Add new argument type CRYPT_ARG_ALIAS.

It can be used to easily define option
aliases for command line utilities.

src/cryptsetup.c

@@ -3105,6 +3105,15 @@ static void basic_options_cb(poptContext popt_context,
 	}
 }
 
+static void cryptsetup_init_arg_aliases(void)
+{
+	unsigned i;
+
+	for (i = 1; i < ARRAY_SIZE(tool_core_args); i++)
+		if (tool_core_args[i].type == CRYPT_ARG_ALIAS)
+			ARG_INIT_ALIAS(i);
+}
+
 int main(int argc, const char **argv)
 {
 	static struct poptOption popt_help_options[] = {
@@ -3131,6 +3140,9 @@ int main(int argc, const char **argv)
 	const char *aname, *error_message;
 	int r;
 
+	/* initialize aliases */
+	cryptsetup_init_arg_aliases();
+
 	crypt_set_log_callback(NULL, tool_log, &log_parms);
 
 	setlocale(LC_ALL, "");

src/cryptsetup.h

@@ -132,7 +132,8 @@ typedef enum {
 	CRYPT_ARG_INT32,
 	CRYPT_ARG_UINT32,
 	CRYPT_ARG_INT64,
-	CRYPT_ARG_UINT64
+	CRYPT_ARG_UINT64,
+	CRYPT_ARG_ALIAS
 } crypt_arg_type_info;
 
 struct tools_arg {
@@ -145,6 +146,10 @@ struct tools_arg {
 		uint32_t u32_value;
 		int32_t i32_value;
 		int64_t i64_value;
+		union {
+			unsigned id;
+			struct tools_arg *ptr;
+		} o;
 	} u;
 	const char *actions_array[MAX_ACTIONS];
 };

src/utils_arg_macros.h

@@ -93,4 +93,11 @@ do { \
 	tool_core_args[(X)].set = true; \
 } while (0)
 
+
+#define ARG_INIT_ALIAS(X) \
+do { \
+	assert(tool_core_args[(X)].type == CRYPT_ARG_ALIAS); \
+	tool_core_args[(X)].u.o.ptr = &tool_core_args[tool_core_args[(X)].u.o.id]; \
+} while (0)
+
 #endif

src/utils_args.c

@@ -75,6 +75,9 @@ void tools_parse_arg_value(poptContext popt_context, crypt_arg_type_info type, s
 			arg->u.u64_value = ull;
 		}
 		break;
+	case CRYPT_ARG_ALIAS:
+		tools_parse_arg_value(popt_context, arg->u.o.ptr->type, arg->u.o.ptr, popt_arg, arg->u.o.id, needs_size_conv_fn);
+		break;
 	default:
 		/* this signals internal tools coding mistake */
 		abort();