Adding upstream version 1.20.14.upstream/1.20.14upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 729 insertions, 0 deletions

diff --git a/src/testing/fuzz.go b/src/testing/fuzz.go
new file mode 100644
index 0000000..d31a3f8
--- /dev/null
+++ b/src/testing/fuzz.go
@@ -0,0 +1,729 @@
+// Copyright 2020 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 testing
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"strings"
+	"time"
+)
+
+func initFuzzFlags() {
+	matchFuzz = flag.String("test.fuzz", "", "run the fuzz test matching `regexp`")
+	flag.Var(&fuzzDuration, "test.fuzztime", "time to spend fuzzing; default is to run indefinitely")
+	flag.Var(&minimizeDuration, "test.fuzzminimizetime", "time to spend minimizing a value after finding a failing input")
+
+	fuzzCacheDir = flag.String("test.fuzzcachedir", "", "directory where interesting fuzzing inputs are stored (for use only by cmd/go)")
+	isFuzzWorker = flag.Bool("test.fuzzworker", false, "coordinate with the parent process to fuzz random values (for use only by cmd/go)")
+}
+
+var (
+	matchFuzz        *string
+	fuzzDuration     durationOrCountFlag
+	minimizeDuration = durationOrCountFlag{d: 60 * time.Second, allowZero: true}
+	fuzzCacheDir     *string
+	isFuzzWorker     *bool
+
+	// corpusDir is the parent directory of the fuzz test's seed corpus within
+	// the package.
+	corpusDir = "testdata/fuzz"
+)
+
+// fuzzWorkerExitCode is used as an exit code by fuzz worker processes after an
+// internal error. This distinguishes internal errors from uncontrolled panics
+// and other failures. Keep in sync with internal/fuzz.workerExitCode.
+const fuzzWorkerExitCode = 70
+
+// InternalFuzzTarget is an internal type but exported because it is
+// cross-package; it is part of the implementation of the "go test" command.
+type InternalFuzzTarget struct {
+	Name string
+	Fn   func(f *F)
+}
+
+// F is a type passed to fuzz tests.
+//
+// Fuzz tests run generated inputs against a provided fuzz target, which can
+// find and report potential bugs in the code being tested.
+//
+// A fuzz test runs the seed corpus by default, which includes entries provided
+// by (*F).Add and entries in the testdata/fuzz/<FuzzTestName> directory. After
+// any necessary setup and calls to (*F).Add, the fuzz test must then call
+// (*F).Fuzz to provide the fuzz target. See the testing package documentation
+// for an example, and see the F.Fuzz and F.Add method documentation for
+// details.
+//
+// *F methods can only be called before (*F).Fuzz. Once the test is
+// executing the fuzz target, only (*T) methods can be used. The only *F methods
+// that are allowed in the (*F).Fuzz function are (*F).Failed and (*F).Name.
+type F struct {
+	common
+	fuzzContext *fuzzContext
+	testContext *testContext
+
+	// inFuzzFn is true when the fuzz function is running. Most F methods cannot
+	// be called when inFuzzFn is true.
+	inFuzzFn bool
+
+	// corpus is a set of seed corpus entries, added with F.Add and loaded
+	// from testdata.
+	corpus []corpusEntry
+
+	result     fuzzResult
+	fuzzCalled bool
+}
+
+var _ TB = (*F)(nil)
+
+// corpusEntry is an alias to the same type as internal/fuzz.CorpusEntry.
+// We use a type alias because we don't want to export this type, and we can't
+// import internal/fuzz from testing.
+type corpusEntry = struct {
+	Parent     string
+	Path       string
+	Data       []byte
+	Values     []any
+	Generation int
+	IsSeed     bool
+}
+
+// Helper marks the calling function as a test helper function.
+// When printing file and line information, that function will be skipped.
+// Helper may be called simultaneously from multiple goroutines.
+func (f *F) Helper() {
+	if f.inFuzzFn {
+		panic("testing: f.Helper was called inside the fuzz target, use t.Helper instead")
+	}
+
+	// common.Helper is inlined here.
+	// If we called it, it would mark F.Helper as the helper
+	// instead of the caller.
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	if f.helperPCs == nil {
+		f.helperPCs = make(map[uintptr]struct{})
+	}
+	// repeating code from callerName here to save walking a stack frame
+	var pc [1]uintptr
+	n := runtime.Callers(2, pc[:]) // skip runtime.Callers + Helper
+	if n == 0 {
+		panic("testing: zero callers found")
+	}
+	if _, found := f.helperPCs[pc[0]]; !found {
+		f.helperPCs[pc[0]] = struct{}{}
+		f.helperNames = nil // map will be recreated next time it is needed
+	}
+}
+
+// Fail marks the function as having failed but continues execution.
+func (f *F) Fail() {
+	// (*F).Fail may be called by (*T).Fail, which we should allow. However, we
+	// shouldn't allow direct (*F).Fail calls from inside the (*F).Fuzz function.
+	if f.inFuzzFn {
+		panic("testing: f.Fail was called inside the fuzz target, use t.Fail instead")
+	}
+	f.common.Helper()
+	f.common.Fail()
+}
+
+// Skipped reports whether the test was skipped.
+func (f *F) Skipped() bool {
+	// (*F).Skipped may be called by tRunner, which we should allow. However, we
+	// shouldn't allow direct (*F).Skipped calls from inside the (*F).Fuzz function.
+	if f.inFuzzFn {
+		panic("testing: f.Skipped was called inside the fuzz target, use t.Skipped instead")
+	}
+	f.common.Helper()
+	return f.common.Skipped()
+}
+
+// Add will add the arguments to the seed corpus for the fuzz test. This will be
+// a no-op if called after or within the fuzz target, and args must match the
+// arguments for the fuzz target.
+func (f *F) Add(args ...any) {
+	var values []any
+	for i := range args {
+		if t := reflect.TypeOf(args[i]); !supportedTypes[t] {
+			panic(fmt.Sprintf("testing: unsupported type to Add %v", t))
+		}
+		values = append(values, args[i])
+	}
+	f.corpus = append(f.corpus, corpusEntry{Values: values, IsSeed: true, Path: fmt.Sprintf("seed#%d", len(f.corpus))})
+}
+
+// supportedTypes represents all of the supported types which can be fuzzed.
+var supportedTypes = map[reflect.Type]bool{
+	reflect.TypeOf(([]byte)("")):  true,
+	reflect.TypeOf((string)("")):  true,
+	reflect.TypeOf((bool)(false)): true,
+	reflect.TypeOf((byte)(0)):     true,
+	reflect.TypeOf((rune)(0)):     true,
+	reflect.TypeOf((float32)(0)):  true,
+	reflect.TypeOf((float64)(0)):  true,
+	reflect.TypeOf((int)(0)):      true,
+	reflect.TypeOf((int8)(0)):     true,
+	reflect.TypeOf((int16)(0)):    true,
+	reflect.TypeOf((int32)(0)):    true,
+	reflect.TypeOf((int64)(0)):    true,
+	reflect.TypeOf((uint)(0)):     true,
+	reflect.TypeOf((uint8)(0)):    true,
+	reflect.TypeOf((uint16)(0)):   true,
+	reflect.TypeOf((uint32)(0)):   true,
+	reflect.TypeOf((uint64)(0)):   true,
+}
+
+// Fuzz runs the fuzz function, ff, for fuzz testing. If ff fails for a set of
+// arguments, those arguments will be added to the seed corpus.
+//
+// ff must be a function with no return value whose first argument is *T and
+// whose remaining arguments are the types to be fuzzed.
+// For example:
+//
+//	f.Fuzz(func(t *testing.T, b []byte, i int) { ... })
+//
+// The following types are allowed: []byte, string, bool, byte, rune, float32,
+// float64, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64.
+// More types may be supported in the future.
+//
+// ff must not call any *F methods, e.g. (*F).Log, (*F).Error, (*F).Skip. Use
+// the corresponding *T method instead. The only *F methods that are allowed in
+// the (*F).Fuzz function are (*F).Failed and (*F).Name.
+//
+// This function should be fast and deterministic, and its behavior should not
+// depend on shared state. No mutatable input arguments, or pointers to them,
+// should be retained between executions of the fuzz function, as the memory
+// backing them may be mutated during a subsequent invocation. ff must not
+// modify the underlying data of the arguments provided by the fuzzing engine.
+//
+// When fuzzing, F.Fuzz does not return until a problem is found, time runs out
+// (set with -fuzztime), or the test process is interrupted by a signal. F.Fuzz
+// should be called exactly once, unless F.Skip or F.Fail is called beforehand.
+func (f *F) Fuzz(ff any) {
+	if f.fuzzCalled {
+		panic("testing: F.Fuzz called more than once")
+	}
+	f.fuzzCalled = true
+	if f.failed {
+		return
+	}
+	f.Helper()
+
+	// ff should be in the form func(*testing.T, ...interface{})
+	fn := reflect.ValueOf(ff)
+	fnType := fn.Type()
+	if fnType.Kind() != reflect.Func {
+		panic("testing: F.Fuzz must receive a function")
+	}
+	if fnType.NumIn() < 2 || fnType.In(0) != reflect.TypeOf((*T)(nil)) {
+		panic("testing: fuzz target must receive at least two arguments, where the first argument is a *T")
+	}
+	if fnType.NumOut() != 0 {
+		panic("testing: fuzz target must not return a value")
+	}
+
+	// Save the types of the function to compare against the corpus.
+	var types []reflect.Type
+	for i := 1; i < fnType.NumIn(); i++ {
+		t := fnType.In(i)
+		if !supportedTypes[t] {
+			panic(fmt.Sprintf("testing: unsupported type for fuzzing %v", t))
+		}
+		types = append(types, t)
+	}
+
+	// Load the testdata seed corpus. Check types of entries in the testdata
+	// corpus and entries declared with F.Add.
+	//
+	// Don't load the seed corpus if this is a worker process; we won't use it.
+	if f.fuzzContext.mode != fuzzWorker {
+		for _, c := range f.corpus {
+			if err := f.fuzzContext.deps.CheckCorpus(c.Values, types); err != nil {
+				// TODO(#48302): Report the source location of the F.Add call.
+				f.Fatal(err)
+			}
+		}
+
+		// Load seed corpus
+		c, err := f.fuzzContext.deps.ReadCorpus(filepath.Join(corpusDir, f.name), types)
+		if err != nil {
+			f.Fatal(err)
+		}
+		for i := range c {
+			c[i].IsSeed = true // these are all seed corpus values
+			if f.fuzzContext.mode == fuzzCoordinator {
+				// If this is the coordinator process, zero the values, since we don't need
+				// to hold onto them.
+				c[i].Values = nil
+			}
+		}
+
+		f.corpus = append(f.corpus, c...)
+	}
+
+	// run calls fn on a given input, as a subtest with its own T.
+	// run is analogous to T.Run. The test filtering and cleanup works similarly.
+	// fn is called in its own goroutine.
+	run := func(captureOut io.Writer, e corpusEntry) (ok bool) {
+		if e.Values == nil {
+			// The corpusEntry must have non-nil Values in order to run the
+			// test. If Values is nil, it is a bug in our code.
+			panic(fmt.Sprintf("corpus file %q was not unmarshaled", e.Path))
+		}
+		if shouldFailFast() {
+			return true
+		}
+		testName := f.name
+		if e.Path != "" {
+			testName = fmt.Sprintf("%s/%s", testName, filepath.Base(e.Path))
+		}
+		if f.testContext.isFuzzing {
+			// Don't preserve subtest names while fuzzing. If fn calls T.Run,
+			// there will be a very large number of subtests with duplicate names,
+			// which will use a large amount of memory. The subtest names aren't
+			// useful since there's no way to re-run them deterministically.
+			f.testContext.match.clearSubNames()
+		}
+
+		// Record the stack trace at the point of this call so that if the subtest
+		// function - which runs in a separate stack - is marked as a helper, we can
+		// continue walking the stack into the parent test.
+		var pc [maxStackLen]uintptr
+		n := runtime.Callers(2, pc[:])
+		t := &T{
+			common: common{
+				barrier: make(chan bool),
+				signal:  make(chan bool),
+				name:    testName,
+				parent:  &f.common,
+				level:   f.level + 1,
+				creator: pc[:n],
+				chatty:  f.chatty,
+			},
+			context: f.testContext,
+		}
+		if captureOut != nil {
+			// t.parent aliases f.common.
+			t.parent.w = captureOut
+		}
+		t.w = indenter{&t.common}
+		if t.chatty != nil {
+			t.chatty.Updatef(t.name, "=== RUN   %s\n", t.name)
+		}
+		f.common.inFuzzFn, f.inFuzzFn = true, true
+		go tRunner(t, func(t *T) {
+			args := []reflect.Value{reflect.ValueOf(t)}
+			for _, v := range e.Values {
+				args = append(args, reflect.ValueOf(v))
+			}
+			// Before resetting the current coverage, defer the snapshot so that
+			// we make sure it is called right before the tRunner function
+			// exits, regardless of whether it was executed cleanly, panicked,
+			// or if the fuzzFn called t.Fatal.
+			if f.testContext.isFuzzing {
+				defer f.fuzzContext.deps.SnapshotCoverage()
+				f.fuzzContext.deps.ResetCoverage()
+			}
+			fn.Call(args)
+		})
+		<-t.signal
+		if t.chatty != nil && t.chatty.json {
+			t.chatty.Updatef(t.parent.name, "=== NAME  %s\n", t.parent.name)
+		}
+		f.common.inFuzzFn, f.inFuzzFn = false, false
+		return !t.Failed()
+	}
+
+	switch f.fuzzContext.mode {
+	case fuzzCoordinator:
+		// Fuzzing is enabled, and this is the test process started by 'go test'.
+		// Act as the coordinator process, and coordinate workers to perform the
+		// actual fuzzing.
+		corpusTargetDir := filepath.Join(corpusDir, f.name)
+		cacheTargetDir := filepath.Join(*fuzzCacheDir, f.name)
+		err := f.fuzzContext.deps.CoordinateFuzzing(
+			fuzzDuration.d,
+			int64(fuzzDuration.n),
+			minimizeDuration.d,
+			int64(minimizeDuration.n),
+			*parallel,
+			f.corpus,
+			types,
+			corpusTargetDir,
+			cacheTargetDir)
+		if err != nil {
+			f.result = fuzzResult{Error: err}
+			f.Fail()
+			fmt.Fprintf(f.w, "%v\n", err)
+			if crashErr, ok := err.(fuzzCrashError); ok {
+				crashPath := crashErr.CrashPath()
+				fmt.Fprintf(f.w, "Failing input written to %s\n", crashPath)
+				testName := filepath.Base(crashPath)
+				fmt.Fprintf(f.w, "To re-run:\ngo test -run=%s/%s\n", f.name, testName)
+			}
+		}
+		// TODO(jayconrod,katiehockman): Aggregate statistics across workers
+		// and add to FuzzResult (ie. time taken, num iterations)
+
+	case fuzzWorker:
+		// Fuzzing is enabled, and this is a worker process. Follow instructions
+		// from the coordinator.
+		if err := f.fuzzContext.deps.RunFuzzWorker(func(e corpusEntry) error {
+			// Don't write to f.w (which points to Stdout) if running from a
+			// fuzz worker. This would become very verbose, particularly during
+			// minimization. Return the error instead, and let the caller deal
+			// with the output.
+			var buf strings.Builder
+			if ok := run(&buf, e); !ok {
+				return errors.New(buf.String())
+			}
+			return nil
+		}); err != nil {
+			// Internal errors are marked with f.Fail; user code may call this too, before F.Fuzz.
+			// The worker will exit with fuzzWorkerExitCode, indicating this is a failure
+			// (and 'go test' should exit non-zero) but a failing input should not be recorded.
+			f.Errorf("communicating with fuzzing coordinator: %v", err)
+		}
+
+	default:
+		// Fuzzing is not enabled, or will be done later. Only run the seed
+		// corpus now.
+		for _, e := range f.corpus {
+			name := fmt.Sprintf("%s/%s", f.name, filepath.Base(e.Path))
+			if _, ok, _ := f.testContext.match.fullName(nil, name); ok {
+				run(f.w, e)
+			}
+		}
+	}
+}
+
+func (f *F) report() {
+	if *isFuzzWorker || f.parent == nil {
+		return
+	}
+	dstr := fmtDuration(f.duration)
+	format := "--- %s: %s (%s)\n"
+	if f.Failed() {
+		f.flushToParent(f.name, format, "FAIL", f.name, dstr)
+	} else if f.chatty != nil {
+		if f.Skipped() {
+			f.flushToParent(f.name, format, "SKIP", f.name, dstr)
+		} else {
+			f.flushToParent(f.name, format, "PASS", f.name, dstr)
+		}
+	}
+}
+
+// fuzzResult contains the results of a fuzz run.
+type fuzzResult struct {
+	N     int           // The number of iterations.
+	T     time.Duration // The total time taken.
+	Error error         // Error is the error from the failing input
+}
+
+func (r fuzzResult) String() string {
+	if r.Error == nil {
+		return ""
+	}
+	return r.Error.Error()
+}
+
+// fuzzCrashError is satisfied by a failing input detected while fuzzing.
+// These errors are written to the seed corpus and can be re-run with 'go test'.
+// Errors within the fuzzing framework (like I/O errors between coordinator
+// and worker processes) don't satisfy this interface.
+type fuzzCrashError interface {
+	error
+	Unwrap() error
+
+	// CrashPath returns the path of the subtest that corresponds to the saved
+	// crash input file in the seed corpus. The test can be re-run with go test
+	// -run=$test/$name $test is the fuzz test name, and $name is the
+	// filepath.Base of the string returned here.
+	CrashPath() string
+}
+
+// fuzzContext holds fields common to all fuzz tests.
+type fuzzContext struct {
+	deps testDeps
+	mode fuzzMode
+}
+
+type fuzzMode uint8
+
+const (
+	seedCorpusOnly fuzzMode = iota
+	fuzzCoordinator
+	fuzzWorker
+)
+
+// runFuzzTests runs the fuzz tests matching the pattern for -run. This will
+// only run the (*F).Fuzz function for each seed corpus without using the
+// fuzzing engine to generate or mutate inputs.
+func runFuzzTests(deps testDeps, fuzzTests []InternalFuzzTarget, deadline time.Time) (ran, ok bool) {
+	ok = true
+	if len(fuzzTests) == 0 || *isFuzzWorker {
+		return ran, ok
+	}
+	m := newMatcher(deps.MatchString, *match, "-test.run", *skip)
+	var mFuzz *matcher
+	if *matchFuzz != "" {
+		mFuzz = newMatcher(deps.MatchString, *matchFuzz, "-test.fuzz", *skip)
+	}
+
+	for _, procs := range cpuList {
+		runtime.GOMAXPROCS(procs)
+		for i := uint(0); i < *count; i++ {
+			if shouldFailFast() {
+				break
+			}
+
+			tctx := newTestContext(*parallel, m)
+			tctx.deadline = deadline
+			fctx := &fuzzContext{deps: deps, mode: seedCorpusOnly}
+			root := common{w: os.Stdout} // gather output in one place
+			if Verbose() {
+				root.chatty = newChattyPrinter(root.w)
+			}
+			for _, ft := range fuzzTests {
+				if shouldFailFast() {
+					break
+				}
+				testName, matched, _ := tctx.match.fullName(nil, ft.Name)
+				if !matched {
+					continue
+				}
+				if mFuzz != nil {
+					if _, fuzzMatched, _ := mFuzz.fullName(nil, ft.Name); fuzzMatched {
+						// If this will be fuzzed, then don't run the seed corpus
+						// right now. That will happen later.
+						continue
+					}
+				}
+				f := &F{
+					common: common{
+						signal:  make(chan bool),
+						barrier: make(chan bool),
+						name:    testName,
+						parent:  &root,
+						level:   root.level + 1,
+						chatty:  root.chatty,
+					},
+					testContext: tctx,
+					fuzzContext: fctx,
+				}
+				f.w = indenter{&f.common}
+				if f.chatty != nil {
+					f.chatty.Updatef(f.name, "=== RUN   %s\n", f.name)
+				}
+				go fRunner(f, ft.Fn)
+				<-f.signal
+				if f.chatty != nil && f.chatty.json {
+					f.chatty.Updatef(f.parent.name, "=== NAME  %s\n", f.parent.name)
+				}
+				ok = ok && !f.Failed()
+				ran = ran || f.ran
+			}
+			if !ran {
+				// There were no tests to run on this iteration.
+				// This won't change, so no reason to keep trying.
+				break
+			}
+		}
+	}
+
+	return ran, ok
+}
+
+// runFuzzing runs the fuzz test matching the pattern for -fuzz. Only one such
+// fuzz test must match. This will run the fuzzing engine to generate and
+// mutate new inputs against the fuzz target.
+//
+// If fuzzing is disabled (-test.fuzz is not set), runFuzzing
+// returns immediately.
+func runFuzzing(deps testDeps, fuzzTests []InternalFuzzTarget) (ok bool) {
+	if len(fuzzTests) == 0 || *matchFuzz == "" {
+		return true
+	}
+	m := newMatcher(deps.MatchString, *matchFuzz, "-test.fuzz", *skip)
+	tctx := newTestContext(1, m)
+	tctx.isFuzzing = true
+	fctx := &fuzzContext{
+		deps: deps,
+	}
+	root := common{w: os.Stdout}
+	if *isFuzzWorker {
+		root.w = io.Discard
+		fctx.mode = fuzzWorker
+	} else {
+		fctx.mode = fuzzCoordinator
+	}
+	if Verbose() && !*isFuzzWorker {
+		root.chatty = newChattyPrinter(root.w)
+	}
+	var fuzzTest *InternalFuzzTarget
+	var testName string
+	var matched []string
+	for i := range fuzzTests {
+		name, ok, _ := tctx.match.fullName(nil, fuzzTests[i].Name)
+		if !ok {
+			continue
+		}
+		matched = append(matched, name)
+		fuzzTest = &fuzzTests[i]
+		testName = name
+	}
+	if len(matched) == 0 {
+		fmt.Fprintln(os.Stderr, "testing: warning: no fuzz tests to fuzz")
+		return true
+	}
+	if len(matched) > 1 {
+		fmt.Fprintf(os.Stderr, "testing: will not fuzz, -fuzz matches more than one fuzz test: %v\n", matched)
+		return false
+	}
+
+	f := &F{
+		common: common{
+			signal:  make(chan bool),
+			barrier: nil, // T.Parallel has no effect when fuzzing.
+			name:    testName,
+			parent:  &root,
+			level:   root.level + 1,
+			chatty:  root.chatty,
+		},
+		fuzzContext: fctx,
+		testContext: tctx,
+	}
+	f.w = indenter{&f.common}
+	if f.chatty != nil {
+		f.chatty.Updatef(f.name, "=== RUN   %s\n", f.name)
+	}
+	go fRunner(f, fuzzTest.Fn)
+	<-f.signal
+	if f.chatty != nil {
+		f.chatty.Updatef(f.parent.name, "=== NAME  %s\n", f.parent.name)
+	}
+	return !f.failed
+}
+
+// fRunner wraps a call to a fuzz test and ensures that cleanup functions are
+// called and status flags are set. fRunner should be called in its own
+// goroutine. To wait for its completion, receive from f.signal.
+//
+// fRunner is analogous to tRunner, which wraps subtests started with T.Run.
+// Unit tests and fuzz tests work a little differently, so for now, these
+// functions aren't consolidated. In particular, because there are no F.Run and
+// F.Parallel methods, i.e., no fuzz sub-tests or parallel fuzz tests, a few
+// simplifications are made. We also require that F.Fuzz, F.Skip, or F.Fail is
+// called.
+func fRunner(f *F, fn func(*F)) {
+	// When this goroutine is done, either because runtime.Goexit was called, a
+	// panic started, or fn returned normally, record the duration and send
+	// t.signal, indicating the fuzz test is done.
+	defer func() {
+		// Detect whether the fuzz test panicked or called runtime.Goexit
+		// without calling F.Fuzz, F.Fail, or F.Skip. If it did, panic (possibly
+		// replacing a nil panic value). Nothing should recover after fRunner
+		// unwinds, so this should crash the process and print stack.
+		// Unfortunately, recovering here adds stack frames, but the location of
+		// the original panic should still be
+		// clear.
+		if f.Failed() {
+			numFailed.Add(1)
+		}
+		err := recover()
+		if err == nil {
+			f.mu.RLock()
+			fuzzNotCalled := !f.fuzzCalled && !f.skipped && !f.failed
+			if !f.finished && !f.skipped && !f.failed {
+				err = errNilPanicOrGoexit
+			}
+			f.mu.RUnlock()
+			if fuzzNotCalled && err == nil {
+				f.Error("returned without calling F.Fuzz, F.Fail, or F.Skip")
+			}
+		}
+
+		// Use a deferred call to ensure that we report that the test is
+		// complete even if a cleanup function calls F.FailNow. See issue 41355.
+		didPanic := false
+		defer func() {
+			if !didPanic {
+				// Only report that the test is complete if it doesn't panic,
+				// as otherwise the test binary can exit before the panic is
+				// reported to the user. See issue 41479.
+				f.signal <- true
+			}
+		}()
+
+		// If we recovered a panic or inappropriate runtime.Goexit, fail the test,
+		// flush the output log up to the root, then panic.
+		doPanic := func(err any) {
+			f.Fail()
+			if r := f.runCleanup(recoverAndReturnPanic); r != nil {
+				f.Logf("cleanup panicked with %v", r)
+			}
+			for root := &f.common; root.parent != nil; root = root.parent {
+				root.mu.Lock()
+				root.duration += time.Since(root.start)
+				d := root.duration
+				root.mu.Unlock()
+				root.flushToParent(root.name, "--- FAIL: %s (%s)\n", root.name, fmtDuration(d))
+			}
+			didPanic = true
+			panic(err)
+		}
+		if err != nil {
+			doPanic(err)
+		}
+
+		// No panic or inappropriate Goexit.
+		f.duration += time.Since(f.start)
+
+		if len(f.sub) > 0 {
+			// Unblock inputs that called T.Parallel while running the seed corpus.
+			// This only affects fuzz tests run as normal tests.
+			// While fuzzing, T.Parallel has no effect, so f.sub is empty, and this
+			// branch is not taken. f.barrier is nil in that case.
+			f.testContext.release()
+			close(f.barrier)
+			// Wait for the subtests to complete.
+			for _, sub := range f.sub {
+				<-sub.signal
+			}
+			cleanupStart := time.Now()
+			err := f.runCleanup(recoverAndReturnPanic)
+			f.duration += time.Since(cleanupStart)
+			if err != nil {
+				doPanic(err)
+			}
+		}
+
+		// Report after all subtests have finished.
+		f.report()
+		f.done = true
+		f.setRan()
+	}()
+	defer func() {
+		if len(f.sub) == 0 {
+			f.runCleanup(normalPanic)
+		}
+	}()
+
+	f.start = time.Now()
+	fn(f)
+
+	// Code beyond this point will not be executed when FailNow or SkipNow
+	// is invoked.
+	f.mu.Lock()
+	f.finished = true
+	f.mu.Unlock()
+}