parser: disallow option alias with option parent type (#20769)

vlang · Feb 10, 2024 · 4d01a77 · 4d01a77
1 parent 99579ac
commit 4d01a77
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Showing 3 changed files with 18 additions and 0 deletions.
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
@@ -534,6 +534,13 @@ 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) {
+			alias_type_str := p.table.type_to_str(typ)
+			parent_type_str := p.table.type_to_str(sym.info.parent_type)
+			p.error_with_pos('cannot use double options like `?${parent_type_str}`, `?${alias_type_str}` is a double option. use `${alias_type_str}` instead',
+				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: cannot use double options like `??bool`, `?Foo` is a double option. use `Foo` instead
+    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
+}