1 // Copyright 2013 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // This file contains tests for the shadowed variable checker. 6 // Some of these errors are caught by the compiler (shadowed return parameters for example) 7 // but are nonetheless useful tests. 8 9 package testdata 10 11 import "os" 12 13 func ShadowRead(f *os.File, buf []byte) (err error) { 14 var x int 15 if f != nil { 16 err := 3 // OK - different type. 17 _ = err 18 } 19 if f != nil { 20 _, err := f.Read(buf) // ERROR "declaration of .err. shadows declaration at testdata/shadow.go:13" 21 if err != nil { 22 return err 23 } 24 i := 3 // OK 25 _ = i 26 } 27 if f != nil { 28 x := one() // ERROR "declaration of .x. shadows declaration at testdata/shadow.go:14" 29 var _, err = f.Read(buf) // ERROR "declaration of .err. shadows declaration at testdata/shadow.go:13" 30 if x == 1 && err != nil { 31 return err 32 } 33 } 34 for i := 0; i < 10; i++ { 35 i := i // OK: obviously intentional idiomatic redeclaration 36 go func() { 37 println(i) 38 }() 39 } 40 var shadowTemp interface{} 41 switch shadowTemp := shadowTemp.(type) { // OK: obviously intentional idiomatic redeclaration 42 case int: 43 println("OK") 44 _ = shadowTemp 45 } 46 if shadowTemp := shadowTemp; true { // OK: obviously intentional idiomatic redeclaration 47 var f *os.File // OK because f is not mentioned later in the function. 48 // The declaration of x is a shadow because x is mentioned below. 49 var x int // ERROR "declaration of .x. shadows declaration at testdata/shadow.go:14" 50 _, _, _ = x, f, shadowTemp 51 } 52 // Use a couple of variables to trigger shadowing errors. 53 _, _ = err, x 54 return 55 } 56 57 func one() int { 58 return 1 59 } 60
