1 //===-- ThreadPlanStepOut.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/ThreadPlanStepOut.h"
11
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Breakpoint/Breakpoint.h"
17 #include "lldb/lldb-private-log.h"
18 #include "lldb/Core/Log.h"
19 #include "lldb/Core/Value.h"
20 #include "lldb/Core/ValueObjectConstResult.h"
21 #include "lldb/Symbol/Block.h"
22 #include "lldb/Symbol/Function.h"
23 #include "lldb/Symbol/Type.h"
24 #include "lldb/Target/Process.h"
25 #include "lldb/Target/RegisterContext.h"
26 #include "lldb/Target/StopInfo.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/ThreadPlanStepOverRange.h"
29
30 using namespace lldb;
31 using namespace lldb_private;
32
33 //----------------------------------------------------------------------
34 // ThreadPlanStepOut: Step out of the current frame
35 //----------------------------------------------------------------------
ThreadPlanStepOut(Thread & thread,SymbolContext * context,bool first_insn,bool stop_others,Vote stop_vote,Vote run_vote,uint32_t frame_idx)36 ThreadPlanStepOut::ThreadPlanStepOut
37 (
38 Thread &thread,
39 SymbolContext *context,
40 bool first_insn,
41 bool stop_others,
42 Vote stop_vote,
43 Vote run_vote,
44 uint32_t frame_idx
45 ) :
46 ThreadPlan (ThreadPlan::eKindStepOut, "Step out", thread, stop_vote, run_vote),
47 m_step_from_context (context),
48 m_step_from_insn (LLDB_INVALID_ADDRESS),
49 m_return_bp_id (LLDB_INVALID_BREAK_ID),
50 m_return_addr (LLDB_INVALID_ADDRESS),
51 m_first_insn (first_insn),
52 m_stop_others (stop_others),
53 m_step_through_inline_plan_sp(),
54 m_step_out_plan_sp (),
55 m_immediate_step_from_function(NULL)
56
57 {
58 m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0);
59
60 StackFrameSP return_frame_sp (m_thread.GetStackFrameAtIndex(frame_idx + 1));
61 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (frame_idx));
62
63 if (!return_frame_sp || !immediate_return_from_sp)
64 return; // we can't do anything here. ValidatePlan() will return false.
65
66 m_step_out_to_id = return_frame_sp->GetStackID();
67 m_immediate_step_from_id = immediate_return_from_sp->GetStackID();
68
69 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
70
71 // If the frame directly below the one we are returning to is inlined, we have to be
72 // a little more careful. It is non-trivial to determine the real "return code address" for
73 // an inlined frame, so we have to work our way to that frame and then step out.
74 if (immediate_return_from_sp && immediate_return_from_sp->IsInlined())
75 {
76 if (frame_idx > 0)
77 {
78 // First queue a plan that gets us to this inlined frame, and when we get there we'll queue a second
79 // plan that walks us out of this frame.
80 m_step_out_plan_sp.reset (new ThreadPlanStepOut(m_thread,
81 NULL,
82 false,
83 stop_others,
84 eVoteNoOpinion,
85 eVoteNoOpinion,
86 frame_idx - 1));
87 }
88 else
89 {
90 // If we're already at the inlined frame we're stepping through, then just do that now.
91 QueueInlinedStepPlan(false);
92 }
93
94 }
95 else if (return_frame_sp)
96 {
97 // Find the return address and set a breakpoint there:
98 // FIXME - can we do this more securely if we know first_insn?
99
100 m_return_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(&m_thread.GetProcess()->GetTarget());
101
102 if (m_return_addr == LLDB_INVALID_ADDRESS)
103 return;
104
105 Breakpoint *return_bp = m_thread.CalculateTarget()->CreateBreakpoint (m_return_addr, true).get();
106 if (return_bp != NULL)
107 {
108 return_bp->SetThreadID(m_thread.GetID());
109 m_return_bp_id = return_bp->GetID();
110 return_bp->SetBreakpointKind ("step-out");
111 }
112
113 if (immediate_return_from_sp)
114 {
115 const SymbolContext &sc = immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction);
116 if (sc.function)
117 {
118 m_immediate_step_from_function = sc.function;
119 }
120 }
121 }
122
123 }
124
125 void
DidPush()126 ThreadPlanStepOut::DidPush()
127 {
128 if (m_step_out_plan_sp)
129 m_thread.QueueThreadPlan(m_step_out_plan_sp, false);
130 else if (m_step_through_inline_plan_sp)
131 m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false);
132 }
133
~ThreadPlanStepOut()134 ThreadPlanStepOut::~ThreadPlanStepOut ()
135 {
136 if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
137 m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id);
138 }
139
140 void
GetDescription(Stream * s,lldb::DescriptionLevel level)141 ThreadPlanStepOut::GetDescription (Stream *s, lldb::DescriptionLevel level)
142 {
143 if (level == lldb::eDescriptionLevelBrief)
144 s->Printf ("step out");
145 else
146 {
147 if (m_step_out_plan_sp)
148 s->Printf ("Stepping out to inlined frame so we can walk through it.");
149 else if (m_step_through_inline_plan_sp)
150 s->Printf ("Stepping out by stepping through inlined function.");
151 else
152 s->Printf ("Stepping out from address 0x%" PRIx64 " to return address 0x%" PRIx64 " using breakpoint site %d",
153 (uint64_t)m_step_from_insn,
154 (uint64_t)m_return_addr,
155 m_return_bp_id);
156 }
157 }
158
159 bool
ValidatePlan(Stream * error)160 ThreadPlanStepOut::ValidatePlan (Stream *error)
161 {
162 if (m_step_out_plan_sp)
163 return m_step_out_plan_sp->ValidatePlan (error);
164 else if (m_step_through_inline_plan_sp)
165 return m_step_through_inline_plan_sp->ValidatePlan (error);
166 else if (m_return_bp_id == LLDB_INVALID_BREAK_ID)
167 {
168 if (error)
169 error->PutCString("Could not create return address breakpoint.");
170 return false;
171 }
172 else
173 return true;
174 }
175
176 bool
DoPlanExplainsStop(Event * event_ptr)177 ThreadPlanStepOut::DoPlanExplainsStop (Event *event_ptr)
178 {
179 // If one of our child plans just finished, then we do explain the stop.
180 if (m_step_out_plan_sp)
181 {
182 if (m_step_out_plan_sp->MischiefManaged())
183 {
184 // If this one is done, then we are all done.
185 CalculateReturnValue();
186 SetPlanComplete();
187 return true;
188 }
189 else
190 return false;
191 }
192 else if (m_step_through_inline_plan_sp)
193 {
194 if (m_step_through_inline_plan_sp->MischiefManaged())
195 return true;
196 else
197 return false;
198 }
199
200 // We don't explain signals or breakpoints (breakpoints that handle stepping in or
201 // out will be handled by a child plan.
202
203 StopInfoSP stop_info_sp = GetPrivateStopInfo ();
204 if (stop_info_sp)
205 {
206 StopReason reason = stop_info_sp->GetStopReason();
207 switch (reason)
208 {
209 case eStopReasonBreakpoint:
210 {
211 // If this is OUR breakpoint, we're fine, otherwise we don't know why this happened...
212 BreakpointSiteSP site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (stop_info_sp->GetValue()));
213 if (site_sp && site_sp->IsBreakpointAtThisSite (m_return_bp_id))
214 {
215 bool done;
216
217 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
218
219 if (m_step_out_to_id == frame_zero_id)
220 done = true;
221 else if (m_step_out_to_id < frame_zero_id)
222 {
223 // Either we stepped past the breakpoint, or the stack ID calculation
224 // was incorrect and we should probably stop.
225 done = true;
226 }
227 else
228 {
229 if (m_immediate_step_from_id < frame_zero_id)
230 done = true;
231 else
232 done = false;
233 }
234
235 if (done)
236 {
237 CalculateReturnValue();
238 SetPlanComplete();
239 }
240
241 // If there was only one owner, then we're done. But if we also hit some
242 // user breakpoint on our way out, we should mark ourselves as done, but
243 // also not claim to explain the stop, since it is more important to report
244 // the user breakpoint than the step out completion.
245
246 if (site_sp->GetNumberOfOwners() == 1)
247 return true;
248
249 }
250 return false;
251 }
252 case eStopReasonWatchpoint:
253 case eStopReasonSignal:
254 case eStopReasonException:
255 case eStopReasonExec:
256 case eStopReasonThreadExiting:
257 return false;
258
259 default:
260 return true;
261 }
262 }
263 return true;
264 }
265
266 bool
ShouldStop(Event * event_ptr)267 ThreadPlanStepOut::ShouldStop (Event *event_ptr)
268 {
269 if (IsPlanComplete())
270 return true;
271
272 bool done;
273
274 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
275 if (frame_zero_id < m_step_out_to_id)
276 done = false;
277 else
278 done = true;
279
280 if (done)
281 {
282 CalculateReturnValue();
283 SetPlanComplete();
284 return true;
285 }
286 else
287 {
288 if (m_step_out_plan_sp)
289 {
290 if (m_step_out_plan_sp->MischiefManaged())
291 {
292 // Now step through the inlined stack we are in:
293 if (QueueInlinedStepPlan(true))
294 {
295 return false;
296 }
297 else
298 {
299 CalculateReturnValue();
300 SetPlanComplete ();
301 return true;
302 }
303 }
304 else
305 return m_step_out_plan_sp->ShouldStop(event_ptr);
306 }
307 else if (m_step_through_inline_plan_sp)
308 {
309 if (m_step_through_inline_plan_sp->MischiefManaged())
310 {
311 // We don't calculate the return value here because we don't know how to.
312 // But in case we had a return value sitting around from our process in
313 // getting here, let's clear it out.
314 m_return_valobj_sp.reset();
315 SetPlanComplete();
316 return true;
317 }
318 else
319 return m_step_through_inline_plan_sp->ShouldStop(event_ptr);
320 }
321 else
322 return false;
323 }
324 }
325
326 bool
StopOthers()327 ThreadPlanStepOut::StopOthers ()
328 {
329 return m_stop_others;
330 }
331
332 StateType
GetPlanRunState()333 ThreadPlanStepOut::GetPlanRunState ()
334 {
335 return eStateRunning;
336 }
337
338 bool
DoWillResume(StateType resume_state,bool current_plan)339 ThreadPlanStepOut::DoWillResume (StateType resume_state, bool current_plan)
340 {
341 if (m_step_out_plan_sp || m_step_through_inline_plan_sp)
342 return true;
343
344 if (m_return_bp_id == LLDB_INVALID_BREAK_ID)
345 return false;
346
347 if (current_plan)
348 {
349 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
350 if (return_bp != NULL)
351 return_bp->SetEnabled (true);
352 }
353 return true;
354 }
355
356 bool
WillStop()357 ThreadPlanStepOut::WillStop ()
358 {
359 if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
360 {
361 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
362 if (return_bp != NULL)
363 return_bp->SetEnabled (false);
364 }
365
366 return true;
367 }
368
369 bool
MischiefManaged()370 ThreadPlanStepOut::MischiefManaged ()
371 {
372 if (IsPlanComplete())
373 {
374 // Did I reach my breakpoint? If so I'm done.
375 //
376 // I also check the stack depth, since if we've blown past the breakpoint for some
377 // reason and we're now stopping for some other reason altogether, then we're done
378 // with this step out operation.
379
380 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
381 if (log)
382 log->Printf("Completed step out plan.");
383 if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
384 {
385 m_thread.CalculateTarget()->RemoveBreakpointByID (m_return_bp_id);
386 m_return_bp_id = LLDB_INVALID_BREAK_ID;
387 }
388
389 ThreadPlan::MischiefManaged ();
390 return true;
391 }
392 else
393 {
394 return false;
395 }
396 }
397
398 bool
QueueInlinedStepPlan(bool queue_now)399 ThreadPlanStepOut::QueueInlinedStepPlan (bool queue_now)
400 {
401 // Now figure out the range of this inlined block, and set up a "step through range"
402 // plan for that. If we've been provided with a context, then use the block in that
403 // context.
404 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (0));
405 if (!immediate_return_from_sp)
406 return false;
407
408 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
409 if (log)
410 {
411 StreamString s;
412 immediate_return_from_sp->Dump(&s, true, false);
413 log->Printf("Queuing inlined frame to step past: %s.", s.GetData());
414 }
415
416 Block *from_block = immediate_return_from_sp->GetFrameBlock();
417 if (from_block)
418 {
419 Block *inlined_block = from_block->GetContainingInlinedBlock();
420 if (inlined_block)
421 {
422 size_t num_ranges = inlined_block->GetNumRanges();
423 AddressRange inline_range;
424 if (inlined_block->GetRangeAtIndex(0, inline_range))
425 {
426 SymbolContext inlined_sc;
427 inlined_block->CalculateSymbolContext(&inlined_sc);
428 inlined_sc.target_sp = GetTarget().shared_from_this();
429 RunMode run_mode = m_stop_others ? lldb::eOnlyThisThread : lldb::eAllThreads;
430 ThreadPlanStepOverRange *step_through_inline_plan_ptr = new ThreadPlanStepOverRange(m_thread,
431 inline_range,
432 inlined_sc,
433 run_mode);
434 step_through_inline_plan_ptr->SetOkayToDiscard(true);
435 StreamString errors;
436 if (!step_through_inline_plan_ptr->ValidatePlan(&errors))
437 {
438 //FIXME: Log this failure.
439 delete step_through_inline_plan_ptr;
440 return false;
441 }
442
443 for (size_t i = 1; i < num_ranges; i++)
444 {
445 if (inlined_block->GetRangeAtIndex (i, inline_range))
446 step_through_inline_plan_ptr->AddRange (inline_range);
447 }
448 m_step_through_inline_plan_sp.reset (step_through_inline_plan_ptr);
449 if (queue_now)
450 m_thread.QueueThreadPlan (m_step_through_inline_plan_sp, false);
451 return true;
452 }
453 }
454 }
455
456 return false;
457 }
458
459 void
CalculateReturnValue()460 ThreadPlanStepOut::CalculateReturnValue ()
461 {
462 if (m_return_valobj_sp)
463 return;
464
465 if (m_immediate_step_from_function != NULL)
466 {
467 ClangASTType return_clang_type = m_immediate_step_from_function->GetClangType().GetFunctionReturnType();
468 if (return_clang_type)
469 {
470 lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI();
471 if (abi_sp)
472 m_return_valobj_sp = abi_sp->GetReturnValueObject(m_thread, return_clang_type);
473 }
474 }
475 }
476
477 bool
IsPlanStale()478 ThreadPlanStepOut::IsPlanStale()
479 {
480 // If we are still lower on the stack than the frame we are returning to, then
481 // there's something for us to do. Otherwise, we're stale.
482
483 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
484 if (frame_zero_id < m_step_out_to_id)
485 return false;
486 else
487 return true;
488 }
489
490