720 lines · cpp
1//===-- ABISysV_i386.cpp --------------------------------------------------===//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-exception6//===----------------------------------------------------------------------===//7 8#include "ABISysV_i386.h"9 10#include "llvm/ADT/STLExtras.h"11#include "llvm/TargetParser/Triple.h"12 13#include "lldb/Core/Module.h"14#include "lldb/Core/PluginManager.h"15#include "lldb/Core/Value.h"16#include "lldb/Symbol/UnwindPlan.h"17#include "lldb/Target/Process.h"18#include "lldb/Target/RegisterContext.h"19#include "lldb/Target/StackFrame.h"20#include "lldb/Target/Target.h"21#include "lldb/Target/Thread.h"22#include "lldb/Utility/ConstString.h"23#include "lldb/Utility/DataExtractor.h"24#include "lldb/Utility/Log.h"25#include "lldb/Utility/RegisterValue.h"26#include "lldb/Utility/Status.h"27#include "lldb/ValueObject/ValueObjectConstResult.h"28#include "lldb/ValueObject/ValueObjectMemory.h"29#include "lldb/ValueObject/ValueObjectRegister.h"30#include <optional>31 32using namespace lldb;33using namespace lldb_private;34 35LLDB_PLUGIN_DEFINE(ABISysV_i386)36 37// This source file uses the following document as a reference:38//====================================================================39// System V Application Binary Interface40// Intel386 Architecture Processor Supplement, Version 1.041// Edited by42// H.J. Lu, David L Kreitzer, Milind Girkar, Zia Ansari43//44// (Based on45// System V Application Binary Interface,46// AMD64 Architecture Processor Supplement,47// Edited by48// H.J. Lu, Michael Matz, Milind Girkar, Jan Hubicka,49// Andreas Jaeger, Mark Mitchell)50//51// February 3, 201552//====================================================================53 54// DWARF Register Number Mapping55// See Table 2.14 of the reference document (specified on top of this file)56// Comment: Table 2.14 is followed till 'mm' entries. After that, all entries57// are ignored here.58 59enum dwarf_regnums {60 dwarf_eax = 0,61 dwarf_ecx,62 dwarf_edx,63 dwarf_ebx,64 dwarf_esp,65 dwarf_ebp,66 dwarf_esi,67 dwarf_edi,68 dwarf_eip,69};70 71// Static Functions72 73ABISP74ABISysV_i386::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {75 if (arch.GetTriple().getVendor() != llvm::Triple::Apple) {76 if (arch.GetTriple().getArch() == llvm::Triple::x86) {77 return ABISP(78 new ABISysV_i386(std::move(process_sp), MakeMCRegisterInfo(arch)));79 }80 }81 return ABISP();82}83 84bool ABISysV_i386::PrepareTrivialCall(Thread &thread, addr_t sp,85 addr_t func_addr, addr_t return_addr,86 llvm::ArrayRef<addr_t> args) const {87 RegisterContext *reg_ctx = thread.GetRegisterContext().get();88 89 if (!reg_ctx)90 return false;91 92 uint32_t pc_reg_num = reg_ctx->ConvertRegisterKindToRegisterNumber(93 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);94 uint32_t sp_reg_num = reg_ctx->ConvertRegisterKindToRegisterNumber(95 eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);96 97 // While using register info to write a register value to memory, the98 // register info just needs to have the correct size of a 32 bit register,99 // the actual register it pertains to is not important, just the size needs100 // to be correct. "eax" is used here for this purpose.101 const RegisterInfo *reg_info_32 = reg_ctx->GetRegisterInfoByName("eax");102 if (!reg_info_32)103 return false; // TODO this should actually never happen104 105 Status error;106 RegisterValue reg_value;107 108 // Make room for the argument(s) on the stack109 sp -= 4 * args.size();110 111 // SP Alignment112 sp &= ~(16ull - 1ull); // 16-byte alignment113 114 // Write arguments onto the stack115 addr_t arg_pos = sp;116 for (addr_t arg : args) {117 reg_value.SetUInt32(arg);118 error = reg_ctx->WriteRegisterValueToMemory(119 reg_info_32, arg_pos, reg_info_32->byte_size, reg_value);120 if (error.Fail())121 return false;122 arg_pos += 4;123 }124 125 // The return address is pushed onto the stack126 sp -= 4;127 reg_value.SetUInt32(return_addr);128 error = reg_ctx->WriteRegisterValueToMemory(129 reg_info_32, sp, reg_info_32->byte_size, reg_value);130 if (error.Fail())131 return false;132 133 // Setting %esp to the actual stack value.134 if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_num, sp))135 return false;136 137 // Setting %eip to the address of the called function.138 if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_num, func_addr))139 return false;140 141 return true;142}143 144static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,145 bool is_signed, Process *process,146 addr_t ¤t_stack_argument) {147 uint32_t byte_size = (bit_width + (8 - 1)) / 8;148 Status error;149 150 if (!process)151 return false;152 153 if (process->ReadScalarIntegerFromMemory(current_stack_argument, byte_size,154 is_signed, scalar, error)) {155 current_stack_argument += byte_size;156 return true;157 }158 return false;159}160 161bool ABISysV_i386::GetArgumentValues(Thread &thread, ValueList &values) const {162 unsigned int num_values = values.GetSize();163 unsigned int value_index;164 165 RegisterContext *reg_ctx = thread.GetRegisterContext().get();166 167 if (!reg_ctx)168 return false;169 170 // Get pointer to the first stack argument171 addr_t sp = reg_ctx->GetSP(0);172 if (!sp)173 return false;174 175 addr_t current_stack_argument = sp + 4; // jump over return address176 177 for (value_index = 0; value_index < num_values; ++value_index) {178 Value *value = values.GetValueAtIndex(value_index);179 180 if (!value)181 return false;182 183 // Currently: Support for extracting values with Clang QualTypes only.184 CompilerType compiler_type(value->GetCompilerType());185 std::optional<uint64_t> bit_size =186 llvm::expectedToOptional(compiler_type.GetBitSize(&thread));187 if (bit_size) {188 bool is_signed;189 if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {190 ReadIntegerArgument(value->GetScalar(), *bit_size, is_signed,191 thread.GetProcess().get(), current_stack_argument);192 } else if (compiler_type.IsPointerType()) {193 ReadIntegerArgument(value->GetScalar(), *bit_size, false,194 thread.GetProcess().get(), current_stack_argument);195 }196 }197 }198 return true;199}200 201Status ABISysV_i386::SetReturnValueObject(lldb::StackFrameSP &frame_sp,202 lldb::ValueObjectSP &new_value_sp) {203 Status error;204 if (!new_value_sp) {205 error = Status::FromErrorString("Empty value object for return value.");206 return error;207 }208 209 CompilerType compiler_type = new_value_sp->GetCompilerType();210 if (!compiler_type) {211 error = Status::FromErrorString("Null clang type for return value.");212 return error;213 }214 215 const uint32_t type_flags = compiler_type.GetTypeInfo();216 Thread *thread = frame_sp->GetThread().get();217 RegisterContext *reg_ctx = thread->GetRegisterContext().get();218 DataExtractor data;219 Status data_error;220 size_t num_bytes = new_value_sp->GetData(data, data_error);221 bool register_write_successful = true;222 223 if (data_error.Fail()) {224 error = Status::FromErrorStringWithFormat(225 "Couldn't convert return value to raw data: %s",226 data_error.AsCString());227 return error;228 }229 230 // Following "IF ELSE" block categorizes various 'Fundamental Data Types'.231 // The terminology 'Fundamental Data Types' used here is adopted from Table232 // 2.1 of the reference document (specified on top of this file)233 234 if (type_flags & eTypeIsPointer) // 'Pointer'235 {236 if (num_bytes != sizeof(uint32_t)) {237 error =238 Status::FromErrorString("Pointer to be returned is not 4 bytes wide");239 return error;240 }241 lldb::offset_t offset = 0;242 const RegisterInfo *eax_info = reg_ctx->GetRegisterInfoByName("eax", 0);243 uint32_t raw_value = data.GetMaxU32(&offset, num_bytes);244 register_write_successful =245 reg_ctx->WriteRegisterFromUnsigned(eax_info, raw_value);246 } else if ((type_flags & eTypeIsScalar) ||247 (type_flags & eTypeIsEnumeration)) //'Integral' + 'Floating Point'248 {249 lldb::offset_t offset = 0;250 const RegisterInfo *eax_info = reg_ctx->GetRegisterInfoByName("eax", 0);251 252 if (type_flags & eTypeIsInteger) // 'Integral' except enum253 {254 switch (num_bytes) {255 default:256 break;257 case 16:258 // For clang::BuiltinType::UInt128 & Int128 ToDo: Need to decide how to259 // handle it260 break;261 case 8: {262 uint32_t raw_value_low = data.GetMaxU32(&offset, 4);263 const RegisterInfo *edx_info = reg_ctx->GetRegisterInfoByName("edx", 0);264 uint32_t raw_value_high = data.GetMaxU32(&offset, num_bytes - offset);265 register_write_successful =266 (reg_ctx->WriteRegisterFromUnsigned(eax_info, raw_value_low) &&267 reg_ctx->WriteRegisterFromUnsigned(edx_info, raw_value_high));268 break;269 }270 case 4:271 case 2:272 case 1: {273 uint32_t raw_value = data.GetMaxU32(&offset, num_bytes);274 register_write_successful =275 reg_ctx->WriteRegisterFromUnsigned(eax_info, raw_value);276 break;277 }278 }279 } else if (type_flags & eTypeIsEnumeration) // handles enum280 {281 uint32_t raw_value = data.GetMaxU32(&offset, num_bytes);282 register_write_successful =283 reg_ctx->WriteRegisterFromUnsigned(eax_info, raw_value);284 } else if (type_flags & eTypeIsFloat) // 'Floating Point'285 {286 RegisterValue st0_value, fstat_value, ftag_value;287 const RegisterInfo *st0_info = reg_ctx->GetRegisterInfoByName("st0", 0);288 const RegisterInfo *fstat_info =289 reg_ctx->GetRegisterInfoByName("fstat", 0);290 const RegisterInfo *ftag_info = reg_ctx->GetRegisterInfoByName("ftag", 0);291 292 /* According to Page 3-12 of document293 System V Application Binary Interface, Intel386 Architecture Processor294 Supplement, Fourth Edition295 To return Floating Point values, all st% registers except st0 should be296 empty after exiting from297 a function. This requires setting fstat and ftag registers to specific298 values.299 fstat: The TOP field of fstat should be set to a value [0,7]. ABI doesn't300 specify the specific301 value of TOP in case of function return. Hence, we set the TOP field to 7302 by our choice. */303 uint32_t value_fstat_u32 = 0x00003800;304 305 /* ftag: Implication of setting TOP to 7 and indicating all st% registers306 empty except st0 is to set307 7th bit of 4th byte of FXSAVE area to 1 and all other bits of this byte to308 0. This is in accordance309 with the document Intel 64 and IA-32 Architectures Software Developer's310 Manual, January 2015 */311 uint32_t value_ftag_u32 = 0x00000080;312 313 if (num_bytes <= 12) // handles float, double, long double, __float80314 {315 long double value_long_dbl = 0.0;316 if (num_bytes == 4)317 value_long_dbl = data.GetFloat(&offset);318 else if (num_bytes == 8)319 value_long_dbl = data.GetDouble(&offset);320 else if (num_bytes == 12)321 value_long_dbl = data.GetLongDouble(&offset);322 else {323 error = Status::FromErrorString(324 "Invalid number of bytes for this return type");325 return error;326 }327 st0_value.SetLongDouble(value_long_dbl);328 fstat_value.SetUInt32(value_fstat_u32);329 ftag_value.SetUInt32(value_ftag_u32);330 register_write_successful =331 reg_ctx->WriteRegister(st0_info, st0_value) &&332 reg_ctx->WriteRegister(fstat_info, fstat_value) &&333 reg_ctx->WriteRegister(ftag_info, ftag_value);334 } else if (num_bytes == 16) // handles __float128335 {336 error = Status::FromErrorString(337 "Implementation is missing for this clang type.");338 }339 } else {340 // Neither 'Integral' nor 'Floating Point'. If flow reaches here then341 // check type_flags. This type_flags is not a valid type.342 error = Status::FromErrorString("Invalid clang type");343 }344 } else {345 /* 'Complex Floating Point', 'Packed', 'Decimal Floating Point' and346 'Aggregate' data types347 are yet to be implemented */348 error = Status::FromErrorString(349 "Currently only Integral and Floating Point clang "350 "types are supported.");351 }352 if (!register_write_successful)353 error = Status::FromErrorString("Register writing failed");354 return error;355}356 357ValueObjectSP ABISysV_i386::GetReturnValueObjectSimple(358 Thread &thread, CompilerType &return_compiler_type) const {359 ValueObjectSP return_valobj_sp;360 Value value;361 362 if (!return_compiler_type)363 return return_valobj_sp;364 365 value.SetCompilerType(return_compiler_type);366 367 RegisterContext *reg_ctx = thread.GetRegisterContext().get();368 if (!reg_ctx)369 return return_valobj_sp;370 371 const uint32_t type_flags = return_compiler_type.GetTypeInfo();372 373 unsigned eax_id =374 reg_ctx->GetRegisterInfoByName("eax", 0)->kinds[eRegisterKindLLDB];375 unsigned edx_id =376 reg_ctx->GetRegisterInfoByName("edx", 0)->kinds[eRegisterKindLLDB];377 378 // Following "IF ELSE" block categorizes various 'Fundamental Data Types'.379 // The terminology 'Fundamental Data Types' used here is adopted from Table380 // 2.1 of the reference document (specified on top of this file)381 382 if (type_flags & eTypeIsPointer) // 'Pointer'383 {384 uint32_t ptr =385 thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) &386 0xffffffff;387 value.SetValueType(Value::ValueType::Scalar);388 value.GetScalar() = ptr;389 return_valobj_sp = ValueObjectConstResult::Create(390 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));391 } else if ((type_flags & eTypeIsScalar) ||392 (type_flags & eTypeIsEnumeration)) //'Integral' + 'Floating Point'393 {394 value.SetValueType(Value::ValueType::Scalar);395 std::optional<uint64_t> byte_size =396 llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));397 if (!byte_size)398 return return_valobj_sp;399 bool success = false;400 401 if (type_flags & eTypeIsInteger) // 'Integral' except enum402 {403 const bool is_signed = ((type_flags & eTypeIsSigned) != 0);404 uint64_t raw_value =405 thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) &406 0xffffffff;407 raw_value |=408 (thread.GetRegisterContext()->ReadRegisterAsUnsigned(edx_id, 0) &409 0xffffffff)410 << 32;411 412 switch (*byte_size) {413 default:414 break;415 416 case 16:417 // For clang::BuiltinType::UInt128 & Int128 ToDo: Need to decide how to418 // handle it419 break;420 421 case 8:422 if (is_signed)423 value.GetScalar() = (int64_t)(raw_value);424 else425 value.GetScalar() = (uint64_t)(raw_value);426 success = true;427 break;428 429 case 4:430 if (is_signed)431 value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);432 else433 value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);434 success = true;435 break;436 437 case 2:438 if (is_signed)439 value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);440 else441 value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);442 success = true;443 break;444 445 case 1:446 if (is_signed)447 value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);448 else449 value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);450 success = true;451 break;452 }453 454 if (success)455 return_valobj_sp = ValueObjectConstResult::Create(456 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));457 } else if (type_flags & eTypeIsEnumeration) // handles enum458 {459 uint32_t enm =460 thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) &461 0xffffffff;462 value.SetValueType(Value::ValueType::Scalar);463 value.GetScalar() = enm;464 return_valobj_sp = ValueObjectConstResult::Create(465 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));466 } else if (type_flags & eTypeIsFloat) // 'Floating Point'467 {468 if (*byte_size <= 12) // handles float, double, long double, __float80469 {470 const RegisterInfo *st0_info = reg_ctx->GetRegisterInfoByName("st0", 0);471 RegisterValue st0_value;472 473 if (reg_ctx->ReadRegister(st0_info, st0_value)) {474 DataExtractor data;475 if (st0_value.GetData(data)) {476 lldb::offset_t offset = 0;477 long double value_long_double = data.GetLongDouble(&offset);478 479 // float is 4 bytes.480 if (*byte_size == 4) {481 float value_float = (float)value_long_double;482 value.GetScalar() = value_float;483 success = true;484 } else if (*byte_size == 8) {485 // double is 8 bytes486 // On Android Platform: long double is also 8 bytes It will be487 // handled here only.488 double value_double = (double)value_long_double;489 value.GetScalar() = value_double;490 success = true;491 } else if (*byte_size == 12) {492 // long double and __float80 are 12 bytes on i386.493 value.GetScalar() = value_long_double;494 success = true;495 }496 }497 }498 499 if (success)500 return_valobj_sp = ValueObjectConstResult::Create(501 thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));502 } else if (*byte_size == 16) // handles __float128503 {504 lldb::addr_t storage_addr = (uint32_t)(505 thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) &506 0xffffffff);507 return_valobj_sp = ValueObjectMemory::Create(508 &thread, "", Address(storage_addr, nullptr), return_compiler_type);509 }510 } else // Neither 'Integral' nor 'Floating Point'511 {512 // If flow reaches here then check type_flags This type_flags is513 // unhandled514 }515 } else if (type_flags & eTypeIsComplex) // 'Complex Floating Point'516 {517 // ToDo: Yet to be implemented518 } else if (type_flags & eTypeIsVector) // 'Packed'519 {520 std::optional<uint64_t> byte_size =521 llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));522 if (byte_size && *byte_size > 0) {523 const RegisterInfo *vec_reg = reg_ctx->GetRegisterInfoByName("xmm0", 0);524 if (vec_reg == nullptr)525 vec_reg = reg_ctx->GetRegisterInfoByName("mm0", 0);526 527 if (vec_reg) {528 if (*byte_size <= vec_reg->byte_size) {529 ProcessSP process_sp(thread.GetProcess());530 if (process_sp) {531 std::unique_ptr<DataBufferHeap> heap_data_up(532 new DataBufferHeap(*byte_size, 0));533 const ByteOrder byte_order = process_sp->GetByteOrder();534 RegisterValue reg_value;535 if (reg_ctx->ReadRegister(vec_reg, reg_value)) {536 Status error;537 if (reg_value.GetAsMemoryData(*vec_reg, heap_data_up->GetBytes(),538 heap_data_up->GetByteSize(),539 byte_order, error)) {540 DataExtractor data(DataBufferSP(heap_data_up.release()),541 byte_order,542 process_sp->GetTarget()543 .GetArchitecture()544 .GetAddressByteSize());545 return_valobj_sp = ValueObjectConstResult::Create(546 &thread, return_compiler_type, ConstString(""), data);547 }548 }549 }550 } else if (*byte_size <= vec_reg->byte_size * 2) {551 const RegisterInfo *vec_reg2 =552 reg_ctx->GetRegisterInfoByName("xmm1", 0);553 if (vec_reg2) {554 ProcessSP process_sp(thread.GetProcess());555 if (process_sp) {556 std::unique_ptr<DataBufferHeap> heap_data_up(557 new DataBufferHeap(*byte_size, 0));558 const ByteOrder byte_order = process_sp->GetByteOrder();559 RegisterValue reg_value;560 RegisterValue reg_value2;561 if (reg_ctx->ReadRegister(vec_reg, reg_value) &&562 reg_ctx->ReadRegister(vec_reg2, reg_value2)) {563 564 Status error;565 if (reg_value.GetAsMemoryData(566 *vec_reg, heap_data_up->GetBytes(), vec_reg->byte_size,567 byte_order, error) &&568 reg_value2.GetAsMemoryData(569 *vec_reg2,570 heap_data_up->GetBytes() + vec_reg->byte_size,571 heap_data_up->GetByteSize() - vec_reg->byte_size,572 byte_order, error)) {573 DataExtractor data(DataBufferSP(heap_data_up.release()),574 byte_order,575 process_sp->GetTarget()576 .GetArchitecture()577 .GetAddressByteSize());578 return_valobj_sp = ValueObjectConstResult::Create(579 &thread, return_compiler_type, ConstString(""), data);580 }581 }582 }583 }584 }585 }586 }587 } else // 'Decimal Floating Point'588 {589 // ToDo: Yet to be implemented590 }591 return return_valobj_sp;592}593 594ValueObjectSP ABISysV_i386::GetReturnValueObjectImpl(595 Thread &thread, CompilerType &return_compiler_type) const {596 ValueObjectSP return_valobj_sp;597 598 if (!return_compiler_type)599 return return_valobj_sp;600 601 ExecutionContext exe_ctx(thread.shared_from_this());602 return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);603 if (return_valobj_sp)604 return return_valobj_sp;605 606 RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();607 if (!reg_ctx_sp)608 return return_valobj_sp;609 610 if (return_compiler_type.IsAggregateType()) {611 unsigned eax_id =612 reg_ctx_sp->GetRegisterInfoByName("eax", 0)->kinds[eRegisterKindLLDB];613 lldb::addr_t storage_addr = (uint32_t)(614 thread.GetRegisterContext()->ReadRegisterAsUnsigned(eax_id, 0) &615 0xffffffff);616 return_valobj_sp = ValueObjectMemory::Create(617 &thread, "", Address(storage_addr, nullptr), return_compiler_type);618 }619 620 return return_valobj_sp;621}622 623// This defines CFA as esp+4624// The saved pc is at CFA-4 (i.e. esp+0)625// The saved esp is CFA+0626 627UnwindPlanSP ABISysV_i386::CreateFunctionEntryUnwindPlan() {628 uint32_t sp_reg_num = dwarf_esp;629 uint32_t pc_reg_num = dwarf_eip;630 631 UnwindPlan::Row row;632 row.GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 4);633 row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, -4, false);634 row.SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);635 636 auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);637 plan_sp->AppendRow(std::move(row));638 plan_sp->SetSourceName("i386 at-func-entry default");639 plan_sp->SetSourcedFromCompiler(eLazyBoolNo);640 return plan_sp;641}642 643// This defines CFA as ebp+8644// The saved pc is at CFA-4 (i.e. ebp+4)645// The saved ebp is at CFA-8 (i.e. ebp+0)646// The saved esp is CFA+0647 648UnwindPlanSP ABISysV_i386::CreateDefaultUnwindPlan() {649 uint32_t fp_reg_num = dwarf_ebp;650 uint32_t sp_reg_num = dwarf_esp;651 uint32_t pc_reg_num = dwarf_eip;652 653 UnwindPlan::Row row;654 const int32_t ptr_size = 4;655 656 row.GetCFAValue().SetIsRegisterPlusOffset(fp_reg_num, 2 * ptr_size);657 row.SetUnspecifiedRegistersAreUndefined(true);658 659 row.SetRegisterLocationToAtCFAPlusOffset(fp_reg_num, ptr_size * -2, true);660 row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * -1, true);661 row.SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);662 663 auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);664 plan_sp->AppendRow(std::move(row));665 plan_sp->SetSourceName("i386 default unwind plan");666 plan_sp->SetSourcedFromCompiler(eLazyBoolNo);667 plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);668 plan_sp->SetUnwindPlanForSignalTrap(eLazyBoolNo);669 return plan_sp;670}671 672// According to "Register Usage" in reference document (specified on top of673// this source file) ebx, ebp, esi, edi and esp registers are preserved i.e.674// non-volatile i.e. callee-saved on i386675bool ABISysV_i386::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {676 if (!reg_info)677 return false;678 679 // Saved registers are ebx, ebp, esi, edi, esp, eip680 const char *name = reg_info->name;681 if (name[0] == 'e') {682 switch (name[1]) {683 case 'b':684 if (name[2] == 'x' || name[2] == 'p')685 return name[3] == '\0';686 break;687 case 'd':688 if (name[2] == 'i')689 return name[3] == '\0';690 break;691 case 'i':692 if (name[2] == 'p')693 return name[3] == '\0';694 break;695 case 's':696 if (name[2] == 'i' || name[2] == 'p')697 return name[3] == '\0';698 break;699 }700 }701 702 if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp703 return true;704 if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp705 return true;706 if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc707 return true;708 709 return false;710}711 712void ABISysV_i386::Initialize() {713 PluginManager::RegisterPlugin(714 GetPluginNameStatic(), "System V ABI for i386 targets", CreateInstance);715}716 717void ABISysV_i386::Terminate() {718 PluginManager::UnregisterPlugin(CreateInstance);719}720