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::GetLogIfAllCategoriesSet (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 ("Trying to put the stack in unreadable memory at: 0x%llx.", 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 ("Can't execute code without an executable module.");
82         return false;
83     }
84     else
85     {
86         ObjectFile *objectFile = exe_module->GetObjectFile();
87         if (!objectFile)
88         {
89             if (log)
90                 log->Printf ("Could not find object file for module \"%s\".",
91                              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 ("Could not find entry point address for executable module \"%s\".",
99                              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 ("Setting up ThreadPlanCallFunction, failed to checkpoint thread state.");
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::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
266     if (!m_takedown_done)
267     {
268         ProcessSP process_sp (m_thread.GetProcess());
269         const ABI *abi = process_sp ? process_sp->GetABI().get() : NULL;
270         if (abi && m_return_type.IsValid())
271         {
272             const bool persistent = false;
273             m_return_valobj_sp = abi->GetReturnValueObject (m_thread, m_return_type, persistent);
274         }
275 
276         if (log)
277             log->Printf ("DoTakedown called for thread 0x%4.4llx, m_valid: %d complete: %d.\n", m_thread.GetID(), m_valid, IsPlanComplete());
278         m_takedown_done = true;
279         m_stop_address = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
280         m_real_stop_info_sp = GetPrivateStopReason();
281         m_thread.RestoreThreadStateFromCheckpoint(m_stored_thread_state);
282         SetPlanComplete();
283         ClearBreakpoints();
284         if (log && log->GetVerbose())
285             ReportRegisterState ("Restoring thread state after function call.  Restored register state:");
286 
287     }
288     else
289     {
290         if (log)
291             log->Printf ("DoTakedown called as no-op for thread 0x%4.4llx, m_valid: %d complete: %d.\n", m_thread.GetID(), m_valid, IsPlanComplete());
292     }
293 }
294 
295 void
296 ThreadPlanCallFunction::WillPop ()
297 {
298     DoTakedown();
299 }
300 
301 void
302 ThreadPlanCallFunction::GetDescription (Stream *s, DescriptionLevel level)
303 {
304     if (level == eDescriptionLevelBrief)
305     {
306         s->Printf("Function call thread plan");
307     }
308     else
309     {
310         TargetSP target_sp (m_thread.CalculateTarget());
311         s->Printf("Thread plan to call 0x%llx", m_function_addr.GetLoadAddress(target_sp.get()));
312     }
313 }
314 
315 bool
316 ThreadPlanCallFunction::ValidatePlan (Stream *error)
317 {
318     if (!m_valid)
319         return false;
320 
321     return true;
322 }
323 
324 bool
325 ThreadPlanCallFunction::PlanExplainsStop ()
326 {
327     m_real_stop_info_sp = GetPrivateStopReason();
328 
329     // If our subplan knows why we stopped, even if it's done (which would forward the question to us)
330     // we answer yes.
331     if (m_subplan_sp.get() != NULL && m_subplan_sp->PlanExplainsStop())
332         return true;
333 
334     // Check if the breakpoint is one of ours.
335 
336     if (BreakpointsExplainStop())
337         return true;
338 
339     // If we don't want to discard this plan, than any stop we don't understand should be propagated up the stack.
340     if (!OkayToDiscard())
341         return false;
342 
343     // Otherwise, check the case where we stopped for an internal breakpoint, in that case, continue on.
344     // If it is not an internal breakpoint, consult OkayToDiscard.
345 
346     if (m_real_stop_info_sp && m_real_stop_info_sp->GetStopReason() == eStopReasonBreakpoint)
347     {
348         ProcessSP process_sp (m_thread.CalculateProcess());
349         uint64_t break_site_id = m_real_stop_info_sp->GetValue();
350         BreakpointSiteSP bp_site_sp;
351         if (process_sp)
352             bp_site_sp = process_sp->GetBreakpointSiteList().FindByID(break_site_id);
353         if (bp_site_sp)
354         {
355             uint32_t num_owners = bp_site_sp->GetNumberOfOwners();
356             bool is_internal = true;
357             for (uint32_t i = 0; i < num_owners; i++)
358             {
359                 Breakpoint &bp = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint();
360 
361                 if (!bp.IsInternal())
362                 {
363                     is_internal = false;
364                     break;
365                 }
366             }
367             if (is_internal)
368                 return false;
369         }
370 
371         return OkayToDiscard();
372     }
373     else
374     {
375         // If the subplan is running, any crashes are attributable to us.
376         // If we want to discard the plan, then we say we explain the stop
377         // but if we are going to be discarded, let whoever is above us
378         // explain the stop.
379         return ((m_subplan_sp.get() != NULL) && !OkayToDiscard());
380     }
381 }
382 
383 bool
384 ThreadPlanCallFunction::ShouldStop (Event *event_ptr)
385 {
386     if (PlanExplainsStop())
387     {
388         ReportRegisterState ("Function completed.  Register state was:");
389 
390         DoTakedown();
391 
392         return true;
393     }
394     else
395     {
396         return false;
397     }
398 }
399 
400 bool
401 ThreadPlanCallFunction::StopOthers ()
402 {
403     return m_stop_other_threads;
404 }
405 
406 void
407 ThreadPlanCallFunction::SetStopOthers (bool new_value)
408 {
409     if (m_subplan_sp)
410     {
411         ThreadPlanRunToAddress *address_plan = static_cast<ThreadPlanRunToAddress *>(m_subplan_sp.get());
412         address_plan->SetStopOthers(new_value);
413     }
414     m_stop_other_threads = new_value;
415 }
416 
417 StateType
418 ThreadPlanCallFunction::GetPlanRunState ()
419 {
420     return eStateRunning;
421 }
422 
423 void
424 ThreadPlanCallFunction::DidPush ()
425 {
426 //#define SINGLE_STEP_EXPRESSIONS
427 
428 #ifndef SINGLE_STEP_EXPRESSIONS
429     m_subplan_sp.reset(new ThreadPlanRunToAddress(m_thread, m_start_addr, m_stop_other_threads));
430 
431     m_thread.QueueThreadPlan(m_subplan_sp, false);
432     m_subplan_sp->SetPrivate (true);
433 #endif
434 }
435 
436 bool
437 ThreadPlanCallFunction::WillStop ()
438 {
439     return true;
440 }
441 
442 bool
443 ThreadPlanCallFunction::MischiefManaged ()
444 {
445     if (IsPlanComplete())
446     {
447         LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
448 
449         if (log)
450             log->Printf("Completed call function plan.");
451 
452         ThreadPlan::MischiefManaged ();
453         return true;
454     }
455     else
456     {
457         return false;
458     }
459 }
460 
461 void
462 ThreadPlanCallFunction::SetBreakpoints ()
463 {
464     ProcessSP process_sp (m_thread.CalculateProcess());
465     if (process_sp)
466     {
467         m_cxx_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeC_plus_plus);
468         m_objc_language_runtime = process_sp->GetLanguageRuntime(eLanguageTypeObjC);
469 
470         if (m_cxx_language_runtime)
471             m_cxx_language_runtime->SetExceptionBreakpoints();
472         if (m_objc_language_runtime)
473             m_objc_language_runtime->SetExceptionBreakpoints();
474     }
475 }
476 
477 void
478 ThreadPlanCallFunction::ClearBreakpoints ()
479 {
480     if (m_cxx_language_runtime)
481         m_cxx_language_runtime->ClearExceptionBreakpoints();
482     if (m_objc_language_runtime)
483         m_objc_language_runtime->ClearExceptionBreakpoints();
484 }
485 
486 bool
487 ThreadPlanCallFunction::BreakpointsExplainStop()
488 {
489     StopInfoSP stop_info_sp = GetPrivateStopReason();
490 
491     if (m_cxx_language_runtime &&
492         m_cxx_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
493         return true;
494 
495     if (m_objc_language_runtime &&
496         m_objc_language_runtime->ExceptionBreakpointsExplainStop(stop_info_sp))
497         return true;
498 
499     return false;
500 }
501