net: remove always-nil newFD error return value

newFD never returns an error on any of the platforms that define it.
Drop the always-nil error to simplify callers.

Change-Id: I727e95a0dac51ef70497ea1295276a8a6dce7f08
Reviewed-on: https://go-review.googlesource.com/c/go/+/764620
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: David Chase <drchase@google.com>

7 files changed, 15 insertions, 31 deletions

diff --git a/src/net/fd_plan9.go b/src/net/fd_plan9.go
index 66a12e7d7d..8c70c7546d 100644
--- a/src/net/fd_plan9.go
+++ b/src/net/fd_plan9.go
@@ -27,7 +27,7 @@ type netFD struct {
 
 var netdir = "/net" // default network
 
-func newFD(net, name string, listen, ctl, data *os.File, laddr, raddr Addr) (*netFD, error) {
+func newFD(net, name string, listen, ctl, data *os.File, laddr, raddr Addr) *netFD {
 	ret := &netFD{
 		net:    net,
 		n:      name,
@@ -38,7 +38,7 @@ func newFD(net, name string, listen, ctl, data *os.File, laddr, raddr Addr) (*ne
 		raddr: raddr,
 	}
 	ret.pfd.Destroy = ret.destroy
-	return ret, nil
+	return ret
 }
 
 func (fd *netFD) init() error {
diff --git a/src/net/fd_unix.go b/src/net/fd_unix.go
index 0d4303e2cc..e16eeabb61 100644
--- a/src/net/fd_unix.go
+++ b/src/net/fd_unix.go
@@ -23,8 +23,8 @@ const (
 	writeMsgSyscallName = "sendmsg"
 )
 
-func newFD(sysfd, family, sotype int, net string) (*netFD, error) {
-	ret := &netFD{
+func newFD(sysfd, family, sotype int, net string) *netFD {
+	return &netFD{
 		pfd: poll.FD{
 			Sysfd:         sysfd,
 			IsStream:      sotype == syscall.SOCK_STREAM,
@@ -34,7 +34,6 @@ func newFD(sysfd, family, sotype int, net string) (*netFD, error) {
 		sotype: sotype,
 		net:    net,
 	}
-	return ret, nil
 }
 
 func (fd *netFD) init() error {
@@ -155,10 +154,7 @@ func (fd *netFD) accept() (netfd *netFD, err error) {
 		return nil, err
 	}
 
-	if netfd, err = newFD(d, fd.family, fd.sotype, fd.net); err != nil {
-		poll.CloseFunc(d)
-		return nil, err
-	}
+	netfd = newFD(d, fd.family, fd.sotype, fd.net)
 	if err = netfd.init(); err != nil {
 		netfd.Close()
 		return nil, err
diff --git a/src/net/fd_windows.go b/src/net/fd_windows.go
index c28ce045c4..8568879602 100644
--- a/src/net/fd_windows.go
+++ b/src/net/fd_windows.go
@@ -38,8 +38,8 @@ func canUseConnectEx(net string) bool {
 	return false
 }
 
-func newFD(sysfd syscall.Handle, family, sotype int, net string) (*netFD, error) {
-	ret := &netFD{
+func newFD(sysfd syscall.Handle, family, sotype int, net string) *netFD {
+	return &netFD{
 		pfd: poll.FD{
 			Sysfd:         sysfd,
 			IsStream:      sotype == syscall.SOCK_STREAM,
@@ -49,7 +49,6 @@ func newFD(sysfd syscall.Handle, family, sotype int, net string) (*netFD, error)
 		sotype: sotype,
 		net:    net,
 	}
-	return ret, nil
 }
 
 func (fd *netFD) init() error {
@@ -211,11 +210,7 @@ func (fd *netFD) accept() (*netFD, error) {
 	}
 
 	// Associate our new socket with IOCP.
-	netfd, err := newFD(s, fd.family, fd.sotype, fd.net)
-	if err != nil {
-		poll.CloseFunc(s)
-		return nil, err
-	}
+	netfd := newFD(s, fd.family, fd.sotype, fd.net)
 	if err := netfd.init(); err != nil {
 		fd.Close()
 		return nil, err
diff --git a/src/net/file_plan9.go b/src/net/file_plan9.go
index 6c2151c409..1684e5ca18 100644
--- a/src/net/file_plan9.go
+++ b/src/net/file_plan9.go
@@ -81,7 +81,7 @@ func newFileFD(f *os.File) (net *netFD, err error) {
 	if err != nil {
 		return nil, err
 	}
-	return newFD(comp[1], name, nil, ctl, nil, laddr, nil)
+	return newFD(comp[1], name, nil, ctl, nil, laddr, nil), nil
 }
 
 func fileConn(f *os.File) (Conn, error) {
diff --git a/src/net/file_posix.go b/src/net/file_posix.go
index b28ff5845d..de71ca15ec 100644
--- a/src/net/file_posix.go
+++ b/src/net/file_posix.go
@@ -40,11 +40,7 @@ func newFileFD(f *os.File) (*netFD, error) {
 		poll.CloseFunc(s)
 		return nil, syscall.EPROTONOSUPPORT
 	}
-	fd, err := newFD(s, family, sotype, "")
-	if err != nil {
-		poll.CloseFunc(s)
-		return nil, err
-	}
+	fd := newFD(s, family, sotype, "")
 	laddr := fd.addrFunc()(lsa)
 	raddr := fd.addrFunc()(rsa)
 	fd.net = laddr.Network()
diff --git a/src/net/ipsock_plan9.go b/src/net/ipsock_plan9.go
index 2bd5071d56..9cdc15cdf1 100644
--- a/src/net/ipsock_plan9.go
+++ b/src/net/ipsock_plan9.go
@@ -227,7 +227,7 @@ func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *
 		f.Close()
 		return nil, err
 	}
-	return newFD(proto, name, nil, f, data, laddr, raddr)
+	return newFD(proto, name, nil, f, data, laddr, raddr), nil
 }
 
 func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err error) {
@@ -246,11 +246,11 @@ func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err er
 		f.Close()
 		return nil, err
 	}
-	return newFD(proto, name, nil, f, nil, laddr, nil)
+	return newFD(proto, name, nil, f, nil, laddr, nil), nil
 }
 
 func (fd *netFD) netFD() (*netFD, error) {
-	return newFD(fd.net, fd.n, fd.listen, fd.ctl, fd.data, fd.laddr, fd.raddr)
+	return newFD(fd.net, fd.n, fd.listen, fd.ctl, fd.data, fd.laddr, fd.raddr), nil
 }
 
 func (fd *netFD) acceptPlan9() (nfd *netFD, err error) {
@@ -288,7 +288,7 @@ func (fd *netFD) acceptPlan9() (nfd *netFD, err error) {
 		data.Close()
 		return nil, err
 	}
-	return newFD(fd.net, name, listen, ctl, data, fd.laddr, raddr)
+	return newFD(fd.net, name, listen, ctl, data, fd.laddr, raddr), nil
 }
 
 func isWildcard(a Addr) bool {
diff --git a/src/net/sock_posix.go b/src/net/sock_posix.go
index d04c26e7ef..cc812e3137 100644
--- a/src/net/sock_posix.go
+++ b/src/net/sock_posix.go
@@ -24,10 +24,7 @@ func socket(ctx context.Context, net string, family, sotype, proto int, ipv6only
 		poll.CloseFunc(s)
 		return nil, err
 	}
-	if fd, err = newFD(s, family, sotype, net); err != nil {
-		poll.CloseFunc(s)
-		return nil, err
-	}
+	fd = newFD(s, family, sotype, net)
 
 	// This function makes a network file descriptor for the
 	// following applications: