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/Target.h"
25 #include "lldb/Target/Thread.h"
26 #include "lldb/Target/Unwind.h"
27 
28 //#define DEBUG_STACK_FRAMES 1
29 
30 using namespace lldb;
31 using namespace lldb_private;
32 
33 //----------------------------------------------------------------------
34 // StackFrameList constructor
35 //----------------------------------------------------------------------
36 StackFrameList::StackFrameList
37 (
38     Thread &thread,
39     const lldb::StackFrameListSP &prev_frames_sp,
40     bool show_inline_frames
41 ) :
42     m_thread (thread),
43     m_prev_frames_sp (prev_frames_sp),
44     m_mutex (Mutex::eMutexTypeRecursive),
45     m_frames (),
46     m_selected_frame_idx (0),
47     m_concrete_frames_fetched (0),
48     m_show_inlined_frames (show_inline_frames)
49 {
50 }
51 
52 //----------------------------------------------------------------------
53 // Destructor
54 //----------------------------------------------------------------------
55 StackFrameList::~StackFrameList()
56 {
57 }
58 
59 void
60 StackFrameList::GetFramesUpTo(uint32_t end_idx)
61 {
62     // We've already gotten more frames than asked for, or we've already finished unwinding, return.
63     if (m_frames.size() > end_idx || GetAllFramesFetched())
64         return;
65 
66     Unwind *unwinder = m_thread.GetUnwinder ();
67 
68     if (m_show_inlined_frames)
69     {
70 #if defined (DEBUG_STACK_FRAMES)
71         StreamFile s(stdout, false);
72 #endif
73 
74         StackFrameSP unwind_frame_sp;
75         do
76         {
77             uint32_t idx = m_concrete_frames_fetched++;
78             lldb::addr_t pc;
79             lldb::addr_t cfa;
80             if (idx == 0)
81             {
82                 // We might have already created frame zero, only create it
83                 // if we need to
84                 if (m_frames.empty())
85                 {
86                     m_thread.GetRegisterContext();
87                     assert (m_thread.m_reg_context_sp.get());
88 
89                     const bool success = unwinder->GetFrameInfoAtIndex(idx, cfa, pc);
90                     // There shouldn't be any way not to get the frame info for frame 0.
91                     // But if the unwinder can't make one, lets make one by hand with the
92                     // SP as the CFA and see if that gets any further.
93                     if (!success)
94                     {
95                         cfa = m_thread.GetRegisterContext()->GetSP();
96                         pc = m_thread.GetRegisterContext()->GetPC();
97                     }
98 
99                     unwind_frame_sp.reset (new StackFrame (m_thread.shared_from_this(),
100                                                            m_frames.size(),
101                                                            idx,
102                                                            m_thread.m_reg_context_sp,
103                                                            cfa,
104                                                            pc,
105                                                            NULL));
106                     m_frames.push_back (unwind_frame_sp);
107                 }
108                 else
109                 {
110                     unwind_frame_sp = m_frames.front();
111                     cfa = unwind_frame_sp->m_id.GetCallFrameAddress();
112                 }
113             }
114             else
115             {
116                 const bool success = unwinder->GetFrameInfoAtIndex(idx, cfa, pc);
117                 if (!success)
118                 {
119                     // We've gotten to the end of the stack.
120                     SetAllFramesFetched();
121                     break;
122                 }
123                 unwind_frame_sp.reset (new StackFrame (m_thread.shared_from_this(), m_frames.size(), idx, cfa, pc, NULL));
124                 m_frames.push_back (unwind_frame_sp);
125             }
126 
127             SymbolContext unwind_sc = unwind_frame_sp->GetSymbolContext (eSymbolContextBlock | eSymbolContextFunction);
128             Block *unwind_block = unwind_sc.block;
129             if (unwind_block)
130             {
131                 Address curr_frame_address (unwind_frame_sp->GetFrameCodeAddress());
132                 // Be sure to adjust the frame address to match the address
133                 // that was used to lookup the symbol context above. If we are
134                 // in the first concrete frame, then we lookup using the current
135                 // address, else we decrement the address by one to get the correct
136                 // location.
137                 if (idx > 0)
138                     curr_frame_address.Slide(-1);
139 
140                 SymbolContext next_frame_sc;
141                 Address next_frame_address;
142 
143                 while (unwind_sc.GetParentOfInlinedScope(curr_frame_address, next_frame_sc, next_frame_address))
144                 {
145                         StackFrameSP frame_sp(new StackFrame (m_thread.shared_from_this(),
146                                                               m_frames.size(),
147                                                               idx,
148                                                               unwind_frame_sp->GetRegisterContextSP (),
149                                                               cfa,
150                                                               next_frame_address,
151                                                               &next_frame_sc));
152 
153                         m_frames.push_back (frame_sp);
154                         unwind_sc = next_frame_sc;
155                         curr_frame_address = next_frame_address;
156                 }
157             }
158         } while (m_frames.size() - 1 < end_idx);
159 
160         // Don't try to merge till you've calculated all the frames in this stack.
161         if (GetAllFramesFetched() && m_prev_frames_sp)
162         {
163             StackFrameList *prev_frames = m_prev_frames_sp.get();
164             StackFrameList *curr_frames = this;
165 
166 #if defined (DEBUG_STACK_FRAMES)
167             s.PutCString("\nprev_frames:\n");
168             prev_frames->Dump (&s);
169             s.PutCString("\ncurr_frames:\n");
170             curr_frames->Dump (&s);
171             s.EOL();
172 #endif
173             size_t curr_frame_num, prev_frame_num;
174 
175             for (curr_frame_num = curr_frames->m_frames.size(), prev_frame_num = prev_frames->m_frames.size();
176                  curr_frame_num > 0 && prev_frame_num > 0;
177                  --curr_frame_num, --prev_frame_num)
178             {
179                 const size_t curr_frame_idx = curr_frame_num-1;
180                 const size_t prev_frame_idx = prev_frame_num-1;
181                 StackFrameSP curr_frame_sp (curr_frames->m_frames[curr_frame_idx]);
182                 StackFrameSP prev_frame_sp (prev_frames->m_frames[prev_frame_idx]);
183 
184 #if defined (DEBUG_STACK_FRAMES)
185                 s.Printf("\n\nCurr frame #%u ", curr_frame_idx);
186                 if (curr_frame_sp)
187                     curr_frame_sp->Dump (&s, true, false);
188                 else
189                     s.PutCString("NULL");
190                 s.Printf("\nPrev frame #%u ", prev_frame_idx);
191                 if (prev_frame_sp)
192                     prev_frame_sp->Dump (&s, true, false);
193                 else
194                     s.PutCString("NULL");
195 #endif
196 
197                 StackFrame *curr_frame = curr_frame_sp.get();
198                 StackFrame *prev_frame = prev_frame_sp.get();
199 
200                 if (curr_frame == NULL || prev_frame == NULL)
201                     break;
202 
203                 // Check the stack ID to make sure they are equal
204                 if (curr_frame->GetStackID() != prev_frame->GetStackID())
205                     break;
206 
207                 prev_frame->UpdatePreviousFrameFromCurrentFrame (*curr_frame);
208                 // Now copy the fixed up previous frame into the current frames
209                 // so the pointer doesn't change
210                 m_frames[curr_frame_idx] = prev_frame_sp;
211                 //curr_frame->UpdateCurrentFrameFromPreviousFrame (*prev_frame);
212 
213 #if defined (DEBUG_STACK_FRAMES)
214                 s.Printf("\n    Copying previous frame to current frame");
215 #endif
216             }
217             // We are done with the old stack frame list, we can release it now
218             m_prev_frames_sp.reset();
219         }
220 
221 #if defined (DEBUG_STACK_FRAMES)
222             s.PutCString("\n\nNew frames:\n");
223             Dump (&s);
224             s.EOL();
225 #endif
226     }
227     else
228     {
229         if (end_idx < m_concrete_frames_fetched)
230             return;
231 
232         uint32_t num_frames = unwinder->GetFramesUpTo(end_idx);
233         if (num_frames <= end_idx + 1)
234         {
235             //Done unwinding.
236             m_concrete_frames_fetched = UINT32_MAX;
237         }
238         m_frames.resize(num_frames);
239     }
240 }
241 
242 uint32_t
243 StackFrameList::GetNumFrames (bool can_create)
244 {
245     Mutex::Locker locker (m_mutex);
246 
247     if (can_create)
248         GetFramesUpTo (UINT32_MAX);
249     return m_frames.size();
250 }
251 
252 void
253 StackFrameList::Dump (Stream *s)
254 {
255     if (s == NULL)
256         return;
257     Mutex::Locker locker (m_mutex);
258 
259     const_iterator pos, begin = m_frames.begin(), end = m_frames.end();
260     for (pos = begin; pos != end; ++pos)
261     {
262         StackFrame *frame = (*pos).get();
263         s->Printf("%p: ", frame);
264         if (frame)
265         {
266             frame->GetStackID().Dump (s);
267             frame->DumpUsingSettingsFormat (s);
268         }
269         else
270             s->Printf("frame #%u", (uint32_t)std::distance (begin, pos));
271         s->EOL();
272     }
273     s->EOL();
274 }
275 
276 StackFrameSP
277 StackFrameList::GetFrameAtIndex (uint32_t idx)
278 {
279     StackFrameSP frame_sp;
280     Mutex::Locker locker (m_mutex);
281     if (idx < m_frames.size())
282         frame_sp = m_frames[idx];
283 
284     if (frame_sp)
285         return frame_sp;
286 
287         // GetFramesUpTo will fill m_frames with as many frames as you asked for,
288         // if there are that many.  If there weren't then you asked for too many
289         // frames.
290         GetFramesUpTo (idx);
291         if (idx < m_frames.size())
292         {
293             if (m_show_inlined_frames)
294             {
295                 // When inline frames are enabled we actually create all the frames in GetFramesUpTo.
296                 frame_sp = m_frames[idx];
297             }
298             else
299             {
300                 Unwind *unwinder = m_thread.GetUnwinder ();
301                 if (unwinder)
302                 {
303                     addr_t pc, cfa;
304                     if (unwinder->GetFrameInfoAtIndex(idx, cfa, pc))
305                     {
306                         frame_sp.reset (new StackFrame (m_thread.shared_from_this(), idx, idx, cfa, pc, NULL));
307 
308                         Function *function = frame_sp->GetSymbolContext (eSymbolContextFunction).function;
309                         if (function)
310                         {
311                             // When we aren't showing inline functions we always use
312                             // the top most function block as the scope.
313                             frame_sp->SetSymbolContextScope (&function->GetBlock(false));
314                         }
315                         else
316                         {
317                             // Set the symbol scope from the symbol regardless if it is NULL or valid.
318                             frame_sp->SetSymbolContextScope (frame_sp->GetSymbolContext (eSymbolContextSymbol).symbol);
319                         }
320                         SetFrameAtIndex(idx, frame_sp);
321                     }
322                 }
323             }
324         }
325     return frame_sp;
326 }
327 
328 StackFrameSP
329 StackFrameList::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
330 {
331     // First try assuming the unwind index is the same as the frame index. The
332     // unwind index is always greater than or equal to the frame index, so it
333     // is a good place to start. If we have inlined frames we might have 5
334     // concrete frames (frame unwind indexes go from 0-4), but we might have 15
335     // frames after we make all the inlined frames. Most of the time the unwind
336     // frame index (or the concrete frame index) is the same as the frame index.
337     uint32_t frame_idx = unwind_idx;
338     StackFrameSP frame_sp (GetFrameAtIndex (frame_idx));
339     while (frame_sp)
340     {
341         if (frame_sp->GetFrameIndex() == unwind_idx)
342             break;
343         frame_sp = GetFrameAtIndex (++frame_idx);
344     }
345     return frame_sp;
346 }
347 
348 StackFrameSP
349 StackFrameList::GetFrameWithStackID (const StackID &stack_id)
350 {
351     uint32_t frame_idx = 0;
352     StackFrameSP frame_sp;
353     do
354     {
355         frame_sp = GetFrameAtIndex (frame_idx);
356         if (frame_sp && frame_sp->GetStackID() == stack_id)
357             break;
358         frame_idx++;
359     }
360     while (frame_sp);
361     return frame_sp;
362 }
363 
364 bool
365 StackFrameList::SetFrameAtIndex (uint32_t idx, StackFrameSP &frame_sp)
366 {
367     if (idx >= m_frames.size())
368         m_frames.resize(idx + 1);
369     // Make sure allocation succeeded by checking bounds again
370     if (idx < m_frames.size())
371     {
372         m_frames[idx] = frame_sp;
373         return true;
374     }
375     return false;   // resize failed, out of memory?
376 }
377 
378 uint32_t
379 StackFrameList::GetSelectedFrameIndex () const
380 {
381     Mutex::Locker locker (m_mutex);
382     return m_selected_frame_idx;
383 }
384 
385 
386 uint32_t
387 StackFrameList::SetSelectedFrame (lldb_private::StackFrame *frame)
388 {
389     Mutex::Locker locker (m_mutex);
390     const_iterator pos;
391     const_iterator begin = m_frames.begin();
392     const_iterator end = m_frames.end();
393     m_selected_frame_idx = 0;
394     for (pos = begin; pos != end; ++pos)
395     {
396         if (pos->get() == frame)
397         {
398             m_selected_frame_idx = std::distance (begin, pos);
399             break;
400         }
401     }
402     SetDefaultFileAndLineToSelectedFrame();
403     return m_selected_frame_idx;
404 }
405 
406 // Mark a stack frame as the current frame using the frame index
407 bool
408 StackFrameList::SetSelectedFrameByIndex (uint32_t idx)
409 {
410     Mutex::Locker locker (m_mutex);
411     StackFrameSP frame_sp (GetFrameAtIndex (idx));
412     if (frame_sp)
413     {
414         SetSelectedFrame(frame_sp.get());
415         return true;
416     }
417     else
418         return false;
419 }
420 
421 void
422 StackFrameList::SetDefaultFileAndLineToSelectedFrame()
423 {
424     if (m_thread.GetID() == m_thread.GetProcess()->GetThreadList().GetSelectedThread()->GetID())
425     {
426         StackFrameSP frame_sp (GetFrameAtIndex (GetSelectedFrameIndex()));
427         if (frame_sp)
428         {
429             SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextLineEntry);
430             if (sc.line_entry.file)
431                 m_thread.CalculateTarget()->GetSourceManager().SetDefaultFileAndLine (sc.line_entry.file,
432                                                                                             sc.line_entry.line);
433         }
434     }
435 }
436 
437 // The thread has been run, reset the number stack frames to zero so we can
438 // determine how many frames we have lazily.
439 void
440 StackFrameList::Clear ()
441 {
442     Mutex::Locker locker (m_mutex);
443     m_frames.clear();
444     m_concrete_frames_fetched = 0;
445 }
446 
447 void
448 StackFrameList::InvalidateFrames (uint32_t start_idx)
449 {
450     Mutex::Locker locker (m_mutex);
451     if (m_show_inlined_frames)
452     {
453         Clear();
454     }
455     else
456     {
457         const size_t num_frames = m_frames.size();
458         while (start_idx < num_frames)
459         {
460             m_frames[start_idx].reset();
461             ++start_idx;
462         }
463     }
464 }
465 
466 void
467 StackFrameList::Merge (std::auto_ptr<StackFrameList>& curr_ap, lldb::StackFrameListSP& prev_sp)
468 {
469     Mutex::Locker curr_locker (curr_ap.get() ? curr_ap->m_mutex.GetMutex() : NULL);
470     Mutex::Locker prev_locker (prev_sp.get() ? prev_sp->m_mutex.GetMutex() : NULL);
471 
472 #if defined (DEBUG_STACK_FRAMES)
473     StreamFile s(stdout, false);
474     s.PutCString("\n\nStackFrameList::Merge():\nPrev:\n");
475     if (prev_sp.get())
476         prev_sp->Dump (&s);
477     else
478         s.PutCString ("NULL");
479     s.PutCString("\nCurr:\n");
480     if (curr_ap.get())
481         curr_ap->Dump (&s);
482     else
483         s.PutCString ("NULL");
484     s.EOL();
485 #endif
486 
487     if (curr_ap.get() == NULL || curr_ap->GetNumFrames (false) == 0)
488     {
489 #if defined (DEBUG_STACK_FRAMES)
490         s.PutCString("No current frames, leave previous frames alone...\n");
491 #endif
492         curr_ap.release();
493         return;
494     }
495 
496     if (prev_sp.get() == NULL || prev_sp->GetNumFrames (false) == 0)
497     {
498 #if defined (DEBUG_STACK_FRAMES)
499         s.PutCString("No previous frames, so use current frames...\n");
500 #endif
501         // We either don't have any previous frames, or since we have more than
502         // one current frames it means we have all the frames and can safely
503         // replace our previous frames.
504         prev_sp.reset (curr_ap.release());
505         return;
506     }
507 
508     const uint32_t num_curr_frames = curr_ap->GetNumFrames (false);
509 
510     if (num_curr_frames > 1)
511     {
512 #if defined (DEBUG_STACK_FRAMES)
513         s.PutCString("We have more than one current frame, so use current frames...\n");
514 #endif
515         // We have more than one current frames it means we have all the frames
516         // and can safely replace our previous frames.
517         prev_sp.reset (curr_ap.release());
518 
519 #if defined (DEBUG_STACK_FRAMES)
520         s.PutCString("\nMerged:\n");
521         prev_sp->Dump (&s);
522 #endif
523         return;
524     }
525 
526     StackFrameSP prev_frame_zero_sp(prev_sp->GetFrameAtIndex (0));
527     StackFrameSP curr_frame_zero_sp(curr_ap->GetFrameAtIndex (0));
528     StackID curr_stack_id (curr_frame_zero_sp->GetStackID());
529     StackID prev_stack_id (prev_frame_zero_sp->GetStackID());
530 
531 #if defined (DEBUG_STACK_FRAMES)
532     const uint32_t num_prev_frames = prev_sp->GetNumFrames (false);
533     s.Printf("\n%u previous frames with one current frame\n", num_prev_frames);
534 #endif
535 
536     // We have only a single current frame
537     // Our previous stack frames only had a single frame as well...
538     if (curr_stack_id == prev_stack_id)
539     {
540 #if defined (DEBUG_STACK_FRAMES)
541         s.Printf("\nPrevious frame #0 is same as current frame #0, merge the cached data\n");
542 #endif
543 
544         curr_frame_zero_sp->UpdateCurrentFrameFromPreviousFrame (*prev_frame_zero_sp);
545 //        prev_frame_zero_sp->UpdatePreviousFrameFromCurrentFrame (*curr_frame_zero_sp);
546 //        prev_sp->SetFrameAtIndex (0, prev_frame_zero_sp);
547     }
548     else if (curr_stack_id < prev_stack_id)
549     {
550 #if defined (DEBUG_STACK_FRAMES)
551         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");
552 #endif
553         prev_sp->m_frames.insert (prev_sp->m_frames.begin(), curr_frame_zero_sp);
554     }
555 
556     curr_ap.release();
557 
558 #if defined (DEBUG_STACK_FRAMES)
559     s.PutCString("\nMerged:\n");
560     prev_sp->Dump (&s);
561 #endif
562 
563 
564 }
565 
566 lldb::StackFrameSP
567 StackFrameList::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
568 {
569     const_iterator pos;
570     const_iterator begin = m_frames.begin();
571     const_iterator end = m_frames.end();
572     lldb::StackFrameSP ret_sp;
573 
574     for (pos = begin; pos != end; ++pos)
575     {
576         if (pos->get() == stack_frame_ptr)
577         {
578             ret_sp = (*pos);
579             break;
580         }
581     }
582     return ret_sp;
583 }
584 
585 size_t
586 StackFrameList::GetStatus (Stream& strm,
587                            uint32_t first_frame,
588                            uint32_t num_frames,
589                            bool show_frame_info,
590                            uint32_t num_frames_with_source,
591                            uint32_t source_lines_before,
592                            uint32_t source_lines_after)
593 {
594     size_t num_frames_displayed = 0;
595 
596     if (num_frames == 0)
597         return 0;
598 
599     StackFrameSP frame_sp;
600     uint32_t frame_idx = 0;
601     uint32_t last_frame;
602 
603     // Don't let the last frame wrap around...
604     if (num_frames == UINT32_MAX)
605         last_frame = UINT32_MAX;
606     else
607         last_frame = first_frame + num_frames;
608 
609     for (frame_idx = first_frame; frame_idx < last_frame; ++frame_idx)
610     {
611         frame_sp = GetFrameAtIndex(frame_idx);
612         if (frame_sp.get() == NULL)
613             break;
614 
615         if (!frame_sp->GetStatus (strm,
616                                   show_frame_info,
617                                   num_frames_with_source > first_frame - frame_idx,
618                                   source_lines_before,
619                                   source_lines_after))
620             break;
621         ++num_frames_displayed;
622     }
623 
624     strm.IndentLess();
625     return num_frames_displayed;
626 }
627 
628