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();
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 ()
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         ProcessSP process_sp (m_thread.GetProcess());
278         const ABI *abi = process_sp ? process_sp->GetABI().get() : NULL;
279         if (abi && m_return_type.IsValid())
280         {
281             const bool persistent = false;
282             m_return_valobj_sp = abi->GetReturnValueObject (m_thread, m_return_type, persistent);
283         }
284 
285         if (log)
286             log->Printf ("ThreadPlanCallFunction(%p): DoTakedown called for thread 0x%4.4llx, m_valid: %d complete: %d.\n", this, m_thread.GetID(), m_valid, IsPlanComplete());
287         m_takedown_done = true;
288         m_stop_address = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
289         m_real_stop_info_sp = GetPrivateStopReason();
290         m_thread.RestoreThreadStateFromCheckpoint(m_stored_thread_state);
291         SetPlanComplete();
292         ClearBreakpoints();
293         if (log && log->GetVerbose())
294             ReportRegisterState ("Restoring thread state after function call.  Restored register state:");
295 
296     }
297     else
298     {
299         if (log)
300             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());
301     }
302 }
303 
304 void
305 ThreadPlanCallFunction::WillPop ()
306 {
307     DoTakedown();
308 }
309 
310 void
311 ThreadPlanCallFunction::GetDescription (Stream *s, DescriptionLevel level)
312 {
313     if (level == eDescriptionLevelBrief)
314     {
315         s->Printf("Function call thread plan");
316     }
317     else
318     {
319         TargetSP target_sp (m_thread.CalculateTarget());
320         s->Printf("Thread plan to call 0x%llx", m_function_addr.GetLoadAddress(target_sp.get()));
321     }
322 }
323 
324 bool
325 ThreadPlanCallFunction::ValidatePlan (Stream *error)
326 {
327     if (!m_valid)
328         return false;
329 
330     return true;
331 }
332 
333 bool
334 ThreadPlanCallFunction::PlanExplainsStop ()
335 {
336     m_real_stop_info_sp = GetPrivateStopReason();
337 
338     // If our subplan knows why we stopped, even if it's done (which would forward the question to us)
339     // we answer yes.
340     if (m_subplan_sp.get() != NULL && m_subplan_sp->PlanExplainsStop())
341         return true;
342 
343     // Check if the breakpoint is one of ours.
344 
345     if (BreakpointsExplainStop())
346         return true;
347 
348     // If we don't want to discard this plan, than any stop we don't understand should be propagated up the stack.
349     if (!OkayToDiscard())
350         return false;
351 
352     // Otherwise, check the case where we stopped for an internal breakpoint, in that case, continue on.
353     // If it is not an internal breakpoint, consult OkayToDiscard.
354 
355     if (m_real_stop_info_sp && m_real_stop_info_sp->GetStopReason() == eStopReasonBreakpoint)
356     {
357         ProcessSP process_sp (m_thread.CalculateProcess());
358         uint64_t break_site_id = m_real_stop_info_sp->GetValue();
359         BreakpointSiteSP bp_site_sp;
360         if (process_sp)
361             bp_site_sp = process_sp->GetBreakpointSiteList().FindByID(break_site_id);
362         if (bp_site_sp)
363         {
364             uint32_t num_owners = bp_site_sp->GetNumberOfOwners();
365             bool is_internal = true;
366             for (uint32_t i = 0; i < num_owners; i++)
367             {
368                 Breakpoint &bp = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint();
369 
370                 if (!bp.IsInternal())
371                 {
372                     is_internal = false;
373                     break;
374                 }
375             }
376             if (is_internal)
377                 return false;
378         }
379 
380         return OkayToDiscard();
381     }
382     else
383     {
384         // If the subplan is running, any crashes are attributable to us.
385         // If we want to discard the plan, then we say we explain the stop
386         // but if we are going to be discarded, let whoever is above us
387         // explain the stop.
388         return ((m_subplan_sp.get() != NULL) && !OkayToDiscard());
389     }
390 }
391 
392 bool
393 ThreadPlanCallFunction::ShouldStop (Event *event_ptr)
394 {
395     if (PlanExplainsStop())
396     {
397         ReportRegisterState ("Function completed.  Register state was:");
398 
399         DoTakedown();
400 
401         return true;
402     }
403     else
404     {
405         return false;
406     }
407 }
408 
409 bool
410 ThreadPlanCallFunction::StopOthers ()
411 {
412     return m_stop_other_threads;
413 }
414 
415 void
416 ThreadPlanCallFunction::SetStopOthers (bool new_value)
417 {
418     if (m_subplan_sp)
419     {
420         ThreadPlanRunToAddress *address_plan = static_cast<ThreadPlanRunToAddress *>(m_subplan_sp.get());
421         address_plan->SetStopOthers(new_value);
422     }
423     m_stop_other_threads = new_value;
424 }
425 
426 StateType
427 ThreadPlanCallFunction::GetPlanRunState ()
428 {
429     return eStateRunning;
430 }
431 
432 void
433 ThreadPlanCallFunction::DidPush ()
434 {
435 //#define SINGLE_STEP_EXPRESSIONS
436 
437 #ifndef SINGLE_STEP_EXPRESSIONS
438     m_subplan_sp.reset(new ThreadPlanRunToAddress(m_thread, m_start_addr, m_stop_other_threads));
439 
440     m_thread.QueueThreadPlan(m_subplan_sp, false);
441     m_subplan_sp->SetPrivate (true);
442 #endif
443 }
444 
445 bool
446 ThreadPlanCallFunction::WillStop ()
447 {
448     return true;
449 }
450 
451 bool
452 ThreadPlanCallFunction::MischiefManaged ()
453 {
454     if (IsPlanComplete())
455     {
456         LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
457 
458         if (log)
459             log->Printf("ThreadPlanCallFunction(%p): Completed call function plan.", this);
460 
461         ThreadPlan::MischiefManaged ();
462         return true;
463     }
464     else
465     {
466         return false;
467     }
468 }
469 
470 void
471 ThreadPlanCallFunction::SetBreakpoints ()
472 {
473     ProcessSP process_sp (m_thread.CalculateProcess());
474     if (process_sp)
475     {
476         m_cxx_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeC_plus_plus);
477         m_objc_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeObjC);
478 
479         if (m_cxx_language_runtime)
480             m_cxx_language_runtime->SetExceptionBreakpoints();
481         if (m_objc_language_runtime)
482             m_objc_language_runtime->SetExceptionBreakpoints();
483     }
484 }
485 
486 void
487 ThreadPlanCallFunction::ClearBreakpoints ()
488 {
489     if (m_cxx_language_runtime)
490         m_cxx_language_runtime->ClearExceptionBreakpoints();
491     if (m_objc_language_runtime)
492         m_objc_language_runtime->ClearExceptionBreakpoints();
493 }
494 
495 bool
496 ThreadPlanCallFunction::BreakpointsExplainStop()
497 {
498     StopInfoSP stop_info_sp = GetPrivateStopReason();
499 
500     if (m_cxx_language_runtime &&
501         m_cxx_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
502         return true;
503 
504     if (m_objc_language_runtime &&
505         m_objc_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
506         return true;
507 
508     return false;
509 }
510