The sequencer just learned new commands intended to recreate branch
structure (similar in spirit to --preserve-merges, but with a
substantially less-broken design).
Let's allow the rebase--helper to generate todo lists making use of
these commands, triggered by the new --rebase-merges option. For a
commit topology like this (where the HEAD points to C):
- A - B - C
\ /
D
the generated todo list would look like this:
# branch D
pick 0123 A
label branch-point
pick 1234 D
label D
reset branch-point
pick 2345 B
merge -C 3456 D # C
To keep things simple, we first only implement support for merge commits
with exactly two parents, leaving support for octopus merges to a later
patch series.
As a special, hard-coded label, all merge-rebasing todo lists start with
the command `label onto` so that we can later always refer to the revision
onto which everything is rebased.
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
builtin/rebase--helper.c | 4 +-
sequencer.c | 351 ++++++++++++++++++++++++++++++++++++++-
sequencer.h | 1 +
3 files changed, 353 insertions(+), 3 deletions(-)
diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
index ad074705bb5..781782e7272 100644
--- a/builtin/rebase--helper.c
+++ b/builtin/rebase--helper.c
@@ -12,7 +12,7 @@ static const char * const builtin_rebase_helper_usage[] = {
int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
{
struct replay_opts opts = REPLAY_OPTS_INIT;
- unsigned flags = 0, keep_empty = 0;
+ unsigned flags = 0, keep_empty = 0, rebase_merges = 0;
int abbreviate_commands = 0;
enum {
CONTINUE = 1, ABORT, MAKE_SCRIPT, SHORTEN_OIDS, EXPAND_OIDS,
@@ -24,6 +24,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
N_("allow commits with empty messages")),
+ OPT_BOOL(0, "rebase-merges", &rebase_merges, N_("rebase merge commits")),
OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
CONTINUE),
OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
@@ -57,6 +58,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
flags |= keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
+ flags |= rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
flags |= command == SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
if (command == CONTINUE && argc == 1)
diff --git a/sequencer.c b/sequencer.c
index 5944d3a34eb..1e17a11ca32 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -25,6 +25,8 @@
#include "sigchain.h"
#include "unpack-trees.h"
#include "worktree.h"
+#include "oidmap.h"
+#include "oidset.h"
#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
@@ -3436,6 +3438,343 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
strbuf_release(&sob);
}
+struct labels_entry {
+ struct hashmap_entry entry;
+ char label[FLEX_ARRAY];
+};
+
+static int labels_cmp(const void *fndata, const struct labels_entry *a,
+ const struct labels_entry *b, const void *key)
+{
+ return key ? strcmp(a->label, key) : strcmp(a->label, b->label);
+}
+
+struct string_entry {
+ struct oidmap_entry entry;
+ char string[FLEX_ARRAY];
+};
+
+struct label_state {
+ struct oidmap commit2label;
+ struct hashmap labels;
+ struct strbuf buf;
+};
+
+static const char *label_oid(struct object_id *oid, const char *label,
+ struct label_state *state)
+{
+ struct labels_entry *labels_entry;
+ struct string_entry *string_entry;
+ struct object_id dummy;
+ size_t len;
+ int i;
+
+ string_entry = oidmap_get(&state->commit2label, oid);
+ if (string_entry)
+ return string_entry->string;
+
+ /*
+ * For "uninteresting" commits, i.e. commits that are not to be
+ * rebased, and which can therefore not be labeled, we use a unique
+ * abbreviation of the commit name. This is slightly more complicated
+ * than calling find_unique_abbrev() because we also need to make
+ * sure that the abbreviation does not conflict with any other
+ * label.
+ *
+ * We disallow "interesting" commits to be labeled by a string that
+ * is a valid full-length hash, to ensure that we always can find an
+ * abbreviation for any uninteresting commit's names that does not
+ * clash with any other label.
+ */
+ if (!label) {
+ char *p;
+
+ strbuf_reset(&state->buf);
+ strbuf_grow(&state->buf, GIT_SHA1_HEXSZ);
+ label = p = state->buf.buf;
+
+ find_unique_abbrev_r(p, oid, default_abbrev);
+
+ /*
+ * We may need to extend the abbreviated hash so that there is
+ * no conflicting label.
+ */
+ if (hashmap_get_from_hash(&state->labels, strihash(p), p)) {
+ size_t i = strlen(p) + 1;
+
+ oid_to_hex_r(p, oid);
+ for (; i < GIT_SHA1_HEXSZ; i++) {
+ char save = p[i];
+ p[i] = '\0';
+ if (!hashmap_get_from_hash(&state->labels,
+ strihash(p), p))
+ break;
+ p[i] = save;
+ }
+ }
+ } else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
+ !get_oid_hex(label, &dummy)) ||
+ (len == 1 && *label == '#') ||
+ hashmap_get_from_hash(&state->labels,
+ strihash(label), label)) {
+ /*
+ * If the label already exists, or if the label is a valid full
+ * OID, or the label is a '#' (which we use as a separator
+ * between merge heads and oneline), we append a dash and a
+ * number to make it unique.
+ */
+ struct strbuf *buf = &state->buf;
+
+ strbuf_reset(buf);
+ strbuf_add(buf, label, len);
+
+ for (i = 2; ; i++) {
+ strbuf_setlen(buf, len);
+ strbuf_addf(buf, "-%d", i);
+ if (!hashmap_get_from_hash(&state->labels,
+ strihash(buf->buf),
+ buf->buf))
+ break;
+ }
+
+ label = buf->buf;
+ }
+
+ FLEX_ALLOC_STR(labels_entry, label, label);
+ hashmap_entry_init(labels_entry, strihash(label));
+ hashmap_add(&state->labels, labels_entry);
+
+ FLEX_ALLOC_STR(string_entry, string, label);
+ oidcpy(&string_entry->entry.oid, oid);
+ oidmap_put(&state->commit2label, string_entry);
+
+ return string_entry->string;
+}
+
+static int make_script_with_merges(struct pretty_print_context *pp,
+ struct rev_info *revs, FILE *out,
+ unsigned flags)
+{
+ int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
+ struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
+ struct strbuf label = STRBUF_INIT;
+ struct commit_list *commits = NULL, **tail = &commits, *iter;
+ struct commit_list *tips = NULL, **tips_tail = &tips;
+ struct commit *commit;
+ struct oidmap commit2todo = OIDMAP_INIT;
+ struct string_entry *entry;
+ struct oidset interesting = OIDSET_INIT, child_seen = OIDSET_INIT,
+ shown = OIDSET_INIT;
+ struct label_state state = { OIDMAP_INIT, { NULL }, STRBUF_INIT };
+
+ int abbr = flags & TODO_LIST_ABBREVIATE_CMDS;
+ const char *cmd_pick = abbr ? "p" : "pick",
+ *cmd_label = abbr ? "l" : "label",
+ *cmd_reset = abbr ? "t" : "reset",
+ *cmd_merge = abbr ? "m" : "merge";
+
+ oidmap_init(&commit2todo, 0);
+ oidmap_init(&state.commit2label, 0);
+ hashmap_init(&state.labels, (hashmap_cmp_fn) labels_cmp, NULL, 0);
+ strbuf_init(&state.buf, 32);
+
+ if (revs->cmdline.nr && (revs->cmdline.rev[0].flags & BOTTOM)) {
+ struct object_id *oid = &revs->cmdline.rev[0].item->oid;
+ FLEX_ALLOC_STR(entry, string, "onto");
+ oidcpy(&entry->entry.oid, oid);
+ oidmap_put(&state.commit2label, entry);
+ }
+
+ /*
+ * First phase:
+ * - get onelines for all commits
+ * - gather all branch tips (i.e. 2nd or later parents of merges)
+ * - label all branch tips
+ */
+ while ((commit = get_revision(revs))) {
+ struct commit_list *to_merge;
+ int is_octopus;
+ const char *p1, *p2;
+ struct object_id *oid;
+ int is_empty;
+
+ tail = &commit_list_insert(commit, tail)->next;
+ oidset_insert(&interesting, &commit->object.oid);
+
+ is_empty = is_original_commit_empty(commit);
+ if (!is_empty && (commit->object.flags & PATCHSAME))
+ continue;
+
+ strbuf_reset(&oneline);
+ pretty_print_commit(pp, commit, &oneline);
+
+ to_merge = commit->parents ? commit->parents->next : NULL;
+ if (!to_merge) {
+ /* non-merge commit: easy case */
+ strbuf_reset(&buf);
+ if (!keep_empty && is_empty)
+ strbuf_addf(&buf, "%c ", comment_line_char);
+ strbuf_addf(&buf, "%s %s %s", cmd_pick,
+ oid_to_hex(&commit->object.oid),
+ oneline.buf);
+
+ FLEX_ALLOC_STR(entry, string, buf.buf);
+ oidcpy(&entry->entry.oid, &commit->object.oid);
+ oidmap_put(&commit2todo, entry);
+
+ continue;
+ }
+
+ is_octopus = to_merge && to_merge->next;
+
+ if (is_octopus)
+ BUG("Octopus merges not yet supported");
+
+ /* Create a label */
+ strbuf_reset(&label);
+ if (skip_prefix(oneline.buf, "Merge ", &p1) &&
+ (p1 = strchr(p1, '\'')) &&
+ (p2 = strchr(++p1, '\'')))
+ strbuf_add(&label, p1, p2 - p1);
+ else if (skip_prefix(oneline.buf, "Merge pull request ",
+ &p1) &&
+ (p1 = strstr(p1, " from ")))
+ strbuf_addstr(&label, p1 + strlen(" from "));
+ else
+ strbuf_addbuf(&label, &oneline);
+
+ for (p1 = label.buf; *p1; p1++)
+ if (isspace(*p1))
+ *(char *)p1 = '-';
+
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "%s -C %s",
+ cmd_merge, oid_to_hex(&commit->object.oid));
+
+ /* label the tip of merged branch */
+ oid = &to_merge->item->object.oid;
+ strbuf_addch(&buf, ' ');
+
+ if (!oidset_contains(&interesting, oid))
+ strbuf_addstr(&buf, label_oid(oid, NULL, &state));
+ else {
+ tips_tail = &commit_list_insert(to_merge->item,
+ tips_tail)->next;
+
+ strbuf_addstr(&buf, label_oid(oid, label.buf, &state));
+ }
+ strbuf_addf(&buf, " # %s", oneline.buf);
+
+ FLEX_ALLOC_STR(entry, string, buf.buf);
+ oidcpy(&entry->entry.oid, &commit->object.oid);
+ oidmap_put(&commit2todo, entry);
+ }
+
+ /*
+ * Second phase:
+ * - label branch points
+ * - add HEAD to the branch tips
+ */
+ for (iter = commits; iter; iter = iter->next) {
+ struct commit_list *parent = iter->item->parents;
+ for (; parent; parent = parent->next) {
+ struct object_id *oid = &parent->item->object.oid;
+ if (!oidset_contains(&interesting, oid))
+ continue;
+ if (!oidset_contains(&child_seen, oid))
+ oidset_insert(&child_seen, oid);
+ else
+ label_oid(oid, "branch-point", &state);
+ }
+
+ /* Add HEAD as implict "tip of branch" */
+ if (!iter->next)
+ tips_tail = &commit_list_insert(iter->item,
+ tips_tail)->next;
+ }
+
+ /*
+ * Third phase: output the todo list. This is a bit tricky, as we
+ * want to avoid jumping back and forth between revisions. To
+ * accomplish that goal, we walk backwards from the branch tips,
+ * gathering commits not yet shown, reversing the list on the fly,
+ * then outputting that list (labeling revisions as needed).
+ */
+ fprintf(out, "%s onto\n", cmd_label);
+ for (iter = tips; iter; iter = iter->next) {
+ struct commit_list *list = NULL, *iter2;
+
+ commit = iter->item;
+ if (oidset_contains(&shown, &commit->object.oid))
+ continue;
+ entry = oidmap_get(&state.commit2label, &commit->object.oid);
+
+ if (entry)
+ fprintf(out, "\n# Branch %s\n", entry->string);
+ else
+ fprintf(out, "\n");
+
+ while (oidset_contains(&interesting, &commit->object.oid) &&
+ !oidset_contains(&shown, &commit->object.oid)) {
+ commit_list_insert(commit, &list);
+ if (!commit->parents) {
+ commit = NULL;
+ break;
+ }
+ commit = commit->parents->item;
+ }
+
+ if (!commit)
+ fprintf(out, "%s onto\n", cmd_reset);
+ else {
+ const char *to = NULL;
+
+ entry = oidmap_get(&state.commit2label,
+ &commit->object.oid);
+ if (entry)
+ to = entry->string;
+
+ if (!to || !strcmp(to, "onto"))
+ fprintf(out, "%s onto\n", cmd_reset);
+ else {
+ strbuf_reset(&oneline);
+ pretty_print_commit(pp, commit, &oneline);
+ fprintf(out, "%s %s # %s\n",
+ cmd_reset, to, oneline.buf);
+ }
+ }
+
+ for (iter2 = list; iter2; iter2 = iter2->next) {
+ struct object_id *oid = &iter2->item->object.oid;
+ entry = oidmap_get(&commit2todo, oid);
+ /* only show if not already upstream */
+ if (entry)
+ fprintf(out, "%s\n", entry->string);
+ entry = oidmap_get(&state.commit2label, oid);
+ if (entry)
+ fprintf(out, "%s %s\n",
+ cmd_label, entry->string);
+ oidset_insert(&shown, oid);
+ }
+
+ free_commit_list(list);
+ }
+
+ free_commit_list(commits);
+ free_commit_list(tips);
+
+ strbuf_release(&label);
+ strbuf_release(&oneline);
+ strbuf_release(&buf);
+
+ oidmap_free(&commit2todo, 1);
+ oidmap_free(&state.commit2label, 1);
+ hashmap_free(&state.labels, 1);
+ strbuf_release(&state.buf);
+
+ return 0;
+}
+
int sequencer_make_script(FILE *out, int argc, const char **argv,
unsigned flags)
{
@@ -3446,11 +3785,16 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
struct commit *commit;
int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
+ int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
init_revisions(&revs, NULL);
revs.verbose_header = 1;
- revs.max_parents = 1;
- revs.cherry_pick = 1;
+ if (rebase_merges)
+ revs.cherry_mark = 1;
+ else {
+ revs.max_parents = 1;
+ revs.cherry_pick = 1;
+ }
revs.limited = 1;
revs.reverse = 1;
revs.right_only = 1;
@@ -3474,6 +3818,9 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
if (prepare_revision_walk(&revs) < 0)
return error(_("make_script: error preparing revisions"));
+ if (rebase_merges)
+ return make_script_with_merges(&pp, &revs, out, flags);
+
while ((commit = get_revision(&revs))) {
strbuf_reset(&buf);
if (!keep_empty && is_original_commit_empty(commit))
diff --git a/sequencer.h b/sequencer.h
index e45b178dfc4..6bc4da17243 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -59,6 +59,7 @@ int sequencer_remove_state(struct replay_opts *opts);
#define TODO_LIST_KEEP_EMPTY (1U << 0)
#define TODO_LIST_SHORTEN_IDS (1U << 1)
#define TODO_LIST_ABBREVIATE_CMDS (1U << 2)
+#define TODO_LIST_REBASE_MERGES (1U << 3)
int sequencer_make_script(FILE *out, int argc, const char **argv,
unsigned flags);
--
2.17.0.windows.1.15.gaa56ade3205
