[race] go build -o examplewithrace.exe -race -cover example/main &
wait

# First execute without GOCOVERDIR set...
env GOCOVERDIR=
exec ./example.exe normal
stderr '^warning: GOCOVERDIR not set, no coverage data emitted'

# ... then with GOCOVERDIR set.
env GOCOVERDIR=data/normal
exec ./example.exe normal
! stderr '^warning: GOCOVERDIR not set, no coverage data emitted'
go tool covdata percent -i=data/normal

# Build a stdlib command with coverage.
go build -o $WORK/nm.exe -cover cmd/nm 

# Save off old GOCOVERDIR setting
env SAVEGOCOVERDIR=$GOCOVERDIR

# Collect a coverage profile from running 'cmd/nm' on the object.
mkdir $WORK/covdata
env GOCOVERDIR=$WORK/covdata
exec $WORK/nm.exe tiny.o

# Restore previous GOCOVERDIR setting
env GOCOVERDIR=$SAVEGOCOVERDIR

# Check to make sure we instrumented just the main package, not

}

func coverTearDown(coverprofile string, gocoverdir string) (string, error) {
	var err error
	if gocoverdir == "" {
		gocoverdir, err = os.MkdirTemp("", "gocoverdir")
		if err != nil {
			return "error setting GOCOVERDIR: bad os.MkdirTemp return", err
		}
		defer os.RemoveAll(gocoverdir)
	}
	CoverMarkProfileEmittedFunc(true)
	cmode := CoverMode

# Build this program with -cover and run to collect a profile.

go build -cover -o $WORK/prog.exe .

# Save off old GOCOVERDIR setting
env SAVEGOCOVERDIR=$GOCOVERDIR

mkdir $WORK/covdata
env GOCOVERDIR=$WORK/covdata
exec $WORK/prog.exe

# Restore previous GOCOVERDIR setting
env GOCOVERDIR=$SAVEGOCOVERDIR

# Report percent lines covered.
go tool covdata percent -i=$WORK/covdata
stdout '\s*mainwithtest\s+coverage:'

# Build for coverage.
go build -mod=mod -o $WORK/modex.exe -cover mod.example/main

# Save off old GOCOVERDIR setting
env SAVEGOCOVERDIR=$GOCOVERDIR

# Execute.
mkdir $WORK/covdata
env GOCOVERDIR=$WORK/covdata
exec $WORK/modex.exe

# Restore previous GOCOVERDIR setting
env GOCOVERDIR=$SAVEGOCOVERDIR

# Examine the result.
go tool covdata percent -i=$WORK/covdata
stdout 'coverage: 100.0% of statements'

	mode        string
	tearDown    func(coverprofile string, gocoverdir string) (string, error)
	snapshotcov func() float64
}

// registerCover2 is invoked during "go test -cover" runs.
// It is used to record a 'tear down' function
// (to be called when the test is complete) and the coverage mode.
func registerCover2(mode string, tearDown func(coverprofile string, gocoverdir string) (string, error), snapcov func() float64) {
	if mode == "" {

// 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}

	}
	if len(ml) == 0 {
		fmt.Fprintf(os.Stderr, "program not built with -cover\n")
		return
	}

	goCoverDir = os.Getenv("GOCOVERDIR")
	if goCoverDir == "" {
		fmt.Fprintf(os.Stderr, "warning: GOCOVERDIR not set, no coverage data emitted\n")
		return
	}

	if err := emitMetaDataToDirectory(goCoverDir, ml); err != nil {
		fmt.Fprintf(os.Stderr, "error: coverage meta-data emit failed: %v\n", err)

		var name string
		var found bool
		if name, found = strings.CutPrefix(f.Name, "test."); !found {
			return
		}

		switch name {
		case "testlogfile", "paniconexit0", "fuzzcachedir", "fuzzworker", "gocoverdir":
			// These flags are only for use by cmd/go.
		default:
			names = append(names, name)
		}
	})

	return names

	"internal/goexperiment"
	"internal/testenv"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	_ "unsafe"
)

func testGoCoverDir(t *testing.T) string {
	if f := flag.Lookup("test.gocoverdir"); f != nil {
		if dir := f.Value.String(); dir != "" {
			return dir
		}
	}
	return t.TempDir()
}

// TestTestSupport does a basic verification of the functionality in