diff options
Diffstat (limited to 'revision.c')
| -rw-r--r-- | revision.c | 202 |
1 files changed, 181 insertions, 21 deletions
diff --git a/revision.c b/revision.c index 36291b6b86..bcbc7bd7e4 100644 --- a/revision.c +++ b/revision.c @@ -489,7 +489,7 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit, p->object.flags |= SEEN; insert_by_date_cached(p, list, cached_base, cache_ptr); } - if(revs->first_parent_only) + if (revs->first_parent_only) break; } return 0; @@ -1041,6 +1041,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg } else if (!strcmp(arg, "--topo-order")) { revs->lifo = 1; revs->topo_order = 1; + } else if (!strcmp(arg, "--simplify-merges")) { + revs->simplify_merges = 1; + revs->rewrite_parents = 1; + revs->simplify_history = 0; + revs->limited = 1; } else if (!strcmp(arg, "--date-order")) { revs->lifo = 0; revs->topo_order = 1; @@ -1368,6 +1373,179 @@ 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) +{ + struct commit_list **pp, *p; + int surviving_parents; + + /* Examine existing parents while marking ones we have seen... */ + pp = &commit->parents; + while ((p = *pp) != NULL) { + struct commit *parent = p->item; + if (parent->object.flags & TMP_MARK) { + *pp = p->next; + continue; + } + parent->object.flags |= TMP_MARK; + pp = &p->next; + } + /* count them while clearing the temporary mark */ + surviving_parents = 0; + for (p = commit->parents; p; p = p->next) { + p->item->object.flags &= ~TMP_MARK; + surviving_parents++; + } + return surviving_parents; +} + +struct merge_simplify_state { + struct commit *simplified; +}; + +static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit) +{ + struct merge_simplify_state *st; + + st = lookup_decoration(&revs->merge_simplification, &commit->object); + if (!st) { + st = xcalloc(1, sizeof(*st)); + add_decoration(&revs->merge_simplification, &commit->object, st); + } + return st; +} + +static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail) +{ + struct commit_list *p; + struct merge_simplify_state *st, *pst; + int cnt; + + st = locate_simplify_state(revs, commit); + + /* + * Have we handled this one? + */ + if (st->simplified) + return tail; + + /* + * An UNINTERESTING commit simplifies to itself, so does a + * root commit. We do not rewrite parents of such commit + * anyway. + */ + if ((commit->object.flags & UNINTERESTING) || !commit->parents) { + st->simplified = commit; + return tail; + } + + /* + * Do we know what commit all of our parents should be rewritten to? + * Otherwise we are not ready to rewrite this one yet. + */ + for (cnt = 0, p = commit->parents; p; p = p->next) { + pst = locate_simplify_state(revs, p->item); + if (!pst->simplified) { + tail = &commit_list_insert(p->item, tail)->next; + cnt++; + } + } + if (cnt) { + tail = &commit_list_insert(commit, tail)->next; + return tail; + } + + /* + * Rewrite our list of parents. + */ + for (p = commit->parents; p; p = p->next) { + pst = locate_simplify_state(revs, p->item); + p->item = pst->simplified; + } + cnt = remove_duplicate_parents(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. + * + * 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. + */ + if (1 < cnt) { + struct commit_list *h = reduce_heads(commit->parents); + cnt = commit_list_count(h); + free_commit_list(commit->parents); + commit->parents = h; + } + + /* + * 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 + * (the first two cases are already handled at the beginning of + * this function). + * + * Otherwise, it simplifies to what its sole parent simplifies to. + */ + if (!cnt || + (commit->object.flags & UNINTERESTING) || + !(commit->object.flags & TREESAME) || + (1 < cnt)) + st->simplified = commit; + else { + pst = locate_simplify_state(revs, commit->parents->item); + st->simplified = pst->simplified; + } + return tail; +} + +static void simplify_merges(struct rev_info *revs) +{ + struct commit_list *list; + struct commit_list *yet_to_do, **tail; + + if (!revs->topo_order) + sort_in_topological_order(&revs->commits, revs->lifo); + if (!revs->prune) + return; + + /* feed the list reversed */ + yet_to_do = NULL; + for (list = revs->commits; list; list = list->next) + commit_list_insert(list->item, &yet_to_do); + while (yet_to_do) { + list = yet_to_do; + yet_to_do = NULL; + tail = &yet_to_do; + while (list) { + struct commit *commit = list->item; + struct commit_list *next = list->next; + free(list); + list = next; + tail = simplify_one(revs, commit, tail); + } + } + + /* clean up the result, removing the simplified ones */ + list = revs->commits; + revs->commits = NULL; + tail = &revs->commits; + while (list) { + struct commit *commit = list->item; + struct commit_list *next = list->next; + struct merge_simplify_state *st; + free(list); + list = next; + st = locate_simplify_state(revs, commit); + if (st->simplified == commit) + tail = &commit_list_insert(commit, tail)->next; + } +} + static void set_children(struct rev_info *revs) { struct commit_list *l; @@ -1408,6 +1586,8 @@ int prepare_revision_walk(struct rev_info *revs) return -1; if (revs->topo_order) sort_in_topological_order(&revs->commits, revs->lifo); + if (revs->simplify_merges) + simplify_merges(revs); if (revs->children.name) set_children(revs); return 0; @@ -1440,26 +1620,6 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp } } -static void remove_duplicate_parents(struct commit *commit) -{ - struct commit_list **pp, *p; - - /* Examine existing parents while marking ones we have seen... */ - pp = &commit->parents; - while ((p = *pp) != NULL) { - struct commit *parent = p->item; - if (parent->object.flags & TMP_MARK) { - *pp = p->next; - continue; - } - parent->object.flags |= TMP_MARK; - pp = &p->next; - } - /* ... and clear the temporary mark */ - for (p = commit->parents; p; p = p->next) - p->item->object.flags &= ~TMP_MARK; -} - static int rewrite_parents(struct rev_info *revs, struct commit *commit) { struct commit_list **pp = &commit->parents; |