revision: allow --ancestry-path to take an argument

We have long allowed users to run e.g.
    git log --ancestry-path master..seen
which shows all commits which satisfy all three of these criteria:
  * are an ancestor of seen
  * are not an ancestor of master
  * have master as an ancestor

This commit allows another variant:
    git log --ancestry-path=$TOPIC master..seen
which shows all commits which satisfy all of these criteria:
  * are an ancestor of seen
  * are not an ancestor of master
  * have $TOPIC in their ancestry-path
that last bullet can be defined as commits meeting any of these
criteria:
    * are an ancestor of $TOPIC
    * have $TOPIC as an ancestor
    * are $TOPIC

This also allows multiple --ancestry-path arguments, which can be
used to find commits with any of the given topics in their ancestry
path.

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Elijah Newren 2022-08-19 04:28:10 +00:00 committed by Junio C Hamano
parent 1838e21cff
commit 257418c590
5 changed files with 115 additions and 43 deletions

View File

@ -389,12 +389,14 @@ Default mode::
merges from the resulting history, as there are no selected
commits contributing to this merge.
--ancestry-path::
--ancestry-path[=<commit>]::
When given a range of commits to display (e.g. 'commit1..commit2'
or 'commit2 {caret}commit1'), only display commits that exist
directly on the ancestry chain between the 'commit1' and
'commit2', i.e. commits that are both descendants of 'commit1',
and ancestors of 'commit2'.
or 'commit2 {caret}commit1'), only display commits in that range
that are ancestors of <commit>, descendants of <commit>, or
<commit> itself. If no commit is specified, use 'commit1' (the
excluded part of the range) as <commit>. Can be passed multiple
times; if so, a commit is included if it is any of the commits
given or if it is an ancestor or descendant of one of them.
A more detailed explanation follows.
@ -568,11 +570,10 @@ Note the major differences in `N`, `P`, and `Q` over `--full-history`:
There is another simplification mode available:
--ancestry-path::
Limit the displayed commits to those directly on the ancestry
chain between the ``from'' and ``to'' commits in the given commit
range. I.e. only display commits that are ancestor of the ``to''
commit and descendants of the ``from'' commit.
--ancestry-path[=<commit>]::
Limit the displayed commits to those which are an ancestor of
<commit>, or which are a descendant of <commit>, or are <commit>
itself.
+
As an example use case, consider the following commit history:
+
@ -604,6 +605,29 @@ option does. Applied to the 'D..M' range, it results in:
\
L--M
-----------------------------------------------------------------------
+
We can also use `--ancestry-path=D` instead of `--ancestry-path` which
means the same thing when applied to the 'D..M' range but is just more
explicit.
+
If we instead are interested in a given topic within this range, and all
commits affected by that topic, we may only want to view the subset of
`D..M` which contain that topic in their ancestry path. So, using
`--ancestry-path=H D..M` for example would result in:
+
-----------------------------------------------------------------------
E
\
G---H---I---J
\
L--M
-----------------------------------------------------------------------
+
Whereas `--ancestry-path=K D..M` would result in
+
-----------------------------------------------------------------------
K---------------L--M
-----------------------------------------------------------------------
Before discussing another option, `--show-pulls`, we need to
create a new example history.

View File

@ -59,7 +59,7 @@ struct object_array {
/*
* object flag allocation:
* revision.h: 0---------10 15 23------26
* revision.h: 0---------10 15 23------27
* fetch-pack.c: 01 67
* negotiator/default.c: 2--5
* walker.c: 0-2

View File

@ -1105,7 +1105,7 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
struct commit_list **list, struct prio_queue *queue)
{
struct commit_list *parent = commit->parents;
unsigned left_flag;
unsigned pass_flags;
if (commit->object.flags & ADDED)
return 0;
@ -1160,7 +1160,7 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
if (revs->no_walk)
return 0;
left_flag = (commit->object.flags & SYMMETRIC_LEFT);
pass_flags = (commit->object.flags & (SYMMETRIC_LEFT | ANCESTRY_PATH));
for (parent = commit->parents; parent; parent = parent->next) {
struct commit *p = parent->item;
@ -1181,7 +1181,7 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
if (!*slot)
*slot = *revision_sources_at(revs->sources, commit);
}
p->object.flags |= left_flag;
p->object.flags |= pass_flags;
if (!(p->object.flags & SEEN)) {
p->object.flags |= (SEEN | NOT_USER_GIVEN);
if (list)
@ -1304,13 +1304,24 @@ static int still_interesting(struct commit_list *src, timestamp_t date, int slop
}
/*
* "rev-list --ancestry-path A..B" computes commits that are ancestors
* of B but not ancestors of A but further limits the result to those
* that are descendants of A. This takes the list of bottom commits and
* the result of "A..B" without --ancestry-path, and limits the latter
* further to the ones that can reach one of the commits in "bottom".
* "rev-list --ancestry-path=C_0 [--ancestry-path=C_1 ...] A..B"
* computes commits that are ancestors of B but not ancestors of A but
* further limits the result to those that have any of C in their
* ancestry path (i.e. are either ancestors of any of C, descendants
* of any of C, or are any of C). If --ancestry-path is specified with
* no commit, we use all bottom commits for C.
*
* Before this function is called, ancestors of C will have already
* been marked with ANCESTRY_PATH previously.
*
* This takes the list of bottom commits and the result of "A..B"
* without --ancestry-path, and limits the latter further to the ones
* that have any of C in their ancestry path. Since the ancestors of C
* have already been marked (a prerequisite of this function), we just
* need to mark the descendants, then exclude any commit that does not
* have any of these marks.
*/
static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
static void limit_to_ancestry(struct commit_list *bottoms, struct commit_list *list)
{
struct commit_list *p;
struct commit_list *rlist = NULL;
@ -1323,7 +1334,7 @@ static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *li
for (p = list; p; p = p->next)
commit_list_insert(p->item, &rlist);
for (p = bottom; p; p = p->next)
for (p = bottoms; p; p = p->next)
p->item->object.flags |= TMP_MARK;
/*
@ -1356,38 +1367,39 @@ static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *li
*/
/*
* The ones that are not marked with TMP_MARK are uninteresting
* The ones that are not marked with either TMP_MARK or
* ANCESTRY_PATH are uninteresting
*/
for (p = list; p; p = p->next) {
struct commit *c = p->item;
if (c->object.flags & TMP_MARK)
if (c->object.flags & (TMP_MARK | ANCESTRY_PATH))
continue;
c->object.flags |= UNINTERESTING;
}
/* We are done with the TMP_MARK */
/* We are done with TMP_MARK and ANCESTRY_PATH */
for (p = list; p; p = p->next)
p->item->object.flags &= ~TMP_MARK;
for (p = bottom; p; p = p->next)
p->item->object.flags &= ~TMP_MARK;
p->item->object.flags &= ~(TMP_MARK | ANCESTRY_PATH);
for (p = bottoms; p; p = p->next)
p->item->object.flags &= ~(TMP_MARK | ANCESTRY_PATH);
free_commit_list(rlist);
}
/*
* Before walking the history, keep the set of "negative" refs the
* caller has asked to exclude.
* Before walking the history, add the set of "negative" refs the
* caller has asked to exclude to the bottom list.
*
* This is used to compute "rev-list --ancestry-path A..B", as we need
* to filter the result of "A..B" further to the ones that can actually
* reach A.
*/
static struct commit_list *collect_bottom_commits(struct commit_list *list)
static void collect_bottom_commits(struct commit_list *list,
struct commit_list **bottom)
{
struct commit_list *elem, *bottom = NULL;
struct commit_list *elem;
for (elem = list; elem; elem = elem->next)
if (elem->item->object.flags & BOTTOM)
commit_list_insert(elem->item, &bottom);
return bottom;
commit_list_insert(elem->item, bottom);
}
/* Assumes either left_only or right_only is set */
@ -1414,12 +1426,12 @@ static int limit_list(struct rev_info *revs)
struct commit_list *original_list = revs->commits;
struct commit_list *newlist = NULL;
struct commit_list **p = &newlist;
struct commit_list *bottom = NULL;
struct commit *interesting_cache = NULL;
if (revs->ancestry_path) {
bottom = collect_bottom_commits(original_list);
if (!bottom)
if (revs->ancestry_path_implicit_bottoms) {
collect_bottom_commits(original_list,
&revs->ancestry_path_bottoms);
if (!revs->ancestry_path_bottoms)
die("--ancestry-path given but there are no bottom commits");
}
@ -1464,9 +1476,8 @@ static int limit_list(struct rev_info *revs)
if (revs->left_only || revs->right_only)
limit_left_right(newlist, revs);
if (bottom)
limit_to_ancestry(bottom, newlist);
free_commit_list(bottom);
if (revs->ancestry_path)
limit_to_ancestry(revs->ancestry_path_bottoms, newlist);
/*
* Check if any commits have become TREESAME by some of their parents
@ -2213,7 +2224,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
const struct setup_revision_opt* opt)
{
const char *arg = argv[0];
const char *optarg;
const char *optarg = NULL;
int argcount;
const unsigned hexsz = the_hash_algo->hexsz;
@ -2284,6 +2295,23 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
revs->ancestry_path = 1;
revs->simplify_history = 0;
revs->limited = 1;
revs->ancestry_path_implicit_bottoms = 1;
} else if (skip_prefix(arg, "--ancestry-path=", &optarg)) {
struct commit *c;
struct object_id oid;
const char *msg = _("could not get commit for ancestry-path argument %s");
revs->ancestry_path = 1;
revs->simplify_history = 0;
revs->limited = 1;
if (repo_get_oid_committish(revs->repo, optarg, &oid))
return error(msg, optarg);
get_reference(revs, optarg, &oid, ANCESTRY_PATH);
c = lookup_commit_reference(revs->repo, &oid);
if (!c)
return error(msg, optarg);
commit_list_insert(c, &revs->ancestry_path_bottoms);
} else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
init_reflog_walk(&revs->reflog_info);
} else if (!strcmp(arg, "--default")) {
@ -2993,6 +3021,7 @@ static void release_revisions_topo_walk_info(struct topo_walk_info *info);
void release_revisions(struct rev_info *revs)
{
free_commit_list(revs->commits);
free_commit_list(revs->ancestry_path_bottoms);
object_array_clear(&revs->pending);
object_array_clear(&revs->boundary_commits);
release_revisions_cmdline(&revs->cmdline);

View File

@ -48,6 +48,7 @@
*/
#define NOT_USER_GIVEN (1u<<25)
#define TRACK_LINEAR (1u<<26)
#define ANCESTRY_PATH (1u<<27)
#define ALL_REV_FLAGS (((1u<<11)-1) | NOT_USER_GIVEN | TRACK_LINEAR | PULL_MERGE)
#define DECORATE_SHORT_REFS 1
@ -164,6 +165,13 @@ struct rev_info {
cherry_mark:1,
bisect:1,
ancestry_path:1,
/* True if --ancestry-path was specified without an
* argument. The bottom revisions are implicitly
* the arguments in this case.
*/
ancestry_path_implicit_bottoms:1,
first_parent_only:1,
exclude_first_parent_only:1,
line_level_traverse:1,
@ -306,6 +314,7 @@ struct rev_info {
struct saved_parents *saved_parents_slab;
struct commit_list *previous_parents;
struct commit_list *ancestry_path_bottoms;
const char *break_bar;
struct revision_sources *sources;

View File

@ -8,8 +8,13 @@ test_description='--ancestry-path'
# / \
# A-------K---------------L--M
#
# D..M == E F G H I J K L M
# --ancestry-path D..M == E F H I J L M
# D..M == E F G H I J K L M
# --ancestry-path D..M == E F H I J L M
# --ancestry-path=F D..M == E F J L M
# --ancestry-path=G D..M == G H I J L M
# --ancestry-path=H D..M == E G H I J L M
# --ancestry-path=K D..M == K L M
# --ancestry-path=K --ancestry-path=F D..M == E F J K L M
#
# D..M -- M.t == M
# --ancestry-path D..M -- M.t == M
@ -70,6 +75,11 @@ test_ancestry () {
test_ancestry "D..M" "E F G H I J K L M"
test_ancestry "--ancestry-path D..M" "E F H I J L M"
test_ancestry "--ancestry-path=F D..M" "E F J L M"
test_ancestry "--ancestry-path=G D..M" "G H I J L M"
test_ancestry "--ancestry-path=H D..M" "E G H I J L M"
test_ancestry "--ancestry-path=K D..M" "K L M"
test_ancestry "--ancestry-path=F --ancestry-path=K D..M" "E F J K L M"
test_ancestry "D..M -- M.t" "M"
test_ancestry "--ancestry-path D..M -- M.t" "M"