link_test.go

Documentation: crypto/tls

		 1  // Copyright 2020 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package tls
		 6  
		 7  import (
		 8  	"bytes"
		 9  	"internal/testenv"
		10  	"os"
		11  	"os/exec"
		12  	"path/filepath"
		13  	"testing"
		14  )
		15  
		16  // Tests that the linker is able to remove references to the Client or Server if unused.
		17  func TestLinkerGC(t *testing.T) {
		18  	if testing.Short() {
		19  		t.Skip("skipping in short mode")
		20  	}
		21  	t.Parallel()
		22  	goBin := testenv.GoToolPath(t)
		23  	testenv.MustHaveGoBuild(t)
		24  
		25  	tests := []struct {
		26  		name		string
		27  		program string
		28  		want		[]string
		29  		bad		 []string
		30  	}{
		31  		{
		32  			name: "empty_import",
		33  			program: `package main
		34  import _ "crypto/tls"
		35  func main() {}
		36  `,
		37  			bad: []string{
		38  				"tls.(*Conn)",
		39  				"type.crypto/tls.clientHandshakeState",
		40  				"type.crypto/tls.serverHandshakeState",
		41  			},
		42  		},
		43  		{
		44  			name: "client_and_server",
		45  			program: `package main
		46  import "crypto/tls"
		47  func main() {
		48  	tls.Dial("", "", nil)
		49  	tls.Server(nil, nil)
		50  }
		51  `,
		52  			want: []string{
		53  				"crypto/tls.(*Conn).clientHandshake",
		54  				"crypto/tls.(*Conn).serverHandshake",
		55  			},
		56  		},
		57  		{
		58  			name: "only_client",
		59  			program: `package main
		60  import "crypto/tls"
		61  func main() { tls.Dial("", "", nil) }
		62  `,
		63  			want: []string{
		64  				"crypto/tls.(*Conn).clientHandshake",
		65  			},
		66  			bad: []string{
		67  				"crypto/tls.(*Conn).serverHandshake",
		68  			},
		69  		},
		70  		// TODO: add only_server like func main() { tls.Server(nil, nil) }
		71  		// That currently brings in the client via Conn.handleRenegotiation.
		72  
		73  	}
		74  	tmpDir := t.TempDir()
		75  	goFile := filepath.Join(tmpDir, "x.go")
		76  	exeFile := filepath.Join(tmpDir, "x.exe")
		77  	for _, tt := range tests {
		78  		t.Run(tt.name, func(t *testing.T) {
		79  			if err := os.WriteFile(goFile, []byte(tt.program), 0644); err != nil {
		80  				t.Fatal(err)
		81  			}
		82  			os.Remove(exeFile)
		83  			cmd := exec.Command(goBin, "build", "-o", "x.exe", "x.go")
		84  			cmd.Dir = tmpDir
		85  			if out, err := cmd.CombinedOutput(); err != nil {
		86  				t.Fatalf("compile: %v, %s", err, out)
		87  			}
		88  
		89  			cmd = exec.Command(goBin, "tool", "nm", "x.exe")
		90  			cmd.Dir = tmpDir
		91  			nm, err := cmd.CombinedOutput()
		92  			if err != nil {
		93  				t.Fatalf("nm: %v, %s", err, nm)
		94  			}
		95  			for _, sym := range tt.want {
		96  				if !bytes.Contains(nm, []byte(sym)) {
		97  					t.Errorf("expected symbol %q not found", sym)
		98  				}
		99  			}
	 100  			for _, sym := range tt.bad {
	 101  				if bytes.Contains(nm, []byte(sym)) {
	 102  					t.Errorf("unexpected symbol %q found", sym)
	 103  				}
	 104  			}
	 105  		})
	 106  	}
	 107  }
	 108
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