git.oblomov.eu Git - git/blob - builtin/bisect--helper.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "parse-options.h"
   4 #include "bisect.h"
   5 #include "refs.h"
   6 #include "dir.h"
   7 #include "strvec.h"
   8 #include "run-command.h"
   9 #include "prompt.h"
  10 #include "quote.h"
  11 #include "revision.h"
  12
  13 static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
  14 static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV")
  15 static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK")
  16 static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
  17 static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
  18 static GIT_PATH_FUNC(git_path_head_name, "head-name")
  19 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
  20 static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
  21
  22 static const char * const git_bisect_helper_usage[] = {
  23         N_("git bisect--helper --bisect-reset [<commit>]"),
  24         N_("git bisect--helper --bisect-next-check <good_term> <bad_term> [<term>]"),
  25         N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"),
  26         N_("git bisect--helper --bisect-start [--term-{new,bad}=<term> --term-{old,good}=<term>]"
  27                                             " [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]"),
  28         N_("git bisect--helper --bisect-next"),
  29         N_("git bisect--helper --bisect-state (bad|new) [<rev>]"),
  30         N_("git bisect--helper --bisect-state (good|old) [<rev>...]"),
  31         N_("git bisect--helper --bisect-replay <filename>"),
  32         N_("git bisect--helper --bisect-skip [(<rev>|<range>)...]"),
  33         NULL
  34 };
  35
  36 struct add_bisect_ref_data {
  37         struct rev_info *revs;
  38         unsigned int object_flags;
  39 };
  40
  41 struct bisect_terms {
  42         char *term_good;
  43         char *term_bad;
  44 };
  45
  46 static void free_terms(struct bisect_terms *terms)
  47 {
  48         FREE_AND_NULL(terms->term_good);
  49         FREE_AND_NULL(terms->term_bad);
  50 }
  51
  52 static void set_terms(struct bisect_terms *terms, const char *bad,
  53                       const char *good)
  54 {
  55         free((void *)terms->term_good);
  56         terms->term_good = xstrdup(good);
  57         free((void *)terms->term_bad);
  58         terms->term_bad = xstrdup(bad);
  59 }
  60
  61 static const char vocab_bad[] = "bad|new";
  62 static const char vocab_good[] = "good|old";
  63
  64 static int bisect_autostart(struct bisect_terms *terms);
  65
  66 /*
  67  * Check whether the string `term` belongs to the set of strings
  68  * included in the variable arguments.
  69  */
  70 LAST_ARG_MUST_BE_NULL
  71 static int one_of(const char *term, ...)
  72 {
  73         int res = 0;
  74         va_list matches;
  75         const char *match;
  76
  77         va_start(matches, term);
  78         while (!res && (match = va_arg(matches, const char *)))
  79                 res = !strcmp(term, match);
  80         va_end(matches);
  81
  82         return res;
  83 }
  84
  85 /*
  86  * return code BISECT_INTERNAL_SUCCESS_MERGE_BASE
  87  * and BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND are codes
  88  * that indicate special success.
  89  */
  90
  91 static int is_bisect_success(enum bisect_error res)
  92 {
  93         return !res ||
  94                 res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND ||
  95                 res == BISECT_INTERNAL_SUCCESS_MERGE_BASE;
  96 }
  97
  98 static int write_in_file(const char *path, const char *mode, const char *format, va_list args)
  99 {
 100         FILE *fp = NULL;
 101         int res = 0;
 102
 103         if (strcmp(mode, "w") && strcmp(mode, "a"))
 104                 BUG("write-in-file does not support '%s' mode", mode);
 105         fp = fopen(path, mode);
 106         if (!fp)
 107                 return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
 108         res = vfprintf(fp, format, args);
 109
 110         if (res < 0) {
 111                 int saved_errno = errno;
 112                 fclose(fp);
 113                 errno = saved_errno;
 114                 return error_errno(_("could not write to file '%s'"), path);
 115         }
 116
 117         return fclose(fp);
 118 }
 119
 120 static int write_to_file(const char *path, const char *format, ...)
 121 {
 122         int res;
 123         va_list args;
 124
 125         va_start(args, format);
 126         res = write_in_file(path, "w", format, args);
 127         va_end(args);
 128
 129         return res;
 130 }
 131
 132 static int append_to_file(const char *path, const char *format, ...)
 133 {
 134         int res;
 135         va_list args;
 136
 137         va_start(args, format);
 138         res = write_in_file(path, "a", format, args);
 139         va_end(args);
 140
 141         return res;
 142 }
 143
 144 static int check_term_format(const char *term, const char *orig_term)
 145 {
 146         int res;
 147         char *new_term = xstrfmt("refs/bisect/%s", term);
 148
 149         res = check_refname_format(new_term, 0);
 150         free(new_term);
 151
 152         if (res)
 153                 return error(_("'%s' is not a valid term"), term);
 154
 155         if (one_of(term, "help", "start", "skip", "next", "reset",
 156                         "visualize", "view", "replay", "log", "run", "terms", NULL))
 157                 return error(_("can't use the builtin command '%s' as a term"), term);
 158
 159         /*
 160          * In theory, nothing prevents swapping completely good and bad,
 161          * but this situation could be confusing and hasn't been tested
 162          * enough. Forbid it for now.
 163          */
 164
 165         if ((strcmp(orig_term, "bad") && one_of(term, "bad", "new", NULL)) ||
 166                  (strcmp(orig_term, "good") && one_of(term, "good", "old", NULL)))
 167                 return error(_("can't change the meaning of the term '%s'"), term);
 168
 169         return 0;
 170 }
 171
 172 static int write_terms(const char *bad, const char *good)
 173 {
 174         int res;
 175
 176         if (!strcmp(bad, good))
 177                 return error(_("please use two different terms"));
 178
 179         if (check_term_format(bad, "bad") || check_term_format(good, "good"))
 180                 return -1;
 181
 182         res = write_to_file(git_path_bisect_terms(), "%s\n%s\n", bad, good);
 183
 184         return res;
 185 }
 186
 187 static int bisect_reset(const char *commit)
 188 {
 189         struct strbuf branch = STRBUF_INIT;
 190
 191         if (!commit) {
 192                 if (strbuf_read_file(&branch, git_path_bisect_start(), 0) < 1) {
 193                         printf(_("We are not bisecting.\n"));
 194                         return 0;
 195                 }
 196                 strbuf_rtrim(&branch);
 197         } else {
 198                 struct object_id oid;
 199
 200                 if (get_oid_commit(commit, &oid))
 201                         return error(_("'%s' is not a valid commit"), commit);
 202                 strbuf_addstr(&branch, commit);
 203         }
 204
 205         if (!ref_exists("BISECT_HEAD")) {
 206                 struct strvec argv = STRVEC_INIT;
 207
 208                 strvec_pushl(&argv, "checkout", branch.buf, "--", NULL);
 209                 if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 210                         error(_("could not check out original"
 211                                 " HEAD '%s'. Try 'git bisect"
 212                                 " reset <commit>'."), branch.buf);
 213                         strbuf_release(&branch);
 214                         strvec_clear(&argv);
 215                         return -1;
 216                 }
 217                 strvec_clear(&argv);
 218         }
 219
 220         strbuf_release(&branch);
 221         return bisect_clean_state();
 222 }
 223
 224 static void log_commit(FILE *fp, char *fmt, const char *state,
 225                        struct commit *commit)
 226 {
 227         struct pretty_print_context pp = {0};
 228         struct strbuf commit_msg = STRBUF_INIT;
 229         char *label = xstrfmt(fmt, state);
 230
 231         format_commit_message(commit, "%s", &commit_msg, &pp);
 232
 233         fprintf(fp, "# %s: [%s] %s\n", label, oid_to_hex(&commit->object.oid),
 234                 commit_msg.buf);
 235
 236         strbuf_release(&commit_msg);
 237         free(label);
 238 }
 239
 240 static int bisect_write(const char *state, const char *rev,
 241                         const struct bisect_terms *terms, int nolog)
 242 {
 243         struct strbuf tag = STRBUF_INIT;
 244         struct object_id oid;
 245         struct commit *commit;
 246         FILE *fp = NULL;
 247         int res = 0;
 248
 249         if (!strcmp(state, terms->term_bad)) {
 250                 strbuf_addf(&tag, "refs/bisect/%s", state);
 251         } else if (one_of(state, terms->term_good, "skip", NULL)) {
 252                 strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
 253         } else {
 254                 res = error(_("Bad bisect_write argument: %s"), state);
 255                 goto finish;
 256         }
 257
 258         if (get_oid(rev, &oid)) {
 259                 res = error(_("couldn't get the oid of the rev '%s'"), rev);
 260                 goto finish;
 261         }
 262
 263         if (update_ref(NULL, tag.buf, &oid, NULL, 0,
 264                        UPDATE_REFS_MSG_ON_ERR)) {
 265                 res = -1;
 266                 goto finish;
 267         }
 268
 269         fp = fopen(git_path_bisect_log(), "a");
 270         if (!fp) {
 271                 res = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
 272                 goto finish;
 273         }
 274
 275         commit = lookup_commit_reference(the_repository, &oid);
 276         log_commit(fp, "%s", state, commit);
 277
 278         if (!nolog)
 279                 fprintf(fp, "git bisect %s %s\n", state, rev);
 280
 281 finish:
 282         if (fp)
 283                 fclose(fp);
 284         strbuf_release(&tag);
 285         return res;
 286 }
 287
 288 static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
 289 {
 290         int has_term_file = !is_empty_or_missing_file(git_path_bisect_terms());
 291
 292         if (one_of(cmd, "skip", "start", "terms", NULL))
 293                 return 0;
 294
 295         if (has_term_file && strcmp(cmd, terms->term_bad) &&
 296             strcmp(cmd, terms->term_good))
 297                 return error(_("Invalid command: you're currently in a "
 298                                 "%s/%s bisect"), terms->term_bad,
 299                                 terms->term_good);
 300
 301         if (!has_term_file) {
 302                 if (one_of(cmd, "bad", "good", NULL)) {
 303                         set_terms(terms, "bad", "good");
 304                         return write_terms(terms->term_bad, terms->term_good);
 305                 }
 306                 if (one_of(cmd, "new", "old", NULL)) {
 307                         set_terms(terms, "new", "old");
 308                         return write_terms(terms->term_bad, terms->term_good);
 309                 }
 310         }
 311
 312         return 0;
 313 }
 314
 315 static int mark_good(const char *refname, const struct object_id *oid,
 316                      int flag, void *cb_data)
 317 {
 318         int *m_good = (int *)cb_data;
 319         *m_good = 0;
 320         return 1;
 321 }
 322
 323 static const char need_bad_and_good_revision_warning[] =
 324         N_("You need to give me at least one %s and %s revision.\n"
 325            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 326
 327 static const char need_bisect_start_warning[] =
 328         N_("You need to start by \"git bisect start\".\n"
 329            "You then need to give me at least one %s and %s revision.\n"
 330            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 331
 332 static int decide_next(const struct bisect_terms *terms,
 333                        const char *current_term, int missing_good,
 334                        int missing_bad)
 335 {
 336         if (!missing_good && !missing_bad)
 337                 return 0;
 338         if (!current_term)
 339                 return -1;
 340
 341         if (missing_good && !missing_bad &&
 342             !strcmp(current_term, terms->term_good)) {
 343                 char *yesno;
 344                 /*
 345                  * have bad (or new) but not good (or old). We could bisect
 346                  * although this is less optimum.
 347                  */
 348                 warning(_("bisecting only with a %s commit"), terms->term_bad);
 349                 if (!isatty(0))
 350                         return 0;
 351                 /*
 352                  * TRANSLATORS: Make sure to include [Y] and [n] in your
 353                  * translation. The program will only accept English input
 354                  * at this point.
 355                  */
 356                 yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
 357                 if (starts_with(yesno, "N") || starts_with(yesno, "n"))
 358                         return -1;
 359                 return 0;
 360         }
 361
 362         if (!is_empty_or_missing_file(git_path_bisect_start()))
 363                 return error(_(need_bad_and_good_revision_warning),
 364                              vocab_bad, vocab_good, vocab_bad, vocab_good);
 365         else
 366                 return error(_(need_bisect_start_warning),
 367                              vocab_good, vocab_bad, vocab_good, vocab_bad);
 368 }
 369
 370 static int bisect_next_check(const struct bisect_terms *terms,
 371                              const char *current_term)
 372 {
 373         int missing_good = 1, missing_bad = 1;
 374         char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
 375         char *good_glob = xstrfmt("%s-*", terms->term_good);
 376
 377         if (ref_exists(bad_ref))
 378                 missing_bad = 0;
 379
 380         for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
 381                              (void *) &missing_good);
 382
 383         free(good_glob);
 384         free(bad_ref);
 385
 386         return decide_next(terms, current_term, missing_good, missing_bad);
 387 }
 388
 389 static int get_terms(struct bisect_terms *terms)
 390 {
 391         struct strbuf str = STRBUF_INIT;
 392         FILE *fp = NULL;
 393         int res = 0;
 394
 395         fp = fopen(git_path_bisect_terms(), "r");
 396         if (!fp) {
 397                 res = -1;
 398                 goto finish;
 399         }
 400
 401         free_terms(terms);
 402         strbuf_getline_lf(&str, fp);
 403         terms->term_bad = strbuf_detach(&str, NULL);
 404         strbuf_getline_lf(&str, fp);
 405         terms->term_good = strbuf_detach(&str, NULL);
 406
 407 finish:
 408         if (fp)
 409                 fclose(fp);
 410         strbuf_release(&str);
 411         return res;
 412 }
 413
 414 static int bisect_terms(struct bisect_terms *terms, const char *option)
 415 {
 416         if (get_terms(terms))
 417                 return error(_("no terms defined"));
 418
 419         if (option == NULL) {
 420                 printf(_("Your current terms are %s for the old state\n"
 421                          "and %s for the new state.\n"),
 422                        terms->term_good, terms->term_bad);
 423                 return 0;
 424         }
 425         if (one_of(option, "--term-good", "--term-old", NULL))
 426                 printf("%s\n", terms->term_good);
 427         else if (one_of(option, "--term-bad", "--term-new", NULL))
 428                 printf("%s\n", terms->term_bad);
 429         else
 430                 return error(_("invalid argument %s for 'git bisect terms'.\n"
 431                                "Supported options are: "
 432                                "--term-good|--term-old and "
 433                                "--term-bad|--term-new."), option);
 434
 435         return 0;
 436 }
 437
 438 static int bisect_append_log_quoted(const char **argv)
 439 {
 440         int res = 0;
 441         FILE *fp = fopen(git_path_bisect_log(), "a");
 442         struct strbuf orig_args = STRBUF_INIT;
 443
 444         if (!fp)
 445                 return -1;
 446
 447         if (fprintf(fp, "git bisect start") < 1) {
 448                 res = -1;
 449                 goto finish;
 450         }
 451
 452         sq_quote_argv(&orig_args, argv);
 453         if (fprintf(fp, "%s\n", orig_args.buf) < 1)
 454                 res = -1;
 455
 456 finish:
 457         fclose(fp);
 458         strbuf_release(&orig_args);
 459         return res;
 460 }
 461
 462 static int add_bisect_ref(const char *refname, const struct object_id *oid,
 463                           int flags, void *cb)
 464 {
 465         struct add_bisect_ref_data *data = cb;
 466
 467         add_pending_oid(data->revs, refname, oid, data->object_flags);
 468
 469         return 0;
 470 }
 471
 472 static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
 473 {
 474         int res = 0;
 475         struct add_bisect_ref_data cb = { revs };
 476         char *good = xstrfmt("%s-*", terms->term_good);
 477
 478         /*
 479          * We cannot use terms->term_bad directly in
 480          * for_each_glob_ref_in() and we have to append a '*' to it,
 481          * otherwise for_each_glob_ref_in() will append '/' and '*'.
 482          */
 483         char *bad = xstrfmt("%s*", terms->term_bad);
 484
 485         /*
 486          * It is important to reset the flags used by revision walks
 487          * as the previous call to bisect_next_all() in turn
 488          * sets up a revision walk.
 489          */
 490         reset_revision_walk();
 491         init_revisions(revs, NULL);
 492         setup_revisions(0, NULL, revs, NULL);
 493         for_each_glob_ref_in(add_bisect_ref, bad, "refs/bisect/", &cb);
 494         cb.object_flags = UNINTERESTING;
 495         for_each_glob_ref_in(add_bisect_ref, good, "refs/bisect/", &cb);
 496         if (prepare_revision_walk(revs))
 497                 res = error(_("revision walk setup failed\n"));
 498
 499         free(good);
 500         free(bad);
 501         return res;
 502 }
 503
 504 static int bisect_skipped_commits(struct bisect_terms *terms)
 505 {
 506         int res;
 507         FILE *fp = NULL;
 508         struct rev_info revs;
 509         struct commit *commit;
 510         struct pretty_print_context pp = {0};
 511         struct strbuf commit_name = STRBUF_INIT;
 512
 513         res = prepare_revs(terms, &revs);
 514         if (res)
 515                 return res;
 516
 517         fp = fopen(git_path_bisect_log(), "a");
 518         if (!fp)
 519                 return error_errno(_("could not open '%s' for appending"),
 520                                   git_path_bisect_log());
 521
 522         if (fprintf(fp, "# only skipped commits left to test\n") < 0)
 523                 return error_errno(_("failed to write to '%s'"), git_path_bisect_log());
 524
 525         while ((commit = get_revision(&revs)) != NULL) {
 526                 strbuf_reset(&commit_name);
 527                 format_commit_message(commit, "%s",
 528                                       &commit_name, &pp);
 529                 fprintf(fp, "# possible first %s commit: [%s] %s\n",
 530                         terms->term_bad, oid_to_hex(&commit->object.oid),
 531                         commit_name.buf);
 532         }
 533
 534         /*
 535          * Reset the flags used by revision walks in case
 536          * there is another revision walk after this one.
 537          */
 538         reset_revision_walk();
 539
 540         strbuf_release(&commit_name);
 541         fclose(fp);
 542         return 0;
 543 }
 544
 545 static int bisect_successful(struct bisect_terms *terms)
 546 {
 547         struct object_id oid;
 548         struct commit *commit;
 549         struct pretty_print_context pp = {0};
 550         struct strbuf commit_name = STRBUF_INIT;
 551         char *bad_ref = xstrfmt("refs/bisect/%s",terms->term_bad);
 552         int res;
 553
 554         read_ref(bad_ref, &oid);
 555         commit = lookup_commit_reference_by_name(bad_ref);
 556         format_commit_message(commit, "%s", &commit_name, &pp);
 557
 558         res = append_to_file(git_path_bisect_log(), "# first %s commit: [%s] %s\n",
 559                             terms->term_bad, oid_to_hex(&commit->object.oid),
 560                             commit_name.buf);
 561
 562         strbuf_release(&commit_name);
 563         free(bad_ref);
 564         return res;
 565 }
 566
 567 static enum bisect_error bisect_next(struct bisect_terms *terms, const char *prefix)
 568 {
 569         enum bisect_error res;
 570
 571         if (bisect_autostart(terms))
 572                 return BISECT_FAILED;
 573
 574         if (bisect_next_check(terms, terms->term_good))
 575                 return BISECT_FAILED;
 576
 577         /* Perform all bisection computation */
 578         res = bisect_next_all(the_repository, prefix);
 579
 580         if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
 581                 res = bisect_successful(terms);
 582                 return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
 583         } else if (res == BISECT_ONLY_SKIPPED_LEFT) {
 584                 res = bisect_skipped_commits(terms);
 585                 return res ? res : BISECT_ONLY_SKIPPED_LEFT;
 586         }
 587         return res;
 588 }
 589
 590 static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char *prefix)
 591 {
 592         if (bisect_next_check(terms, NULL))
 593                 return BISECT_OK;
 594
 595         return bisect_next(terms, prefix);
 596 }
 597
 598 static enum bisect_error bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 599 {
 600         int no_checkout = 0;
 601         int first_parent_only = 0;
 602         int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 603         int flags, pathspec_pos;
 604         enum bisect_error res = BISECT_OK;
 605         struct string_list revs = STRING_LIST_INIT_DUP;
 606         struct string_list states = STRING_LIST_INIT_DUP;
 607         struct strbuf start_head = STRBUF_INIT;
 608         struct strbuf bisect_names = STRBUF_INIT;
 609         struct object_id head_oid;
 610         struct object_id oid;
 611         const char *head;
 612
 613         if (is_bare_repository())
 614                 no_checkout = 1;
 615
 616         /*
 617          * Check for one bad and then some good revisions
 618          */
 619         for (i = 0; i < argc; i++) {
 620                 if (!strcmp(argv[i], "--")) {
 621                         has_double_dash = 1;
 622                         break;
 623                 }
 624         }
 625
 626         for (i = 0; i < argc; i++) {
 627                 const char *arg = argv[i];
 628                 if (!strcmp(argv[i], "--")) {
 629                         break;
 630                 } else if (!strcmp(arg, "--no-checkout")) {
 631                         no_checkout = 1;
 632                 } else if (!strcmp(arg, "--first-parent")) {
 633                         first_parent_only = 1;
 634                 } else if (!strcmp(arg, "--term-good") ||
 635                          !strcmp(arg, "--term-old")) {
 636                         i++;
 637                         if (argc <= i)
 638                                 return error(_("'' is not a valid term"));
 639                         must_write_terms = 1;
 640                         free((void *) terms->term_good);
 641                         terms->term_good = xstrdup(argv[i]);
 642                 } else if (skip_prefix(arg, "--term-good=", &arg) ||
 643                            skip_prefix(arg, "--term-old=", &arg)) {
 644                         must_write_terms = 1;
 645                         free((void *) terms->term_good);
 646                         terms->term_good = xstrdup(arg);
 647                 } else if (!strcmp(arg, "--term-bad") ||
 648                          !strcmp(arg, "--term-new")) {
 649                         i++;
 650                         if (argc <= i)
 651                                 return error(_("'' is not a valid term"));
 652                         must_write_terms = 1;
 653                         free((void *) terms->term_bad);
 654                         terms->term_bad = xstrdup(argv[i]);
 655                 } else if (skip_prefix(arg, "--term-bad=", &arg) ||
 656                            skip_prefix(arg, "--term-new=", &arg)) {
 657                         must_write_terms = 1;
 658                         free((void *) terms->term_bad);
 659                         terms->term_bad = xstrdup(arg);
 660                 } else if (starts_with(arg, "--")) {
 661                         return error(_("unrecognized option: '%s'"), arg);
 662                 } else if (!get_oidf(&oid, "%s^{commit}", arg)) {
 663                         string_list_append(&revs, oid_to_hex(&oid));
 664                 } else if (has_double_dash) {
 665                         die(_("'%s' does not appear to be a valid "
 666                               "revision"), arg);
 667                 } else {
 668                         break;
 669                 }
 670         }
 671         pathspec_pos = i;
 672
 673         /*
 674          * The user ran "git bisect start <sha1> <sha1>", hence did not
 675          * explicitly specify the terms, but we are already starting to
 676          * set references named with the default terms, and won't be able
 677          * to change afterwards.
 678          */
 679         if (revs.nr)
 680                 must_write_terms = 1;
 681         for (i = 0; i < revs.nr; i++) {
 682                 if (bad_seen) {
 683                         string_list_append(&states, terms->term_good);
 684                 } else {
 685                         bad_seen = 1;
 686                         string_list_append(&states, terms->term_bad);
 687                 }
 688         }
 689
 690         /*
 691          * Verify HEAD
 692          */
 693         head = resolve_ref_unsafe("HEAD", 0, &head_oid, &flags);
 694         if (!head)
 695                 if (get_oid("HEAD", &head_oid))
 696                         return error(_("bad HEAD - I need a HEAD"));
 697
 698         /*
 699          * Check if we are bisecting
 700          */
 701         if (!is_empty_or_missing_file(git_path_bisect_start())) {
 702                 /* Reset to the rev from where we started */
 703                 strbuf_read_file(&start_head, git_path_bisect_start(), 0);
 704                 strbuf_trim(&start_head);
 705                 if (!no_checkout) {
 706                         struct strvec argv = STRVEC_INIT;
 707
 708                         strvec_pushl(&argv, "checkout", start_head.buf,
 709                                      "--", NULL);
 710                         if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 711                                 res = error(_("checking out '%s' failed."
 712                                                  " Try 'git bisect start "
 713                                                  "<valid-branch>'."),
 714                                                start_head.buf);
 715                                 goto finish;
 716                         }
 717                 }
 718         } else {
 719                 /* Get the rev from where we start. */
 720                 if (!get_oid(head, &head_oid) &&
 721                     !starts_with(head, "refs/heads/")) {
 722                         strbuf_reset(&start_head);
 723                         strbuf_addstr(&start_head, oid_to_hex(&head_oid));
 724                 } else if (!get_oid(head, &head_oid) &&
 725                            skip_prefix(head, "refs/heads/", &head)) {
 726                         /*
 727                          * This error message should only be triggered by
 728                          * cogito usage, and cogito users should understand
 729                          * it relates to cg-seek.
 730                          */
 731                         if (!is_empty_or_missing_file(git_path_head_name()))
 732                                 return error(_("won't bisect on cg-seek'ed tree"));
 733                         strbuf_addstr(&start_head, head);
 734                 } else {
 735                         return error(_("bad HEAD - strange symbolic ref"));
 736                 }
 737         }
 738
 739         /*
 740          * Get rid of any old bisect state.
 741          */
 742         if (bisect_clean_state())
 743                 return BISECT_FAILED;
 744
 745         /*
 746          * Write new start state
 747          */
 748         write_file(git_path_bisect_start(), "%s\n", start_head.buf);
 749
 750         if (first_parent_only)
 751                 write_file(git_path_bisect_first_parent(), "\n");
 752
 753         if (no_checkout) {
 754                 if (get_oid(start_head.buf, &oid) < 0) {
 755                         res = error(_("invalid ref: '%s'"), start_head.buf);
 756                         goto finish;
 757                 }
 758                 if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 759                                UPDATE_REFS_MSG_ON_ERR)) {
 760                         res = BISECT_FAILED;
 761                         goto finish;
 762                 }
 763         }
 764
 765         if (pathspec_pos < argc - 1)
 766                 sq_quote_argv(&bisect_names, argv + pathspec_pos);
 767         write_file(git_path_bisect_names(), "%s\n", bisect_names.buf);
 768
 769         for (i = 0; i < states.nr; i++)
 770                 if (bisect_write(states.items[i].string,
 771                                  revs.items[i].string, terms, 1)) {
 772                         res = BISECT_FAILED;
 773                         goto finish;
 774                 }
 775
 776         if (must_write_terms && write_terms(terms->term_bad,
 777                                             terms->term_good)) {
 778                 res = BISECT_FAILED;
 779                 goto finish;
 780         }
 781
 782         res = bisect_append_log_quoted(argv);
 783         if (res)
 784                 res = BISECT_FAILED;
 785
 786 finish:
 787         string_list_clear(&revs, 0);
 788         string_list_clear(&states, 0);
 789         strbuf_release(&start_head);
 790         strbuf_release(&bisect_names);
 791         if (res)
 792                 return res;
 793
 794         res = bisect_auto_next(terms, NULL);
 795         if (!is_bisect_success(res))
 796                 bisect_clean_state();
 797         return res;
 798 }
 799
 800 static inline int file_is_not_empty(const char *path)
 801 {
 802         return !is_empty_or_missing_file(path);
 803 }
 804
 805 static int bisect_autostart(struct bisect_terms *terms)
 806 {
 807         int res;
 808         const char *yesno;
 809
 810         if (file_is_not_empty(git_path_bisect_start()))
 811                 return 0;
 812
 813         fprintf_ln(stderr, _("You need to start by \"git bisect "
 814                           "start\"\n"));
 815
 816         if (!isatty(STDIN_FILENO))
 817                 return -1;
 818
 819         /*
 820          * TRANSLATORS: Make sure to include [Y] and [n] in your
 821          * translation. The program will only accept English input
 822          * at this point.
 823          */
 824         yesno = git_prompt(_("Do you want me to do it for you "
 825                              "[Y/n]? "), PROMPT_ECHO);
 826         res = tolower(*yesno) == 'n' ?
 827                 -1 : bisect_start(terms, empty_strvec, 0);
 828
 829         return res;
 830 }
 831
 832 static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
 833                                       int argc)
 834 {
 835         const char *state;
 836         int i, verify_expected = 1;
 837         struct object_id oid, expected;
 838         struct strbuf buf = STRBUF_INIT;
 839         struct oid_array revs = OID_ARRAY_INIT;
 840
 841         if (!argc)
 842                 return error(_("Please call `--bisect-state` with at least one argument"));
 843
 844         if (bisect_autostart(terms))
 845                 return BISECT_FAILED;
 846
 847         state = argv[0];
 848         if (check_and_set_terms(terms, state) ||
 849             !one_of(state, terms->term_good, terms->term_bad, "skip", NULL))
 850                 return BISECT_FAILED;
 851
 852         argv++;
 853         argc--;
 854         if (argc > 1 && !strcmp(state, terms->term_bad))
 855                 return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
 856
 857         if (argc == 0) {
 858                 const char *head = "BISECT_HEAD";
 859                 enum get_oid_result res_head = get_oid(head, &oid);
 860
 861                 if (res_head == MISSING_OBJECT) {
 862                         head = "HEAD";
 863                         res_head = get_oid(head, &oid);
 864                 }
 865
 866                 if (res_head)
 867                         error(_("Bad rev input: %s"), head);
 868                 oid_array_append(&revs, &oid);
 869         }
 870
 871         /*
 872          * All input revs must be checked before executing bisect_write()
 873          * to discard junk revs.
 874          */
 875
 876         for (; argc; argc--, argv++) {
 877                 struct commit *commit;
 878
 879                 if (get_oid(*argv, &oid)){
 880                         error(_("Bad rev input: %s"), *argv);
 881                         oid_array_clear(&revs);
 882                         return BISECT_FAILED;
 883                 }
 884
 885                 commit = lookup_commit_reference(the_repository, &oid);
 886                 if (!commit)
 887                         die(_("Bad rev input (not a commit): %s"), *argv);
 888
 889                 oid_array_append(&revs, &commit->object.oid);
 890         }
 891
 892         if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
 893             get_oid_hex(buf.buf, &expected) < 0)
 894                 verify_expected = 0; /* Ignore invalid file contents */
 895         strbuf_release(&buf);
 896
 897         for (i = 0; i < revs.nr; i++) {
 898                 if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0)) {
 899                         oid_array_clear(&revs);
 900                         return BISECT_FAILED;
 901                 }
 902                 if (verify_expected && !oideq(&revs.oid[i], &expected)) {
 903                         unlink_or_warn(git_path_bisect_ancestors_ok());
 904                         unlink_or_warn(git_path_bisect_expected_rev());
 905                         verify_expected = 0;
 906                 }
 907         }
 908
 909         oid_array_clear(&revs);
 910         return bisect_auto_next(terms, NULL);
 911 }
 912
 913 static enum bisect_error bisect_log(void)
 914 {
 915         int fd, status;
 916         const char* filename = git_path_bisect_log();
 917
 918         if (is_empty_or_missing_file(filename))
 919                 return error(_("We are not bisecting."));
 920
 921         fd = open(filename, O_RDONLY);
 922         if (fd < 0)
 923                 return BISECT_FAILED;
 924
 925         status = copy_fd(fd, STDOUT_FILENO);
 926         close(fd);
 927         return status ? BISECT_FAILED : BISECT_OK;
 928 }
 929
 930 static int process_replay_line(struct bisect_terms *terms, struct strbuf *line)
 931 {
 932         const char *p = line->buf + strspn(line->buf, " \t");
 933         char *word_end, *rev;
 934
 935         if ((!skip_prefix(p, "git bisect", &p) &&
 936         !skip_prefix(p, "git-bisect", &p)) || !isspace(*p))
 937                 return 0;
 938         p += strspn(p, " \t");
 939
 940         word_end = (char *)p + strcspn(p, " \t");
 941         rev = word_end + strspn(word_end, " \t");
 942         *word_end = '\0'; /* NUL-terminate the word */
 943
 944         get_terms(terms);
 945         if (check_and_set_terms(terms, p))
 946                 return -1;
 947
 948         if (!strcmp(p, "start")) {
 949                 struct strvec argv = STRVEC_INIT;
 950                 int res;
 951                 sq_dequote_to_strvec(rev, &argv);
 952                 res = bisect_start(terms, argv.v, argv.nr);
 953                 strvec_clear(&argv);
 954                 return res;
 955         }
 956
 957         if (one_of(p, terms->term_good,
 958            terms->term_bad, "skip", NULL))
 959                 return bisect_write(p, rev, terms, 0);
 960
 961         if (!strcmp(p, "terms")) {
 962                 struct strvec argv = STRVEC_INIT;
 963                 int res;
 964                 sq_dequote_to_strvec(rev, &argv);
 965                 res = bisect_terms(terms, argv.nr == 1 ? argv.v[0] : NULL);
 966                 strvec_clear(&argv);
 967                 return res;
 968         }
 969         error(_("'%s'?? what are you talking about?"), p);
 970
 971         return -1;
 972 }
 973
 974 static enum bisect_error bisect_replay(struct bisect_terms *terms, const char *filename)
 975 {
 976         FILE *fp = NULL;
 977         enum bisect_error res = BISECT_OK;
 978         struct strbuf line = STRBUF_INIT;
 979
 980         if (is_empty_or_missing_file(filename))
 981                 return error(_("cannot read file '%s' for replaying"), filename);
 982
 983         if (bisect_reset(NULL))
 984                 return BISECT_FAILED;
 985
 986         fp = fopen(filename, "r");
 987         if (!fp)
 988                 return BISECT_FAILED;
 989
 990         while ((strbuf_getline(&line, fp) != EOF) && !res)
 991                 res = process_replay_line(terms, &line);
 992
 993         strbuf_release(&line);
 994         fclose(fp);
 995
 996         if (res)
 997                 return BISECT_FAILED;
 998
 999         return bisect_auto_next(terms, NULL);
1000 }
1001
1002 static enum bisect_error bisect_skip(struct bisect_terms *terms, const char **argv, int argc)
1003 {
1004         int i;
1005         enum bisect_error res;
1006         struct strvec argv_state = STRVEC_INIT;
1007
1008         strvec_push(&argv_state, "skip");
1009
1010         for (i = 0; i < argc; i++) {
1011                 const char *dotdot = strstr(argv[i], "..");
1012
1013                 if (dotdot) {
1014                         struct rev_info revs;
1015                         struct commit *commit;
1016
1017                         init_revisions(&revs, NULL);
1018                         setup_revisions(2, argv + i - 1, &revs, NULL);
1019
1020                         if (prepare_revision_walk(&revs))
1021                                 die(_("revision walk setup failed\n"));
1022                         while ((commit = get_revision(&revs)) != NULL)
1023                                 strvec_push(&argv_state,
1024                                                 oid_to_hex(&commit->object.oid));
1025
1026                         reset_revision_walk();
1027                 } else {
1028                         strvec_push(&argv_state, argv[i]);
1029                 }
1030         }
1031         res = bisect_state(terms, argv_state.v, argv_state.nr);
1032
1033         strvec_clear(&argv_state);
1034         return res;
1035 }
1036
1037 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
1038 {
1039         enum {
1040                 BISECT_RESET = 1,
1041                 BISECT_NEXT_CHECK,
1042                 BISECT_TERMS,
1043                 BISECT_START,
1044                 BISECT_AUTOSTART,
1045                 BISECT_NEXT,
1046                 BISECT_STATE,
1047                 BISECT_LOG,
1048                 BISECT_REPLAY,
1049                 BISECT_SKIP
1050         } cmdmode = 0;
1051         int res = 0, nolog = 0;
1052         struct option options[] = {
1053                 OPT_CMDMODE(0, "bisect-reset", &cmdmode,
1054                          N_("reset the bisection state"), BISECT_RESET),
1055                 OPT_CMDMODE(0, "bisect-next-check", &cmdmode,
1056                          N_("check whether bad or good terms exist"), BISECT_NEXT_CHECK),
1057                 OPT_CMDMODE(0, "bisect-terms", &cmdmode,
1058                          N_("print out the bisect terms"), BISECT_TERMS),
1059                 OPT_CMDMODE(0, "bisect-start", &cmdmode,
1060                          N_("start the bisect session"), BISECT_START),
1061                 OPT_CMDMODE(0, "bisect-next", &cmdmode,
1062                          N_("find the next bisection commit"), BISECT_NEXT),
1063                 OPT_CMDMODE(0, "bisect-state", &cmdmode,
1064                          N_("mark the state of ref (or refs)"), BISECT_STATE),
1065                 OPT_CMDMODE(0, "bisect-log", &cmdmode,
1066                          N_("list the bisection steps so far"), BISECT_LOG),
1067                 OPT_CMDMODE(0, "bisect-replay", &cmdmode,
1068                          N_("replay the bisection process from the given file"), BISECT_REPLAY),
1069                 OPT_CMDMODE(0, "bisect-skip", &cmdmode,
1070                          N_("skip some commits for checkout"), BISECT_SKIP),
1071                 OPT_BOOL(0, "no-log", &nolog,
1072                          N_("no log for BISECT_WRITE")),
1073                 OPT_END()
1074         };
1075         struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
1076
1077         argc = parse_options(argc, argv, prefix, options,
1078                              git_bisect_helper_usage,
1079                              PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN);
1080
1081         if (!cmdmode)
1082                 usage_with_options(git_bisect_helper_usage, options);
1083
1084         switch (cmdmode) {
1085         case BISECT_RESET:
1086                 if (argc > 1)
1087                         return error(_("--bisect-reset requires either no argument or a commit"));
1088                 res = bisect_reset(argc ? argv[0] : NULL);
1089                 break;
1090         case BISECT_NEXT_CHECK:
1091                 if (argc != 2 && argc != 3)
1092                         return error(_("--bisect-next-check requires 2 or 3 arguments"));
1093                 set_terms(&terms, argv[1], argv[0]);
1094                 res = bisect_next_check(&terms, argc == 3 ? argv[2] : NULL);
1095                 break;
1096         case BISECT_TERMS:
1097                 if (argc > 1)
1098                         return error(_("--bisect-terms requires 0 or 1 argument"));
1099                 res = bisect_terms(&terms, argc == 1 ? argv[0] : NULL);
1100                 break;
1101         case BISECT_START:
1102                 set_terms(&terms, "bad", "good");
1103                 res = bisect_start(&terms, argv, argc);
1104                 break;
1105         case BISECT_NEXT:
1106                 if (argc)
1107                         return error(_("--bisect-next requires 0 arguments"));
1108                 get_terms(&terms);
1109                 res = bisect_next(&terms, prefix);
1110                 break;
1111         case BISECT_STATE:
1112                 set_terms(&terms, "bad", "good");
1113                 get_terms(&terms);
1114                 res = bisect_state(&terms, argv, argc);
1115                 break;
1116         case BISECT_LOG:
1117                 if (argc)
1118                         return error(_("--bisect-log requires 0 arguments"));
1119                 res = bisect_log();
1120                 break;
1121         case BISECT_REPLAY:
1122                 if (argc != 1)
1123                         return error(_("no logfile given"));
1124                 set_terms(&terms, "bad", "good");
1125                 res = bisect_replay(&terms, argv[0]);
1126                 break;
1127         case BISECT_SKIP:
1128                 set_terms(&terms, "bad", "good");
1129                 res = bisect_skip(&terms, argv, argc);
1130                 break;
1131         default:
1132                 BUG("unknown subcommand %d", cmdmode);
1133         }
1134         free_terms(&terms);
1135
1136         /*
1137          * Handle early success
1138          * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
1139          */
1140         if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
1141                 res = BISECT_OK;
1142
1143         return -res;
1144 }