about summary refs log blame commit diff
path: root/third_party/git/parse-options.c
blob: 87b26a1d922e8905fe369b164ae5cad7ea372426 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                                      
#include "git-compat-util.h"
#include "parse-options.h"
#include "cache.h"
#include "config.h"
#include "commit.h"
#include "color.h"
#include "utf8.h"

static int disallow_abbreviated_options;

#define OPT_SHORT 1
#define OPT_UNSET 2

int optbug(const struct option *opt, const char *reason)
{
	if (opt->long_name) {
		if (opt->short_name)
			return error("BUG: switch '%c' (--%s) %s",
				     opt->short_name, opt->long_name, reason);
		return error("BUG: option '%s' %s", opt->long_name, reason);
	}
	return error("BUG: switch '%c' %s", opt->short_name, reason);
}

static enum parse_opt_result get_arg(struct parse_opt_ctx_t *p,
				     const struct option *opt,
				     int flags, const char **arg)
{
	if (p->opt) {
		*arg = p->opt;
		p->opt = NULL;
	} else if (p->argc == 1 && (opt->flags & PARSE_OPT_LASTARG_DEFAULT)) {
		*arg = (const char *)opt->defval;
	} else if (p->argc > 1) {
		p->argc--;
		*arg = *++p->argv;
	} else
		return error(_("%s requires a value"), optname(opt, flags));
	return 0;
}

static void fix_filename(const char *prefix, const char **file)
{
	if (!file || !*file || !prefix || is_absolute_path(*file)
	    || !strcmp("-", *file))
		return;
	*file = prefix_filename(prefix, *file);
}

static enum parse_opt_result opt_command_mode_error(
	const struct option *opt,
	const struct option *all_opts,
	int flags)
{
	const struct option *that;
	struct strbuf that_name = STRBUF_INIT;

	/*
	 * Find the other option that was used to set the variable
	 * already, and report that this is not compatible with it.
	 */
	for (that = all_opts; that->type != OPTION_END; that++) {
		if (that == opt ||
		    that->type != OPTION_CMDMODE ||
		    that->value != opt->value ||
		    that->defval != *(int *)opt->value)
			continue;

		if (that->long_name)
			strbuf_addf(&that_name, "--%s", that->long_name);
		else
			strbuf_addf(&that_name, "-%c", that->short_name);
		error(_("%s is incompatible with %s"),
		      optname(opt, flags), that_name.buf);
		strbuf_release(&that_name);
		return PARSE_OPT_ERROR;
	}
	return error(_("%s : incompatible with something else"),
		     optname(opt, flags));
}

static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
				       const struct option *opt,
				       const struct option *all_opts,
				       int flags)
{
	const char *s, *arg;
	const int unset = flags & OPT_UNSET;
	int err;

	if (unset && p->opt)
		return error(_("%s takes no value"), optname(opt, flags));
	if (unset && (opt->flags & PARSE_OPT_NONEG))
		return error(_("%s isn't available"), optname(opt, flags));
	if (!(flags & OPT_SHORT) && p->opt && (opt->flags & PARSE_OPT_NOARG))
		return error(_("%s takes no value"), optname(opt, flags));

	switch (opt->type) {
	case OPTION_LOWLEVEL_CALLBACK:
		return opt->ll_callback(p, opt, NULL, unset);

	case OPTION_BIT:
		if (unset)
			*(int *)opt->value &= ~opt->defval;
		else
			*(int *)opt->value |= opt->defval;
		return 0;

	case OPTION_NEGBIT:
		if (unset)
			*(int *)opt->value |= opt->defval;
		else
			*(int *)opt->value &= ~opt->defval;
		return 0;

	case OPTION_BITOP:
		if (unset)
			BUG("BITOP can't have unset form");
		*(int *)opt->value &= ~opt->extra;
		*(int *)opt->value |= opt->defval;
		return 0;

	case OPTION_COUNTUP:
		if (*(int *)opt->value < 0)
			*(int *)opt->value = 0;
		*(int *)opt->value = unset ? 0 : *(int *)opt->value + 1;
		return 0;

	case OPTION_SET_INT:
		*(int *)opt->value = unset ? 0 : opt->defval;
		return 0;

	case OPTION_CMDMODE:
		/*
		 * Giving the same mode option twice, although is unnecessary,
		 * is not a grave error, so let it pass.
		 */
		if (*(int *)opt->value && *(int *)opt->value != opt->defval)
			return opt_command_mode_error(opt, all_opts, flags);
		*(int *)opt->value = opt->defval;
		return 0;

	case OPTION_STRING:
		if (unset)
			*(const char **)opt->value = NULL;
		else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
			*(const char **)opt->value = (const char *)opt->defval;
		else
			return get_arg(p, opt, flags, (const char **)opt->value);
		return 0;

	case OPTION_FILENAME:
		err = 0;
		if (unset)
			*(const char **)opt->value = NULL;
		else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
			*(const char **)opt->value = (const char *)opt->defval;
		else
			err = get_arg(p, opt, flags, (const char **)opt->value);

		if (!err)
			fix_filename(p->prefix, (const char **)opt->value);
		return err;

	case OPTION_CALLBACK:
	{
		const char *p_arg = NULL;
		int p_unset;

		if (unset)
			p_unset = 1;
		else if (opt->flags & PARSE_OPT_NOARG)
			p_unset = 0;
		else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
			p_unset = 0;
		else if (get_arg(p, opt, flags, &arg))
			return -1;
		else {
			p_unset = 0;
			p_arg = arg;
		}
		if (opt->callback)
			return (*opt->callback)(opt, p_arg, p_unset) ? (-1) : 0;
		else
			return (*opt->ll_callback)(p, opt, p_arg, p_unset);
	}
	case OPTION_INTEGER:
		if (unset) {
			*(int *)opt->value = 0;
			return 0;
		}
		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
			*(int *)opt->value = opt->defval;
			return 0;
		}
		if (get_arg(p, opt, flags, &arg))
			return -1;
		if (!*arg)
			return error(_("%s expects a numerical value"),
				     optname(opt, flags));
		*(int *)opt->value = strtol(arg, (char **)&s, 10);
		if (*s)
			return error(_("%s expects a numerical value"),
				     optname(opt, flags));
		return 0;

	case OPTION_MAGNITUDE:
		if (unset) {
			*(unsigned long *)opt->value = 0;
			return 0;
		}
		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
			*(unsigned long *)opt->value = opt->defval;
			return 0;
		}
		if (get_arg(p, opt, flags, &arg))
			return -1;
		if (!git_parse_ulong(arg, opt->value))
			return error(_("%s expects a non-negative integer value"
				       " with an optional k/m/g suffix"),
				     optname(opt, flags));
		return 0;

	default:
		BUG("opt->type %d should not happen", opt->type);
	}
}

static enum parse_opt_result parse_short_opt(struct parse_opt_ctx_t *p,
					     const struct option *options)
{
	const struct option *all_opts = options;
	const struct option *numopt = NULL;

	for (; options->type != OPTION_END; options++) {
		if (options->short_name == *p->opt) {
			p->opt = p->opt[1] ? p->opt + 1 : NULL;
			return get_value(p, options, all_opts, OPT_SHORT);
		}

		/*
		 * Handle the numerical option later, explicit one-digit
		 * options take precedence over it.
		 */
		if (options->type == OPTION_NUMBER)
			numopt = options;
	}
	if (numopt && isdigit(*p->opt)) {
		size_t len = 1;
		char *arg;
		int rc;

		while (isdigit(p->opt[len]))
			len++;
		arg = xmemdupz(p->opt, len);
		p->opt = p->opt[len] ? p->opt + len : NULL;
		if (numopt->callback)
			rc = (*numopt->callback)(numopt, arg, 0) ? (-1) : 0;
		else
			rc = (*numopt->ll_callback)(p, numopt, arg, 0);
		free(arg);
		return rc;
	}
	return PARSE_OPT_UNKNOWN;
}

static int has_string(const char *it, const char **array)
{
	while (*array)
		if (!strcmp(it, *(array++)))
			return 1;
	return 0;
}

static int is_alias(struct parse_opt_ctx_t *ctx,
		    const struct option *one_opt,
		    const struct option *another_opt)
{
	const char **group;

	if (!ctx->alias_groups)
		return 0;

	if (!one_opt->long_name || !another_opt->long_name)
		return 0;

	for (group = ctx->alias_groups; *group; group += 3) {
		/* it and other are from the same family? */
		if (has_string(one_opt->long_name, group) &&
		    has_string(another_opt->long_name, group))
			return 1;
	}
	return 0;
}

static enum parse_opt_result parse_long_opt(
	struct parse_opt_ctx_t *p, const char *arg,
	const struct option *options)
{
	const struct option *all_opts = options;
	const char *arg_end = strchrnul(arg, '=');
	const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
	int abbrev_flags = 0, ambiguous_flags = 0;

	for (; options->type != OPTION_END; options++) {
		const char *rest, *long_name = options->long_name;
		int flags = 0, opt_flags = 0;

		if (!long_name)
			continue;

again:
		if (!skip_prefix(arg, long_name, &rest))
			rest = NULL;
		if (options->type == OPTION_ARGUMENT) {
			if (!rest)
				continue;
			if (*rest == '=')
				return error(_("%s takes no value"),
					     optname(options, flags));
			if (*rest)
				continue;
			if (options->value)
				*(int *)options->value = options->defval;
			p->out[p->cpidx++] = arg - 2;
			return PARSE_OPT_DONE;
		}
		if (!rest) {
			/* abbreviated? */
			if (!(p->flags & PARSE_OPT_KEEP_UNKNOWN) &&
			    !strncmp(long_name, arg, arg_end - arg)) {
is_abbreviated:
				if (abbrev_option &&
				    !is_alias(p, abbrev_option, options)) {
					/*
					 * If this is abbreviated, it is
					 * ambiguous. So when there is no
					 * exact match later, we need to
					 * error out.
					 */
					ambiguous_option = abbrev_option;
					ambiguous_flags = abbrev_flags;
				}
				if (!(flags & OPT_UNSET) && *arg_end)
					p->opt = arg_end + 1;
				abbrev_option = options;
				abbrev_flags = flags ^ opt_flags;
				continue;
			}
			/* negation allowed? */
			if (options->flags & PARSE_OPT_NONEG)
				continue;
			/* negated and abbreviated very much? */
			if (starts_with("no-", arg)) {
				flags |= OPT_UNSET;
				goto is_abbreviated;
			}
			/* negated? */
			if (!starts_with(arg, "no-")) {
				if (starts_with(long_name, "no-")) {
					long_name += 3;
					opt_flags |= OPT_UNSET;
					goto again;
				}
				continue;
			}
			flags |= OPT_UNSET;
			if (!skip_prefix(arg + 3, long_name, &rest)) {
				/* abbreviated and negated? */
				if (starts_with(long_name, arg + 3))
					goto is_abbreviated;
				else
					continue;
			}
		}
		if (*rest) {
			if (*rest != '=')
				continue;
			p->opt = rest + 1;
		}
		return get_value(p, options, all_opts, flags ^ opt_flags);
	}

	if (disallow_abbreviated_options && (ambiguous_option || abbrev_option))
		die("disallowed abbreviated or ambiguous option '%.*s'",
		    (int)(arg_end - arg), arg);

	if (ambiguous_option) {
		error(_("ambiguous option: %s "
			"(could be --%s%s or --%s%s)"),
			arg,
			(ambiguous_flags & OPT_UNSET) ?  "no-" : "",
			ambiguous_option->long_name,
			(abbrev_flags & OPT_UNSET) ?  "no-" : "",
			abbrev_option->long_name);
		return PARSE_OPT_HELP;
	}
	if (abbrev_option)
		return get_value(p, abbrev_option, all_opts, abbrev_flags);
	return PARSE_OPT_UNKNOWN;
}

static int parse_nodash_opt(struct parse_opt_ctx_t *p, const char *arg,
			    const struct option *options)
{
	const struct option *all_opts = options;

	for (; options->type != OPTION_END; options++) {
		if (!(options->flags & PARSE_OPT_NODASH))
			continue;
		if (options->short_name == arg[0] && arg[1] == '\0')
			return get_value(p, options, all_opts, OPT_SHORT);
	}
	return -2;
}

static void check_typos(const char *arg, const struct option *options)
{
	if (strlen(arg) < 3)
		return;

	if (starts_with(arg, "no-")) {
		error(_("did you mean `--%s` (with two dashes ?)"), arg);
		exit(129);
	}

	for (; options->type != OPTION_END; options++) {
		if (!options->long_name)
			continue;
		if (starts_with(options->long_name, arg)) {
			error(_("did you mean `--%s` (with two dashes ?)"), arg);
			exit(129);
		}
	}
}

static void parse_options_check(const struct option *opts)
{
	int err = 0;
	char short_opts[128];

	memset(short_opts, '\0', sizeof(short_opts));
	for (; opts->type != OPTION_END; opts++) {
		if ((opts->flags & PARSE_OPT_LASTARG_DEFAULT) &&
		    (opts->flags & PARSE_OPT_OPTARG))
			err |= optbug(opts, "uses incompatible flags "
					"LASTARG_DEFAULT and OPTARG");
		if (opts->short_name) {
			if (0x7F <= opts->short_name)
				err |= optbug(opts, "invalid short name");
			else if (short_opts[opts->short_name]++)
				err |= optbug(opts, "short name already used");
		}
		if (opts->flags & PARSE_OPT_NODASH &&
		    ((opts->flags & PARSE_OPT_OPTARG) ||
		     !(opts->flags & PARSE_OPT_NOARG) ||
		     !(opts->flags & PARSE_OPT_NONEG) ||
		     opts->long_name))
			err |= optbug(opts, "uses feature "
					"not supported for dashless options");
		switch (opts->type) {
		case OPTION_COUNTUP:
		case OPTION_BIT:
		case OPTION_NEGBIT:
		case OPTION_SET_INT:
		case OPTION_NUMBER:
			if ((opts->flags & PARSE_OPT_OPTARG) ||
			    !(opts->flags & PARSE_OPT_NOARG))
				err |= optbug(opts, "should not accept an argument");
			break;
		case OPTION_CALLBACK:
			if (!opts->callback && !opts->ll_callback)
				BUG("OPTION_CALLBACK needs one callback");
			if (opts->callback && opts->ll_callback)
				BUG("OPTION_CALLBACK can't have two callbacks");
			break;
		case OPTION_LOWLEVEL_CALLBACK:
			if (!opts->ll_callback)
				BUG("OPTION_LOWLEVEL_CALLBACK needs a callback");
			if (opts->callback)
				BUG("OPTION_LOWLEVEL_CALLBACK needs no high level callback");
			break;
		case OPTION_ALIAS:
			BUG("OPT_ALIAS() should not remain at this point. "
			    "Are you using parse_options_step() directly?\n"
			    "That case is not supported yet.");
		default:
			; /* ok. (usually accepts an argument) */
		}
		if (opts->argh &&
		    strcspn(opts->argh, " _") != strlen(opts->argh))
			err |= optbug(opts, "multi-word argh should use dash to separate words");
	}
	if (err)
		exit(128);
}

static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
				  int argc, const char **argv, const char *prefix,
				  const struct option *options, int flags)
{
	ctx->argc = argc;
	ctx->argv = argv;
	if (!(flags & PARSE_OPT_ONE_SHOT)) {
		ctx->argc--;
		ctx->argv++;
	}
	ctx->total = ctx->argc;
	ctx->out   = argv;
	ctx->prefix = prefix;
	ctx->cpidx = ((flags & PARSE_OPT_KEEP_ARGV0) != 0);
	ctx->flags = flags;
	if ((flags & PARSE_OPT_KEEP_UNKNOWN) &&
	    (flags & PARSE_OPT_STOP_AT_NON_OPTION) &&
	    !(flags & PARSE_OPT_ONE_SHOT))
		BUG("STOP_AT_NON_OPTION and KEEP_UNKNOWN don't go together");
	if ((flags & PARSE_OPT_ONE_SHOT) &&
	    (flags & PARSE_OPT_KEEP_ARGV0))
		BUG("Can't keep argv0 if you don't have it");
	parse_options_check(options);
}

void parse_options_start(struct parse_opt_ctx_t *ctx,
			 int argc, const char **argv, const char *prefix,
			 const struct option *options, int flags)
{
	memset(ctx, 0, sizeof(*ctx));
	parse_options_start_1(ctx, argc, argv, prefix, options, flags);
}

static void show_negated_gitcomp(const struct option *opts, int nr_noopts)
{
	int printed_dashdash = 0;

	for (; opts->type != OPTION_END; opts++) {
		int has_unset_form = 0;
		const char *name;

		if (!opts->long_name)
			continue;
		if (opts->flags & (PARSE_OPT_HIDDEN | PARSE_OPT_NOCOMPLETE))
			continue;
		if (opts->flags & PARSE_OPT_NONEG)
			continue;

		switch (opts->type) {
		case OPTION_STRING:
		case OPTION_FILENAME:
		case OPTION_INTEGER:
		case OPTION_MAGNITUDE:
		case OPTION_CALLBACK:
		case OPTION_BIT:
		case OPTION_NEGBIT:
		case OPTION_COUNTUP:
		case OPTION_SET_INT:
			has_unset_form = 1;
			break;
		default:
			break;
		}
		if (!has_unset_form)
			continue;

		if (skip_prefix(opts->long_name, "no-", &name)) {
			if (nr_noopts < 0)
				printf(" --%s", name);
		} else if (nr_noopts >= 0) {
			if (nr_noopts && !printed_dashdash) {
				printf(" --");
				printed_dashdash = 1;
			}
			printf(" --no-%s", opts->long_name);
			nr_noopts++;
		}
	}
}

static int show_gitcomp(const struct option *opts)
{
	const struct option *original_opts = opts;
	int nr_noopts = 0;

	for (; opts->type != OPTION_END; opts++) {
		const char *suffix = "";

		if (!opts->long_name)
			continue;
		if (opts->flags & (PARSE_OPT_HIDDEN | PARSE_OPT_NOCOMPLETE))
			continue;

		switch (opts->type) {
		case OPTION_GROUP:
			continue;
		case OPTION_STRING:
		case OPTION_FILENAME:
		case OPTION_INTEGER:
		case OPTION_MAGNITUDE:
		case OPTION_CALLBACK:
			if (opts->flags & PARSE_OPT_NOARG)
				break;
			if (opts->flags & PARSE_OPT_OPTARG)
				break;
			if (opts->flags & PARSE_OPT_LASTARG_DEFAULT)
				break;
			suffix = "=";
			break;
		default:
			break;
		}
		if (opts->flags & PARSE_OPT_COMP_ARG)
			suffix = "=";
		if (starts_with(opts->long_name, "no-"))
			nr_noopts++;
		printf(" --%s%s", opts->long_name, suffix);
	}
	show_negated_gitcomp(original_opts, -1);
	show_negated_gitcomp(original_opts, nr_noopts);
	fputc('\n', stdout);
	return PARSE_OPT_COMPLETE;
}

/*
 * Scan and may produce a new option[] array, which should be used
 * instead of the original 'options'.
 *
 * Right now this is only used to preprocess and substitue
 * OPTION_ALIAS.
 */
static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
					 const struct option *options)
{
	struct option *newopt;
	int i, nr, alias;
	int nr_aliases = 0;

	for (nr = 0; options[nr].type != OPTION_END; nr++) {
		if (options[nr].type == OPTION_ALIAS)
			nr_aliases++;
	}

	if (!nr_aliases)
		return NULL;

	ALLOC_ARRAY(newopt, nr + 1);
	COPY_ARRAY(newopt, options, nr + 1);

	/* each alias has two string pointers and NULL */
	CALLOC_ARRAY(ctx->alias_groups, 3 * (nr_aliases + 1));

	for (alias = 0, i = 0; i < nr; i++) {
		int short_name;
		const char *long_name;
		const char *source;
		int j;

		if (newopt[i].type != OPTION_ALIAS)
			continue;

		short_name = newopt[i].short_name;
		long_name = newopt[i].long_name;
		source = newopt[i].value;

		if (!long_name)
			BUG("An alias must have long option name");

		for (j = 0; j < nr; j++) {
			const char *name = options[j].long_name;

			if (!name || strcmp(name, source))
				continue;

			if (options[j].type == OPTION_ALIAS)
				BUG("No please. Nested aliases are not supported.");

			/*
			 * NEEDSWORK: this is a bit inconsistent because
			 * usage_with_options() on the original options[] will print
			 * help string as "alias of %s" but "git cmd -h" will
			 * print the original help string.
			 */
			memcpy(newopt + i, options + j, sizeof(*newopt));
			newopt[i].short_name = short_name;
			newopt[i].long_name = long_name;
			break;
		}

		if (j == nr)
			BUG("could not find source option '%s' of alias '%s'",
			    source, newopt[i].long_name);
		ctx->alias_groups[alias * 3 + 0] = newopt[i].long_name;
		ctx->alias_groups[alias * 3 + 1] = options[j].long_name;
		ctx->alias_groups[alias * 3 + 2] = NULL;
		alias++;
	}

	return newopt;
}

static int usage_with_options_internal(struct parse_opt_ctx_t *,
				       const char * const *,
				       const struct option *, int, int);

int parse_options_step(struct parse_opt_ctx_t *ctx,
		       const struct option *options,
		       const char * const usagestr[])
{
	int internal_help = !(ctx->flags & PARSE_OPT_NO_INTERNAL_HELP);

	/* we must reset ->opt, unknown short option leave it dangling */
	ctx->opt = NULL;

	for (; ctx->argc; ctx->argc--, ctx->argv++) {
		const char *arg = ctx->argv[0];

		if (ctx->flags & PARSE_OPT_ONE_SHOT &&
		    ctx->argc != ctx->total)
			break;

		if (*arg != '-' || !arg[1]) {
			if (parse_nodash_opt(ctx, arg, options) == 0)
				continue;
			if (ctx->flags & PARSE_OPT_STOP_AT_NON_OPTION)
				return PARSE_OPT_NON_OPTION;
			ctx->out[ctx->cpidx++] = ctx->argv[0];
			continue;
		}

		/* lone -h asks for help */
		if (internal_help && ctx->total == 1 && !strcmp(arg + 1, "h"))
			goto show_usage;

		/* lone --git-completion-helper is asked by git-completion.bash */
		if (ctx->total == 1 && !strcmp(arg + 1, "-git-completion-helper"))
			return show_gitcomp(options);

		if (arg[1] != '-') {
			ctx->opt = arg + 1;
			switch (parse_short_opt(ctx, options)) {
			case PARSE_OPT_ERROR:
				return PARSE_OPT_ERROR;
			case PARSE_OPT_UNKNOWN:
				if (ctx->opt)
					check_typos(arg + 1, options);
				if (internal_help && *ctx->opt == 'h')
					goto show_usage;
				goto unknown;
			case PARSE_OPT_NON_OPTION:
			case PARSE_OPT_HELP:
			case PARSE_OPT_COMPLETE:
				BUG("parse_short_opt() cannot return these");
			case PARSE_OPT_DONE:
				break;
			}
			if (ctx->opt)
				check_typos(arg + 1, options);
			while (ctx->opt) {
				switch (parse_short_opt(ctx, options)) {
				case PARSE_OPT_ERROR:
					return PARSE_OPT_ERROR;
				case PARSE_OPT_UNKNOWN:
					if (internal_help && *ctx->opt == 'h')
						goto show_usage;

					/* fake a short option thing to hide the fact that we may have
					 * started to parse aggregated stuff
					 *
					 * This is leaky, too bad.
					 */
					ctx->argv[0] = xstrdup(ctx->opt - 1);
					*(char *)ctx->argv[0] = '-';
					goto unknown;
				case PARSE_OPT_NON_OPTION:
				case PARSE_OPT_COMPLETE:
				case PARSE_OPT_HELP:
					BUG("parse_short_opt() cannot return these");
				case PARSE_OPT_DONE:
					break;
				}
			}
			continue;
		}

		if (!arg[2]) { /* "--" */
			if (!(ctx->flags & PARSE_OPT_KEEP_DASHDASH)) {
				ctx->argc--;
				ctx->argv++;
			}
			break;
		}

		if (internal_help && !strcmp(arg + 2, "help-all"))
			return usage_with_options_internal(ctx, usagestr, options, 1, 0);
		if (internal_help && !strcmp(arg + 2, "help"))
			goto show_usage;
		switch (parse_long_opt(ctx, arg + 2, options)) {
		case PARSE_OPT_ERROR:
			return PARSE_OPT_ERROR;
		case PARSE_OPT_UNKNOWN:
			goto unknown;
		case PARSE_OPT_HELP:
			goto show_usage;
		case PARSE_OPT_NON_OPTION:
		case PARSE_OPT_COMPLETE:
			BUG("parse_long_opt() cannot return these");
		case PARSE_OPT_DONE:
			break;
		}
		continue;
unknown:
		if (ctx->flags & PARSE_OPT_ONE_SHOT)
			break;
		if (!(ctx->flags & PARSE_OPT_KEEP_UNKNOWN))
			return PARSE_OPT_UNKNOWN;
		ctx->out[ctx->cpidx++] = ctx->argv[0];
		ctx->opt = NULL;
	}
	return PARSE_OPT_DONE;

 show_usage:
	return usage_with_options_internal(ctx, usagestr, options, 0, 0);
}

int parse_options_end(struct parse_opt_ctx_t *ctx)
{
	if (ctx->flags & PARSE_OPT_ONE_SHOT)
		return ctx->total - ctx->argc;

	MOVE_ARRAY(ctx->out + ctx->cpidx, ctx->argv, ctx->argc);
	ctx->out[ctx->cpidx + ctx->argc] = NULL;
	return ctx->cpidx + ctx->argc;
}

int parse_options(int argc, const char **argv, const char *prefix,
		  const struct option *options, const char * const usagestr[],
		  int flags)
{
	struct parse_opt_ctx_t ctx;
	struct option *real_options;

	disallow_abbreviated_options =
		git_env_bool("GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS", 0);

	memset(&ctx, 0, sizeof(ctx));
	real_options = preprocess_options(&ctx, options);
	if (real_options)
		options = real_options;
	parse_options_start_1(&ctx, argc, argv, prefix, options, flags);
	switch (parse_options_step(&ctx, options, usagestr)) {
	case PARSE_OPT_HELP:
	case PARSE_OPT_ERROR:
		exit(129);
	case PARSE_OPT_COMPLETE:
		exit(0);
	case PARSE_OPT_NON_OPTION:
	case PARSE_OPT_DONE:
		break;
	default: /* PARSE_OPT_UNKNOWN */
		if (ctx.argv[0][1] == '-') {
			error(_("unknown option `%s'"), ctx.argv[0] + 2);
		} else if (isascii(*ctx.opt)) {
			error(_("unknown switch `%c'"), *ctx.opt);
		} else {
			error(_("unknown non-ascii option in string: `%s'"),
			      ctx.argv[0]);
		}
		usage_with_options(usagestr, options);
	}

	precompose_argv(argc, argv);
	free(real_options);
	free(ctx.alias_groups);
	return parse_options_end(&ctx);
}

static int usage_argh(const struct option *opts, FILE *outfile)
{
	const char *s;
	int literal = (opts->flags & PARSE_OPT_LITERAL_ARGHELP) ||
		!opts->argh || !!strpbrk(opts->argh, "()<>[]|");
	if (opts->flags & PARSE_OPT_OPTARG)
		if (opts->long_name)
			s = literal ? "[=%s]" : "[=<%s>]";
		else
			s = literal ? "[%s]" : "[<%s>]";
	else
		s = literal ? " %s" : " <%s>";
	return utf8_fprintf(outfile, s, opts->argh ? _(opts->argh) : _("..."));
}

#define USAGE_OPTS_WIDTH 24
#define USAGE_GAP         2

static int usage_with_options_internal(struct parse_opt_ctx_t *ctx,
				       const char * const *usagestr,
				       const struct option *opts, int full, int err)
{
	FILE *outfile = err ? stderr : stdout;
	int need_newline;

	if (!usagestr)
		return PARSE_OPT_HELP;

	if (!err && ctx && ctx->flags & PARSE_OPT_SHELL_EVAL)
		fprintf(outfile, "cat <<\\EOF\n");

	fprintf_ln(outfile, _("usage: %s"), _(*usagestr++));
	while (*usagestr && **usagestr)
		/*
		 * TRANSLATORS: the colon here should align with the
		 * one in "usage: %s" translation.
		 */
		fprintf_ln(outfile, _("   or: %s"), _(*usagestr++));
	while (*usagestr) {
		if (**usagestr)
			fprintf_ln(outfile, _("    %s"), _(*usagestr));
		else
			fputc('\n', outfile);
		usagestr++;
	}

	need_newline = 1;

	for (; opts->type != OPTION_END; opts++) {
		size_t pos;
		int pad;

		if (opts->type == OPTION_GROUP) {
			fputc('\n', outfile);
			need_newline = 0;
			if (*opts->help)
				fprintf(outfile, "%s\n", _(opts->help));
			continue;
		}
		if (!full && (opts->flags & PARSE_OPT_HIDDEN))
			continue;

		if (need_newline) {
			fputc('\n', outfile);
			need_newline = 0;
		}

		pos = fprintf(outfile, "    ");
		if (opts->short_name) {
			if (opts->flags & PARSE_OPT_NODASH)
				pos += fprintf(outfile, "%c", opts->short_name);
			else
				pos += fprintf(outfile, "-%c", opts->short_name);
		}
		if (opts->long_name && opts->short_name)
			pos += fprintf(outfile, ", ");
		if (opts->long_name)
			pos += fprintf(outfile, "--%s", opts->long_name);
		if (opts->type == OPTION_NUMBER)
			pos += utf8_fprintf(outfile, _("-NUM"));

		if ((opts->flags & PARSE_OPT_LITERAL_ARGHELP) ||
		    !(opts->flags & PARSE_OPT_NOARG))
			pos += usage_argh(opts, outfile);

		if (pos <= USAGE_OPTS_WIDTH)
			pad = USAGE_OPTS_WIDTH - pos;
		else {
			fputc('\n', outfile);
			pad = USAGE_OPTS_WIDTH;
		}
		if (opts->type == OPTION_ALIAS) {
			fprintf(outfile, "%*s", pad + USAGE_GAP, "");
			fprintf_ln(outfile, _("alias of --%s"),
				   (const char *)opts->value);
			continue;
		}
		fprintf(outfile, "%*s%s\n", pad + USAGE_GAP, "", _(opts->help));
	}
	fputc('\n', outfile);

	if (!err && ctx && ctx->flags & PARSE_OPT_SHELL_EVAL)
		fputs("EOF\n", outfile);

	return PARSE_OPT_HELP;
}

void NORETURN usage_with_options(const char * const *usagestr,
			const struct option *opts)
{
	usage_with_options_internal(NULL, usagestr, opts, 0, 1);
	exit(129);
}

void NORETURN usage_msg_opt(const char *msg,
		   const char * const *usagestr,
		   const struct option *options)
{
	fprintf(stderr, "fatal: %s\n\n", msg);
	usage_with_options(usagestr, options);
}

const char *optname(const struct option *opt, int flags)
{
	static struct strbuf sb = STRBUF_INIT;

	strbuf_reset(&sb);
	if (flags & OPT_SHORT)
		strbuf_addf(&sb, "switch `%c'", opt->short_name);
	else if (flags & OPT_UNSET)
		strbuf_addf(&sb, "option `no-%s'", opt->long_name);
	else
		strbuf_addf(&sb, "option `%s'", opt->long_name);

	return sb.buf;
}