blob: 78c0d8538df827df61a4ed2064b8d767f6b9f2e3 [file] [log] [blame]
// $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 dummy [512<<20]byte; // give us a big address space
func main() {
// the test only tests what we intend to test
// if dummy starts in the first 256 MB of memory.
// otherwise there might not be anything mapped
// at the address that might be accidentally
// dereferenced below.
if uintptr(unsafe.Pointer(&dummy)) > 256<<20 {
panic("dummy too far out");
// The problem here is that indexing into p[] with a large
// enough index can jump out of the unmapped section
// at the beginning of memory and into valid memory.
// To avoid needing a check on every slice beyond the
// usual len and cap, we require the *array -> slice
// conversion to do the check.
var p *[1<<30]byte = nil;
var x []byte = p; // should crash
_ = x;