return sehf4(pan)
}

//go:noinline
func sehf4(pan bool) []uintptr {
	var pcs []uintptr
	if pan {
		panic("sehf4")
	}
	pcs = sehCallers()
	return pcs
}

func testSehCallersEqual(t *testing.T, pcs []uintptr, want []string) {
	t.Helper()
	got := make([]string, 0, len(want))
	for _, pc := range pcs {
		fn := runtime.FuncForPC(pc)
		if fn == nil || len(got) >= len(want) {
			break
		}

		"runtime_test.TestCallersPanic"}

	defer func() {
		if r := recover(); r == nil {
			t.Fatal("did not panic")
		}
		pcs := make([]uintptr, 20)
		pcs = pcs[:runtime.Callers(0, pcs)]
		testCallers(t, pcs, true)
		testCallersEqual(t, pcs, want)
	}()
	f1(true)
}

func TestCallersDoublePanic(t *testing.T) {
	// Make sure we don't have any extra frames on the stack (due to

// creating it if necessary.
func (c *StackCounter) Inc() {
	pcs := make([]uintptr, c.depth)
	n := runtime.Callers(2, pcs) // caller of Inc
	pcs = pcs[:n]

	c.mu.Lock()
	defer c.mu.Unlock()

	// Existing counter?
	var ctr *Counter
	for _, s := range c.stacks {
		if eq(s.pcs, pcs) {
			if s.counter != nil {
				ctr = s.counter
				break
			}
		}
	}

	if ctr == nil {

		return rec
	}
	// Slow path: the stack may still be in the map.

	// Grab the stack's PCs as the source-of-truth.
	var pcs [pprofMaxStack]uint64
	pcsForStack(stack, &pcs)

	// Check the source-of-truth.
	var rec *traceviewer.ProfileRecord
	if existing, ok := m.pcs[pcs]; ok {
		// In the map.
		rec = m.stacks[existing]
		delete(m.stacks, existing)
	} else {
		// Not in the map.

}

type locInfo struct {
	// location id assigned by the profileBuilder
	id uint64

	// sequence of PCs, including the fake PCs returned by the traceback
	// to represent inlined functions
	// https://github.com/golang/go/blob/d6f2f833c93a41ec1c68e49804b8387a06b131c5/src/runtime/traceback.go#L347-L368
	pcs []uintptr

	// firstPCFrames and firstPCSymbolizeResult hold the results of the

// walkFrames calls visit for each call frame represented by pcs.
//
// pcs should be a slice of PCs, as returned by runtime.Callers.
func walkFrames(pcs []uintptr, visit frameVisitor) {
	if len(pcs) == 0 {
		return
	}

	frames := runtime.CallersFrames(pcs)
	for {
		frame, more := frames.Next()
		visit(frame.File, frame.Line, frame.Function, frame.PC-frame.Entry)

type traceStackTable struct {
	tab traceMap
}

// put returns a unique id for the stack trace pcs and caches it in the table,
// if it sees the trace for the first time.
func (t *traceStackTable) put(pcs []uintptr) uint64 {
	if len(pcs) == 0 {
		return 0
	}
	id, _ := t.tab.put(noescape(unsafe.Pointer(&pcs[0])), uintptr(len(pcs))*unsafe.Sizeof(uintptr(0)))
	return id
}

func Infof(logger *slog.Logger, format string, args ...any) {
	if !logger.Enabled(context.Background(), slog.LevelInfo) {
		return
	}
	var pcs [1]uintptr
	runtime.Callers(2, pcs[:]) // skip [Callers, Infof]
	r := slog.NewRecord(time.Now(), slog.LevelInfo, fmt.Sprintf(format, args...), pcs[0])
	_ = logger.Handler().Handle(context.Background(), r)
}

func Example_wrapping() {
	replace := func(groups []string, a slog.Attr) slog.Attr {

//go:noinline
func child7bad() {
}

//go:noinline
func child7() {
	// Write runtime.Caller's view of the stack to stderr, for debugging.
	var pcs [16]uintptr
	n := runtime.Callers(1, pcs[:])
	fmt.Fprintf(os.Stderr, "Callers: %#x\n", pcs[:n])
	io.WriteString(os.Stderr, formatStack(pcs[:n]))

	// Cause the crash report to be written to stdout.
	panic("oops")
}

// TestTracebackSystem tests that the syntax of crash reports produced

// and returns this as the name of a counter.
func telemetryCounterName(crash []byte) (string, error) {
	pcs, err := parseStackPCs(string(crash))
	if err != nil {
		return "", err
	}

	// Limit the number of frames we request.
	pcs = pcs[:min(len(pcs), 16)]

	if len(pcs) == 0 {
		// This can occur if all goroutines are idle, as when
		// caught in a deadlock, or killed by an async signal