func (c *sigctxt) lo() uint64   { return c.regs().sc_mdlo }
func (c *sigctxt) hi() uint64   { return c.regs().sc_mdhi }

func (c *sigctxt) sigcode() uint32 { return uint32(c.info.si_code) }
func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }

func (c *sigctxt) set_r28(x uint64)  { c.regs().sc_regs[28] = x }
func (c *sigctxt) set_r30(x uint64)  { c.regs().sc_regs[30] = x }
func (c *sigctxt) set_pc(x uint64)   { c.regs().sc_pc = x }

func (c *sigctxt) xer() uint64  { return c.regs().xer }
func (c *sigctxt) ccr() uint64  { return c.regs().ccr }

func (c *sigctxt) sigcode() uint32 { return uint32(c.info.si_code) }
func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }
func (c *sigctxt) fault() uintptr  { return uintptr(c.regs().dar) }

func (c *sigctxt) set_r0(x uint64)   { c.regs().gpr[0] = x }
func (c *sigctxt) set_r12(x uint64)  { c.regs().gpr[12] = x }

	syms, err := e.raw.symbols()
	if err != nil {
		return nil, err
	}
	sort.Sort(byAddr(syms))
	return syms, nil
}

type byAddr []Sym

func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr }
func (x byAddr) Len() int           { return len(x) }
func (x byAddr) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }

func (e *Entry) PCLineTable() (Liner, error) {

	sa_flags    uint64
	sa_restorer uintptr
	sa_mask     uint64
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use
	si_addr uint64
}

type siginfo struct {
	siginfoFields

	// Pad struct to the max size in the kernel.
	_ [_si_max_size - unsafe.Sizeof(siginfoFields{})]byte
}

	n = len(tcpRes) - 2
	tcpRes[0] = byte(n >> 8)
	tcpRes[1] = byte(n)
	a.rbuf.Write(tcpRes[2:])

	return len(packet), nil
}

type someaddr struct{}

func (someaddr) Network() string { return "unused" }
func (someaddr) String() string  { return "unused-someaddr" }

func mapRCode(err error) dnsmessage.RCode {
	switch err {
	case nil:
		return dnsmessage.RCodeSuccess
	case ErrNotExist:

		t.Run("", func(t *testing.T) {
			sameAddr, err := sameLocalAddrs(testCase.addr1, testCase.addr2)
			if testCase.expectedErr != nil && err == nil {
				t.Errorf("should fail but succeeded")
			}
			if testCase.expectedErr == nil && err != nil {
				t.Errorf("should succeed but failed with %v", err)
			}
			if err == nil {
				if sameAddr != testCase.sameAddr {

	// 3) the one passed to us as the raddr parameter.
	lsa, _ = syscall.Getsockname(fd.pfd.Sysfd)
	if crsa != nil {
		fd.setAddr(fd.addrFunc()(lsa), fd.addrFunc()(crsa))
	} else if rsa, _ = syscall.Getpeername(fd.pfd.Sysfd); rsa != nil {
		fd.setAddr(fd.addrFunc()(lsa), fd.addrFunc()(rsa))
	} else {
		fd.setAddr(fd.addrFunc()(lsa), raddr)
	}
	return nil
}

func (c *sigctxt) fault() uintptr  { return uintptr(c.sigaddr()) }
func (c *sigctxt) trap() uint32    { return 0 }
func (c *sigctxt) error() uint32   { return 0 }
func (c *sigctxt) oldmask() uint32 { return 0 }

func (c *sigctxt) sigcode() uint32 { return uint32(c.info.si_code) }
func (c *sigctxt) sigaddr() uint32 {
	return *(*uint32)(add(unsafe.Pointer(c.info), 16))
}

	sa_flags    uint64
	sa_restorer uintptr
	sa_mask     uint64
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use
	si_addr uint64
}

type siginfo struct {
	siginfoFields

	// Pad struct to the max size in the kernel.
	_ [_si_max_size - unsafe.Sizeof(siginfoFields{})]byte
}

	sa_restorer uintptr
}

type siginfoFields struct {
	si_signo int32
	si_errno int32
	si_code  int32
	// below here is a union; si_addr is the only field we use
	si_addr uint64
}

type siginfo struct {
	siginfoFields

	// Pad struct to the max size in the kernel.
	_ [_si_max_size - unsafe.Sizeof(siginfoFields{})]byte
}