1 //===-- StackFrameList.cpp --------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "lldb/Target/StackFrameList.h"
10 #include "lldb/Breakpoint/Breakpoint.h"
11 #include "lldb/Breakpoint/BreakpointLocation.h"
12 #include "lldb/Core/SourceManager.h"
13 #include "lldb/Core/StreamFile.h"
14 #include "lldb/Symbol/Block.h"
15 #include "lldb/Symbol/Function.h"
16 #include "lldb/Symbol/Symbol.h"
17 #include "lldb/Target/Process.h"
18 #include "lldb/Target/RegisterContext.h"
19 #include "lldb/Target/StackFrame.h"
20 #include "lldb/Target/StopInfo.h"
21 #include "lldb/Target/Target.h"
22 #include "lldb/Target/Thread.h"
23 #include "lldb/Target/Unwind.h"
24 #include "lldb/Utility/Log.h"
25 #include "llvm/ADT/SmallPtrSet.h"
26
27 #include <memory>
28
29 //#define DEBUG_STACK_FRAMES 1
30
31 using namespace lldb;
32 using namespace lldb_private;
33
34 // StackFrameList constructor
StackFrameList(Thread & thread,const lldb::StackFrameListSP & prev_frames_sp,bool show_inline_frames)35 StackFrameList::StackFrameList(Thread &thread,
36 const lldb::StackFrameListSP &prev_frames_sp,
37 bool show_inline_frames)
38 : m_thread(thread), m_prev_frames_sp(prev_frames_sp), m_mutex(), m_frames(),
39 m_selected_frame_idx(0), m_concrete_frames_fetched(0),
40 m_current_inlined_depth(UINT32_MAX),
41 m_current_inlined_pc(LLDB_INVALID_ADDRESS),
42 m_show_inlined_frames(show_inline_frames) {
43 if (prev_frames_sp) {
44 m_current_inlined_depth = prev_frames_sp->m_current_inlined_depth;
45 m_current_inlined_pc = prev_frames_sp->m_current_inlined_pc;
46 }
47 }
48
~StackFrameList()49 StackFrameList::~StackFrameList() {
50 // Call clear since this takes a lock and clears the stack frame list in case
51 // another thread is currently using this stack frame list
52 Clear();
53 }
54
CalculateCurrentInlinedDepth()55 void StackFrameList::CalculateCurrentInlinedDepth() {
56 uint32_t cur_inlined_depth = GetCurrentInlinedDepth();
57 if (cur_inlined_depth == UINT32_MAX) {
58 ResetCurrentInlinedDepth();
59 }
60 }
61
GetCurrentInlinedDepth()62 uint32_t StackFrameList::GetCurrentInlinedDepth() {
63 if (m_show_inlined_frames && m_current_inlined_pc != LLDB_INVALID_ADDRESS) {
64 lldb::addr_t cur_pc = m_thread.GetRegisterContext()->GetPC();
65 if (cur_pc != m_current_inlined_pc) {
66 m_current_inlined_pc = LLDB_INVALID_ADDRESS;
67 m_current_inlined_depth = UINT32_MAX;
68 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
69 if (log && log->GetVerbose())
70 LLDB_LOGF(
71 log,
72 "GetCurrentInlinedDepth: invalidating current inlined depth.\n");
73 }
74 return m_current_inlined_depth;
75 } else {
76 return UINT32_MAX;
77 }
78 }
79
ResetCurrentInlinedDepth()80 void StackFrameList::ResetCurrentInlinedDepth() {
81 if (!m_show_inlined_frames)
82 return;
83
84 std::lock_guard<std::recursive_mutex> guard(m_mutex);
85
86 GetFramesUpTo(0);
87 if (m_frames.empty())
88 return;
89 if (!m_frames[0]->IsInlined()) {
90 m_current_inlined_depth = UINT32_MAX;
91 m_current_inlined_pc = LLDB_INVALID_ADDRESS;
92 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
93 if (log && log->GetVerbose())
94 LLDB_LOGF(
95 log,
96 "ResetCurrentInlinedDepth: Invalidating current inlined depth.\n");
97 return;
98 }
99
100 // We only need to do something special about inlined blocks when we are
101 // at the beginning of an inlined function:
102 // FIXME: We probably also have to do something special if the PC is at
103 // the END of an inlined function, which coincides with the end of either
104 // its containing function or another inlined function.
105
106 Block *block_ptr = m_frames[0]->GetFrameBlock();
107 if (!block_ptr)
108 return;
109
110 Address pc_as_address;
111 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
112 pc_as_address.SetLoadAddress(curr_pc, &(m_thread.GetProcess()->GetTarget()));
113 AddressRange containing_range;
114 if (!block_ptr->GetRangeContainingAddress(pc_as_address, containing_range) ||
115 pc_as_address != containing_range.GetBaseAddress())
116 return;
117
118 // If we got here because of a breakpoint hit, then set the inlined depth
119 // depending on where the breakpoint was set. If we got here because of a
120 // crash, then set the inlined depth to the deepest most block. Otherwise,
121 // we stopped here naturally as the result of a step, so set ourselves in the
122 // containing frame of the whole set of nested inlines, so the user can then
123 // "virtually" step into the frames one by one, or next over the whole mess.
124 // Note: We don't have to handle being somewhere in the middle of the stack
125 // here, since ResetCurrentInlinedDepth doesn't get called if there is a
126 // valid inlined depth set.
127 StopInfoSP stop_info_sp = m_thread.GetStopInfo();
128 if (!stop_info_sp)
129 return;
130 switch (stop_info_sp->GetStopReason()) {
131 case eStopReasonWatchpoint:
132 case eStopReasonException:
133 case eStopReasonExec:
134 case eStopReasonSignal:
135 // In all these cases we want to stop in the deepest frame.
136 m_current_inlined_pc = curr_pc;
137 m_current_inlined_depth = 0;
138 break;
139 case eStopReasonBreakpoint: {
140 // FIXME: Figure out what this break point is doing, and set the inline
141 // depth appropriately. Be careful to take into account breakpoints that
142 // implement step over prologue, since that should do the default
143 // calculation. For now, if the breakpoints corresponding to this hit are
144 // all internal, I set the stop location to the top of the inlined stack,
145 // since that will make things like stepping over prologues work right.
146 // But if there are any non-internal breakpoints I do to the bottom of the
147 // stack, since that was the old behavior.
148 uint32_t bp_site_id = stop_info_sp->GetValue();
149 BreakpointSiteSP bp_site_sp(
150 m_thread.GetProcess()->GetBreakpointSiteList().FindByID(bp_site_id));
151 bool all_internal = true;
152 if (bp_site_sp) {
153 uint32_t num_owners = bp_site_sp->GetNumberOfOwners();
154 for (uint32_t i = 0; i < num_owners; i++) {
155 Breakpoint &bp_ref = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint();
156 if (!bp_ref.IsInternal()) {
157 all_internal = false;
158 }
159 }
160 }
161 if (!all_internal) {
162 m_current_inlined_pc = curr_pc;
163 m_current_inlined_depth = 0;
164 break;
165 }
166 }
167 LLVM_FALLTHROUGH;
168 default: {
169 // Otherwise, we should set ourselves at the container of the inlining, so
170 // that the user can descend into them. So first we check whether we have
171 // more than one inlined block sharing this PC:
172 int num_inlined_functions = 0;
173
174 for (Block *container_ptr = block_ptr->GetInlinedParent();
175 container_ptr != nullptr;
176 container_ptr = container_ptr->GetInlinedParent()) {
177 if (!container_ptr->GetRangeContainingAddress(pc_as_address,
178 containing_range))
179 break;
180 if (pc_as_address != containing_range.GetBaseAddress())
181 break;
182
183 num_inlined_functions++;
184 }
185 m_current_inlined_pc = curr_pc;
186 m_current_inlined_depth = num_inlined_functions + 1;
187 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
188 if (log && log->GetVerbose())
189 LLDB_LOGF(log,
190 "ResetCurrentInlinedDepth: setting inlined "
191 "depth: %d 0x%" PRIx64 ".\n",
192 m_current_inlined_depth, curr_pc);
193
194 break;
195 }
196 }
197 }
198
DecrementCurrentInlinedDepth()199 bool StackFrameList::DecrementCurrentInlinedDepth() {
200 if (m_show_inlined_frames) {
201 uint32_t current_inlined_depth = GetCurrentInlinedDepth();
202 if (current_inlined_depth != UINT32_MAX) {
203 if (current_inlined_depth > 0) {
204 m_current_inlined_depth--;
205 return true;
206 }
207 }
208 }
209 return false;
210 }
211
SetCurrentInlinedDepth(uint32_t new_depth)212 void StackFrameList::SetCurrentInlinedDepth(uint32_t new_depth) {
213 m_current_inlined_depth = new_depth;
214 if (new_depth == UINT32_MAX)
215 m_current_inlined_pc = LLDB_INVALID_ADDRESS;
216 else
217 m_current_inlined_pc = m_thread.GetRegisterContext()->GetPC();
218 }
219
GetOnlyConcreteFramesUpTo(uint32_t end_idx,Unwind * unwinder)220 void StackFrameList::GetOnlyConcreteFramesUpTo(uint32_t end_idx,
221 Unwind *unwinder) {
222 assert(m_thread.IsValid() && "Expected valid thread");
223 assert(m_frames.size() <= end_idx && "Expected there to be frames to fill");
224
225 if (end_idx < m_concrete_frames_fetched)
226 return;
227
228 if (!unwinder)
229 return;
230
231 uint32_t num_frames = unwinder->GetFramesUpTo(end_idx);
232 if (num_frames <= end_idx + 1) {
233 // Done unwinding.
234 m_concrete_frames_fetched = UINT32_MAX;
235 }
236
237 // Don't create the frames eagerly. Defer this work to GetFrameAtIndex,
238 // which can lazily query the unwinder to create frames.
239 m_frames.resize(num_frames);
240 }
241
242 /// Find the unique path through the call graph from \p begin (with return PC
243 /// \p return_pc) to \p end. On success this path is stored into \p path, and
244 /// on failure \p path is unchanged.
FindInterveningFrames(Function & begin,Function & end,ExecutionContext & exe_ctx,Target & target,addr_t return_pc,std::vector<Function * > & path,ModuleList & images,Log * log)245 static void FindInterveningFrames(Function &begin, Function &end,
246 ExecutionContext &exe_ctx, Target &target,
247 addr_t return_pc,
248 std::vector<Function *> &path,
249 ModuleList &images, Log *log) {
250 LLDB_LOG(log, "Finding frames between {0} and {1}, retn-pc={2:x}",
251 begin.GetDisplayName(), end.GetDisplayName(), return_pc);
252
253 // Find a non-tail calling edge with the correct return PC.
254 if (log)
255 for (const auto &edge : begin.GetCallEdges())
256 LLDB_LOG(log, "FindInterveningFrames: found call with retn-PC = {0:x}",
257 edge->GetReturnPCAddress(begin, target));
258 CallEdge *first_edge = begin.GetCallEdgeForReturnAddress(return_pc, target);
259 if (!first_edge) {
260 LLDB_LOG(log, "No call edge outgoing from {0} with retn-PC == {1:x}",
261 begin.GetDisplayName(), return_pc);
262 return;
263 }
264
265 // The first callee may not be resolved, or there may be nothing to fill in.
266 Function *first_callee = first_edge->GetCallee(images, exe_ctx);
267 if (!first_callee) {
268 LLDB_LOG(log, "Could not resolve callee");
269 return;
270 }
271 if (first_callee == &end) {
272 LLDB_LOG(log, "Not searching further, first callee is {0} (retn-PC: {1:x})",
273 end.GetDisplayName(), return_pc);
274 return;
275 }
276
277 // Run DFS on the tail-calling edges out of the first callee to find \p end.
278 // Fully explore the set of functions reachable from the first edge via tail
279 // calls in order to detect ambiguous executions.
280 struct DFS {
281 std::vector<Function *> active_path = {};
282 std::vector<Function *> solution_path = {};
283 llvm::SmallPtrSet<Function *, 2> visited_nodes = {};
284 bool ambiguous = false;
285 Function *end;
286 ModuleList &images;
287 ExecutionContext &context;
288
289 DFS(Function *end, ModuleList &images, ExecutionContext &context)
290 : end(end), images(images), context(context) {}
291
292 void search(Function &first_callee, std::vector<Function *> &path) {
293 dfs(first_callee);
294 if (!ambiguous)
295 path = std::move(solution_path);
296 }
297
298 void dfs(Function &callee) {
299 // Found a path to the target function.
300 if (&callee == end) {
301 if (solution_path.empty())
302 solution_path = active_path;
303 else
304 ambiguous = true;
305 return;
306 }
307
308 // Terminate the search if tail recursion is found, or more generally if
309 // there's more than one way to reach a target. This errs on the side of
310 // caution: it conservatively stops searching when some solutions are
311 // still possible to save time in the average case.
312 if (!visited_nodes.insert(&callee).second) {
313 ambiguous = true;
314 return;
315 }
316
317 // Search the calls made from this callee.
318 active_path.push_back(&callee);
319 for (const auto &edge : callee.GetTailCallingEdges()) {
320 Function *next_callee = edge->GetCallee(images, context);
321 if (!next_callee)
322 continue;
323
324 dfs(*next_callee);
325 if (ambiguous)
326 return;
327 }
328 active_path.pop_back();
329 }
330 };
331
332 DFS(&end, images, exe_ctx).search(*first_callee, path);
333 }
334
335 /// Given that \p next_frame will be appended to the frame list, synthesize
336 /// tail call frames between the current end of the list and \p next_frame.
337 /// If any frames are added, adjust the frame index of \p next_frame.
338 ///
339 /// --------------
340 /// | ... | <- Completed frames.
341 /// --------------
342 /// | prev_frame |
343 /// --------------
344 /// | ... | <- Artificial frames inserted here.
345 /// --------------
346 /// | next_frame |
347 /// --------------
348 /// | ... | <- Not-yet-visited frames.
349 /// --------------
SynthesizeTailCallFrames(StackFrame & next_frame)350 void StackFrameList::SynthesizeTailCallFrames(StackFrame &next_frame) {
351 TargetSP target_sp = next_frame.CalculateTarget();
352 if (!target_sp)
353 return;
354
355 lldb::RegisterContextSP next_reg_ctx_sp = next_frame.GetRegisterContext();
356 if (!next_reg_ctx_sp)
357 return;
358
359 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
360
361 assert(!m_frames.empty() && "Cannot synthesize frames in an empty stack");
362 StackFrame &prev_frame = *m_frames.back().get();
363
364 // Find the functions prev_frame and next_frame are stopped in. The function
365 // objects are needed to search the lazy call graph for intervening frames.
366 Function *prev_func =
367 prev_frame.GetSymbolContext(eSymbolContextFunction).function;
368 if (!prev_func) {
369 LLDB_LOG(log, "SynthesizeTailCallFrames: can't find previous function");
370 return;
371 }
372 Function *next_func =
373 next_frame.GetSymbolContext(eSymbolContextFunction).function;
374 if (!next_func) {
375 LLDB_LOG(log, "SynthesizeTailCallFrames: can't find next function");
376 return;
377 }
378
379 // Try to find the unique sequence of (tail) calls which led from next_frame
380 // to prev_frame.
381 std::vector<Function *> path;
382 addr_t return_pc = next_reg_ctx_sp->GetPC();
383 Target &target = *target_sp.get();
384 ModuleList &images = next_frame.CalculateTarget()->GetImages();
385 ExecutionContext exe_ctx(target_sp, /*get_process=*/true);
386 exe_ctx.SetFramePtr(&next_frame);
387 FindInterveningFrames(*next_func, *prev_func, exe_ctx, target, return_pc,
388 path, images, log);
389
390 // Push synthetic tail call frames.
391 for (Function *callee : llvm::reverse(path)) {
392 uint32_t frame_idx = m_frames.size();
393 uint32_t concrete_frame_idx = next_frame.GetConcreteFrameIndex();
394 addr_t cfa = LLDB_INVALID_ADDRESS;
395 bool cfa_is_valid = false;
396 addr_t pc =
397 callee->GetAddressRange().GetBaseAddress().GetLoadAddress(&target);
398 constexpr bool behaves_like_zeroth_frame = false;
399 SymbolContext sc;
400 callee->CalculateSymbolContext(&sc);
401 auto synth_frame = std::make_shared<StackFrame>(
402 m_thread.shared_from_this(), frame_idx, concrete_frame_idx, cfa,
403 cfa_is_valid, pc, StackFrame::Kind::Artificial,
404 behaves_like_zeroth_frame, &sc);
405 m_frames.push_back(synth_frame);
406 LLDB_LOG(log, "Pushed frame {0}", callee->GetDisplayName());
407 }
408
409 // If any frames were created, adjust next_frame's index.
410 if (!path.empty())
411 next_frame.SetFrameIndex(m_frames.size());
412 }
413
GetFramesUpTo(uint32_t end_idx)414 void StackFrameList::GetFramesUpTo(uint32_t end_idx) {
415 // Do not fetch frames for an invalid thread.
416 if (!m_thread.IsValid())
417 return;
418
419 // We've already gotten more frames than asked for, or we've already finished
420 // unwinding, return.
421 if (m_frames.size() > end_idx || GetAllFramesFetched())
422 return;
423
424 Unwind *unwinder = m_thread.GetUnwinder();
425
426 if (!m_show_inlined_frames) {
427 GetOnlyConcreteFramesUpTo(end_idx, unwinder);
428 return;
429 }
430
431 #if defined(DEBUG_STACK_FRAMES)
432 StreamFile s(stdout, false);
433 #endif
434 // If we are hiding some frames from the outside world, we need to add
435 // those onto the total count of frames to fetch. However, we don't need
436 // to do that if end_idx is 0 since in that case we always get the first
437 // concrete frame and all the inlined frames below it... And of course, if
438 // end_idx is UINT32_MAX that means get all, so just do that...
439
440 uint32_t inlined_depth = 0;
441 if (end_idx > 0 && end_idx != UINT32_MAX) {
442 inlined_depth = GetCurrentInlinedDepth();
443 if (inlined_depth != UINT32_MAX) {
444 if (end_idx > 0)
445 end_idx += inlined_depth;
446 }
447 }
448
449 StackFrameSP unwind_frame_sp;
450 do {
451 uint32_t idx = m_concrete_frames_fetched++;
452 lldb::addr_t pc = LLDB_INVALID_ADDRESS;
453 lldb::addr_t cfa = LLDB_INVALID_ADDRESS;
454 bool behaves_like_zeroth_frame = (idx == 0);
455 if (idx == 0) {
456 // We might have already created frame zero, only create it if we need
457 // to.
458 if (m_frames.empty()) {
459 RegisterContextSP reg_ctx_sp(m_thread.GetRegisterContext());
460
461 if (reg_ctx_sp) {
462 const bool success = unwinder &&
463 unwinder->GetFrameInfoAtIndex(
464 idx, cfa, pc, behaves_like_zeroth_frame);
465 // There shouldn't be any way not to get the frame info for frame
466 // 0. But if the unwinder can't make one, lets make one by hand
467 // with the SP as the CFA and see if that gets any further.
468 if (!success) {
469 cfa = reg_ctx_sp->GetSP();
470 pc = reg_ctx_sp->GetPC();
471 }
472
473 unwind_frame_sp = std::make_shared<StackFrame>(
474 m_thread.shared_from_this(), m_frames.size(), idx, reg_ctx_sp,
475 cfa, pc, behaves_like_zeroth_frame, nullptr);
476 m_frames.push_back(unwind_frame_sp);
477 }
478 } else {
479 unwind_frame_sp = m_frames.front();
480 cfa = unwind_frame_sp->m_id.GetCallFrameAddress();
481 }
482 } else {
483 const bool success = unwinder &&
484 unwinder->GetFrameInfoAtIndex(
485 idx, cfa, pc, behaves_like_zeroth_frame);
486 if (!success) {
487 // We've gotten to the end of the stack.
488 SetAllFramesFetched();
489 break;
490 }
491 const bool cfa_is_valid = true;
492 unwind_frame_sp = std::make_shared<StackFrame>(
493 m_thread.shared_from_this(), m_frames.size(), idx, cfa, cfa_is_valid,
494 pc, StackFrame::Kind::Regular, behaves_like_zeroth_frame, nullptr);
495
496 // Create synthetic tail call frames between the previous frame and the
497 // newly-found frame. The new frame's index may change after this call,
498 // although its concrete index will stay the same.
499 SynthesizeTailCallFrames(*unwind_frame_sp.get());
500
501 m_frames.push_back(unwind_frame_sp);
502 }
503
504 assert(unwind_frame_sp);
505 SymbolContext unwind_sc = unwind_frame_sp->GetSymbolContext(
506 eSymbolContextBlock | eSymbolContextFunction);
507 Block *unwind_block = unwind_sc.block;
508 if (unwind_block) {
509 Address curr_frame_address(unwind_frame_sp->GetFrameCodeAddress());
510 TargetSP target_sp = m_thread.CalculateTarget();
511 // Be sure to adjust the frame address to match the address that was
512 // used to lookup the symbol context above. If we are in the first
513 // concrete frame, then we lookup using the current address, else we
514 // decrement the address by one to get the correct location.
515 if (idx > 0) {
516 if (curr_frame_address.GetOffset() == 0) {
517 // If curr_frame_address points to the first address in a section
518 // then after adjustment it will point to an other section. In that
519 // case resolve the address again to the correct section plus
520 // offset form.
521 addr_t load_addr = curr_frame_address.GetOpcodeLoadAddress(
522 target_sp.get(), AddressClass::eCode);
523 curr_frame_address.SetOpcodeLoadAddress(
524 load_addr - 1, target_sp.get(), AddressClass::eCode);
525 } else {
526 curr_frame_address.Slide(-1);
527 }
528 }
529
530 SymbolContext next_frame_sc;
531 Address next_frame_address;
532
533 while (unwind_sc.GetParentOfInlinedScope(
534 curr_frame_address, next_frame_sc, next_frame_address)) {
535 next_frame_sc.line_entry.ApplyFileMappings(target_sp);
536 behaves_like_zeroth_frame = false;
537 StackFrameSP frame_sp(new StackFrame(
538 m_thread.shared_from_this(), m_frames.size(), idx,
539 unwind_frame_sp->GetRegisterContextSP(), cfa, next_frame_address,
540 behaves_like_zeroth_frame, &next_frame_sc));
541
542 m_frames.push_back(frame_sp);
543 unwind_sc = next_frame_sc;
544 curr_frame_address = next_frame_address;
545 }
546 }
547 } while (m_frames.size() - 1 < end_idx);
548
549 // Don't try to merge till you've calculated all the frames in this stack.
550 if (GetAllFramesFetched() && m_prev_frames_sp) {
551 StackFrameList *prev_frames = m_prev_frames_sp.get();
552 StackFrameList *curr_frames = this;
553
554 #if defined(DEBUG_STACK_FRAMES)
555 s.PutCString("\nprev_frames:\n");
556 prev_frames->Dump(&s);
557 s.PutCString("\ncurr_frames:\n");
558 curr_frames->Dump(&s);
559 s.EOL();
560 #endif
561 size_t curr_frame_num, prev_frame_num;
562
563 for (curr_frame_num = curr_frames->m_frames.size(),
564 prev_frame_num = prev_frames->m_frames.size();
565 curr_frame_num > 0 && prev_frame_num > 0;
566 --curr_frame_num, --prev_frame_num) {
567 const size_t curr_frame_idx = curr_frame_num - 1;
568 const size_t prev_frame_idx = prev_frame_num - 1;
569 StackFrameSP curr_frame_sp(curr_frames->m_frames[curr_frame_idx]);
570 StackFrameSP prev_frame_sp(prev_frames->m_frames[prev_frame_idx]);
571
572 #if defined(DEBUG_STACK_FRAMES)
573 s.Printf("\n\nCurr frame #%u ", curr_frame_idx);
574 if (curr_frame_sp)
575 curr_frame_sp->Dump(&s, true, false);
576 else
577 s.PutCString("NULL");
578 s.Printf("\nPrev frame #%u ", prev_frame_idx);
579 if (prev_frame_sp)
580 prev_frame_sp->Dump(&s, true, false);
581 else
582 s.PutCString("NULL");
583 #endif
584
585 StackFrame *curr_frame = curr_frame_sp.get();
586 StackFrame *prev_frame = prev_frame_sp.get();
587
588 if (curr_frame == nullptr || prev_frame == nullptr)
589 break;
590
591 // Check the stack ID to make sure they are equal.
592 if (curr_frame->GetStackID() != prev_frame->GetStackID())
593 break;
594
595 prev_frame->UpdatePreviousFrameFromCurrentFrame(*curr_frame);
596 // Now copy the fixed up previous frame into the current frames so the
597 // pointer doesn't change.
598 m_frames[curr_frame_idx] = prev_frame_sp;
599
600 #if defined(DEBUG_STACK_FRAMES)
601 s.Printf("\n Copying previous frame to current frame");
602 #endif
603 }
604 // We are done with the old stack frame list, we can release it now.
605 m_prev_frames_sp.reset();
606 }
607
608 #if defined(DEBUG_STACK_FRAMES)
609 s.PutCString("\n\nNew frames:\n");
610 Dump(&s);
611 s.EOL();
612 #endif
613 }
614
GetNumFrames(bool can_create)615 uint32_t StackFrameList::GetNumFrames(bool can_create) {
616 std::lock_guard<std::recursive_mutex> guard(m_mutex);
617
618 if (can_create)
619 GetFramesUpTo(UINT32_MAX);
620
621 return GetVisibleStackFrameIndex(m_frames.size());
622 }
623
Dump(Stream * s)624 void StackFrameList::Dump(Stream *s) {
625 if (s == nullptr)
626 return;
627
628 std::lock_guard<std::recursive_mutex> guard(m_mutex);
629
630 const_iterator pos, begin = m_frames.begin(), end = m_frames.end();
631 for (pos = begin; pos != end; ++pos) {
632 StackFrame *frame = (*pos).get();
633 s->Printf("%p: ", static_cast<void *>(frame));
634 if (frame) {
635 frame->GetStackID().Dump(s);
636 frame->DumpUsingSettingsFormat(s);
637 } else
638 s->Printf("frame #%u", (uint32_t)std::distance(begin, pos));
639 s->EOL();
640 }
641 s->EOL();
642 }
643
GetFrameAtIndex(uint32_t idx)644 StackFrameSP StackFrameList::GetFrameAtIndex(uint32_t idx) {
645 StackFrameSP frame_sp;
646 std::lock_guard<std::recursive_mutex> guard(m_mutex);
647 uint32_t original_idx = idx;
648
649 uint32_t inlined_depth = GetCurrentInlinedDepth();
650 if (inlined_depth != UINT32_MAX)
651 idx += inlined_depth;
652
653 if (idx < m_frames.size())
654 frame_sp = m_frames[idx];
655
656 if (frame_sp)
657 return frame_sp;
658
659 // GetFramesUpTo will fill m_frames with as many frames as you asked for, if
660 // there are that many. If there weren't then you asked for too many frames.
661 GetFramesUpTo(idx);
662 if (idx < m_frames.size()) {
663 if (m_show_inlined_frames) {
664 // When inline frames are enabled we actually create all the frames in
665 // GetFramesUpTo.
666 frame_sp = m_frames[idx];
667 } else {
668 Unwind *unwinder = m_thread.GetUnwinder();
669 if (unwinder) {
670 addr_t pc, cfa;
671 bool behaves_like_zeroth_frame = (idx == 0);
672 if (unwinder->GetFrameInfoAtIndex(idx, cfa, pc,
673 behaves_like_zeroth_frame)) {
674 const bool cfa_is_valid = true;
675 frame_sp = std::make_shared<StackFrame>(
676 m_thread.shared_from_this(), idx, idx, cfa, cfa_is_valid, pc,
677 StackFrame::Kind::Regular, behaves_like_zeroth_frame, nullptr);
678
679 Function *function =
680 frame_sp->GetSymbolContext(eSymbolContextFunction).function;
681 if (function) {
682 // When we aren't showing inline functions we always use the top
683 // most function block as the scope.
684 frame_sp->SetSymbolContextScope(&function->GetBlock(false));
685 } else {
686 // Set the symbol scope from the symbol regardless if it is nullptr
687 // or valid.
688 frame_sp->SetSymbolContextScope(
689 frame_sp->GetSymbolContext(eSymbolContextSymbol).symbol);
690 }
691 SetFrameAtIndex(idx, frame_sp);
692 }
693 }
694 }
695 } else if (original_idx == 0) {
696 // There should ALWAYS be a frame at index 0. If something went wrong with
697 // the CurrentInlinedDepth such that there weren't as many frames as we
698 // thought taking that into account, then reset the current inlined depth
699 // and return the real zeroth frame.
700 if (m_frames.empty()) {
701 // Why do we have a thread with zero frames, that should not ever
702 // happen...
703 assert(!m_thread.IsValid() && "A valid thread has no frames.");
704 } else {
705 ResetCurrentInlinedDepth();
706 frame_sp = m_frames[original_idx];
707 }
708 }
709
710 return frame_sp;
711 }
712
713 StackFrameSP
GetFrameWithConcreteFrameIndex(uint32_t unwind_idx)714 StackFrameList::GetFrameWithConcreteFrameIndex(uint32_t unwind_idx) {
715 // First try assuming the unwind index is the same as the frame index. The
716 // unwind index is always greater than or equal to the frame index, so it is
717 // a good place to start. If we have inlined frames we might have 5 concrete
718 // frames (frame unwind indexes go from 0-4), but we might have 15 frames
719 // after we make all the inlined frames. Most of the time the unwind frame
720 // index (or the concrete frame index) is the same as the frame index.
721 uint32_t frame_idx = unwind_idx;
722 StackFrameSP frame_sp(GetFrameAtIndex(frame_idx));
723 while (frame_sp) {
724 if (frame_sp->GetFrameIndex() == unwind_idx)
725 break;
726 frame_sp = GetFrameAtIndex(++frame_idx);
727 }
728 return frame_sp;
729 }
730
CompareStackID(const StackFrameSP & stack_sp,const StackID & stack_id)731 static bool CompareStackID(const StackFrameSP &stack_sp,
732 const StackID &stack_id) {
733 return stack_sp->GetStackID() < stack_id;
734 }
735
GetFrameWithStackID(const StackID & stack_id)736 StackFrameSP StackFrameList::GetFrameWithStackID(const StackID &stack_id) {
737 StackFrameSP frame_sp;
738
739 if (stack_id.IsValid()) {
740 std::lock_guard<std::recursive_mutex> guard(m_mutex);
741 uint32_t frame_idx = 0;
742 // Do a binary search in case the stack frame is already in our cache
743 collection::const_iterator begin = m_frames.begin();
744 collection::const_iterator end = m_frames.end();
745 if (begin != end) {
746 collection::const_iterator pos =
747 std::lower_bound(begin, end, stack_id, CompareStackID);
748 if (pos != end) {
749 if ((*pos)->GetStackID() == stack_id)
750 return *pos;
751 }
752 }
753 do {
754 frame_sp = GetFrameAtIndex(frame_idx);
755 if (frame_sp && frame_sp->GetStackID() == stack_id)
756 break;
757 frame_idx++;
758 } while (frame_sp);
759 }
760 return frame_sp;
761 }
762
SetFrameAtIndex(uint32_t idx,StackFrameSP & frame_sp)763 bool StackFrameList::SetFrameAtIndex(uint32_t idx, StackFrameSP &frame_sp) {
764 if (idx >= m_frames.size())
765 m_frames.resize(idx + 1);
766 // Make sure allocation succeeded by checking bounds again
767 if (idx < m_frames.size()) {
768 m_frames[idx] = frame_sp;
769 return true;
770 }
771 return false; // resize failed, out of memory?
772 }
773
GetSelectedFrameIndex() const774 uint32_t StackFrameList::GetSelectedFrameIndex() const {
775 std::lock_guard<std::recursive_mutex> guard(m_mutex);
776 return m_selected_frame_idx;
777 }
778
SetSelectedFrame(lldb_private::StackFrame * frame)779 uint32_t StackFrameList::SetSelectedFrame(lldb_private::StackFrame *frame) {
780 std::lock_guard<std::recursive_mutex> guard(m_mutex);
781 const_iterator pos;
782 const_iterator begin = m_frames.begin();
783 const_iterator end = m_frames.end();
784 m_selected_frame_idx = 0;
785 for (pos = begin; pos != end; ++pos) {
786 if (pos->get() == frame) {
787 m_selected_frame_idx = std::distance(begin, pos);
788 uint32_t inlined_depth = GetCurrentInlinedDepth();
789 if (inlined_depth != UINT32_MAX)
790 m_selected_frame_idx -= inlined_depth;
791 break;
792 }
793 }
794 SetDefaultFileAndLineToSelectedFrame();
795 return m_selected_frame_idx;
796 }
797
SetSelectedFrameByIndex(uint32_t idx)798 bool StackFrameList::SetSelectedFrameByIndex(uint32_t idx) {
799 std::lock_guard<std::recursive_mutex> guard(m_mutex);
800 StackFrameSP frame_sp(GetFrameAtIndex(idx));
801 if (frame_sp) {
802 SetSelectedFrame(frame_sp.get());
803 return true;
804 } else
805 return false;
806 }
807
SetDefaultFileAndLineToSelectedFrame()808 void StackFrameList::SetDefaultFileAndLineToSelectedFrame() {
809 if (m_thread.GetID() ==
810 m_thread.GetProcess()->GetThreadList().GetSelectedThread()->GetID()) {
811 StackFrameSP frame_sp(GetFrameAtIndex(GetSelectedFrameIndex()));
812 if (frame_sp) {
813 SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextLineEntry);
814 if (sc.line_entry.file)
815 m_thread.CalculateTarget()->GetSourceManager().SetDefaultFileAndLine(
816 sc.line_entry.file, sc.line_entry.line);
817 }
818 }
819 }
820
821 // The thread has been run, reset the number stack frames to zero so we can
822 // determine how many frames we have lazily.
Clear()823 void StackFrameList::Clear() {
824 std::lock_guard<std::recursive_mutex> guard(m_mutex);
825 m_frames.clear();
826 m_concrete_frames_fetched = 0;
827 }
828
Merge(std::unique_ptr<StackFrameList> & curr_up,lldb::StackFrameListSP & prev_sp)829 void StackFrameList::Merge(std::unique_ptr<StackFrameList> &curr_up,
830 lldb::StackFrameListSP &prev_sp) {
831 std::unique_lock<std::recursive_mutex> current_lock, previous_lock;
832 if (curr_up)
833 current_lock = std::unique_lock<std::recursive_mutex>(curr_up->m_mutex);
834 if (prev_sp)
835 previous_lock = std::unique_lock<std::recursive_mutex>(prev_sp->m_mutex);
836
837 #if defined(DEBUG_STACK_FRAMES)
838 StreamFile s(stdout, false);
839 s.PutCString("\n\nStackFrameList::Merge():\nPrev:\n");
840 if (prev_sp)
841 prev_sp->Dump(&s);
842 else
843 s.PutCString("NULL");
844 s.PutCString("\nCurr:\n");
845 if (curr_up)
846 curr_up->Dump(&s);
847 else
848 s.PutCString("NULL");
849 s.EOL();
850 #endif
851
852 if (!curr_up || curr_up->GetNumFrames(false) == 0) {
853 #if defined(DEBUG_STACK_FRAMES)
854 s.PutCString("No current frames, leave previous frames alone...\n");
855 #endif
856 curr_up.release();
857 return;
858 }
859
860 if (!prev_sp || prev_sp->GetNumFrames(false) == 0) {
861 #if defined(DEBUG_STACK_FRAMES)
862 s.PutCString("No previous frames, so use current frames...\n");
863 #endif
864 // We either don't have any previous frames, or since we have more than one
865 // current frames it means we have all the frames and can safely replace
866 // our previous frames.
867 prev_sp.reset(curr_up.release());
868 return;
869 }
870
871 const uint32_t num_curr_frames = curr_up->GetNumFrames(false);
872
873 if (num_curr_frames > 1) {
874 #if defined(DEBUG_STACK_FRAMES)
875 s.PutCString(
876 "We have more than one current frame, so use current frames...\n");
877 #endif
878 // We have more than one current frames it means we have all the frames and
879 // can safely replace our previous frames.
880 prev_sp.reset(curr_up.release());
881
882 #if defined(DEBUG_STACK_FRAMES)
883 s.PutCString("\nMerged:\n");
884 prev_sp->Dump(&s);
885 #endif
886 return;
887 }
888
889 StackFrameSP prev_frame_zero_sp(prev_sp->GetFrameAtIndex(0));
890 StackFrameSP curr_frame_zero_sp(curr_up->GetFrameAtIndex(0));
891 StackID curr_stack_id(curr_frame_zero_sp->GetStackID());
892 StackID prev_stack_id(prev_frame_zero_sp->GetStackID());
893
894 #if defined(DEBUG_STACK_FRAMES)
895 const uint32_t num_prev_frames = prev_sp->GetNumFrames(false);
896 s.Printf("\n%u previous frames with one current frame\n", num_prev_frames);
897 #endif
898
899 // We have only a single current frame
900 // Our previous stack frames only had a single frame as well...
901 if (curr_stack_id == prev_stack_id) {
902 #if defined(DEBUG_STACK_FRAMES)
903 s.Printf("\nPrevious frame #0 is same as current frame #0, merge the "
904 "cached data\n");
905 #endif
906
907 curr_frame_zero_sp->UpdateCurrentFrameFromPreviousFrame(
908 *prev_frame_zero_sp);
909 // prev_frame_zero_sp->UpdatePreviousFrameFromCurrentFrame
910 // (*curr_frame_zero_sp);
911 // prev_sp->SetFrameAtIndex (0, prev_frame_zero_sp);
912 } else if (curr_stack_id < prev_stack_id) {
913 #if defined(DEBUG_STACK_FRAMES)
914 s.Printf("\nCurrent frame #0 has a stack ID that is less than the previous "
915 "frame #0, insert current frame zero in front of previous\n");
916 #endif
917 prev_sp->m_frames.insert(prev_sp->m_frames.begin(), curr_frame_zero_sp);
918 }
919
920 curr_up.release();
921
922 #if defined(DEBUG_STACK_FRAMES)
923 s.PutCString("\nMerged:\n");
924 prev_sp->Dump(&s);
925 #endif
926 }
927
928 lldb::StackFrameSP
GetStackFrameSPForStackFramePtr(StackFrame * stack_frame_ptr)929 StackFrameList::GetStackFrameSPForStackFramePtr(StackFrame *stack_frame_ptr) {
930 const_iterator pos;
931 const_iterator begin = m_frames.begin();
932 const_iterator end = m_frames.end();
933 lldb::StackFrameSP ret_sp;
934
935 for (pos = begin; pos != end; ++pos) {
936 if (pos->get() == stack_frame_ptr) {
937 ret_sp = (*pos);
938 break;
939 }
940 }
941 return ret_sp;
942 }
943
GetStatus(Stream & strm,uint32_t first_frame,uint32_t num_frames,bool show_frame_info,uint32_t num_frames_with_source,bool show_unique,const char * selected_frame_marker)944 size_t StackFrameList::GetStatus(Stream &strm, uint32_t first_frame,
945 uint32_t num_frames, bool show_frame_info,
946 uint32_t num_frames_with_source,
947 bool show_unique,
948 const char *selected_frame_marker) {
949 size_t num_frames_displayed = 0;
950
951 if (num_frames == 0)
952 return 0;
953
954 StackFrameSP frame_sp;
955 uint32_t frame_idx = 0;
956 uint32_t last_frame;
957
958 // Don't let the last frame wrap around...
959 if (num_frames == UINT32_MAX)
960 last_frame = UINT32_MAX;
961 else
962 last_frame = first_frame + num_frames;
963
964 StackFrameSP selected_frame_sp = m_thread.GetSelectedFrame();
965 const char *unselected_marker = nullptr;
966 std::string buffer;
967 if (selected_frame_marker) {
968 size_t len = strlen(selected_frame_marker);
969 buffer.insert(buffer.begin(), len, ' ');
970 unselected_marker = buffer.c_str();
971 }
972 const char *marker = nullptr;
973
974 for (frame_idx = first_frame; frame_idx < last_frame; ++frame_idx) {
975 frame_sp = GetFrameAtIndex(frame_idx);
976 if (!frame_sp)
977 break;
978
979 if (selected_frame_marker != nullptr) {
980 if (frame_sp == selected_frame_sp)
981 marker = selected_frame_marker;
982 else
983 marker = unselected_marker;
984 }
985
986 if (!frame_sp->GetStatus(strm, show_frame_info,
987 num_frames_with_source > (first_frame - frame_idx),
988 show_unique, marker))
989 break;
990 ++num_frames_displayed;
991 }
992
993 strm.IndentLess();
994 return num_frames_displayed;
995 }
996