util/cmpx: remove code that's in the stdlib now

The cmpx.Compare function (and associated interface) are now available
in the standard library as cmp.Compare. Remove our version of it and use
the version from the standard library.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I4be3ac63d466c05eb7a0babb25cb0d41816fbd53

cmd/derper/depaware.txt

@@ -193,7 +193,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         golang.org/x/time/rate                                       from tailscale.com/cmd/derper+
         bufio                                                        from compress/flate+
         bytes                                                        from bufio+
-        cmp                                                          from slices
+        cmp                                                          from slices+
         compress/flate                                               from compress/gzip+
         compress/gzip                                                from internal/profile+
         container/list                                               from crypto/tls+

cmd/netlogfmt/main.go

@@ -25,6 +25,7 @@
 package main
 
 import (
+	"cmp"
 	"encoding/base64"
 	"encoding/json"
 	"flag"
@@ -45,7 +46,6 @@ import (
 	"github.com/go-json-experiment/json/jsontext"
 	"tailscale.com/types/logid"
 	"tailscale.com/types/netlogtype"
-	"tailscale.com/util/cmpx"
 	"tailscale.com/util/must"
 )
 
@@ -155,7 +155,7 @@ func printMessage(msg message) {
 		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 cmpx.Compare(ny, nx)
+			return cmp.Compare(ny, nx)
 		})
 		var sum netlogtype.Counts
 		for _, cc := range traffic {

cmd/tailscale/cli/exitnode.go

@@ -4,6 +4,7 @@
 package cli
 
 import (
+	"cmp"
 	"context"
 	"errors"
 	"flag"
@@ -17,7 +18,6 @@ import (
 	xmaps "golang.org/x/exp/maps"
 	"tailscale.com/ipn/ipnstate"
 	"tailscale.com/tailcfg"
-	"tailscale.com/util/cmpx"
 )
 
 var exitNodeCmd = &ffcli.Command{
@@ -228,7 +228,7 @@ func filterFormatAndSortExitNodes(peers []*ipnstate.PeerStatus, filterBy string)
 // by location.Priority, in order of highest priority.
 func sortPeersByPriority(peers []*ipnstate.PeerStatus) {
 	slices.SortStableFunc(peers, func(a, b *ipnstate.PeerStatus) int {
-		return cmpx.Compare(b.Location.Priority, a.Location.Priority)
+		return cmp.Compare(b.Location.Priority, a.Location.Priority)
 	})
 }
 

ipn/ipnlocal/local.go

@@ -4,6 +4,7 @@
 package ipnlocal
 
 import (
+	"cmp"
 	"context"
 	"encoding/base64"
 	"encoding/json"
@@ -1332,7 +1333,7 @@ func (b *LocalBackend) UpdateNetmapDelta(muts []netmap.NodeMutation) (handled bo
 			nm.Peers = append(nm.Peers, p)
 		}
 		slices.SortFunc(nm.Peers, func(a, b tailcfg.NodeView) int {
-			return cmpx.Compare(a.ID(), b.ID())
+			return cmp.Compare(a.ID(), b.ID())
 		})
 		notify = &ipn.Notify{NetMap: nm}
 	} else if testenv.InTest() {
@@ -1549,7 +1550,7 @@ func (b *LocalBackend) PeersForTest() []tailcfg.NodeView {
 	defer b.mu.Unlock()
 	ret := xmaps.Values(b.peers)
 	slices.SortFunc(ret, func(a, b tailcfg.NodeView) int {
-		return cmpx.Compare(a.ID(), b.ID())
+		return cmp.Compare(a.ID(), b.ID())
 	})
 	return ret
 }
@@ -4904,7 +4905,7 @@ func (b *LocalBackend) FileTargets() ([]*apitype.FileTarget, error) {
 		})
 	}
 	slices.SortFunc(ret, func(a, b *apitype.FileTarget) int {
-		return cmpx.Compare(a.Node.Name, b.Node.Name)
+		return cmp.Compare(a.Node.Name, b.Node.Name)
 	})
 	return ret, nil
 }

ipn/ipnlocal/profiles.go

@@ -4,6 +4,7 @@
 package ipnlocal
 
 import (
+	"cmp"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -17,7 +18,6 @@ import (
 	"tailscale.com/ipn"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/clientmetric"
-	"tailscale.com/util/cmpx"
 )
 
 var errAlreadyMigrated = errors.New("profile migration already completed")
@@ -113,7 +113,7 @@ func (pm *profileManager) allProfiles() (out []*ipn.LoginProfile) {
 		}
 	}
 	slices.SortFunc(out, func(a, b *ipn.LoginProfile) int {
-		return cmpx.Compare(a.Name, b.Name)
+		return cmp.Compare(a.Name, b.Name)
 	})
 	return out
 }

types/netmap/netmap.go

@@ -5,6 +5,7 @@
 package netmap
 
 import (
+	"cmp"
 	"encoding/json"
 	"fmt"
 	"net/netip"
@@ -16,7 +17,6 @@ import (
 	"tailscale.com/tka"
 	"tailscale.com/types/key"
 	"tailscale.com/types/views"
-	"tailscale.com/util/cmpx"
 	"tailscale.com/wgengine/filter"
 )
 
@@ -146,7 +146,7 @@ func (nm *NetworkMap) PeerIndexByNodeID(nodeID tailcfg.NodeID) int {
 		return -1
 	}
 	idx, ok := sort.Find(len(nm.Peers), func(i int) int {
-		return cmpx.Compare(nodeID, nm.Peers[i].ID())
+		return cmp.Compare(nodeID, nm.Peers[i].ID())
 	})
 	if !ok {
 		return -1

types/netmap/nodemut.go

@@ -4,6 +4,7 @@
 package netmap
 
 import (
+	"cmp"
 	"fmt"
 	"net/netip"
 	"reflect"
@@ -13,7 +14,6 @@ import (
 
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/ptr"
-	"tailscale.com/util/cmpx"
 )
 
 // NodeMutation is the common interface for types that describe
@@ -139,7 +139,7 @@ func MutationsFromMapResponse(res *tailcfg.MapResponse, now time.Time) (ret []No
 		}
 	}
 	slices.SortStableFunc(ret, func(a, b NodeMutation) int {
-		return cmpx.Compare(a.NodeIDBeingMutated(), b.NodeIDBeingMutated())
+		return cmp.Compare(a.NodeIDBeingMutated(), b.NodeIDBeingMutated())
 	})
 	return ret, true
 }

util/cmpx/cmpx.go

@@ -20,40 +20,3 @@ 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
-}