From 5dae5b2a92ecf7e7c7187fa0900813479e796304 Mon Sep 17 00:00:00 2001
From: shove <shove@163.com>
Date: Sat, 1 Oct 2022 19:40:55 +0800
Subject: [PATCH] checker: fix references for alias type, that could still be
 uninitalized (fix #15935) (#15940)

---
 vlib/v/checker/struct.v                       | 13 +++++++++
 .../struct_ref_fields_uninitialized_err.out   | 29 ++++++++++++-------
 .../struct_ref_fields_uninitialized_err.vv    |  5 +++-
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
index 5fe5689589..52c371a7ee 100644
--- a/vlib/v/checker/struct.v
+++ b/vlib/v/checker/struct.v
@@ -522,6 +522,12 @@ pub fn (mut c Checker) struct_init(mut node ast.StructInit) ast.Type {
 				if sym.kind == .struct_ && !(sym.info as ast.Struct).is_typedef {
 					c.check_ref_fields_initialized(sym, mut checked_structs, '${type_sym.name}.$field.name',
 						node)
+				} else if sym.kind == .alias {
+					parent_sym := c.table.sym((sym.info as ast.Alias).parent_type)
+					if parent_sym.kind == .struct_ {
+						c.check_ref_fields_initialized(parent_sym, mut checked_structs,
+							'${type_sym.name}.$field.name', node)
+					}
 				}
 				// Do not allow empty uninitialized interfaces
 				mut has_noinit := false
@@ -608,6 +614,13 @@ fn (mut c Checker) check_ref_fields_initialized(struct_sym &ast.TypeSymbol, mut
 			checked_structs << field.typ
 			c.check_ref_fields_initialized(sym, mut checked_structs, '${linked_name}.$field.name',
 				node)
+		} else if sym.kind == .alias {
+			parent_sym := c.table.sym((sym.info as ast.Alias).parent_type)
+			if parent_sym.kind == .struct_ {
+				checked_structs << field.typ
+				c.check_ref_fields_initialized(parent_sym, mut checked_structs, '${linked_name}.$field.name',
+					node)
+			}
 		}
 	}
 }
diff --git a/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.out b/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.out
index 70e375adcc..e50eead98a 100644
--- a/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.out
+++ b/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.out
@@ -1,13 +1,20 @@
-vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv:22:7: warning: reference field `Outer.c.b` must be initialized
-   20 | 
-   21 | fn main() {
-   22 |     _ := Outer{}
+vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv:25:7: warning: reference field `Outer.c1.b` must be initialized
+   23 | 
+   24 | fn main() {
+   25 |     _ := Outer{}
       |          ~~~~~~~
-   23 |     _ := Struct{}
-   24 | }
-vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv:23:7: warning: reference field `Struct.ref2` must be initialized
-   21 | fn main() {
-   22 |     _ := Outer{}
-   23 |     _ := Struct{}
+   26 |     _ := Struct{}
+   27 | }
+vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv:25:7: warning: reference field `Outer.c2.b` must be initialized
+   23 | 
+   24 | fn main() {
+   25 |     _ := Outer{}
+      |          ~~~~~~~
+   26 |     _ := Struct{}
+   27 | }
+vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv:26:7: warning: reference field `Struct.ref2` must be initialized
+   24 | fn main() {
+   25 |     _ := Outer{}
+   26 |     _ := Struct{}
       |          ~~~~~~~~
-   24 | }
+   27 | }
diff --git a/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv b/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv
index b8f08a3927..5ef20f99cb 100644
--- a/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv
+++ b/vlib/v/checker/tests/struct_ref_fields_uninitialized_err.vv
@@ -3,8 +3,11 @@ struct ContainsRef {
 	b &int
 }
 
+type TypeForContainsRef = ContainsRef
+
 struct Outer {
-	c ContainsRef
+	c1 ContainsRef
+	c2 TypeForContainsRef
 }
 
 struct Ref {}