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go/test/fixedbugs/issue56990.go
Keith Randall c8057d8569 cmd/compile: disallow CMOV optimization with ptr arithmetic as an arg
if q != nil {
        p = &q.f
    }

Which gets rewritten to a conditional move:

    tmp := &q.f
    p = Select q!=nil, tmp, p

Unfortunately, we can't compute &q.f before we've checked if q is nil,
because if it is nil, &q.f is an invalid pointer (if f's offset is
nonzero but small).

Normally this is not a problem because the tmp variable above
immediately dies, and is thus not live across any safepoint. However,
if later there is another &q.f computation, those two computations are
CSEd, causing tmp to be used at both use points. That will extend
tmp's lifetime, possibly across a call.

Fixes #56990

Change-Id: I3ea31be93feae04fbe3304cb11323194c5df3879
Reviewed-on: https://go-review.googlesource.com/c/go/+/454155
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
2022-11-30 17:46:51 +00:00

120 lines
2.3 KiB
Go

// run
// Copyright 2022 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 (
"fmt"
"path/filepath"
"testing"
)
var t *testing.T
type TypeMeta struct {
Kind string
APIVersion string
}
type ObjectMeta struct {
Name string `json:"name,omitempty" protobuf:"bytes,1,opt,name=name"`
GenerateName string `json:"generateName,omitempty" protobuf:"bytes,2,opt,name=generateName"`
Namespace string `json:"namespace,omitempty" protobuf:"bytes,3,opt,name=namespace"`
SelfLink string `json:"selfLink,omitempty" protobuf:"bytes,4,opt,name=selfLink"`
}
type ConfigSpec struct {
Disks []DiskSpec
StorageClass string
}
type DiskSpec struct {
Name string
Size string
StorageClass string
Annotations map[string]string
VolumeName string
}
// Config is the Schema for the configs API.
type Config struct {
TypeMeta
ObjectMeta
Spec ConfigSpec
}
func findDiskSize(diskSpec *DiskSpec, configSpec *ConfigSpec) string {
t.Log(fmt.Sprintf("Hello World"))
return diskSpec.Size
}
func findStorageClassName(diskSpec *DiskSpec, configSpec *ConfigSpec) *string {
if diskSpec.StorageClass != "" {
return &diskSpec.StorageClass
}
if configSpec != nil {
for _, d := range configSpec.Disks {
if d.Name == diskSpec.Name {
if d.StorageClass != "" {
return &d.StorageClass
}
break
}
}
if configSpec.StorageClass != "" {
return &configSpec.StorageClass
}
}
return nil
}
func Bar(config *Config) *ConfigSpec {
var configSpec *ConfigSpec
if config != nil {
configSpec = &config.Spec
}
return configSpec
}
func Foo(diskSpec DiskSpec, config *Config) {
cs := Bar(config)
_ = findDiskSize(&diskSpec, cs)
cs = Bar(config)
_ = findStorageClassName(&diskSpec, cs)
}
func TestPanic(tt *testing.T) {
t = tt
myarray := []string{filepath.Join("..", "config", "crd", "bases")}
for i := 0; i < 1000; i++ {
Foo(DiskSpec{
Name: "DataDisk",
Size: "1Gi",
}, nil)
}
t.Log(myarray)
}
// Hack to run tests in a playground
func matchString(a, b string) (bool, error) {
return a == b, nil
}
func main() {
testSuite := []testing.InternalTest{
{
Name: "TestPanic",
F: TestPanic,
},
}
testing.Main(matchString, testSuite, nil, nil)
}