ll-merge: replace flag argument with options struct
[git/git.git] / rerere.c
CommitLineData
5b2fd956 1#include "cache.h"
c455c87c 2#include "string-list.h"
5b2fd956 3#include "rerere.h"
5b2fd956 4#include "xdiff-interface.h"
dea4562b
JH
5#include "dir.h"
6#include "resolve-undo.h"
7#include "ll-merge.h"
8588567c 8#include "attr.h"
5b2fd956
SB
9
10/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
11static int rerere_enabled = -1;
12
13/* automatically update cleanly resolved paths to the index */
14static int rerere_autoupdate;
15
16static char *merge_rr_path;
17
90056966 18const char *rerere_path(const char *hex, const char *file)
5b2fd956 19{
90056966 20 return git_path("rr-cache/%s/%s", hex, file);
5b2fd956
SB
21}
22
90056966 23int has_rerere_resolution(const char *hex)
5b2fd956
SB
24{
25 struct stat st;
90056966 26 return !stat(rerere_path(hex, "postimage"), &st);
5b2fd956
SB
27}
28
c455c87c 29static void read_rr(struct string_list *rr)
5b2fd956
SB
30{
31 unsigned char sha1[20];
32 char buf[PATH_MAX];
33 FILE *in = fopen(merge_rr_path, "r");
34 if (!in)
35 return;
36 while (fread(buf, 40, 1, in) == 1) {
37 int i;
38 char *name;
39 if (get_sha1_hex(buf, sha1))
40 die("corrupt MERGE_RR");
41 buf[40] = '\0';
42 name = xstrdup(buf);
43 if (fgetc(in) != '\t')
44 die("corrupt MERGE_RR");
45 for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
46 ; /* do nothing */
47 if (i == sizeof(buf))
48 die("filename too long");
c455c87c 49 string_list_insert(buf, rr)->util = name;
5b2fd956
SB
50 }
51 fclose(in);
52}
53
54static struct lock_file write_lock;
55
c455c87c 56static int write_rr(struct string_list *rr, int out_fd)
5b2fd956
SB
57{
58 int i;
59 for (i = 0; i < rr->nr; i++) {
60 const char *path;
61 int length;
62 if (!rr->items[i].util)
63 continue;
c455c87c 64 path = rr->items[i].string;
5b2fd956
SB
65 length = strlen(path) + 1;
66 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
2b7ca830 67 write_str_in_full(out_fd, "\t") != 1 ||
5b2fd956
SB
68 write_in_full(out_fd, path, length) != length)
69 die("unable to write rerere record");
70 }
71 if (commit_lock_file(&write_lock) != 0)
72 die("unable to write rerere record");
73 return 0;
74}
75
47d32af2
AR
76static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
77{
78 if (!count || *err)
79 return;
80 if (fwrite(p, count, 1, fp) != 1)
81 *err = errno;
82}
83
84static inline void ferr_puts(const char *s, FILE *fp, int *err)
85{
86 ferr_write(s, strlen(s), fp, err);
87}
88
27d6b085
JH
89struct rerere_io {
90 int (*getline)(struct strbuf *, struct rerere_io *);
91 FILE *output;
92 int wrerror;
93 /* some more stuff */
94};
95
96static void rerere_io_putstr(const char *str, struct rerere_io *io)
97{
98 if (io->output)
99 ferr_puts(str, io->output, &io->wrerror);
100}
101
191f2417
JH
102static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
103{
104 char buf[64];
105
106 while (size) {
107 if (size < sizeof(buf) - 2) {
108 memset(buf, ch, size);
109 buf[size] = '\n';
110 buf[size + 1] = '\0';
111 size = 0;
112 } else {
113 int sz = sizeof(buf) - 1;
114 if (size <= sz)
115 sz -= (sz - size) + 1;
116 memset(buf, ch, sz);
117 buf[sz] = '\0';
118 size -= sz;
119 }
120 rerere_io_putstr(buf, io);
121 }
122}
123
27d6b085
JH
124static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
125{
126 if (io->output)
127 ferr_write(mem, sz, io->output, &io->wrerror);
128}
129
130struct rerere_io_file {
131 struct rerere_io io;
132 FILE *input;
133};
134
135static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
136{
137 struct rerere_io_file *io = (struct rerere_io_file *)io_;
138 return strbuf_getwholeline(sb, io->input, '\n');
139}
140
191f2417
JH
141static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
142{
143 while (marker_size--)
144 if (*buf++ != marker_char)
145 return 0;
146 if (want_sp && *buf != ' ')
147 return 0;
148 return isspace(*buf);
149}
150
151static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
5b2fd956 152{
9126f009 153 git_SHA_CTX ctx;
cc58d7df
JH
154 int hunk_no = 0;
155 enum {
4b05548f 156 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
cc58d7df 157 } hunk = RR_CONTEXT;
f285a2d7 158 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
d58ee6db 159 struct strbuf buf = STRBUF_INIT;
5b2fd956
SB
160
161 if (sha1)
9126f009 162 git_SHA1_Init(&ctx);
5b2fd956 163
27d6b085 164 while (!io->getline(&buf, io)) {
191f2417 165 if (is_cmarker(buf.buf, '<', marker_size, 1)) {
cc58d7df 166 if (hunk != RR_CONTEXT)
5b2fd956 167 goto bad;
cc58d7df 168 hunk = RR_SIDE_1;
191f2417 169 } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
cc58d7df 170 if (hunk != RR_SIDE_1)
5b2fd956 171 goto bad;
387c9d49 172 hunk = RR_ORIGINAL;
191f2417 173 } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
387c9d49 174 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
5b2fd956 175 goto bad;
cc58d7df 176 hunk = RR_SIDE_2;
191f2417 177 } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
cc58d7df 178 if (hunk != RR_SIDE_2)
5b2fd956
SB
179 goto bad;
180 if (strbuf_cmp(&one, &two) > 0)
181 strbuf_swap(&one, &two);
182 hunk_no++;
cc58d7df 183 hunk = RR_CONTEXT;
191f2417 184 rerere_io_putconflict('<', marker_size, io);
27d6b085 185 rerere_io_putmem(one.buf, one.len, io);
191f2417 186 rerere_io_putconflict('=', marker_size, io);
27d6b085 187 rerere_io_putmem(two.buf, two.len, io);
191f2417 188 rerere_io_putconflict('>', marker_size, io);
5b2fd956 189 if (sha1) {
9126f009 190 git_SHA1_Update(&ctx, one.buf ? one.buf : "",
5b2fd956 191 one.len + 1);
9126f009 192 git_SHA1_Update(&ctx, two.buf ? two.buf : "",
5b2fd956
SB
193 two.len + 1);
194 }
195 strbuf_reset(&one);
196 strbuf_reset(&two);
cc58d7df 197 } else if (hunk == RR_SIDE_1)
d58ee6db 198 strbuf_addstr(&one, buf.buf);
387c9d49
JH
199 else if (hunk == RR_ORIGINAL)
200 ; /* discard */
cc58d7df 201 else if (hunk == RR_SIDE_2)
d58ee6db 202 strbuf_addstr(&two, buf.buf);
27d6b085
JH
203 else
204 rerere_io_putstr(buf.buf, io);
5b2fd956
SB
205 continue;
206 bad:
207 hunk = 99; /* force error exit */
208 break;
209 }
210 strbuf_release(&one);
211 strbuf_release(&two);
d58ee6db 212 strbuf_release(&buf);
5b2fd956 213
5b2fd956 214 if (sha1)
9126f009 215 git_SHA1_Final(sha1, &ctx);
27d6b085
JH
216 if (hunk != RR_CONTEXT)
217 return -1;
218 return hunk_no;
219}
220
221static int handle_file(const char *path, unsigned char *sha1, const char *output)
222{
223 int hunk_no = 0;
224 struct rerere_io_file io;
8588567c 225 int marker_size = ll_merge_marker_size(path);
27d6b085
JH
226
227 memset(&io, 0, sizeof(io));
228 io.io.getline = rerere_file_getline;
229 io.input = fopen(path, "r");
230 io.io.wrerror = 0;
231 if (!io.input)
232 return error("Could not open %s", path);
233
234 if (output) {
235 io.io.output = fopen(output, "w");
236 if (!io.io.output) {
237 fclose(io.input);
238 return error("Could not write %s", output);
239 }
240 }
241
191f2417 242 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
27d6b085
JH
243
244 fclose(io.input);
245 if (io.io.wrerror)
246 error("There were errors while writing %s (%s)",
247 path, strerror(io.io.wrerror));
248 if (io.io.output && fclose(io.io.output))
249 io.io.wrerror = error("Failed to flush %s: %s",
250 path, strerror(errno));
251
252 if (hunk_no < 0) {
5b2fd956 253 if (output)
691f1a28 254 unlink_or_warn(output);
5b2fd956
SB
255 return error("Could not parse conflict hunks in %s", path);
256 }
27d6b085 257 if (io.io.wrerror)
47d32af2 258 return -1;
5b2fd956
SB
259 return hunk_no;
260}
261
dea4562b
JH
262struct rerere_io_mem {
263 struct rerere_io io;
264 struct strbuf input;
265};
266
267static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
268{
269 struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
270 char *ep;
271 size_t len;
272
273 strbuf_release(sb);
274 if (!io->input.len)
275 return -1;
276 ep = strchrnul(io->input.buf, '\n');
277 if (*ep == '\n')
278 ep++;
279 len = ep - io->input.buf;
280 strbuf_add(sb, io->input.buf, len);
281 strbuf_remove(&io->input, 0, len);
282 return 0;
283}
284
285static int handle_cache(const char *path, unsigned char *sha1, const char *output)
286{
287 mmfile_t mmfile[3];
288 mmbuffer_t result = {NULL, 0};
289 struct cache_entry *ce;
290 int pos, len, i, hunk_no;
291 struct rerere_io_mem io;
8588567c 292 int marker_size = ll_merge_marker_size(path);
dea4562b
JH
293
294 /*
295 * Reproduce the conflicted merge in-core
296 */
297 len = strlen(path);
298 pos = cache_name_pos(path, len);
299 if (0 <= pos)
47d32af2 300 return -1;
dea4562b
JH
301 pos = -pos - 1;
302
303 for (i = 0; i < 3; i++) {
304 enum object_type type;
305 unsigned long size;
306
307 mmfile[i].size = 0;
308 mmfile[i].ptr = NULL;
309 if (active_nr <= pos)
310 break;
311 ce = active_cache[pos++];
312 if (ce_namelen(ce) != len || memcmp(ce->name, path, len)
313 || ce_stage(ce) != i + 1)
314 break;
315 mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
316 mmfile[i].size = size;
317 }
318 for (i = 0; i < 3; i++) {
319 if (!mmfile[i].ptr && !mmfile[i].size)
320 mmfile[i].ptr = xstrdup("");
321 }
18b037a5
JN
322 /*
323 * NEEDSWORK: handle conflicts from merges with
324 * merge.renormalize set, too
325 */
f01de62e 326 ll_merge(&result, path, &mmfile[0], NULL,
dea4562b 327 &mmfile[1], "ours",
712516bc 328 &mmfile[2], "theirs", NULL);
dea4562b
JH
329 for (i = 0; i < 3; i++)
330 free(mmfile[i].ptr);
331
af86debc 332 memset(&io, 0, sizeof(io));
dea4562b
JH
333 io.io.getline = rerere_mem_getline;
334 if (output)
335 io.io.output = fopen(output, "w");
336 else
337 io.io.output = NULL;
338 strbuf_init(&io.input, 0);
339 strbuf_attach(&io.input, result.ptr, result.size, result.size);
340
191f2417 341 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
dea4562b
JH
342 strbuf_release(&io.input);
343 if (io.io.output)
344 fclose(io.io.output);
5b2fd956
SB
345 return hunk_no;
346}
347
c455c87c 348static int find_conflict(struct string_list *conflict)
5b2fd956
SB
349{
350 int i;
351 if (read_cache() < 0)
352 return error("Could not read index");
353 for (i = 0; i+1 < active_nr; i++) {
354 struct cache_entry *e2 = active_cache[i];
355 struct cache_entry *e3 = active_cache[i+1];
356 if (ce_stage(e2) == 2 &&
357 ce_stage(e3) == 3 &&
358 ce_same_name(e2, e3) &&
359 S_ISREG(e2->ce_mode) &&
360 S_ISREG(e3->ce_mode)) {
c455c87c 361 string_list_insert((const char *)e2->name, conflict);
5b2fd956
SB
362 i++; /* skip over both #2 and #3 */
363 }
364 }
365 return 0;
366}
367
ff8ba59e 368static int merge(const char *name, const char *path)
5b2fd956
SB
369{
370 int ret;
689b8c29 371 mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
5b2fd956 372 mmbuffer_t result = {NULL, 0};
5b2fd956 373
90056966 374 if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
5b2fd956
SB
375 return 1;
376
90056966
SG
377 if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
378 read_mmfile(&base, rerere_path(name, "preimage")) ||
689b8c29
BW
379 read_mmfile(&other, rerere_path(name, "postimage"))) {
380 ret = 1;
381 goto out;
382 }
ff8ba59e 383 ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", 0);
5b2fd956
SB
384 if (!ret) {
385 FILE *f = fopen(path, "w");
386 if (!f)
47d32af2
AR
387 return error("Could not open %s: %s", path,
388 strerror(errno));
389 if (fwrite(result.ptr, result.size, 1, f) != 1)
390 error("Could not write %s: %s", path, strerror(errno));
391 if (fclose(f))
392 return error("Writing %s failed: %s", path,
393 strerror(errno));
5b2fd956
SB
394 }
395
689b8c29 396out:
5b2fd956
SB
397 free(cur.ptr);
398 free(base.ptr);
399 free(other.ptr);
400 free(result.ptr);
401
402 return ret;
403}
404
405static struct lock_file index_lock;
406
c455c87c 407static int update_paths(struct string_list *update)
5b2fd956
SB
408{
409 int i;
410 int fd = hold_locked_index(&index_lock, 0);
411 int status = 0;
412
413 if (fd < 0)
414 return -1;
415
416 for (i = 0; i < update->nr; i++) {
c455c87c
JS
417 struct string_list_item *item = &update->items[i];
418 if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
5b2fd956
SB
419 status = -1;
420 }
421
422 if (!status && active_cache_changed) {
423 if (write_cache(fd, active_cache, active_nr) ||
424 commit_locked_index(&index_lock))
425 die("Unable to write new index file");
426 } else if (fd >= 0)
427 rollback_lock_file(&index_lock);
428 return status;
429}
430
ff8ba59e 431static int do_plain_rerere(struct string_list *rr, int fd)
5b2fd956 432{
c455c87c
JS
433 struct string_list conflict = { NULL, 0, 0, 1 };
434 struct string_list update = { NULL, 0, 0, 1 };
5b2fd956
SB
435 int i;
436
437 find_conflict(&conflict);
438
439 /*
440 * MERGE_RR records paths with conflicts immediately after merge
441 * failed. Some of the conflicted paths might have been hand resolved
442 * in the working tree since then, but the initial run would catch all
443 * and register their preimages.
444 */
445
446 for (i = 0; i < conflict.nr; i++) {
c455c87c
JS
447 const char *path = conflict.items[i].string;
448 if (!string_list_has_string(rr, path)) {
5b2fd956
SB
449 unsigned char sha1[20];
450 char *hex;
451 int ret;
452 ret = handle_file(path, sha1, NULL);
453 if (ret < 1)
454 continue;
455 hex = xstrdup(sha1_to_hex(sha1));
c455c87c 456 string_list_insert(path, rr)->util = hex;
5b2fd956 457 if (mkdir(git_path("rr-cache/%s", hex), 0755))
ba19a808 458 continue;
90056966 459 handle_file(path, NULL, rerere_path(hex, "preimage"));
5b2fd956
SB
460 fprintf(stderr, "Recorded preimage for '%s'\n", path);
461 }
462 }
463
464 /*
465 * Now some of the paths that had conflicts earlier might have been
466 * hand resolved. Others may be similar to a conflict already that
467 * was resolved before.
468 */
469
470 for (i = 0; i < rr->nr; i++) {
471 int ret;
c455c87c 472 const char *path = rr->items[i].string;
5b2fd956
SB
473 const char *name = (const char *)rr->items[i].util;
474
90056966 475 if (has_rerere_resolution(name)) {
ff8ba59e 476 if (!merge(name, path)) {
5b2fd956 477 if (rerere_autoupdate)
c455c87c 478 string_list_insert(path, &update);
9196e825
JH
479 fprintf(stderr,
480 "%s '%s' using previous resolution.\n",
481 rerere_autoupdate
482 ? "Staged" : "Resolved",
483 path);
5b2fd956
SB
484 goto mark_resolved;
485 }
486 }
487
488 /* Let's see if we have resolved it. */
489 ret = handle_file(path, NULL, NULL);
490 if (ret)
491 continue;
492
493 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
90056966 494 copy_file(rerere_path(name, "postimage"), path, 0666);
5b2fd956
SB
495 mark_resolved:
496 rr->items[i].util = NULL;
497 }
498
499 if (update.nr)
500 update_paths(&update);
501
502 return write_rr(rr, fd);
503}
504
505static int git_rerere_config(const char *var, const char *value, void *cb)
506{
507 if (!strcmp(var, "rerere.enabled"))
508 rerere_enabled = git_config_bool(var, value);
509 else if (!strcmp(var, "rerere.autoupdate"))
510 rerere_autoupdate = git_config_bool(var, value);
511 else
512 return git_default_config(var, value, cb);
513 return 0;
514}
515
516static int is_rerere_enabled(void)
517{
5b2fd956
SB
518 const char *rr_cache;
519 int rr_cache_exists;
520
521 if (!rerere_enabled)
522 return 0;
523
524 rr_cache = git_path("rr-cache");
90b4a71c 525 rr_cache_exists = is_directory(rr_cache);
5b2fd956
SB
526 if (rerere_enabled < 0)
527 return rr_cache_exists;
528
529 if (!rr_cache_exists &&
530 (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
531 die("Could not create directory %s", rr_cache);
532 return 1;
533}
534
cb6020bb 535int setup_rerere(struct string_list *merge_rr, int flags)
5b2fd956
SB
536{
537 int fd;
538
539 git_config(git_rerere_config, NULL);
540 if (!is_rerere_enabled())
541 return -1;
542
cb6020bb
JH
543 if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
544 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
a4f34cbb 545 merge_rr_path = git_pathdup("MERGE_RR");
acd3b9ec
JH
546 fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
547 LOCK_DIE_ON_ERROR);
5b2fd956
SB
548 read_rr(merge_rr);
549 return fd;
550}
551
cb6020bb 552int rerere(int flags)
5b2fd956 553{
c455c87c 554 struct string_list merge_rr = { NULL, 0, 0, 1 };
5b2fd956
SB
555 int fd;
556
cb6020bb 557 fd = setup_rerere(&merge_rr, flags);
5b2fd956
SB
558 if (fd < 0)
559 return 0;
ff8ba59e 560 return do_plain_rerere(&merge_rr, fd);
5b2fd956 561}
dea4562b
JH
562
563static int rerere_forget_one_path(const char *path, struct string_list *rr)
564{
565 const char *filename;
566 char *hex;
567 unsigned char sha1[20];
568 int ret;
569
570 ret = handle_cache(path, sha1, NULL);
571 if (ret < 1)
572 return error("Could not parse conflict hunks in '%s'", path);
573 hex = xstrdup(sha1_to_hex(sha1));
574 filename = rerere_path(hex, "postimage");
575 if (unlink(filename))
576 return (errno == ENOENT
577 ? error("no remembered resolution for %s", path)
578 : error("cannot unlink %s: %s", filename, strerror(errno)));
579
580 handle_cache(path, sha1, rerere_path(hex, "preimage"));
581 fprintf(stderr, "Updated preimage for '%s'\n", path);
582
583
584 string_list_insert(path, rr)->util = hex;
585 fprintf(stderr, "Forgot resolution for %s\n", path);
586 return 0;
587}
588
589int rerere_forget(const char **pathspec)
590{
591 int i, fd;
592 struct string_list conflict = { NULL, 0, 0, 1 };
593 struct string_list merge_rr = { NULL, 0, 0, 1 };
594
595 if (read_cache() < 0)
596 return error("Could not read index");
597
6751e047 598 fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
dea4562b
JH
599
600 unmerge_cache(pathspec);
601 find_conflict(&conflict);
602 for (i = 0; i < conflict.nr; i++) {
603 struct string_list_item *it = &conflict.items[i];
604 if (!match_pathspec(pathspec, it->string, strlen(it->string),
605 0, NULL))
606 continue;
607 rerere_forget_one_path(it->string, &merge_rr);
608 }
609 return write_rr(&merge_rr, fd);
610}