net: move test flags into main_test.go

Also updates the comments on test flags.

Change-Id: I8dbd90270e08728ab309ab88a3030e0f8e547175
Reviewed-on: https://go-review.googlesource.com/8394
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/net/dial_test.go

@@ -6,7 +6,6 @@ package net
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
 	"io"
 	"os"
@@ -77,8 +76,6 @@ func TestSelfConnect(t *testing.T) {
 	}
 }
 
-var runErrorTest = flag.Bool("run_error_test", false, "let TestDialError check for dns errors")
-
 type DialErrorTest struct {
 	Net     string
 	Raddr   string

src/net/dialgoogle_test.go

@@ -5,7 +5,6 @@
 package net
 
 import (
-	"flag"
 	"fmt"
 	"io"
 	"strings"
@@ -13,9 +12,6 @@ import (
 	"testing"
 )
 
-// If an IPv6 tunnel is running, we can try dialing a real IPv6 address.
-var testIPv6 = flag.Bool("ipv6", false, "assume ipv6 tunnel is present")
-
 func TestResolveGoogle(t *testing.T) {
 	if testing.Short() || !*testExternal {
 		t.Skip("skipping test to avoid external network")

src/net/lookup_test.go

@@ -8,15 +8,12 @@
 package net
 
 import (
-	"flag"
 	"fmt"
 	"strings"
 	"testing"
 	"time"
 )
 
-var testExternal = flag.Bool("external", true, "allow use of external networks during long test")
-
 var lookupGoogleSRVTests = []struct {
 	service, proto, name string
 	cname, target        string
@@ -232,8 +229,6 @@ func TestReverseAddress(t *testing.T) {
 	}
 }
 
-var testDNSFlood = flag.Bool("dnsflood", false, "whether to test dns query flooding")
-
 func TestLookupIPDeadline(t *testing.T) {
 	if !*testDNSFlood {
 		t.Skip("test disabled; use -dnsflood to enable")

src/net/main_test.go

@@ -5,6 +5,7 @@
 package net
 
 import (
+	"flag"
 	"fmt"
 	"net/internal/socktest"
 	"os"
@@ -22,6 +23,26 @@ var (
 	testHookUninstaller sync.Once
 )
 
+var (
+	// Do not test datagrams with empty payload by default.
+	// It depends on each platform implementation whether generic
+	// read, socket recv system calls return the result of zero
+	// byte read.
+	testDatagram = flag.Bool("datagram", false, "whether to test UDP and unixgram")
+
+	testDNSFlood = flag.Bool("dnsflood", false, "whether to test DNS query flooding")
+
+	testExternal = flag.Bool("external", true, "allow use of external networks during long test")
+
+	// If external IPv6 connectivity exists, we can try dialing
+	// non-node/interface local scope IPv6 addresses.
+	testIPv6 = flag.Bool("ipv6", false, "assume external IPv6 connectivity exists")
+
+	// BUG: TestDialError has been broken, and so this flag
+	// exists. We should fix the test and remove this flag soon.
+	runErrorTest = flag.Bool("run_error_test", false, "let TestDialError check for DNS errors")
+)
+
 func TestMain(m *testing.M) {
 	installTestHooks()
 

src/net/server_test.go

@@ -5,7 +5,6 @@
 package net
 
 import (
-	"flag"
 	"io"
 	"os"
 	"testing"
@@ -201,12 +200,6 @@ func runStreamConnClient(t *testing.T, net, taddr string, isEmpty bool) {
 	}
 }
 
-// Do not test empty datagrams by default.
-// It causes unexplained timeouts on some systems,
-// including Snow Leopard.  I think that the kernel
-// doesn't quite expect them.
-var testDatagram = flag.Bool("datagram", false, "whether to test udp and unixgram")
-
 var datagramPacketConnServerTests = []struct {
 	snet  string // server side
 	saddr string