// 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.
// This file contains tests for the shadowed variable checker.
// Some of these errors are caught by the compiler (shadowed return parameters for example)
// but are nonetheless useful tests.
package a
import "os"
func ShadowRead(f *os.File, buf []byte) (err error) {
var x int
if f != nil {
err := 3 // OK - different type.
_ = err
}
if f != nil {
_, err := f.Read(buf) // want "declaration of .err. shadows declaration at line 13"
if err != nil {
return err
}
i := 3 // OK
_ = i
}
if f != nil {
x := one() // want "declaration of .x. shadows declaration at line 14"
var _, err = f.Read(buf) // want "declaration of .err. shadows declaration at line 13"
if x == 1 && err != nil {
return err
}
}
for i := 0; i < 10; i++ {
i := i // OK: obviously intentional idiomatic redeclaration
go func() {
println(i)
}()
}
var shadowTemp interface{}
switch shadowTemp := shadowTemp.(type) { // OK: obviously intentional idiomatic redeclaration
case int:
println("OK")
_ = shadowTemp
}
if shadowTemp := shadowTemp; true { // OK: obviously intentional idiomatic redeclaration
var f *os.File // OK because f is not mentioned later in the function.
// The declaration of x is a shadow because x is mentioned below.
var x int // want "declaration of .x. shadows declaration at line 14"
_, _, _ = x, f, shadowTemp
}
// Use a couple of variables to trigger shadowing errors.
_, _ = err, x
return
}
func one() int {
return 1
}
// Must not complain with an internal error for the
// implicitly declared type switch variable v.
func issue26725(x interface{}) int {
switch v := x.(type) {
case int, int32:
if v, ok := x.(int); ok {
return v
}
case int64:
return int(v)
}
return 0
}
// Verify that implicitly declared variables from
// type switches are considered in shadowing analysis.
func shadowTypeSwitch(a interface{}) {
switch t := a.(type) {
case int:
{
t := 0 // want "declaration of .t. shadows declaration at line 78"
_ = t
}
_ = t
case uint:
{
t := uint(0) // OK because t is not mentioned later in this function
_ = t
}
}
}
func shadowBlock() {
var a int
{
var a = 3 // want "declaration of .a. shadows declaration at line 94"
_ = a
}
_ = a
}