIT;
307 const char *parent_start, *parent_end;
308 int i;
310 /* find existing parents */
311 parent_start = buf->buf;
312 parent_start += 46; /* "tree " + "hex sha1" + "\n" */
313 parent_end = parent_start;
315 while (starts_with(parent_end, "parent "))
316 parent_end += 48; /* "parent " + "hex sha1" + "\n" */
318 /* prepare new parents */
319 for (i = 0; i < argc; i++) {
320 unsigned char sha1[20];
321 if (get_sha1(argv[i], sha1) < 0)
322 die(_("Not a valid object name: '%s'"), argv[i]);
323 lookup_commit_or_die(sha1, argv[i]);
324 strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
327 /* replace existing parents with new ones */
328 strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
329 new_parents.buf, new_parents.len);
331 strbuf_release(&new_parents);
334 struct check_mergetag_data {
335 int argc;
336 const char **argv;
339 static void check_one_mergetag(struct commit *commit,
340 struct commit_extra_header *extra,
341 void *data)
343 struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
344 const char *ref = mergetag_data->argv[0];
345 unsigned char tag_sha1[20];
346 struct tag *tag;
347 int i;
349 hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
350 tag = lookup_tag(tag_sha1);
351 if (!tag)
352 die(_("bad mergetag in commit '%s'"), ref);
353 if (parse_tag_buffer(tag, extra->value, extra->len))
354 die(_("malformed mergetag in commit '%s'"), ref);
356 /* iterate over new parents */
357 for (i = 1; i < mergetag_data->argc; i++) {
358 unsigned char sha1[20];
359 if (get_sha1(mergetag_data->argv[i], sha1) < 0)
360 die(_("Not a valid object name: '%s'"), mergetag_data->argv[i]);
361 if (!hashcmp(tag->tagged->sha1, sha1))
362 return; /* found */
365 die(_("original commit '%s' contains mergetag '%s' that is discarded; "
366 "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
369 static void check_mergetags(struct commit *commit, int argc, const char **argv)
371 struct check_mergetag_data mergetag_data;
373 mergetag_data.argc = argc;
374 mergetag_data.argv = argv;
375 for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
378 static int create_graft(int argc, const char **argv, int force)
380 unsigned char old[20], new[20];
381 const char *old_ref = argv[0];
382 struct commit *commit;
383 struct strbuf buf = STRBUF_INIT;
384 const char *buffer;
385 unsigned long size;
387 if (get_sha1(old_ref, old) < 0)
388 die(_("Not a valid object name: '%s'"), old_ref);
389 commit = lookup_commit_or_die(old, old_ref);
391 buffer = get_commit_buffer(commit, &size);
392 strbuf_add(&buf, buffer, size);
393 unuse_commit_buffer(commit, buffer);
395 replace_parents(&buf, argc - 1, &argv[1]);
397 if (remove_signature(&buf)) {
398 warning(_("the original commit '%s' has a gpg signature."), old_ref);
399 warning(_("the signature will be removed in the replacement commit!"));
402 check_mergetags(commit, argc, argv);
404 if (write_sha1_file(buf.buf, buf.len, commit_type, new))
405 die(_("could not write replacement commit for: '%s'"), old_ref);
407 strbuf_release(&buf);
409 if (!hashcmp(old, new))
410 return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
412 return replace_object_sha1(old_ref, old, "replacement", new, force);
415 int cmd_replace(int argc, const char **argv, const char *prefix)
417 int force = 0;
418 int raw = 0;
419 const char *format = NULL;
420 enum {
421 MODE_UNSPECIFIED = 0,
422 MODE_LIST,
423 MODE_DELETE,
424 MODE_EDIT,
425 MODE_GRAFT,
426 MODE_REPLACE
427 } cmdmode = MODE_UNSPECIFIED;
428 struct option options[] = {
429 OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
430 OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
431 OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
432 OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
433 OPT_BOOL('f', "force", &force, N_("replace the ref if it exists")),
434 OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
435 OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
436 OPT_END()
439 check_replace_refs = 0;
441 argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
443 if (!cmdmode)
444 cmdmode = argc ? MODE_REPLACE : MODE_LIST;
446 if (format && cmdmode != MODE_LIST)
447 usage_msg_opt("--format cannot be used when not listing",
448 git_replace_usage, options);
450 if (force &&
451 cmdmode != MODE_REPLACE &&
452 cmdmode != MODE_EDIT &&
453 cmdmode != MODE_GRAFT)
454 usage_msg_opt("-f only makes sense when writing a replacement",
455 git_replace_usage, options);
457 if (raw && cmdmode != MODE_EDIT)
458 usage_msg_opt("--raw only makes sense with --edit",
459 git_replace_usage, options);
461 switch (cmdmode) {
462 case MODE_DELETE:
463 if (argc < 1)
464 usage_msg_opt("-d needs at least one argument",
465 git_replace_usage, options);
466 return for_each_replace_name(argv, delete_replace_ref);
468 case MODE_REPLACE:
469 if (argc != 2)
470 usage_msg_opt("bad number of arguments",
471 git_replace_usage, options);
472 return replace_object(argv[0], argv[1], force);
474 case MODE_EDIT:
475 if (argc != 1)
476 usage_msg_opt("-e needs exactly one argument",
477 git_replace_usage, options);
478 return edit_and_replace(argv[0], force, raw);
480 case MODE_GRAFT:
481 if (argc < 1)
482 usage_msg_opt("-g needs at least one argument",
483 git_replace_usage, options);
484 return create_graft(argc, argv, force);
486 case MODE_LIST:
487 if (argc > 1)
488 usage_msg_opt("only one pattern can be given with -l",
489 git_replace_usage, options);
490 return list_replace_refs(argv[0], format);
492 default:
493 die("BUG: invalid cmdmode %d", (int)cmdmode);