private final class SlicedByteSource extends ByteSource {

    final long offset;
    final long length;

    SlicedByteSource(long offset, long length) {
      checkArgument(offset >= 0, "offset (%s) may not be negative", offset);
      checkArgument(length >= 0, "length (%s) may not be negative", length);
      this.offset = offset;
      this.length = length;
    }

    @Override

    private static long bytesToLong(byte[] bytes, int offset) {
        return (bytes[offset] & 0xFFL)
            | ((bytes[offset + 1] & 0xFFL) << 8)
            | ((bytes[offset + 2] & 0xFFL) << 16)
            | ((bytes[offset + 3] & 0xFFL) << 24)
            | ((bytes[offset + 4] & 0xFFL) << 32)
            | ((bytes[offset + 5] & 0xFFL) << 40)
            | ((bytes[offset + 6] & 0xFFL) << 48)

type objReader struct {
	a      *Archive
	b      *bio.Reader
	err    error
	offset int64
	limit  int64
	tmp    [256]byte
}

func (r *objReader) init(f *os.File) {
	r.a = &Archive{f, nil}
	r.offset, _ = f.Seek(0, io.SeekCurrent)
	r.limit, _ = f.Seek(0, io.SeekEnd)
	f.Seek(r.offset, io.SeekStart)
	r.b = bio.NewReader(f)
}

// error records that an error occurred.

	d.offset++
	return x
}

func (e *encoder) uint8(x uint8) {
	e.buf[e.offset] = x
	e.offset++
}

func (d *decoder) uint16() uint16 {
	x := d.order.Uint16(d.buf[d.offset : d.offset+2])
	d.offset += 2
	return x
}

func (e *encoder) uint16(x uint16) {
	e.order.PutUint16(e.buf[e.offset:e.offset+2], x)
	e.offset += 2
}

func (d *decoder) uint32() uint32 {

	for _, whence := range []int{SeekStart, SeekCurrent, SeekEnd} {
		for offset := int64(-3); offset <= 4; offset++ {
			brOff, brErr := br.Seek(offset, whence)
			srOff, srErr := sr.Seek(offset, whence)
			if (brErr != nil) != (srErr != nil) || brOff != srOff {
				t.Errorf("For whence %d, offset %d: bytes.Reader.Seek = (%v, %v) != SectionReader.Seek = (%v, %v)",
					whence, offset, brOff, brErr, srErr, srOff)
			}
		}
	}

	}
	out[0] = o0
}

// hashstp RB,offset(RA)
func type_hashstp(c *ctxt9, p *obj.Prog, t *Optab, out *[5]uint32) {
	o0 := GenOpcodes[p.As-AXXSETACCZ]
	o0 |= uint32(p.From.Reg&0x1f) << 11       // RB
	o0 |= uint32((p.To.Offset>>8)&0x1) << 0   // DX
	o0 |= uint32((p.To.Offset>>3)&0x1f) << 21 // D
	o0 |= uint32(p.To.Reg&0x1f) << 16         // RA
	if p.To.Offset&0xfffffe07 != 0xfffffe00 {

		return nil, fmt.Errorf("could not identify base for %s: %v", name, err)
	}

	if b.fast || (!b.addr2lineFound && !b.llvmSymbolizerFound) {
		return &fileNM{file: file{
			b:       b,
			name:    name,
			buildID: buildID,
			m:       &elfMapping{start: start, limit: limit, offset: offset, kernelOffset: kernelOffset},
		}}, nil
	}

			p.From.Offset = -p.From.Offset
			p.As = AADDC
		}

	case ASUB:
		if p.From.Type == obj.TYPE_CONST && isint32(-p.From.Offset) {
			p.From.Offset = -p.From.Offset
			p.As = AADD
		}
	}

	if c.ctxt.Flag_dynlink {
		c.rewriteToUseGot(p)
	}
}

// Rewrite p, if necessary, to access global data via the global offset table.
func (c *ctxtz) rewriteToUseGot(p *obj.Prog) {

				sh.Size = sh64.Size
				sh.Offset = sh64.Offset
				sh.Align = sh64.Align
				sh.Reloff = sh64.Reloff
				sh.Nreloc = sh64.Nreloc
				sh.Flags = sh64.Flags
				if err := f.pushSection(sh, r); err != nil {
					return nil, err
				}
			}
		}
		if s != nil {
			if int64(s.Offset) < 0 {
				return nil, &FormatError{offset, "invalid section offset", s.Offset}
			}
			if int64(s.Filesz) < 0 {

}

func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
	w.m.Lock()
	defer w.m.Unlock()

	if w.nextOffset == offset {
		n, err = w.w.Write(b)
		w.nextOffset += int64(n)
	} else {
		if offset > w.nextOffset+ftpMaxWriteOffset {
			return 0, fmt.Errorf("write offset %d is too far ahead of next offset %d", offset, w.nextOffset)
		}
		w.buffer[offset] = make([]byte, len(b))
		copy(w.buffer[offset], b)