| #include "builtin.h" |
| #include "tree-walk.h" |
| #include "xdiff-interface.h" |
| #include "blob.h" |
| #include "exec_cmd.h" |
| #include "merge-blobs.h" |
| |
| static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>"; |
| |
| struct merge_list { |
| struct merge_list *next; |
| struct merge_list *link; /* other stages for this object */ |
| |
| unsigned int stage : 2; |
| unsigned int mode; |
| const char *path; |
| struct blob *blob; |
| }; |
| |
| static struct merge_list *merge_result, **merge_result_end = &merge_result; |
| |
| static void add_merge_entry(struct merge_list *entry) |
| { |
| *merge_result_end = entry; |
| merge_result_end = &entry->next; |
| } |
| |
| static void merge_trees(struct tree_desc t[3], const char *base); |
| |
| static const char *explanation(struct merge_list *entry) |
| { |
| switch (entry->stage) { |
| case 0: |
| return "merged"; |
| case 3: |
| return "added in remote"; |
| case 2: |
| if (entry->link) |
| return "added in both"; |
| return "added in local"; |
| } |
| |
| /* Existed in base */ |
| entry = entry->link; |
| if (!entry) |
| return "removed in both"; |
| |
| if (entry->link) |
| return "changed in both"; |
| |
| if (entry->stage == 3) |
| return "removed in local"; |
| return "removed in remote"; |
| } |
| |
| static void *result(struct merge_list *entry, unsigned long *size) |
| { |
| enum object_type type; |
| struct blob *base, *our, *their; |
| const char *path = entry->path; |
| |
| if (!entry->stage) |
| return read_sha1_file(entry->blob->object.sha1, &type, size); |
| base = NULL; |
| if (entry->stage == 1) { |
| base = entry->blob; |
| entry = entry->link; |
| } |
| our = NULL; |
| if (entry && entry->stage == 2) { |
| our = entry->blob; |
| entry = entry->link; |
| } |
| their = NULL; |
| if (entry) |
| their = entry->blob; |
| return merge_blobs(path, base, our, their, size); |
| } |
| |
| static void *origin(struct merge_list *entry, unsigned long *size) |
| { |
| enum object_type type; |
| while (entry) { |
| if (entry->stage == 2) |
| return read_sha1_file(entry->blob->object.sha1, &type, size); |
| entry = entry->link; |
| } |
| return NULL; |
| } |
| |
| static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf) |
| { |
| int i; |
| for (i = 0; i < nbuf; i++) |
| printf("%.*s", (int) mb[i].size, mb[i].ptr); |
| return 0; |
| } |
| |
| static void show_diff(struct merge_list *entry) |
| { |
| unsigned long size; |
| mmfile_t src, dst; |
| xpparam_t xpp; |
| xdemitconf_t xecfg; |
| xdemitcb_t ecb; |
| |
| xpp.flags = 0; |
| memset(&xecfg, 0, sizeof(xecfg)); |
| xecfg.ctxlen = 3; |
| ecb.outf = show_outf; |
| ecb.priv = NULL; |
| |
| src.ptr = origin(entry, &size); |
| if (!src.ptr) |
| size = 0; |
| src.size = size; |
| dst.ptr = result(entry, &size); |
| if (!dst.ptr) |
| size = 0; |
| dst.size = size; |
| xdi_diff(&src, &dst, &xpp, &xecfg, &ecb); |
| free(src.ptr); |
| free(dst.ptr); |
| } |
| |
| static void show_result_list(struct merge_list *entry) |
| { |
| printf("%s\n", explanation(entry)); |
| do { |
| struct merge_list *link = entry->link; |
| static const char *desc[4] = { "result", "base", "our", "their" }; |
| printf(" %-6s %o %s %s\n", desc[entry->stage], entry->mode, sha1_to_hex(entry->blob->object.sha1), entry->path); |
| entry = link; |
| } while (entry); |
| } |
| |
| static void show_result(void) |
| { |
| struct merge_list *walk; |
| |
| walk = merge_result; |
| while (walk) { |
| show_result_list(walk); |
| show_diff(walk); |
| walk = walk->next; |
| } |
| } |
| |
| /* An empty entry never compares same, not even to another empty entry */ |
| static int same_entry(struct name_entry *a, struct name_entry *b) |
| { |
| return a->sha1 && |
| b->sha1 && |
| !hashcmp(a->sha1, b->sha1) && |
| a->mode == b->mode; |
| } |
| |
| static int both_empty(struct name_entry *a, struct name_entry *b) |
| { |
| return !(a->sha1 || b->sha1); |
| } |
| |
| static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path) |
| { |
| struct merge_list *res = xcalloc(1, sizeof(*res)); |
| |
| res->stage = stage; |
| res->path = path; |
| res->mode = mode; |
| res->blob = lookup_blob(sha1); |
| return res; |
| } |
| |
| static char *traverse_path(const struct traverse_info *info, const struct name_entry *n) |
| { |
| char *path = xmalloc(traverse_path_len(info, n) + 1); |
| return make_traverse_path(path, info, n); |
| } |
| |
| static void resolve(const struct traverse_info *info, struct name_entry *ours, struct name_entry *result) |
| { |
| struct merge_list *orig, *final; |
| const char *path; |
| |
| /* If it's already ours, don't bother showing it */ |
| if (!ours) |
| return; |
| |
| path = traverse_path(info, result); |
| orig = create_entry(2, ours->mode, ours->sha1, path); |
| final = create_entry(0, result->mode, result->sha1, path); |
| |
| final->link = orig; |
| |
| add_merge_entry(final); |
| } |
| |
| static void unresolved_directory(const struct traverse_info *info, |
| struct name_entry n[3]) |
| { |
| char *newbase; |
| struct name_entry *p; |
| struct tree_desc t[3]; |
| void *buf0, *buf1, *buf2; |
| |
| for (p = n; p < n + 3; p++) { |
| if (p->mode && S_ISDIR(p->mode)) |
| break; |
| } |
| if (n + 3 <= p) |
| return; /* there is no tree here */ |
| |
| newbase = traverse_path(info, p); |
| |
| #define ENTRY_SHA1(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->sha1 : NULL) |
| buf0 = fill_tree_descriptor(t+0, ENTRY_SHA1(n + 0)); |
| buf1 = fill_tree_descriptor(t+1, ENTRY_SHA1(n + 1)); |
| buf2 = fill_tree_descriptor(t+2, ENTRY_SHA1(n + 2)); |
| #undef ENTRY_SHA1 |
| |
| merge_trees(t, newbase); |
| |
| free(buf0); |
| free(buf1); |
| free(buf2); |
| free(newbase); |
| } |
| |
| |
| static struct merge_list *link_entry(unsigned stage, const struct traverse_info *info, struct name_entry *n, struct merge_list *entry) |
| { |
| const char *path; |
| struct merge_list *link; |
| |
| if (!n->mode) |
| return entry; |
| if (entry) |
| path = entry->path; |
| else |
| path = traverse_path(info, n); |
| link = create_entry(stage, n->mode, n->sha1, path); |
| link->link = entry; |
| return link; |
| } |
| |
| static void unresolved(const struct traverse_info *info, struct name_entry n[3]) |
| { |
| struct merge_list *entry = NULL; |
| int i; |
| unsigned dirmask = 0, mask = 0; |
| |
| for (i = 0; i < 3; i++) { |
| mask |= (1 << i); |
| /* |
| * Treat missing entries as directories so that we return |
| * after unresolved_directory has handled this. |
| */ |
| if (!n[i].mode || S_ISDIR(n[i].mode)) |
| dirmask |= (1 << i); |
| } |
| |
| unresolved_directory(info, n); |
| |
| if (dirmask == mask) |
| return; |
| |
| if (n[2].mode && !S_ISDIR(n[2].mode)) |
| entry = link_entry(3, info, n + 2, entry); |
| if (n[1].mode && !S_ISDIR(n[1].mode)) |
| entry = link_entry(2, info, n + 1, entry); |
| if (n[0].mode && !S_ISDIR(n[0].mode)) |
| entry = link_entry(1, info, n + 0, entry); |
| |
| add_merge_entry(entry); |
| } |
| |
| /* |
| * Merge two trees together (t[1] and t[2]), using a common base (t[0]) |
| * as the origin. |
| * |
| * This walks the (sorted) trees in lock-step, checking every possible |
| * name. Note that directories automatically sort differently from other |
| * files (see "base_name_compare"), so you'll never see file/directory |
| * conflicts, because they won't ever compare the same. |
| * |
| * IOW, if a directory changes to a filename, it will automatically be |
| * seen as the directory going away, and the filename being created. |
| * |
| * Think of this as a three-way diff. |
| * |
| * The output will be either: |
| * - successful merge |
| * "0 mode sha1 filename" |
| * NOTE NOTE NOTE! FIXME! We really really need to walk the index |
| * in parallel with this too! |
| * |
| * - conflict: |
| * "1 mode sha1 filename" |
| * "2 mode sha1 filename" |
| * "3 mode sha1 filename" |
| * where not all of the 1/2/3 lines may exist, of course. |
| * |
| * The successful merge rules are the same as for the three-way merge |
| * in git-read-tree. |
| */ |
| static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *info) |
| { |
| /* Same in both? */ |
| if (same_entry(entry+1, entry+2) || both_empty(entry+1, entry+2)) { |
| /* Modified, added or removed identically */ |
| resolve(info, NULL, entry+1); |
| return mask; |
| } |
| |
| if (same_entry(entry+0, entry+1)) { |
| if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) { |
| /* We did not touch, they modified -- take theirs */ |
| resolve(info, entry+1, entry+2); |
| return mask; |
| } |
| /* |
| * If we did not touch a directory but they made it |
| * into a file, we fall through and unresolved() |
| * recurses down. Likewise for the opposite case. |
| */ |
| } |
| |
| if (same_entry(entry+0, entry+2) || both_empty(entry+0, entry+2)) { |
| /* We added, modified or removed, they did not touch -- take ours */ |
| resolve(info, NULL, entry+1); |
| return mask; |
| } |
| |
| unresolved(info, entry); |
| return mask; |
| } |
| |
| static void merge_trees(struct tree_desc t[3], const char *base) |
| { |
| struct traverse_info info; |
| |
| setup_traverse_info(&info, base); |
| info.fn = threeway_callback; |
| traverse_trees(3, t, &info); |
| } |
| |
| static void *get_tree_descriptor(struct tree_desc *desc, const char *rev) |
| { |
| unsigned char sha1[20]; |
| void *buf; |
| |
| if (get_sha1(rev, sha1)) |
| die("unknown rev %s", rev); |
| buf = fill_tree_descriptor(desc, sha1); |
| if (!buf) |
| die("%s is not a tree", rev); |
| return buf; |
| } |
| |
| int cmd_merge_tree(int argc, const char **argv, const char *prefix) |
| { |
| struct tree_desc t[3]; |
| void *buf1, *buf2, *buf3; |
| |
| if (argc != 4) |
| usage(merge_tree_usage); |
| |
| buf1 = get_tree_descriptor(t+0, argv[1]); |
| buf2 = get_tree_descriptor(t+1, argv[2]); |
| buf3 = get_tree_descriptor(t+2, argv[3]); |
| merge_trees(t, ""); |
| free(buf1); |
| free(buf2); |
| free(buf3); |
| |
| show_result(); |
| return 0; |
| } |