builtin/replace.c

   1 /*
   2  * Builtin "git replace"
   3  *
   4  * Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
   5  *
   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  */
  10
  11 #include "builtin.h"
  12 #include "config.h"
  13 #include "editor.h"
  14 #include "environment.h"
  15 #include "gettext.h"
  16 #include "hex.h"
  17 #include "refs.h"
  18 #include "parse-options.h"
  19 #include "path.h"
  20 #include "run-command.h"
  21 #include "object-file.h"
  22 #include "object-name.h"
  23 #include "object-store-ll.h"
  24 #include "replace-object.h"
  25 #include "repository.h"
  26 #include "tag.h"
  27 #include "wildmatch.h"
  28
  29 static const char * const git_replace_usage[] = {
  30         N_("git replace [-f] <object> <replacement>"),
  31         N_("git replace [-f] --edit <object>"),
  32         N_("git replace [-f] --graft <commit> [<parent>...]"),
  33         "git replace [-f] --convert-graft-file",
  34         N_("git replace -d <object>..."),
  35         N_("git replace [--format=<format>] [-l [<pattern>]]"),
  36         NULL
  37 };
  38
  39 enum replace_format {
  40         REPLACE_FORMAT_SHORT,
  41         REPLACE_FORMAT_MEDIUM,
  42         REPLACE_FORMAT_LONG
  43 };
  44
  45 struct show_data {
  46         struct repository *repo;
  47         const char *pattern;
  48         enum replace_format format;
  49 };
  50
  51 static int show_reference(const char *refname,
  52                           const struct object_id *oid,
  53                           int flag UNUSED, void *cb_data)
  54 {
  55         struct show_data *data = cb_data;
  56
  57         if (!wildmatch(data->pattern, refname, 0)) {
  58                 if (data->format == REPLACE_FORMAT_SHORT)
  59                         printf("%s\n", refname);
  60                 else if (data->format == REPLACE_FORMAT_MEDIUM)
  61                         printf("%s -> %s\n", refname, oid_to_hex(oid));
  62                 else { /* data->format == REPLACE_FORMAT_LONG */
  63                         struct object_id object;
  64                         enum object_type obj_type, repl_type;
  65
  66                         if (repo_get_oid(data->repo, refname, &object))
  67                                 return error(_("failed to resolve '%s' as a valid ref"), refname);
  68
  69                         obj_type = oid_object_info(data->repo, &object, NULL);
  70                         repl_type = oid_object_info(data->repo, oid, NULL);
  71
  72                         printf("%s (%s) -> %s (%s)\n", refname, type_name(obj_type),
  73                                oid_to_hex(oid), type_name(repl_type));
  74                 }
  75         }
  76
  77         return 0;
  78 }
  79
  80 static int list_replace_refs(const char *pattern, const char *format)
  81 {
  82         struct show_data data;
  83
  84         data.repo = the_repository;
  85         if (!pattern)
  86                 pattern = "*";
  87         data.pattern = pattern;
  88
  89         if (format == NULL || *format == '\0' || !strcmp(format, "short"))
  90                 data.format = REPLACE_FORMAT_SHORT;
  91         else if (!strcmp(format, "medium"))
  92                 data.format = REPLACE_FORMAT_MEDIUM;
  93         else if (!strcmp(format, "long"))
  94                 data.format = REPLACE_FORMAT_LONG;
  95         /*
  96          * Please update _git_replace() in git-completion.bash when
  97          * you add new format
  98          */
  99         else
 100                 return error(_("invalid replace format '%s'\n"
 101                                "valid formats are 'short', 'medium' and 'long'"),
 102                              format);
 103
 104         refs_for_each_replace_ref(get_main_ref_store(the_repository),
 105                                   show_reference, (void *)&data);
 106
 107         return 0;
 108 }
 109
 110 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
 111                                     const struct object_id *oid);
 112
 113 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
 114 {
 115         const char **p, *full_hex;
 116         struct strbuf ref = STRBUF_INIT;
 117         size_t base_len;
 118         int had_error = 0;
 119         struct object_id oid;
 120         const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
 121
 122         strbuf_addstr(&ref, git_replace_ref_base);
 123         base_len = ref.len;
 124
 125         for (p = argv; *p; p++) {
 126                 if (repo_get_oid(the_repository, *p, &oid)) {
 127                         error("failed to resolve '%s' as a valid ref", *p);
 128                         had_error = 1;
 129                         continue;
 130                 }
 131
 132                 strbuf_setlen(&ref, base_len);
 133                 strbuf_addstr(&ref, oid_to_hex(&oid));
 134                 full_hex = ref.buf + base_len;
 135
 136                 if (refs_read_ref(get_main_ref_store(the_repository), ref.buf, &oid)) {
 137                         error(_("replace ref '%s' not found"), full_hex);
 138                         had_error = 1;
 139                         continue;
 140                 }
 141                 if (fn(full_hex, ref.buf, &oid))
 142                         had_error = 1;
 143         }
 144         strbuf_release(&ref);
 145         return had_error;
 146 }
 147
 148 static int delete_replace_ref(const char *name, const char *ref,
 149                               const struct object_id *oid)
 150 {
 151         if (refs_delete_ref(get_main_ref_store(the_repository), NULL, ref, oid, 0))
 152                 return 1;
 153         printf_ln(_("Deleted replace ref '%s'"), name);
 154         return 0;
 155 }
 156
 157 static int check_ref_valid(struct object_id *object,
 158                             struct object_id *prev,
 159                             struct strbuf *ref,
 160                             int force)
 161 {
 162         const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
 163
 164         strbuf_reset(ref);
 165         strbuf_addf(ref, "%s%s", git_replace_ref_base, oid_to_hex(object));
 166         if (check_refname_format(ref->buf, 0))
 167                 return error(_("'%s' is not a valid ref name"), ref->buf);
 168
 169         if (refs_read_ref(get_main_ref_store(the_repository), ref->buf, prev))
 170                 oidclr(prev);
 171         else if (!force)
 172                 return error(_("replace ref '%s' already exists"), ref->buf);
 173         return 0;
 174 }
 175
 176 static int replace_object_oid(const char *object_ref,
 177                                struct object_id *object,
 178                                const char *replace_ref,
 179                                struct object_id *repl,
 180                                int force)
 181 {
 182         struct object_id prev;
 183         enum object_type obj_type, repl_type;
 184         struct strbuf ref = STRBUF_INIT;
 185         struct ref_transaction *transaction;
 186         struct strbuf err = STRBUF_INIT;
 187         int res = 0;
 188
 189         obj_type = oid_object_info(the_repository, object, NULL);
 190         repl_type = oid_object_info(the_repository, repl, NULL);
 191         if (!force && obj_type != repl_type)
 192                 return error(_("Objects must be of the same type.\n"
 193                                "'%s' points to a replaced object of type '%s'\n"
 194                                "while '%s' points to a replacement object of "
 195                                "type '%s'."),
 196                              object_ref, type_name(obj_type),
 197                              replace_ref, type_name(repl_type));
 198
 199         if (check_ref_valid(object, &prev, &ref, force)) {
 200                 strbuf_release(&ref);
 201                 return -1;
 202         }
 203
 204         transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
 205                                                   &err);
 206         if (!transaction ||
 207             ref_transaction_update(transaction, ref.buf, repl, &prev,
 208                                    NULL, NULL, 0, NULL, &err) ||
 209             ref_transaction_commit(transaction, &err))
 210                 res = error("%s", err.buf);
 211
 212         ref_transaction_free(transaction);
 213         strbuf_release(&ref);
 214         return res;
 215 }
 216
 217 static int replace_object(const char *object_ref, const char *replace_ref, int force)
 218 {
 219         struct object_id object, repl;
 220
 221         if (repo_get_oid(the_repository, object_ref, &object))
 222                 return error(_("failed to resolve '%s' as a valid ref"),
 223                              object_ref);
 224         if (repo_get_oid(the_repository, replace_ref, &repl))
 225                 return error(_("failed to resolve '%s' as a valid ref"),
 226                              replace_ref);
 227
 228         return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
 229 }
 230
 231 /*
 232  * Write the contents of the object named by "sha1" to the file "filename".
 233  * If "raw" is true, then the object's raw contents are printed according to
 234  * "type". Otherwise, we pretty-print the contents for human editing.
 235  */
 236 static int export_object(const struct object_id *oid, enum object_type type,
 237                           int raw, const char *filename)
 238 {
 239         struct child_process cmd = CHILD_PROCESS_INIT;
 240         int fd;
 241
 242         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 243         if (fd < 0)
 244                 return error_errno(_("unable to open %s for writing"), filename);
 245
 246         strvec_push(&cmd.args, "--no-replace-objects");
 247         strvec_push(&cmd.args, "cat-file");
 248         if (raw)
 249                 strvec_push(&cmd.args, type_name(type));
 250         else
 251                 strvec_push(&cmd.args, "-p");
 252         strvec_push(&cmd.args, oid_to_hex(oid));
 253         cmd.git_cmd = 1;
 254         cmd.out = fd;
 255
 256         if (run_command(&cmd))
 257                 return error(_("cat-file reported failure"));
 258         return 0;
 259 }
 260
 261 /*
 262  * Read a previously-exported (and possibly edited) object back from "filename",
 263  * interpreting it as "type", and writing the result to the object database.
 264  * The sha1 of the written object is returned via sha1.
 265  */
 266 static int import_object(struct object_id *oid, enum object_type type,
 267                           int raw, const char *filename)
 268 {
 269         int fd;
 270
 271         fd = open(filename, O_RDONLY);
 272         if (fd < 0)
 273                 return error_errno(_("unable to open %s for reading"), filename);
 274
 275         if (!raw && type == OBJ_TREE) {
 276                 struct child_process cmd = CHILD_PROCESS_INIT;
 277                 struct strbuf result = STRBUF_INIT;
 278
 279                 strvec_push(&cmd.args, "mktree");
 280                 cmd.git_cmd = 1;
 281                 cmd.in = fd;
 282                 cmd.out = -1;
 283
 284                 if (start_command(&cmd)) {
 285                         close(fd);
 286                         return error(_("unable to spawn mktree"));
 287                 }
 288
 289                 if (strbuf_read(&result, cmd.out, the_hash_algo->hexsz + 1) < 0) {
 290                         error_errno(_("unable to read from mktree"));
 291                         close(fd);
 292                         close(cmd.out);
 293                         return -1;
 294                 }
 295                 close(cmd.out);
 296
 297                 if (finish_command(&cmd)) {
 298                         strbuf_release(&result);
 299                         return error(_("mktree reported failure"));
 300                 }
 301                 if (get_oid_hex(result.buf, oid) < 0) {
 302                         strbuf_release(&result);
 303                         return error(_("mktree did not return an object name"));
 304                 }
 305
 306                 strbuf_release(&result);
 307         } else {
 308                 struct stat st;
 309                 int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
 310
 311                 if (fstat(fd, &st) < 0) {
 312                         error_errno(_("unable to fstat %s"), filename);
 313                         close(fd);
 314                         return -1;
 315                 }
 316                 if (index_fd(the_repository->index, oid, fd, &st, type, NULL, flags) < 0)
 317                         return error(_("unable to write object to database"));
 318                 /* index_fd close()s fd for us */
 319         }
 320
 321         /*
 322          * No need to close(fd) here; both run-command and index-fd
 323          * will have done it for us.
 324          */
 325         return 0;
 326 }
 327
 328 static int edit_and_replace(const char *object_ref, int force, int raw)
 329 {
 330         char *tmpfile;
 331         enum object_type type;
 332         struct object_id old_oid, new_oid, prev;
 333         struct strbuf ref = STRBUF_INIT;
 334
 335         if (repo_get_oid(the_repository, object_ref, &old_oid) < 0)
 336                 return error(_("not a valid object name: '%s'"), object_ref);
 337
 338         type = oid_object_info(the_repository, &old_oid, NULL);
 339         if (type < 0)
 340                 return error(_("unable to get object type for %s"),
 341                              oid_to_hex(&old_oid));
 342
 343         if (check_ref_valid(&old_oid, &prev, &ref, force)) {
 344                 strbuf_release(&ref);
 345                 return -1;
 346         }
 347         strbuf_release(&ref);
 348
 349         tmpfile = git_pathdup("REPLACE_EDITOBJ");
 350         if (export_object(&old_oid, type, raw, tmpfile)) {
 351                 free(tmpfile);
 352                 return -1;
 353         }
 354         if (launch_editor(tmpfile, NULL, NULL) < 0) {
 355                 free(tmpfile);
 356                 return error(_("editing object file failed"));
 357         }
 358         if (import_object(&new_oid, type, raw, tmpfile)) {
 359                 free(tmpfile);
 360                 return -1;
 361         }
 362         free(tmpfile);
 363
 364         if (oideq(&old_oid, &new_oid))
 365                 return error(_("new object is the same as the old one: '%s'"), oid_to_hex(&old_oid));
 366
 367         return replace_object_oid(object_ref, &old_oid, "replacement", &new_oid, force);
 368 }
 369
 370 static int replace_parents(struct strbuf *buf, int argc, const char **argv)
 371 {
 372         struct strbuf new_parents = STRBUF_INIT;
 373         const char *parent_start, *parent_end;
 374         int i;
 375         const unsigned hexsz = the_hash_algo->hexsz;
 376
 377         /* find existing parents */
 378         parent_start = buf->buf;
 379         parent_start += hexsz + 6; /* "tree " + "hex sha1" + "\n" */
 380         parent_end = parent_start;
 381
 382         while (starts_with(parent_end, "parent "))
 383                 parent_end += hexsz + 8; /* "parent " + "hex sha1" + "\n" */
 384
 385         /* prepare new parents */
 386         for (i = 0; i < argc; i++) {
 387                 struct object_id oid;
 388                 struct commit *commit;
 389
 390                 if (repo_get_oid(the_repository, argv[i], &oid) < 0) {
 391                         strbuf_release(&new_parents);
 392                         return error(_("not a valid object name: '%s'"),
 393                                      argv[i]);
 394                 }
 395                 commit = lookup_commit_reference(the_repository, &oid);
 396                 if (!commit) {
 397                         strbuf_release(&new_parents);
 398                         return error(_("could not parse %s as a commit"), argv[i]);
 399                 }
 400                 strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&commit->object.oid));
 401         }
 402
 403         /* replace existing parents with new ones */
 404         strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
 405                       new_parents.buf, new_parents.len);
 406
 407         strbuf_release(&new_parents);
 408         return 0;
 409 }
 410
 411 struct check_mergetag_data {
 412         int argc;
 413         const char **argv;
 414 };
 415
 416 static int check_one_mergetag(struct commit *commit UNUSED,
 417                                struct commit_extra_header *extra,
 418                                void *data)
 419 {
 420         struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
 421         const char *ref = mergetag_data->argv[0];
 422         struct object_id tag_oid;
 423         struct tag *tag;
 424         int i;
 425
 426         hash_object_file(the_hash_algo, extra->value, extra->len,
 427                          OBJ_TAG, &tag_oid);
 428         tag = lookup_tag(the_repository, &tag_oid);
 429         if (!tag)
 430                 return error(_("bad mergetag in commit '%s'"), ref);
 431         if (parse_tag_buffer(the_repository, tag, extra->value, extra->len))
 432                 return error(_("malformed mergetag in commit '%s'"), ref);
 433
 434         /* iterate over new parents */
 435         for (i = 1; i < mergetag_data->argc; i++) {
 436                 struct object_id oid;
 437                 if (repo_get_oid(the_repository, mergetag_data->argv[i], &oid) < 0)
 438                         return error(_("not a valid object name: '%s'"),
 439                                      mergetag_data->argv[i]);
 440                 if (oideq(get_tagged_oid(tag), &oid))
 441                         return 0; /* found */
 442         }
 443
 444         return error(_("original commit '%s' contains mergetag '%s' that is "
 445                        "discarded; use --edit instead of --graft"), ref,
 446                      oid_to_hex(&tag_oid));
 447 }
 448
 449 static int check_mergetags(struct commit *commit, int argc, const char **argv)
 450 {
 451         struct check_mergetag_data mergetag_data;
 452
 453         mergetag_data.argc = argc;
 454         mergetag_data.argv = argv;
 455         return for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
 456 }
 457
 458 static int create_graft(int argc, const char **argv, int force, int gentle)
 459 {
 460         struct object_id old_oid, new_oid;
 461         const char *old_ref = argv[0];
 462         struct commit *commit;
 463         struct strbuf buf = STRBUF_INIT;
 464         const char *buffer;
 465         unsigned long size;
 466
 467         if (repo_get_oid(the_repository, old_ref, &old_oid) < 0)
 468                 return error(_("not a valid object name: '%s'"), old_ref);
 469         commit = lookup_commit_reference(the_repository, &old_oid);
 470         if (!commit)
 471                 return error(_("could not parse %s"), old_ref);
 472
 473         buffer = repo_get_commit_buffer(the_repository, commit, &size);
 474         strbuf_add(&buf, buffer, size);
 475         repo_unuse_commit_buffer(the_repository, commit, buffer);
 476
 477         if (replace_parents(&buf, argc - 1, &argv[1]) < 0) {
 478                 strbuf_release(&buf);
 479                 return -1;
 480         }
 481
 482         if (remove_signature(&buf)) {
 483                 warning(_("the original commit '%s' has a gpg signature"), old_ref);
 484                 warning(_("the signature will be removed in the replacement commit!"));
 485         }
 486
 487         if (check_mergetags(commit, argc, argv)) {
 488                 strbuf_release(&buf);
 489                 return -1;
 490         }
 491
 492         if (write_object_file(buf.buf, buf.len, OBJ_COMMIT, &new_oid)) {
 493                 strbuf_release(&buf);
 494                 return error(_("could not write replacement commit for: '%s'"),
 495                              old_ref);
 496         }
 497
 498         strbuf_release(&buf);
 499
 500         if (oideq(&commit->object.oid, &new_oid)) {
 501                 if (gentle) {
 502                         warning(_("graft for '%s' unnecessary"),
 503                                 oid_to_hex(&commit->object.oid));
 504                         return 0;
 505                 }
 506                 return error(_("new commit is the same as the old one: '%s'"),
 507                              oid_to_hex(&commit->object.oid));
 508         }
 509
 510         return replace_object_oid(old_ref, &commit->object.oid,
 511                                   "replacement", &new_oid, force);
 512 }
 513
 514 static int convert_graft_file(int force)
 515 {
 516         const char *graft_file = get_graft_file(the_repository);
 517         FILE *fp = fopen_or_warn(graft_file, "r");
 518         struct strbuf buf = STRBUF_INIT, err = STRBUF_INIT;
 519         struct strvec args = STRVEC_INIT;
 520
 521         if (!fp)
 522                 return -1;
 523
 524         no_graft_file_deprecated_advice = 1;
 525         while (strbuf_getline(&buf, fp) != EOF) {
 526                 if (*buf.buf == '#')
 527                         continue;
 528
 529                 strvec_split(&args, buf.buf);
 530                 if (args.nr && create_graft(args.nr, args.v, force, 1))
 531                         strbuf_addf(&err, "\n\t%s", buf.buf);
 532                 strvec_clear(&args);
 533         }
 534         fclose(fp);
 535
 536         strbuf_release(&buf);
 537
 538         if (!err.len)
 539                 return unlink_or_warn(graft_file);
 540
 541         warning(_("could not convert the following graft(s):\n%s"), err.buf);
 542         strbuf_release(&err);
 543
 544         return -1;
 545 }
 546
 547 int cmd_replace(int argc, const char **argv, const char *prefix)
 548 {
 549         int force = 0;
 550         int raw = 0;
 551         const char *format = NULL;
 552         enum {
 553                 MODE_UNSPECIFIED = 0,
 554                 MODE_LIST,
 555                 MODE_DELETE,
 556                 MODE_EDIT,
 557                 MODE_GRAFT,
 558                 MODE_CONVERT_GRAFT_FILE,
 559                 MODE_REPLACE
 560         } cmdmode = MODE_UNSPECIFIED;
 561         struct option options[] = {
 562                 OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
 563                 OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
 564                 OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
 565                 OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
 566                 OPT_CMDMODE(0, "convert-graft-file", &cmdmode, N_("convert existing graft file"), MODE_CONVERT_GRAFT_FILE),
 567                 OPT_BOOL_F('f', "force", &force, N_("replace the ref if it exists"),
 568                            PARSE_OPT_NOCOMPLETE),
 569                 OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
 570                 OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
 571                 OPT_END()
 572         };
 573
 574         disable_replace_refs();
 575         git_config(git_default_config, NULL);
 576
 577         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 578
 579         if (!cmdmode)
 580                 cmdmode = argc ? MODE_REPLACE : MODE_LIST;
 581
 582         if (format && cmdmode != MODE_LIST)
 583                 usage_msg_opt(_("--format cannot be used when not listing"),
 584                               git_replace_usage, options);
 585
 586         if (force &&
 587             cmdmode != MODE_REPLACE &&
 588             cmdmode != MODE_EDIT &&
 589             cmdmode != MODE_GRAFT &&
 590             cmdmode != MODE_CONVERT_GRAFT_FILE)
 591                 usage_msg_opt(_("-f only makes sense when writing a replacement"),
 592                               git_replace_usage, options);
 593
 594         if (raw && cmdmode != MODE_EDIT)
 595                 usage_msg_opt(_("--raw only makes sense with --edit"),
 596                               git_replace_usage, options);
 597
 598         switch (cmdmode) {
 599         case MODE_DELETE:
 600                 if (argc < 1)
 601                         usage_msg_opt(_("-d needs at least one argument"),
 602                                       git_replace_usage, options);
 603                 return for_each_replace_name(argv, delete_replace_ref);
 604
 605         case MODE_REPLACE:
 606                 if (argc != 2)
 607                         usage_msg_opt(_("bad number of arguments"),
 608                                       git_replace_usage, options);
 609                 return replace_object(argv[0], argv[1], force);
 610
 611         case MODE_EDIT:
 612                 if (argc != 1)
 613                         usage_msg_opt(_("-e needs exactly one argument"),
 614                                       git_replace_usage, options);
 615                 return edit_and_replace(argv[0], force, raw);
 616
 617         case MODE_GRAFT:
 618                 if (argc < 1)
 619                         usage_msg_opt(_("-g needs at least one argument"),
 620                                       git_replace_usage, options);
 621                 return create_graft(argc, argv, force, 0);
 622
 623         case MODE_CONVERT_GRAFT_FILE:
 624                 if (argc != 0)
 625                         usage_msg_opt(_("--convert-graft-file takes no argument"),
 626                                       git_replace_usage, options);
 627                 return !!convert_graft_file(force);
 628
 629         case MODE_LIST:
 630                 if (argc > 1)
 631                         usage_msg_opt(_("only one pattern can be given with -l"),
 632                                       git_replace_usage, options);
 633                 return list_replace_refs(argv[0], format);
 634
 635         default:
 636                 BUG("invalid cmdmode %d", (int)cmdmode);
 637         }
 638 }