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implement checkcast

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This commit is contained in:
Zack Buhman 2024-12-30 10:54:28 -06:00
parent 40ab3ddfd3
commit 49cc665f76
2 changed files with 88 additions and 25 deletions
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87
c/execute.c
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@ -179,7 +179,41 @@ void op_castore(struct vm * vm)
void op_checkcast(struct vm * vm, uint32_t index)
{
assert(!"op_checkcast");
int32_t * objectref = (int32_t *)operand_stack_peek_u32(vm->current_frame, 1);
if (objectref == nullptr) {
return;
}
struct class_entry * index_class_entry =
class_resolver_lookup_class_from_class_index(vm->class_hash_table.length,
vm->class_hash_table.entry,
vm->current_frame->class_entry,
index);
struct class_entry * class_entry = (struct class_entry *)objectref[0];
while (true) {
assert(class_entry != nullptr);
if (class_entry == index_class_entry) {
return;
}
if (class_entry->class_file->super_class == 0) {
break;
}
struct constant * class_constant = &class_entry->class_file->constant_pool[class_entry->class_file->super_class - 1];
assert(class_constant->tag == CONSTANT_Class);
struct constant * class_name_constant = &class_entry->class_file->constant_pool[class_constant->class.name_index - 1];
assert(class_name_constant->tag == CONSTANT_Utf8);
print_utf8_string(class_name_constant);
debugf("\n");
// superclass lookup
class_entry = class_resolver_lookup_class_from_class_index(vm->class_hash_table.length,
vm->class_hash_table.entry,
class_entry,
class_entry->class_file->super_class);
}
assert(!"ClassCastException");
}
void op_d2f(struct vm * vm)
@ -1102,32 +1136,35 @@ void op_instanceof(struct vm * vm, uint32_t index)
assert(index_class_entry != nullptr);
int32_t * objectref = (int32_t *)operand_stack_pop_u32(vm->current_frame);
if (objectref == nullptr) {
operand_stack_push_u32(vm->current_frame, (uint32_t)false);
return;
}
bool value = false;
if (objectref != nullptr) {
struct class_entry * class_entry = (struct class_entry *)objectref[0];
while (true) {
assert(class_entry != nullptr);
if (class_entry == index_class_entry) {
value = true;
break;
}
if (class_entry->class_file->super_class == 0) {
break;
}
struct constant * class_constant = &class_entry->class_file->constant_pool[class_entry->class_file->super_class - 1];
assert(class_constant->tag == CONSTANT_Class);
struct constant * class_name_constant = &class_entry->class_file->constant_pool[class_constant->class.name_index - 1];
assert(class_name_constant->tag == CONSTANT_Utf8);
print_utf8_string(class_name_constant);
debugf("\n");
// superclass lookup
class_entry = class_resolver_lookup_class_from_class_index(vm->class_hash_table.length,
vm->class_hash_table.entry,
class_entry,
class_entry->class_file->super_class);
struct class_entry * class_entry = (struct class_entry *)objectref[0];
while (true) {
assert(class_entry != nullptr);
if (class_entry == index_class_entry) {
value = true;
break;
}
if (class_entry->class_file->super_class == 0) {
break;
}
struct constant * class_constant = &class_entry->class_file->constant_pool[class_entry->class_file->super_class - 1];
assert(class_constant->tag == CONSTANT_Class);
struct constant * class_name_constant = &class_entry->class_file->constant_pool[class_constant->class.name_index - 1];
assert(class_name_constant->tag == CONSTANT_Utf8);
print_utf8_string(class_name_constant);
debugf("\n");
// superclass lookup
class_entry = class_resolver_lookup_class_from_class_index(vm->class_hash_table.length,
vm->class_hash_table.entry,
class_entry,
class_entry->class_file->super_class);
}
operand_stack_push_u32(vm->current_frame, (uint32_t)value);
}

26
p/CheckCastTest.java Normal file
View File

@ -0,0 +1,26 @@
package p;
class Animal {
}
class Cat extends Animal {
}
class Dog extends Animal {
}
class CheckCastTest {
public static boolean test() {
Dog d = new Dog();
Cat c = new Cat();
Animal da = d;
Animal ca = c;
Cat cc = (Cat)da;
//Cat cc = (Cat)ca;
return cc instanceof Cat;
}
public static void main() {
test();
}
}