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/Core/Debugger.h"
23 #include "lldb/Core/StreamString.h"
24 #include "lldb/Expression/ClangUserExpression.h"
25 #include "lldb/Target/Target.h"
26 #include "lldb/Target/Thread.h"
27 #include "lldb/Target/ThreadPlan.h"
28 #include "lldb/Target/Process.h"
29 #include "lldb/Target/UnixSignals.h"
30 
31 using namespace lldb;
32 using namespace lldb_private;
33 
34 StopInfo::StopInfo (Thread &thread, uint64_t value) :
35     m_thread (thread),
36     m_stop_id (thread.GetProcess().GetStopID()),
37     m_value (value)
38 {
39 }
40 
41 bool
42 StopInfo::IsValid () const
43 {
44     return m_thread.GetProcess().GetStopID() == m_stop_id;
45 }
46 
47 void
48 StopInfo::MakeStopInfoValid ()
49 {
50     m_stop_id = m_thread.GetProcess().GetStopID();
51 }
52 
53 lldb::StateType
54 StopInfo::GetPrivateState ()
55 {
56     return m_thread.GetProcess().GetPrivateState();
57 }
58 
59 //----------------------------------------------------------------------
60 // StopInfoBreakpoint
61 //----------------------------------------------------------------------
62 
63 namespace lldb_private
64 {
65 class StopInfoBreakpoint : public StopInfo
66 {
67 public:
68 
69     StopInfoBreakpoint (Thread &thread, break_id_t break_id) :
70         StopInfo (thread, break_id),
71         m_description(),
72         m_should_stop (false),
73         m_should_stop_is_valid (false),
74         m_should_perform_action (true)
75     {
76     }
77 
78     StopInfoBreakpoint (Thread &thread, break_id_t break_id, bool should_stop) :
79         StopInfo (thread, break_id),
80         m_description(),
81         m_should_stop (should_stop),
82         m_should_stop_is_valid (true),
83         m_should_perform_action (true)
84     {
85     }
86 
87     virtual ~StopInfoBreakpoint ()
88     {
89     }
90 
91     virtual StopReason
92     GetStopReason () const
93     {
94         return eStopReasonBreakpoint;
95     }
96 
97     virtual bool
98     ShouldStop (Event *event_ptr)
99     {
100         if (!m_should_stop_is_valid)
101         {
102             // Only check once if we should stop at a breakpoint
103             BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
104             if (bp_site_sp)
105             {
106                 StoppointCallbackContext context (event_ptr,
107                                                   &m_thread.GetProcess(),
108                                                   &m_thread,
109                                                   m_thread.GetStackFrameAtIndex(0).get(),
110                                                   true);
111 
112                 m_should_stop = bp_site_sp->ShouldStop (&context);
113             }
114             else
115             {
116                 LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
117 
118                 if (log)
119                     log->Printf ("Process::%s could not find breakpoint site id: %lld...", __FUNCTION__, m_value);
120 
121                 m_should_stop = true;
122             }
123             m_should_stop_is_valid = true;
124         }
125         return m_should_stop;
126     }
127 
128     virtual void
129     PerformAction (Event *event_ptr)
130     {
131         if (!m_should_perform_action)
132             return;
133         m_should_perform_action = false;
134 
135         LogSP log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_BREAKPOINTS);
136         // We're going to calculate whether we should stop or not in some way during the course of
137         // this code.  So set the valid flag here.  Also by default we're going to stop, so
138         // set that here too.
139         // m_should_stop_is_valid = true;
140         m_should_stop = true;
141 
142         BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
143         if (bp_site_sp)
144         {
145             size_t num_owners = bp_site_sp->GetNumberOfOwners();
146 
147             // We only continue from the callbacks if ALL the callbacks want us to continue.
148             // However we want to run all the callbacks, except of course if one of them actually
149             // resumes the target.
150             // So we use stop_requested to track what we're were asked to do.
151             bool stop_requested = true;
152             for (size_t j = 0; j < num_owners; j++)
153             {
154                 lldb::BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(j);
155                 StoppointCallbackContext context (event_ptr,
156                                                   &m_thread.GetProcess(),
157                                                   &m_thread,
158                                                   m_thread.GetStackFrameAtIndex(0).get(),
159                                                   false);
160                 stop_requested = bp_loc_sp->InvokeCallback (&context);
161                 // Also make sure that the callback hasn't continued the target.
162                 // If it did, when we'll set m_should_start to false and get out of here.
163                 if (GetPrivateState() == eStateRunning)
164                     m_should_stop = false;
165             }
166 
167             if (m_should_stop && !stop_requested)
168             {
169                 m_should_stop_is_valid = true;
170                 m_should_stop = false;
171             }
172 
173             // Okay, so now if all the callbacks say we should stop, let's try the Conditions:
174             if (m_should_stop)
175             {
176                 size_t num_owners = bp_site_sp->GetNumberOfOwners();
177                 for (size_t j = 0; j < num_owners; j++)
178                 {
179                     lldb::BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(j);
180                     if (bp_loc_sp->GetConditionText() != NULL)
181                     {
182                         // We need to make sure the user sees any parse errors in their condition, so we'll hook the
183                         // constructor errors up to the debugger's Async I/O.
184 
185                         StoppointCallbackContext context (event_ptr,
186                                                           &m_thread.GetProcess(),
187                                                           &m_thread,
188                                                           m_thread.GetStackFrameAtIndex(0).get(),
189                                                           false);
190                         ValueObjectSP result_valobj_sp;
191 
192                         ExecutionResults result_code;
193                         ValueObjectSP result_value_sp;
194                         const bool discard_on_error = true;
195                         Error error;
196                         result_code = ClangUserExpression::EvaluateWithError (context.exe_ctx,
197                                                                 discard_on_error,
198                                                                 bp_loc_sp->GetConditionText(),
199                                                                 NULL,
200                                                                 result_value_sp,
201                                                                 error);
202                         if (result_code == eExecutionCompleted)
203                         {
204                             if (result_value_sp)
205                             {
206                                 Scalar scalar_value;
207                                 if (result_value_sp->ResolveValue (scalar_value))
208                                 {
209                                     if (scalar_value.ULongLong(1) == 0)
210                                         m_should_stop = false;
211                                     else
212                                         m_should_stop = true;
213                                     if (log)
214                                         log->Printf("Condition successfully evaluated, result is %s.\n",
215                                                     m_should_stop ? "true" : "false");
216                                 }
217                                 else
218                                 {
219                                     m_should_stop = true;
220                                     if (log)
221                                         log->Printf("Failed to get an integer result from the expression.");
222                                 }
223                             }
224                         }
225                         else
226                         {
227                             Debugger &debugger = context.exe_ctx.target->GetDebugger();
228                             StreamSP error_sp = debugger.GetAsyncErrorStream ();
229                             error_sp->Printf ("Stopped due to an error evaluating condition of breakpoint ");
230                             bp_loc_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
231                             error_sp->Printf (": \"%s\"",
232                                               bp_loc_sp->GetConditionText());
233                             error_sp->EOL();
234                             const char *err_str = error.AsCString("<Unknown Error>");
235                             if (log)
236                                 log->Printf("Error evaluating condition: \"%s\"\n", err_str);
237 
238                             error_sp->PutCString (err_str);
239                             error_sp->EOL();
240                             error_sp->Flush();
241                             // If the condition fails to be parsed or run, we should stop.
242                             m_should_stop = true;
243                         }
244                     }
245 
246                     // If any condition says we should stop, then we're going to stop, so we don't need
247                     // to evaluate the others.
248                     if (m_should_stop)
249                         break;
250                 }
251             }
252         }
253         else
254         {
255             LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
256 
257             if (log)
258                 log->Printf ("Process::%s could not find breakpoint site id: %lld...", __FUNCTION__, m_value);
259         }
260         if (log)
261             log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
262     }
263 
264     virtual bool
265     ShouldNotify (Event *event_ptr)
266     {
267         BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
268         if (bp_site_sp)
269         {
270             bool all_internal = true;
271 
272             for (uint32_t i = 0; i < bp_site_sp->GetNumberOfOwners(); i++)
273             {
274                 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal())
275                 {
276                     all_internal = false;
277                     break;
278                 }
279             }
280             return all_internal == false;
281         }
282         return true;
283     }
284 
285     virtual const char *
286     GetDescription ()
287     {
288         if (m_description.empty())
289         {
290             BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
291             if (bp_site_sp)
292             {
293                 StreamString strm;
294                 strm.Printf("breakpoint ");
295                 bp_site_sp->GetDescription(&strm, eDescriptionLevelBrief);
296                 m_description.swap (strm.GetString());
297             }
298             else
299             {
300                 StreamString strm;
301                 strm.Printf("breakpoint site %lli", m_value);
302                 m_description.swap (strm.GetString());
303             }
304         }
305         return m_description.c_str();
306     }
307 
308 private:
309     std::string m_description;
310     bool m_should_stop;
311     bool m_should_stop_is_valid;
312     bool m_should_perform_action; // Since we are trying to preserve the "state" of the system even if we run functions
313                                   // etc. behind the users backs, we need to make sure we only REALLY perform the action once.
314 };
315 
316 
317 //----------------------------------------------------------------------
318 // StopInfoWatchpoint
319 //----------------------------------------------------------------------
320 
321 class StopInfoWatchpoint : public StopInfo
322 {
323 public:
324 
325     StopInfoWatchpoint (Thread &thread, break_id_t watch_id) :
326         StopInfo (thread, watch_id),
327         m_description()
328     {
329     }
330 
331     virtual ~StopInfoWatchpoint ()
332     {
333     }
334 
335     virtual StopReason
336     GetStopReason () const
337     {
338         return eStopReasonWatchpoint;
339     }
340 
341     virtual const char *
342     GetDescription ()
343     {
344         if (m_description.empty())
345         {
346             StreamString strm;
347             strm.Printf("watchpoint %lli", m_value);
348             m_description.swap (strm.GetString());
349         }
350         return m_description.c_str();
351     }
352 
353 
354 
355 private:
356     std::string m_description;
357 };
358 
359 
360 
361 //----------------------------------------------------------------------
362 // StopInfoUnixSignal
363 //----------------------------------------------------------------------
364 
365 class StopInfoUnixSignal : public StopInfo
366 {
367 public:
368 
369     StopInfoUnixSignal (Thread &thread, int signo) :
370         StopInfo (thread, signo)
371     {
372     }
373 
374     virtual ~StopInfoUnixSignal ()
375     {
376     }
377 
378 
379     virtual StopReason
380     GetStopReason () const
381     {
382         return eStopReasonSignal;
383     }
384 
385     virtual bool
386     ShouldStop (Event *event_ptr)
387     {
388         return m_thread.GetProcess().GetUnixSignals().GetShouldStop (m_value);
389     }
390 
391 
392     // If should stop returns false, check if we should notify of this event
393     virtual bool
394     ShouldNotify (Event *event_ptr)
395     {
396         return m_thread.GetProcess().GetUnixSignals().GetShouldNotify (m_value);
397     }
398 
399 
400     virtual void
401     WillResume (lldb::StateType resume_state)
402     {
403         if (m_thread.GetProcess().GetUnixSignals().GetShouldSuppress(m_value) == false)
404             m_thread.SetResumeSignal(m_value);
405     }
406 
407     virtual const char *
408     GetDescription ()
409     {
410         if (m_description.empty())
411         {
412             StreamString strm;
413             const char *signal_name = m_thread.GetProcess().GetUnixSignals().GetSignalAsCString (m_value);
414             if (signal_name)
415                 strm.Printf("signal %s", signal_name);
416             else
417                 strm.Printf("signal %lli", m_value);
418             m_description.swap (strm.GetString());
419         }
420         return m_description.c_str();
421     }
422 };
423 
424 //----------------------------------------------------------------------
425 // StopInfoTrace
426 //----------------------------------------------------------------------
427 
428 class StopInfoTrace : public StopInfo
429 {
430 public:
431 
432     StopInfoTrace (Thread &thread) :
433         StopInfo (thread, LLDB_INVALID_UID)
434     {
435     }
436 
437     virtual ~StopInfoTrace ()
438     {
439     }
440 
441     virtual StopReason
442     GetStopReason () const
443     {
444         return eStopReasonTrace;
445     }
446 
447     virtual const char *
448     GetDescription ()
449     {
450         if (m_description.empty())
451         return "trace";
452         else
453             return m_description.c_str();
454     }
455 };
456 
457 
458 //----------------------------------------------------------------------
459 // StopInfoException
460 //----------------------------------------------------------------------
461 
462 class StopInfoException : public StopInfo
463 {
464 public:
465 
466     StopInfoException (Thread &thread, const char *description) :
467         StopInfo (thread, LLDB_INVALID_UID)
468     {
469         if (description)
470             SetDescription (description);
471     }
472 
473     virtual
474     ~StopInfoException ()
475     {
476     }
477 
478     virtual StopReason
479     GetStopReason () const
480     {
481         return eStopReasonException;
482     }
483 
484     virtual const char *
485     GetDescription ()
486     {
487         if (m_description.empty())
488             return "exception";
489         else
490             return m_description.c_str();
491     }
492 };
493 
494 
495 //----------------------------------------------------------------------
496 // StopInfoThreadPlan
497 //----------------------------------------------------------------------
498 
499 class StopInfoThreadPlan : public StopInfo
500 {
501 public:
502 
503     StopInfoThreadPlan (ThreadPlanSP &plan_sp) :
504         StopInfo (plan_sp->GetThread(), LLDB_INVALID_UID),
505         m_plan_sp (plan_sp)
506     {
507     }
508 
509     virtual ~StopInfoThreadPlan ()
510     {
511     }
512 
513     virtual StopReason
514     GetStopReason () const
515     {
516         return eStopReasonPlanComplete;
517     }
518 
519     virtual const char *
520     GetDescription ()
521     {
522         if (m_description.empty())
523         {
524             StreamString strm;
525             m_plan_sp->GetDescription (&strm, eDescriptionLevelBrief);
526             m_description.swap (strm.GetString());
527         }
528         return m_description.c_str();
529     }
530 
531 private:
532     ThreadPlanSP m_plan_sp;
533 };
534 } // namespace lldb_private
535 
536 StopInfoSP
537 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id)
538 {
539     return StopInfoSP (new StopInfoBreakpoint (thread, break_id));
540 }
541 
542 StopInfoSP
543 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id, bool should_stop)
544 {
545     return StopInfoSP (new StopInfoBreakpoint (thread, break_id, should_stop));
546 }
547 
548 StopInfoSP
549 StopInfo::CreateStopReasonWithWatchpointID (Thread &thread, break_id_t watch_id)
550 {
551     return StopInfoSP (new StopInfoWatchpoint (thread, watch_id));
552 }
553 
554 StopInfoSP
555 StopInfo::CreateStopReasonWithSignal (Thread &thread, int signo)
556 {
557     return StopInfoSP (new StopInfoUnixSignal (thread, signo));
558 }
559 
560 StopInfoSP
561 StopInfo::CreateStopReasonToTrace (Thread &thread)
562 {
563     return StopInfoSP (new StopInfoTrace (thread));
564 }
565 
566 StopInfoSP
567 StopInfo::CreateStopReasonWithPlan (ThreadPlanSP &plan_sp)
568 {
569     return StopInfoSP (new StopInfoThreadPlan (plan_sp));
570 }
571 
572 StopInfoSP
573 StopInfo::CreateStopReasonWithException (Thread &thread, const char *description)
574 {
575     return StopInfoSP (new StopInfoException (thread, description));
576 }
577