return dst
}

// MatchStack assigns the current call stack a change ID.
// If the stack should be printed, MatchStack prints it.
// Then MatchStack reports whether a change at the current call stack should be enabled.
func (m *Matcher) Stack(w Writer) bool {
	if m == nil {
		return true
	}
	return m.stack(w)
}

// stack does the real work for Stack.
// This lets stack's body handle m == nil and potentially be inlined.

	parentTID  uint64 // Where to store child TID, in parent's memory (pid_t *)
	exitSignal uint64 // Signal to deliver to parent on child termination
	stack      uint64 // Pointer to lowest byte of stack
	stackSize  uint64 // Size of stack
	tls        uint64 // Location of new TLS
	setTID     uint64 // Pointer to a pid_t array (since Linux 5.5)
	setTIDSize uint64 // Number of elements in set_tid (since Linux 5.5)

	for _, l := range locs {
		stack, err := obj.SourceLine(l.Address)
		if err != nil || len(stack) == 0 {
			// No answers from addr2line.
			continue
		}

		l.Line = make([]profile.Line, len(stack))
		l.IsFolded = false
		for i, frame := range stack {
			if frame.Func != "" {
				m.HasFunctions = true
			}
			if frame.File != "" {

// as a span.
//
// Must be in a non-preemptible state to ensure the consistency of statistics
// exported to MemStats.
//
// Acquires the heap lock. Must run on the system stack for that reason.
//
//go:systemstack
func (h *mheap) allocUserArenaChunk() *mspan {
	var s *mspan
	var base uintptr

	// First check the free list.
	lock(&h.lock)

			ctx.Slice(traceviewer.SliceEvent{
				Name:     r.Name,
				Ts:       ctx.elapsed(ar.time),
				Dur:      ev.Time().Sub(ar.time),
				Resource: trace.GCP,
				Stack:    ctx.Stack(viewerFrames(ar.stack)),
				EndStack: ctx.Stack(viewerFrames(ev.Stack())),
			})
		}
		delete(g.ranges, r.Name)
	}
}

// Finish flushes any outstanding ranges at the end of the trace.

			}

			if !p.From.Sym.NoFrame() {
				// If there is a stack frame at all, it includes
				// space to save the LR.
				autosize += int32(c.ctxt.Arch.FixedFrameSize)
			}

			if p.Mark&LEAF != 0 && autosize < abi.StackSmall {
				// A leaf function with a small stack can be marked
				// NOSPLIT, avoiding a stack check.
				p.From.Sym.Set(obj.AttrNoSplit, true)
			}

	// stackPtrs is a bitmap that indicates whether
	// each word in the ABI stack space (stack-assigned
	// args + return values) is a pointer. Used
	// as the heap pointer bitmap for stack space
	// passed to reflectcall.
	stackPtrs *bitVector

	// inRegPtrs is a bitmap whose i'th bit indicates
	// whether the i'th integer argument register contains
	// a pointer. Used by makeFuncStub and methodValueCall

//
//	goroutine    - stack traces of all current goroutines
//	heap         - a sampling of memory allocations of live objects
//	allocs       - a sampling of all past memory allocations
//	threadcreate - stack traces that led to the creation of new OS threads
//	block        - stack traces that led to blocking on synchronization primitives
//	mutex        - stack traces of holders of contended mutexes
//

	return nil
}

// validateStackStrings makes sure all the string references in
// the stack table are present in the string table.
func validateStackStrings(
	stacks *dataTable[stackID, stack],
	strings *dataTable[stringID, string],
	frames map[uint64]frame,
) error {
	var err error
	stacks.forEach(func(id stackID, stk stack) bool {
		for _, pc := range stk.pcs {
			frame, ok := frames[pc]
			if !ok {

		Type:  r.Name,
	}
}

func regionTopStackFrame(r *trace.UserRegionSummary) trace.StackFrame {
	var frame trace.StackFrame
	if r.Start != nil && r.Start.Stack() != trace.NoStack {
		r.Start.Stack().Frames(func(f trace.StackFrame) bool {
			frame = f
			return false
		})
	}
	return frame
}

type regionStats struct {
	regionFingerprint
	Histogram traceviewer.TimeHistogram
}