Merge branch 'cb/test-lint-cp-a'
[git.git] / rerere.c
blob13624038e66c2084c478711599ed9f005cf2e53d
1 #include "cache.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "string-list.h"
5 #include "rerere.h"
6 #include "xdiff-interface.h"
7 #include "dir.h"
8 #include "resolve-undo.h"
9 #include "ll-merge.h"
10 #include "attr.h"
11 #include "pathspec.h"
12 #include "object-store.h"
13 #include "sha1-lookup.h"
15 #define RESOLVED 0
16 #define PUNTED 1
17 #define THREE_STAGED 2
18 void *RERERE_RESOLVED = &RERERE_RESOLVED;
20 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
21 static int rerere_enabled = -1;
23 /* automatically update cleanly resolved paths to the index */
24 static int rerere_autoupdate;
26 static int rerere_dir_nr;
27 static int rerere_dir_alloc;
29 #define RR_HAS_POSTIMAGE 1
30 #define RR_HAS_PREIMAGE 2
31 static struct rerere_dir {
32 unsigned char hash[GIT_MAX_HEXSZ];
33 int status_alloc, status_nr;
34 unsigned char *status;
35 } **rerere_dir;
37 static void free_rerere_dirs(void)
39 int i;
40 for (i = 0; i < rerere_dir_nr; i++) {
41 free(rerere_dir[i]->status);
42 free(rerere_dir[i]);
44 FREE_AND_NULL(rerere_dir);
45 rerere_dir_nr = rerere_dir_alloc = 0;
48 static void free_rerere_id(struct string_list_item *item)
50 free(item->util);
53 static const char *rerere_id_hex(const struct rerere_id *id)
55 return sha1_to_hex(id->collection->hash);
58 static void fit_variant(struct rerere_dir *rr_dir, int variant)
60 variant++;
61 ALLOC_GROW(rr_dir->status, variant, rr_dir->status_alloc);
62 if (rr_dir->status_nr < variant) {
63 memset(rr_dir->status + rr_dir->status_nr,
64 '\0', variant - rr_dir->status_nr);
65 rr_dir->status_nr = variant;
69 static void assign_variant(struct rerere_id *id)
71 int variant;
72 struct rerere_dir *rr_dir = id->collection;
74 variant = id->variant;
75 if (variant < 0) {
76 for (variant = 0; variant < rr_dir->status_nr; variant++)
77 if (!rr_dir->status[variant])
78 break;
80 fit_variant(rr_dir, variant);
81 id->variant = variant;
84 const char *rerere_path(const struct rerere_id *id, const char *file)
86 if (!file)
87 return git_path("rr-cache/%s", rerere_id_hex(id));
89 if (id->variant <= 0)
90 return git_path("rr-cache/%s/%s", rerere_id_hex(id), file);
92 return git_path("rr-cache/%s/%s.%d",
93 rerere_id_hex(id), file, id->variant);
96 static int is_rr_file(const char *name, const char *filename, int *variant)
98 const char *suffix;
99 char *ep;
101 if (!strcmp(name, filename)) {
102 *variant = 0;
103 return 1;
105 if (!skip_prefix(name, filename, &suffix) || *suffix != '.')
106 return 0;
108 errno = 0;
109 *variant = strtol(suffix + 1, &ep, 10);
110 if (errno || *ep)
111 return 0;
112 return 1;
115 static void scan_rerere_dir(struct rerere_dir *rr_dir)
117 struct dirent *de;
118 DIR *dir = opendir(git_path("rr-cache/%s", sha1_to_hex(rr_dir->hash)));
120 if (!dir)
121 return;
122 while ((de = readdir(dir)) != NULL) {
123 int variant;
125 if (is_rr_file(de->d_name, "postimage", &variant)) {
126 fit_variant(rr_dir, variant);
127 rr_dir->status[variant] |= RR_HAS_POSTIMAGE;
128 } else if (is_rr_file(de->d_name, "preimage", &variant)) {
129 fit_variant(rr_dir, variant);
130 rr_dir->status[variant] |= RR_HAS_PREIMAGE;
133 closedir(dir);
136 static const unsigned char *rerere_dir_hash(size_t i, void *table)
138 struct rerere_dir **rr_dir = table;
139 return rr_dir[i]->hash;
142 static struct rerere_dir *find_rerere_dir(const char *hex)
144 unsigned char hash[GIT_MAX_RAWSZ];
145 struct rerere_dir *rr_dir;
146 int pos;
148 if (get_sha1_hex(hex, hash))
149 return NULL; /* BUG */
150 pos = sha1_pos(hash, rerere_dir, rerere_dir_nr, rerere_dir_hash);
151 if (pos < 0) {
152 rr_dir = xmalloc(sizeof(*rr_dir));
153 hashcpy(rr_dir->hash, hash);
154 rr_dir->status = NULL;
155 rr_dir->status_nr = 0;
156 rr_dir->status_alloc = 0;
157 pos = -1 - pos;
159 /* Make sure the array is big enough ... */
160 ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc);
161 /* ... and add it in. */
162 rerere_dir_nr++;
163 MOVE_ARRAY(rerere_dir + pos + 1, rerere_dir + pos,
164 rerere_dir_nr - pos - 1);
165 rerere_dir[pos] = rr_dir;
166 scan_rerere_dir(rr_dir);
168 return rerere_dir[pos];
171 static int has_rerere_resolution(const struct rerere_id *id)
173 const int both = RR_HAS_POSTIMAGE|RR_HAS_PREIMAGE;
174 int variant = id->variant;
176 if (variant < 0)
177 return 0;
178 return ((id->collection->status[variant] & both) == both);
181 static struct rerere_id *new_rerere_id_hex(char *hex)
183 struct rerere_id *id = xmalloc(sizeof(*id));
184 id->collection = find_rerere_dir(hex);
185 id->variant = -1; /* not known yet */
186 return id;
189 static struct rerere_id *new_rerere_id(unsigned char *sha1)
191 return new_rerere_id_hex(sha1_to_hex(sha1));
195 * $GIT_DIR/MERGE_RR file is a collection of records, each of which is
196 * "conflict ID", a HT and pathname, terminated with a NUL, and is
197 * used to keep track of the set of paths that "rerere" may need to
198 * work on (i.e. what is left by the previous invocation of "git
199 * rerere" during the current conflict resolution session).
201 static void read_rr(struct repository *r, struct string_list *rr)
203 struct strbuf buf = STRBUF_INIT;
204 FILE *in = fopen_or_warn(git_path_merge_rr(r), "r");
206 if (!in)
207 return;
208 while (!strbuf_getwholeline(&buf, in, '\0')) {
209 char *path;
210 unsigned char hash[GIT_MAX_RAWSZ];
211 struct rerere_id *id;
212 int variant;
213 const unsigned hexsz = the_hash_algo->hexsz;
215 /* There has to be the hash, tab, path and then NUL */
216 if (buf.len < hexsz + 2 || get_sha1_hex(buf.buf, hash))
217 die(_("corrupt MERGE_RR"));
219 if (buf.buf[hexsz] != '.') {
220 variant = 0;
221 path = buf.buf + hexsz;
222 } else {
223 errno = 0;
224 variant = strtol(buf.buf + hexsz + 1, &path, 10);
225 if (errno)
226 die(_("corrupt MERGE_RR"));
228 if (*(path++) != '\t')
229 die(_("corrupt MERGE_RR"));
230 buf.buf[hexsz] = '\0';
231 id = new_rerere_id_hex(buf.buf);
232 id->variant = variant;
233 string_list_insert(rr, path)->util = id;
235 strbuf_release(&buf);
236 fclose(in);
239 static struct lock_file write_lock;
241 static int write_rr(struct string_list *rr, int out_fd)
243 int i;
244 for (i = 0; i < rr->nr; i++) {
245 struct strbuf buf = STRBUF_INIT;
246 struct rerere_id *id;
248 assert(rr->items[i].util != RERERE_RESOLVED);
250 id = rr->items[i].util;
251 if (!id)
252 continue;
253 assert(id->variant >= 0);
254 if (0 < id->variant)
255 strbuf_addf(&buf, "%s.%d\t%s%c",
256 rerere_id_hex(id), id->variant,
257 rr->items[i].string, 0);
258 else
259 strbuf_addf(&buf, "%s\t%s%c",
260 rerere_id_hex(id),
261 rr->items[i].string, 0);
263 if (write_in_full(out_fd, buf.buf, buf.len) < 0)
264 die(_("unable to write rerere record"));
266 strbuf_release(&buf);
268 if (commit_lock_file(&write_lock) != 0)
269 die(_("unable to write rerere record"));
270 return 0;
274 * "rerere" interacts with conflicted file contents using this I/O
275 * abstraction. It reads a conflicted contents from one place via
276 * "getline()" method, and optionally can write it out after
277 * normalizing the conflicted hunks to the "output". Subclasses of
278 * rerere_io embed this structure at the beginning of their own
279 * rerere_io object.
281 struct rerere_io {
282 int (*getline)(struct strbuf *, struct rerere_io *);
283 FILE *output;
284 int wrerror;
285 /* some more stuff */
288 static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
290 if (!count || *err)
291 return;
292 if (fwrite(p, count, 1, fp) != 1)
293 *err = errno;
296 static inline void ferr_puts(const char *s, FILE *fp, int *err)
298 ferr_write(s, strlen(s), fp, err);
301 static void rerere_io_putstr(const char *str, struct rerere_io *io)
303 if (io->output)
304 ferr_puts(str, io->output, &io->wrerror);
307 static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
309 if (io->output)
310 ferr_write(mem, sz, io->output, &io->wrerror);
314 * Subclass of rerere_io that reads from an on-disk file
316 struct rerere_io_file {
317 struct rerere_io io;
318 FILE *input;
322 * ... and its getline() method implementation
324 static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
326 struct rerere_io_file *io = (struct rerere_io_file *)io_;
327 return strbuf_getwholeline(sb, io->input, '\n');
331 * Require the exact number of conflict marker letters, no more, no
332 * less, followed by SP or any whitespace
333 * (including LF).
335 static int is_cmarker(char *buf, int marker_char, int marker_size)
337 int want_sp;
340 * The beginning of our version and the end of their version
341 * always are labeled like "<<<<< ours" or ">>>>> theirs",
342 * hence we set want_sp for them. Note that the version from
343 * the common ancestor in diff3-style output is not always
344 * labelled (e.g. "||||| common" is often seen but "|||||"
345 * alone is also valid), so we do not set want_sp.
347 want_sp = (marker_char == '<') || (marker_char == '>');
349 while (marker_size--)
350 if (*buf++ != marker_char)
351 return 0;
352 if (want_sp && *buf != ' ')
353 return 0;
354 return isspace(*buf);
357 static void rerere_strbuf_putconflict(struct strbuf *buf, int ch, size_t size)
359 strbuf_addchars(buf, ch, size);
360 strbuf_addch(buf, '\n');
363 static int handle_conflict(struct strbuf *out, struct rerere_io *io,
364 int marker_size, git_hash_ctx *ctx)
366 enum {
367 RR_SIDE_1 = 0, RR_SIDE_2, RR_ORIGINAL
368 } hunk = RR_SIDE_1;
369 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
370 struct strbuf buf = STRBUF_INIT, conflict = STRBUF_INIT;
371 int has_conflicts = -1;
373 while (!io->getline(&buf, io)) {
374 if (is_cmarker(buf.buf, '<', marker_size)) {
375 if (handle_conflict(&conflict, io, marker_size, NULL) < 0)
376 break;
377 if (hunk == RR_SIDE_1)
378 strbuf_addbuf(&one, &conflict);
379 else
380 strbuf_addbuf(&two, &conflict);
381 strbuf_release(&conflict);
382 } else if (is_cmarker(buf.buf, '|', marker_size)) {
383 if (hunk != RR_SIDE_1)
384 break;
385 hunk = RR_ORIGINAL;
386 } else if (is_cmarker(buf.buf, '=', marker_size)) {
387 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
388 break;
389 hunk = RR_SIDE_2;
390 } else if (is_cmarker(buf.buf, '>', marker_size)) {
391 if (hunk != RR_SIDE_2)
392 break;
393 if (strbuf_cmp(&one, &two) > 0)
394 strbuf_swap(&one, &two);
395 has_conflicts = 1;
396 rerere_strbuf_putconflict(out, '<', marker_size);
397 strbuf_addbuf(out, &one);
398 rerere_strbuf_putconflict(out, '=', marker_size);
399 strbuf_addbuf(out, &two);
400 rerere_strbuf_putconflict(out, '>', marker_size);
401 if (ctx) {
402 the_hash_algo->update_fn(ctx, one.buf ?
403 one.buf : "",
404 one.len + 1);
405 the_hash_algo->update_fn(ctx, two.buf ?
406 two.buf : "",
407 two.len + 1);
409 break;
410 } else if (hunk == RR_SIDE_1)
411 strbuf_addbuf(&one, &buf);
412 else if (hunk == RR_ORIGINAL)
413 ; /* discard */
414 else if (hunk == RR_SIDE_2)
415 strbuf_addbuf(&two, &buf);
417 strbuf_release(&one);
418 strbuf_release(&two);
419 strbuf_release(&buf);
421 return has_conflicts;
425 * Read contents a file with conflicts, normalize the conflicts
426 * by (1) discarding the common ancestor version in diff3-style,
427 * (2) reordering our side and their side so that whichever sorts
428 * alphabetically earlier comes before the other one, while
429 * computing the "conflict ID", which is just an SHA-1 hash of
430 * one side of the conflict, NUL, the other side of the conflict,
431 * and NUL concatenated together.
433 * Return 1 if conflict hunks are found, 0 if there are no conflict
434 * hunks and -1 if an error occured.
436 static int handle_path(unsigned char *hash, struct rerere_io *io, int marker_size)
438 git_hash_ctx ctx;
439 struct strbuf buf = STRBUF_INIT, out = STRBUF_INIT;
440 int has_conflicts = 0;
441 if (hash)
442 the_hash_algo->init_fn(&ctx);
444 while (!io->getline(&buf, io)) {
445 if (is_cmarker(buf.buf, '<', marker_size)) {
446 has_conflicts = handle_conflict(&out, io, marker_size,
447 hash ? &ctx : NULL);
448 if (has_conflicts < 0)
449 break;
450 rerere_io_putmem(out.buf, out.len, io);
451 strbuf_reset(&out);
452 } else
453 rerere_io_putstr(buf.buf, io);
455 strbuf_release(&buf);
456 strbuf_release(&out);
458 if (hash)
459 the_hash_algo->final_fn(hash, &ctx);
461 return has_conflicts;
465 * Scan the path for conflicts, do the "handle_path()" thing above, and
466 * return the number of conflict hunks found.
468 static int handle_file(struct index_state *istate,
469 const char *path, unsigned char *hash, const char *output)
471 int has_conflicts = 0;
472 struct rerere_io_file io;
473 int marker_size = ll_merge_marker_size(istate, path);
475 memset(&io, 0, sizeof(io));
476 io.io.getline = rerere_file_getline;
477 io.input = fopen(path, "r");
478 io.io.wrerror = 0;
479 if (!io.input)
480 return error_errno(_("could not open '%s'"), path);
482 if (output) {
483 io.io.output = fopen(output, "w");
484 if (!io.io.output) {
485 error_errno(_("could not write '%s'"), output);
486 fclose(io.input);
487 return -1;
491 has_conflicts = handle_path(hash, (struct rerere_io *)&io, marker_size);
493 fclose(io.input);
494 if (io.io.wrerror)
495 error(_("there were errors while writing '%s' (%s)"),
496 path, strerror(io.io.wrerror));
497 if (io.io.output && fclose(io.io.output))
498 io.io.wrerror = error_errno(_("failed to flush '%s'"), path);
500 if (has_conflicts < 0) {
501 if (output)
502 unlink_or_warn(output);
503 return error(_("could not parse conflict hunks in '%s'"), path);
505 if (io.io.wrerror)
506 return -1;
507 return has_conflicts;
511 * Look at a cache entry at "i" and see if it is not conflicting,
512 * conflicting and we are willing to handle, or conflicting and
513 * we are unable to handle, and return the determination in *type.
514 * Return the cache index to be looked at next, by skipping the
515 * stages we have already looked at in this invocation of this
516 * function.
518 static int check_one_conflict(struct index_state *istate, int i, int *type)
520 const struct cache_entry *e = istate->cache[i];
522 if (!ce_stage(e)) {
523 *type = RESOLVED;
524 return i + 1;
527 *type = PUNTED;
528 while (i < istate->cache_nr && ce_stage(istate->cache[i]) == 1)
529 i++;
531 /* Only handle regular files with both stages #2 and #3 */
532 if (i + 1 < istate->cache_nr) {
533 const struct cache_entry *e2 = istate->cache[i];
534 const struct cache_entry *e3 = istate->cache[i + 1];
535 if (ce_stage(e2) == 2 &&
536 ce_stage(e3) == 3 &&
537 ce_same_name(e, e3) &&
538 S_ISREG(e2->ce_mode) &&
539 S_ISREG(e3->ce_mode))
540 *type = THREE_STAGED;
543 /* Skip the entries with the same name */
544 while (i < istate->cache_nr && ce_same_name(e, istate->cache[i]))
545 i++;
546 return i;
550 * Scan the index and find paths that have conflicts that rerere can
551 * handle, i.e. the ones that has both stages #2 and #3.
553 * NEEDSWORK: we do not record or replay a previous "resolve by
554 * deletion" for a delete-modify conflict, as that is inherently risky
555 * without knowing what modification is being discarded. The only
556 * safe case, i.e. both side doing the deletion and modification that
557 * are identical to the previous round, might want to be handled,
558 * though.
560 static int find_conflict(struct repository *r, struct string_list *conflict)
562 int i;
564 if (read_index(r->index) < 0)
565 return error(_("index file corrupt"));
567 for (i = 0; i < r->index->cache_nr;) {
568 int conflict_type;
569 const struct cache_entry *e = r->index->cache[i];
570 i = check_one_conflict(r->index, i, &conflict_type);
571 if (conflict_type == THREE_STAGED)
572 string_list_insert(conflict, (const char *)e->name);
574 return 0;
578 * The merge_rr list is meant to hold outstanding conflicted paths
579 * that rerere could handle. Abuse the list by adding other types of
580 * entries to allow the caller to show "rerere remaining".
582 * - Conflicted paths that rerere does not handle are added
583 * - Conflicted paths that have been resolved are marked as such
584 * by storing RERERE_RESOLVED to .util field (where conflict ID
585 * is expected to be stored).
587 * Do *not* write MERGE_RR file out after calling this function.
589 * NEEDSWORK: we may want to fix the caller that implements "rerere
590 * remaining" to do this without abusing merge_rr.
592 int rerere_remaining(struct repository *r, struct string_list *merge_rr)
594 int i;
596 if (setup_rerere(r, merge_rr, RERERE_READONLY))
597 return 0;
598 if (read_index(r->index) < 0)
599 return error(_("index file corrupt"));
601 for (i = 0; i < r->index->cache_nr;) {
602 int conflict_type;
603 const struct cache_entry *e = r->index->cache[i];
604 i = check_one_conflict(r->index, i, &conflict_type);
605 if (conflict_type == PUNTED)
606 string_list_insert(merge_rr, (const char *)e->name);
607 else if (conflict_type == RESOLVED) {
608 struct string_list_item *it;
609 it = string_list_lookup(merge_rr, (const char *)e->name);
610 if (it != NULL) {
611 free_rerere_id(it);
612 it->util = RERERE_RESOLVED;
616 return 0;
620 * Try using the given conflict resolution "ID" to see
621 * if that recorded conflict resolves cleanly what we
622 * got in the "cur".
624 static int try_merge(struct index_state *istate,
625 const struct rerere_id *id, const char *path,
626 mmfile_t *cur, mmbuffer_t *result)
628 int ret;
629 mmfile_t base = {NULL, 0}, other = {NULL, 0};
631 if (read_mmfile(&base, rerere_path(id, "preimage")) ||
632 read_mmfile(&other, rerere_path(id, "postimage")))
633 ret = 1;
634 else
636 * A three-way merge. Note that this honors user-customizable
637 * low-level merge driver settings.
639 ret = ll_merge(result, path, &base, NULL, cur, "", &other, "",
640 istate, NULL);
642 free(base.ptr);
643 free(other.ptr);
645 return ret;
649 * Find the conflict identified by "id"; the change between its
650 * "preimage" (i.e. a previous contents with conflict markers) and its
651 * "postimage" (i.e. the corresponding contents with conflicts
652 * resolved) may apply cleanly to the contents stored in "path", i.e.
653 * the conflict this time around.
655 * Returns 0 for successful replay of recorded resolution, or non-zero
656 * for failure.
658 static int merge(struct index_state *istate, const struct rerere_id *id, const char *path)
660 FILE *f;
661 int ret;
662 mmfile_t cur = {NULL, 0};
663 mmbuffer_t result = {NULL, 0};
666 * Normalize the conflicts in path and write it out to
667 * "thisimage" temporary file.
669 if ((handle_file(istate, path, NULL, rerere_path(id, "thisimage")) < 0) ||
670 read_mmfile(&cur, rerere_path(id, "thisimage"))) {
671 ret = 1;
672 goto out;
675 ret = try_merge(istate, id, path, &cur, &result);
676 if (ret)
677 goto out;
680 * A successful replay of recorded resolution.
681 * Mark that "postimage" was used to help gc.
683 if (utime(rerere_path(id, "postimage"), NULL) < 0)
684 warning_errno(_("failed utime() on '%s'"),
685 rerere_path(id, "postimage"));
687 /* Update "path" with the resolution */
688 f = fopen(path, "w");
689 if (!f)
690 return error_errno(_("could not open '%s'"), path);
691 if (fwrite(result.ptr, result.size, 1, f) != 1)
692 error_errno(_("could not write '%s'"), path);
693 if (fclose(f))
694 return error_errno(_("writing '%s' failed"), path);
696 out:
697 free(cur.ptr);
698 free(result.ptr);
700 return ret;
703 static void update_paths(struct repository *r, struct string_list *update)
705 struct lock_file index_lock = LOCK_INIT;
706 int i;
708 hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
710 for (i = 0; i < update->nr; i++) {
711 struct string_list_item *item = &update->items[i];
712 if (add_file_to_index(r->index, item->string, 0))
713 exit(128);
714 fprintf_ln(stderr, _("Staged '%s' using previous resolution."),
715 item->string);
718 if (write_locked_index(r->index, &index_lock,
719 COMMIT_LOCK | SKIP_IF_UNCHANGED))
720 die(_("unable to write new index file"));
723 static void remove_variant(struct rerere_id *id)
725 unlink_or_warn(rerere_path(id, "postimage"));
726 unlink_or_warn(rerere_path(id, "preimage"));
727 id->collection->status[id->variant] = 0;
731 * The path indicated by rr_item may still have conflict for which we
732 * have a recorded resolution, in which case replay it and optionally
733 * update it. Or it may have been resolved by the user and we may
734 * only have the preimage for that conflict, in which case the result
735 * needs to be recorded as a resolution in a postimage file.
737 static void do_rerere_one_path(struct index_state *istate,
738 struct string_list_item *rr_item,
739 struct string_list *update)
741 const char *path = rr_item->string;
742 struct rerere_id *id = rr_item->util;
743 struct rerere_dir *rr_dir = id->collection;
744 int variant;
746 variant = id->variant;
748 /* Has the user resolved it already? */
749 if (variant >= 0) {
750 if (!handle_file(istate, path, NULL, NULL)) {
751 copy_file(rerere_path(id, "postimage"), path, 0666);
752 id->collection->status[variant] |= RR_HAS_POSTIMAGE;
753 fprintf_ln(stderr, _("Recorded resolution for '%s'."), path);
754 free_rerere_id(rr_item);
755 rr_item->util = NULL;
756 return;
759 * There may be other variants that can cleanly
760 * replay. Try them and update the variant number for
761 * this one.
765 /* Does any existing resolution apply cleanly? */
766 for (variant = 0; variant < rr_dir->status_nr; variant++) {
767 const int both = RR_HAS_PREIMAGE | RR_HAS_POSTIMAGE;
768 struct rerere_id vid = *id;
770 if ((rr_dir->status[variant] & both) != both)
771 continue;
773 vid.variant = variant;
774 if (merge(istate, &vid, path))
775 continue; /* failed to replay */
778 * If there already is a different variant that applies
779 * cleanly, there is no point maintaining our own variant.
781 if (0 <= id->variant && id->variant != variant)
782 remove_variant(id);
784 if (rerere_autoupdate)
785 string_list_insert(update, path);
786 else
787 fprintf_ln(stderr,
788 _("Resolved '%s' using previous resolution."),
789 path);
790 free_rerere_id(rr_item);
791 rr_item->util = NULL;
792 return;
795 /* None of the existing one applies; we need a new variant */
796 assign_variant(id);
798 variant = id->variant;
799 handle_file(istate, path, NULL, rerere_path(id, "preimage"));
800 if (id->collection->status[variant] & RR_HAS_POSTIMAGE) {
801 const char *path = rerere_path(id, "postimage");
802 if (unlink(path))
803 die_errno(_("cannot unlink stray '%s'"), path);
804 id->collection->status[variant] &= ~RR_HAS_POSTIMAGE;
806 id->collection->status[variant] |= RR_HAS_PREIMAGE;
807 fprintf_ln(stderr, _("Recorded preimage for '%s'"), path);
810 static int do_plain_rerere(struct repository *r,
811 struct string_list *rr, int fd)
813 struct string_list conflict = STRING_LIST_INIT_DUP;
814 struct string_list update = STRING_LIST_INIT_DUP;
815 int i;
817 find_conflict(r, &conflict);
820 * MERGE_RR records paths with conflicts immediately after
821 * merge failed. Some of the conflicted paths might have been
822 * hand resolved in the working tree since then, but the
823 * initial run would catch all and register their preimages.
825 for (i = 0; i < conflict.nr; i++) {
826 struct rerere_id *id;
827 unsigned char hash[GIT_MAX_RAWSZ];
828 const char *path = conflict.items[i].string;
829 int ret;
832 * Ask handle_file() to scan and assign a
833 * conflict ID. No need to write anything out
834 * yet.
836 ret = handle_file(r->index, path, hash, NULL);
837 if (ret != 0 && string_list_has_string(rr, path)) {
838 remove_variant(string_list_lookup(rr, path)->util);
839 string_list_remove(rr, path, 1);
841 if (ret < 1)
842 continue;
844 id = new_rerere_id(hash);
845 string_list_insert(rr, path)->util = id;
847 /* Ensure that the directory exists. */
848 mkdir_in_gitdir(rerere_path(id, NULL));
851 for (i = 0; i < rr->nr; i++)
852 do_rerere_one_path(r->index, &rr->items[i], &update);
854 if (update.nr)
855 update_paths(r, &update);
857 return write_rr(rr, fd);
860 static void git_rerere_config(void)
862 git_config_get_bool("rerere.enabled", &rerere_enabled);
863 git_config_get_bool("rerere.autoupdate", &rerere_autoupdate);
864 git_config(git_default_config, NULL);
867 static GIT_PATH_FUNC(git_path_rr_cache, "rr-cache")
869 static int is_rerere_enabled(void)
871 int rr_cache_exists;
873 if (!rerere_enabled)
874 return 0;
876 rr_cache_exists = is_directory(git_path_rr_cache());
877 if (rerere_enabled < 0)
878 return rr_cache_exists;
880 if (!rr_cache_exists && mkdir_in_gitdir(git_path_rr_cache()))
881 die(_("could not create directory '%s'"), git_path_rr_cache());
882 return 1;
885 int setup_rerere(struct repository *r, struct string_list *merge_rr, int flags)
887 int fd;
889 git_rerere_config();
890 if (!is_rerere_enabled())
891 return -1;
893 if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
894 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
895 if (flags & RERERE_READONLY)
896 fd = 0;
897 else
898 fd = hold_lock_file_for_update(&write_lock,
899 git_path_merge_rr(r),
900 LOCK_DIE_ON_ERROR);
901 read_rr(r, merge_rr);
902 return fd;
906 * The main entry point that is called internally from codepaths that
907 * perform mergy operations, possibly leaving conflicted index entries
908 * and working tree files.
910 int repo_rerere(struct repository *r, int flags)
912 struct string_list merge_rr = STRING_LIST_INIT_DUP;
913 int fd, status;
915 fd = setup_rerere(r, &merge_rr, flags);
916 if (fd < 0)
917 return 0;
918 status = do_plain_rerere(r, &merge_rr, fd);
919 free_rerere_dirs();
920 return status;
924 * Subclass of rerere_io that reads from an in-core buffer that is a
925 * strbuf
927 struct rerere_io_mem {
928 struct rerere_io io;
929 struct strbuf input;
933 * ... and its getline() method implementation
935 static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
937 struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
938 char *ep;
939 size_t len;
941 strbuf_release(sb);
942 if (!io->input.len)
943 return -1;
944 ep = memchr(io->input.buf, '\n', io->input.len);
945 if (!ep)
946 ep = io->input.buf + io->input.len;
947 else if (*ep == '\n')
948 ep++;
949 len = ep - io->input.buf;
950 strbuf_add(sb, io->input.buf, len);
951 strbuf_remove(&io->input, 0, len);
952 return 0;
955 static int handle_cache(struct index_state *istate,
956 const char *path, unsigned char *hash, const char *output)
958 mmfile_t mmfile[3] = {{NULL}};
959 mmbuffer_t result = {NULL, 0};
960 const struct cache_entry *ce;
961 int pos, len, i, has_conflicts;
962 struct rerere_io_mem io;
963 int marker_size = ll_merge_marker_size(istate, path);
966 * Reproduce the conflicted merge in-core
968 len = strlen(path);
969 pos = index_name_pos(istate, path, len);
970 if (0 <= pos)
971 return -1;
972 pos = -pos - 1;
974 while (pos < istate->cache_nr) {
975 enum object_type type;
976 unsigned long size;
978 ce = istate->cache[pos++];
979 if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
980 break;
981 i = ce_stage(ce) - 1;
982 if (!mmfile[i].ptr) {
983 mmfile[i].ptr = read_object_file(&ce->oid, &type,
984 &size);
985 mmfile[i].size = size;
988 for (i = 0; i < 3; i++)
989 if (!mmfile[i].ptr && !mmfile[i].size)
990 mmfile[i].ptr = xstrdup("");
993 * NEEDSWORK: handle conflicts from merges with
994 * merge.renormalize set, too?
996 ll_merge(&result, path, &mmfile[0], NULL,
997 &mmfile[1], "ours",
998 &mmfile[2], "theirs",
999 istate, NULL);
1000 for (i = 0; i < 3; i++)
1001 free(mmfile[i].ptr);
1003 memset(&io, 0, sizeof(io));
1004 io.io.getline = rerere_mem_getline;
1005 if (output)
1006 io.io.output = fopen(output, "w");
1007 else
1008 io.io.output = NULL;
1009 strbuf_init(&io.input, 0);
1010 strbuf_attach(&io.input, result.ptr, result.size, result.size);
1013 * Grab the conflict ID and optionally write the original
1014 * contents with conflict markers out.
1016 has_conflicts = handle_path(hash, (struct rerere_io *)&io, marker_size);
1017 strbuf_release(&io.input);
1018 if (io.io.output)
1019 fclose(io.io.output);
1020 return has_conflicts;
1023 static int rerere_forget_one_path(struct index_state *istate,
1024 const char *path,
1025 struct string_list *rr)
1027 const char *filename;
1028 struct rerere_id *id;
1029 unsigned char hash[GIT_MAX_RAWSZ];
1030 int ret;
1031 struct string_list_item *item;
1034 * Recreate the original conflict from the stages in the
1035 * index and compute the conflict ID
1037 ret = handle_cache(istate, path, hash, NULL);
1038 if (ret < 1)
1039 return error(_("could not parse conflict hunks in '%s'"), path);
1041 /* Nuke the recorded resolution for the conflict */
1042 id = new_rerere_id(hash);
1044 for (id->variant = 0;
1045 id->variant < id->collection->status_nr;
1046 id->variant++) {
1047 mmfile_t cur = { NULL, 0 };
1048 mmbuffer_t result = {NULL, 0};
1049 int cleanly_resolved;
1051 if (!has_rerere_resolution(id))
1052 continue;
1054 handle_cache(istate, path, hash, rerere_path(id, "thisimage"));
1055 if (read_mmfile(&cur, rerere_path(id, "thisimage"))) {
1056 free(cur.ptr);
1057 error(_("failed to update conflicted state in '%s'"), path);
1058 goto fail_exit;
1060 cleanly_resolved = !try_merge(istate, id, path, &cur, &result);
1061 free(result.ptr);
1062 free(cur.ptr);
1063 if (cleanly_resolved)
1064 break;
1067 if (id->collection->status_nr <= id->variant) {
1068 error(_("no remembered resolution for '%s'"), path);
1069 goto fail_exit;
1072 filename = rerere_path(id, "postimage");
1073 if (unlink(filename)) {
1074 if (errno == ENOENT)
1075 error(_("no remembered resolution for '%s'"), path);
1076 else
1077 error_errno(_("cannot unlink '%s'"), filename);
1078 goto fail_exit;
1082 * Update the preimage so that the user can resolve the
1083 * conflict in the working tree, run us again to record
1084 * the postimage.
1086 handle_cache(istate, path, hash, rerere_path(id, "preimage"));
1087 fprintf_ln(stderr, _("Updated preimage for '%s'"), path);
1090 * And remember that we can record resolution for this
1091 * conflict when the user is done.
1093 item = string_list_insert(rr, path);
1094 free_rerere_id(item);
1095 item->util = id;
1096 fprintf(stderr, _("Forgot resolution for '%s'\n"), path);
1097 return 0;
1099 fail_exit:
1100 free(id);
1101 return -1;
1104 int rerere_forget(struct repository *r, struct pathspec *pathspec)
1106 int i, fd;
1107 struct string_list conflict = STRING_LIST_INIT_DUP;
1108 struct string_list merge_rr = STRING_LIST_INIT_DUP;
1110 if (read_index(r->index) < 0)
1111 return error(_("index file corrupt"));
1113 fd = setup_rerere(r, &merge_rr, RERERE_NOAUTOUPDATE);
1114 if (fd < 0)
1115 return 0;
1118 * The paths may have been resolved (incorrectly);
1119 * recover the original conflicted state and then
1120 * find the conflicted paths.
1122 unmerge_index(r->index, pathspec);
1123 find_conflict(r, &conflict);
1124 for (i = 0; i < conflict.nr; i++) {
1125 struct string_list_item *it = &conflict.items[i];
1126 if (!match_pathspec(r->index, pathspec, it->string,
1127 strlen(it->string), 0, NULL, 0))
1128 continue;
1129 rerere_forget_one_path(r->index, it->string, &merge_rr);
1131 return write_rr(&merge_rr, fd);
1135 * Garbage collection support
1138 static timestamp_t rerere_created_at(struct rerere_id *id)
1140 struct stat st;
1142 return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
1145 static timestamp_t rerere_last_used_at(struct rerere_id *id)
1147 struct stat st;
1149 return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
1153 * Remove the recorded resolution for a given conflict ID
1155 static void unlink_rr_item(struct rerere_id *id)
1157 unlink_or_warn(rerere_path(id, "thisimage"));
1158 remove_variant(id);
1159 id->collection->status[id->variant] = 0;
1162 static void prune_one(struct rerere_id *id,
1163 timestamp_t cutoff_resolve, timestamp_t cutoff_noresolve)
1165 timestamp_t then;
1166 timestamp_t cutoff;
1168 then = rerere_last_used_at(id);
1169 if (then)
1170 cutoff = cutoff_resolve;
1171 else {
1172 then = rerere_created_at(id);
1173 if (!then)
1174 return;
1175 cutoff = cutoff_noresolve;
1177 if (then < cutoff)
1178 unlink_rr_item(id);
1181 void rerere_gc(struct repository *r, struct string_list *rr)
1183 struct string_list to_remove = STRING_LIST_INIT_DUP;
1184 DIR *dir;
1185 struct dirent *e;
1186 int i;
1187 timestamp_t now = time(NULL);
1188 timestamp_t cutoff_noresolve = now - 15 * 86400;
1189 timestamp_t cutoff_resolve = now - 60 * 86400;
1191 if (setup_rerere(r, rr, 0) < 0)
1192 return;
1194 git_config_get_expiry_in_days("gc.rerereresolved", &cutoff_resolve, now);
1195 git_config_get_expiry_in_days("gc.rerereunresolved", &cutoff_noresolve, now);
1196 git_config(git_default_config, NULL);
1197 dir = opendir(git_path("rr-cache"));
1198 if (!dir)
1199 die_errno(_("unable to open rr-cache directory"));
1200 /* Collect stale conflict IDs ... */
1201 while ((e = readdir(dir))) {
1202 struct rerere_dir *rr_dir;
1203 struct rerere_id id;
1204 int now_empty;
1206 if (is_dot_or_dotdot(e->d_name))
1207 continue;
1208 rr_dir = find_rerere_dir(e->d_name);
1209 if (!rr_dir)
1210 continue; /* or should we remove e->d_name? */
1212 now_empty = 1;
1213 for (id.variant = 0, id.collection = rr_dir;
1214 id.variant < id.collection->status_nr;
1215 id.variant++) {
1216 prune_one(&id, cutoff_resolve, cutoff_noresolve);
1217 if (id.collection->status[id.variant])
1218 now_empty = 0;
1220 if (now_empty)
1221 string_list_append(&to_remove, e->d_name);
1223 closedir(dir);
1225 /* ... and then remove the empty directories */
1226 for (i = 0; i < to_remove.nr; i++)
1227 rmdir(git_path("rr-cache/%s", to_remove.items[i].string));
1228 string_list_clear(&to_remove, 0);
1229 rollback_lock_file(&write_lock);
1233 * During a conflict resolution, after "rerere" recorded the
1234 * preimages, abandon them if the user did not resolve them or
1235 * record their resolutions. And drop $GIT_DIR/MERGE_RR.
1237 * NEEDSWORK: shouldn't we be calling this from "reset --hard"?
1239 void rerere_clear(struct repository *r, struct string_list *merge_rr)
1241 int i;
1243 if (setup_rerere(r, merge_rr, 0) < 0)
1244 return;
1246 for (i = 0; i < merge_rr->nr; i++) {
1247 struct rerere_id *id = merge_rr->items[i].util;
1248 if (!has_rerere_resolution(id)) {
1249 unlink_rr_item(id);
1250 rmdir(rerere_path(id, NULL));
1253 unlink_or_warn(git_path_merge_rr(r));
1254 rollback_lock_file(&write_lock);