mingw: implement getppid
[git/kusma.git] / builtin / merge-tree.c
blob9b25ddc9794efe489ee9ec9fd3203ffa997f03f7
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "xdiff-interface.h"
4 #include "blob.h"
5 #include "exec_cmd.h"
7 static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
8 static int resolve_directories = 1;
10 struct merge_list {
11 struct merge_list *next;
12 struct merge_list *link; /* other stages for this object */
14 unsigned int stage : 2,
15 flags : 30;
16 unsigned int mode;
17 const char *path;
18 struct blob *blob;
21 static struct merge_list *merge_result, **merge_result_end = &merge_result;
23 static void add_merge_entry(struct merge_list *entry)
25 *merge_result_end = entry;
26 merge_result_end = &entry->next;
29 static void merge_trees(struct tree_desc t[3], const char *base);
31 static const char *explanation(struct merge_list *entry)
33 switch (entry->stage) {
34 case 0:
35 return "merged";
36 case 3:
37 return "added in remote";
38 case 2:
39 if (entry->link)
40 return "added in both";
41 return "added in local";
44 /* Existed in base */
45 entry = entry->link;
46 if (!entry)
47 return "removed in both";
49 if (entry->link)
50 return "changed in both";
52 if (entry->stage == 3)
53 return "removed in local";
54 return "removed in remote";
57 extern void *merge_file(const char *, struct blob *, struct blob *, struct blob *, unsigned long *);
59 static void *result(struct merge_list *entry, unsigned long *size)
61 enum object_type type;
62 struct blob *base, *our, *their;
63 const char *path = entry->path;
65 if (!entry->stage)
66 return read_sha1_file(entry->blob->object.sha1, &type, size);
67 base = NULL;
68 if (entry->stage == 1) {
69 base = entry->blob;
70 entry = entry->link;
72 our = NULL;
73 if (entry && entry->stage == 2) {
74 our = entry->blob;
75 entry = entry->link;
77 their = NULL;
78 if (entry)
79 their = entry->blob;
80 return merge_file(path, base, our, their, size);
83 static void *origin(struct merge_list *entry, unsigned long *size)
85 enum object_type type;
86 while (entry) {
87 if (entry->stage == 2)
88 return read_sha1_file(entry->blob->object.sha1, &type, size);
89 entry = entry->link;
91 return NULL;
94 static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf)
96 int i;
97 for (i = 0; i < nbuf; i++)
98 printf("%.*s", (int) mb[i].size, mb[i].ptr);
99 return 0;
102 static void show_diff(struct merge_list *entry)
104 unsigned long size;
105 mmfile_t src, dst;
106 xpparam_t xpp;
107 xdemitconf_t xecfg;
108 xdemitcb_t ecb;
110 xpp.flags = 0;
111 memset(&xecfg, 0, sizeof(xecfg));
112 xecfg.ctxlen = 3;
113 ecb.outf = show_outf;
114 ecb.priv = NULL;
116 src.ptr = origin(entry, &size);
117 if (!src.ptr)
118 size = 0;
119 src.size = size;
120 dst.ptr = result(entry, &size);
121 if (!dst.ptr)
122 size = 0;
123 dst.size = size;
124 xdi_diff(&src, &dst, &xpp, &xecfg, &ecb);
125 free(src.ptr);
126 free(dst.ptr);
129 static void show_result_list(struct merge_list *entry)
131 printf("%s\n", explanation(entry));
132 do {
133 struct merge_list *link = entry->link;
134 static const char *desc[4] = { "result", "base", "our", "their" };
135 printf(" %-6s %o %s %s\n", desc[entry->stage], entry->mode, sha1_to_hex(entry->blob->object.sha1), entry->path);
136 entry = link;
137 } while (entry);
140 static void show_result(void)
142 struct merge_list *walk;
144 walk = merge_result;
145 while (walk) {
146 show_result_list(walk);
147 show_diff(walk);
148 walk = walk->next;
152 /* An empty entry never compares same, not even to another empty entry */
153 static int same_entry(struct name_entry *a, struct name_entry *b)
155 return a->sha1 &&
156 b->sha1 &&
157 !hashcmp(a->sha1, b->sha1) &&
158 a->mode == b->mode;
161 static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path)
163 struct merge_list *res = xcalloc(1, sizeof(*res));
165 res->stage = stage;
166 res->path = path;
167 res->mode = mode;
168 res->blob = lookup_blob(sha1);
169 return res;
172 static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
174 char *path = xmalloc(traverse_path_len(info, n) + 1);
175 return make_traverse_path(path, info, n);
178 static void resolve(const struct traverse_info *info, struct name_entry *branch1, struct name_entry *result)
180 struct merge_list *orig, *final;
181 const char *path;
183 /* If it's already branch1, don't bother showing it */
184 if (!branch1)
185 return;
187 path = traverse_path(info, result);
188 orig = create_entry(2, branch1->mode, branch1->sha1, path);
189 final = create_entry(0, result->mode, result->sha1, path);
191 final->link = orig;
193 add_merge_entry(final);
196 static int unresolved_directory(const struct traverse_info *info, struct name_entry n[3])
198 char *newbase;
199 struct name_entry *p;
200 struct tree_desc t[3];
201 void *buf0, *buf1, *buf2;
203 if (!resolve_directories)
204 return 0;
205 p = n;
206 if (!p->mode) {
207 p++;
208 if (!p->mode)
209 p++;
211 if (!S_ISDIR(p->mode))
212 return 0;
213 newbase = traverse_path(info, p);
214 buf0 = fill_tree_descriptor(t+0, n[0].sha1);
215 buf1 = fill_tree_descriptor(t+1, n[1].sha1);
216 buf2 = fill_tree_descriptor(t+2, n[2].sha1);
217 merge_trees(t, newbase);
219 free(buf0);
220 free(buf1);
221 free(buf2);
222 free(newbase);
223 return 1;
227 static struct merge_list *link_entry(unsigned stage, const struct traverse_info *info, struct name_entry *n, struct merge_list *entry)
229 const char *path;
230 struct merge_list *link;
232 if (!n->mode)
233 return entry;
234 if (entry)
235 path = entry->path;
236 else
237 path = traverse_path(info, n);
238 link = create_entry(stage, n->mode, n->sha1, path);
239 link->link = entry;
240 return link;
243 static void unresolved(const struct traverse_info *info, struct name_entry n[3])
245 struct merge_list *entry = NULL;
247 if (unresolved_directory(info, n))
248 return;
251 * Do them in reverse order so that the resulting link
252 * list has the stages in order - link_entry adds new
253 * links at the front.
255 entry = link_entry(3, info, n + 2, entry);
256 entry = link_entry(2, info, n + 1, entry);
257 entry = link_entry(1, info, n + 0, entry);
259 add_merge_entry(entry);
263 * Merge two trees together (t[1] and t[2]), using a common base (t[0])
264 * as the origin.
266 * This walks the (sorted) trees in lock-step, checking every possible
267 * name. Note that directories automatically sort differently from other
268 * files (see "base_name_compare"), so you'll never see file/directory
269 * conflicts, because they won't ever compare the same.
271 * IOW, if a directory changes to a filename, it will automatically be
272 * seen as the directory going away, and the filename being created.
274 * Think of this as a three-way diff.
276 * The output will be either:
277 * - successful merge
278 * "0 mode sha1 filename"
279 * NOTE NOTE NOTE! FIXME! We really really need to walk the index
280 * in parallel with this too!
282 * - conflict:
283 * "1 mode sha1 filename"
284 * "2 mode sha1 filename"
285 * "3 mode sha1 filename"
286 * where not all of the 1/2/3 lines may exist, of course.
288 * The successful merge rules are the same as for the three-way merge
289 * in git-read-tree.
291 static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *info)
293 /* Same in both? */
294 if (same_entry(entry+1, entry+2)) {
295 if (entry[0].sha1) {
296 resolve(info, NULL, entry+1);
297 return mask;
301 if (same_entry(entry+0, entry+1)) {
302 if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
303 resolve(info, entry+1, entry+2);
304 return mask;
308 if (same_entry(entry+0, entry+2)) {
309 if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) {
310 resolve(info, NULL, entry+1);
311 return mask;
315 unresolved(info, entry);
316 return mask;
319 static void merge_trees(struct tree_desc t[3], const char *base)
321 struct traverse_info info;
323 setup_traverse_info(&info, base);
324 info.fn = threeway_callback;
325 traverse_trees(3, t, &info);
328 static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
330 unsigned char sha1[20];
331 void *buf;
333 if (get_sha1(rev, sha1))
334 die("unknown rev %s", rev);
335 buf = fill_tree_descriptor(desc, sha1);
336 if (!buf)
337 die("%s is not a tree", rev);
338 return buf;
341 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
343 struct tree_desc t[3];
344 void *buf1, *buf2, *buf3;
346 if (argc != 4)
347 usage(merge_tree_usage);
349 buf1 = get_tree_descriptor(t+0, argv[1]);
350 buf2 = get_tree_descriptor(t+1, argv[2]);
351 buf3 = get_tree_descriptor(t+2, argv[3]);
352 merge_trees(t, "");
353 free(buf1);
354 free(buf2);
355 free(buf3);
357 show_result();
358 return 0;