1 //===-- UnwindAssemblyInstEmulation.cpp --------------------------*- C++-*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "UnwindAssemblyInstEmulation.h" 10 11 #include "lldb/Core/Address.h" 12 #include "lldb/Core/Disassembler.h" 13 #include "lldb/Core/DumpDataExtractor.h" 14 #include "lldb/Core/DumpRegisterValue.h" 15 #include "lldb/Core/FormatEntity.h" 16 #include "lldb/Core/PluginManager.h" 17 #include "lldb/Target/ExecutionContext.h" 18 #include "lldb/Target/Process.h" 19 #include "lldb/Target/Target.h" 20 #include "lldb/Target/Thread.h" 21 #include "lldb/Utility/ArchSpec.h" 22 #include "lldb/Utility/DataBufferHeap.h" 23 #include "lldb/Utility/DataExtractor.h" 24 #include "lldb/Utility/Log.h" 25 #include "lldb/Utility/Status.h" 26 #include "lldb/Utility/StreamString.h" 27 28 using namespace lldb; 29 using namespace lldb_private; 30 31 // UnwindAssemblyInstEmulation method definitions 32 33 bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly( 34 AddressRange &range, Thread &thread, UnwindPlan &unwind_plan) { 35 std::vector<uint8_t> function_text(range.GetByteSize()); 36 ProcessSP process_sp(thread.GetProcess()); 37 if (process_sp) { 38 Status error; 39 const bool prefer_file_cache = true; 40 if (process_sp->GetTarget().ReadMemory( 41 range.GetBaseAddress(), prefer_file_cache, function_text.data(), 42 range.GetByteSize(), error) != range.GetByteSize()) { 43 return false; 44 } 45 } 46 return GetNonCallSiteUnwindPlanFromAssembly( 47 range, function_text.data(), function_text.size(), unwind_plan); 48 } 49 50 bool UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly( 51 AddressRange &range, uint8_t *opcode_data, size_t opcode_size, 52 UnwindPlan &unwind_plan) { 53 if (opcode_data == nullptr || opcode_size == 0) 54 return false; 55 56 if (range.GetByteSize() > 0 && range.GetBaseAddress().IsValid() && 57 m_inst_emulator_up.get()) { 58 59 // The instruction emulation subclass setup the unwind plan for the first 60 // instruction. 61 m_inst_emulator_up->CreateFunctionEntryUnwind(unwind_plan); 62 63 // CreateFunctionEntryUnwind should have created the first row. If it 64 // doesn't, then we are done. 65 if (unwind_plan.GetRowCount() == 0) 66 return false; 67 68 const bool prefer_file_cache = true; 69 DisassemblerSP disasm_sp(Disassembler::DisassembleBytes( 70 m_arch, nullptr, nullptr, range.GetBaseAddress(), opcode_data, 71 opcode_size, 99999, prefer_file_cache)); 72 73 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 74 75 if (disasm_sp) { 76 77 m_range_ptr = ⦥ 78 m_unwind_plan_ptr = &unwind_plan; 79 80 const uint32_t addr_byte_size = m_arch.GetAddressByteSize(); 81 const bool show_address = true; 82 const bool show_bytes = true; 83 m_inst_emulator_up->GetRegisterInfo(unwind_plan.GetRegisterKind(), 84 unwind_plan.GetInitialCFARegister(), 85 m_cfa_reg_info); 86 87 m_fp_is_cfa = false; 88 m_register_values.clear(); 89 m_pushed_regs.clear(); 90 91 // Initialize the CFA with a known value. In the 32 bit case it will be 92 // 0x80000000, and in the 64 bit case 0x8000000000000000. We use the 93 // address byte size to be safe for any future address sizes 94 m_initial_sp = (1ull << ((addr_byte_size * 8) - 1)); 95 RegisterValue cfa_reg_value; 96 cfa_reg_value.SetUInt(m_initial_sp, m_cfa_reg_info.byte_size); 97 SetRegisterValue(m_cfa_reg_info, cfa_reg_value); 98 99 const InstructionList &inst_list = disasm_sp->GetInstructionList(); 100 const size_t num_instructions = inst_list.GetSize(); 101 102 if (num_instructions > 0) { 103 Instruction *inst = inst_list.GetInstructionAtIndex(0).get(); 104 const lldb::addr_t base_addr = inst->GetAddress().GetFileAddress(); 105 106 // Map for storing the unwind plan row and the value of the registers 107 // at a given offset. When we see a forward branch we add a new entry 108 // to this map with the actual unwind plan row and register context for 109 // the target address of the branch as the current data have to be 110 // valid for the target address of the branch too if we are in the same 111 // function. 112 std::map<lldb::addr_t, std::pair<UnwindPlan::RowSP, RegisterValueMap>> 113 saved_unwind_states; 114 115 // Make a copy of the current instruction Row and save it in m_curr_row 116 // so we can add updates as we process the instructions. 117 UnwindPlan::RowSP last_row = unwind_plan.GetLastRow(); 118 UnwindPlan::Row *newrow = new UnwindPlan::Row; 119 if (last_row.get()) 120 *newrow = *last_row.get(); 121 m_curr_row.reset(newrow); 122 123 // Add the initial state to the save list with offset 0. 124 saved_unwind_states.insert({0, {last_row, m_register_values}}); 125 126 // cache the pc register number (in whatever register numbering this 127 // UnwindPlan uses) for quick reference during instruction parsing. 128 RegisterInfo pc_reg_info; 129 m_inst_emulator_up->GetRegisterInfo( 130 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, pc_reg_info); 131 132 // cache the return address register number (in whatever register 133 // numbering this UnwindPlan uses) for quick reference during 134 // instruction parsing. 135 RegisterInfo ra_reg_info; 136 m_inst_emulator_up->GetRegisterInfo( 137 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA, ra_reg_info); 138 139 // The architecture dependent condition code of the last processed 140 // instruction. 141 EmulateInstruction::InstructionCondition last_condition = 142 EmulateInstruction::UnconditionalCondition; 143 lldb::addr_t condition_block_start_offset = 0; 144 145 for (size_t idx = 0; idx < num_instructions; ++idx) { 146 m_curr_row_modified = false; 147 m_forward_branch_offset = 0; 148 149 inst = inst_list.GetInstructionAtIndex(idx).get(); 150 if (inst) { 151 lldb::addr_t current_offset = 152 inst->GetAddress().GetFileAddress() - base_addr; 153 auto it = saved_unwind_states.upper_bound(current_offset); 154 assert(it != saved_unwind_states.begin() && 155 "Unwind row for the function entry missing"); 156 --it; // Move it to the row corresponding to the current offset 157 158 // If the offset of m_curr_row don't match with the offset we see 159 // in saved_unwind_states then we have to update m_curr_row and 160 // m_register_values based on the saved values. It is happening 161 // after we processed an epilogue and a return to caller 162 // instruction. 163 if (it->second.first->GetOffset() != m_curr_row->GetOffset()) { 164 UnwindPlan::Row *newrow = new UnwindPlan::Row; 165 *newrow = *it->second.first; 166 m_curr_row.reset(newrow); 167 m_register_values = it->second.second; 168 } 169 170 m_inst_emulator_up->SetInstruction(inst->GetOpcode(), 171 inst->GetAddress(), nullptr); 172 173 if (last_condition != 174 m_inst_emulator_up->GetInstructionCondition()) { 175 if (m_inst_emulator_up->GetInstructionCondition() != 176 EmulateInstruction::UnconditionalCondition && 177 saved_unwind_states.count(current_offset) == 0) { 178 // If we don't have a saved row for the current offset then 179 // save our current state because we will have to restore it 180 // after the conditional block. 181 auto new_row = 182 std::make_shared<UnwindPlan::Row>(*m_curr_row.get()); 183 saved_unwind_states.insert( 184 {current_offset, {new_row, m_register_values}}); 185 } 186 187 // If the last instruction was conditional with a different 188 // condition then the then current condition then restore the 189 // condition. 190 if (last_condition != 191 EmulateInstruction::UnconditionalCondition) { 192 const auto &saved_state = 193 saved_unwind_states.at(condition_block_start_offset); 194 m_curr_row = 195 std::make_shared<UnwindPlan::Row>(*saved_state.first); 196 m_curr_row->SetOffset(current_offset); 197 m_register_values = saved_state.second; 198 bool replace_existing = 199 true; // The last instruction might already 200 // created a row for this offset and 201 // we want to overwrite it. 202 unwind_plan.InsertRow( 203 std::make_shared<UnwindPlan::Row>(*m_curr_row), 204 replace_existing); 205 } 206 207 // We are starting a new conditional block at the actual offset 208 condition_block_start_offset = current_offset; 209 } 210 211 if (log && log->GetVerbose()) { 212 StreamString strm; 213 lldb_private::FormatEntity::Entry format; 214 FormatEntity::Parse("${frame.pc}: ", format); 215 inst->Dump(&strm, inst_list.GetMaxOpcocdeByteSize(), show_address, 216 show_bytes, nullptr, nullptr, nullptr, &format, 0); 217 log->PutString(strm.GetString()); 218 } 219 220 last_condition = m_inst_emulator_up->GetInstructionCondition(); 221 222 m_inst_emulator_up->EvaluateInstruction( 223 eEmulateInstructionOptionIgnoreConditions); 224 225 // If the current instruction is a branch forward then save the 226 // current CFI information for the offset where we are branching. 227 if (m_forward_branch_offset != 0 && 228 range.ContainsFileAddress(inst->GetAddress().GetFileAddress() + 229 m_forward_branch_offset)) { 230 auto newrow = 231 std::make_shared<UnwindPlan::Row>(*m_curr_row.get()); 232 newrow->SetOffset(current_offset + m_forward_branch_offset); 233 saved_unwind_states.insert( 234 {current_offset + m_forward_branch_offset, 235 {newrow, m_register_values}}); 236 unwind_plan.InsertRow(newrow); 237 } 238 239 // Were there any changes to the CFI while evaluating this 240 // instruction? 241 if (m_curr_row_modified) { 242 // Save the modified row if we don't already have a CFI row in 243 // the current address 244 if (saved_unwind_states.count( 245 current_offset + inst->GetOpcode().GetByteSize()) == 0) { 246 m_curr_row->SetOffset(current_offset + 247 inst->GetOpcode().GetByteSize()); 248 unwind_plan.InsertRow(m_curr_row); 249 saved_unwind_states.insert( 250 {current_offset + inst->GetOpcode().GetByteSize(), 251 {m_curr_row, m_register_values}}); 252 253 // Allocate a new Row for m_curr_row, copy the current state 254 // into it 255 UnwindPlan::Row *newrow = new UnwindPlan::Row; 256 *newrow = *m_curr_row.get(); 257 m_curr_row.reset(newrow); 258 } 259 } 260 } 261 } 262 } 263 } 264 265 if (log && log->GetVerbose()) { 266 StreamString strm; 267 lldb::addr_t base_addr = range.GetBaseAddress().GetFileAddress(); 268 strm.Printf("Resulting unwind rows for [0x%" PRIx64 " - 0x%" PRIx64 "):", 269 base_addr, base_addr + range.GetByteSize()); 270 unwind_plan.Dump(strm, nullptr, base_addr); 271 log->PutString(strm.GetString()); 272 } 273 return unwind_plan.GetRowCount() > 0; 274 } 275 return false; 276 } 277 278 bool UnwindAssemblyInstEmulation::AugmentUnwindPlanFromCallSite( 279 AddressRange &func, Thread &thread, UnwindPlan &unwind_plan) { 280 return false; 281 } 282 283 bool UnwindAssemblyInstEmulation::GetFastUnwindPlan(AddressRange &func, 284 Thread &thread, 285 UnwindPlan &unwind_plan) { 286 return false; 287 } 288 289 bool UnwindAssemblyInstEmulation::FirstNonPrologueInsn( 290 AddressRange &func, const ExecutionContext &exe_ctx, 291 Address &first_non_prologue_insn) { 292 return false; 293 } 294 295 UnwindAssembly * 296 UnwindAssemblyInstEmulation::CreateInstance(const ArchSpec &arch) { 297 std::unique_ptr<EmulateInstruction> inst_emulator_up( 298 EmulateInstruction::FindPlugin(arch, eInstructionTypePrologueEpilogue, 299 nullptr)); 300 // Make sure that all prologue instructions are handled 301 if (inst_emulator_up) 302 return new UnwindAssemblyInstEmulation(arch, inst_emulator_up.release()); 303 return nullptr; 304 } 305 306 // PluginInterface protocol in UnwindAssemblyParser_x86 307 ConstString UnwindAssemblyInstEmulation::GetPluginName() { 308 return GetPluginNameStatic(); 309 } 310 311 uint32_t UnwindAssemblyInstEmulation::GetPluginVersion() { return 1; } 312 313 void UnwindAssemblyInstEmulation::Initialize() { 314 PluginManager::RegisterPlugin(GetPluginNameStatic(), 315 GetPluginDescriptionStatic(), CreateInstance); 316 } 317 318 void UnwindAssemblyInstEmulation::Terminate() { 319 PluginManager::UnregisterPlugin(CreateInstance); 320 } 321 322 ConstString UnwindAssemblyInstEmulation::GetPluginNameStatic() { 323 static ConstString g_name("inst-emulation"); 324 return g_name; 325 } 326 327 const char *UnwindAssemblyInstEmulation::GetPluginDescriptionStatic() { 328 return "Instruction emulation based unwind information."; 329 } 330 331 uint64_t UnwindAssemblyInstEmulation::MakeRegisterKindValuePair( 332 const RegisterInfo ®_info) { 333 lldb::RegisterKind reg_kind; 334 uint32_t reg_num; 335 if (EmulateInstruction::GetBestRegisterKindAndNumber(®_info, reg_kind, 336 reg_num)) 337 return (uint64_t)reg_kind << 24 | reg_num; 338 return 0ull; 339 } 340 341 void UnwindAssemblyInstEmulation::SetRegisterValue( 342 const RegisterInfo ®_info, const RegisterValue ®_value) { 343 m_register_values[MakeRegisterKindValuePair(reg_info)] = reg_value; 344 } 345 346 bool UnwindAssemblyInstEmulation::GetRegisterValue(const RegisterInfo ®_info, 347 RegisterValue ®_value) { 348 const uint64_t reg_id = MakeRegisterKindValuePair(reg_info); 349 RegisterValueMap::const_iterator pos = m_register_values.find(reg_id); 350 if (pos != m_register_values.end()) { 351 reg_value = pos->second; 352 return true; // We had a real value that comes from an opcode that wrote 353 // to it... 354 } 355 // We are making up a value that is recognizable... 356 reg_value.SetUInt(reg_id, reg_info.byte_size); 357 return false; 358 } 359 360 size_t UnwindAssemblyInstEmulation::ReadMemory( 361 EmulateInstruction *instruction, void *baton, 362 const EmulateInstruction::Context &context, lldb::addr_t addr, void *dst, 363 size_t dst_len) { 364 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 365 366 if (log && log->GetVerbose()) { 367 StreamString strm; 368 strm.Printf( 369 "UnwindAssemblyInstEmulation::ReadMemory (addr = 0x%16.16" PRIx64 370 ", dst = %p, dst_len = %" PRIu64 ", context = ", 371 addr, dst, (uint64_t)dst_len); 372 context.Dump(strm, instruction); 373 log->PutString(strm.GetString()); 374 } 375 memset(dst, 0, dst_len); 376 return dst_len; 377 } 378 379 size_t UnwindAssemblyInstEmulation::WriteMemory( 380 EmulateInstruction *instruction, void *baton, 381 const EmulateInstruction::Context &context, lldb::addr_t addr, 382 const void *dst, size_t dst_len) { 383 if (baton && dst && dst_len) 384 return ((UnwindAssemblyInstEmulation *)baton) 385 ->WriteMemory(instruction, context, addr, dst, dst_len); 386 return 0; 387 } 388 389 size_t UnwindAssemblyInstEmulation::WriteMemory( 390 EmulateInstruction *instruction, const EmulateInstruction::Context &context, 391 lldb::addr_t addr, const void *dst, size_t dst_len) { 392 DataExtractor data(dst, dst_len, 393 instruction->GetArchitecture().GetByteOrder(), 394 instruction->GetArchitecture().GetAddressByteSize()); 395 396 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 397 398 if (log && log->GetVerbose()) { 399 StreamString strm; 400 401 strm.PutCString("UnwindAssemblyInstEmulation::WriteMemory ("); 402 DumpDataExtractor(data, &strm, 0, eFormatBytes, 1, dst_len, UINT32_MAX, 403 addr, 0, 0); 404 strm.PutCString(", context = "); 405 context.Dump(strm, instruction); 406 log->PutString(strm.GetString()); 407 } 408 409 const bool cant_replace = false; 410 411 switch (context.type) { 412 default: 413 case EmulateInstruction::eContextInvalid: 414 case EmulateInstruction::eContextReadOpcode: 415 case EmulateInstruction::eContextImmediate: 416 case EmulateInstruction::eContextAdjustBaseRegister: 417 case EmulateInstruction::eContextRegisterPlusOffset: 418 case EmulateInstruction::eContextAdjustPC: 419 case EmulateInstruction::eContextRegisterStore: 420 case EmulateInstruction::eContextRegisterLoad: 421 case EmulateInstruction::eContextRelativeBranchImmediate: 422 case EmulateInstruction::eContextAbsoluteBranchRegister: 423 case EmulateInstruction::eContextSupervisorCall: 424 case EmulateInstruction::eContextTableBranchReadMemory: 425 case EmulateInstruction::eContextWriteRegisterRandomBits: 426 case EmulateInstruction::eContextWriteMemoryRandomBits: 427 case EmulateInstruction::eContextArithmetic: 428 case EmulateInstruction::eContextAdvancePC: 429 case EmulateInstruction::eContextReturnFromException: 430 case EmulateInstruction::eContextPopRegisterOffStack: 431 case EmulateInstruction::eContextAdjustStackPointer: 432 break; 433 434 case EmulateInstruction::eContextPushRegisterOnStack: { 435 uint32_t reg_num = LLDB_INVALID_REGNUM; 436 uint32_t generic_regnum = LLDB_INVALID_REGNUM; 437 assert(context.info_type == 438 EmulateInstruction::eInfoTypeRegisterToRegisterPlusOffset && 439 "unhandled case, add code to handle this!"); 440 const uint32_t unwind_reg_kind = m_unwind_plan_ptr->GetRegisterKind(); 441 reg_num = context.info.RegisterToRegisterPlusOffset.data_reg 442 .kinds[unwind_reg_kind]; 443 generic_regnum = context.info.RegisterToRegisterPlusOffset.data_reg 444 .kinds[eRegisterKindGeneric]; 445 446 if (reg_num != LLDB_INVALID_REGNUM && 447 generic_regnum != LLDB_REGNUM_GENERIC_SP) { 448 if (m_pushed_regs.find(reg_num) == m_pushed_regs.end()) { 449 m_pushed_regs[reg_num] = addr; 450 const int32_t offset = addr - m_initial_sp; 451 m_curr_row->SetRegisterLocationToAtCFAPlusOffset(reg_num, offset, 452 cant_replace); 453 m_curr_row_modified = true; 454 } 455 } 456 } break; 457 } 458 459 return dst_len; 460 } 461 462 bool UnwindAssemblyInstEmulation::ReadRegister(EmulateInstruction *instruction, 463 void *baton, 464 const RegisterInfo *reg_info, 465 RegisterValue ®_value) { 466 467 if (baton && reg_info) 468 return ((UnwindAssemblyInstEmulation *)baton) 469 ->ReadRegister(instruction, reg_info, reg_value); 470 return false; 471 } 472 bool UnwindAssemblyInstEmulation::ReadRegister(EmulateInstruction *instruction, 473 const RegisterInfo *reg_info, 474 RegisterValue ®_value) { 475 bool synthetic = GetRegisterValue(*reg_info, reg_value); 476 477 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 478 479 if (log && log->GetVerbose()) { 480 481 StreamString strm; 482 strm.Printf("UnwindAssemblyInstEmulation::ReadRegister (name = \"%s\") => " 483 "synthetic_value = %i, value = ", 484 reg_info->name, synthetic); 485 DumpRegisterValue(reg_value, &strm, reg_info, false, false, eFormatDefault); 486 log->PutString(strm.GetString()); 487 } 488 return true; 489 } 490 491 bool UnwindAssemblyInstEmulation::WriteRegister( 492 EmulateInstruction *instruction, void *baton, 493 const EmulateInstruction::Context &context, const RegisterInfo *reg_info, 494 const RegisterValue ®_value) { 495 if (baton && reg_info) 496 return ((UnwindAssemblyInstEmulation *)baton) 497 ->WriteRegister(instruction, context, reg_info, reg_value); 498 return false; 499 } 500 bool UnwindAssemblyInstEmulation::WriteRegister( 501 EmulateInstruction *instruction, const EmulateInstruction::Context &context, 502 const RegisterInfo *reg_info, const RegisterValue ®_value) { 503 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND)); 504 505 if (log && log->GetVerbose()) { 506 507 StreamString strm; 508 strm.Printf( 509 "UnwindAssemblyInstEmulation::WriteRegister (name = \"%s\", value = ", 510 reg_info->name); 511 DumpRegisterValue(reg_value, &strm, reg_info, false, false, eFormatDefault); 512 strm.PutCString(", context = "); 513 context.Dump(strm, instruction); 514 log->PutString(strm.GetString()); 515 } 516 517 SetRegisterValue(*reg_info, reg_value); 518 519 switch (context.type) { 520 case EmulateInstruction::eContextInvalid: 521 case EmulateInstruction::eContextReadOpcode: 522 case EmulateInstruction::eContextImmediate: 523 case EmulateInstruction::eContextAdjustBaseRegister: 524 case EmulateInstruction::eContextRegisterPlusOffset: 525 case EmulateInstruction::eContextAdjustPC: 526 case EmulateInstruction::eContextRegisterStore: 527 case EmulateInstruction::eContextSupervisorCall: 528 case EmulateInstruction::eContextTableBranchReadMemory: 529 case EmulateInstruction::eContextWriteRegisterRandomBits: 530 case EmulateInstruction::eContextWriteMemoryRandomBits: 531 case EmulateInstruction::eContextAdvancePC: 532 case EmulateInstruction::eContextReturnFromException: 533 case EmulateInstruction::eContextPushRegisterOnStack: 534 case EmulateInstruction::eContextRegisterLoad: 535 // { 536 // const uint32_t reg_num = 537 // reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 538 // if (reg_num != LLDB_INVALID_REGNUM) 539 // { 540 // const bool can_replace_only_if_unspecified = true; 541 // 542 // m_curr_row.SetRegisterLocationToUndefined (reg_num, 543 // can_replace_only_if_unspecified, 544 // can_replace_only_if_unspecified); 545 // m_curr_row_modified = true; 546 // } 547 // } 548 break; 549 550 case EmulateInstruction::eContextArithmetic: { 551 // If we adjusted the current frame pointer by a constant then adjust the 552 // CFA offset 553 // with the same amount. 554 lldb::RegisterKind kind = m_unwind_plan_ptr->GetRegisterKind(); 555 if (m_fp_is_cfa && reg_info->kinds[kind] == m_cfa_reg_info.kinds[kind] && 556 context.info_type == EmulateInstruction::eInfoTypeRegisterPlusOffset && 557 context.info.RegisterPlusOffset.reg.kinds[kind] == 558 m_cfa_reg_info.kinds[kind]) { 559 const int64_t offset = context.info.RegisterPlusOffset.signed_offset; 560 m_curr_row->GetCFAValue().IncOffset(-1 * offset); 561 m_curr_row_modified = true; 562 } 563 } break; 564 565 case EmulateInstruction::eContextAbsoluteBranchRegister: 566 case EmulateInstruction::eContextRelativeBranchImmediate: { 567 if (context.info_type == EmulateInstruction::eInfoTypeISAAndImmediate && 568 context.info.ISAAndImmediate.unsigned_data32 > 0) { 569 m_forward_branch_offset = 570 context.info.ISAAndImmediateSigned.signed_data32; 571 } else if (context.info_type == 572 EmulateInstruction::eInfoTypeISAAndImmediateSigned && 573 context.info.ISAAndImmediateSigned.signed_data32 > 0) { 574 m_forward_branch_offset = context.info.ISAAndImmediate.unsigned_data32; 575 } else if (context.info_type == EmulateInstruction::eInfoTypeImmediate && 576 context.info.unsigned_immediate > 0) { 577 m_forward_branch_offset = context.info.unsigned_immediate; 578 } else if (context.info_type == 579 EmulateInstruction::eInfoTypeImmediateSigned && 580 context.info.signed_immediate > 0) { 581 m_forward_branch_offset = context.info.signed_immediate; 582 } 583 } break; 584 585 case EmulateInstruction::eContextPopRegisterOffStack: { 586 const uint32_t reg_num = 587 reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 588 const uint32_t generic_regnum = reg_info->kinds[eRegisterKindGeneric]; 589 if (reg_num != LLDB_INVALID_REGNUM && 590 generic_regnum != LLDB_REGNUM_GENERIC_SP) { 591 switch (context.info_type) { 592 case EmulateInstruction::eInfoTypeAddress: 593 if (m_pushed_regs.find(reg_num) != m_pushed_regs.end() && 594 context.info.address == m_pushed_regs[reg_num]) { 595 m_curr_row->SetRegisterLocationToSame(reg_num, 596 false /*must_replace*/); 597 m_curr_row_modified = true; 598 } 599 break; 600 case EmulateInstruction::eInfoTypeISA: 601 assert( 602 (generic_regnum == LLDB_REGNUM_GENERIC_PC || 603 generic_regnum == LLDB_REGNUM_GENERIC_FLAGS) && 604 "eInfoTypeISA used for popping a register other the PC/FLAGS"); 605 if (generic_regnum != LLDB_REGNUM_GENERIC_FLAGS) { 606 m_curr_row->SetRegisterLocationToSame(reg_num, 607 false /*must_replace*/); 608 m_curr_row_modified = true; 609 } 610 break; 611 default: 612 assert(false && "unhandled case, add code to handle this!"); 613 break; 614 } 615 } 616 } break; 617 618 case EmulateInstruction::eContextSetFramePointer: 619 if (!m_fp_is_cfa) { 620 m_fp_is_cfa = true; 621 m_cfa_reg_info = *reg_info; 622 const uint32_t cfa_reg_num = 623 reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 624 assert(cfa_reg_num != LLDB_INVALID_REGNUM); 625 m_curr_row->GetCFAValue().SetIsRegisterPlusOffset( 626 cfa_reg_num, m_initial_sp - reg_value.GetAsUInt64()); 627 m_curr_row_modified = true; 628 } 629 break; 630 631 case EmulateInstruction::eContextRestoreStackPointer: 632 if (m_fp_is_cfa) { 633 m_fp_is_cfa = false; 634 m_cfa_reg_info = *reg_info; 635 const uint32_t cfa_reg_num = 636 reg_info->kinds[m_unwind_plan_ptr->GetRegisterKind()]; 637 assert(cfa_reg_num != LLDB_INVALID_REGNUM); 638 m_curr_row->GetCFAValue().SetIsRegisterPlusOffset( 639 cfa_reg_num, m_initial_sp - reg_value.GetAsUInt64()); 640 m_curr_row_modified = true; 641 } 642 break; 643 644 case EmulateInstruction::eContextAdjustStackPointer: 645 // If we have created a frame using the frame pointer, don't follow 646 // subsequent adjustments to the stack pointer. 647 if (!m_fp_is_cfa) { 648 m_curr_row->GetCFAValue().SetIsRegisterPlusOffset( 649 m_curr_row->GetCFAValue().GetRegisterNumber(), 650 m_initial_sp - reg_value.GetAsUInt64()); 651 m_curr_row_modified = true; 652 } 653 break; 654 } 655 return true; 656 } 657