2 files changed, 568 insertions, 0 deletions
diff --git a/src/internal/coverage/test/counter_test.go b/src/internal/coverage/test/counter_test.go
new file mode 100644
index 0000000..e29baed
--- /dev/null
+++ b/src/internal/coverage/test/counter_test.go
@@ -0,0 +1,237 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package test
+
+import (
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/decodecounter"
+	"internal/coverage/encodecounter"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+type ctrVis struct {
+	funcs []decodecounter.FuncPayload
+}
+
+func (v *ctrVis) VisitFuncs(f encodecounter.CounterVisitorFn) error {
+	for _, fn := range v.funcs {
+		if err := f(fn.PkgIdx, fn.FuncIdx, fn.Counters); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func mkfunc(p uint32, f uint32, c []uint32) decodecounter.FuncPayload {
+	return decodecounter.FuncPayload{
+		PkgIdx:   p,
+		FuncIdx:  f,
+		Counters: c,
+	}
+}
+
+func TestCounterDataWriterReader(t *testing.T) {
+	flavors := []coverage.CounterFlavor{
+		coverage.CtrRaw,
+		coverage.CtrULeb128,
+	}
+
+	isDead := func(fp decodecounter.FuncPayload) bool {
+		for _, v := range fp.Counters {
+			if v != 0 {
+				return false
+			}
+		}
+		return true
+	}
+
+	funcs := []decodecounter.FuncPayload{
+		mkfunc(0, 0, []uint32{13, 14, 15}),
+		mkfunc(0, 1, []uint32{16, 17}),
+		mkfunc(1, 0, []uint32{18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 976543, 7}),
+	}
+	writeVisitor := &ctrVis{funcs: funcs}
+
+	for kf, flav := range flavors {
+
+		t.Logf("testing flavor %d\n", flav)
+
+		// Open a counter data file in preparation for emitting data.
+		d := t.TempDir()
+		cfpath := filepath.Join(d, fmt.Sprintf("covcounters.hash.0.%d", kf))
+		of, err := os.OpenFile(cfpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
+		if err != nil {
+			t.Fatalf("opening covcounters: %v", err)
+		}
+
+		// Perform the encode and write.
+		cdfw := encodecounter.NewCoverageDataWriter(of, flav)
+		if cdfw == nil {
+			t.Fatalf("NewCoverageDataWriter failed")
+		}
+		finalHash := [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0}
+		args := map[string]string{"argc": "3", "argv0": "arg0", "argv1": "arg1", "argv2": "arg_________2"}
+		if err := cdfw.Write(finalHash, args, writeVisitor); err != nil {
+			t.Fatalf("counter file Write failed: %v", err)
+		}
+		if err := of.Close(); err != nil {
+			t.Fatalf("closing covcounters: %v", err)
+		}
+		cdfw = nil
+
+		// Decode the same file.
+		var cdr *decodecounter.CounterDataReader
+		inf, err := os.Open(cfpath)
+		defer func() {
+			if err := inf.Close(); err != nil {
+				t.Fatalf("close failed with: %v", err)
+			}
+		}()
+
+		if err != nil {
+			t.Fatalf("reopening covcounters file: %v", err)
+		}
+		if cdr, err = decodecounter.NewCounterDataReader(cfpath, inf); err != nil {
+			t.Fatalf("opening covcounters for read: %v", err)
+		}
+		decodedArgs := cdr.OsArgs()
+		aWant := "[arg0 arg1 arg_________2]"
+		aGot := fmt.Sprintf("%+v", decodedArgs)
+		if aWant != aGot {
+			t.Errorf("reading decoded args, got %s want %s", aGot, aWant)
+		}
+		for i := range funcs {
+			if isDead(funcs[i]) {
+				continue
+			}
+			var fp decodecounter.FuncPayload
+			if ok, err := cdr.NextFunc(&fp); err != nil {
+				t.Fatalf("reading func %d: %v", i, err)
+			} else if !ok {
+				t.Fatalf("reading func %d: bad return", i)
+			}
+			got := fmt.Sprintf("%+v", fp)
+			want := fmt.Sprintf("%+v", funcs[i])
+			if got != want {
+				t.Errorf("cdr.NextFunc iter %d\ngot  %+v\nwant %+v", i, got, want)
+			}
+		}
+		var dummy decodecounter.FuncPayload
+		if ok, err := cdr.NextFunc(&dummy); err != nil {
+			t.Fatalf("reading func after loop: %v", err)
+		} else if ok {
+			t.Fatalf("reading func after loop: expected EOF")
+		}
+	}
+}
+
+func TestCounterDataAppendSegment(t *testing.T) {
+	d := t.TempDir()
+	cfpath := filepath.Join(d, "covcounters.hash2.0")
+	of, err := os.OpenFile(cfpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
+	if err != nil {
+		t.Fatalf("opening covcounters: %v", err)
+	}
+
+	const numSegments = 2
+
+	// Write a counter with with multiple segments.
+	args := map[string]string{"argc": "1", "argv0": "prog.exe"}
+	allfuncs := [][]decodecounter.FuncPayload{}
+	ctrs := []uint32{}
+	q := uint32(0)
+	var cdfw *encodecounter.CoverageDataWriter
+	for idx := 0; idx < numSegments; idx++ {
+		args[fmt.Sprintf("seg%d", idx)] = "x"
+		q += 7
+		ctrs = append(ctrs, q)
+		funcs := []decodecounter.FuncPayload{}
+		for k := 0; k < idx+1; k++ {
+			c := make([]uint32, len(ctrs))
+			copy(c, ctrs)
+			funcs = append(funcs, mkfunc(uint32(idx), uint32(k), c))
+		}
+		allfuncs = append(allfuncs, funcs)
+
+		writeVisitor := &ctrVis{funcs: funcs}
+
+		if idx == 0 {
+			// Perform the encode and write.
+			cdfw = encodecounter.NewCoverageDataWriter(of, coverage.CtrRaw)
+			if cdfw == nil {
+				t.Fatalf("NewCoverageDataWriter failed")
+			}
+			finalHash := [16]byte{1, 2}
+			if err := cdfw.Write(finalHash, args, writeVisitor); err != nil {
+				t.Fatalf("counter file Write failed: %v", err)
+			}
+		} else {
+			if err := cdfw.AppendSegment(args, writeVisitor); err != nil {
+				t.Fatalf("counter file AppendSegment failed: %v", err)
+			}
+		}
+	}
+	if err := of.Close(); err != nil {
+		t.Fatalf("closing covcounters: %v", err)
+	}
+
+	// Read the result file.
+	var cdr *decodecounter.CounterDataReader
+	inf, err := os.Open(cfpath)
+	defer func() {
+		if err := inf.Close(); err != nil {
+			t.Fatalf("close failed with: %v", err)
+		}
+	}()
+
+	if err != nil {
+		t.Fatalf("reopening covcounters file: %v", err)
+	}
+	if cdr, err = decodecounter.NewCounterDataReader(cfpath, inf); err != nil {
+		t.Fatalf("opening covcounters for read: %v", err)
+	}
+	ns := cdr.NumSegments()
+	if ns != numSegments {
+		t.Fatalf("got %d segments want %d", ns, numSegments)
+	}
+	if len(allfuncs) != numSegments {
+		t.Fatalf("expected %d got %d", numSegments, len(allfuncs))
+	}
+
+	for sidx := 0; sidx < int(ns); sidx++ {
+		if off, err := inf.Seek(0, io.SeekCurrent); err != nil {
+			t.Fatalf("Seek failed: %v", err)
+		} else {
+			t.Logf("sidx=%d off=%d\n", sidx, off)
+		}
+
+		if sidx != 0 {
+			if ok, err := cdr.BeginNextSegment(); err != nil {
+				t.Fatalf("BeginNextSegment failed: %v", err)
+			} else if !ok {
+				t.Fatalf("BeginNextSegment return %v on iter %d",
+					ok, sidx)
+			}
+		}
+		funcs := allfuncs[sidx]
+		for i := range funcs {
+			var fp decodecounter.FuncPayload
+			if ok, err := cdr.NextFunc(&fp); err != nil {
+				t.Fatalf("reading func %d: %v", i, err)
+			} else if !ok {
+				t.Fatalf("reading func %d: bad return", i)
+			}
+			got := fmt.Sprintf("%+v", fp)
+			want := fmt.Sprintf("%+v", funcs[i])
+			if got != want {
+				t.Errorf("cdr.NextFunc iter %d\ngot  %+v\nwant %+v", i, got, want)
+			}
+		}
+	}
+}
diff --git a/src/internal/coverage/test/roundtrip_test.go b/src/internal/coverage/test/roundtrip_test.go
new file mode 100644
index 0000000..614f56e
--- /dev/null
+++ b/src/internal/coverage/test/roundtrip_test.go
@@ -0,0 +1,331 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package test
+
+import (
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/decodemeta"
+	"internal/coverage/encodemeta"
+	"internal/coverage/slicewriter"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func cmpFuncDesc(want, got coverage.FuncDesc) string {
+	swant := fmt.Sprintf("%+v", want)
+	sgot := fmt.Sprintf("%+v", got)
+	if swant == sgot {
+		return ""
+	}
+	return fmt.Sprintf("wanted %q got %q", swant, sgot)
+}
+
+func TestMetaDataEmptyPackage(t *testing.T) {
+	// Make sure that encoding/decoding works properly with packages
+	// that don't actually have any functions.
+	p := "empty/package"
+	pn := "package"
+	mp := "m"
+	b, err := encodemeta.NewCoverageMetaDataBuilder(p, pn, mp)
+	if err != nil {
+		t.Fatalf("making builder: %v", err)
+	}
+	drws := &slicewriter.WriteSeeker{}
+	b.Emit(drws)
+	drws.Seek(0, io.SeekStart)
+	dec, err := decodemeta.NewCoverageMetaDataDecoder(drws.BytesWritten(), false)
+	if err != nil {
+		t.Fatalf("making decoder: %v", err)
+	}
+	nf := dec.NumFuncs()
+	if nf != 0 {
+		t.Errorf("dec.NumFuncs(): got %d want %d", nf, 0)
+	}
+	pp := dec.PackagePath()
+	if pp != p {
+		t.Errorf("dec.PackagePath(): got %s want %s", pp, p)
+	}
+	ppn := dec.PackageName()
+	if ppn != pn {
+		t.Errorf("dec.PackageName(): got %s want %s", ppn, pn)
+	}
+	pmp := dec.ModulePath()
+	if pmp != mp {
+		t.Errorf("dec.ModulePath(): got %s want %s", pmp, mp)
+	}
+}
+
+func TestMetaDataEncoderDecoder(t *testing.T) {
+	// Test encode path.
+	pp := "foo/bar/pkg"
+	pn := "pkg"
+	mp := "barmod"
+	b, err := encodemeta.NewCoverageMetaDataBuilder(pp, pn, mp)
+	if err != nil {
+		t.Fatalf("making builder: %v", err)
+	}
+	f1 := coverage.FuncDesc{
+		Funcname: "func",
+		Srcfile:  "foo.go",
+		Units: []coverage.CoverableUnit{
+			coverage.CoverableUnit{StLine: 1, StCol: 2, EnLine: 3, EnCol: 4, NxStmts: 5},
+			coverage.CoverableUnit{StLine: 6, StCol: 7, EnLine: 8, EnCol: 9, NxStmts: 10},
+		},
+	}
+	idx := b.AddFunc(f1)
+	if idx != 0 {
+		t.Errorf("b.AddFunc(f1) got %d want %d", idx, 0)
+	}
+
+	f2 := coverage.FuncDesc{
+		Funcname: "xfunc",
+		Srcfile:  "bar.go",
+		Units: []coverage.CoverableUnit{
+			coverage.CoverableUnit{StLine: 1, StCol: 2, EnLine: 3, EnCol: 4, NxStmts: 5},
+			coverage.CoverableUnit{StLine: 6, StCol: 7, EnLine: 8, EnCol: 9, NxStmts: 10},
+			coverage.CoverableUnit{StLine: 11, StCol: 12, EnLine: 13, EnCol: 14, NxStmts: 15},
+		},
+	}
+	idx = b.AddFunc(f2)
+	if idx != 1 {
+		t.Errorf("b.AddFunc(f2) got %d want %d", idx, 0)
+	}
+
+	// Emit into a writer.
+	drws := &slicewriter.WriteSeeker{}
+	b.Emit(drws)
+
+	// Test decode path.
+	drws.Seek(0, io.SeekStart)
+	dec, err := decodemeta.NewCoverageMetaDataDecoder(drws.BytesWritten(), false)
+	if err != nil {
+		t.Fatalf("NewCoverageMetaDataDecoder error: %v", err)
+	}
+	nf := dec.NumFuncs()
+	if nf != 2 {
+		t.Errorf("dec.NumFuncs(): got %d want %d", nf, 2)
+	}
+
+	gotpp := dec.PackagePath()
+	if gotpp != pp {
+		t.Errorf("packagepath: got %s want %s", gotpp, pp)
+	}
+	gotpn := dec.PackageName()
+	if gotpn != pn {
+		t.Errorf("packagename: got %s want %s", gotpn, pn)
+	}
+
+	cases := []coverage.FuncDesc{f1, f2}
+	for i := uint32(0); i < uint32(len(cases)); i++ {
+		var fn coverage.FuncDesc
+		if err := dec.ReadFunc(i, &fn); err != nil {
+			t.Fatalf("err reading function %d: %v", i, err)
+		}
+		res := cmpFuncDesc(cases[i], fn)
+		if res != "" {
+			t.Errorf("ReadFunc(%d): %s", i, res)
+		}
+	}
+}
+
+func createFuncs(i int) []coverage.FuncDesc {
+	res := []coverage.FuncDesc{}
+	lc := uint32(1)
+	for fi := 0; fi < i+1; fi++ {
+		units := []coverage.CoverableUnit{}
+		for ui := 0; ui < (fi+1)*(i+1); ui++ {
+			units = append(units,
+				coverage.CoverableUnit{StLine: lc, StCol: lc + 1,
+					EnLine: lc + 2, EnCol: lc + 3, NxStmts: lc + 4,
+				})
+			lc += 5
+		}
+		f := coverage.FuncDesc{
+			Funcname: fmt.Sprintf("func_%d_%d", i, fi),
+			Srcfile:  fmt.Sprintf("foo_%d.go", i),
+			Units:    units,
+		}
+		res = append(res, f)
+	}
+	return res
+}
+
+func createBlob(t *testing.T, i int) []byte {
+	nomodule := ""
+	b, err := encodemeta.NewCoverageMetaDataBuilder("foo/pkg", "pkg", nomodule)
+	if err != nil {
+		t.Fatalf("making builder: %v", err)
+	}
+
+	funcs := createFuncs(i)
+	for _, f := range funcs {
+		b.AddFunc(f)
+	}
+	drws := &slicewriter.WriteSeeker{}
+	b.Emit(drws)
+	return drws.BytesWritten()
+}
+
+func createMetaDataBlobs(t *testing.T, nb int) [][]byte {
+	res := [][]byte{}
+	for i := 0; i < nb; i++ {
+		res = append(res, createBlob(t, i))
+	}
+	return res
+}
+
+func TestMetaDataWriterReader(t *testing.T) {
+	d := t.TempDir()
+
+	// Emit a meta-file...
+	mfpath := filepath.Join(d, "covmeta.hash.0")
+	of, err := os.OpenFile(mfpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
+	if err != nil {
+		t.Fatalf("opening covmeta: %v", err)
+	}
+	//t.Logf("meta-file path is %s", mfpath)
+	blobs := createMetaDataBlobs(t, 7)
+	gran := coverage.CtrGranularityPerBlock
+	mfw := encodemeta.NewCoverageMetaFileWriter(mfpath, of)
+	finalHash := [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+	err = mfw.Write(finalHash, blobs, coverage.CtrModeAtomic, gran)
+	if err != nil {
+		t.Fatalf("writing meta-file: %v", err)
+	}
+	if err = of.Close(); err != nil {
+		t.Fatalf("closing meta-file: %v", err)
+	}
+
+	// ... then read it back in, first time without setting fileView,
+	// second time setting it.
+	for k := 0; k < 2; k++ {
+		var fileView []byte
+
+		inf, err := os.Open(mfpath)
+		if err != nil {
+			t.Fatalf("open() on meta-file: %v", err)
+		}
+
+		if k != 0 {
+			// Use fileview to exercise different paths in reader.
+			fi, err := os.Stat(mfpath)
+			if err != nil {
+				t.Fatalf("stat() on meta-file: %v", err)
+			}
+			fileView = make([]byte, fi.Size())
+			if _, err := inf.Read(fileView); err != nil {
+				t.Fatalf("read() on meta-file: %v", err)
+			}
+			if _, err := inf.Seek(int64(0), io.SeekStart); err != nil {
+				t.Fatalf("seek() on meta-file: %v", err)
+			}
+		}
+
+		mfr, err := decodemeta.NewCoverageMetaFileReader(inf, fileView)
+		if err != nil {
+			t.Fatalf("k=%d NewCoverageMetaFileReader failed with: %v", k, err)
+		}
+		np := mfr.NumPackages()
+		if np != 7 {
+			t.Fatalf("k=%d wanted 7 packages got %d", k, np)
+		}
+		md := mfr.CounterMode()
+		wmd := coverage.CtrModeAtomic
+		if md != wmd {
+			t.Fatalf("k=%d wanted mode %d got %d", k, wmd, md)
+		}
+		gran := mfr.CounterGranularity()
+		wgran := coverage.CtrGranularityPerBlock
+		if gran != wgran {
+			t.Fatalf("k=%d wanted gran %d got %d", k, wgran, gran)
+		}
+
+		payload := []byte{}
+		for pi := 0; pi < int(np); pi++ {
+			var pd *decodemeta.CoverageMetaDataDecoder
+			var err error
+			pd, payload, err = mfr.GetPackageDecoder(uint32(pi), payload)
+			if err != nil {
+				t.Fatalf("GetPackageDecoder(%d) failed with: %v", pi, err)
+			}
+			efuncs := createFuncs(pi)
+			nf := pd.NumFuncs()
+			if len(efuncs) != int(nf) {
+				t.Fatalf("decoding pk %d wanted %d funcs got %d",
+					pi, len(efuncs), nf)
+			}
+			var f coverage.FuncDesc
+			for fi := 0; fi < int(nf); fi++ {
+				if err := pd.ReadFunc(uint32(fi), &f); err != nil {
+					t.Fatalf("ReadFunc(%d) pk %d got error %v",
+						fi, pi, err)
+				}
+				res := cmpFuncDesc(efuncs[fi], f)
+				if res != "" {
+					t.Errorf("ReadFunc(%d) pk %d: %s", fi, pi, res)
+				}
+			}
+		}
+		inf.Close()
+	}
+}
+
+func TestMetaDataDecodeLitFlagIssue57942(t *testing.T) {
+
+	// Encode a package with a few functions. The funcs alternate
+	// between regular functions and function literals.
+	pp := "foo/bar/pkg"
+	pn := "pkg"
+	mp := "barmod"
+	b, err := encodemeta.NewCoverageMetaDataBuilder(pp, pn, mp)
+	if err != nil {
+		t.Fatalf("making builder: %v", err)
+	}
+	const NF = 6
+	const NCU = 1
+	ln := uint32(10)
+	wantfds := []coverage.FuncDesc{}
+	for fi := uint32(0); fi < NF; fi++ {
+		fis := fmt.Sprintf("%d", fi)
+		fd := coverage.FuncDesc{
+			Funcname: "func" + fis,
+			Srcfile:  "foo" + fis + ".go",
+			Units: []coverage.CoverableUnit{
+				coverage.CoverableUnit{StLine: ln + 1, StCol: 2, EnLine: ln + 3, EnCol: 4, NxStmts: fi + 2},
+			},
+			Lit: (fi % 2) == 0,
+		}
+		wantfds = append(wantfds, fd)
+		b.AddFunc(fd)
+	}
+
+	// Emit into a writer.
+	drws := &slicewriter.WriteSeeker{}
+	b.Emit(drws)
+
+	// Decode the result.
+	drws.Seek(0, io.SeekStart)
+	dec, err := decodemeta.NewCoverageMetaDataDecoder(drws.BytesWritten(), false)
+	if err != nil {
+		t.Fatalf("making decoder: %v", err)
+	}
+	nf := dec.NumFuncs()
+	if nf != NF {
+		t.Fatalf("decoder number of functions: got %d want %d", nf, NF)
+	}
+	var fn coverage.FuncDesc
+	for i := uint32(0); i < uint32(NF); i++ {
+		if err := dec.ReadFunc(i, &fn); err != nil {
+			t.Fatalf("err reading function %d: %v", i, err)
+		}
+		res := cmpFuncDesc(wantfds[i], fn)
+		if res != "" {
+			t.Errorf("ReadFunc(%d): %s", i, res)
+		}
+	}
+}