1 //===-- StopInfo.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/StopInfo.h"
11 
12 // C Includes
13 // C++ Includes
14 #include <string>
15 
16 // Other libraries and framework includes
17 // Project includes
18 #include "lldb/Core/Log.h"
19 #include "lldb/Breakpoint/Breakpoint.h"
20 #include "lldb/Breakpoint/BreakpointLocation.h"
21 #include "lldb/Breakpoint/StoppointCallbackContext.h"
22 #include "lldb/Breakpoint/Watchpoint.h"
23 #include "lldb/Core/Debugger.h"
24 #include "lldb/Core/StreamString.h"
25 #include "lldb/Expression/ClangUserExpression.h"
26 #include "lldb/Target/Target.h"
27 #include "lldb/Target/Thread.h"
28 #include "lldb/Target/ThreadPlan.h"
29 #include "lldb/Target/Process.h"
30 #include "lldb/Target/UnixSignals.h"
31 
32 using namespace lldb;
33 using namespace lldb_private;
34 
35 StopInfo::StopInfo (Thread &thread, uint64_t value) :
36     m_thread (thread),
37     m_stop_id (thread.GetProcess()->GetStopID()),
38     m_resume_id (thread.GetProcess()->GetResumeID()),
39     m_value (value)
40 {
41 }
42 
43 bool
44 StopInfo::IsValid () const
45 {
46     return m_thread.GetProcess()->GetStopID() == m_stop_id;
47 }
48 
49 void
50 StopInfo::MakeStopInfoValid ()
51 {
52     m_stop_id = m_thread.GetProcess()->GetStopID();
53     m_resume_id = m_thread.GetProcess()->GetResumeID();
54 }
55 
56 bool
57 StopInfo::HasTargetRunSinceMe ()
58 {
59     lldb::StateType ret_type = m_thread.GetProcess()->GetPrivateState();
60     if (ret_type == eStateRunning)
61     {
62         return true;
63     }
64     else if (ret_type == eStateStopped)
65     {
66         // This is a little tricky.  We want to count "run and stopped again before you could
67         // ask this question as a "TRUE" answer to HasTargetRunSinceMe.  But we don't want to
68         // include any running of the target done for expressions.  So we track both resumes,
69         // and resumes caused by expressions, and check if there are any resumes NOT caused
70         // by expressions.
71 
72         uint32_t curr_resume_id = m_thread.GetProcess()->GetResumeID();
73         uint32_t last_user_expression_id = m_thread.GetProcess()->GetLastUserExpressionResumeID ();
74         if (curr_resume_id == m_resume_id)
75         {
76             return false;
77         }
78         else if (curr_resume_id > last_user_expression_id)
79         {
80             return true;
81         }
82     }
83     return false;
84 }
85 
86 //----------------------------------------------------------------------
87 // StopInfoBreakpoint
88 //----------------------------------------------------------------------
89 
90 namespace lldb_private
91 {
92 class StopInfoBreakpoint : public StopInfo
93 {
94 public:
95 
96     StopInfoBreakpoint (Thread &thread, break_id_t break_id) :
97         StopInfo (thread, break_id),
98         m_description(),
99         m_should_stop (false),
100         m_should_stop_is_valid (false),
101         m_should_perform_action (true),
102         m_address (LLDB_INVALID_ADDRESS),
103         m_break_id(LLDB_INVALID_BREAK_ID),
104         m_was_one_shot (false)
105     {
106         StoreBPInfo();
107     }
108 
109     StopInfoBreakpoint (Thread &thread, break_id_t break_id, bool should_stop) :
110         StopInfo (thread, break_id),
111         m_description(),
112         m_should_stop (should_stop),
113         m_should_stop_is_valid (true),
114         m_should_perform_action (true),
115         m_address (LLDB_INVALID_ADDRESS),
116         m_break_id(LLDB_INVALID_BREAK_ID),
117         m_was_one_shot (false)
118     {
119         StoreBPInfo();
120     }
121 
122     void StoreBPInfo ()
123     {
124         BreakpointSiteSP bp_site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (m_value));
125         if (bp_site_sp)
126         {
127             if (bp_site_sp->GetNumberOfOwners() == 1)
128             {
129                 BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(0);
130                 if (bp_loc_sp)
131                 {
132                     m_break_id = bp_loc_sp->GetBreakpoint().GetID();
133                     m_was_one_shot = bp_loc_sp->GetBreakpoint().IsOneShot();
134                 }
135             }
136             m_address = bp_site_sp->GetLoadAddress();
137         }
138     }
139 
140     virtual ~StopInfoBreakpoint ()
141     {
142     }
143 
144     virtual StopReason
145     GetStopReason () const
146     {
147         return eStopReasonBreakpoint;
148     }
149 
150     virtual bool
151     ShouldStopSynchronous (Event *event_ptr)
152     {
153         if (!m_should_stop_is_valid)
154         {
155             // Only check once if we should stop at a breakpoint
156             BreakpointSiteSP bp_site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (m_value));
157             if (bp_site_sp)
158             {
159                 ExecutionContext exe_ctx (m_thread.GetStackFrameAtIndex(0));
160                 StoppointCallbackContext context (event_ptr, exe_ctx, true);
161                 m_should_stop = bp_site_sp->ShouldStop (&context);
162             }
163             else
164             {
165                 LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
166 
167                 if (log)
168                     log->Printf ("Process::%s could not find breakpoint site id: %lld...", __FUNCTION__, m_value);
169 
170                 m_should_stop = true;
171             }
172             m_should_stop_is_valid = true;
173         }
174         return m_should_stop;
175     }
176 
177     bool
178     ShouldStop (Event *event_ptr)
179     {
180         // This just reports the work done by PerformAction or the synchronous stop.  It should
181         // only ever get called after they have had a chance to run.
182         assert (m_should_stop_is_valid);
183         return m_should_stop;
184     }
185 
186     virtual void
187     PerformAction (Event *event_ptr)
188     {
189         if (!m_should_perform_action)
190             return;
191         m_should_perform_action = false;
192 
193         LogSP log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_BREAKPOINTS);
194 
195         BreakpointSiteSP bp_site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (m_value));
196 
197         if (bp_site_sp)
198         {
199             size_t num_owners = bp_site_sp->GetNumberOfOwners();
200 
201             if (num_owners == 0)
202             {
203                 m_should_stop = true;
204             }
205             else
206             {
207                 // We go through each location, and test first its condition.  If the condition says to stop,
208                 // then we run the callback for that location.  If that callback says to stop as well, then
209                 // we set m_should_stop to true; we are going to stop.
210                 // But we still want to give all the breakpoints whose conditions say we are going to stop a
211                 // chance to run their callbacks.
212                 // Of course if any callback restarts the target by putting "continue" in the callback, then
213                 // we're going to restart, without running the rest of the callbacks.  And in this case we will
214                 // end up not stopping even if another location said we should stop.  But that's better than not
215                 // running all the callbacks.
216 
217                 m_should_stop = false;
218 
219                 ExecutionContext exe_ctx (m_thread.GetStackFrameAtIndex(0));
220                 StoppointCallbackContext context (event_ptr, exe_ctx, false);
221 
222                 for (size_t j = 0; j < num_owners; j++)
223                 {
224                     lldb::BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(j);
225 
226                     // First run the condition for the breakpoint.  If that says we should stop, then we'll run
227                     // the callback for the breakpoint.  If the callback says we shouldn't stop that will win.
228 
229                     bool condition_says_stop = true;
230                     if (bp_loc_sp->GetConditionText() != NULL)
231                     {
232                         // We need to make sure the user sees any parse errors in their condition, so we'll hook the
233                         // constructor errors up to the debugger's Async I/O.
234 
235                         ValueObjectSP result_valobj_sp;
236 
237                         ExecutionResults result_code;
238                         ValueObjectSP result_value_sp;
239                         const bool discard_on_error = true;
240                         Error error;
241                         result_code = ClangUserExpression::EvaluateWithError (exe_ctx,
242                                                                               eExecutionPolicyOnlyWhenNeeded,
243                                                                               lldb::eLanguageTypeUnknown,
244                                                                               ClangUserExpression::eResultTypeAny,
245                                                                               discard_on_error,
246                                                                               bp_loc_sp->GetConditionText(),
247                                                                               NULL,
248                                                                               result_value_sp,
249                                                                               error,
250                                                                               true,
251                                                                               ClangUserExpression::kDefaultTimeout);
252                         if (result_code == eExecutionCompleted)
253                         {
254                             if (result_value_sp)
255                             {
256                                 Scalar scalar_value;
257                                 if (result_value_sp->ResolveValue (scalar_value))
258                                 {
259                                     if (scalar_value.ULongLong(1) == 0)
260                                         condition_says_stop = false;
261                                     else
262                                         condition_says_stop = true;
263                                     if (log)
264                                         log->Printf("Condition successfully evaluated, result is %s.\n",
265                                                     m_should_stop ? "true" : "false");
266                                 }
267                                 else
268                                 {
269                                     condition_says_stop = true;
270                                     if (log)
271                                         log->Printf("Failed to get an integer result from the expression.");
272                                 }
273                             }
274                         }
275                         else
276                         {
277                             Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
278                             StreamSP error_sp = debugger.GetAsyncErrorStream ();
279                             error_sp->Printf ("Stopped due to an error evaluating condition of breakpoint ");
280                             bp_loc_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
281                             error_sp->Printf (": \"%s\"",
282                                               bp_loc_sp->GetConditionText());
283                             error_sp->EOL();
284                             const char *err_str = error.AsCString("<Unknown Error>");
285                             if (log)
286                                 log->Printf("Error evaluating condition: \"%s\"\n", err_str);
287 
288                             error_sp->PutCString (err_str);
289                             error_sp->EOL();
290                             error_sp->Flush();
291                             // If the condition fails to be parsed or run, we should stop.
292                             condition_says_stop = true;
293                         }
294                     }
295 
296                     // If this location's condition says we should aren't going to stop,
297                     // then don't run the callback for this location.
298                     if (!condition_says_stop)
299                         continue;
300 
301                     bool callback_says_stop;
302 
303                     // FIXME: For now the callbacks have to run in async mode - the first time we restart we need
304                     // to get out of there.  So set it here.
305                     // When we figure out how to nest breakpoint hits then this will change.
306 
307                     Debugger &debugger = m_thread.CalculateTarget()->GetDebugger();
308                     bool old_async = debugger.GetAsyncExecution();
309                     debugger.SetAsyncExecution (true);
310 
311                     callback_says_stop = bp_loc_sp->InvokeCallback (&context);
312 
313                     debugger.SetAsyncExecution (old_async);
314 
315                     if (callback_says_stop)
316                         m_should_stop = true;
317 
318                     // If we are going to stop for this breakpoint, then remove the breakpoint.
319                     if (callback_says_stop && bp_loc_sp && bp_loc_sp->GetBreakpoint().IsOneShot())
320                     {
321                         m_thread.GetProcess()->GetTarget().RemoveBreakpointByID (bp_loc_sp->GetBreakpoint().GetID());
322                     }
323 
324                     // Also make sure that the callback hasn't continued the target.
325                     // If it did, when we'll set m_should_start to false and get out of here.
326                     if (HasTargetRunSinceMe ())
327                     {
328                         m_should_stop = false;
329                         break;
330                     }
331                 }
332             }
333             // We've figured out what this stop wants to do, so mark it as valid so we don't compute it again.
334             m_should_stop_is_valid = true;
335 
336         }
337         else
338         {
339             m_should_stop = true;
340             m_should_stop_is_valid = true;
341             LogSP log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
342 
343             if (log_process)
344                 log_process->Printf ("Process::%s could not find breakpoint site id: %lld...", __FUNCTION__, m_value);
345         }
346         if (log)
347             log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
348     }
349 
350     virtual bool
351     ShouldNotify (Event *event_ptr)
352     {
353         BreakpointSiteSP bp_site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (m_value));
354         if (bp_site_sp)
355         {
356             bool all_internal = true;
357 
358             for (uint32_t i = 0; i < bp_site_sp->GetNumberOfOwners(); i++)
359             {
360                 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal())
361                 {
362                     all_internal = false;
363                     break;
364                 }
365             }
366             return all_internal == false;
367         }
368         return true;
369     }
370 
371     virtual const char *
372     GetDescription ()
373     {
374         if (m_description.empty())
375         {
376             BreakpointSiteSP bp_site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (m_value));
377             if (bp_site_sp)
378             {
379                 StreamString strm;
380                 strm.Printf("breakpoint ");
381                 bp_site_sp->GetDescription(&strm, eDescriptionLevelBrief);
382                 m_description.swap (strm.GetString());
383             }
384             else
385             {
386                 StreamString strm;
387                 if (m_break_id != LLDB_INVALID_BREAK_ID)
388                 {
389                     if (m_was_one_shot)
390                         strm.Printf ("one-shot breakpoint %d", m_break_id);
391                     else
392                         strm.Printf ("breakpoint %d which has been deleted.", m_break_id);
393                 }
394                 else if (m_address == LLDB_INVALID_ADDRESS)
395                     strm.Printf("breakpoint site %lli which has been deleted - unknown address", m_value);
396                 else
397                     strm.Printf("breakpoint site %lli which has been deleted - was at 0x%llx", m_value, m_address);
398 
399                 m_description.swap (strm.GetString());
400             }
401         }
402         return m_description.c_str();
403     }
404 
405 private:
406     std::string m_description;
407     bool m_should_stop;
408     bool m_should_stop_is_valid;
409     bool m_should_perform_action; // Since we are trying to preserve the "state" of the system even if we run functions
410                                   // etc. behind the users backs, we need to make sure we only REALLY perform the action once.
411     lldb::addr_t m_address;       // We use this to capture the breakpoint site address when we create the StopInfo,
412                                   // in case somebody deletes it between the time the StopInfo is made and the
413                                   // description is asked for.
414     lldb::break_id_t m_break_id;
415     bool m_was_one_shot;
416 };
417 
418 
419 //----------------------------------------------------------------------
420 // StopInfoWatchpoint
421 //----------------------------------------------------------------------
422 
423 class StopInfoWatchpoint : public StopInfo
424 {
425 public:
426 
427     StopInfoWatchpoint (Thread &thread, break_id_t watch_id) :
428         StopInfo(thread, watch_id),
429         m_description(),
430         m_should_stop(false),
431         m_should_stop_is_valid(false)
432     {
433     }
434 
435     virtual ~StopInfoWatchpoint ()
436     {
437     }
438 
439     virtual StopReason
440     GetStopReason () const
441     {
442         return eStopReasonWatchpoint;
443     }
444 
445     virtual bool
446     ShouldStop (Event *event_ptr)
447     {
448         // ShouldStop() method is idempotent and should not affect hit count.
449         // See Process::RunPrivateStateThread()->Process()->HandlePrivateEvent()
450         // -->Process()::ShouldBroadcastEvent()->ThreadList::ShouldStop()->
451         // Thread::ShouldStop()->ThreadPlanBase::ShouldStop()->
452         // StopInfoWatchpoint::ShouldStop() and
453         // Event::DoOnRemoval()->Process::ProcessEventData::DoOnRemoval()->
454         // StopInfoWatchpoint::PerformAction().
455         if (m_should_stop_is_valid)
456             return m_should_stop;
457 
458         WatchpointSP wp_sp =
459             m_thread.CalculateTarget()->GetWatchpointList().FindByID(GetValue());
460         if (wp_sp)
461         {
462             // Check if we should stop at a watchpoint.
463             ExecutionContext exe_ctx (m_thread.GetStackFrameAtIndex(0));
464             StoppointCallbackContext context (event_ptr, exe_ctx, true);
465             m_should_stop = wp_sp->ShouldStop (&context);
466         }
467         else
468         {
469             LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
470 
471             if (log)
472                 log->Printf ("Process::%s could not find watchpoint location id: %lld...",
473                              __FUNCTION__, GetValue());
474 
475             m_should_stop = true;
476         }
477         m_should_stop_is_valid = true;
478         return m_should_stop;
479     }
480 
481     // Make sure watchpoint is properly disabled and subsequently enabled while performing watchpoint actions.
482     class WatchpointSentry {
483     public:
484         WatchpointSentry(Process *p, Watchpoint *w):
485             process(p),
486             watchpoint(w)
487         {
488             if (process && watchpoint)
489             {
490                 watchpoint->TurnOnEphemeralMode();
491                 process->DisableWatchpoint(watchpoint);
492             }
493         }
494         ~WatchpointSentry()
495         {
496             if (process && watchpoint)
497             {
498                 if (!watchpoint->IsDisabledDuringEphemeralMode())
499                     process->EnableWatchpoint(watchpoint);
500                 watchpoint->TurnOffEphemeralMode();
501             }
502         }
503     private:
504         Process *process;
505         Watchpoint *watchpoint;
506     };
507 
508     // Perform any action that is associated with this stop.  This is done as the
509     // Event is removed from the event queue.
510     virtual void
511     PerformAction (Event *event_ptr)
512     {
513         LogSP log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_WATCHPOINTS);
514         // We're going to calculate if we should stop or not in some way during the course of
515         // this code.  Also by default we're going to stop, so set that here.
516         m_should_stop = true;
517 
518         WatchpointSP wp_sp =
519             m_thread.CalculateTarget()->GetWatchpointList().FindByID(GetValue());
520         if (wp_sp)
521         {
522             ExecutionContext exe_ctx (m_thread.GetStackFrameAtIndex(0));
523             Process* process = exe_ctx.GetProcessPtr();
524 
525             // This sentry object makes sure the current watchpoint is disabled while performing watchpoint actions,
526             // and it is then enabled after we are finished.
527             WatchpointSentry sentry(process, wp_sp.get());
528 
529             {
530                 // check if this process is running on an architecture where watchpoints trigger
531 				// before the associated instruction runs. if so, disable the WP, single-step and then
532 				// re-enable the watchpoint
533                 if (process)
534                 {
535                     uint32_t num; bool wp_triggers_after;
536                     if (process->GetWatchpointSupportInfo(num, wp_triggers_after).Success())
537                     {
538                         if (!wp_triggers_after)
539                         {
540                             ThreadPlan *new_plan = m_thread.QueueThreadPlanForStepSingleInstruction(false, // step-over
541                                                                                                     false, // abort_other_plans
542                                                                                                     true); // stop_other_threads
543                             new_plan->SetIsMasterPlan (true);
544                             new_plan->SetOkayToDiscard (false);
545                             process->GetThreadList().SetSelectedThreadByID (m_thread.GetID());
546                             process->Resume ();
547                             process->WaitForProcessToStop (NULL);
548                             process->GetThreadList().SetSelectedThreadByID (m_thread.GetID());
549                             MakeStopInfoValid(); // make sure we do not fail to stop because of the single-step taken above
550                         }
551                     }
552                 }
553             }
554 
555             if (m_should_stop && wp_sp->GetConditionText() != NULL)
556             {
557                 // We need to make sure the user sees any parse errors in their condition, so we'll hook the
558                 // constructor errors up to the debugger's Async I/O.
559                 ExecutionResults result_code;
560                 ValueObjectSP result_value_sp;
561                 const bool discard_on_error = true;
562                 Error error;
563                 result_code = ClangUserExpression::EvaluateWithError (exe_ctx,
564                                                                       eExecutionPolicyOnlyWhenNeeded,
565                                                                       lldb::eLanguageTypeUnknown,
566                                                                       ClangUserExpression::eResultTypeAny,
567                                                                       discard_on_error,
568                                                                       wp_sp->GetConditionText(),
569                                                                       NULL,
570                                                                       result_value_sp,
571                                                                       error,
572                                                                       true,
573                                                                       ClangUserExpression::kDefaultTimeout);
574                 if (result_code == eExecutionCompleted)
575                 {
576                     if (result_value_sp)
577                     {
578                         Scalar scalar_value;
579                         if (result_value_sp->ResolveValue (scalar_value))
580                         {
581                             if (scalar_value.ULongLong(1) == 0)
582                             {
583                                 // We have been vetoed.  This takes precedence over querying
584                                 // the watchpoint whether it should stop (aka ignore count and
585                                 // friends).  See also StopInfoWatchpoint::ShouldStop() as well
586                                 // as Process::ProcessEventData::DoOnRemoval().
587                                 m_should_stop = false;
588                             }
589                             else
590                                 m_should_stop = true;
591                             if (log)
592                                 log->Printf("Condition successfully evaluated, result is %s.\n",
593                                             m_should_stop ? "true" : "false");
594                         }
595                         else
596                         {
597                             m_should_stop = true;
598                             if (log)
599                                 log->Printf("Failed to get an integer result from the expression.");
600                         }
601                     }
602                 }
603                 else
604                 {
605                     Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
606                     StreamSP error_sp = debugger.GetAsyncErrorStream ();
607                     error_sp->Printf ("Stopped due to an error evaluating condition of watchpoint ");
608                     wp_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
609                     error_sp->Printf (": \"%s\"",
610                                       wp_sp->GetConditionText());
611                     error_sp->EOL();
612                     const char *err_str = error.AsCString("<Unknown Error>");
613                     if (log)
614                         log->Printf("Error evaluating condition: \"%s\"\n", err_str);
615 
616                     error_sp->PutCString (err_str);
617                     error_sp->EOL();
618                     error_sp->Flush();
619                     // If the condition fails to be parsed or run, we should stop.
620                     m_should_stop = true;
621                 }
622             }
623 
624             // If the condition says to stop, we run the callback to further decide whether to stop.
625             if (m_should_stop)
626             {
627                 StoppointCallbackContext context (event_ptr, exe_ctx, false);
628                 bool stop_requested = wp_sp->InvokeCallback (&context);
629                 // Also make sure that the callback hasn't continued the target.
630                 // If it did, when we'll set m_should_stop to false and get out of here.
631                 if (HasTargetRunSinceMe ())
632                     m_should_stop = false;
633 
634                 if (m_should_stop && !stop_requested)
635                 {
636                     // We have been vetoed by the callback mechanism.
637                     m_should_stop = false;
638                 }
639             }
640             // Finally, if we are going to stop, print out the new & old values:
641             if (m_should_stop)
642             {
643                 wp_sp->CaptureWatchedValue(exe_ctx);
644 
645                 Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
646                 StreamSP output_sp = debugger.GetAsyncOutputStream ();
647                 wp_sp->DumpSnapshots(output_sp.get());
648                 output_sp->EOL();
649                 output_sp->Flush();
650             }
651 
652         }
653         else
654         {
655             LogSP log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
656 
657             if (log_process)
658                 log_process->Printf ("Process::%s could not find watchpoint id: %lld...", __FUNCTION__, m_value);
659         }
660         if (log)
661             log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
662 
663     }
664 
665     virtual const char *
666     GetDescription ()
667     {
668         if (m_description.empty())
669         {
670             StreamString strm;
671             strm.Printf("watchpoint %lli", m_value);
672             m_description.swap (strm.GetString());
673         }
674         return m_description.c_str();
675     }
676 
677 private:
678     std::string m_description;
679     bool m_should_stop;
680     bool m_should_stop_is_valid;
681 };
682 
683 
684 
685 //----------------------------------------------------------------------
686 // StopInfoUnixSignal
687 //----------------------------------------------------------------------
688 
689 class StopInfoUnixSignal : public StopInfo
690 {
691 public:
692 
693     StopInfoUnixSignal (Thread &thread, int signo) :
694         StopInfo (thread, signo)
695     {
696     }
697 
698     virtual ~StopInfoUnixSignal ()
699     {
700     }
701 
702 
703     virtual StopReason
704     GetStopReason () const
705     {
706         return eStopReasonSignal;
707     }
708 
709     virtual bool
710     ShouldStop (Event *event_ptr)
711     {
712         return m_thread.GetProcess()->GetUnixSignals().GetShouldStop (m_value);
713     }
714 
715 
716     // If should stop returns false, check if we should notify of this event
717     virtual bool
718     ShouldNotify (Event *event_ptr)
719     {
720         return m_thread.GetProcess()->GetUnixSignals().GetShouldNotify (m_value);
721     }
722 
723 
724     virtual void
725     WillResume (lldb::StateType resume_state)
726     {
727         if (m_thread.GetProcess()->GetUnixSignals().GetShouldSuppress(m_value) == false)
728             m_thread.SetResumeSignal(m_value);
729     }
730 
731     virtual const char *
732     GetDescription ()
733     {
734         if (m_description.empty())
735         {
736             StreamString strm;
737             const char *signal_name = m_thread.GetProcess()->GetUnixSignals().GetSignalAsCString (m_value);
738             if (signal_name)
739                 strm.Printf("signal %s", signal_name);
740             else
741                 strm.Printf("signal %lli", m_value);
742             m_description.swap (strm.GetString());
743         }
744         return m_description.c_str();
745     }
746 };
747 
748 //----------------------------------------------------------------------
749 // StopInfoTrace
750 //----------------------------------------------------------------------
751 
752 class StopInfoTrace : public StopInfo
753 {
754 public:
755 
756     StopInfoTrace (Thread &thread) :
757         StopInfo (thread, LLDB_INVALID_UID)
758     {
759     }
760 
761     virtual ~StopInfoTrace ()
762     {
763     }
764 
765     virtual StopReason
766     GetStopReason () const
767     {
768         return eStopReasonTrace;
769     }
770 
771     virtual const char *
772     GetDescription ()
773     {
774         if (m_description.empty())
775         return "trace";
776         else
777             return m_description.c_str();
778     }
779 };
780 
781 
782 //----------------------------------------------------------------------
783 // StopInfoException
784 //----------------------------------------------------------------------
785 
786 class StopInfoException : public StopInfo
787 {
788 public:
789 
790     StopInfoException (Thread &thread, const char *description) :
791         StopInfo (thread, LLDB_INVALID_UID)
792     {
793         if (description)
794             SetDescription (description);
795     }
796 
797     virtual
798     ~StopInfoException ()
799     {
800     }
801 
802     virtual StopReason
803     GetStopReason () const
804     {
805         return eStopReasonException;
806     }
807 
808     virtual const char *
809     GetDescription ()
810     {
811         if (m_description.empty())
812             return "exception";
813         else
814             return m_description.c_str();
815     }
816 };
817 
818 
819 //----------------------------------------------------------------------
820 // StopInfoThreadPlan
821 //----------------------------------------------------------------------
822 
823 class StopInfoThreadPlan : public StopInfo
824 {
825 public:
826 
827     StopInfoThreadPlan (ThreadPlanSP &plan_sp, ValueObjectSP &return_valobj_sp) :
828         StopInfo (plan_sp->GetThread(), LLDB_INVALID_UID),
829         m_plan_sp (plan_sp),
830         m_return_valobj_sp (return_valobj_sp)
831     {
832     }
833 
834     virtual ~StopInfoThreadPlan ()
835     {
836     }
837 
838     virtual StopReason
839     GetStopReason () const
840     {
841         return eStopReasonPlanComplete;
842     }
843 
844     virtual const char *
845     GetDescription ()
846     {
847         if (m_description.empty())
848         {
849             StreamString strm;
850             m_plan_sp->GetDescription (&strm, eDescriptionLevelBrief);
851             m_description.swap (strm.GetString());
852         }
853         return m_description.c_str();
854     }
855 
856     ValueObjectSP
857     GetReturnValueObject()
858     {
859         return m_return_valobj_sp;
860     }
861 
862 private:
863     ThreadPlanSP m_plan_sp;
864     ValueObjectSP m_return_valobj_sp;
865 };
866 } // namespace lldb_private
867 
868 StopInfoSP
869 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id)
870 {
871     return StopInfoSP (new StopInfoBreakpoint (thread, break_id));
872 }
873 
874 StopInfoSP
875 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id, bool should_stop)
876 {
877     return StopInfoSP (new StopInfoBreakpoint (thread, break_id, should_stop));
878 }
879 
880 StopInfoSP
881 StopInfo::CreateStopReasonWithWatchpointID (Thread &thread, break_id_t watch_id)
882 {
883     return StopInfoSP (new StopInfoWatchpoint (thread, watch_id));
884 }
885 
886 StopInfoSP
887 StopInfo::CreateStopReasonWithSignal (Thread &thread, int signo)
888 {
889     return StopInfoSP (new StopInfoUnixSignal (thread, signo));
890 }
891 
892 StopInfoSP
893 StopInfo::CreateStopReasonToTrace (Thread &thread)
894 {
895     return StopInfoSP (new StopInfoTrace (thread));
896 }
897 
898 StopInfoSP
899 StopInfo::CreateStopReasonWithPlan (ThreadPlanSP &plan_sp, ValueObjectSP return_valobj_sp)
900 {
901     return StopInfoSP (new StopInfoThreadPlan (plan_sp, return_valobj_sp));
902 }
903 
904 StopInfoSP
905 StopInfo::CreateStopReasonWithException (Thread &thread, const char *description)
906 {
907     return StopInfoSP (new StopInfoException (thread, description));
908 }
909 
910 ValueObjectSP
911 StopInfo::GetReturnValueObject(StopInfoSP &stop_info_sp)
912 {
913     if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonPlanComplete)
914     {
915         StopInfoThreadPlan *plan_stop_info = static_cast<StopInfoThreadPlan *>(stop_info_sp.get());
916         return plan_stop_info->GetReturnValueObject();
917     }
918     else
919         return ValueObjectSP();
920 }
921