docs: explain why squash merges are broken with long-running branches
[git] / commit-reach.h
1 #ifndef COMMIT_REACH_H
2 #define COMMIT_REACH_H
3
4 #include "commit.h"
5 #include "commit-slab.h"
6
7 struct commit_list;
8 struct ref_filter;
9 struct object_id;
10 struct object_array;
11
12 struct commit_list *repo_get_merge_bases(struct repository *r,
13                                          struct commit *rev1,
14                                          struct commit *rev2);
15 struct commit_list *repo_get_merge_bases_many(struct repository *r,
16                                               struct commit *one, int n,
17                                               struct commit **twos);
18 /* To be used only when object flags after this call no longer matter */
19 struct commit_list *repo_get_merge_bases_many_dirty(struct repository *r,
20                                                     struct commit *one, int n,
21                                                     struct commit **twos);
22 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
23 #define get_merge_bases(r1, r2)           repo_get_merge_bases(the_repository, r1, r2)
24 #define get_merge_bases_many(one, n, two) repo_get_merge_bases_many(the_repository, one, n, two)
25 #define get_merge_bases_many_dirty(one, n, twos) repo_get_merge_bases_many_dirty(the_repository, one, n, twos)
26 #endif
27
28 struct commit_list *get_octopus_merge_bases(struct commit_list *in);
29
30 int repo_is_descendant_of(struct repository *r,
31                           struct commit *commit,
32                           struct commit_list *with_commit);
33 int repo_in_merge_bases(struct repository *r,
34                         struct commit *commit,
35                         struct commit *reference);
36 int repo_in_merge_bases_many(struct repository *r,
37                              struct commit *commit,
38                              int nr_reference, struct commit **reference);
39 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
40 #define in_merge_bases(c1, c2) repo_in_merge_bases(the_repository, c1, c2)
41 #define in_merge_bases_many(c1, n, cs) repo_in_merge_bases_many(the_repository, c1, n, cs)
42 #endif
43
44 /*
45  * Takes a list of commits and returns a new list where those
46  * have been removed that can be reached from other commits in
47  * the list. It is useful for, e.g., reducing the commits
48  * randomly thrown at the git-merge command and removing
49  * redundant commits that the user shouldn't have given to it.
50  *
51  * This function destroys the STALE bit of the commit objects'
52  * flags.
53  */
54 struct commit_list *reduce_heads(struct commit_list *heads);
55
56 /*
57  * Like `reduce_heads()`, except it replaces the list. Use this
58  * instead of `foo = reduce_heads(foo);` to avoid memory leaks.
59  */
60 void reduce_heads_replace(struct commit_list **heads);
61
62 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
63
64 /*
65  * Unknown has to be "0" here, because that's the default value for
66  * contains_cache slab entries that have not yet been assigned.
67  */
68 enum contains_result {
69         CONTAINS_UNKNOWN = 0,
70         CONTAINS_NO,
71         CONTAINS_YES
72 };
73
74 define_commit_slab(contains_cache, enum contains_result);
75
76 int commit_contains(struct ref_filter *filter, struct commit *commit,
77                     struct commit_list *list, struct contains_cache *cache);
78
79 /*
80  * Determine if every commit in 'from' can reach at least one commit
81  * that is marked with 'with_flag'. As we traverse, use 'assign_flag'
82  * as a marker for commits that are already visited. Do not walk
83  * commits with date below 'min_commit_date' or generation below
84  * 'min_generation'.
85  */
86 int can_all_from_reach_with_flag(struct object_array *from,
87                                  unsigned int with_flag,
88                                  unsigned int assign_flag,
89                                  time_t min_commit_date,
90                                  uint32_t min_generation);
91 int can_all_from_reach(struct commit_list *from, struct commit_list *to,
92                        int commit_date_cutoff);
93
94
95 /*
96  * Return a list of commits containing the commits in the 'to' array
97  * that are reachable from at least one commit in the 'from' array.
98  * Also add the given 'flag' to each of the commits in the returned list.
99  *
100  * This method uses the PARENT1 and PARENT2 flags during its operation,
101  * so be sure these flags are not set before calling the method.
102  */
103 struct commit_list *get_reachable_subset(struct commit **from, int nr_from,
104                                          struct commit **to, int nr_to,
105                                          unsigned int reachable_flag);
106
107 #endif