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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/lldb-python.h"
11 
12 #include "lldb/Target/StopInfo.h"
13 
14 // C Includes
15 // C++ Includes
16 #include <string>
17 
18 // Other libraries and framework includes
19 // Project includes
20 #include "lldb/Core/Log.h"
21 #include "lldb/Breakpoint/Breakpoint.h"
22 #include "lldb/Breakpoint/BreakpointLocation.h"
23 #include "lldb/Breakpoint/StoppointCallbackContext.h"
24 #include "lldb/Breakpoint/Watchpoint.h"
25 #include "lldb/Core/Debugger.h"
26 #include "lldb/Core/StreamString.h"
27 #include "lldb/Expression/ClangUserExpression.h"
28 #include "lldb/Target/Target.h"
29 #include "lldb/Target/Thread.h"
30 #include "lldb/Target/ThreadPlan.h"
31 #include "lldb/Target/Process.h"
32 #include "lldb/Target/UnixSignals.h"
33 
34 using namespace lldb;
35 using namespace lldb_private;
36 
StopInfo(Thread & thread,uint64_t value)37 StopInfo::StopInfo (Thread &thread, uint64_t value) :
38     m_thread_wp (thread.shared_from_this()),
39     m_stop_id (thread.GetProcess()->GetStopID()),
40     m_resume_id (thread.GetProcess()->GetResumeID()),
41     m_value (value),
42     m_override_should_notify (eLazyBoolCalculate),
43     m_override_should_stop (eLazyBoolCalculate)
44 {
45 }
46 
47 bool
IsValid() const48 StopInfo::IsValid () const
49 {
50     ThreadSP thread_sp (m_thread_wp.lock());
51     if (thread_sp)
52         return thread_sp->GetProcess()->GetStopID() == m_stop_id;
53     return false;
54 }
55 
56 void
MakeStopInfoValid()57 StopInfo::MakeStopInfoValid ()
58 {
59     ThreadSP thread_sp (m_thread_wp.lock());
60     if (thread_sp)
61     {
62         m_stop_id = thread_sp->GetProcess()->GetStopID();
63         m_resume_id = thread_sp->GetProcess()->GetResumeID();
64     }
65 }
66 
67 bool
HasTargetRunSinceMe()68 StopInfo::HasTargetRunSinceMe ()
69 {
70     ThreadSP thread_sp (m_thread_wp.lock());
71 
72     if (thread_sp)
73     {
74         lldb::StateType ret_type = thread_sp->GetProcess()->GetPrivateState();
75         if (ret_type == eStateRunning)
76         {
77             return true;
78         }
79         else if (ret_type == eStateStopped)
80         {
81             // This is a little tricky.  We want to count "run and stopped again before you could
82             // ask this question as a "TRUE" answer to HasTargetRunSinceMe.  But we don't want to
83             // include any running of the target done for expressions.  So we track both resumes,
84             // and resumes caused by expressions, and check if there are any resumes NOT caused
85             // by expressions.
86 
87             uint32_t curr_resume_id = thread_sp->GetProcess()->GetResumeID();
88             uint32_t last_user_expression_id = thread_sp->GetProcess()->GetLastUserExpressionResumeID ();
89             if (curr_resume_id == m_resume_id)
90             {
91                 return false;
92             }
93             else if (curr_resume_id > last_user_expression_id)
94             {
95                 return true;
96             }
97         }
98     }
99     return false;
100 }
101 
102 //----------------------------------------------------------------------
103 // StopInfoBreakpoint
104 //----------------------------------------------------------------------
105 
106 namespace lldb_private
107 {
108 class StopInfoBreakpoint : public StopInfo
109 {
110 public:
111 
StopInfoBreakpoint(Thread & thread,break_id_t break_id)112     StopInfoBreakpoint (Thread &thread, break_id_t break_id) :
113         StopInfo (thread, break_id),
114         m_description(),
115         m_should_stop (false),
116         m_should_stop_is_valid (false),
117         m_should_perform_action (true),
118         m_address (LLDB_INVALID_ADDRESS),
119         m_break_id(LLDB_INVALID_BREAK_ID),
120         m_was_one_shot (false)
121     {
122         StoreBPInfo();
123     }
124 
StopInfoBreakpoint(Thread & thread,break_id_t break_id,bool should_stop)125     StopInfoBreakpoint (Thread &thread, break_id_t break_id, bool should_stop) :
126         StopInfo (thread, break_id),
127         m_description(),
128         m_should_stop (should_stop),
129         m_should_stop_is_valid (true),
130         m_should_perform_action (true),
131         m_address (LLDB_INVALID_ADDRESS),
132         m_break_id(LLDB_INVALID_BREAK_ID),
133         m_was_one_shot (false)
134     {
135         StoreBPInfo();
136     }
137 
138     void
StoreBPInfo()139     StoreBPInfo ()
140     {
141         ThreadSP thread_sp (m_thread_wp.lock());
142         if (thread_sp)
143         {
144             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
145             if (bp_site_sp)
146             {
147                 if (bp_site_sp->GetNumberOfOwners() == 1)
148                 {
149                     BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(0);
150                     if (bp_loc_sp)
151                     {
152                         m_break_id = bp_loc_sp->GetBreakpoint().GetID();
153                         m_was_one_shot = bp_loc_sp->GetBreakpoint().IsOneShot();
154                     }
155                 }
156                 m_address = bp_site_sp->GetLoadAddress();
157             }
158         }
159     }
160 
~StopInfoBreakpoint()161     virtual ~StopInfoBreakpoint ()
162     {
163     }
164 
165     virtual StopReason
GetStopReason() const166     GetStopReason () const
167     {
168         return eStopReasonBreakpoint;
169     }
170 
171     virtual bool
ShouldStopSynchronous(Event * event_ptr)172     ShouldStopSynchronous (Event *event_ptr)
173     {
174         ThreadSP thread_sp (m_thread_wp.lock());
175         if (thread_sp)
176         {
177             if (!m_should_stop_is_valid)
178             {
179                 // Only check once if we should stop at a breakpoint
180                 BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
181                 if (bp_site_sp)
182                 {
183                     ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
184                     StoppointCallbackContext context (event_ptr, exe_ctx, true);
185                     m_should_stop = bp_site_sp->ShouldStop (&context);
186                 }
187                 else
188                 {
189                     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
190 
191                     if (log)
192                         log->Printf ("Process::%s could not find breakpoint site id: %" PRId64 "...", __FUNCTION__, m_value);
193 
194                     m_should_stop = true;
195                 }
196                 m_should_stop_is_valid = true;
197             }
198             return m_should_stop;
199         }
200         return false;
201     }
202 
203     virtual bool
DoShouldNotify(Event * event_ptr)204     DoShouldNotify (Event *event_ptr)
205     {
206         ThreadSP thread_sp (m_thread_wp.lock());
207         if (thread_sp)
208         {
209             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
210             if (bp_site_sp)
211             {
212                 bool all_internal = true;
213 
214                 for (uint32_t i = 0; i < bp_site_sp->GetNumberOfOwners(); i++)
215                 {
216                     if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal())
217                     {
218                         all_internal = false;
219                         break;
220                     }
221                 }
222                 return all_internal == false;
223             }
224         }
225         return true;
226     }
227 
228     virtual const char *
GetDescription()229     GetDescription ()
230     {
231         if (m_description.empty())
232         {
233             ThreadSP thread_sp (m_thread_wp.lock());
234             if (thread_sp)
235             {
236                 BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
237                 if (bp_site_sp)
238                 {
239                     StreamString strm;
240                     // If we have just hit an internal breakpoint, and it has a kind description, print that instead of the
241                     // full breakpoint printing:
242                     if (bp_site_sp->IsInternal())
243                     {
244                         size_t num_owners = bp_site_sp->GetNumberOfOwners();
245                         for (size_t idx = 0; idx < num_owners; idx++)
246                         {
247                             const char *kind = bp_site_sp->GetOwnerAtIndex(idx)->GetBreakpoint().GetBreakpointKind();
248                             if (kind != NULL)
249                             {
250                                 m_description.assign (kind);
251                                 return kind;
252                             }
253                         }
254                     }
255 
256                     strm.Printf("breakpoint ");
257                     bp_site_sp->GetDescription(&strm, eDescriptionLevelBrief);
258                     m_description.swap (strm.GetString());
259                 }
260                 else
261                 {
262                     StreamString strm;
263                     if (m_break_id != LLDB_INVALID_BREAK_ID)
264                     {
265                         BreakpointSP break_sp = thread_sp->GetProcess()->GetTarget().GetBreakpointByID(m_break_id);
266                         if (break_sp)
267                         {
268                             if (break_sp->IsInternal())
269                             {
270                                 const char *kind = break_sp->GetBreakpointKind();
271                                 if (kind)
272                                     strm.Printf ("internal %s breakpoint(%d).", kind, m_break_id);
273                                 else
274                                     strm.Printf ("internal breakpoint(%d).", m_break_id);
275                             }
276                             else
277                             {
278                                 strm.Printf ("breakpoint %d.", m_break_id);
279                             }
280                         }
281                         else
282                         {
283                             if (m_was_one_shot)
284                                 strm.Printf ("one-shot breakpoint %d", m_break_id);
285                             else
286                                 strm.Printf ("breakpoint %d which has been deleted.", m_break_id);
287                         }
288                     }
289                     else if (m_address == LLDB_INVALID_ADDRESS)
290                         strm.Printf("breakpoint site %" PRIi64 " which has been deleted - unknown address", m_value);
291                     else
292                         strm.Printf("breakpoint site %" PRIi64 " which has been deleted - was at 0x%" PRIx64, m_value, m_address);
293 
294                     m_description.swap (strm.GetString());
295                 }
296             }
297         }
298         return m_description.c_str();
299     }
300 
301 protected:
302     bool
ShouldStop(Event * event_ptr)303     ShouldStop (Event *event_ptr)
304     {
305         // This just reports the work done by PerformAction or the synchronous stop.  It should
306         // only ever get called after they have had a chance to run.
307         assert (m_should_stop_is_valid);
308         return m_should_stop;
309     }
310 
311     virtual void
PerformAction(Event * event_ptr)312     PerformAction (Event *event_ptr)
313     {
314         if (!m_should_perform_action)
315             return;
316         m_should_perform_action = false;
317 
318         ThreadSP thread_sp (m_thread_wp.lock());
319 
320         if (thread_sp)
321         {
322             Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_BREAKPOINTS);
323 
324             if (!thread_sp->IsValid())
325             {
326                 // This shouldn't ever happen, but just in case, don't do more harm.
327                 if (log)
328                 {
329                     log->Printf ("PerformAction got called with an invalid thread.");
330                 }
331                 m_should_stop = true;
332                 m_should_stop_is_valid = true;
333                 return;
334             }
335 
336             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
337 
338             if (bp_site_sp)
339             {
340                 size_t num_owners = bp_site_sp->GetNumberOfOwners();
341 
342                 if (num_owners == 0)
343                 {
344                     m_should_stop = true;
345                 }
346                 else
347                 {
348                     // We go through each location, and test first its condition.  If the condition says to stop,
349                     // then we run the callback for that location.  If that callback says to stop as well, then
350                     // we set m_should_stop to true; we are going to stop.
351                     // But we still want to give all the breakpoints whose conditions say we are going to stop a
352                     // chance to run their callbacks.
353                     // Of course if any callback restarts the target by putting "continue" in the callback, then
354                     // we're going to restart, without running the rest of the callbacks.  And in this case we will
355                     // end up not stopping even if another location said we should stop.  But that's better than not
356                     // running all the callbacks.
357 
358                     m_should_stop = false;
359 
360                     ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
361                     Process *process  = exe_ctx.GetProcessPtr();
362                     if (process->GetModIDRef().IsLastResumeForUserExpression())
363                     {
364                         // If we are in the middle of evaluating an expression, don't run asynchronous breakpoint commands or
365                         // expressions.  That could lead to infinite recursion if the command or condition re-calls the function
366                         // with this breakpoint.
367                         // TODO: We can keep a list of the breakpoints we've seen while running expressions in the nested
368                         // PerformAction calls that can arise when the action runs a function that hits another breakpoint,
369                         // and only stop running commands when we see the same breakpoint hit a second time.
370 
371                         m_should_stop_is_valid = true;
372                         if (log)
373                             log->Printf ("StopInfoBreakpoint::PerformAction - Hit a breakpoint while running an expression,"
374                                          " not running commands to avoid recursion.");
375                         bool ignoring_breakpoints = process->GetIgnoreBreakpointsInExpressions();
376                         if (ignoring_breakpoints)
377                         {
378                             m_should_stop = false;
379                             // Internal breakpoints will always stop.
380                             for (size_t j = 0; j < num_owners; j++)
381                             {
382                                 lldb::BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(j);
383                                 if (bp_loc_sp->GetBreakpoint().IsInternal())
384                                 {
385                                     m_should_stop = true;
386                                     break;
387                                 }
388                             }
389                         }
390                         else
391                         {
392                             m_should_stop = true;
393                         }
394                         if (log)
395                             log->Printf ("StopInfoBreakpoint::PerformAction - in expression, continuing: %s.",
396                                          m_should_stop ? "true" : "false");
397                         process->GetTarget().GetDebugger().GetAsyncOutputStream()->Printf("Warning: hit breakpoint while "
398                                                "running function, skipping commands and conditions to prevent recursion.");
399                         return;
400                     }
401 
402                     StoppointCallbackContext context (event_ptr, exe_ctx, false);
403 
404                     // Let's copy the breakpoint locations out of the site and store them in a local list.  That way if
405                     // one of the breakpoint actions changes the site, then we won't be operating on a bad list.
406 
407                     BreakpointLocationCollection site_locations;
408                     for (size_t j = 0; j < num_owners; j++)
409                         site_locations.Add(bp_site_sp->GetOwnerAtIndex(j));
410 
411                     for (size_t j = 0; j < num_owners; j++)
412                     {
413                         lldb::BreakpointLocationSP bp_loc_sp = site_locations.GetByIndex(j);
414 
415                         // If another action disabled this breakpoint or its location, then don't run the actions.
416                         if (!bp_loc_sp->IsEnabled() || !bp_loc_sp->GetBreakpoint().IsEnabled())
417                             continue;
418 
419                         // The breakpoint site may have many locations associated with it, not all of them valid for
420                         // this thread.  Skip the ones that aren't:
421                         if (!bp_loc_sp->ValidForThisThread(thread_sp.get()))
422                             continue;
423 
424                         // First run the condition for the breakpoint.  If that says we should stop, then we'll run
425                         // the callback for the breakpoint.  If the callback says we shouldn't stop that will win.
426 
427                         if (bp_loc_sp->GetConditionText() != NULL)
428                         {
429                             Error condition_error;
430                             bool condition_says_stop = bp_loc_sp->ConditionSaysStop(exe_ctx, condition_error);
431 
432                             if (!condition_error.Success())
433                             {
434                                 Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
435                                 StreamSP error_sp = debugger.GetAsyncErrorStream ();
436                                 error_sp->Printf ("Stopped due to an error evaluating condition of breakpoint ");
437                                 bp_loc_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
438                                 error_sp->Printf (": \"%s\"",
439                                                   bp_loc_sp->GetConditionText());
440                                 error_sp->EOL();
441                                 const char *err_str = condition_error.AsCString("<Unknown Error>");
442                                 if (log)
443                                     log->Printf("Error evaluating condition: \"%s\"\n", err_str);
444 
445                                 error_sp->PutCString (err_str);
446                                 error_sp->EOL();
447                                 error_sp->Flush();
448                                 // If the condition fails to be parsed or run, we should stop.
449                                 condition_says_stop = true;
450                             }
451                             else
452                             {
453                                 if (!condition_says_stop)
454                                     continue;
455                             }
456                         }
457 
458                         bool callback_says_stop;
459 
460                         // FIXME: For now the callbacks have to run in async mode - the first time we restart we need
461                         // to get out of there.  So set it here.
462                         // When we figure out how to nest breakpoint hits then this will change.
463 
464                         Debugger &debugger = thread_sp->CalculateTarget()->GetDebugger();
465                         bool old_async = debugger.GetAsyncExecution();
466                         debugger.SetAsyncExecution (true);
467 
468                         callback_says_stop = bp_loc_sp->InvokeCallback (&context);
469 
470                         debugger.SetAsyncExecution (old_async);
471 
472                         if (callback_says_stop)
473                             m_should_stop = true;
474 
475                         // If we are going to stop for this breakpoint, then remove the breakpoint.
476                         if (callback_says_stop && bp_loc_sp && bp_loc_sp->GetBreakpoint().IsOneShot())
477                         {
478                             thread_sp->GetProcess()->GetTarget().RemoveBreakpointByID (bp_loc_sp->GetBreakpoint().GetID());
479                         }
480 
481                         // Also make sure that the callback hasn't continued the target.
482                         // If it did, when we'll set m_should_start to false and get out of here.
483                         if (HasTargetRunSinceMe ())
484                         {
485                             m_should_stop = false;
486                             break;
487                         }
488                     }
489                 }
490                 // We've figured out what this stop wants to do, so mark it as valid so we don't compute it again.
491                 m_should_stop_is_valid = true;
492 
493             }
494             else
495             {
496                 m_should_stop = true;
497                 m_should_stop_is_valid = true;
498                 Log * log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
499 
500                 if (log_process)
501                     log_process->Printf ("Process::%s could not find breakpoint site id: %" PRId64 "...", __FUNCTION__, m_value);
502             }
503             if (log)
504                 log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
505         }
506     }
507 
508 private:
509     std::string m_description;
510     bool m_should_stop;
511     bool m_should_stop_is_valid;
512     bool m_should_perform_action; // Since we are trying to preserve the "state" of the system even if we run functions
513                                   // etc. behind the users backs, we need to make sure we only REALLY perform the action once.
514     lldb::addr_t m_address;       // We use this to capture the breakpoint site address when we create the StopInfo,
515                                   // in case somebody deletes it between the time the StopInfo is made and the
516                                   // description is asked for.
517     lldb::break_id_t m_break_id;
518     bool m_was_one_shot;
519 };
520 
521 
522 //----------------------------------------------------------------------
523 // StopInfoWatchpoint
524 //----------------------------------------------------------------------
525 
526 class StopInfoWatchpoint : public StopInfo
527 {
528 public:
529     // Make sure watchpoint is properly disabled and subsequently enabled while performing watchpoint actions.
530     class WatchpointSentry {
531     public:
WatchpointSentry(Process * p,Watchpoint * w)532         WatchpointSentry(Process *p, Watchpoint *w):
533             process(p),
534             watchpoint(w)
535         {
536             if (process && watchpoint)
537             {
538                 const bool notify = false;
539                 watchpoint->TurnOnEphemeralMode();
540                 process->DisableWatchpoint(watchpoint, notify);
541             }
542         }
~WatchpointSentry()543         ~WatchpointSentry()
544         {
545             if (process && watchpoint)
546             {
547                 if (!watchpoint->IsDisabledDuringEphemeralMode())
548                 {
549                     const bool notify = false;
550                     process->EnableWatchpoint(watchpoint, notify);
551                 }
552                 watchpoint->TurnOffEphemeralMode();
553             }
554         }
555     private:
556         Process *process;
557         Watchpoint *watchpoint;
558     };
559 
StopInfoWatchpoint(Thread & thread,break_id_t watch_id)560     StopInfoWatchpoint (Thread &thread, break_id_t watch_id) :
561         StopInfo(thread, watch_id),
562         m_description(),
563         m_should_stop(false),
564         m_should_stop_is_valid(false)
565     {
566     }
567 
~StopInfoWatchpoint()568     virtual ~StopInfoWatchpoint ()
569     {
570     }
571 
572     virtual StopReason
GetStopReason() const573     GetStopReason () const
574     {
575         return eStopReasonWatchpoint;
576     }
577 
578     virtual const char *
GetDescription()579     GetDescription ()
580     {
581         if (m_description.empty())
582         {
583             StreamString strm;
584             strm.Printf("watchpoint %" PRIi64, m_value);
585             m_description.swap (strm.GetString());
586         }
587         return m_description.c_str();
588     }
589 
590 protected:
591     virtual bool
ShouldStopSynchronous(Event * event_ptr)592     ShouldStopSynchronous (Event *event_ptr)
593     {
594         // ShouldStop() method is idempotent and should not affect hit count.
595         // See Process::RunPrivateStateThread()->Process()->HandlePrivateEvent()
596         // -->Process()::ShouldBroadcastEvent()->ThreadList::ShouldStop()->
597         // Thread::ShouldStop()->ThreadPlanBase::ShouldStop()->
598         // StopInfoWatchpoint::ShouldStop() and
599         // Event::DoOnRemoval()->Process::ProcessEventData::DoOnRemoval()->
600         // StopInfoWatchpoint::PerformAction().
601         if (m_should_stop_is_valid)
602             return m_should_stop;
603 
604         ThreadSP thread_sp (m_thread_wp.lock());
605         if (thread_sp)
606         {
607             WatchpointSP wp_sp (thread_sp->CalculateTarget()->GetWatchpointList().FindByID(GetValue()));
608             if (wp_sp)
609             {
610                 // Check if we should stop at a watchpoint.
611                 ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
612                 StoppointCallbackContext context (event_ptr, exe_ctx, true);
613                 m_should_stop = wp_sp->ShouldStop (&context);
614             }
615             else
616             {
617                 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
618 
619                 if (log)
620                     log->Printf ("Process::%s could not find watchpoint location id: %" PRId64 "...",
621                                  __FUNCTION__, GetValue());
622 
623                 m_should_stop = true;
624             }
625         }
626         m_should_stop_is_valid = true;
627         return m_should_stop;
628     }
629 
630     bool
ShouldStop(Event * event_ptr)631     ShouldStop (Event *event_ptr)
632     {
633         // This just reports the work done by PerformAction or the synchronous stop.  It should
634         // only ever get called after they have had a chance to run.
635         assert (m_should_stop_is_valid);
636         return m_should_stop;
637     }
638 
639     virtual void
PerformAction(Event * event_ptr)640     PerformAction (Event *event_ptr)
641     {
642         Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_WATCHPOINTS);
643         // We're going to calculate if we should stop or not in some way during the course of
644         // this code.  Also by default we're going to stop, so set that here.
645         m_should_stop = true;
646 
647         ThreadSP thread_sp (m_thread_wp.lock());
648         if (thread_sp)
649         {
650 
651             WatchpointSP wp_sp (thread_sp->CalculateTarget()->GetWatchpointList().FindByID(GetValue()));
652             if (wp_sp)
653             {
654                 ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
655                 Process* process = exe_ctx.GetProcessPtr();
656 
657                 // This sentry object makes sure the current watchpoint is disabled while performing watchpoint actions,
658                 // and it is then enabled after we are finished.
659                 WatchpointSentry sentry(process, wp_sp.get());
660 
661                 {
662                     // check if this process is running on an architecture where watchpoints trigger
663                     // before the associated instruction runs. if so, disable the WP, single-step and then
664                     // re-enable the watchpoint
665                     if (process)
666                     {
667                         uint32_t num;
668                         bool wp_triggers_after;
669                         if (process->GetWatchpointSupportInfo(num, wp_triggers_after).Success())
670                         {
671                             if (!wp_triggers_after)
672                             {
673                                 StopInfoSP stored_stop_info_sp = thread_sp->GetStopInfo();
674                                 assert (stored_stop_info_sp.get() == this);
675 
676                                 ThreadPlanSP new_plan_sp(thread_sp->QueueThreadPlanForStepSingleInstruction(false, // step-over
677                                                                                                         false,     // abort_other_plans
678                                                                                                         true));    // stop_other_threads
679                                 new_plan_sp->SetIsMasterPlan (true);
680                                 new_plan_sp->SetOkayToDiscard (false);
681                                 new_plan_sp->SetPrivate (true);
682                                 process->GetThreadList().SetSelectedThreadByID (thread_sp->GetID());
683                                 process->Resume ();
684                                 process->WaitForProcessToStop (NULL);
685                                 process->GetThreadList().SetSelectedThreadByID (thread_sp->GetID());
686                                 thread_sp->SetStopInfo(stored_stop_info_sp);
687                             }
688                         }
689                     }
690                 }
691 
692                 if (m_should_stop && wp_sp->GetConditionText() != NULL)
693                 {
694                     // We need to make sure the user sees any parse errors in their condition, so we'll hook the
695                     // constructor errors up to the debugger's Async I/O.
696                     ExecutionResults result_code;
697                     ValueObjectSP result_value_sp;
698                     const bool unwind_on_error = true;
699                     const bool ignore_breakpoints = true;
700                     Error error;
701                     result_code = ClangUserExpression::EvaluateWithError (exe_ctx,
702                                                                           eExecutionPolicyOnlyWhenNeeded,
703                                                                           lldb::eLanguageTypeUnknown,
704                                                                           ClangUserExpression::eResultTypeAny,
705                                                                           unwind_on_error,
706                                                                           ignore_breakpoints,
707                                                                           wp_sp->GetConditionText(),
708                                                                           NULL,
709                                                                           result_value_sp,
710                                                                           error,
711                                                                           true,
712                                                                           ClangUserExpression::kDefaultTimeout);
713                     if (result_code == eExecutionCompleted)
714                     {
715                         if (result_value_sp)
716                         {
717                             Scalar scalar_value;
718                             if (result_value_sp->ResolveValue (scalar_value))
719                             {
720                                 if (scalar_value.ULongLong(1) == 0)
721                                 {
722                                     // We have been vetoed.  This takes precedence over querying
723                                     // the watchpoint whether it should stop (aka ignore count and
724                                     // friends).  See also StopInfoWatchpoint::ShouldStop() as well
725                                     // as Process::ProcessEventData::DoOnRemoval().
726                                     m_should_stop = false;
727                                 }
728                                 else
729                                     m_should_stop = true;
730                                 if (log)
731                                     log->Printf("Condition successfully evaluated, result is %s.\n",
732                                                 m_should_stop ? "true" : "false");
733                             }
734                             else
735                             {
736                                 m_should_stop = true;
737                                 if (log)
738                                     log->Printf("Failed to get an integer result from the expression.");
739                             }
740                         }
741                     }
742                     else
743                     {
744                         Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
745                         StreamSP error_sp = debugger.GetAsyncErrorStream ();
746                         error_sp->Printf ("Stopped due to an error evaluating condition of watchpoint ");
747                         wp_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
748                         error_sp->Printf (": \"%s\"",
749                                           wp_sp->GetConditionText());
750                         error_sp->EOL();
751                         const char *err_str = error.AsCString("<Unknown Error>");
752                         if (log)
753                             log->Printf("Error evaluating condition: \"%s\"\n", err_str);
754 
755                         error_sp->PutCString (err_str);
756                         error_sp->EOL();
757                         error_sp->Flush();
758                         // If the condition fails to be parsed or run, we should stop.
759                         m_should_stop = true;
760                     }
761                 }
762 
763                 // If the condition says to stop, we run the callback to further decide whether to stop.
764                 if (m_should_stop)
765                 {
766                     StoppointCallbackContext context (event_ptr, exe_ctx, false);
767                     bool stop_requested = wp_sp->InvokeCallback (&context);
768                     // Also make sure that the callback hasn't continued the target.
769                     // If it did, when we'll set m_should_stop to false and get out of here.
770                     if (HasTargetRunSinceMe ())
771                         m_should_stop = false;
772 
773                     if (m_should_stop && !stop_requested)
774                     {
775                         // We have been vetoed by the callback mechanism.
776                         m_should_stop = false;
777                     }
778                 }
779                 // Finally, if we are going to stop, print out the new & old values:
780                 if (m_should_stop)
781                 {
782                     wp_sp->CaptureWatchedValue(exe_ctx);
783 
784                     Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
785                     StreamSP output_sp = debugger.GetAsyncOutputStream ();
786                     wp_sp->DumpSnapshots(output_sp.get());
787                     output_sp->EOL();
788                     output_sp->Flush();
789                 }
790 
791             }
792             else
793             {
794                 Log * log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
795 
796                 if (log_process)
797                     log_process->Printf ("Process::%s could not find watchpoint id: %" PRId64 "...", __FUNCTION__, m_value);
798             }
799             if (log)
800                 log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
801 
802             m_should_stop_is_valid = true;
803         }
804     }
805 
806 private:
807     std::string m_description;
808     bool m_should_stop;
809     bool m_should_stop_is_valid;
810 };
811 
812 
813 
814 //----------------------------------------------------------------------
815 // StopInfoUnixSignal
816 //----------------------------------------------------------------------
817 
818 class StopInfoUnixSignal : public StopInfo
819 {
820 public:
821 
StopInfoUnixSignal(Thread & thread,int signo)822     StopInfoUnixSignal (Thread &thread, int signo) :
823         StopInfo (thread, signo)
824     {
825     }
826 
~StopInfoUnixSignal()827     virtual ~StopInfoUnixSignal ()
828     {
829     }
830 
831 
832     virtual StopReason
GetStopReason() const833     GetStopReason () const
834     {
835         return eStopReasonSignal;
836     }
837 
838     virtual bool
ShouldStopSynchronous(Event * event_ptr)839     ShouldStopSynchronous (Event *event_ptr)
840     {
841         ThreadSP thread_sp (m_thread_wp.lock());
842         if (thread_sp)
843             return thread_sp->GetProcess()->GetUnixSignals().GetShouldStop (m_value);
844         return false;
845     }
846 
847     virtual bool
ShouldStop(Event * event_ptr)848     ShouldStop (Event *event_ptr)
849     {
850         ThreadSP thread_sp (m_thread_wp.lock());
851         if (thread_sp)
852             return thread_sp->GetProcess()->GetUnixSignals().GetShouldStop (m_value);
853         return false;
854     }
855 
856 
857     // If should stop returns false, check if we should notify of this event
858     virtual bool
DoShouldNotify(Event * event_ptr)859     DoShouldNotify (Event *event_ptr)
860     {
861         ThreadSP thread_sp (m_thread_wp.lock());
862         if (thread_sp)
863         {
864             bool should_notify = thread_sp->GetProcess()->GetUnixSignals().GetShouldNotify (m_value);
865             if (should_notify)
866             {
867                 StreamString strm;
868                 strm.Printf ("thread %d received signal: %s",
869                              thread_sp->GetIndexID(),
870                              thread_sp->GetProcess()->GetUnixSignals().GetSignalAsCString (m_value));
871                 Process::ProcessEventData::AddRestartedReason(event_ptr, strm.GetData());
872             }
873             return should_notify;
874         }
875         return true;
876     }
877 
878 
879     virtual void
WillResume(lldb::StateType resume_state)880     WillResume (lldb::StateType resume_state)
881     {
882         ThreadSP thread_sp (m_thread_wp.lock());
883         if (thread_sp)
884         {
885             if (thread_sp->GetProcess()->GetUnixSignals().GetShouldSuppress(m_value) == false)
886                 thread_sp->SetResumeSignal(m_value);
887         }
888     }
889 
890     virtual const char *
GetDescription()891     GetDescription ()
892     {
893         if (m_description.empty())
894         {
895             ThreadSP thread_sp (m_thread_wp.lock());
896             if (thread_sp)
897             {
898                 StreamString strm;
899                 const char *signal_name = thread_sp->GetProcess()->GetUnixSignals().GetSignalAsCString (m_value);
900                 if (signal_name)
901                     strm.Printf("signal %s", signal_name);
902                 else
903                     strm.Printf("signal %" PRIi64, m_value);
904                 m_description.swap (strm.GetString());
905             }
906         }
907         return m_description.c_str();
908     }
909 };
910 
911 //----------------------------------------------------------------------
912 // StopInfoTrace
913 //----------------------------------------------------------------------
914 
915 class StopInfoTrace : public StopInfo
916 {
917 public:
918 
StopInfoTrace(Thread & thread)919     StopInfoTrace (Thread &thread) :
920         StopInfo (thread, LLDB_INVALID_UID)
921     {
922     }
923 
~StopInfoTrace()924     virtual ~StopInfoTrace ()
925     {
926     }
927 
928     virtual StopReason
GetStopReason() const929     GetStopReason () const
930     {
931         return eStopReasonTrace;
932     }
933 
934     virtual const char *
GetDescription()935     GetDescription ()
936     {
937         if (m_description.empty())
938         return "trace";
939         else
940             return m_description.c_str();
941     }
942 };
943 
944 
945 //----------------------------------------------------------------------
946 // StopInfoException
947 //----------------------------------------------------------------------
948 
949 class StopInfoException : public StopInfo
950 {
951 public:
952 
StopInfoException(Thread & thread,const char * description)953     StopInfoException (Thread &thread, const char *description) :
954         StopInfo (thread, LLDB_INVALID_UID)
955     {
956         if (description)
957             SetDescription (description);
958     }
959 
960     virtual
~StopInfoException()961     ~StopInfoException ()
962     {
963     }
964 
965     virtual StopReason
GetStopReason() const966     GetStopReason () const
967     {
968         return eStopReasonException;
969     }
970 
971     virtual const char *
GetDescription()972     GetDescription ()
973     {
974         if (m_description.empty())
975             return "exception";
976         else
977             return m_description.c_str();
978     }
979 };
980 
981 
982 //----------------------------------------------------------------------
983 // StopInfoThreadPlan
984 //----------------------------------------------------------------------
985 
986 class StopInfoThreadPlan : public StopInfo
987 {
988 public:
989 
StopInfoThreadPlan(ThreadPlanSP & plan_sp,ValueObjectSP & return_valobj_sp)990     StopInfoThreadPlan (ThreadPlanSP &plan_sp, ValueObjectSP &return_valobj_sp) :
991         StopInfo (plan_sp->GetThread(), LLDB_INVALID_UID),
992         m_plan_sp (plan_sp),
993         m_return_valobj_sp (return_valobj_sp)
994     {
995     }
996 
~StopInfoThreadPlan()997     virtual ~StopInfoThreadPlan ()
998     {
999     }
1000 
1001     virtual StopReason
GetStopReason() const1002     GetStopReason () const
1003     {
1004         return eStopReasonPlanComplete;
1005     }
1006 
1007     virtual const char *
GetDescription()1008     GetDescription ()
1009     {
1010         if (m_description.empty())
1011         {
1012             StreamString strm;
1013             m_plan_sp->GetDescription (&strm, eDescriptionLevelBrief);
1014             m_description.swap (strm.GetString());
1015         }
1016         return m_description.c_str();
1017     }
1018 
1019     ValueObjectSP
GetReturnValueObject()1020     GetReturnValueObject()
1021     {
1022         return m_return_valobj_sp;
1023     }
1024 
1025 protected:
1026     virtual bool
ShouldStop(Event * event_ptr)1027     ShouldStop (Event *event_ptr)
1028     {
1029         if (m_plan_sp)
1030             return m_plan_sp->ShouldStop(event_ptr);
1031         else
1032             return StopInfo::ShouldStop(event_ptr);
1033     }
1034 
1035 private:
1036     ThreadPlanSP m_plan_sp;
1037     ValueObjectSP m_return_valobj_sp;
1038 };
1039 
1040 class StopInfoExec : public StopInfo
1041 {
1042 public:
1043 
StopInfoExec(Thread & thread)1044     StopInfoExec (Thread &thread) :
1045         StopInfo (thread, LLDB_INVALID_UID),
1046         m_performed_action (false)
1047     {
1048     }
1049 
1050     virtual
~StopInfoExec()1051     ~StopInfoExec ()
1052     {
1053     }
1054 
1055     virtual StopReason
GetStopReason() const1056     GetStopReason () const
1057     {
1058         return eStopReasonExec;
1059     }
1060 
1061     virtual const char *
GetDescription()1062     GetDescription ()
1063     {
1064         return "exec";
1065     }
1066 protected:
1067 
1068     virtual void
PerformAction(Event * event_ptr)1069     PerformAction (Event *event_ptr)
1070     {
1071         // Only perform the action once
1072         if (m_performed_action)
1073             return;
1074         m_performed_action = true;
1075         ThreadSP thread_sp (m_thread_wp.lock());
1076         if (thread_sp)
1077             thread_sp->GetProcess()->DidExec();
1078     }
1079 
1080     bool m_performed_action;
1081 };
1082 
1083 } // namespace lldb_private
1084 
1085 StopInfoSP
CreateStopReasonWithBreakpointSiteID(Thread & thread,break_id_t break_id)1086 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id)
1087 {
1088     return StopInfoSP (new StopInfoBreakpoint (thread, break_id));
1089 }
1090 
1091 StopInfoSP
CreateStopReasonWithBreakpointSiteID(Thread & thread,break_id_t break_id,bool should_stop)1092 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id, bool should_stop)
1093 {
1094     return StopInfoSP (new StopInfoBreakpoint (thread, break_id, should_stop));
1095 }
1096 
1097 StopInfoSP
CreateStopReasonWithWatchpointID(Thread & thread,break_id_t watch_id)1098 StopInfo::CreateStopReasonWithWatchpointID (Thread &thread, break_id_t watch_id)
1099 {
1100     return StopInfoSP (new StopInfoWatchpoint (thread, watch_id));
1101 }
1102 
1103 StopInfoSP
CreateStopReasonWithSignal(Thread & thread,int signo)1104 StopInfo::CreateStopReasonWithSignal (Thread &thread, int signo)
1105 {
1106     return StopInfoSP (new StopInfoUnixSignal (thread, signo));
1107 }
1108 
1109 StopInfoSP
CreateStopReasonToTrace(Thread & thread)1110 StopInfo::CreateStopReasonToTrace (Thread &thread)
1111 {
1112     return StopInfoSP (new StopInfoTrace (thread));
1113 }
1114 
1115 StopInfoSP
CreateStopReasonWithPlan(ThreadPlanSP & plan_sp,ValueObjectSP return_valobj_sp)1116 StopInfo::CreateStopReasonWithPlan (ThreadPlanSP &plan_sp, ValueObjectSP return_valobj_sp)
1117 {
1118     return StopInfoSP (new StopInfoThreadPlan (plan_sp, return_valobj_sp));
1119 }
1120 
1121 StopInfoSP
CreateStopReasonWithException(Thread & thread,const char * description)1122 StopInfo::CreateStopReasonWithException (Thread &thread, const char *description)
1123 {
1124     return StopInfoSP (new StopInfoException (thread, description));
1125 }
1126 
1127 StopInfoSP
CreateStopReasonWithExec(Thread & thread)1128 StopInfo::CreateStopReasonWithExec (Thread &thread)
1129 {
1130     return StopInfoSP (new StopInfoExec (thread));
1131 }
1132 
1133 ValueObjectSP
GetReturnValueObject(StopInfoSP & stop_info_sp)1134 StopInfo::GetReturnValueObject(StopInfoSP &stop_info_sp)
1135 {
1136     if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonPlanComplete)
1137     {
1138         StopInfoThreadPlan *plan_stop_info = static_cast<StopInfoThreadPlan *>(stop_info_sp.get());
1139         return plan_stop_info->GetReturnValueObject();
1140     }
1141     else
1142         return ValueObjectSP();
1143 }
1144