Systemd/src/basic/string-table.h
Lennart Poettering b18b866215 basic: add string table macros for "extended boolean" enums
In a couple of cases we maintain configuration settings that know an on
and off state, like a boolean, plus some additional states. We generally
parse them as booleans first, and if that fails check for specific
additional values.

This adds a generalized set of macros for parsing such settings, and
ports one use in resolved and another in networkd over to it.
2016-01-05 17:30:43 +01:00

108 lines
5.7 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "macro.h"
#include "parse-util.h"
#include "string-util.h"
ssize_t string_table_lookup(const char * const *table, size_t len, const char *key);
/* For basic lookup tables with strictly enumerated entries */
#define _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope) \
scope const char *name##_to_string(type i) { \
if (i < 0 || i >= (type) ELEMENTSOF(name##_table)) \
return NULL; \
return name##_table[i]; \
}
#define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope) \
scope type name##_from_string(const char *s) { \
return (type) string_table_lookup(name##_table, ELEMENTSOF(name##_table), s); \
}
#define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(name,type,yes,scope) \
scope type name##_from_string(const char *s) { \
int b; \
b = parse_boolean(s); \
if (b == 0) \
return (type) 0; \
else if (b > 0) \
return yes; \
return (type) string_table_lookup(name##_table, ELEMENTSOF(name##_table), s); \
}
#define _DEFINE_STRING_TABLE_LOOKUP(name,type,scope) \
_DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope) \
_DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope) \
struct __useless_struct_to_allow_trailing_semicolon__
#define _DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes,scope) \
_DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope) \
_DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(name,type,yes,scope) \
struct __useless_struct_to_allow_trailing_semicolon__
#define DEFINE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,)
#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,static)
#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,static)
#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,static)
#define DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes) _DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes,)
/* For string conversions where numbers are also acceptable */
#define DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(name,type,max) \
int name##_to_string_alloc(type i, char **str) { \
char *s; \
if (i < 0 || i > max) \
return -ERANGE; \
if (i < (type) ELEMENTSOF(name##_table)) { \
s = strdup(name##_table[i]); \
if (!s) \
return -ENOMEM; \
} else { \
if (asprintf(&s, "%i", i) < 0) \
return -ENOMEM; \
} \
*str = s; \
return 0; \
} \
type name##_from_string(const char *s) { \
type i; \
unsigned u = 0; \
if (!s) \
return (type) -1; \
for (i = 0; i < (type) ELEMENTSOF(name##_table); i++) \
if (streq_ptr(name##_table[i], s)) \
return i; \
if (safe_atou(s, &u) >= 0 && u <= max) \
return (type) u; \
return (type) -1; \
} \
struct __useless_struct_to_allow_trailing_semicolon__