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, 11 insertions, 3 deletions

diff --git a/libgo/go/net/unixsock.go b/libgo/go/net/unixsock.go
index bacdaa41d90..b25d492f591 100644
--- a/libgo/go/net/unixsock.go
+++ b/libgo/go/net/unixsock.go
@@ -7,6 +7,7 @@ package net
 import (
 	"context"
 	"os"
+	"sync"
 	"syscall"
 	"time"
 )
@@ -120,6 +121,9 @@ func (c *UnixConn) ReadFrom(b []byte) (int, Addr, error) {
 // the associated out-of-band data into oob. It returns the number of
 // bytes copied into b, the number of bytes copied into oob, the flags
 // that were set on the packet, and the source address of the packet.
+//
+// Note that if len(b) == 0 and len(oob) > 0, this function will still
+// read (and discard) 1 byte from the connection.
 func (c *UnixConn) ReadMsgUnix(b, oob []byte) (n, oobn, flags int, addr *UnixAddr, err error) {
 	if !c.ok() {
 		return 0, 0, 0, nil, syscall.EINVAL
@@ -167,6 +171,9 @@ func (c *UnixConn) WriteTo(b []byte, addr Addr) (int, error) {
 // WriteMsgUnix writes a packet to addr via c, copying the payload
 // from b and the associated out-of-band data from oob. It returns
 // the number of payload and out-of-band bytes written.
+//
+// Note that if len(b) == 0 and len(oob) > 0, this function will still
+// write 1 byte to the connection.
 func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err error) {
 	if !c.ok() {
 		return 0, 0, syscall.EINVAL
@@ -200,9 +207,10 @@ func DialUnix(net string, laddr, raddr *UnixAddr) (*UnixConn, error) {
 // typically use variables of type Listener instead of assuming Unix
 // domain sockets.
 type UnixListener struct {
-	fd     *netFD
-	path   string
-	unlink bool
+	fd         *netFD
+	path       string
+	unlink     bool
+	unlinkOnce sync.Once
 }
 
 func (ln *UnixListener) ok() bool { return ln != nil && ln.fd != nil }