1/*
2 * *****************************************************************************
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (c) 2018-2023 Gavin D. Howard and contributors.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * * Redistributions of source code must retain the above copyright notice, this
12 *   list of conditions and the following disclaimer.
13 *
14 * * Redistributions in binary form must reproduce the above copyright notice,
15 *   this list of conditions and the following disclaimer in the documentation
16 *   and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 *
30 * *****************************************************************************
31 *
32 * Adapted from https://github.com/skeeto/optparse
33 *
34 * *****************************************************************************
35 *
36 * Code for getopt_long() replacement. It turns out that getopt_long() has
37 * different behavior on different platforms.
38 *
39 */
40
41#include <assert.h>
42#include <stdbool.h>
43#include <stdlib.h>
44#include <string.h>
45
46#include <status.h>
47#include <opt.h>
48#include <vm.h>
49
50/**
51 * Returns true if index @a i is the end of the longopts array.
52 * @param longopts  The long options array.
53 * @param i         The index to test.
54 * @return          True if @a i is the last index, false otherwise.
55 */
56static inline bool
57bc_opt_longoptsEnd(const BcOptLong* longopts, size_t i)
58{
59	return !longopts[i].name && !longopts[i].val;
60}
61
62/**
63 * Returns the name of the long option that matches the character @a c.
64 * @param longopts  The long options array.
65 * @param c         The character to match against.
66 * @return          The name of the long option that matches @a c, or "NULL".
67 */
68static const char*
69bc_opt_longopt(const BcOptLong* longopts, int c)
70{
71	size_t i;
72
73	for (i = 0; !bc_opt_longoptsEnd(longopts, i); ++i)
74	{
75		if (longopts[i].val == c) return longopts[i].name;
76	}
77
78	BC_UNREACHABLE
79
80#if !BC_CLANG
81	return "NULL";
82#endif // !BC_CLANG
83}
84
85/**
86 * Issues a fatal error for an option parsing failure.
87 * @param err        The error.
88 * @param c          The character for the failing option.
89 * @param str        Either the string for the failing option, or the invalid
90 *                   option.
91 * @param use_short  True if the short option should be used for error printing,
92 *                   false otherwise.
93 */
94static void
95bc_opt_error(BcErr err, int c, const char* str, bool use_short)
96{
97	if (err == BC_ERR_FATAL_OPTION)
98	{
99		if (use_short)
100		{
101			char short_str[2];
102
103			short_str[0] = (char) c;
104			short_str[1] = '\0';
105
106			bc_error(err, 0, short_str);
107		}
108		else bc_error(err, 0, str);
109	}
110	else bc_error(err, 0, (int) c, str);
111}
112
113/**
114 * Returns the type of the long option that matches @a c.
115 * @param longopts  The long options array.
116 * @param c         The character to match against.
117 * @return          The type of the long option as an integer, or -1 if none.
118 */
119static int
120bc_opt_type(const BcOptLong* longopts, char c)
121{
122	size_t i;
123
124	if (c == ':') return -1;
125
126	for (i = 0; !bc_opt_longoptsEnd(longopts, i) && longopts[i].val != c; ++i)
127	{
128		continue;
129	}
130
131	if (bc_opt_longoptsEnd(longopts, i)) return -1;
132
133	return (int) longopts[i].type;
134}
135
136/**
137 * Parses a short option.
138 * @param o         The option parser.
139 * @param longopts  The long options array.
140 * @return          The character for the short option, or -1 if none left.
141 */
142static int
143bc_opt_parseShort(BcOpt* o, const BcOptLong* longopts)
144{
145	int type;
146	char* next;
147	char* option = o->argv[o->optind];
148	int ret = -1;
149
150	// Make sure to clear these.
151	o->optopt = 0;
152	o->optarg = NULL;
153
154	// Get the next option.
155	option += o->subopt + 1;
156	o->optopt = option[0];
157
158	// Get the type and the next data.
159	type = bc_opt_type(longopts, option[0]);
160	next = o->argv[o->optind + 1];
161
162	switch (type)
163	{
164		case -1:
165		case BC_OPT_BC_ONLY:
166		case BC_OPT_DC_ONLY:
167		{
168			// Check for invalid option and barf if so.
169			if (type == -1 || (type == BC_OPT_BC_ONLY && BC_IS_DC) ||
170			    (type == BC_OPT_DC_ONLY && BC_IS_BC))
171			{
172				char str[2] = { 0, 0 };
173
174				str[0] = option[0];
175				o->optind += 1;
176
177				bc_opt_error(BC_ERR_FATAL_OPTION, option[0], str, true);
178			}
179
180			// Fallthrough.
181			BC_FALLTHROUGH
182		}
183
184		case BC_OPT_NONE:
185		{
186			// If there is something else, update the suboption.
187			if (option[1]) o->subopt += 1;
188			else
189			{
190				// Go to the next argument.
191				o->subopt = 0;
192				o->optind += 1;
193			}
194
195			ret = (int) option[0];
196
197			break;
198		}
199
200		case BC_OPT_REQUIRED_BC_ONLY:
201		{
202#if DC_ENABLED
203			if (BC_IS_DC)
204			{
205				bc_opt_error(BC_ERR_FATAL_OPTION, option[0],
206				             bc_opt_longopt(longopts, option[0]), true);
207			}
208#endif // DC_ENABLED
209
210			// Fallthrough
211			BC_FALLTHROUGH
212		}
213
214		case BC_OPT_REQUIRED:
215		{
216			// Always go to the next argument.
217			o->subopt = 0;
218			o->optind += 1;
219
220			// Use the next characters, if they exist.
221			if (option[1]) o->optarg = option + 1;
222			else if (next != NULL)
223			{
224				// USe the next.
225				o->optarg = next;
226				o->optind += 1;
227			}
228			// No argument, barf.
229			else
230			{
231				bc_opt_error(BC_ERR_FATAL_OPTION_NO_ARG, option[0],
232				             bc_opt_longopt(longopts, option[0]), true);
233			}
234
235			ret = (int) option[0];
236
237			break;
238		}
239	}
240
241	return ret;
242}
243
244/**
245 * Ensures that a long option argument matches a long option name, regardless of
246 * "=<data>" at the end.
247 * @param name    The name to match.
248 * @param option  The command-line argument.
249 * @return        True if @a option matches @a name, false otherwise.
250 */
251static bool
252bc_opt_longoptsMatch(const char* name, const char* option)
253{
254	const char* a = option;
255	const char* n = name;
256
257	// Can never match a NULL name.
258	if (name == NULL) return false;
259
260	// Loop through.
261	for (; *a && *n && *a != '='; ++a, ++n)
262	{
263		if (*a != *n) return false;
264	}
265
266	// Ensure they both end at the same place.
267	return (*n == '\0' && (*a == '\0' || *a == '='));
268}
269
270/**
271 * Returns a pointer to the argument of a long option, or NULL if it not in the
272 * same argument.
273 * @param option  The option to find the argument of.
274 * @return        A pointer to the argument of the option, or NULL if none.
275 */
276static char*
277bc_opt_longoptsArg(char* option)
278{
279	// Find the end or equals sign.
280	for (; *option && *option != '='; ++option)
281	{
282		continue;
283	}
284
285	if (*option == '=') return option + 1;
286	else return NULL;
287}
288
289int
290bc_opt_parse(BcOpt* o, const BcOptLong* longopts)
291{
292	size_t i;
293	char* option;
294	bool empty;
295
296	// This just eats empty options.
297	do
298	{
299		option = o->argv[o->optind];
300		if (option == NULL) return -1;
301
302		empty = !strcmp(option, "");
303		o->optind += empty;
304	}
305	while (empty);
306
307	// If the option is just a "--".
308	if (BC_OPT_ISDASHDASH(option))
309	{
310		// Consume "--".
311		o->optind += 1;
312		return -1;
313	}
314	// Parse a short option.
315	else if (BC_OPT_ISSHORTOPT(option)) return bc_opt_parseShort(o, longopts);
316	// If the option is not long at this point, we are done.
317	else if (!BC_OPT_ISLONGOPT(option)) return -1;
318
319	// Clear these.
320	o->optopt = 0;
321	o->optarg = NULL;
322
323	// Skip "--" at beginning of the option.
324	option += 2;
325	o->optind += 1;
326
327	// Loop through the valid long options.
328	for (i = 0; !bc_opt_longoptsEnd(longopts, i); i++)
329	{
330		const char* name = longopts[i].name;
331
332		// If we have a match...
333		if (bc_opt_longoptsMatch(name, option))
334		{
335			char* arg;
336
337			// Get the option char and the argument.
338			o->optopt = longopts[i].val;
339			arg = bc_opt_longoptsArg(option);
340
341			// Error if the option is invalid..
342			if ((longopts[i].type == BC_OPT_BC_ONLY && BC_IS_DC) ||
343			    (longopts[i].type == BC_OPT_REQUIRED_BC_ONLY && BC_IS_DC) ||
344			    (longopts[i].type == BC_OPT_DC_ONLY && BC_IS_BC))
345			{
346				bc_opt_error(BC_ERR_FATAL_OPTION, o->optopt, name, false);
347			}
348
349			// Error if we have an argument and should not.
350			if (longopts[i].type == BC_OPT_NONE && arg != NULL)
351			{
352				bc_opt_error(BC_ERR_FATAL_OPTION_ARG, o->optopt, name, false);
353			}
354
355			// Set the argument, or check the next argument if we don't have
356			// one.
357			if (arg != NULL) o->optarg = arg;
358			else if (longopts[i].type == BC_OPT_REQUIRED ||
359			         longopts[i].type == BC_OPT_REQUIRED_BC_ONLY)
360			{
361				// Get the next argument.
362				o->optarg = o->argv[o->optind];
363
364				// All's good if it exists; otherwise, barf.
365				if (o->optarg != NULL) o->optind += 1;
366				else
367				{
368					bc_opt_error(BC_ERR_FATAL_OPTION_NO_ARG, o->optopt, name,
369					             false);
370				}
371			}
372
373			return o->optopt;
374		}
375	}
376
377	// If we reach this point, the option is invalid.
378	bc_opt_error(BC_ERR_FATAL_OPTION, 0, option, false);
379
380	BC_UNREACHABLE
381
382#if !BC_CLANG
383	return -1;
384#endif // !BC_CLANG
385}
386
387void
388bc_opt_init(BcOpt* o, char* argv[])
389{
390	o->argv = argv;
391	o->optind = 1;
392	o->subopt = 0;
393	o->optarg = NULL;
394}
395