libgo: update to Go 1.8 release candidate 1

    
    Compiler changes:
      * Change map assignment to use mapassign and assign value directly.
      * Change string iteration to use decoderune, faster for ASCII strings.
      * Change makeslice to take int, and use makeslice64 for larger values.
      * Add new noverflow field to hmap struct used for maps.
    
    Unresolved problems, to be fixed later:
      * Commented out test in go/types/sizes_test.go that doesn't compile.
      * Commented out reflect.TestStructOf test for padding after zero-sized field.
    
    Reviewed-on: https://go-review.googlesource.com/35231

gotools/:
	Updates for Go 1.8rc1.
	* Makefile.am (go_cmd_go_files): Add bug.go.
	(s-zdefaultcc): Write defaultPkgConfig.
	* Makefile.in: Rebuild.

From-SVN: r244456

1 files changed, 27 insertions, 25 deletions

diff --git a/libgo/go/net/lookup_unix.go b/libgo/go/net/lookup_unix.go
index 15397e8..be2ced9 100644
--- a/libgo/go/net/lookup_unix.go
+++ b/libgo/go/net/lookup_unix.go
@@ -26,7 +26,7 @@ func readProtocols() {
 			if len(f) < 2 {
 				continue
 			}
-			if proto, _, ok := dtoi(f[1], 0); ok {
+			if proto, _, ok := dtoi(f[1]); ok {
 				if _, ok := protocols[f[0]]; !ok {
 					protocols[f[0]] = proto
 				}
@@ -45,16 +45,12 @@ func readProtocols() {
 // returns correspondent protocol number.
 func lookupProtocol(_ context.Context, name string) (int, error) {
 	onceReadProtocols.Do(readProtocols)
-	proto, found := protocols[name]
-	if !found {
-		return 0, &AddrError{Err: "unknown IP protocol specified", Addr: name}
-	}
-	return proto, nil
+	return lookupProtocolMap(name)
 }
 
-func lookupHost(ctx context.Context, host string) (addrs []string, err error) {
+func (r *Resolver) lookupHost(ctx context.Context, host string) (addrs []string, err error) {
 	order := systemConf().hostLookupOrder(host)
-	if order == hostLookupCgo {
+	if !r.PreferGo && order == hostLookupCgo {
 		if addrs, err, ok := cgoLookupHost(ctx, host); ok {
 			return addrs, err
 		}
@@ -64,7 +60,10 @@ func lookupHost(ctx context.Context, host string) (addrs []string, err error) {
 	return goLookupHostOrder(ctx, host, order)
 }
 
-func lookupIP(ctx context.Context, host string) (addrs []IPAddr, err error) {
+func (r *Resolver) lookupIP(ctx context.Context, host string) (addrs []IPAddr, err error) {
+	if r.PreferGo {
+		return goLookupIP(ctx, host)
+	}
 	order := systemConf().hostLookupOrder(host)
 	if order == hostLookupCgo {
 		if addrs, err, ok := cgoLookupIP(ctx, host); ok {
@@ -73,25 +72,28 @@ func lookupIP(ctx context.Context, host string) (addrs []IPAddr, err error) {
 		// cgo not available (or netgo); fall back to Go's DNS resolver
 		order = hostLookupFilesDNS
 	}
-	return goLookupIPOrder(ctx, host, order)
+	addrs, _, err = goLookupIPCNAMEOrder(ctx, host, order)
+	return
 }
 
-func lookupPort(ctx context.Context, network, service string) (int, error) {
-	// TODO: use the context if there ever becomes a need. Related
-	// is issue 15321. But port lookup generally just involves
-	// local files, and the os package has no context support. The
-	// files might be on a remote filesystem, though. This should
-	// probably race goroutines if ctx != context.Background().
-	if systemConf().canUseCgo() {
+func (r *Resolver) lookupPort(ctx context.Context, network, service string) (int, error) {
+	if !r.PreferGo && systemConf().canUseCgo() {
 		if port, err, ok := cgoLookupPort(ctx, network, service); ok {
+			if err != nil {
+				// Issue 18213: if cgo fails, first check to see whether we
+				// have the answer baked-in to the net package.
+				if port, err := goLookupPort(network, service); err == nil {
+					return port, nil
+				}
+			}
 			return port, err
 		}
 	}
 	return goLookupPort(network, service)
 }
 
-func lookupCNAME(ctx context.Context, name string) (string, error) {
-	if systemConf().canUseCgo() {
+func (r *Resolver) lookupCNAME(ctx context.Context, name string) (string, error) {
+	if !r.PreferGo && systemConf().canUseCgo() {
 		if cname, err, ok := cgoLookupCNAME(ctx, name); ok {
 			return cname, err
 		}
@@ -99,7 +101,7 @@ func lookupCNAME(ctx context.Context, name string) (string, error) {
 	return goLookupCNAME(ctx, name)
 }
 
-func lookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV, error) {
+func (*Resolver) lookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV, error) {
 	var target string
 	if service == "" && proto == "" {
 		target = name
@@ -119,7 +121,7 @@ func lookupSRV(ctx context.Context, service, proto, name string) (string, []*SRV
 	return cname, srvs, nil
 }
 
-func lookupMX(ctx context.Context, name string) ([]*MX, error) {
+func (*Resolver) lookupMX(ctx context.Context, name string) ([]*MX, error) {
 	_, rrs, err := lookup(ctx, name, dnsTypeMX)
 	if err != nil {
 		return nil, err
@@ -133,7 +135,7 @@ func lookupMX(ctx context.Context, name string) ([]*MX, error) {
 	return mxs, nil
 }
 
-func lookupNS(ctx context.Context, name string) ([]*NS, error) {
+func (*Resolver) lookupNS(ctx context.Context, name string) ([]*NS, error) {
 	_, rrs, err := lookup(ctx, name, dnsTypeNS)
 	if err != nil {
 		return nil, err
@@ -145,7 +147,7 @@ func lookupNS(ctx context.Context, name string) ([]*NS, error) {
 	return nss, nil
 }
 
-func lookupTXT(ctx context.Context, name string) ([]string, error) {
+func (r *Resolver) lookupTXT(ctx context.Context, name string) ([]string, error) {
 	_, rrs, err := lookup(ctx, name, dnsTypeTXT)
 	if err != nil {
 		return nil, err
@@ -157,8 +159,8 @@ func lookupTXT(ctx context.Context, name string) ([]string, error) {
 	return txts, nil
 }
 
-func lookupAddr(ctx context.Context, addr string) ([]string, error) {
-	if systemConf().canUseCgo() {
+func (r *Resolver) lookupAddr(ctx context.Context, addr string) ([]string, error) {
+	if !r.PreferGo && systemConf().canUseCgo() {
 		if ptrs, err, ok := cgoLookupPTR(ctx, addr); ok {
 			return ptrs, err
 		}