return nil
	}
	return []string{"-d=libfuzzer"}
}

func instrumentInit() {
	if !cfg.BuildRace && !cfg.BuildMSan && !cfg.BuildASan {
		return
	}
	if cfg.BuildRace && cfg.BuildMSan {
		fmt.Fprintf(os.Stderr, "go: may not use -race and -msan simultaneously\n")
		base.SetExitStatus(2)
		base.Exit()
	}
	if cfg.BuildRace && cfg.BuildASan {
		fmt.Fprintf(os.Stderr, "go: may not use -race and -asan simultaneously\n")

	BuildO             string                  // -o flag
	BuildP             = runtime.GOMAXPROCS(0) // -p flag
	BuildPGO           string                  // -pgo flag
	BuildPkgdir        string                  // -pkgdir flag
	BuildRace          bool                    // -race flag
	BuildToolexec      []string                // -toolexec flag
	BuildToolchainName string
	BuildTrimpath      bool // -trimpath flag
	BuildV             bool // -v flag

		}
	}
	if cfg.BuildCover {
		appendSetting("-cover", "true")
	}
	if cfg.BuildMSan {
		appendSetting("-msan", "true")
	}
	// N.B. -pgo added later by setPGOProfilePath.
	if cfg.BuildRace {
		appendSetting("-race", "true")
	}
	if tags := cfg.BuildContext.BuildTags; len(tags) > 0 {
		appendSetting("-tags", strings.Join(tags, ","))
	}
	if cfg.BuildTrimpath {

	cmd.Flag.BoolVar(&cfg.BuildLinkshared, "linkshared", false, "")
	cmd.Flag.StringVar(&cfg.BuildPGO, "pgo", "auto", "")
	cmd.Flag.StringVar(&cfg.BuildPkgdir, "pkgdir", "", "")
	cmd.Flag.BoolVar(&cfg.BuildRace, "race", false, "")
	cmd.Flag.BoolVar(&cfg.BuildMSan, "msan", false, "")
	cmd.Flag.BoolVar(&cfg.BuildASan, "asan", false, "")
	cmd.Flag.Var((*tagsFlag)(&cfg.BuildContext.BuildTags), "tags", "")