// address where the first byte of the segment is loaded
		// (loadSegment.Vaddr). A file offset fx maps to a virtual (symbol) address
		// sx = fx - loadSegment.Off + loadSegment.Vaddr.
		//
		// Thus, a runtime virtual address x maps to a symbol address
		// sx = x - start + offset - loadSegment.Off + loadSegment.Vaddr.
		return start - offset + loadSegment.Off - loadSegment.Vaddr, nil
	}

		msect.align++
	}
	msect.addr = sect.Vaddr
	msect.size = sect.Length

	if sect.Vaddr < sect.Seg.Vaddr+sect.Seg.Filelen {
		// data in file
		if sect.Length > sect.Seg.Vaddr+sect.Seg.Filelen-sect.Vaddr {
			Errorf(nil, "macho cannot represent section %s crossing data and bss", sect.Name)
		}
		msect.off = uint32(sect.Seg.Fileoff + sect.Vaddr - sect.Seg.Vaddr)
	} else {
		msect.off = 0

				}
			}
		}
	} else if m, err2 := macho.Open(src); err2 == nil {
		for _, sec := range m.Sections {
			vaddr := sec.Addr
			paddr := uint64(sec.Offset)
			size := sec.Size
			for a := range virtualEdits {
				if a >= vaddr && a < vaddr+size {
					physicalEdits[paddr+(a-vaddr)] = true
				}
			}
		}
	} else {
		t.Log(err)
		t.Log(err2)
		t.Fatal("executable format not elf or macho")
	}

		// If main section has no bits, nothing to relocate.
		if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen {
			return 0
		}
		sect.Reloff = uint64(ctxt.Out.Offset())
		for i, s := range syms {
			if !ldr.AttrReachable(s) {
				continue
			}
			if uint64(ldr.SymValue(s)) >= sect.Vaddr {
				syms = syms[i:]
				break
			}
		}
		eaddr := int64(sect.Vaddr + sect.Length)
		for _, s := range syms {

type elfExe struct {
	f *elf.File
}

func (x *elfExe) ReadData(addr, size uint64) ([]byte, error) {
	for _, prog := range x.f.Progs {
		if prog.Vaddr <= addr && addr <= prog.Vaddr+prog.Filesz-1 {
			n := prog.Vaddr + prog.Filesz - addr
			if n > size {
				n = size
			}
			return saferio.ReadDataAt(prog, n, int64(addr-prog.Vaddr))
		}
	}
	return nil, errUnrecognizedFormat
}

	textbase := Segtext.Sections[0].Vaddr
	for _, sect := range Segtext.Sections {
		if sect.Name != ".text" {
			break
		}
		// The fields written should match runtime/symtab.go:textsect.
		// They are designed to minimize runtime calculations.
		vaddr := sect.Vaddr - textbase
		off = t.SetUint(ctxt.Arch, off, vaddr) // field vaddr
		end := vaddr + sect.Length

		return secs[i].Addr < secs[j].Addr
	})

	// Check to make sure we don't have any overlaps.
	foundOverlap := false
	for i := 0; i < len(secs)-1; i++ {
		for j := i + 1; j < len(secs); j++ {
			s := secs[i]
			sn := secs[j]
			if secOverlaps(s, sn) {
				t.Errorf("unexpected: section %d:%q (addr=%x size=%x) overlaps section %d:%q (addr=%x size=%x)", i, s.Name, s.Addr, s.Size, i+1, sn.Name, sn.Addr, sn.Size)

type functab struct {
	entryoff uint32 // relative to runtime.text
	funcoff  uint32
}

// Mapping information for secondary text sections

type textsect struct {
	vaddr    uintptr // prelinked section vaddr
	end      uintptr // vaddr + section length
	baseaddr uintptr // relocated section address
}

// findfuncbucket is an array of these structures.
// Each bucket represents 4096 bytes of the text segment.

		ldr.SymSect(ldr.Lookup("runtime.data", 0)),
	}

	dataSects = make([]wasmDataSect, len(sections))
	for i, sect := range sections {
		data := ld.DatblkBytes(ctxt, int64(sect.Vaddr), int64(sect.Length))
		dataSects[i] = wasmDataSect{sect, data}
	}
}

// asmb writes the final WebAssembly module binary.
// Spec: https://webassembly.github.io/spec/core/binary/modules.html

				Flags:  ProgFlag(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Flags):])),
				Off:    uint64(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Off):])),
				Vaddr:  uint64(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Vaddr):])),
				Paddr:  uint64(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Paddr):])),
				Filesz: uint64(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Filesz):])),
				Memsz:  uint64(bo.Uint32(phdata[off+unsafe.Offsetof(ph.Memsz):])),