[lttng-tools.git] / src / common / argpar / argpar.c

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright 2019 Philippe Proulx <pproulx@efficios.com>
 */

#include <assert.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "argpar.h"

#define argpar_realloc(_ptr, _type, _nmemb) ((_type *) realloc(_ptr, (_nmemb) * sizeof(_type)))
#define argpar_calloc(_type, _nmemb) ((_type *) calloc((_nmemb), sizeof(_type)))
#define argpar_zalloc(_type) argpar_calloc(_type, 1)

#define ARGPAR_ASSERT(_cond) assert(_cond)

#ifdef __MINGW_PRINTF_FORMAT
# define ARGPAR_PRINTF_FORMAT __MINGW_PRINTF_FORMAT
#else
# define ARGPAR_PRINTF_FORMAT printf
#endif

/*
 * Structure holding the argpar state between successive argpar_state_parse_next
 * calls.
 *
 * Created with `argpar_state_create` and destroyed with `argpar_state_destroy`.
 */
struct argpar_state {
	/*
	 * Data provided by the user in argpar_state_create, does not change
	 * afterwards.
	 */
	unsigned int argc;
	const char * const *argv;
	const struct argpar_opt_descr *descrs;

	/*
	 * Index of the argument to process in the next argpar_state_parse_next
	 * call.
	 */
	unsigned int i;

	/* Counter of non-option arguments. */
	int non_opt_index;

	/*
	 * Short option state: if set, we are in the middle of a short option
	 * group, so we should resume there at the next argpar_state_parse_next
	 * call.
	 */
	const char *short_opt_ch;
};

static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 0)))
char *argpar_vasprintf(const char *fmt, va_list args)
{
	int len1, len2;
	char *str;
	va_list args2;

	va_copy(args2, args);

	len1 = vsnprintf(NULL, 0, fmt, args);
	if (len1 < 0) {
		str = NULL;
		goto end;
	}

	str = malloc(len1 + 1);
	if (!str) {
		goto end;
	}

	len2 = vsnprintf(str, len1 + 1, fmt, args2);

	ARGPAR_ASSERT(len1 == len2);

end:
	va_end(args2);
	return str;
}


static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 2)))
char *argpar_asprintf(const char *fmt, ...)
{
	va_list args;
	char *str;

	va_start(args, fmt);
	str = argpar_vasprintf(fmt, args);
	va_end(args);

	return str;
}

static  __attribute__((format(ARGPAR_PRINTF_FORMAT, 2, 3)))
bool argpar_string_append_printf(char **str, const char *fmt, ...)
{
	char *new_str = NULL;
	char *addendum;
	bool success;
	va_list args;

	ARGPAR_ASSERT(str);

	va_start(args, fmt);
	addendum = argpar_vasprintf(fmt, args);
	va_end(args);

	if (!addendum) {
		success = false;
		goto end;
	}

	new_str = argpar_asprintf("%s%s", *str ? *str : "", addendum);
	if (!new_str) {
		success = false;
		goto end;
	}

	free(*str);
	*str = new_str;

	success = true;

end:
	free(addendum);

	return success;
}

ARGPAR_HIDDEN
void argpar_item_destroy(struct argpar_item *item)
{
	if (!item) {
		goto end;
	}

	if (item->type == ARGPAR_ITEM_TYPE_OPT) {
		struct argpar_item_opt * const opt_item = (void *) item;

		free((void *) opt_item->arg);
	}

	free(item);

end:
	return;
}

static
bool push_item(struct argpar_item_array * const array,
		struct argpar_item * const item)
{
	bool success;

	ARGPAR_ASSERT(array);
	ARGPAR_ASSERT(item);

	if (array->n_items == array->n_alloc) {
		unsigned int new_n_alloc = array->n_alloc * 2;
		struct argpar_item **new_items;

		new_items = argpar_realloc(array->items,
			struct argpar_item *, new_n_alloc);
		if (!new_items) {
			success = false;
			goto end;
		}

		array->n_alloc = new_n_alloc;
		array->items = new_items;
	}

	array->items[array->n_items] = item;
	array->n_items++;

	success = true;

end:
	return success;
}

static
void destroy_item_array(struct argpar_item_array * const array)
{
	if (array) {
		unsigned int i;

		for (i = 0; i < array->n_items; i++) {
			argpar_item_destroy(array->items[i]);
		}

		free(array->items);
		free(array);
	}
}

static
struct argpar_item_array *new_item_array(void)
{
	struct argpar_item_array *ret;
	const int initial_size = 10;

	ret = argpar_zalloc(struct argpar_item_array);
	if (!ret) {
		goto end;
	}

	ret->items = argpar_calloc(struct argpar_item *, initial_size);
	if (!ret->items) {
		goto error;
	}

	ret->n_alloc = initial_size;

	goto end;

error:
	destroy_item_array(ret);
	ret = NULL;

end:
	return ret;
}

static
struct argpar_item_opt *create_opt_item(
		const struct argpar_opt_descr * const descr,
		const char * const arg)
{
	struct argpar_item_opt *opt_item =
		argpar_zalloc(struct argpar_item_opt);

	if (!opt_item) {
		goto end;
	}

	opt_item->base.type = ARGPAR_ITEM_TYPE_OPT;
	opt_item->descr = descr;

	if (arg) {
		opt_item->arg = strdup(arg);
		if (!opt_item->arg) {
			goto error;
		}
	}

	goto end;

error:
	argpar_item_destroy(&opt_item->base);
	opt_item = NULL;

end:
	return opt_item;
}

static
struct argpar_item_non_opt *create_non_opt_item(const char * const arg,
		const unsigned int orig_index,
		const unsigned int non_opt_index)
{
	struct argpar_item_non_opt * const non_opt_item =
		argpar_zalloc(struct argpar_item_non_opt);

	if (!non_opt_item) {
		goto end;
	}

	non_opt_item->base.type = ARGPAR_ITEM_TYPE_NON_OPT;
	non_opt_item->arg = arg;
	non_opt_item->orig_index = orig_index;
	non_opt_item->non_opt_index = non_opt_index;

end:
	return non_opt_item;
}

static
const struct argpar_opt_descr *find_descr(
		const struct argpar_opt_descr * const descrs,
		const char short_name, const char * const long_name)
{
	const struct argpar_opt_descr *descr;

	for (descr = descrs; descr->short_name || descr->long_name; descr++) {
		if (short_name && descr->short_name &&
				short_name == descr->short_name) {
			goto end;
		}

		if (long_name && descr->long_name &&
				strcmp(long_name, descr->long_name) == 0) {
			goto end;
		}
	}

end:
	return !descr->short_name && !descr->long_name ? NULL : descr;
}

enum parse_orig_arg_opt_ret {
	PARSE_ORIG_ARG_OPT_RET_OK,
	PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT = -2,
	PARSE_ORIG_ARG_OPT_RET_ERROR = -1,
};

static
enum parse_orig_arg_opt_ret parse_short_opts(const char * const short_opts,
		const char * const next_orig_arg,
		const struct argpar_opt_descr * const descrs,
		struct argpar_state *state,
		char **error,
		struct argpar_item **item)
{
	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
	bool used_next_orig_arg = false;

	if (strlen(short_opts) == 0) {
		argpar_string_append_printf(error, "Invalid argument");
		goto error;
	}

	if (!state->short_opt_ch) {
		state->short_opt_ch = short_opts;
	}

	const char *opt_arg = NULL;
	const struct argpar_opt_descr *descr;
	struct argpar_item_opt *opt_item;

	/* Find corresponding option descriptor */
	descr = find_descr(descrs, *state->short_opt_ch, NULL);
	if (!descr) {
		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
		argpar_string_append_printf(error,
			"Unknown option `-%c`", *state->short_opt_ch);
		goto error;
	}

	if (descr->with_arg) {
		if (state->short_opt_ch[1]) {
			/* `-oarg` form */
			opt_arg = &state->short_opt_ch[1];
		} else {
			/* `-o arg` form */
			opt_arg = next_orig_arg;
			used_next_orig_arg = true;
		}

		/*
			* We accept `-o ''` (empty option's argument),
			* but not `-o` alone if an option's argument is
			* expected.
			*/
		if (!opt_arg || (state->short_opt_ch[1] && strlen(opt_arg) == 0)) {
			argpar_string_append_printf(error,
				"Missing required argument for option `-%c`",
				*state->short_opt_ch);
			used_next_orig_arg = false;
			goto error;
		}
	}

	/* Create and append option argument */
	opt_item = create_opt_item(descr, opt_arg);
	if (!opt_item) {
		goto error;
	}

	*item = &opt_item->base;

	state->short_opt_ch++;

	if (descr->with_arg || !*state->short_opt_ch) {
		/* Option has an argument: no more options */
		state->short_opt_ch = NULL;

		if (used_next_orig_arg) {
			state->i += 2;
		} else {
			state->i += 1;
		}
	}

	goto end;

error:
	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
	}

end:
	return ret;
}

static
enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
		const char * const next_orig_arg,
		const struct argpar_opt_descr * const descrs,
		struct argpar_state *state,
		char **error,
		struct argpar_item **item)
{
	const size_t max_len = 127;
	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
	const struct argpar_opt_descr *descr;
	struct argpar_item_opt *opt_item;
	bool used_next_orig_arg = false;

	/* Option's argument, if any */
	const char *opt_arg = NULL;

	/* Position of first `=`, if any */
	const char *eq_pos;

	/* Buffer holding option name when `long_opt_arg` contains `=` */
	char buf[max_len + 1];

	/* Option name */
	const char *long_opt_name = long_opt_arg;

	if (strlen(long_opt_arg) == 0) {
		argpar_string_append_printf(error,
			"Invalid argument");
		goto error;
	}

	/* Find the first `=` in original argument */
	eq_pos = strchr(long_opt_arg, '=');
	if (eq_pos) {
		const size_t long_opt_name_size = eq_pos - long_opt_arg;

		/* Isolate the option name */
		if (long_opt_name_size > max_len) {
			argpar_string_append_printf(error,
				"Invalid argument `--%s`", long_opt_arg);
			goto error;
		}

		memcpy(buf, long_opt_arg, long_opt_name_size);
		buf[long_opt_name_size] = '\0';
		long_opt_name = buf;
	}

	/* Find corresponding option descriptor */
	descr = find_descr(descrs, '\0', long_opt_name);
	if (!descr) {
		argpar_string_append_printf(error,
			"Unknown option `--%s`", long_opt_name);
		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
		goto error;
	}

	/* Find option's argument if any */
	if (descr->with_arg) {
		if (eq_pos) {
			/* `--long-opt=arg` style */
			opt_arg = eq_pos + 1;
		} else {
			/* `--long-opt arg` style */
			if (!next_orig_arg) {
				argpar_string_append_printf(error,
					"Missing required argument for option `--%s`",
					long_opt_name);
				goto error;
			}

			opt_arg = next_orig_arg;
			used_next_orig_arg = true;
		}
	}

	/* Create and append option argument */
	opt_item = create_opt_item(descr, opt_arg);
	if (!opt_item) {
		goto error;
	}

	if (used_next_orig_arg) {
		state->i += 2;
	} else {
		state->i += 1;
	}

	*item = &opt_item->base;
	goto end;

error:
	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
	}

end:
	return ret;
}

static
enum parse_orig_arg_opt_ret parse_orig_arg_opt(const char * const orig_arg,
		const char * const next_orig_arg,
		const struct argpar_opt_descr * const descrs,
		struct argpar_state *state,
		char **error,
		struct argpar_item **item)
{
	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;

	ARGPAR_ASSERT(orig_arg[0] == '-');

	if (orig_arg[1] == '-') {
		/* Long option */
		ret = parse_long_opt(&orig_arg[2],
			next_orig_arg, descrs, state, error, item);
	} else {
		/* Short option */
		ret = parse_short_opts(&orig_arg[1],
			next_orig_arg, descrs, state, error, item);
	}

	return ret;
}

static
bool prepend_while_parsing_arg_to_error(char **error,
		const unsigned int i, const char * const arg)
{
	char *new_error;
	bool success;

	ARGPAR_ASSERT(error);
	ARGPAR_ASSERT(*error);

	new_error = argpar_asprintf("While parsing argument #%u (`%s`): %s",
		i + 1, arg, *error);
	if (!new_error) {
		success = false;
		goto end;
	}

	free(*error);
	*error = new_error;
	success = true;

end:
	return success;
}

ARGPAR_HIDDEN
struct argpar_state *argpar_state_create(
		unsigned int argc,
		const char * const *argv,
		const struct argpar_opt_descr * const descrs)
{
	struct argpar_state *state;

	state = argpar_zalloc(struct argpar_state);
	if (!state) {
		goto end;
	}

	state->argc = argc;
	state->argv = argv;
	state->descrs = descrs;

end:
	return state;
}

ARGPAR_HIDDEN
void argpar_state_destroy(struct argpar_state *state)
{
	free(state);
}

ARGPAR_HIDDEN
enum argpar_state_parse_next_status argpar_state_parse_next(
		struct argpar_state *state,
		struct argpar_item **item,
		char **error)
{
	enum argpar_state_parse_next_status status;

	ARGPAR_ASSERT(state->i <= state->argc);

	*error = NULL;

	if (state->i == state->argc) {
		status = ARGPAR_STATE_PARSE_NEXT_STATUS_END;
		goto end;
	}

	enum parse_orig_arg_opt_ret parse_orig_arg_opt_ret;
	const char * const orig_arg = state->argv[state->i];
	const char * const next_orig_arg =
		state->i < (state->argc - 1) ? state->argv[state->i + 1] : NULL;

	if (orig_arg[0] != '-') {
		/* Non-option argument */
		struct argpar_item_non_opt *non_opt_item =
			create_non_opt_item(orig_arg, state->i, state->non_opt_index);

		if (!non_opt_item) {
			status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
			goto end;
		}

		state->non_opt_index++;
		state->i++;

		*item = &non_opt_item->base;
		status = ARGPAR_STATE_PARSE_NEXT_STATUS_OK;
		goto end;
	}

	/* Option argument */
	parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
		next_orig_arg, state->descrs, state, error, item);
	switch (parse_orig_arg_opt_ret) {
	case PARSE_ORIG_ARG_OPT_RET_OK:
		status = ARGPAR_STATE_PARSE_NEXT_STATUS_OK;
		break;
	case PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT:
		status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT;
		break;;
	case PARSE_ORIG_ARG_OPT_RET_ERROR:
		prepend_while_parsing_arg_to_error(
			error, state->i, orig_arg);
		status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
		break;
	default:
		abort();
	}

end:
	return status;
}

ARGPAR_HIDDEN
int argpar_state_get_ingested_orig_args(struct argpar_state *state)
{
	return state->i;
}

ARGPAR_HIDDEN
struct argpar_parse_ret argpar_parse(unsigned int argc,
		const char * const *argv,
		const struct argpar_opt_descr * const descrs,
		bool fail_on_unknown_opt)
{
	struct argpar_parse_ret parse_ret = { 0 };
	struct argpar_item *item = NULL;
	struct argpar_state *state = NULL;

	parse_ret.items = new_item_array();
	if (!parse_ret.items) {
		parse_ret.error = strdup("Failed to create items array.");
		ARGPAR_ASSERT(parse_ret.error);
		goto error;
	}

	state = argpar_state_create(argc, argv, descrs);
	if (!state) {
		parse_ret.error = strdup("Failed to create argpar state.");
		ARGPAR_ASSERT(parse_ret.error);
		goto error;
	}

	while (true) {
		enum argpar_state_parse_next_status status;

		status = argpar_state_parse_next(state, &item, &parse_ret.error);
		if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR) {
			goto error;
		} else if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_END) {
			break;
		} else if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT) {
			if (fail_on_unknown_opt) {
				parse_ret.ingested_orig_args =
					argpar_state_get_ingested_orig_args(state);
				prepend_while_parsing_arg_to_error(
					&parse_ret.error, parse_ret.ingested_orig_args,
					argv[parse_ret.ingested_orig_args]);
				status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
				goto error;
			}

			free(parse_ret.error);
			parse_ret.error = NULL;
			break;
		}

		ARGPAR_ASSERT(status == ARGPAR_STATE_PARSE_NEXT_STATUS_OK);

		if (!push_item(parse_ret.items, item)) {
			goto error;
		}
		item = NULL;
	}

	ARGPAR_ASSERT(!parse_ret.error);
	parse_ret.ingested_orig_args =
		argpar_state_get_ingested_orig_args(state);
	goto end;

error:
	ARGPAR_ASSERT(parse_ret.error);

	/* That's how we indicate that an error occurred */
	destroy_item_array(parse_ret.items);
	parse_ret.items = NULL;

end:
	argpar_state_destroy(state);
	argpar_item_destroy(item);
	return parse_ret;
}

ARGPAR_HIDDEN
void argpar_parse_ret_fini(struct argpar_parse_ret *ret)
{
	ARGPAR_ASSERT(ret);

	destroy_item_array(ret->items);
	ret->items = NULL;

	free(ret->error);
	ret->error = NULL;
}
Commit	Line	Data
e2fb96d8 SM	1	/*
	2	* SPDX-License-Identifier: MIT
	3	*
	4	* Copyright 2019 Philippe Proulx <pproulx@efficios.com>
	5	*/
	6
	7	#include <assert.h>
	8	#include <stdarg.h>
	9	#include <stdbool.h>
	10	#include <stdio.h>
	11	#include <stdlib.h>
	12	#include <string.h>
	13
	14	#include "argpar.h"
	15
	16	#define argpar_realloc(_ptr, _type, _nmemb) ((_type ) realloc(_ptr, (_nmemb) sizeof(_type)))
	17	#define argpar_calloc(_type, _nmemb) ((_type *) calloc((_nmemb), sizeof(_type)))
	18	#define argpar_zalloc(_type) argpar_calloc(_type, 1)
	19
	20	#define ARGPAR_ASSERT(_cond) assert(_cond)
	21
	22	#ifdef __MINGW_PRINTF_FORMAT
	23	# define ARGPAR_PRINTF_FORMAT __MINGW_PRINTF_FORMAT
	24	#else
	25	# define ARGPAR_PRINTF_FORMAT printf
	26	#endif
	27
4624dad0 SM	28	/*
	29	* Structure holding the argpar state between successive argpar_state_parse_next
	30	* calls.
	31	*
	32	* Created with `argpar_state_create` and destroyed with `argpar_state_destroy`.
	33	*/
	34	struct argpar_state {
	35	/*
	36	* Data provided by the user in argpar_state_create, does not change
	37	* afterwards.
	38	*/
	39	unsigned int argc;
	40	const char * const *argv;
	41	const struct argpar_opt_descr *descrs;
	42
	43	/*
	44	* Index of the argument to process in the next argpar_state_parse_next
	45	* call.
	46	*/
	47	unsigned int i;
	48
	49	/* Counter of non-option arguments. */
	50	int non_opt_index;
	51
	52	/*
	53	* Short option state: if set, we are in the middle of a short option
	54	* group, so we should resume there at the next argpar_state_parse_next
	55	* call.
	56	*/
	57	const char *short_opt_ch;
	58	};
	59
e2fb96d8 SM	60	static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 0)))
	61	char argpar_vasprintf(const char fmt, va_list args)
	62	{
	63	int len1, len2;
	64	char *str;
	65	va_list args2;
	66
	67	va_copy(args2, args);
	68
	69	len1 = vsnprintf(NULL, 0, fmt, args);
	70	if (len1 < 0) {
	71	str = NULL;
	72	goto end;
	73	}
	74
	75	str = malloc(len1 + 1);
	76	if (!str) {
	77	goto end;
	78	}
	79
	80	len2 = vsnprintf(str, len1 + 1, fmt, args2);
	81
	82	ARGPAR_ASSERT(len1 == len2);
	83
	84	end:
	85	va_end(args2);
	86	return str;
	87	}
	88
	89
	90	static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 2)))
	91	char argpar_asprintf(const char fmt, ...)
	92	{
	93	va_list args;
	94	char *str;
	95
	96	va_start(args, fmt);
	97	str = argpar_vasprintf(fmt, args);
	98	va_end(args);
	99
	100	return str;
	101	}
	102
	103	static __attribute__((format(ARGPAR_PRINTF_FORMAT, 2, 3)))
	104	bool argpar_string_append_printf(char *str, const char fmt, ...)
	105	{
	106	char *new_str = NULL;
	107	char *addendum;
	108	bool success;
	109	va_list args;
	110
	111	ARGPAR_ASSERT(str);
	112
	113	va_start(args, fmt);
	114	addendum = argpar_vasprintf(fmt, args);
	115	va_end(args);
	116
	117	if (!addendum) {
	118	success = false;
	119	goto end;
	120	}
	121
	122	new_str = argpar_asprintf("%s%s", str ? str : "", addendum);
	123	if (!new_str) {
124	success = false;
125	goto end;
126	}
127
128	free(*str);
129	*str = new_str;
130
131	success = true;
132
133	end:
134	free(addendum);
135
136	return success;
137	}
138
4624dad0 SM	139	ARGPAR_HIDDEN
4624dad0 SM	140	void argpar_item_destroy(struct argpar_item *item)
e2fb96d8 SM	141	{
	142	if (!item) {
	143	goto end;
	144	}
	145
	146	if (item->type == ARGPAR_ITEM_TYPE_OPT) {
	147	struct argpar_item_opt * const opt_item = (void *) item;
	148
	149	free((void *) opt_item->arg);
	150	}
	151
	152	free(item);
	153
	154	end:
	155	return;
	156	}
	157
	158	static
	159	bool push_item(struct argpar_item_array * const array,
	160	struct argpar_item * const item)
	161	{
	162	bool success;
	163
	164	ARGPAR_ASSERT(array);
	165	ARGPAR_ASSERT(item);
	166
	167	if (array->n_items == array->n_alloc) {
	168	unsigned int new_n_alloc = array->n_alloc * 2;
	169	struct argpar_item **new_items;
	170
	171	new_items = argpar_realloc(array->items,
	172	struct argpar_item *, new_n_alloc);
	173	if (!new_items) {
	174	success = false;
	175	goto end;
	176	}
	177
	178	array->n_alloc = new_n_alloc;
	179	array->items = new_items;
	180	}
	181
	182	array->items[array->n_items] = item;
	183	array->n_items++;
	184
	185	success = true;
	186
	187	end:
	188	return success;
	189	}
	190
	191	static
	192	void destroy_item_array(struct argpar_item_array * const array)
	193	{
	194	if (array) {
	195	unsigned int i;
	196
	197	for (i = 0; i < array->n_items; i++) {
4624dad0	198	argpar_item_destroy(array->items[i]);
e2fb96d8 SM	199	}
	200
	201	free(array->items);
	202	free(array);
	203	}
	204	}
	205
	206	static
	207	struct argpar_item_array *new_item_array(void)
	208	{
	209	struct argpar_item_array *ret;
	210	const int initial_size = 10;
	211
	212	ret = argpar_zalloc(struct argpar_item_array);
	213	if (!ret) {
	214	goto end;
	215	}
	216
	217	ret->items = argpar_calloc(struct argpar_item *, initial_size);
	218	if (!ret->items) {
	219	goto error;
	220	}
	221
	222	ret->n_alloc = initial_size;
	223
	224	goto end;
	225
	226	error:
	227	destroy_item_array(ret);
	228	ret = NULL;
	229
	230	end:
	231	return ret;
	232	}
	233
	234	static
	235	struct argpar_item_opt *create_opt_item(
	236	const struct argpar_opt_descr * const descr,
	237	const char * const arg)
	238	{
	239	struct argpar_item_opt *opt_item =
	240	argpar_zalloc(struct argpar_item_opt);
	241
	242	if (!opt_item) {
	243	goto end;
	244	}
	245
	246	opt_item->base.type = ARGPAR_ITEM_TYPE_OPT;
	247	opt_item->descr = descr;
	248
	249	if (arg) {
	250	opt_item->arg = strdup(arg);
	251	if (!opt_item->arg) {
	252	goto error;
	253	}
	254	}
	255
	256	goto end;
	257
	258	error:
4624dad0	259	argpar_item_destroy(&opt_item->base);
e2fb96d8 SM	260	opt_item = NULL;
	261
	262	end:
	263	return opt_item;
	264	}
	265
	266	static
	267	struct argpar_item_non_opt create_non_opt_item(const char const arg,
	268	const unsigned int orig_index,
	269	const unsigned int non_opt_index)
	270	{
	271	struct argpar_item_non_opt * const non_opt_item =
	272	argpar_zalloc(struct argpar_item_non_opt);
	273
	274	if (!non_opt_item) {
	275	goto end;
	276	}
	277
	278	non_opt_item->base.type = ARGPAR_ITEM_TYPE_NON_OPT;
	279	non_opt_item->arg = arg;
	280	non_opt_item->orig_index = orig_index;
	281	non_opt_item->non_opt_index = non_opt_index;
	282
	283	end:
	284	return non_opt_item;
	285	}
	286
	287	static
	288	const struct argpar_opt_descr *find_descr(
	289	const struct argpar_opt_descr * const descrs,
	290	const char short_name, const char * const long_name)
	291	{
	292	const struct argpar_opt_descr *descr;
	293
	294	for (descr = descrs; descr->short_name \|\| descr->long_name; descr++) {
	295	if (short_name && descr->short_name &&
	296	short_name == descr->short_name) {
	297	goto end;
	298	}
	299
	300	if (long_name && descr->long_name &&
	301	strcmp(long_name, descr->long_name) == 0) {
	302	goto end;
	303	}
	304	}
	305
	306	end:
	307	return !descr->short_name && !descr->long_name ? NULL : descr;
	308	}
	309
	310	enum parse_orig_arg_opt_ret {
	311	PARSE_ORIG_ARG_OPT_RET_OK,
	312	PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT = -2,
	313	PARSE_ORIG_ARG_OPT_RET_ERROR = -1,
	314	};
	315
	316	static
	317	enum parse_orig_arg_opt_ret parse_short_opts(const char * const short_opts,
	318	const char * const next_orig_arg,
	319	const struct argpar_opt_descr * const descrs,
4624dad0 SM	320	struct argpar_state *state,
	321	char **error,
	322	struct argpar_item **item)
e2fb96d8 SM	323	{
e2fb96d8 SM	324	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
4624dad0	325	bool used_next_orig_arg = false;
e2fb96d8 SM	326
e2fb96d8 SM	327	if (strlen(short_opts) == 0) {
4624dad0	328	argpar_string_append_printf(error, "Invalid argument");
e2fb96d8 SM	329	goto error;
	330	}
	331
4624dad0 SM	332	if (!state->short_opt_ch) {
	333	state->short_opt_ch = short_opts;
	334	}
e2fb96d8	335
4624dad0 SM	336	const char *opt_arg = NULL;
	337	const struct argpar_opt_descr *descr;
	338	struct argpar_item_opt *opt_item;
e2fb96d8	339
4624dad0 SM	340	/* Find corresponding option descriptor */
	341	descr = find_descr(descrs, *state->short_opt_ch, NULL);
	342	if (!descr) {
	343	ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
	344	argpar_string_append_printf(error,
	345	"Unknown option `-%c`", *state->short_opt_ch);
	346	goto error;
	347	}
e2fb96d8	348
4624dad0 SM	349	if (descr->with_arg) {
	350	if (state->short_opt_ch[1]) {
	351	/* `-oarg` form */
	352	opt_arg = &state->short_opt_ch[1];
	353	} else {
	354	/* `-o arg` form */
	355	opt_arg = next_orig_arg;
	356	used_next_orig_arg = true;
e2fb96d8 SM	357	}
e2fb96d8 SM	358
4624dad0 SM	359	/*
	360	* We accept `-o ''` (empty option's argument),
	361	* but not `-o` alone if an option's argument is
	362	* expected.
	363	*/
	364	if (!opt_arg \|\| (state->short_opt_ch[1] && strlen(opt_arg) == 0)) {
	365	argpar_string_append_printf(error,
	366	"Missing required argument for option `-%c`",
	367	*state->short_opt_ch);
	368	used_next_orig_arg = false;
e2fb96d8 SM	369	goto error;
e2fb96d8 SM	370	}
4624dad0	371	}
e2fb96d8	372
4624dad0 SM	373	/* Create and append option argument */
	374	opt_item = create_opt_item(descr, opt_arg);
	375	if (!opt_item) {
	376	goto error;
	377	}
e2fb96d8	378
4624dad0	379	*item = &opt_item->base;
e2fb96d8	380
4624dad0 SM	381	state->short_opt_ch++;
	382
	383	if (descr->with_arg \|\| !*state->short_opt_ch) {
	384	/* Option has an argument: no more options */
	385	state->short_opt_ch = NULL;
	386
	387	if (used_next_orig_arg) {
	388	state->i += 2;
	389	} else {
	390	state->i += 1;
	391	}
e2fb96d8 SM	392	}
	393
	394	goto end;
	395
	396	error:
	397	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
	398	ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
	399	}
	400
	401	end:
	402	return ret;
	403	}
	404
	405	static
	406	enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
	407	const char * const next_orig_arg,
	408	const struct argpar_opt_descr * const descrs,
4624dad0 SM	409	struct argpar_state *state,
	410	char **error,
	411	struct argpar_item **item)
e2fb96d8 SM	412	{
	413	const size_t max_len = 127;
	414	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
	415	const struct argpar_opt_descr *descr;
	416	struct argpar_item_opt *opt_item;
4624dad0	417	bool used_next_orig_arg = false;
e2fb96d8 SM	418
	419	/* Option's argument, if any */
	420	const char *opt_arg = NULL;
	421
	422	/* Position of first `=`, if any */
	423	const char *eq_pos;
	424
	425	/* Buffer holding option name when `long_opt_arg` contains `=` */
	426	char buf[max_len + 1];
	427
	428	/* Option name */
	429	const char *long_opt_name = long_opt_arg;
	430
	431	if (strlen(long_opt_arg) == 0) {
4624dad0	432	argpar_string_append_printf(error,
e2fb96d8 SM	433	"Invalid argument");
	434	goto error;
	435	}
	436
	437	/* Find the first `=` in original argument */
	438	eq_pos = strchr(long_opt_arg, '=');
	439	if (eq_pos) {
	440	const size_t long_opt_name_size = eq_pos - long_opt_arg;
	441
	442	/* Isolate the option name */
	443	if (long_opt_name_size > max_len) {
4624dad0	444	argpar_string_append_printf(error,
e2fb96d8 SM	445	"Invalid argument `--%s`", long_opt_arg);
	446	goto error;
	447	}
	448
	449	memcpy(buf, long_opt_arg, long_opt_name_size);
	450	buf[long_opt_name_size] = '\0';
	451	long_opt_name = buf;
	452	}
	453
	454	/* Find corresponding option descriptor */
	455	descr = find_descr(descrs, '\0', long_opt_name);
	456	if (!descr) {
4624dad0	457	argpar_string_append_printf(error,
e2fb96d8 SM	458	"Unknown option `--%s`", long_opt_name);
	459	ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
	460	goto error;
	461	}
	462
	463	/* Find option's argument if any */
	464	if (descr->with_arg) {
	465	if (eq_pos) {
	466	/* `--long-opt=arg` style */
	467	opt_arg = eq_pos + 1;
	468	} else {
	469	/* `--long-opt arg` style */
	470	if (!next_orig_arg) {
4624dad0	471	argpar_string_append_printf(error,
e2fb96d8 SM	472	"Missing required argument for option `--%s`",
	473	long_opt_name);
	474	goto error;
	475	}
	476
	477	opt_arg = next_orig_arg;
4624dad0	478	used_next_orig_arg = true;
e2fb96d8 SM	479	}
	480	}
	481
	482	/* Create and append option argument */
	483	opt_item = create_opt_item(descr, opt_arg);
	484	if (!opt_item) {
	485	goto error;
	486	}
	487
4624dad0 SM	488	if (used_next_orig_arg) {
	489	state->i += 2;
	490	} else {
	491	state->i += 1;
e2fb96d8 SM	492	}
e2fb96d8 SM	493
4624dad0	494	*item = &opt_item->base;
e2fb96d8 SM	495	goto end;
	496
	497	error:
	498	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
	499	ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
	500	}
	501
	502	end:
	503	return ret;
	504	}
	505
	506	static
	507	enum parse_orig_arg_opt_ret parse_orig_arg_opt(const char * const orig_arg,
	508	const char * const next_orig_arg,
	509	const struct argpar_opt_descr * const descrs,
4624dad0 SM	510	struct argpar_state *state,
	511	char **error,
	512	struct argpar_item **item)
e2fb96d8 SM	513	{
	514	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
	515
	516	ARGPAR_ASSERT(orig_arg[0] == '-');
	517
	518	if (orig_arg[1] == '-') {
	519	/* Long option */
	520	ret = parse_long_opt(&orig_arg[2],
4624dad0	521	next_orig_arg, descrs, state, error, item);
e2fb96d8 SM	522	} else {
	523	/* Short option */
	524	ret = parse_short_opts(&orig_arg[1],
4624dad0	525	next_orig_arg, descrs, state, error, item);
e2fb96d8 SM	526	}
	527
	528	return ret;
	529	}
	530
	531	static
	532	bool prepend_while_parsing_arg_to_error(char **error,
	533	const unsigned int i, const char * const arg)
	534	{
	535	char *new_error;
	536	bool success;
	537
	538	ARGPAR_ASSERT(error);
	539	ARGPAR_ASSERT(*error);
	540
	541	new_error = argpar_asprintf("While parsing argument #%u (`%s`): %s",
	542	i + 1, arg, *error);
	543	if (!new_error) {
	544	success = false;
	545	goto end;
	546	}
	547
	548	free(*error);
	549	*error = new_error;
	550	success = true;
	551
	552	end:
	553	return success;
	554	}
	555
4624dad0 SM	556	ARGPAR_HIDDEN
	557	struct argpar_state *argpar_state_create(
	558	unsigned int argc,
	559	const char * const *argv,
	560	const struct argpar_opt_descr * const descrs)
	561	{
	562	struct argpar_state *state;
	563
	564	state = argpar_zalloc(struct argpar_state);
	565	if (!state) {
	566	goto end;
	567	}
	568
	569	state->argc = argc;
	570	state->argv = argv;
	571	state->descrs = descrs;
	572
	573	end:
	574	return state;
	575	}
	576
	577	ARGPAR_HIDDEN
	578	void argpar_state_destroy(struct argpar_state *state)
	579	{
	580	free(state);
	581	}
	582
	583	ARGPAR_HIDDEN
	584	enum argpar_state_parse_next_status argpar_state_parse_next(
	585	struct argpar_state *state,
	586	struct argpar_item **item,
	587	char **error)
	588	{
	589	enum argpar_state_parse_next_status status;
	590
	591	ARGPAR_ASSERT(state->i <= state->argc);
	592
	593	*error = NULL;
	594
	595	if (state->i == state->argc) {
	596	status = ARGPAR_STATE_PARSE_NEXT_STATUS_END;
	597	goto end;
	598	}
	599
	600	enum parse_orig_arg_opt_ret parse_orig_arg_opt_ret;
	601	const char * const orig_arg = state->argv[state->i];
	602	const char * const next_orig_arg =
	603	state->i < (state->argc - 1) ? state->argv[state->i + 1] : NULL;
	604
	605	if (orig_arg[0] != '-') {
	606	/* Non-option argument */
	607	struct argpar_item_non_opt *non_opt_item =
	608	create_non_opt_item(orig_arg, state->i, state->non_opt_index);
	609
	610	if (!non_opt_item) {
	611	status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
	612	goto end;
	613	}
	614
	615	state->non_opt_index++;
	616	state->i++;
	617
	618	*item = &non_opt_item->base;
	619	status = ARGPAR_STATE_PARSE_NEXT_STATUS_OK;
620	goto end;
621	}
622
623	/* Option argument */
624	parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
625	next_orig_arg, state->descrs, state, error, item);
626	switch (parse_orig_arg_opt_ret) {
627	case PARSE_ORIG_ARG_OPT_RET_OK:
628	status = ARGPAR_STATE_PARSE_NEXT_STATUS_OK;
629	break;
630	case PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT:
631	status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT;
632	break;;
633	case PARSE_ORIG_ARG_OPT_RET_ERROR:
634	prepend_while_parsing_arg_to_error(
635	error, state->i, orig_arg);
636	status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
637	break;
638	default:
639	abort();
640	}
641
642	end:
643	return status;
644	}
645
646	ARGPAR_HIDDEN
647	int argpar_state_get_ingested_orig_args(struct argpar_state *state)
648	{
649	return state->i;
650	}
651
e2fb96d8 SM	652	ARGPAR_HIDDEN
	653	struct argpar_parse_ret argpar_parse(unsigned int argc,
	654	const char * const *argv,
	655	const struct argpar_opt_descr * const descrs,
	656	bool fail_on_unknown_opt)
	657	{
	658	struct argpar_parse_ret parse_ret = { 0 };
4624dad0 SM	659	struct argpar_item *item = NULL;
4624dad0 SM	660	struct argpar_state *state = NULL;
e2fb96d8 SM	661
	662	parse_ret.items = new_item_array();
	663	if (!parse_ret.items) {
4624dad0 SM	664	parse_ret.error = strdup("Failed to create items array.");
4624dad0 SM	665	ARGPAR_ASSERT(parse_ret.error);
e2fb96d8 SM	666	goto error;
	667	}
	668
4624dad0 SM	669	state = argpar_state_create(argc, argv, descrs);
	670	if (!state) {
	671	parse_ret.error = strdup("Failed to create argpar state.");
	672	ARGPAR_ASSERT(parse_ret.error);
	673	goto error;
	674	}
e2fb96d8	675
4624dad0 SM	676	while (true) {
4624dad0 SM	677	enum argpar_state_parse_next_status status;
e2fb96d8	678
4624dad0 SM	679	status = argpar_state_parse_next(state, &item, &parse_ret.error);
	680	if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR) {
	681	goto error;
	682	} else if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_END) {
e2fb96d8	683	break;
4624dad0	684	} else if (status == ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT) {
e2fb96d8	685	if (fail_on_unknown_opt) {
4624dad0 SM	686	parse_ret.ingested_orig_args =
4624dad0 SM	687	argpar_state_get_ingested_orig_args(state);
e2fb96d8	688	prepend_while_parsing_arg_to_error(
4624dad0 SM	689	&parse_ret.error, parse_ret.ingested_orig_args,
	690	argv[parse_ret.ingested_orig_args]);
	691	status = ARGPAR_STATE_PARSE_NEXT_STATUS_ERROR;
e2fb96d8 SM	692	goto error;
	693	}
	694
e2fb96d8 SM	695	free(parse_ret.error);
e2fb96d8 SM	696	parse_ret.error = NULL;
4624dad0	697	break;
e2fb96d8 SM	698	}
e2fb96d8 SM	699
4624dad0 SM	700	ARGPAR_ASSERT(status == ARGPAR_STATE_PARSE_NEXT_STATUS_OK);
	701
	702	if (!push_item(parse_ret.items, item)) {
	703	goto error;
e2fb96d8	704	}
4624dad0	705	item = NULL;
e2fb96d8 SM	706	}
e2fb96d8 SM	707
4624dad0 SM	708	ARGPAR_ASSERT(!parse_ret.error);
	709	parse_ret.ingested_orig_args =
	710	argpar_state_get_ingested_orig_args(state);
e2fb96d8 SM	711	goto end;
	712
	713	error:
4624dad0 SM	714	ARGPAR_ASSERT(parse_ret.error);
4624dad0 SM	715
e2fb96d8 SM	716	/* That's how we indicate that an error occurred */
	717	destroy_item_array(parse_ret.items);
	718	parse_ret.items = NULL;
	719
	720	end:
4624dad0 SM	721	argpar_state_destroy(state);
4624dad0 SM	722	argpar_item_destroy(item);
e2fb96d8 SM	723	return parse_ret;
	724	}
	725
	726	ARGPAR_HIDDEN
	727	void argpar_parse_ret_fini(struct argpar_parse_ret *ret)
	728	{
	729	ARGPAR_ASSERT(ret);
	730
	731	destroy_item_array(ret->items);
	732	ret->items = NULL;
	733
	734	free(ret->error);
	735	ret->error = NULL;
	736	}