You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: so_test.go
    path of file: ./repos/gccrs/libgo/misc/cgo/testso
    
    the code of the file until where you have to start completion: // Copyright 2019 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.

//go:build cgo
// +build cgo

package so_test

import (
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
)

func requireTestSOSupported(t *testing.T) {
	t.Helper()
	switch runtime.GOARCH {
	case "arm64":
		if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
			t.Skip("No exec facility on iOS.")
		}
	case "ppc64":
		if runtime.GOOS == "linux" {
			t.Skip("External linking not implemented on linux/ppc64 (issue #8912).")
		}
	}
	if runtime.GOOS == "android" {
		t.Skip("No exec facility on Android.")
	}
}

func TestSO(t *testing.T) {
	requireTestSOSupported(t)

	GOPATH, err := os.MkdirTemp("", "cgosotest")
	if err != nil {
		log.Fatal(err)
	}
	defer os.RemoveAll(GOPATH)

	modRoot := filepath.Join(GOPATH, "src", "cgosotest")
	if err := overlayDir(modRoot, "testdata"); err != nil {
		log.Panic(err)
	}
	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
		log.Panic(err)
	}

	cmd := exec.Command("go", "env", "CC", "GOGCCFLAGS")
	cmd.Dir = modRoot
	cmd.Stderr = new(strings.Builder)
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	out, err := cmd.Output()
	if err != nil {
		t.Fatalf("%s: %v\n%s", strings.Join(cmd.Args, " "), err, cmd.Stderr)
	}
	lines := strings.Split(string(out), "\n")
	if len(lines) != 3 || lines[2] != "" {
		t.Fatalf("Unexpected output from %s:\n%s", strings.Join(cmd.Args, " "), lines)
	}

	cc := lines[0]
	if cc == "" {
		t.Fatal("CC environment variable (go env CC) cannot be empty")
	}
	gogccflags := strings.Split(lines[1], " ")

	// build shared object
	ext := "so"
	args := append(gogccflags, "-shared")
	switch runtime.GOOS {
	case "darwin", "ios":
		ext = "dylib"
		args = append(args, "-undefined", "suppress", "-flat_namespace")
	case "windows":
		ext = "dll"
		args = append(args, "-DEXPORT_DLL")
		// At least in mingw-clang it is not permitted to just name a .dll
		// on the command line. You must name the corresponding import
		// library instead, even though the dll is used when the executable is run.
		args = append(args, "-Wl,-out-implib,libcgosotest.a")
	case "aix":
		ext = "so.1"
	}
	sofname := "libcgosotest." + ext
	args = append(args, "-o", sofname, "cgoso_c.c")

	cmd = exec.Command(cc, args...)
	cmd.Dir = modRoot
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	out, err = cmd.Combined
    
func TestSO(t *testing.T) {
	requireTestSOSupported(t)

	GOPATH, err := os.MkdirTemp("", "cgosotest")
	if err != nil {
		log.Fatal(err)
	}
	defer os.RemoveAll(GOPATH)

	modRoot := filepath.Join(GOPATH, "src", "cgosotest")
	if err := overlayDir(modRoot, "testdata"); err != nil {
		log.Panic(err)
	}
	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
		log.Panic(err)
	}

	cmd := exec.Command("go", "env", "CC", "GOGCCFLAGS")
	cmd.Dir = modRoot
	cmd.Stderr = new(strings.Builder)
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	out, err := cmd.Output()
	if err != nil {
		t.Fatalf("%s: %v\n%s", strings.Join(cmd.Args, " "), err, cmd.Stderr)
	}
	lines := strings.Split(string(out), "\n")
	if len(lines) != 3 || lines[2] != "" {
		t.Fatalf("Unexpected output from %s:\n%s", strings.Join(cmd.Args, " "), lines)
	}

	cc := lines[0]
	if cc == "" {
		t.Fatal("CC environment variable (go env CC) cannot be empty")
	}
	gogccflags := strings.Split(lines[1], " ")

	// build shared object
	ext := "so"
	args := append(gogccflags, "-shared")
	switch runtime.GOOS {
	case "darwin", "ios":
		ext = "dylib"
		args = append(args, "-undefined", "suppress", "-flat_namespace")
	case "windows":
		ext = "dll"
		args = append(args, "-DEXPORT_DLL")
		// At least in mingw-clang it is not permitted to just name a .dll
		// on the command line. You must name the corresponding import
		// library instead, even though the dll is used when the executable is run.
		args = append(args, "-Wl,-out-implib,libcgosotest.a")
	case "aix":
		ext = "so.1"
	}
	sofname := "libcgosotest." + ext
	args = append(args, "-o", sofname, "cgoso_c.c")

	cmd = exec.Command(cc, args...)
	cmd.Dir = modRoot
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	out, err = cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("%s: %s\n%s", strings.Join(cmd.Args, " "), err, out)
	}
	t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out)

	if runtime.GOOS == "aix" {
		// Shared object must be wrapped by an archive
		cmd = exec.Command("ar", "-X64", "-q", "libcgosotest.a", "libcgosotest.so.1")
		cmd.Dir = modRoot
		out, err = cmd.CombinedOutput()
		if err != nil {
			t.Fatalf("%s: %s\n%s", strings.Join(cmd.Args, " "), err, out)
		}
	}

	cmd = exec.Command("go", "build", "-o", "main.exe", "main.go")
	cmd.Dir = modRoot
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	out, err = cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("%s: %s\n%s", strings.Join(cmd.Args, " "), err, out)
	}
	t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out)

	cmd = exec.Command("./main.exe")
	cmd.Dir = modRoot
	cmd.Env = append(os.Environ(), "GOPATH="+GOPATH)
	if runtime.GOOS != "windows" {
		s := "LD_LIBRARY_PATH"
		if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
			s = "DYLD_LIBRARY_PATH"
		}
		cmd.Env = append(os.Environ(), s+"=.")

		// On FreeBSD 64-bit architectures, the 32-bit linker looks for
		// different environment variables.
		if runtime.GOOS == "freebsd" && runtime.GOARCH == "386" {
			cmd.Env = append(cmd.Env, "LD_32_LIBRARY_PATH=.")
		}
	}
	out, err = cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("%s: %s\n%s", strings.Join(cmd.Args, " "), err, out)
	}
	t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out)
}