| 1 | #define USE_THE_REPOSITORY_VARIABLE |
| 2 | |
| 3 | #include "git-compat-util.h" |
| 4 | #include "environment.h" |
| 5 | #include "hex.h" |
| 6 | #include "merge-ort.h" |
| 7 | #include "object-name.h" |
| 8 | #include "refs.h" |
| 9 | #include "replay.h" |
| 10 | #include "revision.h" |
| 11 | #include "sequencer.h" |
| 12 | #include "strmap.h" |
| 13 | #include "tree.h" |
| 14 | |
| 15 | /* |
| 16 | * We technically need USE_THE_REPOSITORY_VARIABLE for DEFAULT_ABBREV, but |
| 17 | * do not want to use the_repository. |
| 18 | */ |
| 19 | #define the_repository DO_NOT_USE_THE_REPOSITORY |
| 20 | |
| 21 | enum replay_mode { |
| 22 | REPLAY_MODE_PICK, |
| 23 | REPLAY_MODE_REVERT, |
| 24 | }; |
| 25 | |
| 26 | static const char *short_commit_name(struct repository *repo, |
| 27 | struct commit *commit) |
| 28 | { |
| 29 | return repo_find_unique_abbrev(repo, &commit->object.oid, |
| 30 | DEFAULT_ABBREV); |
| 31 | } |
| 32 | |
| 33 | static struct commit *peel_committish(struct repository *repo, |
| 34 | const char *name, |
| 35 | const char *mode) |
| 36 | { |
| 37 | struct object *obj; |
| 38 | struct object_id oid; |
| 39 | struct commit *commit; |
| 40 | |
| 41 | if (repo_get_oid(repo, name, &oid)) |
| 42 | die(_("'%s' is not a valid commit-ish for %s"), name, mode); |
| 43 | obj = parse_object_or_die(repo, &oid, name); |
| 44 | commit = (struct commit *)repo_peel_to_type(repo, name, 0, obj, |
| 45 | OBJ_COMMIT); |
| 46 | if (!commit) |
| 47 | die(_("'%s' does not point to a commit for %s"), name, mode); |
| 48 | return commit; |
| 49 | } |
| 50 | |
| 51 | static char *get_author(const char *message) |
| 52 | { |
| 53 | size_t len; |
| 54 | const char *a; |
| 55 | |
| 56 | a = find_commit_header(message, "author", &len); |
| 57 | if (a) |
| 58 | return xmemdupz(a, len); |
| 59 | |
| 60 | return NULL; |
| 61 | } |
| 62 | |
| 63 | static void generate_revert_message(struct strbuf *msg, |
| 64 | struct commit *commit, |
| 65 | struct repository *repo) |
| 66 | { |
| 67 | const char *out_enc = get_commit_output_encoding(); |
| 68 | const char *message = repo_logmsg_reencode(repo, commit, NULL, out_enc); |
| 69 | const char *subject_start; |
| 70 | int subject_len; |
| 71 | char *subject; |
| 72 | |
| 73 | subject_len = find_commit_subject(message, &subject_start); |
| 74 | subject = xmemdupz(subject_start, subject_len); |
| 75 | |
| 76 | sequencer_format_revert_message(repo, subject, commit, |
| 77 | commit->parents ? commit->parents->item : NULL, |
| 78 | false, msg); |
| 79 | |
| 80 | free(subject); |
| 81 | repo_unuse_commit_buffer(repo, commit, message); |
| 82 | } |
| 83 | |
| 84 | static struct commit *create_commit(struct repository *repo, |
| 85 | struct tree *tree, |
| 86 | struct commit *based_on, |
| 87 | struct commit *parent, |
| 88 | enum replay_mode mode) |
| 89 | { |
| 90 | struct object_id ret; |
| 91 | struct object *obj = NULL; |
| 92 | struct commit_list *parents = NULL; |
| 93 | char *author = NULL; |
| 94 | char *sign_commit = NULL; /* FIXME: cli users might want to sign again */ |
| 95 | struct commit_extra_header *extra = NULL; |
| 96 | struct strbuf msg = STRBUF_INIT; |
| 97 | const char *out_enc = get_commit_output_encoding(); |
| 98 | const char *message = repo_logmsg_reencode(repo, based_on, |
| 99 | NULL, out_enc); |
| 100 | const char *orig_message = NULL; |
| 101 | const char *exclude_gpgsig[] = { "gpgsig", "gpgsig-sha256", NULL }; |
| 102 | |
| 103 | commit_list_insert(parent, &parents); |
| 104 | extra = read_commit_extra_headers(based_on, exclude_gpgsig); |
| 105 | if (mode == REPLAY_MODE_REVERT) { |
| 106 | generate_revert_message(&msg, based_on, repo); |
| 107 | /* For revert, use current user as author (NULL = use default) */ |
| 108 | } else if (mode == REPLAY_MODE_PICK) { |
| 109 | find_commit_subject(message, &orig_message); |
| 110 | strbuf_addstr(&msg, orig_message); |
| 111 | author = get_author(message); |
| 112 | } else { |
| 113 | BUG("unexpected replay mode %d", mode); |
| 114 | } |
| 115 | reset_ident_date(); |
| 116 | if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents, |
| 117 | &ret, author, NULL, sign_commit, extra)) { |
| 118 | error(_("failed to write commit object")); |
| 119 | goto out; |
| 120 | } |
| 121 | |
| 122 | obj = parse_object(repo, &ret); |
| 123 | |
| 124 | out: |
| 125 | repo_unuse_commit_buffer(repo, based_on, message); |
| 126 | free_commit_extra_headers(extra); |
| 127 | commit_list_free(parents); |
| 128 | strbuf_release(&msg); |
| 129 | free(author); |
| 130 | return (struct commit *)obj; |
| 131 | } |
| 132 | |
| 133 | struct ref_info { |
| 134 | struct commit *onto; |
| 135 | struct strset positive_refs; |
| 136 | struct strset negative_refs; |
| 137 | size_t positive_refexprs; |
| 138 | size_t negative_refexprs; |
| 139 | }; |
| 140 | |
| 141 | static void get_ref_information(struct repository *repo, |
| 142 | struct rev_cmdline_info *cmd_info, |
| 143 | struct ref_info *ref_info) |
| 144 | { |
| 145 | ref_info->onto = NULL; |
| 146 | strset_init(&ref_info->positive_refs); |
| 147 | strset_init(&ref_info->negative_refs); |
| 148 | ref_info->positive_refexprs = 0; |
| 149 | ref_info->negative_refexprs = 0; |
| 150 | |
| 151 | /* |
| 152 | * When the user specifies e.g. |
| 153 | * git replay origin/main..mybranch |
| 154 | * git replay ^origin/next mybranch1 mybranch2 |
| 155 | * we want to be able to determine where to replay the commits. In |
| 156 | * these examples, the branches are probably based on an old version |
| 157 | * of either origin/main or origin/next, so we want to replay on the |
| 158 | * newest version of that branch. In contrast we would want to error |
| 159 | * out if they ran |
| 160 | * git replay ^origin/master ^origin/next mybranch |
| 161 | * git replay mybranch~2..mybranch |
| 162 | * the first of those because there's no unique base to choose, and |
| 163 | * the second because they'd likely just be replaying commits on top |
| 164 | * of the same commit and not making any difference. |
| 165 | */ |
| 166 | for (size_t i = 0; i < cmd_info->nr; i++) { |
| 167 | struct rev_cmdline_entry *e = cmd_info->rev + i; |
| 168 | struct object_id oid; |
| 169 | const char *refexpr = e->name; |
| 170 | char *fullname = NULL; |
| 171 | int can_uniquely_dwim = 1; |
| 172 | |
| 173 | if (*refexpr == '^') |
| 174 | refexpr++; |
| 175 | if (repo_dwim_ref(repo, refexpr, strlen(refexpr), &oid, &fullname, 0) != 1) |
| 176 | can_uniquely_dwim = 0; |
| 177 | |
| 178 | if (e->flags & BOTTOM) { |
| 179 | if (can_uniquely_dwim) |
| 180 | strset_add(&ref_info->negative_refs, fullname); |
| 181 | if (!ref_info->negative_refexprs) |
| 182 | ref_info->onto = lookup_commit_reference_gently(repo, |
| 183 | &e->item->oid, 1); |
| 184 | ref_info->negative_refexprs++; |
| 185 | } else { |
| 186 | if (can_uniquely_dwim) |
| 187 | strset_add(&ref_info->positive_refs, fullname); |
| 188 | ref_info->positive_refexprs++; |
| 189 | } |
| 190 | |
| 191 | free(fullname); |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | static void set_up_branch_mode(struct repository *repo, |
| 196 | char **branch_name, |
| 197 | const char *option_name, |
| 198 | struct ref_info *rinfo, |
| 199 | struct commit **onto) |
| 200 | { |
| 201 | struct object_id oid; |
| 202 | char *fullname = NULL; |
| 203 | |
| 204 | if (repo_dwim_ref(repo, *branch_name, strlen(*branch_name), |
| 205 | &oid, &fullname, 0) == 1) { |
| 206 | free(*branch_name); |
| 207 | *branch_name = fullname; |
| 208 | } else { |
| 209 | die(_("argument to %s must be a reference"), option_name); |
| 210 | } |
| 211 | *onto = peel_committish(repo, *branch_name, option_name); |
| 212 | if (rinfo->positive_refexprs > 1) |
| 213 | die(_("'%s' cannot be used with multiple revision ranges " |
| 214 | "because the ordering would be ill-defined"), |
| 215 | option_name); |
| 216 | } |
| 217 | |
| 218 | static void set_up_replay_mode(struct repository *repo, |
| 219 | struct rev_cmdline_info *cmd_info, |
| 220 | const char *onto_name, |
| 221 | bool *detached_head, |
| 222 | char **advance_name, |
| 223 | char **revert_name, |
| 224 | struct commit **onto, |
| 225 | struct strset **update_refs) |
| 226 | { |
| 227 | struct ref_info rinfo; |
| 228 | int head_flags = 0; |
| 229 | |
| 230 | refs_read_ref_full(get_main_ref_store(repo), "HEAD", |
| 231 | RESOLVE_REF_NO_RECURSE, NULL, &head_flags); |
| 232 | *detached_head = !(head_flags & REF_ISSYMREF); |
| 233 | |
| 234 | get_ref_information(repo, cmd_info, &rinfo); |
| 235 | if (!rinfo.positive_refexprs) |
| 236 | die(_("need some commits to replay")); |
| 237 | |
| 238 | if (onto_name) { |
| 239 | *onto = peel_committish(repo, onto_name, "--onto"); |
| 240 | if (rinfo.positive_refexprs < |
| 241 | strset_get_size(&rinfo.positive_refs)) |
| 242 | die(_("all positive revisions given must be references")); |
| 243 | *update_refs = xcalloc(1, sizeof(**update_refs)); |
| 244 | **update_refs = rinfo.positive_refs; |
| 245 | memset(&rinfo.positive_refs, 0, sizeof(**update_refs)); |
| 246 | } else if (*advance_name) { |
| 247 | set_up_branch_mode(repo, advance_name, "--advance", &rinfo, onto); |
| 248 | } else if (*revert_name) { |
| 249 | set_up_branch_mode(repo, revert_name, "--revert", &rinfo, onto); |
| 250 | } else { |
| 251 | BUG("expected one of onto_name, *advance_name, or *revert_name"); |
| 252 | } |
| 253 | strset_clear(&rinfo.negative_refs); |
| 254 | strset_clear(&rinfo.positive_refs); |
| 255 | } |
| 256 | |
| 257 | static struct commit *get_mapped_commit(kh_oid_map_t *replayed_commits, |
| 258 | struct commit *commit, |
| 259 | struct commit *fallback) |
| 260 | { |
| 261 | khint_t pos; |
| 262 | if (!commit) |
| 263 | return fallback; |
| 264 | pos = kh_get_oid_map(replayed_commits, commit->object.oid); |
| 265 | if (pos == kh_end(replayed_commits)) |
| 266 | return fallback; |
| 267 | return kh_value(replayed_commits, pos); |
| 268 | } |
| 269 | |
| 270 | static void put_mapped_commit(kh_oid_map_t *replayed_commits, |
| 271 | struct commit *commit, |
| 272 | struct commit *new_commit) |
| 273 | { |
| 274 | khint_t pos; |
| 275 | int ret; |
| 276 | |
| 277 | pos = kh_put_oid_map(replayed_commits, commit->object.oid, &ret); |
| 278 | if (ret == 0) |
| 279 | BUG("Duplicate rewritten commit: %s", |
| 280 | oid_to_hex(&commit->object.oid)); |
| 281 | |
| 282 | kh_value(replayed_commits, pos) = new_commit; |
| 283 | } |
| 284 | |
| 285 | static struct commit *pick_regular_commit(struct repository *repo, |
| 286 | struct commit *pickme, |
| 287 | struct commit *replayed_base, |
| 288 | struct merge_options *merge_opt, |
| 289 | struct merge_result *result, |
| 290 | enum replay_mode mode, |
| 291 | enum replay_empty_commit_action empty) |
| 292 | { |
| 293 | struct tree *pickme_tree, *base_tree, *replayed_base_tree; |
| 294 | |
| 295 | if (pickme->parents) |
| 296 | base_tree = repo_get_commit_tree(repo, pickme->parents->item); |
| 297 | else |
| 298 | base_tree = lookup_tree(repo, repo->hash_algo->empty_tree); |
| 299 | |
| 300 | replayed_base_tree = repo_get_commit_tree(repo, replayed_base); |
| 301 | pickme_tree = repo_get_commit_tree(repo, pickme); |
| 302 | |
| 303 | if (mode == REPLAY_MODE_PICK) { |
| 304 | /* Cherry-pick: normal order */ |
| 305 | merge_opt->branch1 = short_commit_name(repo, replayed_base); |
| 306 | merge_opt->branch2 = short_commit_name(repo, pickme); |
| 307 | if (pickme->parents) |
| 308 | merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2); |
| 309 | else |
| 310 | merge_opt->ancestor = xstrdup("empty tree"); |
| 311 | |
| 312 | merge_incore_nonrecursive(merge_opt, |
| 313 | base_tree, |
| 314 | replayed_base_tree, |
| 315 | pickme_tree, |
| 316 | result); |
| 317 | |
| 318 | free((char *)merge_opt->ancestor); |
| 319 | } else if (mode == REPLAY_MODE_REVERT) { |
| 320 | /* Revert: swap base and pickme to reverse the diff */ |
| 321 | const char *pickme_name = short_commit_name(repo, pickme); |
| 322 | merge_opt->branch1 = short_commit_name(repo, replayed_base); |
| 323 | merge_opt->branch2 = xstrfmt("parent of %s", pickme_name); |
| 324 | merge_opt->ancestor = pickme_name; |
| 325 | |
| 326 | merge_incore_nonrecursive(merge_opt, |
| 327 | pickme_tree, |
| 328 | replayed_base_tree, |
| 329 | base_tree, |
| 330 | result); |
| 331 | |
| 332 | free((char *)merge_opt->branch2); |
| 333 | } else { |
| 334 | BUG("unexpected replay mode %d", mode); |
| 335 | } |
| 336 | merge_opt->ancestor = NULL; |
| 337 | merge_opt->branch2 = NULL; |
| 338 | |
| 339 | if (!result->clean) |
| 340 | return NULL; |
| 341 | |
| 342 | /* Handle commits that become empty */ |
| 343 | if (oideq(&replayed_base_tree->object.oid, &result->tree->object.oid) && |
| 344 | !oideq(&pickme_tree->object.oid, &base_tree->object.oid)) { |
| 345 | switch (empty) { |
| 346 | case REPLAY_EMPTY_COMMIT_DROP: |
| 347 | return replayed_base; |
| 348 | case REPLAY_EMPTY_COMMIT_KEEP: |
| 349 | break; |
| 350 | case REPLAY_EMPTY_COMMIT_ABORT: |
| 351 | result->clean = error(_("commit %s became empty after replay"), |
| 352 | oid_to_hex(&pickme->object.oid)); |
| 353 | return NULL; |
| 354 | } |
| 355 | } |
| 356 | |
| 357 | return create_commit(repo, result->tree, pickme, replayed_base, mode); |
| 358 | } |
| 359 | |
| 360 | void replay_result_release(struct replay_result *result) |
| 361 | { |
| 362 | for (size_t i = 0; i < result->updates_nr; i++) |
| 363 | free(result->updates[i].refname); |
| 364 | free(result->updates); |
| 365 | } |
| 366 | |
| 367 | void replay_result_queue_update(struct replay_result *result, |
| 368 | const char *refname, |
| 369 | const struct object_id *old_oid, |
| 370 | const struct object_id *new_oid) |
| 371 | { |
| 372 | ALLOC_GROW(result->updates, result->updates_nr + 1, result->updates_alloc); |
| 373 | result->updates[result->updates_nr].refname = xstrdup(refname); |
| 374 | result->updates[result->updates_nr].old_oid = *old_oid; |
| 375 | result->updates[result->updates_nr].new_oid = *new_oid; |
| 376 | result->updates_nr++; |
| 377 | } |
| 378 | |
| 379 | int replay_revisions(struct rev_info *revs, |
| 380 | struct replay_revisions_options *opts, |
| 381 | struct replay_result *out) |
| 382 | { |
| 383 | kh_oid_map_t *replayed_commits = NULL; |
| 384 | struct strset *update_refs = NULL; |
| 385 | struct commit *last_commit = NULL; |
| 386 | struct commit *commit; |
| 387 | struct commit *onto = NULL; |
| 388 | struct merge_options merge_opt = { 0 }; |
| 389 | struct merge_result result = { |
| 390 | .clean = 1, |
| 391 | }; |
| 392 | bool detached_head; |
| 393 | char *advance; |
| 394 | char *revert; |
| 395 | const char *ref; |
| 396 | struct object_id old_oid; |
| 397 | enum replay_mode mode = REPLAY_MODE_PICK; |
| 398 | int ret; |
| 399 | |
| 400 | advance = xstrdup_or_null(opts->advance); |
| 401 | revert = xstrdup_or_null(opts->revert); |
| 402 | if (revert) |
| 403 | mode = REPLAY_MODE_REVERT; |
| 404 | set_up_replay_mode(revs->repo, &revs->cmdline, opts->onto, |
| 405 | &detached_head, &advance, &revert, &onto, &update_refs); |
| 406 | |
| 407 | if (opts->ref) { |
| 408 | struct object_id oid; |
| 409 | |
| 410 | if (update_refs && strset_get_size(update_refs) > 1) { |
| 411 | ret = error(_("'--ref' cannot be used with multiple revision ranges")); |
| 412 | goto out; |
| 413 | } |
| 414 | if (check_refname_format(opts->ref, 0) || !starts_with(opts->ref, "refs/")) { |
| 415 | ret = error(_("'%s' is not a valid refname"), opts->ref); |
| 416 | goto out; |
| 417 | } |
| 418 | ref = opts->ref; |
| 419 | if (!refs_read_ref(get_main_ref_store(revs->repo), opts->ref, &oid)) |
| 420 | oidcpy(&old_oid, &oid); |
| 421 | else |
| 422 | oidclr(&old_oid, revs->repo->hash_algo); |
| 423 | } else { |
| 424 | ref = advance ? advance : revert; |
| 425 | oidcpy(&old_oid, &onto->object.oid); |
| 426 | } |
| 427 | |
| 428 | if (prepare_revision_walk(revs) < 0) { |
| 429 | ret = error(_("error preparing revisions")); |
| 430 | goto out; |
| 431 | } |
| 432 | |
| 433 | init_basic_merge_options(&merge_opt, revs->repo); |
| 434 | merge_opt.show_rename_progress = 0; |
| 435 | last_commit = onto; |
| 436 | replayed_commits = kh_init_oid_map(); |
| 437 | while ((commit = get_revision(revs))) { |
| 438 | const struct name_decoration *decoration; |
| 439 | |
| 440 | if (commit->parents && commit->parents->next) { |
| 441 | if (!opts->linearize) |
| 442 | die(_("replaying merge commits is not supported yet!")); |
| 443 | /* |
| 444 | * Drop the merge commit: do not pick it, leave |
| 445 | * `last_commit` unchanged, and fall through to the |
| 446 | * rest of the loop. As a result: |
| 447 | * - refs pointing to the merge commit will be updated |
| 448 | * to `last_commit`. |
| 449 | * - the next replayed commit uses `last_commit` as its |
| 450 | * `base`. |
| 451 | */ |
| 452 | } else { |
| 453 | /* |
| 454 | * Decide where to replay this commit onto. |
| 455 | * If the parent commit was replayed already, the replayed result |
| 456 | * can be found in `replayed_commits`. Otherwise fall back to `onto`. |
| 457 | * When reverting, commits are replayed in reverse order and thus |
| 458 | * its parent isn't replayed yet. Therefore revert commits are |
| 459 | * always replayed onto `last_commit`. |
| 460 | * Also when opts->linearize is true, set the base to |
| 461 | * `last_commit` to create a single linear history. |
| 462 | */ |
| 463 | struct commit *parent = commit->parents ? commit->parents->item : NULL; |
| 464 | struct commit *base = get_mapped_commit(replayed_commits, parent, onto); |
| 465 | |
| 466 | if (opts->linearize || mode == REPLAY_MODE_REVERT) |
| 467 | base = last_commit; |
| 468 | |
| 469 | last_commit = pick_regular_commit(revs->repo, commit, base, |
| 470 | &merge_opt, &result, |
| 471 | mode, opts->empty); |
| 472 | } |
| 473 | |
| 474 | if (!last_commit) |
| 475 | break; |
| 476 | |
| 477 | /* Record commit -> last_commit mapping */ |
| 478 | put_mapped_commit(replayed_commits, commit, last_commit); |
| 479 | |
| 480 | /* Update any necessary branches */ |
| 481 | if (ref) |
| 482 | continue; |
| 483 | |
| 484 | for (decoration = get_name_decoration(&commit->object); |
| 485 | decoration; |
| 486 | decoration = decoration->next) |
| 487 | { |
| 488 | if (decoration->type != DECORATION_REF_LOCAL && |
| 489 | decoration->type != DECORATION_REF_HEAD) |
| 490 | continue; |
| 491 | |
| 492 | /* |
| 493 | * We only need to update HEAD separately in case it's |
| 494 | * detached. If it's not we'd already update the branch |
| 495 | * it is pointing to. |
| 496 | */ |
| 497 | if (decoration->type == DECORATION_REF_HEAD && !detached_head) |
| 498 | continue; |
| 499 | |
| 500 | if (!opts->contained && |
| 501 | !strset_contains(update_refs, decoration->name)) |
| 502 | continue; |
| 503 | |
| 504 | replay_result_queue_update(out, decoration->name, |
| 505 | &commit->object.oid, |
| 506 | &last_commit->object.oid); |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | if (result.clean < 0) { |
| 511 | ret = -1; |
| 512 | goto out; |
| 513 | } |
| 514 | |
| 515 | if (!result.clean) { |
| 516 | ret = 1; |
| 517 | goto out; |
| 518 | } |
| 519 | |
| 520 | if (ref) |
| 521 | replay_result_queue_update(out, ref, &old_oid, |
| 522 | &last_commit->object.oid); |
| 523 | |
| 524 | ret = 0; |
| 525 | |
| 526 | out: |
| 527 | if (update_refs) { |
| 528 | strset_clear(update_refs); |
| 529 | free(update_refs); |
| 530 | } |
| 531 | kh_destroy_oid_map(replayed_commits); |
| 532 | merge_finalize(&merge_opt, &result); |
| 533 | free(advance); |
| 534 | free(revert); |
| 535 | return ret; |
| 536 | } |