From 93468efeb7968071f490656eada6db633f8ffe7b Mon Sep 17 00:00:00 2001 From: David Chase Date: Fri, 23 Dec 2016 12:00:07 -0500 Subject: [release-branch.go1.7] cmd/compile: rewrite literal.method to ensure full initialization CALLPART of STRUCTLIT did not check for incomplete initialization of struct; modify PTRLIT treatment to force zeroing. Test for structlit, believe this might have also failed for arraylit. Fixes #18410. Change-Id: I511abf8ef850e300996d40568944665714efe1fc Reviewed-on: https://go-review.googlesource.com/34622 Run-TryBot: David Chase TryBot-Result: Gobot Gobot Reviewed-by: Keith Randall Reviewed-on: https://go-review.googlesource.com/35636 Run-TryBot: Brad Fitzpatrick --- src/cmd/compile/internal/gc/sinit.go | 2 ++ test/fixedbugs/issue18410.go | 40 ++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 test/fixedbugs/issue18410.go diff --git a/src/cmd/compile/internal/gc/sinit.go b/src/cmd/compile/internal/gc/sinit.go index 4469d71f1c..7d006ff739 100644 --- a/src/cmd/compile/internal/gc/sinit.go +++ b/src/cmd/compile/internal/gc/sinit.go @@ -1042,6 +1042,8 @@ func anylit(ctxt int, n *Node, var_ *Node, init *Nodes) { var r *Node if n.Right != nil { + // n.Right is stack temporary used as backing store. + init.Append(Nod(OAS, n.Right, nil)) // zero backing store, just in case (#18410) r = Nod(OADDR, n.Right, nil) r = typecheck(r, Erv) } else { diff --git a/test/fixedbugs/issue18410.go b/test/fixedbugs/issue18410.go new file mode 100644 index 0000000000..e9c6f862eb --- /dev/null +++ b/test/fixedbugs/issue18410.go @@ -0,0 +1,40 @@ +// run + +// Copyright 2016 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. + +// This checks partially initialized structure literals +// used to create value.method functions have their +// non-initialized fields properly zeroed/nil'd + +package main + +type X struct { + A, B, C *int +} + +//go:noinline +func (t X) Print() { + if t.B != nil { + panic("t.B must be nil") + } +} + +//go:noinline +func caller(f func()) { + f() +} + +//go:noinline +func test() { + var i, j int + x := X{A: &i, C: &j} + caller(func() { X{A: &i, C: &j}.Print() }) + caller(X{A: &i, C: &j}.Print) + caller(x.Print) +} + +func main() { + test() +} -- cgit v1.2.3-54-g00ecf