1 files changed, 550 insertions, 0 deletions
diff --git a/src/runtime/coverage/emitdata_test.go b/src/runtime/coverage/emitdata_test.go
new file mode 100644
index 0000000..3558dd2
--- /dev/null
+++ b/src/runtime/coverage/emitdata_test.go
@@ -0,0 +1,550 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package coverage
+
+import (
+	"fmt"
+	"internal/coverage"
+	"internal/goexperiment"
+	"internal/platform"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// Set to true for debugging (linux only).
+const fixedTestDir = false
+
+func TestCoverageApis(t *testing.T) {
+	if testing.Short() {
+		t.Skipf("skipping test: too long for short mode")
+	}
+	if !goexperiment.CoverageRedesign {
+		t.Skipf("skipping new coverage tests (experiment not enabled)")
+	}
+	testenv.MustHaveGoBuild(t)
+	dir := t.TempDir()
+	if fixedTestDir {
+		dir = "/tmp/qqqzzz"
+		os.RemoveAll(dir)
+		mkdir(t, dir)
+	}
+
+	// Build harness. We need two copies of the harness, one built
+	// with -covermode=atomic and one built non-atomic.
+	bdir1 := mkdir(t, filepath.Join(dir, "build1"))
+	hargs1 := []string{"-covermode=atomic", "-coverpkg=all"}
+	atomicHarnessPath := buildHarness(t, bdir1, hargs1)
+	nonAtomicMode := testing.CoverMode()
+	if testing.CoverMode() == "atomic" {
+		nonAtomicMode = "set"
+	}
+	bdir2 := mkdir(t, filepath.Join(dir, "build2"))
+	hargs2 := []string{"-coverpkg=all", "-covermode=" + nonAtomicMode}
+	nonAtomicHarnessPath := buildHarness(t, bdir2, hargs2)
+
+	t.Logf("atomic harness path is %s", atomicHarnessPath)
+	t.Logf("non-atomic harness path is %s", nonAtomicHarnessPath)
+
+	// Sub-tests for each API we want to inspect, plus
+	// extras for error testing.
+	t.Run("emitToDir", func(t *testing.T) {
+		t.Parallel()
+		testEmitToDir(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitToWriter", func(t *testing.T) {
+		t.Parallel()
+		testEmitToWriter(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitToNonexistentDir", func(t *testing.T) {
+		t.Parallel()
+		testEmitToNonexistentDir(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitToNilWriter", func(t *testing.T) {
+		t.Parallel()
+		testEmitToNilWriter(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitToFailingWriter", func(t *testing.T) {
+		t.Parallel()
+		testEmitToFailingWriter(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitWithCounterClear", func(t *testing.T) {
+		t.Parallel()
+		testEmitWithCounterClear(t, atomicHarnessPath, dir)
+	})
+	t.Run("emitToDirNonAtomic", func(t *testing.T) {
+		t.Parallel()
+		testEmitToDirNonAtomic(t, nonAtomicHarnessPath, nonAtomicMode, dir)
+	})
+	t.Run("emitToWriterNonAtomic", func(t *testing.T) {
+		t.Parallel()
+		testEmitToWriterNonAtomic(t, nonAtomicHarnessPath, nonAtomicMode, dir)
+	})
+	t.Run("emitWithCounterClearNonAtomic", func(t *testing.T) {
+		t.Parallel()
+		testEmitWithCounterClearNonAtomic(t, nonAtomicHarnessPath, nonAtomicMode, dir)
+	})
+}
+
+// upmergeCoverData helps improve coverage data for this package
+// itself. If this test itself is being invoked with "-cover", then
+// what we'd like is for package coverage data (that is, coverage for
+// routines in "runtime/coverage") to be incorporated into the test
+// run from the "harness.exe" runs we've just done. We can accomplish
+// this by doing a merge from the harness gocoverdir's to the test
+// gocoverdir.
+func upmergeCoverData(t *testing.T, gocoverdir string, mode string) {
+	if testing.CoverMode() != mode {
+		return
+	}
+	testGoCoverDir := os.Getenv("GOCOVERDIR")
+	if testGoCoverDir == "" {
+		return
+	}
+	args := []string{"tool", "covdata", "merge", "-pkg=runtime/coverage",
+		"-o", testGoCoverDir, "-i", gocoverdir}
+	t.Logf("up-merge of covdata from %s to %s", gocoverdir, testGoCoverDir)
+	t.Logf("executing: go %+v", args)
+	cmd := exec.Command(testenv.GoToolPath(t), args...)
+	if b, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("covdata merge failed (%v): %s", err, b)
+	}
+}
+
+// buildHarness builds the helper program "harness.exe".
+func buildHarness(t *testing.T, dir string, opts []string) string {
+	harnessPath := filepath.Join(dir, "harness.exe")
+	harnessSrc := filepath.Join("testdata", "harness.go")
+	args := []string{"build", "-o", harnessPath}
+	args = append(args, opts...)
+	args = append(args, harnessSrc)
+	//t.Logf("harness build: go %+v\n", args)
+	cmd := exec.Command(testenv.GoToolPath(t), args...)
+	if b, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("build failed (%v): %s", err, b)
+	}
+	return harnessPath
+}
+
+func mkdir(t *testing.T, d string) string {
+	t.Helper()
+	if err := os.Mkdir(d, 0777); err != nil {
+		t.Fatalf("mkdir failed: %v", err)
+	}
+	return d
+}
+
+// updateGoCoverDir updates the specified environment 'env' to set
+// GOCOVERDIR to 'gcd' (if setGoCoverDir is TRUE) or removes
+// GOCOVERDIR from the environment (if setGoCoverDir is false).
+func updateGoCoverDir(env []string, gcd string, setGoCoverDir bool) []string {
+	rv := []string{}
+	found := false
+	for _, v := range env {
+		if strings.HasPrefix(v, "GOCOVERDIR=") {
+			if !setGoCoverDir {
+				continue
+			}
+			v = "GOCOVERDIR=" + gcd
+			found = true
+		}
+		rv = append(rv, v)
+	}
+	if !found && setGoCoverDir {
+		rv = append(rv, "GOCOVERDIR="+gcd)
+	}
+	return rv
+}
+
+func runHarness(t *testing.T, harnessPath string, tp string, setGoCoverDir bool, rdir, edir string) (string, error) {
+	t.Logf("running: %s -tp %s -o %s with rdir=%s and GOCOVERDIR=%v", harnessPath, tp, edir, rdir, setGoCoverDir)
+	cmd := exec.Command(harnessPath, "-tp", tp, "-o", edir)
+	cmd.Dir = rdir
+	cmd.Env = updateGoCoverDir(os.Environ(), rdir, setGoCoverDir)
+	b, err := cmd.CombinedOutput()
+	//t.Logf("harness run output: %s\n", string(b))
+	return string(b), err
+}
+
+func testForSpecificFunctions(t *testing.T, dir string, want []string, avoid []string) string {
+	args := []string{"tool", "covdata", "debugdump",
+		"-live", "-pkg=command-line-arguments", "-i=" + dir}
+	t.Logf("running: go %v\n", args)
+	cmd := exec.Command(testenv.GoToolPath(t), args...)
+	b, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("'go tool covdata failed (%v): %s", err, b)
+	}
+	output := string(b)
+	rval := ""
+	for _, f := range want {
+		wf := "Func: " + f + "\n"
+		if strings.Contains(output, wf) {
+			continue
+		}
+		rval += fmt.Sprintf("error: output should contain %q but does not\n", wf)
+	}
+	for _, f := range avoid {
+		wf := "Func: " + f + "\n"
+		if strings.Contains(output, wf) {
+			rval += fmt.Sprintf("error: output should not contain %q but does\n", wf)
+		}
+	}
+	if rval != "" {
+		t.Logf("=-= begin output:\n" + output + "\n=-= end output\n")
+	}
+	return rval
+}
+
+func withAndWithoutRunner(f func(setit bool, tag string)) {
+	// Run 'f' with and without GOCOVERDIR set.
+	for i := 0; i < 2; i++ {
+		tag := "x"
+		setGoCoverDir := true
+		if i == 0 {
+			setGoCoverDir = false
+			tag = "y"
+		}
+		f(setGoCoverDir, tag)
+	}
+}
+
+func mktestdirs(t *testing.T, tag, tp, dir string) (string, string) {
+	t.Helper()
+	rdir := mkdir(t, filepath.Join(dir, tp+"-rdir-"+tag))
+	edir := mkdir(t, filepath.Join(dir, tp+"-edir-"+tag))
+	return rdir, edir
+}
+
+func testEmitToDir(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitToDir"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp,
+			setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp emitDir': %v", err)
+		}
+
+		// Just check to make sure meta-data file and counter data file were
+		// written. Another alternative would be to run "go tool covdata"
+		// or equivalent, but for now, this is what we've got.
+		dents, err := os.ReadDir(edir)
+		if err != nil {
+			t.Fatalf("os.ReadDir(%s) failed: %v", edir, err)
+		}
+		mfc := 0
+		cdc := 0
+		for _, e := range dents {
+			if e.IsDir() {
+				continue
+			}
+			if strings.HasPrefix(e.Name(), coverage.MetaFilePref) {
+				mfc++
+			} else if strings.HasPrefix(e.Name(), coverage.CounterFilePref) {
+				cdc++
+			}
+		}
+		wantmf := 1
+		wantcf := 1
+		if mfc != wantmf {
+			t.Errorf("EmitToDir: want %d meta-data files, got %d\n", wantmf, mfc)
+		}
+		if cdc != wantcf {
+			t.Errorf("EmitToDir: want %d counter-data files, got %d\n", wantcf, cdc)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToWriter(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitToWriter"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp, setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		want := []string{"main", tp}
+		avoid := []string{"final"}
+		if msg := testForSpecificFunctions(t, edir, want, avoid); msg != "" {
+			t.Errorf("coverage data from %q output match failed: %s", tp, msg)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToNonexistentDir(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitToNonexistentDir"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp, setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToUnwritableDir(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+
+		tp := "emitToUnwritableDir"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+
+		// Make edir unwritable.
+		if err := os.Chmod(edir, 0555); err != nil {
+			t.Fatalf("chmod failed: %v", err)
+		}
+		defer os.Chmod(edir, 0777)
+
+		output, err := runHarness(t, harnessPath, tp, setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToNilWriter(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitToNilWriter"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp, setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToFailingWriter(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitToFailingWriter"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp, setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitWithCounterClear(t *testing.T, harnessPath string, dir string) {
+	withAndWithoutRunner(func(setGoCoverDir bool, tag string) {
+		tp := "emitWithCounterClear"
+		rdir, edir := mktestdirs(t, tag, tp, dir)
+		output, err := runHarness(t, harnessPath, tp,
+			setGoCoverDir, rdir, edir)
+		if err != nil {
+			t.Logf("%s", output)
+			t.Fatalf("running 'harness -tp %s': %v", tp, err)
+		}
+		want := []string{tp, "postClear"}
+		avoid := []string{"preClear", "main", "final"}
+		if msg := testForSpecificFunctions(t, edir, want, avoid); msg != "" {
+			t.Logf("%s", output)
+			t.Errorf("coverage data from %q output match failed: %s", tp, msg)
+		}
+		upmergeCoverData(t, edir, "atomic")
+		upmergeCoverData(t, rdir, "atomic")
+	})
+}
+
+func testEmitToDirNonAtomic(t *testing.T, harnessPath string, naMode string, dir string) {
+	tp := "emitToDir"
+	tag := "nonatomdir"
+	rdir, edir := mktestdirs(t, tag, tp, dir)
+	output, err := runHarness(t, harnessPath, tp,
+		true, rdir, edir)
+
+	// We expect an error here.
+	if err == nil {
+		t.Logf("%s", output)
+		t.Fatalf("running 'harness -tp %s': did not get expected error", tp)
+	}
+
+	got := strings.TrimSpace(string(output))
+	want := "WriteCountersDir invoked for program built"
+	if !strings.Contains(got, want) {
+		t.Errorf("running 'harness -tp %s': got:\n%s\nwant: %s",
+			tp, got, want)
+	}
+	upmergeCoverData(t, edir, naMode)
+	upmergeCoverData(t, rdir, naMode)
+}
+
+func testEmitToWriterNonAtomic(t *testing.T, harnessPath string, naMode string, dir string) {
+	tp := "emitToWriter"
+	tag := "nonatomw"
+	rdir, edir := mktestdirs(t, tag, tp, dir)
+	output, err := runHarness(t, harnessPath, tp,
+		true, rdir, edir)
+
+	// We expect an error here.
+	if err == nil {
+		t.Logf("%s", output)
+		t.Fatalf("running 'harness -tp %s': did not get expected error", tp)
+	}
+
+	got := strings.TrimSpace(string(output))
+	want := "WriteCounters invoked for program built"
+	if !strings.Contains(got, want) {
+		t.Errorf("running 'harness -tp %s': got:\n%s\nwant: %s",
+			tp, got, want)
+	}
+
+	upmergeCoverData(t, edir, naMode)
+	upmergeCoverData(t, rdir, naMode)
+}
+
+func testEmitWithCounterClearNonAtomic(t *testing.T, harnessPath string, naMode string, dir string) {
+	tp := "emitWithCounterClear"
+	tag := "cclear"
+	rdir, edir := mktestdirs(t, tag, tp, dir)
+	output, err := runHarness(t, harnessPath, tp,
+		true, rdir, edir)
+
+	// We expect an error here.
+	if err == nil {
+		t.Logf("%s", output)
+		t.Fatalf("running 'harness -tp %s' nonatomic: did not get expected error", tp)
+	}
+
+	got := strings.TrimSpace(string(output))
+	want := "ClearCounters invoked for program built"
+	if !strings.Contains(got, want) {
+		t.Errorf("running 'harness -tp %s': got:\n%s\nwant: %s",
+			tp, got, want)
+	}
+
+	upmergeCoverData(t, edir, naMode)
+	upmergeCoverData(t, rdir, naMode)
+}
+
+func TestApisOnNocoverBinary(t *testing.T) {
+	if testing.Short() {
+		t.Skipf("skipping test: too long for short mode")
+	}
+	testenv.MustHaveGoBuild(t)
+	dir := t.TempDir()
+
+	// Build harness with no -cover.
+	bdir := mkdir(t, filepath.Join(dir, "nocover"))
+	edir := mkdir(t, filepath.Join(dir, "emitDirNo"))
+	harnessPath := buildHarness(t, bdir, nil)
+	output, err := runHarness(t, harnessPath, "emitToDir", false, edir, edir)
+	if err == nil {
+		t.Fatalf("expected error on TestApisOnNocoverBinary harness run")
+	}
+	const want = "not built with -cover"
+	if !strings.Contains(output, want) {
+		t.Errorf("error output does not contain %q: %s", want, output)
+	}
+}
+
+func TestIssue56006EmitDataRaceCoverRunningGoroutine(t *testing.T) {
+	if testing.Short() {
+		t.Skipf("skipping test: too long for short mode")
+	}
+	if !goexperiment.CoverageRedesign {
+		t.Skipf("skipping new coverage tests (experiment not enabled)")
+	}
+
+	// This test requires "go test -race -cover", meaning that we need
+	// go build, go run, and "-race" support.
+	testenv.MustHaveGoRun(t)
+	if !platform.RaceDetectorSupported(runtime.GOOS, runtime.GOARCH) ||
+		!testenv.HasCGO() {
+		t.Skip("skipped due to lack of race detector support / CGO")
+	}
+
+	// This will run a program with -cover and -race where we have a
+	// goroutine still running (and updating counters) at the point where
+	// the test runtime is trying to write out counter data.
+	cmd := exec.Command(testenv.GoToolPath(t), "test", "-cover", "-race")
+	cmd.Dir = filepath.Join("testdata", "issue56006")
+	b, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("go test -cover -race failed: %v", err)
+	}
+
+	// Don't want to see any data races in output.
+	avoid := []string{"DATA RACE"}
+	for _, no := range avoid {
+		if strings.Contains(string(b), no) {
+			t.Logf("%s\n", string(b))
+			t.Fatalf("found %s in test output, not permitted", no)
+		}
+	}
+}
+
+func TestIssue59563TruncatedCoverPkgAll(t *testing.T) {
+	if testing.Short() {
+		t.Skipf("skipping test: too long for short mode")
+	}
+	testenv.MustHaveGoRun(t)
+
+	tmpdir := t.TempDir()
+	ppath := filepath.Join(tmpdir, "foo.cov")
+
+	cmd := exec.Command(testenv.GoToolPath(t), "test", "-coverpkg=all", "-coverprofile="+ppath)
+	cmd.Dir = filepath.Join("testdata", "issue59563")
+	b, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("go test -cover failed: %v", err)
+	}
+
+	cmd = exec.Command(testenv.GoToolPath(t), "tool", "cover", "-func="+ppath)
+	b, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("go tool cover -func failed: %v", err)
+	}
+
+	lines := strings.Split(string(b), "\n")
+	nfound := 0
+	bad := false
+	for _, line := range lines {
+		f := strings.Fields(line)
+		if len(f) == 0 {
+			continue
+		}
+		// We're only interested in the specific function "large" for
+		// the testcase being built. See the #59563 for details on why
+		// size matters.
+		if !(strings.HasPrefix(f[0], "runtime/coverage/testdata/issue59563/repro.go") && strings.Contains(line, "large")) {
+			continue
+		}
+		nfound++
+		want := "100.0%"
+		if f[len(f)-1] != want {
+			t.Errorf("wanted %s got: %q\n", want, line)
+			bad = true
+		}
+	}
+	if nfound != 1 {
+		t.Errorf("wanted 1 found, got %d\n", nfound)
+		bad = true
+	}
+	if bad {
+		t.Logf("func output:\n%s\n", string(b))
+	}
+}