mirror of
https://github.com/golang/go
synced 2024-11-27 00:11:19 -07:00
ceffdc8545
The conversion T(x) is implemented as *(*T)(x). Accordingly, runtime panic messages for (*T)(x) are made more general. Fixes #46505. Change-Id: I76317c0878b6a5908299506d392eed50d7ef6523 Reviewed-on: https://go-review.googlesource.com/c/go/+/430415 Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Jenny Rakoczy <jenny@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Keith Randall <khr@golang.org>
109 lines
2.1 KiB
Go
109 lines
2.1 KiB
Go
// run
|
|
|
|
// Copyright 2020 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.
|
|
|
|
// Test conversion from slice to array pointer.
|
|
|
|
package main
|
|
|
|
func wantPanic(fn func(), s string) {
|
|
defer func() {
|
|
err := recover()
|
|
if err == nil {
|
|
panic("expected panic")
|
|
}
|
|
if got := err.(error).Error(); got != s {
|
|
panic("expected panic " + s + " got " + got)
|
|
}
|
|
}()
|
|
fn()
|
|
}
|
|
|
|
func main() {
|
|
s := make([]byte, 8, 10)
|
|
for i := range s {
|
|
s[i] = byte(i)
|
|
}
|
|
if p := (*[8]byte)(s); &p[0] != &s[0] {
|
|
panic("*[8]byte conversion failed")
|
|
}
|
|
if [8]byte(s) != *(*[8]byte)(s) {
|
|
panic("[8]byte conversion failed")
|
|
}
|
|
wantPanic(
|
|
func() {
|
|
_ = (*[9]byte)(s)
|
|
},
|
|
"runtime error: cannot convert slice with length 8 to array or pointer to array with length 9",
|
|
)
|
|
wantPanic(
|
|
func() {
|
|
_ = [9]byte(s)
|
|
},
|
|
"runtime error: cannot convert slice with length 8 to array or pointer to array with length 9",
|
|
)
|
|
|
|
var n []byte
|
|
if p := (*[0]byte)(n); p != nil {
|
|
panic("nil slice converted to *[0]byte should be nil")
|
|
}
|
|
_ = [0]byte(n)
|
|
|
|
z := make([]byte, 0)
|
|
if p := (*[0]byte)(z); p == nil {
|
|
panic("empty slice converted to *[0]byte should be non-nil")
|
|
}
|
|
_ = [0]byte(z)
|
|
|
|
var p *[]byte
|
|
wantPanic(
|
|
func() {
|
|
_ = [0]byte(*p) // evaluating *p should still panic
|
|
},
|
|
"runtime error: invalid memory address or nil pointer dereference",
|
|
)
|
|
|
|
// Test with named types
|
|
type Slice []int
|
|
type Int4 [4]int
|
|
type PInt4 *[4]int
|
|
ii := make(Slice, 4)
|
|
if p := (*Int4)(ii); &p[0] != &ii[0] {
|
|
panic("*Int4 conversion failed")
|
|
}
|
|
if p := PInt4(ii); &p[0] != &ii[0] {
|
|
panic("PInt4 conversion failed")
|
|
}
|
|
}
|
|
|
|
// test static variable conversion
|
|
|
|
var (
|
|
ss = make([]string, 10)
|
|
s5 = (*[5]string)(ss)
|
|
s10 = (*[10]string)(ss)
|
|
|
|
ns []string
|
|
ns0 = (*[0]string)(ns)
|
|
|
|
zs = make([]string, 0)
|
|
zs0 = (*[0]string)(zs)
|
|
)
|
|
|
|
func init() {
|
|
if &ss[0] != &s5[0] {
|
|
panic("s5 conversion failed")
|
|
}
|
|
if &ss[0] != &s10[0] {
|
|
panic("s5 conversion failed")
|
|
}
|
|
if ns0 != nil {
|
|
panic("ns0 should be nil")
|
|
}
|
|
if zs0 == nil {
|
|
panic("zs0 should not be nil")
|
|
}
|
|
}
|