testing: mark tests and benchmarks failed if a race occurs during execution

Before:

$ go test -race -v -run TestRace
=== RUN   TestRace
==================
WARNING: DATA RACE
Write at 0x00c420076420 by goroutine 7:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace.func1()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:10 +0x3b

Previous write at 0x00c420076420 by goroutine 6:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:13 +0xcc
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104

Goroutine 7 (running) created at:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:12 +0xbb
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104

Goroutine 6 (running) created at:
  testing.(*T).Run()
      /Users/rsc/go/src/testing/testing.go:693 +0x536
  testing.runTests.func1()
      /Users/rsc/go/src/testing/testing.go:877 +0xaa
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104
  testing.runTests()
      /Users/rsc/go/src/testing/testing.go:883 +0x4ac
  testing.(*M).Run()
      /Users/rsc/go/src/testing/testing.go:818 +0x1c3
  main.main()
      _/Users/rsc/go/src/cmd/go/testdata/src/testrace/_test/_testmain.go:42 +0x20f
==================
--- PASS: TestRace (0.00s)
PASS
Found 1 data race(s)
FAIL	_/Users/rsc/go/src/cmd/go/testdata/src/testrace	1.026s
$

After:

$ go test -race -v -run TestRace
=== RUN   TestRace
==================
WARNING: DATA RACE
Write at 0x00c420076420 by goroutine 7:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace.func1()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:10 +0x3b

Previous write at 0x00c420076420 by goroutine 6:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:13 +0xcc
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104

Goroutine 7 (running) created at:
  _/Users/rsc/go/src/cmd/go/testdata/src/testrace.TestRace()
      /Users/rsc/go/src/cmd/go/testdata/src/testrace/race_test.go:12 +0xbb
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104

Goroutine 6 (running) created at:
  testing.(*T).Run()
      /Users/rsc/go/src/testing/testing.go:693 +0x536
  testing.runTests.func1()
      /Users/rsc/go/src/testing/testing.go:877 +0xaa
  testing.tRunner()
      /Users/rsc/go/src/testing/testing.go:656 +0x104
  testing.runTests()
      /Users/rsc/go/src/testing/testing.go:883 +0x4ac
  testing.(*M).Run()
      /Users/rsc/go/src/testing/testing.go:818 +0x1c3
  main.main()
      _/Users/rsc/go/src/cmd/go/testdata/src/testrace/_test/_testmain.go:42 +0x20f
==================
--- FAIL: TestRace (0.00s)
	testing.go:609: race detected during execution of test
FAIL
FAIL	_/Users/rsc/go/src/cmd/go/testdata/src/testrace	0.022s
$

Fixes #15972.

Change-Id: Idb15b8ab81d65637bb535c7e275595ca4a6e450e
Reviewed-on: https://go-review.googlesource.com/32615
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/go/go_test.go

@@ -2828,6 +2828,26 @@ func TestGoTestRaceInstallCgo(t *testing.T) {
 	}
 }
 
+func TestGoTestRaceFailures(t *testing.T) {
+	if !canRace {
+		t.Skip("skipping because race detector not supported")
+	}
+
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
+
+	tg.run("test", "testrace")
+
+	tg.runFail("test", "-race", "testrace")
+	tg.grepStdout("FAIL: TestRace", "TestRace did not fail")
+	tg.grepBothNot("PASS", "something passed")
+
+	tg.runFail("test", "-race", "testrace", "-run", "XXX", "-bench", ".")
+	tg.grepStdout("FAIL: BenchmarkRace", "BenchmarkRace did not fail")
+	tg.grepBothNot("PASS", "something passed")
+}
+
 func TestGoTestImportErrorStack(t *testing.T) {
 	const out = `package testdep/p1 (test)
 	imports testdep/p2

src/cmd/go/testdata/src/testrace/race_test.go

@@ -0,0 +1,29 @@
+package testrace
+
+import "testing"
+
+func TestRace(t *testing.T) {
+	for i := 0; i < 10; i++ {
+		c := make(chan int)
+		x := 1
+		go func() {
+			x = 2
+			c <- 1
+		}()
+		x = 3
+		<-c
+	}
+}
+
+func BenchmarkRace(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		c := make(chan int)
+		x := 1
+		go func() {
+			x = 2
+			c <- 1
+		}()
+		x = 3
+		<-c
+	}
+}

src/go/build/deps_test.go

@@ -178,7 +178,7 @@ var pkgDeps = map[string][]string{
 	"runtime/trace":                {"L0"},
 	"text/tabwriter":               {"L2"},
 
-	"testing":          {"L2", "flag", "fmt", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
+	"testing":          {"L2", "flag", "fmt", "internal/race", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
 	"testing/iotest":   {"L2", "log"},
 	"testing/quick":    {"L2", "flag", "fmt", "reflect"},
 	"internal/testenv": {"L2", "OS", "flag", "testing", "syscall"},

src/internal/race/norace.go

@@ -38,3 +38,5 @@ func ReadRange(addr unsafe.Pointer, len int) {
 
 func WriteRange(addr unsafe.Pointer, len int) {
 }
+
+func Errors() int { return 0 }

src/internal/race/race.go

@@ -48,3 +48,7 @@ func ReadRange(addr unsafe.Pointer, len int) {
 func WriteRange(addr unsafe.Pointer, len int) {
 	runtime.RaceWriteRange(addr, len)
 }
+
+func Errors() int {
+	return runtime.RaceErrors()
+}

src/runtime/race.go

@@ -20,6 +20,12 @@ func RaceWriteRange(addr unsafe.Pointer, len int)
 func RaceSemacquire(s *uint32)
 func RaceSemrelease(s *uint32)
 
+func RaceErrors() int {
+	var n uint64
+	racecall(&__tsan_report_count, uintptr(unsafe.Pointer(&n)), 0, 0, 0)
+	return int(n)
+}
+
 // private interface for the runtime
 const raceenabled = true
 

src/runtime/race/output_test.go

@@ -184,8 +184,8 @@ func TestFail(t *testing.T) {
 }
 `, `
 ==================
-PASS
+--- FAIL: TestFail \(0.00s\)
-Found 1 data race\(s\)
+.*testing.go:.*: race detected during execution of test
 FAIL`},
 
 	{"slicebytetostring_pc", "run", "", "atexit_sleep_ms=0", `

src/runtime/race/race_test.go

@@ -173,9 +173,11 @@ func runTests(t *testing.T) ([]byte, error) {
 	// (that's what is done for C++ ThreadSanitizer tests). This is issue #14119.
 	cmd.Env = append(cmd.Env,
 		"GOMAXPROCS=1",
-		"GORACE=suppress_equal_stacks=0 suppress_equal_addresses=0 exitcode=0",
+		"GORACE=suppress_equal_stacks=0 suppress_equal_addresses=0",
 	)
-	return cmd.CombinedOutput()
+	// There are races: we expect tests to fail and the exit code to be non-zero.
+	out, _ := cmd.CombinedOutput()
+	return out, nil
 }
 
 func TestIssue8102(t *testing.T) {

src/testing/benchmark.go

@@ -7,6 +7,7 @@ package testing
 import (
 	"flag"
 	"fmt"
+	"internal/race"
 	"os"
 	"runtime"
 	"sync"
@@ -131,6 +132,7 @@ func (b *B) runN(n int) {
 	// Try to get a comparable environment for each run
 	// by clearing garbage from previous runs.
 	runtime.GC()
+	b.raceErrors = -race.Errors()
 	b.N = n
 	b.parallelism = 1
 	b.ResetTimer()
@@ -139,6 +141,10 @@ func (b *B) runN(n int) {
 	b.StopTimer()
 	b.previousN = n
 	b.previousDuration = b.duration
+	b.raceErrors += race.Errors()
+	if b.raceErrors > 0 {
+		b.Errorf("race detected during execution of benchmark")
+	}
 }
 
 func min(x, y int) int {

src/testing/testing.go

@@ -207,6 +207,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"internal/race"
 	"io"
 	"os"
 	"runtime"
@@ -257,16 +258,17 @@ var (
 // common holds the elements common between T and B and
 // captures common methods such as Errorf.
 type common struct {
-	mu       sync.RWMutex // guards output, failed, and done.
+	mu         sync.RWMutex // guards output, failed, and done.
-	output   []byte       // Output generated by test or benchmark.
+	output     []byte       // Output generated by test or benchmark.
-	w        io.Writer    // For flushToParent.
+	w          io.Writer    // For flushToParent.
-	chatty   bool         // A copy of the chatty flag.
+	chatty     bool         // A copy of the chatty flag.
-	ran      bool         // Test or benchmark (or one of its subtests) was executed.
+	ran        bool         // Test or benchmark (or one of its subtests) was executed.
-	failed   bool         // Test or benchmark has failed.
+	failed     bool         // Test or benchmark has failed.
-	skipped  bool         // Test of benchmark has been skipped.
+	skipped    bool         // Test of benchmark has been skipped.
-	finished bool         // Test function has completed.
+	finished   bool         // Test function has completed.
-	done     bool         // Test is finished and all subtests have completed.
+	done       bool         // Test is finished and all subtests have completed.
-	hasSub   bool
+	hasSub     bool
+	raceErrors int // number of races detected during test
 
 	parent   *common
 	level    int       // Nesting depth of test or benchmark.
@@ -580,11 +582,13 @@ func (t *T) Parallel() {
 
 	// Add to the list of tests to be released by the parent.
 	t.parent.sub = append(t.parent.sub, t)
+	t.raceErrors += race.Errors()
 
 	t.signal <- true   // Release calling test.
 	<-t.parent.barrier // Wait for the parent test to complete.
 	t.context.waitParallel()
 	t.start = time.Now()
+	t.raceErrors += -race.Errors()
 }
 
 // An internal type but exported because it is cross-package; part of the implementation
@@ -600,6 +604,11 @@ func tRunner(t *T, fn func(t *T)) {
 	// a call to runtime.Goexit, record the duration and send
 	// a signal saying that the test is done.
 	defer func() {
+		t.raceErrors += race.Errors()
+		if t.raceErrors > 0 {
+			t.Errorf("race detected during execution of test")
+		}
+
 		t.duration += time.Now().Sub(t.start)
 		// If the test panicked, print any test output before dying.
 		err := recover()
@@ -643,6 +652,7 @@ func tRunner(t *T, fn func(t *T)) {
 	}()
 
 	t.start = time.Now()
+	t.raceErrors = -race.Errors()
 	fn(t)
 	t.finished = true
 }
@@ -810,7 +820,7 @@ func (m *M) Run() int {
 	if !testRan && !exampleRan && *matchBenchmarks == "" {
 		fmt.Fprintln(os.Stderr, "testing: warning: no tests to run")
 	}
-	if !testOk || !exampleOk || !runBenchmarks(m.deps.MatchString, m.benchmarks) {
+	if !testOk || !exampleOk || !runBenchmarks(m.deps.MatchString, m.benchmarks) || race.Errors() > 0 {
 		fmt.Println("FAIL")
 		m.after()
 		return 1