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 static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
  22
  23 static const char * const git_bisect_helper_usage[] = {
  24         N_("git bisect--helper --bisect-reset [<commit>]"),
  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         N_("git bisect--helper --bisect-visualize"),
  34         N_("git bisect--helper --bisect-run <cmd>..."),
  35         NULL
  36 };
  37
  38 struct add_bisect_ref_data {
  39         struct rev_info *revs;
  40         unsigned int object_flags;
  41 };
  42
  43 struct bisect_terms {
  44         char *term_good;
  45         char *term_bad;
  46 };
  47
  48 static void free_terms(struct bisect_terms *terms)
  49 {
  50         FREE_AND_NULL(terms->term_good);
  51         FREE_AND_NULL(terms->term_bad);
  52 }
  53
  54 static void set_terms(struct bisect_terms *terms, const char *bad,
  55                       const char *good)
  56 {
  57         free((void *)terms->term_good);
  58         terms->term_good = xstrdup(good);
  59         free((void *)terms->term_bad);
  60         terms->term_bad = xstrdup(bad);
  61 }
  62
  63 static const char vocab_bad[] = "bad|new";
  64 static const char vocab_good[] = "good|old";
  65
  66 static int bisect_autostart(struct bisect_terms *terms);
  67
  68 /*
  69  * Check whether the string `term` belongs to the set of strings
  70  * included in the variable arguments.
  71  */
  72 LAST_ARG_MUST_BE_NULL
  73 static int one_of(const char *term, ...)
  74 {
  75         int res = 0;
  76         va_list matches;
  77         const char *match;
  78
  79         va_start(matches, term);
  80         while (!res && (match = va_arg(matches, const char *)))
  81                 res = !strcmp(term, match);
  82         va_end(matches);
  83
  84         return res;
  85 }
  86
  87 /*
  88  * return code BISECT_INTERNAL_SUCCESS_MERGE_BASE
  89  * and BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND are codes
  90  * that indicate special success.
  91  */
  92
  93 static int is_bisect_success(enum bisect_error res)
  94 {
  95         return !res ||
  96                 res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND ||
  97                 res == BISECT_INTERNAL_SUCCESS_MERGE_BASE;
  98 }
  99
 100 static int write_in_file(const char *path, const char *mode, const char *format, va_list args)
 101 {
 102         FILE *fp = NULL;
 103         int res = 0;
 104
 105         if (strcmp(mode, "w") && strcmp(mode, "a"))
 106                 BUG("write-in-file does not support '%s' mode", mode);
 107         fp = fopen(path, mode);
 108         if (!fp)
 109                 return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
 110         res = vfprintf(fp, format, args);
 111
 112         if (res < 0) {
 113                 int saved_errno = errno;
 114                 fclose(fp);
 115                 errno = saved_errno;
 116                 return error_errno(_("could not write to file '%s'"), path);
 117         }
 118
 119         return fclose(fp);
 120 }
 121
 122 __attribute__((format (printf, 2, 3)))
 123 static int write_to_file(const char *path, const char *format, ...)
 124 {
 125         int res;
 126         va_list args;
 127
 128         va_start(args, format);
 129         res = write_in_file(path, "w", format, args);
 130         va_end(args);
 131
 132         return res;
 133 }
 134
 135 __attribute__((format (printf, 2, 3)))
 136 static int append_to_file(const char *path, const char *format, ...)
 137 {
 138         int res;
 139         va_list args;
 140
 141         va_start(args, format);
 142         res = write_in_file(path, "a", format, args);
 143         va_end(args);
 144
 145         return res;
 146 }
 147
 148 static int print_file_to_stdout(const char *path)
 149 {
 150         int fd = open(path, O_RDONLY);
 151         int ret = 0;
 152
 153         if (fd < 0)
 154                 return error_errno(_("cannot open file '%s' for reading"), path);
 155         if (copy_fd(fd, 1) < 0)
 156                 ret = error_errno(_("failed to read '%s'"), path);
 157         close(fd);
 158         return ret;
 159 }
 160
 161 static int check_term_format(const char *term, const char *orig_term)
 162 {
 163         int res;
 164         char *new_term = xstrfmt("refs/bisect/%s", term);
 165
 166         res = check_refname_format(new_term, 0);
 167         free(new_term);
 168
 169         if (res)
 170                 return error(_("'%s' is not a valid term"), term);
 171
 172         if (one_of(term, "help", "start", "skip", "next", "reset",
 173                         "visualize", "view", "replay", "log", "run", "terms", NULL))
 174                 return error(_("can't use the builtin command '%s' as a term"), term);
 175
 176         /*
 177          * In theory, nothing prevents swapping completely good and bad,
 178          * but this situation could be confusing and hasn't been tested
 179          * enough. Forbid it for now.
 180          */
 181
 182         if ((strcmp(orig_term, "bad") && one_of(term, "bad", "new", NULL)) ||
 183                  (strcmp(orig_term, "good") && one_of(term, "good", "old", NULL)))
 184                 return error(_("can't change the meaning of the term '%s'"), term);
 185
 186         return 0;
 187 }
 188
 189 static int write_terms(const char *bad, const char *good)
 190 {
 191         int res;
 192
 193         if (!strcmp(bad, good))
 194                 return error(_("please use two different terms"));
 195
 196         if (check_term_format(bad, "bad") || check_term_format(good, "good"))
 197                 return -1;
 198
 199         res = write_to_file(git_path_bisect_terms(), "%s\n%s\n", bad, good);
 200
 201         return res;
 202 }
 203
 204 static int bisect_reset(const char *commit)
 205 {
 206         struct strbuf branch = STRBUF_INIT;
 207
 208         if (!commit) {
 209                 if (strbuf_read_file(&branch, git_path_bisect_start(), 0) < 1) {
 210                         printf(_("We are not bisecting.\n"));
 211                         return 0;
 212                 }
 213                 strbuf_rtrim(&branch);
 214         } else {
 215                 struct object_id oid;
 216
 217                 if (get_oid_commit(commit, &oid))
 218                         return error(_("'%s' is not a valid commit"), commit);
 219                 strbuf_addstr(&branch, commit);
 220         }
 221
 222         if (!ref_exists("BISECT_HEAD")) {
 223                 struct strvec argv = STRVEC_INIT;
 224
 225                 strvec_pushl(&argv, "checkout", branch.buf, "--", NULL);
 226                 if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 227                         error(_("could not check out original"
 228                                 " HEAD '%s'. Try 'git bisect"
 229                                 " reset <commit>'."), branch.buf);
 230                         strbuf_release(&branch);
 231                         strvec_clear(&argv);
 232                         return -1;
 233                 }
 234                 strvec_clear(&argv);
 235         }
 236
 237         strbuf_release(&branch);
 238         return bisect_clean_state();
 239 }
 240
 241 static void log_commit(FILE *fp, char *fmt, const char *state,
 242                        struct commit *commit)
 243 {
 244         struct pretty_print_context pp = {0};
 245         struct strbuf commit_msg = STRBUF_INIT;
 246         char *label = xstrfmt(fmt, state);
 247
 248         format_commit_message(commit, "%s", &commit_msg, &pp);
 249
 250         fprintf(fp, "# %s: [%s] %s\n", label, oid_to_hex(&commit->object.oid),
 251                 commit_msg.buf);
 252
 253         strbuf_release(&commit_msg);
 254         free(label);
 255 }
 256
 257 static int bisect_write(const char *state, const char *rev,
 258                         const struct bisect_terms *terms, int nolog)
 259 {
 260         struct strbuf tag = STRBUF_INIT;
 261         struct object_id oid;
 262         struct commit *commit;
 263         FILE *fp = NULL;
 264         int res = 0;
 265
 266         if (!strcmp(state, terms->term_bad)) {
 267                 strbuf_addf(&tag, "refs/bisect/%s", state);
 268         } else if (one_of(state, terms->term_good, "skip", NULL)) {
 269                 strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
 270         } else {
 271                 res = error(_("Bad bisect_write argument: %s"), state);
 272                 goto finish;
 273         }
 274
 275         if (get_oid(rev, &oid)) {
 276                 res = error(_("couldn't get the oid of the rev '%s'"), rev);
 277                 goto finish;
 278         }
 279
 280         if (update_ref(NULL, tag.buf, &oid, NULL, 0,
 281                        UPDATE_REFS_MSG_ON_ERR)) {
 282                 res = -1;
 283                 goto finish;
 284         }
 285
 286         fp = fopen(git_path_bisect_log(), "a");
 287         if (!fp) {
 288                 res = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
 289                 goto finish;
 290         }
 291
 292         commit = lookup_commit_reference(the_repository, &oid);
 293         log_commit(fp, "%s", state, commit);
 294
 295         if (!nolog)
 296                 fprintf(fp, "git bisect %s %s\n", state, rev);
 297
 298 finish:
 299         if (fp)
 300                 fclose(fp);
 301         strbuf_release(&tag);
 302         return res;
 303 }
 304
 305 static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
 306 {
 307         int has_term_file = !is_empty_or_missing_file(git_path_bisect_terms());
 308
 309         if (one_of(cmd, "skip", "start", "terms", NULL))
 310                 return 0;
 311
 312         if (has_term_file && strcmp(cmd, terms->term_bad) &&
 313             strcmp(cmd, terms->term_good))
 314                 return error(_("Invalid command: you're currently in a "
 315                                 "%s/%s bisect"), terms->term_bad,
 316                                 terms->term_good);
 317
 318         if (!has_term_file) {
 319                 if (one_of(cmd, "bad", "good", NULL)) {
 320                         set_terms(terms, "bad", "good");
 321                         return write_terms(terms->term_bad, terms->term_good);
 322                 }
 323                 if (one_of(cmd, "new", "old", NULL)) {
 324                         set_terms(terms, "new", "old");
 325                         return write_terms(terms->term_bad, terms->term_good);
 326                 }
 327         }
 328
 329         return 0;
 330 }
 331
 332 static int mark_good(const char *refname, const struct object_id *oid,
 333                      int flag, void *cb_data)
 334 {
 335         int *m_good = (int *)cb_data;
 336         *m_good = 0;
 337         return 1;
 338 }
 339
 340 static const char need_bad_and_good_revision_warning[] =
 341         N_("You need to give me at least one %s and %s revision.\n"
 342            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 343
 344 static const char need_bisect_start_warning[] =
 345         N_("You need to start by \"git bisect start\".\n"
 346            "You then need to give me at least one %s and %s revision.\n"
 347            "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 348
 349 static int decide_next(const struct bisect_terms *terms,
 350                        const char *current_term, int missing_good,
 351                        int missing_bad)
 352 {
 353         if (!missing_good && !missing_bad)
 354                 return 0;
 355         if (!current_term)
 356                 return -1;
 357
 358         if (missing_good && !missing_bad &&
 359             !strcmp(current_term, terms->term_good)) {
 360                 char *yesno;
 361                 /*
 362                  * have bad (or new) but not good (or old). We could bisect
 363                  * although this is less optimum.
 364                  */
 365                 warning(_("bisecting only with a %s commit"), terms->term_bad);
 366                 if (!isatty(0))
 367                         return 0;
 368                 /*
 369                  * TRANSLATORS: Make sure to include [Y] and [n] in your
 370                  * translation. The program will only accept English input
 371                  * at this point.
 372                  */
 373                 yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
 374                 if (starts_with(yesno, "N") || starts_with(yesno, "n"))
 375                         return -1;
 376                 return 0;
 377         }
 378
 379         if (!is_empty_or_missing_file(git_path_bisect_start()))
 380                 return error(_(need_bad_and_good_revision_warning),
 381                              vocab_bad, vocab_good, vocab_bad, vocab_good);
 382         else
 383                 return error(_(need_bisect_start_warning),
 384                              vocab_good, vocab_bad, vocab_good, vocab_bad);
 385 }
 386
 387 static int bisect_next_check(const struct bisect_terms *terms,
 388                              const char *current_term)
 389 {
 390         int missing_good = 1, missing_bad = 1;
 391         char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
 392         char *good_glob = xstrfmt("%s-*", terms->term_good);
 393
 394         if (ref_exists(bad_ref))
 395                 missing_bad = 0;
 396
 397         for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
 398                              (void *) &missing_good);
 399
 400         free(good_glob);
 401         free(bad_ref);
 402
 403         return decide_next(terms, current_term, missing_good, missing_bad);
 404 }
 405
 406 static int get_terms(struct bisect_terms *terms)
 407 {
 408         struct strbuf str = STRBUF_INIT;
 409         FILE *fp = NULL;
 410         int res = 0;
 411
 412         fp = fopen(git_path_bisect_terms(), "r");
 413         if (!fp) {
 414                 res = -1;
 415                 goto finish;
 416         }
 417
 418         free_terms(terms);
 419         strbuf_getline_lf(&str, fp);
 420         terms->term_bad = strbuf_detach(&str, NULL);
 421         strbuf_getline_lf(&str, fp);
 422         terms->term_good = strbuf_detach(&str, NULL);
 423
 424 finish:
 425         if (fp)
 426                 fclose(fp);
 427         strbuf_release(&str);
 428         return res;
 429 }
 430
 431 static int bisect_terms(struct bisect_terms *terms, const char *option)
 432 {
 433         if (get_terms(terms))
 434                 return error(_("no terms defined"));
 435
 436         if (option == NULL) {
 437                 printf(_("Your current terms are %s for the old state\n"
 438                          "and %s for the new state.\n"),
 439                        terms->term_good, terms->term_bad);
 440                 return 0;
 441         }
 442         if (one_of(option, "--term-good", "--term-old", NULL))
 443                 printf("%s\n", terms->term_good);
 444         else if (one_of(option, "--term-bad", "--term-new", NULL))
 445                 printf("%s\n", terms->term_bad);
 446         else
 447                 return error(_("invalid argument %s for 'git bisect terms'.\n"
 448                                "Supported options are: "
 449                                "--term-good|--term-old and "
 450                                "--term-bad|--term-new."), option);
 451
 452         return 0;
 453 }
 454
 455 static int bisect_append_log_quoted(const char **argv)
 456 {
 457         int res = 0;
 458         FILE *fp = fopen(git_path_bisect_log(), "a");
 459         struct strbuf orig_args = STRBUF_INIT;
 460
 461         if (!fp)
 462                 return -1;
 463
 464         if (fprintf(fp, "git bisect start") < 1) {
 465                 res = -1;
 466                 goto finish;
 467         }
 468
 469         sq_quote_argv(&orig_args, argv);
 470         if (fprintf(fp, "%s\n", orig_args.buf) < 1)
 471                 res = -1;
 472
 473 finish:
 474         fclose(fp);
 475         strbuf_release(&orig_args);
 476         return res;
 477 }
 478
 479 static int add_bisect_ref(const char *refname, const struct object_id *oid,
 480                           int flags, void *cb)
 481 {
 482         struct add_bisect_ref_data *data = cb;
 483
 484         add_pending_oid(data->revs, refname, oid, data->object_flags);
 485
 486         return 0;
 487 }
 488
 489 static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
 490 {
 491         int res = 0;
 492         struct add_bisect_ref_data cb = { revs };
 493         char *good = xstrfmt("%s-*", terms->term_good);
 494
 495         /*
 496          * We cannot use terms->term_bad directly in
 497          * for_each_glob_ref_in() and we have to append a '*' to it,
 498          * otherwise for_each_glob_ref_in() will append '/' and '*'.
 499          */
 500         char *bad = xstrfmt("%s*", terms->term_bad);
 501
 502         /*
 503          * It is important to reset the flags used by revision walks
 504          * as the previous call to bisect_next_all() in turn
 505          * sets up a revision walk.
 506          */
 507         reset_revision_walk();
 508         init_revisions(revs, NULL);
 509         setup_revisions(0, NULL, revs, NULL);
 510         for_each_glob_ref_in(add_bisect_ref, bad, "refs/bisect/", &cb);
 511         cb.object_flags = UNINTERESTING;
 512         for_each_glob_ref_in(add_bisect_ref, good, "refs/bisect/", &cb);
 513         if (prepare_revision_walk(revs))
 514                 res = error(_("revision walk setup failed\n"));
 515
 516         free(good);
 517         free(bad);
 518         return res;
 519 }
 520
 521 static int bisect_skipped_commits(struct bisect_terms *terms)
 522 {
 523         int res;
 524         FILE *fp = NULL;
 525         struct rev_info revs;
 526         struct commit *commit;
 527         struct pretty_print_context pp = {0};
 528         struct strbuf commit_name = STRBUF_INIT;
 529
 530         res = prepare_revs(terms, &revs);
 531         if (res)
 532                 return res;
 533
 534         fp = fopen(git_path_bisect_log(), "a");
 535         if (!fp)
 536                 return error_errno(_("could not open '%s' for appending"),
 537                                   git_path_bisect_log());
 538
 539         if (fprintf(fp, "# only skipped commits left to test\n") < 0)
 540                 return error_errno(_("failed to write to '%s'"), git_path_bisect_log());
 541
 542         while ((commit = get_revision(&revs)) != NULL) {
 543                 strbuf_reset(&commit_name);
 544                 format_commit_message(commit, "%s",
 545                                       &commit_name, &pp);
 546                 fprintf(fp, "# possible first %s commit: [%s] %s\n",
 547                         terms->term_bad, oid_to_hex(&commit->object.oid),
 548                         commit_name.buf);
 549         }
 550
 551         /*
 552          * Reset the flags used by revision walks in case
 553          * there is another revision walk after this one.
 554          */
 555         reset_revision_walk();
 556
 557         strbuf_release(&commit_name);
 558         fclose(fp);
 559         return 0;
 560 }
 561
 562 static int bisect_successful(struct bisect_terms *terms)
 563 {
 564         struct object_id oid;
 565         struct commit *commit;
 566         struct pretty_print_context pp = {0};
 567         struct strbuf commit_name = STRBUF_INIT;
 568         char *bad_ref = xstrfmt("refs/bisect/%s",terms->term_bad);
 569         int res;
 570
 571         read_ref(bad_ref, &oid);
 572         commit = lookup_commit_reference_by_name(bad_ref);
 573         format_commit_message(commit, "%s", &commit_name, &pp);
 574
 575         res = append_to_file(git_path_bisect_log(), "# first %s commit: [%s] %s\n",
 576                             terms->term_bad, oid_to_hex(&commit->object.oid),
 577                             commit_name.buf);
 578
 579         strbuf_release(&commit_name);
 580         free(bad_ref);
 581         return res;
 582 }
 583
 584 static enum bisect_error bisect_next(struct bisect_terms *terms, const char *prefix)
 585 {
 586         enum bisect_error res;
 587
 588         if (bisect_autostart(terms))
 589                 return BISECT_FAILED;
 590
 591         if (bisect_next_check(terms, terms->term_good))
 592                 return BISECT_FAILED;
 593
 594         /* Perform all bisection computation */
 595         res = bisect_next_all(the_repository, prefix);
 596
 597         if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
 598                 res = bisect_successful(terms);
 599                 return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
 600         } else if (res == BISECT_ONLY_SKIPPED_LEFT) {
 601                 res = bisect_skipped_commits(terms);
 602                 return res ? res : BISECT_ONLY_SKIPPED_LEFT;
 603         }
 604         return res;
 605 }
 606
 607 static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char *prefix)
 608 {
 609         if (bisect_next_check(terms, NULL))
 610                 return BISECT_OK;
 611
 612         return bisect_next(terms, prefix);
 613 }
 614
 615 static enum bisect_error bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 616 {
 617         int no_checkout = 0;
 618         int first_parent_only = 0;
 619         int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 620         int flags, pathspec_pos;
 621         enum bisect_error res = BISECT_OK;
 622         struct string_list revs = STRING_LIST_INIT_DUP;
 623         struct string_list states = STRING_LIST_INIT_DUP;
 624         struct strbuf start_head = STRBUF_INIT;
 625         struct strbuf bisect_names = STRBUF_INIT;
 626         struct object_id head_oid;
 627         struct object_id oid;
 628         const char *head;
 629
 630         if (is_bare_repository())
 631                 no_checkout = 1;
 632
 633         /*
 634          * Check for one bad and then some good revisions
 635          */
 636         for (i = 0; i < argc; i++) {
 637                 if (!strcmp(argv[i], "--")) {
 638                         has_double_dash = 1;
 639                         break;
 640                 }
 641         }
 642
 643         for (i = 0; i < argc; i++) {
 644                 const char *arg = argv[i];
 645                 if (!strcmp(argv[i], "--")) {
 646                         break;
 647                 } else if (!strcmp(arg, "--no-checkout")) {
 648                         no_checkout = 1;
 649                 } else if (!strcmp(arg, "--first-parent")) {
 650                         first_parent_only = 1;
 651                 } else if (!strcmp(arg, "--term-good") ||
 652                          !strcmp(arg, "--term-old")) {
 653                         i++;
 654                         if (argc <= i)
 655                                 return error(_("'' is not a valid term"));
 656                         must_write_terms = 1;
 657                         free((void *) terms->term_good);
 658                         terms->term_good = xstrdup(argv[i]);
 659                 } else if (skip_prefix(arg, "--term-good=", &arg) ||
 660                            skip_prefix(arg, "--term-old=", &arg)) {
 661                         must_write_terms = 1;
 662                         free((void *) terms->term_good);
 663                         terms->term_good = xstrdup(arg);
 664                 } else if (!strcmp(arg, "--term-bad") ||
 665                          !strcmp(arg, "--term-new")) {
 666                         i++;
 667                         if (argc <= i)
 668                                 return error(_("'' is not a valid term"));
 669                         must_write_terms = 1;
 670                         free((void *) terms->term_bad);
 671                         terms->term_bad = xstrdup(argv[i]);
 672                 } else if (skip_prefix(arg, "--term-bad=", &arg) ||
 673                            skip_prefix(arg, "--term-new=", &arg)) {
 674                         must_write_terms = 1;
 675                         free((void *) terms->term_bad);
 676                         terms->term_bad = xstrdup(arg);
 677                 } else if (starts_with(arg, "--")) {
 678                         return error(_("unrecognized option: '%s'"), arg);
 679                 } else if (!get_oidf(&oid, "%s^{commit}", arg)) {
 680                         string_list_append(&revs, oid_to_hex(&oid));
 681                 } else if (has_double_dash) {
 682                         die(_("'%s' does not appear to be a valid "
 683                               "revision"), arg);
 684                 } else {
 685                         break;
 686                 }
 687         }
 688         pathspec_pos = i;
 689
 690         /*
 691          * The user ran "git bisect start <sha1> <sha1>", hence did not
 692          * explicitly specify the terms, but we are already starting to
 693          * set references named with the default terms, and won't be able
 694          * to change afterwards.
 695          */
 696         if (revs.nr)
 697                 must_write_terms = 1;
 698         for (i = 0; i < revs.nr; i++) {
 699                 if (bad_seen) {
 700                         string_list_append(&states, terms->term_good);
 701                 } else {
 702                         bad_seen = 1;
 703                         string_list_append(&states, terms->term_bad);
 704                 }
 705         }
 706
 707         /*
 708          * Verify HEAD
 709          */
 710         head = resolve_ref_unsafe("HEAD", 0, &head_oid, &flags);
 711         if (!head)
 712                 if (get_oid("HEAD", &head_oid))
 713                         return error(_("bad HEAD - I need a HEAD"));
 714
 715         /*
 716          * Check if we are bisecting
 717          */
 718         if (!is_empty_or_missing_file(git_path_bisect_start())) {
 719                 /* Reset to the rev from where we started */
 720                 strbuf_read_file(&start_head, git_path_bisect_start(), 0);
 721                 strbuf_trim(&start_head);
 722                 if (!no_checkout) {
 723                         struct strvec argv = STRVEC_INIT;
 724
 725                         strvec_pushl(&argv, "checkout", start_head.buf,
 726                                      "--", NULL);
 727                         if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 728                                 res = error(_("checking out '%s' failed."
 729                                                  " Try 'git bisect start "
 730                                                  "<valid-branch>'."),
 731                                                start_head.buf);
 732                                 goto finish;
 733                         }
 734                 }
 735         } else {
 736                 /* Get the rev from where we start. */
 737                 if (!get_oid(head, &head_oid) &&
 738                     !starts_with(head, "refs/heads/")) {
 739                         strbuf_reset(&start_head);
 740                         strbuf_addstr(&start_head, oid_to_hex(&head_oid));
 741                 } else if (!get_oid(head, &head_oid) &&
 742                            skip_prefix(head, "refs/heads/", &head)) {
 743                         /*
 744                          * This error message should only be triggered by
 745                          * cogito usage, and cogito users should understand
 746                          * it relates to cg-seek.
 747                          */
 748                         if (!is_empty_or_missing_file(git_path_head_name()))
 749                                 return error(_("won't bisect on cg-seek'ed tree"));
 750                         strbuf_addstr(&start_head, head);
 751                 } else {
 752                         return error(_("bad HEAD - strange symbolic ref"));
 753                 }
 754         }
 755
 756         /*
 757          * Get rid of any old bisect state.
 758          */
 759         if (bisect_clean_state())
 760                 return BISECT_FAILED;
 761
 762         /*
 763          * Write new start state
 764          */
 765         write_file(git_path_bisect_start(), "%s\n", start_head.buf);
 766
 767         if (first_parent_only)
 768                 write_file(git_path_bisect_first_parent(), "\n");
 769
 770         if (no_checkout) {
 771                 if (get_oid(start_head.buf, &oid) < 0) {
 772                         res = error(_("invalid ref: '%s'"), start_head.buf);
 773                         goto finish;
 774                 }
 775                 if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 776                                UPDATE_REFS_MSG_ON_ERR)) {
 777                         res = BISECT_FAILED;
 778                         goto finish;
 779                 }
 780         }
 781
 782         if (pathspec_pos < argc - 1)
 783                 sq_quote_argv(&bisect_names, argv + pathspec_pos);
 784         write_file(git_path_bisect_names(), "%s\n", bisect_names.buf);
 785
 786         for (i = 0; i < states.nr; i++)
 787                 if (bisect_write(states.items[i].string,
 788                                  revs.items[i].string, terms, 1)) {
 789                         res = BISECT_FAILED;
 790                         goto finish;
 791                 }
 792
 793         if (must_write_terms && write_terms(terms->term_bad,
 794                                             terms->term_good)) {
 795                 res = BISECT_FAILED;
 796                 goto finish;
 797         }
 798
 799         res = bisect_append_log_quoted(argv);
 800         if (res)
 801                 res = BISECT_FAILED;
 802
 803 finish:
 804         string_list_clear(&revs, 0);
 805         string_list_clear(&states, 0);
 806         strbuf_release(&start_head);
 807         strbuf_release(&bisect_names);
 808         if (res)
 809                 return res;
 810
 811         res = bisect_auto_next(terms, NULL);
 812         if (!is_bisect_success(res))
 813                 bisect_clean_state();
 814         return res;
 815 }
 816
 817 static inline int file_is_not_empty(const char *path)
 818 {
 819         return !is_empty_or_missing_file(path);
 820 }
 821
 822 static int bisect_autostart(struct bisect_terms *terms)
 823 {
 824         int res;
 825         const char *yesno;
 826
 827         if (file_is_not_empty(git_path_bisect_start()))
 828                 return 0;
 829
 830         fprintf_ln(stderr, _("You need to start by \"git bisect "
 831                           "start\"\n"));
 832
 833         if (!isatty(STDIN_FILENO))
 834                 return -1;
 835
 836         /*
 837          * TRANSLATORS: Make sure to include [Y] and [n] in your
 838          * translation. The program will only accept English input
 839          * at this point.
 840          */
 841         yesno = git_prompt(_("Do you want me to do it for you "
 842                              "[Y/n]? "), PROMPT_ECHO);
 843         res = tolower(*yesno) == 'n' ?
 844                 -1 : bisect_start(terms, empty_strvec, 0);
 845
 846         return res;
 847 }
 848
 849 static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
 850                                       int argc)
 851 {
 852         const char *state;
 853         int i, verify_expected = 1;
 854         struct object_id oid, expected;
 855         struct strbuf buf = STRBUF_INIT;
 856         struct oid_array revs = OID_ARRAY_INIT;
 857
 858         if (!argc)
 859                 return error(_("Please call `--bisect-state` with at least one argument"));
 860
 861         if (bisect_autostart(terms))
 862                 return BISECT_FAILED;
 863
 864         state = argv[0];
 865         if (check_and_set_terms(terms, state) ||
 866             !one_of(state, terms->term_good, terms->term_bad, "skip", NULL))
 867                 return BISECT_FAILED;
 868
 869         argv++;
 870         argc--;
 871         if (argc > 1 && !strcmp(state, terms->term_bad))
 872                 return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
 873
 874         if (argc == 0) {
 875                 const char *head = "BISECT_HEAD";
 876                 enum get_oid_result res_head = get_oid(head, &oid);
 877
 878                 if (res_head == MISSING_OBJECT) {
 879                         head = "HEAD";
 880                         res_head = get_oid(head, &oid);
 881                 }
 882
 883                 if (res_head)
 884                         error(_("Bad rev input: %s"), head);
 885                 oid_array_append(&revs, &oid);
 886         }
 887
 888         /*
 889          * All input revs must be checked before executing bisect_write()
 890          * to discard junk revs.
 891          */
 892
 893         for (; argc; argc--, argv++) {
 894                 struct commit *commit;
 895
 896                 if (get_oid(*argv, &oid)){
 897                         error(_("Bad rev input: %s"), *argv);
 898                         oid_array_clear(&revs);
 899                         return BISECT_FAILED;
 900                 }
 901
 902                 commit = lookup_commit_reference(the_repository, &oid);
 903                 if (!commit)
 904                         die(_("Bad rev input (not a commit): %s"), *argv);
 905
 906                 oid_array_append(&revs, &commit->object.oid);
 907         }
 908
 909         if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
 910             get_oid_hex(buf.buf, &expected) < 0)
 911                 verify_expected = 0; /* Ignore invalid file contents */
 912         strbuf_release(&buf);
 913
 914         for (i = 0; i < revs.nr; i++) {
 915                 if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0)) {
 916                         oid_array_clear(&revs);
 917                         return BISECT_FAILED;
 918                 }
 919                 if (verify_expected && !oideq(&revs.oid[i], &expected)) {
 920                         unlink_or_warn(git_path_bisect_ancestors_ok());
 921                         unlink_or_warn(git_path_bisect_expected_rev());
 922                         verify_expected = 0;
 923                 }
 924         }
 925
 926         oid_array_clear(&revs);
 927         return bisect_auto_next(terms, NULL);
 928 }
 929
 930 static enum bisect_error bisect_log(void)
 931 {
 932         int fd, status;
 933         const char* filename = git_path_bisect_log();
 934
 935         if (is_empty_or_missing_file(filename))
 936                 return error(_("We are not bisecting."));
 937
 938         fd = open(filename, O_RDONLY);
 939         if (fd < 0)
 940                 return BISECT_FAILED;
 941
 942         status = copy_fd(fd, STDOUT_FILENO);
 943         close(fd);
 944         return status ? BISECT_FAILED : BISECT_OK;
 945 }
 946
 947 static int process_replay_line(struct bisect_terms *terms, struct strbuf *line)
 948 {
 949         const char *p = line->buf + strspn(line->buf, " \t");
 950         char *word_end, *rev;
 951
 952         if ((!skip_prefix(p, "git bisect", &p) &&
 953         !skip_prefix(p, "git-bisect", &p)) || !isspace(*p))
 954                 return 0;
 955         p += strspn(p, " \t");
 956
 957         word_end = (char *)p + strcspn(p, " \t");
 958         rev = word_end + strspn(word_end, " \t");
 959         *word_end = '\0'; /* NUL-terminate the word */
 960
 961         get_terms(terms);
 962         if (check_and_set_terms(terms, p))
 963                 return -1;
 964
 965         if (!strcmp(p, "start")) {
 966                 struct strvec argv = STRVEC_INIT;
 967                 int res;
 968                 sq_dequote_to_strvec(rev, &argv);
 969                 res = bisect_start(terms, argv.v, argv.nr);
 970                 strvec_clear(&argv);
 971                 return res;
 972         }
 973
 974         if (one_of(p, terms->term_good,
 975            terms->term_bad, "skip", NULL))
 976                 return bisect_write(p, rev, terms, 0);
 977
 978         if (!strcmp(p, "terms")) {
 979                 struct strvec argv = STRVEC_INIT;
 980                 int res;
 981                 sq_dequote_to_strvec(rev, &argv);
 982                 res = bisect_terms(terms, argv.nr == 1 ? argv.v[0] : NULL);
 983                 strvec_clear(&argv);
 984                 return res;
 985         }
 986         error(_("'%s'?? what are you talking about?"), p);
 987
 988         return -1;
 989 }
 990
 991 static enum bisect_error bisect_replay(struct bisect_terms *terms, const char *filename)
 992 {
 993         FILE *fp = NULL;
 994         enum bisect_error res = BISECT_OK;
 995         struct strbuf line = STRBUF_INIT;
 996
 997         if (is_empty_or_missing_file(filename))
 998                 return error(_("cannot read file '%s' for replaying"), filename);
 999
1000         if (bisect_reset(NULL))
1001                 return BISECT_FAILED;
1002
1003         fp = fopen(filename, "r");
1004         if (!fp)
1005                 return BISECT_FAILED;
1006
1007         while ((strbuf_getline(&line, fp) != EOF) && !res)
1008                 res = process_replay_line(terms, &line);
1009
1010         strbuf_release(&line);
1011         fclose(fp);
1012
1013         if (res)
1014                 return BISECT_FAILED;
1015
1016         return bisect_auto_next(terms, NULL);
1017 }
1018
1019 static enum bisect_error bisect_skip(struct bisect_terms *terms, const char **argv, int argc)
1020 {
1021         int i;
1022         enum bisect_error res;
1023         struct strvec argv_state = STRVEC_INIT;
1024
1025         strvec_push(&argv_state, "skip");
1026
1027         for (i = 0; i < argc; i++) {
1028                 const char *dotdot = strstr(argv[i], "..");
1029
1030                 if (dotdot) {
1031                         struct rev_info revs;
1032                         struct commit *commit;
1033
1034                         init_revisions(&revs, NULL);
1035                         setup_revisions(2, argv + i - 1, &revs, NULL);
1036
1037                         if (prepare_revision_walk(&revs))
1038                                 die(_("revision walk setup failed\n"));
1039                         while ((commit = get_revision(&revs)) != NULL)
1040                                 strvec_push(&argv_state,
1041                                                 oid_to_hex(&commit->object.oid));
1042
1043                         reset_revision_walk();
1044                 } else {
1045                         strvec_push(&argv_state, argv[i]);
1046                 }
1047         }
1048         res = bisect_state(terms, argv_state.v, argv_state.nr);
1049
1050         strvec_clear(&argv_state);
1051         return res;
1052 }
1053
1054 static int bisect_visualize(struct bisect_terms *terms, const char **argv, int argc)
1055 {
1056         struct strvec args = STRVEC_INIT;
1057         int flags = RUN_COMMAND_NO_STDIN, res = 0;
1058         struct strbuf sb = STRBUF_INIT;
1059
1060         if (bisect_next_check(terms, NULL) != 0)
1061                 return BISECT_FAILED;
1062
1063         if (!argc) {
1064                 if ((getenv("DISPLAY") || getenv("SESSIONNAME") || getenv("MSYSTEM") ||
1065                      getenv("SECURITYSESSIONID")) && exists_in_PATH("gitk")) {
1066                         strvec_push(&args, "gitk");
1067                 } else {
1068                         strvec_push(&args, "log");
1069                         flags |= RUN_GIT_CMD;
1070                 }
1071         } else {
1072                 if (argv[0][0] == '-') {
1073                         strvec_push(&args, "log");
1074                         flags |= RUN_GIT_CMD;
1075                 } else if (strcmp(argv[0], "tig") && !starts_with(argv[0], "git"))
1076                         flags |= RUN_GIT_CMD;
1077
1078                 strvec_pushv(&args, argv);
1079         }
1080
1081         strvec_pushl(&args, "--bisect", "--", NULL);
1082
1083         strbuf_read_file(&sb, git_path_bisect_names(), 0);
1084         sq_dequote_to_strvec(sb.buf, &args);
1085         strbuf_release(&sb);
1086
1087         res = run_command_v_opt(args.v, flags);
1088         strvec_clear(&args);
1089         return res;
1090 }
1091
1092 static int bisect_run(struct bisect_terms *terms, const char **argv, int argc)
1093 {
1094         int res = BISECT_OK;
1095         struct strbuf command = STRBUF_INIT;
1096         struct strvec args = STRVEC_INIT;
1097         struct strvec run_args = STRVEC_INIT;
1098         const char *new_state;
1099         int temporary_stdout_fd, saved_stdout;
1100
1101         if (bisect_next_check(terms, NULL))
1102                 return BISECT_FAILED;
1103
1104         if (argc)
1105                 sq_quote_argv(&command, argv);
1106         else {
1107                 error(_("bisect run failed: no command provided."));
1108                 return BISECT_FAILED;
1109         }
1110
1111         strvec_push(&run_args, command.buf);
1112
1113         while (1) {
1114                 strvec_clear(&args);
1115
1116                 printf(_("running %s\n"), command.buf);
1117                 res = run_command_v_opt(run_args.v, RUN_USING_SHELL);
1118
1119                 if (res < 0 || 128 <= res) {
1120                         error(_("bisect run failed: exit code %d from"
1121                                 " '%s' is < 0 or >= 128"), res, command.buf);
1122                         strbuf_release(&command);
1123                         return res;
1124                 }
1125
1126                 if (res == 125)
1127                         new_state = "skip";
1128                 else if (!res)
1129                         new_state = terms->term_good;
1130                 else
1131                         new_state = terms->term_bad;
1132
1133                 temporary_stdout_fd = open(git_path_bisect_run(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
1134
1135                 if (temporary_stdout_fd < 0)
1136                         return error_errno(_("cannot open file '%s' for writing"), git_path_bisect_run());
1137
1138                 fflush(stdout);
1139                 saved_stdout = dup(1);
1140                 dup2(temporary_stdout_fd, 1);
1141
1142                 res = bisect_state(terms, &new_state, 1);
1143
1144                 fflush(stdout);
1145                 dup2(saved_stdout, 1);
1146                 close(saved_stdout);
1147                 close(temporary_stdout_fd);
1148
1149                 print_file_to_stdout(git_path_bisect_run());
1150
1151                 if (res == BISECT_ONLY_SKIPPED_LEFT)
1152                         error(_("bisect run cannot continue any more"));
1153                 else if (res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) {
1154                         printf(_("bisect run success"));
1155                         res = BISECT_OK;
1156                 } else if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
1157                         printf(_("bisect found first bad commit"));
1158                         res = BISECT_OK;
1159                 } else if (res) {
1160                         error(_("bisect run failed: 'git bisect--helper --bisect-state"
1161                         " %s' exited with error code %d"), args.v[0], res);
1162                 } else {
1163                         continue;
1164                 }
1165
1166                 strbuf_release(&command);
1167                 strvec_clear(&args);
1168                 strvec_clear(&run_args);
1169                 return res;
1170         }
1171 }
1172
1173 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
1174 {
1175         enum {
1176                 BISECT_RESET = 1,
1177                 BISECT_NEXT_CHECK,
1178                 BISECT_TERMS,
1179                 BISECT_START,
1180                 BISECT_AUTOSTART,
1181                 BISECT_NEXT,
1182                 BISECT_STATE,
1183                 BISECT_LOG,
1184                 BISECT_REPLAY,
1185                 BISECT_SKIP,
1186                 BISECT_VISUALIZE,
1187                 BISECT_RUN,
1188         } cmdmode = 0;
1189         int res = 0, nolog = 0;
1190         struct option options[] = {
1191                 OPT_CMDMODE(0, "bisect-reset", &cmdmode,
1192                          N_("reset the bisection state"), BISECT_RESET),
1193                 OPT_CMDMODE(0, "bisect-next-check", &cmdmode,
1194                          N_("check whether bad or good terms exist"), BISECT_NEXT_CHECK),
1195                 OPT_CMDMODE(0, "bisect-terms", &cmdmode,
1196                          N_("print out the bisect terms"), BISECT_TERMS),
1197                 OPT_CMDMODE(0, "bisect-start", &cmdmode,
1198                          N_("start the bisect session"), BISECT_START),
1199                 OPT_CMDMODE(0, "bisect-next", &cmdmode,
1200                          N_("find the next bisection commit"), BISECT_NEXT),
1201                 OPT_CMDMODE(0, "bisect-state", &cmdmode,
1202                          N_("mark the state of ref (or refs)"), BISECT_STATE),
1203                 OPT_CMDMODE(0, "bisect-log", &cmdmode,
1204                          N_("list the bisection steps so far"), BISECT_LOG),
1205                 OPT_CMDMODE(0, "bisect-replay", &cmdmode,
1206                          N_("replay the bisection process from the given file"), BISECT_REPLAY),
1207                 OPT_CMDMODE(0, "bisect-skip", &cmdmode,
1208                          N_("skip some commits for checkout"), BISECT_SKIP),
1209                 OPT_CMDMODE(0, "bisect-visualize", &cmdmode,
1210                          N_("visualize the bisection"), BISECT_VISUALIZE),
1211                 OPT_CMDMODE(0, "bisect-run", &cmdmode,
1212                          N_("use <cmd>... to automatically bisect."), BISECT_RUN),
1213                 OPT_BOOL(0, "no-log", &nolog,
1214                          N_("no log for BISECT_WRITE")),
1215                 OPT_END()
1216         };
1217         struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
1218
1219         argc = parse_options(argc, argv, prefix, options,
1220                              git_bisect_helper_usage,
1221                              PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN);
1222
1223         if (!cmdmode)
1224                 usage_with_options(git_bisect_helper_usage, options);
1225
1226         switch (cmdmode) {
1227         case BISECT_RESET:
1228                 if (argc > 1)
1229                         return error(_("--bisect-reset requires either no argument or a commit"));
1230                 res = bisect_reset(argc ? argv[0] : NULL);
1231                 break;
1232         case BISECT_TERMS:
1233                 if (argc > 1)
1234                         return error(_("--bisect-terms requires 0 or 1 argument"));
1235                 res = bisect_terms(&terms, argc == 1 ? argv[0] : NULL);
1236                 break;
1237         case BISECT_START:
1238                 set_terms(&terms, "bad", "good");
1239                 res = bisect_start(&terms, argv, argc);
1240                 break;
1241         case BISECT_NEXT:
1242                 if (argc)
1243                         return error(_("--bisect-next requires 0 arguments"));
1244                 get_terms(&terms);
1245                 res = bisect_next(&terms, prefix);
1246                 break;
1247         case BISECT_STATE:
1248                 set_terms(&terms, "bad", "good");
1249                 get_terms(&terms);
1250                 res = bisect_state(&terms, argv, argc);
1251                 break;
1252         case BISECT_LOG:
1253                 if (argc)
1254                         return error(_("--bisect-log requires 0 arguments"));
1255                 res = bisect_log();
1256                 break;
1257         case BISECT_REPLAY:
1258                 if (argc != 1)
1259                         return error(_("no logfile given"));
1260                 set_terms(&terms, "bad", "good");
1261                 res = bisect_replay(&terms, argv[0]);
1262                 break;
1263         case BISECT_SKIP:
1264                 set_terms(&terms, "bad", "good");
1265                 get_terms(&terms);
1266                 res = bisect_skip(&terms, argv, argc);
1267                 break;
1268         case BISECT_VISUALIZE:
1269                 get_terms(&terms);
1270                 res = bisect_visualize(&terms, argv, argc);
1271                 break;
1272         case BISECT_RUN:
1273                 if (!argc)
1274                         return error(_("bisect run failed: no command provided."));
1275                 get_terms(&terms);
1276                 res = bisect_run(&terms, argv, argc);
1277                 break;
1278         default:
1279                 BUG("unknown subcommand %d", cmdmode);
1280         }
1281         free_terms(&terms);
1282
1283         /*
1284          * Handle early success
1285          * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
1286          */
1287         if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
1288                 res = BISECT_OK;
1289
1290         return -res;
1291 }