}
	fmt.Fprintf(os.Stderr, "usage: go tool covdata [command]\n")
	fmt.Fprintf(os.Stderr, `
Commands are:

textfmt     convert coverage data to textual format
percent     output total percentage of statements covered
pkglist     output list of package import paths
func        output coverage profile information for each function
merge       merge data files together
subtract    subtract one set of data files from another set

	tmpRefFlags goobj.RefFlags
	tmpRefName  goobj.RefName
}

// prepare package index list
func (w *writer) init() {
	w.pkglist = make([]string, len(w.ctxt.pkgIdx)+1)
	w.pkglist[0] = "" // dummy invalid package for index 0
	for pkg, i := range w.ctxt.pkgIdx {
		w.pkglist[i] = pkg
	}
}

func (w *writer) writeFile(ctxt *Link, file *FileInfo) {
	f, err := os.Open(file.Name)
	if err != nil {

	// Special handling for "any", whose representation may be changed by the
	// gotypesalias GODEBUG variable.
	p.typCache[uint64(len(predeclared))] = types.Universe.Lookup("any").Type()

	pkgList := make([]*types.Package, r.uint64())
	for i := range pkgList {
		pkgPathOff := r.uint64()
		pkgPath := p.stringAt(pkgPathOff)
		pkgName := p.stringAt(r.uint64())
		_ = r.uint64() // package height; unused by go/types

		if pkgPath == "" {

	for i := range s {
		s[i].Pkg = r.StringRef(off)
		copy(s[i].Fingerprint[:], r.BytesAt(off+stringRefSize, len(s[i].Fingerprint)))
		off += importedPkgSize
	}
	return s
}

func (r *Reader) Pkglist() []string {
	n := (r.h.Offsets[BlkPkgIdx+1] - r.h.Offsets[BlkPkgIdx]) / stringRefSize
	s := make([]string, n)
	off := r.h.Offsets[BlkPkgIdx]
	for i := range s {
		s[i] = r.StringRef(off)
		off += stringRefSize