// Testing the virtual cast, as part of strict inheritance.

/* IMPORTANT: This test does not repersent the final feature set.
 * We are missing a number of important aspects such as:
 * + vtable type generation.
 * + vtable instance generation, that might use different resolution rules.
 * + Virtual syntax to force said generation on structures and traits.
 * + Trait references/pointers that do the virtual_table lookup.
 */

#include <stdlib.hfa>
#include <assert.h>



// Hand defined alpha virtual type:
struct __cfatid_struct_alpha {
	__cfavir_type_info parent;
};

__attribute__(( cfa_linkonce ))
struct __cfatid_struct_alpha __cfatid_alpha = {
	(__cfavir_type_info *)0,
};

struct alpha_vtable {
	struct __cfatid_struct_alpha const * const __cfavir_typeid;
	char (*code)(void);
};

struct alpha {
	alpha_vtable const * virtual_table;
};

char ret_a(void) {
	return 'a';
}



// Hand defined beta virtual type:
struct __cfatid_struct_beta {
	__cfatid_struct_alpha const * parent;
};

__attribute__(( section(".gnu.linkonce.__cfatid_beta") ))
struct __cfatid_struct_beta __cfatid_beta = {
	&__cfatid_alpha,
};

struct beta_vtable {
	struct __cfatid_struct_beta const * const __cfavir_typeid;
	char (*code)(void);
};

struct beta {
	beta_vtable const * virtual_table;
};

char ret_b(void) {
	return 'b';
}



// Hand defined gamma virtual type:
struct __cfatid_struct_gamma {
	__cfatid_struct_beta const * parent;
};

__attribute__(( section(".gnu.linkonce.__cfatid_gamma") ))
struct __cfatid_struct_gamma __cfatid_gamma = {
	&__cfatid_beta,
};

struct gamma_vtable {
	struct __cfatid_struct_gamma const * const __cfavir_typeid;
	char (*code)(void);
};

struct gamma {
	gamma_vtable const * virtual_table;
};

char ret_g(void) {
	return 'g';
}


extern "C" {
	alpha_vtable _alpha_vtable_instance = { &__cfatid_alpha, ret_a };
	beta_vtable _beta_vtable_instance = { &__cfatid_beta, ret_b };
	gamma_vtable _gamma_vtable_instance = { &__cfatid_gamma, ret_g };
}

int main (int argc, char * argv[]) {

	gamma * tri = malloc(); tri->virtual_table = &_gamma_vtable_instance;
	beta * mid = (virtual beta *)tri;
	assert( 'g' == mid->virtual_table->code() );

	alpha * top = malloc(); top->virtual_table = &_alpha_vtable_instance;
	mid = (virtual beta *)top;
	assert( ! mid );

	free(tri);
	free(top);
	printf( "done\n" );				// non-empty .expect file
}