sr := io.NewSectionReader(r, 0, 1<<63-1)
	// Read XCOFF target machine
	var magic uint16
	if err := binary.Read(sr, binary.BigEndian, &magic); err != nil {
		return nil, err
	}
	if magic != U802TOCMAGIC && magic != U64_TOCMAGIC {
		return nil, fmt.Errorf("unrecognised XCOFF magic: 0x%x", magic)
	}

	f := new(File)
	f.TargetMachine = magic

	// Read XCOFF file header

)

type fileTest struct {
	file     string
	hdr      FileHeader
	sections []*SectionHeader
	needed   []string
}

var fileTests = []fileTest{
	{
		"testdata/gcc-ppc32-aix-dwarf2-exec",
		FileHeader{U802TOCMAGIC},
		[]*SectionHeader{
			{".text", 0x10000290, 0x00000bbd, STYP_TEXT, 0x7ae6, 0x36},
			{".data", 0x20000e4d, 0x00000437, STYP_DATA, 0x7d02, 0x2b},
			{".bss", 0x20001284, 0x0000021c, STYP_BSS, 0, 0},

	data, err := sect.Data()
	if err != nil {
		return nil, err
	}
	return data[ssym.Value:esym.Value], nil
}

func (f *xcoffFile) goarch() string {
	switch f.xcoff.TargetMachine {
	case xcoff.U802TOCMAGIC:
		return "ppc"
	case xcoff.U64_TOCMAGIC:
		return "ppc64"
	}
	return ""
}

func (f *xcoffFile) loadAddress() (uint64, error) {
	return 0, fmt.Errorf("unknown load address")
}

	Fopthdr  uint16 // Number of bytes in optional header
	Fflags   uint16 // Flags
	Fnsyms   uint32 // Number of entries in symbol table
}

const (
	FILHSZ_32 = 20
	FILHSZ_64 = 24
)
const (
	U802TOCMAGIC = 0737 // AIX 32-bit XCOFF
	U64_TOCMAGIC = 0767 // AIX 64-bit XCOFF
)

// Flags that describe the type of the object file.
const (
	F_RELFLG    = 0x0001
	F_EXEC      = 0x0002
	F_LNNO      = 0x0004