diff options
author | Keith Randall <khr@golang.org> | 2016-06-09 11:07:36 -0700 |
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committer | Keith Randall <khr@golang.org> | 2016-06-09 19:32:51 +0000 |
commit | e3f1c66f313a59888620c415163b93c12153574e (patch) | |
tree | a160258e30248113f265bcda9d4951cea4a2c858 | |
parent | 1bdf1c3024d75a3c4913d031d55257b311f0133f (diff) | |
download | go-e3f1c66f313a59888620c415163b93c12153574e.tar.gz go-e3f1c66f313a59888620c415163b93c12153574e.zip |
cmd/compile: for tail calls in stubs, ensure args are alive
The generated code for interface stubs sometimes just messes
with a few of the args and then tail-calls to the target routine.
The args that aren't explicitly modified appear to not be used.
But they are used, by the thing we're tail calling.
Fixes #16016
Change-Id: Ib9b3a8311bb714a201daee002885fcb59e0463fa
Reviewed-on: https://go-review.googlesource.com/23960
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
-rw-r--r-- | src/cmd/compile/internal/gc/plive.go | 9 | ||||
-rw-r--r-- | test/fixedbugs/issue16016.go | 35 |
2 files changed, 44 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/plive.go b/src/cmd/compile/internal/gc/plive.go index 85138c9fcd..7d0d2dd894 100644 --- a/src/cmd/compile/internal/gc/plive.go +++ b/src/cmd/compile/internal/gc/plive.go @@ -577,6 +577,15 @@ func progeffects(prog *obj.Prog, vars []*Node, uevar bvec, varkill bvec, avarini return } + if prog.As == obj.AJMP && prog.To.Type == obj.TYPE_MEM && prog.To.Name == obj.NAME_EXTERN { + // This is a tail call. Ensure the arguments are still alive. + // See issue 16016. + for i, node := range vars { + if node.Class == PPARAM { + bvset(uevar, int32(i)) + } + } + } if prog.As == obj.ATEXT { // A text instruction marks the entry point to a function and diff --git a/test/fixedbugs/issue16016.go b/test/fixedbugs/issue16016.go new file mode 100644 index 0000000000..e738e1dba0 --- /dev/null +++ b/test/fixedbugs/issue16016.go @@ -0,0 +1,35 @@ +// 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. + +package main + +import "time" + +type T struct{} + +func (*T) Foo(vals []interface{}) { + switch v := vals[0].(type) { + case string: + _ = v + } +} + +type R struct{ *T } + +type Q interface { + Foo([]interface{}) +} + +func main() { + var q Q = &R{&T{}} + for i := 0; i < 10000; i++ { + go func() { + defer q.Foo([]interface{}{"meow"}) + time.Sleep(100 * time.Millisecond) + }() + } + time.Sleep(1 * time.Second) +} |