ccan/ccan/autodata/_info

#include "config.h"
#include <stdio.h>
#include <string.h>

/**
 * autodata - stash pointers in your binary for automatic registration
 *
 * This code allows declarations in your source which you can gather
 * together at runtime to form tables.  This is often used in place of
 * having a central registration function or table.
 *
 * Note that this technique does not work in general for shared libaries,
 * only for code compiled into a binary.
 *
 * License: BSD-MIT
 *
 * Example:
 * // Distributed commandline option registration (note: ccan/opt is better!)
 * #include <ccan/autodata/autodata.h>
 * #include <stdio.h>
 * #include <unistd.h>
 * #include <stdbool.h>
 * #include <err.h>
 *
 * static bool verbose = false;
 *
 * // This would normally be in a header, so any C file can use it.
 * struct option {
 *	char c;
 *	bool takes_arg;
 *	bool (*cb)(char *optarg);
 * };
 * AUTODATA_TYPE(options, struct option);
 * #define REGISTER_OPTION(optstruct) \
 *		AUTODATA(options, (optstruct))
 *
 * // Now a few examples (could be anywhere in source)
 * static bool verbose_cb(char *unused)
 * {
 *	verbose = true;
 *      return true;
 * }
 * static struct option dash_v = { 'v', false, verbose_cb };
 * REGISTER_OPTION(&dash_v);
 *
 * static bool chdir_cb(char *dir)
 * {
 *	if (verbose)
 *		printf("chdir to %s. ", dir);
 *	if (chdir(dir) != 0)
 *		return false;
 *      return true;
 * }
 * static struct option dash_C = { 'C', true, chdir_cb };
 * REGISTER_OPTION(&dash_C);
 *
 * int main(int argc, char *argv[])
 * {
 * 	struct option **opts;
 *	size_t i, num;
 *	int o;
 *	char *optstring, *p;
 *
 *	// Gather together all the registered options.
 *	opts = autodata_get(options, &num);
 *
 *	// Make pretty string for getopt().
 *	p = optstring = malloc(num * 2 + 1);
 *	for (i = 0; i < num; i++) {
 *		*(p++) = opts[i]->c;
 *		if (opts[i]->takes_arg)
 *			*(p++) = ':';
 *	}
 *	*p = '\0';
 *
 *	while ((o = getopt(argc, argv, optstring)) != -1) {
 *		if (o == '?')
 *			exit(1);
 *		// Call callback in matching option.
 *		for (i = 0; i < num; i++) {
 *			if (opts[i]->c == o) {
 *				if (!opts[i]->cb(optarg))
 *					err(1, "parsing -%c", o);
 *				break;
 *			}
 *		}
 *	}
 *	// free up gathered option table.
 *	autodata_free(opts);
 *
 *	if (verbose)
 *		printf("verbose mode on\n");
 *	return 0;
 * }
 * // Given -v outputs 'verbose mode on'
 * // Given -v -C / outputs 'chdir to /. verbose mode on'
 */
int main(int argc, char *argv[])
{
	/* Expect exactly one argument */
	if (argc != 2)
		return 1;

	if (strcmp(argv[1], "depends") == 0) {
		printf("ccan/compiler\n");
		printf("ccan/ptr_valid\n");
		return 0;
	}

	return 1;
}