1
0
mirror of https://github.com/golang/go synced 2024-11-05 21:36:12 -07:00
go/cmd/vet/testdata/copylock.go
Josh Bleecher Snyder 866b24e166 cmd/vet: check for sync types being copied during function calls
Using a type containing a sync type directly
in a function call (whether as a receiver,
a param, or a return value) is an easy way
to accidentally copy a lock or other sync primitive.
Check for it.

The test as implemented does not provide 100%
coverage; see the discussion near the bottom of
testdata/copylock.go for shortcomings.

Fixes golang/go#6729.

R=adg, r, dsymonds
CC=golang-dev
https://golang.org/cl/23420043
2013-12-09 20:14:28 -08:00

90 lines
2.5 KiB
Go

// 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.
package testdata
import "sync"
func OkFunc(*sync.Mutex) {}
func BadFunc(sync.Mutex) {} // ERROR "BadFunc passes Lock by value: sync.Mutex"
func OkRet() *sync.Mutex {}
func BadRet() sync.Mutex {} // ERROR "BadRet returns Lock by value: sync.Mutex"
type EmbeddedRWMutex struct {
sync.RWMutex
}
func (*EmbeddedRWMutex) OkMeth() {}
func (EmbeddedRWMutex) BadMeth() {} // ERROR "BadMeth passes Lock by value: testdata.EmbeddedRWMutex"
func OkFunc(e *EmbeddedRWMutex) {}
func BadFunc(EmbeddedRWMutex) {} // ERROR "BadFunc passes Lock by value: testdata.EmbeddedRWMutex"
func OkRet() *EmbeddedRWMutex {}
func BadRet() EmbeddedRWMutex {} // ERROR "BadRet returns Lock by value: testdata.EmbeddedRWMutex"
type FieldMutex struct {
s sync.Mutex
}
func (*FieldMutex) OkMeth() {}
func (FieldMutex) BadMeth() {} // ERROR "BadMeth passes Lock by value: testdata.FieldMutex contains sync.Mutex"
func OkFunc(*FieldMutex) {}
func BadFunc(FieldMutex, int) {} // ERROR "BadFunc passes Lock by value: testdata.FieldMutex contains sync.Mutex"
type L0 struct {
L1
}
type L1 struct {
l L2
}
type L2 struct {
sync.Mutex
}
func (*L0) Ok() {}
func (L0) Bad() {} // ERROR "Bad passes Lock by value: testdata.L0 contains testdata.L1 contains testdata.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) {} // ERROR "Bad passes Lock by value: testdata.CustomLock"
// 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() {} // ERROR "Bad passes Lock by value: testdata.LocalOnce contains sync.Mutex"
// 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 :(