diff options
Diffstat (limited to 'unpack-trees.c')
| -rw-r--r-- | unpack-trees.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/unpack-trees.c b/unpack-trees.c index 20251822e4..a20639be70 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -3,8 +3,11 @@ #include "cache.h" #include "tree.h" #include "tree-walk.h" +#include "cache-tree.h" #include "unpack-trees.h" +#define DBRT_DEBUG 1 + struct tree_entry_list { struct tree_entry_list *next; unsigned directory : 1; @@ -22,6 +25,9 @@ static struct tree_entry_list *create_tree_entry_list(struct tree *tree) struct tree_entry_list *ret = NULL; struct tree_entry_list **list_p = &ret; + if (!tree->object.parsed) + parse_tree(tree); + desc.buf = tree->buffer; desc.size = tree->size; @@ -368,12 +374,14 @@ int unpack_trees(struct object_list *trees, struct unpack_trees_options *o) memset(&df_conflict_list, 0, sizeof(df_conflict_list)); df_conflict_list.next = &df_conflict_list; + memset(&state, 0, sizeof(state)); state.base_dir = ""; state.force = 1; state.quiet = 1; state.refresh_cache = 1; o->merge_size = len; + memset(&df_conflict_entry, 0, sizeof(df_conflict_entry)); o->df_conflict_entry = &df_conflict_entry; if (len) { @@ -393,3 +401,399 @@ int unpack_trees(struct object_list *trees, struct unpack_trees_options *o) check_updates(active_cache, active_nr, o); return 0; } + +/* Here come the merge functions */ + +static void reject_merge(struct cache_entry *ce) +{ + die("Entry '%s' would be overwritten by merge. Cannot merge.", + ce->name); +} + +static int same(struct cache_entry *a, struct cache_entry *b) +{ + if (!!a != !!b) + return 0; + if (!a && !b) + return 1; + return a->ce_mode == b->ce_mode && + !memcmp(a->sha1, b->sha1, 20); +} + + +/* + * When a CE gets turned into an unmerged entry, we + * want it to be up-to-date + */ +static void verify_uptodate(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct stat st; + + if (o->index_only || o->reset) + return; + + if (!lstat(ce->name, &st)) { + unsigned changed = ce_match_stat(ce, &st, 1); + if (!changed) + return; + errno = 0; + } + if (o->reset) { + ce->ce_flags |= htons(CE_UPDATE); + return; + } + if (errno == ENOENT) + return; + die("Entry '%s' not uptodate. Cannot merge.", ce->name); +} + +static void invalidate_ce_path(struct cache_entry *ce) +{ + if (ce) + cache_tree_invalidate_path(active_cache_tree, ce->name); +} + +/* + * We do not want to remove or overwrite a working tree file that + * is not tracked. + */ +static void verify_absent(const char *path, const char *action, + struct unpack_trees_options *o) +{ + struct stat st; + + if (o->index_only || o->reset || !o->update) + return; + if (!lstat(path, &st)) + die("Untracked working tree file '%s' " + "would be %s by merge.", path, action); +} + +static int merged_entry(struct cache_entry *merge, struct cache_entry *old, + struct unpack_trees_options *o) +{ + merge->ce_flags |= htons(CE_UPDATE); + if (old) { + /* + * See if we can re-use the old CE directly? + * That way we get the uptodate stat info. + * + * This also removes the UPDATE flag on + * a match. + */ + if (same(old, merge)) { + *merge = *old; + } else { + verify_uptodate(old, o); + invalidate_ce_path(old); + } + } + else { + verify_absent(merge->name, "overwritten", o); + invalidate_ce_path(merge); + } + + merge->ce_flags &= ~htons(CE_STAGEMASK); + add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); + return 1; +} + +static int deleted_entry(struct cache_entry *ce, struct cache_entry *old, + struct unpack_trees_options *o) +{ + if (old) + verify_uptodate(old, o); + else + verify_absent(ce->name, "removed", o); + ce->ce_mode = 0; + add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); + invalidate_ce_path(ce); + return 1; +} + +static int keep_entry(struct cache_entry *ce) +{ + add_cache_entry(ce, ADD_CACHE_OK_TO_ADD); + return 1; +} + +#if DBRT_DEBUG +static void show_stage_entry(FILE *o, + const char *label, const struct cache_entry *ce) +{ + if (!ce) + fprintf(o, "%s (missing)\n", label); + else + fprintf(o, "%s%06o %s %d\t%s\n", + label, + ntohl(ce->ce_mode), + sha1_to_hex(ce->sha1), + ce_stage(ce), + ce->name); +} +#endif + +int threeway_merge(struct cache_entry **stages, + struct unpack_trees_options *o) +{ + struct cache_entry *index; + struct cache_entry *head; + struct cache_entry *remote = stages[o->head_idx + 1]; + int count; + int head_match = 0; + int remote_match = 0; + const char *path = NULL; + + int df_conflict_head = 0; + int df_conflict_remote = 0; + + int any_anc_missing = 0; + int no_anc_exists = 1; + int i; + + for (i = 1; i < o->head_idx; i++) { + if (!stages[i]) + any_anc_missing = 1; + else { + if (!path) + path = stages[i]->name; + no_anc_exists = 0; + } + } + + index = stages[0]; + head = stages[o->head_idx]; + + if (head == o->df_conflict_entry) { + df_conflict_head = 1; + head = NULL; + } + + if (remote == o->df_conflict_entry) { + df_conflict_remote = 1; + remote = NULL; + } + + if (!path && index) + path = index->name; + if (!path && head) + path = head->name; + if (!path && remote) + path = remote->name; + + /* First, if there's a #16 situation, note that to prevent #13 + * and #14. + */ + if (!same(remote, head)) { + for (i = 1; i < o->head_idx; i++) { + if (same(stages[i], head)) { + head_match = i; + } + if (same(stages[i], remote)) { + remote_match = i; + } + } + } + + /* We start with cases where the index is allowed to match + * something other than the head: #14(ALT) and #2ALT, where it + * is permitted to match the result instead. + */ + /* #14, #14ALT, #2ALT */ + if (remote && !df_conflict_head && head_match && !remote_match) { + if (index && !same(index, remote) && !same(index, head)) + reject_merge(index); + return merged_entry(remote, index, o); + } + /* + * If we have an entry in the index cache, then we want to + * make sure that it matches head. + */ + if (index && !same(index, head)) { + reject_merge(index); + } + + if (head) { + /* #5ALT, #15 */ + if (same(head, remote)) + return merged_entry(head, index, o); + /* #13, #3ALT */ + if (!df_conflict_remote && remote_match && !head_match) + return merged_entry(head, index, o); + } + + /* #1 */ + if (!head && !remote && any_anc_missing) + return 0; + + /* Under the new "aggressive" rule, we resolve mostly trivial + * cases that we historically had git-merge-one-file resolve. + */ + if (o->aggressive) { + int head_deleted = !head && !df_conflict_head; + int remote_deleted = !remote && !df_conflict_remote; + /* + * Deleted in both. + * Deleted in one and unchanged in the other. + */ + if ((head_deleted && remote_deleted) || + (head_deleted && remote && remote_match) || + (remote_deleted && head && head_match)) { + if (index) + return deleted_entry(index, index, o); + else if (path) + verify_absent(path, "removed", o); + return 0; + } + /* + * Added in both, identically. + */ + if (no_anc_exists && head && remote && same(head, remote)) + return merged_entry(head, index, o); + + } + + /* Below are "no merge" cases, which require that the index be + * up-to-date to avoid the files getting overwritten with + * conflict resolution files. + */ + if (index) { + verify_uptodate(index, o); + } + else if (path) + verify_absent(path, "overwritten", o); + + o->nontrivial_merge = 1; + + /* #2, #3, #4, #6, #7, #9, #11. */ + count = 0; + if (!head_match || !remote_match) { + for (i = 1; i < o->head_idx; i++) { + if (stages[i]) { + keep_entry(stages[i]); + count++; + break; + } + } + } +#if DBRT_DEBUG + else { + fprintf(stderr, "read-tree: warning #16 detected\n"); + show_stage_entry(stderr, "head ", stages[head_match]); + show_stage_entry(stderr, "remote ", stages[remote_match]); + } +#endif + if (head) { count += keep_entry(head); } + if (remote) { count += keep_entry(remote); } + return count; +} + +/* + * Two-way merge. + * + * The rule is to "carry forward" what is in the index without losing + * information across a "fast forward", favoring a successful merge + * over a merge failure when it makes sense. For details of the + * "carry forward" rule, please see <Documentation/git-read-tree.txt>. + * + */ +int twoway_merge(struct cache_entry **src, + struct unpack_trees_options *o) +{ + struct cache_entry *current = src[0]; + struct cache_entry *oldtree = src[1], *newtree = src[2]; + + if (o->merge_size != 2) + return error("Cannot do a twoway merge of %d trees", + o->merge_size); + + if (current) { + if ((!oldtree && !newtree) || /* 4 and 5 */ + (!oldtree && newtree && + same(current, newtree)) || /* 6 and 7 */ + (oldtree && newtree && + same(oldtree, newtree)) || /* 14 and 15 */ + (oldtree && newtree && + !same(oldtree, newtree) && /* 18 and 19*/ + same(current, newtree))) { + return keep_entry(current); + } + else if (oldtree && !newtree && same(current, oldtree)) { + /* 10 or 11 */ + return deleted_entry(oldtree, current, o); + } + else if (oldtree && newtree && + same(current, oldtree) && !same(current, newtree)) { + /* 20 or 21 */ + return merged_entry(newtree, current, o); + } + else { + /* all other failures */ + if (oldtree) + reject_merge(oldtree); + if (current) + reject_merge(current); + if (newtree) + reject_merge(newtree); + return -1; + } + } + else if (newtree) + return merged_entry(newtree, current, o); + else + return deleted_entry(oldtree, current, o); +} + +/* + * Bind merge. + * + * Keep the index entries at stage0, collapse stage1 but make sure + * stage0 does not have anything there. + */ +int bind_merge(struct cache_entry **src, + struct unpack_trees_options *o) +{ + struct cache_entry *old = src[0]; + struct cache_entry *a = src[1]; + + if (o->merge_size != 1) + return error("Cannot do a bind merge of %d trees\n", + o->merge_size); + if (a && old) + die("Entry '%s' overlaps. Cannot bind.", a->name); + if (!a) + return keep_entry(old); + else + return merged_entry(a, NULL, o); +} + +/* + * One-way merge. + * + * The rule is: + * - take the stat information from stage0, take the data from stage1 + */ +int oneway_merge(struct cache_entry **src, + struct unpack_trees_options *o) +{ + struct cache_entry *old = src[0]; + struct cache_entry *a = src[1]; + + if (o->merge_size != 1) + return error("Cannot do a oneway merge of %d trees", + o->merge_size); + + if (!a) + return deleted_entry(old, old, o); + if (old && same(old, a)) { + if (o->reset) { + struct stat st; + if (lstat(old->name, &st) || + ce_match_stat(old, &st, 1)) + old->ce_flags |= htons(CE_UPDATE); + } + return keep_entry(old); + } + return merged_entry(a, old, o); +} |