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903a5b8a | 1 | /* |
03e1579f | 2 | * SPDX-License-Identifier: MIT |
903a5b8a | 3 | * |
fc07e526 SM |
4 | * Copyright (c) 2019-2021 Philippe Proulx <pproulx@efficios.com> |
5 | * Copyright (c) 2020-2021 Simon Marchi <simon.marchi@efficios.com> | |
903a5b8a SM |
6 | */ |
7 | ||
03e1579f SM |
8 | #ifndef BABELTRACE_ARGPAR_H |
9 | #define BABELTRACE_ARGPAR_H | |
10 | ||
903a5b8a SM |
11 | #include <stdbool.h> |
12 | ||
fc07e526 SM |
13 | /* |
14 | * argpar is a library which provides facilities for command-line | |
15 | * argument parsing. | |
16 | * | |
17 | * Two APIs are available: | |
18 | * | |
19 | * Iterator API: | |
20 | * Create a parsing iterator with argpar_iter_create(), then | |
21 | * repeatedly call argpar_iter_parse_next() to access the parsing | |
22 | * results, until one of: | |
23 | * | |
24 | * * There are no more arguments. | |
25 | * | |
26 | * * The argument parser encounters an error (for example, an | |
27 | * unknown option). | |
28 | * | |
29 | * * You need to stop. | |
30 | * | |
31 | * This API provides more parsing control than the next one. | |
32 | * | |
33 | * Single call API: | |
34 | * Call argpar_parse(), which parses the arguments until one of: | |
35 | * | |
36 | * * There are no more arguments. | |
37 | * | |
38 | * * It encounters an argument parsing error. | |
39 | * | |
40 | * argpar_parse() returns a single array of parsing results. | |
41 | * | |
42 | * Both methods parse the arguments `argv` of which the count is `argc` | |
43 | * using the sentinel-terminated (use `ARGPAR_OPT_DESCR_SENTINEL`) | |
44 | * option descriptor array `descrs`. | |
45 | * | |
46 | * argpar considers ALL the elements of `argv`, including the first one, | |
47 | * so that you would typically pass `argc - 1` and `&argv[1]` from what | |
48 | * main() receives. | |
49 | * | |
50 | * The argpar parsers support: | |
51 | * | |
52 | * * Short options without an argument, possibly tied together: | |
53 | * | |
54 | * -f -auf -n | |
55 | * | |
56 | * * Short options with argument: | |
57 | * | |
58 | * -b 45 -f/mein/file -xyzhello | |
59 | * | |
60 | * * Long options without an argument: | |
61 | * | |
62 | * --five-guys --burger-king --pizza-hut --subway | |
63 | * | |
64 | * * Long options with arguments: | |
65 | * | |
66 | * --security enable --time=18.56 | |
67 | * | |
68 | * * Non-option arguments (anything else). | |
69 | * | |
70 | * The argpar parsers don't accept `-` or `--` as arguments. The latter | |
71 | * means "end of options" for many command-line tools, but this library | |
72 | * is all about keeping the order of the arguments, so it doesn't mean | |
73 | * much to put them at the end. This has the side effect that a | |
74 | * non-option argument cannot have the form of an option, for example if | |
75 | * you need to pass the exact relative path `--component`. In that case, | |
76 | * you would need to pass `./--component`. There's no generic way to | |
77 | * escape `-` as of this version. | |
78 | * | |
79 | * Both argpar_iter_create() and argpar_parse() accept duplicate options | |
80 | * (they produce one item for each instance). | |
81 | * | |
82 | * A returned parsing item has the type `struct argpar_item *`. Each | |
83 | * item is to be casted to the appropriate type | |
84 | * (`struct argpar_item_opt *` or `struct argpar_item_non_opt *`) | |
85 | * depending on its `type` member. | |
86 | * | |
87 | * Both argpar_iter_create() and argpar_parse() produce the items in | |
88 | * the same order that the arguments were parsed, including non-option | |
89 | * arguments. This means, for example, that for: | |
90 | * | |
91 | * --hello --count=23 /path/to/file -ab --type file magie | |
92 | * | |
93 | * The produced items are, in this order: | |
94 | * | |
95 | * 1. Option item (`--hello`). | |
96 | * 2. Option item (`--count` with argument `23`). | |
97 | * 3. Non-option item (`/path/to/file`). | |
98 | * 4. Option item (`-a`). | |
99 | * 5. Option item (`-b`). | |
100 | * 6. Option item (`--type` with argument `file`). | |
101 | * 7. Non-option item (`magie`). | |
102 | */ | |
103 | ||
903a5b8a | 104 | /* Sentinel for an option descriptor array */ |
1c9a6bde | 105 | #define ARGPAR_OPT_DESCR_SENTINEL { -1, '\0', NULL, false } |
903a5b8a | 106 | |
7ac57709 | 107 | /* |
fb12ac67 PP |
108 | * If argpar is used in some shared library, we don't want said library |
109 | * to export its symbols, so mark them as "hidden". | |
7ac57709 | 110 | * |
fc07e526 SM |
111 | * On Windows, symbols are local unless explicitly exported; see |
112 | * <https://gcc.gnu.org/wiki/Visibility>. | |
7ac57709 SM |
113 | */ |
114 | #if defined(_WIN32) || defined(__CYGWIN__) | |
fb12ac67 | 115 | # define ARGPAR_HIDDEN |
7ac57709 | 116 | #else |
fb12ac67 | 117 | # define ARGPAR_HIDDEN __attribute__((visibility("hidden"))) |
7ac57709 SM |
118 | #endif |
119 | ||
fc07e526 SM |
120 | /* Forward-declaration for the opaque type */ |
121 | struct argpar_iter; | |
122 | ||
903a5b8a | 123 | /* Option descriptor */ |
1c9a6bde | 124 | struct argpar_opt_descr { |
903a5b8a SM |
125 | /* Numeric ID for this option */ |
126 | const int id; | |
127 | ||
128 | /* Short option character, or `\0` */ | |
129 | const char short_name; | |
130 | ||
131 | /* Long option name (without `--`), or `NULL` */ | |
132 | const char * const long_name; | |
133 | ||
134 | /* True if this option has an argument */ | |
135 | const bool with_arg; | |
136 | }; | |
137 | ||
138 | /* Item type */ | |
1c9a6bde | 139 | enum argpar_item_type { |
903a5b8a | 140 | /* Option */ |
1c9a6bde | 141 | ARGPAR_ITEM_TYPE_OPT, |
903a5b8a SM |
142 | |
143 | /* Non-option */ | |
1c9a6bde | 144 | ARGPAR_ITEM_TYPE_NON_OPT, |
903a5b8a SM |
145 | }; |
146 | ||
147 | /* Base item */ | |
1c9a6bde SM |
148 | struct argpar_item { |
149 | enum argpar_item_type type; | |
903a5b8a SM |
150 | }; |
151 | ||
152 | /* Option item */ | |
1c9a6bde SM |
153 | struct argpar_item_opt { |
154 | struct argpar_item base; | |
903a5b8a SM |
155 | |
156 | /* Corresponding descriptor */ | |
1c9a6bde | 157 | const struct argpar_opt_descr *descr; |
903a5b8a SM |
158 | |
159 | /* Argument, or `NULL` if none */ | |
160 | const char *arg; | |
161 | }; | |
162 | ||
163 | /* Non-option item */ | |
1c9a6bde SM |
164 | struct argpar_item_non_opt { |
165 | struct argpar_item base; | |
903a5b8a SM |
166 | |
167 | /* | |
168 | * Complete argument, pointing to one of the entries of the | |
169 | * original arguments (`argv`). | |
170 | */ | |
171 | const char *arg; | |
172 | ||
173 | /* Index of this argument amongst all original arguments (`argv`) */ | |
174 | unsigned int orig_index; | |
175 | ||
176 | /* Index of this argument amongst other non-option arguments */ | |
177 | unsigned int non_opt_index; | |
178 | }; | |
179 | ||
1c9a6bde | 180 | struct argpar_item_array { |
fb12ac67 | 181 | const struct argpar_item **items; |
7ac57709 | 182 | |
fb12ac67 | 183 | /* Number of used slots in `items` */ |
7ac57709 SM |
184 | unsigned int n_items; |
185 | ||
fb12ac67 | 186 | /* Number of allocated slots in `items` */ |
7ac57709 SM |
187 | unsigned int n_alloc; |
188 | }; | |
189 | ||
1c9a6bde SM |
190 | /* What is returned by argpar_parse() */ |
191 | struct argpar_parse_ret { | |
fc07e526 | 192 | /* |
fb12ac67 | 193 | * Array of parsing items, or `NULL` on error. |
fc07e526 SM |
194 | * |
195 | * Do NOT destroy those items manually with | |
196 | * argpar_iter_destroy(): call argpar_parse_ret_fini() to | |
197 | * finalize the whole structure. | |
198 | */ | |
1c9a6bde | 199 | struct argpar_item_array *items; |
903a5b8a SM |
200 | |
201 | /* Error string, or `NULL` if none */ | |
7ac57709 | 202 | char *error; |
903a5b8a SM |
203 | |
204 | /* Number of original arguments (`argv`) ingested */ | |
205 | unsigned int ingested_orig_args; | |
206 | }; | |
207 | ||
208 | /* | |
fc07e526 SM |
209 | * Parses arguments in `argv` until the end is reached or an error is |
210 | * encountered. | |
903a5b8a | 211 | * |
fc07e526 SM |
212 | * On success, this function returns an array of items (field `items` of |
213 | * `struct argpar_parse_ret`). | |
903a5b8a SM |
214 | * |
215 | * In the returned structure, `ingested_orig_args` is the number of | |
216 | * ingested arguments within `argv` to produce the resulting array of | |
fc07e526 SM |
217 | * items. |
218 | * | |
219 | * If `fail_on_unknown_opt` is true, then on success | |
903a5b8a SM |
220 | * `ingested_orig_args` is equal to `argc`. Otherwise, |
221 | * `ingested_orig_args` contains the number of original arguments until | |
222 | * an unknown _option_ occurs. For example, with | |
223 | * | |
224 | * --great --white contact nuance --shark nuclear | |
225 | * | |
226 | * if `--shark` is not described within `descrs` and | |
227 | * `fail_on_unknown_opt` is false, then `ingested_orig_args` is 4 (two | |
228 | * options, two non-options), whereas `argc` is 6. | |
229 | * | |
230 | * This makes it possible to know where a command name is, for example. | |
231 | * With those arguments: | |
232 | * | |
233 | * --verbose --stuff=23 do-something --specific-opt -f -b | |
234 | * | |
235 | * and the descriptors for `--verbose` and `--stuff` only, the function | |
236 | * returns the `--verbose` and `--stuff` option items, the | |
237 | * `do-something` non-option item, and that three original arguments | |
238 | * were ingested. This means you can start the next argument parsing | |
239 | * stage, with option descriptors depending on the command name, at | |
240 | * `&argv[3]`. | |
241 | * | |
242 | * Note that `ingested_orig_args` is not always equal to the number of | |
243 | * returned items, as | |
244 | * | |
245 | * --hello -fdw | |
246 | * | |
247 | * for example contains two ingested original arguments, but four | |
248 | * resulting items. | |
249 | * | |
fc07e526 SM |
250 | * On failure, the `items` member of the returned structure is `NULL`, |
251 | * and the `error` string member contains details about the error. | |
903a5b8a | 252 | * |
fc07e526 | 253 | * Finalize the returned structure with argpar_parse_ret_fini(). |
903a5b8a | 254 | */ |
7ac57709 | 255 | ARGPAR_HIDDEN |
1c9a6bde | 256 | struct argpar_parse_ret argpar_parse(unsigned int argc, |
903a5b8a | 257 | const char * const *argv, |
1c9a6bde | 258 | const struct argpar_opt_descr *descrs, |
903a5b8a SM |
259 | bool fail_on_unknown_opt); |
260 | ||
261 | /* | |
fc07e526 | 262 | * Finalizes what argpar_parse() returns. |
903a5b8a | 263 | * |
fc07e526 | 264 | * You may call argpar_parse() multiple times with the same structure. |
903a5b8a | 265 | */ |
7ac57709 | 266 | ARGPAR_HIDDEN |
1c9a6bde | 267 | void argpar_parse_ret_fini(struct argpar_parse_ret *ret); |
903a5b8a | 268 | |
fc07e526 SM |
269 | /* |
270 | * Creates an argument parsing iterator. | |
271 | * | |
272 | * This function initializes the returned structure, but doesn't | |
273 | * actually start parsing the arguments. | |
274 | * | |
275 | * `*argv` and `*descrs` must NOT change for the lifetime of the | |
276 | * returned iterator (until you call argpar_iter_destroy()). | |
277 | * | |
278 | * Call argpar_iter_parse_next() with the returned iterator to obtain | |
279 | * the next parsing result (item). | |
280 | */ | |
281 | ARGPAR_HIDDEN | |
282 | struct argpar_iter *argpar_iter_create(unsigned int argc, | |
283 | const char * const *argv, | |
284 | const struct argpar_opt_descr *descrs); | |
285 | ||
286 | /* | |
287 | * Destroys `iter`, as returned by argpar_iter_create(). | |
288 | */ | |
289 | ARGPAR_HIDDEN | |
290 | void argpar_iter_destroy(struct argpar_iter *iter); | |
291 | ||
292 | /* | |
293 | * Return type of argpar_iter_parse_next(). | |
294 | */ | |
295 | enum argpar_iter_parse_next_status { | |
296 | ARGPAR_ITER_PARSE_NEXT_STATUS_OK, | |
297 | ARGPAR_ITER_PARSE_NEXT_STATUS_END, | |
298 | ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT, | |
299 | ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR, | |
300 | }; | |
301 | ||
302 | /* | |
303 | * Parses and returns the next item from `iter`. | |
304 | * | |
305 | * On success, this function sets `*item` to an item which describes the | |
306 | * next option or non-option argument and returns | |
307 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_OK`. Destroy `*item` with | |
308 | * argpar_item_destroy(). | |
309 | * | |
310 | * If there are no more items to return, this function returns | |
311 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_END`. | |
312 | * | |
313 | * On failure (status codes | |
314 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT` and | |
315 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR`), this function sets `*error` | |
316 | * to a descriptive error string. Free `*error` with free(). | |
317 | * | |
318 | * Create an argument parsing iterator with argpar_iter_create(). | |
319 | */ | |
320 | enum argpar_iter_parse_next_status argpar_iter_parse_next( | |
321 | struct argpar_iter *iter, const struct argpar_item **item, | |
322 | char **error); | |
323 | ||
324 | /* | |
325 | * Returns the number of ingested elements from `argv`, as passed to | |
326 | * argpar_iter_create() to create `*iter`, that were required to produce | |
327 | * the previously returned items. | |
328 | */ | |
329 | ARGPAR_HIDDEN | |
330 | unsigned int argpar_iter_get_ingested_orig_args(const struct argpar_iter *iter); | |
331 | ||
332 | /* | |
333 | * Destroys `item`, as created by argpar_iter_parse_next(). | |
334 | */ | |
335 | ARGPAR_HIDDEN | |
336 | void argpar_item_destroy(const struct argpar_item *item); | |
337 | ||
338 | /* | |
339 | * Destroys `_item` (`const struct argpar_item *`) and sets it to | |
340 | * `NULL`. | |
341 | */ | |
fb12ac67 PP |
342 | #define ARGPAR_ITEM_DESTROY_AND_RESET(_item) \ |
343 | { \ | |
344 | argpar_item_destroy(_item); \ | |
345 | _item = NULL; \ | |
fc07e526 SM |
346 | } |
347 | ||
903a5b8a | 348 | #endif /* BABELTRACE_ARGPAR_H */ |