Fix #2160 (deep subtyping through using of _)

This commit is contained in:
gingerBill
2022-11-01 13:14:20 +00:00
parent 411c0add3b
commit 2b7ca2bdd6
2 changed files with 63 additions and 26 deletions

View File

@@ -1952,34 +1952,33 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
Type *dt = t;
GB_ASSERT(is_type_struct(st) || is_type_raw_union(st));
String field_name = lookup_subtype_polymorphic_field(t, src_type);
if (field_name.len > 0) {
// NOTE(bill): It can be casted
Selection sel = lookup_field(st, field_name, false, true);
if (sel.entity != nullptr) {
if (st_is_ptr) {
lbValue res = lb_emit_deep_field_gep(p, value, sel);
Type *rt = res.type;
if (!are_types_identical(rt, dt) && are_types_identical(type_deref(rt), dt)) {
res = lb_emit_load(p, res);
}
return res;
} else {
if (is_type_pointer(value.type)) {
Type *rt = value.type;
if (!are_types_identical(rt, dt) && are_types_identical(type_deref(rt), dt)) {
value = lb_emit_load(p, value);
} else {
value = lb_emit_deep_field_gep(p, value, sel);
return lb_emit_load(p, value);
}
}
return lb_emit_deep_field_ev(p, value, sel);
Selection sel = {};
sel.index.allocator = heap_allocator();
defer (array_free(&sel.index));
if (lookup_subtype_polymorphic_selection(t, src_type, &sel)) {
if (sel.entity == nullptr) {
GB_PANIC("invalid subtype cast %s -> ", type_to_string(src_type), type_to_string(t));
}
if (st_is_ptr) {
lbValue res = lb_emit_deep_field_gep(p, value, sel);
Type *rt = res.type;
if (!are_types_identical(rt, dt) && are_types_identical(type_deref(rt), dt)) {
res = lb_emit_load(p, res);
}
return res;
} else {
GB_PANIC("invalid subtype cast %s.%.*s", type_to_string(src_type), LIT(field_name));
if (is_type_pointer(value.type)) {
Type *rt = value.type;
if (!are_types_identical(rt, dt) && are_types_identical(type_deref(rt), dt)) {
value = lb_emit_load(p, value);
} else {
value = lb_emit_deep_field_gep(p, value, sel);
return lb_emit_load(p, value);
}
}
return lb_emit_deep_field_ev(p, value, sel);
}
}
}

View File

@@ -2526,6 +2526,44 @@ String lookup_subtype_polymorphic_field(Type *dst, Type *src) {
return str_lit("");
}
bool lookup_subtype_polymorphic_selection(Type *dst, Type *src, Selection *sel) {
Type *prev_src = src;
// Type *prev_dst = dst;
src = base_type(type_deref(src));
// dst = base_type(type_deref(dst));
bool src_is_ptr = src != prev_src;
// bool dst_is_ptr = dst != prev_dst;
GB_ASSERT(is_type_struct(src) || is_type_union(src));
for_array(i, src->Struct.fields) {
Entity *f = src->Struct.fields[i];
if (f->kind == Entity_Variable && f->flags & EntityFlags_IsSubtype) {
if (are_types_identical(dst, f->type)) {
array_add(&sel->index, cast(i32)i);
sel->entity = f;
return true;
}
if (src_is_ptr && is_type_pointer(dst)) {
if (are_types_identical(type_deref(dst), f->type)) {
array_add(&sel->index, cast(i32)i);
sel->indirect = true;
sel->entity = f;
return true;
}
}
if ((f->flags & EntityFlag_Using) != 0 && is_type_struct(f->type)) {
String name = lookup_subtype_polymorphic_field(dst, f->type);
if (name.len > 0) {
array_add(&sel->index, cast(i32)i);
return lookup_subtype_polymorphic_selection(dst, f->type, sel);
}
}
}
}
return false;
}
Type *strip_type_aliasing(Type *x) {