#ifndef __PERF_PARSE_OPTIONS_H
  #define __PERF_PARSE_OPTIONS_H
  
  #include <linux/kernel.h>
  #include <stdbool.h>
  
  enum parse_opt_type {
  	/* special types */
  	OPTION_END,
  	OPTION_ARGUMENT,
  	OPTION_GROUP,
  	/* options with no arguments */
  	OPTION_BIT,
  	OPTION_BOOLEAN,
  	OPTION_INCR,
  	OPTION_SET_UINT,
  	OPTION_SET_PTR,
  	/* options with arguments (usually) */
  	OPTION_STRING,
  	OPTION_INTEGER,
  	OPTION_LONG,
  	OPTION_CALLBACK,
  	OPTION_U64,
  	OPTION_UINTEGER,
  };
  
  enum parse_opt_flags {
  	PARSE_OPT_KEEP_DASHDASH = 1,
  	PARSE_OPT_STOP_AT_NON_OPTION = 2,
  	PARSE_OPT_KEEP_ARGV0 = 4,
  	PARSE_OPT_KEEP_UNKNOWN = 8,
  	PARSE_OPT_NO_INTERNAL_HELP = 16,
  };
  
  enum parse_opt_option_flags {
  	PARSE_OPT_OPTARG  = 1,
  	PARSE_OPT_NOARG   = 2,
  	PARSE_OPT_NONEG   = 4,
  	PARSE_OPT_HIDDEN  = 8,
  	PARSE_OPT_LASTARG_DEFAULT = 16,
  };
  
  struct option;
  typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  
  /*
   * `type`::
   *   holds the type of the option, you must have an OPTION_END last in your
   *   array.
   *
   * `short_name`::
   *   the character to use as a short option name, '\0' if none.
   *
   * `long_name`::
   *   the long option name, without the leading dashes, NULL if none.
   *
   * `value`::
   *   stores pointers to the values to be filled.
   *
   * `argh`::
   *   token to explain the kind of argument this option wants. Keep it
   *   homogenous across the repository.
   *
   * `help`::
   *   the short help associated to what the option does.
   *   Must never be NULL (except for OPTION_END).
   *   OPTION_GROUP uses this pointer to store the group header.
   *
   * `flags`::
   *   mask of parse_opt_option_flags.
   *   PARSE_OPT_OPTARG: says that the argument is optionnal (not for BOOLEANs)
   *   PARSE_OPT_NOARG: says that this option takes no argument, for CALLBACKs
   *   PARSE_OPT_NONEG: says that this option cannot be negated
   *   PARSE_OPT_HIDDEN this option is skipped in the default usage, showed in
   *                    the long one.
   *
   * `callback`::
   *   pointer to the callback to use for OPTION_CALLBACK.
   *
   * `defval`::
   *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
   *   OPTION_{BIT,SET_UINT,SET_PTR} store the {mask,integer,pointer} to put in
   *   the value when met.
   *   CALLBACKS can use it like they want.
   *
   * `set`::
   *   whether an option was set by the user
   */
  struct option {
  	enum parse_opt_type type;
  	int short_name;
  	const char *long_name;
  	void *value;
  	const char *argh;
  	const char *help;
  
  	int flags;
  	parse_opt_cb *callback;
  	intptr_t defval;
  	bool *set;
  };
  
  #define check_vtype(v, type) ( BUILD_BUG_ON_ZERO(!__builtin_types_compatible_p(typeof(v), type)) + v )
  
  #define OPT_END()                   { .type = OPTION_END }
  #define OPT_ARGUMENT(l, h)          { .type = OPTION_ARGUMENT, .long_name = (l), .help = (h) }
  #define OPT_GROUP(h)                { .type = OPTION_GROUP, .help = (h) }
  #define OPT_BIT(s, l, v, h, b)      { .type = OPTION_BIT, .short_name = (s), .long_name = (l), .value = check_vtype(v, int *), .help = (h), .defval = (b) }
  #define OPT_BOOLEAN(s, l, v, h)     { .type = OPTION_BOOLEAN, .short_name = (s), .long_name = (l), .value = check_vtype(v, bool *), .help = (h) }
  #define OPT_BOOLEAN_SET(s, l, v, os, h) \
  	{ .type = OPTION_BOOLEAN, .short_name = (s), .long_name = (l), \
  	.value = check_vtype(v, bool *), .help = (h), \
  	.set = check_vtype(os, bool *)}
  #define OPT_INCR(s, l, v, h)        { .type = OPTION_INCR, .short_name = (s), .long_name = (l), .value = check_vtype(v, int *), .help = (h) }
  #define OPT_SET_UINT(s, l, v, h, i)  { .type = OPTION_SET_UINT, .short_name = (s), .long_name = (l), .value = check_vtype(v, unsigned int *), .help = (h), .defval = (i) }
  #define OPT_SET_PTR(s, l, v, h, p)  { .type = OPTION_SET_PTR, .short_name = (s), .long_name = (l), .value = (v), .help = (h), .defval = (p) }
  #define OPT_INTEGER(s, l, v, h)     { .type = OPTION_INTEGER, .short_name = (s), .long_name = (l), .value = check_vtype(v, int *), .help = (h) }
  #define OPT_UINTEGER(s, l, v, h)    { .type = OPTION_UINTEGER, .short_name = (s), .long_name = (l), .value = check_vtype(v, unsigned int *), .help = (h) }
  #define OPT_LONG(s, l, v, h)        { .type = OPTION_LONG, .short_name = (s), .long_name = (l), .value = check_vtype(v, long *), .help = (h) }
  #define OPT_U64(s, l, v, h)         { .type = OPTION_U64, .short_name = (s), .long_name = (l), .value = check_vtype(v, u64 *), .help = (h) }
  #define OPT_STRING(s, l, v, a, h)   { .type = OPTION_STRING,  .short_name = (s), .long_name = (l), .value = check_vtype(v, const char **), (a), .help = (h) }
  #define OPT_DATE(s, l, v, h) \
  	{ .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), .argh = "time", .help = (h), .callback = parse_opt_approxidate_cb }
  #define OPT_CALLBACK(s, l, v, a, h, f) \
  	{ .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f) }
  #define OPT_CALLBACK_NOOPT(s, l, v, a, h, f) \
  	{ .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .flags = PARSE_OPT_NOARG }
  #define OPT_CALLBACK_DEFAULT(s, l, v, a, h, f, d) \
  	{ .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l), .value = (v), (a), .help = (h), .callback = (f), .defval = (intptr_t)d, .flags = PARSE_OPT_LASTARG_DEFAULT }
  #define OPT_CALLBACK_DEFAULT_NOOPT(s, l, v, a, h, f, d) \
  	{ .type = OPTION_CALLBACK, .short_name = (s), .long_name = (l),\
  	.value = (v), (a), .help = (h), .callback = (f), .defval = (intptr_t)d,\
  	.flags = PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NOARG}
  
  /* parse_options() will filter out the processed options and leave the
   * non-option argments in argv[].
   * Returns the number of arguments left in argv[].
   */
  extern int parse_options(int argc, const char **argv,
                           const struct option *options,
                           const char * const usagestr[], int flags);
  
  extern NORETURN void usage_with_options(const char * const *usagestr,
                                          const struct option *options);
  
  /*----- incremantal advanced APIs -----*/
  
  enum {
  	PARSE_OPT_HELP = -1,
  	PARSE_OPT_DONE,
  	PARSE_OPT_LIST,
  	PARSE_OPT_UNKNOWN,
  };
  
  /*
   * It's okay for the caller to consume argv/argc in the usual way.
   * Other fields of that structure are private to parse-options and should not
   * be modified in any way.
   */
  struct parse_opt_ctx_t {
  	const char **argv;
  	const char **out;
  	int argc, cpidx;
  	const char *opt;
  	int flags;
  };
  
  extern int parse_options_usage(const char * const *usagestr,
  			       const struct option *opts,
  			       const char *optstr,
  			       bool short_opt);
  
  extern void parse_options_start(struct parse_opt_ctx_t *ctx,
  				int argc, const char **argv, int flags);
  
  extern int parse_options_step(struct parse_opt_ctx_t *ctx,
  			      const struct option *options,
  			      const char * const usagestr[]);
  
  extern int parse_options_end(struct parse_opt_ctx_t *ctx);
  
  
  /*----- some often used options -----*/
  extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
  extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
  extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
  
  #define OPT__VERBOSE(var)  OPT_BOOLEAN('v', "verbose", (var), "be verbose")
  #define OPT__QUIET(var)    OPT_BOOLEAN('q', "quiet",   (var), "be quiet")
  #define OPT__VERBOSITY(var) \
  	{ OPTION_CALLBACK, 'v', "verbose", (var), NULL, "be more verbose", \
  	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
  	{ OPTION_CALLBACK, 'q', "quiet", (var), NULL, "be more quiet", \
  	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
  #define OPT__DRY_RUN(var)  OPT_BOOLEAN('n', "dry-run", (var), "dry run")
  #define OPT__ABBREV(var)  \
  	{ OPTION_CALLBACK, 0, "abbrev", (var), "n", \
  	  "use <n> digits to display SHA-1s", \
  	  PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
  
  extern const char *parse_options_fix_filename(const char *prefix, const char *file);
  
  #endif /* __PERF_PARSE_OPTIONS_H */