1 //===-- ThreadPlanCallFunction.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/ThreadPlanCallFunction.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 #include "llvm/Support/MachO.h"
16 // Project includes
17 #include "lldb/lldb-private-log.h"
18 #include "lldb/Breakpoint/Breakpoint.h"
19 #include "lldb/Breakpoint/BreakpointLocation.h"
20 #include "lldb/Core/Address.h"
21 #include "lldb/Core/Log.h"
22 #include "lldb/Core/Stream.h"
23 #include "lldb/Target/LanguageRuntime.h"
24 #include "lldb/Target/Process.h"
25 #include "lldb/Target/RegisterContext.h"
26 #include "lldb/Target/StopInfo.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/Thread.h"
29 #include "lldb/Target/ThreadPlanRunToAddress.h"
30 
31 using namespace lldb;
32 using namespace lldb_private;
33 
34 //----------------------------------------------------------------------
35 // ThreadPlanCallFunction: Plan to call a single function
36 //----------------------------------------------------------------------
37 bool
38 ThreadPlanCallFunction::ConstructorSetup (Thread &thread,
39                                           bool discard_on_error,
40                                           ABI *& abi,
41                                           lldb::addr_t &start_load_addr,
42                                           lldb::addr_t &function_load_addr)
43 {
44     // Call function thread plans need to be master plans so that they can potentially stay on the stack when
45     // a breakpoint is hit during the function call.
46     SetIsMasterPlan (true);
47     SetOkayToDiscard (discard_on_error);
48 
49     ProcessSP process_sp (thread.GetProcess());
50     if (!process_sp)
51         return false;
52 
53     abi = process_sp->GetABI().get();
54 
55     if (!abi)
56         return false;
57 
58     TargetSP target_sp (thread.CalculateTarget());
59 
60     LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
61 
62     SetBreakpoints();
63 
64     m_function_sp = thread.GetRegisterContext()->GetSP() - abi->GetRedZoneSize();
65     // If we can't read memory at the point of the process where we are planning to put our function, we're
66     // not going to get any further...
67     Error error;
68     process_sp->ReadUnsignedIntegerFromMemory(m_function_sp, 4, 0, error);
69     if (!error.Success())
70     {
71         if (log)
72             log->Printf ("ThreadPlanCallFunction(%p): Trying to put the stack in unreadable memory at: 0x%llx.", this, m_function_sp);
73         return false;
74     }
75 
76     Module *exe_module = target_sp->GetExecutableModulePointer();
77 
78     if (exe_module == NULL)
79     {
80         if (log)
81             log->Printf ("ThreadPlanCallFunction(%p): Can't execute code without an executable module.", this);
82         return false;
83     }
84     else
85     {
86         ObjectFile *objectFile = exe_module->GetObjectFile();
87         if (!objectFile)
88         {
89             if (log)
90                 log->Printf ("ThreadPlanCallFunction(%p): Could not find object file for module \"%s\".",
91                              this, exe_module->GetFileSpec().GetFilename().AsCString());
92             return false;
93         }
94         m_start_addr = objectFile->GetEntryPointAddress();
95         if (!m_start_addr.IsValid())
96         {
97             if (log)
98                 log->Printf ("ThreadPlanCallFunction(%p): Could not find entry point address for executable module \"%s\".",
99                              this, exe_module->GetFileSpec().GetFilename().AsCString());
100             return false;
101         }
102     }
103 
104     start_load_addr = m_start_addr.GetLoadAddress (target_sp.get());
105 
106     // Checkpoint the thread state so we can restore it later.
107     if (log && log->GetVerbose())
108         ReportRegisterState ("About to checkpoint thread before function call.  Original register state was:");
109 
110     if (!thread.CheckpointThreadState (m_stored_thread_state))
111     {
112         if (log)
113             log->Printf ("ThreadPlanCallFunction(%p): Setting up ThreadPlanCallFunction, failed to checkpoint thread state.", this);
114         return false;
115     }
116     // Now set the thread state to "no reason" so we don't run with whatever signal was outstanding...
117     thread.SetStopInfoToNothing();
118 
119     function_load_addr = m_function_addr.GetLoadAddress (target_sp.get());
120 
121     return true;
122 }
123 
124 ThreadPlanCallFunction::ThreadPlanCallFunction (Thread &thread,
125                                                 Address &function,
126                                                 const ClangASTType &return_type,
127                                                 addr_t arg,
128                                                 bool stop_other_threads,
129                                                 bool discard_on_error,
130                                                 addr_t *this_arg,
131                                                 addr_t *cmd_arg) :
132     ThreadPlan (ThreadPlan::eKindCallFunction, "Call function plan", thread, eVoteNoOpinion, eVoteNoOpinion),
133     m_valid (false),
134     m_stop_other_threads (stop_other_threads),
135     m_function_addr (function),
136     m_function_sp (NULL),
137     m_return_type (return_type),
138     m_takedown_done (false),
139     m_stop_address (LLDB_INVALID_ADDRESS)
140 {
141     lldb::addr_t start_load_addr;
142     ABI *abi;
143     lldb::addr_t function_load_addr;
144     if (!ConstructorSetup (thread, discard_on_error, abi, start_load_addr, function_load_addr))
145         return;
146 
147     if (this_arg && cmd_arg)
148     {
149         if (!abi->PrepareTrivialCall (thread,
150                                       m_function_sp,
151                                       function_load_addr,
152                                       start_load_addr,
153                                       this_arg,
154                                       cmd_arg,
155                                       &arg))
156             return;
157     }
158     else if (this_arg)
159     {
160         if (!abi->PrepareTrivialCall (thread,
161                                       m_function_sp,
162                                       function_load_addr,
163                                       start_load_addr,
164                                       this_arg,
165                                       &arg))
166             return;
167     }
168     else
169     {
170         if (!abi->PrepareTrivialCall (thread,
171                                       m_function_sp,
172                                       function_load_addr,
173                                       start_load_addr,
174                                       &arg))
175             return;
176     }
177 
178     ReportRegisterState ("Function call was set up.  Register state was:");
179 
180     m_valid = true;
181 }
182 
183 
184 ThreadPlanCallFunction::ThreadPlanCallFunction (Thread &thread,
185                                                 Address &function,
186                                                 const ClangASTType &return_type,
187                                                 bool stop_other_threads,
188                                                 bool discard_on_error,
189                                                 addr_t *arg1_ptr,
190                                                 addr_t *arg2_ptr,
191                                                 addr_t *arg3_ptr,
192                                                 addr_t *arg4_ptr,
193                                                 addr_t *arg5_ptr,
194                                                 addr_t *arg6_ptr) :
195     ThreadPlan (ThreadPlan::eKindCallFunction, "Call function plan", thread, eVoteNoOpinion, eVoteNoOpinion),
196     m_valid (false),
197     m_stop_other_threads (stop_other_threads),
198     m_function_addr (function),
199     m_function_sp(NULL),
200     m_return_type (return_type),
201     m_takedown_done (false),
202     m_stop_address (LLDB_INVALID_ADDRESS)
203 {
204     lldb::addr_t start_load_addr;
205     ABI *abi;
206     lldb::addr_t function_load_addr;
207     if (!ConstructorSetup (thread, discard_on_error, abi, start_load_addr, function_load_addr))
208         return;
209 
210     if (!abi->PrepareTrivialCall (thread,
211                                   m_function_sp,
212                                   function_load_addr,
213                                   start_load_addr,
214                                   arg1_ptr,
215                                   arg2_ptr,
216                                   arg3_ptr,
217                                   arg4_ptr,
218                                   arg5_ptr,
219                                   arg6_ptr))
220     {
221             return;
222     }
223 
224     ReportRegisterState ("Function call was set up.  Register state was:");
225 
226     m_valid = true;
227 }
228 
229 ThreadPlanCallFunction::~ThreadPlanCallFunction ()
230 {
231     DoTakedown(true);
232 }
233 
234 void
235 ThreadPlanCallFunction::ReportRegisterState (const char *message)
236 {
237     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP | LIBLLDB_LOG_VERBOSE));
238     if (log)
239     {
240         StreamString strm;
241         RegisterContext *reg_ctx = m_thread.GetRegisterContext().get();
242 
243         log->PutCString(message);
244 
245         RegisterValue reg_value;
246 
247         for (uint32_t reg_idx = 0, num_registers = reg_ctx->GetRegisterCount();
248              reg_idx < num_registers;
249              ++reg_idx)
250         {
251             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex (reg_idx);
252             if (reg_ctx->ReadRegister(reg_info, reg_value))
253             {
254                 reg_value.Dump(&strm, reg_info, true, false, eFormatDefault);
255                 strm.EOL();
256             }
257         }
258         log->PutCString(strm.GetData());
259     }
260 }
261 
262 void
263 ThreadPlanCallFunction::DoTakedown (bool success)
264 {
265     LogSP log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_STEP));
266 
267     if (!m_valid)
268     {
269         //Don't call DoTakedown if we were never valid to begin with.
270         if (log)
271             log->Printf ("ThreadPlanCallFunction(%p): Log called on ThreadPlanCallFunction that was never valid.", this);
272         return;
273     }
274 
275     if (!m_takedown_done)
276     {
277         if (success)
278         {
279             ProcessSP process_sp (m_thread.GetProcess());
280             const ABI *abi = process_sp ? process_sp->GetABI().get() : NULL;
281             if (abi && m_return_type.IsValid())
282             {
283                 const bool persistent = false;
284                 m_return_valobj_sp = abi->GetReturnValueObject (m_thread, m_return_type, persistent);
285             }
286         }
287         if (log)
288             log->Printf ("ThreadPlanCallFunction(%p): DoTakedown called for thread 0x%4.4llx, m_valid: %d complete: %d.\n", this, m_thread.GetID(), m_valid, IsPlanComplete());
289         m_takedown_done = true;
290         m_stop_address = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
291         m_real_stop_info_sp = GetPrivateStopReason();
292         m_thread.RestoreThreadStateFromCheckpoint(m_stored_thread_state);
293         SetPlanComplete(success);
294         ClearBreakpoints();
295         if (log && log->GetVerbose())
296             ReportRegisterState ("Restoring thread state after function call.  Restored register state:");
297 
298     }
299     else
300     {
301         if (log)
302             log->Printf ("ThreadPlanCallFunction(%p): DoTakedown called as no-op for thread 0x%4.4llx, m_valid: %d complete: %d.\n", this, m_thread.GetID(), m_valid, IsPlanComplete());
303     }
304 }
305 
306 void
307 ThreadPlanCallFunction::WillPop ()
308 {
309     DoTakedown(true);
310 }
311 
312 void
313 ThreadPlanCallFunction::GetDescription (Stream *s, DescriptionLevel level)
314 {
315     if (level == eDescriptionLevelBrief)
316     {
317         s->Printf("Function call thread plan");
318     }
319     else
320     {
321         TargetSP target_sp (m_thread.CalculateTarget());
322         s->Printf("Thread plan to call 0x%llx", m_function_addr.GetLoadAddress(target_sp.get()));
323     }
324 }
325 
326 bool
327 ThreadPlanCallFunction::ValidatePlan (Stream *error)
328 {
329     if (!m_valid)
330         return false;
331 
332     return true;
333 }
334 
335 bool
336 ThreadPlanCallFunction::PlanExplainsStop ()
337 {
338     m_real_stop_info_sp = GetPrivateStopReason();
339 
340     // If our subplan knows why we stopped, even if it's done (which would forward the question to us)
341     // we answer yes.
342     if (m_subplan_sp.get() != NULL && m_subplan_sp->PlanExplainsStop())
343         return true;
344 
345     // Check if the breakpoint is one of ours.
346 
347     StopReason stop_reason;
348     if (!m_real_stop_info_sp)
349         stop_reason = eStopReasonNone;
350     else
351         stop_reason = m_real_stop_info_sp->GetStopReason();
352 
353     if (stop_reason == eStopReasonBreakpoint && BreakpointsExplainStop())
354         return true;
355 
356     // If we don't want to discard this plan, than any stop we don't understand should be propagated up the stack.
357     if (!OkayToDiscard())
358         return false;
359 
360     // Otherwise, check the case where we stopped for an internal breakpoint, in that case, continue on.
361     // If it is not an internal breakpoint, consult OkayToDiscard.
362 
363 
364     if (stop_reason == eStopReasonBreakpoint)
365     {
366         ProcessSP process_sp (m_thread.CalculateProcess());
367         uint64_t break_site_id = m_real_stop_info_sp->GetValue();
368         BreakpointSiteSP bp_site_sp;
369         if (process_sp)
370             bp_site_sp = process_sp->GetBreakpointSiteList().FindByID(break_site_id);
371         if (bp_site_sp)
372         {
373             uint32_t num_owners = bp_site_sp->GetNumberOfOwners();
374             bool is_internal = true;
375             for (uint32_t i = 0; i < num_owners; i++)
376             {
377                 Breakpoint &bp = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint();
378 
379                 if (!bp.IsInternal())
380                 {
381                     is_internal = false;
382                     break;
383                 }
384             }
385             if (is_internal)
386                 return false;
387         }
388 
389         return OkayToDiscard();
390     }
391     else
392     {
393         // If the subplan is running, any crashes are attributable to us.
394         // If we want to discard the plan, then we say we explain the stop
395         // but if we are going to be discarded, let whoever is above us
396         // explain the stop.
397         if (m_subplan_sp != NULL)
398         {
399             if (OkayToDiscard())
400             {
401                 DoTakedown(false);
402                 return true;
403             }
404             else
405                 return false;
406         }
407         else
408             return false;
409     }
410 }
411 
412 bool
413 ThreadPlanCallFunction::ShouldStop (Event *event_ptr)
414 {
415     if (PlanExplainsStop())
416     {
417         ReportRegisterState ("Function completed.  Register state was:");
418 
419         DoTakedown(true);
420 
421         return true;
422     }
423     else
424     {
425         return false;
426     }
427 }
428 
429 bool
430 ThreadPlanCallFunction::StopOthers ()
431 {
432     return m_stop_other_threads;
433 }
434 
435 void
436 ThreadPlanCallFunction::SetStopOthers (bool new_value)
437 {
438     if (m_subplan_sp)
439     {
440         ThreadPlanRunToAddress *address_plan = static_cast<ThreadPlanRunToAddress *>(m_subplan_sp.get());
441         address_plan->SetStopOthers(new_value);
442     }
443     m_stop_other_threads = new_value;
444 }
445 
446 StateType
447 ThreadPlanCallFunction::GetPlanRunState ()
448 {
449     return eStateRunning;
450 }
451 
452 void
453 ThreadPlanCallFunction::DidPush ()
454 {
455 //#define SINGLE_STEP_EXPRESSIONS
456 
457 #ifndef SINGLE_STEP_EXPRESSIONS
458     m_subplan_sp.reset(new ThreadPlanRunToAddress(m_thread, m_start_addr, m_stop_other_threads));
459 
460     m_thread.QueueThreadPlan(m_subplan_sp, false);
461     m_subplan_sp->SetPrivate (true);
462 #endif
463 }
464 
465 bool
466 ThreadPlanCallFunction::WillStop ()
467 {
468     return true;
469 }
470 
471 bool
472 ThreadPlanCallFunction::MischiefManaged ()
473 {
474     if (IsPlanComplete())
475     {
476         LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
477 
478         if (log)
479             log->Printf("ThreadPlanCallFunction(%p): Completed call function plan.", this);
480 
481         ThreadPlan::MischiefManaged ();
482         return true;
483     }
484     else
485     {
486         return false;
487     }
488 }
489 
490 void
491 ThreadPlanCallFunction::SetBreakpoints ()
492 {
493     ProcessSP process_sp (m_thread.CalculateProcess());
494     if (process_sp)
495     {
496         m_cxx_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeC_plus_plus);
497         m_objc_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeObjC);
498 
499         if (m_cxx_language_runtime)
500             m_cxx_language_runtime->SetExceptionBreakpoints();
501         if (m_objc_language_runtime)
502             m_objc_language_runtime->SetExceptionBreakpoints();
503     }
504 }
505 
506 void
507 ThreadPlanCallFunction::ClearBreakpoints ()
508 {
509     if (m_cxx_language_runtime)
510         m_cxx_language_runtime->ClearExceptionBreakpoints();
511     if (m_objc_language_runtime)
512         m_objc_language_runtime->ClearExceptionBreakpoints();
513 }
514 
515 bool
516 ThreadPlanCallFunction::BreakpointsExplainStop()
517 {
518     StopInfoSP stop_info_sp = GetPrivateStopReason();
519 
520     if (m_cxx_language_runtime &&
521         m_cxx_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
522         return true;
523 
524     if (m_objc_language_runtime &&
525         m_objc_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
526         return true;
527 
528     return false;
529 }
530