// of its subexpressions to dstCap and returns dstCap.
//
// nil is returned if no matches are found and non-nil if matches are found.
func (re *Regexp) doExecute(r io.RuneReader, b []byte, s string, pos int, ncap int, dstCap []int) []int {
	if dstCap == nil {
		// Make sure 'return dstCap' is non-nil.
		dstCap = arrayNoInts[:0:0]
	}

	if r == nil && len(b)+len(s) < re.minInputLen {

				// Match must be leftmost; done.
				goto Match
			}
			_, width = i.step(pos)
		}
		freeBitState(b)
		return nil
	}

Match:
	dstCap = append(dstCap, b.matchcap...)
	freeBitState(b)
	return dstCap

	if bsrc != nil {
		endPos = len(bsrc)
	} else {
		endPos = len(src)
	}
	if nmatch > re.prog.NumCap {
		nmatch = re.prog.NumCap
	}

	var dstCap [2]int
	for searchPos <= endPos {
		a := re.doExecute(nil, bsrc, src, searchPos, nmatch, dstCap[:0])
		if len(a) == 0 {
			break // no more matches
		}

		// Copy the unmatched characters before this match.
		if bsrc != nil {

	res := []rtcov.CovCounterBlob{}
	u32sz := unsafe.Sizeof(uint32(0))
	for datap := &firstmoduledata; datap != nil; datap = datap.next {
		if datap.covctrs == datap.ecovctrs {
			continue
		}
		res = append(res, rtcov.CovCounterBlob{
			Counters: (*uint32)(unsafe.Pointer(datap.covctrs)),
			Len:      uint64((datap.ecovctrs - datap.covctrs) / u32sz),
		})
	}
	return res

	if base, _, _ := findObject(uintptr(p), 0, 0); base != 0 {
		return base
	}

	// data or bss
	for _, datap := range activeModules() {
		if datap.data <= uintptr(p) && uintptr(p) < datap.edata {
			return datap.data
		}
		if datap.bss <= uintptr(p) && uintptr(p) < datap.ebss {
			return datap.bss
		}
	}

	return 0

	for _, datap := range activeModules() {
		if cgoInRange(src, datap.data, datap.edata) {
			doff := uintptr(src) - datap.data
			cgoCheckBits(add(src, -doff), datap.gcdatamask.bytedata, off+doff, size)
			return
		}
		if cgoInRange(src, datap.bss, datap.ebss) {
			boff := uintptr(src) - datap.bss
			cgoCheckBits(add(src, -boff), datap.gcbssmask.bytedata, off+boff, size)
			return
		}

		if err == nil {
			devName := ""
			diskstats, _ := bfs.ProcDiskstats()
			for _, dstat := range diskstats {
				// ignore all loop devices
				if strings.HasPrefix(dstat.DeviceName, "loop") {
					continue
				}
				if dstat.MajorNumber == info.Major && dstat.MinorNumber == info.Minor {
					devName = dstat.DeviceName
					break
				}
			}
			if devName != "" {
				info.Name = devName

			f2 := funcInfo{(*_func)(unsafe.Pointer(&datap.pclntable[datap.ftab[i+1].funcoff])), datap}
			f2name := "end"
			if i+1 < nftab {
				f2name = funcname(f2)
			}
			println("function symbol table not sorted by PC offset:", hex(datap.ftab[i].entryoff), funcname(f1), ">", hex(datap.ftab[i+1].entryoff), f2name, ", plugin:", datap.pluginpath)
			for j := 0; j <= i; j++ {

	// stackObjectRecord.gcdata() will work correctly with it.
	ptr := uintptr(unsafe.Pointer(&methodValueCallFrameObjs[0]))
	var mod *moduledata
	for datap := &firstmoduledata; datap != nil; datap = datap.next {
		if datap.gofunc <= ptr && ptr < datap.end {
			mod = datap
			break
		}
	}
	if mod == nil {
		throw("methodValueCallFrameObjs is not in a module")
	}
	methodValueCallFrameObjs[0] = stackObjectRecord{

	// due to external linking.
	for datap := &firstmoduledata; datap != nil; datap = datap.next {
		if datap.noptrdata <= uintptr(p) && uintptr(p) < datap.enoptrdata ||
			datap.data <= uintptr(p) && uintptr(p) < datap.edata ||
			datap.bss <= uintptr(p) && uintptr(p) < datap.ebss ||
			datap.noptrbss <= uintptr(p) && uintptr(p) < datap.enoptrbss {
			return true
		}
	}
	return false
}