diff options
Diffstat (limited to 'builtin/history.c')
| -rw-r--r-- | builtin/history.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/builtin/history.c b/builtin/history.c new file mode 100644 index 0000000000..cae841707d --- /dev/null +++ b/builtin/history.c @@ -0,0 +1,561 @@ +#define USE_THE_REPOSITORY_VARIABLE + +#include "builtin.h" +#include "cache-tree.h" +#include "commit-reach.h" +#include "commit.h" +#include "config.h" +#include "editor.h" +#include "environment.h" +#include "gettext.h" +#include "hex.h" +#include "oidmap.h" +#include "parse-options.h" +#include "path.h" +#include "read-cache.h" +#include "refs.h" +#include "replay.h" +#include "reset.h" +#include "revision.h" +#include "run-command.h" +#include "sequencer.h" +#include "strvec.h" +#include "tree.h" +#include "wt-status.h" + +#define GIT_HISTORY_REWORD_USAGE N_("git history reword <commit>") +#define GIT_HISTORY_SPLIT_USAGE N_("git history split <commit> [--] [<pathspec>...]") + +static int collect_commits(struct repository *repo, + struct commit *old_commit, + struct commit *new_commit, + struct strvec *out) +{ + struct setup_revision_opt revision_opts = { + .assume_dashdash = 1, + }; + struct strvec revisions = STRVEC_INIT; + struct commit *child; + struct rev_info rev = { 0 }; + int ret; + + repo_init_revisions(repo, &rev, NULL); + strvec_push(&revisions, ""); + strvec_push(&revisions, oid_to_hex(&new_commit->object.oid)); + if (old_commit) + strvec_pushf(&revisions, "^%s", oid_to_hex(&old_commit->object.oid)); + + setup_revisions_from_strvec(&revisions, &rev, &revision_opts); + if (revisions.nr != 1 || prepare_revision_walk(&rev)) { + ret = error(_("revision walk setup failed")); + goto out; + } + + while ((child = get_revision(&rev))) { + if (old_commit && !child->parents) + BUG("revision walk did not find child commit"); + if (child->parents && child->parents->next) { + ret = error(_("cannot rearrange commit history with merges")); + goto out; + } + + strvec_push(out, oid_to_hex(&child->object.oid)); + + if (child->parents && old_commit && + commit_list_contains(old_commit, child->parents)) + break; + } + + /* + * Revisions are in newest-order-first. We have to reverse the + * array though so that we pick the oldest commits first. + */ + for (size_t i = 0, j = out->nr - 1; i < j; i++, j--) + SWAP(out->v[i], out->v[j]); + + ret = 0; + +out: + strvec_clear(&revisions); + release_revisions(&rev); + reset_revision_walk(); + return ret; +} + +static void replace_commits(struct strvec *commits, + const struct object_id *commit_to_replace, + const struct object_id *replacements, + size_t replacements_nr) +{ + char commit_to_replace_oid[GIT_MAX_HEXSZ + 1]; + struct strvec replacement_oids = STRVEC_INIT; + bool found = false; + + oid_to_hex_r(commit_to_replace_oid, commit_to_replace); + for (size_t i = 0; i < replacements_nr; i++) + strvec_push(&replacement_oids, oid_to_hex(&replacements[i])); + + for (size_t i = 0; i < commits->nr; i++) { + if (strcmp(commits->v[i], commit_to_replace_oid)) + continue; + strvec_splice(commits, i, 1, replacement_oids.v, replacement_oids.nr); + found = true; + break; + } + if (!found) + BUG("could not find commit to replace"); + + strvec_clear(&replacement_oids); +} + +static int apply_commits(struct repository *repo, + const struct strvec *commits, + struct commit *onto, + struct commit *orig_head, + const char *action) +{ + struct reset_head_opts reset_opts = { 0 }; + struct strbuf buf = STRBUF_INIT; + int ret; + + for (size_t i = 0; i < commits->nr; i++) { + struct object_id commit_id; + struct commit *commit; + const char *end; + + if (parse_oid_hex_algop(commits->v[i], &commit_id, &end, + repo->hash_algo)) { + ret = error(_("invalid object ID: %s"), commits->v[i]); + goto out; + } + + commit = lookup_commit(repo, &commit_id); + if (!commit || repo_parse_commit(repo, commit)) { + ret = error(_("failed to look up commit: %s"), oid_to_hex(&commit_id)); + goto out; + } + + if (!onto) { + onto = commit; + } else { + struct tree *tree = repo_get_commit_tree(repo, commit); + onto = replay_create_commit(repo, tree, commit, onto); + if (!onto) + break; + } + } + + reset_opts.oid = &onto->object.oid; + strbuf_addf(&buf, "%s: switch to rewritten %s", action, oid_to_hex(reset_opts.oid)); + reset_opts.flags = RESET_HEAD_REFS_ONLY | RESET_ORIG_HEAD; + reset_opts.orig_head = &orig_head->object.oid; + reset_opts.default_reflog_action = action; + if (reset_head(repo, &reset_opts) < 0) { + ret = error(_("could not switch to %s"), oid_to_hex(reset_opts.oid)); + goto out; + } + + ret = 0; + +out: + strbuf_release(&buf); + return ret; +} + +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.\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, _("Please supply the message using the -m option.\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 cmd_history_reword(int argc, + const char **argv, + const char *prefix, + struct repository *repo) +{ + const char * const usage[] = { + GIT_HISTORY_REWORD_USAGE, + NULL, + }; + struct option options[] = { + OPT_END(), + }; + struct strbuf final_message = STRBUF_INIT; + struct commit *original_commit, *parent, *head; + struct strvec commits = STRVEC_INIT; + struct object_id parent_tree_oid, original_commit_tree_oid; + struct object_id rewritten_commit; + struct commit_list *from_list = NULL; + const char *original_message, *original_body, *ptr; + char *original_author = NULL; + size_t len; + 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); + + original_commit = lookup_commit_reference_by_name(argv[0]); + if (!original_commit) { + ret = error(_("commit to be reworded cannot be found: %s"), argv[0]); + goto out; + } + original_commit_tree_oid = repo_get_commit_tree(repo, original_commit)->object.oid; + + parent = original_commit->parents ? original_commit->parents->item : NULL; + if (parent) { + if (repo_parse_commit(repo, parent)) { + ret = error(_("unable to parse commit %s"), + oid_to_hex(&parent->object.oid)); + goto out; + } + parent_tree_oid = repo_get_commit_tree(repo, parent)->object.oid; + } else { + oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree); + } + + head = lookup_commit_reference_by_name("HEAD"); + if (!head) { + ret = error(_("could not resolve HEAD to a commit")); + goto out; + } + + commit_list_append(original_commit, &from_list); + if (!repo_is_descendant_of(repo, head, from_list)) { + ret = error (_("split commit must be reachable from current HEAD commit")); + goto out; + } + + /* + * Collect the list of commits that we'll have to reapply now already. + * This ensures that we'll abort early on in case the range of commits + * contains merges, which we do not yet handle. + */ + ret = collect_commits(repo, parent, head, &commits); + if (ret < 0) + goto out; + + /* We retain authorship of the original commit. */ + original_message = repo_logmsg_reencode(repo, original_commit, 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, &parent_tree_oid, &original_commit_tree_oid, + original_body, "reworded", &final_message); + if (ret < 0) + goto out; + + ret = commit_tree(final_message.buf, final_message.len, &original_commit_tree_oid, + original_commit->parents, &rewritten_commit, original_author, NULL); + if (ret < 0) { + ret = error(_("failed writing reworded commit")); + goto out; + } + + replace_commits(&commits, &original_commit->object.oid, &rewritten_commit, 1); + + ret = apply_commits(repo, &commits, parent, head, "reword"); + if (ret < 0) + goto out; + + ret = 0; + +out: + strbuf_release(&final_message); + free_commit_list(from_list); + strvec_clear(&commits); + free(original_author); + return ret; +} + +static int split_commit(struct repository *repo, + struct commit *original_commit, + struct pathspec *pathspec, + struct object_id *out) +{ + struct interactive_options interactive_opts = INTERACTIVE_OPTIONS_INIT; + struct strbuf index_file = STRBUF_INIT, split_message = STRBUF_INIT; + struct child_process read_tree_cmd = CHILD_PROCESS_INIT; + struct index_state index = INDEX_STATE_INIT(repo); + struct object_id original_commit_tree_oid, parent_tree_oid; + const char *original_message, *original_body, *ptr; + char original_commit_oid[GIT_MAX_HEXSZ + 1]; + char *original_author = NULL; + struct commit_list *parents = NULL; + struct commit *first_commit; + struct tree *split_tree; + size_t len; + int ret; + + if (original_commit->parents) + parent_tree_oid = *get_commit_tree_oid(original_commit->parents->item); + else + oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree); + original_commit_tree_oid = *get_commit_tree_oid(original_commit); + + /* + * 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"); + + read_tree_cmd.git_cmd = 1; + strvec_pushf(&read_tree_cmd.env, "GIT_INDEX_FILE=%s", index_file.buf); + strvec_push(&read_tree_cmd.args, "read-tree"); + strvec_push(&read_tree_cmd.args, oid_to_hex(&parent_tree_oid)); + ret = run_command(&read_tree_cmd); + 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_commit->object.oid); + ret = run_add_p_index(repo, &index, index_file.buf, &interactive_opts, + original_commit_oid, pathspec); + 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); + + /* + * 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; + } + + /* We retain authorship of the original commit. */ + original_message = repo_logmsg_reencode(repo, original_commit, NULL, NULL); + ptr = find_commit_header(original_message, "author", &len); + if (ptr) + original_author = xmemdupz(ptr, len); + + ret = fill_commit_message(repo, &parent_tree_oid, &split_tree->object.oid, + "", "split-out", &split_message); + if (ret < 0) + goto out; + + ret = commit_tree(split_message.buf, split_message.len, &split_tree->object.oid, + original_commit->parents, &out[0], original_author, NULL); + if (ret < 0) { + ret = error(_("failed writing split-out commit")); + goto out; + } + + /* + * The second commit is much simpler to construct, as we can simply use + * the original commit details, except that we adjust its parent to be + * the newly split-out commit. + */ + find_commit_subject(original_message, &original_body); + first_commit = lookup_commit_reference(repo, &out[0]); + commit_list_append(first_commit, &parents); + + ret = commit_tree(original_body, strlen(original_body), &original_commit_tree_oid, + parents, &out[1], original_author, NULL); + if (ret < 0) { + ret = error(_("failed writing second commit")); + goto out; + } + + ret = 0; + +out: + if (index_file.len) + unlink(index_file.buf); + strbuf_release(&split_message); + strbuf_release(&index_file); + free_commit_list(parents); + free(original_author); + 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, + }; + struct option options[] = { + OPT_END(), + }; + struct oidmap rewritten_commits = OIDMAP_INIT; + struct commit *original_commit, *parent, *head; + struct strvec commits = STRVEC_INIT; + struct commit_list *from_list = NULL; + struct object_id split_commits[2]; + struct pathspec pathspec = { 0 }; + int ret; + + argc = parse_options(argc, argv, prefix, options, usage, 0); + if (argc < 1) { + ret = error(_("command expects a revision")); + goto out; + } + repo_config(repo, git_default_config, NULL); + + original_commit = lookup_commit_reference_by_name(argv[0]); + if (!original_commit) { + ret = error(_("commit to be split cannot be found: %s"), argv[0]); + goto out; + } + + parent = original_commit->parents ? original_commit->parents->item : NULL; + if (parent && repo_parse_commit(repo, parent)) { + ret = error(_("unable to parse commit %s"), + oid_to_hex(&parent->object.oid)); + goto out; + } + + head = lookup_commit_reference_by_name("HEAD"); + if (!head) { + ret = error(_("could not resolve HEAD to a commit")); + goto out; + } + + commit_list_append(original_commit, &from_list); + if (!repo_is_descendant_of(repo, head, from_list)) { + ret = error(_("split commit must be reachable from current HEAD commit")); + goto out; + } + + parse_pathspec(&pathspec, 0, + PATHSPEC_PREFER_FULL | PATHSPEC_SYMLINK_LEADING_PATH | PATHSPEC_PREFIX_ORIGIN, + prefix, argv + 1); + + /* + * Collect the list of commits that we'll have to reapply now already. + * This ensures that we'll abort early on in case the range of commits + * contains merges, which we do not yet handle. + */ + ret = collect_commits(repo, parent, head, &commits); + if (ret < 0) + goto out; + + /* + * Then we split up the commit and replace the original commit with the + * new ones. + */ + ret = split_commit(repo, original_commit, &pathspec, split_commits); + if (ret < 0) + goto out; + + replace_commits(&commits, &original_commit->object.oid, + split_commits, ARRAY_SIZE(split_commits)); + + ret = apply_commits(repo, &commits, parent, head, "split"); + if (ret < 0) + goto out; + + ret = 0; + +out: + oidmap_clear(&rewritten_commits, 0); + free_commit_list(from_list); + clear_pathspec(&pathspec); + strvec_clear(&commits); + 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); +} |