parse-options.c

   1 #include "git-compat-util.h"
   2 #include "parse-options.h"
   3 #include "cache.h"
   4 #include "commit.h"
   5 #include "color.h"
   6 #include "string-list.h"
   7
   8 static int parse_options_usage(struct parse_opt_ctx_t *ctx,
   9                                const char * const *usagestr,
  10                                const struct option *opts, int err);
  11
  12 #define OPT_SHORT 1
  13 #define OPT_UNSET 2
  14
  15 static int optbug(const struct option *opt, const char *reason)
  16 {
  17         if (opt->long_name)
  18                 return error("BUG: option '%s' %s", opt->long_name, reason);
  19         return error("BUG: switch '%c' %s", opt->short_name, reason);
  20 }
  21
  22 static int opterror(const struct option *opt, const char *reason, int flags)
  23 {
  24         if (flags & OPT_SHORT)
  25                 return error("switch `%c' %s", opt->short_name, reason);
  26         if (flags & OPT_UNSET)
  27                 return error("option `no-%s' %s", opt->long_name, reason);
  28         return error("option `%s' %s", opt->long_name, reason);
  29 }
  30
  31 static int get_arg(struct parse_opt_ctx_t *p, const struct option *opt,
  32                    int flags, const char **arg)
  33 {
  34         if (p->opt) {
  35                 *arg = p->opt;
  36                 p->opt = NULL;
  37         } else if (p->argc == 1 && (opt->flags & PARSE_OPT_LASTARG_DEFAULT)) {
  38                 *arg = (const char *)opt->defval;
  39         } else if (p->argc > 1) {
  40                 p->argc--;
  41                 *arg = *++p->argv;
  42         } else
  43                 return opterror(opt, "requires a value", flags);
  44         return 0;
  45 }
  46
  47 static void fix_filename(const char *prefix, const char **file)
  48 {
  49         if (!file || !*file || !prefix || is_absolute_path(*file)
  50             || !strcmp("-", *file))
  51                 return;
  52         *file = xstrdup(prefix_filename(prefix, strlen(prefix), *file));
  53 }
  54
  55 static int get_value(struct parse_opt_ctx_t *p,
  56                      const struct option *opt, int flags)
  57 {
  58         const char *s, *arg;
  59         const int unset = flags & OPT_UNSET;
  60         int err;
  61
  62         if (unset && p->opt)
  63                 return opterror(opt, "takes no value", flags);
  64         if (unset && (opt->flags & PARSE_OPT_NONEG))
  65                 return opterror(opt, "isn't available", flags);
  66         if (!(flags & OPT_SHORT) && p->opt && (opt->flags & PARSE_OPT_NOARG))
  67                 return opterror(opt, "takes no value", flags);
  68
  69         switch (opt->type) {
  70         case OPTION_LOWLEVEL_CALLBACK:
  71                 return (*(parse_opt_ll_cb *)opt->callback)(p, opt, unset);
  72
  73         case OPTION_BIT:
  74                 if (unset)
  75                         *(int *)opt->value &= ~opt->defval;
  76                 else
  77                         *(int *)opt->value |= opt->defval;
  78                 return 0;
  79
  80         case OPTION_NEGBIT:
  81                 if (unset)
  82                         *(int *)opt->value |= opt->defval;
  83                 else
  84                         *(int *)opt->value &= ~opt->defval;
  85                 return 0;
  86
  87         case OPTION_BOOLEAN:
  88                 *(int *)opt->value = unset ? 0 : *(int *)opt->value + 1;
  89                 return 0;
  90
  91         case OPTION_SET_INT:
  92                 *(int *)opt->value = unset ? 0 : opt->defval;
  93                 return 0;
  94
  95         case OPTION_SET_PTR:
  96                 *(void **)opt->value = unset ? NULL : (void *)opt->defval;
  97                 return 0;
  98
  99         case OPTION_STRING:
 100                 if (unset)
 101                         *(const char **)opt->value = NULL;
 102                 else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
 103                         *(const char **)opt->value = (const char *)opt->defval;
 104                 else
 105                         return get_arg(p, opt, flags, (const char **)opt->value);
 106                 return 0;
 107
 108         case OPTION_FILENAME:
 109                 err = 0;
 110                 if (unset)
 111                         *(const char **)opt->value = NULL;
 112                 else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
 113                         *(const char **)opt->value = (const char *)opt->defval;
 114                 else
 115                         err = get_arg(p, opt, flags, (const char **)opt->value);
 116
 117                 if (!err)
 118                         fix_filename(p->prefix, (const char **)opt->value);
 119                 return err;
 120
 121         case OPTION_CALLBACK:
 122                 if (unset)
 123                         return (*opt->callback)(opt, NULL, 1) ? (-1) : 0;
 124                 if (opt->flags & PARSE_OPT_NOARG)
 125                         return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
 126                 if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
 127                         return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
 128                 if (get_arg(p, opt, flags, &arg))
 129                         return -1;
 130                 return (*opt->callback)(opt, arg, 0) ? (-1) : 0;
 131
 132         case OPTION_INTEGER:
 133                 if (unset) {
 134                         *(int *)opt->value = 0;
 135                         return 0;
 136                 }
 137                 if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
 138                         *(int *)opt->value = opt->defval;
 139                         return 0;
 140                 }
 141                 if (get_arg(p, opt, flags, &arg))
 142                         return -1;
 143                 *(int *)opt->value = strtol(arg, (char **)&s, 10);
 144                 if (*s)
 145                         return opterror(opt, "expects a numerical value", flags);
 146                 return 0;
 147
 148         default:
 149                 die("should not happen, someone must be hit on the forehead");
 150         }
 151 }
 152
 153 static int parse_short_opt(struct parse_opt_ctx_t *p, const struct option *options)
 154 {
 155         const struct option *numopt = NULL;
 156
 157         for (; options->type != OPTION_END; options++) {
 158                 if (options->short_name == *p->opt) {
 159                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
 160                         return get_value(p, options, OPT_SHORT);
 161                 }
 162
 163                 /*
 164                  * Handle the numerical option later, explicit one-digit
 165                  * options take precedence over it.
 166                  */
 167                 if (options->type == OPTION_NUMBER)
 168                         numopt = options;
 169         }
 170         if (numopt && isdigit(*p->opt)) {
 171                 size_t len = 1;
 172                 char *arg;
 173                 int rc;
 174
 175                 while (isdigit(p->opt[len]))
 176                         len++;
 177                 arg = xmemdupz(p->opt, len);
 178                 p->opt = p->opt[len] ? p->opt + len : NULL;
 179                 rc = (*numopt->callback)(numopt, arg, 0) ? (-1) : 0;
 180                 free(arg);
 181                 return rc;
 182         }
 183         return -2;
 184 }
 185
 186 static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg,
 187                           const struct option *options)
 188 {
 189         const char *arg_end = strchr(arg, '=');
 190         const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
 191         int abbrev_flags = 0, ambiguous_flags = 0;
 192
 193         if (!arg_end)
 194                 arg_end = arg + strlen(arg);
 195
 196         for (; options->type != OPTION_END; options++) {
 197                 const char *rest;
 198                 int flags = 0;
 199
 200                 if (!options->long_name)
 201                         continue;
 202
 203                 rest = skip_prefix(arg, options->long_name);
 204                 if (options->type == OPTION_ARGUMENT) {
 205                         if (!rest)
 206                                 continue;
 207                         if (*rest == '=')
 208                                 return opterror(options, "takes no value", flags);
 209                         if (*rest)
 210                                 continue;
 211                         p->out[p->cpidx++] = arg - 2;
 212                         return 0;
 213                 }
 214                 if (!rest) {
 215                         /* abbreviated? */
 216                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
 217 is_abbreviated:
 218                                 if (abbrev_option) {
 219                                         /*
 220                                          * If this is abbreviated, it is
 221                                          * ambiguous. So when there is no
 222                                          * exact match later, we need to
 223                                          * error out.
 224                                          */
 225                                         ambiguous_option = abbrev_option;
 226                                         ambiguous_flags = abbrev_flags;
 227                                 }
 228                                 if (!(flags & OPT_UNSET) && *arg_end)
 229                                         p->opt = arg_end + 1;
 230                                 abbrev_option = options;
 231                                 abbrev_flags = flags;
 232                                 continue;
 233                         }
 234                         /* negation allowed? */
 235                         if (options->flags & PARSE_OPT_NONEG)
 236                                 continue;
 237                         /* negated and abbreviated very much? */
 238                         if (!prefixcmp("no-", arg)) {
 239                                 flags |= OPT_UNSET;
 240                                 goto is_abbreviated;
 241                         }
 242                         /* negated? */
 243                         if (strncmp(arg, "no-", 3))
 244                                 continue;
 245                         flags |= OPT_UNSET;
 246                         rest = skip_prefix(arg + 3, options->long_name);
 247                         /* abbreviated and negated? */
 248                         if (!rest && !prefixcmp(options->long_name, arg + 3))
 249                                 goto is_abbreviated;
 250                         if (!rest)
 251                                 continue;
 252                 }
 253                 if (*rest) {
 254                         if (*rest != '=')
 255                                 continue;
 256                         p->opt = rest + 1;
 257                 }
 258                 return get_value(p, options, flags);
 259         }
 260
 261         if (ambiguous_option)
 262                 return error("Ambiguous option: %s "
 263                         "(could be --%s%s or --%s%s)",
 264                         arg,
 265                         (ambiguous_flags & OPT_UNSET) ?  "no-" : "",
 266                         ambiguous_option->long_name,
 267                         (abbrev_flags & OPT_UNSET) ?  "no-" : "",
 268                         abbrev_option->long_name);
 269         if (abbrev_option)
 270                 return get_value(p, abbrev_option, abbrev_flags);
 271         return -2;
 272 }
 273
 274 static int parse_nodash_opt(struct parse_opt_ctx_t *p, const char *arg,
 275                             const struct option *options)
 276 {
 277         for (; options->type != OPTION_END; options++) {
 278                 if (!(options->flags & PARSE_OPT_NODASH))
 279                         continue;
 280                 if (options->short_name == arg[0] && arg[1] == '\0')
 281                         return get_value(p, options, OPT_SHORT);
 282         }
 283         return -2;
 284 }
 285
 286 static void check_typos(const char *arg, const struct option *options)
 287 {
 288         if (strlen(arg) < 3)
 289                 return;
 290
 291         if (!prefixcmp(arg, "no-")) {
 292                 error ("did you mean `--%s` (with two dashes ?)", arg);
 293                 exit(129);
 294         }
 295
 296         for (; options->type != OPTION_END; options++) {
 297                 if (!options->long_name)
 298                         continue;
 299                 if (!prefixcmp(options->long_name, arg)) {
 300                         error ("did you mean `--%s` (with two dashes ?)", arg);
 301                         exit(129);
 302                 }
 303         }
 304 }
 305
 306 static void parse_options_check(const struct option *opts)
 307 {
 308         int err = 0;
 309
 310         for (; opts->type != OPTION_END; opts++) {
 311                 if ((opts->flags & PARSE_OPT_LASTARG_DEFAULT) &&
 312                     (opts->flags & PARSE_OPT_OPTARG))
 313                         err |= optbug(opts, "uses incompatible flags "
 314                                         "LASTARG_DEFAULT and OPTARG");
 315                 if (opts->flags & PARSE_OPT_NODASH &&
 316                     ((opts->flags & PARSE_OPT_OPTARG) ||
 317                      !(opts->flags & PARSE_OPT_NOARG) ||
 318                      !(opts->flags & PARSE_OPT_NONEG) ||
 319                      opts->long_name))
 320                         err |= optbug(opts, "uses feature "
 321                                         "not supported for dashless options");
 322                 switch (opts->type) {
 323                 case OPTION_BOOLEAN:
 324                 case OPTION_BIT:
 325                 case OPTION_NEGBIT:
 326                 case OPTION_SET_INT:
 327                 case OPTION_SET_PTR:
 328                 case OPTION_NUMBER:
 329                         if ((opts->flags & PARSE_OPT_OPTARG) ||
 330                             !(opts->flags & PARSE_OPT_NOARG))
 331                                 err |= optbug(opts, "should not accept an argument");
 332                 default:
 333                         ; /* ok. (usually accepts an argument) */
 334                 }
 335         }
 336         if (err)
 337                 exit(128);
 338 }
 339
 340 void parse_options_start(struct parse_opt_ctx_t *ctx,
 341                          int argc, const char **argv, const char *prefix,
 342                          const struct option *options, int flags)
 343 {
 344         memset(ctx, 0, sizeof(*ctx));
 345         ctx->argc = argc - 1;
 346         ctx->argv = argv + 1;
 347         ctx->out  = argv;
 348         ctx->prefix = prefix;
 349         ctx->cpidx = ((flags & PARSE_OPT_KEEP_ARGV0) != 0);
 350         ctx->flags = flags;
 351         if ((flags & PARSE_OPT_KEEP_UNKNOWN) &&
 352             (flags & PARSE_OPT_STOP_AT_NON_OPTION))
 353                 die("STOP_AT_NON_OPTION and KEEP_UNKNOWN don't go together");
 354         parse_options_check(options);
 355 }
 356
 357 static int usage_with_options_internal(struct parse_opt_ctx_t *,
 358                                        const char * const *,
 359                                        const struct option *, int, int);
 360
 361 int parse_options_step(struct parse_opt_ctx_t *ctx,
 362                        const struct option *options,
 363                        const char * const usagestr[])
 364 {
 365         int internal_help = !(ctx->flags & PARSE_OPT_NO_INTERNAL_HELP);
 366
 367         /* we must reset ->opt, unknown short option leave it dangling */
 368         ctx->opt = NULL;
 369
 370         for (; ctx->argc; ctx->argc--, ctx->argv++) {
 371                 const char *arg = ctx->argv[0];
 372
 373                 if (*arg != '-' || !arg[1]) {
 374                         if (parse_nodash_opt(ctx, arg, options) == 0)
 375                                 continue;
 376                         if (ctx->flags & PARSE_OPT_STOP_AT_NON_OPTION)
 377                                 return PARSE_OPT_NON_OPTION;
 378                         ctx->out[ctx->cpidx++] = ctx->argv[0];
 379                         continue;
 380                 }
 381
 382                 if (arg[1] != '-') {
 383                         ctx->opt = arg + 1;
 384                         if (internal_help && *ctx->opt == 'h')
 385                                 return parse_options_usage(ctx, usagestr, options, 0);
 386                         switch (parse_short_opt(ctx, options)) {
 387                         case -1:
 388                                 return parse_options_usage(ctx, usagestr, options, 1);
 389                         case -2:
 390                                 goto unknown;
 391                         }
 392                         if (ctx->opt)
 393                                 check_typos(arg + 1, options);
 394                         while (ctx->opt) {
 395                                 if (internal_help && *ctx->opt == 'h')
 396                                         return parse_options_usage(ctx, usagestr, options, 0);
 397                                 switch (parse_short_opt(ctx, options)) {
 398                                 case -1:
 399                                         return parse_options_usage(ctx, usagestr, options, 1);
 400                                 case -2:
 401                                         /* fake a short option thing to hide the fact that we may have
 402                                          * started to parse aggregated stuff
 403                                          *
 404                                          * This is leaky, too bad.
 405                                          */
 406                                         ctx->argv[0] = xstrdup(ctx->opt - 1);
 407                                         *(char *)ctx->argv[0] = '-';
 408                                         goto unknown;
 409                                 }
 410                         }
 411                         continue;
 412                 }
 413
 414                 if (!arg[2]) { /* "--" */
 415                         if (!(ctx->flags & PARSE_OPT_KEEP_DASHDASH)) {
 416                                 ctx->argc--;
 417                                 ctx->argv++;
 418                         }
 419                         break;
 420                 }
 421
 422                 if (internal_help && !strcmp(arg + 2, "help-all"))
 423                         return usage_with_options_internal(ctx, usagestr, options, 1, 0);
 424                 if (internal_help && !strcmp(arg + 2, "help"))
 425                         return parse_options_usage(ctx, usagestr, options, 0);
 426                 switch (parse_long_opt(ctx, arg + 2, options)) {
 427                 case -1:
 428                         return parse_options_usage(ctx, usagestr, options, 1);
 429                 case -2:
 430                         goto unknown;
 431                 }
 432                 continue;
 433 unknown:
 434                 if (!(ctx->flags & PARSE_OPT_KEEP_UNKNOWN))
 435                         return PARSE_OPT_UNKNOWN;
 436                 ctx->out[ctx->cpidx++] = ctx->argv[0];
 437                 ctx->opt = NULL;
 438         }
 439         return PARSE_OPT_DONE;
 440 }
 441
 442 int parse_options_end(struct parse_opt_ctx_t *ctx)
 443 {
 444         memmove(ctx->out + ctx->cpidx, ctx->argv, ctx->argc * sizeof(*ctx->out));
 445         ctx->out[ctx->cpidx + ctx->argc] = NULL;
 446         return ctx->cpidx + ctx->argc;
 447 }
 448
 449 int parse_options(int argc, const char **argv, const char *prefix,
 450                   const struct option *options, const char * const usagestr[],
 451                   int flags)
 452 {
 453         struct parse_opt_ctx_t ctx;
 454
 455         parse_options_start(&ctx, argc, argv, prefix, options, flags);
 456         switch (parse_options_step(&ctx, options, usagestr)) {
 457         case PARSE_OPT_HELP:
 458                 exit(129);
 459         case PARSE_OPT_NON_OPTION:
 460         case PARSE_OPT_DONE:
 461                 break;
 462         default: /* PARSE_OPT_UNKNOWN */
 463                 if (ctx.argv[0][1] == '-') {
 464                         error("unknown option `%s'", ctx.argv[0] + 2);
 465                 } else {
 466                         error("unknown switch `%c'", *ctx.opt);
 467                 }
 468                 usage_with_options(usagestr, options);
 469         }
 470
 471         return parse_options_end(&ctx);
 472 }
 473
 474 static int usage_argh(const struct option *opts, FILE *outfile)
 475 {
 476         const char *s;
 477         int literal = (opts->flags & PARSE_OPT_LITERAL_ARGHELP) || !opts->argh;
 478         if (opts->flags & PARSE_OPT_OPTARG)
 479                 if (opts->long_name)
 480                         s = literal ? "[=%s]" : "[=<%s>]";
 481                 else
 482                         s = literal ? "[%s]" : "[<%s>]";
 483         else
 484                 s = literal ? " %s" : " <%s>";
 485         return fprintf(outfile, s, opts->argh ? opts->argh : "...");
 486 }
 487
 488 #define USAGE_OPTS_WIDTH 24
 489 #define USAGE_GAP         2
 490
 491 static int usage_with_options_internal(struct parse_opt_ctx_t *ctx,
 492                                        const char * const *usagestr,
 493                                        const struct option *opts, int full, int err)
 494 {
 495         FILE *outfile = err ? stderr : stdout;
 496
 497         if (!usagestr)
 498                 return PARSE_OPT_HELP;
 499
 500         if (!err && ctx && ctx->flags & PARSE_OPT_SHELL_EVAL)
 501                 fprintf(outfile, "cat <<\\EOF\n");
 502
 503         fprintf(outfile, "usage: %s\n", *usagestr++);
 504         while (*usagestr && **usagestr)
 505                 fprintf(outfile, "   or: %s\n", *usagestr++);
 506         while (*usagestr) {
 507                 fprintf(outfile, "%s%s\n",
 508                                 **usagestr ? "    " : "",
 509                                 *usagestr);
 510                 usagestr++;
 511         }
 512
 513         if (opts->type != OPTION_GROUP)
 514                 fputc('\n', outfile);
 515
 516         for (; opts->type != OPTION_END; opts++) {
 517                 size_t pos;
 518                 int pad;
 519
 520                 if (opts->type == OPTION_GROUP) {
 521                         fputc('\n', outfile);
 522                         if (*opts->help)
 523                                 fprintf(outfile, "%s\n", opts->help);
 524                         continue;
 525                 }
 526                 if (!full && (opts->flags & PARSE_OPT_HIDDEN))
 527                         continue;
 528
 529                 pos = fprintf(outfile, "    ");
 530                 if (opts->short_name && !(opts->flags & PARSE_OPT_NEGHELP)) {
 531                         if (opts->flags & PARSE_OPT_NODASH)
 532                                 pos += fprintf(outfile, "%c", opts->short_name);
 533                         else
 534                                 pos += fprintf(outfile, "-%c", opts->short_name);
 535                 }
 536                 if (opts->long_name && opts->short_name)
 537                         pos += fprintf(outfile, ", ");
 538                 if (opts->long_name)
 539                         pos += fprintf(outfile, "--%s%s",
 540                                 (opts->flags & PARSE_OPT_NEGHELP) ?  "no-" : "",
 541                                 opts->long_name);
 542                 if (opts->type == OPTION_NUMBER)
 543                         pos += fprintf(outfile, "-NUM");
 544
 545                 if ((opts->flags & PARSE_OPT_LITERAL_ARGHELP) ||
 546                     !(opts->flags & PARSE_OPT_NOARG))
 547                         pos += usage_argh(opts, outfile);
 548
 549                 if (pos <= USAGE_OPTS_WIDTH)
 550                         pad = USAGE_OPTS_WIDTH - pos;
 551                 else {
 552                         fputc('\n', outfile);
 553                         pad = USAGE_OPTS_WIDTH;
 554                 }
 555                 fprintf(outfile, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 556         }
 557         fputc('\n', outfile);
 558
 559         if (!err && ctx && ctx->flags & PARSE_OPT_SHELL_EVAL)
 560                 fputs("EOF\n", outfile);
 561
 562         return PARSE_OPT_HELP;
 563 }
 564
 565 void NORETURN usage_with_options(const char * const *usagestr,
 566                         const struct option *opts)
 567 {
 568         usage_with_options_internal(NULL, usagestr, opts, 0, 1);
 569         exit(129);
 570 }
 571
 572 void NORETURN usage_msg_opt(const char *msg,
 573                    const char * const *usagestr,
 574                    const struct option *options)
 575 {
 576         fprintf(stderr, "%s\n\n", msg);
 577         usage_with_options(usagestr, options);
 578 }
 579
 580 static int parse_options_usage(struct parse_opt_ctx_t *ctx,
 581                                const char * const *usagestr,
 582                                const struct option *opts, int err)
 583 {
 584         return usage_with_options_internal(ctx, usagestr, opts, 0, err);
 585 }
 586
 587
 588 /*----- some often used options -----*/
 589 #include "cache.h"
 590
 591 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
 592 {
 593         int v;
 594
 595         if (!arg) {
 596                 v = unset ? 0 : DEFAULT_ABBREV;
 597         } else {
 598                 v = strtol(arg, (char **)&arg, 10);
 599                 if (*arg)
 600                         return opterror(opt, "expects a numerical value", 0);
 601                 if (v && v < MINIMUM_ABBREV)
 602                         v = MINIMUM_ABBREV;
 603                 else if (v > 40)
 604                         v = 40;
 605         }
 606         *(int *)(opt->value) = v;
 607         return 0;
 608 }
 609
 610 int parse_opt_approxidate_cb(const struct option *opt, const char *arg,
 611                              int unset)
 612 {
 613         *(unsigned long *)(opt->value) = approxidate(arg);
 614         return 0;
 615 }
 616
 617 int parse_opt_color_flag_cb(const struct option *opt, const char *arg,
 618                             int unset)
 619 {
 620         int value;
 621
 622         if (!arg)
 623                 arg = unset ? "never" : (const char *)opt->defval;
 624         value = git_config_colorbool(NULL, arg, -1);
 625         if (value < 0)
 626                 return opterror(opt,
 627                         "expects \"always\", \"auto\", or \"never\"", 0);
 628         *(int *)opt->value = value;
 629         return 0;
 630 }
 631
 632 int parse_opt_verbosity_cb(const struct option *opt, const char *arg,
 633                            int unset)
 634 {
 635         int *target = opt->value;
 636
 637         if (unset)
 638                 /* --no-quiet, --no-verbose */
 639                 *target = 0;
 640         else if (opt->short_name == 'v') {
 641                 if (*target >= 0)
 642                         (*target)++;
 643                 else
 644                         *target = 1;
 645         } else {
 646                 if (*target <= 0)
 647                         (*target)--;
 648                 else
 649                         *target = -1;
 650         }
 651         return 0;
 652 }
 653
 654 int parse_opt_with_commit(const struct option *opt, const char *arg, int unset)
 655 {
 656         unsigned char sha1[20];
 657         struct commit *commit;
 658
 659         if (!arg)
 660                 return -1;
 661         if (get_sha1(arg, sha1))
 662                 return error("malformed object name %s", arg);
 663         commit = lookup_commit_reference(sha1);
 664         if (!commit)
 665                 return error("no such commit %s", arg);
 666         commit_list_insert(commit, opt->value);
 667         return 0;
 668 }
 669
 670 int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 671 {
 672         int *target = opt->value;
 673         *target = unset ? 2 : 1;
 674         return 0;
 675 }
 676
 677 int parse_options_concat(struct option *dst, size_t dst_size, struct option *src)
 678 {
 679         int i, j;
 680
 681         for (i = 0; i < dst_size; i++)
 682                 if (dst[i].type == OPTION_END)
 683                         break;
 684         for (j = 0; i < dst_size; i++, j++) {
 685                 dst[i] = src[j];
 686                 if (src[j].type == OPTION_END)
 687                         return 0;
 688         }
 689         return -1;
 690 }
 691
 692 int parse_opt_string_list(const struct option *opt, const char *arg, int unset)
 693 {
 694         struct string_list *v = opt->value;
 695
 696         if (unset) {
 697                 string_list_clear(v, 0);
 698                 return 0;
 699         }
 700
 701         if (!arg)
 702                 return -1;
 703
 704         string_list_append(v, xstrdup(arg));
 705         return 0;
 706 }