parse-options.hon commit git notes merge: --commit should fail if underlying notes ref has moved (6cfd6a9)
   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        PARSE_OPT_NEGHELP = 128,
  40        PARSE_OPT_SHELL_EVAL = 256
  41};
  42
  43struct option;
  44typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  45
  46/*
  47 * `type`::
  48 *   holds the type of the option, you must have an OPTION_END last in your
  49 *   array.
  50 *
  51 * `short_name`::
  52 *   the character to use as a short option name, '\0' if none.
  53 *
  54 * `long_name`::
  55 *   the long option name, without the leading dashes, NULL if none.
  56 *
  57 * `value`::
  58 *   stores pointers to the values to be filled.
  59 *
  60 * `argh`::
  61 *   token to explain the kind of argument this option wants. Keep it
  62 *   homogeneous across the repository.
  63 *
  64 * `help`::
  65 *   the short help associated to what the option does.
  66 *   Must never be NULL (except for OPTION_END).
  67 *   OPTION_GROUP uses this pointer to store the group header.
  68 *
  69 * `flags`::
  70 *   mask of parse_opt_option_flags.
  71 *   PARSE_OPT_OPTARG: says that the argument is optional (not for BOOLEANs)
  72 *   PARSE_OPT_NOARG: says that this option takes no argument
  73 *   PARSE_OPT_NONEG: says that this option cannot be negated
  74 *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
  75 *                     shown only in the full usage.
  76 *   PARSE_OPT_LASTARG_DEFAULT: says that this option will take the default
  77 *                              value if no argument is given when the option
  78 *                              is last on the command line. If the option is
  79 *                              not last it will require an argument.
  80 *                              Should not be used with PARSE_OPT_OPTARG.
  81 *   PARSE_OPT_NODASH: this option doesn't start with a dash.
  82 *   PARSE_OPT_LITERAL_ARGHELP: says that argh shouldn't be enclosed in brackets
  83 *                              (i.e. '<argh>') in the help message.
  84 *                              Useful for options with multiple parameters.
  85 *   PARSE_OPT_NEGHELP: says that the long option should always be shown with
  86 *                              the --no prefix in the usage message. Sometimes
  87 *                              useful for users of OPTION_NEGBIT.
  88 *
  89 * `callback`::
  90 *   pointer to the callback to use for OPTION_CALLBACK.
  91 *
  92 * `defval`::
  93 *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
  94 *   OPTION_{BIT,SET_INT,SET_PTR} store the {mask,integer,pointer} to put in
  95 *   the value when met.
  96 *   CALLBACKS can use it like they want.
  97 */
  98struct option {
  99        enum parse_opt_type type;
 100        int short_name;
 101        const char *long_name;
 102        void *value;
 103        const char *argh;
 104        const char *help;
 105
 106        int flags;
 107        parse_opt_cb *callback;
 108        intptr_t defval;
 109};
 110
 111#define OPT_END()                   { OPTION_END }
 112#define OPT_ARGUMENT(l, h)          { OPTION_ARGUMENT, 0, (l), NULL, NULL, \
 113                                      (h), PARSE_OPT_NOARG}
 114#define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
 115#define OPT_BIT(s, l, v, h, b)      { OPTION_BIT, (s), (l), (v), NULL, (h), \
 116                                      PARSE_OPT_NOARG, NULL, (b) }
 117#define OPT_NEGBIT(s, l, v, h, b)   { OPTION_NEGBIT, (s), (l), (v), NULL, \
 118                                      (h), PARSE_OPT_NOARG, NULL, (b) }
 119#define OPT_BOOLEAN(s, l, v, h)     { OPTION_BOOLEAN, (s), (l), (v), NULL, \
 120                                      (h), PARSE_OPT_NOARG }
 121#define OPT_SET_INT(s, l, v, h, i)  { OPTION_SET_INT, (s), (l), (v), NULL, \
 122                                      (h), PARSE_OPT_NOARG, NULL, (i) }
 123#define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, \
 124                                      (h), PARSE_OPT_NOARG, NULL, (p) }
 125#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), "n", (h) }
 126#define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
 127#define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
 128                                      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
 129#define OPT_DATE(s, l, v, h) \
 130        { OPTION_CALLBACK, (s), (l), (v), "time",(h), 0, \
 131          parse_opt_approxidate_cb }
 132#define OPT_CALLBACK(s, l, v, a, h, f) \
 133        { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
 134#define OPT_NUMBER_CALLBACK(v, h, f) \
 135        { OPTION_NUMBER, 0, NULL, (v), NULL, (h), \
 136          PARSE_OPT_NOARG | PARSE_OPT_NONEG, (f) }
 137#define OPT_FILENAME(s, l, v, h)    { OPTION_FILENAME, (s), (l), (v), \
 138                                       "FILE", (h) }
 139#define OPT_COLOR_FLAG(s, l, v, h) \
 140        { OPTION_CALLBACK, (s), (l), (v), "when", (h), PARSE_OPT_OPTARG, \
 141                parse_opt_color_flag_cb, (intptr_t)"always" }
 142
 143
 144/* parse_options() will filter out the processed options and leave the
 145 * non-option arguments in argv[].
 146 * Returns the number of arguments left in argv[].
 147 */
 148extern int parse_options(int argc, const char **argv, const char *prefix,
 149                         const struct option *options,
 150                         const char * const usagestr[], int flags);
 151
 152extern NORETURN void usage_with_options(const char * const *usagestr,
 153                                        const struct option *options);
 154
 155extern NORETURN void usage_msg_opt(const char *msg,
 156                                   const char * const *usagestr,
 157                                   const struct option *options);
 158
 159/*----- incremental advanced APIs -----*/
 160
 161enum {
 162        PARSE_OPT_HELP = -1,
 163        PARSE_OPT_DONE,
 164        PARSE_OPT_UNKNOWN
 165};
 166
 167/*
 168 * It's okay for the caller to consume argv/argc in the usual way.
 169 * Other fields of that structure are private to parse-options and should not
 170 * be modified in any way.
 171 */
 172struct parse_opt_ctx_t {
 173        const char **argv;
 174        const char **out;
 175        int argc, cpidx;
 176        const char *opt;
 177        int flags;
 178        const char *prefix;
 179};
 180
 181extern void parse_options_start(struct parse_opt_ctx_t *ctx,
 182                                int argc, const char **argv, const char *prefix,
 183                                int flags);
 184
 185extern int parse_options_step(struct parse_opt_ctx_t *ctx,
 186                              const struct option *options,
 187                              const char * const usagestr[]);
 188
 189extern int parse_options_end(struct parse_opt_ctx_t *ctx);
 190
 191extern int parse_options_concat(struct option *dst, size_t, struct option *src);
 192
 193/*----- some often used options -----*/
 194extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 195extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 196extern int parse_opt_color_flag_cb(const struct option *, const char *, int);
 197extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
 198extern int parse_opt_with_commit(const struct option *, const char *, int);
 199extern int parse_opt_tertiary(const struct option *, const char *, int);
 200
 201#define OPT__VERBOSE(var)  OPT_BOOLEAN('v', "verbose", (var), "be verbose")
 202#define OPT__QUIET(var)    OPT_BOOLEAN('q', "quiet",   (var), "be quiet")
 203#define OPT__VERBOSITY(var) \
 204        { OPTION_CALLBACK, 'v', "verbose", (var), NULL, "be more verbose", \
 205          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
 206        { OPTION_CALLBACK, 'q', "quiet", (var), NULL, "be more quiet", \
 207          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
 208#define OPT__DRY_RUN(var)  OPT_BOOLEAN('n', "dry-run", (var), "dry run")
 209#define OPT__ABBREV(var)  \
 210        { OPTION_CALLBACK, 0, "abbrev", (var), "n", \
 211          "use <n> digits to display SHA-1s", \
 212          PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 213#define OPT__COLOR(var, h) \
 214        OPT_COLOR_FLAG(0, "color", (var), (h))
 215
 216#endif