parse-options.h

#ifndef PARSE_OPTIONS_H
#define PARSE_OPTIONS_H

enum parse_opt_type {
	/* special types */
	OPTION_END,
	OPTION_ARGUMENT,
	OPTION_GROUP,
	OPTION_NUMBER,
	OPTION_ALIAS,
	/* options with no arguments */
	OPTION_BIT,
	OPTION_NEGBIT,
	OPTION_BITOP,
	OPTION_COUNTUP,
	OPTION_SET_INT,
	OPTION_CMDMODE,
	/* options with arguments (usually) */
	OPTION_STRING,
	OPTION_INTEGER,
	OPTION_MAGNITUDE,
	OPTION_CALLBACK,
	OPTION_LOWLEVEL_CALLBACK,
	OPTION_FILENAME
};

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,
	PARSE_OPT_ONE_SHOT = 32
};

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,
	PARSE_OPT_NODASH = 32,
	PARSE_OPT_LITERAL_ARGHELP = 64,
	PARSE_OPT_SHELL_EVAL = 256,
	PARSE_OPT_NOCOMPLETE = 512,
	PARSE_OPT_COMP_ARG = 1024
};

struct option;
typedef int parse_opt_cb(const struct option *, const char *arg, int unset);

struct parse_opt_ctx_t;
typedef enum parse_opt_result parse_opt_ll_cb(struct parse_opt_ctx_t *ctx,
					      const struct option *opt,
					      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
 *   homogeneous across the repository. Should be wrapped by N_() for
 *   translation.
 *
 * `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.
 *   Should be wrapped by N_() for translation.
 *
 * `flags`::
 *   mask of parse_opt_option_flags.
 *   PARSE_OPT_OPTARG: says that the argument is optional (not for BOOLEANs)
 *   PARSE_OPT_NOARG: says that this option does not take an argument
 *   PARSE_OPT_NONEG: says that this option cannot be negated
 *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
 *                     shown only in the full usage.
 *   PARSE_OPT_LASTARG_DEFAULT: says that this option will take the default
 *				value if no argument is given when the option
 *				is last on the command line. If the option is
 *				not last it will require an argument.
 *				Should not be used with PARSE_OPT_OPTARG.
 *   PARSE_OPT_NODASH: this option doesn't start with a dash.
 *   PARSE_OPT_LITERAL_ARGHELP: says that argh shouldn't be enclosed in brackets
 *				(i.e. '<argh>') in the help message.
 *				Useful for options with multiple parameters.
 *   PARSE_OPT_NOCOMPLETE: by default all visible options are completable
 *			   by git-completion.bash. This option suppresses that.
 *   PARSE_OPT_COMP_ARG: this option forces to git-completion.bash to
 *			 complete an option as --name= not --name even if
 *			 the option takes optional argument.
 *
 * `callback`::
 *   pointer to the callback to use for OPTION_CALLBACK
 *
 * `defval`::
 *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
 *   OPTION_{BIT,SET_INT} store the {mask,integer} to put in the value when met.
 *   CALLBACKS can use it like they want.
 *
 * `ll_callback`::
 *   pointer to the callback to use for OPTION_LOWLEVEL_CALLBACK
 *
 */
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;
	parse_opt_ll_cb *ll_callback;
	intptr_t extra;
};

#define OPT_BIT_F(s, l, v, h, b, f) { OPTION_BIT, (s), (l), (v), NULL, (h), \
				      PARSE_OPT_NOARG|(f), NULL, (b) }
#define OPT_COUNTUP_F(s, l, v, h, f) { OPTION_COUNTUP, (s), (l), (v), NULL, \
				       (h), PARSE_OPT_NOARG|(f) }
#define OPT_SET_INT_F(s, l, v, h, i, f) { OPTION_SET_INT, (s), (l), (v), NULL, \
					  (h), PARSE_OPT_NOARG | (f), NULL, (i) }
#define OPT_BOOL_F(s, l, v, h, f)   OPT_SET_INT_F(s, l, v, h, 1, f)
#define OPT_CALLBACK_F(s, l, v, a, h, f, cb)			\
	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), (cb) }
#define OPT_STRING_F(s, l, v, a, h, f)   { OPTION_STRING,  (s), (l), (v), (a), (h), (f) }
#define OPT_INTEGER_F(s, l, v, h, f)     { OPTION_INTEGER, (s), (l), (v), N_("n"), (h), (f) }

#define OPT_END()                   { OPTION_END }
#define OPT_ARGUMENT(l, v, h)       { OPTION_ARGUMENT, 0, (l), (v), NULL, \
				      (h), PARSE_OPT_NOARG, NULL, 1 }
#define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
#define OPT_BIT(s, l, v, h, b)      OPT_BIT_F(s, l, v, h, b, 0)
#define OPT_BITOP(s, l, v, h, set, clear) { OPTION_BITOP, (s), (l), (v), NULL, (h), \
					    PARSE_OPT_NOARG|PARSE_OPT_NONEG, NULL, \
					    (set), NULL, (clear) }
#define OPT_NEGBIT(s, l, v, h, b)   { OPTION_NEGBIT, (s), (l), (v), NULL, \
				      (h), PARSE_OPT_NOARG, NULL, (b) }
#define OPT_COUNTUP(s, l, v, h)     OPT_COUNTUP_F(s, l, v, h, 0)
#define OPT_SET_INT(s, l, v, h, i)  OPT_SET_INT_F(s, l, v, h, i, 0)
#define OPT_BOOL(s, l, v, h)        OPT_BOOL_F(s, l, v, h, 0)
#define OPT_HIDDEN_BOOL(s, l, v, h) { OPTION_SET_INT, (s), (l), (v), NULL, \
				      (h), PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1}
#define OPT_CMDMODE(s, l, v, h, i)  { OPTION_CMDMODE, (s), (l), (v), NULL, \
				      (h), PARSE_OPT_NOARG|PARSE_OPT_NONEG, NULL, (i) }
#define OPT_INTEGER(s, l, v, h)     OPT_INTEGER_F(s, l, v, h, 0)
#define OPT_MAGNITUDE(s, l, v, h)   { OPTION_MAGNITUDE, (s), (l), (v), \
				      N_("n"), (h), PARSE_OPT_NONEG }
#define OPT_STRING(s, l, v, a, h)   OPT_STRING_F(s, l, v, a, h, 0)
#define OPT_STRING_LIST(s, l, v, a, h) \
				    { OPTION_CALLBACK, (s), (l), (v), (a), \
				      (h), 0, &parse_opt_string_list }
#define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
				      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
#define OPT_EXPIRY_DATE(s, l, v, h) \
	{ OPTION_CALLBACK, (s), (l), (v), N_("expiry-date"),(h), 0,	\
	  parse_opt_expiry_date_cb }
#define OPT_CALLBACK(s, l, v, a, h, f) OPT_CALLBACK_F(s, l, v, a, h, 0, f)
#define OPT_NUMBER_CALLBACK(v, h, f) \
	{ OPTION_NUMBER, 0, NULL, (v), NULL, (h), \
	  PARSE_OPT_NOARG | PARSE_OPT_NONEG, (f) }
#define OPT_FILENAME(s, l, v, h)    { OPTION_FILENAME, (s), (l), (v), \
				       N_("file"), (h) }
#define OPT_COLOR_FLAG(s, l, v, h) \
	{ OPTION_CALLBACK, (s), (l), (v), N_("when"), (h), PARSE_OPT_OPTARG, \
		parse_opt_color_flag_cb, (intptr_t)"always" }

#define OPT_NOOP_NOARG(s, l) \
	{ OPTION_CALLBACK, (s), (l), NULL, NULL, \
	  N_("no-op (backward compatibility)"),		\
	  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, parse_opt_noop_cb }

#define OPT_ALIAS(s, l, source_long_name) \
	{ OPTION_ALIAS, (s), (l), (source_long_name) }

/*
 * parse_options() will filter out the processed options and leave the
 * non-option arguments in argv[]. argv0 is assumed program name and
 * skipped.
 *
 * usagestr strings should be marked for translation with N_().
 *
 * Returns the number of arguments left in argv[].
 *
 * In one-shot mode, argv0 is not a program name, argv[] is left
 * untouched and parse_options() returns the number of options
 * processed.
 */
int parse_options(int argc, const char **argv, const char *prefix,
		  const struct option *options,
		  const char * const usagestr[], int flags);

NORETURN void usage_with_options(const char * const *usagestr,
				 const struct option *options);

NORETURN void usage_msg_opt(const char *msg,
			    const char * const *usagestr,
			    const struct option *options);

int optbug(const struct option *opt, const char *reason);
const char *optname(const struct option *opt, int flags);

/*
 * Use these assertions for callbacks that expect to be called with NONEG and
 * NOARG respectively, and do not otherwise handle the "unset" and "arg"
 * parameters.
 */
#define BUG_ON_OPT_NEG(unset) do { \
	if ((unset)) \
		BUG("option callback does not expect negation"); \
} while (0)
#define BUG_ON_OPT_ARG(arg) do { \
	if ((arg)) \
		BUG("option callback does not expect an argument"); \
} while (0)

/*
 * Similar to the assertions above, but checks that "arg" is always non-NULL.
 * This assertion also implies BUG_ON_OPT_NEG(), letting you declare both
 * assertions in a single line.
 */
#define BUG_ON_OPT_NEG_NOARG(unset, arg) do { \
	BUG_ON_OPT_NEG(unset); \
	if(!(arg)) \
		BUG("option callback expects an argument"); \
} while(0)

/*----- incremental advanced APIs -----*/

enum parse_opt_result {
	PARSE_OPT_COMPLETE = -3,
	PARSE_OPT_HELP = -2,
	PARSE_OPT_ERROR = -1,	/* must be the same as error() */
	PARSE_OPT_DONE = 0,	/* fixed so that "return 0" works */
	PARSE_OPT_NON_OPTION,
	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, total;
	const char *opt;
	int flags;
	const char *prefix;
	const char **alias_groups; /* must be in groups of 3 elements! */
	struct option *updated_options;
};

void parse_options_start(struct parse_opt_ctx_t *ctx,
			 int argc, const char **argv, const char *prefix,
			 const struct option *options, int flags);

int parse_options_step(struct parse_opt_ctx_t *ctx,
		       const struct option *options,
		       const char * const usagestr[]);

int parse_options_end(struct parse_opt_ctx_t *ctx);

struct option *parse_options_dup(const struct option *a);
struct option *parse_options_concat(struct option *a, struct option *b);

/*----- some often used options -----*/
int parse_opt_abbrev_cb(const struct option *, const char *, int);
int parse_opt_expiry_date_cb(const struct option *, const char *, int);
int parse_opt_color_flag_cb(const struct option *, const char *, int);
int parse_opt_verbosity_cb(const struct option *, const char *, int);
/* value is struct oid_array* */
int parse_opt_object_name(const struct option *, const char *, int);
/* value is struct object_id* */
int parse_opt_object_id(const struct option *, const char *, int);
int parse_opt_commits(const struct option *, const char *, int);
int parse_opt_commit(const struct option *, const char *, int);
int parse_opt_tertiary(const struct option *, const char *, int);
int parse_opt_string_list(const struct option *, const char *, int);
int parse_opt_noop_cb(const struct option *, const char *, int);
enum parse_opt_result parse_opt_unknown_cb(struct parse_opt_ctx_t *ctx,
					   const struct option *,
					   const char *, int);
int parse_opt_passthru(const struct option *, const char *, int);
int parse_opt_passthru_argv(const struct option *, const char *, int);

#define OPT__VERBOSE(var, h)  OPT_COUNTUP('v', "verbose", (var), (h))
#define OPT__QUIET(var, h)    OPT_COUNTUP('q', "quiet",   (var), (h))
#define OPT__VERBOSITY(var) \
	{ OPTION_CALLBACK, 'v', "verbose", (var), NULL, N_("be more verbose"), \
	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
	{ OPTION_CALLBACK, 'q', "quiet", (var), NULL, N_("be more quiet"), \
	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
#define OPT__DRY_RUN(var, h)  OPT_BOOL('n', "dry-run", (var), (h))
#define OPT__FORCE(var, h, f) OPT_COUNTUP_F('f', "force",   (var), (h), (f))
#define OPT__ABBREV(var)  \
	{ OPTION_CALLBACK, 0, "abbrev", (var), N_("n"),	\
	  N_("use <n> digits to display SHA-1s"),	\
	  PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
#define OPT__COLOR(var, h) \
	OPT_COLOR_FLAG(0, "color", (var), (h))
#define OPT_COLUMN(s, l, v, h) \
	{ OPTION_CALLBACK, (s), (l), (v), N_("style"), (h), PARSE_OPT_OPTARG, parseopt_column_callback }
#define OPT_PASSTHRU(s, l, v, a, h, f) \
	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), parse_opt_passthru }
#define OPT_PASSTHRU_ARGV(s, l, v, a, h, f) \
	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), parse_opt_passthru_argv }
#define _OPT_CONTAINS_OR_WITH(name, variable, help, flag) \
	{ OPTION_CALLBACK, 0, name, (variable), N_("commit"), (help), \
	  PARSE_OPT_LASTARG_DEFAULT | flag, \
	  parse_opt_commits, (intptr_t) "HEAD" \
	}
#define OPT_CONTAINS(v, h) _OPT_CONTAINS_OR_WITH("contains", v, h, PARSE_OPT_NONEG)
#define OPT_NO_CONTAINS(v, h) _OPT_CONTAINS_OR_WITH("no-contains", v, h, PARSE_OPT_NONEG)
#define OPT_WITH(v, h) _OPT_CONTAINS_OR_WITH("with", v, h, PARSE_OPT_HIDDEN | PARSE_OPT_NONEG)
#define OPT_WITHOUT(v, h) _OPT_CONTAINS_OR_WITH("without", v, h, PARSE_OPT_HIDDEN | PARSE_OPT_NONEG)
#define OPT_CLEANUP(v) OPT_STRING(0, "cleanup", v, N_("mode"), N_("how to strip spaces and #comments from message"))

#endif