// building. They are used to mark duplicate entries.
		files := make(map[string]int)
		knownDirs := make(map[string]int)

		// dirs[name] is true if name is known to be a directory,
		// because it appears as a prefix in a path.
		dirs := make(map[string]bool)

		for _, file := range r.File {
			isDir := len(file.Name) > 0 && file.Name[len(file.Name)-1] == '/'
			name := toValidName(file.Name)

		}
		if e == nil {
			break
		}
		switch e.Tag {
		case dwarf.TagVariable:
			name, _ := e.Val(dwarf.AttrName).(string)
			// As of https://reviews.llvm.org/D123534, clang
			// now emits DW_TAG_variable DIEs that have
			// no name (so as to be able to describe the
			// type and source locations of constant strings)
			// like the second arg in the call below:
			//
			//     myfunction(42, "foo")
			//