1 //===-- UnwindAssemblyInstEmulation.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 "UnwindAssemblyInstEmulation.h"
11
12 #include "lldb/Core/Address.h"
13 #include "lldb/Core/ArchSpec.h"
14 #include "lldb/Core/DataBufferHeap.h"
15 #include "lldb/Core/DataExtractor.h"
16 #include "lldb/Core/Disassembler.h"
17 #include "lldb/Core/Error.h"
18 #include "lldb/Core/FormatEntity.h"
19 #include "lldb/Core/Log.h"
20 #include "lldb/Core/PluginManager.h"
21 #include "lldb/Core/StreamString.h"
22 #include "lldb/Target/ExecutionContext.h"
23 #include "lldb/Target/Process.h"
24 #include "lldb/Target/Thread.h"
25 #include "lldb/Target/Target.h"
26
27 using namespace lldb;
28 using namespace lldb_private;
29
30
31
32 //-----------------------------------------------------------------------------------------------
33 // UnwindAssemblyInstEmulation method definitions
34 //-----------------------------------------------------------------------------------------------
35
36 bool
GetNonCallSiteUnwindPlanFromAssembly(AddressRange & range,Thread & thread,UnwindPlan & unwind_plan)37 UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range,
38 Thread& thread,
39 UnwindPlan& unwind_plan)
40 {
41 if (range.GetByteSize() > 0 &&
42 range.GetBaseAddress().IsValid() &&
43 m_inst_emulator_ap.get())
44 {
45
46 // The instruction emulation subclass setup the unwind plan for the
47 // first instruction.
48 m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan);
49
50 // CreateFunctionEntryUnwind should have created the first row. If it
51 // doesn't, then we are done.
52 if (unwind_plan.GetRowCount() == 0)
53 return false;
54
55 ExecutionContext exe_ctx;
56 thread.CalculateExecutionContext(exe_ctx);
57 const bool prefer_file_cache = true;
58 DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch,
59 NULL,
60 NULL,
61 exe_ctx,
62 range,
63 prefer_file_cache));
64
65 Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
66
67 if (disasm_sp)
68 {
69
70 m_range_ptr = ⦥
71 m_thread_ptr = &thread;
72 m_unwind_plan_ptr = &unwind_plan;
73
74 const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
75 const bool show_address = true;
76 const bool show_bytes = true;
77 m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(),
78 unwind_plan.GetInitialCFARegister(),
79 m_cfa_reg_info);
80
81 m_fp_is_cfa = false;
82 m_register_values.clear();
83 m_pushed_regs.clear();
84
85 // Initialize the CFA with a known value. In the 32 bit case
86 // it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
87 // We use the address byte size to be safe for any future address sizes
88 m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
89 RegisterValue cfa_reg_value;
90 cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size);
91 SetRegisterValue (m_cfa_reg_info, cfa_reg_value);
92
93 const InstructionList &inst_list = disasm_sp->GetInstructionList ();
94 const size_t num_instructions = inst_list.GetSize();
95
96 if (num_instructions > 0)
97 {
98 Instruction *inst = inst_list.GetInstructionAtIndex (0).get();
99 const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress();
100
101 // Map for storing the unwind plan row and the value of the registers at a given offset.
102 // When we see a forward branch we add a new entry to this map with the actual unwind plan
103 // row and register context for the target address of the branch as the current data have
104 // to be valid for the target address of the branch too if we are in the same function.
105 std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>> saved_unwind_states;
106
107 // Make a copy of the current instruction Row and save it in m_curr_row
108 // so we can add updates as we process the instructions.
109 UnwindPlan::RowSP last_row = unwind_plan.GetLastRow();
110 UnwindPlan::Row *newrow = new UnwindPlan::Row;
111 if (last_row.get())
112 *newrow = *last_row.get();
113 m_curr_row.reset(newrow);
114
115 // Add the initial state to the save list with offset 0.
116 saved_unwind_states.insert({0, {last_row, m_register_values}});
117
118 // cache the pc register number (in whatever register numbering this UnwindPlan uses) for
119 // quick reference during instruction parsing.
120 uint32_t pc_reg_num = LLDB_INVALID_REGNUM;
121 RegisterInfo pc_reg_info;
122 if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info))
123 pc_reg_num = pc_reg_info.kinds[unwind_plan.GetRegisterKind()];
124 else
125 pc_reg_num = LLDB_INVALID_REGNUM;
126
127 // cache the return address register number (in whatever register numbering this UnwindPlan uses) for
128 // quick reference during instruction parsing.
129 uint32_t ra_reg_num = LLDB_INVALID_REGNUM;
130 RegisterInfo ra_reg_info;
131 if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info))
132 ra_reg_num = ra_reg_info.kinds[unwind_plan.GetRegisterKind()];
133 else
134 ra_reg_num = LLDB_INVALID_REGNUM;
135
136 for (size_t idx=0; idx<num_instructions; ++idx)
137 {
138 m_curr_row_modified = false;
139 m_forward_branch_offset = 0;
140
141 inst = inst_list.GetInstructionAtIndex (idx).get();
142 if (inst)
143 {
144 lldb::addr_t current_offset = inst->GetAddress().GetFileAddress() - base_addr;
145 auto it = saved_unwind_states.upper_bound(current_offset);
146 assert(it != saved_unwind_states.begin() && "Unwind row for the function entry missing");
147 --it; // Move it to the row corresponding to the current offset
148
149 // If the offset of m_curr_row don't match with the offset we see in saved_unwind_states
150 // then we have to update m_curr_row and m_register_values based on the saved values. It
151 // is happenning after we processed an epilogue and a return to caller instruction.
152 if (it->second.first->GetOffset() != m_curr_row->GetOffset())
153 {
154 UnwindPlan::Row *newrow = new UnwindPlan::Row;
155 *newrow = *it->second.first;
156 m_curr_row.reset(newrow);
157 m_register_values = it->second.second;;
158 }
159
160 if (log && log->GetVerbose ())
161 {
162 StreamString strm;
163 lldb_private::FormatEntity::Entry format;
164 FormatEntity::Parse("${frame.pc}: ", format);
165 inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, NULL, NULL, NULL, &format, 0);
166 log->PutCString (strm.GetData());
167 }
168
169 m_inst_emulator_ap->SetInstruction (inst->GetOpcode(),
170 inst->GetAddress(),
171 exe_ctx.GetTargetPtr());
172
173 m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions);
174
175 // If the current instruction is a branch forward then save the current CFI information
176 // for the offset where we are branching.
177 if (m_forward_branch_offset != 0 && range.ContainsFileAddress(inst->GetAddress().GetFileAddress() + m_forward_branch_offset))
178 {
179 auto newrow = std::make_shared<UnwindPlan::Row>(*m_curr_row.get());
180 newrow->SetOffset(current_offset + m_forward_branch_offset);
181 saved_unwind_states.insert({current_offset + m_forward_branch_offset, {newrow, m_register_values}});
182 unwind_plan.InsertRow(newrow);
183 }
184
185 // Were there any changes to the CFI while evaluating this instruction?
186 if (m_curr_row_modified)
187 {
188 // Save the modified row if we don't already have a CFI row in the currennt address
189 if (saved_unwind_states.count(current_offset + inst->GetOpcode().GetByteSize()) == 0)
190 {
191 m_curr_row->SetOffset (current_offset + inst->GetOpcode().GetByteSize());
192 unwind_plan.InsertRow (m_curr_row);
193 saved_unwind_states.insert({current_offset + inst->GetOpcode().GetByteSize(), {m_curr_row, m_register_values}});
194
195 // Allocate a new Row for m_curr_row, copy the current state into it
196 UnwindPlan::Row *newrow = new UnwindPlan::Row;
197 *newrow = *m_curr_row.get();
198 m_curr_row.reset(newrow);
199 }
200 }
201 }
202 }
203 }
204 // FIXME: The DisassemblerLLVMC has a reference cycle and won't go away if it has any active instructions.
205 // I'll fix that but for now, just clear the list and it will go away nicely.
206 disasm_sp->GetInstructionList().Clear();
207 }
208
209 if (log && log->GetVerbose ())
210 {
211 StreamString strm;
212 lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(thread.CalculateTarget().get());
213 strm.Printf ("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):", base_addr, base_addr + range.GetByteSize());
214 unwind_plan.Dump(strm, &thread, base_addr);
215 log->PutCString (strm.GetData());
216 }
217 return unwind_plan.GetRowCount() > 0;
218 }
219 return false;
220 }
221
222 bool
AugmentUnwindPlanFromCallSite(AddressRange & func,Thread & thread,UnwindPlan & unwind_plan)223 UnwindAssemblyInstEmulation::AugmentUnwindPlanFromCallSite (AddressRange& func,
224 Thread& thread,
225 UnwindPlan& unwind_plan)
226 {
227 return false;
228 }
229
230 bool
GetFastUnwindPlan(AddressRange & func,Thread & thread,UnwindPlan & unwind_plan)231 UnwindAssemblyInstEmulation::GetFastUnwindPlan (AddressRange& func,
232 Thread& thread,
233 UnwindPlan &unwind_plan)
234 {
235 return false;
236 }
237
238 bool
FirstNonPrologueInsn(AddressRange & func,const ExecutionContext & exe_ctx,Address & first_non_prologue_insn)239 UnwindAssemblyInstEmulation::FirstNonPrologueInsn (AddressRange& func,
240 const ExecutionContext &exe_ctx,
241 Address& first_non_prologue_insn)
242 {
243 return false;
244 }
245
246 UnwindAssembly *
CreateInstance(const ArchSpec & arch)247 UnwindAssemblyInstEmulation::CreateInstance (const ArchSpec &arch)
248 {
249 std::unique_ptr<EmulateInstruction> inst_emulator_ap (EmulateInstruction::FindPlugin (arch, eInstructionTypePrologueEpilogue, NULL));
250 // Make sure that all prologue instructions are handled
251 if (inst_emulator_ap.get())
252 return new UnwindAssemblyInstEmulation (arch, inst_emulator_ap.release());
253 return NULL;
254 }
255
256
257 //------------------------------------------------------------------
258 // PluginInterface protocol in UnwindAssemblyParser_x86
259 //------------------------------------------------------------------
260 ConstString
GetPluginName()261 UnwindAssemblyInstEmulation::GetPluginName()
262 {
263 return GetPluginNameStatic();
264 }
265
266 uint32_t
GetPluginVersion()267 UnwindAssemblyInstEmulation::GetPluginVersion()
268 {
269 return 1;
270 }
271
272 void
Initialize()273 UnwindAssemblyInstEmulation::Initialize()
274 {
275 PluginManager::RegisterPlugin (GetPluginNameStatic(),
276 GetPluginDescriptionStatic(),
277 CreateInstance);
278 }
279
280 void
Terminate()281 UnwindAssemblyInstEmulation::Terminate()
282 {
283 PluginManager::UnregisterPlugin (CreateInstance);
284 }
285
286
287 ConstString
GetPluginNameStatic()288 UnwindAssemblyInstEmulation::GetPluginNameStatic()
289 {
290 static ConstString g_name("inst-emulation");
291 return g_name;
292 }
293
294 const char *
GetPluginDescriptionStatic()295 UnwindAssemblyInstEmulation::GetPluginDescriptionStatic()
296 {
297 return "Instruction emulation based unwind information.";
298 }
299
300
301 uint64_t
MakeRegisterKindValuePair(const RegisterInfo & reg_info)302 UnwindAssemblyInstEmulation::MakeRegisterKindValuePair (const RegisterInfo ®_info)
303 {
304 lldb::RegisterKind reg_kind;
305 uint32_t reg_num;
306 if (EmulateInstruction::GetBestRegisterKindAndNumber (®_info, reg_kind, reg_num))
307 return (uint64_t)reg_kind << 24 | reg_num;
308 return 0ull;
309 }
310
311 void
SetRegisterValue(const RegisterInfo & reg_info,const RegisterValue & reg_value)312 UnwindAssemblyInstEmulation::SetRegisterValue (const RegisterInfo ®_info, const RegisterValue ®_value)
313 {
314 m_register_values[MakeRegisterKindValuePair (reg_info)] = reg_value;
315 }
316
317 bool
GetRegisterValue(const RegisterInfo & reg_info,RegisterValue & reg_value)318 UnwindAssemblyInstEmulation::GetRegisterValue (const RegisterInfo ®_info, RegisterValue ®_value)
319 {
320 const uint64_t reg_id = MakeRegisterKindValuePair (reg_info);
321 RegisterValueMap::const_iterator pos = m_register_values.find(reg_id);
322 if (pos != m_register_values.end())
323 {
324 reg_value = pos->second;
325 return true; // We had a real value that comes from an opcode that wrote
326 // to it...
327 }
328 // We are making up a value that is recognizable...
329 reg_value.SetUInt(reg_id, reg_info.byte_size);
330 return false;
331 }
332
333
334 size_t
ReadMemory(EmulateInstruction * instruction,void * baton,const EmulateInstruction::Context & context,lldb::addr_t addr,void * dst,size_t dst_len)335 UnwindAssemblyInstEmulation::ReadMemory (EmulateInstruction *instruction,
336 void *baton,
337 const EmulateInstruction::Context &context,
338 lldb::addr_t addr,
339 void *dst,
340 size_t dst_len)
341 {
342 Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
343
344 if (log && log->GetVerbose ())
345 {
346 StreamString strm;
347 strm.Printf ("UnwindAssemblyInstEmulation::ReadMemory (addr = 0x%16.16" PRIx64 ", dst = %p, dst_len = %" PRIu64 ", context = ",
348 addr,
349 dst,
350 (uint64_t)dst_len);
351 context.Dump(strm, instruction);
352 log->PutCString (strm.GetData ());
353 }
354 memset (dst, 0, dst_len);
355 return dst_len;
356 }
357
358 size_t
WriteMemory(EmulateInstruction * instruction,void * baton,const EmulateInstruction::Context & context,lldb::addr_t addr,const void * dst,size_t dst_len)359 UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction,
360 void *baton,
361 const EmulateInstruction::Context &context,
362 lldb::addr_t addr,
363 const void *dst,
364 size_t dst_len)
365 {
366 if (baton && dst && dst_len)
367 return ((UnwindAssemblyInstEmulation *)baton)->WriteMemory (instruction, context, addr, dst, dst_len);
368 return 0;
369 }
370
371 size_t
WriteMemory(EmulateInstruction * instruction,const EmulateInstruction::Context & context,lldb::addr_t addr,const void * dst,size_t dst_len)372 UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction,
373 const EmulateInstruction::Context &context,
374 lldb::addr_t addr,
375 const void *dst,
376 size_t dst_len)
377 {
378 DataExtractor data (dst,
379 dst_len,
380 instruction->GetArchitecture ().GetByteOrder(),
381 instruction->GetArchitecture ().GetAddressByteSize());
382
383 Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
384
385 if (log && log->GetVerbose ())
386 {
387 StreamString strm;
388
389 strm.PutCString ("UnwindAssemblyInstEmulation::WriteMemory (");
390 data.Dump(&strm, 0, eFormatBytes, 1, dst_len, UINT32_MAX, addr, 0, 0);
391 strm.PutCString (", context = ");
392 context.Dump(strm, instruction);
393 log->PutCString (strm.GetData());
394 }
395
396 const bool cant_replace = false;
397
398 switch (context.type)
399 {
400 default:
401 case EmulateInstruction::eContextInvalid:
402 case EmulateInstruction::eContextReadOpcode:
403 case EmulateInstruction::eContextImmediate:
404 case EmulateInstruction::eContextAdjustBaseRegister:
405 case EmulateInstruction::eContextRegisterPlusOffset:
406 case EmulateInstruction::eContextAdjustPC:
407 case EmulateInstruction::eContextRegisterStore:
408 case EmulateInstruction::eContextRegisterLoad:
409 case EmulateInstruction::eContextRelativeBranchImmediate:
410 case EmulateInstruction::eContextAbsoluteBranchRegister:
411 case EmulateInstruction::eContextSupervisorCall:
412 case EmulateInstruction::eContextTableBranchReadMemory:
413 case EmulateInstruction::eContextWriteRegisterRandomBits:
414 case EmulateInstruction::eContextWriteMemoryRandomBits:
415 case EmulateInstruction::eContextArithmetic:
416 case EmulateInstruction::eContextAdvancePC:
417 case EmulateInstruction::eContextReturnFromException:
418 case EmulateInstruction::eContextPopRegisterOffStack:
419 case EmulateInstruction::eContextAdjustStackPointer:
420 break;
421
422 case EmulateInstruction::eContextPushRegisterOnStack:
423 {
424 uint32_t reg_num = LLDB_INVALID_REGNUM;
425 uint32_t generic_regnum = LLDB_INVALID_REGNUM;
426 if (context.info_type == EmulateInstruction::eInfoTypeRegisterToRegisterPlusOffset)
427 {
428 const uint32_t unwind_reg_kind = m_unwind_plan_ptr->GetRegisterKind();
429 reg_num = context.info.RegisterToRegisterPlusOffset.data_reg.kinds[unwind_reg_kind];
430 generic_regnum = context.info.RegisterToRegisterPlusOffset.data_reg.kinds[eRegisterKindGeneric];
431 }
432 else
433 assert (!"unhandled case, add code to handle this!");
434
435 if (reg_num != LLDB_INVALID_REGNUM && generic_regnum != LLDB_REGNUM_GENERIC_SP)
436 {
437 if (m_pushed_regs.find (reg_num) == m_pushed_regs.end())
438 {
439 m_pushed_regs[reg_num] = addr;
440 const int32_t offset = addr - m_initial_sp;
441 m_curr_row->SetRegisterLocationToAtCFAPlusOffset (reg_num, offset, cant_replace);
442 m_curr_row_modified = true;
443 }
444 }
445 }
446 break;
447
448 }
449
450 return dst_len;
451 }
452
453 bool
ReadRegister(EmulateInstruction * instruction,void * baton,const RegisterInfo * reg_info,RegisterValue & reg_value)454 UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction,
455 void *baton,
456 const RegisterInfo *reg_info,
457 RegisterValue ®_value)
458 {
459
460 if (baton && reg_info)
461 return ((UnwindAssemblyInstEmulation *)baton)->ReadRegister (instruction, reg_info, reg_value);
462 return false;
463 }
464 bool
ReadRegister(EmulateInstruction * instruction,const RegisterInfo * reg_info,RegisterValue & reg_value)465 UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction,
466 const RegisterInfo *reg_info,
467 RegisterValue ®_value)
468 {
469 bool synthetic = GetRegisterValue (*reg_info, reg_value);
470
471 Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
472
473 if (log && log->GetVerbose ())
474 {
475
476 StreamString strm;
477 strm.Printf ("UnwindAssemblyInstEmulation::ReadRegister (name = \"%s\") => synthetic_value = %i, value = ", reg_info->name, synthetic);
478 reg_value.Dump(&strm, reg_info, false, false, eFormatDefault);
479 log->PutCString(strm.GetData());
480 }
481 return true;
482 }
483
484 bool
WriteRegister(EmulateInstruction * instruction,void * baton,const EmulateInstruction::Context & context,const RegisterInfo * reg_info,const RegisterValue & reg_value)485 UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction,
486 void *baton,
487 const EmulateInstruction::Context &context,
488 const RegisterInfo *reg_info,
489 const RegisterValue ®_value)
490 {
491 if (baton && reg_info)
492 return ((UnwindAssemblyInstEmulation *)baton)->WriteRegister (instruction, context, reg_info, reg_value);
493 return false;
494 }
495 bool
WriteRegister(EmulateInstruction * instruction,const EmulateInstruction::Context & context,const RegisterInfo * reg_info,const RegisterValue & reg_value)496 UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction,
497 const EmulateInstruction::Context &context,
498 const RegisterInfo *reg_info,
499 const RegisterValue ®_value)
500 {
501 Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
502
503 if (log && log->GetVerbose ())
504 {
505
506 StreamString strm;
507 strm.Printf ("UnwindAssemblyInstEmulation::WriteRegister (name = \"%s\", value = ", reg_info->name);
508 reg_value.Dump(&strm, reg_info, false, false, eFormatDefault);
509 strm.PutCString (", context = ");
510 context.Dump(strm, instruction);
511 log->PutCString(strm.GetData());
512 }
513
514 SetRegisterValue (*reg_info, reg_value);
515
516 switch (context.type)
517 {
518 case EmulateInstruction::eContextInvalid:
519 case EmulateInstruction::eContextReadOpcode:
520 case EmulateInstruction::eContextImmediate:
521 case EmulateInstruction::eContextAdjustBaseRegister:
522 case EmulateInstruction::eContextRegisterPlusOffset:
523 case EmulateInstruction::eContextAdjustPC:
524 case EmulateInstruction::eContextRegisterStore:
525 case EmulateInstruction::eContextSupervisorCall:
526 case EmulateInstruction::eContextTableBranchReadMemory:
527 case EmulateInstruction::eContextWriteRegisterRandomBits:
528 case EmulateInstruction::eContextWriteMemoryRandomBits:
529 case EmulateInstruction::eContextArithmetic:
530 case EmulateInstruction::eContextAdvancePC:
531 case EmulateInstruction::eContextReturnFromException:
532 case EmulateInstruction::eContextPushRegisterOnStack:
533 case EmulateInstruction::eContextRegisterLoad:
534 // {
535 // const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
536 // if (reg_num != LLDB_INVALID_REGNUM)
537 // {
538 // const bool can_replace_only_if_unspecified = true;
539 //
540 // m_curr_row.SetRegisterLocationToUndefined (reg_num,
541 // can_replace_only_if_unspecified,
542 // can_replace_only_if_unspecified);
543 // m_curr_row_modified = true;
544 // }
545 // }
546 break;
547
548 case EmulateInstruction::eContextAbsoluteBranchRegister:
549 case EmulateInstruction::eContextRelativeBranchImmediate:
550 {
551 if (context.info_type == EmulateInstruction::eInfoTypeISAAndImmediate &&
552 context.info.ISAAndImmediate.unsigned_data32 > 0)
553 {
554 m_forward_branch_offset = context.info.ISAAndImmediateSigned.signed_data32;
555 }
556 else if (context.info_type == EmulateInstruction::eInfoTypeISAAndImmediateSigned &&
557 context.info.ISAAndImmediateSigned.signed_data32 > 0)
558 {
559 m_forward_branch_offset = context.info.ISAAndImmediate.unsigned_data32;
560 }
561 else if (context.info_type == EmulateInstruction::eInfoTypeImmediate &&
562 context.info.unsigned_immediate > 0)
563 {
564 m_forward_branch_offset = context.info.unsigned_immediate;
565 }
566 else if (context.info_type == EmulateInstruction::eInfoTypeImmediateSigned &&
567 context.info.signed_immediate > 0)
568 {
569 m_forward_branch_offset = context.info.signed_immediate;
570 }
571 }
572 break;
573
574 case EmulateInstruction::eContextPopRegisterOffStack:
575 {
576 const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
577 const uint32_t generic_regnum = reg_info->kinds[eRegisterKindGeneric];
578 if (reg_num != LLDB_INVALID_REGNUM && generic_regnum != LLDB_REGNUM_GENERIC_SP)
579 {
580 m_curr_row->SetRegisterLocationToSame (reg_num, /*must_replace*/ false);
581 m_curr_row_modified = true;
582 }
583 }
584 break;
585
586 case EmulateInstruction::eContextSetFramePointer:
587 if (!m_fp_is_cfa)
588 {
589 m_fp_is_cfa = true;
590 m_cfa_reg_info = *reg_info;
591 const uint32_t cfa_reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
592 assert (cfa_reg_num != LLDB_INVALID_REGNUM);
593 m_curr_row->GetCFAValue().SetIsRegisterPlusOffset(cfa_reg_num, m_initial_sp -
594 reg_value.GetAsUInt64());
595 m_curr_row_modified = true;
596 }
597 break;
598
599 case EmulateInstruction::eContextAdjustStackPointer:
600 // If we have created a frame using the frame pointer, don't follow
601 // subsequent adjustments to the stack pointer.
602 if (!m_fp_is_cfa)
603 {
604 m_curr_row->GetCFAValue().SetIsRegisterPlusOffset(
605 m_curr_row->GetCFAValue().GetRegisterNumber(),
606 m_initial_sp - reg_value.GetAsUInt64());
607 m_curr_row_modified = true;
608 }
609 break;
610 }
611 return true;
612 }
613
614
615