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1//===-- ABIWindows_x86_64.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 9#include "ABIWindows_x86_64.h"10 11#include "llvm/ADT/STLExtras.h"12#include "llvm/ADT/StringSwitch.h"13#include "llvm/TargetParser/Triple.h"14 15#include "lldb/Core/Module.h"16#include "lldb/Core/PluginManager.h"17#include "lldb/Core/Value.h"18#include "lldb/Symbol/UnwindPlan.h"19#include "lldb/Target/Process.h"20#include "lldb/Target/RegisterContext.h"21#include "lldb/Target/StackFrame.h"22#include "lldb/Target/Target.h"23#include "lldb/Target/Thread.h"24#include "lldb/Utility/ConstString.h"25#include "lldb/Utility/DataExtractor.h"26#include "lldb/Utility/LLDBLog.h"27#include "lldb/Utility/Log.h"28#include "lldb/Utility/RegisterValue.h"29#include "lldb/Utility/Status.h"30#include "lldb/ValueObject/ValueObjectConstResult.h"31#include "lldb/ValueObject/ValueObjectMemory.h"32#include "lldb/ValueObject/ValueObjectRegister.h"33#include <optional>34 35using namespace lldb;36using namespace lldb_private;37 38LLDB_PLUGIN_DEFINE(ABIWindows_x86_64)39 40enum dwarf_regnums {41  dwarf_rax = 0,42  dwarf_rdx,43  dwarf_rcx,44  dwarf_rbx,45  dwarf_rsi,46  dwarf_rdi,47  dwarf_rbp,48  dwarf_rsp,49  dwarf_r8,50  dwarf_r9,51  dwarf_r10,52  dwarf_r11,53  dwarf_r12,54  dwarf_r13,55  dwarf_r14,56  dwarf_r15,57  dwarf_rip,58  dwarf_xmm0,59  dwarf_xmm1,60  dwarf_xmm2,61  dwarf_xmm3,62  dwarf_xmm4,63  dwarf_xmm5,64  dwarf_xmm6,65  dwarf_xmm7,66  dwarf_xmm8,67  dwarf_xmm9,68  dwarf_xmm10,69  dwarf_xmm11,70  dwarf_xmm12,71  dwarf_xmm13,72  dwarf_xmm14,73  dwarf_xmm15,74  dwarf_stmm0,75  dwarf_stmm1,76  dwarf_stmm2,77  dwarf_stmm3,78  dwarf_stmm4,79  dwarf_stmm5,80  dwarf_stmm6,81  dwarf_stmm7,82  dwarf_ymm0,83  dwarf_ymm1,84  dwarf_ymm2,85  dwarf_ymm3,86  dwarf_ymm4,87  dwarf_ymm5,88  dwarf_ymm6,89  dwarf_ymm7,90  dwarf_ymm8,91  dwarf_ymm9,92  dwarf_ymm10,93  dwarf_ymm11,94  dwarf_ymm12,95  dwarf_ymm13,96  dwarf_ymm14,97  dwarf_ymm15,98  dwarf_bnd0 = 126,99  dwarf_bnd1,100  dwarf_bnd2,101  dwarf_bnd3102};103 104bool ABIWindows_x86_64::GetPointerReturnRegister(const char *&name) {105  name = "rax";106  return true;107}108 109size_t ABIWindows_x86_64::GetRedZoneSize() const { return 0; }110 111//------------------------------------------------------------------112// Static Functions113//------------------------------------------------------------------114 115ABISP116ABIWindows_x86_64::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {117  if (arch.GetTriple().getArch() == llvm::Triple::x86_64 &&118      arch.GetTriple().isOSWindows()) {119    return ABISP(120        new ABIWindows_x86_64(std::move(process_sp), MakeMCRegisterInfo(arch)));121  }122  return ABISP();123}124 125bool ABIWindows_x86_64::PrepareTrivialCall(Thread &thread, addr_t sp,126                                           addr_t func_addr, addr_t return_addr,127                                           llvm::ArrayRef<addr_t> args) const {128  Log *log = GetLog(LLDBLog::Expressions);129 130  if (log) {131    StreamString s;132    s.Printf("ABIWindows_x86_64::PrepareTrivialCall (tid = 0x%" PRIx64133             ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64134             ", return_addr = 0x%" PRIx64,135             thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,136             (uint64_t)return_addr);137 138    for (size_t i = 0; i < args.size(); ++i)139      s.Printf(", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),140               args[i]);141    s.PutCString(")");142    log->PutString(s.GetString());143  }144 145  RegisterContext *reg_ctx = thread.GetRegisterContext().get();146  if (!reg_ctx)147    return false;148 149  const RegisterInfo *reg_info = nullptr;150 151  if (args.size() > 4) // Windows x64 only put first 4 arguments into registers152    return false;153 154  for (size_t i = 0; i < args.size(); ++i) {155    reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,156                                        LLDB_REGNUM_GENERIC_ARG1 + i);157    LLDB_LOGF(log, "About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",158              static_cast<uint64_t>(i + 1), args[i], reg_info->name);159    if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))160      return false;161  }162 163  // First, align the SP164 165  LLDB_LOGF(log, "16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,166            (uint64_t)sp, (uint64_t)(sp & ~0xfull));167 168  sp &= ~(0xfull); // 16-byte alignment169 170  sp -= 8; // return address171 172  Status error;173  const RegisterInfo *pc_reg_info =174      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);175  const RegisterInfo *sp_reg_info =176      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);177  ProcessSP process_sp(thread.GetProcess());178 179  RegisterValue reg_value;180  LLDB_LOGF(log,181            "Pushing the return address onto the stack: 0x%" PRIx64182            ": 0x%" PRIx64,183            (uint64_t)sp, (uint64_t)return_addr);184 185  // Save return address onto the stack186  if (!process_sp->WritePointerToMemory(sp, return_addr, error))187    return false;188 189  // %rsp is set to the actual stack value.190 191  LLDB_LOGF(log, "Writing SP: 0x%" PRIx64, (uint64_t)sp);192 193  if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))194    return false;195 196  // %rip is set to the address of the called function.197 198  LLDB_LOGF(log, "Writing IP: 0x%" PRIx64, (uint64_t)func_addr);199 200  if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))201    return false;202 203  return true;204}205 206static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,207                                bool is_signed, Thread &thread,208                                uint32_t *argument_register_ids,209                                unsigned int &current_argument_register,210                                addr_t &current_stack_argument) {211  if (bit_width > 64)212    return false; // Scalar can't hold large integer arguments213 214  if (current_argument_register < 4) { // Windows pass first 4 arguments to register215    scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(216        argument_register_ids[current_argument_register], 0);217    current_argument_register++;218    if (is_signed)219      scalar.SignExtend(bit_width);220  	return true;221  }222  uint32_t byte_size = (bit_width + (CHAR_BIT - 1)) / CHAR_BIT;223  Status error;224  if (thread.GetProcess()->ReadScalarIntegerFromMemory(225          current_stack_argument, byte_size, is_signed, scalar, error)) {226    current_stack_argument += byte_size;227    return true;228  }229  return false;230}231 232bool ABIWindows_x86_64::GetArgumentValues(Thread &thread,233                                       ValueList &values) const {234  unsigned int num_values = values.GetSize();235  unsigned int value_index;236 237  // Extract the register context so we can read arguments from registers238 239  RegisterContext *reg_ctx = thread.GetRegisterContext().get();240 241  if (!reg_ctx)242    return false;243 244  // Get the pointer to the first stack argument so we have a place to start245  // when reading data246 247  addr_t sp = reg_ctx->GetSP(0);248 249  if (!sp)250    return false;251 252  addr_t current_stack_argument = sp + 8; // jump over return address253 254  uint32_t argument_register_ids[4];255 256  argument_register_ids[0] =257      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)258          ->kinds[eRegisterKindLLDB];259  argument_register_ids[1] =260      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)261          ->kinds[eRegisterKindLLDB];262  argument_register_ids[2] =263      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)264          ->kinds[eRegisterKindLLDB];265  argument_register_ids[3] =266      reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)267          ->kinds[eRegisterKindLLDB];268 269  unsigned int current_argument_register = 0;270 271  for (value_index = 0; value_index < num_values; ++value_index) {272    Value *value = values.GetValueAtIndex(value_index);273 274    if (!value)275      return false;276 277    CompilerType compiler_type = value->GetCompilerType();278    std::optional<uint64_t> bit_size =279        llvm::expectedToOptional(compiler_type.GetBitSize(&thread));280    if (!bit_size)281      return false;282    bool is_signed;283 284    if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {285      ReadIntegerArgument(value->GetScalar(), *bit_size, is_signed, thread,286                          argument_register_ids, current_argument_register,287                          current_stack_argument);288    } else if (compiler_type.IsPointerType()) {289      ReadIntegerArgument(value->GetScalar(), *bit_size, false, thread,290                          argument_register_ids, current_argument_register,291                          current_stack_argument);292    }293  }294 295  return true;296}297 298Status ABIWindows_x86_64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,299                                            lldb::ValueObjectSP &new_value_sp) {300  Status error;301  if (!new_value_sp) {302    error = Status::FromErrorString("Empty value object for return value.");303    return error;304  }305 306  CompilerType compiler_type = new_value_sp->GetCompilerType();307  if (!compiler_type) {308    error = Status::FromErrorString("Null clang type for return value.");309    return error;310  }311 312  Thread *thread = frame_sp->GetThread().get();313 314  bool is_signed;315  bool is_complex;316 317  RegisterContext *reg_ctx = thread->GetRegisterContext().get();318 319  bool set_it_simple = false;320  if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||321      compiler_type.IsPointerType()) {322    const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("rax", 0);323 324    DataExtractor data;325    Status data_error;326    size_t num_bytes = new_value_sp->GetData(data, data_error);327    if (data_error.Fail()) {328      error = Status::FromErrorStringWithFormat(329          "Couldn't convert return value to raw data: %s",330          data_error.AsCString());331      return error;332    }333    lldb::offset_t offset = 0;334    if (num_bytes <= 8) {335      uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);336 337      if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))338        set_it_simple = true;339    } else {340      error = Status::FromErrorString(341          "We don't support returning longer than 64 bit "342          "integer values at present.");343    }344  } else if (compiler_type.IsFloatingPointType(is_complex)) {345    if (is_complex)346      error = Status::FromErrorString(347          "We don't support returning complex values at present");348    else {349      std::optional<uint64_t> bit_width =350          llvm::expectedToOptional(compiler_type.GetBitSize(frame_sp.get()));351      if (!bit_width) {352        error = Status::FromErrorString("can't get type size");353        return error;354      }355      if (*bit_width <= 64) {356        const RegisterInfo *xmm0_info =357            reg_ctx->GetRegisterInfoByName("xmm0", 0);358        RegisterValue xmm0_value;359        DataExtractor data;360        Status data_error;361        size_t num_bytes = new_value_sp->GetData(data, data_error);362        if (data_error.Fail()) {363          error = Status::FromErrorStringWithFormat(364              "Couldn't convert return value to raw data: %s",365              data_error.AsCString());366          return error;367        }368 369        unsigned char buffer[16];370        ByteOrder byte_order = data.GetByteOrder();371 372        data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);373        xmm0_value.SetBytes(buffer, 16, byte_order);374        reg_ctx->WriteRegister(xmm0_info, xmm0_value);375        set_it_simple = true;376      } else {377        // Windows doesn't support 80 bit FP378        error = Status::FromErrorString(379            "Windows-x86_64 doesn't allow FP larger than 64 bits.");380      }381    }382  }383 384  if (!set_it_simple) {385    // Okay we've got a structure or something that doesn't fit in a simple386    // register.387    // TODO(wanyi): On Windows, if the return type is a struct:388    // 1) smaller that 64 bits and return by value -> RAX389    // 2) bigger than 64 bits, the caller will allocate memory for that struct390    // and pass the struct pointer in RCX then return the pointer in RAX391    error = Status::FromErrorString(392        "We only support setting simple integer and float "393        "return types at present.");394  }395 396  return error;397}398 399ValueObjectSP ABIWindows_x86_64::GetReturnValueObjectSimple(400    Thread &thread, CompilerType &return_compiler_type) const {401  ValueObjectSP return_valobj_sp;402  Value value;403 404  if (!return_compiler_type)405    return return_valobj_sp;406 407  value.SetCompilerType(return_compiler_type);408 409  RegisterContext *reg_ctx = thread.GetRegisterContext().get();410  if (!reg_ctx)411    return return_valobj_sp;412 413  const uint32_t type_flags = return_compiler_type.GetTypeInfo();414  if (type_flags & eTypeIsScalar) {415    value.SetValueType(Value::ValueType::Scalar);416 417    bool success = false;418    if (type_flags & eTypeIsInteger) {419      // Extract the register context so we can read arguments from registers420      std::optional<uint64_t> byte_size =421          llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));422      if (!byte_size)423        return return_valobj_sp;424      uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(425          reg_ctx->GetRegisterInfoByName("rax", 0), 0);426      const bool is_signed = (type_flags & eTypeIsSigned) != 0;427      switch (*byte_size) {428      default:429        break;430 431      case sizeof(uint64_t):432        if (is_signed)433          value.GetScalar() = (int64_t)(raw_value);434        else435          value.GetScalar() = (uint64_t)(raw_value);436        success = true;437        break;438 439      case sizeof(uint32_t):440        if (is_signed)441          value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);442        else443          value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);444        success = true;445        break;446 447      case sizeof(uint16_t):448        if (is_signed)449          value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);450        else451          value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);452        success = true;453        break;454 455      case sizeof(uint8_t):456        if (is_signed)457          value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);458        else459          value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);460        success = true;461        break;462      }463    } else if (type_flags & eTypeIsFloat) {464      if (type_flags & eTypeIsComplex) {465        // Don't handle complex yet.466      } else {467        std::optional<uint64_t> byte_size =468            llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));469        if (byte_size && *byte_size <= sizeof(long double)) {470          const RegisterInfo *xmm0_info =471              reg_ctx->GetRegisterInfoByName("xmm0", 0);472          RegisterValue xmm0_value;473          if (reg_ctx->ReadRegister(xmm0_info, xmm0_value)) {474            DataExtractor data;475            if (xmm0_value.GetData(data)) {476              lldb::offset_t offset = 0;477              if (*byte_size == sizeof(float)) {478                value.GetScalar() = (float)data.GetFloat(&offset);479                success = true;480              } else if (*byte_size == sizeof(double)) {481                // double and long double are the same on windows482                value.GetScalar() = (double)data.GetDouble(&offset);483                success = true;484              }485            }486          }487        }488      }489    }490 491    if (success)492      return_valobj_sp = ValueObjectConstResult::Create(493          thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));494  } else if ((type_flags & eTypeIsPointer) ||495             (type_flags & eTypeInstanceIsPointer)) {496    unsigned rax_id =497        reg_ctx->GetRegisterInfoByName("rax", 0)->kinds[eRegisterKindLLDB];498    value.GetScalar() =499        (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(rax_id,500                                                                      0);501    value.SetValueType(Value::ValueType::Scalar);502    return_valobj_sp = ValueObjectConstResult::Create(503        thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));504  } else if (type_flags & eTypeIsVector) {505    std::optional<uint64_t> byte_size =506        llvm::expectedToOptional(return_compiler_type.GetByteSize(&thread));507    if (byte_size && *byte_size > 0) {508      const RegisterInfo *xmm_reg =509          reg_ctx->GetRegisterInfoByName("xmm0", 0);510      if (xmm_reg == nullptr)511        xmm_reg = reg_ctx->GetRegisterInfoByName("mm0", 0);512 513      if (xmm_reg) {514        if (*byte_size <= xmm_reg->byte_size) {515          ProcessSP process_sp(thread.GetProcess());516          if (process_sp) {517            std::unique_ptr<DataBufferHeap> heap_data_up(518                new DataBufferHeap(*byte_size, 0));519            const ByteOrder byte_order = process_sp->GetByteOrder();520            RegisterValue reg_value;521            if (reg_ctx->ReadRegister(xmm_reg, reg_value)) {522              Status error;523              if (reg_value.GetAsMemoryData(*xmm_reg, heap_data_up->GetBytes(),524                                            heap_data_up->GetByteSize(),525                                            byte_order, error)) {526                DataExtractor data(DataBufferSP(heap_data_up.release()),527                                   byte_order,528                                   process_sp->GetTarget()529                                       .GetArchitecture()530                                       .GetAddressByteSize());531                return_valobj_sp = ValueObjectConstResult::Create(532                    &thread, return_compiler_type, ConstString(""), data);533              }534            }535          }536        }537      }538    }539  }540 541  return return_valobj_sp;542}543 544// The compiler will flatten the nested aggregate type into single545// layer and push the value to stack546// This helper function will flatten an aggregate type547// and return true if it can be returned in register(s) by value548// return false if the aggregate is in memory549static bool FlattenAggregateType(550    Thread &thread, ExecutionContext &exe_ctx,551    CompilerType &return_compiler_type,552    uint32_t data_byte_offset,553    std::vector<uint32_t> &aggregate_field_offsets,554    std::vector<CompilerType> &aggregate_compiler_types) {555 556  const uint32_t num_children = return_compiler_type.GetNumFields();557  for (uint32_t idx = 0; idx < num_children; ++idx) {558    std::string name;559    bool is_signed;560    bool is_complex;561 562    uint64_t field_bit_offset = 0;563    CompilerType field_compiler_type = return_compiler_type.GetFieldAtIndex(564        idx, name, &field_bit_offset, nullptr, nullptr);565    std::optional<uint64_t> field_bit_width =566        llvm::expectedToOptional(field_compiler_type.GetBitSize(&thread));567 568    // if we don't know the size of the field (e.g. invalid type), exit569    if (!field_bit_width || *field_bit_width == 0) {570      return false;571    }572    // If there are any unaligned fields, this is stored in memory.573    if (field_bit_offset % *field_bit_width != 0) {574      return false;575    }576 577    // add overall offset578    uint32_t field_byte_offset = field_bit_offset / 8 + data_byte_offset;579 580    const uint32_t field_type_flags = field_compiler_type.GetTypeInfo();581    if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||582        field_compiler_type.IsPointerType() ||583        field_compiler_type.IsFloatingPointType(is_complex)) {584      aggregate_field_offsets.push_back(field_byte_offset);585      aggregate_compiler_types.push_back(field_compiler_type);586    } else if (field_type_flags & eTypeHasChildren) {587      if (!FlattenAggregateType(thread, exe_ctx, field_compiler_type,588                                field_byte_offset, aggregate_field_offsets,589                                aggregate_compiler_types)) {590        return false;591      }592    }593  }594  return true;595}596 597ValueObjectSP ABIWindows_x86_64::GetReturnValueObjectImpl(598    Thread &thread, CompilerType &return_compiler_type) const {599  ValueObjectSP return_valobj_sp;600 601  if (!return_compiler_type) {602    return return_valobj_sp;603  }604 605  // try extract value as if it's a simple type606  return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);607  if (return_valobj_sp) {608    return return_valobj_sp;609  }610 611  RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();612  if (!reg_ctx_sp) {613    return return_valobj_sp;614  }615 616  std::optional<uint64_t> bit_width =617      llvm::expectedToOptional(return_compiler_type.GetBitSize(&thread));618  if (!bit_width) {619    return return_valobj_sp;620  }621 622  // if it's not simple or aggregate type, then we don't know how to handle it623  if (!return_compiler_type.IsAggregateType()) {624    return return_valobj_sp;625  }626 627  ExecutionContext exe_ctx(thread.shared_from_this());628  Target *target = exe_ctx.GetTargetPtr();629  uint32_t max_register_value_bit_width = 64;630 631  // The scenario here is to have a struct/class which is POD632  // if the return struct/class size is larger than 64 bits,633  // the caller will allocate memory for it and pass the return addr in RCX634  // then return the address in RAX635 636  // if the struct is returned by value in register (RAX)637  // its size has to be: 1, 2, 4, 8, 16, 32, or 64 bits (aligned)638  // for floating point, the return value will be copied over to RAX639  bool is_memory = *bit_width > max_register_value_bit_width ||640                   *bit_width & (*bit_width - 1);641  std::vector<uint32_t> aggregate_field_offsets;642  std::vector<CompilerType> aggregate_compiler_types;643  if (!is_memory &&644      FlattenAggregateType(thread, exe_ctx, return_compiler_type,645                           0, aggregate_field_offsets,646                           aggregate_compiler_types)) {647    ByteOrder byte_order = target->GetArchitecture().GetByteOrder();648    WritableDataBufferSP data_sp(649        new DataBufferHeap(max_register_value_bit_width / 8, 0));650    DataExtractor return_ext(data_sp, byte_order,651        target->GetArchitecture().GetAddressByteSize());652 653    // The only register used to return struct/class by value654    const RegisterInfo *rax_info =655        reg_ctx_sp->GetRegisterInfoByName("rax", 0);656    RegisterValue rax_value;657    reg_ctx_sp->ReadRegister(rax_info, rax_value);658    DataExtractor rax_data;659    rax_value.GetData(rax_data);660 661    uint32_t used_bytes =662        0; // Tracks how much of the rax registers we've consumed so far663 664    // in case of the returned type is a subclass of non-abstract-base class665    // it will have a padding to skip the base content666    if (aggregate_field_offsets.size())667      used_bytes = aggregate_field_offsets[0];668 669    const uint32_t num_children = aggregate_compiler_types.size();670    for (uint32_t idx = 0; idx < num_children; idx++) {671      bool is_signed;672      bool is_complex;673 674      CompilerType field_compiler_type = aggregate_compiler_types[idx];675      uint32_t field_byte_width =676          (uint32_t)(llvm::expectedToOptional(677                         field_compiler_type.GetByteSize(&thread))678                         .value_or(0));679      uint32_t field_byte_offset = aggregate_field_offsets[idx];680 681      // this is unlikely w/o the overall size being greater than 8 bytes682      // For now, return a nullptr return value object.683      if (used_bytes >= 8 || used_bytes + field_byte_width > 8) {684        return return_valobj_sp;685      }686 687      DataExtractor *copy_from_extractor = nullptr;688      uint32_t copy_from_offset = 0;689      if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||690          field_compiler_type.IsPointerType() ||691          field_compiler_type.IsFloatingPointType(is_complex)) {692        copy_from_extractor = &rax_data;693        copy_from_offset = used_bytes;694        used_bytes += field_byte_width;695      }696      // These two tests are just sanity checks.  If I somehow get the type697      // calculation wrong above it is better to just return nothing than to698      // assert or crash.699      if (!copy_from_extractor) {700        return return_valobj_sp;701      }702      if (copy_from_offset + field_byte_width >703          copy_from_extractor->GetByteSize()) {704        return return_valobj_sp;705      }706      copy_from_extractor->CopyByteOrderedData(copy_from_offset,707          field_byte_width, data_sp->GetBytes() + field_byte_offset,708          field_byte_width, byte_order);709    }710    if (!is_memory) {711      // The result is in our data buffer.  Let's make a variable object out712      // of it:713      return_valobj_sp = ValueObjectConstResult::Create(714          &thread, return_compiler_type, ConstString(""), return_ext);715    }716  }717 718  // The Windows x86_64 ABI specifies that the return address for MEMORY719  // objects be placed in rax on exit from the function.720 721  // FIXME: This is just taking a guess, rax may very well no longer hold the722  // return storage location.723  // If we are going to do this right, when we make a new frame we should724  // check to see if it uses a memory return, and if we are at the first725  // instruction and if so stash away the return location.  Then we would726  // only return the memory return value if we know it is valid.727  if (is_memory) {728    unsigned rax_id =729        reg_ctx_sp->GetRegisterInfoByName("rax", 0)->kinds[eRegisterKindLLDB];730    lldb::addr_t storage_addr =731        (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(rax_id,732                                                                      0);733    return_valobj_sp = ValueObjectMemory::Create(734        &thread, "", Address(storage_addr, nullptr), return_compiler_type);735  }736  return return_valobj_sp;737}738 739// This defines the CFA as rsp+8740// the saved pc is at CFA-8 (i.e. rsp+0)741// The saved rsp is CFA+0742 743UnwindPlanSP ABIWindows_x86_64::CreateFunctionEntryUnwindPlan() {744  uint32_t sp_reg_num = dwarf_rsp;745  uint32_t pc_reg_num = dwarf_rip;746 747  UnwindPlan::Row row;748  row.GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 8);749  row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, -8, false);750  row.SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);751 752  auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);753  plan_sp->AppendRow(std::move(row));754  plan_sp->SetSourceName("x86_64 at-func-entry default");755  plan_sp->SetSourcedFromCompiler(eLazyBoolNo);756  return plan_sp;757}758 759// Windows-x86_64 doesn't use %rbp760// No available Unwind information for Windows-x86_64 (section .pdata)761// Let's use SysV-x86_64 one for now762UnwindPlanSP ABIWindows_x86_64::CreateDefaultUnwindPlan() {763  uint32_t fp_reg_num = dwarf_rbp;764  uint32_t sp_reg_num = dwarf_rsp;765  uint32_t pc_reg_num = dwarf_rip;766 767  UnwindPlan::Row row;768 769  const int32_t ptr_size = 8;770  row.GetCFAValue().SetIsRegisterPlusOffset(dwarf_rbp, 2 * ptr_size);771  row.SetOffset(0);772  row.SetUnspecifiedRegistersAreUndefined(true);773 774  row.SetRegisterLocationToAtCFAPlusOffset(fp_reg_num, ptr_size * -2, true);775  row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * -1, true);776  row.SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);777 778  auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);779  plan_sp->AppendRow(std::move(row));780  plan_sp->SetSourceName("x86_64 default unwind plan");781  plan_sp->SetSourcedFromCompiler(eLazyBoolNo);782  plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);783  return plan_sp;784}785 786bool ABIWindows_x86_64::RegisterIsVolatile(const RegisterInfo *reg_info) {787  return !RegisterIsCalleeSaved(reg_info);788}789 790bool ABIWindows_x86_64::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {791  if (!reg_info)792    return false;793  assert(reg_info->name != nullptr && "unnamed register?");794  std::string Name = std::string(reg_info->name);795  bool IsCalleeSaved =796      llvm::StringSwitch<bool>(Name)797          .Cases({"rbx", "ebx", "rbp", "ebp", "rdi", "edi", "rsi", "esi"}, true)798          .Cases({"rsp", "esp", "r12", "r13", "r14", "r15", "sp", "fp"}, true)799          .Cases({"xmm6", "xmm7", "xmm8", "xmm9", "xmm10", "xmm11", "xmm12",800                  "xmm13", "xmm14", "xmm15"},801                 true)802          .Default(false);803  return IsCalleeSaved;804}805 806uint32_t ABIWindows_x86_64::GetGenericNum(llvm::StringRef reg) {807  return llvm::StringSwitch<uint32_t>(reg)808      .Case("rip", LLDB_REGNUM_GENERIC_PC)809      .Case("rsp", LLDB_REGNUM_GENERIC_SP)810      .Case("rbp", LLDB_REGNUM_GENERIC_FP)811      .Case("rflags", LLDB_REGNUM_GENERIC_FLAGS)812      // gdbserver uses eflags813      .Case("eflags", LLDB_REGNUM_GENERIC_FLAGS)814      .Case("rcx", LLDB_REGNUM_GENERIC_ARG1)815      .Case("rdx", LLDB_REGNUM_GENERIC_ARG2)816      .Case("r8", LLDB_REGNUM_GENERIC_ARG3)817      .Case("r9", LLDB_REGNUM_GENERIC_ARG4)818      .Default(LLDB_INVALID_REGNUM);819}820 821void ABIWindows_x86_64::Initialize() {822  PluginManager::RegisterPlugin(823      GetPluginNameStatic(), "Windows ABI for x86_64 targets", CreateInstance);824}825 826void ABIWindows_x86_64::Terminate() {827  PluginManager::UnregisterPlugin(CreateInstance);828}829