return retval >= 0 && (tree_difference == REV_TREE_SAME);
}
+struct treesame_state {
+ unsigned int nparents;
+ unsigned char treesame[FLEX_ARRAY];
+};
+
+static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
+{
+ unsigned n = commit_list_count(commit->parents);
+ struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
+ st->nparents = n;
+ add_decoration(&revs->treesame, &commit->object, st);
+ return st;
+}
+
+/*
+ * Must be called immediately after removing the nth_parent from a commit's
+ * parent list, if we are maintaining the per-parent treesame[] decoration.
+ * This does not recalculate the master TREESAME flag - update_treesame()
+ * should be called to update it after a sequence of treesame[] modifications
+ * that may have affected it.
+ */
+static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
+{
+ struct treesame_state *st;
+ int old_same;
+
+ if (!commit->parents) {
+ /*
+ * Have just removed the only parent from a non-merge.
+ * Different handling, as we lack decoration.
+ */
+ if (nth_parent != 0)
+ die("compact_treesame %u", nth_parent);
+ old_same = !!(commit->object.flags & TREESAME);
+ if (rev_same_tree_as_empty(revs, commit))
+ commit->object.flags |= TREESAME;
+ else
+ commit->object.flags &= ~TREESAME;
+ return old_same;
+ }
+
+ st = lookup_decoration(&revs->treesame, &commit->object);
+ if (!st || nth_parent >= st->nparents)
+ die("compact_treesame %u", nth_parent);
+
+ old_same = st->treesame[nth_parent];
+ memmove(st->treesame + nth_parent,
+ st->treesame + nth_parent + 1,
+ st->nparents - nth_parent - 1);
+
+ /*
+ * If we've just become a non-merge commit, update TREESAME
+ * immediately, and remove the no-longer-needed decoration.
+ * If still a merge, defer update until update_treesame().
+ */
+ if (--st->nparents == 1) {
+ if (commit->parents->next)
+ die("compact_treesame parents mismatch");
+ if (st->treesame[0] && revs->dense)
+ commit->object.flags |= TREESAME;
+ else
+ commit->object.flags &= ~TREESAME;
+ free(add_decoration(&revs->treesame, &commit->object, NULL));
+ }
+
+ return old_same;
+}
+
+static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
+{
+ if (commit->parents && commit->parents->next) {
+ unsigned n;
+ struct treesame_state *st;
+
+ st = lookup_decoration(&revs->treesame, &commit->object);
+ if (!st)
+ die("update_treesame %s", sha1_to_hex(commit->object.sha1));
+ commit->object.flags |= TREESAME;
+ for (n = 0; n < st->nparents; n++) {
+ if (!st->treesame[n]) {
+ commit->object.flags &= ~TREESAME;
+ break;
+ }
+ }
+ }
+
+ return commit->object.flags & TREESAME;
+}
+
static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
{
struct commit_list **pp, *parent;
- int tree_changed = 0, tree_same = 0, nth_parent = 0;
+ struct treesame_state *ts = NULL;
+ int tree_changed = 0, nth_parent;
/*
* If we don't do pruning, everything is interesting
if (!revs->dense && !commit->parents->next)
return;
- pp = &commit->parents;
- while ((parent = *pp) != NULL) {
+ for (pp = &commit->parents, nth_parent = 0;
+ (parent = *pp) != NULL;
+ pp = &parent->next, nth_parent++) {
struct commit *p = parent->item;
- /*
- * Do not compare with later parents when we care only about
- * the first parent chain, in order to avoid derailing the
- * traversal to follow a side branch that brought everything
- * in the path we are limited to by the pathspec.
- */
- if (revs->first_parent_only && nth_parent++)
- break;
+ if (nth_parent == 1) {
+ /*
+ * This our second loop iteration - so we now know
+ * we're dealing with a merge.
+ *
+ * Do not compare with later parents when we care only about
+ * the first parent chain, in order to avoid derailing the
+ * traversal to follow a side branch that brought everything
+ * in the path we are limited to by the pathspec.
+ */
+ if (revs->first_parent_only)
+ break;
+ /*
+ * If this will remain a potentially-simplifiable
+ * merge, remember per-parent treesame if needed.
+ * Initialise the array with the comparison from our
+ * first iteration.
+ */
+ if (revs->treesame.name &&
+ !revs->simplify_history &&
+ !(commit->object.flags & UNINTERESTING)) {
+ ts = initialise_treesame(revs, commit);
+ if (!tree_changed)
+ ts->treesame[0] = 1;
+ }
+ }
if (parse_commit(p) < 0)
die("cannot simplify commit %s (because of %s)",
sha1_to_hex(commit->object.sha1),
sha1_to_hex(p->object.sha1));
switch (rev_compare_tree(revs, p, commit)) {
case REV_TREE_SAME:
- tree_same = 1;
if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
/* Even if a merge with an uninteresting
* side branch brought the entire change
* to lose the other branches of this
* merge, so we just keep going.
*/
- pp = &parent->next;
+ if (ts)
+ ts->treesame[nth_parent] = 1;
continue;
}
parent->next = NULL;
case REV_TREE_OLD:
case REV_TREE_DIFFERENT:
tree_changed = 1;
- pp = &parent->next;
continue;
}
die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
}
- if (tree_changed && !tree_same)
+ if (tree_changed)
return;
commit->object.flags |= TREESAME;
}
info->nr++;
}
+static void add_rev_cmdline_list(struct rev_info *revs,
+ struct commit_list *commit_list,
+ int whence,
+ unsigned flags)
+{
+ while (commit_list) {
+ struct object *object = &commit_list->item->object;
+ add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
+ whence, flags);
+ commit_list = commit_list->next;
+ }
+}
+
struct all_refs_cb {
int all_flags;
int warned_bad_reflog;
add_pending_object(revs, &head->object, "HEAD");
add_pending_object(revs, &other->object, "MERGE_HEAD");
bases = get_merge_bases(head, other, 1);
+ add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING);
add_pending_commit_list(revs, bases, UNINTERESTING);
free_commit_list(bases);
head->object.flags |= SYMMETRIC_LEFT;
if (symmetric) {
exclude = get_merge_bases(a, b, 1);
+ add_rev_cmdline_list(revs, exclude,
+ REV_CMD_MERGE_BASE,
+ flags_exclude);
add_pending_commit_list(revs, exclude,
flags_exclude);
free_commit_list(exclude);
}
die("options not supported in --stdin mode");
}
- if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
+ if (handle_revision_arg(xstrdup(sb.buf), revs, 0,
+ REVARG_CANNOT_BE_FILENAME))
die("bad revision '%s'", sb.buf);
}
if (seen_dashdash)
l->next = add_decoration(&revs->children, &parent->object, l);
}
-static int remove_duplicate_parents(struct commit *commit)
+static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
{
+ struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
struct commit_list **pp, *p;
int surviving_parents;
/* Examine existing parents while marking ones we have seen... */
pp = &commit->parents;
+ surviving_parents = 0;
while ((p = *pp) != NULL) {
struct commit *parent = p->item;
if (parent->object.flags & TMP_MARK) {
*pp = p->next;
+ if (ts)
+ compact_treesame(revs, commit, surviving_parents);
continue;
}
parent->object.flags |= TMP_MARK;
+ surviving_parents++;
pp = &p->next;
}
- /* count them while clearing the temporary mark */
- surviving_parents = 0;
+ /* clear the temporary mark */
for (p = commit->parents; p; p = p->next) {
p->item->object.flags &= ~TMP_MARK;
- surviving_parents++;
}
+ /* no update_treesame() - removing duplicates can't affect TREESAME */
return surviving_parents;
}
return st;
}
+static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
+{
+ struct commit_list *h = reduce_heads(commit->parents);
+ int i = 0, marked = 0;
+ struct commit_list *po, *pn;
+
+ /* Want these for sanity-checking only */
+ int orig_cnt = commit_list_count(commit->parents);
+ int cnt = commit_list_count(h);
+
+ /*
+ * Not ready to remove items yet, just mark them for now, based
+ * on the output of reduce_heads(). reduce_heads outputs the reduced
+ * set in its original order, so this isn't too hard.
+ */
+ po = commit->parents;
+ pn = h;
+ while (po) {
+ if (pn && po->item == pn->item) {
+ pn = pn->next;
+ i++;
+ } else {
+ po->item->object.flags |= TMP_MARK;
+ marked++;
+ }
+ po=po->next;
+ }
+
+ if (i != cnt || cnt+marked != orig_cnt)
+ die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
+
+ free_commit_list(h);
+
+ return marked;
+}
+
+/*
+ * Awkward naming - this means one parent we are TREESAME to.
+ * cf mark_treesame_root_parents: root parents that are TREESAME (to an
+ * empty tree). Better name suggestions?
+ */
+static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
+{
+ struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
+ struct commit *unmarked = NULL, *marked = NULL;
+ struct commit_list *p;
+ unsigned n;
+
+ for (p = commit->parents, n = 0; p; p = p->next, n++) {
+ if (ts->treesame[n]) {
+ if (p->item->object.flags & TMP_MARK) {
+ if (!marked)
+ marked = p->item;
+ } else {
+ if (!unmarked) {
+ unmarked = p->item;
+ break;
+ }
+ }
+ }
+ }
+
+ /*
+ * If we are TREESAME to a marked-for-deletion parent, but not to any
+ * unmarked parents, unmark the first TREESAME parent. This is the
+ * parent that the default simplify_history==1 scan would have followed,
+ * and it doesn't make sense to omit that path when asking for a
+ * simplified full history. Retaining it improves the chances of
+ * understanding odd missed merges that took an old version of a file.
+ *
+ * Example:
+ *
+ * I--------*X A modified the file, but mainline merge X used
+ * \ / "-s ours", so took the version from I. X is
+ * `-*A--' TREESAME to I and !TREESAME to A.
+ *
+ * Default log from X would produce "I". Without this check,
+ * --full-history --simplify-merges would produce "I-A-X", showing
+ * the merge commit X and that it changed A, but not making clear that
+ * it had just taken the I version. With this check, the topology above
+ * is retained.
+ *
+ * Note that it is possible that the simplification chooses a different
+ * TREESAME parent from the default, in which case this test doesn't
+ * activate, and we _do_ drop the default parent. Example:
+ *
+ * I------X A modified the file, but it was reverted in B,
+ * \ / meaning mainline merge X is TREESAME to both
+ * *A-*B parents.
+ *
+ * Default log would produce "I" by following the first parent;
+ * --full-history --simplify-merges will produce "I-A-B". But this is a
+ * reasonable result - it presents a logical full history leading from
+ * I to X, and X is not an important merge.
+ */
+ if (!unmarked && marked) {
+ marked->object.flags &= ~TMP_MARK;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
+{
+ struct commit_list **pp, *p;
+ int nth_parent, removed = 0;
+
+ pp = &commit->parents;
+ nth_parent = 0;
+ while ((p = *pp) != NULL) {
+ struct commit *parent = p->item;
+ if (parent->object.flags & TMP_MARK) {
+ parent->object.flags &= ~TMP_MARK;
+ *pp = p->next;
+ free(p);
+ removed++;
+ compact_treesame(revs, commit, nth_parent);
+ continue;
+ }
+ pp = &p->next;
+ nth_parent++;
+ }
+
+ /* Removing parents can only increase TREESAMEness */
+ if (removed && !(commit->object.flags & TREESAME))
+ update_treesame(revs, commit);
+
+ return nth_parent;
+}
+
static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
{
struct commit_list *p;
}
/*
- * Rewrite our list of parents.
+ * Rewrite our list of parents. Note that this cannot
+ * affect our TREESAME flags in any way - a commit is
+ * always TREESAME to its simplification.
*/
for (p = commit->parents; p; p = p->next) {
pst = locate_simplify_state(revs, p->item);
if (revs->first_parent_only)
cnt = 1;
else
- cnt = remove_duplicate_parents(commit);
+ cnt = remove_duplicate_parents(revs, commit);
/*
* It is possible that we are a merge and one side branch
* does not have any commit that touches the given paths;
- * in such a case, the immediate parents will be rewritten
- * to different commits.
+ * in such a case, the immediate parent from that branch
+ * will be rewritten to be the merge base.
*
* o----X X: the commit we are looking at;
* / / o: a commit that touches the paths;
* ---o----'
*
- * Further reduce the parents by removing redundant parents.
+ * Detect and simplify this case.
*/
if (1 < cnt) {
- struct commit_list *h = reduce_heads(commit->parents);
- cnt = commit_list_count(h);
- free_commit_list(commit->parents);
- commit->parents = h;
+ int marked = mark_redundant_parents(revs, commit);
+ if (marked)
+ marked -= leave_one_treesame_to_parent(revs, commit);
+ if (marked)
+ cnt = remove_marked_parents(revs, commit);
}
/*
* A commit simplifies to itself if it is a root, if it is
* UNINTERESTING, if it touches the given paths, or if it is a
- * merge and its parents simplifies to more than one commits
+ * merge and its parents simplify to more than one commit
* (the first two cases are already handled at the beginning of
* this function).
*
if (!revs->leak_pending)
free(list);
+ /* Signal whether we need per-parent treesame decoration */
+ if (revs->simplify_merges)
+ revs->treesame.name = "treesame";
+
if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
commit_list_sort_by_date(&revs->commits);
if (revs->no_walk)
}
pp = &parent->next;
}
- remove_duplicate_parents(commit);
+ remove_duplicate_parents(revs, commit);
return 0;
}
* in it.
*/
encoding = get_log_output_encoding();
- message = logmsg_reencode(commit, encoding);
+ message = logmsg_reencode(commit, NULL, encoding);
/* Copy the commit to temporary if we are using "fake" headers */
if (buf.len)