// and loadable (has an address), nonzero size.
	secs := []*elf.Section{}
	for _, s := range elfFile.Sections {
		if s.Type != elf.SHT_PROGBITS && s.Type != elf.SHT_DYNAMIC {
			continue
		}
		if s.Addr == 0 || s.Size == 0 {
			continue
		}
		secs = append(secs, s)
	}

	secOverlaps := func(s1, s2 *elf.Section) bool {
		st1 := s1.Addr
		st2 := s2.Addr

	switch tag {
	case DT_NEEDED, DT_SONAME, DT_RPATH, DT_RUNPATH:
	default:
		return nil, fmt.Errorf("non-string-valued tag %v", tag)
	}
	ds := f.SectionByType(SHT_DYNAMIC)
	if ds == nil {
		// not dynamic, so no libraries
		return nil, nil
	}
	d, err := ds.Data()
	if err != nil {
		return nil, err
	}

	dynSize := 8
	if f.Class == ELFCLASS64 {

	SHT_RELA           SectionType = 4          /* relocation section with addends */
	SHT_HASH           SectionType = 5          /* symbol hash table section */
	SHT_DYNAMIC        SectionType = 6          /* dynamic section */
	SHT_NOTE           SectionType = 7          /* note section */
	SHT_NOBITS         SectionType = 8          /* no space section */

		sh.Link = uint32(elfshname(".dynsym").shnum)
		shsym(sh, ldr, ldr.Lookup(".hash", 0))

		/* sh and elf.PT_DYNAMIC for .dynamic section */
		sh = elfshname(".dynamic")

		sh.Type = uint32(elf.SHT_DYNAMIC)
		sh.Flags = uint64(elf.SHF_ALLOC + elf.SHF_WRITE)
		sh.Entsize = 2 * uint64(ctxt.Arch.RegSize)
		sh.Addralign = uint64(ctxt.Arch.RegSize)
		sh.Link = uint32(elfshname(".dynstr").shnum)

		{"SHN_HIRESERVE", Const, 0},
		{"SHN_LOOS", Const, 0},
		{"SHN_LOPROC", Const, 0},
		{"SHN_LORESERVE", Const, 0},
		{"SHN_UNDEF", Const, 0},
		{"SHN_XINDEX", Const, 0},
		{"SHT_DYNAMIC", Const, 0},
		{"SHT_DYNSYM", Const, 0},
		{"SHT_FINI_ARRAY", Const, 0},
		{"SHT_GNU_ATTRIBUTES", Const, 0},
		{"SHT_GNU_HASH", Const, 0},
		{"SHT_GNU_LIBLIST", Const, 0},
		{"SHT_GNU_VERDEF", Const, 0},