diff options
Diffstat (limited to 'builtin/history.c')
| -rw-r--r-- | builtin/history.c | 754 |
1 files changed, 754 insertions, 0 deletions
diff --git a/builtin/history.c b/builtin/history.c new file mode 100644 index 0000000000..9526938085 --- /dev/null +++ b/builtin/history.c @@ -0,0 +1,754 @@ +#define USE_THE_REPOSITORY_VARIABLE + +#include "builtin.h" +#include "cache-tree.h" +#include "commit.h" +#include "commit-reach.h" +#include "config.h" +#include "editor.h" +#include "environment.h" +#include "gettext.h" +#include "hex.h" +#include "lockfile.h" +#include "oidmap.h" +#include "parse-options.h" +#include "path.h" +#include "read-cache.h" +#include "refs.h" +#include "replay.h" +#include "revision.h" +#include "sequencer.h" +#include "strvec.h" +#include "tree.h" +#include "unpack-trees.h" +#include "wt-status.h" + +#define GIT_HISTORY_REWORD_USAGE \ + N_("git history reword <commit> [--dry-run] [--update-refs=(branches|head)]") +#define GIT_HISTORY_SPLIT_USAGE \ + N_("git history split <commit> [--dry-run] [--update-refs=(branches|head)] [--] [<pathspec>...]") + +static void change_data_free(void *util, const char *str UNUSED) +{ + struct wt_status_change_data *d = util; + free(d->rename_source); + free(d); +} + +static int fill_commit_message(struct repository *repo, + const struct object_id *old_tree, + const struct object_id *new_tree, + const char *default_message, + const char *action, + struct strbuf *out) +{ + const char *path = git_path_commit_editmsg(); + const char *hint = + _("Please enter the commit message for the %s changes." + " Lines starting\nwith '%s' will be ignored, and an" + " empty message aborts the commit.\n"); + struct wt_status s; + + strbuf_addstr(out, default_message); + strbuf_addch(out, '\n'); + strbuf_commented_addf(out, comment_line_str, hint, action, comment_line_str); + write_file_buf(path, out->buf, out->len); + + wt_status_prepare(repo, &s); + FREE_AND_NULL(s.branch); + s.ahead_behind_flags = AHEAD_BEHIND_QUICK; + s.commit_template = 1; + s.colopts = 0; + s.display_comment_prefix = 1; + s.hints = 0; + s.use_color = 0; + s.whence = FROM_COMMIT; + s.committable = 1; + + s.fp = fopen(git_path_commit_editmsg(), "a"); + if (!s.fp) + return error_errno(_("could not open '%s'"), git_path_commit_editmsg()); + + wt_status_collect_changes_trees(&s, old_tree, new_tree); + wt_status_print(&s); + wt_status_collect_free_buffers(&s); + string_list_clear_func(&s.change, change_data_free); + + strbuf_reset(out); + if (launch_editor(path, out, NULL)) { + fprintf(stderr, _("Aborting commit as launching the editor failed.\n")); + return -1; + } + strbuf_stripspace(out, comment_line_str); + + cleanup_message(out, COMMIT_MSG_CLEANUP_ALL, 0); + + if (!out->len) { + fprintf(stderr, _("Aborting commit due to empty commit message.\n")); + return -1; + } + + return 0; +} + +static int commit_tree_with_edited_message_ext(struct repository *repo, + const char *action, + struct commit *commit_with_message, + const struct commit_list *parents, + const struct object_id *old_tree, + const struct object_id *new_tree, + struct commit **out) +{ + const char *exclude_gpgsig[] = { + /* We reencode the message, so the encoding needs to be stripped. */ + "encoding", + /* We need to strip signatures as those will become invalid. */ + "gpgsig", + "gpgsig-sha256", + NULL, + }; + const char *original_message, *original_body, *ptr; + struct commit_extra_header *original_extra_headers = NULL; + struct strbuf commit_message = STRBUF_INIT; + struct object_id rewritten_commit_oid; + char *original_author = NULL; + size_t len; + int ret; + + /* We retain authorship of the original commit. */ + original_message = repo_logmsg_reencode(repo, commit_with_message, NULL, NULL); + ptr = find_commit_header(original_message, "author", &len); + if (ptr) + original_author = xmemdupz(ptr, len); + find_commit_subject(original_message, &original_body); + + ret = fill_commit_message(repo, old_tree, new_tree, + original_body, action, &commit_message); + if (ret < 0) + goto out; + + original_extra_headers = read_commit_extra_headers(commit_with_message, + exclude_gpgsig); + + ret = commit_tree_extended(commit_message.buf, commit_message.len, new_tree, + parents, &rewritten_commit_oid, original_author, + NULL, NULL, original_extra_headers); + if (ret < 0) + goto out; + + *out = lookup_commit_or_die(&rewritten_commit_oid, "rewritten commit"); + +out: + free_commit_extra_headers(original_extra_headers); + strbuf_release(&commit_message); + free(original_author); + return ret; +} + +static int commit_tree_with_edited_message(struct repository *repo, + const char *action, + struct commit *original, + struct commit **out) +{ + struct object_id parent_tree_oid; + const struct object_id *tree_oid; + struct commit *parent; + + tree_oid = &repo_get_commit_tree(repo, original)->object.oid; + + parent = original->parents ? original->parents->item : NULL; + if (parent) { + if (repo_parse_commit(repo, parent)) { + return error(_("unable to parse parent commit %s"), + oid_to_hex(&parent->object.oid)); + } + + parent_tree_oid = repo_get_commit_tree(repo, parent)->object.oid; + } else { + oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree); + } + + return commit_tree_with_edited_message_ext(repo, action, original, original->parents, + &parent_tree_oid, tree_oid, out); +} + +enum ref_action { + REF_ACTION_DEFAULT, + REF_ACTION_BRANCHES, + REF_ACTION_HEAD, +}; + +static int parse_ref_action(const struct option *opt, const char *value, int unset) +{ + enum ref_action *action = opt->value; + + BUG_ON_OPT_NEG_NOARG(unset, value); + if (!strcmp(value, "branches")) { + *action = REF_ACTION_BRANCHES; + } else if (!strcmp(value, "head")) { + *action = REF_ACTION_HEAD; + } else { + return error(_("%s expects one of 'branches' or 'head'"), + opt->long_name); + } + + return 0; +} + +static int revwalk_contains_merges(struct repository *repo, + const struct strvec *revwalk_args) +{ + struct strvec args = STRVEC_INIT; + struct rev_info revs; + int ret; + + strvec_pushv(&args, revwalk_args->v); + strvec_push(&args, "--min-parents=2"); + + repo_init_revisions(repo, &revs, NULL); + + setup_revisions_from_strvec(&args, &revs, NULL); + if (args.nr != 1) + BUG("revisions were set up with invalid argument"); + + if (prepare_revision_walk(&revs) < 0) { + ret = error(_("error preparing revisions")); + goto out; + } + + if (get_revision(&revs)) { + ret = error(_("replaying merge commits is not supported yet!")); + goto out; + } + + reset_revision_walk(); + ret = 0; + +out: + release_revisions(&revs); + strvec_clear(&args); + return ret; +} + +static int setup_revwalk(struct repository *repo, + enum ref_action action, + struct commit *original, + struct rev_info *revs) +{ + struct strvec args = STRVEC_INIT; + int ret; + + repo_init_revisions(repo, revs, NULL); + strvec_push(&args, "ignored"); + strvec_push(&args, "--reverse"); + strvec_push(&args, "--topo-order"); + strvec_push(&args, "--full-history"); + + /* We only want to see commits that are descendants of the old commit. */ + strvec_pushf(&args, "--ancestry-path=%s", + oid_to_hex(&original->object.oid)); + + /* + * Ancestry path may also show ancestors of the old commit, but we + * don't want to see those, either. + */ + strvec_pushf(&args, "^%s", oid_to_hex(&original->object.oid)); + + /* + * When we're asked to update HEAD we need to verify that the commit + * that we want to rewrite is actually an ancestor of it and, if so, + * update it. Otherwise we'll update (or print) all descendant + * branches. + */ + if (action == REF_ACTION_HEAD) { + struct commit_list *from_list = NULL; + struct commit *head; + + head = lookup_commit_reference_by_name("HEAD"); + if (!head) { + ret = error(_("cannot look up HEAD")); + goto out; + } + + commit_list_insert(original, &from_list); + ret = repo_is_descendant_of(repo, head, from_list); + free_commit_list(from_list); + + if (ret < 0) { + ret = error(_("cannot determine descendance")); + goto out; + } else if (!ret) { + ret = error(_("rewritten commit must be an ancestor " + "of HEAD when using --update-refs=head")); + goto out; + } + + strvec_push(&args, "HEAD"); + } else { + strvec_push(&args, "--branches"); + strvec_push(&args, "HEAD"); + } + + ret = revwalk_contains_merges(repo, &args); + if (ret < 0) + goto out; + + setup_revisions_from_strvec(&args, revs, NULL); + if (args.nr != 1) + BUG("revisions were set up with invalid argument"); + + ret = 0; + +out: + strvec_clear(&args); + return ret; +} + +static int handle_ref_update(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const struct object_id *old_oid, + const char *reflog_msg, + struct strbuf *err) +{ + if (!transaction) { + printf("update %s %s %s\n", + refname, oid_to_hex(new_oid), oid_to_hex(old_oid)); + return 0; + } + + return ref_transaction_update(transaction, refname, new_oid, old_oid, + NULL, NULL, 0, reflog_msg, err); +} + +static int handle_reference_updates(struct rev_info *revs, + enum ref_action action, + struct commit *original, + struct commit *rewritten, + const char *reflog_msg, + int dry_run) +{ + const struct name_decoration *decoration; + struct replay_revisions_options opts = { 0 }; + struct replay_result result = { 0 }; + struct ref_transaction *transaction = NULL; + struct strbuf err = STRBUF_INIT; + char hex[GIT_MAX_HEXSZ + 1]; + bool detached_head; + int head_flags = 0; + int ret; + + refs_read_ref_full(get_main_ref_store(revs->repo), "HEAD", + RESOLVE_REF_NO_RECURSE, NULL, &head_flags); + detached_head = !(head_flags & REF_ISSYMREF); + + opts.onto = oid_to_hex_r(hex, &rewritten->object.oid); + + ret = replay_revisions(revs, &opts, &result); + if (ret) + goto out; + + if (action != REF_ACTION_BRANCHES && action != REF_ACTION_HEAD) + BUG("unsupported ref action %d", action); + + if (!dry_run) { + transaction = ref_store_transaction_begin(get_main_ref_store(revs->repo), 0, &err); + if (!transaction) { + ret = error(_("failed to begin ref transaction: %s"), err.buf); + goto out; + } + } + + for (size_t i = 0; i < result.updates_nr; i++) { + ret = handle_ref_update(transaction, + result.updates[i].refname, + &result.updates[i].new_oid, + &result.updates[i].old_oid, + reflog_msg, &err); + if (ret) { + ret = error(_("failed to update ref '%s': %s"), + result.updates[i].refname, err.buf); + goto out; + } + } + + /* + * `replay_revisions()` only updates references that are + * ancestors of `rewritten`, so we need to manually + * handle updating references that point to `original`. + */ + for (decoration = get_name_decoration(&original->object); + decoration; + decoration = decoration->next) + { + if (decoration->type != DECORATION_REF_LOCAL && + decoration->type != DECORATION_REF_HEAD) + continue; + + if (action == REF_ACTION_HEAD && + decoration->type != DECORATION_REF_HEAD) + continue; + + /* + * We only need to update HEAD separately in case it's + * detached. If it's not we'd already update the branch + * it is pointing to. + */ + if (action == REF_ACTION_BRANCHES && + decoration->type == DECORATION_REF_HEAD && + !detached_head) + continue; + + ret = handle_ref_update(transaction, + decoration->name, + &rewritten->object.oid, + &original->object.oid, + reflog_msg, &err); + if (ret) { + ret = error(_("failed to update ref '%s': %s"), + decoration->name, err.buf); + goto out; + } + } + + if (transaction && ref_transaction_commit(transaction, &err)) { + ret = error(_("failed to commit ref transaction: %s"), err.buf); + goto out; + } + + ret = 0; + +out: + ref_transaction_free(transaction); + replay_result_release(&result); + strbuf_release(&err); + return ret; +} + +static int cmd_history_reword(int argc, + const char **argv, + const char *prefix, + struct repository *repo) +{ + const char * const usage[] = { + GIT_HISTORY_REWORD_USAGE, + NULL, + }; + enum ref_action action = REF_ACTION_DEFAULT; + int dry_run = 0; + struct option options[] = { + OPT_CALLBACK_F(0, "update-refs", &action, "(branches|head)", + N_("control which refs should be updated"), + PARSE_OPT_NONEG, parse_ref_action), + OPT_BOOL('n', "dry-run", &dry_run, + N_("perform a dry-run without updating any refs")), + OPT_END(), + }; + struct strbuf reflog_msg = STRBUF_INIT; + struct commit *original, *rewritten; + struct rev_info revs = { 0 }; + int ret; + + argc = parse_options(argc, argv, prefix, options, usage, 0); + if (argc != 1) { + ret = error(_("command expects a single revision")); + goto out; + } + repo_config(repo, git_default_config, NULL); + + if (action == REF_ACTION_DEFAULT) + action = REF_ACTION_BRANCHES; + + original = lookup_commit_reference_by_name(argv[0]); + if (!original) { + ret = error(_("commit cannot be found: %s"), argv[0]); + goto out; + } + + ret = setup_revwalk(repo, action, original, &revs); + if (ret) + goto out; + + ret = commit_tree_with_edited_message(repo, "reworded", original, &rewritten); + if (ret < 0) { + ret = error(_("failed writing reworded commit")); + goto out; + } + + strbuf_addf(&reflog_msg, "reword: updating %s", argv[0]); + + ret = handle_reference_updates(&revs, action, original, rewritten, + reflog_msg.buf, dry_run); + if (ret < 0) { + ret = error(_("failed replaying descendants")); + goto out; + } + + ret = 0; + +out: + strbuf_release(&reflog_msg); + release_revisions(&revs); + return ret; +} + +static int write_ondisk_index(struct repository *repo, + struct object_id *oid, + const char *path) +{ + struct unpack_trees_options opts = { 0 }; + struct lock_file lock = LOCK_INIT; + struct tree_desc tree_desc; + struct index_state index; + struct tree *tree; + int ret; + + index_state_init(&index, repo); + + opts.head_idx = -1; + opts.src_index = &index; + opts.dst_index = &index; + + tree = repo_parse_tree_indirect(repo, oid); + init_tree_desc(&tree_desc, &tree->object.oid, tree->buffer, tree->size); + + if (unpack_trees(1, &tree_desc, &opts)) { + ret = error(_("unable to populate index with tree")); + goto out; + } + + prime_cache_tree(repo, &index, tree); + + if (hold_lock_file_for_update(&lock, path, 0) < 0) { + ret = error_errno(_("unable to acquire index lock")); + goto out; + } + + if (write_locked_index(&index, &lock, COMMIT_LOCK)) { + ret = error(_("unable to write new index file")); + goto out; + } + + ret = 0; + +out: + rollback_lock_file(&lock); + release_index(&index); + return ret; +} + +static int split_commit(struct repository *repo, + struct commit *original, + struct pathspec *pathspec, + struct commit **out) +{ + struct interactive_options interactive_opts = INTERACTIVE_OPTIONS_INIT; + struct strbuf index_file = STRBUF_INIT; + struct index_state index = INDEX_STATE_INIT(repo); + const struct object_id *original_commit_tree_oid; + const struct object_id *old_tree_oid, *new_tree_oid; + struct object_id parent_tree_oid; + char original_commit_oid[GIT_MAX_HEXSZ + 1]; + struct commit *first_commit, *second_commit; + struct commit_list *parents = NULL; + struct tree *split_tree; + int ret; + + if (original->parents) { + if (repo_parse_commit(repo, original->parents->item)) { + ret = error(_("unable to parse parent commit %s"), + oid_to_hex(&original->parents->item->object.oid)); + goto out; + } + + parent_tree_oid = *get_commit_tree_oid(original->parents->item); + } else { + oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree); + } + original_commit_tree_oid = get_commit_tree_oid(original); + + /* + * Construct the first commit. This is done by taking the original + * commit parent's tree and selectively patching changes from the diff + * between that parent and its child. + */ + repo_git_path_replace(repo, &index_file, "%s", "history-split.index"); + + ret = write_ondisk_index(repo, &parent_tree_oid, index_file.buf); + if (ret < 0) + goto out; + + ret = read_index_from(&index, index_file.buf, repo->gitdir); + if (ret < 0) { + ret = error(_("failed reading temporary index")); + goto out; + } + + oid_to_hex_r(original_commit_oid, &original->object.oid); + ret = run_add_p_index(repo, &index, index_file.buf, &interactive_opts, + original_commit_oid, pathspec, ADD_P_DISALLOW_EDIT); + if (ret < 0) + goto out; + + split_tree = write_in_core_index_as_tree(repo, &index); + if (!split_tree) { + ret = error(_("failed split tree")); + goto out; + } + + unlink(index_file.buf); + strbuf_release(&index_file); + + /* + * We disallow the cases where either the split-out commit or the + * original commit would become empty. Consequently, if we see that the + * new tree ID matches either of those trees we abort. + */ + if (oideq(&split_tree->object.oid, &parent_tree_oid)) { + ret = error(_("split commit is empty")); + goto out; + } else if (oideq(&split_tree->object.oid, original_commit_tree_oid)) { + ret = error(_("split commit tree matches original commit")); + goto out; + } + + /* + * The first commit is constructed from the split-out tree. The base + * that shall be diffed against is the parent of the original commit. + */ + ret = commit_tree_with_edited_message_ext(repo, "split-out", original, + original->parents, &parent_tree_oid, + &split_tree->object.oid, &first_commit); + if (ret < 0) { + ret = error(_("failed writing first commit")); + goto out; + } + + /* + * The second commit is constructed from the original tree. The base to + * diff against and the parent in this case is the first split-out + * commit. + */ + commit_list_append(first_commit, &parents); + + old_tree_oid = &repo_get_commit_tree(repo, first_commit)->object.oid; + new_tree_oid = &repo_get_commit_tree(repo, original)->object.oid; + + ret = commit_tree_with_edited_message_ext(repo, "split-out", original, + parents, old_tree_oid, + new_tree_oid, &second_commit); + if (ret < 0) { + ret = error(_("failed writing second commit")); + goto out; + } + + *out = second_commit; + ret = 0; + +out: + if (index_file.len) + unlink(index_file.buf); + strbuf_release(&index_file); + free_commit_list(parents); + release_index(&index); + return ret; +} + +static int cmd_history_split(int argc, + const char **argv, + const char *prefix, + struct repository *repo) +{ + const char * const usage[] = { + GIT_HISTORY_SPLIT_USAGE, + NULL, + }; + enum ref_action action = REF_ACTION_DEFAULT; + int dry_run = 0; + struct option options[] = { + OPT_CALLBACK_F(0, "update-refs", &action, "(branches|head)", + N_("control ref update behavior"), + PARSE_OPT_NONEG, parse_ref_action), + OPT_BOOL('n', "dry-run", &dry_run, + N_("perform a dry-run without updating any refs")), + OPT_END(), + }; + struct commit *original, *rewritten = NULL; + struct strbuf reflog_msg = STRBUF_INIT; + struct pathspec pathspec = { 0 }; + struct rev_info revs = { 0 }; + int ret; + + argc = parse_options(argc, argv, prefix, options, usage, 0); + if (argc < 1) { + ret = error(_("command expects a committish")); + goto out; + } + repo_config(repo, git_default_config, NULL); + + if (action == REF_ACTION_DEFAULT) + action = REF_ACTION_BRANCHES; + + parse_pathspec(&pathspec, 0, + PATHSPEC_PREFER_FULL | + PATHSPEC_SYMLINK_LEADING_PATH | + PATHSPEC_PREFIX_ORIGIN, + prefix, argv + 1); + + original = lookup_commit_reference_by_name(argv[0]); + if (!original) { + ret = error(_("commit cannot be found: %s"), argv[0]); + goto out; + } + + ret = setup_revwalk(repo, action, original, &revs); + if (ret < 0) + goto out; + + if (original->parents && original->parents->next) { + ret = error(_("cannot split up merge commit")); + goto out; + } + + ret = split_commit(repo, original, &pathspec, &rewritten); + if (ret < 0) + goto out; + + strbuf_addf(&reflog_msg, "split: updating %s", argv[0]); + + ret = handle_reference_updates(&revs, action, original, rewritten, + reflog_msg.buf, dry_run); + if (ret < 0) { + ret = error(_("failed replaying descendants")); + goto out; + } + + ret = 0; + +out: + strbuf_release(&reflog_msg); + clear_pathspec(&pathspec); + release_revisions(&revs); + return ret; +} + +int cmd_history(int argc, + const char **argv, + const char *prefix, + struct repository *repo) +{ + const char * const usage[] = { + GIT_HISTORY_REWORD_USAGE, + GIT_HISTORY_SPLIT_USAGE, + NULL, + }; + parse_opt_subcommand_fn *fn = NULL; + struct option options[] = { + OPT_SUBCOMMAND("reword", &fn, cmd_history_reword), + OPT_SUBCOMMAND("split", &fn, cmd_history_split), + OPT_END(), + }; + + argc = parse_options(argc, argv, prefix, options, usage, 0); + return fn(argc, argv, prefix, repo); +} |