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 __attribute__((format (printf, 2, 3)))
 121 static int write_to_file(const char *path, const char *format, ...)
 122 {
 123         int res;
 124         va_list args;
 125
 126         va_start(args, format);
 127         res = write_in_file(path, "w", format, args);
 128         va_end(args);
 129
 130         return res;
 131 }
 132
 133 __attribute__((format (printf, 2, 3)))
 134 static int append_to_file(const char *path, const char *format, ...)
 135 {
 136         int res;
 137         va_list args;
 138
 139         va_start(args, format);
 140         res = write_in_file(path, "a", format, args);
 141         va_end(args);
 142
 143         return res;
 144 }
 145
 146 static int check_term_format(const char *term, const char *orig_term)
 147 {
 148         int res;
 149         char *new_term = xstrfmt("refs/bisect/%s", term);
 150
 151         res = check_refname_format(new_term, 0);
 152         free(new_term);
 153
 154         if (res)
 155                 return error(_("'%s' is not a valid term"), term);
 156
 157         if (one_of(term, "help", "start", "skip", "next", "reset",
 158                         "visualize", "view", "replay", "log", "run", "terms", NULL))
 159                 return error(_("can't use the builtin command '%s' as a term"), term);
 160
 161         /*
 162          * In theory, nothing prevents swapping completely good and bad,
 163          * but this situation could be confusing and hasn't been tested
 164          * enough. Forbid it for now.
 165          */
 166
 167         if ((strcmp(orig_term, "bad") && one_of(term, "bad", "new", NULL)) ||
 168                  (strcmp(orig_term, "good") && one_of(term, "good", "old", NULL)))
 169                 return error(_("can't change the meaning of the term '%s'"), term);
 170
 171         return 0;
 172 }
 173
 174 static int write_terms(const char *bad, const char *good)
 175 {
 176         int res;
 177
 178         if (!strcmp(bad, good))
 179                 return error(_("please use two different terms"));
 180
 181         if (check_term_format(bad, "bad") || check_term_format(good, "good"))
 182                 return -1;
 183
 184         res = write_to_file(git_path_bisect_terms(), "%s\n%s\n", bad, good);
 185
 186         return res;
 187 }
 188
 189 static int bisect_reset(const char *commit)
 190 {
 191         struct strbuf branch = STRBUF_INIT;
 192
 193         if (!commit) {
 194                 if (strbuf_read_file(&branch, git_path_bisect_start(), 0) < 1) {
 195                         printf(_("We are not bisecting.\n"));
 196                         return 0;
 197                 }
 198                 strbuf_rtrim(&branch);
 199         } else {
 200                 struct object_id oid;
 201
 202                 if (get_oid_commit(commit, &oid))
 203                         return error(_("'%s' is not a valid commit"), commit);
 204                 strbuf_addstr(&branch, commit);
 205         }
 206
 207         if (!ref_exists("BISECT_HEAD")) {
 208                 struct strvec argv = STRVEC_INIT;
 209
 210                 strvec_pushl(&argv, "checkout", branch.buf, "--", NULL);
 211                 if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 212                         error(_("could not check out original"
 213                                 " HEAD '%s'. Try 'git bisect"
 214                                 " reset <commit>'."), branch.buf);
 215                         strbuf_release(&branch);
 216                         strvec_clear(&argv);
 217                         return -1;
 218                 }
 219                 strvec_clear(&argv);
 220         }
 221
 222         strbuf_release(&branch);
 223         return bisect_clean_state();
 224 }
 225
 226 static void log_commit(FILE *fp, char *fmt, const char *state,
 227                        struct commit *commit)
 228 {
 229         struct pretty_print_context pp = {0};
 230         struct strbuf commit_msg = STRBUF_INIT;
 231         char *label = xstrfmt(fmt, state);
 232
 233         format_commit_message(commit, "%s", &commit_msg, &pp);
 234
 235         fprintf(fp, "# %s: [%s] %s\n", label, oid_to_hex(&commit->object.oid),
 236                 commit_msg.buf);
 237
 238         strbuf_release(&commit_msg);
 239         free(label);
 240 }
 241
 242 static int bisect_write(const char *state, const char *rev,
 243                         const struct bisect_terms *terms, int nolog)
 244 {
 245         struct strbuf tag = STRBUF_INIT;
 246         struct object_id oid;
 247         struct commit *commit;
 248         FILE *fp = NULL;
 249         int res = 0;
 250
 251         if (!strcmp(state, terms->term_bad)) {
 252                 strbuf_addf(&tag, "refs/bisect/%s", state);
 253         } else if (one_of(state, terms->term_good, "skip", NULL)) {
 254                 strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
 255         } else {
 256                 res = error(_("Bad bisect_write argument: %s"), state);
 257                 goto finish;
 258         }
 259
 260         if (get_oid(rev, &oid)) {
 261                 res = error(_("couldn't get the oid of the rev '%s'"), rev);
 262                 goto finish;
 263         }
 264
 265         if (update_ref(NULL, tag.buf, &oid, NULL, 0,
 266                        UPDATE_REFS_MSG_ON_ERR)) {
 267                 res = -1;
 268                 goto finish;
 269         }
 270
 271         fp = fopen(git_path_bisect_log(), "a");
 272         if (!fp) {
 273                 res = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
 274                 goto finish;
 275         }
 276
 277         commit = lookup_commit_reference(the_repository, &oid);
 278         log_commit(fp, "%s", state, commit);
 279
 280         if (!nolog)
 281                 fprintf(fp, "git bisect %s %s\n", state, rev);
 282
 283 finish:
 284         if (fp)
 285                 fclose(fp);
 286         strbuf_release(&tag);
 287         return res;
 288 }
 289
 290 static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
 291 {
 292         int has_term_file = !is_empty_or_missing_file(git_path_bisect_terms());
 293
 294         if (one_of(cmd, "skip", "start", "terms", NULL))
 295                 return 0;
 296
 297         if (has_term_file && strcmp(cmd, terms->term_bad) &&
 298             strcmp(cmd, terms->term_good))
 299                 return error(_("Invalid command: you're currently in a "
 300                                 "%s/%s bisect"), terms->term_bad,
 301                                 terms->term_good);
 302
 303         if (!has_term_file) {
 304                 if (one_of(cmd, "bad", "good", NULL)) {
 305                         set_terms(terms, "bad", "good");
 306                         return write_terms(terms->term_bad, terms->term_good);
 307                 }
 308                 if (one_of(cmd, "new", "old", NULL)) {
 309                         set_terms(terms, "new", "old");
 310                         return write_terms(terms->term_bad, terms->term_good);
 311                 }
 312         }
 313
 314         return 0;
 315 }
 316
 317 static int mark_good(const char *refname, const struct object_id *oid,
 318                      int flag, void *cb_data)
 319 {
 320         int *m_good = (int *)cb_data;
 321         *m_good = 0;
 322         return 1;
 323 }
 324
 325 static const char need_bad_and_good_revision_warning[] =
 326         N_("You need to give me at least one %s and %s revision.\n"
 327            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 328
 329 static const char need_bisect_start_warning[] =
 330         N_("You need to start by \"git bisect start\".\n"
 331            "You then need to give me at least one %s and %s revision.\n"
 332            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 333
 334 static int decide_next(const struct bisect_terms *terms,
 335                        const char *current_term, int missing_good,
 336                        int missing_bad)
 337 {
 338         if (!missing_good && !missing_bad)
 339                 return 0;
 340         if (!current_term)
 341                 return -1;
 342
 343         if (missing_good && !missing_bad &&
 344             !strcmp(current_term, terms->term_good)) {
 345                 char *yesno;
 346                 /*
 347                  * have bad (or new) but not good (or old). We could bisect
 348                  * although this is less optimum.
 349                  */
 350                 warning(_("bisecting only with a %s commit"), terms->term_bad);
 351                 if (!isatty(0))
 352                         return 0;
 353                 /*
 354                  * TRANSLATORS: Make sure to include [Y] and [n] in your
 355                  * translation. The program will only accept English input
 356                  * at this point.
 357                  */
 358                 yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
 359                 if (starts_with(yesno, "N") || starts_with(yesno, "n"))
 360                         return -1;
 361                 return 0;
 362         }
 363
 364         if (!is_empty_or_missing_file(git_path_bisect_start()))
 365                 return error(_(need_bad_and_good_revision_warning),
 366                              vocab_bad, vocab_good, vocab_bad, vocab_good);
 367         else
 368                 return error(_(need_bisect_start_warning),
 369                              vocab_good, vocab_bad, vocab_good, vocab_bad);
 370 }
 371
 372 static int bisect_next_check(const struct bisect_terms *terms,
 373                              const char *current_term)
 374 {
 375         int missing_good = 1, missing_bad = 1;
 376         char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
 377         char *good_glob = xstrfmt("%s-*", terms->term_good);
 378
 379         if (ref_exists(bad_ref))
 380                 missing_bad = 0;
 381
 382         for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
 383                              (void *) &missing_good);
 384
 385         free(good_glob);
 386         free(bad_ref);
 387
 388         return decide_next(terms, current_term, missing_good, missing_bad);
 389 }
 390
 391 static int get_terms(struct bisect_terms *terms)
 392 {
 393         struct strbuf str = STRBUF_INIT;
 394         FILE *fp = NULL;
 395         int res = 0;
 396
 397         fp = fopen(git_path_bisect_terms(), "r");
 398         if (!fp) {
 399                 res = -1;
 400                 goto finish;
 401         }
 402
 403         free_terms(terms);
 404         strbuf_getline_lf(&str, fp);
 405         terms->term_bad = strbuf_detach(&str, NULL);
 406         strbuf_getline_lf(&str, fp);
 407         terms->term_good = strbuf_detach(&str, NULL);
 408
 409 finish:
 410         if (fp)
 411                 fclose(fp);
 412         strbuf_release(&str);
 413         return res;
 414 }
 415
 416 static int bisect_terms(struct bisect_terms *terms, const char *option)
 417 {
 418         if (get_terms(terms))
 419                 return error(_("no terms defined"));
 420
 421         if (option == NULL) {
 422                 printf(_("Your current terms are %s for the old state\n"
 423                          "and %s for the new state.\n"),
 424                        terms->term_good, terms->term_bad);
 425                 return 0;
 426         }
 427         if (one_of(option, "--term-good", "--term-old", NULL))
 428                 printf("%s\n", terms->term_good);
 429         else if (one_of(option, "--term-bad", "--term-new", NULL))
 430                 printf("%s\n", terms->term_bad);
 431         else
 432                 return error(_("invalid argument %s for 'git bisect terms'.\n"
 433                                "Supported options are: "
 434                                "--term-good|--term-old and "
 435                                "--term-bad|--term-new."), option);
 436
 437         return 0;
 438 }
 439
 440 static int bisect_append_log_quoted(const char **argv)
 441 {
 442         int res = 0;
 443         FILE *fp = fopen(git_path_bisect_log(), "a");
 444         struct strbuf orig_args = STRBUF_INIT;
 445
 446         if (!fp)
 447                 return -1;
 448
 449         if (fprintf(fp, "git bisect start") < 1) {
 450                 res = -1;
 451                 goto finish;
 452         }
 453
 454         sq_quote_argv(&orig_args, argv);
 455         if (fprintf(fp, "%s\n", orig_args.buf) < 1)
 456                 res = -1;
 457
 458 finish:
 459         fclose(fp);
 460         strbuf_release(&orig_args);
 461         return res;
 462 }
 463
 464 static int add_bisect_ref(const char *refname, const struct object_id *oid,
 465                           int flags, void *cb)
 466 {
 467         struct add_bisect_ref_data *data = cb;
 468
 469         add_pending_oid(data->revs, refname, oid, data->object_flags);
 470
 471         return 0;
 472 }
 473
 474 static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
 475 {
 476         int res = 0;
 477         struct add_bisect_ref_data cb = { revs };
 478         char *good = xstrfmt("%s-*", terms->term_good);
 479
 480         /*
 481          * We cannot use terms->term_bad directly in
 482          * for_each_glob_ref_in() and we have to append a '*' to it,
 483          * otherwise for_each_glob_ref_in() will append '/' and '*'.
 484          */
 485         char *bad = xstrfmt("%s*", terms->term_bad);
 486
 487         /*
 488          * It is important to reset the flags used by revision walks
 489          * as the previous call to bisect_next_all() in turn
 490          * sets up a revision walk.
 491          */
 492         reset_revision_walk();
 493         init_revisions(revs, NULL);
 494         setup_revisions(0, NULL, revs, NULL);
 495         for_each_glob_ref_in(add_bisect_ref, bad, "refs/bisect/", &cb);
 496         cb.object_flags = UNINTERESTING;
 497         for_each_glob_ref_in(add_bisect_ref, good, "refs/bisect/", &cb);
 498         if (prepare_revision_walk(revs))
 499                 res = error(_("revision walk setup failed\n"));
 500
 501         free(good);
 502         free(bad);
 503         return res;
 504 }
 505
 506 static int bisect_skipped_commits(struct bisect_terms *terms)
 507 {
 508         int res;
 509         FILE *fp = NULL;
 510         struct rev_info revs;
 511         struct commit *commit;
 512         struct pretty_print_context pp = {0};
 513         struct strbuf commit_name = STRBUF_INIT;
 514
 515         res = prepare_revs(terms, &revs);
 516         if (res)
 517                 return res;
 518
 519         fp = fopen(git_path_bisect_log(), "a");
 520         if (!fp)
 521                 return error_errno(_("could not open '%s' for appending"),
 522                                   git_path_bisect_log());
 523
 524         if (fprintf(fp, "# only skipped commits left to test\n") < 0)
 525                 return error_errno(_("failed to write to '%s'"), git_path_bisect_log());
 526
 527         while ((commit = get_revision(&revs)) != NULL) {
 528                 strbuf_reset(&commit_name);
 529                 format_commit_message(commit, "%s",
 530                                       &commit_name, &pp);
 531                 fprintf(fp, "# possible first %s commit: [%s] %s\n",
 532                         terms->term_bad, oid_to_hex(&commit->object.oid),
 533                         commit_name.buf);
 534         }
 535
 536         /*
 537          * Reset the flags used by revision walks in case
 538          * there is another revision walk after this one.
 539          */
 540         reset_revision_walk();
 541
 542         strbuf_release(&commit_name);
 543         fclose(fp);
 544         return 0;
 545 }
 546
 547 static int bisect_successful(struct bisect_terms *terms)
 548 {
 549         struct object_id oid;
 550         struct commit *commit;
 551         struct pretty_print_context pp = {0};
 552         struct strbuf commit_name = STRBUF_INIT;
 553         char *bad_ref = xstrfmt("refs/bisect/%s",terms->term_bad);
 554         int res;
 555
 556         read_ref(bad_ref, &oid);
 557         commit = lookup_commit_reference_by_name(bad_ref);
 558         format_commit_message(commit, "%s", &commit_name, &pp);
 559
 560         res = append_to_file(git_path_bisect_log(), "# first %s commit: [%s] %s\n",
 561                             terms->term_bad, oid_to_hex(&commit->object.oid),
 562                             commit_name.buf);
 563
 564         strbuf_release(&commit_name);
 565         free(bad_ref);
 566         return res;
 567 }
 568
 569 static enum bisect_error bisect_next(struct bisect_terms *terms, const char *prefix)
 570 {
 571         enum bisect_error res;
 572
 573         if (bisect_autostart(terms))
 574                 return BISECT_FAILED;
 575
 576         if (bisect_next_check(terms, terms->term_good))
 577                 return BISECT_FAILED;
 578
 579         /* Perform all bisection computation */
 580         res = bisect_next_all(the_repository, prefix);
 581
 582         if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
 583                 res = bisect_successful(terms);
 584                 return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
 585         } else if (res == BISECT_ONLY_SKIPPED_LEFT) {
 586                 res = bisect_skipped_commits(terms);
 587                 return res ? res : BISECT_ONLY_SKIPPED_LEFT;
 588         }
 589         return res;
 590 }
 591
 592 static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char *prefix)
 593 {
 594         if (bisect_next_check(terms, NULL))
 595                 return BISECT_OK;
 596
 597         return bisect_next(terms, prefix);
 598 }
 599
 600 static enum bisect_error bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 601 {
 602         int no_checkout = 0;
 603         int first_parent_only = 0;
 604         int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 605         int flags, pathspec_pos;
 606         enum bisect_error res = BISECT_OK;
 607         struct string_list revs = STRING_LIST_INIT_DUP;
 608         struct string_list states = STRING_LIST_INIT_DUP;
 609         struct strbuf start_head = STRBUF_INIT;
 610         struct strbuf bisect_names = STRBUF_INIT;
 611         struct object_id head_oid;
 612         struct object_id oid;
 613         const char *head;
 614
 615         if (is_bare_repository())
 616                 no_checkout = 1;
 617
 618         /*
 619          * Check for one bad and then some good revisions
 620          */
 621         for (i = 0; i < argc; i++) {
 622                 if (!strcmp(argv[i], "--")) {
 623                         has_double_dash = 1;
 624                         break;
 625                 }
 626         }
 627
 628         for (i = 0; i < argc; i++) {
 629                 const char *arg = argv[i];
 630                 if (!strcmp(argv[i], "--")) {
 631                         break;
 632                 } else if (!strcmp(arg, "--no-checkout")) {
 633                         no_checkout = 1;
 634                 } else if (!strcmp(arg, "--first-parent")) {
 635                         first_parent_only = 1;
 636                 } else if (!strcmp(arg, "--term-good") ||
 637                          !strcmp(arg, "--term-old")) {
 638                         i++;
 639                         if (argc <= i)
 640                                 return error(_("'' is not a valid term"));
 641                         must_write_terms = 1;
 642                         free((void *) terms->term_good);
 643                         terms->term_good = xstrdup(argv[i]);
 644                 } else if (skip_prefix(arg, "--term-good=", &arg) ||
 645                            skip_prefix(arg, "--term-old=", &arg)) {
 646                         must_write_terms = 1;
 647                         free((void *) terms->term_good);
 648                         terms->term_good = xstrdup(arg);
 649                 } else if (!strcmp(arg, "--term-bad") ||
 650                          !strcmp(arg, "--term-new")) {
 651                         i++;
 652                         if (argc <= i)
 653                                 return error(_("'' is not a valid term"));
 654                         must_write_terms = 1;
 655                         free((void *) terms->term_bad);
 656                         terms->term_bad = xstrdup(argv[i]);
 657                 } else if (skip_prefix(arg, "--term-bad=", &arg) ||
 658                            skip_prefix(arg, "--term-new=", &arg)) {
 659                         must_write_terms = 1;
 660                         free((void *) terms->term_bad);
 661                         terms->term_bad = xstrdup(arg);
 662                 } else if (starts_with(arg, "--")) {
 663                         return error(_("unrecognized option: '%s'"), arg);
 664                 } else if (!get_oidf(&oid, "%s^{commit}", arg)) {
 665                         string_list_append(&revs, oid_to_hex(&oid));
 666                 } else if (has_double_dash) {
 667                         die(_("'%s' does not appear to be a valid "
 668                               "revision"), arg);
 669                 } else {
 670                         break;
 671                 }
 672         }
 673         pathspec_pos = i;
 674
 675         /*
 676          * The user ran "git bisect start <sha1> <sha1>", hence did not
 677          * explicitly specify the terms, but we are already starting to
 678          * set references named with the default terms, and won't be able
 679          * to change afterwards.
 680          */
 681         if (revs.nr)
 682                 must_write_terms = 1;
 683         for (i = 0; i < revs.nr; i++) {
 684                 if (bad_seen) {
 685                         string_list_append(&states, terms->term_good);
 686                 } else {
 687                         bad_seen = 1;
 688                         string_list_append(&states, terms->term_bad);
 689                 }
 690         }
 691
 692         /*
 693          * Verify HEAD
 694          */
 695         head = resolve_ref_unsafe("HEAD", 0, &head_oid, &flags);
 696         if (!head)
 697                 if (get_oid("HEAD", &head_oid))
 698                         return error(_("bad HEAD - I need a HEAD"));
 699
 700         /*
 701          * Check if we are bisecting
 702          */
 703         if (!is_empty_or_missing_file(git_path_bisect_start())) {
 704                 /* Reset to the rev from where we started */
 705                 strbuf_read_file(&start_head, git_path_bisect_start(), 0);
 706                 strbuf_trim(&start_head);
 707                 if (!no_checkout) {
 708                         struct strvec argv = STRVEC_INIT;
 709
 710                         strvec_pushl(&argv, "checkout", start_head.buf,
 711                                      "--", NULL);
 712                         if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 713                                 res = error(_("checking out '%s' failed."
 714                                                  " Try 'git bisect start "
 715                                                  "<valid-branch>'."),
 716                                                start_head.buf);
 717                                 goto finish;
 718                         }
 719                 }
 720         } else {
 721                 /* Get the rev from where we start. */
 722                 if (!get_oid(head, &head_oid) &&
 723                     !starts_with(head, "refs/heads/")) {
 724                         strbuf_reset(&start_head);
 725                         strbuf_addstr(&start_head, oid_to_hex(&head_oid));
 726                 } else if (!get_oid(head, &head_oid) &&
 727                            skip_prefix(head, "refs/heads/", &head)) {
 728                         /*
 729                          * This error message should only be triggered by
 730                          * cogito usage, and cogito users should understand
 731                          * it relates to cg-seek.
 732                          */
 733                         if (!is_empty_or_missing_file(git_path_head_name()))
 734                                 return error(_("won't bisect on cg-seek'ed tree"));
 735                         strbuf_addstr(&start_head, head);
 736                 } else {
 737                         return error(_("bad HEAD - strange symbolic ref"));
 738                 }
 739         }
 740
 741         /*
 742          * Get rid of any old bisect state.
 743          */
 744         if (bisect_clean_state())
 745                 return BISECT_FAILED;
 746
 747         /*
 748          * Write new start state
 749          */
 750         write_file(git_path_bisect_start(), "%s\n", start_head.buf);
 751
 752         if (first_parent_only)
 753                 write_file(git_path_bisect_first_parent(), "\n");
 754
 755         if (no_checkout) {
 756                 if (get_oid(start_head.buf, &oid) < 0) {
 757                         res = error(_("invalid ref: '%s'"), start_head.buf);
 758                         goto finish;
 759                 }
 760                 if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 761                                UPDATE_REFS_MSG_ON_ERR)) {
 762                         res = BISECT_FAILED;
 763                         goto finish;
 764                 }
 765         }
 766
 767         if (pathspec_pos < argc - 1)
 768                 sq_quote_argv(&bisect_names, argv + pathspec_pos);
 769         write_file(git_path_bisect_names(), "%s\n", bisect_names.buf);
 770
 771         for (i = 0; i < states.nr; i++)
 772                 if (bisect_write(states.items[i].string,
 773                                  revs.items[i].string, terms, 1)) {
 774                         res = BISECT_FAILED;
 775                         goto finish;
 776                 }
 777
 778         if (must_write_terms && write_terms(terms->term_bad,
 779                                             terms->term_good)) {
 780                 res = BISECT_FAILED;
 781                 goto finish;
 782         }
 783
 784         res = bisect_append_log_quoted(argv);
 785         if (res)
 786                 res = BISECT_FAILED;
 787
 788 finish:
 789         string_list_clear(&revs, 0);
 790         string_list_clear(&states, 0);
 791         strbuf_release(&start_head);
 792         strbuf_release(&bisect_names);
 793         if (res)
 794                 return res;
 795
 796         res = bisect_auto_next(terms, NULL);
 797         if (!is_bisect_success(res))
 798                 bisect_clean_state();
 799         return res;
 800 }
 801
 802 static inline int file_is_not_empty(const char *path)
 803 {
 804         return !is_empty_or_missing_file(path);
 805 }
 806
 807 static int bisect_autostart(struct bisect_terms *terms)
 808 {
 809         int res;
 810         const char *yesno;
 811
 812         if (file_is_not_empty(git_path_bisect_start()))
 813                 return 0;
 814
 815         fprintf_ln(stderr, _("You need to start by \"git bisect "
 816                           "start\"\n"));
 817
 818         if (!isatty(STDIN_FILENO))
 819                 return -1;
 820
 821         /*
 822          * TRANSLATORS: Make sure to include [Y] and [n] in your
 823          * translation. The program will only accept English input
 824          * at this point.
 825          */
 826         yesno = git_prompt(_("Do you want me to do it for you "
 827                              "[Y/n]? "), PROMPT_ECHO);
 828         res = tolower(*yesno) == 'n' ?
 829                 -1 : bisect_start(terms, empty_strvec, 0);
 830
 831         return res;
 832 }
 833
 834 static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
 835                                       int argc)
 836 {
 837         const char *state;
 838         int i, verify_expected = 1;
 839         struct object_id oid, expected;
 840         struct strbuf buf = STRBUF_INIT;
 841         struct oid_array revs = OID_ARRAY_INIT;
 842
 843         if (!argc)
 844                 return error(_("Please call `--bisect-state` with at least one argument"));
 845
 846         if (bisect_autostart(terms))
 847                 return BISECT_FAILED;
 848
 849         state = argv[0];
 850         if (check_and_set_terms(terms, state) ||
 851             !one_of(state, terms->term_good, terms->term_bad, "skip", NULL))
 852                 return BISECT_FAILED;
 853
 854         argv++;
 855         argc--;
 856         if (argc > 1 && !strcmp(state, terms->term_bad))
 857                 return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
 858
 859         if (argc == 0) {
 860                 const char *head = "BISECT_HEAD";
 861                 enum get_oid_result res_head = get_oid(head, &oid);
 862
 863                 if (res_head == MISSING_OBJECT) {
 864                         head = "HEAD";
 865                         res_head = get_oid(head, &oid);
 866                 }
 867
 868                 if (res_head)
 869                         error(_("Bad rev input: %s"), head);
 870                 oid_array_append(&revs, &oid);
 871         }
 872
 873         /*
 874          * All input revs must be checked before executing bisect_write()
 875          * to discard junk revs.
 876          */
 877
 878         for (; argc; argc--, argv++) {
 879                 struct commit *commit;
 880
 881                 if (get_oid(*argv, &oid)){
 882                         error(_("Bad rev input: %s"), *argv);
 883                         oid_array_clear(&revs);
 884                         return BISECT_FAILED;
 885                 }
 886
 887                 commit = lookup_commit_reference(the_repository, &oid);
 888                 if (!commit)
 889                         die(_("Bad rev input (not a commit): %s"), *argv);
 890
 891                 oid_array_append(&revs, &commit->object.oid);
 892         }
 893
 894         if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
 895             get_oid_hex(buf.buf, &expected) < 0)
 896                 verify_expected = 0; /* Ignore invalid file contents */
 897         strbuf_release(&buf);
 898
 899         for (i = 0; i < revs.nr; i++) {
 900                 if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0)) {
 901                         oid_array_clear(&revs);
 902                         return BISECT_FAILED;
 903                 }
 904                 if (verify_expected && !oideq(&revs.oid[i], &expected)) {
 905                         unlink_or_warn(git_path_bisect_ancestors_ok());
 906                         unlink_or_warn(git_path_bisect_expected_rev());
 907                         verify_expected = 0;
 908                 }
 909         }
 910
 911         oid_array_clear(&revs);
 912         return bisect_auto_next(terms, NULL);
 913 }
 914
 915 static enum bisect_error bisect_log(void)
 916 {
 917         int fd, status;
 918         const char* filename = git_path_bisect_log();
 919
 920         if (is_empty_or_missing_file(filename))
 921                 return error(_("We are not bisecting."));
 922
 923         fd = open(filename, O_RDONLY);
 924         if (fd < 0)
 925                 return BISECT_FAILED;
 926
 927         status = copy_fd(fd, STDOUT_FILENO);
 928         close(fd);
 929         return status ? BISECT_FAILED : BISECT_OK;
 930 }
 931
 932 static int process_replay_line(struct bisect_terms *terms, struct strbuf *line)
 933 {
 934         const char *p = line->buf + strspn(line->buf, " \t");
 935         char *word_end, *rev;
 936
 937         if ((!skip_prefix(p, "git bisect", &p) &&
 938         !skip_prefix(p, "git-bisect", &p)) || !isspace(*p))
 939                 return 0;
 940         p += strspn(p, " \t");
 941
 942         word_end = (char *)p + strcspn(p, " \t");
 943         rev = word_end + strspn(word_end, " \t");
 944         *word_end = '\0'; /* NUL-terminate the word */
 945
 946         get_terms(terms);
 947         if (check_and_set_terms(terms, p))
 948                 return -1;
 949
 950         if (!strcmp(p, "start")) {
 951                 struct strvec argv = STRVEC_INIT;
 952                 int res;
 953                 sq_dequote_to_strvec(rev, &argv);
 954                 res = bisect_start(terms, argv.v, argv.nr);
 955                 strvec_clear(&argv);
 956                 return res;
 957         }
 958
 959         if (one_of(p, terms->term_good,
 960            terms->term_bad, "skip", NULL))
 961                 return bisect_write(p, rev, terms, 0);
 962
 963         if (!strcmp(p, "terms")) {
 964                 struct strvec argv = STRVEC_INIT;
 965                 int res;
 966                 sq_dequote_to_strvec(rev, &argv);
 967                 res = bisect_terms(terms, argv.nr == 1 ? argv.v[0] : NULL);
 968                 strvec_clear(&argv);
 969                 return res;
 970         }
 971         error(_("'%s'?? what are you talking about?"), p);
 972
 973         return -1;
 974 }
 975
 976 static enum bisect_error bisect_replay(struct bisect_terms *terms, const char *filename)
 977 {
 978         FILE *fp = NULL;
 979         enum bisect_error res = BISECT_OK;
 980         struct strbuf line = STRBUF_INIT;
 981
 982         if (is_empty_or_missing_file(filename))
 983                 return error(_("cannot read file '%s' for replaying"), filename);
 984
 985         if (bisect_reset(NULL))
 986                 return BISECT_FAILED;
 987
 988         fp = fopen(filename, "r");
 989         if (!fp)
 990                 return BISECT_FAILED;
 991
 992         while ((strbuf_getline(&line, fp) != EOF) && !res)
 993                 res = process_replay_line(terms, &line);
 994
 995         strbuf_release(&line);
 996         fclose(fp);
 997
 998         if (res)
 999                 return BISECT_FAILED;
1000
1001         return bisect_auto_next(terms, NULL);
1002 }
1003
1004 static enum bisect_error bisect_skip(struct bisect_terms *terms, const char **argv, int argc)
1005 {
1006         int i;
1007         enum bisect_error res;
1008         struct strvec argv_state = STRVEC_INIT;
1009
1010         strvec_push(&argv_state, "skip");
1011
1012         for (i = 0; i < argc; i++) {
1013                 const char *dotdot = strstr(argv[i], "..");
1014
1015                 if (dotdot) {
1016                         struct rev_info revs;
1017                         struct commit *commit;
1018
1019                         init_revisions(&revs, NULL);
1020                         setup_revisions(2, argv + i - 1, &revs, NULL);
1021
1022                         if (prepare_revision_walk(&revs))
1023                                 die(_("revision walk setup failed\n"));
1024                         while ((commit = get_revision(&revs)) != NULL)
1025                                 strvec_push(&argv_state,
1026                                                 oid_to_hex(&commit->object.oid));
1027
1028                         reset_revision_walk();
1029                 } else {
1030                         strvec_push(&argv_state, argv[i]);
1031                 }
1032         }
1033         res = bisect_state(terms, argv_state.v, argv_state.nr);
1034
1035         strvec_clear(&argv_state);
1036         return res;
1037 }
1038
1039 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
1040 {
1041         enum {
1042                 BISECT_RESET = 1,
1043                 BISECT_NEXT_CHECK,
1044                 BISECT_TERMS,
1045                 BISECT_START,
1046                 BISECT_AUTOSTART,
1047                 BISECT_NEXT,
1048                 BISECT_STATE,
1049                 BISECT_LOG,
1050                 BISECT_REPLAY,
1051                 BISECT_SKIP
1052         } cmdmode = 0;
1053         int res = 0, nolog = 0;
1054         struct option options[] = {
1055                 OPT_CMDMODE(0, "bisect-reset", &cmdmode,
1056                          N_("reset the bisection state"), BISECT_RESET),
1057                 OPT_CMDMODE(0, "bisect-next-check", &cmdmode,
1058                          N_("check whether bad or good terms exist"), BISECT_NEXT_CHECK),
1059                 OPT_CMDMODE(0, "bisect-terms", &cmdmode,
1060                          N_("print out the bisect terms"), BISECT_TERMS),
1061                 OPT_CMDMODE(0, "bisect-start", &cmdmode,
1062                          N_("start the bisect session"), BISECT_START),
1063                 OPT_CMDMODE(0, "bisect-next", &cmdmode,
1064                          N_("find the next bisection commit"), BISECT_NEXT),
1065                 OPT_CMDMODE(0, "bisect-state", &cmdmode,
1066                          N_("mark the state of ref (or refs)"), BISECT_STATE),
1067                 OPT_CMDMODE(0, "bisect-log", &cmdmode,
1068                          N_("list the bisection steps so far"), BISECT_LOG),
1069                 OPT_CMDMODE(0, "bisect-replay", &cmdmode,
1070                          N_("replay the bisection process from the given file"), BISECT_REPLAY),
1071                 OPT_CMDMODE(0, "bisect-skip", &cmdmode,
1072                          N_("skip some commits for checkout"), BISECT_SKIP),
1073                 OPT_BOOL(0, "no-log", &nolog,
1074                          N_("no log for BISECT_WRITE")),
1075                 OPT_END()
1076         };
1077         struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
1078
1079         argc = parse_options(argc, argv, prefix, options,
1080                              git_bisect_helper_usage,
1081                              PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN);
1082
1083         if (!cmdmode)
1084                 usage_with_options(git_bisect_helper_usage, options);
1085
1086         switch (cmdmode) {
1087         case BISECT_RESET:
1088                 if (argc > 1)
1089                         return error(_("--bisect-reset requires either no argument or a commit"));
1090                 res = bisect_reset(argc ? argv[0] : NULL);
1091                 break;
1092         case BISECT_NEXT_CHECK:
1093                 if (argc != 2 && argc != 3)
1094                         return error(_("--bisect-next-check requires 2 or 3 arguments"));
1095                 set_terms(&terms, argv[1], argv[0]);
1096                 res = bisect_next_check(&terms, argc == 3 ? argv[2] : NULL);
1097                 break;
1098         case BISECT_TERMS:
1099                 if (argc > 1)
1100                         return error(_("--bisect-terms requires 0 or 1 argument"));
1101                 res = bisect_terms(&terms, argc == 1 ? argv[0] : NULL);
1102                 break;
1103         case BISECT_START:
1104                 set_terms(&terms, "bad", "good");
1105                 res = bisect_start(&terms, argv, argc);
1106                 break;
1107         case BISECT_NEXT:
1108                 if (argc)
1109                         return error(_("--bisect-next requires 0 arguments"));
1110                 get_terms(&terms);
1111                 res = bisect_next(&terms, prefix);
1112                 break;
1113         case BISECT_STATE:
1114                 set_terms(&terms, "bad", "good");
1115                 get_terms(&terms);
1116                 res = bisect_state(&terms, argv, argc);
1117                 break;
1118         case BISECT_LOG:
1119                 if (argc)
1120                         return error(_("--bisect-log requires 0 arguments"));
1121                 res = bisect_log();
1122                 break;
1123         case BISECT_REPLAY:
1124                 if (argc != 1)
1125                         return error(_("no logfile given"));
1126                 set_terms(&terms, "bad", "good");
1127                 res = bisect_replay(&terms, argv[0]);
1128                 break;
1129         case BISECT_SKIP:
1130                 set_terms(&terms, "bad", "good");
1131                 get_terms(&terms);
1132                 res = bisect_skip(&terms, argv, argc);
1133                 break;
1134         default:
1135                 BUG("unknown subcommand %d", cmdmode);
1136         }
1137         free_terms(&terms);
1138
1139         /*
1140          * Handle early success
1141          * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
1142          */
1143         if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
1144                 res = BISECT_OK;
1145
1146         return -res;
1147 }