mirror of
https://github.com/golang/go
synced 2024-11-13 17:30:24 -07:00
fc0dc04095
Very few of the compiler regression tests include a comment saying waht they do. Many are obvious, some are anything but. I've started with a-c in the top directory. More will follow once we agree on the approach, correctness, and thoroughness here. zerodivide.go sneaked in too. R=rsc, r CC=golang-dev https://golang.org/cl/5656100
76 lines
1.8 KiB
Go
76 lines
1.8 KiB
Go
// errorcheck
|
|
|
|
// Copyright 2010 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.
|
|
|
|
// Verify that incorrect comparisons are detected.
|
|
// Does not compile.
|
|
|
|
package main
|
|
|
|
func use(bool) {}
|
|
|
|
type T1 *int
|
|
type T2 *int
|
|
|
|
type T3 struct{ z []int }
|
|
|
|
var t3 T3
|
|
|
|
type T4 struct { _ []int; a float64 }
|
|
|
|
var t4 T4
|
|
|
|
func main() {
|
|
// Arguments to comparison must be
|
|
// assignable one to the other (or vice versa)
|
|
// so chan int can be compared against
|
|
// directional channels but channel of different
|
|
// direction cannot be compared against each other.
|
|
var c1 chan<- int
|
|
var c2 <-chan int
|
|
var c3 chan int
|
|
|
|
use(c1 == c2) // ERROR "invalid operation|incompatible"
|
|
use(c2 == c1) // ERROR "invalid operation|incompatible"
|
|
use(c1 == c3)
|
|
use(c2 == c2)
|
|
use(c3 == c1)
|
|
use(c3 == c2)
|
|
|
|
// Same applies to named types.
|
|
var p1 T1
|
|
var p2 T2
|
|
var p3 *int
|
|
|
|
use(p1 == p2) // ERROR "invalid operation|incompatible"
|
|
use(p2 == p1) // ERROR "invalid operation|incompatible"
|
|
use(p1 == p3)
|
|
use(p2 == p2)
|
|
use(p3 == p1)
|
|
use(p3 == p2)
|
|
|
|
// Comparison of structs should have a good message
|
|
use(t3 == t3) // ERROR "struct|expected"
|
|
use(t4 == t4) // ok; the []int is a blank field
|
|
|
|
// Slices, functions, and maps too.
|
|
var x []int
|
|
var f func()
|
|
var m map[int]int
|
|
use(x == x) // ERROR "slice can only be compared to nil"
|
|
use(f == f) // ERROR "func can only be compared to nil"
|
|
use(m == m) // ERROR "map can only be compared to nil"
|
|
|
|
// Comparison with interface that cannot return true
|
|
// (would panic).
|
|
var i interface{}
|
|
use(i == x) // ERROR "invalid operation"
|
|
use(x == i) // ERROR "invalid operation"
|
|
use(i == f) // ERROR "invalid operation"
|
|
use(f == i) // ERROR "invalid operation"
|
|
use(i == m) // ERROR "invalid operation"
|
|
use(m == i) // ERROR "invalid operation"
|
|
}
|