| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright 2019 Philippe Proulx <pproulx@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef BABELTRACE_ARGPAR_H |
| 8 | #define BABELTRACE_ARGPAR_H |
| 9 | |
| 10 | #include <stdbool.h> |
| 11 | |
| 12 | /* Sentinel for an option descriptor array */ |
| 13 | #define ARGPAR_OPT_DESCR_SENTINEL { -1, '\0', NULL, false } |
| 14 | |
| 15 | /* |
| 16 | * ARGPAR_HIDDEN: if argpar is used in some shared library, we don't want them |
| 17 | * to be exported by that library, so mark them as "hidden". |
| 18 | * |
| 19 | * On Windows, symbols are local unless explicitly exported, |
| 20 | * see https://gcc.gnu.org/wiki/Visibility |
| 21 | */ |
| 22 | #if defined(_WIN32) || defined(__CYGWIN__) |
| 23 | #define ARGPAR_HIDDEN |
| 24 | #else |
| 25 | #define ARGPAR_HIDDEN __attribute__((visibility("hidden"))) |
| 26 | #endif |
| 27 | |
| 28 | /* Option descriptor */ |
| 29 | struct argpar_opt_descr { |
| 30 | /* Numeric ID for this option */ |
| 31 | const int id; |
| 32 | |
| 33 | /* Short option character, or `\0` */ |
| 34 | const char short_name; |
| 35 | |
| 36 | /* Long option name (without `--`), or `NULL` */ |
| 37 | const char * const long_name; |
| 38 | |
| 39 | /* True if this option has an argument */ |
| 40 | const bool with_arg; |
| 41 | }; |
| 42 | |
| 43 | /* Item type */ |
| 44 | enum argpar_item_type { |
| 45 | /* Option */ |
| 46 | ARGPAR_ITEM_TYPE_OPT, |
| 47 | |
| 48 | /* Non-option */ |
| 49 | ARGPAR_ITEM_TYPE_NON_OPT, |
| 50 | }; |
| 51 | |
| 52 | /* Base item */ |
| 53 | struct argpar_item { |
| 54 | enum argpar_item_type type; |
| 55 | }; |
| 56 | |
| 57 | /* Option item */ |
| 58 | struct argpar_item_opt { |
| 59 | struct argpar_item base; |
| 60 | |
| 61 | /* Corresponding descriptor */ |
| 62 | const struct argpar_opt_descr *descr; |
| 63 | |
| 64 | /* Argument, or `NULL` if none */ |
| 65 | const char *arg; |
| 66 | }; |
| 67 | |
| 68 | /* Non-option item */ |
| 69 | struct argpar_item_non_opt { |
| 70 | struct argpar_item base; |
| 71 | |
| 72 | /* |
| 73 | * Complete argument, pointing to one of the entries of the |
| 74 | * original arguments (`argv`). |
| 75 | */ |
| 76 | const char *arg; |
| 77 | |
| 78 | /* Index of this argument amongst all original arguments (`argv`) */ |
| 79 | unsigned int orig_index; |
| 80 | |
| 81 | /* Index of this argument amongst other non-option arguments */ |
| 82 | unsigned int non_opt_index; |
| 83 | }; |
| 84 | |
| 85 | struct argpar_item_array { |
| 86 | /* Array of `struct argpar_item *`, or `NULL` on error */ |
| 87 | struct argpar_item **items; |
| 88 | |
| 89 | /* Number of used slots in `items`. */ |
| 90 | unsigned int n_items; |
| 91 | |
| 92 | /* Number of allocated slots in `items`. */ |
| 93 | unsigned int n_alloc; |
| 94 | }; |
| 95 | |
| 96 | /* What is returned by argpar_parse() */ |
| 97 | struct argpar_parse_ret { |
| 98 | /* Array of `struct argpar_item *`, or `NULL` on error */ |
| 99 | struct argpar_item_array *items; |
| 100 | |
| 101 | /* Error string, or `NULL` if none */ |
| 102 | char *error; |
| 103 | |
| 104 | /* Number of original arguments (`argv`) ingested */ |
| 105 | unsigned int ingested_orig_args; |
| 106 | }; |
| 107 | |
| 108 | /* |
| 109 | * Parses the arguments `argv` of which the count is `argc` using the |
| 110 | * sentinel-terminated (use `ARGPAR_OPT_DESCR_SENTINEL`) option |
| 111 | * descriptor array `descrs`. |
| 112 | * |
| 113 | * This function considers ALL the elements of `argv`, including the |
| 114 | * first one, so that you would typically pass `argc - 1` and |
| 115 | * `&argv[1]` from what main() receives. |
| 116 | * |
| 117 | * This argument parser supports: |
| 118 | * |
| 119 | * * Short options without an argument, possibly tied together: |
| 120 | * |
| 121 | * -f -auf -n |
| 122 | * |
| 123 | * * Short options with argument: |
| 124 | * |
| 125 | * -b 45 -f/mein/file -xyzhello |
| 126 | * |
| 127 | * * Long options without an argument: |
| 128 | * |
| 129 | * --five-guys --burger-king --pizza-hut --subway |
| 130 | * |
| 131 | * * Long options with arguments: |
| 132 | * |
| 133 | * --security enable --time=18.56 |
| 134 | * |
| 135 | * * Non-option arguments (anything else). |
| 136 | * |
| 137 | * This function does not accept `-` or `--` as arguments. The latter |
| 138 | * means "end of options" for many command-line tools, but this function |
| 139 | * is all about keeping the order of the arguments, so it does not mean |
| 140 | * much to put them at the end. This has the side effect that a |
| 141 | * non-option argument cannot have the form of an option, for example if |
| 142 | * you need to pass the exact relative path `--component`. In that case, |
| 143 | * you would need to pass `./--component`. There's no generic way to |
| 144 | * escape `-` for the moment. |
| 145 | * |
| 146 | * This function accepts duplicate options (the resulting array of items |
| 147 | * contains one entry for each instance). |
| 148 | * |
| 149 | * On success, this function returns an array of items |
| 150 | * (`struct argpar_item *`). Each item is to be casted to the |
| 151 | * appropriate type (`struct argpar_item_opt *` or |
| 152 | * `struct argpar_item_non_opt *`) depending on its type. |
| 153 | * |
| 154 | * The returned array contains the items in the same order that the |
| 155 | * arguments were parsed, including non-option arguments. This means, |
| 156 | * for example, that for |
| 157 | * |
| 158 | * --hello --meow=23 /path/to/file -b |
| 159 | * |
| 160 | * the function returns an array of four items: two options, one |
| 161 | * non-option, and one option. |
| 162 | * |
| 163 | * In the returned structure, `ingested_orig_args` is the number of |
| 164 | * ingested arguments within `argv` to produce the resulting array of |
| 165 | * items. If `fail_on_unknown_opt` is true, then on success |
| 166 | * `ingested_orig_args` is equal to `argc`. Otherwise, |
| 167 | * `ingested_orig_args` contains the number of original arguments until |
| 168 | * an unknown _option_ occurs. For example, with |
| 169 | * |
| 170 | * --great --white contact nuance --shark nuclear |
| 171 | * |
| 172 | * if `--shark` is not described within `descrs` and |
| 173 | * `fail_on_unknown_opt` is false, then `ingested_orig_args` is 4 (two |
| 174 | * options, two non-options), whereas `argc` is 6. |
| 175 | * |
| 176 | * This makes it possible to know where a command name is, for example. |
| 177 | * With those arguments: |
| 178 | * |
| 179 | * --verbose --stuff=23 do-something --specific-opt -f -b |
| 180 | * |
| 181 | * and the descriptors for `--verbose` and `--stuff` only, the function |
| 182 | * returns the `--verbose` and `--stuff` option items, the |
| 183 | * `do-something` non-option item, and that three original arguments |
| 184 | * were ingested. This means you can start the next argument parsing |
| 185 | * stage, with option descriptors depending on the command name, at |
| 186 | * `&argv[3]`. |
| 187 | * |
| 188 | * Note that `ingested_orig_args` is not always equal to the number of |
| 189 | * returned items, as |
| 190 | * |
| 191 | * --hello -fdw |
| 192 | * |
| 193 | * for example contains two ingested original arguments, but four |
| 194 | * resulting items. |
| 195 | * |
| 196 | * On failure, the returned structure's `items` member is `NULL`, and |
| 197 | * the `error` string member contains details about the error. |
| 198 | * |
| 199 | * You can finalize the returned structure with |
| 200 | * argpar_parse_ret_fini(). |
| 201 | */ |
| 202 | ARGPAR_HIDDEN |
| 203 | struct argpar_parse_ret argpar_parse(unsigned int argc, |
| 204 | const char * const *argv, |
| 205 | const struct argpar_opt_descr *descrs, |
| 206 | bool fail_on_unknown_opt); |
| 207 | |
| 208 | /* |
| 209 | * Finalizes what is returned by argpar_parse(). |
| 210 | * |
| 211 | * It is safe to call argpar_parse() multiple times with the same |
| 212 | * structure. |
| 213 | */ |
| 214 | ARGPAR_HIDDEN |
| 215 | void argpar_parse_ret_fini(struct argpar_parse_ret *ret); |
| 216 | |
| 217 | #endif /* BABELTRACE_ARGPAR_H */ |