Convert struct object to object_id
[git/git.git] / builtin / merge-tree.c
CommitLineData
c2e86add 1#include "builtin.h"
1b0c7174 2#include "tree-walk.h"
0c799383 3#include "xdiff-interface.h"
83788070 4#include "blob.h"
2fb3f6db 5#include "exec_cmd.h"
fa2364ec 6#include "merge-blobs.h"
492e0759 7
34263de0 8static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
492e0759 9
83788070
LT
10struct merge_list {
11 struct merge_list *next;
12 struct merge_list *link; /* other stages for this object */
13
b13112fa 14 unsigned int stage : 2;
83788070
LT
15 unsigned int mode;
16 const char *path;
17 struct blob *blob;
18};
19
20static struct merge_list *merge_result, **merge_result_end = &merge_result;
21
22static void add_merge_entry(struct merge_list *entry)
23{
24 *merge_result_end = entry;
25 merge_result_end = &entry->next;
26}
27
57065289 28static void merge_trees(struct tree_desc t[3], const char *base);
492e0759 29
83788070
LT
30static const char *explanation(struct merge_list *entry)
31{
32 switch (entry->stage) {
33 case 0:
34 return "merged";
35 case 3:
36 return "added in remote";
37 case 2:
38 if (entry->link)
39 return "added in both";
40 return "added in local";
41 }
42
43 /* Existed in base */
44 entry = entry->link;
45 if (!entry)
46 return "removed in both";
47
48 if (entry->link)
49 return "changed in both";
50
51 if (entry->stage == 3)
52 return "removed in local";
53 return "removed in remote";
54}
55
0c799383
LT
56static void *result(struct merge_list *entry, unsigned long *size)
57{
21666f1a 58 enum object_type type;
0c799383 59 struct blob *base, *our, *their;
21baa6e0 60 const char *path = entry->path;
0c799383
LT
61
62 if (!entry->stage)
7999b2cf 63 return read_sha1_file(get_object_hash(entry->blob->object), &type, size);
0c799383
LT
64 base = NULL;
65 if (entry->stage == 1) {
66 base = entry->blob;
67 entry = entry->link;
68 }
69 our = NULL;
70 if (entry && entry->stage == 2) {
71 our = entry->blob;
72 entry = entry->link;
73 }
74 their = NULL;
75 if (entry)
76 their = entry->blob;
fa2364ec 77 return merge_blobs(path, base, our, their, size);
0c799383
LT
78}
79
80static void *origin(struct merge_list *entry, unsigned long *size)
81{
21666f1a 82 enum object_type type;
0c799383
LT
83 while (entry) {
84 if (entry->stage == 2)
7999b2cf 85 return read_sha1_file(get_object_hash(entry->blob->object), &type, size);
0c799383
LT
86 entry = entry->link;
87 }
88 return NULL;
89}
90
91static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf)
92{
93 int i;
94 for (i = 0; i < nbuf; i++)
95 printf("%.*s", (int) mb[i].size, mb[i].ptr);
96 return 0;
97}
98
99static void show_diff(struct merge_list *entry)
100{
101 unsigned long size;
102 mmfile_t src, dst;
103 xpparam_t xpp;
104 xdemitconf_t xecfg;
105 xdemitcb_t ecb;
106
582aa00b 107 xpp.flags = 0;
30b25010 108 memset(&xecfg, 0, sizeof(xecfg));
0c799383 109 xecfg.ctxlen = 3;
0c799383
LT
110 ecb.outf = show_outf;
111 ecb.priv = NULL;
112
113 src.ptr = origin(entry, &size);
114 if (!src.ptr)
115 size = 0;
116 src.size = size;
117 dst.ptr = result(entry, &size);
118 if (!dst.ptr)
119 size = 0;
120 dst.size = size;
3efb9880
JK
121 if (xdi_diff(&src, &dst, &xpp, &xecfg, &ecb))
122 die("unable to generate diff");
0c799383
LT
123 free(src.ptr);
124 free(dst.ptr);
125}
126
83788070
LT
127static void show_result_list(struct merge_list *entry)
128{
129 printf("%s\n", explanation(entry));
130 do {
131 struct merge_list *link = entry->link;
132 static const char *desc[4] = { "result", "base", "our", "their" };
f2fd0760 133 printf(" %-6s %o %s %s\n", desc[entry->stage], entry->mode, oid_to_hex(&entry->blob->object.oid), entry->path);
83788070
LT
134 entry = link;
135 } while (entry);
136}
137
138static void show_result(void)
139{
140 struct merge_list *walk;
141
142 walk = merge_result;
143 while (walk) {
144 show_result_list(walk);
0c799383 145 show_diff(walk);
83788070
LT
146 walk = walk->next;
147 }
148}
149
492e0759
LT
150/* An empty entry never compares same, not even to another empty entry */
151static int same_entry(struct name_entry *a, struct name_entry *b)
152{
153 return a->sha1 &&
154 b->sha1 &&
a89fccd2 155 !hashcmp(a->sha1, b->sha1) &&
492e0759
LT
156 a->mode == b->mode;
157}
158
aacecc3b
JK
159static int both_empty(struct name_entry *a, struct name_entry *b)
160{
161 return !(a->sha1 || b->sha1);
162}
163
83788070 164static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path)
492e0759 165{
19d4b416 166 struct merge_list *res = xcalloc(1, sizeof(*res));
83788070 167
83788070
LT
168 res->stage = stage;
169 res->path = path;
170 res->mode = mode;
171 res->blob = lookup_blob(sha1);
172 return res;
01df5297
LT
173}
174
40d934df
LT
175static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
176{
177 char *path = xmalloc(traverse_path_len(info, n) + 1);
178 return make_traverse_path(path, info, n);
179}
180
8dd15c6a 181static void resolve(const struct traverse_info *info, struct name_entry *ours, struct name_entry *result)
01df5297 182{
83788070
LT
183 struct merge_list *orig, *final;
184 const char *path;
185
8dd15c6a
JH
186 /* If it's already ours, don't bother showing it */
187 if (!ours)
01df5297 188 return;
01df5297 189
40d934df 190 path = traverse_path(info, result);
8dd15c6a 191 orig = create_entry(2, ours->mode, ours->sha1, path);
83788070
LT
192 final = create_entry(0, result->mode, result->sha1, path);
193
194 final->link = orig;
195
196 add_merge_entry(final);
492e0759
LT
197}
198
57065289
RS
199static void unresolved_directory(const struct traverse_info *info,
200 struct name_entry n[3])
492e0759 201{
492e0759
LT
202 char *newbase;
203 struct name_entry *p;
204 struct tree_desc t[3];
205 void *buf0, *buf1, *buf2;
206
35ffe758
JH
207 for (p = n; p < n + 3; p++) {
208 if (p->mode && S_ISDIR(p->mode))
209 break;
492e0759 210 }
35ffe758
JH
211 if (n + 3 <= p)
212 return; /* there is no tree here */
8dd15c6a 213
40d934df 214 newbase = traverse_path(info, p);
35ffe758
JH
215
216#define ENTRY_SHA1(e) (((e)->mode && S_ISDIR((e)->mode)) ? (e)->sha1 : NULL)
217 buf0 = fill_tree_descriptor(t+0, ENTRY_SHA1(n + 0));
218 buf1 = fill_tree_descriptor(t+1, ENTRY_SHA1(n + 1));
219 buf2 = fill_tree_descriptor(t+2, ENTRY_SHA1(n + 2));
220#undef ENTRY_SHA1
221
57065289 222 merge_trees(t, newbase);
492e0759
LT
223
224 free(buf0);
225 free(buf1);
226 free(buf2);
227 free(newbase);
492e0759
LT
228}
229
83788070 230
40d934df 231static struct merge_list *link_entry(unsigned stage, const struct traverse_info *info, struct name_entry *n, struct merge_list *entry)
83788070
LT
232{
233 const char *path;
234 struct merge_list *link;
235
236 if (!n->mode)
237 return entry;
238 if (entry)
239 path = entry->path;
240 else
40d934df 241 path = traverse_path(info, n);
83788070
LT
242 link = create_entry(stage, n->mode, n->sha1, path);
243 link->link = entry;
244 return link;
245}
246
40d934df 247static void unresolved(const struct traverse_info *info, struct name_entry n[3])
492e0759 248{
83788070 249 struct merge_list *entry = NULL;
35ffe758
JH
250 int i;
251 unsigned dirmask = 0, mask = 0;
252
253 for (i = 0; i < 3; i++) {
187c00c6 254 mask |= (1 << i);
94883b43
JK
255 /*
256 * Treat missing entries as directories so that we return
257 * after unresolved_directory has handled this.
258 */
259 if (!n[i].mode || S_ISDIR(n[i].mode))
35ffe758
JH
260 dirmask |= (1 << i);
261 }
262
57065289 263 unresolved_directory(info, n);
83788070 264
35ffe758 265 if (dirmask == mask)
492e0759 266 return;
83788070 267
35ffe758
JH
268 if (n[2].mode && !S_ISDIR(n[2].mode))
269 entry = link_entry(3, info, n + 2, entry);
270 if (n[1].mode && !S_ISDIR(n[1].mode))
271 entry = link_entry(2, info, n + 1, entry);
272 if (n[0].mode && !S_ISDIR(n[0].mode))
273 entry = link_entry(1, info, n + 0, entry);
83788070
LT
274
275 add_merge_entry(entry);
492e0759
LT
276}
277
164dcb97
LT
278/*
279 * Merge two trees together (t[1] and t[2]), using a common base (t[0])
280 * as the origin.
281 *
282 * This walks the (sorted) trees in lock-step, checking every possible
283 * name. Note that directories automatically sort differently from other
284 * files (see "base_name_compare"), so you'll never see file/directory
285 * conflicts, because they won't ever compare the same.
286 *
287 * IOW, if a directory changes to a filename, it will automatically be
288 * seen as the directory going away, and the filename being created.
289 *
290 * Think of this as a three-way diff.
291 *
292 * The output will be either:
293 * - successful merge
294 * "0 mode sha1 filename"
295 * NOTE NOTE NOTE! FIXME! We really really need to walk the index
296 * in parallel with this too!
297 *
298 * - conflict:
299 * "1 mode sha1 filename"
300 * "2 mode sha1 filename"
301 * "3 mode sha1 filename"
302 * where not all of the 1/2/3 lines may exist, of course.
303 *
304 * The successful merge rules are the same as for the three-way merge
305 * in git-read-tree.
306 */
91e4f036 307static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *info)
164dcb97
LT
308{
309 /* Same in both? */
ab5f4242 310 if (same_entry(entry+1, entry+2) || both_empty(entry+1, entry+2)) {
aacecc3b
JK
311 /* Modified, added or removed identically */
312 resolve(info, NULL, entry+1);
313 return mask;
164dcb97 314 }
492e0759 315
164dcb97
LT
316 if (same_entry(entry+0, entry+1)) {
317 if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
8dd15c6a 318 /* We did not touch, they modified -- take theirs */
40d934df 319 resolve(info, entry+1, entry+2);
5803c6f8 320 return mask;
492e0759 321 }
8dd15c6a
JH
322 /*
323 * If we did not touch a directory but they made it
324 * into a file, we fall through and unresolved()
325 * recurses down. Likewise for the opposite case.
326 */
164dcb97 327 }
492e0759 328
aacecc3b
JK
329 if (same_entry(entry+0, entry+2) || both_empty(entry+0, entry+2)) {
330 /* We added, modified or removed, they did not touch -- take ours */
331 resolve(info, NULL, entry+1);
332 return mask;
492e0759 333 }
164dcb97 334
40d934df 335 unresolved(info, entry);
5803c6f8 336 return mask;
164dcb97
LT
337}
338
57065289 339static void merge_trees(struct tree_desc t[3], const char *base)
164dcb97 340{
40d934df
LT
341 struct traverse_info info;
342
343 setup_traverse_info(&info, base);
344 info.fn = threeway_callback;
345 traverse_trees(3, t, &info);
492e0759
LT
346}
347
348static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
349{
350 unsigned char sha1[20];
351 void *buf;
352
31fff305 353 if (get_sha1(rev, sha1))
492e0759
LT
354 die("unknown rev %s", rev);
355 buf = fill_tree_descriptor(desc, sha1);
356 if (!buf)
357 die("%s is not a tree", rev);
358 return buf;
359}
360
907a7cb5 361int cmd_merge_tree(int argc, const char **argv, const char *prefix)
492e0759
LT
362{
363 struct tree_desc t[3];
364 void *buf1, *buf2, *buf3;
365
5b6df8e4 366 if (argc != 4)
492e0759
LT
367 usage(merge_tree_usage);
368
369 buf1 = get_tree_descriptor(t+0, argv[1]);
370 buf2 = get_tree_descriptor(t+1, argv[2]);
371 buf3 = get_tree_descriptor(t+2, argv[3]);
372 merge_trees(t, "");
373 free(buf1);
374 free(buf2);
375 free(buf3);
83788070
LT
376
377 show_result();
492e0759
LT
378 return 0;
379}