func newFn()

in windows/mkwinsyscall/mkwinsyscall.go [422:496]
71 lines of code
17 McCabe index (conditional complexity)

func newFn(s string) (*Fn, error) {
	s = trim(s)
	f := &Fn{
		Rets:       &Rets{},
		src:        s,
		PrintTrace: *printTraceFlag,
	}
	// function name and args
	prefix, body, s, found := extractSection(s, '(', ')')
	if !found || prefix == "" {
		return nil, errors.New("Could not extract function name and parameters from \"" + f.src + "\"")
	}
	f.Name = prefix
	var err error
	f.Params, err = extractParams(body, f)
	if err != nil {
		return nil, err
	}
	// return values
	_, body, s, found = extractSection(s, '(', ')')
	if found {
		r, err := extractParams(body, f)
		if err != nil {
			return nil, err
		}
		switch len(r) {
		case 0:
		case 1:
			if r[0].IsError() {
				f.Rets.ReturnsError = true
			} else {
				f.Rets.Name = r[0].Name
				f.Rets.Type = r[0].Type
			}
		case 2:
			if !r[1].IsError() {
				return nil, errors.New("Only last windows error is allowed as second return value in \"" + f.src + "\"")
			}
			f.Rets.ReturnsError = true
			f.Rets.Name = r[0].Name
			f.Rets.Type = r[0].Type
		default:
			return nil, errors.New("Too many return values in \"" + f.src + "\"")
		}
	}
	// fail condition
	_, body, s, found = extractSection(s, '[', ']')
	if found {
		f.Rets.FailCond = body
	}
	// dll and dll function names
	s = trim(s)
	if s == "" {
		return f, nil
	}
	if !strings.HasPrefix(s, "=") {
		return nil, errors.New("Could not extract dll name from \"" + f.src + "\"")
	}
	s = trim(s[1:])
	a := strings.Split(s, ".")
	switch len(a) {
	case 1:
		f.dllfuncname = a[0]
	case 2:
		f.dllname = a[0]
		f.dllfuncname = a[1]
	default:
		return nil, errors.New("Could not extract dll name from \"" + f.src + "\"")
	}
	if n := f.dllfuncname; strings.HasSuffix(n, "?") {
		f.dllfuncname = n[:len(n)-1]
		f.Rets.fnMaybeAbsent = true
	}
	return f, nil
}