1#include "cache.h" 2#include "lockfile.h" 3#include "string-list.h" 4#include "rerere.h" 5#include "xdiff-interface.h" 6#include "dir.h" 7#include "resolve-undo.h" 8#include "ll-merge.h" 9#include "attr.h" 10#include "pathspec.h" 11#include "sha1-lookup.h" 12 13#define RESOLVED 0 14#define PUNTED 1 15#define THREE_STAGED 2 16void *RERERE_RESOLVED = &RERERE_RESOLVED; 17 18/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */ 19static int rerere_enabled = -1; 20 21/* automatically update cleanly resolved paths to the index */ 22static int rerere_autoupdate; 23 24static char *merge_rr_path; 25 26static int rerere_dir_nr; 27static int rerere_dir_alloc; 28 29#define RR_HAS_POSTIMAGE 1 30#define RR_HAS_PREIMAGE 2 31static struct rerere_dir { 32 unsigned char sha1[20]; 33 unsigned char status; 34} **rerere_dir; 35 36static void free_rerere_dirs(void) 37{ 38 int i; 39 for (i = 0; i < rerere_dir_nr; i++) 40 free(rerere_dir[i]); 41 free(rerere_dir); 42 rerere_dir_nr = rerere_dir_alloc = 0; 43 rerere_dir = NULL; 44} 45 46static void free_rerere_id(struct string_list_item *item) 47{ 48 free(item->util); 49} 50 51static const char *rerere_id_hex(const struct rerere_id *id) 52{ 53 return sha1_to_hex(id->collection->sha1); 54} 55 56const char *rerere_path(const struct rerere_id *id, const char *file) 57{ 58 if (!file) 59 return git_path("rr-cache/%s", rerere_id_hex(id)); 60 61 return git_path("rr-cache/%s/%s", rerere_id_hex(id), file); 62} 63 64static int is_rr_file(const char *name, const char *filename) 65{ 66 return !strcmp(name, filename); 67} 68 69static void scan_rerere_dir(struct rerere_dir *rr_dir) 70{ 71 struct dirent *de; 72 DIR *dir = opendir(git_path("rr-cache/%s", sha1_to_hex(rr_dir->sha1))); 73 74 if (!dir) 75 return; 76 while ((de = readdir(dir)) != NULL) { 77 if (is_rr_file(de->d_name, "postimage")) 78 rr_dir->status |= RR_HAS_POSTIMAGE; 79 else if (is_rr_file(de->d_name, "preimage")) 80 rr_dir->status |= RR_HAS_PREIMAGE; 81 } 82 closedir(dir); 83} 84 85static const unsigned char *rerere_dir_sha1(size_t i, void *table) 86{ 87 struct rerere_dir **rr_dir = table; 88 return rr_dir[i]->sha1; 89} 90 91static struct rerere_dir *find_rerere_dir(const char *hex) 92{ 93 unsigned char sha1[20]; 94 struct rerere_dir *rr_dir; 95 int pos; 96 97 if (get_sha1_hex(hex, sha1)) 98 return NULL; /* BUG */ 99 pos = sha1_pos(sha1, rerere_dir, rerere_dir_nr, rerere_dir_sha1); 100 if (pos < 0) { 101 rr_dir = xmalloc(sizeof(*rr_dir)); 102 hashcpy(rr_dir->sha1, sha1); 103 rr_dir->status = 0; 104 pos = -1 - pos; 105 106 /* Make sure the array is big enough ... */ 107 ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc); 108 /* ... and add it in. */ 109 rerere_dir_nr++; 110 memmove(rerere_dir + pos + 1, rerere_dir + pos, 111 (rerere_dir_nr - pos - 1) * sizeof(*rerere_dir)); 112 rerere_dir[pos] = rr_dir; 113 scan_rerere_dir(rr_dir); 114 } 115 return rerere_dir[pos]; 116} 117 118static int has_rerere_resolution(const struct rerere_id *id) 119{ 120 return (id->collection->status & RR_HAS_POSTIMAGE); 121} 122 123static struct rerere_id *new_rerere_id_hex(char *hex) 124{ 125 struct rerere_id *id = xmalloc(sizeof(*id)); 126 id->collection = find_rerere_dir(hex); 127 return id; 128} 129 130static struct rerere_id *new_rerere_id(unsigned char *sha1) 131{ 132 return new_rerere_id_hex(sha1_to_hex(sha1)); 133} 134 135/* 136 * $GIT_DIR/MERGE_RR file is a collection of records, each of which is 137 * "conflict ID", a HT and pathname, terminated with a NUL, and is 138 * used to keep track of the set of paths that "rerere" may need to 139 * work on (i.e. what is left by the previous invocation of "git 140 * rerere" during the current conflict resolution session). 141 */ 142static void read_rr(struct string_list *rr) 143{ 144 struct strbuf buf = STRBUF_INIT; 145 FILE *in = fopen(merge_rr_path, "r"); 146 147 if (!in) 148 return; 149 while (!strbuf_getwholeline(&buf, in, '\0')) { 150 char *path; 151 unsigned char sha1[20]; 152 struct rerere_id *id; 153 154 /* There has to be the hash, tab, path and then NUL */ 155 if (buf.len < 42 || get_sha1_hex(buf.buf, sha1)) 156 die("corrupt MERGE_RR"); 157 158 if (buf.buf[40] != '\t') 159 die("corrupt MERGE_RR"); 160 buf.buf[40] = '\0'; 161 path = buf.buf + 41; 162 id = new_rerere_id_hex(buf.buf); 163 string_list_insert(rr, path)->util = id; 164 } 165 strbuf_release(&buf); 166 fclose(in); 167} 168 169static struct lock_file write_lock; 170 171static int write_rr(struct string_list *rr, int out_fd) 172{ 173 int i; 174 for (i = 0; i < rr->nr; i++) { 175 struct strbuf buf = STRBUF_INIT; 176 struct rerere_id *id; 177 178 assert(rr->items[i].util != RERERE_RESOLVED); 179 180 id = rr->items[i].util; 181 if (!id) 182 continue; 183 strbuf_addf(&buf, "%s\t%s%c", 184 rerere_id_hex(id), 185 rr->items[i].string, 0); 186 if (write_in_full(out_fd, buf.buf, buf.len) != buf.len) 187 die("unable to write rerere record"); 188 189 strbuf_release(&buf); 190 } 191 if (commit_lock_file(&write_lock) != 0) 192 die("unable to write rerere record"); 193 return 0; 194} 195 196/* 197 * "rerere" interacts with conflicted file contents using this I/O 198 * abstraction. It reads a conflicted contents from one place via 199 * "getline()" method, and optionally can write it out after 200 * normalizing the conflicted hunks to the "output". Subclasses of 201 * rerere_io embed this structure at the beginning of their own 202 * rerere_io object. 203 */ 204struct rerere_io { 205 int (*getline)(struct strbuf *, struct rerere_io *); 206 FILE *output; 207 int wrerror; 208 /* some more stuff */ 209}; 210 211static void ferr_write(const void *p, size_t count, FILE *fp, int *err) 212{ 213 if (!count || *err) 214 return; 215 if (fwrite(p, count, 1, fp) != 1) 216 *err = errno; 217} 218 219static inline void ferr_puts(const char *s, FILE *fp, int *err) 220{ 221 ferr_write(s, strlen(s), fp, err); 222} 223 224static void rerere_io_putstr(const char *str, struct rerere_io *io) 225{ 226 if (io->output) 227 ferr_puts(str, io->output, &io->wrerror); 228} 229 230/* 231 * Write a conflict marker to io->output (if defined). 232 */ 233static void rerere_io_putconflict(int ch, int size, struct rerere_io *io) 234{ 235 char buf[64]; 236 237 while (size) { 238 if (size <= sizeof(buf) - 2) { 239 memset(buf, ch, size); 240 buf[size] = '\n'; 241 buf[size + 1] = '\0'; 242 size = 0; 243 } else { 244 int sz = sizeof(buf) - 1; 245 246 /* 247 * Make sure we will not write everything out 248 * in this round by leaving at least 1 byte 249 * for the next round, giving the next round 250 * a chance to add the terminating LF. Yuck. 251 */ 252 if (size <= sz) 253 sz -= (sz - size) + 1; 254 memset(buf, ch, sz); 255 buf[sz] = '\0'; 256 size -= sz; 257 } 258 rerere_io_putstr(buf, io); 259 } 260} 261 262static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io) 263{ 264 if (io->output) 265 ferr_write(mem, sz, io->output, &io->wrerror); 266} 267 268/* 269 * Subclass of rerere_io that reads from an on-disk file 270 */ 271struct rerere_io_file { 272 struct rerere_io io; 273 FILE *input; 274}; 275 276/* 277 * ... and its getline() method implementation 278 */ 279static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_) 280{ 281 struct rerere_io_file *io = (struct rerere_io_file *)io_; 282 return strbuf_getwholeline(sb, io->input, '\n'); 283} 284 285/* 286 * Require the exact number of conflict marker letters, no more, no 287 * less, followed by SP or any whitespace 288 * (including LF). 289 */ 290static int is_cmarker(char *buf, int marker_char, int marker_size) 291{ 292 int want_sp; 293 294 /* 295 * The beginning of our version and the end of their version 296 * always are labeled like "<<<<< ours" or ">>>>> theirs", 297 * hence we set want_sp for them. Note that the version from 298 * the common ancestor in diff3-style output is not always 299 * labelled (e.g. "||||| common" is often seen but "|||||" 300 * alone is also valid), so we do not set want_sp. 301 */ 302 want_sp = (marker_char == '<') || (marker_char == '>'); 303 304 while (marker_size--) 305 if (*buf++ != marker_char) 306 return 0; 307 if (want_sp && *buf != ' ') 308 return 0; 309 return isspace(*buf); 310} 311 312/* 313 * Read contents a file with conflicts, normalize the conflicts 314 * by (1) discarding the common ancestor version in diff3-style, 315 * (2) reordering our side and their side so that whichever sorts 316 * alphabetically earlier comes before the other one, while 317 * computing the "conflict ID", which is just an SHA-1 hash of 318 * one side of the conflict, NUL, the other side of the conflict, 319 * and NUL concatenated together. 320 * 321 * Return the number of conflict hunks found. 322 * 323 * NEEDSWORK: the logic and theory of operation behind this conflict 324 * normalization may deserve to be documented somewhere, perhaps in 325 * Documentation/technical/rerere.txt. 326 */ 327static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size) 328{ 329 git_SHA_CTX ctx; 330 int hunk_no = 0; 331 enum { 332 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL 333 } hunk = RR_CONTEXT; 334 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT; 335 struct strbuf buf = STRBUF_INIT; 336 337 if (sha1) 338 git_SHA1_Init(&ctx); 339 340 while (!io->getline(&buf, io)) { 341 if (is_cmarker(buf.buf, '<', marker_size)) { 342 if (hunk != RR_CONTEXT) 343 goto bad; 344 hunk = RR_SIDE_1; 345 } else if (is_cmarker(buf.buf, '|', marker_size)) { 346 if (hunk != RR_SIDE_1) 347 goto bad; 348 hunk = RR_ORIGINAL; 349 } else if (is_cmarker(buf.buf, '=', marker_size)) { 350 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL) 351 goto bad; 352 hunk = RR_SIDE_2; 353 } else if (is_cmarker(buf.buf, '>', marker_size)) { 354 if (hunk != RR_SIDE_2) 355 goto bad; 356 if (strbuf_cmp(&one, &two) > 0) 357 strbuf_swap(&one, &two); 358 hunk_no++; 359 hunk = RR_CONTEXT; 360 rerere_io_putconflict('<', marker_size, io); 361 rerere_io_putmem(one.buf, one.len, io); 362 rerere_io_putconflict('=', marker_size, io); 363 rerere_io_putmem(two.buf, two.len, io); 364 rerere_io_putconflict('>', marker_size, io); 365 if (sha1) { 366 git_SHA1_Update(&ctx, one.buf ? one.buf : "", 367 one.len + 1); 368 git_SHA1_Update(&ctx, two.buf ? two.buf : "", 369 two.len + 1); 370 } 371 strbuf_reset(&one); 372 strbuf_reset(&two); 373 } else if (hunk == RR_SIDE_1) 374 strbuf_addbuf(&one, &buf); 375 else if (hunk == RR_ORIGINAL) 376 ; /* discard */ 377 else if (hunk == RR_SIDE_2) 378 strbuf_addbuf(&two, &buf); 379 else 380 rerere_io_putstr(buf.buf, io); 381 continue; 382 bad: 383 hunk = 99; /* force error exit */ 384 break; 385 } 386 strbuf_release(&one); 387 strbuf_release(&two); 388 strbuf_release(&buf); 389 390 if (sha1) 391 git_SHA1_Final(sha1, &ctx); 392 if (hunk != RR_CONTEXT) 393 return -1; 394 return hunk_no; 395} 396 397/* 398 * Scan the path for conflicts, do the "handle_path()" thing above, and 399 * return the number of conflict hunks found. 400 */ 401static int handle_file(const char *path, unsigned char *sha1, const char *output) 402{ 403 int hunk_no = 0; 404 struct rerere_io_file io; 405 int marker_size = ll_merge_marker_size(path); 406 407 memset(&io, 0, sizeof(io)); 408 io.io.getline = rerere_file_getline; 409 io.input = fopen(path, "r"); 410 io.io.wrerror = 0; 411 if (!io.input) 412 return error("Could not open %s", path); 413 414 if (output) { 415 io.io.output = fopen(output, "w"); 416 if (!io.io.output) { 417 fclose(io.input); 418 return error("Could not write %s", output); 419 } 420 } 421 422 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size); 423 424 fclose(io.input); 425 if (io.io.wrerror) 426 error("There were errors while writing %s (%s)", 427 path, strerror(io.io.wrerror)); 428 if (io.io.output && fclose(io.io.output)) 429 io.io.wrerror = error("Failed to flush %s: %s", 430 path, strerror(errno)); 431 432 if (hunk_no < 0) { 433 if (output) 434 unlink_or_warn(output); 435 return error("Could not parse conflict hunks in %s", path); 436 } 437 if (io.io.wrerror) 438 return -1; 439 return hunk_no; 440} 441 442/* 443 * Subclass of rerere_io that reads from an in-core buffer that is a 444 * strbuf 445 */ 446struct rerere_io_mem { 447 struct rerere_io io; 448 struct strbuf input; 449}; 450 451/* 452 * ... and its getline() method implementation 453 */ 454static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_) 455{ 456 struct rerere_io_mem *io = (struct rerere_io_mem *)io_; 457 char *ep; 458 size_t len; 459 460 strbuf_release(sb); 461 if (!io->input.len) 462 return -1; 463 ep = memchr(io->input.buf, '\n', io->input.len); 464 if (!ep) 465 ep = io->input.buf + io->input.len; 466 else if (*ep == '\n') 467 ep++; 468 len = ep - io->input.buf; 469 strbuf_add(sb, io->input.buf, len); 470 strbuf_remove(&io->input, 0, len); 471 return 0; 472} 473 474static int handle_cache(const char *path, unsigned char *sha1, const char *output) 475{ 476 mmfile_t mmfile[3] = {{NULL}}; 477 mmbuffer_t result = {NULL, 0}; 478 const struct cache_entry *ce; 479 int pos, len, i, hunk_no; 480 struct rerere_io_mem io; 481 int marker_size = ll_merge_marker_size(path); 482 483 /* 484 * Reproduce the conflicted merge in-core 485 */ 486 len = strlen(path); 487 pos = cache_name_pos(path, len); 488 if (0 <= pos) 489 return -1; 490 pos = -pos - 1; 491 492 while (pos < active_nr) { 493 enum object_type type; 494 unsigned long size; 495 496 ce = active_cache[pos++]; 497 if (ce_namelen(ce) != len || memcmp(ce->name, path, len)) 498 break; 499 i = ce_stage(ce) - 1; 500 if (!mmfile[i].ptr) { 501 mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size); 502 mmfile[i].size = size; 503 } 504 } 505 for (i = 0; i < 3; i++) 506 if (!mmfile[i].ptr && !mmfile[i].size) 507 mmfile[i].ptr = xstrdup(""); 508 509 /* 510 * NEEDSWORK: handle conflicts from merges with 511 * merge.renormalize set, too 512 */ 513 ll_merge(&result, path, &mmfile[0], NULL, 514 &mmfile[1], "ours", 515 &mmfile[2], "theirs", NULL); 516 for (i = 0; i < 3; i++) 517 free(mmfile[i].ptr); 518 519 memset(&io, 0, sizeof(io)); 520 io.io.getline = rerere_mem_getline; 521 if (output) 522 io.io.output = fopen(output, "w"); 523 else 524 io.io.output = NULL; 525 strbuf_init(&io.input, 0); 526 strbuf_attach(&io.input, result.ptr, result.size, result.size); 527 528 /* 529 * Grab the conflict ID and optionally write the original 530 * contents with conflict markers out. 531 */ 532 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size); 533 strbuf_release(&io.input); 534 if (io.io.output) 535 fclose(io.io.output); 536 return hunk_no; 537} 538 539/* 540 * Look at a cache entry at "i" and see if it is not conflicting, 541 * conflicting and we are willing to handle, or conflicting and 542 * we are unable to handle, and return the determination in *type. 543 * Return the cache index to be looked at next, by skipping the 544 * stages we have already looked at in this invocation of this 545 * function. 546 */ 547static int check_one_conflict(int i, int *type) 548{ 549 const struct cache_entry *e = active_cache[i]; 550 551 if (!ce_stage(e)) { 552 *type = RESOLVED; 553 return i + 1; 554 } 555 556 *type = PUNTED; 557 while (ce_stage(active_cache[i]) == 1) 558 i++; 559 560 /* Only handle regular files with both stages #2 and #3 */ 561 if (i + 1 < active_nr) { 562 const struct cache_entry *e2 = active_cache[i]; 563 const struct cache_entry *e3 = active_cache[i + 1]; 564 if (ce_stage(e2) == 2 && 565 ce_stage(e3) == 3 && 566 ce_same_name(e, e3) && 567 S_ISREG(e2->ce_mode) && 568 S_ISREG(e3->ce_mode)) 569 *type = THREE_STAGED; 570 } 571 572 /* Skip the entries with the same name */ 573 while (i < active_nr && ce_same_name(e, active_cache[i])) 574 i++; 575 return i; 576} 577 578/* 579 * Scan the index and find paths that have conflicts that rerere can 580 * handle, i.e. the ones that has both stages #2 and #3. 581 * 582 * NEEDSWORK: we do not record or replay a previous "resolve by 583 * deletion" for a delete-modify conflict, as that is inherently risky 584 * without knowing what modification is being discarded. The only 585 * safe case, i.e. both side doing the deletion and modification that 586 * are identical to the previous round, might want to be handled, 587 * though. 588 */ 589static int find_conflict(struct string_list *conflict) 590{ 591 int i; 592 if (read_cache() < 0) 593 return error("Could not read index"); 594 595 for (i = 0; i < active_nr;) { 596 int conflict_type; 597 const struct cache_entry *e = active_cache[i]; 598 i = check_one_conflict(i, &conflict_type); 599 if (conflict_type == THREE_STAGED) 600 string_list_insert(conflict, (const char *)e->name); 601 } 602 return 0; 603} 604 605/* 606 * The merge_rr list is meant to hold outstanding conflicted paths 607 * that rerere could handle. Abuse the list by adding other types of 608 * entries to allow the caller to show "rerere remaining". 609 * 610 * - Conflicted paths that rerere does not handle are added 611 * - Conflicted paths that have been resolved are marked as such 612 * by storing RERERE_RESOLVED to .util field (where conflict ID 613 * is expected to be stored). 614 * 615 * Do *not* write MERGE_RR file out after calling this function. 616 * 617 * NEEDSWORK: we may want to fix the caller that implements "rerere 618 * remaining" to do this without abusing merge_rr. 619 */ 620int rerere_remaining(struct string_list *merge_rr) 621{ 622 int i; 623 if (read_cache() < 0) 624 return error("Could not read index"); 625 626 for (i = 0; i < active_nr;) { 627 int conflict_type; 628 const struct cache_entry *e = active_cache[i]; 629 i = check_one_conflict(i, &conflict_type); 630 if (conflict_type == PUNTED) 631 string_list_insert(merge_rr, (const char *)e->name); 632 else if (conflict_type == RESOLVED) { 633 struct string_list_item *it; 634 it = string_list_lookup(merge_rr, (const char *)e->name); 635 if (it != NULL) { 636 free_rerere_id(it); 637 it->util = RERERE_RESOLVED; 638 } 639 } 640 } 641 return 0; 642} 643 644/* 645 * Find the conflict identified by "id"; the change between its 646 * "preimage" (i.e. a previous contents with conflict markers) and its 647 * "postimage" (i.e. the corresponding contents with conflicts 648 * resolved) may apply cleanly to the contents stored in "path", i.e. 649 * the conflict this time around. 650 * 651 * Returns 0 for successful replay of recorded resolution, or non-zero 652 * for failure. 653 */ 654static int merge(const struct rerere_id *id, const char *path) 655{ 656 FILE *f; 657 int ret; 658 mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0}; 659 mmbuffer_t result = {NULL, 0}; 660 661 /* 662 * Normalize the conflicts in path and write it out to 663 * "thisimage" temporary file. 664 */ 665 if (handle_file(path, NULL, rerere_path(id, "thisimage")) < 0) { 666 ret = 1; 667 goto out; 668 } 669 670 if (read_mmfile(&cur, rerere_path(id, "thisimage")) || 671 read_mmfile(&base, rerere_path(id, "preimage")) || 672 read_mmfile(&other, rerere_path(id, "postimage"))) { 673 ret = 1; 674 goto out; 675 } 676 677 /* 678 * A three-way merge. Note that this honors user-customizable 679 * low-level merge driver settings. 680 */ 681 ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL); 682 if (ret) 683 goto out; 684 685 /* 686 * A successful replay of recorded resolution. 687 * Mark that "postimage" was used to help gc. 688 */ 689 if (utime(rerere_path(id, "postimage"), NULL) < 0) 690 warning("failed utime() on %s: %s", 691 rerere_path(id, "postimage"), 692 strerror(errno)); 693 694 /* Update "path" with the resolution */ 695 f = fopen(path, "w"); 696 if (!f) 697 return error("Could not open %s: %s", path, 698 strerror(errno)); 699 if (fwrite(result.ptr, result.size, 1, f) != 1) 700 error("Could not write %s: %s", path, strerror(errno)); 701 if (fclose(f)) 702 return error("Writing %s failed: %s", path, 703 strerror(errno)); 704 705out: 706 free(cur.ptr); 707 free(base.ptr); 708 free(other.ptr); 709 free(result.ptr); 710 711 return ret; 712} 713 714static struct lock_file index_lock; 715 716static void update_paths(struct string_list *update) 717{ 718 int i; 719 720 hold_locked_index(&index_lock, 1); 721 722 for (i = 0; i < update->nr; i++) { 723 struct string_list_item *item = &update->items[i]; 724 if (add_file_to_cache(item->string, 0)) 725 exit(128); 726 fprintf(stderr, "Staged '%s' using previous resolution.\n", 727 item->string); 728 } 729 730 if (active_cache_changed) { 731 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) 732 die("Unable to write new index file"); 733 } else 734 rollback_lock_file(&index_lock); 735} 736 737/* 738 * The path indicated by rr_item may still have conflict for which we 739 * have a recorded resolution, in which case replay it and optionally 740 * update it. Or it may have been resolved by the user and we may 741 * only have the preimage for that conflict, in which case the result 742 * needs to be recorded as a resolution in a postimage file. 743 */ 744static void do_rerere_one_path(struct string_list_item *rr_item, 745 struct string_list *update) 746{ 747 const char *path = rr_item->string; 748 const struct rerere_id *id = rr_item->util; 749 750 /* Is there a recorded resolution we could attempt to apply? */ 751 if (has_rerere_resolution(id)) { 752 if (merge(id, path)) 753 return; /* failed to replay */ 754 755 if (rerere_autoupdate) 756 string_list_insert(update, path); 757 else 758 fprintf(stderr, 759 "Resolved '%s' using previous resolution.\n", 760 path); 761 } else if (!handle_file(path, NULL, NULL)) { 762 /* The user has resolved it. */ 763 copy_file(rerere_path(id, "postimage"), path, 0666); 764 id->collection->status |= RR_HAS_POSTIMAGE; 765 fprintf(stderr, "Recorded resolution for '%s'.\n", path); 766 } else { 767 return; 768 } 769 free_rerere_id(rr_item); 770 rr_item->util = NULL; 771} 772 773static int do_plain_rerere(struct string_list *rr, int fd) 774{ 775 struct string_list conflict = STRING_LIST_INIT_DUP; 776 struct string_list update = STRING_LIST_INIT_DUP; 777 int i; 778 779 find_conflict(&conflict); 780 781 /* 782 * MERGE_RR records paths with conflicts immediately after 783 * merge failed. Some of the conflicted paths might have been 784 * hand resolved in the working tree since then, but the 785 * initial run would catch all and register their preimages. 786 */ 787 for (i = 0; i < conflict.nr; i++) { 788 struct rerere_id *id; 789 unsigned char sha1[20]; 790 const char *path = conflict.items[i].string; 791 int ret; 792 793 if (string_list_has_string(rr, path)) 794 continue; 795 796 /* 797 * Ask handle_file() to scan and assign a 798 * conflict ID. No need to write anything out 799 * yet. 800 */ 801 ret = handle_file(path, sha1, NULL); 802 if (ret < 1) 803 continue; 804 805 id = new_rerere_id(sha1); 806 string_list_insert(rr, path)->util = id; 807 808 /* 809 * If the directory does not exist, create 810 * it. mkdir_in_gitdir() will fail with 811 * EEXIST if there already is one. 812 * 813 * NEEDSWORK: make sure "gc" does not remove 814 * preimage without removing the directory. 815 */ 816 if (mkdir_in_gitdir(rerere_path(id, NULL))) 817 continue; 818 819 /* 820 * We are the first to encounter this 821 * conflict. Ask handle_file() to write the 822 * normalized contents to the "preimage" file. 823 */ 824 handle_file(path, NULL, rerere_path(id, "preimage")); 825 id->collection->status |= RR_HAS_PREIMAGE; 826 fprintf(stderr, "Recorded preimage for '%s'\n", path); 827 } 828 829 for (i = 0; i < rr->nr; i++) 830 do_rerere_one_path(&rr->items[i], &update); 831 832 if (update.nr) 833 update_paths(&update); 834 835 return write_rr(rr, fd); 836} 837 838static void git_rerere_config(void) 839{ 840 git_config_get_bool("rerere.enabled", &rerere_enabled); 841 git_config_get_bool("rerere.autoupdate", &rerere_autoupdate); 842 git_config(git_default_config, NULL); 843} 844 845static int is_rerere_enabled(void) 846{ 847 const char *rr_cache; 848 int rr_cache_exists; 849 850 if (!rerere_enabled) 851 return 0; 852 853 rr_cache = git_path("rr-cache"); 854 rr_cache_exists = is_directory(rr_cache); 855 if (rerere_enabled < 0) 856 return rr_cache_exists; 857 858 if (!rr_cache_exists && mkdir_in_gitdir(rr_cache)) 859 die("Could not create directory %s", rr_cache); 860 return 1; 861} 862 863int setup_rerere(struct string_list *merge_rr, int flags) 864{ 865 int fd; 866 867 git_rerere_config(); 868 if (!is_rerere_enabled()) 869 return -1; 870 871 if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE)) 872 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE); 873 merge_rr_path = git_pathdup("MERGE_RR"); 874 fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 875 LOCK_DIE_ON_ERROR); 876 read_rr(merge_rr); 877 return fd; 878} 879 880/* 881 * The main entry point that is called internally from codepaths that 882 * perform mergy operations, possibly leaving conflicted index entries 883 * and working tree files. 884 */ 885int rerere(int flags) 886{ 887 struct string_list merge_rr = STRING_LIST_INIT_DUP; 888 int fd, status; 889 890 fd = setup_rerere(&merge_rr, flags); 891 if (fd < 0) 892 return 0; 893 status = do_plain_rerere(&merge_rr, fd); 894 free_rerere_dirs(); 895 return status; 896} 897 898static int rerere_forget_one_path(const char *path, struct string_list *rr) 899{ 900 const char *filename; 901 struct rerere_id *id; 902 unsigned char sha1[20]; 903 int ret; 904 struct string_list_item *item; 905 906 /* 907 * Recreate the original conflict from the stages in the 908 * index and compute the conflict ID 909 */ 910 ret = handle_cache(path, sha1, NULL); 911 if (ret < 1) 912 return error("Could not parse conflict hunks in '%s'", path); 913 914 /* Nuke the recorded resolution for the conflict */ 915 id = new_rerere_id(sha1); 916 filename = rerere_path(id, "postimage"); 917 if (unlink(filename)) 918 return (errno == ENOENT 919 ? error("no remembered resolution for %s", path) 920 : error("cannot unlink %s: %s", filename, strerror(errno))); 921 922 /* 923 * Update the preimage so that the user can resolve the 924 * conflict in the working tree, run us again to record 925 * the postimage. 926 */ 927 handle_cache(path, sha1, rerere_path(id, "preimage")); 928 fprintf(stderr, "Updated preimage for '%s'\n", path); 929 930 /* 931 * And remember that we can record resolution for this 932 * conflict when the user is done. 933 */ 934 item = string_list_insert(rr, path); 935 free_rerere_id(item); 936 item->util = id; 937 fprintf(stderr, "Forgot resolution for %s\n", path); 938 return 0; 939} 940 941int rerere_forget(struct pathspec *pathspec) 942{ 943 int i, fd; 944 struct string_list conflict = STRING_LIST_INIT_DUP; 945 struct string_list merge_rr = STRING_LIST_INIT_DUP; 946 947 if (read_cache() < 0) 948 return error("Could not read index"); 949 950 fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE); 951 952 /* 953 * The paths may have been resolved (incorrectly); 954 * recover the original conflicted state and then 955 * find the conflicted paths. 956 */ 957 unmerge_cache(pathspec); 958 find_conflict(&conflict); 959 for (i = 0; i < conflict.nr; i++) { 960 struct string_list_item *it = &conflict.items[i]; 961 if (!match_pathspec(pathspec, it->string, 962 strlen(it->string), 0, NULL, 0)) 963 continue; 964 rerere_forget_one_path(it->string, &merge_rr); 965 } 966 return write_rr(&merge_rr, fd); 967} 968 969/* 970 * Garbage collection support 971 */ 972 973/* 974 * Note that this is not reentrant but is used only one-at-a-time 975 * so it does not matter right now. 976 */ 977static struct rerere_id *dirname_to_id(const char *name) 978{ 979 static struct rerere_id id; 980 id.collection = find_rerere_dir(name); 981 return &id; 982} 983 984static time_t rerere_created_at(const char *dir_name) 985{ 986 struct stat st; 987 struct rerere_id *id = dirname_to_id(dir_name); 988 989 return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime; 990} 991 992static time_t rerere_last_used_at(const char *dir_name) 993{ 994 struct stat st; 995 struct rerere_id *id = dirname_to_id(dir_name); 996 997 return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime; 998} 9991000/*1001 * Remove the recorded resolution for a given conflict ID1002 */1003static void unlink_rr_item(struct rerere_id *id)1004{1005 unlink(rerere_path(id, "thisimage"));1006 unlink(rerere_path(id, "preimage"));1007 unlink(rerere_path(id, "postimage"));1008 /*1009 * NEEDSWORK: what if this rmdir() fails? Wouldn't we then1010 * assume that we already have preimage recorded in1011 * do_plain_rerere()?1012 */1013 rmdir(rerere_path(id, NULL));1014}10151016void rerere_gc(struct string_list *rr)1017{1018 struct string_list to_remove = STRING_LIST_INIT_DUP;1019 DIR *dir;1020 struct dirent *e;1021 int i, cutoff;1022 time_t now = time(NULL), then;1023 int cutoff_noresolve = 15;1024 int cutoff_resolve = 60;10251026 git_config_get_int("gc.rerereresolved", &cutoff_resolve);1027 git_config_get_int("gc.rerereunresolved", &cutoff_noresolve);1028 git_config(git_default_config, NULL);1029 dir = opendir(git_path("rr-cache"));1030 if (!dir)1031 die_errno("unable to open rr-cache directory");1032 /* Collect stale conflict IDs ... */1033 while ((e = readdir(dir))) {1034 if (is_dot_or_dotdot(e->d_name))1035 continue;10361037 then = rerere_last_used_at(e->d_name);1038 if (then) {1039 cutoff = cutoff_resolve;1040 } else {1041 then = rerere_created_at(e->d_name);1042 if (!then)1043 continue;1044 cutoff = cutoff_noresolve;1045 }1046 if (then < now - cutoff * 86400)1047 string_list_append(&to_remove, e->d_name);1048 }1049 closedir(dir);1050 /* ... and then remove them one-by-one */1051 for (i = 0; i < to_remove.nr; i++)1052 unlink_rr_item(dirname_to_id(to_remove.items[i].string));1053 string_list_clear(&to_remove, 0);1054}10551056/*1057 * During a conflict resolution, after "rerere" recorded the1058 * preimages, abandon them if the user did not resolve them or1059 * record their resolutions. And drop $GIT_DIR/MERGE_RR.1060 *1061 * NEEDSWORK: shouldn't we be calling this from "reset --hard"?1062 */1063void rerere_clear(struct string_list *merge_rr)1064{1065 int i;10661067 for (i = 0; i < merge_rr->nr; i++) {1068 struct rerere_id *id = merge_rr->items[i].util;1069 if (!has_rerere_resolution(id))1070 unlink_rr_item(id);1071 }1072 unlink_or_warn(git_path("MERGE_RR"));1073}