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// 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 copylock checker's
// function declaration analysis.
package a
import "sync"
func OkFunc(*sync.Mutex) {}
func BadFunc(sync.Mutex) {} // want "BadFunc passes lock by value: sync.Mutex"
func BadFunc2(sync.Map) {} // want "BadFunc2 passes lock by value: sync.Map contains sync.Mutex"
func OkRet() *sync.Mutex {}
func BadRet() sync.Mutex {} // Don't warn about results
var (
OkClosure = func(*sync.Mutex) {}
BadClosure = func(sync.Mutex) {} // want "func passes lock by value: sync.Mutex"
BadClosure2 = func(sync.Map) {} // want "func passes lock by value: sync.Map contains sync.Mutex"
)
type EmbeddedRWMutex struct {
sync.RWMutex
}
func (*EmbeddedRWMutex) OkMeth() {}
func (EmbeddedRWMutex) BadMeth() {} // want "BadMeth passes lock by value: a.EmbeddedRWMutex"
func OkFunc(e *EmbeddedRWMutex) {}
func BadFunc(EmbeddedRWMutex) {} // want "BadFunc passes lock by value: a.EmbeddedRWMutex"
func OkRet() *EmbeddedRWMutex {}
func BadRet() EmbeddedRWMutex {} // Don't warn about results
type FieldMutex struct {
s sync.Mutex
}
func (*FieldMutex) OkMeth() {}
func (FieldMutex) BadMeth() {} // want "BadMeth passes lock by value: a.FieldMutex contains sync.Mutex"
func OkFunc(*FieldMutex) {}
func BadFunc(FieldMutex, int) {} // want "BadFunc passes lock by value: a.FieldMutex contains sync.Mutex"
type L0 struct {
L1
}
type L1 struct {
l L2
}
type L2 struct {
sync.Mutex
}
func (*L0) Ok() {}
func (L0) Bad() {} // want "Bad passes lock by value: a.L0 contains a.L1 contains a.L2"
type EmbeddedMutexPointer struct {
s *sync.Mutex // safe to copy this pointer
}
func (*EmbeddedMutexPointer) Ok() {}
func (EmbeddedMutexPointer) AlsoOk() {}
func StillOk(EmbeddedMutexPointer) {}
func LookinGood() EmbeddedMutexPointer {}
type EmbeddedLocker struct {
sync.Locker // safe to copy interface values
}
func (*EmbeddedLocker) Ok() {}
func (EmbeddedLocker) AlsoOk() {}
type CustomLock struct{}
func (*CustomLock) Lock() {}
func (*CustomLock) Unlock() {}
func Ok(*CustomLock) {}
func Bad(CustomLock) {} // want "Bad passes lock by value: a.CustomLock"
// Passing lock values into interface function arguments
func FuncCallInterfaceArg(f func(a int, b interface{})) {
var m sync.Mutex
var t struct{ lock sync.Mutex }
f(1, "foo")
f(2, &t)
f(3, &sync.Mutex{})
f(4, m) // want "call of f copies lock value: sync.Mutex"
f(5, t) // want "call of f copies lock value: struct.lock sync.Mutex. contains sync.Mutex"
var fntab []func(t)
fntab[0](t) // want "call of fntab.0. copies lock value: struct.lock sync.Mutex. contains sync.Mutex"
}
// Returning lock via interface value
func ReturnViaInterface(x int) (int, interface{}) {
var m sync.Mutex
var t struct{ lock sync.Mutex }
switch x % 4 {
case 0:
return 0, "qwe"
case 1:
return 1, &sync.Mutex{}
case 2:
return 2, m // want "return copies lock value: sync.Mutex"
default:
return 3, t // want "return copies lock value: struct.lock sync.Mutex. contains sync.Mutex"
}
}
// Some cases that we don't warn about.
func AcceptedCases() {
x := EmbeddedRwMutex{} // composite literal on RHS is OK (#16227)
x = BadRet() // function call on RHS is OK (#16227)
x = *OKRet() // indirection of function call on RHS is OK (#16227)
}
// TODO: Unfortunate cases
// Non-ideal error message:
// Since we're looking for Lock methods, sync.Once's underlying
// sync.Mutex gets called out, but without any reference to the sync.Once.
type LocalOnce sync.Once
func (LocalOnce) Bad() {} // want `Bad passes lock by value: a.LocalOnce contains sync.\b.*`
// False negative:
// LocalMutex doesn't have a Lock method.
// Nevertheless, it is probably a bad idea to pass it by value.
type LocalMutex sync.Mutex
func (LocalMutex) Bad() {} // WANTED: An error here :(
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