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                                                                               eExecutionPolicyAlways,
198                                                                               discard_on_error,
199                                                                               bp_loc_sp->GetConditionText(),
200                                                                               NULL,
201                                                                               result_value_sp,
202                                                                               error);
203                         if (result_code == eExecutionCompleted)
204                         {
205                             if (result_value_sp)
206                             {
207                                 Scalar scalar_value;
208                                 if (result_value_sp->ResolveValue (scalar_value))
209                                 {
210                                     if (scalar_value.ULongLong(1) == 0)
211                                         m_should_stop = false;
212                                     else
213                                         m_should_stop = true;
214                                     if (log)
215                                         log->Printf("Condition successfully evaluated, result is %s.\n",
216                                                     m_should_stop ? "true" : "false");
217                                 }
218                                 else
219                                 {
220                                     m_should_stop = true;
221                                     if (log)
222                                         log->Printf("Failed to get an integer result from the expression.");
223                                 }
224                             }
225                         }
226                         else
227                         {
228                             Debugger &debugger = context.exe_ctx.target->GetDebugger();
229                             StreamSP error_sp = debugger.GetAsyncErrorStream ();
230                             error_sp->Printf ("Stopped due to an error evaluating condition of breakpoint ");
231                             bp_loc_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
232                             error_sp->Printf (": \"%s\"",
233                                               bp_loc_sp->GetConditionText());
234                             error_sp->EOL();
235                             const char *err_str = error.AsCString("<Unknown Error>");
236                             if (log)
237                                 log->Printf("Error evaluating condition: \"%s\"\n", err_str);
238 
239                             error_sp->PutCString (err_str);
240                             error_sp->EOL();
241                             error_sp->Flush();
242                             // If the condition fails to be parsed or run, we should stop.
243                             m_should_stop = true;
244                         }
245                     }
246 
247                     // If any condition says we should stop, then we're going to stop, so we don't need
248                     // to evaluate the others.
249                     if (m_should_stop)
250                         break;
251                 }
252             }
253         }
254         else
255         {
256             LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
257 
258             if (log)
259                 log->Printf ("Process::%s could not find breakpoint site id: %lld...", __FUNCTION__, m_value);
260         }
261         if (log)
262             log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
263     }
264 
265     virtual bool
266     ShouldNotify (Event *event_ptr)
267     {
268         BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
269         if (bp_site_sp)
270         {
271             bool all_internal = true;
272 
273             for (uint32_t i = 0; i < bp_site_sp->GetNumberOfOwners(); i++)
274             {
275                 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal())
276                 {
277                     all_internal = false;
278                     break;
279                 }
280             }
281             return all_internal == false;
282         }
283         return true;
284     }
285 
286     virtual const char *
287     GetDescription ()
288     {
289         if (m_description.empty())
290         {
291             BreakpointSiteSP bp_site_sp (m_thread.GetProcess().GetBreakpointSiteList().FindByID (m_value));
292             if (bp_site_sp)
293             {
294                 StreamString strm;
295                 strm.Printf("breakpoint ");
296                 bp_site_sp->GetDescription(&strm, eDescriptionLevelBrief);
297                 m_description.swap (strm.GetString());
298             }
299             else
300             {
301                 StreamString strm;
302                 strm.Printf("breakpoint site %lli", m_value);
303                 m_description.swap (strm.GetString());
304             }
305         }
306         return m_description.c_str();
307     }
308 
309 private:
310     std::string m_description;
311     bool m_should_stop;
312     bool m_should_stop_is_valid;
313     bool m_should_perform_action; // Since we are trying to preserve the "state" of the system even if we run functions
314                                   // etc. behind the users backs, we need to make sure we only REALLY perform the action once.
315 };
316 
317 
318 //----------------------------------------------------------------------
319 // StopInfoWatchpoint
320 //----------------------------------------------------------------------
321 
322 class StopInfoWatchpoint : public StopInfo
323 {
324 public:
325 
326     StopInfoWatchpoint (Thread &thread, break_id_t watch_id) :
327         StopInfo (thread, watch_id),
328         m_description()
329     {
330     }
331 
332     virtual ~StopInfoWatchpoint ()
333     {
334     }
335 
336     virtual StopReason
337     GetStopReason () const
338     {
339         return eStopReasonWatchpoint;
340     }
341 
342     virtual const char *
343     GetDescription ()
344     {
345         if (m_description.empty())
346         {
347             StreamString strm;
348             strm.Printf("watchpoint %lli", m_value);
349             m_description.swap (strm.GetString());
350         }
351         return m_description.c_str();
352     }
353 
354 
355 
356 private:
357     std::string m_description;
358 };
359 
360 
361 
362 //----------------------------------------------------------------------
363 // StopInfoUnixSignal
364 //----------------------------------------------------------------------
365 
366 class StopInfoUnixSignal : public StopInfo
367 {
368 public:
369 
370     StopInfoUnixSignal (Thread &thread, int signo) :
371         StopInfo (thread, signo)
372     {
373     }
374 
375     virtual ~StopInfoUnixSignal ()
376     {
377     }
378 
379 
380     virtual StopReason
381     GetStopReason () const
382     {
383         return eStopReasonSignal;
384     }
385 
386     virtual bool
387     ShouldStop (Event *event_ptr)
388     {
389         return m_thread.GetProcess().GetUnixSignals().GetShouldStop (m_value);
390     }
391 
392 
393     // If should stop returns false, check if we should notify of this event
394     virtual bool
395     ShouldNotify (Event *event_ptr)
396     {
397         return m_thread.GetProcess().GetUnixSignals().GetShouldNotify (m_value);
398     }
399 
400 
401     virtual void
402     WillResume (lldb::StateType resume_state)
403     {
404         if (m_thread.GetProcess().GetUnixSignals().GetShouldSuppress(m_value) == false)
405             m_thread.SetResumeSignal(m_value);
406     }
407 
408     virtual const char *
409     GetDescription ()
410     {
411         if (m_description.empty())
412         {
413             StreamString strm;
414             const char *signal_name = m_thread.GetProcess().GetUnixSignals().GetSignalAsCString (m_value);
415             if (signal_name)
416                 strm.Printf("signal %s", signal_name);
417             else
418                 strm.Printf("signal %lli", m_value);
419             m_description.swap (strm.GetString());
420         }
421         return m_description.c_str();
422     }
423 };
424 
425 //----------------------------------------------------------------------
426 // StopInfoTrace
427 //----------------------------------------------------------------------
428 
429 class StopInfoTrace : public StopInfo
430 {
431 public:
432 
433     StopInfoTrace (Thread &thread) :
434         StopInfo (thread, LLDB_INVALID_UID)
435     {
436     }
437 
438     virtual ~StopInfoTrace ()
439     {
440     }
441 
442     virtual StopReason
443     GetStopReason () const
444     {
445         return eStopReasonTrace;
446     }
447 
448     virtual const char *
449     GetDescription ()
450     {
451         if (m_description.empty())
452         return "trace";
453         else
454             return m_description.c_str();
455     }
456 };
457 
458 
459 //----------------------------------------------------------------------
460 // StopInfoException
461 //----------------------------------------------------------------------
462 
463 class StopInfoException : public StopInfo
464 {
465 public:
466 
467     StopInfoException (Thread &thread, const char *description) :
468         StopInfo (thread, LLDB_INVALID_UID)
469     {
470         if (description)
471             SetDescription (description);
472     }
473 
474     virtual
475     ~StopInfoException ()
476     {
477     }
478 
479     virtual StopReason
480     GetStopReason () const
481     {
482         return eStopReasonException;
483     }
484 
485     virtual const char *
486     GetDescription ()
487     {
488         if (m_description.empty())
489             return "exception";
490         else
491             return m_description.c_str();
492     }
493 };
494 
495 
496 //----------------------------------------------------------------------
497 // StopInfoThreadPlan
498 //----------------------------------------------------------------------
499 
500 class StopInfoThreadPlan : public StopInfo
501 {
502 public:
503 
504     StopInfoThreadPlan (ThreadPlanSP &plan_sp) :
505         StopInfo (plan_sp->GetThread(), LLDB_INVALID_UID),
506         m_plan_sp (plan_sp)
507     {
508     }
509 
510     virtual ~StopInfoThreadPlan ()
511     {
512     }
513 
514     virtual StopReason
515     GetStopReason () const
516     {
517         return eStopReasonPlanComplete;
518     }
519 
520     virtual const char *
521     GetDescription ()
522     {
523         if (m_description.empty())
524         {
525             StreamString strm;
526             m_plan_sp->GetDescription (&strm, eDescriptionLevelBrief);
527             m_description.swap (strm.GetString());
528         }
529         return m_description.c_str();
530     }
531 
532 private:
533     ThreadPlanSP m_plan_sp;
534 };
535 } // namespace lldb_private
536 
537 StopInfoSP
538 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id)
539 {
540     return StopInfoSP (new StopInfoBreakpoint (thread, break_id));
541 }
542 
543 StopInfoSP
544 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id, bool should_stop)
545 {
546     return StopInfoSP (new StopInfoBreakpoint (thread, break_id, should_stop));
547 }
548 
549 StopInfoSP
550 StopInfo::CreateStopReasonWithWatchpointID (Thread &thread, break_id_t watch_id)
551 {
552     return StopInfoSP (new StopInfoWatchpoint (thread, watch_id));
553 }
554 
555 StopInfoSP
556 StopInfo::CreateStopReasonWithSignal (Thread &thread, int signo)
557 {
558     return StopInfoSP (new StopInfoUnixSignal (thread, signo));
559 }
560 
561 StopInfoSP
562 StopInfo::CreateStopReasonToTrace (Thread &thread)
563 {
564     return StopInfoSP (new StopInfoTrace (thread));
565 }
566 
567 StopInfoSP
568 StopInfo::CreateStopReasonWithPlan (ThreadPlanSP &plan_sp)
569 {
570     return StopInfoSP (new StopInfoThreadPlan (plan_sp));
571 }
572 
573 StopInfoSP
574 StopInfo::CreateStopReasonWithException (Thread &thread, const char *description)
575 {
576     return StopInfoSP (new StopInfoException (thread, description));
577 }
578