From 3c7c11e55bdc9f766dff27d77ddad4a440f6b7c0 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Sat, 9 Oct 2021 08:32:37 +0800
Subject: [PATCH] cgen: fix sumtype with none type (fix #12101) (#12102)

---
 vlib/v/gen/c/cgen.v                         | 6 ++++++
 vlib/v/tests/sum_type_with_none_type_test.v | 5 +++++
 2 files changed, 11 insertions(+)
 create mode 100644 vlib/v/tests/sum_type_with_none_type_test.v

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index d06ae08cb0..c7210c74dd 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -6038,6 +6038,12 @@ fn (mut g Gen) write_types(types []ast.TypeSymbol) {
 		if typ.name.starts_with('C.') {
 			continue
 		}
+		if typ.kind == .none_ {
+			g.type_definitions.writeln('struct none {')
+			g.type_definitions.writeln('\tEMPTY_STRUCT_DECLARATION;')
+			g.type_definitions.writeln('};')
+			g.typedefs2.writeln('typedef struct none none;')
+		}
 		// sym := g.table.get_type_symbol(typ)
 		mut name := typ.cname
 		match mut typ.info {
diff --git a/vlib/v/tests/sum_type_with_none_type_test.v b/vlib/v/tests/sum_type_with_none_type_test.v
new file mode 100644
index 0000000000..148381fffa
--- /dev/null
+++ b/vlib/v/tests/sum_type_with_none_type_test.v
@@ -0,0 +1,5 @@
+type MapValue = int | none
+
+fn test_sum_type_with_none_type() {
+	assert true
+}