blob: c1fb57e70e2d8352aec985c128779c8b32b8e6ad [file] [log] [blame]
// Copyright 2020 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 tls
import (
"bytes"
"internal/testenv"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"testing"
)
// Tests that the linker is able to remove references to the Client or Server if unused.
func TestLinkerGC(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
t.Parallel()
goBin := testenv.GoToolPath(t)
testenv.MustHaveGoBuild(t)
tests := []struct {
name string
program string
want []string
bad []string
}{
{
name: "empty_import",
program: `package main
import _ "crypto/tls"
func main() {}
`,
bad: []string{
"tls.(*Conn)",
"type.crypto/tls.clientHandshakeState",
"type.crypto/tls.serverHandshakeState",
},
},
{
name: "only_conn",
program: `package main
import "crypto/tls"
var c = new(tls.Conn)
func main() {}
`,
want: []string{"tls.(*Conn)"},
bad: []string{
"type.crypto/tls.clientHandshakeState",
"type.crypto/tls.serverHandshakeState",
},
},
{
name: "client_and_server",
program: `package main
import "crypto/tls"
func main() {
tls.Dial("", "", nil)
tls.Server(nil, nil)
}
`,
want: []string{
"crypto/tls.(*Conn).clientHandshake",
"crypto/tls.(*Conn).serverHandshake",
},
},
{
name: "only_client",
program: `package main
import "crypto/tls"
func main() { tls.Dial("", "", nil) }
`,
want: []string{
"crypto/tls.(*Conn).clientHandshake",
},
bad: []string{
"crypto/tls.(*Conn).serverHandshake",
},
},
// TODO: add only_server like func main() { tls.Server(nil, nil) }
// That currently brings in the client via Conn.handleRenegotiation.
}
tmpDir := t.TempDir()
goFile := filepath.Join(tmpDir, "x.go")
exeFile := filepath.Join(tmpDir, "x.exe")
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if err := ioutil.WriteFile(goFile, []byte(tt.program), 0644); err != nil {
t.Fatal(err)
}
os.Remove(exeFile)
cmd := exec.Command(goBin, "build", "-o", "x.exe", "x.go")
cmd.Dir = tmpDir
if out, err := cmd.CombinedOutput(); err != nil {
t.Fatalf("compile: %v, %s", err, out)
}
cmd = exec.Command(goBin, "tool", "nm", "x.exe")
cmd.Dir = tmpDir
nm, err := cmd.CombinedOutput()
if err != nil {
t.Fatalf("nm: %v, %s", err, nm)
}
for _, sym := range tt.want {
if !bytes.Contains(nm, []byte(sym)) {
t.Errorf("expected symbol %q not found", sym)
}
}
for _, sym := range tt.bad {
if bytes.Contains(nm, []byte(sym)) {
t.Errorf("unexpected symbol %q found", sym)
}
}
})
}
}