| // $G $D/$F.go && $L $F.$A && (! ./$A.out || echo BUG: should fail) |
| |
| // 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. |
| |
| package main |
| |
| import "unsafe" |
| |
| var x byte |
| |
| func main() { |
| var p *[1<<30]byte = nil; |
| x = 123; |
| |
| // The problem here is not the use of unsafe: |
| // it is that indexing into p[] with a large |
| // enough index jumps out of the unmapped section |
| // at the beginning of memory and into valid memory. |
| // Pointer offsets and array indices, if they are |
| // very large, need to dereference the base pointer |
| // to trigger a trap. |
| println(p[uintptr(unsafe.Pointer(&x))]); |
| } |
