From 770cff8b918f5754062aa991cfdd19988ce4a788 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Wed, 6 May 2020 15:24:12 +0300
Subject: [PATCH] compiler: allow to use `return` with no arguments

---
 pkg/compiler/func_scope.go         |  8 +++++---
 pkg/compiler/function_call_test.go | 11 +++++++++--
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/pkg/compiler/func_scope.go b/pkg/compiler/func_scope.go
index d4a0ca862..de9d039e7 100644
--- a/pkg/compiler/func_scope.go
+++ b/pkg/compiler/func_scope.go
@@ -65,9 +65,11 @@ func (c *funcScope) analyzeVoidCalls(node ast.Node) bool {
 			}
 		}
 	case *ast.ReturnStmt:
-		switch n.Results[0].(type) {
-		case *ast.CallExpr:
-			return false
+		if len(n.Results) > 0 {
+			switch n.Results[0].(type) {
+			case *ast.CallExpr:
+				return false
+			}
 		}
 	case *ast.BinaryExpr:
 		return false
diff --git a/pkg/compiler/function_call_test.go b/pkg/compiler/function_call_test.go
index 7c1f22367..179e0d136 100644
--- a/pkg/compiler/function_call_test.go
+++ b/pkg/compiler/function_call_test.go
@@ -121,7 +121,14 @@ func TestFunctionWithVoidReturn(t *testing.T) {
 			return x + y
 		}
 
-		func getSomeInteger() { }
+		func getSomeInteger() { %s }
 	`
-	eval(t, src, big.NewInt(6))
+	t.Run("EmptyBody", func(t *testing.T) {
+		src := fmt.Sprintf(src, "")
+		eval(t, src, big.NewInt(6))
+	})
+	t.Run("SingleReturn", func(t *testing.T) {
+		src := fmt.Sprintf(src, "return")
+		eval(t, src, big.NewInt(6))
+	})
 }