func()

in cmd/bent/configuration.go [152:274]
108 lines of code
20 McCabe index (conditional complexity)

func (config *Configuration) compileOne(bench *Benchmark, cwd string, count int) string {
	root := config.rootCopy
	gocmd := config.goCommandCopy()
	gopath := path.Join(cwd, "gopath")

	if explicitAll != 1 { // clear cache unless "-a[=1]" which requests -a on compilation.
		cmd := exec.Command(gocmd, "clean", "-cache")
		cmd.Env = defaultEnv
		if !bench.NotSandboxed {
			cmd.Env = replaceEnv(cmd.Env, "GOOS", "linux")
		}
		if root != "" {
			cmd.Env = replaceEnv(cmd.Env, "GOROOT", root)
		}
		cmd.Env = replaceEnvs(cmd.Env, bench.GcEnv)
		cmd.Env = replaceEnvs(cmd.Env, config.GcEnv)
		cmd.Dir = gopath // Only want the cache-cleaning effect, not the binary-deleting effect. It's okay to clean gopath.
		s, _ := config.runBinary("", cmd, true)
		if s != "" {
			fmt.Println("Error running go clean -cache, ", s)
		}
	}

	cmd := exec.Command(gocmd, "test", "-vet=off", "-c")
	compileTo := path.Join(dirs.wd, dirs.testBinDir, config.benchName(bench))
	cmd.Args = append(cmd.Args, "-o", compileTo)
	cmd.Args = append(cmd.Args, bench.BuildFlags...)
	// Do not normally need -a because cache was emptied first and std was -a installed with these flags.
	// But for -a=1, do it anyway
	if explicitAll == 1 {
		cmd.Args = append(cmd.Args, "-a")
	}
	cmd.Args = append(cmd.Args, config.BuildFlags...)
	if config.GcFlags != "" {
		cmd.Args = append(cmd.Args, "-gcflags="+config.GcFlags)
	}
	cmd.Args = append(cmd.Args, bench.Repo)
	cmd.Dir = bench.BuildDir // use module-mode
	cmd.Env = defaultEnv
	if !bench.NotSandboxed {
		cmd.Env = replaceEnv(cmd.Env, "GOOS", "linux")
	}
	if root != "" {
		cmd.Env = replaceEnv(cmd.Env, "GOROOT", root)
	}
	cmd.Env = replaceEnvs(cmd.Env, bench.GcEnv)
	cmd.Env = replaceEnvs(cmd.Env, config.GcEnv)

	if verbose > 0 {
		fmt.Println(asCommandLine(cwd, cmd))
	} else {
		fmt.Print(".")
	}

	defer cleanup(gopath)

	start := time.Now()
	output, err := cmd.CombinedOutput()
	realTime := time.Since(start)
	if err != nil {
		s := ""
		switch e := err.(type) {
		case *exec.ExitError:
			s = fmt.Sprintf("There was an error running 'go test', output = %s", output)
		default:
			s = fmt.Sprintf("There was an error running 'go test', output = %s, error = %v", output, e)
		}
		fmt.Println(s + "DISABLING benchmark " + bench.Name)
		bench.Disabled = true // if it won't compile, it won't run, either.
		return s + "(" + bench.Name + ")\n"
	}
	soutput := string(output)
	bs := BenchStat{
		Name:     bench.Name,
		RealTime: realTime,
		UserTime: cmd.ProcessState.UserTime(),
		SysTime:  cmd.ProcessState.SystemTime(),
	}
	config.buildStats = append(config.buildStats, bs)

	// Report and record build stats to testbin

	buf := new(bytes.Buffer)
	configGoArch := getenv(config.GcEnv, "GOARCH")
	if configGoArch != runtime.GOARCH && configGoArch != "" {
		s := fmt.Sprintf("goarch: %s-%s\n", runtime.GOARCH, configGoArch)
		if verbose > 0 {
			fmt.Print(s)
		}
		buf.WriteString(s)
	}
	s := fmt.Sprintf("Benchmark%s 1 %d build-real-ns/op %d build-user-ns/op %d build-sys-ns/op\n",
		strings.Title(bench.Name), bs.RealTime.Nanoseconds(), bs.UserTime.Nanoseconds(), bs.SysTime.Nanoseconds())
	if verbose > 0 {
		fmt.Print(s)
	}
	buf.WriteString(s)
	f, err := os.OpenFile(config.buildBenchName(), os.O_WRONLY|os.O_APPEND, os.ModePerm)
	if err != nil {
		fmt.Printf("There was an error opening %s for append, error %v\n", config.buildBenchName(), err)
		cleanup(gopath)
		os.Exit(2)
	}
	f.Write(buf.Bytes())
	f.Sync()
	f.Close()

	// Trim /usr/bin/time info from soutput, it's ugly
	if verbose > 0 {
		i := strings.LastIndex(soutput, "real")
		if i >= 0 {
			soutput = soutput[:i]
		}
		fmt.Print(soutput)
	}

	// Do this here before any cleanup.
	if count == 0 {
		config.runOtherBenchmarks(bench, cwd)
	}

	return ""
}