parser: disallow option alias with option parent type

Delta456 · Feb 9, 2024 · c007766 · c007766
1 parent 1544546
commit c007766
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Showing 3 changed files with 16 additions and 0 deletions.
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
@@ -534,6 +534,11 @@ fn (mut p Parser) parse_type() ast.Type {
 		if is_option && sym.info is ast.SumType && sym.info.is_anon {
 			p.error_with_pos('an inline sum type cannot be an Option', option_pos.extend(p.prev_tok.pos()))
 		}
+
+		if is_option && sym.info is ast.Alias && sym.info.parent_type.has_flag(.option) {
+			p.error_with_pos('alias type cannot be option as parent type is already option',
+				option_pos.extend(p.prev_tok.pos()))
+		}
 	}
 	if is_option {
 		typ = typ.set_flag(.option)

diff --git a/vlib/v/parser/tests/option_alias_option_type_err.out b/vlib/v/parser/tests/option_alias_option_type_err.out
@@ -0,0 +1,6 @@
+vlib/v/parser/tests/option_alias_option_type_err.vv:4:11: error: alias type cannot be option as parent type is already option
+    2 | 
+    3 | struct Bar {
+    4 |         a ?Foo
+      |           ~~~~
+    5 | }
diff --git a/vlib/v/parser/tests/option_alias_option_type_err.vv b/vlib/v/parser/tests/option_alias_option_type_err.vv
@@ -0,0 +1,5 @@
+type Foo = ?bool
+
+struct Bar {
+        a ?Foo
+}