| // errorcheck | 
 |  | 
 | // Copyright 2012 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. | 
 |  | 
 | // Issue 3890: missing detection of init loop involving | 
 | // method calls in function bodies. | 
 |  | 
 | package flag | 
 |  | 
 | var commandLine = NewFlagSet() // ERROR "loop|depends upon itself" | 
 |  | 
 | type FlagSet struct { | 
 | } | 
 |  | 
 | func (f *FlagSet) failf(format string, a ...interface{}) { | 
 | 	f.usage() | 
 | } | 
 |  | 
 | func (f *FlagSet) usage() { | 
 | 	if f == commandLine { | 
 | 		panic(3) | 
 | 	} | 
 | } | 
 |  | 
 | func NewFlagSet() *FlagSet { | 
 | 	f := &FlagSet{} | 
 | 	f.setErrorHandling(true) | 
 | 	return f | 
 | } | 
 |  | 
 | func (f *FlagSet) setErrorHandling(b bool) { | 
 | 	f.failf("DIE") | 
 | } |