Custom Ruby type check to fix problem with JRuby and TruffleRuby

extconf.rb

# frozen_string_literal: true

require 'mkmf'

dir_config('test')

create_header
create_makefile('test')

test.c

#if defined(__cplusplus)
extern "C" {
#endif

#include <ruby.h>

#define ARRAY_SIZE(array) (int)(sizeof(array) / sizeof((array)[0]))
#define CLASS_NAME(o) (NIL_P((o)) ? "nil" : rb_obj_classname((o)))
#define error(t) errors[(t)]

enum error {
	E_UNKNOWN = 0,
	E_ARGUMENT_TYPE_INVALID,
	E_ARGUMENT_TYPE_UNKNOWN
};
	
static const char *errors[] = {
	[E_ARGUMENT_TYPE_INVALID] = "wrong argument type %s (expected %s)",
	[E_ARGUMENT_TYPE_UNKNOWN] = "unknown type 0x%x (0x%x given)",
	NULL
};
	
static const char *ruby_types[] = {
	"", /* Not an object */
	[T_OBJECT]	= "Object",
	[T_CLASS]	= "Class",
	[T_MODULE]	= "Module",
	[T_FLOAT]	= "Float",
	[T_STRING]	= "String",
	[T_REGEXP]	= "Regexp",
	[T_ARRAY]	= "Array",
	[T_HASH]	= "Hash",
	[T_STRUCT]	= "Struct",
	[T_BIGNUM]	= "Integer",
	[T_FILE]	= "File",
	"", /* Internal use */
	[T_MATCH]	= "MatchData",
	[T_COMPLEX]	= "Complex",
	[T_RATIONAL]	= "Rational",
	"", /* Internal use */
	[T_NIL]		= "nil",
	[T_TRUE]	= "true",
	[T_FALSE]	= "false",
	[T_SYMBOL]	= "Symbol",
	[T_FIXNUM]	= "Integer",
	"", /* Internal use */
	NULL
};

static const char *
ruby_type_name(int type)
{
	const char *name;

	if (type >= ARRAY_SIZE(ruby_types))
		return NULL;

	name = ruby_types[type];
	if (name)
		return name;

	return NULL;
}

static const char *
ruby_class_name(VALUE object)
{
	const char *name = NULL;

	if (NIL_P(object))
		name = "nil";
	else if (RB_TYPE_P(object, T_TRUE))
		name = "true";
	else if (RB_TYPE_P(object, T_FALSE))
		name = "false";
	else
		name = CLASS_NAME(object);

	return name;
}

void
check_ruby_type(VALUE object, int type)
{
	const char *name;
	int object_type = TYPE(object);

	if (object == Qundef)
		rb_bug("invalid type leaked to the Ruby space");

	if (object_type > T_MASK || object_type == T_DATA)
		goto error;

	if (object_type == type)
		return;

	name = ruby_type_name(type);
	if (name)
		rb_raise(rb_eTypeError, error(E_ARGUMENT_TYPE_INVALID),
			 ruby_class_name(object),
			 name);
error:
	rb_raise(rb_eTypeError, error(E_ARGUMENT_TYPE_UNKNOWN),
		 object_type,
		 type);
}
	
void check_type(VALUE object, int type)
{
	const char *name;
	int object_type = TYPE(object);

	if (object_type == type)
		return;

	name = ruby_type_name(type);
	if (name)
		rb_raise(rb_eTypeError, "wrong argument type %s (expected %s)",
			 ruby_class_name(object),
			 name);

	rb_raise(rb_eTypeError, "unknown type 0x%x (0x%x given)",
		 object_type,
		 type);
}

void
Init_test(void)
{
	check_type(rb_cArray, T_STRING);
	/* check_type(rb_cArray, 123); */
	/* check_type(rb_cArray, rb_str_new2("")); */
}

#if defined(__cplusplus)
}
#endif