libgo: update to Go1.18beta2

gotools/
	* Makefile.am (go_cmd_cgo_files): Add ast_go118.go
	(check-go-tool): Copy golang.org/x/tools directories.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/384695

1 files changed, 62 insertions, 20 deletions

diff --git a/libgo/go/net/lookup.go b/libgo/go/net/lookup.go
index d350ef7..c7b8dc6 100644
--- a/libgo/go/net/lookup.go
+++ b/libgo/go/net/lookup.go
@@ -8,6 +8,7 @@ import (
 	"context"
 	"internal/nettrace"
 	"internal/singleflight"
+	"net/netip"
 	"sync"
 )
 
@@ -232,6 +233,28 @@ func (r *Resolver) LookupIP(ctx context.Context, network, host string) ([]IP, er
 	return ips, nil
 }
 
+// LookupNetIP looks up host using the local resolver.
+// It returns a slice of that host's IP addresses of the type specified by
+// network.
+// The network must be one of "ip", "ip4" or "ip6".
+func (r *Resolver) LookupNetIP(ctx context.Context, network, host string) ([]netip.Addr, error) {
+	// TODO(bradfitz): make this efficient, making the internal net package
+	// type throughout be netip.Addr and only converting to the net.IP slice
+	// version at the edge. But for now (2021-10-20), this is a wrapper around
+	// the old way.
+	ips, err := r.LookupIP(ctx, network, host)
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]netip.Addr, 0, len(ips))
+	for _, ip := range ips {
+		if a, ok := netip.AddrFromSlice(ip); ok {
+			ret = append(ret, a)
+		}
+	}
+	return ret, nil
+}
+
 // onlyValuesCtx is a context that uses an underlying context
 // for value lookup if the underlying context hasn't yet expired.
 type onlyValuesCtx struct {
@@ -242,7 +265,7 @@ type onlyValuesCtx struct {
 var _ context.Context = (*onlyValuesCtx)(nil)
 
 // Value performs a lookup if the original context hasn't expired.
-func (ovc *onlyValuesCtx) Value(key interface{}) interface{} {
+func (ovc *onlyValuesCtx) Value(key any) any {
 	select {
 	case <-ovc.lookupValues.Done():
 		return nil
@@ -291,7 +314,7 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 
 	lookupKey := network + "\000" + host
 	dnsWaitGroup.Add(1)
-	ch, called := r.getLookupGroup().DoChan(lookupKey, func() (interface{}, error) {
+	ch, called := r.getLookupGroup().DoChan(lookupKey, func() (any, error) {
 		defer dnsWaitGroup.Done()
 		return testHookLookupIP(lookupGroupCtx, resolverFunc, network, host)
 	})
@@ -316,24 +339,45 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 				lookupGroupCancel()
 			}()
 		}
-		err := mapErr(ctx.Err())
+		ctxErr := ctx.Err()
+		err := &DNSError{
+			Err:       mapErr(ctxErr).Error(),
+			Name:      host,
+			IsTimeout: ctxErr == context.DeadlineExceeded,
+		}
 		if trace != nil && trace.DNSDone != nil {
 			trace.DNSDone(nil, false, err)
 		}
 		return nil, err
 	case r := <-ch:
 		lookupGroupCancel()
+		err := r.Err
+		if err != nil {
+			if _, ok := err.(*DNSError); !ok {
+				isTimeout := false
+				if err == context.DeadlineExceeded {
+					isTimeout = true
+				} else if terr, ok := err.(timeout); ok {
+					isTimeout = terr.Timeout()
+				}
+				err = &DNSError{
+					Err:       err.Error(),
+					Name:      host,
+					IsTimeout: isTimeout,
+				}
+			}
+		}
 		if trace != nil && trace.DNSDone != nil {
 			addrs, _ := r.Val.([]IPAddr)
-			trace.DNSDone(ipAddrsEface(addrs), r.Shared, r.Err)
+			trace.DNSDone(ipAddrsEface(addrs), r.Shared, err)
 		}
-		return lookupIPReturn(r.Val, r.Err, r.Shared)
+		return lookupIPReturn(r.Val, err, r.Shared)
 	}
 }
 
 // lookupIPReturn turns the return values from singleflight.Do into
 // the return values from LookupIP.
-func lookupIPReturn(addrsi interface{}, err error, shared bool) ([]IPAddr, error) {
+func lookupIPReturn(addrsi any, err error, shared bool) ([]IPAddr, error) {
 	if err != nil {
 		return nil, err
 	}
@@ -347,8 +391,8 @@ func lookupIPReturn(addrsi interface{}, err error, shared bool) ([]IPAddr, error
 }
 
 // ipAddrsEface returns an empty interface slice of addrs.
-func ipAddrsEface(addrs []IPAddr) []interface{} {
-	s := make([]interface{}, len(addrs))
+func ipAddrsEface(addrs []IPAddr) []any {
+	s := make([]any, len(addrs))
 	for i, v := range addrs {
 		s[i] = v
 	}
@@ -442,7 +486,7 @@ func (r *Resolver) LookupCNAME(ctx context.Context, host string) (string, error)
 // The returned service names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err error) {
 	return DefaultResolver.LookupSRV(context.Background(), service, proto, name)
 }
@@ -460,7 +504,7 @@ func LookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
 // The returned service names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV, error) {
 	cname, addrs, err := r.lookupSRV(ctx, service, proto, name)
 	if err != nil {
@@ -490,7 +534,7 @@ func (r *Resolver) LookupSRV(ctx context.Context, service, proto, name string) (
 // The returned mail server names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 //
 // LookupMX uses context.Background internally; to specify the context, use
 // Resolver.LookupMX.
@@ -503,7 +547,7 @@ func LookupMX(name string) ([]*MX, error) {
 // The returned mail server names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
 	records, err := r.lookupMX(ctx, name)
 	if err != nil {
@@ -514,9 +558,7 @@ func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
 		if mx == nil {
 			continue
 		}
-		// Bypass the hostname validity check for targets which contain only a dot,
-		// as this is used to represent a 'Null' MX record.
-		if mx.Host != "." && !isDomainName(mx.Host) {
+		if !isDomainName(mx.Host) {
 			continue
 		}
 		filteredMX = append(filteredMX, mx)
@@ -532,7 +574,7 @@ func (r *Resolver) LookupMX(ctx context.Context, name string) ([]*MX, error) {
 // The returned name server names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 //
 // LookupNS uses context.Background internally; to specify the context, use
 // Resolver.LookupNS.
@@ -545,7 +587,7 @@ func LookupNS(name string) ([]*NS, error) {
 // The returned name server names are validated to be properly
 // formatted presentation-format domain names. If the response contains
 // invalid names, those records are filtered out and an error
-// will be returned alongside the the remaining results, if any.
+// will be returned alongside the remaining results, if any.
 func (r *Resolver) LookupNS(ctx context.Context, name string) ([]*NS, error) {
 	records, err := r.lookupNS(ctx, name)
 	if err != nil {
@@ -585,7 +627,7 @@ func (r *Resolver) LookupTXT(ctx context.Context, name string) ([]string, error)
 //
 // The returned names are validated to be properly formatted presentation-format
 // domain names. If the response contains invalid names, those records are filtered
-// out and an error will be returned alongside the the remaining results, if any.
+// out and an error will be returned alongside the remaining results, if any.
 //
 // When using the host C library resolver, at most one result will be
 // returned. To bypass the host resolver, use a custom Resolver.
@@ -601,7 +643,7 @@ func LookupAddr(addr string) (names []string, err error) {
 //
 // The returned names are validated to be properly formatted presentation-format
 // domain names. If the response contains invalid names, those records are filtered
-// out and an error will be returned alongside the the remaining results, if any.
+// out and an error will be returned alongside the remaining results, if any.
 func (r *Resolver) LookupAddr(ctx context.Context, addr string) ([]string, error) {
 	names, err := r.lookupAddr(ctx, addr)
 	if err != nil {
@@ -620,6 +662,6 @@ func (r *Resolver) LookupAddr(ctx context.Context, addr string) ([]string, error
 }
 
 // errMalformedDNSRecordsDetail is the DNSError detail which is returned when a Resolver.Lookup...
-// method recieves DNS records which contain invalid DNS names. This may be returned alongside
+// method receives DNS records which contain invalid DNS names. This may be returned alongside
 // results which have had the malformed records filtered out.
 var errMalformedDNSRecordsDetail = "DNS response contained records which contain invalid names"