blob: cef03fa323e6e8d4a5394b0bbd5b4fbc6220370f [file] [log] [blame]
// Copyright 2022 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 cov_test
import (
// visitor implements the CovDataVisitor interface in a very stripped
// down way, just keeps track of interesting events.
type visitor struct {
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) {
func (v *visitor) BeginCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int) {
func (v *visitor) EndCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int) {}
func (v *visitor) VisitFuncCounterData(payload decodecounter.FuncPayload) { v.funcCounterData++ }
func (v *visitor) EndCounters() {}
func (v *visitor) BeginPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32) {}
func (v *visitor) EndPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32) {}
func (v *visitor) VisitFunc(pkgIdx uint32, fnIdx uint32, fd *coverage.FuncDesc) { v.metaFuncCount++ }
func (v *visitor) Finish() {}
func TestIssue58411(t *testing.T) {
// Build a tiny test program with -cover. Smallness is important;
// it is one of the factors that triggers issue 58411.
d := t.TempDir()
exepath := filepath.Join(d, "small.exe")
path := filepath.Join("testdata", "small.go")
cmd := testenv.Command(t, testenv.GoToolPath(t), "build",
"-o", exepath, "-cover", path)
b, err := cmd.CombinedOutput()
if len(b) != 0 {
t.Logf("## build output:\n%s", b)
if err != nil {
t.Fatalf("build error: %v", err)
// Run to produce coverage data. Note the large argument; we need a large
// argument (more than 4k) to trigger the bug, but the overall file
// has to remain small (since large files will be read with mmap).
covdir := filepath.Join(d, "covdata")
if err = os.Mkdir(covdir, 0777); err != nil {
t.Fatalf("creating covdir: %v", err)
large := fmt.Sprintf("%07999d", 0)
cmd = testenv.Command(t, exepath, "1", "2", "3", large)
cmd.Dir = covdir
cmd.Env = append(os.Environ(), "GOCOVERDIR="+covdir)
b, err = cmd.CombinedOutput()
if err != nil {
t.Logf("## run output:\n%s", b)
t.Fatalf("build error: %v", err)
vis := &visitor{}
// Read resulting coverage data. Without the fix, this would
// yield a "short read" error.
const verbosityLevel = 0
const flags = 0
cdr := cov.MakeCovDataReader(vis, []string{covdir}, verbosityLevel, flags, nil)
err = cdr.Visit()
if err != nil {
t.Fatalf("visit failed: %v", err)
// make sure we saw a few things just for grins
const want = "{metaFileCount:1 counterFileCount:1 funcCounterData:1 metaFuncCount:1}"
got := fmt.Sprintf("%+v", *vis)
if want != got {
t.Errorf("visitor contents: want %v got %v\n", want, got)