diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go index 4f5fa38a334..8f6da254715 100644 --- a/src/cmd/compile/internal/gc/walk.go +++ b/src/cmd/compile/internal/gc/walk.go @@ -3941,6 +3941,10 @@ func walkCheckPtrArithmetic(n *Node, init *Nodes) *Node { return n } + if n.Left.Op == ODOTPTR && isReflectHeaderDataField(n.Left) { + return n + } + // Find original unsafe.Pointer operands involved in this // arithmetic expression. // diff --git a/test/fixedbugs/issue35027.go b/test/fixedbugs/issue35027.go new file mode 100644 index 00000000000..d4b0be52c10 --- /dev/null +++ b/test/fixedbugs/issue35027.go @@ -0,0 +1,23 @@ +// run -gcflags=-d=checkptr + +// Copyright 2019 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 ( + "reflect" + "unsafe" +) + +var s []int + +func main() { + s = []int{42} + h := (*reflect.SliceHeader)(unsafe.Pointer(&s)) + x := *(*int)(unsafe.Pointer(h.Data)) + if x != 42 { + panic(x) + } +}