go source for verification 2026-05-22

test/funcdup.go

@@ -0,0 +1,27 @@
+// errorcheck
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+type T interface {
+	F1(i int) (i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+	F2(i, i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+	F3() (i, i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+}
+
+type T1 func(i, i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+type T2 func(i int) (i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+type T3 func() (i, i int) // ERROR "duplicate argument i|redefinition|previous|redeclared"
+
+type R struct{}
+
+func (i *R) F1(i int)         {} // ERROR "duplicate argument i|redefinition|previous|redeclared"
+func (i *R) F2() (i int)      {return 0} // ERROR "duplicate argument i|redefinition|previous|redeclared"
+func (i *R) F3(j int) (j int) {return 0} // ERROR "duplicate argument j|redefinition|previous|redeclared"
+
+func F1(i, i int)      {} // ERROR "duplicate argument i|redefinition|previous|redeclared"
+func F2(i int) (i int) {return 0} // ERROR "duplicate argument i|redefinition|previous|redeclared"
+func F3() (i, i int)   {return 0, 0} // ERROR "duplicate argument i|redefinition|previous|redeclared"