1 //===-- StackFrameList.cpp --------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Target/StackFrameList.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Core/StreamFile.h"
17 #include "lldb/Core/SourceManager.h"
18 #include "lldb/Symbol/Block.h"
19 #include "lldb/Symbol/Function.h"
20 #include "lldb/Symbol/Symbol.h"
21 #include "lldb/Target/Process.h"
22 #include "lldb/Target/RegisterContext.h"
23 #include "lldb/Target/StackFrame.h"
24 #include "lldb/Target/StopInfo.h"
25 #include "lldb/Target/Target.h"
26 #include "lldb/Target/Thread.h"
27 #include "lldb/Target/Unwind.h"
28 
29 //#define DEBUG_STACK_FRAMES 1
30 
31 using namespace lldb;
32 using namespace lldb_private;
33 
34 //----------------------------------------------------------------------
35 // StackFrameList constructor
36 //----------------------------------------------------------------------
37 StackFrameList::StackFrameList
38 (
39     Thread &thread,
40     const lldb::StackFrameListSP &prev_frames_sp,
41     bool show_inline_frames
42 ) :
43     m_thread (thread),
44     m_prev_frames_sp (prev_frames_sp),
45     m_mutex (Mutex::eMutexTypeRecursive),
46     m_frames (),
47     m_selected_frame_idx (0),
48     m_concrete_frames_fetched (0),
49     m_current_inlined_depth (UINT32_MAX),
50     m_current_inlined_pc (LLDB_INVALID_ADDRESS),
51     m_show_inlined_frames (show_inline_frames)
52 {
53     if (prev_frames_sp)
54     {
55         m_current_inlined_depth = prev_frames_sp->m_current_inlined_depth;
56         m_current_inlined_pc =    prev_frames_sp->m_current_inlined_pc;
57     }
58 }
59 
60 //----------------------------------------------------------------------
61 // Destructor
62 //----------------------------------------------------------------------
63 StackFrameList::~StackFrameList()
64 {
65 }
66 
67 void
68 StackFrameList::CalculateCurrentInlinedDepth()
69 {
70     uint32_t cur_inlined_depth = GetCurrentInlinedDepth();
71     if (cur_inlined_depth == UINT32_MAX)
72     {
73         ResetCurrentInlinedDepth();
74     }
75 }
76 
77 uint32_t
78 StackFrameList::GetCurrentInlinedDepth ()
79 {
80     if (m_show_inlined_frames)
81     {
82         lldb::addr_t cur_pc = m_thread.GetRegisterContext()->GetPC();
83         if (cur_pc != m_current_inlined_pc)
84         {
85             m_current_inlined_pc = LLDB_INVALID_ADDRESS;
86             m_current_inlined_depth = UINT32_MAX;
87         }
88         return m_current_inlined_depth;
89     }
90     else
91     {
92         return UINT32_MAX;
93     }
94 }
95 
96 static const bool LLDB_FANCY_INLINED_STEPPING = false;
97 
98 void
99 StackFrameList::ResetCurrentInlinedDepth ()
100 {
101     if (LLDB_FANCY_INLINED_STEPPING && m_show_inlined_frames)
102     {
103         GetFramesUpTo(0);
104         if (!m_frames[0]->IsInlined())
105         {
106             m_current_inlined_depth = UINT32_MAX;
107             m_current_inlined_pc = LLDB_INVALID_ADDRESS;
108         }
109         else
110         {
111             // We only need to do something special about inlined blocks when we
112             // are at the beginning of an inlined function:
113             // FIXME: We probably also have to do something special if the PC is at the END
114             // of an inlined function, which coincides with the end of either its containing
115             // function or another inlined function.
116 
117             lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
118             Block *block_ptr = m_frames[0]->GetFrameBlock();
119             if (block_ptr)
120             {
121                 Address pc_as_address;
122                 pc_as_address.SetLoadAddress(curr_pc, &(m_thread.GetProcess()->GetTarget()));
123                 AddressRange containing_range;
124                 if (block_ptr->GetRangeContainingAddress(pc_as_address, containing_range))
125                 {
126                     if (pc_as_address == containing_range.GetBaseAddress())
127                     {
128                         // If we got here because of a breakpoint hit, then set the inlined depth depending on where
129                         // the breakpoint was set.
130                         // If we got here because of a crash, then set the inlined depth to the deepest most block.
131                         // Otherwise, we stopped here naturally as the result of a step, so set ourselves in the
132                         // containing frame of the whole set of nested inlines, so the user can then "virtually"
133                         // step into the frames one by one, or next over the whole mess.
134                         // Note: We don't have to handle being somewhere in the middle of the stack here, since
135                         // ResetCurrentInlinedDepth doesn't get called if there is a valid inlined depth set.
136                         StopInfoSP stop_info_sp = m_thread.GetStopInfo();
137                         if (stop_info_sp)
138                         {
139                             switch (stop_info_sp->GetStopReason())
140                             {
141                             case eStopReasonBreakpoint:
142                                 {
143 
144                                 }
145                                 break;
146                             case eStopReasonWatchpoint:
147                             case eStopReasonException:
148                             case eStopReasonSignal:
149                                 // In all these cases we want to stop in the deepest most frame.
150                                 m_current_inlined_pc = curr_pc;
151                                 m_current_inlined_depth = 0;
152                                 break;
153                             default:
154                                 {
155                                     // Otherwise, we should set ourselves at the container of the inlining, so that the
156                                     // user can descend into them.
157                                     // So first we check whether we have more than one inlined block sharing this PC:
158                                     int num_inlined_functions = 0;
159 
160                                     for  (Block *container_ptr = block_ptr->GetInlinedParent();
161                                               container_ptr != NULL;
162                                               container_ptr = container_ptr->GetInlinedParent())
163                                     {
164                                         if (!container_ptr->GetRangeContainingAddress(pc_as_address, containing_range))
165                                             break;
166                                         if (pc_as_address != containing_range.GetBaseAddress())
167                                             break;
168 
169                                         num_inlined_functions++;
170                                     }
171                                     m_current_inlined_pc = curr_pc;
172                                     m_current_inlined_depth = num_inlined_functions + 1;
173 
174                                 }
175                                 break;
176                             }
177                         }
178                     }
179                 }
180             }
181         }
182     }
183 }
184 
185 bool
186 StackFrameList::DecrementCurrentInlinedDepth ()
187 {
188     if (m_show_inlined_frames)
189     {
190         uint32_t current_inlined_depth = GetCurrentInlinedDepth();
191         if (current_inlined_depth != UINT32_MAX)
192         {
193             if (current_inlined_depth > 0)
194                 m_current_inlined_depth--;
195             return true;
196         }
197     }
198     return false;
199 }
200 
201 void
202 StackFrameList::GetFramesUpTo(uint32_t end_idx)
203 {
204     // We've already gotten more frames than asked for, or we've already finished unwinding, return.
205     if (m_frames.size() > end_idx || GetAllFramesFetched())
206         return;
207 
208     Unwind *unwinder = m_thread.GetUnwinder ();
209 
210     if (m_show_inlined_frames)
211     {
212 #if defined (DEBUG_STACK_FRAMES)
213         StreamFile s(stdout, false);
214 #endif
215         // If we are hiding some frames from the outside world, we need to add those onto the total count of
216         // frames to fetch.  However, we don't need ot do that if end_idx is 0 since in that case we always
217         // get the first concrete frame and all the inlined frames below it...
218 
219         uint32_t inlined_depth = 0;
220         if (end_idx > 0)
221         {
222             inlined_depth = GetCurrentInlinedDepth();
223             if (inlined_depth != UINT32_MAX)
224             {
225                 if (end_idx > 0)
226                     end_idx += inlined_depth;
227             }
228             else
229                 inlined_depth = 0;
230         }
231 
232         StackFrameSP unwind_frame_sp;
233         do
234         {
235             uint32_t idx = m_concrete_frames_fetched++;
236             lldb::addr_t pc;
237             lldb::addr_t cfa;
238             if (idx == 0)
239             {
240                 // We might have already created frame zero, only create it
241                 // if we need to
242                 if (m_frames.empty())
243                 {
244                     m_thread.GetRegisterContext();
245                     assert (m_thread.m_reg_context_sp.get());
246 
247                     const bool success = unwinder->GetFrameInfoAtIndex(idx, cfa, pc);
248                     // There shouldn't be any way not to get the frame info for frame 0.
249                     // But if the unwinder can't make one, lets make one by hand with the
250                     // SP as the CFA and see if that gets any further.
251                     if (!success)
252                     {
253                         cfa = m_thread.GetRegisterContext()->GetSP();
254                         pc = m_thread.GetRegisterContext()->GetPC();
255                     }
256 
257                     unwind_frame_sp.reset (new StackFrame (m_thread.shared_from_this(),
258                                                            m_frames.size(),
259                                                            idx,
260                                                            m_thread.m_reg_context_sp,
261                                                            cfa,
262                                                            pc,
263                                                            NULL));
264                     m_frames.push_back (unwind_frame_sp);
265                 }
266                 else
267                 {
268                     unwind_frame_sp = m_frames.front();
269                     cfa = unwind_frame_sp->m_id.GetCallFrameAddress();
270                 }
271             }
272             else
273             {
274                 const bool success = unwinder->GetFrameInfoAtIndex(idx, cfa, pc);
275                 if (!success)
276                 {
277                     // We've gotten to the end of the stack.
278                     SetAllFramesFetched();
279                     break;
280                 }
281                 unwind_frame_sp.reset (new StackFrame (m_thread.shared_from_this(), m_frames.size(), idx, cfa, pc, NULL));
282                 m_frames.push_back (unwind_frame_sp);
283             }
284 
285             SymbolContext unwind_sc = unwind_frame_sp->GetSymbolContext (eSymbolContextBlock | eSymbolContextFunction);
286             Block *unwind_block = unwind_sc.block;
287             if (unwind_block)
288             {
289                 Address curr_frame_address (unwind_frame_sp->GetFrameCodeAddress());
290                 // Be sure to adjust the frame address to match the address
291                 // that was used to lookup the symbol context above. If we are
292                 // in the first concrete frame, then we lookup using the current
293                 // address, else we decrement the address by one to get the correct
294                 // location.
295                 if (idx > 0)
296                     curr_frame_address.Slide(-1);
297 
298                 SymbolContext next_frame_sc;
299                 Address next_frame_address;
300 
301                 while (unwind_sc.GetParentOfInlinedScope(curr_frame_address, next_frame_sc, next_frame_address))
302                 {
303                         StackFrameSP frame_sp(new StackFrame (m_thread.shared_from_this(),
304                                                               m_frames.size(),
305                                                               idx,
306                                                               unwind_frame_sp->GetRegisterContextSP (),
307                                                               cfa,
308                                                               next_frame_address,
309                                                               &next_frame_sc));
310 
311                         m_frames.push_back (frame_sp);
312                         unwind_sc = next_frame_sc;
313                         curr_frame_address = next_frame_address;
314                 }
315             }
316         } while (m_frames.size() - 1 < end_idx);
317 
318         // Don't try to merge till you've calculated all the frames in this stack.
319         if (GetAllFramesFetched() && m_prev_frames_sp)
320         {
321             StackFrameList *prev_frames = m_prev_frames_sp.get();
322             StackFrameList *curr_frames = this;
323 
324 #if defined (DEBUG_STACK_FRAMES)
325             s.PutCString("\nprev_frames:\n");
326             prev_frames->Dump (&s);
327             s.PutCString("\ncurr_frames:\n");
328             curr_frames->Dump (&s);
329             s.EOL();
330 #endif
331             size_t curr_frame_num, prev_frame_num;
332 
333             for (curr_frame_num = curr_frames->m_frames.size(), prev_frame_num = prev_frames->m_frames.size();
334                  curr_frame_num > 0 && prev_frame_num > 0;
335                  --curr_frame_num, --prev_frame_num)
336             {
337                 const size_t curr_frame_idx = curr_frame_num-1;
338                 const size_t prev_frame_idx = prev_frame_num-1;
339                 StackFrameSP curr_frame_sp (curr_frames->m_frames[curr_frame_idx]);
340                 StackFrameSP prev_frame_sp (prev_frames->m_frames[prev_frame_idx]);
341 
342 #if defined (DEBUG_STACK_FRAMES)
343                 s.Printf("\n\nCurr frame #%u ", curr_frame_idx);
344                 if (curr_frame_sp)
345                     curr_frame_sp->Dump (&s, true, false);
346                 else
347                     s.PutCString("NULL");
348                 s.Printf("\nPrev frame #%u ", prev_frame_idx);
349                 if (prev_frame_sp)
350                     prev_frame_sp->Dump (&s, true, false);
351                 else
352                     s.PutCString("NULL");
353 #endif
354 
355                 StackFrame *curr_frame = curr_frame_sp.get();
356                 StackFrame *prev_frame = prev_frame_sp.get();
357 
358                 if (curr_frame == NULL || prev_frame == NULL)
359                     break;
360 
361                 // Check the stack ID to make sure they are equal
362                 if (curr_frame->GetStackID() != prev_frame->GetStackID())
363                     break;
364 
365                 prev_frame->UpdatePreviousFrameFromCurrentFrame (*curr_frame);
366                 // Now copy the fixed up previous frame into the current frames
367                 // so the pointer doesn't change
368                 m_frames[curr_frame_idx] = prev_frame_sp;
369                 //curr_frame->UpdateCurrentFrameFromPreviousFrame (*prev_frame);
370 
371 #if defined (DEBUG_STACK_FRAMES)
372                 s.Printf("\n    Copying previous frame to current frame");
373 #endif
374             }
375             // We are done with the old stack frame list, we can release it now
376             m_prev_frames_sp.reset();
377         }
378 
379 #if defined (DEBUG_STACK_FRAMES)
380             s.PutCString("\n\nNew frames:\n");
381             Dump (&s);
382             s.EOL();
383 #endif
384     }
385     else
386     {
387         if (end_idx < m_concrete_frames_fetched)
388             return;
389 
390         uint32_t num_frames = unwinder->GetFramesUpTo(end_idx);
391         if (num_frames <= end_idx + 1)
392         {
393             //Done unwinding.
394             m_concrete_frames_fetched = UINT32_MAX;
395         }
396         m_frames.resize(num_frames);
397     }
398 }
399 
400 uint32_t
401 StackFrameList::GetNumFrames (bool can_create)
402 {
403     Mutex::Locker locker (m_mutex);
404 
405     if (can_create)
406         GetFramesUpTo (UINT32_MAX);
407 
408     uint32_t inlined_depth = GetCurrentInlinedDepth();
409     if (inlined_depth == UINT32_MAX)
410         return m_frames.size();
411     else
412         return m_frames.size() - inlined_depth;
413 }
414 
415 void
416 StackFrameList::Dump (Stream *s)
417 {
418     if (s == NULL)
419         return;
420     Mutex::Locker locker (m_mutex);
421 
422     const_iterator pos, begin = m_frames.begin(), end = m_frames.end();
423     for (pos = begin; pos != end; ++pos)
424     {
425         StackFrame *frame = (*pos).get();
426         s->Printf("%p: ", frame);
427         if (frame)
428         {
429             frame->GetStackID().Dump (s);
430             frame->DumpUsingSettingsFormat (s);
431         }
432         else
433             s->Printf("frame #%u", (uint32_t)std::distance (begin, pos));
434         s->EOL();
435     }
436     s->EOL();
437 }
438 
439 StackFrameSP
440 StackFrameList::GetFrameAtIndex (uint32_t idx)
441 {
442     StackFrameSP frame_sp;
443     Mutex::Locker locker (m_mutex);
444     uint32_t inlined_depth = GetCurrentInlinedDepth();
445     if (inlined_depth != UINT32_MAX)
446         idx += inlined_depth;
447 
448     if (idx < m_frames.size())
449         frame_sp = m_frames[idx];
450 
451     if (frame_sp)
452         return frame_sp;
453 
454         // GetFramesUpTo will fill m_frames with as many frames as you asked for,
455         // if there are that many.  If there weren't then you asked for too many
456         // frames.
457         GetFramesUpTo (idx);
458         if (idx < m_frames.size())
459         {
460             if (m_show_inlined_frames)
461             {
462                 // When inline frames are enabled we actually create all the frames in GetFramesUpTo.
463                 frame_sp = m_frames[idx];
464             }
465             else
466             {
467                 Unwind *unwinder = m_thread.GetUnwinder ();
468                 if (unwinder)
469                 {
470                     addr_t pc, cfa;
471                     if (unwinder->GetFrameInfoAtIndex(idx, cfa, pc))
472                     {
473                         frame_sp.reset (new StackFrame (m_thread.shared_from_this(), idx, idx, cfa, pc, NULL));
474 
475                         Function *function = frame_sp->GetSymbolContext (eSymbolContextFunction).function;
476                         if (function)
477                         {
478                             // When we aren't showing inline functions we always use
479                             // the top most function block as the scope.
480                             frame_sp->SetSymbolContextScope (&function->GetBlock(false));
481                         }
482                         else
483                         {
484                             // Set the symbol scope from the symbol regardless if it is NULL or valid.
485                             frame_sp->SetSymbolContextScope (frame_sp->GetSymbolContext (eSymbolContextSymbol).symbol);
486                         }
487                         SetFrameAtIndex(idx, frame_sp);
488                     }
489                 }
490             }
491         }
492     return frame_sp;
493 }
494 
495 StackFrameSP
496 StackFrameList::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
497 {
498     // First try assuming the unwind index is the same as the frame index. The
499     // unwind index is always greater than or equal to the frame index, so it
500     // is a good place to start. If we have inlined frames we might have 5
501     // concrete frames (frame unwind indexes go from 0-4), but we might have 15
502     // frames after we make all the inlined frames. Most of the time the unwind
503     // frame index (or the concrete frame index) is the same as the frame index.
504     uint32_t frame_idx = unwind_idx;
505     StackFrameSP frame_sp (GetFrameAtIndex (frame_idx));
506     while (frame_sp)
507     {
508         if (frame_sp->GetFrameIndex() == unwind_idx)
509             break;
510         frame_sp = GetFrameAtIndex (++frame_idx);
511     }
512     return frame_sp;
513 }
514 
515 StackFrameSP
516 StackFrameList::GetFrameWithStackID (const StackID &stack_id)
517 {
518     uint32_t frame_idx = 0;
519     StackFrameSP frame_sp;
520     do
521     {
522         frame_sp = GetFrameAtIndex (frame_idx);
523         if (frame_sp && frame_sp->GetStackID() == stack_id)
524             break;
525         frame_idx++;
526     }
527     while (frame_sp);
528     return frame_sp;
529 }
530 
531 bool
532 StackFrameList::SetFrameAtIndex (uint32_t idx, StackFrameSP &frame_sp)
533 {
534     if (idx >= m_frames.size())
535         m_frames.resize(idx + 1);
536     // Make sure allocation succeeded by checking bounds again
537     if (idx < m_frames.size())
538     {
539         m_frames[idx] = frame_sp;
540         return true;
541     }
542     return false;   // resize failed, out of memory?
543 }
544 
545 uint32_t
546 StackFrameList::GetSelectedFrameIndex () const
547 {
548     Mutex::Locker locker (m_mutex);
549     return m_selected_frame_idx;
550 }
551 
552 
553 uint32_t
554 StackFrameList::SetSelectedFrame (lldb_private::StackFrame *frame)
555 {
556     Mutex::Locker locker (m_mutex);
557     const_iterator pos;
558     const_iterator begin = m_frames.begin();
559     const_iterator end = m_frames.end();
560     m_selected_frame_idx = 0;
561     for (pos = begin; pos != end; ++pos)
562     {
563         if (pos->get() == frame)
564         {
565             m_selected_frame_idx = std::distance (begin, pos);
566             uint32_t inlined_depth = GetCurrentInlinedDepth();
567             if (inlined_depth != UINT32_MAX)
568                 m_selected_frame_idx -= inlined_depth;
569             break;
570         }
571     }
572     SetDefaultFileAndLineToSelectedFrame();
573     return m_selected_frame_idx;
574 }
575 
576 // Mark a stack frame as the current frame using the frame index
577 bool
578 StackFrameList::SetSelectedFrameByIndex (uint32_t idx)
579 {
580     Mutex::Locker locker (m_mutex);
581     StackFrameSP frame_sp (GetFrameAtIndex (idx));
582     if (frame_sp)
583     {
584         SetSelectedFrame(frame_sp.get());
585         return true;
586     }
587     else
588         return false;
589 }
590 
591 void
592 StackFrameList::SetDefaultFileAndLineToSelectedFrame()
593 {
594     if (m_thread.GetID() == m_thread.GetProcess()->GetThreadList().GetSelectedThread()->GetID())
595     {
596         StackFrameSP frame_sp (GetFrameAtIndex (GetSelectedFrameIndex()));
597         if (frame_sp)
598         {
599             SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextLineEntry);
600             if (sc.line_entry.file)
601                 m_thread.CalculateTarget()->GetSourceManager().SetDefaultFileAndLine (sc.line_entry.file,
602                                                                                             sc.line_entry.line);
603         }
604     }
605 }
606 
607 // The thread has been run, reset the number stack frames to zero so we can
608 // determine how many frames we have lazily.
609 void
610 StackFrameList::Clear ()
611 {
612     Mutex::Locker locker (m_mutex);
613     m_frames.clear();
614     m_concrete_frames_fetched = 0;
615 }
616 
617 void
618 StackFrameList::InvalidateFrames (uint32_t start_idx)
619 {
620     Mutex::Locker locker (m_mutex);
621     if (m_show_inlined_frames)
622     {
623         Clear();
624     }
625     else
626     {
627         const size_t num_frames = m_frames.size();
628         while (start_idx < num_frames)
629         {
630             m_frames[start_idx].reset();
631             ++start_idx;
632         }
633     }
634 }
635 
636 void
637 StackFrameList::Merge (std::auto_ptr<StackFrameList>& curr_ap, lldb::StackFrameListSP& prev_sp)
638 {
639     Mutex::Locker curr_locker (curr_ap.get() ? &curr_ap->m_mutex : NULL);
640     Mutex::Locker prev_locker (prev_sp.get() ? &prev_sp->m_mutex : NULL);
641 
642 #if defined (DEBUG_STACK_FRAMES)
643     StreamFile s(stdout, false);
644     s.PutCString("\n\nStackFrameList::Merge():\nPrev:\n");
645     if (prev_sp.get())
646         prev_sp->Dump (&s);
647     else
648         s.PutCString ("NULL");
649     s.PutCString("\nCurr:\n");
650     if (curr_ap.get())
651         curr_ap->Dump (&s);
652     else
653         s.PutCString ("NULL");
654     s.EOL();
655 #endif
656 
657     if (curr_ap.get() == NULL || curr_ap->GetNumFrames (false) == 0)
658     {
659 #if defined (DEBUG_STACK_FRAMES)
660         s.PutCString("No current frames, leave previous frames alone...\n");
661 #endif
662         curr_ap.release();
663         return;
664     }
665 
666     if (prev_sp.get() == NULL || prev_sp->GetNumFrames (false) == 0)
667     {
668 #if defined (DEBUG_STACK_FRAMES)
669         s.PutCString("No previous frames, so use current frames...\n");
670 #endif
671         // We either don't have any previous frames, or since we have more than
672         // one current frames it means we have all the frames and can safely
673         // replace our previous frames.
674         prev_sp.reset (curr_ap.release());
675         return;
676     }
677 
678     const uint32_t num_curr_frames = curr_ap->GetNumFrames (false);
679 
680     if (num_curr_frames > 1)
681     {
682 #if defined (DEBUG_STACK_FRAMES)
683         s.PutCString("We have more than one current frame, so use current frames...\n");
684 #endif
685         // We have more than one current frames it means we have all the frames
686         // and can safely replace our previous frames.
687         prev_sp.reset (curr_ap.release());
688 
689 #if defined (DEBUG_STACK_FRAMES)
690         s.PutCString("\nMerged:\n");
691         prev_sp->Dump (&s);
692 #endif
693         return;
694     }
695 
696     StackFrameSP prev_frame_zero_sp(prev_sp->GetFrameAtIndex (0));
697     StackFrameSP curr_frame_zero_sp(curr_ap->GetFrameAtIndex (0));
698     StackID curr_stack_id (curr_frame_zero_sp->GetStackID());
699     StackID prev_stack_id (prev_frame_zero_sp->GetStackID());
700 
701 #if defined (DEBUG_STACK_FRAMES)
702     const uint32_t num_prev_frames = prev_sp->GetNumFrames (false);
703     s.Printf("\n%u previous frames with one current frame\n", num_prev_frames);
704 #endif
705 
706     // We have only a single current frame
707     // Our previous stack frames only had a single frame as well...
708     if (curr_stack_id == prev_stack_id)
709     {
710 #if defined (DEBUG_STACK_FRAMES)
711         s.Printf("\nPrevious frame #0 is same as current frame #0, merge the cached data\n");
712 #endif
713 
714         curr_frame_zero_sp->UpdateCurrentFrameFromPreviousFrame (*prev_frame_zero_sp);
715 //        prev_frame_zero_sp->UpdatePreviousFrameFromCurrentFrame (*curr_frame_zero_sp);
716 //        prev_sp->SetFrameAtIndex (0, prev_frame_zero_sp);
717     }
718     else if (curr_stack_id < prev_stack_id)
719     {
720 #if defined (DEBUG_STACK_FRAMES)
721         s.Printf("\nCurrent frame #0 has a stack ID that is less than the previous frame #0, insert current frame zero in front of previous\n");
722 #endif
723         prev_sp->m_frames.insert (prev_sp->m_frames.begin(), curr_frame_zero_sp);
724     }
725 
726     curr_ap.release();
727 
728 #if defined (DEBUG_STACK_FRAMES)
729     s.PutCString("\nMerged:\n");
730     prev_sp->Dump (&s);
731 #endif
732 
733 
734 }
735 
736 lldb::StackFrameSP
737 StackFrameList::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
738 {
739     const_iterator pos;
740     const_iterator begin = m_frames.begin();
741     const_iterator end = m_frames.end();
742     lldb::StackFrameSP ret_sp;
743 
744     for (pos = begin; pos != end; ++pos)
745     {
746         if (pos->get() == stack_frame_ptr)
747         {
748             ret_sp = (*pos);
749             break;
750         }
751     }
752     return ret_sp;
753 }
754 
755 size_t
756 StackFrameList::GetStatus (Stream& strm,
757                            uint32_t first_frame,
758                            uint32_t num_frames,
759                            bool show_frame_info,
760                            uint32_t num_frames_with_source)
761 {
762     size_t num_frames_displayed = 0;
763 
764     if (num_frames == 0)
765         return 0;
766 
767     StackFrameSP frame_sp;
768     uint32_t frame_idx = 0;
769     uint32_t last_frame;
770 
771     // Don't let the last frame wrap around...
772     if (num_frames == UINT32_MAX)
773         last_frame = UINT32_MAX;
774     else
775         last_frame = first_frame + num_frames;
776 
777     for (frame_idx = first_frame; frame_idx < last_frame; ++frame_idx)
778     {
779         frame_sp = GetFrameAtIndex(frame_idx);
780         if (frame_sp.get() == NULL)
781             break;
782 
783         if (!frame_sp->GetStatus (strm,
784                                   show_frame_info,
785                                   num_frames_with_source > (first_frame - frame_idx)))
786             break;
787         ++num_frames_displayed;
788     }
789 
790     strm.IndentLess();
791     return num_frames_displayed;
792 }
793 
794