register := make(map[string]int16)

	// Standard register names.
	for i := riscv.REG_X0; i <= riscv.REG_X31; i++ {
		// Disallow X3 in shared mode, as this will likely be used as the
		// GP register, which could result in problems in non-Go code,
		// including signal handlers.
		if shared && i == riscv.REG_GP {
			continue
		}
		if i == riscv.REG_TP || i == riscv.REG_G {
			continue
		}

		// invalid according to ISO C anyway (i.e. void (*__cgo_1)(...) is not
		// legal).
		if _, ok := f.(*dwarf.DotDotDotType); ok && i == 0 {
			p, gp = nil, nil
			break
		}
		p[i] = c.FuncArg(f, pos)
		gp[i] = &ast.Field{Type: p[i].Go}
	}
	var r *Type
	var gr []*ast.Field
	if _, ok := base(dtype.ReturnType).(*dwarf.VoidType); ok {
		gr = []*ast.Field{{Type: c.goVoid}}