b = append(b, s2b...)

	readStr := func(slr *Reader) string {
		len := slr.ReadULEB128()
		return slr.ReadString(int64(len))
	}

	for i := 0; i < 2; i++ {
		slr := NewReader(b, i == 0)
		g32 := slr.ReadUint32()
		if g32 != e32 {
			t.Fatalf("slr.ReadUint32() got %d want %d", g32, e32)
		}
		g64 := slr.ReadUint64()
		if g64 != e64 {
			t.Fatalf("slr.ReadUint64() got %d want %d", g64, e64)
		}

		return fmt.Errorf("error: short read on args table")
	}
	slr := slicereader.NewReader(b, false /* not readonly */)
	sget := func() (string, error) {
		kidx := slr.ReadULEB128()
		if int(kidx) >= cdr.stab.Entries() {
			return "", fmt.Errorf("malformed string table ref")
		}
		return cdr.stab.Get(uint32(kidx)), nil
	}
	nents := slr.ReadULEB128()
	cdr.args = make(map[string]string, int(nents))

	strtab *stringtab.Reader
	tmp    []byte
	debug  bool
}

func NewCoverageMetaDataDecoder(b []byte, readonly bool) (*CoverageMetaDataDecoder, error) {
	slr := slicereader.NewReader(b, readonly)
	x := &CoverageMetaDataDecoder{
		r:   slr,
		tmp: make([]byte, 0, 256),
	}
	if err := x.readHeader(); err != nil {
		return nil, err
	}
	if err := x.readStringTable(); err != nil {
		return nil, err
	}

	nr, err := r.fileRdr.Read(b)
	if err != nil {
		return err
	}
	if nr != int(r.hdr.StrTabLength) {
		return fmt.Errorf("error: short read on string table")
	}
	slr := slicereader.NewReader(b, false /* not readonly */)
	r.strtab = stringtab.NewReader(slr)
	r.strtab.Read()

	if r.debug {
		fmt.Fprintf(os.Stderr, "=-= read-in header is: %+v\n", *r)
	}

	return nil
}

type Optionals struct {
	Sr string `json:"sr"`
	So string `json:"so,omitempty"`
	Sw string `json:"-"`

	Ir int `json:"omitempty"` // actually named omitempty, not an option
	Io int `json:"io,omitempty"`

	Slr []string `json:"slr,random"`
	Slo []string `json:"slo,omitempty"`

	Mr map[string]any `json:"mr"`
	Mo map[string]any `json:",omitempty"`

	Fr float64 `json:"fr"`
	Fo float64 `json:"fo,omitempty"`

	Br bool `json:"br"`