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 #define USE_THE_REPOSITORY_VARIABLE
  11 #include "builtin.h"
  12 #include "config.h"
  13 #include "editor.h"
  14 #include "gettext.h"
  15 #include "hex.h"
  16 #include "refs.h"
  17 #include "parse-options.h"
  18 #include "path.h"
  19 #include "run-command.h"
  20 #include "object-file.h"
  21 #include "object-name.h"
  22 #include "object-store-ll.h"
  23 #include "replace-object.h"
  24 #include "tag.h"
  25 #include "wildmatch.h"
  26
  27 static const char * const git_replace_usage[] = {
  28         N_("git replace [-f] <object> <replacement>"),
  29         N_("git replace [-f] --edit <object>"),
  30         N_("git replace [-f] --graft <commit> [<parent>...]"),
  31         "git replace [-f] --convert-graft-file",
  32         N_("git replace -d <object>..."),
  33         N_("git replace [--format=<format>] [-l [<pattern>]]"),
  34         NULL
  35 };
  36
  37 enum replace_format {
  38         REPLACE_FORMAT_SHORT,
  39         REPLACE_FORMAT_MEDIUM,
  40         REPLACE_FORMAT_LONG
  41 };
  42
  43 struct show_data {
  44         struct repository *repo;
  45         const char *pattern;
  46         enum replace_format format;
  47 };
  48
  49 static int show_reference(const char *refname,
  50                           const char *referent UNUSED,
  51                           const struct object_id *oid,
  52                           int flag UNUSED, void *cb_data)
  53 {
  54         struct show_data *data = cb_data;
  55
  56         if (!wildmatch(data->pattern, refname, 0)) {
  57                 if (data->format == REPLACE_FORMAT_SHORT)
  58                         printf("%s\n", refname);
  59                 else if (data->format == REPLACE_FORMAT_MEDIUM)
  60                         printf("%s -> %s\n", refname, oid_to_hex(oid));
  61                 else { /* data->format == REPLACE_FORMAT_LONG */
  62                         struct object_id object;
  63                         enum object_type obj_type, repl_type;
  64
  65                         if (repo_get_oid(data->repo, refname, &object))
  66                                 return error(_("failed to resolve '%s' as a valid ref"), refname);
  67
  68                         obj_type = oid_object_info(data->repo, &object, NULL);
  69                         repl_type = oid_object_info(data->repo, oid, NULL);
  70
  71                         printf("%s (%s) -> %s (%s)\n", refname, type_name(obj_type),
  72                                oid_to_hex(oid), type_name(repl_type));
  73                 }
  74         }
  75
  76         return 0;
  77 }
  78
  79 static int list_replace_refs(const char *pattern, const char *format)
  80 {
  81         struct show_data data;
  82
  83         data.repo = the_repository;
  84         if (!pattern)
  85                 pattern = "*";
  86         data.pattern = pattern;
  87
  88         if (format == NULL || *format == '\0' || !strcmp(format, "short"))
  89                 data.format = REPLACE_FORMAT_SHORT;
  90         else if (!strcmp(format, "medium"))
  91                 data.format = REPLACE_FORMAT_MEDIUM;
  92         else if (!strcmp(format, "long"))
  93                 data.format = REPLACE_FORMAT_LONG;
  94         /*
  95          * Please update _git_replace() in git-completion.bash when
  96          * you add new format
  97          */
  98         else
  99                 return error(_("invalid replace format '%s'\n"
 100                                "valid formats are 'short', 'medium' and 'long'"),
 101                              format);
 102
 103         refs_for_each_replace_ref(get_main_ref_store(the_repository),
 104                                   show_reference, (void *)&data);
 105
 106         return 0;
 107 }
 108
 109 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
 110                                     const struct object_id *oid);
 111
 112 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
 113 {
 114         const char **p, *full_hex;
 115         struct strbuf ref = STRBUF_INIT;
 116         size_t base_len;
 117         int had_error = 0;
 118         struct object_id oid;
 119         const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
 120
 121         strbuf_addstr(&ref, git_replace_ref_base);
 122         base_len = ref.len;
 123
 124         for (p = argv; *p; p++) {
 125                 if (repo_get_oid(the_repository, *p, &oid)) {
 126                         error("failed to resolve '%s' as a valid ref", *p);
 127                         had_error = 1;
 128                         continue;
 129                 }
 130
 131                 strbuf_setlen(&ref, base_len);
 132                 strbuf_addstr(&ref, oid_to_hex(&oid));
 133                 full_hex = ref.buf + base_len;
 134
 135                 if (refs_read_ref(get_main_ref_store(the_repository), ref.buf, &oid)) {
 136                         error(_("replace ref '%s' not found"), full_hex);
 137                         had_error = 1;
 138                         continue;
 139                 }
 140                 if (fn(full_hex, ref.buf, &oid))
 141                         had_error = 1;
 142         }
 143         strbuf_release(&ref);
 144         return had_error;
 145 }
 146
 147 static int delete_replace_ref(const char *name, const char *ref,
 148                               const struct object_id *oid)
 149 {
 150         if (refs_delete_ref(get_main_ref_store(the_repository), NULL, ref, oid, 0))
 151                 return 1;
 152         printf_ln(_("Deleted replace ref '%s'"), name);
 153         return 0;
 154 }
 155
 156 static int check_ref_valid(struct object_id *object,
 157                             struct object_id *prev,
 158                             struct strbuf *ref,
 159                             int force)
 160 {
 161         const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
 162
 163         strbuf_reset(ref);
 164         strbuf_addf(ref, "%s%s", git_replace_ref_base, oid_to_hex(object));
 165         if (check_refname_format(ref->buf, 0))
 166                 return error(_("'%s' is not a valid ref name"), ref->buf);
 167
 168         if (refs_read_ref(get_main_ref_store(the_repository), ref->buf, prev))
 169                 oidclr(prev, the_repository->hash_algo);
 170         else if (!force)
 171                 return error(_("replace ref '%s' already exists"), ref->buf);
 172         return 0;
 173 }
 174
 175 static int replace_object_oid(const char *object_ref,
 176                                struct object_id *object,
 177                                const char *replace_ref,
 178                                struct object_id *repl,
 179                                int force)
 180 {
 181         struct object_id prev;
 182         enum object_type obj_type, repl_type;
 183         struct strbuf ref = STRBUF_INIT;
 184         struct ref_transaction *transaction;
 185         struct strbuf err = STRBUF_INIT;
 186         int res = 0;
 187
 188         obj_type = oid_object_info(the_repository, object, NULL);
 189         repl_type = oid_object_info(the_repository, repl, NULL);
 190         if (!force && obj_type != repl_type)
 191                 return error(_("Objects must be of the same type.\n"
 192                                "'%s' points to a replaced object of type '%s'\n"
 193                                "while '%s' points to a replacement object of "
 194                                "type '%s'."),
 195                              object_ref, type_name(obj_type),
 196                              replace_ref, type_name(repl_type));
 197
 198         if (check_ref_valid(object, &prev, &ref, force)) {
 199                 strbuf_release(&ref);
 200                 return -1;
 201         }
 202
 203         transaction = ref_store_transaction_begin(get_main_ref_store(the_repository),
 204                                                   &err);
 205         if (!transaction ||
 206             ref_transaction_update(transaction, ref.buf, repl, &prev,
 207                                    NULL, NULL, 0, NULL, &err) ||
 208             ref_transaction_commit(transaction, &err))
 209                 res = error("%s", err.buf);
 210
 211         ref_transaction_free(transaction);
 212         strbuf_release(&ref);
 213         return res;
 214 }
 215
 216 static int replace_object(const char *object_ref, const char *replace_ref, int force)
 217 {
 218         struct object_id object, repl;
 219
 220         if (repo_get_oid(the_repository, object_ref, &object))
 221                 return error(_("failed to resolve '%s' as a valid ref"),
 222                              object_ref);
 223         if (repo_get_oid(the_repository, replace_ref, &repl))
 224                 return error(_("failed to resolve '%s' as a valid ref"),
 225                              replace_ref);
 226
 227         return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
 228 }
 229
 230 /*
 231  * Write the contents of the object named by "sha1" to the file "filename".
 232  * If "raw" is true, then the object's raw contents are printed according to
 233  * "type". Otherwise, we pretty-print the contents for human editing.
 234  */
 235 static int export_object(const struct object_id *oid, enum object_type type,
 236                           int raw, const char *filename)
 237 {
 238         struct child_process cmd = CHILD_PROCESS_INIT;
 239         int fd;
 240
 241         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 242         if (fd < 0)
 243                 return error_errno(_("unable to open %s for writing"), filename);
 244
 245         strvec_push(&cmd.args, "--no-replace-objects");
 246         strvec_push(&cmd.args, "cat-file");
 247         if (raw)
 248                 strvec_push(&cmd.args, type_name(type));
 249         else
 250                 strvec_push(&cmd.args, "-p");
 251         strvec_push(&cmd.args, oid_to_hex(oid));
 252         cmd.git_cmd = 1;
 253         cmd.out = fd;
 254
 255         if (run_command(&cmd))
 256                 return error(_("cat-file reported failure"));
 257         return 0;
 258 }
 259
 260 /*
 261  * Read a previously-exported (and possibly edited) object back from "filename",
 262  * interpreting it as "type", and writing the result to the object database.
 263  * The sha1 of the written object is returned via sha1.
 264  */
 265 static int import_object(struct object_id *oid, enum object_type type,
 266                           int raw, const char *filename)
 267 {
 268         int fd;
 269
 270         fd = open(filename, O_RDONLY);
 271         if (fd < 0)
 272                 return error_errno(_("unable to open %s for reading"), filename);
 273
 274         if (!raw && type == OBJ_TREE) {
 275                 struct child_process cmd = CHILD_PROCESS_INIT;
 276                 struct strbuf result = STRBUF_INIT;
 277
 278                 strvec_push(&cmd.args, "mktree");
 279                 cmd.git_cmd = 1;
 280                 cmd.in = fd;
 281                 cmd.out = -1;
 282
 283                 if (start_command(&cmd)) {
 284                         close(fd);
 285                         return error(_("unable to spawn mktree"));
 286                 }
 287
 288                 if (strbuf_read(&result, cmd.out, the_hash_algo->hexsz + 1) < 0) {
 289                         error_errno(_("unable to read from mktree"));
 290                         close(fd);
 291                         close(cmd.out);
 292                         return -1;
 293                 }
 294                 close(cmd.out);
 295
 296                 if (finish_command(&cmd)) {
 297                         strbuf_release(&result);
 298                         return error(_("mktree reported failure"));
 299                 }
 300                 if (get_oid_hex(result.buf, oid) < 0) {
 301                         strbuf_release(&result);
 302                         return error(_("mktree did not return an object name"));
 303                 }
 304
 305                 strbuf_release(&result);
 306         } else {
 307                 struct stat st;
 308                 int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
 309
 310                 if (fstat(fd, &st) < 0) {
 311                         error_errno(_("unable to fstat %s"), filename);
 312                         close(fd);
 313                         return -1;
 314                 }
 315                 if (index_fd(the_repository->index, oid, fd, &st, type, NULL, flags) < 0)
 316                         return error(_("unable to write object to database"));
 317                 /* index_fd close()s fd for us */
 318         }
 319
 320         /*
 321          * No need to close(fd) here; both run-command and index-fd
 322          * will have done it for us.
 323          */
 324         return 0;
 325 }
 326
 327 static int edit_and_replace(const char *object_ref, int force, int raw)
 328 {
 329         char *tmpfile;
 330         enum object_type type;
 331         struct object_id old_oid, new_oid, prev;
 332         struct strbuf ref = STRBUF_INIT;
 333
 334         if (repo_get_oid(the_repository, object_ref, &old_oid) < 0)
 335                 return error(_("not a valid object name: '%s'"), object_ref);
 336
 337         type = oid_object_info(the_repository, &old_oid, NULL);
 338         if (type < 0)
 339                 return error(_("unable to get object type for %s"),
 340                              oid_to_hex(&old_oid));
 341
 342         if (check_ref_valid(&old_oid, &prev, &ref, force)) {
 343                 strbuf_release(&ref);
 344                 return -1;
 345         }
 346         strbuf_release(&ref);
 347
 348         tmpfile = git_pathdup("REPLACE_EDITOBJ");
 349         if (export_object(&old_oid, type, raw, tmpfile)) {
 350                 free(tmpfile);
 351                 return -1;
 352         }
 353         if (launch_editor(tmpfile, NULL, NULL) < 0) {
 354                 free(tmpfile);
 355                 return error(_("editing object file failed"));
 356         }
 357         if (import_object(&new_oid, type, raw, tmpfile)) {
 358                 free(tmpfile);
 359                 return -1;
 360         }
 361         free(tmpfile);
 362
 363         if (oideq(&old_oid, &new_oid))
 364                 return error(_("new object is the same as the old one: '%s'"), oid_to_hex(&old_oid));
 365
 366         return replace_object_oid(object_ref, &old_oid, "replacement", &new_oid, force);
 367 }
 368
 369 static int replace_parents(struct strbuf *buf, int argc, const char **argv)
 370 {
 371         struct strbuf new_parents = STRBUF_INIT;
 372         const char *parent_start, *parent_end;
 373         int i;
 374         const unsigned hexsz = the_hash_algo->hexsz;
 375
 376         /* find existing parents */
 377         parent_start = buf->buf;
 378         parent_start += hexsz + 6; /* "tree " + "hex sha1" + "\n" */
 379         parent_end = parent_start;
 380
 381         while (starts_with(parent_end, "parent "))
 382                 parent_end += hexsz + 8; /* "parent " + "hex sha1" + "\n" */
 383
 384         /* prepare new parents */
 385         for (i = 0; i < argc; i++) {
 386                 struct object_id oid;
 387                 struct commit *commit;
 388
 389                 if (repo_get_oid(the_repository, argv[i], &oid) < 0) {
 390                         strbuf_release(&new_parents);
 391                         return error(_("not a valid object name: '%s'"),
 392                                      argv[i]);
 393                 }
 394                 commit = lookup_commit_reference(the_repository, &oid);
 395                 if (!commit) {
 396                         strbuf_release(&new_parents);
 397                         return error(_("could not parse %s as a commit"), argv[i]);
 398                 }
 399                 strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&commit->object.oid));
 400         }
 401
 402         /* replace existing parents with new ones */
 403         strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
 404                       new_parents.buf, new_parents.len);
 405
 406         strbuf_release(&new_parents);
 407         return 0;
 408 }
 409
 410 struct check_mergetag_data {
 411         int argc;
 412         const char **argv;
 413 };
 414
 415 static int check_one_mergetag(struct commit *commit UNUSED,
 416                                struct commit_extra_header *extra,
 417                                void *data)
 418 {
 419         struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
 420         const char *ref = mergetag_data->argv[0];
 421         struct object_id tag_oid;
 422         struct tag *tag;
 423         int i;
 424
 425         hash_object_file(the_hash_algo, extra->value, extra->len,
 426                          OBJ_TAG, &tag_oid);
 427         tag = lookup_tag(the_repository, &tag_oid);
 428         if (!tag)
 429                 return error(_("bad mergetag in commit '%s'"), ref);
 430         if (parse_tag_buffer(the_repository, tag, extra->value, extra->len))
 431                 return error(_("malformed mergetag in commit '%s'"), ref);
 432
 433         /* iterate over new parents */
 434         for (i = 1; i < mergetag_data->argc; i++) {
 435                 struct object_id oid;
 436                 if (repo_get_oid(the_repository, mergetag_data->argv[i], &oid) < 0)
 437                         return error(_("not a valid object name: '%s'"),
 438                                      mergetag_data->argv[i]);
 439                 if (oideq(get_tagged_oid(tag), &oid))
 440                         return 0; /* found */
 441         }
 442
 443         return error(_("original commit '%s' contains mergetag '%s' that is "
 444                        "discarded; use --edit instead of --graft"), ref,
 445                      oid_to_hex(&tag_oid));
 446 }
 447
 448 static int check_mergetags(struct commit *commit, int argc, const char **argv)
 449 {
 450         struct check_mergetag_data mergetag_data;
 451
 452         mergetag_data.argc = argc;
 453         mergetag_data.argv = argv;
 454         return for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
 455 }
 456
 457 static int create_graft(int argc, const char **argv, int force, int gentle)
 458 {
 459         struct object_id old_oid, new_oid;
 460         const char *old_ref = argv[0];
 461         struct commit *commit;
 462         struct strbuf buf = STRBUF_INIT;
 463         const char *buffer;
 464         unsigned long size;
 465
 466         if (repo_get_oid(the_repository, old_ref, &old_oid) < 0)
 467                 return error(_("not a valid object name: '%s'"), old_ref);
 468         commit = lookup_commit_reference(the_repository, &old_oid);
 469         if (!commit)
 470                 return error(_("could not parse %s"), old_ref);
 471
 472         buffer = repo_get_commit_buffer(the_repository, commit, &size);
 473         strbuf_add(&buf, buffer, size);
 474         repo_unuse_commit_buffer(the_repository, commit, buffer);
 475
 476         if (replace_parents(&buf, argc - 1, &argv[1]) < 0) {
 477                 strbuf_release(&buf);
 478                 return -1;
 479         }
 480
 481         if (remove_signature(&buf)) {
 482                 warning(_("the original commit '%s' has a gpg signature"), old_ref);
 483                 warning(_("the signature will be removed in the replacement commit!"));
 484         }
 485
 486         if (check_mergetags(commit, argc, argv)) {
 487                 strbuf_release(&buf);
 488                 return -1;
 489         }
 490
 491         if (write_object_file(buf.buf, buf.len, OBJ_COMMIT, &new_oid)) {
 492                 strbuf_release(&buf);
 493                 return error(_("could not write replacement commit for: '%s'"),
 494                              old_ref);
 495         }
 496
 497         strbuf_release(&buf);
 498
 499         if (oideq(&commit->object.oid, &new_oid)) {
 500                 if (gentle) {
 501                         warning(_("graft for '%s' unnecessary"),
 502                                 oid_to_hex(&commit->object.oid));
 503                         return 0;
 504                 }
 505                 return error(_("new commit is the same as the old one: '%s'"),
 506                              oid_to_hex(&commit->object.oid));
 507         }
 508
 509         return replace_object_oid(old_ref, &commit->object.oid,
 510                                   "replacement", &new_oid, force);
 511 }
 512
 513 static int convert_graft_file(int force)
 514 {
 515         const char *graft_file = repo_get_graft_file(the_repository);
 516         FILE *fp = fopen_or_warn(graft_file, "r");
 517         struct strbuf buf = STRBUF_INIT, err = STRBUF_INIT;
 518         struct strvec args = STRVEC_INIT;
 519
 520         if (!fp)
 521                 return -1;
 522
 523         no_graft_file_deprecated_advice = 1;
 524         while (strbuf_getline(&buf, fp) != EOF) {
 525                 if (*buf.buf == '#')
 526                         continue;
 527
 528                 strvec_split(&args, buf.buf);
 529                 if (args.nr && create_graft(args.nr, args.v, force, 1))
 530                         strbuf_addf(&err, "\n\t%s", buf.buf);
 531                 strvec_clear(&args);
 532         }
 533         fclose(fp);
 534
 535         strbuf_release(&buf);
 536
 537         if (!err.len)
 538                 return unlink_or_warn(graft_file);
 539
 540         warning(_("could not convert the following graft(s):\n%s"), err.buf);
 541         strbuf_release(&err);
 542
 543         return -1;
 544 }
 545
 546 int cmd_replace(int argc,
 547                 const char **argv,
 548                 const char *prefix,
 549                 struct repository *repo UNUSED)
 550 {
 551         int force = 0;
 552         int raw = 0;
 553         const char *format = NULL;
 554         enum {
 555                 MODE_UNSPECIFIED = 0,
 556                 MODE_LIST,
 557                 MODE_DELETE,
 558                 MODE_EDIT,
 559                 MODE_GRAFT,
 560                 MODE_CONVERT_GRAFT_FILE,
 561                 MODE_REPLACE
 562         } cmdmode = MODE_UNSPECIFIED;
 563         struct option options[] = {
 564                 OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
 565                 OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
 566                 OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
 567                 OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
 568                 OPT_CMDMODE(0, "convert-graft-file", &cmdmode, N_("convert existing graft file"), MODE_CONVERT_GRAFT_FILE),
 569                 OPT_BOOL_F('f', "force", &force, N_("replace the ref if it exists"),
 570                            PARSE_OPT_NOCOMPLETE),
 571                 OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
 572                 OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
 573                 OPT_END()
 574         };
 575
 576         disable_replace_refs();
 577         git_config(git_default_config, NULL);
 578
 579         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 580
 581         if (!cmdmode)
 582                 cmdmode = argc ? MODE_REPLACE : MODE_LIST;
 583
 584         if (format && cmdmode != MODE_LIST)
 585                 usage_msg_opt(_("--format cannot be used when not listing"),
 586                               git_replace_usage, options);
 587
 588         if (force &&
 589             cmdmode != MODE_REPLACE &&
 590             cmdmode != MODE_EDIT &&
 591             cmdmode != MODE_GRAFT &&
 592             cmdmode != MODE_CONVERT_GRAFT_FILE)
 593                 usage_msg_opt(_("-f only makes sense when writing a replacement"),
 594                               git_replace_usage, options);
 595
 596         if (raw && cmdmode != MODE_EDIT)
 597                 usage_msg_opt(_("--raw only makes sense with --edit"),
 598                               git_replace_usage, options);
 599
 600         switch (cmdmode) {
 601         case MODE_DELETE:
 602                 if (argc < 1)
 603                         usage_msg_opt(_("-d needs at least one argument"),
 604                                       git_replace_usage, options);
 605                 return for_each_replace_name(argv, delete_replace_ref);
 606
 607         case MODE_REPLACE:
 608                 if (argc != 2)
 609                         usage_msg_opt(_("bad number of arguments"),
 610                                       git_replace_usage, options);
 611                 return replace_object(argv[0], argv[1], force);
 612
 613         case MODE_EDIT:
 614                 if (argc != 1)
 615                         usage_msg_opt(_("-e needs exactly one argument"),
 616                                       git_replace_usage, options);
 617                 return edit_and_replace(argv[0], force, raw);
 618
 619         case MODE_GRAFT:
 620                 if (argc < 1)
 621                         usage_msg_opt(_("-g needs at least one argument"),
 622                                       git_replace_usage, options);
 623                 return create_graft(argc, argv, force, 0);
 624
 625         case MODE_CONVERT_GRAFT_FILE:
 626                 if (argc != 0)
 627                         usage_msg_opt(_("--convert-graft-file takes no argument"),
 628                                       git_replace_usage, options);
 629                 return !!convert_graft_file(force);
 630
 631         case MODE_LIST:
 632                 if (argc > 1)
 633                         usage_msg_opt(_("only one pattern can be given with -l"),
 634                                       git_replace_usage, options);
 635                 return list_replace_refs(argv[0], format);
 636
 637         default:
 638                 BUG("invalid cmdmode %d", (int)cmdmode);
 639         }
 640 }