out, err := ctxt.Out.View(sect.Reloff)
			if err != nil {
				panic(err)
			}
			go func() {
				relocSect(ctxt, out, sect, syms)
				wg.Done()
				<-sem
			}()
		}
	} else {
		// We cannot Mmap. Write sequentially.
		fn = func(ctxt *Link, sect *sym.Section, syms []loader.Sym) {
			relocSect(ctxt, ctxt.Out, sect, syms)
		}
	}
	return fn, &wg

	sizeExtRelocs(ctxt, thearch.MachorelocSize)
	relocSect, wg := relocSectFn(ctxt, machorelocsect)

	relocSect(ctxt, Segtext.Sections[0], ctxt.Textp)
	for _, sect := range Segtext.Sections[1:] {
		if sect.Name == ".text" {
			relocSect(ctxt, sect, ctxt.Textp)
		} else {
			relocSect(ctxt, sect, ctxt.datap)
		}
	}
	for _, sect := range Segrelrodata.Sections {
		relocSect(ctxt, sect, ctxt.datap)
	}

	}

	sizeExtRelocs(ctxt, thearch.ELF.RelocSize)
	relocSect, wg := relocSectFn(ctxt, elfrelocsect)

	for _, sect := range Segtext.Sections {
		if sect.Name == ".text" {
			relocSect(ctxt, sect, ctxt.Textp)
		} else {
			relocSect(ctxt, sect, ctxt.datap)
		}
	}

	for _, sect := range Segrodata.Sections {
		relocSect(ctxt, sect, ctxt.datap)
	}

func (f *peFile) emitRelocations(ctxt *Link) {
	for ctxt.Out.Offset()&7 != 0 {
		ctxt.Out.Write8(0)
	}

	ldr := ctxt.loader

	// relocsect relocates symbols from first in section sect, and returns
	// the total number of relocations emitted.
	relocsect := func(sect *sym.Section, syms []loader.Sym, base uint64) int {
		// If main section has no bits, nothing to relocate.
		if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen {

	ctxt.Out.SeekSet(fileoff)
	for ctxt.Out.Offset()&7 != 0 {
		ctxt.Out.Write8(0)
	}

	ldr := ctxt.loader
	// relocsect relocates symbols from first in section sect, and returns
	// the total number of relocations emitted.
	relocsect := func(sect *sym.Section, syms []loader.Sym, base uint64) uint32 {
		// ctxt.Logf("%s 0x%x\n", sect.Name, sect.Vaddr)

type RelocKind int32

// An Index represents a bitstream element index within a particular
// section.
type Index int32

// A relocEnt (relocation entry) is an entry in an element's local
// reference table.
//
// TODO(mdempsky): Rename this too.
type RelocEnt struct {
	Kind RelocKind
	Idx  Index
}

// Reserved indices within the meta relocation section.
const (
	PublicRootIdx  Index = 0

		pr.scratchRelocEnt = nil
	} else {
		r.Relocs = make([]RelocEnt, l)
	}
	for i := range r.Relocs {
		r.Sync(SyncReloc)
		r.Relocs[i] = RelocEnt{RelocKind(r.Len()), Index(r.Len())}
	}

	return r
}

// A Decoder provides methods for decoding an individual element's
// bitstream data.
type Decoder struct {
	common *PkgDecoder

	Relocs []RelocEnt
	Data   strings.Reader

	k   RelocKind

		p:   pw,
		k:   k,
		Idx: idx,
	}
}

// An Encoder provides methods for encoding an individual element's
// bitstream data.
type Encoder struct {
	p *PkgEncoder

	Relocs   []RelocEnt
	RelocMap map[RelocEnt]uint32
	Data     bytes.Buffer // accumulated element bitstream data

	encodingRelocHeader bool

	k   RelocKind
	Idx Index // index within relocation section
}