parse-options.hon commit parse-options: simplify usage argh handling (34aec9f)
   1#ifndef PARSE_OPTIONS_H
   2#define PARSE_OPTIONS_H
   3
   4enum parse_opt_type {
   5        /* special types */
   6        OPTION_END,
   7        OPTION_ARGUMENT,
   8        OPTION_GROUP,
   9        OPTION_NUMBER,
  10        /* options with no arguments */
  11        OPTION_BIT,
  12        OPTION_NEGBIT,
  13        OPTION_BOOLEAN, /* _INCR would have been a better name */
  14        OPTION_SET_INT,
  15        OPTION_SET_PTR,
  16        /* options with arguments (usually) */
  17        OPTION_STRING,
  18        OPTION_INTEGER,
  19        OPTION_CALLBACK,
  20        OPTION_FILENAME
  21};
  22
  23enum parse_opt_flags {
  24        PARSE_OPT_KEEP_DASHDASH = 1,
  25        PARSE_OPT_STOP_AT_NON_OPTION = 2,
  26        PARSE_OPT_KEEP_ARGV0 = 4,
  27        PARSE_OPT_KEEP_UNKNOWN = 8,
  28        PARSE_OPT_NO_INTERNAL_HELP = 16,
  29};
  30
  31enum parse_opt_option_flags {
  32        PARSE_OPT_OPTARG  = 1,
  33        PARSE_OPT_NOARG   = 2,
  34        PARSE_OPT_NONEG   = 4,
  35        PARSE_OPT_HIDDEN  = 8,
  36        PARSE_OPT_LASTARG_DEFAULT = 16,
  37        PARSE_OPT_NODASH = 32,
  38        PARSE_OPT_LITERAL_ARGHELP = 64,
  39};
  40
  41struct option;
  42typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  43
  44/*
  45 * `type`::
  46 *   holds the type of the option, you must have an OPTION_END last in your
  47 *   array.
  48 *
  49 * `short_name`::
  50 *   the character to use as a short option name, '\0' if none.
  51 *
  52 * `long_name`::
  53 *   the long option name, without the leading dashes, NULL if none.
  54 *
  55 * `value`::
  56 *   stores pointers to the values to be filled.
  57 *
  58 * `argh`::
  59 *   token to explain the kind of argument this option wants. Keep it
  60 *   homogeneous across the repository.
  61 *
  62 * `help`::
  63 *   the short help associated to what the option does.
  64 *   Must never be NULL (except for OPTION_END).
  65 *   OPTION_GROUP uses this pointer to store the group header.
  66 *
  67 * `flags`::
  68 *   mask of parse_opt_option_flags.
  69 *   PARSE_OPT_OPTARG: says that the argument is optional (not for BOOLEANs)
  70 *   PARSE_OPT_NOARG: says that this option takes no argument
  71 *   PARSE_OPT_NONEG: says that this option cannot be negated
  72 *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
  73 *                     shown only in the full usage.
  74 *   PARSE_OPT_LASTARG_DEFAULT: if no argument is given, the default value
  75 *                              is used.
  76 *   PARSE_OPT_NODASH: this option doesn't start with a dash.
  77 *   PARSE_OPT_LITERAL_ARGHELP: says that argh shouldn't be enclosed in brackets
  78 *                              (i.e. '<argh>') in the help message.
  79 *                              Useful for options with multiple parameters.
  80 *
  81 * `callback`::
  82 *   pointer to the callback to use for OPTION_CALLBACK.
  83 *
  84 * `defval`::
  85 *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
  86 *   OPTION_{BIT,SET_INT,SET_PTR} store the {mask,integer,pointer} to put in
  87 *   the value when met.
  88 *   CALLBACKS can use it like they want.
  89 */
  90struct option {
  91        enum parse_opt_type type;
  92        int short_name;
  93        const char *long_name;
  94        void *value;
  95        const char *argh;
  96        const char *help;
  97
  98        int flags;
  99        parse_opt_cb *callback;
 100        intptr_t defval;
 101};
 102
 103#define OPT_END()                   { OPTION_END }
 104#define OPT_ARGUMENT(l, h)          { OPTION_ARGUMENT, 0, (l), NULL, NULL, \
 105                                      (h), PARSE_OPT_NOARG}
 106#define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
 107#define OPT_BIT(s, l, v, h, b)      { OPTION_BIT, (s), (l), (v), NULL, (h), \
 108                                      PARSE_OPT_NOARG, NULL, (b) }
 109#define OPT_NEGBIT(s, l, v, h, b)   { OPTION_NEGBIT, (s), (l), (v), NULL, \
 110                                      (h), PARSE_OPT_NOARG, NULL, (b) }
 111#define OPT_BOOLEAN(s, l, v, h)     { OPTION_BOOLEAN, (s), (l), (v), NULL, \
 112                                      (h), PARSE_OPT_NOARG }
 113#define OPT_SET_INT(s, l, v, h, i)  { OPTION_SET_INT, (s), (l), (v), NULL, \
 114                                      (h), PARSE_OPT_NOARG, NULL, (i) }
 115#define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, \
 116                                      (h), PARSE_OPT_NOARG, NULL, (p) }
 117#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), "n", (h) }
 118#define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
 119#define OPT_DATE(s, l, v, h) \
 120        { OPTION_CALLBACK, (s), (l), (v), "time",(h), 0, \
 121          parse_opt_approxidate_cb }
 122#define OPT_CALLBACK(s, l, v, a, h, f) \
 123        { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
 124#define OPT_NUMBER_CALLBACK(v, h, f) \
 125        { OPTION_NUMBER, 0, NULL, (v), NULL, (h), \
 126          PARSE_OPT_NOARG | PARSE_OPT_NONEG, (f) }
 127#define OPT_FILENAME(s, l, v, h)    { OPTION_FILENAME, (s), (l), (v), \
 128                                       "FILE", (h) }
 129
 130/* parse_options() will filter out the processed options and leave the
 131 * non-option arguments in argv[].
 132 * Returns the number of arguments left in argv[].
 133 */
 134extern int parse_options(int argc, const char **argv, const char *prefix,
 135                         const struct option *options,
 136                         const char * const usagestr[], int flags);
 137
 138extern NORETURN void usage_with_options(const char * const *usagestr,
 139                                        const struct option *options);
 140
 141/*----- incremental advanced APIs -----*/
 142
 143enum {
 144        PARSE_OPT_HELP = -1,
 145        PARSE_OPT_DONE,
 146        PARSE_OPT_UNKNOWN,
 147};
 148
 149/*
 150 * It's okay for the caller to consume argv/argc in the usual way.
 151 * Other fields of that structure are private to parse-options and should not
 152 * be modified in any way.
 153 */
 154struct parse_opt_ctx_t {
 155        const char **argv;
 156        const char **out;
 157        int argc, cpidx;
 158        const char *opt;
 159        int flags;
 160        const char *prefix;
 161};
 162
 163extern int parse_options_usage(const char * const *usagestr,
 164                               const struct option *opts);
 165
 166extern void parse_options_start(struct parse_opt_ctx_t *ctx,
 167                                int argc, const char **argv, const char *prefix,
 168                                int flags);
 169
 170extern int parse_options_step(struct parse_opt_ctx_t *ctx,
 171                              const struct option *options,
 172                              const char * const usagestr[]);
 173
 174extern int parse_options_end(struct parse_opt_ctx_t *ctx);
 175
 176
 177/*----- some often used options -----*/
 178extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 179extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 180extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
 181extern int parse_opt_with_commit(const struct option *, const char *, int);
 182
 183#define OPT__VERBOSE(var)  OPT_BOOLEAN('v', "verbose", (var), "be verbose")
 184#define OPT__QUIET(var)    OPT_BOOLEAN('q', "quiet",   (var), "be quiet")
 185#define OPT__VERBOSITY(var) \
 186        { OPTION_CALLBACK, 'v', "verbose", (var), NULL, "be more verbose", \
 187          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
 188        { OPTION_CALLBACK, 'q', "quiet", (var), NULL, "be more quiet", \
 189          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
 190#define OPT__DRY_RUN(var)  OPT_BOOLEAN('n', "dry-run", (var), "dry run")
 191#define OPT__ABBREV(var)  \
 192        { OPTION_CALLBACK, 0, "abbrev", (var), "n", \
 193          "use <n> digits to display SHA-1s", \
 194          PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 195
 196#endif