[dev.boringcrypto] all: merge master (nearly Go 1.10 beta 1) into dev.boringcrypto

This is a git merge of master into dev.boringcrypto.

The branch was previously based on release-branch.go1.9,
so there are a handful of spurious conflicts that would
also arise if trying to merge master into release-branch.go1.9
(which we never do). Those have all been resolved by taking
the original file from master, discarding any Go 1.9-specific
edits.

all.bash passes on darwin/amd64, which is to say without
actually using BoringCrypto.

Go 1.10-related fixes to BoringCrypto itself will be in a followup CL.
This CL is just the merge.

Change-Id: I4c97711fec0fb86761913dcde28d25c001246c35

10 files changed, 87 insertions, 0 deletions

diff --git a/src/runtime/race/testdata/atomic_test.go b/src/runtime/race/testdata/atomic_test.go
index 232744b3dd..769c8d7398 100644
--- a/src/runtime/race/testdata/atomic_test.go
+++ b/src/runtime/race/testdata/atomic_test.go
@@ -14,6 +14,7 @@ import (
 
 func TestNoRaceAtomicAddInt64(t *testing.T) {
 	var x1, x2 int8
+	_ = x1 + x2
 	var s int64
 	ch := make(chan bool, 2)
 	go func() {
@@ -36,6 +37,7 @@ func TestNoRaceAtomicAddInt64(t *testing.T) {
 
 func TestRaceAtomicAddInt64(t *testing.T) {
 	var x1, x2 int8
+	_ = x1 + x2
 	var s int64
 	ch := make(chan bool, 2)
 	go func() {
@@ -58,6 +60,7 @@ func TestRaceAtomicAddInt64(t *testing.T) {
 
 func TestNoRaceAtomicAddInt32(t *testing.T) {
 	var x1, x2 int8
+	_ = x1 + x2
 	var s int32
 	ch := make(chan bool, 2)
 	go func() {
@@ -80,6 +83,7 @@ func TestNoRaceAtomicAddInt32(t *testing.T) {
 
 func TestNoRaceAtomicLoadAddInt32(t *testing.T) {
 	var x int64
+	_ = x
 	var s int32
 	go func() {
 		x = 2
@@ -93,6 +97,7 @@ func TestNoRaceAtomicLoadAddInt32(t *testing.T) {
 
 func TestNoRaceAtomicLoadStoreInt32(t *testing.T) {
 	var x int64
+	_ = x
 	var s int32
 	go func() {
 		x = 2
@@ -106,6 +111,7 @@ func TestNoRaceAtomicLoadStoreInt32(t *testing.T) {
 
 func TestNoRaceAtomicStoreCASInt32(t *testing.T) {
 	var x int64
+	_ = x
 	var s int32
 	go func() {
 		x = 2
@@ -119,6 +125,7 @@ func TestNoRaceAtomicStoreCASInt32(t *testing.T) {
 
 func TestNoRaceAtomicCASLoadInt32(t *testing.T) {
 	var x int64
+	_ = x
 	var s int32
 	go func() {
 		x = 2
@@ -134,6 +141,7 @@ func TestNoRaceAtomicCASLoadInt32(t *testing.T) {
 
 func TestNoRaceAtomicCASCASInt32(t *testing.T) {
 	var x int64
+	_ = x
 	var s int32
 	go func() {
 		x = 2
@@ -149,6 +157,7 @@ func TestNoRaceAtomicCASCASInt32(t *testing.T) {
 
 func TestNoRaceAtomicCASCASInt32_2(t *testing.T) {
 	var x1, x2 int8
+	_ = x1 + x2
 	var s int32
 	ch := make(chan bool, 2)
 	go func() {
@@ -171,6 +180,7 @@ func TestNoRaceAtomicCASCASInt32_2(t *testing.T) {
 
 func TestNoRaceAtomicLoadInt64(t *testing.T) {
 	var x int32
+	_ = x
 	var s int64
 	go func() {
 		x = 2
@@ -184,6 +194,7 @@ func TestNoRaceAtomicLoadInt64(t *testing.T) {
 
 func TestNoRaceAtomicCASCASUInt64(t *testing.T) {
 	var x int64
+	_ = x
 	var s uint64
 	go func() {
 		x = 2
@@ -199,6 +210,7 @@ func TestNoRaceAtomicCASCASUInt64(t *testing.T) {
 
 func TestNoRaceAtomicLoadStorePointer(t *testing.T) {
 	var x int64
+	_ = x
 	var s unsafe.Pointer
 	var y int = 2
 	var p unsafe.Pointer = unsafe.Pointer(&y)
@@ -214,6 +226,7 @@ func TestNoRaceAtomicLoadStorePointer(t *testing.T) {
 
 func TestNoRaceAtomicStoreCASUint64(t *testing.T) {
 	var x int64
+	_ = x
 	var s uint64
 	go func() {
 		x = 2
diff --git a/src/runtime/race/testdata/chan_test.go b/src/runtime/race/testdata/chan_test.go
index 449191639e..7f349c42ed 100644
--- a/src/runtime/race/testdata/chan_test.go
+++ b/src/runtime/race/testdata/chan_test.go
@@ -12,6 +12,7 @@ import (
 
 func TestNoRaceChanSync(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		v = 1
@@ -23,6 +24,7 @@ func TestNoRaceChanSync(t *testing.T) {
 
 func TestNoRaceChanSyncRev(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		c <- 0
@@ -34,6 +36,7 @@ func TestNoRaceChanSyncRev(t *testing.T) {
 
 func TestNoRaceChanAsync(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -45,6 +48,7 @@ func TestNoRaceChanAsync(t *testing.T) {
 
 func TestRaceChanAsyncRev(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		c <- 0
@@ -56,6 +60,7 @@ func TestRaceChanAsyncRev(t *testing.T) {
 
 func TestNoRaceChanAsyncCloseRecv(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -72,6 +77,7 @@ func TestNoRaceChanAsyncCloseRecv(t *testing.T) {
 
 func TestNoRaceChanAsyncCloseRecv2(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -83,6 +89,7 @@ func TestNoRaceChanAsyncCloseRecv2(t *testing.T) {
 
 func TestNoRaceChanAsyncCloseRecv3(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -95,6 +102,7 @@ func TestNoRaceChanAsyncCloseRecv3(t *testing.T) {
 
 func TestNoRaceChanSyncCloseRecv(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		v = 1
@@ -111,6 +119,7 @@ func TestNoRaceChanSyncCloseRecv(t *testing.T) {
 
 func TestNoRaceChanSyncCloseRecv2(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		v = 1
@@ -122,6 +131,7 @@ func TestNoRaceChanSyncCloseRecv2(t *testing.T) {
 
 func TestNoRaceChanSyncCloseRecv3(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		v = 1
@@ -134,6 +144,7 @@ func TestNoRaceChanSyncCloseRecv3(t *testing.T) {
 
 func TestRaceChanSyncCloseSend(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int)
 	go func() {
 		v = 1
@@ -150,6 +161,7 @@ func TestRaceChanSyncCloseSend(t *testing.T) {
 
 func TestRaceChanAsyncCloseSend(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -170,6 +182,7 @@ func TestRaceChanCloseClose(t *testing.T) {
 	compl := make(chan bool, 2)
 	v1 := 0
 	v2 := 0
+	_ = v1 + v2
 	c := make(chan int)
 	go func() {
 		defer func() {
@@ -197,6 +210,7 @@ func TestRaceChanCloseClose(t *testing.T) {
 
 func TestRaceChanSendLen(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	go func() {
 		v = 1
@@ -210,6 +224,7 @@ func TestRaceChanSendLen(t *testing.T) {
 
 func TestRaceChanRecvLen(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	c <- 1
 	go func() {
@@ -226,6 +241,7 @@ func TestRaceChanSendSend(t *testing.T) {
 	compl := make(chan bool, 2)
 	v1 := 0
 	v2 := 0
+	_ = v1 + v2
 	c := make(chan int, 1)
 	go func() {
 		v1 = 1
@@ -264,6 +280,7 @@ func TestNoRaceChanPtr(t *testing.T) {
 func TestRaceChanWrongSend(t *testing.T) {
 	v1 := 0
 	v2 := 0
+	_ = v1 + v2
 	c := make(chan int, 2)
 	go func() {
 		v1 = 1
@@ -284,6 +301,7 @@ func TestRaceChanWrongSend(t *testing.T) {
 func TestRaceChanWrongClose(t *testing.T) {
 	v1 := 0
 	v2 := 0
+	_ = v1 + v2
 	c := make(chan int, 1)
 	done := make(chan bool)
 	go func() {
@@ -561,6 +579,7 @@ func TestRaceChanItselfCap(t *testing.T) {
 
 func TestRaceChanCloseLen(t *testing.T) {
 	v := 0
+	_ = v
 	c := make(chan int, 10)
 	c <- 0
 	go func() {
@@ -587,6 +606,7 @@ func TestNoRaceChanMutex(t *testing.T) {
 	done := make(chan struct{})
 	mtx := make(chan struct{}, 1)
 	data := 0
+	_ = data
 	go func() {
 		mtx <- struct{}{}
 		data = 42
@@ -604,6 +624,7 @@ func TestNoRaceSelectMutex(t *testing.T) {
 	mtx := make(chan struct{}, 1)
 	aux := make(chan bool)
 	data := 0
+	_ = data
 	go func() {
 		select {
 		case mtx <- struct{}{}:
@@ -632,6 +653,7 @@ func TestRaceChanSem(t *testing.T) {
 	done := make(chan struct{})
 	mtx := make(chan bool, 2)
 	data := 0
+	_ = data
 	go func() {
 		mtx <- true
 		data = 42
diff --git a/src/runtime/race/testdata/finalizer_test.go b/src/runtime/race/testdata/finalizer_test.go
index 222cbf67a8..3ac33d2b59 100644
--- a/src/runtime/race/testdata/finalizer_test.go
+++ b/src/runtime/race/testdata/finalizer_test.go
@@ -53,6 +53,7 @@ func TestNoRaceFinGlobal(t *testing.T) {
 func TestRaceFin(t *testing.T) {
 	c := make(chan bool)
 	y := 0
+	_ = y
 	go func() {
 		x := new(string)
 		runtime.SetFinalizer(x, func(x *string) {
diff --git a/src/runtime/race/testdata/map_test.go b/src/runtime/race/testdata/map_test.go
index a8d8148d0e..88e735ecd3 100644
--- a/src/runtime/race/testdata/map_test.go
+++ b/src/runtime/race/testdata/map_test.go
@@ -130,6 +130,7 @@ func TestRaceMapLenDelete(t *testing.T) {
 func TestRaceMapVariable(t *testing.T) {
 	ch := make(chan bool, 1)
 	m := make(map[int]int)
+	_ = m
 	go func() {
 		m = make(map[int]int)
 		ch <- true
@@ -230,6 +231,7 @@ func TestRaceMapAssignMultipleReturn(t *testing.T) {
 	conns[1] = []int{0}
 	ch := make(chan bool, 1)
 	var err error
+	_ = err
 	go func() {
 		conns[1][0], err = connect()
 		ch <- true
diff --git a/src/runtime/race/testdata/mop_test.go b/src/runtime/race/testdata/mop_test.go
index 560a762315..b60cabfe86 100644
--- a/src/runtime/race/testdata/mop_test.go
+++ b/src/runtime/race/testdata/mop_test.go
@@ -60,6 +60,7 @@ func TestRaceIntRWGlobalFuncs(t *testing.T) {
 
 func TestRaceIntRWClosures(t *testing.T) {
 	var x, y int
+	_ = y
 	ch := make(chan int, 2)
 
 	go func() {
@@ -76,6 +77,7 @@ func TestRaceIntRWClosures(t *testing.T) {
 
 func TestNoRaceIntRWClosures(t *testing.T) {
 	var x, y int
+	_ = y
 	ch := make(chan int, 1)
 
 	go func() {
@@ -93,6 +95,7 @@ func TestNoRaceIntRWClosures(t *testing.T) {
 
 func TestRaceInt32RWClosures(t *testing.T) {
 	var x, y int32
+	_ = y
 	ch := make(chan bool, 2)
 
 	go func() {
@@ -168,6 +171,7 @@ func TestRaceCaseCondition2(t *testing.T) {
 
 func TestRaceCaseBody(t *testing.T) {
 	var x, y int
+	_ = y
 	ch := make(chan int, 2)
 
 	go func() {
@@ -189,6 +193,7 @@ func TestRaceCaseBody(t *testing.T) {
 
 func TestNoRaceCaseFallthrough(t *testing.T) {
 	var x, y, z int
+	_ = y
 	ch := make(chan int, 2)
 	z = 1
 
@@ -210,6 +215,7 @@ func TestNoRaceCaseFallthrough(t *testing.T) {
 
 func TestRaceCaseFallthrough(t *testing.T) {
 	var x, y, z int
+	_ = y
 	ch := make(chan int, 2)
 	z = 1
 
@@ -323,6 +329,7 @@ func TestRaceRange(t *testing.T) {
 	const N = 2
 	var a [N]int
 	var x, y int
+	_ = x + y
 	done := make(chan bool, N)
 	for i, v := range a {
 		go func(i int) {
@@ -433,6 +440,7 @@ func TestNoRaceForIncr(t *testing.T) {
 
 func TestRacePlus(t *testing.T) {
 	var x, y, z int
+	_ = y
 	ch := make(chan int, 2)
 
 	go func() {
@@ -449,6 +457,7 @@ func TestRacePlus(t *testing.T) {
 
 func TestRacePlus2(t *testing.T) {
 	var x, y, z int
+	_ = y
 	ch := make(chan int, 2)
 
 	go func() {
@@ -465,6 +474,7 @@ func TestRacePlus2(t *testing.T) {
 
 func TestNoRacePlus(t *testing.T) {
 	var x, y, z, f int
+	_ = x + y + f
 	ch := make(chan int, 2)
 
 	go func() {
@@ -481,6 +491,7 @@ func TestNoRacePlus(t *testing.T) {
 
 func TestRaceComplement(t *testing.T) {
 	var x, y, z int
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -497,6 +508,7 @@ func TestRaceComplement(t *testing.T) {
 
 func TestRaceDiv(t *testing.T) {
 	var x, y, z int
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -513,6 +525,7 @@ func TestRaceDiv(t *testing.T) {
 
 func TestRaceDivConst(t *testing.T) {
 	var x, y, z uint32
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -529,6 +542,7 @@ func TestRaceDivConst(t *testing.T) {
 
 func TestRaceMod(t *testing.T) {
 	var x, y, z int
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -545,6 +559,7 @@ func TestRaceMod(t *testing.T) {
 
 func TestRaceModConst(t *testing.T) {
 	var x, y, z int
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -561,6 +576,7 @@ func TestRaceModConst(t *testing.T) {
 
 func TestRaceRotate(t *testing.T) {
 	var x, y, z uint32
+	_ = x
 	ch := make(chan int, 2)
 
 	go func() {
@@ -932,6 +948,7 @@ func TestRaceFuncVariableRW(t *testing.T) {
 
 func TestRaceFuncVariableWW(t *testing.T) {
 	var f func(x int) int
+	_ = f
 	ch := make(chan bool, 1)
 	go func() {
 		f = func(x int) int {
@@ -948,6 +965,7 @@ func TestRaceFuncVariableWW(t *testing.T) {
 // This one should not belong to mop_test
 func TestRacePanic(t *testing.T) {
 	var x int
+	_ = x
 	var zero int = 0
 	ch := make(chan bool, 2)
 	go func() {
@@ -1284,6 +1302,7 @@ func TestNoRaceFuncUnlock(t *testing.T) {
 	ch := make(chan bool, 1)
 	var mu sync.Mutex
 	x := 0
+	_ = x
 	go func() {
 		mu.Lock()
 		x = 42
@@ -1812,6 +1831,7 @@ func TestNoRaceAsFunc4(t *testing.T) {
 	c := make(chan bool, 1)
 	var mu sync.Mutex
 	x := 0
+	_ = x
 	go func() {
 		x = func() int { // Write of x must be under the mutex.
 			mu.Lock()
@@ -2042,6 +2062,7 @@ func TestNoRaceTinyAlloc(t *testing.T) {
 	const P = 4
 	const N = 1e6
 	var tinySink *byte
+	_ = tinySink
 	done := make(chan bool)
 	for p := 0; p < P; p++ {
 		go func() {
diff --git a/src/runtime/race/testdata/mutex_test.go b/src/runtime/race/testdata/mutex_test.go
index 3cf03ae6b8..cbed2d370c 100644
--- a/src/runtime/race/testdata/mutex_test.go
+++ b/src/runtime/race/testdata/mutex_test.go
@@ -13,6 +13,7 @@ import (
 func TestNoRaceMutex(t *testing.T) {
 	var mu sync.Mutex
 	var x int16 = 0
+	_ = x
 	ch := make(chan bool, 2)
 	go func() {
 		mu.Lock()
@@ -33,6 +34,7 @@ func TestNoRaceMutex(t *testing.T) {
 func TestRaceMutex(t *testing.T) {
 	var mu sync.Mutex
 	var x int16 = 0
+	_ = x
 	ch := make(chan bool, 2)
 	go func() {
 		x = 1
@@ -54,6 +56,7 @@ func TestRaceMutex2(t *testing.T) {
 	var mu1 sync.Mutex
 	var mu2 sync.Mutex
 	var x int8 = 0
+	_ = x
 	ch := make(chan bool, 2)
 	go func() {
 		mu1.Lock()
@@ -74,6 +77,7 @@ func TestRaceMutex2(t *testing.T) {
 func TestNoRaceMutexPureHappensBefore(t *testing.T) {
 	var mu sync.Mutex
 	var x int16 = 0
+	_ = x
 	ch := make(chan bool, 2)
 	go func() {
 		x = 1
@@ -96,6 +100,7 @@ func TestNoRaceMutexSemaphore(t *testing.T) {
 	var mu sync.Mutex
 	ch := make(chan bool, 2)
 	x := 0
+	_ = x
 	mu.Lock()
 	go func() {
 		x = 1
diff --git a/src/runtime/race/testdata/rwmutex_test.go b/src/runtime/race/testdata/rwmutex_test.go
index 7ac829d759..39219e58ae 100644
--- a/src/runtime/race/testdata/rwmutex_test.go
+++ b/src/runtime/race/testdata/rwmutex_test.go
@@ -14,6 +14,7 @@ func TestRaceMutexRWMutex(t *testing.T) {
 	var mu1 sync.Mutex
 	var mu2 sync.RWMutex
 	var x int16 = 0
+	_ = x
 	ch := make(chan bool, 2)
 	go func() {
 		mu1.Lock()
@@ -34,6 +35,7 @@ func TestRaceMutexRWMutex(t *testing.T) {
 func TestNoRaceRWMutex(t *testing.T) {
 	var mu sync.RWMutex
 	var x, y int64 = 0, 1
+	_ = y
 	ch := make(chan bool, 2)
 	go func() {
 		mu.Lock()
diff --git a/src/runtime/race/testdata/select_test.go b/src/runtime/race/testdata/select_test.go
index 9969f47e8e..3827867687 100644
--- a/src/runtime/race/testdata/select_test.go
+++ b/src/runtime/race/testdata/select_test.go
@@ -11,6 +11,7 @@ import (
 
 func TestNoRaceSelect1(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool)
 	c := make(chan bool)
 	c1 := make(chan bool)
@@ -36,6 +37,7 @@ func TestNoRaceSelect1(t *testing.T) {
 
 func TestNoRaceSelect2(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool)
 	c := make(chan bool)
 	c1 := make(chan bool)
@@ -55,6 +57,7 @@ func TestNoRaceSelect2(t *testing.T) {
 
 func TestNoRaceSelect3(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool)
 	c := make(chan bool, 10)
 	c1 := make(chan bool)
@@ -112,6 +115,7 @@ func TestNoRaceSelect4(t *testing.T) {
 func TestNoRaceSelect5(t *testing.T) {
 	test := func(sel, needSched bool) {
 		var x int
+		_ = x
 		ch := make(chan bool)
 		c1 := make(chan bool)
 
@@ -158,6 +162,7 @@ func TestNoRaceSelect5(t *testing.T) {
 
 func TestRaceSelect1(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool, 2)
 	c := make(chan bool)
 	c1 := make(chan bool)
@@ -182,6 +187,7 @@ func TestRaceSelect1(t *testing.T) {
 
 func TestRaceSelect2(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool)
 	c := make(chan bool)
 	c1 := make(chan bool)
@@ -200,6 +206,7 @@ func TestRaceSelect2(t *testing.T) {
 
 func TestRaceSelect3(t *testing.T) {
 	var x int
+	_ = x
 	compl := make(chan bool)
 	c := make(chan bool)
 	c1 := make(chan bool)
diff --git a/src/runtime/race/testdata/sync_test.go b/src/runtime/race/testdata/sync_test.go
index d48680d5e6..2b2d95d76b 100644
--- a/src/runtime/race/testdata/sync_test.go
+++ b/src/runtime/race/testdata/sync_test.go
@@ -12,6 +12,7 @@ import (
 
 func TestNoRaceCond(t *testing.T) {
 	x := 0
+	_ = x
 	condition := 0
 	var mu sync.Mutex
 	cond := sync.NewCond(&mu)
@@ -35,6 +36,7 @@ func TestRaceCond(t *testing.T) {
 	var mu sync.Mutex
 	cond := sync.NewCond(&mu)
 	x := 0
+	_ = x
 	condition := 0
 	go func() {
 		time.Sleep(10 * time.Millisecond) // Enter cond.Wait loop
@@ -67,6 +69,7 @@ func TestRaceAnnounceThreads(t *testing.T) {
 	allDone := make(chan bool, N)
 
 	var x int
+	_ = x
 
 	var f, g, h func()
 	f = func() {
@@ -133,6 +136,7 @@ func TestNoRaceAfterFunc2(t *testing.T) {
 func TestNoRaceAfterFunc3(t *testing.T) {
 	c := make(chan bool, 1)
 	x := 0
+	_ = x
 	time.AfterFunc(1e7, func() {
 		x = 1
 		c <- true
@@ -143,6 +147,7 @@ func TestNoRaceAfterFunc3(t *testing.T) {
 func TestRaceAfterFunc3(t *testing.T) {
 	c := make(chan bool, 2)
 	x := 0
+	_ = x
 	time.AfterFunc(1e7, func() {
 		x = 1
 		c <- true
@@ -161,6 +166,7 @@ func TestRaceAfterFunc3(t *testing.T) {
 // comprehensible.
 func TestRaceGoroutineCreationStack(t *testing.T) {
 	var x int
+	_ = x
 	var ch = make(chan bool, 1)
 
 	f1 := func() {
diff --git a/src/runtime/race/testdata/waitgroup_test.go b/src/runtime/race/testdata/waitgroup_test.go
index ff152b0abe..169337315b 100644
--- a/src/runtime/race/testdata/waitgroup_test.go
+++ b/src/runtime/race/testdata/waitgroup_test.go
@@ -13,6 +13,7 @@ import (
 
 func TestNoRaceWaitGroup(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	n := 1
 	for i := 0; i < n; i++ {
@@ -28,6 +29,7 @@ func TestNoRaceWaitGroup(t *testing.T) {
 
 func TestRaceWaitGroup(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	n := 2
 	for i := 0; i < n; i++ {
@@ -43,6 +45,7 @@ func TestRaceWaitGroup(t *testing.T) {
 
 func TestNoRaceWaitGroup2(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	wg.Add(1)
 	go func() {
@@ -56,6 +59,7 @@ func TestNoRaceWaitGroup2(t *testing.T) {
 // incrementing counter in Add and locking wg's mutex
 func TestRaceWaitGroupAsMutex(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	c := make(chan bool, 2)
 	go func() {
@@ -82,6 +86,7 @@ func TestRaceWaitGroupAsMutex(t *testing.T) {
 func TestRaceWaitGroupWrongWait(t *testing.T) {
 	c := make(chan bool, 2)
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	go func() {
 		wg.Add(1)
@@ -187,6 +192,7 @@ func TestNoRaceWaitGroupMultipleWait3(t *testing.T) {
 // Correct usage but still a race
 func TestRaceWaitGroup2(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	wg.Add(2)
 	go func() {
@@ -202,6 +208,7 @@ func TestRaceWaitGroup2(t *testing.T) {
 
 func TestNoRaceWaitGroupPanicRecover(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	defer func() {
 		err := recover()
@@ -219,6 +226,7 @@ func TestNoRaceWaitGroupPanicRecover(t *testing.T) {
 // Is it possible to get a race by synchronization via panic?
 func TestNoRaceWaitGroupPanicRecover2(t *testing.T) {
 	var x int
+	_ = x
 	var wg sync.WaitGroup
 	ch := make(chan bool, 1)
 	var f func() = func() {