cgen: fix sumtype option unwrapping (fix #24746) (#24770)

felipensp · web-flow · commit 21cc3c31fe8b · 2025-06-21T19:57:18.000+03:00
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
@@ -5287,8 +5287,9 @@ fn (mut g Gen) ident(node ast.Ident) {
 				obj_sym := g.table.sym(g.unwrap_generic(node.obj.typ))
 				if !prevent_sum_type_unwrapping_once {
 					nested_unwrap := node.obj.smartcasts.len > 1
-					if is_option && nested_unwrap && obj_sym.kind == .sum_type {
-						g.write('*(')
+					unwrap_sumtype := is_option && nested_unwrap && obj_sym.kind == .sum_type
+					if unwrap_sumtype {
+						g.write('(*(')
 					}
 					for i, typ in node.obj.smartcasts {
 						is_option_unwrap := i == 0 && is_option
@@ -5379,6 +5380,9 @@ fn (mut g Gen) ident(node ast.Ident) {
 									&& obj_sym.kind in [.sum_type, .interface] {
 									g.write('${dot}_${cast_sym.cname}')
 								}
+								if i != 0 && unwrap_sumtype {
+									g.write(')')
+								}
 							}
 						}
 						if i == 0 && node.obj.ct_type_var != .smartcast && node.obj.is_unwrapped {
diff --git a/vlib/v/tests/options/option_sumtype_unwrap_test.v b/vlib/v/tests/options/option_sumtype_unwrap_test.v
@@ -0,0 +1,40 @@
+type TxPayload = Can | u8
+
+enum Tx {
+	empty
+	data
+	can
+}
+
+fn (tx Tx) frame_bytes(payload ?TxPayload) ![]u8 {
+	match tx {
+		.empty {
+			return [u8(tx)]
+		}
+		.data {
+			if payload != none {
+				if payload is u8 {
+					return [u8(tx), payload]
+				}
+			}
+			return error('Invalid data')
+		}
+		.can {
+			if payload != none {
+				if payload is Can {
+					return [u8(tx), payload.net]
+				}
+			}
+			return error('Invalid can')
+		}
+	}
+}
+
+struct Can {
+	net u8
+}
+
+fn test_main() {
+	assert Tx.empty.frame_bytes(none)! == [u8(0)]
+	assert Tx.data.frame_bytes(u8(123))! == [u8(1), 123]
+}

Original file line number	Diff line number	Diff line change
`@@ -5287,8 +5287,9 @@ fn (mut g Gen) ident(node ast.Ident) {`
`5287`	`5287`	`obj_sym := g.table.sym(g.unwrap_generic(node.obj.typ))`
`5288`	`5288`	`if !prevent_sum_type_unwrapping_once {`
`5289`	`5289`	`nested_unwrap := node.obj.smartcasts.len > 1`
`5290`		`- if is_option && nested_unwrap && obj_sym.kind == .sum_type {`
`5291`		`- g.write('*(')`
	`5290`	`+ unwrap_sumtype := is_option && nested_unwrap && obj_sym.kind == .sum_type`
	`5291`	`+ if unwrap_sumtype {`
	`5292`	`+ g.write('(*(')`
`5292`	`5293`	`}`
`5293`	`5294`	`for i, typ in node.obj.smartcasts {`
`5294`	`5295`	`is_option_unwrap := i == 0 && is_option`
`@@ -5379,6 +5380,9 @@ fn (mut g Gen) ident(node ast.Ident) {`
`5379`	`5380`	`&& obj_sym.kind in [.sum_type, .interface] {`
`5380`	`5381`	`g.write('${dot}_${cast_sym.cname}')`
`5381`	`5382`	`}`
	`5383`	`+ if i != 0 && unwrap_sumtype {`
	`5384`	`+ g.write(')')`
	`5385`	`+ }`
`5382`	`5386`	`}`
`5383`	`5387`	`}`
`5384`	`5388`	`if i == 0 && node.obj.ct_type_var != .smartcast && node.obj.is_unwrapped {`