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/Log.h"
19#include "lldb/Core/PluginManager.h"
20#include "lldb/Core/StreamString.h"
21#include "lldb/Target/ExecutionContext.h"
22#include "lldb/Target/Process.h"
23#include "lldb/Target/Thread.h"
24#include "lldb/Target/Target.h"
25
26using namespace lldb;
27using namespace lldb_private;
28
29
30
31//-----------------------------------------------------------------------------------------------
32//  UnwindAssemblyInstEmulation method definitions
33//-----------------------------------------------------------------------------------------------
34
35bool
36UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly (AddressRange& range,
37                                                                   Thread& thread,
38                                                                   UnwindPlan& unwind_plan)
39{
40    if (range.GetByteSize() > 0 &&
41        range.GetBaseAddress().IsValid() &&
42        m_inst_emulator_ap.get())
43    {
44
45        // The the instruction emulation subclass setup the unwind plan for the
46        // first instruction.
47        m_inst_emulator_ap->CreateFunctionEntryUnwind (unwind_plan);
48
49        // CreateFunctionEntryUnwind should have created the first row. If it
50        // doesn't, then we are done.
51        if (unwind_plan.GetRowCount() == 0)
52            return false;
53
54        ExecutionContext exe_ctx;
55        thread.CalculateExecutionContext(exe_ctx);
56        DisassemblerSP disasm_sp (Disassembler::DisassembleRange (m_arch,
57                                                                  NULL,
58                                                                  NULL,
59                                                                  exe_ctx,
60                                                                  range));
61
62        Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
63
64        if (disasm_sp)
65        {
66
67            m_range_ptr = ⦥
68            m_thread_ptr = &thread;
69            m_unwind_plan_ptr = &unwind_plan;
70
71            const uint32_t addr_byte_size = m_arch.GetAddressByteSize();
72            const bool show_address = true;
73            const bool show_bytes = true;
74            m_inst_emulator_ap->GetRegisterInfo (unwind_plan.GetRegisterKind(),
75                                                 unwind_plan.GetInitialCFARegister(),
76                                                 m_cfa_reg_info);
77
78            m_fp_is_cfa = false;
79            m_register_values.clear();
80            m_pushed_regs.clear();
81
82            // Initialize the CFA with a known value. In the 32 bit case
83            // it will be 0x80000000, and in the 64 bit case 0x8000000000000000.
84            // We use the address byte size to be safe for any future addresss sizes
85            m_initial_sp = (1ull << ((addr_byte_size * 8) - 1));
86            RegisterValue cfa_reg_value;
87            cfa_reg_value.SetUInt (m_initial_sp, m_cfa_reg_info.byte_size);
88            SetRegisterValue (m_cfa_reg_info, cfa_reg_value);
89
90            const InstructionList &inst_list = disasm_sp->GetInstructionList ();
91            const size_t num_instructions = inst_list.GetSize();
92
93            if (num_instructions > 0)
94            {
95                Instruction *inst = inst_list.GetInstructionAtIndex (0).get();
96                const addr_t base_addr = inst->GetAddress().GetFileAddress();
97
98                // Make a copy of the current instruction Row and save it in m_curr_row
99                // so we can add updates as we process the instructions.
100                UnwindPlan::RowSP last_row = unwind_plan.GetLastRow();
101                UnwindPlan::Row *newrow = new UnwindPlan::Row;
102                if (last_row.get())
103                    *newrow = *last_row.get();
104                m_curr_row.reset(newrow);
105
106                // Once we've seen the initial prologue instructions complete, save a
107                // copy of the CFI at that point into prologue_completed_row for possible
108                // use later.
109                int instructions_since_last_prologue_insn = 0;     // # of insns since last CFI was update
110
111                bool reinstate_prologue_next_instruction = false;  // Next iteration, re-install the prologue row of CFI
112
113                bool last_instruction_restored_return_addr_reg = false;  // re-install the prologue row of CFI if the next instruction is a branch immediate
114
115                bool return_address_register_has_been_saved = false; // if we've seen the ra register get saved yet
116
117                UnwindPlan::RowSP prologue_completed_row;          // copy of prologue row of CFI
118
119                // cache the pc register number (in whatever register numbering this UnwindPlan uses) for
120                // quick reference during instruction parsing.
121                uint32_t pc_reg_num = LLDB_INVALID_REGNUM;
122                RegisterInfo pc_reg_info;
123                if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info))
124                    pc_reg_num = pc_reg_info.kinds[unwind_plan.GetRegisterKind()];
125                else
126                    pc_reg_num = LLDB_INVALID_REGNUM;
127
128                // cache the return address register number (in whatever register numbering this UnwindPlan uses) for
129                // quick reference during instruction parsing.
130                uint32_t ra_reg_num = LLDB_INVALID_REGNUM;
131                RegisterInfo ra_reg_info;
132                if (m_inst_emulator_ap->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info))
133                    ra_reg_num = ra_reg_info.kinds[unwind_plan.GetRegisterKind()];
134                else
135                    ra_reg_num = LLDB_INVALID_REGNUM;
136
137                for (size_t idx=0; idx<num_instructions; ++idx)
138                {
139                    m_curr_row_modified = false;
140                    m_curr_insn_restored_a_register = false;
141                    inst = inst_list.GetInstructionAtIndex (idx).get();
142                    if (inst)
143                    {
144                        if (log && log->GetVerbose ())
145                        {
146                            StreamString strm;
147                            inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize (), show_address, show_bytes, NULL);
148                            log->PutCString (strm.GetData());
149                        }
150
151                        m_inst_emulator_ap->SetInstruction (inst->GetOpcode(),
152                                                            inst->GetAddress(),
153                                                            exe_ctx.GetTargetPtr());
154
155                        m_inst_emulator_ap->EvaluateInstruction (eEmulateInstructionOptionIgnoreConditions);
156
157                        // Were there any changes to the CFI while evaluating this instruction?
158                        if (m_curr_row_modified)
159                        {
160                            reinstate_prologue_next_instruction = false;
161                            m_curr_row->SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr);
162                            // Append the new row
163                            unwind_plan.AppendRow (m_curr_row);
164
165                            // Allocate a new Row for m_curr_row, copy the current state into it
166                            UnwindPlan::Row *newrow = new UnwindPlan::Row;
167                            *newrow = *m_curr_row.get();
168                            m_curr_row.reset(newrow);
169
170                            // If m_curr_insn_restored_a_register == true, we're looking at an epilogue instruction.
171                            // Set instructions_since_last_prologue_insn to a very high number so we don't append
172                            // any of these epilogue instructions to our prologue_complete row.
173                            if (m_curr_insn_restored_a_register == false && instructions_since_last_prologue_insn < 8)
174                              instructions_since_last_prologue_insn = 0;
175                            else
176                              instructions_since_last_prologue_insn = 99;
177
178                            UnwindPlan::Row::RegisterLocation pc_regloc;
179                            UnwindPlan::Row::RegisterLocation ra_regloc;
180
181                            // While parsing the instructions of this function, if we've ever
182                            // seen the return address register (aka lr on arm) in a non-IsSame() state,
183                            // it has been saved on the stack.  If it's evern back to IsSame(), we've
184                            // executed an epilogue.
185                            if (ra_reg_num != LLDB_INVALID_REGNUM
186                                && m_curr_row->GetRegisterInfo (ra_reg_num, ra_regloc)
187                                && !ra_regloc.IsSame())
188                            {
189                                return_address_register_has_been_saved = true;
190                            }
191
192                            // If the caller's pc is "same", we've just executed an epilogue and we return to the caller
193                            // after this instruction completes executing.
194                            // If there are any instructions past this, there must have been flow control over this
195                            // epilogue so we'll reinstate the original prologue setup instructions.
196                            if (prologue_completed_row.get()
197                                && pc_reg_num != LLDB_INVALID_REGNUM
198                                && m_curr_row->GetRegisterInfo (pc_reg_num, pc_regloc)
199                                && pc_regloc.IsSame())
200                            {
201                                if (log && log->GetVerbose())
202                                    log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- pc is <same>, restore prologue instructions.");
203                                reinstate_prologue_next_instruction = true;
204                            }
205                            else if (prologue_completed_row.get()
206                                     && return_address_register_has_been_saved
207                                     && ra_reg_num != LLDB_INVALID_REGNUM
208                                     && m_curr_row->GetRegisterInfo (ra_reg_num, ra_regloc)
209                                     && ra_regloc.IsSame())
210                            {
211                                if (log && log->GetVerbose())
212                                    log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- lr is <same>, restore prologue instruction if the next instruction is a branch immediate.");
213                                last_instruction_restored_return_addr_reg = true;
214                            }
215                        }
216                        else
217                        {
218                            // If the previous instruction was a return-to-caller (epilogue), and we're still executing
219                            // instructions in this function, there must be a code path that jumps over that epilogue.
220                            // Also detect the case where we epilogue & branch imm to another function (tail-call opt)
221                            // instead of a normal pop lr-into-pc exit.
222                            // Reinstate the frame setup from the prologue.
223                            if (reinstate_prologue_next_instruction
224                                || (m_curr_insn_is_branch_immediate && last_instruction_restored_return_addr_reg))
225                            {
226                                if (log && log->GetVerbose())
227                                    log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- Reinstating prologue instruction set");
228                                UnwindPlan::Row *newrow = new UnwindPlan::Row;
229                                *newrow = *prologue_completed_row.get();
230                                m_curr_row.reset(newrow);
231                                m_curr_row->SetOffset (inst->GetAddress().GetFileAddress() + inst->GetOpcode().GetByteSize() - base_addr);
232                                unwind_plan.AppendRow(m_curr_row);
233
234                                newrow = new UnwindPlan::Row;
235                                *newrow = *m_curr_row.get();
236                                m_curr_row.reset(newrow);
237
238                                reinstate_prologue_next_instruction = false;
239                                last_instruction_restored_return_addr_reg = false;
240                                m_curr_insn_is_branch_immediate = false;
241                            }
242
243                            // clear both of these if either one wasn't set
244                            if (last_instruction_restored_return_addr_reg)
245                            {
246                                last_instruction_restored_return_addr_reg = false;
247                            }
248                            if (m_curr_insn_is_branch_immediate)
249                            {
250                                m_curr_insn_is_branch_immediate = false;
251                            }
252
253                            // Stop updating the prologue instructions if we've seen 8 non-prologue instructions
254                            // in a row.
255                            if (instructions_since_last_prologue_insn++ < 8)
256                            {
257                                UnwindPlan::Row *newrow = new UnwindPlan::Row;
258                                *newrow = *m_curr_row.get();
259                                prologue_completed_row.reset(newrow);
260                                if (log && log->GetVerbose())
261                                    log->Printf("UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly -- saving a copy of the current row as the prologue row.");
262                            }
263                        }
264                    }
265                }
266            }
267            // FIXME: The DisassemblerLLVMC has a reference cycle and won't go away if it has any active instructions.
268            // I'll fix that but for now, just clear the list and it will go away nicely.
269            disasm_sp->GetInstructionList().Clear();
270        }
271
272        if (log && log->GetVerbose ())
273        {
274            StreamString strm;
275            lldb::addr_t base_addr = range.GetBaseAddress().GetLoadAddress(thread.CalculateTarget().get());
276            strm.Printf ("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):", base_addr, base_addr + range.GetByteSize());
277            unwind_plan.Dump(strm, &thread, base_addr);
278            log->PutCString (strm.GetData());
279        }
280        return unwind_plan.GetRowCount() > 0;
281    }
282    return false;
283}
284
285bool
286UnwindAssemblyInstEmulation::GetFastUnwindPlan (AddressRange& func,
287                                                Thread& thread,
288                                                UnwindPlan &unwind_plan)
289{
290    return false;
291}
292
293bool
294UnwindAssemblyInstEmulation::FirstNonPrologueInsn (AddressRange& func,
295                                                   const ExecutionContext &exe_ctx,
296                                                   Address& first_non_prologue_insn)
297{
298    return false;
299}
300
301UnwindAssembly *
302UnwindAssemblyInstEmulation::CreateInstance (const ArchSpec &arch)
303{
304    std::unique_ptr<EmulateInstruction> inst_emulator_ap (EmulateInstruction::FindPlugin (arch, eInstructionTypePrologueEpilogue, NULL));
305    // Make sure that all prologue instructions are handled
306    if (inst_emulator_ap.get())
307        return new UnwindAssemblyInstEmulation (arch, inst_emulator_ap.release());
308    return NULL;
309}
310
311
312//------------------------------------------------------------------
313// PluginInterface protocol in UnwindAssemblyParser_x86
314//------------------------------------------------------------------
315ConstString
316UnwindAssemblyInstEmulation::GetPluginName()
317{
318    return GetPluginNameStatic();
319}
320
321uint32_t
322UnwindAssemblyInstEmulation::GetPluginVersion()
323{
324    return 1;
325}
326
327void
328UnwindAssemblyInstEmulation::Initialize()
329{
330    PluginManager::RegisterPlugin (GetPluginNameStatic(),
331                                   GetPluginDescriptionStatic(),
332                                   CreateInstance);
333}
334
335void
336UnwindAssemblyInstEmulation::Terminate()
337{
338    PluginManager::UnregisterPlugin (CreateInstance);
339}
340
341
342ConstString
343UnwindAssemblyInstEmulation::GetPluginNameStatic()
344{
345    static ConstString g_name("inst-emulation");
346    return g_name;
347}
348
349const char *
350UnwindAssemblyInstEmulation::GetPluginDescriptionStatic()
351{
352    return "Instruction emulation based unwind information.";
353}
354
355
356uint64_t
357UnwindAssemblyInstEmulation::MakeRegisterKindValuePair (const RegisterInfo &reg_info)
358{
359    uint32_t reg_kind, reg_num;
360    if (EmulateInstruction::GetBestRegisterKindAndNumber (&reg_info, reg_kind, reg_num))
361        return (uint64_t)reg_kind << 24 | reg_num;
362    return 0ull;
363}
364
365void
366UnwindAssemblyInstEmulation::SetRegisterValue (const RegisterInfo &reg_info, const RegisterValue &reg_value)
367{
368    m_register_values[MakeRegisterKindValuePair (reg_info)] = reg_value;
369}
370
371bool
372UnwindAssemblyInstEmulation::GetRegisterValue (const RegisterInfo &reg_info, RegisterValue &reg_value)
373{
374    const uint64_t reg_id = MakeRegisterKindValuePair (reg_info);
375    RegisterValueMap::const_iterator pos = m_register_values.find(reg_id);
376    if (pos != m_register_values.end())
377    {
378        reg_value = pos->second;
379        return true; // We had a real value that comes from an opcode that wrote
380                     // to it...
381    }
382    // We are making up a value that is recognizable...
383    reg_value.SetUInt(reg_id, reg_info.byte_size);
384    return false;
385}
386
387
388size_t
389UnwindAssemblyInstEmulation::ReadMemory (EmulateInstruction *instruction,
390                                         void *baton,
391                                         const EmulateInstruction::Context &context,
392                                         lldb::addr_t addr,
393                                         void *dst,
394                                         size_t dst_len)
395{
396    Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
397
398    if (log && log->GetVerbose ())
399    {
400        StreamString strm;
401        strm.Printf ("UnwindAssemblyInstEmulation::ReadMemory    (addr = 0x%16.16" PRIx64 ", dst = %p, dst_len = %" PRIu64 ", context = ",
402                     addr,
403                     dst,
404                     (uint64_t)dst_len);
405        context.Dump(strm, instruction);
406        log->PutCString (strm.GetData ());
407    }
408    memset (dst, 0, dst_len);
409    return dst_len;
410}
411
412size_t
413UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction,
414                                          void *baton,
415                                          const EmulateInstruction::Context &context,
416                                          lldb::addr_t addr,
417                                          const void *dst,
418                                          size_t dst_len)
419{
420    if (baton && dst && dst_len)
421        return ((UnwindAssemblyInstEmulation *)baton)->WriteMemory (instruction, context, addr, dst, dst_len);
422    return 0;
423}
424
425size_t
426UnwindAssemblyInstEmulation::WriteMemory (EmulateInstruction *instruction,
427                                          const EmulateInstruction::Context &context,
428                                          lldb::addr_t addr,
429                                          const void *dst,
430                                          size_t dst_len)
431{
432    DataExtractor data (dst,
433                        dst_len,
434                        instruction->GetArchitecture ().GetByteOrder(),
435                        instruction->GetArchitecture ().GetAddressByteSize());
436
437    Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
438
439    if (log && log->GetVerbose ())
440    {
441        StreamString strm;
442
443        strm.PutCString ("UnwindAssemblyInstEmulation::WriteMemory   (");
444        data.Dump(&strm, 0, eFormatBytes, 1, dst_len, UINT32_MAX, addr, 0, 0);
445        strm.PutCString (", context = ");
446        context.Dump(strm, instruction);
447        log->PutCString (strm.GetData());
448    }
449
450    const bool can_replace = true;
451    const bool cant_replace = false;
452
453    switch (context.type)
454    {
455        default:
456        case EmulateInstruction::eContextInvalid:
457        case EmulateInstruction::eContextReadOpcode:
458        case EmulateInstruction::eContextImmediate:
459        case EmulateInstruction::eContextAdjustBaseRegister:
460        case EmulateInstruction::eContextRegisterPlusOffset:
461        case EmulateInstruction::eContextAdjustPC:
462        case EmulateInstruction::eContextRegisterStore:
463        case EmulateInstruction::eContextRegisterLoad:
464        case EmulateInstruction::eContextRelativeBranchImmediate:
465        case EmulateInstruction::eContextAbsoluteBranchRegister:
466        case EmulateInstruction::eContextSupervisorCall:
467        case EmulateInstruction::eContextTableBranchReadMemory:
468        case EmulateInstruction::eContextWriteRegisterRandomBits:
469        case EmulateInstruction::eContextWriteMemoryRandomBits:
470        case EmulateInstruction::eContextArithmetic:
471        case EmulateInstruction::eContextAdvancePC:
472        case EmulateInstruction::eContextReturnFromException:
473        case EmulateInstruction::eContextPopRegisterOffStack:
474        case EmulateInstruction::eContextAdjustStackPointer:
475            break;
476
477        case EmulateInstruction::eContextPushRegisterOnStack:
478            {
479                uint32_t reg_num = LLDB_INVALID_REGNUM;
480                bool is_return_address_reg = false;
481                const uint32_t unwind_reg_kind = m_unwind_plan_ptr->GetRegisterKind();
482                if (context.info_type == EmulateInstruction::eInfoTypeRegisterToRegisterPlusOffset)
483                {
484                    reg_num = context.info.RegisterToRegisterPlusOffset.data_reg.kinds[unwind_reg_kind];
485                    if (context.info.RegisterToRegisterPlusOffset.data_reg.kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_RA)
486                        is_return_address_reg = true;
487                }
488                else
489                {
490                    assert (!"unhandled case, add code to handle this!");
491                }
492
493                if (reg_num != LLDB_INVALID_REGNUM)
494                {
495                    if (m_pushed_regs.find (reg_num) == m_pushed_regs.end())
496                    {
497                        m_pushed_regs[reg_num] = addr;
498                        const int32_t offset = addr - m_initial_sp;
499                        m_curr_row->SetRegisterLocationToAtCFAPlusOffset (reg_num, offset, cant_replace);
500                        m_curr_row_modified = true;
501                        if (is_return_address_reg)
502                        {
503                            // This push was pushing the return address register,
504                            // so this is also how we will unwind the PC...
505                            RegisterInfo pc_reg_info;
506                            if (instruction->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info))
507                            {
508                                uint32_t pc_reg_num = pc_reg_info.kinds[unwind_reg_kind];
509                                if (pc_reg_num != LLDB_INVALID_REGNUM)
510                                {
511                                    m_curr_row->SetRegisterLocationToAtCFAPlusOffset (pc_reg_num, offset, can_replace);
512                                    m_curr_row_modified = true;
513                                }
514                            }
515                        }
516                    }
517                }
518            }
519            break;
520
521    }
522
523    return dst_len;
524}
525
526bool
527UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction,
528                                           void *baton,
529                                           const RegisterInfo *reg_info,
530                                           RegisterValue &reg_value)
531{
532
533    if (baton && reg_info)
534        return ((UnwindAssemblyInstEmulation *)baton)->ReadRegister (instruction, reg_info, reg_value);
535    return false;
536}
537bool
538UnwindAssemblyInstEmulation::ReadRegister (EmulateInstruction *instruction,
539                                           const RegisterInfo *reg_info,
540                                           RegisterValue &reg_value)
541{
542    bool synthetic = GetRegisterValue (*reg_info, reg_value);
543
544    Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
545
546    if (log && log->GetVerbose ())
547    {
548
549        StreamString strm;
550        strm.Printf ("UnwindAssemblyInstEmulation::ReadRegister  (name = \"%s\") => synthetic_value = %i, value = ", reg_info->name, synthetic);
551        reg_value.Dump(&strm, reg_info, false, false, eFormatDefault);
552        log->PutCString(strm.GetData());
553    }
554    return true;
555}
556
557bool
558UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction,
559                                            void *baton,
560                                            const EmulateInstruction::Context &context,
561                                            const RegisterInfo *reg_info,
562                                            const RegisterValue &reg_value)
563{
564    if (baton && reg_info)
565        return ((UnwindAssemblyInstEmulation *)baton)->WriteRegister (instruction, context, reg_info, reg_value);
566    return false;
567}
568bool
569UnwindAssemblyInstEmulation::WriteRegister (EmulateInstruction *instruction,
570                                            const EmulateInstruction::Context &context,
571                                            const RegisterInfo *reg_info,
572                                            const RegisterValue &reg_value)
573{
574    Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_UNWIND));
575
576    if (log && log->GetVerbose ())
577    {
578
579        StreamString strm;
580        strm.Printf ("UnwindAssemblyInstEmulation::WriteRegister (name = \"%s\", value = ", reg_info->name);
581        reg_value.Dump(&strm, reg_info, false, false, eFormatDefault);
582        strm.PutCString (", context = ");
583        context.Dump(strm, instruction);
584        log->PutCString(strm.GetData());
585    }
586
587    const bool must_replace = true;
588    SetRegisterValue (*reg_info, reg_value);
589
590    switch (context.type)
591    {
592        case EmulateInstruction::eContextInvalid:
593        case EmulateInstruction::eContextReadOpcode:
594        case EmulateInstruction::eContextImmediate:
595        case EmulateInstruction::eContextAdjustBaseRegister:
596        case EmulateInstruction::eContextRegisterPlusOffset:
597        case EmulateInstruction::eContextAdjustPC:
598        case EmulateInstruction::eContextRegisterStore:
599        case EmulateInstruction::eContextRegisterLoad:
600        case EmulateInstruction::eContextAbsoluteBranchRegister:
601        case EmulateInstruction::eContextSupervisorCall:
602        case EmulateInstruction::eContextTableBranchReadMemory:
603        case EmulateInstruction::eContextWriteRegisterRandomBits:
604        case EmulateInstruction::eContextWriteMemoryRandomBits:
605        case EmulateInstruction::eContextArithmetic:
606        case EmulateInstruction::eContextAdvancePC:
607        case EmulateInstruction::eContextReturnFromException:
608        case EmulateInstruction::eContextPushRegisterOnStack:
609//            {
610//                const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
611//                if (reg_num != LLDB_INVALID_REGNUM)
612//                {
613//                    const bool can_replace_only_if_unspecified = true;
614//
615//                    m_curr_row.SetRegisterLocationToUndefined (reg_num,
616//                                                               can_replace_only_if_unspecified,
617//                                                               can_replace_only_if_unspecified);
618//                    m_curr_row_modified = true;
619//                }
620//            }
621            break;
622
623        case EmulateInstruction::eContextRelativeBranchImmediate:
624            {
625
626                {
627                    m_curr_insn_is_branch_immediate = true;
628                }
629            }
630            break;
631
632        case EmulateInstruction::eContextPopRegisterOffStack:
633            {
634                const uint32_t reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
635                if (reg_num != LLDB_INVALID_REGNUM)
636                {
637                    m_curr_row->SetRegisterLocationToSame (reg_num, must_replace);
638                    m_curr_row_modified = true;
639                    m_curr_insn_restored_a_register = true;
640                }
641            }
642            break;
643
644        case EmulateInstruction::eContextSetFramePointer:
645            if (!m_fp_is_cfa)
646            {
647                m_fp_is_cfa = true;
648                m_cfa_reg_info = *reg_info;
649                const uint32_t cfa_reg_num = reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()];
650                assert (cfa_reg_num != LLDB_INVALID_REGNUM);
651                m_curr_row->SetCFARegister(cfa_reg_num);
652                m_curr_row->SetCFAOffset(m_initial_sp - reg_value.GetAsUInt64());
653                m_curr_row_modified = true;
654            }
655            break;
656
657        case EmulateInstruction::eContextAdjustStackPointer:
658            // If we have created a frame using the frame pointer, don't follow
659            // subsequent adjustments to the stack pointer.
660            if (!m_fp_is_cfa)
661            {
662                m_curr_row->SetCFAOffset (m_initial_sp - reg_value.GetAsUInt64());
663                m_curr_row_modified = true;
664            }
665            break;
666    }
667    return true;
668}
669
670
671