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authorJunio C Hamano <gitster@pobox.com>2013-06-14 08:45:59 -0700
committerJunio C Hamano <gitster@pobox.com>2013-06-14 08:45:59 -0700
commitb27a79d16b21be064c0ac3634928a91e3eee5c01 (patch)
treee9f75de0da78552765dc5fae1451402e78c36797 /revision.c
parent91d34bc47ba6ed51a35fa3bb84d674b624d3f447 (diff)
parent141efdba57b1769fc60ff9a3925afbc6af398faf (diff)
downloadgit-b27a79d16b21be064c0ac3634928a91e3eee5c01.tar.gz
Merge branch 'kb/full-history-compute-treesame-carefully-2'
Major update to the revision traversal logic to improve culling of irrelevant parents while traversing a mergy history. * kb/full-history-compute-treesame-carefully-2: revision.c: make default history consider bottom commits revision.c: don't show all merges for --parents revision.c: discount side branches when computing TREESAME revision.c: add BOTTOM flag for commits simplify-merges: drop merge from irrelevant side branch simplify-merges: never remove all TREESAME parents t6012: update test for tweaked full-history traversal revision.c: Make --full-history consider more merges Documentation: avoid "uninteresting" rev-list-options.txt: correct TREESAME for P t6111: add parents to tests t6111: allow checking the parents as well t6111: new TREESAME test set t6019: test file dropped in -s ours merge decorate.c: compact table when growing
Diffstat (limited to 'revision.c')
-rw-r--r--revision.c539
1 files changed, 474 insertions, 65 deletions
diff --git a/revision.c b/revision.c
index 518cd08693..9318b7d763 100644
--- a/revision.c
+++ b/revision.c
@@ -334,6 +334,80 @@ static int everybody_uninteresting(struct commit_list *orig)
}
/*
+ * A definition of "relevant" commit that we can use to simplify limited graphs
+ * by eliminating side branches.
+ *
+ * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
+ * in our list), or that is a specified BOTTOM commit. Then after computing
+ * a limited list, during processing we can generally ignore boundary merges
+ * coming from outside the graph, (ie from irrelevant parents), and treat
+ * those merges as if they were single-parent. TREESAME is defined to consider
+ * only relevant parents, if any. If we are TREESAME to our on-graph parents,
+ * we don't care if we were !TREESAME to non-graph parents.
+ *
+ * Treating bottom commits as relevant ensures that a limited graph's
+ * connection to the actual bottom commit is not viewed as a side branch, but
+ * treated as part of the graph. For example:
+ *
+ * ....Z...A---X---o---o---B
+ * . /
+ * W---Y
+ *
+ * When computing "A..B", the A-X connection is at least as important as
+ * Y-X, despite A being flagged UNINTERESTING.
+ *
+ * And when computing --ancestry-path "A..B", the A-X connection is more
+ * important than Y-X, despite both A and Y being flagged UNINTERESTING.
+ */
+static inline int relevant_commit(struct commit *commit)
+{
+ return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
+}
+
+/*
+ * Return a single relevant commit from a parent list. If we are a TREESAME
+ * commit, and this selects one of our parents, then we can safely simplify to
+ * that parent.
+ */
+static struct commit *one_relevant_parent(const struct rev_info *revs,
+ struct commit_list *orig)
+{
+ struct commit_list *list = orig;
+ struct commit *relevant = NULL;
+
+ if (!orig)
+ return NULL;
+
+ /*
+ * For 1-parent commits, or if first-parent-only, then return that
+ * first parent (even if not "relevant" by the above definition).
+ * TREESAME will have been set purely on that parent.
+ */
+ if (revs->first_parent_only || !orig->next)
+ return orig->item;
+
+ /*
+ * For multi-parent commits, identify a sole relevant parent, if any.
+ * If we have only one relevant parent, then TREESAME will be set purely
+ * with regard to that parent, and we can simplify accordingly.
+ *
+ * If we have more than one relevant parent, or no relevant parents
+ * (and multiple irrelevant ones), then we can't select a parent here
+ * and return NULL.
+ */
+ while (list) {
+ struct commit *commit = list->item;
+ list = list->next;
+ if (relevant_commit(commit)) {
+ if (relevant)
+ return NULL;
+ relevant = commit;
+ }
+ }
+ return relevant;
+}
+
+/*
* The goal is to get REV_TREE_NEW as the result only if the
* diff consists of all '+' (and no other changes), REV_TREE_OLD
* if the whole diff is removal of old data, and otherwise
@@ -430,10 +504,125 @@ static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
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;
+ struct commit_list *p;
+ unsigned relevant_parents;
+ unsigned relevant_change, irrelevant_change;
+
+ st = lookup_decoration(&revs->treesame, &commit->object);
+ if (!st)
+ die("update_treesame %s", sha1_to_hex(commit->object.sha1));
+ relevant_parents = 0;
+ relevant_change = irrelevant_change = 0;
+ for (p = commit->parents, n = 0; p; n++, p = p->next) {
+ if (relevant_commit(p->item)) {
+ relevant_change |= !st->treesame[n];
+ relevant_parents++;
+ } else
+ irrelevant_change |= !st->treesame[n];
+ }
+ if (relevant_parents ? relevant_change : irrelevant_change)
+ commit->object.flags &= ~TREESAME;
+ else
+ commit->object.flags |= TREESAME;
+ }
+
+ return commit->object.flags & TREESAME;
+}
+
+static inline int limiting_can_increase_treesame(const struct rev_info *revs)
+{
+ /*
+ * TREESAME is irrelevant unless prune && dense;
+ * if simplify_history is set, we can't have a mixture of TREESAME and
+ * !TREESAME INTERESTING parents (and we don't have treesame[]
+ * decoration anyway);
+ * if first_parent_only is set, then the TREESAME flag is locked
+ * against the first parent (and again we lack treesame[] decoration).
+ */
+ return revs->prune && revs->dense &&
+ !revs->simplify_history &&
+ !revs->first_parent_only;
+}
+
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 relevant_change = 0, irrelevant_change = 0;
+ int relevant_parents, nth_parent;
/*
* If we don't do pruning, everything is interesting
@@ -457,33 +646,54 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
if (!revs->dense && !commit->parents->next)
return;
- pp = &commit->parents;
- while ((parent = *pp) != NULL) {
+ for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
+ (parent = *pp) != NULL;
+ pp = &parent->next, nth_parent++) {
struct commit *p = parent->item;
+ if (relevant_commit(p))
+ relevant_parents++;
- /*
- * 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 (!(irrelevant_change || relevant_change))
+ 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)) {
+ if (!revs->simplify_history || !relevant_commit(p)) {
/* Even if a merge with an uninteresting
* side branch brought the entire change
* we are interested in, we do not want
* 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;
@@ -511,15 +721,27 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
/* fallthrough */
case REV_TREE_OLD:
case REV_TREE_DIFFERENT:
- tree_changed = 1;
- pp = &parent->next;
+ if (relevant_commit(p))
+ relevant_change = 1;
+ else
+ irrelevant_change = 1;
continue;
}
die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
}
- if (tree_changed && !tree_same)
- return;
- commit->object.flags |= TREESAME;
+
+ /*
+ * TREESAME is straightforward for single-parent commits. For merge
+ * commits, it is most useful to define it so that "irrelevant"
+ * parents cannot make us !TREESAME - if we have any relevant
+ * parents, then we only consider TREESAMEness with respect to them,
+ * allowing irrelevant merges from uninteresting branches to be
+ * simplified away. Only if we have only irrelevant parents do we
+ * base TREESAME on them. Note that this logic is replicated in
+ * update_treesame, which should be kept in sync.
+ */
+ if (relevant_parents ? !relevant_change : !irrelevant_change)
+ commit->object.flags |= TREESAME;
}
static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
@@ -802,16 +1024,12 @@ static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *li
* to filter the result of "A..B" further to the ones that can actually
* reach A.
*/
-static struct commit_list *collect_bottom_commits(struct rev_info *revs)
+static struct commit_list *collect_bottom_commits(struct commit_list *list)
{
- struct commit_list *bottom = NULL;
- int i;
- for (i = 0; i < revs->cmdline.nr; i++) {
- struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
- if ((elem->flags & UNINTERESTING) &&
- elem->item->type == OBJ_COMMIT)
- commit_list_insert((struct commit *)elem->item, &bottom);
- }
+ struct commit_list *elem, *bottom = NULL;
+ for (elem = list; elem; elem = elem->next)
+ if (elem->item->object.flags & BOTTOM)
+ commit_list_insert(elem->item, &bottom);
return bottom;
}
@@ -842,7 +1060,7 @@ static int limit_list(struct rev_info *revs)
struct commit_list *bottom = NULL;
if (revs->ancestry_path) {
- bottom = collect_bottom_commits(revs);
+ bottom = collect_bottom_commits(list);
if (!bottom)
die("--ancestry-path given but there are no bottom commits");
}
@@ -895,6 +1113,18 @@ static int limit_list(struct rev_info *revs)
free_commit_list(bottom);
}
+ /*
+ * Check if any commits have become TREESAME by some of their parents
+ * becoming UNINTERESTING.
+ */
+ if (limiting_can_increase_treesame(revs))
+ for (list = newlist; list; list = list->next) {
+ struct commit *c = list->item;
+ if (c->object.flags & (UNINTERESTING | TREESAME))
+ continue;
+ update_treesame(revs, c);
+ }
+
revs->commits = newlist;
return 0;
}
@@ -1014,7 +1244,7 @@ static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
const char *arg = arg_;
if (*arg == '^') {
- flags ^= UNINTERESTING;
+ flags ^= UNINTERESTING | BOTTOM;
arg++;
}
if (get_sha1_committish(arg, sha1))
@@ -1106,8 +1336,8 @@ static void prepare_show_merge(struct rev_info *revs)
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);
+ add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
+ add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
free_commit_list(bases);
head->object.flags |= SYMMETRIC_LEFT;
@@ -1143,13 +1373,15 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
unsigned get_sha1_flags = 0;
+ flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
+
dotdot = strstr(arg, "..");
if (dotdot) {
unsigned char from_sha1[20];
const char *next = dotdot + 2;
const char *this = arg;
int symmetric = *next == '.';
- unsigned int flags_exclude = flags ^ UNINTERESTING;
+ unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
static const char head_by_default[] = "HEAD";
unsigned int a_flags;
@@ -1225,13 +1457,13 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
dotdot = strstr(arg, "^!");
if (dotdot && !dotdot[2]) {
*dotdot = 0;
- if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
+ if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
*dotdot = '^';
}
local_flags = 0;
if (*arg == '^') {
- local_flags = UNINTERESTING;
+ local_flags = UNINTERESTING | BOTTOM;
arg++;
}
@@ -1708,7 +1940,7 @@ static int handle_revision_pseudo_opt(const char *submodule,
handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
} else if (!strcmp(arg, "--bisect")) {
handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
- handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
+ handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
revs->bisect = 1;
} else if (!strcmp(arg, "--tags")) {
handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
@@ -1734,7 +1966,7 @@ static int handle_revision_pseudo_opt(const char *submodule,
} else if (!strcmp(arg, "--reflog")) {
handle_reflog(revs, *flags);
} else if (!strcmp(arg, "--not")) {
- *flags ^= UNINTERESTING;
+ *flags ^= UNINTERESTING | BOTTOM;
} else if (!strcmp(arg, "--no-walk")) {
revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
} else if (!prefixcmp(arg, "--no-walk=")) {
@@ -1954,28 +2186,32 @@ static void add_child(struct rev_info *revs, struct commit *parent, struct commi
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;
}
@@ -1995,9 +2231,157 @@ static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs,
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;
+}
+
+static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
+{
+ struct commit_list *p;
+ int marked = 0;
+
+ for (p = commit->parents; p; p = p->next) {
+ struct commit *parent = p->item;
+ if (!parent->parents && (parent->object.flags & TREESAME)) {
+ parent->object.flags |= TMP_MARK;
+ marked++;
+ }
+ }
+
+ 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;
+ struct commit *parent;
struct merge_simplify_state *st, *pst;
int cnt;
@@ -2039,7 +2423,9 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c
}
/*
- * 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);
@@ -2051,43 +2437,53 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c
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.
+ * Further, a merge of an independent branch that doesn't
+ * touch the path will reduce to a treesame root parent:
+ *
+ * ----o----X X: the commit we are looking at;
+ * / o: a commit that touches the paths;
+ * r r: a root commit not touching the paths
+ *
+ * Detect and simplify both cases.
*/
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);
+ marked += mark_treesame_root_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 don't simplify to one relevant commit
* (the first two cases are already handled at the beginning of
* this function).
*
- * Otherwise, it simplifies to what its sole parent simplifies to.
+ * Otherwise, it simplifies to what its sole relevant parent
+ * simplifies to.
*/
if (!cnt ||
(commit->object.flags & UNINTERESTING) ||
!(commit->object.flags & TREESAME) ||
- (1 < cnt))
+ (parent = one_relevant_parent(revs, commit->parents)) == NULL)
st->simplified = commit;
else {
- pst = locate_simplify_state(revs, commit->parents->item);
+ pst = locate_simplify_state(revs, parent);
st->simplified = pst->simplified;
}
return tail;
@@ -2183,6 +2579,11 @@ int prepare_revision_walk(struct rev_info *revs)
if (!revs->leak_pending)
free(list);
+ /* Signal whether we need per-parent treesame decoration */
+ if (revs->simplify_merges ||
+ (revs->limited && limiting_can_increase_treesame(revs)))
+ revs->treesame.name = "treesame";
+
if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
commit_list_sort_by_date(&revs->commits);
if (revs->no_walk)
@@ -2210,15 +2611,15 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp
if (!revs->limited)
if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
return rewrite_one_error;
- if (p->parents && p->parents->next)
- return rewrite_one_ok;
if (p->object.flags & UNINTERESTING)
return rewrite_one_ok;
if (!(p->object.flags & TREESAME))
return rewrite_one_ok;
if (!p->parents)
return rewrite_one_noparents;
- *pp = p->parents->item;
+ if ((p = one_relevant_parent(revs, p->parents)) == NULL)
+ return rewrite_one_ok;
+ *pp = p;
}
}
@@ -2239,7 +2640,7 @@ int rewrite_parents(struct rev_info *revs, struct commit *commit,
}
pp = &parent->next;
}
- remove_duplicate_parents(commit);
+ remove_duplicate_parents(revs, commit);
return 0;
}
@@ -2363,10 +2764,7 @@ enum commit_action get_commit_action(struct rev_info *revs, struct commit *commi
if (revs->min_age != -1 && (commit->date > revs->min_age))
return commit_ignore;
if (revs->min_parents || (revs->max_parents >= 0)) {
- int n = 0;
- struct commit_list *p;
- for (p = commit->parents; p; p = p->next)
- n++;
+ int n = commit_list_count(commit->parents);
if ((n < revs->min_parents) ||
((revs->max_parents >= 0) && (n > revs->max_parents)))
return commit_ignore;
@@ -2376,12 +2774,23 @@ enum commit_action get_commit_action(struct rev_info *revs, struct commit *commi
if (revs->prune && revs->dense) {
/* Commit without changes? */
if (commit->object.flags & TREESAME) {
+ int n;
+ struct commit_list *p;
/* drop merges unless we want parenthood */
if (!want_ancestry(revs))
return commit_ignore;
- /* non-merge - always ignore it */
- if (!commit->parents || !commit->parents->next)
- return commit_ignore;
+ /*
+ * If we want ancestry, then need to keep any merges
+ * between relevant commits to tie together topology.
+ * For consistency with TREESAME and simplification
+ * use "relevant" here rather than just INTERESTING,
+ * to treat bottom commit(s) as part of the topology.
+ */
+ for (n = 0, p = commit->parents; p; p = p->next)
+ if (relevant_commit(p->item))
+ if (++n >= 2)
+ return commit_show;
+ return commit_ignore;
}
}
return commit_show;