return &metaMerge{
		pkm:    make(map[string]*pkstate),
		astate: &argstate{},
	}
}

func (mm *metaMerge) visitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
	dbgtrace(2, "visitMetaDataFile(mdf=%s)", mdf)

	// Record meta-data file name.
	mm.pod.mdf = mdf
	// Keep a pointer to the file-level reader.
	mm.pod.mfr = mfr
	// Record file hash.
	mm.pod.fileHash = mfr.FileHash()

		}
		// Mode clashes are treated as errors if we're using the
		// default strict policy.
		if cm.cmode != cmode {
			if cm.policy == ModeMergeStrict {
				return fmt.Errorf("counter mode clash while reading meta-data file %s: previous file had %s, new file has %s", mdf, cm.cmode.String(), cmode.String())
			}

func (m *mstate) VisitFuncCounterData(data decodecounter.FuncPayload) {
	m.mm.visitFuncCounterData(data)
}

func (m *mstate) EndCounters() {
}

func (m *mstate) VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
	m.mm.visitMetaDataFile(mdf, mfr)
}

func (m *mstate) BeginPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32) {
	dbgtrace(3, "VisitPackage(pk=%d path=%s)", pkgIdx, pd.PackagePath())

			iters:    1,
			overflow: true,
		},
	}

	for k, scenario := range scenarios {
		var err error
		var ovf bool
		m := &cmerge.Merger{}
		mdf := fmt.Sprintf("file%d", k)
		err = m.SetModeAndGranularity(mdf, scenario.cmode, scenario.cgran)
		if err != nil {
			t.Fatalf("case %d SetModeAndGranularity failed: %v", k, err)
		}
		for i := 0; i < scenario.iters; i++ {

				if data.Counters[i] == 0 {
					val.Counters[i] = 0
				}
			}
		}
	}
}

func (s *sstate) VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
	if s.mode == intersectMode {
		s.imm = make(map[pkfunc]struct{})
	}
	s.mm.visitMetaDataFile(mdf, mfr)
}

func (s *sstate) BeginPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32) {
	s.mm.visitPackage(pd, pkgIdx, false)
}

	}
	d.mm[key] = val
}

func (d *dstate) EndCounters() {
}

func (d *dstate) VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
	newgran := mfr.CounterGranularity()
	newmode := mfr.CounterMode()
	if err := d.cm.SetModeAndGranularity(mdf, newmode, newgran); err != nil {
		fatal("%v", err)
	}
	if d.cmd == debugDumpMode {
		fmt.Printf("Cover mode: %s\n", newmode.String())

	metaFileCount    int
	counterFileCount int
	funcCounterData  int
	metaFuncCount    int
}

func (v *visitor) BeginPod(p pods.Pod) {}
func (v *visitor) EndPod(p pods.Pod)   {}
func (v *visitor) VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
	v.metaFileCount++
}
func (v *visitor) BeginCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int) {
	v.counterFileCount++
}

	// that correspond to it).
	BeginPod(p pods.Pod)
	EndPod(p pods.Pod)

	// Invoked when the reader is starting to examine the meta-data
	// file for a pod. Here 'mdf' is the path of the file, and 'mfr'
	// is an open meta-data reader.
	VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader)

	// Invoked when the reader processes a counter data file, first
	// the 'begin' method at the start, then the 'end' method when

application/access             mdf              # Microsoft Access
#application/excel              xls              # Microsoft Excel
application/vnd.ms-excel       xls              # Microsoft Excel
application/font-tdpfr         pfr              # TrueDoc Portable Font Resource
application/futuresplash       spl              # Macromedia Flash
application/hep                hep              # Hummingbird Host Explorer Profiles