var lastAddr, maxAddr uint64
		for i, inst := range insts {
			addr := inst.Addr + base

			// Guard against duplicate output from Disasm.
			if addr <= maxAddr {
				continue
			}
			maxAddr = addr

			length := 1
			if i+1 < len(insts) && insts[i+1].Addr > inst.Addr {
				// Extend to next instruction.
				length = int(insts[i+1].Addr - inst.Addr)
			}

			// Get inlined-call-stack for address.

		// that was causing b to escape and be heap allocated.
		// See issue 23382.
		// TODO: once issue 7921 is fixed, this should be reverted to
		// just "b.addr = b".
		b.addr = (*Builder)(abi.NoEscape(unsafe.Pointer(b)))
	} else if b.addr != b {
		panic("strings: illegal use of non-zero Builder copied by value")
	}
}

// String returns the accumulated string.
func (b *Builder) String() string {

	destroySet(name string) error
	addIP(name string, ip netip.Addr, ipProto uint8, comment string, replace bool) error
	deleteIP(name string, ip netip.Addr, ipProto uint8) error
	flush(name string) error
	clearEntriesWithComment(name string, comment string) error
	clearEntriesWithIP(name string, ip netip.Addr) error
	listEntriesByIP(name string) ([]netip.Addr, error)
}

func Mk128(hi, lo uint64) Uint128 {
	return uint128{hi, lo}
}

func MkAddr(u Uint128, z unique.Handle[AddrDetail]) Addr {
	return Addr{u, z}
}

func IPv4(a, b, c, d uint8) Addr { return AddrFrom4([4]byte{a, b, c, d}) }

var TestAppendToMarshal = testAppendToMarshal

func (a Addr) IsZero() bool   { return a.isZero() }
func (p Prefix) IsZero() bool { return p.isZero() }

func TestAppendPortIfNeeded(t *testing.T) {
	testCases := []struct {
		name   string
		addr   string
		port   int32
		expect string
	}{
		{
			name:   "IPv4 all-zeros bind address has port",
			addr:   "0.0.0.0:12345",
			port:   23456,
			expect: "0.0.0.0:12345",
		},
		{
			name:   "non-zeros IPv4 config",
			addr:   "9.8.7.6",
			port:   12345,
			expect: "9.8.7.6:12345",
		},
		{

		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	if err := setKeepAliveIdle(c.fd, config.Idle); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	if err := setKeepAliveInterval(c.fd, config.Interval); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}

		case _C_AF_INET:
			sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(*_C_ai_addr(r)))
			addr := IPAddr{IP: copyIP(sa.Addr[:])}
			addrs = append(addrs, addr)
		case _C_AF_INET6:
			sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(*_C_ai_addr(r)))
			addr := IPAddr{IP: copyIP(sa.Addr[:]), Zone: zoneCache.name(int(sa.Scope_id))}
			addrs = append(addrs, addr)
		}
	}
	return addrs, nil
}

        loadbalance
        kubernetes cluster.local in-addr.arpa ip6.arpa {
           pods insecure
           upstream
           fallthrough in-addr.arpa ip6.arpa
           ttl 30
        }
        health
    }
`,
			expectedCorefileData: `.:53 {
    errors
    health {
       lameduck 5s
    }
    ready
    kubernetes cluster.local in-addr.arpa ip6.arpa {
       pods insecure

		for ; result != nil; result = result.Next {
			addr := unsafe.Pointer(result.Addr)
			switch result.Family {
			case syscall.AF_INET:
				a := (*syscall.RawSockaddrInet4)(addr).Addr
				addrs = append(addrs, IPAddr{IP: copyIP(a[:])})
			case syscall.AF_INET6:
				a := (*syscall.RawSockaddrInet6)(addr).Addr
				zone := zoneCache.name(int((*syscall.RawSockaddrInet6)(addr).Scope_id))

		return secs[i].Addr < secs[j].Addr
	})

	// Check to make sure we don't have any overlaps.
	foundOverlap := false
	for i := 0; i < len(secs)-1; i++ {
		for j := i + 1; j < len(secs); j++ {
			s := secs[i]
			sn := secs[j]
			if secOverlaps(s, sn) {
				t.Errorf("unexpected: section %d:%q (addr=%x size=%x) overlaps section %d:%q (addr=%x size=%x)", i, s.Name, s.Addr, s.Size, i+1, sn.Name, sn.Addr, sn.Size)