xref: /freebsd/contrib/bc/src/opt.c (revision 12e0d316644a4f80f5f1f78cf07bd93def43b1ca)
1 /*
2  * *****************************************************************************
3  *
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 2018-2024 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  */
56 static inline bool
bc_opt_longoptsEnd(const BcOptLong * longopts,size_t i)57 bc_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  */
68 static const char*
bc_opt_longopt(const BcOptLong * longopts,int c)69 bc_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  */
94 static void
bc_opt_error(BcErr err,int c,const char * str,bool use_short)95 bc_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  */
119 static int
bc_opt_type(const BcOptLong * longopts,char c)120 bc_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  */
142 static int
bc_opt_parseShort(BcOpt * o,const BcOptLong * longopts)143 bc_opt_parseShort(BcOpt* o, const BcOptLong* longopts)
144 {
145 	int type;
146 	const char* next;
147 	const 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  */
251 static bool
bc_opt_longoptsMatch(const char * name,const char * option)252 bc_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  */
276 static const char*
bc_opt_longoptsArg(const char * option)277 bc_opt_longoptsArg(const 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 
289 int
bc_opt_parse(BcOpt * o,const BcOptLong * longopts)290 bc_opt_parse(BcOpt* o, const BcOptLong* longopts)
291 {
292 	size_t i;
293 	const 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 			const 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 
387 void
bc_opt_init(BcOpt * o,const char * argv[])388 bc_opt_init(BcOpt* o, const char* argv[])
389 {
390 	o->argv = argv;
391 	o->optind = 1;
392 	o->subopt = 0;
393 	o->optarg = NULL;
394 }
395