argpar/argpar.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2019-2021 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright (c) 2020-2021 Simon Marchi <simon.marchi@efficios.com>
   6  */
   7
   8 #include <assert.h>
   9 #include <stdarg.h>
  10 #include <stdbool.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 #include "argpar.h"
  16
  17 #define ARGPAR_REALLOC(_ptr, _type, _nmemb)                             \
  18         ((_type *) realloc(_ptr, (_nmemb) * sizeof(_type)))
  19
  20 #define ARGPAR_CALLOC(_type, _nmemb)                                    \
  21         ((_type *) calloc((_nmemb), sizeof(_type)))
  22
  23 #define ARGPAR_ZALLOC(_type) ARGPAR_CALLOC(_type, 1)
  24
  25 #define ARGPAR_ASSERT(_cond) assert(_cond)
  26
  27 #ifdef __MINGW_PRINTF_FORMAT
  28 # define ARGPAR_PRINTF_FORMAT __MINGW_PRINTF_FORMAT
  29 #else
  30 # define ARGPAR_PRINTF_FORMAT printf
  31 #endif
  32
  33 /*
  34  * An argpar iterator.
  35  *
  36  * Such a structure contains the state of an iterator between
  37  * calls to argpar_iter_parse_next().
  38  */
  39 struct argpar_iter {
  40         /*
  41          * Data provided by the user to argpar_iter_create(); immutable
  42          * afterwards.
  43          */
  44         unsigned int argc;
  45         const char * const *argv;
  46         const struct argpar_opt_descr *descrs;
  47
  48         /*
  49          * Index of the argument to process in the next
  50          * argpar_iter_parse_next() call.
  51          */
  52         unsigned int i;
  53
  54         /* Counter of non-option arguments */
  55         int non_opt_index;
  56
  57         /*
  58          * Current character of the current short option group: if it's
  59          * not `NULL`, the parser is in within a short option group,
  60          * therefore it must resume there in the next
  61          * argpar_iter_parse_next() call.
  62          */
  63         const char *short_opt_ch;
  64 };
  65
  66 /* Base parsing item */
  67 struct argpar_item {
  68         enum argpar_item_type type;
  69 };
  70
  71 /* Option parsing item */
  72 struct argpar_item_opt {
  73         struct argpar_item base;
  74
  75         /* Corresponding descriptor */
  76         const struct argpar_opt_descr *descr;
  77
  78         /* Argument, or `NULL` if none; owned by this */
  79         char *arg;
  80 };
  81
  82 /* Non-option parsing item */
  83 struct argpar_item_non_opt {
  84         struct argpar_item base;
  85
  86         /*
  87          * Complete argument, pointing to one of the entries of the
  88          * original arguments (`argv`).
  89          */
  90         const char *arg;
  91
  92         /*
  93          * Index of this argument amongst all original arguments
  94          * (`argv`).
  95          */
  96         unsigned int orig_index;
  97
  98         /* Index of this argument amongst other non-option arguments */
  99         unsigned int non_opt_index;
 100 };
 101
 102 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 0)))
 103 char *argpar_vasprintf(const char * const fmt, va_list args)
 104 {
 105         int len1, len2;
 106         char *str;
 107         va_list args2;
 108
 109         va_copy(args2, args);
 110         len1 = vsnprintf(NULL, 0, fmt, args);
 111         if (len1 < 0) {
 112                 str = NULL;
 113                 goto end;
 114         }
 115
 116         str = malloc(len1 + 1);
 117         if (!str) {
 118                 goto end;
 119         }
 120
 121         len2 = vsnprintf(str, len1 + 1, fmt, args2);
 122         ARGPAR_ASSERT(len1 == len2);
 123
 124 end:
 125         va_end(args2);
 126         return str;
 127 }
 128
 129
 130 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 2)))
 131 char *argpar_asprintf(const char * const fmt, ...)
 132 {
 133         va_list args;
 134         char *str;
 135
 136         va_start(args, fmt);
 137         str = argpar_vasprintf(fmt, args);
 138         va_end(args);
 139         return str;
 140 }
 141
 142 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 2, 3)))
 143 bool append_string_printf(char ** const str, const char *fmt, ...)
 144 {
 145         char *new_str = NULL;
 146         char *addendum;
 147         bool success;
 148         va_list args;
 149
 150         ARGPAR_ASSERT(str);
 151         va_start(args, fmt);
 152         addendum = argpar_vasprintf(fmt, args);
 153         va_end(args);
 154
 155         if (!addendum) {
 156                 success = false;
 157                 goto end;
 158         }
 159
 160         new_str = argpar_asprintf("%s%s", *str ? *str : "", addendum);
 161         if (!new_str) {
 162                 success = false;
 163                 goto end;
 164         }
 165
 166         free(*str);
 167         *str = new_str;
 168         success = true;
 169
 170 end:
 171         free(addendum);
 172         return success;
 173 }
 174
 175 ARGPAR_HIDDEN
 176 enum argpar_item_type argpar_item_type(const struct argpar_item * const item)
 177 {
 178         ARGPAR_ASSERT(item);
 179         return item->type;
 180 }
 181
 182 ARGPAR_HIDDEN
 183 const struct argpar_opt_descr *argpar_item_opt_descr(
 184                 const struct argpar_item * const item)
 185 {
 186         ARGPAR_ASSERT(item);
 187         ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
 188         return ((const struct argpar_item_opt *) item)->descr;
 189 }
 190
 191 ARGPAR_HIDDEN
 192 const char *argpar_item_opt_arg(const struct argpar_item * const item)
 193 {
 194         ARGPAR_ASSERT(item);
 195         ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
 196         return ((const struct argpar_item_opt *) item)->arg;
 197 }
 198
 199 ARGPAR_HIDDEN
 200 const char *argpar_item_non_opt_arg(const struct argpar_item * const item)
 201 {
 202         ARGPAR_ASSERT(item);
 203         ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
 204         return ((const struct argpar_item_non_opt *) item)->arg;
 205 }
 206
 207 ARGPAR_HIDDEN
 208 unsigned int argpar_item_non_opt_orig_index(
 209                 const struct argpar_item * const item)
 210 {
 211         ARGPAR_ASSERT(item);
 212         ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
 213         return ((const struct argpar_item_non_opt *) item)->orig_index;
 214 }
 215
 216 ARGPAR_HIDDEN
 217 unsigned int argpar_item_non_opt_non_opt_index(
 218                 const struct argpar_item * const item)
 219 {
 220         ARGPAR_ASSERT(item);
 221         ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
 222         return ((const struct argpar_item_non_opt *) item)->non_opt_index;
 223 }
 224
 225 ARGPAR_HIDDEN
 226 void argpar_item_destroy(const struct argpar_item * const item)
 227 {
 228         if (!item) {
 229                 goto end;
 230         }
 231
 232         if (item->type == ARGPAR_ITEM_TYPE_OPT) {
 233                 struct argpar_item_opt * const opt_item =
 234                         (struct argpar_item_opt *) item;
 235
 236                 free(opt_item->arg);
 237         }
 238
 239         free((void *) item);
 240
 241 end:
 242         return;
 243 }
 244
 245 static
 246 bool push_item(struct argpar_item_array * const array,
 247                 const struct argpar_item * const item)
 248 {
 249         bool success;
 250
 251         ARGPAR_ASSERT(array);
 252         ARGPAR_ASSERT(item);
 253
 254         if (array->n_items == array->n_alloc) {
 255                 const unsigned int new_n_alloc = array->n_alloc * 2;
 256                 const struct argpar_item ** const new_items =
 257                         ARGPAR_REALLOC(array->items, const struct argpar_item *,
 258                                 new_n_alloc);
 259                 if (!new_items) {
 260                         success = false;
 261                         goto end;
 262                 }
 263
 264                 array->n_alloc = new_n_alloc;
 265                 array->items = new_items;
 266         }
 267
 268         array->items[array->n_items] = item;
 269         array->n_items++;
 270         success = true;
 271
 272 end:
 273         return success;
 274 }
 275
 276 static
 277 void destroy_item_array(struct argpar_item_array * const array)
 278 {
 279         if (array) {
 280                 unsigned int i;
 281
 282                 for (i = 0; i < array->n_items; i++) {
 283                         argpar_item_destroy(array->items[i]);
 284                 }
 285
 286                 free(array->items);
 287                 free(array);
 288         }
 289 }
 290
 291 static
 292 struct argpar_item_array *create_item_array(void)
 293 {
 294         struct argpar_item_array *ret;
 295         const int initial_size = 10;
 296
 297         ret = ARGPAR_ZALLOC(struct argpar_item_array);
 298         if (!ret) {
 299                 goto end;
 300         }
 301
 302         ret->items = ARGPAR_CALLOC(const struct argpar_item *, initial_size);
 303         if (!ret->items) {
 304                 goto error;
 305         }
 306
 307         ret->n_alloc = initial_size;
 308         goto end;
 309
 310 error:
 311         destroy_item_array(ret);
 312         ret = NULL;
 313
 314 end:
 315         return ret;
 316 }
 317
 318 static
 319 struct argpar_item_opt *create_opt_item(
 320                 const struct argpar_opt_descr * const descr,
 321                 const char * const arg)
 322 {
 323         struct argpar_item_opt *opt_item =
 324                 ARGPAR_ZALLOC(struct argpar_item_opt);
 325
 326         if (!opt_item) {
 327                 goto end;
 328         }
 329
 330         opt_item->base.type = ARGPAR_ITEM_TYPE_OPT;
 331         opt_item->descr = descr;
 332
 333         if (arg) {
 334                 opt_item->arg = strdup(arg);
 335                 if (!opt_item->arg) {
 336                         goto error;
 337                 }
 338         }
 339
 340         goto end;
 341
 342 error:
 343         argpar_item_destroy(&opt_item->base);
 344         opt_item = NULL;
 345
 346 end:
 347         return opt_item;
 348 }
 349
 350 static
 351 struct argpar_item_non_opt *create_non_opt_item(const char * const arg,
 352                 const unsigned int orig_index,
 353                 const unsigned int non_opt_index)
 354 {
 355         struct argpar_item_non_opt * const non_opt_item =
 356                 ARGPAR_ZALLOC(struct argpar_item_non_opt);
 357
 358         if (!non_opt_item) {
 359                 goto end;
 360         }
 361
 362         non_opt_item->base.type = ARGPAR_ITEM_TYPE_NON_OPT;
 363         non_opt_item->arg = arg;
 364         non_opt_item->orig_index = orig_index;
 365         non_opt_item->non_opt_index = non_opt_index;
 366
 367 end:
 368         return non_opt_item;
 369 }
 370
 371 static
 372 const struct argpar_opt_descr *find_descr(
 373                 const struct argpar_opt_descr * const descrs,
 374                 const char short_name, const char * const long_name)
 375 {
 376         const struct argpar_opt_descr *descr;
 377
 378         for (descr = descrs; descr->short_name || descr->long_name; descr++) {
 379                 if (short_name && descr->short_name &&
 380                                 short_name == descr->short_name) {
 381                         goto end;
 382                 }
 383
 384                 if (long_name && descr->long_name &&
 385                                 strcmp(long_name, descr->long_name) == 0) {
 386                         goto end;
 387                 }
 388         }
 389
 390 end:
 391         return !descr->short_name && !descr->long_name ? NULL : descr;
 392 }
 393
 394 enum parse_orig_arg_opt_ret {
 395         PARSE_ORIG_ARG_OPT_RET_OK,
 396         PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT = -2,
 397         PARSE_ORIG_ARG_OPT_RET_ERROR = -1,
 398 };
 399
 400 static
 401 enum parse_orig_arg_opt_ret parse_short_opts(const char * const short_opts,
 402                 const char * const next_orig_arg,
 403                 const struct argpar_opt_descr * const descrs,
 404                 struct argpar_iter * const iter,
 405                 char ** const error, struct argpar_item ** const item)
 406 {
 407         enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 408         bool used_next_orig_arg = false;
 409         const char *opt_arg = NULL;
 410         const struct argpar_opt_descr *descr;
 411         struct argpar_item_opt *opt_item;
 412
 413         if (strlen(short_opts) == 0) {
 414                 append_string_printf(error, "Invalid argument");
 415                 goto error;
 416         }
 417
 418         if (!iter->short_opt_ch) {
 419                 iter->short_opt_ch = short_opts;
 420         }
 421
 422         /* Find corresponding option descriptor */
 423         descr = find_descr(descrs, *iter->short_opt_ch, NULL);
 424         if (!descr) {
 425                 ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
 426                 append_string_printf(error, "Unknown option `-%c`",
 427                         *iter->short_opt_ch);
 428                 goto error;
 429         }
 430
 431         if (descr->with_arg) {
 432                 if (iter->short_opt_ch[1]) {
 433                         /* `-oarg` form */
 434                         opt_arg = &iter->short_opt_ch[1];
 435                 } else {
 436                         /* `-o arg` form */
 437                         opt_arg = next_orig_arg;
 438                         used_next_orig_arg = true;
 439                 }
 440
 441                 /*
 442                  * We accept `-o ''` (empty option argument), but not
 443                  * `-o` alone if an option argument is expected.
 444                  */
 445                 if (!opt_arg || (iter->short_opt_ch[1] &&
 446                                 strlen(opt_arg) == 0)) {
 447                         append_string_printf(error,
 448                                 "Missing required argument for option `-%c`",
 449                                 *iter->short_opt_ch);
 450                         used_next_orig_arg = false;
 451                         goto error;
 452                 }
 453         }
 454
 455         /* Create and append option argument */
 456         opt_item = create_opt_item(descr, opt_arg);
 457         if (!opt_item) {
 458                 goto error;
 459         }
 460
 461         *item = &opt_item->base;
 462         iter->short_opt_ch++;
 463
 464         if (descr->with_arg || !*iter->short_opt_ch) {
 465                 /* Option has an argument: no more options */
 466                 iter->short_opt_ch = NULL;
 467
 468                 if (used_next_orig_arg) {
 469                         iter->i += 2;
 470                 } else {
 471                         iter->i++;
 472                 }
 473         }
 474
 475         goto end;
 476
 477 error:
 478         if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
 479                 ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
 480         }
 481
 482 end:
 483         return ret;
 484 }
 485
 486 static
 487 enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 488                 const char * const next_orig_arg,
 489                 const struct argpar_opt_descr * const descrs,
 490                 struct argpar_iter * const iter,
 491                 char ** const error, struct argpar_item ** const item)
 492 {
 493         const size_t max_len = 127;
 494         enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 495         const struct argpar_opt_descr *descr;
 496         struct argpar_item_opt *opt_item;
 497         bool used_next_orig_arg = false;
 498
 499         /* Option's argument, if any */
 500         const char *opt_arg = NULL;
 501
 502         /* Position of first `=`, if any */
 503         const char *eq_pos;
 504
 505         /* Buffer holding option name when `long_opt_arg` contains `=` */
 506         char buf[max_len + 1];
 507
 508         /* Option name */
 509         const char *long_opt_name = long_opt_arg;
 510
 511         if (strlen(long_opt_arg) == 0) {
 512                 append_string_printf(error, "Invalid argument");
 513                 goto error;
 514         }
 515
 516         /* Find the first `=` in original argument */
 517         eq_pos = strchr(long_opt_arg, '=');
 518         if (eq_pos) {
 519                 const size_t long_opt_name_size = eq_pos - long_opt_arg;
 520
 521                 /* Isolate the option name */
 522                 if (long_opt_name_size > max_len) {
 523                         append_string_printf(error, "Invalid argument `--%s`",
 524                                 long_opt_arg);
 525                         goto error;
 526                 }
 527
 528                 memcpy(buf, long_opt_arg, long_opt_name_size);
 529                 buf[long_opt_name_size] = '\0';
 530                 long_opt_name = buf;
 531         }
 532
 533         /* Find corresponding option descriptor */
 534         descr = find_descr(descrs, '\0', long_opt_name);
 535         if (!descr) {
 536                 append_string_printf(error, "Unknown option `--%s`",
 537                         long_opt_name);
 538                 ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
 539                 goto error;
 540         }
 541
 542         /* Find option's argument if any */
 543         if (descr->with_arg) {
 544                 if (eq_pos) {
 545                         /* `--long-opt=arg` style */
 546                         opt_arg = eq_pos + 1;
 547                 } else {
 548                         /* `--long-opt arg` style */
 549                         if (!next_orig_arg) {
 550                                 append_string_printf(error,
 551                                         "Missing required argument for option `--%s`",
 552                                         long_opt_name);
 553                                 goto error;
 554                         }
 555
 556                         opt_arg = next_orig_arg;
 557                         used_next_orig_arg = true;
 558                 }
 559         } else if (eq_pos) {
 560                 /*
 561                  * Unexpected `--opt=arg` style for a long option which
 562                  * doesn't accept an argument.
 563                  */
 564                 append_string_printf(error,
 565                         "Unexpected argument for option `--%s`", long_opt_name);
 566                 goto error;
 567         }
 568
 569         /* Create and append option argument */
 570         opt_item = create_opt_item(descr, opt_arg);
 571         if (!opt_item) {
 572                 goto error;
 573         }
 574
 575         if (used_next_orig_arg) {
 576                 iter->i += 2;
 577         } else {
 578                 iter->i++;
 579         }
 580
 581         *item = &opt_item->base;
 582         goto end;
 583
 584 error:
 585         if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
 586                 ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
 587         }
 588
 589 end:
 590         return ret;
 591 }
 592
 593 static
 594 enum parse_orig_arg_opt_ret parse_orig_arg_opt(const char * const orig_arg,
 595                 const char * const next_orig_arg,
 596                 const struct argpar_opt_descr * const descrs,
 597                 struct argpar_iter * const iter, char ** const error,
 598                 struct argpar_item ** const item)
 599 {
 600         enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 601
 602         ARGPAR_ASSERT(orig_arg[0] == '-');
 603
 604         if (orig_arg[1] == '-') {
 605                 /* Long option */
 606                 ret = parse_long_opt(&orig_arg[2],
 607                         next_orig_arg, descrs, iter, error, item);
 608         } else {
 609                 /* Short option */
 610                 ret = parse_short_opts(&orig_arg[1],
 611                         next_orig_arg, descrs, iter, error, item);
 612         }
 613
 614         return ret;
 615 }
 616
 617 static
 618 bool prepend_while_parsing_arg_to_error(char ** const error,
 619                 const unsigned int i, const char * const arg)
 620 {
 621         char *new_error;
 622         bool success;
 623
 624         ARGPAR_ASSERT(error);
 625         ARGPAR_ASSERT(*error);
 626         new_error = argpar_asprintf("While parsing argument #%u (`%s`): %s",
 627                 i + 1, arg, *error);
 628         if (!new_error) {
 629                 success = false;
 630                 goto end;
 631         }
 632
 633         free(*error);
 634         *error = new_error;
 635         success = true;
 636
 637 end:
 638         return success;
 639 }
 640
 641 ARGPAR_HIDDEN
 642 struct argpar_iter *argpar_iter_create(const unsigned int argc,
 643                 const char * const * const argv,
 644                 const struct argpar_opt_descr * const descrs)
 645 {
 646         struct argpar_iter * const iter = ARGPAR_ZALLOC(struct argpar_iter);
 647
 648         if (!iter) {
 649                 goto end;
 650         }
 651
 652         iter->argc = argc;
 653         iter->argv = argv;
 654         iter->descrs = descrs;
 655
 656 end:
 657         return iter;
 658 }
 659
 660 ARGPAR_HIDDEN
 661 void argpar_iter_destroy(struct argpar_iter * const iter)
 662 {
 663         free(iter);
 664 }
 665
 666 ARGPAR_HIDDEN
 667 enum argpar_iter_parse_next_status argpar_iter_parse_next(
 668                 struct argpar_iter * const iter,
 669                 const struct argpar_item ** const item, char ** const error)
 670 {
 671         enum argpar_iter_parse_next_status status;
 672         enum parse_orig_arg_opt_ret parse_orig_arg_opt_ret;
 673         const char *orig_arg;
 674         const char *next_orig_arg;
 675
 676         ARGPAR_ASSERT(iter->i <= iter->argc);
 677         *error = NULL;
 678
 679         if (iter->i == iter->argc) {
 680                 status = ARGPAR_ITER_PARSE_NEXT_STATUS_END;
 681                 goto end;
 682         }
 683
 684         orig_arg = iter->argv[iter->i];
 685         next_orig_arg =
 686                 iter->i < (iter->argc - 1) ? iter->argv[iter->i + 1] : NULL;
 687
 688         if (orig_arg[0] != '-') {
 689                 /* Non-option argument */
 690                 struct argpar_item_non_opt * const non_opt_item =
 691                         create_non_opt_item(orig_arg, iter->i,
 692                                 iter->non_opt_index);
 693
 694                 if (!non_opt_item) {
 695                         status = ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR;
 696                         goto end;
 697                 }
 698
 699                 iter->non_opt_index++;
 700                 iter->i++;
 701                 *item = &non_opt_item->base;
 702                 status = ARGPAR_ITER_PARSE_NEXT_STATUS_OK;
 703                 goto end;
 704         }
 705
 706         /* Option argument */
 707         parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
 708                 next_orig_arg, iter->descrs, iter, error,
 709                 (struct argpar_item **) item);
 710         switch (parse_orig_arg_opt_ret) {
 711         case PARSE_ORIG_ARG_OPT_RET_OK:
 712                 status = ARGPAR_ITER_PARSE_NEXT_STATUS_OK;
 713                 break;
 714         case PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT:
 715                 prepend_while_parsing_arg_to_error(error, iter->i, orig_arg);
 716                 status = ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT;
 717                 break;
 718         case PARSE_ORIG_ARG_OPT_RET_ERROR:
 719                 prepend_while_parsing_arg_to_error(error, iter->i, orig_arg);
 720                 status = ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR;
 721                 break;
 722         default:
 723                 abort();
 724         }
 725
 726 end:
 727         return status;
 728 }
 729
 730 ARGPAR_HIDDEN
 731 unsigned int argpar_iter_get_ingested_orig_args(
 732                 const struct argpar_iter * const iter)
 733 {
 734         return iter->i;
 735 }
 736
 737 ARGPAR_HIDDEN
 738 struct argpar_parse_ret argpar_parse(const unsigned int argc,
 739                 const char * const * const argv,
 740                 const struct argpar_opt_descr * const descrs,
 741                 const bool fail_on_unknown_opt)
 742 {
 743         struct argpar_parse_ret parse_ret = { 0 };
 744         const struct argpar_item *item = NULL;
 745         struct argpar_iter *iter = NULL;
 746
 747         parse_ret.items = create_item_array();
 748         if (!parse_ret.items) {
 749                 parse_ret.error = strdup("Failed to create items array.");
 750                 ARGPAR_ASSERT(parse_ret.error);
 751                 goto error;
 752         }
 753
 754         iter = argpar_iter_create(argc, argv, descrs);
 755         if (!iter) {
 756                 parse_ret.error = strdup("Failed to create argpar iter.");
 757                 ARGPAR_ASSERT(parse_ret.error);
 758                 goto error;
 759         }
 760
 761         while (true) {
 762                 const enum argpar_iter_parse_next_status status =
 763                         argpar_iter_parse_next(iter, &item, &parse_ret.error);
 764
 765                 if (status == ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR) {
 766                         goto error;
 767                 } else if (status == ARGPAR_ITER_PARSE_NEXT_STATUS_END) {
 768                         break;
 769                 } else if (status == ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT) {
 770                         if (fail_on_unknown_opt) {
 771                                 parse_ret.ingested_orig_args =
 772                                         argpar_iter_get_ingested_orig_args(iter);
 773                                 goto error;
 774                         }
 775
 776                         free(parse_ret.error);
 777                         parse_ret.error = NULL;
 778                         break;
 779                 }
 780
 781                 ARGPAR_ASSERT(status == ARGPAR_ITER_PARSE_NEXT_STATUS_OK);
 782
 783                 if (!push_item(parse_ret.items, item)) {
 784                         goto error;
 785                 }
 786
 787                 item = NULL;
 788         }
 789
 790         ARGPAR_ASSERT(!parse_ret.error);
 791         parse_ret.ingested_orig_args = argpar_iter_get_ingested_orig_args(iter);
 792         goto end;
 793
 794 error:
 795         ARGPAR_ASSERT(parse_ret.error);
 796
 797         /* That's how we indicate that an error occurred */
 798         destroy_item_array(parse_ret.items);
 799         parse_ret.items = NULL;
 800
 801 end:
 802         argpar_iter_destroy(iter);
 803         argpar_item_destroy(item);
 804         return parse_ret;
 805 }
 806
 807 ARGPAR_HIDDEN
 808 void argpar_parse_ret_fini(struct argpar_parse_ret * const ret)
 809 {
 810         ARGPAR_ASSERT(ret);
 811         destroy_item_array(ret->items);
 812         ret->items = NULL;
 813         free(ret->error);
 814         ret->error = NULL;
 815 }