mirror of
https://github.com/golang/go
synced 2024-11-15 01:30:31 -07:00
8931306389
Expressions involving nil, even if they can be evaluated at compile time, do not count as Go constants and cannot be used in const initializers. Fixes #4673. Fixes #4680. R=ken2 CC=golang-dev https://golang.org/cl/7278043
95 lines
3.3 KiB
Go
95 lines
3.3 KiB
Go
// errorcheck
|
|
|
|
// Copyright 2009 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 overflow is detected when using numeric constants.
|
|
// Does not compile.
|
|
|
|
package main
|
|
|
|
import "unsafe"
|
|
|
|
type I interface{}
|
|
|
|
const (
|
|
// assume all types behave similarly to int8/uint8
|
|
Int8 int8 = 101
|
|
Minus1 int8 = -1
|
|
Uint8 uint8 = 102
|
|
Const = 103
|
|
|
|
Float32 float32 = 104.5
|
|
Float64 float64 = 105.5
|
|
ConstFloat = 106.5
|
|
Big float64 = 1e300
|
|
|
|
String = "abc"
|
|
Bool = true
|
|
)
|
|
|
|
var (
|
|
a1 = Int8 * 100 // ERROR "overflow"
|
|
a2 = Int8 * -1 // OK
|
|
a3 = Int8 * 1000 // ERROR "overflow"
|
|
a4 = Int8 * int8(1000) // ERROR "overflow"
|
|
a5 = int8(Int8 * 1000) // ERROR "overflow"
|
|
a6 = int8(Int8 * int8(1000)) // ERROR "overflow"
|
|
a7 = Int8 - 2*Int8 - 2*Int8 // ERROR "overflow"
|
|
a8 = Int8 * Const / 100 // ERROR "overflow"
|
|
a9 = Int8 * (Const / 100) // OK
|
|
|
|
b1 = Uint8 * Uint8 // ERROR "overflow"
|
|
b2 = Uint8 * -1 // ERROR "overflow"
|
|
b3 = Uint8 - Uint8 // OK
|
|
b4 = Uint8 - Uint8 - Uint8 // ERROR "overflow"
|
|
b5 = uint8(^0) // ERROR "overflow"
|
|
b5a = int64(^0) // OK
|
|
b6 = ^uint8(0) // OK
|
|
b6a = ^int64(0) // OK
|
|
b7 = uint8(Minus1) // ERROR "overflow"
|
|
b8 = uint8(int8(-1)) // ERROR "overflow"
|
|
b8a = uint8(-1) // ERROR "overflow"
|
|
b9 byte = (1 << 10) >> 8 // OK
|
|
b10 byte = (1 << 10) // ERROR "overflow"
|
|
b11 byte = (byte(1) << 10) >> 8 // ERROR "overflow"
|
|
b12 byte = 1000 // ERROR "overflow"
|
|
b13 byte = byte(1000) // ERROR "overflow"
|
|
b14 byte = byte(100) * byte(100) // ERROR "overflow"
|
|
b15 byte = byte(100) * 100 // ERROR "overflow"
|
|
b16 byte = byte(0) * 1000 // ERROR "overflow"
|
|
b16a byte = 0 * 1000 // OK
|
|
b17 byte = byte(0) * byte(1000) // ERROR "overflow"
|
|
b18 byte = Uint8 / 0 // ERROR "division by zero"
|
|
|
|
c1 float64 = Big
|
|
c2 float64 = Big * Big // ERROR "overflow"
|
|
c3 float64 = float64(Big) * Big // ERROR "overflow"
|
|
c4 = Big * Big // ERROR "overflow"
|
|
c5 = Big / 0 // ERROR "division by zero"
|
|
c6 = 1000 % 1e3 // ERROR "floating-point % operation|expected integer type"
|
|
)
|
|
|
|
func f(int)
|
|
|
|
func main() {
|
|
f(Int8) // ERROR "convert|wrong type|cannot"
|
|
f(Minus1) // ERROR "convert|wrong type|cannot"
|
|
f(Uint8) // ERROR "convert|wrong type|cannot"
|
|
f(Const) // OK
|
|
f(Float32) // ERROR "convert|wrong type|cannot"
|
|
f(Float64) // ERROR "convert|wrong type|cannot"
|
|
f(ConstFloat) // ERROR "truncate"
|
|
f(ConstFloat - 0.5) // OK
|
|
f(Big) // ERROR "convert|wrong type|cannot"
|
|
f(String) // ERROR "convert|wrong type|cannot|incompatible"
|
|
f(Bool) // ERROR "convert|wrong type|cannot|incompatible"
|
|
}
|
|
|
|
const ptr = nil // ERROR "const.*nil"
|
|
const _ = string([]byte(nil)) // ERROR "is not a constant"
|
|
const _ = uintptr(unsafe.Pointer((*int)(nil))) // ERROR "is not a constant"
|
|
const _ = unsafe.Pointer((*int)(nil)) // ERROR "cannot be nil"
|
|
const _ = (*int)(nil) // ERROR "cannot be nil"
|