all: update exp/slices and fix call sites

slices.SortFunc suffered a late-in-cycle API breakage.

Updates #cleanup

Signed-off-by: David Anderson <danderson@tailscale.com>

cmd/derper/depaware.txt

@@ -47,7 +47,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
    L    github.com/vishvananda/netns                                 from github.com/tailscale/netlink+
         github.com/x448/float16                                      from github.com/fxamacker/cbor/v2
      💣 go4.org/mem                                                  from tailscale.com/client/tailscale+
-        go4.org/netipx                                               from tailscale.com/wgengine/filter
+        go4.org/netipx                                               from tailscale.com/wgengine/filter+
    W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
         google.golang.org/protobuf/encoding/prototext                from github.com/golang/protobuf/proto+
         google.golang.org/protobuf/encoding/protowire                from github.com/golang/protobuf/proto+

cmd/netlogfmt/main.go

@@ -45,6 +45,7 @@ import (
 	"golang.org/x/exp/slices"
 	"tailscale.com/types/logid"
 	"tailscale.com/types/netlogtype"
+	"tailscale.com/util/cmpx"
 	"tailscale.com/util/must"
 )
 
@@ -151,10 +152,10 @@ func printMessage(msg message) {
 		if len(traffic) == 0 {
 			return
 		}
-		slices.SortFunc(traffic, func(x, y netlogtype.ConnectionCounts) bool {
+		slices.SortFunc(traffic, func(x, y netlogtype.ConnectionCounts) int {
 			nx := x.TxPackets + x.TxBytes + x.RxPackets + x.RxBytes
 			ny := y.TxPackets + y.TxBytes + y.RxPackets + y.RxBytes
-			return nx > ny
+			return cmpx.Compare(ny, nx)
 		})
 		var sum netlogtype.Counts
 		for _, cc := range traffic {

cmd/tailscale/cli/exitnode.go

@@ -18,6 +18,7 @@ import (
 	"golang.org/x/exp/slices"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
+	"tailscale.com/util/cmpx"
 )
 
 var exitNodeCmd = &ffcli.Command{
@@ -227,19 +228,21 @@ func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string)
 // sortPeersByPriority sorts a slice of PeerStatus
 // by location.Priority, in order of highest priority.
 func sortPeersByPriority(peers []*ipnstate.PeerStatus) {
-	slices.SortFunc(peers, func(a, b *ipnstate.PeerStatus) bool { return a.Location.Priority > b.Location.Priority })
+	slices.SortStableFunc(peers, func(a, b *ipnstate.PeerStatus) int {
+		return cmpx.Compare(b.Location.Priority, a.Location.Priority)
+	})
 }
 
 // sortByCityName sorts a slice of filteredCity alphabetically
 // by name. The '-' used to indicate no location data will always
 // be sorted to the front of the slice.
 func sortByCityName(cities []*filteredCity) {
-	slices.SortFunc(cities, func(a, b *filteredCity) bool { return a.Name < b.Name })
+	slices.SortStableFunc(cities, func(a, b *filteredCity) int { return strings.Compare(a.Name, b.Name) })
 }
 
 // sortByCountryName sorts a slice of filteredCountry alphabetically
 // by name. The '-' used to indicate no location data will always
 // be sorted to the front of the slice.
 func sortByCountryName(countries []*filteredCountry) {
-	slices.SortFunc(countries, func(a, b *filteredCountry) bool { return a.Name < b.Name })
+	slices.SortStableFunc(countries, func(a, b *filteredCountry) int { return strings.Compare(a.Name, b.Name) })
 }

cmd/tailscale/depaware.txt

@@ -52,7 +52,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
    L    github.com/vishvananda/netns                                 from github.com/tailscale/netlink+
         github.com/x448/float16                                      from github.com/fxamacker/cbor/v2
      💣 go4.org/mem                                                  from tailscale.com/derp+
-        go4.org/netipx                                               from tailscale.com/wgengine/filter
+        go4.org/netipx                                               from tailscale.com/wgengine/filter+
    W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
         gopkg.in/yaml.v2                                             from sigs.k8s.io/yaml
         k8s.io/client-go/util/homedir                                from tailscale.com/cmd/tailscale/cli

go.mod

@@ -73,10 +73,10 @@ require (
 	github.com/vishvananda/netns v0.0.4
 	go.uber.org/zap v1.24.0
 	go4.org/mem v0.0.0-20220726221520-4f986261bf13
-	go4.org/netipx v0.0.0-20230303233057-f1b76eb4bb35
+	go4.org/netipx v0.0.0-20230728180743-ad4cb58a6516
 	golang.org/x/crypto v0.11.0
-	golang.org/x/exp v0.0.0-20230425010034-47ecfdc1ba53
+	golang.org/x/exp v0.0.0-20230725093048-515e97ebf090
-	golang.org/x/mod v0.10.0
+	golang.org/x/mod v0.11.0
 	golang.org/x/net v0.10.0
 	golang.org/x/oauth2 v0.7.0
 	golang.org/x/sync v0.2.0

go.sum

@@ -1183,8 +1183,8 @@ go.uber.org/zap v1.24.0 h1:FiJd5l1UOLj0wCgbSE0rwwXHzEdAZS6hiiSnxJN/D60=
 go.uber.org/zap v1.24.0/go.mod h1:2kMP+WWQ8aoFoedH3T2sq6iJ2yDWpHbP0f6MQbS9Gkg=
 go4.org/mem v0.0.0-20220726221520-4f986261bf13 h1:CbZeCBZ0aZj8EfVgnqQcYZgf0lpZ3H9rmp5nkDTAst8=
 go4.org/mem v0.0.0-20220726221520-4f986261bf13/go.mod h1:reUoABIJ9ikfM5sgtSF3Wushcza7+WeD01VB9Lirh3g=
-go4.org/netipx v0.0.0-20230303233057-f1b76eb4bb35 h1:nJAwRlGWZZDOD+6wni9KVUNHMpHko/OnRwsrCYeAzPo=
+go4.org/netipx v0.0.0-20230728180743-ad4cb58a6516 h1:X66ZEoMN2SuaoI/dfZVYobB6E5zjZyyHUMWlCA7MgGE=
-go4.org/netipx v0.0.0-20230303233057-f1b76eb4bb35/go.mod h1:TQvodOM+hJTioNQJilmLXu08JNb8i+ccq418+KWu1/Y=
+go4.org/netipx v0.0.0-20230728180743-ad4cb58a6516/go.mod h1:TQvodOM+hJTioNQJilmLXu08JNb8i+ccq418+KWu1/Y=
 golang.org/x/arch v0.1.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -1222,8 +1222,8 @@ golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
-golang.org/x/exp v0.0.0-20230425010034-47ecfdc1ba53 h1:5llv2sWeaMSnA3w2kS57ouQQ4pudlXrR0dCgw51QK9o=
+golang.org/x/exp v0.0.0-20230725093048-515e97ebf090 h1:Di6/M8l0O2lCLc6VVRWhgCiApHV8MnQurBnFSHsQtNY=
-golang.org/x/exp v0.0.0-20230425010034-47ecfdc1ba53/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=
+golang.org/x/exp v0.0.0-20230725093048-515e97ebf090/go.mod h1:FXUEEKJgO7OQYeo8N01OfiKP8RXMtf6e8aTskBGqWdc=
 golang.org/x/exp/typeparams v0.0.0-20220428152302-39d4317da171/go.mod h1:AbB0pIl9nAr9wVwH+Z2ZpaocVmF5I4GyWCDIsVjR0bk=
 golang.org/x/exp/typeparams v0.0.0-20230203172020-98cc5a0785f9/go.mod h1:AbB0pIl9nAr9wVwH+Z2ZpaocVmF5I4GyWCDIsVjR0bk=
 golang.org/x/exp/typeparams v0.0.0-20230425010034-47ecfdc1ba53 h1:w/MOPdQ1IoYoDou3L55ZbTx2Nhn7JAhX1BBZor8qChU=
@@ -1261,8 +1261,8 @@ golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91
 golang.org/x/mod v0.6.0/go.mod h1:4mET923SAdbXp2ki8ey+zGs1SLqsuM2Y0uvdZR/fUNI=
 golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
+golang.org/x/mod v0.11.0 h1:bUO06HqtnRcc/7l71XBe4WcqTZ+3AH1J59zWDDwLKgU=
-golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.11.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

ipn/ipnlocal/peerapi.go

@@ -902,8 +902,8 @@ func (h *peerAPIHandler) handleServeSockStats(w http.ResponseWriter, r *http.Req
 	for label := range stats.Stats {
 		labels = append(labels, label)
 	}
-	slices.SortFunc(labels, func(a, b sockstats.Label) bool {
+	slices.SortFunc(labels, func(a, b sockstats.Label) int {
-		return a.String() < b.String()
+		return strings.Compare(a.String(), b.String())
 	})
 
 	txTotal := uint64(0)

ipn/ipnlocal/profiles.go

@@ -298,8 +298,8 @@ func (pm *profileManager) writePrefsToStore(key ipn.StateKey, prefs ipn.PrefsVie
 // Profiles returns the list of known profiles.
 func (pm *profileManager) Profiles() []ipn.LoginProfile {
 	profiles := pm.matchingProfiles(func(*ipn.LoginProfile) bool { return true })
-	slices.SortFunc(profiles, func(a, b *ipn.LoginProfile) bool {
+	slices.SortFunc(profiles, func(a, b *ipn.LoginProfile) int {
-		return a.Name < b.Name
+		return strings.Compare(a.Name, b.Name)
 	})
 	out := make([]ipn.LoginProfile, 0, len(profiles))
 	for _, p := range profiles {

net/dns/manager.go

@@ -12,6 +12,7 @@ import (
 	"net"
 	"net/netip"
 	"runtime"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -139,14 +140,15 @@ func compileHostEntries(cfg Config) (hosts []*HostEntry) {
 			}
 		}
 	}
-	slices.SortFunc(hosts, func(a, b *HostEntry) bool {
+	slices.SortFunc(hosts, func(a, b *HostEntry) int {
-		if len(a.Hosts) == 0 {
+		if len(a.Hosts) == 0 && len(b.Hosts) == 0 {
-			return false
+			return 0
+		} else if len(a.Hosts) == 0 {
+			return -1
+		} else if len(b.Hosts) == 0 {
+			return 1
 		}
-		if len(b.Hosts) == 0 {
+		return strings.Compare(a.Hosts[0], b.Hosts[0])
-			return true
-		}
-		return a.Hosts[0] < b.Hosts[0]
 	})
 	return hosts
 }

net/dns/recursive/recursive_test.go

@@ -366,8 +366,8 @@ func TestBasicRecursion(t *testing.T) {
 		netip.MustParseAddr("2600:9000:a602:b1e6:86d:8165:5e8c:295b"),
 		netip.MustParseAddr("2600:9000:a51d:27c1:1530:b9ef:2a6:b9e5"),
 	}
-	slices.SortFunc(addrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(addrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
-	slices.SortFunc(wantAddrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(wantAddrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
 
 	if !reflect.DeepEqual(addrs, wantAddrs) {
 		t.Errorf("got addrs=%+v; want %+v", addrs, wantAddrs)
@@ -485,8 +485,8 @@ func TestRecursionCNAME(t *testing.T) {
 		netip.MustParseAddr("13.248.141.131"),
 		netip.MustParseAddr("2600:9000:a602:b1e6:86d:8165:5e8c:295b"),
 	}
-	slices.SortFunc(addrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(addrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
-	slices.SortFunc(wantAddrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(wantAddrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
 
 	if !reflect.DeepEqual(addrs, wantAddrs) {
 		t.Errorf("got addrs=%+v; want %+v", addrs, wantAddrs)
@@ -590,8 +590,8 @@ func TestRecursionNoGlue(t *testing.T) {
 		netip.MustParseAddr("13.248.141.131"),
 		netip.MustParseAddr("2600:9000:a602:b1e6:86d:8165:5e8c:295b"),
 	}
-	slices.SortFunc(addrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(addrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
-	slices.SortFunc(wantAddrs, func(x, y netip.Addr) bool { return x.String() < y.String() })
+	slices.SortFunc(wantAddrs, func(x, y netip.Addr) int { return strings.Compare(x.String(), y.String()) })
 
 	if !reflect.DeepEqual(addrs, wantAddrs) {
 		t.Errorf("got addrs=%+v; want %+v", addrs, wantAddrs)

net/dnsfallback/dnsfallback.go

@@ -22,6 +22,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"go4.org/netipx"
 	"golang.org/x/exp/slices"
 	"tailscale.com/atomicfile"
 	"tailscale.com/envknob"
@@ -76,11 +77,11 @@ func MakeLookupFunc(logf logger.Logf, netMon *netmon.Monitor) func(ctx context.C
 				metricRecursiveErrors.Add(1)
 				return
 			}
-			slices.SortFunc(addrs, func(a, b netip.Addr) bool { return a.Less(b) })
+			slices.SortFunc(addrs, netipx.CompareAddr)
 
 			// Wait for a response from the main function
 			oldAddrs := <-addrsCh
-			slices.SortFunc(oldAddrs, func(a, b netip.Addr) bool { return a.Less(b) })
+			slices.SortFunc(oldAddrs, netipx.CompareAddr)
 
 			matches := slices.Equal(addrs, oldAddrs)
 

net/tsaddr/tsaddr.go

@@ -10,6 +10,7 @@ import (
 	"net/netip"
 	"sync"
 
+	"go4.org/netipx"
 	"golang.org/x/exp/slices"
 	"tailscale.com/net/netaddr"
 )
@@ -252,12 +253,7 @@ func ExitRoutes() []netip.Prefix { return []netip.Prefix{allIPv4, allIPv6} }
 
 // SortPrefixes sorts the prefixes in place.
 func SortPrefixes(p []netip.Prefix) {
-	slices.SortFunc(p, func(ri, rj netip.Prefix) bool {
+	slices.SortFunc(p, netipx.ComparePrefix)
-		if ri.Addr() == rj.Addr() {
-			return ri.Bits() < rj.Bits()
-		}
-		return ri.Addr().Less(rj.Addr())
-	})
 }
 
 // FilterPrefixes returns a new slice, not aliasing in, containing elements of

util/cmpx/cmpx.go

@@ -20,3 +20,40 @@ func Or[T comparable](list ...T) T {
 	}
 	return zero
 }
+
+// Ordered is cmp.Ordered from Go 1.21.
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// Compare returns
+//
+//	-1 if x is less than y,
+//	 0 if x equals y,
+//	+1 if x is greater than y.
+//
+// For floating-point types, a NaN is considered less than any non-NaN,
+// a NaN is considered equal to a NaN, and -0.0 is equal to 0.0.
+func Compare[T Ordered](x, y T) int {
+	xNaN := isNaN(x)
+	yNaN := isNaN(y)
+	if xNaN && yNaN {
+		return 0
+	}
+	if xNaN || x < y {
+		return -1
+	}
+	if yNaN || x > y {
+		return +1
+	}
+	return 0
+}
+
+// isNaN reports whether x is a NaN without requiring the math package.
+// This will always return false if T is not floating-point.
+func isNaN[T Ordered](x T) bool {
+	return x != x
+}

wgengine/magicsock/magicsock_test.go

@@ -2438,11 +2438,11 @@ func TestEndpointTracker(t *testing.T) {
 		got := et.update(tt.now, tt.eps)
 
 		// Sort both arrays for comparison
-		slices.SortFunc(got, func(a, b tailcfg.Endpoint) bool {
+		slices.SortFunc(got, func(a, b tailcfg.Endpoint) int {
-			return a.Addr.String() < b.Addr.String()
+			return strings.Compare(a.Addr.String(), b.Addr.String())
 		})
-		slices.SortFunc(tt.want, func(a, b tailcfg.Endpoint) bool {
+		slices.SortFunc(tt.want, func(a, b tailcfg.Endpoint) int {
-			return a.Addr.String() < b.Addr.String()
+			return strings.Compare(a.Addr.String(), b.Addr.String())
 		})
 
 		if !reflect.DeepEqual(got, tt.want) {

wgengine/router/ifconfig_windows.go

@@ -396,7 +396,7 @@ func configureInterface(cfg *Config, tun *tun.NativeTun) (retErr error) {
 		return fmt.Errorf("syncAddresses: %w", err)
 	}
 
-	slices.SortFunc(routes, routeDataLess)
+	slices.SortFunc(routes, routeDataCompare)
 
 	deduplicatedRoutes := []*winipcfg.RouteData{}
 	for i := 0; i < len(routes); i++ {
@@ -652,8 +652,8 @@ func routeDataCompare(a, b *winipcfg.RouteData) int {
 func deltaRouteData(a, b []*winipcfg.RouteData) (add, del []*winipcfg.RouteData) {
 	add = make([]*winipcfg.RouteData, 0, len(b))
 	del = make([]*winipcfg.RouteData, 0, len(a))
-	slices.SortFunc(a, routeDataLess)
+	slices.SortFunc(a, routeDataCompare)
-	slices.SortFunc(b, routeDataLess)
+	slices.SortFunc(b, routeDataCompare)
 
 	i := 0
 	j := 0

wgengine/router/router_linux_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/tailscale/wireguard-go/tun"
 	"github.com/vishvananda/netlink"
+	"go4.org/netipx"
 	"golang.org/x/exp/slices"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/tsaddr"
@@ -1022,8 +1023,8 @@ func TestCIDRDiff(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		slices.SortFunc(added, func(a, b netip.Prefix) bool { return a.Addr().Less(b.Addr()) })
+		slices.SortFunc(added, netipx.ComparePrefix)
-		slices.SortFunc(deleted, func(a, b netip.Prefix) bool { return a.Addr().Less(b.Addr()) })
+		slices.SortFunc(deleted, netipx.ComparePrefix)
 		if !reflect.DeepEqual(added, tc.wantAdd) {
 			t.Errorf("added = %v, want %v", added, tc.wantAdd)
 		}