if _, ok := nodes[sym]; !ok {
			// We already deleted this node.
			return false, 0
		}
		delete(nodes, sym)

		if origin == sym {
			// We found an unrooted cycle. We already
			// deleted all children of this node. Walk
			// back up, tracking the lowest numbered
			// symbol in this cycle.
			return true, sym
		}

		// Delete children of this node.
		for _, out := range sc.graph[sym] {

			file{"file.txt", 9, 0600, false},
			false,
		},
		{
			"file_cant_exist",
			`{"Replace": {"deleted": "dummy.txt"}}
-- deleted/file.txt --
-- dummy.txt --
`,
			"deleted/file.txt",
			file{},
			true,
		},
		{
			"deleted",
			`{"Replace": {"deleted": ""}}
-- deleted --
`,
			"deleted",
			file{},
			true,
		},
		{
			"dir_on_disk",
			`{}
-- dir/foo.txt --
`,

// then verifies that the statement-marked lines in that file are the same as those in wantStmts
// These files must all be short because this is super-fragile.
// "go build" is run in a temporary directory that is normally deleted, unless -test.v
func testDebugLines(t *testing.T, gcflags, file, function string, wantStmts []int, ignoreRepeats bool) {
	dumpBytes := compileAndDump(t, file, function, gcflags)

	}
	if df != 0 {
		f = f / df
	}
	if dc != 0 {
		c = c / dc
	}

	// Tags are not scaled with the selected output unit because tags are often
	// much smaller than other values which appear, so the range of tag sizes
	// sometimes would appear to be "0..0" when scaled to the selected output unit.
	return measurement.Label(min.Value, min.Unit) + ".." + measurement.Label(max.Value, max.Unit), f, c
}

	if err != nil && !os.IsNotExist(err) {
		t.Fatalf("reading go.sum after -testsum: %v", err)
	}
	switch {
	case os.IsNotExist(err) && gosumIdx >= 0:
		// go.sum was deleted.
		rewrite = true
		archive.Files = append(archive.Files[:gosumIdx], archive.Files[gosumIdx+1:]...)
	case err == nil && gosumIdx < 0:
		// go.sum was created.
		rewrite = true
		gosumIdx = gomodIdx + 1

// RemoveNumLabel removes all numerical labels associated with the specified key for all
// samples in the profile.
func (p *Profile) RemoveNumLabel(key string) {
	for _, sample := range p.Sample {
		delete(sample.NumLabel, key)
		delete(sample.NumUnit, key)
	}
}

// DiffBaseSample returns true if a sample belongs to the diff base and false
// otherwise.
func (s *Sample) DiffBaseSample() bool {

	// printed by 'go test' along with an error if the test binary terminates
	// with an error.
	bigFailErrorPrefix = []byte("FAIL\t")

	// an === NAME line with no test name, if trailing spaces are deleted
	emptyName     = []byte("=== NAME")
	emptyNameLine = []byte("=== NAME  \n")

	updates = [][]byte{
		[]byte("=== RUN   "),
		[]byte("=== PAUSE "),
		[]byte("=== CONT  "),
		[]byte("=== NAME  "),

	goldenLines := strings.Split(string(golden), "\n")
	outLines := strings.Split(out.String(), "\n")
	// Compare at the line level, stopping at first different line so
	// we don't generate tons of output if there's an inserted or deleted line.
	for i, goldenLine := range goldenLines {
		if i >= len(outLines) {
			t.Fatalf("output shorter than golden; stops before line %d: %s\n", i+1, goldenLine)
		}

	}
	if err != nil {
		f.Close()
		os.Remove(f.Name())
		return nil, err
	}
	return &deleteCloser{f}, nil
}

// deleteCloser is a file that gets deleted on Close.
type deleteCloser struct {
	*os.File
}

func (d *deleteCloser) Close() error {
	defer os.Remove(d.File.Name())
	return d.File.Close()
}

	for {
		progress := false
		for c, used := range s.copies {
			if !used && c.Uses == 0 {
				if s.f.pass.debug > regDebug {
					fmt.Printf("delete copied value %s\n", c.LongString())
				}
				c.resetArgs()
				f.freeValue(c)
				delete(s.copies, c)
				progress = true
			}
		}
		if !progress {
			break
		}
	}

	for _, b := range s.visitOrder {
		i := 0